WorldWideScience

Sample records for oxide aerosol tests

  1. Sodium oxide and uranium oxide aerosol experiments: NSPP Tests 106-108 and Tests 204-207, data record report

    Energy Technology Data Exchange (ETDEWEB)

    Adams, R.E.; Kress, T.S.; Tobias, M.L.

    1981-03-01

    This data record report describes three sodium oxide aerosol tests and four uranium oxide aerosol tests conducted in the Nuclear Safety Pilot Plant project at Oak Ridge National Laboratory. The goal of this project is to establish the validity (or level of conservatism) of the aerosol behavioral code, HAARM-3, and follow-on codes under development at the Battelle Columbus Laboratories for the US Nuclear Regulatory Commission. Descriptions of the seven tests with tables and graphs summarizing the results are included. 92 figs.

  2. Initiation of depleted uranium oxide and spent fuel testing for the spent fuel sabotage aerosol ratio program

    Energy Technology Data Exchange (ETDEWEB)

    Molecke, M.A.; Gregson, M.W.; Sorenson, K.B. [Sandia National Labs. (United States); Billone, M.C.; Tsai, H. [Argonne National Lab. (United States); Koch, W.; Nolte, O. [Fraunhofer Inst. fuer Toxikologie und Experimentelle Medizin (Germany); Pretzsch, G.; Lange, F. [Gesellschaft fuer Anlagen- und Reaktorsicherheit (Germany); Autrusson, B.; Loiseau, O. [Inst. de Radioprotection et de Surete Nucleaire (France); Thompson, N.S.; Hibbs, R.S. [U.S. Dept. of Energy (United States); Young, F.I.; Mo, T. [U.S. Nuclear Regulatory Commission (United States)

    2004-07-01

    We provide a detailed overview of an ongoing, multinational test program that is developing aerosol data for some spent fuel sabotage scenarios on spent fuel transport and storage casks. Experiments are being performed to quantify the aerosolized materials plus volatilized fission products generated from actual spent fuel and surrogate material test rods, due to impact by a high energy density device, HEDD. The program participants in the U.S. plus Germany, France, and the U.K., part of the international Working Group for Sabotage Concerns of Transport and Storage Casks, WGSTSC have strongly supported and coordinated this research program. Sandia National Laboratories, SNL, has the lead role for conducting this research program; test program support is provided by both the U.S. Department of Energy and Nuclear Regulatory Commission. WGSTSC partners need this research to better understand potential radiological impacts from sabotage of nuclear material shipments and storage casks, and to support subsequent risk assessments, modeling, and preventative measures. We provide a summary of the overall, multi-phase test design and a description of all explosive containment and aerosol collection test components used. We focus on the recently initiated tests on ''surrogate'' spent fuel, unirradiated depleted uranium oxide, and forthcoming actual spent fuel tests. The depleted uranium oxide test rodlets were prepared by the Institut de Radioprotection et de Surete Nucleaire, in France. These surrogate test rodlets closely match the diameter of the test rodlets of actual spent fuel from the H.B. Robinson reactor (high burnup PWR fuel) and the Surry reactor (lower, medium burnup PWR fuel), generated from U.S. reactors. The characterization of the spent fuels and fabrication into short, pressurized rodlets has been performed by Argonne National Laboratory, for testing at SNL. The ratio of the aerosol and respirable particles released from HEDD-impacted spent

  3. Initiation of depleted uranium oxide and spent fuel testing for the spent fuel sabotage aerosol ratio programme

    International Nuclear Information System (INIS)

    Molecke, M.A.; Gregson, M.W.; Sorenson, K.B.

    2004-01-01

    We provide a detailed overview of an on-going, multinational test programme that is developing aerosol data for some spent fuel sabotage scenarios on spent fuel transport and storage casks. Experiments are being performed to quantify the aerosolised materials plus volatilised fission products generated from actual spent fuel and surrogate material test rods, due to impact by a high-energy/density device. The programme participants in the United States plus Germany, France and the United Kingdom, part of the international Working Group for Sabotage Concerns of Transport and Storage Casks (WGSTSC) have strongly supported and coordinated this research programme. Sandia National Laboratories has the lead role for conducting this research programme; test programme support is provided by both the US Department of Energy and the US Nuclear Regulatory Commission. We provide a summary of the overall, multiphase test design and a description of all explosive containment and aerosol collection test components used. We focus on the recently initiated tests on 'surrogate' spent fuel, unirradiated depleted uranium oxide and forthcoming actual spent fuel tests. We briefly summarise similar results from completed surrogate tests that used non-radioactive, sintered cerium oxide ceramic pellets in test rods. (author)

  4. Sodium oxide aerosol filtration

    Energy Technology Data Exchange (ETDEWEB)

    Duverger de Cuy, G [DSN/SESTR, Centre de Cadarache, Saint-Paul-lez-Durance (France)

    1979-03-01

    In the scope of the sodium aerosol trapping research effort by the CEA/DSN, the retention capacity and yield were measured for very high efficiency fiberglass filters and several types of prefilters (cyclone agglomerator, fabric prefilters, water scrubbers). (author)

  5. Sodium oxide aerosol filtration

    International Nuclear Information System (INIS)

    Duverger de Cuy, G.

    1979-01-01

    In the scope of the sodium aerosol trapping research effort by the CEA/DSN, the retention capacity and yield were measured for very high efficiency fiberglass filters and several types of prefilters (cyclone agglomerator, fabric prefilters, water scrubbers). (author)

  6. Ice-condenser aerosol tests

    International Nuclear Information System (INIS)

    Ligotke, M.W.; Eschbach, E.J.; Winegardner, W.K.

    1991-09-01

    This report presents the results of an experimental investigation of aerosol particle transport and capture using a full-scale height and reduced-scale cross section test facility based on the design of the ice compartment of a pressurized water reactor (PWR) ice-condenser containment system. Results of 38 tests included thermal-hydraulic as well as aerosol particle data. Particle retention in the test section was greatly influenced by thermal-hydraulic and aerosol test parameters. Test-average decontamination factor (DF) ranged between 1.0 and 36 (retentions between ∼0 and 97.2%). The measured test-average particle retentions for tests without and with ice and steam ranged between DF = 1.0 and 2.2 and DF = 2.4 and 36, respectively. In order to apparent importance, parameters that caused particle retention in the test section in the presence of ice were steam mole fraction (SMF), noncondensible gas flow rate (residence time), particle solubility, and inlet particle size. Ice-basket section noncondensible flows greater than 0.1 m 3 /s resulted in stable thermal stratification whereas flows less than 0.1 m 3 /s resulted in thermal behavior termed meandering with frequent temperature crossovers between flow channels. 10 refs., 66 figs., 16 tabs

  7. Special aerosol sources for certification and test of aerosol radiometers

    International Nuclear Information System (INIS)

    Belkina, S.K.; Zalmanzon, Y.E.; Kuznetsov, Y.V.; Rizin, A.I.; Fertman, D.E.

    1991-01-01

    The results are presented of the development and practical application of new radionuclide source types (Special Aerosol Sources (SAS)), that meet the international standard recommendations, which are used for certification and test of aerosol radiometers (monitors) using model aerosols of plutonium-239, strontium-yttrium-90 or uranium of natural isotope composition and certified against Union of Soviet Socialist Republics USSR national radioactive aerosol standard or by means of a reference radiometer. The original technology for source production allows the particular features of sampling to be taken into account as well as geometry and conditions of radionuclides radiation registration in the sample for the given type of radiometer. (author)

  8. Special aerosol sources for certification and test of aerosol radiometers

    Energy Technology Data Exchange (ETDEWEB)

    Belkina, S.K.; Zalmanzon, Y.E.; Kuznetsov, Y.V.; Rizin, A.I.; Fertman, D.E. (Union Research Institute of Instrumentation, Moscow (USSR))

    1991-01-01

    The results are presented of the development and practical application of new radionuclide source types (Special Aerosol Sources (SAS)), that meet the international standard recommendations, which are used for certification and test of aerosol radiometers (monitors) using model aerosols of plutonium-239, strontium-yttrium-90 or uranium of natural isotope composition and certified against Union of Soviet Socialist Republics USSR national radioactive aerosol standard or by means of a reference radiometer. The original technology for source production allows the particular features of sampling to be taken into account as well as geometry and conditions of radionuclides radiation registration in the sample for the given type of radiometer. (author).

  9. Spent fuel sabotage aerosol test program :FY 2005-06 testing and aerosol data summary

    International Nuclear Information System (INIS)

    Gregson, Michael Warren; Brockmann, John E.; Nolte, O.; Loiseau, O.; Koch, W.; Molecke, Martin Alan; Autrusson, Bruno; Pretzsch, Gunter Guido; Billone, M. C.; Lucero, Daniel A.; Burtseva, T.; Brucher, W; Steyskal, Michele D.

    2006-01-01

    This multinational, multi-phase spent fuel sabotage test program is quantifying the aerosol particles produced when the products of a high energy density device (HEDD) interact with and explosively particulate test rodlets that contain pellets of either surrogate materials or actual spent fuel. This program has been underway for several years. This program provides source-term data that are relevant to some sabotage scenarios in relation to spent fuel transport and storage casks, and associated risk assessments. This document focuses on an updated description of the test program and test components for all work and plans made, or revised, primarily during FY 2005 and about the first two-thirds of FY 2006. It also serves as a program status report as of the end of May 2006. We provide details on the significant findings on aerosol results and observations from the recently completed Phase 2 surrogate material tests using cerium oxide ceramic pellets in test rodlets plus non-radioactive fission product dopants. Results include: respirable fractions produced; amounts, nuclide content, and produced particle size distributions and morphology; status on determination of the spent fuel ratio, SFR (the ratio of respirable particles from real spent fuel/respirables from surrogate spent fuel, measured under closely matched test conditions, in a contained test chamber); and, measurements of enhanced volatile fission product species sorption onto respirable particles. We discuss progress and results for the first three, recently performed Phase 3 tests using depleted uranium oxide, DUO 2 , test rodlets. We will also review the status of preparations and the final Phase 4 tests in this program, using short rodlets containing actual spent fuel from U.S. PWR reactors, with both high- and lower-burnup fuel. These data plus testing results and design are tailored to support and guide, follow-on computer modeling of aerosol dispersal hazards and radiological consequence assessments

  10. Intercomparison test of various aerosol measurement techniques

    International Nuclear Information System (INIS)

    Cherdron, W.; Hassa, C.; Jordan, S.

    1984-01-01

    At the suggestion of the CONT group (Containment Loading and Response), which is a subgroup of the Safety Working Group of the Fast Reactor Coordinating Committee, a group of experts undertook a comparison of the techniques of sodium aerosol measurement used in various laboratories in the EC. The following laboratories took part in the exercise: CEN-Mol (Belgium), CEA-Cadarache (France), CEA-Fontenay-aux-Roses (France), KfK-Karlsruhe (Federal Republic of Germany), ENEA-Bologna (Italy), and UKAEA-Winfrith (United Kingdom). The objective of the aerosol measurement workshop was to assess the applicability and reliability of specific aerosol measuring instruments. Measurements performed with equipment from the participating laboratories were evaluated using a standard procedure. This enabled an estimate of the accuracy of the experimental data to be provided for the verification of aerosol codes. Thus these results can be used as input for the physical modelling of aerosol behaviour, and the work reported here is a contribution to the definition of the radioactive source term for severe accidents in LMFBRs. The aerosol experts participating in the exercise agreed to concentrate on the techniques of measuring aerosol particle size distributions. The tests were performed at the FAUNA test facility using the aerosol loop. A sodium spray fire, which provides a continuous aerosol source of variable concentration, was produced under open-loop conditions in this facility. Although the primary objective of the workshop was to determine the particle size distributions of the aerosols, measurements of the sodium mass concentration were also made

  11. The Effect of Aerosol Hygroscopicity and Volatility on Aerosol Optical Properties During Southern Oxidant and Aerosol Study

    Science.gov (United States)

    Khlystov, A.; Grieshop, A. P.; Saha, P.; Subramanian, R.

    2014-12-01

    Secondary organic aerosol (SOA) from biogenic sources can influence optical properties of ambient aerosol by altering its hygroscopicity and contributing to light absorption directly via formation of brown carbon and indirectly by enhancing light absorption by black carbon ("lensing effect"). The magnitude of these effects remains highly uncertain. A set of state-of-the-art instruments was deployed at the SEARCH site near Centerville, AL during the Southern Oxidant and Aerosol Study (SOAS) campaign in summer 2013 to measure the effect of relative humidity and temperature on aerosol size distribution, composition and optical properties. Light scattering and absorption by temperature- and humidity-conditioned aerosols was measured using three photo-acoustic extinctiometers (PAX) at three wavelengths (405 nm, 532 nm, and 870 nm). The sample-conditioning system provided measurements at ambient RH, 10%RH ("dry"), 85%RH ("wet"), and 200 C ("TD"). In parallel to these measurements, a long residence time temperature-stepping thermodenuder (TD) and a variable residence time constant temperature TD in combination with three SMPS systems and an Aerosol Chemical Speciation Monitor (ACSM) were used to assess aerosol volatility and kinetics of aerosol evaporation. We will present results of the on-going analysis of the collected data set. We will show that both temperature and relative humidity have a strong effect on aerosol optical properties. SOA appears to increase aerosol light absorption by about 10%. TD measurements suggest that aerosol equilibrated fairly quickly, within 2 s. Evaporation varied substantially with ambient aerosol loading and composition and meteorology.

  12. Strong impacts on aerosol indirect effects from historical oxidant changes

    Science.gov (United States)

    Hafsahl Karset, Inger Helene; Koren Berntsen, Terje; Storelvmo, Trude; Alterskjær, Kari; Grini, Alf; Olivié, Dirk; Kirkevåg, Alf; Seland, Øyvind; Iversen, Trond; Schulz, Michael

    2018-06-01

    Uncertainties in effective radiative forcings through aerosol-cloud interactions (ERFaci, also called aerosol indirect effects) contribute strongly to the uncertainty in the total preindustrial-to-present-day anthropogenic forcing. Some forcing estimates of the total aerosol indirect effect are so negative that they even offset the greenhouse gas forcing. This study highlights the role of oxidants in modeling of preindustrial-to-present-day aerosol indirect effects. We argue that the aerosol precursor gases should be exposed to oxidants of its era to get a more correct representation of secondary aerosol formation. Our model simulations show that the total aerosol indirect effect changes from -1.32 to -1.07 W m-2 when the precursor gases in the preindustrial simulation are exposed to preindustrial instead of present-day oxidants. This happens because of a brightening of the clouds in the preindustrial simulation, mainly due to large changes in the nitrate radical (NO3). The weaker oxidative power of the preindustrial atmosphere extends the lifetime of the precursor gases, enabling them to be transported higher up in the atmosphere and towards more remote areas where the susceptibility of the cloud albedo to aerosol changes is high. The oxidation changes also shift the importance of different chemical reactions and produce more condensate, thus increasing the size of the aerosols and making it easier for them to activate as cloud condensation nuclei.

  13. Strong impacts on aerosol indirect effects from historical oxidant changes

    Directory of Open Access Journals (Sweden)

    I. H. H. Karset

    2018-06-01

    Full Text Available Uncertainties in effective radiative forcings through aerosol–cloud interactions (ERFaci, also called aerosol indirect effects contribute strongly to the uncertainty in the total preindustrial-to-present-day anthropogenic forcing. Some forcing estimates of the total aerosol indirect effect are so negative that they even offset the greenhouse gas forcing. This study highlights the role of oxidants in modeling of preindustrial-to-present-day aerosol indirect effects. We argue that the aerosol precursor gases should be exposed to oxidants of its era to get a more correct representation of secondary aerosol formation. Our model simulations show that the total aerosol indirect effect changes from −1.32 to −1.07 W m−2 when the precursor gases in the preindustrial simulation are exposed to preindustrial instead of present-day oxidants. This happens because of a brightening of the clouds in the preindustrial simulation, mainly due to large changes in the nitrate radical (NO3. The weaker oxidative power of the preindustrial atmosphere extends the lifetime of the precursor gases, enabling them to be transported higher up in the atmosphere and towards more remote areas where the susceptibility of the cloud albedo to aerosol changes is high. The oxidation changes also shift the importance of different chemical reactions and produce more condensate, thus increasing the size of the aerosols and making it easier for them to activate as cloud condensation nuclei.

  14. Adsorption and revaporisation studies on iodine oxide aerosols deposited on containment surface materials in LWR

    Energy Technology Data Exchange (ETDEWEB)

    Tietze, S.; Foreman, M.R.StJ.; Ekberg, C. [Chalmers Univ. of Technology, Goeteborg (Sweden); Kaerkelae, T.; Auvinen, A.; Tapper, U.; Lamminmaeki, S.; Jokiniemi, J. [VTT Technical Research Centre of Finland, Espoo (Finland)

    2012-12-15

    During a hypothetical severe nuclear accident, the radiation field will be very high in the nuclear reactor containment building. As a result gaseous radiolysis products will be formed. Elemental iodine can react in the gaseous phase with ozone to form solid iodine oxide aerosol particles (iodine oxide). Within the AIAS (Adsorption of Iodine oxide Aerosols on Surfaces) project the interactions of iodine oxide (IOx) aerosols with common containment surface materials were investigated. Common surface materials in Swedish and Finnish LWRs are Teknopox Aqua V A paint films and metal surfaces such as Cu, Zn, Al and SS, as well as Pt and Pd surfaces from hydrogen recombiners. Non-radioactive and {sup 131}I labelled iodine oxide aerosols were produced with the EXSI CONT facility from elemental iodine and ozone at VTT Technical Research Centre of Finland. The iodine oxide deposits were analysed with microscopic and spectroscopic measurement techniques to identify the kind of iodine oxide formed and if a chemical conversion on the different surface materials occurs. The revaporisation behaviour of the deposited iodine oxide aerosol particles from the different surface materials was studied under the influence of heat, humidity and gamma irradiation at Chalmers University of Technology, Sweden. Studies on the effects of humidity were performed using the FOMICAG facility, while heat and irradiation experiments were performed in a thermostated heating block and with a gammacell 22 having a dose rate of 14 kGy/h. The revaporisation losses were measured using a HPGe detector. The revaporisated {sup 131}I species from the surfaces were chemically tested for elemental iodine formation. The parameter dominating the degradation of the produced iodine oxide aerosols was humidity. Cu and Zn surfaces were found to react with iodine from the iodine oxide aerosols to form iodides, while no metal iodides were detected for Al and SS samples. Most of the iodine oxide aerosols are assumed to

  15. Adsorption and revaporisation studies on iodine oxide aerosols deposited on containment surface materials in LWR

    International Nuclear Information System (INIS)

    Tietze, S.; Foreman, M.R.StJ.; Ekberg, C.; Kaerkelae, T.; Auvinen, A.; Tapper, U.; Lamminmaeki, S.; Jokiniemi, J.

    2012-12-01

    During a hypothetical severe nuclear accident, the radiation field will be very high in the nuclear reactor containment building. As a result gaseous radiolysis products will be formed. Elemental iodine can react in the gaseous phase with ozone to form solid iodine oxide aerosol particles (iodine oxide). Within the AIAS (Adsorption of Iodine oxide Aerosols on Surfaces) project the interactions of iodine oxide (IOx) aerosols with common containment surface materials were investigated. Common surface materials in Swedish and Finnish LWRs are Teknopox Aqua V A paint films and metal surfaces such as Cu, Zn, Al and SS, as well as Pt and Pd surfaces from hydrogen recombiners. Non-radioactive and 131 I labelled iodine oxide aerosols were produced with the EXSI CONT facility from elemental iodine and ozone at VTT Technical Research Centre of Finland. The iodine oxide deposits were analysed with microscopic and spectroscopic measurement techniques to identify the kind of iodine oxide formed and if a chemical conversion on the different surface materials occurs. The revaporisation behaviour of the deposited iodine oxide aerosol particles from the different surface materials was studied under the influence of heat, humidity and gamma irradiation at Chalmers University of Technology, Sweden. Studies on the effects of humidity were performed using the FOMICAG facility, while heat and irradiation experiments were performed in a thermostated heating block and with a gammacell 22 having a dose rate of 14 kGy/h. The revaporisation losses were measured using a HPGe detector. The revaporisated 131 I species from the surfaces were chemically tested for elemental iodine formation. The parameter dominating the degradation of the produced iodine oxide aerosols was humidity. Cu and Zn surfaces were found to react with iodine from the iodine oxide aerosols to form iodides, while no metal iodides were detected for Al and SS samples. Most of the iodine oxide aerosols are assumed to be

  16. Simulated Field Trials Using an Indoor Aerosol Test Chamber

    National Research Council Canada - National Science Library

    Semler, D. D; Roth, A. P; Semler, K. A; Nolan, P. M

    2004-01-01

    .... In this method, the aerosol chamber control software manipulates circulation fan speeds, chamber vacuum and agent spray times to produce a simulated dynamic cloud within the aerosol test chamber...

  17. Simulated Field Trials Using An Indoor Aerosol Test Chamber

    National Research Council Canada - National Science Library

    Semler, D. D; Roth, A. P; Semler, K. A; Nolan, P. M

    2004-01-01

    .... In this method, the aerosol chamber control software manipulates circulation fan speeds, chamber vacuum and agent spray times to produce a simulated dynamic cloud within the aerosol test chamber...

  18. Aerosol and Photo-Oxidant Processes in the Eastern Mediterranean

    Czech Academy of Sciences Publication Activity Database

    Lazaridis, M.; Spyridaki, A.; Solberg, S.; Smolík, Jiří; Ždímal, Vladimír; Eleftheriadis, K.; Aleksandropoulos, V.; Hov, O.; Georgopoulos, P. G.

    2004-01-01

    Roč. 4, - (2004), s. 5455-5514 ISSN 1680-7367 Grant - others:ENVK2(XE) 1999-00052 Institutional research plan: CEZ:AV0Z4072921 Keywords : aerosol * mesoscale modeling * photo-oxidant processes Subject RIV: CF - Physical ; Theoretical Chemistry

  19. Generation and oxidation of aerosol deposited PdAg nanoparticles

    Science.gov (United States)

    Blomberg, S.; Gustafson, J.; Martin, N. M.; Messing, M. E.; Deppert, K.; Liu, Z.; Chang, R.; Fernandes, V. R.; Borg, A.; Grönbeck, H.; Lundgren, E.

    2013-10-01

    PdAg nanoparticles with a diameter of 10 nm have been generated by an aerosol particle method, and supported on a silica substrate. By using a combination of X-ray Energy Dispersive Spectroscopy and X-ray Photoelectron Spectroscopy it is shown that the size distribution of the particles is narrow and that the two metals form an alloy with a mixture of 75% Pd and 25% Ag. Under oxidizing conditions, Pd is found to segregate to the surface and a thin PdO like oxide is formed similar to the surface oxide previously reported on extended PdAg and pure Pd surfaces.

  20. Spent fuel sabotage aerosol ratio program : FY 2004 test and data summary

    International Nuclear Information System (INIS)

    Brucher, Wenzel; Koch, Wolfgang; Pretzsch, Gunter Guido; Loiseau, Olivier; Mo, Tin; Billone, Michael C.; Autrusson, Bruno A.; Young, F. I.; Coats, Richard Lee; Burtseva, Tatiana; Luna, Robert Earl; Dickey, Roy R.; Sorenson, Ken Bryce; Nolte, Oliver; Thompson, Nancy Slater; Hibbs, Russell S.; Gregson, Michael Warren; Lange, Florentin; Molecke, Martin Alan; Tsai, Han-Chung

    2005-01-01

    This multinational, multi-phase spent fuel sabotage test program is quantifying the aerosol particles produced when the products of a high energy density device (HEDD) interact with and explosively particulate test rodlets that contain pellets of either surrogate materials or actual spent fuel. This program has been underway for several years. This program provides data that are relevant to some sabotage scenarios in relation to spent fuel transport and storage casks, and associated risk assessments. The program also provides significant technical and political benefits in international cooperation. We are quantifying the Spent Fuel Ratio (SFR), the ratio of the aerosol particles released from HEDD-impacted actual spent fuel to the aerosol particles produced from surrogate materials, measured under closely matched test conditions, in a contained test chamber. In addition, we are measuring the amounts, nuclide content, size distribution of the released aerosol materials, and enhanced sorption of volatile fission product nuclides onto specific aerosol particle size fractions. These data are the input for follow-on modeling studies to quantify respirable hazards, associated radiological risk assessments, vulnerability assessments, and potential cask physical protection design modifications. This document includes an updated description of the test program and test components for all work and plans made, or revised, during FY 2004. It also serves as a program status report as of the end of FY 2004. All available test results, observations, and aerosol analyses plus interpretations--primarily for surrogate material Phase 2 tests, series 2/5A through 2/9B, using cerium oxide sintered ceramic pellets are included. Advanced plans and progress are described for upcoming tests with unirradiated, depleted uranium oxide and actual spent fuel test rodlets. This spent fuel sabotage--aerosol test program is coordinated with the international Working Group for Sabotage Concerns of

  1. Spent fuel sabotage aerosol ratio program : FY 2004 test and data summary.

    Energy Technology Data Exchange (ETDEWEB)

    Brucher, Wenzel (Gesellschaft fur Anlagen- und Reaktorsicherheit, Germany); Koch, Wolfgang (Fraunhofer Institut fur Toxikologie und Experimentelle Medizin, Germany); Pretzsch, Gunter Guido (Gesellschaft fur Anlagen- und Reaktorsicherheit, Germany); Loiseau, Olivier (Institut de Radioprotection et de Surete Nucleaire, France); Mo, Tin (U.S. Nuclear Regulatory Commission, Washington, DC); Billone, Michael C. (Argonne National Laboratory, Argonne, IL); Autrusson, Bruno A. (Institut de Radioprotection et de Surete Nucleaire, France); Young, F. I. (U.S. Nuclear Regulatory Commission, Washington, DC); Coats, Richard Lee; Burtseva, Tatiana (Argonne National Laboratory, Argonne, IL); Luna, Robert Earl; Dickey, Roy R.; Sorenson, Ken Bryce; Nolte, Oliver (Fraunhofer Institut fur Toxikologie und Experimentelle Medizin, Germany); Thompson, Nancy Slater (U.S. Department of Energy, Washington, DC); Hibbs, Russell S. (U.S. Department of Energy, Washington, DC); Gregson, Michael Warren; Lange, Florentin (Gesellschaft fur Anlagen- und Reaktorsicherheit, Germany); Molecke, Martin Alan; Tsai, Han-Chung (Argonne National Laboratory, Argonne, IL)

    2005-07-01

    This multinational, multi-phase spent fuel sabotage test program is quantifying the aerosol particles produced when the products of a high energy density device (HEDD) interact with and explosively particulate test rodlets that contain pellets of either surrogate materials or actual spent fuel. This program has been underway for several years. This program provides data that are relevant to some sabotage scenarios in relation to spent fuel transport and storage casks, and associated risk assessments. The program also provides significant technical and political benefits in international cooperation. We are quantifying the Spent Fuel Ratio (SFR), the ratio of the aerosol particles released from HEDD-impacted actual spent fuel to the aerosol particles produced from surrogate materials, measured under closely matched test conditions, in a contained test chamber. In addition, we are measuring the amounts, nuclide content, size distribution of the released aerosol materials, and enhanced sorption of volatile fission product nuclides onto specific aerosol particle size fractions. These data are the input for follow-on modeling studies to quantify respirable hazards, associated radiological risk assessments, vulnerability assessments, and potential cask physical protection design modifications. This document includes an updated description of the test program and test components for all work and plans made, or revised, during FY 2004. It also serves as a program status report as of the end of FY 2004. All available test results, observations, and aerosol analyses plus interpretations--primarily for surrogate material Phase 2 tests, series 2/5A through 2/9B, using cerium oxide sintered ceramic pellets are included. Advanced plans and progress are described for upcoming tests with unirradiated, depleted uranium oxide and actual spent fuel test rodlets. This spent fuel sabotage--aerosol test program is coordinated with the international Working Group for Sabotage Concerns of

  2. LWR aerosol containment experiments (LACE) program and initial test results

    International Nuclear Information System (INIS)

    Muhlestein, L.D.; Hilliard, R.K.; Bloom, G.R.; McCormack, J.D.; Rahn, F.J.

    1985-01-01

    The LWR aerosol containment experiments (LACE) program is described. The LACE program is being performed at the Hanford Engineer Development Laboratory (operated by Westinghouse Hanford Company) and the initial tests are sponsored by EPRI. The objectives of the LACE program are: to demonstrate, at large-scale, inherent radioactive aerosol retention behavior for postulated high consequence LWR accident situations; and to provide a data base to be used for aerosol behavior . Test results from the first phase of the LACE program are presented and discussed. Three large-scale scoping tests, simulating a containment bypass accident sequence, demonstrated the extent of agglomeration and deposition of aerosols occurring in the pipe pathway and vented auxiliary building under realistic accident conditions. Parameters varied during the scoping tests were aerosol type and steam condensation

  3. Aerosol can puncture device operational test plan

    International Nuclear Information System (INIS)

    Leist, K.J.

    1994-01-01

    Puncturing of aerosol cans is performed in the Waste Receiving and Processing Facility Module 1 (WRAP 1) process as a requirement of the waste disposal acceptance criteria for both transuranic (TRU) waste and low-level waste (LLW). These cans have contained such things as paints, lubricating oils, paint removers, insecticides, and cleaning supplies which were used in radioactive facilities. Due to Westinghouse Hanford Company (WHC) Fire Protection concerns of the baseline system's fire/explosion proof characteristics, a study was undertaken to compare the baseline system's design to commercially available puncturing devices. While the study found no areas which might indicate a risk of fire or explosion, WHC Fire Protection determined that the puncturing system must have a demonstrated record of safe operation. This could be obtained either by testing the baseline design by an independent laboratory, or by substituting a commercially available device. As a result of these efforts, the commercially available Aerosolv can puncturing device was chosen to replace the baseline design. Two concerns were raised with the system. Premature blinding of the coalescing/carbon filter, due to its proximity to the puncture and draining operation; and overpressurization of the collection bottle due to its small volume and by blinding of the filter assembly. As a result of these concerns, testing was deemed necessary. The objective of this report is to outline test procedures for the Aerosolv

  4. Sodium oxide aerosol behavior in a closed vessel. Comparison of computer modeling with aerosol experiments

    International Nuclear Information System (INIS)

    Fermandjian, Jean.

    1979-08-01

    Fast breeder reactor safety needs models validated to predict the behavior of sodium aerosols in the different reactor compartments during hypothetical sodium accident. Besides their chemical toxicity, the sodium aerosols are a transfer vector of radioactivity during a contaminated sodium fire. The purpose of this work is to validate models (HAARM 2 and PARDISEKO 3) with tests of sodium pool fires in a 400 m 3 concrete vessel in a confined atmosphere (CASSANDRE tests). The comparison between calculations and experimental results reveals that difficulties still exist, especially as to the selection of the values to be given to some input parameters (physical data of experimental origin, in particular the aerosols source function, the characteristics of the distribution of the emitted particles and the form factor of the agglomerated particles) [fr

  5. X-ray fluorimetry in tests of the aerosol substances

    International Nuclear Information System (INIS)

    Walentek, A.; Cudny, W.; Marzec, J.; Pawlowski, Z.; Zaremba, K.

    1992-01-01

    Test results of aerosol samples from atmospheric air collected from membrane drains were presented. The ANFLU-2 analyzer constructed at the Warsaw Technical University were used for testing. (author). 3 figs, 1 tab

  6. Elemental composition and oxidation of chamber organic aerosol

    Directory of Open Access Journals (Sweden)

    P. S. Chhabra

    2011-09-01

    Full Text Available Recently, graphical representations of aerosol mass spectrometer (AMS spectra and elemental composition have been developed to explain the oxidative and aging processes of secondary organic aerosol (SOA. It has been shown previously that oxygenated organic aerosol (OOA components from ambient and laboratory data fall within a triangular region in the f44 vs. f43 space, where f44 and f43 are the ratios of the organic signal at m/z 44 and 43 to the total organic signal in AMS spectra, respectively; we refer to this graphical representation as the "triangle plot." Alternatively, the Van Krevelen diagram has been used to describe the evolution of functional groups in SOA. In this study we investigate the variability of SOA formed in chamber experiments from twelve different precursors in both "triangle plot" and Van Krevelen domains. Spectral and elemental data from the high-resolution Aerodyne aerosol mass spectrometer are compared to offline species identification analysis and FTIR filter analysis to better understand the changes in functional and elemental composition inherent in SOA formation and aging. We find that SOA formed under high- and low-NOx conditions occupy similar areas in the "triangle plot" and Van Krevelen diagram and that SOA generated from already oxidized precursors allows for the exploration of areas higher on the "triangle plot" not easily accessible with non-oxidized precursors. As SOA ages, it migrates toward the top of the triangle along a path largely dependent on the precursor identity, which suggests increasing organic acid content and decreasing mass spectral variability. The most oxidized SOA come from the photooxidation of methoxyphenol precursors which yielded SOA O/C ratios near unity. α-pinene ozonolysis and naphthalene photooxidation SOA systems have had the highest degree of mass closure in previous chemical characterization studies and also show the

  7. Containment aerosol behaviour simulation studies in the BARC nuclear aerosol test facility

    International Nuclear Information System (INIS)

    Mayya, Y.S.; Sapra, B.K.; Khan, Arshad; Sunny, Faby; Nair, R.N.; Raghunath, Radha; Tripathi, R.M.; Markandeya, S.G.; Puranik, V.D.; Ghosh, A.K.; Kushwaha, H.S.; Shreekumar, K.P.; Padmanabhan, P.V.A.; Murthy, P.S.S.; Venlataramani, N.

    2005-02-01

    A Nuclear Aerosol Test Facility (NATF) has been built and commissioned at Bhabha Atomic Research Centre to carry out simulation studies on the behaviour of aerosols released into the reactor containment under accident conditions. This report also discusses some new experimental techniques for estimation of density of metallic aggregates. The experimental studies have shown that the dynamic densities of aerosol aggregates are far lower than their material densities as expected by the well-known fractal theory of aggregates. In the context of codes, this has significant bearing in providing a mechanistic basis for the input density parameter used in estimating the aerosol evolution characteristics. The data generated under the quiescent and turbulent conditions and the information on aggregate densities are now being subjected to the validation of the aerosol behaviour codes. (author)

  8. Analyses of CsI aerosol deposition in aerosol behavior tests in WIND project

    International Nuclear Information System (INIS)

    Kudo, Tamotsu; Shibazaki, Hiroaki; Hidaka, Akihide

    1999-01-01

    The aerosol deposition tests have been performed in WIND project at JAERI to characterize the aerosol behavior. The aerosol deposition tests named WAV1-D and WAV2-D were analyzed by aerosol behavior analysis codes, JAERI's ART and SNL's VICTORIA. The comparison calculation was performed for the confirmation of the analytical capabilities of the both codes and improvement of the models in ART. The deposition mass calculated by ART was larger than that by VICTORIA. This discrepancy is caused by differences in model for FP vapor condensation onto the wall surface. In the WAV2-D test, in which boric acid was placed on the floor area of the test section prior to the deposition phase to simulate the PWR primary coolant, there was a discrepancy in deposition mass between analytical results in both codes and experimental results. The discrepancy may be caused by existence of boric acid which is not considered in the codes. (author)

  9. Uranium Oxide Aerosol Transport in Porous Graphite

    Energy Technology Data Exchange (ETDEWEB)

    Blanchard, Jeremy; Gerlach, David C.; Scheele, Randall D.; Stewart, Mark L.; Reid, Bruce D.; Gauglitz, Phillip A.; Bagaasen, Larry M.; Brown, Charles C.; Iovin, Cristian; Delegard, Calvin H.; Zelenyuk, Alla; Buck, Edgar C.; Riley, Brian J.; Burns, Carolyn A.

    2012-01-23

    The objective of this paper is to investigate the transport of uranium oxide particles that may be present in carbon dioxide (CO2) gas coolant, into the graphite blocks of gas-cooled, graphite moderated reactors. The transport of uranium oxide in the coolant system, and subsequent deposition of this material in the graphite, of such reactors is of interest because it has the potential to influence the application of the Graphite Isotope Ratio Method (GIRM). The GIRM is a technology that has been developed to validate the declared operation of graphite moderated reactors. GIRM exploits isotopic ratio changes that occur in the impurity elements present in the graphite to infer cumulative exposure and hence the reactor’s lifetime cumulative plutonium production. Reference Gesh, et. al., for a more complete discussion on the GIRM technology.

  10. Pretest aerosol code comparisons for LWR aerosol containment tests LA1 and LA2

    International Nuclear Information System (INIS)

    Wright, A.L.; Wilson, J.H.; Arwood, P.C.

    1986-01-01

    The Light-Water-Reactor (LWR) Aerosol Containment Experiments (LACE) are being performed in Richland, Washington, at the Hanford Engineering Development Laboratory (HEDL) under the leadership of an international project board and the Electric Power Research Institute. These tests have two objectives: (1) to investigate, at large scale, the inherent aerosol retention behavior in LWR containments under simulated severe accident conditions, and (2) to provide an experimental data base for validating aerosol behavior and thermal-hydraulic computer codes. Aerosol computer-code comparison activities are being coordinated at the Oak Ridge National Laboratory. For each of the six LACE tests, ''pretest'' calculations (for code-to-code comparisons) and ''posttest'' calculations (for code-to-test data comparisons) are being performed. The overall goals of the comparison effort are (1) to provide code users with experience in applying their codes to LWR accident-sequence conditions and (2) to evaluate and improve the code models

  11. Spent fuel sabotage test program, characterization of aerosol dispersal : interim final report

    International Nuclear Information System (INIS)

    Gregson, Michael Warren; Brockmann, John E.; Loiseau, Olivier; Klennert, Lindsay A.; Nolte, Oliver; Molecke, Martin Alan; Autrusson, Bruno A.; Koch, Wolfgang; Pretzsch, Gunter Guido; Brucher, Wenzel; Steyskal, Michele D.

    2008-01-01

    This multinational, multi-phase spent fuel sabotage test program is quantifying the aerosol particles produced when the products of a high energy density device (HEDD) interact with and explosively particulate test rodlets that contain pellets of either surrogate materials or actual spent fuel. This program provides source-term data that are relevant to plausible sabotage scenarios in relation to spent fuel transport and storage casks and associated risk assessments. We present details and significant results obtained from this program from 2001 through 2007. Measured aerosol results include: respirable fractions produced; amounts, nuclide content, and produced particle size distributions and morphology; measurements of volatile fission product species enhanced sorption--enrichment factors onto respirable particles; and, status on determination of the spent fuel ratio, SFR, needed for scaling studies. Emphasis is provided on recent Phase 3 tests using depleted uranium oxide pellets plus non-radioactive fission product dopants in surrogate spent fuel test rodlets, plus the latest surrogate cerium oxide results and aerosol laboratory supporting calibration work. The DUO 2 , CeO 2 , plus fission product dopant aerosol particle results are compared with available historical data. We also provide a status review on continuing preparations for the final Phase 4 in this program, tests using individual short rodlets containing actual spent fuel from U.S. PWR reactors, with both high- and lower-burnup fuel. The source-term data, aerosol results, and program design have been tailored to support and guide follow-on computer modeling of aerosol dispersal hazards and radiological consequence assessments. This spent fuel sabotage, aerosol test program was performed primarily at Sandia National Laboratories, with support provided by both the U.S. Department of Energy and the Nuclear Regulatory Commission. This program has significant input from, and is cooperatively supported and

  12. A Miniaturized Nickel Oxide Thermistor via Aerosol Jet Technology.

    Science.gov (United States)

    Wang, Chia; Hong, Guan-Yi; Li, Kuan-Ming; Young, Hong-Tsu

    2017-11-12

    In this study, a miniaturized thermistor sensor was produced using the Aerosol Jet printing process for temperature sensing applications. A nickel oxide nanoparticle ink with a large temperature coefficient of resistance was fabricated. The thermistor was printed with a circular NiO thin film in between the two parallel silver conductive tracks on a cutting tool insert. The printed thermistor, which has an adjustable dimension with a submillimeter scale, operates over a range of 30-250 °C sensitively (B value of ~4310 K) without hysteretic effects. Moreover, the thermistor may be printed on a 3D surface through the Aerosol Jet printing process, which has increased capability for wide temperature-sensing applications.

  13. Importance of relative humidity in the oxidative ageing of organic aerosols: case study of the ozonolysis of maleic acid aerosol

    Directory of Open Access Journals (Sweden)

    P. J. Gallimore

    2011-12-01

    Full Text Available Many important atmospheric aerosol processes depend on the chemical composition of the aerosol, e.g. water uptake and particle cloud interactions. Atmospheric ageing processes, such as oxidation reactions, significantly and continuously change the chemical composition of aerosol particles throughout their lifetime. These ageing processes are often poorly understood. In this study we utilize an aerosol flow tube set up and an ultra-high resolution mass spectrometer to explore the effect of relative humidity (RH in the range of <5–90% on the ozonolysis of maleic acid aerosol which is employed as model organic aerosol system. Due to the slow reaction kinetics relatively high ozone concentrations of 160–200 ppm were used to achieve an appreciable degree of oxidation of maleic acid. The effect of oxidative ageing on the hygroscopicity of maleic acid particles is also investigated using an electrodynamic balance and thermodynamic modelling. RH has a profound effect on the oxidation of maleic acid particles. Very little oxidation is observed at RH < 50% and the only observed reaction products are glyoxylic acid and formic acid. In comparison, when RH > 50% there are about 15 oxidation products identified. This increased oxidation was observed even when the particles were exposed to high humidities long after a low RH ozonolysis reaction. This result might have negative implications for the use of water as an extraction solvent for the analysis of oxidized organic aerosols. These humidity-dependent differences in the composition of the ozonolyzed aerosol demonstrate that water is both a key reactant in the oxidation scheme and a determinant of particle phase and hence diffusivity. The measured chemical composition of the processed aerosol is used to model the hygroscopic growth, which compares favourably with water uptake results from the electrodynamic balance measurements. A reaction mechanism is presented which takes into account the RH dependent

  14. Modeling organic aerosol from the oxidation of α-pinene in a Potential Aerosol Mass (PAM chamber

    Directory of Open Access Journals (Sweden)

    S. Chen

    2013-05-01

    Full Text Available A model has been developed to simulate the formation and evolution of secondary organic aerosol (SOA and was tested against data produced in a Potential Aerosol Mass (PAM flow reactor and a large environmental chamber. The model framework is based on the two-dimensional volatility basis set approach (2D-VBS, in which SOA oxidation products in the model are distributed on the 2-D space of effective saturation concentration (Ci* and oxygen-to-carbon ratio (O : C. The modeled organic aerosol mass concentrations (COA and O : C agree with laboratory measurements within estimated uncertainties. However, while both measured and modeled O : C increase with increasing OH exposure as expected, the increase of modeled O : C is rapid at low OH exposure and then slows as OH exposure increases while the increase of measured O : C is initially slow and then accelerates as OH exposure increases. A global sensitivity analysis indicates that modeled COA values are most sensitive to the assumed values for the number of Ci* bins, the heterogeneous OH reaction rate coefficient, and the yield of first-generation products. Modeled SOA O : C values are most sensitive to the assumed O : C of first-generation oxidation products, the number of Ci* bins, the heterogeneous OH reaction rate coefficient, and the number of O : C bins. All these sensitivities vary as a function of OH exposure. The sensitivity analysis indicates that the 2D-VBS model framework may require modifications to resolve discrepancies between modeled and measured O : C as a function of OH exposure.

  15. GENERATION, TRANSPORT AND DEPOSITION OF TUNGSTEN-OXIDE AEROSOLS AT 1000 C IN FLOWING AIR-STEAM MIXTURES.

    Energy Technology Data Exchange (ETDEWEB)

    GREENE,G.A.; FINFROCK,C.C.

    2001-10-01

    Experiments were conducted to measure the rates of oxidation and vaporization of pure tungsten rods in flowing air, steam and air-steam mixtures in laminar flow. Also measured were the downstream transport of tungsten-oxide condensation aerosols and their region of deposition, including plateout in the superheated flow tube, rainout in the condenser and ambient discharge which was collected on an array of sub-micron aerosol filters. The nominal conditions of the tests, with the exception of the first two tests, were tungsten temperatures of 1000 C, gas mixture temperatures of 200 C and wall temperatures of 150 C to 200 C. It was observed that the tungsten oxidation rates were greatest in all air and least in all steam, generally decreasing non-linearly with increasing steam mole fraction. The tungsten oxidation rates in all air were more than five times greater than the tungsten oxidation rates in all steam. The tungsten vaporization rate was zero in all air and increased with increasing steam mole fraction. The vaporization rate became maximum at a steam mole fraction of 0.85 and decreased thereafter as the steam mole fraction was increased to unity. The tungsten-oxide was transported downstream as condensation aerosols, initially flowing upwards from the tungsten rod through an 18-inch long, one-inch diameter quartz tube, around a 3.5-inch radius, 90{sup o} bend and laterally through a 24-inch horizontal run. The entire length of the quartz glass flow path was heated by electrical resistance clamshell heaters whose temperatures were individually controlled and measured. The tungsten-oxide plateout in the quartz tube was collected, nearly all of which was deposited at the end of the heated zone near the entrance to the condenser which was cold. The tungsten-oxide which rained out in the condenser as the steam condensed was collected with the condensate and weighed after being dried. The aerosol smoke which escaped the condenser was collected on the sub

  16. Iodine oxides in large-scale THAI tests

    International Nuclear Information System (INIS)

    Funke, F.; Langrock, G.; Kanzleiter, T.; Poss, G.; Fischer, K.; Kühnel, A.; Weber, G.; Allelein, H.-J.

    2012-01-01

    Highlights: ► Iodine oxide particles were produced from gaseous iodine and ozone. ► Ozone replaced the effect of ionizing radiation in the large-scale THAI facility. ► The mean diameter of the iodine oxide particles was about 0.35 μm. ► Particle formation was faster than the chemical reaction between iodine and ozone. ► Deposition of iodine oxide particles was slow in the absence of other aerosols. - Abstract: The conversion of gaseous molecular iodine into iodine oxide aerosols has significant relevance in the understanding of the fission product iodine volatility in a LWR containment during severe accidents. In containment, the high radiation field caused by fission products released from the reactor core induces radiolytic oxidation into iodine oxides. To study the characteristics and the behaviour of iodine oxides in large scale, two THAI tests Iod-13 and Iod-14 were performed, simulating radiolytic oxidation of molecular iodine by reaction of iodine with ozone, with ozone injected from an ozone generator. The observed iodine oxides form submicron particles with mean volume-related diameters of about 0.35 μm and show low deposition rates in the THAI tests performed in the absence of other nuclear aerosols. Formation of iodine aerosols from gaseous precursors iodine and ozone is fast as compared to their chemical interaction. The current approach in empirical iodine containment behaviour models in severe accidents, including the radiolytic production of I 2 -oxidizing agents followed by the I 2 oxidation itself, is confirmed by these THAI tests.

  17. Characteristics of agglomerates of sodium oxide aerosol particles: Task 7, topical report

    International Nuclear Information System (INIS)

    Gieseke, J.A.; Reed, L.D.; Jordan, H.; Lee, K.W.

    1977-01-01

    Accurate macroscopic predictions of aerosol population behavior within enclosed containments are known to depend strongly upon the microscopic characteristics of the individual aerosols. Also, coagulation rates due to mechanisms which produce relative motions between particles within the suspended aerosol are known to depend upon the cross sectional areas of the individual particles. Hence, it has been the primary concern of this study to examine experimentally the microscopic characteristics of sodium oxide aerosols produced in air. The results of these measurements can now be incorporated into the various macroscopic aerosol behavior prediction models

  18. Plutonium-containing aerosols found within containment enclosures in industrial mixed-oxide reactor fuel fabrication

    International Nuclear Information System (INIS)

    Newton, G.J.; Yeh, H.C.; Stanley, J.A.

    1977-01-01

    Mixed oxide (PuO 2 and UO 2 ) nuclear reactor fuel pellets are fabricated within safety enclosures at Babcock and Wilcox's Park Township site near Apollo, PA. Forty-two sample runs of plutonium-containing aerosols were taken from within glove boxes during routine industrial operations. A small, seven-stage cascade impactor and the Lovelace Aerosol Particle Separator (LAPS) were used to determine aerodynamic size distribution and gross alpha aerosol concentration. Powder comminution and blending produced aerosols with lognormal size distributions characterized by activity median aerodynamic diameters (AMAD) of 1.89 +- 0.33 μm, sigma/sub g/ = 1.62 +- 0.09 and a gross alpha aerosol concentration range of 0.1 to 150 nCi/l. Slug pressing and grinding produced aerosols of AMAD = 3.08 +- 0.1 μm, sigma/sub g/ = 1.53 +- 0.01 and AMAD = 2.26 +- 0.16 μm, sigma/sub g/ = 1.68 +- 0.20, respectively. Gross alpha aerosol concentrations ranged from 3.4 to 450 nCi/l. Centerless grinding produced similar-sized aerosols but the gross alpha concentration ranged from 220 to 1690 nCi/l. In vitro solubility studies on selected LAPS samples in a lung fluid simulant indicate that plutonium mixed-oxide aerosols are more soluble than laboratory-produced plutonium aerosols

  19. Flame generation of sodium chloride aerosol for filter testing

    International Nuclear Information System (INIS)

    Edwards, J.; Kinnear, D.I.

    1975-01-01

    A generator for sodium chloride aerosol is described, which when used in conjunction with a sensitive portable sodium flame detector unit, will permit the in-place testing of large filter installations having air throughputs up to about 80,000 m 3 /h, at penetrations down to at least 0.005 percent. (U.S.)

  20. Study of the sodium oxide aerosol behavior in a containment building

    International Nuclear Information System (INIS)

    Fermandjian, Jean.

    1982-01-01

    Fast breeder reactor safety analysis needs validated models to predict the behavior of sodium oxide aerosols (released during hypothetical accidents) in the different reactor compartments and, in particular, to evaluate the quantity (and the size distribution) of the particles which can be released outside the containment building by taking into account the associated devices (ventilation, especially). In order to validate the computer models, experimental tests were performed by CEA/DSN (Atomic Energy Commission/Nuclear Safety Department) at Cadarache: sodium pool fire tests in a 400 m 3 concrete vessel (CASSANDRE tests) and in a 4.4 m 3 steel vessel (EMIS tests). Furthermore, we utilized the results of the experimental tests performed by our German colleagues of KFK/LAF (Kernforschungszentrum Karlsruhe/Laboratorium fuer Aerosolphysik und Filtertechnik): sodium pool fire tests in a 220 m 3 steel vessel (FAUNA tests). The application of the computer models to the experimental tests and to the reactor case allowed us: - to explain the differences observed between the results given by the codes ''with log-normal hypothesis'' (HAARM 3) and ''with finite difference'' (PARDISEKO 3B), - to define the limits of application of the codes ''with log-normal hypothesis'', - to determine the important parameters (characteristics of the aerosol source, form factors of the agglomerates and collision efficiency) and the important phenomena (turbulent coagulation, in particular) [fr

  1. Determination of permeability of ultra-fine cupric oxide aerosol through military filters and protective filters

    Science.gov (United States)

    Kellnerová, E.; Večeřa, Z.; Kellner, J.; Zeman, T.; Navrátil, J.

    2018-03-01

    The paper evaluates the filtration and sorption efficiency of selected types of military combined filters and protective filters. The testing was carried out with the use of ultra-fine aerosol containing cupric oxide nanoparticles ranging in size from 7.6 nm to 299.6 nm. The measurements of nanoparticles were carried out using a scanning mobility particle sizer before and after the passage through the filter and a developed sampling device at the level of particle number concentration approximately 750000 particles·cm-3. The basic parameters of permeability of ultra-fine aerosol passing through the tested material were evaluated, in particular particle size, efficiency of nanoparticle capture by filter, permeability coefficient and overall filtration efficiency. Results indicate that the military filter and particle filters exhibited the highest aerosol permeability especially in the nanoparticle size range between 100–200 nm, while the MOF filters had the highest permeability in the range of 200 to 300 nm. The Filter Nuclear and the Health and Safety filter had 100% nanoparticle capture efficiency and were therefore the most effective. The obtained measurement results have shown that the filtration efficiency over the entire measured range of nanoparticles was sufficient; however, it was different for particular particle sizes.

  2. Aerosol generation by oxidation and combustion of plutonium and its compounds: literature survey

    International Nuclear Information System (INIS)

    Ballereau, P.

    1987-09-01

    Generation of aerosols by oxidation or combustion is one of the greatest risks due to plutonium. A review is made of the most interesting documents available on this topic. Following a brief study of plutonium oxydation conditions, characteristics of aerosols generated by accidents of fires involving metallic Pu and some of its compounds are assessed. Nuclear weapons are not included in this review [fr

  3. Spent fuel sabotage test program, characterization of aerosol dispersal : interim final report.

    Energy Technology Data Exchange (ETDEWEB)

    Gregson, Michael Warren; Brockmann, John E.; Loiseau, Olivier (Institut de Radioprotection et de Surete Nucleaire, France); Klennert, Lindsay A.; Nolte, Oliver (Fraunhofer Institut fur Toxikologie und Experimentelle Medizin, Germany); Molecke, Martin Alan; Autrusson, Bruno A. (Institut de Radioprotection et de Surete Nucleaire, France); Koch, Wolfgang (Fraunhofer Institut fur Toxikologie und Experimentelle Medizin, Germany); Pretzsch, Gunter Guido (Gesellschaft fur Anlagen- und Reaktorsicherheit, Germany); Brucher, Wenzel (Gesellschaft fur Anlagen- und Reaktorsicherheit, Germany); Steyskal, Michele D.

    2008-03-01

    This multinational, multi-phase spent fuel sabotage test program is quantifying the aerosol particles produced when the products of a high energy density device (HEDD) interact with and explosively particulate test rodlets that contain pellets of either surrogate materials or actual spent fuel. This program provides source-term data that are relevant to plausible sabotage scenarios in relation to spent fuel transport and storage casks and associated risk assessments. We present details and significant results obtained from this program from 2001 through 2007. Measured aerosol results include: respirable fractions produced; amounts, nuclide content, and produced particle size distributions and morphology; measurements of volatile fission product species enhanced sorption--enrichment factors onto respirable particles; and, status on determination of the spent fuel ratio, SFR, needed for scaling studies. Emphasis is provided on recent Phase 3 tests using depleted uranium oxide pellets plus non-radioactive fission product dopants in surrogate spent fuel test rodlets, plus the latest surrogate cerium oxide results and aerosol laboratory supporting calibration work. The DUO{sub 2}, CeO{sub 2}, plus fission product dopant aerosol particle results are compared with available historical data. We also provide a status review on continuing preparations for the final Phase 4 in this program, tests using individual short rodlets containing actual spent fuel from U.S. PWR reactors, with both high- and lower-burnup fuel. The source-term data, aerosol results, and program design have been tailored to support and guide follow-on computer modeling of aerosol dispersal hazards and radiological consequence assessments. This spent fuel sabotage, aerosol test program was performed primarily at Sandia National Laboratories, with support provided by both the U.S. Department of Energy and the Nuclear Regulatory Commission. This program has significant input from, and is cooperatively

  4. Formation of secondary organic aerosol from isoprene oxidation over Europe

    Directory of Open Access Journals (Sweden)

    M. Karl

    2009-09-01

    Full Text Available The role of isoprene as a precursor to secondary organic aerosol (SOA over Europe is studied with the two-way nested global chemistry transport model TM5. The inclusion of the formation of SOA from isoprene oxidation in our model almost doubles the atmospheric burden of SOA over Europe compared to SOA formation from terpenes and aromatics. The reference simulation, which considers SOA formation from isoprene, terpenes and aromatics, predicts a yearly European production rate of 1.0 Tg SOA yr−1 and an annual averaged atmospheric burden of about 50 Gg SOA over Europe. A fraction of 35% of the SOA produced in the boundary layer over Europe is transported to higher altitudes or to other world regions. Summertime measurements of organic matter (OM during the extensive EMEP OC/EC campaign 2002/2003 are better reproduced when SOA formation from isoprene is taken into account, reflecting also the strong seasonality of isoprene and other biogenic volatile organic compounds (BVOC emissions from vegetation. However, during winter, our model strongly underestimates OM, likely caused by missing wood burning in the emission inventories. Uncertainties in the parameterisation of isoprene SOA formation have been investigated. Maximum SOA production is found for irreversible sticking (non-equilibrium partitioning of condensable vapours on particles, with tropospheric SOA production over Europe increased by a factor of 4 in summer compared to the reference case. Completely neglecting SOA formation from isoprene results in the lowest estimate (0.51 Tg SOA yr−1. The amount and the nature of the absorbing matter are shown to be another key uncertainty when predicting SOA levels. Consequently, smog chamber experiments on SOA formation should be performed with different types of seed aerosols and without seed aerosols in order to derive an improved treatment of the absorption of SOA in the models. Consideration of a number of recent insights

  5. Summary of aerosol code-comparison results for LWR aerosol containment tests LA1, LA2, and LA3

    International Nuclear Information System (INIS)

    Wright, A.L.; Wilson, J.H.; Arwood, P.C.

    1987-01-01

    The light-water reactor (LWR) aerosol containment experiments (LACE) are being performed in Richland, Washington, at the Hanford Engineering Development Laboratory under the leadership of an international project board and the Electric Power Research Institute. These tests have two objectives: (1) to investigate, at large scale, the inherent aerosol retention behavior in LWR containments under simulated severe accident conditions, and (2) to provide an experimental data base for validating aerosol behavior and thermal-hydraulic computer codes. Aerosol computer-code comparison activities for the LACE tests are being coordinated at the Oak Ridge National Laboratory. For each of the six experiments, pretest calculations (for code-to-code comparisons) and blind post-test calculations (for code-to-test data comparisons) are being performed. This paper presents a summary of the pretest aerosol-code results for tests LA1, LA2, and LA3

  6. Effect of glutathione aerosol on oxidant-antioxidant imbalance in idiopathic pulmonary fibrosis.

    Science.gov (United States)

    Borok, Z; Buhl, R; Grimes, G J; Bokser, A D; Hubbard, R C; Holroyd, K J; Roum, J H; Czerski, D B; Cantin, A M; Crystal, R G

    1991-07-27

    Idiopathic pulmonary fibrosis (IPF) is characterised by alveolar inflammation, exaggerated release of oxidants, and subnormal concentrations of the antioxidant glutathione in respiratory epithelial lining fluid (ELF). Glutathione (600 mg twice daily for 3 days) was given by aerosol to 10 patients with IPF. Total ELF glutathione rose transiently, ELF oxidised glutathione concentrations increased, and there was a decrease in spontaneous superoxide anion release by alveolar macrophages. Thus, glutathione by aerosol could be a means of reversing the oxidant-antioxidant imbalance in IPF.

  7. Real-time, controlled OH-initiated oxidation of biogenic secondary organic aerosol

    Directory of Open Access Journals (Sweden)

    J. G. Slowik

    2012-10-01

    Full Text Available The chemical complexity of atmospheric organic aerosol (OA requires novel methods for characterization of its components and description of its atmospheric processing-induced transformations. We present the first field deployment of the Toronto Photooxidation Tube (TPOT, a field-deployable flow reactor for the controlled exposure of ambient aerosol to OH radicals. The system alternates between sampling of (1 (unreacted ambient aerosol, (2 aerosol exposed to UV light and subjected to a ~4 to 10 °C temperature increase, and (3 aerosol that is oxidized by OH (in addition to the aforementioned UV exposure/temperature increase. This allows both characterization of the aging process and classification of aerosol in terms of its volatility and reaction-based properties. Summertime measurements by an aerosol mass spectrometer coupled to the TPOT were performed in the remote forest of western Canada, resulting in aerosol dominated by biogenic secondary organic aerosol. Volatilization/UV exposure resulted in an approximately 10 to 25% decrease in organic mass and resulted in a slight increase in oxygenation. OH oxidation resulted in a further organic mass decrease (additional ~25% and yielded an aerosol with O:C values comparable to those characteristic of low volatility, highly oxygenated OA. Most OH-induced changes occurred within ~3 day-equivalents of atmospheric processing, with further reactions generally proceeding at a greatly reduced rate. Positive matrix factorization (PMF analysis of the TPOT data yielded five factors. One factor is related to primary biomass burning organic aerosol, while the others describe oxygenated organic aerosol (OOA components in terms of reactivity and volatility: (1 volatile and reactive; (2 non-volatile and reactive; (3 non-volatile and reactive early-generation product; (4 non-volatile and non-reactive product. This PMF classification of aerosol components directly in terms of reactivity and volatility is enabled by

  8. Products of BVOC oxidation: ozone and organic aerosols

    Science.gov (United States)

    Wildt, Jürgen; Andres, Stefanie; Carriero, Giulia; Ehn, Mikael; Fares, Silvano; Hoffmann, Thorsten; Hacker, Lina; Kiendler-Scharr, Astrid; Kleist, Einhard; Paoletti, Elena; Pullinen, Iida; Rohrer, Franz; Rudich, Yinon; Springer, Monika; Tillmann, Ralf; Wahner, Andreas; Wu, Cheng; Mentel, Thomas

    2015-04-01

    Biogenic Volatile Organic Compounds (BVOC) are important precursors in photochemical O3 and secondary organic aerosol (SOA) formation. We conducted a series of laboratory experiments with OH-induced oxidation of monoterpenes to elucidate pathways and efficiencies of O3 and SOA formation. At high NOx conditions ([BVOC] / [NOx] monoterpene mixes emitted from different plant species we observed increasing ozone formation with increasing [NOX]. Between 2 and 3 O3-molecules were formed from 1 monoterpene when ozone formation was BVOC limited. Under such high NOX conditions, new particle formation was suppressed. Increasing [BVOC] / [NOX] ratios caused increasing efficiency of new particle formation indicating that peroxy radicals are the key intermediates in both, photochemical ozone- and new particle formation. The classical chemistry of peroxy radicals is well established (e.g. Master Chemical Mechanism). Peroxy radicals are produced by addition of molecular oxygen to the alkyl radical formed after OH attack at the BVOC. They either react with NO which leads to ozone formation or they react with other peroxy radicals and form chemically stable products (hydroperoxides, alkoholes and ketones). Much less knowledge exists on such reactions for Highly Oxidized Peroxy Radicals, (HOPR). Such HOPR were observed during ozonolysis of several volatiles and, in case of monoterpenes as precursors, they can contain more than 12 Oxygen atoms (Mentel et al., 2015). Although the OH-initiated formation of HOPR is yet not fully understood, their basic gas phase reactions seem to follow classical photochemical rules. In reactions with NO they can act as precursor for O3 and in reactions with other HOPR or with classical less oxidized peroxy radicals they can form highly oxidized stable products and alkoxy radicals. In addition, HOPR-HOPR reactions lead to the formation of dimers that, in case of monoterpenes as reactants, consist of a skeleton with 20 carbon atoms. These dimers seem to

  9. In Vitro Tests for Aerosol Deposition. V: Using Realistic Testing to Estimate Variations in Aerosol Properties at the Trachea.

    Science.gov (United States)

    Wei, Xiangyin; Hindle, Michael; Delvadia, Renishkumar R; Byron, Peter R

    2017-10-01

    The dose and aerodynamic particle size distribution (APSD) of drug aerosols' exiting models of the mouth and throat (MT) during a realistic inhalation profile (IP) may be estimated in vitro and designated Total Lung Dose, TLD in vitro , and APSD TLDin vitro , respectively. These aerosol characteristics likely define the drug's regional distribution in the lung. A general method was evaluated to enable the simultaneous determination of TLD in vitro and APSD TLDin vitro for budesonide aerosols' exiting small, medium and large VCU-MT models. Following calibration of the modified next generation pharmaceutical impactor (NGI) at 140 L/min, variations in aerosol dose and size exiting MT were determined from Budelin ® Novolizer ® across the IPs reported by Newman et al., who assessed drug deposition from this inhaler by scintigraphy. Values for TLD in vitro from the test inhaler determined by the general method were found to be statistically comparable to those using a filter capture method. Using new stage cutoffs determined by calibration of the modified NGI at 140 L/min, APSD TLDin vitro profiles and mass median aerodynamic diameters at the MT exit (MMAD TLDin vitro ) were determined as functions of MT geometric size across Newman's IPs. The range of mean values (n ≥ 5) for TLD in vitro and MMAD TLDin vitro for this inhaler extended from 6.2 to 103.0 μg (3.1%-51.5% of label claim) and from 1.7 to 3.6 μm, respectively. The method enables reliable determination of TLD in vitro and APSD TLDin vitro for aerosols likely to enter the trachea of test subjects in the clinic. By simulating realistic IPs and testing in different MT models, the effects of major variables on TLD in vitro and APSD TLDin vitro may be studied using the general method described in this study.

  10. Microfluidic electrochemical sensor for on-line monitoring of aerosol oxidative activity.

    Science.gov (United States)

    Sameenoi, Yupaporn; Koehler, Kirsten; Shapiro, Jeff; Boonsong, Kanokporn; Sun, Yele; Collett, Jeffrey; Volckens, John; Henry, Charles S

    2012-06-27

    Particulate matter (PM) air pollution has a significant impact on human morbidity and mortality; however, the mechanisms of PM-induced toxicity are poorly defined. A leading hypothesis states that airborne PM induces harm by generating reactive oxygen species in and around human tissues, leading to oxidative stress. We report here a system employing a microfluidic electrochemical sensor coupled directly to a particle-into-liquid sampler (PILS) system to measure aerosol oxidative activity in an on-line format. The oxidative activity measurement is based on the dithiothreitol (DTT) assay, where, after being oxidized by PM, the remaining reduced DTT is analyzed by the microfluidic sensor. The sensor consists of an array of working, reference, and auxiliary electrodes fabricated in a poly(dimethylsiloxane)-based microfluidic device. Cobalt(II) phthalocyanine-modified carbon paste was used as the working electrode material, allowing selective detection of reduced DTT. The electrochemical sensor was validated off-line against the traditional DTT assay using filter samples taken from urban environments and biomass burning events. After off-line characterization, the sensor was coupled to a PILS to enable on-line sampling/analysis of aerosol oxidative activity. Urban dust and industrial incinerator ash samples were aerosolized in an aerosol chamber and analyzed for their oxidative activity. The on-line sensor reported DTT consumption rates (oxidative activity) in good correlation with aerosol concentration (R(2) from 0.86 to 0.97) with a time resolution of approximately 3 min.

  11. Large-Scale Spray Releases: Additional Aerosol Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Daniel, Richard C.; Gauglitz, Phillip A.; Burns, Carolyn A.; Fountain, Matthew S.; Shimskey, Rick W.; Billing, Justin M.; Bontha, Jagannadha R.; Kurath, Dean E.; Jenks, Jeromy WJ; MacFarlan, Paul J.; Mahoney, Lenna A.

    2013-08-01

    One of the events postulated in the hazard analysis for the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak event involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids that behave as a Newtonian fluid. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and in processing facilities across the DOE complex. To expand the data set upon which the WTP accident and safety analyses were based, an aerosol spray leak testing program was conducted by Pacific Northwest National Laboratory (PNNL). PNNL’s test program addressed two key technical areas to improve the WTP methodology (Larson and Allen 2010). The first technical area was to quantify the role of slurry particles in small breaches where slurry particles may plug the hole and prevent high-pressure sprays. The results from an effort to address this first technical area can be found in Mahoney et al. (2012a). The second technical area was to determine aerosol droplet size distribution and total droplet volume from prototypic breaches and fluids, including sprays from larger breaches and sprays of slurries for which literature data are mostly absent. To address the second technical area, the testing program collected aerosol generation data at two scales, commonly referred to as small-scale and large-scale testing. The small-scale testing and resultant data are described in Mahoney et al. (2012b), and the large-scale testing and resultant data are presented in Schonewill et al. (2012). In tests at both scales, simulants were used

  12. Local transport of vertically and horizontally emitted sodium oxide aerosols

    International Nuclear Information System (INIS)

    Fields, D.E.; Miller, C.W.; Cooper, A.C.

    1986-01-01

    Liquid-metal-cooled breeder reactors are expected to use large quantities of sodium or sodium-potassium alloy, and evaluation of the possible consequences of a liquid-metal fire, henceforth referred to as a sodium fire, is an important consideration. Of particular interest is the sodium aerosol concentration at the air intake ports that are used for reactor cooling, and which might suffer restricted flow under high aerosol concentrations. The authors have devised and applied a methodology for estimating the concentration of aerosols released vertically and horizontally from building surfaces and monitored at other building surface points. This methodology has been used to make calculations that indicate the time development of aerosol buildup, and the maximum aerosol concentration, at air intake ports. Building wake effects, momentum-driven plume rise, and density-driven plume rise are considered

  13. LABORATORY EVALUATION OF A MICROFLUIDIC ELECTROCHEMICAL SENSOR FOR AEROSOL OXIDATIVE LOAD.

    Science.gov (United States)

    Koehler, Kirsten; Shapiro, Jeffrey; Sameenoi, Yupaporn; Henry, Charles; Volckens, John

    2014-05-01

    Human exposure to particulate matter (PM) air pollution is associated with human morbidity and mortality. The mechanisms by which PM impacts human health are unresolved, but evidence suggests that PM intake leads to cellular oxidative stress through the generation of reactive oxygen species (ROS). Therefore, reliable tools are needed for estimating the oxidant generating capacity, or oxidative load, of PM at high temporal resolution (minutes to hours). One of the most widely reported methods for assessing PM oxidative load is the dithiothreitol (DTT) assay. The traditional DTT assay utilizes filter-based PM collection in conjunction with chemical analysis to determine the oxidation rate of reduced DTT in solution with PM. However, the traditional DTT assay suffers from poor time resolution, loss of reactive species during sampling, and high limit of detection. Recently, a new DTT assay was developed that couples a Particle-Into-Liquid-Sampler with microfluidic-electrochemical detection. This 'on-line' system allows high temporal resolution monitoring of PM reactivity with improved detection limits. This study reports on a laboratory comparison of the traditional and on-line DTT approaches. An urban dust sample was aerosolized in a laboratory test chamber at three atmospherically-relevant concentrations. The on-line system gave a stronger correlation between DTT consumption rate and PM mass (R 2 = 0.69) than the traditional method (R 2 = 0.40) and increased precision at high temporal resolution, compared to the traditional method.

  14. Small-Scale Spray Releases: Additional Aerosol Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Schonewill, Philip P.; Gauglitz, Phillip A.; Kimura, Marcia L.; Brown, G. N.; Mahoney, Lenna A.; Tran, Diana N.; Burns, Carolyn A.; Kurath, Dean E.

    2013-08-01

    One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. To expand the data set upon which the WTP accident and safety analyses were based, an aerosol spray leak testing program was conducted by Pacific Northwest National Laboratory (PNNL). PNNL’s test program addressed two key technical areas to improve the WTP methodology (Larson and Allen 2010). The first technical area was to quantify the role of slurry particles in small breaches where slurry particles may plug the hole and prevent high-pressure sprays. The results from an effort to address this first technical area can be found in Mahoney et al. (2012a). The second technical area was to determine aerosol droplet size distribution and total droplet volume from prototypic breaches and fluids, including sprays from larger breaches and sprays of slurries for which literature data are largely absent. To address the second technical area, the testing program collected aerosol generation data at two scales, commonly referred to as small-scale and large-scale. The small-scale testing and resultant data are described in Mahoney et al. (2012b) and the large-scale testing and resultant data are presented in Schonewill et al. (2012). In tests at both scales, simulants were used to mimic the

  15. Small-Scale Spray Releases: Initial Aerosol Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Mahoney, Lenna A.; Gauglitz, Phillip A.; Kimura, Marcia L.; Brown, Garrett N.; Kurath, Dean E.; Buchmiller, William C.; Smith, Dennese M.; Blanchard, Jeremy; Song, Chen; Daniel, Richard C.; Wells, Beric E.; Tran, Diana N.; Burns, Carolyn A.

    2013-05-29

    One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty due to extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches where the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high-pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic breaches and fluids, specifically including sprays from larger breaches with slurries where data from the literature are scarce. To address these technical areas, small- and large-scale test stands were constructed and operated with simulants to determine aerosol release fractions and net generation rates from a range of breach sizes and geometries. The properties of the simulants represented the range of properties expected in the WTP process streams and included water, sodium salt solutions, slurries containing boehmite or gibbsite, and a hazardous chemical simulant. The effect of antifoam agents was assessed with most of the simulants. Orifices included round holes and

  16. Small-Scale Spray Releases: Initial Aerosol Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Mahoney, Lenna A.; Gauglitz, Phillip A.; Kimura, Marcia L.; Brown, Garrett N.; Kurath, Dean E.; Buchmiller, William C.; Smith, Dennese M.; Blanchard, Jeremy; Song, Chen; Daniel, Richard C.; Wells, Beric E.; Tran, Diana N.; Burns, Carolyn A.

    2012-11-01

    One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty due to extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches where the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high-pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic breaches and fluids, specifically including sprays from larger breaches with slurries where data from the literature are scarce. To address these technical areas, small- and large-scale test stands were constructed and operated with simulants to determine aerosol release fractions and generation rates from a range of breach sizes and geometries. The properties of the simulants represented the range of properties expected in the WTP process streams and included water, sodium salt solutions, slurries containing boehmite or gibbsite, and a hazardous chemical simulant. The effect of anti-foam agents was assessed with most of the simulants. Orifices included round holes and

  17. PHEBUS on-line aerosol monitor development test program

    International Nuclear Information System (INIS)

    Sprenger, M.H.; Pentecost, C.G.

