WorldWideScience

Sample records for hydrocarbon oxidation progress

  1. 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...

  2. Atmospheric oxidation of selected hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Benter, T.; Olariu, R.I.

    2002-02-01

    This work presents investigations on the gas-phase chemistry of phenol and the cresol isomers performed in a 1080 l quartz glass reactor in Wuppertal and in a large-volume outdoor photoreactor EUPHORE in Valencia, Spain. The studies aimed at clarifying the oxidation mechanisms of the reactions of these compounds with OH and NO{sub 3} radicals. Product investigations on the oxidation of phenol and the cresol isomers initiated by OH radicals were performed in the 1080 l quartz glass reactor with analyses by in situ FT-IR absorption spectroscopy. The primary focus of the investigations was on the determination of product yields. This work represents the first determination and quantification of 1,2-dihydroxybenzenes in the OH oxidation of phenolic compounds. Possible reaction pathways leading to the observed products have been elucidated. (orig.)

  3. 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

  4. Oxidation of gaseous hydrocarbons by alkene-utilizing bacteria

    NARCIS (Netherlands)

    Ginkel, van C.G.

    1987-01-01

    Gaseous alkenes are widespread in the environment due to the emission of these hydrocarbons by industry and due to their production from natural sources as for instance ethene by plants, fungi and bacteria. Micro-organisms have developed the potential to oxidize these hydrocarbons. Alkenes

  5. Oxidation of gaseous hydrocarbons by alkene-utilizing bacteria.

    NARCIS (Netherlands)

    Ginkel, van C.G.

    1987-01-01

    Gaseous alkenes are widespread in the environment due to the emission of these hydrocarbons by industry and due to their production from natural sources as for instance ethene by plants, fungi and bacteria. Micro-organisms have developed the potential to oxidize these hydrocarbons. Alkenes can eithe

  6. A PROCESS FOR THE CATALYTIC OXIDATION OF HYDROCARBONS

    DEFF Research Database (Denmark)

    1999-01-01

    A process for producing an alcohol from a gaseous hydrocarbon, e.g. a lower alkane such as methane, via oxidative reaction of the hydrocarbon in a concentrated sulfuric acid medium in the presence of a catalyst employs an added catalyst comprising a substance selected from iodine, iodine compounds...

  7. Selective aerobic oxidation of hydrocarbons over supported gold catalysts

    NARCIS (Netherlands)

    Hereijgers, B.P.C.

    2011-01-01

    The selective oxidation of hydrocarbons is of vital importance for the production of valuable chemicals from crude oil and natural gas resources. Unfortunately, when using molecular oxygen as an environmentally benign oxidant, these processes face tremendous difficulties, most importantly in control

  8. Conversion of hydrocarbons in solid oxide fuel cells

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Kammer Hansen, K.

    2003-01-01

    Recently, a number of papers about direct oxidation of methane and hydrocarbon in solid oxide fuel cells (SOFC) at relatively low temperatures (about 700degreesC) have been published. Even though the conversion of almost dry CH4 at 1000degreesC on ceramic anodes was demonstrated more than 10 years...

  9. Chemical – thermodynamics description of oxidization of hydrocarbon fuels

    Directory of Open Access Journals (Sweden)

    О.Л. Матвєєва

    2005-01-01

    Full Text Available  In theory it is grounded, that in the process of exploitation because of intensification of oxidizing processes worsening takes place of power properties of fuels, in particular warmth of combustion, due to reduction of thermal effects of reactions of combustion of the oxidized hydrocarbons.

  10. OXIDATION OF DRY HYDROCARBONS AT HIGH-POWER DENSITY ANODES

    Energy Technology Data Exchange (ETDEWEB)

    K.Krist; O. Spaldon-Stewart; R. Remick

    2004-03-01

    This work builds upon discoveries by the University of Pennsylvania and others pertaining to the oxidation of dry hydrocarbon fuels in high temperature solid oxide fuel cells. The work reported here was restricted primarily to dry methane and confirms that YSZ-based cells, having ceria in the anode as a catalyst and copper in the anode as a current collector, can operate on dry methane for extended periods. Thirty-three lab-scale cells of various designs were fabricated and operated under a variety of conditions. The longest-lived cell gave stable performance on dry methane at 800 C for over 305 hours. Only slight carbon deposition was noted at the completion of the test. A corresponding nickel/YSZ-based anode would have lasted for less than an hour under these test conditions (which included open circuit potential measurements) before carbon fouling essentially destroyed the cell. The best performing cell achieved 112 mW/cm{sub 2} on dry methane at 800 C. Several problems were encountered with carbon fouling and declining open circuit voltages in many of the test cells after switching from operation on hydrogen to dry methane. Although not rigorously confirmed by experimentation, the results suggested that air infiltration through less than perfect perimeter seals or pinholes in the electrolytes, or both gave rise to conditions that caused the carbon fouling and OCV decline. Small amounts of air reacting with methane in a partial oxidation reaction could produce carbon monoxide that, in turn, would deposit the carbon. If this mechanism is confirmed, it implies that near perfect hardware is required for extended operation. Some evidence was also found for the formation of electrical shorts, probably from carbon deposits bridging the electrolyte. Work with odorized methane and with methane containing 100-ppm hydrogen sulfide confirmed that copper is stable at 800 C in dry hydrocarbon fuels in the presence of sulfur. In a number of cases, but not exclusively, the

  11. Bio-inspired Iron Catalysts for Hydrocarbon Oxidations

    Energy Technology Data Exchange (ETDEWEB)

    Que, Jr., Lawrence [Univ. of Minnesota, Minneapolis, MN (United States)

    2016-03-22

    Stereoselective oxidation of C–H and C=C bonds are catalyzed by nonheme iron enzymes. Inspired by these bioinorganic systems, our group has been exploring the use of nonheme iron complexes as catalysts for the oxidation of hydrocarbons using H2O2 as an environmentally friendly and atom-efficient oxidant in order to gain mechanistic insights into these novel transformations. In particular, we have focused on clarifying the nature of the high-valent iron oxidants likely to be involved in these transformations.

  12. Initiation Chemistries in Hydrocarbon (Aut)Oxidation.

    Science.gov (United States)

    Sandhiya, Lakshmanan; Zipse, Hendrik

    2015-09-28

    For the (aut)oxidation of toluene to benzyl hydroperoxide, benzyl alcohol, benzaldehyde, and benzoic acid, the thermochemical profiles for various radical-generating reactions have been compared. A key intermediate in all of these reactions is benzyl hydroperoxide, the heat of formation of which has been estimated by using results from CBS-QB3, G4, and G3B3 calculations. Homolytic O-O bond cleavage in this hydroperoxide is strongly endothermic and thus unlikely to contribute significantly to initiation processes. In terms of reaction enthalpies the most favorable initiation process involves bimolecular reaction of benzyl hydroperoxide to yield hydroxy and benzyloxy radicals along with water and benzaldehyde. The reaction enthalpy and free energy of this process is significantly more favorable than those for the unimolecular dissociation of known radical initiators, such as dibenzoylperoxide or dibenzylhyponitrite.

  13. 非热等离子体烃类燃料氧化重整反应器的研究进展%Progress of non-thermal plasma reactors for oxidative reforming of hydrocarbon fuel

    Institute of Scientific and Technical Information of China (English)

    丁天英; 刘景林; 赵天亮; 朱爱民

    2015-01-01

    Oxidative reforming (partial oxidation) of fuel is mildly exothermic and has the advantages of fast reaction and low energy cost, which is especially suitable for on-line production of H2 or H2-rich gas. Atmospheric-pressure non-thermal plasma provides a very promising new technology for oxidative reforming of fuel with significant advantages of feed flexibility, fast response, and compact, efficient reactor. The recent developments of atmospheric pressure non-thermal plasma reactors for oxidative reforming of hydrocarbon fuel are reviewed. The warm plasma generated by spark and gliding arc discharges and its fuel reforming reactors are presented. Compared with the reactors of cold plasma generated by corona and dielectric barrier discharges, the warm plasma reactor exhibits high fuel conversion as well as low energy cost.%燃料氧化重整(部分氧化)为温和的放热反应,其反应速率快、能耗低,特别适用于在线制取氢气或富氢气体。大气压非热等离子体为燃料氧化重整提供了一种应用前景广泛的新技术,展现了对燃料具有普适性、快速响应和反应器紧凑高效等优点。综述了大气压非热等离子体烃类燃料氧化重整反应器的研究进展,着重阐述了火花和滑动弧放电产生的暖等离子体及其烃类燃料重整反应器。与电晕和介质阻挡放电产生的冷等离子体反应器相比,暖等离子体反应器具有燃料转化率高和能耗低的优点。

  14. Novel, benign, solid catalysts for the oxidation of hydrocarbons.

    Science.gov (United States)

    Ratnasamy, Paul; Raja, Robert; Srinivas, Darbha

    2005-04-15

    The catalytic properties of two classes of solid catalysts for the oxidation of hydrocarbons in the liquid phase are discussed: (i) microporous solids, encapsulating transition metal complexes in their cavities and (ii) titanosilicate molecular sieves. Copper acetate dimers encapsulated in molecular sieves Y, MCM-22 and VPI-5 use dioxygen to regioselectively ortho-hydroxylate L-tyrosine to L-dopa, phenol to catechol and cresols to the corresponding o-dihydroxy and o-quinone compounds. Monomeric copper phthalocyanine and salen complexes entrapped in zeolite-Y oxidize methane to methanol, toluene to cresols, naphthalene to naphthols, xylene to xylenols and phenol to diphenols. Trimeric mu3-oxo-bridged Co/Mn cluster complexes, encapsulated inside Y-zeolite, oxidize para-xylene, almost quantitatively, to terephthalic acid. In almost all cases, the intrinsic catalytic activity (turnover frequency) of the metal complex is enhanced very significantly, upon encapsulation in the porous solids. Spectroscopic and electrochemical studies suggest that the geometric distortions of the complex on encapsulation change the electron density at the metal ion site and its redox behaviour, thereby influencing its catalytic activity and selectivity in oxidation reactions. Titanosilicate molecular sieves can oxidize hydrocarbons using dioxygen when loaded with transition metals like Pd, Au or Ag. The structure of surface Ti ions and the type of oxo-Ti species generated on contact with oxidants depend on several factors including the method of zeolite synthesis, zeolite structure, solvent, temperature and oxidant. Although, similar oxo-Ti species are present on all the titanosilicates, their relative concentrations vary among different structures and determine the product selectivity.

  15. 40 CFR 52.269 - Control strategy and regulations: Photochemical oxidants (hydrocarbons) and carbon monoxide.

    Science.gov (United States)

    2010-07-01

    ...: Photochemical oxidants (hydrocarbons) and carbon monoxide. 52.269 Section 52.269 Protection of Environment... PLANS California § 52.269 Control strategy and regulations: Photochemical oxidants (hydrocarbons) and... provide for attainment and maintenance of the national standards for photochemical oxidants...

  16. Humate effect on oil-oxidizing activity of hydrocarbon-oxidizing microorganisms

    Directory of Open Access Journals (Sweden)

    Faizulina Elmira

    2015-10-01

    Full Text Available The effect of humic substances on the activity of hydrocarbon-oxidizing microorganisms is studied. It is shown that sodium humate, aminogumic and sulfogumic acids did not have a negative impact on the growth of oiloxidizing microorganisms. Introduction of sodium humate in the culture medium stimulated the destructive activity of oil-oxidizing microorganisms. At its addition the degree of oil degradation was 72.5-84.5%, and atits absence – 70.7-78.3%.

  17. Identification of persulfate oxidation products of polycyclic aromatic hydrocarbon during remediation of contaminated soil

    Science.gov (United States)

    The extent of PAH transformation, the formation and transformation of reaction byproducts during persulfate oxidation of polycyclic aromatic hydrocarbons (PAHs) in coking plant soil was investigated. Pre-oxidation analyses indicated that oxygen-containing PAHs (oxy-PAHs) existed ...

  18. Identification of persulfate oxidation products of polycyclic aromatic hydrocarbon during remediation of contaminated soil

    Science.gov (United States)

    The extent of PAH transformation, the formation and transformation of reaction byproducts during persulfate oxidation of polycyclic aromatic hydrocarbons (PAHs) in coking plant soil was investigated. Pre-oxidation analyses indicated that oxygen-containing PAHs (oxy-PAHs) existed ...

  19. 40 CFR 52.229 - Control strategy and regulations: Photochemical oxidants (hydrocarbons), Metropolitan Los Angeles...

    Science.gov (United States)

    2010-07-01

    ...: Photochemical oxidants (hydrocarbons), Metropolitan Los Angeles Intrastate Region. 52.229 Section 52.229... oxidants (hydrocarbons), Metropolitan Los Angeles Intrastate Region. (a) (b) The following rules are... and approved for the SIP, remain federally enforceable: (1) Los Angeles County APCD, Regulation IV...

  20. Theoretical studies of hydrocarbon combustion chemistry. Annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, H.F. III

    1994-08-01

    The author reports here the results of DZP CISD calculations for methylcarbene. Geometry, symmetry, and vibrational modes for the radical are reported for both the singlet and the triplet state. Future work will focus on the ethyl radical-oxygen interaction relevant to hydrocarbon combustion.

  1. Zeolites Modified Metal Cations as Catalysts in Hydrocarbon Oxidation and the Alkyl Alcohol

    OpenAIRE

    Agadadsh Makhmud Aliyev; Zumrud Abdulmutallib Shabanova; Fikret Vakhid Aliyev; Alla M. Guseynova

    2014-01-01

    The results of studies on the creation of highly metalltceolitnyh systems and the study of their catalytic activities in the oxidation of lower olefin hydrocarbons (ethylene to acetaldehyde, acetone, propylene, butylene methyl ethyl ketone); aliphatic C1-C5 alcohols to their corresponding aldehydes, ketones, carboxylic acids and carboxylic acid esters; oxidative dehydrogenation of naphthenes in the alicyclic diene hydrocarbons and the oxidative dimerization of methane to acetylene. It has bee...

  2. Development of direct hydrocarbon solid oxide fuel cells

    Science.gov (United States)

    McIntosh, Steven

    The focus of this dissertation is the development of a Solid Oxide Fuel Cell (SOFC) that can operate with hydrocarbon fuels without the need for pre-reforming. The design of an active SOFC anode requires the consideration of a number of factors including the catalytic activity of the electrode towards fuel oxidation and electronic conductivity. This work focuses on a novel system for anode fabrication that allows the catalytically active and electronically conducting components of the anode to be easily varied. The catalytic properties of the SOFC anode were examined and a strong link between SOFC performance and oxidation activity demonstrated. Of the rare-earth catalysts investigated ceria was found to have the highest activity leading to the highest fuel cell power density. This activity was further improved, especially for methane fuel, by doping with a precious metal. Furthermore, it was shown that the catalyst not only increased the rate of reaction but increased the cell Open-Circuit Voltage (OCV) suggesting a change in mechanism that increased the cell efficiency. The necessity for high electronic conductivity and connectivity in the electrode was elucidated by studying the impact of anode copper content on cell performance. Low copper loading led to reduced cell performance due to a lack of conductive pathways from the active electrode region to the external circuit. It was observed that additional conductivity was provided by a thermally deposited carbonaceous phase formed upon exposure to hydrocarbon fuels. The electrochemical characterization of SOFC electrodes is a non-trivial problem. Literature reports on the properties of similar electrodes are inconsistent and often contradictory. Using a combined experimental and theoretical approach, significant problems were found with common experimental procedures used to separate the losses associated the cell cathode from those of the anode. By calculating the effect of test geometry on this separation, it

  3. Facile Synthesis of Highly Active and Robust Ni-Mo Bimetallic Electrocatalyst for Hydrocarbon Oxidation in Solid Oxide Fuel Cells

    NARCIS (Netherlands)

    Hua, B.; Li, M.; Zhang, Y.-Q.; Chen, J.; Sun, Y.-F.; Yan, N.; Li, J.; Luo, J.L.

    2016-01-01

    We report a novel Ni–Mo bimetallic alloy decorated with multimicrocrystals as an efficient anode catalyst for hydrocarbon-fueled solid oxide fuel cells (SOFCs). We show that these Ni–Mo bimetallic alloys are highly active, thermally stable, and sulfur/coke tolerant electrocatalysts for hydrocarbon o

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

    Science.gov (United States)

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

    2012-10-02

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

  5. Partially oxidized polycyclic aromatic hydrocarbons show an increased bioavailability and biodegradability.

    NARCIS (Netherlands)

    Meulenberg, R.; Rijnaarts, H.H.M.; Doddema, H.J.; Field, J.A.

    1997-01-01

    Polycyclic aromatic hydrocarbons have a low water solubility and tend to adsorb on soil particles, which both result in slow bioremediation processes. Many microorganisms, known for their ability to degrade polycyclic aromatic hydrocarbons, only partially oxidize these compounds. White rot fungi, fo

  6. Low-density hydrocarbon foams for laser fusion targets: Progress report, 1987

    Energy Technology Data Exchange (ETDEWEB)

    Haendler, B.L.; Buckley, S.R.; Chen, C.; Cook, A.R.; Cook, R.C.; Hair, L.M.; Kong, F.M.; Kramer, H.D.; Letts, S.A.; Overturf, G.E. III

    1988-06-01

    This report describes progress made in the development of direct-drive hydrocarbon foam targets for laser inertial confinement fusion during 1987. The foam materials are polystyrene, resorcinol-formaldehyde, carbonized resorcinol-formaldehyde, and cellulose acetate. The processes for making the foams, their properties, characterization techniques, and the relationship of their properties to target specifications are presented. Progress in the creation and testing of prototype targets is also described.

  7. Treatment of hydrocarbon contamination under flow through conditions by using magnetite catalyzed chemical oxidation.

    Science.gov (United States)

    Usman, M; Faure, P; Lorgeoux, C; Ruby, C; Hanna, K

    2013-01-01

    Soil pollution by hydrocarbons (aromatic and aliphatic hydrocarbons) is a major environmental issue. Various treatments have been used to remove them from contaminated soils. In our previous studies, the ability of magnetite has been successfully explored to catalyze chemical oxidation for hydrocarbon remediation in batch slurry system. In the present laboratory study, column experiments were performed to evaluate the efficiency of magnetite catalyzed Fenton-like (FL) and activated persulfate (AP) oxidation for hydrocarbon degradation. Flow-through column experiments are intended to provide a better representation of field conditions. Organic extracts isolated from three different soils (an oil-contaminated soil from petrochemical industrial site and two soils polluted by polycyclic aromatic hydrocarbon (PAH) originating from coking plant sites) were spiked on sand. After solvent evaporation, spiked sand was packed in column and was subjected to oxidation using magnetite as catalyst. Oxidant solution was injected at a flow rate of 0.1 mL min(-1) under water-saturated conditions. Organic analyses were performed by GC-mass spectrometry, GC-flame ionization detector, and micro-Fourier transform infrared spectroscopy. Significant abatement of both types of hydrocarbons (60-70 %) was achieved after chemical oxidation (FL and AP) of organic extracts. No significant by-products were formed during oxidation experiment, underscoring the complete degradation of hydrocarbons. No selective degradation was observed for FL with almost similar efficiency towards all hydrocarbons. However, AP showed less reactivity towards higher molecular weight PAHs and aromatic oxygenated compounds. Results of this study demonstrated that magnetite-catalyzed chemical oxidation can effectively degrade both aromatic and aliphatic hydrocarbons (enhanced available contaminants) under flow-through conditions.

  8. Oxidative coulometric trace determination of sulphur in hydrocarbons.

    Science.gov (United States)

    Cedergren, A

    1973-07-01

    A new combustion system for the oxidative coulometric determination of sulphur in liquid hydrocarbons is described. The conditions were selected so that the recovery as SO(2) was close to 100%. The relative standard deviation was < 1% for sulphur in the range 2-1000 mg/l., with thiophene in cyclohexane as a test substance. Thermodynamic data on the equilibrium between SO(2), O(2) and SO(3) were used to select the operating conditions. To increase the recovery of SO(2) the combustion gas mixture was diluted with an inert gas to lower the partial pressure of oxygen. A temperature of 1000 degrees in the equilibrium zone resulted in a recovery of 99%. The SO(2) was titrated with coulometrically generated iodine, the concentration of which was controlled by a Pt-redox electrode. The response of this electrode has been examined. A rather high concentration of I(-) was used to suppress iodine losses during the analysis. The time of analysis was 2-5 min, and sample sizes were 3-7 mul. An LKB 16300 Coulometric Analyzer governed the titration procedure.

  9. GREEN CATALYZED OXIDATION OF HYDROCARBONS IN ALTERNATIVE SOLVENT SYSTEMS GENERATED BY PARIS II

    Science.gov (United States)

    Green Catalyzed Oxidation of Hydrocarbons in Alternative Solvent Systems Generated by PARIS IIMichael A. Gonzalez*, Thomas M. Becker, and Paul F. Harten; Sustainable Technology Division, Office of Research and Development; United States Environmental Protection Agency, 26...

  10. Zeolites Modified Metal Cations as Catalysts in Hydrocarbon Oxidation and the Alkyl Alcohol

    Directory of Open Access Journals (Sweden)

    Agadadsh Makhmud Aliyev

    2014-09-01

    Full Text Available The results of studies on the creation of highly metalltceolitnyh systems and the study of their catalytic activities in the oxidation of lower olefin hydrocarbons (ethylene to acetaldehyde, acetone, propylene, butylene methyl ethyl ketone; aliphatic C1-C5 alcohols to their corresponding aldehydes, ketones, carboxylic acids and carboxylic acid esters; oxidative dehydrogenation of naphthenes in the alicyclic diene hydrocarbons and the oxidative dimerization of methane to acetylene. It has been established that the selectivity of these catalysts determined optimal combination of metal components with the acidity and the structure of the zeolite. Selected highly effective catalysts for the reactions studied. Based on the results of experimental studies of the kinetics of the reactions of oxidation of lower olefin hydrocarbons and aliphatic alcohols, the oxidative dehydrogenation of naphthenes and oxidative coupling of methane on the synthesized catalysts are represented by their probable stepwise mechanism and kinetic models developed reactions.

  11. Electrode Design for Low Temperature Direct-Hydrocarbon Solid Oxide Fuel Cells

    Science.gov (United States)

    Chen, Fanglin (Inventor); Zhao, Fei (Inventor); Liu, Qiang (Inventor)

    2015-01-01

    In certain embodiments of the present disclosure, a solid oxide fuel cell is described. The solid oxide fuel cell includes a hierarchically porous cathode support having an impregnated cobaltite cathode deposited thereon, an electrolyte, and an anode support. The anode support includes hydrocarbon oxidation catalyst deposited thereon, wherein the cathode support, electrolyte, and anode support are joined together and wherein the solid oxide fuel cell operates a temperature of 600.degree. C. or less.

  12. Removal of Mercury in Liquid Hydrocarbons using Zeolites Modified with Chitosan and Magnetic Iron Oxide Nanoparticles

    Science.gov (United States)

    Kusrini, E.; Susanto, B. H.; Nasution, D. A.; Jonathan, R.; Khairul, W. M.

    2017-07-01

    Clinoptilolite zeolites were chemically modified with chitosan (Chit) and magnetic iron oxide nanoparticles (Fe3O4NPs) were synthesized for removal of mercury from liquid condensate hydrocarbon. The mercury content was in liquid hydrocarbon which was measured by Lumex mercury analyzer. The performance of sorbents based on zeolites modified chitosan and magnetic nanoparticles were examined on the real liquid condensate hydrocarbon. Removal of mercury using a prestine clinoptilolite zeolites, and zeolites modified chitosan (zeolites-Chit) were ∼4.5, and ∼35%, respectively. The effects of magnetic nanoparticles in zeolites-Chit sorbents were significant to reduce the mercury content in liquid condensate hydrocarbon which were from ∼63 to ∼66%. Increasing the mass ratio of Fe3O4 that influenced to the BET surface area of natural zeolites. Zeolites-Chit-Fe3O4NPs as an efficient sorbents are potential ideal to remove mercury in hydrocarbon for practical applications.

  13. Safety of water treatment by chlorine dioxide oxidation of aromatic hydrocarbons commonly found in water

    Energy Technology Data Exchange (ETDEWEB)

    Taymaz, K.; Williams, D.T.; Benoit, F.M.

    1979-01-01

    The safety of water treatment by chlorine dioxide oxidation of aromatic hydrocarbons commonly found in water and industrial wastewaters in the US was studied by observing the reactions of naphthalene and methylnaphthalenes in essentially chlorine-free, aqueous chlorine dioxide solutions. Naphthalene and methylnaphthalenes yielded chlorinated derivatives and oxidation products. Further research is recommended.

  14. Advances and perspectives in catalytic oxidation of hydrocarbons in liquid phase

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This review article summarizes recent advances in catalytic oxidation of hydrocarbons, especially presents two strategies for activation of C-H bonds or molecular oxygen. Based on our own research results, the applications of the two methods in the oxidation of cyclohexane, toluene and ethyl benzene, etc. are introduced, and the perspectives of the two methods are also discussed.

  15. Hydrocarbon fuel processing of micro solid oxide fuel cell systems[Dissertation 17455

    Energy Technology Data Exchange (ETDEWEB)

    Stutz, M. J.

    2007-07-01

    The scope of this thesis is the numerical and experimental investigation of the fuel processing of a micro solid oxide fuel cell (SOFC) running on hydrocarbon fuel. The goal is to enhance the overall system efficiency by optimization of the reforming process in the steady state and the improvement of the start-up process. Micro SOFC are a potential alternative to the currently used batteries in portable devices. Liquid butane in a cartridge could be the energy source. This dissertation is focused on the fuel processing of the system, namely the reforming and post-combusting processes. The reformer converts the hydrocarbon fuel to a hydrogen rich gas that can be utilized by the SOFC. The post-combustor depletes the toxic and/or explosive gases before leaving the exhaust. Chapter One presents a short introduction to the field of hydrocarbon fuel processing in micro solid oxide fuel cell systems, the next three chapters deal with computational modeling of the transport phenomena inside a micro-reformer, which leads to a better understanding of the chemistry and the physics therein, hence progress in the design and operation parameters. The experimental part (i.e. Chapter Five) of this thesis focuses on the feasibility of a novel hybrid start-up method of a fuel cell system that employs existing components as an additional heat source. In Chapter Two the effect of wall heat conduction on the syngas (hydrogen and carbon monoxide) production of a micro-reformer, representing micro-fabricated channels or monoliths, is investigated. Methane is used as a model hydrocarbon fuel since its heterogeneous reaction path on rhodium is known and validated. The simulations demonstrate that the axial wall conduction strongly influences the performance of the micro-reformer and should not be neglected without a careful a priori investigation of its impact. Methane conversion and hydrogen yield are strongly dependent of the wall inner surface temperature, which is influenced by the

  16. Hydrocarbon fuel processing of micro solid oxide fuel cell systems[Dissertation 17455

    Energy Technology Data Exchange (ETDEWEB)

    Stutz, M. J.

    2007-07-01

    The scope of this thesis is the numerical and experimental investigation of the fuel processing of a micro solid oxide fuel cell (SOFC) running on hydrocarbon fuel. The goal is to enhance the overall system efficiency by optimization of the reforming process in the steady state and the improvement of the start-up process. Micro SOFC are a potential alternative to the currently used batteries in portable devices. Liquid butane in a cartridge could be the energy source. This dissertation is focused on the fuel processing of the system, namely the reforming and post-combusting processes. The reformer converts the hydrocarbon fuel to a hydrogen rich gas that can be utilized by the SOFC. The post-combustor depletes the toxic and/or explosive gases before leaving the exhaust. Chapter One presents a short introduction to the field of hydrocarbon fuel processing in micro solid oxide fuel cell systems, the next three chapters deal with computational modeling of the transport phenomena inside a micro-reformer, which leads to a better understanding of the chemistry and the physics therein, hence progress in the design and operation parameters. The experimental part (i.e. Chapter Five) of this thesis focuses on the feasibility of a novel hybrid start-up method of a fuel cell system that employs existing components as an additional heat source. In Chapter Two the effect of wall heat conduction on the syngas (hydrogen and carbon monoxide) production of a micro-reformer, representing micro-fabricated channels or monoliths, is investigated. Methane is used as a model hydrocarbon fuel since its heterogeneous reaction path on rhodium is known and validated. The simulations demonstrate that the axial wall conduction strongly influences the performance of the micro-reformer and should not be neglected without a careful a priori investigation of its impact. Methane conversion and hydrogen yield are strongly dependent of the wall inner surface temperature, which is influenced by the

  17. 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

  18. Oxidative stress in entomopathogenic fungi grown on insect-like hydrocarbons.

    Science.gov (United States)

    Huarte-Bonnet, Carla; Juárez, M Patricia; Pedrini, Nicolás

    2015-08-01

    Entomopathogenic fungi mostly attack their insect hosts by penetration through the cuticle. The outermost insect surface is covered by a lipid-rich layer, usually composed of very long chain hydrocarbons. These fungi are apt to grow on straight chain hydrocarbons (alkanes) as the sole carbon source. Insect-like hydrocarbons are first hydroxylated by a microsomal P450 monooxygenase system, and then fully catabolized by peroxisomal β-oxidation reactions in Beauveria bassiana. In this review, we will discuss lipid metabolism adaptations in alkane-grown fungi, and how an oxidative stress scenario is established under these conditions. Fungi have to pay a high cost for hydrocarbon utilization; high levels of reactive oxygen species are produced and a concomitant antioxidant response is triggered in fungal cells to cope with this drawback.

  19. Enhanced utilization of oxidants for in situ chemical oxidation of chlorinated and aromatic hydrocarbons

    Science.gov (United States)

    Kang, Namgoo

    Potentially viable strategies were sought for enhanced utilization of potassium permanganate (KMnO4) and Fenton's reagent during in situ chemical oxidation (ISCO). An innovative concept of controlled release of oxidant was introduced and organic-coated, completely or partially microencapsulated KMnO4 (MEPP) particles (874 +/- 377 mum) were created to serve a material that can be specifically targeted to a contaminant source zone. Paraffin wax was employed as the coating material because it is biodegradable, inert to KMnO4, insoluble in water and yet soluble in hydrophobic contaminants such as perchloroethylene (PCE). KMnO4 was released very slowly into water, but the oxidant was rapidly released into PCE. The estimated times for 90% release of the oxidant were 1.6 months, 19.3 years, and 472 years for paraffin wax to KMnO4 mass ratios of 1:1, 2:1 and 5:1, respectively. The MEPP particles preferentially accumulated at the PCE-water interface, and the KMnO4 was rapidly released into PCE (contaminant and the locally high concentrations of KMnO 4 could be achieved at the interfacial region between PCE and water. Fenton's oxidative destruction was investigated for aromatic hydrocarbons (benzene, toluene, ethylbenzene, and o-xylene; BTEX) present as dissolved and adsorbed phases, and chlorinated hydrocarbon (PCE) present mostly as dense non-aqueous phase liquid (DNAPL) (>93% of total PCE mass) in batch reactors (soil: solution = 1 g/L). An enhanced mass removal was observed by combining 300 mM H2O2, 2 mM Fe(III) and 2 mM N-(2-hydroxyethyl)iminodiacetic acid (HEIDA) at near-neutral pH. The PCE degradation was maximal at 600 mM H2O2, 5 mM Fe(III) and 5 mM HEIDA at pH 3. The observed BTEX mass removal rate constants (3.6--7.8 x 10-4 s-1) were compared to the estimated ones (4.1--10.1 x 10-3 s-1) using a semi-quantitative kinetic model. The model sensitivity analyses indicate that iron oxides and soil organic matter could play important roles in the non-specific losses of

  20. Magnetic graphene oxide as adsorbent for the determination of polycyclic aromatic hydrocarbon metabolites in human urine.

    Science.gov (United States)

    Zhu, Linli; Xu, Hui

    2014-09-01

    Detection of monohydroxy polycyclic aromatic hydrocarbons metabolites in urine is an advisable and valid method to assess human environmental exposure to polycyclic aromatic hydrocarbons. In this work, novel Fe3O4/graphene oxide composites were prepared and their application in the magnetic solid-phase extraction of monohydroxy polycyclic aromatic hydrocarbons in urine was investigated by coupling with liquid chromatography and mass spectrometry. In the hybrid material, superparamagnetic Fe3O4 nanoparticles provide fast separation to simplify the analytical process and graphene oxide provides a large functional surface for the adsorption. The prepared magnetic nanocomposites were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and vibrating sample magnetometry. The experimental conditions were optimized systematically. Under the optimal conditions, the recoveries of these compounds were in the range of 98.3-125.2%, the relative standard deviations ranged between 6.8 and 15.5%, and the limits of detection were in the range of 0.01-0.15 ng/mL. The simple, quick, and affordable method was successfully used in the analysis of human urinary monohydroxy polycyclic aromatic hydrocarbons in two different cities. The results indicated that the monohydroxy polycyclic aromatic hydrocarbons level in human urine can provide useful information for environmental exposure to polycyclic aromatic hydrocarbons.

  1. Nitrous oxide emissions in a membrane bioreactor treating saline wastewater contaminated by hydrocarbons.

    Science.gov (United States)

    Mannina, Giorgio; Cosenza, Alida; Di Trapani, Daniele; Laudicina, Vito Armando; Morici, Claudia; Ødegaard, Hallvard

    2016-11-01

    The joint effect of wastewater salinity and hydrocarbons on nitrous oxide emission was investigated. The membrane bioreactor pilot plant was operated with two phases: i. biomass acclimation by increasing salinity from 10gNaClL(-1) to 20gNaClL(-1) (Phase I); ii. hydrocarbons dosing at 20mgL(-1) with a constant salt concentration of 20gNaClL(-1) (Phase II). The Phase I revealed a relationship between nitrous oxide emissions and salinity. During the end of the Phase I, the activity of nitrifiers started to recover, indicating a partial acclimatization. During the Phase II, the hydrocarbon shock induced a temporary inhibition of the biomass with the suppression of nitrous oxide emissions. The results revealed that the oxic tank was the major source of nitrous oxide emission, likely due to the gas stripping by aeration. The joint effect of salinity and hydrocarbons was found to be crucial for the production of nitrous oxide.

  2. Aryl hydrocarbon receptor protects lung adenocarcinoma cells against cigarette sidestream smoke particulates-induced oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Ya-Hsin [Graduate Institute of Basic Medical Science, School of Medicine, China Medical University, Taichung 40402, Taiwan, ROC (China); Huang, Su-Chin; Lin, Chun-Ju; Cheng, Li-Chuan [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Zhunan, Miaoli 35053, Taiwan, ROC (China); Li, Lih-Ann, E-mail: lihann@nhri.org.tw [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Zhunan, Miaoli 35053, Taiwan, ROC (China)

    2012-03-15

    Environmental cigarette smoke has been suggested to promote lung adenocarcinoma progression through aryl hydrocarbon receptor (AhR)-signaled metabolism. However, whether AhR facilitates metabolic activation or detoxification in exposed adenocarcinoma cells remains ambiguous. To address this question, we have modified the expression level of AhR in two human lung adenocarcinoma cell lines and examined their response to an extract of cigarette sidestream smoke particulates (CSSP). We found that overexpression of AhR in the CL1-5 cell line reduced CSSP-induced ROS production and oxidative DNA damage, whereas knockdown of AhR expression increased ROS level in CSSP-exposed H1355 cells. Oxidative stress sensor Nrf2 and its target gene NQO1 were insensitive to AhR expression level and CSSP treatment in human lung adenocarcinoma cells. In contrast, induction of AhR expression concurrently increased mRNA expression of xenobiotic-metabolizing genes CYP1B1, UGT1A8, and UGT1A10 in a ligand-independent manner. It appeared that AhR accelerated xenobiotic clearing and diminished associated oxidative stress by coordinate regulation of a set of phase I and II metabolizing genes. However, the AhR-signaled protection could not shield cells from constant oxidative stress. Prolonged exposure to high concentrations of CSSP induced G0/G1 cell cycle arrest via the p53–p21–Rb1 signaling pathway. Despite no effect on DNA repair rate, AhR facilitated the recovery of cells from growth arrest when CSSP exposure ended. AhR-overexpressing lung adenocarcinoma cells exhibited an increased anchorage-dependent and independent proliferation when recovery from exposure. In summary, our data demonstrated that AhR protected lung adenocarcinoma cells against CSSP-induced oxidative stress and promoted post-exposure clonogenicity. -- Highlights: ► AhR expression level influences cigarette sidestream smoke-induced ROS production. ► AhR reduces oxidative stress by coordinate regulation of

  3. Adsorption of polycyclic aromatic hydrocarbons on graphene oxides and reduced graphene oxides.

    Science.gov (United States)

    Sun, Yubing; Yang, Shubin; Zhao, Guixia; Wang, Qi; Wang, Xiangke

    2013-11-01

    Graphene has attracted increasing attention in multidisciplinary studies because of its unique physical and chemical properties. Herein, the adsorption of polycyclic aromatic hydrocarbons (PAHs), such as naphthalene (NAP), anthracene (ANT), and pyrene (PYR), on reduced graphene oxides (rGOs) and graphene oxides (GOs) as a function of pH, humic acid (HA), and temperature were elucidated by means of a batch technique. For comparison, nonpolar and nonporous graphite were also employed in this study. The increasing of pH from 2 to 11 did not influence the adsorption of PAHs on rGOs, whereas the suppressed adsorption of NAP on rGOs was observed both in the presence of HA and under high-temperature conditions. Adsorption isotherms of PAHs on rGOs were in accordance with the Polanyi-Dubinin-Ashtahhov (PDA) model, providing evidence that pore filling and flat surface adsorption were involved. The saturated adsorbed capacities (in mmol g(-1)) of rGOs for PAHs calculated from the PDA model significantly decreased in the order of NAP>PYR>ANT, which was comparable to the results of theoretical calculations. The pore-filling mechanism dominates the adsorption of NAP on rGOs, but the adsorption mechanisms of ANT and PYR on rGOs are flat surface adsorption.

  4. Solution mining and heating by oxidation for treating hydrocarbon containing formations

    Science.gov (United States)

    Vinegar, Harold J.; Stegemeier, George Leo

    2009-06-23

    A method for treating an oil shale formation comprising nahcolite includes providing a first fluid to a portion of the formation. A second fluid is produced from the portion. The second fluid includes at least some nahcolite dissolved in the first fluid. A controlled amount of oxidant is provided to the portion of the formation. Hydrocarbon fluids are produced from the formation.

  5. Solution mining and heating by oxidation for treating hydrocarbon containing formations

    Science.gov (United States)

    Vinegar, Harold J.; Stegemeier, George Leo

    2009-06-23

    A method for treating an oil shale formation comprising nahcolite includes providing a first fluid to a portion of the formation. A second fluid is produced from the portion. The second fluid includes at least some nahcolite dissolved in the first fluid. A controlled amount of oxidant is provided to the portion of the formation. Hydrocarbon fluids are produced from the formation.

  6. Tuning functionality of photocatalytic materials: an infrared study on hydrocarbon oxidation

    NARCIS (Netherlands)

    Amrollahi Buky, Rezvaneh

    2016-01-01

    The focus of the research described in this thesis was on the engineering and design of effective photocatalysts able to catalyze the oxidative conversion of hydrocarbons. The prepared catalysts were synthesized by using different procedures involving sol gel precursors, and impregnation or photo-de

  7. Microbial production of aliphatic hydrocarbons. Progress report, February 1, 1979-September 30, 1979. [Optimization for commercial oily hydrocarbon production

    Energy Technology Data Exchange (ETDEWEB)

    Tornabene, T G

    1979-09-01

    The neutral lipids of nine species of methanogenic bacteria, two thermoacidophiles, two alkalinophiles and 20 algal samples were analyzed. The major components were C/sub 30/, C/sub 25/, and/or C/sub 20/ acyclic isoprenoid hydrocarbons with a continuous range of hydroisoprenoid homologues. The range or acyclic isoprenoids detected were from C/sub 14/ to C/sub 30/. The neutral lipid composition from these bacteria resembles the isoprenoid distribution isolated from ancient sediments and petroleum. Therefore, these findings may have major implications to biological and biogeochemical evolution. In this connection, samples and cores from ancient sediments and future fossil fuel source beds are being analyzed for these neutral lipids as well as the more polar isopranyl glycerol-ether lipids. The derivation of fossil fuels and the biomass accumulations are the focal points of this phase of the study. Ancient and recent sediments, future source beds, and local esturaries are being enriched for microorganisms to establish a range and capability profile for hydrocarbon production. Only a relatively small percent of the microorganisms isolated demonstrated the ability to synthesize hydrocarbons; however, one particular algal isolate demonstrated that it can synthesize hydrocarbons while in a green physiological stage. Greater production is expected in the brown phase of growth. Hydrocarbon biosynthesis studies were conducted in an attempt to better understand the conditions required to maximize hydrocarbon production. The program involved physical and chemical parameters as well as assays of specifically labelled precusors with a cell free enzyme system to measure their conversions to hydrocarbons. The results have indicated a complex one enzyme system is involved in condensation and reduction of two fatty acids into hydrocarbons.

  8. Measurements of hydrocarbons, oxygenated hydrocarbons, carbon monoxide, and nitrogen oxides in an urban basin in Colorado: Implications for Emission Inventories

    Science.gov (United States)

    Goldan, P. D.; Trainer, M.; Kuster, W. C.; Parrish, D. D.; Carpenter, J.; Roberts, J. M.; Yee, J. E.; Fehsenfeld, F. C.

    1995-11-01

    Concentrations of a wide variety of volatile organic compounds (VOCs) in the C3 to C10 range, CO, NOy (total reactive oxidized nitrogen), SO2, and meteorological parameters were measured concurrently at a site on the western perimeter of Boulder, Colorado, during February 1991. The measurement site, located some 150 m above the Boulder urban basin, receives air masses typifying averaged local sources. The highest hydrocarbon concentrations observed showed little effects of photochemical loss processes and reflect the pattern of the local emission sources. The observed ratios of CO and the VOCs to NOy are compared to those predicted by the 1985 National Acid Precipitation Assessment Program (NAPAP) inventory.These comparisons indicate (1) good agreement for CO/NOY, (2) significant overpredictions by the NAPAP inventory for many of the hydrocarbon to NOY ratios, (3) much more benzene from mobile sources (and less from area sources) than predicted by the NAPAP inventory, and (4) large underpredictions of the light alcohols and carbonyls by the NAPAP inventory. These first two results are in marked contrast to the conclusions of the recent tunnel study reported by Ingalls in 1989. Source profile reconciliation implies substantial input from both a local propane source and gasoline headspace venting.

  9. Non-oxidative dehydro-oligomerization of methane to higher molecular weight hydrocarbons at low temperatures

    Institute of Scientific and Technical Information of China (English)

    王林胜; 徐奕德; 陶龙骧

    1997-01-01

    The non-oxidative dehydro-oligomerization of methane to higher molecular weight hydrocarbons such as aroma tics and C2 hydrocarbons in a low temperature range of 773-973 K with Mo/HZSM-5,Mo-Zr/HZSM-5 and Mo-W/HZSM-5 catalysts is studied.The means for enhancing the activity and stability of the Mo-containing catalysts under the reaction conditions is reported.Quite a stable methane conversion rate of over 10% with a high selectivity to the higher hydrocarbons has been obtained at a temperature of 973 K.Pure methane conversions of about 5.2% and 2.0% have been obtained at 923 and 873 K,respectively.In addition,accompanied by the C2-C3 mixture,tht- methane reaction can be initiated even at a lower temperature and the conversion rate of methane is enhanced by the presence of tne initiator of C2-C3 hydrocarbons.Compared with methane oxidative coupling to ethylene,the novel way for methane transformation is significant and reasonable for its lower reaction temperatures and high selectivity to the desired prod

  10. Cu and Co exchanged ZSM-5 zeolites: activity towards no reduction and hydrocarbon oxidation

    Directory of Open Access Journals (Sweden)

    Martins Leandro

    2006-01-01

    Full Text Available |Cu x|[Si yAl]-MFI and |Co x|[Si yAl]-MFI catalysts were prepared by ion exchange from |Na|[Si yAl]-MFI zeolites (y = 12, 25 and 45. The activity of the catalysts was evaluated in the reduction of NO to N2 in an oxidative atmosphere using propane or methane as reducing agents. The Cu catalysts were only active with propane and they presented higher activity than the Co-based catalysts, the latter being active with both hydrocarbons. H2-TPR and DRS-UV/Vis data allowed correlation between the activity towards NO reduction and the presence of cationic charge-compensating species in the zeolite. It was also verified that the hydrocarbons are preferentially oxidised by O2, a reaction that occurs simultaneously with their oxidation with NO.

  11. Oxidation of polycyclic aromatic hydrocarbons using partially purified laccase from residual compost of agaricus bisporus

    Energy Technology Data Exchange (ETDEWEB)

    Mayolo-Deloisa, K. [Center for Biotechnology Research, Autonomous University of Morelos State, Cuernavaca, Morelos (Mexico); Center for Biotechnology-FEMSA, Monterrey Institute of Technology, Campus Monterrey, Monterrey (Mexico); Machin-Ramirez, C. [Center for Biotechnology Research, Autonomous University of Morelos State, Cuernavaca, Morelos (Mexico); Faculty of Chemical Sciences and Engineering, Autonomous University of Morelos State, Cuernavaca, Morelos (Mexico); Rito-Palomares, M. [Center for Biotechnology-FEMSA, Monterrey Institute of Technology, Campus Monterrey, Monterrey (Mexico); Trejo-Hernandez, M.R. [Center for Biotechnology Research, Autonomous University of Morelos State, Cuernavaca, Morelos (Mexico)

    2011-08-15

    Laccase partially purified from residual compost of Agaricus bisporus by an aqueous two-phase system (Lac ATPS) was used in degrading polycyclic aromatic hydrocarbons: fluorene (Flu), phenanthrene (Phe), anthracene (Ant), benzo[a]pyrene (BaP), and benzo[a]anthracene (BaA). The capacity of the enzyme to oxidize polyaromatic compounds was compared to that of the crude laccase extract (CE). After treatment of 72 h, Lac ATPS and CE were not capable of oxidizing Flu and Phe, while Ant, BaP, and BaA were oxidized, resulting in percentages of oxidation of 11.2 {+-} 1, 26 {+-} 2, and 11.7 {+-} 4 % with CE, respectively. When Lac ATPS was used, the following percentages of oxidation were obtained: 11.4 {+-} 3 % for Ant, 34 {+-} 0.1 % for BaP, and 13.6 {+-} 2 % for BaA. The results reported here demonstrate the potential application of Lac ATPS for the oxidation of polycyclic aromatic hydrocarbons. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Low temperature oxidation of hydrocarbons using an electrochemical reactor

    DEFF Research Database (Denmark)

    Ippolito, Davide

    This study investigated the use of a ceramic porous electrochemical reactor for the deep oxidation of propene. Two electrode composites, La0.85Sr0.15MnO3±d/Ce0.9Gd0.1O1.95 (LSM/CGO) and La0.85Sr0.15FeMnO3/Ce0.9Gd0.1O1.95 (LSF/CGO), were produced in a 5 single cells stacked configuration and used ...

  13. BIODEGRADATION OF MONOAROMATIC HYDROCARBONS BY AQUIFER MICROORGANISMS USING OXYGEN, NITRATE, OR NITROUS OXIDE AS THE TERMINAL ELECTRON ACCEPTOR

    Science.gov (United States)

    Microcosms were prepared from aquifer material, spiked with monoaromatic hydrocarbons, and amended with oxygen, nitrate, and nitrous oxide. Benzene and alkylbenzenes were degraded to concentrations below 5 µg/liter within 7 days under aerobic conditions, whereas only the alkylbe...

  14. Methane Conversion to C2 Hydrocarbons in Solid State Oxide Electrolyte Membrane Reactor

    Institute of Scientific and Technical Information of China (English)

    LI Jun; ZHAO Ling; ZHU Zhong-nan; XI Dan-li

    2005-01-01

    Provskite-type catalysts, Ln0.6 Sr0.4 FexCo1-x O3 (Ln = Nd,Pr, Gd, Sm, La, 0<x<1) and Ln0.8Na0.2CoO3(Ln= La,Gd, Sm) were synthesized, their catalytic properties in the oxidative coupling of methane (OCM) were examined in a fixed-bed reactor. The former group presented higher activity in the OCM, but the main product was carbon dioxide. While the later group showed lower activity but much higher selectivity to C2 hydrocarbons compared with the former. Electrochemical measurements were conducted in a solid oxide membrane reactor with La0.8 Na0.2CoO3 as catalyst. The results showed that methane was oxidized to carbon dioxide and ethane by two parallel reactions. Ethane was oxidized to ethene and carbon dioxide. A fraction of ethene was oxidized deeply to carbon dioxide. The total selectivity to C2 hydrocarbons exceeded 70%. Based on the experimental results, a kinetic model was suggested to describe the reaction results.

  15. Surface chemistry of rare-earth oxide surfaces at ambient conditions: reactions with water and hydrocarbons

    Science.gov (United States)

    Külah, Elçin; Marot, Laurent; Steiner, Roland; Romanyuk, Andriy; Jung, Thomas A.; Wäckerlin, Aneliia; Meyer, Ernst

    2017-01-01

    Rare-earth (RE) oxide surfaces are of significant importance for catalysis and were recently reported to possess intrinsic hydrophobicity. The surface chemistry of these oxides in the low temperature regime, however, remains to a large extent unexplored. The reactions occurring at RE surfaces at room temperature (RT) in real air environment, in particular, in presence of polycyclic aromatic hydrocarbons (PAHs), were not addressed until now. Discovering these reactions would shed light onto intermediate steps occurring in automotive exhaust catalysts before reaching the final high operational temperature and full conversion of organics. Here we first address physical properties of the RE oxide, nitride and fluoride surfaces modified by exposure to ambient air and then we report a room temperature reaction between PAH and RE oxide surfaces, exemplified by tetracene (C18H12) on a Gd2O3. Our study evidences a novel effect – oxidation of higher hydrocarbons at significantly lower temperatures (~300 K) than previously reported (>500 K). The evolution of the surface chemical composition of RE compounds in ambient air is investigated and correlated with the surface wetting. Our surprising results reveal the complex behavior of RE surfaces and motivate follow-up studies of reactions between PAH and catalytic surfaces at the single molecule level. PMID:28327642

  16. Progress of catalytic wet air oxidation technology

    Directory of Open Access Journals (Sweden)

    Guolin Jing

    2016-11-01

    Full Text Available Catalytic wet air oxidation (CWAO is one of the most economical and environmental-friendly advanced oxidation process for high strength, toxic, hazardous and non-biodegradable contaminants under milder conditions, which is developed on the basic of wet air oxidation. Various heterogeneous catalysts including noble metals and metal oxides have been extensively studied to enhance the efficiency of CWAO. The advances in the research on wastewater treatment by CWAO process are summarized in aspects of reaction mechanism investigation, reaction kinetics study and catalyst development. It is pointed out that the preparation of active and stable catalysts, the investigation on reaction mechanisms and the study on reaction kinetics models are very important for the promotion of CWAO application.

  17. Problems in Catalytic Oxidation of Hydrocarbons and Detailed Simulation of Combustion Processes

    Science.gov (United States)

    Xin, Yuxuan

    This dissertation research consists of two parts, with Part I on the kinetics of catalytic oxidation of hydrocarbons and Part II on aspects on the detailed simulation of combustion processes. In Part I, the catalytic oxidation of C1--C3 hydrocarbons, namely methane, ethane, propane and ethylene, was investigated for lean hydrocarbon-air mixtures over an unsupported Pd-based catalyst, from 600 to 800 K and under atmospheric pressure. In Chapter 2, the experimental facility of wire microcalorimetry and simulation configuration were described in details. In Chapter 3 and 4, the oxidation rate of C1--C 3 hydrocarbons is demonstrated to be determined by the dissociative adsorption of hydrocarbons. A detailed surface kinetics model is proposed with deriving the rate coefficient of hydrocarbon dissociative adsorption from the wire microcalorimetry data. In Part II, four fundamental studies were conducted through detailed combustion simulations. In Chapter 5, self-accelerating hydrogen-air flames are studied via two-dimensional detailed numerical simulation (DNS). The increase in the global flame velocity is shown to be caused by the increase of flame surface area, and the fractal structure of the flame front is demonstrated by the box-counting method. In Chapter 6, skeletal reaction models for butane combustion are derived by using directed relation graph (DRG) and DRG-aided sensitivity analysis (DRGASA), and uncertainty minimization by polynomial chaos expansion (MUM-PCE) mothodes. The dependence of model uncertainty is subjected to the completeness of the model. In Chapter 7, a systematic strategy is proposed to reduce the cost of the multicomponent diffusion model by accurately accounting for the species whose diffusivity is important to the global responses of the combustion systems, and approximating those of less importance by the mixture-averaged model. The reduced model is validated in an n-heptane mechanism with 88 species. In Chapter 8, the influence of Soret

  18. 食品中多环芳烃的研究进展%Progress in polycyclic aromatic hydrocarbons in food

    Institute of Scientific and Technical Information of China (English)

    李翠翠; 马宇翔; 陆启玉

    2015-01-01

    The progress in research on the formation mechanism,analytical methods and control measures about polycyclic aromatic hydrocarbons in food was summarized,in order to provide references for solving pollution problems caused by polycyclic aromatic hydrocarbons in food.%简述了近年来关于食品中多环芳烃的形成机理、分析方法及控制措施的研究进展,以期为解决食品中多环芳烃的污染问题提供依据。

  19. Mechanistic studies on the OH-initiated atmospheric oxidation of selected aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Nehr, Sascha

    2012-07-01

    Benzene, toluene, the xylenes, and the trimethylbenzenes are among the most abundant aromatic trace constituents of the atmosphere mainly originating from anthropogenic sources. The OH-initiated atmospheric photo-oxidation of aromatic hydrocarbons is the predominant removal process resulting in the formation of O{sub 3} and secondary organic aerosol. Therefore, aromatics are important trace constituents regarding air pollution in urban environments. Our understanding of aromatic photo-oxidation processes is far from being complete. This work presents novel approaches for the investigation of OH-initiated atmospheric degradation mechanisms of aromatic hydrocarbons. Firstly, pulsed kinetic studies were performed to investigate the prompt HO{sub 2} formation from OH+ aromatic hydrocarbon reactions under ambient conditions. For these studies, the existing OH reactivity instrument, based on the flash photolysis/laser-induced fluorescence (FP/LIF) technique, was extended to the detection of HO{sub 2} radicals. The experimental design allows for the determination of HO{sub 2} formation yields and kinetics. Results of the pulsed kinetic experiments complement previous product studies and help to reduce uncertainties regarding the primary oxidation steps. Secondly, experiments with aromatic hydrocarbons were performed under atmospheric conditions in the outdoor atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction chamber) located at Forschungszentrum Juelich. The experiments were aimed at the evaluation of up-to-date aromatic degradation schemes of the Master Chemical Mechanism (MCMv3.2). The unique combination of analytical instruments operated at SAPHIR allows for a detailed investigation of HO{sub x} and NO{sub x} budgets and for the determination of primary phenolic oxidation product yields. MCMv3.2 deficiencies were identified and most likely originate from shortcomings in the mechanistic representation of ring

  20. Nitric Oxide in Mammary Tumor Progression

    Science.gov (United States)

    1998-07-01

    de Miguel L, Monton M, Casado S, Lopez -Farre A: Endothelial cytosolic proteins bind to the 3’-untranslated region of endothelial nitric oxide...Vazquez AM. Cabrera L, Barral AM, Gen- 38. Morgan DA, Ruscetti FW, Gallo R: Selective in vitro delman R, Jondal M: Toxic effects of interleukin-2

  1. Soot Surface Oxidation in Laminar Hydrocarbon/Air Diffusion Flames at Atmospheric Pressure. Appendix I

    Science.gov (United States)

    Xu, F.; El-Leathy, A. M.; Kim, C. H.; Faeth, G. M.; Yuan, Z.-G. (Technical Monitor); Urban, D. L. (Technical Monitor); Yuan, Z.-G. (Technical Monitor)

    2003-01-01

    Soot surface oxidation was studied experimentally in laminar hydrocarbon/air diffusion flames at atmospheric pressure. Measurements were carried out along the axes of round fuel jets burning in coflowing dry air considering acetylene-nitrogen, ethylene, propyiene-nitrogen, propane and acetylene-benzene-nitrogen in the fuel stream. Measurements were limited to the initial stages of soot oxidation (carbon consumption less than 70%) where soot oxidation occurs at the surface of primary soot particles. The following properties were measured as a function of distance above the burner exit: soot concentrations by deconvoluted laser extinction, soot temperatures by deconvoluted multiline emission, soot structure by thermophoretic sampling and analysis using Transmission Electron Microscopy (TEM), concentrations of major stable gas species (N2, H2O, H2, O2, CO, CO2, CH4, C2H2, C2H6, C3H6, C3H8, and C6H6) by sampling and gas chromatography, concentrations of some radical species (H, OH, O) by deconvoluted Li/LiOH atomic absorption and flow velocities by laser velocimetry. For present test conditions, it was found that soot surface oxidation rates were not affected by fuel type, that direct rates of soot surface oxidation by O2 estimated from Nagle and Strickland-Constable (1962) were small compared to observed soot surface oxidation rates because soot surface oxidation was completed near the flame sheet where O2 concentrations were less than 3% by volume, and that soot surface oxidation rates were described by the OH soot surface oxidation mechanism with a collision efficiency of 0.14 and an uncertainty (95% confidence) of +/- 0.04 when allowing for direct soot surface oxidation by O2, which is in reasonably good agreement with earlier observations of soot surface oxidation rates in both premixed and diffusion flames at atmospheric pressure.

  2. Measurements of vertical distributions of bromine oxide, iodine oxide, oxygenated hydrocarbons and ozone over the Eastern Tropical Pacific Ocean

    Science.gov (United States)

    Volkamer, R. M.; Baidar, S.; Dix, B. K.; Apel, E. C.; Hornbrook, R. S.; Pierce, B.; Gao, R.

    2012-12-01

    As part of the Tropical Ocean tRoposphere Exchange of Reactive halogen species and Oxygenated VOC (TORERO) field experiment 17 research flights were conducted with the NSF/NCAR GV aircraft equipped with a combination of chemical in-situ sensors, and remote sensing instruments to characterize air-sea exchange of reactive halogen species, oxygenated hydrocarbons, and aerosols, and their transport into the free troposphere, over different ocean environments of the Humboldt current in the Eastern Tropical Pacific Ocean (42S to 14N Lat.; 70W to 105W Long.). This presentation presents measurements of the spatial distributions of halogen oxide radicals, oxygenated hydrocarbons, and discusses their impact on ozone destruction rates, and the oxidation of atmospheric mercury. Air mass history is assessed by means of the Real-time Air Quality Modeling System (RAQMS), a global meteorological, chemical and aerosol assimilation/forecasting system that assimilates real-time stratospheric ozone retrievals from the Microwave Limb Sounder (MLS), total column ozone from the Ozone Monitoring Instrument (OMI), and aerosol optical depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS). Reactive halogen species and organic carbon are important in the atmosphere, because they modify HOx radical abundances, influence the reactive chemistry and lifetime of climate active gases (e.g., ozone, methane, dimethyl sulfide), modify aerosol-cloud interactions; halogen radicals can further oxidize atmospheric mercury.

  3. Hydrogen production with short contact time. Catalytic partial oxidation of hydrocarbons and oxygenated compounds: Recent advances in pilot- and bench-scale testing and process design

    Energy Technology Data Exchange (ETDEWEB)

    Guarinoni, A.; Ponzo, R.; Basini, L. [ENI Refining and Marketing Div., San Donato Milanese (Italy)

    2010-12-30

    ENI R and D has been active for fifteen years in the development of Short Contact Time - Catalytic Partial Oxidation (SCT-CPO) technologies for producing Hydrogen/Synthesis Gas. From the beginning the experimental work addressed either at defining the fundamental principles or the technical and economical potential of the technology. Good experimental responses, technical solutions' simplicity and flexibility, favourable techno-economical evaluations promoted the progressive widening of the field of the investigations. From Natural Gas (NG) the range of ''processable'' Hydrocarbons extended to Liquefied Petroleum Gas (LPG) and Gasoils, including those characterised by high levels of unsaturated and sulphurated molecules and, lately, to other compounds with biological origin. The extensive work led to the definition of different technological solutions, grouped as follows: Technology 1: Air Blown SCT-CPO of Gaseous Hydrocarbons and/or Light Compounds with biological origin Technology 2: Enriched Air/Oxygen Blown SCT-CPO of Gaseous Hydrocarbons and/or Light Compounds with biological origin Technology 3: Enriched Air/Oxygen Blown SCT-CPO of Liquid Hydrocarbons and/or Compounds with biological origin Recently, the licence rights on a non-exclusive basis for the commercialisation of SCT-CPO based processes for H{sub 2}/Synthesis gas production from light hydrocarbons with production capacity lower than 5,000 Nm{sup 3}/h of H{sub 2} or 7,500 Nm3/h of syngas have been assigned to two external companies. In parallel, development of medium- and large-scale plant solutions is progressing within the ENI group framework. These last activities are addressed to the utilisation of SCT-CPO for matching the variable Hydrogen demand in several contexts of oil refining operation. This paper will report on the current status of SCT-CPO with a focus on experimental results obtained, either at pilot- and bench- scale level. (orig.)

  4. Low temperature removal of surface oxides and hydrocarbons from Ge(100) using atomic hydrogen

    Science.gov (United States)

    Walker, M.; Tedder, M. S.; Palmer, J. D.; Mudd, J. J.; McConville, C. F.

    2016-08-01

    Germanium is a group IV semiconductor with many current and potential applications in the modern semiconductor industry. Key to expanding the use of Ge is a reliable method for the removal of surface contamination, including oxides which are naturally formed during the exposure of Ge thin films to atmospheric conditions. A process for achieving this task at lower temperatures would be highly advantageous, where the underlying device architecture will not diffuse through the Ge film while also avoiding electronic damage induced by ion irradiation. Atomic hydrogen cleaning (AHC) offers a low-temperature, damage-free alternative to the common ion bombardment and annealing (IBA) technique which is widely employed. In this work, we demonstrate with X-ray photoelectron spectroscopy (XPS) that the AHC method is effective in removing surface oxides and hydrocarbons, yielding an almost completely clean surface when the AHC is conducted at a temperature of 250 °C. We compare the post-AHC cleanliness and (2 × 1) low energy electron diffraction (LEED) pattern to that obtained via IBA, where the sample is annealed at 600 °C. We also demonstrate that the combination of a sample temperature of 250 °C and atomic H dosing is required to clean the surface. Lower temperatures prove less effective in removal of the oxide layer and hydrocarbons, whilst annealing in ultra-high vacuum conditions only removes weakly bound hydrocarbons. Finally, we examine the subsequent H-termination of an IBA-cleaned sample using XPS, LEED and ultraviolet photoelectron spectroscopy (UPS) in order to examine changes in the work function of Ge(100) upon hydrogenation.

  5. Low temperature removal of surface oxides and hydrocarbons from Ge(100) using atomic hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Walker, M., E-mail: m.walker@warwick.ac.uk; Tedder, M.S.; Palmer, J.D.; Mudd, J.J.; McConville, C.F.

    2016-08-30

    Highlights: • Preparation of a clean, well-ordered Ge(100) surface with atomic hydrogen. • Surface oxide layers removed by AHC at room temperature, but not hydrocarbons. • Increasing surface temperature during AHC dramatically improves efficiency. • AHC with the surface heated to 250 °C led to a near complete removal of contaminants. • (2 × 1) LEED pattern from IBA and AHC indicates asymmetric dimer reconstruction. - Abstract: Germanium is a group IV semiconductor with many current and potential applications in the modern semiconductor industry. Key to expanding the use of Ge is a reliable method for the removal of surface contamination, including oxides which are naturally formed during the exposure of Ge thin films to atmospheric conditions. A process for achieving this task at lower temperatures would be highly advantageous, where the underlying device architecture will not diffuse through the Ge film while also avoiding electronic damage induced by ion irradiation. Atomic hydrogen cleaning (AHC) offers a low-temperature, damage-free alternative to the common ion bombardment and annealing (IBA) technique which is widely employed. In this work, we demonstrate with X-ray photoelectron spectroscopy (XPS) that the AHC method is effective in removing surface oxides and hydrocarbons, yielding an almost completely clean surface when the AHC is conducted at a temperature of 250 °C. We compare the post-AHC cleanliness and (2 × 1) low energy electron diffraction (LEED) pattern to that obtained via IBA, where the sample is annealed at 600 °C. We also demonstrate that the combination of a sample temperature of 250 °C and atomic H dosing is required to clean the surface. Lower temperatures prove less effective in removal of the oxide layer and hydrocarbons, whilst annealing in ultra-high vacuum conditions only removes weakly bound hydrocarbons. Finally, we examine the subsequent H-termination of an IBA-cleaned sample using XPS, LEED and ultraviolet

  6. Treatability assessment of polycyclic aromatic hydrocarbons contaminated marine sediments using permanganate, persulfate and Fenton oxidation processes.

    Science.gov (United States)

    Shih, Yu-Jen; Binh, Nguyen Thanh; Chen, Chiu-Wen; Chen, Chih-Feng; Dong, Cheng-Di

    2016-05-01

    Various chemical oxidation techniques, such as potassium permanganate (KMnO4), sodium persulfate (Na2S2O8), Fenton (H2O2/Fe(2+)), and the modified persulfate and Fenton reagents (activated by ferrous complexes), were carried out to treat marine sediments that were contaminated with polycyclic aromatic hydrocarbons (PAHs) and dredged from Kaohsiung Harbor in Taiwan. Experimental results revealed that KMnO4 was the most effective of the tested oxidants in PAH degradation. Owing to the high organic matter content in the sediment that reduced the efficiencies of Na2S2O8 and regular Fenton reactions, a large excess of oxidant was required. Nevertheless, KH2PO4, Na4P2O7 and four chelating agents (EDTA, sodium citrate, oxalic acid, and sodium oxalate) were utilized to stabilize Fe(II) in activating the Na2S2O8 and Fenton oxidations, while Fe(II)-citrate remarkably promoted the PAH degradation. Increasing the molecular weight and number of rings of PAH did not affect the overall removal efficiencies. The correlation between the effectiveness of the oxidation processes and the physicochemical properties of individual PAH was statistically analyzed. The data implied that the reactivity of PAH (electron affinity and ionization potential) affected its treatability more than did its hydrophobicity (Kow, Koc and Sw), particularly using experimental conditions under which PAHs could be effectively oxidized.

  7. Soot Oxidation in Laminar Hydrocarbon/Air Diffusion Flames at Atmospheric Pressure. Appendix D

    Science.gov (United States)

    Xu, F.; El-Leathy, A. M.; Faeth, G. M.

