Sample records for comprehensive primary particulate

  1. Time-resolved characterization of primary particle emissions and secondary particle formation from a modern gasoline passenger car

    NASA Astrophysics Data System (ADS)

    Karjalainen, Panu; Timonen, Hilkka; Saukko, Erkka; Kuuluvainen, Heino; Saarikoski, Sanna; Aakko-Saksa, Päivi; Murtonen, Timo; Bloss, Matthew; Dal Maso, Miikka; Simonen, Pauli; Ahlberg, Erik; Svenningsson, Birgitta; Brune, William Henry; Hillamo, Risto; Keskinen, Jorma; Rönkkö, Topi

    2016-07-01

    Changes in vehicle emission reduction technologies significantly affect traffic-related emissions in urban areas. In many densely populated areas the amount of traffic is increasing, keeping the emission level high or even increasing. To understand the health effects of traffic-related emissions, both primary (direct) particulate emission and secondary particle formation (from gaseous precursors in the exhaust emissions) need to be characterized. In this study, we used a comprehensive set of measurements to characterize both primary and secondary particulate emissions of a Euro 5 level gasoline passenger car. Our aerosol particle study covers the whole process chain in emission formation, from the tailpipe to the atmosphere, and also takes into account differences in driving patterns. We observed that, in mass terms, the amount of secondary particles was 13 times higher than the amount of primary particles. The formation, composition, number and mass of secondary particles was significantly affected by driving patterns and engine conditions. The highest gaseous and particulate emissions were observed at the beginning of the test cycle when the performance of the engine and the catalyst was below optimal. The key parameter for secondary particle formation was the amount of gaseous hydrocarbons in primary emissions; however, also the primary particle population had an influence.

  2. MULTI-SITE PERFORMANCE EVALUATIONS OF CANDIDATE METHODOLOGIES FOR DETERMINING COARSE PARTICULATE MATTER (PMC) CONCENTRATIONS

    EPA Science Inventory

    Comprehensive field studies were conducted to evaluate the performance of sampling methods for measuring the coarse fraction of PM10 in ambient air. Five separate sampling approaches were evaluated at each of three sampling sites. As the primary basis of comparison, a discret...

  3. MULTI-SITE EVALUATIONS OF CANDIDATE METHODOLOGIES FOR DETERMINING COARSE PARTICULATE MATTER (PMC) CONCENTRATIONS

    EPA Science Inventory

    Comprehensive field studies were conducted to evaluate the performance of sampling methods for measuring the coarse fraction of PM10 in ambient air. Five separate sampling approaches were evaluated at each of three sampling sites. As the primary basis of comparison, a discret...

  4. MULTI-SITE EVALUATIONS OF CANDIDATE METHODOLOGIES FOR DETERMINING COARSE PARTICULATE MATTER (PMC) CONCENTRATIONS

    EPA Science Inventory

    Comprehensive field studies were conducted to evaluate the performance of sampling methods for measuring the coarse fraction of PM10 in ambient air. Five separate sampling approaches were evaluated at each of three sampling sites. As the primary basis of comparison, a discrete ...

  5. A Comprehensive Modeling Approach Towards Understanding and Prediction of the Alaskan Coastal System Response to Changes in an Ice-diminished Arctic

    DTIC Science & Technology

    2008-01-01

    signature of an apparent increased contribution of diazotrophs to Arctic primary production was also recorded in muscle tissue of bowheads, harvested from...Arctic temperatures of the Beaufort Sea need not be invoked. Instead, the diazotrophic marker of particulate nitrogen within bowhead whale baleen...dinoflagellates, microflagellates, and diazotrophs from downstream boreal and subtropical ecosystems. Furthermore, at lower latitudes, Saharan dust plumes in

  6. 40 CFR 52.2059 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 5 2012-07-01 2012-07-01 false Control strategy: Particulate matter... Control strategy: Particulate matter. (a) Pennsylvania has committed to undertake a comprehensive program... Investigating and Controlling Nontraditional Particulate Matter Emissions Task Completion date Scheduled tasks...

  7. 40 CFR 52.2059 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Control strategy: Particulate matter... Control strategy: Particulate matter. (a) Pennsylvania has committed to undertake a comprehensive program... Investigating and Controlling Nontraditional Particulate Matter Emissions Task Completion date Scheduled tasks...

  8. 40 CFR 52.2059 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Particulate matter... Control strategy: Particulate matter. (a) Pennsylvania has committed to undertake a comprehensive program... Investigating and Controlling Nontraditional Particulate Matter Emissions Task Completion date Scheduled tasks...

  9. 40 CFR 52.2059 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Control strategy: Particulate matter... Control strategy: Particulate matter. (a) Pennsylvania has committed to undertake a comprehensive program... Investigating and Controlling Nontraditional Particulate Matter Emissions Task Completion date Scheduled tasks...

  10. Influence of fuel ethanol content on primary emissions and secondary aerosol formation potential for a modern flex-fuel gasoline vehicle

    NASA Astrophysics Data System (ADS)

    Timonen, Hilkka; Karjalainen, Panu; Saukko, Erkka; Saarikoski, Sanna; Aakko-Saksa, Päivi; Simonen, Pauli; Murtonen, Timo; Dal Maso, Miikka; Kuuluvainen, Heino; Bloss, Matthew; Ahlberg, Erik; Svenningsson, Birgitta; Pagels, Joakim; Brune, William H.; Keskinen, Jorma; Worsnop, Douglas R.; Hillamo, Risto; Rönkkö, Topi

    2017-04-01

    The effect of fuel ethanol content (10, 85 and 100 %) on primary emissions and on subsequent secondary aerosol formation was investigated for a Euro 5 flex-fuel gasoline vehicle. Emissions were characterized during a New European Driving Cycle (NEDC) using a comprehensive set-up of high time-resolution instruments. A detailed chemical composition of the exhaust particulate matter (PM) was studied using a soot particle aerosol mass spectrometer (SP-AMS), and secondary aerosol formation was studied using a potential aerosol mass (PAM) chamber. For the primary gaseous compounds, an increase in total hydrocarbon emissions and a decrease in aromatic BTEX (benzene, toluene, ethylbenzene and xylenes) compounds was observed when the amount of ethanol in the fuel increased. In regard to particles, the largest primary particulate matter concentrations and potential for secondary particle formation was measured for the E10 fuel (10 % ethanol). As the ethanol content of the fuel increased, a significant decrease in the average primary particulate matter concentrations over the NEDC was found. The PM emissions were 0.45, 0.25 and 0.15 mg m-3 for E10, E85 and E100, respectively. Similarly, a clear decrease in secondary aerosol formation potential was observed with a larger contribution of ethanol in the fuel. The secondary-to-primary PM ratios were 13.4 and 1.5 for E10 and E85, respectively. For E100, a slight decrease in PM mass was observed after the PAM chamber, indicating that the PM produced by secondary aerosol formation was less than the PM lost through wall losses or the degradation of the primary organic aerosol (POA) in the chamber. For all fuel blends, the formed secondary aerosol consisted mostly of organic compounds. For E10, the contribution of organic compounds containing oxygen increased from 35 %, measured for primary organics, to 62 % after the PAM chamber. For E85, the contribution of organic compounds containing oxygen increased from 42 % (primary) to 57 % (after the PAM chamber), whereas for E100 the amount of oxidized organics remained the same (approximately 62 %) with the PAM chamber when compared to the primary emissions.

  11. 2008 Report for the Project Entitled: A Comprehensive Modeling Approach Towards Understanding and Prediction of the Alaskan Coastal System Response to Changes in an Ice-diminished Arctic

    DTIC Science & Technology

    2008-01-01

    apparent increased contribution of diazotrophs to Arctic primary production was also recorded in muscle tissue of bowheads, harvested from the Beaufort...temperatures of the Beaufort Sea need not be invoked. Instead, the diazotrophic marker of particulate nitrogen within bowhead whale baleen and muscle...microflagellates, and diazotrophs from downstream boreal and subtropical ecosystems. Furthermore, at lower latitudes, Saharan dust plumes in the Gulf of

  12. Time-resolved characterization of primary and secondary particle emissions of a modern gasoline passenger car

    NASA Astrophysics Data System (ADS)

    Karjalainen, P.; Timonen, H.; Saukko, E.; Kuuluvainen, H.; Saarikoski, S.; Aakko-Saksa, P.; Murtonen, T.; Dal Maso, M.; Ahlberg, E.; Svenningsson, B.; Brune, W. H.; Hillamo, R.; Keskinen, J.; Rönkkö, T.

    2015-11-01

    Changes in traffic systems and vehicle emission reduction technologies significantly affect traffic-related emissions in urban areas. In many densely populated areas the amount of traffic is increasing, keeping the emission level high or even increasing. To understand the health effects of traffic related emissions, both primary and secondary particles that are formed in the atmosphere from gaseous exhaust emissions need to be characterized. In this study we used a comprehensive set of measurements to characterize both primary and secondary particulate emissions of a modern gasoline passenger car. Our aerosol particle study covers the whole process chain in emission formation, from the engine to the atmosphere, and takes into account also differences in driving patterns. We observed that in mass terms, the amount of secondary particles was 13 times higher than the amount of primary particles. The formation, composition, number, and mass of secondary particles was significantly affected by driving patterns and engine conditions. The highest gaseous and particulate emissions were observed at the beginning of the test cycle when the performance of the engine and the catalyst was below optimal. The key parameter for secondary particle formation was the amount of gaseous hydrocarbons in primary emissions; however, also the primary particle population had an influence. Thus, in order to enhance human health and wellbeing in urban areas, our study strongly indicates that in future legislation, special attention should be directed into the reduction of gaseous hydrocarbons.

  13. Monitoring of PM10 and PM2.5 around primary particulate anthropogenic emission sources

    NASA Astrophysics Data System (ADS)

    Querol, Xavier; Alastuey, Andrés; Rodriguez, Sergio; Plana, Felicià; Mantilla, Enrique; Ruiz, Carmen R.

    Investigations on the monitoring of ambient air levels of atmospheric particulates were developed around a large source of primary anthropogenic particulate emissions: the industrial ceramic area in the province of Castelló (Eastern Spain). Although these primary particulate emissions have a coarse grain-size distribution, the atmospheric transport dominated by the breeze circulation accounts for a grain-size segregation, which results in ambient air particles occurring mainly in the 2.5-10 μm range. The chemical composition of the ceramic particulate emissions is very similar to the crustal end-member but the use of high Al, Ti and Fe as tracer elements as well as a peculiar grain-size distribution in the insoluble major phases allow us to identify the ceramic input in the bulk particulate matter. PM2.5 instead of PM10 monitoring may avoid the interference of crustal particles without a major reduction in the secondary anthropogenic load, with the exception of nitrate. However, a methodology based in PM2.5 measurement alone is not adequate for monitoring the impact of primary particulate emissions (such as ceramic emissions) on air quality, since the major ambient air particles derived from these emissions are mainly in the range of 2.5-10 μm. Consequently, in areas characterised by major secondary particulate emissions, PM2.5 monitoring should detect anthropogenic particulate pollutants without crustal particulate interference, whereas PM10 measurements should be used in areas with major primary anthropogenic particulate emissions.

  14. The 2014 Integrated Field Exercise of the Comprehensive Nuclear-Test-Ban Treaty revisited: The case for data fusion

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Burnett, Jonathan L.; Miley, Harry S.; Bowyer, Theodore W.

    The International Monitoring System of the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) uses a global network of radionuclide monitoring stations to detect evidence of a nuclear explosion. The two radionuclide technologies employed—particulate and noble gas (radioxenon) detection—have applications for data fusion to improve detection of a nuclear explosion. Using the hypothetical 0.5 kT nuclear explosive test scenario of the CTBTO 2014 Integrated Field Exercise, the intrinsic relationship between particulate and noble gas signatures has been examined. This study shows that, depending upon the time of the radioxenon release, the particulate progeny can produce the more detectable signature.more » Thus, as both particulate and noble gas signatures are inherently coupled, the authors recommend that the sample categorization schemes should be linked.« less

  15. The 2014 Integrated Field Exercise of the Comprehensive Nuclear-Test-Ban Treaty revisited: The case for data fusion.

    PubMed

    Burnett, Jonathan L; Miley, Harry S; Bowyer, Theodore W; Cameron, Ian M

    2018-09-01

    The International Monitoring System of the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) uses a global network of radionuclide monitoring stations to detect evidence of a nuclear explosion. The two radionuclide technologies employed-particulate and noble gas (radioxenon) detection-have applications for data fusion to improve detection of a nuclear explosion. Using the hypothetical 0.5 kT nuclear explosive test scenario of the CTBTO 2014 Integrated Field Exercise, the intrinsic relationship between particulate and noble gas signatures has been examined. This study shows that, depending upon the time of the radioxenon release, the particulate progeny can produce the more detectable signature. Thus, as both particulate and noble gas signatures are inherently coupled, the authors recommend that the sample categorization schemes should be linked. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Shuttle filter study. Volume 1: Characterization and optimization of filtration devices

    NASA Technical Reports Server (NTRS)

    1974-01-01

    A program to develop a new technology base for filtration equipment and comprehensive fluid particulate contamination management techniques was conducted. The study has application to the systems used in the space shuttle and space station projects. The scope of the program is as follows: (1) characterization and optimization of filtration devices, (2) characterization of contaminant generation and contaminant sensitivity at the component level, and (3) development of a comprehensive particulate contamination management plane for space shuttle fluid systems.

  17. Fine particulate matter emissions inventories: comparisons of emissions estimates with observations from recent field programs.

    PubMed

    Simon, Heather; Allen, David T; Wittig, Ann E

    2008-02-01

    Emissions inventories of fine particulate matter (PM2.5) were compared with estimates of emissions based on data emerging from U.S. Environment Protection Agency Particulate Matter Supersites and other field programs. Six source categories for PM2.5 emissions were reviewed: on-road mobile sources, nonroad mobile sources, cooking, biomass combustion, fugitive dust, and stationary sources. Ammonia emissions from all of the source categories were also examined. Regional emissions inventories of PM in the exhaust from on-road and nonroad sources were generally consistent with ambient observations, though uncertainties in some emission factors were twice as large as the emission factors. In contrast, emissions inventories of road dust were up to an order of magnitude larger than ambient observations, and estimated brake wear and tire dust emissions were half as large as ambient observations in urban areas. Although comprehensive nationwide emissions inventories of PM2.5 from cooking sources and biomass burning are not yet available, observational data in urban areas suggest that cooking sources account for approximately 5-20% of total primary emissions (excluding dust), and biomass burning sources are highly dependent on region. Finally, relatively few observational data were available to assess the accuracy of emission estimates for stationary sources. Overall, the uncertainties in primary emissions for PM2.s are substantial. Similar uncertainties exist for ammonia emissions. Because of these uncertainties, the design of PM2.5 control strategies should be based on inventories that have been refined by a combination of bottom-up and top-down methods.

  18. Thermal conductivity of particulate materials: A summary of measurements taken at the Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Fountain, J. A.

    1973-01-01

    Thermal conductivity measurements of particulate materials in vacuum are presented in summary. Particulate basalt and soda lime glass beads of various size ranges were used as samples. The differentiated line heat source method was used for the measurements. A comprehensive table is shown giving all pertinent experimental conditions. Least-squares curve fits to the data are presented.

  19. SOURCE APPORTIONMENT OF PRIMARY CARBONACEOUS AEROSOL USING THE COMMUNITY MULTISCALE AIR QUALITY MODEL

    EPA Science Inventory

    A substantial fraction of fine particulate matter (PM) across the United States is composed of carbon, which may be either emitted in particulate form (i.e., primary) or formed in the atmosphere through gas-to-particle conversion processes (i.e., secondary). Primary carbonaceous...

  20. 40 CFR 63.1652 - Emission standards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (including primary and tapping) containing particulate matter in excess of one of the following: (1) 0.23... from any existing open submerged arc furnace exhaust gases (including primary and tapping) containing... primary, tapping, and vent stacks) containing particulate matter in excess of 11.2 kg/hr (24.7 lb/hr) when...

  1. Biparticle fluidized bed reactor

    DOEpatents

    Scott, Charles D.; Marasco, Joseph A.

    1995-01-01

    A fluidized bed reactor system utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves.

  2. Biparticle fluidized bed reactor

    DOEpatents

    Scott, Charles D.; Marasco, Joseph A.

    1996-01-01

    A fluidized bed reactor system which utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary and tertiary particulate phases, continuously introduced and removed simultaneously in the cocurrent and countercurrent mode, act in a role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Means for introducing and removing the sorbent phases include feed screw mechanisms and multivane slurry valves.

  3. Biparticle fluidized bed reactor

    DOEpatents

    Scott, C.D.; Marasco, J.A.

    1995-04-25

    A fluidized bed reactor system utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves. 3 figs.

  4. Biparticle fluidized bed reactor

    DOEpatents

    Scott, C.D.

    1993-12-14

    A fluidized bed reactor system which utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase is described. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves. 3 figures.

  5. Biparticle fluidized bed reactor

    DOEpatents

    Scott, C.D.; Marasco, J.A.

    1996-02-27

    A fluidized bed reactor system is described which utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary and tertiary particulate phases, continuously introduced and removed simultaneously in the cocurrent and countercurrent mode, act in a role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Means for introducing and removing the sorbent phases include feed screw mechanisms and multivane slurry valves. 3 figs.

  6. Biparticle fluidized bed reactor

    DOEpatents

    Scott, Charles D.

    1993-01-01

    A fluidized bed reactor system which utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves.

  7. EXPOSURE ASSESSMENT OF PARTICULATE MATTER FOR SUSCEPTIBLE POPULATIONS IN SEATTLE

    EPA Science Inventory

    In this article we present results from a 2-year comprehensive exposure assessment study that examined the particulate matter (PM) exposures and health effects in 108 individuals with and without chronic obstructive pulmonary disease (COPD), coronary heart disease (CHD), and as...

  8. MULTISCALE AIR QUALITY SIMULATION PLATFORM (MAQSIP): INITIAL APPLICATIONS AND PERFORMANCE FOR TROPOSPHERIC OZONE AND PARTICULATE MATTER

    EPA Science Inventory

    This manuscript provides an overview of the formulation, process considerations, and performance for simulating tropospheric ozone and particulate matter distributions of the Multiscale Air Quality Simulation Platform (MAQSIP). MAQSIP is a comprehensive atmospheric chemistry/tran...

  9. Volatility-resolved source apportionment of primary and secondary organic aerosol over Europe

    NASA Astrophysics Data System (ADS)

    Skyllakou, Ksakousti; Fountoukis, Christos; Charalampidis, Panagiotis; Pandis, Spyros N.

    2017-10-01

    A three-dimensional regional chemical transport model (Particulate Matter Comprehensive Air Quality Model with Extensions, PMCAMx) was applied over Europe combined with a source apportionment algorithm, the Particulate Source Apportionment Technology (PSAT), in order to quantify the sources which contribute to the primary and secondary organic aerosol (OA) during different seasons. The PSAT algorithm was first extended to allow the quantification of the sources of OA as a function of volatility. The most significant OA sources during May were biogenic, while during February residential wood combustion and during September wildfires dominated. The contributions of the various sources have strong spatial dependence. Wildfires were significant OA sources (38% of the OA) for Russia during September, but had a much lower impact (5%) in Scandinavia. The above results are in general consistent with the findings of the CARBOSOL project for selected sites in Europe. For remote sites such as Finokalia in Crete, more than 90% of the OA has undergone two or more generations of oxidation for all seasons. This highly processed oxidized OA is predicted to also dominate over much of Europe during the summer and fall. The first generation SOA is predicted to represent 20-30% of the OA in central and northern Europe during these photochemically active periods.

  10. Control Techniques for Particulate Air Pollutants.

    ERIC Educational Resources Information Center

    National Air Pollution Control Administration (DHEW), Washington, DC.

    Included is a comprehensive review of the approaches commonly recommended for controlling the sources of particulate air pollution. Not all possible combinations of control techniques that might bring about more stringent control of each individual source are reviewed. The many agricultural, commercial, domestic, industrial, and municipal…

  11. Chemometric analysis of multisensor hyperspectral images of precipitated atmospheric particulate matter.

    PubMed

    Ofner, Johannes; Kamilli, Katharina A; Eitenberger, Elisabeth; Friedbacher, Gernot; Lendl, Bernhard; Held, Andreas; Lohninger, Hans

    2015-09-15

    The chemometric analysis of multisensor hyperspectral data allows a comprehensive image-based analysis of precipitated atmospheric particles. Atmospheric particulate matter was precipitated on aluminum foils and analyzed by Raman microspectroscopy and subsequently by electron microscopy and energy dispersive X-ray spectroscopy. All obtained images were of the same spot of an area of 100 × 100 μm(2). The two hyperspectral data sets and the high-resolution scanning electron microscope images were fused into a combined multisensor hyperspectral data set. This multisensor data cube was analyzed using principal component analysis, hierarchical cluster analysis, k-means clustering, and vertex component analysis. The detailed chemometric analysis of the multisensor data allowed an extensive chemical interpretation of the precipitated particles, and their structure and composition led to a comprehensive understanding of atmospheric particulate matter.