    1992-03-01

    EG ampersand G Idaho, Inc. developed an on-line aerosol monitor (OLAM) for the French PHEBUS Fission Product Project. Part of the development was to manufacture and test an OLAM prototype. This report presents the results of the testing which determined the mechanical integrity of the monitor at operating temperature and pressure and performed a preliminary test of the optical system. A series of twenty different tests was conducted during the prototype testing sequence. Since no leaks were detected, the OLAM demonstrated that it could provide a pressure boundary at required test conditions. The optical and electrical system also proved its integrity by exceeding the design requirement of less than 105 optical signal drift during an actual two-hour test sequence

  18. Kinetics, Mechanism, and Secondary Organic Aerosol Yield of Aqueous Phase Photo-oxidation of α-Pinene Oxidation Products.

    Science.gov (United States)

    Aljawhary, Dana; Zhao, Ran; Lee, Alex K Y; Wang, Chen; Abbatt, Jonathan P D

    2016-03-10

    Formation of secondary organic aerosol (SOA) involves atmospheric oxidation of volatile organic compounds (VOCs), the majority of which are emitted from biogenic sources. Oxidation can occur not only in the gas-phase but also in atmospheric aqueous phases such as cloudwater and aerosol liquid water. This study explores for the first time the aqueous-phase OH oxidation chemistry of oxidation products of α-pinene, a major biogenic VOC species emitted to the atmosphere. The kinetics, reaction mechanisms, and formation of SOA compounds in the aqueous phase of two model compounds, cis-pinonic acid (PIN) and tricarballylic acid (TCA), were investigated in the laboratory; TCA was used as a surrogate for 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA), a known α-pinene oxidation product. Aerosol time-of-flight chemical ionization mass spectrometry (Aerosol-ToF-CIMS) was used to follow the kinetics and reaction mechanisms at the molecular level. Room-temperature second-order rate constants of PIN and TCA were determined to be 3.3 (± 0.5) × 10(9) and 3.1 (± 0.2) × 10(8) M(-1) s(-1), respectively, from which were estimated their condensed-phase atmospheric lifetimes. Aerosol-ToF-CIMS detected a large number of products leading to detailed reaction mechanisms for PIN and MBTCA. By monitoring the particle size distribution after drying, the amount of SOA material remaining in the particle phase was determined. An aqueous SOA yield of 40 to 60% was determined for PIN OH oxidation. Although recent laboratory studies have focused primarily on aqueous-phase processing of isoprene-related compounds, we demonstrate that aqueous formation of SOA materials also occurs from monoterpene oxidation products, thus representing an additional source of biogenically driven aerosol formation.

  19. Large-Scale Spray Releases: Initial Aerosol Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Schonewill, Philip P.; Gauglitz, Phillip A.; Bontha, Jagannadha R.; Daniel, Richard C.; Kurath, Dean E.; Adkins, Harold E.; Billing, Justin M.; Burns, Carolyn A.; Davis, James M.; Enderlin, Carl W.; Fischer, Christopher M.; Jenks, Jeromy WJ; Lukins, Craig D.; MacFarlan, Paul J.; Shutthanandan, Janani I.; Smith, Dennese M.

    2012-12-01

    One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty due to extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches where the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high-pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic breaches and fluids, specifically including sprays from larger breaches with slurries where data from the literature are scarce. To address these technical areas, small- and large-scale test stands were constructed and operated with simulants to determine aerosol release fractions and generation rates from a range of breach sizes and geometries. The properties of the simulants represented the range of properties expected in the WTP process streams and included water, sodium salt solutions, slurries containing boehmite or gibbsite, and a hazardous chemical simulant. The effect of anti-foam agents was assessed with most of the simulants. Orifices included round holes and

  20. Effect of relative humidity on growth of sodium oxide aerosols

    International Nuclear Information System (INIS)

    Sundarajan, A.R.; Mitragotri, D.S.; Mukunda Rao, S.R.

    1982-01-01

    Behavior of aerosol resulting from sodium fires in a closed vessel is investigated and the changes in the particle size distribution of the aerosol due to coagulation and humidity have been studied. The initial mass concentration is in the range of 80 -- 500 mg/m 3 and the relative humidity is varied between 50 to 98%. The initial size of the released aerosol is found to be 0.9 μm. Equilibrium diameters of particles growing in humid air have been computed for various humidity levels using water activity of sodium hydroxide. Both theoretical and experimental results have yielded growth ratios of about 3 at about 95% relative humidity. It is recommended that the computer codes dealing with aerosol coagulation behavior in reactor containment should include an appropriate humidity-growth function. (author)

  1. Fission product aerosol removal test by containment spray under accident management conditions (3)

    International Nuclear Information System (INIS)

    Watanabe, Atsushi; Nagasaka, Hideo; Yokobori, Seiichi; Akinaga, Makoto

    2000-01-01

    In order to demonstrate the effective FP aerosol removal by containment spray under Japanese AM conditions, two system integral tests and two separate effect tests were carried out using a full-height simulation test facility. In case of PWR LOCA, aerosol concentration in the upper containment vessel decreased even under low spray flow rate. In case of BWR LOCA with water injection into RPV, the aerosol concentration in the entire vessel also decreased rapidly after aerosol supply stopping. In both cases, the removal rate estimated from the NUREG-1465 was coincided with test results. The aerosol washing effect by spray was confirmed to be predominant by conducting suppression chamber isolation test. It turned out that the effect of aerosol solubility and density on aerosol removal by spray was quite small by conducting insoluble aerosol injection test. After the modification of aerosol removal model by the spray and hygroscopic aerosol model in original MELCOR 1.8.4, calculated aerosol concentration transient in the containment vessel agreed well with the test data. (author)

  2. High formation of secondary organic aerosol from the photo-oxidation of toluene

    OpenAIRE

    L. Hildebrandt; N. M. Donahue; S. N. Pandis

    2009-01-01

    Toluene and other aromatics have long been viewed as the dominant anthropogenic secondary organic aerosol (SOA) precursors, but the SOA mass yields from toluene reported in previous studies vary widely. Experiments conducted in the Carnegie Mellon University environmental chamber to study SOA formation from the photo-oxidation of toluene show significantly larger SOA production than parameterizations employed in current air-quality models. Aerosol mass yields depend on experimental co...

  3. A new oxidation flow reactor for measuring secondary aerosol formation of rapidly changing emission sources

    Science.gov (United States)

    Simonen, Pauli; Saukko, Erkka; Karjalainen, Panu; Timonen, Hilkka; Bloss, Matthew; Aakko-Saksa, Päivi; Rönkkö, Topi; Keskinen, Jorma; Dal Maso, Miikka

    2017-04-01

    Oxidation flow reactors (OFRs) or environmental chambers can be used to estimate secondary aerosol formation potential of different emission sources. Emissions from anthropogenic sources, such as vehicles, often vary on short timescales. For example, to identify the vehicle driving conditions that lead to high potential secondary aerosol emissions, rapid oxidation of exhaust is needed. However, the residence times in environmental chambers and in most oxidation flow reactors are too long to study these transient effects ( ˜ 100 s in flow reactors and several hours in environmental chambers). Here, we present a new oxidation flow reactor, TSAR (TUT Secondary Aerosol Reactor), which has a short residence time ( ˜ 40 s) and near-laminar flow conditions. These improvements are achieved by reducing the reactor radius and volume. This allows studying, for example, the effect of vehicle driving conditions on the secondary aerosol formation potential of the exhaust. We show that the flow pattern in TSAR is nearly laminar and particle losses are negligible. The secondary organic aerosol (SOA) produced in TSAR has a similar mass spectrum to the SOA produced in the state-of-the-art reactor, PAM (potential aerosol mass). Both reactors produce the same amount of mass, but TSAR has a higher time resolution. We also show that TSAR is capable of measuring the secondary aerosol formation potential of a vehicle during a transient driving cycle and that the fast response of TSAR reveals how different driving conditions affect the amount of formed secondary aerosol. Thus, TSAR can be used to study rapidly changing emission sources, especially the vehicular emissions during transient driving.

  4. Inhalation toxicology of industrial plutonium and uranium oxide aerosols I. Physical chemical characterization

    International Nuclear Information System (INIS)

    Eidson, A.F.; Mewhinney, J.A.

    1978-01-01

    In the fabrication of mixed plutonium and uranium oxide fuel, large quantities of dry powders are processed, causing dusty conditions in glove box enclosures. Inadvertent loss of glove box integrity or failure of air filter systems can lead to human inhalation exposure. Powdered samples and aerosol samples of these materials obtained during two fuel fabrication process steps have been obtained. A regimen of physical chemical tests of properties of these materials has been employed to identify physical chemical properties which may influence their biological behavior and dosimetry. Materials to be discussed are 750 deg. C heat-treated, mixed uranium and plutonium oxides obtained from the ball milling operation and 1750 deg. C heat-treated, mixed uranium and plutonium oxides obtained from the centerless grinding of fuel pellets. Results of x-ray diffraction studies have shown that the powder generated by the centerless grinding of fuel pellets is best described as a solid solution of UO x and PuO x consistent with its temperature history. In vitro dissolution studies of both mixed oxide materials indicate a generally similar dissolution rate for both materials. In one solvent, the material with the higher temperature history dissolves more rapidly. The x-ray diffraction and in vitro dissolution results as well as preliminary results of x-ray photoelectron spectroscopic analyses will be compared and the implications for the associated biological studies will be discussed. (author)

  5. The design of an aerosol test tunnel for occupational hygiene investigations

    Science.gov (United States)

    Blackford, D. B.; Heighington, K.

    An aerosol test tunnel which provides large working sections is described and its performance evaluated. Air movement within the tunnel is achieved with a powerful D.C. motor and centrifugal fan. Test dusts are dispersed and injected into the tunnel by means of an aerosol generator. A unique divertor valve allows aerosol laden air to be either cleaned by a commercial pulse jet filtration unit or recycled around the tunnel to obtain a high aerosol concentration. The tunnel instrumentation is managed by a microcomputer which automatically controls the airspeed and aerosol concentration.

  6. Carbon oxidation state as a metric for describing the chemistry of atmospheric organic aerosol

    Energy Technology Data Exchange (ETDEWEB)

    Massachusetts Institute of Technology; Kroll, Jesse H.; Donahue, Neil M.; Jimenez, Jose L.; Kessler, Sean H.; Canagaratna, Manjula R.; Wilson, Kevin R.; Altieri, Katye E.; Mazzoleni, Lynn R.; Wozniak, Andrew S.; Bluhm, Hendrik; Mysak, Erin R.; Smith, Jared D.; Kolb, Charles E.; Worsnop, Douglas R.

    2010-11-05

    A detailed understanding of the sources, transformations, and fates of organic species in the environment is crucial because of the central roles that organics play in human health, biogeochemical cycles, and Earth's climate. However, such an understanding is hindered by the immense chemical complexity of environmental mixtures of organics; for example, atmospheric organic aerosol consists of at least thousands of individual compounds, all of which likely evolve chemically over their atmospheric lifetimes. Here we demonstrate the utility of describing organic aerosol (and other complex organic mixtures) in terms of average carbon oxidation state (OSC), a quantity that always increases with oxidation, and is readily measured using state-of-the-art analytical techniques. Field and laboratory measurements of OSC , using several such techniques, constrain the chemical properties of the organics and demonstrate that the formation and evolution of organic aerosol involves simultaneous changes to both carbon oxidation state and carbon number (nC).

  7. Test Concept for Advanced Oxidation Techniques

    DEFF Research Database (Denmark)

    Bennedsen, Lars Rønn; Søgaard, Erik Gydesen; Mortensen, Lars

    advanced on-site oxidation tests. The remediation techniques included are electrochemical oxidation, photochemical/photocatalytic oxidation, ozone, hydrogen peroxide, permanganate, and persulfate among others. A versatile construction of the mobile test unit makes it possible to combine different...

  8. Characterization of aerosol photooxidation flow reactors: heterogeneous oxidation, secondary organic aerosol formation and cloud condensation nuclei activity measurements

    Directory of Open Access Journals (Sweden)

    A. T. Lambe

    2011-03-01

    Full Text Available Motivated by the need to develop instrumental techniques for characterizing organic aerosol aging, we report on the performance of the Toronto Photo-Oxidation Tube (TPOT and Potential Aerosol Mass (PAM flow tube reactors under a variety of experimental conditions. The PAM system was designed with lower surface-area-to-volume (SA/V ratio to minimize wall effects; the TPOT reactor was designed to study heterogeneous aerosol chemistry where wall loss can be independently measured. The following studies were performed: (1 transmission efficiency measurements for CO2, SO2, and bis(2-ethylhexyl sebacate (BES particles, (2 H2SO4 yield measurements from the oxidation of SO2, (3 residence time distribution (RTD measurements for CO2, SO2, and BES particles, (4 aerosol mass spectra, O/C and H/C ratios, and cloud condensation nuclei (CCN activity measurements of BES particles exposed to OH radicals, and (5 aerosol mass spectra, O/C and H/C ratios, CCN activity, and yield measurements of secondary organic aerosol (SOA generated from gas-phase OH oxidation of m-xylene and α-pinene. OH exposures ranged from (2.0 ± 1.0 × 1010 to (1.8 ± 0.3 × 1012 molec cm−3 s. Where applicable, data from the flow tube reactors are compared with published results from the Caltech smog chamber. The TPOT yielded narrower RTDs. However, its transmission efficiency for SO2 was lower than that for the PAM. Transmission efficiency for BES and H2SO4 particles was size-dependent and was similar for the two flow tube designs. Oxidized BES particles had similar O/C and H/C ratios and CCN activity at OH exposures greater than 1011 molec cm−3 s, but different CCN activity at lower OH exposures. The O/C ratio, H/C ratio, and yield of m-xylene and α-pinene SOA was strongly affected by reactor design and

  9. Physicochemical characterization of Capstone depleted uranium aerosols III: morphologic and chemical oxide analyses.

    Science.gov (United States)

    Krupka, Kenneth M; Parkhurst, Mary Ann; Gold, Kenneth; Arey, Bruce W; Jenson, Evan D; Guilmette, Raymond A

    2009-03-01

    The impact of depleted uranium (DU) penetrators against an armored target causes erosion and fragmentation of the penetrators, the extent of which is dependent on the thickness and material composition of the target. Vigorous oxidation of the DU particles and fragments creates an aerosol of DU oxide particles and DU particle agglomerations combined with target materials. Aerosols from the Capstone DU aerosol study, in which vehicles were perforated by DU penetrators, were evaluated for their oxidation states using x-ray diffraction (XRD), and particle morphologies were examined using scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS). The oxidation state of a DU aerosol is important as it offers a clue to its solubility in lung fluids. The XRD analysis showed that the aerosols evaluated were a combination primarily of U3O8 (insoluble) and UO3 (relatively more soluble) phases, though intermediate phases resembling U4O9 and other oxides were prominent in some samples. Analysis of particle residues in the micrometer-size range by SEM/EDS provided microstructural information such as phase composition and distribution, fracture morphology, size distribution, and material homogeneity. Observations from SEM analysis show a wide variability in the shapes of the DU particles. Some of the larger particles were spherical, occasionally with dendritic or lobed surface structures. Others appear to have fractures that perhaps resulted from abrasion and comminution, or shear bands that developed from plastic deformation of the DU material. Amorphous conglomerates containing metals other than uranium were also common, especially with the smallest particle sizes. A few samples seemed to contain small bits of nearly pure uranium metal, which were verified by EDS to have a higher uranium content exceeding that expected for uranium oxides. Results of the XRD and SEM/EDS analyses were used in other studies described in this issue of Health Physics to interpret the

  10. Physicochemical Characterization of Capstone Depleted Uranium Aerosols III: Morphologic and Chemical Oxide Analyses

    International Nuclear Information System (INIS)

    Krupka, Kenneth M.; Parkhurst, MaryAnn; Gold, Kenneth; Arey, Bruce W.; Jenson, Evan D.; Guilmette, Raymond A.

    2009-01-01

    The impact of depleted uranium (DU) penetrators against an armored target causes erosion and fragmentation of the penetrators, the extent of which is dependent on the thickness and material composition of the target. Vigorous oxidation of the DU particles and fragments creates an aerosol of DU oxide particles and DU particle agglomerations combined with target materials. Aerosols from the Capstone DU aerosol study, in which vehicles were perforated by DU penetrators, were evaluated for their oxidation states using X-ray diffraction (XRD) and particle morphologies using scanning electron microscopy/energy dispersive spectrometry (SEM/EDS). The oxidation state of a DU aerosol is important as it offers a clue to its solubility in lung fluids. The XRD analysis showed that the aerosols evaluated were a combination primarily of U3O8 (insoluble) and UO3 (relatively more soluble) phases, though intermediate phases resembling U4O9 and other oxides were prominent in some samples. Analysis of particle residues in the micrometer-size range by SEM/EDS provided microstructural information such as phase composition and distribution, fracture morphology, size distribution, and material homogeneity. Observations from SEM analysis show a wide variability in the shapes of the DU particles. Some of the larger particles appear to have been fractured (perhaps as a result of abrasion and comminution); others were spherical, occasionally with dendritic or lobed surface structures. Amorphous conglomerates containing metals other than uranium were also common, especially with the smallest particle sizes. A few samples seemed to contain small chunks of nearly pure uranium metal, which were verified by EDS to have a higher uranium content exceeding that expected for uranium oxides. Results of the XRD and SEM/EDS analyses were used in other studies described in this issue of The Journal of Health Physics to interpret the results of lung solubility studies and in selecting input parameters for

  11. Description of test facilities bound to the research on sodium aerosols - some significant results

    Energy Technology Data Exchange (ETDEWEB)

    Dolias, M; Lafon, A; Vidard, M; Schaller, K H [DRNR/STRS - Centre de Cadarache, Saint-Paul-lez-Durance (France)

    1977-01-01

    This communication is dedicated to the description of the CEA (French Atomic Energy Authority) testing located at CADARACHE and which are utilized for the study of sodium aerosols behavior. These testing loops are necessary for studying the operating of equipment such as filters, sodium vapour traps, condensers and separators. It is also possible to study the effect of characteristics parameters on formation, coagulation and carrying away of sodium aerosols in the cover gas. Sodium aerosols deposits in a vertical annular space configuration with a cold area in its upper part are also studied. Some significant results emphasize the importance of operating conditions on the formation of aerosols. (author)

  12. Performance Testing of Tracer Gas and Tracer Aerosol Detectors for use in Radionuclide NESHAP Compliance Testing

    Energy Technology Data Exchange (ETDEWEB)

    Fuehne, David Patrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lattin, Rebecca Renee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-06-28

    The Rad-NESHAP program, part of the Air Quality Compliance team of LANL’s Compliance Programs group (EPC-CP), and the Radiation Instrumentation & Calibration team, part of the Radiation Protection Services group (RP-SVS), frequently partner on issues relating to characterizing air flow streams. This memo documents the most recent example of this partnership, involving performance testing of sulfur hexafluoride detectors for use in stack gas mixing tests. Additionally, members of the Rad-NESHAP program performed a functional trending test on a pair of optical particle counters, comparing results from a non-calibrated instrument to a calibrated instrument. Prior to commissioning a new stack sampling system, the ANSI Standard for stack sampling requires that the stack sample location must meet several criteria, including uniformity of tracer gas and aerosol mixing in the air stream. For these mix tests, tracer media (sulfur hexafluoride gas or liquid oil aerosol particles) are injected into the stack air stream and the resulting air concentrations are measured across the plane of the stack at the proposed sampling location. The coefficient of variation of these media concentrations must be under 20% when evaluated over the central 2/3 area of the stack or duct. The instruments which measure these air concentrations must be tested prior to the stack tests in order to ensure their linear response to varying air concentrations of either tracer gas or tracer aerosol. The instruments used in tracer gas and aerosol mix testing cannot be calibrated by the LANL Standards and Calibration Laboratory, so they would normally be sent off-site for factory calibration by the vendor. Operational requirements can prevent formal factory calibration of some instruments after they have been used in hazardous settings, e.g., within a radiological facility with potential airborne contamination. The performance tests described in this document are intended to demonstrate the reliable

  13. Removal of nitrogen oxides, 106RuO4 vapors and radioactive aerosols from the gas originating in radioactive wastes solidification

    International Nuclear Information System (INIS)

    Kepak, F.; Pecak, V.; Uher, E.; Kanka, J.; Koutova, S.; Matous, V.

    1985-01-01

    Procedures and equipment for the disposal of nitrogen oxides, RuO 4 vapors and radioactive aerosols of 90 Sr, 137 Cs, 60 Co and 125 Sb contained in the gas generated in the solidification of high- and intermediate-level radioactive wastes were tested on models. Nitrogen oxides were disposed of by absorption and chemical decomposition in various solutions of which the best results gave solutions of ammonium salts. Absorption in solutions, physical and chemical sorption on inorganic sorbents were tested for the disposal of RuO 4 . Aerosols were disposed of by absorption in absorption media with subsequent filtration. Of fibrous filter materials, Czechoslovak AEROS-2 and RA-2 filter papers were proven in the tests. Attention was also devoted to granular filter materials of which silica gel was chosen. On the basis of laboratory tests a multi-step treatment system was designed which consists of a condenser, a nitrogen oxide absorber, a liquid aerosol separator, absorption columns and aerosol filters. The whole system has been manufactured on pilot plant scale and the different parts are being produced. (Z.M.)

  14. Laboratory investigation of photochemical oxidation of organic aerosol from wood fires 2: analysis of aerosol mass spectrometer data

    Directory of Open Access Journals (Sweden)

    A. P. Grieshop

    2009-03-01

    Full Text Available Experiments were conducted to investigate the effects of photo-oxidation on organic aerosol (OA in dilute wood smoke by exposing emissions from soft- and hard-wood fires to UV light in a smog chamber. This paper focuses on changes in OA composition measured using a unit-mass-resolution quadrupole Aerosol Mass Spectrometer (AMS. The results highlight how photochemical processing can lead to considerable evolution of the mass, volatility and level of oxygenation of biomass-burning OA. Photochemical oxidation produced substantial new OA, more than doubling the OA mass after a few hours of aging under typical summertime conditions. Aging also decreased the volatility of the OA and made it progressively more oxygenated. The results also illustrate strengths of, and challenges with, using AMS data for source apportionment analysis. For example, the mass spectra of fresh and aged BBOA are distinct from fresh motor-vehicle emissions. The mass spectra of the secondary OA produced from aging wood smoke are very similar to those of the oxygenated OA (OOA that dominates ambient AMS datasets, further reinforcing the connection between OOA and OA formed from photo-chemistry. In addition, aged wood smoke spectra are similar to those from OA created by photo-oxidizing dilute diesel exhaust. This demonstrates that the OOA observed in the atmosphere can be produced by photochemical aging of dilute emissions from different types of combustion systems operating on fuels with modern or fossil carbon. Since OOA is frequently the dominant component of ambient OA, the similarity of spectra of aged emissions from different sources represents an important challenge for AMS-based source apportionment studies.

  15. Size-resolved mass concentrations of iron oxide aerosols and size-resolved number concentrations of iron oxide aerosols collected from King Air aircraft in Yellow Sea and East China Sea from 2013-02-14 to 2013-03-10 (NCEI Accession 0162201)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains size-resolved mass concentrations of iron oxide aerosols and size-resolved number concentrations of iron oxide aerosols, measured using the...

  16. Secondary organic aerosols over oceans via oxidation of isoprene and monoterpenes from Arctic to Antarctic.

    Science.gov (United States)

    Hu, Qi-Hou; Xie, Zhou-Qing; Wang, Xin-Ming; Kang, Hui; He, Quan-Fu; Zhang, Pengfei

    2013-01-01

    Isoprene and monoterpenes are important precursors of secondary organic aerosols (SOA) in continents. However, their contributions to aerosols over oceans are still inconclusive. Here we analyzed SOA tracers from isoprene and monoterpenes in aerosol samples collected over oceans during the Chinese Arctic and Antarctic Research Expeditions. Combined with literature reports elsewhere, we found that the dominant tracers are the oxidation products of isoprene. The concentrations of tracers varied considerably. The mean average values were approximately one order of magnitude higher in the Northern Hemisphere than in the Southern Hemisphere. High values were generally observed in coastal regions. This phenomenon was ascribed to the outflow influence from continental sources. High levels of isoprene could emit from oceans and consequently have a significant impact on marine SOA as inferred from isoprene SOA during phytoplankton blooms, which may abruptly increase up to 95 ng/m³ in the boundary layer over remote oceans.

  17. Results and code prediction comparisons of lithium-air reaction and aerosol behavior tests

    International Nuclear Information System (INIS)

    Jeppson, D.W.

    1986-03-01

    The Hanford Engineering Development Laboratory (HEDL) Fusion Safety Support Studies include evaluation of potential safety and environmental concerns associated with the use of liquid lithium as a breeder and coolant for fusion reactors. Potential mechanisms for volatilization and transport of radioactive metallic species associated with breeder materials are of particular interest. Liquid lithium pool-air reaction and aerosol behavior tests were conducted with lithium masses up to 100 kg within the 850-m 3 containment vessel in the Containment Systems Test Facility. Lithium-air reaction rates, aerosol generation rates, aerosol behavior and characterization, as well as containment atmosphere temperature and pressure responses were determined. Pool-air reaction and aerosol behavior test results were compared with computer code calculations for reaction rates, containment atmosphere response, and aerosol behavior. The volatility of potentially radioactive metallic species from a lithium pool-air reaction was measured. The response of various aerosol detectors to the aerosol generated was determined. Liquid lithium spray tests in air and in nitrogen atmospheres were conducted with lithium temperatures of about 427 0 and 650 0 C. Lithium reaction rates, containment atmosphere response, and aerosol generation and characterization were determined for these spray tests

  18. Experimental Characterization and Hygroscopicity Determination of Secondary Aerosol from D5 Cyclic Siloxane Oxidation

    Science.gov (United States)

    Stanier, C. O.; Janechek, N. J.; Bryngelson, N.; Marek, R. F.; Lersch, T.; Bunker, K.; Casuccio, G.; Brune, W. H.; Hornbuckle, K. C.

    2017-12-01

    Cyclic volatile methyl siloxanes are anthropogenic chemicals present in personal care products such as antiperspirants and lotions. These are volatile chemicals that are readily released into the atmosphere by product use. Due to their emission and relatively slow kinetics of their major transformation pathway, reaction with hydroxyl radicals (OH), these compounds are present in high concentrations in indoor environments and widespread in outdoor environments. Cyclic siloxane reaction with OH can lead to secondary organic aerosols, and due to the widespread prevalence of the parent compounds, may be an important source of ambient aerosols. Atmospheric aerosols have important influences to the climate by affecting the radiative balance and by serving as cloud condensation nuclei (CCN) which influence clouds. While the parent compounds have been well-studied, the oxidation products have received much less attention, with almost no ambient measurements or experimental physical property data. We report physical properties of aerosols generated by reacting the cyclic siloxane D5 with OH using a Potential Aerosol Mass (PAM) photochemical chamber. The particles were characterized by SMPS, imaging and elemental analysis using both Transmission Electron Microscopy and Scanning Transmission Electron Microscopy equipped with Energy Dispersive X-ray Spectroscopy systems (TEM-EDS and STEM-EDS), volatility measurements using Volatility Tandem Differential Mobility Analyzer (V-TDMA), and hygroscopicity measurements to determine CCN potential using a Droplet Measurement Technologies Cloud Condensation Nuclei Counter (DMT-CCN). Aerosol yield sensitivity to D5 and OH concentrations, residence time, and seed aerosols were analyzed. TEM-EDS and STEM-EDS analysis show spherical particle morphology with elemental composition consistent with aerosols derived from cyclic siloxane sources. Measured aerosol yields were 20-50% with typical aerosol concentrations 300,000 particles cm-3, up to

  19. Secondary organic aerosol from VOC mixtures in an oxidation flow reactor

    Science.gov (United States)

    Ahlberg, Erik; Falk, John; Eriksson, Axel; Holst, Thomas; Brune, William H.; Kristensson, Adam; Roldin, Pontus; Svenningsson, Birgitta

    2017-07-01

    The atmospheric organic aerosol is a tremendously complex system in terms of chemical content. Models generally treat the mixtures as ideal, something which has been questioned owing to model-measurement discrepancies. We used an oxidation flow reactor to produce secondary organic aerosol (SOA) mixtures containing oxidation products of biogenic (α-pinene, myrcene and isoprene) and anthropogenic (m-xylene) volatile organic compounds (VOCs). The resulting volume concentration and chemical composition was measured using a scanning mobility particle sizer (SMPS) and a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS), respectively. The SOA mass yield of the mixtures was compared to a partitioning model constructed from single VOC experiments. The single VOC SOA mass yields with no wall-loss correction applied are comparable to previous experiments. In the mixtures containing myrcene a higher yield than expected was produced. We attribute this to an increased condensation sink, arising from myrcene producing a significantly higher number of nucleation particles compared to the other precursors. Isoprene did not produce much mass in single VOC experiments but contributed to the mass of the mixtures. The effect of high concentrations of isoprene on the OH exposure was found to be small, even at OH reactivities that previously have been reported to significantly suppress OH exposures in oxidation flow reactors. Furthermore, isoprene shifted the particle size distribution of mixtures towards larger sizes, which could be due to a change in oxidant dynamics inside the reactor.

  20. High formation of secondary organic aerosol from the photo-oxidation of toluene

    Directory of Open Access Journals (Sweden)

    L. Hildebrandt

    2009-05-01

    Full Text Available Toluene and other aromatics have long been viewed as the dominant anthropogenic secondary organic aerosol (SOA precursors, but the SOA mass yields from toluene reported in previous studies vary widely. Experiments conducted in the Carnegie Mellon University environmental chamber to study SOA formation from the photo-oxidation of toluene show significantly larger SOA production than parameterizations employed in current air-quality models. Aerosol mass yields depend on experimental conditions: yields are higher under higher UV intensity, under low-NOx conditions and at lower temperatures. The extent of oxidation of the aerosol also varies with experimental conditions, consistent with ongoing, progressive photochemical aging of the toluene SOA. Measurements using a thermodenuder system suggest that the aerosol formed under high- and low-NOx conditions is semi-volatile. These results suggest that SOA formation from toluene depends strongly on ambient conditions. An approximate parameterization is proposed for use in air-quality models until a more thorough treatment accounting for the dynamic nature of this system becomes available.

  1. LMFBR source term experiments in the Fuel Aerosol Simulant Test (FAST) facility

    International Nuclear Information System (INIS)

    Petrykowski, J.C.; Longest, A.W.

    1985-01-01

    The transport of uranium dioxide (UO 2 ) aerosol through liquid sodium was studied in a series of ten experiments in the Fuel Aerosol Simulant Test (FAST) facility at Oak Ridge National Laboratory (ORNL). The experiments were designed to provide a mechanistic basis for evaluating the radiological source term associated with a postulated, energetic core disruptive accident (CDA) in a liquid metal fast breeder reactor (LMFBR). Aerosol was generated by capacitor discharge vaporization of UO 2 pellets which were submerged in a sodium pool under an argon cover gas. Measurements of the pool and cover gas pressures were used to study the transport of aerosol contained by vapor bubbles within the pool. Samples of cover gas were filtered to determine the quantity of aerosol released from the pool. The depth at which the aerosol was generated was found to be the most critical parameter affecting release. The largest release was observed in the baseline experiment where the sample was vaporized above the sodium pool. In the nine ''undersodium'' experiments aerosol was generated beneath the surface of the pool at depths varying from 30 to 1060 mm. The mass of aerosol released from the pool was found to be a very small fraction of the original specimen. It appears that the bulk of aerosol was contained by bubbles which collapsed within the pool. 18 refs., 11 figs., 4 tabs

  2. Evaporative oxidation treatability test report

    International Nuclear Information System (INIS)

    1995-04-01

    In 1992, Congress passed the Federal Facilities Compliance Act that requires the U.S. Department of Energy (DOE) to treat and dispose of its mixed waste in accordance with the Resource Conservation and Recovery Act (RCRA) land disposal restrictions (LDRs). In response to the need for mixed-waste treatment capacity where available off-site commercial treatment facilities do not exist or cannot be used, the DOE Albuquerque Operations Office (DOE-AL) organized a Treatment Selection Team to match mixed wastes with treatment options and develop a strategy for treatment of its mixed wastes. DOE-AL manages operations at nine sites with mixed-waste inventories. The Treatment Selection Team determined a need to develop mobile treatment capacity to treat wastes at the sites where the wastes are generated. Treatment processes used for mixed waste not only must address the hazardous component (i.e., meet LDRs) but also must contain the radioactive component in a form that allows final disposal while protecting workers, the public, and the environment. On the basis of recommendations of the Treatment Selection Team, DOE-AL assigned projects to the sites to bring mixed-waste treatment capacity on-line. The three technologies assigned to the DOE Grand Junction Projects Office (GJPO) are evaporative oxidation, thermal desorption, and treated wastewater evaporation. Rust Geotech, the DOE-GJPO prime contractor, was assigned to design and fabricate mobile treatment units (MTUs) for these three technologies and to deliver the MTUs to selected DOE-AL sites. To conduct treatability tests at the GJPO, Rust leased a pilot-scale evaporative oxidation unit from the Clemson Technical Center (CTC), Anderson, South Carolina. The purpose of this report is to document the findings and results of tests performed using this equipment

  3. Environmental health hazards of e-cigarettes and their components: Oxidants and copper in e-cigarette aerosols

    International Nuclear Information System (INIS)

    Lerner, Chad A.; Sundar, Isaac K.; Watson, Richard M.; Elder, Alison; Jones, Ryan; Done, Douglas; Kurtzman, Rachel; Ossip, Deborah J.; Robinson, Risa; McIntosh, Scott; Rahman, Irfan

    2015-01-01

    To narrow the gap in our understanding of potential oxidative properties associated with Electronic Nicotine Delivery Systems (ENDS) i.e. e-cigarettes, we employed semi-quantitative methods to detect oxidant reactivity in disposable components of ENDS/e-cigarettes (batteries and cartomizers) using a fluorescein indicator. These components exhibit oxidants/reactive oxygen species reactivity similar to used conventional cigarette filters. Oxidants/reactive oxygen species reactivity in e-cigarette aerosols was also similar to oxidant reactivity in cigarette smoke. A cascade particle impactor allowed sieving of a range of particle size distributions between 0.450 and 2.02 μm in aerosols from an e-cigarette. Copper, being among these particles, is 6.1 times higher per puff than reported previously for conventional cigarette smoke. The detection of a potentially cytotoxic metal as well as oxidants from e-cigarette and its components raises concern regarding the safety of e-cigarettes use and the disposal of e-cigarette waste products into the environment. - Highlights: • E-cigarettes disposal is associated with environmental health hazard/pollution. • Oxidants associated with electronic cigarette components and aerosols. • Metal copper and nanoparticles detected in electronic cigarette aerosols. • Environmental disposal of e-cigarettes components must be regulated with guidelines. - An electronic cigarette with disposable cartomizer exhibits oxidant reactivity similar to conventional cigarettes and releases copper and other particles associated with its aerosols

  4. Development of Aerosol Scrubbing Test Loop for Containment Filtered Venting System

    International Nuclear Information System (INIS)

    Lee, Doo Yong; Jung, Woo Young; Lee, Hyun Chul; Lee, Jong Chan; Kim, Gyu Tae

    2016-01-01

    The scrubber tank is filled with scrubbing water with the chemical additives. The droplet separator based on a cyclone is installed above the scrubbing water pool to remove the large droplets that may clog a metal fiber filter installed at the upper section of the scrubber tank. The outlet piping is connected from the scrubber tank to the molecular sieve to chemically remove the gaseous iodine. The aerosol as a particle is physically captured in the scrubbing water pool passing through the scrubbing nozzle as well as the metal fiber filter. The gaseous iodine such as molecular iodine as well as organic iodide is chemically removed in the scrubbing water pool and molecular sieve. The thermal-hydraulic as well as scrubbing performance for the CFVS should be verified with the experiments. The experiment can be divided into the filtration component based experiment and whole system based one. In this paper, the aerosol scrubbing test loop developed to test the thermal-hydraulic and aerosol scrubbing performance of the scrubbing nozzle with the scrubbing water pool is introduced. The aerosol scrubbing test loop has been developed as a part of the Korean CFVS project. In this loop, the filtration components such as the scrubbing nozzle submerged in the scrubbing water pool as well as the cyclone as droplet separator can be tested under the CFVS operating conditions. The aerosol scrubbing performance of the filtration components including pool scrubbing behavior can be tested with the aerosol generation and feeding system and aerosol measurement system.

  5. Development of Aerosol Scrubbing Test Loop for Containment Filtered Venting System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Doo Yong; Jung, Woo Young; Lee, Hyun Chul; Lee, Jong Chan; Kim, Gyu Tae [FNC Technology, Yongin (Korea, Republic of)

    2016-05-15

    The scrubber tank is filled with scrubbing water with the chemical additives. The droplet separator based on a cyclone is installed above the scrubbing water pool to remove the large droplets that may clog a metal fiber filter installed at the upper section of the scrubber tank. The outlet piping is connected from the scrubber tank to the molecular sieve to chemically remove the gaseous iodine. The aerosol as a particle is physically captured in the scrubbing water pool passing through the scrubbing nozzle as well as the metal fiber filter. The gaseous iodine such as molecular iodine as well as organic iodide is chemically removed in the scrubbing water pool and molecular sieve. The thermal-hydraulic as well as scrubbing performance for the CFVS should be verified with the experiments. The experiment can be divided into the filtration component based experiment and whole system based one. In this paper, the aerosol scrubbing test loop developed to test the thermal-hydraulic and aerosol scrubbing performance of the scrubbing nozzle with the scrubbing water pool is introduced. The aerosol scrubbing test loop has been developed as a part of the Korean CFVS project. In this loop, the filtration components such as the scrubbing nozzle submerged in the scrubbing water pool as well as the cyclone as droplet separator can be tested under the CFVS operating conditions. The aerosol scrubbing performance of the filtration components including pool scrubbing behavior can be tested with the aerosol generation and feeding system and aerosol measurement system.

  6. SECONDARY ORGANIC AEROSOL FORMATION FROM THE OXIDATION OF AROMATIC HYDROCARBONS IN THE PRESENCE OF DRY SUBMICRON AMMONIUM SULFATE AEROSOL

    Science.gov (United States)

    A laboratory study was conducted to examine formation of secondary organic aerosols. A smog chamber system was developed for studying gas-aerosol interactions in a dynamic flow reactor. These experiments were conducted to investigate the fate of gas and aerosol phase compounds ...

  7. Atmospheric oxidation of isoprene and 1,3-Butadiene: influence of aerosol acidity and Relative humidity on secondary organic aerosol

    Science.gov (United States)

    The effects of acidic seed aerosols on the formation of secondary organic aerosol (SOA)have been examined in a number of previous studies, several of which have observed strong linear correlations between the aerosol acidity (measured as nmol H+ per m3 air s...

  8. Adsorption and revaporisation studies of thin iodine oxide and CsI aerosol deposits from containment surface materials in LWRs

    Energy Technology Data Exchange (ETDEWEB)

    Tietze, S.; Foreman, M.; Ekberg, C. [Chalmers Univ. of Technology, Goeteborg (Sweden); Kaerkelae, T.; Auvinen, A.; Tapper, U.; Jokiniemi, J. [VTT Technical Research Centre of Finland, Espoo (Finland)

    2013-07-15

    During a severe nuclear accident released fission and radiolysis products can react with each other to form new species which might contribute to the volatile source term. Iodine will be released from UO2 fuel mainly in form as CsI aerosol particles and elemental iodine. Elemental iodine can react in gaseous phase with ozone to form solid iodine oxide aerosol particles (IOx). Within the AIAS-2 (Adsorption of Iodine Aerosols on Surfaces) project the interactions of IOx and CsI aerosols with common containment surface materials was investigated. Common surface materials in Swedish and Finnish LWRs are Teknopox Aqua V A paint films and metal surfaces such as Cu, Zn, Al and SS. Non-radioactive and {sup 131}I labelled aerosols were produced from a KI solution and ozone with a new facility designed and built at VTT Technical Research Centre of Finland. CsI aerosols were produced from a CsI solution with the same facility. A monolayer of the aerosols was deposited on the surfaces. The deposits were analysed with microscopic and spectroscopic measurement techniques to identify the chemical form of the deposits on the surfaces to identify if a chemical conversion on the different surface materials had occured. The revaporisation behaviour of the deposited aerosol particles from the different surface materials was studied under the influence of heat, humidity and gamma irradiation at Chalmers University of Technology, Sweden. Studies on the effects of humidity were performed using the FOMICAG facility, while heat and irradiation experiments were performed in a thermostated heating block and with a gammacell 22 with a dose rate of 14 kGy/h. The revaporisation losses were measured using a HPGe detector. The decomposition effect of the radiolysis product carbon monoxide was tested on IOx aerosols deposited on a glass fibre filter. Iodine oxide particles were produced at 50 deg. C, 100 deg. C and 120 deg. C and deposited on filter samples in order to study the chemical

  9. Adsorption and revaporisation studies of thin iodine oxide and CsI aerosol deposits from containment surface materials in LWRs

    International Nuclear Information System (INIS)

    Tietze, S.; Foreman, M.; Ekberg, C.; Kaerkelae, T.; Auvinen, A.; Tapper, U.; Jokiniemi, J.

    2013-07-01

    During a severe nuclear accident released fission and radiolysis products can react with each other to form new species which might contribute to the volatile source term. Iodine will be released from UO2 fuel mainly in form as CsI aerosol particles and elemental iodine. Elemental iodine can react in gaseous phase with ozone to form solid iodine oxide aerosol particles (IOx). Within the AIAS-2 (Adsorption of Iodine Aerosols on Surfaces) project the interactions of IOx and CsI aerosols with common containment surface materials was investigated. Common surface materials in Swedish and Finnish LWRs are Teknopox Aqua V A paint films and metal surfaces such as Cu, Zn, Al and SS. Non-radioactive and 131 I labelled aerosols were produced from a KI solution and ozone with a new facility designed and built at VTT Technical Research Centre of Finland. CsI aerosols were produced from a CsI solution with the same facility. A monolayer of the aerosols was deposited on the surfaces. The deposits were analysed with microscopic and spectroscopic measurement techniques to identify the chemical form of the deposits on the surfaces to identify if a chemical conversion on the different surface materials had occured. The revaporisation behaviour of the deposited aerosol particles from the different surface materials was studied under the influence of heat, humidity and gamma irradiation at Chalmers University of Technology, Sweden. Studies on the effects of humidity were performed using the FOMICAG facility, while heat and irradiation experiments were performed in a thermostated heating block and with a gammacell 22 with a dose rate of 14 kGy/h. The revaporisation losses were measured using a HPGe detector. The decomposition effect of the radiolysis product carbon monoxide was tested on IOx aerosols deposited on a glass fibre filter. Iodine oxide particles were produced at 50 deg. C, 100 deg. C and 120 deg. C and deposited on filter samples in order to study the chemical speciation of

  10. The composition of aerosols generated during a severe reactor accident: Experimental results from the Power Burst Facility Severe Fuel Damage Test 1-4

    International Nuclear Information System (INIS)

    Petti, D.A.; Hobbins, R.R.; Hagrman, D.L.

    1994-01-01

    Experimental results on fission product and aerosol release during the Power Burst Facility Severe Fuel Damages (SFD) Test 1-4 are examined to determine the composition of aerosols that would be generated during a severe reactor accident. The SFD 1-4 measured aerosol contained significant quantities of volatile fission products (VFPs) (cesium, iodine, tellurium), control materials (silver and cadmium), and structural materials (tin), indicating that fission product release, vaporization of control material, and release of tin from oxidized Zircaloy were all important aerosol sources. On average the aerosol composition is between one-quarter and one-half VFPs (especially cesium), with the remainder being control material (especially cadmium), and structural material (especially tin). Source term computer codes like CORSOR-M tend to overpredict the release of structural and control rod material relative to fission products by a factor of between 2 and 15 because the models do not account for relocation of molten control, fuel, and structural material during the degradation process, which tends to reduce the aerosol source. The results indicate that the aerosol generation in a severe reactor accident is intimately linked to the core degradation process. They recommend that these results be used to improve the models in source term computer codes

  11. Experimental and modelling studies of iodine oxide formation and aerosol behaviour relevant to nuclear reactor accidents

    International Nuclear Information System (INIS)

    Dickinson, S.; Auvinen, A.; Ammar, Y.; Bosland, L.; Clément, B.; Funke, F.; Glowa, G.; Kärkelä, T.; Powers, D.A.; Tietze, S.; Weber, G.; Zhang, S.

    2014-01-01

    Highlights: • Radiolytic reactions can influence iodine volatility following a nuclear accident. • Kinetic models have been developed based on atmospheric chemistry studies. • Properties of iodine oxide aerosols produced by radiation have been measured. • Decomposition of iodine oxides by the action of heat or radiation has been observed. - Abstract: Plant assessments have shown that iodine contributes significantly to the source term for a range of accident scenarios. Iodine has a complex chemistry that determines its chemical form and, consequently, its volatility in the containment. If volatile iodine species are formed by reactions in the containment, they will be subject to radiolytic reactions in the atmosphere, resulting in the conversion of the gaseous species into involatile iodine oxides, which may deposit on surfaces or re-dissolve in water pools. The concentration of airborne iodine in the containment will, therefore, be determined by the balance between the reactions contributing to the formation and destruction of volatile species, as well as by the physico-chemical properties of the iodine oxide aerosols which will influence their longevity in the atmosphere. This paper summarises the work that has been done in the framework of the EC SARNET (Severe Accident Research Network) to develop a greater understanding of the reactions of gaseous iodine species in irradiated air/steam atmospheres, and the nature and behaviour of the reaction products. This work has mainly been focussed on investigating the nature and behaviour of iodine oxide aerosols, but earlier work by members of the SARNET group on gaseous reaction rates is also discussed to place the more recent work into context

  12. Hygroscopicity of secondary organic aerosols formed by oxidation of cycloalkenes, monoterpenes, sesquiterpenes, and related compounds

    Directory of Open Access Journals (Sweden)

    V. Varutbangkul

    2006-01-01

    Full Text Available A series of experiments has been conducted in the Caltech indoor smog chamber facility to investigate the water uptake properties of aerosol formed by oxidation of various organic precursors. Secondary organic aerosol (SOA from simple and substituted cycloalkenes (C5-C8 is produced in dark ozonolysis experiments in a dry chamber (RH~5%. Biogenic SOA from monoterpenes, sesquiterpenes, and oxygenated terpenes is formed by photooxidation in a humid chamber (~50% RH. Using the hygroscopicity tandem differential mobility analyzer (HTDMA, we measure the diameter-based hygroscopic growth factor (GF of the SOA as a function of time and relative humidity. All SOA studied is found to be slightly hygroscopic, with smaller water uptake than that of typical inorganic aerosol substances. The aerosol water uptake increases with time early in the experiments for the cycloalkene SOA, but decreases with time for the sesquiterpene SOA. This behavior could indicate competing effects between the formation of more highly oxidized polar compounds (more hygroscopic, and formation of longer-chained oligomers (less hygroscopic. All SOA also exhibit a smooth water uptake with RH with no deliquescence or efflorescence. The water uptake curves are found to be fitted well with an empirical three-parameter functional form. The measured pure organic GF values at 85% RH are between 1.09–1.16 for SOA from ozonolysis of cycloalkenes, 1.01–1.04 for sesquiterpene photooxidation SOA, and 1.06–1.10 for the monoterpene and oxygenated terpene SOA. The GF of pure SOA (GForg in experiments in which inorganic seed aerosol is used is determined by assuming volume-weighted water uptake (Zdanovskii-Stokes-Robinson or 'ZSR' approach and using the size-resolved organic mass fraction measured by the Aerodyne Aerosol Mass Spectrometer. Knowing the water content associated with the inorganic fraction yields GForg values. However, for each precursor, the GForg values computed from different

  13. Charge distribution on plutonium-containing aerosols produced in mixed-oxide reactor fuel fabrication and the laboratory

    International Nuclear Information System (INIS)

    Yeh, H.C.; Newton, G.J.; Teague, S.V.

    1976-01-01

    The inhalation toxicity of potentially toxic aerosols may be affected by the electrostatic charge on the particles. Charge may influence the deposition site during inhalation and therefore its subsequent clearance and dose patterns. The electrostatic charge distributions on plutonium-containing aerosols were measured with a miniature, parallel plate, aerosol electrical mobility spectrometer. Two aerosols were studied: a laboratory-produced 238 PuO 2 aerosol (15.8 Ci/g) and a plutonium mixed-oxide aerosol (PU-MOX, natural UO 2 plus PuO 2 , 0.02 Ci/g) formed during industrial centerless grinding of mixed-oxide reactor fuel pellets. Plutonium-238 dioxide particles produced in the laboratory exhibited a small net positive charge within a few minutes after passing through a 85 Kr discharger due to alpha particle emission removal of valence electrons. PU-MOX aerosols produced during centerless grinding showed a charge distribution essentially in Boltzmann equilibrium. The gross alpha aerosol concentrations (960-1200 nCi/l) within the glove box were sufficient to provide high ion concentrations capable of discharging the charge induced by mechanical and/or nuclear decay processes

  14. Aerosol Scrubbing Performance Test for Self-Priming Scrubbing Nozzle Submerged in Water Pool

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Doo Yong; Jung, Woo Young; Lee, Hyun Chul; Lee, Jong Chan; Kim, Gyu Tae; Song, Yong Jae [FNC Technology Co., Yongin (Korea, Republic of)

    2016-10-15

    A scrubbing nozzle is one of the key components for a wet scrubber process based Containment Filtered Venting System (CFVS). As a part of a development of Korean CFVS, a self-priming scrubbing nozzle shown in Fig. 1 has been developed based on the well-known venturi scrubber concept. The thermal-hydraulic performances such as the pressure drop across the nozzle, water suction behavior and droplet generation inside throat have been tested in the non-submerged condition as well as submerged condition. The self-priming scrubbing nozzle used for the wet scrubber based CFVS has been developed, which is submerged in the water pool. When there is gas flow at the inlet of the nozzle, the pool water is passively sucked from the water suction slit. The fine droplets generated inside the throat capture the aerosol particles and is discharged into the water pool. In the water pool, the pool scrubbing happens. The aerosol scrubbing performance tests for the developed self-priming scrubbing nozzle has been conducted under the operational conditions such as different aerosol sizes, different carrier gas steam fractions, different, different pool water level and nozzle inlet pressure. The major findings are as follows. (1) Aerosol scrubbing efficiency increases with the increase of the aerosol size. (2) Aerosol scrubbing efficiency increases with the increase of the carrier gas steam fraction. (3) Aerosol scrubbing.

  15. Aerosol Scrubbing Performance Test for Self-Priming Scrubbing Nozzle Submerged in Water Pool

    International Nuclear Information System (INIS)

    Lee, Doo Yong; Jung, Woo Young; Lee, Hyun Chul; Lee, Jong Chan; Kim, Gyu Tae; Song, Yong Jae

    2016-01-01

    A scrubbing nozzle is one of the key components for a wet scrubber process based Containment Filtered Venting System (CFVS). As a part of a development of Korean CFVS, a self-priming scrubbing nozzle shown in Fig. 1 has been developed based on the well-known venturi scrubber concept. The thermal-hydraulic performances such as the pressure drop across the nozzle, water suction behavior and droplet generation inside throat have been tested in the non-submerged condition as well as submerged condition. The self-priming scrubbing nozzle used for the wet scrubber based CFVS has been developed, which is submerged in the water pool. When there is gas flow at the inlet of the nozzle, the pool water is passively sucked from the water suction slit. The fine droplets generated inside the throat capture the aerosol particles and is discharged into the water pool. In the water pool, the pool scrubbing happens. The aerosol scrubbing performance tests for the developed self-priming scrubbing nozzle has been conducted under the operational conditions such as different aerosol sizes, different carrier gas steam fractions, different, different pool water level and nozzle inlet pressure. The major findings are as follows. (1) Aerosol scrubbing efficiency increases with the increase of the aerosol size. (2) Aerosol scrubbing efficiency increases with the increase of the carrier gas steam fraction. (3) Aerosol scrubbing

  16. Secondary organic aerosol formation and composition from the photo-oxidation of methyl chavicol (estragole)

    Science.gov (United States)

    Pereira, K. L.; Hamilton, J. F.; Rickard, A. R.; Bloss, W. J.; Alam, M. S.; Camredon, M.; Muñoz, A.; Vázquez, M.; Borrás, E.; Ródenas, M.

    2014-06-01

    The increasing demand for palm oil for uses in biofuel and food products is leading to rapid expansion of oil palm agriculture. Methyl chavicol (also known as estragole and 1-allyl-4-methoxybenzene) is an oxygenated biogenic volatile organic compound (VOC) that was recently identified as the main floral emission from an oil palm plantation in Malaysian Borneo. The emissions of methyl chavicol observed may impact regional atmospheric chemistry, but little is known of its ability to form secondary organic aerosol (SOA). The photo-oxidation of methyl chavicol was investigated at the European Photoreactor chamber as a part of the atmospheric chemistry of methyl chavicol (ATMECH) project. Aerosol samples were collected using a particle into liquid sampler (PILS) and analysed offline using an extensive range of instruments including; high-performance liquid chromatography mass spectrometry (HPLC-ITMS), high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (HPLC-QTOFMS) and Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). The SOA yield was determined as 18 and 29% for an initial VOC mixing ratio of 212 and 460 ppbv (parts per billion by volume) respectively; using a VOC:NOx ratio of ~5:1. In total, 59 SOA compounds were observed and the structures of 10 compounds have been identified using high-resolution tandem mass spectrometry. The addition of hydroxyl and/or nitro-functional groups to the aromatic ring appears to be an important mechanistic pathway for aerosol formation. This results in the formation of compounds with both low volatility and high O:C ratios, where functionalisation rather than fragmentation is mainly observed as a result of the stability of the ring. The SOA species observed can be characterised as semi-volatile to low-volatility oxygenated organic aerosol (SVOOA and LVOOA) components and therefore may be important in aerosol formation and growth.

  17. Late-occurring pulmonary pathologies following inhalation of mixed oxide (uranium + plutonium oxide) aerosol in the rat.

    Science.gov (United States)

    Griffiths, N M; Van der Meeren, A; Fritsch, P; Abram, M-C; Bernaudin, J-F; Poncy, J L

    2010-09-01

    Accidental exposure by inhalation to alpha-emitting particles from mixed oxide (MOX: uranium and plutonium oxide) fuels is a potential long-term health risk to workers in nuclear fuel fabrication plants. For MOX fuels, the risk of lung cancer development may be different from that assigned to individual components (plutonium, uranium) given different physico-chemical characteristics. The objective of this study was to investigate late effects in rat lungs following inhalation of MOX aerosols of similar particle size containing 2.5 or 7.1% plutonium. Conscious rats were exposed to MOX aerosols and kept for their entire lifespan. Different initial lung burdens (ILBs) were obtained using different amounts of MOX. Lung total alpha activity was determined by external counting and at autopsy for total lung dose calculation. Fixed lung tissue was used for anatomopathological, autoradiographical, and immunohistochemical analyses. Inhalation of MOX at ILBs ranging from 1-20 kBq resulted in lung pathologies (90% of rats) including fibrosis (70%) and malignant lung tumors (45%). High ILBs (4-20 kBq) resulted in reduced survival time (N = 102; p inhalation result in similar risk for development of lung tumors as compared with industrial plutonium oxide.

  18. In vitro tests for aerosol deposition. III: effect of inhaler insertion angle on aerosol deposition.

    Science.gov (United States)

    Delvadia, Renish R; Longest, P Worth; Hindle, Michael; Byron, Peter R

    2013-06-01

    Inhaler orientation with respect to a patient's mouth may be an important variable determining the efficiency of aerosol lung delivery. The effect of insertion angle on regional deposition was evaluated for a series of inhalers using concurrent in vitro and computational fluid dynamics (CFD) analysis. Geometrically realistic physical mouth-throat (MT) and upper tracheobronchial (TB) models were constructed to connect different inhalers at a series of insertion angles relative to the horizontal plane of the model. These models were used to assess albuterol sulfate deposition from the Novolizer(®) dry powder inhaler (DPI), Proventil(®) HFA pressurized metered dose inhaler (MDI), and Respimat(®) Soft Mist™ Inhaler (SMI) following the actuation of a single dose. Drug deposition from Novolizer DPI was studied for Salbulin(®) and an experimental "drug only" formulation. Albuterol sulfate was recovered and quantified from the device and the MT and TB regions. Significant differences in MT and total lung dose (TLD) of albuterol sulfate deposition were not observed for Salbulin Novolizer DPI and Respimat SMI inserted at different angles. In contrast, drug-only Novolizer DPI and Proventil HFA MDI showed a significant difference in MT and TLD deposition using different insertion angles. For drug-only Novolizer DPI and Proventil HFA MDI, the lowest and the highest MT depositions were observed at +10° and -20°, respectively; for Respimat SMI and Salbulin Novolizer DPI, these angles were -10° and +10°, and +20° and -20°, respectively. CFD simulations were in agreement with the experimental results and illustrated shifts in local particle deposition associated with changes in insertion angle. The effect of inhaler orientation at the inhaler-mouth interface on MT aerosol deposition appeared to be dependent on velocity, aerosol size, and formulation. These findings not only demonstrate the need for patient education on correct inhaler orientation, but provide important

  19. Development and testing of an aerosol-stratus cloud parameterization scheme for middle and high latitudes

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, P.Q.; Meyers, M.P.; Kreidenweis, S.; Cotton, W.R. [Colorado State Univ., Fort Collins, CO (United States)

    1996-04-01

    The aim of this new project is to develop an aerosol/cloud microphysics parameterization of mixed-phase stratus and boundary layer clouds. Our approach is to create, test, and implement a bulk-microphysics/aerosol model using data from Atmospheric Radiation Measurement (ARM) Cloud and Radiation Testbed (CART) sites and large-eddy simulation (LES) explicit bin-resolving aerosol/microphysics models. The primary objectives of this work are twofold. First, we need the prediction of number concentrations of activated aerosol which are transferred to the droplet spectrum, so that the aerosol population directly affects the cloud formation and microphysics. Second, we plan to couple the aerosol model to the gas and aqueous-chemistry module that will drive the aerosol formation and growth. We begin by exploring the feasibility of performing cloud-resolving simulations of Arctic stratus clouds over the North Slope CART site. These simulations using Colorado State University`s regional atmospheric modeling system (RAMS) will be useful in designing the structure of the cloud-resolving model and in interpreting data acquired at the North Slope site.

  20. Glutathione aerosol suppresses lung epithelial surface inflammatory cell-derived oxidants in cystic fibrosis.

    Science.gov (United States)

    Roum, J H; Borok, Z; McElvaney, N G; Grimes, G J; Bokser, A D; Buhl, R; Crystal, R G

    1999-07-01

    Cystic fibrosis (CF) is characterized by accumulation of activated neutrophils and macrophages on the respiratory epithelial surface (RES); these cells release toxic oxidants, which contribute to the marked epithelial derangements seen in CF. These deleterious consequences are magnified, since reduced glutathione (GSH), an antioxidant present in high concentrations in normal respiratory epithelial lining fluid (ELF), is deficient in CF ELF. To evaluate the feasibility of increasing ELF GSH levels and enhancing RES antioxidant protection, GSH aerosol was delivered (600 mg twice daily for 3 days) to seven patients with CF. ELF total, reduced, and oxidized GSH increased (P < 0.05, all compared with before GSH therapy), suggesting adequate RES delivery and utilization of GSH. Phorbol 12-myristate 13-acetate-stimulated superoxide anion (O2-.) release by ELF inflammatory cells decreased after GSH therapy (P < 0.002). This paralleled observations that GSH added in vitro to CF ELF inflammatory cells suppressed O2-. release (P < 0.001). No adverse effects were noted during treatment. Together, these observations demonstrate the feasibility of using GSH aerosol to restore RES oxidant-antioxidant balance in CF and support the rationale for further clinical evaluation.

  1. Reactive oxidation products promote secondary organic aerosol formation from green leaf volatiles

    Directory of Open Access Journals (Sweden)

    J. F. Hamilton

    2009-06-01

    Full Text Available Green leaf volatiles (GLVs are an important group of chemicals released by vegetation which have emission fluxes that can be significantly increased when plants are damaged or stressed. A series of simulation chamber experiments has been conducted at the European Photoreactor in Valencia, Spain, to investigate secondary organic aerosol (SOA formation from the atmospheric oxidation of the major GLVs cis-3-hexenylacetate and cis-3-hexen-1-ol. Liquid chromatography-ion trap mass spectrometry was used to identify chemical species present in the SOA. Cis-3-hexen-1-ol proved to be a more efficient SOA precursor due to the high reactivity of its first generation oxidation product, 3-hydroxypropanal, which can hydrate and undergo further reactions with other aldehydes resulting in SOA dominated by higher molecular weight oligomers. The lower SOA yields produced from cis-3-hexenylacetate are attributed to the acetate functionality, which inhibits oligomer formation in the particle phase. Based on observed SOA yields and best estimates of global emissions, these compounds may be calculated to be a substantial unidentified global source of SOA, contributing 1–5 TgC yr−1, equivalent to around a third of that predicted from isoprene. Molecular characterization of the SOA, combined with organic mechanistic information, has provided evidence that the formation of organic aerosols from GLVs is closely related to the reactivity of their first generation atmospheric oxidation products, and indicates that this may be a simple parameter that could be used in assessing the aerosol formation potential for other unstudied organic compounds in the atmosphere.

  2. Aerosol composition, oxidation properties, and sources in Beijing: results from the 2014 Asia-Pacific Economic Cooperation summit study

    Science.gov (United States)

    Xu, W. Q.; Sun, Y. L.; Chen, C.; Du, W.; Han, T. T.; Wang, Q. Q.; Fu, P. Q.; Wang, Z. F.; Zhao, X. J.; Zhou, L. B.; Ji, D. S.; Wang, P. C.; Worsnop, D. R.

    2015-12-01

    The mitigation of air pollution in megacities remains a great challenge because of the complex sources and formation mechanisms of aerosol particles. The 2014 Asia-Pacific Economic Cooperation (APEC) summit in Beijing serves as a unique experiment to study the impacts of emission controls on aerosol composition, size distributions, and oxidation properties. Herein, a high-resolution time-of-flight aerosol mass spectrometer was deployed in urban Beijing for real-time measurements of size-resolved non-refractory submicron aerosol (NR-PM1) species from 14 October to 12 November 2014, along with a range of collocated measurements. The average (±σ) PM1 was 41.6 (±38.9) μg m-3 during APEC, which was decreased by 53 % compared with that before APEC. The aerosol composition showed substantial changes owing to emission controls during APEC. Secondary inorganic aerosol (SIA: sulfate + nitrate + ammonium) showed significant reductions of 62-69 %, whereas organics presented much smaller decreases (35 %). The results from the positive matrix factorization of organic aerosol (OA) indicated that highly oxidized secondary organic aerosol (SOA) showed decreases similar to those of SIA during APEC. However, primary organic aerosol (POA) from cooking, traffic, and biomass-burning sources were comparable to those before APEC, indicating the presence of strong local source emissions. The oxidation properties showed corresponding changes in response to OA composition. The average oxygen-to-carbon level during APEC was 0.36 (±0.10), which is lower than the 0.43 (±0.13) measured before APEC, demonstrating a decrease in the OA oxidation degree. The changes in size distributions of primary and secondary species varied during APEC. SIA and SOA showed significant reductions in large accumulation modes with peak diameters shifting from ~ 650 to 400 nm during APEC, whereas those of POA remained relatively unchanged. The changes in aerosol composition, size distributions, and oxidation

  3. Indium oxide deposition on glass by aerosol pyrolysis (Pyrosol (R) process)

    International Nuclear Information System (INIS)

    Blandenet, G.; Lagarde, Y.; Spitz, J.

    1975-01-01

    The pyrosol (R) process involves the pyrolysis of an aerosol generated by ultrasonic nebulisation from a solution of organic or inorganic compounds. This technique was used to deposit transparent n-conducting indium oxide films on glass. The electrical and optical properties of these films were studied as a function of the deposition temperature and doping (using tin or fluorine). A deposition temperature of 480 deg C and a Sn/In ratio of about 5% gave the best results. In this case, the transmission in the visible range was 92%, the infrared reflection 84% and the electrical resistivity 1.7x10 -4 ohm.cm [fr

  4. In-cloud oxidation of SO2 as deduced from trace elements in aerosol and precipitation

    International Nuclear Information System (INIS)

    Heaton, R.; Rahn, K.A.

    1985-01-01

    During the past year, the authors have developed and begun to apply a sampling and analytical technique for precipitation which can measure nearly as many elements (30-40) as in the parent aerosol. Rain is collected in a polyethylene bag mounted directly under a simple polyethylene funnel. Typically, up to 500 ml are accumulated; sampling begins only after the rain has started. Snow is scooped into the same kind of bag during or shortly after the event; up to 500 ml are accumulated by repeated sampling and melting in the laboratory. The bags are sealed, frozen overnight, then opened and freeze-dried until all the ice has disappeared. The bag and its contents are then analyzed by instrumental neutron activation at the Rhode Island Nuclear Science Center. Sulfate is determined from a small aliquot of the precipitation removed before it is frozen. For comparison, aerosol samples taken before, during, and after the event are analyzed similarly. The principal goal of this research is to develop procedures for applying the University of Rhode Island's regional elemental tracer system, originally to use the patter of trace elements in precipitation to determine the fraction of the sulfate which has been produced by in-cloud oxidation of SO 2 , as opposed to direct scavenging of sulfate from aerosol

  5. Effects of SO2 oxidation on ambient aerosol growth in water and ethanol vapours

    Directory of Open Access Journals (Sweden)

    T. Petäjä

    2005-01-01

    Full Text Available Hygroscopicity (i.e. water vapour affinity of atmospheric aerosol particles is one of the key factors in defining their impacts on climate. Condensation of sulphuric acid onto less hygroscopic particles is expected to increase their hygrocopicity and hence their cloud condensation nuclei formation potential. In this study, differences in the hygroscopic and ethanol uptake properties of ultrafine aerosol particles in the Arctic air masses with a different exposure to anthropogenic sulfur pollution were examined. The main discovery was that Aitken mode particles having been exposed to polluted air were more hygroscopic and less soluble to ethanol than after transport in clean air. This aging process was attributed to sulphur dioxide oxidation and subsequent condensation during the transport of these particle to our measurement site. The hygroscopicity of nucleation mode aerosol particles, on the other hand, was approximately the same in all the cases, being indicative of a relatively similar chemical composition despite the differences in air mass transport routes. These particles had also been produced closer to the observation site typically 3–8 h prior to sampling. Apparently, these particles did not have an opportunity to accumulate sulphuric acid on their way to the site, but instead their chemical composition (hygroscopicity and ethanol solubility resembled that of particles produced in the local or semi-regional ambient conditions.

  6. Organic nitrate and secondary organic aerosol yield from NO3 oxidation of β-pinene evaluated using a gas-phase kinetics/aerosol partitioning model

    Directory of Open Access Journals (Sweden)

    H.-P. Dorn

    2009-02-01

    Full Text Available The yields of organic nitrates and of secondary organic aerosol (SOA particle formation were measured for the reaction NO3+β-pinene under dry and humid conditions in the atmosphere simulation chamber SAPHIR at Research Center Jülich. These experiments were conducted at low concentrations of NO3 (NO3+N2O5pvap~5×10−6 Torr (6.67×10−4 Pa, which constrains speculation about the oxidation mechanism and chemical identity of the organic nitrate. Once formed the SOA in this system continues to evolve, resulting in measurable aerosol volume decrease with time. The observations of high aerosol yield from NOx-dependent oxidation of monoterpenes provide an example of a significant anthropogenic source of SOA from biogenic hydrocarbon precursors. Estimates of the NO3+β-pinene SOA source strength for California and the globe indicate that NO3 reactions with monoterpenes are likely an important source (0.5–8% of the global total of organic aerosol on regional and global scales.

  7. Secondary organic aerosol formation from ambient air in an oxidation flow reactor in central Amazonia

    Science.gov (United States)

    Palm, Brett B.; de Sá, Suzane S.; Day, Douglas A.; Campuzano-Jost, Pedro; Hu, Weiwei; Seco, Roger; Sjostedt, Steven J.; Park, Jeong-Hoo; Guenther, Alex B.; Kim, Saewung; Brito, Joel; Wurm, Florian; Artaxo, Paulo; Thalman, Ryan; Wang, Jian; Yee, Lindsay D.; Wernis, Rebecca; Isaacman-VanWertz, Gabriel; Goldstein, Allen H.; Liu, Yingjun; Springston, Stephen R.; Souza, Rodrigo; Newburn, Matt K.; Lizabeth Alexander, M.; Martin, Scot T.; Jimenez, Jose L.

    2018-01-01

    Secondary organic aerosol (SOA) formation from ambient air was studied using an oxidation flow reactor (OFR) coupled to an aerosol mass spectrometer (AMS) during both the wet and dry seasons at the Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) field campaign. Measurements were made at two sites downwind of the city of Manaus, Brazil. Ambient air was oxidized in the OFR using variable concentrations of either OH or O3, over ranges from hours to days (O3) or weeks (OH) of equivalent atmospheric aging. The amount of SOA formed in the OFR ranged from 0 to as much as 10 µg m-3, depending on the amount of SOA precursor gases in ambient air. Typically, more SOA was formed during nighttime than daytime, and more from OH than from O3 oxidation. SOA yields of individual organic precursors under OFR conditions were measured by standard addition into ambient air and were confirmed to be consistent with published environmental chamber-derived SOA yields. Positive matrix factorization of organic aerosol (OA) after OH oxidation showed formation of typical oxidized OA factors and a loss of primary OA factors as OH aging increased. After OH oxidation in the OFR, the hygroscopicity of the OA increased with increasing elemental O : C up to O : C ˜ 1.0, and then decreased as O : C increased further. Possible reasons for this decrease are discussed. The measured SOA formation was compared to the amount predicted from the concentrations of measured ambient SOA precursors and their SOA yields. While measured ambient precursors were sufficient to explain the amount of SOA formed from O3, they could only explain 10-50 % of the SOA formed from OH. This is consistent with previous OFR studies, which showed that typically unmeasured semivolatile and intermediate volatility gases (that tend to lack C = C bonds) are present in ambient air and can explain such additional SOA formation. To investigate the sources of the unmeasured SOA-forming gases during this campaign

  8. Secondary organic aerosol formation from ambient air in an oxidation flow reactor in central Amazonia

    Directory of Open Access Journals (Sweden)

    B. B. Palm

    2018-01-01

    Full Text Available Secondary organic aerosol (SOA formation from ambient air was studied using an oxidation flow reactor (OFR coupled to an aerosol mass spectrometer (AMS during both the wet and dry seasons at the Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5 field campaign. Measurements were made at two sites downwind of the city of Manaus, Brazil. Ambient air was oxidized in the OFR using variable concentrations of either OH or O3, over ranges from hours to days (O3 or weeks (OH of equivalent atmospheric aging. The amount of SOA formed in the OFR ranged from 0 to as much as 10 µg m−3, depending on the amount of SOA precursor gases in ambient air. Typically, more SOA was formed during nighttime than daytime, and more from OH than from O3 oxidation. SOA yields of individual organic precursors under OFR conditions were measured by standard addition into ambient air and were confirmed to be consistent with published environmental chamber-derived SOA yields. Positive matrix factorization of organic aerosol (OA after OH oxidation showed formation of typical oxidized OA factors and a loss of primary OA factors as OH aging increased. After OH oxidation in the OFR, the hygroscopicity of the OA increased with increasing elemental O : C up to O : C ∼ 1.0, and then decreased as O : C increased further. Possible reasons for this decrease are discussed. The measured SOA formation was compared to the amount predicted from the concentrations of measured ambient SOA precursors and their SOA yields. While measured ambient precursors were sufficient to explain the amount of SOA formed from O3, they could only explain 10–50 % of the SOA formed from OH. This is consistent with previous OFR studies, which showed that typically unmeasured semivolatile and intermediate volatility gases (that tend to lack C = C bonds are present in ambient air and can explain such additional SOA formation. To investigate the sources of the

  9. Isoprene oxidation by nitrate radical: alkyl nitrate and secondary organic aerosol yields

    Directory of Open Access Journals (Sweden)

    A. W. Rollins

    2009-09-01

    Full Text Available Alkyl nitrates and secondary organic aerosol (SOA produced during the oxidation of isoprene by nitrate radicals has been observed in the SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber chamber. A 16 h dark experiment was conducted with temperatures at 289–301 K, and maximum concentrations of 11 ppb isoprene, 62.4 ppb O3 and 31.1 ppb NOx. We find the yield of nitrates is 70±8% from the isoprene + NO3 reaction, and the yield for secondary dinitrates produced in the reaction of primary isoprene nitrates with NO3 is 40±20%. We find an effective rate constant for reaction of NO3 with the group of first generation oxidation products to be 7×10−14 molecule−1 cm3 s−1. At the low total organic aerosol concentration in the chamber (max=0.52 μg m−3 we observed a mass yield (ΔSOA mass/Δisoprene mass of 2% for the entire 16 h experiment. However a comparison of the timing of the observed SOA production to a box model simulation of first and second generation oxidation products shows that the yield from the first generation products was <0.7% while the further oxidation of the initial products leads to a yield of 14% (defined as ΔSOA/Δisoprene2x where Δisoprene2x is the mass of isoprene which reacted twice with NO3. The SOA yield of 14% is consistent with equilibrium partitioning of highly functionalized C5 products of isoprene oxidation.