    2000-01-01

    Soot oxidation was studied experimentally in laminar hydrocarbon/air diffusion flames at atmospheric pressure. Measurements were carried out along the axes of round jets burning in coflowing air considering acetylene, ethylene, proplyene and propane as fuels. Measurements were limited to the initial stages of soot oxidation (carbon consumption less than 70%) where soot oxidation mainly occurs at the surface of primary soot particles. The following properties were measured as a function of distance above the burner exit: soot concentrations by deconvoluted laser extinction, soot temperatures by deconvoluted multiline emission, soot structure by thermophoretic sampling and analysis using Transmission Electron Microscopy (TEM), concentrations of stable major gas species (N2, H2O, H2, 02, CO, CO2, CH4, C2H2, C2H4, C2H6, C3H6, and C3H8) by sampling and gas chromatography, concentrations of some radical species (H, OH, O) by the deconvoluted Li/LiOH atomic absorption technique and flow velocities by laser velocimetry. It was found that soot surface oxidation rates are not particularly affected by fuel type for laminar diffusion flames and are described reasonably well by the OH surface oxidation mechanism with a collision efficiency of 0.10, (standard deviation of 0.07) with no significant effect of fuel type in this behavior; these findings are in good agreement with the classical laminar premixed flame measurements of Neoh et al. Finally, direct rates of surface oxidation by O2 were small compared to OH oxidation for present conditions, based on estimated O2 oxidation rates due to Nagle and Strickland-Constable, because soot oxidation was completed near the flame sheet where O2 concentrations were less than 1.2% by volume.

  8. Soot Oxidation in Hydrocarbon/Air Diffusion Flames at Atmospheric Pressure. Appendix K

    Science.gov (United States)

    Xu, F.; El-Leathy, A. M.; Faeth, G. M.; Urban, D. L. (Technical Monitor); Yuan, Z.-G. (Technical Monitor)

    2001-01-01

    Soot oxidation was studied experimentally in laminar hydrocarbon/air diffusion flames at atmospheric pressure. Measurements were carried out along the axes of round jets burning in coflowing air considering acetylene, ethylene, propylene and propane as fuels. Measurements were limited to the initial stages of soot oxidation (carbon consumption less than 70%) where soot oxidation mainly occurs at the surface of primary soot particles. The following properties were measured as a function of distance above the burner exit: soot concentrations by deconvoluted laser extinction, soot temperatures by deconvoluted multiline emission, soot structure by thermophoretic sampling and analysis using Transmission Electron Microscopy (TEM), concentrations of stable major gas species (N2, H2O, H2, O2, CO, CO2, CH4, C2H2,C2H4, C2H6, C3H6, and C3H8) by sampling and gas chromatography, concentrations of some radical species (H, OH, O) by the deconvoluted Li/LiOH atomic absorption technique and flow velocities by laser velocimetry. It was found that soot surface oxidation rates are not particularly affected by fuel type for laminar diffusion flames and are described reasonably well by the OH surface oxidation mechanism with a collision efficiency of 0.10, (standard deviation of 0.07) with no significant effect of fuel type in this behavior; these findings are in good agreement with the classical laminar premixed flame measurements of Neoh et al. Finally, direct rates of surface oxidation by O2 were small compared to OH oxidation for present conditions, based on estimated O2 oxidation rates due to Nagle and Strickland-Constable (1962), because soot oxidation was completed near the flame sheet where O2 concentrations were less than 1.2% by volume.

  9. Hydrocarbon oxidation catalyzed by vanadium polyoxometalate supported on mesoporous MCM-41 under ultrasonic irradiation.

    Science.gov (United States)

    Tangestaninejad, Shahram; Mirkhani, Valiollah; Moghadam, Majid; Mohammadpoor-Baltork, Iraj; Shams, Esmaeil; Salavati, Hossein

    2008-04-01

    Vanadium polyoxometalate (PVMo) supported on mesoporous MCM-41, MCM-41-NH(2), as efficient and heterogeneous catalysts, with large surface area, for hydrocarbon oxidation with hydrogen peroxide is reported. Oxidation of the alkenes and alkanes gave product selectivities, which are similar to those observed for corresponding homogeneous catalyst. PVMo-MCM was prepared by introduction of PVMo into the mesoporous molecule sieves of MCM-41 by impregnation and adsorption techniques. The samples were characterized by X-ray diffraction (XRD), thermal gravimetric-differential thermal analysis (TG-DTA), FT-IR, scanning electron microscopy (SEM), UV-Vis and cyclic voltametry (CV). Ultrasonic irradiation has a particular effect on MCM-41 structural uniformity and reduced the reaction times and improved the product yields. In addition, the solid catalysts could be recovered and reused several times without loss of its activity.

  10. A novel layered perovskite as symmetric electrode for direct hydrocarbon solid oxide fuel cells

    Science.gov (United States)

    Zhao, Ling; Chen, Kongfa; Liu, Yuanxu; He, Beibei

    2017-02-01

    Layered perovskite oxides are well known to possess significant electronic, magnetic and electrochemical properties. Herein, we highlight a novel layered perovskite PrBaMn1.5Fe0.5O5+δ (PBMFO) as electrodes of symmetrical solid oxide fuel cells (SSOFCs). The layered PBMFO shows high electrical conductivity of 112.5 and 7.4 S cm-1 at 800 °C in air and 5% H2/Ar, respectively. The single cell with PBMFO symmetric electrodes achieves peak power density of 0.54 W cm-2 at 800 °C using humidified hydrogen as fuel. Moreover, PBMFO electrodes demonstrate good redox stability and high coking tolerance against hydrocarbon fuel.

  11. Effect of hydrocarbon adsorption on the wettability of rare earth oxide ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Preston, Daniel J.; Miljkovic, Nenad; Sack, Jean; Queeney, John; Wang, Evelyn N., E-mail: enwang@mit.edu [Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Enright, Ryan [Thermal Management Research Group, Efficient Energy Transfer (etaET) Department, Bell Labs Ireland, Dublin 15 (Ireland)

    2014-07-07

    Vapor condensation is routinely used as an effective means of transferring heat, with dropwise condensation exhibiting a 5 − 7x heat transfer improvement compared to filmwise condensation. However, state-of-the-art techniques to promote dropwise condensation rely on functional hydrophobic coatings, which are often not robust and therefore undesirable for industrial implementation. Natural surface contamination due to hydrocarbon adsorption, particularly on noble metals, has been explored as an alternative approach to realize stable dropwise condensing surfaces. While noble metals are prohibitively expensive, the recent discovery of robust rare earth oxide (REO) hydrophobicity has generated interest for dropwise condensation applications due to material costs approaching 1% of gold; however, the underlying mechanism of REO hydrophobicity remains under debate. In this work, we show through careful experiments and modeling that REO hydrophobicity occurs due to the same hydrocarbon adsorption mechanism seen previously on noble metals. To investigate adsorption dynamics, we studied holmia and ceria REOs, along with control samples of gold and silica, via X-Ray photoelectron spectroscopy (XPS) and dynamic time-resolved contact angle measurements. The contact angle and surface carbon percent started at ≈0 on in-situ argon-plasma-cleaned samples and increased asymptotically over time after exposure to laboratory air, with the rare earth oxides displaying hydrophobic (>90°) advancing contact angle behavior at long times (>4 days). The results indicate that REOs are in fact hydrophilic when clean and become hydrophobic due to hydrocarbon adsorption. Furthermore, this study provides insight into how REOs can be used to promote stable dropwise condensation, which is important for the development of enhanced phase change surfaces.

  12. Effect of hydrocarbon adsorption on the wettability of rare earth oxide ceramics

    Science.gov (United States)

    Preston, Daniel J.; Miljkovic, Nenad; Sack, Jean; Enright, Ryan; Queeney, John; Wang, Evelyn N.

    2014-07-01

    Vapor condensation is routinely used as an effective means of transferring heat, with dropwise condensation exhibiting a 5 - 7x heat transfer improvement compared to filmwise condensation. However, state-of-the-art techniques to promote dropwise condensation rely on functional hydrophobic coatings, which are often not robust and therefore undesirable for industrial implementation. Natural surface contamination due to hydrocarbon adsorption, particularly on noble metals, has been explored as an alternative approach to realize stable dropwise condensing surfaces. While noble metals are prohibitively expensive, the recent discovery of robust rare earth oxide (REO) hydrophobicity has generated interest for dropwise condensation applications due to material costs approaching 1% of gold; however, the underlying mechanism of REO hydrophobicity remains under debate. In this work, we show through careful experiments and modeling that REO hydrophobicity occurs due to the same hydrocarbon adsorption mechanism seen previously on noble metals. To investigate adsorption dynamics, we studied holmia and ceria REOs, along with control samples of gold and silica, via X-Ray photoelectron spectroscopy (XPS) and dynamic time-resolved contact angle measurements. The contact angle and surface carbon percent started at ≈0 on in-situ argon-plasma-cleaned samples and increased asymptotically over time after exposure to laboratory air, with the rare earth oxides displaying hydrophobic (>90°) advancing contact angle behavior at long times (>4 days). The results indicate that REOs are in fact hydrophilic when clean and become hydrophobic due to hydrocarbon adsorption. Furthermore, this study provides insight into how REOs can be used to promote stable dropwise condensation, which is important for the development of enhanced phase change surfaces.

  13. Raman and photoelectron spectroscopic investigation of high-purity niobium materials: Oxides, hydrides, and hydrocarbons

    Science.gov (United States)

    Singh, Nageshwar; Deo, M. N.; Nand, Mangla; Jha, S. N.; Roy, S. B.

    2016-09-01

    We present investigations of the presence of oxides, hydrides, and hydrocarbons in high-purity (residual resistivity ratio, ˜300) niobium (Nb) materials used in fabrication of superconducting radio frequency (SRF) cavities for particle accelerators. Raman spectroscopy of Nb materials (as-received from the vendor as well as after surface chemical- and thermal processing) revealed numerous peaks, which evidently show the presence of oxides (550 cm-1), hydrides (1277 and 1385 cm-1: ˜80 K temperature), and groups of hydrocarbons (1096, 2330, 2710, 2830, 2868, and 3080 cm-1). The present work provides direct spectroscopic evidence of hydrides in the electropolished Nb materials typically used in SRF cavities. Raman spectroscopy thus can provide vital information about the near-surface chemical species in niobium materials and will help in identifying the cause for the performance degradation of SRF cavities. Furthermore, photoelectron spectroscopy was performed on the Nb samples to complement the Raman spectroscopy study. This study reveals the presence of C and O in the Nb samples. Core level spectra of Nb (doublet 3d5/2 and 3d3/2) show peaks near 206.6 and 209.4 eV, which can be attributed to the Nb5+ oxidation state. The core level spectra of C 1 s of the samples are dominated by graphitic carbon (binding energy, 284.6 eV), while the spectra of O 1 s are asymmetrically peaked near binding energy of ˜529 eV, and that indicates the presence of metal-oxide Nb2O5. The valence-band spectra of the Nb samples are dominated by a broad peak similar to O 2p states, but after sputtering (for 10 min) a peak appears at ˜1 eV, which is a feature of the elemental Nb atom.

  14. Low-Temperature CO Oxidation over a Ternary Oxide Catalyst with High Resistance to Hydrocarbon Inhibition.

    Science.gov (United States)

    Binder, Andrew J; Toops, Todd J; Unocic, Raymond R; Parks, James E; Dai, Sheng

    2015-11-02

    Platinum group metal (PGM) catalysts are the current standard for control of pollutants in automotive exhaust streams. Aside from their high cost, PGM catalysts struggle with CO oxidation at low temperatures (oxide catalyst composed of copper oxide, cobalt oxide, and ceria (dubbed CCC) that outperforms synthesized and commercial PGM catalysts for CO oxidation in simulated exhaust streams while showing no signs of inhibition by propene. Diffuse reflectance IR (DRIFTS) and light-off data both indicate low interaction between propene and the CO oxidation active site on this catalyst, and a separation of adsorption sites is proposed as the cause of this inhibition resistance. This catalyst shows great potential as a low-cost component for low temperature exhaust streams that are expected to be a characteristic of future automotive systems. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Environmental analysis of endocrine disrupting effects from hydrocarbon contaminants in the ecosystem. 1998 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    McLachlan, J.

    1998-06-01

    'The objective of this project is to determine how environmental contaminants, namely hydrocarbons, can act as hormones or anti-hormones (i.e., environmental hormones) in different species present in aquatic ecosystems. Species of particular focus are those which can serve as sentinel species (e.g., amphibians) and, thus, provide early warning signals for more widespread impacts on an ecosystem and its wildlife and human inhabitants. This reports the progress of 1.5 years of a three-year grant awarded to the Tulane/Xavier Center for Bioenvironmental Research (CBR). A growing body of evidence suggests that chemicals in the environment can disrupt the endocrine system of animals (i.e., wildlife and humans) and adversely impact the development of these species. Because of the multitude of known endocrine-disrupting chemicals and the numerous industrial and government sectors producing these chemicals, almost every federal agency has initiated research on the endocrine effects of chemicals relevant to their operations. This study represents the Department of Energy (DOE) Basic Energy Sciences'' only research on the impacts of endocrine-disrupting chemicals. The activities employed by this project to determine these impacts include development of biotechnology screens (in vitro), animal screens (in vivo), and other analyses of aquatic ecosystem biomarkers of exposure. The results from this study can elucidate how chemicals in the environment, including those from DOE activities, can signal (and alter) the development of a number of species in aquatic ecosystems. These signals can have detrimental impacts not only on an organismal level, but also on community, population, and entire ecosystem levels, including humans.'

  16. Use of Advanced Oxidation and Aerobic Degradation for Remediation of Various Hydrocarbon Contaminates

    Energy Technology Data Exchange (ETDEWEB)

    Paul Fallgren

    2009-03-06

    Western Research Institute in conjunction with Sierra West Consultants, Inc., Tetra Tech, Inc., and the U.S. Department of Energy conducted laboratory and field studies to test different approaches to enhance degradation of hydrocarbons and associated contaminants. WRI in conjunction with Sierra West Consultants, Inc., conducted a laboratory and field study for using ozone to treat a site contaminated with MTBE and other hydrocarbons. Results from this study demonstrate that a TOD test can be used to resolve the O{sub 3} dosage problem by establishing a site-specific benchmark dosage for field ozone applications. The follow-up testing of the laboratory samples provided indications that intrinsic biodegradation could be stimulated by adding oxygen. Laboratory studies also suggests that O3 dosage in the full-scale field implementation could be dialed lower than stoichiometrically designed to eliminate the formation of Cr(VI). WRI conducted a study involving a series of different ISCO oxidant applications to diesel-contaminated soil and determined the effects on enhancing biodegradation to degrade the residual hydrocarbons. Soils treated with permanganate followed by nutrients and with persulfate followed by nutrients resulted in the largest decrease in TPH. The possible intermediates and conditions formed from NOM and TPH oxidation by permanganate and activated persulfate favors microbial TPH degrading activity. A 'passive-oxidation' method using microbial fuel cell (MFC) technology was conducted by WRI in conjunction with Tetra Tech, Inc., to degrade MTBE in groundwater. These experiments have demonstrated that a working MFC (i.e., one generating power) could be established in the laboratory using contaminated site water or buffered media inoculated with site water and spiked with MTBE, benzene, or toluene. Electrochemical methods were studied by WRI with goal of utilizing low voltage and amperage electrical sources for 'geo-oxidation' of organic

  17. Method of preparing and utilizing a catalyst system for an oxidation process on a gaseous hydrocarbon stream

    Science.gov (United States)

    Berry, David A; Shekhawat, Dushyant; Smith, Mark; Haynes, Daniel

    2013-07-16

    The disclosure relates to a method of utilizing a catalyst system for an oxidation process on a gaseous hydrocarbon stream with a mitigation of carbon accumulation. The system is comprised of a catalytically active phase deposited onto an oxygen conducting phase, with or without supplemental support. The catalytically active phase has a specified crystal structure where at least one catalytically active metal is a cation within the crystal structure and coordinated with oxygen atoms within the crystal structure. The catalyst system employs an optimum coverage ratio for a given set of oxidation conditions, based on a specified hydrocarbon conversion and a carbon deposition limit. Specific embodiments of the catalyst system are disclosed.

  18. Degradation kinetics of chlorinated aliphatic hydrocarbons by methane oxidizers naturally-associated with wetland plant roots

    Science.gov (United States)

    Powell, C. L.; Goltz, M. N.; Agrawal, A.

    2014-12-01

    Chlorinated aliphatic hydrocarbons (CAHs) are common groundwater contaminants that can be removed from the environment by natural attenuation processes. CAH biodegradation can occur in wetland environments by reductive dechlorination as well as oxidation pathways. In particular, CAH oxidation may occur in vegetated wetlands, by microorganisms that are naturally associated with the roots of wetland plants. The main objective of this study was to evaluate the cometabolic degradation kinetics of the CAHs, cis-1,2-dichloroethene (cisDCE), trichloroethene (TCE), and 1,1,1-trichloroethane (1,1,1TCA), by methane-oxidizing bacteria associated with the roots of a typical wetland plant in soil-free system. Laboratory microcosms with washed live roots investigated aerobic, cometabolic degradation of CAHs by the root-associated methane-oxidizing bacteria at initial aqueous [CH4] ~ 1.9 mg L- 1, and initial aqueous [CAH] ~ 150 μg L- 1; cisDCE and TCE (in the presence of 1,1,1TCA) degraded significantly, with a removal efficiency of approximately 90% and 46%, respectively. 1,1,1TCA degradation was not observed in the presence of active methane oxidizers. The pseudo first-order degradation rate-constants of TCE and cisDCE were 0.12 ± 0.01 and 0.59 ± 0.07 d- 1, respectively, which are comparable to published values. However, their biomass-normalized degradation rate constants obtained in this study were significantly smaller than pure-culture studies, yet they were comparable to values reported for biofilm systems. The study suggests that CAH removal in wetland plant roots may be comparable to processes within biofilms. This has led us to speculate that the active biomass may be on the root surface as a biofilm. The cisDCE and TCE mass losses due to methane oxidizers in this study offer insight into the role of shallow, vegetated wetlands as an environmental sink for such xenobiotic compounds.

  19. Polycyclic Aromatic Hydrocarbon Metabolism by White Rot Fungi and Oxidation by Coriolopsis gallica UAMH 8260 Laccase

    Science.gov (United States)

    Pickard, Michael A.; Roman, Rosa; Tinoco, Raunel; Vazquez-Duhalt, Rafael

    1999-01-01

    We studied the metabolism of polycyclic aromatic hydrocarbons (PAHs) by using white rot fungi previously identified as organisms that metabolize polychlorinated biphenyls. Bran flakes medium, which has been shown to support production of high levels of laccase and manganese peroxidase, was used as the growth medium. Ten fungi grown for 5 days in this medium in the presence of anthracene, pyrene, or phenanthrene, each at a concentration of 5 μg/ml could metabolize these PAHs. We studied the oxidation of 10 PAHs by using laccase purified from Coriolopsis gallica. The reaction mixtures contained 20 μM PAH, 15% acetonitrile in 60 mM phosphate buffer (pH 6), 1 mM 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonate) (ABTS), and 5 U of laccase. Laccase exhibited 91% of its maximum activity in the absence of acetonitrile. The following seven PAHs were oxidized by laccase: benzo[a]pyrene, 9-methylanthracene, 2-methylanthracene, anthracene, biphenylene, acenaphthene, and phenanthrene. There was no clear relationship between the ionization potential of the substrate and the first-order rate constant (k) for substrate loss in vitro in the presence of ABTS. The effects of mediating substrates were examined further by using anthracene as the substrate. Hydroxybenzotriazole (HBT) (1 mM) supported approximately one-half the anthracene oxidation rate (k = 2.4 h−1) that ABTS (1 mM) supported (k = 5.2 h−1), but 1 mM HBT plus 1 mM ABTS increased the oxidation rate ninefold compared with the oxidation rate in the presence of ABTS, to 45 h−1. Laccase purified from Pleurotus ostreatus had an activity similar to that of C. gallica laccase with HBT alone, with ABTS alone, and with 1 mM HBT plus 1 mM ABTS. Mass spectra of products obtained from oxidation of anthracene and acenaphthene revealed that the dione derivatives of these compounds were present. PMID:10473379

  20. Degradation kinetics of chlorinated aliphatic hydrocarbons by methane oxidizers naturally-associated with wetland plant roots.

    Science.gov (United States)

    Powell, C L; Goltz, M N; Agrawal, A

    2014-12-01

    Chlorinated aliphatic hydrocarbons (CAHs) are common groundwater contaminants that can be removed from the environment by natural attenuation processes. CAH biodegradation can occur in wetland environments by reductive dechlorination as well as oxidation pathways. In particular, CAH oxidation may occur in vegetated wetlands, by microorganisms that are naturally associated with the roots of wetland plants. The main objective of this study was to evaluate the cometabolic degradation kinetics of the CAHs, cis-1,2-dichloroethene (cisDCE), trichloroethene (TCE), and 1,1,1-trichloroethane (1,1,1TCA), by methane-oxidizing bacteria associated with the roots of a typical wetland plant in soil-free system. Laboratory microcosms with washed live roots investigated aerobic, cometabolic degradation of CAHs by the root-associated methane-oxidizing bacteria at initial aqueous [CH4] ~1.9mgL(-1), and initial aqueous [CAH] ~150μgL(-1); cisDCE and TCE (in the presence of 1,1,1TCA) degraded significantly, with a removal efficiency of approximately 90% and 46%, respectively. 1,1,1TCA degradation was not observed in the presence of active methane oxidizers. The pseudo first-order degradation rate-constants of TCE and cisDCE were 0.12±0.01 and 0.59±0.07d(-1), respectively, which are comparable to published values. However, their biomass-normalized degradation rate constants obtained in this study were significantly smaller than pure-culture studies, yet they were comparable to values reported for biofilm systems. The study suggests that CAH removal in wetland plant roots may be comparable to processes within biofilms. This has led us to speculate that the active biomass may be on the root surface as a biofilm. The cisDCE and TCE mass losses due to methane oxidizers in this study offer insight into the role of shallow, vegetated wetlands as an environmental sink for such xenobiotic compounds.

  1. Estimates for biogenic non-methane hydrocarbons and nitric oxide emissions in the Valley of Mexico

    Science.gov (United States)

    Velasco, Erik

    Biogenic non-methane hydrocarbons (NMHC), 2-methyl-3-buten-2-ol (methylbutenol or MBO) and nitrogen oxide (NO) emissions were estimated for the Valley of Mexico developing a spatially and temporally resolved emission inventory for air quality models. The modeling domain includes all the Metropolitan Mexico City Area, the surrounding forests and agriculture fields. The estimates were based on several sources of land use and land cover data and a biogenic emission model; the biomass density and tree characteristics were obtained from reforestation program data. The biogenic emissions depend also on climatic conditions, mainly temperature and solar radiation. The temperature was obtained from a statistical revision of the last 10 yr data reported by the Mexico City Automatic Atmospheric Monitoring Network, while the solar radiation data were obtained from measurements performed in a typical oak forest in the Valley and from sources of total solar radiation data for Mexico City. The results indicated that 7% of total hydrocarbon emissions in Mexico Valley are due to vegetation and NO emissions from soil contribute with 1% to the total NO x emissions.

  2. Progress in base-metal water oxidation catalysis.

    Science.gov (United States)

    Parent, Alexander Rene; Sakai, Ken

    2014-08-01

    This minireview provides a brief overview of the progress that has been made in developing homogeneous water oxidation catalysts based on base metals (manganese, iron, cobalt, nickel, and copper) from the 1990s to mid-2014. The impact of each contribution is analyzed, and opportunities for further improvement are noted. In addition, the relative stabilities of the base-metal catalysts that have been reported are compared to illustrate the importance of developing more robust catalytic systems by using these metals. This manuscript is intended to provide a firm foundation for researchers entering the field of water oxidation based on base metals and a useful reference for those currently involved in the field.

  3. A modified oxidative microcoulometric method for determination of sulphur in hydrocarbons containing large amounts of chlorine.

    Science.gov (United States)

    Cedergren, A

    1977-01-01

    The oxidative coulometric method for trace sulphur determinations has been modified and a procedure is described which includes the elimination of the interferences caused by chlorine whilst retaining a high recovery of sulphur. The liquid hydrocarbon sample is combusted in an excess of oxygen at 1000 K followed by dilution with a proper flow of carbon monoxide at 1300 K. In this way the partial pressure of oxygen is kept small and the interfering chlorine compounds are effectively converted into hydrogen chloride which does not interfere with the coulometric titration. A recovery of sulphur of 96 +/- 1% was found for thiophene in mixtures of chlorobenzene (0-10%) and cyclohexane, thus indicating the absence of significant interference.

  4. REMOVAL OF SELECTED CONGENERS OF POLYCYCLIC AROMATIC HYDROCARBONS FROM THE BOTTOM SEDIMENTS USING CHEMICAL OXIDATION

    Directory of Open Access Journals (Sweden)

    Sabina Książek

    2016-06-01

    Full Text Available Bottom sediments are the part of the aquatic ecosystem, which accumulates most of pollution emitted into environment and flowing into surface waters. This concerns of nutrients, heavy metals and Persistent Organic Pollutants, which include, among others, polycyclic aromatic hydrocarbons (PAHs. PAHs are toxic, carcinogenic mutagenic and teratogenic compounds. The aim of this study was to evaluate the usefulness of chemical oxidation to remove selected PAH contained in bottom sediments. Oxidation of the impurities were carried out using 30% solution of hydrogen peroxide and with the addition of H2O2 with the catalyst FeSO4x7H2O (the Fenton’s method. The efficiency of oxidation was evaluated on the basis of changes in the content of tested impurities, which was determined by gas chromatography coupled with the mass spectrometer (GC-MS after extraction of analytes from bottom sediments. Preliminary studies have shown the efficacy of the use of H2O2 and the Fenton’s method to remove of selected PAHs.

  5. Electrochemical oxidation of the polycyclic aromatic hydrocarbons in polluted concrete of the residential buildings.

    Science.gov (United States)

    Aćimović, Danka D; Karić, Slavko D; Nikolić, Željka M; Brdarić, Tanja P; Tasić, Gvozden S; Marčeta Kaninski, Milica P; Nikolić, Vladimir M

    2017-01-01

    Polycyclic aromatic hydrocarbons (PAH) have been listed by the United States Environmental Protection Agency (US EPA) and by the European Community as priority environmental pollutants. The removal of PAHs from soils, sediments and waste water has attracted attention of scientists and engineers for several decades. Electrochemical oxidation of PAH compounds in water, is receiving increasing attention, due to its convenience and simplicity. In this study we performed electrochemical oxidation of 16 EPA PAHs mixture in 10% NaCl aqueous solution in potentiostatic conditions, at voltage 1 V. Decrease of concentration of some individual PAHs, up to 70% referred to their starting concentration, after 60 min of electrolysis, was confirmed by UPLC/PDA analysis. In further work investigation was extrapolated to in situ removal of PAHs from concrete, as the medium where, to our knowledge, such way of PAH removal has not been investigated before. High concentrations of PAH contamination occurred in the concrete structure of the residential buildings in Belgrade in 2014. Application of DC voltage of 50 V between nickel and stainless steel electrodes packed in the concrete wall, moisturized with the 10% NaCl solution, led to considerable removal of the pollutants by oxidation process throughout the concrete. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Product analysis during the thermo-oxidation of amorphous deuterated hydrocarbon films with NO2

    Directory of Open Access Journals (Sweden)

    D. Alegre

    2015-12-01

    Full Text Available The excellent thermo-oxidation properties of NO2 have been previously reported, pointing to fast carbon co-deposits removal even at temperatures as low as 200 °C. On the other hand, CO, CO2 and water have been found as the main gas products in oxidation by O2, but in NO2 they have not been confirmed. To make a more accurate assessment, the use of in-situ deposited deuterated hydrocarbon films—to be able to distinguish products from ambient, protonated ones—in a fully-baked chamber have been used in the present work, mainly aimed at detecting heavy (deuterated water among the reaction products. Other products from hydrogen isotopes could not be identified, but their production would be much lower than water. The ratio of the total deuterium to carbon products detected is lower by an order of magnitude than the D/C ratio of the film (0.04–0.07 to 0.4, probably associated to the difficulties of measuring water in a vacuum system, and the relatively large quantity of background water found. Furthermore, post-oxidation of CO to CO2 has been found for NO2 at any studied temperature, while for O2 a faster post-oxidation which only occurs at T > 275 °C was found. Finally, the implications of the water production in the use of thermo-oxidation in actual and future nuclear fusion devices are also addressed.

  7. Study of hydrocarbon--shale interaction. Progress report No. 1, July 1, 1976--October 1, 1976

    Energy Technology Data Exchange (ETDEWEB)

    Schettler, P.D. Jr.

    1976-01-01

    Work on Hydrocarbon-Shale Interaction at Juniata College from June 1, 1976 through September 30, 1976 is summarized. Work was accomplished in the following areas: constrictive and geometric effects associated with gas production from shale wells, diffusion constants, hydrocarbon gas analysis, adsorption isotherms and powder x-ray diffraction. A bibliography on adsorption and diffusion in shale was prepared and is included. A detailed description of the procedures used in construction and calibration of the apparatus used for sorption measurements is included. All experimental work was done on cores from Well No. 20403 in Lincoln County, West Virginia.

  8. Research progress in nanographene oxide with tumor imaging and therapy

    Directory of Open Access Journals (Sweden)

    YOU Peihong

    2015-04-01

    Full Text Available Nanographene oxide,one of graphene oxide derivatives and a novel two-dimensional carbon nanomaterial,has become a popular research topic in nanomedicine due to its unique properties such as ultra-high surface-to-volume ratio and great photo-thermal effect.It contains a large amount of reactive chemical groups,including carboxy group,carbonyl group,hydroxyl group and epoxy group,which enable its easy biological and chemical functionalization and excellent biocompatibility.Therefore,it has potential applications in biomedical field.This paper briefly describes the preparation and functionalization of nanographeme oxide,and then mainly focuses on its application studies in the biomedical field,including in vitro and in vivo toxicity tests and advanced research progress of tumor imaging and treatment.

  9. Hydrocarbon oxidation over catalysts prepared by the molecular layer deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Koltsov, S.I.; Smirnov, V.M.; Postnov, V.N.; Postnova, A.M.; Aleskovskii, V.B.

    1980-01-01

    By depositing consecutive uniform monolayers of phosphorus pentoxide and vanadium pentoxide on a large-surface-area (240 sq m/g) silica gel, active and selective catalysts for hydrocarbon oxidation were obtained. Thus, in piperylene oxidation by air at 330/sup 0/-430/sup 0/C and 2000-18,000/hr space velocity, a productive capacity of 220 g/l./hr with 41 mole % each maleic anhydride yield and selectivity was achieved over a SiO/sub 2/-P/sub 2/O/sub 5//P/sub 2/O/sub 5//V/sub 2/O/sub 5/ catalyst (120 sq cm/g surface area), compared with 80 g/l./hr for a P/sub 2/O/sub 5/-V/sub 2/O/sub 5/ catalyst prepared by impregnation. In benzene oxidation, maleic anhydride yields of 52 and 60% and selectivities of 63 and 79% were achieved over SiO/sub 2/-P/sub 2/O/sub 5//V/sub 2/O/sub 5/ and SiO/sub 2/-P/sub 2/O/sub 5//P/sub 2/O/sub 5//P/sub 2/O/sub 5//V/sub 2/O/sub 5/ catalysts, respectively, compared with a 6% yield and very low selectivity over the impregnated P/sub 2/O/sub 5/-V/sub 2/O/sub 5/ catalyst. The molecular-layer catalysts retained their total activity for 100 hr on stream and permitted to reduce the oxidation temperature by 50/sup 0/-70/sup 0/C.

  10. Formation of polycyclic aromatic hydrocarbons and soot in fuel-rich oxidation of methane in a laminar flow reactor

    DEFF Research Database (Denmark)

    Skjøth-Rasmussen, Martin Skov; Glarborg, Peter; Østberg, M.

    2004-01-01

    Conversion of methane to higher hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), and soot was investigated under fuel-rich conditions in a laminar flow reactor. The effects of stoichiometry, dilution, and water vapor addition were studied at temperatures between 1073 and 1823 K. A chemical...... decrease with increasing addition of water vapor. The effect is described qualitatively by the reaction mechanism. The enhanced oxidation of acetylene is attributed to higher levels of hydroxyl radicals, formed from the reaction between the water vapor and hydrogen atoms....

  11. The role of the catalysts with highly dispersed and isolated active sites in the selective oxidation of light hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    WANG Hongxuan; ZHAO Zhen

    2005-01-01

    This review summarizes the role of catalysts with highly dispersed and isolated active sites (active sites: supported atoms f≤0.5 % ) in the selective oxidation of light hydrocarbons, such as methane, ethane and propane, into oxygenatesand the epoxidation of olefins. The plausible structures of the highly dispersed and isolated active species, as well as their effects on the catalytic performances are discussed. The special physico-chemical properties and the functional mechanism of the catalysts with highly dispersed and isolated active sites, as well as the preparation, characterization of the catalysts with highly dispersed and isolated active sites and their applications in other types of reactions of lower hydrocarbons are summarized.

  12. Identification of Methane, Ethane, and Propane Oxidizing Bacteria at Marine Hydrocarbon Seeps by Stable Isotope Probing

    Science.gov (United States)

    Redmond, M.; Ding, H.; Friedrich, M. W.; Valentine, D. L.

    2008-12-01

    Hydrocarbon seeps emit substantial amounts of oil and natural gas into the marine environment, where they can be oxidized by microorganisms in the sediment and water column. Here, we used stable isotope probing of DNA and lipid biomarkers to identify the microorganisms actively consuming 13C-labeled natural gas compounds in seep sediment samples. Surface sediment was collected from the Coal Oil Point seep field (offshore Santa Barbara, California, USA) and incubated under aerobic conditions with 13C labeled methane, ethane, or propane for up to 37 days, with sediment sub-samples taken at 3-4 intermediate time points. DNA was extracted from sediment and separated by CsCl density gradient centrifugation. The microbial community in each fraction was profiled using T-RFLP, and bacterial 16S rRNA gene clone libraries were constructed from un-incubated hydrocarbon seep sediment and selected isotopically 'heavy' (13C) and 'light' (12C) gradient fractions from ethane incubations. All clone libraries were dominated by sequences from members of the family Rhodobacteraceae (>25% of sequences) and a diverse group of Gammaproteobacteria, including sequences related to those of methylotrophs and to those of bacteria known to consume the longer-chain alkanes present in crude oil. After 14 days of incubation, the relative abundance of Rhodobacteraceae was higher in 'heavy' fractions from the 13C-ethane incubation than in 'light' fractions, suggesting incorporation of 13C label. The Rhodobacteraceae are very diverse metabolically, but have often been observed in abundance in oil contaminated seawater. Several members of this group have been shown to oxidize longer chain alkanes (C10 or higher), but none have been previously linked to the consumption of the gaseous alkanes ethane, propane, and butane. For the final time point, 13C content of phospholipid fatty acids (PLFA) were also analyzed, showing substantial incorporation of 13C over 37 days. In the methane incubation

  13. Comparison of automatically generated reaction mechanism for oxidation of simple hydrocarbons in IC engine

    Directory of Open Access Journals (Sweden)

    Muhammad Mansha

    2011-10-01

    Full Text Available In this work, a detailed kinetic reaction mechanism, consisting of 208 reactions and 79 species, has been developed todescribe the oxidation of simple hydrocarbon fuel (natural gas in IC engine. The performance of the proposed mechanismis tested using simulation, tool CHEMKIN 4.1.1, and experimental measurements. The simulation results of the proposedreaction scheme were compared with those of reference mechanisms (GRI v3.0 and Konnov 0.5 version as well as experimentaldata. Based upon simulation results, it can be concluded that the proposed mechanism shows good concordanceswith GR I3.0 mechanism especially in the prediction of temperature, pressure, and major product species (H2O, CO2 profilesat stoichiometric conditions (= 1.0. Although, there are some discrepancies among each predicted profile, the proposeddetailed mechanism is good to describe the oxidation of natural gas in IC engine. The experimental data also showed favorableresults for prediction of major product species (CO2, H2O & CO at various engine operating speeds in idle mode.

  14. 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.).

  15. A predictive tool for selective oxidation of hydrocarbons: optical basicity of catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Moriceau, P.; Lebouteiller, A.; Bordes, E.; Courtine, P. [Universite de Technologie de Compiegne, 60 (France). Dept. de Genie Chimique

    1998-12-31

    Whatever the composition of the catalyst (promoted, supported, multicomponent, etc.) is, it is possible to calculate its electron donor capacity {Lambda}. However, one important question remains: How are the surface and the bulk values of {Lambda} related? Most oxidation catalysts exhibit either a layered structure as V{sub 2}O{sub 5}, and approximately {Lambda}{sub th}{proportional_to}{Lambda}{sub surf}, or a molecular structure as polyoxometallates, and no correction seems to be needed. Work is in progress on that point. Of great importance is also the actual oxidation and coordination states of cations at the stedy state: {Lambda}s have been calculated from the composition determined by XANES and XPS. Finally, the model is able to discriminate between `paraffins` and olefins as reactants. These calibration curves should help to find new catalysts. (orig.)

  16. Adsorption of polycyclic aromatic hydrocarbons by graphene and graphene oxide nanosheets.

    Science.gov (United States)

    Wang, Jun; Chen, Zaiming; Chen, Baoliang

    2014-05-01

    The adsorption of naphthalene, phenanthrene, and pyrene onto graphene (GNS) and graphene oxide (GO) nanosheets was investigated to probe the potential adsorptive sites and molecular mechanisms. The microstructure and morphology of GNS and GO were characterized by elemental analysis, XPS, FTIR, Raman, SEM, and TEM. Graphene displayed high affinity to the polycyclic aromatic hydrocarbons (PAHs), whereas GO adsorption was significantly reduced after oxygen-containing groups were attached to GNS surfaces. An unexpected peak was found in the curve of adsorption coefficients (Kd) with the PAH equilibrium concentrations. The hydrophobic properties and molecular sizes of the PAHs affected the adsorption of G and GO. The high affinities of the PAHs to GNS are dominated by π-π interactions to the flat surface and the sieving effect of the powerful groove regions formed by wrinkles on GNS surfaces. In contrast, the adsorptive sites of GO changed to the carboxyl groups attaching to the edges of GO because the groove regions disappeared and the polar nanosheet surfaces limited the π-π interactions. The TEM and SEM images initially revealed that after loading with PAH, the conformation and aggregation of GNS and GO nanosheets dramatically changed, which explained the observations that the potential adsorption sites of GNS and GO were unusually altered during the adsorption process.

  17. Multi-metallic oxides as catalysts for light alcohols and hydrocarbons from synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Miguel [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico); Diaz, L; Galindo, H de J; Dominguez, J. M; Salmon, Manuel [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    1999-08-01

    A series of Cu-Co-Cr oxides doped with alkaline metals (M), were prepared by the coprecipitation method with metal nitrates (Cu{sup I}I, CO{sup I}I, CR{sup I}II) and (M{sub 2})CO{sub 3} in aqueous solution. The calcined products were used as catalysts for the Fisher-Tropsch synthesis in a stainless-steel fixed bed microreactor. The material was characterized by x-ray diffraction, and the specific surface area, pore size and nitrogen adsorption-desorption properties were also determined. The alkaline metals favored the methanol synthesis and prevent the dehydration reactions whereas the hydrocarbon formation is independent to these metals. [Spanish] Una serie de oxidos Cu-Co-Cr soportados con metales alcalinos (M), fueron preparados por el metodo con nitratos metalicos (Cu{sup I}I, CO{sup I}I, CR{sup I}II) y (M{sub 2})CO{sub 3} en soluciones acuosas. Los productos calcinados fueron usados como catalizadores para la sintesis de Fisher-tropsch en la superficie fija de un microreactor de acero inoxidable. El material fue caracterizado por difraccion de rayos X y el area de superficie especifica, el tamano de poro y propiedades de absorcion-desorcion de nitrogeno fueron determinadas. Los metales alcalinos favorecieron la sintesis de metanol y previnieron las reacciones de deshidratacion, mientras que la formacion de hidrocarburos es independiente de estos metales.

  18. A theoretical study of the interference from chlorine in the oxidative coulometric method for trace determination of sulphur in hydrocarbons.

    Science.gov (United States)

    Cedergren, A

    1975-12-01

    A theoretical investigation has been made of the interference from chlorine in the oxidative coulometric method for trace sulphur determinations. A computer program (SOLGAS), based on the free-energy minimization principle, has been used to predict equilibrium compositions of the products resulting from combustion of a hydrocarbon sample containing sulphur and chlorine. The theoretical possibilities of overcoming the interference from chlorine and maintaining a high recovery of sulphur are described.

  19. Mechanistic implications of the active species involved in the oxidation of hydrocarbons by Iron complexes of pyrazine-2-carboxylic acid

    NARCIS (Netherlands)

    Tanase, Stefania; Marques-Gallego, Patricia; Browne, Wesley R.; Hage, Ronald; Bouwman, Elisabeth; Feringa, Ben L.; Reedijk, Jan

    2008-01-01

    The reactivity towards H2O2 of the complexes [Fe(pca)(2)(py)(2)]center dot py (1) and Na-2{[Fe(pca(3))](2)O}center dot 2H(2)O center dot CH3CN (2) (where pca(-) is pyrazine-2-carboxylate) and their catalytic activity in the oxidation of hydrocarbons is reported. Addition of H2O2 to 1 results in the

  20. GREEN CATALYZED OXIDATION OF HYDROCARBONS IN ALTERNATIVE SOLVENT SYSTEMS GENERATED BY PARIS II DECHEMA; GREEN SOLVENTS FOR CATALYSIS - ENVIRONMENTALLY BENIGN REACTION MEDIA

    Science.gov (United States)

    Green catalyzed oxidation of hydrocarbons in alternative solvent systems generated by PARIS IIThomas M. Becker, Michael A. Gonzalez, Paul F. Harten; Sustainable Technology Division, Office of Research and Development; United States Environmental Protection Agency, 26 West Mar...

  1. Activation parameters as mechanistic probes in the TAML iron(V)-oxo oxidations of hydrocarbons.

    Science.gov (United States)

    Kundu, Soumen; Thompson, Jasper Van Kirk; Shen, Longzhu Q; Mills, Matthew R; Bominaar, Emile L; Ryabov, Alexander D; Collins, Terrence J

    2015-01-19

    The results of low-temperature investigations of the oxidations of 9,10-dihydroanthracene, cumene, ethylbenzene, [D10]ethylbenzene, cyclooctane, and cyclohexane by an iron(V)-oxo TAML complex (2; see Figure 1) are presented, including product identification and determination of the second-order rate constants k2 in the range 233-243 K and the activation parameters (ΔH(≠) and ΔS(≠)). Statistically normalized k2 values (log k2') correlate linearly with the C-H bond dissociation energies DC-H, but ΔH(≠) does not. The point for 9,10-dihydroanthracene for the ΔH(≠) vs. DC-H correlation lies markedly off a common straight line of best fit for all other hydrocarbons, suggesting it proceeds via an alternate mechanism than the rate-limiting C-H bond homolysis promoted by 2. Contribution from an electron-transfer pathway may be substantial for 9,10-dihydroanthracene. Low-temperature kinetic measurements with ethylbenzene and [D10]ethylbenzene reveal a kinetic isotope effect of 26, indicating tunneling. The tunnel effect is drastically reduced at 0 °C and above, although it is an important feature of the reactivity of TAML activators at lower temperatures. The diiron(IV) μ-oxo dimer that is often a common component of the reaction medium involving 2 also oxidizes 9,10-dihydroanthracene, although its reactivity is three orders of magnitude lower than that of 2.

  2. CORONA-INDUCED PHOTOXIDATION OF ALCOHOLS AND HYDROCARBONS OVER TIO2 IN THE ABSENCE OF A UV LIGHT SOURCE - A NOVEL AND ENVIRONMENTALLY FRIENDLY METHOD FOR OXIDATION

    Science.gov (United States)

    Corona-induced photooxidation is a novel oxidation methodology for the efficient oxidation of alcohols and hydrocarbons utilizing the advantage of both the high oxidizing power of ozone formed in the reactor as well as the photooxidation capability of the UV light generated durin...

  3. Effects of methyl group on aromatic hydrocarbons on the nanostructures and oxidative reactivity of combustion-generated soot

    KAUST Repository

    Guerrero Peña, Gerardo D.J.

    2016-07-23

    The substituted and unsubstituted aromatic hydrocarbons, present in transportation fuels such as gasoline and diesel, are thought to be responsible for most of the soot particles produced during their combustion. However, the effects of the substituted alkyl groups on the aromatic hydrocarbons on their sooting tendencies, and on the physical and chemical properties of soot produced from them are not well understood. In this work, the effect of the presence of methyl groups on aromatic hydrocarbons on their sooting propensity, and on the oxidative reactivity, morphology, and chemical composition of soot generated from them in diffusion flames is studied using benzene, toluene, and m-xylene as fuels. Several experimental techniques including high resolution transmission electron microscopy and X-ray diffraction are used to identify the morphological changes in soot, whereas the elemental and thermo-gravimetric analyses, electron energy loss spectroscopy, and Fourier transform infrared spectroscopy are used to study the changes in its chemical properties and reactivity. The activation energies for soot oxidation are calculated at different conversion levels, and a trend in the reactivity of soots from benzene, toluene and m-xylene is reported. It is observed that the sizes of primary particles and graphene-like sheets, and the concentrations of aliphatics and oxygenated groups in soot particles decreased with the addition of methyl group(s) on the aromatic ring. The physicochemical changes in soot are found to support the oxidative reactivity trends. © 2016 The Combustion Institute

  4. Thermodynamic study of characteristics of the converter with separated supply of hydrocarbon fuel for thermo-oxidative and steam reforming

    Science.gov (United States)

    Bassina, I. A.; Malkov, Yu. P.; Molchanov, O. N.; Stepanov, S. G.; Troshchinenko, G. A.; Zasypkin, I. M.

    2014-04-01

    Thermodynamic studies of the converter characteristics were performed to produce hydrogen-containing syngas from hydrocarbon fuel (kerosene) with its separated supply for thermo-oxidative and steam reforming. It is demonstrated that the optimal conditions of the converter performance correlate with the oxidant ratio of α > 0.5 at the heattransfer wall temperature of 1200 K. Hydrogen content in the final syngas reaches 60 % by volume, free carbon (soot) deposition in reforming products is excluded, and there is no need to apply walls water cooling in the converter.

  5. Controlled oxidation of aliphatic CH bonds in metallo-monooxygenases: mechanistic insights derived from studies on deuterated and fluorinated hydrocarbons.

    Science.gov (United States)

    Chen, Yao-Sheng; Luo, Wen-I; Yang, Chung-Ling; Tu, Yi-Jung; Chang, Chun-Wei; Chiang, Chih-Hsiang; Chang, Chi-Yao; Chan, Sunney I; Yu, Steve S-F

    2014-05-01

    The control over the regio- and/or stereo-selective aliphatic CH oxidation by metalloenzymes is of great interest to scientists. Typically, these enzymes invoke host-guest chemistry to sequester the substrates within the protein pockets, exploiting sizes, shapes and specific interactions such as hydrogen-bonding, electrostatic forces and/or van der Waals interactions to control the substrate specificity, regio-specificity and stereo-selectivity. Over the years, we have developed a series of deuterated and fluorinated variants of these hydrocarbon substrates as probes to gain insights into the controlled CH oxidations of hydrocarbons facilitated by these enzymes. In this review, we illustrate the application of these designed probes in the study of three monooxygenases: (i) the particulate methane monooxygenase (pMMO) from Methylococcus capsulatus (Bath), which oxidizes straight-chain C1-C5 alkanes and alkenes to form their corresponding 2-alcohols and epoxides, respectively; (ii) the recombinant alkane hydroxylase (AlkB) from Pseudomonas putida GPo1, which oxidizes the primary CH bonds of C5-C12 linear alkanes; and (iii) the recombinant cytochrome P450 from Bacillus megaterium, which oxidizes C12-C20 fatty acids at the ω-1, ω-2 or ω-3 CH positions.

  6. Environmental analysis of endocrine disrupting effects from hydrocarbon contaminants in the ecosystem. 1997 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-01-01

    'The overall objective of the basic research grant is to characterize the potential of common hydrocarbon contaminants in ecosystems to act as endocrine disruptors. The three major lines of research include (1) a biotechnology based screening system to identify potential hormone mimics and antagonists; (2) an animal screening system to identify biomarkers of endocrine effects. and (3) a literature review to identify compounds at a variety of DOE sites that need to be examined for endocrine disrupting effects. By relating results obtained from this research project to contamination problems at various DOE sites. CBR will provide data and information on endocrine disrupting contaminants to DOE for consideration in risk analyses for determining clean-up levels and priorities needed at the sites.'

  7. Impact of oxidation process on polycyclic aromatic hydrocarbon (PAH) content in bitumen.

    Science.gov (United States)

    Bolliet, Christophe; Juery, Catherine; Thiebaut, Benoit

    2013-01-01

    This study investigated the impact of the oxidation process on the concentration of polycyclic aromatic hydrocarbons (PAH) in blown bitumen and identified some key contributing parameters. The U.S. Environmental Protection Agency's PAH list was used for this study. PAHs are considered a good toxicological marker, and measurement of PAHs in bitumen can be performed easily. The results of PAH content in blown bitumen and the corresponding feedstock was determined from the limit of detection up to 120 mg/kg for 24 samples. Compared to PAH levels in coal tar pitch, PAH levels in bitumen are very low. Measurements were performed by three laboratories using different methods to allow robust conclusions. The results highlight the difficulties in measuring PAHs in bitumen with accuracy for values below 30 mg/kg; therefore the discussion is based on summary statistics by adding concentrations of PAHs with common ring sizes. Incorporation of flux oil in the feed of the blowing bitumen unit tends to increase PAH content in feed stock and in blown bitumen, particularly the 4- to 6-ring PAHs, which are the most carcinogenic as identified by an animal skin painting test. The amount of PAH content from blown bitumen with flux oil can be at least three times higher than the amount in blown bitumen without flux oil, depending on the quality and quantity of the flux oil used. This study shows that the blowing process does not produce PAHs in bitumen. Conversely, it appears to reduce them in the final product. Close to 10 to 30% of PAHs are probably stripped from the liquid phase of bitumen during the blowing operation.

  8. Nitric oxide-assisted atmospheric pressure corona discharge ionization for the analysis of automobile hydrocarbon emission species.

    Science.gov (United States)

    Dearth, M A; Komiski, T J

    1994-12-01

    Nitric oxide reagent gas has been found to improve the sensitivity and robustness of the atmospheric pressure corona discharge ionization (APCDI) process. Sensitivity has been increased by a factor of 20-100, depending on the compound, over APCDI without nitric oxide. The robustness (defined as the sensitivity to matrix interferences) of APCDI in the presence of water has been improved by a factor of 3 over normal APCDI. These improvements are due in part to a modification of the commercial inlet system and ionization chamber that allows the chamber and sample gases to be heated to 100 and 350°C, respectively. Nitric oxide was chosen as the reagent gas because of the variety and selectivity of its interaction with hydrocarbons with differing functional groups. Product ions of nitric oxide ionization and their subsequent tandem mass spectra are presented and discussed for selected alkanes; alkenes, alkylbenzenes, alcohols; aldehydes, and an ether. A tandem mass spectrometry (unique parent ion-daughter ion transition) method was developed to quantify compounds of specific interest in vehicle emissions. The absolute sensitivity for these compounds, under ideal conditions, was determined and ranges from 0.006 ppb for xylene (most sensitive) to 80 ppb for C8 (or larger) normal alkanes. Routine sensitivity for real-world samples was in the single parts per billion range for aromatic and olefinic species. Potential applications include the real-time, on-line monitoring of selected hydrocarbons in automobile exhaust.

  9. Investigating the chemical mechanisms of the functionalization and fragmentation of hydrocarbons in the heterogeneous oxidation by OH using a stochastic kinetics model

    Science.gov (United States)

    Wiegel, A. A.; Wilson, K. R.; Hinsberg, B.; Houle, F. A.

    2014-12-01

    While the heterogeneous oxidation of atmospheric organic aerosols influences their effects on climate, air quality, and visibility, a more detailed understanding of the chemical mechanisms in heterogeneous oxidation is crucial for improving models of their chemical evolution in the atmosphere. Previous experimental work in our lab has shown two general reaction pathways for organic aerosol upon oxidation: functionalization, which adds additional oxygen functional groups to the carbon skeleton, and fragmentation, which leads to C-C bond scission and lower molecular weight oxidized products. Furthermore, these pathways were also found to be dependent on molecular structure, with more branched or oxidized hydrocarbons undergoing more fragmentation than less branched or oxidized hydrocarbons. However, while the mechanisms of hydrocarbon oxidation have been studied extensively in the gas phase, to what extent the gas phase mechanisms of hydrocarbon oxidation can be reliably applied to heterogeneous or bulk oxidation in aerosol remains unclear. To investigate the role of the condensed phase and molecular structure in the mechanism of heterogeneous organic aerosol oxidation, stochastic kinetics models are developed and compared to measurements of the products in the oxidation of hydrocarbons. Within the aerosol bulk, condensed phase rate coefficients and product branching ratios for peroxy reactions lead to different product distributions than those expected from gas phase peroxy reactions due to the presence of the liquid radical cage at the reaction site. As a result, tertiary alcohols and ketones were found to be the predominate products in the oxidation of squalane as observed in experiments. As the aerosol becomes further oxidized, β-scission of alkoxy radicals with neighboring functional groups is the primary fragmentation pathway leading to lower volatility products. In conjunction with this fragmentation mechanism, elimination of CO2 from acyloxy radicals was

  10. Nonmethane hydrocarbons at Pico Mountain, Azores: 1. Oxidation chemistry in the North Atlantic region

    Science.gov (United States)

    Helmig, D.; Tanner, D. M.; Honrath, R. E.; Owen, R. C.; Parrish, D. D.

    2008-10-01

    Measurements of nonmethane hydrocarbons (NMHC) at the Pico Mountain observatory at 2225 m asl on Pico Island, Azores, Portugal, from August 2004 to August 2005 (in part overlapping with the field campaign of the International Consortium on Atmospheric Research on Transport and Transformation study) were used to investigate NMHC sources and seasonal oxidation chemistry in the central North Atlantic region. Levels of anthropogenic NMHC were characteristic of the marine free troposphere. Their concentrations were low compared to continental sites at higher northern latitudes, but higher than data reported from a similarly located Pacific mountain site at Mauna Loa Observatory, Hawaii. These higher NMHC levels are indicative of a greater influence of the adjacent continents on air composition at Pico. Substantially enhanced NMHC concentrations during the summers of 2004 and 2005 were attributed to long-range transport of biomass burning plumes originating from fires in northern Canada, Alaska, and Siberia. This finding exemplifies the continuing impact of biomass burning plumes on atmospheric composition and chemistry many days downwind of these emission sources. Seasonal cycles with lower NMHC concentrations and lower ratios of more reactive to less reactive NMHC during summer reflect the higher degree of photochemical processing occurring during transport. The NMHC concentrations indicate no significant role of chlorine atom oxidation on NMHC. Ozone above 35 ppbv was measured at Pico Mountain throughout all seasons. Enhanced ozone levels were observed in air that had relatively "fresh" photochemical signatures (e.g., ln [propane]/[ethane] > -2.5). During spring-summer air that was more processed ("older" air with ln [propane]/[ethane] < -2.5) on average had lower ozone levels (down to <20 ppbv). This relationship indicates that conditions in the lower free troposphere over the mid-North Atlantic during the spring and summer lead to net photochemical ozone destruction

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

    Institute of Scientific and Technical Information of China (English)

    REN Xiaoling; REN Jizhong; LI Hui; DENG Maicun

    2013-01-01

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

  12. Reduced kinetic mechanism of n-heptane oxidation in modeling polycyclic aromatic hydrocarbon formation in opposed-flow diffusion flames

    Institute of Scientific and Technical Information of China (English)

    Beijing ZHONG; Jun XI

    2008-01-01

    A reduced mechanism, which could couple with the multidimensional computational fluid dynamics code for quantitative description of a reacting flow, was developed for chemical kinetic modeling of polycyclic aro-matic hydrocarbon formation in an opposed-flow dif-fusion flame. The complete kinetic mechanism, which comprises 572 reactions and 108 species, was reduced to a simplified mechanism that includes only 83 reactions and 56 species through sensitivity analysis. The results computed via this reduced mechanism are nearly indistin-guishable from those via the detailed mechanism, which demonstrate that the model based on this reduced mech-anism can properly describe n-heptane oxidation chem-istry and quantitatively predict polycyclic aromatic hydrocarbon (such as benzene, naphthalene, phenan-threne and pyrene) formation in opposed-flow diffusion flames.

  13. Remediation of total petroleum hydrocarbons using combined in-vessel composting ‎and oxidation by activated persulfate

    Directory of Open Access Journals (Sweden)

    A.R. Asgari

    2017-12-01

    Full Text Available This study was investigated the efficiency of activated persulfate and ‎in-vessel composting for removal of total petroleum hydrocarbons. ‎Remediation by activated persulfate with ferrous sulfate as pre-treatment was done at batch system. In the chemical oxidation, various variables including persulfate concentrations (10-3000 mg/g as waste, pH (3-7, ferrous sulfate (0.5-4 mg/g as wasteand temperature (20-60°C were studied. In the biological system, premature compost was added as an amendment. The filter cake to compost ratio were 1:0 (as control and 1:5 to 15 (as dry basis. C: N: P ratio and moisture content were 100:5:1 and 45-60%, respectively. The results showed that acidic pH (pH=3 had high efficiency for the removal of total petroleum hydrocarbons by activated persulfate. Temperature had the significant effect during the persulfate oxidation. When ferrous sulfate was used as an activator for degradation at acidic condition and 60°C, removal efficiency increased to 47.32%. The results of biological process showed that the minimum total petroleum hydrocarbons removal in all reactors was 62 percent. The maximum and minimum removal efficiency was obtained at 1:5 (69.46% and 1:10 (62.42% mixing ratios, respectively. Kinetic study showed that second order kinetic model (R2>0.81 shows the best agreement with the experimental data and the rate of TPH degradation at low mixing ratio (1:3 was faster than high mixing ratio (1:15. Therefore, according to the results, in-vessel composting after pre-treatment by activated persulfate is suggested as an efficient process for degradation of total petroleum hydrocarbons.

  14. OPERATION OF SOLID OXIDE FUEL CELL ANODES WITH PRACTICAL HYDROCARBON FUELS

    Energy Technology Data Exchange (ETDEWEB)

    Scott A. Barnett; Jiang Liu; Yuanbo Lin

    2004-07-30

    This work was carried out to achieve a better understanding of how SOFC anodes work with real fuels. The motivation was to improve the fuel flexibility of SOFC anodes, thereby allowing simplification and cost reduction of SOFC power plants. The work was based on prior results indicating that Ni-YSZ anode-supported SOFCs can be operated directly on methane and natural gas, while SOFCs with novel anode compositions can work with higher hydrocarbons. While these results were promising, more work was clearly needed to establish the feasibility of these direct-hydrocarbon SOFCs. Basic information on hydrocarbon-anode reactions should be broadly useful because reformate fuel gas can contain residual hydrocarbons, especially methane. In the Phase I project, we have studied the reaction mechanisms of various hydrocarbons--including methane, natural gas, and higher hydrocarbons--on two kinds of Ni-containing anodes: conventional Ni-YSZ anodes and a novel ceramic-based anode composition that avoid problems with coking. The effect of sulfur impurities was also studied. The program was aimed both at achieving an understanding of the interactions between real fuels and SOFC anodes, and providing enough information to establish the feasibility of operating SOFC stacks directly on hydrocarbon fuels. A combination of techniques was used to provide insight into the hydrocarbon reactions at these anodes during SOFC operation. Differentially-pumped mass spectrometry was be used for product-gas analysis both with and without cell operation. Impedance spectroscopy was used in order to understand electrochemical rate-limiting steps. Open-circuit voltages measurements under a range of conditions was used to help determine anode electrochemical reactions. Life tests over a wide range of conditions were used to establish the conditions for stable operation of anode-supported SOFC stacks directly on methane. Redox cycling was carried out on ceramic-based anodes. Tests on sulfur tolerance of

  15. Partial Oxidation of Hydrocarbons in a Segmented Bed Using Oxide-based Catalysts and Oxygen-conducting Supports

    Science.gov (United States)

    Smith, Mark W.

    Two objectives for the catalytic reforming of hydrocarbons to produce synthesis gas are investigated herein: (1) the effect of oxygen-conducting supports with partially substituted mixed-metal oxide catalysts, and (2) a segmented bed approach using different catalyst configurations. Excess carbon deposition was the primary cause of catalyst deactivation, and was the focus of the experiments for both objectives. The formation and characterization of deposited carbon was examined after reaction for one of the selected catalysts to determine the quantity and location of the carbon on the catalyst surface leading to deactivation. A nickel-substituted barium hexaaluminate (BNHA), with the formula BaAl 11.6Ni0.4O18.8, and a Rh-substituted lanthanum zirconate pyrochlore (LCZR) with the formula La1.89Ca0.11 Zr1.89Rh0.11, were combined with two different doped ceria supports. These supports were gadolinium-doped ceria (GDC) and zirconium-doped ceria (ZDC). The active catalyst phases were combined with the supports in different ratios using different synthesis techniques. The catalysts were characterized using several different techniques and were tested under partial oxidation (POX) of n-tetradecane (TD), a diesel fuel surrogate. It was found that the presence of GDC and ZDC reduced the formation of carbon for both catalysts; the optimal ratio of catalyst to support was different for the hexaaluminate and the pyrochlore; a loading of 20 wt% of the pyrochlore with ZDC produced the most stable performance in the presence of common fuel contaminants (>50 h); and, the incipient wetness impregnation synthesis method of applying the active catalyst to the support produced more stable product yields than the catalyst prepared by a solid-state mixing technique. Different hexaaluminate and pyrochlore catalysts were used in different configurations in a segmented bed approach. The first strategy was to promote the indirect reforming mechanism by placing a combustion catalyst in the

  16. Oxidative Condensation of Methane — a New Pathway to the Synthesis of Ethane, Ethylene, and Other Hydrocarbons

    Science.gov (United States)

    Minachev, Khabib M.; Usachev, Nikolay Ya; Udut, V. N.; Khodakov, Yu S.

    1988-03-01

    During the last five years, the chemistry of methane has been enriched by the possibility of obtaining C2 and other hydrocarbons as a result of the oxidative condensation of methane in the presence of a series of catalytic systems. The availability of the starting materials (CH4 and O2) leads to extensive prospects for the replacement of the petroleum raw materials by natural gas in single-stage syntheses of valuable compounds and in the first place ethylene. This review gives a systematic account of the results of the selection of effective catalysts and surveys the information leading to the elucidation of the mechanism for the formation of the products of the extensive oxidation and oxidative condensation of methane. The bibliography includes 118 references.

  17. Model catalytic oxidation studies using supported monometallic and heterobimetallic oxides. Progress report, August 1, 1991--January 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Ekerdt, J.G.

    1992-02-03

    This research program is directed toward a more fundamental understanding of the effects of catalyst composition and structure on the catalytic properties of metal oxides. Metal oxide catalysts play an important role in many reactions bearing on the chemical aspects of energy processes. Metal oxides are the catalysts for water-gas shift reactions, methanol and higher alcohol synthesis, isosynthesis, selective catalytic reduction of nitric oxides, and oxidation of hydrocarbons. A key limitation to developing insight into how oxides function in catalytic reactions is in not having precise information of the surface composition under reaction conditions. To address this problem we have prepared oxide systems that can be used to study cation-cation effects and the role of bridging (-O-) and/or terminal (=O) surface oxygen anion ligands in a systematic fashion. Since many oxide catalyst systems involve mixtures of oxides, we selected a model system that would permit us to examine the role of each cation separately and in pairwise combinations. Organometallic molybdenum and tungsten complexes were proposed for use, to prepare model systems consisting of isolated monomeric cations, isolated monometallic dimers and isolated bimetallic dimers supported on silica and alumina. The monometallic and bimetallic dimers were to be used as models of more complex mixed- oxide catalysts. Our current program was to develop the systems and use them in model oxidation reactions.

  18. Manganese-lignin peroxidase hybrid from Bjerkandera adusta oxidizes polycyclic aromatic hydrocarbons more actively in the absence of manganese

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.; Pickard, M. A. [University of Alberta, Dept. of Biological Sciences, Edmonton, AB (Canada); Vazquez-Duhalt, R. [Instituto de Biotecnologia, UNAM, Morelos (Mexico)

    2003-11-01

    Many polycyclic aromatic hydrocarbons (PAHs) are toxic. As such, they are considered priority pollutants and represent a public health risk. Manganese-lignin peroxidase (MnLiP) is a glycoprotein that normally requires manganese(II) for its activity. Enzymatic oxidation of PAHs has been reported with purified preparations of lignin peroxidase (LiP). In this study the oxidation of PAHs was examined in the presence and absence of manganese ions, using whole cells and a purified MnLiP hybrid isoenzyme derived from Bjerkandera adusta, a white rot fungi. The objective was to demonstrate the ability of the MnLiP hybrid enzyme to oxidize PAHs. Results showed a decrease in the rate of oxidation of PAHs in the presence of Mn. A clear correlation was found between the specific activity of MnLiP and the ionization potential (IP) of the PAH substrate. Aromatic substrates were oxidized by the purified enzyme with an IP lower than 7.43 eV; the lower the IP the faster the rate of oxidation. The PAH metabolites of the Mn-independent reaction were identified as the corresponding quinones. PAH oxidation with MnLiP showed a different pH profile according to the presence or absence of Mn: the Mn-dependent oxidation of PAHs showed a lower optimal pH profile than the Mn-independent oxidation. As reported in the case of other white rot fungi the metabolic degradation of PAHs by B. adusta appears to involve both intracellular enzymatic systems such as cytochrome P450, and extracellular oxidative enzymes. 48 refs., 4 tabs., 1 fig.

  19. Enhanced Removal of Biogenic Hydrocarbons in Power Plant Plumes Constrains the Dependence of Atmospheric Hydroxyl Concentrations on Nitrogen Oxides

    Science.gov (United States)

    De Gouw, J. A.; Trainer, M.; Parrish, D. D.; Brown, S. S.; Edwards, P.; Gilman, J.; Graus, M.; Hanisco, T. F.; Kaiser, J.; Keutsch, F. N.; Kim, S. W.; Lerner, B. M.; Neuman, J. A.; Pollack, I. B.; Roberts, J. M.; Ryerson, T. B.; Veres, P. R.; Warneke, C.; Wolfe, G.

