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Sample records for monoxide nitrogen dioxide

  1. Personal Exposure Monitoring of Particulate Matter, Nitrogen Dioxide, and Carbon Monoxide, including Susceptible Groups

    National Research Council Canada - National Science Library

    R. M. Harrison; C. A. Thornton; R. G. Lawrence; D. Mark; R. P. Kinnersley; J. G. Ayres

    2002-01-01

    Aims: To investigate the relation between personal exposures to nitrogen dioxide, carbon monoxide, and PM10, and exposures estimated from static concentrations of these pollutants measured within the same...

  2. Effects of carbon monoxide and nitrogen dioxide on garden pea and string bean

    Energy Technology Data Exchange (ETDEWEB)

    Chakrabarti, A.G.

    1976-02-01

    Garden Peas (Pisum Sativum) and beans (Phaseolus vulgaris) were exposed to 24 ppM of carbon monoxide (CO) and nitrogen dioxide (NO/sub 2/). Germination of bean seeds was delayed about 48 hours. On the 18th day after exposure none of the bean seedlings exposed to NO/sub 2/ survived while about 30 percent of the beans exposed to CO survived. The survival of the pea seedlings was not affected. No effect was noted on stem length. Formation of new leaves was decreased and dropping of old leaves was increased in both test species with more drastic effects noted in the beans. (JTE)

  3. Foliage plants for indoor removal of the primary combustion gases carbon monoxide and nitrogen dioxide

    Science.gov (United States)

    Wolverton, B. C.; Mcdonald, R. C.; Mesick, H. H.

    1985-01-01

    Foliage plants were evaluated for their ability to sorb carbon monoxide and nitrogen dioxide, the two primary gases produced during the combustion of fossil fuels and tobacco. The spider plant (Chlorophytum elatum var. vittatum) could sorb 2.86 micrograms CO/sq cm leaf surface in a 6 h photoperiod. The golden pothos (Scindapsus aureus) sorbed 0.98 micrograms CO/sq cm leaf surface in the same time period. In a system with the spider plant, greater than or equal to 99 percent of an initial concentration of 47 ppm NO2 could be removed in 6 h from a void volume of approximately 0.35 cu m. One spider plant potted in a 3.8 liter container can sorb 3300 micrograms CO and effect the removal of 8500 micrograms NO2/hour, recognizing the fact that a significant fraction of NO2 at high concentrations will be lost by surface sorption, dissolving in moisture, etc.

  4. Data assimilation of satellite retrieved ozone, carbon monoxide and nitrogen dioxide with ECMWF's Composition-IFS

    Directory of Open Access Journals (Sweden)

    A. Inness

    2015-02-01

    Full Text Available Daily global analyses and 5 day forecasts are generated in the context of the European Monitoring Atmospheric Composition and Climate (MACC project using an extended version of the Integrated Forecasting System (IFS of the European Centre for Medium-Range Weather Forecasts (ECMWF. IFS now includes modules for chemistry, deposition and emission of reactive gases, aerosols, and greenhouse gases, and the 4-dimensional variational data assimilation scheme makes use of multiple satellite observations of atmospheric composition in addition to meteorological observations. This paper describes the data assimilation setup of the new Composition-IFS (C-IFS with respect to reactive gases and validates analysis fields of ozone (O3, carbon monoxide (CO, and nitrogen dioxide (NO2 for the year 2008 against independent observations and a control run without data assimilation. The largest improvement in CO by assimilation of MOPITT CO columns is seen in the lower troposphere of the Northern Hemisphere (NH Extratropics during winter, and during the South African biomass burning season. The assimilation of several O3 total column and stratospheric profile retrievals greatly improves the total column, stratospheric and upper tropospheric O3 analysis fields relative to the control run. The impact on lower tropospheric ozone, which comes from the residual of the total column and stratospheric profile O3 data, is smaller, but nevertheless there is some improvement particularly in the NH during winter and spring. The impact of the assimilation of OMI tropospheric NO2 columns is small because of the short lifetime of NO2, suggesting that NO2 observations would be better used to adjust emissions instead of initial conditions. The results further indicate that the quality of the tropospheric analyses and of the stratospheric ozone analysis obtained with the C-IFS system has improved compared to the previous "coupled" model system of MACC.

  5. GASP - THERMODYNAMIC AND TRANSPORT PROPERTIES OF HELIUM, METHANE, NEON, NITROGEN, CARBON MONOXIDE, CARBON DIOXIDE, OXYGEN, AND ARGON

    Science.gov (United States)

    Hendricks, R. C.

    1994-01-01

    A computer program, GASP, has been written to calculate the thermodynamic and transport properties of argon, carbon dioxide, carbon monoxide, fluorine, methane, neon, nitrogen, and oxygen. GASP accepts any two of pressure, temperature, or density as input. In addition, entropy and enthalpy are possible inputs. Outputs are temperature, density, pressure, entropy, enthalpy, specific heats, expansion coefficient, sonic velocity, viscosity, thermal conductivity, and surface tension. A special technique is provided to estimate the thermal conductivity near the thermodynamic critical point. GASP is a group of FORTRAN subroutines. The user typically would write a main program that invoked GASP to provide only the described outputs. Subroutines are structured so that the user may call only those subroutines needed for his particular calculations. Allowable pressures range from 0.l atmosphere to 100 to l,000 atmospheres, depending on the fluid. Similarly, allowable pressures range from the triple point of each substance to 300 degrees K to 2000 degrees K, depending on the substance. The GASP package was developed to be used with heat transfer and fluid flow applications. It is particularly useful in applications of cryogenic fluids. Some problems associated with the liquefication, storage, and gasification of liquefied natural gas and liquefied petroleum gas can also be studied using GASP. This program is written in FORTRAN IV for batch execution and is available for implementation on IBM 7000 series computers. GASP was developed in 1971.

  6. GASP - THERMODYNAMIC AND TRANSPORT PROPERTIES OF HELIUM, METHANE, NEON, NITROGEN, CARBON MONOXIDE, CARBON DIOXIDE, OXYGEN, AND ARGON

    Science.gov (United States)

    Hendricks, R. C.

    1994-01-01

    A computer program, GASP, has been written to calculate the thermodynamic and transport properties of argon, carbon dioxide, carbon monoxide, fluorine, methane, neon, nitrogen, and oxygen. GASP accepts any two of pressure, temperature, or density as input. In addition, entropy and enthalpy are possible inputs. Outputs are temperature, density, pressure, entropy, enthalpy, specific heats, expansion coefficient, sonic velocity, viscosity, thermal conductivity, and surface tension. A special technique is provided to estimate the thermal conductivity near the thermodynamic critical point. GASP is a group of FORTRAN subroutines. The user typically would write a main program that invoked GASP to provide only the described outputs. Subroutines are structured so that the user may call only those subroutines needed for his particular calculations. Allowable pressures range from 0.l atmosphere to 100 to l,000 atmospheres, depending on the fluid. Similarly, allowable pressures range from the triple point of each substance to 300 degrees K to 2000 degrees K, depending on the substance. The GASP package was developed to be used with heat transfer and fluid flow applications. It is particularly useful in applications of cryogenic fluids. Some problems associated with the liquefication, storage, and gasification of liquefied natural gas and liquefied petroleum gas can also be studied using GASP. This program is written in FORTRAN IV for batch execution and is available for implementation on IBM 7000 series computers. GASP was developed in 1971.

  7. Highly-resolved Modeling of Emissions and Concentrations of Carbon Monoxide, Carbon Dioxide, Nitrogen Oxides, and Fine Particulate Matter in Salt Lake City, Utah

    Science.gov (United States)

    Mendoza, D. L.; Lin, J. C.; Mitchell, L.; Ehleringer, J. R.

    2014-12-01

    Accurate, high-resolution data on air pollutant emissions and concentrations are needed to understand human exposures and for both policy and pollutant management purposes. An important step in this process is also quantification of uncertainties. We present a spatially explicit and highly resolved emissions inventory for Salt Lake County, Utah, and trace gas concentration estimates for carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NOx) and fine particles (PM2.5) within Salt Lake City. We assess the validity of this approach by comparing measured concentrations against simulated values derived from combining the emissions inventory with an atmospheric model. The emissions inventory for the criteria pollutants was constructed using the 2011 National Emissions Inventory (NEI). The spatial and temporal allocation methods from the Emission Modeling Clearinghouse data set are used to downscale the NEI data from annual to hourly scales and from county-level to 500 m x 500 m resolution. Onroad mobile source emissions were estimated by combining a bottom-up emissions calculation approach for large roadway links with a top-down spatial allocation approach for other roadways. Vehicle activity data for road links were derived from automatic traffic responder data. The emissions inventory for CO2 was obtained from the Hestia emissions data product at an hourly, building, facility, and road link resolution. The AERMOD and CALPUFF dispersion models were used to transport emissions and estimate air pollutant concentrations at an hourly temporal and 500 m x 500 m spatial resolution. Modeled results were compared against measurements from a mobile lab equipped with trace gas measurement equipment traveling on pre-determined routes in the Salt Lake City area. The comparison between both approaches to concentration estimation highlights spatial locations and hours of high variability/uncertainty. Results presented here will inform understanding of variability and

  8. GASP: A computer code for calculating the thermodynamic and transport properties for ten fluids: Parahydrogen, helium, neon, methane, nitrogen, carbon monoxide, oxygen, fluorine, argon, and carbon dioxide. [enthalpy, entropy, thermal conductivity, and specific heat

    Science.gov (United States)

    Hendricks, R. C.; Baron, A. K.; Peller, I. C.

    1975-01-01

    A FORTRAN IV subprogram called GASP is discussed which calculates the thermodynamic and transport properties for 10 pure fluids: parahydrogen, helium, neon, methane, nitrogen, carbon monoxide, oxygen, fluorine, argon, and carbon dioxide. The pressure range is generally from 0.1 to 400 atmospheres (to 100 atm for helium and to 1000 atm for hydrogen). The temperature ranges are from the triple point to 300 K for neon; to 500 K for carbon monoxide, oxygen, and fluorine; to 600 K for methane and nitrogen; to 1000 K for argon and carbon dioxide; to 2000 K for hydrogen; and from 6 to 500 K for helium. GASP accepts any two of pressure, temperature and density as input conditions along with pressure, and either entropy or enthalpy. The properties available in any combination as output include temperature, density, pressure, entropy, enthalpy, specific heats, sonic velocity, viscosity, thermal conductivity, and surface tension. The subprogram design is modular so that the user can choose only those subroutines necessary to the calculations.

  9. Quality assessment of ground-based microwave measurements of chlorine monoxide, ozone, and nitrogen dioxide from the NDSC radiometer at the plateau de bure

    Energy Technology Data Exchange (ETDEWEB)

    Ricaud, P.; Noe, J. de la [Observatoire Aquitain des Sciences de l' Univers (OASU), Lab. d' Astrodynamique, d' Astrophysique et d' Aeronomie de Bordeaux, Floirac (France); Baron, P. [Noveltis, Toulouse (France)

    2004-07-01

    A ground-based microwave radiometer dedicated to chlorine monoxide (ClO) measurements around 278 GHz has been in operation from December 1993-June 1996 at the Plateau de Bure, France (45 N, 5.9 E, 2500 m altitude). It belongs to the international network for the detection of stratospheric change. A detailed study of both measurements and retrieval schemes has been undertaken. Although dedicated to the measurements of ClO, simultaneous profiles of O{sub 3}, ClO and NO{sub 2}, together with information about the instrumental baseline, have been retrieved using the optimal estimation method. The vertical profiles have been compared with other ground-based microwave data, satellite-borne data and model results. Data quality shows: 1) the weak sensitivity of the instrument that obliges to make time averages over several hours; 2) the site location where measurements of good opacities are possible for only a few days per year; 3) the baseline undulation affecting all the spectra, an issue common to all the microwave instruments; 4) the slow drift of some components affecting frequencies by 3-4 MHz within a couple of months. Nevertheless, when temporally averaging data over a few days, ClO temporal variations (diurnal and over several weeks in winter 1995) from 35-50 km are consistent with model results and satellite data, particularly at the peak altitude around 40 km, although temporal coincidences are infrequent in winter 1995. In addition to ClO, it is possible to obtain O{sub 3} information from 30-60 km whilst the instrument is not optimized at all for this molecule. Retrievals of O{sub 3} are reasonable when compared with model and another ground-based data set, although the lowermost layers are affected by the contamination of baseline remnants. Monthly-averaged diurnal variations of NO{sub 2} are detected at 40 km and appear in agreement with photochemical model results and satellite zonally-averaged data, although the amplitude is weaker than the other data sets

  10. Quality assessment of ground-based microwave measurements of chlorine monoxide, ozone, and nitrogen dioxide from the NDSC radiometer at the Plateau de Bure

    Directory of Open Access Journals (Sweden)

    P. Ricaud

    2004-06-01

    Full Text Available A ground-based microwave radiometer dedicated to chlorine monoxide (ClO measurements around 278GHz has been in operation from December 1993-June 1996 at the Plateau de Bure, France (45° N, 5.9° E, 2500m altitude. It belongs to the international Network for the Detection of Stratospheric Change. A detailed study of both measurements and retrieval schemes has been undertaken. Although dedicated to the measurements of ClO, simultaneous profiles of O3, ClO and NO2, together with information about the instrumental baseline, have been retrieved using the optimal estimation method. The vertical profiles have been compared with other ground-based microwave data, satellite-borne data and model results. Data quality shows: 1 the weak sensitivity of the instrument that obliges to make time averages over several hours; 2 the site location where measurements of good opacities are possible for only a few days per year; 3 the baseline undulation affecting all the spectra, an issue common to all the microwave instruments; 4 the slow drift of some components affecting frequencies by 3-4MHz within a couple of months. Nevertheless, when temporally averaging data over a few days, ClO temporal variations (diurnal and over several weeks in winter 1995 from 35-50km are consistent with model results and satellite data, particularly at the peak altitude around 40km, although temporal coincidences are infrequent in winter 1995. In addition to ClO, it is possible to obtain O3 information from 30-60km whilst the instrument is not optimized at all for this molecule. Retrievals of O3 are reasonable when compared with model and another ground-based data set, although the lowermost layers are affected by the contamination of baseline remnants. Monthly-averaged diurnal variations of NO2 are detected at 40km and appear in agreement with photochemical model results and satellite zonally-averaged data, although the amplitude

  11. Formation of orthorhombic tin dioxide from mechanically milled monoxide powders

    Science.gov (United States)

    Lamelas, F. J.

    2004-12-01

    X-ray scattering measurements are used to show that the metastable orthorhombic phase of tin dioxide is produced by the oxidation of mechanically milled litharge-phase tin monoxide. After milling to a grain size of approximately 20nm, followed by heating to 575°C, the fraction of the orthorhombic phase is approximately 80%. The orthorhombic phase was originally observed in high-pressure experiments, but more recently, it has been produced in a wide variety of thin-film and nanoparticle samples. The data presented here demonstrate the importance of small-grain-size tin monoxide as a precursor in the ambient-pressure synthesis of the orthorhombic phase. This result has practical importance in the production of tin dioxide gas sensors. A more fundamental observation is that the particle size of a precursor phase can have a marked effect on subsequent phases produced during oxidation. Lastly, a formula for determining the orthorhombic fraction in two-phase tin dioxide samples is developed using the method of standard additions.

  12. Hypervalence in monoxides and dioxides of superalkali clusters

    Science.gov (United States)

    Cochran, Elizabeth; Meloni, Giovanni

    2014-05-01

    F2Li3, a superalkali cluster, is characterized as having a lower adiabatic ionization energy than its elemental alkali counterpart and, coupled with the presence of complex molecular orbitals, suggests promise for novel bonding possibilities. CBS-QB3 composite method was used to study three distinct cluster isomers, as well as their cationic (+1) and anionic (-1) species, to identify energetic trends and observe geometric changes. Oxides were then generated from these clusters, of which three distinct monoxides and nine dioxides were obtained upon structure optimization. Identical calculations were performed for the oxide species and their charged counterparts. Some of the most stable oxides produced appear to possess hypervalent lithium and oxygen atoms, forming unique structures with exceptional stability.

  13. Carbon Dioxide in Exoplanetary Atmospheres: Rarely Dominant Compared to Carbon Monoxide and Water

    CERN Document Server

    Heng, Kevin

    2015-01-01

    We present a comprehensive study of the abundance of carbon dioxide in exoplanetary atmospheres. We construct analytical models of systems in chemical equilibrium that include carbon monoxide, carbon dioxide, water, methane and acetylene and relate the equilibrium constants of the chemical reactions to temperature and pressure via the tabulated Gibbs free energies. We prove that such chemical systems may be described by a quintic equation for the mixing ratio of methane. By examining the abundances of these molecules across a broad range of temperatures (spanning equilibrium temperatures from 600 to 2500 K), pressures (via temperature-pressure profiles that explore albedo and opacity variations) and carbon-to-oxygen ratios (from 0.1 to 100), we conclude that carbon dioxide is subdominant compared to carbon monoxide and water. Atmospheric mixing does not alter this conclusion if carbon dioxide is subdominant everywhere in the atmosphere. Carbon dioxide and carbon monoxide may attain comparable abundances if th...

  14. Method of removing nitrogen monoxide from a nitrogen monoxide-containing gas using a water-soluble iron ion-dithiocarbamate, xanthate or thioxanthate

    Science.gov (United States)

    Liu, D. Kwok-Keung; Chang, Shih-Ger

    1987-08-25

    The present invention relates to a method of removing of nitrogen monoxide from a nitrogen monoxide-containing gas which method comprises contacting a nitrogen oxide-containing gas with an aqueous solution of water soluble organic compound-iron ion chelate complex. The NO absorption efficiency of ferrous urea-dithiocarbamate and ferrous diethanolamine-xanthate as a function of time, oxygen content and solution ph is presented. 3 figs., 1 tab.

  15. Exposure assessment for nitrogen oxides and carbon monoxide in German hard coal mining.

    Science.gov (United States)

    Dahmann, Dirk; Morfeld, Peter; Monz, Christian; Noll, Birgit; Gast, Frank

    2009-11-01

    The exposure situation of German hard coal miners with respect to the components nitrogen monoxide and nitrogen dioxide. Carbon monoxide was measured additionally and the results are displayed but not discussed in detail in this paper. The data were used to estimate personal long-term exposures in an inception cohort. For all three components, time weighted 8-h shift values were determined for typical groups of coalminers according to the European measurement standard. An expert panel from the coal mining company made an effort to estimate major potential changes in the exposure situation. The main sources of nitrogen oxides and carbon monoxide in hard coal mining were the diesel engines. Blasting fumes contributed only to a lesser degree and with different exposure characteristics, e.g. much reduced NO(2) levels compared to the mines' rear areas. As rough 8 h-shift averages describing the current exposure situation, we found 1.35 ppm NO and 0.21 ppm NO(2) for the diesel engine drivers. Blasting specialists were more difficult to evaluate but rough 8 h-shift averages of 0.84 ppm NO and 0.014 ppm NO(2) could be estimated from our measurement series. By applying these data and the estimates of experts about the retrospective exposure situation to a cohort of 1,369 coalminers, we derived mean (max) cumulative exposures in ppm x number of shifts of 1,748 (5,928) for NO and 19.6 (1,013) for NO(2) when summarizing over the follow-up period from 1974 until 1998. Especially for the diesel engine drivers, exposure can be regarded as rather high, in particular, when compared to recommended limits by SCOEL and MAK, though the exposures have been in line with the enforced German occupational exposure limits. Whether this exposure situation has caused adverse health effects will be investigated epidemiologically.

  16. Selected constituents in the smokes of foreign commercial cigaretts: tar, nicotine, carbon monoxide, and carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, R.A.; Quincy, R.B.; Guerin, M.R.

    1979-05-01

    The tar, nicotine, carbon monoxide, and carbon dioxide contents of the smokes of 220 brands of foreign commercial cigarettes are reported. In some instances, filter cigarettes of certain brands were found to deliver as much or more smoke constituents than their nonfilter counterparts. Also, data indicated that there can be a great variation in the tar, nicotine, or carbon monoxide content of the smoke of samples of a given brand of cigarettes, depending on the nation in which they are purchased. 24 tables.

  17. Adsorption of nitrogen and carbon monoxide on clinoptilolite: determination and prediction of pure and binary isotherms

    Energy Technology Data Exchange (ETDEWEB)

    Triebe, R.W.; Tezel, F.H. [University of Ottawa, Ottawa, ON (Canada). Department of Chemical Engineering

    1995-10-01

    The adsorption of carbon monoxide and nitrogen on clinoptilolite is studied to determine the natural zeolite`s potential for air purification. Pure and binary isotherms were determined for nitrogen and carbon monoxide on a natural Turkish clinoptilolite under near ambient conditions. Experimentally determined isotherms are compared to predictions based on various models from the literature. The Wilson form of the Vacancy Solution Theory is the only model that provides reasonable agreement with the binary isotherm. Clinoptilolite is concluded to be a promising sorbent for separation of carbon monoxide and nitrogen. 30 refs., 11 figs., 5 tabs.

  18. Reactions of Vanadocene-Carbyls with Carbon Monoxide, Xylylisocyanide and Carbon Dioxide

    NARCIS (Netherlands)

    Nieman, J.; Teuben, J.H.

    1985-01-01

    Vanadocene-allyl Cp2V(η1-C3H5) (1a) reacts with strong π-acceptor substrate ligands such as carbon monoxide, carbon dioxide and isonitriles. No reactions are observed with poorer π-acceptor substrates such as alkynes and nitriles. Reaction of 1a with CO gives Cp[η4-C5H5(C3H5)]V(CO)2, showing that

  19. Selective catalytic reduction of sulfur dioxide by carbon monoxide over iron oxide supported on activated carbon

    OpenAIRE

    2014-01-01

    The selective reduction of sulfur dioxide with carbon monoxide to elemental sulfur was studied over AC-supported transition-metal oxide catalysts. According to the study, Fe2O3/AC was the most active catalyst among the 4 AC-supported catalysts tested. By using Fe2O3/AC, the best catalyst, when the feed conditions were properly optimized (CO/SO2 molar ratio = 2:1; sulfidation temperature, 400 °C; Fe content, 20 wt%; GHSV = 7000 mL g-1 h-1), 95.43% sulfur dioxide conversion and 86.59% sulfur yi...

  20. Sublimation rates of carbon monoxide and carbon dioxide from comets at large heliocentric distances

    Science.gov (United States)

    Sekanina, Zdenek

    1992-01-01

    Using a simple model for outgassing from a small flat surface area, the sublimation rates of carbon monoxide and carbon dioxide, two species more volatile than water ice that are known to be present in comets, are calculated for a suddenly activated discrete source on the rotating nucleus. The instantaneous sublimation rate depends upon the comet's heliocentric distance and the Sun's zenith angle at the location of the source. The values are derived for the constants of CO and CO2 in an expression that yields the local rotation-averaged sublimation rate as a function of the comet's spin parameters and the source's cometocentric latitude.

  1. Electrocatalytic reduction of carbon dioxide to carbon monoxide and methane at an immobilized cobalt protoporphyrin

    Science.gov (United States)

    Shen, Jing; Kortlever, Ruud; Kas, Recep; Birdja, Yuvraj Y.; Diaz-Morales, Oscar; Kwon, Youngkook; Ledezma-Yanez, Isis; Schouten, Klaas Jan P.; Mul, Guido; Koper, Marc T. M.

    2015-01-01

    The electrochemical conversion of carbon dioxide and water into useful products is a major challenge in facilitating a closed carbon cycle. Here we report a cobalt protoporphyrin immobilized on a pyrolytic graphite electrode that reduces carbon dioxide in an aqueous acidic solution at relatively low overpotential (0.5 V), with an efficiency and selectivity comparable to the best porphyrin-based electrocatalyst in the literature. While carbon monoxide is the main reduction product, we also observe methane as by-product. The results of our detailed pH-dependent studies are explained consistently by a mechanism in which carbon dioxide is activated by the cobalt protoporphyrin through the stabilization of a radical intermediate, which acts as Brønsted base. The basic character of this intermediate explains how the carbon dioxide reduction circumvents a concerted proton–electron transfer mechanism, in contrast to hydrogen evolution. Our results and their mechanistic interpretations suggest strategies for designing improved catalysts. PMID:26324108

  2. US EPA Region 9 designated areas for nitrogen dioxide

    Data.gov (United States)

    U.S. Environmental Protection Agency — Polygon feature class of Attainment and Nonattainment Areas for Nitrogen Dioxide Nonattainment areas are geographic areas which have not met National Ambient Air...

  3. Palladium-Catalyzed Addition of Carbon Monoxide and Carbon Tetrachloride to 1-Octene in Supercritical Carbon Dioxide

    Institute of Scientific and Technical Information of China (English)

    张群健; 孙均华; 江焕峰; 欧阳小月; 程金生

    2003-01-01

    The Pd-catalyzed addition of carbon monoxide and carbon tetrachloride to 1-octene gave coadduct [alkyl 2-( 2, 2, 2-trichloroethyl)octanoate] as the major product in supercritical carbon dioxide by using pyridine as the base. It was found that the selectivity and the yield of coadduct were greatly affected by the pressure of carbon dioxide, the reaction temperature and the amounts of alcohol and base used.

  4. Conversion of carbon dioxide to carbon monoxide by pulse dielectric barrier discharge plasma

    Science.gov (United States)

    Wang, Taobo; Liu, Hongxia; Xiong, Xiang; Feng, Xinxin

    2017-01-01

    The conversion of carbon dioxide (CO2) to carbon monoxide (CO) was investigated in a non-thermal plasma dielectric barrier discharge (DBD) reactor, and the effects of different process conditions on the CO2 conversion were investigated. The results showed that the increase of input power could optimize the conversion of CO2 to CO. The CO2 conversion and CO yield were negatively correlated with the gas flow rate, but there was an optimum gas flow rate, that made the CO selectivity best. The carrier gas (N2, Ar) was conducive to the conversion of CO2, and the effect of N2 as carrier gas was better than Ar. The conversion of CO2 to CO was enhanced by addition of the catalyst (5A molecular sieve).

  5. Compositional variability of the Venusian atmosphere above the clouds: sulphur dioxide and carbon monoxide

    Science.gov (United States)

    Marcq, Emmanuel; Belyaev, Denis; Lellouch, Emmanuel; Encrenaz, Therese; Montmessin, Franck; Bertaux, Jean-Loup

    The layers of the Venusian atmosphere located at cloud top level is a complex transitional region where intense solar radiation interacts with a fairly dense gaseous medium and particulate matter - ultimately, the cloud particles themselves are a by-product of this interaction. In a stark contrast with the lowermost troposphere, spatial and temporal variations in temperature and composition are easily noticeable. In this talk we will focus on two gaseous species, carbon monoxide (CO) and sulphur dioxide (SO _{2}), whose sources and sinks are reversed: whereas carbon monoxide is produced by photo-dissociation of the main atmospheric constituent CO _{2} and oxidised below the clouds, SO _{2} is destroyed by UV solar radiation above the clouds and replenished from the lower atmosphere. Yet, these two species exhibit very different variation patterns. SO _{2} temporal variations range from very rapid (within a few hours) and large (by a relative factor exceeding 10) variations to secular phases of increases and decreases spanning decades. Its average latitudinal distribution ranges from a decrease with increasing latitude during SO _{2}-rich phases and a possible reversal during SO _{2}-poor phases. In contrast, CO does not exhibit significant secular, nor short-term variability, but clear horizontal trends have been measured, both with respect to latitude and local solar time.

  6. Conducting Polymers Functionalized with Phthalocyanine as Nitrogen Dioxide Sensors

    Directory of Open Access Journals (Sweden)

    S. D. Deshpande

    2002-05-01

    Full Text Available The conducting polymers such as polyaniline, polypyrrole and polythiophene were functionalized with copper phthalocyanine using chemical oxidation method. The obtained polymers viz. PANI-CuPc, PPy-CuPc and PT-CuPc were studied as chemical sensors by their response characteristics after exposure to various chemical vapors such as methanol, ammonia and nitrogen dioxide. The results obtained showed that these polymers have moderate sensitivity towards the methanol as well as ammonia vapors whereas they show tremendous sensitivity towards nitrogen dioxide vapors. The sensitivity factor of as high as 50,000 was obtained for PT-CuPc polymers in nitrogen dioxide. In comparison to this, the sensitivity factors of about 100 and 40 were obtained, when these polymers were exposed to ammonia and methanol vapors. The very high selectivity towards the nitrogen dioxide was explained on the basis of charge transfer complex formed between, the phthalocyanine donor and nitrogen dioxide acceptor molecules. On the other hand, ammonia becomes a competing electron donor in CuPc containing conducting polymers. The very low response towards the methanol may be explained on the basis very little charge transfer / interaction between CuPc containing polymers and methanol. Thus, CuPc incorporated conducting polymers have much higher selectivity than their original homopolymer.

  7. Nitrogen dioxide exposure and urinary excretion of hydroxyproline and desmosine.

    Science.gov (United States)

    Adgate, J L; Reid, H F; Morris, R; Helms, R W; Berg, R A; Hu, P C; Cheng, P W; Wang, O L; Muelenaer, P A; Collier, A M

    1992-01-01

    The relationship between average and peak personal exposure to nitrogen dioxide and urinary excretion of hydroxyproline and desmosine was investigated in a population of preschool children and their mothers. Weekly average personal nitrogen dioxide exposures for subjects who resided in homes with one or more potential nitrogen dioxide source (e.g., a kerosene space heater, gas stove, or tobacco smoke) ranged between 16.3 and 50.6 ppb (30.6 and 95.1 micrograms/m3) for children and between 16.9 and 44.1 ppb (12.8 and 82.9 micrograms/m3) for mothers. In these individuals, the hydroxyproline-to-creatinine and desmosine-to-creatinine ratios were unrelated to personal nitrogen dioxide exposure--even though continuous monitoring documented home nitrogen dioxide concentration peaks of 100-475 ppb lasting up to 100 h in duration. Significantly higher hydroxyproline-to-creatinine and desmosine-to-creatinine ratios were observed in children, compared with mothers (p < .001 and .003, respectively).

  8. Selected constituents in the smokes of U. S. commercial cigaretts: tar, nicotine, carbon monoxide and carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, R.A.; Quincy, R.B.; Guerin, M.R.

    1979-05-01

    One hundred twenty-one brands of United States commercial cigarettes were analyzed for their deliveries of tar, nicotine, carbon monoxide, and carbon dioxide under standard analytical smoking conditions. The sample included both filter and nonfilter cigarettes. Comparisons of carbon monoxide deliveries over the range of observed tar deliveries indicated a very high correlation between CO and tar for filter cigarettes, but nonfilter cigarettes tended to produce much less CO than would have been predicted from their tar deliveries. Comparison of ORNL nicotine values for specific brands with those determined by the Federal Trade Commission yield no statistically significant differences between laboratories. 4 figures, 6 tables.

  9. Natural clinoptilolite exchanged with iron: characterization and catalytic activity in nitrogen monoxide reduction

    Directory of Open Access Journals (Sweden)

    Daria Tito-Ferro

    2016-12-01

    Full Text Available The aim of this work was to characterize the natural clinoptilolite from Tasajeras deposit, Cuba, modified by hydrothermal ion-exchange with solutions of iron (II sulfate and iron (III nitrate in acid medium. Besides this, its catalytic activity to reduce nitrogen monoxide with carbon monoxide/propene in the presence of oxygen was evaluated. The characterization was performed by Mössbauer and UV-Vis diffuse reflectance spectroscopies and adsorption measurements. The obtained results lead to conclude that in exchanged samples, incorporated divalent and trivalent irons are found in octahedral coordination. Both irons should be mainly in cationic extra-framework positions inside clinoptilolite channels as charge compensating cations, and also as iron oxy-hydroxides resulting from limited hydrolysis of these cations. The iron (III exchanged samples has a larger amount of iron oxy-hydroxides agglomerates. The iron (II exchanged samples have additionally iron (II sulfate adsorbed. The catalytic activity in the nitrogen monoxide reduction is higher in the exchanged zeolites than starting. Among all samples, those exchanged of iron (II has the higher catalytic activity. This lead to outline that, main catalytically active centers are associated with divalent iron.

  10. Molten metal reactor and method of forming hydrogen, carbon monoxide and carbon dioxide using the molten alkaline metal reactor

    Science.gov (United States)

    Bingham, Dennis N.; Klingler, Kerry M.; Turner, Terry D.; Wilding, Bruce M.

    2012-11-13

    A molten metal reactor for converting a carbon material and steam into a gas comprising hydrogen, carbon monoxide, and carbon dioxide is disclosed. The reactor includes an interior crucible having a portion contained within an exterior crucible. The interior crucible includes an inlet and an outlet; the outlet leads to the exterior crucible and may comprise a diffuser. The exterior crucible may contain a molten alkaline metal compound. Contained between the exterior crucible and the interior crucible is at least one baffle.

  11. Gas-phase energies of actinide oxides -- an assessment of neutral and cationic monoxides and dioxides from thorium to curium

    Energy Technology Data Exchange (ETDEWEB)

    Marcalo, Joaquim; Gibson, John K.

    2009-08-10

    An assessment of the gas-phase energetics of neutral and singly and doubly charged cationic actinide monoxides and dioxides of thorium, protactinium, uranium, neptunium, plutonium, americium, and curium is presented. A consistent set of metal-oxygen bond dissociation enthalpies, ionization energies, and enthalpies of formation, including new or revised values, is proposed, mainly based on recent experimental data and on correlations with the electronic energetics of the atoms or cations and with condensed-phase thermochemistry.

  12. DFT studies on the SCR reaction mechanism of nitrogen monoxide with propylene catalyzed by copper oxide

    Institute of Scientific and Technical Information of China (English)

    TIAN Ying; XU Jing; ZHAO Jing-xiang

    2007-01-01

    The SCR reaction mechanism of NO with C3H6catalyzed by CuO was studied by the method of Density Functional Theory (DFT) at the B3LYP/LanL2DZ levels. The optimized geometries of the stationary points on the potential surface were obtained and the transition state was confirmed by IRC and vibration analysis. The activation energy was calculated being 34. 26 kJ/mol. It was shown that propylene reacted firstly with Cu forming intermediate, and then nitrogen monoxide immediately reacted with the intermediate to be reduced. It was proved to be a direct interaction mechanism.

  13. Testing of Colorimetric Tubes for Nitrogen Dioxide and Monomethylhydrazine.

    Science.gov (United States)

    Diamond, Philip

    Colorimetric tubes for nitrogen dioxide (NO2) and monomethylhydrazine (MMH) were tested for accuracy and results indicate that at the levels checked the tubes' average deviation was plus or minus 20 percent. Tube NO2 concentrations all read lower than the analyzed concentrations. MMH tubes read much higher than the analyzed concentration of 0.28…

  14. Bromine monoxide / sulphur dioxide ratios in relation to volcanological observations at Mt. Etna 2006–2009

    Directory of Open Access Journals (Sweden)

    G. Giuffrida

    2012-12-01

    Full Text Available Over a 3-yr period, from 2006 to 2009, frequent scattered sunlight DOAS measurements were conducted at Mt. Etna at a distance of around 6 km downwind from the summit craters. During the same period and in addition to these measurements, volcanic observations were made by regularly visiting various parts of Mt. Etna. Here, results from these measurements and observations are presented and their relation is discussed. The focus of the investigation is the bromine monoxide/sulphur dioxide (BrO / SO2 ratio, and its variability in relation to volcanic processes. That the halogen/sulphur ratio can serve as a precursor or indicator for the onset of eruptive activity was already proposed by earlier works (e.g. Noguchi and Kamiya 1963; Menyailov, 1975; Pennisi and Cloarec, 1998; Aiuppa et al., 2002. However, there is still a limited understanding today because of the complexity with which halogens are released, depending on magma composition and degassing conditions. Our understanding of these processes is far from complete, for example of the rate and mechanism of bubble nucleation, growth and ascent in silicate melts (Carroll and Holloway, 1994, the halogen vapour-melt partitioning and the volatile diffusivity in the melt (Aiuppa et al., 2009. With this study we aim to add one more piece to the puzzle of what halogen/sulphur ratios might tell about volcanic activities. Our data set shows an increase of the BrO / SO2 ratio several weeks prior to an eruption, followed by a decline before and during the initial phase of eruptive activities. Towards the end of activity or shortly thereafter, the ratio increases to baseline values again and remains more or less constant during quiet phases. To explain the observed evolution of the BrO / SO2 ratio, a first empirical model is proposed. This model suggests that bromine, unlike chlorine and fluorine, is less soluble in the magmatic melt than sulphur. By using the DOAS method to determine SO2, we actually

  15. Preparation and characterization of nitrogen-doped titanium dioxides

    Institute of Scientific and Technical Information of China (English)

    ZHU GuoPing; ZHOU KangGen

    2007-01-01

    A type of high visible-light active titanium oxinitride (TiO2_xNx) powder was prepared by a simple process: the calcination of the hydrated titanium dioxide at the atmosphere of ammonia-argon using a tubular electric furnace at high temperatures. The hydrated titanium dioxide was synthesized as the precursor of TiO2_xNx using titanic acid as raw material, which came from sulfate technique of producing titanium white. The effects of temperature and reaction time on the nitrogen content, grain size and crystal structure were studied. The visible-light activity and photocatalysis capability of the powder were also investigated.

  16. Distribution of Nitrogen Dioxide Concentration in Kaunas 2003–2007

    Directory of Open Access Journals (Sweden)

    Dovilė LAURINAVIČIENĖ

    2011-01-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 st1\\:*{behavior:url(#ieooui } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} The aim of the present study was to assess distribution of nitrogen dioxide concentration in Kaunas. A passive sampling method was used. Sampling was carried out in 62 measurements points of Kaunas city during four different seasons in 2003-2007. According to the measured concentration average seasonal and annual concentration of nitrogen dioxide was calculated. The study results showed that mean nitrogen dioxide concentration in Kaunas was 18.1 µgm-3. The highest mean seasonal concentration was found during spring (20.1 µgm-3, the lowest - during winter (16.5 µgm-3. The highest nitrogen dioxide concentration was in Centras district (26.3 µgm-3, the lowest in Rokai - 11.4 µgm-3. Using Arc GIS program, maps of nitrogen dioxide concentration distribution were plotted. Nitrogen dioxide concentration interpoliation results revealed that the highest pollution was in Centras, Žaliakalnis, Dainava districts, the lowest was found in the areas with lower traffic flows and more green places.

  17. Catalytic Activation of Nitrogen Dioxide for Selective Synthesis of Nitroorganics

    Science.gov (United States)

    2015-01-15

    attack of NO2– at a methyl group in the FA9550-11-1-0253: Catalytic Activation of Nitrogen Dioxide for Selective Synthesis of Nitroorganics PI: Seth...They can be installed (generally as their pinacol esters) by efficient iridium -catalyzed undirected aryl C-H activation. They can then be used to...of ipso nitro-deboronation, in reasonable yields. Trichlorotris(pyridine) iridium (III) is the most selective catalyst for this reaction. The reaction

  18. Preliminary assessment of air quality for sulphur dioxide, nitrogen dioxide, nitrogen oxides, particulate matter, and lead in the Netherlands under European legislation

    NARCIS (Netherlands)

    Breugel PB van; Buijsman E; LLO

    2001-01-01

    The current air quality in the Netherlands for sulphur dioxide, nitrogen dioxide, nitrogen oxides, particulate matter and lead has been assessed in the context of limit values, margins of tolerance and the assessment thresholds used in the first daughter directive for air quality of the European

  19. Sublimation rates of carbon monoxide and carbon dioxide from comet nuclei at large distances from the Sun

    Science.gov (United States)

    Sekanina, Zdenek

    1991-01-01

    One of the more attractive among the plausible scenarios for the major emission event recently observed on Comet Halley at a heliocentric distance of 14.3 AU is activation of a source of ejecta driven by an icy substance much more volatile than water. As prerequisite for the forthcoming detailed analysis of the imaging observations of this event, a simple model is proposed that yields the sublimation rate versus time at any location on the surface of a rotating cometary nucleus for two candidate ices: carbon monoxide and carbon dioxide. The model's variable parameters are the comet's heliocentric distance r and the Sun's instantaneous zenith angle z.

  20. Emission Ratios of the Tropospheric Ozone Precursors Nitrogen Dioxide and Formaldehyde from Australia’s Black Saturday Fires

    Directory of Open Access Journals (Sweden)

    Clare Paton-Walsh

    2011-10-01

    Full Text Available The ‘Black Saturday’ fires were a series of devastating forest fires that burned across Victoria, Australia, during February and March of 2009. In this study we have used satellite data made publically available by NASA from the Ozone Monitoring Instrument (OMI and the Atmospheric InfraRed Sounder (AIRS to track the smoke plume from the Black Saturday firestorm and explore the chemical aging of the smoke plume in the first days after emission. We also determined emission ratios for formaldehyde and nitrogen dioxide within smoke from fires actively burning across Victoria between 7 and 17 February 2009. The mean emission ratios with respect to carbon monoxide derived for these two tropospheric ozone precursors are (0.016 ± 0.004 mol.mol−1 for formaldehyde and (0.005 ± 0.002 mol.mol−1 for nitrogen dioxide. The mean emission ratio for formaldehyde with respect to CO is in broad agreement with values previously quoted in the literature for temperate forest fires. However, to our knowledge there are no previous measurements of emission ratios for nitrogen dioxide from Australian temperate forest fires.

  1. Preparation and characterization of nitrogen-doped titanium dioxides

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A type of high visible-light active titanium oxinitride(TiO2-xNx) powder was prepared by a simple proc-ess:the calcination of the hydrated titanium dioxide at the atmosphere of ammonia-argon using a tu-bular electric furnace at high temperatures. The hydrated titanium dioxide was synthesized as the precursor of TiO2-xNx using titanic acid as raw material,which came from sulfate technique of produc-ing titanium white. The effects of temperature and reaction time on the nitrogen content,grain size and crystal structure were studied. The visible-light activity and photocatalysis capability of the powder were also investigated.

  2. Determination of nitrogen monoxide in high purity nitrogen gas with an atmospheric pressure ionization mass spectrometer

    Science.gov (United States)

    Kato, K.

    1985-01-01

    An atmospheric pressure ionization mass spectrometric (API-MS) method was studied for the determination of residual NO in high purity N2 gas. The API-MS is very sensitive to NO, but the presence of O2 interferes with the NO measurement. Nitrogen gas in cylinders as sample gas was mixed with NO standard gas and/or O2 standard gas, and then introduced into the API-MS. The calibration curves of NO and O2 has linearity in the region of 0 - 2 ppm, but the slopes changed with every cylinder. The effect of O2 on NO+ peak was additive and proportional to O2 concentration in the range of 0 - 0.5 ppm. The increase in NO+ intensity due to O2 was (0.07 - 0.13)%/O2, 1 ppm. Determination of NO and O2 was carried out by the standard addition method to eliminate the influence of variation of slopes. The interference due to O2 was estimated from the product of the O2 concentration and the ratio of slope A to Slope B. Slope A is the change in the NO+ intensity with the O2 concentration. Slope B is the intensity with O2 concentration.

  3. Electrocatalytic reduction of carbon dioxide to carbon monoxide and methane at an immobilized cobalt protoporphyrin

    NARCIS (Netherlands)

    Shen, J.; Kortlever, R.; Kas, Recep; Mul, Guido; Koper, M.T.M.

    2015-01-01

    The electrochemical conversion of carbon dioxide and water into useful products is a major challenge in facilitating a closed carbon cycle. Here we report a cobalt protoporphyrin immobilized on a pyrolytic graphite electrode that reduces carbon dioxide in an aqueous acidic solution at relatively low

  4. Cryogenic Adsorption of Nitrogen and Carbon Dioxide in Activated Carbon

    Science.gov (United States)

    Shen, Fuzhi; Liu, Huiming; Xu, Dong; Zhang, Hengcheng; Lu, Junfeng; Li, Laifeng

    2017-09-01

    Activated carbon have been used for a long time at low temperature for cryogenic applications. The knowledge of adsorption characteristics of activated carbon at cryogenic temperature is essential for some specific applications. However, such experimental data are very scare in the literature. In order to measure the adsorption characteristics of activated carbon under variable cryogenic temperatures, an adsorption measurement device was presented. The experiment system is based on the commercially available PCT-pro adsorption analyzer coupled to a two-stage Gifford McMahon refrigerator, which allows the sample to be cooled to 4.2K. Cryogenic environment can be maintained steadily without the cryogenic liquid through the cryocooler and temperature can be controlled precisely between 5K and 300K by the temperature controller. Adsorption measurements were performed in activated carbon for carbon dioxide and nitrogen and the adsorption isotherm were obtained.

  5. Potential Energy Surfaces of Nitrogen Dioxide for the Ground State

    Institute of Scientific and Technical Information of China (English)

    SHAO Ju-Xiang; ZHU Zheng-He; CHENG Xin-Lu; YANG Xiang-Dong

    2007-01-01

    The potential energy function of nitrogen dioxide with the C2v symmetry in the ground state is represented using the simplified Sorbie-Murrell many-body expansion function in terms of the symmetry of NO2. Using the potential energy function, some potential energy surfaces of NO2(C2v, X2A1), such as the bond stretching contour plot for a fixed equilibrium geometry angle θ and contour for O moving around N-O (R1), in which R1 is fixed at the equilibrium bond length, are depicted. The potential energy surfaces are analysed. Moreover, the equilibrium parameters for NO2 with the C2v, Cs and D8h symmetries, such as equilibrium geometry structures and energies, are calculated by the ab initio (CBS-Q) method.

  6. Responses of Tree Seedlings to a Changing Atmosphere: Effects of Carbon Dioxide, Nitrogen Dioxide, and Ozone

    Science.gov (United States)

    Eller, A. S.; Sparks, J. P.

    2008-12-01

    Human activities have caused changes in the chemical composition of the atmosphere: the concentrations of carbon dioxide (CO2), nitrogen dioxide (NO2), and ozone (O3) have increased and are expected to continue increasing in the future. These gases have the potential to alter plant physiological processes, change growth rates, C:N, and carbon storage potential. The responses of tree seedlings to these changes will have a profound impact on the species composition and carbon storage potential of forests in the future. Others have found CO2 tends to increase plant growth and O3 to decrease it. NO2, if assimilated by plants, can be a source of nutrient nitrogen, but is also an oxidant with the potential to damage cell membranes and decrease growth. The objectives of this study were to determine the single and combined effects of CO2, NO2, and O3 on sugar maple, eastern hemlock, and two clones of trembling aspen. The trees were fumigated for two growing seasons with elevated (40ppb) or ambient NO2, elevated (560ppm) or ambient CO2, elevated (100 ppb 5 days/week) or ambient O3, and with or without additional soil nitrate (30 kg ha-1 yr-1) to simulate ecosystems with and without nitrogen limitation. We found that elevated CO2 increased total biomass of both maples and hemlocks. Further, the CO2 growth effect was most striking when combined with elevated O2; elevated CO2 eliminated the growth decrease induced by O3 especially when nitrogen was limited. Elevated NO2 had no effect on maple seedlings, but, similar to CO2, eliminated the decrease in growth under O3 on hemlock seedlings. The two aspen clones differed in their resistance to ozone. The non-resistant clone exhibited growth responses similar to maple. However, the resistant clone did not exhibit a growth response under any gas treatment regardless of soil nitrogen status. The variation in responses among species, within clones of the same species, and between fumigations was large in this study and suggests

  7. Nitrogen dioxide and respiratory illness in children. Part I: Health outcomes.

    Science.gov (United States)

    Samet, J M; Lambert, W E; Skipper, B J; Cushing, A H; Hunt, W C; Young, S A; McLaren, L C; Schwab, M; Spengler, J D

    1993-06-01

    We have carried out a prospective cohort study to test the hypothesis that exposure to nitrogen dioxide increases the incidence and severity of respiratory infections during the first 18 months of life. Between January 1988 and June 1990, 1,315 infants were enrolled into the study at birth and followed with prospective surveillance for the occurrence of respiratory infections and monitoring of nitrogen dioxide concentrations in their homes. The subjects were healthy infants from homes without smokers; they were selected with stratification by type of cooking stove at a ratio of four to one for gas and electric stoves. Illness experience was monitored by a daily diary of symptoms completed by the mother and a telephone interview conducted every two weeks. Illnesses with wheezing or wet cough were classified as involving the lower respiratory tract; all other respiratory illnesses were designated as involving the upper respiratory tract. Exposure to nitrogen dioxide was estimated by two-week average concentrations measured in the subjects' bedrooms with passive samplers. This analysis is limited to the 1,205 subjects completing at least one month of observation; of these, 823 completed the full protocol, contributing 82.8% of the total number of days during which the subjects were under observation. Incidence rates for all respiratory illnesses, all upper respiratory illness, all lower respiratory illnesses, and lower respiratory illness further divided into those with any wheezing, or wet cough without wheezing, were examined within strata of nitrogen dioxide exposure at the time of the illness, nitrogen dioxide exposure during the prior month, and type of cooking stove. Consistent trends of increasing illness incidence rates with increasing exposure to nitrogen dioxide were not evident for either the lagged or unlagged exposure variables. The effect of nitrogen dioxide exposure on illness occurrence during at-risk intervals of two weeks' duration was examined using

  8. Photochemical ozone and nitric oxide formation in air-nitrogen dioxide mixtures containing sulfur dioxide or chlorine

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, J.S.; Springer, G.S.; Stedman, D.H.

    1980-01-01

    The effects of sulfur dioxide and chlorine on ozone and nitric oxide concentrations in nitrogen dioxide-air mixtures were studied. The presence of 0-10 ppM SO/sub 2/ produced no change in the air mixture. Addition of 1-15 ppm chlorine increased the ozone concentration in the air mixture. A reaction model describing the interactions of chlorine and NO/sub 2/ is presented. (1 diagram, 6 graphs, 30 references, 3 tables)

  9. Seasonal trends of atmospheric nitrogen dioxide and sulfur dioxide over North Santa Clara, Cuba.

    Science.gov (United States)

    Alejo, Daniellys; Morales, Mayra C; de la Torre, Jorge B; Grau, Ricardo; Bencs, László; Van Grieken, René; Van Espen, Piet; Sosa, Dismey; Nuñez, Vladimir

    2013-07-01

    Atmospheric nitrogen dioxide (NO2) and sulfur dioxide (SO2) levels were monitored simultaneously by means of Radiello passive samplers at six sites of Santa Clara city, Cuba, in the cold and the warm seasons in 2010. The dissolved ionic forms of NO2 and SO2 as nitrate and sulfite plus sulfate, respectively, were determined by means of ion chromatography. Analysis of NO2 as nitrite was also performed by UV-Vis spectrophotometry. For NO2, significant t tests show good agreement between the results of IC and UV-Vis methods. The NO2 and SO2 concentrations peaked in the cold season, while their minimum levels were experienced in the warm season. The pollutant levels do not exceed the maximum allowable limit of the Cuban Standard 39:1999, i.e., 40 μg/m(3) and 50 μg/m(3) for NO2 and SO2, respectively. The lowest pollutant concentrations obtained in the warm season can be attributed to an increase in their removal via precipitation (scavenging) while to the decreased traffic density and industrial emission during the summer holidays (e.g., July and August).

  10. Nitrogen-assisted Three-phase Equilibrium in Hydrate Systems Composed of Water, Methane, Carbon Dioxide, and Nitrogen

    Science.gov (United States)

    Darnell, K.; Flemings, P. B.; DiCarlo, D. A.

    2016-12-01

    Guest molecule exchange is a new and promising methane hydrate production technique in which methane gas is produced by injection of another gas without requiring depressurization or thermal stimulation. The technique is generally associated with injection of carbon dioxide, but injection of nitrogen and carbon dioxide mixtures are the most efficient and economical. However, thermodynamic behavior of injection mixtures is poorly understood, and it is unclear how nitrogen affects the exchange process. Here, we describe thermodynamic stability of hydrate systems that contain water, methane, carbon dioxide, and nitrogen. We present a series of ternary and quaternary phase diagrams and show the impact nitrogen has on hydrate stability. Our results demonstrate that nitrogen can either stabilize hydrate, de-stabilize hydrate, or produce three-phase equilibrium (gas, water, and hydrate) depending on its relative abundance. At low abundance nitrogen forms hydrate and directly contributes to the exchange process. At high abundance nitrogen de-stabilizes hydrate akin to traditional hydrate inhibitors, such as salt, alcohol, or mono-ethylene glycol. We show how the dual properties of nitrogen lead to three-phase equilibrium and how three-phase equilibrium may explain much of the behavior observed in methane production from nitrogen-rich injections. We apply our analysis to laboratory experiments and the methane hydrate field test on the northern Alaskan slope at Ignik Sikumi. These results can be extended to analyze dynamic evolution of mixed hydrate systems.

  11. Nitrogen Dioxide NAAQS Designations, Region 9, 2009, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — Polygon feature class of Attainment and Nonattainment Areas for Nitrogen Dioxide Nonattainment areas are geographic areas which have not met National Ambient Air...

  12. HIRDLS/Aura Level 3 Nitrogen Dioxide (NO2) Zonal Fourier Coefficients V007

    Data.gov (United States)

    National Aeronautics and Space Administration — The "HIRDLS/Aura Level 3 Nitrogen Dioxide (NO2) Zonal Fourier Coefficients" version 7 data product (H3ZFCNO2) contains the entire mission (~3 years) of HIRDLS data...

  13. Photochemical reactions among formaldehyde, chlorine, and nitrogen dioxide in air

    Energy Technology Data Exchange (ETDEWEB)

    Hanst, P.L.; Gay, B.W. Jr.

    1977-11-01

    Photochemical reactions among chlorine, nitrogen dioxide, and formaldehyde were studied, using parts-per-million concentrations in 1 atm of air. The reactant mixtures were irradiated by ultraviolet fluorescent lamps and simultaneously analyzed by the Fourier transform infrared technique by use of folded light paths up to 504 m. With an excess of NO/sub 2/ over Cl/sub 2/, the reaction products included O/sub 3/, CO, HNO/sub 3/,N/sub 2/O/sub 5/, HCl, and nitryl chloride (ClNO/sub 2/). When chlorine exceeded NO/sub 2/, the principal product was peroxy nitric acid (HOONO/sub 2/). Peroxy formyl nitrate, nitrous acid, and chlorine nitrate were not seen. The nitryl chloride was stable even with the ultraviolet lights on. The peroxy nitric acid disappeared from the cell with a half-life of about 10 min. Formyl radicals (HCO), unlike acetyl radicals, did not combine with O/sub 2/ and NO/sub 2/ by addition. HCO reacted with O/sub 2/ to yield CO and HO/sub 2/. The HO/sub 2/ will then add to NO/sub 2/ to yield HOONO/sub 2/. If NO is present, the HO/sub 2/ will prefer to react with it, oxidizing it to NO/sub 2/.

  14. Catalytic reduction of nitric oxide with carbon monoxide on copper-cobalt oxides supported on nano-titanium dioxide.

    Science.gov (United States)

    Chen, Xia; Zhang, Junfeng; Huang, Yan; Tong, Zhiquan; Huang, Ming

    2009-01-01

    A series of copper-cobalt oxides supported on nano-titanium dioxide were prepared for the reduction of nitric oxide with carbon monoxide and characterized using techniques such as XRD, BET and TPR. Catalyst CuCoOx/TiO2 with Cu/Co molar ratio of 1/2, Cu-Co total loading of 30% at the calcination temperature of 350 degrees C formed CuCo2O4 spinel and had the highest activity. NO conversion reached 98.9% at 200 degrees C. Mechanism of the reduction was also investigated, N2O was mainly yielded below 100 degrees C, while N2 was produced instead at higher temperature. O2 was supposed to accelerate the reaction between NOx and CO for its oxidation of NO to give more easily reduced NO2, but the oxidation of CO by O2 to CO2 decreased the speed of the reaction greatly. Either SO2 or H2O had no adverse impact on the activity of NO reduction; however, in the presence of both SO2 and H2O, the catalyst deactivated quickly.

  15. Monitoring of nitrogen dioxide, ozone and halogens radicals in Antarctica

    Science.gov (United States)

    Bortoli, Daniele; Ravegnani, Fabrizio; Costa, Maria J.; Genco, Silvia; Kulkarni, Pavan K.; Mendes, Rui; Domingues, Ana Filipa; Anton, Manuel; Giovanelli, Giorgio; Silva, Ana Maria

    2013-10-01

    Monitoring of atmospheric compounds at high latitudes is a key factor for a better understanding of the processes driving the chemical cycles of ozone and related chemical species. In this frame, the GASCOD (Gas Analizer Spectrometer Correlating Optical Differences) equipment is installed at the Mario Zucchelli Station (MZS - 74.69S, 164.12E) since December 1995, carrying out observations of nitrogen dioxide (NO2) and ozone (O3). The recent advances in sensor technologies and processor capabilities, suggested the setup of a new equipment, based on the same optical layout of the 'old' GASCOD , with enhanced performances and improved capabilities for the measurements of solar radiation in the UV-visible spectral range (300-700nm). The efforts accomplished, allowed for the increase of the investigated tracers. Actually, mainly due to the enlargement of the covered spectral range and to the adoption of a CCD sensor, in addition to the NO2 and O3 compounds, others species can be monitored with the new instrumental setup such as bromine, chlorine and iodine oxides (BrO, OClO and IO). The innovative equipment called GASCODNG (GASCOD New Generation) was installed at MZS during the 2012/2013 Italian Antarctic expedition, in the framework of the research projects SAMOA (Automatic Station Monitoring Antarctic Ozonosphere) and MATAGRO (Monitoring Atmospheric Tracers in Antarctica with Ground Based Observations) funded by the Italian and Portuguese Antarctic programs respectively. In this paper a brief description of the new equipment is provided, highlighting the main improvements with regard to the 'old' one. Furthermore the full dataset (1996 - 2012) of NO2 total columns, obtained with the GASCOD installed at MZS, is compared with the data obtained with satellite borne equipments (GOME, SCIAMACHY, OMI and GOME2) and the main statistical parameters are analyzed and discussed in detail.

  16. Impact of tropospheric nitrogen dioxide on the regional radiation budget

    Directory of Open Access Journals (Sweden)

    A. P. Vasilkov

    2009-06-01

    Full Text Available Following the launch of several satellite ultraviolet and visible spectrometers including the Ozone Monitoring Instrument (OMI, much has been learned about the global distribution of nitrogen dioxide (NO2. NO2, which is mostly anthropogenic in origin, absorbs solar radiation at ultraviolet and visible wavelengths. We parameterized NO2 absorption for fast radiative transfer calculations. Using this parameterization with cloud, surface, and NO2 information from different sensors in the NASA A-train constellation of satellites and NO2 profiles from the Global Modeling Initiative (GMI, we compute the global distribution of net atmospheric heating due to tropospheric NO2 for January and July 2005. We assess the impact of clouds and find that because most of N02 is contained in the boundary layer in polluted regions, the cloud shielding effect can significantly reduce the net atmospheric heating due to NO2. We examine the effect of diurnal variations in NO2 emissions and chemistry on net atmospheric heating and find only a small impact of these on the daily-averaged heating. While the impact of NO2 on the global radiative forcing is small, locally it can produce instantaneous net atmospheric heating of 2–4 W/m2 in heavily polluted areas. We also examine the sensitivity of NO2 absorption to various geophysical conditions. Effects of the vertical distributions of cloud optical depth and NO2 on net atmospheric heating and downwelling radiance are simulated in detail for various scenarios including vertically-inhomogeneous convective clouds observed by CloudSat. The maximum effect of NO2 on downwelling radiance occurs when the NO2 is located in the middle part of the cloud where the optical extinction peaks.

  17. In-vehicle nitrogen dioxide concentrations in road tunnels

    Science.gov (United States)

    Martin, Ashley N.; Boulter, Paul G.; Roddis, Damon; McDonough, Liza; Patterson, Michael; Rodriguez del Barco, Marina; Mattes, Andrew; Knibbs, Luke D.

    2016-11-01

    There is a lack of knowledge regarding in-vehicle concentrations of nitrogen dioxide (NO2) during transit through road tunnels in urban environments. Furthermore, previous studies have tended to involve a single vehicle and the range of in-vehicle NO2 concentrations that vehicle occupants may be exposed to is not well defined. This study describes simultaneous measurements of in-vehicle and outside-vehicle NO2 concentrations on a route through Sydney, Australia that included several major tunnels, minor tunnels and busy surface roads. Tests were conducted on nine passenger vehicles to assess how vehicle characteristics and ventilation settings affected in-vehicle NO2 concentrations and the in-vehicle-to-outside vehicle (I/O) concentration ratio. NO2 was measured directly using a cavity attenuated phase shift (CAPS) technique that gave a high temporal and spatial resolution. In the major tunnels, transit-average in-vehicle NO2 concentrations were lower than outside-vehicle concentrations for all vehicles with cabin air recirculation either on or off. However, markedly lower I/O ratios were obtained with recirculation on (0.08-0.36), suggesting that vehicle occupants can significantly lower their exposure to NO2 in tunnels by switching recirculation on. The highest mean I/O ratios for NO2 were measured in older vehicles (0.35-0.36), which is attributed to older vehicles having higher air exchange rates. The results from this study can be used to inform the design and operation of future road tunnels and modelling of personal exposure to NO2.

  18. Effect of varying the combustion parameters on the emissions of carbon monoxide and nitrogen oxides in the exhaust gases from propane-fueled vehicles.

    Science.gov (United States)

    Roberge, B

    2000-05-01

    Propane-fueled forklifts are one source of carbon monoxide (CO) contamination of workplace air. The previous study carried out by the Quebec Occupational Health and Safety Research Institute dealt with worker exposure to CO during forklift use in buildings. It recommends that exhaust gas emissions be kept below a 1 percent concentration. However, this control has not produced a significant reduction in worker exposure to CO, when factors (ventilation, type of work tasks, and management of vehicle fleet) specific to companies are taken into account. Consequently, a reduction in CO emissions below the threshold of 0.3 percent should be considered. The experience acquired with propane-fueled ice resurfacers can be used to determine the effect of combustion parameters on exhaust gas emissions. It is known that a reduction in CO emissions from ice resurfacers resulted in the appearance of nitrogen oxides (NOx) and eventually in nitrogen dioxide (NO2) poisoning. Few publications present NOx results in relation to the CO measured in the exhaust gases of propane-fueled vehicles. The objective of this study is to define the level to which CO emissions can be reduced without increasing NOx concentrations. This real-situation study quantified the CO, NO, and NOx in the exhaust gases of a fleet of propane-fueled forklifts in relation to the mixture ratio. The results show the impact of the motor speed and mixture ratio on the CO, NO, and NO2 concentrations. They confirm an increase in NOx concentrations when CO concentrations are reduced. They also show that proper maintenance of forklifts combined with optimal adjustments can reduce CO and NOx emissions. The study proposes a compromise between CO and NOx emissions by taking into account worker health and safety as well as vehicle performance. Monitoring must be done to control air quality in work areas and worker exposure to CO and NO2. A forklift preventive maintenance program and general building ventilation are the favored

  19. Carbon Dioxide Activation by Scandium Atoms and Scandium Monoxide Molecules: Formation and Spectroscopic Characterization of ScCO3 and OCScCO3 in Solid Neon.

    Science.gov (United States)

    Zhang, Qingnan; Qu, Hui; Chen, Mohua; Zhou, Mingfei

    2016-01-28

    The reactions of carbon dioxide with scandium monoxide molecules and scandium atoms are investigated using matrix isolation infrared spectroscopy in solid neon. The species formed are identified by the effects of isotopic substitution on their infrared spectra as well as density functional calculations. The results show that the ground state ScO molecule reacts with carbon dioxide to form the carbonate complex ScCO3 spontaneously on annealing. The ground state Sc atom reacts with two carbon dioxide molecules to give the carbonate carbonyl complex OCScCO3 via the previously reported OScCO insertion intermediate on annealing. The observation of these spontaneous reactions is consistent with theoretical predictions that both the Sc + 2CO2 → OCScCO3 and ScO + CO2 → ScCO3 reactions are thermodynamically exothermic and are kinetically facile, requiring little or no activation energy.

  20. Nitrogen dioxide and respiratory illness in children. Part IV: Effects of housing and meteorologic factors on indoor nitrogen dioxide concentrations.

    Science.gov (United States)

    Spengler, J D; Schwab, M; McDermott, A; Lambert, W E; Samet, J M

    1996-12-01

    In a prospective study of infants' exposure to nitrogen dioxide (NO2)* and respiratory illness, NO2 concentrations were measured in more than 1,400 homes in Albequerque, NM, From January 1988 through June 1991 (Health Effects Institute Research Report Number 58, Parts I, II and III). This report characterizes the variability in indoor NO2 concentrations across seasons and years, and identifies factors associated with variation in concentrations between homes and across seasons. In regression analyses of winter data, NO2 levels in the infants' bedrooms were predominately determined by the presence of gas cooking ranges with continuously burning pilot lights, the presence of wall or floor furnaces, the use of the stove for space heating, and the square footage of the living space. These findings are consistent with previously published analysis of data from homes in other U.S. cities. Relatively small differences in seasonal NO2 levels were observed across years. The correlation coefficient (r) of bedroom NO2 levels obtained in the same homes was 0.66 over two winters and 0.48 over two summers. For homes that had gas cooking ranges with continuously burning pilot lights, the NO2 bedroom concentrations differed, on average, less than 5 parts per billion (ppb) across winters. These differences were hypothesized to be caused by differences in the use of indoor NO2 sources, ventilation, and ambient (outdoor) NO2 levels. We were, however, unable to demonstrate an association between year-to-year differences in seasonal indoor NO2 concentrations and reported use of cooking range, furnace, or heater, or ambient NO2 levels, or temperature.

  1. Nitrogen dioxide-induced acute lung injury in sheep.

    Science.gov (United States)

    Januszkiewicz, A J; Mayorga, M A

    1994-05-20

    Lung mechanics, hemodynamics and blood chemistries were assessed in sheep (Ovis aries) before, and up to 24 h following, a 15-20 min exposure to either air (control) or approximately 500 ppm nitrogen dioxide (NO2). Histopathologic examinations of lung tissues were performed 24 h after exposure. Nose-only and lung-only routes of exposure were compared for effects on NO2 pathogenesis. Bronchoalveolar lavage fluids from air- and NO2-exposed sheep were analyzed for biochemical and cellular signs of NO2 insult. The influence of breathing pattern on NO2 dose was also assessed. Five hundred ppm NO2 exposure of intubated sheep (lung-only exposure) was marked by a statistically significant, albeit small, blood methemoglobin increase. The exposure induced an immediate tidal volume decrease, and an increase in both breathing rate and inspired minute ventilation. Pulmonary function, indexed by lung resistance and dynamic lung compliance, progressively deteriorated after exposure. Maximal lung resistance and dynamic lung compliance changes occurred at 24 h post exposure, concomitant with arterial hypoxemia. Bronchoalveolar lavage fluid epithelial cell number and total protein were significantly increased while macrophage number was significantly decreased within the 24 h post-exposure period. Histopathologic examination of lung tissue 24 h after NO2 revealed patchy edema, mild hemorrhage and polymorphonuclear and mononuclear leukocyte infiltration. The NO2 toxicologic profile was significantly attenuated when sheep were exposed to the gas through a face mask (nose-only exposure). Respiratory pattern was not significantly altered, lung mechanics changes were minimal, hypoxemia did not occur, and pathologic evidence of exudation was not apparent in nose-only, NO2-exposed sheep. The qualitative responses of this large animal species to high-level NO2 supports the concept of size dependent species sensitivity to NO2. In addition, when inspired minute ventilation was used as a dose

  2. [Effect of low-intensity ultrasound on endothelin-1 and nitrogen monoxide in uterine tissues of SD rats following abortion].

    Science.gov (United States)

    Zhang, Yanxia; Guo, Jufang; Lin, Chuan; Lu, Lu; Li, Chengzhi

    2014-01-01

    To investigate the effect of low-intensity ultrasound on the contents of endothelin (ET-1) and nitrogen monoxide (NO) in uterine tissues of SD rats after abortion. Thirty female pregnant rats were randomly divided into treatment group and control group and received mifepristone and misoprostol to induce abortion. The rats in the treatment group were treated by low-intensity ultrasound for 30 min/day for 5 consecutive days, and those in the control group received sham treatment. The uterine tissue was then taken and homogenized for measurement of ET-1 and NO contents using enzyme-linked immunosorbent assay and chemical testing. ET-1 content in the uterine tissues was significantly higher in the treatment group than in the control group (P0.05). Low-intensity ultrasound can promote the contraction of uterine smooth muscles by increasing the level of ET-1 to modulate the homeostasis of ET-1 and NO.

  3. Spatial and temporal variability of urban fluxes of methane, carbon monoxide and carbon dioxide above London, UK

    Science.gov (United States)

    Helfter, Carole; Tremper, Anja H.; Halios, Christoforos H.; Kotthaus, Simone; Bjorkegren, Alex; Grimmond, C. Sue B.; Barlow, Janet F.; Nemitz, Eiko

    2016-08-01

    We report on more than 3 years of measurements of fluxes of methane (CH4), carbon monoxide (CO) and carbon dioxide (CO2) taken by eddy-covariance in central London, UK. Mean annual emissions of CO2 in the period 2012-2014 (39.1 ± 2.4 ktons km-2 yr-1) and CO (89 ± 16 tons km-2 yr-1) were consistent (within 1 and 5 % respectively) with values from the London Atmospheric Emissions Inventory, but measured CH4 emissions (72 ± 3 tons km-2 yr-1) were over two-fold larger than the inventory value. Seasonal variability was large for CO with a winter to summer reduction of 69 %, and monthly fluxes were strongly anti-correlated with mean air temperature. The winter increment in CO emissions was attributed mainly to vehicle cold starts and reduced fuel combustion efficiency. CO2 fluxes were 33 % higher in winter than in summer and anti-correlated with mean air temperature, albeit to a lesser extent than for CO. This was attributed to an increased demand for natural gas for heating during the winter. CH4 fluxes exhibited moderate seasonality (21 % larger in winter), and a spatially variable linear anti-correlation with air temperature. Differences in resident population within the flux footprint explained up to 90 % of the spatial variability of the annual CO2 fluxes and up to 99 % for CH4. Furthermore, we suggest that biogenic sources of CH4, such as wastewater, which is unaccounted for by the atmospheric emissions inventories, make a substantial contribution to the overall budget and that commuting dynamics in and out of central business districts could explain some of the spatial and temporal variability of CO2 and CH4 emissions. To our knowledge, this study is unique given the length of the data sets presented, especially for CO and CH4 fluxes. This study offers an independent assessment of "bottom-up" emissions inventories and demonstrates that the urban sources of CO and CO2 are well characterized in London. This is however not the case for CH4 emissions which are

  4. The Effect of Compaction on Urease Enzyme Activity, Carbon Dioxide Evaluation and Nitrogen Mineralisation

    OpenAIRE

    Ayten KARACA; Abdullah BARAN; KAKTANIR, Koray

    2000-01-01

    The effects of compaction on urease enzyme activity, carbon dioxide evaluation and nitrogen mineralisation of urea-treated and untreated soils were investigated. Soils were compacted at compaction levels of O kgcm -2 , 2 kgcm -2 and 4 kgcm -2 and incubated for 28 days. The changes in urease enzyme activity, CO 2 evaluation and nitrogen mineralization were determined during incubation periods. Urease enzyme activity was decreased significantly (P

  5. Phase Equilibria of Three Binary Mixtures: Methanethiol + Methane, Methanethiol + Nitrogen, and Methanethiol + Carbon Dioxide

    DEFF Research Database (Denmark)

    Awan, Javeed; Tsivintzelis, Ioannis; Coquelet, Christophe;

    2012-01-01

    New vapor–liquid equilibrium (VLE) data for methanethiol (MM) + methane (CH4), methanethiol (MM) + nitrogen (N2), and methanethiol (MM) + carbon dioxide (CO2) is reported for temperatures of (304, 334, and 364) K in the pressure range (1 to 8) MPa. A “static–analytic” method was used for performi...

  6. Ozone and nitrogen dioxide. A study on mechanisms of toxic action and cellular defense.

    NARCIS (Netherlands)

    Rietjens, I.M.C.M.

    1986-01-01

    Ozone and nitrogen dioxide are major toxic components of photochemical smog. They arise from the combustion of fossil fuels (traffic, industrial processes) and from solar radiation-catalyzed reactions in polluted atmospheres.The morphological, physiological and biochemical effects of ozone and nitro

  7. The Cabauw Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI): Design, execution, and early results

    NARCIS (Netherlands)

    Piters, A.J.M.; Boersma, K.F.; Kroon, M.; Hains, J.C.; Roozendael, M. van; Wittrock, F.; Abuhassan, N.; Adams, C.; Akrami, M.; Allaart, M.A.F.; Apituley, A.; Beirle, S.; Bergwerff, J.B.; Berkhout, A.J.C.; Brunner, D.; Cede, A.; Chong, J.; Clémer, K.; Fayt, C.; Frieß, U.; Gast, L.F.L.; Gil-Ojeda, M.; Goutail, F.; Graves, R.; Griesfeller, A.; Großmann, K.; Hemerijckx, G.; Hendrick, F.; Henzing, B.; Herman, J.; Hermans, C.; Hoexum, M.; Hoff, G.R. van der; Irie, H.; Johnston, P.V.; Kanaya, Y.; Kim, Y.J.; Klein Baltink, H.; Kreher, K.; Leeuw, G. de; Leigh, R.; Merlaud, A.; Moerman, M.M.; Monks, P.S.; Mount, G.H.; Navarro-Comas, M.; Oetjen, H.; Pazmino, A.; Perez-Camacho, M.; Peters, E.; Du Piesanie, A.; Pinardi, G.; Puentedura, O.; Richter, A.; Roscoe, H.K.; Schönhardt, A.; Schwarzenbach, B.; Shaiganfar, R.; Sluis, W.; Spinei, E.; Stolk, A.P.; Strong, K.; Swart, D.P.J.; Takashima, H.; Vlemmix, T.; Vrekoussis, M.; Wagner, T.; Whyte, C.; Wilson, K.M.; Yela, M.; Yilmaz, S.; Zieger, P.; Zhou, Y.

    2012-01-01

    From June to July 2009 more than thirty different in-situ and remote sensing instruments from all over the world participated in the Cabauw Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI). The campaign took place at KNMI's Cabauw Experimental Site for Atmospheric Research

  8. The Cabauw Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI): design, execution, and early results

    NARCIS (Netherlands)

    Henzing, J.S.; Leeuw, G. de; Piters, A.J.M.; Boersma, K.F.; Kroon, M.; Hains, J.C.; Roozendael, M. van; Wittrock, F.; Abuhassan, N.; Adams, C.; Akrami, M.; Allaart, M.A.F.; Apituley, A.; Bergwerff, J.B.; Berkhout, A.J.C.; Brunner, D.; Cede, A.; Chong, J.; Clémer, K.; Fayt, C.; Friess, U.; Gast, L.F.L.; Gil-Ojeda, M.; Goutail, F.; Graves, R.; Griesfeller, A.; Grossmann, K.; Hemerijckx, G.; Hendrick, F.; Herman, J.; Hermans, C.; Hoexum, M.; Hoff, G.R. van der; Irie, H.; Johnston, P.V.; Kanaya, Y.; Kim, Y.J.; Klein Baltink, H.; Kreher, K.; Leigh, R.; Merlaud, A.; Moerman, M.M.; Monks, P.S.; Mount, G.H.; Navarro-Comas, M.; Oetjen, H.; Pazmino, A.; Perez-Camacho, M.; Peters, E.; Piesanie, A. du; Pinardi, G.; Puentadura, O.; Richter, A.; Roscoe, H.K.; Schönhardt, A.; Schwarzenbach, B.; Shaiganfar, R.; Sluis, W.; Spinei, E.; Stolk, A.P.; Strong, K.; Swart, D.P.J.; Takashima, H.; Vlemmix, T.; Vrekoussis, M.; Wagner, T.; Whyte, C.; Wilson, K.M.; Yela, M.; Yilmaz, S.; Zieger, P.; Zhou, Y.

    2011-01-01

    From June to July 2009 more than thirty different in-situ and remote sensing instruments from all over the world participated in the Cabauw Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI). The campaign took place at KNMI’s 5 Cabauw Experimental Site for Atmospheric Resear

  9. Concentrations of Carbon Monoxide and Nitrogen Oxides From a 25 kW Boiler Supplied Periodically and Continuously with Wood Pellets

    Directory of Open Access Journals (Sweden)

    Juszczak Marek

    2014-06-01

    Full Text Available The impact of the fuel feeding mode (continuous or periodic with different stand-by/operation time ratios on carbon monoxide (CO and nitrogen oxides (NO, NOx concentration values in the flue gas was analysed for coniferous wood pellet firing. Experiments were performed in a 25 kW water boiler equipped with an over-fed wood pellet furnace located in a full scale heat station simulating real-life conditions. Influence of oxygen concentration and temperature in the combustion chamber on carbon monoxide and nitrogen oxide concentrations was presented in diagrams. Dust and hydrocarbon concentrations were also monitored. It was concluded that the commonly used periodic fuel supply does not necessarily cause a significant increase of carbon monoxide concentration, as compared to the continuous fuel feeding mode. Continuous fuel supply can even induce higher carbon monoxide concentrations when fuel mass stream is not chosen properly. Each time new fuel type is used in a specific furnace, one should perform experiments to determine the adequate settings (stand-by/operation time ratio, fuel mass streams, air stream to obtain the optimal, lowest possible emission for a certain boiler heat output

  10. A model based on equations of kinetics to study nitrogen dioxide behavior within a plasma discharge reactor.

    Science.gov (United States)

    Abedi-Varaki, Mehdi; Ganjovi, Alireza; Shojaei, Fahimeh; Hassani, Zahra

    2015-01-01

    In this work, a zero-dimensional kinetics model is used to study the temporal behavior of different species such as charged particles, radicals and excited states inside a Dielectric Barrier Discharge plasma reactor. It is shown that, the reactor significantly reduces the concentration of nitrogen monoxide as an environmental pollutant. After a drastic increase, a decrease in the concentration of the NO2 molecules inside the reactor is seen. Nitrogen monoxide molecules with a very low concentration are produced inside the reactor and its quick conversion to other products is proved. The obtained results are compared with the existing experimental and simulation findings, whenever possible.