  10. E-cigarette aerosols induce lower oxidative stress in vitro when compared to tobacco smoke.

    Science.gov (United States)

    Taylor, Mark; Carr, Tony; Oke, Oluwatobiloba; Jaunky, Tomasz; Breheny, Damien; Lowe, Frazer; Gaça, Marianna

    2016-07-01

    Tobacco smoking is a risk factor for various diseases. The underlying cellular mechanisms are not fully characterized, but include oxidative stress, apoptosis, and necrosis. Electronic-cigarettes (e-cigarettes) have emerged as an alternative to and a possible means to reduce harm from tobacco smoking. E-cigarette vapor contains significantly lower levels of toxicants than cigarette smoke, but standardized methods to assess cellular responses to exposure are not well established. We investigated whether an in vitro model of the airway epithelium (human bronchial epithelial cells) and commercially available assays could differentiate cellular stress responses to aqueous aerosol extracts (AqE) generated from cigarette smoke and e-cigarette aerosols. After exposure to AqE concentrations of 0.063-0.500 puffs/mL, we measured the intracellular glutathione ratio (GSH:GSSG), intracellular generation of oxidant species, and activation of the nuclear factor erythroid-related factor 2 (Nrf2)-controlled antioxidant response elements (ARE) to characterize oxidative stress. Apoptotic and necrotic responses were characterized by increases in caspase 3/7 activity and reductions in viable cell protease activities. Concentration-dependent responses indicative of oxidative stress were obtained for all endpoints following exposure to cigarette smoke AqE: intracellular generation of oxidant species increased by up to 83%, GSH:GSSG reduced by 98.6% and transcriptional activation of ARE increased by up to 335%. Caspase 3/7 activity was increased by up to 37% and the viable cell population declined by up to 76%. No cellular stress responses were detected following exposure to e-cigarette AqE. The methods used were suitably sensitive to be employed for comparative studies of tobacco and nicotine products.

  11. Laboratory studies of the chemical composition and cloud condensation nuclei (CCN activity of secondary organic aerosol (SOA and oxidized primary organic aerosol (OPOA

    Directory of Open Access Journals (Sweden)

    A. T. Lambe

    2011-09-01

    Full Text Available Secondary organic aerosol (SOA and oxidized primary organic aerosol (OPOA were produced in laboratory experiments from the oxidation of fourteen precursors representing atmospherically relevant biogenic and anthropogenic sources. The SOA and OPOA particles were generated via controlled exposure of precursors to OH radicals and/or O3 in a Potential Aerosol Mass (PAM flow reactor over timescales equivalent to 1–20 days of atmospheric aging. Aerosol mass spectra of SOA and OPOA were measured with an Aerodyne aerosol mass spectrometer (AMS. The fraction of AMS signal at m/z = 43 and m/z = 44 (f43, f44, the hydrogen-to-carbon (H/C ratio, and the oxygen-to-carbon (O/C ratio of the SOA and OPOA were obtained, which are commonly used to characterize the level of oxidation of oxygenated organic aerosol (OOA. The results show that PAM-generated SOA and OPOA can reproduce and extend the observed f44f43 composition beyond that of ambient OOA as measured by an AMS. Van Krevelen diagrams showing H/C ratio as a function of O/C ratio suggest an oxidation mechanism involving formation of carboxylic acids concurrent with fragmentation of carbon-carbon bonds. Cloud condensation nuclei (CCN activity of PAM-generated SOA and OPOA was measured as a function of OH exposure and characterized as a function of O/C ratio. CCN activity of the SOA and OPOA, which was characterized in the form of the hygroscopicity parameter κorg, ranged from 8.4×10−4 to 0.28 over measured O/C ratios ranging from 0.05 to 1.42. This range of κorg and O/C ratio is significantly wider than has been previously obtained. To first order, the κorg-to-O/C relationship is well represented by a linear function of the form κorg = (0.18±0.04 ×O/C + 0.03, suggesting that a simple, semi-empirical parameterization of OOA hygroscopicity and

  12. Nitrate radicals and biogenic volatile organic compounds: oxidation, mechanisms, and organic aerosol

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Nga Lee; Brown, Steven S.; Archibald, Alexander T.; Atlas, Elliot; Cohen, Ronald C.; Crowley, John N.; Day, Douglas A.; Donahue, Neil M.; Fry, Juliane L.; Fuchs, Hendrik; Griffin, Robert J.; Guzman, Marcelo I.; Herrmann, Hartmut; Hodzic, Alma; Iinuma, Yoshiteru; Jimenez, José L.; Kiendler-Scharr, Astrid; Lee, Ben H.; Luecken, Deborah J.; Mao, Jingqiu; McLaren, Robert; Mutzel, Anke; Osthoff, Hans D.; Ouyang, Bin; Picquet-Varrault, Benedicte; Platt, Ulrich; Pye, Havala O. T.; Rudich, Yinon; Schwantes, Rebecca H.; Shiraiwa, Manabu; Stutz, Jochen; Thornton, Joel A.; Tilgner, Andreas; Williams, Brent J.; Zaveri, Rahul A.

    2017-01-01

    Oxidation of biogenic volatile organic compounds (BVOC) by the nitrate radical (NO3) represents one of the important interactions between anthropogenic emissions related to combustion and natural emissions from the biosphere. This interaction has been recognized for more than 3 decades, during which time a large body of research has emerged from laboratory, field, and modeling studies. NO3-BVOC reactions influence air quality, climate and visibility through regional and global budgets for reactive nitrogen (particularly organic nitrates), ozone, and organic aerosol. Despite its long history of research and the significance of this topic in atmospheric chemistry, a number of important uncertainties remain. These include an incomplete understanding of the rates, mechanisms, and organic aerosol yields for NO3-BVOC reactions, lack of constraints on the role of heterogeneous oxidative processes associated with the NO3 radical, the difficulty of characterizing the spatial distributions of BVOC and NO3 within the poorly mixed nocturnal atmosphere, and the challenge of constructing appropriate boundary layer schemes and non-photochemical mechanisms for use in state-of-the-art chemical transport and chemistry–climate models.

    This review is the result of a workshop of the same title held at the Georgia Institute of Technology in June 2015. The first half of the review summarizes the current literature on NO3-BVOC chemistry, with a particular focus on recent advances in instrumentation and models, and in organic nitrate and secondary organic aerosol (SOA) formation chemistry. Building on this current understanding, the second half of the review outlines impacts of NO3-BVOC chemistry on air quality and climate, and suggests critical research needs to better constrain this interaction to improve the predictive capabilities of atmospheric models.

  13. Impact of OH Heterogenous Oxidation on the Evolution of Brown Carbon Aerosol Optical Properties

    Science.gov (United States)

    Schnitzler, E.; Abbatt, J.

    2017-12-01

    The effects of varying relative humidity (RH) on the evolution of brown carbon (BrC) optical properties induced by heterogeneous OH oxidation were investigated in a series of photooxidation chamber experiments. A BrC surrogate was generated from aqueous 1,3-dihydroxybenzene (10 mM) and H2O2 (10 mM) exposed to >300 nm radiation, atomized, passed through a series of trace gas denuders, and injected into the chamber, which was conditioned to about 10 or 60% RH. Following aerosol injection, H2O2 was continuously bubbled into the chamber; an hour later, the chamber was irradiated with black-lights (UV-B) to produce OH. Before irradiation, aerosol absorption and scattering at 405 nm, measured using a photoacoustic spectrometer, decreased due only to deposition and dilution, and single scattering albedo (SSA) was relatively steady. In the presence of gas-phase OH, absorption first increased, despite continued particle losses, and SSA decreased. Subsequently, absorption decreased faster than scattering, and SSA increased uniformly. At 60% RH, colour enhancement, likely associated with functionalization, was greatest after only minutes of reaction. In contrast, at 10% RH, peak colour enhancement occurred after about two hours of reaction, indicating that the decrease in RH and the attendant increase in particle viscosity significantly impeded heterogeneous OH oxidation of the BrC surrogate.

  14. Relationship between chemical composition and oxidative potential of secondary organic aerosol from polycyclic aromatic hydrocarbons

    Science.gov (United States)

    Wang, Shunyao; Ye, Jianhuai; Soong, Ronald; Wu, Bing; Yu, Legeng; Simpson, André J.; Chan, Arthur W. H.

    2018-03-01

    Owing to the complex nature and dynamic behaviors of secondary organic aerosol (SOA), its ability to cause oxidative stress (known as oxidative potential, or OP) and adverse health outcomes remains poorly understood. In this work, we probed the linkages between the chemical composition of SOA and its OP, and investigated impacts from various SOA evolution pathways, including atmospheric oligomerization, heterogeneous oxidation, and mixing with metal. SOA formed from photooxidation of the two most common polycyclic aromatic hydrocarbons (naphthalene and phenanthrene) were studied as model systems. OP was evaluated using the dithiothreitol (DTT) assay. The oligomer-rich fraction separated by liquid chromatography dominates DTT activity in both SOA systems (52 ± 10 % for naphthalene SOA (NSOA), and 56 ± 5 % for phenanthrene SOA (PSOA)). Heterogeneous ozonolysis of NSOA was found to enhance its OP, which is consistent with the trend observed in selected individual oxidation products. DTT activities from redox-active organic compounds and metals were found to be not additive. When mixing with highly redox-active metal (Cu), OP of the mixture decreased significantly for 1,2-naphthoquinone (42 ± 7 %), 2,3-dihydroxynaphthalene (35 ± 1 %), NSOA (50 ± 6 %), and PSOA (43 ± 4 %). Evidence from proton nuclear magnetic resonance (1H NMR) spectroscopy illustrates that such OP reduction upon mixing can be ascribed to metal-organic binding interactions. Our results highlight the role of aerosol chemical composition under atmospheric aging processes in determining the OP of SOA, which is needed for more accurate and explicit prediction of the toxicological impacts from particulate matter.

  15. Test equipment used for radiation protection type testing of aerosol filters at the National Board of Nuclear Safety and Radiation Protection (SAAS)

    International Nuclear Information System (INIS)

    Ullmann, W.; Przyborowski, S.

    1977-01-01

    Following a description of the overall design of test equipment developed in the SAAS for radiation protection type testing of aerosol filters, the most important physical and technical details concerning the preparation and measurement of test aerosols as well as the sampling procedure upstream and downstream of the filter to the tested, are comprehensively discussed. Furthermore, experiences gained during several years with different devices for mixing and diluting the aerosols are reported. (author)

  16. 40 CFR 53.59 - Aerosol transport test for Class I equivalent method samplers.

    Science.gov (United States)

    2010-07-01

    ... through which sample air is flowing during performance of this test. (3) A no-flow filter is a sample filter through which no sample air is intended to flow during performance of this test. (4) A channel is... a device or means to allow or cause the aerosol to be routed to one of several channels. (c...

  17. Aerosol composition, oxidative properties, and sources in Beijing: results from the 2014 Asia-Pacific Economic Cooperation Summit study

    Science.gov (United States)

    Xu, W. Q.; Sun, Y. L.; Chen, C.; Du, W.; Han, T. T.; Wang, Q. Q.; Fu, P. Q.; Wang, Z. F.; Zhao, X. J.; Zhou, L. B.; Ji, D. S.; Wang, P. C.; Worsnop, D. R.

    2015-08-01

    The mitigation of air pollution in megacities remains a great challenge because of the complex sources and formation mechanisms of aerosol particles. The 2014 Asia- Pacific Economic Cooperation (APEC) summit in Beijing serves as a unique experiment to study the impacts of emission controls on aerosol composition, size distributions, and oxidative properties. Herein, a high-resolution time-of-flight aerosol mass spectrometer was deployed in urban Beijing for real-time measurements of size-resolved non-refractory submicron aerosol (NR-PM1) species from 14 October to 12 November 2014, along with a range of collocated measurements. The average (±σ) PM1 was 41.6 (±38.9) μg m-3 during APEC, which was decreased by 53 % compared with that before APEC. The aerosol composition showed substantial changes owing to emission controls during APEC. Secondary inorganic aerosols (SIA = sulfate + nitrate + ammonium) showed significant reductions of 62-69 %, whereas organics presented much smaller decreases (35 %). The results from the positive matrix factorization of organic aerosols (OA) indicated that highly oxidized secondary OA (SOA) showed decreases similar to those of SIA during APEC. However, primary OA (POA) from cooking, traffic, and biomass burning sources were comparable to those before APEC, indicating the presence of strong local source emissions. The oxidation properties showed corresponding changes in response to OA composition. The average oxygen-to-carbon level during APEC was 0.36 (±0.10), which is lower than the 0.43 (±0.13) measured before APEC, demonstrating a decrease in the OA oxidation degree. The changes in size distributions of primary and secondary species varied during APEC. SIA and SOA showed significant reductions in large accumulation modes with peak diameters shifting from ~ 650 to 400 nm during APEC, whereas those of POA remained relatively unchanged. The changes in aerosol composition, size distributions, and oxidation degrees during the aging

  18. Comparison of physical chemical properties of powders and respirable aerosols of industrial mixed uranium and plutonium oxide fuels

    International Nuclear Information System (INIS)

    Eidson, A.F.

    1982-01-01

    Studies were performed to characterize physical and chemical properties which may be important in determining the metabolism of accidentally released, inhaled aerosols of industrial mixed uranium and plutonium oxide fuels and to compare the properties of bulk powders and the respirable fraction they include. X-ray diffraction measurements showed that analysis of mixed-oxide powders from four process steps served to characterize their respirable fractions. IR spectroscopy was useful as a method to detect organic binders that were not observed by X-ray diffraction methods. Both X-ray diffraction and IR spectroscopy methods can be used in combination to identify the sources of a complex aerosol that might be released from more than one fabrication step. Isotopic distributions in powders and aerosols showed that information important for radiation dose to tissue calculations or Pu lung burden estimates can be obtained by analysis of powders. (U.K.)

  19. A high-flow humidograph for testing the water uptake by ambient aerosol

    Energy Technology Data Exchange (ETDEWEB)

    Ten Brink, H.M.; Khlystov, A.; Kos, G.P.A. [ECN Fuels Conversion and Environment, Petten (Netherlands); Tuch, T. [Institut of Medical Data Management, Biometrics and Epidemiology, Ludwig-Maximilian University, Muenich (Germany); Roth, C.; Kreyling, W. [Institute for Inhalation Biology, GSF National Research Center for Environment and Health, Neuherberg/Muenich (Germany)

    1999-10-01

    A scanning humidograph, with an air flow rate of 0.5 m{sup 3} s{sup -1} was built to investigate the uptake of water and its effect on sizing, collection and light-scattering of ambient aerosol. The performance of the system was assessed with laboratory particles of ammonium nitrate, ammonium sulfate and sodium chloride which are the major hygroscopic components of ambient aerosol. The increase in size at the deliquescence points, which ideally is a stepwise function of relative humidity, occurs over a range of 3% RH units. This is shown to be an optimum value in a system of such large dimensions. Because of the strong temperature increase of the vapor pressure of ammonium nitrate, its evaporative loss was investigated as a function of heating/drying temperature. The loss of pure test aerosol, with a mass distribution similar to that in the ambient atmosphere, was found to be acceptable for drying temperatures of up to 40C. The sizing of deliquesced aerosol by LAS-X monitors was tested and found to be a complex function of RH. In Berner low pressure impactors growth of hygroscopic aerosol was not observed, not even at an RH approaching saturation. 21 refs.

  20. Compositional evolution of particle-phase reaction products and water in the heterogeneous OH oxidation of model aqueous organic aerosols

    Directory of Open Access Journals (Sweden)

    M. M. Chim

    2017-12-01

    Full Text Available Organic compounds present at or near the surface of aqueous droplets can be efficiently oxidized by gas-phase OH radicals, which alter the molecular distribution of the reaction products within the droplet. A change in aerosol composition affects the hygroscopicity and leads to a concomitant response in the equilibrium amount of particle-phase water. The variation in the aerosol water content affects the aerosol size and physicochemical properties, which in turn governs the oxidation kinetics and chemistry. To attain better knowledge of the compositional evolution of aqueous organic droplets during oxidation, this work investigates the heterogeneous OH-radical-initiated oxidation of aqueous methylsuccinic acid (C5H8O4 droplets, a model compound for small branched dicarboxylic acids found in atmospheric aerosols, at a high relative humidity of 85 % through experimental and modeling approaches. Aerosol mass spectra measured by a soft atmospheric pressure ionization source (Direct Analysis in Real Time, DART coupled with a high-resolution mass spectrometer reveal two major products: a five carbon atom (C5 hydroxyl functionalization product (C5H8O5 and a C4 fragmentation product (C4H6O3. These two products likely originate from the formation and subsequent reactions (intermolecular hydrogen abstraction and carbon–carbon bond scission of tertiary alkoxy radicals resulting from the OH abstraction occurring at the methyl-substituted carbon site. Based on the identification of the reaction products, a kinetic model of oxidation (a two-product model coupled with the Aerosol Inorganic–Organic Mixtures Functional groups Activity Coefficients (AIOMFAC model is built to simulate the size and compositional changes of aqueous methylsuccinic acid droplets during oxidation. Model results show that at the maximum OH exposure, the droplets become slightly more hygroscopic after oxidation, as the mass fraction of water is predicted to increase from

  1. Heterogeneous oxidation of saturated organic aerosols by hydroxyl radicals: uptake kinetics, condensed-phase products, and particle size change

    Directory of Open Access Journals (Sweden)

    I. J. George

    2007-08-01

    Full Text Available The kinetics and reaction mechanism for the heterogeneous oxidation of saturated organic aerosols by gas-phase OH radicals were investigated under NOx-free conditions. The reaction of 150 nm diameter Bis(2-ethylhexyl sebacate (BES particles with OH was studied as a proxy for chemical aging of atmospheric aerosols containing saturated organic matter. An aerosol reactor flow tube combined with an Aerodyne time-of-flight aerosol mass spectrometer (ToF-AMS and scanning mobility particle sizer (SMPS was used to study this system. Hydroxyl radicals were produced by 254 nm photolysis of O3 in the presence of water vapour. The kinetics of the heterogeneous oxidation of the BES particles was studied by monitoring the loss of a mass fragment of BES with the ToF-AMS as a function of OH exposure. We measured an initial OH uptake coefficient of γ0=1.3 (±0.4, confirming that this reaction is highly efficient. The density of BES particles increased by up to 20% of the original BES particle density at the highest OH exposure studied, consistent with the particle becoming more oxidized. Electrospray ionization mass spectrometry analysis showed that the major particle-phase reaction products are multifunctional carbonyls and alcohols with higher molecular weights than the starting material. Volatilization of oxidation products accounted for a maximum of 17% decrease of the particle volume at the highest OH exposure studied. Tropospheric organic aerosols will become more oxidized from heterogeneous photochemical oxidation, which may affect not only their physical and chemical properties, but also their hygroscopicity and cloud nucleation activity.

  2. Effect of relative humidity on the composition of secondary organic aerosol from the oxidation of toluene

    Directory of Open Access Journals (Sweden)

    M. L. Hinks

    2018-02-01

    Full Text Available The effect of relative humidity (RH on the chemical composition of secondary organic aerosol (SOA formed from low-NOx toluene oxidation in the absence of seed particles was investigated. SOA samples were prepared in an aerosol smog chamber at < 2 % RH and 75 % RH, collected on Teflon filters, and analyzed with nanospray desorption electrospray ionization high-resolution mass spectrometry (nano-DESI–HRMS. Measurements revealed a significant reduction in the fraction of oligomers present in the SOA generated at 75 % RH compared to SOA generated under dry conditions. In a separate set of experiments, the particle mass concentrations were measured with a scanning mobility particle sizer (SMPS at RHs ranging from < 2 to 90 %. It was found that the particle mass loading decreased by nearly an order of magnitude when RH increased from < 2 to 75–90 % for low-NOx toluene SOA. The volatility distributions of the SOA compounds, estimated from the distribution of molecular formulas using the molecular corridor approach, confirmed that low-NOx toluene SOA became more volatile on average under high-RH conditions. In contrast, the effect of RH on SOA mass loading was found to be much smaller for high-NOx toluene SOA. The observed increase in the oligomer fraction and particle mass loading under dry conditions were attributed to the enhancement of condensation reactions, which produce water and oligomers from smaller compounds in low-NOx toluene SOA. The reduction in the fraction of oligomeric compounds under humid conditions is predicted to partly counteract the previously observed enhancement in the toluene SOA yield driven by the aerosol liquid water chemistry in deliquesced inorganic seed particles.

  3. In situ secondary organic aerosol formation from ambient pine forest air using an oxidation flow reactor

    Science.gov (United States)

    Palm, Brett B.; Campuzano-Jost, Pedro; Ortega, Amber M.; Day, Douglas A.; Kaser, Lisa; Jud, Werner; Karl, Thomas; Hansel, Armin; Hunter, James F.; Cross, Eben S.; Kroll, Jesse H.; Peng, Zhe; Brune, William H.; Jimenez, Jose L.

    2016-03-01

    An oxidation flow reactor (OFR) is a vessel inside which the concentration of a chosen oxidant can be increased for the purpose of studying SOA formation and aging by that oxidant. During the BEACHON-RoMBAS (Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics & Nitrogen-Rocky Mountain Biogenic Aerosol Study) field campaign, ambient pine forest air was oxidized by OH radicals in an OFR to measure the amount of SOA that could be formed from the real mix of ambient SOA precursor gases, and how that amount changed with time as precursors changed. High OH concentrations and short residence times allowed for semicontinuous cycling through a large range of OH exposures ranging from hours to weeks of equivalent (eq.) atmospheric aging. A simple model is derived and used to account for the relative timescales of condensation of low-volatility organic compounds (LVOCs) onto particles; condensational loss to the walls; and further reaction to produce volatile, non-condensing fragmentation products. More SOA production was observed in the OFR at nighttime (average 3 µg m-3 when LVOC fate corrected) compared to daytime (average 0.9 µg m-3 when LVOC fate corrected), with maximum formation observed at 0.4-1.5 eq. days of photochemical aging. SOA formation followed a similar diurnal pattern to monoterpenes, sesquiterpenes, and toluene+p-cymene concentrations, including a substantial increase just after sunrise at 07:00 local time. Higher photochemical aging (> 10 eq. days) led to a decrease in new SOA formation and a loss of preexisting OA due to heterogeneous oxidation followed by fragmentation and volatilization. When comparing two different commonly used methods of OH production in OFRs (OFR185 and OFR254-70), similar amounts of SOA formation were observed. We recommend the OFR185 mode for future forest studies. Concurrent gas-phase measurements of air after OH oxidation illustrate the decay of primary VOCs, production of small oxidized organic

  4. In situ secondary organic aerosol formation from ambient pine forest air using an oxidation flow reactor

    Directory of Open Access Journals (Sweden)

    B. B. Palm

    2016-03-01

    Full Text Available An oxidation flow reactor (OFR is a vessel inside which the concentration of a chosen oxidant can be increased for the purpose of studying SOA formation and aging by that oxidant. During the BEACHON-RoMBAS (Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics & Nitrogen–Rocky Mountain Biogenic Aerosol Study field campaign, ambient pine forest air was oxidized by OH radicals in an OFR to measure the amount of SOA that could be formed from the real mix of ambient SOA precursor gases, and how that amount changed with time as precursors changed. High OH concentrations and short residence times allowed for semicontinuous cycling through a large range of OH exposures ranging from hours to weeks of equivalent (eq. atmospheric aging. A simple model is derived and used to account for the relative timescales of condensation of low-volatility organic compounds (LVOCs onto particles; condensational loss to the walls; and further reaction to produce volatile, non-condensing fragmentation products. More SOA production was observed in the OFR at nighttime (average 3 µg m−3 when LVOC fate corrected compared to daytime (average 0.9 µg m−3 when LVOC fate corrected, with maximum formation observed at 0.4–1.5 eq. days of photochemical aging. SOA formation followed a similar diurnal pattern to monoterpenes, sesquiterpenes, and toluene+p-cymene concentrations, including a substantial increase just after sunrise at 07:00 local time. Higher photochemical aging (> 10 eq. days led to a decrease in new SOA formation and a loss of preexisting OA due to heterogeneous oxidation followed by fragmentation and volatilization. When comparing two different commonly used methods of OH production in OFRs (OFR185 and OFR254-70, similar amounts of SOA formation were observed. We recommend the OFR185 mode for future forest studies. Concurrent gas-phase measurements of air after OH oxidation illustrate the decay of primary VOCs, production

  5. Selective Oxidation Using Flame Aerosol Synthesized Iron and Vanadium-Doped Nano-TiO2

    Directory of Open Access Journals (Sweden)

    Zhong-Min Wang

    2011-01-01

    Full Text Available Selective photocatalytic oxidation of 1-phenyl ethanol to acetophenone using titanium dioxide (TiO2 raw and doped with Fe or V, prepared by flame aerosol deposition method, was investigated. The effects of metal doping on crystal phase and morphology of the synthesized nanostructured TiO2 were analyzed using XRD, TEM, Raman spectroscopy, and BET nitrogen adsorbed surface area measurement. The increase in the concentration of V and Fe reduced the crystalline structure and the anatase-to-rutile ratios of the synthesized TiO2. Synthesized TiO2 became fine amorphous powder as the Fe and V concentrations were increased to 3 and 5%, respectively. Doping V and Fe to TiO2 synthesized by the flame aerosol increased photocatalytic activity by 6 folds and 2.5 folds, respectively, compared to that of pure TiO2. It was found that an optimal doping concentration for Fe and V were 0.5% and 3%, respectively. The type and concentration of the metal dopants and the method used to add the dopant to the TiO2 are critical parameters for enhancing the activity of the resulting photocatalyst. The effects of solvents on the photocatalytic reaction were also investigated by using both water and acetonitrile as the reaction medium.

  6. Intercontinental transport of aerosols and photochemical oxidants from Asia and its consequences

    International Nuclear Information System (INIS)

    Wuebbles, Donald J.; Lei, Hang; Lin, Jintai

    2007-01-01

    The intercontinental transport of aerosols and photochemical oxidants from Asia is a crucial issue for air quality concerns in countries downwind of the significant emissions and concentrations of pollutants occurring in this important region of the world. Since the lifetimes of some important pollutants are long enough to be transported over long distance in the troposphere, regional control strategies for air pollution in downwind countries might be ineffective without considering the effects of long-range transport of pollutants from Asia. Field campaigns provide strong evidence for the intercontinental transport of Asian pollutants. They, together with ground-based observations and model simulations, show that the air quality over parts of North America is being affected by the pollutants transported from Asia. This paper examines the current understanding of the intercontinental transport of gases and aerosols from Asia and resulting effects on air quality, and on the regional and global climate system. - Air quality over parts of North America is being affected by pollutants transported from Asia

  7. Positive patch test reactions to oxidized limonene

    DEFF Research Database (Denmark)

    Bråred Christensson, Johanna; Andersen, Klaus E; Bruze, Magnus

    2014-01-01

    to oxidized R-limonene. OBJECTIVE: To study the exposure to limonene among consecutive dermatitis patients reacting to oxidized R-limonene in an international setting, and to assess the relevance of the exposure for the patients' dermatitis. METHODS: Oxidized R-limonene 3.0% (containing limonene...... hydroperoxides at 0.33%) in petrolatum was tested in 2900 consecutive dermatitis patients in Australia, Denmark, the United Kingdom, Singapore, Spain, and Sweden. A questionnaire assessing exposure to limonene-containing products was completed. RESULTS: Overall, exposure to products containing limonene was found...

  8. Analyses of CsI aerosol deposition tests in WIND project with ART and VICTORIA codes

    International Nuclear Information System (INIS)

    Yuchi, Y.; Shibazaki, H.; Kudo, T.

    2000-01-01

    Deposition behavior of cesium iodide (CsI) was analyzed with ART and VICTORIA-92 codes for a test of the aerosol re-vaporization test series performed in WIND project at JAERI. In the test analyzed, CsI aerosol was injected into piping of test section where metaboric acid (HBO 2 ) was placed in advance on the floor area. It was confirmed in the present analysis that similar results on the CsI deposition were obtained between ART and VICTORIA when influences of chemical interactions were negligibly small. The analysis with VICTORIA agreed satisfactorily with the test results in analytical cases that cesium metaborate (CsBO 2 ) was injected into the test section instead of CsI to simulate the pre-existence of HBO 2 effect. (author)

  9. DTPA therapy of lung contaminations: testing a self contained aerosol generator

    International Nuclear Information System (INIS)

    Ducousso, R.; Pasquier, C.

    1975-01-01

    It has been shown how much the effectiveness of DTPA therapy of respiratory contamination decreased when the delay of administration of the product increased. Moreover, the effectiveness of local administration of the chelating agent as aerosol has been widely recognized. Owing to both the therapeutic urgency and the local administration, an individual pocket apparatus allowing emergency DTPA inhalation, on the spot of the accident was tried. A turbo-inhalator sold for the administration of an anti-asthmatic powder was tested, using DTPA powder inhaled by a volunteer previously contaminated by a 140 LaCl 3 aerosol [fr

  10. Interpersonal Transport of Expiratory Aerosols among Three Manikins in a Full-Scale Test Room

    DEFF Research Database (Denmark)

    Liu, Li; Nielsen, Peter Vilhelm; Jensen, Rasmus Lund

    2014-01-01

    This study focuses on occupants’ exposure of aerosols exhaled by one susceptible in a full-scale test room. Three breathing thermal manikins are standing in the middle of room and both the process in the microenvironment and in the macroenvironment are considered. A diffusive ceiling has been...

  11. Development and calibration of an on-line aerosol monitor for PHEBUS test FPT1

    International Nuclear Information System (INIS)

    O'Brien, J.E.; Carmack, W.J.; Sprenger, M.H.; Thurston, G.C.; Hunt, J.L.

    1994-10-01

    An on-line aerosol monitor (OLAM2) has been developed and tested for PHEBUS test FPT1. OLAM2 utilizes new detachable fiber optic cables and sapphire light pipes for light transmission between the OLAM and the electronics. This light transmission system was tested and found to provide better signal-to-noise performance than was achieved with the continuous fibers used for test FPT0. An additional advantage of the detachable fiber/light pipe system is ease of installation. Aerosol testing (OLAM calibration) was performed in order to verify adequate signal-to-noise performance of the new fiber optic system over the specified operating conditions and to check the quantitative light attenuation measurements against theoretical predictions. Results of the testing indicated that light extinction measurements obtained during Phebus tests could be used to estimate aerosol volume concentrations, if diamond window fouling can be avoided. OLAM2 was also subjected to a proof pressure test and a long-term thermal stability test. These tests verified the mechanical and thermal integrity of the OLAM within design specifications. Long-term output signal stability was also verified with the system maintained at design temperature and half-design pressure

  12. International standard problem ISP37: VANAM M3 - A Multi compartment aerosol depletion test with hygroscopic aerosol material: comparison report

    International Nuclear Information System (INIS)

    Firnhaber, M.; Kanzleiter, T.F.; Schwarz, S.; Weber, G.

    1996-12-01

    This paper presents the results and assessment of the 'open' ISP37, which deals with the containment thermal-hydraulics and aerosol behavior during an unmitigated severe LWR accident with core melt-down and steam and aerosol release into the containment. Representatives of 22 organizations participated to the ISP37 using the codes CONTAIN, FIPLOC, MELCOR, RALOC, FUMO, MACRES, REMOVAL etc. The containment and aerosol behavior experiment VANAM M3 was selected as experimental comparison basis. The main phenomena investigated are the thermal behavior of a multi-compartment containment, e.g. pressure, temperature and the distribution and depletion of a soluble aerosol. The ISP37 has demonstrated that the codes used could calculate the thermal-hydraulic containment behavior in general with sufficient accuracy. But with respect to the needs of aerosol behavior analysis the accuracies, both analytical and experimental as well, for specific thermal-hydraulic variables should be improved. Although large progress has been made in the simulation of aerosol behavior in multi-compartment geometries the calculated local aerosol concentrations scatter widely. However, the aerosol source term to the environment is overestimated in general. The largest uncertainty concerning the aerosol results is caused by a limited number of thermal hydraulic variables like relative humidity, volume condensation rate and atmospheric flow rate. In some codes also a solubility model is missing

  13. An SOA model for toluene oxidation in the presence of inorganic aerosols.

    Science.gov (United States)

    Cao, Gang; Jang, Myoseon

    2010-01-15

    A predictive model for secondary organic aerosol (SOA) formation including both partitioning and heterogeneous reactions is explored for the SOA produced from the oxidation of toluene in the presence of inorganic seed aerosols. The predictive SOA model comprises the explicit gas-phase chemistry of toluene, gas-particle partitioning, and heterogeneous chemistry. The resulting products from the explicit gas phase chemistry are lumped into several classes of chemical species based on their vapor pressure and reactivity for heterogeneous reactions. Both the gas-particle partitioning coefficient and the heterogeneous reaction rate constant of each lumped gas-phase product are theoretically determined using group contribution and molecular structure-reactivity. In the SOA model, the predictive SOA mass is decoupled into partitioning (OM(P)) and heterogeneous aerosol production (OM(H)). OM(P) is estimated from the SOA partitioning model developed by Schell et al. (J. Geophys. Res. 2001, 106, 28275-28293 ) that has been used in a regional air quality model (CMAQ 4.7). OM(H) is predicted from the heterogeneous SOA model developed by Jang et al. (Environ. Sci. Technol. 2006, 40, 3013-3022 ). The SOA model is evaluated using a number of the experimental SOA data that are generated in a 2 m(3) indoor Teflon film chamber under various experimental conditions (e.g., humidity, inorganic seed compositions, NO(x) concentrations). The SOA model reasonably predicts not only the gas-phase chemistry, such as the ozone formation, the conversion of NO to NO(2), and the toluene decay, but also the SOA production. The model predicted that the OM(H) fraction of the total toluene SOA mass increases as NO(x) concentrations decrease: 0.73-0.83 at low NO(x) levels and 0.17-0.47 at middle and high NO(x) levels for SOA experiments with high initial toluene concentrations. Our study also finds a significant increase in the OM(H) mass fraction in the SOA generated with low initial toluene

  14. The hygroscopicity parameter (κ) of ambient organic aerosol at a field site subject to biogenic and anthropogenic influences: relationship to degree of aerosol oxidation

    Science.gov (United States)

    Chang, R. Y.-W.; Slowik, J. G.; Shantz, N. C.; Vlasenko, A.; Liggio, J.; Sjostedt, S. J.; Leaitch, W. R.; Abbatt, J. P. D.

    2010-06-01

    Cloud condensation nuclei (CCN) concentrations were measured at Egbert, a rural site in Ontario, Canada during the spring of 2007. The CCN concentrations were compared to values predicted from the aerosol chemical composition and size distribution using κ-Köhler theory, with the specific goal of this work being to determine the hygroscopic parameter (κ) of the oxygenated organic component of the aerosol, assuming that oxygenation drives the hygroscopicity for the entire organic fraction of the aerosol. The hygroscopicity of the oxygenated fraction of the organic component, as determined by an Aerodyne aerosol mass spectrometer (AMS), was characterised by two methods. First, positive matrix factorization (PMF) was used to separate oxygenated and unoxygenated organic aerosol factors. By assuming that the unoxygenated factor is completely non-hygroscopic and by varying κ of the oxygenated factor so that the predicted and measured CCN concentrations are internally consistent and in good agreement, κ of the oxygenated organic factor was found to be 0.22±0.04 for the suite of measurements made during this five-week campaign. In a second, equivalent approach, we continue to assume that the unoxygenated component of the aerosol, with a mole ratio of atomic oxygen to atomic carbon (O/C) ≈ 0, is completely non-hygroscopic, and we postulate a simple linear relationship between κorg and O/C. Under these assumptions, the κ of the entire organic component for bulk aerosols measured by the AMS can be parameterised as κorg=(0.29±0.05)·(O/C), for the range of O/C observed in this study (0.3 to 0.6). These results are averaged over our five-week study at one location using only the AMS for composition analysis. Empirically, our measurements are consistent with κorg generally increasing with increasing particle oxygenation, but high uncertainties preclude us from testing this hypothesis. Lastly, we examine select periods of different aerosol composition, corresponding

  15. Aerosol - assisted Chemical Vapor Deposition of Metal Oxide Structures: Zinc Oxide Rods

    Czech Academy of Sciences Publication Activity Database

    Vallejos, S.; Pizúrová, Naděžda; Čechal, J.; Grácia, I.; Cané, C.

    2017-01-01

    Roč. 2017, Č. 127 (2017), č. článku e56127. ISSN 1940-087X Institutional support: RVO:68081723 Keywords : Zinc oxide * columnar structures * rods * AACVD * non-catalyzed growth * vapor-solid mechanism Subject RIV: CA - Inorganic Chemistry OBOR OECD: Polymer science Impact factor: 1.232, year: 2016 https://www.jove.com/video/56127

  16. The inhalation of insoluble iron oxide particles in the sub-micron ranges. Part II - Plutonium-237 labelled aerosols

    International Nuclear Information System (INIS)

    Waite, D.A.; Ramsden, D.

    1971-10-01

    The results of a series of inhalation studies using iron oxide particles in the size range 0.1 to 0.3 um (count median diameter) are described. In this series the aerosols were labelled with plutonium 237. In vivo detection, excretion analysis and crude location studies were obtainable and the results compared to the earlier studies using chromium 51 labelled aerosols. Plutonium 237 can be considered as a simulator for plutonium 239 and attempts are made to extrapolate the results to the problem of the estimation of plutonium 239 in the human lung. (author)

  17. Remote aerosol testing of large size HEPA filter banks

    International Nuclear Information System (INIS)

    Franklin, B.; Pasha, M.; Bronger, C.A.

    1987-01-01

    Different methods of testing HEPA filter banks are described. Difficulties in remote testing of large banks of HEPA filters in series with minimum distances between banks, and with no available access upstream and downstream of the filter house, are discussed. Modifications incorporated to make the filter system suitable for remote testing without personnel re-entry into the filter house are described for a 51,000 m/sup 3//hr filter unit at the WIPP site

  18. Mathematical modelling of the kinetics of aerosol oxidation of sulfur dioxide upon electron-beam purification of power-plant flue gases from nitrogen and sulfur oxides

    International Nuclear Information System (INIS)

    Gerasimov, G.Ya.; Gerasimova, T.S.; Fadeev, S.A.

    1996-01-01

    A kinetic model of SO 2 oxidation in flue gases, irradiated with accelerated electron flux is proposed. The model comprises an optimized mechanism of gas phase radiation chemical oxidation of NO and SO 2 , kinetics circuit of SO 2 and NH 3 thermal interaction, kinetic models of volumetric condensation of water and sulfuric acid vapors and liquid-phase oxidation of SO 2 in aerosol drops, produced in the course of volumetric condensation. Calculation results are in a satisfactory agreement with experimental data. (author)

  19. Mass yields of secondary organic aerosols from the oxidation of α-pinene and real plant emissions

    Directory of Open Access Journals (Sweden)

    J. N. Smith

    2011-02-01

    Full Text Available Biogenic volatile organic compounds (VOCs are a significant source of global secondary organic aerosol (SOA; however, quantifying their aerosol forming potential remains a challenge. This study presents smog chamber laboratory work, focusing on SOA formation via oxidation of the emissions of two dominant tree species from boreal forest area, Scots pine (Pinus sylvestris L. and Norway spruce (Picea abies, by hydroxyl radical (OH and ozone (O3. Oxidation of α-pinene was also studied as a reference system. Tetramethylethylene (TME and 2-butanol were added to control OH and O3 levels, thereby allowing SOA formation events to be categorized as resulting from either OH-dominated or O3-initiated chemistry. SOA mass yields from α-pinene are consistent with previous studies while the yields from the real plant emissions are generally lower than that from α-pinene, varying from 1.9% at an aerosol mass loading of 0.69 μg m−3 to 17.7% at 26.0 μg m−3. Mass yields from oxidation of real plant emissions are subject to the interactive effects of the molecular structures of plant emissions and their reaction chemistry with OH and O3, which lead to variations in condensable product volatility. SOA formation can be reproduced with a two-product gas-phase partitioning absorption model in spite of differences in the source of oxidant species and product volatility in the real plant emission experiments. Condensable products from OH-dominated chemistry showed a higher volatility than those from O3-initiated systems during aerosol growth stage. Particulate phase products became less volatile via aging process which continued after input gas-phase oxidants had been completely consumed.

  20. Removal of inhaled industrial mixed oxide aerosols from Beagle dogs by lung lavage and chelation therapy

    International Nuclear Information System (INIS)

    Muggenburg, B.A.; Mewhinney, J.A.; Eidson, A.F.; Guilmette, R.A.

    1978-01-01

    An experiment was conducted in 15 adult Beagle dogs to evaluate lung lavage and chelation therapy for the removal of inhaled particles of mixed actinide oxides. The dogs were divided into three groups of five dogs each. Each group was exposed to an aerosol from a different industrial process. Group 1 was exposed to mixed oxide material which had been calcined at 750 0 C collected from a ball milling process. Group 2 was exposed to mixed oxide material from a centerless grinding operation which had been previously heat treated to 1750 0 C. The third group was exposed to 239 PuO 2 not containing uranium from a V-blending procedure which had been heat treated at 850 0 C. After exposure, three dogs in each group were given ten lung lavages and 18 intravenous injections of calcium trisodium diethylenetriaminepentaacetate (DTPA). All dogs were sacrificed 64 days after inhalation exposure. The tissues were radioanalyzed for plutonium and americium. Fluorimetric analyses for uranium in the tissues are in progress. The urine, feces and lavage fluid are also being analyzed for plutonium, americium and uranium. The distribution of plutonium and americium expressed as percentages of the sacrifice body burden was similar in the tissues of the treated and unteated dogs. The lungs contained most of the radionuclides with a small amount in the liver, skeleton and tracheobronchial lymph nodes. The percentage of the sacrifice body burden of americium and plutonium that was present in the lung was less in the treated dogs and was higher in the TBLN's and skeleton than in the untreated dogs. The ratio of Pu/Am was higher in the lungs than in the original material obtained from the industrial sites suggesting a shorter retention time for americium than plutonium to 64 days in the dog

  1. Aqueous Oxidation of Green Leaf Volatiles as a Source of Secondary Organic Aerosol

    Science.gov (United States)

    Richards-Henderson, N. K.; Hansel, A.; Pham, A. T.; Vempati, H. S.; Valsaraj, K. T.; Anastasio, C.

    2013-12-01

    Vegetation emits volatile oxygenated hydrocarbons - the green leaf volatiles (GLVs) - which are formed from the biochemical conversion of linoleic and linolenic acids within plant cells. Stress or damage to vegetation can significantly elevate emission fluxes of these compounds, some of which are fairly water soluble. Aqueous-phase reactions of the GLVs with photochemically generated oxidants - such as hydroxyl radical (OH), singlet oxygen (1O2) and excited triplet states of organic compounds (3C*) _ might then form low-volatility products that can act as secondary organic aerosol (SOA). In order to determine if GLVs can be a significant source of secondary organic carbon in fogwater, studies of GLVs in laboratory solutions are needed to elucidate the oxidation kinetics and the corresponding SOA mass yields. In this study we are determining the second-order rate constants, and SOA mass yields, for five GLVs (cis-3-hexen-1-ol, cis-3-hexenylacetate, methyl salicylate, methyl jasmonate, and 2-methyl-3-butene-2-ol) reacting with OH,1O2 and 3C*. Experiments are performed at relevant fog water pHs, temperatures, and oxidant concentrations. Rate constants are determined using a relative rate approach in which the decay of GLVs and reference compounds are monitored as function of time by HPLC. The capacity of GLVs to form aqueous SOA was determined by following the formation of their decomposition products with HPLC-UV/DAD and HPLC-ESI/MS. SOA mass yields are measured gravimetrically from laboratory solutions containing atmospherically relevant concentrations of photooxidants and GLVs, and irradiated with simulated sunlight. We will use our results to assess the potential contribution of aqueous GLV reactions as a source of SOA in cloudy or foggy atmospheres.

  2. Steam Oxidation Testing in the Severe Accident Test Station

    Energy Technology Data Exchange (ETDEWEB)

    Pint, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-08-01

    After the March 2011 accident at Fukushima Daiichi, Oak Ridge National Laboratory (ORNL) began conducting high temperature steam oxidation testing of candidate materials for accident tolerant fuel (ATF) cladding in August 2011 [1-11]. The ATF concept is to enhance safety margins in light water reactors (LWR) during severe accident scenarios by identifying materials with 100× slower steam oxidation rates compared to current Zr-based alloys. In 2012, the ORNL laboratory equipment was expanded and made available to the entire ATF community as the Severe Accident Test Station (SATS) [4,12]. Compared to the current UO2/Zr-based alloy fuel system, an ATF alternative would significantly reduce the rate of heat and hydrogen generation in the core during a coolant-limited severe accident [13-14]. The steam oxidation behavior of candidate materials is a key metric in the evaluation of ATF concepts and also an important input into models [15-17]. However, initial modeling work of FeCrAl cladding has used incomplete information on the physical properties of FeCrAl. Also, the steam oxidation data being collected at 1200°-1700°C is unique as no prior work has considered steam oxidation of alloys at such high temperatures. Also, because many accident scenarios include steadily increasing temperatures, the required data are not traditional isothermal exposures but exposures with varying “ramp” rates. In some cases, the steam oxidation behavior has been surprising and difficult to interpret. Thus, more fundamental information continues to be collected. In addition, more work continues to focus on commercially-manufactured tube material. This report summarizes recent work to characterize the behavior of candidate alloys exposed to high temperature steam, evaluate steam oxidation behavior in various ramp scenarios and continue to collect integral data on FeCrAl compared to conventional Zr-based cladding.

  3. 21 CFR 862.3080 - Breath nitric oxide test system.

    Science.gov (United States)

    2010-04-01

    ... Systems § 862.3080 Breath nitric oxide test system. (a) Identification. A breath nitric oxide test system... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breath nitric oxide test system. 862.3080 Section... fractional nitric oxide concentration in expired breath aids in evaluating an asthma patient's response to...

  4. Environmental health hazards of e-cigarettes and their components: Oxidants and copper in e-cigarette aerosols.

    Science.gov (United States)

    Lerner, Chad A; Sundar, Isaac K; Watson, Richard M; Elder, Alison; Jones, Ryan; Done, Douglas; Kurtzman, Rachel; Ossip, Deborah J; Robinson, Risa; McIntosh, Scott; Rahman, Irfan

    2015-03-01

    To narrow the gap in our understanding of potential oxidative properties associated with Electronic Nicotine Delivery Systems (ENDS) i.e. e-cigarettes, we employed semi-quantitative methods to detect oxidant reactivity in disposable components of ENDS/e-cigarettes (batteries and cartomizers) using a fluorescein indicator. These components exhibit oxidants/reactive oxygen species reactivity similar to used conventional cigarette filters. Oxidants/reactive oxygen species reactivity in e-cigarette aerosols was also similar to oxidant reactivity in cigarette smoke. A cascade particle impactor allowed sieving of a range of particle size distributions between 0.450 and 2.02 μm in aerosols from an e-cigarette. Copper, being among these particles, is 6.1 times higher per puff than reported previously for conventional cigarette smoke. The detection of a potentially cytotoxic metal as well as oxidants from e-cigarette and its components raises concern regarding the safety of e-cigarettes use and the disposal of e-cigarette waste products into the environment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Environmental Health Hazards of e-Cigarettes and their Components: Oxidants and Copper in e-cigarette aerosols

    Science.gov (United States)

    Lerner, Chad A.; Sundar, Isaac K.; Watson, Richard M.; Elder, Alison; Jones, Ryan; Done, Douglas; Kurtzman, Rachel; Ossip, Deborah J.; Robinson, Risa; McIntosh, Scott; Rahman, Irfan

    2014-01-01

    To narrow the gap in our understanding of potential oxidative properties associated with Electronic Nicotine Delivery systems (ENDS) i.e. e-cigarettes, we employed semi-quantitative methods to detect oxidant reactivity in disposable components of ENDS/e-cigarettes (batteries and cartomizers) using a fluorescein indicator. These components exhibit oxidants/reactive oxygen species reactivity similar to used conventional cigarette filters. Oxidants/reactive oxygen species reactivity in e-cigarette aerosols was also similar to oxidant reactivity in cigarette smoke. A cascade particle impactor allowed sieving of a range of particle size distributions between 0.450 and 2.02 μm in aerosols from an e-cigarette. Copper, being among these particles, is 6.1 times higher per puff than reported previously for conventional cigarette smoke. The detection of a potentially cytotoxic metal as well as oxidants from e-cigarette and its components raises concern regarding the safety of e-cigarettes use and the disposal of e-cigarette waste products into the environment. PMID:25577651

  6. Secondary organic aerosol production from pinanediol, a semi-volatile surrogate for first-generation oxidation products of monoterpenes

    Science.gov (United States)

    Ye, Penglin; Zhao, Yunliang; Chuang, Wayne K.; Robinson, Allen L.; Donahue, Neil M.

    2018-05-01

    We have investigated the production of secondary organic aerosol (SOA) from pinanediol (PD), a precursor chosen as a semi-volatile surrogate for first-generation oxidation products of monoterpenes. Observations at the CLOUD facility at CERN have shown that oxidation of organic compounds such as PD can be an important contributor to new-particle formation. Here we focus on SOA mass yields and chemical composition from PD photo-oxidation in the CMU smog chamber. To determine the SOA mass yields from this semi-volatile precursor, we had to address partitioning of both the PD and its oxidation products to the chamber walls. After correcting for these losses, we found OA loading dependent SOA mass yields from PD oxidation that ranged between 0.1 and 0.9 for SOA concentrations between 0.02 and 20 µg m-3, these mass yields are 2-3 times larger than typical of much more volatile monoterpenes. The average carbon oxidation state measured with an aerosol mass spectrometer was around -0.7. We modeled the chamber data using a dynamical two-dimensional volatility basis set and found that a significant fraction of the SOA comprises low-volatility organic compounds that could drive new-particle formation and growth, which is consistent with the CLOUD observations.

  7. SUBMERGED GRAVEL SCRUBBER DEMONSTRATION AS A PASSIVE AIR CLEANER FOR CONTAINMENT VENTING AND PURGING WITH SODIUM AEROSOLS -- CSTF TESTS AC7 - AC10

    Energy Technology Data Exchange (ETDEWEB)

    HILLIARD, R K.; MCCORMACK, J D.; POSTMA, A K.

    1981-11-01

    Four large-scale air cleaning tests (AC7 - AC10) were performed in the Containment Systems Test Facility (CS'lF) to demonstrate the performance of a Submerged Gravel Scrubber for cleaning the effluent gas from a vented and purged breeder reactor containment vessel. The test article, comprised of a Submerged Gravel Scrubber (SGS) followed by a high efficiency fiber demister, had a design gas flow rate of 0.47 m{sup 3}/s (1000 ft{sup 3}/min) at a pressure drop of 9.0 kPa (36 in. H{sub 2}O). The test aerosol was sodium oxide, sodium hydroxide, or sodium carbonate generated in the 850-m{sup 3} CSTF vessel by continuously spraying sodium into the air-filled vessel while adding steam or carbon dioxide. Approximately 4500 kg (10,000 lb) of sodium was sprayed over a total period of 100 h during the tests. The SGS/Demister system was shown to be highly efficient (removing ~99.98% of the entering sodium aerosol mass), had a high mass loading capacity, and operated in a passive manner, with no electrical requirement. Models for predicting aerosol capture, gas cooling, and pressure drop are developed and compared with experimental results.

  8. Nitrous Oxide Emissions from Biofuel Crops and Atmospheric Aerosols: Associations with Air Quality and Regional Climate

    Science.gov (United States)

    Pillai, Priya Ramachandran

    Emissions of greenhouse gases (GHG) and primary release and secondary formation of aerosols alter the earth's radiative balance and therefore have important climatic implications. Savings in carbon dioxide (CO2) emissions accomplished by replacing fossil fuels with biofuels may increase the nitrous oxide (N2O) emissions. Among various atmospheric trace gases, N2O, irrespective of its low atmospheric concentration, is the fourth most important gas in causing the global greenhouse effect. Major processes, those affect the concentration of atmospheric N2O, are soil microbial activities leading to nitrification and denitrification. Therefore, anthropogenic activities such as industrial emissions, and agricultural practices including application of nitrogenous fertilizers, land use changes, biomass combustion all contribute to the atmospheric N2O concentration. The emission rates of N2O related to biofuel production depend on the nitrogen (N) fertilizer uptake efficiency of biofuel crops. However, crops with less N demand, such as switchgrass may have more favorable climate impacts when compared to crops with high N demands, such as corn. Despite its wide environmental tolerance, the regional adaptability of the potential biofuel crop switch grass varies considerably. Therefore, it is important to regionally quantify the GHG emissions and crop yield in response to N-fertilization. A major objective of this study is to quantify soil emissions of N2O from switchgrass and corn fields as a function of N-fertilization. The roles of soil moisture and soil temperature on N2O fluxes were analyzed. These N2O observations may be used to parameterize the biogeochemical models to better understand the impact of different N2O emission scenarios. This study allows for improvements in climate models that focus on understanding the environmental impacts of the climate change mitigation strategy of replacing fossil fuels with biofuels. As a second major objective, the top of the

  9. Overview of the Capstone Depleted Uranium Study of Aerosols from Impact with Armored Vehicles: Test Setup and Aerosol Generation, Characterization, and Application in Assessing Dose and Risk

    International Nuclear Information System (INIS)

    Parkhurst, MaryAnn; Guilmette, Raymond A.

    2009-01-01

    The Capstone Depleted Uranium (DU) Aerosol Characterization and Risk Assessment Study was conducted to generate data about DU aerosols generated during the perforation of armored combat vehicles with large-caliber DU penetrators, and to apply the data in assessments of human health risks to personnel exposed to these aerosols, primarily through inhalation, during the 1991 Gulf War or in future military operations. The Capstone study consisted of two components: (1) generating, sampling and characterizing DU aerosols by firing at and perforating combat vehicles and (2) applying the source-term quantities and characteristics of the aerosols to the evaluation of doses and risks. This paper reviews the background of the study including the bases for the study, previous reviews of DU particles and health assessments from DU used by the U.S. military, the objectives of the study components, the participants and oversight teams, and the types of exposures it was intended to evaluate. It then discusses exposure scenarios used in the dose and risk assessment and provides an overview of how the field tests and dose and risk assessments were conducted

  10. Oxidative potential of secondary organic aerosols produced from photooxidation of different hydrocarbons using outdoor chamber under ambient sunlight

    Science.gov (United States)

    Jiang, Huanhuan; Jang, Myoseon; Sabo-Attwood, Tara; Robinson, Sarah E.

    2016-04-01

    The oxidative potential of various secondary organic aerosols (SOA) was measured using dithiothreitol (DTT) assay to understand how organic aerosols react with cellular materials. SOA was produced via the photooxidation of four different hydrocarbons (toluene, 1,3,5-trimethylbenzene, isoprene and α-pinene) in the presence of NOx using a large outdoor photochemical smog chamber. The DTT consumption rate was normalized by the aerosol mass, which is expressed as DTTmass. Toluene SOA and isoprene SOA yielded higher DTTmass than 1,3,5-trimethylbenzene SOA or α-pinene SOA. In order to discover the correlation between the molecular structure and oxidative potential, the DTT responses of selected model compounds were also measured. Among them, conjugated aldehydes, quinones, and H2O2 showed considerable DTT response. To investigate the correlation between DTT response and cell responses in vitro, the expression of biological markers, i.e. IL-6, IL-8, and HMOX-1 were studied using small airway epithelial cells. Higher cellular expression of IL-8 was observed with toluene SOA exposure compared to 1,3,5-trimethylbenzene SOA exposure, which aligned with the results from DTT assay. Our study also suggests that within the urban atmosphere, the contribution of toluene SOA and isoprene SOA to the oxidative potential of ambient SOA will be more significant than that of α-pinene SOA.

  11. Nitrate radical oxidation of γ-terpinene: hydroxy nitrate, total organic nitrate, and secondary organic aerosol yields

    Science.gov (United States)

    Slade, Jonathan H.; de Perre, Chloé; Lee, Linda; Shepson, Paul B.

    2017-07-01

    Polyolefinic monoterpenes represent a potentially important but understudied source of organic nitrates (ONs) and secondary organic aerosol (SOA) following oxidation due to their high reactivity and propensity for multi-stage chemistry. Recent modeling work suggests that the oxidation of polyolefinic γ-terpinene can be the dominant source of nighttime ON in a mixed forest environment. However, the ON yields, aerosol partitioning behavior, and SOA yields from γ-terpinene oxidation by the nitrate radical (NO3), an important nighttime oxidant, have not been determined experimentally. In this work, we present a comprehensive experimental investigation of the total (gas + particle) ON, hydroxy nitrate, and SOA yields following γ-terpinene oxidation by NO3. Under dry conditions, the hydroxy nitrate yield = 4(+1/-3) %, total ON yield = 14(+3/-2) %, and SOA yield ≤ 10 % under atmospherically relevant particle mass loadings, similar to those for α-pinene + NO3. Using a chemical box model, we show that the measured concentrations of NO2 and γ-terpinene hydroxy nitrates can be reliably simulated from α-pinene + NO3 chemistry. This suggests that NO3 addition to either of the two internal double bonds of γ-terpinene primarily decomposes forming a relatively volatile keto-aldehyde, reconciling the small SOA yield observed here and for other internal olefinic terpenes. Based on aerosol partitioning analysis and identification of speciated particle-phase ON applying high-resolution liquid chromatography-mass spectrometry, we estimate that a significant fraction of the particle-phase ON has the hydroxy nitrate moiety. This work greatly contributes to our understanding of ON and SOA formation from polyolefin monoterpene oxidation, which could be important in the northern continental US and the Midwest, where polyolefinic monoterpene emissions are greatest.

  12. Comparison of computer codes related to the sodium oxide aerosol behavior in a containment building

    International Nuclear Information System (INIS)

    Fermandjian, J.

    1984-09-01

    In order to ensure that the problems of describing the physical behavior of sodium aerosols, during hypothetical fast reactor accidents, were adequately understood, a comparison of the computer codes (ABC/INTG, PNC, Japan; AEROSIM, UKAEA/SRD, United Kingdom; PARDISEKO IIIb, KfK, Germany; AEROSOLS/A2 and AEROSOLS/B1, CEA France) was undertaken in the frame of the CEC: exercise in which code users have run their own codes with a prearranged input

  13. Field characterization of plutonium aerosols in mixed-oxide fuel fabrication

    International Nuclear Information System (INIS)

    Newton, G.J.; Teague, S.V.; Yeh, H.C.

    1976-01-01

    Nuclear reactor fuel pellets of PuO 2 and UO 2 are fabricated within safety enclosures at Babcock and Wilcox's Parker Township Site near Apolla, Pa. Nineteen sample runs were taken from within glove boxes of aerosols formed during powder comminution and blending. Eight sampling runs were also taken of a centerless grinding operation during routine industrial operations. A small seven-stage cascade impactor and the Lovelace Aerosol Particle Separator (LAPS) were used to determine aerodynamic size distribution and gross alpha aerosol concentrations. The potential toxicity of inhaled plutonium originating in the nuclear fuel cycle following accidental releases of these aerosols and possible inhalation by industrial workers is considered

  14. Characterization of aerosols from industrial fabrication of mixed-oxide nuclear reactor fuels

    International Nuclear Information System (INIS)

    Hoover, M.D.; Newton, G.J.

    1997-01-01

    Recycling plutonium into mixed-oxide (MOX) fuel for nuclear reactors is being given serious consideration as a safe and environmentally sound method of managing plutonium from weapons programs. Planning for the proper design and safe operation of the MOX fuel fabrication facilities can take advantage of studies done in the 1970s, when recycling of plutonium from nuclear fuel was under serious consideration. At that time, it was recognized that the recycle of plutonium and uranium in irradiated fuel could provide a significant energy source and that the use of 239 Pu in light water reactor fuel would reduce the requirements for enriched 235 U as a reactor fuel. It was also recognized that the fabrication of uranium and plutonium reactor fuels would not be risk-free. Despite engineered safety precautions such as the handling of uranium and plutonium in glove-box enclosures, accidental releases of radioactive aerosols from normal containment might occur. Workers might then be exposed to the released materials by inhalation

  15. Aerosol studies

    International Nuclear Information System (INIS)

    Cristy, G.A.; Fish, M.E.

    1978-01-01

    As part of the continuing studies of the effects of very severe reactor accidents, an effort was made to develop, test, and improve simple, effective, and inexpensive methods by which the average citizen, using only materials readily available, could protect his residence, himself, and his family from injury by toxic aerosols. The methods for protection against radioactive aerosols should be equally effective against a clandestine biological attack by terrorists. The results of the tests to date are limited to showing that spores of the harmless bacterium, bacillus globegii (BG), can be used as a simulant for the radioactive aerosols. An aerosol generator of Lauterbach type was developed which will produce an essentially monodisperse aerosol at the rate of 10 9 spores/min. Analytical techniques have been established which give reproducible results. Preliminary field tests have been conducted to check out the components of the system. Preliminary tests of protective devices, such as ordinary vacuum sweepers, have given protection factors of over 1000

  16. Assessing the degree of plug flow in oxidation flow reactors (OFRs): a study on a potential aerosol mass (PAM) reactor

    Science.gov (United States)

    Mitroo, Dhruv; Sun, Yujian; Combest, Daniel P.; Kumar, Purushottam; Williams, Brent J.

    2018-03-01

    Oxidation flow reactors (OFRs) have been developed to achieve high degrees of oxidant exposures over relatively short space times (defined as the ratio of reactor volume to the volumetric flow rate). While, due to their increased use, attention has been paid to their ability to replicate realistic tropospheric reactions by modeling the chemistry inside the reactor, there is a desire to customize flow patterns. This work demonstrates the importance of decoupling tracer signal of the reactor from that of the tubing when experimentally obtaining these flow patterns. We modeled the residence time distributions (RTDs) inside the Washington University Potential Aerosol Mass (WU-PAM) reactor, an OFR, for a simple set of configurations by applying the tank-in-series (TIS) model, a one-parameter model, to a deconvolution algorithm. The value of the parameter, N, is close to unity for every case except one having the highest space time. Combined, the results suggest that volumetric flow rate affects mixing patterns more than use of our internals. We selected results from the simplest case, at 78 s space time with one inlet and one outlet, absent of baffles and spargers, and compared the experimental F curve to that of a computational fluid dynamics (CFD) simulation. The F curves, which represent the cumulative time spent in the reactor by flowing material, match reasonably well. We value that the use of a small aspect ratio reactor such as the WU-PAM reduces wall interactions; however sudden apertures introduce disturbances in the flow, and suggest applying the methodology of tracer testing described in this work to investigate RTDs in OFRs to observe the effect of modified inlets, outlets and use of internals prior to application (e.g., field deployment vs. laboratory study).

  17. Assessing the degree of plug flow in oxidation flow reactors (OFRs: a study on a potential aerosol mass (PAM reactor

    Directory of Open Access Journals (Sweden)

    D. Mitroo

    2018-03-01

    Full Text Available Oxidation flow reactors (OFRs have been developed to achieve high degrees of oxidant exposures over relatively short space times (defined as the ratio of reactor volume to the volumetric flow rate. While, due to their increased use, attention has been paid to their ability to replicate realistic tropospheric reactions by modeling the chemistry inside the reactor, there is a desire to customize flow patterns. This work demonstrates the importance of decoupling tracer signal of the reactor from that of the tubing when experimentally obtaining these flow patterns. We modeled the residence time distributions (RTDs inside the Washington University Potential Aerosol Mass (WU-PAM reactor, an OFR, for a simple set of configurations by applying the tank-in-series (TIS model, a one-parameter model, to a deconvolution algorithm. The value of the parameter, N, is close to unity for every case except one having the highest space time. Combined, the results suggest that volumetric flow rate affects mixing patterns more than use of our internals. We selected results from the simplest case, at 78 s space time with one inlet and one outlet, absent of baffles and spargers, and compared the experimental F curve to that of a computational fluid dynamics (CFD simulation. The F curves, which represent the cumulative time spent in the reactor by flowing material, match reasonably well. We value that the use of a small aspect ratio reactor such as the WU-PAM reduces wall interactions; however sudden apertures introduce disturbances in the flow, and suggest applying the methodology of tracer testing described in this work to investigate RTDs in OFRs to observe the effect of modified inlets, outlets and use of internals prior to application (e.g., field deployment vs. laboratory study.

  18. Automated aerosol sampling and analysis for the Comprehensive Test Ban Treaty

    International Nuclear Information System (INIS)

    Miley, H.S.; Bowyer, S.M.; Hubbard, C.W.; McKinnon, A.D.; Perkins, R.W.; Thompson, R.C.; Warner, R.A.

    1998-01-01

    Detecting nuclear debris from a nuclear weapon exploded in or substantially vented to the Earth's atmosphere constitutes the most certain indication that a violation of the Comprehensive Test Ban Treaty has occurred. For this reason, a radionuclide portion of the International Monitoring System is being designed and implemented. The IMS will monitor aerosols and gaseous xenon isotopes to detect atmospheric and underground tests, respectively. An automated system, the Radionuclide Aerosol Sampler/Analyzer (RASA), has been developed at Pacific Northwest National Laboratory to meet CTBT aerosol measurement requirements. This is achieved by the use of a novel sampling apparatus, a high-resolution germanium detector, and very sophisticated software. This system draws a large volume of air (∼ 20,000 m 3 /day), performs automated gamma-ray spectral measurements (MDC( 140 Ba) 3 ), and communicates this and other data to a central data facility. Automated systems offer the added benefit of rigid controls, easily implemented QA/QC procedures, and centralized depot maintenance and operation. Other types of automated communication include pull or push transmission of State-Of-Health data, commands, and configuration data. In addition, a graphical user interface, Telnet, and other interactive communications are supported over ordinary phone or network lines. This system has been the subject of a USAF commercialization effort to meet US CTBT monitoring commitments. It will also be available to other CTBT signatories and the monitoring community for various governmental, environmental, or commercial needs. The current status of the commercialization is discussed

  19. Laboratory Measurements of Biomass Cook-stove Emissions Aged in an Oxidation Flow Reactor: Influence of Combustion and Aging Conditions on Aerosols

    Science.gov (United States)

    Grieshop, A. P.; Reece, S. M.; Sinha, A.; Wathore, R.

    2016-12-01

    Combustion in rudimentary and improved cook-stoves used by billions in developing countries can be a regionally dominant contributor to black carbon (BC), primary organic aerosols (POA) and precursors for secondary organic aerosol (SOA). Recent studies suggest that SOA formed during photo-oxidation of primary emissions from biomass burning may make important contribution to its atmospheric impacts. However, the extent to which stove type and operating conditions affect the amount, composition and characteristics of SOA formed from the aging of cookstoves emissions is still largely undetermined. Here we present results from experiments with a field portable oxidation flow reactor (F-OFR) designed to assess aging of cook-stove emissions in both laboratory and field settings. Laboratory tests results are used to compare the quantity and properties of fresh and aged emissions from a traditional open fire and twp alternative stove designs operated on the standard and alternate testing protocols. Diluted cookstove emissions were exposed to a range of oxidant concentrations in the F-OFR. Primary emissions were aged both on-line, to study the influence of combustion variability, and sampled from batched emissions in a smog chamber to examine different aging conditions. Data from real-time particle- and gas-phase instruments and integrated filter samples were collected up and down stream of the OFR. The properties of primary emissions vary strongly with stove type and combustion conditions (e.g. smoldering versus flaming). Experiments aging diluted biomass emissions from distinct phases of stove operation (smoldering and flaming) showed peak SOA production for both phases occurred between 3 and 6 equivalent days of aging with slightly greater production observed in flaming phase emissions. Changing combustion conditions had a stronger influence than aging on POA+SOA `emission factors'. Aerosol Chemical Speciation Monitor data show a substantial evolution of aerosol

  20. Secondary organic aerosol formation from in situ OH, O3, and NO3 oxidation of ambient forest air in an oxidation flow reactor

    Science.gov (United States)

    Palm, Brett B.; Campuzano-Jost, Pedro; Day, Douglas A.; Ortega, Amber M.; Fry, Juliane L.; Brown, Steven S.; Zarzana, Kyle J.; Dube, William; Wagner, Nicholas L.; Draper, Danielle C.; Kaser, Lisa; Jud, Werner; Karl, Thomas; Hansel, Armin; Gutiérrez-Montes, Cándido; Jimenez, Jose L.

    2017-04-01

    Ambient pine forest air was oxidized by OH, O3, or NO3 radicals using an oxidation flow reactor (OFR) during the BEACHON-RoMBAS (Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics and Nitrogen - Rocky Mountain Biogenic Aerosol Study) campaign to study biogenic secondary organic aerosol (SOA) formation and organic aerosol (OA) aging. A wide range of equivalent atmospheric photochemical ages was sampled, from hours up to days (for O3 and NO3) or weeks (for OH). Ambient air processed by the OFR was typically sampled every 20-30 min, in order to determine how the availability of SOA precursor gases in ambient air changed with diurnal and synoptic conditions, for each of the three oxidants. More SOA was formed during nighttime than daytime for all three oxidants, indicating that SOA precursor concentrations were higher at night. At all times of day, OH oxidation led to approximately 4 times more SOA formation than either O3 or NO3 oxidation. This is likely because O3 and NO3 will only react with gases containing C = C bonds (e.g., terpenes) to form SOA but will not react appreciably with many of their oxidation products or any species in the gas phase that lacks a C = C bond (e.g., pinonic acid, alkanes). In contrast, OH can continue to react with compounds that lack C = C bonds to produce SOA. Closure was achieved between the amount of SOA formed from O3 and NO3 oxidation in the OFR and the SOA predicted to form from measured concentrations of ambient monoterpenes and sesquiterpenes using published chamber yields. This is in contrast to previous work at this site (Palm et al., 2016), which has shown that a source of SOA from semi- and intermediate-volatility organic compounds (S/IVOCs) 3.4 times larger than the source from measured VOCs is needed to explain the measured SOA formation from OH oxidation. This work suggests that those S/IVOCs typically do not contain C = C bonds. O3 and NO3 oxidation produced SOA with elemental O : C and H : C

  1. Local transport of vertically- and horizontally-emitted sodium oxide aerosols

    International Nuclear Information System (INIS)

    Fields, D.E.; Miller, C.W.; Cooper, A.C.

    1986-01-01

    Liquid-metal cooled breeder reactors are expected to use large quantities of sodium or sodium-potassium alloy, and evaluation of the possible consequences of a liquid-metal fire, henceforth referred to as a sodium fire, is an important consideration. Of particular interest is the sodium aerosol concentration at the air intake ports that are used for reactor cooling, and which might suffer restricted flow under high aerosol concentrations. We have devised and applied a methodology for estimating the concentration of aerosols released vertically and horizontally from building surfaces and monitored at other building surface points. We have used this methodology to make calculations that indicate the time-development of aerosol build-up, and the maximum aerosol concentrations, at air intake ports. Building wake effects, momentum-driven plume rise, and density-driven plume rise are considered

  2. Analysis of the heat and mass transfer processes of a UO2 bubble in sodium for the Fuel Aerosol Simulant Test (FAST)

    International Nuclear Information System (INIS)

    Tobias, M.L.

    1979-01-01

    The anticipated behavior of uranium oxide vapor bubbles produced by the capacitor discharge vaporization (CDV) method in the Fuel Aerosol Simulant Test (FAST) Facility is discussed on the basis of relatively simple physical models. Results of calculations for the rate of bubble rise and for heat and mass transfer rates are presented. Parametric studies indicate that future analysis efforts should emphasize the diffusion condensation process and the loss of heat from the bubble by radiation. Transfer of heat in the surrounding sodium is rapid enough that simplified models should be adequate. No important effects were noted in connection with bubble depth, initial quantity of UO 2 , or initial superheat

  3. Laboratory Experiments and Modeling for Interpreting Field Studies of Secondary Organic Aerosol Formation Using an Oxidation Flow Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, Jose-Luis [Univ. of Colorado, Boulder, CO (United States)

    2016-02-01

    This grant was originally funded for deployment of a suite of aerosol instrumentation by our group in collaboration with other research groups and DOE/ARM to the Ganges Valley in India (GVAX) to study aerosols sources and processing. Much of the first year of this grant was focused on preparations for GVAX. That campaign was cancelled due to political reasons and with the consultation with our program manager, the research of this grant was refocused to study the applications of oxidation flow reactors (OFRs) for investigating secondary organic aerosol (SOA) formation and organic aerosol (OA) processing in the field and laboratory through a series of laboratory and modeling studies. We developed a gas-phase photochemical model of an OFR which was used to 1) explore the sensitivities of key output variables (e.g., OH exposure, O3, HO2/OH) to controlling factors (e.g., water vapor, external reactivity, UV irradiation), 2) develop simplified OH exposure estimation equations, 3) investigate under what conditions non-OH chemistry may be important, and 4) help guide design of future experiments to avoid conditions with undesired chemistry for a wide range of conditions applicable to the ambient, laboratory, and source studies. Uncertainties in the model were quantified and modeled OH exposure was compared to tracer decay measurements of OH exposure in the lab and field. Laboratory studies using OFRs were conducted to explore aerosol yields and composition from anthropogenic and biogenic VOC as well as crude oil evaporates. Various aspects of the modeling and laboratory results and tools were applied to interpretation of ambient and source measurements using OFR. Additionally, novel measurement methods were used to study gas/particle partitioning. The research conducted was highly successful and details of the key results are summarized in this report through narrative text, figures, and a complete list of publications acknowledging this grant.