  12. Toxicological assessment of particulate emissions from the exhaust of old and new model heavy- and light-duty vehicles.

    DOT National Transportation Integrated Search

    2011-06-01

    The primary objective of this project is to develop an improved understanding of the factors affecting the toxicology of particulate exhaust emissions. Diesel particulate matter is a known carcinogen, and particulate exhaust emissions from both light...

  13. Effects of Source-Apportioned Coarse Particulate Matter (PM) on Allergic Responses in Mice

    EPA Science Inventory

    The Cleveland Multiple Air Pollutant Study (CMAPS) is one of the first comprehensive studies conducted to evaluate particulate matter (PM) over local and regional scales. Cleveland and the nearby Ohio River Valley impart significant regional sources of air pollution including coa...

  14. High secondary aerosol contribution to particulate pollution during haze events in China.

    PubMed

    Huang, Ru-Jin; Zhang, Yanlin; Bozzetti, Carlo; Ho, Kin-Fai; Cao, Jun-Ji; Han, Yongming; Daellenbach, Kaspar R; Slowik, Jay G; Platt, Stephen M; Canonaco, Francesco; Zotter, Peter; Wolf, Robert; Pieber, Simone M; Bruns, Emily A; Crippa, Monica; Ciarelli, Giancarlo; Piazzalunga, Andrea; Schwikowski, Margit; Abbaszade, Gülcin; Schnelle-Kreis, Jürgen; Zimmermann, Ralf; An, Zhisheng; Szidat, Sönke; Baltensperger, Urs; El Haddad, Imad; Prévôt, André S H

    2014-10-09

    Rapid industrialization and urbanization in developing countries has led to an increase in air pollution, along a similar trajectory to that previously experienced by the developed nations. In China, particulate pollution is a serious environmental problem that is influencing air quality, regional and global climates, and human health. In response to the extremely severe and persistent haze pollution experienced by about 800 million people during the first quarter of 2013 (refs 4, 5), the Chinese State Council announced its aim to reduce concentrations of PM2.5 (particulate matter with an aerodynamic diameter less than 2.5 micrometres) by up to 25 per cent relative to 2012 levels by 2017 (ref. 6). Such efforts however require elucidation of the factors governing the abundance and composition of PM2.5, which remain poorly constrained in China. Here we combine a comprehensive set of novel and state-of-the-art offline analytical approaches and statistical techniques to investigate the chemical nature and sources of particulate matter at urban locations in Beijing, Shanghai, Guangzhou and Xi'an during January 2013. We find that the severe haze pollution event was driven to a large extent by secondary aerosol formation, which contributed 30-77 per cent and 44-71 per cent (average for all four cities) of PM2.5 and of organic aerosol, respectively. On average, the contribution of secondary organic aerosol (SOA) and secondary inorganic aerosol (SIA) are found to be of similar importance (SOA/SIA ratios range from 0.6 to 1.4). Our results suggest that, in addition to mitigating primary particulate emissions, reducing the emissions of secondary aerosol precursors from, for example, fossil fuel combustion and biomass burning is likely to be important for controlling China's PM2.5 levels and for reducing the environmental, economic and health impacts resulting from particulate pollution.

  15. High secondary aerosol contribution to particulate pollution during haze events in China

    NASA Astrophysics Data System (ADS)

    Huang, Ru-Jin; Zhang, Yanlin; Bozzetti, Carlo; Ho, Kin-Fai; Cao, Jun-Ji; Han, Yongming; Daellenbach, Kaspar R.; Slowik, Jay G.; Platt, Stephen M.; Canonaco, Francesco; Zotter, Peter; Wolf, Robert; Pieber, Simone M.; Bruns, Emily A.; Crippa, Monica; Ciarelli, Giancarlo; Piazzalunga, Andrea; Schwikowski, Margit; Abbaszade, Gülcin; Schnelle-Kreis, Jürgen; Zimmermann, Ralf; An, Zhisheng; Szidat, Sönke; Baltensperger, Urs; Haddad, Imad El; Prévôt, André S. H.

    2014-10-01

    Rapid industrialization and urbanization in developing countries has led to an increase in air pollution, along a similar trajectory to that previously experienced by the developed nations. In China, particulate pollution is a serious environmental problem that is influencing air quality, regional and global climates, and human health. In response to the extremely severe and persistent haze pollution experienced by about 800 million people during the first quarter of 2013 (refs 4, 5), the Chinese State Council announced its aim to reduce concentrations of PM2.5 (particulate matter with an aerodynamic diameter less than 2.5 micrometres) by up to 25 per cent relative to 2012 levels by 2017 (ref. 6). Such efforts however require elucidation of the factors governing the abundance and composition of PM2.5, which remain poorly constrained in China. Here we combine a comprehensive set of novel and state-of-the-art offline analytical approaches and statistical techniques to investigate the chemical nature and sources of particulate matter at urban locations in Beijing, Shanghai, Guangzhou and Xi'an during January 2013. We find that the severe haze pollution event was driven to a large extent by secondary aerosol formation, which contributed 30-77 per cent and 44-71 per cent (average for all four cities) of PM2.5 and of organic aerosol, respectively. On average, the contribution of secondary organic aerosol (SOA) and secondary inorganic aerosol (SIA) are found to be of similar importance (SOA/SIA ratios range from 0.6 to 1.4). Our results suggest that, in addition to mitigating primary particulate emissions, reducing the emissions of secondary aerosol precursors from, for example, fossil fuel combustion and biomass burning is likely to be important for controlling China's PM2.5 levels and for reducing the environmental, economic and health impacts resulting from particulate pollution.

  16. Diagnostic Air Quality Model Evaluation of Source-Specific Primary and Secondary Fine Particulate Carbon

    EPA Science Inventory

    Ambient measurements of 78 source-specific tracers of primary and secondary carbonaceous fine particulate matter collected at four midwestern United States locations over a full year (March 2004–February 2005) provided an unprecedented opportunity to diagnostically evaluate...

  17. Impact of rail pressure and biodiesel fueling on the particulate morphology and soot nanostructures from a common-rail turbocharged direct injection diesel engine

    DOE PAGES

    Ye, Peng; Vander Wal, Randy; Boehman, Andre L.; ...

    2014-12-26

    The effect of rail pressure and biodiesel fueling on the morphology of exhaust particulate agglomerates and the nanostructure of primary particles (soot) was investigated with a common-rail turbocharged direct injection diesel engine. The engine was operated at steady state on a dynamometer running at moderate speed with both low (30%) and medium–high (60%) fixed loads, and exhaust particulate was sampled for analysis. Ultra-low sulfur diesel and its 20% v/v blends with soybean methyl ester biodiesel were used. Fuel injection occurred in a single event around top dead center at three different injection pressures. Exhaust particulate samples were characterized with TEMmore » imaging, scanning mobility particle sizing, thermogravimetric analysis, Raman spectroscopy, and XRD analysis. Particulate morphology and oxidative reactivity were found to vary significantly with rail pressure and with biodiesel blend level. Higher biodiesel content led to increases in the primary particle size and oxidative reactivity but did not affect nanoscale disorder in the as-received samples. For particulates generated with higher injection pressures, the initial oxidative reactivity increased, but there was no detectable correlation with primary particle size or nanoscale disorder.« less

  18. Impact of rail pressure and biodiesel fueling on the particulate morphology and soot nanostructures from a common-rail turbocharged direct injection diesel engine

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ye, Peng; Vander Wal, Randy; Boehman, Andre L.

    The effect of rail pressure and biodiesel fueling on the morphology of exhaust particulate agglomerates and the nanostructure of primary particles (soot) was investigated with a common-rail turbocharged direct injection diesel engine. The engine was operated at steady state on a dynamometer running at moderate speed with both low (30%) and medium–high (60%) fixed loads, and exhaust particulate was sampled for analysis. Ultra-low sulfur diesel and its 20% v/v blends with soybean methyl ester biodiesel were used. Fuel injection occurred in a single event around top dead center at three different injection pressures. Exhaust particulate samples were characterized with TEMmore » imaging, scanning mobility particle sizing, thermogravimetric analysis, Raman spectroscopy, and XRD analysis. Particulate morphology and oxidative reactivity were found to vary significantly with rail pressure and with biodiesel blend level. Higher biodiesel content led to increases in the primary particle size and oxidative reactivity but did not affect nanoscale disorder in the as-received samples. For particulates generated with higher injection pressures, the initial oxidative reactivity increased, but there was no detectable correlation with primary particle size or nanoscale disorder.« less

  19. Fluidizing a mixture of particulate coal and char

    DOEpatents

    Green, Norman W.

    1979-08-07

    Method of mixing particulate materials comprising contacting a primary source and a secondary source thereof whereby resulting mixture ensues; preferably at least one of the two sources has enough motion to insure good mixing and the particulate materials may be heat treated if desired. Apparatus for such mixing comprising an inlet for a primary source, a reactor communicating therewith, a feeding means for supplying a secondary source to the reactor, and an inlet for the secondary source. Feeding means is preferably adapted to supply fluidized materials.

  20. Secondary organic aerosol production from diesel vehicle exhaust: impact of aftertreatment, fuel chemistry and driving cycle

    NASA Astrophysics Data System (ADS)

    Gordon, T. D.; Presto, A. A.; Nguyen, N. T.; Robertson, W. H.; Na, K.; Sahay, K. N.; Zhang, M.; Maddox, C.; Rieger, P.; Chattopadhyay, S.; Maldonado, H.; Maricq, M. M.; Robinson, A. L.

    2013-09-01

    Environmental chamber ("smog chamber") experiments were conducted to investigate secondary organic aerosol (SOA) production from dilute emissions from two medium-duty diesel vehicles (MDDVs) and three heavy-duty diesel vehicles (HDDVs) under urban-like conditions. Some of the vehicles were equipped with emission control aftertreatment devices including diesel particulate filters (DPF), selective catalytic reduction (SCR) and diesel oxidation catalysts (DOC). Experiments were also performed with different fuels (100% biodiesel and low-, medium- or high-aromatic ultralow sulfur diesel) and driving cycles (Unified Cycle, Urban Dynamometer Driving Schedule, and creep+idle). During normal operation, vehicles with a catalyzed DPF emitted very little primary particulate matter (PM). Furthermore, photo-oxidation of dilute emissions from these vehicles produced essentially no SOA (below detection limit). However, significant primary PM emissions and SOA production were measured during active DPF regeneration experiments. Nevertheless, under reasonable assumptions about DPF regeneration frequency, the contribution of regeneration emissions to the total vehicle emissions is negligible, reducing PM trapping efficiency by less than 2%. Therefore, catalyzed DPFs appear to be very effective in reducing both primary and secondary fine particulate matter from diesel vehicles. For both MDDVs and HDDVs without aftertreatment substantial SOA formed in the smog chamber - with the emissions from some vehicles generating twice as much SOA as primary organic aerosol after three hours of oxidation at typical urban VOC : NOx ratios (3:1). Comprehensive organic gas speciation was performed on these emissions, but less than half of the measured SOA could be explained by traditional (speciated) SOA precursors. The remainder presumably originates from the large fraction (~30%) of the non-methane organic gas emissions that could not be speciated using traditional one-dimensional gas-chromatography. The unspeciated organics - likely comprising less volatile species, such as intermediate volatility organic compounds - appear to be important SOA precursors; we estimate that the effective SOA yield (defined as the ratio of SOA mass to reacted precursor mass) was 9 ± 6% if both speciated SOA precursors and unspeciated organics are included in the analysis. SOA production from creep+idle operation was 3-4 times larger than SOA production from the same vehicle operated over the Urban Dynamometer Driving Schedule (UDDS). Fuel properties had little or no effect on primary PM emissions or SOA formation.

  1. Fine particulates over South Asia: Review and meta-analysis of PM2.5 source apportionment through receptor model.

    PubMed

    Singh, Nandita; Murari, Vishnu; Kumar, Manish; Barman, S C; Banerjee, Tirthankar

    2017-04-01

    Fine particulates (PM 2.5 ) constitute dominant proportion of airborne particulates and have been often associated with human health disorders, changes in regional climate, hydrological cycle and more recently to food security. Intrinsic properties of particulates are direct function of sources. This initiates the necessity of conducting a comprehensive review on PM 2.5 sources over South Asia which in turn may be valuable to develop strategies for emission control. Particulate source apportionment (SA) through receptor models is one of the existing tool to quantify contribution of particulate sources. Review of 51 SA studies were performed of which 48 (94%) were appeared within a span of 2007-2016. Almost half of SA studies (55%) were found concentrated over few typical urban stations (Delhi, Dhaka, Mumbai, Agra and Lahore). Due to lack of local particulate source profile and emission inventory, positive matrix factorization and principal component analysis (62% of studies) were the primary choices, followed by chemical mass balance (CMB, 18%). Metallic species were most regularly used as source tracers while use of organic molecular markers and gas-to-particle conversion were minimum. Among all the SA sites, vehicular emissions (mean ± sd: 37 ± 20%) emerged as most dominating PM 2.5 source followed by industrial emissions (23 ± 16%), secondary aerosols (22 ± 12%) and natural sources (20 ± 15%). Vehicular emissions (39 ± 24%) also identified as dominating source for highly polluted sites (PM 2.5 >100 μgm -3 , n = 15) while site specific influence of either or in combination of industrial, secondary aerosols and natural sources were recognized. Source specific trends were considerably varied in terms of region and seasonality. Both natural and industrial sources were most influential over Pakistan and Afghanistan while over Indo-Gangetic plain, vehicular, natural and industrial emissions appeared dominant. Influence of vehicular emission was found single dominating source over southern part while over Bangladesh, both vehicular, biomass burning and industrial sources were significant. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Cost Effectiveness Of Selected Roadway Dust Control Methods For Eagle River, Alaska

    DOT National Transportation Integrated Search

    1988-01-01

    The U.S. Environmental Protection Agency has set air quality standards for airborne particulates with diameters equal to or less than ten microns (PM10 particulates). These particulates have been correlated with respiratory illnesses. The primary sta...

  3. CHARACTERIZATION OF EMISSIONS FROM BURNING INCENSE

    EPA Science Inventory

    The primary objective of this study was to improve the characterization of particulate matter emissions from burning incense. Emissions of particulate matter were measured for 23 different types of incense using a cyclone/filter method. Emission rates for PM2.5 (particulate matte...

  4. SEASONAL EFFECTS OF ULTRAFINE, FINE, AND COARSE PARTICULATE MATTER (PM) ON HUMAN PRIMARY AIRWAY EPITHELIAL CELLS

    EPA Science Inventory

    SEASONAL EFFECTS OF ULTRAFINE, FINE, AND COARSE PARTICULATE MATTER (PM) ON HUMAN PRIMARY AIRWAY EPITHELIAL CELLS

    Exposure of humans to PM results in increased mortality and morbidity. Recent toxicology studies have shown a number of pathophysiological pulmonary and car...

  5. Global patterns and predictions of seafloor biomass using random forests.

    PubMed

    Wei, Chih-Lin; Rowe, Gilbert T; Escobar-Briones, Elva; Boetius, Antje; Soltwedel, Thomas; Caley, M Julian; Soliman, Yousria; Huettmann, Falk; Qu, Fangyuan; Yu, Zishan; Pitcher, C Roland; Haedrich, Richard L; Wicksten, Mary K; Rex, Michael A; Baguley, Jeffrey G; Sharma, Jyotsna; Danovaro, Roberto; MacDonald, Ian R; Nunnally, Clifton C; Deming, Jody W; Montagna, Paul; Lévesque, Mélanie; Weslawski, Jan Marcin; Wlodarska-Kowalczuk, Maria; Ingole, Baban S; Bett, Brian J; Billett, David S M; Yool, Andrew; Bluhm, Bodil A; Iken, Katrin; Narayanaswamy, Bhavani E

    2010-12-30

    A comprehensive seafloor biomass and abundance database has been constructed from 24 oceanographic institutions worldwide within the Census of Marine Life (CoML) field projects. The machine-learning algorithm, Random Forests, was employed to model and predict seafloor standing stocks from surface primary production, water-column integrated and export particulate organic matter (POM), seafloor relief, and bottom water properties. The predictive models explain 63% to 88% of stock variance among the major size groups. Individual and composite maps of predicted global seafloor biomass and abundance are generated for bacteria, meiofauna, macrofauna, and megafauna (invertebrates and fishes). Patterns of benthic standing stocks were positive functions of surface primary production and delivery of the particulate organic carbon (POC) flux to the seafloor. At a regional scale, the census maps illustrate that integrated biomass is highest at the poles, on continental margins associated with coastal upwelling and with broad zones associated with equatorial divergence. Lowest values are consistently encountered on the central abyssal plains of major ocean basins The shift of biomass dominance groups with depth is shown to be affected by the decrease in average body size rather than abundance, presumably due to decrease in quantity and quality of food supply. This biomass census and associated maps are vital components of mechanistic deep-sea food web models and global carbon cycling, and as such provide fundamental information that can be incorporated into evidence-based management.

  6. Global Patterns and Predictions of Seafloor Biomass Using Random Forests

    PubMed Central

    Wei, Chih-Lin; Rowe, Gilbert T.; Escobar-Briones, Elva; Boetius, Antje; Soltwedel, Thomas; Caley, M. Julian; Soliman, Yousria; Huettmann, Falk; Qu, Fangyuan; Yu, Zishan; Pitcher, C. Roland; Haedrich, Richard L.; Wicksten, Mary K.; Rex, Michael A.; Baguley, Jeffrey G.; Sharma, Jyotsna; Danovaro, Roberto; MacDonald, Ian R.; Nunnally, Clifton C.; Deming, Jody W.; Montagna, Paul; Lévesque, Mélanie; Weslawski, Jan Marcin; Wlodarska-Kowalczuk, Maria; Ingole, Baban S.; Bett, Brian J.; Billett, David S. M.; Yool, Andrew; Bluhm, Bodil A.; Iken, Katrin; Narayanaswamy, Bhavani E.

    2010-01-01

    A comprehensive seafloor biomass and abundance database has been constructed from 24 oceanographic institutions worldwide within the Census of Marine Life (CoML) field projects. The machine-learning algorithm, Random Forests, was employed to model and predict seafloor standing stocks from surface primary production, water-column integrated and export particulate organic matter (POM), seafloor relief, and bottom water properties. The predictive models explain 63% to 88% of stock variance among the major size groups. Individual and composite maps of predicted global seafloor biomass and abundance are generated for bacteria, meiofauna, macrofauna, and megafauna (invertebrates and fishes). Patterns of benthic standing stocks were positive functions of surface primary production and delivery of the particulate organic carbon (POC) flux to the seafloor. At a regional scale, the census maps illustrate that integrated biomass is highest at the poles, on continental margins associated with coastal upwelling and with broad zones associated with equatorial divergence. Lowest values are consistently encountered on the central abyssal plains of major ocean basins The shift of biomass dominance groups with depth is shown to be affected by the decrease in average body size rather than abundance, presumably due to decrease in quantity and quality of food supply. This biomass census and associated maps are vital components of mechanistic deep-sea food web models and global carbon cycling, and as such provide fundamental information that can be incorporated into evidence-based management. PMID:21209928

  7. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shao, Huifang; Lam, William; Remias, Joseph

    Mobile source emissions standards are becoming more stringent and particulate emissions from gasoline direct injection (GDI) engines represent a particular challenge. Gasoline particulate filter (GPF) is deemed as one possible technical solution for particulate emissions reduction. In this work, a study was conducted on eight formulations of lubricants to determine their effect on GDI engine particulate emissions and GPF performance. Accelerated ash loading tests were conducted on a 2.4L GDI engine with engine oil injection in gasoline fuel by 2%. The matrix of eight formulations was designed with changing levels of sulfated ash (SASH) level, Zinc dialkyldithiophosphates (ZDDP) level andmore » detergent type. Comprehensive evaluations of particulates included mass, number, size distribution, composition, morphology and soot oxidation properties. GPF performance was assessed through filtration efficiency, back pressure and morphology. It was determined that oil formulation affects the particulate emission characteristics and subsequent GPF performance.« less

  8. 77 FR 30248 - Approval and Promulgation of Implementation Plans; State of Idaho; Regional Haze State...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-22

    ... range (or deciview), which is the greatest distance, in kilometers or miles, at which a dark object can... Comprehensive Air Quality Model with Extensions (CAMx) and Particulate Matter Source Apportionment Technology... air for NO X , wet flue gas desulfurization for SO 2 and the existing baghouse for particulate matter...