  11. Revealing the Origin of Activity in Nitrogen-Doped Nanocarbons towards Electrocatalytic Reduction of Carbon Dioxide

    DEFF Research Database (Denmark)

    Xu, Junyuan; Kan, Yuhe; Huang, Rui;

    2016-01-01

    Carbon nanotubes (CNTs) are functionalized with nitrogen atoms for reduction of carbon dioxide (CO2). The investigation explores the origin of the catalyst’s activity and the role of nitrogen chemical states therein. The catalysts show excellent performances, with about 90% current efficiency...... for CO formation and stability over 60 hours. The Tafel analyses and density functional theory calculations suggest that the reduction of CO2 proceeds through an initial rate-determining transfer of one electron to CO2, which leads to the formation of carbon dioxide radical anion (CO2C). The initial...... reduction barrier is too high on pristine CNTs, resulting in a very high overpotentials at which the hydrogen evolution reaction dominates over CO2 reduction.The doped nitrogen atoms stabilize the radical anion,thereby lowering the initial reduction barrier and improving the intrinsic activity. The most...

  12. CRYOCHEM calculation: Minor components influence solid solutions in nitrogen-methane atmospheres - ethane on Titan and carbon monoxide on Pluto

    Science.gov (United States)

    Tan, S. P.; Kargel, J. S.; Adidharma, H.; Marion, G. M.

    2016-12-01

    In the extremely cold conditions on Triton, Pluto and other Kuiper Belt Objects, and Titan's tropopause and lower stratosphere, the atmospheres as a whole, not components individually, are subject to freeze into solid phases as solutions, notpure ices. This is in contrast to water ice in Earth's atmosphere, where the atmosphere stays in gaseous phase when water freezes into a solid phase of presumably pure water due to the much higher temperatures involved. A molecular-based thermodynamic model for cryogenic chemical systems, referred to as CRYOCHEM, has been developed to include the phase equilibria involving multi-component solid solutions. Calculations using CRYOCHEM, therefore, can provide us with compositions of solid solutions that are in equilibrium with the gaseous atmosphere. There is no longer a need to assume pure solids conventionally used in modeling, or even as binary (two-component) mixtures, which commonly consider only nitrogen and methane. Two examples will be discussed: (1) on Titan where ethane plays a significant role in precipitation of high-altitude solid aerosols; and (2) on Pluto where carbon monoxide may also play some important role in the sublimation/condensation cycle at the surface and shallow subsurface, e.g., zone of solid-state greenhouse heating. The presence of these third components essentially affects the solid-gas phase equilibria of nitrogen-methane binary system at their respective conditions on Titan and Pluto, the information of which is useful for future modeling, including those on other bodies in the outer Solar System and comets that share similar volatiles.

  13. Biofilm Removal Using Carbon Dioxide Aerosols without Nitrogen Purge.

    Science.gov (United States)

    Hong, Seongkyeol; Jang, Jaesung

    2016-11-06

    Biofilms can cause serious concerns in many applications. Not only can they cause economic losses, but they can also present a public health hazard. Therefore, it is highly desirable to remove biofilms from surfaces. Many studies on CO2 aerosol cleaning have employed nitrogen purges to increase biofilm removal efficiency by reducing the moisture condensation generated during the cleaning. However, in this study, periodic jets of CO2 aerosols without nitrogen purges were used to remove Pseudomonas putida biofilms from polished stainless steel surfaces. CO2 aerosols are mixtures of solid and gaseous CO2 and are generated when high-pressure CO2 gas is adiabatically expanded through a nozzle. These high-speed aerosols were applied to a biofilm that had been grown for 24 hr. The removal efficiency ranged from 90.36% to 98.29% and was evaluated by measuring the fluorescence intensity of the biofilm as the treatment time was varied from 16 sec to 88 sec. We also performed experiments to compare the removal efficiencies with and without nitrogen purges; the measured biofilm removal efficiencies were not significantly different from each other (t-test, p > 0.55). Therefore, this technique can be used to clean various bio-contaminated surfaces within one minute.

  14. The effects of rising atmospheric carbon dioxide on shoot-root nitrogen and water signaling

    Directory of Open Access Journals (Sweden)

    Hsien Ming eEaslon

    2013-08-01

    Full Text Available Terrestrial higher plants are composed of roots and shoots, distinct organs that conduct complementary functions in dissimilar environments. For example, roots are responsible for acquiring water and nutrients such as inorganic nitrogen from the soil, yet shoots consume the majority of these resources. The success of such a relationship depends on excellent root-shoot communications. Increased net photosynthesis and decreased shoot nitrogen and water use at elevated CO2 fundamentally alter these source-sink relations. Lower than predicted productivity gains at elevated CO2 under nitrogen or water stress may indicate shoot-root signaling lacks plasticity to respond to rising atmospheric CO2 concentrations. The following presents recent research results on shoot-root nitrogen and water signaling, emphasizing the influence that rising atmospheric carbon dioxide levels are having on these source-sink interactions.

  15. Equation of state of initially liquid carbon monoxide and nitrogen mixture

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The modified liquid perturbation variational theory and the improved vdW-1f model were applied to calculating the equation of the state of liquid CO-N2 mixture with the ratio of 1:1, 4:1 and 1:4, respectively, in the shock pressure range of 9-49 GPa. It was shown that the calculated result for CO-N2 mixture with the ratio of 1:1 is well consistent with the earlier experimental data. The thermodynamics equilibrium, chemical equilibrium and phase equilibrium were all considered in detail. It was found that Hugoniot of liquid CO-N2 mixture is moderately softened in the pressure range of 20-30 GPa and 30-49 GPa for different initial proportions, and that the Hugoniot is more softened in the latter pressure range, which means that the structural phase transition occurs near 20 GPa and 30 GPa. Since the shock pro-ductions may absorb a plenty of systematic energy, the shock temperature and pressure decline compared with the case of no chemical reaction. Pressures and temperatures increase gradually with the increase in the mole fraction of nitrogen composition. The results for the 1:1 CO-N2 mixture lie in the middle of two others. Therefore, it was shown that the modified Lorentz-Berthelor rule used in the scheme is effective to study shock-compression properties of liquid CO-N2 mixture under high temperatures and high pressures.

  16. Influence of nitrogen dioxide on the thermal decomposition of ammonium nitrate

    Directory of Open Access Journals (Sweden)

    Igor L. Kovalenko

    2015-06-01

    Full Text Available In this paper results of experimental studies of ammonium nitrate thermal decomposition in an open system under normal conditions and in NO2 atmosphere are presented. It is shown that nitrogen dioxide is the initiator of ammonium nitrate self-accelerating exothermic cyclic decomposition process. The insertion of NO2 from outside under the conditions of nonisothermal experiment reduces the characteristic temperature of the beginning of self-accelerating decomposition by 50...70 °C. Using method of isothermal exposures it is proved that thermal decomposition of ammonium nitrate in nitrogen dioxide atmosphere at 210 °C is autocatalytic (zero-order reaction. It was suggested that there is possibility of increasing the sensitivity and detonation characteristics of energy condensed systems based on ammonium nitrate by the insertion of additives which provide an earlier appearance of NO2 in the system.

  17. On the role of nitrogen dioxide in the absorption of solar radiation

    Science.gov (United States)

    Solomon, S.; Portmann, R. W.; Sanders, R. W.; Daniel, J. S.; Madsen, W.; Bartram, B.; Dutton, E. G.

    1999-05-01

    Direct measurements of the absorption of downwelling visible radiation by nitrogen dioxide are presented. The data show that this gas can contribute significantly to local radiative forcing under certain conditions. The observed enhancements in nitrogen dioxide absorption are likely to be due both to pollution and to production by lightning in convective clouds. Case studies of several days of observations in Colorado reveal peak absorption of downwelling radiation by NO2 of up to 5-12%, corresponding to an estimated local radiative forcing that is likely to be in the range of 5-30 W/m2. The amount of local forcing associated with thunderstorm activity depends strongly upon the cloud optical depth and on where the NO2 resides within the clouds. These case studies suggest that NO2 can play a significant role in the absorption of radiation (including but not limited to anomalous cloud absorption) either under polluted conditions or when electrically active storms are considered.

  18. Nitrate formation from atmospheric nitrogen and oxygen photocatalysed by nano-sized titanium dioxide.

    Science.gov (United States)

    Yuan, Shi-Jie; Chen, Jie-Jie; Lin, Zhi-Qi; Li, Wen-Wei; Sheng, Guo-Ping; Yu, Han-Qing

    2013-01-01

    The concentration of nitrate in aquatic systems is rising with the development of modern industry and agriculture, causing a cascade of environmental problems. Here we describe a previously unreported nitrate formation process. Both indoor and outdoor experiments are conducted to demonstrate that nitrate may be formed from abundant atmospheric nitrogen and oxygen on nano-sized titanium dioxide surfaces under UV or sunlight irradiation. We suggest that nitric oxide is an intermediate product in this process, and elucidate its formation mechanisms using first-principles density functional theory calculations. Given the expanding use of titanium dioxide worldwide, such a titanium dioxide-mediated photocatalysis process may reveal a potentially underestimated source of nitrate in the environment, which on one hand may lead to an increasing environmental pollution concern, and on the other hand may provide an alternative, gentle and cost-effective method for nitrate production.

  19. Equation of state of initially liquid carbon monoxide and nitrogen mixture

    Institute of Scientific and Technical Information of China (English)

    YANG JinWen; SUN Dong; SUN Yue; SHI ShangChun

    2008-01-01

    Academy of Engineering Physics,Mianyang 621900,ChinaThe modified liquid perturbation variational theory and the improved vdW-1f model were applied to calculating the equation of the state of liquid CO-N2 mixture with the ratio of 1:1,4:1 and 1:4,respectively,in the shock pressure range of 9-49 Gpa.It was shown that the calculated result for CO-N2 mixture with the ratio of 1:1 is well consistent with the earlier experimental data.The thermodynamics equilibrium,chemical equilibrium and phase equilibrium were all considered in detail.It was found that Hugoniot of liquid CO-N2 mixture is moderately softened in the pressure range of 20-30 Gpa and 30-49 Gpa for different initial proportions,and that the Hugoniot is more softened in the latter pressure range,which means that the structural phase transition occurs near 20 Gpa and 30 Gpa.Since the shock pro-ductions may absorb a plenty of systematic energy,the shock temperature and pressure decline compared with the case of no chemical reaction.Pressures and temperatures increase gradually with the increase in the mole fraction of nitrogen composition.The results for the 1:1 CO-N2 mixture lie in the middle of two others.Therefore,it was shown that the modified Lorentz-Berthelor rule used in the scheme is effective to study shock-compression properties of liquid CO-N2 mixture under high temperatures and high pressures.

  20. Nitrogen-monoxide gas-sensing properties of transparent p-type copper-oxide nanorod arrays

    Energy Technology Data Exchange (ETDEWEB)

    Park, Soojeong; Kim, Hyojin; Kim, Dojin [Chungnam National University, Daejeon (Korea, Republic of)

    2015-01-15

    We report the nitrogen-monoxide (NO) gas-sensing properties of transparent p-type copper-oxide (CuO) nanorod arrays synthesized by using the hydrothermal method with a CuO nanoparticle seed layer deposited on a glass substrate via sputtering process. We synthesized polycrystalline CuO nanorods measuring 200 to 300 nm in length and 20 to 30 nm in diameter for three controlled molarity ratios of 1:1, 1:2 and 1:4 between copper nitrate trihydrate [Cu(NO{sub 2}){sub 2}·3H{sub 2}O] and hexamethylenetetramine (C{sub 6}H{sub 12}N{sub 4}). The crystal structures and morphologies of the synthesized CuO nanorod arrays were examined using grazing incidence X-ray diffraction and scanning electron microscopy. The gas-sensing measurements for NO gas in dry air indicated that the CuO nanorodarray-based gas sensors synthesized under hydrothermal condition at a molarity ratio of 1:2 showed the best gas sensing response to NO gas. These CuO nanorod-array gas sensors exhibited a highly sensitive response to NO gas, with a maximum sensitivity of about 650% for 10 ppm NO in dry air at an operating temperature of 100 .deg. C. These transparent p-type CuO nanorod-array gas sensors have shown a reversible and reliable response to NO gas over a range of operating temperatures. These results indicate certain potential use of p-type oxide semiconductor CuO nanorods as sensing materials for several types of gas sensors, including p - n junction gas sensors.

  1. The carbon-nitrogen balance of the nodule and its regulation under elevated carbon dioxide concentration.

    Science.gov (United States)

    Libault, Marc

    2014-01-01

    Legumes have developed a unique way to interact with bacteria: in addition to preventing infection from pathogenic bacteria like any other plant, legumes also developed a mutualistic symbiotic relationship with one gender of soil bacteria: rhizobium. This interaction leads to the development of a new root organ, the nodule, where the differentiated bacteria fix for the plant the atmospheric dinitrogen (atmN2). In exchange, the symbiont will benefit from a permanent source of carbon compounds, products of the photosynthesis. The substantial amounts of fixed carbon dioxide dedicated to the symbiont imposed to the plant a tight regulation of the nodulation process to balance carbon and nitrogen incomes and outcomes. Climate change including the increase of the concentration of the atmospheric carbon dioxide is going to modify the rates of plant photosynthesis, the balance between nitrogen and carbon, and, as a consequence, the regulatory mechanisms of the nodulation process. This review focuses on the regulatory mechanisms controlling carbon/nitrogen balances in the context of legume nodulation and discusses how the change in atmospheric carbon dioxide concentration could affect nodulation efficiency.

  2. High-resolution measurements from the airborne Atmospheric Nitrogen Dioxide Imager (ANDI

    Directory of Open Access Journals (Sweden)

    J. P. Lawrence

    2015-06-01

    Full Text Available Nitrogen Dioxide is both a primary pollutant with direct health effects and a key precursor of the secondary pollutant ozone. This paper reports on the development, characterisation and test flight of the Atmospheric Nitrogen Dioxide Imager (ANDI remote sensing system. The ANDI system includes an imaging (UV-vis grating spectrometer able to capture scattered sunlight spectra for the determination of tropospheric nitrogen dioxide (NO2 concentrations by way of DOAS slant column density and vertical column density measurements. Results are shown for an ANDI test flight over Leicester City in the UK. Retrieved NO2 columns at a surface resolution of 80 m x 20 m revealed hot spots in a series of locations around Leicester City, including road junctions, the train station, major car parks, areas of heavy industry, a nearby airport (East Midlands and a power station (Ratcliffe-on-Soar. In the city centre the dominant source of NO2 emissions was identified as road traffic, contributing to a background concentration as well as producing localised hot spots. Quantitative analysis revealed a significant urban increment over the city centre which increased throughout the flight.

  3. Effects of carbon dioxide enrichment and nitrogen supply on growth of boreal tree seedlings.

    Science.gov (United States)

    Brown, Kevin; Higginbotham, K. O.

    1986-12-01

    The effects of two levels of atmospheric carbon dioxide (350 microl l(-1), 750 microl l(-1)) and three levels of nitrogen (15.5 mM, 1.55 mM, 0.155 mM N) on biomass accumulation and partitioning were examined in aspen (Populus tremuloides Michx.) and white spruce (Picea glauca (Moench) Voss) seedlings grown in controlled environment rooms for 100 days after germination. Nitrogen supply had pronounced effects on biomass accumulation, height, and leaf area of both species. Root weight ratio (RWR) of white spruce was significantly increased at the lowest level of nitrogen, whereas RWR of aspen did not change much with increasing levels of nitrogen. Carbon dioxide enrichment significantly increased (1) the leaf and total biomass of spruce seedlings grown in the high-N regime, (2) the RWR of seedlings in the medium-N regime, and (3) the root biomass of seedlings in the low-N regime after 100 days. Carbon dioxide enrichment of aspen temporarily increased biomass and height in all three nitrogen regimes. Root, stem, and leaf mass, height, and leaf area of aspen were increased only at the 30-day harvest in the high-N treatment and at 50 and 60 days in the low-N treatment. Height, stem biomass, and leaf biomass of aspen seedlings were significantly increased by CO(2) enrichment after 40 days in the medium-N treatment. These effects did not persist, possibly because of the onset of mineral nutrient supply limitations with increasing plant size.

  4. Abrupt recent trend changes in atmospheric nitrogen dioxide over the Middle East

    KAUST Repository

    Lelieveld, J.

    2015-08-21

    Nitrogen oxides, released from fossil fuel use and other combustion processes, affect air quality and climate. From the mid-1990s onward, nitrogen dioxide (NO2) has been monitored from space, and since 2004 with relatively high spatial resolution by the Ozone Monitoring Instrument. Strong upward NO2 trends have been observed over South and East Asia and the Middle East, in particular over major cities. We show, however, that a combination of air quality control and political factors, including economical crisis and armed conflict, has drastically altered the emission landscape of nitrogen oxides in the Middle East. Large changes, including trend reversals, have occurred since about 2010 that could not have been predicted and therefore are at odds with emission scenarios used in projections of air pollution and climate change in the early 21st century.

  5. Effects of carbon dioxide and nitrogen on adhesive growth and expressions of E-cadherin and VEGF of human colon cancer cell CCL-228

    Institute of Scientific and Technical Information of China (English)

    Kai-Lin Cai; Guo-Bing Wang; Li-Juan Xiong

    2003-01-01

    AIM: To study the effects of carbon dioxide on the metastatic capability of cancer cells, and to compare them with that of nitrogen.METHODS: The colon cancer cell CCL-228 was treated with 100 % carbon dioxide or nitrogen at different time points and then cultured under normal condition. Twelve hours after the treatment, the survival rates of suspension cells and the expressions of e-cadherin and VEGF were examined.RESULTS: After 60 min of carbon dioxide and longer time of nitrogen treatment, the suspended cells increased and the expression of e-cadherin decreased while the expression of VEGF was enhanced significantly. And the effects of nitrogen were similar to, but weaker than, those of carbon dioxide.CONCLUSION: Carbon dioxide may improve the metastatic capability of cancer cells and its effects are significantly stronger than that of nitrogen. A sequential use of carbon dioxide and nitrogen in pneumoperitoneum may take the advantage of both gases.

  6. Carbon dioxide level and form of soil nitrogen regulate assimilation of atmospheric ammonia in young trees.

    Science.gov (United States)

    Silva, Lucas C R; Salamanca-Jimenez, Alveiro; Doane, Timothy A; Horwath, William R

    2015-08-21

    The influence of carbon dioxide (CO2) and soil fertility on the physiological performance of plants has been extensively studied, but their combined effect is notoriously difficult to predict. Using Coffea arabica as a model tree species, we observed an additive effect on growth, by which aboveground productivity was highest under elevated CO2 and ammonium fertilization, while nitrate fertilization favored greater belowground biomass allocation regardless of CO2 concentration. A pulse of labelled gases ((13)CO2 and (15)NH3) was administered to these trees as a means to determine the legacy effect of CO2 level and soil nitrogen form on foliar gas uptake and translocation. Surprisingly, trees with the largest aboveground biomass assimilated significantly less NH3 than the smaller trees. This was partly explained by declines in stomatal conductance in plants grown under elevated CO2. However, unlike the (13)CO2 pulse, assimilation and transport of the (15)NH3 pulse to shoots and roots varied as a function of interactions between stomatal conductance and direct plant response to the form of soil nitrogen, observed as differences in tissue nitrogen content and biomass allocation. Nitrogen form is therefore an intrinsic component of physiological responses to atmospheric change, including assimilation of gaseous nitrogen as influenced by plant growth history.

  7. Ambient nitrogen dioxide and sulfur dioxide concentrations over a region of natural gas production, Northeastern British Columbia, Canada

    Science.gov (United States)

    Islam, S. M. Nazrul; Jackson, Peter L.; Aherne, Julian

    2016-10-01

    The Peace River district of Northeastern British Columbia, Canada is a region of natural gas production that has undergone rapid expansion since 2005. In order to assess air quality implications, Willems badge passive diffusive samplers were deployed for six two-week exposure periods between August and November 2013, at 24 sites across the region to assess the ambient concentration of nitrogen dioxide (NO2) and sulfur dioxide (SO2). The highest concentrations of both species (NO2: 9.1 ppb, SO2: 1.91 ppb) during the whole study period (except the 1st exposure period), were observed in Taylor (Site 14), which is consistent with its location near major industrial sources. Emissions from industrial activities, and their interaction with meteorology and topography, result in variations in atmospheric dispersion that can increase air pollution concentrations in Taylor. However, relatively high concentrations of NO2 were also observed near the center of Chetwynd (site F20), indicating the importance of urban emissions sources in the region as well. Observations of both species from the other study sites document the spatial variability and show relatively high concentrations near Fort St. John and Dawson Creek, where unconventional oil and gas development activities are quite high. Although a few sites in Northeastern British Columbia recorded elevated concentrations of NO2 and SO2 during this investigation, the concentrations over the three-month period were well below provincial annual ambient air quality objectives. Nonetheless, given the limited observations in the region, and the accelerated importance of unconventional oil and gas extraction in meeting energy demands, it is imperative that monitoring networks are established to further assess the potential for elevated ambient concentrations associated with industrial emissions sources in the Peace River region.

  8. Analysis of nanowire transistor based nitrogen dioxide gas sensor – A simulation study

    Directory of Open Access Journals (Sweden)

    Gaurav Saxena

    2015-06-01

    Full Text Available Sensors sensitivity, selectivity and stability has always been a prime design concern for gas sensors designers. Modeling and simulation of gas sensors aids the designers in improving their performance. In this paper, different routes for the modeling and simulation of a semiconducting gas sensor is presented. Subsequently, by employing one of the route, the response of Zinc Oxide nanowire transistor towards nitrogen dioxide ambient is simulated. In addition to the sensing mechanism, simulation study of gas species desorption by applying a recovery voltage is also presented.

  9. A Passive Sampler for Determination of Nitrogen Dioxide in Ambient Air

    Science.gov (United States)

    Xiao, Dan; Lin, Lianzhi; Yuan, Hongyan; Choi, Martin M. F.; Chan, Winghong

    2005-08-01

    This article describes the use of a passive sampler for detecting and collecting nitrogen dioxide, NO 2 , in ambient air. This device is based on microporous PTFE membranes that allow air samples to diffuse through and subsequently react with an absorbing reagent solution. The absorbance value of this reagent is proportional to the NO 2 concentration in ambient air. It has been successfully applied to determine the NO 2 concentrations in various sampling sites. The sampler is simple, lightweight, and inexpensive. The experiments are suitable for college students in analytical chemistry and environmental studies.

  10. Optical-optical double-resonant multiphoton ionization spectra of Rydberg states of nitrogen dioxide

    Institute of Scientific and Technical Information of China (English)

    Zhang Gui-Yin; Zhang Lian-Shui; Sun Bo; Han Xiao-Feng; Yu Wei

    2005-01-01

    The optical-optical double-resonant multiphoton ionization(OODR-MPI) technique has been applied to the study of the Rydberg states of nitrogen dioxide. The results show that ,althougy the OODR-MPI spectra of NO2 are composed of regular progression bands at different pump laser intensities, their ionization pathways are different.The NO2 mollecule is ionized through the (3+1+1)double-resonant process as the pump laser intensity is in a high value, or else it is through the (1+2+1)rpocess.The final resonant states in the two ionizing processes have been attributed to different Rydberg states.

  11. Nitrogen Dioxide Trend over the United States: the View from the Ground, the View from Space

    Science.gov (United States)

    Lamsal, Lok N.; Duncan, Bryan N.; Yoshida, Yasuko; Krotkov, Nickolay A.

    2014-01-01

    Emissions of nitrogen oxides (NOx) are decreasing over the US due to environmental policies and technological change. We use observations of tropospheric nitrogen dioxide (NO2) columns from the Ozone Monitoring Instrument (OMI) satellite instrument and surface NO2 in-situ measurements from the air quality system (AQS) to quantify the trends, and to establish the relationship between the trends in tropospheric column and surface concentration. Both observations show substantial downward trends from 2005 to 2013, with an average reduction of 35 percent according to OMI and 38 percent according to AQS. The annual reduction rates are largest in 2005-2009: -6.2 percent per year and -7 percent per year observed by OMI and AQS, respectively. We examine various factors affecting the estimated trend in OMI NO2 columns and in-situ NO2 observations. An improved understanding of trend offers valuable insights about effectiveness of emission reduction regulations on state and federal level.

  12. Observations of carbon dioxide, methane, and carbon monoxide at Tae-Ahn peninsula (Korea), Mount Waliguan (China), Ulaan Uul (Mongolia) and at Mauna Loa (Hawaii USA)

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Y.S. [Korea National Univ. of Education, Chongwon (Korea, Republic of); Tans, P.P.; Conway, T.J.; Dlugokencky, E.J. [Climate Monitoring and Diagnostics Lab., Bouler (United States); Novelli, P.C.; Tolier, M. [Colorado Univ. (United States). Cooperative Inst. for Research in Environmental Sciences; Wen, Y. [Chinese Academy of Meteorological Sciences, Beijing (China); Dagvadorj, D. [Mongolian Hydrometeorological Research Inst., Ulaan Batar (Mongolia)

    1995-12-31

    It has been discussed that the greenhouse gases, e.g. carbon dioxide (CO{sub 2}) methane (CH{sub 4}), enhance warming in the biosphere. Many scientists are therefore interested in monitoring the minor constituents of the atmosphere and in the carbon cycle. In cooperation with the Climate Monitoring and Diagnostics Laboratory (CMDL) of U.S. National Oceanic and Atmospheric Administration (NOAA), CO{sub 2}, CH{sub 4} and carbon monoxide (CO) at the western tip of the Tae-ahn Peninsula (TAP) in central Korea since October 1990 has been measured. Shortly thereafter, two more sites were added for the measurement of greenhouse gases in East Asia; one at Mount Waliguar Qinghai Province (QPC) in China and another at Ulaan Uul (UUM), the Gobi Desert in Mongolia. Also, trace gas data obtained at Mauna Loa (MLO) in Hawaii in the USA has been used. The Hawaiian data represent the world`s longest period of CO{sub 2} monitoring since 1958. The present monitoring is a part of the Global Air Sampling Network the WMO`s Global Atmospheric Watch. The method of collecting and measuring CO{sub 2}, CO and CH{sub 4} have been described else where. Here the four year monitoring of the trace gases at the three sites in East Asia is reported. The results are also compared with the measured values obtained at the free troposphere background site at MLO in Hawaii

  13. Use of carbon monoxide combined with carbon dioxide for modified atmosphere packaging of pre- and postrigor fresh pork sausage to improve shelf life.

    Science.gov (United States)

    Laury, Angela; Sebranek, Joseph G

    2007-04-01

    Fresh pre- and postrigor pork sausage patties were manufactured in the Iowa State University Meat Laboratory and packaged either in modified atmosphere (MAP) with 0.4% carbon monoxide (CO) and 99.6% carbon dioxide (CO2) or on foam trays overwrapped with oxygen-permeable film (OW). Packages were stored at 2 to 40C under fluorescent lights for up to 31 days. Aerobic, anaerobic, and psychrotrophic plate counts, raw and cooked color, purge, and lipid oxidation were measured during storage. Results indicated that both pork sausage products in MAP had lower aerobic and psychrotrophic counts and less lipid oxidation throughout storage (P sausage in MAP benefited more from the CO atmosphere in terms of raw color than the postrigor pork sausage in MAP. Cooked color of the prerigor pork sausage in MAP was significantly redder than cooked color of the postrigor pork sausage. Both pork sausage products in MAP were also lighter (L* value) than the OW patties for raw and cooked color. Therefore, the combination of CO and CO2 in MAP was beneficial in extending the shelf life of pre-and postrigor fresh pork sausage by reducing aerobic and psychrotrophic microbial growth and improving oxidative stability and color, compared to conventional OW packaging. However, increased purge, increased anaerobic growth, and changes in cooking behavior were also observed for the products in MAP during storage (P < 0.05).

  14. Interference of oxygen, carbon dioxide, and water vapor on the analysis for oxides of nitrogen by chemiluminescence

    Science.gov (United States)

    Maahs, H. G.

    1975-01-01

    The interference of small concentrations (less than 4 percent by volume) of oxygen, carbon dioxide, and water vapor on the analysis for oxides of nitrogen by chemiluminescence was measured. The sample gas consisted primarily of nitrogen, with less than 100 parts per million concentration of nitric oxide, and with small concentrations of oxygen, carbon dioxide, and water vapor added. Results obtained under these conditions indicate that although oxygen does not measurably affect the analysis for nitric oxide, the presence of carbon dioxide and water vapor causes the indicated nitric oxide concentration to be too low. An interference factor - defined as the percentage change in indicated nitric oxide concentration (relative to the true nitric oxide concentration) divided by the percent interfering gas present - was determined for carbon dioxide to be -0.60 + or - 0.04 and for water vapor to be -2.1 + or - 0.3.

  15. Relationship between lightning activity and tropospheric nitrogen dioxide and the estimation of lightning-produced nitrogen oxides over China

    Science.gov (United States)

    Guo, Fengxia; Ju, Xiaoyu; Bao, Min; Lu, Ganyi; Liu, Zupei; Li, Yawen; Mu, Yijun

    2017-02-01

    To better understand the relationship between lightning activity and nitrogen oxides (NO X ) in the troposphere and to estimate lightning-produced NO X (LNO X ) production in China more precisely, spatial and temporal distributions of vertical column densities of tropospheric nitrogen dioxide (NO2 VCDs) and lightning activity were analyzed using satellite measurements. The results showed that the spatial distribution of lightning activity is greater in the east than in the west of China, as with NO2 VCDs. However, the seasonal and annual variation between lightning and NO2 density show different trends in the east and west. The central Tibetan Plateau is sparsely populated without modern industry, and NO2 VCDs across the plateau are barely affected by anthropogenic sources. The plateau is an ideal area to study LNO X . By analyzing 15 years of satellite data from that region, it was found that lightning density is in strong agreement with annual, spatial and seasonal variations of NO2 VCDs, with a correlation coefficient of 0.79 from the linear fit. Combining Beirle's method and the linear fit equation, LNO X production in the Chinese interior was determined to be 0.07 (0.02-0.27) TgN yr-1 for 1997-2012, within the range of 0.016-0.384 TgN yr-1 from previous estimates.

  16. Effect of chronic exposure to nitrogen dioxide on collagen content in lung and skin of guinea pigs

    Energy Technology Data Exchange (ETDEWEB)

    Drozdz, M.; Kucharz, E.; Szyja, J.

    1977-06-01

    The influence of nitrogen dioxide on the connective tissue of guinea pigs was studied after 180 days (8 hours per day) of exposure at a concentration of 2 mg/m/sup 3/. The long-term exposure induced a decrease of total collagen content in lung tissue, and an increase in skin as well as an increase of collagen catabolite levels in blood serum and urine. The increase of soluble fractions of collagen and the decrease of insoluble ones was found in skin of the exposed animals. Morphological studies showed nitrogen dioxide-induced emphysema and damage in bronchioli of the lungs and some degenerative skin changes. The results obtained suggest the inhibition of collagen maturation and/or activation of its catabolism as the main mechanism of nitrogen dioxide-induced connective tissue damage.

  17. Improved retrieval of nitrogen dioxide (NO2 column densities by means of MKIV Brewer spectrophotometers

    Directory of Open Access Journals (Sweden)

    H. Diémoz

    2014-11-01

    Full Text Available A new algorithm to retrieve nitrogen dioxide (NO2 column densities using MKIV ("Mark IV" Brewer spectrophotometers is described. The method includes several improvements, such as a more recent spectroscopic data set, the reduction of measurement noise, interference by other atmospheric species and instrumental settings, and a better determination of the zenith sky air mass factor. The technique was tested during an ad hoc calibration campaign at the high-altitude site of Izaña (Tenerife, Spain and the results of the direct sun and zenith sky geometries were compared to those obtained by two reference instruments from the Network for the Detection of Atmospheric Composition Change (NDACC: a Fourier Transform Infrared Radiometer (FTIR and an advanced visible spectrograph (RASAS-II based on the differential optical absorption spectrometry (DOAS technique. To determine the extraterrestrial constant, an easily implementable extension of the standard Langley technique for very clean sites without tropospheric NO2 was developed which takes into account the daytime linear drift of stratospheric nitrogen dioxide due to photochemistry. The measurement uncertainty was thoroughly determined by using a Monte Carlo technique. Poisson noise and wavelength misalignments were found to be the most influential contributors to the overall uncertainty, and possible solutions are proposed for future improvements. The new algorithm is backward-compatible, thus allowing for the reprocessing of historical data sets.

  18. Improved retrieval of nitrogen dioxide (NO2 column densities by means of MKIV Brewer spectrophotometers

    Directory of Open Access Journals (Sweden)

    H. Diémoz

    2014-07-01

    Full Text Available A new algorithm to retrieve nitrogen dioxide (NO2 column densities using MKIV Brewer spectrophotometers is described. The method includes several improvements, such as a more recent spectroscopic dataset, the reduction of the measurement noise and interferences by other atmospheric species and instrumental settings, and a better determination of the air mass enhancement factors. The technique was tested during an ad-hoc calibration campaign at the high-altitude site of Izaña (Tenerife, Spain and provided results compatible to those obtained from a spectrometer associated to the Network for the Detection of Atmospheric Composition Change (NDACC, with deviations of less than 0.02 DU. To determine the extraterrestrial constant, an easily implementable generalisation of the standard Langley technique was developed which takes into account the daytime linear drift of nitrogen dioxide due to the photochemistry. Estimates obtained from different observation geometries, by collecting the light from either the sun or the zenith sky, were found to be comparable within the measurement uncertainty. The latter was thoroughly determined by using a Monte Carlo technique. Finally, a method to retrieve additional products such as the degree of linear polarisation of the zenith sky and the oxygen dimer optical depth is presented. The new algorithm is backward-compatible, thus allowing for the reprocessing of historical datasets.

  19. Ozone Abundance in a Nitrogen-Carbon Dioxide Dominated Terrestrial Paleoatmosphere

    CERN Document Server

    Thomas, B C; Martin, L D; Jackman, C H

    2004-01-01

    We compute the ozone distribution for a model terrestrial paleoatmosphere in which the present oxygen abundance is largely replaced by carbon dioxide, which we argue is a reasonable working assumption. In principle, the presence of carbon dioxide might supplement the ozone shield as compared with models based on nitrogen without high carbon dioxide abundance so that early life need not have been as UV-resistant as often assumed. An extrasolar planet with a high-CO2 atmosphere might contain enough O3 to be a source of false positive biomarkers. We find that the globally averaged O3 column density can be the same, or nearly four times higher (depending upon the O2 partial pressure) when CO2 is used in place of N2 as the replacement component for lowered O2 in a 1-atm terrestrial planet with solar radiation. The effect is important for making quantitative deductions from future data, but does not invalidate the use of O3 as a biomarker for free oxygen. These results make prospects for detection of extrasolar pla...

  20. Nickel(II) dithiocarbamate complexes containing sulforhodamine B as fluorescent probes for selective detection of nitrogen dioxide.

    Science.gov (United States)

    Yan, Yan; Krishnakumar, Saarangan; Yu, Huan; Ramishetti, Srinivas; Deng, Lih-Wen; Wang, Suhua; Huang, Leaf; Huang, Dejian

    2013-04-10

    We synthesized complexes of Ni(II) with dithiocarbamate ligands derived from the ortho and para isomers of sulforhodamine B fluorophores and demonstrated they are highly selective in reactions with nitrogen dioxide (NO2). Compared with the para isomer, the ortho isomer showed a much greater fluorescence increase upon reaction with NO2, which led to oxidation and decomplexation of the dithiocarbamate ligand from Ni(II). We applied this probe for visual detection of 1 ppm NO2 in the gas phase and fluorescence imaging of NO2 in macrophage cells treated with a nitrogen dioxide donor.

  1. Variation in Foliar Nitrogen and Albedo in Response to Elevated Nitrogen and Carbon Dioxide

    Science.gov (United States)

    Wicklein, H. F.; Ollinger, S. V.; Martin, M. M.; Hollinger, D. Y.; Bartlett, M. K.; Richardson, A. D.

    2010-12-01

    It has recently been demonstrated that foliar nitrogen (N) is positively correlated with midsummer canopy albedo over a broad range of plant functional types. However, the mechanism(s) driving the N- albedo relationship remain elusive, and it is unknown whether factors affecting N availability will also influence albedo. To address these questions, we investigated leaf spectral properties from three deciduous broadleaf species subjected to either N (Harvard Forest, MA and Oak Ridge, TN) or CO2 fertilization (Oak Ridge, TN), and compared results to measured chemical and structural properties. We measured reflectance and transmittance along with foliar N, leaf mass per unit area, and water content for stacks of 1, 2, 4, and 8 leaves. For the Oak Ridge, TN site, we also obtained canopy reflectance data from the airborne visible / infrared imaging spectrometer (AVIRIS) to examine whether canopy level spectral responses were consistent with leaf-level results. At the leaf level, results showed no significant differences in reflectance or transmittance between CO2 or N treatments, despite changes in N concentration caused by N fertilization. Although foliar N was significantly correlated with leaf shortwave and near infrared reflectance across species, the slope of both relationships was negative, which ran counter to our expectations. These results do not support the hypothesis that the canopy-level pattern is driven by leaf-level relationships. In contrast to leaf-level observations, remote sensing data from Oak Ridge did indicate an increase in NIR reflectance with N fertilization. Collectively, these results suggest that altered N availability may have an effect on canopy albedo, albeit by mechanisms that involve stem or canopy level processes rather than changes in leaf structure.

  2. Experimental Investigation of a Cryogenic Filter for Separating Solid Carbon Dioxide Particles from Liquid Nitrogen

    Institute of Scientific and Technical Information of China (English)

    LI Juan; SHI Yu-mei; WANG Rong-shun; LI Xiang-dong

    2009-01-01

    This paper presents an investigation of a new method of purifying cryogenic liquid using sintered metallic wire-mesh filter, which has the advantages of high purifying efficiency and preferred strength at absolutely low temperature. Experiments are conducted to purify solid CO2 particles from liquid nitrogen. Temperature and pressure in the upstream and downstream of the filter, and the flow rate of carbon dioxide (CO2) gas and liquid nitrogen are measured, with the gas content of filtrate analyzed using a CO2 concentration detector. It is illustrated that after filtration, the purity of liquid nitrogen (volume fraction) is higher than 99.99%, which means that the volume fraction of CO2 is less than 0.01%. Effects of operation parameters on the performance of the filter, such as pressure drop △p and filtration efficiency E are analyzed quantitatively. The present conclusions will provide a guideline to the optimumal design and operation of sintered metallic wire-mesh filter in cryogenic application.

  3. The Cabauw Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI: design, execution, and early results

    Directory of Open Access Journals (Sweden)

    A. J. M. Piters

    2012-02-01

    Full Text Available From June to July 2009 more than thirty different in-situ and remote sensing instruments from all over the world participated in the Cabauw Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI. The campaign took place at KNMI's Cabauw Experimental Site for Atmospheric Research (CESAR in the Netherlands. Its main objectives were to determine the accuracy of state-of-the-art ground-based measurement techniques for the detection of atmospheric nitrogen dioxide (both in-situ and remote sensing, and to investigate their usability in satellite data validation. The expected outcomes are recommendations regarding the operation and calibration of such instruments, retrieval settings, and observation strategies for the use in ground-based networks for air quality monitoring and satellite data validation. Twenty-four optical spectrometers participated in the campaign, of which twenty-one had the capability to scan different elevation angles consecutively, the so-called Multi-axis DOAS systems, thereby collecting vertical profile information, in particular for nitrogen dioxide and aerosol. Various in-situ samplers and lidar instruments simultaneously characterized the variability of atmospheric trace gases and the physical properties of aerosol particles. A large data set of continuous measurements of these atmospheric constituents has been collected under various meteorological conditions and air pollution levels. Together with the permanent measurement capability at the CESAR site characterizing the meteorological state of the atmosphere, the CINDI campaign provided a comprehensive observational data set of atmospheric constituents in a highly polluted region of the world during summertime. First detailed comparisons performed with the CINDI data show that slant column measurements of NO2, O4 and HCHO with MAX-DOAS agree within 5 to 15%, vertical profiles of NO2 derived from several independent

  4. Final report on COOMET.QM-S1 (COOMET project no 483/RU/09): Supplementary comparison of primary standard gas mixtures: Nitrogen monoxide in nitrogen (50 µmol/mol)

    Science.gov (United States)

    Konopelko, L. A.; Kustikov, Y. A.; Kolobova, A. V.; Shor, N. B.; Efremova, O. V.; Rozhnov, M. S.; Melnyk, D. M.; Kozia, V. G.; Shpilnyi, S. A.; Petryshyn, P. V.; Iakubov, S. E.; Kluchits, A. S.; Ananyin, V. N.; Mironchik, A. M.; Mokhnach, M. V.; Valkova, M.; Stovcik, V.; Walden, J.; Augusto, C. R.; Fioravante, A. L.; Ribeiro, C. C.; Sobrinho, D. C. G.; Oudwater, R. J.; da Cunha, V. S.

    2014-01-01

    Nitrogen monoxide is one of the main contaminants present in the atmospheric air due to emissions of vehicles and power stations. Taking into account the positive experience of VNIIM in the pilot study CCQM-P73 (Nitrogen monoxide gas standards, 30 µmol/mol to 70 µmol/mol), a COOMET project (No 483/RU/09) on the subject was decided and registered in the KCDB as supplementary comparison COOMET.QM-S1. This involved six National Metrology Institutes, aiming to consolidate or support their Calibration and Measurement Capabilities in this field. It was found that most of the results were consistent with the reference (gravimetric) values, with observed differences not exceeding ±1.3% and not exceeding either the appropriate assigned expanded uncertainties. There was, however, one exception: the INMETRO difference from the reference value is slightly higher than the expended uncertainty. The mixtures prepared for this exercise were found to be stable during about one year within the uncertainty of the measurements. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by COOMET, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  5. Role of photoexcited nitrogen dioxide chemistry on ozone formation and emission control strategy over the Pearl River Delta, China

    Science.gov (United States)

    A new hydroxyl radical formation pathway via photo-excited nitrogen dioxide chemistry is incorporated into a chemistry-only box model as well as a 3D air quality model to examine its potential role on ozone formation and emission control strategy over the Pearl River Delta region...

  6. Influence of the atmospheric species water, oxygen, nitrogen and carbon dioxide on the degradation of aluminum doped zinc oxide layers

    NARCIS (Netherlands)

    Theelen, M.; Dasgupta, S.; Vroon, Z.; Kniknie, B.; Barreau, N.; Berkum, J. van; Zeman, M.

    2014-01-01

    Aluminum doped zinc oxide (ZnO:Al) layers were exposed to the atmospheric gases carbon dioxide (CO2), oxygen (O2), nitrogen (N 2) and air as well as liquid H2O purged with these gases, in order to investigate the chemical degradation behavior of these layers. The samples were analyzed by electrical,

  7. Impacts of the solar eclipse of 29 March 2006 on the surface ozone and nitrogen dioxide concentrations at Athens, Greece

    Directory of Open Access Journals (Sweden)

    C. Tzanis

    2007-10-01

    Full Text Available The behavior of surface ozone and nitrogen dioxide concentration as well as the variations in various meteorological parameters before, during and after the total solar eclipse of 29 March 2006 has been examined. This analysis is based on measurements performed at four stations located in the greater Athens basin in Greece. The experimental data demonstrated that the solar eclipse phenomenon affects the surface ozone and nitrogen dioxide concentrations as well as the temperature, the relative humidity and the wind speed near the ground. The reduction of the solar ultraviolet radiation at 312 and 365 nm reached 97% and 93% respectively, while the air temperature dropped, the relative humidity increased and the wind speed decreased. The percentage change (decrease of surface ozone concentration was maximized one hour after the maximum phase of the eclipse due to the decreased efficiency of the photochemical ozone formation. The surface nitrogen dioxide concentration increased and the time lag of the nitrogen dioxide response to the solar eclipse was found to be different for each station. A plausible cause for the increase in NO2 concentration may be the conversion of NO to NO2 through reaction with pre-existing O3 along with the low photolysis rates of NO2 as a consequence of the decreased solar radiation during the solar eclipse event.In general, the time response to the eclipse phenomenon was different for each of the aforementioned parameters.

  8. Nitrogen doping in atomic layer deposition grown titanium dioxide films by using ammonium hydroxide

    Energy Technology Data Exchange (ETDEWEB)

    Kaeaeriaeinen, M.-L., E-mail: marja-leena.kaariainen@lut.fi; Cameron, D.C.

    2012-12-30

    Titanium dioxide films have been created by atomic layer deposition using titanium chloride as the metal source and a solution of ammonium hydroxide in water as oxidant. Ammonium hydroxide has been used as a source of nitrogen for doping and three thickness series have been deposited at 350 Degree-Sign C. A 15 nm anatase dominated film was found to possess the highest photocatalytic activity in all film series. Furthermore almost three times better photocatalytic activity was discovered in the doped series compared to undoped films. The doped films also had lower resistivity. The results from X-ray photoemission spectroscopy showed evidence for interstitial nitrogen in the titanium dioxide structure. Besides, there was a minor red shift observable in the thickest samples. In addition the film conductivity was discovered to increase with the feeding pressure of ammonium hydroxide in the oxidant precursor. This may indicate that nitrogen doping has caused the decrease in the resistivity and therefore has an impact as an enhanced photocatalytic activity. The hot probe test showed that all the anatase or anatase dominant films were p-type and all the rutile dominant films were n-type. The best photocatalytic activity was shown by anatase-dominant films containing a small amount of rutile. It may be that p-n-junctions are formed between p-type anatase and n-type rutile which cause carrier separation and slow down the recombination rate. The combination of nitrogen doping and p-n junction formation results in superior photocatalytic performance. - Highlights: Black-Right-Pointing-Pointer We found all N-doped and undoped anatase dominating films p-type. Black-Right-Pointing-Pointer We found all N-doped and undoped rutile dominating films n-type. Black-Right-Pointing-Pointer We propose that p-n junctions are formed in anatase-rutile mixture films. Black-Right-Pointing-Pointer We found that low level N-doping has increased TiO{sub 2} conductivity. Black

  9. Ice Hockey Lung – A Case of Mass Nitrogen Dioxide Poisoning in The Czech Republic

    Directory of Open Access Journals (Sweden)

    Kristian Brat

    2013-01-01

    Full Text Available Nitrogen dioxide (NO2 is a toxic gas, a product of combustion in malfunctioning ice-resurfacing machines. NO2 poisoning is rare but potentially lethal. The authors report a case of mass NO2 poisoning involving 15 amateur ice hockey players in the Czech Republic. All players were treated in the Department of Respiratory Diseases at Brno University Hospital in November 2010 – three as inpatients because they developed pneumonitis. All patients were followed-up until November 2011. Complete recovery in all but one patient was achieved by December 2010. None of the 15 patients developed asthma-like disease or chronic cough. Corticosteroids appeared to be useful in treatment. Electric-powered ice-resurfacing machines are preferable in indoor ice skating arenas.

  10. Ice hockey lung – a case of mass nitrogen dioxide poisoning in the Czech Republic

    Science.gov (United States)

    Brat, Kristian; Merta, Zdenek; Plutinsky, Marek; Skrickova, Jana; Ing, Miroslav Stanek

    2013-01-01

    Nitrogen dioxide (NO2) is a toxic gas, a product of combustion in malfunctioning ice-resurfacing machines. NO2 poisoning is rare but potentially lethal. The authors report a case of mass NO2 poisoning involving 15 amateur ice hockey players in the Czech Republic. All players were treated in the Department of Respiratory Diseases at Brno University Hospital in November 2010 – three as inpatients because they developed pneumonitis. All patients were followed-up until November 2011. Complete recovery in all but one patient was achieved by December 2010. None of the 15 patients developed asthma-like disease or chronic cough. Corticosteroids appeared to be useful in treatment. Electric-powered ice-resurfacing machines are preferable in indoor ice skating arenas. PMID:24032121

  11. Spatiotemporal inhomogeneity in nitrogen dioxide (NO2) over Fukuoka observed by Car MAX-DOAS

    Science.gov (United States)

    Takashima, H.; Yamaguchi, H.; Maruyama, Y.

    2016-12-01

    Nitrogen dioxide (NO2) observations have been made using car Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) in Fukuoka, an urban area in Japan, to clarify the spatiotemporal inhomogeneity in NO2. We developed instruments for Car MAX-DOAS, and NO2 measurements were conducted on 15 August 2015 and 30 November 2015 on the Fukuoka Urban Expressway, along the closed circular route. For both days, in the morning, the maxima were observed around the city center (in the northeast part of the circular route), whereas in the afternoon, the maxima were observed in the south/southeast part of the circular route (to the south/southeast of the city center). Analysis of the surface wind field indicates that NO2 inhomogeneity is strongly related to the inhomogeneity of NOx sources and to horizontal transport of high concentrations from the city center and low concentrations from the ocean via a land-sea breeze.

  12. Influence of photolysis on multispectral photoacoustic measurement of nitrogen dioxide concentration.

    Science.gov (United States)

    Tian, Guoxun; Moosmüller, Hans; Arnott, W Patrick

    2013-09-01

    Multispectral photoacoustic instruments are commonly used to measure aerosol and nitrogen dioxide (NO2) light absorption coefficients to determine the radiation budget of the atmosphere. Here a new photoacoustic system is developed to explore the effect of photolysis on the measured signal in a multispectral photoacoustic spectrometer In this system, a 405-nm laser is used primarily as light source for photolysis. Additionally, a well-overlapped 532-nm laser, modulated at the resonant frequency of the photoacoustic instrument, is used to probe the NO2 concentration. As a result, the photolysis effect at 405 nm can be observed by the photoacoustic instrument through the 532-nm laser. This work determines an 11% reduction of the photoacoustic signal caused by the photolysis effect for typical conditions, which needs to be taken into account when calibrating multispectral photoacoustic spectrometers with NO2.

  13. Responses of susceptible subpopulations to nitrogen dioxide. Research report, June 1983-January 1988

    Energy Technology Data Exchange (ETDEWEB)

    Morrow, P.E.; Utell, M.J.

    1989-02-01

    Symptom responses and changes in pulmonary function were investigated in people with asthma or chronic obstructive pulmonary disease (COPD) exposed to 0.3 ppm nitrogen dioxide (NO{sub 2}) for four hours. Nonrespiratory-impaired (normal) subjects of comparable ages constituted the control groups. All exposures included periods of exercise and pulmonary function measurements. No significant symptomatic or physiological responses to NO{sub 2} could be detected in either the young or elderly control group. The asthmatic group did not manifest significant reductions in lung function after exposure to 0.3 ppm NO{sub 2}, compared to their preexposure baseline data or to their responses after a comparable four-hour exposure to air. During light exercise, subjects with COPD were progressively responsive to 0.3 ppm NO{sub 2}. Subgroup analyses within the asthmatic, COPD, and elderly normal subject groups and intergroup comparisons yielded significant findings and associations.

  14. Concurrent multiaxis differential optical absorption spectroscopy system for the measurement of tropospheric nitrogen dioxide

    Science.gov (United States)

    Leigh, Roland J.; Corlett, Gary K.; Friess, Udo; Monks, Paul S.

    2006-10-01

    The development of a new concurrent multiaxis (CMAX) sky viewing spectrometer to monitor rapidly changing urban concentrations of nitrogen dioxide is detailed. The CMAX differential optical absorption spectroscopy (DOAS) technique involves simultaneous spectral imaging of the zenith and off-axis measurements of spatially resolved scattered sunlight. Trace-gas amounts are retrieved from the measured spectra using the established DOAS technique. The potential of the CMAX DOAS technique to derive information on rapidly changing concentrations and the spatial distribution of NO2 in an urban environment is demonstrated. Three example data sets are presented from measurements during 2004 of tropospheric NO2 over Leicester, UK (52.62°N, 1.12°W). The data demonstrate the current capabilities and future potential of the CMAX DOAS method in terms of the ability to measure real-time spatially disaggregated urban NO2.

  15. In vivo nitrogen dioxide exposure depresses spleen cell in vitro mitogenic responses: effects of sulfur compounds

    Energy Technology Data Exchange (ETDEWEB)

    Azoulay-Dupuis, E.; Gougerot-Pocidalo, M.A.; Kraus, L.; Moreau, J.

    1987-02-01

    The in vivo mitogenic responses to lipopolysaccharide or concanavalin A by spleen cells of mice exposed to 20 ppm nitrogen dioxide (NO/sub 2/) for 96 hr, were evaluated. (/sup 3/H)Thymidine incorporation after addition of either mitogen, was significantly lower in spleen cells from acutely NO/sub 2/-exposed mice (NO/sub 2/SC) than from control mice, although cell viability was not affected. T- and B-cell mitogenic responses were inhibited to the same extent by NO/sub 2/ exposure. NO/sub 2/SC responses were protected by the thiol compounds 2-mercaptoethanol, L-cysteine, and selenomethionine. No restoration of mitogenic response was observed after treatment with reduced glutathione. Mechanisms accounting for this in vivo NO/sub 2/ immune toxicity, are discussed in terms of oxidative injury.

  16. Transformation of nitrogen dioxide into ozone and prediction of ozone concentrations using multiple linear regression techniques.

    Science.gov (United States)

    Ghazali, Nurul Adyani; Ramli, Nor Azam; Yahaya, Ahmad Shukri; Yusof, Noor Faizah Fitri M D; Sansuddin, Nurulilyana; Al Madhoun, Wesam Ahmed

    2010-06-01

    Analysis and forecasting of air quality parameters are important topics of atmospheric and environmental research today due to the health impact caused by air pollution. This study examines transformation of nitrogen dioxide (NO(2)) into ozone (O(3)) at urban environment using time series plot. Data on the concentration of environmental pollutants and meteorological variables were employed to predict the concentration of O(3) in the atmosphere. Possibility of employing multiple linear regression models as a tool for prediction of O(3) concentration was tested. Results indicated that the presence of NO(2) and sunshine influence the concentration of O(3) in Malaysia. The influence of the previous hour ozone on the next hour concentrations was also demonstrated.

  17. Nitrogen Dioxide Sterilization in Low-Resource Environments: A Feasibility Study.

    Directory of Open Access Journals (Sweden)

    Majdi Shomali

    Full Text Available Access to sterilization is a critical need for global healthcare, as it is one of the prerequisites for safe surgical care. Lack of sterilization capability has driven up healthcare infection rates as well as limited access to healthcare, especially in low-resource environments. Sterilization technology has for the most part been static and none of the established sterilization methods has been so far successfully adapted for use in low-resource environments on a large scale. It is evident that healthcare facilities in low-resource settings require reliable, deployable, durable, affordable, easily operable sterilization equipment that can operate independently of scarce resources. Recently commercialized nitrogen dioxide (NO2 sterilization technology was analyzed and adapted into a form factor suitable for use in low-resource environments. Lab testing was conducted in microbiological testing facilities simulating low-resource environments and in accordance with the requirements of the international sterilization standard ANSI/AAMI/ISO 14937 to assess effectiveness of the device and process. The feasibility of a portable sterilizer based on nitrogen dioxide has been demonstrated, showing that sterilization of medical instruments can occur in a form factor suitable for use in low-resource environments. If developed and deployed, NO2 sterilization technology will have the twin benefits of reducing healthcare acquired infections and limiting a major constraint for access to surgical care on a global scale. Additional benefits are achieved in reducing costs and biohazard waste generated by current health care initiatives that rely primarily on disposable kits, increasing the effectiveness and outreach of these initiatives.

  18. Biocompatibility and antibacterial activity of nitrogen-doped titanium dioxide nanoparticles for use in dental resin formulations

    Science.gov (United States)

    Zane, Andrew; Zuo, Ranfang; Villamena, Frederick A; Rockenbauer, Antal; Digeorge Foushee, Ann Marie; Flores, Kristin; Dutta, Prabir K; Nagy, Amber

    2016-01-01

    The addition of antibacterial functionality to dental resins presents an opportunity to extend their useful lifetime by reducing secondary caries caused by bacterial recolonization. In this study, the potential efficacy of nitrogen-doped titanium dioxide nanoparticles for this purpose was determined. Nitrogen doping was carried out to extend the ultraviolet absorbance into longer wavelength blue light for increased biocompatibility. Titanium dioxide nanoparticles (approximately 20–30 nm) were synthesized with and without nitrogen doping using a sol–gel method. Ultraviolet–Visible spectroscopy indicated a band of trap states, with increasing blue light absorbance as the concentration of the nitrogen dopant increased. Electron paramagnetic resonance measurements indicated the formation of superoxide and hydroxyl radicals upon particle exposure to visible light and oxygen. The particles were significantly toxic to Escherichia coli in a dose-dependent manner after a 1-hour exposure to a blue light source (480 nm). Intracellular reactive oxygen species assay demonstrated that the particles caused a stress response in human gingival epithelial cells when exposed to 1 hour of blue light, though this did not result in detectable release of cytokines. No decrease in cell viability was observed by water-soluble tetrazolium dye assay. The results show that nitrogen-doped titanium dioxide nanoparticles have antibacterial activity when exposed to blue light, and are biocompatible at these concentrations. PMID:27980404

  19. Biocompatibility and antibacterial activity of nitrogen-doped titanium dioxide nanoparticles for use in dental resin formulations.

    Science.gov (United States)

    Zane, Andrew; Zuo, Ranfang; Villamena, Frederick A; Rockenbauer, Antal; Digeorge Foushee, Ann Marie; Flores, Kristin; Dutta, Prabir K; Nagy, Amber

    The addition of antibacterial functionality to dental resins presents an opportunity to extend their useful lifetime by reducing secondary caries caused by bacterial recolonization. In this study, the potential efficacy of nitrogen-doped titanium dioxide nanoparticles for this purpose was determined. Nitrogen doping was carried out to extend the ultraviolet absorbance into longer wavelength blue light for increased biocompatibility. Titanium dioxide nanoparticles (approximately 20-30 nm) were synthesized with and without nitrogen doping using a sol-gel method. Ultraviolet-Visible spectroscopy indicated a band of trap states, with increasing blue light absorbance as the concentration of the nitrogen dopant increased. Electron paramagnetic resonance measurements indicated the formation of superoxide and hydroxyl radicals upon particle exposure to visible light and oxygen. The particles were significantly toxic to Escherichia coli in a dose-dependent manner after a 1-hour exposure to a blue light source (480 nm). Intracellular reactive oxygen species assay demonstrated that the particles caused a stress response in human gingival epithelial cells when exposed to 1 hour of blue light, though this did not result in detectable release of cytokines. No decrease in cell viability was observed by water-soluble tetrazolium dye assay. The results show that nitrogen-doped titanium dioxide nanoparticles have antibacterial activity when exposed to blue light, and are biocompatible at these concentrations.

  20. Indoor Air Quality in Schools (IAQ): The Importance of Monitoring Carbon Dioxide Levels.

    Science.gov (United States)

    Sundersingh, David; Bearg, David W.

    This article highlights indoor air quality and exposure to pollutants at school. Typical air pollutants within schools include environmental tobacco smoke, formaldehyde, volatile organic compounds, nitrogen oxides, carbon monoxide, carbon dioxide, allergens, pathogens, radon, pesticides, lead, and dust. Inadequate ventilation, inefficient…

  1. Atmospheric nitrogen dioxide at ambient levels stimulates growth and development of horticultural plants

    Energy Technology Data Exchange (ETDEWEB)

    Adam, S.E.H.; Shigeto, J. [Hiroshima Univ., Hiroshima (Japan). Dept. of Mathematical and Life Sciences; Sakamoto, A.; Takahashi, M.; Morikawa, H. [Hiroshima Univ., Hiroshima (Japan). Dept. of Mathematical and Life Sciences, Core Research for Evolutional Science and Technology

    2008-02-15

    Studies have demonstrated that ambient levels of atmospheric nitrogen dioxide (NO{sub 2}) can cause Nicotiana plumbaginifolia to double its biomass as well as its cell contents. This paper examined the influence of NO{sub 2} on lettuce, sunflower, cucumber, and pumpkin plants. Plants were grown in environments supplemented with stable isotope-labelled NO{sub 2} for approximately 6 weeks and irrigated with nitrates. Measured growth parameters included leaf number, internode number, stem length, number of flower buds, and root length. Results of the study demonstrated that the addition of NO{sub 2} doubled the aboveground and belowground biomass of sunflowers, while only the aboveground biomass of pumpkin, cucumbers, and lettuces was doubled. Levels of carbon (C), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were also doubled in the lettuce samples. A mass spectrometry analysis showed that only a small percentage of total plant N was derived from NO{sub 2}. It was concluded that exogenous NO{sub 2} additions function as a signal rather than as a significant nutrient source in horticultural plants. 22 refs., 2 tabs., 1 fig.

  2. Ambient concentrations of atmospheric ammonia, nitrogen dioxide and nitric acid in an intensive agricultural region

    Science.gov (United States)

    Zbieranowski, Antoni L.; Aherne, Julian

    2013-05-01

    The spatial and temporal distribution of ambient atmospheric gaseous reactive nitrogen (Nr) species concentrations (ammonia [NH3], nitrogen dioxide [NO2] and nitric acid [HNO3]) were measured at the field scale in an intensive agricultural region in southern Ontario, Canada. Atmospheric concentrations were measured with the Willems badge diffusive passive sampler (18 sites for NH3, 9 sites for NO2 and HNO3) for one year (April 2010-March 2011; under a two week measurement frequency) within a 15 km × 15 km area. Dry deposition was calculated using the inferential method and estimated across the entire study area. The spatial distribution of emission sources associated with agricultural activity resulted in high spatial variability in annual average ambient NH3 concentrations (8 μg m-3 within a 2 km distance, coefficient of variation ˜50%) and estimated dry deposition (4-13 kg N ha-1 yr-1) between sample sites. In contrast, ambient concentrations and deposition of both NO2 (˜5.2->6.5 μg m-3; 1.0-1.5 kg N ha-1 yr-1) and HNO3 (0.6-0.7 μg m-3; 0.5-1 kg N ha-1 yr-1) had low variability (coefficient of variation mycorrhiza and ground vegetation within adjacent semi-natural ecosystems (estimated at ˜10% of the study area).

  3. Hydrothermal Synthesis of Nitrogen-Doped Titanium Dioxide and Evaluation of Its Visible Light Photocatalytic Activity

    Directory of Open Access Journals (Sweden)

    Junjie Qian

    2012-01-01

    Full Text Available Nitrogen-doped titanium dioxide (N-doped TiO2 photocatalyst was synthesized from nanotube titanic acid (denoted as NTA; molecular formula H2Ti2O5·H2O precursor via a hydrothermal route in ammonia solution. As-synthesized N-doped TiO2 catalysts were characterized by means of X-ray diffraction, transmission electron microscopy, diffuse reflectance spectrometry, X-ray photoelectron spectroscopy, electron spin resonance spectrometry and Fourier transform infrared spectrometry. It was found that nanotube ammonium titanate (NAT was produced as an intermediate during the preparation of N-doped TiO2 from NTA, as evidenced by the N1s X-ray photoelectron spectroscopic peak of NH4 + at 401.7 eV. The catalyst showed much higher activities to the degradation of methylene blue and p-chlorophenol under visible light irradiation than Degussa P25. This could be attributed to the enhanced absorption of N-doped TiO2 in visible light region associated with the formation of single-electron-trapped oxygen vacancies and the inhibition of recombination of photo-generated electron-hole pair by doped nitrogen.

  4. Exchange of nitrogen dioxide (NO2) between plants and the atmosphere under laboratory and field conditions

    Science.gov (United States)

    Breuninger, C.; Meixner, F. X.; Thielmann, A.; Kuhn, U.; Dindorf, T.; Kesselmeier, J.

    2012-04-01

    Nitric oxide (NO), nitrogen dioxide (NO2), often denoted as nitrogen oxides (NOx), and ozone (O3) are considered as most important compounds in atmospheric chemistry. In remote areas NOx concentration is related to biological activities of soils and vegetation. The emitted NOx will not entirely be subject of long range transport through the atmosphere. Aside oxidation of NO2 by the OH radical (forming HNO3), a considerable part of it is removed from the atmosphere through the uptake of NO2 by plants. The exchange depends on stomatal activity and on NO2 concentrations in ambient air. It is known that NO2 uptake by plants represents a large NO2 sink, but the magnitude and the NO2 compensation point concentration are still under discussion. Our dynamic chamber system allows exchange measurements of NO2 under field conditions (uncontrolled) as well as studies under controlled laboratory conditions including fumigation experiments. For NO2 detection we used a highly NO2 specific blue light converter (photolytic converter) with subsequent chemiluminescence analysis of the generated NO. Furthermore, as the exchange of NO2 is a complex interaction of transport, chemistry and plant physiology, in our field experiments we determined fluxes of NO, NO2, O3, CO2 and H2O. For a better knowledge of compensation point values for the bi-directional NO2 exchange we investigated a primary representative of conifers, Picea abies, under field and laboratory conditions, and re-analyzed older field data of the deciduous tree Quercus robur.

  5. XPS study of nitrogen dioxide adsorption on metal oxide particle surfaces under different environmental conditions.

    Science.gov (United States)

    Baltrusaitis, Jonas; Jayaweera, Pradeep M; Grassian, Vicki H

    2009-10-01

    The adsorption of nitrogen dioxide on gamma aluminium oxide (gamma-Al(2)O(3)) and alpha iron oxide (alpha-Fe(2)O(3)) particle surfaces under various conditions of relative humidity, presence of molecular oxygen and UV light has been investigated. X-Ray photoelectron spectroscopy (XPS) is used to monitor the different surface species that form under these environmental conditions. Adsorption of NO(2) on aluminum oxide particle surfaces results primarily in the formation of surface nitrate, NO(3)(-) with an oxidation state of +5, as indicated by a peak with binding energy of 407.3 eV in the N1s region. An additional minority species, sensitive to the presence of relative humidity and molecular oxygen, is also observed in the N1s region with lower binding energy of 405.9 eV. This peak is assigned to a surface species in the +4 oxidation state. When irradiated with UV light, other species form on the surface. These surface-bound photochemical products all have lower binding energy, between 400 and 402 eV, indicating reduced nitrogen species in the range of N oxidations states spanning +1 to -1. Co-adsorbed water decreases the amount of these reduced surface-bound products while the presence of molecular oxygen completely suppresses the formation of all reduced nitrogen species on aluminum oxide particle surfaces. For NO(2) on iron oxide particle surfaces, photoreduction is enhanced relative to gamma-Al(2)O(3) and surface bound photoreduced species are observed under all environmental conditions. Complementing the experimental data, N1s core electron binding energies (CEBEs) were calculated using DFT for a number of nitrogen-containing species in the gas phase and adsorbed on an Al(8)O(12) cluster. A range of CEBEs is calculated for various nitrogen species in different adsorption modes and oxidation states. These calculated values are discussed in light of the peaks observed in the XPS N1s region and the possible species that form following NO(2) adsorption and

  6. Permeability of methane, carbon dioxide, oxygen and nitrogen gases using a composite membrane of polyethersulfone/polyamide 11

    Directory of Open Access Journals (Sweden)

    Bahreini Habib

    2016-12-01

    Full Text Available With the expansion of the refining industry, processing and transportation of gas in Iran, it is of high importance to use new technologies of gas separation. Membrane methods, in particular, separation process through polymeric membranes have been growingly used in recent years. The results of multiple studies show that polyether sulfone compounds have a very good performance in manufacturing polymeric membranes in the area of gas separation. However, efforts are ongoing to improve the permeability and selectivity properties of the membranes. This study investigated separation of methane, carbon dioxide, oxygen and nitrogen gases using composite membranes including, polyethersulfone/ polyamide 11 as the polymer. The membrane was made by molding solution with a composition of 9% to 1% polyethersulfone/polyamide -11. Morphology and structure of the membrane made were examined by Fourier infrared transform (FTIR and scanning electron microscopy (SEM. The level of permeability of the membranes was measured by a fixed volume-variable pressure. Overall results indicated that with 6 time increase of pressure, the amount of permeability of carbon dioxide reduced and then increased. Selectivity for dual gases of carbon dioxide- nitrogen increased by the increase in pressure and maximum amount of pressure is 11/187 at 8 times of increase. The selectivity of carbon dioxide- nitrogen has the greatest value among dual gases.

  7. Final report on international comparison EURO.QM-S5/1166: Carbon dioxide mixtures in nitrogen

    Science.gov (United States)

    Dias, Florbela A.; Baptista, Gonçalo; Rakowska, Agata; Chye, Teo Chin; Beng Keat, Teo; Cieciora, Darek; Augusto, Cristiane; Lin, Tsai-Yin; Niederhauser, Bernhard; Fükö, Judit; Sinweeruthai, Ratirat; Johri, Prabha; Akcadag, Fatma; Tarhan, Tanil; van der Veen, Adriaan M. H.; van Wijk, Janneke

    2013-01-01

    This supplementary comparison is designed to test the capabilities of the participants to measure and certify carbon dioxide in nitrogen, and to provide supporting evidence for the CMCs of institutes for carbon dioxide. Indeed this comparison aims to demonstrate the capabilities of IPQ in the production of primary gas mixtures of carbon dioxide in nitrogen and for the participant laboratories to demonstrate their capabilities on certifying primary gas mixtures of percent levels of carbon dioxide in nitrogen. Moreover, a number of NMIs had already participated in the key comparison CCQM-K52, but in a lower range. This EURAMET comparison offers an opportunity to the laboratories to submit CMC in a higher range. In this comparison the laboratories analysed the gas mixtures that are gravimetrically produced and analyzed by IPQ. Each cylinder had its own reference value calculated from the gravimetric preparation. The pressure in the cylinders was approximately 10 MPa; aluminum cylinders of 5 dm3 nominal volume were used. This comparison provides evidence in support of CMCs for carbon dioxide within the range of 1.0 × 10-2 mol/mol to 20.0 × 10-2 mol/mol in a nitrogen/air balance. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by EURAMET, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  8. Annual hydrogen, carbon monoxide and carbon dioxide concentrations and surface to air exchanges in a rural area (Québec, Canada)

    Science.gov (United States)

    Constant, Philippe; Poissant, Laurier; Villemur, Richard

    The industrialization and the demographic expansion have both influenced the biogeochemical cycle of hydrogen (H 2), carbon monoxide (CO) and carbon dioxide (CO 2). In the actual context, knowledge about the spatial distribution of the natural sources and sinks of these trace gases is then crucial to infer possible effects of climate and land use changes on their global budget. This article reports the H 2, CO and CO 2 concentrations and micrometeorological fluxes measured during 1 year in a rural area of the mixed wood ecozone of Canada. Land use represents a critical issue in the control of trace gas natural sources or sinks of that region, which is the most densely habited in Canada. On average, the site emitted CO 2 at a rate of 7.7 g m -2 d -1 and consumed H 2 and CO at 0.34 and 5.1 mg m -2 d -1, respectively. Temperature was the most important factor affecting the H 2 and CO surface to air exchanges. The strength of the soil sink was maximal at the end of the summer, while H 2 and CO emissions were observed at the snow-melting period. In winter, H 2 and CO depositions were attributed to their oxidation by photochemically active compounds within the snow cover. When soil temperature was above 10 °C, trace gas fluxes followed a well-defined diurnal cycle. H 2 and CO 2 deposition rates were positively correlated with H 2O fluxes, while CO followed the inverse trend. CO 2 diurnal variations resulted from a balance between photosynthesis and soil respiration, while some biotic and abiotic factors were proposed to explain the trend observed for H 2. In the case of CO, emissions originating from heat- and photo-induced reactions were involved in the attenuation in the strength of the soil sink during daytime. Measured fluxes were compared with the literature to show the relative importance of the rural areas in the studied trace gases budget.

  9. Air quality at Santiago, Chile: a box modeling approach—I. Carbon monoxide, nitrogen oxides and sulfur dioxide

    Science.gov (United States)

    Jorquera, Héctor

    Ambient monitored data at Santiago, Chile, are analyzed using box models with the goal of assessing contributions of different economic activities to air pollution levels. The period analyzed is 1990-2000, characterized by the introduction of air pollution emissions standards, shift to unleaded gasoline and compressed natural gas, and steady growth of the private and public fleet and the associated fuel consumption growth. The box models explicitly include the seasonal behavior of meteorological variables; the results show that dispersion conditions in fall and winter seasons are 20-30% of the summertime values. This result explains the poor air quality in those seasons and shows that significant emissions reductions are required in order to improve air quality in wintertime. Emissions of CO, NO x and SO 2 are estimated from data on fuel consumption in the city; the estimated parameters are thus fleet-average or industry-average emission factors. In terms of contributions to ambient concentrations, older cars and diesel vehicles are the major contributors to CO and NO x impacts, with more than 60% and 50%, respectively. Ambient concentrations of SO 2 are largely dominated by stationary sources, although long range contributions are not negligible. By contrast, CO and NO x pollution is dominated by local sources within the city boundaries. The box models can be used for forecasting purposes, and they can predict annual average concentrations within 20% of the observed values. The methodology requires data on ambient air quality measurements and fuel consumption statistics, and produces quantitative results, which can be combined with economic models to analyze environmental regulation and public policies.

  10. Nitrogen, tillage, and crop rotation effects on carbon dioxide and methane fluxes from irrigated cropping systems.

    Science.gov (United States)

    Alluvione, Francesco; Halvorson, Ardell D; Del Grosso, Stephen J

    2009-01-01

    Long-term effects of tillage intensity, N fertilization, and crop rotation on carbon dioxide (CO(2)) and methane (CH(4)) flux from semiarid irrigated soils are poorly understood. We evaluated effects of: (i) tillage intensity [no-till (NT) and conventional moldboard plow tillage (CT)] in a continuous corn rotation; (ii) N fertilization levels [0-246 kg N ha(-1) for corn (Zea mays L.); 0 and 56 kg N ha(-1) for dry bean (Phaseolus vulgaris L.); 0 and 112 kg N ha(-1) for barley (Hordeum distichon L.)]; and (iii) crop rotation under NT soil management [corn-barley (NT-CB); continuous corn (NT-CC); corn-dry bean (NT-CDb)] on CO(2) and CH(4) flux from a clay loam soil. Carbon dioxide and CH(4) fluxes were monitored one to three times per week using vented nonsteady state closed chambers. No-till reduced (14%) growing season (154 d) cumulative CO(2) emissions relative to CT (NT: 2.08 Mg CO(2)-C ha(-1); CT: 2.41 Mg CO(2)-C ha(-1)), while N fertilization had no effect. Significantly lower (18%) growing season CO(2) fluxes were found in NT-CDb than NT-CC and NT-CB (11.4, 13.2 and 13.9 kg CO(2)-C ha(-1)d(-1) respectively). Growing season CH(4) emissions were higher in NT (20.2 g CH(4) ha(-1)) than in CT (1.2 g CH(4) ha(-1)). Nitrogen fertilization and cropping rotation did not affect CH(4) flux. Implementation of NT for 7 yr with no N fertilization was not adequate for restoring the CH(4) oxidation capacity of this clay loam soil relative to CT plowed and fertilized soil.

  11. Long term changes of tropospheric Nitrogen Dioxide over Pakistan derived from Ozone Monitoring Instrument (OMI) during the time period of October 2004 to December 2014

    Science.gov (United States)

    Murtaza, Rabbia; Fahim Khokhar, Muhammad

    2016-07-01

    Urban air pollution is causing huge number of diseases and deaths annually. Nitrogen dioxide is an important component of urban air pollution and a precursor to particulate matter, ground level ozone, and acid rain. The satellite based measurements of nitrogen dioxide from Ozone Monitoring Instrument (OMI) can help in analyzing spatio temporal variability in ground level concentrations within a large urban area. In this study, the spatial and temporal distributions of tropospheric nitrogen dioxide Vertical Column Densities (VCDs) over Pakistan are presented from 2004 to 2014. The results showed that the winter season is having high nitrogen dioxide levels as compared to summers. The increase can be attributed to the anthropogenic activities especially thermal power generation and traffic count. Punjab is one of the major provinces with high nitrogen dioxide levels followed by Sindh, Khyber Pakhtunkhwa and Balochistan. Six hotspots have been examined in the present study such as Lahore, Islamabad, Karachi, Faisalabad, Okara and Multan. Emissions of nitrogen compounds from thermal power plants and transportation sector represent a significant fraction of the total nitrogen dioxide emissions to the atmosphere.

  12. Oxidation of diclofenac with chlorine dioxide in aquatic environments: influences of different nitrogenous species.

    Science.gov (United States)

    Wang, Yingling; Liu, Haijin; Liu, Guoguang; Xie, Youhai; Ni, Tianjun

    2015-06-01

    The oxidation of diclofenac (DCF), a non-steroidal anti-inflammatory drug and emerging water pollutant, with chlorine dioxide was investigated under simulated water disinfection conditions. The reaction kinetics as functions of the initial concentrations of DCF, different nitrogenous species, and different pE values were experimentally determined. The results demonstrated that DCF reacted rapidly with ClO2, where more than 75 % of DCF (≤3.00 μM) was removed by 18.94 μM ClO2 within 60 s. All of the reactions followed pseudo first-order kinetics with respect to DCF, and the rate constant, k obs, exhibited a significant decrease from 4.21 × 10(-2) to 8.09 × 10(-3) s(-1), as the initial DCF concentration was increased from 1.00 to 5.00 μM. Furthermore, the degradation kinetics of DCF was clearly dependent on nitrogen-containing ion concentrations in the reaction solution. Ammonium and nitrite ions inhibited the DCF degradation by ClO2, whereas nitrate ion clearly initiated its promotion. In contrast, the inhibitory effect of NO2 (-) was more robust than that of NH4 (+). When the values of pE were gradually increased, the transformation of NH4 (+) to NO2 (-), and subsequently to NO3 (-), would occur, the rate constants were initially decreased, and then increased. When NH4 (+) and NO2 (-) coexisted, the inhibitory effect on the DCF degradation was less than the sum of the partial inhibitory effect. However, when NO2 (-) and NO3 (-) coexisted, the actual inhibition rate was greater than the theoretical estimate. These results indicated that the interaction of NH4 (+) and NO2 (-) was antagonistic, while the coexistence of NO2 (-) and NO3 (-) was observed to have a synergistic effect in aqueous environments.