  4. Heterogeneous Oxidation of Atmospheric Organic Aerosol: Kinetics of Changes to the Amount and Oxidation State of Particle-Phase Organic Carbon.

    Science.gov (United States)

    Kroll, Jesse H; Lim, Christopher Y; Kessler, Sean H; Wilson, Kevin R

    2015-11-05

    Atmospheric oxidation reactions are known to affect the chemical composition of organic aerosol (OA) particles over timescales of several days, but the details of such oxidative aging reactions are poorly understood. In this study we examine the rates and products of a key class of aging reaction, the heterogeneous oxidation of particle-phase organic species by the gas-phase hydroxyl radical (OH). We compile and reanalyze a number of previous studies from our laboratories involving the oxidation of single-component organic particles. All kinetic and product data are described on a common basis, enabling a straightforward comparison among different chemical systems and experimental conditions. Oxidation chemistry is described in terms of changes to key ensemble properties of the OA, rather than to its detailed molecular composition, focusing on two quantities in particular, the amount and the oxidation state of the particle-phase carbon. Heterogeneous oxidation increases the oxidation state of particulate carbon, with the rate of increase determined by the detailed chemical mechanism. At the same time, the amount of particle-phase carbon decreases with oxidation, due to fragmentation (C-C scission) reactions that form small, volatile products that escape to the gas phase. In contrast to the oxidation state increase, the rate of carbon loss is nearly uniform among most systems studied. Extrapolation of these results to atmospheric conditions indicates that heterogeneous oxidation can have a substantial effect on the amount and composition of atmospheric OA over timescales of several days, a prediction that is broadly in line with available measurements of OA evolution over such long timescales. In particular, 3-13% of particle-phase carbon is lost to the gas phase after one week of heterogeneous oxidation. Our results indicate that oxidative aging represents an important sink for particulate organic carbon, and more generally that fragmentation reactions play a major

  5. Diffusive deposition of aerosols in Phebus containment during FPT-2 test

    International Nuclear Information System (INIS)

    Kontautas, A.; Urbonavicius, E.

    2012-01-01

    At present the lumped-parameter codes is the main tool to investigate the complex response of the containment of Nuclear Power Plant in case of an accident. Continuous development and validation of the codes is required to perform realistic investigation of the processes that determine the possible source term of radioactive products to the environment. Validation of the codes is based on the comparison of the calculated results with the measurements performed in experimental facilities. The most extensive experimental program to investigate fission product release from the molten fuel, transport through the cooling circuit and deposition in the containment is performed in PHEBUS test facility. Test FPT-2 performed in this facility is considered for analysis of processes taking place in containment. Earlier performed investigations using COCOSYS code showed that the code could be successfully used for analysis of thermal-hydraulic processes and deposition of aerosols, but there was also noticed that diffusive deposition on the vertical walls does not fit well with the measured results. In the CPA module of ASTEC code there is implemented different model for diffusive deposition, therefore the PHEBUS containment model was transferred from COCOSYS code to ASTEC-CPA to investigate the influence of the diffusive deposition modelling. Analysis was performed using PHEBUS containment model of 16 nodes. The calculated thermal-hydraulic parameters are in good agreement with measured results, which gives basis for realistic simulation of aerosol transport and deposition processes. Performed investigations showed that diffusive deposition model has influence on the aerosol deposition distribution on different surfaces in the test facility. (authors)

  6. Current Status of Aerosol Generation and Measurement Facilities for the Verification Test of Containment Filtered Venting System in KAERI

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Il; An, Sang Mo; Ha, Kwang Soon; Kim, Hwan Yeol [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    In this study, the design of aerosol generation and measurement systems are explained and present circumstances are also described. In addition, the aerosol test plan is shown. Containment Filtered Venting System (FCVS) is one of the safety features to reduce the amount of released fission product into the environment by depressurizing the containment. Since Chernobyl accident, the regulatory agency in several countries in Europe such as France, Germany, Sweden, etc. have been demanded the installation of the CFVS. Moreover, the feasibility study on the CFVS was also performed in U.S. After the Fukushima accident, there is a need to improve a containment venting or installation of depressurizing facility in Korea. As a part of a Ministry of Trade, Industry and Energy (MOTIE) project, KAERI has been conducted the integrated performance verification test of CFVS. As a part of the test, aerosol generation system and measurement systems were designed to simulate the fission products behavior. To perform the integrated verification test of CFVS, aerosol generation and measurement system was designed and manufactured. The component operating condition is determined to consider the severe accident condition. The test will be performed in normal conditions at first, and will be conducted under severe condition, high pressure and high temperature. Undesirable difficulties which disturb the elaborate test are expected, such as thermophoresis on the pipe, vapor condensation on aerosol, etc.

  7. Improvement of the CULTEX® exposure technology by radial distribution of the test aerosol.

    Science.gov (United States)

    Aufderheide, Michaela; Heller, Wolf-Dieter; Krischenowski, Olaf; Möhle, Niklas; Hochrainer, Dieter

    2017-07-05

    The exposure of cellular based systems cultivated on microporous membranes at the air-liquid interface (ALI) has been accepted as an appropriate approach to simulate the exposure of cells of the respiratory tract to native airborne substances. The efficiency of such an exposure procedure with regard to stability and reproducibility depends on the optimal design at the interface between the cellular test system and the exposure technique. The actual exposure systems favor the dynamic guidance of the airborne substances to the surface of the cells in specially designed exposure devices. Two module types, based on a linear or radial feed of the test atmosphere to the test system, were used for these studies. In our technical history, the development started with the linear designed version, the CULTEX ® glass modules, fulfilling basic requirements for running ALI exposure studies (Mohr and Durst, 2005). The instability in the distribution of different atmospheres to the cells caused us to create a new exposure module, characterized by a stable and reproducible radial guidance of the aerosol to the cells. The outcome was the CULTEX ® RFS (Mohr et al., 2010). In this study, we describe the differences between the two systems with regard to particle distribution and deposition clarifying the advantages and disadvantages of a radial to a linear aerosol distribution concept. Copyright © 2017 Elsevier GmbH. All rights reserved.

  8. The oxidation of SO2 by NO2(g) at the air-water interface of aquated aerosol: implications for the rapid onset of haze-aerosol events in China

    Science.gov (United States)

    Li, L.; Colussi, A. J.; Hoffmann, M. R.

    2017-12-01

    Aqueous phase chemistry plays a vital role in the global atmosphere. The importance of heterogeneous chemistry has been recently underscored by the severe haze-fog pollution episodes experienced in Chinese megacities. A key finding is that despite reduced photochemistry during the wintertime haze events, the oxidation of S(IV) into sulfate aerosol occurs rapidly in spite of the low levels of ozone and H2O2. Field observations suggest that NO2 could serve as a suitable oxidant of S(IV) during the events under neutral pH conditions. However, the haze aerosols are mostly acidic. Furthermore, the air-water interface is more acidic than bulk-phase aquated system according to our recent findings. This work investigates the chemistry taking place as NO2(g) collides with the surface of aqueous S(IV) microdroplets as a function of pH to closely simulate actual haze aerosol events under atmospheric conditions. The reaction between NO2(g) and HSO3- (aq) is studied in situ under ambient temperature and pressure via online electrospray ionization mass spectrometry. The aqueous aerosols containing HSO3- is generated using a microjet which is exposed to NO2(g) alternatively, while the composition of the 1 nm interfacial liquid layer of the aerosol is instantaneously measured. The ratio of HSO3- to HSO4- is observed to decrease with the concomitant appearance of a strong m/z 62 signal upon NO2(g) exposure. The appearance of m/z 62 indicates the formation of NO3- via the disproportionation of NO2 (2NO2(g) + H2O (l) ⇌ H++NO3-(aq) + HONO(aq)) and thus impacts the ion-ion interactions of NO3- on the ratio of HSO3- to HSO4- in the outermost interfacial layers. Parallel experiments with NO3-(aq) additions are conducted to quantify the impact of NO3- on the the ratio, in order to unravel the contribution of NO2 to the oxidation of S(IV). After accounting for the HNO3 effect, it is concluded: (1) most NO2(g) is converted into NO3- via anion-catalyzed hydrolytic disproportionation; (2

  9. Cobalt-60 oxide aerosols: methods of production and short-term retention and distribution kinetics in the beagle dog

    International Nuclear Information System (INIS)

    Barnes, J.E.; Kanapilly, G.M.; Newton, G.J.

    1976-01-01

    Cobalt-60 has been used extensively in nuclear applications and has been considered for use in nuclear auxiliary power devices. The most common chemical form used is the oxide. This study of the retention and distribution of two differnt exoides of cobalt when administered by inhalation was conducted to assess the potential inhalation hazard associated with its use. Cobaltosic oxide (Co 3 O 4 ) was formed by passing a cobalt nitrate aerosol through a heating column at 850 0 C before delivery to the dog. Cobaltous oxide (CoO) was formed by raising the heating column temperature to 1400 0 C. Three beagle dogs were exposed to 60 Co 3 O 4 and sacrificed singly at 8, 64 and 128 days. Three beagle dogs were exposed to 60 CoO and sacrificed at 8, 16 and 64 days after exposure. Whole-body retention patterns showed that 60 CoO left the body with a shorter effective half-life than 60 Co 3 O 4 . The concentration of 60 Co detected in the blood was at least an order of magnitude higher in the dogs exposed to 60 CoO than in the dogs exposed to 60 Co 3 O 4 . Cobalt-60 translocated from the lung accumulated predominantly in the kidney, liver, skeleton and cartilagenous structures such as the trachea. Higher concentrations were reached earlier in the dogs exposed to 60 CoO. After early fecal excretion of material deposited in the upper respiratory tract, excretion was greatest via the urine. The higher solubility of the 60 CoO formed at 1400 0 C relative to 60 Co 3 O 4 formed at 850 0 C is noteworthy considering that generally aerosols formed at higher temperatures are more insoluble than aerosols formed at lower temperatures. (author)

  10. A new method for in-situ filter testing using pulses of aerosol and photometric detection with computer control

    International Nuclear Information System (INIS)

    Marshall, P.R.C.; Bosley, R.B.

    1993-01-01

    This paper describes a new technique, developed at the Harwell Laboratory, for the in-situ testing of High Efficiency Particulate Air (HEPA) filters using multiple pulses of test aerosol. The pulse test apparatus consists of a modified forward light scattering photometer coupled to a portable micro-computer fitted with an external data acquisition and control card. The micro-computer switches an aerosol generator on and off via an external relay driver unit. Using this apparatus the filter bank is challenged by a small number of equal length, constant concentration, pulses of aerosol at timed intervals. The aerosol concentration data upstream of the filter bank is logged, to disk, by the computer. The process is then repeated for the downstream concentration with the photometer gain increased to give maximum sensitivity. The collected data is analysed using a computer spread-sheet package; the recorded aerosol pulses are combined, integrated and the background data subtracted; the downstream data is then divided by the upstream pulse data to give the filter penetration. Using this technique the sensitivity of the in-situ filter test has been greatly improved, penetrations approaching 10 -5 % can now be measured, allowing HEPA filters mounted in series to be successfully tested. In addition, filter loading is reduced considerably

  11. Defect-induced magnetism in undoped and Mn-doped wide band gapzinc oxide grown by aerosol spray pyrolysis

    CSIR Research Space (South Africa)

    Motaung, DE

    2014-08-01

    Full Text Available Surface Science Vol. 311, pp 14-26 Defect-induced magnetism in undoped and Mn-doped wide band gapzinc oxide grown by aerosol spray pyrolysis D.E. Motaunga,∗, I. Kortidise, D. Papadakie, S.S. Nkosib,∗∗, G.H. Mhlongoa,J. Wesley-Smitha, G.F. Malgasc, B....W. Mwakikungaa, E. Coetseed, H.C. Swartd,G. Kiriakidise,f, S.S. Raya aDST/CSIR Nanotechnology Innovation Centre, National Centre for Nano-Structured Materials, Council for Scientific and Industrial Research, P.O. Box 395,Pretoria 0001, South Africa b...

  12. Relevant climate response tests for stratospheric aerosol injection: A combined ethical and scientific analysis

    Science.gov (United States)

    Lenferna, Georges Alexandre; Russotto, Rick D.; Tan, Amanda; Gardiner, Stephen M.; Ackerman, Thomas P.

    2017-06-01

    In this paper, we focus on stratospheric sulfate injection as a geoengineering scheme, and provide a combined scientific and ethical analysis of climate response tests, which are a subset of outdoor tests that would seek to impose detectable and attributable changes to climate variables on global or regional scales. We assess the current state of scientific understanding on the plausibility and scalability of climate response tests. Then, we delineate a minimal baseline against which to consider whether certain climate response tests would be relevant for a deployment scenario. Our analysis shows that some climate response tests, such as those attempting to detect changes in regional climate impacts, may not be deployable in time periods relevant to realistic geoengineering scenarios. This might pose significant challenges for justifying stratospheric sulfate aerosol injection deployment overall. We then survey some of the major ethical challenges that proposed climate response tests face. We consider what levels of confidence would be required to ethically justify approving a proposed test; whether the consequences of tests are subject to similar questions of justice, compensation, and informed consent as full-scale deployment; and whether questions of intent and hubris are morally relevant for climate response tests. We suggest further research into laboratory-based work and modeling may help to narrow the scientific uncertainties related to climate response tests, and help inform future ethical debate. However, even if such work is pursued, the ethical issues raised by proposed climate response tests are significant and manifold.

  13. Novel pathway of SO2 oxidation in the atmosphere: reactions with monoterpene ozonolysis intermediates and secondary organic aerosol

    Science.gov (United States)

    Ye, Jianhuai; Abbatt, Jonathan P. D.; Chan, Arthur W. H.

    2018-04-01

    Ozonolysis of monoterpenes is an important source of atmospheric biogenic secondary organic aerosol (BSOA). While enhanced BSOA formation has been associated with sulfate-rich conditions, the underlying mechanisms remain poorly understood. In this work, the interactions between SO2 and reactive intermediates from monoterpene ozonolysis were investigated under different humidity conditions (10 % vs. 50 %). Chamber experiments were conducted with ozonolysis of α-pinene or limonene in the presence of SO2. Limonene SOA formation was enhanced in the presence of SO2, while no significant changes in SOA yields were observed during α-pinene ozonolysis. Under dry conditions, SO2 primarily reacted with stabilized Criegee intermediates (sCIs) produced from ozonolysis, but at 50 % RH heterogeneous uptake of SO2 onto organic aerosol was found to be the dominant sink of SO2, likely owing to reactions between SO2 and organic peroxides. This SO2 loss mechanism to organic peroxides in SOA has not previously been identified in experimental chamber studies. Organosulfates were detected and identified using an electrospray ionization-ion mobility spectrometry-high-resolution time-of-flight mass spectrometer (ESI-IMS-TOF) when SO2 was present in the experiments. Our results demonstrate the synergistic effects between BSOA formation and SO2 oxidation through sCI chemistry and SO2 uptake onto organic aerosol and illustrate the importance of considering the chemistry of organic and sulfur-containing compounds holistically to properly account for their reactive sinks.

  14. "UCx fission targets oxidation test stand"

    CERN Document Server

    Lacroix, Rachel

    2014-01-01

    "Set up a rig dedicated to the oxidation of UCx and define a procedure for repeatable, reliable and safe method for converting UC2 fission targets into an acceptable uranium carbide oxide waste for subsequent disposal by the Swiss Authorities."

  15. Superparamagnetic iron oxide nanoparticles (SPIONs)-loaded Trojan microparticles for targeted aerosol delivery to the lung.

    Science.gov (United States)

    Tewes, Frederic; Ehrhardt, Carsten; Healy, Anne Marie

    2014-01-01

    Targeted aerosol delivery to specific regions of the lung may improve therapeutic efficiency and minimise unwanted side effects. Targeted delivery could potentially be achieved with porous microparticles loaded with superparamagnetic iron oxide nanoparticles (SPIONs)-in combination with a target-directed magnetic gradient field. The aim of this study was to formulate and evaluate the aerodynamic properties of SPIONs-loaded Trojan microparticles after delivery from a dry powder inhaler. Microparticles made of SPIONs, PEG and hydroxypropyl-β-cyclodextrin (HPβCD) were formulated by spray drying and characterised by various physicochemical methods. Aerodynamic properties were evaluated using a next generation cascade impactor (NGI), with or without a magnet positioned at stage 2. Mixing appropriate proportions of SPIONs, PEG and HPβCD allowed Trojan microparticle to be formulated. These particles had a median geometric diameter of 2.8±0.3μm and were shown to be sensitive to the magnetic field induced by a magnet having a maximum energy product of 413.8kJ/m(3). However, these particles, characterised by a mass median aerodynamic diameter (MMAD) of 10.2±2.0μm, were considered to be not inhalable. The poor aerodynamic properties resulted from aggregation of the particles. The addition of (NH4)2CO3 and magnesium stearate (MgST) to the formulation improved the aerodynamic properties of the Trojan particles and resulted in a MMAD of 2.2±0.8μm. In the presence of a magnetic field on stage 2 of the NGI, the amount of particles deposited at this stage increased 4-fold from 4.8±0.7% to 19.5±3.3%. These Trojan particles appeared highly sensitive to the magnetic field and their deposition on most of the stages of the NGI was changed in the presence compared to the absence of the magnet. If loaded with a pharmaceutical active ingredient, these particles may be useful for treating localised lung disease such as cancer nodules or bacterial infectious foci. Copyright

  16. A study of the comparison between human and animal excretion data following inhalation exposure to plutonium 238 oxide aerosols

    International Nuclear Information System (INIS)

    Moss, W.D.; Martinez, G.; Gautier, M.A.

    1985-01-01

    Bioassay urine samples obtained since 1971 from eight Los Alamos employees, accidentally exposed by inhalation to high-fired plutonium-238 oxide aerosols, were studied and compared with excretion data obtained from Beagle dogs exposed to /sup 238/PuO/sub 2/ aerosols. The early period Pu human excretion data from the inhalation exposure were unexpected and were unlike previously studied occupational exposure urinary data obtained at Los Alamos. The initial urine samples collected on day one were below the detection limits of the analytical method (0.01 pCi). Within thirty days, however, detectible concentrations of Pu were measured in the urine for several of the exposed personnel. The amounts of Pu excreted continued to increase in each of the cases throughout the first year and the individual patterns of Pu excretion were similar. The human urinary excretion data was compared with similar excretion data obtained from an animal study conducted by the Inhalation Toxicology Research Institute (Me81). In the animal study, Beagle dogs received inhalation exposure to one of three sizes of monodisperse of polydisperse aerosol of /sup 238/PuO/sub 2/. Periodic sacrifice of pairs of dogs during the 4 years after the inhalation exposure provided data on the retention, translocation and mode of excretion of /sup 238/Pu. The comparison of human and animal /sup 238/Pu excretion data supported the observation that the excretion data were similar between the two species and that the animal excretion models can be applied to predict the human /sup 238/Pu excretion following inhalation exposure to high-fired oxides of /sup 238/Pu

  17. Aerosol Fragmentation Driven by Coupling of Acid-Base and Free-Radical Chemistry in the Heterogeneous Oxidation of Aqueous Citric Acid by OH Radicals.

    Science.gov (United States)

    Liu, Matthew J; Wiegel, Aaron A; Wilson, Kevin R; Houle, Frances A

    2017-08-10

    A key uncertainty in the heterogeneous oxidation of carboxylic acids by hydroxyl radicals (OH) in aqueous-phase aerosol is how the free-radical reaction pathways might be altered by acid-base chemistry. In particular, if acid-base reactions occur concurrently with acyloxy radical formation and unimolecular decomposition of alkoxy radicals, there is a possibility that differences in reaction pathways impact the partitioning of organic carbon between the gas and aqueous phases. To examine these questions, a kinetic model is developed for the OH-initiated oxidation of citric acid aerosol at high relative humidity. The reaction scheme, containing both free-radical and acid-base elementary reaction steps with physically validated rate coefficients, accurately predicts the experimentally observed molecular composition, particle size, and average elemental composition of the aerosol upon oxidation. The difference between the two reaction channels centers on the reactivity of carboxylic acid groups. Free-radical reactions mainly add functional groups to the carbon skeleton of neutral citric acid, because carboxylic acid moieties deactivate the unimolecular fragmentation of alkoxy radicals. In contrast, the conjugate carboxylate groups originating from acid-base equilibria activate both acyloxy radical formation and carbon-carbon bond scission of alkoxy radicals, leading to the formation of low molecular weight, highly oxidized products such as oxalic and mesoxalic acid. Subsequent hydration of carbonyl groups in the oxidized products increases the aerosol hygroscopicity and accelerates the substantial water uptake and volume growth that accompany oxidation. These results frame the oxidative lifecycle of atmospheric aerosol: it is governed by feedbacks between reactions that first increase the particle oxidation state, then eventually promote water uptake and acid-base chemistry. When coupled to free-radical reactions, acid-base channels lead to formation of low molecular

  18. Quantitative characterization of colloidal assembly of graphene oxide-silver nanoparticle hybrids using aerosol differential mobility-coupled mass analyses.

    Science.gov (United States)

    Nguyen, Thai Phuong; Chang, Wei-Chang; Lai, Yen-Chih; Hsiao, Ta-Chih; Tsai, De-Hao

    2017-10-01

    In this work, we develop an aerosol-based, time-resolved ion mobility-coupled mass characterization method to investigate colloidal assembly of graphene oxide (GO)-silver nanoparticle (AgNP) hybrid nanostructure on a quantitative basis. Transmission electron microscopy (TEM) and zeta potential (ZP) analysis were used to provide visual information and elemental-based particle size distributions, respectively. Results clearly show a successful controlled assembly of GO-AgNP by electrostatic-directed heterogeneous aggregation between GO and bovine serum albumin (BSA)-functionalized AgNP under an acidic environment. Additionally, physical size, mass, and conformation (i.e., number of AgNP per nanohybrid) of GO-AgNP were shown to be proportional to the number concentration ratio of AgNP to GO (R) and the selected electrical mobility diameter. An analysis of colloidal stability of GO-AgNP indicates that the stability increased with its absolute ZP, which was dependent on R and environmental pH. The work presented here provides a proof of concept for systematically synthesizing hybrid colloidal nanomaterials through the tuning of surface chemistry in aqueous phase with the ability in quantitative characterization. Graphical Abstract Colloidal assembly of graphene oxide-silver nanoparticle hybrids characterized by aerosol differential mobility-coupled mass analyses.

  19. Calibration of aerosol radiometers. Special aerosol sources

    International Nuclear Information System (INIS)

    Belkina, S.K.; Zalmanzon, Yu.E.; Kuznetsov, Yu.V.; Fertman, D.E.

    1988-01-01

    Problems of calibration of artificial aerosol radiometry and information-measurement systems of radiometer radiation control, in particular, are considered. Special aerosol source is suggested, which permits to perform certification and testing of aerosol channels of the systems in situ without the dismantling

  20. Synergistic reaction between SO2 and NO2 on mineral oxides: a potential formation pathway of sulfate aerosol.

    Science.gov (United States)

    Liu, Chang; Ma, Qingxin; Liu, Yongchun; Ma, Jinzhu; He, Hong

    2012-02-07

    Sulfate is one of the most important aerosols in the atmosphere. A new sulfate formation pathway via synergistic reactions between SO(2) and NO(2) on mineral oxides was proposed. The heterogeneous reactions of SO(2) and NO(2) on CaO, α-Fe(2)O(3), ZnO, MgO, α-Al(2)O(3), TiO(2), and SiO(2) were investigated by in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (in situ DRIFTS) at ambient temperature. Formation of sulfate from adsorbed SO(2) was promoted by the coexisting NO(2), while surface N(2)O(4) was observed as the crucial oxidant for the oxidation of surface sulfite. This process was significantly promoted by the presence of O(2). The synergistic effect between SO(2) and NO(2) was not observed on other mineral particles (such as CaCO(3) and CaSO(4)) probably due to the lack of the surface reactive oxygen sites. The synergistic reaction between SO(2) and NO(2) on mineral oxides resulted in the formation of internal mixtures of sulfate, nitrate, and mineral oxides. The change of mixture state will affect the physicochemical properties of atmospheric particles and therefore further influence their environmental and climate effects.

  1. Relating cloud condensation nuclei activity and oxidation level of alpha-pinene secondary organic aerosols

    DEFF Research Database (Denmark)

    Foverskov, Mia Frosch Mogensbæk; Bilde, M.; DeCarlo, P. F.

    2011-01-01

    During a series of smog chamber experiments, the effects of chemical and photochemical aging on the ability of organic aerosols generated from ozonolysis of alpha-pinene to act as cloud condensation nuclei (CCN) were investigated. In particular, the study focused on the relation between oxygenation...

  2. Advanced Oxidation: Oxalate Decomposition Testing With Ozone

    International Nuclear Information System (INIS)

    Ketusky, E.; Subramanian, K.

    2012-01-01

    At the Savannah River Site (SRS), oxalic acid is currently considered the preferred agent for chemically cleaning the large underground Liquid Radioactive Waste Tanks. It is applied only in the final stages of emptying a tank when generally less than 5,000 kg of waste solids remain, and slurrying based removal methods are no-longer effective. The use of oxalic acid is preferred because of its combined dissolution and chelating properties, as well as the fact that corrosion to the carbon steel tank walls can be controlled. Although oxalic acid is the preferred agent, there are significant potential downstream impacts. Impacts include: (1) Degraded evaporator operation; (2) Resultant oxalate precipitates taking away critically needed operating volume; and (3) Eventual creation of significant volumes of additional feed to salt processing. As an alternative to dealing with the downstream impacts, oxalate decomposition using variations of ozone based Advanced Oxidation Process (AOP) were investigated. In general AOPs use ozone or peroxide and a catalyst to create hydroxyl radicals. Hydroxyl radicals have among the highest oxidation potentials, and are commonly used to decompose organics. Although oxalate is considered among the most difficult organic to decompose, the ability of hydroxyl radicals to decompose oxalate is considered to be well demonstrated. In addition, as AOPs are considered to be 'green' their use enables any net chemical additions to the waste to be minimized. In order to test the ability to decompose the oxalate and determine the decomposition rates, a test rig was designed, where 10 vol% ozone would be educted into a spent oxalic acid decomposition loop, with the loop maintained at 70 C and recirculated at 40L/min. Each of the spent oxalic acid streams would be created from three oxalic acid strikes of an F-area simulant (i.e., Purex = high Fe/Al concentration) and H-area simulant (i.e., H area modified Purex = high Al/Fe concentration) after nearing

  3. ADVANCED OXIDATION: OXALATE DECOMPOSITION TESTING WITH OZONE

    Energy Technology Data Exchange (ETDEWEB)

    Ketusky, E.; Subramanian, K.

    2012-02-29

    At the Savannah River Site (SRS), oxalic acid is currently considered the preferred agent for chemically cleaning the large underground Liquid Radioactive Waste Tanks. It is applied only in the final stages of emptying a tank when generally less than 5,000 kg of waste solids remain, and slurrying based removal methods are no-longer effective. The use of oxalic acid is preferred because of its combined dissolution and chelating properties, as well as the fact that corrosion to the carbon steel tank walls can be controlled. Although oxalic acid is the preferred agent, there are significant potential downstream impacts. Impacts include: (1) Degraded evaporator operation; (2) Resultant oxalate precipitates taking away critically needed operating volume; and (3) Eventual creation of significant volumes of additional feed to salt processing. As an alternative to dealing with the downstream impacts, oxalate decomposition using variations of ozone based Advanced Oxidation Process (AOP) were investigated. In general AOPs use ozone or peroxide and a catalyst to create hydroxyl radicals. Hydroxyl radicals have among the highest oxidation potentials, and are commonly used to decompose organics. Although oxalate is considered among the most difficult organic to decompose, the ability of hydroxyl radicals to decompose oxalate is considered to be well demonstrated. In addition, as AOPs are considered to be 'green' their use enables any net chemical additions to the waste to be minimized. In order to test the ability to decompose the oxalate and determine the decomposition rates, a test rig was designed, where 10 vol% ozone would be educted into a spent oxalic acid decomposition loop, with the loop maintained at 70 C and recirculated at 40L/min. Each of the spent oxalic acid streams would be created from three oxalic acid strikes of an F-area simulant (i.e., Purex = high Fe/Al concentration) and H-area simulant (i.e., H area modified Purex = high Al/Fe concentration

  4. Transport of breeder reactor-fire-generated sodium oxide aerosols for building-wake-dominated meteorology

    Energy Technology Data Exchange (ETDEWEB)

    Fields, D.E.; Cooper, A.C.; Miller, C.W.

    1987-02-01

    This report describes the methodology used and results obtained in efforts to estimate the sodium aerosol concentrations at air intake ports of a liquid-metal cooled, fast-breeder nuclear reactor. An earlier version of this methodology has been previously discussed (Fields and Miller, 1985). A range of wind speeds from 2 to 10 m/s is assumed, and an effort is made to include building wake effects which, in many cases, dominate the dispersal of aerosols near buildings. For relatively small release rates, on the order of 1 to 10 kg/s, the plume rise is small and estimates of aerosol concentrations are derived using the methodology of Wilson and Britter (1982), which describes releases from surface vents. For release rates on the order of 100 kg/s much higher release velocities are expected, and plume rise is considered. An effective increase in release height is computed using the Split-H methodology with a parameterization suggested by Ramsdell (1983), and the release source strength is transformed to rooftop level. Evaluation of the acute release aerosol concentration is then based on the methodology for releases from a surface release of this transformed source strength. For a horizontal release, a methodology is developed to chart the plume path as a function of release and site meteorology parameters. Results described herein must be regarded as maximum aerosol concentrations, based on models derived from generic wind tunnel studies. More accurate and site-specific results may be obtained through wind tunnel simulations and through simulating emissions from release points other than those assumed here.

  5. Finish-Kazakhstan cooperation on an aerosols sampling - testing of a new methods for nuclear monitoring improvement

    International Nuclear Information System (INIS)

    Tarvajnen, M.; Akhmetov, M.A.; Ptitskaya, L.D.; Osintsev, A.Yu.; Zhantikin, T.M.; Eligbaeva, G.

    2001-01-01

    The aerosols sampling is the powerful method of air radioactivity monitoring both the natural and artificial origin. Up to the today the IAEA does not engage of aerosols sampling study. To study of possibility of this method examination for radiation monitoring - the state authorities of Finland and the Republic of Kazakhstan - Department of Radiation and Nuclear Safety (Stuck) and Kazakhstan Atomic Energy Committee - jointly carried out the field tests in Kazakhstan. The test was began in the Kurchatov in April 2000 - at the desire of IAEA working team on Iraq - close to former Semipalatinsk test site and was ended in Astana in August of 2001. The main aim of the field test was study of possibility and appropriateness of concept and technology of aerosols sampling developed for the complete condition of environment. In the paper the role of participating sides in the field test and main results and conclusions are discussed as well. The gained experience will allow developing the method aerosols sampling for IAEA international safeguard measures strengthening application

  6. Chemical and physical transformations of organic aerosol from the photo-oxidation of open biomass burning emissions in an environmental chamber

    Science.gov (United States)

    C. J. Hennigan; M. A. Miracolo; G. J. Engelhart; A. A. May; A. A. Presto; T. Lee; A. P. Sullivan; G. R. McMeeking; H. Coe; C. E. Wold; W.-M. Hao; J. B. Gilman; W. C. Kuster; J. de Gouw; B. A. Schichtel; J. L. Collett; S. M. Kreidenweis; A. L. Robinson

    2011-01-01

    Smog chamber experiments were conducted to investigate the chemical and physical transformations of organic aerosol (OA) during photo-oxidation of open biomass burning emissions. The experiments were carried out at the US Forest Service Fire Science Laboratory as part of the third Fire Lab at Missoula Experiment (FLAME III). We investigated emissions from 12 different...

  7. VUV photoionization aerosol mass spectrometric study on the iodine oxide particles formed from O3-initiated photooxidation of diiodomethane (CH2I2)

    Czech Academy of Sciences Publication Activity Database

    Wei, N.; Hu, Ch.; Zhou, S.; Ma, Q.; Mikuška, Pavel; Večeřa, Zbyněk; Gai, Y.; Lin, X.; Gu, X.; Zhao, W.; Fang, B.; Zhang, W.; Chen, J.; Liu, F.; Shan, X.; Sheng, L.

    2017-01-01

    Roč. 7, č. 89 (2017), s. 56779-56787 ISSN 2046-2069 Institutional support: RVO:68081715 Keywords : iodine oxide particles * photooxidation * aerosol mass spectrometer Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 3.108, year: 2016

  8. Results of aerosol code comparisons with releases from ACE MCCI tests

    International Nuclear Information System (INIS)

    Fink, J.K.; Corradini, M.; Hidaka, A.; Hontanon, E.; Mignanelli, M.A.; Schroedl, E.; Strizhov, V.

    1992-01-01

    Results of aerosol release calculations by six groups from six countries are compared with the releases from ACE MCCI Test L6. The codes used for these calculations included: SOLGASMIX-PV, SOLGASMIX Reactor 1986, CORCON.UW, VANESA 1.01, and CORCON mod2.04/VANESA 1.01. Calculations were performed with the standard VANESA 1.01 code and with modifications to the VANESA code such as the inclusion of various zirconium-silica chemical reactions. Comparisons of results from these calculations were made with Test L6 release fractions for U, Zr, Si, the fission-product elements Te, Ba, Sr, Ce, La, Mo and control materials Ag, In, and Ru. Reasonable agreement was obtained between calculations and Test L6 results for the volatile elements Ag, In and Te. Calculated releases of the low volatility fission products ranged from within an order of magnitude to five orders of magnitude of Test L6 values. Releases were over and underestimated by calculations. Poorest agreements were obtained for Mo and Si

  9. Monoterpene oxidation in an oxidative flow reactor: SOA yields and the relationship between bulk gas-phase properties and organic aerosol growth

    Science.gov (United States)

    Friedman, B.; Link, M.; Farmer, D.

    2016-12-01

    We use an oxidative flow reactor (OFR) to determine the secondary organic aerosol (SOA) yields of five monoterpenes (alpha-pinene, beta-pinene, limonene, sabinene, and terpinolene) at a range of OH exposures. These OH exposures correspond to aging timescales of a few hours to seven days. We further determine how SOA yields of beta-pinene and alpha-pinene vary as a function of seed particle type (organic vs. inorganic) and seed particle mass concentration. We hypothesize that the monoterpene structure largely accounts for the observed variance in SOA yields for the different monoterpenes. We also use high-resolution time-of-flight chemical ionization mass spectrometry to calculate the bulk gas-phase properties (O:C and H:C) of the monoterpene oxidation systems as a function of oxidant concentrations. Bulk gas-phase properties can be compared to the SOA yields to assess the capability of the precursor gas-phase species to inform the SOA yields of each monoterpene oxidation system. We find that the extent of oxygenated precursor gas-phase species corresponds to SOA yield.

  10. Inhalation toxicology of industrial plutonium and uranium oxide aerosols II. Deposition, retention and dosimetry

    International Nuclear Information System (INIS)

    Stanley, J.A.; Eidson, A.F.; Mewhinney, J.A.; Mo, T.

    1978-01-01

    A series of studies has been initiated in which powdered fuel materials obtained at industrial sites have been aerosolized in the dry state for the inhalation exposure of Fischer-344 rats, Beagle dogs and Cynomolgus monkeys to evaluate the potential biological hazard of such accidents. The materials chosen for study were 750 deg. C heat-treated mixed PuO 2 and UO 2 obtained from a ball milling process and 1750 deg. C heat-treated (U,Pu)O 1.97 powder obtained from the centerless grinding of fuel pellets. Care was taken to insure that the regenerated aerosols used in animal inhalation exposures had similar particle size and size distribution characteristics to those measured during glove box sampling at the industrial plant. The deposition, retention, distribution and excretion of these materials are being studied, using serial sacrifice of animals at times from 4 hours to several years after inhalation exposure. Periodic excreta samples are collected on all animals. Biological samples are analyzed to yield data on Pu, Am and U content. Data from animals sacrificed up to one year will be presented. The retention of 239 Pu and 241 Am in the lung and their subsequent clearance and translocation to other tissues such as liver, skeleton and tracheobronchial lymph nodes will be discussed in relation to the influence of species and of the physical chemical properties of the exposure aerosol. (author)

  11. Supercritical water oxidation data acquisition testing. Final report, Volume I

    International Nuclear Information System (INIS)

    1996-11-01

    This report discusses the phase one testing of a data acquisition system for a supercritical water waste oxidation system. The system is designed to destroy a wide range of organic materials in mixed wastes. The design and testing of the MODAR Oxidizer is discussed. An analysis of the optimized runs is included

  12. Extreme testing of undiluted e-cigarette aerosol in vitro using an Ames air-agar-interface technique.

    Science.gov (United States)

    Thorne, D; Hollings, M; Seymour, A; Adamson, J; Dalrymple, A; Ballantyne, M; Gaca, M

    2018-04-01

    There is a growing consensus that e-cigarettes hold the potential for reducing the harm associated with cigarette smoking. Recently published studies have reported in vitro testing of e-cigarettes, demonstrating reduced toxicological and biological effects. Few studies however have reported the use of e-cigarettes under extreme testing conditions. To assess the full mutagenic potential of a commercially available electronic-cigarette (Vype ePen), this study investigated the delivery of aerosol under extreme conditions, using a scaled-down 35 mm plate Ames bacterial reverse mutagenicity assay. S. typhimurium strains TA98, TA100, TA97, TA104 and E. coli WP2 uvrA pKM101 with or without metabolic activation (S9), were employed. Using a modified Vitrocell VC 10 exposure system 0, 180, 360, 540, 720 or 900 puffs of undiluted e-cigarette aerosol was generated and delivered to bacterial cultures aligned to reported human consumption data. The results demonstrate that no mutagenic activity was observed in any strain under any test condition even when exposed to 900 puffs of undiluted e-cigarette aerosols +/- S9. Positive control responses were observed in all strains +/- S9. Nicotine assessments demonstrated an increased and consistent aerosol delivery, with calculated maximum doses of ∼1 mg/mL delivery of nicotine. These data demonstrate the validity of this unique testing approach and adds further information to the growing weight of evidence that e-cigarettes offer substantially reduced exposure when compared to conventional cigarette smoke. For future in vitro assessments of next generation tobacco and nicotine products, the generation, delivery and testing of undiluted aerosols can now be considered. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  13. Simulation test of aerosol generation from vessels in the pre-treatment system of fuel reprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Fujine, Sachio; Kitamura, Koichiro; Kihara, Takehiro [Japan Atomic Energy Research Institute (JAERI), Ibaraki-ken (Japan)

    1997-08-01

    Aerosol concentration and droplet size are measured in off-gas of vessel under various conditions by changing off-gas flow rate, stirring air flow rate, salts concentration and temperature of nitrate solution. Aerosols are also measured under evaporation and air-lift operation. 4 refs., 6 figs.

  14. Experimental determination of the partitioning coefficient and volatility of important BVOC oxidation products using the Aerosol Collection Module (ACM) coupled to a PTR-ToF-MS

    Science.gov (United States)

    Gkatzelis, G.; Hohaus, T.; Tillmann, R.; Schmitt, S. H.; Yu, Z.; Schlag, P.; Wegener, R.; Kaminski, M.; Kiendler-Scharr, A.

    2015-12-01

    Atmospheric aerosol can alter the Earth's radiative budget and global climate but can also affect human health. A dominant contributor to the submicrometer particulate matter (PM) is organic aerosol (OA). OA can be either directly emitted through e.g. combustion processes (primary OA) or formed through the oxidation of organic gases (secondary organic aerosol, SOA). A detailed understanding of SOA formation is of importance as it constitutes a major contribution to the total OA. The partitioning between the gas and particle phase as well as the volatility of individual components of SOA is yet poorly understood adding uncertainties and thus complicating climate modelling. In this work, a new experimental methodology was used for compound-specific analysis of organic aerosol. The Aerosol Collection Module (ACM) is a newly developed instrument that deploys an aerodynamic lens to separate the gas and particle phase of an aerosol. The particle phase is directed to a cooled sampling surface. After collection particles are thermally desorbed and transferred to a detector for further analysis. In the present work, the ACM was coupled to a Proton Transfer Reaction-Time of Flight-Mass Spectrometer (PTR-ToF-MS) to detect and quantify organic compounds partitioning between the gas and particle phase. This experimental approach was used in a set of experiments at the atmosphere simulation chamber SAPHIR to investigate SOA formation. Ozone oxidation with subsequent photochemical aging of β-pinene, limonene and real plant emissions from Pinus sylvestris (Scots pine) were studied. Simultaneous measurement of the gas and particle phase using the ACM-PTR-ToF-MS allows to report partitioning coefficients of important BVOC oxidation products. Additionally, volatility trends and changes of the SOA with photochemical aging are investigated and compared for all systems studied.

  15. X-ray fluorimetry in tests of the aerosol substances. [In the atmosphere]. Rentgenowska analiza fluorescencyjna w badaniach skladu pierwiastkowego aerozoli w atmosferze

    Energy Technology Data Exchange (ETDEWEB)

    Walentek, A.; Cudny, W.; Marzec, J.; Pawlowski, Z.; Zaremba, K. (Politechnika Warszawska, Warsaw (Poland). Inst. Radioelektroniki)

    1992-01-01

    Test results of aerosol samples from atmospheric air collected from membrane drains were presented. The ANFLU-2 analyzer constructed at the Warsaw Technical University were used for testing. (author). 3 figs, 1 tab.

  16. Research on aerosol formation, aerosol behaviour, aerosol filtration, aerosol measurement techniques and sodium fires at the Laboratory for Aerosol Physics and Filter Technology at the Nuclear Research Center Karlsruhe

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, S; Schikarski, W; Schoeck, W [Gesellschaft fuer Kernforschung mbH, Karlsruhe (Germany)

    1977-01-01

    The behaviour of aerosols in LMFBR plant systems is of great importance for a number of problems, both normal operational and accident kind. This paper covers the following: aerosol modelling for LMFBR containment systems; aerosol size spectrometry by laser light scattering; experimental facilities and experimental results concerned with aerosol release under accident conditions; filtration of sodium oxide aerosols by multilayer sand bed filters.

  17. Research on aerosol formation, aerosol behaviour, aerosol filtration, aerosol measurement techniques and sodium fires at the Laboratory for Aerosol Physics and Filter Technology at the Nuclear Research Center Karlsruhe

    International Nuclear Information System (INIS)

    Jordan, S.; Schikarski, W.; Schoeck, W.

    1977-01-01

    The behaviour of aerosols in LMFBR plant systems is of great importance for a number of problems, both normal operational and accident kind. This paper covers the following: aerosol modelling for LMFBR containment systems; aerosol size spectrometry by laser light scattering; experimental facilities and experimental results concerned with aerosol release under accident conditions; filtration of sodium oxide aerosols by multilayer sand bed filters

  18. Development and Application of an Oxidation Flow Reactor to Study Secondary Organic Aerosol Formation from Ambient Air

    Science.gov (United States)

    Palm, Brett Brian

    Secondary organic aerosols (SOA) in the atmosphere play an important role in air quality, human health, and climate. However, the sources, formation pathways, and fate of SOA are poorly constrained. In this dissertation, I present development and application of the oxidation flow reactor (OFR) technique for studying SOA formation from OH, O3, and NO3 oxidation of ambient air. With a several-minute residence time and a portable design with no inlet, OFRs are particularly well-suited for this purpose. I first introduce the OFR concept, and discuss several advances I have made in performing and interpreting OFR experiments. This includes estimating oxidant exposures, modeling the fate of low-volatility gases in the OFR (wall loss, condensation, and oxidation), and comparing SOA yields of single precursors in the OFR with yields measured in environmental chambers. When these experimental details are carefully considered, SOA formation in an OFR can be more reliably compared with ambient SOA formation processes. I then present an overview of what OFR measurements have taught us about SOA formation in the atmosphere. I provide a comparison of SOA formation from OH, O3, and NO3 oxidation of ambient air in a wide variety of environments, from rural forests to urban air. In a rural forest, the SOA formation correlated with biogenic precursors (e.g., monoterpenes). In urban air, it correlated instead with reactive anthropogenic tracers (e.g., trimethylbenzene). In mixed-source regions, the SOA formation did not correlate well with any single precursor, but could be predicted by multilinear regression from several precursors. Despite these correlations, the concentrations of speciated ambient VOCs could only explain approximately 10-50% of the total SOA formed from OH oxidation. In contrast, ambient VOCs could explain all of the SOA formation observed from O3 and NO3 oxidation. Evidence suggests that lower-volatility gases (semivolatile and intermediate-volatility organic

  19. Simulating secondary organic aerosol in a regional air quality model using the statistical oxidation model - Part 1: Assessing the influence of constrained multi-generational ageing

    Science.gov (United States)

    Jathar, S. H.; Cappa, C. D.; Wexler, A. S.; Seinfeld, J. H.; Kleeman, M. J.

    2016-02-01

    Multi-generational oxidation of volatile organic compound (VOC) oxidation products can significantly alter the mass, chemical composition and properties of secondary organic aerosol (SOA) compared to calculations that consider only the first few generations of oxidation reactions. However, the most commonly used state-of-the-science schemes in 3-D regional or global models that account for multi-generational oxidation (1) consider only functionalization reactions but do not consider fragmentation reactions, (2) have not been constrained to experimental data and (3) are added on top of existing parameterizations. The incomplete description of multi-generational oxidation in these models has the potential to bias source apportionment and control calculations for SOA. In this work, we used the statistical oxidation model (SOM) of Cappa and Wilson (2012), constrained by experimental laboratory chamber data, to evaluate the regional implications of multi-generational oxidation considering both functionalization and fragmentation reactions. SOM was implemented into the regional University of California at Davis / California Institute of Technology (UCD/CIT) air quality model and applied to air quality episodes in California and the eastern USA. The mass, composition and properties of SOA predicted using SOM were compared to SOA predictions generated by a traditional two-product model to fully investigate the impact of explicit and self-consistent accounting of multi-generational oxidation.Results show that SOA mass concentrations predicted by the UCD/CIT-SOM model are very similar to those predicted by a two-product model when both models use parameters that are derived from the same chamber data. Since the two-product model does not explicitly resolve multi-generational oxidation reactions, this finding suggests that the chamber data used to parameterize the models captures the majority of the SOA mass formation from multi-generational oxidation under the conditions

  20. 78 FR 6400 - Results of FAA Nitrous Oxide BLEVE Characterization Testing

    Science.gov (United States)

    2013-01-30

    ... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Results of FAA Nitrous Oxide BLEVE Characterization Testing AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of public... FAA sponsored testing of nitrous oxide (N 2 O) characteristics. Nitrous oxide is an important oxidizer...

  1. New X-ray testing methods of aerosol products for industrial radiography

    Energy Technology Data Exchange (ETDEWEB)

    Bozydar Knyziak, Adrian, E-mail: a.knyziak@gum.gov.pl; Rzodkiewicz, Witold, E-mail: w.rzodkiewicz@gum.gov.pl; Kaczorowska, Ewa, E-mail: e.kaczorowska@gum.gov.pl; Derlacinski, Michal, E-mail: m.derlacinski@gum.gov.pl

    2017-02-01

    An amount of product in e.g. an aerosol canister is not difficult to estimate by weighing a filled can and subtracting the tare of packaging. In this way, we can obtain the net weight of the ingredients present in the can. Although, this does not indicate the volumetric content. Therefore, in the paper, the fundamental (the weight method and given by FEICA) and new methods (given by authors) related to the determination of the volumetric content of canister filled with aeorosol products are presented. The new methods are based on direct digital radiography (DR) using X-ray radiation. For the needs of new methods, the X-ray CCD-DR imaging system was built and developed in our Laboratory in Department of Radiation and Vibration at the Central Office of Measures. For comparison purposes, with regard to the volumetric content, a lot of metal cans of capacities 140, 185, 450, 700 ml were inspected. In future, computed tomography (CT) for industrial radiography in our laboratory will be used. Currently, an algorithm for CT is being tested. It will give us possibility for very precise measurements to determine volumetric content of examined canisters.

  2. Photodegradation of secondary organic aerosol generated from limonene oxidation by ozone studied with chemical ionization mass spectrometry

    Directory of Open Access Journals (Sweden)

    X. Pan

    2009-06-01

    Full Text Available Photodegradation of secondary organic aerosol (SOA prepared by ozone-initiated oxidation of D-limonene is studied with an action spectroscopy approach, which relies on detection of volatile photoproducts with chemical ionization mass-spectrometry as a function of the UV irradiation wavelength. Efficient photodegradation is observed for a broad range of ozone (0.1–300 ppm and D-limonene (0.02–3 ppm concentrations used in the preparation of SOA. The observed photoproducts are dominated by oxygenated C1-C3 compounds such as methanol, formic acid, acetaldehyde, acetic acid, and acetone. The irradiation wavelength dependence of the combined yield of the photoproducts closely tracks the absorption spectrum of the SOA material suggesting that photodegradation is not limited to the UV wavelengths. Kinetic simulations suggest that RO2+HO2/RO2 reactions represent the dominant route to photochemically active carbonyl and peroxide species in the limonene SOA prepared in these experiments. Similar photodegradation processes are likely to occur in realistic SOA produced by OH- or O3-initiated oxidation of biogenic volatile organic compounds in clean air.

  3. Oxidative potential of ambient fine aerosol over a semi-urban site in the Indo-Gangetic Plain

    Science.gov (United States)

    Patel, Anil; Rastogi, Neeraj

    2018-02-01

    Indo-Gangetic Plain (IGP) receives emissions from variety of pollutant sources such as post-harvest crop residue burning, vehicles, industries, power plants, and bio-fuel burning. Several studies have documented physical, chemical and optical properties of aerosol over the IGP; however, their oxidative potential (OP) has not yet documented. Present study reports the OP (measured through dithiothreitol (DTT) assay) of soluble particulate matter smaller than 2.5 μm aerodynamic diameter (PM2.5) over Patiala (30.3°N, 76.4°E, 249 m amsl), a semi-urban site located in the IGP, during winter 2014. Volume-normalized OP (range: 1.3-7.2 nmol DTT min-1 m-3, average: 3.8 ± 1.4, 1σ) is found to be ∼3 to 20 times higher, and mass-normalized OP (range: 13-50 pmol DTT min-1 μg-1, average: 27 ± 8, 1σ) is found to be similar or higher than those documented in literature. Further, observed OP is found to depend more on PM2.5 composition rather than mass concentration. Mass fractions of organic carbon (OC), elemental carbon (EC) and water-soluble organic carbon (WSOC) correlate positively whereas that of secondary inorganic aerosol (SIA, sum of the concentrations of SO42-, NO3- and NH4+) correlate negatively with OP μg-1 at considerable significance level (p < 0.05). Negative correlation of SIA with OP μg-1 has been assessed in laboratory experiment and attributed to their DTT inactive nature. It is suggested to use WSOC/SIA ratio as a measure of DTT activity of secondary particles over the study region. Further, biomass burning derived species are observed to be more DTT active than those derived from fossil fuel burning. It was also observed that the slope of OP μg-1 and WSOC/SIA ratio linear relationship enhances significantly in samples collected during days following foggy nights in comparison to that in samples collected during non-foggy period, which may be due to the production of redox-active species by fog processing. Such studies have implications in assessing

  4. The Optical Properties of Limonene Secondary Organic Aerosols: The Role of NO3, OH, and O3 in the Oxidation Processes

    Science.gov (United States)

    Peng, Chao; Wang, Weigang; Li, Kun; Li, Junling; Zhou, Li; Wang, Lingshu; Ge, Maofa

    2018-03-01

    Limonene, a typical proxy of monoterpenes emitted from biogenic sources, plays an important role in secondary organic aerosol (SOA) formation. However, the optical properties of SOA generated from limonene under various oxidation pathways remain poorly understood. In this study, we investigate the refractive index (RI) of limonene SOA produced from four oxidation conditions with cavity ring-down spectrometer (CRDS) and photoacoustic extinctiometer operated at 532 and 375 nm. Our results show that there is a significant difference in RI values of SOA produced from NO3 oxidation compared to other oxidation pathways. The mean values of RI of SOA produced from NO3 oxidation, NOx oxidation, OH oxidation with NOx-free, and O3 oxidation experiments are 1.578, 1.469, 1.495, and 1.494 at 532 nm; and 1.591, 1.527, 1.513, and 1.537 at 375 nm, respectively, while no detectable absorption is found in all oxidation conditions. We attribute the high RI values of SOA by NO3 oxidation to two factors: a large proportion of organic nitrates and high-molecular-weight dimers/oligomers in the SOA. Our study results indicate that the nighttime chemistry may significantly influence the optical properties of limonene oxidation products. The RI values of limonene SOA generated under various oxidation conditions at different wavelengths retrieved in our laboratory experiments could help improve the model predictions for evaluating the effect of biogenic SOA on the global radiative forcing as well as climate change.

  5. Development and Testing of the New Surface LER Climatology for OMI UV Aerosol Retrievals

    Science.gov (United States)

    Gupta, Pawan; Torres, Omar; Jethva, Hiren; Ahn, Changwoo

    2014-01-01

    Ozone Monitoring Instrument (OMI) onboard Aura satellite retrieved aerosols properties using UV part of solar spectrum. The OMI near UV aerosol algorithm (OMAERUV) is a global inversion scheme which retrieves aerosol properties both over ocean and land. The current version of the algorithm makes use of TOMS derived Lambertian Equivalent Reflectance (LER) climatology. A new monthly climatology of surface LER at 354 and 388 nm have been developed. This will replace TOMS LER (380 nm and 354nm) climatology in OMI near UV aerosol retrieval algorithm. The main objectives of this study is to produce high resolution (quarter degree) surface LER sets as compared to existing one degree TOMS surface LERs, to product instrument and wavelength consistent surface climatology. Nine years of OMI observations have been used to derive monthly climatology of surface LER. MODIS derived aerosol optical depth (AOD) have been used to make aerosol corrections on OMI wavelengths. MODIS derived BRDF adjusted reflectance product has been also used to capture seasonal changes in the surface characteristics. Finally spatial and temporal averaging techniques have been used to fill the gaps around the globes, especially in the regions with consistent cloud cover such as Amazon. After implementation of new surface data in the research version of algorithm, comparisons of AOD and single scattering albedo (SSA) have been performed over global AERONET sites for year 2007. Preliminary results shows improvements in AOD retrievals globally but more significance improvement were observed over desert and bright locations. We will present methodology of deriving surface data sets and will discuss the observed changes in retrieved aerosol properties with respect to reference AERONET measurements.

  6. Biogenic oxidized organic functional groups in aerosol particles from a mountain forest site and their similarities to laboratory chamber products

    Directory of Open Access Journals (Sweden)

    R. E. Schwartz

    2010-06-01

    Full Text Available Submicron particles collected at Whistler, British Columbia, at 1020 m a.s.l. during May and June 2008 on Teflon filters were analyzed by Fourier transform infrared (FTIR and X-ray fluorescence (XRF techniques for organic functional groups (OFG and elemental composition. Organic mass (OM concentrations ranged from less than 0.5 to 3.1 μg m−3, with a project mean and standard deviation of 1.3±1.0 μg m−3 and 0.21±0.16 μg m−3 for OM and sulfate, respectively. On average, organic hydroxyl, alkane, and carboxylic acid groups represented 34%, 33%, and 23% of OM, respectively. Ketone, amine and organosulfate groups constituted 6%, 5%, and <1% of the average organic aerosol composition, respectively. Measurements of volatile organic compounds (VOC, including isoprene and monoterpenes from biogenic VOC (BVOC emissions and their oxidation products (methyl-vinylketone / methacrolein, MVK/MACR, were made using co-located proton transfer reaction mass spectrometry (PTR-MS. We present chemically-specific evidence of OFG associated with BVOC emissions. Positive matrix factorization (PMF analysis attributed 65% of the campaign OM to biogenic sources, based on the correlations of one factor to monoterpenes and MVK/MACR. The remaining fraction was attributed to anthropogenic sources based on a correlation to sulfate. The functional group composition of the biogenic factor (consisting of 32% alkane, 25% carboxylic acid, 21% organic hydroxyl, 16% ketone, and 6% amine groups was similar to that of secondary organic aerosol (SOA reported from the oxidation of BVOCs in laboratory chamber studies, providing evidence that the magnitude and chemical composition of biogenic SOA simulated in the laboratory is similar to that found in actual atmospheric conditions. The biogenic factor OM is also correlated to dust elements, indicating that dust may act as a non-acidic SOA sink. This role is supported by the organic functional

  7. Contribution to the study of nuclear aerosol: looking for the dynamic form factor of the aerosol of primary particles of sodium oxide

    International Nuclear Information System (INIS)

    Barbe, M.

    1982-09-01

    The dynamical form factor describes the entrainment of any non spherical particle, of inhomogeneous density, in relation to the entrainment of a spherical particle with the same volume and some sedimentation speed. Experimental study of the form factor and particle size distribution of sodium peroxide primary aerosols [fr

  8. Interim results from UO2 fuel oxidation tests in air

    International Nuclear Information System (INIS)

    Campbell, T.K.; Gilbert, E.R.; Thornhill, C.K.; White, G.D.; Piepel, G.F.; Griffin, C.W.j.

    1987-08-01

    An experimental program is being conducted at Pacific Northwest Laboratory (PNL) to extend the characterization of spent fuel oxidation in air. To characterize oxidation behavior of irradiated UO 2 , fuel oxidation tests were performed on declad light-water reactor spent fuel and nonirradited UO 2 pellets in the temperature range of 135 to 250 0 C. These tests were designed to determine the important independent variables that might affect spent fuel oxidation behavior. The data from this program, when combined with the test results from other programs, will be used to develop recommended spent fuel dry-storage temperature limits in air. This report describes interim test results. The initial PNL investigations of nonirradiated and spent fuels identified the important testing variables as temperature, fuel burnup, radiolysis of the air, fuel microstructure, and moisture in the air. Based on these initial results, a more extensive statistically designed test matrix was developed to study the effects of temperature, burnup, and moisture on the oxidation behavior of spent fuel. Oxidation tests were initiated using both boiling-water reactor and pressurized-water reactor fuels from several different reactors with burnups from 8 to 34 GWd/MTU. A 10 5 R/h gamma field was applied to the test ovens to simulate dry storage cask conditions. Nonirradiated fuel was included as a control. This report describes experimental results from the initial tests on both the spent and nonirradiated fuels and results to date on the tests in a 10 5 R/h gamma field. 33 refs., 51 figs., 6 tabs

  9. Simulating secondary organic aerosol in a regional air quality model using the statistical oxidation model – Part 2: Assessing the influence of vapor wall losses

    OpenAIRE

    Cappa, Christopher D.; Jathar, Shantanu H.; Kleeman, Michael J.; Docherty, Kenneth S.; Jimenez, Jose L.; Seinfeld, John H.; Wexler, Anthony S.

    2016-01-01

    The influence of losses of organic vapors to chamber walls during secondary organic aerosol (SOA) formation experiments has recently been established. Here, the influence of such losses on simulated ambient SOA concentrations and properties is assessed in the UCD/CIT regional air quality model using the statistical oxidation model (SOM) for SOA. The SOM was fit to laboratory chamber data both with and without accounting for vapor wall losses following the approa...

  10. Formation and occurrence of dimer esters of pinene oxidation products in atmospheric aerosols

    DEFF Research Database (Denmark)

    Kristensen, Kasper; Enggrob, Kirsten L.; King, S. M.

    2013-01-01

    products cis-pinic and terpenylic acids, but similar to the second-generation oxidation products 3-methyl-1,2,3-butane tricarboxylic acid (MBTCA) and diaterpenylic acid acetate (DTAA). Dimer esters were observed within the first 30 min, indicating rapid production simultaneous to their structural...

  11. Nitrate radicals and biogenic volatile organic compounds: oxidation, mechanisms, and organic aerosol

    Science.gov (United States)

    Oxidation of biogenic volatile organic compounds (BVOC) by the nitrate radical (NO3) represents one of the important interactions between anthropogenic emissions related to combustion and natural emissions from the biosphere. This interaction has been recognized for more than 3 d...

  12. Assessing the impact of anthropogenic pollution on isoprene-derived secondary organic aerosol formation in PM2.5 collected from the Birmingham, Alabama, ground site during the 2013 Southern Oxidant and Aerosol Study

    Directory of Open Access Journals (Sweden)

    W. Rattanavaraha

    2016-04-01

    Full Text Available In the southeastern US, substantial emissions of isoprene from deciduous trees undergo atmospheric oxidation to form secondary organic aerosol (SOA that contributes to fine particulate matter (PM2.5. Laboratory studies have revealed that anthropogenic pollutants, such as sulfur dioxide (SO2, oxides of nitrogen (NOx, and aerosol acidity, can enhance SOA formation from the hydroxyl radical (OH-initiated oxidation of isoprene; however, the mechanisms by which specific pollutants enhance isoprene SOA in ambient PM2.5 remain unclear. As one aspect of an investigation to examine how anthropogenic pollutants influence isoprene-derived SOA formation, high-volume PM2.5 filter samples were collected at the Birmingham, Alabama (BHM, ground site during the 2013 Southern Oxidant and Aerosol Study (SOAS. Sample extracts were analyzed by gas chromatography–electron ionization-mass spectrometry (GC/EI-MS with prior trimethylsilylation and ultra performance liquid chromatography coupled to electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (UPLC/ESI-HR-QTOFMS to identify known isoprene SOA tracers. Tracers quantified using both surrogate and authentic standards were compared with collocated gas- and particle-phase data as well as meteorological data provided by the Southeastern Aerosol Research and Characterization (SEARCH network to assess the impact of anthropogenic pollution on isoprene-derived SOA formation. Results of this study reveal that isoprene-derived SOA tracers contribute a substantial mass fraction of organic matter (OM ( ∼  7 to  ∼  20 %. Isoprene-derived SOA tracers correlated with sulfate (SO42− (r2 = 0.34, n = 117 but not with NOx. Moderate correlations between methacrylic acid epoxide and hydroxymethyl-methyl-α-lactone (together abbreviated MAE/HMML-derived SOA tracers with nitrate radical production (P[NO3] (r2 = 0.57, n = 40 were observed during nighttime, suggesting a

  13. Molecular characterization of brown carbon (BrC) chromophores in secondary organic aerosol generated from photo-oxidation of toluene.

    Science.gov (United States)

    Lin, Peng; Liu, Jiumeng; Shilling, John E; Kathmann, Shawn M; Laskin, Julia; Laskin, Alexander

    2015-09-28

    Atmospheric brown carbon (BrC) is a significant contributor to light absorption and climate forcing. However, little is known about a fundamental relationship between the chemical composition of BrC and its optical properties. In this work, light-absorbing secondary organic aerosol (SOA) was generated in the PNNL chamber from toluene photo-oxidation in the presence of NOx (Tol-SOA). Molecular structures of BrC components were examined using nanospray desorption electrospray ionization (nano-DESI) and liquid chromatography (LC) combined with UV/Vis spectroscopy and electrospray ionization (ESI) high-resolution mass spectrometry (HRMS). The chemical composition of BrC chromophores and the light absorption properties of toluene SOA (Tol-SOA) depend strongly on the initial NOx concentration. Specifically, Tol-SOA generated under high-NOx conditions (defined here as initial NOx/toluene of 5/1) appears yellow and mass absorption coefficient of the bulk sample (MACbulk@365 nm = 0.78 m(2) g(-1)) is nearly 80 fold higher than that measured for the Tol-SOA sample generated under low-NOx conditions (NOx/toluene atmosphere.

  14. Characterization of secondary organic aerosol from photo-oxidation of gasoline exhaust and specific sources of major components.

    Science.gov (United States)

    Ma, Pengkun; Zhang, Peng; Shu, Jinian; Yang, Bo; Zhang, Haixu

    2018-01-01

    To further explore the composition and distribution of secondary organic aerosol (SOA) components from the photo-oxidation of light aromatic precursors (toluene, m-xylene, and 1,3,5-trimethylbenzene (1,3,5-TMB)) and idling gasoline exhaust, a vacuum ultraviolet photoionization mass spectrometer (VUV-PIMS) was employed. Peaks of the molecular ions of the SOA components with minimum molecular fragmentation were clearly observed from the mass spectra of SOA, through the application of soft ionization methods in VUV-PIMS. The experiments comparing the exhaust-SOA and light aromatic mixture-SOA showed that the observed distributions of almost all the predominant cluster ions in the exhaust-SOA were similar to that of the mixture-SOA. Based on the characterization experiments of SOA formed from individual light aromatic precursors, the SOA components with molecular weights of 98 and 110 amu observed in the exhaust-SOA resulted from the photo-oxidation of toluene and m-xylene; the components with a molecular weight of 124 amu were derived mainly from m-xylene; and the components with molecular weights of 100, 112, 128, 138, and 156 amu were mainly derived from 1,3,5-TMB. These results suggest that C 7 -C 9 light aromatic hydrocarbons are significant SOA precursors and that major SOA components originate from gasoline exhaust. Additionally, some new light aromatic hydrocarbon-SOA components were observed for the first time using VUV-PIMS. The corresponding reaction mechanisms were also proposed in this study to enrich the knowledge base of the formation mechanisms of light aromatic hydrocarbon-SOA compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Seasonal cycles of secondary organic aerosol tracers in rural Guangzhou, Southern China: The importance of atmospheric oxidants.

    Science.gov (United States)

    Yuan, Qi; Lai, Senchao; Song, Junwei; Ding, Xiang; Zheng, Lishan; Wang, Xinming; Zhao, Yan; Zheng, Junyu; Yue, Dingli; Zhong, Liuju; Niu, Xiaojun; Zhang, Yingyi

    2018-05-21

    Thirteen secondary organic aerosol (SOA) tracers of isoprene (SOA I ), monoterpenes (SOA M ), sesquiterpenes (SOA S ) and aromatics (SOA A ) in fine particulate matter (PM 2.5 ) were measured at a Pearl River Delta (PRD) regional site for one year. The characteristics including their seasonal cycles and the factors influencing their formation in this region were studied. The seasonal patterns of SOA I , SOA M and SOA S tracers were characterized over three enhancement periods in summer (I), autumn (II) and winter (III), while the elevations of SOA A tracer (i.e., 2,3-dihydroxy-4-oxopentanoic acid, DHOPA) were observed in Periods II and III. We found that SOA formed from different biogenic precursors could be driven by several factors during a one-year seasonal cycle. Isoprene emission controlled SOA I formation throughout the year, while monoterpene and sesquiterpene emissions facilitated SOA M and SOA S formation in summer rather than in other seasons. The influence of atmospheric oxidants (O x ) was found to be an important factor of the formation of SOA M tracers during the enhancement periods in autumn and winter. The formation of SOA S tracer was influenced by the precursor emissions in summer, atmospheric oxidation in autumn and probably also by biomass burning in both summer and winter. In this study, we could not see the strong contribution of biomass burning to DHOPA as suggested by previous studies in this region. Instead, good correlations between observed DHOPA and O x as well as [NO 2 ][O 3 ] suggest the involvement of both ozone (O 3 ) and nitrogen dioxide (NO 2 ) in the formation of DHOPA. The results showed that regional air pollution may not only increase the emissions of aromatic precursors but also can greatly promote the formation processes. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Application of FIGAERO (Filter Inlet for Gases and AEROsol) coupled to a high resolution time of flight chemical ionization mass spectrometer to field and chamber organic aerosol: Implications for carboxylic acid formation and gas-particle partitioning from monoterpene oxidation

    Science.gov (United States)

    Lopez-Hilfiker, F.; Mohr, C.; Ehn, M.; Rubach, F.; Mentel, T. F.; Kleist, E.; Wildt, J.; Thornton, J. A.

    2013-12-01

    We present measurements of a large suite of gas and particle phase carboxylic acid containing compounds made with a Filter Inlet for Gas and AEROsol (FIGAERO) coupled to a high resolution time of flight chemical ionization mass spectrometer (HR-ToF-CIMS) developed at the University of Washington. A prototype operated with acetate negative ion proton transfer chemistry was deployed on the Julich Plant Atmosphere Chamber to study a-pinene oxidation, and a modified version was deployed at the SMEAR II forest station in Hyytiälä, Finland and SOAS, in Brent Alabama. We focus here on results from JPAC and Hyytiälä, where we utilized the same ionization method most selective towards carboxylic acids. In all locations, 100's of organic acid compounds were observed in the gas and particles and many of the same composition acids detected in the gas-phase were detected in the particles upon temperature programmed thermal desorption. Particulate organics detected by FIGAERO are highly correlated with organic aerosol mass measured by an AMS, providing additional volatility and molecular level information about collected aerosol. The fraction of a given compound measured in the particle phase follows expected trends with elemental composition, but many compounds would not be well described by an absorptive partitioning model assuming unity activity coefficients. Moreover the detailed structure in the thermal desorption signals reveals a contribution from thermal decomposition of large molecular weight organics and or oligomers with implications for partitioning measurements and model validation

  17. Studies on generation and transport of sodium aerosols in some test facilities

    International Nuclear Information System (INIS)

    Sano, T.; Shimomura, T.; Hattori, N.

    1986-01-01

    Technical experiences that have been obtained during the course of the experiments to determine the sodium aerosol concentration, to study the deposition of sodium aerosol, and to predict mechanical properties of sodium vapor deposits are presented. In the first study, the sodium aerosol concentrations in an inert cover gas space over a sodium pool and those following a sodium spray injection into an inert atmosphere were determined. The results from the two different experiments were compared with each other and were discussed in comparison with those from the literature. In the second study, deposition of sodium aerosol following a sodium spray injection into an inert atmosphere was examined. The deposition rates on the walls and the floor of a closed concrete cell were measured, and the results obtained were discussed. The third study relates to the sodium vapor deposition within a narrow annulus. In the experiments, a downward argon gas flow that passes the annulus was fed to prevent sodium vapor deposition. Average sodium vapor deposition rates on the walls of the annulus were determined, then the effect of the downward feed gas was discussed. The last study relates to one of the mechanical properties and the deformation rate of solid sodium being compressed. The purpose of the experiments were to obtain data to predict deformation rate of the sodium deposits. (author)

  18. Oxidative potential of size-fractionated atmospheric aerosol in urban and rural sites across Europe.

    Science.gov (United States)

    Shafer, Martin M; Hemming, Jocelyn D C; Antkiewicz, Dagmara S; Schauer, James J

    2016-07-18

    In this study we applied several assays, an in vitro rat alveolar macrophage model, a chemical ROS probe (DTT, dithiothreitol), and cytokine induction (TNFα) to examine relationships between PM-induced generation of reactive oxygen species (ROS) and PM composition, using a unique set of size-resolved PM samples obtained from urban and rural environments across Europe. From April-July 2012, we collected PM from roadside canyon, roadside motorway, and background urban sites in each of six European cities and from three rural sites spanning the continent. A Hi-Vol sampler was used to collect PM in three size classes (PM>7, PM7-3, PM3) and PM was characterized for total elements, and oxidative activity quantified in unfiltered and filtered PM extracts. We measured a remarkable uniformity in air concentrations of ROS and especially DTT activity across the continent. Only a 4-fold difference was documented for DTT across the urban sites and a similar variance was documented for ROS, implying that chemical drivers of oxidative activity are relatively similar between sites. The ROS and DTT specific activity was greater at urban background sites (and also rural sites) than at urban canyon locations. PM3 dominated the size distribution of both ROS activity (86% of total) and DTT activity (76% of total), reflecting both the large contribution of PM3 to total PM mass levels and importantly the higher specific oxidative activity of the PM3 in comparison with the larger particles. The soluble fraction of total activity was very high for DTT (94%) as well as for ROS (64%) in the PM3. However in the larger PM size fractions the contributions of the insoluble components became increasingly significant. The dominance of the insoluble PM drivers of activity was particularly evident in the TNFα data, where the insoluble contribution to cytokine production could be 100-fold greater than that from soluble components. ROS and DTT activity were strongly correlated in the PM3 (r = 0

  19. RESULTS OF INITIAL AMMONIA OXIDATION TESTING

    Energy Technology Data Exchange (ETDEWEB)

    Nash, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Fowley, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-12-30

    This memo presents an experimental survey of aqueous phase chemical processes to remove aqueous ammonia from waste process streams. Ammonia is generated in both the current Hanford waste flowsheet and in future waste processing. Much ammonia will be generated in the Low Activity Waste (LAW) melters.i Testing with simulants in glass melters at Catholic University has demonstrated the significant ammonia production.ii The primary reaction there is the reducing action of sugar on nitrate in the melter cold cap. Ammonia has been found to be a problem in secondary waste stabilization. Ammonia vapors are noxious and destruction of ammonia could reduce hazards to waste treatment process personnel. It is easily evolved especially when ammonia-bearing solutions are adjusted to high pH.