  9. Constraints on primary and secondary particulate carbon sources using chemical tracer and 14C methods during CalNex-Bakersfield

    EPA Science Inventory

    The present study investigates primary and secondary sources of organic carbon for Bakersfield, CA, USA as part of the 2010 CalNex study. The method used here involves integrated sampling that is designed to allow for detailed and specific chemical analysis of particulate matter ...

  10. Turkish Primary Students' Conceptions about the Particulate Nature of Matter

    ERIC Educational Resources Information Center

    Ozmen, Haluk

    2011-01-01

    This study was conducted to determine 4th, 5th, and 6th grade primary students' conceptions about the particulate nature of matter in daily-life events. Five questions were asked of students and interviews were used to collect data. The interviews were conducted with 12 students, four students from each grade, after they finished the formal…

  11. A COMPARISON OF THE UCD/CIT AIR QUALITY MODEL AND THE CMB SOURCE-RECEPTOR MODEL FOR PRIMARY AIRBORNE PARTICULATE MATTER. (R831082)

    EPA Science Inventory

    Source contributions to primary airborne particulate matter calculated using the source-oriented UCD/CIT air quality model and the receptor-oriented chemical mass balance (CMB) model are compared for two air quality episodes in different parts of California. The first episode ...

  12. Size and chemical characterization of airborne particulate matter in Spokane

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Haller, L.; Claiborn, C.; Westberg, H.

    1996-12-31

    Recent health effects studies suggest that the present air quality standard for aerosols, which is based upon respirable particles, does not adequately protect public health; Thus the standard is currently under review. In July, 1994, a comprehensive study was initiated in Spokane to study the relationship between various size fractions and chemical components of atmospheric aerosol and health effects. This study is one of the most comprehensive particulate matter studies conducted to date, and is one of a limited number of studies that have been conducted in the and west, where presumably a significant portion of the aerosol will bemore » derived from geological materials. Continuous fine and coarse particulate matter measurements are made at two location (one is in industrial area, and the other in residential area). At the residential site, particulate matter smaller than 1.0 {mu}m, and ultra fine particles are also continuously monitored, and analyzed for a variety of chemical species including elemental components, ionic species, soluble iron, elemental and organic carbon and acidity. Preliminary results indicate that the windblown dust enhances both the fine and coarse fractions of particulate matter in Spokane. Seasonal trends in chemical composition and size characterization will be examined. The relationships between the 24-hour average values and peak hourly values, as well as differences between weekday and weekend levels, will also be discussed.« less

  13. DIFFERENTIAL GENE EXPRESSION PROFILES IN RAT TRACHAEL EPITHELIAL (RTE) CELLS IN RESPONSE TO COMBUSTION-SOURCE PARTICULATE MATTER (PM) AND VANADIUM (V) A PRIMARY METAL CONSTITUENT

    EPA Science Inventory

    Differential gene expression profiles in rat tracheal epithelial (RTE) cells in response to combustion-source particulate matter (PM) and vanadium (V) a primary metal constituent
    Srikanth S. Nadadur, Janice A. Dye and Daniel L. Costa, US EPA, ORD, NHEERL (ETD, Pulmonary Toxico...

  14. Origin of particulate matter and gaseous precursors in the Paris Megacity: Results from intensive campaigns, long term measurements and modelling

    NASA Astrophysics Data System (ADS)

    Beekmann, Matthias; Petetin, Hervé; Zhang, Qijie; Prevot, André S. H.; Sciare, Jean; Gros, Valérie; Ghersi, Véronique; Rosso, Amandine; Crippa, Monica; Zotter, Peter; Freutel, Fredericke; Poulain, Laurent; Freney, Evelyne; Sellegri, Karine; Drewnick, Frank; Borbon, Agnès; Wiedensohler, Aflred; Pandis, Spyros N.; Baltensperger, Urs

    2016-04-01

    Uncertainties on the origin of primary and secondary particulate matter and its gaseous precursors in megacities is still large and needs to be reduced. A detailed characterization of air quality in Paris (France), a megacity of more than 10 million inhabitants, during two one month intensive campaigns (MEGAPOLI) and from additional one year observations (PARTICULATE and FRANCIPOL), revealed that about 70% of the fine particulate matter (PM) at urban background is transported on average into the megacity from upwind regions. While advection of sulfate is well documented for other megacities, there was a surprisingly high contribution from long-range transport for both nitrate and organic aerosol. The data set of urban local and advected PM concentrations in the Paris area were used for a thorough evaluation of the CHIMERE model and revealed error compensation for the local and advected components of organic matter and nitrate. During spring time, CHIMERE simulations overestimate the sensitivity of ammonium nitrate peaks to NH3, because (i) they underestimate the urban background NH3 levels, probably due to neglecting enhanced NH3 emissions for larger temperatures, and because they overestimate HNO3. However, from an ensemble of mobile Max-DOAS NO2 column and airborne NOy measurements around Paris, no clear sign on a NOx emission bias in the TNO-Airparif data set was made evident. The origin of organic PM was investigated by a comprehensive analysis of aerosol mass spectrometer (AMS), radiocarbon and tracer measurements during two intensive campaigns. Primary fossil fuel combustion emissions contributed less than 20% in winter and 40% in summer to carbonaceous fine PM, unexpectedly little for a megacity. Cooking activities and, during winter, residential wood burning are the major primary organic PM sources. This analysis suggests that the major part of secondary organic aerosol is of modern origin, i.e. from biogenic precursors and from wood burning. Implementation of different configurations of the volatility basis set into the CHIMERE model allowed correctly representing summertime organic aerosol (OA) peaks within the agglomeration and attributing them to biogenic secondary OA as a major source. OA build-up from anthropogenic precursors within the plume was also correctly simulated, but it was not possible to attribute it specifically to oxidation of aromatic or of semi/ intermediate volatile organic compounds. Plume build-up of PM significantly contributes to regional air quality around the Paris region.

  15. Health effects of carbon-containing particulate matter: focus on sources and recent research program results.

    PubMed

    Rohr, Annette; McDonald, Jacob

    2016-02-01

    Air pollution is a complex mixture of gas-, vapor-, and particulate-phase materials comprised of inorganic and organic species. Many of these components have been associated with adverse health effects in epidemiological and toxicological studies, including a broad spectrum of carbonaceous atmospheric components. This paper reviews recent literature on the health impacts of organic aerosols, with a focus on specific sources of organic material; it is not intended to be a comprehensive review of all the available literature. Specific emission sources reviewed include engine emissions, wood/biomass combustion emissions, biogenic emissions and secondary organic aerosol (SOA), resuspended road dust, tire and brake wear, and cooking emissions. In addition, recent findings from large toxicological and epidemiological research programs are reviewed in the context of organic PM, including SPHERES, NPACT, NERC, ACES, and TERESA. A review of the extant literature suggests that there are clear health impacts from emissions containing carbon-containing PM, but difficulty remains in apportioning responses to certain groupings of carbonaceous materials, such as organic and elemental carbon, condensed and gas phases, and primary and secondary material. More focused epidemiological and toxicological studies, including increased characterization of organic materials, would increase understanding of this issue.

  16. Determination of the Turkish Primary Students' Views about the Particulate Nature of Matter

    ERIC Educational Resources Information Center

    Ozmen, Haluk; Kenan, Osman

    2007-01-01

    This study was conducted to determine 4th, 5th, and 6th grade Turkish primary students' conceptions about the particulate nature of matter via a test. The test consists of 36 items related to the changes of microscopic properties of solid, liquid and gas matters during phase changing, cooling, heating and pressing of them. The sample of the study…

  17. Comprehensive chemical comparison of fuel composition and aerosol particles emitted from a ship diesel engine by gas chromatography atmospheric pressure chemical ionisation ultra-high resolution mass spectrometry with improved data processing routines.

    PubMed

    Rüger, Christopher P; Schwemer, Theo; Sklorz, Martin; O'Connor, Peter B; Barrow, Mark P; Zimmermann, Ralf

    2017-02-01

    The analysis of petrochemical materials and particulate matter originating from combustion sources remains a challenging task for instrumental analytical techniques. A detailed chemical characterisation is essential for addressing health and environmental effects. Sophisticated instrumentation, such as mass spectrometry coupled with chromatographic separation, is capable of a comprehensive characterisation, but needs advanced data processing methods. In this study, we present an improved data processing routine for the mass chromatogram obtained from gas chromatography hyphenated to atmospheric pressure chemical ionisation and ultra high resolution mass spectrometry. The focus of the investigation was the primary combustion aerosol samples, i.e. particulate matter extracts, as well as the corresponding fossil fuels fed to the engine. We demonstrate that utilisation of the entire transient and chromatographic information results in advantages including minimisation of ionisation artefacts and a reliable peak assignment. A comprehensive comparison of the aerosol and the feed fuel was performed by applying intensity weighted average values, compound class distribution and principle component analysis. Certain differences between the aerosol generated with the two feed fuels, diesel fuel and heavy fuel oil, as well as between the aerosol and the feed were revealed. For the aerosol from heavy fuel oil, oxidised species from the CHN and CHS class precursors of the feed were predominant, whereas the CHO x class is predominant in the combustion aerosol from light fuel oil. Furthermore, the complexity of the aerosol increases significantly compared to the feed and incorporating a higher chemical space. Coupling of atmospheric pressure chemical ionisation to gas chromatography was found to be a useful additional approach for characterisation of a combustion aerosol, especially with an automated utilisation of the information from the ultra-high resolution mass spectrometer and the chromatographic separation.

  18. Phenomenology and modeling of particulate corrosion product behavior in Hanford N Reactor primary coolant

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bechtold, D.B.

    1983-12-31

    The levels and composition of filterable corrosion products in the Hanford N Reactor Primary Loop are measurable by filtration. The suspended crud level has ranged from 0.0005 ppM to 6.482 ppM with a median 0.050 ppM. The composition approximates magnetite. The particle size distribution has been found in 31 cases to be uniformly a log normal distribution with a count median ranging from 1.10 to 2.31 microns with a median of 1.81 microns, and the geometric standard deviation ranging from 1.60 to 2.34 with a median of 1.84. An auto-correcting inline turbidimeter was found to respond to linearly to suspendedmore » crud levels over a range 0.05 to at least 6.5 ppM by direct comparison with filter sample weights. Cause of crud bursts in the primary loop were found to be power decreases. The crud transients associated with a reactor power drop, several reactor shutdowns, and several reactor startups could be modeled consistently with each other using a simple stirred-tank, first order exchange model of particulate between makeup, coolant, letdown, and loosely adherent crud on pipe walls. Over 3/10 of the average steady running particulate crud level could be accounted for by magnetically filterable particulate in the makeup feed. A simulation model of particulate transport has been coded in FORTRAN.« less

  19. Atmospheric oxidative chemistry of organic particulate emissions from fuel combustion.

    DOT National Transportation Integrated Search

    2011-03-25

    "Construction and characterization of the University of Vermont Environmental Chamber (UVMEC) : were completed in this last phase of the project. The primary function of the UVMEC is to enable : tropospheric particulate formation and aging studies to...

  20. Effect of ambient particulate matter expousre on hemostasis

    EPA Science Inventory

    Epidemiological studies have linked levels of particulate matter (PM) in ambient air to cardiovascular mortality and hospitalizations for myocardial infarction (MI) and stroke. Thrombus formation plays a primary role in potentiating acute cardiovascular events, and this study was...

  1. Analysis of the high-temperature particulate collection problem

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Razgaitis, R.

    1977-10-01

    Particulate agglomeration and separation at high temperatures and pressures are examined, with particular emphasis on the unique features of the direct-cycle application of fluidized-bed combustion. The basic long-range mechanisms of aerosol separation are examined, and the effects of high temperature and high pressure on usable collection techniques are assessed. Primary emphasis is placed on those avenues that are not currently attracting widespread research. The high-temperature, particulate-collection problem is surveyed, together with the peculiar requirements associated with operation of turbines with particulate-bearing gas streams. 238 references.

  2. Secondary aerosol production from agricultural gas precursors

    USDA-ARS?s Scientific Manuscript database

    Studies of air quality indicate that agricultural emissions may impact particulate mass concentrations through both primary and secondary processes. Increasing evidence from both laboratory and field work suggests that not only does ammonia produce secondary particulate matter, but some volatile org...

  3. Understanding chemistry behind secondary aerosol production from nitrogen and sulfur compounds from agriculture

    USDA-ARS?s Scientific Manuscript database

    Agricultural emissions impact particulate mass concentrations through both primary and secondary processes. Evidence from laboratory and field work suggest that not only does ammonia produce secondary particulate matter, but nitrogen and sulfur containing volatile organic compounds also contribute. ...

  4. Mixing method and apparatus

    DOEpatents

    Green, Norman W.

    1982-06-15

    Method of mixing particulate materials comprising contacting a primary source and a secondary source thereof whereby resulting mixture ensues; preferably at least one of the two sources has enough motion to insure good mixing and the particulate materials may be heat treated if desired. Apparatus for such mixing comprising an inlet for a primary source, a reactor communicating therewith, a feeding means for supplying a secondary source to the reactor, and an inlet for the secondary source. Feeding means is preferably adapted to supply fluidized materials.

  5. Motorcycle pollution control in Taiwan, Republic of China

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chen, H.W.; Hsiao, H.C.; Walsh, M.P.

    1998-12-31

    The Taiwan EPA has developed a comprehensive approach to motor vehicle pollution control. Building on its early adoption of US `83 standards for light duty vehicles (starting July 1, 1990) it recently moved to US `87 requirements, which include the 0.2 gram per mile particulate standard, as of July 1, 1995. Heavy duty diesel particulate standards almost as stringent as US `90, 6.0 grams per brake horsepower hour NO{sub x} and 0.7 particulate, using the US transient test procedure, went into effect on July 1, 1993. It is intended that US`94 standards, 5.0 NO{sub x} and 0.25 particulate, will bemore » adopted soon. Clearly the most distinctive feature of the Taiwan program, however, is its motorcycle control effort, reflecting the fact that motorcycles dominate the vehicle fleet and are a substantial source of emissions. This paper will summarize Taiwan`s extensive efforts to address this problem.« less

  6. Harmful impact of air pollution on severe acute exacerbation of chronic obstructive pulmonary disease: particulate matter is hazardous.

    PubMed

    Choi, Juwhan; Oh, Jee Youn; Lee, Young Seok; Min, Kyung Hoon; Hur, Gyu Young; Lee, Sung Yong; Kang, Kyung Ho; Shim, Jae Jeong

    2018-01-01

    Particulate matter and air pollution in Korea are becoming worse. There is a lack of research regarding the impact of particulate matter on patients with COPD. Therefore, the purpose of this study was to investigate the effects of various air pollution factors, including particulate matter, on the incidence rate of severe acute exacerbations of COPD (AECOPD) events. We analyzed the relationship between air pollutants and AECOPD events that required hospitalization at Guro Hospital in Korea from January 1, 2015 to May 31, 2017. We used general linear models with Poisson distribution and log-transformation to obtain adjusted relative risk (RR). We conducted further analysis through the Comprehensive Air-quality Index (CAI) that is used in Korea. Among various other air pollutants, particulate matter was identified as a major source of air pollution in Korea. When the CAI score was over 50, the incidence rate of severe AECOPD events was statistically significantly higher [RR 1.612, 95% CI, 1.065-2.440, P =0.024]. Additionally, the particulate matter levels 3 days before hospitalization were statistically significant [RR 1.003, 95% CI, 1.001-1.005, P =0.006]. Particulate matter and air pollution increase the incidence rate of severe AECOPD events. COPD patients should be cautioned against outdoor activities when particulate matter levels are high.

  7. THE RESEARCH TRIANGLE PARK PARTICULATE MATTER PANEL STUDY: PM MASS CONCENTRATION RELATIONSHIPS

    EPA Science Inventory

    The U.S. Environmental Protection Agency has recently performed the Research Triangle Park Particulate Matter Panel Study. This was a one-year investigation of PM and related co-pollutants involving participants living within the RTP area of North Carolina. Primary goals were t...

  8. ANALYSIS OF CARBONACEOUS AEROSOLS USING THE THERMAL OPTICAL TRANSMITTANCE AND THERMAL OPTICAL REFLECTANCE METHODS

    EPA Science Inventory

    Carbonaceous particulate typically represents a large fraction of PM2.5 (20 - 40%). Two primary techniques presently used for the analysis of particulate carbon are Thermal Optical Transmission (TOT - NIOSH Method 5040) and Thermal Optical Reflectance (TOR). These two methods b...

  9. INDIVIDUAL PARTICLE ANALYSIS OF PERSONAL SAMPLES FROM THE 1998 BALTIMORE PARTICULATE MATTER STUDY

    EPA Science Inventory

    The United States Environmental Protection Agency (U.S. EPA) recently conducted the 1998 Baltimore Particulate Matter (PM) Epidemiology-Exposure Study of the Elderly. The primary goal of that study was to establish the relationship between outdoor PM concentrations and actual h...

  10. Gas- and particle-phase primary emissions from in-use, on-road gasoline and diesel vehicles

    NASA Astrophysics Data System (ADS)

    May, Andrew A.; Nguyen, Ngoc T.; Presto, Albert A.; Gordon, Timothy D.; Lipsky, Eric M.; Karve, Mrunmayi; Gutierrez, Alváro; Robertson, William H.; Zhang, Mang; Brandow, Christopher; Chang, Oliver; Chen, Shiyan; Cicero-Fernandez, Pablo; Dinkins, Lyman; Fuentes, Mark; Huang, Shiou-Mei; Ling, Richard; Long, Jeff; Maddox, Christine; Massetti, John; McCauley, Eileen; Miguel, Antonio; Na, Kwangsam; Ong, Richard; Pang, Yanbo; Rieger, Paul; Sax, Todd; Truong, Tin; Vo, Thu; Chattopadhyay, Sulekha; Maldonado, Hector; Maricq, M. Matti; Robinson, Allen L.

    2014-05-01

    Tailpipe emissions from sixty-four unique light-duty gasoline vehicles (LDGVs) spanning model years 1987-2012, two medium-duty diesel vehicles and three heavy-duty diesel vehicles with varying levels of aftertreatment were characterized at the California Air Resources Board Haagen-Smit and Heavy-Duty Engine Testing Laboratories. Each vehicle was tested on a chassis dynamometer using a constant volume sampler, commercial fuels and standard duty cycles. Measurements included regulated pollutants such as carbon monoxide (CO), total hydrocarbons (THC), nitrogen oxides (NOx), and particulate matter (PM). Off-line analyses were performed to speciate gas- and particle-phase emissions. The data were used to investigate trends in emissions with vehicle age and to quantify the effects of different aftertreatment technologies on diesel vehicle emissions (e.g., with and without a diesel particulate filter). On average, newer LDGVs that met the most recent emissions standards had substantially lower emissions of regulated gaseous pollutants (CO, THC and NOx) than older vehicles. For example, THC emissions from the median LDGV that met the LEV2 standard was roughly a factor of 10 lower than the median pre-LEV vehicle; there were also substantial reductions in NOx (factor of ∼100) and CO (factor of ∼10) emissions from pre-LEV to LEV2 vehicles. However, reductions in LDGV PM mass emissions were much more modest. For example, PM emission from the median LEV2 vehicle was only a factor of three lower than the median pre-LEV vehicle, mainly due to the reductions in organic carbon emissions. In addition, LEV1 and LEV2 LDGVs had similar PM emissions. Catalyzed diesel particulate filters reduced CO, THC and PM emissions from HDDVs by one to two orders of magnitude. Comprehensive organic speciation was performed to quantify priority air toxic emissions and to estimate the secondary organic aerosol (SOA) formation potential. The data suggest that the SOA production from cold-start LDGVs exhaust will likely exceed primary PM emissions from LDGVs and could potentially exceed SOA formation from on-road diesel vehicles.

  11. ACTIVATION OF THE EGF RECEPTOR SIGNALING PATHWAY IN HUMAN AIRWAY EPITHELIAL CELLS EXPOSED TO UTAH VALLEY PARTICULATE MATTER

    EPA Science Inventory

    Exposure to ambient particulate matter (PM) in the Utah Valley (UV) has previously been associated with a variety of adverse health effects. To investigate intracellular signaling mechanisms for pulmonary responses to UV PM inhalation, human primary airway epithelial cells (NHBE)...