  13. Field investigations of nitrogen dioxide (NO2 exchange between plants and the atmosphere

    Directory of Open Access Journals (Sweden)

    J. Kesselmeier

    2013-01-01

    Full Text Available The nitrogen dioxide (NO2 exchange between the atmosphere and needles of Picea abies L. (Norway Spruce was studied under uncontrolled field conditions using a dynamic chamber system. This system allows measurements of the flux density of the reactive NO-NO2-O3 triad and additionally of the non-reactive trace gases CO2 and H2O. For the NO2 detection a highly NO2 specific blue light converter was used, which was coupled to chemiluminescence detection of the photolysis product NO. This NO2 converter excludes known interferences with other nitrogen compounds, which occur by using more unspecific NO2 converters. Photo-chemical reactions of NO, NO2, and O3 inside the dynamic chamber were considered for the determination of NO2 flux densities, NO2 deposition velocities, as well as NO2 compensation point concentrations. The calculations are based on a bi-variate weighted linear regression analysis (y- and x-errors considered. The NO2 deposition velocities for spruce, based on projected needle area, ranged between 0.07 and 0.42 mm s−1. The calculated NO2 compensation point concentrations ranged from 2.4 ± 9.63 to 29.0 ± 16.30 nmol m−3 (0.05–0.65 ppb but the compensation point concentrations were all not significant in terms of compensation point concentration is unequal to zero. These data challenge the existence of a NO2 compensation point concentration for spruce. Our study resulted in lower values of NO2 gas exchange flux densities, NO2 deposition velocities and NO2 compensation point concentrations in comparison to most previous studies. It is essential to use a more specific NO2 analyzer than used in previous studies and to consider photo-chemical reactions between NO, NO2, and O3 inside the chamber.

  14. Ab initio energetics, kinetics, and quantum transport characteristics of graphene nanoribbons as nanosensors for detecting nitrogen dioxide

    Science.gov (United States)

    Paulla, Kirti K.; Hassan, Ahmed J.; Knick, Cory R.; Farajian, Amir A.

    2014-03-01

    Molecules adsorption on graphene nanoribbons (GNRs) can be used to engineer and make use of their properties for applications such as energy storage and sensors. We investigate adsorption characteristics by considering nitrogen dioxide as a sample molecule for assessing nanosensor functionality of GNRs. Using ab initio modeling, energetics of various adsorption possibilities are determined and their rate constants are calculated and compared. Nonbonding and weak sp3 adsorptions at the hydrogen-terminated edges are shown to be more feasible than center adsorptions. This shows increased reactivity compared to graphene. Calculated quantum transport responses upon molecules adsorption indicate possibility of sensing extremely low nitrogen dioxide concentrations. Possible approaches for improving gas nanosensor functionality of GNRs are discussed. Reference: RSC Advances, 2013, DOI: 10.1039/c3ra46372a. This research was supported by the National Science Foundation Grant ECCS-0925939.

  15. Spatially resolved measurements of nitrogen dioxide in an urban environment using concurrent multi-axis differential optical absorption spectroscopy

    Directory of Open Access Journals (Sweden)

    R. J. Leigh

    2006-12-01

    Full Text Available A novel system using the technique of concurrent multi-axis differential optical absorption spectroscopy system has been developed and applied to the measurement of nitrogen dioxide in an urban environment. Using five fixed telescopes, slant columns of nitrogen dioxide, ozone, water vapour, and the oxygen dimer, O4, are simultaneously retrieved in five vertically separated viewing directions. The application of this remote sensing technique in the urban environment is explored. Through, the application of several simplifying assumptions a tropospheric concentration of NO2 is derived and compared with an urban background in-situ chemiluminescence detector. The remote sensing and in-situ techniques show good agreement. Owing to the high time resolution of the measurements, the ability to image and quantify plumes within the urban environment is demonstrated. The CMAX-DOAS measurements provide a useful measure of overall NO2 concentrations on a city-wide scale.

  16. Spatially resolved measurements of nitrogen dioxide in an urban environment using concurrent multi-axis differential optical absorption spectroscopy

    Science.gov (United States)

    Leigh, R. J.; Corlett, G. K.; Frieß, U.; Monks, P. S.

    2007-09-01

    A novel system using the technique of concurrent multi-axis differential optical absorption spectroscopy system has been developed and applied to the measurement of nitrogen dioxide in an urban environment. Using five fixed telescopes, slant columns of nitrogen dioxide, ozone, water vapour, and the oxygen dimer, O4, are simultaneously retrieved in five vertically separated viewing directions. The application of this remote sensing technique in the urban environment is explored. Through the application of several simplifying assumptions a tropospheric concentration of NO2 is derived and compared with an urban background in-situ chemiluminescence detector. Trends derived from remote sensing and in-situ techniques show agreement to within 15 to 40% depending on conditions. Owing to the high time resolution of the measurements, the ability to image and quantify plumes within the urban environment is demonstrated. The CMAX-DOAS measurements provide a useful measure of overall NO2 concentrations on a city-wide scale.

  17. Antioxidative Reaction of Carotenes against Peroxidation of Fatty Acids Initiated by Nitrogen Dioxide: A Theoretical Study.

    Science.gov (United States)

    Chen, Shau-Jiun; Huang, Li-Yen; Hu, Ching-Han

    2015-07-30

    In this study, we investigated the antioxidative functions of carotenes (CARs) against the peroxidation of lipids initiated by nitrogen dioxide using density functional theory. The hydrogen-atom transfer (HAT), radical adduct formation (RAF), and electron transfer (ET) mechanisms were investigated. We chose β-carotene (β-CAR) and lycopene (LYC) and compared their NO2(•) initiations and peroxidations with those of linoleic acid (LAH), the model of the lipid. We found that for CARs ET is more likely to occur in the most polar (water) environment than are HAT and RAF. In less polar environments, CARs react more readily with NO2(•) via HAT and RAF than does the lipid model, LAH. Comparatively, reaction barriers for the RAF between CARs and NO2(•) are smaller than those for the HAT. The additions of O2 to the radical intermediates O2N-CAR(•) and CAR(-H)(•) involve sizable barriers and are endergonic. Other than HAT of LAH, we revealed that lipid peroxidation is likely to be initiated by -NO2 addition and the subsequent barrierless addition of O2. Finally, LYC is a more effective antioxidative agent against NO2(•)-initiated lipid peroxidation than is β-CAR.

  18. NDSD-1000: High-resolution, high-temperature Nitrogen Dioxide Spectroscopic Databank

    Science.gov (United States)

    Lukashevskaya, A. A.; Lavrentieva, N. N.; Dudaryonok, A. C.; Perevalov, V. I.

    2016-11-01

    We present a high-resolution, high-temperature version of the Nitrogen Dioxide Spectroscopic Databank called NDSD-1000. The databank contains the line parameters (positions, intensities, self- and air-broadening coefficients, exponents of the temperature dependence of self- and air-broadening coefficients) of the principal isotopologue of NO2. The reference temperature for line intensity is 296 K and the intensity cutoff is 10-25 cm-1/molecule cm-2 at 1000 K. The broadening parameters are presented for two reference temperatures 296 K and 1000 K. The databank has 1,046,808 entries, covers five spectral regions in the 466-4776 cm-1 spectral range and is designed for temperatures up to 1000 K. The databank is based on the global modeling of the line positions and intensities performed within the framework of the method of effective operators. The parameters of the effective Hamiltonian and the effective dipole moment operator have been fitted to the observed values of the line positions and intensities collected from the literature. The broadening coefficients as well as the temperature exponents are calculated using the semi-empirical approach. The databank is useful for studying high-temperature radiative properties of NO2. NDSD-1000 is freely accessible via the internet site of V.E. Zuev Institute of Atmospheric Optics SB RAS ftp://ftp.iao.ru/pub/NDSD/.

  19. Nitrogen Dioxide pollution and hazardous household environment: what impacts more congenital malformations.

    Science.gov (United States)

    Landau, D; Novack, L; Yitshak-Sade, M; Sarov, B; Kloog, I; Hershkovitz, R; Grotto, I; Karakis, I

    2015-11-01

    Nitrogen Dioxide (NO2) is a product of fuel combustion originating mainly from industry and transportation. Studies suggest an association between NO2 and congenital malformations (CM). We investigated an independent effect of NO2 on CM by adjusting to individual factors and household environment in 1024 Bedouin-Arab pregnant women in southern Israel. This population is characterised by high rates of CMs, frequent consanguineous marriages, paternal smoking, temporary housing and usage of open fire for heat cooking. Information on household risk factors was collected during an interview. Ambient measurements of 24-h average NO2 and meteorological conditions were obtained from 13 local monitors. Median value of daily NO2 measured in the area was 6.78ppb. CM was diagnosed in 8.0% (82) of offspring. Maternal NO2 exposure during the 1st trimester >8.6ppb was significantly associated with minor CM (RR=2.68, p=0.029). Major CM were independently associated with maternal juvenile diabetes (RR=9.97, p-value=0.002) and heating by open fire (RR=2.00, p-value=0.049), but not NO2 exposure. We found that NO2 emissions had an independent impact only on minor malformations, whereas major malformations depended mostly on the household environment. Antepartum deaths were associated by maternal morbidity.

  20. Adsorption separation of carbon dioxide, methane and nitrogen on monoethanol amine modified β-zeolite

    Institute of Scientific and Technical Information of China (English)

    Xiaoliang Xu; Xingxiang Zhao; Linbing Sun; Xiaoqin Liu

    2009-01-01

    A new type of composite adsorbents was synthesized by incorporating monoethanol amine (MEA) into β-zeolite. The parent and MEA-functionalized β-zeolites were characterized by X-ray diffraction (XRD), N2 adsorption, and thermogravimetric analysis (TGA). The adsorp-tion behavior of carbon dioxide (CO2), methane (CH4), and nitrogen (N2) on these adsorbents was investigated at 303 K. The results show that the structure of zeolite was well preserved after MEA modification. In comparison with CH4 and N2, CO2 was preferentially adsorbed on the adsorbents investigated. The introduction of MEA significantly improved the selectivity of both CO2/CH4 and CO2/N2, the optimal selectivity of CO2/CH4 can reach 7.70 on 40 wt% of MEA-functionalized β-zeolite (MEA(40)-β) at 1 atm. It is worth noticing that a very high selectivity of CO2/N2 of 25.67 was obtained on MEA(40)-β. Steric effect and chemical adsorbate-adsorbent interaction were responsible for such high adsorption selectivity of CO2. The present MEA-functionalized β-zeolite adsorbents may be a good candidate for applications in flue gas separation, as well as natural gas and landfill gas purifications.

  1. Mineral elements of subtropical tree seedlings in response to elevated carbon dioxide and nitrogen addition.

    Directory of Open Access Journals (Sweden)

    Wenjuan Huang

    Full Text Available Mineral elements in plants have been strongly affected by increased atmospheric carbon dioxide (CO2 concentrations and nitrogen (N deposition due to human activities. However, such understanding is largely limited to N and phosphorus in grassland. Using open-top chambers, we examined the concentrations of potassium (K, calcium (Ca, magnesium (Mg, aluminum (Al, copper (Cu and manganese (Mn in the leaves and roots of the seedlings of five subtropical tree species in response to elevated CO2 (ca. 700 μmol CO2 mol(-1 and N addition (100 kg N ha(-1 yr(-1 from 2005 to 2009. These mineral elements in the roots responded more strongly to elevated CO2 and N addition than those in the leaves. Elevated CO2 did not consistently decrease the concentrations of plant mineral elements, with increases in K, Al, Cu and Mn in some tree species. N addition decreased K and had no influence on Cu in the five tree species. Given the shifts in plant mineral elements, Schima superba and Castanopsis hystrix were less responsive to elevated CO2 and N addition alone, respectively. Our results indicate that plant stoichiometry would be altered by increasing CO2 and N deposition, and K would likely become a limiting nutrient under increasing N deposition in subtropics.

  2. LPG ammonia and nitrogen dioxide gas sensing properties of nanostructured polypyrrole thin film

    Energy Technology Data Exchange (ETDEWEB)

    Bagul, Sagar B., E-mail: nano.sbbagul@gmail.com; Upadhye, Deepak S.; Sharma, Ramphal, E-mail: rps.phy@gmail.com [Thin Film and Nanotechnology Laboratory, Department of Nanotechnology, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad (India)

    2016-05-06

    Nanostructured Polypyrrole thin film was synthesized by easy and economic chemical oxidative polymerization technique on glass at room temperature. The prepared thin film of Polypyrrole was characterized by optical absorbance study by UV-visible spectroscopy and electrical study by I-V measurement system. The optical absorbance spectrum of Polypyrrole shows two fundamental peaks in region of 420 and 890 nm, which confirms the formation of Polypyrrole on glass substrate. The I-V graph of nanostructured Polypyrrole represents the Ohmic nature. Furthermore, the thin film of Polypyrrole was investigated by Scanning electron microscopy for surface morphology study. The SEM micrograph represents spherical nanostructured morphology of Polypyrrole on glass substrate. In order to investigate gas sensing properties, 100 ppm of LPG, Ammonia and Nitrogen Dioxide were injected in the gas chamber and magnitude of resistance has been recorded as a function of time in second. It was observed that nanostructured Polypyrrole thin film shows good sensing behavior at room temperature.

  3. Microhardness tests of stainless steel 52100 implanted with nitrogen and carbon dioxide

    CERN Document Server

    Mardanian, M; Taheri, Z

    2003-01-01

    In this research work, samples of stainless steel 52100 disks were implanted with nitrogen and carbon dioxide ions at the energy of 90 keV. Microhardness measurement were performed to determine the hardness of the surface. The N-2 sup + implanted steels at the doses of 1x10 sup 1 8 ions cm sup sub 2 gave the highest hardness of 49.70%, while for the CO sub 2 sup + ions implantation, the hardness of 17% and 5% were obtained at the doses of 3x10 sup 1 8 and 1x10 sup 1 9 ions cm sup - 2, respectively. To support the interpretation of our microhardness results the implanted surface were analyzed by the use of XRD method. Our results indicated that the hardness of the N sub 2 sup + implanted samples are due to formation of beta-Cr N phase in the surface layer, while in the CO sub 2 + implanted samples no observation of carbon as graphite or carbide was made. In addition, the absence of any hump in the XRD spectrum indicating that carbon is not in the amorphous phase either.

  4. Revising the slant column density retrieval of nitrogen dioxide observed by the Ozone Monitoring Instrument

    Science.gov (United States)

    Marchenko, S.; Krotkov, N. A.; Lamsal, L. N.; Celarier, E. A.; Swartz, W. H.; Bucsela, E. J.

    2015-06-01

    Nitrogen dioxide retrievals from the Aura/Ozone Monitoring Instrument (OMI) have been used extensively over the past decade, particularly in the study of tropospheric air quality. Recent comparisons of OMI NO2 with independent data sets and models suggested that the OMI values of slant column density (SCD) and stratospheric vertical column density (VCD) in both the NASA OMNO2 and Royal Netherlands Meteorological Institute DOMINO products are too large, by around 10-40%. We describe a substantially revised spectral fitting algorithm, optimized for the OMI visible light spectrometer channel. The most important changes comprise a flexible adjustment of the instrumental wavelength shifts combined with iterative removal of the ring spectral features; the multistep removal of instrumental noise; iterative, sequential estimates of SCDs of the trace gases in the 402-465 nm range. These changes reduce OMI SCD(NO2) by 10-35%, bringing them much closer to SCDs retrieved from independent measurements and models. The revised SCDs, submitted to the stratosphere-troposphere separation algorithm, give tropospheric VCDs ˜10-15% smaller in polluted regions, and up to ˜30% smaller in unpolluted areas. Although the revised algorithm has been optimized specifically for the OMI NO2 retrieval, our approach could be more broadly applicable.

  5. Roles of nitrogen, oxygen, and carbon dioxide in compressed-air narcosis.

    Science.gov (United States)

    Hesser, C M; Fagraeus, L; Adolfson, J

    1978-12-01

    In an attempt to determine the roles of nitrogen, oxygen, and carbon dioxide in compressed-air narcosis, the effects on performance (mental function and manual dexterity) of adding CO2 in various concentrations to the inspired gas under three different conditions were studied in eight healthy male volunteers. The three conditions were: (1) air breathing at 1.3 ATA; (2) oxygen breathing at 1.7 ATA; and (3) air breathing at 8.0 ATA (same inspired O2 pressure as in (2)). By relating performance to the changes induced in end-tidal (alveolar) gas pressures, and comparing the data from the three conditions, we arrived at the following results and conclusions. A rise in O2 pressure to 1.65 ATA, or in N2 pressure to 6.3 ATA at a constant high PO2 level, caused a significant decrement of 10% in mental function but no consistent effect on psychomotor function. A rise in end-tidal PCO2 of 10 mmHg caused an impairment of approximately 10% in both mental and psychomotor functions. The results suggest that, at raised partial pressures, all three gases have narcotic properties, and that the mechanism of CO2 narcosis differs fundamentally from that of N2 and O2 narcosis.

  6. Pulse radiolysis study of the reactions of catechins with nitrogen dioxide

    Science.gov (United States)

    Gebicki, Jerzy L.; Meisner, Piotr; Stawowska, Katarzyna; Gebicka, Lidia

    2012-12-01

    Nitrogen dioxide (•NO2), one of the oxidizing radicals formed in vivo is suspected to play a role in various pathophysiological processes. The reactions of •NO2 with dietary catechins, the group of flavonoids present in high amounts in green tea and red wine, have been investigated by pulse radiolysis method. The kinetics of the reaction of •NO2 with gallic acid have been also studied for comparison. The spectra of transient intermediates are presented. The rate constants of the reaction of •NO2 with catechin, epigallocatechin, epigallocatechin gallate and gallic acid determined by the competition method with 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulfonate) at pH 7.0 and room temperature have been found to be 0.9, 1.0, 2.3 and 0.5×108 M-1 s-1, respectively. The values for catechins are among the highest reported for the reactions of •NO2 with non-radical compounds.

  7. Protection with cycloheximide or emetine against pulmonary edema induced by ozone or nitrogen dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Nambu, Z.; Yokoyama, E.

    1982-03-01

    Pretreatment with cycloheximide or emetine provided significant protection against pulmonary edema in rats exposed to ozone or nitrogen dioxide. Other inhibitors of protein-synthesis, actinomycin D or puromycin, failed to show such effects. Possible actions of these agents as well as the doses and times that afforded the significant protection were investigated. These agents, by themselves, did not alter the water content of the lungs. In vitro study revealed that both cycloheximide and emetine hardly acted as scavengers of oxidant. Pretreatment with either agent was associated with a significant increase in the activity of glucose 6-phosphate dehydrogenase of the lungs, but the increase did not necessarily coincide with the protection. Activity levels of non-protein SH, glutathione-peroxidase and -reductase in the lungs of rats treated with either agent were scarcely altered. The effect of these agents administered in vivo or in vitro on the in vitro lipid peroxidation by air was also investigated. Other possible mechanisms of these agents responsible for the protective effect against pulmonary edema induced by oxidants were also discussed.

  8. Sequential changes in canine pulmonary epithelial and endothelial cell functions after nitrogen dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Man, S.F.; Williams, D.J.; Amy, R.A.; Man, G.C.; Lien, D.C. (Univ. of Alberta, Edmonton (Canada))

    1990-07-01

    Through its ability to cause lipid peroxidation, nitrogen dioxide (NO{sub 2}) may affect the functional properties of both the pulmonary epithelium and endothelium. We evaluated this possibility in 13 mongrel dogs by exposing these animals to 200 or 400 ppm NO{sub 2} for 1 h. The changes in pulmonary epithelial permeability (using a radioaerosol technique), FRC, and endothelial function (the removal of radiolabeled serotonin, ({sup 14}C)5-HT, and prostaglandin E1, (3H)PGE1, from the pulmonary circulation) were measured at 1 h and at 2, 7, or 14 days after NO{sub 2} exposure. In another six dogs, we evaluated changes in cell population and albumin in bronchoalveolar lavage (BAL) fluid caused by NO{sub 2}. In the first two days after NO{sub 2} exposure, focal pulmonary edema was documented on microscopy, radioaerosol clearance was delayed, and FRC decreased slightly. BAL showed a marked increase in albumin, but the removal of trace amounts of 5-HT and PGE1 by the endothelium was not altered. All physiologic abnormalities returned to normal with time.

  9. Enhanced detection of nitrogen dioxide via combined heating and pulsed UV operation of indium oxide nano-octahedra.

    Science.gov (United States)

    Gonzalez, Oriol; Roso, Sergio; Vilanova, Xavier; Llobet, Eduard

    2016-01-01

    We report on the use of combined heating and pulsed UV light activation of indium oxide gas sensors for enhancing their performance in the detection of nitrogen dioxide in air. Indium oxide nano-octahedra were synthesized at high temperature (900 °C) via vapour-phase transport and screen-printed onto alumina transducers that comprised interdigitated electrodes and a heating resistor. Compared to the standard, constant temperature operation of the sensor, mild heating (e.g., 100 °C) together with pulsed UV light irradiation employing a commercially available, 325 nm UV diode (square, 1 min period, 15 mA drive current signal), results in an up to 80-fold enhancement in sensitivity to nitrogen dioxide. Furthermore, this combined operation method allows for making savings in power consumption that range from 35% to over 80%. These results are achieved by exploiting the dynamics of sensor response under pulsed UV light, which convey important information for the quantitative analysis of nitrogen dioxide.

  10. Enhanced detection of nitrogen dioxide via combined heating and pulsed UV operation of indium oxide nano-octahedra

    Directory of Open Access Journals (Sweden)

    Oriol Gonzalez

    2016-10-01

    Full Text Available We report on the use of combined heating and pulsed UV light activation of indium oxide gas sensors for enhancing their performance in the detection of nitrogen dioxide in air. Indium oxide nano-octahedra were synthesized at high temperature (900 °C via vapour-phase transport and screen-printed onto alumina transducers that comprised interdigitated electrodes and a heating resistor. Compared to the standard, constant temperature operation of the sensor, mild heating (e.g., 100 °C together with pulsed UV light irradiation employing a commercially available, 325 nm UV diode (square, 1 min period, 15 mA drive current signal, results in an up to 80-fold enhancement in sensitivity to nitrogen dioxide. Furthermore, this combined operation method allows for making savings in power consumption that range from 35% to over 80%. These results are achieved by exploiting the dynamics of sensor response under pulsed UV light, which convey important information for the quantitative analysis of nitrogen dioxide.

  11. Change in genotoxicity of wastewater during chlorine dioxide and chlorine disinfections and the influence of ammonia nitrogen

    Institute of Scientific and Technical Information of China (English)

    WANG Lisha; HU Hongying; WANG Chao; Koichi Fujie

    2007-01-01

    The effects of chlorine dioxide and chlorine disinfections on the genotoxicity of different biologically treated sewage wastewater samples were studied by umu-test.The experiment results showed that when chlorine dioxide dosage was increased from 0 to 30 mg/L,the genotoxicity of wastewater first decreased rapidly and then tended to be stable,while when the chlorine dosage was increased from 0 to 30 mg/L,the genotoxicity of wastewater changed diversely for different samples.It was then found that ammonia nitrogen did not affect the change of genotoxicity during chlorine dioxide disinfection of wastewater,while it greatly affected the change of genotoxicity during chlorine disinfection of wastewater.When the concentration of ammonia nitrogen was low(<10-20mg/L),the genotoxicity of wastewater decreased after chlorine disinfection,and when the concentration of ammonia nitrogen was high(>10-20 mg/L),the genotoxicity of wastewater increased after chlorine disinfection.

  12. Further studies on the effect of nitrogen dioxide on mast cells: The effect of the metabolite, nitrite

    Energy Technology Data Exchange (ETDEWEB)

    Fujimaki, Hidekazu (National Institute for Environmental Studies, Onogawa (Japan)); Ozawa, Masashi (The Jikei Univ. School of Medicine, Tokyo (Japan)); Bissonnette, E.; Befus, A.D. (Univ. of Calgary, Alberta (Canada))

    1993-05-01

    To evaluate the relationship between atmospheric nitrogen dioxide exposure and the development of allergic diseases, the effects of nitrite as a chemical product of inhaled nitrogen dioxide on mast cell functions were investigated. We have studied nitride-induced histamine release from two functionally distinct mast cell populations, namely peritoneal mast cells (PMC) and intestinal mucosal mast cells (IMMC) of Nippostrongylus brasiliensis-infected rats. High concentrations of nitrite alone (10, 20, and 50 mM) induced histamine release from IMMC, but not from PMC. Moreover, histamine release from PMC and IMMC stimulated with sensitizing antigen was significantly enhanced by pretreatment with 50 mM nitrite or nitrate. No differences in histamine release from nitrite-treated and control PMC were seen below 1 mM. To investigate the effect of nitrite on tumor cell cytotoxic activity, PMC were incubated with various concentrations of nitrite. Pretreatment with 5 and 50 mM nitrite markedly depressed tumor necrosis factor (TNF)-[alpha]-dependent natural cytotoxicity of PMC for the tumor target WEHI-164. Thus, high concentrations of nitrite enhanced mast cell histamine release, but depressed TNF-[alpha]-dependent cytotoxicity. However, low concentrations of nitrite (<1 mM) that would normally be produced by short-term atmospheric exposure to nitrogen dioxide may have no significant effects on mast cell functions. 27 refs., 3 figs., 1 tab.

  13. Effects of local meteorology and aerosols on ozone and nitrogen dioxide retrievals from OMI and pandora spectrometers in Maryland, USA during DISCOVER-AQ 2011.

    Science.gov (United States)

    Reed, Andra J; Thompson, Anne M; Kollonige, Debra E; Martins, Douglas K; Tzortziou, Maria A; Herman, Jay R; Berkoff, Timothy A; Abuhassan, Nader K; Cede, Alexander

    An analysis is presented for both ground- and satellite-based retrievals of total column ozone and nitrogen dioxide levels from the Washington, D.C., and Baltimore, Maryland, metropolitan area during the NASA-sponsored July 2011 campaign of Deriving Information on Surface COnditions from Column and VERtically Resolved Observations Relevant to Air Quality (DISCOVER-AQ). Satellite retrievals of total column ozone and nitrogen dioxide from the Ozone Monitoring Instrument (OMI) on the Aura satellite are used, while Pandora spectrometers provide total column ozone and nitrogen dioxide amounts from the ground. We found that OMI and Pandora agree well (residuals within ±25 % for nitrogen dioxide, and ±4.5 % for ozone) for a majority of coincident observations during July 2011. Comparisons with surface nitrogen dioxide from a Teledyne API 200 EU NOx Analyzer showed nitrogen dioxide diurnal variability that was consistent with measurements by Pandora. However, the wide OMI field of view, clouds, and aerosols affected retrievals on certain days, resulting in differences between Pandora and OMI of up to ±65 % for total column nitrogen dioxide, and ±23 % for total column ozone. As expected, significant cloud cover (cloud fraction >0.2) was the most important parameter affecting comparisons of ozone retrievals; however, small, passing cumulus clouds that do not coincide with a high (>0.2) cloud fraction, or low aerosol layers which cause significant backscatter near the ground affected the comparisons of total column nitrogen dioxide retrievals. Our results will impact post-processing satellite retrieval algorithms and quality control procedures.

  14. Effect of low-intensity focused ultrasound on endothelin-1, nitrogen monoxide and oxytocin receptor in the uterine tissues of Sprague-Dawley rats following abortion.

    Science.gov (United States)

    Zhang, Yanxia; Guo, Jufang; Lin, Chuan; Lu, L U; Li, Chengzhi

    2016-03-01

    The aim of the present study was to investigate the effect of low-intensity focused ultrasound on endothelin-1 (ET-1), nitrogen monoxide (NO) and oxytocin receptor (OXTR) levels in the uterine tissues of Sprague-Dawley (SD) rats following abortion. A total of 30 SD rats undergoing complete abortion were randomly divided into ultrasound irradiation and sham irradiation groups (15 rats per group). The rats in the ultrasound irradiation group were treated with low-intensity ultrasound (sound intensity, 2 W/cm(2); frequency, 0.8 MHz) for 30 min daily for 5 consecutive days, and those in the sham irradiation group received sham treatment. The uterine tissue was removed to measure the levels of ET-1, NO and OXTR using the enzyme-linked immunosorbent assay and immunohistochemistry, respectively. The ET-1 level in the uterine tissues was significantly higher in the ultrasound irradiation group compared to the sham irradiation group (P0.05). In the uterine myometrium and endometrium, the strong positive expression of OXTR was observed in the ultrasound irradiation group, which was significantly higher compared to the sham irradiation group (Pultrasound could promote uterine involution by increasing ET-1 levels, modifying the balance of ET-1 and NO, and enhancing the expression of OXTR in the uterine myometrium and endometrium.

  15. Continuous measurements of nitrous oxide, carbon monoxide, methane and carbon dioxide in the surface ocean with novel laser-absorption analysers

    Science.gov (United States)

    Kaiser, Jan; Grefe, Imke; Wager, Natalie; Bakker, Dorothee C. E.; Lee, Gareth A.

    2013-04-01

    In recent years, improvements in spectroscopic technology have revolutionised atmospheric trace gas research. In particular, cavity-based optical absorption analysers allow determination of gas concentrations with high frequency, repeatability, reproducibility and long-term stability. These qualities make them particularly suitable for autonomous measurements on voluntary observing ships (VOS). Here, we present results from three of the first deployments of such analysers on research ships, as a first step towards VOS installations. Los Gatos off-axis ICOS (Integrated Cavity Output Spectroscopy) analysers were used to measure nitrous oxide (N2O), carbon monoxide (CO), methane (CH4) and carbon dioxide (CO2) mixing ratios in ocean surface water during research cruises in 2010, 2011 and 2012. The analysers were coupled to an equilibrator fed by the scientific seawater supply in the ship's laboratories. The equilibrator measurements were alternated with regular measurements of marine air and calibrated standard gases. Short-term precision for 10 s-average N2O mole fractions at an acquisition rate of 1 Hz was better than 0.2 nmol mol-1. The same value was achieved for duplicate measurements of a standard gas analysed within 1 hour of each other. The response time to concentration changes in water was 142-203 s, depending on the headspace flow rate. During the first deployment on the AMT20 cruise (Atlantic Meridional Transect, Southampton to Punta Arenas, 12 October to 25 November 2010), we unexpectedly found the subtropical gyres to be slightly undersaturated in N2O, implying that this region acted as a sink for this greenhouse gas. In contrast, the equatorial region was supersaturated and a source of nitrous oxide to the atmosphere. Mean sea-to-air fluxes were overall small and ranged between -1.6 and 0.11 μmol m-2 d-1 (negative fluxes imply an net uptake by the ocean). Despite the good short-term repeatability, significant calibration drift occurred between the six

  16. Investigation of the Nitrogen Dioxide Pollution in Urban Areas using a New Portable ICAD Instrument

    Science.gov (United States)

    Horbanski, Martin; Pöhler, Denis; Adler, Tim; Lampel, Johannes; Kanatschnig, Florian; Oesterle, Tobias; Reh, Miriam; Platt, Ulrich

    2016-04-01

    Nitrogen oxides (NOx) and especially nitrogen dioxide (NO2), are still among of the most problematic pollutants in urban areas not only in developing, but also in industrialized countries. Despite the measures taken to reduce their emissions, NO2 concentrations in many urban areas exceed the WHO recommended limits of 40 μg/m3 for annual mean and 200 μg/m3 for 1 hour mean. Additionally it is known that the NO2 concentration in urban areas has a strong spatial and temporal variability, due to the large number of NOx emitting point sources (mainly traffic) found in densely populated areas. However, the layout of air monitoring networks in most urban areas, installed to continuously monitor the officially prescribed NO2 limits, does not reflect the high spatial variability because they only conduct measurements at a single or few selected sampling points, mainly on major roads, which are often not representative for the whole urban area. At present these uncertainties about the spatial NO2 distribution constitute severe limitations for the assessment of health risks, for the quality of chemical model calculations, and for developing effective measures to reduce NOx emissions. We developed a new light-weight and portable ICAD (Iterative Cavity Enhanced DOAS) instrument which detects NO2 at a detection limit as low as 0.2 μg/m3 with a high time resolution of seconds. The instrument is based on the Cavity Enhanced (CE-) DOAS technique, which directly identifies and quantifies NO2 by its differential optical absorption. Therefore, it does not suffer from interferences by other trace gas species like O3 or NOy. This is a great advantage over other NO2 instruments (e.g. solid state detectors or chemiluminescence instruments). We present the result of ICAD NO2 measurements, which we recently performed in more than 10 German cities. The ICAD instrument was mounted on mobile platforms like cars and bicycles, measuring the NO2 concentrations along carefully selected tracks

  17. Nitrate transporters in leaves and their potential roles in foliar uptake of nitrogen dioxide

    Directory of Open Access Journals (Sweden)

    Yanbo eHu

    2014-07-01

    Full Text Available While plant roots are specialized organs for the uptake and transport of water and nutrients, the absorption of gaseous or liquid mineral elements by aerial plant parts has been recognized since more than one century. Nitrogen (N is an essential macronutrient which generally absorbed either as nitrate (NO3- or ammonium (NH4+ by plant roots. Gaseous nitrogen pollutants like N dioxide (NO2 can also be absorbed by plant surfaces and assimilated via the NO3– assimilation pathway. The subsequent NO3– flux may induce or repress the expression of various NO3–-responsive genes encoding for instance, the transmembrane transporters, NO3–/NO2– (nitrite reductase, or assimilatory enzymes involved in N metabolism. Based on the existing information, the aim of this review was to theoretically analyze the potential link between foliar NO2 absorption and N transport and metabolism. For such purpose, an overview of the state of knowledge on the NO3– transporter genes identified in leaves or shoots of various species and their roles for NO3– transport across the tonoplast and plasma membrane, in addition to the process of phloem loading is briefly provided. It is assumed that a NO2-induced ac-cumulation of NO3–/NO2– may alter the expression of such genes, hence linking transmembrane NO3– transporters and foliar uptake of NO2. It is likely that NRT1/NRT2 gene expression and spe-cies-dependent apoplastic buffer capacity may be also related to the species-specific foliar NO2 uptake process. It is concluded that further work focusing on the expression of NRT1 (NRT1.1, NRT1.7, NRT1.11 and NRT1.12, NRT2 (NRT2.1, NRT2.4 and NRT2.5 and chloride channel family genes (CLCa and CLCd may help us elucidate the physiological and metabolic response of plants fumigated with NO2.

  18. Toxicity of titanium dioxide nanoparticles to Chlorella vulgaris Beyerinck (Beijerinck) 1890 (Trebouxiophyceae, Chlorophyta) under changing nitrogen conditions.

    Science.gov (United States)

    Dauda, Suleiman; Chia, Mathias Ahii; Bako, Sunday Paul

    2017-06-01

    The broad application of titanium dioxide nanoparticles (n-TiO2) in many consumer products has resulted in the release of substantial quantities into aquatic systems. While n-TiO2 have been shown to induce some unexpected toxic effects on aquatic organisms such as microalgae, the influence of changing nutrient conditions on the toxicity of the metal has not been investigated. We evaluated the toxicity of n-TiO2 to Chlorella vulgaris under varying nitrogen conditions. Limited nitrogen (2.2μM) decreased growth and biomass (dry weight and pigment content), while lipid peroxidation (malondialdehyde content), glutathione S-transferase activity (GST) and peroxidase (POD) activity were increased. Similarly, exposure to n-TiO2 under replete nitrogen condition resulted in a general decrease in growth and biomass, while GST and POD activities were significantly increased. The combination of limited nitrogen with n-TiO2 exposure further decreased growth and biomass, and increased GST and POD activities of the microalga. These results suggest that in addition to the individual effects of each investigated condition, nitrogen limitation makes C. vulgaris more susceptible to the effects of n-TiO2 with regard to some physiological parameters. This implies that the exposure of C. vulgaris and possibly other green algae to this nanoparticle under limited or low nitrogen conditions may negatively affect their contribution to primary production in oligotrophic aquatic ecosystems. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. The sensitivity of OMI-derived nitrogen dioxide to boundary layer temperature inversions

    Science.gov (United States)

    Wallace, Julie; Kanaroglou, Pavlos

    We assess the sensitivity of tropospheric nitrogen dioxide (NO 2) derived from the Ozone Monitoring Instrument (OMI), to episodes of temperature inversion in the lower boundary layer. Vertical temperature data were obtained from a 91-m meteorological tower located in the study area, which is centered on the Hamilton Census Metropolitan Area, Ontario, Canada. Hamilton is an industrial city with high traffic volumes, and is therefore subjected to high levels of pollution. Pollution buildup is amplified by frequent temperature inversions which are commonly radiative, but are also induced by local physiography, proximity to Lake Ontario, and regional meteorology. The four-year period from January 2005 to December 2008 was investigated. Ground-level data for validation were obtained from in situ air quality monitors located in the study area. The results indicate that OMI is sensitive to changes in the NO 2 levels during temperature inversions, and exhibits changes which roughly parallel those of in situ monitors. Overall, an 11% increase in NO 2 was identified by OMI on inversion days, compared to a 44% increase measured by in situ monitors. The weekend effect was clearly exhibited under both normal and inversion scenarios with OMI. Seasonal and wind direction patterns also correlated fairly well with ground-level data. Temperature inversions have resulted in poor air quality episodes which have severely compromised the health of susceptible populations, sometime leading to premature death. The rationale for this study is to further assess the usefulness of OMI for population exposure studies in areas with sparse resources for ground-level monitoring.

  20. Pro-inflammatory responses of human bronchial epithelial cells to acute nitrogen dioxide exposure.

    Science.gov (United States)

    Ayyagari, Vijayalakshmi N; Januszkiewicz, Adolph; Nath, Jayasree

    2004-04-15

    Nitrogen dioxide (NO2) is an environmental oxidant, known to be associated with lung epithelial injury. In the present study, cellular pro-inflammatory responses following exposure to a brief high concentration of NO2 (45 ppm) were assessed, using normal human bronchial epithelial (NHBE) cells as an in vitro model of inhalation injury. Generation and release of pro-inflammatory mediators such as nitric oxide (NO), IL-8, TNF-alpha, IFN-gamma and IL-1beta were assessed at different time intervals following NO2 exposure. Effects of a pre-existing inflammatory condition was tested by treating the NHBE cells with different inflammatory cytokines such as IFN-gamma, IL-8, TNF-alpha, IL-1beta, either alone or in combination, before exposing them to NO2. Immunofluorescence studies confirmed oxidant-induced formation of 3-nitrotyrosine in the NO2-exposed cells. A marked increase in the levels of nitrite (as an index of NO) and IL-8 were observed in the NO2-exposed cells, which were further enhanced in the presence of the cytokines. Effects of various NO inhibitors combined, with immunofluorescence and Western blotting data, indicated partial contribution of the nitric oxide synthases (NOSs) toward the observed increase in nitrite levels. Furthermore, a significant increase in IL-1beta and TNF-alpha generation was observed in the NO2-exposed cells. Although NO2 exposure alone did induce slight cytotoxicity (<12%), but presence of inflammatory cytokines such as TNF-alpha and IFN-gamma resulted in an increased cell death (28-36%). These results suggest a synergistic role of inflammatory mediators, particularly of NO and IL-8, in NO2-mediated early cellular changes. Our results also demonstrate an increased sensitivity of the cytokine-treated NHBE cells toward NO2, which may have significant functional implications in vivo.

  1. Carbon and carbon dioxide accumulation by marandu grass under nitrogen fertilization and irrigation

    Directory of Open Access Journals (Sweden)

    Elisângela Dupas

    2016-06-01

    Full Text Available ABSTRACT Nitrogen (N is the most limiting nutrient for growth of forage grasses, especially in conditions of low water availability. Therefore, it is important to evaluate the effect of N fertilization and irrigation on the accumulation of carbon (C and carbon dioxide (CO2 by marandu grass in the Cerrado Paulista, in the rainy and dry seasons. Experiments were conducted to evaluate N fertilization in each season, with and without irrigation. Five N rates were used (0, 50, 100, 150 and 200 kg ha-1 per cutting, using urea as N source, totaling 0, 300, 600, 900 and 1200 kg ha-1 in the rainy season and 0, 100, 200, 300 and 400 kg ha-1 in the dry season. The experiments were arranged in a split-plot randomized block design. There was no significant interaction (p > 0.05 between N and time of fertilization in the irrigated experiment. However, N promoted a quadratic effect in organic matter production (OMP, accumulation of C and CO2 by marandu grass, while there was no influence of the seasons. In the non-irrigated experiment, the interaction between N rates and seasons was significant (p < 0.05 only for the rainy season. Organic matter production and C and CO2 accumulation was greater in the rainy season than in the dry season. Irrigation provided increases of approximately 20% in C and CO2 accumulation. The use of N and irrigation increases the accumulation of C and CO2 by marandu grass, and this increase is higher during the rainy season.

  2. Nitrogen dioxide concentrations in neighborhoods adjacent to a commercial airport: a land use regression modeling study

    Directory of Open Access Journals (Sweden)

    Spengler John D

    2010-11-01

    Full Text Available Abstract Background There is growing concern in communities surrounding airports regarding the contribution of various emission sources (such as aircraft and ground support equipment to nearby ambient concentrations. We used extensive monitoring of nitrogen dioxide (NO2 in neighborhoods surrounding T.F. Green Airport in Warwick, RI, and land-use regression (LUR modeling techniques to determine the impact of proximity to the airport and local traffic on these concentrations. Methods Palmes diffusion tube samplers were deployed along the airport's fence line and within surrounding neighborhoods for one to two weeks. In total, 644 measurements were collected over three sampling campaigns (October 2007, March 2008 and June 2008 and each sampling location was geocoded. GIS-based variables were created as proxies for local traffic and airport activity. A forward stepwise regression methodology was employed to create general linear models (GLMs of NO2 variability near the airport. The effect of local meteorology on associations with GIS-based variables was also explored. Results Higher concentrations of NO2 were seen near the airport terminal, entrance roads to the terminal, and near major roads, with qualitatively consistent spatial patterns between seasons. In our final multivariate model (R2 = 0.32, the local influences of highways and arterial/collector roads were statistically significant, as were local traffic density and distance to the airport terminal (all p Conclusion Our study has shown that there are clear local variations in NO2 in the neighborhoods that surround an urban airport, which are spatially consistent across seasons. LUR modeling demonstrated a strong influence of local traffic, except the smallest roads that predominate in residential areas, as well as proximity to the airport terminal.

  3. On the Ratio of Sulfur Dioxide to Nitrogen Oxides as an Indicator of Air Pollution Sources.

    Science.gov (United States)

    Nirel, Ronit; Dayan, Uri

    2001-07-01

    The ratio of sulfur dioxide to nitrogen oxides (RSN = SO2/NOx) is one indicator of air pollution sources. The role of this ratio in source attribution is illustrated here for the Ashdod area, located in the southern coastal plain of Israel. The main sources of pollution in the area are the tall stacks of the Eshkol power plant, the stacks of oil refineries, and areal sources (stationary and mobile). The factors that affect RSN are studied using four regression models: a binary regression tree in original scale, a tree in logarithmic scale, a data partition produced by a combination of the two trees, and a linear regression model. All models have similar relative prediction error, with the combined partition best highlighting the sources of variability in RSN: (a) very low values (interquartile range of [0.12, 0.48]) are associated with traffic, (b) low values ([0.43, 1.00]) are attributed to the power plant and to daytime emissions of local industry, (c) medium values ([0.74, 1.90]) are associated with local industry emissions during cooler hours of the day and refinery emissions mainly on slow wind episodes, and (d) high values ([1.07, 4.30]) are attributed to refinery emissions during moderate to fast wind episodes. Analysis of the number of episodes of increased concentrations indicates that, during 1996 and 1997, about 42% of SO2 episodes are attributable to the power plant and 33% to the refineries. Increased-NOx episodes are mainly contributed by traffic (91%) and power plant (4.5%) emissions.

  4. Sources of variation for indoor nitrogen dioxide in rural residences of Ethiopia

    Directory of Open Access Journals (Sweden)

    Mekonen Eyassu

    2009-11-01

    Full Text Available Abstract Background Unprocessed biomass fuel is the primary source of indoor air pollution (IAP in developing countries. The use of biomass fuel has been linked with acute respiratory infections. This study assesses sources of variations associated with the level of indoor nitrogen dioxide (NO2. Materials and methods This study examines household factors affecting the level of indoor pollution by measuring NO2. Repeated measurements of NO2 were made using a passive diffusive sampler. A Saltzman colorimetric method using a spectrometer calibrated at 540 nm was employed to analyze the mass of NO2 on the collection filter that was then subjected to a mass transfer equation to calculate the level of NO2 for the 24 hours of sampling duration. Structured questionnaire was used to collect data on fuel use characteristics. Data entry and cleaning was done in EPI INFO version 6.04, while data was analyzed using SPSS version 15.0. Analysis of variance, multiple linear regression and linear mixed model were used to isolate determining factors contributing to the variation of NO2 concentration. Results A total of 17,215 air samples were fully analyzed during the study period. Wood and crop were principal source of household energy. Biomass fuel characteristics were strongly related to indoor NO2 concentration in one-way analysis of variance. There was variation in repeated measurements of indoor NO2 over time. In a linear mixed model regression analysis, highland setting, wet season, cooking, use of fire events at least twice a day, frequency of cooked food items, and interaction between ecology and season were predictors of indoor NO2 concentration. The volume of the housing unit and the presence of kitchen showed little relevance in the level of NO2 concentration. Conclusion Agro-ecology, season, purpose of fire events, frequency of fire activities, frequency of cooking and physical conditions of housing are predictors of NO2 concentration. Improved

  5. Growth responses of plants to various concentrations of nitrogen dioxide. [Helianthus annuus L. ; Zea mays L

    Energy Technology Data Exchange (ETDEWEB)

    Okano, K.; Totsuka, T.; Fukuzawa, T.; Tazaki, T.

    1985-01-01

    Sunflower Helianthus annuus L. and maize Zea mays L. plants in the vegetative phase were exposed to nitrogen dioxide (NO2) at 0.0 (control), 0.2, 0.5 and 1.0 ppm ( l liter ) for 2 weeks. The growth responses of the plants to NO2 were examined by the techniques of growth analysis. The sunflower plant was more susceptible to NO2 than the maize plant. Exposure to NO2 at 0.2 ppm slightly stimulated the growth of the sunflower plants. The net assimilation rate (NAR) was also significantly increased when the plants were exposed to 0.2 ppm NO2. Exposures to NO2 at 0.5 or more significantly reduced the dry weight of the sunflower plant. Of the component parts, the roots and stems were severely affected, while the leaves were less affected. This resulted in an elevated shoot/root ratio. The net assimilation rate of both species was reduced by the exposures to NO2 at 0.5 ppm or more, while, in contrast, the leaf area ratio (LAR) was increased. The relative growth rate (RGR), the product of the NAR and the LAR, was therefore less affected by NO2. The increase in the LAR was overwhelmingly the result of an increase in the leaf weight ratio (LWR). These results imply that a reduction in photosynthetic efficiency induced by NO2 could be, in part, compensated for by an increase in assimilatory area, suggesting an adaptive growth response of the plants to air pollutant stresses.

  6. Combined nitrogen oxides/sulfur dioxide control in dry scrubber systems

    Energy Technology Data Exchange (ETDEWEB)

    Harkness, J. B.L.; Gorski, A. J.; Huang, H. S.

    1989-02-01

    Argonne National Laboratory (ANL) is investigating alternative control concepts that involve modifying existing SO{sub 2}-removal processes and sorbents, with the objective of achieving simultaneous removal of nitrogen oxides (NO{sub x}) and sulfur dioxide (SO{sub 2}). Laboratory-scale research conducted using a fixed-bed reactor and a spray-dryer/fabric-filter system has been paralleled by field tests at ANL's commercial-scale (20-MW electric equivalent) dry scrubber. In the fixed-bed experiments, a range of chemical reagents was surveyed, and the best-performing additives were studied in detail. Sodium chloride, sodium bisulfite, sodium hydroxide, and Fe(II)*EDTA were found to increase both NO{sub x} and SO{sub 2} removals; the additives did not appear to increase NO{sub x} removal directly, but they interacted strongly with the other primary variables to improve sorbent performance. The laboratory spray-dryer system was used to study the effects on combined NO{sub x}/SO{sub 2} removal of the best-performing fixed-bed additives and certain process modifications. The tests showed that sodium chloride increased NO{sub x} removal at all temperatures; sodium bisulfite was generally less effective, and calcium chloride was effective only at 65{degree}C. Up to 80{degree}C, all three additives significantly improved SO{sub 2} removal, but improvement ceased at higher temperatures. This report discusses the experimental results in terms of the effects the additives and principal process variables had on NO{sub x} and SO{sub 2} removals and the mechanistic implications. 14 refs., 74 figs., 33 tabs.

  7. Pulmonary arachidonic acid metabolism following acute exposures to ozone and nitrogen dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Schlesinger, R.B.; Driscoll, K.E.; Gunnison, A.F.; Zelikoff, J.T. (New York Univ. Medical Center, NY (USA))

    1990-12-01

    Ozone (O{sub 3}) and nitrogen dioxide (NO{sub 2}) are common air pollutants, and exposure to these gases has been shown to affect pulmonary physiology, biochemistry, and structure. This study examined their ability to modulate arachidonic acid metabolites (eicosanoids) in the lungs. Rabbits were exposed for 2 h to O{sub 3} at 0.1, 0.3, or 1 ppm; NO{sub 2} at 1, 3, or 10 ppm; or to a mixture of 0.3 ppm O{sub 3} and 3 ppm NO{sub 2}. Groups of animals sacrificed either immediately or 24 h after each exposure underwent broncho-pulmonary lavage. Selected eicosanoids were assessed in lavage fluid by radioimmunoassay. Increases in prostaglandins E2 (PGE2) and F2 alpha (PGF2 alpha) were found immediately after exposure to 1 ppm O{sub 3}. Exposure to 10 ppm NO{sub 2} resulted in a depression of 6-keto-PGF1 alpha, while thromboxane B2 (TxB2) was elevated after exposure to 1 ppm NO{sub 2} and depressed following 3 and 10 ppm. The O{sub 3}/NO{sub 2} mixture resulted in synergistic increases in PGE2 and PGF2 alpha, with the response appearing to be driven by O{sub 3}. This study has demonstrated that acute exposure to either O{sub 3} or NO{sub 2} can alter pulmonary arachidonic acid metabolism and that the responses to these oxidants differ, both quantitatively and qualitatively.

  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. Citizen science identifies the effects of nitrogen dioxide and other environmental drivers on tar spot of sycamore.

    Science.gov (United States)

    Gosling, Laura; Ashmore, Mike; Sparks, Tim; Bell, Nigel

    2016-07-01

    Elevated sulphur dioxide (SO2) concentrations were the major cause of the absence of symptoms of tar spot (Rhytisma acerinum) of sycamore (Acer pseudoplatanus), in urban areas in the 1970s. The subsequent large decline in SO2 concentrations has not always been accompanied by increased tar spot symptoms, for reasons that have remained unresolved. We used a large citizen science survey, providing over 1000 records across England, to test two competing hypotheses proposed in earlier studies. We were able to demonstrate the validity of both hypotheses; tar spot symptoms were reduced where there were fewer fallen leaves as a source of inoculum, and elevated nitrogen dioxide concentrations reduced tar spot symptoms above a threshold concentration of about 20 μg m(-3). Symptom severity was also lower at sites with higher temperature and lower rainfall. Our findings demonstrate the power of citizen science to resolve competing hypotheses about the impacts of air pollution and other environmental drivers.

  10. Simulating reactive nitrogen, carbon monoxide, and ozone in California during ARCTAS-CARB 2008 with high wildfire activity

    Science.gov (United States)

    Cai, Chenxia; Kulkarni, Sarika; Zhao, Zhan; Kaduwela, Ajith P.; Avise, Jeremy C.; DaMassa, John A.; Singh, Hanwant B.; Weinheimer, Andrew J.; Cohen, Ronald C.; Diskin, Glenn S.; Wennberg, Paul; Dibb, Jack E.; Huey, Greg; Wisthaler, Armin; Jimenez, Jose L.; Cubison, Michael J.

    2016-03-01

    Predictions of O3, CO, total NOy and individual NOy species (NO, NO2, HNO3, PAN, alkyl nitrates and aerosol nitrate) from a fine resolution regional air quality modeling system for the South Coast Air Basin (SoCAB) and San Joaquin Valley Air Basin (SJVAB) of California are presented and evaluated for the 2008 ARCTAS-CARB campaign. The measurements of the chemical compounds from the fire plumes during the field campaign allow for the evaluation of the model's ability to simulate fire-influenced air masses as well. In general, the model successfully simulated the broad spatial distribution of chemical compounds in both air basins as well as the variation within the basins. Using inventories that reflect 2008 emissions levels, the model performed well in simulating NOx (NO + NO2) in SoCAB. Therefore, the under prediction of O3 over these areas is more likely caused by uncertainties with the VOC emissions, chemistry, or discrepancies in the meteorology. The model did not capture the relatively high levels of O3, and some reactive nitrogen species that were measured off shore of the SoCAB, indicating potential missing sources or the transport from on shore to off shore was not successfully captured. In SJVAB, the model had good performance in simulating different chemical compounds in the Fresno and Arvin areas. However, enhanced concentrations of O3, NOx, HNO3 and PAN near dairy farms were significantly underestimated in the model. Negative biases also exist for O3 and HNO3 near oil fields, suggesting larger uncertainties associated with these emission sources. While the model simulated the total NOy mixing ratios reasonably well, the prediction for partitioning between individual compounds showed larger uncertainties in the model simulation. Although the fire emissions inventory was updated to include the latest emissions estimates and speciation profiles, our model shows limited improvement in simulating the enhancement of O3, CO, and PAN under fire impact as

  11. Partial oxidation of methane to methanol with nitrogen dioxide in dielectric barrier discharge plasma: experimental and molecular modeling

    Science.gov (United States)

    Indarto, Antonius

    2016-04-01

    Non-catalytic conversion of methane (CH4) and nitrogen dioxide (NO2) into methanol (CH3OH) has been conducted and presented in this paper. Experiments were carried out using dielectric barrier discharge as the reaction medium in atmospheric pressure and temperature conditions. High yield production of methanol was achieved (18-20% mol) by single-stage plasma reaction with maximum selectivity of 32% mol. Compared to other oxidants, such as O2, the presence of NO2 in the plasma reaction resulted in higher methanol selectivity. For better understanding of the reactions, density functional theory calculations were also performed and discussed.

  12. An ex post cost-benefit analysis of the nitrogen dioxide air pollution control program in Tokyo

    Energy Technology Data Exchange (ETDEWEB)

    Voorhees, A.S.; Araki, S.; Sakai, R.; Sato, H. [University of Tokyo, Tokyo (Japan). Dept. of Public Health and Occupational Medicine

    2000-03-01

    The benefits and costs of past nitrogen dioxide (NO{sub 2}) control policies were calculated for Tokyo, Japan, using environmental, economic, political, demographic, and medical data from 1973 to 1994. The benefits of NO{sub 2} control were estimated as medical expenses and lost work time due to hypothetical no-control air concentrations of NO{sub 2}. Direct costs were calculated as annualized capital expenditures and 1 year's operating costs for regulated industries plus governmental agency expense. 46 refs., 8 figs., 6 tabs.

  13. EOS7C Version 1.0: TOUGH2 Module for Carbon Dioxide or Nitrogen in Natural Gas (Methane) Reservoirs

    OpenAIRE

    Oldenburg, Curtis M.; Moridis, George J.; Spycher, Nicholas; Pruess, Karsten

    2004-01-01

    EOS7C is a TOUGH2 module for multicomponent gas mixtures in the systems methanecarbon dioxide (CH4-CO2) or methane-nitrogen (CH4-N2) with or without an aqueous phase and H2O vapor. EOS7C uses a cubic equation of state and an accurate solubility formulation along with a multiphase Darcy s Law to model flow and transport of gas and aqueous phase mixtures over a wide range of pressures and temperatures appropriate to subsurface geologic carbon sequestration sites and natural gas reservoirs....

  14. [Methodology of the description of atmospheric air pollution by nitrogen dioxide by land use regression method in Ekaterinburg].

    Science.gov (United States)

    Antropov, K M; Varaksin, A N

    2013-01-01

    This paper provides the description of Land Use Regression (LUR) modeling and the result of its application in the study of nitrogen dioxide air pollution in Ekaterinburg. The paper describes the difficulties of the modeling for air pollution caused by motor vehicles exhaust, and the ways to address these challenges. To create LUR model of the NO2 air pollution in Ekaterinburg, concentrations of NO2 were measured, data on factors affecting air pollution were collected, a statistical analysis of the data were held. A statistical model of NO2 air pollution (coefficient of determination R2 = 0.70) and a map of pollution were created.

  15. Current emission trends for nitrogen oxides, sulfur dioxide, and volatile organic compounds by month and state: Methodology and results

    Energy Technology Data Exchange (ETDEWEB)

    Kohout, E.J.; Miller, D.J.; Nieves, L.A.; Rothman, D.S.; Saricks, C.L.; Stodolsky, F.; Hanson, D.A.

    1990-08-01

    This report presents estimates of monthly sulfur dioxide (SO{sub 2}), nitrogen oxides (NO{sub x}), and nonmethane voltatile organic compound (VOC) emissions by sector, region, and state in the contiguous United States for the years 1975 through 1988. This work has been funded as part of the National Acid Precipitation Assessment Program`s Emissions and Controls Task Group by the US Department of Energy (DOE) Office of Fossil Energy (FE). The DOE project officer is Edward C. Trexler, DOE/FE Office of Planning and Environment.

  16. Current emission trends for nitrogen oxides, sulfur dioxide, and volatile organic compounds by month and state: Methodology and results

    Energy Technology Data Exchange (ETDEWEB)

    Kohout, E.J.; Miller, D.J.; Nieves, L.A.; Rothman, D.S.; Saricks, C.L.; Stodolsky, F.; Hanson, D.A.

    1990-08-01

    This report presents estimates of monthly sulfur dioxide (SO{sub 2}), nitrogen oxides (NO{sub x}), and nonmethane voltatile organic compound (VOC) emissions by sector, region, and state in the contiguous United States for the years 1975 through 1988. This work has been funded as part of the National Acid Precipitation Assessment Program's Emissions and Controls Task Group by the US Department of Energy (DOE) Office of Fossil Energy (FE). The DOE project officer is Edward C. Trexler, DOE/FE Office of Planning and Environment.

  17. Rapid growth in nitrogen dioxide pollution over Western China, 2005–2013

    Directory of Open Access Journals (Sweden)

    Y.-Z. Cui

    2015-12-01

    Full Text Available Western China has experienced rapid industrialization and urbanization since the implementation of the National Western Development Strategies (the "Go West" movement in 1999. This transition has affected the spatial and temporal characteristics of nitrogen dioxide (NO2 pollution. In this study, we analyze the trends and variability of tropospheric NO2 vertical column densities (VCDs from 2005 to 2013 over Western China, based on a wavelet analysis on monthly mean NO2 data derived from the Ozone Monitoring Instrument (OMI measurements. We focus on the anthropogenic NO2 by subtracting region-specific "background" values dominated by natural sources. We find significant NO2 growth over Western China between 2005 and 2013 (8.6 ± 0.9 % yr−1 on average, relative to 2005, with the largest increments (15 % yr−1 or more over parts of several city clusters. The NO2 pollution in most provincial regions rose rapidly from 2005 to 2011 but stabilized or declined afterwards. The NO2 trends were driven mainly by changes in anthropogenic emissions, as confirmed by a nested GEOS-Chem model simulation and a comparison with Chinese official emission statistics. The rate of NO2 growth during 2005–2013 reaches 11.3 ± 1.0 % yr−1 over Northwestern China, exceeding the rates over Southwestern China (5.9 ± 0.6 % yr−1 and the three well-known polluted regions in the east (5.3 ± 0.8 % yr−1 over Beijing–Tianjin–Hebei, 4.0 ± 0.6 % yr−1} over the Yangtze River Delta, and −3.3 ± 0.3 % yr−1 over the Pearl River Delta. Additional socioeconomic analyses suggest that the rapid NO2 growth in Northwestern China is likely related to the fast developing resource- and pollution-intensive industries along with the "Go West" movement as well as relatively weak emission controls. Further efforts should be made to alleviate NOx pollution to achieve sustainable development in Western China.

  18. Rapid growth in nitrogen dioxide pollution over Western China, 2005-2013

    Science.gov (United States)

    Cui, Yuanzheng; Lin, Jintai; Song, Chunqiao; Liu, Mengyao; Yan, Yingying; Xu, Yuan; Huang, Bo

    2016-05-01

    Western China has experienced rapid industrialization and urbanization since the implementation of the National Western Development Strategies (the "Go West" movement) in 1999. This transition has affected the spatial and temporal characteristics of nitrogen dioxide (NO2) pollution. In this study, we analyze the trends and variability of tropospheric NO2 vertical column densities (VCDs) from 2005 to 2013 over Western China, based on a wavelet analysis on monthly mean NO2 data derived from the Ozone Monitoring Instrument (OMI) measurements. We focus on the anthropogenic NO2 by subtracting region-specific "background" values dominated by natural sources. After removing the background influences, we find significant anthropogenic NO2 growth over Western China between 2005 and 2013 (8.6 ± 0.9 % yr-1 on average, relative to 2005), with the largest increments (15 % yr-1 or more) over parts of several city clusters. The NO2 pollution in most provincial-level regions rose rapidly from 2005 to 2011 but stabilized or declined afterwards. The NO2 trends were driven mainly by changes in anthropogenic emissions, as confirmed by a nested GEOS-Chem model simulation and a comparison with Chinese official emission statistics. The rate of NO2 growth during 2005-2013 reaches 11.3 ± 1.0 % yr-1 over Northwestern China, exceeding the rates over Southwestern China (5.9 ± 0.6 % yr-1) and the three well-known polluted regions in the east (5.3 ± 0.8 % yr-1 over Beijing-Tianjin-Hebei, 4.0 ± 0.6 % yr-1 over the Yangtze River Delta, and -3.3 ± 0.3 % yr-1 over the Pearl River Delta). Subsequent socioeconomic analyses suggest that the rapid NO2 growth over Northwestern China is likely related to the fast developing resource- and pollution-intensive industries along with the "Go West" movement as well as relatively weak emission controls. Further efforts should be made to alleviate NOx pollution to achieve sustainable development in Western China.

  19. Improved spectral fitting of nitrogen dioxide from OMI in the 405-465 nm window

    Science.gov (United States)

    van Geffen, J. H. G. M.; Boersma, K. F.; Van Roozendael, M.; Hendrick, F.; Mahieu, E.; De Smedt, I.; Sneep, M.; Veefkind, J. P.

    2015-04-01

    An improved nitrogen dioxide (NO2) slant column density retrieval for the Ozone Monitoring Instrument (OMI) in the 405-465 nm spectral region is presented. Since the launch of OMI on board NASA's EOS-Aura satellite in 2004, differential optical absorption spectroscopy (DOAS) retrievals of NO2 slant column densities have been the starting point for the KNMI DOMINO and NASA SP NO2 vertical column data as well as the OMI NO2 data of some other institutes. However, recent intercomparisons between NO2 retrievals from OMI and other UV/Vis and limb spectrometers, as well as ground-based measurements, suggest that OMI stratospheric NO2 is biased high. This study revises and, for the first time, fully documents the OMI NO2 retrieval in detail. The representation of the OMI slit function to convolve high-resolution reference spectra onto the relevant spectral grid is improved. The window used for the wavelength calibration is optimised, leading to much-reduced fitting errors. Ozone and water vapour spectra used in the fit are updated, reflecting the recently improved knowledge of their absorption cross section in the literature. The improved spectral fit also accounts for absorption by the O2-O2 collision complex and by liquid water over clear-water areas. The main changes in the improved spectral fitting result from the updates related to the wavelength calibration: the RMS error of the fit is reduced by 23% and the NO2 slant column by 0.85 × 1015 molec cm-2, independent of latitude, solar zenith angle and NO2 value. Including O2-O2 and liquid water absorption and updating the O3 and water vapour cross-section spectra further reduces NO2 slant columns on average by 0.35 × 1015 molec cm-2, accompanied by a further 9% reduction in the RMS error of the fit. The improved OMI NO2 slant columns are consistent with independent NO2 retrievals from other instruments to within a range that can be explained by photochemically driven diurnal increases in stratospheric NO2 and by

  20. Mass transfer phenomena of gaseous hydrocarbons and nitrogen dioxide across gas-inorganic pigments boundaries

    Science.gov (United States)

    Birbatakou, S.; Pagopoulou, I.; Kalantzopoulos, A.; Roubani-Kalantzopoulou, F.

    1998-11-01

    Reversed-flow gas chromatography was used to study the kinetics of the action of five hydrocarbons namely, ethane, ethene, ethyne, propene and butene and of the nitrogen dioxide, on three known and widely used pigments, the white one TiO2, and the yellows CdS and PbCrO4. The calculation of kinetic parameters and mass transfer coefficients is based on an experimental adsorption isotherm. All these calculations are based on a non linear adsorption isotherm model as it is well accepted that the linear one is inadequate for inorganic substances like these mentioned in this work. The inadequacy is mainly attributed to the non-uniformity of the solid surface. Five physicochemical parameters have been obtained for each of the twenty heterogeneous reactions studied. With these systematic experiments under conditions which are similar to the atmospheric ones, an extrapolation of the results obtained to “real" atmospheres with a high degree of confidence is possible. Some of the calculations were based on the linear model for comparison. La cinétique de la réaction de cinq hydrocarbures (éthane, éthylène, acétylène, propène, boutène) et du dioxyde d'azote avec trois pigments (le blanc de TiO2 et les jaunes de CdS et PbCrO4) a été étudiée par chromatographie en phase gazeuse a flux inversé. Le calcul des paramètres cinétiques et des coefficients de transfert de masse a été effectué à partir des isothermes d'adsorption expérimentales en faisant l'hypothèse d`un modèle d'adsorption non-linéaire, qui résulte de la non-uniformité de la surface. Cinq paramètres physico-chimiques ont été obténus pour chacune des vingt réaction hétérogènes étudiées. À partir de ces résultats obténus dans des conditions similaires aux conditions atmosphériques, l'extrapolation à des atmosphères réelles paraît possible avec une bonne confiance. Quelques calculs ont été effectués avec un modèle linéaire pour comparaison.

  1. Spatiotemporal patterns of correlation between atmospheric nitrogen dioxide and aerosols over South Asia

    Science.gov (United States)

    ul-Haq, Zia; Tariq, Salman; Ali, Muhammad

    2016-10-01

    An accurate knowledge is needed on the complex relation between atmospheric trace gasses and aerosol variability and their sources to explain trace gases-aerosols-climate interaction and next-generation modeling of climate change and air quality. In this regard, we have used tropospheric Nitrogen Dioxide (NO2), Aerosol Optical Depth (AOD) and Angstrom Exponent (AE) obtained from satellite-based Ozone Monitoring Instrument (OMI)/Aura and Moderate-Resolution Imaging Spectroradiometer (MODIS)/Aqua over South Asia. NO2-AOD correlation with coefficient r = 0.49 is determined over the landmass of South Asia during 2005-2015. Yearly mean NO2-AOD correlation over South Asia shows large variations ranging from r = 0.32 to 0.86 in 2008 and 2009, respectively. The highest correlation (r = 0.66) is seen over eastern regions of Bangladesh and India, as well as adjoining areas of western Myanmar mostly linked to anthropogenic activities. A significant correlation (r = 0.59) associated with natural causes is found over some parts of Sistan region, located at the borders of Iran, Pakistan and Afghanistan, and adjoining territory. We find significant positive correlations for monsoon and post-monsoon seasons with r = 0.50 and r = 0.61, respectively. A linear regression on the annual correlation coefficients data suggests that NO2-AOD correlation is strengthening with an increase of 12.9% over South Asia during the study period. The spatial distribution of data slopes reveals positive trends in NO2-AOD correlation over megacities Lahore, Dhaka, Mumbai and Kolkata linked to growing anthropogenic activities. Singrauli city (India) has the highest correlation (r = 0.62) and 35% increase in correlation coefficient value per year. A negative correlation is observed for megacity Karachi (r = -0.37) suggesting the non-commonality of NO2 and aerosols emission sources. AE has also been used to discuss its correlation with NO2 over the areas with dominance of fine-mode aerosols.

  2. 4D-Var Assimilation of MIPAS chemical observations: ozone and nitrogen dioxide analyses

    Directory of Open Access Journals (Sweden)

    Q. Errera

    2008-04-01

    Full Text Available This paper discusses the global analyses of stratospheric ozone (O3 and nitrogen dioxide (NO2 obtained by the Belgian Assimilation System for Chemical Observations from Envisat (BASCOE. Based on a chemistry transport model (CTM and the 4-dimensional variational (4D-Var method, BASCOE has assimilated chemical observations of O3, NO2, HNO3, N2O, CH4 and H2O, made between July 2002 and March 2004 by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS onboard the European Space Agency (ESA Environment Satellite (ENVISAT. This corresponds to the entire period during which MIPAS was operating at its nominal resolution.

    Our analyses are evaluated against assimilated MIPAS data and independent HALOE (HALogen Occultation Experiment and POAM-III (Polar Ozone and Aerosol Measurement satellite data. A good agreement is generally found between the analyses and these datasets, in both cases within the estimated error bars of the observations. The benefit of data assimilation is also evaluated using a BASCOE free model run. For O3, the gain from the assimilation is significant during ozone hole conditions, and in the lower stratosphere. Elsewhere, the free model run is within the MIPAS uncertainties and the assimilation does not provide significant improvement. For NO2, the gain from the assimilation is realized through most of the stratosphere. Using the BASCOE analyses, we estimate the differences between MIPAS data and independent data from HALOE and POAM-III, and find results close to those obtained by classical validation methods involving only direct measurement-to-measurement comparisons. Our results extend and reinforce previous MIPAS data validation efforts by taking account of a much larger variety of atmospheric states and measurement conditions.

    This study discusses possible further developments of the

  3. Broadband cavity enhanced spectroscopy in the ultraviolet spectral region for measurements of nitrogen dioxide and formaldehyde

    Science.gov (United States)

    Washenfelder, R. A.; Attwood, A. R.; Flores, J. M.; Rudich, Y.; Brown, S. S.

    2015-09-01

    Formaldehyde (CH2O) is the most abundant aldehyde in the atmosphere, and strongly affects photochemistry through its photolysis. We describe simultaneous measurements of CH2O and nitrogen dioxide (NO2) using broadband cavity enhanced spectroscopy in the ultraviolet spectral region. The light source consists of a continuous-wave diode laser focused into a Xenon bulb to produce a plasma that emits high-intensity, broadband light. The plasma discharge is optically filtered and coupled into a 1 m optical cavity. The reflectivity of the cavity mirrors is 0.99933 ± 0.00003 (670 ppm loss) at 338 nm, as determined from the known Rayleigh scattering of He and zero air. This mirror reflectivity corresponds to an effective path length of 1.49 km within the 1 m cell. We measure the cavity output over the 315-350 nm spectral region using a grating monochromator and charge-coupled device (CCD) array detector. We use published reference spectra with spectral fitting software to simultaneously retrieve CH2O and NO2 concentrations. Independent measurements of NO2 standard additions by broadband cavity enhanced spectroscopy and cavity ringdown spectroscopy agree within 2 % (slope for linear fit = 0.98 ± 0.03 with r2 = 0.998). Standard additions of CH2O measured by broadband cavity enhanced spectroscopy and calculated based on flow dilution are also well-correlated, with r2 = 0.9998. During constant, mixed additions of NO2 and CH2O, the 30 s measurement precisions (1σ) of the current configuration were 140 and 210 pptv, respectively. The current 1-min detection limit for extinction measurements at 315-350 nm provides sufficient sensitivity for measurement of trace gases in laboratory experiments and ground-based field experiments. Additionally, the instrument provides highly accurate, spectroscopically-based trace gas detection that may complement higher precision techniques based on non-absolute detection methods. In addition to trace gases, this approach will be appropriate for

  4. Effect of nitrogen dioxide, ozone, and peroxyacetyl nitrate on metabolic and pulmonary function

    Energy Technology Data Exchange (ETDEWEB)

    Drechsler-Parks, D.M. (Univ. of California, Santa Barbara (USA))

    1987-04-01

    The metabolic and pulmonary function responses were investigated in 32 non-smoking men and women (8 men and 8 women 18-26 years of age, and 8 men and 8 women 51-76 years of age) who were exposed for 2 hours to each of 8 conditions: (1) filtered air (FA), (2) 0.13 ppm peroxyacetyl nitrate (PAN), (3) 0.45 ppm ozone (O3), (4) 0.60 ppm nitrogen dioxide (NO2), (5) 0.13 ppm PAN + 0.45 ppm O3 (PAN/O3), (6) 0.13 ppm PAN + 0.60 ppm NO2 (PAN/NO2), (7) 0.60 ppm NO2 + 0.45 ppm O3 (NO2/O3), and (8) 0.13 ppm PAN + 0.60 ppm NO2 + 0.45 ppm O3 (PAN/NO2/O3). The subjects alternated 20-min periods of rest (n = 3) and cycle ergometer exercise (n = 3) at a work load predetermined to elicit a ventilatory minute volume (VE) of approximately 25 L/min (BTPS). Functional residual capacity (FRC) was determined pre- and post-exposure. Forced vital capacity (FVC) was determined before and after exposure, and 5 min after each exercise period. Heart rate was monitored throughout each exposure, and VE was measured during the last 2 min of each exercise period. Exposure to FA, PAN, NO2, and PAN/NO2 had no effect on any measure of pulmonary or metabolic function. Ozone was primarily responsible for the pulmonary function effects observed. There was no significant difference between the responses to O3 exposure and the responses to the three O3 mixtures, indicating no interactions between the pollutants. The results suggest that women may be somewhat more responsive to O3 exposure than men, and that older people (51-76 years of age) may be less responsive to O3 than younger people (18-26 years of age).

  5. Acute effects of low-level sulphur dioxide and nitrogen dioxide exposures on the respiratory tract of susceptible subjects in cold environments

    Energy Technology Data Exchange (ETDEWEB)

    Salonen, R.O.; Randell, J.T.; Haelinen, A.I.; Pennanen, A.S. [National Public Health Inst., Kuopio (Finland). Div. of Environmental Health; Kosma, V.M. [Kuopio Univ. (Finland). Dept. of Pathology; Pekkarinen, H. [Kuopio Univ. (Finland). Dept. of Physiology; Ruuskanen, J. [Kuopio Univ. (Finland). Dept. of Environmental Sciences; Tukiainen, H. [Kuopio Univ. (Finland). Dept. of Pulmonary Diseases

    1995-12-31

    Several recent epidemiological studies from Finland have suggested that sulphur dioxide (SO{sub 2}) and nitrogen dioxide (NO{sub 2}) cause adverse health effects in susceptible population groups, such as children and asthmatic patients, at much smaller concentrations than the present guideline values of the World Health Organization. One possible explanation of these findings is that the relatively long winter-time increases the sensitivity of the respiratory tract to irritant pollutants. This hypothesis is supported by experimental human and animal studies, which have shown obstruction and inflammatory changes in the conducting airways after ventilation of cold and dry air. Asthmatic patients are much more sensitive than healthy subjects to the irritating effects of cold and dry air and of air pollutants. The airways of many non-asthmatic a topic subjects are also sensitive to cold air, but these subjects are poorly defined as a potential susceptible population group to air pollutants. The aims of this project are: (1) to construct experimental human and animal facilities and protocols for short-term studies on SO{sub 2} and NO{sub 2} exposures at subfreezing temperatures, (2) to apply advanced lung function methodologies and symptom assessment for characterisation of short-term respiratory responses of asthmatic and a topic subjects to these exposures, (3) to apply well-established pulmonary physiological, cytological and morphological methods for characterisation of short-term responses to and mechanisms of these exposures in the guinea-pig lower airways. (author)

  6. Responses of two summer annuals to interactions of atmospheric carbon dioxide and soil nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, R.B.

    1987-01-01

    The competitive relationship between Chenopodium album L. (C{sub 3}) and Amaranthus hybridus L. (C{sub 4}) was investigated in two atmospheric CO{sub 2} levels and tow soil nitrogen levels. Biomass and leaf surface area of Amaranthus plants did not respond to CO{sub 2} enrichment. Only in high nitrogen did Chenopodium plants respond to increased CO{sub 2} with greater biomass and leaf surface area. Nitrogen use efficiency (NUE) was higher in Amaranthus than in Chenopodium in all treatments except for the high-nitrogen high-CO{sub 2} treatment. Under conditions of high nitrogen and low CO{sub 2}, Chenopodium was a poor competitor, but competition favored Chenopodium in high nitrogen and high CO{sub 2}. In low nitrogen and high CO{sub 2}, competition favored Chenopodium on a dry weight basis, but favored Amaranthus on a seed weight basis, reflecting early senescence of Chenopodium. In low nitrogen and high CO{sub 2}, competition favored Amaranthus on a dry weight basis, but favored Chenopodium on a seed weight basis. Physiological aspects of the growth of Chenopodium and Amaranthus were studied. Acclimation to elevated CO{sub 2} occurred at the enzyme level in Chenopodium. Under conditions of high nitrogen and no competition, individual Chenopodium plants responded to elevated CO{sub 2} with greater biomass, leaf surface area, and maximum net photosynthetic rates. In high nitrogen, leaf nitrogen, soluble protein, and RuBP carboxylase activity of Chenopodium decreased and NUE increased when grown in elevated CO{sub 2}. In low nitrogen without competition, Chenopodium showed no significant response to CO{sub 2} enrichment. Amarantus grown in high and low nitrogen without competition showed no significant changes in leaf nitrogen, soluble protein, carboxylase activity, chlorophyll, or NUE of in response to CO{sub 2} enrichment.