  20. Remote detection and recognition of bio-aerosols by laser-induced fluorescense lidar: practical implementation and field tests

    Science.gov (United States)

    Boreysho, Anatoly; Savin, Andrey; Morozov, Alexey; Konyaev, Maxim; Konovalov, Konstantin

    2007-06-01

    Recognition of aerosol clouds material at some significant distance is now a key requirement for the wide range of applications. The elastic backscatter lidar have demonstrated high capabilities in aerosol remote detection, cloud real-time mapping at very long distances for low-concentration natural aerosols as well as artificial ones [1]. However, recognition ability is required to make them more relevant. Laser-induced fluorescence (LIF) looks very promising with respect to the recognition problem. New approach based on mobile lidar complex [2] equipped by spectrally-and range-resolved LIF-sensor is described as well as some results of field tests. The LIF-sensor consists of four-harmonics Nd:YAG laser equipped by an output expander to provide final beam divergence camera collimated with the lidar scanning direction. The LIF-lidar is mounted on a truck-based platform (20-feet container) as a part of multi-purpose mobile lidar complex and adjusted for field conditions.

  1. Lightning-produced NOx in an explicit electrical scheme tested in a Stratosphere-Troposphere Experiment: Radiation, Aerosols, and Ozone case study

    Science.gov (United States)

    Barthe, Christelle; Pinty, Jean-Pierre; Mari, CéLine

    2007-02-01

    An explicit lightning-produced nitrogen oxide (LNOx) scheme has been implemented in a 3-D mesoscale model. The scheme is based on the simulation of the electrical state of the cloud and provides a prediction of the temporal and spatial distribution of the lightning flashes. The frequency and the 3-D morphology of the lightning flashes are captured realistically so fresh nitrogen oxide molecules can be added along the complex flash path as a function of the pressure, as suggested by results from laboratory experiments. The scheme is tested on the 10 July 1996 Stratosphere-Troposphere Experiment: Radiation, Aerosols, and Ozone (STERAO) storm. The model reproduces many features of the observed increase of electrical activity and LNOx flux density between the multicell and supercell stages. LNOx dominates the NOx budget in the upper part of the cells with instantaneous peak concentrations exceeding 4 ppbv, as observed. The computed flux of NOx across the anvil shows a mean value of 6 mol m-2 s-1 during the last 90 min of the simulation. This value is remarkably stable and compares favorably with the observations.

  2. Predictive tests to evaluate oxidative potential of engineered nanomaterials

    Science.gov (United States)

    Ghiazza, Mara; Carella, Emanuele; Oliaro-Bosso, Simonetta; Corazzari, Ingrid; Viola, Franca; Fenoglio, Ivana

    2013-04-01

    Oxidative stress constitutes one of the principal injury mechanisms through which particulate toxicants (asbestos, crystalline silica, hard metals) and engineered nanomaterials can induce adverse health effects. ROS may be generated indirectly by activated cells and/or directly at the surface of the material. The occurrence of these processes depends upon the type of material. Many authors have recently demonstrated that metal oxides and carbon-based nanoparticles may influence (increasing or decreasing) the generation of oxygen radicals in a cell environment. Metal oxide, such as iron oxides, crystalline silica, and titanium dioxide are able to generate free radicals via different mechanisms causing an imbalance within oxidant species. The increase of ROS species may lead to inflammatory responses and in some cases to the development of cancer. On the other hand carbon-based nanomaterials, such as fullerene, carbon nanotubes, carbon black as well as cerium dioxide are able to scavenge the free radicals generated acting as antioxidant. The high numbers of new-engineered nanomaterials, which are introduced in the market, are exponentially increasing. Therefore the definition of toxicological strategies is urgently needed. The development of acellular screening tests will make possible the reduction of the number of in vitro and in vivo tests to be performed. An integrated protocol that may be used to predict the oxidant/antioxidant potential of engineered nanoparticles will be here presented.

  3. Predictive tests to evaluate oxidative potential of engineered nanomaterials

    International Nuclear Information System (INIS)

    Ghiazza, Mara; Carella, Emanuele; Corazzari, Ingrid; Fenoglio, Ivana; Oliaro-Bosso, Simonetta; Viola, Franca

    2013-01-01

    Oxidative stress constitutes one of the principal injury mechanisms through which particulate toxicants (asbestos, crystalline silica, hard metals) and engineered nanomaterials can induce adverse health effects. ROS may be generated indirectly by activated cells and/or directly at the surface of the material. The occurrence of these processes depends upon the type of material. Many authors have recently demonstrated that metal oxides and carbon-based nanoparticles may influence (increasing or decreasing) the generation of oxygen radicals in a cell environment. Metal oxide, such as iron oxides, crystalline silica, and titanium dioxide are able to generate free radicals via different mechanisms causing an imbalance within oxidant species. The increase of ROS species may lead to inflammatory responses and in some cases to the development of cancer. On the other hand carbon-based nanomaterials, such as fullerene, carbon nanotubes, carbon black as well as cerium dioxide are able to scavenge the free radicals generated acting as antioxidant. The high numbers of new-engineered nanomaterials, which are introduced in the market, are exponentially increasing. Therefore the definition of toxicological strategies is urgently needed. The development of acellular screening tests will make possible the reduction of the number of in vitro and in vivo tests to be performed. An integrated protocol that may be used to predict the oxidant/antioxidant potential of engineered nanoparticles will be here presented.

  4. Aerosol Delivery for Amendment Distribution in Contaminated Vadose Zones

    Science.gov (United States)

    Hall, R. J.; Murdoch, L.; Riha, B.; Looney, B.

    2011-12-01

    aqueous and oil deposition are assumed to occur due to surface interactions, and susceptibility to evaporation of aqueous aerosols. Distal salt accumulation during salt water aerosol tests suggests that solid salt forms as salt water aerosols evaporate. The solid salt aerosols are less likely to deposit, so they travel further than aqueous aerosols. A numerical model was calibrated using results from lab-scale tests. The calibrated model was then used to simulate field-scale aerosol injection. Results from field-scale simulations suggest that effective radii of influence on the scale of 8-10 meters could be achieved in partially saturated sand. The aerosol delivery process appears to be capable distributing oil amendments over considerable volumes of formation at concentrations appropriate for remediation purposes. Thus far, evaporation has limited liquid accumulation observed when distributing aqueous aerosols, however, results from salt water experiments suggest that injection of solid phase aerosols can effectively distribute water soluble amendments (electron donor, pH buffer, oxidants, etc.). Utilization of aerosol delivery could considerably expand treatment options for contaminated vadose zones at a wide variety of sites.

  5. Organic Aerosols in the Presence of CO{sub 2} in the Early Earth and Exoplanets: UV–Vis Refractive Indices of Oxidized Tholins

    Energy Technology Data Exchange (ETDEWEB)

    Gavilan, Lisseth; Carrasco, Nathalie; Vettier, Ludovic [LATMOS, Université Versailles St Quentin, UPMC Université Paris 06, CNRS, 11 blvd d’Alembert, F-78280 Guyancourt (France); Broch, Laurent [LCP-A2MC, Institut Jean Barriol, Université de Lorraine, Metz (France); Fleury, Benjamin, E-mail: lisseth.gavilan@latmos.ipsl.fr [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2017-10-10

    In this experimental study we investigate the role of atmospheric CO{sub 2} on the optical properties of organic photochemical aerosols. To this end, we add CO{sub 2} to a N{sub 2}:CH{sub 4} gas mixture used in a plasma typically used for Titan studies. We produce organic thin films (tholins) in plasmas where the CO{sub 2}/CH{sub 4} ratio is increased from 0 to 4. We measure these films via spectrometric ellipsometry and apply a Tauc–Lorentz model, used for optically transparent materials, to obtain the thickness of the thin film, its optical band gap, and the refractive indices in the UV–visible (270–600 nm). All samples present a significant absorption band in the UV. According to the Tauc–Lorentz model, as the CO{sub 2}/CH{sub 4} ratio is quadrupled, the position of the UV band is shifted from ∼177 nm to 264 nm while its strength is quadrupled. Consequently, we infer that oxidized organic aerosols absorb more efficiently at longer UV wavelengths than reduced aerosols. Our laboratory wavelength-tabulated UV–vis refractive indices provide new constraints to atmospheric models of the early Earth and Earth-like exoplanets including photochemical hazes formed under increasingly oxidizing conditions.

  6. Study on the deposition patterns of aerosol inhalation scintigraphy, 1; Comparison of the deposition patterns of aerosol inhalation scintigraphy with lung function tests in pulmonary diseases

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Hiroyuki [Nara Medical Univ., Kashihara (Japan)

    1989-06-01

    The deposition patterns of aerosol inhalation scintigraphies and lung function tests were studied in 102 cases; 64 cases of obstructive pulmonary diseases (19 pulmonary emphysema, 27 diffuse panbronchiolitis, 18 chronic bronchitis) and 38 restrictive pulmonary disease (15 idiopathic interstitial pneumonia, 16 pulmonary asbestosis, 7 interstitial pneumonia due to collagen vascular disease). The deposition patterns were classified into 5 patterns (Type A:normal homogenous distribution; Type B: mildly unhomogenous distribution; Type C: severely unhomogenous distribution mingled with hot spots; Type D: non-hilar hot spots; and Type E: hilar hot spots). The deposition patterns of restrictive pulmonary diseases were markedly abnormal as well as obstructive pulmonary diseases. The deposition patterns showed mainly Types C, D and E in obstructive pulmonary diseases, Type B in restrictive pulmonary diseases. The deposition patterns showed mainly Type E in pulmonary emphysema, Types C and D in diffuse panbronchiolitis, Types A, B and C in chronic bronchitis, Type B in idiopathic interstitial pneumonia interstitial pneumonia due to collagen vascular disease, Types B and C in pulmonary asbestosis. The deposition patterns correlated well with %FEV{sub 1.0} which was a good indicator of the severity of obstructive pulmonary diseases and restrictive pulmonary diseases. Furthermore, the mean %FEV{sub 1.0} in obstructive pulmonary diseases was nearly equal to the mean %FEV{sub 1.0} in restrictive pulmonary diseases in each type of the deposition patterns. (J.P.N.).

  7. High temperature oxidation test of oxide dispersion strengthened (ODS) steel claddings

    International Nuclear Information System (INIS)

    Narita, Takeshi; Ukai, Shigeharu; Kaito, Takeji; Ohtsuka, Satoshi; Matsuda, Yasushi

    2006-07-01

    In a feasibility study of ODS steel cladding, its high temperature oxidation resistance was evaluated. Although addition of Cr is effective for preventing high temperature oxidation, excessively higher amount of Cr leads to embrittlement due to the Cr-rich α' precipitate formation. In the ODS steel developed by the Japan Atomic Energy Agency (JAEA), the Cr content is controlled in 9Cr-ODS martensite and 12Cr-ODS ferrite. In this study, high temperature oxidation test was conducted for ODS steels, and their results were compared with that of conventional austenitic stainless steel and ferritic-martensitic stainless steel. Following results were obtained in this study. (1) 9Cr-ODS martensitic and 12Cr-ODS ferritic steel have superior high temperature oxidation resistance compared to 11mass%Cr PNC-FMS and even 17mass% SUS430 and equivalent to austenitic PNC316. (2) The superior oxidation resistance of ODS steel was attributed to earlier formation of the protective alpha-Cr 2 O 3 layer at the matrix and inner oxide scale interface. The grain size of ODS steel is finer than that of PNC-FMS, so the superior oxidation resistance of ODS steel can be attributed to the enhanced Cr-supplying rate throughout the accelerated grain boundary diffusion. Finely dispersed Y 2 O 3 oxide particles in the ODS steel matrix may also stabilized the adherence between the protective alpha-Cr 2 O 3 layer and the matrix. (author)

  8. Aerosol filtration

    International Nuclear Information System (INIS)

    Klein, M.; Goossens, W.R.A.; De Smet, M.; Trine, J.; Hertschap, M.

    1984-01-01

    This report summarizes the work on the development of fibre metallic prefilters to be placed upstream of HEPA filters for the exhaust gases of nuclear process plants. Investigations at ambient and high temperature were carried out. Measurements of the filtration performance of Bekipor porous webs and sintered mats were performed in the AFLT (aerosol filtration at low temperature) unit with a throughput of 15 m 3 /h. A parametric study on the influence of particle size, fibre diameter, number of layers and superficial velocity led to the optimum choice of the working parameters. Three selected filter types were then tested with polydisperse aerosols using a candle-type filter configuration or a flat-type filter configuration. The small-diameter candle type is not well suited for a spraying nozzles regeneration system so that only the flat-type filter was retained for high-temperature tests. A high-temperature test unit (AFHT) with a throughput of 8 to 10 m 3 /h at 400 0 C was used to test the three filter types with an aerosol generated by high-temperature calcination of a simulated nitric acid waste solution traced with 134 Cs. The regeneration of the filter by spray washing and the effect of the regeneration on the filter performance was studied for the three filter types. The porous mats have a higher dust loading capacity than the sintered web which means that their regeneration frequency can be kept lower

  9. Photo-oxidation products of α-pinene in coarse, fine and ultrafine aerosol: A new high sensitive HPLC-MS/MS method

    Science.gov (United States)

    Feltracco, Matteo; Barbaro, Elena; Contini, Daniele; Zangrando, Roberta; Toscano, Giuseppa; Battistel, Dario; Barbante, Carlo; Gambaro, Andrea

    2018-05-01

    Oxidation products of α-pinene represent a fraction of organic matter in the environmental aerosol. α-pinene is one of most abundant monoterpenes released in the atmosphere by plants, located typically in boreal, temperate and tropical forests. This primary compound reacts with atmospheric oxidants, such as O3, O2, OH radicals and NOx, through the major tropospheric degradation pathway for many monoterpenes under typical atmospheric condition. Although several studies identified a series of by-products deriving from the α-pinene photo-oxidation in the atmosphere, such as pinic and cis-pinonic acid, the knowledge of the mechanism of this process is partially still lacking. Thus, the investigation of the distribution of these acids in the different size aerosol particles provides additional information on this regard. The aim of this study is twofold. First, we aim to improve the existing analytical methods for the determination of pinic and cis-pinonic acid in aerosol samples, especially in terms of analytical sensitivity and limits of detection (LOD) and quantification (LOQ). We even attempted to increase the knowledge of the α-pinene photo-oxidation processes by analysing, for the first time, the particle-size distribution up to nanoparticle level of pinic and cis-pinonic acid. The analysis of aerosol samples was carried out via high-performance liquid chromatography coupled to a triple quadrupole mass spectrometer. The instrumental LOD values of cis-pinonic and pinic acid are 1.6 and 1.2 ng L-1 while LOQ values are 5.4 and 4.1 ng L-1, respectively. Samples were collected by MOUDI II™ cascade impactor with twelve cut-sizes, from March to May 2016 in the urban area of Mestre-Venice (Italy). The range concentrations in the aerosol samples were from 0.1 to 0.9 ng m-3 for cis-pinonic acid and from 0.1 to 0.8 ng m-3 for pinic acid.

  10. Processing methods for operation test data of radioactive aerosols monitor based on accumulation techniques

    International Nuclear Information System (INIS)

    Fu Cuiming; Xi Pingping; Ma Yinghao; Tan Linglong; Shen Fu

    2011-01-01

    This article introduces a radioactive aerosol continuous monitor based on accumulation sampling and measuring and three methods for processing the operation data. The monitoring results are processed by the 3 methods which are applied both under the conditions of natural background and at workplaces of a nuclear facility. How the monitoring results are assessed and how to calculate the detection limit when using the 3 different methods are explained. Moreover, the advantages and disadvantages of the 3 methods are discussed. (authors)

  11. Crumpling of graphene oxide through evaporative confinement in nanodroplets produced by electrohydrodynamic aerosolization

    Energy Technology Data Exchange (ETDEWEB)

    Kavadiya, Shalinee; Raliya, Ramesh; Schrock, Michael; Biswas, Pratim, E-mail: pbiswas@wustl.edu [Washington University in St. Louis, Aerosol and Air Quality Research Laboratory, Department of Energy, Environmental and Chemical Engineering (United States)

    2017-02-15

    Restacking of graphene oxide (GO) nanosheets results in loss of surface area and creates limitations in its widespread use for applications. Previously, two-dimensional (2D) GO sheets have been crumpled into 3D structures to prevent restacking using different techniques. However, synthesis of nanometer size crumpled graphene particles and their direct deposition onto a substrate have not been demonstrated under room temperature condition so far. In this work, the evaporative crumpling of GO sheets into very small size (<100 nm) crumpled structures using an electrohydrodynamic atomization technique is described. Systematic study of the effect of different electrohydrodynamic atomization parameters, such as (1) substrate-to-needle distance, (2) GO concentration in the precursor solution, and (3) flow rate (droplet size) on the GO crumpling, is explored. Crumpled GO (CGO) particles are characterized online using a scanning mobility particle sizer (SMPS) and off-line using electron microscopy. The relation between the confinement force and the factors affecting the crumpled structure is established. Furthermore, to expand the application horizons of the structure, crumpled GO–TiO{sub 2} nanocomposites are synthesized. The method described here allows a simple and controlled production of graphene-based particles/composites with direct deposition onto any kind of substrate for a variety of applications.

  12. Positive patch test reactions to oxidized limonene: exposure and relevance.

    Science.gov (United States)

    Bråred Christensson, Johanna; Andersen, Klaus E; Bruze, Magnus; Johansen, Jeanne D; Garcia-Bravo, Begoña; Gimenez Arnau, Ana; Goh, Chee-Leok; Nixon, Rosemary; White, Ian R

    2014-11-01

    R-Limonene is a common fragrance terpene found in domestic and industrial products. R-Limonene autoxidizes on air exposure, and the oxidation products can cause contact allergy. In a recent multicentre study, 5.2% (range 2.3-12.1%) of 2900 patients showed a positive patch test reaction to oxidized R-limonene. To study the exposure to limonene among consecutive dermatitis patients reacting to oxidized R-limonene in an international setting, and to assess the relevance of the exposure for the patients' dermatitis. Oxidized R-limonene 3.0% (containing limonene hydroperoxides at 0.33%) in petrolatum was tested in 2900 consecutive dermatitis patients in Australia, Denmark, the United Kingdom, Singapore, Spain, and Sweden. A questionnaire assessing exposure to limonene-containing products was completed. Overall, exposure to products containing limonene was found and assessed as being probably relevant for the patients' dermatitis in 36% of the limonene-allergic patients. In Barcelona and Copenhagen, > 70% of the patients were judged to have had an exposure to limonene assessed as relevant. Oxidized R-limonene is a common fragrance allergen, and limonene was frequently found in the labelling on the patients' products, and assessed as relevant for the patients' dermatitis. A large number of domestic and occupational sources for contact with R-limonene were identified. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Environmental Technology Verification: Supplement to Test/QA Plan for Biological and Aerosol Testing of General Ventilation Air Cleaners; Bioaerosol Inactivation Efficiency by HVAC In-Duct Ultraviolet Light Air Cleaners

    Science.gov (United States)

    The Air Pollution Control Technology Verification Center has selected general ventilation air cleaners as a technology area. The Generic Verification Protocol for Biological and Aerosol Testing of General Ventilation Air Cleaners is on the Environmental Technology Verification we...

  14. Biogenic oxidized organic functional groups in aerosol particles from a mountain forest site and their similarities to laboratory chamber products

    Science.gov (United States)

    Schwartz, R. E.; Russell, L. M.; Sjostedt, S. J.; Vlasenko, A.; Slowik, J. G.; Abbatt, J. P. D.; MacDonald, A. M.; Li, S. M.; Liggio, J.; Toom-Sauntry, D.; Leaitch, W. R.

    2010-06-01

    Submicron particles collected at Whistler, British Columbia, at 1020 m a.s.l. during May and June 2008 on Teflon filters were analyzed by Fourier transform infrared (FTIR) and X-ray fluorescence (XRF) techniques for organic functional groups (OFG) and elemental composition. Organic mass (OM) concentrations ranged from less than 0.5 to 3.1 μg m-3, with a project mean and standard deviation of 1.3±1.0 μg m-3 and 0.21±0.16 μg m-3 for OM and sulfate, respectively. On average, organic hydroxyl, alkane, and carboxylic acid groups represented 34%, 33%, and 23% of OM, respectively. Ketone, amine and organosulfate groups constituted 6%, 5%, and volatile organic compounds (VOC), including isoprene and monoterpenes from biogenic VOC (BVOC) emissions and their oxidation products (methyl-vinylketone / methacrolein, MVK/MACR), were made using co-located proton transfer reaction mass spectrometry (PTR-MS). We present chemically-specific evidence of OFG associated with BVOC emissions. Positive matrix factorization (PMF) analysis attributed 65% of the campaign OM to biogenic sources, based on the correlations of one factor to monoterpenes and MVK/MACR. The remaining fraction was attributed to anthropogenic sources based on a correlation to sulfate. The functional group composition of the biogenic factor (consisting of 32% alkane, 25% carboxylic acid, 21% organic hydroxyl, 16% ketone, and 6% amine groups) was similar to that of secondary organic aerosol (SOA) reported from the oxidation of BVOCs in laboratory chamber studies, providing evidence that the magnitude and chemical composition of biogenic SOA simulated in the laboratory is similar to that found in actual atmospheric conditions. The biogenic factor OM is also correlated to dust elements, indicating that dust may act as a non-acidic SOA sink. This role is supported by the organic functional group composition and morphology of single particles, which were analyzed by scanning transmission X-ray microscopy near edge X

  15. Interpreting the ultraviolet aerosol index observed with the OMI satellite instrument to understand absorption by organic aerosols: implications for atmospheric oxidation and direct radiative effects

    Directory of Open Access Journals (Sweden)

    M. S. Hammer

    2016-03-01

    Full Text Available Satellite observations of the ultraviolet aerosol index (UVAI are sensitive to absorption of solar radiation by aerosols; this absorption affects photolysis frequencies and radiative forcing. We develop a global simulation of the UVAI using the 3-D chemical transport model GEOS-Chem coupled with the Vector Linearized Discrete Ordinate Radiative Transfer model (VLIDORT. The simulation is applied to interpret UVAI observations from the Ozone Monitoring Instrument (OMI for the year 2007. Simulated and observed values are highly consistent in regions where mineral dust dominates the UVAI, but a large negative bias (−0.32 to −0.97 exists between simulated and observed values in biomass burning regions. We determine effective optical properties for absorbing organic aerosol, known as brown carbon (BrC, and implement them into GEOS-Chem to better represent observed UVAI values over biomass burning regions. The inclusion of absorbing BrC decreases the mean bias between simulated and OMI UVAI values from −0.57 to −0.09 over West Africa in January, from −0.32 to +0.0002 over South Asia in April, from −0.97 to −0.22 over southern Africa in July, and from −0.50 to +0.33 over South America in September. The spectral dependence of absorption after including BrC in the model is broadly consistent with reported observations for biomass burning aerosol, with absorbing Ångström exponent (AAE values ranging from 2.9 in the ultraviolet (UV to 1.3 across the UV–Near IR spectrum. We assess the effect of the additional UV absorption by BrC on atmospheric photochemistry by examining tropospheric hydroxyl radical (OH concentrations in GEOS-Chem. The inclusion of BrC decreases OH by up to 30 % over South America in September, up to 20 % over southern Africa in July, and up to 15 % over other biomass burning regions. Global annual mean OH concentrations in GEOS-Chem decrease due to the presence of absorbing BrC, increasing the methyl chloroform

  16. Interpreting the Ultraviolet Aerosol Index Observed with the OMI Satellite Instrument to Understand Absorption by Organic Aerosols: Implications for Atmospheric Oxidation and Direct Radiative Effects

    Science.gov (United States)

    Hammer, Melanie S.; Martin, Randall V.; Donkelaar, Aaron van; Buchard, Virginie; Torres, Omar; Ridley, David A.; Spurr, Robert J. D.

    2016-01-01

    Satellite observations of the ultraviolet aerosol index (UVAI) are sensitive to absorption of solar radiation by aerosols; this absorption affects photolysis frequencies and radiative forcing. We develop a global simulation of the UVAI using the 3-D chemical transport model GEOSChem coupled with the Vector Linearized Discrete Ordinate Radiative Transfer model (VLIDORT). The simulation is applied to interpret UVAI observations from the Ozone Monitoring Instrument (OMI) for the year 2007. Simulated and observed values are highly consistent in regions where mineral dust dominates the UVAI, but a large negative bias (-0.32 to -0.97) exists between simulated and observed values in biomass burning regions. We determine effective optical properties for absorbing organic aerosol, known as brown carbon (BrC), and implement them into GEOS-Chem to better represent observed UVAI values over biomass burning regions. The inclusion of absorbing BrC decreases the mean bias between simulated and OMI UVAI values from -0.57 to -0.09 over West Africa in January, from -0.32 to +0.0002 over South Asia in April, from -0.97 to -0.22 over southern Africa in July, and from -0.50 to +0.33 over South America in September. The spectral dependence of absorption after including BrC in the model is broadly consistent with reported observations for biomass burning aerosol, with absorbing Angstrom exponent (AAE) values ranging from 2.9 in the ultraviolet (UV) to 1.3 across the UV-Near IR spectrum. We assess the effect of the additional UV absorption by BrC on atmospheric photochemistry by examining tropospheric hydroxyl radical (OH) concentrations in GEOS-Chem. The inclusion of BrC decreases OH by up to 30% over South America in September, up to 20% over southern Africa in July, and up to 15% over other biomass burning regions. Global annual mean OH concentrations in GEOS-Chem decrease due to the presence of absorbing BrC, increasing the methyl chloroform lifetime from 5.62 to 5.68 years, thus

  17. Late effects following inhalation of mixed oxide (U,PuO2) mox aerosol in the rat

    International Nuclear Information System (INIS)

    Griffiths, N.; Van Der Meeren, A.; Fritsch, P.; Maximilien, R.

    2008-01-01

    Exposure to alpha-emitting particles is a potential long-term health risk to workers in nuclear fuel fabrication plants. Mixed Oxide (MOX: U,PuO 2 ) fuels containing low percentages of plutonium obtained from spent nuclear fuels are increasingly employed and in the case of accidental contamination by inhalation or wounds may result in the development of late-occurring pathologies such as lung cancer. However the long term risks particularly with regard to lung cancer are to date unclear. In the case of MOX the risk may indeed be different from that assigned to the individual components, plutonium and uranium. Several factors are influential (i) the dissolution of Pu depends on the physico-chemical properties, for example risk of lung cancer is increased 10 fold after Pu(NO 3 ) 2 as compared with PuO 2 . (ii) The solubility of Pu is variable whether delivered as PuO 2 or contained within MOX. (iii) The risk of cancer appears to increase with spatial homogeneity of the lung alpha dose. The objective of this study was to investigate the long term effects in rat lungs following MOX aerosol inhalation of similar particle size containing 2.5 or 7.1% Pu. Conscious rats were exposed to MOX aerosols using a 'nose-only' system and kept for their entire life (2-3 years). Different Initial Lung Deposits (ILDs) were obtained using different concentrations of the MOX suspension. Lung total alpha activity was determined in vivo at intervals over the study period by external counting as well as at autopsy in order to estimate the total lung dose. Anatomo-pathological and immunohistochemical analyses were performed on fixed lung tissue after euthanasia. The frequencies of lung pathologies and tumours were determined on lung sections at several different levels. In addition, autoradiography of lung sections was performed in order to assess the spatial localisation of a activity. Inhalation of MOX at ILD ranging from 1-20 kBq resulted in lung pathologies (90% of exposed rats

  18. Emergency Response Proficiency Test for Japanese Laboratories: Determination of Selected Radionuclides in Water, Soil, Vegetation and Aerosol Filters

    International Nuclear Information System (INIS)

    2013-01-01

    Reliable determination of natural and artificial radionuclides in environmental samples is necessary for compliance with radiation protection and environmental regulations. The IAEA assists Member State laboratories in maintaining and improving their readiness in this regard by producing reference materials, by developing standardized analytical methods, and by conducting interlaboratory comparisons and proficiency tests as tools for quality control. To fulfil this obligation and ensure a reliable, rapid and consistent worldwide response, the IAEA Terrestrial Environment Laboratory in Seibersdorf, Austria, organizes interlaboratory comparisons and proficiency tests. In addition, the IAEA coordinates the worldwide network of Analytical Laboratories for the Measurement of Environmental Radioactivity (ALMERA). After the accident at the Fukushima Daiichi nuclear power plant in March 2011, Japan requested the IAEA to organize an emergency response proficiency test for Japanese laboratories with the aim of assessing their capacity to rapidly and accurately measure radionuclides in environmental samples. The IAEA responded to the request by assembling a special sample set covering the main environmental samples and radionuclides of interest in the case of a nuclear emergency situation. Water, soil, vegetation and aerosol filter samples were made available to Japanese laboratories for analysis by gamma ray spectrometry. This report presents the results of the IAEA-TEL-2011-08 emergency response proficiency test for Japanese laboratories on the determination of selected radionuclides in water, soil, vegetation and aerosol filters. The report includes descriptions of the methodologies and data evaluation approach used, as well as summary evaluations of each radionuclide and individual evaluation reports of each laboratory. This proficiency test was designed to identify analytical problems and to support Member State laboratories in their efforts to improve the quality of

  19. Chemical and physical transformations of organic aerosol from the photo-oxidation of open biomass burning emissions in an environmental chamber

    Directory of Open Access Journals (Sweden)

    C. J. Hennigan

    2011-08-01

    Full Text Available Smog chamber experiments were conducted to investigate the chemical and physical transformations of organic aerosol (OA during photo-oxidation of open biomass burning emissions. The experiments were carried out at the US Forest Service Fire Science Laboratory as part of the third Fire Lab at Missoula Experiment (FLAME III. We investigated emissions from 12 different fuels commonly burned in North American wildfires. The experiments feature atmospheric and plume aerosol and oxidant concentrations; aging times ranged from 3 to 4.5 h. OA production, expressed as a mass enhancement ratio (ratio of OA to primary OA (POA mass, was highly variable. OA mass enhancement ratios ranged from 2.9 in experiments where secondary OA (SOA production nearly tripled the POA concentration to 0.7 in experiments where photo-oxidation resulted in a 30 % loss of the OA mass. The campaign-average OA mass enhancement ratio was 1.7 ± 0.7 (mean ± 1σ; therefore, on average, there was substantial SOA production. In every experiment, the OA was chemically transformed. Even in experiments with net loss of OA mass, the OA became increasingly oxygenated and less volatile with aging, indicating that photo-oxidation transformed the POA emissions. Levoglucosan concentrations were also substantially reduced with photo-oxidation. The transformations of POA were extensive; using levoglucosan as a tracer for POA, unreacted POA only contributed 17 % of the campaign-average OA mass after 3.5 h of exposure to typical atmospheric hydroxyl radical (OH levels. Heterogeneous reactions with OH could account for less than half of this transformation, implying that the coupled gas-particle partitioning and reaction of semi-volatile vapors is an important and potentially dominant mechanism for POA processing. Overall, the results illustrate that biomass burning emissions are subject to extensive chemical processing in the atmosphere, and the timescale for these transformations is rapid.

  20. Warm Water Oxidation Verification - Scoping and Stirred Reactor Tests

    Energy Technology Data Exchange (ETDEWEB)

    Braley, Jenifer C.; Sinkov, Sergey I.; Delegard, Calvin H.; Schmidt, Andrew J.

    2011-06-15

    Scoping tests to evaluate the effects of agitation and pH adjustment on simulant sludge agglomeration and uranium metal oxidation at {approx}95 C were performed under Test Instructions(a,b) and as per sections 5.1 and 5.2 of this Test Plan prepared by AREVA. (c) The thermal testing occurred during the week of October 4-9, 2010. The results are reported here. For this testing, two uranium-containing simulant sludge types were evaluated: (1) a full uranium-containing K West (KW) container sludge simulant consisting of nine predominant sludge components; (2) a 50:50 uranium-mole basis mixture of uraninite [U(IV)] and metaschoepite [U(VI)]. This scoping study was conducted in support of the Sludge Treatment Project (STP) Phase 2 technology evaluation for the treatment and packaging of K-Basin sludge. The STP is managed by CH2M Hill Plateau Remediation Company (CHPRC) for the U.S. Department of Energy. Warm water ({approx}95 C) oxidation of sludge, followed by immobilization, has been proposed by AREVA and is one of the alternative flowsheets being considered to convert uranium metal to UO{sub 2} and eliminate H{sub 2} generation during final sludge disposition. Preliminary assessments of warm water oxidation have been conducted, and several issues have been identified that can best be evaluated through laboratory testing. The scoping evaluation documented here was specifically focused on the issue of the potential formation of high strength sludge agglomerates at the proposed 95 C process operating temperature. Prior hydrothermal tests conducted at 185 C produced significant physiochemical changes to genuine sludge, including the formation of monolithic concretions/agglomerates that exhibited shear strengths in excess of 100 kPa (Delegard et al. 2007).

  1. Warm Water Oxidation Verification - Scoping and Stirred Reactor Tests

    International Nuclear Information System (INIS)

    Braley, Jenifer C.; Sinkov, Sergey I.; Delegard, Calvin H.; Schmidt, Andrew J.

    2011-01-01

    Scoping tests to evaluate the effects of agitation and pH adjustment on simulant sludge agglomeration and uranium metal oxidation at ∼95 C were performed under Test Instructions(a,b) and as per sections 5.1 and 5.2 of this Test Plan prepared by AREVA. (c) The thermal testing occurred during the week of October 4-9, 2010. The results are reported here. For this testing, two uranium-containing simulant sludge types were evaluated: (1) a full uranium-containing K West (KW) container sludge simulant consisting of nine predominant sludge components; (2) a 50:50 uranium-mole basis mixture of uraninite (U(IV)) and metaschoepite (U(VI)). This scoping study was conducted in support of the Sludge Treatment Project (STP) Phase 2 technology evaluation for the treatment and packaging of K-Basin sludge. The STP is managed by CH2M Hill Plateau Remediation Company (CHPRC) for the U.S. Department of Energy. Warm water (∼95 C) oxidation of sludge, followed by immobilization, has been proposed by AREVA and is one of the alternative flowsheets being considered to convert uranium metal to UO 2 and eliminate H 2 generation during final sludge disposition. Preliminary assessments of warm water oxidation have been conducted, and several issues have been identified that can best be evaluated through laboratory testing. The scoping evaluation documented here was specifically focused on the issue of the potential formation of high strength sludge agglomerates at the proposed 95 C process operating temperature. Prior hydrothermal tests conducted at 185 C produced significant physiochemical changes to genuine sludge, including the formation of monolithic concretions/agglomerates that exhibited shear strengths in excess of 100 kPa (Delegard et al. 2007).

  2. Supercritical water oxidation data acquisition testing. Final report, Volume II

    International Nuclear Information System (INIS)

    1996-11-01

    Supercritical Water Oxidation (SCWO) technology holds great promise for treating mixed wastes, in an environmentally safe and efficient manner. In the spring of 1994 the US Department of Energy (DOE), Idaho Operations Office awarded Stone ampersand Webster Engineering Corporation, of Boston Massachusetts and its sub-contractor MODAR, Inc. of Natick Massachusetts a Supercritical Water Oxidation Data Acquisition Testing (SCWODAT) program. The SCWODAT program was contracted through a Cooperative Agreement that was co-funded by the US Department of Energy and the Strategic Environmental Research and Development Program. The SCWODAT testing scope outlined by the DOE in the original Cooperative Agreement and amendments thereto was initiated in June 1994 and successfully completed in December 1995. The SCWODAT program provided further information and operational data on the effectiveness of treating both simulated mixed waste and typical Navy hazardous waste using the MODAR SCWO technology

  3. Ice nucleation onto Arizona test dust at cirrus temperatures: effect of temperature and aerosol size on onset relative humidity.

    Science.gov (United States)

    Kanji, Z A; Abbatt, J P D

    2010-01-21

    The University of Toronto Continuous Flow Diffusion Chamber (UT-CFDC) was used to study ice formation onto monodisperse Arizona Test Dust (ATD) particles. The onset relative humidity with respect to ice (RH(i)) was measured as a function of temperature in the range 251-223 K for 100 nm ATD particles. It was found that for 0.1% of the particles to freeze, water saturation was required at all temperatures except 223 K where particles activated at RH(i) below water saturation. At this temperature, where deposition mode freezing is occurring, we find that the larger the particle size, the lower the onset RH(i). We also demonstrate that the total number of particles present may influence the onset RH(i) observed. The surface area for ice activation, aerosol size, and temperature must all be considered when reporting onset values of ice formation onto ATD mineral dust particles. In addition, we calculate nucleation rates and contact angles of ice germs with ATD aerosols which indicate that there exists a range of active sites on the surface with different efficiencies for activating ice formation.

  4. Supercritical water oxidation benchscale testing metallurgical analysis report

    International Nuclear Information System (INIS)

    Norby, B.C.

    1993-02-01

    This report describes metallurgical evaluation of witness wires from a series of tests using supercritical water oxidation (SCWO) to process cutting oil containing a simulated radionuclide. The goal of the tests was to evaluate the technology's ability to process a highly chlorinated waste representative of many mixed waste streams generated in the DOE complex. The testing was conducted with a bench-scale SCWO system developed by the Modell Development Corporation. Significant test objectives included process optimization for adequate destruction efficiency, tracking the radionuclide simulant and certain metals in the effluent streams, and assessment of reactor material degradation resulting from processing a highly chlorinated waste. The metallurgical evaluation described herein includes results of metallographic analysis and Scanning Electron Microscopy analysis of witness wires exposed to the SCWO environment for one test series

  5. Preparation and microstructural properties of erbium doped alumina–yttria oxide thin films deposited by aerosol MOCVD

    Energy Technology Data Exchange (ETDEWEB)

    Salhi, Rached, E-mail: salhi_rached@yahoo.fr [Laboratoire de Science et Ingénierie des MAtériaux et Procédés 1130 rue de la PiscineBP 75-F-38402 Saint Martin D’Hères Cedex 1 (France); Laboratoire des Matériaux et du Génie Physique, CNRS UMR 5628, INP Grenoble-Minatec, 3 parvis Louis Néel BP 257, 38 016 Grenoble Cedex 1 (France); Jimenez, Carmen; Deschanvres, Jean-Luc [Laboratoire des Matériaux et du Génie Physique, CNRS UMR 5628, INP Grenoble-Minatec, 3 parvis Louis Néel BP 257, 38 016 Grenoble Cedex 1 (France); Guyot, Yannick [LPCML-UMR 5620 CNRS/UCBL Universite´ Claude Bernard Lyon 110 Rue Ada Byron 69622 Villeurbanne Cedex (France); Chaix-Pluchery, Odette; Rapenne, Laetitia [Laboratoire des Matériaux et du Génie Physique, CNRS UMR 5628, INP Grenoble-Minatec, 3 parvis Louis Néel BP 257, 38 016 Grenoble Cedex 1 (France); Maâlej, Ramzi [LPCML-UMR 5620 CNRS/UCBL Universite´ Claude Bernard Lyon 110 Rue Ada Byron 69622 Villeurbanne Cedex (France); Fourati, Mohieddine [Laboratoire de Chimie Industrielle, Ecole Nationale d’Ingénieur de Sfax, University of Sfax BP W 3038 Sfax (Tunisia); Laboratoire de Physique Appliquée, Groupe de Physique Théorique, Département de Physique, Faculté des Sciences de Sfax, University of Sfax 3018 Sfax (Tunisia)

    2013-10-15

    Erbium-doped aluminum–yttrium oxide films (Er: Al{sub 2}O{sub 3}–Y{sub 2}O{sub 3}) were prepared by aerosol-UV assisted Metalorganic Chemical Vapor Deposition (MOCVD) at 410 °C and annealed at 1000 °C. The effects of humidity of carrier gas and UV-assistance on their structure and optical properties were investigated using scanning electron microscope, X-ray diffraction and Transmission electron microscopy. It was found that under low air humidity and without UV-assistance the films present a low mol% Al{sub 2}O{sub 3} (10 mol%) two different structural phases are observed corresponding to the cubic and the monoclinic structures of Y{sub 2}O{sub 3}. When the deposition takes place under high air humidity and with UV assistance the Er:Al{sub 2}O{sub 3}–Y{sub 2}O{sub 3} films present a very high mol% Al{sub 2}O{sub 3} (88 mol%) and crystallize in the Y{sub 3}Al{sub 5}O{sub 12} (YAG) compound mixed with an amorphous phase. The Er{sup 3+} luminescence analyzed in the visible and IR regions, shows the classical green transitions. The best optical properties were obtained with the Er:Al{sub 2}O{sub 3}–Y{sub 2}O{sub 3} films grown under high air humidity with UV-assistance. Under such deposition conditions, {sup 4}I{sub 13/2} lifetimes was found to be 1.1 ms. This indicates that the deposition conditions, in particular air humidity, play an important role in the luminescent properties even after annealing. -- Highlights: • We investigate the effects of humidity and UV on the properties of Er:Al{sub 2}O{sub 3}–Y{sub 2}O{sub 3}. • Under low air humidity and without UV-assistance the films present a low mol% Al{sub 2}O{sub 3}. • Under high air humidity and with UV the Er:Al{sub 2}O{sub 3}–Y{sub 2}O{sub 3} present high mol% Al{sub 2}O{sub 3}. • The film crystallize in the YAG phase mixed with an amorphous phase. • The best optical properties were obtained under high air humidity with UV-assistance.

  6. On bacteria oxidizing enlargement scale test for uranium in-situ leaching at. 381 mine

    International Nuclear Information System (INIS)

    Hu Kaiguang; Wang Qingliang; Liu Yingjiu; Shi Wenge; Hu Shihe; Hu Yincai; Fang Qiu

    1999-01-01

    The results of enlarged scale test of bacteria as oxidizer for uranium in-situ leaching at No 381 mine showed that redox potential of the oxidized absorbed tailing water by bacteria is more than 510 mV, without any effects on after treatments by using bacteria as oxidizer and reduce oxidizer costs 70% compared with H 2 O 2 as oxidizer

  7. Laboratory testing of ozone oxidation of Hanford site waste

    International Nuclear Information System (INIS)

    Delegard, C.H.; Stubbs, A.M.; Bolling, S.D.; Colby, S.A.

    1994-01-01

    Organic constituents in radioactive waste stored in underground tanks at the U.S. Department of Energy's Hanford Site provoke safety concerns arising from their low-temperature reactions with nitrate and nitrite oxidants. Destruction of the organics would eliminate both safety problems. Oxone oxidation was investigated to destroy organic species present in simulated and genuine waste from Hanford Site Tank 241-SY-101. Bench-scale tests showed high-shear mixing apparatus achieved efficient gas-to-solution mass transfer and utilization of the ozone reagent. Oxidations of nitrite (to form nitrate) and organic species were observed. The organics formed carbonate and oxalate as well as nitrate and nitrogen gas from organic nitrogen. Formate, acetate and oxalate were present both in source waste and as reaction intermediates. Metal species oxidations also were observed directly or inferred by solubilities. Chemical precipitations of metal ions such as strontium and americium occurred as the organic species were destroyed by ozone. Reaction stoichiometries were consistent with the reduction of one oxygen atom per ozone molecule

  8. Aerosol in the containment

    International Nuclear Information System (INIS)

    Lanza, S.; Mariotti, P.

    1986-01-01

    The US program LACE (LWR Aerosol Containment Experiments), in which Italy participates together with several European countries, Canada and Japan, aims at evaluating by means of a large scale experimental activity at HEDL the retention in the pipings and primary container of the radioactive aerosol released following severe accidents in light water reactors. At the same time these experiences will make available data through which the codes used to analyse the behaviour of the aerosol in the containment and to verify whether by means of the codes of thermohydraulic computation it is possible to evaluate with sufficient accuracy variable influencing the aerosol behaviour, can be validated. This report shows and compares the results obtained by the participants in the LACE program with the aerosol containment codes NAVA 5 and CONTAIN for the pre-test computations of the test LA 1, in which an accident called containment by pass is simulated

  9. 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

  10. Considerations in Execution of High Temperature Steam Oxidation Testing

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Andrew T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-04-01

    The Fuel Cycle Research and Development program’s Advanced Fuels Campaign is currently supporting a range of experimental efforts aimed at development and qualification of so-called ‘accident tolerant’ nuclear fuel forms. Numerous criteria have been developed by which proposed systems will be investigated; foremost among these will be their resistance to oxidation at high temperatures by steamdominated atmospheres. Experimental characterization of the various proposed systems is currently ongoing at numerous national laboratories as well as at industrial and university partners using a wide range of different laboratory equipment and techniques. This requires consideration of differences that may develop among test protocols due to both intrinsic (e.g. differences between experimental capabilities) and extrinsic (e.g. methodology of test execution) factors. These are essential to understand to provide confidence across institutions in the data collected if it is used to justify resources for further investigation. The focus of this document is to provide an initial discussion of factors that may play a role in governing the observed oxidation of a test sample. It will remain up to the principle investigator to judge whether a specific factor discussed is directly applicable to the system under investigation. The purpose of the specific experiment must also guide determination of whether a given factor requires careful consideration or not.

  11. Atmospheric oxidation of 1,3-butadiene: characterization of gas and aerosol reaction products and implications for PM2.5

    Science.gov (United States)

    Jaoui, M.; Lewandowski, M.; Docherty, K.; Offenberg, J. H.; Kleindienst, T. E.

    2014-12-01

    examined. The contribution of SOA products from 13BD oxidation to ambient PM2.5 was investigated by analyzing a series of ambient PM2.5 samples collected in several locations around the United States. In addition to the occurrence of several organic compounds in field and laboratory samples, glyceric acid, d-threitol, erythritol, erythrose, and threonic acid were found to originate only from the oxidation of 13BD based on our previous experiments involving chamber oxidation of a series of hydrocarbons. Initial attempts have been made to quantify the concentrations of these compounds. The average concentrations of these compounds in ambient PM2.5 samples from the California Research at the Nexus of Air Quality and Climate Change (CalNex) study ranged from 0 to approximately 14.1 ng m-3. The occurrence of several other compounds in both laboratory and field samples suggests that SOA originating from 13BD oxidation could contribute to the ambient aerosol mainly in areas with high 13BD emission rates.

  12. Run-beyond-clad-breach oxide testing in EBR-2

    International Nuclear Information System (INIS)

    Lambert, J.D.B.; Bottcher, J.H.; Strain, R.V.; Gross, K.C.; Lee, M.J.; Webb, J.P.; Colburn, R.P.; Ukai, S.; Nomura, S.; Odo, T.; Shikakura, S.

    1990-01-01

    Fourteen tests sponsored by the US and Japan were used to study reliability of breached LMR oxide fuel pins during continued operation in EBR-II for a range of conditions and parameters. The fuel-sodium reaction product governed pin behavior. It extended primary breaches by swelling and promoted secondary failures, yet it inhibited loss of fuel and fission products and enhanced release of delayed neutrons used in monitoring breach condition. Fission gas and cesium, the main contaminants from failures, could be adequately controlled. This positive EBR-II experience suggested that limited operation with failed fuel may be feasible in commercial LMR's. 16 refs., 14 figs., 4 tabs

  13. Organic aerosols

    International Nuclear Information System (INIS)

    Penner, J.E.

    1994-01-01

    Organic aerosols scatter solar radiation. They may also either enhance or decrease concentrations of cloud condensation nuclei. This paper summarizes observed concentrations of aerosols in remote continental and marine locations and provides estimates for the sources of organic aerosol matter. The anthropogenic sources of organic aerosols may be as large as the anthropogenic sources of sulfate aerosols, implying a similar magnitude of direct forcing of climate. The source estimates are highly uncertain and subject to revision in the future. A slow secondary source of organic aerosols of unknown origin may contribute to the observed oceanic concentrations. The role of organic aerosols acting as cloud condensation nuclei (CCN) is described and it is concluded that they may either enhance or decrease the ability of anthropogenic sulfate aerosols to act as CCN

  14. Testing Re-entrained Aerosol Kinetic Emissions from Roads : a new approach to infer silt loading on roadways

    Science.gov (United States)

    Kuhns, H.; Etyemezian, V.; Landwehr, D.; MacDougall, C.; Pitchford, M.; Green, M.

    PM 10 and PM 2.5 emissions from roadways are currently estimated using the silt loading on the road surface as a surrogate for the emissions potential of road dust. While the United States Environmental Protection Agency prescribes this method in AP-42, there is considerable cost associated with silt loading measurements; it is feasible to sample only a small portion of a roadway network. A new approach for measuring the concentration of suspendable PM 10 above road surfaces has been developed to obtain a more spatially representative estimate of a road's potential to emit dust. The Testing Re-entrained Aerosols Kinetic Emissions from Roads (TRAKER) system uses real-time aerosol sensors mounted on a vehicle to measure the concentration of dust suspended from the road while the vehicle is in motion. When coupled with a Global Positioning System (GPS) instrument, TRAKER can be used to efficiently survey the changes in suspendable particles due to varying road conditions over a large spatial domain. In a recent study on paved roads in Las Vegas, the TRAKER system was compared with collocated silt loading measurements. The TRAKER system was also used to survey the relative amounts of suspendable road dust on approximately 300 miles of paved roads. The system provides a unique perspective on road dust sources and their spatial distribution. Results of this study indicated that the difference of the PM 10 concentrations measured behind the tire and on the hood is exponentially related to vehicle speed. This was an interesting finding because current AP-42 road dust emissions estimation methods do not include vehicle speed as a factor in the emissions calculations. The experiment also demonstrated that the distribution of suspendable material on roadways is highly variable and that a large number of samples are needed to represent road dust emissions potential on an urban scale for a variety of road and activity conditions.

  15. Radioactive aerosols

    International Nuclear Information System (INIS)

    Chamberlain, A.C.

    1991-01-01

    Radon. Fission product aerosols. Radioiodine. Tritium. Plutonium. Mass transfer of radioactive vapours and aerosols. Studies with radioactive particles and human subjects. Index. This paper explores the environmental and health aspects of radioactive aerosols. Covers radioactive nuclides of potential concern to public health and applications to the study of boundary layer transport. Contains bibliographic references. Suitable for environmental chemistry collections in academic and research libraries

  16. Design requirements for the supercritical water oxidation test bed

    International Nuclear Information System (INIS)

    Svoboda, J.M.; Valentich, D.J.

    1994-05-01

    This report describes the design requirements for the supercritical water oxidation (SCWO) test bed that will be located at the Idaho National Engineering Laboratory (INEL). The test bed will process a maximum of 50 gph of waste plus the required volume of cooling water. The test bed will evaluate the performance of a number of SCWO reactor designs. The goal of the project is to select a reactor that can be scaled up for use in a full-size waste treatment facility to process US Department of Energy mixed wastes. EG ampersand G Idaho, Inc. will design and construct the SCWO test bed at the Water Reactor Research Test Facility (WRRTF), located in the northern region of the INEL. Private industry partners will develop and provide SCWO reactors to interface with the test bed. A number of reactor designs will be tested, including a transpiring wall, tube, and vessel-type reactor. The initial SCWO reactor evaluated will be a transpiring wall design. This design requirements report identifies parameters needed to proceed with preliminary and final design work for the SCWO test bed. A flow sheet and Process and Instrumentation Diagrams define the overall process and conditions of service and delineate equipment, piping, and instrumentation sizes and configuration Codes and standards that govern the safe engineering and design of systems and guidance that locates and interfaces test bed hardware are provided. Detailed technical requirements are addressed for design of piping, valves, instrumentation and control, vessels, tanks, pumps, electrical systems, and structural steel. The approach for conducting the preliminary and final designs and environmental and quality issues influencing the design are provided

  17. Organic aerosol in the summertime southeastern United States: components and their link to volatility distribution, oxidation state and hygroscopicity

    Directory of Open Access Journals (Sweden)

    E. Kostenidou

    2018-04-01

    Full Text Available The volatility distribution of the organic aerosol (OA and its sources during the Southern Oxidant and Aerosol Study (SOAS; Centreville, Alabama was constrained using measurements from an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS and a thermodenuder (TD. Positive matrix factorization (PMF analysis was applied on both the ambient and thermodenuded high-resolution mass spectra, leading to four factors: more oxidized oxygenated OA (MO-OOA, less oxidized oxygenated OA (LO-OOA, an isoprene epoxydiol (IEPOX-related factor (isoprene-OA and biomass burning OA (BBOA. BBOA had the highest mass fraction remaining (MFR at 100 °C, followed by the isoprene-OA, and the LO-OOA. Surprisingly the MO-OOA evaporated the most in the TD. The estimated effective vaporization enthalpies assuming an evaporation coefficient equal to unity were 58 ± 13 kJ mol−1 for the LO-OOA, 89 ± 10 kJ mol−1 for the MO-OOA, 55 ± 11 kJ mol−1 for the BBOA, and 63 ± 15 kJ mol−1 for the isoprene-OA. The estimated volatility distribution of all factors covered a wide range including both semi-volatile and low-volatility components. BBOA had the lowest average volatility of all factors, even though it had the lowest O  :  C ratio among all factors. LO-OOA was the more volatile factor and its high MFR was due to its low enthalpy of vaporization according to the model. The isoprene-OA factor had intermediate volatility, quite higher than suggested by a few other studies. The analysis suggests that deducing the volatility of a factor only from its MFR could lead to erroneous conclusions. The oxygen content of the factors can be combined with their estimated volatility and hygroscopicity to provide a better view of their physical properties.

  18. Identification of secondary aerosol precursors emitted by an aircraft turbofan

    Science.gov (United States)

    Kılıç, Doğuşhan; El Haddad, Imad; Brem, Benjamin T.; Bruns, Emily; Bozetti, Carlo; Corbin, Joel; Durdina, Lukas; Huang, Ru-Jin; Jiang, Jianhui; Klein, Felix; Lavi, Avi; Pieber, Simone M.; Rindlisbacher, Theo; Rudich, Yinon; Slowik, Jay G.; Wang, Jing; Baltensperger, Urs; Prévôt, Andre S. H.

    2018-05-01

    Oxidative processing of aircraft turbine-engine exhausts was studied using a potential aerosol mass (PAM) chamber at different engine loads corresponding to typical flight operations. Measurements were conducted at an engine test cell. Organic gases (OGs) and particle emissions pre- and post-PAM were measured. A suite of instruments, including a proton-transfer-reaction mass spectrometer (PTR-MS) for OGs, a multigas analyzer for CO, CO2, NOx, and an aerosol mass spectrometer (AMS) for nonrefractory particulate matter (NR-PM1) were used. Total aerosol mass was dominated by secondary aerosol formation, which was approximately 2 orders of magnitude higher than the primary aerosol. The chemical composition of both gaseous and particle emissions were also monitored at different engine loads and were thrust-dependent. At idling load (thrust 2.5-7 %), more than 90 % of the secondary particle mass was organic and could mostly be explained by the oxidation of gaseous aromatic species, e.g., benzene; toluene; xylenes; tri-, tetra-, and pentamethyl-benzene; and naphthalene. The oxygenated-aromatics, e.g., phenol, furans, were also included in this aromatic fraction and their oxidation could alone explain up to 25 % of the secondary organic particle mass at idling loads. The organic fraction decreased with thrust level, while the inorganic fraction increased. At an approximated cruise load sulfates comprised 85 % of the total secondary particle mass.

  19. Identification of secondary aerosol precursors emitted by an aircraft turbofan

    Directory of Open Access Journals (Sweden)

    D. Kılıç

    2018-05-01

    Full Text Available Oxidative processing of aircraft turbine-engine exhausts was studied using a potential aerosol mass (PAM chamber at different engine loads corresponding to typical flight operations. Measurements were conducted at an engine test cell. Organic gases (OGs and particle emissions pre- and post-PAM were measured. A suite of instruments, including a proton-transfer-reaction mass spectrometer (PTR-MS for OGs, a multigas analyzer for CO, CO2, NOx, and an aerosol mass spectrometer (AMS for nonrefractory particulate matter (NR-PM1 were used. Total aerosol mass was dominated by secondary aerosol formation, which was approximately 2 orders of magnitude higher than the primary aerosol. The chemical composition of both gaseous and particle emissions were also monitored at different engine loads and were thrust-dependent. At idling load (thrust 2.5–7 %, more than 90 % of the secondary particle mass was organic and could mostly be explained by the oxidation of gaseous aromatic species, e.g., benzene; toluene; xylenes; tri-, tetra-, and pentamethyl-benzene; and naphthalene. The oxygenated-aromatics, e.g., phenol, furans, were also included in this aromatic fraction and their oxidation could alone explain up to 25 % of the secondary organic particle mass at idling loads. The organic fraction decreased with thrust level, while the inorganic fraction increased. At an approximated cruise load sulfates comprised 85 % of the total secondary particle mass.

  20. Fractionation of sulfur isotopes during heterogeneous oxidation of SO2 on sea salt aerosol: a new tool to investigate non-sea salt sulfate production in the marine boundary layer

    Directory of Open Access Journals (Sweden)

    S. Borrmann

    2012-05-01

    Full Text Available The oxidation of SO2 to sulfate on sea salt aerosols in the marine environment is highly important because of its effect on the size distribution of sulfate and the potential for new particle nucleation from H2SO4 (g. However, models of the sulfur cycle are not currently able to account for the complex relationship between particle size, alkalinity, oxidation pathway and rate – which is critical as SO2 oxidation by O3 and Cl catalysis are limited by aerosol alkalinity, whereas oxidation by hypohalous acids and transition metal ions can continue at low pH once alkalinity is titrated. We have measured 34S/32S fractionation factors for SO2 oxidation in sea salt, pure water and NaOCl aerosol, as well as the pH dependency of fractionation. Oxidation of SO2 by NaOCl aerosol was extremely efficient, with a reactive uptake coefficient of ≈0.5, and produced sulfate that was enriched in 32S with αOCl = 0.9882±0.0036 at 19 °C. Oxidation on sea salt aerosol was much less efficient than on NaOCl aerosol, suggesting alkalinity was already exhausted on the short timescale of the experiments. Measurements at pH = 2.1 and 7.2 were used to calculate fractionation factors for each step from SO2(g → multiple steps → SOOCl2−. Oxidation on sea salt aerosol resulted in a lower fractionation factor than expected for oxidation of SO32− by O3 (αseasalt = 1.0124±0.0017 at 19 °C. Comparison of the lower fractionation during oxidation on sea salt aerosol to the fractionation factor for high pH oxidation shows HOCl contributed 29% of S(IV oxidation on sea salt in the short experimental timescale, highlighting the potential importance of hypohalous acids in the marine environment. The sulfur isotope fractionation factors measured in this study allow differentiation between the alkalinity-limited pathways – oxidation by O3 and by Cl catalysis (α34 = 1.0163±0.0018 at 19 °C in pure water or 1.0199±0.0024 at pH = 7.2 – which favour the heavy isotope, and

  1. Fractionation of sulfur isotopes during heterogeneous oxidation of SO2 on sea salt aerosol: a new tool to investigate non-sea salt sulfate production in the marine boundary layer

    Science.gov (United States)

    Harris, E.; Sinha, B.; Hoppe, P.; Foley, S.; Borrmann, S.

    2012-05-01

    The oxidation of SO2 to sulfate on sea salt aerosols in the marine environment is highly important because of its effect on the size distribution of sulfate and the potential for new particle nucleation from H2SO4 (g). However, models of the sulfur cycle are not currently able to account for the complex relationship between particle size, alkalinity, oxidation pathway and rate - which is critical as SO2 oxidation by O3 and Cl catalysis are limited by aerosol alkalinity, whereas oxidation by hypohalous acids and transition metal ions can continue at low pH once alkalinity is titrated. We have measured 34S/32S fractionation factors for SO2 oxidation in sea salt, pure water and NaOCl aerosol, as well as the pH dependency of fractionation. Oxidation of SO2 by NaOCl aerosol was extremely efficient, with a reactive uptake coefficient of ≈0.5, and produced sulfate that was enriched in 32S with αOCl = 0.9882±0.0036 at 19 °C. Oxidation on sea salt aerosol was much less efficient than on NaOCl aerosol, suggesting alkalinity was already exhausted on the short timescale of the experiments. Measurements at pH = 2.1 and 7.2 were used to calculate fractionation factors for each step from SO2(g) → multiple steps → SOOCl2-. Oxidation on sea salt aerosol resulted in a lower fractionation factor than expected for oxidation of SO32- by O3 (αseasalt = 1.0124±0.0017 at 19 °C). Comparison of the lower fractionation during oxidation on sea salt aerosol to the fractionation factor for high pH oxidation shows HOCl contributed 29% of S(IV) oxidation on sea salt in the short experimental timescale, highlighting the potential importance of hypohalous acids in the marine environment. The sulfur isotope fractionation factors measured in this study allow differentiation between the alkalinity-limited pathways - oxidation by O3 and by Cl catalysis (α34 = 1.0163±0.0018 at 19 °C in pure water or 1.0199±0.0024 at pH = 7.2) - which favour the heavy isotope, and the alkalinity non

  2. Atmospheric oxidation of 1,3-butadiene: characterization of gas and aerosol reaction products and implication for PM2.5

    Science.gov (United States)

    Jaoui, M.; Lewandowski, M.; Docherty, K.; Offenberg, J. H.; Kleindienst, T. E.

    2014-06-01

    -phase photooxidation products have also been examined. The contribution of SOA products from 13BD oxidation to ambient PM2.5 was investigated by analyzing a series of ambient PM2.5 samples collected in several locations around the United States. In addition to the occurrence of several organic compounds in field and laboratory samples, glyceric acid, d-threitol, erythritol, erythrose, and threonic acid were found to originate only from the oxidation of 13BD based on our previous experiments involving chamber oxidation of a series of hydrocarbons. Initial attempts have been made to quantify the concentrations of these compounds. The average concentrations of these compounds in ambient PM2.5 samples from the California Research at the Nexus of Air Quality and Climate Change (CalNex) study ranged from 0 to approximately 14.1 ng m-3. The occurrence of several other compounds in both laboratory and field samples suggests that SOA originating from 13BD oxidation could contribute to the ambient aerosol mainly in areas with high 13BD emission rates.

  3. Characterization of organic nitrate constituents of secondary organic aerosol (SOA from nitrate-radical-initiated oxidation of limonene using high-resolution chemical ionization mass spectrometry

    Directory of Open Access Journals (Sweden)

    C. Faxon

    2018-04-01

    Full Text Available The gas-phase nitrate radical (NO3⚫ initiated oxidation of limonene can produce organic nitrate species with varying physical properties. Low-volatility products can contribute to secondary organic aerosol (SOA formation and organic nitrates may serve as a NOx reservoir, which could be especially important in regions with high biogenic emissions. This work presents the measurement results from flow reactor studies on the reaction of NO3⚫ with limonene using a High-Resolution Time-of-Flight Chemical Ionization Mass Spectrometer (HR-ToF-CIMS combined with a Filter Inlet for Gases and AEROsols (FIGAERO. Major condensed-phase species were compared to those in the Master Chemical Mechanism (MCM limonene mechanism, and many non-listed species were identified. The volatility properties of the most prevalent organic nitrates in the produced SOA were determined. Analysis of multiple experiments resulted in the identification of several dominant species (including C10H15NO6, C10H17NO6, C8H11NO6, C10H17NO7, and C9H13NO7 that occurred in the SOA under all conditions considered. Additionally, the formation of dimers was consistently observed and these species resided almost completely in the particle phase. The identities of these species are discussed, and formation mechanisms are proposed. Cluster analysis of the desorption temperatures corresponding to the analyzed particle-phase species yielded at least five distinct groupings based on a combination of molecular weight and desorption profile. Overall, the results indicate that the oxidation of limonene by NO3⚫ produces a complex mixture of highly oxygenated monomer and dimer products that contribute to SOA formation.

  4. Characterization of organic nitrate constituents of secondary organic aerosol (SOA) from nitrate-radical-initiated oxidation of limonene using high-resolution chemical ionization mass spectrometry

    Science.gov (United States)

    Faxon, Cameron; Hammes, Julia; Le Breton, Michael; Kant Pathak, Ravi; Hallquist, Mattias

    2018-04-01

    The gas-phase nitrate radical (NO3⚫) initiated oxidation of limonene can produce organic nitrate species with varying physical properties. Low-volatility products can contribute to secondary organic aerosol (SOA) formation and organic nitrates may serve as a NOx reservoir, which could be especially important in regions with high biogenic emissions. This work presents the measurement results from flow reactor studies on the reaction of NO3⚫ with limonene using a High-Resolution Time-of-Flight Chemical Ionization Mass Spectrometer (HR-ToF-CIMS) combined with a Filter Inlet for Gases and AEROsols (FIGAERO). Major condensed-phase species were compared to those in the Master Chemical Mechanism (MCM) limonene mechanism, and many non-listed species were identified. The volatility properties of the most prevalent organic nitrates in the produced SOA were determined. Analysis of multiple experiments resulted in the identification of several dominant species (including C10H15NO6, C10H17NO6, C8H11NO6, C10H17NO7, and C9H13NO7) that occurred in the SOA under all conditions considered. Additionally, the formation of dimers was consistently observed and these species resided almost completely in the particle phase. The identities of these species are discussed, and formation mechanisms are proposed. Cluster analysis of the desorption temperatures corresponding to the analyzed particle-phase species yielded at least five distinct groupings based on a combination of molecular weight and desorption profile. Overall, the results indicate that the oxidation of limonene by NO3⚫ produces a complex mixture of highly oxygenated monomer and dimer products that contribute to SOA formation.

  5. Standard Test Method for Thermal Oxidative Resistance of Carbon Fibers

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1982-01-01

    1.1 This test method covers the apparatus and procedure for the determination of the weight loss of carbon fibers, exposed to ambient hot air, as a means of characterizing their oxidative resistance. 1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units which are provided for information only and are not considered standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific hazard information, see Section 8.

  6. Assessing the influence of NOx concentrations and relative humidity on secondary organic aerosol yields from α-pinene photo-oxidation through smog chamber experiments and modelling calculations

    Science.gov (United States)

    Stirnweis, Lisa; Marcolli, Claudia; Dommen, Josef; Barmet, Peter; Frege, Carla; Platt, Stephen M.; Bruns, Emily A.; Krapf, Manuel; Slowik, Jay G.; Wolf, Robert; Prévôt, Andre S. H.; Baltensperger, Urs; El-Haddad, Imad

    2017-04-01

    Secondary organic aerosol (SOA) yields from the photo-oxidation of α-pinene were investigated in smog chamber (SC) experiments at low (23-29 %) and high (60-69 %) relative humidity (RH), various NOx / VOC ratios (0.04-3.8) and with different aerosol seed chemical compositions (acidic to neutralized sulfate-containing or hydrophobic organic). A combination of a scanning mobility particle sizer and an Aerodyne high-resolution time-of-flight aerosol mass spectrometer was used to determine SOA mass concentration and chemical composition. We used a Monte Carlo approach to parameterize smog chamber SOA yields as a function of the condensed phase absorptive mass, which includes the sum of OA and the corresponding bound liquid water content. High RH increased SOA yields by up to 6 times (1.5-6.4) compared to low RH. The yields at low NOx / VOC ratios were in general higher compared to yields at high NOx / VOC ratios. This NOx dependence follows the same trend as seen in previous studies for α-pinene SOA. A novel approach of data evaluation using volatility distributions derived from experimental data served as the basis for thermodynamic phase partitioning calculations of model mixtures in this study. These calculations predict liquid-liquid phase separation into organic-rich and electrolyte phases. At low NOx conditions, equilibrium partitioning between the gas and liquid phases can explain most of the increase in SOA yields observed at high RH, when in addition to the α-pinene photo-oxidation products described in the literature, fragmentation products are added to the model mixtures. This increase is driven by both the increase in the absorptive mass and the solution non-ideality described by the compounds' activity coefficients. In contrast, at high NOx, equilibrium partitioning alone could not explain the strong increase in the yields with RH. This suggests that other processes, e.g. reactive uptake of semi-volatile species into the liquid phase, may occur and be

  7. Nuclear aerosol behaviour in LMFBR. Comparison of computer modelling with aerosol experiments

    Energy Technology Data Exchange (ETDEWEB)

    Fermandjian, J [DSN/Centre de Fontenay-aux-Roses, Fontenay-aux-Roses (France)

    1979-03-01

    For the purpose of studying the behaviour of the concentration of aerosols confined in a vessel, various models have been developed, especially in the United States: HAA 3B, HAARM 2 and HAARM 3 - in the Federal Republic of Germany: PARDISEKO 3 and PARDISEKO 3 B - in Japan: ABC 2 and ABC 3 - in the United Kingdom: AEROSIM and in the Netherlands: ETHERDEMO and MADCA. These codes were validated on the basis of tests conducted in vessels whose volumes varied between 0.022 and 850 m{sup 3}. The aerosols studied differed in nature (sodium oxide, fuel oxide, sodium oxide-fuel oxide, gold) and method of production (sodium pool fires, sodium spray fires, arc vaporization, exploding wire) in various atmospheres air, air with variable amounts of oxygen, and nitrogen. This comparison between calculation and experimental results reveals that difficulties still exist, especially as to the selection of the values to be given to some input parameters of the codes (physical data of experimental origin, in particular, the aerosol source function and the characteristics of the size distribution of the emitted particles). Furthermore, the importance of thermophoresis and convection currents has been proved: including the soaring effect in the ABC 3 code enables to fit the experiment. (author)

  8. Nuclear aerosol behaviour in LMFBR. Comparison of computer modelling with aerosol experiments

    International Nuclear Information System (INIS)

    Fermandjian, J.

    1979-01-01

    For the purpose of studying the behaviour of the concentration of aerosols confined in a vessel, various models have been developed, especially in the United States: HAA 3B, HAARM 2 and HAARM 3 - in the Federal Republic of Germany: PARDISEKO 3 and PARDISEKO 3 B - in Japan: ABC 2 and ABC 3 - in the United Kingdom: AEROSIM and in the Netherlands: ETHERDEMO and MADCA. These codes were validated on the basis of tests conducted in vessels whose volumes varied between 0.022 and 850 m 3 . The aerosols studied differed in nature (sodium oxide, fuel oxide, sodium oxide-fuel oxide, gold) and method of production (sodium pool fires, sodium spray fires, arc vaporization, exploding wire) in various atmospheres air, air with variable amounts of oxygen, and nitrogen. This comparison between calculation and experimental results reveals that difficulties still exist, especially as to the selection of the values to be given to some input parameters of the codes (physical data of experimental origin, in particular, the aerosol source function and the characteristics of the size distribution of the emitted particles). Furthermore, the importance of thermophoresis and convection currents has been proved: including the soaring effect in the ABC 3 code enables to fit the experiment. (author)

  9. Respirator Filter Efficiency Testing Against Particulate and Biological Aerosols Under Moderate to High Flow Rates

    Science.gov (United States)

    2006-08-01

    flow rate through the test filter. The flow rate was measured using a mass flow meter (Series 4000, TSI, Shoreview, MN). Several modifications were made...operating conditions. This included assessing the effect of non- isokinetic sampling, flow calibrations, and characterization of the challenge...sampling bias on the measured penetrations due to the non- isokinetic sampling downstream. 3.3.2.2 System Characterization. Shakedown tests were

  10. Real-time measurements of secondary organic aerosol formation and aging from ambient air in an oxidation flow reactor in the Los Angeles area

    Directory of Open Access Journals (Sweden)

    A. M. Ortega

    2016-06-01

    Full Text Available Field studies in polluted areas over the last decade have observed large formation of secondary organic aerosol (SOA that is often poorly captured by models. The study of SOA formation using ambient data is often confounded by the effects of advection, vertical mixing, emissions, and variable degrees of photochemical aging. An oxidation flow reactor (OFR was deployed to study SOA formation in real-time during the California Research at the Nexus of Air Quality and Climate Change (CalNex campaign in Pasadena, CA, in 2010. A high-resolution aerosol mass spectrometer (AMS and a scanning mobility particle sizer (SMPS alternated sampling ambient and reactor-aged air. The reactor produced OH concentrations up to 4 orders of magnitude higher than in ambient air. OH radical concentration was continuously stepped, achieving equivalent atmospheric aging of 0.8 days–6.4 weeks in 3 min of processing every 2 h. Enhancement of organic aerosol (OA from aging showed a maximum net SOA production between 0.8–6 days of aging with net OA mass loss beyond 2 weeks. Reactor SOA mass peaked at night, in the absence of ambient photochemistry and correlated with trimethylbenzene concentrations. Reactor SOA formation was inversely correlated with ambient SOA and Ox, which along with the short-lived volatile organic compound correlation, indicates the importance of very reactive (τOH  ∼  0.3 day SOA precursors (most likely semivolatile and intermediate volatility species, S/IVOCs in the Greater Los Angeles Area. Evolution of the elemental composition in the reactor was similar to trends observed in the atmosphere (O : C vs. H : C slope  ∼  −0.65. Oxidation state of carbon (OSc in reactor SOA increased steeply with age and remained elevated (OSC  ∼  2 at the highest photochemical ages probed. The ratio of OA in the reactor output to excess CO (ΔCO, ambient CO above regional background vs. photochemical age is similar to

  11. Real-time measurements of secondary organic aerosol formation and aging from ambient air in an oxidation flow reactor in the Los Angeles area

    Science.gov (United States)

    Ortega, Amber M.; Hayes, Patrick L.; Peng, Zhe; Palm, Brett B.; Hu, Weiwei; Day, Douglas A.; Li, Rui; Cubison, Michael J.; Brune, William H.; Graus, Martin; Warneke, Carsten; Gilman, Jessica B.; Kuster, William C.; de Gouw, Joost; Gutiérrez-Montes, Cándido; Jimenez, Jose L.