    2015-12-01

    Hydroxyl (OH) radicals in the atmosphere provide one of the main chemical mechanisms for the removal of trace gases. OH plays a central role in determining the atmospheric lifetime and radiative forcing of greenhouse gases like methane. OH also plays a major role in the oxidation of organic trace gases, which can lead to formation of secondary pollutants such as ozone and PM2.5. Due to its very short atmospheric lifetime of seconds or less, OH concentrations are extremely variable in space and time, which makes measurements and their interpretation very challenging. Several recent measurements have yielded higher than expected OH concentrations. To explain these would require the existence of unidentified, radical recycling processes, but issues with the measurements themselves are also still being discussed. During the NOAA airborne SENEX study in the Southeast U.S., the biogenic hydrocarbons isoprene and monoterpenes were consistently found to have lower mixing ratios in air masses with enhanced nitrogen oxides from power plants. We attribute this to faster oxidation rates of biogenic hydrocarbons due to increased concentrations of OH in the power plant plumes. Measurements at different downwind distances from the Scherer and Harllee Branch coal-fired power plants near Atlanta are used to constrain the dependence of OH on nitrogen oxides. It is found that OH concentrations were highest at nitrogen dioxide concentrations of 1-2 ppbv and decreased at higher and at lower concentrations. These findings agree with the expected dependence of OH on nitrogen oxide concentrations, but do not appear to be consistent with the reports in the literature that have shown high OH concentrations in regions of the atmosphere with high biogenic emissions and low NOx concentrations that would require unidentified radical recycling processes to be explained.

  20. Neurotrophins, cytokines, oxidative parameters and funcionality in Progressive Muscular Dystrophies

    Directory of Open Access Journals (Sweden)

    CLARISSA M. COMIM

    2015-09-01

    Full Text Available We investigated the levels of brain derived-neurotrophic factor (BDNF, cytokines and oxidative parameters in serum and tried to correlate them with the age and functionality of patients with Progressive Muscle Dystrophies (PMD. The patients were separated into six groups (case and controls pared by age and gender, as follows: Duchenne Muscular Dystrophy (DMD; Steinert Myotonic Dystrophy (SMD; and Limb-girdle Muscular Dystrophy type-2A (LGMD2A. DMD patients (±17.9 years old had a decrease of functionality, an increase in the IL-1β and TNF-α levels and a decrease of IL-10 levels and superoxide dismutase activity in serum. SMD patients (±25.8 years old had a decrease of BDNF and IL-10 levels and superoxide dismutase activity and an increase of IL-1β levels in serum. LGMD2A patients (±27.7 years old had an decrease only in serum levels of IL-10. This research showed the first evidence of BDNF involvement in the SMD patients and a possible unbalance between pro-inflammatory and anti-inflammatory cytokine levels, along with decreased superoxide dismutase activity in serum of DMD and SMD patients.

  1. Oxidation of polycyclic aromatic hydrocarbons using Bacillus subtilis CotA with high laccase activity and copper independence.

    Science.gov (United States)

    Zeng, Jun; Zhu, Qinghe; Wu, Yucheng; Lin, Xiangui

    2016-04-01

    Bacterial laccase CueO from Escherichia coli can oxidize polycyclic aromatic hydrocarbons (PAHs); however, its application in the remediation of PAH-contaminated soil mainly suffers from a low oxidation rate and copper dependence. It was reported that a laccase with a higher redox potential tended to have a higher oxidation rate; thus, the present study investigated the oxidation of PAHs using another bacterial laccase CotA from Bacillus subtilis with a higher redox potential (525 mV) than CueO (440 mV). Recombinant CotA was overexpressed in E. coli and partially purified, exhibiting a higher laccase-specific activity than CueO over a broad pH and temperature range. CotA exhibited moderate thermostability at high temperatures. CotA oxidized PAHs in the absence of exogenous copper. Thereby, secondary heavy metal pollution can be avoided, another advantage of CotA over CueO. Moreover, this study also evaluated some unexplained phenomena in our previous study. It was observed that the oxidation of PAHs with bacterial laccases can be promoted by copper. The partially purified bacterial laccase oxidized only two of the 15 tested PAHs, i.e., anthracene and benzo[a]pyrene, indicating the presence of natural redox mediators in crude cell extracts. Overall, the recombinant CotA oxidizes PAHs with high laccase activity and copper independence, indicating that CotA is a better candidate for the remediation of PAHs than CueO. Besides, the findings here provide a better understanding of the oxidation of PAHs using bacterial laccases. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Experimental study and kinetic analysis of the oxidation of light hydrocarbons mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Rota, R.; Bonini, F.; Morbidelli, M.; Carra, S. [Politecnico di Milano (Italy). Dipt. di Chimica Fisica Applicata

    1996-07-01

    The combustion of various C{sup 1}-C{sub 2} hydrocarbon mixtures has been experimentally investigated in a continuous perfectly stirred reactor, in a temperature range from 1,000 to 1,300 K, and at stoichiometric ratio values between 0.5 and 1.5. The concentration values of several molecular species have been measured by GC analysis. The data obtained have been compared with the predictions of two different detailed kinetic models; both fail to predict the experimental trends in various situations. This leads to the conclusion that experimental data based on mixtures of hydrocarbons must be obtained to validate detailed kinetic mechanisms.

  3. Progress in studies of natural gas conversion in China

    Institute of Scientific and Technical Information of China (English)

    Yu Changchun; Shen Shikong

    2008-01-01

    Progress in natural gas conversion in China is presented in this paper, including processes of natural gas to synthesis gas (syngas), syngas to liquid hydrocarbons, oxygenates synthesis, methanol to olefins (MTO), methane to aromatics and oxidative coupling of methane (OCM).

  4. 信息动态%Research Progress on Electrochemical Oxidation Treatment in Refractory Wastewater

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    This paper describes the research progress of electrochemical oxidation treatment in refractory wastewater at home and abroad, discusses the mechanism of electrochemical oxidation including anodic oxidation technique and cathodic reduction technique in detail, introduces the main influential factors on the degradation efficiency of electrochemical oxidation such as electrode materials, electrochemical reactor, the pH value of the solution, solvent and other factors. The research of electrochemical oxidation mechanism for organic pollutants, the development of electrode materials, the research and development of high efficiency electrolysis reactor,the research on application of specific electrochemical oxidation systems are aspects of the prospect of electrochemical oxidation treatment in refractory wastewater.

  5. Recent Progress in Direct Partial Oxidation of Methane to Methanol

    Institute of Scientific and Technical Information of China (English)

    Qijian Zhang; Dehua He; Qiming Zhu

    2003-01-01

    The direct conversion of methane to methanol has attracted a great deal of attention for nearly a century since it was first found possible in 1902, and it is still a challenging task. This review article describes recent advancements in the direct partial oxidation of methane to methanol. The history of direct oxidation of methane and the difficulties encountered in the partial oxidation of methane to methanol are briefly summarized. Recently reported developments in gas-phase homogeneous oxidation, heterogeneous catalytic oxidation and liquid phase homogeneous catalytic oxidation of methane are reviewed.

  6. Targeting of insect epicuticular lipids by the entomopathogenic fungus Beauveria bassiana: hydrocarbon oxidation within the context of a host-pathogen interaction

    Directory of Open Access Journals (Sweden)

    Nicolas ePedrini

    2013-02-01

    Full Text Available Broad host range entomopathogenic fungi such as Beauveria bassiana attack insect hosts via attachment to cuticular substrata and the production of enzymes for the degradation and penetration of insect cuticle. The outermost epicuticular layer consists of a complex mixture of non-polar lipids including hydrocarbons, fatty acids, and wax esters. Long chain hydrocarbons are major components of the outer waxy layer of diverse insect species, where they serve to protect against desiccation and microbial parasites, and as recognition molecules or as a platform for semiochemicals. Insect pathogenic fungi have evolved mechanisms for overcoming this barrier, likely with sets of lipid degrading enzymes with overlapping substrate specificities.. Alkanes and fatty acids are substrates for a specific subset of fungal cytochrome P450 monooxygenases involved in insect hydrocarbon degradation. These enzymes activate alkanes by terminal oxidation to alcohols, which are further oxidized by alcohol and aldehyde dehydrogenases, whose products can enter β-oxidation pathways. B. bassiana contains at least 83 genes coding for cytochrome P450s (CYP, a subset of which are involved in hydrocarbon oxidation, and several of which represent new CYP subfamilies/families. Expression data indicated differential induction by alkanes and insect lipids and 4 CYP proteins have been partially characterized after heterologous expression in yeast. Gene knockouts revealed a phenotype for only one (cyp52X1 out of 6 genes examined to date. CYP52X1 oxidizes long chain fatty acids and participates in the degradation of specific epicuticular lipid components needed for breaching the insect waxy layer. Examining the hydrocarbon oxidizing CYP repertoire of pathogens involved in insect epicuticle degradation can lead to the characterization of enzymes with novel substrate specificities. Pathogen targeting may also represent an important co-evolutionary process regarding insect cuticular

  7. The hydrothermal synthesis of tetragonal tungsten bronze-based catalysts for the selective oxidation of hydrocarbons.

    Science.gov (United States)

    Botella, Pablo; Solsona, Benjamín; García-González, Ester; González-Calbet, José M; López Nieto, José M

    2007-12-21

    Mixed metal oxides with tetragonal tungsten bronze (TTB) structure, showing high activity and selectivity for the gas phase partial oxidation of olefins, have been prepared by hydrothermal synthesis from Keggin-type heteropolyacids.

  8. Surface chemistry of rare-earth oxide surfaces at ambient conditions: reactions with water and hydrocarbons

    National Research Council Canada - National Science Library

    Elçin Külah; Laurent Marot; Roland Steiner; Andriy Romanyuk; Thomas A Jung; Aneliia Wäckerlin; Ernst Meyer

    2017-01-01

    .... Here we first address physical properties of the RE oxide, nitride and fluoride surfaces modified by exposure to ambient air and then we report a room temperature reaction between PAH and RE oxide...

  9. Sputtering yields and surface chemical modification of tin-doped indium oxide in hydrocarbon-based plasma etching

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hu; Karahashi, Kazuhiro; Hamaguchi, Satoshi, E-mail: hamaguch@ppl.eng.osaka-u.ac.jp [Center for Atomic and Molecular Technologies, Osaka University, Yamadaoka 2-1, Suita 565-0871 (Japan); Fukasawa, Masanaga; Nagahata, Kazunori; Tatsumi, Tetsuya [Device and Material R& D Group, RDS Platform, Sony Corporation, Kanagawa 243-0014 (Japan)

    2015-11-15

    Sputtering yields and surface chemical compositions of tin-doped indium oxide (or indium tin oxide, ITO) by CH{sup +}, CH{sub 3}{sup +}, and inert-gas ion (He{sup +}, Ne{sup +}, and Ar{sup +}) incidence have been obtained experimentally with the use of a mass-selected ion beam system and in-situ x-ray photoelectron spectroscopy. It has been found that etching of ITO is chemically enhanced by energetic incidence of hydrocarbon (CH{sub x}{sup +}) ions. At high incident energy incidence, it appears that carbon of incident ions predominantly reduce indium (In) of ITO and the ITO sputtering yields by CH{sup +} and CH{sub 3}{sup +} ions are found to be essentially equal. At lower incident energy (less than 500 eV or so), however, a hydrogen effect on ITO reduction is more pronounced and the ITO surface is more reduced by CH{sub 3}{sup +} ions than CH{sup +} ions. Although the surface is covered more with metallic In by low-energy incident CH{sub 3}{sup +} ions than CH{sup +} ions and metallic In is in general less resistant against physical sputtering than its oxide, the ITO sputtering yield by incident CH{sub 3}{sup +} ions is found to be lower than that by incident CH{sup +} ions in this energy range. A postulation to account for the relation between the observed sputtering yield and reduction of the ITO surface is also presented. The results presented here offer a better understanding of elementary surface reactions observed in reactive ion etching processes of ITO by hydrocarbon plasmas.

  10. Structure and chemistry of the heteronuclear oxo-cluster [VPO4]•+: a model system for the gas-phase oxidation of small hydrocarbons.

    Science.gov (United States)

    Dietl, Nicolas; Wende, Torsten; Chen, Kai; Jiang, Ling; Schlangen, Maria; Zhang, Xinhao; Asmis, Knut R; Schwarz, Helmut

    2013-03-06

    The heteronuclear oxo-cluster [VPO4](•+) is generated via electrospray ionization and investigated with respect to both its electronic structure as well as its gas-phase reactivity toward small hydrocarbons, thus permitting a comparison to the well-known vanadium-oxide cation [V2O4](•+). As described in previous studies, the latter oxide exhibits no or just minor reactivity toward small hydrocarbons, such as CH4, C2H6, C3H8, n-C4H10, and C2H4, while substitution of one vanadium by a phosphorus atom yields the reactive [VPO4](•+) ion; the latter brings about oxidative dehydrogenation (ODH) of saturated hydrocarbons, e.g., propane and butane as well as oxygen-atom transfer (OAT) to unsaturated hydrocarbons, e.g. ethene, at thermal conditions. Further, the gas-phase structure of [VPO4](•+) is determined by IR photodissociation spectroscopy and compared to that of [V2O4](•+). DFT calculations help to elucidate the reaction mechanism. The results underline the crucial role of phosphorus in terms of C-H bond activation of hydrocarbons by mixed VPO clusters.

  11. Escherichia coli as a potential hydrocarbon conversion microorganism. Oxidation of aliphatic and aromatic compounds by recombinant E. coli in two-liquid phase (aqueous-organic) systems

    NARCIS (Netherlands)

    Favre-Bulle, Olivier

    1992-01-01

    The increased interest in the study of hydrocarbon utilizing microorganisms in recent years has been stimulated by the possibility of using their monooxygenases in the selective oxidation of aliphatic and aromatic compounds. As an example, long chain (>C16) n-alkanes are converted to dicarboxylic

  12. SYNTHESIS, REACTIVITY, AND CATALYTIC BEHAVIOR OF IRON/ZINC-CONTAINING SPECIES INVOLVED IN OXIDATION OF HYDROCARBONS UNDER GIF-TYPE CONDITIONS. (R823377)

    Science.gov (United States)

    The present study explores the nature and reactivity of iron- and zinc-containing speciesgenerated in hydrocarbon-oxidizing Gif(IV)-type solutions Fe catalyst/Zn/O-2 in pyridine/acetic acid(10:1 v/v). The ultimate goal of this investigation is to unravel the role of metal...

  13. CYP63A2, a catalytically versatile fungal P450 monooxygenase capable of oxidizing higher-molecular-weight polycyclic aromatic hydrocarbons, alkylphenols, and alkanes

    Science.gov (United States)

    Cytochrome P450 monooxygenases (P450s) are known to oxidize hydrocarbons albeit with limited substrate specificity across classes of these compounds. Here we report a P450 monooxygenase (CYP63A2) from the model ligninolytic white rot fungus Phanerochaete chrysosporium that was fo...

  14. Photocatalytic degradation of polycyclic aromatic hydrocarbon benzo[a]pyrene by iron oxides and identification of degradation products.

    Science.gov (United States)

    Gupta, Himanshu; Gupta, Bina

    2015-11-01

    Photocatalytic decay profiles of polycyclic aromatic hydrocarbon (PAH) benzo[a]pyrene (B[a]P) have been investigated on various synthesized iron oxides and on soil surfaces under a set of diverse conditions. Samples were analysed using the developed HPLC procedure. Results of the present study demonstrate fastest photodisintegration of B[a]P on goethite followed by haematite, magnetite, akaganeite and maghemite, respectively. The effect of soil pH, irradiation wavelength and iron oxide and oxalic acid dose on the degradation of B[a]P was evaluated. The studies revealed enhancement in photodegradation in the presence of oxalic acid due to the occurrence of fenton like reaction. The results showed faster B[a]P degradation under short wavelength UV radiation. Rate constants in acidic, neutral and alkaline soils under optimum dissipation conditions were 1.11×10(-2), 7.69×10(-3) and 9.97×10(-3) h(-1), respectively. The study indicates that iron oxides along with oxalic acid are effective photocatalyst for the remediation of benzo[a]pyrene contaminated soil surfaces. The degradation products of B[a]P in the soils of different pH in presence of goethite were identified and degradation pathways proposed. Peaks due to toxic metabolites such as diones, diols and epoxides disappear after 120 h in all the three soils.

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

    Institute of Scientific and Technical Information of China (English)

    沈师孔; 李然家; 周吉萍; 余长春

    2003-01-01

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

  16. 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.

  17. Absence of systemic oxidative stress and increased CSF prostaglandin F2α in progressive MS

    DEFF Research Database (Denmark)

    Lam, Magda A; Maghzal, Ghassan J; Khademi, Mohsen

    2016-01-01

    OBJECTIVE: We aimed to investigate the role of oxidative stress in the progression of multiple sclerosis (MS). METHODS: We determined by liquid chromatography-tandem mass spectrometry nonenzymatic (F2-isoprostanes) and enzymatic oxidation products of arachidonic acid (prostaglandin F2α [PGF2α]) i...

  18. Progress Report: Oxidation Stability Studies of Deuterated Esters.

    Science.gov (United States)

    1983-04-26

    esterification goes to completion and hydrolysis does not occur. *i (ii) In the presence of a catalyst (p-toluene sulphonic -" acid ), a fairly low...compounds with the antioxidant. The enhancement in oxidation stability attributable to deuteration (97%) of the acid moiety of the ester appears to be 3...meet these requirements. These esters exhibit very good thermal and oxidative stability at high temperatures (>2000C), excellent viscosity

  19. 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

  20. Sulfur poisoning of hydrocarbon oxidation by palladium. M.S. Thesis

    Science.gov (United States)

    Baumgartner, A. J.

    1975-01-01

    Using a differential bed recycle reactor the oxidation of ethane and diethyl ketone by a Pd catalyst was studied at the 0-30 ppm level in air. In both cases first order kinetics were observed. The ethane oxidation rate was characterized n the Arrhenius form by a pre-exponential of 1.0 x 10 to the 8th power cm/sec and an E sub a of 27 kcal/mole. The diethyl ketone oxidation rate was characterized by a pre-exponential of 5.7 x -1000 cm/sec and E sub a of 14 kcal/mole. Poisoning of ethan oxidation was also investigated by hydrogen sulfide and to a smaller extent by the refrigerants Freon 22 and Gentron 142-B. Poisoning by Gentron 142-B was much more severe than by hydrogen sulfide. Kinetic experiments indicated that only the pre-exponential was changing.

  1. Co-oxidation of carcinogenic polycyclic aromatic hydrocarbons with some biologically active compounds (BAC)

    Energy Technology Data Exchange (ETDEWEB)

    Gubergrits, M.Y.

    1978-09-01

    Oxidation of benzo(a)pyrene (BP) initiated by UV or gamma irradiation was promoted by benz(a)anthracene and 7,12-dimethylbenz(a)anthracene (DMBA) and inhibited by pyrene, dibenz(a,c)anthracene, and asymmetric benz(a)antharacene. The effects of these BAC commonly occurring together with BP in industrial wastes, increased with their concentrations. Phenol and 3-methylcholanthrene strongly promoted BP oxidation when present at low concentrations and inhibited it at high concentrations. Consistent promoting effect was also observed in BP co-oxidation with adipic acid, ..cap alpha..-naphthoflavon, and vitamin E, whereas succinic, azelaic, ferulic, gallic, and chlorogenic acids, rutin, and vitamin C acted as inhibitors. Most saturated dicarboxylic acids studied did not affect BP oxidation at 1:1 acid-BP molar ratio. The kinetics of 7,12-DMBA photooxidation inhibition by some metabolic intermediates, e.g., DMBA endo-peroxide, were also studied.

  2. Study of the Radical Chain Mechanism of Hydrocarbon Oxidation for In Situ Combustion Process

    Directory of Open Access Journals (Sweden)

    Alexandra Ushakova

    2017-01-01

    Full Text Available Despite the abundance of in situ combustion models of oil oxidation, many of the effects are still beyond consideration. For example, until now, initial stages of oxidation were not considered from a position of radical chain process. This is a serious difficulty for the simulation of oil recovery process that involves air injection. To investigate the initial stages of oxidation, the paper considers the sequence of chemical reactions, including intermediate short-living compounds and radicals. We have attempted to correlate the main stages of the reaction with areas of heat release observed in the experiments. The system of differential equations based on the equations of oxidation reactions was solved. Time dependence of peroxides formation and start of heat release is analytically derived for the initial stages. We have considered the inhibition of initial oxidation stages by aromatic oil compounds and have studied the induction time in dependence on temperature. Chain ignition criteria for paraffins and crude oil in presence of core samples were obtained. The calculation results are compared with the stages of oxidation that arise by high-pressure differential scanning calorimetry. According to experimental observations we have determined which reactions are important for the process and which can be omitted or combined into one as insignificant.

  3. In situ vibrational spectroscopic investigation of C4 hydrocarbon selective oxidation over vanadium-phosphorus-oxide catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Zhi -Yang [Iowa State Univ., Ames, IA (United States)

    1999-05-10

    n-Butane selective oxidation over the VPO catalyst to maleic anhydride is the first and only commercialized process of light alkane selective oxidation. The mechanism of this reaction is still not well known despite over twenty years of extensive studies, which can partially be attributed to the extreme difficulties to characterize catalytic reactions real-time under typical reaction conditions. In situ spectroscopic characterization techniques such as Infrared spectroscopy and laser Raman spectroscopy were used in the current mechanistic investigations of n-butane oxidation over VPO catalysts. To identify the reaction intermediates, oxidation of n-butane, 1,3-butadiene and related oxygenates on the VPO catalyst were monitored using FTIR spectroscopy under transient conditions. n-Butane was found to adsorb on the VPO catalyst to form olefinic species, which were further oxidized to unsaturated, noncyclic carbonyl species. The open chain dicarbonyl species then experienced cycloaddition to form maleic anhydride. VPO catalyst phase transformations were investigated using in situ laser Raman spectroscopy. This report contains Chapter 1: General introduction; Chapter 2: Literature review; and Chapter 5: Conclusion and recommendations.

  4. In situ vibrational spectroscopic investigation of C{sub 4} hydrocarbon selective oxidation over vanadium-phosphorus-oxide catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Z.Y.

    1999-05-10

    n-Butane selective oxidation over the VPO catalyst to maleic anhydride is the first and only commercialized process of light alkane selective oxidation. The mechanism of this reaction is still not well known despite over twenty years of extensive studies, which can partially be attributed to the extreme difficulties to characterize catalytic reactions real-time under typical reaction conditions. In situ spectroscopic characterization techniques such as Infrared spectroscopy and laser Raman spectroscopy were used in the current mechanistic investigations of n-butane oxidation over VPO catalysts. To identify the reaction intermediates, oxidation of n-butane, 1,3-butadiene and related oxygenates on the VPO catalyst were monitored using FTIR spectroscopy under transient conditions. n-Butane was found to adsorb on the VPO catalyst to form olefinic species, which were further oxidized to unsaturated, noncyclic carbonyl species. The open chain dicarbonyl species then experienced cycloaddition to form maleic anhydride. VPO catalyst phase transformations were investigated using in situ laser Raman spectroscopy. This report contains Chapter 1: General introduction; Chapter 2: Literature review; and Chapter 5: Conclusion and recommendations.

  5. Progress in Nano-Engineered Anodic Aluminum Oxide Membrane Development

    Directory of Open Access Journals (Sweden)

    Gerrard Eddy Jai Poinern

    2011-02-01

    Full Text Available The anodization of aluminum is an electro-chemical process that changes the surface chemistry of the metal, via oxidation, to produce an anodic oxide layer. During this process a self organized, highly ordered array of cylindrical shaped pores can be produced with controllable pore diameters, periodicity and density distribution. This enables anodic aluminum oxide (AAO membranes to be used as templates in a variety of nanotechnology applications without the need for expensive lithographical techniques. This review article is an overview of the current state of research on AAO membranes and the various applications of nanotechnology that use them in the manufacture of nano-materials and devices or incorporate them into specific applications such as biological/chemical sensors, nano-electronic devices, filter membranes and medical scaffolds for tissue engineering.

  6. Progress on the mechanistic understanding of SO2 oxidation catalysts

    DEFF Research Database (Denmark)

    Lapina, Olga B.; Bal'zhinimaev, B.S.; Boghosian, Soghomon

    1999-01-01

    For almost a century vanadium oxide based catalysts have been the dominant materials in industrial processes for sulfuric acid production. A vast body of information leading to fundamental knowledge on the catalytic process was obtained by Academician [G.K. Boreskov, Catalysis in Sulphuric Acid...

  7. Oxidative stress: Lipid peroxidation products as predictors in disease progression

    Directory of Open Access Journals (Sweden)

    Suranjana Ray Halder

    2014-09-01

    Full Text Available Oxidative stress is implicated in the pathogenesis of numerous disease processes, including diabetes mellitus, atherosclerosis, ischemia reperfusion injury, rheumatoid arthritis, neurodegenerative diseases as well as in the aging process. Chemical modification of amino acids in protein during lipid peroxidation (LPO results in the formation of lipoxidation products, which may serve as indicators of oxidative stress in vivo. The various types of aldehydes such as 4-hydroxynonenal, malondialdehyde, acrolein and others produced during LPO may serve as potent oxidative stress biomarkers. Their activation in different signaling cascades lead to apoptosis, differentiation, proliferation, etc., Increased amount of these aldehydes in aging or with metabolic complications or in other diseases indicate their pathophysiological significance. Thus, LPO products or other oxidative stress biomarkers may open the way for the development of early detection, prevention, and therapeutic strategies for stress associated human diseases. Now-a-days, antioxidant supplementation has become an increasingly popular practice to restore the redox homeostatic condition of the cell. Disease specific, target directed, bioavailable antioxidants may be beneficial for sustenance of the quality-of-life in future days. [J Exp Integr Med 2014; 4(3.000: 151-164

  8. Combustion kinetics of light hydrocarbons in the presence of nitrogen oxide

    Energy Technology Data Exchange (ETDEWEB)

    Rota, R.; Morbidelli, M.; Carra, S. [Politecnico di Milano (Italy). Dipt. di Chimica Fisica Applicata

    1998-11-01

    An experimental analysis of the interactions between different hydrocarbons and NO is reported. All the experiments have been carried out in a perfectly stirred reactor, operated isothermally in the temperature range 1,050--1,250 K, with stoichiometric ratios ranging between 1.0 and 1.3. It has been found that, close to the higher temperature values investigated, the NO conversion as a function of the stoichiometric ratio shows a maximum around 1.15--1.20, both in the case of pure methane and methane-ethane mixtures in the feed. Moreover, the addition of NO significantly enhances the system reactivity at the lower temperatures investigated. The ethane content in the feed plays a different role depending upon the temperature value considered. At the lowest temperatures investigated the larger the amount of ethane, the higher the NO abatement, while at the higher temperatures the methane-ethane mixtures always show a larger NO conversion than that of pure methane. However, when increasing the ethane content in the feed, the NO conversion decreases. Finally, various detailed kinetic models (with particular reference to that developed by Miller and Bowman) have been discussed and used to interpret the experimental results.

  9. Final Technical Report: Tandem and Bimetallic Catalysts for Oxidative Dehydrogenation of Light Hydrocarbon with Renewable Feedstock

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Omar, Mahdi [Purdue Univ., West Lafayette, IN (United States)

    2017-01-06

    An estimated 490 million metric tons of lignocellulosic biomass is available annually from U.S. agriculture and forestry. With continuing concerns over greenhouse gas emission, the development of efficient catalytic processes for conversion of biomass derived compounds is an important area of research. Since carbohydrates and polyols are rich in oxygen, approximately one oxygen atom per carbon, removal of hydroxyl groups via deoxygenation is needed. The necessary hydrogen required for hydrodeoxygenation (HDO) would either come from reforming biomass itself or from steam reforming of natural gas. Both processes contribute to global CO2 emission. The hope is that eventually renewable sources such as wind and solar for hydrogen production will become more viable and economic in the future. In the meantime, unconventional natural gas production in North America has boomed. As a result, light hydrocarbons present an opportunity when coupled with biomass derived oxygenates to generate valuable products from both streams without co-production of carbon dioxide. This concept is the focus of our current funding period. The objective of the project requires coupling two different types of catalysis, HDO and dehydrogenation. Our hypothesis was formulated around our success in establishing oxorhenium catalysts for polyol HDO reactions and known literature precedence for the use of iridium hydrides in alkane dehydrogenation. To examine our hypothesis we set out to investigate the reaction chemistry of binuclear complexes of oxorhenium and iridium hydride.

  10. Progress Toward Quality Assurance Standards for Advanced Hydrocarbon Fuels Based on Thermal Performance Testing and Chemometric Modeling

    Science.gov (United States)

    2015-12-15

    analyses; (2) Identify class distinguishing features, i.e., chemical compounds in the chromatographic data, that contribute to a fuel’s group ...implemented primarily to identify distinguishing chemical compounds that contribute to a fuel’s group assignment. F-ratio analysis was performed using...hydrocarbon-fueled liquid rocket engines, combustion enthalpy is transferred at high rates to thrust chamber surfaces, which are maintained at acceptably

  11. CYP63A2, a catalytically versatile fungal P450 monooxygenase capable of oxidizing higher-molecular-weight polycyclic aromatic hydrocarbons, alkylphenols, and alkanes.

    Science.gov (United States)

    Syed, Khajamohiddin; Porollo, Aleksey; Lam, Ying Wai; Grimmett, Paul E; Yadav, Jagjit S

    2013-04-01

    Cytochrome P450 monooxygenases (P450s) are known to oxidize hydrocarbons, albeit with limited substrate specificity across classes of these compounds. Here we report a P450 monooxygenase (CYP63A2) from the model ligninolytic white rot fungus Phanerochaete chrysosporium that was found to possess a broad oxidizing capability toward structurally diverse hydrocarbons belonging to mutagenic/carcinogenic fused-ring higher-molecular-weight polycyclic aromatic hydrocarbons (HMW-PAHs), endocrine-disrupting long-chain alkylphenols (APs), and crude oil aliphatic hydrocarbon n-alkanes. A homology-based three-dimensional (3D) model revealed the presence of an extraordinarily large active-site cavity in CYP63A2 compared to the mammalian PAH-oxidizing (CYP3A4, CYP1A2, and CYP1B1) and bacterial aliphatic-hydrocarbon-oxidizing (CYP101D and CYP102A1) P450s. This structural feature in conjunction with ligand docking simulations suggested potential versatility of the enzyme. Experimental characterization using recombinantly expressed CYP63A2 revealed its ability to oxidize HMW-PAHs of various ring sizes, including 4 rings (pyrene and fluoranthene), 5 rings [benzo(a)pyrene], and 6 rings [benzo(ghi)perylene], with the highest enzymatic activity being toward the 5-ring PAH followed by the 4-ring and 6-ring PAHs, in that order. Recombinant CYP63A2 activity yielded monohydroxylated PAH metabolites. The enzyme was found to also act as an alkane ω-hydroxylase that oxidized n-alkanes with various chain lengths (C9 to C12 and C15 to C19), as well as alkyl side chains (C3 to C9) in alkylphenols (APs). CYP63A2 showed preferential oxidation of long-chain APs and alkanes. To our knowledge, this is the first P450 identified from any of the biological kingdoms that possesses such broad substrate specificity toward structurally diverse xenobiotics (PAHs, APs, and alkanes), making it a potent enzyme biocatalyst candidate to handle mixed pollution (e.g., crude oil spills).

  12. Chemical kinetic mechanism for the oxidation of paraffinic hydrocarbons needed for primary reference fuels

    Energy Technology Data Exchange (ETDEWEB)

    Westbrook, C.K.; Pitz, W.J.

    1993-03-01

    A detailed chemical kinetic reaction mechanism is described which simulates the oxidation of the primary reference fuels n-heptane and iso-octane. The high temperature subset of these mechanisms is identified, and the extensions to deal with low temperature conditions are also explained. The algorithms used to assign reaction rates to elementary steps in the reaction mechanism are described, and the means of identifying the different chemical species and the relevant reactions are outlined. Finally, we show how interested kinetic modeling researchers can obtain copies of this reaction mechanism.

  13. Graphene oxide bound silica for solid-phase extraction of 14 polycyclic aromatic hydrocarbons in mainstream cigarette smoke.

    Science.gov (United States)

    Shi, Rui; Yan, Lihong; Xu, Tongguang; Liu, Dongye; Zhu, Yongfa; Zhou, Jun

    2015-01-02

    Polycyclic aromatic hydrocarbons (PAHs) were considered as a source of carcinogenicity in mainstream cigarette smoke (MSS). Accurate quantification of these components was necessary for assessing public health risk. In our study, a solid-phase extraction (SPE) method using graphene oxide (GO) bound silica as adsorbent for purification of 14 PAHs in MSS was developed. During SPE process, large matrices interferences of MSS were adsorbed on SPE column. The result of FTIR spectra demonstrated that these matrices interferences were adsorbed on GO mainly through OH and CO groups. The concentrations of PAHs in MSS extract were determined by gas chromatography-mass spectrometry (GC-MS). The limit of detection (LOD) and limit of quantification (LOQ) of the developed method for 14 PAHs ranged from 0.05 to 0.36 ng/cig and 0.17 to 1.19 ng/cig, respectively. The accuracy of the measurement of 14 PAHs was from 73 to 116%. The relative standard deviations of intra- and inter-day analysis were less than 7.8% and 13.9%, respectively. Moreover, the developed method was successfully applied for analysis of real cigarette containing 1R5F reference cigarette and 12 top-selling commercial cigarettes in China.

  14. Methane oxidation in permeable sediments at hydrocarbon seeps in the Santa Barbara Channel, California

    Science.gov (United States)

    Treude, T.; Ziebis, W.

    2010-03-01

    A shallow-water area in the Santa Barbara Channel (California), known collectively as the Coal Oil Point seep field, is one the largest natural submarine oil and gas emission areas in the world. Both gas and oil are seeping constantly through a predominantly sandy seabed into the ocean. This study focused on the methanotrophic activity within the surface sediments (0-15 cm) of the permeable seabed in the so-called Brian Seep area at a water depth ~10 m. Detailed investigations of biogeochemical parameters in the sediment surrounding active gas vents indicated that methane seepage through the permeable seabed induces a convective transport of fluids within the surface sediment layer, which results in a deeper penetration of oxidants (oxygen, sulfate) into the sediment, as well as in a faster removal of potentially inhibiting reduced end products (e.g. hydrogen sulfide). Methanotrophic activity was often found close to the sediment-water interface, indicating the involvement of aerobic bacteria. However, biogeochemical data suggests that the majority of methane is consumed by anaerobic oxidation of methane (AOM) coupled to sulfate reduction below the surface layer (>15 cm), where sulfate is still available in high concentrations. This subsurface maximum of AOM activity in permeable sands is in contrast to known deep-sea seep habitats, where upward fluid advection through more fine-grained sediments leads to an accumulation of AOM activity within the top 10 cm of the sediments, because sulfate is rapidly depleted.

  15. Principles of water oxidation and O2-based hydrocarbon transformation by multinuclear catalytic sites

    Energy Technology Data Exchange (ETDEWEB)

    Musaev, Djamaladdin G [Chemistry, Emory University; Hill, Craig L [Chemistry, Emory University; Morokuma, Keiji [Chemistry, Emory University

    2014-10-28

    Abstract The central thrust of this integrated experimental and computational research program was to obtain an atomistic-level understanding of the structural and dynamic factors underlying the design of catalysts for water oxidation and selective reductant-free O2-based transformations. The focus was on oxidatively robust polyoxometalate (POM) complexes in which a catalytic active site interacts with proximal metal centers in a synergistic manner. Thirty five publications in high-impact journals arose from this grant. I. Developing an oxidatively and hydrolytically stable and fast water oxidation catalyst (WOC), a central need in the production of green fuels using water as a reductant, has proven particularly challenging. During this grant period we have designed and investigated several carbon-free, molecular (homogenous), oxidatively and hydrolytically stable WOCs, including the Rb8K2[{Ru4O4(OH)2(H2O)4}(γ-SiW10O36)2]·25H2O (1) and [Co4(H2O)2(α-PW9O34)2]10- (2). Although complex 1 is fast, oxidatively and hydrolytically stable WOC, Ru is neither abundant nor inexpensive. Therefore, development of a stable and fast carbon-free homogenous WOC, based on earth-abundant elements became our highest priority. In 2010, we reported the first such catalyst, complex 2. This complex is substantially faster than 1 and stable under homogeneous conditions. Recently, we have extended our efforts and reported a V2-analog of the complex 2, i.e. [Co4(H2O)2(α-VW9O34)2]10- (3), which shows an even greater stability and reactivity. We succeeded in: (a) immobilizing catalysts 1 and 2 on the surface of various electrodes, and (b) elucidating the mechanism of O2 formation and release from complex 1, as well as the Mn4O4L6 “cubane” cluster. We have shown that the direct O-O bond formation is the most likely pathway for O2 formation during water oxidation catalyzed by 1. II. Oxo transfer catalysts that contain two proximal and synergistically interacting redox active metal

  16. Principles of water oxidation and O2-based hydrocarbon transformation by multinuclear catalytic sites

    Energy Technology Data Exchange (ETDEWEB)

    Musaev, Djamaladdin G [Chemistry, Emory University; Hill, Craig L [Chemistry, Emory University; Morokuma, Keiji [Chemistry, Emory University

    2014-10-28

    Abstract The central thrust of this integrated experimental and computational research program was to obtain an atomistic-level understanding of the structural and dynamic factors underlying the design of catalysts for water oxidation and selective reductant-free O2-based transformations. The focus was on oxidatively robust polyoxometalate (POM) complexes in which a catalytic active site interacts with proximal metal centers in a synergistic manner. Thirty five publications in high-impact journals arose from this grant. I. Developing an oxidatively and hydrolytically stable and fast water oxidation catalyst (WOC), a central need in the production of green fuels using water as a reductant, has proven particularly challenging. During this grant period we have designed and investigated several carbon-free, molecular (homogenous), oxidatively and hydrolytically stable WOCs, including the Rb8K2[{Ru4O4(OH)2(H2O)4}(γ-SiW10O36)2]·25H2O (1) and [Co4(H2O)2(α-PW9O34)2]10- (2). Although complex 1 is fast, oxidatively and hydrolytically stable WOC, Ru is neither abundant nor inexpensive. Therefore, development of a stable and fast carbon-free homogenous WOC, based on earth-abundant elements became our highest priority. In 2010, we reported the first such catalyst, complex 2. This complex is substantially faster than 1 and stable under homogeneous conditions. Recently, we have extended our efforts and reported a V2-analog of the complex 2, i.e. [Co4(H2O)2(α-VW9O34)2]10- (3), which shows an even greater stability and reactivity. We succeeded in: (a) immobilizing catalysts 1 and 2 on the surface of various electrodes, and (b) elucidating the mechanism of O2 formation and release from complex 1, as well as the Mn4O4L6 “cubane” cluster. We have shown that the direct O-O bond formation is the most likely pathway for O2 formation during water oxidation catalyzed by 1. II. Oxo transfer catalysts that contain two proximal and synergistically interacting redox active metal

  17. Research Progress on Preparation and Application of Graphene Oxide/ Chitosan Biocomposites

    Directory of Open Access Journals (Sweden)

    LYU Sheng-hua

    2016-10-01

    Full Text Available Graphene oxide/chitosan is a new type of biocomposites which was developed in recent years, it possesses the unique mechanical, adsorptive, electrochemical and antibacterial properties. The research progress of graphene oxide/chitosan composites was summarized in this paper. The preparation methods of the biocomposites were introduced briefly. Meanwhile, the application of the biocomposites in the field of high mechanical strength of materials, waste water treatment, electrochemical sensor and biomedical materials were illustrated in details. At last, the low cost and large scale preparation, structure and properties of composite materials and its application in new areas of graphene oxide/chitosan biocomposites were prospected.

  18. Seasonal variability of atmospheric nitrogen oxides and non-methane hydrocarbons at the GEOSummit station, Greenland

    Directory of Open Access Journals (Sweden)

    L. J. Kramer

    2014-05-01

    Full Text Available Measurements of atmospheric NOx (NOx = NO + NO2, peroxyacetyl nitrate (PAN, NOy and non-methane hydrocarbons (NMHC were taken at the GEOSummit Station, Greenland (72.34° N, 38.29° W, 3212 m.a.s.l from July 2008 to July 2010. The data set represents the first year-round concurrent record of these compounds sampled at a high latitude Arctic site in the free troposphere. Here, the study focused on the seasonal variability of these important ozone (O3 precursors in the Arctic free troposphere and the impact from transported anthropogenic and biomass burning emissions. Our analysis shows that PAN is the dominant NOy species in all seasons at Summit, varying from 49% to 78%, however, we find that odd NOy species (odd NOy = NOy − PAN-NOx contribute a large amount to the total NOy speciation with monthly means of up to 95 pmol mol−1 in the winter and ∼40 pmol mol−1 in the summer, and that the level of odd NOy species at Summit during summer is greater than that of NOx. We hypothesize that the source of this odd NOy is most likely alkyl nitrates from transported pollution, and photochemically produced species such as HNO3 and HONO. FLEXPART retroplume analysis and tracers for anthropogenic and biomass burning emissions, were used to identify periods when the site was impacted by polluted air masses. Europe contributed the largest source of anthropogenic emissions during the winter and spring months, with up to 82% of the simulated anthropogenic black carbon originating from this region between December 2009 and March 2010, whereas, North America was the primary source of biomass burning emissions. Polluted air masses were typically aged, with median transport times to the site from the source region of 11 days for anthropogenic events in winter, and 14 days for BB plumes. Overall we find that the transport of polluted air masses to the high altitude Arctic typically resulted in high variability in levels of O3 and O3 precursors. During winter

  19. Recent progress in magnetic iron oxide-semiconductor composite nanomaterials as promising photocatalysts

    Science.gov (United States)

    Wu, Wei; Changzhong Jiang, Affc; Roy, Vellaisamy A. L.

    2014-11-01

    Photocatalytic degradation of toxic organic pollutants is a challenging tasks in ecological and environmental protection. Recent research shows that the magnetic iron oxide-semiconductor composite photocatalytic system can effectively break through the bottleneck of single-component semiconductor oxides with low activity under visible light and the challenging recycling of the photocatalyst from the final products. With high reactivity in visible light, magnetic iron oxide-semiconductors can be exploited as an important magnetic recovery photocatalyst (MRP) with a bright future. On this regard, various composite structures, the charge-transfer mechanism and outstanding properties of magnetic iron oxide-semiconductor composite nanomaterials are sketched. The latest synthesis methods and recent progress in the photocatalytic applications of magnetic iron oxide-semiconductor composite nanomaterials are reviewed. The problems and challenges still need to be resolved and development strategies are discussed.

  20. Methane-Oxidizing Bacteria Shunt Carbon to Microbial Mats at a Marine Hydrocarbon Seep

    Science.gov (United States)

    Paul, Blair G.; Ding, Haibing; Bagby, Sarah C.; Kellermann, Matthias Y.; Redmond, Molly C.; Andersen, Gary L.; Valentine, David L.

    2017-01-01

    The marine subsurface is a reservoir of the greenhouse gas methane. While microorganisms living in water column and seafloor ecosystems are known to be a major sink limiting net methane transport from the marine subsurface to the atmosphere, few studies have assessed the flow of methane-derived carbon through the benthic mat communities that line the seafloor on the continental shelf where methane is emitted. We analyzed the abundance and isotope composition of fatty acids in microbial mats grown in the shallow Coal Oil Point seep field off Santa Barbara, CA, USA, where seep gas is a mixture of methane and CO2. We further used stable isotope probing (SIP) to track methane incorporation into mat biomass. We found evidence that multiple allochthonous substrates supported the rich growth of these mats, with notable contributions from bacterial methanotrophs and sulfur-oxidizers as well as eukaryotic phototrophs. Fatty acids characteristic of methanotrophs were shown to be abundant and 13C-enriched in SIP samples, and DNA-SIP identified members of the methanotrophic family Methylococcaceae as major 13CH4 consumers. Members of Sulfuricurvaceae, Sulfurospirillaceae, and Sulfurovumaceae are implicated in fixation of seep CO2. The mats’ autotrophs support a diverse assemblage of co-occurring bacteria and protozoa, with Methylophaga as key consumers of methane-derived organic matter. This study identifies the taxa contributing to the flow of seep-derived carbon through microbial mat biomass, revealing the bacterial and eukaryotic diversity of these remarkable ecosystems.

  1. Nitric Oxide and Oxygen Air-Contamination Effects on Extinction Limits of Non-Premixed Hydrocarbon-Air Flames for a HIFiRE Scramjet

    Science.gov (United States)

    Pellett, Gerald L.; Dawson, Lucy C.; Vaden, Sarah N.; Wilson, Lloyd G.

    2009-01-01

    Unique nitric oxide (NO) and oxygen air-contamination effects on the extinction Flame Strength (FS) of non-premixed hydrocarbon (HC) vs. air flames are characterized for 7 gaseous HCs, using a new idealized 9.3 mm straight-tube Opposed Jet Burner (OJB) at 1 atm. FS represents a laminar strain-induced extinction limit based on cross-section-average air jet velocity, Uair, that sustains combustion of a counter jet of gaseous fuel just before extinction. Besides ethane, propane, butane, and propylene, the HCs include ethylene, methane, and a 64 mole-% ethylene / 36 % methane mixture, the writer s previously recommended gaseous surrogate fuel for HIFiRE scramjet tests. The HC vs. clean air part of the work is an extension of a May 2008 JANNAF paper that characterized surrogates for the HIFiRE project that should mimic the flameholding of reformed (thermally- or catalytically-cracked) endothermic JP-like fuels. The new FS data for 7 HCs vs. clean air are thus consolidated with the previously validated data, normalized to absolute (local) axial-input strain rates, and co-plotted on a dual kinetically dominated reactivity scale. Excellent agreement with the prior data is obtained for all 7 fuels. Detailed comparisons are also made with recently published (Univ. Va) numerical results for ethylene extinction. A 2009-revised ethylene kinetic model (Univ. Southern Cal) led to predicted limits within approx. 5 % (compared to 45 %, earlier) of this writer s 2008 (and present) ethylene FSs, and also with recent independent data (Univ. Va) obtained on a new OJB system. These +/- 5 % agreements, and a hoped-for "near-identically-performing" reduced kinetics model, would greatly enhance the capability for accurate numerical simulations of surrogate HC flameholding in scramjets. The measured air-contamination effects on normalized FS extinction limits are projected to assess ongoing Arc-Heater-induced "facility test effects" of NO production (e.g., 3 mole-%) and resultant oxygen

  2. Absence of systemic oxidative stress and increased CSF prostaglandin F2α in progressive MS

    DEFF Research Database (Denmark)

    Lam, Magda A.; Maghzal, Ghassan J.; Khademi, Mohsen

    2016-01-01

    Objective: We aimed to investigate the role of oxidative stress in the progression of multiple sclerosis (MS).  Methods: We determined by liquid chromatography-tandem mass spectrometry nonenzymatic (F2-isoprostanes) and enzymatic oxidation products of arachidonic acid (prostaglandin F2α [PGF2α......]) in plasma and CSF of 45 controls (other neurologic disease [OND] with no signs of inflammation) and 62 patients with MS. Oxidation products were correlated with disease severity and validated biomarkers of inflammation (chemokine ligand 13; matrix metalloproteinase-9; osteopontin) and axonal damage...... (neurofilament light protein).  Results: Compared with OND controls, plasma concentrations of F2-isoprostanes and PGF2α were significantly lower in patients with progressive disease, and decreased with increasing disability score (Expanded Disability Status Scale). In contrast, CSF concentrations of PGF2α...

  3. Oxidative stress and antioxidant responses to progressive resistance exercise intensity in trained and untrained males

    Directory of Open Access Journals (Sweden)

    H Çakır-Atabek

    2015-11-01

    Full Text Available The relationship between oxidative stress and some exercise components of resistance exercise (e.g. intensity, exercise volume has not been clearly defined. Additionally, the oxidative stress markers may respond differently in various conditions. This study aims to determine the effects of progressive intensity of resistance exercise (RE on oxidative stress and antioxidants in trained and untrained men, and also to investigate the possible threshold intensity required to evoke oxidative stress. RE trained (N=8 and untrained (N=8 men performed the leg extension RE at progressive intensities standardized for total volume: 1x17 reps at 50% of one-repetition maximum (1RM; 1x14 reps at 60% of 1RM; 1x12 reps at 70% of 1RM; 2x5 reps at 80% of 1RM; and 3x3 reps at 90% of 1RM. Blood samples were drawn before (PRE and immediately after each intensity, and after 30 minutes, 60 minutes and 24 hours following the RE. Lipid-hydroperoxide (LHP significantly increased during the test and then decreased during the recovery in both groups (p0.05. Standardized volume of RE increased oxidative stress responses. Our study suggests that lower intensity (50% is enough to increase LHP, whereas higher intensity (more than 80% is required to evoke protein oxidation.

  4. Women are more susceptible than men to oxidative stress and chromosome damage caused by polycyclic aromatic hydrocarbons exposure.

    Science.gov (United States)

    Guo, Huan; Huang, Kun; Zhang, Xiao; Zhang, Wangzhen; Guan, Lei; Kuang, Dan; Deng, Qifei; Deng, Huaxin; Zhang, Xiaomin; He, Meian; Christiani, David; Wu, Tangchun

    2014-07-01

    Exposure to environmental polycyclic aromatic hydrocarbons (PAHs) has been associated with increased risk of cancer, but evidence for gender differences in this association is limited. The aim of this study was to examine the gender differences in PAHs caused early genotoxic effects such as oxidative stress and chromosome damage, which are potential carcinogenic etiology of PAHs. A total of 478 nonsmoking workers (272 men and 206 women) from a coke oven plant were recruited. We determined 16 environmental PAHs in their workplaces, and measured concentrations of 12 urinary PAH metabolites (OH-PAHs), plasma benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydotetrol-albumin (BPDE-Alb) adducts, urinary 8-hydroxydeoxyguanosine (8-OHdG) and 8-iso-prostaglandin-F2α (8-iso-PGF2α), and micronucleus frequencies in lymphocytes in all subjects. It showed that, women working at the office, adjacent to the coke oven, and on the bottom or side of the coke oven displayed significantly higher levels of urinary 8-OHdG and 8-iso-PGF2α, and lymphocytic micronucleus frequencies compared with men working at above areas, respectively (all P PAHs or plasma BPDE-Alb adducts. A significant interaction existed between gender and BPDE-Alb adducts on increasing micronucleus frequencies (Pinteraction  PAHs or plasma BPDE-Alb adducts, and the above gender differences were more evident in the median- and high-exposure groups (all P PAHs, which may add potential evidence underlying gender differences in PAH exposure-related lung cacinogenesis. Copyright © 2014 Wiley Periodicals, Inc.

  5. Protein Oxidation in Aging: Does It Play a Role in Aging Progression?

    Science.gov (United States)

    Reeg, Sandra

    2015-01-01

    Abstract Significance: A constant accumulation of oxidized proteins takes place during aging. Oxidation of proteins leads to a partial unfolding and, therefore, to aggregation. Protein aggregates impair the activity of cellular proteolytic systems (proteasomes, lysosomes), resulting in further accumulation of oxidized proteins. In addition, the accumulation of highly crosslinked protein aggregates leads to further oxidant formation, damage to macromolecules, and, finally, to apoptotic cell death. Furthermore, protein oxidation seems to play a role in the development of various age-related diseases, for example, neurodegenerative diseases. Recent Advances: The highly oxidized lipofuscin accumulates during aging. Lipofuscin formation might cause impaired lysosomal and proteasomal degradation, metal ion accumulation, increased reactive oxygen species formation, and apoptosis. Critical Issues: It is still unclear to which extent protein oxidation is involved in the progression of aging and in the development of some age-related diseases. Future Directions: An extensive knowledge of the effects of protein oxidation on the aging process and its contribution to the development of age-related diseases could enable further strategies to reduce age-related impairments. Strategies aimed at lowering aggregate formation might be a straightforward intervention to reduce age-related malfunctions of organs. Antioxid. Redox Signal. 23, 239–255. PMID:25178482

  6. Deep catalytic oxidation of heavy hydrocarbons on Pt/Al{sub 2}O{sub 3} catalysts; Oxydation catalytique totale des hydrocarbures lourds sur Pt/Al{sub 2}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, F.

    1998-12-09

    Deep oxidation by air on Pt supported on alumina of a large number of heavy hydrocarbons representative of those found in a real Diesel car exhaust has been studied. Light-off temperatures between 140 and 320 deg. C on 1%Pt/alumina (80% metal dispersion) have been found. Results show that not only the physical state around the conversion area but also the chemical nature of the hydrocarbon plays an important role. Heavy hydrocarbons deep oxidation behaviour has been classified as a function of their chemical category (alkane, alkene, aromatics etc..). Oxidation of binary mixtures of hydrocarbons has shown strong inhibition effects on n-alkane or CO oxidation by polycyclic compounds like 1-methyl-naphthalene. In some cases, by-product compounds in the gas effluent (other than CO{sub 2} and H{sub 2}O) have been identified by mass-spectrometry leading to oxidation mechanism proposals for different hydrocarbons. Catalyst nature (metal dispersion, content) influence has also been studied. It is shown that turn-over activity is favoured by the increase of the metal bulk size. Acidity influence of the carrier has shown only very little influence on n-alkane or di-aromatic compound oxidation. (author)

  7. Toward Understanding the Role of Aryl Hydrocarbon Receptor in the Immune System: Current Progress and Future Trends

    Directory of Open Access Journals (Sweden)

    Hamza Hanieh

    2014-01-01

    Full Text Available The immune system is regulated by distinct signaling pathways that control the development and function of the immune cells. Accumulating evidence suggest that ligation of aryl hydrocarbon receptor (Ahr, an environmentally responsive transcription factor, results in multiple cross talks that are capable of modulating these pathways and their downstream responsive genes. Most of the immune cells respond to such modulation, and many inflammatory response-related genes contain multiple xenobiotic-responsive elements (XREs boxes upstream. Active research efforts have investigated the physiological role of Ahr in inflammation and autoimmunity using different animal models. Recently formed paradigm has shown that activation of Ahr by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD or 3,3′-diindolylmethane (DIM prompts the differentiation of CD4+Foxp3+ regulatory T cells (Tregs and inhibits T helper (Th-17 suggesting that Ahr is an innovative therapeutic strategy for autoimmune inflammation. These promising findings generate a basis for future clinical practices in humans. This review addresses the current knowledge on the role of Ahr in different immune cell compartments, with a particular focus on inflammation and autoimmunity.

  8. Engineered antibodies for monitoring of polynuclear aromatic hydrocarbons. Annual progress report, October 1, 1996--September 30, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Karu, A.E. [Univ. of California, Berkeley, CA (US); Roberts, V.A. [Scripps Research Inst., La Jolla, CA (US); Li, Q.X. [Univ. of Hawaii, Honolulu, HI (US)

    1997-01-01

    'The objective of this multidisciplinary project is to use molecular biological techniques to derive a set of antibodies with useful affinities and selectivities for recovery and detection of polynuclear aromatic hydrocarbons (PAHs) in environmental and biological samples. The long-term goal is to develop immunodetection methods that will be useful in biomarker research and regulatory monitoring of PAHs. APPROACH The aims and approaches remain the same as in the original proposal. My laboratory cloned and characterized two PAL-I-specific recombinant Fab antibodies (rFabs). The authors are deriving new affinities and specificities for PAHs by mutagenesis of these rFabs, and by selection of new rFabs from combinatorial phage display libraries. Dr. Qing Li''s group designed and synthesized PAH haptens that were essential for my laboratory''s work. Dr. Victoria Roberts''s group developed molecular models that suggested the mechanism of PAH binding and predicted mutations to alter it. Dr. Li''s laboratory is using the recombinant antibodies they produce to develop immunoaffinity and immunoassay methods to quantify PAHs in environmental samples.'

  9. Direct hydrocarbon fuel cells

    Science.gov (United States)

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

    2010-05-04

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

  10. 红球菌在石油烃类物质降解中的作用%Progress in Petroleum Hydrocarbon Biodegradation by Rhodococcus

    Institute of Scientific and Technical Information of China (English)

    张光军; 方萍

    2013-01-01

    红球菌属是有机污染物降解的重要微生物之一.由于红球菌能够适应各种各样的底物环境,具有极强的有机溶剂耐受性和很宽的降解谱,同时它们还能通过产生表面活性剂和改变细胞表面组成结构来提升自身对于疏水性环境的适应能力,因此,红球菌在石油污染物降解及石油污染的生物修复等领域有着极其重要的应用价值.文章基于近年来在红球菌降解石油烃方面的研究进展,从红球菌适应疏水性环境的机制、石油烃中烷烃、环烷烃、芳香烃的降解途径等几个方面进行综述,同时对今后研究的方向进行了展望.%Rhodococcus as a sort of microbial for organic compounds biodegradation with strong organic solvent tolerance and wide degradation spectrum, can adapt to various substrates, as well as promoting its adaption to hydrophobic surroundings by producing surfactants or changing cell surface composition and structure.Due to the characteristics, Rhodococcus acts extremely important roles in oil pollution bioremediation.Based on progress in petroleum hydrocarbon biodegradation by Rhodococcus, the adaption mechanism to hydrophobic environment, the degradation process of alkane, cycloparafin hydrocarbon and aromatics were reviewed.The prospect related to Rhodococcus in bioremediation in future was also proposed.

  11. Effect of hydrocarbons and nitrogen oxides on ozone formation in smog chambers exposed to solar irradiance of Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval F, J; Marroquin de la R, O; Jaimes L, J. L; Zuniga L, V. A; Gonzalez O, E; Guzman Lopez-Figueroa, F [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico)

    2001-01-01

    Outdoor smog chambers experiments were performed on air to determine the answer of maximum ozone levels, to changes in the initial hydrocarbons, HC, and nitrogen oxide NO{sub x}. These captive-air experiments under natural irradiation were carried out. Typically, eight chambers were filled with Mexico city air in the morning. In some of those chambers, the initial HC and/or Nox concentrations were varied by {+-}25% to {+-}50% by adding various combinations of a mixture of HC, clean air, or NO{sub x} (perturbed chambers). The O{sub 3} and NO{sub x} concentration in each chamber was monitored throughout the day to determine O{sub 3} (max). The initial HC and NO{sub x} concentration effects were determined by comparing the maximum ozone concentrations measured in the perturbed and unperturbed chambers. Ozone isopleths were constructed from the empirical model obtained of measurements of the eight chambers and plotted in a graph whose axe were the initial HC and NO{sub x} values. For the average initial conditions that were measured in Mexico City, it was found that the most efficient strategy to reduce the maximum concentration of O{sub 3} is the one that reduces NO{sub x}. [Spanish] Se realizaron experimentos de camaras de esmog con el aire de la ciudad de Mexico para determinar las respuestas de los niveles maximos de ozono a los cambios en las concentraciones iniciales de hidrocarburos, HC y oxido de nitrogeno, NO{sub x}. Por lo general, se llenaron 8 bolsas con aire matutino de la Ciudad de Mexico. En algunas camaras, las concentraciones iniciales fueron cambiadas de 25% a 50%, anadiendo varias concentraciones de una mezcla de HC, aire limpio y/o NO{sub x}. La concentracion de O{sub 3} y NO{sub x}, en cada camara, fueron monitoreadas a lo largo del dia para determinar el maximo de O{sub 3}. El efecto de los HC y el NO{sub x} fue determinado por comparacion del maximo de ozono formado en las camaras, que fueron perturbadas por adicion o reduccion de HC y/o Nox

  12. 气相光催化氧化降解卤代烃的研究%Gas-Phase Photocatalytic Oxidation of Halogenated Hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    李功虎; 安纬珠

    2000-01-01

      本文介绍了气相光催化作用的基本原理,从光催化剂的改性技术、反应动力学和反应机理三个方面综述了近年来气相光催化氧化降解卤代烃的研究。%  This paper introduced the photocatalyzing principle of semiconductor in gas phase,and summarized the recent studies on the gas-phase photocatalytic oxidation of halogenated hydrocarbons,including modification of semiconductor,reaction kinetics and the degradation mechanism of TCE.

  13. Role of oxidative stress and autoimmunity in onset and progression of vitiligo.

    Science.gov (United States)

    Laddha, Naresh C; Dwivedi, Mitesh; Mansuri, Mohmmad Shoab; Singh, Mala; Gani, Amina R; Yeola, Asmita P; Panchal, Vipul N; Khan, Fazal; Dave, Darshana J; Patel, Ananddeep; Madhavan, Shajil E; Gupta, Richa; Marfatia, Zarna; Marfatia, Yogesh S; Begum, Rasheedunnisa

    2014-05-01

    Vitiligo is an acquired depigmentation disorder characterized by the loss of functional melanocytes from the epidermis. Two major theories of vitiligo pathogenesis include autoimmunity and oxidative stress-mediated toxicity in melanocytes. The present study aimed to evaluate both the hypotheses in vitiligo patients and to investigate their role in the disease onset and progression. Antimelanocyte antibody levels and lipid peroxidation (LPO) levels were evaluated in 427 patients and 440 controls; antithyroid peroxidase (TPO) antibody levels were estimated in 102 patients and 72 controls. Patients showed a significant increase in LPO and antimelanocyte antibody levels compared to controls. Antimelanocyte antibody and LPO levels were higher in active vitiligo compared to stable. Only 9.8% of patients showed the presence of anti-TPO antibodies in their circulation. Oxidative stress may be the initial triggering event to precipitate vitiligo in Gujarat population, which is exacerbated by contributing autoimmune factors together with oxidative stress.

  14. High amylose resistant starch diet ameliorates oxidative stress, inflammation, and progression of chronic kidney disease.

    Directory of Open Access Journals (Sweden)

    Nosratola D Vaziri

    Full Text Available Inflammation is a major mediator of CKD progression and is partly driven by altered gut microbiome and intestinal barrier disruption, events which are caused by: urea influx in the intestine resulting in dominance of urease-possessing bacteria; disruption of epithelial barrier by urea-derived ammonia leading to endotoxemia and bacterial translocation; and restriction of potassium-rich fruits and vegetables which are common sources of fermentable fiber. Restriction of these foods leads to depletion of bacteria that convert indigestible carbohydrates to short chain fatty acids which are important nutrients for colonocytes and regulatory T lymphocytes. We hypothesized that a high resistant starch diet attenuates CKD progression. Male Sprague Dawley rats were fed a chow containing 0.7% adenine for 2 weeks to induce CKD. Rats were then fed diets supplemented with amylopectin (low-fiber control or high fermentable fiber (amylose maize resistant starch, HAM-RS2 for 3 weeks. CKD rats consuming low fiber diet exhibited reduced creatinine clearance, interstitial fibrosis, inflammation, tubular damage, activation of NFkB, upregulation of pro-inflammatory, pro-oxidant, and pro-fibrotic molecules; impaired Nrf2 activity, down-regulation of antioxidant enzymes, and disruption of colonic epithelial tight junction. The high resistant starch diet significantly attenuated these abnormalities. Thus high resistant starch diet retards CKD progression and attenuates oxidative stress and inflammation in rats. Future studies are needed to explore the impact of HAM-RS2 in CKD patients.

  15. Disease Progression Mediated by Egr-1 Associated Signaling in Response to Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Elisabeth Deindl

    2012-10-01

    Full Text Available When cellular reducing enzymes fail to shield the cell from increased amounts of reactive oxygen species (ROS, oxidative stress arises. The redox state is misbalanced, DNA and proteins are damaged and cellular transcription networks are activated. This condition can lead to the initiation and/or to the progression of atherosclerosis, tumors or pulmonary hypertension; diseases that are decisively furthered by the presence of oxidizing agents. Redox sensitive genes, like the zinc finger transcription factor early growth response 1 (Egr-1, play a pivotal role in the pathophysiology of these diseases. Apart from inducing apoptosis, signaling partners like the MEK/ERK pathway or the protein kinase C (PKC can activate salvage programs such as cell proliferation that do not ameliorate, but rather worsen their outcome. Here, we review the currently available data on Egr-1 related signal transduction cascades in response to oxidative stress in the progression of epidemiologically significant diseases. Knowing the molecular pathways behind the pathology will greatly enhance our ability to identify possible targets for the development of new therapeutic strategies.

  16. Disease progression and oxidative stress are associated with higher serum ferritin levels in patients with multiple sclerosis.

    Science.gov (United States)

    Ferreira, Katerine Panichi Zanin; Oliveira, Sayonara R; Kallaur, Ana Paula; Kaimen-Maciel, Damacio R; Lozovoy, Marcell Alysson B; de Almeida, Elaine Regina Delicato; Morimoto, Helena Kaminami; Mezzaroba, Leda; Dichi, Isaias; Reiche, Edna Maria Vissoci; Simão, Andréa Name Colado

    2017-02-15

    Hyperferritinemia and oxidative stress have been implicated in the pathogenesis of multiple sclerosis (MS). The aim of the present study was to evaluate the serum levels of ferritin and to verify their association with oxidative stress markers and MS progression. This study included 164 MS patients, which were divided in two groups according to their levels of ferritin (cut off 125.6μg/L). Oxidative stress was evaluated by tert-butyl hydroperoxide-initiated chemiluminescence (CL-LOOH), advanced oxidation protein products (AOPP), carbonyl protein, nitric oxide metabolites (NOx), sulfhydryl groups of protein and total radical-trapping antioxidant parameter (TRAP). MS patients with elevated levels of ferritin showed higher disease progression (p=0.030), AOPP (p=0.001), and lower plasma NOx levels (p=0.031) and TRAP (p=0.006) than MS patients with lower ferritin levels. The multivariate binary logistic regression analysis showed that increased AOPP and progression of disease were significantly and positively associated with increase of ferritin. The combination of serum ferritin levels and oxidative stress markers were responsible for 13,9% in the disease progression. In conclusion, our results suggest that ferritin could aggravate oxidative stress in patients with MS and contribute to progression of disease. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. A fungal P450 (CYP5136A3 capable of oxidizing polycyclic aromatic hydrocarbons and endocrine disrupting alkylphenols: role of Trp(129 and Leu(324.