  12. 40 CFR 52.2276 - Control strategy and regulations: Particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... its limestone quarry facilities near New Braunfels, Comal County, Texas shall install fabric filters... of the fabric filters, Parker Brothers and Co., Inc., shall not emit particulate matter in excess of 0.03 grains per standard cubic foot from the exhaust stack of the fabric filter on its primary...

  13. 40 CFR 52.2276 - Control strategy and regulations: Particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... its limestone quarry facilities near New Braunfels, Comal County, Texas shall install fabric filters... of the fabric filters, Parker Brothers and Co., Inc., shall not emit particulate matter in excess of 0.03 grains per standard cubic foot from the exhaust stack of the fabric filter on its primary...

  14. 40 CFR 52.2276 - Control strategy and regulations: Particulate matter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... its limestone quarry facilities near New Braunfels, Comal County, Texas shall install fabric filters... of the fabric filters, Parker Brothers and Co., Inc., shall not emit particulate matter in excess of 0.03 grains per standard cubic foot from the exhaust stack of the fabric filter on its primary...

  15. Primary particulate matter from ocean-going engines in the Southern California Air Basin.

    PubMed

    Agrawal, Harshit; Eden, Rudy; Zhang, Xinqiu; Fine, Philip M; Katzenstein, Aaron; Miller, J Wayne; Ospital, Jean; Teffera, Solomon; Cocker, David R

    2009-07-15

    The impact of primary fine particulate matter (PM2.5) from ship emissions within the Southern California Air Basin is quantified by comparing in-stack vanadium (V) and nickel (Ni) measurements from in-use ocean-going vessels (OGVs) with ambient measurements made at 10 monitoring stations throughout Southern California. V and Ni are demonstrated as robust markers for the combustion of heavy fuel oil in OGVs, and ambient measurements of fine particulate V and Ni within Southern California are shown to decrease inversely with increased distance from the ports of Los Angeles and Long Beach (ports). High levels of V and Ni were observed from in-stack emission measurements conducted on the propulsion engines of two different in-use OGVs. The in-stack V and Ni emission rates (g/h) normalized by the V and Ni contents in the fuel tested correlates with the stack total PM emission rates (g/h). The normalized emission rates are used to estimate the primary PM2.5 contributions from OGVs at 10 monitoring locations within Southern California. Primary PM2.5 contributions from OGVs were found to range from 8.8% of the total PM2.5 at the monitoring location closest to the port (West Long Beach) to 1.4% of the total PM2.5 at the monitoring location 80 km inland (Rubidoux). The calculated OGV contributions to ambient PM2.5 measurements at the 10 monitoring sites agree well with estimates developed using an emission inventory based regional model. Results of this analysis will be useful in determining the impacts of primary particulate emissions from OGVs upon worldwide communities downwind of port operations.

  16. Air quality during demolition and recovery activities in post-Katrina New Orleans.

    PubMed

    Ravikrishna, Raghunathan; Lee, Han-Woong; Mbuligwe, Stephen; Valsaraj, K T; Pardue, John H

    2010-07-01

    Air samples were collected during demolition and cleanup operations in the Lakeview district of New Orleans, Louisiana, USA, in late 2005 during the period immediately after Hurricane Katrina. Three different high-volume air samples were collected around waste collection areas that were created to temporarily hold the debris from the cleanup of residential properties in the area. Particulate concentrations were elevated and included crystalline fibers associated with asbestos. Metal concentrations on particulate matter resembled those measured in sediments deposited by floodwaters with the exception of Ba, which was elevated at all three locations. The highest organic contaminant concentration measured on particulates was the pesticide Ziram (Zinc, bis[diethylcarbamodithioato-S,S']-, [T-4]-) at 2,200 microg/g of particulate matter during sampling period 2. Ziram is used in latex paint, adhesives, caulking, and wallboard as a preservative. Fungal isolates developed from particulate air samples included species associated with disease including Aspergillus and Penicillium species. These data represent the most comprehensive assessment of demolition activities during the period immediately after Hurricane Katrina. Copyright (c) 2010 SETAC.

  17. Modeling Gas-Aerosol Processes during MILAGRO 2006

    NASA Astrophysics Data System (ADS)

    Zaveri, R. A.; Chapman, E. G.; Easter, R. C.; Fast, J. D.; Flocke, F.; Kleinman, L. I.; Madronich, S.; Springston, S. R.; Voss, P. B.; Weinheimer, A.

    2007-12-01

    Significant gas-aerosol interactions are expected in the Mexico City outflow due to formation of various semi- volatile secondary inorganic and organic gases that can partition into the particulate phase and due to various heterogeneous chemical processes. A number of T0-T1-T2 Lagrangian transport episodes during the MILAGRO campaign provide focused modeling opportunities to elucidate the roles of various chemical and physical processes in the evolution of the primary trace gases and aerosol particles emitted in Mexico City over a period of 4-8 hours. Additionally, one long-range Lagrangian transport episode on March 18-19, 2006, as characterized by the Controlled Meteorological (CMET) balloon trajectories, presents an excellent opportunity to model evolution of Mexico City pollutants over 26 hours. The key tools in our analysis of these Lagrangian episodes include a comprehensive Lagrangian box-model and the WRF-chem model based on the new Model for Simulating Aerosol Interactions and Chemistry (MOSAIC), which simulates gas-phase photochemistry, heterogeneous reactions, equilibrium particulate phase-state and water content, and dynamic gas-particle partitioning for size- resolved aerosols. Extensive gas, aerosol, and meteorological measurements onboard the G1 and C130 aircraft and T0, T1, and T2 ground sites will be used to initialize, constrain, and evaluate the models. For the long-range transport event, in-situ vertical profiles of wind vectors from repeated CMET balloon soundings in the Mexico City outflow will be used to nudge the winds in the WRF-chem simulation. Preliminary model results will be presented with the intention to explore further collaborative opportunities to use additional gas and particulate measurements to better constrain and evaluate the models.

  18. Air pollution: Household soiling and consumer welfare losses

    USGS Publications Warehouse

    Watson, W.D.; Jaksch, J.A.

    1982-01-01

    This paper uses demand and supply functions for cleanliness to estimate household benefits from reduced particulate matter soiling. A demand curve for household cleanliness is estimated, based upon the assumption that households prefer more cleanliness to less. Empirical coefficients, related to particulate pollution levels, for shifting the cleanliness supply curve, are taken from available studies. Consumer welfare gains, aggregated across 123 SMSAs, from achieving the Federal primary particulate standard, are estimated to range from $0.9 to $3.2 million per year (1971 dollars). ?? 1982.

  19. In situ, satellite measurement and model evidence on the dominant regional contribution to fine particulate matter levels in the Paris megacity

    NASA Astrophysics Data System (ADS)

    Beekmann, M.; Prévôt, A. S. H.; Drewnick, F.; Sciare, J.; Pandis, S. N.; Denier van der Gon, H. A. C.; Crippa, M.; Freutel, F.; Poulain, L.; Ghersi, V.; Rodriguez, E.; Beirle, S.; Zotter, P.; von der Weiden-Reinmüller, S.-L.; Bressi, M.; Fountoukis, C.; Petetin, H.; Szidat, S.; Schneider, J.; Rosso, A.; El Haddad, I.; Megaritis, A.; Zhang, Q. J.; Michoud, V.; Slowik, J. G.; Moukhtar, S.; Kolmonen, P.; Stohl, A.; Eckhardt, S.; Borbon, A.; Gros, V.; Marchand, N.; Jaffrezo, J. L.; Schwarzenboeck, A.; Colomb, A.; Wiedensohler, A.; Borrmann, S.; Lawrence, M.; Baklanov, A.; Baltensperger, U.

    2015-08-01

    A detailed characterization of air quality in the megacity of Paris (France) during two 1-month intensive campaigns and from additional 1-year observations revealed that about 70 % of the urban background fine particulate matter (PM) is transported on average into the megacity from upwind regions. This dominant influence of regional sources was confirmed by in situ measurements during short intensive and longer-term campaigns, aerosol optical depth (AOD) measurements from ENVISAT, and modeling results from PMCAMx and CHIMERE chemistry transport models. While advection of sulfate is well documented for other megacities, there was surprisingly high contribution from long-range transport for both nitrate and organic aerosol. The origin of organic PM was investigated by comprehensive analysis of aerosol mass spectrometer (AMS), radiocarbon and tracer measurements during two intensive campaigns. Primary fossil fuel combustion emissions constituted less than 20 % in winter and 40 % in summer of carbonaceous fine PM, unexpectedly small for a megacity. Cooking activities and, during winter, residential wood burning are the major primary organic PM sources. This analysis suggests that the major part of secondary organic aerosol is of modern origin, i.e., from biogenic precursors and from wood burning. Black carbon concentrations are on the lower end of values encountered in megacities worldwide, but still represent an issue for air quality. These comparatively low air pollution levels are due to a combination of low emissions per inhabitant, flat terrain, and a meteorology that is in general not conducive to local pollution build-up. This revised picture of a megacity only being partially responsible for its own average and peak PM levels has important implications for air pollution regulation policies.

  20. In-situ, satellite measurement and model evidence for a~dominant regional contribution to fine particulate matter levels in the Paris Megacity

    NASA Astrophysics Data System (ADS)

    Beekmann, M.; Prévôt, A. S. H.; Drewnick, F.; Sciare, J.; Pandis, S. N.; Denier van der Gon, H. A. C.; Crippa, M.; Freutel, F.; Poulain, L.; Ghersi, V.; Rodriguez, E.; Beirle, S.; Zotter, P.; von der Weiden-Reinmüller, S.-L.; Bressi, M.; Fountoukis, C.; Petetin, H.; Szidat, S.; Schneider, J.; Rosso, A.; El Haddad, I.; Megaritis, A.; Zhang, Q. J.; Michoud, V.; Slowik, J. G.; Moukhtar, S.; Kolmonen, P.; Stohl, A.; Eckhardt, S.; Borbon, A.; Gros, V.; Marchand, N.; Jaffrezo, J. L.; Schwarzenboeck, A.; Colomb, A.; Wiedensohler, A.; Borrmann, S.; Lawrence, M.; Baklanov, A.; Baltensperger, U.

    2015-03-01

    A detailed characterization of air quality in Paris (France), a megacity of more than 10 million inhabitants, during two one month intensive campaigns and from additional one year observations, revealed that about 70% of the fine particulate matter (PM) at urban background is transported on average into the megacity from upwind regions. This dominant influence of regional sources was confirmed by in-situ measurements during short intensive and longer term campaigns, aerosol optical depth (AOD) measurements from ENVISAT, and modeling results from PMCAMx and CHIMERE. While advection of sulfate is well documented for other megacities, there was surprisingly high contribution from long-range transport for both nitrate and organic aerosol. The origin of organic PM was investigated by a comprehensive analysis of aerosol mass spectrometer (AMS), radiocarbon and tracer measurements during two intensive campaigns. Primary fossil fuel combustion emissions contributed less than 20% in winter and 40% in summer to carbonaceous fine PM, unexpectedly little for a megacity. Cooking activities and, during winter, residential wood burning are the major primary organic PM sources. This analysis suggests that the major part of secondary organic aerosol is of modern origin, i.e. from biogenic precursors and from wood burning. Black carbon concentrations are on the lower end of values encountered in megacities worldwide, but still represent an issue for air quality. These comparatively low air pollution levels are due to a combination of low emissions per inhabitant, flat terrain, and a meteorology that is in general not conducive to local pollution build-up. This revised picture of a megacity only controlling part of its own average and peak PM levels has important implications for air pollution regulation policies.

  1. SUPERSITES INTEGRATED RELATIONAL DATABASE (SIRD)

    EPA Science Inventory

    As part of EPA's Particulate Matter (PM) Supersites Program (Program), the University of Maryland designed and developed the Supersites Integrated Relational Database (SIRD). Measurement data in SIRD include comprehensive air quality data from the 7 Supersite program locations f...

  2. Comprehensive modeling of a liquid rocket combustion chamber

    NASA Technical Reports Server (NTRS)

    Liang, P.-Y.; Fisher, S.; Chang, Y. M.

    1985-01-01

    An analytical model for the simulation of detailed three-phase combustion flows inside a liquid rocket combustion chamber is presented. The three phases involved are: a multispecies gaseous phase, an incompressible liquid phase, and a particulate droplet phase. The gas and liquid phases are continuum described in an Eulerian fashion. A two-phase solution capability for these continuum media is obtained through a marriage of the Implicit Continuous Eulerian (ICE) technique and the fractional Volume of Fluid (VOF) free surface description method. On the other hand, the particulate phase is given a discrete treatment and described in a Lagrangian fashion. All three phases are hence treated rigorously. Semi-empirical physical models are used to describe all interphase coupling terms as well as the chemistry among gaseous components. Sample calculations using the model are given. The results show promising application to truly comprehensive modeling of complex liquid-fueled engine systems.

  3. Are Atoms and Molecules Too Difficult for Primary Children?

    ERIC Educational Resources Information Center

    Skamp, Keith

    1999-01-01

    Presents evidence that suggests that upper elementary students can be taught about the particulate nature of matter in a meaningful way. Investigated the effects of lesson sequences on children's ability to apply a particulate understanding to chemical and physical phenomena and found conceptual gains on lesson specific phenomena. (Contains 15…

  4. Chemical transport model simulations of organic aerosol in southern California: model evaluation and gasoline and diesel source contributions

    EPA Science Inventory

    Gasoline- and diesel-fueled engines are ubiquitous sources of air pollution in urban environments. They emit both primary particulate matter and precursor gases that react to form secondary particulate matter in the atmosphere. In this work, we updated the organic aerosol module ...

  5. 78 FR 23492 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Particulate Matter Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-19

    ... Promulgation of Air Quality Implementation Plans; Indiana; Particulate Matter Air Quality Standards AGENCY... submission contains the 24-hour fine particle (PM 2.5 ) National Ambient Air Quality Standards (NAAQS..., ``National primary and secondary ambient air quality standards for PM 2.5 .'' In the submission, IDEM has...

  6. PRODUCTION OF SHEET FROM PARTICULATE MATERIAL

    DOEpatents

    Blainey, A.

    1959-05-12

    A process is presented for forming coherent sheet material from particulate material such as granular or powdered metal, granular or powdered oxide, slurries, pastes, and plastic mixes which cohere under pressure. The primary object is to avoid the use of expensive and/ or short lived pressing tools, that is, dies and specially profiled rolls, and so to reduce the cost of the product and to prcvide in a simple manner for the making of the product in a variety of shapes or sizes. The sheet material is formed when the particulate material is laterally confined in a boundary material deformable in all lateral directions under axial pressure and then axially compressing the layer of particulate material together with the boundary material.

  7. Secondary organic aerosol production from diesel vehicle exhaust: impact of aftertreatment, fuel chemistry and driving cycle

    NASA Astrophysics Data System (ADS)

    Gordon, T. D.; Presto, A. A.; Nguyen, N. T.; Robertson, W. H.; Na, K.; Sahay, K. N.; Zhang, M.; Maddox, C.; Rieger, P.; Chattopadhyay, S.; Maldonado, H.; Maricq, M. M.; Robinson, A. L.

    2014-05-01

    Environmental chamber ("smog chamber") experiments were conducted to investigate secondary organic aerosol (SOA) production from dilute emissions from two medium-duty diesel vehicles (MDDVs) and three heavy-duty diesel vehicles (HDDVs) under urban-like conditions. Some of the vehicles were equipped with emission control aftertreatment devices, including diesel particulate filters (DPFs), selective catalytic reduction (SCR) and diesel oxidation catalysts (DOCs). Experiments were also performed with different fuels (100% biodiesel and low-, medium- or high-aromatic ultralow sulfur diesel) and driving cycles (Unified Cycle,~Urban Dynamometer Driving Schedule, and creep + idle). During normal operation, vehicles with a catalyzed DPF emitted very little primary particulate matter (PM). Furthermore, photooxidation of dilute emissions from these vehicles produced essentially no SOA (below detection limit). However, significant primary PM emissions and SOA production were measured during active DPF regeneration experiments. Nevertheless, under reasonable assumptions about DPF regeneration frequency, the contribution of regeneration emissions to the total vehicle emissions is negligible, reducing PM trapping efficiency by less than 2%. Therefore, catalyzed DPFs appear to be very effective in reducing both primary PM emissions and SOA production from diesel vehicles. For both MDDVs and HDDVs without aftertreatment substantial SOA formed in the smog chamber - with the emissions from some vehicles generating twice as much SOA as primary organic aerosol after 3 h of oxidation at typical urban VOC / NOx ratios (3 : 1). Comprehensive organic gas speciation was performed on these emissions, but less than half of the measured SOA could be explained by traditional (speciated) SOA precursors. The remainder presumably originates from the large fraction (~30%) of the nonmethane organic gas emissions that could not be speciated using traditional one-dimensional gas chromatography. The unspeciated organics - likely comprising less volatile species such as intermediate volatility organic compounds - appear to be important SOA precursors; we estimate that the effective SOA yield (defined as the ratio of SOA mass to reacted precursor mass) was 9 ± 6% if both speciated SOA precursors and unspeciated organics are included in the analysis. SOA production from creep + idle operation was 3-4 times larger than SOA production from the same vehicle operated over the Urban Dynamometer Driving Schedule (UDDS). Fuel properties had little or no effect on primary PM emissions or SOA formation.

  8. THE RESEARCH TRIANGLE PARK PARTICULATE MATTER PANEL STUDY: MODELING AMBIENT SOURCE CONTRIBUTION TO PERSONAL AND RESIDENTIAL PM MASS CONCENTRATIONS

    EPA Science Inventory

    The Research Triangle Park (RTP) Particulate Matter (PM) Panel Study represented a one-year investigation of personal, residential and ambient PM mass concentrations across distances as large as 70 km in central North Carolina. One of the primary goals of this effort was to est...

  9. 40 CFR Table 2 to Subpart Fffff of... - Initial Compliance With Emission and Opacity Limits

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... flow-weighted average concentration of particulate matter from one or more control devices applied to...). 4. Each discharge end at a new sinter plant a. The flow-weighted average concentration of... BOPF at a new or existing BOPF shop a. The average concentration of particulate matter from a primary...

  10. 40 CFR Table 2 to Subpart Fffff of... - Initial Compliance With Emission and Opacity Limits

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... flow-weighted average concentration of particulate matter from one or more control devices applied to...). 4. Each discharge end at a new sinter plant a. The flow-weighted average concentration of... BOPF at a new or existing BOPF shop a. The average concentration of particulate matter from a primary...

  11. 40 CFR Table 2 to Subpart Fffff of... - Initial Compliance With Emission and Opacity Limits

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... flow-weighted average concentration of particulate matter from one or more control devices applied to...). 4. Each discharge end at a new sinter plant a. The flow-weighted average concentration of... BOPF at a new or existing BOPF shop a. The average concentration of particulate matter from a primary...

  12. 40 CFR Table 2 to Subpart Fffff of... - Initial Compliance With Emission and Opacity Limits

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... flow-weighted average concentration of particulate matter from one or more control devices applied to...). 4. Each discharge end at a new sinter plant a. The flow-weighted average concentration of... BOPF at a new or existing BOPF shop a. The average concentration of particulate matter from a primary...

  13. Deep-sea fluxes of barium and lithogenic trace elements in the subtropical northeast Atlantic

    NASA Astrophysics Data System (ADS)

    Stern, Judith; Dellwig, Olaf; Waniek, Joanna J.

    2017-04-01

    Total particle flux, Barium and lithogenic trace element fluxes were measured at the mooring Kiel 276 (33°N, 22°W) in the deep-sea of the subtropical Northeast Atlantic. The particulate material was collected between 2002 and 2008 with a sediment trap in 2000 m depth and analyzed with ICP-OES/-MS to determine its geochemical composition. The particle flux is controlled by primary production, lithogenic particle inputs via atmospheric transport and the migration of the Azores Front. We used refractory trace elements (eg. Ti, Zr, and the rare earth elements) to demonstrate the changes in flux and composition of the material due to lithogenic inputs. Shortly after periods of high dust load and enhanced primary production an increase in lithogenic trace element fluxes occurred. Especially the formation of aggregates with biogenic matter seems to have a major impact on the downwards transport of lithogenic particles. The observation of particulate Ba is of great interest since it is known as a proxy for past and present primary production. Ba fluxes ranging between 0.02 mg m-2 d-1 and 1.21 mg m-2 d-1 with biogenic proportions up to 97%. The fluxes of particulate Barium in the water column are mainly attributed to the strength of primary production.

  14. Real-Time Measurements and Characterization of Airborne Particulate Matter from a Primary Silicon Carbide Production Plant.