    2016-06-01

    Field studies in polluted areas over the last decade have observed large formation of secondary organic aerosol (SOA) that is often poorly captured by models. The study of SOA formation using ambient data is often confounded by the effects of advection, vertical mixing, emissions, and variable degrees of photochemical aging. An oxidation flow reactor (OFR) was deployed to study SOA formation in real-time during the California Research at the Nexus of Air Quality and Climate Change (CalNex) campaign in Pasadena, CA, in 2010. A high-resolution aerosol mass spectrometer (AMS) and a scanning mobility particle sizer (SMPS) alternated sampling ambient and reactor-aged air. The reactor produced OH concentrations up to 4 orders of magnitude higher than in ambient air. OH radical concentration was continuously stepped, achieving equivalent atmospheric aging of 0.8 days-6.4 weeks in 3 min of processing every 2 h. Enhancement of organic aerosol (OA) from aging showed a maximum net SOA production between 0.8-6 days of aging with net OA mass loss beyond 2 weeks. Reactor SOA mass peaked at night, in the absence of ambient photochemistry and correlated with trimethylbenzene concentrations. Reactor SOA formation was inversely correlated with ambient SOA and Ox, which along with the short-lived volatile organic compound correlation, indicates the importance of very reactive (τOH ˜ 0.3 day) SOA precursors (most likely semivolatile and intermediate volatility species, S/IVOCs) in the Greater Los Angeles Area. Evolution of the elemental composition in the reactor was similar to trends observed in the atmosphere (O : C vs. H : C slope ˜ -0.65). Oxidation state of carbon (OSc) in reactor SOA increased steeply with age and remained elevated (OSC ˜ 2) at the highest photochemical ages probed. The ratio of OA in the reactor output to excess CO (ΔCO, ambient CO above regional background) vs. photochemical age is similar to previous studies at low to moderate ages and also extends to

  12. Plutonium-aerosol emission rates and potential inhalation exposure during cleanup and treatment test at Area 11, Nevada Test Site

    International Nuclear Information System (INIS)

    Shinn, J.H.; Homan, D.N.

    1985-01-01

    A Cleanup and Treatment (CAT) test was conducted in 1981 at Area 11, Nevada Test Site. Its purpose was to evaluate the effectiveness of using a large truck-mounted vacuum cleaner similar to those used to clean paved streets for cleaning radiological contamination from the surface of desert soils. We found that four passes with the vehicle removed 97% of the alpha contamination and reduced resuspension by 99.3 to 99.7%. Potential exposure to cleanup workers was slight when compared to natural background exposure. 7 refs., 1 fig., 2 tabs

  13. Sodium aerosol recovering device

    International Nuclear Information System (INIS)

    Fujimori, Koji; Ueda, Mitsuo; Tanaka, Kazuhisa.

    1997-01-01

    A main body of a recovering device is disposed in a sodium cooled reactor or a sodium cooled test device. Air containing sodium aerosol is sucked into the main body of the recovering device by a recycling fan and introduced to a multi-staged metal mesh filter portion. The air about against each of the metal mesh filters, and the sodium aerosol in the air is collected. The air having a reduced sodium aerosol concentration circulates passing through a recycling fan and pipelines to form a circulation air streams. Sodium aerosol deposited on each of the metal mesh filters is scraped off periodically by a scraper driving device to prevent clogging of each of the metal filters. (I.N.)

  14. Simulating secondary organic aerosol in a regional air quality model using the statistical oxidation model – Part 1: Assessing the influence of constrained multi-generational ageing

    Directory of Open Access Journals (Sweden)

    S. H. Jathar

    2016-02-01

    Full Text Available Multi-generational oxidation of volatile organic compound (VOC oxidation products can significantly alter the mass, chemical composition and properties of secondary organic aerosol (SOA compared to calculations that consider only the first few generations of oxidation reactions. However, the most commonly used state-of-the-science schemes in 3-D regional or global models that account for multi-generational oxidation (1 consider only functionalization reactions but do not consider fragmentation reactions, (2 have not been constrained to experimental data and (3 are added on top of existing parameterizations. The incomplete description of multi-generational oxidation in these models has the potential to bias source apportionment and control calculations for SOA. In this work, we used the statistical oxidation model (SOM of Cappa and Wilson (2012, constrained by experimental laboratory chamber data, to evaluate the regional implications of multi-generational oxidation considering both functionalization and fragmentation reactions. SOM was implemented into the regional University of California at Davis / California Institute of Technology (UCD/CIT air quality model and applied to air quality episodes in California and the eastern USA. The mass, composition and properties of SOA predicted using SOM were compared to SOA predictions generated by a traditional two-product model to fully investigate the impact of explicit and self-consistent accounting of multi-generational oxidation.Results show that SOA mass concentrations predicted by the UCD/CIT-SOM model are very similar to those predicted by a two-product model when both models use parameters that are derived from the same chamber data. Since the two-product model does not explicitly resolve multi-generational oxidation reactions, this finding suggests that the chamber data used to parameterize the models captures the majority of the SOA mass formation from multi-generational oxidation under

  15. Aerosol filtration with metallic fibrous filters

    International Nuclear Information System (INIS)

    Klein, M.; Goossens, W.R.A.

    1983-01-01

    The filtration efficiency of stainless steel fibrous filters (BEKIPOR porous mats and sintered webs) is determined using submicronic monodisperse polystyrene aerosols. Lasers spectrometers are used for the aerosol measurements. The parameters varied are the fiber diameter, the number of layers, the aerosol diameter and the superficial velocity. Two selected types of filters are tested with polydisperse methylene blue aerosols to determine the effect of bed loading on the filter performance and to test washing techniques for the regeneration of the filter

  16. Datasets used in the manuscript titled "Nitrate radicals and biogenic volatile organic compounds: oxidation, mechanisms and organic aerosol"

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset documents that all of the data used in the manuscript "Nitrate radicals and biogenic volatile organic compounds: oxidation, mechanisms, and organic...

  17. The clearance of Pu and Am from the respiratory system of rodents after the inhalation of oxide aerosols of these actinides either alone or in combination with other metals

    International Nuclear Information System (INIS)

    Stather, J.W.; James, A.C.; Brightwell, J.; Rodwell, P.

    1979-01-01

    In this series of studies in rodents the lung clearance and tissue distribution of both plutonium and americium have been measured following their inhalation as mixed actinide oxides either alone or in combination with other metals. The aerosols used were materials to which workers in the nuclear industry may be occupationally exposed or which could be generated in the event of an accident in a reactor core or fuel fabrication plant. The studies showed that, at least for some PuO 2 aerosols, the lung model currently being used by ICRP for estimating tissue doses from inhaled actinides may overestimate, by about a factor of ten, the amount of plutonium translocated to the blood. The presence of oxides of other metals can, however, appreciably influence the clearance of plutonium from the lung. While in some mixtures plutonium dioxide behaves as an insoluble (Class Y) compound and in others as a soluble (Class W) compound, it may also have transportability characteristics between these two extremes. Americium-241 behaves as a soluble (Class W) compound when inhaled as the oxide. However, if it is present in trace quantities in mixed-oxide aerosols its behaviour depends upon that of the materials present in greatest mass. (author)

  18. Development and first application of an Aerosol Collection Module (ACM) for quasi online compound specific aerosol measurements

    Science.gov (United States)

    Hohaus, Thorsten; Kiendler-Scharr, Astrid; Trimborn, Dagmar; Jayne, John; Wahner, Andreas; Worsnop, Doug

    2010-05-01

    Atmospheric aerosols influence climate and human health on regional and global scales (IPCC, 2007). In many environments organics are a major fraction of the aerosol influencing its properties. Due to the huge variety of organic compounds present in atmospheric aerosol current measurement techniques are far from providing a full speciation of organic aerosol (Hallquist et al., 2009). The development of new techniques for compound specific measurements with high time resolution is a timely issue in organic aerosol research. Here we present first laboratory characterisations of an aerosol collection module (ACM) which was developed to allow for the sampling and transfer of atmospheric PM1 aerosol. The system consists of an aerodynamic lens system focussing particles on a beam. This beam is directed to a 3.4 mm in diameter surface which is cooled to -30 °C with liquid nitrogen. After collection the aerosol sample can be evaporated from the surface by heating it to up to 270 °C. The sample is transferred through a 60cm long line with a carrier gas. In order to test the ACM for linearity and sensitivity we combined it with a GC-MS system. The tests were performed with octadecane aerosol. The octadecane mass as measured with the ACM-GC-MS was compared versus the mass as calculated from SMPS derived total volume. The data correlate well (R2 0.99, slope of linear fit 1.1) indicating 100 % collection efficiency. From 150 °C to 270 °C no effect of desorption temperature on transfer efficiency could be observed. The ACM-GC-MS system was proven to be linear over the mass range 2-100 ng and has a detection limit of ~ 2 ng. First experiments applying the ACM-GC-MS system were conducted at the Jülich Aerosol Chamber. Secondary organic aerosol (SOA) was formed from ozonolysis of 600 ppbv of b-pinene. The major oxidation product nopinone was detected in the aerosol and could be shown to decrease from 2 % of the total aerosol to 0.5 % of the aerosol over the 48 hours of

  19. Frequency analysis of pulmonary tumors occurrence at the rat after exposure to actinide oxide aerosols. Risk factors identification by comparing NpO2 and PuO2

    International Nuclear Information System (INIS)

    Dudoignon, N.

    2001-07-01

    Inhalation of actinide oxide particles is potentially one route of contamination of workers, which might induce pulmonary tumours due to aerosol generation during nuclear fuel fabrication process. Dose-effect relationships for lung tumour induction have been well established from epidemiological and experimental studies. However, they do not take into account specific parameters of exposure. The aim of this study was to compare cancer incidence among groups of rats exposed either to NpO 2 or to PuO 2 , two actinide oxides with different specific activity, but with similar aerosol granulometry. During the rat life-span, lung tumour development could occur and the individual follow-up allowed the determination of lung dose at death. Although aerosol particle sizes were similar, the mean number of particles per unit of activity was 2400 times higher for NpO 2 as compared to PuO 2 . This range of variation appeared higher than the variation of specific activity (450). Initial distribution of aerosol was then much more homogeneous for neptunium. In the range of initial lung deposits studied, the only physiological changes observed concerned lung clearance and rat life- span after exposure to the highest levels of Np activity. Pathological examination performed at death showed that carcinogenic power of neptunium was 2 to 3 times higher than that of plutonium. Dose-effect relationships appeared linear and when compared to previous studies, showed an increase of lung cancer risk as the specific activity of the inhaled actinide oxide decreases. The range of risk variation can reach a factor of 10, revealing that the consideration of lung dose at death solely might not be sufficient for an accurate estimate of risk and that specific parameters of exposure, such as nature and granulometry of aerosols, should also be taken into account. (author)

  20. Standard test methods for analysis of sintered gadolinium oxide-uranium dioxide pellets

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 These test methods cover procedures for the analysis of sintered gadolinium oxide-uranium dioxide pellets to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Section Carbon (Total) by Direct CombustionThermal Conductivity Method C1408 Test Method for Carbon (Total) in Uranium Oxide Powders and Pellets By Direct Combustion-Infrared Detection Method Chlorine and Fluorine by Pyrohydrolysis Ion-Selective Electrode Method C1502 Test Method for Determination of Total Chlorine and Fluorine in Uranium Dioxide and Gadolinium Oxide Gadolinia Content by Energy-Dispersive X-Ray Spectrometry C1456 Test Method for Determination of Uranium or Gadolinium, or Both, in Gadolinium Oxide-Uranium Oxide Pellets or by X-Ray Fluorescence (XRF) Hydrogen by Inert Gas Fusion C1457 Test Method for Determination of Total Hydrogen Content of Uranium Oxide Powders and Pellets by Carrier Gas Extraction Isotopic Uranium Composition by Multiple-Filament Surface-Ioni...

  1. In vitro tests for aerosol deposition II: IVIVCs for different dry powder inhalers in normal adults.

    Science.gov (United States)

    Delvadia, Renishkumar; Hindle, Michael; Longest, P Worth; Byron, Peter R

    2013-06-01

    A new in vitro test method for dry powder inhalers (DPIs) was recently found to be predictive of the published in vivo results for Budelin Novolizer. The present study was intended to assess the method's robustness by evaluating correlations between average drug deposition in vitro and in vivo from five different DPIs. In vitro drug deposition from five marketed DPIs was assessed in a realistic physical airway model of a "medium" sized adult in an experimental setup that allowed deposition to be characterized regionally for carefully selected simulated air flow rate versus time profiles. The DPIs studied were Spiriva(®) HandiHaler(®), Relenza(®) Diskhaler(®), Salbutamol Easyhaler(®), Pulmicort(®) Turbuhaler(®), and Foradil(®) Aerolizer(®). In vitro regional deposition results were compared with those reported in the literature in order to create in vitro-in vivo correlations (IVIVCs) for each inhaler. Mean percent total lung deposition (TLD ± SD) in vitro for Spiriva HandiHaler, Relenza Diskhaler, Salbutamol Easyhaler, Pulmicort Turbuhaler, and Foradil Aerolizer were 17.3 ± 1.2, 22.6 ± 1.1, 29.0 ± 1.1, 28.0 ± 3.0, and 21.7 ± 1.2, respectively. These results showed excellent agreement with reported in vivo values, with absolute prediction errors in TLD of ≤ 2% for all DPIs except Relenza Diskhaler. Similarly, in vitro mouth-throat and device deposition results were stoichiometrically comparable to those reported in vivo for all DPIs except Relenza Diskhaler and Turbuhaler. Inspection of the scintigraphy studies for Relenza Diskhaler and Turbohaler revealed possible problems with powder labeling and result interpretation in their in vivo clinical assessments. A characteristic physical airway model representing a medium-sized adult, when coupled to carefully chosen characteristic inhalation maneuvers used in the clinic, produced results that correlated with regional drug deposition estimates from scintigraphy across a group of different DPIs.

  2. Aqueous Photochemistry of Secondary Organic Aerosol of α-Pinene and α-Humulene Oxidized with Ozone, Hydroxyl Radical, and Nitrate Radical

    Energy Technology Data Exchange (ETDEWEB)

    Romonosky, Dian E.; Li, Ying; Shiraiwa, Manabu; Laskin, Alexander; Laskin, Julia; Nizkorodov, Sergey

    2017-01-18

    Formation of secondary organic aerosols (SOA) from biogenic volatile organic compounds 13 (BVOC) occurs via O3- and OH-initiated reactions during the day and reactions with NO3 during the 14 night. We explored the effect of these three oxidation conditions on the molecular composition and 15 aqueous photochemistry of model SOA prepared from two common BVOC. A common monoterpene, α- 16 pinene, and sesquiterpene, α-humulene, were used to form SOA in a smog chamber via BVOC + O3, 17 BVOC + NO3, and BVOC + OH + NOx oxidation. Samples of SOA were collected, extracted in water, 18 and photolyzed in an aqueous solution in order to simulate the photochemical cloud processing of SOA. 19 The extent of change in the molecular level composition of SOA over 4 hours of photolysis (roughly 20 equivalent to 64 hours of photolysis under ambient conditions) was assessed with high-resolution 21 electrospray ionization mass spectrometry. The analysis revealed significant differences in the molecular 22 composition between monoterpene and sesquiterpene SOA formed by the different oxidation pathways. 23 The composition further evolved during photolysis with the most notable change corresponding to the 24 nearly-complete removal of nitrogen-containing organic compounds. Hydrolysis of SOA compounds also 25 occurred in parallel with photolysis. The preferential loss of larger SOA compounds during photolysis 26 and hydrolysis made the SOA compounds more volatile on average. This study suggests that cloud- and 27 fog-processing may under certain conditions lead to a reduction in the SOA loading as opposed to an 28 increase in SOA loading commonly assumed in the literature.

  3. Stratospheric aerosols

    International Nuclear Information System (INIS)

    Rosen, J.; Ivanov, V.A.

    1993-01-01

    Stratospheric aerosol measurements can provide both spatial and temporal data of sufficient resolution to be of use in climate models. Relatively recent results from a wide range of instrument techniques for measuring stratospheric aerosol parameters are described. Such techniques include impactor sampling, lidar system sensing, filter sampling, photoelectric particle counting, satellite extinction-sensing using the sun as a source, and optical depth probing, at sites mainly removed from tropospheric aerosol sources. Some of these techniques have also had correlative and intercomparison studies. The main methods for determining the vertical profiles of stratospheric aerosols are outlined: lidar extinction measurements from satellites; impactor measurements from balloons and aircraft; and photoelectric particle counter measurements from balloons, aircraft, and rockets. The conversion of the lidar backscatter to stratospheric aerosol mass loading is referred to. Absolute measurements of total solar extinction from satellite orbits can be used to extract the aerosol extinction, and several examples of vertical profiles of extinction obtained with the SAGE satellite are given. Stratospheric mass loading can be inferred from extinction using approximate linear relationships but under restrictive conditions. Impactor sampling is essentially the only method in which the physical nature of the stratospheric aerosol is observed visually. Vertical profiles of stratospheric aerosol number concentration using impactor data are presented. Typical profiles using a dual-size-range photoelectric dustsonde particle counter are given for volcanically disturbed and inactive periods. Some measurements of the global distribution of stratospheric aerosols are also presented. Volatility measurements are described, indicating that stratospheric aerosols are composed primarily of about 75% sulfuric acid and 25% water

  4. In-pile test of tritium recovery from lithium oxide

    International Nuclear Information System (INIS)

    Kurasawa, Toshimasa; Yoshida, Hiroshi; Watanabe, Hitoshi; Takeshita, Hidefumi; Miyauchi, Takejiro; Matsui, Tomoaki

    1984-05-01

    In-situ tritium recovery experiment with sintered lithium oxide pellets was performed under a high neutron fluence in the JRR-2. The irradiation hole VT-10 is the vertical one in the fuel rods region of the reactor, and the neutron flux is as follows: the thermal neutron flux with the epithermal neutron; 1.12 x 10 14 n/cm 2 . sec, the fast neutron flux; 1.0 x 10 12 n/cm 2 . sec. Irradiation material is the four pellets of cylindrical Li 2 O with the size of 11mm-OD, 1.8mm-ID, 10mm-H, and their total weight is 6.67g(the apparent bulk density 86%TD). A sweep gas capsule with a inner heater was constructed for the present study. Irradiation temperatures were regulated in the high temperature range, 470 -- 760 0 C. Four cycles of irradiation tests were carried out from May to August in 1983, and the effective thermal neutron fluence and the burnup of 6 Li were 5.9 x 10 19 nvt and 0.24% of total lithium(natural abundance of Li), respectively. The amount of generated tritium was calculated to be 31.2Ci by using a value of the depression factor of the thermal neutron flux(0.148) and the effective neutron cross section(543b) for the 6 Li(n, α) 3 H reaction. Present report describes the tritium release behavior in the in-situ tritium recovery apparatus and discuss the effects of the moisture, the hydrogen spiking, the irradiation temperature, etc.. Problems relative to a real time measurement of a comparatively high tritium concentration(10 -1 -- 10 2 μCi/cm 3 ) in the helium gas stream were also investigated. (author)

  5. On-site test of filters in nuclear facilities using radioactive sodium chloride (24Na)-aerosol and methyl iodide (131I)

    International Nuclear Information System (INIS)

    Heidam, N.Z.; Hansen, K.A.; Fenger, J.; Flyger, H.; Hedemann Jensen, P.

    1986-02-01

    The nuclar facilities at Risoe National Laboratory are equipped with high-efficiency filters to protect the environment from routine or accidental releases of radioactive material. The filter efficiency must be tested regularly and a method for on-site control is described. It is based on injection of a radioactive sample in the filter duct, followed by sampling before and after the filter. HEPA-filters are tested with a 24 NaCl-aerosol and charcoal filters with 131 ICH 3 . Normally samples of 1 mCi are used. Penetrations (1 - efficiency) can be determined with a relative uncertainty of 10-15%. (author)

  6. Plutonium-aerosol emission rates and human pulmonary deposition calculations for Nuclear Site 201, Nevada Test Site

    International Nuclear Information System (INIS)

    Shinn, J.H.; Homan, D.N.

    1982-01-01

    This study determined the plutonium-aerosol fluxes from the soil to quantify (1) the extent of potential human exposure by deep-lung retention of alpha-emitting particles; (2) the source term should there be any significant, long-term, transport of plutonium aerosols; and (3) the resuspension factor and rate so that, for the first time at any nuclear site, one may calculate how long it will take for wind erosion to carry away a significant amount of the contaminated soil. High-volume air samplers and cascade impactors were used to characterize the plutonium aerosols. Meteorological flux-profile methods were used to calculate dust and plutonium aerosol emission rates. A floorless wind tunnel (10-m long) was used to examine resuspension under steady-state, high wind speed. The resuspension factor was two orders of magnitude lower than the other comparable sites at NTS and elsewhere, and the average resuspension rate of 5.3 x 10 -8 /d was also very low, so that the half-time for resuspension by wind erosion was about 36,000 y

  7. Aging Depth Test of Rubber Blocks by Accelerated Thermal Oxidation Test

    International Nuclear Information System (INIS)

    Park, Junhee; Choun, Young-Sun; Kim, Min Kyu

    2015-01-01

    In this study, the accelerated thermal oxidation tests of rubber block were performed to investigate the aging depth of rubber bearing. From the tests, it was found the critical aging depth in rubber block. Also the property variation of rubber was investigated along the depth. The deterioration pattern from the aging depth tests was found from surface to inside and the critical aging depth was to be about 10 mm. The analytical model for rubber bearing with aging can be developed based on the relationship between the property variation and aging depth investigated from this study. The mechanical properties of rubber bearings were changed with time. Because the aging effect of rubber material was generally higher than that of other structure materials it is needed that the aging properties of seismically isolators should be evaluated to ensure the safety of seismically isolated nuclear power plants (NPPs) over the lifetime. NRC and ASCE required the tests of seismically isolators for investigating the aging properties. JNES also required the seismic response analysis for the seismically isolated NPPs when the properties of seismically isolators were extremely changed. If the aging properties of seismically isolators such as rubber bearings are evaluated by analysis the analytical model of seismically isolators should be developed considering aging effect of rubber material. From the previous research, it was reported that the behavior of aged rubber material mainly affected by temperature and oxidation. The material properties between surface and inside can be different by the oxidation of rubber. Therefore, the aging depth should be investigated for exactly evaluating the seismic behavior of aged rubber bearing. The aging depth of rubber baring was not influenced by the size of seismically isolators but environment condition. Therefore, the detail analysis considering aging depth was not required for NPPs with large seismically isolators. But the seismic response

  8. Ozonolysis and Subsequent Photolysis of unsaturated organic molecules: Model Systems for Photochemical Aging of Organic Aerosol Particles

    Science.gov (United States)

    Park, J.; Gomez, A. L.; Walser, M. L.; Lin, A.; Nizkorodov, S. A.

    2005-12-01

    Chemical and photochemical aging of organic species adsorbed on aerosol particle surfaces is believed to have a significant effect on cloud condensation properties of atmospheric aerosols. Ozone initiated oxidation reactions of thin films of undecylenic acid and alkene-terminated self assembled monolayers (SAMs) on SiO2 surface were investigated using a combination of spectroscopic and mass spectrometric techniques. Photolysis of the oxidized film in the tropospheric actinic region (λ>290 nm) readily produces formaldehyde and formic acid as gas-phase products. Photodissociation action spectra of the oxidized film suggest that organic peroxides are responsible for the enhanced photochemical activity. The presence of peroxides in the oxidized sample was confirmed by mass-spectrometric analysis and by an iodometric test. Significant polymerization resulting from secondary reactions of Criegee radicals during ozonolysis of the film is also observed. The reaction mechanism and its implications for photochemical aging of atmospheric aerosol particles will be discussed.

  9. Intercomparison of OH and OH reactivity measurements in a high isoprene and low NO environment during the Southern Oxidant and Aerosol Study (SOAS)

    Science.gov (United States)

    Sanchez, Dianne; Jeong, Daun; Seco, Roger; Wrangham, Ian; Park, Jeong-Hoo; Brune, William H.; Koss, Abigail; Gilman, Jessica; de Gouw, Joost; Misztal, Pawel; Goldstein, Allen; Baumann, Karsten; Wennberg, Paul O.; Keutsch, Frank N.; Guenther, Alex; Kim, Saewung

    2018-02-01

    We intercompare OH and OH reactivity datasets from two different techniques, chemical ionization mass spectrometry (CIMS) and laser-induced fluorescence (LIF) in a high isoprene and low NO environment in a southeastern US forest during the Southern Oxidant and Aerosol Study (SOAS). An LIF instrument measured OH and OH reactivity at the top of a tower, a CIMS instrument measured OH at the top of the tower, and a CIMS based comparative reactivity method (CRM-CIMS) instrument deployed at the base of the tower measured OH reactivity. Averaged diel variations of OH and OH reactivity from these datasets agree within analytical uncertainty and correlations of LIF versus CIMS for OH and OH reactivity have slopes of 0.65 and 0.97, respectively. However, there are systematic differences between the measurement datasets. The CRM-CIMS measurements of OH reactivity were ∼16% lower than those by the LIF technique in the late afternoon. We speculate that it is caused by losses in the sampling line down to the CRM-CIMS instrument. On the other hand, we could not come up with a reasonable explanation for the difference in the LIF and CIMS OH datasets for early morning and late afternoon when OH is below 1 × 106 molecules cm-3. Nonetheless, results of this intercomparison exercise strengthen previous publications from the field site on OH concentrations and atmospheric reactivity.

  10. Chemical Characterization and Reactivity Testing of Fuel-Oxidizer Reaction Product (Test Report)

    Science.gov (United States)

    1996-01-01

    The product of incomplete reaction of monomethylhydrazine (MMH) and nitrogen tetroxide (NTO) propellants, or fuel-oxidizer reaction product (FORP), has been hypothesized as a contributory cause of an anomaly which occurred in the chamber pressure (PC) transducer tube on the Reaction Control Subsystem (RCS) aft thruster 467 on flight STS-51. A small hole was found in the titanium-alloy PC tube at the first bend below the pressure transducer. It was surmised that the hole may have been caused by heat and pressure resulting from ignition of FORP. The NASA Johnson Space Center (JSC) White Sands Test Facility (WSTF) was requested to define the chemical characteristics of FORP, characterize its reactivity, and simulate the events in a controlled environment which may have lead to the Pc-tube failure. Samples of FORP were obtained from the gas-phase reaction of MMH with NTO under laboratory conditions, the pulsed firings of RCS thrusters with modified PC tubes using varied oxidizer or fuel lead times, and the nominal RCS thruster firings at WSTF and Kaiser-Marquardt. Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), accelerating rate calorimetry (ARC), ion chromatography (IC), inductively coupled plasma (ICP) spectrometry, thermogravimetric analysis (TGA) coupled to FTIR (TGA/FTIR), and mechanical impact testing were used to qualitatively and quantitatively characterize the chemical, thermal, and ignition properties of FORP. These studies showed that the composition of FORP is variable but falls within a limited range of compositions that depends on the fuel loxidizer ratio at the time of formation, composition of the post-formation atmosphere (reducing or oxidizing), and reaction or postreaction temperature. A typical composition contains methylhydrazinium nitrate (MMHN), ammonium nitrate (AN), methylammonium nitrate (MAN), and trace amounts of hydrazinium nitrate and 1,1-dimethylhydrazinium nitrate. The thermal decomposition

  11. Effect of oxidant concentration, exposure time, and seed particles on secondary organic aerosol chemical composition and yield

    Directory of Open Access Journals (Sweden)

    A. T. Lambe

    2015-03-01

    This similarity in turn suggests that both in the flow reactor and in chambers, SOA chemical composition at low OH exposure is governed primarily by gas-phase OH oxidation of the precursors rather than heterogeneous oxidation of the condensed particles. In general, SOA yields measured in the flow reactor are lower than measured in chambers for the range of equivalent OH exposures that can be measured in both the flow reactor and chambers. The influence of sulfate seed particles on isoprene SOA yield measurements was examined in the flow reactor. The studies show that seed particles increase the yield of SOA produced in flow reactors by a factor of 3 to 5 and may also account in part for higher SOA yields obtained in the chambers, where seed particles are routinely used.

  12. Mechanical test of E110 cladding material oxidized in hydrogen rich steam atmosphere

    International Nuclear Information System (INIS)

    Windberg, P.; Perez-Fero, E.

    2005-01-01

    The behavior of the fuel cladding under accidental conditions has been studied at the AEKI for more than a decade. Earlier, the effect of oxygen and hydrogen content on the mechanical properties was studied separately. The present experiments can help to understand what kind of processes took place in the cleaning tank at Paks NPP (2003). The purpose of our experiments was to investigate high temperature oxidation of E110 cladding in steam + hydrogen mixture. A high temperature tube furnace was used for oxidation of the samples. The oxidation was carried out at three different temperatures (900 0 C, 1000 0 C, 1100 0 C). The hydrogen content in the steam was varied between 19-36 vol%. The oxygen content of the sample was defined as oxidation ratio. Two sizes (length: 2 and 8 mm) of cladding rings and 100 mm long E110 cladding tubes were oxidized. After the oxidation we made compression and tensile tests for rings, and ballooning experiments for 100 mm long tube. The most important conclusions were the following. Oxidation in H-rich steam atmosphere need longer time to get the same oxidation ratio compared to the steam oxidation without hydrogen. The shorter oxidation time results in a more compact oxide layer. The longer oxidation time leads to a cracked oxide layer. (author)

  13. Testing of an automated online EA-IRMS method for fast and simultaneous carbon content and stable isotope measurement of aerosol samples

    Science.gov (United States)

    Major, István; Gyökös, Brigitta; Túri, Marianna; Futó, István; Filep, Ágnes; Hoffer, András; Molnár, Mihály

    2016-04-01

    Comprehensive atmospheric studies have demonstrated that carbonaceous aerosol is one of the main components of atmospheric particulate matter over Europe. Various methods, considering optical or thermal properties, have been developed for quantification of the accurate amount of both organic and elemental carbon constituents of atmospheric aerosol. The aim of our work was to develop an alternative fast and easy method for determination of the total carbon content of individual aerosol samples collected on prebaked quartz filters whereby the mass and surface concentration becomes simply computable. We applied the conventional "elemental analyzer (EA) coupled online with an isotope ratio mass spectrometer (IRMS)" technique which is ubiquitously used in mass spectrometry. Using this technique we are able to measure simultaneously the carbon stable isotope ratio of the samples, as well. During the developing process, we compared the EA-IRMS technique with an off-line catalytic combustion method worked out previously at Hertelendi Laboratory of Environmental Studies (HEKAL). We tested the combined online total carbon content and stable isotope ratio measurement both on standard materials and real aerosol samples. Regarding the test results the novel method assures, on the one hand, at least 95% of carbon recovery yield in a broad total carbon mass range (between 100 and 3000 ug) and, on the other hand, a good reproducibility of stable isotope measurements with an uncertainty of ± 0.2 per mill. Comparing the total carbon results obtained by the EA-IRMS and the off-line catalytic combustion method we found a very good correlation (R2=0.94) that proves the applicability of both preparation method. Advantages of the novel method are the fast and simplified sample preparation steps and the fully automated, simultaneous carbon stable isotope ratio measurement processes. Furthermore stable isotope ratio results can effectively be applied in the source apportionment

  14. The impact of mouse passaging of Mycobacterium tuberculosis strains prior to virulence testing in the mouse and guinea pig aerosol models.

    Directory of Open Access Journals (Sweden)

    Paul J Converse

    2010-04-01

    Full Text Available It has been hypothesized that the virulence of lab-passaged Mycobacterium tuberculosis and recombinant M. tuberculosis mutants might be reduced due to multiple in vitro passages, and that virulence might be augmented by passage of these strains through mice before quantitative virulence testing in the mouse or guinea pig aerosol models.By testing three M. tuberculosis H37Rv samples, one deletion mutant, and one recent clinical isolate for survival by the quantitative organ CFU counting method in mouse or guinea pig aerosol or intravenous infection models, we could discern no increase in bacterial fitness as a result of passaging of M. tuberculosis strains in mice prior to quantitative virulence testing in two animal models. Surface lipid expression as assessed by neutral red staining and thin-layer chromatography for PDIM analysis also failed to identify virulence correlates.These results indicate that animal passaging of M. tuberculosis strains prior to quantitative virulence testing in mouse or guinea pig models does not enhance or restore potency to strains that may have lost virulence due to in vitro passaging. It is critical to verify virulence of parental strains before genetic manipulations are undertaken and comparisons are made.

  15. Final Report: Part 1. In-Place Filter Testing Instrument for Nuclear Material Containers. Part 2. Canister Filter Test Standards for Aerosol Capture Rates.

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Austin Douglas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Runnels, Joel T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Moore, Murray E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Reeves, Kirk Patrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-11-02

    A portable instrument has been developed to assess the functionality of filter sand o-rings on nuclear material storage canisters, without requiring removal of the canister lid. Additionally, a set of fifteen filter standards were procured for verifying aerosol leakage and pressure drop measurements in the Los Alamos Filter Test System. The US Department of Energy uses several thousand canisters for storing nuclear material in different chemical and physical forms. Specialized filters are installed into canister lids to allow gases to escape, and to maintain an internal ambient pressure while containing radioactive contaminants. Diagnosing the condition of container filters and canister integrity is important to ensure worker and public safety and for determining the handling requirements of legacy apparatus. This report describes the In-Place-Filter-Tester, the Instrument Development Plan and the Instrument Operating Method that were developed at the Los Alamos National Laboratory to determine the “as found” condition of unopened storage canisters. The Instrument Operating Method provides instructions for future evaluations of as-found canisters packaged with nuclear material. Customized stainless steel canister interfaces were developed for pressure-port access and to apply a suction clamping force for the interface. These are compatible with selected Hagan-style and SAVY-4000 storage canisters that were purchased from NFT (Nuclear Filter Technology, Golden, CO). Two instruments were developed for this effort: an initial Los Alamos POC (Proof-of-Concept) unit and the final Los Alamos IPFT system. The Los Alamos POC was used to create the Instrument Development Plan: (1) to determine the air flow and pressure characteristics associated with canister filter clogging, and (2) to test simulated configurations that mimicked canister leakage paths. The canister leakage scenarios included quantifying: (A) air leakage due to foreign material (i.e. dust and hair

  16. Test of Mie-based single-scattering properties of non-spherical dust aerosols in radiative flux calculations

    International Nuclear Information System (INIS)

    Fu, Q.; Thorsen, T.J.; Su, J.; Ge, J.M.; Huang, J.P.

    2009-01-01

    We simulate the single-scattering properties (SSPs) of dust aerosols with both spheroidal and spherical shapes at a wavelength of 0.55 μm for two refractive indices and four effective radii. Herein spheres are defined by preserving both projected area and volume of a non-spherical particle. It is shown that the relative errors of the spheres to approximate the spheroids are less than 1% in the extinction efficiency and single-scattering albedo, and less than 2% in the asymmetry factor. It is found that the scattering phase function of spheres agrees with spheroids better than the Henyey-Greenstein (HG) function for the scattering angle range of 0-90 o . In the range of ∼90-180 o , the HG function is systematically smaller than the spheroidal scattering phase function while the spherical scattering phase function is smaller from ∼90 o to 145 o but larger from ∼145 o to 180 o . We examine the errors in reflectivity and absorptivity due to the use of SSPs of equivalent spheres and HG functions for dust aerosols. The reference calculation is based on the delta-DISORT-256-stream scheme using the SSPs of the spheroids. It is found that the errors are mainly caused by the use of the HG function instead of the SSPs for spheres. By examining the errors associated with the delta-four- and delta-two-stream schemes using various approximate SSPs of dust aerosols, we find that the errors related to the HG function dominate in the delta-four-stream results, while the errors related to the radiative transfer scheme dominate in the delta-two-stream calculations. We show that the relative errors in the global reflectivity due to the use of sphere SSPs are always less than 5%. We conclude that Mie-based SSPs of non-spherical dust aerosols are well suited in radiative flux calculations.

  17. Bonding to oxide ceramics—laboratory testing versus clinical outcome.

    Science.gov (United States)

    Kern, Matthias

    2015-01-01

    Despite a huge number of published laboratory bonding studies on dental oxide ceramics clinical long-term studies on resin bonded oxide ceramic restorations are rare. The purpose of this review is to present the best available clinical evidence for successful bonding of dental oxide ceramic restorations. Clinical trials with resin-bonded restorations that had no or only limited mechanical retention and were made from alumina or zirconia ceramic were identified using an electronic search in PubMed database. Overall 10 publications with clinical trials could be identified. Their clinical outcome was compared with that laboratory bond strength studies. Clinical data provide strong evidence that air-abrasion at a moderate pressure in combination with using phosphate monomer containing primers and/or luting resins provide long-term durable bonding to glass-infiltrated alumina and zirconia ceramic under the humid and stressful oral conditions. As simple and clinically reliable bonding methods to oxide ceramics exist, the rationale for development of alternative bonding methods might be reconsidered especially when these methods are more time consuming or require rather complicated and/or technique sensitive procedures. Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  18. Concentration Impedance in Testing of Solid Oxide Cells Revisited

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Ebbesen, Sune Dalgaard; Jensen, Søren Højgaard

    2017-01-01

    The concentration impedance originating from diffusion and reactant conversion impedance of the Ni-YSZ supported fuel electrode in solid oxide cell has been treated many times during the latest couple of decades. In spite of this, the separation of the diffusion impedance from the conversion...

  19. Organic aerosol formation during the atmospheric degradation of toluene.

    Science.gov (United States)

    Hurley, M D; Sokolov, O; Wallington, T J; Takekawa, H; Karasawa, M; Klotz, B; Barnes, I; Becker, K H

    2001-04-01

    Organic aerosol formation during the atmospheric oxidation of toluene was investigated using smog chamber systems. Toluene oxidation was initiated by the UV irradiation of either toluene/air/NOx or toluene/air/CH3ONO/NO mixtures. Aerosol formation was monitored using scanning mobility particle sizers and toluene loss was monitored by in-situ FTIR spectroscopy or GC-FID techniques. The experimental results show that the reaction of OH radicals, NO3 radicals and/or ozone with the first generation products of toluene oxidation are sources of organic aerosol during the atmospheric oxidation of toluene. The aerosol results fall into two groups, aerosol formed in the absence and presence of ozone. An analytical expression for aerosol formation is developed and values are obtained for the yield of the aerosol species. In the absence of ozone the aerosol yield, defined as aerosol formed per unit toluene consumed once a threshold for aerosol formation has been exceeded, is 0.075 +/- 0.004. In the presence of ozone the aerosol yield is 0.108 +/- 0.004. This work provides experimental evidence and a simple theory confirming the formation of aerosol from secondary reactions.

  20. Secondary organic aerosol formation from primary aliphatic amines with NO3 radical

    Science.gov (United States)

    Malloy, Q. G. J.; Qi, Li; Warren, B.; Cocker, D. R., III; Erupe, M. E.; Silva, P. J.

    2009-03-01

    Primary aliphatic amines are an important class of nitrogen containing compounds emitted from automobiles, waste treatment facilities and agricultural animal operations. A series of experiments conducted at the UC-Riverside/CE-CERT Environmental Chamber is presented in which oxidation of methylamine, ethylamine, propylamine, and butylamine with O3 and NO3 have been investigated. Very little aerosol formation is observed in the presence of O3 only. However, after addition of NO, and by extension NO3, large aerosol mass yields (~44% for butylamine) are seen. Aerosol generated was determined to be organic in nature due to the small fraction of NO and NO2 in the total signal (tested) as detected by an aerosol mass spectrometer (AMS). We propose a reaction mechanism between carbonyl containing species and the parent amine leading to formation of particulate imine products. These findings can have significant impacts on rural communities with elevated nighttime PM loadings, when significant levels of NO3 exist.

  1. The composition and variability of atmospheric aerosol over Southeast Asia during 2008

    Directory of Open Access Journals (Sweden)

    W. Trivitayanurak

    2012-01-01

    Full Text Available We use a nested version of the GEOS-Chem global 3-D chemistry transport model to better understand the composition and variation of aerosol over Borneo and the broader Southeast Asian region in conjunction with aircraft and satellite observations. Our focus on Southeast Asia reflects the importance of this region as a source of reactive organic gases and aerosols from natural forests, biomass burning, and food and fuel crops. We particularly focus on July 2008 when the UK BAe-146 research aircraft was deployed over northern Malaysian Borneo as part of the ACES/OP3 measurement campaign. During July 2008 we find using the model that Borneo (defined as Borneo Island and the surrounding Indonesian islands was a net exporter of primary organic aerosol (42 kT and black carbon aerosol (11 kT. We find only 13% of volatile organic compound oxidation products partition to secondary organic aerosol (SOA, with Borneo being a net exporter of SOA (15 kT. SOA represents approximately 19% of the total organic aerosol over the region. Sulphate is mainly from aqueous-phase oxidation (68%, with smaller contributions from gas-phase oxidation (15% and advection into the regions (14%. We find that there is a large source of sea salt, as expected, but this largely deposits within the region; we find that dust aerosol plays only a relatively small role in the aerosol burden. In contrast to coincident surface measurements over Northern Borneo that find a pristine environment with evidence for substantial biogenic SOA formation we find that the free troposphere is influenced by biomass burning aerosol transported from the northwest of the Island and further afield. We find several transport events during July 2008 over Borneo associated with elevated aerosol concentrations, none of which coincide with the aircraft flights. We use MODIS aerosol optical depths (AOD data and the model to put the July campaign into a longer temporal perspective. We find that Borneo is where

  2. The composition and variability of atmospheric aerosol over Southeast Asia during 2008

    Science.gov (United States)

    Trivitayanurak, W.; Palmer, P. I.; Barkley, M. P.; Robinson, N. H.; Coe, H.; Oram, D. E.

    2012-01-01

    We use a nested version of the GEOS-Chem global 3-D chemistry transport model to better understand the composition and variation of aerosol over Borneo and the broader Southeast Asian region in conjunction with aircraft and satellite observations. Our focus on Southeast Asia reflects the importance of this region as a source of reactive organic gases and aerosols from natural forests, biomass burning, and food and fuel crops. We particularly focus on July 2008 when the UK BAe-146 research aircraft was deployed over northern Malaysian Borneo as part of the ACES/OP3 measurement campaign. During July 2008 we find using the model that Borneo (defined as Borneo Island and the surrounding Indonesian islands) was a net exporter of primary organic aerosol (42 kT) and black carbon aerosol (11 kT). We find only 13% of volatile organic compound oxidation products partition to secondary organic aerosol (SOA), with Borneo being a net exporter of SOA (15 kT). SOA represents approximately 19% of the total organic aerosol over the region. Sulphate is mainly from aqueous-phase oxidation (68%), with smaller contributions from gas-phase oxidation (15%) and advection into the regions (14%). We find that there is a large source of sea salt, as expected, but this largely deposits within the region; we find that dust aerosol plays only a relatively small role in the aerosol burden. In contrast to coincident surface measurements over Northern Borneo that find a pristine environment with evidence for substantial biogenic SOA formation we find that the free troposphere is influenced by biomass burning aerosol transported from the northwest of the Island and further afield. We find several transport events during July 2008 over Borneo associated with elevated aerosol concentrations, none of which coincide with the aircraft flights. We use MODIS aerosol optical depths (AOD) data and the model to put the July campaign into a longer temporal perspective. We find that Borneo is where the model

  3. Tropospheric Aerosols

    Science.gov (United States)

    Buseck, P. R.; Schwartz, S. E.

    2003-12-01

    It is widely believed that "On a clear day you can see forever," as proclaimed in the 1965 Broadway musical of the same name. While an admittedly beautiful thought, we all know that this concept is only figurative. Aside from Earth's curvature and Rayleigh scattering by air molecules, aerosols - colloidal suspensions of solid or liquid particles in a gas - limit our vision. Even on the clearest day, there are billions of aerosol particles per cubic meter of air.Atmospheric aerosols are commonly referred to as smoke, dust, haze, and smog, terms that are loosely reflective of their origin and composition. Aerosol particles have arisen naturally for eons from sea spray, volcanic emissions, wind entrainment of mineral dust, wildfires, and gas-to-particle conversion of hydrocarbons from plants and dimethylsulfide from the oceans. However, over the industrial period, the natural background aerosol has been greatly augmented by anthropogenic contributions, i.e., those produced by human activities. One manifestation of this impact is reduced visibility (Figure 1). Thus, perhaps more than in other realms of geochemistry, when considering the composition of the troposphere one must consider the effects of these activities. The atmosphere has become a reservoir for vast quantities of anthropogenic emissions that exert important perturbations on it and on the planetary ecosystem in general. Consequently, much recent research focuses on the effects of human activities on the atmosphere and, through them, on the environment and Earth's climate. For these reasons consideration of the geochemistry of the atmosphere, and of atmospheric aerosols in particular, must include the effects of human activities. (201K)Figure 1. Impairment of visibility by aerosols. Photographs at Yosemite National Park, California, USA. (a) Low aerosol concentration (particulate matter of aerodynamic diameter less than 2.5 μm, PM2.5=0.3 μg m-3; particulate matter of aerodynamic diameter less than 10

  4. Exchanges in boundary layer and low troposphere and consequences on pollution of Fos-Berre-Marseille area (ESCOMPTE experiment); Les aerosols: emissions, formation d'aerosols organiques secondaires, transport longue distance. Zoom sur les aerosols carbones en Europe

    Energy Technology Data Exchange (ETDEWEB)

    Guillaume, B

    2006-01-15

    There are two types of 'carbonaceous aerosols': 'black carbon' (BC) and 'organic carbon'(OC). BC is directly emitted in the atmosphere while OC is either directly emitted (primary OC, OCp) or secondarily formed through oxidation processes in the atmosphere (secondary organic aerosols, SOA). Complexity of carbonaceous aerosols is still poorly represented in existing aerosol models and uncertainties appear mainly both in their emission inventories and in their complex atmospheric evolution (transport, gas-particle interactions, dry/wet deposition), making difficult the estimation of their radiative impact. In this framework, I developed during my PhD at Laboratoire d'Aerologie, a new approach to deal with this complexity, with implementation of both a new carbonaceous aerosol emission inventory and a new aerosol modelling tool at global scale. My work is divided in 5 different tasks: - better characterisation of BC and OCp emissions, achieved through the development of a new emission inventory from fossil fuel and biofuel combustion sources (industrial, domestic and mobile sources). This inventory provides BC and OCp emissions for Europe at 25 km * 25 km resolution for the years 1990, 1995, 2000, 2005 and 2010, with two additional regional zooms: on France, at 10 km * 10 km resolution for the years 2000 and 2010 with improved road traffic, and in Marseille region (Escompte campaign, 1999,-2001) at 1 km * 1 km resolution for the year 1999; - better modelling of carbonaceous aerosol complex atmospheric evolution, through coupling of a global scale gas transport/chemistry model (TM4) with an aerosol module (ORISAM) featuring size-distributed aerosols (on 8 diameter sections from 40 nm to 10 {mu}m) organic/inorganic chemical composition and explicit treatment of SOA formation; - simulations with this new aerosol model ORISAM-TM4 and model/measurements comparisons to study BC and OC long-range transport; - sensitivity tests on SOA

  5. Irradiation test plan of oxidation-resistant graphite in WWR-K Research Reactor

    International Nuclear Information System (INIS)

    Sumita, Junya; Shibata, Taiju; Sakaba, Nariaki; Osaki, Hirotaka; Kato, Hideki; Fujitsuka, Kunihiro; Muto, Takenori; Gizatulin, Shamil; Shaimerdenov, Asset; Dyussambayev, Daulet; Chakrov, Petr

    2014-01-01

    Graphite materials are used for the in-core components of High Temperature Gas-cooled Reactor (HTGR) which is a graphite-moderated and helium gas-cooled reactor. In the case of air ingress accident in HTGR, SiO_2 protective layer is formed on the surface of SiC layer in TRISO CFP and oxidation of SiC does not proceed and fission products are retained inside the fuel particle. A new safety concept for the HTGR, called Naturally Safe HTGR, has been recently proposed. To enhance the safety of Naturally Safe HTGR ultimately, it is expected that oxidation-resistant graphite is used for graphite components to prevent the TRISO CFPs and fuel compacts from failure. SiC coating is one of candidate methods for oxidation-resistant graphite. JAEA and four graphite companies launched R&Ds to develop the oxidation-resistant graphite and the International Science and Technology Center (ISTC) partner project with JAEA and INP was launched to investigate the irradiation effects on the oxidation-resistant graphite. To determine grades of the oxidation-resistant graphite which will be adopted as irradiation test, a preliminary oxidation test was carried out. This paper described the results of the preliminary oxidation test, the plan of out-of-pile test, irradiation test and post-irradiation test (PIE) of the oxidation-resistant graphite. The results of the preliminary oxidation test showed that the integrity of the oxidation resistant graphite was confirmed and that all of grades used in the preliminary test can be adopted as the irradiation test. Target irradiation temperature was determined to be 1473 (K) and neutron fluence was determined to be from 0.54 × 10"2"5through 1.4 × 10"2"5 (/m"2, E>0.18MeV). Weight change, oxidation rate, activation energy, surface condition, etc. will be evaluated in out-of-pile test and weight change, irradiation effect on oxidation rate and activation energy, surface condition, etc. will be evaluated in PIE. (author)

  6. Dissolution of LMFBR fuel-sodium aerosols

    International Nuclear Information System (INIS)

    Allen, M.D.; Moss, O.R.

    1979-01-01

    Plutonium dioxide, normally insoluble in biological fluids, becomes much more soluble when mixed with sodium as the aerosol is formed. Sodium-fuel aerosols are approximately 20 times less soluble in simulated lung fluid than in distilled water. Solubility of sodium-fuel aerosols increases when Na 2 CO 3 are added to the distilled-water dissolution fluid. Mixed-oxide fuel aerosols without sodium present are relatively insoluble in distilled water, simulated lung fluid, and distilled water with Na 2 CO 3 and NaHCO 3 added

  7. Aged organic aerosol in the Eastern Mediterranean: the Finokalia Aerosol Measurement Experiment – 2008

    Directory of Open Access Journals (Sweden)

    L. Hildebrandt

    2010-05-01

    Full Text Available Aged organic aerosol (OA was measured at a remote coastal site on the island of Crete, Greece during the Finokalia Aerosol Measurement Experiment-2008 (FAME-2008, which was part of the EUCAARI intensive campaign of May 2008. The site at Finokalia is influenced by air masses from different source regions, including long-range transport of pollution from continental Europe. A quadrupole aerosol mass spectrometer (Q-AMS was employed to measure the size-resolved chemical composition of non-refractory submicron aerosol (NR-PM1, and to estimate the extent of oxidation of the organic aerosol. Factor analysis was used to gain insights into the processes and sources affecting the OA composition. The particles were internally mixed and liquid. The largest fraction of the dry NR-PM1 sampled was ammonium sulfate and ammonium bisulfate, followed by organics and a small amount of nitrate. The variability in OA composition could be explained with two factors of oxygenated organic aerosol (OOA with differing extents of oxidation but similar volatility. Hydrocarbon-like organic aerosol (HOA was not detected. There was no statistically significant diurnal variation in the bulk composition of NR-PM1 such as total sulfate or total organic aerosol concentrations. However, the OA composition exhibited statistically significant diurnal variation with more oxidized OA in the afternoon. The organic aerosol was highly oxidized, regardless of the source region. Total OA concentrations also varied little with source region, suggesting that local sources had only a small effect on OA concentrations measured at Finokalia. The aerosol was transported for about one day before arriving at the site, corresponding to an OH exposure of approximately 4×1011 molecules cm−3 s. The constant extent of oxidation suggests that atmospheric aging results in a highly oxidized OA at these OH exposures, regardless of the aerosol source.

  8. Predicting Thermal Behavior of Secondary Organic Aerosols

    Science.gov (United States)

    Volume concentrations of steady-state secondary organic aerosol (SOA) were measured in 139 steadystate single precursor hydrocarbon oxidation experiments after passing through a temperature controlled inlet tube. Higher temperatures resulted in greater loss of particle volume, wi...

  9. Predicting Thermal Behavior of Secondary Organic Aerosols

    Data.gov (United States)

    U.S. Environmental Protection Agency — Volume concentrations of secondary organic aerosol (SOA) are measured in 139 steady-state, single precursor hydrocarbon oxidation experiments after passing through a...

  10. Current status of sodium fire and aerosol research in Japan

    International Nuclear Information System (INIS)

    Himeno, Yoshiaki

    1989-01-01

    State-of-the-art of the research and development related to sodium fire and aerosol behaviour is presented. This paper covers the Japanese work on sodium leak, leak detector, sodium oxidation and combustion, sodium aerosol release, fire mitigation, reliabilities of the electrical instruments and the reactor components under the sodium aerosols suspended atmosphere, aerosol plugging in a leak path, and the computer codes are presented. (author)

  11. PHYTOTOXICOLOGICAL TESTS - APPLICATIONS OF FOILS BASED ON GRAPHENE (GRAPHENE OXIDE

    Directory of Open Access Journals (Sweden)

    Petra ROUPCOVÁ

    2016-12-01

    Full Text Available This paper discusses the problematics of phytotoxicity of chemicals. It mainly focuses on the phytotoxicity of nanomaterials made of graphene. It describes phytotoxicological tests performed with foils from materials belonging to the graphene family. It also describes testing the influence of plants on these films. Furthermore, the paper discusses the issues of mutual influence between plants and tested nanomaterials.

  12. Estimation of Uncertainty in Aerosol Concentration Measured by Aerosol Sampling System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Chan; Song, Yong Jae; Jung, Woo Young; Lee, Hyun Chul; Kim, Gyu Tae; Lee, Doo Yong [FNC Technology Co., Yongin (Korea, Republic of)

    2016-10-15

    FNC Technology Co., Ltd has been developed test facilities for the aerosol generation, mixing, sampling and measurement under high pressure and high temperature conditions. The aerosol generation system is connected to the aerosol mixing system which injects SiO{sub 2}/ethanol mixture. In the sampling system, glass fiber membrane filter has been used to measure average mass concentration. Based on the experimental results using main carrier gas of steam and air mixture, the uncertainty estimation of the sampled aerosol concentration was performed by applying Gaussian error propagation law. FNC Technology Co., Ltd. has been developed the experimental facilities for the aerosol measurement under high pressure and high temperature. The purpose of the tests is to develop commercial test module for aerosol generation, mixing and sampling system applicable to environmental industry and safety related system in nuclear power plant. For the uncertainty calculation of aerosol concentration, the value of the sampled aerosol concentration is not measured directly, but must be calculated from other quantities. The uncertainty of the sampled aerosol concentration is a function of flow rates of air and steam, sampled mass, sampling time, condensed steam mass and its absolute errors. These variables propagate to the combination of variables in the function. Using operating parameters and its single errors from the aerosol test cases performed at FNC, the uncertainty of aerosol concentration evaluated by Gaussian error propagation law is less than 1%. The results of uncertainty estimation in the aerosol sampling system will be utilized for the system performance data.

  13. An exploratory study of alkali sulfate aerosol formation during biomass combustion

    DEFF Research Database (Denmark)

    Løj, Lusi Hindiyarti; Frandsen, Flemming; Livbjerg, Hans

    2008-01-01

    mechanism. The modeling predictions are compared to data from laboratory experiments and entrained flow reactor experiments available in the literature. The analysis support that alkali sulfate aerosols are formed from homogeneous nucleation following a series of steps occurring in the gas phase. The rate......It is still in discussion to what extent alkali sulfate aerosols in biomass combustion are formed in the gas phase by a homogeneous mechanism or involve heterogeneous or catalyzed reactions. The present study investigates sulfate aerosol formation based on calculations with a detailed gas phase......-limiting step may be the oxidation of sulfite to sulfate, rather than the oxidation of SO2 to SO3 proposed previously. Even though the proposed model is consistent with experimental observations, experiments in a rigorously homogeneous system are called for to test its validity....

  14. DSMC multicomponent aerosol dynamics: Sampling algorithms and aerosol processes

    Science.gov (United States)

    Palaniswaamy, Geethpriya

    The post-accident nuclear reactor primary and containment environments can be characterized by high temperatures and pressures, and fission products and nuclear aerosols. These aerosols evolve via natural transport processes as well as under the influence of engineered safety features. These aerosols can be hazardous and may pose risk to the public if released into the environment. Computations of their evolution, movement and distribution involve the study of various processes such as coagulation, deposition, condensation, etc., and are influenced by factors such as particle shape, charge, radioactivity and spatial inhomogeneity. These many factors make the numerical study of nuclear aerosol evolution computationally very complicated. The focus of this research is on the use of the Direct Simulation Monte Carlo (DSMC) technique to elucidate the role of various phenomena that influence the nuclear aerosol evolution. In this research, several aerosol processes such as coagulation, deposition, condensation, and source reinforcement are explored for a multi-component, aerosol dynamics problem in a spatially homogeneous medium. Among the various sampling algorithms explored the Metropolis sampling algorithm was found to be effective and fast. Several test problems and test cases are simulated using the DSMC technique. The DSMC results obtained are verified against the analytical and sectional results for appropriate test problems. Results show that the assumption of a single mean density is not appropriate due to the complicated effect of component densities on the aerosol processes. The methods developed and the insights gained will also be helpful in future research on the challenges associated with the description of fission product and aerosol releases.

  15. Tests of regional elemental tracers of pollution aerosols. 1. Distinctness of regional signatures, stability during transport, and empirical validation

    International Nuclear Information System (INIS)

    Lowenthal, D.H.; Wunschel, K.R.; Rahn, K.A.

    1988-01-01

    The two major requirements for a successful regional tracer system are distinctness of signatures and stability of signatures during transport. Dissimilarity of the five regional signatures from eastern North America is shown by collinearity diagnostics and by apportionment of synthetic samples generated randomly. Stability of regional signatures during transport is shown first by use of tracer elements in coarse and fine aerosol to predict the maximum possible change of ratios from particle-size effects alone and then by examination of actual changes in signatures during transport from the Midwest to Underhill, VT. Two recent empirical validations of the tracer system are presented: qualitative agreement of pulses of mid-western aerosol in Vermont with pulses of perfluorocarbon tracer gas released in Ohio during CAPTEX '83 and reproduction of our three major northeastern and mid-western signatures by other investigators. The tracer system currently uses the seven elements As, Se, Sb, Zn, In, noncrustal Mn, and noncrustal V as measured by instrumental neutron activation

  16. Performance of multiple HEPA filters against plutonium aerosols

    International Nuclear Information System (INIS)

    Gonzales, M.; Elder, J.; Ettinger, H.

    1975-01-01

    Performance of multiple stages of High Efficiency Particulate Air (HEPA) filters against aerosols similar to those produced by plutonium processing facilities has been verified as part of an experimental program. A system of three HEPA filters in series was tested against 238 PuO 2 aerosol concentrations as high as 3.3 x 10 10 d/s-m 3 . An air nebulization aerosol generation system, using ball milled plutonium oxide suspended in water, provided test aerosols with size characteristics similar to those defined by a field sampling program at several different AEC plutonium processing facilities. Aerosols have been produced ranging from 0.22 μm activity median aerodynamic diameter (amad) to 1.6 μm amad. The smaller size distributions yield 10 to 30 percent of the total activity in the less than 0.22 μm size range allowing efficiency measurement as a function of size for the first two HEPA filters in series. The low level of activity on the sampler downstream of the third HEPA filter (approximately 0.01 c/s) precludes aerosol size characterization downstream of this filter. For the first two HEPA filters, overall efficiency, and efficiency as a function of size, exceeds 99.98 percent including the <0.12 μm and the 0.12 to 0.22 μm size intervals. Efficiency of the third HEPA filter is somewhat lower with an overall average efficiency of 99.8 percent and an apparent minimum efficiency of 99.5 percent. This apparently lower efficiency is an artifact due to the low level of activity on the sampler downstream of HEPA No. 3 and the variations due to counting statistics. Recent runs with higher concentrations, thereby improving statistical variations, show efficiencies well within minimum requirements. (U.S.)

  17. Genotoxicity of indium tin oxide by comet test

    Directory of Open Access Journals (Sweden)

    İbrahim Hakkı Ciğerci

    2015-06-01

    Full Text Available Indium tin oxide (ITO is used for liquid crystal display (LCDs, electrochromic displays, flat panel displays, field emission displays, touch or laptop computer screens, cell phones, energy conserving architectural windows, defogging aircraft and automobile windows, heat-reflecting coatings to increase light bulb efficiency, gas sensors, antistatic window coatings, wear resistant layers on glass, nanowires and nanorods because of its unique properties of high electrical conductivity, transparency and mechanical resistance.Genotoxic effects of ITO were investigated on the root cells of Allium cepa by Comet assay. A. cepa roots were treated with the aqueous dispersions of ITO at 5 different concentrations (12.5, 25, 50, 75, and 100 ppm for 4 h. A significant increase in DNA damage was a observed at all concentrations of ITO by Comet assay. These result indicate that ITO exhibit genotoxic activity in A. cepa root meristematic cells.

  18. NMR relaxation induced by iron oxide particles: testing theoretical models.

    Science.gov (United States)

    Gossuin, Y; Orlando, T; Basini, M; Henrard, D; Lascialfari, A; Mattea, C; Stapf, S; Vuong, Q L

    2016-04-15

    Superparamagnetic iron oxide particles find their main application as contrast agents for cellular and molecular magnetic resonance imaging. The contrast they bring is due to the shortening of the transverse relaxation time T 2 of water protons. In order to understand their influence on proton relaxation, different theoretical relaxation models have been developed, each of them presenting a certain validity domain, which depends on the particle characteristics and proton dynamics. The validation of these models is crucial since they allow for predicting the ideal particle characteristics for obtaining the best contrast but also because the fitting of T 1 experimental data by the theory constitutes an interesting tool for the characterization of the nanoparticles. In this work, T 2 of suspensions of iron oxide particles in different solvents and at different temperatures, corresponding to different proton diffusion properties, were measured and were compared to the three main theoretical models (the motional averaging regime, the static dephasing regime, and the partial refocusing model) with good qualitative agreement. However, a real quantitative agreement was not observed, probably because of the complexity of these nanoparticulate systems. The Roch theory, developed in the motional averaging regime (MAR), was also successfully used to fit T 1 nuclear magnetic relaxation dispersion (NMRD) profiles, even outside the MAR validity range, and provided a good estimate of the particle size. On the other hand, the simultaneous fitting of T 1 and T 2 NMRD profiles by the theory was impossible, and this occurrence constitutes a clear limitation of the Roch model. Finally, the theory was shown to satisfactorily fit the deuterium T 1 NMRD profile of superparamagnetic particle suspensions in heavy water.

  19. Perform Tests and Document Results and Analysis of Oxide Layer Effects and Comparisons

    Energy Technology Data Exchange (ETDEWEB)

    Collins, E. D. [ORNL; DelCul, G. D. [ORNL; Spencer, B. B. [ORNL; Hunt, R. D. [ORNL; Ausmus, C. [ORNL

    2014-08-30

    During the initial feasibility test using actual used nuclear fuel (UNF) cladding in FY 2012, an incubation period of 30–45 minutes was observed in the initial dry chlorination. The cladding hull used in the test had been previously oxidized in a dry air oxidation pretreatment prior to removal of the fuel. The cause of this incubation period was attributed to the resistance to chlorination of an oxide layer imparted by the dry oxidation pretreatment on the cladding. Subsequently in 2013, researchers at the Korea Atomic Energy Institute (KAERI) reported on their chlorination study [R1] on ~9-gram samples of unirradiated ZirloTM cladding tubes that had been previously oxidized in air at 500oC for various time periods to impart oxide layers of varying thickness. In early 2014, discussions with Indefinite Delivery, Indefinite Quantity (IDIQ) contracted technical consultants from Westinghouse described their previous development (and patents) [R2] on methods of chemical washing to remove some or all of the hydrous oxide layer imparted on UNF cladding during irradiation in light water reactors (LWRs) . Thus, the Oak Ridge National Laboratory (ORNL) study, described herein, was planned to extend the KAERI study on the effects of anhydrous oxide layers, but on larger ~100-gram samples of unirradiated zirconium alloy cladding tubes, and to investigate the effects of various methods of chemical pretreatment prior to chlorination with 100% chlorine on the average reaction rates and Cl2 usage efficiencies.

  20. Simulating secondary organic aerosol in a regional air quality model using the statistical oxidation model – Part 2: Assessing the influence of vapor wall losses

    Directory of Open Access Journals (Sweden)

    C. D. Cappa

    2016-03-01

    Full Text Available The influence of losses of organic vapors to chamber walls during secondary organic aerosol (SOA formation experiments has recently been established. Here, the influence of such losses on simulated ambient SOA concentrations and properties is assessed in the University of California at Davis / California Institute of Technology (UCD/CIT regional air quality model using the statistical oxidation model (SOM for SOA. The SOM was fit to laboratory chamber data both with and without accounting for vapor wall losses following the approach of Zhang et al. (2014. Two vapor wall-loss scenarios are considered when fitting of SOM to chamber data to determine best-fit SOM parameters, one with “low” and one with “high” vapor wall-loss rates to approximately account for the current range of uncertainty in this process. Simulations were run using these different parameterizations (scenarios for both the southern California/South Coast Air Basin (SoCAB and the eastern United States (US. Accounting for vapor wall losses leads to substantial increases in the simulated SOA concentrations from volatile organic compounds (VOCs in both domains, by factors of  ∼  2–5 for the low and  ∼  5–10 for the high scenarios. The magnitude of the increase scales approximately inversely with the absolute SOA concentration of the no loss scenario. In SoCAB, the predicted SOA fraction of total organic aerosol (OA increases from  ∼  0.2 (no to  ∼  0.5 (low and to  ∼  0.7 (high, with the high vapor wall-loss simulations providing best general agreement with observations. In the eastern US, the SOA fraction is large in all cases but increases further when vapor wall losses are accounted for. The total OA ∕ ΔCO ratio captures the influence of dilution on SOA concentrations. The simulated OA ∕ ΔCO in SoCAB (specifically, at Riverside, CA is found to increase substantially during the day only for the high vapor wall

  1. The Application of a Modified d-ROMs Test for Measurement of Oxidative Stress and Oxidized High-Density Lipoprotein

    Directory of Open Access Journals (Sweden)

    Fumiaki Ito

    2017-02-01

    Full Text Available Reactive oxygen species (ROS are involved in the initiation and progression of atherosclerosis. ROS-derived hydroperoxides, as an indicator of ROS production, have been measured by using the diacron reactive oxygen metabolites (d-ROMs test, which requires iron-containing transferrin in the reaction mixture. In this study we developed a modified d-ROMs test, termed the Fe-ROMs test, where iron ions were exogenously added to the reaction mixture. This modification is expected to exclude the assay variation that comes from different blood iron levels in individuals. In addition, this Fe-ROMs test was helpful for determining the class of plasma lipoproteins that are hydroperoxidized. Low-density lipoprotein/very low-density lipoprotein (LDL/VLDL and high-density lipoprotein (HDL were purified by use of an LDL/VLDL purification kit and the dextran sulfate-Mg2+ precipitation method, respectively; their hydroperoxide contents were assessed by performing the Fe-ROMs test. The majority of the hydroperoxides were detected only in the HDL fraction, not in the LDL/VLDL. Further detailed analysis of HDLs by size-exclusion high-performance liquid chromatography revealed that the hydroperoxide-containing molecules were small-sized HDLs. Because HDL was shown to be the principal vehicle for the plasma hydroperoxides, this Fe-ROMs test is a beneficial method for the assessment of oxidized-HDL levels. Indeed, Fe-ROMs levels were strongly associated with the levels of oxidized HDL, which were determined by performing the malondialdehyde-modified HDL enzyme immunoassay. In conclusion, the Fe-ROMs test using plasma itself or the HDL fraction after dextran sulfate-Mg2+ precipitation is useful to assess the functionality of HDL, because the oxidation of HDL impairs its antiatherogenic capacity.

  2. Yields of aerosol precursor substances by the oxidation of DMS as a function of atmospheric conditions (temperature and NOx). Final report; Ausbeuten von Aerosolvorlaeufersubstanzen bei der DMS-Oxidation als Funktion von atmosphaerischen Bedingungen (Temperatur und NO{sub x}). Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, I.; Albu, M.; Arsene, C.; Butkovskaya, N.I.; Patroescu, I.V.

    2002-04-28

    In-depth analyses have been made of the products and aerosol formation from the OH-radical initiated oxidation of dimethyl sulphide (CH3SCH3: DMS) as a function of temperature, O2 partial pressure and initial NO concentration in large photoreactors. The investigations have provided new insights into the oxidation mechanisms of both DMS and DMSO, e.g., it has been shown that interactions of the DMS-OH adduct with O2 form DMSO in the absence of NO and dimethyl sulphone (CH3SO2CH3: DMSO2) in its presence. The data support an SO2 yield of around 70% from OH + DMS in the remote marine atmosphere. Investigations on the OH-radical initiated oxidation of dimethyl sulphoxide (CH3SOCH3: DMSO) have shown for the first time that methane sulphinic acid (CH3S(O)OH: MSIA) is the major product. Within the experimental conditions employed in the experiments only a modest dependence of the aerosol yield on temperature and initial NO concentration was observed. The experiments support that sulphuric acid formed from OH + SO2 is the major component of the aerosol with only minor contributions from MSA and MSIA. The mechanistic information is being incorporated into a DMS atmospheric chemistry modeule for CTMs (http://www.dmi.dk/f+u/luft/eng/elcid/elcid.html) and also in a simplified form for a global climate model (http://ask.ii.uib.no/.climate/elcid/). (orig.)

  3. A field-scale test of in situ chemical oxidation through recirculation

    International Nuclear Information System (INIS)

    West, O.R.; Cline, S.R.; Holden, W.L.; Gardner, F.G.; Schlosser, B.M.; Siegrist, R.L.; Houk, T.C.

    1998-01-01

    In situ chemical oxidation is a developing class of remediation technologies in which organic contaminants are degraded in place by powerful oxidants. Successful implementation of this technology requires an effective means for dispersing the oxidant to contaminated regions in the subsurface. An oxidant delivery technique has been developed wherein the treatment solution is made by adding an oxidant to extracted groundwater. The oxidant-laden groundwater is then injected and recirculated into a contaminated aquifer through multiple horizontal and/or vertical wells. This technique, referred to as in situ chemical oxidation through recirculation (ISCOR), can be applied to saturated and hydraulically conductive formations and used with relatively stable oxidants such as potassium permanganate (KMnO 4 ). A field-scale test of ISCOR was conducted at a site (Portsmouth Gaseous Diffusion Plant) where groundwater in a 5-ft thick silty gravel aquifer is contaminated with trichloroethylene (TCE) at levels that indicate the presence of residual dense non-aqueous phase liquids (DNAPLs). The field test was implemented using a pair of parallel horizontal wells with 200-ft screened sections. For approximately one month, groundwater was extracted from one horizontal well, dosed with crystalline KMnO 4 , and re-injected into the other horizontal well 90 ft away. Post-treatment characterization showed that ISCOR was effective at removing TCE in the saturated region. Lateral and vertical heterogeneities within the treatment zone impacted the uniform delivery of the oxidant solution. However, TCE was not detected in groundwater samples collected from monitoring wells and soil samples from borings in locations where the oxidant had permeated

  4. 2-D model of global aerosol transport

    Energy Technology Data Exchange (ETDEWEB)

    Rehkopf, J; Newiger, M; Grassl, H

    1984-01-01

    The distribution of aerosol particles in the troposphere is described. Starting with long term mean seasonal flow and diffusivities as well as temperature, cloud distribution (six cloud classes), relative humidity and OH radical concentration, the steady state concentration of aerosol particles and SO/sub 2/ are calculated in a two-dimensional global (height and latitude) model. The following sources and sinks for particles are handled: direct emission, gas-to-particle conversion from SO/sub 2/, coagulation, rainout, washout, gravitational settling, and dry deposition. The sinks considered for sulphur emissions are dry deposition, washout, rainout, gasphase oxidation, and aqueous phase oxidation. Model tests with the water vapour cycle show a good agreement between measured and calculated zonal mean precipitation distribution. The steady state concentration distribution for natural emissions reached after 10 weeks model time, may be described by a mean exponent ..cap alpha.. = 3.2 near the surface assuming a modified Junge distribution and an increased value, ..cap alpha.. = 3.7, for the combined natural and man-made emission. The maximum ground level concentrations are 2000 and 10,000 particules cm/sup -3/ for natural and natural plus man-made emissions, respectively. The resulting distribution of sulphur dioxide agrees satisfactorily with measurements given by several authors. 37 references, 4 figures.

  5. Field test results for steam oxidation of TP347H FG - growth of inner oxide

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Jianmin, Jia; Larsen, OH

    2005-01-01

    A series of field tests have been conducted with TP347H FG in test superheater loops in coal-fired and biomass fired boilers of steam pressure 256 and 91 bar respectively. The exposure times are from 3,500 to 30,000 hours and the temperature range is from 450-630¢XC. The morphology, composition...

  6. Solubility of plutonium dioxide aerosols, in vitro

    International Nuclear Information System (INIS)

    Newton, G.J.; Kanapilly, G.M.