    Directory of Open Access Journals (Sweden)

    Khajamohiddin Syed

    Full Text Available The model white rot fungus Phanerochaete chrysosporium, which is known for its versatile pollutant-biodegradation ability, possesses an extraordinarily large repertoire of P450 monooxygenases in its genome. However, the majority of these P450s have hitherto unknown function. Our initial studies using a genome-wide gene induction strategy revealed multiple P450s responsive to individual classes of xenobiotics. Here we report functional characterization of a cytochrome P450 monooxygenase, CYP5136A3 that showed common responsiveness and catalytic versatility towards endocrine-disrupting alkylphenols (APs and mutagenic/carcinogenic polycyclic aromatic hydrocarbons (PAHs. Using recombinant CYP5136A3, we demonstrated its oxidation activity towards APs with varying alkyl side-chain length (C3-C9, in addition to PAHs (3-4 ring size. AP oxidation involves hydroxylation at the terminal carbon of the alkyl side-chain (ω-oxidation. Structure-activity analysis based on a 3D model indicated a potential role of Trp(129 and Leu(324 in the oxidation mechanism of CYP5136A3. Replacing Trp(129 with Leu (W129L and Phe (W129F significantly diminished oxidation of both PAHs and APs. The W129L mutation caused greater reduction in phenanthrene oxidation (80% as compared to W129F which caused greater reduction in pyrene oxidation (88%. Almost complete loss of oxidation of C3-C8 APs (83-90% was observed for the W129L mutation as compared to W129F (28-41%. However, the two mutations showed a comparable loss (60-67% in C9-AP oxidation. Replacement of Leu(324 with Gly (L324G caused 42% and 54% decrease in oxidation activity towards phenanthrene and pyrene, respectively. This mutation also caused loss of activity towards C3-C8 APs (20-58%, and complete loss of activity toward nonylphenol (C9-AP. Collectively, the results suggest that Trp(129 and Leu(324 are critical in substrate recognition and/or regio-selective oxidation of PAHs and APs. To our knowledge, this is the first

  18. Enhanced susceptibility of low-density lipoproteins to oxidation in coronary bypass patients with progression of atherosclerosis

    NARCIS (Netherlands)

    Rijke, Y.B. de; Verwey, H.F.; Vogelezang, C.J.M.; Velde, E.A. van der; Princen, H.M.G.; Laarse, A. van der; Bruschke, A.V.G.; Berkel, T.J.C. van

    1995-01-01

    Oxidation of low-density lipoprotein (LDL) may play a causal role in atherosclerosis. In this study we analyzed whether the severity of progression of coronary atherosclerosis is related to the susceptibility of LDL to oxidative modification. On the basis of repeated coronary angiography, 28 coronar

  19. Enhanced susceptibility of low-density lipoproteins to oxidation in coronary bypass patients with progression of atherosclerosis

    NARCIS (Netherlands)

    Rijke, Y.B. de; Verwey, H.F.; Vogelezang, C.J.M.; Velde, E.A. van der; Princen, H.M.G.; Laarse, A. van der; Bruschke, A.V.G.; Berkel, T.J.C. van

    1995-01-01

    Oxidation of low-density lipoprotein (LDL) may play a causal role in atherosclerosis. In this study we analyzed whether the severity of progression of coronary atherosclerosis is related to the susceptibility of LDL to oxidative modification. On the basis of repeated coronary angiography, 28 coronar

  20. Enhanced susceptibility of low-density lipoproteins to oxidation in coronary bypass patients with progression of atherosclerosis

    NARCIS (Netherlands)

    Rijke, Y.B. de; Verwey, H.F.; Vogelezang, C.J.M.; Velde, E.A. van der; Princen, H.M.G.; Laarse, A. van der; Bruschke, A.V.G.; Berkel, T.J.C. van

    1995-01-01

    Oxidation of low-density lipoprotein (LDL) may play a causal role in atherosclerosis. In this study we analyzed whether the severity of progression of coronary atherosclerosis is related to the susceptibility of LDL to oxidative modification. On the basis of repeated coronary angiography, 28

  1. Recent progress and perspectives in the photocatalytic CO2 reduction of Ti-oxide-based nanomaterials

    Science.gov (United States)

    Sohn, Youngku; Huang, Weixin; Taghipour, Fariborz

    2017-02-01

    The conversion of CO2 with H2O to valuable chemicals and fuels is a new solution to current environmental and energy problems, and the high energy barrier of these reactions can be overcome by the input of solar and electrical energy. However, the reduction efficiencies and selectivities of these reactions are insufficient for practical use, and significant effort and strategy are required to overcome the many obstacles preventing the large-scale application of photocatalytic CO2 reduction. This article reviews recent progress in CO2 reduction using titanium oxide-based materials and various strategic factors for increasing photocatalytic efficiency. This article also highlights non-titanium-oxide catalysts, the photoelectrocatalytic reduction of CO2, and other recent review articles concerning the recycling of CO2 to value-added carbon compounds.

  2. PAHs污染土壤生物修复强化技术研究进展%Research progress in enhanced bioremediation of polycyclic aromatic hydrocarbons contaminated soil

    Institute of Scientific and Technical Information of China (English)

    王洪; 李海波; 孙铁珩; 胡筱敏

    2011-01-01

    为提高生物修复多环芳烃(PAHs)污染土壤的效率,从PAHs生物修复的原理和强化措施出发,综述了PAHs污染土壤生物修复的物理化学强化技术和生物强化技术,分析了各种技术的原理与适用条件,提出了植物强化微生物修复是PAHs污染土壤生物修复的重要发展方向.在进行强化修复的过程中,要注重现场应用和安全性评价.%This paper is aimed to present a general review on the enhanced measures to the bioremediation of polycyclic aromatic hydrocarbons contaminated soil. Polycyclic aromatic hydrocarbons (PAHs) are well known as a group of persistent organic pollutants (POPs) and more than 90% of PAHs present in the soil, which are toxic to the environment and pose as a hazard in food chain to human health.Bioremediation technology is the primary method to treat the PAHs contaminated soil and the enhanced measures of bioremediation treatment are essential to improve the degradation rate and adapt to the needs of field application. Referring to the reported literature at home and abroad in recent years, this paper comes out with a detail introduction and discussion on the principles and application of physicalchemical and biological based enhancement. The enhanced measures of physical-chemical included the application of surfactants, nutrient addition and co-metabolic substrate addition as well as the electron acceptors addition and utilization of chemical oxidants. The enhanced measures of bioremediation included the addition of highly efficient PAH-degrading bacteria and immobilization of bacteria, utilization of mycorrhizal fungi and application of bio-surfactants. The combined remediation of phytoremediation and microorganism on the PAHs conlaminated soil is an important direction of development and field application technology. At the same time, safety evaluation in the process of enhanced bioremediation is necessary in order to avoid new pollution and other security risks to

  3. The Potential Role of Nitric Oxide in Halting Cancer Progression Through Chemoprevention

    Science.gov (United States)

    Vahora, Huzefa; Khan, Munawwar Ali; Alalami, Usama; Hussain, Arif

    2016-01-01

    Nitric oxide (NO) in general plays a beneficial physiological role as a vasorelaxant and the role of NO is decided by its concentration present in physiological environments. NO either facilitates cancer-promoting characters or act as an anti-cancer agent. The dilemma in this regard still remains unanswered. This review summarizes the recent information on NO and its role in carcinogenesis and tumor progression, as well as dietary chemopreventive agents which have NO-modulating properties with safe cytotoxic profile. Understanding the molecular mechanisms and cross-talk modulating NO effect by these chemopreventive agents can allow us to develop better therapeutic strategies for cancer treatment. PMID:27051643

  4. Progress in the development of semiconducting metal oxide gas sensors: a review

    Science.gov (United States)

    Moseley, Patrick T.

    2017-08-01

    Since the first suggestion, during the 1950s, that high-surface-area metal oxides could be used as conductometric gas sensors enormous efforts have been made to enhance both the selectivity and the sensitivity of such devices, and to reduce their operational power requirements. This development has involved the exploration of response mechanisms, the selection of the most appropriate oxide compositions, the fabrication of two-phase ‘hetero-structures’, the addition of metallic catalyst particles and the optimisation of the manner in which the materials are presented to the gas—the structure and the nanostructure of the sensing elements. Far more of the scientific literature has been devoted to seeking such improvements in metal oxide gas sensors than has been directed at all other solid-state gas sensors together. Recent progress in the research and development of metal oxide gas sensor technology is surveyed in this invited review. The advances that have been made are quite spectacular and the results of individual pieces of work are drawn together here so that trends can be seen. Emerging features include: the significance of n-type/p-type switching, the enhancement of sensing performance of materials through the incorporation of secondary components and the advantages of interrogating sensors with alternating current rather than direct current.

  5. Recent progress in tungsten oxides based memristors and their neuromorphological applications

    Science.gov (United States)

    Qu, Bo; Younis, Adnan; Chu, Dewei

    2016-09-01

    The advance in conventional silicon based semiconductor industry is now becoming indeterminacy as it still along the road of Moore's Law and concomitant problems associated with it are the emergence of a number of practical issues such as short channel effect. In terms of memory applications, it is generally believed that transistors based memory devices will approach to their scaling limits up to 2018. Therefore, one of the most prominent challenges today in semiconductor industry is the need of a new memory technology which is able to combine the best characterises of current devices. The resistive switching memories which are regarded as "memristors" thus gain great attentions thanks to their specific nonlinear electrical properties. More importantly, their behaviour resembles with the transmission characteristic of synapse in biology. Therefore, the research of synapses biomimetic devices based on memristor will certainly bring a great research prospect in studying synapse emulation as well as building artificial neural networks. Tungsten oxides (WO x ) exhibits many essential characteristics as a great candidate for memristive devices including: accredited endurance (over 105 cycles), stoichiometric flexibility, complimentary metal-oxide-semiconductor (CMOS) process compatibility and configurable properties including non-volatile rectification, memorization and learning functions. Herein, recent progress on Tungsten oxide based materials and its associating memory devices had been reviewed. The possible implementation of this material as a bio-inspired artificial synapse is also highlighted. The penultimate section summaries the current research progress for tungsten oxide based biological synapses and end up with several proposals that have been suggested for possible future developments.

  6. Polytetrafluoroethylene-jacketed stirrer modified with graphene oxide and polydopamine for the efficient extraction of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Zhang, Zinxin; Mwadini, Mwadini Ahmada; Chen, Zilin

    2016-10-01

    Steel stirrers jacketed with polytetrafluoroethylene can be regarded as an ideal substrate for stirrer bar sorptive extraction. However, it is still a great challenge to immobilize graphene onto a polytetrafluoroethylene stirrer due to the high chemical resistance of the surface of a polytetrafluoroethylene stirrer. We describe here a method to modify the surface of polytetrafluoroethylene stirrers with graphene. In this work, graphene was used as the sorbent due to its excellent adsorption capability for aromatic compounds, such as polycyclic aromatic compounds. Graphene was successfully immobilized onto polytetrafluoroethylene-stirrer by a bio-inspired polydopamine functionalization method. The graphene-modified polytetrafluoroethylene-stirrer shows good stability and tolerance to stirring, ultrasonication, strong acidic and basic solutions, and to organic solvents. The multilayer coating was characterized by scanning electronic microscopy and Fourier transform infrared spectroscopy. After the optimization of some experimental conditions, the graphene-modified polytetrafluoroethylene stirrer was used for the stirrer bar sorptive extraction of polycyclic aromatic hydrocarbons, in which the binding between the polycyclic aromatic hydrocarbons and the graphene layer was mainly based on π-π stacking and hydrophobic interactions. The graphene-modified polytetrafluoroethylene-stirrer-based stirrer bar sorptive extraction and high-performance liquid chromatography method was developed for the determination of polycyclic aromatic hydrocarbons with great extraction efficiency, with enrichment factors from 18 to 62. The method has low limits of detection of 1-5 pg/mL, wide linear range (5-100 and 10-200 pg/mL), good linearity (R ≥ 0.9957) and good reproducibility (RSD ≤ 6.45%). The proposed method has been applied to determine polycyclic aromatic hydrocarbons in real dust samples. Good recoveries were obtained, ranging from 88.53 to 109.43%.

  7. Characterization and analysis of Devonian shales as related to release of gaseous hydrocarbons. Quarterly technical progress report, April--June 1978

    Energy Technology Data Exchange (ETDEWEB)

    Kalyoncu, R.S.; Snyder, M.J.

    1978-08-08

    Objective is to determine the relationships between the shale characteristics, hydrocarbon gas contents, and well location, for assessing the productive capacity of the Eastern Devonian Gas Shale deposits and guiding research, development, and demonstration projects to enhance the recovery of natural gas from the shale deposits. One well was sampled during this reporting period. Another well from Monongalia County, WV (M-1) was cored in April. 31 samples were obtained for Battelle with additional 55 samples canned for other DOE contractors. Characterization tasks on shale samples from R-146 (Mason County, WV.) and M-1 wells (Monongalia) have been completed. In the preliminary analysis correlations were observed between the hydrocarbon gas contents and can pressure, propane content, well location, oxygen content CO/sub 2/ content, bulk density and carbon contents. Higher pressures are attributed to higher hydrocarbon gas contents. For high gas pressures, propane content is an important indication of hydrocarbon gas content. At low gas pressure, butane contents more accurately predict the hydrocarbon gas contents. High CO/sub 2/ and carbon contents indicate high hydrocarbon gas values, whereas oxygen contents are inversely related to hydrocarbon gas contents. Analysis of the limited wire-line log data shows that correlations between the laboratory and well log data can be utilized to predict potential hydrocarbon gas contents of the wells. 15 tables, 27 figures.

  8. Associations between polycyclic aromatic hydrocarbon (PAH) exposure and oxidative stress in people living near e-waste recycling facilities in China.

    Science.gov (United States)

    Lu, Shao-You; Li, Yan-Xi; Zhang, Jian-Qing; Zhang, Tao; Liu, Gui-Hua; Huang, Ming-Zhi; Li, Xiao; Ruan, Ju-Jun; Kannan, Kurunthachalam; Qiu, Rong-Liang

    2016-09-01

    Emission of polycyclic aromatic hydrocarbons (PAHs) from e-waste recycling activities in China is known. However, little is known on the association between PAH exposure and oxidative damage to DNA and lipid content in people living near e-waste dismantling sites. In this study, ten hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and two biomarkers [8-hydroxy-2'-deoxyguanosine (8-OHdG) and malondialdehyde (MDA)] of oxidative stress were investigated in urine samples collected from people living in and around e-waste dismantling facilities, and in reference population from rural and urban areas in China. The urinary levels of ∑10OH-PAHs determined in e-waste recycling area (GM: 25.4μg/g Cre) were significantly higher (pe-waste workers (36.6μg/g Cre) showed significantly higher (pe-waste recycling site. The differences in urinary Σ10OH-PAHs levels between smokers (23.4μg/g Cre) and non-smokers (24.7μg/g Cre) were not significant (p>0.05) in e-waste dismantling sites, while these differences were significant (pe-waste dismantling site. Furthermore, we found that urinary concentrations of Σ10OH-PAHs and individual OH-PAHs were significantly associated with elevated 8-OHdG, in samples collected from e-waste dismantling site; the levels of urinary 1-hydroxypyrene (1-PYR) (r=0.284, pe-waste dismantling site may have an effect on oxidative damage to DNA among selected participants, but this needs to be validated in large studies.

  9. Solid oxide fuel cell (SOFC) systems with integrated reforming or gasification of hydrocarbons; Solid Oxide Fuel Cell (SOFC)-Systeme mit integrierter Reformierung bzw. Vergasung von Kohlenwasserstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Schlitzberger, Christian

    2012-07-01

    hydrocarbons as fuel are simulated. The simulation results serve as base for the final evaluation of the stack- and system-design concerning operation and feasibility and show the capability of the concept to meet the demands listed above as high electrical system-efficiencies up to 70% and nearly efficiency-neutral CO{sub 2}-separation. [German] In der Arbeit werden innovative Konzepte fuer baulich, thermisch und stofflich hochintegrierte oxidkeramische Brennstoffzellen (Solid Oxide Fuel Cell (SOFC))-Systeme mit optionaler CO{sub 2}-Abscheidung entwickelt und untersucht. Zunaechst erfolgt die Ausarbeitung von Moeglichkeiten zur Wirkungsgradsteigerung, wie die Verschaltung der Gaserzeugungseinheit mit der Brennstoffzelle nach dem Prinzip der chemischen Waermepumpe oder die serielle elektrische Verschaltung der Einzelzellen. Diese Optionen werden anschliessend bezueglich ihrer thermodynamischen Grenzen, wie maximal erzielbare Wirkungsgrade oder maximal moeglicher interner Abwaermenutzung, evaluiert. Darauf aufbauend erfolgt unter Beachtung des Stands der Technik eine methodische Konzeption und Konstruktion eines SOFC-Systems, bei dem Reformierungsreaktor, Brennstoffzelle sowie die thermische Gaskonditionierung in einem Stack-Modul vereint sind. Diese Grundeinheit kann den Anwendungs-, Betriebs-und Brennstoffanforderungen angepasst werden und stellt aufgrund des hohen baulichen Integrationsgrades sowie der nur geringen Anzahl an zusaetzlich benoetigten peripheren Komponenten ein sehr kompaktes System dar. Der zweite Teil der Arbeit beschreibt die mathematische Modeliierung der entsprechenden Systemkomponenten sowie die Modellimplementierung in das institutseigene, C++ basierte Kreislaufsimulationsprogramm ENBIPRO (Energie-Bilanz-Programm). Mittels der mathematischen Modelle werden SOFC-Systeme basierend auf dem entwickelten integrierten Stack-und System-Konzept fuer verschiedene Brennstoffe und Systemverschaltungen simuliert. Die Simulationsergebnisse dienen als Grundlage fuer

  10. Cuprous oxide nanoparticle-inhibited melanoma progress by targeting melanoma stem cells.

    Science.gov (United States)

    Yu, Bin; Wang, Ye; Yu, Xinlu; Zhang, Hongxia; Zhu, Ji; Wang, Chen; Chen, Fei; Liu, Changcheng; Wang, Jingqiang; Zhu, Haiying

    2017-01-01

    Recent studies have shown that metal and metal oxide have a potential function in antitumor therapy. Our previous studies demonstrated that cuprous oxide nanoparticles (CONPs) not only selectively induce apoptosis of tumor cells in vitro but also inhibit the growth and metastasis of melanoma by targeting mitochondria with little hepatic and renal toxicities in mice. As a further study, our current research revealed that CONPs induced apoptosis of human melanoma stem cells (CD271(+/high) cells) in A375 and WM266-4 melanoma cell lines and could significantly suppress the expression of MITF, SOX10 and CD271 involved in the stemness maintenance and tumorigenesis of melanoma stem cells. CD271(+/high) cells could accumulate more CONPs than CD271(-/low) through clathrin-mediated endocytosis. In addition, lower dosage of CONPs exhibited good anti-melanoma effect by decreasing the cell viability, stemness and tumorigenesis of A375 and WM266-4 cells through reducing the expression of SOX10, MITF, CD271 and genes in MAPK pathway involved in tumor progression. Finally, CONPs obviously suppressed the growth of human melanoma in tumor-bearing nonobese diabetic-severe combined immunodeficiency (NOD-SCID) mice, accompanied with tumors structural necrosis and fibrosis remarkably and decreased expression of CD271, SOX10 and MITF. These results above proved the effectiveness of CONPs in inhibiting melanoma progress through multiple pathways, especially through targeting melanoma stem cells.

  11. Nanochips of Tantalum Oxide Nanodots as artificial-microenvironments for monitoring Ovarian cancer progressiveness

    Science.gov (United States)

    Dhawan, Udesh; Wang, Ssu-Meng; Chu, Ying Hao; Huang, Guewha S.; Lin, Yan Ren; Hung, Yao Ching; Chen, Wen Liang

    2016-08-01

    Nanotopography modulates cell characteristics and cell behavior. Nanotopological cues can be exploited to investigate the in-vivo modulation of cell characteristics by the cellular microenvironment. However, the studies explaining the modulation of tumor cell characteristics and identifying the transition step in cancer progressiveness are scarce. Here, we engineered nanochips comprising of Tantalum oxide nanodot arrays of 10, 50, 100 and 200 nm as artificial microenvironments to study the modulation of cancer cell behavior. Clinical samples of different types of Ovarian cancer at different stages were obtained, primary cultures were established and then seeded on different nanochips. Immunofluorescence (IF) was performed to compare the morphologies and cell characteristics. Indices corresponding to cell characteristics were defined. A statistical comparison of the cell characteristics in response to the nanochips was performed. The cells displayed differential growth parameters. Morphology, Viability, focal adhesions, microfilament bundles and cell area were modulated by the nanochips which can be used as a measure to study the cancer progressiveness. The ease of fabrication of nanochips ensures mass-production. The ability of the nanochips to act as artificial microenvironments and modulate cell behavior may lead to further prospects in the markerless monitoring of the progressiveness and ultimately, improving the prognosis of Ovarian cancer.

  12. Simultaneous NOx and hydrocarbon emissions control for lean-burn engines using low-temperature solid oxide fuel cell at open circuit.

    Science.gov (United States)

    Huang, Ta-Jen; Hsu, Sheng-Hsiang; Wu, Chung-Ying

    2012-02-21

    The high fuel efficiency of lean-burn engines is associated with high temperature and excess oxygen during combustion and thus is associated with high-concentration NO(x) emission. This work reveals that very high concentration of NO(x) in the exhaust can be reduced and hydrocarbons (HCs) can be simultaneously oxidized using a low-temperature solid oxide fuel cell (SOFC). An SOFC unit is constructed with Ni-YSZ as the anode, YSZ as the electrolyte, and La(0.6)Sr(0.4)CoO(3) (LSC)-Ce(0.9)Gd(0.1)O(1.95) as the cathode, with or without adding vanadium to LSC. SOFC operation at 450 °C and open circuit can effectively treat NO(x) over the cathode at a very high concentration in the simulated exhaust. Higher NO(x) concentration up to 5000 ppm can result in a larger NO(x) to N(2) rate. Moreover, a higher oxygen concentration promotes NO conversion. Complete oxidation of HCs can be achieved by adding silver to the LSC current collecting layer. The SOFC-based emissions control system can treat NO(x) and HCs simultaneously, and can be operated without consuming the anode fuel (a reductant) at near the engine exhaust temperature to eliminate the need for reductant refilling and extra heating.

  13. Screening of MgO- and CeO2-Based Catalysts for Carbon Dioxide Oxidative Coupling of Methane to C2+ Hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    Istadi; Nor Aishah Saidina Amin

    2004-01-01

    The catalyst screening tests for carbon dioxide oxidative coupling of methane (CO2-OCM)have been investigated over ternary and binary metal oxide catalysts. The catalysts are prepared by doping MgO- and CeO2-based solids with oxides from alkali (Li2O), alkaline earth (CaO), and transition metal groups (WO3 or MnO). The presence of the peroxide (O22-) active sites on the Li2O2, revealed by Raman spectroscopy, may be the key factor in the enhanced performance of some of the Li2O/MgO catalysts.The high reducibility of the CeO2 catalyst, an important factor in the CO2-OCM catalyst activity, may be enhanced by the presence of manganese oxide species. The manganese oxide species increases oxygen mobility and oxygen vacancies in the CeO2 catalyst. Raman and Fourier Transform Infra Red (FT-IR) spectroscopies revealed the presence of lattice vibrations of metal-oxygen bondings and active sites in which the peaks corresponding to the bulk crystalline structures of Li2O, CaO, WO3 and MnO are detected. The performance of 5%MnO/15%CaO/CeO2 catalyst is the most potential among the CeO2-based catalysts,although lower than the 2%Li2O/MgO catalyst. The 2%Li2O/MgO catalyst showed the most promising C2+ hydrocarbons selectivity and yield at 98.0% and 5.7%, respectively.

  14. Assessment of association of exposure to polycyclic aromatic hydrocarbons with bronchial asthma and oxidative stress in children: A case control study

    Directory of Open Access Journals (Sweden)

    Suresh Ram

    2009-01-01

    Full Text Available Background: Polycyclic aromatic hydrocarbons (PAH originate from the incomplete combustion of organic matter and ambient air pollution by these is increasing. There is also an increase in the global prevalence of asthma, for which environmental pollution has been recognized as one of the important factors. Exposure to pollutants and other allergens induces chronic airway inflammation by generation of reactive oxygen species, causing oxidative stress. Therefore, the objective of the present study was to assess association, if any, between exposure to PAH and asthma as well as oxidative stress in children. Method: In this hospital-based case control study, cases of bronchial asthma aged 1-14 years and healthy matched controls were included. Oxidative stress was measured by assessing the levels of enzymes catalase, superoxide dismutase, malondialdehyde (MDA, and reduced glutathione (GSH. Results : Forty-two cases and 20 controls were enrolled. Mean blood level of phenanthrene, a PAH, was 63.11 ppb ± 115.62 and 4.20 ppb ± 10.68 ppb in cases and controls, respectively ( P = 0.02. Mean blood levels of GSH was significantly lower in cases and controls (27.39 mg/ml ± 11.09 versus 47.39 g/ml ± 13.83; P -value = 0.001. Likewise, mean blood level of MDA in nanomole/ml was significantly higher in asthma as compared with controls (12.85 ± 5.40 versus 8.19 ± 5.16; P -value = 0.002, suggestive of increased oxidative stress. Conclusions: Because elevated blood level of phenanthrene is associated with bronchial asthma as well as with oxidative stress, measures to reduce exposure to PAH may possibly lead to reduced incidence and severity of bronchial asthma.

  15. Health effects of combustion-generated soot and polycyclic aromatic hydrocarbons. Progress report, May 1, 1979-April 30, 1980. [Lead abstract

    Energy Technology Data Exchange (ETDEWEB)

    Thilly, W. G.

    1980-05-01

    Mutagen studies on soot and soot components are reported in aspects dealing from quantitative chemical analyses of samples and mutagenesis of cells and microorganisms exposed to mutagens, to bioassay developments and techniques. Several polycyclic aromatic hydrocarbons are characterized and discussed.

  16. [The use of the [13C]/[12C] ratio for the assay of the microbial oxidation of hydrocarbons].

    Science.gov (United States)

    Ziakun, A M; Kosheleva, I A; Zakharchenko, V N; Kudriavtseva, A I; Peshenko, V A; Filonov, A E; Boronin, A M

    2003-01-01

    The study deals with a comparative analysis of the relative abundances of the carbon isotopes 12C and 13C in the metabolites and biomass of the Burkholderia sp. BS3702 and Pseudomonas putida BS202-p strains capable of utilizing aliphatic (n-hexadecane) and aromatic (naphthalene) hydrocarbons as sources of carbon and energy. The isotope composition of the carbon dioxide, biomass, and exometabolites produced during the growth of Burkholderia sp. BS3702 on n-hexadecane (delta 13C = -44.6 +/- 0.2@1000) were characterized by the isotope effects delta 13CCO2 = -50.2 +/- 0.4@1000, delta 13Cbiom = -46.6 +/- 0.4@1000 and delta 13Cexo = -41.5 +/- 0.4@1000, respectively. The isotope composition of the carbon dioxide, biomass, and exometabolites produced during the growth of the same bacterial strain on naphthalene (delta 13C = -21 +/- 0.4@1000) were characterized by the isotope effects delta 13CCO2 = -24.1 +/- 0.4@1000, delta 13Cbiom = -19.2 +/- 0.4@1000 and delta 13Cexo = -19.1 +/- 0.4@1000, respectively. The possibility of using the isotope composition of metabolic carbon dioxide for the rapid monitoring of the microbial degradation of petroleum hydrocarbons in the enviroment is discussed.

  17. Kefir administration reduced progression of renal injury in STZ-diabetic rats by lowering oxidative stress.

    Science.gov (United States)

    Punaro, Giovana R; Maciel, Fabiane R; Rodrigues, Adelson M; Rogero, Marcelo M; Bogsan, Cristina S B; Oliveira, Marice N; Ihara, Silvia S M; Araujo, Sergio R R; Sanches, Talita R C; Andrade, Lucia C; Higa, Elisa M S

    2014-02-15

    This study aimed at assessing the effects of Kefir, a probiotic fermented milk, on oxidative stress in diabetic animals. The induction of diabetes was achieved in adult male Wistar rats using streptozotocin (STZ). The animals were distributed into four groups as follows: control (CTL); control Kefir (CTLK); diabetic (DM) and diabetic Kefir (DMK). Starting on the 5th day of diabetes, Kefir was administered by daily gavage at a dose of 1.8 mL/day for 8 weeks. Before and after Kefir treatment, the rats were placed in individual metabolic cages to obtain blood and urine samples to evaluate urea, creatinine, proteinuria, nitric oxide (NO), thiobarbituric acid reactive substances (TBARS) and C-reactive protein (CRP). After sacrificing the animals, the renal cortex was removed for histology, oxidative stress and NOS evaluation. When compared to CTL rats, DM rats showed increased levels of glycemia, plasmatic urea, proteinuria, renal NO, superoxide anion, TBARS, and plasmatic CRP; also demonstrated a reduction in urinary urea, creatinine, and NO. However, DMK rats showed a significant improvement in most of these parameters. Despite the lack of differences observed in the expression of endothelial NO synthase (eNOS), the expression of inducible NO synthase (iNOS) was significantly lower in the DMK group when compared to DM rats, as assessed by Western blot analysis. Moreover, the DMK group presented a significant reduction of glycogen accumulation within the renal tubules when compared to the DM group. These results indicate that Kefir treatment may contribute to better control of glycemia and oxidative stress, which is associated with the amelioration of renal function, suggesting its use as a non-pharmacological adjuvant to delay the progression of diabetic complications.

  18. Advanced experimental analysis of controls on microbial Fe(III) oxide reduction. First year progress report

    Energy Technology Data Exchange (ETDEWEB)

    Roden, E.E.; Urrutia, M.M.

    1997-07-01

    'The authors have made considerable progress toward a number of project objectives during the first several months of activity on the project. An exhaustive analysis was made of the growth rate and biomass yield (both derived from measurements of cell protein production) of two representative strains of Fe(III)-reducing bacteria (Shewanellaalga strain BrY and Geobactermetallireducens) growing with different forms of Fe(III) as an electron acceptor. These two fundamentally different types of Fe(III)-reducing bacteria (FeRB) showed comparable rates of Fe(III) reduction, cell growth, and biomass yield during reduction of soluble Fe(III)-citrate and solid-phase amorphous hydrous ferric oxide (HFO). Intrinsic growth rates of the two FeRB were strongly influenced by whether a soluble or a solid-phase source of Fe(III) was provided: growth rates on soluble Fe(III) were 10--20 times higher than those on solid-phase Fe(III) oxide. Intrinsic FeRB growth rates were comparable during reduction of HF0 and a synthetic crystalline Fe(III) oxide (goethite). A distinct lag phase for protein production was observed during the first several days of incubation in solid-phase Fe(III) oxide medium, even though Fe(III) reduction proceeded without any lag. No such lag between protein production and Fe(III) reduction was observed during growth with soluble Fe(III). This result suggested that protein synthesis coupled to solid-phase Fe(III) oxide reduction in batch culture requires an initial investment of energy (generated by Fe(III) reduction), which is probably needed for synthesis of materials (e.g. extracellular polysaccharides) required for attachment of the cells to oxide surfaces. This phenomenon may have important implications for modeling the growth of FeRB in subsurface sedimentary environments, where attachment and continued adhesion to solid-phase materials will be required for maintenance of Fe(III) reduction activity. Despite considerable differences in the rate and

  19. IDENTIFICATION OF PRODUCTS CONTAINING -COOH, -OH, AND -C==O IN ATMOSPHERIC OXIDATION OF HYDROCARBONS. (R824970)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  20. Oxidative stress responses of gulf killifish exposed to hydrocarbons from the Deepwater Horizon oil spill: Potential implications for aquatic food resources.

    Science.gov (United States)

    Crowe, Kristi M; Newton, Joseph C; Kaltenboeck, Bernhard; Johnson, Calvin

    2014-02-01

    Ecosystem effects of polycyclic aromatic hydrocarbons (PAHs) remain under investigation following the Gulf of Mexico Deepwater Horizon oil spill. Fundulus grandis, an established indicator of aquatic ecosystem health, was investigated because this species shares genes and biochemical pathways with higher trophic-level fish and plays an important role in the gulf food chain. Oxidative stress responses including hepatic cytochrome P4501A (CYP1A) and serum antioxidant capacity were evaluated in fish exposed to PAHs. Fish were exposed to water-accommodated fractions (WAFs) of crude oil (7.0  ± 0.10 mg/L C6-C28) after which solutions were diluted below the level of detection over 8 h using 15 ppt aerated artificial seawater. Before euthanasia, fish remained in aquaria for 12 h, 24 h, or 48 h. Three replicate experiments were conducted at each time point using unexposed fish as experimental controls. Significant differences (p < 0.05) in CYP1A induction were observed in exposed versus control fish at 24 h. Expression of CYP1A increased by 25%, 66%, and 23% in exposed fish at 12 h, 24 h, and 48 h, respectively. Significant increases were observed in antioxidant capacity of nonenzymatic antioxidants in exposed versus control fish at each time point. Given the activity of CYP1A, radicals formed during PAH detoxification likely resulted in increased oxidant load requiring elevated antioxidant defenses. Research is needed to determine the duration of oxidative stress responses considering the potential for lipid oxidation in exposed fish or species feeding on exposed fish.

  1. The effects of oxygen on the yields of polycyclic aromatic hydrocarbons formed during the pyrolysis and fuel-rich oxidation of catechol

    Energy Technology Data Exchange (ETDEWEB)

    Shiju Thomas; Mary J. Wornat [Louisiana State University, Baton Rouge, LA (United States). Department of Chemical Engineering

    2008-05-15

    To better understand the effects of oxygen on the formation and destruction of polycyclic aromatic hydrocarbons (PAH) during the burning of complex solid fuels, we have performed pyrolysis and fuel-rich oxidation experiments in an isothermal laminar-flow reactor, using the model fuel catechol (ortho-dihydroxybenzene), a phenol-type compound representative of structural entities in coal, wood, and biomass. The catechol pyrolysis experiments are conducted at a fixed residence time of 0.3 s, at nine temperatures spanning the range of 500-1000{sup o}C, and under varying oxygen ratios ranging from 0 (pure pyrolysis) to 0.92 (near stoichiometric oxidation). The PAH products, ranging in size from two to nine fused aromatic rings, have been analyzed by gas chromatography with flame-ionization and mass spectrometric detection, and by high-pressure liquid chromatography with diode-array ultraviolet-visible absorbance detection. The quantified PAH products fall into six structural classes. A comparison of product yields from pyrolysis and fuel-rich oxidation of catechol reveals that at temperatures {lt}800{sup o}C, where only two-ring PAH are produced in significant quantities, increases in oxygen concentration bring about increases in yields of the two-ring aromatics indene and naphthalene. At temperatures {gt}800{sup o}C, increases in oxygen concentration bring about dramatic decreases in the yields of all PAH products, due to oxidative destruction reactions. The smaller-ring-number PAH are produced in higher abundance under all conditions studied, and the oxygen-induced decreases in the yields of PAH are increasingly more pronounced as the PAH ring number is increased. These observations fully support our finding from catechol pyrolysis in the absence of oxygen: that PAH formation and growth occur by successive ring-buildup reactions involving the C1-C5 and single-ring aromatic products of catechol's thermal decomposition. 51 refs., 26 figs., 1 tab.

  2. A new oxo-vanadium complex employing an imidazole-rich tripodal ligand: a bioinspired bromide and hydrocarbon oxidation catalyst.

    Science.gov (United States)

    Fernández, Tatiana L; Souza, Elizabeth T; Visentin, Lorenzo C; Santos, Jeniffer V; Mangrich, Antonio S; Faria, Roberto B; Antunes, O A C; Scarpellini, Marciela

    2009-04-01

    A vanadyl complex with the ligand (bis(1-methylimidazol-2-yl)methyl)(2-(pyridyl-2-yl)ethyl)amine was synthesized and fully characterized by X-ray crystallography, elemental analyses, cyclic voltammetry and infrared, electronic and electron paramagnetic resonance spectroscopies. This compound was designed under the so called hybrid concept. It shows to be able to promiscuously use hydrogen peroxide to oxidize bromide and to catalyze the oxidation of benzene and cyclohexane with very good selectivities.

  3. Method of CO and/or CO.sub.2 hydrogenation to higher hydrocarbons using doped mixed-metal oxides

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-03-21

    A method of hydrogenation utilizing a reactant gas mixture comprising a carbon oxide and a hydrogen agent, and a hydrogenation catalyst comprising a mixed-metal oxide containing metal sites supported and/or incorporated into the lattice. The mixed-metal oxide comprises a pyrochlore, a brownmillerite, or mixtures thereof doped at the A-site or the B-site. The metal site may comprise a deposited metal, where the deposited metal is a transition metal, an alkali metal, an alkaline earth metal, or mixtures thereof. Contact between the carbon oxide, hydrogen agent, and hydrogenation catalyst under appropriate conditions of temperature, pressure and gas flow rate generate a hydrogenation reaction and produce a hydrogenated product made up of carbon from the carbon oxide and some portion of the hydrogen agent. The carbon oxide may be CO, CO.sub.2, or mixtures thereof and the hydrogen agent may be H.sub.2. In a particular embodiment, the hydrogenated product comprises olefins, paraffins, or mixtures thereof.

  4. Synthesis and characterization of mangenese(III) porphyrin supported on imidazole modified chloromethylated MIL-101(Cr): A heterogeneous and reusable catalyst for oxidation of hydrocarbons with sodium periodate

    Energy Technology Data Exchange (ETDEWEB)

    Zadehahmadi, Farnaz; Tangestaninejad, Shahram, E-mail: stanges@sci.ui.ac.ir; Moghadam, Majid, E-mail: moghadamm@sci.ui.ac.ir; Mirkhani, Valiollah, E-mail: mirkhani@sci.ui.ac.ir; Mohammadpoor-Baltork, Iraj; Khosropour, Ahmad R.; Kardanpour, Reihaneh

    2014-10-15

    In the present work, chloromethylated MIL-101(Cr) modified with imidazole, Im-MIL-101, was applied as a support for immobilizing of tetraphenylporphyrinatomangenese(III) chloride. The imidazole-bound MIL-101, Im-MIL-101, not only used as support for immobilization of manganese porphyrin but also applied as a heterogeneous axial base. The Mn(TPP)Cl@Im-MIL-101 catalyst was characterized by UV–vis, FT-IR, X-ray diffraction (XRD), N{sub 2} adsorption, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX), elemental analysis and inductively coupled plasma (ICP) methods. The catalytic activity of this new catalytic system was investigated in the alkene epoxidation and alkane hydroxylation using NaIO{sub 4} as an oxidant in CH{sub 3}CN/H{sub 2}O at room temperature. This heterogeneous catalyst is highly efficient, stable and reusable in the oxidation of hydrocarbons. - Highlights: • MIL-101 was modified by covalent post synthetic modification. • Mn(TPP)Cl was anchored to imidazole modified MIL-101 by covalent attachment. • A heterogeneous catalyst was prepared. • The catalyst was used for epoxidation of alkenes and hydroxylation of alkanes. • The catalyst was reusable.

  5. Lactobacillus acidophilus ATCC 4356 attenuates the atherosclerotic progression through modulation of oxidative stress and inflammatory process.

    Science.gov (United States)

    Chen, Lihua; Liu, Wenen; Li, Yanming; Luo, San; Liu, Qingxia; Zhong, Yiming; Jian, Zijuan; Bao, Meihua

    2013-09-01

    The aim of this study was to investigate the effect of Lactobacillus (L.) acidophilus ATCC 4356 on the progression of atherosclerosis in Apoliprotein-E knockout (ApoE(-/-)) mice and the underlying mechanisms. Eight week-old ApoE(-/-) mice were treated with L. acidophilus ATCC 4356 daily for 12 weeks. The wild type (WT) mice or ApoE(-/-) mice in the vehicle group were treated with saline only. Body weights, serum lipid levels, aortic atherosclerotic lesions, and tissue oxidative and inflammatory statuses were examined among the groups. As compared to ApoE(-/-) mice in the vehicle group, ApoE(-/-) mice treated with L. acidophilus ATCC 4356 had no changes in body weights and serum lipid profiles, but showed decreased atherosclerotic lesion size in en face aorta. In comparison with WT mice, ApoE(-/-) mice in the vehicle group showed higher levels of serum malondialdehyde (MDA), oxidized low density lipoprotein (oxLDL) and tumor necrosis factor-alpha (TNF-α), but lower levels of interleukin-10 (IL-10) and superoxide dismutase (SOD) activities in serum. Administration of L. acidophilus ATCC 4356 could reverse these trends in a dose-dependent manner in ApoE(-/-) mice. Furthermore, ApoE(-/-) mice treated with L. acidophilus ATCC 4356 showed an inhibition of translocation of NF-κB p65 from cytoplasm to nucleus, suppression of degradation of aortic IκB-α, and improvements of gut microbiota distribution, as compared to ApoE(-/-) mice in the vehicle group. Our findings suggest that administration of L. acidophilus ATCC 4356 can attenuate the development of atherosclerotic lesions in ApoE(-/-) mice through reducing oxidative stress and inflammatory response.

  6. Indium oxide (In2O3) nanoparticles induce progressive lung injury distinct from lung injuries by copper oxide (CuO) and nickel oxide (NiO) nanoparticles.

    Science.gov (United States)

    Jeong, Jiyoung; Kim, Jeongeun; Seok, Seung Hyeok; Cho, Wan-Seob

    2016-04-01

    Indium is an essential element in the manufacture of liquid crystal displays and other electronic devices, and several forms of indium compounds have been developed, including nanopowders, films, nanowires, and indium metal complexes. Although there are several reports on lung injury caused by indium-containing compounds, the toxicity of nanoscale indium oxide (In2O3) particles has not been reported. Here, we compared lung injury induced by a single exposure to In2O3 nanoparticles (NPs) to that caused by benchmark high-toxicity nickel oxide (NiO) and copper oxide (CuO) NPs. In2O3 NPs at doses of 7.5, 30, and 90 cm(2)/rat (50, 200, and 600 µg/rat) were administered to 6-week-old female Wistar rats via pharyngeal aspiration, and lung inflammation was evaluated 1, 3, 14, and 28 days after treatment. Neutrophilic inflammation was observed on day 1 and worsened until day 28, and severe pulmonary alveolar proteinosis (PAP) was observed on post-aspiration days 14 and 28. In contrast, pharyngeal aspiration of NiO NPs showed severe neutrophilic inflammation on day 1 and lymphocytic inflammation with PAP on day 28. Pharyngeal aspiration of CuO NPs showed severe neutrophilic inflammation on day 1, but symptoms were completely resolved after 14 days and no PAP was observed. The dose of In2O3 NPs that produced progressive neutrophilic inflammation and PAP was much less than the doses of other toxic particles that produced this effect, including crystalline silica and NiO NPs. These results suggest that occupational exposure to In2O3 NPs can cause severe lung injury.

  7. Enhancement of in situ Remediation of Hydrocarbon Contaminated Soil

    Energy Technology Data Exchange (ETDEWEB)

    Palmroth, M.

    2006-07-01

    Approximately 750 000 sites of contaminated land exist across Europe. The harmful chemicals found in Finnish soils include heavy metals, oil products, polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), chlorophenols, and pesticides. Petroleum and petroleum products enter soil from ruptured oil pipelines, land disposal of refinery products, leaking storage tanks and through accidents. PAH contamination is caused by the spills of coal tar and creosote from coal gasification and wood treatment sites in addition to oil spills. Cleanup of soil by bioremediation is cheaper than by chemical and physical processes. However, the cleaning capacity of natural attenuation and in situ bioremediation is limited. The purpose of this thesis was to find feasible options to enhance in situ remediation of hydrocarbon contaminants. The aims were to increase the bioavailability of the contaminants and microbial activity at the subsurface in order to achieve higher contaminant removal efficiency than by intrinsic biodegradation alone. Enhancement of microbial activity and decrease of soil toxicity during remediation were estimated by using several biological assays. The performance of these assays was compared in order to find suitable indicators to follow the progress of remediation. Phytoremediation and chemical oxidation are promising in situ techniques to increase the degradation of hydrocarbons in soil. Phytoremediation is plant-enhanced decontamination of soil and water. Degradation of hydrocarbons is enhanced in the root zone by increased microbial activity and through the detoxifying enzymes of plants themselves. Chemical oxidation of contaminants by Fenton's reaction can produce degradation products which are more biodegradable than the parent compounds. Fenton's reaction and its modifications apply solutions of hydrogen peroxide and iron for the oxidation of organic chemicals. The cost of oxidation can be reduced by aiming at partial instead of full

  8. Diphenylarsinic acid, a chemical warfare-related neurotoxicant, promotes liver carcinogenesis via activation of aryl hydrocarbon receptor signaling and consequent induction of oxidative DAN damage in rats

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Min; Yamada, Takanori; Yamano, Shotaro; Kato, Minoru; Kakehashi, Anna; Fujioka, Masaki; Tago, Yoshiyuki; Kitano, Mistuaki; Wanibuchi, Hideki, E-mail: wani@med.osaka-cu.ac.jp

    2013-11-15

    Diphenylarsinic acid (DPAA), a chemical warfare-related neurotoxic organic arsenical, is present in the groundwater and soil in some regions of Japan due to illegal dumping after World War II. Inorganic arsenic is carcinogenic in humans and its organic arsenic metabolites are carcinogenic in animal studies, raising serious concerns about the carcinogenicity of DPAA. However, the carcinogenic potential of DPAA has not yet been evaluated. In the present study we found that DPAA significantly enhanced the development of diethylnitrosamine-induced preneoplastic lesions in the liver in a medium-term rat liver carcinogenesis assay. Evaluation of the expression of cytochrome P450 (CYP) enzymes in the liver revealed that DPAA induced the expression of CYP1B1, but not any other CYP1, CYP2, or CYP3 enzymes, suggesting that CYP1B1 might be the enzyme responsible for the metabolic activation of DPAA. We also found increased oxidative DNA damage, possibly due to elevated CYP1B1 expression. Induction of CYP1B1 has generally been linked with the activation of AhR, and we found that DPAA activates the aryl hydrocarbon receptor (AhR). Importantly, the promotion effect of DPAA was observed only at a dose that activated the AhR, suggesting that activation of AhR and consequent induction of AhR target genes and oxidative DNA damage plays a vital role in the promotion effects of DPAA. The present study provides, for the first time, evidence regarding the carcinogenicity of DPAA and indicates the necessity of comprehensive evaluation of its carcinogenic potential using long-term carcinogenicity studies. - Highlights: • DPAA, an environmental neurotoxicant, promotes liver carcinogenesis in rats. • DPAA is an activator of AhR signaling pathway. • DPAA promoted oxidative DNA damage in rat livers. • AhR target gene CYP 1B1 might be involved in the metabolism of DPAA.

  9. Development of a detailed chemical mechanism (MCMv3.1 for the atmospheric oxidation of aromatic hydrocarbons

    Directory of Open Access Journals (Sweden)

    C. Bloss

    2005-01-01

    Full Text Available The Master Chemical Mechanism has been updated from MCMv3 to MCMv3.1 in order to take into account recent improvements in the understanding of aromatic photo-oxidation. Newly available kinetic and product data from the literature have been incorporated into the mechanism. In particular, the degradation mechanisms for hydroxyarenes have been revised following the observation of high yields of ring-retained products, and product studies of aromatic oxidation under relatively low NOx conditions have provided new information on the branching ratios to first generation products. Experiments have been carried out at the European Photoreactor (EUPHORE to investigate key subsets of the toluene system. These results have been used to test our understanding of toluene oxidation, and, where possible, refine the degradation mechanisms. The evaluation of MCMv3 and MCMv3.1 using data on benzene, toluene, p-xylene and 1,3,5-trimethylbenzene photosmog systems is described in a companion paper, and significant model shortcomings are identified. Ideas for additional modifications to the mechanisms, and for future experiments to further our knowledge of the details of aromatic photo-oxidation are discussed.

  10. Development of a detailed chemical mechanism (MCMv3.1 for the atmospheric oxidation of aromatic hydrocarbons

    Directory of Open Access Journals (Sweden)

    C. Bloss

    2004-09-01

    Full Text Available The Master Chemical Mechanism has been updated from MCMv3 to MCMv3.1 in order to take into account recent improvements in the understanding of aromatic photo-oxidation. Newly available kinetic and product data from the literature has been incorporated into the mechanism. In particular, the degradation mechanisms for hydroxyarenes have been revised following the observation of high yields of ring-retained products, and product studies of aromatic oxidation under relatively low NOx conditions have provided new information on the branching ratios to first generation products. Experiments have been carried out at the European Photoreactor (EUPHORE to investigate key subsets of the toluene system. These results have been used to test our understanding of toluene oxidation, and where possible, refine the degradation mechanisms. The evaluation of MCMv3 and MCMv3.1 using data on benzene, toluene, p-xylene and 1,3,5-trimethylbenzene photosmog systems is described in a companion paper, and significant model shortcomings are identified. Ideas for additional modifications to the mechanisms, and for future experiments to further our knowledge of the details of aromatic photo-oxidation are discussed.

  11. Progress of research work on blending of surfactants based upon hydrocarbon group%碳氢表面活性剂复配研究的进展

    Institute of Scientific and Technical Information of China (English)

    鲍艳; 吴成兰; 马建中

    2011-01-01

    Classification and characteristics of surfactants based upon hydrocarbon group were presented. Principles with respect to the blending of surfactants based upon hydrocarbon group were introduced, which includes the blending of surfactants of same type as well as surfactants of different types. At the same time,the effects of inorganic electrolytes and polar organics on the blended system of surfactants based upon hydrocarbon group were summarized. Future development of surfactants based upon hydrocarbon group was outlooked.%介绍了碳氢表面活性剂的分类及性能,综述了各类碳氢表面活性剂的复配规律,包括同类型表面活性剂之间的复配及不同类型表面活性剂之间的复配,并介绍了无机电解质及极性有机物对碳氢表面活性剂复配的影响.最后,对碳氢表面活性剂的发展趋势进行了展望.

  12. Characterization and analysis of Devonian shales as related to release of gaseous hydrocarbons. Quarterly technical progress report, October--December 1978

    Energy Technology Data Exchange (ETDEWEB)

    Kalyoncu, R.S.; Snyder, M.J.

    1979-01-15

    The characterization data obtained during the period October through December 1978 are described. One well in Allegany County, New York, was sampled in September 1978. A total of 412 samples were collected from the Allegany County, New York well (165 for Battelle and 247 for other DOE/MERC contractors). Two other wells, namely in Wetzel County, West Virginia and Johnson County, Kentucky, were cored during the last quarter of 1978. A total of 109 samples were obtained from the Wetzel County, West Virginia well (46 samples for Battelle and 63 samples for other DOE/MERC contractors). The samples were obtained from depths of 6100 to 6635 feet. Characterization data on I-2 (EGSP Ind. No. 2), Clark County, Indiana, and Y-1 (EGSP New York No. 1), Allegany County, New York wells are reported and discussed. Analysis of the hydrocarbon gases in Y-1 samples indicates that the longer chain hydrocarbon gases (ethane, propane, butane) in these shales are significantly higher than in the previous wells studied. The Indiana well (I-2) shows surprisingly high carbon contents compared with the hydrocarbon gas contents. The carbon contents of the Y-1 (Allegany County, New York) well, on the other hand, are somewhat lower than would be predicted from the hydrocarbon gas contents. Among the physical properties, the I-2 well generally exhibits lower density values than previously studied shales.

  13. 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.

  14. Relation of oxidant-antioxidant imbalance with disease progression in patients with asthma

    Directory of Open Access Journals (Sweden)

    Asrar Ahmad

    2012-01-01

    Full Text Available Context: Asthma is a chronic airway disorder which is associated to the inflammatory cells. Inflammatory and immune cells generate more reactive oxygen species in patients suffering from asthma which leads to tissue injury. Aims: To investigate the role of oxidant-antioxidant imbalance in disease progression of asthmatic patients. Settings and Design: In this study, 130 asthmatic patients and 70 healthy controls were documented. Methods: For this malondialdehyde level, total protein carbonyls, sulfhydryls, activity of superoxide dismutase (SOD, catalase, glutathione peroxidase (GPx, total blood glutathione, and total antioxidant capacity (FRAP were measured. Statistical Analysis Used: Analysis of the data was done using unpaired student t test and one-way ANOVA analysis. P < 0.05 was considered significant. Results: The present work showed that the systemic levels of MDA (4.19 ± 0.10 nmol/ml, P < 0.001 and protein carbonyls (1.13 ± 0.02 nmol/mg, P < 0.001 were found to be remarkably higher in asthmatic patients while protein sulfhydryls (0.55 ± 0.01 mmol/l, P < 0.05 decreased as compared to controls (2.84 ± 0.12 nmol/ml, 0.79 ± 0.02 nmol/mg and 0.60 ± 0.02 mmol/l, respectively. We also observed decrease in activities of SOD (2047 ± 50.34 U/g Hb, P < 0.05, catalase (4374 ± 67.98 U/g Hb, P < 0.01, and GPx (40.97 ± 1.05 U/g Hb, P < 0.01 in erythrocytes compared to control (2217 ± 60.11 U/g Hb, 4746 ± 89.94 U/g Hb, and 48.37 ± 2.47 U/g Hb, respectively. FRAP level (750.90 ± 21.22 ΅mol/l, P < 0.05 in plasma was decreased, whereas total blood glutathione increased (0.94 ± 0.02 mmol/l, P < 0.05 as seen in control (840.40 ± 28.39 ΅mol/l and 0.84 ± 0.04 mmol/l. Conclusions: This work supports and describes the hypothesis that an imbalance between oxidant-antioxidant is associated to the oxidative stress which plays a significant role in severity of the disease.

  15. Endothelial nitric oxide synthase deficiency influences normal cell cycle progression and apoptosis in trabecular meshwork cells

    Directory of Open Access Journals (Sweden)

    Qiong Liao

    2016-06-01

    Full Text Available AIM: To clarify how the endothelial nitric oxide synthase (eNOS, NOS3 make effect on outflow facility through the trabecular meshwork (TM. METHODS: Inhibition of NOS3 gene expression in human TM cells were conducted by three siRNAs. Then the mRNA and protein levels of NOS3 in siRNA-treated and negative control (NC cells were determined, still were the collagen, type IV, alpha 1 (COL4A1 and fibronectin 1 by real-time PCR and Western blot analysis. In addition, NOS3 concentrations in culture supernatant fluids of TM cells were measured. Cell cycle and cell apoptosis analysis were performed using flow cytometry. RESULTS: The mRNA level of NOS3 was decreased by three different siRNA interference, similar results were obtained not only of the relative levels of NOS3 protein, but also the expression levels of COL4A1 and fibronectin 1. The number of cells in S phase was decreased, while contrary result was obtained in G2 phase. The number of apoptotic cells in siRNA-treated groups were significant increased compared to the NC samples. CONCLUSION: Abnormal NOS3 expression can make effects on the proteins levels of extracellular matrix component (e.g. fibronectin 1 and COL4A1. Reduced NOS3 restrains the TM cell cycle progression at the G2/M-phase transition and induced cell apoptosis.

  16. Progress in Research and Development of Refractory Oxide-Nonoxide Composites

    Institute of Scientific and Technical Information of China (English)

    ZHONG Xiangchong

    2008-01-01

    Some of the progress made in our laboratories in collaboration with industry in research and development work on high performance oxide-nonoxide composites for metallurgical applications has been reviewed. (1) SiAlON bonded corundum composites for blast furnace usage have been produced by reduction-nitridation sintering at high temperature, using bauxite instead of alumina in the matrix. (2) Low carbon Al2O3-SiAlON slide plate materials successfully used in high quality steel continuous casting have been developed in which most or all of the graphite in Al2O3-C brick is replaced by bauxite-based β-SiAlON. (3) Al/Si metal bonded Al2O3-C material characterized by low carbon content, low firing temperature and in-situ formation of carbides and nitrides at high temperature during service are found to possess very high hot strength and very good thermal shock resistance and have also been successfully used as slide plates in ladles and tundishes for high quality steel casting.

  17. 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.

  18. Features of non-oxidative conversion of methane into aromatic hydrocarbons over Mo-containing zeolite catalysts

    Science.gov (United States)

    Stepanov, A. A.; Korobitsyna, L. L.; Vosmerikov, A. V.

    2016-09-01

    The results of study of methane conversion under non-oxidative conditions over molybdenum containing zeolite catalysts prepared by solid-phase synthesis using nanosized molybdenum powder are presented. The kinetic mechanisms of the process behavior under different conditions of methane dehydroaromatization are determined. It is shown that nonoxidative conversion of methane can occur both in the external diffusion and kinetic regions, depending on the methane flow rate. It is found out, that the optimum temperature of the methane conversion is 750 °C. It is shown that increased methane conversion is observed at the feed space velocity of methane decreasing from 1500 to 500 h-1.

  19. The effects of heavy metals and their interactions with polycyclic aromatic hydrocarbons on the oxidative stress among coke-oven workers

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Tian; Feng, Wei; Kuang, Dan; Deng, Qifei [Department of Occupational and Environmental Health, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Zhang, Wangzhen [Institute of Industrial Health, Wuhan Iron & Steel (Group) Corporation, Wuhan 430070, China. (China); Wang, Suhan; He, Meian; Zhang, Xiaomin; Wu, Tangchun [Department of Occupational and Environmental Health, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Guo, Huan, E-mail: ghuan5011@hust.edu.cn [Department of Occupational and Environmental Health, State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China)

    2015-07-15

    Heavy metals and polycyclic aromatic hydrocarbons (PAHs) are predominate toxic constituents of particulate air pollution that may be related to the increased risk of cardiopulmonary events. We aim to investigate the effects of the toxic heavy metals (arsenic, As; cadmium, Cd; chromium, Cr; nickel, Ni; and lead, Pb), and their interactions with PAHs on oxidative stress among coke-oven workers. A total of 1333 male workers were recruited in this study. We determined their urinary levels of As, Cd, Cr, Ni, Pb, twelve PAH metabolites, 8-hydroxydeoxyguanosine (8-OHdG), and 8-iso-prostaglandin-F2α (8-iso-PGF2α). Multivariate linear regression models were used to analyze the effects of these metals and their interactions with PAHs on 8-OHdG and 8-iso-PGF2α levels. It was found that only urinary As and Ni showed marginal or significant positive linear dose-dependent effects on 8-OHdG in this study population, especially among smokers (β=0.103, P=0.073 and β=0.110, P=0.002, respectively). After stratifying all participants by the quartiles of ΣOH-PAH, all five metals showed linear association with 8-OHdG in the highest quartile subgroup (Q4) of ΣOH-PAHs. However, these five urinary metals showed significantly consistent linear associations with 8-iso-PGF2α in all subjects and each stratum. Urinary ΣOH-PAHs can significant modify the effects of heavy metals on oxidative stress, while co-exposure to both high levels of ΣOH-PAHs and heavy metals render the workers with highest 8-OHdG and 8-iso-PGF2α (all P{sub interaction}≤0.005). This study showed evidence on the interaction effects of heavy metals and PAHs on increasing the oxidative stress, and these results warrant further investigation in more longitudinal studies. - Highlights: • Heavy metals and PAHs are predominate toxic constituents of particulate matters. • Urinary As and Ni showed linear dose-dependent effects on 8-OHdG and 8-iso-PGF2α. • PAHs significant interact with toxic metal in increasing 8

  20. Co-exposure to polycyclic aromatic hydrocarbons, benzene and toluene and their dose-effects on oxidative stress damage in kindergarten-aged children in Guangzhou, China.

    Science.gov (United States)

    Li, Junnan; Lu, Shaoyou; Liu, Guihua; Zhou, Yuanxiu; Lv, Yanshan; She, Jianwen; Fan, Ruifang

    2015-08-15

    Polycyclic aromatic hydrocarbons (PAHs), benzene and toluene (BT) are ubiquitous toxic pollutants in the environment. Children are sensitive and susceptible to exposure to these contaminants. To investigate the potential oxidative DNA damage from the co-exposure of PAHs and BT in children, 87 children (aged 3-6) from a kindergarten in Guangzhou, China, were recruited. Ten urinary PAHs and four BT metabolites, as well as 8-hydroxy-2'-deoxyguanosine (8-OHdG, a biomarker of oxidative DNA damage)in urine, were determined using a liquid chromatography tandem mass spectrometer. The results demonstrated that the levels of PAHs and BT in children from Guangzhou were 2-30 times higher than those in children from the other countries based on a comparison with recent data from the literature. In particular, the difference is more substantial for pyrene and volatile BT. Co-exposure to PAHs and BT could lead to additive oxidative DNA damage. Significant dose-effects were observed between the sum concentration of urinary monohydroxylated metabolites of PAHs (∑OH-PAHs), the sum concentration of the metabolites of BT (∑BT) and 8-OHdG levels. Every one percent increase in urinary PAHs and BT generated 0.33% and 0.02% increases in urinary 8-OHdG, respectively. We also determined that the urinary levels of PAHs and BT were negatively associated with the age of the children. Moreover, significant differences in the levels of ∑OH-PAHs and ∑BT were determined between 3- and 6-year-old children (p<0.05), which may be caused by different metabolism capabilities or inhalation frequencies. In conclusion, exposure to PAHs or BT could lead to oxidative DNA damage, and 8-OHdG is a good biomarker for indicating the presence of DNA damage. There exists a significant dose-effect relationship between PAH exposure, BT exposure and the concentration of 8-OHdG in urine. Toddlers (3-4 years old) face a higher burden of PAH and BT exposure compared with older children.

  1. Dioxygen oxidation of hydrocarbons by a methane monooxygenase-like system: diiron complex-O2-Zn/HOAc-MV2+

    Institute of Scientific and Technical Information of China (English)

    魏俊发; 何地平; 俞贤达

    1999-01-01

    The activation of dioxygen and incorporation into hydrocarbons have been achieved under mild conditions by a methane monooxygenase (MMO)-like system using a dinuclear iron complex [Fe2Dhist(OAc)2]BPh4·3H2O as the model complex, zinc powder as the electron donor, HOAc as the proton source and methylviologen as the electron transfer agent. The results show that styrene is oxygenated predominantly to styrene oxide (1 396 mol/100 mol of the Fe2 complex), benzaldehyde (16160) and acetophenone (986), and cyclohexane to cyclohexanol (9370) and cyclohexanone (2670). EPR studies indicate that the hypervalent ironoxo spiecs FeⅣFeⅣ(?)O, derived from FeⅢFeⅢ core via reduction, O2-binding and protonation, is the active intermediate which inserts the activated oxygen atom into C(?)C or C—H bond giving each product. The system closely resembles MMO and its close relative hemerythrin in the aspects of reaction phenomena, EPR characteristics and product distributions. The Mn2 analog cmplex、Fe-Zn hetero

  2. An evaluation of the use of an advanced oxidation process to remove chlorinated hydrocarbons from groundwater at the US Department of Energy Kansas City Plant

    Energy Technology Data Exchange (ETDEWEB)

    Garland, S.B. II; Peyton, G.R.

    1990-10-01

    The Allied-Signal Aerospace Company currently operates a production facility in Kansas City, Missouri, under contract with the US Department of Energy (DOE). Over the years the operation of the DOE Kansas City Plant has resulted in the contamination of groundwater with chlorinated hydrocarbons, including trichloroethene (TCE). One of the plumes of contaminated groundwater, the underground tank farm (UTF) plume, was selected for remediation with an advanced oxidation process (AOP) consisting of simultaneous treatment by ozone (O{sub 3}), ultraviolet (UV) radiation, and hydrogen peroxide (H{sub 2}O{sub 2}). Since the use of AOPs is relatively new for the removal of organics from groundwater, information on design criteria, costs, performance, and operating experience is not well documented in the literature. Therefore, the Oak Ridge National Laboratory (ORNL) was requested to evaluate the treatment process. This report documents the work performed through FY 1989. The results of the initial year of the evaluations, FY 1988, have been published previously, and the evaluation will continue at least through FY 1990. This report first briefly describes the treatment plant and the mechanisms of the treatment process. Next, the methodology and the results from the evaluation are discussed. Finally, conclusions and recommendations are presented. 8 refs., 14 figs., 16 tabs.

  3. [Identification of Hydrocarbon-Oxidizing Dietzia Bacteria from Petroleum Reservoirs Based on Phenotypic Properties and Analysis of the 16S rRNA and gyrB Genes].

    Science.gov (United States)

    Nazina, T N; Shumkova, E S; Sokolova, D Sh; Babich, T L; Zhurina, M V; Xue, Yan-Fen; Osipov, G A; Poltaraus, A B; Tourova, T P

    2015-01-01

    The taxonomic position of hydrocarbon-oxidizing bacterial strains 263 and 32d isolated from formation water of the Daqing petroleum reservoir (PRC) was determined by polyphasic taxonomy techniques, including analysis of the 16S rRNA and the gyrB genes. The major chemotaxonomic characteristics of both strains, including the IV type cell wall, composition of cell wall fatty acids, mycolic acids, and menaquinones, agreed with those typical of Dietzia strains. The DNA G+C content of strains 263 and 32d were 67.8 and 67.6 mol%, respectively. Phylogenetic analysis of the 16S rRNA gene of strain 32d revealed 99.7% similarity to the gene of D. maris, making it possible to identify strain 32d as belonging to this species. The 16S rRNA gene sequence of strain 263 exhibited 99.7 and 99.9% similarity to those of D. natronolimnaea and D. cercidiphylli YIM65002(T), respectively. Analysis of the gyrB genes of the subterranean isolates and of a number of Dietzia type strains confirmed classiffication of strain 32d as a D. maris strain and of strain 263, as a D. natronolimnaea strain. A conclusion was made concerning higher resolving power of phylogenetic analysis of the gyrB gene compared to the 16S rRNA gene analysis in the case of determination of the species position of Dietzia isolates.

  4. Diphenylarsinic acid, a chemical warfare-related neurotoxicant, promotes liver carcinogenesis via activation of aryl hydrocarbon receptor signaling and consequent induction of oxidative DNA damage in rats.

    Science.gov (United States)

    Wei, Min; Yamada, Takanori; Yamano, Shotaro; Kato, Minoru; Kakehashi, Anna; Fujioka, Masaki; Tago, Yoshiyuki; Kitano, Mistuaki; Wanibuchi, Hideki

    2013-11-15

    Diphenylarsinic acid (DPAA), a chemical warfare-related neurotoxic organic arsenical, is present in the groundwater and soil in some regions of Japan due to illegal dumping after World War II. Inorganic arsenic is carcinogenic in humans and its organic arsenic metabolites are carcinogenic in animal studies, raising serious concerns about the carcinogenicity of DPAA. However, the carcinogenic potential of DPAA has not yet been evaluated. In the present study we found that DPAA significantly enhanced the development of diethylnitrosamine-induced preneoplastic lesions in the liver in a medium-term rat liver carcinogenesis assay. Evaluation of the expression of cytochrome P450 (CYP) enzymes in the liver revealed that DPAA induced the expression of CYP1B1, but not any other CYP1, CYP2, or CYP3 enzymes, suggesting that CYP1B1 might be the enzyme responsible for the metabolic activation of DPAA. We also found increased oxidative DNA damage, possibly due to elevated CYP1B1 expression. Induction of CYP1B1 has generally been linked with the activation of AhR, and we found that DPAA activates the aryl hydrocarbon receptor (AhR). Importantly, the promotion effect of DPAA was observed only at a dose that activated the AhR, suggesting that activation of AhR and consequent induction of AhR target genes and oxidative DNA damage plays a vital role in the promotion effects of DPAA. The present study provides, for the first time, evidence regarding the carcinogenicity of DPAA and indicates the necessity of comprehensive evaluation of its carcinogenic potential using long-term carcinogenicity studies.