    PubMed

    Jørgensen, Rikke Bramming; Kero, Ida Teresia

    2017-12-20

    Airborne particulate matter in the silicon carbide (SiC) industry is a known health hazard. The aims of this study were to elucidate whether the particulate matter generated inside the Acheson furnace during active operation is representative of the overall particulate matter in the furnace hall, and whether the Acheson furnaces are the main sources of ultrafine particles (UFP) in primary SiC production. The number concentration of ultrafine particles was evaluated using an Electrical Low Pressure Impactor (ELPI TM , Dekati Ltd., Tampere, Finland), a Fast Mobility Particle Sizer (FMPS TM , TSI, Shoreview, MN, USA) and a Condensation Particle Counter (CPC, TSI, Shoreview, MN, USA). The results are discussed in terms of particle number concentration, particle size distribution and are also characterized by means of electron microscopy (TEM/SEM). Two locations were investigated; the industrial Acheson process furnace hall and a pilot furnace hall; both of which represent an active operating furnace. The geometric mean of the particle number concentration in the Acheson process furnace hall was 7.7 × 10⁴ particles/cm³ for the UFP fraction and 1.0 × 10⁵ particles/cm³ for the submicrometre fraction. Particulate matter collected at the two sites was analysed by electron microscopy. The PM from the Acheson process furnace hall is dominated by carbonaceous particles while the samples collected near the pilot furnace are primarily rich in silicon.

  15. Real-Time Measurements and Characterization of Airborne Particulate Matter from a Primary Silicon Carbide Production Plant

    PubMed Central

    2017-01-01

    Airborne particulate matter in the silicon carbide (SiC) industry is a known health hazard. The aims of this study were to elucidate whether the particulate matter generated inside the Acheson furnace during active operation is representative of the overall particulate matter in the furnace hall, and whether the Acheson furnaces are the main sources of ultrafine particles (UFP) in primary SiC production. The number concentration of ultrafine particles was evaluated using an Electrical Low Pressure Impactor (ELPITM, Dekati Ltd., Tampere, Finland), a Fast Mobility Particle Sizer (FMPSTM, TSI, Shoreview, MN, USA) and a Condensation Particle Counter (CPC, TSI, Shoreview, MN, USA). The results are discussed in terms of particle number concentration, particle size distribution and are also characterized by means of electron microscopy (TEM/SEM). Two locations were investigated; the industrial Acheson process furnace hall and a pilot furnace hall; both of which represent an active operating furnace. The geometric mean of the particle number concentration in the Acheson process furnace hall was 7.7 × 104 particles/cm3 for the UFP fraction and 1.0 × 105 particles/cm3 for the submicrometre fraction. Particulate matter collected at the two sites was analysed by electron microscopy. The PM from the Acheson process furnace hall is dominated by carbonaceous particles while the samples collected near the pilot furnace are primarily rich in silicon. PMID:29261158

  16. Particulate emissions from diesel engines: correlation between engine technology and emissions.

    PubMed

    Fiebig, Michael; Wiartalla, Andreas; Holderbaum, Bastian; Kiesow, Sebastian

    2014-03-07

    In the last 30 years, diesel engines have made rapid progress to increased efficiency, environmental protection and comfort for both light- and heavy-duty applications. The technical developments include all issues from fuel to combustion process to exhaust gas aftertreatment. This paper provides a comprehensive summary of the available literature regarding technical developments and their impact on the reduction of pollutant emission. This includes emission legislation, fuel quality, diesel engine- and exhaust gas aftertreatment technologies, as well as particulate composition, with a focus on the mass-related particulate emission of on-road vehicle applications. Diesel engine technologies representative of real-world on-road applications will be highlighted.Internal engine modifications now make it possible to minimize particulate and nitrogen oxide emissions with nearly no reduction in power. Among these modifications are cooled exhaust gas recirculation, optimized injections systems, adapted charging systems and optimized combustion processes with high turbulence. With introduction and optimization of exhaust gas aftertreatment systems, such as the diesel oxidation catalyst and the diesel particulate trap, as well as NOx-reduction systems, pollutant emissions have been significantly decreased. Today, sulfur poisoning of diesel oxidation catalysts is no longer considered a problem due to the low-sulfur fuel used in Europe. In the future, there will be an increased use of bio-fuels, which generally have a positive impact on the particulate emissions and do not increase the particle number emissions.Since the introduction of the EU emissions legislation, all emission limits have been reduced by over 90%. Further steps can be expected in the future. Retrospectively, the particulate emissions of modern diesel engines with respect to quality and quantity cannot be compared with those of older engines. Internal engine modifications lead to a clear reduction of the particulate emissions without a negative impact on the particulate-size distribution towards smaller particles. The residual particles can be trapped in a diesel particulate trap independent of their size or the engine operating mode. The usage of a wall-flow diesel particulate filter leads to an extreme reduction of the emitted particulate mass and number, approaching 100%. A reduced particulate mass emission is always connected to a reduced particle number emission.

  17. Particulate emissions from diesel engines: correlation between engine technology and emissions

    PubMed Central

    2014-01-01

    In the last 30 years, diesel engines have made rapid progress to increased efficiency, environmental protection and comfort for both light- and heavy-duty applications. The technical developments include all issues from fuel to combustion process to exhaust gas aftertreatment. This paper provides a comprehensive summary of the available literature regarding technical developments and their impact on the reduction of pollutant emission. This includes emission legislation, fuel quality, diesel engine- and exhaust gas aftertreatment technologies, as well as particulate composition, with a focus on the mass-related particulate emission of on-road vehicle applications. Diesel engine technologies representative of real-world on-road applications will be highlighted. Internal engine modifications now make it possible to minimize particulate and nitrogen oxide emissions with nearly no reduction in power. Among these modifications are cooled exhaust gas recirculation, optimized injections systems, adapted charging systems and optimized combustion processes with high turbulence. With introduction and optimization of exhaust gas aftertreatment systems, such as the diesel oxidation catalyst and the diesel particulate trap, as well as NOx-reduction systems, pollutant emissions have been significantly decreased. Today, sulfur poisoning of diesel oxidation catalysts is no longer considered a problem due to the low-sulfur fuel used in Europe. In the future, there will be an increased use of bio-fuels, which generally have a positive impact on the particulate emissions and do not increase the particle number emissions. Since the introduction of the EU emissions legislation, all emission limits have been reduced by over 90%. Further steps can be expected in the future. Retrospectively, the particulate emissions of modern diesel engines with respect to quality and quantity cannot be compared with those of older engines. Internal engine modifications lead to a clear reduction of the particulate emissions without a negative impact on the particulate-size distribution towards smaller particles. The residual particles can be trapped in a diesel particulate trap independent of their size or the engine operating mode. The usage of a wall-flow diesel particulate filter leads to an extreme reduction of the emitted particulate mass and number, approaching 100%. A reduced particulate mass emission is always connected to a reduced particle number emission. PMID:24606725

  18. Analysis of suspended solids by single-particle scattering. [for Lake Superior pollution monitoring

    NASA Technical Reports Server (NTRS)

    Diehl, S. R.; Smith, D. T.; Sydor, M.

    1979-01-01

    Light scattering by individual particulates is used in a multiple-detector system to categorize the composition of suspended solids in terms of broad particulate categories. The scattering signatures of red clay and taconite tailings, the two primary particulate contaminants in western Lake Superior, along with two types of asbestiform fibers, amphibole and chrysolite, were studied in detail. A method was developed to predict the concentration of asbestiform fibers in filtration plant samples for which electron microscope analysis was done concurrently. Fiber levels as low as 50,000 fibers/liter were optically detectable. The method has application in optical categorization of samples for remote sensing purposes and offers a fast, inexpensive means for analyzing water samples from filtration plants for specific particulate contaminants.

  19. Effect of PDEODE Teaching Strategy on Turkish Students' Conceptual Understanding: Particulate Nature of Matter

    ERIC Educational Resources Information Center

    Demircioglu, Hülya

    2017-01-01

    The aim of this study is to determine the effect of activities developed in accordance with PDEODE teaching strategy on students' understanding of the particulate nature of matter. The sample of the study consists of the first grade students who study in the Primary School Teacher Education Program. In order to determine the conceptual change on…

  20. Ocean subsurface particulate backscatter estimation from CALIPSO spaceborne lidar measurements

    NASA Astrophysics Data System (ADS)

    Chen, Peng; Pan, Delu; Wang, Tianyu; Mao, Zhihua

    2017-10-01

    A method for ocean subsurface particulate backscatter estimation from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) on the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite was demonstrated. The effects of the CALIOP receiver's transient response on the attenuated backscatter profile were first removed. The two-way transmittance of the overlying atmosphere was then estimated as the ratio of the measured ocean surface attenuated backscatter to the theoretical value computed from wind driven wave slope variance. Finally, particulate backscatter was estimated from the depolarization ratio as the ratio of the column-integrated cross-polarized and co-polarized channels. Statistical results show that the derived particulate backscatter by the method based on CALIOP data agree reasonably well with chlorophyll-a concentration using MODIS data. It indicates a potential use of space-borne lidar to estimate global primary productivity and particulate carbon stock.

  1. Review of the state-of-the-art of exhaust particulate filter technology in internal combustion engines.

    PubMed

    Guan, Bin; Zhan, Reggie; Lin, He; Huang, Zhen

    2015-05-01

    The increasingly stringent emission regulations, such as US 2010, Tier 2 Bin 5 and beyond, off-road Tier 4 final, and Euro V/5 for particulate matter (PM) reduction applications, will mandate the use of the diesel particulate filters (DPFs) technology, which is proven to be the only way that can effectively control the particulate emissions. This paper covers a comprehensive overview of the state-of-the-art DPF technologies, including the advanced filter substrate materials, the novel catalyst formulations, the highly sophisticated regeneration control strategies, the DPF uncontrolled regenerations and their control methodologies, the DPF soot loading prediction, and the soot sensor for the PM on-board diagnostics (OBD) legislations. Furthermore, the progress of the highly optimized hybrid approaches, which involves the integration of diesel oxidation catalyst (DOC) + (DPF, NOx reduction catalyst), the selective catalytic reduction (SCR) catalyst coated on DPF, as well as DPF in the high-pressure exhaust gas recirculation (EGR) loop systems, is well discussed. Besides, the impacts of the quality of fuel and lubricant on the DPF performance and the maintenance and retrofit of DPF are fully elaborated. Meanwhile, the high efficiency gasoline particulate filter (GPF) technology is being required to effectively reduce the PM and particulate number (PN) emissions from the gasoline direct injection (GDI) engines to comply with the future increasingly stricter emissions regulations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Measurement of gas and aerosol agricultural emissions

    USDA-ARS?s Scientific Manuscript database

    Studies of air quality indicate that agricultural emissions may impact particulate mass concentrations through both primary and secondary processes. Agriculture impacts can include primary dust emission, on-facility combustion from vehicles or seasonal field burning, and gaseous emissions from waste...

  3. A COMPARATIVE REVIEW OF INORGANIC AEROSOL THERMODYNAMIC EQUILIBRIUM MODULES: SIMILARITIES, DIFFERENCES, AND THEIR LIKELY CAUSES

    EPA Science Inventory

    A comprehensive comparison of five inorganic aerosol thermodynamic equilibrium modules, MARS-A, SEQUILIB, SCAPE2, EQUISOLV II, and AIM2, was conducted for a variety of atmospheric concentrations of particulate matter (PM) constituents, relative humidities (RHs), and temperatures....

  4. MULTI-SITE FIELD EVALUATION OF CANDIDATE SAMPLERS FOR MEASURING COARSE-MODE PM

    EPA Science Inventory

    In response to expected changes to the National Ambient Air Quality Standards for particulate matter, comprehensive field studies were conducted to evaluate the performance of sampling methods for measuring coarse mode aerosols (i.e. PMc). Five separate PMc sampling approaches w...

  5. Characterization of particulate emissions from Australian open-cut coal mines: Toward improved emission estimates.

    PubMed

    Richardson, Claire; Rutherford, Shannon; Agranovski, Igor

    2018-06-01

    Given the significance of mining as a source of particulates, accurate characterization of emissions is important for the development of appropriate emission estimation techniques for use in modeling predictions and to inform regulatory decisions. The currently available emission estimation methods for Australian open-cut coal mines relate primarily to total suspended particulates and PM 10 (particulate matter with an aerodynamic diameter <10 μm), and limited data are available relating to the PM 2.5 (<2.5 μm) size fraction. To provide an initial analysis of the appropriateness of the currently available emission estimation techniques, this paper presents results of sampling completed at three open-cut coal mines in Australia. The monitoring data demonstrate that the particulate size fraction varies for different mining activities, and that the region in which the mine is located influences the characteristics of the particulates emitted to the atmosphere. The proportion of fine particulates in the sample increased with distance from the source, with the coarse fraction being a more significant proportion of total suspended particulates close to the source of emissions. In terms of particulate composition, the results demonstrate that the particulate emissions are predominantly sourced from naturally occurring geological material, and coal comprises less than 13% of the overall emissions. The size fractionation exhibited by the sampling data sets is similar to that adopted in current Australian emission estimation methods but differs from the size fractionation presented in the U.S. Environmental Protection Agency methodology. Development of region-specific emission estimation techniques for PM 10 and PM 2.5 from open-cut coal mines is necessary to allow accurate prediction of particulate emissions to inform regulatory decisions and for use in modeling predictions. Development of region-specific emission estimation techniques for PM 10 and PM 2.5 from open-cut coal mines is necessary to allow accurate prediction of particulate emissions to inform regulatory decisions and for use in modeling predictions. Comprehensive air quality monitoring was undertaken, and corresponding recommendations were provided.

  6. Using indoor air quality monitoring in 6 counties to change policy in North Carolina.

    PubMed

    Proescholdbell, Scott; Steiner, Julea; Goldstein, Adam O; Malek, Sally Herndon

    2009-07-01

    Indoor air quality monitoring has become a valuable tool for states wanting to assess levels of particulate matter before and after smoke-free policies are implemented. However, many states face barriers in passing comprehensive smoke-free legislation, making such study comparisons unlikely. We used indoor air monitoring data to educate decision makers about the value of comprehensive smoke-free laws in a state with strong historical ties to tobacco. We trained teams in 6 counties in North Carolina to monitor air quality in hospitality venues with 1 of 3 possible smoking policy designations: 1) smoke-free, 2) separate smoking and nonsmoking sections (mixed), or 3) smoking allowed in all areas. Teams monitored 152 venues for respirable suspended particles that were less than 2.5 microm in diameter and collected information on venue characteristics. The data were combined and analyzed by venue policy and by county. Our findings were presented to key decision makers, and we then collected information on media publicity about these analyses. Overall, smoke-free venues had the lowest particulate matter levels (15 microg/m3), well below established Environmental Protection Agency standards. Venues with mixed policies and venues that permitted smoking in all areas had particulate matter levels that are considered unhealthy by Environmental Protection Agency standards. The media coverage of our findings included newspaper, radio, and television reports. Findings were also discussed with local health directors, state legislators, and public health advocates. Study data have been used to quantify particulate matter levels, raise awareness about the dangers of secondhand smoke, build support for evidence-based policies, and promote smoke-free policies among policy makers. The next task is to turn this effort into meaningful policy change that will protect everyone from the harms of secondhand smoke.

  7. EXPLORING RELATIONSHIPS BETWEEN OUTDOOR AIR PARTICULATE-ASSOCIATED POLYCYCLIC AROMATIC HYDROCARBON AND PM2.5: A CASE STUDY OF BENZO(A)PYRENE IN CALIFORNIA METROPOLITAN REGIONS

    EPA Science Inventory

    Polycyclic aromatic hydrocarbons (PAHs) and particulate matter (PM) are co-pollutants emitted as by-products of combustion processes. Convincing evidence exists for PAHs as a primary toxic component of fine PM (PM2.5). Because PM2.5 is listed by the US EPA a...

  8. Combustion of PTFE: The Effects of Gravity and Pigmentation on Ultrafine Particle Generation

    NASA Technical Reports Server (NTRS)

    McKinnon, J. Thomas; Srivastava, Rajiv; Todd, Paul

    1997-01-01

    Ultrafine particles generated during polymer thermodegradation are a major health hazard, owing to their unique pathway of processing in the lung. This hazard in manned spacecraft is poorly understood, because the particulate products of polymer thermodegradation are generated under low gravity conditions. Particulate generated from the degradation of PolyTetraFluoroEthylene (PTFE), insulation coating for 20 AWG copper wire (representative of spacecraft application) under intense ohmic heating were studied in terrestrial gravity and microgravity. Microgravity tests were done in a 1.2-second drop tower at the Colorado School of Mines (CSM). Thermophoretic sampling was used for particulate collection. Transmission Electron Microscopy (TEM) and Scanning Transmission Electron Microscopy (STEM) were used to examine the smoke particulates. Image software was used to calculate particle size distribution. In addition to gravity, the color of PTFE insulation has an overwhelming effect on size, shape and morphology of the particulate. Nanometer-sized primary particles were found in all cases, and aggregation and size distribution was dependent on both color and gravity; higher aggregation occurred in low gravity. Particulates from white, black, red and yellow colored PTFE insulations were studied. Elemental analysis of the particulates shows the presence of inorganic pigments.

  9. Untargeted Identification of Wood Type-Specific Markers in Particulate Matter from Wood Combustion.

    PubMed

    Weggler, Benedikt A; Ly-Verdu, Saray; Jennerwein, Maximilian; Sippula, Olli; Reda, Ahmed A; Orasche, Jürgen; Gröger, Thomas; Jokiniemi, Jorma; Zimmermann, Ralf

    2016-09-20

    Residential wood combustion emissions are one of the major global sources of particulate and gaseous organic pollutants. However, the detailed chemical compositions of these emissions are poorly characterized due to their highly complex molecular compositions, nonideal combustion conditions, and sample preparation steps. In this study, the particulate organic emissions from a masonry heater using three types of wood logs, namely, beech, birch, and spruce, were chemically characterized using thermal desorption in situ derivatization coupled to a GCxGC-ToF/MS system. Untargeted data analyses were performed using the comprehensive measurements. Univariate and multivariate chemometric tools, such as analysis of variance (ANOVA), principal component analysis (PCA), and ANOVA simultaneous component analysis (ASCA), were used to reduce the data to highly significant and wood type-specific features. This study reveals substances not previously considered in the literature as meaningful markers for differentiation among wood types.

  10. Does Particulate Air Pollution Contribute to Infant Death? A Systematic Review

    PubMed Central

    Glinianaia, Svetlana V.; Rankin, Judith; Bell, Ruth; Pless-Mulloli, Tanja; Howel, Denise

    2004-01-01

    There is now substantial evidence that both short- and long-term increases in ambient air pollution are associated with increased mortality and morbidity in adults and children. Children’s health is particularly vulnerable to environmental pollution, and infant mortality is still a major contributor to childhood mortality. In this systematic review we summarize and evaluate the current level of epidemiologic evidence of an association between particulate air pollution and infant mortality. We identified relevant publications using database searches with a comprehensive list of search terms and other established search methods. We included articles in the review according to specified inclusion criteria. Fifteen studies met our inclusion criteria. Evidence of an association between particulate air pollution and infant mortality in general was inconsistent, being reported from locations with largely comparable pollution levels. There was some evidence that the strength of association with particulate matter differed by subgroups of infant mortality. It was more consistent for post-neonatal mortality due to respiratory causes and sudden infant death syndrome. Differential findings for various mortality subgroups within studies suggest a stronger association of particulate air pollution with some causes of infant death. Research is needed to confirm and clarify these links, using the most appropriate methodologies for exposure assessment and control of confounders. PMID:15471726

  11. Spatial distributions of polyunsaturated aldehydes and their biogeochemical implications in the Pearl River Estuary and the adjacent northern South China Sea

    NASA Astrophysics Data System (ADS)

    Wu, Zhengchao; Li, Qian P.

    2016-09-01

    This study reports the first comprehensive exploration of the spatial patterns of dissolved and particulate polyunsaturated aldehydes (PUAs), their physical and biological controlling factors, and their potential biogeochemical influences in the Pearl River Estuary (PRE) of the northern South China Sea (NSCS). High levels of total particulate PUAs (0-41 nM) and dissolved PUAs (0.10-0.37 nM) were observed with substantial spatial variation during an intense summer phytoplankton bloom outside the PRE mouth. We found the particulate PUAs strongly correlated with temperature within the high chlorophyll bloom, while showing a generally positive correlation with chlorophyll-a for the entire region. Additionally, the Si/N ratio significantly correlated with the particulate PUAs along the estuary suggesting the important role of silica on PUA production in this region. The dissolved PUAs counterparts exhibited a positive correlation with chlorophyll-a within the high chlorophyll bloom, but a negatively one with temperature outside, reflecting the essential bio-physical coupling effects on the dissolved PUAs distributions in the ocean. Biogeochemical implications of PUAs on the coastal ecosystem include not only the deleterious restriction of high PUAs-producing diatom bloom on copepod population, but also the profound influence of particulate PUAs on the microbial cycling of organic carbon in the NSCS.