    1976-01-01

    Solubility of plutonium aerosols is an important parameter in establishing risk estimates for industrial workers who might accidentally inhale these materials and in evaluating environmental health impacts associated with Pu. In vitro solubility of industrial plutonium aerosols in a simulated lung fluid is compared to similar studies with ultrafine aerosols from laser ignition of delta phase plutonium metal and laboratory-produced spherical particles of 238 PuO 2 and 239 PuO 2 . Although relatively insoluble, industrial plutonium-mixed oxide aerosols were much more soluble than laboratory-produced plutonium dioxide particles. Chain agglomerate aerosols from laser ignition of metallic Pu indicated in vitro dissolution half-times of 10 and 50 days for activity median aerodynamic diameter (AMAD) of 0.7 and 2.3 μm, respectively. Plutonium-containing mixed oxide aerosols indicated dissolution half-times of 40 to 500 days for particles formed by industrial powder comminution and blending. Centerless grinding of fuel pellets yielded plutonium-containing aerosols with dissolution half-times of 1200 to 8000 days. All mixed oxide particles were in the size range 1.0 μm to 2.5 μm AMAD

  7. Filter-based Aerosol Measurement Experiments using Spherical Aerosol Particles under High Temperature and High Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Chan; Jung, Woo Young; Lee, Hyun Chul; Lee, Doo Young [FNC TECH., Yongin (Korea, Republic of)

    2016-05-15

    Optical Particle Counter (OPC) is used to provide real-time measurement of aerosol concentration and size distribution. Glass fiber membrane filter also be used to measure average mass concentration. Three tests (MTA-1, 2 and 3) have been conducted to study thermal-hydraulic effect, a filtering tendency at given SiO{sub 2} particles. Based on the experimental results, the experiment will be carried out further with a main carrier gas of steam and different aerosol size. The test results will provide representative behavior of the aerosols under various conditions. The aim of the tests, MTA 1, 2 and 3, are to be able to 1) establish the test manuals for aerosol generation, mixing, sampling and measurement system, which defines aerosol preparation, calibration, operating and evaluation method under high pressure and high temperature 2) develop commercial aerosol test modules applicable to the thermal power plant, environmental industry, automobile exhaust gas, chemical plant, HVAC system including nuclear power plant. Based on the test results, sampled aerosol particles in the filter indicate that important parameters affecting aerosol behavior aerosols are 1) system temperature to keep above a evaporation temperature of ethanol and 2) aerosol losses due to the settling by ethanol liquid droplet.

  8. Glyoxal contribution to aerosols over Los Angeles

    Science.gov (United States)

    Balcerak, Ernie

    2012-01-01

    Laboratory and field studies have indicated that glyoxal (chemical formula OCHCHO), an atmospheric oxidation product of isoprene and aromatic compounds, may contribute to secondary organic aerosols in the atmosphere, which can block sunlight and affect atmospheric chemistry. Some aerosols are primary aerosols, emitted directly into the atmosphere, while others are secondary, formed through chemical reactions in the atmosphere. Washenfelder et al. describe in situ glyoxal measurements from Pasadena, Calif., near Los Angeles, made during summer 2010. They used three different methods to calculate the contribution of glyoxal to secondary atmospheric aerosol and found that it is responsible for 0-0.2 microgram per cubic meter, or 0-4%, of the secondary organic aerosol mass. The researchers also compared their results to those of a previous study that calculated the glyoxal contribution to aerosol for Mexico City. Mexico City had higher levels of organic aerosol mass from glyoxal. They suggest that the lower contribution of glyoxal to aerosol concentrations for Los Angeles may be due to differences in the composition or water content of the aerosols above the two cities. (Journal of Geophysical Research-Atmospheres, doi:10.1029/2011JD016314, 2011)

  9. SOCTESQA - Solid Oxide Cell and Stack Testing, Safety and Quality Assurance

    OpenAIRE

    Lang, Michael; Auer, Corinna; Couturier, Karine; Nielsen, Eva Ravn; Mc Phail, Stephen; Kotsionopoulos, Nikolaos; FU, Qingxi; Liu, Qinglin

    2015-01-01

    For the successful market penetration of high temperature solid oxide fuel/electrolysis cell energy systems it is necessary to increase the quality assurance and the reliable assessment of the corresponding cells and stacks. Therefore in May 2014 the EU-funded project SOCTESQA was launched. Partners from different countries in Europe and one external party from Singapore are working together to develop uniform and industry wide test procedures and programs for solid oxide cell/stack (SOC) ass...

  10. Argonne National Laboratory's photo-oxidation organic mixed waste treatment system - installation and startup testing

    International Nuclear Information System (INIS)

    Shearer, T.L.; Nelson, R.A.; Torres, T.; Conner, C.; Wygmans, D.

    1997-01-01

    This paper describes the installation and startup testing of the Argonne National Laboratory (ANL-E) Photo-Oxidation Organic Mixed Waste Treatment System. This system will treat organic mixed (i.e., radioactive and hazardous) waste by oxidizing the organics to carbon dioxide and inorganic salts in an aqueous media. The residue will be treated in the existing radwaste evaporators. The system is installed in the Waste Management Facility at the ANL-E site in Argonne, Illinois. 1 fig

  11. Supercritical water oxidation test bed effluent treatment study

    International Nuclear Information System (INIS)

    Barnes, C.M.

    1994-04-01

    This report presents effluent treatment options for a 50 h Supercritical Water Test Unit. Effluent compositions are calculated for eight simulated waste streams, using different assumed cases. Variations in effluent composition with different reactor designs and operating schemes are discussed. Requirements for final effluent compositions are briefly reviewed. A comparison is made of two general schemes. The first is one in which the effluent is cooled and effluent treatment is primarily done in the liquid phase. In the second scheme, most treatment is performed with the effluent in the gas phase. Several unit operations are also discussed, including neutralization, mercury removal, and evaporation

  12. Test plan for long-term, low-temperature oxidation of spent fuel, Series 1

    International Nuclear Information System (INIS)

    Einziger, R.E.

    1986-06-01

    Preliminary studies indicated the need for more spent fuel oxidation data in order to determine the probable behavior of spent fuel in a tuff repository. Long-term, low-temperature testing was recommended in a comprehensive technical approach to: (1) confirm the findings of the short-term thermogravimetric analyses scoping experiments; (2) evaluate the effects of variables such as burnup, atmospheric moisture and fuel type on the oxidation rate; and (3) extend the oxidation data base ot representative repository temperatures and better define the temperature dependence of the operative oxidation mechanisms. This document presents the Series 1 test plan to study, on a large number of samples, the effects of atmospheric moisture and temperature on oxidation rate and phase formation. Tests will run for up to two years, use characterized fragmented, and pulverized fuel samples, cover a temperature range of 110 0 C to 175 0 C and be conducted with an atmospheric moisture content rangeing from 0 C to approx. 80 0 C dew point. After testing, the samples will be examined and made available for leaching testing

  13. TOMS Absorbing Aerosol Index

    Data.gov (United States)

    Washington University St Louis — TOMS_AI_G is an aerosol related dataset derived from the Total Ozone Monitoring Satellite (TOMS) Sensor. The TOMS aerosol index arises from absorbing aerosols such...

  14. Study of the Rancimat test method in measuring the oxidation stability of biodiesel ester and blends

    Energy Technology Data Exchange (ETDEWEB)

    Berthiaume, D.; Tremblay, A. [Oleotek Inc., Thetford Mines, PQ (Canada)

    2006-11-15

    This paper provided details of a study conducted to examine the oxidation stability of biodiesel blends. The study tested samples of canola oil, soybean oil, fish oil, yellow grease, and tallow. The EN 14112 (Rancimat) method was used to compare oxidation stability results obtained in previous tests conducted in the United States and Europe. The aim of the study was also to evaluate the influence of peroxide value (PV), acid value (AV) and feedstock source on the the oxidative stability of different samples. The study also evaluated the possibility of developing a validated test method developed from the EN 14112 methods to specifically consider biodiesel blends. Results of the study indicated that the Rancimat method was not suitable for measuring the oxidation stability of biodiesels blended with petrodiesels. No direct correlation between oxidative stability and PV or AV was observed. It was concluded that fatty acid distribution was not a principal factor in causing changes in oxidation stability. 22 refs., 3 tabs., 1 fig.

  15. A perspective on SOA generated in aerosol water from glyoxal and methylglyoxal and its impacts on climate-relevant aerosol properties

    Science.gov (United States)

    Sareen, N.; McNeill, V. F.

    2011-12-01

    . These compounds included (hemi)acetals, aldol condensation products, and oligomeric species up to 759 amu. Since these products are vulnerable to oxidants such as O3 and OH in the atmosphere, kinetic studies were conducted to study their affect upon exposure to O3 and OH. Custom-designed flow tube reactors were coupled with the Aerosol-CIMS to monitor aerosol composition, and consequently this data was used to determine reactive uptake coefficients (γO3~10-8 and γOH~ 10-6). Additionally, the lifetime of these SOA species in the atmosphere can be estimated and if these time scales are sufficiently long, they may affect aerosol optical properties. The effect of oxidation on the optical properties is also currently being tested by collecting aerosol particles before and after oxidation on a quartz window and testing changes in absorption using the UV-Vis spectrophotometer. The results of all these studies will be integrated to understand the role of methylglyoxal as a SOA precursor and the effect on various aerosol properties, and this will be used as a model system to predict the fate of similar organics in the atmosphere.

  16. Correlation of Secondary Organic Aerosol with Odd Oxygen in Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Herndon, Scott C.; Onasch, Timothy B.; Wood, Ezra C.; Kroll, Jesse H.; Canagaratna, M. R.; Jayne, John T.; Zavala, Miguel A.; Knighton, W. Berk; Mazzoleni, Claudio; Dubey, Manvendra K.; Ulbrich, Ingrid M.; Jimenez, Jose L.; Seila, Robert; de Gouw, Joost A.; de Foy, B.; Fast, Jerome D.; Molina, Luisa T.; Kolb, C. E.; Worsnop, Douglas R.

    2008-08-05

    Data collected from a mountain location within the Mexico City limits are used to demonstrate a correlation between secondary organic aerosol and odd-oxygen (O3 + NO2). Positive matrix factorization techniques are employed to separate organic aerosol components: hydrocarbon-like organic aerosol; oxidized-organic aerosol; and biomass burning organic aerosol. The measured hydrocarbon-like organic aerosol is correlated with urban CO (8±1) µg m-3 ppmv-1. The measured oxidized-organic aerosol is associated with photochemical oxidation products and correlates with odd-oxygen with an apparent slope of (70-120) µg m-3 ppmv-1. The dependence of the oxidized-organic aerosol to odd-oxygen correlation on the nature of the gas-phase hydrocarbon profile is discussed.

  17. Oxide-metal corium-concrete interaction test in the Vulcano facility

    International Nuclear Information System (INIS)

    Journeau, Ch.; Piluso, P.; Haquet, J.F.; Saretta, S.; Boccaccio, E.; Bonnet, J.M.

    2007-01-01

    Corium is likely to melt through the vessel and interact with the reactor pit concrete. Corium is made of a UO 2 -rich oxidic part, in which most of the decay heat is dissipated, and of a metallic part, mainly molten steel. An experiment has been set up in the Vulcano facility in which oxidic and metallic mixtures are molten in separate furnaces and poured in a concrete cavity. Induction heating is provided to the pool upper part thanks to shielding coils, so that, in case of stratification, the lighter oxidic corium-concrete mixture receives most of the power. Pre-calculations with the TOLBIAC-ICB corium-concrete interaction code based on the phase segregation model have provided valuable information for the dimensioning of this test: a thick metallic layer (>10 kg or 4 cm) has been chosen in order to obtain significant cavity ablation profiles depending on the selected heat transfer and stratification models. Stratification of the two liquid phases is predicted to occur in less than 10 minutes. In September 2006, the experiment was performed in the Vulcano facility. The corium was made of about 15 kg of steel at 1700 C and 30 kg of oxides (70% UO 2 , 16 % ZrO 2 and 14% concrete load) above 2000 C. It was poured in a limestone-rich concrete. This concrete type was selected for the first test, since the ablation is isotropic except for the initial transient, during oxidic corium-concrete interaction tests. 32 kW of induction power have been provided to the pool during the 4-hour test. The destruction of in-concrete thermocouples indicates that ablation was first mainly radial then became isotropic. This is quite similar to the ablation progression observed during previous tests with oxidic corium interacting with this type of concrete. Important 'volcanic activity' has been observed at the corium pool surface, compared to the previous oxidic corium experiments at Vulcano. (authors)

  18. Measuring aerosols generated inside armoured vehicles perforated by depleted uranium ammunition

    International Nuclear Information System (INIS)

    Parkhurst, M.A.

    2003-01-01

    In response to questions raised after the Gulf War about the health significance of exposure to depleted uranium (DU), the US Department of Defense initiated a study designed to provide an improved scientific basis for assessment of possible health effects on soldiers in vehicles struck by these munitions. As part of this study, a series of DU penetrators were fired at an Abrams tank and a Bradley fighting vehicle, and the aerosols generated by vehicle perforation were collected and characterised. A robust sampling system was designed to collect aerosols in this difficult environment and monitor continuously the sampler flow rates. The aerosol samplers selected for these tests included filter cassettes, cascade impactors, a five-stage cyclone and a moving filter. Sampler redundancy was an integral part of the sampling system to offset losses from fragment damage. Wipe surveys and deposition trays collected removable deposited particulate matter. Interior aerosols were analysed for uranium concentration and particle size distribution as a function of time. They were also analysed for uranium oxide phases, particle morphology and dissolution in vitro. These data, currently under independent peer review, will provide input for future prospective and retrospective dose and health risk assessments of inhaled or ingested DU aerosols. This paper briefly discusses the target vehicles, firing trajectories, aerosol samplers and instrumentation control systems, and the types of analyses conducted on the samples. (author)

  19. Solid Oxide Cell and Stack Testing, Safety and Quality Assurance (SOCTESQA)

    DEFF Research Database (Denmark)

    Auer, C.; Lang, M.; Couturier, K.

    2015-01-01

    The market penetration of fuel and electrolysis cell energy systems in Europe requires the development of reliable assessment, testing and prediction of performance and durability of solid oxide cells and stacks (SOC). To advance in this field the EU-project “SOCTESQA” was launched in May 2014...... and dynamic operating conditions. The application specific test programs are created by combining several of these test modules. In a next step defined test modules will be applied for the initial test bench validation, which will be improved by several validation loops. The final test protocols...

  20. Toughness testing and high-temperature oxidation evaluations of advanced alloys for core internals

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Lizhen [ORNL; Pint, Bruce A [ORNL; Chen, Xiang [ORNL

    2016-09-16

    Alloy X-750 was procured from Carpenter Technology and Bodycote in this year. An appropriate TMT was developed on Alloy 439 to obtain materials with refined grain size for property screening tests. Charpy V-notch impact tests were completed for the three ferritic steels Grade 92, Alloy 439, and 14YWT. Fracture toughness tests at elevated temperatures were completed for 14YWT. The tests will be completed for the other alloys in next fiscal year. Steam oxidation tests of the three ferritic steels, 316L, and Zr–2.5Nb have been completed. The steam tests of the Ni-based superalloys and the other austenitic stainless steels will be continued and finished in next fiscal year. Performance ranking in terms of steam oxidation resistance and impact/fracture toughness of the alloys will be deduced.

  1. Source term experiments project (STEP): aerosol characterization system

    International Nuclear Information System (INIS)

    Schlenger, B.J.; Dunn, P.F.

    1985-01-01

    A series of four experiments is being conducted at Argonne National Laboratory's TREAT Reactor. They have been designed to provide some of the necessary data regarding magnitude and release rates of fission products from degraded fuel pins, physical and chemical characteristics of released fission products, and aerosol formation and transport phenomena. These are in-pile experiments, whereby the test fuel is heated by neutron induced fission and subsequent clad oxidation in steam environments that simulate as closely as practical predicted reactor accident conditions. The test sequences cover a range of pressure and fuel heatup rate, and include the effect of Ag/In/Cd control rod material

  2. Aerosol Physics Considerations for Using Cerium Oxide CeO2 as a Surrogate for Plutonium Oxide PuO2 in Airborne Release Fraction Measurements for Storage Container Investigations

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Murray E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tao, Yong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-16

    Cerium oxide (CeO2) dust is recommended as a surrogate for plutonium oxide (PuO2) in airborne release fraction experiments. The total range of applicable particle sizes for PuO2 extends from 0.0032 μm (the diameter of a single PuO2 molecule) to 10 μm (the defined upper boundary for respirable particles). For particulates with a physical particle diameter of 1.0 μm, the corresponding aerodynamic diameters for CeO2 and PuO2 are 2.7 μm and 3.4 μm, respectively. Cascade impactor air samplers are capable of measuring the size distributions of CeO2 or PuO2 particulates. In this document, the aerodynamic diameters for CeO2 and PuO2 were calculated for seven different physical diameters (0.0032, 0.02, 0.11, 0.27, 1.0, 3.2, and 10 μm). For cascade impactor measurements, CeO2 and PuO2 particulates with the same physical diameter would be collected onto the same or adjacent collection substrates. The difference between the aerodynamic diameter of CeO2 and PuO2 particles (that have the same physical diameter) is 39% of the resolution of a twelve-stage MSP Inc. 125 cascade impactor, and 34% for an eight-stage Andersen impactor. An approach is given to calculate the committed effective dose (CED) coefficient for PuO2 aerosol particles, compared to a corresponding aerodynamic diameter of CeO2 particles. With this approach, use of CeO2 as a surrogate for PuO2 material would follow a direct conversion based on a molar equivalent. In addition to the analytical information developed for this document, several US national labs have published articles about the use of CeO2 as a PuO2 surrogate. Different physical and chemical aspects were considered by these investigators, including thermal properties, ceramic formulations, cold pressing, sintering, molecular reactions, and mass loss in high temperature gas flows. All of those US national lab studies recommended the use of CeO2 as a surrogate material for PuO2.

  3. Water corrosion test of oxide dispersion strengthened (ODS) steel claddings

    International Nuclear Information System (INIS)

    Narita, Takeshi; Ukai, Shigeharu; Kaito, Takeji; Ohtsuka, Satoshi; Matsuda, Yasushi

    2006-07-01

    As a part of feasibility study of ODS steel cladding, its water corrosion resistance was examined under water pool condition. Although addition of Cr is effective for preventing water corrosion, excessive Cr addition leads to embrittlement due to the Cr-rich α' precipitate formation. In the ODS steel developed by the Japan Atomic Energy Agency (JAEA), the Cr content is controlled in 9Cr-ODS martensite and 12Cr-ODS ferrite. In this study, water corrosion test was conducted for these ODS steels, and their results were compared with that of conventional austenitic stainless steel and ferritic-martensitic stainless steel. Following results were obtained in this study. (1) Corrosion rate of 9Cr-ODS martensitic and 12Cr-ODS ferritic steel are significantly small and no pitting was observed. Thus, these ODS steels have superior resistance for water corrosion under the condition of 60degC and pH8-12. (2) It was showed that 9Cr-ODS martensitic steel and 12Cr-ODS ferritic steel have comparable water corrosion resistance to that of PNC316 and PNC-FMS at 60degC for 1,000h under varying pH of 8, 10. Water corrosion resistance of these alloys is slightly larger than that of PNC316 and PNC-FMS at pH12 without significant difference of appearance and uneven condition. (author)

  4. Oxidative and antioxidative status in the testes of rats with acute epididymitis.

    Science.gov (United States)

    Kaya, Mete; Boleken, Mehmet Emin; Zeyrek, Fadile; Ozardali, Ilyas; Kanmaz, Turan; Erel, Ozcan; Yücesan, Selçuk

    2006-01-01

    Epididymitis is an inflammation or infection of the epididymis, a convoluted duct that lies on the posterior surface of the testicle. Oxidative stress due to excessive production of reactive oxygen species in epididymitis, impaired antioxidant defense mechanisms, or both, precipitates a range of pathologies that are currently believed to negatively affect the male reproductive function. How oxidative stress affects the testes is still unknown. We aimed to investigate the oxidative and antioxidative status of testes of rats with unilateral acute Escherichia coli epididymitis. The study included 36 male Wistar albino rats which were divided into three groups. In the epididymitis group (n = 12), an E. coli suspension was injected into the right ductus deferens of rats, and the same amount of saline was injected in the saline groups (n = 12). No surgery was performed in the control group (n = 12) for baseline values. Rats were sacrificed after 24 h and the epididymis and testes removed. The infection was confirmed by histopathologic evaluation and microbiological tests. The oxidative status of testes was evaluated by measuring myeloperoxidase (MPO) activity, and antioxidative status was evaluated by measuring total antioxidant response (TAR) and total antioxidant capacity levels (TAC). MPO activity in both the ipsilateral and contralateral testes of the epididymitis group was significantly higher than those of the saline and control groups (p antioxidants. 2006 S. Karger AG, Basel.

  5. Size distributions of aerosols produced from substitute materials by the Laskin cold DOP aerosol generator

    International Nuclear Information System (INIS)

    Hinds, W.; Macher, J.; First, M.W.

    1981-01-01

    Test aerosols of di(2-ethylhexyl)phthalate (DOP) produced by Laskin nozzle aerosol generators are widely used for in-place filter testing and respirator fit testing. Concern for the health effects of this material has led to a search for substitute materials for test aerosols. Aerosols were generated with a Laskin generator and diluted 6000-fold with clean air. Size distributions were measured for DOP, di(2-ethylhexyl)sebecate, polyethylene glycol, mineral oil, and corn oil aerosols with a PMS ASAS-X optical particle counter. Distributions were slightly bimodal with count median diameters from 0.22 to 0.30 μm. Size distributions varied little with aerosol material, operating pressure, or liquid level. Mineral oil and corn oil gave the best agreement with the DOP size distribution

  6. Solid Oxide Cell and Stack Testing, Safety and Quality Assurance (SOCTESQA)

    DEFF Research Database (Denmark)

    Auer, C.; Lang, M.; Couturier, K.

    2015-01-01

    In the EU-funded project “SOCTESQA” partners from Europe and Singapore are working together to develop uniform and industry wide test procedures and protocols for solid oxide cells and stacks SOC cell/stack assembly. New application fields which are based on the operation of the SOC cell/stack as......In the EU-funded project “SOCTESQA” partners from Europe and Singapore are working together to develop uniform and industry wide test procedures and protocols for solid oxide cells and stacks SOC cell/stack assembly. New application fields which are based on the operation of the SOC cell...

  7. Dissolution of uranium oxide materials in simulated lung fluid

    International Nuclear Information System (INIS)

    Scripsick, R.C.; Soderholm, S.C.

    1985-01-01

    Depleted uranium (DU) oxide aerosols prepared in the laboratory and collected in the field were tested to characterize their dissolution in simulated lung fluid and to determine how dissolution is affected by aerosol preparation. DU, a by-product of the uranium fuel cycle, has been selected by the US military for use in several types of munitions. During development, manufacture, testing, and use of these munitions, opportunities exist for inhalation exposure to various (usually oxide) aerosol forms of DU. The hazard potential associated with such exposures is closely related to the chemical form, the size of the DU aerosol material, and its dissolution properties. Five DU sample materials produced by exposing uranium alloy penetrators to certain controlled oxidation atmospheres were studied (oxidation temperatures ranged from 500 to 900 0 C). In addition, two DU sample materials collected in the field were provided by the US Air Force. All sample materials were generated as aerosols and the respirable fraction was separated and collected. Data suggest that under some conditions a rapidly dissolving U 3 O 8 fraction may be formed concurrent with the production of UO 2

  8. Biaxial (Tension-Torsion) Testing of an Oxide/Oxide Ceramic Matrix Composite

    Science.gov (United States)

    2013-03-01

    11 3.1 NextelTM 720/AS Dogbone and Straightsided Specimen Layups . . . . . . . . 15 3.2 Prepreg processing steps of NextelTM 720/AS composite...the laminate in the test section, used for producing circum- ferential or axial stresses, should be minimized to avoid adding a high radial stress...provided fabrication process in Figure 3.2. The process followed the fabric, prepreg , and layup process versus the fiber tow and filament winding

  9. Behavior of aerosols in a steam-air environment

    International Nuclear Information System (INIS)

    Adams, R.E.; Tobias, M.L.; Longest, A.W.

    1985-01-01

    The behavior of aerosols assumed to be characteristic of those generated during light water reactor (LWR) accident sequences and released into containment is being studied in the Nuclear Safety Pilot Plant (NSPP) which is located at the Oak Ridge National Laboratory (ORNL). The program plan for the NSPP aerosol project provides for the study of the behavior, within containment, of simulated LWR accident aerosols emanating from fuel, reactor core structural materials, and from concrete-molten core materials interactions. The aerodynamic behavior of each of these aerosols was studied individually to establish its characteristics; current experiments involve mixtures of these aerosols to establish their interaction and collective behavior within containment. Tests have been conducted with U 3 O 8 aerosols, Fe 2 O 3 aerosols, and concrete aerosols in an environment of either dry air [relative humidity (RH) less than 20%] or steam-air [relative humidity (RH) approximately 100%] with aerosol mass concentration being the primary experimental variable

  10. Aerosol scrubbers

    International Nuclear Information System (INIS)

    Sheely, W.F.

    1986-01-01

    The Submerged Gravel Scrubber is an air cleaning system developed by the Department of Energy's Liquid Metal Reactor Program. The Scrubber System has been patented by the Department of Energy. This technology is being transferred to industry by the DOE. Its basic principles can be adapted for individual applications and the commercialized version can be used to perform a variety of tasks. The gas to be cleaned is percolated through a continuously washed gravel bed. The passage of the gas through the gravel breaks the stream into many small bubbles rising in a turbulent body of water. These conditions allow very highly efficient removal of aerosols from the gas

  11. In situ measurement of methane oxidation in groundwater by using natural-gradient tracer tests

    International Nuclear Information System (INIS)

    Smith, R.L.; Howes, B.L.; Garabedian, S.P.

    1991-01-01

    Methane oxidation was measured in an unconfined sand and gravel aquifer (Cape Cod, Mass.) by using in situ natural-gradient tracer tests at both a pristine, oxygenated site and an anoxic, sewage-contaminated site. The tracer sites were equipped with multilevel sampling devices to create target grids of sampling points; the injectate was prepared with groundwater from the tracer site to maintain the same geochemical conditions. Methane oxidation was calculated from breakthrough curves of methane relative to halide and inert gas (hexafluoroethane) tracers and was confirmed by the appearance of 13 C-enriched carbon dioxide in experiments in which 13 C-enriched methane was used as the tracer. A V max for methane oxidation could be calculated when the methane concentration was sufficiently high to result in zero-order kinetics throughout the entire transport interval. Methane breakthrough curves could be simulated by modifying a one-dimensional advection-dispersion transport model to include a Michaelis-Menten-based consumption term for methane oxidation. The K m values for methane oxidation that gave the best match for the breakthrough curve peaks were 6.0 and 9.0 μM for the uncontaminated and contaminated sites, respectively. Natural-gradient tracer tests are a promising approach for assessing microbial processes and for testing in situ bioremediation potential in groundwater systems

  12. Status of test results of electrochemical organic oxidation of a tank 241-SY-101 simulated waste

    International Nuclear Information System (INIS)

    Colby, S.A.

    1994-06-01

    This report presents scoping test results of an electrochemical waste pretreatment process to oxidize organic compounds contained in the Hanford Site's radioactive waste storage tanks. Electrochemical oxidation was tested on laboratory scale to destroy organics that are thought to pose safety concerns, using a nonradioactive, simulated tank waste. Minimal development work has been applied to alkaline electrochemical organic destruction. Most electrochemical work has been directed towards acidic electrolysis, as in the metal purification industry, and silver catalyzed oxidation. Alkaline electrochemistry has traditionally been associated with the following: (1) inefficient power use, (2) electrode fouling, and (3) solids handling problems. Tests using a laboratory scale electrochemical cell oxidized surrogate organics by applying a DC electrical current to the simulated tank waste via anode and cathode electrodes. The analytical data suggest that alkaline electrolysis oxidizes the organics into inorganic carbonate and smaller carbon chain refractory organics. Electrolysis treats the waste without adding chemical reagents and at ambient conditions of temperature and pressure. Cell performance was not affected by varying operating conditions and supplemental electrolyte additions

  13. Aerosol Chemical Composition and its Effects on Cloud-Aerosol Interactions during the 2007 CHAPS Experiment

    Science.gov (United States)

    Lee, Y.; Alexander, L.; Newburn, M.; Jayne, J.; Hubbe, J.; Springston, S.; Senum, G.; Andrews, B.; Ogren, J.; Kleinman, L.; Daum, P.; Berg, L.; Berkowitz, C.

    2007-12-01

    Chemical composition of submicron aerosol particles was determined using an Aerodyne Time-of-Flight Aerosol Mass Spectrometer (AMS) outfitted on the DOE G-1 aircraft during the Cumulus Humilis Aerosol Processing Study (CHAPS) conducted in Oklahoma City area in June 2007. The primary objective of CHAPS was to investigate the effects of urban emissions on cloud aerosol interactions as a function of processing of the emissions. Aerosol composition was typically determined at three different altitudes: below, in, and above cloud, in both upwind and downwind regions of the urban area. Aerosols were sampled from an isokinetic inlet with an upper size cut-off of ~1.5 micrometer. During cloud passages, the AMS also sampled particles that were dried from cloud droplets collected using a counter-flow virtual impactor (CVI) sampler. The aerosol mass concentrations were typically below 10 microgram per cubic meter, and were dominated by organics and sulfate. Ammonium was often less than required for complete neutralization of sulfate. Aerosol nitrate levels were very low. We noted that nitrate levels were significantly enhanced in cloud droplets compared to aerosols, most likely resulting from dissolution of gaseous nitric acid. Organic to sulfate ratios appeared to be lower in cloud droplets than in aerosols, suggesting cloud condensation nuclei properties of aerosol particles might be affected by loading and nature of the organic components in aerosols. In-cloud formation of sulfate was considered unimportant because of the very low SO2 concentration in the region. A detailed examination of the sources of the aerosol organic components (based on hydrocarbons determined using a proton transfer reaction mass spectrometer) and their effects on cloud formation as a function of atmospheric processing (based on the degree of oxidation of the organic components) will be presented.

  14. Improved ASTM G72 Test Method for Ensuring Adequate Fuel-to-Oxidizer Ratios

    Science.gov (United States)

    Juarez, Alfredo; Harper, Susana Tapia

    2016-01-01

    The ASTM G72/G72M-15 Standard Test Method for Autogenous Ignition Temperature of Liquids and Solids in a High-Pressure Oxygen-Enriched Environment is currently used to evaluate materials for the ignition susceptibility driven by exposure to external heat in an enriched oxygen environment. Testing performed on highly volatile liquids such as cleaning solvents has proven problematic due to inconsistent test results (non-ignitions). Non-ignition results can be misinterpreted as favorable oxygen compatibility, although they are more likely associated with inadequate fuel-to-oxidizer ratios. Forced evaporation during purging and inadequate sample size were identified as two potential causes for inadequate available sample material during testing. In an effort to maintain adequate fuel-to-oxidizer ratios within the reaction vessel during test, several parameters were considered, including sample size, pretest sample chilling, pretest purging, and test pressure. Tests on a variety of solvents exhibiting a range of volatilities are presented in this paper. A proposed improvement to the standard test protocol as a result of this evaluation is also presented. Execution of the final proposed improved test protocol outlines an incremental step method of determining optimal conditions using increased sample sizes while considering test system safety limits. The proposed improved test method increases confidence in results obtained by utilizing the ASTM G72 autogenous ignition temperature test method and can aid in the oxygen compatibility assessment of highly volatile liquids and other conditions that may lead to false non-ignition results.

  15. Black carbon aerosol mixing state, organic aerosols and aerosol optical properties over the United Kingdom

    Science.gov (United States)

    McMeeking, G. R.; Morgan, W. T.; Flynn, M.; Highwood, E. J.; Turnbull, K.; Haywood, J.; Coe, H.

    2011-09-01

    Black carbon (BC) aerosols absorb sunlight thereby leading to a positive radiative forcing and a warming of climate and can also impact human health through their impact on the respiratory system. The state of mixing of BC with other aerosol species, particularly the degree of internal/external mixing, has been highlighted as a major uncertainty in assessing its radiative forcing and hence its climate impact, but few in situ observations of mixing state exist. We present airborne single particle soot photometer (SP2) measurements of refractory BC (rBC) mass concentrations and mixing state coupled with aerosol composition and optical properties measured in urban plumes and regional pollution over the United Kingdom. All data were obtained using instrumentation flown on the UK's BAe-146-301 large Atmospheric Research Aircraft (ARA) operated by the Facility for Airborne Atmospheric Measurements (FAAM). We measured sub-micron aerosol composition using an aerosol mass spectrometer (AMS) and used positive matrix factorization to separate hydrocarbon-like (HOA) and oxygenated organic aerosols (OOA). We found a higher number fraction of thickly coated rBC particles in air masses with large OOA relative to HOA, higher ozone-to-nitrogen oxides (NOx) ratios and large concentrations of total sub-micron aerosol mass relative to rBC mass concentrations. The more ozone- and OOA-rich air masses were associated with transport from continental Europe, while plumes from UK cities had higher HOA and NOx and fewer thickly coated rBC particles. We did not observe any significant change in the rBC mass absorption efficiency calculated from rBC mass and light absorption coefficients measured by a particle soot absorption photometer despite observing significant changes in aerosol composition and rBC mixing state. The contributions of light scattering and absorption to total extinction (quantified by the single scattering albedo; SSA) did change for different air masses, with lower SSA

  16. Black carbon aerosol mixing state, organic aerosols and aerosol optical properties over the UK

    Science.gov (United States)

    McMeeking, G. R.; Morgan, W. T.; Flynn, M.; Highwood, E. J.; Turnbull, K.; Haywood, J.; Coe, H.

    2011-05-01

    Black carbon (BC) aerosols absorb sunlight thereby leading to a positive radiative forcing and a warming of climate and can also impact human health through their impact on the respiratory system. The state of mixing of BC with other aerosol species, particularly the degree of internal/external mixing, has been highlighted as a major uncertainty in assessing its radiative forcing and hence its climate impact, but few in situ observations of mixing state exist. We present airborne single particle soot photometer (SP2) measurements of refractory BC (rBC) mass concentrations and mixing state coupled with aerosol composition and optical properties measured in urban plumes and regional pollution over the UK. All data were obtained using instrumentation flown on the UK's BAe-146-301 large Atmospheric Research Aircraft (ARA) operated by the Facility for Airborne Atmospheric Measurements (FAAM). We measured sub-micron aerosol composition using an aerosol mass spectrometer (AMS) and used positive matrix factorization to separate hydrocarbon-like (HOA) and oxygenated organic aerosols (OOA). We found a higher number fraction of thickly coated rBC particles in air masses with large OOA relative to HOA, higher ozone-to-nitrogen oxides (NOx) ratios and large concentrations of total sub-micron aerosol mass relative to rBC mass concentrations. The more ozone- and OOA-rich air masses were associated with transport from continental Europe, while plumes from UK cities had higher HOA and NOx and fewer thickly coated rBC particles. We did not observe any significant change in the rBC mass absorption efficiency calculated from rBC mass and light absorption coefficients measured by a particle soot absorption photometer despite observing significant changes in aerosol composition and rBC mixing state. The contributions of light scattering and absorption to total extinction (quantified by the single scattering albedo; SSA) did change for different air masses, with lower SSA observed in

  17. Black carbon aerosol mixing state, organic aerosols and aerosol optical properties over the United Kingdom

    Directory of Open Access Journals (Sweden)

    G. R. McMeeking

    2011-09-01

    Full Text Available Black carbon (BC aerosols absorb sunlight thereby leading to a positive radiative forcing and a warming of climate and can also impact human health through their impact on the respiratory system. The state of mixing of BC with other aerosol species, particularly the degree of internal/external mixing, has been highlighted as a major uncertainty in assessing its radiative forcing and hence its climate impact, but few in situ observations of mixing state exist. We present airborne single particle soot photometer (SP2 measurements of refractory BC (rBC mass concentrations and mixing state coupled with aerosol composition and optical properties measured in urban plumes and regional pollution over the United Kingdom. All data were obtained using instrumentation flown on the UK's BAe-146-301 large Atmospheric Research Aircraft (ARA operated by the Facility for Airborne Atmospheric Measurements (FAAM. We measured sub-micron aerosol composition using an aerosol mass spectrometer (AMS and used positive matrix factorization to separate hydrocarbon-like (HOA and oxygenated organic aerosols (OOA. We found a higher number fraction of thickly coated rBC particles in air masses with large OOA relative to HOA, higher ozone-to-nitrogen oxides (NOx ratios and large concentrations of total sub-micron aerosol mass relative to rBC mass concentrations. The more ozone- and OOA-rich air masses were associated with transport from continental Europe, while plumes from UK cities had higher HOA and NOx and fewer thickly coated rBC particles. We did not observe any significant change in the rBC mass absorption efficiency calculated from rBC mass and light absorption coefficients measured by a particle soot absorption photometer despite observing significant changes in aerosol composition and rBC mixing state. The contributions of light scattering and absorption to total extinction (quantified by the single scattering albedo; SSA did change for

  18. Evolution of aerosol downwind of a major highway

    Science.gov (United States)

    Liggio, J.; Staebler, R. M.; Brook, J.; Li, S.; Vlasenko, A. L.; Sjostedt, S. J.; Gordon, M.; Makar, P.; Mihele, C.; Evans, G. J.; Jeong, C.; Wentzell, J. J.; Lu, G.; Lee, P.

    2010-12-01

    Primary aerosol from traffic emissions can have a considerable impact local and regional scale air quality. In order to assess the effect of these emissions and of future emissions scenarios, air quality models are required which utilize emissions representative of real world conditions. Often, the emissions processing systems which provide emissions input for the air quality models rely on laboratory testing of individual vehicles under non-ambient conditions. However, on the sub-grid scale particle evolution may lead to changes in the primary emitted size distribution and gas-particle partitioning that are not properly considered when the emissions are ‘instantly mixed’ within the grid volume. The affect of this modeling convention on model results is not well understood. In particular, changes in organic gas/particle partitioning may result in particle evaporation or condensation onto pre-existing aerosol. The result is a change in the particle distribution and/or an increase in the organic mass available for subsequent gas-phase oxidation. These effects may be missing from air-quality models, and a careful analysis of field data is necessary to quantify their impact. A study of the sub-grid evolution of aerosols (FEVER; Fast Evolution of Vehicle Emissions from Roadways) was conducted in the Toronto area in the summer of 2010. The study included mobile measurements of particle size distributions with a Fast mobility particle sizer (FMPS), aerosol composition with an Aerodyne aerosol mass spectrometer (AMS), black carbon (SP2, PA, LII), VOCs (PTR-MS) and other trace gases. The mobile laboratory was used to measure the concentration gradient of the emissions at perpendicular distances from the highway as well as the physical and chemical evolution of the aerosol. Stationary sites at perpendicular distances and upwind from the highway also monitored the particle size distribution. In addition, sonic anemometers mounted on the mobile lab provided measurements of

  19. Capstone Depleted Uranium Aerosols: Generation and Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Parkhurst, MaryAnn; Szrom, Fran; Guilmette, Ray; Holmes, Tom; Cheng, Yung-Sung; Kenoyer, Judson L.; Collins, John W.; Sanderson, T. Ellory; Fliszar, Richard W.; Gold, Kenneth; Beckman, John C.; Long, Julie

    2004-10-19

    In a study designed to provide an improved scientific basis for assessing possible health effects from inhaling depleted uranium (DU) aerosols, a series of DU penetrators was fired at an Abrams tank and a Bradley fighting vehicle. A robust sampling system was designed to collect aerosols in this difficult environment and continuously monitor the sampler flow rates. Aerosols collected were analyzed for uranium concentration and particle size distribution as a function of time. They were also analyzed for uranium oxide phases, particle morphology, and dissolution in vitro. The resulting data provide input useful in human health risk assessments.

  20. Methods study of homogeneity and stability test from cerium oxide CRM candidate

    International Nuclear Information System (INIS)

    Samin; Susanna TS

    2016-01-01

    The methods study of homogeneity and stability test from cerium oxide CRM candidate has been studied based on ISO 13258 and KAN DP. 01. 34. The purpose of this study was to select the test method homogeneity and stability tough on making CRM cerium oxide. Prepared 10 sub samples of cerium oxide randomly selected types of analytes which represent two compounds, namely CeO_2 and La_2O_3. At 10 sub sample is analyzed CeO_2 and La_2O_3 contents in duplicate with the same analytical methods, by the same analyst, and in the same laboratory. Data analysis results calculated statistically based on ISO 13528 and KAN DP.01.34. According to ISO 13528 Cerium Oxide samples said to be homogeneous if Ss ≤ 0.3 σ and is stable if | Xr – Yr | ≤ 0.3 σ. In this study, the data of homogeneity test obtained CeO_2 is Ss = 2.073 x 10-4 smaller than 0.3 σ (0.5476) and the stability test obtained | Xr - Yr | = 0.225 and the price is < 0.3 σ. Whereas for La_2O_3, the price for homogeneity test obtained Ss = 1.649 x 10-4 smaller than 0.3 σ (0.4865) and test the stability of the price obtained | Xr - Yr | = 0.2185 where the price is < 0.3 σ. Compared with the method from KAN, a sample of cerium oxide has also been homogenized for Fcalc < Ftable and stable, because | Xi - Xhm | < 0.3 x n IQR. Provided that the results of the evaluation homogeneity and stability test from CeO_2 CRM candidate test data were processed using statistical methods ISO 13528 is not significantly different with statistical methods from KAN DP.01.34, which together meet the requirements of a homogeneous and stable. So the test method homogeneity and stability test based on ISO 13528 can be used to make CRM cerium oxide. (author)

  1. Determination of the bonding strength in solid oxide fuel cells' interfaces by Schwickerath crack initiation test

    DEFF Research Database (Denmark)

    Boccaccini, D. N.; Sevecek, O.; Frandsen, Henrik Lund

    2017-01-01

    An adaptation of the Schwickerath crack initiation test (ISO 9693) was used to determine the bonding strength between an anode support and three different cathodes with a solid oxide fuel cell interconnect. Interfacial elemental characterization of the interfaces was carried out by SEM/EDS analys...

  2. Aerosols and the lungs

    International Nuclear Information System (INIS)

    1987-01-01

    The lectures of the colloquium are discussed in summary form. There were 5 lectures on aerosol deposition, 5 on aerosol elimination, 7 on toxicology, and 7 on the uses of aerosols in medical therapy. In some cases aerosols with radioactive labels were used. Several lectures reviewed the kinetics and toxicology of airborne environmental pollutants. (MG) [de

  3. Influence of ionizing radiation on the catalytic properties of oxide catalysts tested by hydrogen peroxide decomposition

    International Nuclear Information System (INIS)

    Mucka, V.

    1987-01-01

    Results of a study of some physical and catalytic properties of different oxide catalysts as affected by ionizing radiation (γ, n, e - ) and tested by the decomposition of hydrogen peroxide in aqueous solution are presented in this paper. The oxidation state of the active component present on the catalyst surface was found to be one of the most sensitive properties to the ionizing radiation. Changes of this state induced by γ-irradiation were found to be positive in most cases; electron pre-irradiation of the oxides leads, as a rule, to negative effects and the effects of neutron irradiation may be positive or negative. On the other hand, changes in the catalytic activity of the oxides after γ-or electron-irradiation seem to be mostly negative and positive, respectively; the effects of fast neutrons seem to vary here. Neither quantitative or qualitative correlation was found between the radiation-induced changes in these two quantities. The results give evidence that ionizing radiation principally affects the surface concentration of the catalytic sites. Both the character and magnitude of the changes in surface oxidation abilities and in catalytic activities of the oxide catalysts seem to be dependent upon the actual state of the catalyst surface. (author)

  4. Performance Testing of a Photocatalytic Oxidation Module for Spacecraft Cabin Atmosphere Revitalization

    Science.gov (United States)

    Perry, Jay L.; Abney, Morgan B.; Frederick, Kenneth R.; Scott, Joseph P.; Kaiser, Mark; Seminara, Gary; Bershitsky, Alex

    2011-01-01

    Photocatalytic oxidation (PCO) is a candidate process technology for use in high volumetric flow rate trace contaminant control applications in sealed environments. The targeted application for PCO as applied to crewed spacecraft life support system architectures is summarized. Technical challenges characteristic of PCO are considered. Performance testing of a breadboard PCO reactor design for mineralizing polar organic compounds in a spacecraft cabin atmosphere is described. Test results are analyzed and compared to results reported in the literature for comparable PCO reactor designs.

  5. Solid Oxide Cell and Stack Testing, Safety and Quality Assurance (SOCTESQA)

    OpenAIRE

    Auer, Corinna; Lang, Michael; Couturier, Karine; Nielsen, Eva Ravn; Mc Phail, Stephen; Tsotridis, Georgios; FU, Qingxi; Chan, Siew Hwa

    2015-01-01

    The market penetration of fuel and electrolysis cell energy systems in Europe requires the development of reliable assessment, testing and prediction of performance and durability of solid oxide cells and stacks (SOC). To advance in this field the EU-project “SOCTESQA” was launched in May 2014. Partners from different countries in Europe and one external party from Singapore are working together to develop uniform and industry wide test procedures and protocols for SOC cell/stack assembly. In...

  6. Radiative and temperature effects of aerosol simulated by the COSMO-Ru model for different atmospheric conditions and their testing against ground-based measurements and accurate RT simulations

    Science.gov (United States)

    Chubarova, Nataly; Poliukhov, Alexei; Shatunova, Marina; Rivin, Gdali; Becker, Ralf; Muskatel, Harel; Blahak, Ulrich; Kinne, Stefan; Tarasova, Tatiana

    2017-04-01

    We use the operational Russian COSMO-Ru weather forecast model (Ritter and and Geleyn, 1991) with different aerosol input data for the evaluation of radiative and temperature effects of aerosol in different atmospheric conditions. Various aerosol datasets were utilized including Tegen climatology (Tegen et al., 1997), updated Macv2 climatology (Kinne et al., 2013), Tanre climatology (Tanre et al., 1984) as well as the MACC data (Morcrette et al., 2009). For clear sky conditions we compare the radiative effects from the COSMO-Ru model over Moscow (55.7N, 37.5E) and Lindenberg/Falkenberg sites (52.2N, 14.1E) with the results obtained using long-term aerosol measurements. Additional tests of the COSMO RT code were performed against (FC05)-SW model (Tarasova T.A. and Fomin B.A., 2007). The overestimation of about 5-8% of COSMO RT code was obtained. The study of aerosol effect on temperature at 2 meters has revealed the sensitivity of about 0.7-1.1 degree C per 100 W/m2 change in shortwave net radiation due to aerosol variations. We also discuss the radiative impact of urban aerosol properties according to the long-term AERONET measurements in Moscow and Moscow suburb as well as long-term aerosol trends over Moscow from the measurements and Macv2 dataset. References: Kinne, S., O'Donnel D., Stier P., et al., J. Adv. Model. Earth Syst., 5, 704-740, 2013. Morcrette J.-J.,O. Boucher, L. Jones, eet al, J.GEOPHYS. RES.,VOL. 114, D06206, doi:10.1029/2008JD011235, 2009. Ritter, B. and Geleyn, J., Monthly Weather Review, 120, 303-325, 1992. Tanre, D., Geleyn, J., and Slingo, J., A. Deepak Publ., Hampton, Virginia, 133-177, 1984. Tarasova, T., and Fomin, B., Journal of Atmospheric and Oceanic Technology, 24, 1157-1162, 2007. Tegen, I., Hollrig, P., Chin, M., et al., Journal of Geophysical Research- Atmospheres, 102, 23895-23915, 1997.

  7. An acellular assay to assess the genotoxicity of complex mixtures of organic pollutants bound on size segregated aerosol. Part II: oxidative damage to DNA

    Czech Academy of Sciences Publication Activity Database

    Rössner ml., Pavel; Topinka, Jan; Hovorka, J.; Milcová, Alena; Schmuczerová, Jana; Kroužek, J.; Šrám, Radim

    2010-01-01

    Roč. 198, č. 3 (2010), s. 312-316 ISSN 0378-4274 R&D Projects: GA MŠk 2B08005 Grant - others:GA MŽP(CZ) SP/1A3/149/08 Institutional research plan: CEZ:AV0Z50390512 Keywords : air pollution * particulate matter * atmospheric aerosol Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 3.581, year: 2010

  8. Landscape fires dominate terrestrial natural aerosol - climate feedbacks

    Science.gov (United States)

    Scott, C.; Arnold, S.; Monks, S. A.; Asmi, A.; Paasonen, P.; Spracklen, D. V.

    2017-12-01

    The terrestrial biosphere is an important source of natural aerosol including landscape fire emissions and secondary organic aerosol (SOA) formed from biogenic volatile organic compounds (BVOCs). Atmospheric aerosol alters the Earth's climate by absorbing and scattering radiation (direct radiative effect; DRE) and by perturbing the properties of clouds (aerosol indirect effect; AIE). Natural aerosol sources are strongly controlled by, and can influence, climate; giving rise to potential natural aerosol-climate feedbacks. Earth System Models (ESMs) include a description of some of these natural aerosol-climate feedbacks, predicting substantial changes in natural aerosol over the coming century with associated radiative perturbations. Despite this, the sensitivity of natural aerosols simulated by ESMs to changes in climate or emissions has not been robustly tested against observations. Here we combine long-term observations of aerosol number and a global aerosol microphysics model to assess terrestrial natural aerosol-climate feedbacks. We find a strong positive relationship between the summertime anomaly in observed concentration of particles greater than 100 nm diameter and the anomaly in local air temperature. This relationship is reproduced by the model and driven by variability in dynamics and meteorology, as well as natural sources of aerosol. We use an offline radiative transfer model to determine radiative effects due to changes in two natural aerosol sources: landscape fire and biogenic SOA. We find that interannual variability in the simulated global natural aerosol radiative effect (RE) is negatively related to the global temperature anomaly. The magnitude of global aerosol-climate feedback (sum of DRE and AIE) is estimated to be -0.15 Wm-2 K-1 for landscape fire aerosol and -0.06 Wm-2 K-1 for biogenic SOA. These feedbacks are comparable in magnitude, but opposite in sign to the snow albedo feedback, highlighting the need for natural aerosol feedbacks to

  9. Results of Testing the Relative Oxidizing Hazard of Wipes and KMI Zeolite

    Energy Technology Data Exchange (ETDEWEB)

    Ams, Bridget Elaine [Los Alamos National Laboratory

    2017-05-09

    This report includes the results from testing performed on the relative oxidizing hazard of a number of organic sorbing wipe materials, as well as KMI zeolite. These studies were undertaken to address a need by the Los Alamos National Laboratory (LANL) Hazardous Materials Management group, which requires a material that can sorb small spills in a glovebox without creating a disposal hazard due to the potential for oxidation reactions, as requested in Request for Testing of Wipes and Zeolite for Los Alamos National Laboratory Hazardous Materials Group (NPl-7) (NPl-7-17-002) and Request for Testing of Chamois Material for Los Alamos National Laboratory Hazardous Materials Group (NPl-7) (NPl-7-17-005). This set oftests is a continuation of previous testing described in Results from Preparation and Testing of Sorbents Mixed with (DWT-RPT-003), which provided data for the Waste Isolation Pilot Plant's Basis of Knowledge. The Basis of Knowledge establishes criteria for evaluating transuranic (TRU) waste that contains oxidizing chemicals.

  10. Oxide-metal corium-concrete interaction test in the Vulcano facility

    Energy Technology Data Exchange (ETDEWEB)

    Journeau, Ch.; Piluso, P.; Haquet, J.F.; Saretta, S.; Boccaccio, E.; Bonnet, J.M. [CEA Cadarache, Severe Accident Mastery experimental Lab. (DEN/DTN/STRI/LMA), 13 - Saint Paul lez Durance (France)

    2007-07-01

    Corium is likely to melt through the vessel and interact with the reactor pit concrete. Corium is made of a UO{sub 2}-rich oxidic part, in which most of the decay heat is dissipated, and of a metallic part, mainly molten steel. An experiment has been set up in the Vulcano facility in which oxidic and metallic mixtures are molten in separate furnaces and poured in a concrete cavity. Induction heating is provided to the pool upper part thanks to shielding coils, so that, in case of stratification, the lighter oxidic corium-concrete mixture receives most of the power. Pre-calculations with the TOLBIAC-ICB corium-concrete interaction code based on the phase segregation model have provided valuable information for the dimensioning of this test: a thick metallic layer (>10 kg or 4 cm) has been chosen in order to obtain significant cavity ablation profiles depending on the selected heat transfer and stratification models. Stratification of the two liquid phases is predicted to occur in less than 10 minutes. In September 2006, the experiment was performed in the Vulcano facility. The corium was made of about 15 kg of steel at 1700 C and 30 kg of oxides (70% UO{sub 2}, 16 % ZrO{sub 2} and 14% concrete load) above 2000 C. It was poured in a limestone-rich concrete. This concrete type was selected for the first test, since the ablation is isotropic except for the initial transient, during oxidic corium-concrete interaction tests. 32 kW of induction power have been provided to the pool during the 4-hour test. The destruction of in-concrete thermocouples indicates that ablation was first mainly radial then became isotropic. This is quite similar to the ablation progression observed during previous tests with oxidic corium interacting with this type of concrete. Important 'volcanic activity' has been observed at the corium pool surface, compared to the previous oxidic corium experiments at Vulcano. (authors)

  11. Atmospheric and aerosol chemistry

    Energy Technology Data Exchange (ETDEWEB)

    McNeill, V. Faye [Columbia Univ., New York, NY (United States). Dept. of Chemical Engineering; Ariya, Parisa A. (ed.) [McGill Univ. Montreal, QC (Canada). Dept. of Chemistry; McGill Univ. Montreal, QC (Canada). Dept. of Atmospheric and Oceanic Sciences

    2014-09-01

    This series presents critical reviews of the present position and future trends in modern chemical research. Short and concise reports on chemistry, each written by the world renowned experts. Still valid and useful after 5 or 10 years. More information as well as the electronic version of the whole content available at: springerlink.com. Christian George, Barbara D'Anna, Hartmut Herrmann, Christian Weller, Veronica Vaida, D. J. Donaldson, Thorsten Bartels-Rausch, Markus Ammann Emerging Areas in Atmospheric Photochemistry. Lisa Whalley, Daniel Stone, Dwayne Heard New Insights into the Tropospheric Oxidation of Isoprene: Combining Field Measurements, Laboratory Studies, Chemical Modelling and Quantum Theory. Neil M. Donahue, Allen L. Robinson, Erica R. Trump, Ilona Riipinen, Jesse H. Kroll Volatility and Aging of Atmospheric Organic Aerosol. P. A. Ariya, G. Kos, R. Mortazavi, E. D. Hudson, V. Kanthasamy, N. Eltouny, J. Sun, C. Wilde Bio-Organic Materials in the Atmosphere and Snow: Measurement and Characterization V. Faye McNeill, Neha Sareen, Allison N. Schwier Surface-Active Organics in Atmospheric Aerosols.

  12. Atmospheric and aerosol chemistry

    International Nuclear Information System (INIS)

    McNeill, V. Faye; Ariya, Parisa A.; McGill Univ. Montreal, QC

    2014-01-01

    This series presents critical reviews of the present position and future trends in modern chemical research. Short and concise reports on chemistry, each written by the world renowned experts. Still valid and useful after 5 or 10 years. More information as well as the electronic version of the whole content available at: springerlink.com. Christian George, Barbara D'Anna, Hartmut Herrmann, Christian Weller, Veronica Vaida, D. J. Donaldson, Thorsten Bartels-Rausch, Markus Ammann Emerging Areas in Atmospheric Photochemistry. Lisa Whalley, Daniel Stone, Dwayne Heard New Insights into the Tropospheric Oxidation of Isoprene: Combining Field Measurements, Laboratory Studies, Chemical Modelling and Quantum Theory. Neil M. Donahue, Allen L. Robinson, Erica R. Trump, Ilona Riipinen, Jesse H. Kroll Volatility and Aging of Atmospheric Organic Aerosol. P. A. Ariya, G. Kos, R. Mortazavi, E. D. Hudson, V. Kanthasamy, N. Eltouny, J. Sun, C. Wilde Bio-Organic Materials in the Atmosphere and Snow: Measurement and Characterization V. Faye McNeill, Neha Sareen, Allison N. Schwier Surface-Active Organics in Atmospheric Aerosols.

  13. Oxidation of aluminum alloy cladding for research and test reactor fuel

    Science.gov (United States)

    Kim, Yeon Soo; Hofman, G. L.; Robinson, A. B.; Snelgrove, J. L.; Hanan, N.

    2008-08-01

    The oxide thicknesses on aluminum alloy cladding were measured for the test plates from irradiation tests RERTR-6 and 7A in the ATR (advanced test reactor). The measured thicknesses were substantially lower than those of test plates with similar power from other reactors available in the literature. The main reason is believed to be due to the lower pH (pH 5.1-5.3) of the primary coolant water in the ATR than in the other reactors (pH 5.9-6.5) for which we have data. An empirical model for oxide film thickness predictions on aluminum alloy used as fuel cladding in the test reactors was developed as a function of irradiation time, temperature, surface heat flux, pH, and coolant flow rate. The applicable ranges of pH and coolant flow rates cover most research and test reactors. The predictions by the new model are in good agreement with the in-pile test data available in the literature as well as with the RERTR test data measured in the ATR.

  14. Oxidation of aluminum alloy cladding for research and test reactor fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeon Soo [Argonne National Laboratory, Nuclear Engineering, 9700 South Cass Avenue, Argonne, IL 60439 (United States)], E-mail: yskim@anl.gov; Hofman, G.L. [Argonne National Laboratory, Nuclear Engineering, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Robinson, A.B. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States); Snelgrove, J.L.; Hanan, N. [Argonne National Laboratory, Nuclear Engineering, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

    2008-08-31

    The oxide thicknesses on aluminum alloy cladding were measured for the test plates from irradiation tests RERTR-6 and 7A in the ATR (advanced test reactor). The measured thicknesses were substantially lower than those of test plates with similar power from other reactors available in the literature. The main reason is believed to be due to the lower pH (pH 5.1-5.3) of the primary coolant water in the ATR than in the other reactors (pH 5.9-6.5) for which we have data. An empirical model for oxide film thickness predictions on aluminum alloy used as fuel cladding in the test reactors was developed as a function of irradiation time, temperature, surface heat flux, pH, and coolant flow rate. The applicable ranges of pH and coolant flow rates cover most research and test reactors. The predictions by the new model are in good agreement with the in-pile test data available in the literature as well as with the RERTR test data measured in the ATR.

  15. Evolution of oxidation in soybean oil and its biodiesel under the conditions of the oxidation stability test

    Directory of Open Access Journals (Sweden)

    Pereira, G. G.

    2013-12-01

    Full Text Available The objective of this study was to know the evolution of the oxidation of soybean oil and biodiesel under the conditions of the oxidation stability test (110 °C using the Rancimat apparatus. Samples were analyzed at different periods of time until the end of the induction period. The analytical determinations related to the changes in oxidation include peroxide value, anisidine value, natural tocopherols and polar compounds. Acid value, kinematic viscosity, polymers and ester content were also analyzed because of their relevance in the evaluation of biodiesel quality. Results showed that only peroxide value and the group of polar compounds including hydroperoxides, i.e. oxidized monomeric TAG in the oil and oxidized monomeric FAME in the biodiesel increased significantly during the early oxidation stage. The end of the induction period was marked by a rapid increase in polymerization compounds and the exhaustion of tocopherols. Significant changes in acid value, viscosity and ester content were only observed after the end of the induction period.El objetivo de este estudio fue conocer la evolución de la oxidación del aceite de soja y de su biodiesel a 110 °C en las condiciones del método estándar para la determinación de la estabilidad oxidativa, usando el aparato Rancimat. Las muestras se analizaron en diferentes períodos de tiempo hasta que el período de inducción fue sobrepasado. Se determinaron los índices de peróxidos y anisidina, los tocoferoles y los compuestos polares cuyos cambios están relacionados con el desarrollo de la alteración oxidativa. Además, fueron determinados el índice de acidez, la viscosidad y el contenido en ésteres, de interés en el análisis de la calidad del biodiesel. Los resultados indicaron que sólo el índice de peróxidos y el grupo de compuestos polares que incluye los hidroperóxidos (triglicéridos oxidados monómeros en el aceite y ésteres metílicos oxidados monómeros en el biodiesel

  16. Fluorescent biological aerosol particles measured with the Waveband Integrated Bioaerosol Sensor WIBS-4: laboratory tests combined with a one year field study

    Directory of Open Access Journals (Sweden)

    E. Toprak

    2013-01-01

    Full Text Available In this paper bioaerosol measurements conducted with the Waveband Integrated Bioaerosol Sensor mark 4 (WIBS-4 are presented. The measurements comprise aerosol chamber characterization experiments and a one-year ambient measurement period at a semi-rural site in South Western Germany. This study aims to investigate the sensitivity of WIBS-4 to biological and non-biological aerosols and detection of biological particles in the ambient aerosol. Several types of biological and non-biological aerosol samples, including fungal spores, bacteria, mineral dust, ammonium sulphate, combustion soot, and fluorescent polystyrene spheres, were analyzed by WIBS-4 in the laboratory. The results confirm the sensitivity of the ultraviolet light-induced fluorescence (UV-LIF method to biological fluorophores and show the good discrimination capabilities of the two excitation wavelengths/detection wavebands method applied in WIBS-4. However, a weak cross-sensitivity to non-biological fluorescent interferers remains and is discussed in this paper.

    All the laboratory studies have been undertaken in order to prepare WIBS-4 for ambient aerosol measurements. According to the one-year ambient aerosol study, number concentration of fluorescent biological aerosol particles (FBAP show strong seasonal and diurnal variability. The highest number concentration of FBAP was measured during the summer term and decreased towards the winter period when colder and drier conditions prevail. Diurnal FBAP concentrations start to increase after sunset and reach maximum values during the late night and early morning hours. On the other hand, the total aerosol number concentration was almost always higher during daytime than during nighttime and a sharp decrease after sunset was observed. There was no correlation observed between the FBAP concentration and the meteorological parameters temperature, precipitation, wind direction and wind speed. However, a clear correlation was

  17. Aerosol typing - key information from aerosol studies

    Science.gov (United States)

    Mona, Lucia; Kahn, Ralph; Papagiannopoulos, Nikolaos; Holzer-Popp, Thomas; Pappalardo, Gelsomina

    2016-04-01

    Aerosol typing is a key source of aerosol information from ground-based and satellite-borne instruments. Depending on the specific measurement technique, aerosol typing can be used as input for retrievals or represents an output for other applications. Typically aerosol retrievals require some a priori or external aerosol type information. The accuracy of the derived aerosol products strongly depends on the reliability of these assumptions. Different sensors can make use of different aerosol type inputs. A critical review and harmonization of these procedures could significantly reduce related uncertainties. On the other hand, satellite measurements in recent years are providing valuable information about the global distribution of aerosol types, showing for example the main source regions and typical transport paths. Climatological studies of aerosol load at global and regional scales often rely on inferred aerosol type. There is still a high degree of inhomogeneity among satellite aerosol typing schemes, which makes the use different sensor datasets in a consistent way difficult. Knowledge of the 4d aerosol type distribution at these scales is essential for understanding the impact of different aerosol sources on climate, precipitation and air quality. All this information is needed for planning upcoming aerosol emissions policies. The exchange of expertise and the communication among satellite and ground-based measurement communities is fundamental for improving long-term dataset consistency, and for reducing aerosol type distribution uncertainties. Aerosol typing has been recognized as one of its high-priority activities of the AEROSAT (International Satellite Aerosol Science Network, http://aero-sat.org/) initiative. In the AEROSAT framework, a first critical review of aerosol typing procedures has been carried out. The review underlines the high heterogeneity in many aspects: approach, nomenclature, assumed number of components and parameters used for the

  18. Opportunities for mixed oxide fuel testing in the advanced test reactor to support plutonium disposition

    International Nuclear Information System (INIS)

    Terry, W.K.; Ryskamp, J.M.; Sterbentz, J.W.

    1995-08-01

    Numerous technical issues must be resolved before LWR operating licenses can be amended to allow the use of MOX fuel. These issues include the following: (1) MOX fuel fabrication process verification; (2) Whether and how to use burnable poisons to depress MOX fuel initial reactivity, which is higher than that of urania; (3) The effects of WGPu isotopic composition; (4) The feasibility of loading MOX fuel with plutonia content up to 7% by weight; (5) The effects of americium and gallium in WGPu; (6) Fission gas release from MOX fuel pellets made from WGPu; (7) Fuel/cladding gap closure; (8) The effects of power cycling and off-normal events on fuel integrity; (9) Development of radial distributions of burnup and fission products; (10) Power spiking near the interfaces of MOX and urania fuel assemblies; and (11) Fuel performance code validation. The Advanced Test Reactor (ATR) at the Idaho National Engineering Laboratory possesses many advantages for performing tests to resolve most of the issues identified above. We have performed calculations to show that the use of hafnium shrouds can produce spectrum adjustments that will bring the flux spectrum in ATR test loops into a good approximation to the spectrum anticipated in a commercial LWR containing MOX fuel while allowing operation of the test fuel assemblies near their optimum values of linear heat generation rate. The ATR would be a nearly ideal test bed for developing data needed to support applications to license LWRs for operation with MOX fuel made from weapons-grade plutonium. The requirements for planning and implementing a test program in the ATR have been identified. The facilities at Argonne National Laboratory-West can meet all potential needs for pre- and post-irradiation examination that might arise in a MOX fuel qualification program

  19. The Plinius/Colima CA-U3 test on fission-product aerosol release over a VVER-type corium pool

    International Nuclear Information System (INIS)

    Journeau, Ch.; Piluso, P.; Correggio, P.; Godin-Jacqmin, L.

    2007-01-01

    In a hypothetical case of severe accident in a PWR type VVER-440, a complex corium pool could be formed and fission products could be released. In order to study aerosols release in terms of mechanisms, kinetics, nature or quantity, and to better precise the source term of VVER-440, a series of experiments have been performed in the Colima facility and the test Colima CA-U3 has been successfully performed thanks to technological modifications to melt a prototypical corium at 2760 C degrees. Specific instrumentation has allowed us to follow the evolution of the corium melt and the release, transport and deposition of the fission products. The main conclusions are: -) there is a large release of Cr, Te, Sr, Pr and Rh (>95%w), -) there is a significant release of Fe (50%w), -) there is a small release of Ba, Ce, La, Nb, Nd and Y (<90%w), -) there is a very small release of U in proportion (<5%w) but it is one of the major released species in mass, and -) there is no release of Zr. The Colima experimental results are consistent with previous experiments on irradiated fuels except for Ba, Fe and U releases. (A.C.)

  20. Supplemental dietary phytosterin protects against 4-nitrophenol-induced oxidative stress and apoptosis in rat testes

    Directory of Open Access Journals (Sweden)

    Yonghui Zhang

    2015-01-01

    Full Text Available 4-Nitrophenol (PNP, is generally regarded as an environmental endocrine disruptor (EED. Phytosterin (PS, a new feed additive, possesses highly efficient antioxidant activities. The transcription factor, nuclear factor-erythroid 2-related factor 2 (Nrf2, is an important regulator of cellular oxidative stress. Using rats, this study examined PNP-induced testicular oxidative damage and PS-mediated protection against that damage. The generation of MDA and H2O2 upon PNP and PS treatment was milder than that upon treatment with PNP alone. This mitigation was accompanied by partially reversed changes in SOD, CAT, GSH and GSH-Px. Moreover, PNP significantly reduced the caudal epididymal sperm counts and serum testosterone levels. Typical morphological changes were also observed in the testes of PNP-treated animals. PNP reduced the transcriptional level of Nrf2, as evaluated by RT-PCR, but it promoted the dissociation from the Nrf2 complex, stabilization and translocation into the nucleus, as evaluated by immunohistochemistry and Western blotting. In addition, PNP enhanced the Nrf2-dependent gene expression of heme oxygenase-1 (HO-1 and glutamate–cysteine ligase catalytic subunit (GCLC. These results suggest that the Nrf2 pathway plays an important role in PNP-induced oxidative damage and that PS possesses modulatory effects on PNP-induced oxidative damage in rat testes.

  1. Meteorological support for aerosol radiometers: special aerosol sources

    Energy Technology Data Exchange (ETDEWEB)

    Belkina, S.K.; Zalmanzon, Yu.E.; Kuznetsov, Yu.V.; Fertman, D.E.

    1988-07-01

    A new method is described for transfer of the measure of unit volume activity of radioactive aerosols from the state special standard to the working instruments in the stage of regular operation. The differences from existing methods are examined. The principal distinction of the new method is the possibility of direct (rather than through the conversion factor) determination and subsequent testing of the fundamental meteorological characteristics of the instrument by means of special aerosol sources, which fosters a significant reduction in individual components of the indicated errors.

  2. Cloud condensation nuclei activity of aliphatic amine secondary aerosol

    Science.gov (United States)

    Aliphatic amines can form secondary aerosol via oxidation with atmospheric radicals (e.g. hydroxyl radical and nitrate radical). The resulting particle composition can contain both secondary organic aerosol (SOA) and inorganic salts. The fraction of organic to inorganic materials in the particulate ...

  3. Generation and characterization of biological aerosols for laser measurements

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Yung-Sung; Barr, E.B.

    1995-12-01

    Concerns for proliferation of biological weapons including bacteria, fungi, and viruses have prompted research and development on methods for the rapid detection of biological aerosols in the field. Real-time instruments that can distinguish biological aerosols from background dust would be especially useful. Sandia National Laboratories (SNL) is developing a laser-based, real-time instrument for rapid detection of biological aerosols, and ITRI is working with SNL scientists and engineers to evaluate this technology for a wide range of biological aerosols. This paper describes methods being used to generate the characterize the biological aerosols for these tests. In summary, a biosafe system has been developed for generating and characterizing biological aerosols and using those aerosols to test the SNL laser-based real-time instrument. Such tests are essential in studying methods for rapid detection of airborne biological materials.

  4. Standard test method for measurement of oxidation-reduction potential (ORP) of soil

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This test method covers a procedure and related test equipment for measuring oxidation-reduction potential (ORP) of soil samples removed from the ground. 1.2 The procedure in Section 9 is appropriate for field and laboratory measurements. 1.3 Accurate measurement of oxidation-reduction potential aids in the analysis of soil corrosivity and its impact on buried metallic structure corrosion rates. 1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  5. The application of the barrier-type anodic oxidation method to thickness testing of aluminum films

    Science.gov (United States)

    Chen, Jianwen; Yao, Manwen; Xiao, Ruihua; Yang, Pengfei; Hu, Baofu; Yao, Xi

    2014-09-01

    The thickness of the active metal oxide film formed from a barrier-type anodizing process is directly proportional to its formation voltage. The thickness of the consumed portion of the metal film is also corresponding to the formation voltage. This principle can be applied to the thickness test of the metal films. If the metal film is growing on a dielectric substrate, when the metal film is exhausted in an anodizing process, because of the high electrical resistance of the formed oxide film, a sudden increase of the recorded voltage during the anodizing process would occur. Then, the thickness of the metal film can be determined from this voltage. As an example, aluminum films are tested and discussed in this work. This method is quite simple and is easy to perform with high precision.

  6. Unspeciated organic emissions from combustion sources and their influence on the secondary organic aerosol budget in the United States

    Science.gov (United States)

    Secondary organic aerosol (SOA) formed from the atmospheric oxidation of nonmethane organic gases (NMOG) is a major contributor to atmospheric aerosol mass. Emissions and smog chamber experiments were performed to investigate SOA formation from gasoline vehicles, diesel vehicles,...

  7. Global direct radiative forcing by process-parameterized aerosol optical properties

    Science.gov (United States)

    KirkevâG, Alf; Iversen, Trond

    2002-10-01

    A parameterization of aerosol optical parameters is developed and implemented in an extended version of the community climate model version 3.2 (CCM3) of the U.S. National Center for Atmospheric Research. Direct radiative forcing (DRF) by monthly averaged calculated concentrations of non-sea-salt sulfate and black carbon (BC) is estimated. Inputs are production-specific BC and sulfate from [2002] and background aerosol size distribution and composition. The scheme interpolates between tabulated values to obtain the aerosol single scattering albedo, asymmetry factor, extinction coefficient, and specific extinction coefficient. The tables are constructed by full calculations of optical properties for an array of aerosol input values, for which size-distributed aerosol properties are estimated from theory for condensation and Brownian coagulation, assumed distribution of cloud-droplet residuals from aqueous phase oxidation, and prescribed properties of the background aerosols. Humidity swelling is estimated from the Köhler equation, and Mie calculations finally yield spectrally resolved aerosol optical parameters for 13 solar bands. The scheme is shown to give excellent agreement with nonparameterized DRF calculations for a wide range of situations. Using IPCC emission scenarios for the years 2000 and 2100, calculations with an atmospheric global cliamte model (AFCM) yield a global net anthropogenic DRF of -0.11 and 0.11 W m-2, respectively, when 90% of BC from biomass burning is assumed anthropogenic. In the 2000 scenario, the individual DRF due to sulfate and BC has separately been estimated to -0.29 and 0.19 W m-2, respectively. Our estimates of DRF by BC per BC mass burden are lower than earlier published estimates. Some sensitivity tests are included to investigate to what extent uncertain assumptions may influence these results.