  5. Numerical simulation of in-situ chemical oxidation (ISCO) and biodegradation of petroleum hydrocarbons using a coupled model for bio-geochemical reactive transport

    Science.gov (United States)

    Marin, I. S.; Molson, J. W.

    2013-05-01

    Petroleum hydrocarbons (PHCs) are a major source of groundwater contamination, being a worldwide and well-known problem. Formed by a complex mixture of hundreds of organic compounds (including BTEX - benzene, toluene, ethylbenzene and xylenes), many of which are toxic and persistent in the subsurface and are capable of creating a serious risk to human health. Several remediation technologies can be used to clean-up PHC contamination. In-situ chemical oxidation (ISCO) and intrinsic bioremediation (IBR) are two promising techniques that can be applied in this case. However, the interaction of these processes with the background aquifer geochemistry and the design of an efficient treatment presents a challenge. Here we show the development and application of BIONAPL/Phreeqc, a modeling tool capable of simulating groundwater flow, contaminant transport with coupled biological and geochemical processes in porous or fractured porous media. BIONAPL/Phreeqc is based on the well-tested BIONAPL/3D model, using a powerful finite element simulation engine, capable of simulating non-aqueous phase liquid (NAPL) dissolution, density-dependent advective-dispersive transport, and solving the geochemical and kinetic processes with the library Phreeqc. To validate the model, we compared BIONAPL/Phreeqc with results from the literature for different biodegradation processes and different geometries, with good agreement. We then used the model to simulate the behavior of sodium persulfate (NaS2O8) as an oxidant for BTEX degradation, coupled with sequential biodegradation in a 2D case and to evaluate the effect of inorganic geochemistry reactions. The results show the advantages of a treatment train remediation scheme based on ISCO and IBR. The numerical performance and stability of the integrated BIONAPL/Phreeqc model was also verified.

  6. Observations of elevated formaldehyde over a forest canopy suggest missing sources from rapid oxidation of arboreal hydrocarbons

    Directory of Open Access Journals (Sweden)

    W. Choi

    2010-09-01

    Full Text Available To better understand the processing of biogenic VOCs (BVOCs in the pine forests of the US Sierra Nevada, we measured HCHO at Blodgett Research Station using Quantum Cascade Laser Spectroscopy (QCLS during the Biosphere Effects on Aerosols and Photochemistry Experiment (BEARPEX of late summer 2007. Four days of the experiment exhibited particularly copious HCHO, with midday peaks between 15–20 ppbv, while the other days developed delayed maxima between 8–14 ppbv in the early evening. From the expansive photochemical data set, we attempt to explain the observed HCHO concentrations by quantifying the various known photochemical production and loss terms in its chemical budget. Overall, known chemistry predicts a factor of 3–5 times less HCHO than observed. By examining diurnal patterns of the various budget terms we conclude that, during the high HCHO period, local, highly reactive oxidation chemistry produces an abundance of formaldehyde at the site. The results support the hypothesis of previous work at Blodgett Forest suggesting that large quantities of oxidation products, observed directly above the ponderosa pine canopy, are evidence of profuse emissions of very reactive volatile organic compounds (VR-VOCs from the forest. However, on the majority of days, under generally cooler and more moist conditions, lower levels of HCHO develop primarily influenced by the influx of precursors transported into the region along with the Sacramento plume.

  7. Observations of elevated formaldehyde over a forest canopy suggest missing sources from rapid oxidation of arboreal hydrocarbons

    Directory of Open Access Journals (Sweden)

    W. Choi

    2010-04-01

    Full Text Available To better understand the processing of biogenic VOCs (BVOCs in the pine forests of the U.S. Sierra Nevada, we measured HCHO at Blodgett Research Station using Quantum Cascade Laser Spectroscopy (QCLS during the Biosphere Effects on Aerosols and Photochemistry Experiment (BEARPEX of late summer 2007. Four days of the experiment exhibited particularly copious HCHO, with midday peaks between 15–20 ppbv, while the other days developed delayed maxima between 8–14 ppbv in the early evening. From the expansive photochemical data set, we attempt to explain the observed HCHO concentrations by quantifying the various known photochemical production and loss terms in its chemical budget. Overall, known chemistry predicts a factor of 3–5 times less HCHO than observed. By examining diurnal patterns of the various budget terms we conclude that, during the high HCHO period, local, highly reactive oxidation chemistry produces an abundance of formaldehyde at the site. The results support the hypothesis of previous work at Blodgett Forest suggesting that large quantities of BVOC oxidation products, observed directly above the ponderosa pine canopy, are evidence of profuse emissions of very reactive volatile organic compounds (VR-VOCs from the forest. However, on the majority of days, under generally cooler and more moist conditions, lower levels of HCHO develop primarily influenced by the influx of precursors transported into the region along with the Sacramento plume.

  8. 氟碳杂化表面活性剂的研究进展%Research Progress of Fluorocarbon-hydrocarbon Hybrid Surfactants

    Institute of Scientific and Technical Information of China (English)

    刘刚芝; 冯浦涌; 荣新明; 费晨洪; 王碧清; 王继宇; 冯玉军

    2013-01-01

    氟碳杂化表面活性剂是指分子结构中同时含有氟碳链和碳氢链的表面活性剂.从氟碳杂化表面活性剂的类型,合成路线,溶液性能及应用等方面系统地综述了其研究进展.参考文献46篇.%Fluorocarbon-hydrocarbon hybrid surfactants are amphiphilies in which fluorocarbon and hydrocarbon chains coexist.In this paper,the classification,synthesis,surface activities and application of fluorocarbon-hydrocarbon hybrid surfactants are reviewed with 46 references.

  9. Supported manganese oxide on TiO{sub 2} for total oxidation of toluene and polycyclic aromatic hydrocarbons (PAHs): Characterization and catalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Aboukaïs, Antoine, E-mail: aboukais@univ-littoral.fr [Univ Lille Nord de France, 59000 Lille (France); Equipe Catalyse, UCEIV, EA 4492, MREI, ULCO, 59140 Dunkerque (France); Abi-Aad, Edmond [Univ Lille Nord de France, 59000 Lille (France); Equipe Catalyse, UCEIV, EA 4492, MREI, ULCO, 59140 Dunkerque (France); Taouk, Bechara [Laboratoire de Sécurité des procédés Chimiques (LSPC), EA 4704, INSA Rouen, Avenue de l' Université, 76801 Saint Etienne du Rouvray (France)

    2013-11-01

    Manganese oxide catalysts supported on titania (TiO{sub 2}) were prepared by incipient wetness impregnation method in order to elaborate catalysts for total oxidation of toluene and PAHs. These catalysts have been characterized by means of X-ray diffraction (XRD), electron paramagnetic resonance (EPR), temperature programmed reduction (TPR) and temperature programmed desorption (TPD). It has been shown that for the 5%Mn/TiO{sub 2} catalyst the reducibility and the mobility of oxygen are higher compared, in one side, to other x%Mn/TiO{sub 2} samples and, in another side, to catalysts where TiO{sub 2} support was replaced by γ-Al{sub 2}O{sub 3} or SiO{sub 2}. It has been shown that the content of manganese loading on TiO{sub 2} has an effect on the catalytic activity in the toluene oxidation. A maximum of activity was obtained for the 5%Mn/TiO{sub 2} catalyst where the total conversion of toluene was reached at 340 °C. This activity seems to be correlated to the presence of the Mn{sup 3+}/Mn{sup 4+} redox couple in the catalyst. When the Mn content increases, large particles of Mn{sub 2}O{sub 3} appear leading then to the decrease in the corresponding activity. In addition, compared to both other supports, TiO{sub 2} seems to be the best to give the best catalytic activity for the oxidation of toluene when it is loaded with 5% of manganese. For this reason, the latter catalyst was tested for the abatement of some PAHs. The light off temperature of PAHs compounds increases with increasing of benzene rings number and with decreasing of H/C ratio. All of PAHs are almost completely oxidized and converted at temperatures lower than 500 °C. - Highlights: • Preparation of x%MnO{sub 2}/TiO{sub 2} catalysts. • Catalytic oxidation tests of toluene and PAHs. • EPR, TPR and TPD characterizations of Mn(II) and Mn(IV) ions.

  10. 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.

  11. 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.

  12. Highly efficient visible light photocatalytic reduction of CO2 to hydrocarbon fuels by Cu-nanoparticle decorated graphene oxide.

    Science.gov (United States)

    Shown, Indrajit; Hsu, Hsin-Cheng; Chang, Yu-Chung; Lin, Chang-Hui; Roy, Pradip Kumar; Ganguly, Abhijit; Wang, Chen-Hao; Chang, Jan-Kai; Wu, Chih-I; Chen, Li-Chyong; Chen, Kuei-Hsien

    2014-11-12

    The production of renewable solar fuel through CO2 photoreduction, namely artificial photosynthesis, has gained tremendous attention in recent times due to the limited availability of fossil-fuel resources and global climate change caused by rising anthropogenic CO2 in the atmosphere. In this study, graphene oxide (GO) decorated with copper nanoparticles (Cu-NPs), hereafter referred to as Cu/GO, has been used to enhance photocatalytic CO2 reduction under visible-light. A rapid one-pot microwave process was used to prepare the Cu/GO hybrids with various Cu contents. The attributes of metallic copper nanoparticles (∼4-5 nm in size) in the GO hybrid are shown to significantly enhance the photocatalytic activity of GO, primarily through the suppression of electron-hole pair recombination, further reduction of GO's bandgap, and modification of its work function. X-ray photoemission spectroscopy studies indicate a charge transfer from GO to Cu. A strong interaction is observed between the metal content of the Cu/GO hybrids and the rates of formation and selectivity of the products. A factor of greater than 60 times enhancement in CO2 to fuel catalytic efficiency has been demonstrated using Cu/GO-2 (10 wt % Cu) compared with that using pristine GO.

  13. Selective Synthesis of Gasoline-Ranged Hydrocarbons from Syngas over Hybrid Catalyst Consisting of Metal-Loaded ZSM-5 Coupled with Copper-Zinc Oxide

    Directory of Open Access Journals (Sweden)

    Ting Ma

    2014-04-01

    Full Text Available The conversion of syngas (CO + H2 to gasoline-ranged hydrocarbons was carried out using a hybrid catalyst consisting of metal-loaded ZSM-5 coupled with Cu-ZnO in a near-critical n-hexane solvent. Methanol was synthesized from syngas over Cu-ZnO; subsequently, was converted to hydrocarbons through the formation of dimethyl ether (DME over the metal-loaded ZSM-5. When 0.5 wt% Pd/ZSM-5 and 5 wt% Cu/ZSM-5 among the metal-loaded ZSM-5 catalysts with Pd, Co, Fe or Cu were employed as a portion of the hybrid catalyst, the gasoline-ranged hydrocarbons were selectively produced (the gasoline-ranged hydrocarbons in all hydrocarbons: 59% for the hybrid catalyst with Pd/ZSM-5 and 64% for that with Cu/ZSM-5 with a similar CO conversion during the reaction. An increase in the Cu loading on ZSM-5 resulted in increasing the yield of the gasoline-ranged hydrocarbons, and in decreasing the yield of DME. Furthermore, the hybrid catalyst with Cu/ZSM-5 exhibited no deactivation for 30 h of the reaction. It was revealed that a hybrid catalyst containing Cu/ZSM-5 was efficient in the selective synthesis of gasoline-ranged hydrocarbons from syngas via methanol in the near-critical n-hexane fluid.

  14. TiO{sub 2} on magnesium silicate monolith: effects of different preparation techniques on the photocatalytic oxidation of chlorinated hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Cardona, Ana I.; Candal, Roberto; Sanchez, Benigno; Avila, Pedro; Rebollar, Moises

    2004-05-01

    In this article, the comparative results of the photocatalytic oxidation of trichloroethylene (TCE) alone and a mixture of chlorinated hydrocarbons (trichloroethylene, perchloroethylene and chloroform) in gas phase, obtained with three different monolithic catalysts in a flat reactor frontally illuminated with a Xenon lamp are presented. The three catalysts incorporate titanium dioxide (TiO{sub 2}) as active phase on a magnesium silicate support, by means of different procedures: (i) incorporation of commercial TiO{sub 2} powder into the silicate matrix ('massic monolith'); (ii) sol-gel coating of the silicate support; (iii) impregnation with a commercial TiO{sub 2} aqueous suspension of the same silicate support. In the first case, the massic monolith was made from a 50:50 w/w mixture of magnesium silicate and 'Titafrance G5' TiO{sub 2} powder. In the second case, a magnesium silicate monolith was coated with several layers of an aqueous TiO{sub 2} sol prepared from hydrolysis and condensation of titanium tetra-isopropoxide (Ti(OC{sub 3}H{sub 7}){sub 4}) in excess of acidified water (acid catalysis). The third catalyst was prepared by impregnating the same silicate support with several layers of 'Titafrance G5' TiO{sub 2} powder water suspension. All the catalysts were thermal treated under comparable conditions in order to fix the TiO{sub 2} active phase to the silicate support. Although the performance of the massic monolith was better than the sol-gel monolith, the latter is of great interest because this technique allows the chemical composition of the active films to be easily modified.

  15. 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。

  16. 拓扑指数在烃类化合物定量构效关系中的研究进展%Research Progress of Topological Index in QSPR Study of Hydrocarbon Compounds

    Institute of Scientific and Technical Information of China (English)

    侯恩卿; 谢占川; 李秀庆; 杨林

    2011-01-01

    拓扑指数是一种重要的分子结构数学描述符,在烃类化合物的定量构效关系(QSPR)研究中占有重要作用.本文主要从烃类化合物的物理化学性质、热力学性质和色谱保留指数三个方面,综述了近年来分子拓扑指数在烷烃、烯烃、炔烃、卤代烃中的定量构效关系的研究进展.%The topological index is an important mathematical descriptors of molecular structure,plays an important role in the quantitative structure property relationship(QSPR) study of hydrocarbon compounds.This article reviewed the research progress of QSPR study about the properties of hydrocarbon compounds,such as physicochemical properties,thermodynamic properties and chromatographic retention indices by using topological index.

  17. Facile and tunable fabrication of Fe3O4/graphene oxide nanocomposites and their application in the magnetic solid-phase extraction of polycyclic aromatic hydrocarbons from environmental water samples.

    Science.gov (United States)

    Han, Qiang; Wang, Zonghua; Xia, Jianfei; Chen, Sha; Zhang, Xiaoqiong; Ding, Mingyu

    2012-11-15

    An electrostatic self-assembly approach was employed to prepare Fe(3)O(4)/graphene oxide nanocomposites, and their application in the magnetic solid-phase extraction of polycyclic aromatic hydrocarbons from environmental samples was investigated. With the highly hydrophilic graphene oxide sheets and positively charged surface of the Fe(3)O(4) nanoparticles, the nanocomposites were synthesized through electrostatic interaction in aqueous solution. Simultaneously, the different loading amounts of Fe(3)O(4) onto the graphene oxide were easily controlled by changing the proportion of the initial precursors. The identity of the hybrid materials was confirmed using transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and a vibrating sample magnetometer. Five polycyclic aromatic hydrocarbons were selected as model analytes to validate the extraction performance of the Fe(3)O(4)/GO nanocomposite as a MSPE sorbent. The excellent adsorption property was attributed to the dominant roles of π-π stacking interaction and hydrophobic interaction. After optimizing the conditions, the results indicated that the recoveries of these compounds were in the range of 76.8-103.2%, with relative standard deviations ranging between 1.7% and 11.7%; the limits of detection were in the range of 0.09-0.19 ng mL(-1).

  18. Progressive oxidation of pyrite in five bituminous coal samples: An As XANES and 57Fe Mössbauer spectroscopic study

    Science.gov (United States)

    Kolker, Allan; Huggins, Frank E.

    2007-01-01

    Naturally occurring pyrite commonly contains minor substituted metals and metalloids (As, Se, Hg, Cu, Ni, etc.) that can be released to the environment as a result of its weathering. Arsenic, often the most abundant minor constituent in pyrite, is a sensitive monitor of progressive pyrite oxidation in coal. To test the effect of pyrite composition and environmental parameters on the rate and extent of pyrite oxidation in coal, splits of five bituminous coal samples having differing amounts of pyrite and extents of As substitution in the pyrite, were exposed to a range of simulated weathering conditions over a period of 17 months. Samples investigated include a Springfield coal from Indiana (whole coal pyritic S = 2.13 wt.%; As in pyrite = detection limit (d.l.) to 0.06 wt.%), two Pittsburgh coal samples from West Virginia (pyritic S = 1.32–1.58 wt.%; As in pyrite = d.l. to 0.34 wt.%), and two samples from the Warrior Basin, Alabama (pyritic S = 0.26–0.27 wt.%; As in pyrite = d.l. to 2.72 wt.%). Samples were collected from active mine faces, and expected differences in the concentration of As in pyrite were confirmed by electron microprobe analysis. Experimental weathering conditions in test chambers were maintained as follows: (1) dry Ar atmosphere; (2) dry O2 atmosphere; (3) room atmosphere (relative humidity ∼20–60%); and (4) room atmosphere with samples wetted periodically with double-distilled water. Sample splits were removed after one month, nine months, and 17 months to monitor the extent of As and Fe oxidation using As X-ray absorption near-edge structure (XANES) spectroscopy and 57Fe Mössbauer spectroscopy, respectively. Arsenic XANES spectroscopy shows progressive oxidation of pyritic As to arsenate, with wetted samples showing the most rapid oxidation. 57Fe Mössbauer spectroscopy also shows a much greater proportion of Fe3+ forms (jarosite, Fe3+ sulfate, FeOOH) for samples stored under wet conditions, but much less

  19. In situ Fourier transform-infrared internal reflection spectroscopic analysis of hydrocarbon chain ordering of surfactants adsorbed at mineral oxide surfaces

    Science.gov (United States)

    Cross, William Murray

    The adsorption of surfactants at mineral oxide surfaces was investigated by in situ Fourier transform infrared internal reflection spectroscopy (FT-IR/IRS), and contact angle goniometry. FT-IR/IRS was used to determine both adsorption isotherms and the enthalpy of adsorption. Furthermore, the conformation and orientation of the hydrocarbon chain of SDS adsorbed at a sapphire internal reflection element (IRE) were determined. Contact angle goniometry was used to measure the effect of the surface phase of the surfactant on the hydrophobic character of sapphire surfaces in aqueous solutions. For SDS adsorbed by sapphire, in situ FT-IR/IRS experiments indicate that a surface phase transition occurs at an adsorption density of 2 to 3 x 10-10 mol/cm2 for both pD 2.9 and 6.9. This transition is characterized by a two to four wavenumber shift in the position of the asymmetric -CH2 stretching band. Based on solution spectroscopy studies, the surface phase was found to be similar to solution phase micelles and liquid crystals for adsorption densities less than the adsorption density of the surface phase transition. Whereas for adsorption densities in excess of the adsorption density of the surface phase transition, the surface phase resembled a solution phase coagel species. It was also found that the contact angle of an air bubble at the sapphire surface exhibited a sharp decrease at the adsorption density corresponding to the surface phase transition The effect of temperature on adsorption and phase behavior of SDS at the sapphire IRE surface was also determined. It was shown that a surface phase transition similar to that discussed occurred at approximately 298 K. The adsorption reaction was found to be exothermic, with a heat of adsorption of --1.3 kcal/mole for adsorption densities less than the adsorption density of the surface phase transition at 298 K and --4.1 kcal/mole for adsorption densities greater than the adsorption density of the surface phase transition

  20. Progress of the Application of Mesoporous Silica-Supported Heteropolyacids in Heterogeneous Catalysis and Preparation of Nanostructured Metal Oxides

    Directory of Open Access Journals (Sweden)

    Heyong He

    2010-01-01

    Full Text Available Mesoporous silica molecular sieves are a kind of unique catalyst support due to their large pore size and high surface area. Several methods have been developed to immobilize heteropolyacids (HPAs inside the channels of these mesoporous silicas. The mesoporous silica-supported HPA materials have been widely used as recyclable catalysts in heterogeneous systems. They have shown high catalytic activities and shape selectivities in some reactions, compared to the parent HPAs in homogeneous systems. This review summarizes recent progress in the field of mesoporous silica-supported HPAs applied in the heterogeneous catalysis area and preparation of nanostructured metal oxides using HPAs as precursors and mesoporous silicas as hard templates.

  1. Hydrocarbon-oil encapsulated bubble flotation of fine coal using 3-in. ID flotation column. Technical progress report for the eleventh quarter, April 1--June 30, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Peng, F.F.

    1996-05-01

    There are four modes of the collector dispersion techniques. They are (1) direct liquid additions and stirring, (2) ultrasonic energy collector dispersion, (3) atomized collector dispersion, and (4) gasified collector transported in air stream. Among those collector dispersion techniques, the technique using the gasified collector transported in air phase can be used to enhance the flotation performance with substantial reduction in collector usage and selectivity, compared to the flotation using direct liquid addition (and mechanical agitation) technique. In this phase of study, two modes of collector addition techniques including gasified collector transported in gas phase and direct collector addition techniques were applied in the column flotation to demonstrate the selectivity of utilizing the hydrocarbon-oil encapsulated air bubbles in the fine coal flotation process. The 1-in. ID flotation column was used to scale-up to 3-in. ID flotation column. The initial starting point to operate the 3-in ID flotation column were determined using both 1-in. and 3-in. flotation columns based on the three phases of work plans and experiment design. A 3-in. flotation column was used to evaluate two modes of collector dispersion and addition techniques on the recovery and grade of fine coals using various ranks of coal.

  2. Recent Progress in Nanostructured Oxide TE Materials for Power Generation at High Temperatures

    DEFF Research Database (Denmark)

    Van Nong, Ngo; Pryds, Nini; Linderoth, Søren

    Thermoelectric (TE) materials, which can convert waste heat into electricity, could play an important role in a global sustainable energy solution and environmental problems. Metal oxides have been considered as potential TE materials for power generation that can operate at high temperatures on ......σT/κ , where S, σ, T and κ are the Seebeck coefficient, electrical conductivity, absolute temperature and thermal conductivity, respectively). We have fabricated high-quality oxide TE materials based on Ca3Co4O9 by optimizing the method for synthesis, modifying the compositions...

  3. A resistant starch fiber diet ameliorates oxidative stress, inflammation, and progression of chronic kidney disease (CKD)

    Science.gov (United States)

    Inflammation is a constant feature and a major mediator of CKD progression. It is, in part, driven by altered gut microbiome and disruption of intestinal epithelial barrier, events which are primarily caused by: 1- urea influx in the intestine resulting in dominance of urease-possessing bacteria; 2-...

  4. High amylose resistant starch diet ameliorates oxidative stress, inflammation, and progression of chronic kidney disease

    Science.gov (United States)

    Inflammation is a major mediator of CKD progression and is partly driven by altered gut microbiome and intestinal barrier disruption, events which are caused by: urea influx in the intestine resulting in dominance of urease-possessing bacteria; disruption of epithelial barrier by urea-derived ammoni...

  5. Selective Synthesis of Gasoline-Ranged Hydrocarbons from Syngas over Hybrid Catalyst Consisting of Metal-Loaded ZSM-5 Coupled with Copper-Zinc Oxide

    National Research Council Canada - National Science Library

    Ting Ma; Hiroyuki Imai; Manami Yamawaki; Kazusa Terasaka; Xiaohong Li

    2014-01-01

      The conversion of syngas (CO + H2) to gasoline-ranged hydrocarbons was carried out using a hybrid catalyst consisting of metal-loaded ZSM-5 coupled with Cu-ZnO in a near-critical n-hexane solvent...

  6. 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...

  7. 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.

  8. 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.

  9. 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.

  10. Progress in the research and development of p-xylene liquid phase oxidation process

    Institute of Scientific and Technical Information of China (English)

    WANG Lijun; CHENG Youwei; WANG Qinbo; LI Xi

    2007-01-01

    The process of p-xylene liquid phase oxidation to produce purified terephthalic acid (PTA) involves a series of liquid phase radical reactions,chemical absorption,reactive crystallization,and evaporation.A commercial PTA production flow sheet includes a number of unit operations,which construct a complex process system.In this paper,a review of research and development (R & D) works on PTA process carried out in Zhejiang University during recent years is introduced.The works cover the oxidation and crystallization kinetics,gas-liquid mass transfer and evaporation,reactor modeling,database development,novel reactor design,process modeling,simulation,and optimization.The author emphasizes the viewpoint through this case study that chemical reaction engineering should be developed to process system engineering to extend its scope,and particular attention should be paid on reactor and process modeling.

  11. Human oxidation-specific antibodies reduce foam cell formation and atherosclerosis progression

    DEFF Research Database (Denmark)

    Tsimikas, Sotirios; Miyanohara, Atsushi; Hartvigsen, Karsten

    2011-01-01

    We sought to assess the in vivo importance of scavenger receptor (SR)-mediated uptake of oxidized low-density lipoprotein (OxLDL) in atherogenesis and to test the efficacy of human antibody IK17-Fab or IK17 single-chain Fv fragment (IK17-scFv), which lacks immunologic properties of intact antibod...... antibodies other than the ability to inhibit uptake of OxLDL by macrophages, to inhibit atherosclerosis....

  12. Metal-Organic Framework-Derived Nanoporous Metal Oxides toward Supercapacitor Applications: Progress and Prospects.

    Science.gov (United States)

    Salunkhe, Rahul R; Kaneti, Yusuf V; Yamauchi, Yusuke

    2017-06-27

    Transition metal oxides (TMOs) have attracted significant attention for energy storage applications such as supercapacitors due to their good electrical conductivity, high electrochemical response (by providing Faradaic reactions), low manufacturing costs, and easy processability. Despite exhibiting these attractive characteristics, the practical applications of TMOs for supercapacitors are still relatively limited. This is largely due to their continuous Faradaic reactions, which can lead to major changes or destruction of their structure as well phase changes (in some cases) during cycling, leading to the degradation in their capacitive performance over time. Hence, there is an immediate need to develop new synthesis methods, which will readily provide stable porous architectures, controlled phase, as well as useful control over dimensions (1-D, 2-D, and 3-D) of the metal oxides for improving their performance in supercapacitor applications. Since its discovery in late 1990s, metal-organic frameworks (MOFs) have influenced many fields of material science. In recent years, they have gained significant attention as precursors or templates for the derivation of porous metal oxide nanostructures and nanocomposites for next-generation supercapacitor applications. Even though these materials have widespread applications and have been widely studied in terms of their structural features and synthesis, it is still not clear how these materials will play an important role in the development of the supercapacitor field. In this review, we will summarize the recent developments in the field of MOF-derived porous metal oxide nanostructures and nanocomposites for supercapacitor applications. Furthermore, the current challenges along with the future trends and prospects in the application of these materials for supercapacitors will also be discussed.

  13. Aromatics oxidation and soot formation in flames. Progress report, August 15, 1990--August 14, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J.B.; Pope, C.J.; Shandross, R.A.; Yadav, T.

    1993-04-01

    This project is concerned with the kinetics and mechanisms of aromatics oxidation and soot and fullerenes formation in flames. The scope includes detailed measurements of profiles of stable and radical species concentrations in low-pressure one-dimensional premixed flames. Intermediate species identifications and mole fractions, fluxes, and net reaction rates calculated from the measured profiles are used to test postulated reaction mechanisms. Particular objectives are to identify, and to confirm or determine rate constants for, the main benzene oxidation reactions in flames, and to characterize soot and fullerenes and their formation mechanisms and kinetics. Stable and radical species profiles in the aromatics oxidation study are measured using molecular beam sampling with on-line mass spectrometry. The rate of soot formation measured by conventional optical techniques is found to support the hypotheses that particle inception occurs through reactive coagulation of high molecular weight PAH in competition with destruction by OHattack, and that the subsequent growth of the soot mass occurs through addition reactions of PAH and C{sub 2}H{sub 2} with the soot particles. During the first year of this reporting period, fullerenes C{sub 60} and C{sub 70} in substantial quantities were found in the flames being studied. The fullerenes were recovered, purified and spectroscopically identified. The yields of C{sub 60} and C{sub 70} were then determined over ranges of conditions in low-pressure premixed flames of benzene and oxygen.

  14. Genetic, Immune-Inflammatory, and Oxidative Stress Biomarkers as Predictors for Disability and Disease Progression in Multiple Sclerosis.

    Science.gov (United States)

    Kallaur, Ana Paula; Reiche, Edna Maria Vissoci; Oliveira, Sayonara Rangel; Simão, Andrea Name Colado; Pereira, Wildea Lice de Carvalho Jennings; Alfieri, Daniela Frizon; Flauzino, Tamires; Proença, Caio de Meleck; Lozovoy, Marcell Alysson Batisti; Kaimen-Maciel, Damacio Ramón; Maes, Michael

    2017-01-01

    The aim of this study was to evaluate the TNFβ NcoI polymorphism (rs909253) and immune-inflammatory, oxidative, and nitrosative stress (IO&NS) biomarkers as predictors of disease progression in multiple sclerosis (MS). We included 212 MS patients (150 female, 62 male, mean (±standard deviation (SD)) age = 42.7 ± 13.8 years) and 249 healthy controls (177 female, 72 male, 36.8 ± 11 years). The disability was measured the Expanded Disability Status Scale (EDSS) in 2006 and 2011. We determined the TNFβ NcoI polymorphism and serum levels of interleukin (IL)-6, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, IL-4, IL-10, and IL-17, albumin, ferritin, and plasma levels of lipid hydroperoxides (CL-LOOH), carbonyl protein, advanced oxidation protein products (AOPPs), nitric oxide metabolites (NOx), and total radical-trapping antioxidant parameter (TRAP). The mean EDSS (±SD) in 2006 was 1.62 ± 2.01 and in 2011 3.16 ± 2.29, and disease duration was 7.34 ± 7.0 years. IL-10, TNF-α, IFN-γ, AOPP, and NOx levels were significantly higher and IL-4 lower in MS patients with a higher 2011 EDSS scores (≥3) as compared with those with EDSS New drugs to treat MS should also target oxidative stress pathways.

  15. Selenium, selenoenzymes, oxidative stress and risk of neoplastic progression from Barrett's esophagus: results from biomarkers and genetic variants.

    Directory of Open Access Journals (Sweden)

    Yumie Takata

    Full Text Available Clinical trials have suggested a protective effect of selenium supplementation on the risk of esophageal cancer, which may be mediated through the antioxidant activity of selenoenzymes. We investigated whether serum selenium concentrations, selenoenzyme activity, oxidative stress and genetic variation in selenoenzymes were associated with the risk of neoplastic progression to esophageal adenocarcinoma (EA and two intermediate endpoints, aneuploidy and tetraploidy. In this prospective cohort study, during an average follow-up of 7.3 years, 47 EA cases, 41 aneuploidy cases and 51 tetraploidy cases accrued among 361 participants from the Seattle Barrett's Esophagus Research Study who were free of EA at the time of blood draw and had at least one follow-up visit. Development to EA was assessed histologically and aneuploidy and tetraploidy by DNA content flow cytometry. Serum selenium concentrations were measured using atomic absorption spectrometry, activity of glutathione peroxidase (GPX 1 and GPX3 by substrate-specific coupled test procedures, selenoprotein P (SEPP1 concentrations and protein carbonyl content by ELISA method and malondialdehyde concentrations by HPLC. Genetic variants in GPX1-4 and SEPP1 were genotyped. Serum selenium was not associated with the risk of neoplastic progression to EA, aneuploidy or tetraploidy (P for trend = 0.25 to 0.85. SEPP1 concentrations were positively associated with the risk of EA [hazard ratio (HR = 3.95, 95% confidence intervals (CI = 1.42-10.97 comparing the third tertile with the first] and with aneuploidy (HR = 6.53, 95% CI = 1.31-32.58, but not selenoenzyme activity or oxidative stress markers. No genetic variants, overall, were associated with the risk of neoplastic progression to EA (global p = 0.12-0.69. Our results do not support a protective effect of selenium on risk of neoplastic progression to EA. Our study is the first to report positive associations of plasma SEPP1

  16. 2015 Progress Report/July 2016: Iron Oxide Redox Transformation Pathways: The Bulk Electrical Conduction Mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Scherer, Michelle M. [Univ. of Iowa, Iowa City, IA (United States); Rosso, Kevin M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-07-25

    Despite decades of research on the reactivity and stable isotope properties of Fe oxides, the ability to describe the redox behavior of Fe oxides in the environment is still quite limited. This is due, in large part, to the analytical and spatial complexities associated with studying microscopic processes at the Fe oxide-water interface. This project had the long-term vision of filling this gap by developing a detailed understanding of the relationship between interfacial ET processes, surface structure and charge, and mineral semiconducting properties. We focused on the Fe(III)-oxides and oxyhydroxides because of their geochemical preponderance, versatility in synthesis of compositionally, structurally, and morphologically tailored phases, and because they are amenable to a wide range of surface and bulk properties characterization. In particular, reductive transformation of phases such as hematite (α-Fe2O3) and goethite (α-FeOOH) in aqueous solution can serve as excellent model systems for studies of electron conduction processes, as well as provide valuable insights into effect of nanoscale conductive materials on contaminant fate at DOE sites. More specifically, the goal of the Iowa component of this project was to use stable Fe isotope measurements to simultaneously measure isotope specific oxidation states and concentrations of Fe at the hematite-water and goethite-water interface. This work builds on our previous work where we used an innovative combination of 57Fe Mössbauer spectroscopy and high precision isotope ratio measurements (MC-ICP-MS) to probe the dynamics of the reaction of aqueous Fe(II) with goethite. Mössbauer spectroscopy detects 57Fe only among all other Fe isotopes and we have capitalized on this to spectroscopically demonstrate Fe(II)-Fe(III) electron transfer between sorbed Fe(II) and Fe(III) oxides (Handler, et al., 2009; Gorski, et al. 2010; Rosso et al., 2010). By combining the M

  17. 2015 Progress Report/July 2016: Iron Oxide Redox Transformation Pathways: The Bulk Electrical Conduction Mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Scherer, Michelle M. [Univ. of Iowa, Iowa City, IA (United States); Rosso, Kevin M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-07-25

    Despite decades of research on the reactivity and stable isotope properties of Fe oxides, the ability to describe the redox behavior of Fe oxides in the environment is still quite limited. This is due, in large part, to the analytical and spatial complexities associated with studying microscopic processes at the Fe oxide-water interface. This project had the long-term vision of filling this gap by developing a detailed understanding of the relationship between interfacial ET processes, surface structure and charge, and mineral semiconducting properties. We focused on the Fe(III)-oxides and oxyhydroxides because of their geochemical preponderance, versatility in synthesis of compositionally, structurally, and morphologically tailored phases, and because they are amenable to a wide range of surface and bulk properties characterization. In particular, reductive transformation of phases such as hematite (α-Fe2O3) and goethite (α-FeOOH) in aqueous solution can serve as excellent model systems for studies of electron conduction processes, as well as provide valuable insights into effect of nanoscale conductive materials on contaminant fate at DOE sites. More specifically, the goal of the Iowa component of this project was to use stable Fe isotope measurements to simultaneously measure isotope specific oxidation states and concentrations of Fe at the hematite-water and goethite-water interface. This work builds on our previous work where we used an innovative combination of 57Fe Mössbauer spectroscopy and high precision isotope ratio measurements (MC-ICP-MS) to probe the dynamics of the reaction of aqueous Fe(II) with goethite. Mössbauer spectroscopy detects 57Fe only among all other Fe isotopes and we have capitalized on this to spectroscopically demonstrate Fe(II)-Fe(III) electron transfer between sorbed Fe(II) and Fe(III) oxides (Handler, et al., 2009; Gorski, et al. 2010; Rosso et al., 2010). By combining the M

  18. Recent Progress in Application of Internal Oxidation Technique in Nb3Sn Strands

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xingchen [Fermilab; Peng, Xuan [Hyper Tech Research Inc.; Sumption, Michael [Ohio State U.; Collings, E. W. [Ohio State U.

    2016-10-13

    The internal oxidation technique can generate ZrO2 nano particles in Nb3Sn strands, which markedly refine the Nb3Sn grain size and boost the high-field critical current density (Jc). This article summarizes recent efforts on implementing this technique in practical Nb3Sn wires and adding Ti as a dopant. It is demonstrated that this technique can be readily incorporated into the present Nb3Sn conductor manufacturing technology. Powder-in-tube (PIT) strands with fine subelements (~25 µm) based on this technique were successfully fabricated, and proper heat treatments for oxygen transfer were explored. Future work for producing strands ready for applications is proposed.

  19. Quarterly progress report, January 1--March 30, 1979 - Study of plutonium oxide leak rates from shipping containers.

    Energy Technology Data Exchange (ETDEWEB)

    Schwendiman, L.C.; Madia, W.J.; Mishima, J.; Sutter, S.L.; Owzarski, P.C.; Bander, T.J.; Schmidt, E.W.; Yesso, J.D.

    1979-05-01

    The study was initiated in October 1976, as outlined in the 189 research proposal submitted previously. Several tasks are to be undertaken in this study which, when combined, have the end objective of defining the leak rates of plutonium oxide powder from characterized leaks. Progress during the reporting period is briefly described on the following tasks: review of the literature and theoretical work relating to transmission of particles through channels; investigation of the relationship of gas flow rates, leak geometries, pressure and temperatures; measurement of the transmission of a well-characterized simulant (UO/sub 2/ powder) through leaks characterized in Task B; measurement of the fuel grade PuO/sub 2/ leaks through a standard leak incorporated into a suitable container; and investigation of PuO/sub 2/ leaks through simulated defected containers. (TFD)

  20. Neuromuscular electrical stimulation and dietary interventions to reduce oxidative stress in a secondary progressive multiple sclerosis patient leads to marked gains in function: a case report

    OpenAIRE

    2009-01-01

    Neuromuscular electrical stimulation has been used to aid musculoskeletal recovery. Excessive oxidative stress and excitoxicity are implicated in secondary progressive multiple sclerosis. A 52-year-old white female with SPMS had been scooter- and cane-dependent for 4 years. She requested and received a trial of neuromuscular electrical stimulation. Two months after initiating NMES the patient adopted several nutritional interventions to lower oxidative stress and excito-toxicity. During the f...

  1. Recent progress on magnetic iron oxide nanoparticles: synthesis, surface functional strategies and biomedical applications

    Science.gov (United States)

    Wu, Wei; Wu, Zhaohui; Yu, Taekyung; Jiang, Changzhong; Kim, Woo-Sik

    2015-04-01

    This review focuses on the recent development and various strategies in the preparation, microstructure, and magnetic properties of bare and surface functionalized iron oxide nanoparticles (IONPs); their corresponding biological application was also discussed. In order to implement the practical in vivo or in vitro applications, the IONPs must have combined properties of high magnetic saturation, stability, biocompatibility, and interactive functions at the surface. Moreover, the surface of IONPs could be modified by organic materials or inorganic materials, such as polymers, biomolecules, silica, metals, etc. The new functionalized strategies, problems and major challenges, along with the current directions for the synthesis, surface functionalization and bioapplication of IONPs, are considered. Finally, some future trends and the prospects in these research areas are also discussed.

  2. Mesoporous titanium oxide with high-specific surface area as a coating for in-tube solid-phase microextraction combined with high-performance liquid chromatography for the analysis of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Wang, Xiuqin; Feng, Juanjuan; Bu, Yanan; Tian, Yu; Luo, Chuannan; Sun, Min

    2017-06-01

    Stainless-steel wires coated with mesoporous titanium oxide were placed into a polyether ether ketone tube for in-tube solid-phase microextraction, and the coating sorbent was characterized by X-ray diffraction and scanning electron microscopy. It was combined with high-performance liquid chromatography to build an online system. Using eight polycyclic aromatic hydrocarbons as the analytes, some conditions including sample flow rate, sample volume, organic solvent content, and desorption time were investigated. Under optimum conditions, an online analysis method was established and provided good linearity (0.03-30 μg/L), low detection limits (0.01-0.10 μg/L), and high enrichment factors (77.6-678). The method was applied to determine target analytes in river water and water sample of coal ash, and the recoveries are in the range of 80.6-106.6 and 80.9-103.5%, respectively. Compared with estrogens and plasticizers, extraction coating shows better extraction efficiency for polycyclic aromatic hydrocarbons. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Zinc oxide/polypyrrole nanocomposite as a novel solid phase microextraction coating for extraction of aliphatic hydrocarbons from water and soil samples

    Energy Technology Data Exchange (ETDEWEB)

    Amanzadeh, Hatam; Yamini, Yadollah [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175 Tehran (Iran, Islamic Republic of); Moradi, Morteza [Department of Semiconductors, Materials and Energy Research Center, Karaj (Iran, Islamic Republic of)

    2015-07-16

    Highlights: • ZnO/polypyrrole (ZNO/PPY) nanocomposite coating was fabricated on stainless steel. • Nanocomposite coating morphology was evaluated using scanning electron microscopy. • It was applied for HS-SPME of aliphatic hydrocarbons in water and soil samples. • Separation and determination of the hydrocarbons were performed by GC-FID. • The method is suitable for routine analysis of n-alkanes in various environmental samples. - Abstract: In this work, ZnO/PPy nanocomposite coating was fabricated on stainless steel and evaluated as a novel headspace solid phase microextraction (HS-SPME) fiber coating for extraction of ultra-trace amounts of environmental pollutants; namely, aliphatic hydrocarbons in water and soil samples. The ZnO/PPy nanocomposite were prepared by a two-step process including the electrochemical deposition of PPy on the surface of stainless steel in the first step, and the synthesis of ZnO nanorods by hydrothermal process in the pores of PPy matrix in the second step. Porous structure together with ZnO nanorods with the average diameter of 70 nm were observed on the surface by using scanning electron microscopy (SEM). The effective parameters on HS-SPME of hydrocarbons (i.e., extraction temperature, extraction time, desorption temperature, desorption time, salt concentration, and stirring rate) were investigated and optimized by one-variable-at-a-time method. Under optimized conditions (extraction temperature, 65 ± 1 °C; extraction time, 15 min; desorption temperature, 250 °C; desorption time, 3 min; salt concentration, 10% w/v; and stirring rate, 1200 rpm), the limits of detection (LODs) were found in the range of 0.08–0.5 μg L{sup −1}, whereas the repeatability and fiber-to-fiber reproducibility were in the range 5.4–7.6% and 8.6–10.4%, respectively. Also, the accuracies obtained for the spiked n-alkanes were in the range of 85–108%; indicating the absence of matrix effects in the proposed HS-SPME method. The results

  4. Progress in bismuth vanadate photoanodes for use in solar water oxidation.

    Science.gov (United States)

    Park, Yiseul; McDonald, Kenneth J; Choi, Kyoung-Shin

    2013-03-21

    Harvesting energy directly from sunlight as nature accomplishes through photosynthesis is a very attractive and desirable way to solve the energy challenge. Many efforts have been made to find appropriate materials and systems that can utilize solar energy to produce chemical fuels. One of the most viable options is the construction of a photoelectrochemical cell that can reduce water to H(2) or CO(2) to carbon-based molecules. Bismuth vanadate (BiVO(4)) has recently emerged as a promising material for use as a photoanode that oxidizes water to O(2) in these cells. Significant advancement in the understanding and construction of efficient BiVO(4)-based photoanode systems has been made within a short period of time owing to various newly developed ideas and approaches. In this review, the crystal and electronic structures that are closely related to the photoelectrochemical properties of BiVO(4) are described first, and the photoelectrochemical properties and limitations of BiVO(4) are examined. Subsequently, the latest efforts toward addressing these limitations in order to improve the performances of BiVO(4)-based photoanodes are discussed. These efforts include morphology control, formation of composite structures, composition tuning, and coupling oxygen evolution catalysts. The discussions and insights provided in this review reflect the most recent approaches and directions for general photoelectrode developments and they will be directly applicable for the understanding and improvement of other photoelectrode systems.

  5. Induction of hepatic carbonyl reductase/20{beta}-hydroxysteroid dehydrogenase mRNA in rainbow trout downstream from sewage treatment works-Possible roles of aryl hydrocarbon receptor agonists and oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Albertsson, E., E-mail: eva.albertsson@zool.gu.se [Department of Zoology, University of Gothenburg, Box 463, SE-405 30 Goeteborg (Sweden); Larsson, D.G.J. [Department of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Box 434, SE-405 30 Goeteborg (Sweden); Foerlin, L. [Department of Zoology, University of Gothenburg, Box 463, SE-405 30 Goeteborg (Sweden)

    2010-05-05

    Carbonyl reductase/20{beta}-hydroxysteroid dehydrogenase (CR/20{beta}-HSD) serves both as a key enzyme in the gonadal synthesis of maturing-inducing hormone in salmonids, and as an enzyme protecting against certain reactive oxygen species. We have previously shown that mRNA of the hepatic CR/20{beta}-HSD B isoform is increased in rainbow trout caged downstream from a Swedish sewage treatment plant. Here, we report an increase of both the A as well as B form in fish kept downstream from a second sewage treatment plant. The two mRNAs were also induced in fish hepatoma cells in vitro after exposure to effluent extract. This indicates that the effects observed in vivo could be a direct effect on the liver, i.e. the mRNA induction does not require a signal from any other organ. When fish were exposed in vivo to several effluents treated with more advanced methods (ozone, moving bed biofilm reactor or membrane bioreactor) the expression of hepatic mRNA CR/20{beta}-HSD A and B was significantly reduced. Their abundance did not parallel the reduction of estrogen-responsive transcripts, in agreement with our previous observations that ethinylestradiol is not a potent inducer. Treatment with norethisterone, methyltestosterone or hydrocortisone in vivo did not induce the hepatic CR/20{beta}-HSD A and B mRNA expression. In contrast, both isoforms were markedly induced by the aryl hydrocarbon receptor agonist {beta}-naphthoflavone as well as by the pro-oxidant herbicide paraquat. We hypothesize that the induction of CR/20{beta}-HSD A and B by sewage effluents could be due to anthropogenic contaminants stimulating the aryl hydrocarbon receptor and/or causing oxidative stress.

  6. Nitric Oxide:from a mysterious labile factor to the molecule of the Nobel Prize Recent progress in nitric oxide ressarch

    Institute of Scientific and Technical Information of China (English)

    XUWEIMING; LIZHILIU

    1998-01-01

    NO is now known to be an important messenger molecule in biology.It regulates a variety of functions within cells and tissues including vasodilation,neurotransmission and immunological process.This review will focus on the nitric oxide synthase gene family and recent progress on molecular genetic analysis of NOS1,NOS2 and NOS3 genes.

  7. Draft Genome Sequence of Geobacillus subterraneus Strain K, a Hydrocarbon-Oxidizing Thermophilic Bacterium Isolated from a Petroleum Reservoir in Kazakhstan

    Science.gov (United States)

    Poltaraus, Andrey B.; Sokolova, Diyana S.; Grouzdev, Denis S.; Ivanov, Timophey M.; Malakho, Sophia G.; Korshunova, Alena V.; Tourova, Tatiyana P.

    2016-01-01

    The draft genome sequence of Geobacillus subterraneus strain K, a thermophilic aerobic oil-oxidizing bacterium isolated from production water of the Uzen high-temperature oil field in Kazakhstan, is presented here. The genome is annotated for elucidation of the genomic and phenotypic diversity of thermophilic alkane-oxidizing bacteria. PMID:27491973

  8. Effects of Pinus sylvestris root growth and mycorrhizosphere development on bacterial carbon source utilization and hydrocarbon oxidation in forest and petroleum-contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Heinonsalo, J; Haahtela, K.; Sen, R. [Helsinki Univ., Dept. of Biosciences, Helsinki (Finland); Jorgensen, K. S. [Finnish Environmental Institute, Helsinki (Finland)

    2000-05-01

    A forest ecosystem-based phytoremediation simulation project was carried out to demonstrate that pine root and mycorrhizosphere development beneficially influence bacterial community-linked carbon utilization. The process is also believed to drive a concomitant reduction of mineral oil levels in petroleum hydrocarbon (PHC)-contaminated soil. Results showed that total cell and culturable bacterial densities significantly increased in both rhizospheres and mycorrhizospheres that actively developed in the humus and PHC-contaminated soil. It was also observed that mycorrhizospheres supported the largest number of bacteria. The multivariate analysis of bacterial community carbon source utilization profiles from different rhizosphere, mycorrhizospheres, unplanted bulk soil and rhizosphere in contaminated soils highlighted three main niche-related groupings, and correspondence analysis identified amino acid preferences in rhizosphere and mycorrhizosphere compartments. Decreased levels of mineral oil were detected in PHC-contaminated soil colonized by pine root and mycorrhizal fungi, providing further confirmation of the importance of root-fungal bacterial associations in active transformations in higher molecular weight hydrocarbons in natural and contaminated soils. 61 refs., 3 tabs., 6 figs.

  9. The application of forest classification from Landsat data as a basis for natural hydrocarbon emission estimation and photochemical oxidant model simulations in southeastern Virginia

    Science.gov (United States)

    Salop, J.; Wakelyn, N. T.; Levy, G. F.; Middleton, W. M.; Gervin, J. C.

    1983-01-01

    The possible contribution by natural hydrocarbon emissions to the total ozone budget recorded in the Tidewater region of southeastern Virginia during the height of the summer period was examined. Natural sources investigated were limited to the primary HC emitters and most prevalent natural vegetation, the forests. Three types and their areal coverage were determined for Region VI of the Virginia State Air Pollution Control Board using remotely sensed data from Landsat, a NASA experimental earth resources satellite. Emission factors appropriate to the specific types (coniferous 0.24 x 10 to the 13th, mixed 0.63 x 10 to the 13th, deciduous 1.92 x 10 to the 13th, microgram/h), derived from contemporary procedures, were applied to produce an overall regional emission rate of 2.79 x 10 to the 13th microgram/h for natural non-methane hydrocarbons (NMHC). This rate was used with estimates of the anthropogenic NO(x) and NMHC loading, as input into a photochemical box model. Additional HC loading on the order of that estimated to be produced by the natural forest communities was required in order to reach certain measured summer peak ozone levels as the computer simulation was unable to account for the measured episodic levels on the basis of the anthropogenic inventory alone.

  10. Photocatalytic and chemical oxidation of organic compounds in supercritical carbon dioxide. Progress report for FY97

    Energy Technology Data Exchange (ETDEWEB)

    Blake, D.M.; Bryant, D.L.; Reinsch, V.

    1997-09-30

    disposal and using makeup scCO{sub 2}. A chemical polishing operation can reduce the release of CO{sub 2} from the process. It can also reduce the consumption of reagents that may be used in the process to enhance extraction and cleaning. A polishing operation will also reduce or avoid formation of an additional waste stream. Photocatalytic and other photochemical oxidation chemistry have not been investigated in scCO{sub 2}. The large base of information for these reactions in water, organic solvents, or air suggest that the chemistry will work in carbon dioxide. There are compelling reasons to believe that the properties of scCO{sub 2} should increase the performance of photocatalytic chemistry over that found in more conventional fluid phases.'

  11. Markers of oxidative/nitrative damage of plasma proteins correlated with EDSS and BDI scores in patients with secondary progressive multiple sclerosis.

    Science.gov (United States)

    Morel, Agnieszka; Bijak, Michał; Niwald, Marta; Miller, Elżbieta; Saluk, Joanna

    2017-05-19

    Objectives The objective of the present study was to evaluate oxidative/nitrative stress in the plasma of 50 patients suffering from the secondary progressive course of multiple sclerosis (MS), and to verify its correlation with physical and mental disability as assessed by the Expanded Disability Status Scale (EDSS), and the Beck Depression Inventory (BDI). Methods Oxidative and nitrative damage to proteins was determined by the level of carbonyl groups and 3-nitrotyrosine using ELISA test. Based on the reaction with Ellman's reagent, we estimated the concentration of oxidized thiol groups. Additionally, we measured the level of lipid peroxidation. Results In plasma drawn from MS patients, we observed a significantly higher level of 3-NT (92%; P EDSS and BDI. Negative correlations were observed between concentration of -SH groups and EDSS and BDI. Conclusion Our results indicate that impaired red-ox balance can significantly promote neurodegeneration in secondary progressive MS.

  12. Aluminum oxide nanoparticles alter cell cycle progression through CCND1 and EGR1 gene expression in human mesenchymal stem cells.

    Science.gov (United States)

    Periasamy, Vaiyapuri Subbarayan; Athinarayanan, Jegan; Alshatwi, Ali A

    2016-05-01

    Aluminum oxide nanoparticles (Al2 O3 -NPs) are important ceramic materials that have been used in a variety of commercial and industrial applications. However, the impact of acute and chronic exposure to Al2 O3 -NPs on the environment and on human health has not been well studied. In this investigation, we evaluated the cytotoxic effects of Al2 O3 -NPs on human mesenchymal stem cells (hMSCs) by using a cell viability assay and observing cellular morphological changes, analyzing cell cycle progression, and monitoring the expression of cell cycle response genes (PCNA, EGR1, E2F1, CCND1, CCNC, CCNG1, and CYCD3). The Al2 O3 -NPs reduced hMSC viability in a dose- and time-dependent manner. Nuclear condensation and fragmentation, chromosomal DNA fragmentation, and cytoplasmic vacuolization were observed in Al2 O3 -NP-exposed cells. The nuclear morphological changes indicated that Al2 O3 -NPs alter cell cycle progression and gene expression. The cell cycle distribution revealed that Al2 O3 -NPs cause cell cycle arrest in the sub-G0-G1 phase, and this is associated with a reduction in the cell population in the G2/M and G0/G1 phases. Moreover, Al2 O3 -NPs induced the upregulation of cell cycle response genes, including EGR1, E2F1, and CCND1. Our results suggested that exposure to Al2 O3 -NPs could cause acute cytotoxic effects in hMSCs through cell cycle regulatory genes.

  13. Ascorbic acid improves brachial artery vasodilation during progressive handgrip exercise in the elderly through a nitric oxide-mediated mechanism.

    Science.gov (United States)

    Trinity, Joel D; Wray, D Walter; Witman, Melissa A H; Layec, Gwenael; Barrett-O'Keefe, Zachary; Ives, Stephen J; Conklin, Jamie D; Reese, Van; Zhao, Jia; Richardson, Russell S

    2016-03-15

    The proposed mechanistic link between the age-related attenuation in vascular function and free radicals is an attractive hypothesis; however, direct evidence of free radical attenuation and a concomitant improvement in vascular function in the elderly is lacking. Therefore, this study sought to test the hypothesis that ascorbic acid (AA), administered intra-arterially during progressive handgrip exercise, improves brachial artery (BA) vasodilation in a nitric oxide (NO)-dependent manner, by mitigating free radical production. BA vasodilation (Doppler ultrasound) and free radical outflow [electron paramagnetic resonance (EPR) spectroscopy] were measured in seven healthy older adults (69 ± 2 yr) during handgrip exercise at 3, 6, 9, and 12 kg (∼13-52% of maximal voluntary contraction) during the control condition and nitric oxide synthase (NOS) inhibition via N(G)-monomethyl-L-arginine (L-NMMA), AA, and coinfusion of l-NMMA + AA. Baseline BA diameter was not altered by any of the treatments, while L-NMMA and L-NMMA + AA diminished baseline BA blood flow and shear rate. AA improved BA dilation compared with control at 9 kg (control: 6.5 ± 2.2%, AA: 10.9 ± 2.5%, P = 0.01) and 12 kg (control: 9.5 ± 2.7%, AA: 15.9 ± 3.7%, P vasodilation compared with control and when combined with AA eliminated the AA-induced improvement in BA vasodilation. Free radical outflow increased with exercise intensity but, interestingly, was not attenuated by AA. Collectively, these results indicate that AA improves BA vasodilation in the elderly during handgrip exercise through an NO-dependent mechanism; however, this improvement appears not to be the direct consequence of attenuated free radical outflow from the forearm.

  14. Melatonin ameliorates oxidative stress, inflammation, proteinuria, and progression of renal damage in rats with renal mass reduction.

    Science.gov (United States)

    Quiroz, Yasmir; Ferrebuz, Atilio; Romero, Freddy; Vaziri, Nosratola D; Rodriguez-Iturbe, Bernardo

    2008-02-01

    The progressive deterioration of renal function and structure resulting from renal mass reduction are mediated by a variety of mechanisms, including oxidative stress and inflammation. Melatonin, the major product of the pineal gland, has potent_antioxidant and anti-inflammatory properties, and its production is impaired in chronic renal failure. We therefore investigated if melatonin treatment would modify the course of chronic renal failure in the remnant kidney model. We studied rats followed 12 wk after renal ablation untreated (Nx group, n = 7) and treated with melatonin administered in the drinking water (10 mg/100 ml) (Nx + MEL group, n = 8). Sham-operated rats (n = 10) were used as controls. Melatonin administration increased 13-15 times the endogenous hormone levels. Rats in the Nx + MEL group had reduced oxidative stress (malondialdehyde levels in plasma and in the remnant kidney as well as nitrotyrosine renal abundance) and renal inflammation (p65 nuclear factor-kappaB-positive renal interstitial cells and infiltration of lymphocytes and macrophages). Collagen, alpha-smooth muscle actin, and transforming growth factor-beta renal abundance were all increased in the remnant kidney of the untreated rats and were reduced significantly by melatonin treatment. Deterioration of renal function (plasma creatinine and proteinuria) and structure (glomerulosclerosis and tubulointerstitial damage) resulting from renal ablation were ameliorated significantly with melatonin treatment. In conclusion, melatonin administration improves the course of chronic renal failure in rats with renal mass reduction. Further studies are necessary to define the potential usefulness of this treatment in other animal models and in patients with chronic renal disease.

  15. SYNTHESIZING ALCOHOLS AND KETONES BY PHOTOINDUCED CATALYTIC PARTIAL-OXIDATION OF HYDROCARBONS IN TI02 FILM REACTORS PREPARED BY THREE DIFFERENT METHODS

    Science.gov (United States)

    The partial oxidation of cyclohexane to cyclohexanol and cyclohexanone on UV irradiated titanium dioxide films in the presence of molecular oxygen at ambient temperatures and pressures was studied. Three different coating methodologies (dip coating using titanium isopropoxide an...

  16. Progress of research on hydrocarbon accumulation of tight sand gas and several issues for concerns%致密砂岩气成藏研究进展及值得关注的几个问题

    Institute of Scientific and Technical Information of China (English)

    郭迎春; 庞雄奇; 陈冬霞; 姜福杰; 汤国民

    2013-01-01

    Continuous tight sand gas is a significant unconventional resource for natural gas .To understand the progress of geological research on this kind of gas reservoir ,this paper summarized the criteria for identification of tight sand reser-voirs,their classification ,geological characteristics ,elements of hydrocarbon accumulation ,and trapping mechanisms .The current criteria for identivation of continuous tight sand gas reservoirs does not take accumulation conditions into conside -ration.The real critical conditions of tight sand gas change along with hydrocarbon accumulation conditions .The key ele-ments of hydrocarbon accumulation in tight gas reservoir involve hydrocarbon source rock ,tight sandstone close to source rock and stable tectonic environment .It should be noted that the nature of tight sandstone is nano-micro scale pore throat and the percentage of pore throats is about the same as that of pores ,and that abnormal pressure is not an essential differ-ence between tight sand gas reservoir and conventional gas reservoir .Several key issues concerning continuous tight sand gas accumulation are presented .The first is study on dynamic trapping mechanism for tight sand gas reservoir ,i.e.the force balance between driving force(gas pressure)and resistance(capillary force,viscous force and formation water pres-sure) at the interface of gas water inversion .The quantitative description and simulation of evolution of these forces are particularly important .The second is the research on the mechanism and process of adjustment of tight sand gas reservoir as well as restoration of the original tight sand gas reservoir .The restoration of the original reservoir can be realized by means of force balance relation at the interface of gas water inversion .All of the late adjustment and modification were realized through changing the critical conditions of gas water inversion .The third is study of the control of sandbodies with relatively high porosity and

  17. Self-ignition and oxidation of various hydrocarbons between 600 and 1000 K at high pressure: experimental study with fast compression machine and modeling; Autoinflammation et oxydation de divers hydrocarbures entre 600 et 1000 K a haute pression: etude experimentale en machine a compression rapide et modelisation

    Energy Technology Data Exchange (ETDEWEB)

    Ribaucour, M.

    2002-12-01

    Low- and intermediate-temperature oxidation and self-ignition of hydrocarbons play a major role in spark ignition, diesel and HCCI (homogenous charge compression ignition) engines. A deep understanding of the chemistry linked with both phenomena is necessary to improve the engines efficiency and to reduce the formation of pollutants. This document treats of works about the self-ignition and oxidation at high pressure of various hydrocarbons between 600 and 1000 deg. K. The experimental tool used is a fast compression machine fitted with a fast sampling system for the measurement of self-ignition delays and of the concentrations of intermediate oxidation products. The advantages and limitations of this tool are discussed. The self-ignition of various hydrocarbons is compared using pre-defined data which characterize the phenomenologies like cold flames, negative temperature coefficients and self-ignition limits. The hydrocarbons considered are pure or binary mixtures of alkanes, pent-1-ene and n-butyl-benzene. The development of high pressure oxidation reaction schemes of alkanes between 600 and 1000 deg. K is described. It is directly based on the analysis of intermediate oxidation products. This methodology is also applied to pent-1-ene and n-butyl-benzene. The construction of detailed thermo-kinetic models of oxidation and the modeling of phenomena are made for n-butane, n-heptane, for the 3 pentane isomers, for pent-1-ene and n-butyl-benzene. Finally, the perspectives of future works are evoked. They concern new modeling and new methodologies to be applied in more predictive thermo-kinetic models and the reduction of detailed models in order to include them inside fluid dynamics codes. (J.S.)

  18. 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.

  19. Cost-effectiveness of anti-oxidant vitamins plus zinc treatment to prevent the progression of intermediate age-related macular degeneration. A Singapore perspective

    OpenAIRE

    Saxena, Nakul; George, Pradeep Paul; Heng, Bee Hoon; Lim, Tock Han; Yong, Shao Onn

    2015-01-01

    Purpose: To determine if providing high dose anti-oxidant vitamins and zinc treatment age-related eye disease study (AREDS formulation) to patients with intermediate age-related macular degeneration (AMD) aged 40–79 years from Singapore is cost-effective in preventing progression to wet AMD. Methods: A hypothetical cohort of category 3 and 4 AMD patients from Singapore was followed for 5 calendar years to determine the number of patients who would progress to wet AMD given the following treat...

  20. Cost-effectiveness of anti-oxidant vitamins plus zinc treatment to prevent the progression of intermediate age-related macular degeneration. A Singapore perspective

    OpenAIRE

    Nakul Saxena; Pradeep Paul George; Bee Hoon Heng; Tock Han Lim; Shao Onn Yong

    2015-01-01

    Purpose: To determine if providing high dose anti-oxidant vitamins and zinc treatment age-related eye disease study (AREDS formulation) to patients with intermediate age-related macular degeneration (AMD) aged 40-79 years from Singapore is cost-effective in preventing progression to wet AMD. Methods: A hypothetical cohort of category 3 and 4 AMD patients from Singapore was followed for 5 calendar years to determine the number of patients who would progress to wet AMD given the following treat...

  1. The oxidative coupling of methane

    Energy Technology Data Exchange (ETDEWEB)

    Helton, T.; Anthony, R.G.; Gadalla, A.M. (Texas A and M Univ., College Park, TX (US))

    1988-01-01

    In this paper the spinel phase of cobalt oxide is evaluated as a potential coupling catalyst for converting methane to C/sub 2/+ hydrocarbons. Thermodynamic calculations indicate that the Gibbs free energies for forming higher hydrocarbons using the spinel form of cobalt oxide are similar to the free energies obtained for manganese (III) oxide. The oxidative coupling of methane was performed in an oxidation-reduction cycle.

  2. Synthesis of Cu-HMS Molecular Sieve and Aromatic Hydrocarbon Oxidation Using Cu-HMS%Cu-HMS分子筛的合成及对芳烃氧化反应的催化

    Institute of Scientific and Technical Information of China (English)

    张美英; 王乐夫; 季山; 黄仲涛; 罗维

    2004-01-01

    采用中性模板法于室温下合成了含铜的分子筛Cu-HMS,并以该分子筛为多相催化剂,对温和条件下异丙苯的氧化进行了研究.结果表明,以硝酸铜为铜源的Cu-HMS-3催化剂具有很高的催化活性,异丙苯转化率和过氧化氢异丙苯选择性都很高,分别达39.6%和98.5%.催化剂可以回收使用.另外,以Cu-HMS-3为催化剂对甲苯和乙苯的氧化进行了研究,发现在本实验条件下,甲苯未发生反应,3种芳烃的活性顺序为甲苯乙苯<异丙苯.%A copper-containing molecular sieve Cu-HMS was synthesized using the neutral templating pathway at room temperature. Then the product was used as heterogeneous catalyst for the oxidation of cumene under mild conditions. The results show that Cu-HMS-3 with copper nitrate as copper source has excellent catalytic activity, high cumene conversion and cumene hydroperoxide selectivity, that is, 39.6% and 98.5%. The catalyst can be recycled. Furthermore, the oxidations of toluene and ethylbenzene were investigated with Cu-HMS-3 as catalyst. It is found that there is no oxidation reaction observed for toluene. The activities of the three aromatic hydrocarbons follow the order of tolueneethylbenzene

  3. Photo-induced toxicity and oxidative stress responses in Tigriopus japonicus exposed to nitro-polycyclic aromatic hydrocarbons and artificial light.