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

    Science.gov (United States)

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

    2017-01-23

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

  8. Spatially resolved measurements of nitrogen dioxide in an urban environment using concurrent multi-axis differential optical absorption spectroscopy

    Directory of Open Access Journals (Sweden)

    R. J. Leigh

    2007-09-01

    Full Text Available A novel system using the technique of concurrent multi-axis differential optical absorption spectroscopy system has been developed and applied to the measurement of nitrogen dioxide in an urban environment. Using five fixed telescopes, slant columns of nitrogen dioxide, ozone, water vapour, and the oxygen dimer, O4, are simultaneously retrieved in five vertically separated viewing directions. The application of this remote sensing technique in the urban environment is explored. Through the application of several simplifying assumptions a tropospheric concentration of NO2 is derived and compared with an urban background in-situ chemiluminescence detector. Trends derived from remote sensing and in-situ techniques show agreement to within 15 to 40% depending on conditions. Owing to the high time resolution of the measurements, the ability to image and quantify plumes within the urban environment is demonstrated. The CMAX-DOAS measurements provide a useful measure of overall NO2 concentrations on a city-wide scale.

  9. Nitrogen deposition effects on carbon dioxide and methane emissions from temperate peatland soils

    Energy Technology Data Exchange (ETDEWEB)

    Aerts, Rien; Caluwe, Hannie de [Utrecht Univ., Dept. of Plant Ecology and Evolutionary Biology, Utrecht (Norway)

    1999-04-01

    Northern peatlands are important sources of carbon dioxide and methane emissions to the atmosphere. Increased atmospheric N deposition may have a significant impact on the emission of these greenhouse gases. We studied CO{sub 2} and CH{sub 4} emissions from untreated peat soils from a eutrophic and a mesotrophic fen in a high N deposition area (the Netherlands) and from a mesotrophic fen in a low N deposition area (north-east Poland). In addition, we investigated the effects of N, P and glucose amendments on the emissions of CO{sub 2} and CH{sub 4} from these soils. Nitrogen availability (extractable NH{sub 4}) in untreated peat from the high N area was 2.5-7.5 times higher than in the low N area, whereas the pH was 0.9-1.7 units lower. Using 6-week laboratory incubations of peat columns, we found that mean dayly CO{sub 2} emission from untreated peat soils from the high N area was lower than that from the low N area. Both linear and multiple regression analysis showed that CO{sub 2} emission was positively related to soil pH (r{sup 2}=0.64). Additional N supply led to pH reduction and to lower CO{sub 2} emission, especially in the low N peat soils. Thus, increased atmospheric N deposition leads, probably as a result of soil acidification, to lower CO{sub 2} emission. Although glucose amendments resulted in increase CO{sub 2} and CH{sub 4} emission, we did not find evidence that this was caused by increase mineralization of native peat. Mean daily CH{sub 4}-C emission was about 1-2 orders of magnitude lower than mean daily CO{sub 2}-C emission. In the untreated peat soils from the high N eutrophic site, methane emission was higher than in the high N mesotrophic site and in the low N mesotrophic site. Linear regression analysis showed a positive relation between methane emission and soil fertility variables (r{sup 2}=0.42-0.55), whereas a multiple regression model revealed that methane emission was determined by N-related soil chemistry variable (r{sup 2

  10. The Second Cabauw Intercomparison Campaign for Nitrogen Dioxide Measuring Instruments — CINDI-2 — Overview

    Science.gov (United States)

    Apituley, Arnoud; van Roozendael, Michel; Hendrick, Francois; Kreher, Karin; Richter, Andreas; Wagner, Thomas; Friess, Udo; Participants, Cindi-2

    2017-04-01

    For the validation of space borne observations of NO2 and other trace gases from hyperspectral imagers, ground based instruments based on the MAXDOAS technique are an excellent choice, since they rely on similar retrieval techniques as the observations from orbit. In both cases, retrievals take into account the light path of scattered sunlight though the entire atmosphere. Since MAXDOAS instruments are relatively low cost and can be operated autonomously almost anywhere, they are credible candidates to form a world-wide ground based reference network for satellite observations. To ensure proper traceability of the MAXDOAS observations, a thorough intercomparison is mandatory. The Cabauw Experimental Site for Atmospheric Research (CESAR) site in centre of The Netherlands was the stage of the Cabauw Intercomparison of Nitrogen Dioxide Measuring Instruments (CINDI) in June-July 2009 and again for the second campaign, CINDI-2, in 2016. Cabauw was chosen because the flat terrain offered a free view of large parts of the horizon, needed to accommodate the viewing geometry of the MAXDOAS observations. The location is under influence of both clean as well as polluted airmasses. This gives a wide range of possible trace gas concentrations and mixtures. Furthermore, at CESAR a wide range of observations are routinely carried out that fulfil the requirement to provide the background necessary for unraveling the differences between the observations from different MAXDOAS instruments that can be quite diverse in design and data treatment. These observations include parameters needed to understand the light paths, i.e. in-situ aerosol observations of optical and microphysical properties, as well as vertical profiles of aerosol optical properties by (Raman) lidar. In addition, vertical profiles of NO2 could be measured during CINDI-2 using the unique NO2 sonde, and a NO2 lidar system. With the imminent launch of Sentinel-5 Precursor/TROPOMI, with a nadir pixelsize of 3.5 × 3

  11. Carbon dynamics in subtropical forest soil. Effects of atmospheric carbon dioxide enrichment and nitrogen addition

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Juxiu X.; Zhou, Guoyi Y.; Zhang, Deqiang Q.; Duan, Honglang L.; Deng, Qi; Zhao, Liang [Chinese Academy of Sciences, Guangzhou (China). South China Botanical Garden; Xu, Zhihong H. [Griffith Univ., Nathan, Queensland (Australia). Environmental Futures Centre and School of Biomolecular and Physical Sciences

    2010-06-15

    The levels of atmospheric carbon dioxide concentration ([CO{sub 2}]) are rapidly increasing. Understanding carbon (C) dynamics in soil is important for assessing the soil C sequestration potential under elevated [CO{sub 2}]. Nitrogen (N) is often regarded as a limiting factor in the soil C sequestration under future CO{sub 2} enrichment environment. However, few studies have been carried out to examine what would happen in the subtropical or tropical areas where the ambient N deposition is high. In this study, we used open-top chambers to study the effect of elevated atmospheric [CO{sub 2}] alone and together with N addition on the soil C dynamics in the first 4 years of the treatments applied in southern China. Materials and methods Above- and below-ground C input (tree biomass) into soil, soil respiration, soil organic C, and total N as well as dissolved organic C (DOC) were measured periodically in each of the open-top chambers. Soil samples were collected randomly in each chamber from each of the soil layers (0-20, 20-40, and 40-60 cm) using a standard soil sampling tube (2.5-cm inside diameter). Soil leachates were collected at the bottom of the chamber below-ground walls in stainless steel boxes. Results and discussion The highest above- and below-ground C input into soil was found in the high CO{sub 2} and high N treatment (CN), followed by the only high N treatment (N+), the only high CO{sub 2} treatment (C+), and then the control (CK) without any CO{sub 2} enrichment or N addition. DOC in the leachates was small for all the treatments. Export of DOC played a minor role in C cycling in our experiment. Generally, soil respiration rate in the chambers followed the order: CN treatment > C + treatment > N + treatment > the control. Except for the C+ treatment, there were no significant differences in soil total N among the CN treatment, N + treatment, and the control. Overall, soil organic C (SOC) was significantly affected by the treatments (p < 0.0001). SOC

  12. Synthesis of polybenzoxazine based nitrogen-rich porous carbons for carbon dioxide capture

    Science.gov (United States)

    Wan, Liu; Wang, Jianlong; Feng, Chong; Sun, Yahui; Li, Kaixi

    2015-04-01

    Nitrogen-rich porous carbons (NPCs) were synthesized from 1,5-dihydroxynaphthalene, urea, and formaldehyde based on benzoxazine chemistry by a soft-templating method with KOH chemical activation. They possess high surface areas of 856.8-1257.8 m2 g-1, a large pore volume of 0.15-0.65 cm3 g-1, tunable pore structure, high nitrogen content (5.21-5.32 wt%), and high char yields. The amount of the soft-templating agent F127 has multiple influences on the textural and chemical properties of the carbons, affecting the surface area and pore structure, impacting the compositions of nitrogen species and resulting in an improvement of the CO2 capture performance. At 1 bar, high CO2 uptake of 4.02 and 6.35 mmol g-1 at 25 and 0 °C was achieved for the sample NPC-2 with a molar ratio of F127 : urea = 0.010 : 1. This can be attributed to its well-developed micropore structure and abundant pyridinic nitrogen, pyrrolic nitrogen and pyridonic nitrogen functionalities. The sample NPC-2 also exhibits a remarkable selectivity for CO2/N2 separation and a fast adsorption/desorption rate and can be easily regenerated. This suggests that the polybenzoxazine-based NPCs are desirable for CO2 capture because of possessing a high micropore surface area, a large micropore volume, appropriate pore size distribution, and a large number of basic nitrogen functionalities.Nitrogen-rich porous carbons (NPCs) were synthesized from 1,5-dihydroxynaphthalene, urea, and formaldehyde based on benzoxazine chemistry by a soft-templating method with KOH chemical activation. They possess high surface areas of 856.8-1257.8 m2 g-1, a large pore volume of 0.15-0.65 cm3 g-1, tunable pore structure, high nitrogen content (5.21-5.32 wt%), and high char yields. The amount of the soft-templating agent F127 has multiple influences on the textural and chemical properties of the carbons, affecting the surface area and pore structure, impacting the compositions of nitrogen species and resulting in an improvement of the

  13. Studies on the effect of long-term exposure to nitrogen dioxide on serum and liver proteins level and enzyme activity in guinea pigs.

    Science.gov (United States)

    Drozdz, M; Kucharz, E; Ludyga, K; Molska-Drozda, T

    1976-01-01

    Forty male guinea pigs were exposed to nitrogen dioxide in a concentration of 2 mg/m3, 8 hours daily for a period of 180 days. Forty male animals were used as a control group. The following changes were found in intoxicated animals: the decrease of total protein and seromucoid concentration in blood serum and the decrease of total protein, perchloric acid-soluble proteins, protein-bound hexosamines and sialic acids content, in liver tissue. Electrophoretic examination of the serum proteins showed the increase of alpha 1- and beta 2-globulins and the decrease of albumin concentration. Changes in the level of glycoproteins fractions and protein-bound carbohydrates in blood serum were described also. Estimation of enzymes activity showed the decrease of alanine and aspartate transaminase activity in blood serum caused by the strong decrease of the cytoplasmic fraction of these enzymes. However the simultaneous increase of the mitochondrial fraction of transaminases activity was observed. The decrease of the activity of choline esterase was found also. Similar changes of enzymes activity were found in liver tissue. Histopathological studies were done for the further clearing the influenze of nitrogen dioxide on serum and liver proteins concentration and enzymes activity. It was found that after long-term exposure to nitrogen dioxide the destruction processes may be observed in the liver. The possible mechanism of the nitrogen dioxide-induced damage of protein metabolism is discussed.

  14. Sulfur dioxide and nitrogen oxides emissions from U.S. pulp and paper mills, 1980-2005.

    Science.gov (United States)

    Pinkerton, John E

    2007-08-01

    Comprehensive surveys conducted at 5-yr intervals were used to estimate sulfur dioxide (SO,) and nitrogen oxides (NO.) emissions from U.S. pulp and paper mills for 1980, 1985, 1990, 1995, 2000, and 2005. Over the 25-yr period, paper production increased by 50%, whereas total SO, emissions declined by 60% to 340,000 short tons (t) and total NO, emissions decreased approximately 15% to 230,000 t. The downward emission trends resulted from a combination of factors, including reductions in oil and coal use, steadily declining fuel sulfur content, lower pulp and paper production in recent years, increased use of flue gas desulfurization systems on boilers, growing use of combustion modifications and add-on control systems to reduce boiler and gas turbine NO, emissions, and improvements in kraft recovery furnace operations.

  15. A broadband cavity enhanced absorption spectrometer for aircraft measurements of glyoxal, methylglyoxal, nitrous acid, nitrogen dioxide, and water vapor

    Science.gov (United States)

    Min, K.-E.; Washenfelder, R. A.; Dubé, W. P.; Langford, A. O.; Edwards, P. M.; Zarzana, K. J.; Stutz, J.; Lu, K.; Rohrer, F.; Zhang, Y.; Brown, S. S.

    2016-02-01

    We describe a two-channel broadband cavity enhanced absorption spectrometer (BBCEAS) for aircraft measurements of glyoxal (CHOCHO), methylglyoxal (CH3COCHO), nitrous acid (HONO), nitrogen dioxide (NO2), and water (H2O). The instrument spans 361-389 and 438-468 nm, using two light-emitting diodes (LEDs) and a single grating spectrometer with a charge-coupled device (CCD) detector. Robust performance is achieved using a custom optical mounting system, high-power LEDs with electronic on/off modulation, high-reflectivity cavity mirrors, and materials that minimize analyte surface losses. We have successfully deployed this instrument during two aircraft and two ground-based field campaigns to date. The demonstrated precision (2σ) for retrievals of CHOCHO, HONO and NO2 are 34, 350, and 80 parts per trillion (pptv) in 5 s. The accuracy is 5.8, 9.0, and 5.0 %, limited mainly by the available absorption cross sections.

  16. A broadband cavity enhanced absorption spectrometer for aircraft measurements of glyoxal, methylglyoxal, nitrous acid, nitrogen dioxide, and water vapor

    Directory of Open Access Journals (Sweden)

    K.-E. Min

    2015-10-01

    Full Text Available We describe a two-channel broadband cavity enhanced absorption spectrometer (BBCEAS for aircraft measurements of glyoxal (CHOCHO, methylglyoxal (CH3COCHO, nitrous acid (HONO, nitrogen dioxide (NO2, and water (H2O. The instrument spans 361–389 and 438–468 nm, using two light emitting diodes (LEDs and a grating spectrometer with a charge-coupled device (CCD detector. Robust performance is achieved using a custom optical mounting system, high power LEDs with electronic on/off modulation, state-of-the-art cavity mirrors, and materials that minimize analyte surface losses. We have successfully deployed this instrument during two aircraft and two ground-based field campaigns to date. The demonstrated precision (2σ for retrievals of CHOCHO, HONO and NO2 are 34, 350 and 80 pptv in 5 s. The accuracy is 5.8, 9.0 and 5.0 % limited mainly by the available absorption cross sections.

  17. KEY COMPARISON: Final report on key comparison APMP.QM-K1.d: sulphur dioxide in nitrogen

    Science.gov (United States)

    Kato, Kenji; Maruyama, Masaaki; Seog Kim, Jin; Hyub Oh, Sang; Kim, Byung Moon; Han, Qiao; Zhou, Zeyi

    2008-01-01

    The aim of this comparison was to compare capabilities for the preparation and value assignment of gas mixture standards for sulphur dioxide in air (or nitrogen), maintained at national metrology institutes (NMIs). The measurements in this key comparison took place in 2006. There were three participants and one coordinating laboratory. The key comparison reference value (KCRV) was based on the gravimetric preparation for all components. The range of the nominal amount-of-substance fractions of the comparison standard is 90 µmol/mol to 100 µmol/mol. The Chemical Evaluation Research Institute (CERI, Japan) prepared gravimetric mixture samples of sulfur dioxide in nitrogen in 10 L aluminium cylinders with a passivated inner surface. The homogeneity and long term stability of these samples were evaluated at CERI before and after the shipment of the cylinders to the participants. The uncertainty of the standard gases including the long term stability was estimated to be 0.1 %. Each participating laboratory was shipped one cylinder to be analyzed and then returned to the CERI. Three participants submitted results that were within 0.6% of the relevant reference value. In these cases, the estimated uncertainties were larger than the deviation from the reference value. The agreement of the results in this key comparison is good. CERI is the link laboratory between CCQM-K1.d and APMP.QM-K4. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  18. Nitrogen monoxide vector of ultrasonic atomizing inhalation improves vertebro-basilar artery insufficiency Hemodynamic changes are detected by transcranial Doppler test

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    BACKGROUND: Latest researches at home and abroad indicate that glycerol trinitrate plays its function because it can metabolize into nitrogen monoxide (NO) in vivo.OBJECTIVE: To study the therapeutic effects of NO vector of ultrasonic atomizing inhalation on vertebro-basilar artery insufficiency (VBI) through transcranial Doppler (TCD) detection and serum NO content and indirect effect of TCD on cerebral blood flow changes.DESIGN: Randomized grouping and controlled clinical study.SETTING: Department of Neurology, the Fourth People's Hospital of Jinan.PARTICIPANTS: A total of 130 patients who were diagnosed as VBI were selected from Department of Neurology, the Fourth People's Hospital of Jinan from December 2001 to December 2005. The involved inpatients were checked by CT and MRI, and met the VBI diagnostic standard enacted by the Fourth National Academic Meeting of Cerebrovascular Disease in 1995. All patients and their relatives provided the confirmed consent. They were randomly divided into low-dose treatment group (n =60), high-lose treatment group (n =30) and control group (n =40).METHODS: Patients in the low-dose and high-dose treatment groups were given ultrasonic atomizing inhalation of 3 mg and 5 mg glycerol trinitrate, respectively, for 20 minutes, once a day. In addition,ligustrazine and energy mixture were used once a day for three days in a course. Cases in the control group were only given ligustrazine and energy mixture. All selected cases accepted TCD, blood NO content was checked at the time of beginning, after the first time and after a period of treatment. According to the TCD test, VBI patients were divided into two groups (high-low flow velocity). The vertebral artery (VA) and basal artery (BA) of left or right sides were detected by 2 Hz detector via occipital window.MAIN OUTCOME MEASURES: ① Blood flow velocity of systolic phase, blood flow velocity of diastole phase and vascular resistance in left and right VA and BA detected by using TCD

  19. Oxidation of thiamine on reaction with nitrogen dioxide generated by ferric myoglobin and hemoglobin in the presence of nitrite and hydrogen peroxide.

    Science.gov (United States)

    Stepuro, I I; Oparin, A Yu; Stsiapura, V I; Maskevich, S A; Titov, V Yu

    2012-01-01

    It is shown that nitrogen dioxide oxidizes thiamine to thiamine disulfide, thiochrome, and oxodihydrothiochrome (ODTch). The latter is formed during oxidation of thiochrome by nitrogen dioxide. Nitrogen dioxide was produced by incubation of nitrite with horse ferric myoglobin and human hemoglobin in the presence of hydrogen peroxide. After addition of tyrosine or phenol to aqueous solutions containing oxoferryl forms of the hemoproteins, thiamine, and nitrite, the yield of thiochrome greatly increased, whereas the yield of ODTch decreased. In the presence of high concentrations of tyrosine or phenol compounds ODTch was not formed at all. The neutral form of thiamine with the closed thiazole cycle and minor tricyclic form of thiamine do not enter the heme pocket of the protein and do not interact with the oxoferryl heme complex Fe(IV=O) or porphyrin radical. The tricyclic form of thiamine is oxidized to thiochrome by tyrosyl radicals located on the surface of the hemoprotein. The thiol form of thiamine is oxidized to thiamine disulfide by both hemoprotein tyrosyl radicals and oxoferryl heme complexes. Nitrite and also tyrosine, tyramine, and phenol readily penetrate into the heme pocket of the protein and reduce the oxyferryl complex to ferric cation. These reactions yield nitrogen dioxide as well as tyrosyl and phenoxyl radicals of tyrosine molecules and phenol compounds, respectively. Tyrosyl and phenoxyl radicals of low molecular weight compounds oxidize thiamine only to thiochrome and thiamine disulfide. The effect of oxoferryl forms of myoglobin and hemoglobin, nitrogen dioxide, and phenol on thiamine oxidative transformation as well as antioxidant properties of the hydrophobic thiamine metabolites thiochrome and ODTch are discussed.

  20. 40 CFR 77.6 - Penalties for excess emissions of sulfur dioxide and nitrogen oxides.

    Science.gov (United States)

    2010-07-01

    ... excess emissions, a demand notice for the payment. (d)(1) Except for wire transfers made in accordance... penalties of $25,000 or more may be made by wire transfer to the U.S. Treasury at the Federal Reserve Bank... contemporaneous emission limitations or annual heat input limits, then excess emissions of nitrogen oxides...

  1. Characterization of narrow micropores in almond shell biochars by nitrogen, carbon dioxide, and hydrogen adsorption

    Science.gov (United States)

    Characterization of biochars usually includes surface area and pore volume determination by nitrogen adsorption. In this study, we show that there is a substantial pore volume in biochars created via slow pyrolysis from low- and high-ash almond shells that cannot be characterized in this fashion due...

  2. Methanol Droplet Extinction in Oxygen/Carbon-dioxide/Nitrogen Mixtures in Microgravity: Results from the International Space Station Experiments

    Science.gov (United States)

    Nayagam, Vedha; Dietrich, Daniel L.; Ferkul, Paul V.; Hicks, Michael C.; Williams, Forman A.

    2012-01-01

    Motivated by the need to understand the flammability limits of condensed-phase fuels in microgravity, isolated single droplet combustion experiments were carried out in the Combustion Integrated Rack Facility onboard the International Space Station. Experimental observations of methanol droplet combustion and extinction in oxygen/carbon-dioxide/nitrogen mixtures at 0.7 and 1 atmospheric pressure in quiescent microgravity environment are reported for initial droplet diameters varying between 2 mm to 4 mm in this study.The ambient oxygen concentration was systematically lowered from test to test so as to approach the limiting oxygen index (LOI) at fixed ambient pressure. At one atmosphere pressure, ignition and some burning were observed for an oxygen concentration of 13% with the rest being nitrogen. In addition, measured droplet burning rates, flame stand-off ratios, and extinction diameters are presented for varying concentrations of oxygen and diluents. Simplified theoretical models are presented to explain the observed variations in extinction diameter and flame stand-off ratios.

  3. Nitrogen-doped titanium dioxide photocatalysts for visible response prepared by using organic compounds

    Directory of Open Access Journals (Sweden)

    Yoshio Nosaka, Masami Matsushita, Junichi Nishino and Atsuko Y. Nosaka

    2005-01-01

    Full Text Available In order to utilize visible light in photocatalytic reactions, nitrogen atoms were doped in commercially available photocatalytic TiO2 powders by using an organic compound such as urea and guanidine. Analysis by X-ray photoelectron spectroscopy (XPS indicated that N atoms were incorporated into two different sites of the bulk phase of TiO2. A significant shift of the absorption edge to a lower energy and a higher absorption in the visible light region were observed. These N-doped TiO2 powders exhibited photocatalytic activity for the decomposition of 2-propanol in aqueous solution under visible light irradiation. The photocatalytic activity increased with the decrease of doped N atoms in O site, while decreased with decrease of the other sites. Degradation of photocatalytic activity based on the release of nitrogen atoms was observed for the reaction in the aqueous suspension system.

  4. Effects of carbon dioxide and nitrogen fertilization on phenolic content in Poa annua L.

    Science.gov (United States)

    Martijn Bezemer T; Hefin Jones T; E Newington J

    2000-11-01

    Different but partially overlapping hypotheses have been developed to predict the allocation of phenolics in elevated atmospheric CO(2). The carbon-nutrient balance hypothesis predicts increased allocation to phenolics due to reduced relative availability of nitrogen. The growth-differentiation balance hypothesis states that allocation will depend on source and sink strength, while the protein competition model predicts that allocation will remain unchanged. We grew Poa annua at two CO(2) concentrations in soils of three different nutrient levels. Although plant-tissue nitrogen levels were reduced in high CO(2) and photosynthetic rate increased, phenolic concentration and biomass allocation remained unchanged. We discuss these data in the context of the three models' predictions of phenolic allocation in conditions of elevated CO(2).

  5. Photocatalytic equipment with nitrogen-doped titanium dioxide for air cleaning and disinfecting

    Science.gov (United States)

    Son Le, Thanh; Buu Ngo, Quoc; Dung Nguyen, Viet; Chau Nguyen, Hoai; Hien Dao, Trong; Tin Tran, Xuan; Kabachkov, E. N.; Balikhin, I. L.

    2014-03-01

    Nitrogen-doped TiO2 nanoparticle photocatalysts were synthesized by a sol-gel procedure using tetra-n-butyl orthotitanate as a titanium precursor and urea as a nitrogen source. Systematic studies for the preparation parameters and their impact on the material's structure were carried out by multiple techniques: thermogravimetric and differential scanning calorimetric analysis, x-ray diffraction, scanning electron microscope, transmission electron microscopy, energy dispersive x-ray spectroscopy and UV-Vis diffuse reflectance spectrophotometry showed that the nitrogen-doped TiO2 calcined at 500 °C for 3 h exhibited a spherical form with a particle size about 15-20 nm and crystal phase presented a mixture of 89.12% anatase. The obtained product was deposited on a porous quartz tube (D = 74 mm l = 418 mm) to manufacture an air photocatalytic cleaner as a prototype of the TIOKRAFT company's equipment. The created air cleaner was able to remove 60% of 10 ppm acetone within 390 min and degrade 98.5% of bacteria (total aerobic bacteria and fungi, 300 cfu m-3) within 120 min in a 10 m3 box. These photodegradation activities of N-TiO2 are higher than that of the commercial nano-TiO2 (Skyspring Inc., USA, particle size of 5-10 nm).

  6. Adsorption of Pure Methane, Nitrogen, and Carbon Dioxide and Their Mixtures on San Juan Basin Coal

    Energy Technology Data Exchange (ETDEWEB)

    K. A. M. Gasem; R. L. Robinson; S. R. Reeves

    2002-03-01

    The major objectives of this project were to (a) measure the adsorption behavior of pure methane, nitrogen, CO{sub 2} and their binary and ternary mixtures on wet Tiffany coal at 130 F and pressures to 2000 psia; (b) correlate the equilibrium adsorption isotherm data using the extended Langmuir model, the Langmuir model, the loading ratio correlation and the Zhou-Gasem-Robinson equation of state; and (c) establish sorption-time estimates for the pure components. Specific accomplishments are summarized below regarding the complementary tasks involving experimental work and data correlation. Representative coal samples from BP Amoco Tiffany Injection Wells No.1 and No.10 were prepared, as requested. The equilibrium moisture content and particle size distribution of each coal sample were determined. Compositional coal analyses for both samples were performed by Huffman Laboratories, Inc. Pure gas adsorption for methane on wet Tiffany coal samples from Injection Wells No.1 and No.10 was measured separately at 130 F (327.6 K) and pressures to 2000 psia (13.7 MPa). The average expected uncertainty in these data is about 3% (9 SCF/ton). Our measurements indicate that the adsorption isotherms of the two coal samples exhibit similar Langmuir-type behavior. For the samples from the two wells, a maximum variation of about 5% in the amount adsorbed is observed at 2000 psia. Gas adsorption isotherms were measured for pure methane, nitrogen and CO{sub 2} on a wet, mixed Tiffany coal sample. The coal sample was an equal-mass mixture of coals from Well No.1 and Well No.10. The adsorption measurements were conducted at 130 F at pressures to 2000 psia. The adsorption isotherms have average expected experimental uncertainties of 3% (9 SCF/ton), 6% (8 SCF/ton), and 7% (62 SCF/ton) for methane, nitrogen, and CO{sub 2}, respectively. Adsorption isotherms were measured for methane/nitrogen, methane/CO{sub 2} and nitrogen/CO{sub 2} binary mixtures on wet, mixed Tiffany coal at 130 F and

  7. Achievement report for fiscal 1998 on the preceding research related to global environment industry technologies. Survey and research on reduction of nitrogen monoxide; 1998 nendo chikyu sangyo gijutsu ni kakawaru sendo kenkyu asanka chisso no haishutsu teigen ni kansuru chosa kenkyu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    Nitrogen monoxide is a strong greenhouse effect gas having warming up index per molecule 300 times greater than that of CO2, and is designated as the object of reduction in the Kyoto Conference. The present preceding research discusses necessity of performing research and development works related to reducing the emission of nitrogen monoxide, and if it is necessary, places the final objective on proposition of what researches should be planned. Fiscal 1997 being the first fiscal year of the preceding research has surveyed emission amount from different emission sources, and enumerated the research and development assignments. Fiscal 1998 falling under the final fiscal year summarizes the emission amount including the future trends, surveys the feasibility of the promising technological measures through experiments, and proposed finally a research and development plan desired of implementation in the future. The proposal contains a research plan placing development of nitrogen monoxide decomposing catalysts and automobile catalysts as the main objectives. Among the domestic nitrogen monoxide generating sources, about 2/3 is the man-made generation sources, hence catalysts, if developed, may be applied to such facilities as combustion furnaces. (NEDO)

  8. Copper-catalyzed domino synthesis of nitrogen heterocycle-fused benzoimidazole and 1,2,4-benzothiadiazine 1,1-dioxide derivatives.

    Science.gov (United States)

    Yang, Daoshan; An, Baojuan; Wei, Wei; Tian, Laijin; Huang, Ben; Wang, Hua

    2015-02-09

    A convenient copper-catalyzed domino method for the synthesis of nitrogen heterocycle-fused benzoimidazole and 1,2,4-benzothiadiazine 1,1-dioxides has been developed using readily available 2-bromo-N-phenylbenzenesulfonamides and benzimidazole derivatives as the starting materials. The domino process comprises an Ullmann-type N-arylation and intramolecular C-H amination. The inexpensive and efficient copper-catalyzed method should provide a new and useful strategy for for constructing novel, biologically interesting heterocycles containing benzoimidazole and 1,2,4-benzothiadiazine 1,1-dioxide motifs.

  9. Carbon monoxide poisoning

    Science.gov (United States)

    ... and smokers. Carbon monoxide can harm a fetus (unborn baby still in the womb). Symptoms of carbon ... symptoms Outlook (Prognosis) Carbon monoxide poisoning can cause death. For those who survive, recovery is slow. How ...

  10. Bi-phasic titanium dioxide nanoparticles doped with nitrogen and neodymium for enhanced photocatalysis

    Science.gov (United States)

    Gomez, Virginia; Bear, Joseph C.; McNaughter, Paul D.; McGettrick, James D.; Watson, Trystan; Charbonneau, Cecile; O'Brien, Paul; Barron, Andrew R.; Dunnill, Charles W.

    2015-10-01

    Bi-phasic or multi-phasic composite nanoparticles for use in photocatalysis have been produced by a new synthetic approach. Sol-gel methods are used to deposit multiple layers of active material onto soluble substrates. In this work, a layer of rutile (TiO2) was deposited onto sodium chloride pellets followed by an annealing step and a layer of anatase. After dissolving the substrate, bi-phasic nanoparticles containing half anatase and half rutile TiO2; with ``Janus-like'' characteristics are obtained. Nitrogen and neodymium doping of the materials were observed to enhance the photocatalytic properties both under UV and white light irradiation. The unique advantage of this synthetic method is the ability to systematically dope separate sides of the nanoparticles. Nitrogen doping was found to be most effective on the anatase side of the nanoparticle while neodymium was found to be most effective on the rutile side. Rhodamine B dye was effectively photodegraded by co-doped particles under white light.Bi-phasic or multi-phasic composite nanoparticles for use in photocatalysis have been produced by a new synthetic approach. Sol-gel methods are used to deposit multiple layers of active material onto soluble substrates. In this work, a layer of rutile (TiO2) was deposited onto sodium chloride pellets followed by an annealing step and a layer of anatase. After dissolving the substrate, bi-phasic nanoparticles containing half anatase and half rutile TiO2; with ``Janus-like'' characteristics are obtained. Nitrogen and neodymium doping of the materials were observed to enhance the photocatalytic properties both under UV and white light irradiation. The unique advantage of this synthetic method is the ability to systematically dope separate sides of the nanoparticles. Nitrogen doping was found to be most effective on the anatase side of the nanoparticle while neodymium was found to be most effective on the rutile side. Rhodamine B dye was effectively photodegraded by co

  11. CARBON MONOXIDE TREATMENT GUIDELINES

    Directory of Open Access Journals (Sweden)

    Miran Brvar

    2014-02-01

    Full Text Available Carbon monoxide is the leading cause of unintentional poisoning-related death in Slovenia. It is an odorless, colorless gas that usually remains undetectable until exposures result in injury or death. Exposure to carbon monoxide is most commonly accompanied by headache, nausea, vomiting, dizziness, confusion, drowsiness, fatigue and collapse. Carbon monoxide poisoning management includes normobaric oxygen therapy. Hyperbaric-oxygen treatments reduce the risk of cognitive sequelae after carbon monoxide poisoning. 

  12. Bi-phasic titanium dioxide nanoparticles doped with nitrogen and neodymium for enhanced photocatalysis.

    Science.gov (United States)

    Gomez, Virginia; Bear, Joseph C; McNaughter, Paul D; McGettrick, James D; Watson, Trystan; Charbonneau, Cecile; O'Brien, Paul; Barron, Andrew R; Dunnill, Charles W

    2015-11-14

    Bi-phasic or multi-phasic composite nanoparticles for use in photocatalysis have been produced by a new synthetic approach. Sol-gel methods are used to deposit multiple layers of active material onto soluble substrates. In this work, a layer of rutile (TiO2) was deposited onto sodium chloride pellets followed by an annealing step and a layer of anatase. After dissolving the substrate, bi-phasic nanoparticles containing half anatase and half rutile TiO2; with "Janus-like" characteristics are obtained. Nitrogen and neodymium doping of the materials were observed to enhance the photocatalytic properties both under UV and white light irradiation. The unique advantage of this synthetic method is the ability to systematically dope separate sides of the nanoparticles. Nitrogen doping was found to be most effective on the anatase side of the nanoparticle while neodymium was found to be most effective on the rutile side. Rhodamine B dye was effectively photodegraded by co-doped particles under white light.

  13. Visible-Light Photoredox Catalysis: Selective Reduction of Carbon Dioxide to Carbon Monoxide by a Nickel N-Heterocyclic Carbene-Isoquinoline Complex

    Energy Technology Data Exchange (ETDEWEB)

    Thoi, VanSara; Kornienko, Nick; Margarit, C; Yang, Peidong; Chang, Christopher

    2013-06-07

    The solar-driven reduction of carbon dioxide to value-added chemical fuels is a longstanding challenge in the fields of catalysis, energy science, and green chemistry. In order to develop effective CO2 fixation, several key considerations must be balanced, including (1) catalyst selectivity for promoting CO2 reduction over competing hydrogen generation from proton reduction, (2) visible-light harvesting that matches the solar spectrum, and (3) the use of cheap and earth-abundant catalytic components. In this report, we present the synthesis and characterization of a new family of earth-abundant nickel complexes supported by N-heterocyclic carbene amine ligands that exhibit high selectivity and activity for the electrocatalytic and photocatalytic conversion of CO2 to CO. Systematic changes in the carbene and amine donors of the ligand have been surveyed, and [Ni(Prbimiq1)]2+ (1c, where Prbimiq1 = bis(3-(imidazolyl)isoquinolinyl)propane) emerges as a catalyst for electrochemical reduction of CO2 with the lowest cathodic onset potential (Ecat = 1.2 V vs SCE). Using this earth-abundant catalyst with Ir(ppy)3 (where ppy = 2-phenylpyridine) and an electron donor, we have developed a visible-light photoredox system for the catalytic conversion of CO2 to CO that proceeds with high selectivity and activity and achieves turnover numbers and turnover frequencies reaching 98,000 and 3.9 s1, respectively. Further studies reveal that the overall efficiency of this solar-to-fuel cycle may be limited by the formation of the active Ni catalyst and/or the chemical reduction of CO2 to CO at the reduced nickel center and provide a starting point for improved photoredox systems for sustainable carbon-neutral energy conversion.

  14. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... main content Languages 简体中文 English Bahasa Indonesia 한국어 Español ภาษาไทย Tiếng Việt Text Size: Decrease Font Increase ... Monoxide Information Center Carbon Monoxide Information Center En Español The Invisible Killer Carbon monoxide, also known as ...

  15. Photocatalytic Destruction of Nitrogen Monoxide over La3+ and N Co-doped SrTiO3 Powders under Visible Light Irradiation

    Institute of Scientific and Technical Information of China (English)

    王金淑; 马淑云; 王国红

    2004-01-01

    Lanthanum and nitrogen co-doped SrTiO3 was prepared by a mechanochemical reaction using SrTiO3, urea and La2O3 as the raw materials. The samples were characterized by X-ray diffraction, X-ray photoelectron spectrometer, transmission electron microscopy, and nitrogen adsorption-desorption isotherm measurements. Lanthanum doping could increase the doping content of nitrogen in the sample. The sample prepared with 0.2 mol% La2O3, 22 mol% urea and 77.8 mol% SrTiO3 by mechanochemical reaction, which has nearly the same nitrogen and lanthanum doping fractions, exhibited high photocatalytic activities. Under the irradiation of light with wavelength larger than 400, and 290 nm, the photocatalytic activity of nitrogen and lanthanum co-doped SrTiO3 were 2.6 and 2 times greater than that of pure SrTiO3.

  16. Effect of carbon and nitrogen addition on nitrous oxide and carbon dioxide fluxes from thawing forest soils

    Science.gov (United States)

    Haohao, Wu; Xingkai, Xu; Cuntao, Duan; TuanSheng, Li; Weiguo, Cheng

    2017-07-01

    Packed soil-core incubation experiments were done to study the effects of carbon (glucose, 6.4 g C m-2) and nitrogen (NH4Cl and KNO3, 4.5 g N m-2) addition on nitrous oxide (N2O) and carbon dioxide (CO2) fluxes during thawing of frozen soils under two forest stands (broadleaf and Korean pine mixed forest and white birch forest) with two moisture levels (55 and 80% water-filled pore space). With increasing soil moisture, the magnitude and longevity of the flush N2O flux from forest soils was enhanced during the early period of thawing, which was accompanied by great NO3--N consumption. Without N addition, the glucose-induced cumulative CO2 fluxes ranged from 9.61 to 13.49 g CO2-C m-2, which was larger than the dose of carbon added as glucose. The single addition of glucose increased microbial biomass carbon but slightly affected soil dissolved organic carbon pool. Thus, the extra carbon released upon addition of glucose can result from the decomposition of soil native organic carbon. The glucose-induced N2O and CO2 fluxes were both significantly correlated to the glucose-induced total N and dissolved organic carbon pools and influenced singly and interactively by soil moisture and KNO3 addition. The interactive effects of glucose and nitrogen inputs on N2O and CO2 fluxes from forest soils after frost depended on N sources, soil moisture, and vegetation types.

  17. Carbon dioxide enrichment: Data on the response of cotton to varying CO sub 2 , irrigation, and nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Sepanski, R.J. (Tennessee Univ., Knoxville, TN (United States). Energy, Environment and Resources Center); Kimball, B.A.; Mauney, J.R.; La Morte, R.L.; Guinn, G.; Nakayama, F.S.; Radin, J.W.; Mitchell, S.T.; Parker, L.L.; Peresta, G.J.; Nixon, P.E. III; Savoy, B.; Harris, S.M.; MacDonald, R.; Pros, H.; Martinez, J. (Agricultural Research Service, Phoenix, AZ (United States)); Lakatos, E.A. (Arizona Univ., Tucs

    1992-06-01

    This document presents results from field CO{sub 2}-enrichment experiments conducted over five consecutive growing seasons, 1983--1987. These results comprise data concerning the effects of continuous CO{sub 2} enrichment on the growth of cotton under optimal and limiting levels of water and nitrogen. Unlike many prior C0{sub 2} enrichment experiments in growth chambers or greenhouses, these studies were conducted on field-planted cotton at close to natural conditions using the open-top chamber approach. Measurements were made on a variety of crop response variables at intervals during the growing season and upon crop harvest. The initial experiment examined the effects of varying C0{sub 2} concentration only. In the following two seasons, the interactive effects of C0{sub 2} concentration and water availability were studied. In the final two seasons, the effects of the three-way interaction between C0{sub 2} concentration, water availability, and nitrogen fertility were investigated. The data comprise three types of information: identification variables (such as year, institution and situ codes, and treatment regimens), intermediate growth measurements (such as plant height, leaf area index, number of flowers, and dry weight of leaves) taken at various times during the growing season, and crop harvest results (such as lint yield, seed yield, and total aboveground dry biomass). They are available free of charge as a numeric data package (NAP) from the Carbon Dioxide Information Analysis Center. The NAP consists of this document and a magnetic tape (or a floppy diskette, upon request) containing machine-readable files. This document provides sample listings of the CO{sub 2} enrichment response data as they appear on the magnetic tape or floppy diskette and provides detailed descriptions of the design and methodology of these experiments, as well as a complete hard copy listing of all of the data in the form of a supplemental text provided as an appendix.

  18. Carbon dioxide enrichment: Data on the response of cotton to varying CO{sub 2}, irrigation, and nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Sepanski, R.J. [Tennessee Univ., Knoxville, TN (United States). Energy, Environment and Resources Center; Kimball, B.A.; Mauney, J.R.; La Morte, R.L.; Guinn, G.; Nakayama, F.S.; Radin, J.W.; Mitchell, S.T.; Parker, L.L.; Peresta, G.J.; Nixon, P.E. III; Savoy, B.; Harris, S.M.; MacDonald, R.; Pros, H.; Martinez, J. [Agricultural Research Service, Phoenix, AZ (United States); Lakatos, E.A. [Arizona Univ., Tucson, AZ (United States). Dept. of Soil and Water Science

    1992-06-01

    This document presents results from field CO{sub 2}-enrichment experiments conducted over five consecutive growing seasons, 1983--1987. These results comprise data concerning the effects of continuous CO{sub 2} enrichment on the growth of cotton under optimal and limiting levels of water and nitrogen. Unlike many prior C0{sub 2} enrichment experiments in growth chambers or greenhouses, these studies were conducted on field-planted cotton at close to natural conditions using the open-top chamber approach. Measurements were made on a variety of crop response variables at intervals during the growing season and upon crop harvest. The initial experiment examined the effects of varying C0{sub 2} concentration only. In the following two seasons, the interactive effects of C0{sub 2} concentration and water availability were studied. In the final two seasons, the effects of the three-way interaction between C0{sub 2} concentration, water availability, and nitrogen fertility were investigated. The data comprise three types of information: identification variables (such as year, institution and situ codes, and treatment regimens), intermediate growth measurements (such as plant height, leaf area index, number of flowers, and dry weight of leaves) taken at various times during the growing season, and crop harvest results (such as lint yield, seed yield, and total aboveground dry biomass). They are available free of charge as a numeric data package (NAP) from the Carbon Dioxide Information Analysis Center. The NAP consists of this document and a magnetic tape (or a floppy diskette, upon request) containing machine-readable files. This document provides sample listings of the CO{sub 2} enrichment response data as they appear on the magnetic tape or floppy diskette and provides detailed descriptions of the design and methodology of these experiments, as well as a complete hard copy listing of all of the data in the form of a supplemental text provided as an appendix.

  19. Adsorption of carbon dioxide, methane and nitrogen on an ultramicroporous copper metal-organic framework.

    Science.gov (United States)

    Wu, Xiaofei; Yuan, Bin; Bao, Zongbi; Deng, Shuguang

    2014-09-15

    An ultramicroporous copper metal-organic framework (Cu-MOF), Cu(hfipbb)(H2hfipbb)0.5 [H2hfipbb=4,4'-(hexafluoro-isopropylidene) bis(benzoic acid)] was successfully synthesized by a microwave-assisted method (1) with a shorter reaction time and higher MOFs yield. The obtained Cu-MOF sample was characterized with scanning electron microscopy for crystal structure, powder X-ray diffraction for phase structure, and carbon dioxide adsorption at 273 K for pore textural properties. Single-component adsorption (adsorption equilibrium and kinetics) of CO2, CH4, and N2 on 1 was measured using a Micromeritics ASAP 2020 adsorption porosimeter at 278, 298 and 318 K, and pressures up to 1 bar. Isosteric heats of adsorption, Henry's constants, and diffusion time constants were calculated and carefully analyzed. Adsorption equilibrium selectivity (α), adsorbent selection parameter for pressure swing adsorption processes (S), kinetic selectivity and combined separation selectivity (β) for CO2/CH4, CO2/N2 and CH4/N2 binary mixtures were estimated based on the single-component adsorption data. The relative high values of the adsorption selectivities suggest that Cu-MOF is a promising adsorbent for separating CO2/CH4, CO2/N2 and CH4/N2 gas pairs. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. RESEARCH ON ELECTRIC ARC REDUCTION OF CARBON DIOXIDE,

    Science.gov (United States)

    CARBON DIOXIDE , REDUCTION(CHEMISTRY), ELECTRIC ARCS, CHEMICAL REACTIONS, HEAT OF REACTION, GAS FLOW, OXYGEN, CARBON COMPOUNDS, MONOXIDES, ELECTRODES, LABORATORY EQUIPMENT, HIGH TEMPERATURE, PLASMAS(PHYSICS), ENERGY.

  1. Nitrogen

    Science.gov (United States)

    Apodaca, Lori E.

    2013-01-01

    The article presents an overview of the nitrogen chemical market as of July 2013, including the production of ammonia compounds. Industrial uses for ammonia include fertilizers, explosives, and plastics. Other topics include industrial capacity of U.S. ammonia producers CF Industries Holdings Inc., Koch Nitrogen Co., PCS Nitrogen, Inc., and Agrium Inc., the impact of natural gas prices on the nitrogen industry, and demand for corn crops for ethanol production.

  2. Nitrogen dioxide induced changes in level of free fatty acids, triglyceride, esterified fatty acid, ganglioside and lipase activity in the guinea pig brain

    Energy Technology Data Exchange (ETDEWEB)

    Farahani, H.; Hasan, M. (Interdisciplinary Brain Research Centre, Jawaharlal Nehru Medical College, Aligarh Muslim University, (India))

    1992-02-01

    The biochemical response to controlled inhalation of nitrogen dioxide (NO2) was studied in 18 male guinea pigs. Animals were exposed to 2.5, 5.0, and 10 ppm NO2 for 2h daily for 35 consecutive days, and the results compared with six control animals exposed to filtered air for 2h daily for same period. Five biochemical parameters, including triglyceride, free fatty acids, esterified fatty acid, ganglioside and lipase activity were measured immediately after the last day of exposure. At 2.5 ppm NO2 inhalation no significant changes occurred in any region of the central nervous system (CNS). While as the dose concentration was increased to 5 and 10 ppm nitrogen dioxide, significant dose-related alteration were observed in the levels of triglyceride, free fatty acid, esterified fatty acid, ganglioside and lipase activity in the different regions of the guinea pig CNS.

  3. The photosynthesis - leaf nitrogen relationship at ambient and elevated atmospheric carbon dioxide: a meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Andrew G. Peterson; J. Timothy Ball; Yiqi Luo; Christopher B. Field; Peter B. Reich; Peter S. Curtis; Kevin L. Griffin; Carla S Gunderson; Richard J. Norby; David T. Tissue; Manfred Forstreuter; Ana Rey; Christoph S. Vogel; CMEAL collaboration

    1998-09-25

    Estimation of leaf photosynthetic rate (A) from leaf nitrogen content (N) is both conceptually and numerically important in models of plant, ecosystem and biosphere responses to global change. The relationship between A and N has been studied extensively at ambient CO{sub 2} but much less at elevated CO{sub 2}. This study was designed to (1) assess whether the A-N relationship was more similar for species within than between community and vegetation types, and (2) examine how growth at elevated CO{sub 2} affects the A-N relationship. Data were obtained for 39 C{sub 3} species grown at ambient CO{sub 2} and 10 C{sub 3} species grown at ambient and elevated CO{sub 2}. A regression model was applied to each species as well as to species pooled within different community and vegetation types. Cluster analysis of the regression coefficients indicated that species measured at ambient CO{sub 2} did not separate into distinct groups matching community or vegetation type. Instead, most community and vegetation types shared the same general parameter space for regression coefficients. Growth at elevated CO{sub 2} increased photosynthetic nitrogen use efficiency for pines and deciduous trees. When species were pooled by vegetation type, the A-N relationship for deciduous trees expressed on a leaf-mass bask was not altered by elevated CO{sub 2}, while the intercept increased for pines. When regression coefficients were averaged to give mean responses for different vegetation types, elevated CO{sub 2} increased the intercept and the slope for deciduous trees but increased only the intercept for pines. There were no statistical differences between the pines and deciduous trees for the effect of CO{sub 2}. Generalizations about the effect of elevated CO{sub 2} on the A-N relationship, and differences between pines and deciduous trees will be enhanced as more data become available.

  4. Assessing traffic and industrial contributions to ambient nitrogen dioxide and volatile organic compounds in a low pollution urban environment.

    Science.gov (United States)

    Oiamo, Tor H; Johnson, Markey; Tang, Kathy; Luginaah, Isaac N

    2015-10-01

    Land use regression (LUR) modeling is an effective method for estimating fine-scale distributions of ambient air pollutants. The objectives of this study are to advance the methodology for use in urban environments with relatively low levels of industrial activity and provide exposure assessments for research on health effects of air pollution. Intraurban distributions of nitrogen dioxide (NO2) and the volatile organic compounds (VOCs) benzene, toluene and m- and p-xylene were characterized based on spatial monitoring and LUR modeling in Ottawa, Ontario, Canada. Passive samplers were deployed at 50 locations throughout Ottawa for two consecutive weeks in October 2008 and May 2009. Land use variables representing point, area and line sources were tested as predictors of pooled pollutant distributions. LUR models explained 96% of the spatial variability in NO2 and 75-79% of the variability in the VOC species. Proximity to highways, green space, industrial and residential land uses were significant in the final models. More notably, proximity to industrial point sources and road network intersections were significant predictors for all pollutants. The strong contribution of industrial point sources to VOC distributions in Ottawa suggests that facility emission data should be considered whenever possible. The study also suggests that proximity to road network intersections may be an effective proxy in areas where reliable traffic data are not available.

  5. Changes in Nitrogen Dioxide and Ozone over Southeast and East Asia between Year 2000 and 2030 with Fixed Meteorology

    Directory of Open Access Journals (Sweden)

    Michael Gauss

    2007-01-01

    Full Text Available In the framework of the European Network of Excellence ACCENT changes in near-surface and total tropospheric nitrogen dioxide (NO2 and ozone from year 2000 to 2030 have been calculated for the Southeast and East Asian regions using the chemical transport model Oslo CTM-2. Anthropogenic emissions of ozone precursors for the year 2000 case are taken from the International Institute for Applied Systems Analysis (IIASA. Regarding year 2030 emissions, three different scenarios are compared: 1 IIASA ¡¥current legislation¡¦ (CLE, where current air quality legislation around the world is implemented; 2 IIASA ¡¥maximum feasible reduction¡¦ (MFR, in which all currently available technologies are applied to achieve maximum emission reductions; and 3 the IPCC-SRES A2 scenario, which was used as a high emission estimate in the last IPCC assessment report. While increases in NO2 and ozone are calculated when using the CLE scenario, reductions are seen for the MFR scenario. In the SRES A2 case, increases in NO2 are largest, locally leading to ozone reductions at the surface resulting from titration effects. The model calculations suggest that air quality problems will be severely aggravated over Southeast and East Asia if current legislation is not attained.

  6. Seven years of carbon dioxide enrichment, nitrogen fertilization and plant diversity influence arbuscular mycorrhizal fungi in a grassland ecosystem.

    Science.gov (United States)

    Antoninka, Anita; Reich, Peter B; Johnson, Nancy Collins

    2011-10-01

    • We tested the prediction that the abundance and diversity of arbuscular mycorrhizal (AM) fungi are influenced by resource availability and plant community composition by examining the joint effects of carbon dioxide (CO(2) ) enrichment, nitrogen (N) fertilization and plant diversity on AM fungi. • We quantified AM fungal spores and extramatrical hyphae in 176 plots after 7 yr of treatment with all combinations of ambient or elevated CO(2) (368 or 560 ppm), with or without N fertilization (0 or 4 g Nm(-2) ), and one (monoculture) or 16 host plant species (polyculture) in the BioCON field experiment at Cedar Creek Ecosystem Science Reserve, Minnesota, USA. • Extramatrical hyphal lengths were increased by CO(2) enrichment, whereas AM spore abundance decreased with N fertilization. Spore abundance, morphotype richness and extramatrical hyphal lengths were all greater in monoculture plots. A structural equation model showed AM fungal biovolume was most influenced by CO(2) enrichment, plant community composition and plant richness, whereas spore richness was most influenced by fungal biovolume, plant community composition and plant richness. • Arbuscular mycorrhizal fungi responded to differences in host community and resource availability, suggesting that mycorrhizal functions, such as carbon sequestration and soil stability, will be affected by global change.

  7. Socioeconomic differences in nitrogen dioxide ambient air pollution exposure among children in the three largest Canadian cities.

    Science.gov (United States)

    Pinault, Lauren; Crouse, Daniel; Jerrett, Michael; Brauer, Michael; Tjepkema, Michael

    2016-07-20

    Nitrogen dioxide (NO₂) is a marker for traffic-related air pollution, which exhibits strong spatial gradients in large cities. Previous studies have shown that in Canadian cities, exposure to ambient NO₂ is greater in neighbourhoods of low socioeconomic status (SES). As a result of these differences in exposure, air pollution-related health problems may be more prevalent among children in lower SES urban neighbourhoods. Children younger than age 18 enumerated in the 2006 Census who lived in Toronto, Montreal or Vancouver were linked to published air pollution exposure land use regression models to assign exposure at the Dissemination Area (DA) level. Associations between both socioeconomic and visible minority status and exposure to ambient NO₂ among children in these three cities were examined in a series of regression models (OLS and simultaneous autoregressive models that account for spatial autocorrelation). Children in lower income DAs in all three cities were exposed to higher NO₂ concentrations than were children in higher income DAs (mean difference of 2 ppb between lowest and highest income quintiles). In some cities, DAs with larger percentages of children in lone-parent families and visible minority children were characterized by greater NO₂ exposure. The relatively high incidence of air pollution-related diseases (for example, asthma) among children in lower SES neighbourhoods may be attributable, at least in part, to variations in NO₂ air pollution exposure within the same city.

  8. Comparative Analysis of Indoor Levels of Suspended Particulates and Nitrogen Dioxide a Few Hours later after an Asthmatic Attack

    Institute of Scientific and Technical Information of China (English)

    UKPEBOR Emmanuel Ehiabhi; OKUO James Majebi; EKANEM Victor James; UKPEBOR Justina Ebehirieme

    2007-01-01

    Suspended particulates (TSP) and nitrogen dioxide (NO2) are known respiratory irritants linked to asthma aggravation. This pilot study was designed to investigate the role of these pollutants on the frequency of asthmatic attack on two of the inhabitants of a household. The surveillance of TSP and NO2 in this household commenced a few hours later, after one of the occupants suffered an attack. The TSP load determination was done using a High Volume Gravimetric sampler and a light scattering method via a Haz-Dust 10 μm particulate monitor. Palmes Diffusion tubes for NO2 and a portable Crowcon Gasman toxic gas detector were utilized for NO2 screening. In the first day of monitoring in the living room, the in situ particulate sampler (Haz-Dust) recorded a mean TSP level of 26,000the Gasman toxic gas detector for NO2, the NO2 concentration for the first few hours of sampling was lower than 188 μgom-3, the detection limit of this instrument. However, the exact NO2 concentrations for the 7 day monitoring tubes.

  9. Pathophysiologic responses of sheep to brief high level nitrogen dioxide exposure. (Reannouncement with new availability information). Final report

    Energy Technology Data Exchange (ETDEWEB)

    Januszkiewicz, A.J.; Snapper, J.R.; Sturgis, J.W.; Rayburn, D.B.; Dodd, K.T.

    1992-12-31

    The cardiopulmonary response to short-duration, high- concentration nitrogen dioxide (N02) was examined in conscious domestic sheep (Ovis aries). Six intubated animals in each of three groups were administered or approximately 100 or 500 ppm NO2. Pulmonary and systemic hemodynamics, pulmonary mechanics, blood gases and hematologic variables were measured immediately before and after exposure and at 1, 4 and 24 h after exposure. Minute ventilation was monitored during exposure, and a pulmonary histopathologic examination was performed 24 h postexposure. Negligible effects were observed in the control group. Exposure to 100 ppm NO2 caused a modest increase in minute ventilation during exposure, and an increased number of leukocytes were found within interalveolar capillaries upon histologic examination. Exposure to 500 ppm NO2 induced immediate and profound lung irritant responses characterized by increases in lung resistance, respiratory rate and minute ventilation. The exposure was marked by a statistically significant, but small, mixed-venous methemoglobin increase. Pulmonary function progressively deteriorated in the 24-h period following exposure to 500 ppm NO2, and a significant arterial oxygen tension reducting and pulmonary artery pressure increase occurred at 24 h post exposure. Histologic examination after 500 ppm NO2 revealed patchy lobular exudation and accumulation of leukocytes in alveolar sacs and interalveolar capillaries.

  10. MAX-DOAS measurements of nitrogen dioxide at the high altitude sites Zugspitze (2964 m) and Pico Espejo (4765 m)

    Science.gov (United States)

    Schreier, Stefan F.; Richter, Andreas; Wittrock, Folkard; Burrows, John P.

    2015-04-01

    Spectral measurements at two mountain sites were performed with a MAX-DOAS (Multi AXis Differential Optical Absorption Spectroscopy) instrument from February to July 2003 (Zugspitze, Germany) and from March 2004 to November 2008 (Pico Espejo, Venezuela). Here, these measurements are used for the retrieval of slant column densities (SCDs) of nitrogen dioxide (NO2). While at the altitude of observations the NO2 levels are usually small, uplifting of anthropogenic emissions from the valley and in Venezuela also transport of emissions from biomass burning can lead to significant enhancements. Daily, weekly, and seasonal cycles of NO2 SCDs are shown for the two stations, linked to different meteorological conditions and compared between the two sites. In a next step, a preliminary approach to derive vertical column densities (VCDs) is presented. VCDs of NO2 from ground-based MAX-DOAS instruments provide useful information for the validation of satellite instruments such as SCIAMACHY, OMI, and GOME-2. Comparisons between ground-based and satellite-based NO2 VCDs are shown for selected periods.

  11. Use of GIS and ancillary variables to predict volatile organic compound and nitrogen dioxide levels at unmonitored locations

    Science.gov (United States)

    Smith, Luther; Mukerjee, Shaibal; Gonzales, Melissa; Stallings, Casson; Neas, Lucas; Norris, Gary; Özkaynak, Halûk

    In late 1999, passive air sampling of nitrogen dioxide (NO 2) and volatile organic compounds was conducted at 22 school locations and two intensive sites in El Paso, Texas. Our goal was to predict concentrations of NO 2 and benzene, toluene, ethylbenzene, o-xylene, and m, p-xylene at a total of 55 schools. The predictive equations were developed by regressing the passive monitor measurements at the 22 monitored schools on land-use variables derived from a geographic information system (GIS). These GIS-based ancillary variables included distance to the nearest border crossing, elevation, population density, distance to roads with specified traffic volumes, traffic intensity around the schools, and distance to the nearest petroleum facility. The reliability of the predictive equations was assessed at the two intensive monitoring sites. For all pollutants, the most useful predictive ancillary variables were elevation, population density, distance to a border crossing, and distance to a petroleum facility. For estimating NO 2, traffic intensity was also important.

  12. Monitoring of atmospheric nitrogen dioxide by long-path pulsed differential optical absorption spectroscopy using two different light paths.

    Science.gov (United States)

    Kambe, Yasuaki; Yoshii, Yotsumi; Takahashi, Kenshi; Tonokura, Kenichi

    2012-03-01

    Measurements of the local distribution of atmospheric nitrogen dioxide (NO(2)) by long-path pulsed differential optical absorption spectroscopy (LP-PDOAS) in Tokyo during August 2008 are presented. Two LP-PDOAS systems simultaneously measured average NO(2) temporal mixing ratios along two different paths from a single observation point. Two flashing aviation obstruction lights, located 7.0 km north and 6.3 km east from the observation point, were used as light sources, allowing spatiotemporal variations of NO(2) in Tokyo to be inferred. The LP-PDOAS data were compared with ground-based data measured using chemiluminescence. Surface wind data indicated that large inhomogeneities were present in the spatial NO(2) distributions under southerly wind conditions, while northerly wind conditions displayed greater homogeneity between the two systems. The higher correlation in the NO(2) mixing ratio between the two LP-PDOAS systems was observed under northerly wind conditions with a correlation factor R(2) = 0.88. We demonstrated that the combined deployment of two LP-PDOAS systems oriented in different directions provides detailed information on the spatial distribution of NO(2).

  13. Spatial variance and assessment of nitrogen dioxide pollution in major cities of Pakistan along N5-Highway.

    Science.gov (United States)

    Shabbir, Yasir; Khokhar, Muhammad Fahim; Shaiganfar, Reza; Wagner, Thomas

    2016-05-01

    This paper discusses the findings of the first car MAX-DOAS (multi-axis differential optical absorption spectroscopy) field campaign (300km long) along the National Highway-05 (N5-Highway) of Pakistan conducted on 13 and 14 November, 2012. The main objective of the field campaign was to assess the spatial distribution of tropospheric nitrogen dioxide (NO2) columns and corresponding concentrations along the N5-Highway from Islamabad to Lahore. Source identification of NO2 revealed that the concentrations were higher within major cities along the highway. The highest NO2 vertical column densities (NO2 VCDs) were found around two major cities of Rawalpindi and Lahore. This study also presents a comparison of NO2 VCDs measured by the ozone monitoring instrument (OMI) and car MAX-DOAS observations. The comparison revealed similar spatial distribution of the NO2 columns with both car MAX-DOAS and satellite observations, but the car MAX-DOAS observations show much more spatial details. Maximum NO2 VCD retrieved from car MAX-DOAS observations was up to an order of magnitude larger than the OMI observations in urban areas. Copyright © 2015. Published by Elsevier B.V.

  14. Short-term nitrogen dioxide exposure and geomagnetic activity interaction: contribution to emergency hospitalization for acute coronary syndrome.

    Science.gov (United States)

    Vencloviene, Jone; Grazuleviciene, Regina; Babarskiene, Ruta; Dedele, Audrius; Grazulevicius, Tomas

    2011-06-01

    We investigated whether extremely geomagnetic activity may modify the association between short-term nitrogen dioxide (NO₂) exposure and emergency hospitalization for acute coronary syndrome (ACS). A case-crossover study design was used to analyze ACS in 6,594 hospitalized patients at the Clinic of Kaunas, Lithuania. We evaluated the associations between NO₂, geomagnetic activity and the rate of emergency admissions for ACS by logistic regression controlling for seasonal variation, weekdays and meteorological factors. Ambient NO₂ pollution interquartile range increase (IQR) on the day of admission and previous day (lag 0-1) in patients below 65 years of age increase the risk of ACS equal to 24% (95% CI 0.96-1.60). Evidence of effect modification by combined NO₂ and geomagnetic activity was observed in relation to ACS, adjusted OR was 1.61; 95% CI 1.03-2.53. In conclusion, these findings suggest that geomagnetic activity variations may increase the traffic-related air pollution effect on ACS, and highlight environmental factors associated with ischemic heart disease course.

  15. Effect of nitrogen monoxide mediated with estrogen on bone formation%一氧化氮介导雌激素的骨形成增加作用

    Institute of Scientific and Technical Information of China (English)

    涂意辉; 杨安礼; 杜靖远

    2004-01-01

    素诱导骨形成增加的介导剂.%BACKGROUND: Protective mechanism of estrogen on bone formation is not clear. Nitrogen monoxide(NO) induced by estrogen may have a certain effect on bone formation.OBJECTIVE: To investigate the effects of estrogenic treatment on levels of plasma nitrate/nitrite in ovariectomied rats.DESIGN: Randomized controlled trial.SETTING: The department of Orthopaedics of Central Hospital, Yangpu District, Shanghai.PARTICIPANTS: This experiment was performed in the Animal Experimental Center of Tongji Medical University. A total of 36 healthy clean female Sprague-Dawley(SD) rats, aged 3 months old, weighing 220 - 245 g,were provided by the Animal Experimental Center of Tongji Medical University.INTERVENTIONS: Twelve SD rats were given bilateral ovariectomy completely, as ovariotomy group; Twelve SD rats were treated with their bilateral ovary exposed but not resected, as control group, another 12 SD were carried ovocylin every two weeks, as estrogen treated group.-MAIN OUTCOME MEASURES: Expression of NO synthetic enzyme in bone tissue was measured with the method of immunohistochemistry staining;The bone mineral density(BMD) was measured with dual energy X-ray; Bone morphological and metrological measurement was made with image analysis system; The levels of plasma nitrate/nitrite were detected with optical density method.RESULTS: Ovariectomy induced significantly the levels of plasma nitrate/nitrite, BMD, the yolume of trabecular bone as well as other bone morphological and metrological parametes. Six weeks after operation, the mean levels of plasma nitrate/nitrite in the control and ovariectomy groups were (22.4 ± 1.7 ) μmol / L and ( 16.2 ± 3.7 ) μmol / L, respectively; the value of BMD were(0. 245 ± 0. 030) g/cm2 and(0. 189 ± 0. 030) g/cm2, respectively, volume of trabecular bone were (31.97±3.50)% and(17.14± 4.20) %, respectively. The differences between the two groups was significant( P < 0. 01) . Estrogen inhibited these changes induced by ovariectomy

  16. Four-electron deoxygenative reductive coupling of carbon monoxide at a single metal site

    OpenAIRE

    Buss, Joshua A.; Agapie, Theodor

    2016-01-01

    Carbon dioxide is the ultimate source of the fossil fuels that are both central to modern life and problematic: their use increases atmospheric levels of greenhouse gases, and their availability is geopolitically constrained. Using carbon dioxide as a feedstock to produce synthetic fuels might, in principle, alleviate these concerns. Although many homogeneous and heterogeneous catalysts convert carbon dioxide to carbon monoxide, further deoxygenative coupling of carbon monoxide to generate us...

  17. Enhanced sulfate formation by nitrogen dioxide: Implications from in situ observations at the SORPES station

    Science.gov (United States)

    Xie, Yuning; Ding, Aijun; Nie, Wei; Mao, Huiting; Qi, Ximeng; Huang, Xin; Xu, Zheng; Kerminen, Veli-Matti; Petäjä, Tuukka; Chi, Xuguang; Virkkula, Aki; Boy, Michael; Xue, Likun; Guo, Jia; Sun, Jianning; Yang, Xiuqun; Kulmala, Markku; Fu, Congbin

    2015-12-01

    Investigating sulfate formation processes is important not only for air pollution control but also for understanding the climate system. Although the mechanisms of secondary sulfate production have been widely studied, in situ observational evidence implicating an important role of NO2 in SO2 oxidation in the real atmosphere has been rare. In this study, we report two unique cases, from an intensive campaign conducted at the Station for Observing Regional Processes of the Earth System (SORPES) in East China, showing distinctly different mechanisms of sulfate formation by NO2 and related nitrogen chemistry. The first case occurred in an episode of mineral dust mixed with anthropogenic pollutants and especially high concentrations of NOx. It reveals that NO2 played an important role, not only in surface catalytic reactions of SO2 but also in dust-induced photochemical heterogeneous reactions of NO2, which produced additional sources of OH radicals to promote new particle formation and growth. The second case was caused by aqueous oxidation of S(IV) by NO2 under foggy/cloudy conditions with high NH3 concentration. As a by-product, the formed nitrite enhanced HONO formation and further promoted the gas-phase formation of sulfate in the downwind area. This study highlights the effect of NOx in enhancing the atmospheric oxidizing capacity and indicates a potentially very important impact of increasing NOx on particulate pollution formation and regional climate change in East Asia.

  18. Co-implantation of carbon and nitrogen into silicon dioxide for synthesis of carbon nitride materials

    CERN Document Server

    Huang, M B; Nuesca, G; Moore, R

    2002-01-01

    Materials synthesis of carbon nitride has been attempted with co-implantation of carbon and nitrogen into thermally grown SiO sub 2. Following implantation of C and N ions to doses of 10 sup 1 sup 7 cm sup - sup 2 , thermal annealing of the implanted SiO sub 2 sample was conducted at 1000 degree sign C in an N sub 2 ambient. As evidenced in Fourier transform infrared measurements and X-ray photoelectron spectroscopy, different bonding configurations between C and N, including C-N single bonds, C=N double bonds and C=N triple bonds, were found to develop in the SiO sub 2 film after annealing. Chemical composition profiles obtained with secondary ion mass spectroscopy were correlated with the depth information of the chemical shifts of N 1s core-level electrons, allowing us to examine the formation of C-N bonding for different atomic concentration ratios between N and C. X-ray diffraction and transmission electron microscopy showed no sign of the formation of crystalline C sub 3 N sub 4 precipitates in the SiO ...

  19. Processes regulating progressive nitrogen limitation under elevated carbon dioxide: a meta-analysis

    Science.gov (United States)

    Liang, Junyi; Qi, Xuan; Souza, Lara; Luo, Yiqi

    2016-05-01

    The nitrogen (N) cycle has the potential to regulate climate change through its influence on carbon (C) sequestration. Although extensive research has explored whether or not progressive N limitation (PNL) occurs under CO2 enrichment, a comprehensive assessment of the processes that regulate PNL is still lacking. Here, we quantitatively synthesized the responses of all major processes and pools in the terrestrial N cycle with meta-analysis of CO2 experimental data available in the literature. The results showed that CO2 enrichment significantly increased N sequestration in the plant and litter pools but not in the soil pool, partially supporting one of the basic assumptions in the PNL hypothesis that elevated CO2 results in more N sequestered in organic pools. However, CO2 enrichment significantly increased the N influx via biological N fixation and the loss via N2O emission, but decreased the N efflux via leaching. In addition, no general diminished CO2 fertilization effect on plant growth was observed over time up to the longest experiment of 13 years. Overall, our analyses suggest that the extra N supply by the increased biological N fixation and decreased leaching may potentially alleviate PNL under elevated CO2 conditions in spite of the increases in plant N sequestration and N2O emission. Moreover, our syntheses indicate that CO2 enrichment increases soil ammonium (NH4+) to nitrate (NO3-) ratio. The changed NH4+/NO3- ratio and subsequent biological processes may result in changes in soil microenvironments, above-belowground community structures and associated interactions, which could potentially affect the terrestrial biogeochemical cycles. In addition, our data synthesis suggests that more long-term studies, especially in regions other than temperate ones, are needed for comprehensive assessments of the PNL hypothesis.

  20. Evaluation of nitrogen dioxide chemiluminescence monitors in a polluted urban environment

    Directory of Open Access Journals (Sweden)

    M. J. Molina

    2007-05-01

    Full Text Available Data from a recent field campaign in Mexico City are used to evaluate the performance of the EPA Federal Reference Method for monitoring the ambient concentrations of NO2. Measurements of NO2 from standard chemiluminescence monitors equipped with molybdenum oxide converters are compared with those from Tunable Infrared Laser Differential Absorption Spectroscopy (TILDAS and Differential Optical Absorption Spectroscopy (DOAS instruments. A significant interference in the chemiluminescence measurement is shown to account for up to 50% of ambient NO2 concentration during afternoon hours. As expected, this interference correlates well with non-NOx reactive nitrogen species (NOz as well as with ambient O3 concentrations, indicating a photochemical source for the interfering species. A combination of ambient gas phase nitric acid and alkyl and multifunctional alkyl nitrates is deduced to be the primary cause of the interference. Observations at four locations at varying proximities to emission sources indicate that the percentage contribution of HNO3 to the interference decreases with time as the air parcel ages. Alkyl and multifunctional alkyl nitrate concentrations are calculated to reach concentrations as high as several ppb inside the city, on par with the highest values previously observed in other urban locations. Averaged over the MCMA-2003 field campaign, the chemiluminescence monitor interference resulted in an average measured NO2 concentration up to 22% greater than that from co-located spectroscopic measurements. Thus, this interference has the potential to initiate regulatory action in areas that are close to non-attainment and may mislead atmospheric photochemical models used to assess control strategies for photochemical oxidants.

  1. Evaluation of nitrogen dioxide chemiluminescence monitors in a polluted urban environment

    Directory of Open Access Journals (Sweden)

    E. J. Dunlea

    2007-01-01

    Full Text Available Data from a recent field campaign in Mexico City are used to evaluate the performance of the EPA Federal Reference Method for monitoring ambient concentrations of NO2. Measurements of NO2 from standard chemiluminescence monitors equipped with molybdenum oxide converters are compared with those from Tunable Infrared Laser Differential Absorption Spectroscopy (TILDAS and Differential Optical Absorption Spectroscopy (DOAS instruments. A significant interference in the chemiluminescence measurement is shown to account for up to 50% of ambient NO2 concentration during afternoon hours. As expected, this interference correlates well with non-NOx reactive nitrogen species (NOz as well as with ambient O3 concentrations, indicating a photochemical source for the interfering species. A combination of ambient gas phase nitric acid and alkyl and multifunctional alkyl nitrates is deduced to be the primary cause of the interference. Observations at four locations at varying proximities to emission sources indicate that the percentage contribution of HNO3 to the interference decreases with time as the air parcel ages. Alkyl and multifunctional alkyl nitrate concentrations are calculated to be reach concentrations as high as several ppb inside the city, on par with the highest values previously observed in other urban locations. Averaged over the MCMA-2003 field campaign, the CL NOx monitor interference resulted in an average measured NO2 concentration up to 22% greater than that from co-located spectroscopic measurements. Thus, this interference has the potential to initiate regulatory action in areas that are close to non-attainment and may mislead atmospheric photochemical models used to assess control strategies for photochemical oxidants.

  2. Food contact surfaces coated with nitrogen-doped titanium dioxide: effect on Listeria monocytogenes survival under different light sources

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, D.; Teixeira, P. [Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Tavares, C.J. [Center of Physics, University of Minho, Campus de Azurém, 4800-058 Guimarães (Portugal); Azeredo, J., E-mail: jazeredo@deb.uminho.pt [Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga (Portugal)

    2013-04-01

    Improvement of food safety is a very important issue, and is on the basis of production and application of new/modified food contact surfaces. Titanium dioxide (TiO{sub 2}) and, more recently, nitrogen-doped titanium dioxide (N-TiO{sub 2}) coatings are among the possible forms to enhance food contact surfaces performance in terms of higher hygiene and easier sanitation. In this context, the present work aimed at evaluating the bactericidal activity of an N-TiO{sub 2} coating on glass and stainless steel under two different sources of visible light – fluorescent and incandescent – and ultraviolet (UV) irradiation. Listeria monocytogenes was chosen as representative of major foodborne pathogens and its survival was tested on N-TiO{sub 2} coated coupons. In terms of survival percentage, good results were obtained after exposure of coated surfaces to all light types since, apart from the value obtained after exposing glass to fluorescent light (56.3%), survival rates were always below 50%. However, no effective disinfection was obtained, given that for a disinfectant or sanitizing agent to be claimed as effective it needs to be able to promote at least a 3-log reduction of the microbial load, which was not observed for any of the experimental conditions assessed. Even so, UV irradiation was the most successful on eliminating cells on coated surfaces, since the amount of bacteria was reduced to 1.49 × 10{sup 6} CFU/ml on glass and 2.37 × 10{sup 7} on stainless steel. In contrast, both visible light sources had only slightly decreased the amount of viable cells, which remained in the range of 8 log CFU/ml. Hence, although some bactericidal effect was accomplished under visible light, UV was the most effective light source on promoting photocatalytic reactions on N-TiO{sub 2} coated coupons and none of the experimental conditions have reached a satisfactory disinfection level. Thus, this surface coating needs further research and improvement in order to become truly

  3. Food contact surfaces coated with nitrogen-doped titanium dioxide: effect on Listeria monocytogenes survival under different light sources

    Science.gov (United States)

    Rodrigues, D.; Teixeira, P.; Tavares, C. J.; Azeredo, J.