  12. Magnetic resonance studies of dissolving particulate solids.

    PubMed

    Johns, M L; Gladden, L F

    2003-01-01

    Magnetic resonance methods have been used to elucidate the internal pore structure of particulate solids, in particular detergent tablets. Such information is essential to a comprehensive understanding of the dissolution characteristics of these materials and how this property is related to processing conditions during tablet formation. In particular 3-D images of porosity are produced and 2-D self-diffusion maps are acquired as a function of observation time, which enables pore size to be quantified as a function of position via the extracted surface-to-volume ratio of the pore space. These properties are determined as a function of processing parameters, in particular the compression force used in tablet formation.

  13. Fundamental reform of payment for adult primary care: comprehensive payment for comprehensive care.

    PubMed

    Goroll, Allan H; Berenson, Robert A; Schoenbaum, Stephen C; Gardner, Laurence B

    2007-03-01

    Primary care is essential to the effective and efficient functioning of health care delivery systems, yet there is an impending crisis in the field due in part to a dysfunctional payment system. We present a fundamentally new model of payment for primary care, replacing encounter-based imbursement with comprehensive payment for comprehensive care. Unlike former iterations of primary care capitation (which simply bundled inadequate fee-for-service payments), our comprehensive payment model represents new investment in adult primary care, with substantial increases in payment over current levels. The comprehensive payment is directed to practices to include support for the modern systems and teams essential to the delivery of comprehensive, coordinated care. Income to primary physicians is increased commensurate with the high level of responsibility expected. To ensure optimal allocation of resources and the rewarding of desired outcomes, the comprehensive payment is needs/risk-adjusted and performance-based. Our model establishes a new social contract with the primary care community, substantially increasing payment in return for achieving important societal health system goals, including improved accessibility, quality, safety, and efficiency. Attainment of these goals should help offset and justify the costs of the investment. Field tests of this and other new models of payment for primary care are urgently needed.

  14. Fundamental Reform of Payment for Adult Primary Care: Comprehensive Payment for Comprehensive Care

    PubMed Central

    Berenson, Robert A.; Schoenbaum, Stephen C.; Gardner, Laurence B.

    2007-01-01

    Primary care is essential to the effective and efficient functioning of health care delivery systems, yet there is an impending crisis in the field due in part to a dysfunctional payment system. We present a fundamentally new model of payment for primary care, replacing encounter-based imbursement with comprehensive payment for comprehensive care. Unlike former iterations of primary care capitation (which simply bundled inadequate fee-for-service payments), our comprehensive payment model represents new investment in adult primary care, with substantial increases in payment over current levels. The comprehensive payment is directed to practices to include support for the modern systems and teams essential to the delivery of comprehensive, coordinated care. Income to primary physicians is increased commensurate with the high level of responsibility expected. To ensure optimal allocation of resources and the rewarding of desired outcomes, the comprehensive payment is needs/risk-adjusted and performance-based. Our model establishes a new social contract with the primary care community, substantially increasing payment in return for achieving important societal health system goals, including improved accessibility, quality, safety, and efficiency. Attainment of these goals should help offset and justify the costs of the investment. Field tests of this and other new models of payment for primary care are urgently needed. PMID:17356977

  15. The Effects of Global Change upon United States Air Quality

    EPA Science Inventory

    To understand more fully the effects of global changes on ambient concentrations of ozone and particulate matter with aerodynamic diameter smaller than 2.5 μm (PM2.5) in the US, we conducted a comprehensive modeling effort to evaluate explicitly the effects of change...

  16. ALTERED GENE EXPRESSION PROFILES OF RAT LUNG IN RESPONSE TO AN EMISSION PARTICULATE AND ITS METAL CONSTITUENTS

    EPA Science Inventory

    Comprehensive and systematic approaches are needed to understand the molecular basis for the proposed adverse health effects of PM exposure reported in epidemiological studies. Due to the complex nature of the pollutant and the altered physiological conditions in the predisposed...

  17. Reducing nutrient losses in runoff from furrow irrigation

    USDA-ARS?s Scientific Manuscript database

    Few studies have comprehensively examined nutrient losses in runoff from furrow-irrigated fields, but the rising cost of fertilizer and finite nature of the resource encourages further research. A 2-yr experiment measured runoff losses of sediment, particulate P and N, and dissolved NO3-N, NH4-N, K...

  18. Environmental Compliance Assessment System (ECAS). Kentucky Supplement (Revised)

    DTIC Science & Technology

    1994-02-01

    vehicles or vehicle bodies. "* FGD - Flue Gas Desulfurization . "* Field-Erected - assembled from components at a final site of operation. "* Flare - a...34* Spare Flue Gas Desulfurization System Module - a separate system of sulfur dioxide emission con- trol equipment capable of treating an amount of flue ...Carryover - particulate matter which is passed from the primary chamber of an incinerator into the flue gas stream. " Particulate Matter Emissions

  19. A Small Angle Scattering Sensor System for the Characterization of Combustion Generated Particulate

    NASA Technical Reports Server (NTRS)

    Feikema, Douglas A.; Kim, W.; Sivathanu, Yudaya

    2007-01-01

    One of the critical issues for the US space program is fire safety of the space station and future launch vehicles. A detailed understanding of the scattering signatures of particulate is essential for the development of a false alarm free fire detection system. This paper describes advanced optical instrumentation developed and applied for fire detection. The system is being designed to determine four important physical properties of disperse fractal aggregates and particulates including size distribution, number density, refractive indices, and fractal dimension. Combustion generated particulate are the primary detection target; however, in order to discriminate from other particulate, non-combustion generated particles should also be characterized. The angular scattering signature is measured and analyzed using two photon optical laser scattering. The Rayleigh-Debye-Gans (R-D-G) scattering theory for disperse fractal aggregates is utilized. The system consists of a pulsed laser module, detection module and data acquisition system and software to analyze the signals. The theory and applications are described.

  20. The cytotoxicity and genotoxicity of soluble and particulate cobalt in human lung fibroblast cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Smith, Leah J.; Holmes, Amie L.; Maine Center for Environmental Toxicology and Health, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300

    Cobalt exposure is increasing as cobalt demand rises worldwide due to its use in enhancing rechargeable battery efficiency, super-alloys, and magnetic products. Cobalt is considered a possible human carcinogen with the lung being a primary target. However, few studies have considered cobalt-induced toxicity in human lung cells. Therefore, in this study, we sought to determine the cytotoxicity and genotoxicity of particulate and soluble cobalt in human lung cells. Cobalt oxide and cobalt chloride were used as representative particulate and soluble cobalt compounds, respectively. Exposure to both particulate and soluble cobalt induced a concentration-dependent increase in cytotoxicity, genotoxicity, and intracellular cobaltmore » ion levels. Based on intracellular cobalt ion levels, we found that soluble cobalt was more cytotoxic than particulate cobalt while particulate and soluble cobalt induced similar levels of genotoxicity. However, soluble cobalt induced cell cycle arrest indicated by the lack of metaphases at much lower intracellular cobalt concentrations compared to cobalt oxide. Accordingly, we investigated the role of particle internalization in cobalt oxide-induced toxicity and found that particle-cell contact was necessary to induce cytotoxicity and genotoxicity after cobalt exposure. These data indicate that cobalt compounds are cytotoxic and genotoxic to human lung fibroblasts, and solubility plays a key role in cobalt-induced lung toxicity. - Highlights: • Particulate and soluble cobalt are cytotoxic and genotoxic to human lung cells. • Soluble cobalt induces more cytotoxicity compared to particulate cobalt. • Soluble and particulate cobalt induce similar levels of genotoxicity. • Particle-cell contact is required for particulate cobalt-induced toxicity.« less

  1. Can neap-spring tidal cycles modulate biogeochemical fluxes in the abyssal near-seafloor water column?

    NASA Astrophysics Data System (ADS)

    Turnewitsch, Robert; Dale, Andrew; Lahajnar, Niko; Lampitt, Richard S.; Sakamoto, Kei

    2017-05-01

    Before particulate matter that settles as 'primary flux' from the interior ocean is deposited into deep-sea sediments it has to traverse the benthic boundary layer (BBL) that is likely to cover almost all parts of the seafloor in the deep seas. Fluid dynamics in the BBL differ vastly from fluid dynamics in the overlying water column and, consequently, have the potential to lead to quantitative and compositional changes between primary and depositional fluxes. Despite this potential and the likely global relevance very little is known about mechanistic and quantitative aspects of the controlling processes. Here, results are presented for a sediment-trap time-series study that was conducted on the Porcupine Abyssal Plain in the abyssal Northeast Atlantic, with traps deployed at 2, 40 and 569 m above bottom (mab). The two bottommost traps were situated within the BBL-affected part of the water column. The time series captured 3 neap and 4 spring tides and the arrival of fresh settling material originating from a surface-ocean bloom. In the trap-collected material, total particulate matter (TPM), particulate inorganic carbon (PIC), biogenic silica (BSi), particulate organic carbon (POC), particulate nitrogen (PN), total hydrolysable amino acids (AA), hexosamines (HA) and lithogenic material (LM) were determined. The biogeochemical results are presented within the context of time series of measured currents (at 15 mab) and turbidity (at 1 mab). The main outcome is evidence for an effect of neap/spring tidal oscillations on particulate-matter dynamics in BBL-affected waters in the deep sea. Based on the frequency-decomposed current measurements and numerical modelling of BBL fluid dynamics, it is concluded that the neap/spring tidal oscillations of particulate-matter dynamics are less likely due to temporally varying total free-stream current speeds and more likely due to temporally and vertically varying turbulence intensities that result from the temporally varying interplay of different rotational flow components (residual, tidal, near-inertial) within the BBL. Using information from previously published empirical and theoretical relations between fluid and biogeochemical dynamics at the scale of individual particle aggregates, a conceptual and semi-quantitative picture of a mechanism was derived that explains how the neap/spring fluid-dynamic oscillations may translate through particle dynamics into neap/spring oscillations of biogeochemical aggregate decomposition (microbially driven organic-matter breakdown, biomineral dissolution). It is predicted that, during transitions from neap into spring tides, increased aggregation in near-seafloor waters and/or reduced deposition of aggregates at the seafloor coincides with reduced biogeochemical particulate-matter decomposition in near-seafloor waters. By contrast, during transitions from spring into neap tides, enhanced biogeochemical particulate-matter decomposition in near-seafloor waters is predicted to coincide with increased deposition of particulate matter at the seafloor. This study suggests that, in addition to current speed, the specifics and subtleties of the interplay of different rotational flow components can be an important control on how the primary flux from the interior ocean is translated into the depositional flux, with potential implications for sedimentary carbon deposition, benthic food supply and possibly even the sedimentary records of environmental change.

  2. The Effect of the 4MAT Learning Model on the Achievement and Motivation of 7th Grade Students on the Subject of Particulate Nature of Matter and an Examination of Student Opinions on the Model

    ERIC Educational Resources Information Center

    Aktas, Idris; Bilgin, Ibrahim

    2015-01-01

    Background: Many researchers agree that students, especially primary students, have learning difficulties on the "Particulate Nature of Matter" unit. One reason for this difficulty is not considering individual differences for teaching science. In 4MAT model learning, environment is arranged according to individual differences. Purpose:…

  3. High particulate iron(II) content in glacially sourced dusts enhances productivity of a model diatom

    PubMed Central

    Shoenfelt, Elizabeth M.; Sun, Jing; Winckler, Gisela; Kaplan, Michael R.; Borunda, Alejandra L.; Farrell, Kayla R.; Moreno, Patricio I.; Gaiero, Diego M.; Recasens, Cristina; Sambrotto, Raymond N.; Bostick, Benjamin C.

    2017-01-01

    Little is known about the bioavailability of iron (Fe) in natural dusts and the impact of dust mineralogy on Fe utilization by photosynthetic organisms. Variation in the supply of bioavailable Fe to the ocean has the potential to influence the global carbon cycle by modulating primary production in the Southern Ocean. Much of the dust deposited across the Southern Ocean is sourced from South America, particularly Patagonia, where the waxing and waning of past and present glaciers generate fresh glaciogenic material that contrasts with aged and chemically weathered nonglaciogenic sediments. We show that these two potential sources of modern-day dust are mineralogically distinct, where glaciogenic dust sources contain mostly Fe(II)-rich primary silicate minerals, and nearby nonglaciogenic dust sources contain mostly Fe(III)-rich oxyhydroxide and Fe(III) silicate weathering products. In laboratory culture experiments, Phaeodactylum tricornutum, a well-studied coastal model diatom, grows more rapidly, and with higher photosynthetic efficiency, with input of glaciogenic particulates compared to that of nonglaciogenic particulates due to these differences in Fe mineralogy. Monod nutrient accessibility models fit to our data suggest that particulate Fe(II) content, rather than abiotic solubility, controls the Fe bioavailability in our Fe fertilization experiments. Thus, it is possible for this diatom to access particulate Fe in dusts by another mechanism besides uptake of unchelated Fe (Fe′) dissolved from particles into the bulk solution. If this capability is widespread in the Southern Ocean, then dusts deposited to the Southern Ocean in cold glacial periods are likely more bioavailable than those deposited in warm interglacial periods. PMID:28691098

  4. Effect of atmospheric ageing on volatility and ROS of biodiesel exhaust nano-particles

    NASA Astrophysics Data System (ADS)

    Pourkhesalian, A. M.; Stevanovic, S.; Rahman, M. M.; Faghihi, E. M.; Bottle, S. E.; Masri, A. R.; Brown, R. J.; Ristovski, Z. D.

    2015-03-01

    In the prospect of limited energy resources and climate change, effects of alternative biofuels on primary emissions are being extensively studied. Our two recent studies have shown that biodiesel fuel composition has a~significant impact on primary particulate matter emissions. It was also shown that particulate matter caused by biodiesels was substantially different from the emissions due to petroleum diesel. Emissions appeared to have higher oxidative potential with the increase in oxygen content and decrease of carbon chain length and unsaturation levels of fuel molecules. Overall, both studies concluded that chemical composition of biodiesel is more important than its physical properties in controlling exhaust particle emissions. This suggests that the atmospheric ageing processes, including secondary organic aerosol formation, of emissions from different fuels will be different as well. In this study, measurements were conducted on a modern common-rail diesel engine. To get more information on realistic properties of tested biodiesel particulate matter once they are released into the atmosphere, particulate matter was exposed to atmospheric oxidants, ozone and ultra-violet light; and the change in their properties was monitored for different biodiesel blends. Upon the exposure to oxidative agents, the chemical composition of the exhaust changes. It triggers the cascade of photochemical reactions resulting in the partitioning of semi-volatile compounds between the gas and particulate phase. In most of the cases, aging lead to the increase in volatility and oxidative potential, and the increment of change was mainly dependent on the chemical composition of fuels as the leading cause for the amount and the type of semi-volatile compounds present in the exhaust.

  5. Comprehensive analysis of airborne contaminants from recent Spacelab missions

    NASA Technical Reports Server (NTRS)

    Matney, M. L.; Boyd, J. F.; Covington, P. A.; Leano, H. J.; Pierson, D. L.; Limero, T. F.; James, J. T.

    1993-01-01

    The Shuttle experiences unique air contamination problems because of microgravity and the closed environment. Contaminant build-up in the closed atmosphere and the lack of a gravitational settling mechanism have produced some concern in previous missions about the amount of solid and volatile airborne contaminants in the Orbiter and Spacelab. Degradation of air quality in the Orbiter/Spacelab environment, through processes such as chemical contamination, high solid-particulate levels, and high microbial levels, may affect crew performance and health. A comprehensive assessment of the Shuttle air quality was undertaken during STS-40 and STS-42 missions, in which a variety of air sampling and monitoring techniques were employed to determine the contaminant load by characterizing and quantitating airborne contaminants. Data were collected on the airborne concentrations of volatile organic compounds, microorganisms, and particulate matter collected on Orbiter/Spacelab air filters. The results showed that STS-40/42 Orbiter/Spacelab air was toxicologically safe to breathe, except during STS-40 when the Orbiter Refrigerator/Freezer unit was releasing noxious gases in the middeck. On STS-40, the levels of airborne bacteria appeared to increase as the mission progressed; however, this trend was not observed for the STS-42 mission. Particulate matter in the Orbiter/Spacelab air filters was chemically analyzed in order to determine the source of particles. Only small amounts of rat hair and food bar (STS-40) and traces of soiless medium (STS-42) were detected in the Spacelab air filters, indicating that containment for Spacelab experiments was effective.

  6. Particulate matter emissions from biochar-amended soils as a potential tradeoff to the negative emission potential

    USDA-ARS?s Scientific Manuscript database

    Novel carbon sequestration strategies such as large-scale land application of biochar may provide sustainable pathways to increase the terrestrial storage of carbon. Biochar has a long residence time in the soil and hence comprehensive studies are urgently needed to quantify the environmental impact...

  7. CHARACTERIZATION OF PARTICULATE MATTER AND CO-POLLUTANTS EXPOSURES FOR COMPROMISED AND HEALTHY ELDERLY ADULTS IN SEATTLE, WA, 1999-2001

    EPA Science Inventory

    This paper presents results from a 2-year comprehensive exposure assessment study that examined the PM exposures and health effects in individuals with and without chronic obstructive pulmonary disease (COPD) and cardiovascular (CV) diseases. Forty-six COPD, 21 CV, and 42 heal...

  8. Environmental assessment of NH3 injection for an industrial package boiler. Volume 2. Data supplement. Final report, January 1983-January 1984

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Castaldini, C.; DeRosier, R.; Waterland, L.R.

    1986-02-01

    The report discusses emission results from comprehensive flue-gas sampling of a gas- and oil-fired industrial boiler equipped with Exxon's Thermal DeNOx Ammonia Injection Process for NOx reduction. Comprehensive emission measurements included continuous monitoring of flue gas emissions; source assessment sampling system (SASS) tests; EPA Method 5/17 for solid and condensible particulate emissions and ammonia emissions; controlled condensation system for SO2 and SO3; and N2O emission sampling. Ammonia injection at a NH3/NO molar ratio of 2.52 gave a NOx reduction of 41% from an uncontrolled level of 234 ppm to a controlled level of 137 ppm. NH3 emissions increased from 11more » ppm for the baseline to an average of 430 ppm for ammonia injection. Nitrous oxide, N2O, was reduced 68% from a 50 ppm baseline level to a 17 ppm controlled level. Total particulate emissions increased by an order of magnitude from a baseline of 17.7 ng/J to a controlled level of 182 ng/J.« less

  9. The ice nucleation temperature determines the primary drying rate of lyophilization for samples frozen on a temperature-controlled shelf.

    PubMed

    Searles, J A; Carpenter, J F; Randolph, T W

    2001-07-01

    The objective of this study was to determine the influence of ice nucleation temperature on the primary drying rate during lyophilization for samples in vials that were frozen on a lyophilizer shelf. Aqueous solutions of 10% (w/v) hydroxyethyl starch were frozen in vials with externally mounted thermocouples and then partially lyophilized to determine the primary drying rate. Low- and high-particulate-containing samples, ice-nucleating additives silver iodide and Pseudomonas syringae, and other methods were used to obtain a wide range of nucleation temperatures. In cases where the supercooling exceeded 5 degrees C, freezing took place in the following three steps: (1) primary nucleation, (2) secondary nucleation encompassing the entire liquid volume, and (3) final solidification. The primary drying rate was dependent on the ice nucleation temperature, which is stochastic in nature but is affected by particulate content and the presence of ice nucleators. Sample cooling rates of 0.05 to 1 degrees C/min had no effect on nucleation temperatures and drying rate. We found that the ice nucleation temperature is the primary determinant of the primary drying rate. However, the nucleation temperature is not under direct control, and its stochastic nature and sensitivity to difficult-to-control parameters result in drying rate heterogeneity. Nucleation temperature heterogeneity may also result in variation in other morphology-related parameters such as surface area and secondary drying rate. Overall, these results document that factors such as particulate content and vial condition, which influence ice nucleation temperature, must be carefully controlled to avoid, for example, lot-to-lot variability during cGMP production. In addition, if these factors are not controlled and/or are inadvertently changed during process development and scaleup, a lyophilization cycle that was successful on the research scale may fail during large-scale production.