    Science.gov (United States)

    Onduka, Toshimitsu; Ojima, Daisuke; Ito, Katsutoshi; Mochida, Kazuhiko; Ito, Mana; Koyama, Jiro; Fujii, Kazunori

    2017-02-01

    Photo-induced toxicity is an important phenomenon in ecotoxicology because sunlight reaches many organisms in their natural habitats. To elucidate whether sunlight enhances the toxicity of nitro-polycyclic aromatic hydrocarbons (nitro-PAHs), the acute toxicities of 10 nitro-PAHs and the related compound 1-nitropyrene (1-NP) to Tigriopus japonicus were assessed in darkness or under light conditions. In addition, the relationships among the toxicity of 1-NP to T. japonicus, lighting condition, and the concentration of reactive oxygen species (ROS) formed were investigated in the presence or absence of the ROS scavenger ascorbic acid in the test solutions. Light irradiation increased the toxicity of all tested nitro-PAHs except 1,5-dinitronaphthalene. Among the compounds tested, 1-NP was the most phototoxic: it was more than 1000 times more toxic under the light conditions than in darkness. In contrast, at the same light levels, pyrene was not phototoxic. Light irradiation induced the generation of ROS in the 1-NP exposure groups, and the immobilization rate of T. japonicus increased with the amount of ROS produced. The addition of ascorbic acid to the test solutions suppressed both the generation of ROS and the light-induced immobilization of T. japonicus. To accurately assess the ecotoxicologic risk of nitro-PAHs, their overall photo-induced toxicity must be considered.

  4. Genome sequencing and annotation of Geobacillus sp. 1017, a hydrocarbon-oxidizing thermophilic bacterium isolated from a heavy oil reservoir (China

    Directory of Open Access Journals (Sweden)

    Vitaly V. Kadnikov

    2017-03-01

    Full Text Available The draft genome sequence of Geobacillus sp. strain 1017, a thermophilic aerobic oil-oxidizing bacterium isolated from formation water of the Dagang high-temperature oilfield, China, is presented here. The genome comprised 3.6 Mbp, with the G + C content of 51.74%. The strain had a number of genes responsible for numerous metabolic and transport systems, exopolysaccharide biosynthesis, and decomposition of sugars and aromatic compounds, as well as the genes related to resistance to metals and metalloids. The genome sequence is available at DDBJ/EMBL/GenBank under the accession no MQMG00000000. This genome is annotated for elucidation of the genomic and phenotypic diversity of new thermophilic alkane-oxidizing bacteria of the genus Geobacillus.

  5. A small molecule polyamine oxidase inhibitor blocks androgen-induced oxidative stress and delays prostate cancer progression in the transgenic adenocarcinoma of the mouse prostate model.

    Science.gov (United States)

    Basu, Hirak S; Thompson, Todd A; Church, Dawn R; Clower, Cynthia C; Mehraein-Ghomi, Farideh; Amlong, Corey A; Martin, Christopher T; Woster, Patrick M; Lindstrom, Mary J; Wilding, George

    2009-10-01

    High levels of reactive oxygen species (ROS) present in human prostate epithelia are an important etiologic factor in prostate cancer (CaP) occurrence, recurrence, and progression. Androgen induces ROS production in the prostate by a yet unknown mechanism. Here, to the best of our knowledge, we report for the first time that androgen induces an overexpression of spermidine/spermine N1-acetyltransferase, the rate-limiting enzyme in the polyamine oxidation pathway. As prostatic epithelia produce a large excess of polyamines, the androgen-induced polyamine oxidation that produces H2O2 could be a major reason for the high ROS levels in the prostate epithelia. A small molecule polyamine oxidase inhibitor N,N'-butanedienyl butanediamine (MDL 72,527 or CPC-200) effectively blocks androgen-induced ROS production in human CaP cells, as well as significantly delays CaP progression and death in animals developing spontaneous CaP. These data show that polyamine oxidation is not only a major pathway for ROS production in prostate, but inhibiting this pathway also successfully delays CaP progression.

  6. A Small Molecule Polyamine Oxidase Inhibitor Blocks Androgen-Induced Oxidative Stress and Delays Prostate Cancer Progression in the TRAMP Mouse Model

    Science.gov (United States)

    Basu, Hirak S.; Thompson, Todd A.; Church, Dawn R.; Clower, Cynthia C.; Mehraein-Ghomi, Farideh; Amlong, Corey A.; Martin, Christopher T.; Woster, Patrick M.; Lindstrom, Mary J.; Wilding, George

    2009-01-01

    High levels of reactive oxygen species (ROS) present in human prostate epithelia are an important etiological factor in prostate cancer (CaP) occurrence, recurrence and progression. Androgen induces ROS production in the prostate by a yet unknown mechanism. Here, to the best of our knowledge, we report for the first time that androgen induces an overexpression of spermidine/spermine N1-acetyltransferase (SSAT), the rate-limiting enzyme in the polyamine oxidation pathway. As prostatic epithelia produce a large excess of polyamines, the androgen-induced polyamine oxidation that produces H2O2 could be a major reason for the high ROS levels in the prostate epithelia. A small molecule polyamine oxidase inhibitor N,N'-butanedienyl butanediamine (MDL 72,527 or CPC-200) effectively blocks androgen-induced ROS production in human CaP cells as well as significantly delays CaP progression and death in animals developing spontaneous CaP. These data demonstrate that polyamine oxidation is not only a major pathway for ROS production in prostate, but inhibiting this pathway also successfully delays prostate cancer progression. PMID:19773450

  7. Impact of oxidation and biodegradation on the most commonly used polycyclic aromatic hydrocarbon (PAH) diagnostic ratios: Implications for the source identifications.

    Science.gov (United States)

    Biache, Coralie; Mansuy-Huault, Laurence; Faure, Pierre

    2014-02-28

    Based on the isomer stability during their formation, PAH diagnostic ratios have been extensively used to determine PAH contamination origin. Nevertheless, it is known that these isomers do not present the same physicochemical properties and that reactions occurring during the transport from an atmospheric source induce changes in the diagnostic ratios. Yet, little is known about reactions occurring in soils contaminated by other sources such as coal tar and coal. Innovative batch experiments of abiotic oxidation and microbial incubations were performed to discriminate independently the influence of these two major processes occurring in soils on the diagnostic ratios of major PAH sources. Three samples were studied, a coking plant soil and two major PAH sources in this soil, namely coal and coal tar. The combustion signature of the coking plant soil showed the major influence of coal tar in the soil sample composition. Some of these ratios were drastically affected by oxidation and biodegradation processes inducing a change in the source signature. The coal tar signature changed to petrogenic source after oxidation with the anthracene/(anthracene+phenanthrene) ratio. According to this ratio, the initial petrogenic signature of the coal changed to a combustion signature after the biodegradation experiment.

  8. 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...

  9. 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.

  10. 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.

  11. 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.

  12. Oxidative Stress during the Progression of β-Amyloid Pathology in the Neocortex of the Tg2576 Mouse Model of Alzheimer's Disease.

    Science.gov (United States)

    Porcellotti, Sara; Fanelli, Francesca; Fracassi, Anna; Sepe, Sara; Cecconi, Francesco; Bernardi, Cinzia; Cimini, AnnaMaria; Cerù, Maria Paola; Moreno, Sandra

    2015-01-01

    Alzheimer's disease (AD) is the most common form of dementia, characterized by progressive neurodegeneration. Pathogenetic mechanisms, triggered by β-amyloid (Aβ) accumulation, include oxidative stress, derived from energy homeostasis deregulation and involving mitochondria and peroxisomes. We here addressed the oxidative stress status and the elicited cellular response at the onset and during the progression of Aβ pathology, studying the neocortex of Tg2576 model of AD. Age-dependent changes of oxidative damage markers, antioxidant enzymes, and related transcription factors were analysed in relation to the distribution of Aβ peptide and oligomers, by a combined molecular/morphological approach. Nucleic acid oxidative damage, accompanied by defective antioxidant defences, and decreased PGC1α expression are already detected in 3-month-old Tg2576 neurons. Conversely, PPARα is increased in these cells, with its cytoplasmic localization suggesting nongenomic, anti-inflammatory actions. At 6 months, when intracellular Aβ accumulates, PMP70 is downregulated, indicating impairment of fatty acids peroxisomal translocation and their consequent harmful accumulation. In 9-month-old Tg2576 neocortex, Aβ oligomers and acrolein deposition correlate with GFAP, GPX1, and PMP70 increases, supporting a compensatory response, involving astroglial peroxisomes. At severe pathological stages, when senile plaques disrupt cortical cytoarchitecture, antioxidant capacity is gradually lost. Overall, our data suggest early therapeutic intervention in AD, also targeting peroxisomes.

  13. Catalytic carbon deposition-oxidation over Ni, Fe and Co catalysts: a new indirect route to store and transport gas hydrocarbon fuels.

    OpenAIRE

    Oliveira, Patrícia E. F.; Ribeiro, Leandro Passos; Rosmaninho, Marcelo Gonçalves; Ardisson, José Domingos; Dias, Anderson; Oliveira,Luiz Carlos Alves; Lago, Rochel Montero

    2013-01-01

    In this work, a new two-step route to store and transport associated natural gas, promoted by Ni, Fe and Co supported catalyst was presented. Initially, CH4 is converted into carbon deposits (M/C composite), being Fe catalyst the most active catalyst. In Step 2, M/C composite reacts with H2O producing H2, CO and CH4. TPO experiments showed that efficiency and selectivity of oxidation depends on the metal. Ni catalyst produced mainly H2 and CO, while Fe system was more selective to convert car...

  14. Research progress on the oxidative rancidity of oils and fats%油脂氧化酸败研究进展

    Institute of Scientific and Technical Information of China (English)

    曹文明; 薛斌; 袁超; 印瑜洁; 王鑫; 王兴国

    2013-01-01

    Rancidity of oisl and fats is closely related to flavor deterioration,nutrient loss,biological damage and tissue aging. This article overviewed the evolution of lipid oxidation theory,with the theory of auto–oxidative free radical chain reaction as the focus. Besides,the research progress&relationship among autoxidation,photosensitive oxidation and enzyme–catalyzed oxidation was elucidated. Auto–oxidation is in a dominant position in the lipid oxidation. Photosensitive oxidation and enzyme–catalyzed oxidation may play a key role in the initiation of the reaction. Photosensitive oxidation may follow either type II pathway of singlet oxidation or type I pathway of free radical chain oxidation, depending on whether the excited photosensitizer abstracts hydrogen with substrate,or directly attacks the unsaturated double bond. Enzyme–catalyzed oxidation acts similarly to free radical chain reaction under aerobic conditions,and lipoxygenase will have no activity under anaerobic conditions.%  油脂氧化酸败与风味劣变、营养丧失、生物学损害、组织老化紧密相关。该文概述油脂氧化研究以自动氧化自由基链式反应学说为核心发展历程;阐述自动氧化、光敏氧化、酶促氧化之间关联性与研究进展。自动氧化在油脂氧化中处主导地位,而光敏氧化和酶促氧化很可能在诱发氧化前期起关键作用;光敏氧化既可循II型单线态氧化途径,又可循I型自由基链式氧化途径,取决于激发态光敏剂是底物脱氢、还是直接攻击不饱和双键;酶促氧化在有氧条件下类似自由基链式反应,无氧条件下脂氧酶无活性。

  15. Geologic and geochemical studies of the New Albany Group (Devonian black shale) in Illinois to evaluate its characteristics as a source of hydrocarbons. Quarterly progress report, October 1-December 31, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Bergstrom, R.E.; Shimp, N.F.

    1979-01-01

    This proect is a detailed analysis of the lithology, stratiraphy, and structure of the New Albany Group in Illinois to determine those characteristics of lithology, thickness, regional distribution, vertical andlateral variability, and deformation that are most relevant to the occurrence of hydrocarbons.

  16. 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.

  17. Plasma Vascular Endothelial Growth Factor Concentration and Alveolar Nitric Oxide as Potential Predictors of Disease Progression and Mortality in Idiopathic Pulmonary Fibrosis

    Directory of Open Access Journals (Sweden)

    Jalpa Kotecha

    2016-09-01

    Full Text Available Background: Declining lung function signifies disease progression in idiopathic pulmonary fibrosis (IPF. Vascular endothelial growth factor (VEGF concentration is associated with declining lung function in 6 and 12-month studies. Alveolar nitric oxide concentration (CANO is increased in patients with IPF, however its significance is unclear. This study investigated whether baseline plasma VEGF concentration and CANO are associated with disease progression or mortality in IPF. Methods: 27 IPF patients were studied (maximum follow-up 65 months. Baseline plasma VEGF concentration, CANO and pulmonary function tests (PFTs were measured. PFTs were performed the preceding year and subsequent PFTs and data regarding mortality were collected. Disease progression was defined as one of: death, relative decrease of ≥10% in baseline forced vital capacity (FVC % predicted, or relative decrease of ≥15% in baseline single breath diffusion capacity of carbon monoxide (TLCO-SB % predicted. Results: Plasma VEGF concentration was not associated with progression-free survival or mortality. There was a trend towards shorter time to disease progression and death with higher CANO. CANO was significantly higher in patients with previous declining versus stable lung function. Conclusion: The role of VEGF in IPF remains uncertain. It may be of value to further investigate CANO in IPF.

  18. Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane. Quarterly technical progress report 10, July 1, 1995--September 31, 1995

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, R.L.

    1995-12-07

    This document is the tenth quarterly technical progress report under Contract No. DE-AC22-92PC92110 {open_quotes}Development of Vanadium-Phosphate Catalysts for Methanol Production by Selective Oxidation of Methane{close_quotes}. Activities focused on testing of additional modified and promoted catalysts and characterization of these materials. Attempts at improving the sensitivity of our GC based analytical systems were also made with some success. Methanol oxidation studies were initiated. These results are reported. Specific accomplishments include: (1) Methane oxidation testing of a suite of catalysts promoted with most of the first row transition metals was completed. Several of these materials produced low, difficult to quantify yields of formaldehyde. (2) Characterization of these materials by XRD and FTIR was performed with the goal of correlating activity and selectivity with catalyst properties. (3) We began to characterize catalysts prepared via modified synthesis methods designed to enhance acidity using TGA measurements of acetonitrile chemisorption and methanol dehydration to dimethyl ether as a test reaction. (4) A catalyst prepared in the presence of naphthalene methanol as a structural disrupter was tested for activity in methane oxidation. It was found that this material produced low yields of formaldehyde which were difficult to quantify. (5) Preparation of catalysts with no Bronsted acid sites. This was accomplished by replacement of exchangeable protons with potassium, and (6) Methanol oxidation studies were initiated to provide an indication of catalyst activity for decomposition of this desired product and as a method of characterizing the catalyst surface.

  19. Epoetin beta pegol alleviates oxidative stress and exacerbation of renal damage from iron deposition, thereby delaying CKD progression in progressive glomerulonephritis rats.

    Science.gov (United States)

    Hirata, Michinori; Tashiro, Yoshihito; Aizawa, Ken; Kawasaki, Ryohei; Shimonaka, Yasushi; Endo, Koichi

    2015-12-01

    The increased deposition of iron in the kidneys that occurs with glomerulopathy hinders the functional and structural recovery of the tubules and promotes progression of chronic kidney disease (CKD). Here, we evaluated whether epoetin beta pegol (continuous erythropoietin receptor activator: CERA), which has a long half-life in blood and strongly suppresses hepcidin-25, exerts renoprotection in a rat model of chronic progressive glomerulonephritis (cGN). cGN rats showed elevated urinary total protein excretion (uTP) and plasma urea nitrogen (UN) from day 14 after the induction of kidney disease (day 0) and finally declined into end-stage kidney disease (ESKD), showing reduced creatinine clearance with glomerulosclerosis, tubular dilation, and tubulointerstitial fibrosis. A single dose of CERA given on day 1, but not on day 16, alleviated increasing uTP and UN, thereby delaying ESKD. In the initial disease phase, CERA significantly suppressed urinary 8-OHdG and liver-type fatty acid-binding protein (L-FABP), a tubular damage marker. CERA also inhibited elevated plasma hepcidin-25 levels and alleviated subsequent iron accumulation in kidneys in association with elevated urinary iron excretion and resulted in alleviation of growth of Ki67-positive tubular and glomerular cells. In addition, at day 28 when the exacerbation of uTP occurs, a significant correlation was observed between iron deposition in the kidney and urinary L-FABP. In our study, CERA mitigated increasing kidney damage, thereby delaying CKD progression in this glomerulonephritis rat model. Alleviation by CERA of the exacerbation of kidney damage could be attributable to mitigation of tubular damage that might occur with lowered iron deposition in tubules.

  20. Correlation of TGF-β1 and oxidative stress in the blood of patients with melanoma: a clue to understanding melanoma progression?

    Science.gov (United States)

    Santos Bernardes, Sara; de Souza-Neto, Fernando Pinheiro; Pasqual Melo, Gabriella; Guarnier, Flávia Alessandra; Marinello, Poliana Camila; Cecchini, Rubens; Cecchini, Alessandra L

    2016-08-01

    TGF-β1 and oxidative stress are involved in cancer progression, but in melanoma, their role is still controversial. Our aim was to correlate plasma TGF-β1 levels and systemic oxidative stress biomarkers in patients with melanoma, with or without disease metastasis, to understand their participation in melanoma progression. Thirty patients were recruited for melanoma surveillance, together with 30 healthy volunteers. Patients were divided into two groups: Non-metastasis, comprising patients with tumor removal and no metastatic episode for 3 years; and Metastasis, comprising patients with a metastatic episode. The plasmatic cytokines TGF-β1, IL-1 β, and TNF-α were analyzed by ELISA. For oxidative stress, the following assays were performed: malondialdehyde (MDA), advanced oxidation protein products (AOPP) levels, total radical-trapping antioxidant parameter (TRAP) and thiol in plasma, and lipid peroxidation, SOD and catalase activity and GSH in erythrocytes. Patients with a metastatic episode had less circulating TGF-β1 and increased TRAP, thiol, AOPP and lipid peroxidation levels. MDA was increased in both melanoma groups, while catalase, GSH, and IL-1β was decreased in Non-metastasis patients. Significant negative correlations were observed between TGF-β1 levels and systemic MDA, and TGF-β1 levels and systemic AOPP, while a positive correlation was observed between TGF-β1 levels and erythrocyte GSH. Lower levels of TGF-β1 were related to increased oxidative stress in Metastasis patients, reinforcing new evidence that in melanoma TGF-β1 acts as a tumor suppressor, inhibiting tumor relapse. These findings provide new knowledge concerning this cancer pathophysiology, extending the possibilities of investigating new therapies based on this evidence.

  1. Astaxanthin protects against early burn-wound progression in rats by attenuating oxidative stress-induced inflammation and mitochondria-related apoptosis

    Science.gov (United States)

    Fang, Quan; Guo, Songxue; Zhou, Hanlei; Han, Rui; Wu, Pan; Han, Chunmao

    2017-01-01

    Burn-wound progression can occur in the initial or peri-burn area after a deep burn injury. The stasis zone has a higher risk of deterioration mediated by multiple factors but is also considered salvageable. Astaxanthin (ATX), which is extracted from some marine organisms, is a natural compound with a strong antioxidant effect that has been reported to attenuate organ injuries caused by traumatic injuries. Hence, we investigated the potential effects of ATX on preventing early burn-wound progression. A classic “comb” burn rat model was established in this study for histological and biological assessments, which revealed that ATX, particularly higher doses, alleviated histological deterioration in the stasis zone. Additionally, we observed dose-dependent improvements in oxidative stress and the release of inflammatory mediators after ATX treatment. Furthermore, ATX dose-dependently attenuated burn-induced apoptosis in the wound areas, and this effect was accompanied by increases in Akt and Bad phosphorylation and a downregulation of cytochrome C and caspase expression. In addition, the administration of Ly 294002 further verified the effect of ATX. In summary, we demonstrated that ATX protected against early burn-wound progression in a rat deep-burn model. This protection might be mediated by the attenuation of oxidative stress-induced inflammation and mitochondria-related apoptosis. PMID:28128352

  2. 氧化应激对成骨细胞功能的影响%Research progress of oxidation stress in regulating of osteoblast function

    Institute of Scientific and Technical Information of China (English)

    王小菊; 冯正平

    2015-01-01

    Osteoporosis (OP) is an metabolic bone disease that affects human health, and its initiation and progress are closely related with the osteoblast function, such as proliferation, differentiation, apoptosis, and autophagy.ROS, the main source of oxidation stress, affects osteoblast function.To date, the research in mecha-nisms of oxidation stress on osteoblast function and relationship between autophagy and apoptosis, proliferation and differentiation have made great progress, and this paper makes a review about research of oxidation stress in regula-tion of osteoblast function.%骨质疏松的发生、发展与成骨细胞增殖、分化、凋亡和自噬等功能密切相关。活性氧( ROS)所致的氧化应激影响成骨细胞功能。本文对氧化应激影响成骨细胞功能的分子机制及与自噬与凋亡、增殖、分化间的相互联系作一综述。

  3. Hydrocarbon Reserves: Abundance or Scarcity

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    impact on the growth of reserves and resources (H. Le Leuch); Additional reserves: the role of new technologies - A global perspective on EORIOR (G. Fries); - Updating reservoir models with dynamic data and uncertainty quantification: an integrated approach (F. Roggero); Seismic technology for the OAPEC countries (P. Canal); Exploration knowledge and technologies: impact of progress - Statistical results (N. Alazard); Stratigraphic modelling as a key to find new potentialities in exploration (D. Granjeon); Modelling hydrocarbon migration as a tool for reserve estimation (J-L. Rudkiewicz); The contribution of surface and near surface geology to hydrocarbon discoveries (S.M. Kumati); Contribution of the exploration activity in renewing reserves - The case of Algeria (R. Lounissi); Egypt's petroleum hydrocarbon potential (H. Hataba); Future of hydrocarbon reserves in Syria (T. Hemsh); Natural gas, the fuel of choice for decades to com (M.F. Chabrelie); The role and importance of Arab natural gas in world market (M. Al-Lababidi); LNG and GTL: two pathways for natural gas utilization (C. Cameron); Yet to find hydrocarbon potential (S. Al Menhali); Libyan context of hydrocarbon reserves: abundance or scarcity? (M. Elazi)

  4. X-ray structure of a hydroxylase-regulatory protein complex from a hydrocarbon-oxidizing multicomponent monooxygenase, Pseudomonas sp. OX1 phenol hydroxylase.

    Science.gov (United States)

    Sazinsky, Matthew H; Dunten, Pete W; McCormick, Michael S; DiDonato, Alberto; Lippard, Stephen J

    2006-12-26

    Phenol hydroxylase (PH) belongs to a family of bacterial multicomponent monooxygenases (BMMs) with carboxylate-bridged diiron active sites. Included are toluene/o-xylene (ToMO) and soluble methane (sMMO) monooxygenase. PH hydroxylates aromatic compounds, but unlike sMMO, it cannot oxidize alkanes despite having a similar dinuclear iron active site. Important for activity is formation of a complex between the hydroxylase and a regulatory protein component. To address how structural features of BMM hydroxylases and their component complexes may facilitate the catalytic mechanism and choice of substrate, we determined X-ray structures of native and SeMet forms of the PH hydroxylase (PHH) in complex with its regulatory protein (PHM) to 2.3 A resolution. PHM binds in a canyon on one side of the (alphabetagamma)2 PHH dimer, contacting alpha-subunit helices A, E, and F approximately 12 A above the diiron core. The structure of the dinuclear iron center in PHH resembles that of mixed-valent MMOH, suggesting an Fe(II)Fe(III) oxidation state. Helix E, which comprises part of the iron-coordinating four-helix bundle, has more pi-helical character than analogous E helices in MMOH and ToMOH lacking a bound regulatory protein. Consequently, conserved active site Thr and Asn residues translocate to the protein surface, and an approximately 6 A pore opens through the four-helix bundle. Of likely functional significance is a specific hydrogen bond formed between this Asn residue and a conserved Ser side chain on PHM. The PHM protein covers a putative docking site on PHH for the PH reductase, which transfers electrons to the PHH diiron center prior to O2 activation, suggesting that the regulatory component may function to block undesired reduction of oxygenated intermediates during the catalytic cycle. A series of hydrophobic cavities through the PHH alpha-subunit, analogous to those in MMOH, may facilitate movement of the substrate to and/or product from the active site pocket

  5. 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...

  6. Progress in Bismuth-Contained Mixed Conducting Oxide Membranes%铋基混合导体透氧陶瓷膜的研究进展

    Institute of Scientific and Technical Information of China (English)

    邵宗平; 熊国兴; 等

    2001-01-01

    Mixed oxygen-ion and electronic conducting ceramic membranes have received increasing attention in the past decade. The progress in bismuth-contained mixed conducting oxide membranes was reviewed, considerable attention was paid to the progress made in our group during the past years. The problems associated with the bismuth-contained materials were discussed. The promising developing direction was also pointed out.%近十几年来, 混合导体透氧致密膜日益受到人们的重视. 本文主要对铋基混合导体膜的研究进展进行了较为全面的概述, 着重介绍了我组近年来在此领域的研究进展, 同时对其所可能存在的问题进行了分析并提出了展望.

  7. Neutronics Benchmarks for the Utilization of Mixed-Oxide Fuel: Joint US/Russian Progress Report for Fiscal 1997. Volume 3 - Calculations Performed in the Russian Federation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-06-01

    This volume of the progress report provides documentation of reactor physics and criticality safety studies conducted in the Russian Federation during fiscal year 1997 and sponsored by the Fissile Materials Disposition Program of the US Department of Energy. Descriptions of computational and experimental benchmarks for the verification and validation of computer programs for neutron physics analyses are included. All benchmarks include either plutonium, uranium, or mixed uranium and plutonium fuels. Calculated physics parameters are reported for all of the contaminated benchmarks that the United States and Russia mutually agreed in November 1996 were applicable to mixed-oxide fuel cycles for light-water reactors.

  8. Microbial Hydrocarbon and ToxicPollutant Degradation Method

    Energy Technology Data Exchange (ETDEWEB)

    Schlueter, Dietrich [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Janabi, Mustafa [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); O' Neil, James [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Budinger, Thomas [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2011-08-16

    The goal of this project is to determine optimum conditions for bacterial oxidation of hydrocarbons and long-chain alkanes that are representative of petroleum contamination of the environment. Polycyclic Aromatic Hydrocarbons (PAHs) are of concern because of their toxicity, low volatility, and resistance to microbial degradation, especially under anaerobic conditions. The uniqueness of our approach is to use carbon-11 in lieu of the traditional use of carbon-14.

  9. 油脂氧化评价研究进展%Research progresses on lipids rancidity and oxidation evaluation

    Institute of Scientific and Technical Information of China (English)

    曹文明; 王鑫; 包杰; 金青哲; 王兴国

    2013-01-01

    The research presented a detailed analysis of the main deterioration pathways and products in oil air oxidation,high temperature oxidation and thermal alteration. Both the evaluation strategy of the rancidity degree by means of oxidative products and the index method for classic primary oxidative products and secondary oxidative products were discussed in the article. The application prospect of oxidized triacylglycerol polymers and high–performance size–exclusion chromatography in controlling virgin oil quality and discerning oil adulteration was also included%  该文分析油脂空气氧化、高温氧化、热质变主要劣变路径与产物;评述以氧化产物评价酸败程度策略,经典初级氧化产物、次级氧化产物指标方法,氧化三酰甘油聚合物及高效体积排阻凝胶渗透色谱技术在初榨油质量控制与掺伪鉴别方面应用前景。

  10. Direct conversion of light hydrocarbon gases to liquid fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, R.D.; Foral, M.J.

    1992-05-16

    Amoco oil Company, has investigated the direct, non-catalytic conversion of light hydrocarbon gases to liquid fuels (particularly methanol) via partial oxidation. The primary hydrocarbon feed used in these studies was natural gas. This report describes work completed in the course of our two-year project. In general we determined that the methanol yields delivered by this system were not high enough to make it economically attractive. Process variables studied included hydrocarbon feed composition, oxygen concentration, temperature and pressure effects, residence time, reactor design, and reactor recycle.

  11. Direct conversion of light hydrocarbon gases to liquid fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, R.D.; Foral, M.J.

    1992-05-16

    Amoco oil Company, has investigated the direct, non-catalytic conversion of light hydrocarbon gases to liquid fuels (particularly methanol) via partial oxidation. The primary hydrocarbon feed used in these studies was natural gas. This report describes work completed in the course of our two-year project. In general we determined that the methanol yields delivered by this system were not high enough to make it economically attractive. Process variables studied included hydrocarbon feed composition, oxygen concentration, temperature and pressure effects, residence time, reactor design, and reactor recycle.

  12. Research progress in preparation of nano - oxides by hydrothermal method%水热法制备纳米氧化物的研究进展

    Institute of Scientific and Technical Information of China (English)

    郑兴芳

    2009-01-01

    简述了水热法的原理和特点.介绍了水热晶化法、水热氧化法、水热还原法、水热沉淀法、水热分解法、水热合成法制备纳米氧化物的特点和现状,并介绍了水热法与其他方法的联合应用,如:微波-水热法、微乳液-水热法、溶胶(凝胶)-水热法等制备纳米氧化物的研究进展.最后对水热法制备纳米氧化物进行了展望.%Principle and characteristics of hydrothermal method were briefly introduced.Characteristics and present situ - ation of hydrothermal methods,including hydrothermal - crystallization,oxidation,reduction,precipitation,decomposition,and synthesis - methods,of nano - oxides were reviewed.Research progress in combination of hydrothermal method with other synthetic methods,such as microwave-hydrothermal,microemulsion-hydrothermal,and sol(gel)-hydrothermal,which were applied in preparation of nano - oxides were also discussed.At last,preparation of nano - oxides by hydrothermal method was also prospected.

  13. Effect of hydrocarbons on plasma treatment of NOx

    Energy Technology Data Exchange (ETDEWEB)

    Penetrante, B.M.; Pitz, W.J.; Hsaio, M.C.; Merritt, B.T.; Vogtlin, G.E. [Lawrence Livermore National Lab., CA (United States)

    1997-12-31

    Lean burn gasoline engine exhausts contain a significant amount of hydrocarbons in the form of propene. Diesel engine exhausts contain little gaseous hydrocarbon; however, they contain a significant amount of liquid-phase hydrocarbons (known as the volatile organic fraction) in the particulates. The objective of this paper is to examine the fate of NO{sub x} when an exhaust gas mixture that contains hydrocarbons is subjected to a plasma. The authors will show that the hydrocarbons promote the oxidation of NO to NO{sub 2}, but not the reduction of NO to N{sub 2}. The oxidation of NO to NO{sub 2} is strongly coupled with the hydrocarbon oxidation chemistry. This result suggests that gas-phase reactions in the plasma alone cannot lead to the chemical reduction of NO{sub x}. Any reduction of NO{sub x} to N{sub 2} can only be accomplished through heterogeneous reactions of NO{sub 2} with surfaces or particulates.

  14. 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.

  15. Impact of nitrogen flushing and oil choice on the progression of lipid oxidation in unwashed fried sliced potato crisps.

    Science.gov (United States)

    Marasca, E; Greetham, D; Herring, S D; Fisk, I D

    2016-05-15

    Unwashed, sliced, batch-fried potato crisps have a unique texture and are growing in popularity in the UK/EU premium snack food market. In this study, the storage stability of unwashed sliced (high surface starch) potatoes (crisps) fried in regular sunflower oil (SO) or in high oleic sunflower oil (HOSO) was compared over accelerated shelf life testing (45°C, 6 weeks); with and without nitrogen gas flushing. Primary oxidation products (lipid hydroperoxides) were measured with a ferrous oxidation-xylenol orange (FOX) assay and volatile secondary oxidation products (hexanal) were quantified by using solid phase micro-extraction gas chromatography mass spectrometry (HS-SPME-GC/MS). Results revealed that crisps fried in SO were the least stable. Flushing the stored crisps with nitrogen gas proved to be effective in slowing down the oxidation rate after frying with sunflower oil, significantly stabilizing the crisps. However, crisps fried in HOSO were the most stable, with the lowest rate of development of oxidation markers, and this has previously not been shown for crisps with a high free starch content.

  16. Development of vanidum-phosphate catalysts for methanol production by selective oxidation of methane. Quarterly technical progress report, 1996

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, R.L.; Alptekin, G.O.

    1996-06-01

    Activities this past quarter, focused on acquisition of kinetic data for oxidation of formaldehyde and methanol on these catalysts. In the next quarter these results will be used to propose a simple reaction network and kinetic model. To date we have completed Task 1: Laboratory Setup and Task 2: Process Variable Study. Activities in the current quarter focused on finalizing these tasks and on Task 3: Promoters and Supports, this task is approximately 50% completed. Task 4: Advanced Catalysts is to be initiated in the next quarter. Specific accomplishments this quarter include: finalizing and calibrating a new reaction product analytical system with markedly improved precision and accuracy relative to older. approaches; development of procedures for accurately feeding formaldehyde to the reactor; examination of formaldehyde and methanol oxidation kinetics over vanadyl pyrophosphate at a range of temperatures; and preliminary studies of methane oxidation over a silica support.

  17. Relationship between the Increased Haemostatic Properties of Blood Platelets and Oxidative Stress Level in Multiple Sclerosis Patients with the Secondary Progressive Stage

    Directory of Open Access Journals (Sweden)

    Agnieszka Morel

    2015-01-01

    Full Text Available Multiple sclerosis (MS is the autoimmune disease of the central nervous system with complex pathogenesis, different clinical courses and recurrent neurological relapses and/or progression. Despite various scientific papers that focused on early stage of MS, our study targets selective group of late stage secondary progressive MS patients. The presented work is concerned with the reactivity of blood platelets in primary hemostasis in SP MS patients. 50 SP MS patients and 50 healthy volunteers (never diagnosed with MS or other chronic diseases were examined to evaluate the biological activity of blood platelets (adhesion, aggregation, especially their response to the most important physiological agonists (thrombin, ADP, and collagen and the effect of oxidative stress on platelet activity. We found that the blood platelets from SP MS patients were significantly more sensitive to all used agonists in comparison with control group. Moreover, the platelet hemostatic function was advanced in patients suffering from SP MS and positively correlated with increased production of O2-∙ in these cells, as well as with Expanded Disability Status Scale. We postulate that the increased oxidative stress in blood platelets in SP MS may be primarily responsible for the altered haemostatic properties of blood platelets.

  18. 金属卟啉催化氧化环己烷反应的研究进展%Kesearch Progress of Cyclohexane Oxidation Catalyzed by Metalloporphyrins

    Institute of Scientific and Technical Information of China (English)

    沈阳; 杨晓杰; 孙巍; 张莹; 谭伶玉; 唐丽华

    2011-01-01

    In order to select a excellent catalyst for biomimetic catalytic oxidation of cyclohexane, some literatures at home and abroad on metalporphyrin biomimetic catalytis oxidation of hydrocarbons is summarized in this paper. The focus is the types and varieties of metalloporphyrin compounds used in catalytic oxidation of cyclohexane. Among these metalloporphyrin catalysts, the and its derivatives metal complexes are researched most actively. The main metals complexed are the transition metals such as Fe, Mn, Co. The single metalporphyrins, dual-core metalporphyrins and immobilized metalporphyrins are the main types of metalloporphyrin biomimetic catalysts. The single metalporphyrin catalysts are studied more maturely, and the catalytic activity of the metalloporphyrin is higher than others which benzene ring is substituted by electron-withdrawing groups.%为了筛选仿生催化氧化环己烷反应的优异催化剂,查阅了国内外有关金属卟啉仿生催化氧化烃类的一些文献资料,重点归纳总结了用作仿生催化空气氧化环己烷反应的金属卟啉化合物的类型和种类。其中,研究最为活跃的是中位取代四苯基卟啉及其衍生物的金属配合物,络合的金属主要是过渡金属Fe、Mn、Co。金属卟啉仿酶催化剂品种中,主要有单金属卟啉、双核金属卟啉和固载金属睡卜啉等三种类型,其中研究较为成熟的是单金属卟啉催化剂,且苯环上取代吸电子基团的金属卟啉仿酶催化剂的催化活性较高。

  19. 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.

  20. 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.

  1. 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.

  2. 液相法合成纳米氧化锌的研究进展%Research progress in liquid-phase synthesis of nanosized zinc oxide

    Institute of Scientific and Technical Information of China (English)

    郑兴芳

    2009-01-01

    The synthesis methods of nanosized zinc oxide by liquid phase methods in recent years were reviewed. The synthesis methods include precipitation, hydrothermal, solvothermal, sol-gel and microemulsion method. The advan-tages and disadvantages of several liquid phase methods were analyzed and their research progress of synthesis in recent years were described. It also pointed out that some new techniques, such as microwave and ultrasonic et al have been intro-duced in the preparation of nanosized zinc oxide and the future development direction of nanosized zinc oxide synthesis was towards the comprehensiveness of technology.%综述了近年来合成纳米氧化锌的液相方法,包括沉淀法、水热法、溶剂热法、溶胶-凝胶法、微乳液法等.分析了这几种方法的优缺点和最新的研究进展.同时指出,微波、超声等新技术也引入到液相法纳米氧化锌的制备工艺中,纳米氧化锌合成的未来发展方向是合成技术综合化.

  3. Moving hydrocarbons through portions of tar sands formations with a fluid

    Science.gov (United States)

    Stegemeier, George Leo; Mudunuri, Ramesh Raju; Vinegar, Harold J.; Karanikas, John Michael; Jaiswal, Namit; Mo, Weijian

    2010-05-18

    A method for treating a tar sands formation is disclosed. The method includes heating a first portion of a hydrocarbon layer in the formation from one or more heaters located in the first portion. The heat is controlled to increase a fluid injectivity of the first portion. A drive fluid and/or an oxidizing fluid is injected and/or created in the first portion to cause at least some hydrocarbons to move from a second portion of the hydrocarbon layer to a third portion of the hydrocarbon layer. The second portion is between the first portion and the third portion. The first, second, and third portions are horizontally displaced from each other. The third portion is heated from one or more heaters located in the third portion. Hydrocarbons are produced from the third portion of the formation. The hydrocarbons include at least some hydrocarbons from the second portion of the formation.

  4. Study progress on acute ethylene oxide poisoning%急性环氧乙烷中毒研究进展

    Institute of Scientific and Technical Information of China (English)

    张毅南; 徐春茹; 张国辉; 王岩

    2010-01-01

    @@ 环氧乙烷(Ethylene oxide,CAS No.9003-56-9),分子式(CH2)2O,别名氧化乙烯、1,2-环氧乙烷、恶烷,工业上主要用作溶剂、增效剂及高能原料,常作为合成乙二醇等的化工原料.

  5. Nanostructured bismuth vanadate-based materials for solar-energy-driven water oxidation: a review on recent progress

    Science.gov (United States)

    Huang, Zhen-Feng; Pan, Lun; Zou, Ji-Jun; Zhang, Xiangwen; Wang, Li

    2014-11-01

    Water oxidation is the key step for both photocatalytic water splitting and CO2 reduction, but its efficiency is very low compared with the photocatalytic reduction of water. Bismuth vanadate (BiVO4) is the most promising photocatalyst for water oxidation and has become a hot topic for current research. However, the efficiency achieved with this material to date is far away from the theoretical solar-to-hydrogen conversion efficiency, mainly due to the poor photo-induced electron transportation and the slow kinetics of oxygen evolution. Fortunately, great breakthroughs have been made in the past five years in both improving the efficiency and understanding the related mechanism. This review is aimed at summarizing the recent experimental and computational breakthroughs in single crystals modified by element doping, facet engineering, and morphology control, as well as macro/mesoporous structure construction, and composites fabricated by homo/hetero-junction construction and co-catalyst loading. We aim to provide guidelines for the rational design and fabrication of highly efficient BiVO4-based materials for water oxidation.

  6. Nanostructured bismuth vanadate-based materials for solar-energy-driven water oxidation: a review on recent progress.

    Science.gov (United States)

    Huang, Zhen-Feng; Pan, Lun; Zou, Ji-Jun; Zhang, Xiangwen; Wang, Li

    2014-11-06

    Water oxidation is the key step for both photocatalytic water splitting and CO₂ reduction, but its efficiency is very low compared with the photocatalytic reduction of water. Bismuth vanadate (BiVO₄) is the most promising photocatalyst for water oxidation and has become a hot topic for current research. However, the efficiency achieved with this material to date is far away from the theoretical solar-to-hydrogen conversion efficiency, mainly due to the poor photo-induced electron transportation and the slow kinetics of oxygen evolution. Fortunately, great breakthroughs have been made in the past five years in both improving the efficiency and understanding the related mechanism. This review is aimed at summarizing the recent experimental and computational breakthroughs in single crystals modified by element doping, facet engineering, and morphology control, as well as macro/mesoporous structure construction, and composites fabricated by homo/hetero-junction construction and co-catalyst loading. We aim to provide guidelines for the rational design and fabrication of highly efficient BiVO₄-based materials for water oxidation.

  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. Cost-effectiveness of anti-oxidant vitamins plus zinc treatment to prevent the progression of intermediate age-related macular degeneration. A Singapore perspective.

    Science.gov (United States)

    Saxena, Nakul; George, Pradeep Paul; Heng, Bee Hoon; Lim, Tock Han; Yong, Shao Onn

    2015-06-01

    To determine if providing high dose anti-oxidant vitamins and zinc treatment age-related eye disease study (AREDS formulation) to patients with intermediate age-related macular degeneration (AMD) aged 40-79 years from Singapore is cost-effective in preventing progression to wet AMD. A hypothetical cohort of category 3 and 4 AMD patients from Singapore was followed for 5 calendar years to determine the number of patients who would progress to wet AMD given the following treatment scenarios: (a) AREDS formulation or placebo followed by ranibizumab (as needed) for wet AMD. (b) AREDS formulation or placebo followed by bevacizumab (monthly) for wet AMD. (c) AREDS formulation or placebo followed by aflibercept (VIEW I and II trial treatment regimen). Costs were estimated for the above scenarios from the providers' perspective, and cost-effectiveness was measured by cost per disability-adjusted life year (DALY) averted with a disability weight of 0.22 for wet AMD. The costs were discounted at an annual rate of 3%. Over 5400 patients could be prevented from progressing to wet AMD cumulatively if AREDS formulation were prescribed. AREDS formulation followed by ranibizumab was cost-effective compared to placebo-ranibizumab or placebo-aflibercept combinations (cost per DALY averted: SGD$23,662.3 and SGD$21,138.8, respectively). However, bevacizumab (monthly injections) alone was more cost-effective compared to AREDS formulation followed by bevacizumab. Prophylactic treatment with AREDS formulation for intermediate AMD patients followed by ranibizumab or for patients who progressed to wet AMD was found to be cost-effective. These findings have implications for intermediate AMD screening, treatment and healthcare planning in Singapore.

  9. Cost-effectiveness of anti-oxidant vitamins plus zinc treatment to prevent the progression of intermediate age-related macular degeneration. A Singapore perspective

    Directory of Open Access Journals (Sweden)

    Nakul Saxena

    2015-01-01

    Full Text Available Purpose: To determine if providing high dose anti-oxidant vitamins and zinc treatment age-related eye disease study (AREDS formulation to patients with intermediate age-related macular degeneration (AMD aged 40-79 years from Singapore is cost-effective in preventing progression to wet AMD. Methods: A hypothetical cohort of category 3 and 4 AMD patients from Singapore was followed for 5 calendar years to determine the number of patients who would progress to wet AMD given the following treatment scenarios: (a AREDS formulation or placebo followed by ranibizumab (as needed for wet AMD. (b AREDS formulation or placebo followed by bevacizumab (monthly for wet AMD. (c AREDS formulation or placebo followed by aflibercept (VIEW I and II trial treatment regimen. Costs were estimated for the above scenarios from the providers′ perspective, and cost-effectiveness was measured by cost per disability-adjusted life year (DALY averted with a disability weight of 0.22 for wet AMD. The costs were discounted at an annual rate of 3%. Results: Over 5400 patients could be prevented from progressing to wet AMD cumulatively if AREDS formulation were prescribed. AREDS formulation followed by ranibizumab was cost-effective compared to placebo-ranibizumab or placebo-aflibercept combinations (cost per DALY averted: SGD$23,662.3 and SGD$21,138.8, respectively. However, bevacizumab (monthly injections alone was more cost-effective compared to AREDS formulation followed by bevacizumab. Conclusion: Prophylactic treatment with AREDS formulation for intermediate AMD patients followed by ranibizumab or for patients who progressed to wet AMD was found to be cost-effective. These findings have implications for intermediate AMD screening, treatment and healthcare planning in Singapore.

  10. 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.

  11. Inhibition of the aryl hydrocarbon receptor prevents Western diet-induced obesity. Model for AHR activation by kynurenine via oxidized-LDL, TLR2/4, TGFβ, and IDO1.

    Science.gov (United States)

    Moyer, Benjamin J; Rojas, Itzel Y; Kerley-Hamilton, Joanna S; Hazlett, Haley F; Nemani, Krishnamurthy V; Trask, Heidi W; West, Rachel J; Lupien, Leslie E; Collins, Alan J; Ringelberg, Carol S; Gimi, Barjor; Kinlaw, William B; Tomlinson, Craig R

    2016-06-01

    Obesity is an increasingly urgent global problem, yet, little is known about its causes and less is known how obesity can be effectively treated. We showed previously that the aryl hydrocarbon receptor (AHR) plays a role in the regulation of body mass in mice fed Western diet. The AHR is a ligand-activated nuclear receptor that regulates genes involved in a number of biological pathways, including xenobiotic metabolism and T cell polarization. This study was an investigation into whether inhibition of the AHR prevents Western diet-based obesity. Male C57Bl/6J mice were fed control and Western diets with and without the AHR antagonist α-naphthoflavone or CH-223191, and a mouse hepatocyte cell line was used to delineate relevant cellular pathways. Studies are presented showing that the AHR antagonists α-naphthoflavone and CH-223191 significantly reduce obesity and adiposity and ameliorates liver steatosis in male C57Bl/6J mice fed a Western diet. Mice deficient in the tryptophan metabolizing enzyme indoleamine 2,3-dioxygenase 1 (IDO1) were also resistant to obesity. Using an AHR-directed, luciferase-expressing mouse hepatocyte cell line, we show that the transforming growth factor β1 (TGFβ1) signaling pathway via PI3K and NF-κB and the toll-like receptor 2/4 (TLR2/4) signaling pathway stimulated by oxidized low-density lipoproteins via NF-κB, each induce luciferase expression; however, TLR2/4 signaling was significantly reduced by inhibition of IDO1. At physiological levels, kynurenine but not kynurenic acid (both tryptophan metabolites and known AHR agonists) activated AHR-directed luciferase expression. We propose a hepatocyte-based model, in which kynurenine production is increased by enhanced IDO1 activity stimulated by TGFβ1 and TLR2/4 signaling, via PI3K and NF-κB, to perpetuate a cycle of AHR activation to cause obesity; and inhibition of the AHR, in turn, blocks the cycle's output to prevent obesity. The AHR with its broad ligand binding specificity

  12. 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.

  13. 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.

  14. Progress in bismuth molybdenum composite oxide%铋钼复合氧化物的研究进展

    Institute of Scientific and Technical Information of China (English)

    程琳; 李榕; 甄强

    2013-01-01

    In this work,a variety of the preparation methods of bismuth molybdenum composite oxides have been summarized,such as solid state reaction,precipitation,sol-gel,hydrothermal method,spray-drying and so on.The advantages and disadvantages of these methods were also commented.Then,the application of bis-muth molybdenum composite oxides were introduced,including oxidation catalysts,photocatalysts and electro-lyte materials,as well as the effect of structure,morphology,composition on the properties of the material. The development direction of the preparation techniques,components,structure and morphology were pointed out,in view of its application field.%综述了多种铋钼复合氧化物的制备方法:固相反应法、沉淀法、溶胶-凝胶法、水热法以及喷雾干燥法等,分析了这些方法的优缺点。同时综述了铋钼复合氧化物在氧化反应催化、光催化、电解质材料等领域的应用以及材料的结构、形貌对于其性能的影响。针对铋钼复合氧化物不同的应用领域提出了制备技术、材料组分和结构与形貌的发展方向。

  15. 异丙苯催化氧化的研究进展%PROGRESS IN THE RESEARCH OF CUMENE OXIDATION REACTION

    Institute of Scientific and Technical Information of China (English)

    郭建维; 王乐夫; 纪红兵; 黄仲涛; 崔英德

    2001-01-01

    对传统的异丙苯氧化工艺及反应流程进行了简单评述,指出了该工艺存在的缺陷,并对近年来异丙苯氧化的反应工艺、催化体系等研究成果进行了总结归纳和综合评述,在此基础上对这一领域今后的研究方向和发展趋势进行了预测。%The traditional technology and the typical industrial process of cumene oxidation reaction were introduced and commented in this paper, including shortages of this intraditional technology and process. The progresses on reaction conditions, catalytic systems for cumene oxidition were summarized and reviewed. Finally, the possible directions for future research in this area were forcasted.

  16. 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.

  17. Genetics of bacteria that oxidize one-carbon compounds. Progress report, March 1, 1991--June 30, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, R.S.

    1993-12-31

    In the past several years researchers have identified at least 20 genes whose products were required for the oxidation of methanol to formaldehyde in three different facultative methylotrophic bacteria. These genes include structural genes for a cytochrome c{sub L} (mox G) and is a specific electron acceptor for methanol dehydrogenase (MDH), and the two structural genes that encode the large subunit (mox F) and smaller subunit (mox I) of MDH. Other genes are required for the synthesis of the prosthetic group of MDH, Pyrroloquinoline quinone (PQQ), and proteins required for assembly of the active MDH in the periplasm. Three genes are believed to be required for incorporation of calcium into the MDH tetramer. The principal investigator`s group has studied the regulation of methanol oxidation in the pink-pigmented-facultative methylotroph Methylobacterium organophilum XX. The authors have mapped several genes and have sequenced the mox F gene and sequences upstream of mox F. The authors had tentatively identified several genes required for the transcription of the MDH structural genes in three methylotrophs. In the previous proposal, the P.I. proposed to establish an in-vitro transcription/translation system to study the function of the regulatory gene products. Further studies demonstrated that the regulation of transcription of these genes was far more complex than imagined at that time and the research plan was modified to determine the number and function of the regulatory genes using genetic approaches.

  18. 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

  19. 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.

  20. The research progress of Li-ion battery separators with inorganic oxide nanoparticles by electrospinning: A mini review

    Science.gov (United States)

    Chen, Hong-Li; Jiao, Xiao-Ning; Zhou, Jin-Tao

    2016-09-01

    The technology of Lithium-ion battery (LIB) separator has become more and more mature. But there are still many problems that needed to be resolved. For example, its mechanical strength is low relatively, thermal stability is bad and the porosity and electrochemical performance are imperfect. This paper introduces modification of electrospinning LIB separator from the way of adding nanoparticles, including SiO2, TiO2, Al2O3 and copper titanate oxide, etc. And addition methods include dissolving in dispersant, dissolving in polymer solution, coating and in situ method. The modified membranes possess higher ionic conductivity which can reach to the level of 10-3s/cm.

  1. [Fundamental studies in oxidation-reduction in relation to water photolysis]. Progress report, November 1, 1990--October 25, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Hurst, J.K.

    1991-12-31

    Our research has been directed at understanding three elementary processes that are central to developing membrane-based integrated chemical systems for water photolysis. These are: (1) the role of interfaces in charge separation/recombination reactions, (2) pathways for transmembrane charge separation, and (3) mechanisms of water oxidation catalyzed by transition metal coordination complexes. Historically, the chemical dynamics of each of these processes has been poorly understood, with numerous unresolved issues and conflicting viewpoints appearing in the literature. Our experimental systems comprise primarily unilamellar vesicles that have been doped with amphiphilic viologens which function as transmembrane charge relays. These systems are experimentally highly tractable and versatile, are conceptually simple, and have been widely used in a variety of organized microphase media and prototypic devices. As such, they are ideal for identifying basic principles governing reactivity.

  2. Recent Progress on Advanced Materials for Solid-Oxide Fuel Cells Operating Below 500 °C.

    Science.gov (United States)

    Zhang, Yuan; Knibbe, Ruth; Sunarso, Jaka; Zhong, Yijun; Zhou, Wei; Shao, Zongping; Zhu, Zhonghua

    2017-06-19

    Solid-oxide fuel cells (SOFCs) are electricity generators that can convert the chemical energy in various fuels directly to the electric power with high efficiency. Recent advances in materials and related key components for SOFCs operating at ≈500 °C are summarized here, with a focus on the materials, structures, and techniques development for low-temperature SOFCs, including the analysis of most of the critical parameters affecting the electrochemical performance of the electrolyte, anode, and cathode. New strategies, such as thin-film deposition, exsolution of nanoparticles from perovskites, microwave plasma heating, and finger-like channeled electrodes, are discussed. These recent developments highlight the need for electrodes with higher activity and electrolytes with greater conductivity to generate a high electrochemical performance at lower temperatures. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Telmisartan reduces progressive oxidative stress and phosphorylated α-synuclein accumulation in stroke-resistant spontaneously hypertensive rats after transient middle cerebral artery occlusion.

    Science.gov (United States)

    Sato, Kota; Yamashita, Toru; Kurata, Tomoko; Lukic, Violeta; Fukui, Yusuke; Hishikawa, Nozomi; Deguchi, Kentaro; Abe, Koji

    2014-07-01

    Telmisartan is an angiotensin receptor blocker with high lipid solubility, also called metabosartan, which exerts a special protective effect on both acute brain damage and chronic neurodegeneration. We examined the effects of telmisartan on oxidative stress by advanced glycation end product (AGE) and 4-hydroxynonenal (4-HNE) assays and the accumulation of phosphorylated α-synuclein (pSyn) in the brain of stroke-resistant spontaneously hypertensive rats (SHR-SR). At the age of 12 weeks, SHR-SR received transient middle cerebral artery occlusion (tMCAO) for 90 minutes and were divided into the following 3 groups: the vehicle group, the low-dose telmisartan group (.3 mg/kg/day), and the high-dose telmisartan group (3 mg/kg/day, postoperatively). Immunohistologic analysis was performed when rats were 6, 12, and 18 months old. AGE, 4-HNE, and pSyn-positive cells (per square millimeter) increased with age in the cerebral cortex and hippocampus of the vehicle group, in the low-dose telmisartan group, these parameters decreased without lowering blood pressure (BP), and in the high-dose telmisartan group, these parameters increased with lowering BP. The present study suggests that a persistent hypertension after tMCAO caused a progressive oxidative stress with the abnormal accumulation of pSyn, and that telmisartan reduced oxidative stress and the accumulation of pSyn without lowering BP (low dose) or improved these conditions with a reduction in BP (high dose) via its pleiotropic effects through a potential peroxisome proliferator-activated receptor gamma stimulation in the brain of SHR-SR. Copyright © 2014. Published by Elsevier Inc.

  4. SYNTHESIS OF PARTIAL-OXYGENATED HYDROCARBONS USING PHOTOCATALYSIS IN A LAMINAR FALLING FILM SLURRY REACTOR

    Science.gov (United States)

    The search for "Green" alternative processes for the oxidation of hydrocarbons selectively to partial oxygenates has been the subject of intense chemical research for many years. The USEPA is currently investigating an alternative synthesis pathway for the production of alcoho...

  5. SYNTHESIS OF PARTIALLY-OXYGENATED HYDROCARBONS USING PHOTOCATALYSIS IN A LAMINAR FALLING FILM SLURRY REACTOR

    Science.gov (United States)

    The search for "Green" alternative processes for the oxidation of hydrocarbons selectively to partial oxygenates has been the subject of intense chemical research for many years. The USEPA is currently investigating an alternative synthesis pathway for the production of alcoho...

  6. 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.

  7. 土壤中微生物对多环芳烃的降解及其生物修复的研究进展%Research Progress on Degradation of Polycyclic Aromatic Hydrocarbons and the Bioremediation Via Soil Microorganism

    Institute of Scientific and Technical Information of China (English)

    杨峰; 钟鸣; 白鹏; 马慧

    2011-01-01

    多环芳烃是一类在环境中普遍存在的有机污染物,微生物降解是多环芳烃(PAHs)降解的主要途径.文中主要介绍PAHs的降解菌,降解机理和PAHs的生物修复方面的研究进展.这些进展可为降解菌株的分子及遗传机制研究提供理论依据,将促进通过基因工程优化降解菌、更有效地检测PAHs环境污染及实现PAHs污染的生物修复.%rolycychc aromatic hydrocarbons (rAHs) are ubiquitous environmental pollutants, its main degradation path was completed by microorganism. Advances in the screening of PAHs degrading strains, their bio-degradation mechanisms and the PAHs bioremediation are introduced. It is likely that the new information will promote further research and applications of microbial PAHs biodegradation technology.

  8. Prediction of Petroleum Hydrocarbon Bioavailability in Contaminated Soils and Sediments

    NARCIS (Netherlands)

    Cuypers, M.P.; Clemens, R.; Grotenhuis, J.T.C.; Rulkens, W.H.

    2001-01-01

    Recently, several laboratory methods have been developed for the prediction of contaminant bioavailability. So far, none of these methods has been extensively tested for petroleum hydrocarbons. In the present study we investigated solid-phase extraction and persulfate oxidation for the prediction of

  9. Recent progress in oxide scintillation crystals development by low-thermal gradient Czochralski technique for particle physics experiments

    Science.gov (United States)

    Shlegel, V. N.; Borovlev, Yu. A.; Grigoriev, D. N.; Grigorieva, V. D.; Danevich, F. A.; Ivannikova, N. V.; Postupaeva, A. G.; Vasiliev, Ya. V.

    2017-08-01

    Modern particle physics experiments call for high performance scintillation detectors with unique properties: radiation-resistant in high energy and astrophysics, highly radiopure, containing certain elements or enriched isotopes in astroparticle physics. The low-thermal gradient Czochralski (LTG CZ) crystal growth technique provides excellent quality large volume radiopure crystal scintillators. Absence of thermoelastic stress in the crystal and overheating of the melt in the LTG CZ method is particularly significant in production of crystalline materials with strong thermal anisotropic properties and low mechanical strength, with a very high yield of crystalline boules and low losses of initial charge, crucially important in production of crystal scintillators from enriched isotopes for double beta decay experiments. Here we discuss progress in development of the well known scintillators (Bi4Ge3O12 (BGO), CdWO4, ZnWO4, CaMoO4, PbMoO4), as well as R&D of new materials (ZnMoO4, Li2MoO4, Na2Mo2O7) for the next generation experiments in particle physics.

  10. Resveratrol retards progression of diabetic nephropathy through modulations of oxidative stress, proinflammatory cytokines, and AMP-activated protein kinase

    Directory of Open Access Journals (Sweden)

    Yen Tzung-Hai

    2011-06-01

    Full Text Available Abstract Background Diabetic nephropathy (DN has been recognized as the leading cause of end-stage renal disease. Resveratrol (RSV, a polyphenolic compound, has been indicated to possess an insulin-like property in diabetes. In the present study, we aimed to investigate the renoprotective effects of RSV and delineate its underlying mechanism in early-stage DN. Methods The protective effects of RSV on DN were evaluated in streptozotocin (STZ-induced diabetic rats. Results The plasma glucose, creatinine, and blood urea nitrogen were significantly elevated in STZ-induced diabetic rats. RSV treatment markedly ameliorated hyperglycemia and renal dysfunction in STZ-induced diabetic rats. The diabetes-induced superoxide anion and protein carbonyl levels were also significantly attenuated in RSV-treated diabetic kidney. The AMPK protein phosphorylation and expression levels were remarkably reduced in diabetic renal tissues. In contrast, RSV treatment significantly rescued the AMPK protein expression and phosphorylation compared to non-treated diabetic group. Additionally, hyperglycemia markedly enhanced renal production of proinflammatory cytokine IL-1β. RSV reduced IL-1β but increased TNF-α and IL-6 levels in the diabetic kidneys. Conclusions Our findings suggest that RSV protects against oxidative stress, exhibits concurrent proinflammation and anti-inflammation, and up-regulates AMPK expression and activation, which may contribute to its beneficial effects on the early stage of DN.

  11. Carbon mediated catalysis:A review on oxidative dehydrogenation

    Institute of Scientific and Technical Information of China (English)

    De Chen; Anders Holmen; Zhijun Sui; Xinggui Zhou

    2014-01-01

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

  12. 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.

  13. 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.

  14. Abiogenic formation of alkanes in the Earth's crust as a minor source for global hydrocarbon reservoirs

    Science.gov (United States)

    Sherwood Lollar, B.; Westgate, T. D.; Ward, J. A.; Slater, G. F.; Lacrampe-Couloume, G.

    2002-04-01

    Natural hydrocarbons are largely formed by the thermal decomposition of organic matter (thermogenesis) or by microbial processes (bacteriogenesis). But the discovery of methane at an East Pacific Rise hydrothermal vent and in other crustal fluids supports the occurrence of an abiogenic source of hydrocarbons. These abiogenic hydrocarbons are generally formed by the reduction of carbon dioxide, a process which is thought to occur during magma cooling and-more commonly-in hydrothermal systems during water-rock interactions, for example involving Fischer-Tropsch reactions and the serpentinization of ultramafic rocks. Suggestions that abiogenic hydrocarbons make a significant contribution to economic hydrocarbon reservoirs have been difficult to resolve, in part owing to uncertainty in the carbon isotopic signatures for abiogenic versus thermogenic hydrocarbons. Here, using carbon and hydrogen isotope analyses of abiogenic methane and higher hydrocarbons in crystalline rocks of the Canadian shield, we show a clear distinction between abiogenic and thermogenic hydrocarbons. The progressive isotopic trends for the series of C1-C4 alkanes indicate that hydrocarbon formation occurs by way of polymerization of methane precursors. Given that these trends are not observed in the isotopic signatures of economic gas reservoirs, we can now rule out the presence of a globally significant abiogenic source of hydrocarbons.

  15. SchiffBase Dinuclear Complex Catalyst for Oxidation of Cyclohexene with Molecular Oxygen

    Institute of Scientific and Technical Information of China (English)

    SHAO; DongXu

    2001-01-01

    In the past decades, the oxidation of hydrocarbons by transition metal complexes has been studied extensively. The current progress of the research on synthetic quasiporphyrin catalysts has led to the development of several systems that are able to reproduce the hene-enzyme mediated oxygenation and oxidation reactions[1]. In our group[2,51, the mononuclear complexes of amino acid Schiff base have been synthesized and their catalytic oxidation has been studied. In this paper, two dinuclear complexes, such as Salicylidence-β-alanine-Co(II)-Cu(II) and Salicylidence-β-alanine-Co(II)Mn(II), were prepared with amino acid Schiff bases and metal ions. In the presence of these dinuclear complexes, cyclohexene was effectively oxidized under 1 atm of molecular oxygen without any coreductants. The allylic hydroperoxide was obtained as an important product, which suggested a clear allylic pathway of oxidation of cyclohexene.  ……

  16. Research Progress on the Bioremediation Technology of Polycyclic Aromatic Hydrocarbons Contaminated Soil%多环芳烃污染土壤生物修复技术研究进展

    Institute of Scientific and Technical Information of China (English)

    杨辉; 王海霞; 李晓军; 毛华军; 吴海燕; 于秀娜; 罗宏宇

    2011-01-01

    With the biomass fuels widely used, the area and extent of the PAH-Contaminated soil increased quickly. Thus, the study on the remediation technology of PAH-Contaminated soil is becoming extremely urgent. Compared with physical and chemical remediation, bioremediation is cheap, effective and secondary pollution-free. Plant-microbial remediation system is the most effective technology with the largest market potential. The paper introduces in details the mechanism and application of microbial and plant-microbial remediation, and forecasts the development tendency of the bioremediation of polyeyclic aromatic hydrocarbons contaminated soil.%多环芳烃污染土壤的面积伴随着生物质燃料的广泛应用不断增加,污染程度亦随之增强,研究污染土壤高效修复方法已刻不容缓.生物修复相对于物理和化学修复具有费用低、效果好、不产生二次污染等优点.植物-微生物联合修复体系则是其中最为高效、最具市场潜力的修复技术.详细介绍了微生物修复与植物-微生物联合修复技术的机理及应用, 并展望了多环芳烃污染土壤生物修复的发展趋势.

  17. TOPICAL REVIEW: Zinc oxide nanorod based photonic devices: recent progress in growth, light emitting diodes and lasers

    Science.gov (United States)

    Willander, M.; Nur, O.; Zhao, Q. X.; Yang, L. L.; Lorenz, M.; Cao, B. Q.; Zúñiga Pérez, J.; Czekalla, C.; Zimmermann, G.; Grundmann, M.; Bakin, A.; Behrends, A.; Al-Suleiman, M.; El-Shaer, A.; Che Mofor, A.; Postels, B.; Waag, A.; Boukos, N.; Travlos, A.; Kwack, H. S.; Guinard, J.; LeSi Dang, D.

    2009-08-01

    Zinc oxide (ZnO), with its excellent luminescent properties and the ease of growth of its nanostructures, holds promise for the development of photonic devices. The recent advances in growth of ZnO nanorods are discussed. Results from both low temperature and high temperature growth approaches are presented. The techniques which are presented include metal-organic chemical vapour deposition (MOCVD), vapour phase epitaxy (VPE), pulse laser deposition (PLD), vapour-liquid-solid (VLS), aqueous chemical growth (ACG) and finally the electrodeposition technique as an example of a selective growth approach. Results from structural as well as optical properties of a variety of ZnO nanorods are shown and analysed using different techniques, including high resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM), photoluminescence (PL) and cathodoluminescence (CL), for both room temperature and for low temperature performance. These results indicate that the grown ZnO nanorods possess reproducible and interesting optical properties. Results on obtaining p-type doping in ZnO micro- and nanorods are also demonstrated using PLD. Three independent indications were found for p-type conducting, phosphorus-doped ZnO nanorods: first, acceptor-related CL peaks, second, opposite transfer characteristics of back-gate field effect transistors using undoped and phosphorus doped wire channels, and finally, rectifying I-V characteristics of ZnO:P nanowire/ZnO:Ga p-n junctions. Then light emitting diodes (LEDs) based on n-ZnO nanorods combined with different technologies (hybrid technologies) are suggested and the recent electrical, as well as electro-optical, characteristics of these LEDs are shown and discussed. The hybrid LEDs reviewed and discussed here are mainly presented for two groups: those based on n-ZnO nanorods and p-type crystalline substrates, and those based on n-ZnO nanorods and p-type amorphous substrates. Promising electroluminescence

  18. Inhibition of Pancreatic Intraepithelial Neoplasia Progression to Carcinoma by Nitric Oxide-Releasing Aspirin in p48Cre/+-LSL-KrasG12D/+ Mice

    Directory of Open Access Journals (Sweden)

    Chinthalapally V. Rao

    2012-09-01

    Full Text Available Nitric oxide-releasing aspirin (NO-aspirin represents a novel class of promising chemopreventive agents. Unlike conventional nonsteroidal anti-inflammatory drugs, NO-aspirin seems to be free of adverse effects while retaining the beneficial activities of its parent compound. The effect of NO-aspirin on pancreatic carcinogenesis was investigated by assessing the development of precursor pancreatic lesions and adenocarcinomas in KrasG12D/+ transgenic mice that recapitulate human pancreatic cancer progression. Six-week-old male p48Cre/+-LSL-KrasG12D/+ transgenic mice (20 per group were fed diets containing 0, 1000, or 2000 ppm NO-aspirin. The development of pancreatic tumors was monitored by positron emission tomography imaging. All mice were killed at the age of 41 weeks and assessed for pancreatic intraepithelial neoplasia (PanIN and pancreatic ductal adenocarcinoma (PDAC and for molecular changes in the tumors. Our results reveal that NO-aspirin at 1000 and 2000 ppm significantly suppressed pancreatic tumor weights, PDAC incidence, and carcinoma in situ (PanIN-3 lesions. The degree of inhibition of PanIN-3 and carcinoma was more pronounced with NO-aspirin at 1000 ppm (58.8% and 48%, respectively than with 2000 ppm (47% and 20%, respectively. NO-aspirin at 1000 ppm significantly inhibited the spread of carcinoma in the pancreas (∼97%; P < .0001. Decreased expression of cyclooxygenase (COX; with ∼42% inhibition of total COX activity, inducible nitric oxide synthase, proliferating cell nuclear antigen, Bcl-2, cyclin D1, and β-catenin was observed, with induction of p21, p38, and p53 in the pancreas of NO-aspirin-treated mice. These results suggest that low-dose NO-aspirin possesses inhibitory activity against pancreatic carcinogenesis by modulating multiple molecular targets.