    2013-04-01

    Improvement of food safety is a very important issue, and is on the basis of production and application of new/modified food contact surfaces. Titanium dioxide (TiO2) and, more recently, nitrogen-doped titanium dioxide (N-TiO2) coatings are among the possible forms to enhance food contact surfaces performance in terms of higher hygiene and easier sanitation. In this context, the present work aimed at evaluating the bactericidal activity of an N-TiO2 coating on glass and stainless steel under two different sources of visible light - fluorescent and incandescent - and ultraviolet (UV) irradiation. Listeria monocytogenes was chosen as representative of major foodborne pathogens and its survival was tested on N-TiO2 coated coupons. In terms of survival percentage, good results were obtained after exposure of coated surfaces to all light types since, apart from the value obtained after exposing glass to fluorescent light (56.3%), survival rates were always below 50%. However, no effective disinfection was obtained, given that for a disinfectant or sanitizing agent to be claimed as effective it needs to be able to promote at least a 3-log reduction of the microbial load, which was not observed for any of the experimental conditions assessed. Even so, UV irradiation was the most successful on eliminating cells on coated surfaces, since the amount of bacteria was reduced to 1.49 × 106 CFU/ml on glass and 2.37 × 107 on stainless steel. In contrast, both visible light sources had only slightly decreased the amount of viable cells, which remained in the range of 8 log CFU/ml. Hence, although some bactericidal effect was accomplished under visible light, UV was the most effective light source on promoting photocatalytic reactions on N-TiO2 coated coupons and none of the experimental conditions have reached a satisfactory disinfection level. Thus, this surface coating needs further research and improvement in order to become truly effective against foodborne pathogens and

  4. Effects of acupuncture on contents of nitrogen monoxide and nitrogen monoxide synthase in the hippocampus of obese rats%针刺对肥胖大鼠海马组织一氧化氮含量和一氧化氮合酶活性的影响

    Institute of Scientific and Technical Information of China (English)

    刘志诚; 孙凤岷; 袁锦虹; 徐炳国; 马燕; 姜军作; 衣运玲

    2004-01-01

    BACKGROUND: The abnormality of the content of nitrogen monoxide (NO)and activity of nitrogen monoxide synthase(NOS) may be an important factor of obesity. It has been known that the mechanisms of acupuncture treating obesity are related to nervous and neurohumoral regulation. What is the regulating effect of acupuncture on NO content and NOS activity in hippocampal tissues?OBJECTIVE: To study the effects of acupuncture on the content of NO and NOS, and further investigate central nervous functional mechanism of reducing weight by acupuncture.DESIGN: Self-controlled and mutual controlled experiment.SETTING: Acupuncture Institute of Second Clinical Medical College, Nanjing University of Traditional Chinese Medicine, and Department of Reproduction Medicine, Nanjing College for Population Programmed Management.PARTICIPANTS: This experiment was carried out in the Acupuncture Institute of Second Clinical Medical College; One-month old male SD rats just in allactation, weighing 50 -70 g were provided by the Animal Experiment Center of General Hospital of Nanjing Military Area Command[Certification No. SYXK(Su) 2002-0017], and the animals were in the clean grade (Certification No. Su Animal Quality 970101 ).INTERVENTIONS: Rats fed with ordinary diet were in the normal group.Experimental obese rats models were randomly divided as control group and acupuncture group, 6 in each. Rats in the acupuncture group were given acupuncture treatment for 14 days, and rats in the normal and control groups were put into rat fixation-machine for 15 minutes, lasting for 14 days. Body mass, body lipid and contents of NO and NOS in hippocampal tissues in obese rats before and after acupuncture were observed with nervous biochemical technology.Effect of acupuncture on NO and NOS contents in hippocampal tissue of and Lee's index in hippocampal tissue of obese rats.RESULTS: The body mass[ (458.33 ± 7.43)g], Lee' s index (302.23± 4. 11 ) and body fat content of obesity were all significantly

  5. Improvements in the profiles and distributions of nitric acid and nitrogen dioxide with the LIMS version 6 dataset

    Directory of Open Access Journals (Sweden)

    E. Remsberg

    2010-05-01

    Full Text Available The quality of the Nimbus 7 Limb Infrared Monitor of the Stratosphere (LIMS nitric acid (HNO3 and nitrogen dioxide (NO2 profiles and distributions of 1978/1979 are described after their processing with an updated, Version 6 (V6 algorithm and subsequent archival in 2002. Estimates of the precision and accuracy of both of those species are developed and provided herein. The character of the V6 HNO3 profiles is relatively unchanged from that of the earlier LIMS Version 5 (V5 profiles, except in the upper stratosphere where the interfering effects of CO2 are accounted for better with V6. The accuracy of the retrieved V6 NO2 is also significantly better in the middle and upper stratosphere, due to improvements in its spectral line parameters and in the reduced biases for the accompanying V6 temperature and water vapor profiles. As a result of these important updates, there is better agreement with theoretical calculations for profiles of the HNO3/NO2 ratio, day-to-night NO2 ratio, and with estimates of the production of NO2 in the mesosphere and its descent to the upper stratosphere during polar night. In particular, the findings for middle and upper stratospheric NO2 should also be more compatible with those obtained from more recent satellite sensors because the effects of the spin-splitting of the NO2 lines are accounted for now with the LIMS V6 algorithm. The improved precisions and more frequent retrievals of the LIMS profiles along their orbit tracks provide for better continuity and detail in map analyses of these two species on pressure surfaces. It is judged that the chemical effects of the oxides of nitrogen on ozone can be studied quantitatively throughout the stratosphere with the LIMS V6 data.

  6. Effect of nitrogen dioxide and other combustion products on asthmatic subjects in a home-like environment.

    Science.gov (United States)

    Salome, C M; Brown, N J; Marks, G B; Woolcock, A J; Johnson, G M; Nancarrow, P C; Quigley, S; Tiong, J

    1996-05-01

    Nitrogen dioxide (NO2) is one of a number of nitrogen compounds that are by-products of combustion and occur in domestic environments following the use of gas or other fuels for heating and cooking. In this study, we examined the effect of two levels of NO2 on symptoms, lung function and airway hyperresponsiveness (AHR) in asthmatic adults and children. In addition, in the same subjects, we examined the effects of the same levels of NO2 mixed with combustion by-products from a gas space heater. The subjects were nine adults, aged 19-65 yrs, and 11 children, aged 7-15 yrs, with diagnosed asthma which was severe enough to require daily medication. All subjects had demonstrable AHR to histamine. Exposures were for 1 h on five separate occasions, 1 week apart, to: 1) ambient air, drawn from outside the building; 2) 0.3 parts per million (ppm) NO2 in ambient air; 3) 0.6 ppm NO2 in ambient air; 4) ambient air+combustion by-products+NO2 to give a total of 0.3 ppm; and 5) ambient air+combustion by-products+NO2 to give a total of 0.6 ppm. Effects were measured as changes in lung function and symptoms during and 1 h after exposure, in AHR 1 h and 1 week after exposure, and in lung function and symptoms during the week following exposure. Exposure to NO2 either in ambient air or mixed with combustion by-products from a gas heater, had no significant effect on symptoms or lung function in adults or in children. There was a small, but statistically significant, increase in AHR after exposure to 0.6 ppm NO2 in ambient air. However, there was no effect of 0.6 ppm NO2 on AHR when the combustion by-products were included in the test atmosphere nor of 0.3 ppm NO2 under either exposure condition. We conclude that a 1 h exposure to 0.3 or 0.6 ppm NO2 has no clinically important effect on the airways of asthmatic adults or children, but that 0.6 ppm may cause a slight increase in airway hyperresponsiveness.

  7. Soil carbon dioxide emission from intensively cultivated black soil in Northeast China. Nitrogen fertilization effect

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Kang [Chinese Academy of Sciences, Nanjing (China). State Key Lab. of Soil and Sustainable Agriculture; Graduate University of Chinese Academy of Sciences, Beijing (China); Ding, Weixin; Cai, Zucong [Chinese Academy of Sciences, Nanjing (China). State Key Lab. of Soil and Sustainable Agriculture; Wang, Yufeng; Zhang, Xilin; Zhou, Baoku [Heilongjiang Academy of Agricultural Sciences, Harbin (China). Inst. of Soil and Fertilizer

    2012-08-15

    Purpose: The aim of this study was to understand the effect of nitrogen fertilization on soil respiration and native soil organic carbon (SOC) decomposition and to identify the key factor affecting soil respiration in a cultivated black soil. Materials and methods: A field experiment was conducted at the Harbin State Key Agroecological Experimental Station, China. The study consisted of four treatments: unplanted and N-unfertilized soil (U0), unplanted soil treated with 225 kg N ha{sup -1} (UN), maize planted and N-unfertilized soil (P0), and planted soil fertilized with 225 kg N ha{sup -1} (PN). Soil CO{sub 2} and N{sub 2}O fluxes were measured using the static closed chamber method. Results and discussion: Cumulative CO{sub 2} emissions during the maize growing season with the U0, UN, P0, and PN treatments were 1.29, 1.04, 2.30 and 2.27 Mg C ha{sup -1}, respectively, indicating that N fertilization significantly reduced the decomposition of native SOC. However, no marked effect on soil respiration in planted soil was observed because the increase of rhizosphere respiration caused by N addition was counteracted by the reduction of native SOC decomposition. Soil CO{sub 2} fluxes were significantly affected by soil temperature but not by soil moisture. The temperature sensitivity (Q{sub 10}) of soil respiration was 2.16-2.47 for unplanted soil but increased to 3.16-3.44 in planted soil. N addition reduced the Q{sub 10} of native SOC decomposition possibly due to low labile organic C but increased the Q{sub 10} of soil respiration due to the stimulation of maize growth. The estimated annual CO{sub 2} emission in N-fertilized soil was 1.28 Mg C ha{sup -1} and was replenished by the residual stubble, roots, and exudates. In contrast, the lost C (1.53 Mg C ha{sup -1}) in N-unfertilized soil was not completely supplemented by maize residues, resulting in a reduction of SOC. Although N fertilization significantly increased N{sub 2}O emissions, the global warming potential

  8. Stratospheric ozone and nitrogen dioxide total column and vertical profiles in southern Portugal during 2004-2007

    Science.gov (United States)

    Bortoli, D.; Silva, A. M.; Roselli, D.; Giovanelli, G.

    2007-10-01

    The SPATRAM (Spectrometer for Atmospheric TRAcers Monitoring) instrument has been developed by the collaboration between CGE-UE, ISAC-CNR and ENEA. SPATRAM is a multi-purpose UV-Vis-NIR spectrometer (250-950 nm). It is installed at the Observatory of the CGE since April 2004 and actually it is utilized to carry-out measurements of the zenith scattered radiation, the so-called "Passive mode", in order to retrieve-by application of DOAS (Differential Optical Absorption Spectroscopy) methodology-the vertical content of some atmospheric tracers such as Ozone (O3) and Nitrogen Dioxide (NO2). For the continuous NO2 monitoring the 425-455 nm spectral region is investigated. For the Ozone retrieval the spectral interval 320-340 nm is chosen. In this study, after a brief description of the instrument, a short explanation of the DOAS methodology and of the inversion algorithms used for the determination of the vertical distribution of the some atmospheric compounds are provided. The obtained results in terms of diurnal and seasonal variation of O3 and NO2 total column are presented. The measurements are in good agreement with the photochemical theory of NO2 and O3, showing the maximum values during the summer season and the minimum during the winter. In addition the application, to the output of the DOAS program, of sophisticated inversion schemes, using the Air Mass Factor (AMF) matrix as the kernel of the inversion algorithm, allowed for the determination of vertical distribution of some atmospheric tracers. The results obtained for NO2 and O3 are presented and discussed.

  9. Atmospheric protein chemistry influenced by anthropogenic air pollutants: nitration and oligomerization upon exposure to ozone and nitrogen dioxide.

    Science.gov (United States)

    Liu, Fobang; Lakey, Pascale S J; Berkemeier, Thomas; Tong, Haijie; Kunert, Anna Theresa; Meusel, Hannah; Cheng, Yafang; Su, Hang; Fröhlich-Nowoisky, Janine; Lai, Senchao; Weller, Michael G; Shiraiwa, Manabu; Pöschl, Ulrich; Kampf, Christopher J

    2017-08-24

    The allergenic potential of airborne proteins may be enhanced via post-translational modification induced by air pollutants like ozone (O3) and nitrogen dioxide (NO2). The molecular mechanisms and kinetics of the chemical modifications that enhance the allergenicity of proteins, however, are still not fully understood. Here, protein tyrosine nitration and oligomerization upon simultaneous exposure of O3 and NO2 were studied in coated-wall flow-tube and bulk solution experiments under varying atmospherically relevant conditions (5-200 ppb O3, 5-200 ppb NO2, 45-96% RH), using bovine serum albumin as a model protein. Generally, more tyrosine residues were found to react via the nitration pathway than via the oligomerization pathway. Depending on reaction conditions, oligomer mass fractions and nitration degrees were in the ranges of 2.5-25% and 0.5-7%, respectively. The experimental results were well reproduced by the kinetic multilayer model of aerosol surface and bulk chemistry (KM-SUB). The extent of nitration and oligomerization strongly depends on relative humidity (RH) due to moisture-induced phase transition of proteins, highlighting the importance of cloud processing conditions for accelerated protein chemistry. Dimeric and nitrated species were major products in the liquid phase, while protein oligomerization was observed to a greater extent for the solid and semi-solid phase states of proteins. Our results show that the rate of both processes was sensitive towards ambient ozone concentration, but rather insensitive towards different NO2 levels. An increase of tropospheric ozone concentrations in the Anthropocene may thus promote pro-allergic protein modifications and contribute to the observed increase of allergies over the past decades.

  10. Effect of nitrogen dioxide on synthesis of inflammatory cytokines expressed by human bronchial epithelial cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Devalia, J.L.; Campbell, A.M.; Sapsford, R.J.; Rusznak, C.; Quint, D.; Godard, P.; Bousquet, J.; Davies, R.J. (St. Bartholomew' s Hospital, London (United Kingdom))

    1993-09-01

    Although studies of nitrogen dioxide (NO2) inhalation, in both animals and humans, have demonstrated that this agent can cause epithelial cell damage and inflammation of the airway epithelium, the mechanisms underlying these effects are not well understood. We have cultured human bronchial epithelial cells, as explant cultures from surgical tissue, and studied these firstly from their ability to constitutively synthesize specific proinflammatory cytokines and then investigated the effect of exposure to NO2 on the generation of these cytokines. Constitutive synthesis of cytokines was evaluated by analysis of both the expression of the mRNA for interleukin (IL)-1 beta, IL-4, IL-8, granulocyte/macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma), by the polymerase chain reaction (PCR), and by immunocytochemical staining for the presence of cell-associated IL-1 beta, IL-8, GM-CSF, TNF-alpha, and IFN-gamma, using specific monoclonal and polyclonal antibodies directed towards these cytokines. Release of IL-4, IL-8, GM-CSF, TNF-alpha, and IFN-gamma following exposure to 5% CO2 in air or 400 ppb and 800 ppb NO2 for 6 h was investigated by enzyme-linked immunosorbent assay. PCR demonstrated that the human bronchial epithelial cells expressed the mRNA for IL-1 beta, IL-8, GM-CSF, and TNF-alpha but not for IL-4 and IFN-gamma. Immunocytochemical staining confirmed the presence of endogenous IL-1 beta, IL-8, GM-CSF, and TNF-alpha.

  11. Impact of emissions and +2 °C climate change upon future ozone and nitrogen dioxide over Europe

    Science.gov (United States)

    Watson, Laura; Lacressonnière, Gwendoline; Gauss, Michael; Engardt, Magnuz; Andersson, Camilla; Josse, Béatrice; Marécal, Virginie; Nyiri, Agnes; Sobolowski, Stefan; Siour, Guillaume; Szopa, Sophie; Vautard, Robert

    2016-10-01

    The evolution of ozone and nitrogen dioxide over Europe between the present day and a future period with a +2 °C global warming relative to the pre-industrial climate was studied using four offline chemistry transport models, each driven by a different climate model. Given the recent outcome of the COP21 negotiations, understanding the implications of climate change around the +2 °C threshold has never been more pressing or relevant. One of the objectives of this study was to show how changes in anthropogenic emissions and +2 °C climate change are expected to affect future air quality, which may have important implications upon human health. It was found that a +2 °C climate change alone was responsible for a modest, and not statistically significant, increase in surface O3 concentrations (of between -0.1-0.8 ppb in the summer averaged over the European domain) compared to the present climate. Two different emission scenarios were used for the future time period in order to provide an estimate of the extent of air pollution reductions that could occur if (a) all currently planned air quality legislation is implemented and (b) all maximum technologically feasible emission reductions are implemented. The results showed that summer O3 could be reduced by between 4 and 5 ppb under a current legislation scenario, with at least 3 ppb of further reductions under the maximum mitigated scenario. Calculations of summer ozone enhancement were used as a metric to analyse the results after having removed background ozone level changes. In conclusion it was found that future air quality on a regional scale will depend upon the implementation of effective emission reduction policy; the positive effects of which should not be hindered by a +2 °C global warming.

  12. A longitudinal study of indoor nitrogen dioxide levels and respiratory symptoms in inner-city children with asthma.

    Science.gov (United States)

    Hansel, Nadia N; Breysse, Patrick N; McCormack, Meredith C; Matsui, Elizabeth C; Curtin-Brosnan, Jean; Williams, D'Ann L; Moore, Jennifer L; Cuhran, Jennifer L; Diette, Gregory B

    2008-10-01

    The effect of indoor nitrogen dioxide concentrations on asthma morbidity among inner-city preschool children is uncertain. Our goal was to estimate the effect of indoor NO2 concentrations on asthma morbidity in an inner-city population while adjusting for other indoor pollutants. We recruited 150 children (2-6 years of age) with physician-diagnosed asthma from inner-city Baltimore, Maryland. Indoor air was monitored over a 72-hr period in the children's bedrooms at baseline and 3 and 6 months. At each visit, the child's caregiver completed a questionnaire assessing asthma symptoms over the previous 2 weeks and recent health care utilization. Children were 58% male, 91% African American, and 42% from households with annual income gas stove and the use of a space heater or oven/stove for heat were independently associated with higher NO2 concentrations. Each 20-ppb increase in NO2 exposure was associated significantly with an increase in the number of days with limited speech [incidence rate ratio (IRR) = 1.15; 95% confidence interval (CI), 1.05-1.25], cough (IRR = 1.10; 95% CI, 1.02-1.18), and nocturnal symptoms (IRR = 1.09; 95% CI, 1.02-1.16), after adjustment for potential confounders. NO2 concentrations were not associated with increased health care utilization. Higher indoor NO2 concentrations were associated with increased asthma symptoms in preschool inner-city children. Interventions aimed at lowering NO2 concentrations in inner-city homes may reduce asthma morbidity in this vulnerable population.

  13. Ozone and nitrogen dioxide total columns and vertical distributions at the Italian Antarctic station during 1996-2008

    Science.gov (United States)

    Bortoli, D.; Ravegnani, F.; Giovanelli, G.; Kostadinov, Iv.; Petritoli, A.; Masieri, S.; Premuda, M.; Martins, H. T.; Silva, A. M.

    2009-09-01

    The GASCOD (Gas Analyzer Spectrometer Correlating Optical Differences) has been installed at the 'Mario Zucchelli' Antarctic station since 1996. It measures the zenith sky radiation in the 405-465 nm spectral range in unattended and automatic mode. The application to the spectral data of the DOAS (Differential Optical Absorption Spectroscopy) algorithms coupled with a Radiative Transfer Model (RTM) for the computation of the Air Mass Factor (AMF), allows for the retrieval of the total content of the main absorber in this spectral range, namely nitrogen dioxide (NO2). Moreover, the application of sophisticated inversion schemes to the output of the DOAS program, using the AMF matrix as the kernel of the inversion algorithm, permits the determination of the vertical distribution of the above mentioned compound. The full dataset of the spectral data obtained with GASCOD during the period 1996-2008, was re-analyzed with a modified version of the software tool previously utilized. Even if the spectral range examined with GASCOD is not the most favorable for the ozone total column and vertical profile retrieval, the re-processing of the spectral data allowed for the determination of the total ozone columns (TOC). The uncertainties range from 4% to 8% for ozone and 3% to 6% for NO2. The peculiar features of the seasonal variation of NO2 total columns (i.e. the normal decreasing during the austral fall and the irregular growing towards the summer month) are presented and discussed. The confirmations of the significant declining of the ozone total columns during the 'Ozone Hole' periods (mid-August to mid-October) are reported. The vertical distributions obtained for the preceding atmospheric compounds are shown and examined.

  14. Slant column MAX-DOAS measurements of nitrogen dioxide, formaldehyde, glyoxal and oxygen dimer in the urban environment of Athens

    Science.gov (United States)

    Gratsea, Myrto; Vrekoussis, Mihalis; Richter, Andreas; Wittrock, Folkard; Schönhardt, Anja; Burrows, John; Kazadzis, Stelios; Mihalopoulos, Nikos; Gerasopoulos, Evangelos

    2016-06-01

    Slant column (SC) densities of nitrogen dioxide (NO2), formaldehyde (HCHO), glyoxal (CHOCHO) and oxygen dimer (O4) were successfully retrieved for the first time in Athens, by using spectral measurements from a ground-based multi-azimuth Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) system. The data span the period from October 2012 to March 2014 and measurements were conducted at NOA's (National Observatory of Athens) station in Penteli (38.0°N, 23.9°E, 527 m a.s.l.) at eight azimuth angles and eight off-axis elevation angles. The SCNO2, SCHCHO and SCCHOCHO measurements at +1ο elevation angle, pointing towards the urban area, range from 0.6 to 24·1016, 0.8-9.6·1016 and 0.3-5.2·1015 molec cm-2 (mean daily values throughout the whole period), respectively. Seasonal modulation characterised by summertime maximum and wintertime minimum was observed for HCHO and CHOCHO, while for NO2 the maximum values were recorded during winter. Changes in the diurnal variability of all trace gases with season and day of the week are investigated suggesting a strong link to primary anthropogenic sources for NO2 and a weaker one, compared to photochemistry, for HCHO and CHOCHO. In addition, the impact of the reduced anthropogenic emissions during weekends on the measured SC values was quantified and 30%-50% lower SCNO2 values were found during weekends. The contribution of local urban emissions to the overall recorded amounts of the selected species was assessed. Using meteorological data from NOA's station in Penteli, the impact of the local circulation patterns on the SC levels was estimated, and a strong relation between western wind direction, which is related to the industrial area, and enhanced SC measurements was found.

  15. The chemistry of subcritical water reactions of a hardwood derived lignin and lignin model compounds with nitrogen, hydrogen, carbon monoxide and carbon dioxide

    Science.gov (United States)

    Hill Bembenic, Meredith A.

    Biofuels, like cellulosic ethanol, may only be cost effective if the lignin byproduct is upgraded to value-added products. However, lignin's inherent aromatic structure and interunit crosslinkages hinder effective conversion. High temperature H2O is considered for lignin conversion, because H2O exhibits unusual properties at higher temperatures (particularly at its supercritical point of 374°C and 3205 psi) including a decreased ion product and a decreased static dielectric constant (similar to those of polar organic solvents at room temperature) such that there is a high solubility for organic compounds, like lignin. Much of the research concerning lignin and supercritical H2O has focused on further decomposition to gases (e.g., H2, CH4, and CO2) where nearly no char formation is expected in the presence of a catalyst. However, the conditions required for supercritical H2O are difficult to maintain, catalysts can be expensive, and gases are not favorable to the current liquid fuel infrastructure. Reactions using Organosolv lignin, subcritical H2O (365°C) and various industrial gases (N2, H2, CO, and CO2 at an initial pressure of 500 psi) for 30 min. were examined to determine both lignin's potential to generate value-added products (e.g., monomer compounds and methanol) and the role (if any) of the H2O and the gases during the reactions. The behavior of H2O at reaction temperature and pressure is expected to be similar to the behavior of supercritical H 2O without the need to maintain supercritical conditions. Different characterization techniques were used for the products collected including primarily GC/FID-TCD of the evolved gases, GC/MS analysis of the organic liquids, solid phase microextraction analysis of the water, and solid state 13C-NMR analysis of the residues. The reactor pressure at temperature was shown to influence the reactivity of the H2O and lignin, and the highest conversions (≈54--62%) were obtained when adding a gas. However, the collected solids from the CO reactions appeared to be the most reacted (i.e., the most changed from the unreacted lignin) according to solid state 13C-NMR analysis, and the widest variety of products (methoxy-substituted phenolic compounds) were obtained when using CO according to GC/MS analysis. Therefore, reactions with CO were completed that varied the initial reaction pressure (300, 500 and 800 psi) in order to elucidate the effects of CO pressure. Similar conversion (≈54--58%) and DCM-soluble liquid product yields (≈53--62%) were obtained for the different pressure reactions, but the reactions with an initial pressure of 500 psi had the greatest change in aromaticity from the unreacted lignin. Additional reactions between Organosolv lignin and H2O with CO (initial pressure of 500 psi) were conducted where the reaction time was varied (15, 30 and 60 min.) to determine the effect of reaction time. Longer reaction time (60 min.) appeared to inhibit conversion to low molecular weight compounds (i.e., conversion and DCM-soluble yields were lower at ≈53% and ≈28%, respectively). Solid state 13C-NMR of collected residues also showed that there are losses in carbons representative of both guaiacyl and syringyl components as reaction time increases, which may indicate that methoxy groups are being cleaved or the products are reacting with each other (i.e., repolymerization) to form high molecular weight compounds as reaction time is increased. The role of H2O and the gases during the baseline reactions and the expanded CO reactions is not intuitive based on the results, so reactions with lignin model compounds (i.e., aromatic aldehydes represented by vanillin and syringaldehyde, aromatic ketones represented by acetovanillone and acetosyringone, and aromatic ethers represented by dibenzyl ether and 2-phenethyl phenyl ether) were completed to study this. From these results, the suggested reaction pathway of Organosolv lignin reactions in subcritical H2O with and without added pressure is: 1) cleavage of ethers (via hydrolysis) to form smaller methoxy-substituted phenolic monomers with aldehyde- or ketone-substituents representative of lignin monomers; 2) cleavage of the methoxy-, aldehyde- and/or ketone-substituents to form primarily methoxy-substituted phenolic monomers; 3) rearrangement of these phenolic monomers due to the enhanced pressure at reaction temperature; 4) formation of oligomers due to interaction amongst the methoxy-substituted phenolic monomers, which is also due to the enhanced pressure at reaction temperature; and 5) repolymerization of the monomers and oligomers to form high molecular weight compounds (i.e., longer reactions times or different pressures seemed to enhance these reactions). Under these conditions, depolymerization seems to be the dominant reaction pathway versus repolymerization. Reactions with lignin and H2O at 365°C have not been previously reported nor has the reaction chemistry for lignin depolymerization at these conditions been established. The results with lignin (or lignin model compounds), subcritical H2O and CO also show that the desired product slate can be modified with different pressure and time conditions. In particular, increasing reaction time (from 15 to 60 min.) caused lignin conversion to decrease, and the products appeared to be reacting with each other. However, the longer reaction time also showed that more methanol is generated (along with more solids).

  16. Separation of carbon dioxide from nitrogen or methane by supported ionic liquid membranes (SILMs): influence of the cation charge of the ionic liquid.

    Science.gov (United States)

    Hojniak, Sandra D; Khan, Asim Laeeq; Hollóczki, Oldamur; Kirchner, Barbara; Vankelecom, Ivo F J; Dehaen, Wim; Binnemans, Koen

    2013-12-05

    Supported ionic liquid membranes (SILMs) are promising tools for the separation of carbon dioxide from other gases. In this paper, new imidazolium, pyrrolidinium, piperidinium, and morpholinium ionic liquids with a triethylene glycol side chain and tosylate anions, as well as their symmetrical dicationic analogues, have been synthesized and incorporated into SILMs. The selectivities for CO2/N2 and CO2/CH4 separations have been measured. The selectivities exhibited by the dicationic ionic liquids are up to two times higher than the values of the corresponding monocationic ionic liquids. Quantum chemical calculations have been used to investigate the difference in the interaction of carbon dioxide with monocationic and dicationic ionic liquids. The reason for the increased gas separation selectivity of the dicationic ionic liquids is two-fold: (1) a decrease in permeance of nitrogen and methane through the ionic liquid layer, presumably due to their less favorable interactions with the gases, while the permeance of carbon dioxide is reduced much less; (2) an increase in the number of interaction sites for the interactions with the quadrupolar carbon dioxide molecules in the dicationic ionic liquids, compared to the monocationic analogues.

  17. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Estimates OCTOBER 13, 2015 Incidents, Deaths, and In-Depth Investigations Associated with Non-Fire Carbon Monoxide from Engine-Driven Generators and ... Engine-Driven Tools, 2004–2014 JANUARY 08, 2015 Non-Fire Carbon Monoxide Deaths Associated with the Use of Consumer Products 2011 Annual Estimates View All ... Inside CPSC Accessibility ...

  18. Regioselective Nitration of Inactive 4,4-Dibromobiphenyl with Nitrogen Dioxide and Molecular Oxygen over Zeolites: An Efficient Preparation of 4,4'-Dibromo-2-nitrobiphenyl

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei; Peng, Xinhua; Chen, Nan [Hefei Univ. of Technology, Hefei (China)

    2014-02-15

    In the presence of zeolites, 4,4'-dibromobiphenyl could be region-selectively nitrated by the action of nitrogen dioxide and molecular oxygen. The ratio of 4,4'-dibromo-2-nitrobiphenyl to 4,4'-dibromo-3-nitrobiphenyl could reach 14 in a high yield of 90%. Zeolites could be easily regenerated by heating and reused four times to give the results similar to those obtained with fresh catalyst. Compared with the classic nitration method, no nitric acid and sulfuric acid were used, which suggested that the method was an environmentally economic process.

  19. Neon-matrix spectroscopic and theoretical studies of the reactivity of titanium dimer with diatomic ligands: comparison of reactions with nitrogen and carbon monoxide.

    Science.gov (United States)

    Souvi, S M; Berkaïne, N; Alikhani, M E; Manceron, L

    2009-11-14

    The reactivity of diatomic titanium with molecular carbon monoxide has been investigated in solid neon at very low temperature. In contrast to the spontaneous reaction observed between Ti(2) and N(2), our results show that the formation of dititanium oxycarbide (OTi(2)C) from the condensation of effusive beams of Ti and CO in neon matrices involves several intermediate steps including one metastable intermediate. In the absence of electronic excitation, only formation of a Ti(2)(CO) complex occurs spontaneously during the reaction at 9 K of ground state Ti(2) and CO, as reported in solid argon by Xu, Jiang and Tsumori (Angew. Chem. Int. Ed., 2005, 44, 4338). However, during deposition or following electronic excitation, this species rearranges into a new species: the more stable, OTi(2)C oxycarbide form. Several low-lying excited states of OTi(2)C are also observed between 0.77 and 0.89 eV above the ground state, leading to a complex sequence of interacting vibronic transitions, merging into a broad continuum above 1 eV. Observations of Ti(2)(12)C(16)O, Ti(2)(13)C(16)O and Ti(2)(12)C(18)O and natural titanium isotopic data enable the identification of four fundamental vibrations in the ground electronic state and two others in the first two excited states. Quantum chemical calculations predict an open-shell (1)A(g) ground state with Ti-C and Ti-O distances close to 184 pm, and 91 degrees for the TiCTi and TiOTi bond angles, and give fundamental frequencies in good agreement with observation. The reaction paths of the Ti(2) + N(2) --> Ti(2)N(2) and Ti(2) + CO --> Ti(2)(CO) --> OTi(2)C have been investigated and a reaction scheme is proposed accounting for the similarities in nature and properties of the final products, as well as explaining the observation of a coordination complex with Ti(2) only in the case of the carbonyl ligand.

  20. Monitoring of atmospheric ozone and nitrogen dioxide over the south of Portugal by ground-based and satellite observations.

    Science.gov (United States)

    Bortoli, Daniele; Silva, Ana Maria; Costa, Maria João; Domingues, Ana Filipa; Giovanelli, Giorgio

    2009-07-20

    The SPATRAM (Spectrometer for Atmospheric TRAcers Monitoring) instrument has been developed as a result of the collaboration between CGE-UE, ISAC-CNR and Italian National Agency for New Technologies, Energy and the Environment (ENEA). SPATRAM is a multi-purpose UV-Vis-scanning spectrometer (250 - 950 nm) and it is installed at the Observatory of the CGE, in Evora, since April 2004. A brief description of the instrument is given, highlighting the technological innovations with respect to the previous version of similar equipment. The need for such measurements automatically taken on a routine basis in south-western European regions, specifically in Portugal, has encouraged the development and installation of the equipment and constitutes a major driving force for the present work. The main features and some improvements introduced in the DOAS (Differential Optical Absorption Spectroscopy) algorithms are discussed. The results obtained applying DOAS methodology to the SPATRAM spectrometer measurements of diffused spectral sky radiation are presented in terms of diurnal and seasonal variations of nitrogen dioxide (NO(2)) and ozone (O(3)). NO(2) confirms the typical seasonal cycle reaching the maximum of (6.5 +/- 0.3) x 10(+15) molecules cm(-2) for the sunset values (PM), during the summer season, and the minimum of (1.55 +/- 0.07) x 10(+15) molecules cm(-2) for the sunrise values (AM) in winter. O(3) presents the maximum total column of (433 +/- 5) Dobson Unit (DU) in the spring season and the minimum of (284 +/- 3) DU during the fall period. The huge daily variations of the O(3) total column during the spring season are analyzed and discussed. The ground-based results obtained for NO(2) and O(3) column contents are compared with data from satellite-borne equipment (GOME - Global Ozone Monitoring Experiment; SCIAMACHY - Scanning Imaging Absorption Spectrometer for Atmospheric CHartographY; TOMS - Total Ozone Monitoring Spectrometer) and it is shown that the two data

  1. Estimation of surface nitrogen dioxide mixing ratio using the OMI NO2 tropospheric column data measured in Korea

    Science.gov (United States)

    Kim, Daewon; Lee, Hanlim; Hong, Hyunkee; Park, Junsung

    2017-04-01

    We, for the first time, estimated daily and monthly surface nitrogen dioxide (NO2) volume mixing ratio (VMR) using three empirical models (Model-1, Model-2, and Model-3) with NO2 tropospheric vertical column density (OMI-Trop NO2 VCD) data obtained from Ozone Monitoring Instrument (OMI) in four metropolitan cities: Daejeon, Gwangju, Gyeonggi, and Seoul in South Korea for the period between 2006 and 2014. The performance of those empirical linear models was evaluated via comparison with the surface NO2 VMR data obtained from in-situ measurements(in-situ NO2 VMR) for the two years validation period. Model-1 is a linear regression equation between OMI-Trop NO2 VCD and in-situ NO2 VMR, whereas Model-2 is a linear regression equation which incorporate boundary layer height (BLH) obtained from Atmospheric Infrared Sounder (AIRS). Model-3 is a multiple linear regression equation. The monthly mean surface NO2 VMRs estimated by Model-2 showed good agreements with those of in-situ measurements. We found that correlation coefficients (R) between the estimated monthly mean surface NO2 VMRs from Model-2 and in-situ NO2 VMRs range from 0.70 to 0.82. The best correlation (R = 0.82) was found in Gwangju, while the poorest correlation (R = 0.70) was found in the western part of Seoul. In terms of the daily NO2 estimation, the highest correlations were found between the daily surface NO2 VMRs estimated by Model-3 and in-situ NO2 VMRs (0.62 < R < 0.90). The best correlation (R = 0.90) was found in the western part of Seoul, while the poorest correlation (R = 0.62) was found in Gwangju. We also discussed the performance of these empirical models for surface NO2 VMR estimation with respect to other statistical data such as root mean square error, mean bias, mean absolute error, and percent difference. This present study shows a possibility of estimating surface NO2 VMR using the satellite measurement.

  2. Social factors associated with nitrogen dioxide (NO2) exposure during pregnancy: the INMA-Valencia project in Spain.

    Science.gov (United States)

    Llop, Sabrina; Ballester, Ferran; Estarlich, Marisa; Iñiguez, Carmen; Ramón, Rosa; Gonzalez, Ma Carmen; Murcia, Mario; Esplugues, Ana; Rebagliato, Marisa

    2011-03-01

    Numerous studies have focused on the effects of exposure to air pollution on health; however, certain subsets of the population tend to be more exposed to such pollutants depending on their social or demographic characteristics. In addition, exposure to toxicants during pregnancy may play a deleterious role in fetal development as fetuses are especially vulnerable to external insults. The present study was carried out within the framework of the INMA (Infancia y Medio Ambiente or Childhood and the Environment) multicenter cohort study with the objective of identifying the social, demographic, and life-style factors associated with nitrogen dioxide (NO(2)) exposure in the subjects in the cohort. The study comprised 785 pregnant women who formed part of the INMA cohort in Valencia, Spain. Outdoor levels of NO(2) were measured at 93 sampling sites spread over the study area during four different sampling periods lasting 7 days each. Multiple regression models were used for mapping outdoor NO(2) throughout the area. Individual exposure was assigned as: 1) the estimated outdoor NO(2) levels at home, and 2) the average of estimated outdoor NO(2) levels at home and work, weighted according to the time spent in each environment. The subjects' socio-demographic and life-style information was obtained through a questionnaire. In the multiple linear analyses, the outdoor NO(2) levels assigned to each home were taken to be the dependent variable. Other variables included in the model were: age, country of origin, smoking during pregnancy, parity, season of the year, and social class. These same variables remained in the model when the dependent variable was changed to the NO(2) levels adjusted for the subjects' time-activity patterns. We found that younger women, those coming from Latin American countries, and those belonging to the lower social strata were exposed to higher NO(2) levels, both as measured outside their homes as well as when time-activity patterns were taken

  3. An ex post cost-benefit analysis of the nitrogen dioxide air pollution control program in Tokyo.

    Science.gov (United States)

    Voorhees, A S; Araki, S; Sakai, R; Sato, H

    2000-03-01

    The benefits and costs of past nitrogen dioxide (NO2) control policies were calculated for Tokyo, Japan, using environmental, economic, political, demographic, and medical data from 1973 to 1994. The benefits of NO2 control were estimated as medical expenses and lost work time due to hypothetical no-control air concentrations of NO2. Direct costs were calculated as annualized capital expenditures and 1 year's operating costs for regulated industries plus governmental agency expenses. The major findings were as follows: (1) Using Tokyo's average medical cost of pollution-related illness, the best net estimate of the avoided medical costs due to incidence of phlegm and sputum in adults was 730 billion yen ($6.08 billion; 1 U.S. dollar = 120 yen). (2) The best net estimate of the avoided medical costs due to incidence of lower respiratory illness in children was 93 billion yen ($775 million). (3) Using Tokyo's average duration of pollution-related illness and average wages, the best net estimate of the avoided costs of lost wages in workers was 760 billion yen ($6.33 billion). (4) The best net estimate of the avoided costs of lost wages in mothers caring for their sick children was 100 billion yen ($833 million). (5) Using Tokyo-specific data, the best net costs were estimated as 280 billion yen ($2.33 billion). (6) Using human health and productivity benefits, and annualized capital cost and operating cost estimates, the best net benefits-to-costs ratio was 6:1 (upper limit 44:1; lower limit 0.3:1). Benefit calculations were sensitive to assumptions of mobile source emissions and certain health impacts that were not included. Cost calculations were highly dependent on assumptions of flue gas volume and fuel use. For comparative purposes, we identified other studies for air pollution-related illness. Assumptions that formed the basis for most of the inputs in the present study, such as duration of illness, medical treatment costs, per person illness in children, and

  4. Assessing theEffects of Nitrogen Dioxide in Urban Air on Health of West and Southwest Cities of Iran

    Directory of Open Access Journals (Sweden)

    Zallaghi

    2014-10-01

    Full Text Available Background Nitrogen dioxide (NO2 is a corrosive, strong oxidant and a physiologic stimulant of lower respiratory tract. Every human being inhales an average of 10-m3 air per day; therefore, assessment of the effect of inhaled air on health is a vital issue. The main source NO2 in urban regions is intra-urban public transport system. The annual average of determined air quality for NO2 is 40 μg/m3. Objectives The present study aimed to estimate and compare epidemiologic indices attributed to the pollutant NO2 in the urban air of southwest cities of Iran, namely, Ahvaz, Kermanshah, and Bushehr, in 2011. Materials and Methods In the present study, data relevant to the air-pollutant NO2 in 2011 was obtained from the Iranian Department of Environment and meteorological organizations of the studied cities. Raw data processing by Excel software included instruction set correction of averaging, coding, and filtering. Then the meteorological parameters were converted as input file to the Air Q model. Finally, by using epidemiologic formulas, relative risk (RR and attributed part to NO2 in the three studied cites were estimated. Results The results showed that in summer, winter, and the whole year, Kermanshah and Bushehr had on average the maximum and minimum NO2 concentration, respectively, in 2011. In addition, accumulative number of cases attributed to exposure with NO2 in the studied cities was maximum in Kermanshah (21 cases and minimum in Bushehr (one case. The results revealed that approximately, the maximum number of death cases attributed to NO2 were observed in Kermanshah due to heart problems (1.06%, acute infarction (1.8%, and obstructive pulmonary disease (1.9% with concentration > 20 μg/m3. Conclusions Every 10 μg/m3 increase in the concentration of the pollutant NO2 in the studied cities led to increase in the RR of myocardial infarction, cardiovascular diseases, and obstructive pulmonary disease by 0.4%, 0.2%, and 0.4%, respectively, in

  5. Study and modeling of the reduction of sulfur dioxide, nitrogen oxides and hydrogen chloride by dry injection technologies

    Energy Technology Data Exchange (ETDEWEB)

    Wang Wuyin

    1997-05-01

    The potential and mechanism to reduce acid gases, such as sulfur dioxide (SO{sub 2}), nitrogen oxides (NO{sub x}) and hydrogen chloride (HCl), by dry Ca-based sorbents have been studied to improve the efficiency of the process and sorbent utilization. Several natural limestones were tested for SO{sub 2} removal. Calcium conversion as high as 45 % was achieved in the first 0.3 s at 1000 deg C, 1000 ppm SO{sub 2} and Ca/S=1. A SO{sub 2} removal efficiency of 95 % was reached at Ca/S=2. Two models for estimating the sulfation of CaO at high temperature are presented. Short-residence-time sulfation is described by a pore size distribution model and long-residence-time sulfation by a particle expansion model. The pore size distribution model explains the effects of particle size, pore size distribution and partial pressure of SO{sub 2}, suggesting these three factors be the most important for CaO conversion. For particles larger than 1-2 {mu}m in furnace sorbent injection, pore diameters of 50-300 Aa are desirable. When large particles or long residence times are used, as in fluidized bed combustion, the particle expansion model shows the particle size and the sorbent type to be the main factors affecting the reaction. By using the selected limestone and additives the simultaneous SO{sub 2}/NO{sub x} removal was also measured. Several ammonium salts as well as urea were tested. Urea was found to give the highest NO{sub x} removal efficiency. To fully utilize the unreacted Ca-based sorbents, the spent sorbents from SO{sub 2} reduction processes were tested in a fixed-bed reactor to measure the capacity for HCl removal at 150-600 deg C. The results showed that all spent materials could react with HCl to some extent. After being calcined and slaked, they even showed the same reactivity as pure Ca(OH){sub 2}. A shrinking core model was derived for fixed-bed reactor. For the best sorbent tested, the multiple sorbent utilization reached about 80 %. 100 refs, 42 figs, 12 tabs

  6. Significant pulmonary response to a brief high-level, nose-only nitrogen dioxide exposure: an interspecies dosimetry perspective.

    Science.gov (United States)

    Elsayed, Nabil M; Gorbunov, Nikolai V; Mayorga, Maria A; Kagan, Valerian E; Januszkiewicz, Adolph J

    2002-10-01

    Brief, high-level nitrogen dioxide (NO(2)) exposures are major hazards during fires and heat-generating explosions. To characterize the lung response to a brief high-level NO(2) exposure, we exposed two groups (n = 5) of 325-375 g, male, Sprague-Dawley rats to either 200 +/- 5 ppm (376 +/- 9 mg/m(3)) NO(2) or room air for 15 min. The rats were nose-only exposed in a multiport exposure chamber fitted with pressure transducers to monitor their respiration during exposure. One hour after exposure, we euthanized the rats, collected blood samples, lavaged the lungs with warm saline, and then excised them. One lung lobe was cooled to -196 degrees C and used for low-temperature electron paramagentic resonance (EPR) analysis. The remainder was homogenized and used for biochemical analyses. Inspired minute ventilation (V(i)) during exposure decreased 59% (p < 0.05). Calculated total inspired dose was 0.880 mg NO(2). In lung lavage, both total and alveolar macrophage cell counts declined (approximately 75%, p < 0.05), but epithelial cell count increased 8.5-fold. Lung weight increased 40% (p < 0.05) after exposure. In the blood, potassium and methemoglobin increased 45 and 18% (p < 0.05), respectively; glucose, lactate, and total hemoglobin were not altered significantly. EPR analysis of lung tissue revealed hemoglobin oxidation and carbon-centered radical formation. Vitamins E and C and uric acid were depleted, and lipid peroxidation measured by three different methods (TBARS, conjugated dienes, and fluorescent peroxidation end products) was elevated, but total protein, DNA, and lipid contents were unchanged. These observations combined demonstrate that a brief (15 min) high-level (200 ppm) NO(2) exposure of rats was sufficient to cause significant damage. However, comparison of the exposure dose normalized to rat body weight with previously reported sheep and estimated human values revealed significant differences. This raises a question about interspecies dosimetry and

  7. Nitrogen dioxide - long-term guideline value for health protection; Stickstoffdioxid - (Langzeit-)Richtwert zum Schutz der menschlichen Gesundheit

    Energy Technology Data Exchange (ETDEWEB)

    Tvrdy, C.; Hauck, H.; Neuberger, M. [Vienna Univ. (Austria). Inst. fuer Umwelthygiene

    1999-10-01

    On behalf of the Ministry of Environment the Austrian Academy of Science published guideline values for nitrogen dioxide in 1988. The scientific database concentrated on short-term effects of NO{sub 2} at that time. After checking the current literature it was clear that new data especially for long-term effects of NO{sub 2} were available which should lead to a limitation of an annual average. Two Austrian studies on children from Linz (capital of Upper Austria) showed that high long-term concentrations of NO{sub 2} were negatively associated with the flow parameters of terminal airways in spirometry (MEF{sub 25} and MEF{sub 50}) on a significant level. In addition the children showed an improvement in growth-dependent increase of lung function parameters when long-term NO{sub 2}-concentrations in the ambient air could be decreased by more than 40 {mu}g/m{sup 3}. The most pronounced benefit could be seen when the ambient level of NO{sub 2} decreased during periods of accelerated growth. Based on these and other results summarized in this review, the Austrian Academy of Science recommended an annual average of 30 {mu}g/m{sup 3} for NO{sub 2} in the ambient air not to be exceeded for health protection. (orig.) [German] In Oesterreich werden von der Oesterreichischen Akademie der Wissenschaften (OeAW) im Auftrag des Bundesministeriums fuer Umwelt, Jugend und Familie fuer die konventionellen Luftschadstoffe wirkungsbezogene Immissionsgrenzkonzentrationen erarbeitet, die den jeweiligen Stand der (medizinischen) Wissenschaft repraesentieren. Ausgehend vom Basiswerk aus 1988 wurde 1998 eine neue Literaturstudie erstellt, die auch Publikationen der letzten Jahre umfasste. Anhand dieses neuen Datenmaterials zeigte sich, dass die Einfuehrung einer Langzeitimmissionsgrenzkonzentration aus umwelthygienischer Sicht notwendig war. In zwei Studien an Linzer Kindern konnte festgestellt werden, dass einerseits hohe NO{sub 2}-Konzentrationen signifikant negativ mit den

  8. Broadband cavity-enhanced absorption spectroscopy in the ultraviolet spectral region for measurements of nitrogen dioxide and formaldehyde

    Science.gov (United States)

    Washenfelder, R. A.; Attwood, A. R.; Flores, J. M.; Zarzana, K. J.; Rudich, Y.; Brown, S. S.

    2016-01-01

    Formaldehyde (CH2O) is the most abundant aldehyde in the atmosphere, and it strongly affects photochemistry through its photolysis. We describe simultaneous measurements of CH2O and nitrogen dioxide (NO2) using broadband cavity-enhanced absorption spectroscopy in the ultraviolet spectral region. The light source consists of a continuous-wave diode laser focused into a Xenon bulb to produce a plasma that emits high-intensity, broadband light. The plasma discharge is optically filtered and coupled into a 1 m optical cavity. The reflectivity of the cavity mirrors is 0.99930 ± 0.00003 (1- reflectivity = 700 ppm loss) at 338 nm, as determined from the known Rayleigh scattering of He and zero air. This mirror reflectivity corresponds to an effective path length of 1.43 km within the 1 m cell. We measure the cavity output over the 315-350 nm spectral region using a grating monochromator and charge-coupled device array detector. We use published reference spectra with spectral fitting software to simultaneously retrieve CH2O and NO2 concentrations. Independent measurements of NO2 standard additions by broadband cavity-enhanced absorption spectroscopy and cavity ring-down spectroscopy agree within 2 % (slope for linear fit = 1.02 ± 0.03 with r2 = 0.998). Standard additions of CH2O measured by broadband cavity-enhanced absorption spectroscopy and calculated based on flow dilution are also well correlated, with r2 = 0.9998. During constant mixed additions of NO2 and CH2O, the 30 s measurement precisions (1σ) of the current configuration were 140 and 210 pptv, respectively. The current 1 min detection limit for extinction measurements at 315-350 nm provides sufficient sensitivity for measurement of trace gases in laboratory experiments and ground-based field experiments. Additionally, the instrument provides highly accurate, spectroscopically based trace gas detection that may complement higher precision techniques based on non-absolute detection methods. In addition to

  9. Potential and limitations of the MAX-DOAS method to retrieve the vertical distribution of tropospheric nitrogen dioxide

    Directory of Open Access Journals (Sweden)

    T. Vlemmix

    2011-06-01

    Full Text Available Muliple Axis Differential Optical Absorption Spectroscopy (MAX-DOAS instruments can measure from the ground the absorption by nitrogen dioxide (NO2 of scattered sunlight seen in multiple viewing directions. This paper studies the potential of this technique to derive the vertical distribution of NO2 in the troposphere. Such profile information is essential in validation studies in which MAX-DOAS retrievals play a role.

    The retrieval algorithm used is based on a pre-calculated look-up table and assumes homogeneous mixing of aerosols and NO2 in layers extending from the surface to a variable height. Two retrieval models are compared: one including and one excluding an elevated NO2 layer at a fixed altitude in the free troposphere. An ensemble technique is applied to derive retrieved model uncertainties.

    Sensitivity studies demonstrate that MAX-DOAS based retrievals can make a distinction between an NO2 layer that extends from the surface to a certain height (having a constant mixing ratio, or a mixing ratio that decreases with altitude and an elevated NO2 layer. The height of the elevated NO2 layer can only be retrieved accurately when the aerosol extinction profile is known and the measurement noise is low. The uncertainty in this elevated NO2 layer height provides the main source of uncertainty in the retrieval of the free tropospheric contribution to the tropospheric NO2 column.

    A comparison was performed with independent data, based on observations done at the CINDI campaign, held in the Netherlands in 2009. Comparison with lidar partial tropospheric NO2 columns showed a correlation of 0.78, and an average difference of 0.1× 1015 molec cm−2. The diurnal evolution of the NO2 volume mixing ratio measured by in-situ monitors at the surface and averaged over five days with

  10. Changes of vascular endothelial growth factor and nitrogen monoxide in retina of rats with diabetes%糖尿病大鼠视网膜血管内皮生长因子和一氧化氮的变化

    Institute of Scientific and Technical Information of China (English)

    陈少强; 陈瑞华; 黄焱; 张更

    2004-01-01

    BACKGROUND:There is positive correlation between vascular endothelia growth factor(VEGF) and nitrogen monoxide in peripheral blood of diabetic patients.However,if there is any change of VEGF and nitrogen monoxide in retina tissues of diabetic patients is till uncertain. OBJECTIVE:To explore the changes of VEGF and nitrogen monoxide in retina tissues of diabetic rats and their effects on the origin and development of diabetic retinopathy(DR). DESIGN:Randomized case controlled study. INTERVENTIONS:The rats were randomly divided into normal control group,one month diabetic group,three months diabetic group and five months diabetic group,each with 20 rats.All the rats except the rats of normal group were abdominally injected strptozotin(STZ) once to induce diabetes models.Immunohistochemical method was applied to observe the expression of VEGF in retina tissues of each group.The activity of nitric oxide synthase(NOS) and the content changes of nitrogen monoxide of retina tissues were tested. RESULTS:Immunological positive reaction of VEGF is only found in inner nucleus layer of retina in normal rats,the content of NOS and NO was(36.17± 1.83) μ kat/g and(36.77± 2.33) μ mol/g respectively.In the third month,the expression of VEGF in the retina of diabetic rats increased significantly and the content of NOS and NO was(115.91± 31.5) μ kat/g and(68.34± 5.46) μ mol/g respectively.There was significant difference between this group and normal group(t=7.43,8.15,P< 0.01).In the fifth month,the expression of VEGF in retina was higher than that of rats in the third month diabetic group.The contents of NOS and NO were(72.35± 16.34) μ kat/g and(50.62± 3.01) μ mol/g.There was difference on this between the five months group and the third months group(t=4.76, 4.19,P< 0.05). CONCLUSION:The overexpression of VEGF,the activity of NOS as well as the content change of nitrogen monoxide in retina of rats with diabetes play important role on the origin and development of DR

  11. Allowed energetic pathways for the three-body recombination reaction of nitrogen monoxide with the hydroxyl radical and their potential atmospheric implications

    Directory of Open Access Journals (Sweden)

    Luca D´Ottone

    2010-12-01

    Full Text Available The OH initiated oxidation of nitric oxide (NO is an important atmospheric reaction being, during the day time, the main channel that leads to the formation of HONO a reservoir species for both OH and odd nitrogen. This work reports ab initio study of the Potential Energy Surface (PES of NO + OH using density functional theory calculations conducted at the B3LYP level of theory with a 6-311g (d,p basis set. We confirmed experimental observations pointing out that the main channel for this reaction is the formation the HONO. From the addition of OH to NO both cis and trans isomers of HONO were found to be the formed as stable intermediate, both having a negative enthalpy of formation relative to the reactants, the cis isomer being more stable than the trans one. The ab initio calculations were extended to include the hydrogen extraction mechanism with its respective transition state to investigate the potential existence of a reaction channel leading to the formation of NO2 + H, that was found not to be of significant interest.

  12. Carbon Monoxide Information Center

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  13. Carbon Monoxide Information Center

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  14. Carbon Monoxide Information Center

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    Science.gov (United States)

    ... and Criminal Penalties Federal Court Orders & Decisions Research & Statistics Research & Statistics Technical Reports Injury Statistics NEISS Injury Data ... On Safety Blogs: CO Safety More CO Blogs Research & Statistics JANUARY 07, 2016 Non-Fire Carbon Monoxide Deaths ...

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    Full Text Available ... Statistics JANUARY 07, 2016 Non-Fire Carbon Monoxide Deaths Associated with the Use of Consumer Products 2012 Annual Estimates OCTOBER 13, 2015 Incidents, Deaths, and In-Depth Investigations Associated with Non-Fire ...

  18. Carbon Monoxide Information Center

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    Full Text Available ... Unites States die every year from accidental non-fire related CO poisoning associated with consumer products, including ... CO Blogs Research & Statistics JANUARY 07, 2016 Non-Fire Carbon Monoxide Deaths Associated with the Use of ...

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  20. Carbon Monoxide Nonattainment Areas

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    U.S. Environmental Protection Agency — This data layer identifies areas in the U.S. where air pollution levels have not met the National Ambient Air Quality Standards (NAAQS) for Carbon Monoxide and have...

  1. Carbon Monoxide Information Center

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    Full Text Available ... Unites States die every year from accidental non-fire related CO poisoning associated with consumer products, including ... CO Blogs Research & Statistics JANUARY 07, 2016 Non-Fire Carbon Monoxide Deaths Associated with the Use of ...

  2. Nitrogen dioxide - current knowledge on the pollution situation and health effects; Stickstoffdioxid - Kenntnisstand zur Belastungssituation und zu gesundheitlichen Wirkungen

    Energy Technology Data Exchange (ETDEWEB)

    Muecke, H.G. [Umweltbundesamt, Berlin (Germany). Inst. fuer Wasser-, Boden- und Lufthygiene

    1999-07-01

    Since the 1990s atmospheric nitrogen dioxide (NO{sub 2}) pollution has mainly been determined by the volume of road traffic, especially in the urban centres of Germany. NO{sub 2} can be regarded as an important air pollutant inasmuch as it affects the health of a large part of the population. In places exposed to road traffic NO{sub 2} concentrations can easily reach and even exceed mean annual values of 100 {mu}g/m-3 and short-time peaks of 200 {mu}g/m-3. The main NO{sub 2} sources of indoor air pollution are open fireplaces (e.g. gas stoves, gas-fired heating systems and water heaters) and tobacco smoking. NO{sub 2} measurements in German kitchens yielded mean concentrations of up to 50 {mu}g/m-3 and peak concentrations of almost 200 {mu}g/m-3. Indoor NO{sub 2} concentrations in rooms without internal NO{sub 2} sources are determined by local atmospheric concentrations and have been found to lie between 20 and 30 {mu}g/m-3 on average. The WHO's revised NO{sub 2} guide values of 1998 are 40 {mu}g/m-3 in the annual average and 200 {mu}g/m-3 as hourly mean level. Being an oxidative and slightly water-soluble the tear gas NO{sub 2} mainly affects the periphery of the lungs. Its chief health effects are changes in pulmonary function and an increase in bronchial reactivity. Exposure studies on current pollution levels have shown that indoor sources contribute up to 5 {mu}g/m-3 on average and airing habits are an important influencing factor. [German] Seit den 90er Jahren bestimmt ueberwiegend der Kfz-Verkehr die Belastung der Aussenluft durch Stickstoffdioxid (NO{sub 2}), vor allem in den staedtischen Ballungsraeumen Deutschlands. NO{sub 2} kann als eine wichtige Luftschadstoffkomponente fuer die Gesundheit eines Grossteils der Bevoelkerung angesehen werden. An Kfz-exponierten Messstellen koennen die NO{sub 2}-Konzentrationen durchaus 100 {mu}g/m{sup 3} im Jahresmittel und 200 {mu}g/m{sup 3} als kurzzeitige Spitzenwerte erreichen oder ueberschreiten. Offene

  3. Carbon monoxide : A quantitative tracer for fossil fuel CO2?

    NARCIS (Netherlands)

    Gamnitzer, Ulrike; Karstens, Ute; Kromer, Bernd; Neubert, Rolf E. M.; Meijer, Harro A. J.; Schroeder, Hartwig; Levin, Ingeborg

    2006-01-01

    Carbon monoxide (CO), carbon dioxide (CO2), and radiocarbon ((CO2)-C-14) measurements have been made in Heidelberg from 2001 to 2004 in order to determine the regional fossil fuel CO2 component and to investigate the application of CO as a quantitative tracer for fossil fuel CO2 (CO2(foss)). The obs

  4. The Range of 1-3 keV Electrons in Solid Oxygen and Carbon Monoxide

    DEFF Research Database (Denmark)

    Oehlenschlæger, M.; Andersen, H.H.; Schou, Jørgen

    1985-01-01

    The range of 1-3 keV electrons in films of solid oxygen and carbon monoxide has been measured by a mirror substrate method. The technique used here is identical to the one previously used for range measurements in solid hydrogen and nitrogen. The range in oxygen is slightly shorter than...... that in nitrogen whereas the range in carbon monoxide is about 20% larger than that in the nitrogen....

  5. Synergistic effect of carbon monoxide with other biologically active injurious factors on the organism

    Energy Technology Data Exchange (ETDEWEB)

    Pankow, D.; Ponsold, W.

    1974-09-01

    The combined effects on biological organisms are reported for carbon monoxide and carbon dioxide, nitrogen oxides, sodium nitrite, hydrocyanic acid, carbon disulfide, sulfur dioxide, ammonia, hydrogen peroxide, ethanol, trichloroethylene, carbon tetrachloride, methane, benzene, iodine acetate, cholesterol, benzpyrene, hexobarbitol, zoxazolamine, nembutal, luminal, morphine, adrenalin, persantin, cytochrome c, aldrin, carbaryl, cyclodiene epoxide; and physical influences such as ambient temperature, atmospheric pressure, ionizing radiation, noise, and vibration. A literature review shows that with increasing CO/sub 2/ and decreasing oxygen concentration in the inhalation air, the toxicity of CO increased in experiments with mice and canaries. Oxides of nitrogen enhance the toxic effect of CO in an additive way and at times synergistically. At 500 m from a metallurgical plant in the USSR the maximum allowable immission concentrations for CO and SO/sub 2/ were exceeded. In children residing there a higher normal erythrocyte number, hemoglobin content, and catalase activity were found in the blood along with higher concentrations of coproporphyrin and 17-ketosteroids. All values returned to normal after an 8-week stay of these children away from the metallurgical plant.

  6. Formation of Amino Acids on the Sonolysis of Aqueous Solutions Containing Acetic Acid, Methane, or Carbon Dioxide, in the Presence of Nitrogen Gas.

    Science.gov (United States)

    Dharmarathne, Leena; Grieser, Franz

    2016-01-21

    The sonolysis of aqueous solutions containing acetic acid, methane, or carbon dioxide in the presence of nitrogen gas was found to produce a number of different amino acids at a rate of ∼1 to 100 nM/min, using ultrasound at an operating power of 70 W and 355 kHz. Gas-phase elementary reactions are suggested, and discussed, to account for the formation of the complex biomolecules from the low molar mass solutes used. On the basis of the results, a new hypothesis is presented to explain the formation of amino acids under primitive atmospheric conditions and how their formation may be linked to the eventual abiotic genesis of life on Earth.

  7. Use of pasive samplers to determine nitrogen dioxide en two municipalities in the metropolitan area of Costa Rica in 2004-2013

    Directory of Open Access Journals (Sweden)

    Jorge Herrera

    2014-12-01

    Full Text Available The performance of passive devices were evaluated for the determination of nitrogen dioxide in 25 sites of San Jose and Belen, for which first, the method parameters such as limit of detection and quantification were determined and the bias and precision results were satisfactory. At least five sites in San Jose and four in Belen have values greater than 40 ug / m3, which corresponds to that recommended by the World Health Organization criteria for this contaminant. The highest concentrations are presented for commercial sites with high traffic flow where exceedances can reach up to 45%. If these values are compared with those obtained for previous years a growth rate of 11 and 13% for commercial and industrial sites recorded respectively.

  8. Carbon Dioxide Absorbents

    Science.gov (United States)

    1950-05-17

    carbondioxide content of the solution was then determined. A gas mixture containing 2.6% carbon dioxide and 97.4% nitrogen was prepared in the...which carbon dioxide is removed by heat0 Since this step is usually carried out by "steam stripping ", that is, contacting the solution at its boiling...required to produce the steam required for stripping the carbon dioxide from the s olution. The method ueed in this investigation for determining the

  9. Long term effects of cerium dioxide nanoparticles on the nitrogen removal, micro-environment and community dynamics of a sequencing batch biofilm reactor.

    Science.gov (United States)

    Xu, Yi; Wang, Chao; Hou, Jun; Wang, Peifang; Miao, Lingzhan; You, Guoxiang; Lv, Bowen; Yang, Yangyang; Zhang, Fei

    2017-09-01

    The influences of cerium dioxide nanoparticles (CeO2 NPs) on nitrogen removal in biofilm were investigated. Prolonged exposure (75d) to 0.1mg/L CeO2 NPs caused no inhibitory effects on nitrogen removal, while continuous addition of 10mg/L CeO2 NPs decreased the treatment efficiency to 53%. With the progressive concentration of CeO2 NPs addition, the removal efficiency could nearly stabilize at 67% even with the continues spike of 10mg/L. The micro-profiles of dissolved oxygen, pH, and oxidation reduction potential suggested the developed protection mechanisms of microbes to progressive CeO2 NPs exposure led to the less influence of microenvironment, denitrification bacteria and enzyme activity than those with continuous ones. Furthermore, high throughput sequencing illustrated the drastic shifted communities with gradual CeO2 NPs spiking was responsible for the adaption and protective mechanisms. The present study demonstrated the acclimated microbial community was able to survive CeO2 NPs addition more readily than those non-acclimated. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Formation of nitrate and ammonium ions in titanium dioxide mediated photocatalytic degradation of organic compounds containing nitrogen atoms

    Energy Technology Data Exchange (ETDEWEB)

    Low, G.K.-C.; McEvoy, S.R.; Matthews, R.W. (CSIRO Division of Coal and Energy Technology, Menai (Australia))

    1991-03-01

    The photocatalytic oxidation of a related series of primary, secondary, and tertiary amines and other nitrogen- and sulfur-containing organic compounds over a UV-illuminated film of TiO{sub 2} has been studied. The compounds were as follows: n-pentylamine, piperidine, pyridine, phenylalanine, desipramine, thioridazine, penicillamine, isosorbide dinitrate, 4-nitrocatechol, 2,4-dinitrophenol, cyclophosphamide, 5-fluorouracil, atrazine, ethylenediaminetetracetic acid, and tetrabutylammonium phosphate. Both ammonium and nitrate ions were formed. The relative concentration of the two ions depended on the nature of the nitrogen in a compound, but was also influenced by the illumination time and concentration of the solute. It was found that for n-pentylamine, piperidine and pyridine, the rate of formation of ammonium ions was n-pentylamine {much gt} pyridine > piperidine. The order of rates of nitrate formation was pyridine = piperidine {much gt} pentylamine. For n-pentylamine the rate of formation of ammonium ions was {approximately}100 times that of nitrate.

  11. Post Hartree–Fock and DFT Studies on Pyrrole···Nitrogen and Pyrrole···Carbon Monoxide Molecules

    Directory of Open Access Journals (Sweden)

    P. Kolandaivel

    2002-07-01

    Full Text Available Abstract: The hydrogen bonded and van der Waals isomers of pyrrole···nitrogen and pyrrole···carbon monoxide have been studied using ab initio and density functional theory methods. Complex geometries and total energies of the isomers have been determined at HF, MP2, B3LYP and B3PW91 levels of theory employing 6-31G* basis set. For pyrrole···nitrogen complex, only two isomers have stable structure and the more stable one is found to be the hydrogen bonded isomer. Among the five isomers of pyrrole···carbon monoxide complex, the hydrogen bonded isomer is found to be the most stable form. The interaction energy for all these isomers have been calculated after eliminating the basis set superposition errors by using the full counterpoise correction method. Chemical hardness, chemical potential have been calculated and are used to study the stability of the molecules.

  12. Carbon dioxide concentration and nitrogen input affect the C and N storage pools in Amanita muscaria-Picea abies mycorrhizae.

    Science.gov (United States)

    Turnau, K; Berger, A; Loewe, A; Einig, W; Hampp, R; Chalot, M; Dizengremel, P; Kottke, I

    2001-02-01

    We studied the influence of elevated atmospheric CO2 concentration ([CO2]) on the vacuolar storage pool of nitrogen-containing compounds and on the glycogen pool in the hyphal sheath of Amanita muscaria (L. ex Fr.) Hooker-Picea abies L. Karst. mycorrhizae grown with two concentrations of ammonium in the substrate. Mycorrhizal seedlings were grown in petri dishes on agar containing 5.3 or 53 mg N l(-1) and exposed to 350 or 700 microl CO2 l(-1) for 5 or 7 weeks, respectively. Numbers and area of nitrogen-containing bodies in the vacuoles of the mycorrhizal fungus were determined by light microscopy linked to an image analysis system. The relative concentration of nitrogen in the vacuolar bodies was measured by electron energy loss spectroscopy (EELS). Glycogen stored in the cytosol was determined at the ultrastructural level by image analysis after staining the sections (PATAg test). Shoot dry weight, net photosynthesis and relative amounts of N in vacuolar bodies were greater at the higher N and CO2 concentrations. The numbers and areas of vacuolar N-containing bodies were significantly greater at the higher N concentration only at ambient [CO2]. In the same treatment the percentage of hyphae containing glycogen declined to nearly zero. We conclude that, in the high N/low [CO2] treatment, the mycorrhizal fungus had an insufficient carbohydrate supply, partly because of increased amino acid synthesis by the non-mycorrhizal rootlets. When [CO2] was increased, the equilibrium between storage of glycogen and N-containing compounds was reestablished.

  13. Photosynthesis acclimation, leaf nitrogen concentration, and growth of four tree species over 3 years in response to elevated carbon dioxide and nitrogen treatment in subtropical China

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Juxiu; Zhou, Guoyi; Duan, Honglang; Li, Yuelin; Zhang, Deqiang [Chinese Academy of Sciences, Guangzhou (China). South China Botanical Garden; Xu, Zhihong [Griffith Univ., Nathan, Brisbane (Australia). Centre for Forestry and Horticultural Research

    2011-10-15

    Up to date, most studies about the plant photosynthetic acclimation responses to elevated carbon dioxide (CO{sub 2}) concentration have been performed in temperate areas, which are often N limited under natural conditions and with low ambient N deposition. It is unclear whether photosynthetic downregulation is alleviated with increased N availability, for example, from increased N deposition due to fossil fuel combustion in the tropics and subtropics. Awareness of plant photosynthetic responses to elevated CO{sub 2} concentration will contribute to the better understanding and prediction of future forest productivity under global change. Four tree species, Schima superba Gardn. et Champ., Ormosia pinnata (Lour.) Merr, Castanopsis hystrix AC. DC., and Acmena acuminatissima (Blume) Merr. et Perry were exposed to a factorial combination of atmospheric CO{sub 2} concentration (ambient and elevated CO{sub 2} concentration at ca. 700 {mu}mol CO{sub 2} mol{sup -1}) and N deposition (ambient and ambient + 100 kg N ha{sup -1} year{sup -1}) in open-top chambers in southern China for 3 years since March 2005. Light-saturated net photosynthetic rate, leaf N concentration, and tree growth of all species were measured. The CO{sub 2} treatments did not affect light-saturated net photosynthetic rate of all species grown with the high N treatment. However, S. superba grown with the low N treatment (ambient) had 23% and 47% greater net photosynthesis in the ambient CO{sub 2} concentration than those in the elevated CO{sub 2} concentration for December 2006 and November 2007 (20 and 31 months after the treatments were applied), respectively, and A. acuminatissima grown with the low N treatment had 173%, 26%, and 121% greater net photosynthesis in trees grown in the ambient CO{sub 2} concentration than those in the elevated CO{sub 2} concentration for July 2006 (16 months after the treatments), December 2006 (20 months), and November 2007 (31 months), respectively, whereas

  14. Vapor pressures and calculated heats of vaporization of concentrated nitric acid solutions in the composition range 71 to 89 percent nitrogen dioxide, 1 to 10 percent water, and in the temperature range 10 to 60 degrees C

    Science.gov (United States)

    Mckeown, A B; Belles, Frank E

    1954-01-01

    Total vapor pressures were measured for 16 acid mixtures of the ternary system nitric acid, nitrogen dioxide, and water within the temperature range 10 degrees to 60 degrees Celsius, and with the composition range 71 to 89 weight percent nitric acid, 7 to 20 weight percent nitrogen dioxide, and 1 to 10 weight percent water. Heats of vaporization were calculated from the vapor pressure measurements for each sample for the temperatures 25, 40, and 60 degrees Celsius. The ullage of the apparatus used for the measurements was 0.46. Ternary diagrams showing isobars as a function of composition of the system were constructed from experimental and interpolated data for the temperatures 25, 40, 45, and 60 degrees C and are presented herein.

  15. Bioprocesses for removal of carbon dioxide and nitrogen oxide by microalgae for the utilization of gas generated during coal burning

    Energy Technology Data Exchange (ETDEWEB)

    Morais, Michele Greque de; Costa, Jorge Alberto Vieira [Fundacao Universidade Federal do Rio Grande, Rio Grande (Brazil)

    2008-07-01

    The aim of this work was to study the removal of CO{sub 2} and NO by microalgae and to evaluate the kinetic characteristics of the cultures. Spirulina sp. showed {mu}{sub max} and X{sub max} (0.11 d{sup -1}, 1.11 g L{sup -1} d{sup -1}) when treated with CO{sub 2} and NaNO{sub 3}. The maximum CO{sub 2} removal was 22.97% for S. obliquus treated with KNO{sub 3} and atmospheric CO{sub 2}. The S. obliquus showed maximum NO removal (21.30%) when treated with NO and CO{sub 2}. Coupling the cultivation of these microalgae with the removal of CO{sub 2} and NO has the potential not only to reduce the costs of culture media but also to offset carbon and nitrogen emissions. 19 refs., 3 figs., 2 tabs.

  16. Atmospheric carbon dioxide, irrigation, and fertilization effects on phenolic and nitrogen concentrations in loblolly pine (Pinus taeda) needles.

    Science.gov (United States)

    Booker, F L; Maier, C A

    2001-06-01

    Concentrations of total soluble phenolics, catechin, proanthocyanidins (PA), lignin and nitrogen (N) were measured in loblolly pine (Pinus taeda L.) needles exposed to either ambient CO(2) concentration ([CO(2)]), ambient plus 175 or ambient plus 350 micromol CO(2) mol(-1) in branch chambers for 2 years. The CO(2) treatments were superimposed on a 2 x 2 factorial combination of irrigation and fertilization treatments. In addition, we compared the effects of branch chambers and open-top chambers on needle chemistry. Proanthocyanidin and N concentrations were measured in needles from branch chambers and from trees in open-top chambers exposed concurrently for two years to either ambient [CO(2)] or ambient plus 200 micromol CO(2) mol(-1) in combination with a fertilization treatment. In the branch chambers, concentrations of total soluble phenolics in needles generally increased with needle age. Concentrations of total soluble phenolics, catechin and PA in needle extracts increased about 11% in response to the elevated [CO(2)] treatments. There were no significant treatment effects on foliar lignin concentrations. Nitrogen concentrations were about 10% lower in needles from the elevated [CO(2)] treatments than in needles from the ambient [CO(2)] treatments. Soluble phenolic and PA concentrations were higher in the control and irrigated soil treatments in about half of the comparisons; otherwise, differences were not statistically significant. Needle N concentrations increased 23% in response to fertilization. Treatment effects on PA and N concentrations were similar between branch and open-top chambers, although in this part of the study N concentrations were not significantly affected by the CO(2) treatments in either the branch or open-top chambers. We conclude that elevated [CO(2)] and low N availability affected foliar chemical composition, which could in turn affect plant-pathogen interactions, decomposition rates and mineral nutrient cycling.

  17. The statistical evaluation and comparison of ADMS-Urban model for the prediction of nitrogen dioxide with air quality monitoring network.

    Science.gov (United States)

    Dėdelė, Audrius; Miškinytė, Auksė

    2015-09-01

    In many countries, road traffic is one of the main sources of air pollution associated with adverse effects on human health and environment. Nitrogen dioxide (NO2) is considered to be a measure of traffic-related air pollution, with concentrations tending to be higher near highways, along busy roads, and in the city centers, and the exceedances are mainly observed at measurement stations located close to traffic. In order to assess the air quality in the city and the air pollution impact on public health, air quality models are used. However, firstly, before the model can be used for these purposes, it is important to evaluate the accuracy of the dispersion modelling as one of the most widely used method. The monitoring and dispersion modelling are two components of air quality monitoring system (AQMS), in which statistical comparison was made in this research. The evaluation of the Atmospheric Dispersion Modelling System (ADMS-Urban) was made by comparing monthly modelled NO2 concentrations with the data of continuous air quality monitoring stations in Kaunas city. The statistical measures of model performance were calculated for annual and monthly concentrations of NO2 for each monitoring station site. The spatial analysis was made using geographic information systems (GIS). The calculation of statistical parameters indicated a good ADMS-Urban model performance for the prediction of NO2. The results of this study showed that the agreement of modelled values and observations was better for traffic monitoring stations compared to the background and residential stations.

  18. Ambient air levels of volatile organic compounds (VOC) and nitrogen dioxide (NO{sub 2}) in a medium size city in Northern Spain

    Energy Technology Data Exchange (ETDEWEB)

    Parra, M.A. [Laboratorio Integrado de Calidad Ambiental (LICA), Departamento de Quimica y Edafologia, Facultad de Ciencias, Universidad de Navarra. Irunlarrea 1, 31008, Pamplona, Navarra (Spain)], E-mail: mparravi@alumni.unav.es; Elustondo, D.; Bermejo, R.; Santamaria, J.M. [Laboratorio Integrado de Calidad Ambiental (LICA), Departamento de Quimica y Edafologia, Facultad de Ciencias, Universidad de Navarra. Irunlarrea 1, 31008, Pamplona, Navarra (Spain)

    2009-01-15

    Ambient concentrations of volatile organic compounds (VOC) and nitrogen dioxide (NO{sub 2}) were measured by means of passive sampling at 40 sampling points in a medium-size city in Northern Spain, from June 2006 to June 2007. VOC and NO{sub 2} samplers were analysed by thermal desorption followed by gas chromatography/mass-selective detector and by visible spectrophotometry, respectively. Mean concentrations of benzene, toluene, ethylbenzene, xylenes, propylbenzene, trimethylbenzenes, and NO{sub 2} were 2.84, 13.26, 2.15, 6.01, 0.59, 1.32 and 23.17 {mu}g m{sup -3} respectively, and found to be highly correlated. Their spatial distribution showed high differences in small distances and pointed to traffic as the main emission source of these compounds. The lowest levels of VOC and NO{sub 2} occurred during summer, owing to the increase in solar radiation and to lower traffic densities. Mean concentrations of benzene and NO{sub 2} exceeded the European limits at some of the monitored points.

  19. An Evaluation of the FAST-J Photolysis algorithm for predicting nitrogen dioxide photolysis rates under clear and cloudy sky conditions

    Energy Technology Data Exchange (ETDEWEB)

    Barnard, James C.; Chapman, Elaine G.; Fast, Jerome D.; Schmelzer, John R.; Schlusser, James R.; Shetter, Richard E.

    2004-07-04

    The FAST-J model was developed to quickly calculate photolysis rates under both clear and cloudy sky conditions. In this paper, photolysis rates of nitrogen dioxide (NO2) were calculated using FAST-J and compared with measurements taken at two sites in the United States: Phoenix, Arizona, and Houston, Texas. The measurements were derived from either an actinic flux filter radiometer (Phoenix) or a spectroradiometer (Houston). A sun photometer, sited nearby these radiometers, provided irradiances measurements from which aerosol and cloud optical thicknesses were obtained. Aerosol single scattering albedo was not known, but was taken to be either 0.79 or 0.94, representative of either soot-like aerosols or sulfate-like aerosols, respectively. These optical properties served as input to the FAST-J model, which in turn was used to calculate photolysis rates. For both clear and cloudy sky cases, the modeled and measured photolysis rates agree within the uncertainties of the measurements for a single scattering albedo of 0.94. For a single scattering albedo of 0.79, the agreement is again within the uncertainty limits except for the cloudy sky case in Houston.

  20. Anatase/rutile bi-phasic titanium dioxide nanoparticles for photocatalytic applications enhanced by nitrogen doping and platinum nano-islands.