  10. COMPARISON OF PM-INDUCED GENE EXPRESSION PROFILES BETWEEN BRONCHIAL EPITHELIAL CELLS AND NASAL EPITHELIAL CELLS IN HUMAN

    EPA Science Inventory

    Epidemiologic studies have linked exposures to particulate matter (PM) and increased pulmonary mortality and morbidity. Bronchial epithelial cells (BEC) are the primary target of PM. PM exposure induces a wide array of biological responses in BEC. Primary human BEC, however, need...

  11. 40 CFR 62.3100 - Identification of plan-negative declaration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Idaho Fluoride Emissions from Existing Primary Aluminum Plants § 62.3100 Identification of plan—negative... that there are no existing primary aluminum plants in the State subject to part 60, subpart B of this chapter. [47 FR 47250, Oct. 25, 1982] Metals, Acid Gases, Organic Compounds, Particulates and Nitrogen...

  12. 40 CFR 62.3100 - Identification of plan-negative declaration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Idaho Fluoride Emissions from Existing Primary Aluminum Plants § 62.3100 Identification of plan—negative... that there are no existing primary aluminum plants in the State subject to part 60, subpart B of this chapter. [47 FR 47250, Oct. 25, 1982] Metals, Acid Gases, Organic Compounds, Particulates and Nitrogen...

  13. 40 CFR 62.3100 - Identification of plan-negative declaration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Idaho Fluoride Emissions from Existing Primary Aluminum Plants § 62.3100 Identification of plan—negative... that there are no existing primary aluminum plants in the State subject to part 60, subpart B of this chapter. [47 FR 47250, Oct. 25, 1982] Metals, Acid Gases, Organic Compounds, Particulates and Nitrogen...

  14. 40 CFR 62.3100 - Identification of plan-negative declaration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Idaho Fluoride Emissions from Existing Primary Aluminum Plants § 62.3100 Identification of plan—negative... that there are no existing primary aluminum plants in the State subject to part 60, subpart B of this chapter. [47 FR 47250, Oct. 25, 1982] Metals, Acid Gases, Organic Compounds, Particulates and Nitrogen...

  15. Understanding Particulate Matter Dynamics in the San Joaquin Valley during DISCOVER-AQ, 2013

    NASA Astrophysics Data System (ADS)

    Prabhakar, G.; Zhang, X.; Kim, H.; Parworth, C.; Pusede, S. E.; Wooldridge, P. J.; Cohen, R. C.; Zhang, Q.; Cappa, C. D.

    2015-12-01

    Air quality in the California San Joaquin Valley (SJV) during winter continues to be the worst in the state, failing EPA's 24-hour standard for particulate matter. Despite our improved understanding of the sources of particulate matter (PM) in the valley, air-quality models are unable to predict PM concentrations accurately. We aim to characterize periods of high particulate matter concentrations in the San Joaquin Valley based on ground and airborne measurements of aerosols and gaseous pollutants, during the DISCOVER-AQ campaign, 2013. A highly instrumented aircraft flew across the SJV making three transects in a repeatable pattern, with vertical spirals over select locations. The aircraft measurements were complemented by ground measurements at these locations, with extensive chemically-speciated measurements at a ground "supersite" at Fresno. Hence, the campaign provided a comprehensive three-dimensional view of the particulate and gaseous pollutants around the valley. The vertical profiles over the different sites indicate significant variability in the concentrations and vertical distribution of PM around the valley, which are most likely driven by differences in the combined effects of emissions, chemistry and boundary layer dynamics at each site. The observations suggest that nighttime PM is dominated by surface emissions of PM from residential fuel combustion, while early morning PM is strongly influenced by mixing of low-level, above-surface, nitrate-rich layers formed from dark chemistry overnight to the surface.

  16. Gaseous and particulate emissions from a DC arc melter.

    PubMed

    Overcamp, Thomas J; Speer, Matthew P; Griner, Stewart J; Cash, Douglas M

    2003-01-01

    Tests treating soils contaminated with metal compounds and radionuclide surrogates were conducted in a DC arc melter. The soil melted, and glassy or ceramic waste forms with a separate metal phase were produced. Tests were run in the melter plenum with either air or N2 purge gases. In addition to nitrogen, the primary emissions of gases were CO2, CO, oxygen, methane, and oxides of nitrogen (NO(x)). Although the gas flow through the melter was low, the particulate concentrations ranged from 32 to 145 g/m3. Cerium, a nonradioactive surrogate for plutonium and uranium, was not enriched in the particulate matter (PM). The PM was enriched in cesium and highly enriched in lead.

  17. Primary productivity (PP) in the North Pacific Subtropical Gyre: Understanding drivers of variability via 14C-tracer incubations and PP diagnosed via the diurnal cycle of particulate carbon.

    NASA Astrophysics Data System (ADS)

    White, A. E.; Letelier, R. M.

    2016-02-01

    The rate of primary production (PP) in the ocean is a fundamental step in the ocean's food web and biological carbon pump. For more than 50 years oceanographers have relied primarily on estimates of PP based on in vitro measurements of 14CO2 uptake rates. Yet, it is difficult to reconcile PP rates measured in vitro with in situ rates. Here we present diurnal cycles of optically-derived particulate organic carbon (POC) and particle size distributions measured over a series of cruises in the North Pacific relative to traditional 14C-based PP measurements. We have calculated net PP from the daytime increase in optically-derived particulate organic carbon (POC) and the sum of respiration, grazing and sinking from the nighttime POM decrease. Comparison of optically derived NPP to parallel 12-hr 14C incubations are highly significant. The variability in productivity measurements over daily to seasonal to annual time-scales are discussed relative to predominant chemical, physical and climactic forcing.

  18. A New Priority: Comprehension Intervention in the Primary Grades

    ERIC Educational Resources Information Center

    Dougherty Stahl, Katherine A.

    2016-01-01

    Teachers in primary classrooms who are emphasizing high-level comprehension of complex texts are seeing young children hit comprehension thresholds that were previously only visible among older readers. However, most primary level reading interventions focus on word recognition skills or reading increasingly difficult leveled texts. This article…

  19. Characterization of exhaust emissions from diesel-powered passenger cars with particular reference to unregulated components

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lies, K.H.; Postulka, A.; Gring, H.

    Besides regulated components VW's research program in the field of characterization of diesel emissions comprises a detailed analysis of the particulates and a comprehensive study of a number of unregulated gaseous compounds. The following chemical compounds and classes of compounds are measured: particulates, traces of metals, major elements, sulfates, sulfur dioxide, hydrogen sulfide, hydrogen cyanide, aldehydes, ammonia, phenols, individual hydrocarbons, and odor (DOAS). The test fleet of this investigation included a number of VW and Audi cars equipped with 4-, and 5-cylinder diesel engines (naturally aspirated and turbocharged). All measurements were performed on a chassis dynamometer in accordance with themore » specification of the known US-test-procedures: Federal Test Procedure, Sulfate Emission Test, Fuel Economy Test. For sampling , in principle, the dilution tunnel technique was used combined with an automatically working collection system. This micro-processor controlled system involves 13 individual sample lines, 8 for gaseous and 5 for particulate components.« less

  20. 40 CFR 60.142 - Standard for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Emissions from Basic Oxygen Process Furnaces for Which Construction is Commenced After June 11, 1973 § 60... primary oxygen blow. (ii) Exit from a control device not used solely for the collection of secondary.../dscm (0.030 gr/dscf), as measured for the primary oxygen blow. (ii) Exit from a control device not used...

  1. 40 CFR 60.142 - Standard for particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Emissions from Basic Oxygen Process Furnaces for Which Construction is Commenced After June 11, 1973 § 60... primary oxygen blow. (ii) Exit from a control device not used solely for the collection of secondary.../dscm (0.030 gr/dscf), as measured for the primary oxygen blow. (ii) Exit from a control device not used...

  2. 40 CFR 60.142 - Standard for particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Emissions from Basic Oxygen Process Furnaces for Which Construction is Commenced After June 11, 1973 § 60... primary oxygen blow. (ii) Exit from a control device not used solely for the collection of secondary.../dscm (0.030 gr/dscf), as measured for the primary oxygen blow. (ii) Exit from a control device not used...

  3. 40 CFR 60.142 - Standard for particulate matter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Emissions from Basic Oxygen Process Furnaces for Which Construction is Commenced After June 11, 1973 § 60... primary oxygen blow. (ii) Exit from a control device not used solely for the collection of secondary.../dscm (0.030 gr/dscf), as measured for the primary oxygen blow. (ii) Exit from a control device not used...

  4. 40 CFR 60.142 - Standard for particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Emissions from Basic Oxygen Process Furnaces for Which Construction is Commenced After June 11, 1973 § 60... primary oxygen blow. (ii) Exit from a control device not used solely for the collection of secondary.../dscm (0.030 gr/dscf), as measured for the primary oxygen blow. (ii) Exit from a control device not used...

  5. Impact evaluation of a health promotion-focused organisational development strategy on a health service's capacity to deliver comprehensive primary health care.

    PubMed

    Costello, Michelle; Taylor, Jane; O'Hara, Lily

    2015-01-01

    A comprehensive primary health care approach is required to address complex health issues and reduce inequities. However, there has been limited uptake of this approach by health services nationally or internationally. Reorienting health services towards becoming more health promoting provides a mechanism to support the delivery of comprehensive primary health care. The aim of this study was to determine the impact of a health promotion-focused organisational development strategy on the capacity of a primary health care service to deliver comprehensive primary health care. A questionnaire and semistructured individual interviews were used to collect quantitative and qualitative impact evaluation data, respectively, from 13 health service staff across three time points with regard to 37 indicators of organisational capacity. There were significant increases in mean scores for 31 indicators, with effect sizes ranging from moderate to nearly perfect. A range of key enablers and barriers to support the delivery of comprehensive primary health care was identified. In conclusion, an organisational development strategy to reorient health services towards becoming more health promoting may increase the capacity to deliver comprehensive primary health care.

  6. Determination of the Particle Content of Flowing Gases. An Annotated Bibliography.

    ERIC Educational Resources Information Center

    Rouillard, E. A.

    The bibliography is intended to provide a comprehensive source of information on the sampling and monitoring of particulates in flowing gas streams. It also includes methods of measurement which were initially applied to the measurement of dust in still atmospheres, but which either have been or may be used in the future for measurements in…

  7. Effect of atmospheric aging on volatility and reactive oxygen species of biodiesel exhaust nano-particles

    NASA Astrophysics Data System (ADS)

    Pourkhesalian, A. M.; Stevanovic, S.; Rahman, M. M.; Faghihi, E. M.; Bottle, S. E.; Masri, A. R.; Brown, R. J.; Ristovski, Z. D.

    2015-08-01

    In the prospect of limited energy resources and climate change, effects of alternative biofuels on primary emissions are being extensively studied. Our two recent studies have shown that biodiesel fuel composition has a significant impact on primary particulate matter emissions. It was also shown that particulate matter caused by biodiesels was substantially different from the emissions due to petroleum diesel. Emissions appeared to have higher oxidative potential with the increase in oxygen content and decrease of carbon chain length and unsaturation levels of fuel molecules. Overall, both studies concluded that chemical composition of biodiesel is more important than its physical properties in controlling exhaust particle emissions. This suggests that the atmospheric aging processes, including secondary organic aerosol formation, of emissions from different fuels will be different as well. In this study, measurements were conducted on a modern common-rail diesel engine. To get more information on realistic properties of tested biodiesel particulate matter once they are released into the atmosphere, particulate matter was exposed to atmospheric oxidants, ozone and ultra-violet light; and the change in their properties was monitored for different biodiesel blends. Upon the exposure to oxidative agents, the chemical composition of the exhaust changes. It triggers the cascade of photochemical reactions resulting in the partitioning of semi-volatile compounds between the gas and particulate phase. In most of the cases, aging lead to the increase in volatility and oxidative potential, and the increment of change was mainly dependent on the chemical composition of fuels as the leading cause for the amount and the type of semi-volatile compounds present in the exhaust.

  8. Source apportionment studies on particulate matter in Beijing/China

    NASA Astrophysics Data System (ADS)

    Suppan, P.; Shen, R.; Shao, L.; Schrader, S.; Schäfer, K.; Norra, S.; Vogel, B.; Cen, K.; Wang, Y.

    2013-05-01

    More than 15 million people in the greater area of Beijing are still suffering from severe air pollution levels caused by sources within the city itself but also from external impacts like severe dust storms and long range advection from the southern and central part of China. Within this context particulate matter (PM) is the major air pollutant in the greater area of Beijing (Garland et al., 2009). PM did not serve only as lead substance for air quality levels and therefore for adverse health impact effects but also for a strong influence on the climate system by changing e.g. the radiative balance. Investigations on emission reductions during the Olympic Summer Games in 2008 have caused a strong reduction on coarser particles (PM10) but not on smaller particles (PM2.5). In order to discriminate the composition of the particulate matter levels, the different behavior of coarser and smaller particles investigations on source attribution, particle characteristics and external impacts on the PM levels of the city of Beijing by measurements and modeling are performed: a) Examples of long term measurements of PM2.5 filter sampling in 2010/2011 with the objectives of detailed chemical (source attribution, carbon fraction, organic speciation and inorganic composition) and isotopic analyses as well as toxicological assessment in cooperation with several institutions (Karlsruhe Institute of Technology (IfGG/IMG), Helmholtz Zentrum München (HMGU), University Rostock (UR), Chinese University of Mining and Technology Beijing, CUMTB) will be discussed. b) The impact of dust storm events on the overall pollution level of particulate matter in the greater area of Beijing is being assessed by the online coupled comprehensive model system COSMO-ART. First results of the dust storm modeling in northern China (2011, April 30th) demonstrates very well the general behavior of the meteorological parameters temperature and humidity as well as a good agreement between modeled and measured dust storm concentration variability at Beijing in the course of time. The results show the importance of intertwine investigations of measurements and modeling, the analysis of local air pollution levels as well as the impact and analysis of advective processes in the greater region of Beijing. Comprehensive investigations on particulate matter are a prerequisite for the knowledge of the source strengths and source attribution to the overall air pollution level. Only this knowledge can help to formulate and to introduce specific reduction measures to reduce coarser as well as finer particulates.

  9. Identification of physicians providing comprehensive primary care in Ontario: a retrospective analysis using linked administrative data.

    PubMed

    Schultz, Susan E; Glazier, Richard H

    2017-12-19

    Given the changing landscape of primary care, there may be fewer primary care physicians available to provide a broad range of services to patients of all age groups and health conditions. We sought to identify physicians with comprehensive primary care practices in Ontario using administrative data, investigating how many and what proportion of primary care physicians provided comprehensive primary care and how this changed over time. We identified the pool of active primary care physicians in linked population-based databases for Ontario from 1992/93 to 2014/15. After excluding those who saw patients fewer than 44 days per year, we identified physicians as providing comprehensive care if more than half of their services were for core primary care and if these services fell into at least 7 of 22 activity areas. Physicians with 50% or less of their services for core primary care but with more than 50% in a single location or type of service were identified as being in focused practice. In 2014/15, there were 12 891 physicians in the primary care pool: 1254 (9.7%) worked fewer than 44 days per year, 1619 (12.6%) were in focused practice, and 1009 (7.8%) could not be classified. The proportion in comprehensive practice ranged from 67.5% to 74.9% between 1992/93 and 2014/15, with a peak in 2002/03 and relative stability from 2009/10 to 2014/15. Over this period, there was an increase of 8.8% in population per comprehensive primary care physician. We found that just over two-thirds of primary care physicians provided comprehensive care in 2014/15, which indicates that traditional estimates of the primary care physician workforce may be too high. Although implementation will vary by setting and available data, this approach is likely applicable elsewhere. Copyright 2017, Joule Inc. or its licensors.

  10. Guided Comprehension in the Primary Grades.

    ERIC Educational Resources Information Center

    McLaughlin, Maureen

    Intended as a response to recent developments in reading research and a demand by primary-grade teachers for a comprehension-based instructional framework, this book adapts the Guided Comprehension Model introduced in the author/educator's book "Guided Comprehension: A Teaching Model for Grades 3-8." According to the book, the Guided…

  11. Bulk Magnetization Effects in EMI-Based Classification and Discrimination

    DTIC Science & Technology

    2012-04-01

    response adds to classification performance and ( 2 ) develop a comprehensive understanding of the engineering challenges of primary field cancellation...response adds to classification performance and ( 2 ) develop a comprehensive understanding of the engineering challenges of primary field cancellation...classification performance and ( 2 ) develop a comprehensive understanding of the engineering challenges of primary field cancellation that can support a

  12. Processing and Analysis of Multibeam Sonar Data and Images near the Yellow River Estuary

    NASA Astrophysics Data System (ADS)

    Tang, Q.

    2017-12-01

    Yellow River Estuary is a typical high-suspended particulate matter estuary in the world. A lot of sediments from Yellow River and other substances produced by human activity cause high-concentration suspended matter and depositional system in the estuary and adjacent water area. Multibeam echo sounder (MBES) was developed in the 1970s, and it not only provided high-precision bathymetric data, but also provided seabed backscatter strength data and water column data with high temporal and spatial resolution. Here, based on high-precision sonar data of the seabed and water column collected by SeaBat7125 MBES system near the Yellow River Estuary, we use advanced data and image processing methods to generate seabed sonar images and water suspended particulate matter acoustic images. By analyzing these data and images, we get a lot of details of the seabed and whole water column features, and we also acquire their shape, size and basic physical characteristics of suspended particulate matters in the experiment area near the Yellow River Estuary. This study shows great potential for monitoring suspended particulate matter use MBES, and the research results will contribute to a comprehensive understanding of sediment transportation, evolution of river trough and shoal in Yellow River Estuary.

  13. Spatio-Temporal Distribution of Particulate and Dissolved Organic Matter in the Mississippi River Bight From Optical Measurements

    NASA Technical Reports Server (NTRS)

    DSa, E. J.; Miller, R. L.; DelCastillo, C.

    2003-01-01

    The Mississippi River Bight is a highly dynamic region influenced by the seasonally variable outflow from the Mississippi River. In an effort to characterize the distribution of particulate and dissolved organic matter in the region, we conducted a two-year field program in the spring and fall (high and low flow river discharge) of 2000 and 2002. We collected a comprehensive set of bio-optical measurements consisting of vertical profiles (absorption, scattering, chlorophyll fluorescence and radiometry) and discrete measurements (pigment concentrations, particulate and CDOM absorption) that enabled us to obtain better insight into the seasonal and spatial variability of some important biogeochemical parameters. Our field measurements generally showed higher phytoplankton clorophyll concentrations in the plume waters (associated with lower surface salinities) and confirmed the high biological activity abserved in other studies. The seasonal flow of river discharge and advective currents due to wind forcing exerted a strong influence on the biological and optical properties of the region. An examination of absorption at 440 nm by the algal and non-algal fraction of the particulate pool and of CDOM revealed that at nearshore stations, contributions by the non-algal particles were high (about 40%) and decresed with increasing salinities. While CDOM absorption exhibited conservative mixing, its relative contribution to the total absorption was variable. Surface waters at most stations had lower salinities that generalliy increased with dept. Particulate matter and CDOM also decreased with depth as evidenced by absorption and scattering measurements. Good correlations in surface waters between concentrations of particulate and dissolved matter, the inherent optical properties of absorption and ackscattering and remote sensing reflectance values has allowed the development of robust empirical algorithms for phytoplankton chlorophyll and CDOM absorption.

  14. PRIMARY PARTICLES GENERATED BY THE COMBUSTION OF HEAVY FUEL OIL AND COAL: REVIEW OF RESEARCH RESULTS FROM EPA'S NATIONAL RISK MANAGEMENT RESEARCH LABORATORY

    EPA Science Inventory

    Researchers at the U.S. Environmental Protection Agency's (EPA's) Office of Research and
    Development (ORD) have conducted a series of tests to characterize the size and composition of primary particulate matter (PM) generated from the combustion of heavy fuel oil and pulverize...

  15. Emissions from diesel versus biodiesel fuel used in a CRDI SUV engine: PM mass and chemical composition.

    PubMed

    Gangwar, Jitendra; Gupta, Tarun; Gupta, Sudhir; Agarwal, Avinash K

    2011-07-01

    The diesel tailpipe emissions typically undergo substantial physical and chemical transformations while traveling through the tailpipe, which tend to modify the original characteristics of the diesel exhaust. Most of the health-related attention for diesel exhaust has focused on the carcinogenic potential of inhaled exhaust components, particularly the highly respirable diesel particulate matter (DPM). In the current study, parametric investigations were made using a modern automotive common rail direct injection (CRDI) sports utility vehicle (SUV) diesel engine operated at different loads at constant engine speed (2400 rpm), employing diesel and 20% biodiesel blends (B20) produced from karanja oil. A partial flow dilution tunnel was employed to measure the mass of the primary particulates from diesel and biodiesel blend on a 47-mm quartz substrate. This was followed by chemical analysis of the particulates collected on the substrate for benzene-soluble organic fraction (BSOF) (marker of toxicity). BSOF results showed decrease in its level with increasing engine load for both diesel and biodiesel. In addition, real-time measurements for organic carbon/elemental carbon (OC/EC), and polycyclic aromatic hydrocarbons (PAHs) (marker of toxicity) were carried out on the diluted primary exhaust coming out of the partial flow dilution tunnel. PAH concentrations were found to be the maximum at 20% rated engine load for both the fuels. The collected particulates from diesel and biodiesel-blend exhaust were also analyzed for concentration of trace metals (marker of toxicity), which revealed some interesting results.