  8. Understanding overpressure in the FAA aerosol can test by C3H2F3Br (2-BTP)✩

    Science.gov (United States)

    Linteris, Gregory Thomas; Babushok, Valeri Ivan; Pagliaro, John Leonard; Burgess, Donald Raymond; Manion, Jeffrey Alan; Takahashi, Fumiaki; Katta, Viswanath Reddy; Baker, Patrick Thomas

    2018-01-01

    Thermodynamic equilibrium calculations, as well as perfectly-stirred reactor (PSR) simulations with detailed reaction kinetics, are performed for a potential halon replacement, C3H2F3Br (2-BTP, C3H2F3Br, 2-Bromo-3,3,3-trifluoropropene), to understand the reasons for the unexpected enhanced combustion rather than suppression in a mandated FAA test. The high pressure rise with added agent is shown to depend on the amount of agent, and is well-predicted by an equilibrium model corresponding to stoichiometric reaction of fuel, oxygen, and agent. A kinetic model for the reaction of C3H2F3Br in hydrocarbon-air flames has been applied to understand differences in the chemical suppression behavior of C3H2F3Br vs. CF3Br in the FAA test. Stirred-reactor simulations predict that in the conditions of the FAA test, the inhibition effectiveness of C3H2F3Br at high agent loadings is relatively insensitive to the overall stoichiometry (for fuel-lean conditions), and the marginal inhibitory effect of the agent is greatly reduced, so that the mixture remains flammable over a wide range of conditions. Most important, the flammability of the agent-air mixtures themselves (when compressively preheated), can support low-strain flames which are much more difficult to extinguish than the easy-to extinguish, high-strain primary fireball from the impulsively released fuel mixture. Hence, the exothermic reaction of halogenated hydrocarbons in air should be considered in other situations with strong ignition sources and low strain flows, especially at preheated conditions. PMID:29628525

  9. Understanding overpressure in the FAA aerosol can test by C3H2F3Br (2-BTP).

    Science.gov (United States)

    Linteris, Gregory Thomas; Babushok, Valeri Ivan; Pagliaro, John Leonard; Burgess, Donald Raymond; Manion, Jeffrey Alan; Takahashi, Fumiaki; Katta, Viswanath Reddy; Baker, Patrick Thomas

    2016-05-01

    Thermodynamic equilibrium calculations, as well as perfectly-stirred reactor (PSR) simulations with detailed reaction kinetics, are performed for a potential halon replacement, C 3 H 2 F 3 Br (2-BTP, C 3 H 2 F 3 Br, 2-Bromo-3,3,3-trifluoropropene), to understand the reasons for the unexpected enhanced combustion rather than suppression in a mandated FAA test. The high pressure rise with added agent is shown to depend on the amount of agent, and is well-predicted by an equilibrium model corresponding to stoichiometric reaction of fuel, oxygen, and agent. A kinetic model for the reaction of C 3 H 2 F 3 Br in hydrocarbon-air flames has been applied to understand differences in the chemical suppression behavior of C 3 H 2 F 3 Br vs. CF 3 Br in the FAA test. Stirred-reactor simulations predict that in the conditions of the FAA test, the inhibition effectiveness of C 3 H 2 F 3 Br at high agent loadings is relatively insensitive to the overall stoichiometry (for fuel-lean conditions), and the marginal inhibitory effect of the agent is greatly reduced, so that the mixture remains flammable over a wide range of conditions. Most important, the flammability of the agent-air mixtures themselves (when compressively preheated), can support low-strain flames which are much more difficult to extinguish than the easy-to extinguish, high-strain primary fireball from the impulsively released fuel mixture. Hence, the exothermic reaction of halogenated hydrocarbons in air should be considered in other situations with strong ignition sources and low strain flows, especially at preheated conditions.

  10. The intercomparison of aerosol codes

    International Nuclear Information System (INIS)

    Dunbar, I.H.; Fermandjian, J.; Gauvain, J.

    1988-01-01

    The behavior of aerosols in a reactor containment vessel following a severe accident could be an important determinant of the accident source term to the environment. Various processes result in the deposition of the aerosol onto surfaces within the containment, from where they are much less likely to be released. Some of these processes are very sensitive to particle size, so it is important to model the aerosol growth processes: agglomeration and condensation. A number of computer codes have been written to model growth and deposition processes. They have been tested against each other in a series of code comparison exercises. These exercises have investigated sensitivities to physical and numerical assumptions and have also proved a useful means of quality control for the codes. Various exercises in which code predictions are compared with experimental results are now under way

  11. Characterization of urban aerosol using aerosol mass spectrometry and proton nuclear magnetic resonance spectroscopy

    Science.gov (United States)

    Cleveland, M. J.; Ziemba, L. D.; Griffin, R. J.; Dibb, J. E.; Anderson, C. H.; Lefer, B.; Rappenglück, B.

    2012-07-01

    Particulate matter was measured during August and September of 2006 in Houston as part of the Texas Air Quality Study II Radical and Aerosol Measurement Project. Aerosol size and composition were determined using an Aerodyne quadrupole aerosol mass spectrometer. Aerosol was dominated by sulfate (4.1 ± 2.6 μg m-3) and organic material (5.5 ± 4.0 μg m-3), with contributions of organic material from both primary (˜32%) and secondary (˜68%) sources. Secondary organic aerosol appears to be formed locally. In addition, 29 aerosol filter samples were analyzed using proton nuclear magnetic resonance (1H NMR) spectroscopy to determine relative concentrations of organic functional groups. Houston aerosols are less oxidized than those observed elsewhere, with smaller relative contributions of carbon-oxygen double bonds. These particles do not fit 1H NMR source apportionment fingerprints for identification of secondary, marine, and biomass burning organic aerosol, suggesting that a new fingerprint for highly urbanized and industrially influenced locations be established.

  12. Behavior of mixed-oxide fuel elements during the TOPI-1E transient overpower test

    International Nuclear Information System (INIS)

    Tsai, H.; Neimark, L.A.; Yamamoto, K.; Hirai, K.; Shikakura, S.

    1993-12-01

    A slow-ramp, extended overpower transient test was conducted on a group of nineteen preirradiated mixed-oxide fuel elements in EBR-II. During the transient two of the test elements with high-density fuel and tempered martensitic cladding (PNC-FMS) breached at an overpower of ∼75%. Fuel elements with austenitic claddings (D9, PNC316, and PNC150), many with aggressive design features and high burnups, survived the overpower transient and incurred little or no cladding strain. Fuel elements with annual fuel or heterogeneous fuel columns also behaved well

  13. Preliminary testing of a planar converter with uranium oxide pellets in the emitter

    International Nuclear Information System (INIS)

    Miskolczy, G.; Lieb, D.P.; Hatch, G.L.

    1992-01-01

    Nuclear reactor thermionic space power systems incorporating thermionic fuel element generally use refractory metal emitters, which contain the nuclear fuel. The purpose of the current work is to determine the effect, if any, of the diffusion of uranium oxide fuel through chemically vapor deposited (CVD) tungsten on converter performance. This paper describes the preliminary testing of the converter to assess the converter performance before any significant diffusion takes place. In testing, the emitter temperature was 1800 K and the collector temperature was varied from 1000 K to 1070 K. Experiments also examined pressure versus loading characteristics of the graphite

  14. Laboratory testing of ozone oxidation of Hanford Site waste from Tank 241-SY-101

    International Nuclear Information System (INIS)

    Delegard, C.H.; Stubbs, A.M.; Bolling, S.D.

    1993-01-01

    Ozone was investigated as a reagent to oxidize and destroy organic species present in simulated and genuine waste from Hanford Site Tank 241-SY-101 (Tank 101-SY). Two high-shear mixing apparatus were tested to perform the gas-to-solution mass transfer necessary to achieve efficient use of the ozone reagent. Oxidations of nitrite (to form nitrate) and organic species were observed. The organics oxidized to form carbonate and oxalate as well as nitrate and nitrogen gas from nitrogen associated with the organic. oxidations of metal species also were observed directly or inferred by solubilities. The chemical reaction stoichiometries were consistent with reduction of one oxygen atom per ozone molecule. Acetate, oxalate, and formate were found to comprise about 40% of the genuine waste's total organic carbon (TOC) concentration. Ozonation was found to be chemically feasible for destroying organic species (except oxalate) present in the wastes in Tank 101-SY. The simulated waste formulation used in these studies credibly modelled the ozonation behavior of the genuine waste

  15. AEROSOL AND GAS MEASUREMENT

    Science.gov (United States)

    Measurements provide fundamental information for evaluating and managing the impact of aerosols on air quality. Specific measurements of aerosol concentration and their physical and chemical properties are required by different users to meet different user-community needs. Befo...

  16. Hazard classification for the supercritical water oxidation test bed. Revision 1

    International Nuclear Information System (INIS)

    Ramos, A.G.

    1994-10-01

    A hazard classification of ''routinely accepted by the public'' has been determined for the operation of the supercritical water oxidation test bed at the Idaho National Engineering Laboratory. This determination is based on the fact that the design and proposed operation meet or exceed appropriate national standards so that the risks are equivalent to those present in similar activities conducted in private industry. Each of the 17 criteria for hazards ''routinely accepted by the public,'' identified in the EG and G Idaho, Inc., Safety Manual, were analyzed. The supercritical water oxidation (SCWO) test bed will treat simulated mixed waste without the radioactive component. It will be designed to operate with eight test wastes. These test wastes have been chosen to represent a broad cross-section of candidate mixed wastes anticipated for storage or generation by DOE. In particular, the test bed will generate data to evaluate the ability of the technology to treat chlorinated waste and other wastes that have in the past caused severe corrosion and deposition in SCWO reactors

  17. In vitro biological test of resistance to oxidation: application to identification of irradiated food

    International Nuclear Information System (INIS)

    Blache, D.; Prost, M.; Raffi, J.

    1991-01-01

    The test presented here for the identification of ionized food is a direct application of a biological test of resistance to oxidation, put on for an evaluation of antioxidant properties of pharmaceutic molecules and for the study of free radicals in biology. Consequently, the main part of this datum is relative to this biological test. We only point out, when necessary, how we plan to use it for food items. Our aim in this paper is to present a simple biological test (SPIRAL Patent Pending) to measure the total anti oxidative defence status of individuals utilizing some easy to handle cells: circulating cells. In this presentation, we only limited to red blood cells, but any cell could be used after suitable adaptation of the procedure. The first experiments carried out on irradiated foods are promising, even for foodstuffs in liquid state, but we have surely to do a lot of new ones in order to improve the specificity of this test with regard to irradiation and to define with which food it can be used. (9 refs; 15 figs)

  18. Data acquisition testing in supercritical water oxidation using machine cutting oils and metals

    International Nuclear Information System (INIS)

    Garcia, K.M.

    1996-01-01

    The Department of Energy, the Navy, and SERDP provided funding for an extensive series of testing of a Supercritical Water Oxidation (SCWO) system. The goal of the testing was to create performance data on the process when dealing with highly chlorinated wastes containing heavy metals, and radionuclides. The testing was performed in a MODAR vessel oxidizer. Performance was measured by the ability of the process to achieve greater than 99.99% destruction of the organic content, to partition the metals and radionuclide surrogates for mass balance, and survive the highly corrosive species in the effluent. The test data has shown that these goals were accomplished. 30 gal/day of highly chlorinated machine cutting oil was treated for 130 hrs. There were no significant corrosion or solids handling problems. This machine cutting oil, TRIM reg-sign SOL was chosen by DOE for its complex nature and has proven to be one of the more refractory organic feeds encountered by MODAR. The Navy provided 8 waste streams collected from their shore facilities operation. These paints varied in solids content with wastes such as paint chips, and adhesives. The ninth test run was with all 8 series of wastes combined. The MODAR system successfully treated all of these waste streams providing performance data on the ability of SCWO to treat difficult sludges

  19. Facility of aerosol filtration

    Energy Technology Data Exchange (ETDEWEB)

    Duverger de Cuy, G; Regnier, J

    1975-04-18

    Said invention relates to a facility of aerosol filtration, particularly of sodium aerosols. Said facility is of special interest for fast reactors where sodium fires involve the possibility of high concentrations of sodium aerosols which soon clog up conventional filters. The facility intended for continuous operation, includes at the pre-filtering stage, means for increasing the size of the aerosol particles and separating clustered particles (cyclone separator).

  20. Modeling organic aerosol concentrations and properties during winter 2014 in the northwestern Mediterranean region

    OpenAIRE

    Chrit, Mounir; Sartelet, Karine; Sciare, Jean; Majdi, Marwa; Nicolas, José; Petit, Jean-Eudes; Dulac, François

    2018-01-01

    Organic aerosols are measured at a remote site (Ersa) on Corsica Cape in the northwestern Mediterranean basin during the Chemistry-Aerosol Mediterranean Experiment (CharMEx) winter campaign of 2014, when high organic concentrations from anthropogenic origin are observed. This work aims at representing the observed organic aerosol concentrations and properties (oxidation state) using the air-quality model Polyphemus with a surrogate approach for secondary organic aerosol (SOA) formation. Becau...

  1. Technical specification: Mixed-oxide pellets for the light-water reactor irradiation demonstration test

    International Nuclear Information System (INIS)

    Cowell, B.S.

    1997-06-01

    This technical specification is a Level 2 Document as defined in the Fissile Materials Disposition Program Light-Water Reactor Mixed-oxide Fuel Irradiation Test Project Plan. It is patterned after the pellet specification that was prepared by Atomic Energy of Canada, Limited, for use by Los Alamos National Laboratory in fabrication of the test fuel for the Parallex Project, adjusted as necessary to reflect the differences between the Canadian uranium-deuterium reactor and light-water reactor fuels. This specification and the associated engineering drawing are to be utilized only for preparation of test fuel as outlined in the accompanying Request for Quotation and for additional testing as directed by Oak Ridge National Laboratory or the Department of Energy

  2. Accelerated testing of solid oxide fuel cell stacks for micro combined heat and power application

    DEFF Research Database (Denmark)

    Hagen, Anke; Høgh, Jens Valdemar Thorvald; Barfod, Rasmus

    2015-01-01

    State-of-the-art (SoA) solid oxide fuel cell (SOFC) stacks are tested using profiles relevant for use in micro combined heat and power (CHP) units. Such applications are characterised by dynamic load profiles. In order to shorten the needed testing time and to investigate potential acceleration...... of degradation, the profiles are executed faster than required for real applications. Operation with fast load cycling, both using hydrogen and methane/steam as fuels, does not accelerate degradation compared to constant operation, which demonstrates the maturity of SoA stacks and enables transferring knowledge...... effect for long life-times than regular short time changes of operation. In order to address lifetime testing it is suggested to build a testing program consisting of defined modules that represent different application profiles, such as one module at constant conditions, followed by modules at one set...

  3. Two-dimensional interaction of oxidic corium with concretes: The VULCANO VB test series

    Energy Technology Data Exchange (ETDEWEB)

    Journeau, Christophe [CEA, DEN, STRI/LMA, Cadarache, F-13108 St Paul lez Durance (France)], E-mail: christophe.journeau@cea.fr; Piluso, Pascal; Haquet, Jean-Francois; Boccaccio, Eric; Saldo, Valerie; Bonnet, Jean-Michel; Malaval, Sophie; Carenini, Laure [CEA, DEN, STRI/LMA, Cadarache, F-13108 St Paul lez Durance (France); Brissonneau, Laurent [CEA, DEN, STPA/LPC, Cadarache, F-13108 St Paul lez Durance (France)

    2009-10-15

    Three two-dimensional Molten Core-Concrete Interaction tests have been conducted in the VULCANO facility with prototypic oxidic corium. The major finding is that for the two tests with silica-rich concrete, the ablation was anisotropic while it was isotropic for limestone-rich concrete. The cause of this behaviour is not yet well understood. Post Test Examinations have indicated that for the silica-rich concrete, the corium melt mixed specifically with mortar, while, for limestone-rich concretes, the analysed samples were in accordance with a corium-concrete mixing. The experimental results are described and compared to numerical codes. Separate Effect Tests with Artificial Concretes and prototypic corium are proposed to understand the phenomena governing the ablation geometry.

  4. Two-dimensional interaction of oxidic corium with concretes: The VULCANO VB test series

    International Nuclear Information System (INIS)

    Journeau, Christophe; Piluso, Pascal; Haquet, Jean-Francois; Boccaccio, Eric; Saldo, Valerie; Bonnet, Jean-Michel; Malaval, Sophie; Carenini, Laure; Brissonneau, Laurent

    2009-01-01

    Three two-dimensional Molten Core-Concrete Interaction tests have been conducted in the VULCANO facility with prototypic oxidic corium. The major finding is that for the two tests with silica-rich concrete, the ablation was anisotropic while it was isotropic for limestone-rich concrete. The cause of this behaviour is not yet well understood. Post Test Examinations have indicated that for the silica-rich concrete, the corium melt mixed specifically with mortar, while, for limestone-rich concretes, the analysed samples were in accordance with a corium-concrete mixing. The experimental results are described and compared to numerical codes. Separate Effect Tests with Artificial Concretes and prototypic corium are proposed to understand the phenomena governing the ablation geometry.

  5. Characterization of Halyomorpha halys (brown marmorated stink bug) biogenic volatile organic compound emissions and their role in secondary organic aerosol formation.

    Science.gov (United States)

    Solomon, Danielle; Dutcher, Dabrina; Raymond, Timothy

    2013-11-01

    The formation of aerosols is a key component in understanding cloud formation in the context of radiative forcings and global climate modeling. Biogenic volatile organic compounds (BVOCs) are a significant source of aerosols, yet there is still much to be learned about their structures, sources, and interactions. The aims of this project were to identify the BVOCs found in the defense chemicals of the brown marmorated stink bug Halymorpha halys and quantify them using gas chromatography-mass spectrometry (GC/MS) and test whether oxidation of these compounds by ozone-promoted aerosol and cloud seed formation. The bugs were tested under two conditions: agitation by asphyxiation and direct glandular exposure. Tridecane, 2(5H)-furanone 5-ethyl, and (E)-2-decenal were identified as the three most abundant compounds. H. halys were also tested in the agitated condition in a smog chamber. It was found that in the presence of 100-180 ppm ozone, secondary aerosols do form. A scanning mobility particle sizer (SMPS) and a cloud condensation nuclei counter (CCNC) were used to characterize the secondary aerosols that formed. This reaction resulted in 0.23 microg/ bug of particulate mass. It was also found that these secondary organic aerosol particles could act as cloud condensation nuclei. At a supersaturation of 1%, we found a kappa value of 0.09. Once regional populations of these stink bugs stablilize and the populations estimates can be made, the additional impacts of their contribution to regional air quality can be calculated.

  6. Influence of non-ideality on condensation to aerosol

    Directory of Open Access Journals (Sweden)

    S. Compernolle

    2009-02-01

    Full Text Available Secondary organic aerosol (SOA is a complex mixture of water and organic molecules. Its composition is determined by the presence of semi-volatile or non-volatile compounds, their saturation vapor pressure and activity coefficient. The activity coefficient is a non-ideality effect and is a complex function of SOA composition. In a previous publication, the detailed chemical mechanism (DCM for α-pinene oxidation and subsequent aerosol formation BOREAM was presented. In this work, we investigate with this DCM the impact of non-ideality by simulating smog chamber experiments for α-pinene degradation and aerosol formation and taking the activity coefficient into account of all molecules in the aerosol phase. Several versions of the UNIFAC method are tested for this purpose, and missing parameters for e.g. hydroperoxides and nitrates are inferred from fittings to activity coefficient data generated using the SPARC model. Alternative approaches to deal with these missing parameters are also tested, as well as an activity coefficient calculation method based on Hansen solubility parameters (HSP. It turns out that for most experiments, non-ideality has only a limited impact on the interaction between the organic molecules, and therefore on SOA yields and composition, when water uptake is ignored. The reason is that often, the activity coefficient is on average close to 1 and, specifically for high-VOC experiments, partitioning is not very sensitive on the activity coefficient because the equilibrium is shifted strongly towards condensation. Still, for ozonolysis experiments with low amounts of volatile organic carbon (low-VOC, the UNIFAC parameterization of Raatikainen et al. leads to significantly higher SOA yields (by up to a factor 1.6 compared to the ideal case and to other parameterizations. Water uptake is model dependent, in the order: ideal > UNIFAC-Raatikainen > UNIFAC-Peng > UNIFAC-Hansen ≈ UNIFAC-Magnussen ≈ UNIFAC-Ming. In the absence

  7. Aerosols and Climate

    Indian Academy of Sciences (India)

    Large warming by elevated aerosols · AERONET – Global network (NASA) · Slide 25 · Slide 26 · Slide 27 · Slide 28 · Slide 29 · Slide 30 · Slide 31 · Long-term trends - Trivandrum · Enhanced warming over Himalayan-Gangetic region · Aerosol Radiative Forcing Over India _ Regional Aerosol Warming Experiment ...

  8. Particle-size dependence of immersion freezing: Investigation of INUIT test aerosol particles with freely suspended water drops.

    Science.gov (United States)

    Diehl, Karoline; Debertshäuser, Michael; Eppers, Oliver; Jantsch, Evelyn; Mitra, Subir K.

    2014-05-01

    One goal of the research group INUIT (Ice Nuclei research UnIT) is to investigate the efficiencies of several test ice nuclei under comparable conditions but with different experimental techniques. In the present studies, two methods are used: the Mainz vertical wind tunnel and an acoustic levitator placed inside a cold chamber. In both cases drops are freely levitated, either at their terminal velocity in the wind tunnel updraft or around the nodes of a standing ultrasonic wave in the acoustic levitator. Thus, heat transfer conditions are well approximated, and wall contact effects on freezing as well as electrical charges of the drops are avoided. Drop radii are 370 μm and 1 mm, respectively. In the wind tunnel, drops are investigated at constant temperatures within a certain time period and the onset of freezing is observed directly. In the acoustic levitator, the drop temperature decreases during the experiments and is measured by an in-situ calibrated Infrared thermometer. The onset of freezing is indicated by a rapid rise of the drop surface temperature because of the release of latent heat. Investigated test ice nuclei are Snomax® as a proxy of biological particles and illite NX as well as K-feldspar as represents of mineral dust. The particle concentrations are 1 × 10-12 to 3 × 10-6 g Snomax® per drop and 5 × 10-9 to 5 × 10-5 g mineral dust per drop. Freezing temperatures are between -2 and -18° C in case of Snomax® and between -14 and -26° C in case of mineral dust. The lower the particle masses per drop the lower are the freezing temperatures. For similar particle concentrations in the drops, the median freezing temperatures determined by the two techniques agree well within the measurement errors. With the knowledge of the specific particle surface area of the mineral dusts, the results are interpreted also in terms of particle surface area per drop. Results from the wind tunnel experiments which are performed at constant temperatures indicate

  9. Technical test description of activities to determine the potential for spent fuel oxidation in a tuff repository

    International Nuclear Information System (INIS)

    Einziger, R.E.

    1985-06-01

    The potential change in the oxidation state of spent fuel during its residence in a repository must be known to evaluate its radionuclide retention capabilities. Once the container breaches, the spent fuel in a repository sited above the water table will be exposed to a moist air atmosphere at low temperatures. Thermodynamically, there is no reason why the fuel should not oxidize to a higher oxidation state under these conditions, given enough time. Depending on the rate of oxidation, higher oxides with potentially higher leach rates may eventually form or the cladding may even split open. If either of these oxidation effects occurs, the ability of spent fuel to retard radionuclide migration will be reduced. A technical test description is presented to study spent fuel oxidation at low temperatures characteristic of the post-container breach period and at high temperatures in a moist inert atmosphere characteristic of a sealed container with waterlogged fuel, early in the repository life. The approach taken will be to perform tests and evaluations to gain understanding of the operative oxidation mechanisms, to obtain oxidation rate data, and to make projections of potential long-term fuel oxidation states. Time and temperature dependence of existing models will be evaluated, and the dependence of the model projections on fuel variables will be determined. 27 refs., 7 figs., 4 tabs

  10. Testing of resveratrol microemulsion photostability and protective effect against UV induced oxidative stress.

    Science.gov (United States)

    Juškaitė, Vaida; Ramanauskienė, Kristina; Briedis, Vitalis

    2017-06-27

    Resveratrol is well known for its antioxidant activity and susceptibility to ultraviolet radiation. Development of formulations providing improved stability and relevant drug delivery of resveratrol is still a challenging task. The aim of this study was to determine protective characteristics of formulated microemulsions by evaluating photoisomerization of resveratrol and to investigate the effects of resveratrol on human keratinocyte cells under oxidative stress caused by ultraviolet radiation. Incorporation of resveratrol into microemulsions resulted in increased photostability of active compounds and the results demonstrated that photodegradation of resveratrol was significantly delayed. Results of biopharmaceutical evaluation in vitro demonstrated that up to 60 % of resveratrol was released from microemulsions within 6 hours under a constant release rate profile. In vivo biological testing confirmed the ability of resveratrol to protect cells from oxidative stress and to increase cell viability. It was concluded that microemulsions might be considered in the development of UV light sensitive compounds.

  11. Testing of resveratrol microemulsion photostability and protective effect against UV induced oxidative stress

    Directory of Open Access Journals (Sweden)

    Juškaitė Vaida

    2017-06-01

    Full Text Available Resveratrol is well known for its antioxidant activity and susceptibility to ultraviolet radiation. Development of formulations providing improved stability and relevant drug delivery of resveratrol is still a challenging task. The aim of this study was to determine protective characteristics of formulated microemulsions by evaluating photoisomerization of resveratrol and to investigate the effects of resveratrol on human keratinocyte cells under oxidative stress caused by ultraviolet radiation. Incorporation of resveratrol into microemulsions resulted in increased photostability of active compounds and the results demonstrated that photodegradation of resveratrol was significantly delayed. Results of biopharmaceutical evaluation in vitro demonstrated that up to 60 % of resveratrol was released from microemulsions within 6 hours under a constant release rate profile. In vivo biological testing confirmed the ability of resveratrol to protect cells from oxidative stress and to increase cell viability. It was concluded that microemulsions might be considered in the development of UV light sensitive compounds.

  12. Criteria for the spreading of oxide melts: Test series miniKATS-1 to -5

    International Nuclear Information System (INIS)

    Eppinger, B.; Fieg, G.; Massier, H.; Schuetz, W.; Stegmaier, U.; Stern, G.

    2001-09-01

    In a long series of larger spreading tests with high temperature oxide melts (KATS tests) many parameters have been varied which are influencing the spreading behaviour (viscosity, pouring rate, substratum of spreading surface, presence of water). In spite of an extensive instrumentation using different thermocouples, an infrared camera and several video cameras, only in very few cases the behaviour of the melt front at the very moment of immobilization could be detected in detail. Therefore in the additional miniKATS series five small scale (5 kg) spreading tests with oxide melts have been conducted to investigate the mechanical properties of the spreading front in the moment of immobilization. It turned out that in all cases the bulk of the melt at this moment was still liquid at a temperature close to the initial one. Depending on the initial melt properties two distinct phenomena have been observed which control the immobilization of the melt: the first phenomena is the crust formation at the surface, the crusts at the bottom combined with the crust at the surface of the melt. In the other case the whole melt front was still above the liquid temperature at the moment of immobilization. Here the surface tension was controlling the spreading, it was in balance with the driving gravitational force. In none of the test bulk freezing has been detected. (orig.)

  13. Standard test methods for chemical and mass spectrometric analysis of nuclear-grade gadolinium oxide (Gd2O3) powder

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 These test methods cover procedures for the chemical and mass spectrometric analysis of nuclear-grade gadolinium oxide powders to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Carbon by Direct CombustionThermal Conductivity C1408 Test Method for Carbon (Total) in Uranium Oxide Powders and Pellets By Direct Combustion-Infrared Detection Method Total Chlorine and Fluorine by Pyrohydrolysis Ion Selective Electrode C1502 Test Method for Determination of Total Chlorine and Fluorine in Uranium Dioxide and Gadolinium Oxide Loss of Weight on Ignition 7-13 Sulfur by CombustionIodometric Titration Impurity Elements by a Spark-Source Mass Spectrographic C761 Test Methods for Chemical, Mass Spectrometric, Spectrochemical,Nuclear, and Radiochemical Analysis of Uranium Hexafluoride C1287 Test Method for Determination of Impurities In Uranium Dioxide By Inductively Coupled Plasma Mass Spectrometry Gadolinium Content in Gadolinium Oxid...

  14. PILOT TESTING OF MERCURY OXIDATION CATALYSTS FOR UPSTREAM OF WET FGD SYSTEMS

    International Nuclear Information System (INIS)

    Gary M. Blythe

    2002-01-01

    The objective of this project is to demonstrate at pilot scale the use of solid honeycomb catalysts to promote the oxidation of elemental mercury in the flue gas from coal combustion. The project is being funded by the U.S. DOE National Energy Technology Laboratory under Cooperative Agreement DE-FC26-01NT41185. EPRI, Great River Energy (GRE), and City Public Service (CPS) of San Antonio are project co-funders. URS Group is the prime contractor. The mercury catalytic oxidation process under development uses catalyst materials applied to honeycomb substrates to promote the oxidation of elemental mercury in the flue gas from coal-fired power plants that have wet lime or limestone flue gas desulfurization (FGD) systems. Oxidized mercury is removed in the wet FGD absorbers and co-precipitates in a stable form with the byproducts from the FGD system. The co-precipitated mercury does not appear to adversely affect the disposal or reuse properties of the FGD byproduct. The current project will test previously identified, effective catalyst materials at a larger, pilot scale and in a commercial form, so as to provide engineering data for future full-scale designs. The pilot-scale tests will continue for up to 14 months at each of two sites to provide longer-term catalyst life data. This is the first full reporting period for the subject Cooperative Agreement. During this period, most of the project efforts were related to project initiation and planning. There is no significant technical progress to report for the current period

  15. Coupling aerosol surface and bulk chemistry with a kinetic double layer model (K2-SUB: oxidation of oleic acid by ozone

    Directory of Open Access Journals (Sweden)

    C. Pfrang

    2010-05-01

    Full Text Available We present a kinetic double layer model coupling aerosol surface and bulk chemistry (K2-SUB based on the PRA framework of gas-particle interactions (Pöschl-Rudich-Ammann, 2007. K2-SUB is applied to a popular model system of atmospheric heterogeneous chemistry: the interaction of ozone with oleic acid. We show that our modelling approach allows de-convoluting surface and bulk processes, which has been a controversial topic and remains an important challenge for the understanding and description of atmospheric aerosol transformation. In particular, we demonstrate how a detailed treatment of adsorption and reaction at the surface can be coupled to a description of bulk reaction and transport that is consistent with traditional resistor model formulations.

    From literature data we have derived a consistent set of kinetic parameters that characterise mass transport and chemical reaction of ozone at the surface and in the bulk of oleic acid droplets. Due to the wide range of rate coefficients reported from different experimental studies, the exact proportions between surface and bulk reaction rates remain uncertain. Nevertheless, the model results suggest an important role of chemical reaction in the bulk and an approximate upper limit of ~10−11 cm2 s−1 for the surface reaction rate coefficient. Sensitivity studies show that the surface accommodation coefficient of the gas-phase reactant has a strong non-linear influence on both surface and bulk chemical reactions. We suggest that K2-SUB may be used to design, interpret and analyse future experiments for better discrimination between surface and bulk processes in the oleic acid-ozone system as well as in other heterogeneous reaction systems of atmospheric relevance.

  16. Aerosol Climate Time Series in ESA Aerosol_cci

    Science.gov (United States)

    Popp, Thomas; de Leeuw, Gerrit; Pinnock, Simon

    2016-04-01

    Within the ESA Climate Change Initiative (CCI) Aerosol_cci (2010 - 2017) conducts intensive work to improve algorithms for the retrieval of aerosol information from European sensors. Meanwhile, full mission time series of 2 GCOS-required aerosol parameters are completely validated and released: Aerosol Optical Depth (AOD) from dual view ATSR-2 / AATSR radiometers (3 algorithms, 1995 - 2012), and stratospheric extinction profiles from star occultation GOMOS spectrometer (2002 - 2012). Additionally, a 35-year multi-sensor time series of the qualitative Absorbing Aerosol Index (AAI) together with sensitivity information and an AAI model simulator is available. Complementary aerosol properties requested by GCOS are in a "round robin" phase, where various algorithms are inter-compared: fine mode AOD, mineral dust AOD (from the thermal IASI spectrometer, but also from ATSR instruments and the POLDER sensor), absorption information and aerosol layer height. As a quasi-reference for validation in few selected regions with sparse ground-based observations the multi-pixel GRASP algorithm for the POLDER instrument is used. Validation of first dataset versions (vs. AERONET, MAN) and inter-comparison to other satellite datasets (MODIS, MISR, SeaWIFS) proved the high quality of the available datasets comparable to other satellite retrievals and revealed needs for algorithm improvement (for example for higher AOD values) which were taken into account for a reprocessing. The datasets contain pixel level uncertainty estimates which were also validated and improved in the reprocessing. For the three ATSR algorithms the use of an ensemble method was tested. The paper will summarize and discuss the status of dataset reprocessing and validation. The focus will be on the ATSR, GOMOS and IASI datasets. Pixel level uncertainties validation will be summarized and discussed including unknown components and their potential usefulness and limitations. Opportunities for time series extension

  17. Processing of Unsaturated Organic Acid Aerosols by Ozone

    Science.gov (United States)

    Aloisio, S.; Donaldson, D. J.; Eliason, T. L.; Cziczo, D.; Vaida, V.

    2002-05-01

    We present results of in-situ studies of the oxidative "processing" of organic aerosols composed of unsaturated organic compounds. Aerosol samples of 2-octenoic acid and undecylenic acid were exposed to approx. 10 mbar ozone in a room temperature, atmospheric pressure flow tube reactor. In-situ spectroscopic probing of the reaction mixture, as well as GC-MS analysis of the flow tube effluent, shows evidence of efficient oxidation of double bonds in the organic species, with production of gas-phase and aerosol phase ozonolysis products.

  18. The limits of testing particle-mediated oxidative stress in vitro in predicting diverse pathologies; relevance for testing of nanoparticles

    Directory of Open Access Journals (Sweden)

    Gulumian Mary

    2009-04-01

    Full Text Available Abstract In vitro studies with particles are a major staple of particle toxicology, generally used to investigate mechanisms and better understand the molecular events underlying cellular effects. However, there is ethical and financial pressure in nanotoxicology, the new sub-specialty of particle toxicology, to avoid using animals. Therefore an increasing amount of studies are being published using in vitro approaches and such studies require careful interpretation. We point out here that 3 different conventional pathogenic particle types, PM10, asbestos and quartz, which cause diverse pathological effects, have been reported to cause very similar oxidative stress effects in cells in culture. We discuss the likely explanation and implications of this apparent paradox, and its relevance for testing in nanotoxicology.

  19. Aerosol characterization over the southeastern United States using high resolution aerosol mass spectrometry: spatial and seasonal variation of aerosol composition, sources, and organic nitrates

    Science.gov (United States)

    Xu, L.; Suresh, S.; Guo, H.; Weber, R. J.; Ng, N. L.

    2015-04-01

    We deployed a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and an Aerosol Chemical Speciation Monitor (ACSM) to characterize the chemical composition of submicron non-refractory particles (NR-PM1) in the southeastern US. Measurements were performed in both rural and urban sites in the greater Atlanta area, GA and Centreville, AL for approximately one year, as part of Southeastern Center of Air Pollution and Epidemiology study (SCAPE) and Southern Oxidant and Aerosol Study (SOAS). Organic aerosol (OA) accounts for more than half of NR1 mass concentration regardless of sampling sites and seasons. Positive matrix factorization (PMF) analysis of HR-ToF-AMS measurements identified various OA sources, depending on location and season. Hydrocarbon-like OA (HOA) and cooking OA (COA) have important but not dominant contributions to total OA in urban sites. Biomass burning OA (BBOA) concentration shows a distinct seasonal variation with a larger enhancement in winter than summer. We find a good correlation between BBOA and brown carbon, indicating biomass burning is an important source for brown carbon, although an additional, unidentified brown carbon source is likely present at the rural Yorkville site. Isoprene-derived OA (Isoprene-OA) is only deconvolved in warmer months and contributes 18-36% of total OA. The presence of Isoprene-OA factor in urban sites is more likely from local production in the presence of NOx than transport from rural sites. More-oxidized and less-oxidized oxygenated organic aerosol (MO-OOA and LO-OOA, respectively) are dominant fractions (47-79%) of OA in all sites. MO-OOA correlates well with ozone in summer, but not in winter, indicating MO-OOA sources may vary with seasons. LO-OOA, which reaches a daily maximum at night, correlates better with estimated nitrate functionality from organic nitrates than total nitrates. Based on the HR-ToF-AMS measurements, we estimate that the nitrate functionality from organic nitrates

  20. Test Operations Procedure (TOP) 10-2-022A Chemical Vapor and Aerosol System-Level Testing of Chemical/Biological Protective Suits

    Science.gov (United States)

    2013-12-16

    data, QA/quality control (QC) plans]. 3.1.2 Familiarization. a. Potential problem areas will be identified by reviewing previous records and results...also wear specified footwear , gloves, protective mask, and hood. e. Test operators will assist the TPs in obtaining correct closure of the suit at...Vernon Hills, Illinois); and Pureline II® (Dixon Industries , Charlotte, North Carolina). (4) The pressure inside each RTM while drawing air must not

  1. High-temperature steam oxidation testing of select advanced replacement alloys for potential core internals

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Lizhen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pint, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-05-19

    Coupons from a total of fourteen commercial and custom fabricated alloys were exposed to 1 bar full steam with ~10 ppb oxygen content at 600 and 650°C. The coupons were weighed at 500-h intervals with a total exposure time of 5,000 h. The fourteen alloys are candidate alloys selected under the ARRM program, which include three ferritic steels (Grade 92, 439, and 14YWT), three austenitic stainless steels (316L, 310, and 800), seven Ni-base superalloys (X750, 725, C22, 690, 625, 625 direct-aging, and 625- plus), and one Zr-alloy (Zr–2.5Nb). Among the alloys, 316L and X750 are served as reference alloys for low- and high-strength alloys, respectively. The candidate Ni-base superalloy 718 was procured too late to be included in the tests. The corrosion rates of the candidate alloys can be approximately interpreted by their Cr, Ni and Fe content. The corrosion rate was significantly reduced with increasing Cr content and when Ni content is above ~15 wt%, but not much further reduced when Fe content is less than ~55 wt%. Simplified thermodynamics analyses of the alloy oxidation provided reasonable indications for the constituents of oxide scales formed on the alloys and explanations for the porosity and exfoliation phenomena because of the nature of specific types of oxides.

  2. Characterisation of a uranium fire aerosol

    International Nuclear Information System (INIS)

    Leuscher, A.H.

    1976-01-01

    Uranium swarf, which can burn spontaneously in air, creates an aerosol which is chemically toxic and radiotoxic. The uptake of uranium oxide in the respiratory system is determined to a large extent by the characteristics of the aerosol. A study has been made of the methods by which aerosols can be characterised. The different measured and defined characteristics of particles are given. The normal and lognormal particle size distributions are discussed. Shape factors interrelating characteristics are explained. Experimental techniques for the characterisation of an aerosol are discussed, as well as the instruments that have been used in this study; namely the Andersen impactor, point-to-plane electrostatic precipitator and the Pollak counter. Uranium swarf was made to burn with a heated filament, and the resulting aerosol was measured. Optical and electron microscopy have been used for the determination of the projected area diameters, and the aerodynamic diameters have been determined with the impactor. The uranium fire aerosol can be represented by a bimodal, or monomodal, lognormal particle size distribution depending on the way in which the swarf burns. The determined activity median aerodynamic diameter of the two peaks were 0,49μm and 6,0μm respectively [af

  3. Summary Report on Solid-oxide Electrolysis Cell Testing and Development

    Energy Technology Data Exchange (ETDEWEB)

    J.E. O' Brien; X. Zhang; R.C. O' Brien; G.L. Hawkes

    2012-01-01

    Idaho National Laboratory (INL) has been researching the application of solid-oxide electrolysis cells (SOECs) for large-scale hydrogen production from steam over a temperature range of 800 to 900 C. From 2003 to 2009, this work was sponsored by the United States Department of Energy Nuclear Hydrogen Initiative, under the Office of Nuclear Energy. Starting in 2010, the high-temperature electrolysis (HTE) research program has been sponsored by the INL Next Generation Nuclear Plant Project. This report provides a summaryof program activities performed in Fiscal Year (FY) 2011 and the first quarter of FY-12, with a focus on small-scale testing and cell development activities. HTE research priorities during this period have included the development and testing of SOEC and stack designs that exhibit high-efficiency initial performance and low, long-term degradation rates. This report includes contributions from INL and five industry partners: Materials and Systems Research, Incorporated (MSRI); Versa Power Systems, Incorporated (VPS); Ceramatec, Incorporated; National Aeronautics and Space Administration - Glenn Research Center (NASA - GRC); and the St. Gobain Advanced Materials Division. These industry partners have developed SOEC cells and stacks for in-house testing in the electrolysis mode and independent testing at INL. Additional fundamental research and post-test physical examinations have been performed at two university partners: Massachusetts Institute of Technology (MIT) and the University of Connecticut. Summaries of these activities and test results are also presented in this report.

  4. Results of recent reactor-material tests on dispersal of oxide fuel from a disrupted core

    International Nuclear Information System (INIS)

    Spencer, B.W.; Wilson, R.J.; Vetter, D.L.; Erickson, E.G.; Dewey, G.

    1985-01-01

    The results of experimental investigations and related analyses are reported addressing the dispersal of molten oxide fuel from a disrupted core via various available pathways for the CRBR system. These investigations included the GAPFLOW tests in which pressure-driven and gravity drainage tests were performed using dispersal pathways mocking up the intersubassembly gaps, the CAMEL C6 and C7 tests in which molten fuel entered sodium-filled control assembly ducts under prototypic thermal-hydraulic conditions, and the Lower Internals Drainage (LID) tests in which molten fuel drained downward through simulated below-core structure (orifice plate stacks) as the bottom of control assembly ducts. The results of SHOTGUN tests addressing basic freezing of molten UO 2 and UO 2 /metal mixtures flowing through circular tubes are also reported. Test results have invariably shown the existance of stable UO 2 crusts on the inside surfaces of the flow paths. Appreciable removal of fuel was indicated prior to freezing-induced immobilization. Application of heat transfer models based upon the presence of stable, insulating fuel crusts tends to overpredict the removal process

  5. Aerosol retrieval experiments in the ESA Aerosol_cci project

    Directory of Open Access Journals (Sweden)

    T. Holzer-Popp

    2013-08-01

    Full Text Available Within the ESA Climate Change Initiative (CCI project Aerosol_cci (2010–2013, algorithms for the production of long-term total column aerosol optical depth (AOD datasets from European Earth Observation sensors are developed. Starting with eight existing pre-cursor algorithms three analysis steps are conducted to improve and qualify the algorithms: (1 a series of experiments applied to one month of global data to understand several major sensitivities to assumptions needed due to the ill-posed nature of the underlying inversion problem, (2 a round robin exercise of "best" versions of each of these algorithms (defined using the step 1 outcome applied to four months of global data to identify mature algorithms, and (3 a comprehensive validation exercise applied to one complete year of global data produced by the algorithms selected as mature based on the round robin exercise. The algorithms tested included four using AATSR, three using MERIS and one using PARASOL. This paper summarizes the first step. Three experiments were conducted to assess the potential impact of major assumptions in the various aerosol retrieval algorithms. In the first experiment a common set of four aerosol components was used to provide all algorithms with the same assumptions. The second experiment introduced an aerosol property climatology, derived from a combination of model and sun photometer observations, as a priori information in the retrievals on the occurrence of the common aerosol components. The third experiment assessed the impact of using a common nadir cloud mask for AATSR and MERIS algorithms in order to characterize the sensitivity to remaining cloud contamination in the retrievals against the baseline dataset versions. The impact of the algorithm changes was assessed for one month (September 2008 of data: qualitatively by inspection of monthly mean AOD maps and quantitatively by comparing daily gridded satellite data against daily averaged AERONET sun

  6. Filtration of sodium-fire aerosols

    International Nuclear Information System (INIS)

    Alexas, A.; Jordan, S.; Lindner, W.

    1979-01-01

    Different filter devices have been developed and tested with respect to their use in the off-gas system of liquid-metal fast breeder reactors to prevent the escape of sodium-fire aerosols that might be formed in case of an accident. The testing results have shown that the use of a multilayer sand bed filter is still the best method to filter limited amounts of sodium-fire aerosols over a long operating time. Efficiencies on the order of 99.98 and 98.8% were reached for loading capacities of 500 and 1000 g/m 2 , respectively. Unlimited amounts of sodium-fire aerosols can be filtered by wet scrubbers with an efficiency of 70% per scrubber stage. Fiberglas filters connot be used for the filtration of sodium-fire aerosols over a long operating time because the filter material can be destroyed after several days of operating

  7. Physico-Chemical Evolution of Organic Aerosol from Wildfire Emissions

    Science.gov (United States)

    Croteau, P.; Jathar, S.; Akherati, A.; Galang, A.; Tarun, S.; Onasch, T. B.; Lewane, L.; Herndon, S. C.; Roscioli, J. R.; Yacovitch, T. I.; Fortner, E.; Xu, W.; Daube, C.; Knighton, W. B.; Werden, B.; Wood, E.

    2017-12-01

    Wildfires are the largest combustion-related source of carbonaceous emissions to the atmosphere; these include direct emissions of black carbon (BC), primary organic aerosol (POA) and semi-volatile, intermediate-volatility, and volatile organic compounds (SVOCs, IVOCs, and VOCs). However, there are large uncertainties surrounding the evolution of these carbonaceous emissions as they are physically and chemically transformed in the atmosphere. To understand these transformations, we performed sixteen experiments using an environmental chamber to simulate day- and night-time chemistry of gas- and aerosol-phase emissions from 6 different fuels at the Fire Laboratory in Missoula, MT. Across the test matrix, the experiments simulated 2 to 8 hours of equivalent day-time aging (with the hydroxyl radical and ozone) or several hours of night-time aging (with the nitrate radical). Aging resulted in an average organic aerosol (OA) mass enhancement of 28% although the full range of OA mass enhancements varied between -10% and 254%. These enhancement findings were consistent with chamber and flow reactor experiments performed at the Fire Laboratory in 2010 and 2012 but, similar to previous studies, offered no evidence to link the OA mass enhancement to fuel type or oxidant exposure. Experiments simulating night-time aging resulted in an average OA mass enhancement of 10% and subsequent day-time aging resulted in a decrease in OA mass of 8%. While small, for the first time, these experiments highlighted the continuous nature of the OA evolution as the wildfire smoke cycled through night- and day-time processes. Ongoing work is focussed on (i) quantifying bulk compositional changes in OA, (ii) comparing the near-field aging simulated in this work with far-field aging simulated during the same campaign (via a mini chamber and flow tube) and (iii) integrating wildfire smoke aging datasets over the past decade to examine the relationship between OA mass enhancement ratios, modified

  8. Hot-Fire Test Results of Liquid Oxygen/RP-2 Multi-Element Oxidizer-Rich Preburners

    Science.gov (United States)

    Protz, C. S.; Garcia, C. P.; Casiano, M. J.; Parton, J. A.; Hulka, J. R.

    2016-01-01

    As part of the Combustion Stability Tool Development project funded by the Air Force Space and Missile Systems Center, the NASA Marshall Space Flight Center was contracted to assemble and hot-fire test a multi-element integrated test article demonstrating combustion characteristics of an oxygen/hydrocarbon propellant oxidizer-rich staged-combustion engine thrust chamber. Such a test article simulates flow through the main injectors of oxygen/kerosene oxidizer-rich staged combustion engines such as the Russian RD-180 or NK-33 engines, or future U.S.-built engine systems such as the Aerojet-Rocketdyne AR-1 engine or the Hydrocarbon Boost program demonstration engine. To supply the oxidizer-rich combustion products to the main injector of the integrated test article, existing subscale preburner injectors from a previous NASA-funded oxidizer-rich staged combustion engine development program were utilized. For the integrated test article, existing and newly designed and fabricated inter-connecting hot gas duct hardware were used to supply the oxidizer-rich combustion products to the oxidizer circuit of the main injector of the thrust chamber. However, before one of the preburners was used in the integrated test article, it was first hot-fire tested at length to prove it could provide the hot exhaust gas mean temperature, thermal uniformity and combustion stability necessary to perform in the integrated test article experiment. This paper presents results from hot-fire testing of several preburner injectors in a representative combustion chamber with a sonic throat. Hydraulic, combustion performance, exhaust gas thermal uniformity, and combustion stability data are presented. Results from combustion stability modeling of these test results are described in a companion paper at this JANNAF conference, while hot-fire test results of the preburner injector in the integrated test article are described in another companion paper.

  9. Aerosolization and Atmospheric Transformation of Engineered Nanoparticles

    Science.gov (United States)

    Tiwari, Andrea J.

    While research on the environmental impacts of engineered nanoparticles (ENPs) is growing, the potential for them to be chemically transformed in the atmosphere has been largely ignored. The overall objective of this work was to assess the atmospheric transformation of carbonaceous nanoparticles (CNPs). The research focuses on C60 fullerene because it is an important member of the carbonaceous nanoparticle (CNP) family and is used in a wide variety of applications. The first specific objective was to review the potential of atmospheric transformations to alter the environmental impacts of CNPs. We described atmospheric processes that were likely to physically or chemically alter aerosolized CNPs and demonstrated their relevance to CNP behavior and toxicity in the aqueous and terrestrial environment. In order to investigate the transformations of CNP aerosols under controlled conditions, we developed an aerosolization technique that produces nano-scale aerosols without using solvents, which can alter the surface chemistry of the aerosols. We demonstrated the technique with carbonaceous (C60) and metal oxide (TiO2, CeO2) nanoparticle powders. All resulting aerosols exhibited unimodal size distributions and mode particle diameters below 100 nm. We used the new aerosolization technique to investigate the reaction between aerosolized C60 and atmospherically realistic levels of ozone (O3) in terms of reaction products, reaction rate, and oxidative stress potential. We identified C60O, C60O2, and C60O3 as products of the C60-O3 reaction. We demonstrated that the oxidative stress potential of C 60 may be enhanced by exposure to O3. We found the pseudo-first order reaction rate to be 9 x 10-6 to 2 x 10 -5 s-1, which is several orders of magnitude lower than the rate for several PAH species under comparable conditions. This research has demonstrated that a thorough understanding of atmospheric chemistry of ENPs is critical for accurate prediction of their environmental

  10. Steam Methane Reformation Testing for Air-Independent Solid Oxide Fuel Cell Systems

    Science.gov (United States)

    Mwara, Kamwana N.

    2015-01-01

    Recently, NASA has been looking into utilizing landers that can be propelled by LOX-CH (sub 4), to be used for long duration missions. Using landers that utilize such propellants, also provides the opportunity to use solid oxide fuel cells as a power option, especially since they are able to process methane into a reactant through fuel reformation. One type of reformation, called steam methane reformation, is a process to reform methane into a hydrogen-rich product by reacting methane and steam (fuel cell exhaust) over a catalyst. A steam methane reformation system could potentially use the fuel cell's own exhaust to create a reactant stream that is hydrogen-rich, and requires less internal reforming of the incoming methane. Also, steam reformation may hold some advantages over other types of reforming, such as partial oxidation (PROX) reformation. Steam reformation does not require oxygen, while up to 25 percent can be lost in PROX reformation due to unusable CO (sub 2) reformation. NASA's Johnson Space Center has conducted various phases of steam methane reformation testing, as a viable solution for in-space reformation. This has included using two different types of catalysts, developing a custom reformer, and optimizing the test system to find the optimal performance parameters and operating conditions.

  11. Secondary organic aerosol in the global aerosol – chemical transport model Oslo CTM2

    Directory of Open Access Journals (Sweden)

    I. S. A. Isaksen

    2007-11-01

    Full Text Available The global chemical transport model Oslo CTM2 has been extended to include the formation, transport and deposition of secondary organic aerosol (SOA. Precursor hydrocarbons which are oxidised to form condensible species include both biogenic species such as terpenes and isoprene, as well as species emitted predominantly by anthropogenic activities (toluene, m-xylene, methylbenzene and other aromatics. A model simulation for 2004 gives an annual global SOA production of approximately 55 Tg. Of this total, 2.5 Tg is found to consist of the oxidation products of anthropogenically emitted hydrocarbons, and about 15 Tg is formed by the oxidation products of isoprene. The global production of SOA is increased to about 69 Tg yr−1 by allowing semi-volatile species to partition to ammonium sulphate aerosol. This brings modelled organic aerosol values closer to those observed, however observations in Europe remain significantly underestimated. Allowing SOA to partition into ammonium sulphate aerosol increases the contribution of anthropogenic SOA from about 4.5% to 9.4% of the total production. Total modelled organic aerosol (OA values are found to represent a lower fraction of the measured values in winter (when primary organic aerosol (POA is the dominant OA component than in summer, which may be an indication that estimates of POA emissions are too low. Additionally, for measurement stations where the summer OA values are higher than in winter, the model generally underestimates the increase in summertime OA. In order to correctly model the observed increase in OA in summer, additional SOA sources or formation mechanisms may be necessary. The importance of NO3 as an oxidant of SOA precursors is found to vary regionally, causing up to 50%–60% of the total amount of SOA near the surface in polluted regions and less than 25% in more remote areas, if the yield of condensible oxidation products for β-pinene is used for NO3 oxidation of all terpenes

  12. Understanding the Impact of Model Surfactants on Cloud Condensation Nuclei Activity of Sea Spray Aerosols

    Science.gov (United States)

    Forestieri, S.; Cappa, C. D.; Ruehl, C. R.; Bertram, T. H.; Staudt, S.; Kuborn, T.

    2017-12-01

    Aerosol impacts on cloud properties, also known as indirect effects, remain a major source of uncertainty in modeling global radiative forcing. Reducing this uncertainty necessitates better understanding of how aerosol chemical composition impacts the cloud-forming ability of aerosols. The presence of surfactants in aerosols can decrease the surface tension of activating droplets relative to water and lead to more efficient activation. The importance of this effect has been debated, but recent surface tension measurements of microscopic droplets indicate that surface tension is substantially depressed relative to water for lab-generated particles consisting of salt and a single organic species and for complex mixtures of organic matter. However, little work has been done on understanding how chemical complexity (i.e. interaction between different surfactant species) impacts surface tension for particles containing mixtures of surfactants. In this work, we quantified the surface tension of lab-generated aerosols containing surfactants that are commonly found in nascent sea spray aerosol (SSA) at humidities close to activation using a continuous flow stream-wise thermal gradient chamber (CFSTGC). Surface tension was quantified for particles containing single surfactant species and mixtures of these surfactants to investigate the role of chemical complexity on surface tension and molecular packing at the air-water interface. For all surfactants tested in this study, substantial surface tension depression (20-40 mN/m) relative to water was observed for particles containing large fractions of organic matter at humidities just below activation. However, the presence of these surfactants only weakly depressed surface tension at activation. Kinetic limitations were observed for particles coated with just palmitic acid, since palmitic acid molecules inhibit water uptake through their ability to pack tightly at the surface. However, these kinetic limitations disappeared when

  13. Chemical composition and characteristics of ambient aerosols and rainwater residues during Indian summer monsoon: Insight from aerosol mass spectrometry

    Science.gov (United States)

    Chakraborty, Abhishek; Gupta, Tarun; Tripathi, Sachchida N.

    2016-07-01

    Real time composition of non-refractory submicron aerosol (NR-PM1) is measured via Aerosol mass spectrometer (AMS) for the first time during Indian summer monsoon at Kanpur, a polluted urban location located at the heart of Indo Gangetic Plain (IGP). Submicron aerosols are found to be dominated by organics followed by nitrate. Source apportionment of organic aerosols (OA) via positive matrix factorization (PMF) revealed several types of secondary/oxidized and primary organic aerosols. On average, OA are completely dominated by oxidized OA with a very little contribution from biomass burning OA. During rain events, PM1 concentration is decreased almost by 60%, but its composition remains nearly the same. Oxidized OA showed slightly more decrease than primary OAs, probably due to their higher hygroscopicity. The presence of organo nitrates (ON) is also detected in ambient aerosols. Apart from real-time sampling, collected fog and rainwater samples were also analyzed via AMS in offline mode and in the ICP-OES (Inductively coupled plasma - Optical emission spectrometry) for elements. The presence of sea salt, organo nitrates and sulfates has been observed. Rainwater residues are also dominated by organics but their O/C ratios are 15-20% lower than the observed values for ambient OA. Alkali metals such as Ca, Na, K are found to be most abundant in the rainwater followed by Zn. Rainwater residues are also found to be much less oxidized than the aerosols present inside the fog water, indicating presence of less oxidized organics. These findings indicate that rain can act as an effective scavenger of different types of pollutants even for submicron particle range. Rainwater residues also contain organo sulfates which indicate that some portion of the dissolved aerosols has undergone aqueous processing, possibly inside the cloud. Highly oxidized and possibly hygroscopic OA during monsoon period compared to other seasons (winter, post monsoon), indicates that they can act

  14. Whole-body nanoparticle aerosol inhalation exposures.

    Science.gov (United States)

    Yi, Jinghai; Chen, Bean T; Schwegler-Berry, Diane; Frazer, Dave; Castranova, Vince; McBride, Carroll; Knuckles, Travis L; Stapleton, Phoebe A; Minarchick, Valerie C; Nurkiewicz, Timothy R

    2013-05-07

    Inhalation is the most likely exposure route for individuals working with aerosolizable engineered nano-materials (ENM). To properly perform nanoparticle inhalation toxicology studies, the aerosols in a chamber housing the experimental animals must have: 1) a steady concentration maintained at a desired level for the entire exposure period; 2) a homogenous composition free of contaminants; and 3) a stable size distribution with a geometric mean diameter generation of aerosols containing nanoparticles is quite challenging because nanoparticles easily agglomerate. This is largely due to very strong inter-particle forces and the formation of large fractal structures in tens or hundreds of microns in size (6), which are difficult to be broken up. Several common aerosol generators, including nebulizers, fluidized beds, Venturi aspirators and the Wright dust feed, were tested; however, none were able to produce nanoparticle aerosols which satisfy all criteria (5). A whole-body nanoparticle aerosol inhalation exposure system was fabricated, validated and utilized for nano-TiO2 inhalation toxicology studies. Critical components: 1) novel nano-TiO2 aerosol generator; 2) 0.5 m(3) whole-body inhalation exposure chamber; and 3) monitor and control system. Nano-TiO2 aerosols generated from bulk dry nano-TiO2 powders (primary diameter of 21 nm, bulk density of 3.8 g/cm(3)) were delivered into the exposure chamber at a flow rate of 90 LPM (10.8 air changes/hr). Particle size distribution and mass concentration profiles were measured continuously with a scanning mobility particle sizer (SMPS), and an electric low pressure impactor (ELPI). The aerosol mass concentration (C) was verified gravimetrically (mg/m(3)). The mass (M) of the collected particles was determined as M = (Mpost-Mpre), where Mpre and Mpost are masses of the filter before and after sampling (mg). The mass concentration was calculated as C = M/(Q*t), where Q is sampling flowrate (m(3)/min), and t is the sampling

  15. Antarctic aerosols - A review

    Science.gov (United States)

    Shaw, Glenn E.

    1988-02-01

    Tropospheric aerosols with the diameter range of half a micron reside in the atmosphere for tens of days and teleconnect Antarctica with other regions by transport that reaches planetary scales of distances; thus, the aerosol on the Antarctic ice represents 'memory modules' of events that took place at regions separated from Antarctica by tens of thousands of kilometers. In terms of aerosol mass, the aerosol species include insoluble crustal products (less than 5 percent), transported sea-salt residues (highly variable but averaging about 10 percent), Ni-rich meteoric material, and anomalously enriched material with an unknown origin. Most (70-90 percent by mass) of the aerosol over the Antarctic ice shield, however, is the 'natural acid sulfate aerosol', apparently deriving from biological processes taking place in the surrounding oceans.

  16. The DRAGON aerosol research facility to study aerosol behaviour for reactor safety applications

    International Nuclear Information System (INIS)

    Suckow, Detlef; Guentay, Salih

    2008-01-01

    During a severe accident in a nuclear power plant fission products are expected to be released in form of aerosol particles and droplets. To study the behaviour of safety relevant reactor components under aerosol loads and prototypical severe accident conditions the multi-purpose aerosol generation facility DRAGON is used since 1994 for several projects. DRAGON can generate aerosol particles by the evaporation-condensation technique using a plasma torch system, fluidized bed and atomization of particles suspended in a liquid. Soluble, hygroscopic aerosol (i.e. CsOH) and insoluble aerosol particles (i.e. SnO 2 , TiO 2 ) or mixtures of them can be used. DRAGON uses state-of-the-art thermal-hydraulic, data acquisition and aerosol measurement techniques and is mainly composed of a mixing chamber, the plasma torch system, a steam generator, nitrogen gas and compressed air delivery systems, several aerosol delivery piping, gas heaters and several auxiliary systems to provide vacuum, coolant and off-gas treatment. The facility can be operated at system pressure of 5 bars, temperatures of 300 deg. C, flow rates of non-condensable gas of 900 kg/h and steam of 270 kg/h, respectively. A test section under investigation is attached to DRAGON. The paper summarizes and demonstrates with the help of two project examples the capabilities of DRAGON for reactor safety studies. (authors)

  17. Acute Oxidative Effect and Muscle Damage after a Maximum 4 Min Test in High Performance Athletes.

    Directory of Open Access Journals (Sweden)

    Heros Ribeiro Ferreira

    Full Text Available The purpose of this investigation was to determine lipid peroxidation markers, physiological stress and muscle damage in elite kayakers in response to a maximum 4-min kayak ergometer test (KE test, and possible correlations with individual 1000m kayaking performances. The sample consisted of twenty-three adult male and nine adult female elite kayakers, with more than three years' experience in international events, who voluntarily took part in this study. The subjects performed a 10-min warm-up, followed by a 2-min passive interval, before starting the test itself, which consisted of a maximum 4-min work paddling on an ergometer; right after the end of the test, an 8 ml blood sample was collected for analysis. 72 hours after the test, all athletes took part in an official race, when then it was possible to check their performance in the on site K1 1000m test (P1000m. The results showed that all lipoproteins and hematological parameters tested presented a significant difference (p≤0.05 after exercise for both genders. In addition, parameters related to muscle damage such as lactate dehydrogenase (LDH and creatine kinase (CK presented significant differences after stress. Uric acid presented an inverse correlation with the performance (r = -0.76, while CK presented a positive correlation (r = 0.46 with it. Based on these results, it was possible to verify muscle damage and the level of oxidative stress caused by indoor training with specific ergometers for speed kayaking, highlighting the importance of analyzing and getting to know the physiological responses to this type of training, in order to provide information to coaches and optimize athletic performance.

  18. Water Flow Testing and Unsteady Pressure Analysis of a Two-Bladed Liquid Oxidizer Pump Inducer

    Science.gov (United States)

    Schwarz, Jordan B.; Mulder, Andrew; Zoladz, Thomas

    2011-01-01

    The unsteady fluid dynamic performance of a cavitating two-bladed oxidizer turbopump inducer was characterized through sub-scale water flow testing. While testing a novel inlet duct design that included a cavitation suppression groove, unusual high-frequency pressure oscillations were observed. With potential implications for inducer blade loads, these high-frequency components were analyzed extensively in order to understand their origins and impacts to blade loading. Water flow testing provides a technique to determine pump performance without the costs and hazards associated with handling cryogenic propellants. Water has a similar density and Reynolds number to liquid oxygen. In a 70%-scale water flow test, the inducer-only pump performance was evaluated. Over a range of flow rates, the pump inlet pressure was gradually reduced, causing the flow to cavitate near the pump inducer. A nominal, smooth inducer inlet was tested, followed by an inlet duct with a circumferential groove designed to suppress cavitation. A subsequent 52%-scale water flow test in another facility evaluated the combined inducer-impeller pump performance. With the nominal inlet design, the inducer showed traditional cavitation and surge characteristics. Significant bearing loads were created by large side loads on the inducer during synchronous cavitation. The grooved inlet successfully mitigated these loads by greatly reducing synchronous cavitation, however high-frequency pressure oscillations were observed over a range of frequencies. Analytical signal processing techniques showed these oscillations to be created by a rotating, multi-celled train of pressure pulses, and subsequent CFD analysis suggested that such pulses could be created by the interaction of rotating inducer blades with fluid trapped in a cavitation suppression groove. Despite their relatively low amplitude, these high-frequency pressure oscillations posed a design concern due to their sensitivity to flow conditions and

  19. Cadmium-induced oxidative stress and apoptosis in the testes of frog Rana limnocharis

    International Nuclear Information System (INIS)

    Zhang Hangjun; Cai Chenchen; Shi Cailei; Cao Hui; Han Ziliu; Jia Xiuying

    2012-01-01

    Highlights: ► Cd can cause vacuoles and deformity of the spermatogenic cells in the frog testes. ► Cd can result in oxidative stress in the frog testes. ► Cd can induce significantly increase of ROS contents triggered DNA damages in the frog testes. ► Cd can cause apoptosis in the testes of male R. limnocharis. ► Apoptosis by Cd in the frog testes is related to Caspase-3, Bax and Bcl-2 genes. - Abstract: This study explored the genetic damage induced by cadmium exposure in the testes of Rana limnocharis. Healthy adult frogs were exposed to 2.5, 5, 7.5, or 10 mg/L of cadmium solution for 14 days. The results showed that exposure to these concentrations increased the levels of reactive oxygen species and malondialdehyde content in the testes, clearly indicating a dose–effect relationship. Moreover, the same dosages of Cd 2+ solution increased glutathione (reduced) content, with the values being significantly different from those observed in the control group (P < 0.01). The comet assay results demonstrated that the DNA damage rate, tail length, and tail moment of samples obtained from frogs exposed to 2.5–7.5 mg/L of cadmium solution significantly increased compared with those of samples obtained from the control group (P < 0.01). These findings suggest that cadmium can induce free radical generation, followed by lipid peroxidation and DNA damage. Ultrastructural observation revealed vacuoles in the spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli. Moreover, cadmium exposure induced significant down-regulation of Bcl-2 expression and up-regulation of Bax and caspase-3 expressions. Taken together, these data indicate that cadmium can induce testicular cell apoptosis in R. limnocharis. Exploring the effects of cadmium on the mechanism of reproductive toxicity in amphibians will help provide a scientific basis accounting for the global population decline in amphibian species.

  20. Sulfate-nitrate-ammonium aerosols over China: response to 2000–2015 emission changes of sulfur dioxide, nitrogen oxides, and ammonia

    Directory of Open Access Journals (Sweden)

    Y. Wang

    2013-03-01

    Full Text Available We use a chemical transport model to examine the change of sulfate-nitrate-ammonium (SNA aerosols over China due to anthropogenic emission changes of their precursors (SO2, NOx and NH3 from 2000 to 2015. From 2000 to 2006, annual mean SNA concentrations increased by about 60% over China as a result of the 60% and 80% increases in SO2 and NOx emissions. During this period, sulfate is the dominant component of SNA over South China (SC and Sichuan Basin (SCB, while nitrate and sulfate contribute equally over North China (NC. Based on emission reduction targets in the 12th (2011–2015 Five-Year Plan (FYP, China's total SO2 and NOx emissions are projected to change by −16% and +16% from 2006 to 2015, respectively. The amount of NH3 emissions in 2015 is uncertain, given the lack of sufficient information on the past and present levels of NH3 emissions in China. With no change in NH3 emissions, SNA mass concentrations in 2015 will decrease over SCB and SC compared to their 2006 levels, but increase over NC where the magnitude of nitrate increase exceeds that of sulfate reduction. This suggests that the SO2 emission reduction target set by the 12th FYP, although effective in reducing SNA over SC and SCB, will not be successful over NC, for which NOx emission control needs to be strengthened. If NH3 emissions are allowed to keep their recent growth rate and increase by +16% from 2006 to 2015, the benefit of SO2 reduction will be completely offset over all of China due to the significant increase of nitrate, demonstrating the critical role of NH3 in regulating nitrate. The effective strategy to control SNA and hence PM2.5 pollution over China should thus be based on improving understanding of current NH3 emissions and putting more emphasis on controlling NH3 emissions in the future.

  1. Radioactive aerosols. [In Russian

    Energy Technology Data Exchange (ETDEWEB)

    Natanson, G L

    1956-01-01

    Tabulations are given presenting various published data on safe atmospheric concentrations of various radioactive and non-radioactive aerosols. Methods of determination of active aerosol concentrations and dispersion as well as the technical applications of labeled aerosols are discussed. The effect of atomic explosions are analyzed considering the nominal atomic bomb based on /sup 235/U and /sup 232/Pu equivalent to 20,000 tons of TNT.

  2. Aerosols CFA 97

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    During the thirteen congress on aerosols several papers were presented about the behaviour of radioactive aerosols and their impact on environment, or the exposure to radon and to its daughters, the measurement of the size of the particulates of the short-lived radon daughters and two papers about the behaviour of aerosols in containment during a fission products release in the primary circuit and susceptible to be released in atmosphere in the case of containment failure. (N.C.)

  3. Atmospheric reactivity of hydroxyl radicals with guaiacol (2-methoxyphenol), a biomass burning emitted compound: Secondary organic aerosol formation and gas-phase oxidation products

    Science.gov (United States)

    Lauraguais, Amélie; Coeur-Tourneur, Cécile; Cassez, Andy; Deboudt, Karine; Fourmentin, Marc; Choël, Marie

    2014-04-01

    Methoxyphenols are low molecular weight semi-volatile polar aromatic compounds produced from the pyrolysis of wood lignin. The reaction of guaiacol (2-methoxyphenol) with hydroxyl radicals has been studied in the LPCA simulation chamber at (294 ± 2) K, atmospheric pressure, low relative humidity (RH reactivity of nitroguaiacols with atmospheric oxidants is probably low, we suggest using them as biomass burning emission gas tracers. The atmospheric implications of the guaiacol + OH reaction are also discussed.

  4. Aerosols from biomass combustion

    Energy Technology Data Exchange (ETDEWEB)

    Nussbaumer, T

    2001-07-01

    This report is the proceedings of a seminar on biomass combustion and aerosol production organised jointly by the International Energy Agency's (IEA) Task 32 on bio energy and the Swiss Federal Office of Energy (SFOE). This collection of 16 papers discusses the production of aerosols and fine particles by the burning of biomass and their effects. Expert knowledge on the environmental impact of aerosols, formation mechanisms, measurement technologies, methods of analysis and measures to be taken to reduce such emissions is presented. The seminar, visited by 50 participants from 11 countries, shows, according to the authors, that the reduction of aerosol emissions resulting from biomass combustion will remain a challenge for the future.

  5. Evaluating the graphene oxide dispersions for Fish Embryo Toxicity (FET) test

    Energy Technology Data Exchange (ETDEWEB)

    Clemente, Zaira; Franqui, Lidiane; Silva, Cristiane A.; Martinez, Diego Stefani Teodoro, E-mail: zairaclemente@hotmail.com [Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, SP (Brazil); Castro, Vera Lucia Scherholz Salgado [Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA), Campinhas, SP (Brazil)

    2016-07-01

    Full text: The Fish Embryo Toxicity (FET) test has wide utilization in nano ecotoxicology. However, some difficulties have been found related to the aggregation and precipitation of nanomaterials in exposure medium and the contrasting results among studies due to differences in the material characteristics. Furthermore, abiotic factors as the presence of organic matter can influence the test evaluation. The aim of this study was to evaluate and characterize the effect of the humic acid presence in the stability of two types of graphene oxide dispersion in an exposure medium used in FET test. Stock-suspensions (1.0 mg mL{sup -1}) of GO (sigma Aldrich, flakes) or base-washed GO (bwGO) and humic acid (HA sodium salt, Sigma Aldrich) were prepared in ultrapure water (UW). They were sonicated before preparing the GO or bwGO test suspensions at 100.0 μg mL{sup -1} in UW and reconstituted water (RW, pH 8±0.2, 425±129 μS/cm), with HA (20.0 μg mL{sup -1})or not. The samples were incubated during 96h at 26 deg C. The GO and bwGO and its dispersions were characterized through the following techniques: spectrophotometry, centrifugation, dynamic light scattering (DLS), nanoparticle tracking analysis (NTA), thermogravimetry (TGA), and X-ray photoelectron spectrometry (XPS). The results showed that materials aggregated and precipitated quickly in RW, but in the presence of HA the stability was similar to that found in UW. The aggregation and precipitation of bwGO was more intense than that of GO. The bwGO showed a great particle sizes heterogeneity than GO, in any condition tested. The different behavior can be related to the less presence of oxygenated groups in bwGO regards to GO. These results showed that surface characteristic of GO and the presence of HA influence the GO behavior in exposure medium and support the use of HA as a natural dispersant to graphene oxide in FET test. (author)

  6. Devices and methods for generating an aerosol

    KAUST Repository

    Bisetti, Fabrizio; Scribano, Gianfranco

    2016-01-01

    Aerosol generators and methods of generating aerosols are provided. The aerosol can be generated at a stagnation interface between a hot, wet stream and a cold, dry stream. The aerosol has the be