    Science.gov (United States)

    Bear, Joseph C; Gomez, Virginia; Kefallinos, Nikolaos S; McGettrick, James D; Barron, Andrew R; Dunnill, Charles W

    2015-12-15

    Titanium dioxide (TiO2) bi-phasic powders with individual particles containing an anatase and rutile hetero-junction have been prepared using a sequential layer sol-gel deposition technique to soluble substrates. Sequential thin films of rutile and subsequently anatase TiO2 were deposited onto sodium chloride substrates yielding extremely fragile composite layered discs that fractured into "Janus-like" like powders on substrate dissolution. Nitrogen doped and platinum sputtered analogues were also prepared, and analysed for photocatalytic potential using the photodegradation of Rhodamine B, a model organic pollutant under UV and visible light irradiation. The materials were characterised using X-ray diffraction, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy, Raman spectroscopy and scanning electron microscopy. This paper sheds light on the relationship between anatase and rutile materials when in direct contact and demonstrates a robust method for the synthesis of bi-phasic nanoparticles, ostensibly of any two materials, for photocatalytic reactions or otherwise.

  1. EOS7C Version 1.0: TOUGH2 Module for Carbon Dioxide or Nitrogen inNatural Gas (Methane) Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Oldenburg, Curtis M.; Moridis,George J.; Spycher, Nicholas; Pruess, Karsten

    2004-06-29

    EOS7C is a TOUGH2 module for multicomponent gas mixtures in the systems methane carbon dioxide (CH4-CO2) or methane-nitrogen (CH4-N2) with or without an aqueous phase and H2O vapor. EOS7C uses a cubic equation of state and an accurate solubility formulation along with a multiphase Darcy s Law to model flow and transport of gas and aqueous phase mixtures over a wide range of pressures and temperatures appropriate to subsurface geologic carbon sequestration sites and natural gas reservoirs. EOS7C models supercritical CO2 and subcritical CO2 as a non-condensible gas, hence EOS7C does not model the transition to liquid or solid CO2 conditions. The components modeled in EOS7C are water, brine, non-condensible gas, gas tracer, methane, and optional heat. The non-condensible gas (NCG) can be selected by the user to be CO2 or N2. The real gas properties module has options for Peng-Robinson, Redlich-Kwong, or Soave-Redlich-Kwong equations of state to calculate gas mixture density, enthalpy departure, and viscosity. Partitioning of the NCG and CH4 between the aqueous and gas phases is calculated using a very accurate chemical equilibrium approach. Transport of the gaseous and dissolved components is by advection and Fickian molecular diffusion. We present instructions for use and example problems to demonstrate the accuracy and practical application of EOS7C.

  2. MCSCF/CI ground state potential energy surface, dipole moment function, and gas phase vibrational frequencies for the nitrogen dioxide positive ion

    Energy Technology Data Exchange (ETDEWEB)

    Hopper, D.G.

    1980-05-01

    The ground state potential energy surface for the nitrogen dioxide positive ion, NO/sup +//sub 2/X /sup 1/..sigma../sup +//sub g/(..sigma../sup +/,A/sub 1/,A'), has been scanned with a correlated wave function to obtain directly, for the first time, the gas phase equilibrium geometry, force constants, vibrational frequencies, and dipole moment function. The wave function for this scan was constructed from a double-zeta plus polarization one-electron basis with a 12 configuration MCSCF determination of the orbital basis for a full valence /sup 1/..sigma../sup +//sub g/ configuration interaction expansion. The calculated equilibrium bond length is 1.12 A. The vibrational frequencies are computed to be ..nu../sub 1/=1514, ..nu../sub 2/=679, and ..nu../sub 3/=2614 cm/sup -1/ The present ab initio results differ significantly from crystalline spectroscopic studies and are, thus, the best values available for the gas phase vibrational frequencies. The dipole moment function is nonzero at the ..sigma../sup +/, A/sub 1/, and A' geometries included in the potential surface scan, and is obtained here to provide for the future a priori calculation of the infrared band intensities.

  3. Multiple axis DOAS measurements for the retrieval of nitrogen dioxide and ozone vertical profiles in the presidential estate of Castel Porziano, Rome

    Science.gov (United States)

    Palazzi, Elisa; Petritoli, Andrea; Ravegnani, Fabrizio; Kostadinov, Ivan; Bortoli, Daniele; Masieri, Samuele; Premuda, Margherita; Giovanelli, Giorgio

    2007-10-01

    In this paper we present a methodology for the retrieval of the vertical profile of atmospheric gas pollutants in the boundary layer from ground based remote sensing measurements. Nitrogen dioxide (NO II) and ozone (O 3) slant column amounts have been obtained with the Differential Optical Absorption Spectroscopy (DOAS) technique used in the multiple axis configuration (the so called MAX-DOAS). The measurements have been carried out in the Presidential Estate at Castel Porziano (Rome) in the period from September to November 2006 in the frame of a programme started in 1994 for studying and monitoring the Estate's environment. The retrieval of information on the vertical profile of trace gases from their slant column amounts requires: (1) the simulation of the radiative transfer in the atmosphere for Air Mass Factor (AMF) calculation; (2) the application of inversion schemes. In this paper the vertical profiles of NO II and O 3 obtained from multiple axis DOAS measurements and their daily evolution are presented and discussed. The day under study is the 29th of October, 2006.

  4. Nitrogen Dioxide-Sensing Properties at Room Temperature of Metal Oxide-Modified Graphene Composite via One-Step Hydrothermal Method

    Science.gov (United States)

    Zhang, Dongzhi; Liu, Jingjing; Xia, Bokai

    2016-08-01

    A metal oxide/graphene composite film-based sensor toward room-temperature detection of ppm-level nitrogen dioxide (NO2) gas has been demonstrated. The sensor prototype was constructed on a PCB substrate with microelectrodes, and a tin oxide-reduced graphene oxide (SnO2-rGO) composite as sensing film was prepared by one-step hydrothermal synthesis of tin tetrachloride pentahydrate solution in the presence of graphene oxide (GO). The SnO2-rGO hybrid composite was examined by scanning electron microscope and x-ray diffraction (XRD). The gas sensing properties of the SnO2-rGO composite were investigated at room temperature by exposing it to a wide concentration ranging from 1 ppm to 2000 ppm toward NO2 gas. The experiment results showed that the sensor exhibited a high response, superior selectivity, good repeatability, rapid response/recovery characteristics and low detection limit of 1 ppm, which exceeded that of a pure rGO sensor. The gas sensing mechanisms of the proposed sensor toward NO2 were possibly attributed to the nano-hybrid structures and n- p heterojunctions created at the interface of the SnO2 nanocrystals and rGO nanosheets.

  5. Investigating the nitrogen dioxide concentrations in the boundary layer by using multi-axis spectroscopic measurements and comparison with satellite observations.

    Science.gov (United States)

    Khokhar, Muhammad Fahim; Nisar, Munazza; Noreen, Asma; Khan, Waseem Razzaq; Hakeem, Khalid Rehman

    2017-01-01

    This study emphasizes on near surface observation of chemically active trace gases such as nitrogen dioxide (NO2) over Islamabad on a regular basis. Absorption spectroscopy using backscattered extraterrestrial light source technique was used to retrieve NO2 differential slant column densities (dSCDs). Mini multi-axis-differential optical absorption spectroscopy (MAX-DOAS) instrument was used to perform ground-based measurements at Institute of Environmental Sciences and Engineering (IESE), National University of Sciences and Technology (NUST) Islamabad, Pakistan. Tropospheric vertical column densities (VCDs) of NO2 were derived from measured dSCDs by using geometric air mass factor approach. A case study was conducted to identify the impact of different materials (glass, tinted glass, and acrylic sheet of various thicknesses used to cover the instrument) on the retrieval of dSCDs. Acrylic sheet of thickness 5 mm was found most viable option for casing material as it exhibited negligible impact in the visible wavelength range. Tropospheric NO2 VCD derived from ground-based mini MAX-DOAS measurements exceeded two times the Pak-NEQS levels and showed a reasonable comparison (r (2) = 0.65, r = 0.81) with satellite observations (root mean square bias of 39 %) over Islamabad, Pakistan.

  6. Application of visible-light photocatalysis with nitrogen-doped or unmodified titanium dioxide for control of indoor-level volatile organic compounds.

    Science.gov (United States)

    Jo, Wan-Kuen; Kim, Jong-Tae

    2009-05-15

    The present study evaluated visible-light photocatalysis, applying an annular reactor coated with unmodified or nitrogen (N)-doped titanium dioxide (TiO(2)), to cleanse gaseous volatile organic compounds (VOCs) at indoor levels. The surface chemistry investigation of N-doped TiO(2) suggested that there was no significant residual of sulfate ions or urea species on the surface of the N-doped TiO(2). Under visible-light irradiation, the photocatalytic technique using N-doped TiO(2) was much superior to that for unmodified TiO(2) for the degradation of VOCs. Moreover, the degradation efficiency by a reactor coated with N-doped TiO(2) was well above 90% for four target compounds (ethyl benzene, o,m,p-xylenes), suggesting that this photocatalytic system can be effectively employed to cleanse these pollutants at indoor air quality (IAQ) levels. The degradation efficiency of all target compounds increased as the stream flow rate (SFR) decreased. For most target compounds, a reactor with a lower hydraulic diameter (HD) exhibited elevated degradation efficiency. The result on humidity effect suggested that the N-doped photocatalyst could be employed effectively to remove four target compounds (ethyl benzene, o,m,p-xylenes) under conditions of less humidified environments, including a typical indoor comfort range (50-60%). Consequently, it is suggested that with appropriate photocatalytic conditions, a visible-light-assisted N-doped photocatalytic system is clearly an important tool for improving IAQ.

  7. Investigation of the gas-solid Joule-Thomson effect for argon-, nitrogen-, and carbon dioxide-carbon powder aerosol systems

    Energy Technology Data Exchange (ETDEWEB)

    Rybolt, T.R.; Pierotti, R.A.

    1984-05-24

    An apparatus was constructed to disperse a fine powder in a flowing gas and measure the thermal changes associated with a pressure drop across a glass orifice. The gas-solid Joule-Thomson effect was examined for 12 different gas-solids systems at a temperature of 302 K, a downstream pressure of 120 kPa, pressure drops across the orifice from 5 to 45 kPa, flow rates from 2 to 14 mmol/s, and aerosol concentrations from 0 to 16 g of powder/mol of gas. The gaseous component included either argon, nitrogen, or carbon dioxide and the particulate component included either Mexican Graphite (26 m/sup 2//g), Nuchar S-C (903 m/sup 2//g), Nuchar S-A (1661 m/sup 2//g), or Super Sorb (3169 m/sup 2//g) carbon powder. A significant enhancement of the Joule-Thomson cooling effect was found for gas-porous carbon systems relative to a pure gas. The dependence of the magnitude of this effect on the gas-gas and gas-solid interactions was predicted from a virial equation of state based on statistical thermodynamic considerations. Gas-solid virial coefficients and their temperature derivatives were used in conjunction with the theoretical model as modified by heat-transport effects to assess the reliability of theory in predicting the experimentally determined gas-solid Joule-Thomson coefficients.

  8. Elucidation of rice rhizosphere metagenome in relation to methane and nitrogen metabolism under elevated carbon dioxide and temperature using whole genome metagenomic approach.

    Science.gov (United States)

    Bhattacharyya, P; Roy, K S; Das, M; Ray, S; Balachandar, D; Karthikeyan, S; Nayak, A K; Mohapatra, T

    2016-01-15

    Carbon (C) and nitrogen (N) mineralization is one of the key processes of biogeochemical cycling in terrestrial ecosystem in general and rice ecology in particular. Rice rhizosphere is a rich niche of microbial diversity influenced by change in atmospheric temperature and concentration of carbon dioxide (CO2). Structural changes in microbial communities in rhizosphere influence the nutrient cycling. In the present study, the bacterial diversity and population dynamics were studied under ambient CO2 (a-CO2) and elevated CO2+temperature (e-CO2T) in lowland rice rhizosphere using whole genome metagenomic approach. The whole genome metagenomic sequence data of lowland rice exhibited the dominance of bacterial communities including Proteobacteria, Firmicutes, Acidobacteria, Actinobacteria and Planctomycetes. Interestingly, four genera related to methane production namely, Methanobacterium, Methanosphaera, Methanothermus and Methanothermococcus were absent in a-CO2 but noticed under e-CO2T. The acetoclastic pathway was found as the predominant pathway for methanogenesis, whereas, the serine pathway was found as the principal metabolic pathway for CH4 oxidation in lowland rice. The abundances of reads of enzymes in the acetoclastic methanogenesis pathway and serine pathways of methanotrophy were much higher in e-CO2T (328 and 182, respectively) as compared with a-CO2 (118 and 98, respectively). Rice rhizosphere showed higher structural diversities and functional activities in relation to N metabolism involving nitrogen fixation, assimilatory and dissimilatory nitrate reduction and denitrification under e-CO2T than that of a-CO2. Among the three pathways of N metabolism, dissimilarity pathways were predominant in lowland rice rhizosphere and more so under e-CO2T. Consequently, under e-CO2T, CH4 emission, microbial biomass nitrogen (MBN) and dehydrogenase activities were 45%, 20% and 35% higher than a-CO2, respectively. Holistically, a high bacterial diversity and

  9. Synthesis of High-Surface-Area Nitrogen-Doped Porous Carbon Microflowers and Their Efficient Carbon Dioxide Capture Performance.

    Science.gov (United States)

    Li, Yao; Cao, Minhua

    2015-07-01

    Sustainable carbon materials have received particular attention in CO2 capture and storage owing to their abundant pore structures and controllable pore parameters. Here, we report high-surface-area hierarchically porous N-doped carbon microflowers, which were assembled from porous nanosheets by a three-step route: soft-template-assisted self-assembly, thermal decomposition, and KOH activation. The hydrazine hydrate used in our experiment serves as not only a nitrogen source, but also a structure-directing agent. The activation process was carried out under low (KOH/carbon=2), mild (KOH/carbon=4) and severe (KOH/carbon=6) activation conditions. The mild activated N-doped carbon microflowers (A-NCF-4) have a hierarchically porous structure, high specific surface area (2309 m(2)  g(-1)), desirable micropore size below 1 nm, and importantly large micropore volume (0.95 cm(3)  g(-1)). The remarkably high CO2 adsorption capacities of 6.52 and 19.32 mmol g(-1) were achieved with this sample at 0 °C (273 K) and two pressures, 1 bar and 20 bar, respectively. Furthermore, this sample also exhibits excellent stability during cyclic operations and good separation selectivity for CO2 over N2.

  10. Snowpack-atmosphere gas exchanges of carbon dioxide, ozone, and nitrogen oxides at a hardwood forest site in northern Michigan

    Directory of Open Access Journals (Sweden)

    Brian Seok

    2015-03-01

    Full Text Available Abstract Snowpack-atmosphere gas exchanges of CO2, O3, and NOx (NO + NO2 were investigated at the University of Michigan Biological Station (UMBS, a mid-latitude, low elevation hardwood forest site, during the 2007–2008 winter season. An automated trace gas sampling system was used to determine trace gas concentrations in the snowpack at multiple depths continuously throughout the snow-covered period from two adjacent plots. One natural plot and one with the soil covered by a Tedlar sheet were setup for investigating whether the primary source of measured trace gases was biogenic (i.e., from the soil or non-biogenic (i.e., from the snowpack. The results were compared with the “White on Green” study conducted at the Niwot Ridge (NWT Long Term Ecological Research site in Colorado. The average winter CO2 flux ± s.e. from the soil at UMBS was 0.54 ± 0.037 µmol m-2 s-1 using the gradient diffusion method and 0.71 ± 0.012 µmol m-2 s-1 using the eddy covariance method, and in a similar range as found for NWT. Observed snowpack-O3 exchange was also similar to NWT. However, nitrogen oxides (NOx fluxes from snow at UMBS were 10 times smaller than those at NWT, and fluxes were bi-directional with the direction of the flux dependent on NOx concentrations in ambient air. The compensation point for the change in the direction of NOx flux was estimated to be 0.92 nmol mol-1. NOx in snow also showed diurnal dependency on incident radiation. These NOx dynamics in the snow at UMBS were notably different compared to NWT, and primarily determined by snow-atmosphere interactions rather than by soil NOx emissions.

  11. Subalpine grassland carbon dioxide fluxes indicate substantial carbon losses under increased nitrogen deposition, but not at elevated ozone concentration

    Science.gov (United States)

    Volk, Matthias; Obrist, Daniel; Novak, Kris; Giger, Robin; Bassin, Seraina; Fuhrer, Jürg

    2010-05-01

    Ozone (O3) and nitrogen (N) deposition affect plant carbon (C) dynamics and may thus change ecosystem C-sink/-source properties. We studied effects of increased background O3 concentrations (up to ambient x 2) and increased N deposition (up to +50 kg ha-1 a-1) on mature, subalpine grassland during the third treatment year. During ten days and 13 nights, covering the vegetation period of 2006, we measured ecosystem-level CO2 exchange using a steady state cuvette. Light dependency of gross primary production (GPP) and temperature dependency of ecosystem respiration rates (Reco) were established. Soil temperature, soil water content, and solar radiation were monitored. Using Reco and GPP values, we calculated seasonal net ecosystem production (NEP), based on hourly averages of global radiation and soil temperature. Differences in NEP were compared to differences in soil organic C after five years of treatment. Under high O3 and with unchanged aboveground biomass, both mean Reco and GPP decreased throughout the season. Thus, NEP indicated an unaltered growing season CO2-C balance. Under high N treatment, with a +31% increase in aboveground productivity, mean Reco, but not GPP increased. Consequently, seasonal NEP yielded a 53.9 g C m-2 (± 22.05) C loss compared to control. Independent of treatment, we observed a negative NEP of 146.4 g C m-2 (±15.3). This C loss was likely due to a transient management effect, equivalent to a shift from pasture to hay meadow and a drought effect, specific to the 2006 summer climate. We argue that this resulted from strongly intensified soil microbial respiration, following mitigation of nutrient limitation. There was no interaction between O3 and N treatments. Thus, during the 2006 growing season, the subalpine grassland lost >2% of total topsoil organic C as respired CO2, with increased N deposition responsible for one-third of that loss.

  12. Cyclic process for producing methane from carbon monoxide with heat removal

    Science.gov (United States)

    Frost, Albert C.; Yang, Chang-lee

    1982-01-01

    Carbon monoxide-containing gas streams are converted to methane by a cyclic, essentially two-step process in which said carbon monoxide is disproportionated to form carbon dioxide and active surface carbon deposited on the surface of a catalyst, and said carbon is reacted with steam to form product methane and by-product carbon dioxide. The exothermic heat of reaction generated in each step is effectively removed during each complete cycle so as to avoid a build up of heat from cycle-to-cycle, with particularly advantageous techniques being employed for fixed bed, tubular and fluidized bed reactor operations.

  13. Effect of fresh green waste and green waste compost on mineral nitrogen, nitrous oxide and carbon dioxide from a Vertisol.

    Science.gov (United States)

    Vaughan, Sarah M; Dalal, Ram C; Harper, Stephen M; Menzies, Neal W

    2011-08-01

    Incorporation of organic waste amendments to a horticultural soil, prior to expected risk periods, could immobilise mineral N, ultimately reducing nitrogen (N) losses as nitrous oxide (N(2)O) and leaching. Two organic waste amendments were selected, a fresh green waste (FGW) and green waste compost (GWC) as they had suitable biochemical attributes to initiate N immobilisation into the microbial biomass and organic N forms. These characteristics include a high C:N ratio (FGW 44:1, GWC 35:1), low total N (14%). Both products were applied at 3t C/ha to a high N (plus N fertiliser) or low N (no fertiliser addition) Vertisol soil in PVC columns. Cumulative N(2)O production over the 28 day incubation from the control soil was 1.5mg/N(2)O/m(2), and 11mg/N(2)O/m(2) from the control+N. The N(2)O emission decreased with GWC addition (Psoil, reducing cumulative N(2)O emissions by 38% by the conclusion of the incubation. Analysis of mineral N concentrations at 7, 14 and 28 days identified that both FGW and GWC induced microbial immobilisation of N in the first 7 days of incubation regardless of whether the soil environment was initially high or low in N; with the FGW immobilising up to 30% of available N. It is likely that the reduced mineral N due to N immobilisation led to a reduced substrate for N(2)O production during the first week of the trial, when soil N(2)O emissions peaked. An additional finding was that FGW+N did not decrease cumulative N(2)O emissions compared to the control+N, potentially due to the fact that it stimulated microbial respiration resulting in anaerobic micro sites in the soil and ultimately N(2)O production via denitrification. Therefore, both materials could be used as post harvest amendments in horticulture to minimise N loss through nitrate-N leaching in the risk periods between crop rotations. The mature GWC has potential to reduce N(2)O, an important greenhouse gas.

  14. Effect of irrigation, nitrogen application, and a nitrification inhibitor on nitrous oxide, carbon dioxide and methane emissions from an olive (Olea europaea L.) orchard.

    Science.gov (United States)

    Maris, S C; Teira-Esmatges, M R; Arbonés, A; Rufat, J

    2015-12-15

    Drip irrigation combined with nitrogen (N) fertigation is applied in order to save water and improve nutrient efficiency. Nitrification inhibitors reduce greenhouse gas emissions. A field study was conducted to compare the emissions of nitrous oxide (N2O), carbon dioxide (CO2) and methane (CH4) associated with the application of N fertiliser through fertigation (0 and 50kgNha(-1)), and 50kgNha(-1)+nitrification inhibitor in a high tree density Arbequina olive orchard. Spanish Arbequina is the most suited variety for super intensive olive groves. This system allows reducing production costs and increases crop yield. Moreover its oil has excellent sensorial features. Subsurface drip irrigation markedly reduced N2O and N2O+N2 emissions compared with surface drip irrigation. Fertiliser application significantly increased N2O+N2, but not N2O emissions. Denitrification was the main source of N2O. The N2O losses (calculated as emission factor) ranging from -0.03 to 0.14% of the N applied, were lower than the IPCC (2007) values. The N2O+N2 losses were the largest, equivalent to 1.80% of the N applied, from the 50kgNha(-1)+drip irrigation treatment which resulted in water filled pore space >60% most of the time (high moisture). Nitrogen fertilisation significantly reduced CO2 emissions in 2011, but only for the subsurface drip irrigation strategies in 2012. The olive orchard acted as a net CH4 sink for all the treatments. Applying a nitrification inhibitor (DMPP), the cumulative N2O and N2O+N2 emissions were significantly reduced with respect to the control. The DMPP also inhibited CO2 emissions and significantly increased CH4 oxidation. Considering global warming potential, greenhouse gas intensity, cumulative N2O emissions and oil production, it can be concluded that applying DMPP with 50kgNha(-1)+drip irrigation treatment was the best option combining productivity with keeping greenhouse gas emissions under control.

  15. Temporal characteristics of atmospheric ammonia and nitrogen dioxide over China based on emission data, satellite observations and atmospheric transport modeling since 1980

    Science.gov (United States)

    Liu, Lei; Zhang, Xiuying; Xu, Wen; Liu, Xuejun; Li, Yi; Lu, Xuehe; Zhang, Yuehan; Zhang, Wuting

    2017-08-01

    China is experiencing intense air pollution caused in large part by anthropogenic emissions of reactive nitrogen (Nr). Atmospheric ammonia (NH3) and nitrogen dioxide (NO2) are the most important precursors for Nr compounds (including N2O5, HNO3, HONO and particulate NO3- and NH4+) in the atmosphere. Understanding the changes in NH3 and NO2 has important implications for the regulation of anthropogenic Nr emissions and is a requirement for assessing the consequence of environmental impacts. We conducted the temporal trend analysis of atmospheric NH3 and NO2 on a national scale since 1980 based on emission data (during 1980-2010), satellite observation (for NH3 since 2008 and for NO2 since 2005) and atmospheric chemistry transport modeling (during 2008-2015).Based on the emission data, during 1980-2010, significant continuous increasing trends in both NH3 and NOx were observed in REAS (Regional Emission inventory in Asia, for NH3 0.17 and for NOx 0.16 kg N ha-1 yr-2) and EDGAR (Emissions Database for Global Atmospheric Research, for NH3 0.24 and for NOx 0.17 kg N ha-1 yr-2) over China. Based on the satellite data and atmospheric chemistry transport model (CTM) MOZART-4 (Model for Ozone and Related chemical Tracers, version 4), the NO2 columns over China increased significantly from 2005 to 2011 and then decreased significantly from 2011 to 2015; the satellite-retrieved NH3 columns from 2008 to 2014 increased at a rate of 2.37 % yr-1. The decrease in NO2 columns since 2011 may result from more stringent strategies taken to control NOx emissions during the 12th Five Year Plan, while no control policy has focused on NH3 emissions. Our findings provided an overall insight into the temporal trends of both NO2 and NH3 since 1980 based on emission data, satellite observations and atmospheric transport modeling. These findings can provide a scientific background for policy makers that are attempting to control atmospheric pollution in China. Moreover, the multiple datasets

  16. Spatio-Temporal Variation and Futuristic Emission Scenario of Ambient Nitrogen Dioxide over an Urban Area of Eastern India Using GIS and Coupled AERMOD–WRF Model

    Science.gov (United States)

    Dey, Sharadia; Gupta, Srimanta; Sibanda, Precious; Chakraborty, Arun

    2017-01-01

    The present study focuses on the spatio-temporal variation of nitrogen dioxide (NO2) during June 2013 to May 2015 and its futuristic emission scenario over an urban area (Durgapur) of eastern India. The concentration of ambient NO2 shows seasonal as well as site specific characteristics. The site with high vehicular density (Muchipara) shows highest NO2 concentration followed by industrial site (DVC- DTPS Colony) and the residential site (B Zone), respectively. The seasonal variation of ambient NO2 over the study area is portrayed by means of Geographical Information System based Digital Elevation Model. Out of the total urban area under consideration (114.982 km2), the concentration of NO2 exceeded the National Ambient Air Quality Standard (NAAQS) permissible limit over an area of 5.000 km2, 0.786 km2 and 0.653 km2 in post monsoon, winter and pre monsoon, respectively. Wind rose diagrams, correlation and regression analyses show that meteorology plays a crucial role in dilution and dispersion of NO2 near the earth’s surface. Principal component analysis identifies vehicular source as the major source of NO2 in all the seasons over the urban region. Coupled AMS/EPA Regulatory Model (AERMOD)–Weather Research and Forecasting (WRF) model is used for predicting the concentration of NO2. Comparison of the observed and simulated data shows that the model overestimates the concentration of NO2 in all the seasons (except winter). The results show that coupled AERMOD–WRF model can overcome the unavailability of hourly surface as well as upper air meteorological data required for predicting the pollutant concentration, but improvement of emission inventory along with better understanding of the sinks and sources of ambient NO2 is essential for capturing the more realistic scenario. PMID:28141866

  17. Spatio-Temporal Variation and Futuristic Emission Scenario of Ambient Nitrogen Dioxide over an Urban Area of Eastern India Using GIS and Coupled AERMOD-WRF Model.

    Science.gov (United States)

    Dey, Sharadia; Gupta, Srimanta; Sibanda, Precious; Chakraborty, Arun

    2017-01-01

    The present study focuses on the spatio-temporal variation of nitrogen dioxide (NO2) during June 2013 to May 2015 and its futuristic emission scenario over an urban area (Durgapur) of eastern India. The concentration of ambient NO2 shows seasonal as well as site specific characteristics. The site with high vehicular density (Muchipara) shows highest NO2 concentration followed by industrial site (DVC- DTPS Colony) and the residential site (B Zone), respectively. The seasonal variation of ambient NO2 over the study area is portrayed by means of Geographical Information System based Digital Elevation Model. Out of the total urban area under consideration (114.982 km2), the concentration of NO2 exceeded the National Ambient Air Quality Standard (NAAQS) permissible limit over an area of 5.000 km2, 0.786 km2 and 0.653 km2 in post monsoon, winter and pre monsoon, respectively. Wind rose diagrams, correlation and regression analyses show that meteorology plays a crucial role in dilution and dispersion of NO2 near the earth's surface. Principal component analysis identifies vehicular source as the major source of NO2 in all the seasons over the urban region. Coupled AMS/EPA Regulatory Model (AERMOD)-Weather Research and Forecasting (WRF) model is used for predicting the concentration of NO2. Comparison of the observed and simulated data shows that the model overestimates the concentration of NO2 in all the seasons (except winter). The results show that coupled AERMOD-WRF model can overcome the unavailability of hourly surface as well as upper air meteorological data required for predicting the pollutant concentration, but improvement of emission inventory along with better understanding of the sinks and sources of ambient NO2 is essential for capturing the more realistic scenario.

  18. Nitrogen dioxide levels estimated from land use regression models several years apart and association with mortality in a large cohort study

    Directory of Open Access Journals (Sweden)

    Cesaroni Giulia

    2012-07-01

    Full Text Available Abstract Background Land Use Regression models (LUR are useful to estimate the spatial variability of air pollution in urban areas. Few studies have evaluated the stability of spatial contrasts in outdoor nitrogen dioxide (NO2 concentration over several years. We aimed to compare measured and estimated NO2 levels 12 years apart, the stability of the exposure estimates for members of a large cohort study, and the association of the exposure estimates with natural mortality within the cohort. Methods We measured NO2 at 67 locations in Rome in 1995/96 and 78 sites in 2007, over three one-week-long periods. To develop LUR models, several land-use and traffic variables were used. NO2 concentration at each residential address was estimated for a cohort of 684,000 adults. We used Cox regression to analyze the association between the two estimated exposures and mortality. Results The mean NO2 measured concentrations were 45.4 μg/m3 (SD 6.9 in 1995/96 and 44.6 μg/m3 (SD 11.0 in 2007, respectively. The correlation of the two measurements was 0.79. The LUR models resulted in adjusted R2 of 0.737 and 0.704, respectively. The correlation of the predicted exposure values for cohort members was 0.96. The association of each 10 μg/m3 increase in NO2 with mortality was 6 % for 1995/96 and 4 % for 2007 LUR models. The increased risk per an inter-quartile range change was identical (4 %, 95 % CI:3–6 % for both estimates of NO2. Conclusions Measured and predicted NO2 values from LUR models, from samples collected 12 years apart, had good agreement, and the exposure estimates were similarly associated with mortality in a large cohort study.

  19. Short-Term Effects of Nitrogen Dioxide on Mortality and Susceptibility Factors in 10 Italian Cities: The EpiAir Study.

    Science.gov (United States)

    Chiusolo, Monica; Cadum, Ennio; Stafoggia, Massimo; Galassi, Claudia; Berti, Giovanna; Faustini, Annunziata; Bisanti, Luigi; Vigotti, Maria Angela; Dessì, Maria Patrizia; Cernigliaro, Achille; Mallone, Sandra; Pacelli, Barbara; Minerba, Sante; Simonato, Lorenzo; Forastiere, Francesco

    2011-09-01

    Several studies have shown an association between nitrogen dioxide (NO2) and mortality. In Italy, the EpiAir multicentric study, "Air Pollution and Health: Epidemiological Surveillance and Primary Prevention," investigated short-term health effects of air pollution, including NO2. To study the individual susceptibility, we evaluated the association between NO2 and cause-specific mortality, investigating individual sociodemographic features and chronic/acute medical conditions as potential effect modifiers. We considered 276,205 natural deaths of persons > 35 years of age, resident in 10 Italian cities, and deceased between 2001 and 2005. We chose a time-stratified case-crossover analysis to evaluate the short-term effects of NO2 on natural, cardiac, cerebrovascular, and respiratory mortality. For each subject, we collected information on sociodemographic features and hospital admissions in the previous 2 years. Fixed monitors provided daily concentrations of NO2, particulate matter ≤ 10 μm in aerodynamic diameter (PM10) and ozone (O3). We found statistically significant associations with a 10-μg/m3 increase of NO2 for natural mortality [2.09% for lag 0-5; 95% confidence interval (CI), 0.96-3.24], for cardiac mortality (2.63% for lag 0-5; 95% CI, 1.53-3.75), and for respiratory mortality (3.48% for lag 1-5; 95% CI, 0.75-6.29). These associations were independent from those of PM10 and O3. Stronger associations were estimated for subjects with at least one hospital admission in the 2 previous years and for subjects with three or more specific chronic conditions. Some cardiovascular conditions (i.e., ischemic heart disease, pulmonary circulation impairment, heart conduction disorders, heart failure) and diabetes appeared to confer a strong susceptibility to air pollution. Our results suggest significant and likely independent effects of NO2 on natural, cardiac, and respiratory mortality, particularly among subjects with specific cardiovascular preexisting chronic

  20. The effect of free air carbon dioxide enrichment and nitrogen fertilisation on the chemical composition and nutritional value of wheat and barley grain.

    Science.gov (United States)

    Wroblewitz, Stefanie; Hüther, Liane; Manderscheid, Remy; Weigel, Hans-Joachim; Wätzig, Hermann; Dänicke, Sven

    2013-08-01

    A rising atmospheric CO2 concentration might influence the nutrient composition of feedstuffs and consequently the nutritional value for livestock. The present study investigates the effects of atmospheric CO2 enrichment on the chemical composition and nutritional value of winter wheat cv. "Batis" and winter barley cv. "Theresa". Both cereals were grown at two different atmospheric CO2 concentrations (ambient CO2 [AMBI]: 380 ppm and enriched CO2 [free air carbon dioxide enrichment, FACE]: 550 ppm) for two growing seasons. The influence of two different nitrogen (N) fertilisation levels (adequate N supply [N100] and nearly 50% of adequate N supply [N50]) were studied as well. A significant effect was observed for the crude protein content, which declined at FACE condition in a range of 8-16 g kg(-1) in wheat and of 10-20 g kg(-1) in barley. A reduced N fertilisation level resulted in a strong reduction of crude protein concentration in both cereal species. In wheat, a decrease in N supply significantly enhanced the concentration of starch and crude fibre. In barley, only the concentration of fructose increased under FACE condition and reduced N fertilisation. The FACE did not have major effects on the concentrations of minerals, while the influence of N fertilisation was different for both cereals. Whereas no effects could be observed for barley, a reduced N supply caused a significant reduction in concentrations of zinc, manganese and iron in wheat. Furthermore, an undirected effect of atmospheric CO2 and N fertilisation levels were found for the amino acid concentrations. Based on these results, future scenarios of climate change would have an impact on the nutritional value of cereal grains.

  1. DNA damage in lung cells in vivo and in vitro by 1,3-butadiene and nitrogen dioxide and their photochemical reaction products.

    Science.gov (United States)

    Walles, S A; Victorin, K; Lundborg, M

    1995-04-01

    A UV-irradiated mixture of 1,3-butadiene and nitrogen dioxide (NO2) was tested for its potency to induce DNA damage measured as single-strand breaks (SSB) in lungs of mice. Both gases were also tested separately. After 16 h exposure a UV-irradiated mixture of 40 ppm butadiene + 20 ppm NO2, but not 20 ppm butadiene + 10 ppm NO2 + UV, induced a significant increase in SSB as measured by the alkaline unwinding technique. There was no increase in the level of SSB using the alkaline elution technique during the same testing conditions. However, after 5 h exposure to 60 ppm butadiene + 30 ppm NO2 + UV both methods demonstrated a significant increase in SSB. Mice were also exposed to butadiene at 80 and 200 ppm for 16 h and at 500 ppm for 5 h. DNA damage was demonstrated in both liver and lung after 5 and 16 h (only at 200 ppm) of exposure using the unwinding technique. Using the alkaline elution assay, a significant increase in the level of SSB in lung and liver was found only after 5 h of exposure. When mice were exposed to 30 ppm NO2 for 16 h or 50 ppm for 5 h, a significant increase in SSB was found with the unwinding technique. Alveolar macrophages from mice were also exposed in vitro to the gas mixture and to butadiene and NO2 separately. In these experiments, the DNA damage was studied with the unwinding technique. A significant effect was demonstrated with 40 ppm butadiene + 20 ppm NO2 + UV. NO2 itself contributed to some extent to the increase. Reasons for the discrepancies between the unwinding and the alkaline elution techniques are discussed.

  2. New (p, {rho}, T) data for carbon dioxide - Nitrogen mixtures from (250 to 400) K at pressures up to 20 MPa

    Energy Technology Data Exchange (ETDEWEB)

    Mondejar, M.E.; Martin, M.C. [Grupo de Termodinamica y Calibracion (TERMOCAL), Dpto. Ingenieria Energetica y Fluidomecanica, Escuela de Ingenierias Industriales, Universidad de Valladolid, Paseo del Cauce, 59, E-47011 Valladolid (Spain); Span, R. [Lehrstuhl fuer Thermodynamik, Fakultaet fuer Maschinenbau Gebaeude IB, Ebene 5, Ruhr-Universitaet Bochum, Universitaetsstr. 150, 44780 Bochum (Germany); Chamorro, C.R., E-mail: cescha@eis.uva.es [Grupo de Termodinamica y Calibracion (TERMOCAL), Dpto. Ingenieria Energetica y Fluidomecanica, Escuela de Ingenierias Industriales, Universidad de Valladolid, Paseo del Cauce, 59, E-47011 Valladolid (Spain)

    2011-12-15

    Highlights: > Densities of two mixtures of nitrogen and carbon dioxide are reported. > Experimental data are compared with calculated densities from the equation of state. > Experimental data agree with the equation of state for low pressures above 300 K. > The equation of state shows higher deviations than expected at high pressures. - Abstract: Comprehensive (p, {rho}, T) measurements on two binary mixtures (0.10 CO{sub 2} + 0.90 N{sub 2} and 0.15 CO{sub 2} + 0.85 N{sub 2}) were carried out in the gas phase at seven isotherms between (250 and 400) K and pressures up to 20 MPa using a single sinker densimeter with magnetic suspension coupling. A total of 69 (p, {rho}, T) data for the first mixture and 69 (p, {rho}, T) data for the second are presented in this article. The uncertainty in density was estimated to be (0.02 to 0.15)%, while the uncertainty in temperature was 3.9 mK and the uncertainty in pressure was less than 0.015% (coverage factor k = 2). Experimental results were compared with densities calculated from the GERG equation of state and with data reported by other authors for similar mixtures. Results yielded that, while deviations between experimental data and values calculated from the GERG equation were lower than 0.05% in density for low pressures, the relative error at high pressures and low temperatures increased to about (0.2 to 0.3)%. The main aim of this work was to contribute to an accurate density data base for CO{sub 2}/N{sub 2} mixtures and to check or improve equations of state existing for these binary mixtures.

  3. Predicting residential indoor concentrations of nitrogen dioxide, fine particulate matter, and elemental carbon using questionnaire and geographic information system based data

    Science.gov (United States)

    Baxter, Lisa K.; Clougherty, Jane E.; Paciorek, Christopher J.; Wright, Rosalind J.; Levy, Jonathan I.

    Previous studies have identified associations between traffic-related air pollution and adverse health effects. Most have used measurements from a few central ambient monitors and/or some measure of traffic as indicators of exposure, disregarding spatial variability and factors influencing personal exposure-ambient concentration relationships. This study seeks to utilize publicly available data (i.e., central site monitors, geographic information system, and property assessment data) and questionnaire responses to predict residential indoor concentrations of traffic-related air pollutants for lower socioeconomic status (SES) urban households. As part of a prospective birth cohort study in urban Boston, we collected indoor and outdoor 3-4 day samples of nitrogen dioxide (NO 2) and fine particulate matter (PM 2.5) in 43 low SES residences across multiple seasons from 2003 to 2005. Elemental carbon (EC) concentrations were determined via reflectance analysis. Multiple traffic indicators were derived using Massachusetts Highway Department data and traffic counts collected outside sampling homes. Home characteristics and occupant behaviors were collected via a standardized questionnaire. Additional housing information was collected through property tax records, and ambient concentrations were collected from a centrally located ambient monitor. The contributions of ambient concentrations, local traffic and indoor sources to indoor concentrations were quantified with regression analyses. PM 2.5 was influenced less by local traffic but had significant indoor sources, while EC was associated with traffic and NO 2 with both traffic and indoor sources. Comparing models based on covariate selection using p-values or a Bayesian approach yielded similar results, with traffic density within a 50 m buffer of a home and distance from a truck route as important contributors to indoor levels of NO 2 and EC, respectively. The Bayesian approach also highlighted the uncertanity in the

  4. Four-electron deoxygenative reductive coupling of carbon monoxide at a single metal site

    Science.gov (United States)

    Buss, Joshua A.; Agapie, Theodor

    2016-01-01

    Carbon dioxide is the ultimate source of the fossil fuels that are both central to modern life and problematic: their use increases atmospheric levels of greenhouse gases, and their availability is geopolitically constrained. Using carbon dioxide as a feedstock to produce synthetic fuels might, in principle, alleviate these concerns. Although many homogeneous and heterogeneous catalysts convert carbon dioxide to carbon monoxide, further deoxygenative coupling of carbon monoxide to generate useful multicarbon products is challenging. Molybdenum and vanadium nitrogenases are capable of converting carbon monoxide into hydrocarbons under mild conditions, using discrete electron and proton sources. Electrocatalytic reduction of carbon monoxide on copper catalysts also uses a combination of electrons and protons, while the industrial Fischer-Tropsch process uses dihydrogen as a combined source of electrons and electrophiles for carbon monoxide coupling at high temperatures and pressures. However, these enzymatic and heterogeneous systems are difficult to probe mechanistically. Molecular catalysts have been studied extensively to investigate the elementary steps by which carbon monoxide is deoxygenated and coupled, but a single metal site that can efficiently induce the required scission of carbon-oxygen bonds and generate carbon-carbon bonds has not yet been documented. Here we describe a molybdenum compound, supported by a terphenyl-diphosphine ligand, that activates and cleaves the strong carbon-oxygen bond of carbon monoxide, enacts carbon-carbon coupling, and spontaneously dissociates the resulting fragment. This complex four-electron transformation is enabled by the terphenyl-diphosphine ligand, which acts as an electron reservoir and exhibits the coordinative flexibility needed to stabilize the different intermediates involved in the overall reaction sequence. We anticipate that these design elements might help in the development of efficient catalysts for

  5. Flexible substrates as basis for photocatalytic reduction of carbon dioxide

    DEFF Research Database (Denmark)

    Jensen, Jacob; Mikkelsen, Mette; Krebs, Frederik C

    2011-01-01

    A photocatalytic system for converting carbon dioxide into carbon monoxide was designed and constructed. The system relies on thin films of the photocatalyst prepared at low temperature using spray coating. We formulated inks based on the well-known photocatalyst titanium dioxide and characterized...

  6. Effect of irrigation, nitrogen application, and a nitrification inhibitor on nitrous oxide, carbon dioxide and methane emissions from an olive (Olea europaea L.) orchard

    Energy Technology Data Exchange (ETDEWEB)

    Maris, S.C., E-mail: stefania@macs.udl.cat [University of Lleida, Environment and Soil Science Department, Av. Alcalde Rovira Roure 191, E-25198 Lleida (Spain); Teira-Esmatges, M.R. [University of Lleida, Environment and Soil Science Department, Av. Alcalde Rovira Roure 191, E-25198 Lleida (Spain); Arbonés, A.; Rufat, J. [Programa Ús Eficient de l’Aigua, Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Parc Científic i Tecnològic Agroalimentari de Lleida (PCiTAL). Parc de Gardeny, Edifici Fruitcentre, E-2503 Lleida (Spain)

    2015-12-15

    Drip irrigation combined with nitrogen (N) fertigation is applied in order to save water and improve nutrient efficiency. Nitrification inhibitors reduce greenhouse gas emissions. A field study was conducted to compare the emissions of nitrous oxide (N{sub 2}O), carbon dioxide (CO{sub 2}) and methane (CH{sub 4}) associated with the application of N fertiliser through fertigation (0 and 50 kg N ha{sup −1}), and 50 kg N ha{sup −1} + nitrification inhibitor in a high tree density Arbequina olive orchard. Spanish Arbequina is the most suited variety for super intensive olive groves. This system allows reducing production costs and increases crop yield. Moreover its oil has excellent sensorial features. Subsurface drip irrigation markedly reduced N{sub 2}O and N{sub 2}O + N{sub 2} emissions compared with surface drip irrigation. Fertiliser application significantly increased N{sub 2}O + N{sub 2}, but not N{sub 2}O emissions. Denitrification was the main source of N{sub 2}O. The N{sub 2}O losses (calculated as emission factor) ranging from − 0.03 to 0.14% of the N applied, were lower than the IPCC (2007) values. The N{sub 2}O + N{sub 2} losses were the largest, equivalent to 1.80% of the N applied, from the 50 kg N ha{sup −1} + drip irrigation treatment which resulted in water filled pore space > 60% most of the time (high moisture). Nitrogen fertilisation significantly reduced CO{sub 2} emissions in 2011, but only for the subsurface drip irrigation strategies in 2012. The olive orchard acted as a net CH{sub 4} sink for all the treatments. Applying a nitrification inhibitor (DMPP), the cumulative N{sub 2}O and N{sub 2}O + N{sub 2} emissions were significantly reduced with respect to the control. The DMPP also inhibited CO{sub 2} emissions and significantly increased CH{sub 4} oxidation. Considering global warming potential, greenhouse gas intensity, cumulative N{sub 2}O emissions and oil production, it can be concluded that applying DMPP with 50 kg N ha{sup −1

  7. 40 CFR Appendix S to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Nitrogen...

    Science.gov (United States)

    2010-07-01

    ... Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) S Appendix S to Part 50 Protection... National Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) 1. General (a) This... national ambient air quality standards for oxides of nitrogen as measured by nitrogen dioxide (“NO2...

  8. A transportable spectrometer for in situ and local measurements of iodine monoxide at mixing ratios in the 10-14 range

    Science.gov (United States)

    Méjean, Guillaume; Grilli, Roberto; Abd Alrahman, Chadi; Ventrillard, Irène; Kassi, Samir; Romanini, Daniele

    2012-06-01

    We present a robust, compact, and transportable instrument that measures the iodine monoxide atmospheric radical at extremely low concentration, down to 40 ppqv (parts per quadrillion by volume, 1:1015). As nitrogen dioxide is strongly absorbed in the same spectral region it could be simultaneously measured down to 4 pptv (parts per trillion by volume, 1:1012). Relying on "mode locked cavity-enhanced absorption spectroscopy," the instrument makes use of a free-running commercial femtosecond Titane Saphir laser. We demonstrate that this multiplex detection scheme provides shot noise limited spectra for acquisition times as long as 5 min. Moreover, this instrument is very versatile as it can be potentially tuned from the infrared to the ultraviolet (1080-340 nm) to reach various molecular absorptions. It has been recently deployed at the Station Biologique de Roscoff on the North West Atlantic coast of France.

  9. Carbon Monoxide (CO) Poisoning Prevention

    Science.gov (United States)

    ... Recommend on Facebook Tweet Share Compartir When power outages occur after severe weather (such as winter storms, hurricanes or tornadoes), using alternative sources of power can cause carbon monoxide (CO) to build up in a ...

  10. Carbon Monoxide Mixing Ratio System

    Data.gov (United States)

    Oak Ridge National Laboratory — The Southern Great Plains (SGP) Carbon Monoxide (CO) system provides high-precision atmospheric concentration measurements of CO mixing ratio (ppbv dry air) every 10...

  11. 气提法去除油田污水中二氧化碳气体的实验研究%Experiment research on removal of carbon dioxide in oily wastewater by nitrogen gas stripping

    Institute of Scientific and Technical Information of China (English)

    杨向平; 曲虎; 刘静; 马梓涵

    2011-01-01

    Nitrogen gas stripper is used to remove the carbon dioxide from oily wastewater in this paper. The effects of gas-liquid ratio,pH value,temperature and oil content on the removal efficiency of carbon dioxide are carried out. The optimal condition is shown as follows;5: 1 of the gas-liquid ratio,301 of the temperature and 5 of the pH value. The removal rate of carbon dioxide from wastewater can be over 98%. The relative higher temperature and lower oil content help to enhance the carbon dioxide removal rate for the nitrogen gas stripper. The quality of the wastewater treated by nitrogen gas stripping is greatly improved. The carbon dioxide mass content can be decreased to 2 mg /L. The pH value of the stripped wastewater can be over 7. The corrosion rate of the carbon steel can be decreased to less than 0.02 mm/a.%采用氮气气提装置处理油田污水中溶解的CO2气体,考察了气液比、温度、pH及含油量对CO2去除效果的影响.结果表明,气提法去除油田污水中的CO2效果明显,在气液比为5:1、温度为30℃、pH为5条件下,污水中的CO2去除率可达98%以上;升高温度、降低污水中的含油量有助于增强氮气气提对CO2的去除效果;处理后的污水CO2质量浓度降到2 mg/L,pH升高到7,碳钢的腐蚀速率降到0.02 mm/a以下.

  12. The association between the incidence of postmenopausal breast cancer and concentrations at street-level of nitrogen dioxide and ultrafine particles.

    Science.gov (United States)

    Goldberg, Mark S; Labrèche, France; Weichenthal, Scott; Lavigne, Eric; Valois, Marie-France; Hatzopoulou, Marianne; Van Ryswyk, Keith; Shekarrizfard, Maryam; Villeneuve, Paul J; Crouse, Daniel; Parent, Marie-Élise

    2017-10-01

    There is scant information as to whether traffic-related air pollution is associated with the incidence of breast cancer. Nitrogen dioxide (NO2) and ultrafine particles (UFPs, groups. Concentrations of NO2 and UFPs were estimated using two separate land-use regression models. Exposures were assigned to residential locations at the time of recruitment, and we identified residential histories of women who had lived in these residences for 10 years or more. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression models adjusting for individual-level and ecological covariates. We assessed the functional form of NO2 and UFP exposures using natural cubic splines. We found that the functional form of the response functions between incident postmenopausal breast cancer and concentrations of NO2 and UFPs were consistent with linearity. For NO2, we found increasing risks of breast cancer for all subjects combined and stronger associations when analyses were restricted to those women who had lived at their current address for 10 years or more. Specifically, the OR, adjusted for personal covariates, per increase in the interquartile range (IQR=3.75 ppb) of NO2 was 1.08 (95%CI: 0.92-1.27). For women living in their homes for 10 years or more, the adjusted OR was 1.17 (95%CI: 0.93-1.46; IQR=3.84 ppb); for those not living at that home 10 years before the study, it was 0.93 (95%CI: 0.64, 1.36; IQR=3.65 ppb). For UFPs, the ORs were lower than for NO2, with little evidence of association in any of the models or sub-analyses and little variability in the ORs (about 1.02 for an IQR of ~3500cm(-3)). On the other hand, we found higher ORs amongst cases with positive oestrogen and progesterone receptor status; namely for NO2, the OR was 1.13 (95%CI: 0.94-1.35) and for UFPs it was 1.05 (95%CI: 0.96-1.14). Our findings suggest that exposure to ambient NO2 and UFPs may increase the risk of incident postmenopausal breast cancer especially amongst cases

  13. Changes in Transportation-Related Air Pollution Exposures by Race-Ethnicity and Socioeconomic Status: Outdoor Nitrogen Dioxide in the United States in 2000 and 2010.

    Science.gov (United States)

    Clark, Lara P; Millet, Dylan B; Marshall, Julian D

    2017-09-14

    Disparities in exposure to air pollution by race-ethnicity and by socioeconomic status have been documented in the United States, but the impacts of declining transportation-related air pollutant emissions on disparities in exposure have not been studied in detail. This study was designed to estimate changes over time (2000 to 2010) in disparities in exposure to outdoor concentrations of a transportation-related air pollutant, nitrogen dioxide (NO2), in the United States. We combined annual average NO2 concentration estimates from a temporal land use regression model with Census demographic data to estimate outdoor exposures by race-ethnicity, socioeconomic characteristics (income, age, education), and by location (region, state, county, urban area) for the contiguous United States in 2000 and 2010. Estimated annual average NO2 concentrations decreased from 2000 to 2010 for all of the race-ethnicity and socioeconomic status groups, including a decrease from 17.6 ppb to 10.7 ppb (-6.9 ppb) in nonwhite [non-(white alone, non-Hispanic)] populations, and 12.6 ppb to 7.8 ppb (-4.7 ppb) in white (white alone, non-Hispanic) populations. In 2000 and 2010, disparities in NO2 concentrations were larger by race-ethnicity than by income. Although the national nonwhite-white mean NO2 concentration disparity decreased from a difference of 5.0 ppb in 2000 to 2.9 ppb in 2010, estimated mean NO2 concentrations remained 37% higher for nonwhites than whites in 2010 (40% higher in 2000), and nonwhites were 2.5 times more likely than whites to live in a block group with an average NO2 concentration above the WHO annual guideline in 2010 (3.0 times more likely in 2000). Findings suggest that absolute NO2 exposure disparities by race-ethnicity decreased from 2000 to 2010, but relative NO2 exposure disparities persisted, with higher NO2 concentrations for nonwhites than whites in 2010. https://doi.org/10.1289/EHP959.

  14. Inherent calibration of a blue LED-CE-DOAS instrument to measure iodine oxide, glyoxal, methyl glyoxal, nitrogen dioxide, water vapour and aerosol extinction in open cavity mode

    Directory of Open Access Journals (Sweden)

    R. Thalman

    2010-12-01

    Full Text Available The combination of Cavity Enhanced Absorption Spectroscopy (CEAS with broad-band light sources (e.g. Light-Emitting Diodes, LEDs lends itself to the application of cavity enhanced Differential Optical Absorption Spectroscopy (CE-DOAS to perform sensitive and selective point measurements of multiple trace gases and aerosol extinction with a single instrument. In contrast to other broad-band CEAS techniques, CE-DOAS relies only on the measurement of relative intensity changes, i.e. does not require knowledge of the light intensity in the absence of trace gases and aerosols (I0. We have built a prototype LED-CE-DOAS instrument in the blue spectral range (420–490 nm to measure nitrogen dioxide (NO2, glyoxal (CHOCHO, methyl glyoxal (CH3COCHO, iodine oxide (IO, water vapour (H2O and oxygen dimers (O4. We demonstrate the first direct detection of methyl glyoxal, and the first CE-DOAS detection of CHOCHO and IO. The instrument is further inherently calibrated for light extinction from the cavity by observing O4 or H2O (at 477 nm and 443 nm and measuring the pressure, relative humidity and temperature independently. This approach is demonstrated by experiments where laboratory aerosols of known size and refractive index were generated and their extinction measured. The measured extinctions were then compared to the theoretical extinctions calculated using Mie theory (3–7 × 10−7cm−1. Excellent agreement is found from both the O4 and H2O retrievals. This enables the first inherently calibrated CEAS measurement at blue wavelengths in open cavity mode, and eliminates the need for sampling lines to supply air to the cavity, i.e., keep the cavity enclosed and/or aerosol free. Measurements in open cavity mode are demonstrated for CHOCHO, CH3COCHO, NO2, H2O and aerosol extinction. Our prototype

  15. Simulation study to determine the feasibility of injecting hydrogen sulfide, carbon dioxide and nitrogen gas injection to improve gas and oil recovery oil-rim reservoir

    Science.gov (United States)

    Eid, Mohamed El Gohary

    This study is combining two important and complicated processes; Enhanced Oil Recovery, EOR, from the oil rim and Enhanced Gas Recovery, EGR from the gas cap using nonhydrocarbon injection gases. EOR is proven technology that is continuously evolving to meet increased demand and oil production and desire to augment oil reserves. On the other hand, the rapid growth of the industrial and urban development has generated an unprecedented power demand, particularly during summer months. The required gas supplies to meet this demand are being stretched. To free up gas supply, alternative injectants to hydrocarbon gas are being reviewed to support reservoir pressure and maximize oil and gas recovery in oil rim reservoirs. In this study, a multi layered heterogeneous gas reservoir with an oil rim was selected to identify the most optimized development plan for maximum oil and gas recovery. The integrated reservoir characterization model and the pertinent transformed reservoir simulation history matched model were quality assured and quality checked. The development scheme is identified, in which the pattern and completion of the wells are optimized to best adapt to the heterogeneity of the reservoir. Lateral and maximum block contact holes will be investigated. The non-hydrocarbon gases considered for this study are hydrogen sulphide, carbon dioxide and nitrogen, utilized to investigate miscible and immiscible EOR processes. In November 2010, re-vaporization study, was completed successfully, the first in the UAE, with an ultimate objective is to examine the gas and condensate production in gas reservoir using non hydrocarbon gases. Field development options and proces schemes as well as reservoir management and long term business plans including phases of implementation will be identified and assured. The development option that maximizes the ultimate recovery factor will be evaluated and selected. The study achieved satisfactory results in integrating gas and oil

  16. Effects of nitrogen dioxide on the expression of intercellular adhesion molecule-1, neutrophil adhesion, and cytotoxicity: studies in human bronchial epithelial cells.

    Science.gov (United States)

    Ayyagari, Vijayalakshmi N; Januszkiewicz, Adolph; Nath, Jayasree

    2007-02-01

    Nitrogen Dioxide (NO2) is a product of high-temperature combustion and an environmental oxidant of concern. We have recently reported that early changes in NO2-exposed human bronchial epithelial cells are causally linked to increased generation of proinflammatory mediators, such as nitric oxide/nitrite and cytokines like interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha and IL-8. The objective of the present in vitro study was to further delineate the cellular mechanisms of NO2-mediated toxicity, and to define the nature of cell death that ensues upon exposure of normal human bronchial epithelial (NHBE) cells to a brief high dose of NO2. Our results demonstrate that the NHBE cells undergo apoptotic cell death during the early post-NO2 period, but this is independent of any significant increase in caspase-3 activity. However, necrotic cell death was more prevalent at later time intervals. Interestingly, an increased expression of HO-1, a redox-sensitive stress protein, was observed in NO2-exposed NHBE cells at 24 h. Since neutrophils (PMNs) play an active role in acute lung inflammation and resultant oxidative injury, we also investigated changes in human PMN-NHBE cell interactions. As compared to normal cells, increased adhesion of PMNs to NO2-exposed cells was observed, which resulted in an increased NHBE cell death. The latter was also increased in the presence of IL-8 and TNF-alpha + interferon (IFN)-gamma, which correlated with upregulation of intercellular adhesion molecule-1 (ICAM-1). Our results confirmed an involvement of nitric oxide (NO) in NO2-induced cytotoxicity. By using NO synthase inhibitors such as L-NAME and 3-aminoguanidine (AG), a significant decrease in cell death, PMN adhesion, and ICAM-1 expression was observed. These findings indicate a role for the L-arginine/NO synthase pathway in the observed NO2-mediated toxicity in NHBE cells. Therapeutic strategies aimed at controlling excess generation of NO and/or inflammatory cytokines may

  17. Association of indoor nitrogen dioxide with respiratory symptoms in children: application of measurement error correction techniques to utilize data from multiple surrogates.

    Science.gov (United States)

    Li, Ruifeng; Weller, Edie; Dockery, Douglas W; Neas, Lucas M; Spiegelman, Donna

    2006-07-01

    In 1991, Neas et al. reported that indoor nitrogen dioxide (NO(2)), a byproduct of high-temperature combustion, was significantly associated with lower respiratory symptoms among a cohort of 1,159 white children aged 7-11 years in six US cities studied from 1983 to 1988. For each 15 p.p.b. increment of NO(2), the multivariate adjusted odds ratio (OR) was 1.4 (95% confidence interval (CI)=[1.1, 1.7]). Although indoor NO(2) concentration in the ambient air was assessed only in a subset of the children, the prevalence of lower respiratory symptoms and surrogate exposure variables were available in all of the children at the time of the indoor monitoring program. This paper evaluates the effect of indoor NO(2) exposure on the annual risk of lower respiratory symptoms by applying a regression calibration method to the 2,891 children in the overall study with complete covariate and outcome data, 1,137 of whom had NO(2) directly measured and 1,754 of whom only surrogate exposure data were available. An estimate of the indoor annual NO(2) exposure effect (p.p.b.) is obtained, which is adjusted for measurement error induced by the use of surrogate NO(2) sources among the 1,754. These sources include the presence of a gas stove with or without a pilot light, the presence of a kerosene space heater, the presence of a wood stove, and the usage of a stove for heating, and residential characteristics, including fan usage for kitchen ventilation and the total number of rooms in the home. After adjusting for age, gender, city, parental history of respiratory diseases, and smoking inside the children's home (packs/day), a 15-p.p.b. increment in NO(2) exposure was found to be associated with a significant 50% increased annual risk of lower respiratory symptoms (OR=1.5, 95% CI=[1.2, 1.8]). Simulation results indicated that, under conditions similar to those observed in these data, the estimator is unbiased and has a coverage probability close to the nominal value. Using the

  18. Participant-based monitoring of indoor and outdoor nitrogen dioxide, volatile organic compounds, and polycyclic aromatic hydrocarbons among MICA-Air households

    Science.gov (United States)

    Johnson, Markey M.; Williams, Ron; Fan, Zhihua; Lin, Lin; Hudgens, Edward; Gallagher, Jane; Vette, Alan; Neas, Lucas; Özkaynak, Halûk

    2010-12-01

    The Mechanistic Indicators of Childhood Asthma (MICA) study in Detroit, Michigan introduced a participant-based approach to reduce the resource burden associated with collection of indoor and outdoor residential air sampling data. A subset of participants designated as MICA-Air conducted indoor and outdoor residential sampling of nitrogen dioxide (NO 2), volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). This participant-based methodology was subsequently adapted for use in the Vanguard phase of the U.S. National Children's Study. The current paper examines residential indoor and outdoor concentrations of these pollutant species among health study participants in Detroit, Michigan. Pollutants measured under MICA-Air agreed well with other studies and continuous monitoring data collected in Detroit. For example, NO 2 and BTEX concentrations reported for other Detroit area monitoring were generally within 10-15% of indoor and outdoor concentrations measured in MICA-Air households. Outdoor NO 2 concentrations were typically higher than indoor NO 2 concentration among MICA-Air homes, with a median indoor/outdoor (I/O) ratio of 0.6 in homes that were not impacted by environmental tobacco smoke (ETS) during air sampling. Indoor concentrations generally exceeded outdoor concentrations for VOC and PAH species measured among non-ETS homes in the study. I/O ratios for BTEX species (benzene, toluene, ethylbenzene, and m/p- and o-xylene) ranged from 1.2 for benzene to 3.1 for toluene. Outdoor NO 2 concentrations were approximately 4.5 ppb higher on weekdays versus weekends. As expected, I/O ratios pollutants were generally higher for homes impacted by ETS. These findings suggest that participant-based air sampling can provide a cost-effective alternative to technician-based approaches for assessing indoor and outdoor residential air pollution in community health studies. We also introduced a technique for estimating daily concentrations at each

  19. Comparison of ambient airborne PM₂.₅, PM₂.₅ absorbance and nitrogen dioxide ratios measured in 1999 and 2009 in three areas in Europe.

    Science.gov (United States)

    Durant, John L; Beelen, Rob; Eeftens, Marloes; Meliefste, Kees; Cyrys, Josef; Heinrich, Joachim; Bellander, Tom; Lewné, Marie; Brunekreef, Bert; Hoek, Gerard

    2014-07-15

    Epidemiological studies often use nitrogen dioxide (NO2) or proximity to roads to characterize exposure to more health-relevant pollutants (e.g., fine particles or black carbon aerosol) in vehicle exhaust. Due to the introduction of diesel-soot filters, particle-to-NO2 ratios may have decreased, but little information is available about these ratios over time. Our study aim was to evaluate the change in particle-to-NO2 ratios between 1999 and 2009. We compared data collected during measurement campaigns in 1999 and 2009 from Munich, the Netherlands, and Stockholm. Traffic-impacted and urban and regional background sites were studied during each campaign. The same pollutants were measured in each campaign (mass concentration of particles ≤ 2.5 microns in diameter (PM2.5), PM2.5 absorbance (a marker for black carbon), and NO2) using the same methods except for NO2: Palmes tubes were used in 1999 and Ogawa badges in 2009. Both NO2 methods were validated against side-by-side chemiluminescence measurements. The levels of PM2.5 absorbance and PM2.5 were significantly lower (plevels were not significantly different in the three areas in 2009 compared to 1999. Statistically-significant decreases between 1999 and 2009 pollutant ratios in the Netherlands (PM2.5 absorbance/NO2 and PM2.5/NO2) and in Stockholm (PM2.5 absorbance/NO2 and PM2.5 absorbance/PM2.5) were observed. Smaller decreases in these ratios were observed in Munich. The contrast between traffic and urban background locations was larger in 2009 than 1999 for NO2, whereas it was smaller for PM2.5 absorbance and PM2.5. The lower PM2.5 absorbance/NO2 and PM2.5/NO2 ratios in 2009 is likely explained by the introduction of oxidative particle filters for diesel vehicles that reduce particles but produce NO2. The changed contrasts may affect estimates of health effects related to NO2 as a marker of proximity to roads. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Inherent calibration of a novel LED-CE-DOAS instrument to measure iodine oxide, glyoxal, methyl glyoxal, nitrogen dioxide, water vapour and aerosol extinction in open cavity mode

    Science.gov (United States)

    Thalman, R.; Volkamer, R.

    2010-06-01

    The combination of Cavity Enhanced Absorption Spectroscopy (CEAS) with broad-band light sources (e.g. Light-Emitting Diodes, LEDs) lends itself to the application of cavity enhanced Differential Optical Absorption Spectroscopy (CE-DOAS) to perform sensitive and selective point measurements of multiple trace gases and aerosol extinction with a single instrument. In contrast to other broad-band CEAS techniques, CE-DOAS relies only on the measurement of relative intensity changes, i.e. does not require knowledge of the light intensity in the absence of trace gases and aerosols (I0). We have built a prototype LED-CE-DOAS instrument in the blue spectral range (420-490 nm) to measure nitrogen dioxide (NO2), glyoxal (CHOCHO), methyl glyoxal (CH3COCHO), iodine oxide (IO), water vapour (H2O) and oxygen dimers (O4). We demonstrate the first CEAS detection of methyl glyoxal, and the first CE-DOAS detection of CHOCHO and IO. A further innovation consists in the measurement of extinction losses from the cavity, e.g. due to aerosols, at two wavelengths by observing O4 (477 nm) and H2O (443 nm) and measuring the pressure, relative humidity and temperature independently. This approach is demonstrated by experiments where laboratory aerosols of known size and refractive index were generated and their extinction measured. The measured extinctions were then compared to the theoretical extinctions calculated using Mie theory (3-7×10-7 cm-1). Excellent agreement is found from both the O4 and H2O retrievals. This enables the first inherently calibrated CEAS measurement in open cavity mode (mirrors facing the open atmosphere), and eliminates the need for sampling lines to supply air to the cavity, and/or keep the cavity enclosed and aerosol free. Measurements in open cavity mode are demonstrated for CHOCHO, CH3COCHO, NO2, H2O and aerosol extinction at 477 nm and 443 nm. Our prototype LED-CE-DOAS provides a low cost, yet research grade innovative instrument for applications in simulation

  1. Inherent calibration of a novel LED-CE-DOAS instrument to measure iodine oxide, glyoxal, methyl glyoxal, nitrogen dioxide, water vapour and aerosol extinction in open cavity mode

    Directory of Open Access Journals (Sweden)

    R. Thalman

    2010-06-01

    Full Text Available The combination of Cavity Enhanced Absorption Spectroscopy (CEAS with broad-band light sources (e.g. Light-Emitting Diodes, LEDs lends itself to the application of cavity enhanced Differential Optical Absorption Spectroscopy (CE-DOAS to perform sensitive and selective point measurements of multiple trace gases and aerosol extinction with a single instrument. In contrast to other broad-band CEAS techniques, CE-DOAS relies only on the measurement of relative intensity changes, i.e. does not require knowledge of the light intensity in the absence of trace gases and aerosols (I0. We have built a prototype LED-CE-DOAS instrument in the blue spectral range (420–490 nm to measure nitrogen dioxide (NO2, glyoxal (CHOCHO, methyl glyoxal (CH3COCHO, iodine oxide (IO, water vapour (H2O and oxygen dimers (O4. We demonstrate the first CEAS detection of methyl glyoxal, and the first CE-DOAS detection of CHOCHO and IO. A further innovation consists in the measurement of extinction losses from the cavity, e.g. due to aerosols, at two wavelengths by observing O4 (477 nm and H2O (443 nm and measuring the pressure, relative humidity and temperature independently. This approach is demonstrated by experiments where laboratory aerosols of known size and refractive index were generated and their extinction measured. The measured extinctions were then compared to the theoretical extinctions calculated using Mie theory (3–7×10-7 cm-1. Excellent agreement is found from both the O4 and H2O retrievals. This enables the first inherently calibrated CEAS measurement in open cavity mode (mirrors facing the open atmosphere, and eliminates the need for sampling lines to supply air to the cavity, and/or keep the cavity enclosed and aerosol free. Measurements in open cavity mode are demonstrated for CHOCHO, CH3COCHO, NO2, H2

  2. Inherent calibration of a blue LED-CE-DOAS instrument to measure iodine oxide, glyoxal, methyl glyoxal, nitrogen dioxide, water vapour and aerosol extinction in open cavity mode

    Science.gov (United States)

    Thalman, R.; Volkamer, R.

    2010-12-01

    The combination of Cavity Enhanced Absorption Spectroscopy (CEAS) with broad-band light sources (e.g. Light-Emitting Diodes, LEDs) lends itself to the application of cavity enhanced Differential Optical Absorption Spectroscopy (CE-DOAS) to perform sensitive and selective point measurements of multiple trace gases and aerosol extinction with a single instrument. In contrast to other broad-band CEAS techniques, CE-DOAS relies only on the measurement of relative intensity changes, i.e. does not require knowledge of the light intensity in the absence of trace gases and aerosols (I0). We have built a prototype LED-CE-DOAS instrument in the blue spectral range (420-490 nm) to measure nitrogen dioxide (NO2), glyoxal (CHOCHO), methyl glyoxal (CH3COCHO), iodine oxide (IO), water vapour (H2O) and oxygen dimers (O4). We demonstrate the first direct detection of methyl glyoxal, and the first CE-DOAS detection of CHOCHO and IO. The instrument is further inherently calibrated for light extinction from the cavity by observing O4 or H2O (at 477 nm and 443 nm) and measuring the pressure, relative humidity and temperature independently. This approach is demonstrated by experiments where laboratory aerosols of known size and refractive index were generated and their extinction measured. The measured extinctions were then compared to the theoretical extinctions calculated using Mie theory (3-7 × 10-7cm-1). Excellent agreement is found from both the O4 and H2O retrievals. This enables the first inherently calibrated CEAS measurement at blue wavelengths in open cavity mode, and eliminates the need for sampling lines to supply air to the cavity, i.e., keep the cavity enclosed and/or aerosol free. Measurements in open cavity mode are demonstrated for CHOCHO, CH3COCHO, NO2, H2O and aerosol extinction. Our prototype LED-CE-DOAS provides a low cost, yet research grade innovative instrument for applications in simulation chambers and in the open atmosphere.

  3. Glutamine Synthetases GLN1;2 and GLN2 in Relation to Arabidopsis Growth Response to Elevated Atmospheric Carbon Dioxide and Varying Nitrogen Forms

    DEFF Research Database (Denmark)

    Vurrakula, Swathi

    content while diluting nitrogen concentrations. Such a reduction in nitrogen concentration will affect plant response to stress and seed/grain yield. Glutamine synthetase (GS) is the central nitrogen-assimilatory enzyme, performing primary and secondary nitrogen assimilation, in response to environmental...... cues and adjusting it to the plant internal status. The two major types of GS include cytosolic GS1 (five isoforms in Arabidopsis, GLN1;1 to GLN1;5) and a single chloroplastic GS2. GS draws its substrates from carbon skeletons to synthesize amino acids. Thus, carbon and nitrogen metabolisms are closely...

  4. Modeling the Injection of Carbon Dioxide and Nitrogen into a Methane Hydrate Reservoir and the Subsequent Production of Methane Gas on the North Slope of Alaska

    Science.gov (United States)

    Garapati, N.; McGuire, P. C.; Liu, Y.; Anderson, B. J.

    2012-12-01

    HydrateResSim (HRS) is an open-source finite-difference reservoir simulation code capable of simulating the behavior of gas hydrate in porous media. The original version of HRS was developed to simulate pure methane hydrates, and the relationship between equilibrium temperature and pressure is given by a simple, 1-D regression expression. In this work, we have modified HydrateResSim to allow for the formation and dissociation of gas hydrates made from gas mixtures. This modification allows one to model the ConocoPhillips Ignik Sikumi #1 field test performed in early 2012 on the Alaska North Slope. The Ignik Sikumi #1 test is the first field-based demonstration of gas production through the injection of a mixture of carbon dioxide and nitrogen gases into a methane hydrate reservoir and thereby sequestering the greenhouse gas CO2 into hydrate form. The primary change to the HRS software is the added capability of modeling a ternary mixture consisting of CH4 + CO2 + N2 instead of only one hydrate guest molecule (CH4), therefore the new software is called Mix3HydrateResSim. This Mix3HydrateResSim upgrade to the software was accomplished by adding primary variables (for the concentrations of CO2 and N2), governing equations (for the mass balances of CO2 and N2), and phase equilibrium data. The phase equilibrium data in Mix3HydrateResSim is given as an input table obtained using a statistical mechanical method developed in our research group called the cell potential method. An additional phase state describing a two-phase Gas-Hydrate (GsH) system was added to consider the possibility of converting all available free water to form hydrate with injected gas. Using Mix3HydrateResSim, a methane hydrate reservoir with coexisting pure-CH4-hydrate and aqueous phases at 7.0 MPa and 5.5°C was modeled after the conditions of the Ignik Sikumi #1 test: (i) 14-day injection of CO2 and N2 followed by (ii) 30-day production of CH4 (by depressurization of the well). During the

  5. Nitrogen Dioxide-Induced Responses in Brassica campestris Seedlings: The Role of Hydrogen Peroxide in the Modulation of Antioxidative Level and Induced Resistance

    Institute of Scientific and Technical Information of China (English)

    MA Chun-yan; XU Xin; HAO Lin; CAO Jun

    2007-01-01

    This article investigates the responses of Brassica campestris seedlings to an acute level of nitrogen dioxide (NO2) exposure in a plant growth chamber, and examines whether pretreating plants with hydrogen peroxide (H2O2) will alleviate NO2-caused injury. Twenty-eight-day-old B. campestris plants sprayed with 10 mmol L-1 H2O2 aqueous solution (corresponding to approximate 1.0 mg H2O2 per single plant) were exposed to different concentrations of NO2 (0.25, 0.5, 1.0, and 2.0 μL L-1, respectively) for 24 h under controlled environment. To measure the plant biomass, the plants were fumigated with the same NO2 concentrations as mentioned above for 7 h per day (8.00-15.00) for 7 days. As a control, charcoal filtered air alone was applied. Data were collected on plant biomass, total chlorophyll, photosynthetic rate, stomatal conductance, nitrate and nitrate reductase (NR), antioxidative enzymes, ascorbate (ASA), and malondialdehyde (MDA),immediately after exposure. The results showed that exposure to a moderate dose of NO2 (e.g., 0.25 μL L-1) had a favorable effect on plants, and the dry weight of the above-ground part increased, whereas the exposure to high NO2 concentrations (e.g., 0.5 μL L-1 or higher) caused a reduction in the plant biomass and the total chlorophyll, when compared with the control. In addition, at 0.5 μL L-1 or higher NO2 concentrations, prominent increases in the MDA level and superoxide dismutase (SOD) and NR activities were observed. Exposure to 1 μL L-1 and higher NO2 resulted in necroses appearing on older leaves, and an increase in catalase (CAT) activity, decrease in ASA content, increased accumulation of NO3-, and reduction in photosynthesis, when compared with the controls. No changes were detected in stomatal conductance under NO2 fumigation. The pretreatment with 10 mmol L-1 H2O2 alleviated significantly NO2- caused biomass decrease and photosynthetic inhibition when compared with H2O2-untreated plants. Under NO2 fumigation, further

  6. (Carbon monoxide metabolism by photosynthetic bacteria)

    Energy Technology Data Exchange (ETDEWEB)

    1989-01-01

    Research continued on the metabolism of carbon monoxide by Rhodospirillum rubrum. This report discusses progress on the activity, induction, inhibition, and spectroscopic analysis of the enzyme Carbon Monoxide Dehydrogenase. (CBS)

  7. Carbon Monoxide Silicate Reduction System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Carbon Monoxide Silicate Reduction System (COSRS) is an innovative method that for the first time uses the strong reductant carbon monoxide to both reduce iron...

  8. Simultaneous effect of nitrate (NO3- concentration, carbon dioxide (CO2 supply and nitrogen limitation on biomass, lipids, carbohydrates and proteins accumulation in Nannochloropsis oculata

    Directory of Open Access Journals (Sweden)

    Aarón Millán-Oropeza

    2015-03-01

    Full Text Available Biodiesel from microalgae is a promising technology. Nutrient limitation and the addition of CO2 are two strategies to increase lipid content in microalgae. There are two different types of nitrogen limitation, progressive and abrupt limitation. In this work, the simultaneous effect of initial nitrate concentration, addition of CO2, and nitrogen limitation on biomass, lipid, protein and carbohydrates accumulation were analyzed. An experimental design was established in which initial nitrogen concentration, culture time and CO2 aeration as independent numerical variables with three levels were considered. Nitrogen limitation was taken into account as a categorical independent variable. For the experimental design, all the experiments were performed with progressive nitrogen limitation. The dependent response variables were biomass, lipid production, carbohydrates and proteins. Subsequently, comparison of both types of limitation i.e. progressive and abrupt limitation, was performed. Nitrogen limitation in a progressive mode exerted a greater effect on lipid accumulation. Culture time, nitrogen limitation and the interaction of initial nitrate concentration with nitrogen limitation had higher influences on lipids and biomass production. The highest lipid production and productivity were at 582 mgL-1 (49.7 % lipid, dry weight basis and 41.5 mgL-1d-1, respectively; under the following conditions: 250 mgL-1 of initial nitrate concentration, CO2 supply of 4% (v/v, 12 d of culturing and 2 d in state of nitrogen starvation induced by progressive limitation. This work presents a novel way to perform simultaneous analysis of the effect of the initial concentration of nitrate, nitrogen limitation, and CO2 supply on growth and lipid production of Nannochloropsis oculata, with the aim to produce potential biofuels feedstock.