  19. Research Progress About Bioremediation of Polycyclic Aromatic Hydrocarbons Contaminated Soil with Immobilized Microorganism Technique%固定化微生物技术修复PAHs污染土壤的研究进展

    Institute of Scientific and Technical Information of China (English)

    钱林波; 元妙新; 陈宝梁

    2012-01-01

    Polycyclic aromatic hydrocarbons(PAHs),ubiquitous in the environment,are a typical organic pollutants.Green remediation of PAHs contaminated soil has become a hot research focus.As a novel microbial remediation technique,the immobilized microorganism technology(IMT) is attracting more and more attention to restore organic contaminated soil.This paper reviewed bioremediation of polycyclic aromatic hydrocarbons contaminated soil with immobilized microorganism technique.The IMT remediation principles,selection of the immobilized carries,screening of efficient PAHs-degradation microorganism,and methods of microorganism immobilized were summarized.The research trends and currently existing problems in IMT remediation of contaminated soil were prospected.%多环芳烃(PAHs)是环境中普遍存在的一类典型有机污染物,绿色修复PAHs污染土壤已成为国内外环境和土壤界共同关注的热点问题之一.作为一种新型的微生物修复技术,固定化微生物修复有机污染土壤正受到越来越多的关注,国内外相关研究刚刚开始.本文重点评述了近几年国内外有关固定化微生物技术修复PAHs污染土壤的最新进展,总结了固定化微生物技术的修复原理、微生物固定化载体的选择、高效降解菌的筛选、固定化方法及影响因素等方面,并提出今后的发展方向,为我国开展固定化微生物技术修复有机污染土壤的研究提供参考.

  20. 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.

  1. Membranous nephropathy following exposure to volatile hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Ehrenreich, T.; Yunis, S.L.; Churg, J.

    1977-01-01

    Excessive exposure to solvents has long been known to cause renal tubular disease in man. Recently, the occurrence of glomerular disease such as Goodpasture's syndrome with proliferative and extracapillary glomerulonephritis has been related to hydrocarbon exposure. This report concerns four patients with membranous nephropathy who had a history of prolonged exposure to a number of volatile hydrocarbons. Membranous nephropathy is a chronic renal disease involving glomeruli and occurring principally in adults. Its clinical onset is insidious and is manifested by proteinuria or edema. Proteinuria is the hallmark of the disease and may be present for many years without symptoms. It is often a slowly progressive disease. About one-fourth of the patients improve clinically and lose their proteinuria, while up to one-fourth develop renal failure. The glomerular capillary wall lesions are distinctive, contain deposits of immunoglobulin and complement considered to represent immune-complexes, and show a morphological progression from early Stage I to late Stage IV. While in most cases there is no known etiology, in some patients the disease has been deemed to be secondary to specific diseases or agents such as infections, neoplasms, or chemicals. The four cases described fall into this last category.

  2. 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.

  3. 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

  4. Hydrocarbon Receptor Pathway in Dogs

    NARCIS (Netherlands)

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

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

  5. A review on the progress of advanced oxidation treatment of pesticide wastewater%高级氧化法处理农药废水的研究进展

    Institute of Scientific and Technical Information of China (English)

    王龙辉; 杜世章; 蒋连; 成梦凡; 秦海利

    2016-01-01

    This paper reviews resent development for advanced oxidation treatment technologies such as Fenton technology,photo-catalytic oxidation technology,ultrasonic degradation,wet oxidation, supercritical water oxidation,electro-catalytic oxidation technology etc. ,and introduces,together with the summary of the resent progress on pesticide wastewater treatment using advanced oxidation technologies,the principles and applications of various advanced oxidation technologies,and propo-ses problems and the potential for future development. of organic wastewater treatment using ad-vanced oxidation technologies.%综述了近几年研究的高级氧化技术,主要包括Fenton技术、光催化氧化技术、超声降解法、超临界水氧化法以及电催化氧化技术等。结合高级氧化法处理农药废水的研究进展,介绍了各种高级氧化技术的原理研究和应用方面取得的成果,提出高级氧化技术在处理有机废水中存在的问题以及未来发展的潜力。

  6. Chlorinated Hydrocarbon Degradation in Plants: Mechanisms and Enhancement of Phytoremediation of Groundwater Contamination

    Energy Technology Data Exchange (ETDEWEB)

    Stuart Strand

    2004-09-27

    The research objectives for this report are: (1) Transform poplar and other tree species to extend and optimize chlorinated hydrocarbon (CHC) oxidative activities. (2) Determine the mechanisms of CHC oxidation in plants. (3) Isolate the genes responsible for CHC oxidation in plants. We have made significant progress toward an understanding of the biochemical mechanism of CHC transformation native to wild-type poplar. We have identified chloral, trichloroethanol, trichloroacetic acid, and dichloroacetic acid as products of TCE metabolism in poplar plants and in tissue cultures of poplar cells.(Newman et al. 1997; Newman et al. 1999) Use of radioactively labeled TCE showed that once taken up and transformed, most of the TCE was incorporated into plant tissue as a non-volatile, unextractable residue.(Shang et al. 2001; Shang and Gordon 2002) An assay for this transformation was developed and validated using TCE transformation by poplar suspension cells. Using this assay, it was shown that two different activities contribute to the fixation of TCE by poplar cells: one associated with cell walls and insoluble residues, the other associated with a high molecular weight, heat labile fraction of the cell extract, a fixation that was apparently catalyzed by plant enzymes.

  7. 铁络合物催化类Fenton氧化研究进展%Progress in the research on iron complex catalyzed Fenton-like oxidation

    Institute of Scientific and Technical Information of China (English)

    郗丽娟; 曹天静; 李大鹏; 杨榕; 徐淑芬; 廖霞; 张瑛洁

    2011-01-01

    The progress in iron complex catalyzed Fenton-like oxidation is reviewed. Compared with iron,the iron complex has a higher catalytic activity to improve the removal rate of organic matter from water. The homogeneous Fenton-like catalyzed by iron complex may bring a problem of removing metallic ions in subsequent process, so the heterogeneous Fenton-like catalyzed by iron complex has a better future. The current research situation of the Fenton-like catalyzed by iron complex loaded on resin is introduced emphatically and the reactive species in the Fenton-like catalyzed by iron complex is discussed.%综述了铁络合物催化类Fenton氧化的研究进展.铁络合物与铁相比具有更高的催化活性,可提高水中有机物的去除效果.均相类Fenton存在后续金属离子的去除问题,因此铁络合物作为催化剂的多相催化类Fenton氧化具有更好的应用前景.重点介绍了高分子负载铁络合物催化类Fenton氧化降解水中有机物的研究现状及铁络合物催化类Fenton氧化的反应活性物种.

  8. 锂离子电池纳米锂锰氧化物正极材料的研究进展%Research Progress in Nano-scale Lithium Manganese Oxide as Cathode Material for Lithium Ion Batteries

    Institute of Scientific and Technical Information of China (English)

    曾丽珍

    2012-01-01

    综述了近年来锂离子电池正极材料锂锰氧化物的研究现状,重点对锂锰氧化物的结构和性能的关系,尖晶石锂锰氧化物的制备以及其改性研究进行了阐述。%New progress of nanotechnology applied in lithium ion battery of lithium manganese oxide as cathode material was summarized during recent years,focusing on the relationship between structure and properties of lithium manganese oxide,the preparation methods of nanometer lithium manganese oxide materials cathode material and modification of spinel lithium manganese oxide materials were described.

  9. Assessment of the advanced oxidation process , photo-fenton, on the degradation of polyaromatics hydrocarbons contained on the aqueous part of oil in superficial sea water; Avaliacao do processo oxidativo avancado, foto-fenton, na degradacao dos hidrocarbonetos poliaromaticos contidos na fracao soluvel do petroleo em agua superficial salina

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Rita C.R. da; Silva, Valdinete L. da; Paim, Ana Paula Silveira [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Rocha, Otidene R.S. da; Duarte, Marcia M.L. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    The pollution for oil has been one of the main ambient problems of the last decades. It exists an increasing interest in the study of the destination and forms of disappearance of the constituent hydrocarbons of the oil aiming at the development of more efficient methods of removal of the same ones of the environment. With objective to evaluate the process photo-fenton, in the treatment of the contaminated saline superficial water with polyaromatics hydrocarbons (HPAs) contained in the crude oil, mounted an experiment using reactor of black light, the hydrogen peroxide as oxidant agent. After the degradation the samples had been submitted to the analysis in the GC-MS, and for the 31 specters it was observed that the best ones resulted had been gotten when mmol of H{sub 2}O{sub 2} in 8 was used h of exposition to the irradiation and with pH of the equal system the 4. In the specter of this assay the characteristic peaks of the HPAs disappear completely or appear in a lowly intensities, proving that it had rupture of aromatical rings consequently and the degradation of the same ones or that its concentrations meet below of the limit of detention of the equipment. Soon, with the gotten results it can be concluded that the POAs, in special the process photo-fenton, is presented as a viable alternative in the contaminated saline superficial water treatment with the HPAs contained in the rude oil. (author)

  10. Atomic scale simulation of carbon nanotube nucleation from hydrocarbon precursors.

    Science.gov (United States)

    Khalilov, Umedjon; Bogaerts, Annemie; Neyts, Erik C

    2015-12-22

    Atomic scale simulations of the nucleation and growth of carbon nanotubes is essential for understanding their growth mechanism. In spite of over twenty years of simulation efforts in this area, limited progress has so far been made on addressing the role of the hydrocarbon growth precursor. Here we report on atomic scale simulations of cap nucleation of single-walled carbon nanotubes from hydrocarbon precursors. The presented mechanism emphasizes the important role of hydrogen in the nucleation process, and is discussed in relation to previously presented mechanisms. In particular, the role of hydrogen in the appearance of unstable carbon structures during in situ experimental observations as well as the initial stage of multi-walled carbon nanotube growth is discussed. The results are in good agreement with available experimental and quantum-mechanical results, and provide a basic understanding of the incubation and nucleation stages of hydrocarbon-based CNT growth at the atomic level.

  11. Psychosocial risks and hydrocarbon leaks : an exploration of their relationship in the Norwegian oil and gas industry

    NARCIS (Netherlands)

    Bergh, L.I.V.; Ringstad, A.J.; Leka, S.; Zwetsloot, G.I.J.M.

    2014-01-01

    Hydrocarbon leaks have a major accident potential in the oil and gas industry. Over the years the oil and gas industry in Norway has worked hard to find means to prevent hydrocarbon leaks and is today able to report significant progress. In this context, the exploration of accidents in light of huma

  12. 光催化还原CO2的研究现状和发展前景%Research Progress in Photocatalytic Conversion of CO2 to Hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    吴聪萍; 周勇; 邹志刚

    2011-01-01

    CO2 photoreduction as typical advanced technology has been becoming one of the most promising solutions to mitigate CO2 emissions. Firstly, emission reduction and utilization of CO2 was introduced. Then the present research status of photocatalytic conversion of CO2 was reviewed, with particular attention to our recent progress on this field. The artificial photosynthesis technology helps one partially reduce atmospheric CO2 levels and fulfill the recycle utilization of CO2. Finally, challenges and prospects for further development of this field are presented.%综述了光催化还原CO2的研究进展,并重点介绍了本课题组在光催化还原CO2为碳氢燃料方面的研究工作,通过该途径可降低CO2在大气中的排放浓度,还可将CO2转化为烷烃、醇或其它有机物质,从而实现碳材料的再循环使用.最后展望了该研究领域的前景.

  13. 高级氧化技术在废水处理中的应用研究进展%Application and Progress of Advanced Oxidation Processes inWastewater Treatment

    Institute of Scientific and Technical Information of China (English)

    钟理; 詹怀宇

    2000-01-01

    探讨了高级氧化技术(Advanced Oxidation Processes,即AOPs)如:O3/H2O2,Fenton试剂均相湿式催化氧化;H2O2/UV、O3/UV、O3/H2O2/UV均相光催化氧化;多相湿式催化氧化,多相光催化氧化,多相催化和生化氧化等过程处理废水及其反应机理,论述了AOPs技术在工业废水处理方面的研究进展。%The wastewater treatment and reaction mechanism by Advanced Oxidation Processes such as homogeneous wet catalytic oxidation of O3/H2O2 and Fenton agent, homogeneous photocatalytic oxidation of H2O2/UV,O3/UV and O2/H2O2/UV, and heterogeneous wet catalytic oxidation, heterogeneous photocatalytic oxidation, heterogeneous catalytic and biochemical oxidation were explored. The investigation and progress of AOPs technique in industrial wastewater treatment were overviewed.

  14. 生物质炭中多环芳烃的潜在环境风险研究进展%Progress of the Research on Potential Environmental Risk of Polycyclic Aromatic Hydrocarbons(PAHs)in Biochar

    Institute of Scientific and Technical Information of China (English)

    李增波; 王聪颖; 蒋新; 王芳

    2016-01-01

    作为土壤改良剂和环境污染修复材料,生物质炭在近年来得以广泛应用。生物质炭制备过程中会产生一定量的多环芳烃(PAHs),对其潜在环境负面效应和风险尚缺乏应有的认识。本文总结了生物质炭中PAHs的形成机理、影响因素(包括原材料、裂解温度、裂解升温速率和保留时间等)、总量和生物有效含量及其分析方法,旨在为生物质炭在环境中的安全应用提供理论依据和技术参考。%Biochar is a kind of highly aromatic carbonized material produced through thermal decomposition of biomass under reductive conditions(i.e. in the absence of or with a limited supply of oxygen). Biochar is found to be able to play an important role in mitigating global climate change,removing pollutants from water and soil,as well as maintaining functions of ecosystems. During the pyrolytic processes of biological materials,a certain amount of organic pollutants,such as polycyclic aromatic hydrocarbons (PAHs),would form and remain on the surface of the biochar. Consequently,increasing application of biochar may bring about a certain risk to the environment. Current researches pay much attention to the positive effects biochar may have,while ignoring its potential hazards to the ecosystem. To assess environmental risk of the PAHs in biochar,it is necessary to determine the contents of total and bioavailable PAHs in biochar. At present,the following four methods,i.e. Soxhlet extraction, accelerated solvent extraction(ASE),ultrasonication extraction and thermal extraction,are available for determining total PAHs in biochar. However,the four methods were often used to determine semivolatile organic compounds in solid matrix(soil or sediment). Among the four methods,the Soxhlet extraction and ASE methods are the most commonly used ones,because of their higher recoveries of target compounds. However,when they are used to extract PAHs in biochar,PAHs recoveries depend

  15. 钇掺杂氧化锌薄膜的研究进展%Research Progress of Yttrium-Doped Zinc Oxide Thin Films

    Institute of Scientific and Technical Information of China (English)

    王丹丹; 王卿璞; 王汉斌; 江秋怡; 武丽伟; 李福杰

    2013-01-01

    In recent years,zinc oxide has been the focus of semiconductor material fields,due to its excellent photoelectric and easy doping characteristics.Rare earth element yttrium-doped zinc oxide (YZO) thin film is a new research field and the research is still in its infancy.The latest research progress on YZO transparent conductive film is reviewed.Preparation methods of the material are analyzed and compared,including sol-gel,co-precipitation,magnetron sputtering and electrochemical deposition.A particular emphasis is given to the main research results of YZO.Analysis results show that the doping of yttrium with suitable concentration can improve the lattice structure of ZnO film,enhance the strength of ultraviolet radiation,increase the visible light transmittance and reduce the resistivity.The application prospects of YZO thin film in short-wavelength light emitting,flat panel displays,solar cells and other optoelectronic devices are discussed.%氧化锌材料具有优异的光电特性,易于掺杂,近年来一直是半导体材料领域关注的热点.稀土元素钇掺杂氧化锌(YZO)薄膜属于新兴的研究方向,相关研究还处于初级阶段.评述了国内外关于YZO薄膜的最新研究进展.分析比较了该薄膜材料的主要制备方法,包括溶胶-凝胶、共沉淀、磁控溅射、电化学沉积等.着重介绍了目前YZO薄膜的主要研究成果,分析结果表明适当浓度的Y掺杂,能够改善氧化锌的晶格结构,增强紫外辐射强度,提高可见光透过率,降低电阻率.探讨了YZO透明导电薄膜在短波长发光、平板显示、太阳电池等光电器件领域的应用前景.

  16. 含铋复合氧化物可见光催化材料研究进展%Recent Progress on the Bismuth Containing Complex Oxide Photocatalysts

    Institute of Scientific and Technical Information of China (English)

    王文中; 尚萌; 尹文宗; 任佳; 周林

    2012-01-01

    Photocatalysts could utilize solar energy to remedy environmental pollutions thus attract world wide attention. Some bismuth-containing complex oxides could be activated by visible light and mineralize organic pollutants. In this paper we reviewed recent progresses on the development of Bi2WO6, BiVO4 and Bi2MoO6 photocatalysts. By controlling the particle size, morphology, crystaUinity and other microstructures via different methods, the photocata-lytic activities in the degradation of organic dyes, colorless model pollutants such as phenol and acetaldehyde, and disinfection of these visible light induced photocatalysts were greatly enhanced. Through further development, bismuth-containing complex oxides are hopeful to be applied in the field of environmental remediation.%光催化材料因可以利用太阳能净化环境,受到广泛关注.一些含铋复合氧化物半导体可直接被可见光激发,更有效地利用太阳能,实现有机污染物的矿化,成为近期光催化材料研究领域的热点之一.本文概述了Bi2WO6、BiVO4和Bi2MoO6三种常见的含铋复合氧化物可见光催化材料体系的近期研究进展.通过合成方法的优选、晶粒成核和生长的调节,实现晶粒尺寸、形貌、结晶度等微结构的控制,从而获得小尺寸、高表面积的光催化材料,无论是在有机染料、苯酚和乙醛等多种模拟污染物的矿化,还是抗菌等方面,它们皆呈现出优秀的可见光催化性能.通过进一步发展,含铋复合氧化物有望实现在环境净化领域的应用.

  17. Progress in Anodic Aluminum Oxide Microchannel Plates%阳极氧化铝微通道板研究的进展

    Institute of Scientific and Technical Information of China (English)

    张洋; 黄永刚; 刘辉; 李国恩

    2012-01-01

    微通道板(Microchannel Plates,MCP)是一种先进的电子倍增器件,在微光夜视等多个领域有着广泛的应用.传统铅硅酸盐玻璃微通道板(Lead Silicate Glass Microchannel Plates,LSG-MCP)越来越不能满足小孔径、高分辨率、环境友好等方面的要求,寻求替代产品成为研究热点.详细介绍了一种新型微通道板—阳极氧化铝微通道板(Anodic Aluminum Oxide Microchannel Plates,AAO-MCP)的研究进展,包括多孔AAO的特点、微通道的形成、功能层的制备、计算机模拟等.AAO-MCP具有孔径小、面积大、耐强磁场、工作温度范围宽等特点,应用前景广阔.最后分析了AAO-MCP存在的问题以及未来发展方向.%MicroChannel plates (MCP) are advanced electron multiplier devices, which are widely used in low-light-level night vision and other fields. The traditional lead silicate glass microchannel plates (LSG-MCP) are increasingly unable to meet the requirements of small diameter, high resolution and environment-friendness, so it is necessary to find some novel alternative materials and technology, such as anodic aluminum oxide microchannel plates (AAO-MCP). This paper describes the research progress of the AAO-MCP in details, including the characteristics of the porous AAO, the forming of microchannel, functional film preparation and computer simulation. AAO-MCP has some advantages, such as smaller channel diameter, large area, low sensitivity to strong magnetic field, and wide operating temperature range. Finally, the most difficult problems in AAO-MCP and the development in the future are presented.

  18. A case study of the intrinsic bioremediation of petroleum hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Barker, G.W.; Raterman, K.T.; Fisher, J.B.; Corgan, J.M. [and others

    1995-12-31

    Condensate liquids have been found to contaminate soil and groundwater at two gas production sites in the Denver Basin operated by Amoco Production Co. These sites have been closely monitored since July 1993 to determine whether intrinsic aerobic or anaerobic bioremediation of hydrocarbons occurs at a sufficient rate and to an adequate endpoint to support a no-intervention decision. Groundwater monitoring and analysis of soil cores suggest that intrinsic bioremediation is occurring at these sites by multiple pathways including aerobic oxidation, Fe{sup 3+} reduction, and sulfate reduction. In laboratory experiments the addition of gas condensate hydrocarbons to saturated soil from the gas production site stimulated sulfate reduction under anaerobic and oxygen-limiting conditions, and nitrate and Fe{sup 3+} reduction under oxygen-limiting conditions, compared to biotic controls that lacked hydrocarbon and sterile controls. The sulfate reduction corresponded to a reduction in the amount of toluene relative to other hydrocarbons. These results confirmed that subsurface soils at the gas production site have the potential for intrinsic bioremediation of hydrocarbons.

  19. 含铋复合氧化物催化剂的研究进展%Research progress in bismuth-containing complex oxide catalysts

    Institute of Scientific and Technical Information of China (English)

    王鹏; 陈晓晖; 魏可镁

    2011-01-01

    Bismuth-containing complex oxides is an research hotspot of selective oxidation and photocatalysis at present. Bismuth oxide can combine with titanium oxide, vanadium oxide, iron oxide, copper oxide,molybdenum oxide ,silicon oxide and tungsten oxide to form bismuth-containing complex oxide catalysts.The research advance on bismuth-containing complex oxide catalysts was reviewed. The research aspects of bismuth-containing complex oxide catalysts in the future were outlined.%含铋复合金属氧化物是当前选择性氧化和光催化方面的研究热点.主要介绍了近年来氧化铋与氧化钛、氧化钒、氧化铁、氧化铜、氧化钼、氧化硅和氧化钨等的复合氧化物催化剂的研究进展,并指出了含铋复合氧化物今后的研究方向.

  20. Roles of apolipoprotein E (ApoE and inducible nitric oxide synthase (iNOS in inflammation and apoptosis in preeclampsia pathogenesis and progression.

    Directory of Open Access Journals (Sweden)

    Luyi Mao

    Full Text Available OBJECTIVES: To investigate potential roles of inducible nitric oxide synthase (iNOS and apolipoprotein (apoE in inflammation and apoptosis promoting pathological changes in preeclampsia in pregnant mice with apoE and/or iNOS knock out. METHODS: B6.129 mice were crossed to produce WT, apoE(-/-, apoE(+/-, iNOS(-/-, iNOS(+/- and apoE(-/-iNOS(-/- groups. Variants were confirmed by PCR. Serum lipid parameters (triglycerides, TG; total cholesterol, TC; high density lipoprotein, HDL; and low density lipoprotein, LDL, NO levels and placental electronic microscopic ultrastructures were evaluated, and blood pressure (BP, 24-hour urine protein and pregnancy outcomes were recorded for pregnant F1 generation mice. Placental expressions of inflammatory (tumor necrosis factor-α, TNF-α; interleukin-6, IL-6; nuclear factor-κB, NF-κb and apoptotic markers (Bcl-2 associated X protein, Bax, B-cell lymphoma/leukemia-2, Bcl-2, and Caspase-3 were evaluated via Western blot. RESULTS: Serum lipids, BP and 24-hour urine protein levels were shown to be significantly higher and parturition and placenta weights were lower in apoE(-/- and apoE(-/-iNOS(-/- groups (p0.05 showed no differences. In addition, placenta vascular endothelial and trophoblast cell morphological changes were demonstrated in both the apoE(-/-iNOS(-/- and apoE(-/- groups. CONCLUSION: Elevated lipid metabolism and inflammatory/apoptosis parameters suggest a potentially significant role of apoE in preeclampsia pathology, as well as a relationship between iNOS and preeclampsia progression.

  1. Multidose Streptozotocin Induction of Diabetes in BALB/c Mice Induces a Dominant Oxidative Macrophage and a Conversion of TH1 to TH2 Phenotypes During Disease Progression

    Directory of Open Access Journals (Sweden)

    Naxin Sun

    2005-01-01

    Full Text Available Macrophages (Mp are implicated in both early and late phases in type 1 diabetes development. Recent study has suggested that a balance between reductive Mp (RMp and oxidative Mp (OMp is possible to regulate TH1/TH2 balance. The aim of this study is to investigate the redox status of peritoneal Mp and its cytokine profile during the development of autoimmune diabetes induced by multiple low-dose streptozotocin in BALB/c mice. Meanwhile, the polarization of TH1/TH2 of splenocytes or thymocytes was also examined. We found that peritoneal Mp appeared as an “incomplete” OMp phenotype with decreased icGSH along with disease progression. The OMp showed reduced TNF-α, IL-12, and NO production as well as defective phagocytosis activity compared to nondiabetic controls; however, there was no significant difference with IL-6 production. On the other hand, the levels of IFN-γ or IL-4 of splenocytes in diabetic mice were significantly higher compared to the control mice. The ratio of IFN-γ to IL-4 was also higher at the early stage of diabetes and then declined several weeks later after the occurrence of diabetes, suggesting a pathogenetic TH1 phenotype from the beginning gradually to a tendency of TH2 during the development of diabetes. Our results implied that likely OMp may be relevant in the development of type 1 diabetes; however, it is not likely the only factor regulating the TH1H/TH2 balance in MLD-STZ-induced diabetic mice.

  2. IFN-γ and TNF-α are involved during Alzheimer disease progression and correlate with nitric oxide production: a study in Algerian patients.

    Science.gov (United States)

    Belkhelfa, Mourad; Rafa, Hayet; Medjeber, Oussama; Arroul-Lammali, Amina; Behairi, Nassima; Abada-Bendib, Myriam; Makrelouf, Mohamed; Belarbi, Soreya; Masmoudi, Ahmed Nacer; Tazir, Meriem; Touil-Boukoffa, Chafia

    2014-11-01

    Alzheimer's disease (AD) is a neurodegenerative disease leading to a progressive and irreversible loss of mental functions. It is characterized by 3 stages according to the evolution and the severity of the symptoms. This disease is associated with an immune disorder, which appears with significant rise in the inflammatory cytokines and increased production of free radicals such as nitric oxide (NO). Our study aims to investigate interferon (IFN)-γ and tumor necrosis factor-α (TNF-α) involvement in NO production, in vivo and ex vivo, in peripheral blood mononuclear cells from Algerian patients (n=25), according to the different stages of the disease (mild Alzheimer's, moderate Alzheimer's, and severe Alzheimer's) in comparison to mild cognitive impairment (MCI) patients. Interestingly, we observed that in vivo IFN-γ and TNF-α levels assessed in patients with AD in mild and severe stages, respectively, are higher than those observed in patients with moderate stage and MCI. Our in vivo and ex vivo results show that NO production is related to the increased levels of IFN-γ and TNF-α, in mild and severe stages of AD. Remarkably, significant IFN-γ level is only detected in mild stage of AD. Our study suggests that NO production is IFN-γ dependent both in MCI and mild Alzheimer's patients. Further, high levels of NO are associated with an elevation of TNF-α levels in severe stage of AD. Collectively, our data indicate that the proinflammatory cytokine production seems, in part, to be involved in neurological deleterious effects observed during the development of AD through NO pathway.

  3. Research progress of oxidative stress of coronary heart disease patients with different glucose metabolism status%不同糖代谢状态冠心病患者氧化应激的研究进展

    Institute of Scientific and Technical Information of China (English)

    姚志灵; 陈亮; 王欣丽

    2015-01-01

    氧化应激水平可以通过抗氧化酶系水平、非酶系抗氧化水平及氧化产物水平检测。在糖尿病前期患者体内存在高氧化应激状态,随着糖代谢紊乱加重,体内自由基生成增加,抗氧化能力下降,氧化应激水平升高,氧化与抗氧化失衡。在2型糖尿病患者中,随着糖尿病的病程延长,氧化应激水平随之升高,且胰岛β细胞功能下降,胰岛素抵抗增加。动脉粥样硬化的发生发展与氧化应激有密切关系,冠心病患者体内已存在氧化应激,且机体抗氧化能力减弱。在冠心病合并糖尿病患者中,随着病情进展,氧化损伤程度呈逐渐加重趋势。本文就不同糖代谢状态冠心病患者氧化应激的相关性研究进展进行综述。%The level of oxidative stress can be tested by antioxidant enzyme system level, antioxidant non-enzyme dsystem level and oxidation products. High oxidative stress state exists in people who have pre-diabetes, and with the sugar metabolic disorder exacerbating, free radicals generation increased, the ability of anti-oxidation dropped, the lev-el of oxidative stress raised, oxidation and antioxidant imbalanced. In patients with type 2 diabetes, with the course of diabetes being longer, the level of oxidative stress will increase, and else the function of the islet beta cell dropped, in-sulin resistance increased. The development of atherosclerosis has deeply related with oxidative stress. There is oxida-tive stress in coronary heart disease patients, and the body's antioxidant capacity reduced. In patients with coronary heart disease and diabetes mellitus, as the disease progresses, the degree of oxidative damage also shows a trend of in-crease gradually. In this paper, the research progress of the correlation of oxidative stress of different glucose metabolism status in patients with coronary heart disease will be reviewed.

  4. Oral Administration Of Aloe Vera (l.) Burm. F. (xanthorrhoeaceae) And Honey Improves The Host Body Composition And Modulates Proteolysis Through Reduction Of Tumor Progression And Oxidative Stress In Rats

    OpenAIRE

    Tomasin, Rebeka; de Andrade, Rafael Siqueira; Gomes-Marcondes, Maria Cristina Cintra

    2016-01-01

    Oxidative stress has a dual role in cancer; it is linked with tumorigenic events and host wasting, as well as senescence and apoptosis. Researchers have demonstrated the importance of coadjuvant therapies in cancer treatment, and Aloe vera and honey have immunomodulatory, anticancer, and antioxidant properties. The preventive and therapeutic effects of Aloe vera (L.) Burm. f. (Xanthorrhoeaceae) and honey in tumor progression and host wasting were analyzed in Walker 256 carcinoma-bearing rats....

  5. Remediation of hydrocarbons in crude oil-contaminated soils using Fenton's reagent.

    Science.gov (United States)

    Ojinnaka, Chukwunonye; Osuji, Leo; Achugasim, Ozioma

    2012-11-01

    Sandy soil samples spiked with Bonny light crude oil were subsequently treated with Fenton's reagent at acidic, neutral, and basic pH ranges. Oil extracts from these samples including an untreated one were analyzed 1 week later with a gas chromatograph to provide evidence of hydrocarbon depletion by the oxidant. The reduction of three broad hydrocarbon groups-total petroleum hydrocarbon (TPH); benzene, toluene, ethylbenzene, and xylene (BTEX); and polycyclic aromatic hydrocarbon (PAH) were investigated at various pHs. Hydrocarbon removal was efficient, with treatment at the acidic pH giving the highest removal of about 96% for PAH, 99% for BTEX, and some TPH components experiencing complete disappearance. The four-ringed PAHs were depleted more than their three-ringed counterparts at the studied pH ranges.

  6. PHOTOOXIDATION OF HYDROCARBONS TO PARTIAL OXYGENATES IN AN AQUEOUS ENVIRONMENT [EXHIBIT, POSTER

    Science.gov (United States)

    The USEPA is researching the use of alternative oxidation technologies (AOT's) as a catalytic process for the selective oxidation of hydrocarbon substrates. One AOT currently under investigation is the use of photocatalysis employed with a laminar thin-film falling reactor. Thi...

  7. 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...

  8. Growth of hydrocarbon utilizing microorganisms

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Mavinkurve, S.

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

  9. 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.

  10. 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...

  11. 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.

  12. 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

  13. 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)

  14. Catalysts for conversion of methane to higher hydrocarbons

    Science.gov (United States)

    Siriwardane, Ranjani V.

    1993-01-01

    Catalysts for converting methane to higher hydrocarbons such as ethane and ethylene in the presence of oxygen at temperatures in the range of about 700.degree. to 900.degree. C. are described. These catalysts comprise calcium oxide or gadolinium oxide respectively promoted with about 0.025-0.4 mole and about 0.1-0.7 mole sodium pyrophosphate. A preferred reaction temperature in a range of about 800.degree. to 850.degree. C. with a preferred oxygen-to-methane ratio of about 2:1 provides an essentially constant C.sub.2 hydrocarbon yield in the range of about 12 to 19 percent over a period of time greater than about 20 hours.

  15. Recent analytical methods for atmospheric polycyclic aromatic hydrocarbons and their derivatives.

    Science.gov (United States)

    Hayakawa, Kazuichi; Tang, Ning; Toriba, Akira

    2017-01-01

    Polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) are ubiquitous environmental pollutants. Moreover, some oxidative metabolites of these pollutants, such as hydroxylated and epoxide PAHs, cause endocrine disruption or produce reactive oxygen species. These compounds have become a large concern from the viewpoint of particulate matter (PM2.5 ) pollution. This report deals with recent studies concerning analytical methods for PAHs, NPAHs and related compounds in atmospheric and biological samples.

  16. Solid Oxide Fuel Cell

    DEFF Research Database (Denmark)

    2010-01-01

    The solid oxide fuel cell comprising a metallic support material, an active anode layer consisting of a good hydrocarbon cracking catalyst, an electrolyte layer, an active cathode layer, and a transition layer consisting of preferably a mixture of LSM and a ferrite to the cathode current collector...

  17. Solid Oxide Fuel Cell

    DEFF Research Database (Denmark)

    2010-01-01

    The solid oxide fuel cell comprising a metallic support material, an active anode layer consisting of a good hydrocarbon cracking catalyst, an electrolyte layer, an active cathode layer, and a transition layer consisting of preferably a mixture of LSM and a ferrite to the cathode current collector...

  18. Direct conversion of light hydrocarbon gases to liquid fuel. Final report No. 33

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, R.D.; Foral, M.J.

    1992-05-16

    Amoco oil Company, has investigated the direct, non-catalytic conversion of light hydrocarbon gases to liquid fuels (particularly methanol) via partial oxidation. The primary hydrocarbon feed used in these studies was natural gas. This report describes work completed in the course of our two-year project. In general we determined that the methanol yields delivered by this system were not high enough to make it economically attractive. Process variables studied included hydrocarbon feed composition, oxygen concentration, temperature and pressure effects, residence time, reactor design, and reactor recycle.

  19. The presence of pollutant hydrocarbons in estuarine epipelic diatom populations. II. Diatom slimes

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, S.; Eglinton, G.

    1979-01-01

    Diatom slime in sediment from the Severn intertidal estuary was analyzed for polycyclic aromatic hydrocarbons (PAH's) and aliphatic hydrocarbons, using computerized capillary gas chromatography/mass spectrometry. The distributions of these substances in diatoms were compared with those in the underlying sediment and in a sediment-free diatom population. Aliphatic hydrocarbon distribution in slime was about the same as that of separated diatoms and sediment, while PAH distribution in slime was about that of the sediment alone. These results suggest a loss of PAH's from the coalesced sediment in the slime, probably either by a photo-oxidative or catabolic process. 34 references, 2 tables.

  20. Direct conversion of light hydrocarbon gases to liquid fuel. Final report No. 33

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, R.D.; Foral, M.J.

    1992-05-16

    Amoco oil Company, has investigated the direct, non-catalytic conversion of light hydrocarbon gases to liquid fuels (particularly methanol) via partial oxidation. The primary hydrocarbon feed used in these studies was natural gas. This report describes work completed in the course of our two-year project. In general we determined that the methanol yields delivered by this system were not high enough to make it economically attractive. Process variables studied included hydrocarbon feed composition, oxygen concentration, temperature and pressure effects, residence time, reactor design, and reactor recycle.

  1. Plasma Assisted Combustion Mechanism for Small Hydrocarbons

    Science.gov (United States)

    2015-01-01

    O2 C2H6 C2H4 CH3OH iso‐propane CO2 C3H8 C3H6 C2H5OH neo‐pentane H2O C4H10 CH3OCH3  DME O3 C5H12 Ar H2 N2O PAC  Kinetic  Mechanism  O(-)+N(+)=N+O... Kinetic  Model:  Previous Versions D.V.Zatsepin, S.M.Starikovskaia, A.Yu.Starikovskii Hydrogen oxidation in a  stoichiometric hydrogen‐air mixtures in the... Kinetics  of ignition of saturated hydrocarbons by nonequilibrium plasma: C2H6‐ to C5H12‐containing mixtures. Combustion and Flame 156  (2009) 221–233

  2. Sediment biogeochemistry and microbial activity at natural hydrocarbon seeps and at sites impacted by anthropogenic hydrocarbon discharges

    Science.gov (United States)

    Joye, S. B.; Sibert, R.; Battles, J.; Fields, L.; Kleindienst, S.; Crespo-Medina, M.; Hunter, K.; Meile, C. D.; Montoya, J. P.

    2013-12-01

    Natural hydrocarbon seeps occur along the seafloor where geologic faults facilitate transfer of deeply sourced fluids enriched in gas, oil, and dissolved organic matter through shallow sediments and into the water column. At natural seeps, microbial populations specialize in hydrocarbon degradation and rates of microbial activity, including sulfate reduction and anaerobic oxidation of methane, can be extremely high. As a result, the biogeochemical signature of sediments near areas of active natural seepage is distinct: high concentrations of metabolic end products, such as dissolved inorganic carbon and hydrogen sulfide, abound, and often, high dissolved inorganic carbon concentrations result in the precipitation of authigenic carbonate minerals. We examined microbial processes and biogeochemical signatures at two natural seeps, Green Canyon 600 and Mississippi Canyon 118. Higher and more frequent seepage loci at the Green Canyon 600 site led to more widespread hotspots of elevated microbial activity and distinct geochemistry. However, rates of microbial activity were comparable at the two sites in areas of active hydrocarbon seepage. The microbial communities at the two sites were surprisingly different. The second group of sites was impacted by anthropogenic hydrocarbon discharges instead of natural seepage. One site, Oceanus 26, lies near the Deepwater Horizon/Macondo wellhead and was impacted by weathered oil sedimentation during the Macondo discharge. The second set of impacted sites, noted as Taylor Energy, lie near a sunken platform and compromised riser, which have together resulted in persistent hydrocarbon discharge to the adjacent oceanic system for more than 6 years. Rates of microbial activity in the upper sediments at Oceanus 26 were depressed relative to activity in the deeper layers, suggesting inhibition by the presence of weathered oil or an microbial community unable to weather the carbon available in the layer. At the Taylor energy site

  3. Apparatus for hydrogen and carbon production via carbon aerosol-catalyzed dissociation of hydrocarbons

    Science.gov (United States)

    Muradov, Nazim Z. (Inventor); Smith, Franklyn (Inventor); Tabatabaie-Raissi, Ali (Inventor)

    2012-01-01

    A novel process and apparatus is disclosed for sustainable, continuous production of hydrogen and carbon by catalytic dissociation or decomposition of hydrocarbons at elevated temperatures using in-situ generated carbon particles. Carbon particles are produced by decomposition of carbonaceous materials in response to an energy input. The energy input can be provided by at least one of a non-oxidative and oxidative means. The non-oxidative means of the energy input includes a high temperature source, or different types of plasma, such as, thermal, non-thermal, microwave, corona discharge, glow discharge, dielectric barrier discharge, or radiation sources, such as, electron beam, gamma, ultraviolet (UV). The oxidative means of the energy input includes oxygen, air, ozone, nitrous oxide (NO.sub.2) and other oxidizing agents. The method, apparatus and process of the present invention is applicable to any gaseous or liquid hydrocarbon fuel and it produces no or significantly less CO.sub.2 emissions compared to conventional processes.

  4. 氧化物薄膜晶体管研究进展∗%Research progress on oxide-based thin film transisitors

    Institute of Scientific and Technical Information of China (English)

    兰林锋; 张鹏; 彭俊彪

    2016-01-01

    Oxide semiconductor is regarded as one of most suitable active materials of thin-film transistors (TFTs) for driving organic light-emitting diodes because of its advantages of high mobility, low-temperature processing, good electrical uniformity, visible-light transparency, and low cost. Currently oxide TFTs have been successfully applied to the back-planes of the flat-panel displays. This review gives a comprehensive understanding of the development process of oxide TFTs. In the present article, we review the major trend in the field of oxide TFTs. First, the questions of how to achieve high-mobility and high-stability oxide semiconductors are introduced, and the carrier transport mechanism is also addressed. Next, the device structures and the fabrication processes of the oxide TFTs are introduced. The electri-cal instability of the oxide TFTs is also discussed, which is critical for their applications in backplanes of the flat-panel displays. Especially, the mechanism of the threshold voltage instability of the oxide TFTs under negative bias illuminant stress is discussed in detail. Finally, the applications of oxide TFTs in flat-panel displays, such as active matrix organic light-emitting diodes and flexible displays, are addressed.

  5. Magnetic Susceptibility Measurements as a Proxy for Hydrocarbon Biodegradation

    Science.gov (United States)

    Mewafy, F.; Atekwana, E. A.; Slater, L. D.; Werkema, D.; Revil, A.; Ntarlagiannis, D.; Skold, M.

    2011-12-01

    Magnetic susceptibility (MS) measurements have been commonly used in paleoclimate studies, as a proxy for environmental pollution such as heavy metal contamination, and for delineating zones of oil seeps related to hydrocarbon exploration. Few studies have assessed the use of MS measurements for mapping zones of oil pollution. In this study, we investigated the variation in magnetic susceptibility across a hydrocarbon contaminated site undergoing biodegradation. Our objective was to investigate if MS measurements could be used as a proxy indicator of intrinsic bioremediation linked to the activity of iron reducing bacteria. An improved understanding of the mechanisms generating geophysical signatures associated with microbial enzymatic activity could permit the development of geophysical imaging technologies for long-term, minimally invasive and sustainable monitoring of natural biodegradation at oil spill sites. We used a Bartington MS probe to measure MS data along fifteen boreholes within contaminated (both free phase and dissolved phase hydrocarbon plumes) and clean areas. Our results show the following: (1) an enhanced zone of MS straddling the water table at the contaminated locations, not observed at the clean locations; (2) MS values within the free product plume are higher compared to values within the dissolved product plume; (3) the MS values within the vadoze zone above the free product plume are higher compared to values within the dissolved product plume; 4) the zone of high MS is thicker within the free product plume compared to the dissolved product plume. We suggest that the zone of enhanced MS results from the precipitation of magnetite related to the oxidation of the hydrocarbons coupled to iron reduction. Our data documents a strong correlation between MS and hydrocarbon concentration. We conclude that recognition of these zones of enhanced magnetite formation allows for the application of MS measurements as a: (1) low cost, rapid monitoring

  6. Redox Stable Anodes for Solid Oxide Fuel Cells

    Directory of Open Access Journals (Sweden)

    Guoliang eXiao

    2014-06-01

    Full Text Available Solid oxide fuel cells (SOFCs can convert chemical energy from the fuel directly to electrical energy with high efficiency and fuel flexibility. Ni-based cermets have been the most widely adopted anode for SOFCs. However, the conventional Ni-based anode has low tolerance to sulfur-contamination, is vulnerable to deactivation by carbon build-up (coking from direct oxidation of hydrocarbon fuels, and suffers volume instability upon redox cycling. Among these limitations, the redox instability of the anode is particularly important and has been intensively studied since the SOFC anode may experience redox cycling during fuel cell operations even with the ideal pure hydrogen as the fuel. This review aims to highlight recent progresses on improving redox stability of the conventional Ni-based anode through microstructure optimization and exploration of alternative ceramic-based anode materials.

  7. Preparation and Aromatic Hydrocarbon Removal Performance of Potassium Ferrate

    Directory of Open Access Journals (Sweden)

    Wei Guan

    2014-01-01

    Full Text Available This experiment adopts the hypochlorite oxidation method to constantly synthesize potassium ferrate. Under the condition of micropolluted source water pH and on the basis of naphthalene, phenanthrene, and pyrene as research objects, the effects of different systems to remove aromatic hydrocarbons were studied. Various oxidation systems to remove phenanthrene intermediate are analyzed and the detailed mechanisms for removal of phenanthrene are discussed. The study found that the main intermediate of potassium ferrate system to transform phenanthrene is 9,10-phenanthraquinone and its area percentage reached 82.66%; that is, 9,10-phenanthraquinone is the key entity to remove phenanthrene.

  8. Solid hydrocarbon assisted reduction: a new process of generating micron scale metal particles

    OpenAIRE

    Ryan M McCabe

    2015-01-01

    Approved for public release; distribution is unlimited The goal of this research is to test a central hypothesis: that gas species generated by the thermal and/or catalytically assisted decomposition of hydrocarbons in an inert atmosphere can reduce metal oxides to a metallic state. It is postulated that the decomposition releases gas phase radicals that can bind with oxygen in the metal oxides, forming volatile, stable oxides such as CO2 and water. This research consisted of thermally dec...

  9. Research Progress on Oxidative Stress of Islet Beta Cells in Type 2 Diabetes Mellitus%2型糖尿病胰岛β细胞氧化应激的研究进展

    Institute of Scientific and Technical Information of China (English)

    裴晓艳; 张晓梅

    2011-01-01

    Objective:To investigate the research advancement on oxidative stress of islet beta cells in type 2 diabetes Mellitus (T2 DM).Methods:To explore the research progress on oxidative stress of islet beta cells in T2 DM from the concept of oxidative stress, the oxidative stress factors of islet beta cells and the mechanism of oxidative stress damage in islet beta cells.Results: Because of lower level of antioxidant system in beta cells of islet in T2 DM, oxidative stress will easily occur during metabolic process of hyperglycaemia and hyperlipemia.Oxidative stress impairs β - cell function through many approaches, decreases insulin synthesis and secretion, aggravates T2 DM.Conclusions: Oxidative stress will easily occur in beta cells and it is a complex progress as a result of many factors and pathways.Antioxidant application can protect β - cell function, prevent and treat the incidence and growth of T2 DM.%目的:探讨2型糖尿病(T2DM)胰岛β细胞氧化应激的研究进展.方法:从氧化应激的概念、胰岛β细胞发生氧化应激的因素、氧化应激损伤胰岛β细胞的机制三方面来探讨T2DM胰岛β细胞氧化应激的研究进展.结果:T2DM胰岛β细胞内含有较低水平的抗氧化系统, 在高糖、高脂等作用下,容易发生氧化应激反应, 氧化应激通过多种途径损伤胰岛β细胞, 使胰岛素合成分泌减少,加重T2DM.结论:T2DM胰岛β细胞容易发生氧化应激是多因素多途径共同作用的复杂过程,积极应用抗氧化剂治疗,能保护胰岛β细胞功能,预防和治疗T2DM的发生与发展.

  10. 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.

  11. Research progress on application of reduced graphene oxide/iron oxide nanocomposites%还原氧化石墨烯/四氧化三铁纳米复合物的应用研究进展

    Institute of Scientific and Technical Information of China (English)

    黄晨晨; 严姗#; 祁婷婷; 李秀娟; 潘思轶

    2015-01-01

    ABSTRACT:Reduced graphene oxide/iron oxide (RGO/Fe3O4) nanocomposites, which integrate the advantages of RGOand Fe3O4 nanoparticles, are novel magnetic nanomaterials. In recent years, RGO/Fe3O4 nanocomposites have exhibited infinite charm in theoretical research and practical application sowing to their excellent mechanical, electrical, optical and thermal properties such as large surface area, high stability and superparamagnetism. This review reported the research progress of RGO/Fe3O4nanocomposites in magnetic solid phase extraction, lithium ion battery, sensor materials, electromagnetic wave absorption, catalysts, enzyme immobilization, drug delivery and magnetic switches in recent years. The application of RGO/Fe3O4in magnetic solid phase extraction was reviewed emphatically and the analysis objects including dyes, metal ions, pesticides and veterinary drugs, plasticizers, antibiotics and biological macromolecules, showing its great potential in the field of separation and enrichment. Finally, the existing problems of RGO/Fe3O4in research were put forward and the research and development orientation was briefly described.%还原氧化石墨烯/四氧化三铁(RGO/Fe3O4)纳米复合物是一种新型的磁性纳米材料,集Fe3O4和RGO的优点于一体,具备高比表面积、高稳定性、超顺磁性等优越的机械、电、热、光学特性,充分展现其在理论研究以及实际应用方面的价值和潜力。本文对近几年 RGO/Fe3O4磁性纳米复合物材料在磁性固相萃取、锂电子电池、传感器材料、电磁波吸收、催化剂、酶的固定化、药物传输以及磁控开关方面的应用研究进展进行了综述,重点综述了RGO/Fe3O4磁性纳米复合材料在磁性固相萃取方面的应用研究,分析对象包括染料、金属离子、农兽药、增塑剂、抗生素以及生物大分子,展现出其在分离富集领域的巨大应用潜力。最后,提出RGO/Fe3O4纳米复合材料在研究中

  12. [Characterization of a thermophilic Geobacillus strain DM-2 degrading hydrocarbons].

    Science.gov (United States)

    Liu, Qing-kun; Wang, Jun; Li, Guo-qiang; Ma, Ting; Liang, Feng-lai; Liu, Ru-lin

    2008-12-01

    A thermophilic Geobacillus strain DM-2 from a deep-subsurface oil reservoir was investigated on its capability of degrading crude oil under various conditions as well as its characters on degrading hydrocarbons in optimal conditions. The results showed that Geobacillus strain DM-2 was able to degrade crude oil under anoxic wide-range conditions with pH ranging from 4.0 to 10.0, high temperature in the range of 45-70 degrees C and saline concentration ranging from 0.2% to 3.0%. Furthermore, the optimal temperature and pH value for utilizing hydrocarbons by the strain were 60 degrees C and 7.0, respectively. Under such optimal conditions, the strain utilized liquid paraffine emulsified by itself as its carbon source for growth; further analysis by gas chromatography (GC) and infrared absorption spectroscopy demonstrated that it was able to degrade n-alkanes (C14-C30), branched-chain alkanes and aromatic hydrocarbons in crude oil and could also utilize long-chain n-alkanes from C16 to C36, among of which the degradation efficiency of C28 was the highest, up to 88.95%. One metabolite of the strain oxidizing alkanes is fatty acid.While utilizing C16 as carbon source for 5 d, only one fatty acid-acetic acid was detected by HPLC and MS as the product, with the amount of 0.312 g/L, which indicated that it degraded n-alkanes with pathway of inferior terminal oxidation,and then followed by a beta-oxidation pathway. Due to its characters of efficient emulsification, high-performance degradation of hydrocarbons and fatty-acid production under high temperature and anoxic condition, the strain DM-2 may be potentially applied to oil-waste treatment and microbial enhanced heavy oil recovery in extreme conditions.

  13. The reformation of liquid hydrocarbons in an aqueous discharge reactor

    KAUST Repository

    Zhang, Xuming

    2015-04-21

    We present an aqueous discharge reactor for the reformation of liquid hydrocarbons. To increase a dielectric constant of a liquid medium, we added distilled water to iso-octane and n-dodecane. As expected, we found decreased discharge onset voltage and increased discharge power with increased water content. Results using optical emission spectroscopy identified OH radicals and O atoms as the predominant oxidative reactive species with the addition of water. Enriched CH radicals were also visualized, evidencing the existence of cascade carbon-carbon cleavage and dehydrogenation processes in the aqueous discharge. The gaseous product consisted primarily of hydrogen, carbon monoxide, and unsaturated hydrocarbons. The composition of the product was readily adjustable by varying the volume of water added, which demonstrated a significant difference in composition with respect to the tested liquid hydrocarbon. In this study, we found no presence of CO2 emissions or the contamination of the reactor by solid carbon deposition. These findings offer a new approach to the reforming processes of liquid hydrocarbons and provide a novel concept for the design of a practical and compact plasma reformer. © 2015 IOP Publishing Ltd.

  14. Chemical Kinetics of Hydrocarbon Ignition in Practical Combustion Systems

    Energy Technology Data Exchange (ETDEWEB)

    Westbrook, C.K.

    2000-07-07

    Chemical kinetic factors of hydrocarbon oxidation are examined in a variety of ignition problems. Ignition is related to the presence of a dominant chain branching reaction mechanism that can drive a chemical system to completion in a very short period of time. Ignition in laboratory environments is studied for problems including shock tubes and rapid compression machines. Modeling of the laboratory systems are used to develop kinetic models that can be used to analyze ignition in practical systems. Two major chain branching regimes are identified, one consisting of high temperature ignition with a chain branching reaction mechanism based on the reaction between atomic hydrogen with molecular oxygen, and the second based on an intermediate temperature thermal decomposition of hydrogen peroxide. Kinetic models are then used to describe ignition in practical combustion environments, including detonations and pulse combustors for high temperature ignition, and engine knock and diesel ignition for intermediate temperature ignition. The final example of ignition in a practical environment is homogeneous charge, compression ignition (HCCI) which is shown to be a problem dominated by the kinetics intermediate temperature hydrocarbon ignition. Model results show why high hydrocarbon and CO emissions are inevitable in HCCI combustion. The conclusion of this study is that the kinetics of hydrocarbon ignition are actually quite simple, since only one or two elementary reactions are dominant. However, there are many combustion factors that can influence these two major reactions, and these are the features that vary from one practical system to another.

  15. 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

  16. 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 ...

  17. 含铜半导体氧化物的光催化应用进展%Photocatalytic research progress of Cu-based semiconductor oxides

    Institute of Scientific and Technical Information of China (English)

    康园丽; 王桂赟; 刘宗园; 王延吉

    2012-01-01

    It is a hot point in material research area,that semiconductive materials are used to split water for hydrogen evolution and degrade pollutants,in recent decades.From the point of the development range of photocatalyst material,the basic properties,preparation method and the photocatalytic application of the containing copper semiconductor oxides are summarized.The oxides discussed in this paper include two kinds of oxides,the first type containing Cu(Ⅰ) named cuprous oxide and delafossite oxides,and second type containing Cu(Ⅱ) named copper oxide and spinelle composite oxides.Composing Cu-based semiconductor oxides with n-type semiconductor material to obtain p-n heterogeneity composite oxides should be a promising research direction.%应用半导体材料光催化降解污染物和光催化分解水制氢是近几十年来的材料研究热点之一。从拓展光催化材料种类的角度出发,本文对含铜半导体氧化物的基本性质、制备方法及其在光催化方面的应用情况进行了综述。所涉及的氧化物包括含一价铜的氧化亚铜和铜铁矿类复合氧化物,以及含二价铜的氧化铜和尖晶石类复合氧化物。指出将含铜p型半导体氧化物与n型半导体材料复合,制备p-n异质型复合氧化物是有前途的研发方向。

  18. Insights into the superhydrophobicity of metallic surfaces prepared by electrodeposition involving spontaneous adsorption of airborne hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Peng; Cao, Ling; Zhao, Wei; Xia, Yue; Huang, Wei; Li, Zelin, E-mail: lizelin@hunnu.edu.cn

    2015-01-01

    Graphical abstract: - Highlights: • Several superhydrophobic metallic surfaces were fabricated by fast electrodeposition. • Both micro/nanostructures and adsorption of airborne hydrocarbons make contributions. • XPS analyses confirm presence of airborne hydrocarbons on these metallic surfaces. • The adsorption of airborne hydrocarbons on the clean metal Au surface was very quick. • UV-O{sub 3} treatment oxidized the hydrocarbons to hydrophilic oxygen-containing organics. - Abstract: Electrochemical fabrication of micro/nanostructured metallic surfaces with superhydrophobicity has recently aroused great attention. However, the origin still remains unclear why smooth hydrophilic metal surfaces become superhydrophobic by making micro/nanostructures without additional surface modifications. In this work, several superhydrophobic micro/nanostructured metal surfaces were prepared by a facile one-step electrodeposition process, including non-noble and noble metals such as copper, nickel, cadmium, zinc, gold, and palladium with (e.g. Cu) or without (e.g. Au) surface oxide films. We demonstrated by SEM and XPS that both hierarchical micro/nanostructures and spontaneous adsorption of airborne hydrocarbons endowed these surfaces with excellent superhydrophobicity. We revealed by XPS that the adsorption of airborne hydrocarbons at the Ar{sup +}-etched clean Au surface was rather quick, such that organic contamination can hardly be prevented in practical operation of surface wetting investigation. We also confirmed by XPS that ultraviolet-O{sub 3} treatment of the superhydrophobic metal surfaces did not remove the adsorbed hydrocarbons completely, but mainly oxidized them into hydrophilic oxygen-containing organic substances. We hope our findings here shed new light on deeper understanding of superhydrophobicity for micro/nanostructured metal surfaces with and without surface oxide films.

  19. Comprehensive geochemical identification of highly evolved marine hydrocarbon source rocks: Organic matter, paleoenvironment and development of effective hydrocarbon source rocks

    Institute of Scientific and Technical Information of China (English)

    TENGER; LIU Wenhui; XU Yongchang; CHEN Jianfa; HU Kai; GAO Changlin

    2006-01-01

    This study analyzed the developing environments of hydrocarbon source rocks in the Ordos Basin and evaluated carbonate rocks as hydrocarbon source rocks and their distributions on account of the fact that China's marine carbonate rocks as hydrocarbon source rocks are characterized by the intensive thermal evolution and relatively low abundance of organic matter, by taking the Lower Paleozoic of the Ordos Basin for example and in light of the calculated enrichment coefficients of trace elements, the profile analysis of trace element contents, ratios of relevant elements, and stable isotopic compositions and their three-dimensional diagrammatization in combination with the necessary organic parameters. As for the Ordos Basin, TOC=0.2% is an important boundary value. Studies have shown that in the strata TOC>0.2%, V/(V+Ni)>0.50, Zr/Rb<2, Rb/K(×104)>30, Z>122, Th/U>0.80, Zn and Mo are enriched with a positive δ13Ccarb excursion. All these indicated a stagnant and stratified sedimentary environment that has low energy, anoxia and high salinity in bottom water. In these strata the geological conditions are good for the preservation of organic matter, hence favoring the development of hydrocarbon source rocks. These strata have δ13Corg<-28‰ (Ⅰ-Ⅱtype) and high hydrocarbon-generated potential. The Klimory and Wulalik formations show certain regularities in those aspects, therefore, they can be regarded as the potential effective hydrocarbon source rocks. In the strata TOC≤0.2%, Zr/Rb>1, V/(V+Ni)<0.50, Rb/K<30, Th/U<0.80, Cu, Zn, etc are depleted, and δ13Corg values range from -24‰ to -28‰. All these facts showed that most of the carbonate rocks or mudstones were formed in high-energy oxidizing environments, thus unfavorable to the development of hydrocarbon source rocks. It is feasible to make use of the geochemical method to comprehensively assess the highly evolved marine carbonates rocks as potential hydrocarbon source rocks and

  20. Paraffin Oxidation Studies

    Directory of Open Access Journals (Sweden)

    Mrs. S. J. Purohit

    2013-02-01

    Full Text Available The oxidation of paraffin has been studied with keen interest by several workers from all over the world; as oxidation leads to the introduction of various functional groups in hydrocarbon chains. Processes involving the Oxidation of Paraffin’s in the liquid phase, using air or oxygen are of great importance to industrialized economies because of their role in converting petroleum hydrocarbon feed stocks such as alkanes, olefins and aromatics into industrial organic chemicals important in the polymer, petrochemicals ,cosmetics and detergent industries. The oxidation leads predominantly to the formation of secondary alcohols consisting of a mixture of all possible isomers with the same number of carbon atoms in the molecules as the initial hydrocarbons. The secondary alcohols which are oxidation products of paraffin exhibit excellent hydrolytic, oxidative and color stability, because of the nature of their branching. These alcohols have lower melting points than straight chain alcohols of corresponding length, while retaining their high temperature stability. The oxidation of paraffin wax to fatty acids is carried out in temperature range 110 0C- 140 0C. Paraffin oxidation which is carried out by ALFOL, Oxo-processes, are high temperature, high pressure processes which utilize expensive catalysts, making them energy intensive as well as expensive. The maximum conversion achieved yet by existing processes is 15�0for a batch time of 4 hours. A cheaper alternative in this article has been studied, in which paraffin Oxidation has been carried out in a foam reactor at moderate temperature and pressure with suitable catalyst , the output of the products is increased up to 62%.

  1. 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....

  2. 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.

  3. 线粒体一氧化氮合酶的研究进展%Progress in mitochondrial nitric oxide synthase

    Institute of Scientific and Technical Information of China (English)

    孙晓四; 谭敦勇; 王华东; 颜亮

    2003-01-01

    Nitric oxide (NO) is an intra - and intercellular messenger with a broad spectrum of activities in the central nervous system, cardiovascular and immune systems. Mitochondrial nitric oxide synthase(mtNOS), which might be a new form of NOS in mitochondria, has been discovered to be active in the regulation of mitochondrial respiration, energy metabolism and manypathophysiological processes. In this review, the location, properties, physiological and pathophysiological significance of mtNOS were summarized.

  4. Porphyrins Fused with Unactivated Polycyclic Aromatic Hydrocarbons

    KAUST Repository

    Diev, Vyacheslav V.

    2012-01-06

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

  5. Oxidative/Nitrative Stress and Inflammation Drive Progression of Doxorubicin-Induced Renal Fibrosis in Rats as Revealed by Comparing a Normal and a Fibrosis-Resistant Rat Strain.

    Directory of Open Access Journals (Sweden)

    Csaba Imre Szalay

    Full Text Available Chronic renal fibrosis is the final common pathway of end stage renal disease caused by glomerular or tubular pathologies. Genetic background has a strong influence on the progression of chronic renal fibrosis. We recently found that Rowett black hooded rats were resistant to renal fibrosis. We aimed to investigate the role of sustained inflammation and oxidative/nitrative stress in renal fibrosis progression using this new model. Our previous data suggested the involvement of podocytes, thus we investigated renal fibrosis initiated by doxorubicin-induced (5 mg/kg podocyte damage. Doxorubicin induced progressive glomerular sclerosis followed by increasing proteinuria and reduced bodyweight gain in fibrosis-sensitive, Charles Dawley rats during an 8-week long observation period. In comparison, the fibrosis-resistant, Rowett black hooded rats had longer survival, milder proteinuria and reduced tubular damage as assessed by neutrophil gelatinase-associated lipocalin (NGAL excretion, reduced loss of the slit diaphragm protein, nephrin, less glomerulosclerosis, tubulointerstitial fibrosis and matrix deposition assessed by periodic acid-Schiff, Picro-Sirius-red staining and fibronectin immunostaining. Less fibrosis was associated with reduced profibrotic transforming growth factor-beta, (TGF-β1 connective tissue growth factor (CTGF, and collagen type I alpha 1 (COL-1a1 mRNA levels. Milder inflammation demonstrated by histology was confirmed by less monocyte chemotactic protein 1 (MCP-1 mRNA. As a consequence of less inflammation, less oxidative and nitrative stress was obvious by less neutrophil cytosolic factor 1 (p47phox and NADPH oxidase-2 (p91phox mRNA. Reduced oxidative enzyme expression was accompanied by less lipid peroxidation as demonstrated by 4-hydroxynonenal (HNE and less protein nitrosylation demonstrated by nitrotyrosine (NT immunohistochemistry and quantified by Western blot. Our results demonstrate that mediators of fibrosis

  6. Neutronics Benchmarks for the Utilization of Mixed-Oxide Fuel: Joint U.S./Russian Progress Report for Fiscal Year 1997 Volume 2-Calculations Performed in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Primm III, RT

    2002-05-29

    This volume of the progress report provides documentation of reactor physics and criticality safety studies conducted in the US during fiscal year 1997 and sponsored by the Fissile Materials Disposition Program of the US Department of Energy. Descriptions of computational and experimental benchmarks for the verification and validation of computer programs for neutron physics analyses are included. All benchmarks include either plutonium, uranium, or mixed uranium and plutonium fuels. Calculated physics parameters are reported for all of the computational benchmarks and for those experimental benchmarks that the US and Russia mutually agreed in November 1996 were applicable to mixed-oxide fuel cycles for light-water reactors.

  7. 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...

  8. 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.

  9. 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.

  10. Nonmethane hydrocarbon and oxy hydrocarbon measurements during the 2002 New England Air Quality Study

    Science.gov (United States)

    Goldan, Paul D.; Kuster, William C.; Williams, Eric; Murphy, Paul C.; Fehsenfeld, Fred C.; Meagher, James

    2004-11-01

    Nonmethane hydrocarbons (NMHCs) and oxy hydrocarbons (oxy HCs) were measured aboard the National Oceanic and Atmospheric Administration research vessel Ronald H. Brown during the New England Air Quality Study from 13 July to 10 August 2002 by an online dual gas chromatographic instrument with two separate analytical columns equipped, respectively, with flame ionization and mass spectrometer detectors. Measurements, taken each half hour, included C2 to C10 alkanes, C2 to C5 alkenes, alcohols and ketones, C6 to C9 aromatics, and biogenic volatile compounds including six monoterpenes, isoprene and its immediate oxidation products methacrolein and methylvinylketone. All compounds have been categorized by their contribution to the OH loss rate calculated for 298K and 1 atm. Large temporal variability was observed for all compounds. Airflow from the Providence, Rhode Island/Boston, Massachusetts, urban corridor northeast to the New Hampshire coast was usually heavily laden with NMHCs and oxy HCs of anthropogenic origin. Comparison of specific compound ratios with automotive tunnel studies suggested that these were predominantly mobile source emissions. When such flow occurred during daylight hours, these urban plumes were accompanied by increases in ozone in the 80 to 120 ppbv range. About equally as often, much less chemically mature NMHC plumes were encountered near the New Hampshire coast. Ozone was titrated out of these latter plumes, and the unusually high mixing ratios of C4 and C5 alkenes suggested that their source was partly gasoline vapor release rather than mobile source emissions. In the New England coastal region explored, in spite of the large anthropogenic NMHC input during periods of offshore flow, OH loss with hydrocarbons was frequently dominated by compounds of biogenic origin. During periods of cleaner marine air inflow the OH loss rate was dominated by reaction with methane and with oxy HCs, predominantly acetone, formaldehyde, and acetaldehyde.