  9. Database of normal human cerebral blood flow, cerebral blood volume, cerebral oxygen extraction fraction and cerebral metabolic rate of oxygen measured by positron emission tomography with {sup 15}O-labelled carbon dioxide or water, carbon monoxide and oxygen: a multicentre study in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hiroshi [Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita (Japan); Department of Nuclear Medicine and Radiology, Division of Brain Sciences, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-Machi, 980-8575, Aoba-Ku, Sendai (Japan); Kanno, Iwao [Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita (Japan); Kato, Chietsugu [Department of Nuclear Medicine, Hokkaido University School of Medicine, Sapporo (Japan); Sasaki, Toshiaki [Cyclotoron Research Center, Iwate Medical University, Morioka (Japan); Ishii, Kenji [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Tokyo (Japan); Ouchi, Yasuomi [Positron Medical Center, Hamamatsu Medical Center, Hamakita (Japan); Iida, Akihiko [Nagoya City Rehabilitation Center, Nagoya (Japan); Okazawa, Hidehiko [PET Unit, Research Institute, Shiga Medical Center, Moriyama (Japan); Hayashida, Kohei [Department of Radiology, National Cardiovascular Center, Suita, Osaka (Japan); Tsuyuguchi, Naohiro [Department of Neurosurgery, Osaka City University Medical School, Osaka (Japan); Ishii, Kazunari [Division of Imaging Research, Hyogo Institute for Aging Brain and Cognitive Disorders, Himeji, Hyogo (Japan); Kuwabara, Yasuo [Department of Radiology, Faculty of Medicine, Kyushu University, Fukuoka (Japan); Senda, Michio [Department of Image-based Medicine, Institute of Biomedical Research and Innovation, Kobe (Japan)

    2004-05-01

    Measurement of cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO{sub 2}) by positron emission tomography (PET) with oxygen-15 labelled carbon dioxide (C{sup 15}O{sub 2}) or {sup 15}O-labelled water (H{sub 2}{sup 15}O), {sup 15}O-labelled carbon monoxide (C{sup 15}O) and {sup 15}O-labelled oxygen ({sup 15}O{sub 2}) is useful for diagnosis and treatment planning in cases of cerebrovascular disease. The measured values theoretically depend on various factors, which may differ between PET centres. This study explored the applicability of a database of {sup 15}O-PET by examining between-centre and within-centre variation in values. Eleven PET centres participated in this multicentre study; seven used the steady-state inhalation method, one used build-up inhalation and three used bolus administration of C{sup 15}O{sub 2} (or H{sub 2}{sup 15}O) and {sup 15}O{sub 2}. All used C{sup 15}O for measurement of CBV. Subjects comprised 70 healthy volunteers (43 men and 27 women; mean age 51.8{+-}15.1 years). Overall mean{+-}SD values for cerebral cortical regions were: CBF=44.4{+-}6.5 ml 100 ml{sup -1} min{sup -1}; CBV=3.8{+-}0.7 ml 100 ml{sup -1}; OEF=0.44{+-}0.06; CMRO{sub 2}=3.3{+-}0.5 ml 100 ml{sup -1} min{sup -1}. Significant between-centre variation was observed in CBV, OEF and CMRO{sub 2} by one-way analysis of variance. However, the overall inter-individual variation in CBF, CBV, OEF and CMRO{sub 2} was acceptably small. Building a database of normal cerebral haemodynamics obtained by the{sup 15}O-PET methods may be practicable. (orig.)

  10. A Fleet of Low-Cost Sensor Based Air Quality Monitors Is Used to Measure Carbon Dioxide and Carbon Monoxide in Two Settings: In the Ambient Environment to Explore the Regional-Scale Spatial Variability of These Compounds Via a Distributed Network, and in Homes to Investigate How Heating during Winter Months can Impact Indoor Air Quality.

    Science.gov (United States)

    Casey, J. G.; Hannigan, M.; Collier, A. M.; Coffey, E.; Piedrahita, R.

    2016-12-01

    Affordable, small, portable, quiet tools to measure atmospheric trace gases and air quality enable novel experimental design and new findings. Members of the Hannigan Lab at the University of Colorado in Boulder have been working over the last few years to integrate emerging affordable gas sensors into such an air quality monitor. Presented here are carbon monoxide (CO) and carbon dioxide (CO2) measurements from two field experiments that utilized these tools. In the first experiment, ten air quality monitors were located northeast of Boulder throughout the Denver Julesburg oil and gas basin. The Colorado Department of Health and Environment has several air quality monitoring sites in this broader region, each in an Urban center. One goal of the experiment was to determine whether or not significant spatial variability of EPA criteria pollutants like CO, exists on a sub-regulatory monitoring grid scale. Another goal of the experiment was to compare rural sampling locations with urban sites. The monitors collected continuous data (sampling every 15 seconds) at each location over the course of several months. Our sensor calibration procedures are presented along with our observations and an analysis of the spatial and temporal variability in CO and CO2. In the second experiment, we used eight of our air quality monitors to better understand how home heating fuel type can impact indoor air quality in two communities on the Navajo Nation. We sought to compare air quality in homes using one of four different fuels for heat (wood, wood plus coal, pellet, and gas). There are many factors that contribute to indoor air quality and the impact of an emission source, like a woodstove, within a home. Having multiple, easily deployable, air quality monitors allowed us to account for many of these factors. We sampled four homes at a time, aiming for one home from each of our fuel groups in each sampling period. We sampled inside and outside of each home for a period of 3-4 days

  11. Carbon monoxide formation in tomatoes

    Energy Technology Data Exchange (ETDEWEB)

    Gladon, R.J.; Staby, G.L.

    1979-01-01

    Carbon monoxide (CO) is not emanated to any large extent from tomato fruits (Lycopersicon esculentum, Mill. cvs. Rutgers and Ohio MR-13), but is retained within the internal atmosphere. CO is found during all stages of fruit development, but no set pattern of CO concentration is evident.

  12. MOPITT Carbon Monoxide Over India

    Science.gov (United States)

    2002-01-01

    MOPITT observed high levels of carbon monoxide (red and yellow pixels) over the Indian sub-continent during March. These values are associated with industrial activity in the region just south of the Himalayan Mountains. Notice that to the north, the Himalayas are characterized by low values (blue pixels).

  13. Modelling impacts of changes in carbon dioxide concentration, climate and nitrogen deposition on carbon sequestration by European forests and forest soils

    NARCIS (Netherlands)

    Wamelink, G.W.W.; Wieggers, H.J.J.; Reinds, G.J.; Kros, J.; Mol-Dijkstra, J.P.; Oijen, van M.; Vries, de W.

    2009-01-01

    Changes in the Earth's atmosphere are expected to influence the growth, and therefore, carbon accumulation of European forests. We identify three major changes: (1) a rise in carbon dioxide concentration, (2) climate change, resulting in higher temperatures and changes in precipitation and (3) a

  14. Governing processes for reactive nitrogen compounds in the European atmosphere

    Science.gov (United States)

    Hertel, O.; Skjøth, C. A.; Reis, S.; Bleeker, A.; Harrison, R. M.; Cape, J. N.; Fowler, D.; Skiba, U.; Simpson, D.; Jickells, T.; Kulmala, M.; Gyldenkærne, S.; Sørensen, L. L.; Erisman, J. W.; Sutton, M. A.

    2012-12-01

    Reactive nitrogen (Nr) compounds have different fates in the atmosphere due to differences in the governing processes of physical transport, deposition and chemical transformation. Nr compounds addressed here include reduced nitrogen (NHx: ammonia (NH3) and its reaction product ammonium (NH4+)), oxidized nitrogen (NOy: nitrogen monoxide (NO) + nitrogen dioxide (NO2) and their reaction products) as well as organic nitrogen compounds (organic N). Pollution abatement strategies need to take into account the differences in the governing processes of these compounds when assessing their impact on ecosystem services, biodiversity, human health and climate. NOx (NO + NO2) emitted from traffic affects human health in urban areas where the presence of buildings increases the residence time in streets. In urban areas this leads to enhanced exposure of the population to NOx concentrations. NOx emissions generally have little impact on nearby ecosystems because of the small dry deposition rates of NOx. These compounds need to be converted into nitric acid (HNO3) before removal through deposition is efficient. HNO3 sticks quickly to any surface and is thereby either dry deposited or incorporated into aerosols as nitrate (NO3-). In contrast to NOx compounds, NH3 has potentially high impacts on ecosystems near the main agricultural sources of NH3 because of its large ground-level concentrations along with large dry deposition rates. Aerosol phase NH4+ and NO3- contribute significantly to background PM2.5 and PM10 (mass of aerosols with an aerodynamic diameter of less than 2.5 and 10 μm, respectively) with an impact on radiation balance as well as potentially on human health. Little is known quantitatively and qualitatively about organic N in the atmosphere, other than that it contributes a significant fraction of wet-deposited N, and is present in both gaseous and particulate forms. Further studies are needed to characterise the sources, air chemistry and

  15. Circulating factors induce coronary endothelial cell activation following exposure to inhaled diesel exhaust and nitrogen dioxide in humans: Evidence from a novel translational in vitro model**

    Science.gov (United States)

    The vascular toxicity of inhaled agents may be caused by soluble factors that are released into the systemic circulation. To confirm this in a straightforward manner, we obtained plasma from healthy human volunteers before and after exposure to diesel exhaust (DE) and nitrogen di...

  16. Technologies for the treatment of the sulfur dioxide and nitrogen oxides generated by the combustion in open chamber; Tecnologias para el tratamiento de dioxido de azufre y oxidos de nitrogeno generados por la combustion en camara abierta

    Energy Technology Data Exchange (ETDEWEB)

    Salazar Villalpando, Maria Dolores [Instituto Mexicano del Petroleo, Mexico, D. F. (Mexico)

    1992-12-31

    In general terms, there are only three ways of avoiding the sulfur dioxide and the nitrogen oxides, generated by the combustion in open chamber, from contaminating the air; the first one is utilizing low sulfur and nitrogen content fuels, the second one is by controlling the parameters that affect the combustion and the third one to treat and/or clean the gases before exhausting them to the air. In this document, some of the treatments for diminishing the pollutant emissions generated by the combustion in open chamber, are presented. [Espanol] En terminos generales, solo existen 3 maneras de evitar que el dioxido de azufre y oxidos de nitrogeno generados por la combustion en camara abierta sigan contaminando el aire, la primera es utilizar un combustible de bajo contenido de azufre y nitrogeno, la segunda es controlar los parametros que afectan la combustion, y la tercera es tratar y/o limpiar los gases antes de emitirlos a la atmosfera. En este documento se presentan algunos tratamientos para disminuir las emisiones de contaminantes generados por la combustion en camara abierta.

  17. Carbon monoxide kinetics following simulated cigarette smoking

    Energy Technology Data Exchange (ETDEWEB)

    Karnik, A.S. (Wayne State Univ., Detroit, MI); Coin, E.J.

    1980-05-01

    Carbon monoxide kinetics were measured in the blood (% carboxyhemoglobin) and alveolar phase (ppM carbon monoxide) after simulated cigarette smoking. Cigarette smoking was siumlated using the same amount of carbon monoxide that 2R1F cigarettes manufactured by the Tobacco Research Institute would contain. Ten boluses of air containing carbon monoxide equivalent to smoking one cigarette were inhaled by six healthy nonsmoker volunteers. Carbon monoxide in the air phase was measured by an Ecolyzer and carboxyhemoglobin was measured by a CO-Oximeter. The mean rise in alveolar carbon monoxide immediately and 20 min after inhaling the last bolus was 3.3 and 3.1 ppM, respectively (p<.005). The mean rise in carboxyhemoglobin immediately and 20 min after inhalation of the last bolus was 0.8 and 0.5% respectively (P<.005). The changes in carboxyhemoglobin were found to be similar to changes that occur when one cigarette is actually smoked.

  18. Anaesthetic properties of carbon monoxide and other gases in relation to plants, insects, and centipedes

    Energy Technology Data Exchange (ETDEWEB)

    Zimmerman, P.W.

    1935-01-01

    The anaesthetic effect of carbon monoxide, carbon dioxide, propylene, butylene, ethylene, and acetylene, when mixed with oxygen, was tested on ten different species of insects and centipedes. The lowest concentrations found to cause anaesthesia are given in per cent by volume as follows: propylene, for centipede, 30; katydid, 75; rose chafer, 60. Carbon monoxide, for centipede, 81.5; katydid, 89, rose chafer, 85. Butylene, for centipede, 5; katydid, 10; rose chafer, 40. Ethylene or acetylene, for centipede, katydid, and rose chafer, 100. Carbon dioxide, for rose chafer, 30. Ethylene was the most effective plant anaesthetic, 0.0005 per cent stopping growth movements of tomato and sunflower plants as shown by motion pictures; 0.001 per cent stopped elongation of sweet pea seedlings, while 0.00001 per cent retarded elongation nearly 50 per cent. The degree of retardation in growth from ethylene gas varied with the concentration and the plant species. Acetylene and propylene were about equally effective as plant anaesthetics. Both were approximately 10 times as effective as carbon monoxide. Mimosa pudica lost its capacity to respond to external stimuli while being exposed to 0.25 per cent of carbon monoxide, but became normal again upon being removed from the gas. 3 references, 4 tables.

  19. Clinical observation on carbon dioxide fractional laser combined with liquid nitrogen cryotherapy for flat warts%点阵二氧化碳激光联合液氮冷冻治疗扁平疣的临床观察

    Institute of Scientific and Technical Information of China (English)

    缪泽群; 郑楷平; 肖桂凤; 宋韬

    2014-01-01

    目的 评价点阵二氧化碳激光联合液氮冷冻治疗扁平疣的临床疗效和安全性.方法 将83例扁平疣患者按治疗方法分为两组,观察组42例予点阵二氧化碳激光联合液氮冷冻治疗,对照组41例予液氮冷冻治疗,均10d为1个疗程,共治疗2个疗程.比较两组疗效、复发情况及不良反应.结果 观察组第1和2个疗程后痊愈率明显高于对照组[73.81%(31/42)比46.34%(19/41)和97.62%(41/42)比75.61%(31/41)],观察组复发率和不良反应发生率明显低于对照组[2.44%(1/41)比19.35%(6/31)和9.52%(4/42)比31.71%(13/41)],差异均有统计学意义(P< 0.05或< 0.01).结论 点阵二氧化碳激光联合液氮冷冻治疗扁平疣可明显提高痊愈率,降低复发率,而且安全.%Objective To evaluate the clinical efficacy and safety about carbon dioxide fractional laser combined with liquid nitrogen cryotherapy for flat warts.Methods Eighty-three patients with flat warts were divided into 2 groups according to the treatment method,42 patients in treatment group were treated by carbon dioxide fractional laser combined with liquid nitrogen cryotherapy,41 patients in control group were treated by liquid nitrogen cryotherapy alone.As a period for 10 days,2 groups were given 2 periods of treatment.The therapeutic effect,recurrence rate and adverse reaction were compared between 2 groups.Results The cure rates of 1-period and 2-period in treatment group were significantly higher than those in control group [73.81%(31/42) vs.46.34%(19/41) and 97.62%(41/42) vs.75.61%(31/41)],the recurrence rate and incidence of adverse reaction in treatment group were significantly lower than those in control group [2.44%(1/41) vs.19.35%(6/31) and 9.52%(4/42) vs.31.71%(13/41)],there were statistical differences (P < 0.05 or < 0.01).Conclusion Carbon dioxide fractional laser combined with liquid nitrogen cryotherapy for fiat warts is a safe and effective treatment with low

  20. Method for carbon dioxide splitting

    Energy Technology Data Exchange (ETDEWEB)

    Miller, James E.; Diver, Jr., Richard B.; Siegel, Nathan P.

    2017-02-28

    A method for splitting carbon dioxide via a two-step metal oxide thermochemical cycle by heating a metal oxide compound selected from an iron oxide material of the general formula A.sub.xFe.sub.3-xO.sub.4, where 0.ltoreq.x.ltoreq.1 and A is a metal selected from Mg, Cu, Zn, Ni, Co, and Mn, or a ceria oxide compound of the general formula M.sub.aCe.sub.bO.sub.c, where 0dioxide, and heating to a temperature less than approximately 1400 C, thereby producing carbon monoxide gas and the original metal oxide compound.

  1. Compact Reconnaissance Imaging Spectrometer Observations of Water Vapor and Carbon Monoxide

    Science.gov (United States)

    Smith, Michael D.; Wolff, Michael J.; Clancy, R. Todd; Murchie, Scott L.

    2009-01-01

    The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) onboard the Mars Reconnaissance Orbiter (MRO) spacecraft began taking observations in September 2006 and has now collected more than a full Martian year of data. Retrievals performed using the near-infrared spectra obtained by CRISM are used to characterize the seasonal and spatial variation of the column abundance of water vapor and the column-averaged mixing ratio of carbon monoxide. CRISM retrievals show nominal behavior in water vapor during northern hemisphere spring and summer with maximum abundance reaching 50 precipitable micrometers. Water vapor abundance during the southern hemisphere spring and summer appears significantly reduced compared to observations by other instruments taken during previous years. The CRISM retrievals show the seasonally and globally averaged carbon monoxide mixing ratio to be 700 ppm, but with strong seasonal variations at high latitudes. The summertime near-polar carbon monoxide mixing ratio falls to 200 ppm in the south and 400 ppm in the north as carbon dioxide sublimates from the seasonal polar ice caps and dilutes noncondensable species including carbon monoxide. At low latitudes, the carbon monoxide mixing ratio varies in response to the mean seasonal cycle of surface pressure.

  2. One-pot photoassisted synthesis, in situ photocatalytic testing for hydrogen generation and the mechanism of binary nitrogen and copper promoted titanium dioxide.

    Science.gov (United States)

    Taylor, Sean; Mehta, Mihir; Barbash, Dmitri; Samokhvalov, Alexander

    2017-06-14

    For the sustainable production of hydrogen by photocatalysis, the use of renewable resources such as water, organic compounds from plant biomass and earth abundant metal promoters is desired. We herein describe the previously not reported "one-pot" photoassisted synthesis of a binary metal-nitrogen promoted Cu(0)-N-TiO2 photocatalyst from a N-TiO2 precursor by photodeposition of copper directly in the photocatalytic suspension. The N-TiO2 contains nanocrystalline anatase as found by XRD and Raman spectroscopy. X-ray Photoelectron Spectroscopy (XPS) and Electron Spin Resonance (ESR) spectroscopy indicate that a nitrogen promoter is present as a substitutional site. The scheme of relaxation of a photoexcited charge through a substitutional nitrogen induced midgap states in N-TiO2 is proposed. The binary promoted Cu(0)-N-TiO2 photocatalyst prepared from N-TiO2 by "one-pot" photodeposition of copper in the suspension showed a high activity in the in situ hydrogen generation under near-UV/visible light with glycerol in water, up to 675 μmol g(-1) h(-1). The "one-pot" photoassisted synthesis and mechanism of operation of the Cu(0)-N-TiO2 photocatalyst are studied by the complementary in situ spectroscopic methods.

  3. Range Measurements of keV Hydrogen Ions in Solid Oxygen and Carbon Monoxide

    DEFF Research Database (Denmark)

    Schou, Jørgen; Sørensen, H.; Andersen, H.H.

    1984-01-01

    Ranges of 1.3–3.5 keV/atom hydrogen and deuterium molecular ions have been measured by a thin-film reflection method. The technique, used here for range measurements in solid oxygen and carbon monoxide targets, is identical to the one used previously for range measurements in hydrogen and nitrogen....... The main aim was to look for phase-effects, i.e. gas-solid differences in the stopping processes. While measured ranges in solid oxygen were in agreement with known gas data, the ranges in solid carbon monoxide were up to 50% larger than those calculated from gas-stopping data. The latter result agrees...

  4. Cobalt carbonyl catalyzed olefin hydroformylation in supercritical carbon dioxide

    Science.gov (United States)

    Rathke, Jerome W.; Klingler, Robert J.

    1993-01-01

    A method of olefin hydroformylation is provided wherein an olefin reacts with a carbonyl catalyst and with reaction gases such as hydrogen and carbon monoxide in the presence of a supercritical reaction solvent, such as carbon dioxide. The invention provides higher yields of n-isomer product without the gas-liquid mixing rate limitation seen in conventional Oxo processes using liquid media.

  5. Temperature-dependent association between mortality rate and carbon monoxide level in a subtropical city: Kaohsiung, Taiwan.

    Science.gov (United States)

    Lin, Chih-Ming; Liao, Chen-Mao

    2009-06-01

    The objective of this study was to explore the combined effect of temperature and air pollutant levels on daily non-accidental deaths and cardiovascular causes of mortality. In this study, associations were assessed by means of time-series analyses over the period 1995-1999 for Kaohsiung, Taiwan's largest industrial city, which has a subtropical climate. Ambient exposures to various air pollutants, including carbon monoxide (CO), sulfur dioxide (SO(2)), ozone (O(3)), nitrogen dioxide (NO(2)), and particulate matter (PM(10)), were estimated from the arithmetic means of all daily measurements taken by an air quality monitoring station nearest to the residential district. Generalized additive models with non-parametric spline were used to identify associations between daily mortality and air pollutants as well as the air pollutant-temperature interaction correlation. Our findings indicate that CO is associated with increased risks of non-accidental and cardiovascular mortality. For a 0.2 ppm increase in CO, the increased relative daily risk of non-accidental death is at least 4% on the same day, when the mean temperature is above 24.8 degrees C, while the increased relative risk of mortality due to cardiovascular diseases is 7% two days later at 19.7 degrees C. The study also suggests a statistically significant interaction between CO concentration and daily mean temperature, with non-accidental mortality increasing with a warm outdoor temperature and the effect of CO on cardiovascular mortality being modified by a cold climate. Further reduction of CO pollution is thus deemed crucial for the benefit of public health.

  6. Detection of main indoor VOCs and nitrogen dioxide in winter in Dalian city%大连冬季居室主要挥发有机物及二氧化氮检测

    Institute of Scientific and Technical Information of China (English)

    王亚辰; 邵小翠; 朴丰源; 郭鹏; 横山和仁; 上岛通浩

    2011-01-01

    目的 了解冬季居室空气中主要挥发性有机物(VOCs)和二氧化氮的污染水平及其影响因素.方法 于2009年1月对辽宁省大连市某小区随机选择装修后不同时期的99户居室,测定卧室、厨房及室外空气中主要挥发性有机物和二氧化氮浓度,同时对居民基本情况进行问卷调查.结果 卧室空气中甲醛、苯、甲苯和二甲苯的浓度分别为37.3,6.8,15.5和9.0μg/m3,厨房分别为39.8,12.7,18.8和9.8μg/m3,卧室和厨房空气中甲醛、苯、甲苯和二甲苯的浓度均高于室外浓度(P<0.05);装修时间在1年内的卧室和厨房空气中3种苯类有机化合物的浓度均明显高于装修时间≥1年的卧室和厨房空气浓度;摆放绿色植物的居室中甲醛和二氧化氮浓度明显低于未摆放绿色植物的居室(P<0.05).结论 冬季装修居室内存在主要VOCs污染,其浓度随装修后时间的增加而降低,尤其3种苯类有机化合物的浓度下降较快.室内绿色植物对室内污染物有一定的吸附和消除作用.%Objective To determine concentrations of main indoor volatile organic compounds(VOCs) and nitrogen dioxide pollution level and their influencing factors. Methods According to different time after room decoration,99 households were randomly selected in a residential district of Dalian. Air was sampled in bedroom, kitchen and outdoor and a questionnaire survey was conducted among the residents of the district. Nitrogen dioxide and VOCs in the air samples were determined. Results In the bedrooms, the concentrations of formaldehyde, benzene, toluene, and xylene were 37.3,6. 8, 15.5, and 9.0 ftg/m3 and those of in the kitchen were 39. 8,12.7,18. 8,and 9. 8 (jig/m3 .respectively. The indoor concentrations of VOCs were higher than those of outdoor( P < 0.05). Within one year after decoration, the concentration of benzene, toluene,and xylene in bedroom and kitchen were significantly higher than those more than one year after

  7. Carbon monoxide conversion by anaerobic bioreactor sludges

    NARCIS (Netherlands)

    Sipma, J.; Stams, A.J.M.; Lens, P.N.L.; Lettinga, G.

    2003-01-01

    Seven different anaerobic sludges from wastewater treatment reactors were screened for their ability to convert carbon monoxide (CO) at 30 and 55degreesC
    Seven different anaerobic sludges from wastewater treatment reactors were screened for their ability to convert carbon monoxide (CO) at 30 and

  8. Carbon dioxide conversion by means of coplanar dielectric barrier discharges

    Science.gov (United States)

    Schiorlin, Milko; Klink, Rouven; Brandenburg, Ronny

    2016-08-01

    To face the worldwide problem of anthropogenic carbon dioxide (CO2) emission new techniques have to be developed. One approach for carbon capture utilization (CCU) is the conversion of CO2 to more valuable chemicals, e.g., carbon monoxide (CO) by means of non-thermal plasma generated at ambient conditions and supplied by excess energy from renewable sources. This paper reports about the effect of the admixture of inert gases, namely nitrogen or argon to CO2 in a coplanar dielectric barrier discharge (DBD). Systematic experiments were conducted to investigate the effects of applied voltage, frequency, flowrate and CO2 concentration in the influent. The composition of products, energy efficiency and yield were determined. Within the investigated parameter ranges, the maximum conversion of CO2 to CO efficiency of 1% was achieved when the specific input energy was 190 J L-1, whereas the maximum CO yield of 0.7% was achieved when the specific input energy was 210 J L-1. In conclusion, the energy efficiency can be significantly increased by operating the plasma in a diluted CO2 gas. Contribution to the topical issue "6th Central European Symposium on Plasma Chemistry (CESPC-6)", edited by Nicolas Gherardi, Ester Marotta and Cristina Paradisi

  9. Nitrogen dioxide-dependent oxidation of uric acid in the human oral cavity under acidic conditions: implications for its occurrence in acidic dental plaque.

    Science.gov (United States)

    Takahama, Umeo; Hirota, Sachiko

    2010-06-21

    The pH in dental plaque falls to below 5 after the ingestion of foods, and it may remain low if acid-tolerant bacteria grow in the plaque. Certain nitrate-reducing bacteria in the oral cavity can proliferate in dental plaque at low pH, and nitrite is detected in such plaque. In acidic dental plaque, NO(2) can be produced by self-decomposition of nitrous acid and also by peroxidase-catalyzed oxidation of nitrite, and it may oxidize uric acid, a major antioxidant in the oral cavity. Under experimental conditions that simulate oral cavity, the oxidation of uric acid by nitrite and by nitrite/peroxidase systems was much more rapid at pH 5 than at pH 7, suggesting the more rapid production of NO(2) in dental plaque at lower pH. We propose that if the pH of plaque developed in a dental crevice decreased, NO(2) and other nitrogen oxides produced in the plaque would diffuse into the adjoining gingival tissues. The results of this study seem to contribute to the understanding of the induction of periodontal diseases in the context of nitrite-dependent production of nitrogen oxides in acidic dental plaque.

  10. Material processing with hydrogen and carbon monoxide on Mars

    Science.gov (United States)

    Hepp, Aloysius F.; Landis, Geoffrey A.; Linne, Diane L.

    1991-01-01

    Several novel proposals are examined for propellant production from carbon dioxide and monoxide and hydrogen. Potential uses were also examined of CO as a fuel or as a reducing agent in metal oxide processing as obtained or further reduced to carbon. Hydrogen can be reacted with CO to produce a wide variety of hydrocarbons, alcohols, and other organic compounds. Methanol, produced by Fischer-Tropsch chemistry may be useful as a fuel; it is easy to store and handle because it is a liquid at Mars temperatures. The reduction of CO2 to hydrocarbons such as methane or acetylene can be accomplished with hydrogen. Carbon monoxide and hydrogen require cryogenic temperatures for storage as liquids. Noncryogenic storage of hydrogen may be accomplished using hydrocarbons, inorganic hydrides, or metal hydrides. Noncryogenic storage of CO may be accomplished in the form of iron carbonyl (FE(CO)5) or other metal carbonyls. Low hydrogen content fuels such as acetylene (C2H2) may be effective propellants with low requirements for earth derived resources. The impact on manned Mars missions of alternative propellant production and utilization is discussed.

  11. Space-based observation of volcanic iodine monoxide

    Science.gov (United States)

    Schönhardt, Anja; Richter, Andreas; Theys, Nicolas; Burrows, John P.

    2017-04-01

    Volcanic eruptions inject substantial amounts of halogens into the atmosphere. Chlorine and bromine oxides have frequently been observed in volcanic plumes from different instrumental platforms such as from ground, aircraft and satellites. The present study is the first observational evidence that iodine oxides are also emitted into the atmosphere during volcanic eruptions. Large column amounts of iodine monoxide, IO, are observed in satellite measurements following the major eruption of the Kasatochi volcano, Alaska, in 2008. The IO signal is detected in measurements made both by SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric CHartographY) on ENVISAT (Environmental Satellite) and GOME-2 (Global Ozone Monitoring Experiment-2) on MetOp-A (Meteorological Operational Satellite A). Following the eruption on 7 August 2008, strongly elevated levels of IO slant columns of more than 4 × 1013 molec cm-2 are retrieved along the volcanic plume trajectories for several days. The retrieved IO columns from the different instruments are consistent, and the spatial distribution of the IO plume is similar to that of bromine monoxide, BrO. Details in the spatial distribution, however, differ between IO, BrO and sulfur dioxide, SO2. The column amounts of IO are approximately 1 order of magnitude smaller than those of BrO. Using the GOME-2A observations, the total mass of IO in the volcanic plume injected into the atmosphere from the eruption of Kasatochi on 7 August 2008, is determined to be on the order of 10 Mg.

  12. The Carbon Monoxide Tape Recorder

    Science.gov (United States)

    Schoeberl, M. R.; Duncan, B. N.; Douglass, A. R.; Waters, J.; Livesey, N.; Read, W.; Filipiak, M.

    2006-01-01

    Using Aura MLS data we have identified the stratospheric tape recorder in carbon monoxide (CO). Unlike the water vapor tape recorder, which is controlled by upper troposphere processes, the CO tape recorder is linked to seasonal biomass burning. Since CO has a lifetime of only a few months, the CO tape recorder barely extends above 20 km. The tape head for CO appears to be close to 360K near the same location as the water vapor tape head [Read et al, 20041. Both tape heads are below the equatorial cold point tropopause but above the base of the tropical tropopause layer. The tape recorder signal becomes more distinct from 360K to 380K suggesting that convective detrainment of plays a decreasingly important role with altitude. The Global Modeling Initiative chemical transport model forced by the climatology of biomass burning reproduces the CO tape recorder.

  13. Ozone and nitrogen dioxide gas sensor based on a nanostructured SrTi{sub 0.85}Fe{sub 0.15}O{sub 3} thin film

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Luís F. da, E-mail: lfsilva83@gmail.com [LIEC, Instituto de Química, Universidade Estadual Paulista, P.O. Box 355, 14800-900 Araraquara, SP (Brazil); Aix Marseille Université, CNRS IM2NP (UMR 7334), FS St Jérôme S152, Marseille 13397 (France); Mastelaro, Valmor R.; Catto, Ariadne C.; Escanhoela, Carlos A. [Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense, 400, 13566-590 São Carlos, SP (Brazil); Bernardini, Sandrine [Aix Marseille Université, CNRS IM2NP (UMR 7334), FS St Jérôme S152, Marseille 13397 (France); Zílio, Sérgio C. [Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense, 400, 13566-590 São Carlos, SP (Brazil); Longo, Elson [LIEC, Instituto de Química, Universidade Estadual Paulista, P.O. Box 355, 14800-900 Araraquara, SP (Brazil); Aguir, Khalifa, E-mail: khalifa.aguir@im2np.fr [Aix Marseille Université, CNRS IM2NP (UMR 7334), FS St Jérôme S152, Marseille 13397 (France)

    2015-07-25

    Highlights: • Nanostructured SrTi{sub 1−x}Fe{sub x}O{sub 3} films were deposited by electron beam evaporation. • XANES spectroscopy revealed an increase of crystallization after heat-treatment. • Annealing treatment contributes improving the gas-sensing performance. • The SrTi{sub 1−x}Fe{sub x}O{sub 3} film exhibited a good sensitivity to oxidizing gases. • The results show that SrTi{sub 1−x}Fe{sub x}O{sub 3} can be considered a potential ozone gas sensor. - Abstract: In this manuscript, we report an investigation into the sensitivity of two oxidizing gases (ozone and nitrogen dioxide) for nanocrystalline SrTi{sub 0.85}Fe{sub 0.15}O{sub 3} thin films deposited by the electron beam physical vapor deposition technique. Annealing treatment at 500 °C enhanced the crystallization and surface roughness of the thin film. Electrical measurements revealed that the thin film was sensitive to oxidizing gases, especially to low ozone gas levels, exhibiting a fast response time, a short recovery time as well as good reproducibility and reversibility. These findings demonstrate the great potential of the SrTi{sub 0.85}Fe{sub 0.15}O{sub 3} compound to be applied as a selective ozone gas sensor.

  14. Engineering evidence for carbon monoxide toxicity cases.

    Science.gov (United States)

    Galatsis, Kosmas

    2016-07-01

    Unintentional carbon monoxide poisonings and fatalities lead to many toxicity cases. Given the unusual physical properties of carbon monoxide-in that the gas is odorless and invisible-unorganized and erroneous methods in obtaining engineering evidence as required during the discovery process often occurs. Such evidence gathering spans domains that include building construction, appliance installation, industrial hygiene, mechanical engineering, combustion and physics. In this paper, we attempt to place a systematic framework that is relevant to key aspects in engineering evidence gathering for unintentional carbon monoxide poisoning cases. Such a framework aims to increase awareness of this process and relevant issues to help guide legal counsel and expert witnesses.

  15. Delayed encephalopathy after acute carbon monoxide poisoning

    Directory of Open Access Journals (Sweden)

    Mehmet İbrahim Turan

    2014-03-01

    Full Text Available Carbon monoxide poisoning is a major cause of death following attempted suicide and accidental exposures. Although clinical presentation depends on the duration and the intensity of exposure, the assessment of the severity of intoxication is difficult. A small percentage of patients who show complete initial recovery may develop delayed neurological deficits. Delayed encephalopathy after acute carbon monoxide poisoning is a rare and poor prognosis neurologic disorders and there is no specific treatment. We present a case with early onset of delayed encephalopathy after acute carbon monoxide poisoning with typical cranial imaging findings in a child with atypical history and clinical presentation.

  16. Interactive effects of carbon dioxide and nitrogen supply on above-and belowground chemical composition of loblolly pine (Pinus taeda L.) seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Gebauer, R.L.E.; Reynolds, J.F.; Strain, B.R. [Duke Univ., Durham, NC (United States)

    1995-09-01

    Changes in the whole plant carbon/nitrogen balance of loblolly pine grown at ambient and elevated CO{sub 2}-levels (35 and 70 Pa) and four N levels (0.5, 1.5, 3.5 and 6.5 mM NH{sub 4}NO{sub 3}) were determined by measuring concentrations of total proteins, free amino acids, carbohydrates, and phenolic compounds. Free amino acids and protein concentrations increased with N availability in needles and lateral roots, but were unchanged in stems and tap roots. Under elevated CO{sub 2} starch content was increased in needles but not in roots or stems. Changes in phenolic content in response to elevated CO{sub 2} or N availability generally followed the pattern of soluble sugar concentrations. Phenolic content was in primary needles>lateral roots>tap roots>fascicular needles>stems and decreased with increasing N availability (at>1.5 mM NH{sub 4}NO{sub 3}). Phenolic content was significantly increased at 70 Pa CO{sub 2} only in needles and stems, but not in roots.

  17. Glutamine Synthetases GLN1;2 and GLN2 in Relation to Arabidopsis Growth Response to Elevated Atmospheric Carbon Dioxide and Varying Nitrogen Forms

    DEFF Research Database (Denmark)

    Vurrakula, Swathi

    cues and adjusting it to the plant internal status. The two major types of GS include cytosolic GS1 (five isoforms in Arabidopsis, GLN1;1 to GLN1;5) and a single chloroplastic GS2. GS draws its substrates from carbon skeletons to synthesize amino acids. Thus, carbon and nitrogen metabolisms are closely....... Plants grown under elevated CO2 absorbed ammonia from the atmosphere, except with a high ammonium supply. GLN1;2 had a non-redundant role in determining vegetative growth and ammonium tolerance in response to elevated CO2. Under elevated CO2, GLN1;2 was compensable by GLN2 in assimilating nitrate...... but not ammonium. Reduced GS1 activity correlated with increased ammonia emissions from leaf surface, markedly so with an increased supply of both ammonium and CO2. GLN1;2 was also found to play a vital role in assimilating high levels of nitrate. Under current CO2 levels (400ppm) GLN2 had a non-redundant role...

  18. Effect of nitrogen doping on oxygen vacancies of titanium dioxide supported vanadium pentoxide for ammonia-SCR reaction at low temperature.

    Science.gov (United States)

    Li, Hongyu; Zhang, Shule; Zhong, Qin

    2013-07-15

    A V2O5/N-doped TiO2 catalyst has been developed by partly substituting the lattice oxygen of TiO2 support with nitrogen, which showed a remarkable increase in activity for the reduction of NO with NH3 at low temperature. The catalyst was characterized by Brunauer-Emmett-Teller (BET), transmission electron microscope (TEM), photoluminescence (PL), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR). The results demonstrated that N doping cannot noticeably change the microscopic features but dramatically enhanced the formation of surface oxygen vacancies, which can play a vital role in the formation of superoxide ions to improve the SCR activity. The catalyst with [N]/[Ti]=1.0×10(-2) showed the highest NO removal efficiency in the SCR reaction at low temperature. Furthermore, the V1TiN1.0 catalyst showed better resistance to SO2 and H2O during the SCR of NO.

  19. Carbon dioxide elimination and regeneration of resources in a microwave plasma torch.

    Science.gov (United States)

    Uhm, Han S; Kwak, Hyoung S; Hong, Yong C

    2016-04-01

    Carbon dioxide gas as a working gas produces a stable plasma-torch by making use of 2.45 GHz microwaves. The temperature of the torch flame is measured by making use of optical spectroscopy and a thermocouple device. Two distinctive regions are exhibited, a bright, whitish region of a high-temperature zone and a bluish, dimmer region of a relatively low-temperature zone. The bright, whitish region is a typical torch based on plasma species where an analytical investigation indicates dissociation of a substantial fraction of carbon dioxide molecules, forming carbon monoxides and oxygen atoms. The emission profiles of the oxygen atoms and the carbon monoxide molecules confirm the theoretical predictions of carbon dioxide disintegration in the torch. Various hydrocarbon materials may be introduced into the carbon dioxide torch, regenerating new resources and reducing carbon dioxide concentration in the torch. As an example, coal powders in the carbon dioxide torch are converted into carbon monoxide according to the reaction of CO2 + C → 2CO, reducing a substantial amount of carbon dioxide concentration in the torch. In this regards, the microwave plasma torch may be one of the best ways of converting the carbon dioxides into useful new materials.

  20. Visual and reversible carbon dioxide sensing enabled by doctor blade coated macroporous photonic crystals.

    Science.gov (United States)

    Lin, Yi-Han; Suen, Shing-Yi; Yang, Hongta

    2017-11-15

    With significant impacts of carbon dioxide on global climate change, carbon dioxide sensing is of great importance. However, most of the existing sensing technologies are prone to interferences from carbon monoxide, or suffer from the use of sophisticated instruments. This research reports the development of reproducible carbon dioxide sensor using roll-to-roll compatible doctor blade coated three-dimensional macroporous photonic crystals. The pores are functionalized with amine groups to allow the reaction with carbon dioxide in the presence of humidity. The adsorption of carbon dioxide leads to red-shift and amplitude reduction of the optical stop bands, resulting in carbon dioxide detection with visible readout. The dependences of the diffraction wavelength on carbon dioxide partial pressure for various amine-functionalized photonic crystals and different humidities in the environment are systematically investigated. In addition, the reproducibility of carbon dioxide sensing has also been demonstrated in this research. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Heterogeneous-phase reactions of nitrogen dioxide with vermiculite-supported magnesium oxide (as applied to the control of jet engine test cell emissions). Doctoral thesis

    Energy Technology Data Exchange (ETDEWEB)

    Kimm, L.T.

    1995-11-01

    Controlling nitrogen oxides (NOx) from a non-steady-state stationary source like a jet engine test cell (JETC) requires a method that is effective over a wide range of conditions. A heterogeneous, porous, high surface area sorbent material comprised of magnesium oxide powder attached to a vermiculite substrate has been commercially developed for this purpose. Data from extensive laboratory testing of this material in a packed-bed flow system are presented. NO2 removal efficiencies, kinetics, and proposed NO2 removal mechanisms over a range of representative JETC exhaust gas characteristics are described. Exhaust gas variables evaluated included: NO2 concentration, temperature, flow rate (retention time), oxygen content, and moisture content. Availability of water and oxygen were found to be important variables. It is probable that water is necessary for the conversion of MgO to Mg(OH)2, which is a more reactive compound having thermal stability over the range of temperatures evaluated. Gaseous oxygen serves to oxidize NO to NO2, the latter being more readily removed from the gas stream. The presence of oxygen also serves to offset thermal decomposition of NO2 or surface nitrite/nitrate. Effective `lifetime` and regenerability of the exposed sorbent material were also evaluated. NO2 removal efficiencies were found to greatly exceed those for NO, with a maximum value greater than 90 percent. The effective conversion of NO to NO2 is a crucial requirement for removal of the former. The reaction between NO2 and MgO-vermiculite is first-order with respect to NO2.

  2. 76 FR 52283 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Control of Nitrogen...

    Science.gov (United States)

    2011-08-22

    ...; Control of Nitrogen Oxides Emissions From Glass Melting Furnaces AGENCY: Environmental Protection Agency... submitted by the Commonwealth of Pennsylvania. The SIP revisions pertain to the control of nitrogen oxide..., Nitrogen dioxide, Ozone, Particulate matter, Reporting and recordkeeping requirements. Dated: August...

  3. 76 FR 34021 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Control of Nitrogen...

    Science.gov (United States)

    2011-06-10

    ...; Control of Nitrogen Oxides Emissions From Glass Melting Furnaces AGENCY: Environmental Protection Agency...) revision submitted by the Commonwealth of Pennsylvania. This revision pertains to the control of nitrogen... in 40 CFR Part 52 Environmental protection, Air pollution control, Nitrogen dioxide,...

  4. 76 FR 42558 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Control of Nitrogen...

    Science.gov (United States)

    2011-07-19

    ...; Control of Nitrogen Oxides Emissions from Portland Cement Kilns AGENCY: Environmental Protection Agency... submitted by the Commonwealth of Pennsylvania. The SIP revisions pertain to the control of nitrogen oxides..., Incorporation by reference, Nitrogen dioxide, Ozone, Particulate matter, Reporting and...

  5. Carbon Monoxide Silicate Reduction System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Carbon Monoxide Silicate Reduction System (COSRS) is a novel technology for producing large quantities of oxygen on the Moon. Oxygen yields of 15 kilograms per...

  6. Protect Yourself from Carbon Monoxide Poisoning

    Centers for Disease Control (CDC) Podcasts

    2007-11-20

    Learn about carbon monoxide - a colorless, odorless gas - and how to protect yourself and your family.  Created: 11/20/2007 by CDC National Center for Environmental Health.   Date Released: 12/4/2007.

  7. Chemical production from waste carbon monoxide: its potential for energy conservation

    Energy Technology Data Exchange (ETDEWEB)

    Rohrmann, C.A.; Schiefelbein, G.F.; Molton, P.M.; Li, C.T.; Elliott, D.C.; Baker, E.G.

    1977-11-01

    Results of a study of the potential for energy conservation by producing chemicals from by-product or waste carbon monoxide (CO) from industrial sources are summarized. Extensive compilations of both industrial sources and uses for carbon monoxide were developed and included. Reviews of carbon monoxide purification and concentration technology and preliminary economic evaluations of carbon monoxide concentration, pipeline transportation and utilization of CO in the synthesis of ammonia and methanol are included. Preliminary technical and economic feasibility studies were made of producing ammonia and methanol from the by-product CO produced by a typical elemental phosphorus plant. Methanol synthesis appears to be more attractive than ammonia synthesis when using CO feedstock because of reduced water gas shift and carbon dioxide removal requirements. The economic studies indicate that methanol synthesis from CO appears to be competitive with conventional technology when the price of natural gas exceeds $0.82/million Btu, while ammonia synthesis from CO is probably not competitive until the price of natural gas exceeds $1.90/million Btu. It is concluded that there appears to be considerable potential for energy conservation in the chemical industry, by collecting CO rather than flaring it, and using it to make major chemicals such as ammonia and methanol.

  8. MODELLING OF CARBON MONOXIDE AIR POLLUTION IN LARG CITIES BY EVALUETION OF SPECTRAL LANDSAT8 IMAGES

    Directory of Open Access Journals (Sweden)

    M. Hamzelo

    2015-12-01

    Full Text Available Air pollution in large cities is one of the major problems that resolve and reduce it need multiple applications and environmental management. Of The main sources of this pollution is industrial activities, urban and transport that enter large amounts of contaminants into the air and reduces its quality. With Variety of pollutants and high volume manufacturing, local distribution of manufacturing centers, Testing and measuring emissions is difficult. Substances such as carbon monoxide, sulfur dioxide, and unburned hydrocarbons and lead compounds are substances that cause air pollution and carbon monoxide is most important. Today, data exchange systems, processing, analysis and modeling is of important pillars of management system and air quality control. In this study, using the spectral signature of carbon monoxide gas as the most efficient gas pollution LANDSAT8 images in order that have better spatial resolution than appropriate spectral bands and weather meters،SAM classification algorithm and Geographic Information System (GIS , spatial distribution of carbon monoxide gas in Tehran over a period of one year from the beginning of 2014 until the beginning of 2015 at 11 map have modeled and then to the model valuation ،created maps were compared with the map provided by the Tehran quality comparison air company. Compare involved plans did with the error matrix and results in 4 types of care; overall, producer, user and kappa coefficient was investigated. Results of average accuracy were about than 80%, which indicates the fit method and data used for modeling.

  9. Modelling of Carbon Monoxide Air Pollution in Larg Cities by Evaluetion of Spectral LANDSAT8 Images

    Science.gov (United States)

    Hamzelo, M.; Gharagozlou, A.; Sadeghian, S.; Baikpour, S. H.; Rajabi, A.

    2015-12-01

    Air pollution in large cities is one of the major problems that resolve and reduce it need multiple applications and environmental management. Of The main sources of this pollution is industrial activities, urban and transport that enter large amounts of contaminants into the air and reduces its quality. With Variety of pollutants and high volume manufacturing, local distribution of manufacturing centers, Testing and measuring emissions is difficult. Substances such as carbon monoxide, sulfur dioxide, and unburned hydrocarbons and lead compounds are substances that cause air pollution and carbon monoxide is most important. Today, data exchange systems, processing, analysis and modeling is of important pillars of management system and air quality control. In this study, using the spectral signature of carbon monoxide gas as the most efficient gas pollution LANDSAT8 images in order that have better spatial resolution than appropriate spectral bands and weather meters،SAM classification algorithm and Geographic Information System (GIS ), spatial distribution of carbon monoxide gas in Tehran over a period of one year from the beginning of 2014 until the beginning of 2015 at 11 map have modeled and then to the model valuation ،created maps were compared with the map provided by the Tehran quality comparison air company. Compare involved plans did with the error matrix and results in 4 types of care; overall, producer, user and kappa coefficient was investigated. Results of average accuracy were about than 80%, which indicates the fit method and data used for modeling.

  10. Integrated electricity and carbon monoxide production

    Energy Technology Data Exchange (ETDEWEB)

    Griffiths, J.

    1994-03-23

    In a process for the production of carbon monoxide and electric power in an IGCC with the removal of sulphur compounds, between the outlet of quenched gas from a partial oxidation unit and a fuel inlet to a combined cycle gas turbine there is a permeable membrane unit to separate a non-permeable stream, which is utilised as a source of carbon monoxide, and a permeate stream, which is used as fuel for the gas turbine of the combined cycle unit. (author)

  11. Hearing Loss due to Carbon Monoxide Poisoning

    Directory of Open Access Journals (Sweden)

    Amir Houshang Mehrparvar

    2013-01-01

    Full Text Available Carbon monoxide poisoning is one of the rare causes of hearing loss which may cause reversible or irreversible, unilateral or bilateral hearing loss after acute or chronic exposure. In this report, we present a case of bilateral sensorineural hearing loss in a secondary smelting workshop worker after an acute exposure to carbon monoxide. This complication was diagnosed by pure-tone audiometry and confirmed by transient evoked otoacoustic emissions. Hearing loss has not improved after 3 months of followup.

  12. Aircraft measurements of bromine monoxide, iodine monoxide, and glyoxal profiles in the tropics: comparison with ship-based and in situ measurements

    Science.gov (United States)

    Volkamer, R.; Baidar, S.; Campos, T. L.; Coburn, S.; DiGangi, J. P.; Dix, B.; Koenig, T. K.; Ortega, I.; Pierce, B. R.; Reeves, M.; Sinreich, R.; Wang, S.; Zondlo, M. A.; Romashkin, P. A.

    2015-01-01

    Tropospheric chemistry of halogens and organic carbon over tropical oceans modifies ozone and atmospheric aerosols, yet atmospheric models remain largely untested for lack of vertically resolved measurements of bromine monoxide (BrO), iodine monoxide (IO), and small oxygenated hydrocarbons like glyoxal (CHOCHO) in the tropical troposphere. BrO, IO, glyoxal, nitrogen dioxide (NO2), water vapor (H2O) and O2-O2 collision complexes (O4) were measured by the CU Airborne Multi AXis Differential Optical Absorption Spectroscopy (CU AMAX-DOAS) instrument, in situ aerosol size distributions by an Ultra High Sensitivity Aerosol Spectrometer (UHSAS), and in situ H2O by Vertical-Cavity Surface-Emitting Laser hygrometer (VCSEL). Data are presented from two research flights (RF12, RF17) aboard the NSF/NCAR GV aircraft over the tropical Eastern Pacific Ocean (tEPO) as part of the "Tropical Ocean tRoposphere Exchange of Reactive halogens and Oxygenated hydrocarbons" (TORERO) project. We assess the accuracy of O4 slant column density (SCD) measurements in the presence and absence of aerosols, and find O4-inferred aerosol extinction profiles at 477 nm agree within 5% with Mie calculations of extinction profiles constrained by UHSAS. CU AMAX-DOAS provides a flexible choice of geometry which we exploit to minimize the SCD in the reference spectrum (SCDREF, maximize signal-to-noise), and to test the robustness of BrO, IO, and glyoxal differential SCDs. The RF12 case study was conducted in pristine marine and free tropospheric air. The RF17 case study was conducted above the NOAA RV Ka'imimoana (TORERO cruise, KA-12-01), and provides independent validation data from ship-based in situ Cavity Enhanced- and MAX-DOAS. Inside the marine boundary layer (MBL) no BrO was detected (smaller than 0.5 pptv), and 0.2-0.55 pptv IO and 32-36 pptv glyoxal were observed. The near surface concentrations agree within 20% (IO) and 10% (glyoxal) between ship and aircraft. The BrO concentration strongly

  13. Aircraft measurements of bromine monoxide, iodine monoxide, and glyoxal profiles in the tropics: comparison with ship-based and in situ measurements

    Directory of Open Access Journals (Sweden)

    R. Volkamer

    2015-01-01

    Full Text Available Tropospheric chemistry of halogens and organic carbon over tropical oceans modifies ozone and atmospheric aerosols, yet atmospheric models remain largely untested for lack of vertically resolved measurements of bromine monoxide (BrO, iodine monoxide (IO, and small oxygenated hydrocarbons like glyoxal (CHOCHO in the tropical troposphere. BrO, IO, glyoxal, nitrogen dioxide (NO2, water vapor (H2O and O2-O2 collision complexes (O4 were measured by the CU Airborne Multi AXis Differential Optical Absorption Spectroscopy (CU AMAX-DOAS instrument, in situ aerosol size distributions by an Ultra High Sensitivity Aerosol Spectrometer (UHSAS, and in situ H2O by Vertical-Cavity Surface-Emitting Laser hygrometer (VCSEL. Data are presented from two research flights (RF12, RF17 aboard the NSF/NCAR GV aircraft over the tropical Eastern Pacific Ocean (tEPO as part of the "Tropical Ocean tRoposphere Exchange of Reactive halogens and Oxygenated hydrocarbons" (TORERO project. We assess the accuracy of O4 slant column density (SCD measurements in the presence and absence of aerosols, and find O4-inferred aerosol extinction profiles at 477 nm agree within 5% with Mie calculations of extinction profiles constrained by UHSAS. CU AMAX-DOAS provides a flexible choice of geometry which we exploit to minimize the SCD in the reference spectrum (SCDREF, maximize signal-to-noise, and to test the robustness of BrO, IO, and glyoxal differential SCDs. The RF12 case study was conducted in pristine marine and free tropospheric air. The RF17 case study was conducted above the NOAA RV Ka'imimoana (TORERO cruise, KA-12-01, and provides independent validation data from ship-based in situ Cavity Enhanced- and MAX-DOAS. Inside the marine boundary layer (MBL no BrO was detected (smaller than 0.5 pptv, and 0.2–0.55 pptv IO and 32–36 pptv glyoxal were observed. The near surface concentrations agree within 20% (IO and 10% (glyoxal between ship and aircraft. The BrO concentration strongly

  14. The Formation of Ethane from Carbon Dioxide under Cold Plasma

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Pulsed-corona plasma has been used as a new method for ethane dehydrogenation at low temperature and normal pressure using carbon dioxide as an oxidant in this paper. The effect of carbon dioxide content in the feed, power input, and flow rate of the reactants on the ethane dehydrogenation has been investigated. The experimental results show that the conversion of ethane increases with the increase in the amount of carbon dioxide in the feed. The yield of ethylene and acetylene decreases with the increase in the yield of carbon monoxide, indicating that the increased carbon dioxide leads to the part of ethylene and acetylene being oxidized to carbon monoxide. Power input is primarily an electrical parameter in pulsed-corona plasma, which plays an important role in reactant conversion and product formation. When the power input reaches 16 W, ethane conversion is 41.0% and carbon dioxide conversion is 26.3%. The total yield of ethylene and acetylene is 15.6%. The reduced flow rate of feed improves the conversion of ethane,carbon dioxide and the yield of acetylene, and induces carbon deposit as well.

  15. The Mechanism on Biomass Reduction of Low-Grade Manganese Dioxide Ore

    Science.gov (United States)

    Zhang, Honglei; Zhu, Guocai; Yan, Hong; Li, Tiancheng; Zhao, Yuna

    2013-08-01

    The mechanism on biomass reduction of low-grade manganese dioxide ore was studied by investigating influence factors on manganese recovery degree, such as the reaction temperature, time, biomass/ore ratio, compositions of biomass, nitrogen flow rate, and particle size of raw materials, and it was further identified through analysis of gas composition in the outlet gas, X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) for the reduced sample. The results show that the reduction process involved mainly two steps: (1) The biomass was first pyrolyzed to release reductive volatiles and (2) manganese oxide ore was reacted with the reductive volatiles. By an analysis of gas composition in the outlet gas, it was also found that the ratio of biomass/ore had an important effect on the reduction mechanism. With a low biomass/ore ratio of 0.5:10, the reducing reaction of the reductive volatiles with manganese dioxide ore proceeded mainly in two stages: (1) The condensable volatiles (tar) released from biomass pyrolysis reacted with manganese oxide ore to produce reductive noncondensable gases such as hydrogen, carbon monoxide, and some light hydrocarbons; and (2) the small molecule gases further participated in the reduction. XRD pattern analysis on the reduced manganese dioxide ore revealed that the process of biomass reduction of manganese ore underwent in phases (MnO2 → Mn3O4 → MnO). The kinetics study showed the reduction process was controlled by a gas-solid reaction between biomass volatiles and manganese oxide ore with activation energy E of 53.64 kJ mol-1 and frequency factor A of 5.45 × 103 minutes-1.

  16. Carbon dioxide stripping in aquaculture. part 1: terminology and reporting

    Science.gov (United States)

    Colt, John; Watten, Barnaby; Pfeiffer, Tim

    2012-01-01

    The removal of carbon dioxide gas in aquacultural systems is much more complex than for oxygen or nitrogen gas because of liquid reactions of carbon dioxide and their kinetics. Almost all published carbon dioxide removal information for aquaculture is based on the apparent removal value after the CO2(aq) + HOH ⇔ H2CO3 reaction has reached equilibrium. The true carbon dioxide removal is larger than the apparent value, especially for high alkalinities and seawater. For low alkalinity freshwaters (carbon dioxide removal.

  17. Evaluation of a Colorimetric Personal Dosimeter for Nitrogen Oxide.

    Science.gov (United States)

    Diamond, Philip

    A personal colorimetric dosimeter for nitrogen dioxide was developed. Tests were performed to determine the response of these strips to various concentrations of NO2. The dosimeter strips were satisfactory for approximate determinations of total exposure (concentration + time) of nitrogen dioxide. The total exposure was calculated in terms of time…

  18. 40 CFR 50.11 - National primary and secondary ambient air quality standards for oxides of nitrogen (with...

    Science.gov (United States)

    2010-07-01

    ... air quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). 50.11 Section... PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS § 50.11 National primary and secondary ambient air quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). (a) The level of...

  19. Effects of chemical modifications of heme on kinetics of carbon monoxide binding to free home

    Energy Technology Data Exchange (ETDEWEB)

    Sono, M.; McCray, J.A.; Asakura, T.

    1977-11-10

    The rates of carbon monoxide recombination to six different kinds of chemically modified heme with various substituents at positions 2 and 4 have been studied in the protein-free state (free heme) by the laser flash photolysis method in a mixture of ethylene glycol and 0.02 N NaOH (80:20, v/v) (80% ethylene glycol). The carbon monoxide combination rate constants to the various free hemes obtained in 80% ethylene glycol at 22/sup 0/ were 1.4, 2.1, 2.1, 3.7, 4.5, and 6.4 x 10/sup 7/ M/sup -1/ s/sup -1/ for 2,4-diformyl-, spirographis (2-formyl-4-vinyl-), isospirographis (2-vinyl-4-formyl-) proto-(2,4-divinyl-), deutero-(2,4-dihydrogen-), and meso-(2,4-diethyl-), hemes, respectively. This order of increase in carbon monoxide combination rate constants for these hemes correlates exactly with decrease in electron attractivity of heme side chains (i.e., increase in pK/sub 3/, basicity of nitrogen base of prophyrin) and is completely opposite to that obtained for carbon monoxide binding to these hemes reconstituted with apomyoglobin. Contrary to the results for myoglobin, the two isomers of monoformyl-monovinylheme exhibited similar optical properties and the same combination rate constant indicating that the differences in the optical and kinetic results observed in myoglobin are due to different interactions of these isomeric hemes with protein.

  20. Pulmonary edema in acute carbon monoxide poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kun Sang; Chang, Kee Hyun; Lee, Myung Uk [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1974-10-15

    Acute carbon monoxide poisoning has frequently occurred in Korean, because of the coal briquette being widely used as fuel in Korean residences. Carbon monoxide poisoning has been extensively studied, but it has been sparsely reported that pulmonary edema may develop in acute CO poisoning. We have noticed nine cases of pulmonary edema in acute CO poisoning last year. Other possible causes of pulmonary edema could be exclude in all cases but one. The purpose of this paper is to describe nine cases of pulmonary edema complicated in acute CO poisoning and discuss the pathogenesis and the prognosis.

  1. Governing processes for reactive nitrogen compounds in the European atmosphere

    Directory of Open Access Journals (Sweden)

    O. Hertel

    2012-12-01

    Full Text Available Reactive nitrogen (Nr compounds have different fates in the atmosphere due to differences in the governing processes of physical transport, deposition and chemical transformation. Nr compounds addressed here include reduced nitrogen (NHx: ammonia (NH3 and its reaction product ammonium (NH4+, oxidized nitrogen (NOy: nitrogen monoxide (NO + nitrogen dioxide (NO2 and their reaction products as well as organic nitrogen compounds (organic N. Pollution abatement strategies need to take into account the differences in the governing processes of these compounds when assessing their impact on ecosystem services, biodiversity, human health and climate. NOx (NO + NO2 emitted from traffic affects human health in urban areas where the presence of buildings increases the residence time in streets. In urban areas this leads to enhanced exposure of the population to NOx concentrations. NOx emissions generally have little impact on nearby ecosystems because of the small dry deposition rates of NOx. These compounds need to be converted into nitric acid (HNO3 before removal through deposition is efficient. HNO3 sticks quickly to any surface and is thereby either dry deposited or incorporated into aerosols as nitrate (NO3. In contrast to NOx compounds, NH3 has potentially high impacts on ecosystems near the main agricultural sources of NH3 because of its large ground-level concentrations along with large dry deposition rates. Aerosol phase NH4+ and NO3 contribute significantly to background PM2.5 and PM10 (mass of aerosols with an aerodynamic diameter of less than 2.5 and 10 μm, respectively with an impact on radiation balance as well as potentially on human

  2. The influence of emission changes on ozone concentrations and nitrogen deposition into the southern North Sea

    Directory of Open Access Journals (Sweden)

    Elke M.I. Meyer

    2011-02-01

    Full Text Available The impact of changes in amount of emission for NOx (Nitrogen monoxide NO + Nitrogen dioxide NO2 and NMVOC (Non Methane Volatile Organic Compounds on concentrations of ozone (O3, NOx, nitric acid (HNO3 and on nitrogen deposition in the area of the southern North Sea are investigated. One reference case for the period 16 June till 20 June, 1998 and six emission scenarios are calculated. Spatial and temporal emission patterns are kept and overall emission factors are used that correspond to years 1998 (reference, 1970 and 2010. Some more artificial emission scenarios are constructed to investigate the effect of a changed ratio of NOx to NMVOC emissions. The meteorology is unchanged for all scenarios. The studies are performed with the meteorology/chemistry model M-SYS (METRAS/MECTM including a simple aerosol chemistry and using a horizontal resolution of 8 km. Changes in emissions of NMVOC and NOx cause nonlinear changes in O3, NOx and HNO3 concentrations. The concentration changes depend on emission changes and on changes in the ratio of NMVOC to NOx emissions. The whole area, over land and water, turns out to be in the NMVOC limited regime. Ozone scenario concentrations linearly depend on the ratio of NMVOC to NOx emissions. NOx concentrations linearly depend on changes in the total emissions of NOx and NMVOC. They are inversely related to changes in the ratio of NMVOC to NOx emissions. HNO3 concentrations mainly depend on the total emission changes with NOx emission changes being of doubled relevance compared to NMVOC emission changes. The same relation is found for nitrogen deposition. Compared to mean ozone concentrations from the reference case, higher (lower NOx emissions reduce (increase ozone concentrations, while HNO3 concentrations are increased (reduced. In contrast, reduced (increased NMVOC emissions reduce (increase both, ozone and HNO3 concentrations and, in addition, the nitrogen deposition.

  3. 40 CFR 60.103 - Standard for carbon monoxide.

    Science.gov (United States)

    2010-07-01

    ... Refineries § 60.103 Standard for carbon monoxide. Each owner or operator of any fluid catalytic cracking unit... regenerator any gases that contain carbon monoxide (CO) in excess of 500 ppm by volume (dry basis)....

  4. [Carbon monoxide metabolism by photosynthetic bacteria]. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    1989-12-31

    Research continued on the metabolism of carbon monoxide by Rhodospirillum rubrum. This report discusses progress on the activity, induction, inhibition, and spectroscopic analysis of the enzyme Carbon Monoxide Dehydrogenase. (CBS)

  5. Carbon Monoxide Hazards from Small Gasoline Powered Engines

    Science.gov (United States)

    ... Topics Publications and Products Programs Contact NIOSH NIOSH CARBON MONOXIDE Recommend on Facebook Tweet Share Compartir On this Page Recommendations NIOSH Publications Worker Notification Program Carbon Monoxide Hazards from Small Gasoline Powered Engines Many ...

  6. Photodissociation of carbon dioxide in the Mars upper atmosphere

    Science.gov (United States)

    Barth, C. A.

    1974-01-01

    Calculation of the intensity of two of the emissions produced during the dissociative excitation of carbon dioxide in the upper atmosphere of Mars by solar ultraviolet radiation. The calculation tangential column emission rates of the atomic oxygen 2972-A line and the carbon monoxide Cameron bands produced by the photodissociative mechanism are found to be factors of 3 and 10, respectively, smaller than the emission rates observed by Mariner ultraviolet spectrometers.

  7. Regeneration of oxygen from carbon dioxide and water.

    Science.gov (United States)

    Weissbart, J.; Smart, W. H.; Wydeven, T.

    1972-01-01

    In a closed ecological system it is necessary to reclaim most of the oxygen required for breathing from respired carbon dioxide and the remainder from waste water. One of the advanced physicochemical systems being developed for generating oxygen in manned spacecraft is the solid electrolyte-electrolysis system. The solid electrolyte system consists of two basic units, an electrolyzer and a carbon monoxide disproportionator. The electrolyzer can reclaim oxygen from both carbon dioxide and water. Electrolyzer preparation and assembly are discussed together with questions of reactor design and electrolyzer performance data.

  8. Regeneration of oxygen from carbon dioxide and water.

    Science.gov (United States)

    Weissbart, J.; Smart, W. H.; Wydeven, T.

    1972-01-01

    In a closed ecological system it is necessary to reclaim most of the oxygen required for breathing from respired carbon dioxide and the remainder from waste water. One of the advanced physicochemical systems being developed for generating oxygen in manned spacecraft is the solid electrolyte-electrolysis system. The solid electrolyte system consists of two basic units, an electrolyzer and a carbon monoxide disproportionator. The electrolyzer can reclaim oxygen from both carbon dioxide and water. Electrolyzer preparation and assembly are discussed together with questions of reactor design and electrolyzer performance data.

  9. Theoretical studies on the nitrogen dioxide dimer and isomerization mechanisms%二氧化氮二聚体及异构化机理的理论研究

    Institute of Scientific and Technical Information of China (English)

    靳玲侠; 闵锁田; 王志银; 赵梦婷

    2016-01-01

    The nitrogen dioxide dimer and isomerization mechanisms have been studied by CBS -QB3 method .Three tautomers and transition state are located .The reaction enthalpies , activation free energies and the rate constants of tautomerism are also obtained .The results indicate that the thermodynamic stability of complexes is M3>M2>M1.The pathway from M3 to M2 via transition state TSM3/M2 is found.The activa-tion free energy associated with this step is 29.50 kJ· mol-1 , and the rate constant is 4.2 ×107 s-1 , sugges-ting this reaction is easier to be happen .%采用CBS-QB3组合方法对二氧化氮二聚体结构及异构化机理进行研究,获得了3种稳定异构体及部分异构化过渡态,并计算出其互变反应过程的反应焓、活化吉布斯自由能及反应速率常数等参数。结果表明:3种二聚体的相对稳定性为M3>M2>M1。同时发现, M3和M2构型可以通过键旋转方式实现相互转化,反应主通道为M3→TSM3/M2→M2,该步骤的活化吉布斯自由能为29.50 kJ· mol-1,反应速率常数为4.2×107 s-1,因此M3极易向M2转化。

  10. Chronic nitrogen addition causes a reduction in soil carbon dioxide efflux during the high stem-growth period in a tropical montane forest but no response from a tropical lowland forest on a decadal time scale

    Directory of Open Access Journals (Sweden)

    B. Koehler

    2009-12-01

    Full Text Available Atmospheric nitrogen (N deposition is rapidly increasing in tropical regions. We studied the response of soil carbon dioxide (CO2 efflux to long-term experimental N addition (125 kg N ha−1 yr−1 in mature lowland and montane forests in Panama. In the lowland forest, on soils with high nutrient-supplying and buffering capacity, fine litterfall and stem-growth were neither N- nor phosphorus-limited. In the montane forest, on soils with low nutrient supplying capacity and an organic layer, fine litterfall and stem-growth were N-limited. Our objectives were to 1 explore the influence of soil temperature and moisture on the dynamics of soil CO2 efflux and 2 determine the responses of soil CO2 efflux from an N-rich and N-limited forest to elevated N input. Annual soil CO2-C efflux was larger in the lowland (15.44 ± 1.02 Mg C ha−1 than in the montane forest (9.37 ± 0.28 Mg C ha−1. In the lowland forest, soil moisture explained the largest fraction of the variance in soil CO2 efflux while soil temperature was the main explanatory variable in the montane forest. Soil CO2 efflux in the lowland forest did not differ between the control and 9–11 yr N-addition plots, suggesting that chronic N input to nutrient-rich tropical lowland forests on well-buffered soils may not change their C balance on a decadal time scale. In the montane forest, first year N addition did not affect soil CO2 efflux but annual CO2 efflux was reduced by 14% and 8% in the 2nd and 3rd year N-addition plots, respectively, compared to the control. This reduction was caused by a decrease in soil CO2 efflux during the high stem-growth period of the year, suggesting a shift in carbon partitioning from below- to aboveground in the N-addition plots in which stem diameter growth was promoted.

  11. Chronic nitrogen addition causes a reduction in soil carbon dioxide efflux during the high stem-growth period in a tropical montane forest but no response from a tropical lowland forest in decadal scale

    Directory of Open Access Journals (Sweden)

    B. Koehler

    2009-09-01

    Full Text Available Atmospheric nitrogen (N deposition is rapidly increasing in tropical regions. We studied the response of soil carbon dioxide CO2 efflux to long-term experimental N-addition (125 kg N ha−1 yr-1 in mature lowland and montane forests in Panamá. In the lowland forest, on soils with high nutrient-supplying and buffering capacity, fine litterfall and stem-growth were neither N- nor phosphorus-limited. In the montane forest, on soils with low nutrient supplying capacity and an organic layer, fine litterfall and stem-growth were N-limited. Our objectives were to 1 explore the influence of soil temperature and moisture on the dynamics of soil CO2 efflux and 2 determine the responses of soil CO2 efflux from an N-rich and N-limited forest to elevated N input. Annual soil CO2-C efflux was larger from the lowland (15.20±1.25 Mg C ha−1 than the montane forest (9.36±0.29 Mg C ha−1. In the lowland forest, soil moisture explained the largest fraction of the variance in soil CO2 efflux while soil temperature was the main explanatory variable in the montane forest. Soil CO2 efflux in the lowland forest did not differ between the control and 9–11 yr N-addition plots, suggesting that chronic N input to nutrient-rich tropical lowland forests on well-buffered soils may not change their C balance in decadal scale. In the montane forest, first year N addition did not affect soil CO2 efflux but annual CO2 efflux was reduced by 14% and 8% in the 2- and 3 yr N-addition plots, respectively, compared to the control. This reduction was caused by a decrease in soil CO2 efflux during the high stem-growth period of the year, suggesting a shift in carbon partitioning from below- to aboveground in the N-addition plots where stem diameter growth was promoted.

  12. Nitrogen dioxide observations from the Geostationary Trace ...

    Science.gov (United States)

    The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument is a test bed for upcoming air quality satellite instruments that will measure backscattered ultraviolet, visible and near-infrared light from geostationary orbit. GeoTASO flew on the NASA Falcon aircraft in its first intensive field measurement campaign during the Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) Earth Venture Mission over Houston, Texas, in September 2013. Measurements of backscattered solar radiation between 420 and 465 nm collected on 4 days during the campaign are used to determine slant column amounts of NO2 at 250 m  ×  250 m spatial resolution with a fitting precision of 2.2 × 1015 moleculescm−2. These slant columns are converted to tropospheric NO2 vertical columns using a radiative transfer model and trace gas profiles from the Community Multiscale Air Quality (CMAQ) model. Total column NO2 from GeoTASO is well correlated with ground-based Pandora observations (r = 0.90 on the most polluted and cloud-free day of measurements and r = 0.74 overall), with GeoTASO NO2 slightly higher for the most polluted observations. Surface NO2 mixing ratios inferred from GeoTASO using the CMAQ model show good correlation with NO2 measured in situ at the surface during the campaign (r = 0.85). NO2 slant columns from GeoTASO also agree well with prelim

  13. 2012 Nitrogen Dioxide Monitoring Site Design Values

    Data.gov (United States)

    U.S. Environmental Protection Agency — A design value is a statistic that describes the air quality status of a given location relative to the level of the National Ambient Air Quality Standards (NAAQS)....

  14. Nonattainment Area - Nitrogen Dioxide (NO2 - 1990)

    Data.gov (United States)

    Department of Transportation — Non-attainment and maintenance areas for the United States and its territories (NTAD 2015). The standard for the NO2 NAA is 0.053 ppm. For more detailed information...

  15. Mechanochemical Synthesis of Visible-light Induced Photocatalyst with Nitrogen and Carbon Doping

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Nitrogen and/or carbon doped titania photocatalysts were prepared by a novel mechanochemical method. The prepared powders possessed two absorption edges around 400 and 540 nm wavelengths and showed excellent photocatalytic ability for nitrogen monoxide oxidation under visible light irradiation. Under the irradiation of visible light of wavelength >510 nm, 37% of nitrogen monoxide could be continuously removed by the carbon and nitrogen co-doped titania prepared by planetary ball milling of P-25 titania-10% hexamethylenetetramine mixture followed by calcination in air at 400 ℃.

  16. Assessment of carbon monoxide values in smokers: a comparison of carbon monoxide in expired air and carboxyhaemoglobin in arterial blood

    DEFF Research Database (Denmark)

    Andersson, Mette F; Møller, Ann M

    2010-01-01

    Smoking increases perioperative complications. Carbon monoxide concentrations can estimate patients' smoking status and might be relevant in preoperative risk assessment. In smokers, we compared measurements of carbon monoxide in expired air (COexp) with measurements of carboxyhaemoglobin (COHb...

  17. Biological Effects of Short, High-Level Exposure to Gases: Nitrogen Oxides.

    Science.gov (United States)

    1980-07-01

    SUPPLEMENTARY NOT ES3 This project was one of four under the same contract; the others covered ammonia , carbon monoxide, and sulfur dioxide. 3 IS. KEY wOROS...characterize the biological responses to short, high-level exposures to four gases associated with certain Army weapons systems ( ammonia , carbon monoxide...20- i --- 7 (2) Biochemical and Other Effects Buckley and BalchumlO found biochemical changes, principally in enzyme activity of the liver, spleen

  18. Hearing Loss due to Carbon Monoxide Poisoning

    DEFF Research Database (Denmark)

    Mehrparvar, Amir Houshang; Davari, Mohammad Hossein; Mollasadeghi, Abolfazl

    2013-01-01

    Carbon monoxide poisoning is one of the rare causes of hearing loss which may cause reversible or irreversible, unilateral or bilateral hearing loss after acute or chronic exposure. In this report, we present a case of bilateral sensorineural hearing loss in a secondary smelting workshop worker...

  19. Carbon dioxide foaming of glassy polymers

    NARCIS (Netherlands)

    Wessling, M.; Borneman, Z.; Boomgaard, van den Th.; Smolders, C.A.

    1994-01-01

    The mechanism of foaming a glassy polymer using sorbed carbon dioxide is studied in detail. A glassy polymer supersaturated with nitrogen forms a microcellular foam, if the polymer is quickly heated above its glass transition temperature. A glassy polymer supersaturated with CO2 forms this foam-like

  20. Dinitrogen cleavage and functionalization by carbon monoxide promoted by a hafnium complex.

    Science.gov (United States)

    Knobloch, Donald J; Lobkovsky, Emil; Chirik, Paul J

    2010-01-01

    Molecular nitrogen (N(2)) and carbon monoxide (CO) have the two strongest bonds in chemistry and present significant challenges in developing new transformations that exploit these two abundant feedstocks. At the core of this objective is the discovery of transition-metal compounds that promote the six-electron reductive cleavage of N(2) at ambient temperature and pressure and also promote new nitrogen-element bond formation. Here we show that an organometallic hafnium compound induces N(2) cleavage on the addition of CO, with a simultaneous assembly of new nitrogen-carbon and carbon-carbon bonds. Subsequent addition of a weak acid liberates oxamide, which demonstrates that an important agrochemical can be synthesized directly from N(2) and CO. These studies introduce an alternative paradigm for N(2) cleavage and functionalization in which the six-electron reductive cleavage is promoted by both the transition metal and the incoming ligand, CO, used for the new bond formations.

  1. Comment on the paper ;NDSD-1000: High-resolution, high-temperature nitrogen dioxide spectroscopic Databank; by A.A. Lukashevskaya, N.N. Lavrentieva, A.C. Dudaryonok, V.I. Perevalov, J Quant Spectrosc Radiat Transfer 2016;184:205-17

    Science.gov (United States)

    Perrin, A.; Ndao, M.; Manceron, L.

    2017-10-01

    A recent paper [1] presents a high-resolution, high-temperature version of the Nitrogen Dioxide Spectroscopic Databank called NDSD-1000. The NDSD-1000 database contains line parameters (positions, intensities, self- and air-broadening coefficients, exponents of the temperature dependence of self- and air-broadening coefficients) for numerous cold and hot bands of the 14N16O2 isotopomer of nitrogen dioxide. The parameters used for the line positions and intensities calculation were generated through a global modeling of experimental data collected in the literature within the framework of the method of effective operators. However, the form of the effective dipole moment operator used to compute the NO2 line intensities in the NDSD-1000 database differs from the classical one used for line intensities calculation in the NO2 infrared literature [12]. Using Fourier transform spectra recorded at high resolution in the 6.3 μm region, it is shown here, that the NDSD-1000 formulation is incorrect since the computed intensities do not account properly for the (Int(+)/Int(-)) intensity ratio between the (+) (J = N+ 1/2) and (-) (J = N-1/2) electron - spin rotation subcomponents of the computed vibration rotation transitions. On the other hand, in the HITRAN or GEISA spectroscopic databases, the NO2 line intensities were computed using the classical theoretical approach, and it is shown here that these data lead to a significant better agreement between the observed and calculated spectra.

  2. Studies on the uptake and incorporation of anthropogenic nitrogen oxides (NO{sub x}) by sunflowers and maize by using {sup 15}N isotope tracers; Untersuchungen zur Aufnahme und zum Einbau von anthropogenen Stickoxiden (NO{sub x}) durch Sonnenblumen und Mais mittels {sup 15}N-Isotopen-Markierung

    Energy Technology Data Exchange (ETDEWEB)

    Segschneider, H.J.

    1994-05-01

    The aim of the present thesis was to quantify the uptake of nitrogen dioxide (NO{sub 2}) and nitrogen monoxide (NO) by sunflowers (Helianthus annuus L.) and maize (Zea mays L.) in a concentration range corresponding to the concentration range in the present atmosphere. Furthermore, work was carried out on characterizing the parameters responsible for NO{sub 2} and NO uptake by varying the different exposure conditions. In addition by applying {sup 15}N-enriched nitrogen oxides ({sup 15}NO{sub 2}; {sup 15}NO) it was also possible to investigate the incorporation and distribution of the {sup 15}NO{sub x} nitrogen in the plants. After an appropriate cultivation phase, the plants were transferred individually into a specially designed exposure system (Latus, 1989). Quantification of the NO{sub 2} or NO uptake was carried out by two independent measuring methods. On the one hand, the quantities of NO{sub 2} or NO taken up by the plants were determined via the NO{sub 2} concentration difference between the chamber inlet and outlet. On the other hand, the NO{sub 2} and NO uptake was calculated after exposure to {sup 15}N-enriched nitrogen oxides by determining the {sup 15}N/{sup 14}N ratio in the exposed plants using mass spectrometry. Furthermore, by using various analytical procedures it was possible to determine the sizes of the different nitrogen pools in the plants and to evaluate them by mass spectrometry. (orig./UG)

  3. Interaction and reactivity of nitric oxide and carbon monoxide on ruthenium surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Quick, E.E.

    1980-03-01

    A multifaceted investigation of the reduction of nitric oxide by carbon monoxide using a ruthenium (102) single crystal catalyst in the pressure range 10/sup -3/ to 10 Torr and temperature range of 300 to 475/sup 0/C has been undertaken. Kinetic and isotopic results indicate that the reaction products CO/sub 2/ and N/sub 2/ were produced via two reaction mechanisms. Using a reducing gas mixture (low P/sub NO//P/sub CO/ ratio) a two site mechanism was operative involving NO dissociation. The carbon monoxide kinetic order varied from +1 to -3 and the nitric oxide order varied from +1 to 0. The catalyst under these conditions was determined to be metallic ruthenium with oxygen bonded within the first surface layer. The oxygen was unreactive and formed a (1 x 3)-0 LEED pattern. Under oxidizing conditions (high P/sub NO//P/sub CO/ ratio) the catalyst was ruthenium dioxide and the functional mechanism under these reaction conditions yielded a nitric oxide order of +2 to -4. Inclusion of a site poisoning mechanism under reducing conditions and an RuO/sub 2/ growth mechanism involving ruthenium cation transfer under oxidizing conditions into the kinetic rate laws led to an overall rate law which could be fit to the carbon monoxide and nitric oxide order plots. Using isotopically oxygen labelled reactants, it was observed that the three possible isotopes of carbon dioxide were produced. A ..gamma..-CO surface species is postulated as an intermediate in the exchange process. The reaction was observed to be initially surface structure insensitive and the reaction kinetics were derived using a Langmuir-Hinshelwood formalism.

  4. Modeling the chemical evolution of nitrogen oxides near roadways

    Science.gov (United States)

    Wang, Yan Jason; DenBleyker, Allison; McDonald-Buller, Elena; Allen, David; Zhang, K. Max

    2011-01-01

    The chemical evolution of nitrogen dioxide (NO 2) and nitrogen monoxide (NO) in the vicinity of roadways is numerically investigated using a computational fluid dynamics model, CFD-VIT-RIT and a Gaussian-based model, CALINE4. CFD-VIT-RIT couples a standard k- ɛ turbulence model for turbulent mixing and the Finite-Rate model for chemical reactions. CALINE4 employs a discrete parcel method, assuming that chemical reactions are independent of the dilution process. The modeling results are compared to the field measurement data collected near two roadways in Austin, Texas, State Highway 71 (SH-71) and Farm to Market Road 973 (FM-973), under parallel and perpendicular wind conditions during the summer of 2007. In addition to ozone (O 3), other oxidants and reactive species including hydroperoxyl radical (HO 2), organic peroxyl radical (RO 2), formaldehyde (HCHO) and acetaldehyde (CH 3CHO) are considered in the transformation from NO to NO 2. CFD-VIT-RIT is shown to be capable of predicting both NO x and NO 2 profiles downwind. CALINE4 is able to capture the NO x profiles, but underpredicts NO 2 concentrations under high wind velocity. Our study suggests that the initial NO 2/NO x ratios have to be carefully selected based on traffic conditions in order to assess NO 2 concentrations near roadways. The commonly assumed NO 2/NO x ratio by volume of 5% may not be suitable for most roadways, especially those with a high fraction of heavy-duty truck traffic. In addition, high O 3 concentrations and high traffic volumes would lead to the peak NO 2 concentration occurring near roadways with elevated concentrations persistent over a long distance downwind.

  5. High capacity carbon dioxide sorbent

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, Steven Dean; Alptekin, Gokhan; Jayaraman, Ambalavanan

    2015-09-01

    The present invention provides a sorbent for the removal of carbon dioxide from gas streams, comprising: a CO.sub.2 capacity of at least 9 weight percent when measured at 22.degree. C. and 1 atmosphere; an H.sub.2O capacity of at most 15 weight percent when measured at 25.degree. C. and 1 atmosphere; and an isosteric heat of adsorption of from 5 to 8.5 kilocalories per mole of CO.sub.2. The invention also provides a carbon sorbent in a powder, a granular or a pellet form for the removal of carbon dioxide from gas streams, comprising: a carbon content of at least 90 weight percent; a nitrogen content of at least 1 weight percent; an oxygen content of at most 3 weight percent; a BET surface area from 50 to 2600 m.sup.2/g; and a DFT micropore volume from 0.04 to 0.8 cc/g.

  6. Carbon dioxide retention in divers

    Energy Technology Data Exchange (ETDEWEB)

    Florio, J.T.; Mackenzie, D.A.R.; McKenzie, R.S. [ARE Physiological Laboratory, Gosport (United Kingdom)

    1998-04-01

    This report summarises the work carried out at the ARE Physiological Laboratory (ARE(PL)) between July 1978 and December 1983. The work was intended to examine the proposition that some divers have a low ventilatory response to carbon dioxide; that this results in a low ventilatory response to exercise with consequent hypercapnia; and that these characteristics put the diver at a greater-than-normal risk by increasing the individual`s susceptibility to oxygen toxicity and to other hazards associated with diving (e.g. nitrogen narcosis, decompression sickness and hypothermia). The specific aims of the project can be summarised as follows: (a) to demonstrate the existence of divers who exhibit the tendency to `retain carbon dioxide` when working in hyperbaric conditions; (b) to define the circumstances under which such individuals are at risk; (c) to assess the magnitude of the risk; and (d) to recommend ways to eliminate or to reduce the risk. (author)

  7. Nitrogen oxides emission of mobile equipment in the port of Rotterdam. Consequences for nitrogen dioxide concentration, nitrogen deposition and a deduction of emission factors for container and bulk businesses; Stikstofoxidenemissies van mobiele werktuigen in de Rotterdamse haven. Gevolgen voor stikstofdioxide concentratie, stikstofdepositie, en een afleiding van emissiefactoren voor container- en droge bulk bedrijven

    Energy Technology Data Exchange (ETDEWEB)

    Okkerse, W.J.H.; De Gier, C.W.

    2011-08-15

    In container terminals, dry bulk businesses and construction sites in the port of Rotterdam, the Netherlands, large masses of goods are transported by means of diesel-fuelled equipment every year. The combustion of diesel in this equipment results in emissions of nitrogen oxides (NOx) and particulate matter. This study has calculated the amounts of NOx emissions of the involved businesses based on detailed data on the composition of the equipment fleet of six representative storage and transshipment businesses. The resulting contribution to nitrogen oxide concentration at ground level and the nitrogen deposition have been calculated with the OPS model (Operational Priority Substances) [Dutch] Bij containerterminals, droge bulk bedrijven en bouwplaatsen in de Rotterdamse haven wordt jaarlijks een grote massa aan goederen getransporteerd met behulp van dieselaangedreven apparatuur. De verbranding van diesel in deze apparatuur zorgt voor de emissie van stikstofoxiden (NOx) en stof. In dit onderzoek zijn de NOx emissies van de betrokken bedrijven berekend op basis van gedetailleerde gegevens over de samenstelling van het werktuigenpark van zes representatieve op- en overslagbedrijven. De resulterende bijdrage aan de stikstofdioxide (NO2) concentratie op leefniveau en de stikstofdepositie is berekend met het OPS-model (Operationele Prioritaire Stoffen)

  8. Combustion synthesis of tin dioxide nanocomposites for gas sensing applications

    Science.gov (United States)

    Bakrania, Smitesh Dhirajlal

    The current work focuses on understanding the mechanisms controlling tin dioxide (SnO2) nanoparticle morphology in combustion synthesis systems and how nanoarchitecture affects performance of solid-state gas sensors. A range of analytical methods (including transmission and scanning electron microscopy, x-ray diffraction, nitrogen absorption, and XEDS) were used to characterize the materials properties as a function of the combustion synthesis conditions. A novel method of generating tin dioxide materials was developed which provides a new degree of control over SnO2 morphology; including spherical, nanorod and encapsulated particle architectures. A simplified model for particle formation based on characteristic times was developed to identify the physical and chemical processes affecting the morphologies observed using transmission electron microscope imaging. The SnO2 nanoparticles evolve from primary particles sizes of 7 nm to 14 nm through the synthesis region, and the results indicate interparticle collision and sintering are the dominant mechanisms in determining particle size and morphology for the flame conditions studied. Metal acetates were used to create metal/SnO 2 nanocomposite materials, and the processes controlling gold acetate decomposition in particular were explored. The results of the studies suggest a relationship between the precursor crystallite size and the product nanoparticles. The well-characterized SnO2 particles were evaluated as the active materials for gas-sensing. Sensor sensitivity and time response to carbon monoxide in dry air was used to investigate microstructure-performance links. Excellent sensitivity (3 7, based on the ratio of the resistance of the sensor in air to the resistance in the target gas) and time response (4--20 seconds) were demonstrated for the thin film gas sensors. Fabrication studies demonstrated the sensor performance was a strong function of the film deposition method. A novel method for manufacturing

  9. Photosynthetic carbon monoxide metabolism by sugarcane leaves

    Energy Technology Data Exchange (ETDEWEB)

    Kortschak, H.P.; Nickell, L.G.

    1973-01-01

    The photosynthetic carbon monoxide metabolism by sugarcane was studied to determine whether substantial quantities of CO are removed from the air by fields in Hawaii. Leaves metabolized low CO concentrations photosynthetically, with sucrose as an end product. Rates of uptake were of the order of 10/sup -4/ power mg/d sq m/hr. This was to low to be significant in removing CO from the atmosphere.

  10. Sensorineural Hearing Loss following Carbon Monoxide Poisoning

    Directory of Open Access Journals (Sweden)

    Joseph P. Pillion

    2012-01-01

    Full Text Available A case study is presented of a 17-year-old male who sustained an anoxic brain injury and sensorineural hearing loss secondary to carbon monoxide poisoning. Audiological data is presented showing a slightly asymmetrical hearing loss of sensorineural origin and mild-to-severe degree for both ears. Word recognition performance was fair to poor bilaterally for speech presented at normal conversational levels in quiet. Management considerations of the hearing loss are discussed.

  11. PENTACARBON DIOXIDE (C{sub 5}O{sub 2}) FORMATION AND ITS ROLE AS A TRACER OF SOLAR SYSTEM EVOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    Förstel, Marko; Maksyutenko, Pavlo; Kaiser, Ralf I. [W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa, Honolulu, Hawaii, HI 96822 (United States); Mebel, Alexander M., E-mail: ralfk@hawaii.edu [Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL 33193 (United States)

    2016-02-20

    Carbon monoxide is the second most abundant molecule on icy grains in the interstellar medium. These grains are under the influence of ionizing radiation, which induces the chemical reaction within the ice. Here we report the first observation of subliming pentacarbon dioxide (C{sub 5}O{sub 2}) after irradiation of pure carbon monoxide ice with energetic electrons. Our results show that pentacarbon dioxide is a stable reaction product in a carbon monoxide matrix that survives the sublimation in star-forming regions at sublimation temperatures of 175 K. Along with carbon suboxide (C{sub 3}O{sub 2}), this molecule can serve as a powerful tracer of the temperature history of formerly carbon monoxide rich ices in molecular clouds and star-forming regions.

  12. Enriching blast furnace gas by removing carbon dioxide.

    Science.gov (United States)

    Zhang, Chongmin; Sun, Zhimin; Chen, Shuwen; Wang, Baohai

    2013-12-01

    Blast furnace gas (BF gas) produced in the iron making process is an essential energy resource for a steel making work. As compared with coke oven gas, the caloric value of BF gas is too low to be used alone as fuel in hot stove because of its high concentrations of carbon dioxide and nitrogen. If the carbon dioxide in BF gas could be captured efficiently, it would meet the increasing need of high caloric BF gas, and develop methods to reusing and/or recycling the separated carbon dioxide further. Focused on this, investigations were done with simple evaluation on possible methods of removing carbon dioxide from BF gas and basic experiments on carbon dioxide capture by chemical absorption. The experimental results showed that in 100 minutes, the maximum absorbed doses of carbon dioxide reached 20 g/100 g with ionic liquid as absorbent.

  13. Heme oxygenase-1 and carbon monoxide in pulmonary medicine.

    Science.gov (United States)

    Slebos, Dirk-Jan; Ryter, Stefan W; Choi, Augustine M K

    2003-01-01

    Heme oxygenase-1 (HO-1), an inducible stress protein, confers cytoprotection against oxidative stress in vitro and in vivo. In addition to its physiological role in heme degradation, HO-1 may influence a number of cellular processes, including growth, inflammation, and apoptosis. By virtue of anti-inflammatory effects, HO-1 limits tissue damage in response to proinflammatory stimuli and prevents allograft rejection after transplantation. The transcriptional upregulation of HO-1 responds to many agents, such as hypoxia, bacterial lipopolysaccharide, and reactive oxygen/nitrogen species. HO-1 and its constitutively expressed isozyme, heme oxygenase-2, catalyze the rate-limiting step in the conversion of heme to its metabolites, bilirubin IXalpha, ferrous iron, and carbon monoxide (CO). The mechanisms by which HO-1 provides protection most likely involve its enzymatic reaction products. Remarkably, administration of CO at low concentrations can substitute for HO-1 with respect to anti-inflammatory and anti-apoptotic effects, suggesting a role for CO as a key mediator of HO-1 function. Chronic, low-level, exogenous exposure to CO from cigarette smoking contributes to the importance of CO in pulmonary medicine. The implications of the HO-1/CO system in pulmonary diseases will be discussed in this review, with an emphasis on inflammatory states.

  14. Heme oxygenase-1 and carbon monoxide in pulmonary medicine

    Directory of Open Access Journals (Sweden)

    Choi Augustine MK

    2003-08-01

    Full Text Available Abstract Heme oxygenase-1 (HO-1, an inducible stress protein, confers cytoprotection against oxidative stress in vitro and in vivo. In addition to its physiological role in heme degradation, HO-1 may influence a number of cellular processes, including growth, inflammation, and apoptosis. By virtue of anti-inflammatory effects, HO-1 limits tissue damage in response to proinflammatory stimuli and prevents allograft rejection after transplantation. The transcriptional upregulation of HO-1 responds to many agents, such as hypoxia, bacterial lipopolysaccharide, and reactive oxygen/nitrogen species. HO-1 and its constitutively expressed isozyme, heme oxygenase-2, catalyze the rate-limiting step in the conversion of heme to its metabolites, bilirubin IXα, ferrous iron, and carbon monoxide (CO. The mechanisms by which HO-1 provides protection most likely involve its enzymatic reaction products. Remarkably, administration of CO at low concentrations can substitute for HO-1 with respect to anti-inflammatory and anti-apoptotic effects, suggesting a role for CO as a key mediator of HO-1 function. Chronic, low-level, exogenous exposure to CO from cigarette smoking contributes to the importance of CO in pulmonary medicine. The implications of the HO-1/CO system in pulmonary diseases will be discussed in this review, with an emphasis on inflammatory states.

  15. Compact Instrument for Measurement of Atmospheric Carbon Monoxide Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Southwest Sciences proposed the development of a rugged, compact, and automated instrument for the high sensitivity measurement of tropospheric carbon monoxide...

  16. A metal-free electrocatalyst for carbon dioxide reduction to multi-carbon hydrocarbons and oxygenates.

    Science.gov (United States)

    Wu, Jingjie; Ma, Sichao; Sun, Jing; Gold, Jake I; Tiwary, ChandraSekhar; Kim, Byoungsu; Zhu, Lingyang; Chopra, Nitin; Odeh, Ihab N; Vajtai, Robert; Yu, Aaron Z; Luo, Raymond; Lou, Jun; Ding, Guqiao; Kenis, Paul J A; Ajayan, Pulickel M

    2016-12-13

    Electroreduction of carbon dioxide into higher-energy liquid fuels and chemicals is a promising but challenging renewable energy conversion technology. Among the electrocatalysts screened so far for carbon dioxide reduction, which includes metals, alloys, organometallics, layered materials and carbon nanostructures, only copper exhibits selectivity towards formation of hydrocarbons and multi-carbon oxygenates at fairly high efficiencies, whereas most others favour production of carbon monoxide or formate. Here we report that nanometre-size N-doped graphene quantum dots (NGQDs) catalyse the electrochemical reduction of carbon dioxide into multi-carbon hydrocarbons and oxygenates at high Faradaic efficiencies, high current densities and low overpotentials. The NGQDs show a high total Faradaic efficiency of carbon dioxide reduction of up to 90%, with selectivity for ethylene and ethanol conversions reaching 45%. The C2 and C3 product distribution and production rate for NGQD-catalysed carbon dioxide reduction is comparable to those obtained with copper nanoparticle-based electrocatalysts.

  17. A metal-free electrocatalyst for carbon dioxide reduction to multi-carbon hydrocarbons and oxygenates

    Science.gov (United States)

    Wu, Jingjie; Ma, Sichao; Sun, Jing; Gold, Jake I.; Tiwary, Chandrasekhar; Kim, Byoungsu; Zhu, Lingyang; Chopra, Nitin; Odeh, Ihab N.; Vajtai, Robert; Yu, Aaron Z.; Luo, Raymond; Lou, Jun; Ding, Guqiao; Kenis, Paul J. A.; Ajayan, Pulickel M.

    2016-12-01

    Electroreduction of carbon dioxide into higher-energy liquid fuels and chemicals is a promising but challenging renewable energy conversion technology. Among the electrocatalysts screened so far for carbon dioxide reduction, which includes metals, alloys, organometallics, layered materials and carbon nanostructures, only copper exhibits selectivity towards formation of hydrocarbons and multi-carbon oxygenates at fairly high efficiencies, whereas most others favour production of carbon monoxide or formate. Here we report that nanometre-size N-doped graphene quantum dots (NGQDs) catalyse the electrochemical reduction of carbon dioxide into multi-carbon hydrocarbons and oxygenates at high Faradaic efficiencies, high current densities and low overpotentials. The NGQDs show a high total Faradaic efficiency of carbon dioxide reduction of up to 90%, with selectivity for ethylene and ethanol conversions reaching 45%. The C2 and C3 product distribution and production rate for NGQD-catalysed carbon dioxide reduction is comparable to those obtained with copper nanoparticle-based electrocatalysts.

  18. Study on Nitrogen-doped Titanium Dioxide's Degradation of Nirogen Pollutants in Water with Visible Light Photocatalysis%氮掺杂的二氧化钛可见光催化降解水中含氮污染物的研究

    Institute of Scientific and Technical Information of China (English)

    张瑶; 李利辉; 严亚

    2015-01-01

    目的:探讨可见光照射下氮掺杂的二氧化钛对水中含氮污染物的降解活性.方法:以硫脲为氮源,用水热法制备不同比例的氮掺杂二氧化钛.用X射线衍射、透射电子显微镜对产物的结构、形貌进行表征.在可见光照射下,以罗丹明B为模型染料污染物,考察所制备的系列样品的可见光催化活性.以乙酰甲胺磷为含氮的模型污染物考察最佳比例的氮掺杂的二氧化钛样品对水环境中的含氮污染物的降解活性.结果:掺杂适量的氮可以提高二氧化钛纳米粒子的可见光催化活性,氮的掺杂量为1.0%时可见光催化活性最高.水环境中总氮含量为Ⅳ类水时,经1.0%氮掺杂的二氧化钛可见光催化降解4 h,样品液的总氮含量可接近Ⅱ类水.结论:氮掺杂的二氧化钛在可见光下可有效降解水中的含氮污染物.%Objective: To investigate the degradation activity of nitrogen-doped titanium dioxide to the Nitrogen pollutants with visible light photocatalysis. Methods: Nitrogen-doped titanium oxides (N-TiO2) with different amounts of N were prepared via hydrothermal method by using thiourea as nitrogen source. The structure and morphology of N-TiO2 were characterized by X-ray powder diffraction(XRD)and transmission electron microscopy(TEM)respectively. The visible light photocatalysis activities of the N-TiO2 series samples were evaluated by the degradation of rhodamine B in aqueous solution, and the nitrogen pollutant degradation activity of the optimum N-TiO2 on the nitrogen pollutants were explored by using acephate as the nitrogen model pollutant. Results:The visible light photocatalysis activity of TiO2 was enhanced when appropriate amount nitrogen was doped into TiO2, and 1.0%N-TiO2 showed the highest visible light photocatalysis activity. The total nitrogen can be degraded from classⅣwater quality to classⅡwater quality after 4 hours' visible light irradiation using 1.0%N-TiO2 as the photocatalyst

  19. Analysis of Carbon Monoxide in Blood

    Science.gov (United States)

    Huddle, Benjamin P.; Stephens, Joseph C.

    2003-04-01

    Forensic tests used to perform the qualitative and quantitative analyses of carbon monoxide in blood are described. The qualitative test uses the diffusion of CO, which is released from blood by reaction with H2SO4, into a PdCl2 solution in a Conway cell and the resultant formation of a palladium mirror. The quantitative analysis is based on the absorption of visible light by carboxyhemoglobin at 541 nm and reduced hemoglobin at 555 nm. Both procedures are suitable for undergraduate chemistry experiments.

  20. Titanium dioxide use (TiO{sub 2}) in cement matrix as a photocatalyst of nitrogen oxides (NO{sub x}); Utilizacao de dioxido de titanio (TiO{sub 2}) em matriz cimenticia como fotocatalisador de oxidos de nitrogenio (NO{sub x})

    Energy Technology Data Exchange (ETDEWEB)

    Casagrande, C.A.; Hotza, D.; Repette, W.L.; Jochem, L.F., E-mail: cezar.acasa@gmail.com [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

    2012-07-01

    The use of titanium dioxide (TiO{sub 2}) in the photodegradation of nitrogen oxides (NO{sub x}) is a technology that can contribute against to environmental pollution. This work shows the feasibility of using TiO{sub 2} in mortars for photocatalysis. The Degussa P25 titania were characterized chemically and physically, revealing that the sample consists of nanoparticles, but has become crowded. Tests Samples (TS) were manufactured with added titania and the NO{sub x} tests at 28, 60 and 120 days of age of TSs, showing that it was 3% capable of degrading 100% of the NO{sub x} gas flow. Proved that conditions like relative humidity, flow and radiation intensity are relevant when it comes to efficiency in photocatalysis, altering the efficiency by varying these conditions. The photocatalysis with titania in cement matrix was efficient in NO{sub x} degradation, presenting itself as a promising technique to control environmental pollution.

  1. A Density Functional Theory Study of Doped Tin Monoxide as a Transparent p-type Semiconductor

    KAUST Repository

    Bianchi Granato, Danilo

    2012-05-01

    In the pursuit of enhancing the electronic properties of transparent p-type semiconductors, this work uses density functional theory to study the effects of doping tin monoxide with nitrogen, antimony, yttrium and lanthanum. An overview of the theoretical concepts and a detailed description of the methods employed are given, including a discussion about the correction scheme for charged defects proposed by Freysoldt and others [Freysoldt 2009]. Analysis of the formation energies of the defects points out that nitrogen substitutes an oxygen atom and does not provide charge carriers. On the other hand, antimony, yttrium, and lanthanum substitute a tin atom and donate n-type carriers. Study of the band structure and density of states indicates that yttrium and lanthanum improves the hole mobility. Present results are in good agreement with available experimental works and help to improve the understanding on how to engineer transparent p-type materials with higher hole mobilities.

  2. [Carbon monoxide poisoning by a heating system].

    Science.gov (United States)

    Dietz, Eric; Gehl, Axel; Friedrich, Peter; Kappus, Stefan; Petter, Franz; Maurer, Klaus; Püschel, Klaus

    2016-01-01

    A case of accidental carbon monoxide poisoning in several occupants of two neighboring residential buildings in Hamburg-Harburg (Germany) caused by a defective gas central heating system is described. Because of leaks in one of the residential buildings and the directly adjacent wall of the neighboring house, the gas could spread and accumulated in both residential buildings, which resulted in a highly dangerous situation. Exposure to the toxic gas caused mild to severe intoxication in 15 persons. Three victims died still at the site of the accident. Measures to protect the occupants were taken only with a great delay. As symptoms were unspecific, it was not realized that the various alarms given by persons involved in the accident were related to the same cause. In order to take appropriate measures in time it is indispensible to recognize, assess and check potential risks, which can be done by using carbon monoxide warning devices and performing immediate COHb measurements with special pulse oximeters on site. Moreover, the COHb content in the blood should be routinely determined in all patients admitted to an emergency department with unspecific symptoms.

  3. Observations of iodine monoxide columns from satellite

    Directory of Open Access Journals (Sweden)

    A. Schönhardt

    2008-02-01

    Full Text Available Iodine species in the troposphere are linked to ozone depletion and new particle formation. In this study, a full year of iodine monoxide (IO columns retrieved from measurements of the SCIAMACHY satellite instrument is presented, coupled with a discussion of their uncertainties and the detection limits. The largest amounts of IO are found near springtime in the Antarctic. A seasonal variation of iodine monoxide in Antarctica is revealed with high values in springtime, slightly less IO in the summer period and again larger amounts in autumn. In winter, no elevated IO levels are found in the areas accessible to satellite measurements. This seasonal cycle is in good agreement with recent ground-based measurements in Antarctica. In the Arctic region, no elevated IO levels were found in the period analysed. This implies that different conditions with respect to iodine release exist in the two Polar Regions. To investigate possible release mechanisms, comparisons of IO columns with those of tropospheric BrO, and ice coverage are described and discussed. Some parallels and interesting differences between IO and BrO temporal and spatial distributions are identified. Overall, the large spatial coverage of satellite retrieved IO data and the availability of a long-term dataset provide new insight about the abundances and distributions of iodine compounds in the troposphere.

  4. Nitric oxide and carbon monoxide diffusing capacity of the lung

    NARCIS (Netherlands)

    Lee, I. van der

    2006-01-01

    The single breath diffusion capacity of the lung for carbon monoxide (DLCO) is measure for gas uptake by the lung, and consists of a membrane and a vascular component. Nitric oxide (NO) binds 400 times faster to hemoglobin than carbon monoxide, thus the uptake of NO by the blood is very large.

  5. Nitric oxide and carbon monoxide diffusing capacity of the lung

    NARCIS (Netherlands)

    Lee, I. van der

    2006-01-01

    The single breath diffusion capacity of the lung for carbon monoxide (DLCO) is measure for gas uptake by the lung, and consists of a membrane and a vascular component. Nitric oxide (NO) binds 400 times faster to hemoglobin than carbon monoxide, thus the uptake of NO by the blood is very large. There

  6. Fatal carbon monoxide intoxication after acetylene gas welding of pipes.

    Science.gov (United States)

    Antonsson, Ann-Beth; Christensson, Bengt; Berge, Johan; Sjögren, Bengt

    2013-06-01

    Acetylene gas welding of district heating pipes can result in exposure to high concentrations of carbon monoxide. A fatal case due to intoxication is described. Measurements of carbon monoxide revealed high levels when gas welding a pipe with closed ends. This fatality and these measurements highlight a new hazard, which must be promptly prevented.

  7. Real World of Industrial Chemistry: Organic Chemicals from Carbon Monoxide.

    Science.gov (United States)

    Kolb, Kenneth E.; Kolb, Doris

    1983-01-01

    Carbon Monoxide obtained from coal may serve as the source for a wide variety of organic compounds. Several of these compounds are discussed, including phosgene, benzaldehyde, methanol, formic acid and its derivatives, oxo aldehydes, acrylic acids, and others. Commercial reactions of carbon monoxide are highlighted in a table. (JN)

  8. Cooperative redox activation for carbon dioxide conversion

    Science.gov (United States)

    Lian, Zhong; Nielsen, Dennis U.; Lindhardt, Anders T.; Daasbjerg, Kim; Skrydstrup, Troels

    2016-12-01

    A longstanding challenge in production chemistry is the development of catalytic methods for the transformation of carbon dioxide into useful chemicals. Silane and borane promoted reductions can be fined-tuned to provide a number of C1-building blocks under mild conditions, but these approaches are limited because of the production of stoichiometric waste compounds. Here we report on the conversion of CO2 with diaryldisilanes, which through cooperative redox activation generate carbon monoxide and a diaryldisiloxane that actively participate in a palladium-catalysed carbonylative Hiyama-Denmark coupling for the synthesis of an array of pharmaceutically relevant diarylketones. Thus the disilane reagent not only serves as the oxygen abstracting agent from CO2, but the silicon-containing `waste', produced through oxygen insertion into the Si-Si bond, participates as a reagent for the transmetalation step in the carbonylative coupling. Hence this concept of cooperative redox activation opens up for new avenues in the conversion of CO2.

  9. Search of medical literature for indoor carbon monoxide exposure

    Energy Technology Data Exchange (ETDEWEB)

    Brennan, T.; Ivanovich, M.

    1995-12-01

    This report documents a literature search on carbon monoxide. The search was limited to the medical and toxicological databases at the National Library of Medicine (MEDLARS). The databases searched were Medline, Toxline and TOXNET. Searches were performed using a variety of strategies. Combinations of the following keywords were used: carbon, monoxide, accidental, residential, occult, diagnosis, misdiagnosis, heating, furnace, and indoor. The literature was searched from 1966 to the present. Over 1000 references were identified and summarized using the following abbreviations: The major findings of the search are: (1) Acute and subacute carbon monoxide exposures result in a large number of symptoms affecting the brain, kidneys, respiratory system, retina, and motor functions. (2) Acute and subacute carbon monoxide (CO) poisonings have been misdiagnosed on many occasions. (3) Very few systematic investigations have been made into the frequency and consequences of carbon monoxide poisonings.

  10. Circulating factors induce coronary endothelial ceIl activation foIlowing exposure to inhaled diesel exhaust and nitrogen dioxide in humans :Evidence from a novel translational in vitro model

    Science.gov (United States)

    The vascular toxicity of inhaled agents may be caused by soluble factors that are released into the systemic circulation. To confirm this in a straightforward manner, we obtained plasma from healthy human volunteers before and after exposure to diesel exhaust (DE) and nitrogen di...

  11. Smoke-inhalation injury and the effect of carbon monoxide in the sheep model

    Energy Technology Data Exchange (ETDEWEB)

    Shimazu, T.; Ikeuchi, H.; Hubbard, G.B.; Langlinais, P.C.; Mason, A.D.

    1990-01-01

    The role of carbon monoxide (CO) in causing the physiologic and anatomic changes characteristic of smoke inhalation injury was evaluated in 34 sheep. The smoke-exposed group received a dose of smoke known to produce mild inhalation injury. The CO group received a pure gas mixture that contained concentrations of oxygen, carbon dioxide, and CO similar to those in the smoke. Cardiopulmonary function was measured immediately after exposure, and 24 and 72 hours after exposure. The CO group showed a transient increase in cardiac output, but the smoke group showed no such response. The CO group maintained normal PaO2 levels during the 72-hour study period; the smoke group gradually developed hypoxemia. The lungs of the CO exposed animals had no discernible histologic changes. These results indicate that CO per se is not the primary etiologic agent of smoke inhalation injury.

  12. Carbamazepine degradation by photolysis and titanium dioxide photocatalysis.

    Science.gov (United States)

    Im, Jong-Kwon; Son, Hyun-Seok; Kang, Young-Min; Zoh, Kyung-Duk

    2012-07-01

    We investigated the degradation of carbamazepine by photolysis/ultraviolet (UV)-C only and titanium dioxide photocatalysis. The degradation of carbamazepine by UV-only and titanium-dioxide-only (adsorption) reactions were inefficient, however, complete degradation of carbamazepine was observed by titanium dioxide photocatalysis within 30 min. The rate of degradation increased as initial carbamazepine concentration decreased, and the removal kinetics fit well with the Langmuir-Hinshelwood model. The addition of methanol, a radical scavenger, decreased carbamazepine removal, suggesting that the hydroxide radical played an important role during carbamazepine degradation. The addition of oxygen during titanium dioxide photocatalysis accelerated hydroxide radical production, thus improving mineralization activity. The photocatalytic degradation was more efficient at a higher pH, whereas the removal of carbamazepine and acridine (a major intermediate) were more efficient under aerobic conditions. The mineralization of carbamazepine during photocatalysis produced various ionic by-products such as ammonium and nitrate by way of nitrogen dioxide.

  13. Electrochemical process for the preparation of nitrogen fertilizers

    Energy Technology Data Exchange (ETDEWEB)

    Aulich, Ted R [Grand Forks, ND; Olson, Edwin S [Grand Forks, ND; Jiang, Junhua [Grand Forks, ND

    2012-04-10

    The present invention provides methods and apparatus for the preparation of nitrogen fertilizers including ammonium nitrate, urea, urea-ammonium nitrate, and/or ammonia, at low temperature and pressure, preferably at ambient temperature and pressure, utilizing a source of carbon, a source of nitrogen, and/or a source of hydrogen or hydrogen equivalent. Implementing an electrolyte serving as ionic charge carrier, (1) ammonium nitrate is produced via the reduction of a nitrogen source at the cathode and the oxidation of a nitrogen source at the anode; (2) urea or its isomers are produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source; (3) ammonia is produced via the reduction of nitrogen source at the cathode and the oxidation of a hydrogen source or a hydrogen equivalent such as carbon monoxide or a mixture of carbon monoxide and hydrogen at the anode; and (4) urea-ammonium nitrate is produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source, and anodic oxidation of a nitrogen source. The electrolyte can be aqueous, non-aqueous, or solid.

  14. Effects of nitrogen addition and precipitation change on soil methane and carbon dioxide fluxes%施氮和降水格局改变对土壤CH4和CO2通量的影响

    Institute of Scientific and Technical Information of China (English)

    李伟; 白娥; 李善龙; 孙建飞; 彭勃; 姜萍

    2013-01-01

    氮沉降增加和降水格局改变是全球变化的两项重要内容,但是同时考虑上述两因素对温室气体CH4和CO2通量影响的原位双因子模拟研究还相当有限.本研究以长白山温带阔叶红松林土壤为研究对象,采用静态箱法研究了外施氮源(50 kg N·hm-2·a-1)和增减30%降水对土壤CH4和CO2通量的影响.结果表明:施氮能抑制土壤CH4吸收,有时甚至能将土壤对CH4的吸收转为释放,但这种抑制效应只能维持5d左右,且能在一定程度上改变CH4通量和环境因子(温度、土壤pH、粘粒含量)的相关关系.降水改变未能显著影响土壤CH4通量.对CO2通量而言,施氮能降低土壤CO2排放,长白山阔叶红松林连续施氮第4年的平均抑制效应为27.4%.长期连续施氮的平均抑制效应随施氮时间延长而逐渐增大,一定年限后达到最大值.单次施氮的抑制效应随时间延长逐渐减弱,并在1个月的施氮周期末期基本消失.施氮的抑制效应和土壤充水孔隙度(WFPS)呈显著负相关关系,且升温能增强施氮对CO2释放的抑制效应并延长抑制时间.施氮、降水有可能改变土壤呼吸的温度敏感性.本研究表明,长白山森林土壤氮素尚未达到一定阈值,未来氮沉降增加将抑制CO2的释放和CH4的吸收,因此总体来看施氮抑制土壤碳排放.%Increased nitrogen deposition and changed precipitation pattern are the two important factors of global change,while the in situ experiments studying how the two factors affect greenhouse gases CO2 and CH4 fluxes are still limited.Taking the temperate broad-leaved Korean pine (Pinus koraiensis) forest in Changbai Mountains of Northeast China as the object,and by using static chambers,this paper studied the effects of nitrogen addition (50 kg N · hm-2 · a-1) and changed precipitation regime (30% increase and decrease of precipitation) on the soil CO2 and CH4 fluxes.Nitrogen addition inhibited the soil CH4 consumption

  15. Reduction of carbon monoxide. Past research summary

    Energy Technology Data Exchange (ETDEWEB)

    Schrock, R.R.

    1981-10-01

    Research programs for the year on the preparation, characterization, and reactions of binuclear tantalum complexes are described. All evidence to date suggest the following of these dimeric molecules: (1) the dimer does not break into monomers under mild conditions; (2) intermolecular hydride exchange is not negligible, but it is slow; (3) intermolecular non-ionic halide exchange is fast; (4) the ends of the dimers can rotate partially with respect to one another. The binuclear tantalum hydride complexes were found to react with carbon monoxide to give a molecule which is the only example of reduction of CO by a transition metal hydride to give a complex containing a CHO ligand. Isonitrides also reacted in a similar manner with dimeric tantalum hydride. (ATT)

  16. Increasing Solar Absorption for Photocatalysis with Black Hydrogenated Titanium Dioxide Nanocrystals

    National Research Council Canada - National Science Library

    Xiaobo Chen; Lei Liu; Peter Y. Yu; Samuel S. Mao

    2011-01-01

    When used as a photocatalyst, titanium dioxide (TiO₂) absorbs only ultraviolet light, and several approaches, including the use of dopants such as nitrogen, have been taken to narrow the band gap of TiO₂...

  17. Kinetic analysis of photocatalytic oxidation of gas-phase formaldehyde over titanium dioxide.

    Science.gov (United States)

    Liu, Hongmin; Lian, Zhiwei; Ye, Xiaojiang; Shangguan, Wenfeng

    2005-07-01

    Degradation of formaldehyde with different initial concentration over titanium dioxide was carried out in a photocatalytic reactor. Photocatalytic rates were well described by the simplified Langmuir-Hinshelwood model. The kinetic analysis shows that the apparent first-order reaction coefficient is lower and half-life of photocatalysis is longer for low concentration than for high concentration formaldehyde. A network formation model of the photocatalytic products was established. Experimental results and analysis demonstrate that carbon dioxide concentration and carbon monoxide concentration in gas phase vary exponentially with the illumination time and may be even higher than gas-phase formaldehyde concentration if there is much pre-adsorbed formaldehyde in adsorption equilibrium on catalysts before illumination. Carbon monoxide is found to be one of the by-products during formaldehyde photooxidation.

  18. Syncope Associated with Carbon Monoxide Poisoning due to Narghile Smoking

    Directory of Open Access Journals (Sweden)

    Seda Ozkan

    2013-01-01

    Full Text Available Narghile smoking is a traditional method of tobacco use, and it has been practiced extensively for 400 years. Traditionally, narghile smoking is a matter of culture mainly in Middle East, Asia, and Africa. In recent years, its use as a social activity has increased worldwide, especially among young people. Narghile smoking is an unusual cause of carbon monoxide poisoning. Narghile smoking, compared to cigarette smoking, can result in more smoke exposure and greater levels of carbon monoxide. We present an acute syncope case of a 19-year-old male patient who had carbon monoxide poisoning after narghile smoking.

  19. [Plant responses to elevated atmospheric carbon dioxide and transmission to other trophic levels]. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lincoln, D.E.

    1995-10-01

    This program investigated how host plant responses to elevated atmospheric carbon dioxide may be transmitted to other trophic levels, especially leaf eating insects, and alter consumption of leaves and impare their function. Study results included the following findings: increased carbon dioxide to plants alters feeding by insect herbivores; leaves produced under higher carbon conditions contain proportionally less nitrogen; insect herbivores may have decreased reproduction under elevated carbon dioxide.

  20. The carbon dioxide cycle

    Science.gov (United States)

    James, P.B.; Hansen, G.B.; Titus, T.N.

    2005-01-01

    The seasonal CO2 cycle on Mars refers to the exchange of carbon dioxide between dry ice in the seasonal polar caps and gaseous carbon dioxide in the atmosphere. This review focuses on breakthroughs in understanding the process involving seasonal carbon dioxide phase changes that have occurred as a result of observations by Mars Global Surveyor. ?? 2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

  1. Photoelectrochemical reduction of carbon dioxide using Ge doped GaN nanowire photoanodes

    Directory of Open Access Journals (Sweden)

    Yichen Wang

    2015-11-01

    Full Text Available We report on the direct conversion of carbon dioxide (CO2 in a photoelectrochemical cell consisting of germanium doped gallium nitride nanowire anode and copper (Cu cathode. Various products including methane (CH4, carbon monoxide (CO, and formic acid (HCOOH were observed under light illumination. A Faradaic efficiency of ∼10% was measured for HCOOH. Furthermore, this photoelectrochemical system showed enhanced stability for 6 h CO2 reduction reaction on low cost, large area Si substrates.

  2. CARBON DIOXIDE REDUCTION SYSTEM.

    Science.gov (United States)

    CARBON DIOXIDE , *SPACE FLIGHT, RESPIRATION, REDUCTION(CHEMISTRY), RESPIRATION, AEROSPACE MEDICINE, ELECTROLYSIS, INSTRUMENTATION, ELECTROLYTES, VOLTAGE, MANNED, YTTRIUM COMPOUNDS, ZIRCONIUM COMPOUNDS, NICKEL.

  3. Assessing atmospheric nitrogen deposition to natural and semi-natural ecosystems – experience from Danish studies using the DAMOS system

    DEFF Research Database (Denmark)

    Hertel, Ole; Geels, Camilla; Frohn, Lise

    2013-01-01

    and ammonium (reaction products of nitrogen oxides and ammonia), but also dry deposition of other reactive nitrogen compounds (mainly nitrogen oxides in the form of gas phase nitric acid and nitrogen dioxide). In Denmark's environmental management of the sensitive terrestrial ecosystems modelling tools...

  4. Comparison of the killing effects between nitrogen-doped and pure TiO2 on HeLa cells with visible light irradiation

    Science.gov (United States)

    Li, Zheng; Pan, Xiaobo; Wang, Tianlong; Wang, Pei-Nan; Chen, Ji-Yao; Mi, Lan

    2013-02-01

    The killing effect of nitrogen-doped titanium dioxide (N-TiO2) nanoparticles on human cervical carcinoma (HeLa) cells by visible light photodynamic therapy (PDT) was higher than that of TiO2 nanoparticles. To study the mechanism of the killing effect, the reactive oxygen species produced by the visible-light-activated N-TiO2 and pure-TiO2 were evaluated and compared. The changes of the cellular parameters, such as the mitochondrial membrane potential (MMP), intracellular Ca2+, and nitrogen monoxide (NO) concentrations after PDT were measured and compared for N-TiO2- and TiO2-treated HeLa cells. The N-TiO2 resulted in more loss of MMP and higher increase of Ca2+ and NO in HeLa cells than pure TiO2. The cell morphology changes with time were also examined by a confocal microscope. The cells incubated with N-TiO2 exhibited serious distortion and membrane breakage at 60 min after the PDT.

  5. An interesting cause of pulmonary emboli: Acute carbon monoxide poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Sevinc, A.; Savli, H.; Atmaca, H. [Gaziantep University, Gaziantep (Turkey). School of Medicine

    2005-07-01

    Carbon monoxide poisoning, a public health problem of considerable significance, is a relatively frequent event today, resulting in thousands of hospitalizations annually. A 70-year-old lady was seen in the emergency department with a provisional diagnosis of carbon monoxide poisoning. The previous night, she slept in a tightly closed room heated with coal ember. She was found unconscious in the morning with poor ventilation. She had a rare presentation of popliteal vein thrombosis, pulmonary emboli, and possible tissue necrosis with carbon monoxide poisoning. Oxygen treatment with low-molecular-weight heparin (nadroparine) and warfarin therapy resulted in an improvement in both popliteal and pulmonary circulations. In conclusion, the presence of pulmonary emboli should be sought in patients with carbon monoxide poisoning.

  6. US EPA Region 9 carbon monoxide designated areas

    Data.gov (United States)

    U.S. Environmental Protection Agency — Polygon Feature class of Nonattainment Areas for Carbon Monoxide. Nonattainment areas are geographic areas which have not met National Ambient Air Quality Standards...

  7. Carbon monoxide poisoning in the United Arab Emirates.

    Science.gov (United States)

    Al Kaabi, Juma M; Wheatley, Andrew D; Barss, Peter; Al Shamsi, Mariam; Lababidi, Anis; Mushtaq, Ahmed

    2011-01-01

    Carbon monoxide (CO) poisoning is rare in the Arabian Peninsula and occurs almost exclusively during the winter months. Knowledge and perception of the hazards of carbon monoxide is limited. Migrant workers from warm climates appear particularly at risk. We investigated 46 cases of carbon monoxide poisoning presenting at emergency departments from 2007-2009 of the two main hospitals in Al Ain city, United Arab Emirates. Interviews, hospital records, and administered questionnaires were used to collect the data. Among the 46 cases investigated, 24 (52%) were males. Foreign nationals compromised 80% of the cases and the incidence was 3.1 cases per 100,000 residents per year. Burning charcoal in poorly ventilated residences was the predominant source of the carbon monoxide poisoning. Almost all cases (98%) were admitted during the winter months, most in the early morning hours. Carboxyhaemoglobin (COHb) was significantly increased in cases with loss of consciousness and depressed consciousness. There were no reported fatalities.

  8. Same Exposure, Various Clinical Pictures: The Carbon Monoxide Enigma

    Directory of Open Access Journals (Sweden)

    Musa Salmanoglu

    2013-02-01

    Full Text Available -Children and adolescents exposed to the same source of carbon monoxide have been shown to demonstrate different clinical pictures (1,2. The same condition probably may be extrapolated between children with varying ages and hence lung surface areas. Smaller children will receive larger doses of carbon monoxide, because they have greater lung surface area/body weight ratios and increased minute volumes/weight ratios. As carbon monoxide accumulation is expected to be more significant nearer to the ground, another explanation for varying clinical pictures in poisoning events may be the different level of sleeping positions of the casualties. Herein, we report a cluster poisoning of carbon monoxide affecting 5 children from the same family at the same time but in different clinical pictures. [TAF Prev Med Bull 2013; 12(1.000: 118-118

  9. Characteristics of autoignited laminar lifted flames in heated coflow jets of carbon monoxide/hydrogen mixtures

    KAUST Repository

    Choi, Byungchul

    2012-06-01

    The characteristics of autoignited lifted flames in laminar jets of carbon monoxide/hydrogen fuels have been investigated experimentally in heated coflow air. In result, as the jet velocity increased, the blowoff was directly occurred from the nozzle-attached flame without experiencing a stabilized lifted flame, in the non-autoignited regime. In the autoignited regime, the autoignited lifted flame of carbon monoxide diluted by nitrogen was affected by the water vapor content in the compressed air oxidizer, as evidenced by the variation of the ignition delay time estimated by numerical calculation. In particular, in the autoignition regime at low temperatures with added hydrogen, the liftoff height of the autoignited lifted flames decreased and then increased as the jet velocity increased. Based on the mechanism in which the autoignited laminar lifted flame is stabilized by ignition delay time, the liftoff height can be influenced not only by the heat loss, but also by the preferential diffusion between momentum and mass diffusion in fuel jets during the autoignition process. © 2012 The Korean Society of Mechanical Engineers.

  10. Carbon Dioxide and Climate.

    Science.gov (United States)

    Brewer, Peter G.

    1978-01-01

    The amount of carbon dioxide in the atmosphere is increasing at a rate that could cause significant warming of the Earth's climate in the not too distant future. Oceanographers are studying the role of the ocean as a source of carbon dioxide and as a sink for the gas. (Author/BB)

  11. Carbon Dioxide Fountain

    Science.gov (United States)

    Kang, Seong-Joo; Ryu, Eun-Hee

    2007-01-01

    This article presents the development of a carbon dioxide fountain. The advantages of the carbon dioxide fountain are that it is odorless and uses consumer chemicals. This experiment also is a nice visual experiment that allows students to see evidence of a gaseous reagent being consumed when a pressure sensor is available. (Contains 3 figures.)…

  12. Carbon monoxide exposure in blast furnace workers.

    Science.gov (United States)

    Lewis, S; Mason, C; Srna, J

    1992-09-01

    This study investigated the occupational exposure to carbon monoxide (CO) of a group of blast furnace workers from an integrated steelworks, compared to a control group having no significant occupational CO exposure from other areas in the same works. The study was undertaken in 1984 at Port Kembla, New South Wales. Carboxyhaemoglobin (COHb) levels before and after an eight-hour work shift were measured in 98 male steelworkers: 52 from two CO-exposed iron blast furnaces and 46 controls from production areas in the same steelworks. The sample was stratified by smoking habits. Environmental air CO levels had been found to be consistently higher on one furnace than on the other. Absorption of CO from the working environment occurred in workers on the blast furnace with higher CO levels, regardless of smoking habits. On this blast furnace, some readings of COHb levels after a workshift in nonsmokers approached the proposed Australian occupational limit of 5 per cent COHb saturation. Overall, workers with the highest occupational exposure who smoked most heavily had the highest absorption of CO over a work shift. Biological monitoring gives an accurate measure of individual worker 'dose' of CO from all sources. Both environmental monitoring and biological monitoring need to be included as part of a program for controlling occupational CO exposure.

  13. Carbon Monoxide: An Essential Signalling Molecule

    Science.gov (United States)

    Mann, Brian E.

    Carbon monoxide (CO), like nitric oxide (NO), is an essential signalling molecule in humans. It is active in the cardiovascular system as a vasodilator. In addition, CO possesses anti-inflammatory, anti-apoptotic and anti-proliferative properties and protects tissues from hypoxia and reperfusion injury. Some of its applications in animal models include suppression of organ graft rejection and safeguarding the heart during reperfusion after cardiopulmonary bypass surgery. CO also suppresses arteriosclerotic lesions following angioplasty, reverses established pulmonary hypertension and mitigates the development of post-operative ileus in the murine small intestine and the development of cerebral malaria in mice as well as graft-induced intimal hyperplasia in pigs. There have been several clinical trials using air-CO mixtures for the treatment of lung-, heart-, kidney- and abdominal-related diseases. This review examines the research involving the development of classes of compounds (with particular emphasis on metal carbonyls) that release CO, which could be used in clinically relevant conditions. The review is drawn not only from published papers in the chemical literature but also from the extensive biological literature and patents on CO-releasing molecules (CO-RMs).

  14. First-Principles Investigations on Europium Monoxide

    KAUST Repository

    Wang, Hao

    2011-05-01

    Europium monoxide is both an insulator and a Heisenberg ferromagnet (Tc=69 K). In the present thesis, the author has investigated the electronic structure of different types of EuO by density functional theory. The on-site Coulomb interaction of the localized Eu 4f and 5d electrons, which is wrongly treated in the standard generalized gradient approximation method, is found to be crucial to obtain the correct insulating ground state as observed in experiments. Our results show that the ferromagnetism is stable under pressure, both hydrostatic and uniaxial. For both types of pressure an insulator-metal transition is demonstrated. Moreover, the experimentally observed insulator-metal transition in oxygen deficient and gadolinium-doped EuO is reproduced in our calculations for impurity concentrations of 6.25% and 25%. Furthermore, a 10- layer EuO thin film is theoretically predicted to be an insulator with a narrow band gap of around 0.08 eV, while the Si/EuO interface shows metallic properties with the Si and O 2p as well as Eu 5d bands crossing the Fermi level.

  15. Chlorine Monoxide in the Antarctic Spring Stratosphere.

    Science.gov (United States)

    Jaramillo-Ayerbe, Mauricio

    1988-06-01

    A series of observations of stratospheric chlorine monoxide (ClO) were carried out during the austral springs of 1986 and 1987 in McMurdo Station, Antarctica, as part of two experimental campaigns sent to investigate the seasonal decrease in ozone over the antarctic continent (the ozone "hole"). Measurements of the vertical distribution of ClO were obtained by high resolution ground-based emission spectroscopy at 278 GHz, using the Stony Brook mm-wave receiver. They show the presence of an anomalous layer of lower stratospheric ClO which is not observed at other latitudes. This anomalous layer is centered at ~20 km altitude and exhibits a pronounced diurnal variation, reaching a maximum at midday and disappearing at night. During the period of Sep. 20-24, 1987, the lower-stratospheric ClO had a maximum volume mixing ratio of 1.8_sp{+0cdot5}{ -0cdot9} ppbv. A normal ClO layer centered at ~36 km was also observed, with concentrations and diurnal behavior similar to those seen in tropical latitudes. These findings are evidence of anomalous chlorine chemistry taking place in the lower stratosphere during the antarctic spring, and indicate that increasing anthropogenic chlorine is a prime causative agent in the formation of the ozone hole.

  16. Assessment of carbon monoxide values in smokers: a comparison of carbon monoxide in expired air and carboxyhaemoglobin in arterial blood

    DEFF Research Database (Denmark)

    Andersson, Mette F; Møller, Ann M

    2010-01-01

    Smoking increases perioperative complications. Carbon monoxide concentrations can estimate patients' smoking status and might be relevant in preoperative risk assessment. In smokers, we compared measurements of carbon monoxide in expired air (COexp) with measurements of carboxyhaemoglobin (COHb) ......) in arterial blood. The objectives were to determine the level of correlation and to determine whether the methods showed agreement and evaluate them as diagnostic tests in discriminating between heavy and light smokers....

  17. Modeling of carbon monoxide oxidation kinetics over NASA carbon dioxide laser catalysts

    Science.gov (United States)

    Herz, Richard K.

    1989-01-01

    The recombination of CO and O2 formed by the dissociation of CO2 in a sealed CO2 laser discharge zone is examined. Conventional base-metal-oxide catalysts and conventional noble-metal catalysts are not effective in recombining the low O2/CO ratio at the low temperatures used by the lasers. The use of Pt/SnO2 as the noble-metal reducible-oxide (NMRO), or other related materials from Group VIIIA and IB and SnO2 interact synergistically to produce a catalytic activity that is substantially higher than either componet separately. The Pt/SnO2 and Pd/SnO2 were reported to have significant reaction rates at temperatures as low as -27 C, conditions under which conventional catalysts are inactive. The gas temperature range of lasers is 0 + or - 40 C. There are three general ways in which the NMRO composite materials can interact synergistically: one component altering the properties of another component; the two components each providing independent catalytic functions in a complex reaction mechanism; and the formation of catalytic sites through the combination of two components at the atomic level. All three of these interactions may be important in low temperature CO oxidation over NMRO catalysts. The effect of the noble metal on the oxide is discussed first, followed by the effect of the oxide on the noble metal, the interaction of the noble metal and oxide to form catalytic sites, and the possible ways in which the CO oxidation reaction is catalyzed by the NMRO materials.

  18. Photocatalytic degradation of organic compounds in ultrapure water by using nitrogen-doped titanium dioxide%氮掺杂二氧化钛光催化降解超纯净水中有机化合物

    Institute of Scientific and Technical Information of China (English)

    孙婷; 陈凯

    2012-01-01

    UV unit is one of the important operation units in the ultrapure water production. Due to high energy consumption of usual UV unit, searching a high-efficient energy-saving UV unit becomes one of the hottest research topics nowadays. The TiO2 film was successfully prepared by sol-gel method with tetrabutyl titanate as precursor and ethanol as solvent. The nitrogen-doped TiO2 film was attained by calcinations of TiO2 film through ammoniation at elevated temperature. The photocatalytic activities of synthesized catalysts were examined using ethylene glycol, isopropyl alcohol and urea as model organic contaminants in ultrapure water. The experimental results demonstrate that under the same ultraviolet light radiation, the catalytic effect of nitrogen-doped TiO2 is much better than that of TiO2, and the same oxidation effect can be achieved by either using 185 nm UV lamp only or using the combination of nitrogen-doped TiO2 with 254 nm UV lamp. The application of such technology in ultrapure water purification can greatly reduce the energy consumption and cost of production.%UV氧化单元是生产超纯水过程中的一个重要组成部分.然而,常规UV氧化能耗大,寻求高效节能的UV氧化方式已成为当今超纯净水净化研究热点之一.文中采用溶胶凝胶法,以钛酸四丁酯为钛前驱体,乙醇为溶剂,成功制备了TiO2薄膜.TiO2薄膜在加温条件下氨化制得了含氮TiO2.实验通过光催化降解超纯净水中乙二醇、异丙醇及尿素,考查了合成催化剂的性能.实验表明:在相同紫外光源条件下,掺氮TiO2的催化效果明显优于TiO2的催化效果.将掺氮TiO2与254 nm UV灯结合使用能达到与仅使用185 nmUV灯的同样的氧化效果,将此技术应用于超纯净水处理将会大大降低清洁水净化能量消耗及生产成本.

  19. Game Changing Development Program - Next Generation Life Support Project: Oxygen Recovery From Carbon Dioxide Using Ion Exchange Membrane Electrolysis Technology

    Science.gov (United States)

    Burke, Kenneth A.; Jiao, Feng

    2016-01-01

    This report summarizes the Phase I research and development work performed during the March 13, 2015 to July 13, 2016 period. The proposal for this work was submitted in response to NASA Research Announcement NNH14ZOA001N, "Space Technology Research, Development, Demonstration, and Infusion 2014 (SpaceTech-REDDI-2014)," Appendix 14GCD-C2 "Game Changing Development Program, Advanced Oxygen Recovery for Spacecraft Life Support Systems Appendix" The Task Agreement for this Phase I work is Document Control Number: GCDP-02-TA-15015. The objective of the Phase I project was to demonstrate in laboratories two Engineering Development Units (EDU) that perform critical functions of the low temperature carbon dioxide electrolysis and the catalytic conversion of carbon monoxide into carbon and carbon dioxide. The low temperature carbon dioxide electrolysis EDU was built by the University of Delaware with Dr. Feng Jiao as the principal investigator in charge of this EDU development (under NASA Contract NNC15CA04C). The carbon monoxide catalytic conversion EDU was built by the NASA Glenn Research Center with Kenneth Burke as the principal investigator and overall project leader for the development of both EDUs. Both EDUs were successfully developed and demonstrated the critical functions for each process. The carbon dioxide electrolysis EDU was delivered to the NASA Johnson Space Center and the carbon monoxide catalytic conversion EDU was delivered to the NASA Marshall Spaceflight Center.

  20. 76 FR 68638 - Approval and Promulgation of Air Quality Implementation Plans; Virginia; Revision to Nitrogen...

    Science.gov (United States)

    2011-11-07

    ... Nitrogen Oxides Budget Trading Program AGENCY: Environmental Protection Agency (EPA). ACTION: Direct final... Implementation Plan (SIP). The revision pertains to regulatory language in its nitrogen oxides (NO X ) Budget..., Nitrogen dioxide, Ozone, Sulfur oxides. Dated: October 25, 2011. W.C. Early, Acting Regional...

  1. The effects of acid rain on nitrogen fixation in Western Washington coniferous forests

    Science.gov (United States)

    Robert Denison; Bruce Caldwell; Bernard Bormann; Lindell Eldred; Cynthia Swanberg; Steven Anderson

    1976-01-01

    We investigated both the current status of nitrogen fixation in Western Washington forests, and the potential effects of acid rain on this vital process. Even the low concentrations of sulfur dioxide presently found in the Northwest are thought to have an adverse effect on nitrogen fixation by limiting the distribution of the epiphytic nitrogen-fixing lichen, ...

  2. Governing processes for reactive nitrogen compounds in the atmosphere in relation to ecosystem, climatic and human health impacts

    Directory of Open Access Journals (Sweden)

    O. Hertel

    2012-07-01

    Full Text Available Reactive nitrogen (Nr compounds have different fates in the atmosphere due to differences in governing processes of physical transport, deposition and chemical transformation. Nr compounds addressed here include reduced nitrogen (NHx: ammonia (NH3 and its reaction product ammonium (NH4+, oxidized nitrogen (NOy: nitrogen monoxide (NO + nitrogen dioxide (NO2 and their reaction products as well as organic nitrogen compounds (organic N. Pollution abatement strategies need to take into account these differences in the governing processes of these compounds when assessing their impact on ecosystem services, biodiversity, human health and climate. NOx (NO + NO2 emitted from traffic affects human health in urban areas where the presence of buildings increases the residence time in streets. In urban areas this leads to enhanced exposure of the population to NOx concentrations. NOx emissions have little impact on nearby ecosystems because of the small dry deposition rates of NOx. These compounds need to be converted into nitric acid (HNO3 before removal through deposition is efficient. HNO3 sticks quickly to any surface and is thereby either dry deposited or incorporated into aerosols as nitrate (NO3. In contrast to NOx compounds, NH3 has potentially high impacts on ecosystems near the main agricultural sources of NH3 because of its large ground-level concentrations along with large dry deposition rates. Aerosol phase NH4+ and NO3 contribute significantly to background PM2.5 and PM10 (mass of aerosols with a diameter of less than 2.5 and 10 μm, respectively with an impact on radiation balance as well as potentially on human health. Little is known quantitatively and

  3. High temperature thermodynamics and vaporization of stoichiometric titanium monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Sheldon, R.I.; Gilles, P.W.

    1976-08-17

    Three vaporization experiments were performed on samples of nearly stoichiometric titanium monoxide. Two experiments were constant temperature experiments (1806/sup 0/K) designed to measure the equilibrium vapor pressures of Ti(g) and TiO(g). In one experiment titanium monoxide was vaporized from a tungsten Knudsen effusion cell; the vapor was collected on a water cooled quartz cap surrounding the cell; and the total amount of titanium deposited on the cap was analyzed colorimetrically. In the second constant temperature experiment (1806/sup 0/K) the vapor composition in equilibrium with nearly stoichiometric titanium monoxide was measured mass spectrometrically. The mass spectrometer results were used to apportion the total titanium collected in the first experiment to Ti(g) and TiO(g). In the third experiment the temperature dependence of the ions Ti/sup +/(48) and TiO(64) was measured spectrometrically. The results obtained in this work are compared with published thermodynamic properties of the titanium oxygen system, and indicate the standard free energy of formation of titanium monoxide obtained from the earliest calorimetric measurements yielded a result not negative enough and also oxygen pressures obtained by emf measurements for stoichiometric titanium monoxide at 1806/sup 0/K are high by a factor of 42.6. The present results are in good agreement with the thermodynamic properties reported in recently issued pages of the JANAF Thermochemical Tables.

  4. Nitrogen deposition may enhance soil carbon storage via change of soil respiration dynamic during a spring freeze-thaw cycle period

    OpenAIRE

    Guoyong Yan; Yajuan Xing; Lijian Xu; Jianyu Wang; Wei Meng; Qinggui Wang; Jinghua Yu; Zhi Zhang; Zhidong Wang; Siling Jiang; Boqi Liu; Shijie Han

    2016-01-01

    As crucial terrestrial ecosystems, temperate forests play an important role in global soil carbon dioxide flux, and this process can be sensitive to atmospheric nitrogen deposition. It is often reported that the nitrogen addition induces a change in soil carbon dioxide emission in growing season. However, the important effects of interactions between nitrogen deposition and the freeze-thaw-cycle have never been investigated. Here we show nitrogen deposition delays spikes of soil respiration a...

  5. [Massive poisoning with carbon monoxide: an update from a case].

    Science.gov (United States)

    Díaz, Mariano; Crapanzano, Gabriel; Cabrerizo, Silvia; Aichele, Cristina; Deurtiaga, Alejandra; Vallejos, Yamila

    2017-02-01

    Carbon monoxide is known as the "silent murderer" because it is a colorless and odorless gas. According to these characteristics, toxicity goes unnoticed which makes the diagnosis difficult. In most cases, the cold periods and group poisoning make suspect its presence because inappropriate heat both in home or public environments. Our goal is to inform about a mass carbon monoxide poisoning in a children's parties room using a combustion source installed, not for the purpose of heating, but as a supply of light (generator), emphasizing that it can occur in any time of the year.

  6. Structural and magnetic properties of mechanochemically synthesized nanocrystalline titanium monoxide

    Directory of Open Access Journals (Sweden)

    Barudžija Tanja

    2012-01-01

    Full Text Available Nano-sized titanium monoxide (TiO powder was prepared by mechanochemical synthesis. A mixture of commercial Ti and TiO2 (rutile powders with the molar ratio of 1:1 was milled in a planetary ball mill for 5, 10, 20, 30 and 60 min under argon atmosphere. The final single-phase titanium monoxide sample was characterized by X-ray diffraction (XRD, magnetic measurements using a superconducting quantum interference device magnetometer (SQUID and thermogravimetric analysis (TGA. The temperature dependency of the magnetic susceptibility is characterized by significant contribution of Pauli paramagnetism due to conduction electrons.

  7. Ozone, Air Quality, and Asthma (For Parents)

    Science.gov (United States)

    ... Development Infections Diseases & Conditions Pregnancy & Baby Nutrition & Fitness Emotions & Behavior School & Family Life First Aid & Safety Doctors & ... carbon monoxide sulfur dioxide nitrogen dioxide Using a color-coded system, the Air Quality Index indicates when ...

  8. Effects of twice-ambient carbon dioxide and nitrogen amendment on biomass, nutrient contents and carbon costs of Norway spruce seedlings as influenced by mycorrhization with Piloderma croceum and Tomentellopsis submollis.

    Science.gov (United States)

    Weigt, Rosemarie Barbara; Raidl, Stefan; Verma, Rita; Rodenkirchen, Hermann; Göttlein, Axel; Agerer, Reinhard

    2011-07-01

    Elevated tropospheric CO(2) concentrations may increase plant carbon fixation. In ectomycorrhizal trees, a considerable portion of the synthesized carbohydrates can be used to support the mutualistic fungal root partner which in turn can benefit the tree by increased nutrient supply. In this study, Norway spruce seedlings were inoculated with either Piloderma croceum (medium distance "fringe" exploration type) or Tomentellopsis submollis (medium distance "smooth" exploration type). We studied the impact of either species regarding fungal biomass production, seedling biomass, nutrient status and nutrient use efficiency in rhizotrons under ambient and twice-ambient CO(2) concentrations. A subset was amended with ammonium nitrate to prevent nitrogen imbalances expected under growth promotion by elevated CO(2). The two fungal species exhibited considerably different influences on growth, biomass allocation as well as nutrient uptake of spruce seedlings. P. croceum increased nutrient supply and promoted plant growth more strongly than T. submollis despite considerably higher carbon costs. In contrast, seedlings with T. submollis showed higher nutrient use efficiency, i.e. produced plant biomass per received unit of nutrient, particularly for P, K and Mg, thereby promoting shoot growth and reducing the root/shoot ratio. Under the given low soil nutrient availability, P. croceum proved to be a more favourable fungal partner for seedling development than T. submollis. Additionally, plant internal allocation of nutrients was differently influenced by the two ECM fungal species, particularly evident for P in shoots and for Ca in roots. Despite slightly increased ECM length and biomass production, neither of the two species had increased its capacity of nutrient uptake in proportion to the rise of CO(2). This lead to imbalances in nutritional status with reduced nutrient concentrations, particularly in seedlings with P. croceum. The beneficial effect of P. croceum thus

  9. Carbon Monoxide Accumulation in the Extravehicular Mobility Unit

    Science.gov (United States)

    Conkin, J.; Norcrosss, J. R.; Alexander, D. J.; Sanders, R. W.; Makowski, M. S.

    2016-01-01

    Introduction: Life support technology in large closed systems like submarines and space stations catalyzes carbon monoxide (CO) to carbon dioxide, which is easily removed. However, in a small system like the Extravehicular Mobility Unit (EMU), spacesuit, CO from exogenous (contaminated oxygen (O (sub 2) supply) and endogenous (human metabolism) sources will accumulate in the free suit volume. The free volume becomes a sink for CO that is rebreathed by the astronaut. The accumulation through time depends on many variables: the amount absorbed by the astronaut, the amount produced by the astronaut (between 0.28 and 0.34 ?moles per hour per kilogram)[1], the amount that enters the suit from contaminated O (sub 2), the amount removed through suit leak, the free volume of the suit, and the O (sub 2) partial pressure[2], just to list a few. Contamination of the EMU O (sub 2) supply with no greater than 1 part per million CO was the motivation for empirical measurements from CO pulse oximetry (SpCO) as well as mathematical modeling of the EMU as a rebreather for CO. Methods: We developed a first-order differential mixing equation as well as an iterative method to compute CO accumulation in the EMU. Pre-post measurements of SpCO (Rad-57, Masimo Corporation) from EMU ground training and on-orbit extravehicular activities (EVAs) were collected. Results: Initial modeling without consideration of the astronaut as a sink but only the source of CO showed that after 8 hours breathing 100 percent O (sub 2) with a 10 milliliter per minute (760 millimeters Hg at 21 degrees Centigrade standard) suit leak, an endogenous production rate of 0.23 moles per hour per kilogram for a 70 kilogram person with 42 liters (1.5 cubic feet) free suit volume resulted in a peak CO partial pressure (pCO) of 0.047 millimeters Hg at 4.3 pounds per square inch absolute (222 millimeters Hg). Preliminary results based on a 2008 model[3] with consideration of the astronaut as a sink and source of CO

  10. 不同形貌 N-TiO 2的水热合成及其光催化性能研究%Studies on hydrothermal synthesis of nitrogen-doped titanium dioxide with different morphologies and photocatalytic activities

    Institute of Scientific and Technical Information of China (English)

    周珺; 郑玉婴

    2015-01-01

    Nitrogen-doped titanium dioxide (N-TiO 2 )nanopowders were prepared by hydrothermal synthesis in H 2 SO 4 ,HCl,HNO 3 using the titanium nitride (TiN)as both titanium resource and nitrogen resource.Effects of solvent medium and hydrothermal temperature on the crystalline type,morphology,size and the photocata-lytic activities of the product was investigated.The SEM,XRD result shows that granular anatase TiO 2 was ob-tained in H 2 SO 4 ,while rod-like rutile TiO 2 could be obtained in HCl and HNO 3 ,the crystalline size was as fol-lows:d (HCl)>d (HNO 3 )>d (H 2 SO 4 ),it largens with increasing hydrothermal temperature in the same sol-vent medium.Nitrogen atoms are doped into TiO 2 lattice,form a new bond of O—Ti—N resulting in an in-crease of the lattice distance,which are confirmed by XPS,HRTEM.The narrow of band-gap and the visible-light response are due to nitrogen doping,which are shown by UV-Vis spectra analysis.The experiments of photodegradation of methyl orange show that,the photocatalytic activities was as follows:η(H 2 SO 4 )>η(HNO 3 )>η(HCl),it lessens with increasing hydrothermal temperature in the same solvent medium.%以 TiN 为钛源和氮源,采用水热法分别以H 2 SO 4、HCl、HNO 3为介质合成了 N-TiO 2纳米粉末,研究了介质及水热反应温度对 N-TiO 2晶型、形貌、粒径及光催化性能的影响。 SEM、XRD 表明, H 2 SO 4为介质得到粒状锐钛矿 N-TiO 2,HCl、HNO 3为介质得到棒状金红石 N-TiO 2,粒径 d (HCl)>d (HNO 3)>d (H 2 SO 4),相同介质中,粒径随反应温度的升高而增大。 XPS、HRTEM 表明,N 元素以O—Ti—N 键形式掺杂,使得 TiO 2晶格间距变大。 UV-Vis 表明,N 掺杂降低了 TiO 2的禁带宽度,感光范围拓展到可见光区。可见光催化降解实验表明,催化效率η(H 2 SO 4)>η(HNO 3)>η(HCl),相同介质中,光催化效率随反应温度的升高而降低。

  11. The Effects of Low Level Prenatal Carbon Monoxide on Neocortical Development

    Science.gov (United States)

    2010-06-02

    378.1958). Ginsberg MD, Myers RE (Fetal brain damage following maternal carbon monoxide intoxication: an experimental study. Acta obstetricia et...monoxide production and blood loss at delivery. Acta obstetricia et gynecologica Scandinavica 48:362-370.1969). Longo LD (Carbon monoxide in the

  12. Deep Conversion of Carbon Monoxide to Hydrogen and Formation of Acetate by the Anaerobic Thermophile Carboxydothermus hydrogenoformans

    Directory of Open Access Journals (Sweden)

    Anne M. Henstra

    2011-01-01

    Full Text Available Carboxydothermus hydrogenoformans is a thermophilic strictly anaerobic bacterium that catalyses the water gas shift reaction, the conversion of carbon monoxide with water to molecular hydrogen and carbon dioxide. The thermodynamically favorable growth temperature, compared to existing industrial catalytic processes, makes this organism an interesting alternative for production of cheap hydrogen gas suitable to fuel CO-sensitive fuel cells in a future hydrogen economy, provided sufficiently low levels of CO are reached. Here we study CO conversion and final CO levels in cultures of C. hydrogenoformans grown in batch cultures that were started with a 100% CO gas phase with and without removal of formed CO2. Final CO levels were 117 ppm without CO2 removal and below 2 ppm with CO2 removal. The Gibbs free energy change calculated with measured end concentrations and the detection of acetate suggest that C. hydrogenoformans shifted from a hydrogenogenic to an acetogenic metabolism.

  13. Fourier Transform Spectrometer observations of solar carbon monoxide. I - The fundamental and first overtone bands in the quiet sun

    Science.gov (United States)

    Ayres, T. R.; Testerman, L.

    1981-01-01

    Measurements of the 2200/cm fundamental and 4300/cm first overtone vibration-rotation band systems of solar carbon monoxide, were obtained with the Fourier Transform Spectrometer of the McMath telescope at Kitt Peak. The overtone measurements were taken at the east, north, and west heliocentric limbs, and at disk center. Observations of the strong fundamental bands were obtained at disk center and near the north limb. The low core brightness temperatures of the strongest fundamental carbon monoxide lines near the limb, reported previously by Noyes (1972) and Hall (1974), are confirmed. The possibility that thermal inhomogeneities might be responsible for the unusual behavior of the fundamental carbon dioxide lines have been examined. The somewhat discordant behavior of the fundamental lines at disk center compared with the north limb seems to favor a limb shadowing effect. The first overtone limb equivalent widths and the best-fit thermal and microvelocity models indicate a solar carbon abundance of 0.004 (on the scale with A sub H = 1) for an oxygen-to-carbon abundance ratio of 2.

  14. Effects of Air Polution on Human Exercise Performance,

    Science.gov (United States)

    1988-02-01

    Interaction of various acids and salts. The most commonly studied aerosols are ammonium sulfate, ammonium bisulfate and amnium nitrate. These compounds are eye...FIELD IGROUP SUB-GROUP ozone, nitrogen dioxide, peroxyacetyl nitrate, aerosols, sulfur dioxide, carbon monoxide ’Itrength, performance. 19. ABSTRC...ozone, peroxyacetyl nitrate, aerosols, sulfur dioxide, and nitrogen * dioxide. Only carb,:n monoxide has been show to reduce 2xercise performance

  15. Carbon Monoxide Poisoning - Multiple Languages: MedlinePlus

    Science.gov (United States)

    ... sharing features on this page, please enable JavaScript. Amharic (amarunya) Arabic (العربية) Chinese - Traditional (繁體中文) French (français) ... Kiswahili) Tagalog (Tagalog) Tigrinya (tigrinya) Vietnamese (Tiếng Việt) Amharic (amarunya) Prevention Guidelines: You Can Prevent Carbon Monoxide ...

  16. Pathways and bioenergetics of anaerobic carbon monoxide fermentation

    NARCIS (Netherlands)

    Diender, Martijn; Stams, Fons; Machado de Sousa, Diana

    2015-01-01

    Carbon monoxide can act as a substrate for different modes of fermentative anaerobic metabolism. The trait of utilizing CO is spread among a diverse group of microorganisms, including members of bacteria as well as archaea. Over the last decade this metabolism has gained interest due to the poten

  17. UV-induced carbon monoxide emission from living vegetation

    DEFF Research Database (Denmark)

    Bruhn, Dan; Albert, Kristian Rost; Mikkelsen, Teis Nørgaard

    2013-01-01

    The global burden of carbon monoxide (CO) is rather uncertain. In this paper we address the potential for UV-induced CO emission by living terrestrial vegetation surfaces. Real-time measurements of CO concentrations were made with a cavity enhanced laser spectrometer connected in closed loop...

  18. Study on Response Time of SPE Carbon Monoxide Sensor

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The influence of structural design and the parameters of the working electrode on the response time of a solid polymer electrolyte (SPE) carbon monoxide sensor has been studied. Results show that the response time is mainly determined by the RC time constant of the catalyst layer and also related with the working electrode potential.

  19. Hydrogen, carbon monoxide, and methane in the marine environment

    OpenAIRE

    Bulliste