  11. Ethylene Conversion to Higher Hydrocarbon over Copper Loaded BZSM-5 in the Presence of Oxygen

    Institute of Scientific and Technical Information of China (English)

    Ramli Mat; Nor Aishah Saidina Amin; Zainab Ramli; W.Azelee W.Abu Bakar

    2006-01-01

    The successful production of higher hydrocarbons from methane depends on the stability or the oxidation rate of the intermediate products. The performances of the BZSM-5 and the modified BZSM-5 catalysts were tested for ethylene conversion into higher hydrocarbons. The catalytic experiments were carried out in a fixed-bed micro reactor at atmospheric pressure. The catalysts were characterized using XRD, NH3-TPD, and IR for their structure and acidity. The result suggests that BZSM-5 is a weak acid. The introduction of copper into BZSM-5 improved the acidity of BZSM-5. The conversion of ethylene toward higher hydrocarbons is dependent on the acidity of the catalyst. Only weaker acid site is required to convert ethylene to higher hydrocarbons. The loading of Cu on BZSM-5 improved the selectivity for higher hydrocarbons especially at low percentage. The reactivity of ethylene is dependent on the amount of acidity as well as the presence of metal on the catalyst surface. Cu1%BZSM-5 is capable of converting ethylene to higher hydrocarbons. The balances between the metal and acid sites influence the performance of ethylene conversion and higher hydrocarbon selectivity. Higher loading of Cu leads to the formation of COx.

  12. Effects of unsaturated hydrocarbons on crop plants

    Energy Technology Data Exchange (ETDEWEB)

    Hall, W.C.; Heck, W.W.

    1960-01-01

    Damage to cotton and other crops in the vicinity of a Gulf Coast polyethylene plant has led to studies on the causative agent or agents responsible for crop losses. Responses exhibited by both native and cultivated plants of the area led to an initial diagnosis that the symptoms were caused by ethylene present in relatively high amounts in the atmosphere. Analysis of the stack gas showed 1.5% ethylene, 0.3% ethane, 8.7% carbon dioxide, 0.3% ethylene oxide and minute amounts of methane. Field analyses have shown concentrations of ethylene aging from 0.04 to 3 ppm depending upon atmospheric conditions (wind direction and velocity) as well as distance from the polyethylene plant. Various mixtures of hydrocarbon gases have been tested using cotton, coleus, tomato and other plant species. Ethylene has been found to be the most biologically active of the hydrocarbon gases studied. Controlled experiments have confirmed field observations that monocotyledonous plants such as sorghum and corn are relatively insensitive to ethylene, whereas dicotyledonous plants such as cotton, coleus, corn pea and tomato are extremely sensitive. Flower petal abscission in periwinkle and flower bud abscission in cotton have been found to be excellent indicators of extremely low levels of ethylene air pollution in both the field and in controlled experiments. Typical responses of cotton to low levels of ethylene include: lost of apical dominance with the resulting prostrate growth habit, flattening of upper stem and growing point, forcing of lateral buds, weakening of main stem, compacting of internodes, earlier and more profuse flowering with the abscission of squares, total loss of yield. 2 references.

  13. 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.

  14. Syngas Upgrading to Hydrocarbon Fuels Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Talmadge, M.; Biddy, M.; Dutta, A.; Jones, S.; Meyer, A.

    2013-03-01

    This technology pathway case investigates the upgrading of woody biomass derived synthesis gas (syngas) to hydrocarbon biofuels. While this specific discussion focuses on the conversion of syngas via a methanol intermediate to hydrocarbon blendstocks, there are a number of alternative conversion routes for production of hydrocarbons through a wide array of intermediates from syngas. Future work will also consider the variations to this pathway to determine the most economically viable and lowest risk conversion route. Technical barriers and key research needs have been identified that should be pursued for the syngas-to-hydrocarbon pathway to be competitive with petroleum-derived gasoline-, diesel- and jet-range hydrocarbon blendstocks.

  15. 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

  16. 高级氧化技术处理废水的研究进展%The Research Progress of Advanced Oxidation Technology For Wastewater Treatment

    Institute of Scientific and Technical Information of China (English)

    朱心悦; 韦新东; 蒋宝军

    2015-01-01

    Advanced catalytic oxidation technology has become an important means of treating biological degradation of toxic organic pollutants, which has been widely used in the printing and dyeing, chemical, pesticide, papermaking, electroplating and printed circuit boards, hospitals, pharmaceutical, mining, etc. According to the free radical production mode and different reaction conditions, advanced oxidation technology can be divided into photochemical oxidation, catalytic ozone oxidation, electrochemical oxidation, Fenton oxidation, catalytic wet air oxidation, ultrasonic oxidation method and so on. Advanced oxidation technology has many advantages,but some technical methods remain in the stage of experiment.So a more efficient and perfect technology should be studied to realize large-scale industrial application.%高级催化氧化技术已经成为治理生物难降解有机有毒污染物的重要手段,在印染、化工、农药、造纸、电镀和印制板、制药、医院、矿山等领域以及垃圾渗滤液等废水的处理上已经获得应用,具有很好的应用前景。根据产生自由基的方式和反应条件的不同,可将高级氧化技术分为光化学氧化法、催化臭氧氧化法、电化学氧化法、芬顿(Fenton)氧化法、催化湿式氧化法、超声氧化法等。高级氧化技术具有诸多优点,但其中一些技术方法仍处于研究实验阶段。因此,需要研究一种更高效、完善的技术,以实现大规模工业化应用。

  17. Dual-Bed Catalytic System for Direct Conversion of Methane to Liquid Hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    N.A.S.Amin; Sriraj Ammasi

    2006-01-01

    A dual-bed catalytic system is proposed for the direct conversion of methane to liquid hydrocarbons. In this system, methane is converted in the first stage to oxidative coupling of methane (OCM) products by selective catalytic oxidation with oxygen over La-supported MgO catalyst. The second bed, comprising of the HZSM-5 zeolite catalyst, is used for the oligomerization of OCM light hydrocarbon products to liquid hydrocarbons. The effects of temperature (650-800 ℃), methane to oxygen ratio (4-10), and SiO2/Al2O3 ratio of the HZSM-5 zeolite catalyst on the process are studied. At higher reaction temperatures, there is considerable dealumination of HZSM-5, and thus its catalytic performance is reduced. The acidity of HZSM-5 in the second bed is responsible for the oligomerization reaction that leads to the formation of liquid hydrocarbons. The activities of the oligomerization sites were unequivocally affected by the SiO2/Al2O3 ratio. The relation between the acidity and the activity of HZSM-5 is studied by means of TPD-NH3 techniques. The rise in oxygen concentration is not beneficial for the C5+ selectivity, where the combustion reaction of intermediate hydrocarbon products that leads to the formation of carbon oxide (CO+CO2) products is more dominant than the oligomerization reaction. The dual-bed catalytic system is highly potential for directly converting methane to liquid fuels.

  18. Zero-valent iron/iron oxide-oxyhydroxide/graphene as a magnetic sorbent for the enrichment of polychlorinated biphenyls, polyaromatic hydrocarbons and phthalates prior to gas chromatography-mass spectrometry.

    Science.gov (United States)

    Karamani, Anna A; Douvalis, Alexios P; Stalikas, Constantine D

    2013-01-04

    A composite magnetic material consisting of zero-valent iron, iron oxide-oxyhydroxide and graphene was synthesized and used successfully as a sorbent for the micro solid-phase extraction of PAHs, PCBs and phthalic acid esters. The components endow the composite with multiple characteristics such as adsorption capability and facile removal due to its magnetic properties. Due to the π-π electrostatic stacking property of graphene, the high specific surface area and the adsorption capability of both components, the resulting black flaky Fe(0)/iron oxide-oxyhydroxide/graphene composite showed high extraction efficiency for the target analytes from water samples. Compared with the neat graphene, the composite material has improved properties in terms of microextraction capabilities as both the hydrophobic graphene and zero-valent iron participate in the adsorption of the hydrophobic molecules. The precision from the extraction of all three groups of compounds was lower than 7% and the recoveries were from 90 to 93% from a spiked lake water sample. The high recoveries in relation to the low final volume of the desorption solvent ensure high preconcentration efficiency and a promising sorbent for analytical applications.

  19. Progression of natural attenuation processes at a crude-oil spill site . I. Geochemical evolution of the plume

    Science.gov (United States)

    Cozzarelli, I.M.; Bekins, B.A.; Baedecker, M.J.; Aiken, G.R.; Eganhouse, R.P.; Tuccillo, M.E.

    2001-01-01

    A 16-year study of a hydrocarbon plume shows that the extent of contaminant migration and compound-specific behavior have changed as redox reactions, most notably iron reduction, have progressed over time. Concentration changes at a small scale, determined from analysis of pore-water samples drained from aquifer cores, are compared with concentration changes at the plume scale, determined from analysis of water samples from an observation well network. The small-scale data show clearly that the hydrocarbon plume is growing slowly as sediment iron oxides are depleted. Contaminants, such as ortho-xylene that appeared not to be moving downgradient from the oil on the basis of observation well data, are migrating in thin layers as the aquifer evolves to methanogenic conditions. However, the plume-scale observation well data show that the downgradient extent of the Fe2+ and BTEX plume did not change between 1992 and 1995. Instead, depletion of the unstable Fe (III) oxides near the subsurface crude-oil source has caused the maximum dissolved iron concentration zone within the plume to spread at a rate of approximately 3 m/year. The zone of maximum concentrations of benzene, toluene, ethylbenzene and xylene (BTEX) has also spread within the anoxic plume. In monitoring the remediation of hydrocarbon-contaminated ground water by natural attenuation, subtle concentration changes in observation well data from the anoxic zone may be diagnostic of depletion of the intrinsic electron-accepting capacity of the aquifer. Recognition of these subtle patterns may allow early prediction of growth of the hydrocarbon plume. Copyright ?? 2001 .

  20. Progression of natural attenuation processes at a crude-oil spill site. I. Geochemical evolution of the plume

    Science.gov (United States)

    Cozzarelli, Isabelle M.; Bekins, Barbara A.; Baedecker, Mary Jo; Aiken, George R.; Eganhouse, Robert P.; Tuccillo, Mary Ellen

    2001-12-01

    A 16-year study of a hydrocarbon plume shows that the extent of contaminant migration and compound-specific behavior have changed as redox reactions, most notably iron reduction, have progressed over time. Concentration changes at a small scale, determined from analysis of pore-water samples drained from aquifer cores, are compared with concentration changes at the plume scale, determined from analysis of water samples from an observation well network. The small-scale data show clearly that the hydrocarbon plume is growing slowly as sediment iron oxides are depleted. Contaminants, such as ortho-xylene that appeared not to be moving downgradient from the oil on the basis of observation well data, are migrating in thin layers as the aquifer evolves to methanogenic conditions. However, the plume-scale observation well data show that the downgradient extent of the Fe 2+ and BTEX plume did not change between 1992 and 1995. Instead, depletion of the unstable Fe (III) oxides near the subsurface crude-oil source has caused the maximum dissolved iron concentration zone within the plume to spread at a rate of approximately 3 m/year. The zone of maximum concentrations of benzene, toluene, ethylbenzene and xylene (BTEX) has also spread within the anoxic plume. In monitoring the remediation of hydrocarbon-contaminated ground water by natural attenuation, subtle concentration changes in observation well data from the anoxic zone may be diagnostic of depletion of the intrinsic electron-accepting capacity of the aquifer. Recognition of these subtle patterns may allow early prediction of growth of the hydrocarbon plume.

  1. A chemical and thermodynamic model of oil generation in hydrocarbon source rocks

    Science.gov (United States)

    Helgeson, Harold C.; Richard, Laurent; McKenzie, William F.; Norton, Denis L.; Schmitt, Alexandra

    2009-02-01

    Thermodynamic calculations and Gibbs free energy minimization computer experiments strongly support the hypothesis that kerogen maturation and oil generation are inevitable consequences of oxidation/reduction disproportionation reactions caused by prograde metamorphism of hydrocarbon source rocks with increasing depth of burial.These experiments indicate that oxygen and hydrogen are conserved in the process.Accordingly, if water is stable and present in the source rock at temperatures ≳25 but ≲100 °C along a typical US Gulf Coast geotherm, immature (reduced) kerogen with a given atomic hydrogen to carbon ratio (H/C) melts incongruently with increasing temperature and depth of burial to produce a metastable equilibrium phase assemblage consisting of naphthenic/biomarker-rich crude oil, a type-II/III kerogen with an atomic hydrogen/carbon ratio (H/C) of ˜1, and water. Hence, this incongruent melting process promotes diagenetic reaction of detritus in the source rock to form authigenic mineral assemblages.However, in the water-absent region of the system CHO (which is extensive), any water initially present or subsequently entering the source rock is consumed by reaction with the most mature kerogen with the lowest H/C it encounters to form CO 2 gas and a new kerogen with higher H/C and O/C, both of which are in metastable equilibrium with one another.This hydrolytic disproportionation process progressively increases both the concentration of the solute in the aqueous phase, and the oil generation potential of the source rock; i.e., the new kerogen can then produce more crude oil.Petroleum is generated with increasing temperature and depth of burial of hydrocarbon source rocks in which water is not stable in the system CHO by a series of irreversible disproportionation reactions in which kerogens with higher (H/C)s melt incongruently to produce metastable equilibrium assemblages consisting of crude oil, CO 2 gas, and a more mature (oxidized) kerogen with a lower

  2. 蛋白质氧化机制及其评价技术研究进展%Research progress of protein oxidation mechanism and evaluation technology

    Institute of Scientific and Technical Information of China (English)

    朱卫星; 王远亮; 李宗军

    2011-01-01

    The color of meat products becomes unacceptably when they are stored for a period of time,it brings adverse impact when they are sold.It has the very big relations between meat color changes and protein oxidation in a certain extent.The research of protein oxidation in meat products may help to slow the meat color deterioration,improve the meat shelf life.The article is aim to discuss the principle of protein oxidation,the main changes after the proteins are oxidized and the evaluation of protein oxidation in order to establish the better evaluation system of protein oxidation in foods.%肉制品在贮藏一段时间后,颜色会变成让人难以接受的程度,为肉制品的销售带来不利影响。肉制品颜色的变化在一定程度上与蛋白质氧化有很大地关系。对肉制品中蛋白质氧化的研究有助于延缓肉制品颜色的劣变,提高肉制品的货架期。主要就蛋白质氧化的机理、氧化后蛋白质发生的主要变化以及氧化后蛋白质的评价技术作了阐述,旨在建立食品中蛋白质氧化的完善评价机制。

  3. Isolation and characterization of ancient hydrocarbon biomarkers from crystalline minerals

    Science.gov (United States)

    Summons, R. E.; Carrasquillo, A.; Hallmann, C.; Sherman, L. S.; Waldbauer, J. R.

    2008-12-01

    had been, somehow, enclosed within or more tightly bound to clays or carbonates. Subtle and consistent compositional differences between the freely-extractable and tightly-bound hydrocarbons provide further evidence for their syngenetic nature. The research has further applicability to biomarker studies of Early Earth materials, returned planetary samples as well as robotic analyses on flight missions. On Mars, for example, organics trapped within crystals of evaporate minerals would be protected, to a large degree, from the deleterious effects of ionizing radiation and strong oxidants that are prevalent on Mars surface. eaps.mit.edu/geobiology/

  4. Electrochemical CO2 reduction on Cu2O-derived copper nanoparticles: Controlling the catalytic selectivity of hydrocarbons

    NARCIS (Netherlands)

    Kas, Recep; Kortlever, R.; Milbrat, Alexander; Koper, M.T.M.; Mul, Guido; Baltrusaitis, Jonas

    2014-01-01

    The catalytic activity and hydrocarbon selectivity in electrochemical carbon dioxide (CO2) reduction on cuprous oxide (Cu2O) derived copper nanoparticles is discussed. Cuprous oxide films with [100], [110] and [111] orientation and variable thickness were electrodeposited by reduction of copper(II)

  5. 化学氧化预处理难浸金矿研究进展%RESEARCH PROGRESS IN CHEMICAL PRE-OXIDATION FOR REFRACTORY GOLD ORES

    Institute of Scientific and Technical Information of China (English)

    李大江

    2011-01-01

    With virtue of mild operation condition, faster oxidation velocity, lower invest cost and less pollution, refractory gold ore pre-oxidation by chemical reagent is a technique of good prospect. Nitric acid pre-oxidation, alkaline pre-oxidation, electrochemical intensive electrode and their industrial application are introduced respectively in the paper.%化学预氧化法指通过添加化学试剂的方式对矿石进行预氧化的技术,具有操作条件温和、氧化速度快、设备和生产投资费用较低、环境污染小等优点,在处理难浸金矿方面有很好的发展前景.本文分别介绍了硝酸预氧化法、碱性预氧化法和电化学强化电极法三种化学预氧化技术以及其在工业中的应用情况.

  6. 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)

  7. 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

  8. Deep desulfurization of hydrocarbon fuels

    Science.gov (United States)

    Song, Chunshan [State College, PA; Ma, Xiaoliang [State College, PA; Sprague, Michael J [Calgary, CA; Subramani, Velu [State College, PA

    2012-04-17

    The invention relates to processes for reducing the sulfur content in hydrocarbon fuels such as gasoline, diesel fuel and jet fuel. The invention provides a method and materials for producing ultra low sulfur content transportation fuels for motor vehicles as well as for applications such as fuel cells. The materials and method of the invention may be used at ambient or elevated temperatures and at ambient or elevated pressures without the need for hydrogen.

  9. 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.

  10. Abnormal pressure in hydrocarbon environments

    Science.gov (United States)

    Law, B.E.; Spencer, C.W.

    1998-01-01

    Abnormal pressures, pressures above or below hydrostatic pressures, occur on all continents in a wide range of geological conditions. According to a survey of published literature on abnormal pressures, compaction disequilibrium and hydrocarbon generation are the two most commonly cited causes of abnormally high pressure in petroleum provinces. In young (Tertiary) deltaic sequences, compaction disequilibrium is the dominant cause of abnormal pressure. In older (pre-Tertiary) lithified rocks, hydrocarbon generation, aquathermal expansion, and tectonics are most often cited as the causes of abnormal pressure. The association of abnormal pressures with hydrocarbon accumulations is statistically significant. Within abnormally pressured reservoirs, empirical evidence indicates that the bulk of economically recoverable oil and gas occurs in reservoirs with pressure gradients less than 0.75 psi/ft (17.4 kPa/m) and there is very little production potential from reservoirs that exceed 0.85 psi/ft (19.6 kPa/m). Abnormally pressured rocks are also commonly associated with unconventional gas accumulations where the pressuring phase is gas of either a thermal or microbial origin. In underpressured, thermally mature rocks, the affected reservoirs have most often experienced a significant cooling history and probably evolved from an originally overpressured system.

  11. Research progress in transition metal oxides based on conversion mechanism as the anode materials for Li-ion batteries%转化型过渡金属氧化物负极材料的研究进展

    Institute of Scientific and Technical Information of China (English)

    曾晖; 王强; 王康平; 宋金保

    2014-01-01

    综述了近年来过渡金属氧化物 MxOy (M= Fe,Ni,Co,Cu)作为锂离子电池负极材料在锂离子电池中的应用。我们分别将过渡金属氧化物的两种形态(粉体和薄膜),与电化学性能之间的关联性进行了总结和探讨,并对过渡金属氧化物作为锂离子电池负极材料的发展前景进行了展望。%In recent years,research progress on transition metal oxides MxOy(M= Fe,Ni,Co,Cu) as anode materials for lithium ion batteries was reviewed.Emphasis is placed on the generaliza-tion and discussion of the relationship between the two status (powder and films )and electro-chemical properties of transition metal oxides materials.And the development prospect of transi-tion metal oxides as anode materials is also reviewed.

  12. Progress in Research of Iron Oxide Composite Anode Materials for Li-ion Battery%氧化铁基锂离子电池负极材料研究进展

    Institute of Scientific and Technical Information of China (English)

    田嘉铭; 王静; 杨金萍; 赵清清

    2014-01-01

    铁氧化物负极材料具有理论容量高、放电平台低、合成方法简单、对环境友好等特点,受到研究者的关注。综述了铁氧化物负极材料在锂离子电池中的应用、制备方法等方面的最新研究进展,介绍了提高铁氧化物材料电化学性能的方式,提出铁氧化物负极材料可望提高锂离子电池的综合性能。%The more attention has been paid to the iron oxide anode materials for lithium ion battery due to their special characteristics such as higher theoretical capacity, low discharge potential, simple synthesis methods and friendly to the environment.Recent progress was reviewed on the applications, preparation methods of iron oxide anode materials in lithium ion batteries.The method of increasing the electrochemical performance was introduced.The iron oxide anode materials is hopeful to increase the gen-eral performances of lithium ion battery materials.

  13. Oral Administration of Aloe vera (L.) Burm. f. (Xanthorrhoeaceae) and Honey Improves the Host Body Composition and Modulates Proteolysis Through Reduction of Tumor Progression and Oxidative Stress in Rats.

    Science.gov (United States)

    Tomasin, Rebeka; de Andrade, Rafael Siqueira; Gomes-Marcondes, Maria Cristina Cintra

    2015-10-01

    Oxidative stress has a dual role in cancer; it is linked with tumorigenic events and host wasting, as well as senescence and apoptosis. Researchers have demonstrated the importance of coadjuvant therapies in cancer treatment, and Aloe vera and honey have immunomodulatory, anticancer, and antioxidant properties. The preventive and therapeutic effects of Aloe vera (L.) Burm. f. (Xanthorrhoeaceae) and honey in tumor progression and host wasting were analyzed in Walker 256 carcinoma-bearing rats. The animals were distributed into the following groups: C=control-untreated, W=tumor-untreated, WA=treated after tumor induction, A=control-treated, AW=treated before tumor induction, and AWA=treated before and after tumor induction. Proteolysis and oxidative stress were analyzed in the tumor, liver, muscle, and myocardial tissues. The results suggest that the Aloe vera and honey treatment affect the tumor and host by different mechanisms; the treatment-modulated host wasting and cachexia, whereas it promoted oxidative stress and damage in tumor tissues, particularly in a therapeutic context (WA).

  14. Research progress in H2O2/solid catalyst carrier for oxidative desulfurization%H2O2/固体催化剂氧化脱硫体系中载体的研究进展

    Institute of Scientific and Technical Information of China (English)

    王广建; 崔会杰; 冯庆吉; 韩亚飞; 王芳

    2015-01-01

    从研究应用角度出发,综述了近年来 H2O2/固体催化剂氧化脱硫体系中载体的研究进展和发展趋势,分别从单一氧化物载体、复合氧化物载体、活性炭载体、分子筛及复合分子筛载体4个方面论述了氧化脱硫催化剂载体各自的优缺点及应用成果。单一氧化物载体重点介绍了 Al2O3、TiO2、SiO2、ZrO2;复合氧化物载体主要对二元复合氧化物进行了综述;重点介绍了以 ZSM-5、SBA-15、MCM-41、HMS 为代表的分子筛及复合分子筛载体。最后将不同类型载体的结构特点、反应优缺点等进行了归纳总结,展望了氧化脱硫催化剂载体未来的研究方向,并提出分子筛及复合分子筛载体将是氧化脱硫催化剂载体研究的焦点。%The article summarizes the research progress and development of carriers in the system of oxidative desulfurization with solid catalyst H2O2. Advantages,disadvantages and application results are discussed from following four aspects:single oxide carrier,mixed oxide carrier,activated carbon carrier,molecular sieve and composite molecular sieve carrier. As single carriers,Al2O3,TiO2,SiO2 and ZrO2 are emphatically introduced; and binary compound oxides are specially introduced in mixed oxide carriers. The molecular sieve and composite molecular sieve carrier represented by ZSM-5, SBA-15,MCM-41 and HMS are also introduced emphatically. Finally,we give an induction and summarization on structural characteristics,advantages and disadvantages in the reaction of different carriers. The research tendency of oxidative desulfurization carrier is prospected,meanwhile,molecular sieve and composite molecular sieve carrier are proposed as the key research focuses of catalyst carriers for oxidative desulfurization in the future.

  15. Bacterial communities of surface and deep hydrocarbon-contaminated waters of the Deepwater Horizon oil spill

    Science.gov (United States)

    Yang, T.; Nigro, L. M.; McKay, L.; Ziervogel, K.; Gutierrez, T.; Teske, A.

    2010-12-01

    We performed a 16S rRNA gene sequencing survey of bacterial communities within oil-contaminated surface water, deep hydrocarbon plume water, and deep water samples above and below the plume to determine spatial and temporal patterns of oil-degrading bacteria growing in response to the Deepwater Horizon oil leak. In addition, we are reporting 16S rRNA sequencing results from time series incubation, enrichment and cultivation experiments. Surface oil slick samples were collected 3 nautical miles from ground zero, (5/6/10, RV Pelican) and were added to uncontaminated surface water (collected within a 30 nautical mile radius of ground zero, 5/6/10 - 5/9/10, RV Pelican). This mixture was incubated for 20 days in a rolling bottle at 25°C. 16S rRNA clone libraries from marine snow-like microbial flocs that had formed during the incubation yielded a highly diverse bacterial community, predominately composed of the Alpha- and Gammaproteobacteria, and a smaller number of Planktomycetes and other bacterial lineages. The most frequently recovered proteobacterial sequences were closely related to cultured species of the genus Cycloclasticus, specialists in aerobic oxidation of aromatic hydrocarbons. These time series incubation results will be compared to the microbial community structure of contaminated surface water, sampled on the same cruise with RV Pelican (5/6/10-5/9/10) and frozen immediately. Stable isotope probing (SIP) experiments with C13-labelled alkanes and polycyclic aromatic substrates and gulf water samples have yielded different enrichments. With naphthalene, predominantly Alteromonas-related clones and a smaller share of Cycloclasticus clones were recovered; phenanthrene yielded predominantly clones related to Cycloclasticus, and diverse other Gamma- and Alphaproteobacteria. Analyses of SIP experiments with hexadecane are in progress. The microbial community composition of the deep hydrocarbon plume was characterized using water column profile samples taken

  16. Research Progress of Relation between Oxidative Stress and Hypertension%氧化应激与高血压发病机制研究

    Institute of Scientific and Technical Information of China (English)

    万基伟; 樊小农; 王舒; 刘健

    2015-01-01

    The specific mechanism of Hypertension disease is not yet clear. Oxidative stress as one of the pathogenesis of hypertension, prove the target for prevention and treatment of Hypertension. Adjusting the oxidative stress in treating high blood pressure may become a new direction. But single use of antioxidant can hardly to repy complex process of oxidative stress. Therefore,a comprehensive under_standing of the relationship between oxidative stress and the pathogenesis of hypertension,the specific function of oxidation system and antioxidant system index in the process of occurrence and development of high blood pressure,joint use of multiple targets,multiple ways of antioxidants or enhance the capacity of the body against oxidative stress,may be better able to control high blood pressure.%高血压发病的具体机制尚不明确,氧化应激作为高血压发病机制之一,为其预防和治疗提供了靶点,通过调节机体氧化应激水平治疗高血压可能成为新的方向。然而使用作用途径单一的抗氧化剂,很难全面应对复杂的氧化应激过程。因此,全面了解氧化应激和高血压发病机制之间的关系,明确氧化系统及抗氧化系统的各种指标在高血压发生和发展过程中的具体作用,联合运用多靶点、多途径的抗氧化剂或提升机体抵御氧化应激能力的药物,或许能更好地控制高血压。

  17. 甲烷厌氧氧化微生物的研究进展%PROGRESS IN STUDY ON MICROORGANISMS RESPONSIBLE FOR ANAEROBIC OXIDATION OF METHANE

    Institute of Scientific and Technical Information of China (English)

    沈李东; 胡宝兰; 郑平

    2011-01-01

    Methane is a major greenhouse gas, which contributes estimatedly 20% to global warming. Microbially mediated anaerobic oxidation of methane (AOM) is an important way to reduce methane emission in nature. According to different coupling reactions, AOM can be divided into two types, Sulphate-dependent anaerobic methane oxidation( SAMO ) and Denitrification-dependent anaerobic methane oxidation ( DAMO ). S024- and NO2-/NO3- function as their terminal electron acceptors, separately. This review summarizes types of AOM and microorganisms involved, elaborates mechanisms of the AOMs, and discusses orientation of the future research and prospects of the application of AOM.%甲烷是一种重要的温室气体,其对全球气候变暖的贡献率约占20%.微生物进行的甲烷厌氧氧化(Anaerobic oxidation of methane,AOM)是减少自然环境中该温室气体排放的重要生物途径.根据耦联反应的不同,可将AOM分为两类,即硫酸盐还原型甲烷厌氧氧化(Sulphate-dependent anaerobic methane oxidation,SAMO)和反硝化型甲烷厌氧氧化(Denitrification-dependent anaerobic methane oxidation,DAMO),前者以SO2-4作为AOM的最终电子受体,后者以NO2-/NO3-作为AOM的最终电子受体.深入了解这两种类型AOM的发生机理,有助于更好地理解该生物过程的重要性,为AOM工艺的开发提供理论依据.鉴此,本文简要介绍了不同类型的AOM及其参与的微生物,着重阐述了其发生机理,并探讨了AOM未来的研究方向与应用前景.

  18. 纳米氧化物太阳能电池研究进展%Research Progress on Nano-Materials of Oxides for Solar Cells

    Institute of Scientific and Technical Information of China (English)

    林红; 焦星剑; 赵晓冲; 郝锋; 李建保

    2011-01-01

    The superiority and the principle of a novel, low-cost solar cells based on dye-sensitized nano-oxides (DSCs) are represented. Nano-oxides have some special applications in the photoanodes and electrolytes of DSCs. Based on our recent work on DSCs, the developments on nano-oxides for photoanodes and electrolytes are reviewed. The preparation methods of nano-oxides used in photoanodes are introduced, and the performance, such as electron transfer and recombination in photoanodes are discussed. Low-temperature methods and performances of nano-oxides used in flexible solar cells are reviewed in detail. The quasi-solid state solar cells based on nano-oxides are also presented.%介绍了新型低成本纳米氧化物染料敏化太阳能电池的优势特点及基本原理.纳米氧化物材料在染料敏化太阳能电池的光阳极和电解质中有着特殊的应用,在电池中起到了非常关键的作用.围绕电池中光阳极和电解质所用的纳米氧化物材料,结合清华大学科研实例,综述了光阳极用纳米氧化物的制备方法及性能,分析了电子传递和复合对电池性能的影响,以及纳米材料的包覆对减少电子复合的作用,指出一维纳米氧化物材料可以形成光阳极中的电荷通道.对于低温纳米氧化物薄膜成膜方法及其在柔性太阳能电池中的应用也做了详细评述.另外,还介绍了纳米氧化物在准固态太阳能电池中的应用.

  19. Analysis of the effects of exposure to acute hypoxia on oxidative lesions and tumour progression in a transgenic mouse breast cancer model

    Directory of Open Access Journals (Sweden)

    Lunt Sarah

    2008-05-01

    Full Text Available Abstract Background Tumour hypoxia is known to be a poor prognostic indicator, predictive of increased risk of metastatic disease and reduced survival. Genomic instability has been proposed as one of the potential mechanisms for hypoxic tumour progression. Both of these features are commonly found in many cancer types, but their relationship and association with tumour progression has not been examined in the same model. Methods To address this issue, we determined the effects of 6 week in vivo acute hypoxic exposure on the levels of mutagenic lipid peroxidation product, malondialdehyde, and 8-oxo-7,8-dihydro-2'-deoxyguanosine DNA (8-oxo-dG lesions in the transgenic polyomavirus middle T (PyMT breast cancer mouse model. Results We observed significantly increased plasma lipid peroxidation and 8-oxo-dG lesion levels in the hypoxia-exposed mice. Consumption of malondialdehyde also induced a significant increase in the PyMT tumour DNA lesion levels, however, these increases did not translate into enhanced tumour progression. We further showed that the in vivo exposure to acute hypoxia induced accumulation of F4/80 positive tumour-associated macrophages (TAMs, demonstrating a relationship between hypoxia and macrophages in an experimental model. Conclusion These data suggest that although exposure to acute hypoxia causes an increase in 8-oxo-dG lesions and TAMs in the PyMT tumours, these increases do not translate into significant changes in tumour progression at the primary or metastatic levels in this strong viral oncogene-driven breast cancer model.

  20. Impact of molecular structure on secondary organic aerosol formation from aromatic hydrocarbon photooxidation under low-NOx conditions

    Science.gov (United States)

    Li, Lijie; Tang, Ping; Nakao, Shunsuke; Cocker, David R., III

    2016-08-01

    The molecular structure of volatile organic compounds determines their oxidation pathway, directly impacting secondary organic aerosol (SOA) formation. This study comprehensively investigates the impact of molecular structure on SOA formation from the photooxidation of 12 different eight- to nine-carbon aromatic hydrocarbons under low-NOx conditions. The effects of the alkyl substitute number, location, carbon chain length and branching structure on the photooxidation of aromatic hydrocarbons are demonstrated by analyzing SOA yield, chemical composition and physical properties. Aromatic hydrocarbons, categorized into five groups, show a yield order of ortho (o-xylene and o-ethyltoluene) > one substitute (ethylbenzene, propylbenzene and isopropylbenzene) > meta (m-xylene and m-ethyltoluene) > three substitute (trimethylbenzenes) > para (p-xylene and p-ethyltoluene). SOA yields of aromatic hydrocarbon photooxidation do not monotonically decrease when increasing alkyl substitute number. The ortho position promotes SOA formation while the para position suppresses aromatic oxidation and SOA formation. Observed SOA chemical composition and volatility confirm that higher yield is associated with further oxidation. SOA chemical composition also suggests that aromatic oxidation increases with increasing alkyl substitute chain length and branching structure. Further, carbon dilution conjecture developed by Li et al. (2016) is extended in this study to serve as a standard method to determine the extent of oxidation of an alkyl-substituted aromatic hydrocarbon.

  1. Research progress of analysis methods on sterol oxidations%甾醇氧化物分析方法研究进展

    Institute of Scientific and Technical Information of China (English)

    侍芳; 金青哲; 王兴国

    2013-01-01

      该文介绍甾醇氧化物种类,综述目前国内外对甾醇氧化物检测方法;包括油脂提取、甾醇氧化物纯化、富集,及色谱、色谱质谱联用对其定性、定量分析方法。%This article describes the type of the sterol oxidations,it summarize the detection method of the sterol oxidations at home and abroad,including the extraction of oil,purification and enrichment, the qualitative and quantitative methods of chromatography and chromatography–mass spectrometry.

  2. STATUS AND RESEARCH PROGRESS OF ZINC OXIDE ORE FLOTATION%氧化锌矿的浮选现状与研究进展

    Institute of Scientific and Technical Information of China (English)

    宋龑; 刘全军; 常富强

    2012-01-01

    Based on related literatures at home and abroad in recent years, novel flotation reagents and process of zinc oxide ore dressing are summarized in this article, which points out that the correct new development direction of oxidized zinc ore flotation research should focus on the study of new high efficiency flotation agents and new flotation process%根据国内外近年来的相关文献,对氧化锌矿新型浮选药剂和选矿新工艺进行了综合评述,认为更有效的新型浮选药剂和浮选流程新工艺的研究是氧化锌矿浮选研究的正确发展方向.

  3. Inactivation of Protein Tyrosine Phosphatases by Peracids Correlates with the Hydrocarbon Chain Length

    OpenAIRE

    Alicja Kuban-Jankowska; Magdalena Gorska; Tuszynski, Jack A; Cassandra D M Churchill; Philip Winter; Mariusz Klobukowski; Michal Wozniak

    2015-01-01

    Background/Aims: Protein tyrosine phosphatases are crucial enzymes controlling numerous physiological and pathophysiological events and can be regulated by oxidation of the catalytic domain cysteine residue. Peracids are highly oxidizing compounds, and thus may induce inactivation of PTPs. The aim of the present study was to evaluate the inhibitory effect of peracids with different length of hydrocarbon chain on the activity of selected PTPs. Methods: The enzymatic activity of human CD45, PTP...

  4. TiO2光催化氧化技术的研究与发展%Research Progress in TiO2 Photocatalytic Oxidation Technology

    Institute of Scientific and Technical Information of China (English)

    肖俊霞; 吴贤格

    2011-01-01

    The mechanism of TiO2 photocatalytic reaction was described briefly. The ways of improving TiO2 photocatalytic activity including metal ions doping, noble metals surface deposition,nonmetals doping, co-doping, semiconductor coupling, surface photosensitization and external field coupling were introduced emphatically. The application of TiO2 photocatalytic oxidation technology were summarized including oxidation/reduction treatment to pollutants in water, oxidation treatment to volatile organic compounds in air and sterilization. Besides, based on the actual problems on TiO2 photocatalytic oxidation technology it was proposed that the mechanism research of kinetics and thermodynamics of pollutants degradation and the macroscopical reaction kinetics of photocatalytic reactor was its further development.%简述了TiO2光催化反应的机理,重点介绍了金属离子掺杂、贵金属表面沉积、非金属元素掺杂、共掺杂、半导体复合、表面光敏化及外场耦合等提高TiO2光催化性能的途径,总结了TiO2光催化氧化技术对水中污染物的氧化/还原处理、对大气中挥发性有机物的氧化处理及在抗菌消毒等方面的应用,并针对TiO2光催化氧化技术研究方面存在的问题,提出其未来的发展方向是污染物降解的动力学与热力学以及光催化反应器的宏观反应动力学的机理研究.

  5. Progress on clinical application of diluted nitric oxide available analgesic%稀释氧化亚氮速效镇痛的临床应用进展

    Institute of Scientific and Technical Information of China (English)

    李玉香; 赵继军

    2012-01-01

    国际上稀释氧化亚氮吸入镇痛作为临床有创医疗操作中,为短期镇痛所采用的有效方法之一.国内近年来主要将其用于妇科、牙科和腔镜检查的镇痛镇静.为了正确的使用稀释氧化亚氮速效镇痛技术,现综述预先配制的稀释氧化亚氮镇痛作用机制、安全性及其有关临床实践指南,为临床使用该技术提供理论依据和实践指南.%The diluted nitrous oxide inhalation analgesia was one of effective methods used for short - term analgesic in clinical invasive medical procedures in international. In recent years, it was mainly used for analgesic sedation in gynecological department,dental department and endoscopy in China. In order to use the diluted nitrous oxide available pain management techniques correctly,it reviewed the mechanism of analgesia action, security and related clinical practice guidelines of pre -prepared diluted nitrous oxide,so as to provide theoretical evidences and practical guidelines for the clinical use of the technology.

  6. Assessment of five bioaccessibility assays for predicting the efficacy of petroleum hydrocarbon biodegradation in aged contaminated soils.

    Science.gov (United States)

    Dandie, Catherine E; Weber, John; Aleer, Samuel; Adetutu, Eric M; Ball, Andy S; Juhasz, Albert L

    2010-11-01

    In this study, the bioaccessibility of petroleum hydrocarbons in aged contaminated soils (1.6-67gkg(-1)) was assessed using four non-exhaustive extraction techniques (100% 1-butanol, 100% 1-propanol, 50% 1-propanol in water and hydroxypropyl-β-cyclodextrin) and the persulfate oxidation method. Using linear regression analysis, residual hydrocarbon concentrations following bioaccessibility assessment were compared to residual hydrocarbon concentrations following biodegradation in laboratory-scale microcosms in order to determine whether bioaccessibility assays can predict the endpoint of hydrocarbon biodegradation. The relationship between residual hydrocarbon concentrations following microcosm biodegradation and bioaccessibility assessment was linear (r(2)=0.71-0.97) indicating that bioaccessibility assays have the potential to predict the extent of hydrocarbon biodegradation. However, the slope of best fit varied depending on the hydrocarbon fractional range assessed. For the C(10)-C(14) hydrocarbon fraction, the slope of best fit ranged from 0.12 to 0.27 indicating that the non-exhaustive or persulfate oxidation methods removed 3.5-8 times more hydrocarbons than biodegradation. Conversely, for the higher molecular weight hydrocarbon fractions (C(29)-C(36) and C(37)-C(40)), biodegradation removed up to 3.3 times more hydrocarbons compared to bioaccessibility assays with the resulting slope of best fit ranging from 1.0-1.9 to 2.0-3.3 respectively. For mid-range hydrocarbons (C(15)-C(28)), a slope of approximately one was obtained indicating that C(15)-C(28) hydrocarbon removal by these bioaccessibility assays may approximate the extent of biodegradation. While this study demonstrates the potential of predicting biodegradation endpoints using bioaccessibility assays, limitations of the study include a small data set and that all soils were collected from a single site, presumably resulting from a single contamination source. Further evaluation and validation is

  7. Research progress on anti-oxidative mechanism of epigallocatechin gallate%表没食子儿茶素没食子酸酯抗氧化作用机制的研究进展

    Institute of Scientific and Technical Information of China (English)

    刘婷婷; 孟馨

    2016-01-01

    表没食子儿茶素没食子酸酯(EGCG)是绿茶中的主要儿茶素,大量研究表明绿茶在治疗严重慢性疾病如心血管病、神经退行性病变、肿瘤、代谢综合征、2型糖尿病等方面发挥了积极的生物学作用。绿茶的这种保护性作用主要归因于EGCG强有力的抗氧化活性。EGCG的抗氧化作用机制主要包括清除自由基、金属螯合、抑制细胞信号转导通路、调节氧化和抗氧化酶系等。综述了其抗氧化机制的研究进展,以期为临床应用及开发相同或相似机制的药物提供理论依据。%Epigallocatechin gallate (EGCG) is the main catechin in green tea. A large number of researches have revealed that green tea demonstrates a wide range of positive biological activities against serious chronic diseases, such as cardiovascular disease, neurodegenerative disorders, cancer, metabolic syndrome, and type 2 diabetes. These protective properties can be traced back to the potent antioxidant activities of EGCG. Recent studies have suggested that EGCG may exert its anti-oxidant effects by scavenging free radicals, metal chelation, inhibition of transcription factor activation, and adjusting the oxidation and anti-oxidant enzyme system, etc. This paper summarizes the research progress on anti-oxidative mechanism of EGCG, in order to provide reference for exploiting drugs with same or similar mechanism of EGCG for clinical application.

  8. 二氧化碳与环氧环己烷共聚的研究进展%Progress in study on copolymerization of carbon dioxide with cyclohexene oxide

    Institute of Scientific and Technical Information of China (English)

    徐宾

    2011-01-01

    A review is provided of the current status, progress, and new trend of the research on various catalysts applicable to copolymerization of carbon dioxide and cyclohexene oxide. It is pointed out that, as a kind of cheap, abundant, and non-toxic starting materials, carbon dioxide can be adopted to copolymerize with cyclohexene oxide so as to synthesize aliphatic polycarbonate copolymers possessing good biodegradability. However, the copolymerization of carbon dioxide with cyclohexene oxide is nearly infeasible under common conditions, because carbon dioxide is highly chemically stable and has a high thermodynamic stability. Therefore, it is imperative to develop novel catalysts with high efficiency and selectivity for the copolymerization of carbon dioxide and cyclohexene oxide.%综述了国内外用于二氧化碳与环氧环己烷共聚的各类催化剂的研究现状、进展及研发新动向.指出二氧化碳作为一种廉价、无毒、可循环利用的理想原料,利用其和环氧环己烷共聚可合成具有良好生物降解性能的脂肪族聚碳酸酯.但二氧化碳具有较高的热力学稳定性,其和环氧环己烷共聚过程在一般情况下难以实现,故迫切需要开发高效、高选择性的催化剂.

  9. Progress of reduction methods of graphene oxide%氧化石墨烯还原方法的研究进展

    Institute of Scientific and Technical Information of China (English)

    吴婕

    2013-01-01

      石墨烯的制备对于石墨烯的理论研究和应用研究起着重要的作用,化学氧化还原法是制备石墨烯最为重要的方法之一。综述了近年来氧化石墨烯的还原剂还原法、高温热处理还原法、电化学还原法、溶剂热还原法、催化还原法、微波还原法等多种还原方法,分析了目前各种常用还原方法的优缺点,并进一步提出氧化石墨烯还原方法未来的几个研究方向:还原前后原子结构变化及还原机理研究;新型还原方法或多种还原方法联用的研究;还原氧化石墨烯和制备复合物同时进行的研究。%Preparation of graphene plays an important role in theoretical and applied research of graphene. Chemical reduction of exfoliated graphite oxide (graphene oxide) appears to be one of the most important routes for graphene production available at present. In this paper,reduction methods of graphene oxide,such as using reducing agent reduction,thermal treatment reduction,electrochemical reduction,solvothermal reduction,catalytic reduction and microwave reduction are summarized,and the advantages and disadvantages are also analyzed. The research directions of the reduction methods of graphene oxide are discussed,such as changes in atomic structure after reduction and reduction mechanism,new reduction method and integration of two or more reduction methods,simultaneous reduction of graphene oxide and preparation of compounded graphene.

  10. Predicting bioremediation of hydrocarbons: laboratory to field scale.

    Science.gov (United States)

    Diplock, E E; Mardlin, D P; Killham, K S; Paton, G I

    2009-06-01

    There are strong drivers to increasingly adopt bioremediation as an effective technique for risk reduction of hydrocarbon impacted soils. Researchers often rely solely on chemical data to assess bioremediation efficiently, without making use of the numerous biological techniques for assessing microbial performance. Where used, laboratory experiments must be effectively extrapolated to the field scale. The aim of this research was to test laboratory derived data and move to the field scale. In this research, the remediation of over thirty hydrocarbon sites was studied in the laboratory using a range of analytical techniques. At elevated concentrations, the rate of degradation was best described by respiration and the total hydrocarbon concentration in soil. The number of bacterial degraders and heterotrophs as well as quantification of the bioavailable fraction allowed an estimation of how bioremediation would progress. The response of microbial biosensors proved a useful predictor of bioremediation in the absence of other microbial data. Field-scale trials on average took three times as long to reach the same endpoint as the laboratory trial. It is essential that practitioners justify the nature and frequency of sampling when managing remediation projects and estimations can be made using laboratory derived data. The value of bioremediation will be realised when those that practice the technology can offer transparent lines of evidence to explain their decisions.

  11. SEISMIC EVALUATION OF HYDROCARBON SATURATION IN DEEP-WATER RESERVOIRS

    Energy Technology Data Exchange (ETDEWEB)

    M. Batzle; D-h Han; R. Gibson; O. Djordjevic

    2003-03-20

    The ''Seismic Evaluation of Hydrocarbon Saturation in Deep-Water Reservoirs'' (Grant/Cooperative Agreement DE-FC26-02NT15342) began September 1, 2002. During this second quarter: A Direct Hydrocarbon Indicator (DHI) symposium was held at UH; Current DHI methods were presented and forecasts made on future techniques; Dr. Han moved his laboratory from HARC to the University of Houston; Subcontracts were re-initiated with UH and TAMU; Theoretical and numerical modeling work began at TAMU; Geophysical Development Corp. agreed to provide petrophysical data; Negotiations were begun with Veritas GDC to obtain limited seismic data; Software licensing and training schedules were arranged with Paradigm; and Data selection and acquisition continues. The broad industry symposium on Direct Hydrocarbon Indicators was held at the University of Houston as part of this project. This meeting was well attended and well received. A large amount of information was presented, not only on application of the current state of the art, but also on expected future trends. Although acquisition of appropriate seismic data was expected to be a significant problem, progress has been made. A 3-D seismic data set from the shelf has been installed at Texas A&M University and analysis begun. Veritas GDC has expressed a willingness to provide data in the deep Gulf of Mexico. Data may also be available from TGS.

  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. Contribution of methyl group to secondary organic aerosol formation from aromatic hydrocarbon photooxidation

    Science.gov (United States)

    Li, Lijie; Qi, Li; Cocker, David R.

    2017-02-01

    The complete atmospheric oxidation pathways leading to secondary organic aerosol remain elusive for aromatic compounds including the role of methyl substitutes on oxidation. This study investigates the contribution of methyl group to Secondary Organic Aerosol (SOA) formation during the photooxidation of aromatic hydrocarbons under low NOx condition by applying methyl carbon labeled aromatic hydrocarbons ((13C2) m-xylene and (13C2) p-xylene). Particle and gas phase oxidation products are analyzed by a series of mass spectrometers (HR-TOF-AMS, PTR-MS and SIFT-MS). The methyl group carbon containing oxidation products partition to the particle-phase at a lower rate than the carbons originating from the aromatic ring as a result of ring opening reactions. Further, the methyl carbon in the original aromatic structure is at least 7 times less likely to be oxidized when forming products that partition to SOA than the aromatic ring carbon. Therefore, oxidation of the methyl group in xylenes exerts little impact on SOA formation in current study. This study provides supporting evidence for a recent finding - a similarity in the SOA formation and composition from aromatic hydrocarbons regardless of the alkyl substitutes.

  14. Squared exponential covariance function for prediction of hydrocarbon in seabed logging application

    Science.gov (United States)

    Mukhtar, Siti Mariam; Daud, Hanita; Dass, Sarat Chandra

    2016-11-01

    Seabed Logging technology (SBL) has progressively emerged as one of the demanding technologies in Exploration and Production (E&P) industry. Hydrocarbon prediction in deep water areas is crucial task for a driller in any oil and gas company as drilling cost is very expensive. Simulation data generated by Computer Software Technology (CST) is used to predict the presence of hydrocarbon where the models replicate real SBL environment. These models indicate that the hydrocarbon filled reservoirs are more resistive than surrounding water filled sediments. Then, as hydrocarbon depth is increased, it is more challenging to differentiate data with and without hydrocarbon. MATLAB is used for data extractions for curve fitting process using Gaussian process (GP). GP can be classified into regression and classification problems, where this work only focuses on Gaussian process regression (GPR) problem. Most popular choice to supervise GPR is squared exponential (SE), as it provides stability and probabilistic prediction in huge amounts of data. Hence, SE is used to predict the presence or absence of hydrocarbon in the reservoir from the data generated.

  15. 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.

  16. 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...

  17. 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....

  18. 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...

  19. 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...

  20. Biodegradation of Aromatic Hydrocarbons in an Extremely Acidic Environment

    Science.gov (United States)

    Stapleton, Raymond D.; Savage, Dwayne C.; Sayler, Gary S.; Stacey, Gary

    1998-01-01

    The potential for biodegradation of aromatic hydrocarbons was evaluated in soil samples recovered along gradients of both contaminant levels and pH values existing downstream of a long-term coal pile storage basin. pH values for areas greatly impacted by runoff from the storage basin were 2.0. Even at such a reduced pH, the indigenous microbial community was metabolically active, showing the ability to oxidize more than 40% of the parent hydrocarbons, naphthalene and toluene, to carbon dioxide and water. Treatment of the soil samples with cycloheximide inhibited mineralization of the aromatic substrates. DNA hybridization analysis indicated that whole-community nucleic acids recovered from these samples did not hybridize with genes, such as nahA, nahG, nahH, todC1C2, and tomA, that encode common enzymes from neutrophilic bacteria. Since these data suggested that the degradation of aromatic compounds may involve a microbial consortium instead of individual acidophilic bacteria, experiments using microorganisms isolated from these samples were initiated. While no defined mixed cultures were able to evolve 14CO2 from labeled substrates in these mineralization experiments, an undefined mixed culture including a fungus, a yeast, and several bacteria successfully metabolized approximately 27% of supplied naphthalene after 1 week. This study shows that biodegradation of aromatic hydrocarbons can occur in environments with extremely low pH values. PMID:9797263

  1. Microplasma reforming of hydrocarbons for fuel cell power

    Science.gov (United States)

    Besser, R. S.; Lindner, P. J.

    The implementation of a microplasma approach for small scale reforming processes is explored as an alternative to more standard catalyst-based processes. Plasmas are a known approach to activating a chemical reaction in place of catalysts, and microplasmas are particularly attractive owing to their extremely high electron and power densities. Their inherent compactness gives them appeal for portable applications, but their modularity leads to scalability for higher capacity. We describe the realization of experimental microplasma reactors based on the microhollow cathode discharge (MHCD) structure by silicon micromachining for device fabrication. Experiments were carried out with model hydrocarbons methane and butane in the reactors within a microfluidic flow and analytical setup. We observe several key phenomena, including the ability to liberate hydrogen from the hydrocarbons at temperatures near ambient and sub-Watt input power levels, the tendency toward hydrocarbon decomposition rather than oxidation even in the presence of oxygen, and the need for a neutral carrier to obtain conversion. Mass and energy balances on these experiments revealed conversions up to nearly 50%, but the conversion of electrical power input to chemical reaction enthalpy was only on the order of 1%. These initial, exploratory results were recorded with devices and at process settings without optimization, and are hence promising for an emerging, catalyst-free reforming approach.

  2. Perovskite catalysts for oxidative coupling

    Science.gov (United States)

    Campbell, Kenneth D.

    1991-01-01

    Perovskites of the structure A.sub.2 B.sub.2 C.sub.3 O.sub.10 are useful as catalysts for the oxidative coupling of lower alkane to heavier hydrocarbons. A is alkali metal; B is lanthanide or lanthanum, cerium, neodymium, samarium, praseodymium, gadolinium or dysprosium; and C is titanium.

  3. Catalyst mixture for aromatic hydrocarbon synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Minderhoud, J.K.; Huizinga, T.; Sie, S.T.

    1989-06-06

    The present invention is concerned with catalyst mixtures consisting of two catalysts, characterized in that one, which is based on zinc, is capable of catalysing the conversion of a H/sub 2//CO mixture into oxygen-containing organic compounds, and the other is a crystalline iron/boron silicate which, after one hour's calcination in air at 500/sup 0/C, has the following properties: a certain X-ray powder diffraction pattern and, in the formula that represents the composition of the silicate, expressed in moles of the oxides, a SiO/sub 2//Fe/sub 2/O/sub 3 molar ratio that is 20-2000, a SiO/sub 2//B/sub 2/O/sub 3/ molar ratio 50-5000, and a Fe/sub 2/O/sub 3//B/sub 2/O/sub 3/ molar ratio higher than 1.0. Said catalyst mixtures show higher aromatics selectivity in the preparation of hydrocarbon mixtures from H/sub 2//CO mixtures than such a mixture comprising an iron silicate instead of the above iron/boron silicates. 3 tabs.

  4. 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.

  5. Methane and other hydrocarbon gases in sediment from the southeastern North American continental margin

    Science.gov (United States)

    Kvenvolden, K.A.; Lorenson, T.D.

    2000-01-01

    Residual concentrations and distributions of hydrocarbon gases from methane to n-heptane were measured in sediments at seven sites on Ocean Drilling Program (ODP) Leg 164. Three sites were drilled at the Cape Fear Diapir of the Carolina Rise, and one site was drilled on the Blake Ridge Diapir. Methane concentrations at these sites result from microbial generation which is influenced by the amount of pore-water sulfate and possible methane oxidation. Methane hydrate was found at the Blake Ridge Diapir site. The other hydrocarbon gases at these sites are likely the produce of early microbial processes. Three sites were drilled on a transect of holes across the crest of the Blake Ridge. The base of the zone of gas-hydrate occurrence was penetrated at all three sites. Trends in hydrocarbon gas distributions suggest that methane is microbial in origin and that the hydrocarbon gas mixture is affected by diagenesis, outgassing, and, near the surface, by microbial oxidation. Methane hydrate was recovered at two of these three sites, although gas hydrate is likely present at all three sites. The method used here for determining amounts of residual hydrocarbon gases has its limitations and provides poor assessment of gas distributions, particularly in the stratigraphic interval below about ~ 100 mbsf. One advantage of the method, however, is that it yields sufficient quantities of gas for other studies such as isotopic determinations.

  6. 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)

  7. Role of NADPH oxidases in inducing a selective increase of oxidant stress and cyclin D1 and checkpoint 1 over-expression during progression to human gastric adenocarcinoma.

    Science.gov (United States)

    Montalvo-Javé, Eduardo E; Olguín-Martínez, Marisela; Hernández-Espinosa, Diego R; Sánchez-Sevilla, Lourdes; Mendieta-Condado, Edgar; Contreras-Zentella, Martha L; Oñate-Ocaña, Luis F; Escalante-Tatersfield, Tomás; Echegaray-Donde, Agustín; Ruiz-Molina, Juan M; Herrera, Miguel F; Morán, Julio; Hernández-Muñoz, Rolando

    2016-04-01

    Gastric cancer is one of the main causes of global mortality. Here, reactive oxygen species (ROS) could largely contribute to gastric carcinogenesis. Hence, the present work was aimed to assess the role of ROS, oxidant status, NADPH oxidases (NOXs) expression, during human gastric adenocarcinoma. We obtained subcellular fraction from samples of gastric mucosa taken from control subjects (n = 20), and from 40 patients with gastric adenocarcinoma, as well as samples of distant areas (tumour-free gastric mucosa). Parameters indicative of lipid peroxidation and cell proliferation were selectively increased in both tumour-free and in cancerous gastric mucosa, despite of glutathione (GSH) content, glutathione reductase (GR) and superoxide dismutase (SOD) activities were increased in the adenocarcinoma. These high levels of antioxidant defences inversely correlated with down-regulated expression for NOX2 and 4; however, over-expression of NOX1 occurred with increased caspase-3 activity and overexpressed checkpoint 1 (MDC1) and cyclin D1 proteins. In the tumour-free mucosa an oxidant stress took place, without changing total GSH but with decreased activities for GR and mitochondrial SOD; moreover, over-expression of checkpoint 1 (MDC1) correlated with lower NOX2 and 4 expression in this mucosa. Chronically injured gastric mucosa increases lipoperoxidative events and cell proliferation. In the adenocarcinoma, cell proliferation was further enhanced, oxidant stress decreased which seemed to be linked to NOX1, MDC1 and cyclin D1 over-expression, but with a lower NOXs activity leading a 'low tone' of ROS formation. Therefore, our results could be useful for early detection and treatment of gastric adenocarcinoma. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Effects of vanadium(V)-substitution on the oxidative properties of α-Keggin-type heteropolyanion clusters——progress in DFT theoretical studies

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The redox properties of α-Keggin-type heteropolyanion clusters [XM12O40]n-(X = Si,P; M = Mo,W) mainly depend on their constituent outer metal-oxygen cages {M12O36}. They act as "reservoirs",through which the transfer and transition of electrons and protons may occur. At the atomic and molecular level,the redox properties of these clusters can be controlled and also tuned by modifying the metal M in the cages and the central heteroatom X of the clusters. Combined with relevant experimental results,this review summarizes our recent theoretical investigations of the effect of vanadium substitution on the redox properties of Keggin anion clusters. Theoretical modeling and calculation results showed that the oxidative ability of the modified species was increased by partial substitution of the cage M atoms of the Keggin clusters by vanadium atoms which have lower electronegativity. A linear correlation between the catalytic efficiency per vanadium atom and the microstructures of the vanadium(V)-substituted heteropolyanions [PVnMo12-nO40](3+n)-(n = 1-3) was established for the first time. This relationship may be suitable to interpret the catalytic behavior of the title compounds in the hydroxylation of benzene to phenol,and may also be used in understanding other reactions such as the oxidative dehydrogenation of isobutyric acid and the nitration of adamantine. The establishment of this nearly linear structure-property relationship may lay the foundations of understanding the behavior of the title compounds in homogeneous catalytic oxidation reactions,and may direct the design of future catalysts and the choice of other catalytic reactions.

  9. 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.

  10. Recent Progress in the Preparation and Applications of Bismuth Based Oxide-graphene Composite Photocatalysts%铋系氧化物-石墨烯复合光催化剂的制备及应用进展

    Institute of Scientific and Technical Information of China (English)

    董玉玉; 孙毅男; 郭亚杰; 王广健

    2016-01-01

    Recent progress on the preparation and applications of grapheme/bismuth-based oxide photocatalyt⁃ic.Their preparation and applications focus on photocatalytic degradation of organic pollutants ,and photocata⁃lytic degradation of dye.The future development was prospected.%综述铋系氧化物-石墨烯复合光催化剂的制备,并介绍复合材料在光催化降解有机污染物、光催化降解有机染料、光催化净化污水、电极材料等方面的应用,并对其未来发展方向进行展望。

  11. 无水溶胶-凝胶法制备非氧化物陶瓷的研究进展%Research Progress in Fabrication of Non-Oxide Ceramics via Non-Aqueous Sol-Gel Method

    Institute of Scientific and Technical Information of China (English)

    李书宏; 张宗波; 罗永明; 徐彩虹

    2012-01-01

    综述了基于氨解、胺解以及碳化二亚胺化三类反应的无水相溶胶-凝胶方法在制备SiCN、B(C)N、SiN、BN等非氧化物陶瓷材料方面的研究进展,并对其前景进行了展望.%This review mainly summarized recent progress on the fabrication of non-oxide ceramics, such as SiCN, BN, B ( C ) N, and SiN, by the non-aqueous sol-gel method, on the basis of ammonolysis reaction, aminolysis reaction, and the carbodiimide reaction. Future prospects of the method were also discussed.

  12. Research Progress on Catalytic Wet Air Oxidation for Treating Highly Concentrated Wastewater%催化湿式氧化处理高浓度有机废水的研究进展

    Institute of Scientific and Technical Information of China (English)

    李云; 袁志文

    2013-01-01

    The reaction principle,technical flow and catalyst research progress of catalytic wet air oxidation technology were introduced.Its application in wastewater treatment was analyzed and summarized.The problems existing in current application were reviewed,and some pieces of advice about the research were proposed.%介绍了催化湿式氧化技术的反应原理、工艺流程以及近些年来不同种催化剂的研究进展,分析和归纳了催化湿式氧化技术在污水处理中的应用现状,对实际应用中出现的问题进行了总结,并提出了一些建议.

  13. Research Progress on Molecular Mechanisms of Arsenic- induced Oxidative Stress%砷的氧化应激分子机制研究进展

    Institute of Scientific and Technical Information of China (English)

    白彩军; 刘丹; 李冰

    2012-01-01

    砷暴露能够引起多种疾病和病理损伤.目前氧化应激机制是砷毒性的研究热点.砷通过扰乱氧化/抗氧化平衡,从而引起细胞信号通路和转录因子活性、细胞周期和细胞凋亡、线粒体、抗氧化物酶的活性、抗氧化防御系统等方面的改变.本文将就砷的氧化应激分子机制的研究进展进行综述.%Arsenic exposure can cause a variety of diseases and pathological damages. In recent years, oxidative stress mechanism has been considered to be the research focus of arsenic toxicity. Arsenic alters multiple cellular pathways and transcription factor activities, cell cycle and cell apoptosis, mitochondria, antioxidant enzymes activity, and antioxidant defense system by disturbing the pro/antioxidant balance. This review summarizes the molecular mechanism of arsenic- induced oxidative stress.

  14. 2013 Survey of Non-Starch Ethanol and Renewable Hydrocarbon Biofuels Producers

    Energy Technology Data Exchange (ETDEWEB)

    Schwab, Amy [National Renewable Energy Lab. (NREL), Golden, CO (United States); Geiger, Jesse [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lewis, John [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-01-01

    In order to understand the status of the industry for non-starch ethanol and renewable hydrocarbon biofuels as of the end of calendar year 2013, the National Renewable Energy Laboratory (NREL) conducted the first of what is anticipated to be an annual survey of U.S. non-starch ethanol and renewable hydrocarbon biofuels producers. This report presents the results of this initial survey and describes the survey methodology. Subsequent surveys will report on the progress over time of the development of these facilities and companies.

  15. Photocatalytic oxidation of methane over silver decorated zinc oxide nanocatalysts.

    Science.gov (United States)

    Chen, Xuxing; Li, Yunpeng; Pan, Xiaoyang; Cortie, David; Huang, Xintang; Yi, Zhiguo

    2016-07-20

    The search for active catalysts that efficiently oxidize methane under ambient conditions remains a challenging task for both C1 utilization and atmospheric cleansing. Here, we show that when the particle size of zinc oxide is reduced down to the nanoscale, it exhibits high activity for methane oxidation under simulated sunlight illumination, and nano silver decoration further enhances the photo-activity via the surface plasmon resonance. The high quantum yield of 8% at wavelengths oxide nanostructures shows great promise for atmospheric methane oxidation. Moreover, the nano-particulate composites can efficiently photo-oxidize other small molecular hydrocarbons such as ethane, propane and ethylene, and in particular, can dehydrogenize methane to generate ethane, ethylene and so on. On the basis of the experimental results, a two-step photocatalytic reaction process is suggested to account for the methane photo-oxidation.

  16. 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

  17. 乳酸菌缓解肠道氧化应激研究进展%Research Progress in Relieve Effect of Lactobacillus in Intestinal Oxidative Stress

    Institute of Scientific and Technical Information of China (English)

    李维; 孙开济; 孙玉丽; 季昀; 周智旋; 戴兆来; 武振龙; 伍国耀

    2016-01-01

    Free radicals production increase or scavenging capacity decrease can cause free radical accumulation in mammal body.Excess amount of free radicals can damage DNA, lipids, proteins and other biological mac-romolecules in intestinal tissue, resulting in intestinal oxidative stress, affecting the absorption and utilization of nutrients, and even animal growth and development.Therefore, to reduce the intestinal damage caused by oxi-dative stress through nutrition regulation to maintenance of the animal gut and overall health has important sig-nificance.Lactobacillus, th e important part of body’ s innate immune system, can maintain intestinal mucosal barrier function and intestinal micro ecological balance, it can also enhance immunity, promote animal growth, and maintain intestinal and overall health.From the perspective of intestinal barrier function, we reviewed the possible mechanism of Lactobacillus relieve intestinal oxidative stress and antioxidant function, in order to pro-viding a depth understanding for Lactobacillus antioxidant function and scientific applications.%哺乳动物体内自由基产生增多或机体清除自由基能力下降会造成自由基在体内大量蓄积。过量的自由基破坏肠道组织中DNA、脂质、蛋白质等生物大分子,造成肠道氧化应激损伤,影响营养物质的吸收、利用和动物的生长发育。因此,通过营养调控措施减少氧化应激引起的肠道损伤,对于维持动物肠道及整体健康具有重要的意义。乳酸菌作为机体先天性免疫系统的重要组成部分,能维护肠黏膜屏障功能及肠道内微生态平衡,并增强机体免疫力,促进动物的生长,保持肠道及整体健康。本文从小肠黏膜屏障功能的角度,综述了乳酸菌对肠道氧化应激的缓解作用及其通过抗氧化功能发挥益生作用的可能机制,为乳酸菌抗氧化作用的深入认识和科学应用提供参考。

  18. 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.

  19. 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.

  20. 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.