  16. Air cleaning performance of a new environmentally controlled primary crusher operator booth.

    PubMed

    Organiscak, J A; Cecala, A B; Zimmer, J A; Holen, B; Baregi, J R

    2016-02-01

    The National Institute for Occupational Safety and Health (NIOSH) cooperated with 3M Company in the design and testing of a new environmentally controlled primary crusher operator booth at the company's Wausau granite quarry near Wausau, WI. This quarry had an older crusher booth without a central heating, ventilation and air conditioning (HVAC) system, and without an air filtration and pressurization system. A new replacement operator booth was designed and installed by 3M based on design considerations from past NIOSH research on enclosed cab filtration systems. NIOSH conducted pre-testing of the old booth and post-testing of the new booth to assess the new filtration and pressurization system's effectiveness in controlling airborne dusts and particulates. The booth's dust and particulate control effectiveness is described by its protection factor, expressed as a ratio of the outside to inside concentrations measured during testing. Results indicate that the old booth provided negligible airborne respirable dust protection and low particulate protection from the outside environment. The newly installed booth provided average respirable dust protection factors from 2 to 25 over five shifts of dust sampling with occasional worker ingress and egress from the booth, allowing some unfiltered contaminants to enter the enclosure. Shorter-term particle count testing outside and inside the booth under near-steady-state conditions, with no workers entering or exiting the booth, resulted in protection factors from 35 to 127 on 0.3- to 1.0-μm respirable size particulates under various HVAC airflow operating conditions.

  17. Composition and oxidation state of sulfur in atmospheric particulate matter

    NASA Astrophysics Data System (ADS)

    Longo, Amelia F.; Vine, David J.; King, Laura E.; Oakes, Michelle; Weber, Rodney J.; Huey, Lewis Gregory; Russell, Armistead G.; Ingall, Ellery D.

    2016-10-01

    The chemical and physical speciation of atmospheric sulfur was investigated in ambient aerosol samples using a combination of sulfur near-edge x-ray fluorescence spectroscopy (S-NEXFS) and X-ray fluorescence (XRF) microscopy. These techniques were used to determine the composition and oxidation state of sulfur in common primary emission sources and ambient particulate matter collected from the greater Atlanta area. Ambient particulate matter samples contained two oxidation states: S0 and S+VI. Ninety-five percent of the individual aerosol particles (> 1 µm) analyzed contain S0. Linear combination fitting revealed that S+VI in ambient aerosol was dominated by ammonium sulfate as well as metal sulfates. The finding of metal sulfates provides further evidence for acidic reactions that solubilize metals, such as iron, during atmospheric transport. Emission sources, including biomass burning, coal fly ash, gasoline, diesel, volcanic ash, and aerosolized Atlanta soil, and the commercially available bacterium Bacillus subtilis, contained only S+VI. A commercially available Azotobacter vinelandii sample contained approximately equal proportions of S0 and S+VI. S0 in individual aerosol particles most likely originates from primary emission sources, such as aerosolized bacteria or incomplete combustion.

  18. Carbonaceous aerosols in fine particulate matter of Santiago Metropolitan Area, Chile.

    PubMed

    Toro Araya, Richard; Flocchini, Robert; Morales Segura, Rául G E; Leiva Guzmán, Manuel A

    2014-01-01

    Measurements of carbonaceous aerosols in South American cities are limited, and most existing data are of short term and limited to only a few locations. For 6 years (2002-2007), concentrations of fine particulate matter and organic and elemental carbon were measured continuously in the capital of Chile. The contribution of carbonaceous aerosols to the primary and secondary fractions was estimated at three different sampling sites and in the warm and cool seasons. The results demonstrate that there are significant differences in the levels in both the cold (March to August) and warm (September to February) seasons at all sites studied. The percent contribution of total carbonaceous aerosol fine particulate matter was greater in the cool season (53 ± 41%) than in the warm season (44 ± 18%). On average, the secondary organic carbon in the city corresponded to 29% of the total organic carbon. In cold periods, this proportion may reach an average of 38%. A comparison of the results with the air quality standards for fine particulate matter indicates that the total carbonaceous fraction alone exceeds the World Health Organization standard (10 µg/m(3)) and the United States Environmental Protection Agency standard (15 µg/m(3)) for fine particulate matter.

  19. Nuclei-mode particulate emissions and their response to fuel sulfur content and primary dilution during transient operations of old and modern diesel engines.

    PubMed

    Liu, Z Gerald; Vasys, Victoria N; Kittelson, David B

    2007-09-15

    The effects of fuel sulfur content and primary dilution on PM number emissions were investigated during transient operations of an old and a modern diesel engine. Emissions were also studied during steady-state operations in order to confirm consistency with previous findings. Testing methods were concurrent with those implemented by the EPA to regulate PM mass emissions, including the use of the Federal Transient Testing Procedure-Heavy Duty cycle to simulate transient conditions and the use of a Critical Flow Venturi-Constant Volume System to provide primary dilution. Steady-state results were found to be consistent with previous studies in that nuclei-mode particulate emissions were largely reduced when lower-sulfur content fuel was used in the newer engine, while the nuclei-mode PM emissions from the older engine were much less affected by fuel sulfur content. The transient results, however, show that the total number of nuclei-mode PM emissions from both engines increases with fuel sulfur content, although this effect is only seen under the higher primary dilution ratios with the older engine. Transient results further show that higher primary dilution ratios increase total nuclei-mode PM number emissions in both engines.

  20. Radionuclide observables during the Integrated Field Exercise of the Comprehensive Nuclear-Test-Ban Treaty

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Burnett, Jonathan L.; Miley, Harry S.; Milbrath, Brian D.

    In 2014 the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) undertook the Integrated Field Exercise (IFE) in Jordan. The exercise consisted of a simulated 0.5 – 2 kT underground explosion triggering an On-site Inspection (OSI) to search for evidence of a Treaty violation. This research evaluates two of the OSI techniques, including laboratory-based gamma-spectrometry of soil samples and in situ gamma-spectrometry for 17 particulate radionuclides indicative of nuclear weapon tests. The detection sensitivity is evaluated using real IFE and model data. It indicates that higher sensitivity laboratory measurements are the optimum technique during the IFE and OSI timeframes.

  1. Modeling green infrastructure land use changes on future air ...

    EPA Pesticide Factsheets

    Green infrastructure can be a cost-effective approach for reducing stormwater runoff and improving water quality as a result, but it could also bring co-benefits for air quality: less impervious surfaces and more vegetation can decrease the urban heat island effect, and also result in more removal of air pollutants via dry deposition with increased vegetative surfaces. Cooler surface temperatures can also decrease ozone formation through the increases of NOx titration; however, cooler surface temperatures also lower the height of the boundary layer resulting in more concentrated pollutants within the same volume of air, especially for primary emitted pollutants (e.g. NOx, CO, primary particulate matter). To better understand how green infrastructure impacts air quality, the interactions between all of these processes must be considered collectively. In this study, we use a comprehensive coupled meteorology-air quality model (WRF-CMAQ) to simulate the influence of planned land use changes that include green infrastructure in Kansas City (KC) on regional meteorology and air quality. Current and future land use data was provided by the Mid-America Regional Council for 2012 and 2040 (projected land use due to population growth, city planning and green infrastructure implementation). These land use datasets were incorporated into the WRF-CMAQ modeling system allowing the modeling system to propagate the changes in vegetation and impervious surface coverage on meteoro

  2. 40 CFR 52.1880 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... requirements in the federally approved SIP remain in effect. See § 52.1870(c)(27). (j) Approval—EPA is...) for the Huntington-Ashland area. (3) Ohio's 2005 NOX, primary PM2.5, and SO2 and 2007/2008 ammonia and... Clean Air Act for Washington County. (4) Ohio's 2005 NOX, primary PM2.5, and SO2 and 2007/2008 ammonia...

  3. Primary Teachers' Particle Ideas and Explanations of Physical Phenomena: Effect of an In-Service Training Course

    ERIC Educational Resources Information Center

    Papageorgiou, George; Stamovlasis, Dimitrios; Johnson, Phil Michael

    2010-01-01

    This paper presents a study concerning Greek primary school teachers' (n = 162) ideas about the particulate nature of matter and their explanations of physical phenomena. The study took place during an in-service training course where the effectiveness of a specially designed intervention was tested. A key feature was an approach based on the…

  4. Transport of particle-associated elements in two agriculture-dominated boreal river systems.

    PubMed

    Marttila, Hannu; Saarinen, Tuomas; Celebi, Ahmet; Kløve, Bjørn

    2013-09-01

    Transport of particulate pollutants in fluvial systems can contribute greatly to total loads. Understanding transport mechanics under different hydrological conditions is key in successful load estimation. This study analysed trace elements and physico-chemical parameters in time-integrated suspended sediment samples, together with dissolved and total concentrations of pollutants, along two agriculture- and peatland-dominated boreal river systems. The samples were taken in a spatially and temporally comprehensive sampling programme during the ice-free seasons of 2010 and 2011. The hydrochemistry and transport of particle-bound elements in the rivers were strongly linked to intense land use and acid sulphate soils in the catchment area, with arable, pasture and peat areas in particular being main diffuse sources. There were significant seasonal and temporal variations in dissolved and particulate fluxes, but spatial variations were small. Continuous measurements of EC, turbidity and discharge proved to be an accurate indicator of dissolved and particulate fluxes. Overall, the results show that transport of particle-bound elements makes a major contribution to total transport fluxes in agriculture-dominated boreal rivers. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Particulate matter emissions from biochar-amended soils as a potential tradeoff to the negative emission potential

    NASA Astrophysics Data System (ADS)

    Ravi, Sujith; Sharratt, Brenton S.; Li, Junran; Olshevski, Stuart; Meng, Zhongju; Zhang, Jianguo

    2016-10-01

    Novel carbon sequestration strategies such as large-scale land application of biochar may provide sustainable pathways to increase the terrestrial storage of carbon. Biochar has a long residence time in the soil and hence comprehensive studies are urgently needed to quantify the environmental impacts of large-scale biochar application. In particular, black carbon emissions from soils amended with biochar may counteract the negative emission potential due to the impacts on air quality, climate, and biogeochemical cycles. We investigated, using wind tunnel experiments, the particulate matter emission potential of a sand and two agriculturally important soils amended with different concentrations of biochar, in comparison to control soils. Our results indicate that biochar application considerably increases particulate emissions possibly by two mechanisms-the accelerated emission of fine biochar particles and the generation and emission of fine biochar particles resulting from abrasion of large biochar particles by sand grains. Our study highlights the importance of considering the background soil properties (e.g., texture) and geomorphological processes (e.g., aeolian transport) for biochar-based carbon sequestration programs.

  6. Nutrient utilisation and particulate organic matter changes during summer in the upper mixed layer (Ross Sea, Antarctica)

    NASA Astrophysics Data System (ADS)

    Catalano, G.; Povero, P.; Fabiano, M.; Benedetti, F.; Goffart, A.

    1997-01-01

    The relationships among vertical stability, estimated nutrient utilisation and particulate organic matter in the Ross Sea are analysed from data collected during two cruises in the summers of 1987-1988 and 1989-1990. In the upper mixed layer (UML), identified through the vertical stability E( Z(UML)), nutrient consumption is calculated as the difference between the "diluted" nutrient value and the mean calculated from the integrated value in the UML. The nutrient utilisation ratio and E( Z(UML)) are linearly related for E( Z(UML))≤25, whereas for values > 25, the distribution pattern is more scattered and independent of E( Z(UML)). For E( Z(UML))≥25, utilisation values were ≥4, 0.4 and 10 mmol m -3 for nitrate, phosphate and silicate, respectively. Significant relationships between nutrient depletion and both particulate organic carbon (POC) and particulate protein/particulate carbohydrate ratios (PPRT/PCHO) are found. The analysis of particulate matter distribution vs nutrient utilisation shows that the stations could be divided into two groups having different characteristics. The first group includes coastal stations, where high nutrient utilisation, POC and PPRT/PCHO are typical of areas with high production. In the second group (pelagic stations), nutrient utilisation, POC and PPRT/PCHO are lower. The vertical stability can be used to discriminate among the factors that influence primary production.

  7. Advanced Hybrid Particulate Collector Project Management Plan

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Miller, S.J.

    As the consumption of energy increases, its impact on ambient air quality has become a significant concern. Recent studies indicate that fine particles from coal combustion cause health problems as well as atmospheric visibility impairment. These problems are further compounded by the concentration of hazardous trace elements such as mercury, cadmium, selenium, and arsenic in fine particles. Therefore, a current need exists to develop superior, but economical, methods to control emissions of fine particles. Since most of the toxic metals present in coal will be in particulate form, a high level of fine- particle collection appears to be the bestmore » method of overall air toxics control. However, over 50% of mercury and a portion of selenium emissions are in vapor form and cannot be collected in particulate control devices. Therefore, this project will focus on developing technology not only to provide ultrahigh collection efficiency of particulate air toxic emissions, but also to capture vapor- phase trace metals such as mercury and selenium. Currently, the primary state-of-the-art technologies for particulate control are fabric filters (baghouses) and electrostatic precipitators (ESPs). However, they both have limitations that prevent them from achieving ultrahigh collection of fine particulate matter and vapor-phase trace metals. The objective of this project is to develop a highly reliable advanced hybrid particulate collector (AHPC) that can provide > 99.99 % particulate collection efficiency for all particle sizes between 0.01 and 50 14m, is applicable for use with all U.S. coals, and is cost-0443competitive with existing technologies. Phase I of the project is organized into three tasks: Task I - Project Management, Reporting, and Subcontract Consulting Task 2 - Modeling, Design, and Construction of 200-acfm AHPC Model Task 3 - Experimental Testing and Subcontract Consulting« less

  8. Bidirectional Relations between Text Reading Prosody and Reading Comprehension in the Upper Primary School Grades: A Longitudinal Perspective

    ERIC Educational Resources Information Center

    Veenendaal, Nathalie J.; Groen, Margriet A.; Verhoeven, Ludo

    2016-01-01

    The purpose of this study was to examine the directionality of the relationship between text reading prosody and reading comprehension in the upper grades of primary school. We compared 3 theoretical possibilities: Two unidirectional relations from text reading prosody to reading comprehension and from reading comprehension to text reading prosody…

  9. Theoretical Models of Comprehension Skills Tested through a Comprehension Assessment Battery for Primary School Children

    ERIC Educational Resources Information Center

    Tobia, Valentina; Ciancaleoni, Matteo; Bonifacci, Paola

    2017-01-01

    In this study, two alternative theoretical models were compared, in order to analyze which of them best explains primary school children's text comprehension skills. The first one was based on the distinction between two types of answers requested by the comprehension test: local or global. The second model involved texts' input modality: written…

  10. Improving 4th Grade Primary School Students' Reading Comprehension Skills

    ERIC Educational Resources Information Center

    Bulut, Aydin

    2017-01-01

    The aim of this study was to carry out action research to investigate reading comprehension skills when using the SQ3R reading comprehension strategy. To that end, this strategy was used for improving the reading comprehension skills of 7 primary school 4th grade students who had problems with these skills. An action plan was prepared for 3hours a…

  11. The relationship between sun protection policies and practices in schools with primary-age students: the role of school demographics, policy comprehensiveness and SunSmart membership.

    PubMed

    Dono, J; Ettridge, K A; Sharplin, G R; Wilson, C J

    2014-02-01

    Schools can implement evidence-based sun protection policies that guide practices to help protect children from harmful sun exposure. This national study assessed the relationship between the existence and comprehensiveness of written policies and the comprehensiveness of sun protection practices. The impact of school demographics on the strength of the relationship was also examined, as was the possibility that 'SunSmart' membership would have an additional impact on practices, beyond having any formal policy. In 2011-12, staff members of 1573 schools catering to primary-age students completed a self-administered survey about sun protection policies and practices (response rate of 57%). Results showed that schools with a written policy had more comprehensive practices than schools without a written policy. The relationship between having a written policy and sun protection practices was stronger for remote schools compared with metropolitan and regional schools, and for schools catering to both primary and secondary students compared with primary students only. In addition, policy comprehensiveness was associated with practice comprehensiveness, and SunSmart membership was indirectly related to practice comprehensiveness via policy comprehensiveness. These results indicate that written policies relate to practice comprehensiveness, but the strength of the association can vary according to the characteristics of the organization.

  12. A Comprehensive Program for Measurement of Military Aircraft Emissions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cheng, Mengdawn

    2009-11-01

    Emissions of gases and particulate matter by military aircraft were characterized inplume by 'extractive' and 'optical remote-sensing (ORS)' technologies. Non-volatile particle size distribution, number and mass concentrations were measured with good precision and reproducibly. Time-integrated particulate filter samples were collected and analyzed for smoke number, elemental composition, carbon contents, and sulfate. Observed at EEP the geometric mean diameter (as measured by the mobility diameter) generally increased as the engine power setting increased, which is consistent with downstream observations. The modal diameters at the downstream locations are larger than that at EEP at the same engine power level. The results indicatemore » that engine particles were processed by condensation, for example, leading to particle growth in-plume. Elemental analysis indicated little metals were present in the exhaust, while most of the exhaust materials in the particulate phase were carbon and sulfate (in the JP-8 fuel). CO, CO{sub 2}, NO, NO{sub 2}, SO{sub 2}, HCHO, ethylene, acetylene, propylene, and alkanes were measured. The last five species were most noticeable under engine idle condition. The levels of hydrocarbons emitted at high engine power level were generally below the detection limits. ORS techniques yielded real-time gaseous measurement, but the same techniques could not be extended directly to ultrafine particles found in all engine exhausts. The results validated sampling methodology and measurement techniques used for non-volatile particulate aircraft emissions, which also highlighted the needs for further research on sampling and measurement for volatile particulate matter and semi-volatile species in the engine exhaust especially at the low engine power setting.« less

  13. Headspace solid-phase microextraction coupled to comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry for the analysis of aerosol from tobacco heating product.

    PubMed

    Savareear, Benjamin; Lizak, Radoslaw; Brokl, Michał; Wright, Chris; Liu, Chuan; Focant, Jean-Francois

    2017-10-20

    A method involving headspace solid-phase microextraction (HS-SPME) and comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-TOFMS) was developed and optimised to elucidate the volatile composition of the particulate phase fraction of aerosol produced by tobacco heating products (THPs). Three SPME fiber types were studied in terms of extraction capacity and precision measurements. Divinylbenzene polydimethylsiloxane appeared as the most efficient coating for these measurements. A central composite design of experiment was utilised for the optimization of the extraction conditions. Qualitative and semi-quantitative analysis of the headspace above THP aerosol condensate was carried out using optimised extraction conditions. Semi-quantitative analyses of detected constituents were performed by assuming that their relative response factors to the closest internal standard ( i t R ) were equal to 1. Using deconvoluted mass spectral data (library similarity and reverse match >750) and linear retention indices (match window of ±15 index units), 205 peaks were assigned to individual compounds, 82 of which (including 43 substances previously reported to be present in tobacco) have not been reported previously in tobacco aerosol. The major volatile fraction of the headspace contained ketones, alcohols, aldehydes, alicyclic hydrocarbons alkenes, and alkanes. The method was further applied to compare the volatiles from the particulate phase of aerosol composition of THP with that of reference cigarette smoke and showed that the THP produced a less complex chemical mixture. This new method showed good efficiency and precision for the peak areas and peak numbers from the volatile fraction of aerosol particulate phase for both THP and reference cigarettes. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Air cleaning performance of a new environmentally controlled primary crusher operator booth

    PubMed Central

    Organiscak, J.A.; Cecala, A.B.; Zimmer, J.A.; Holen, B.; Baregi, J.R.

    2016-01-01

    The National Institute for Occupational Safety and Health (NIOSH) cooperated with 3M Company in the design and testing of a new environmentally controlled primary crusher operator booth at the company’s Wausau granite quarry near Wausau, WI. This quarry had an older crusher booth without a central heating, ventilation and air conditioning (HVAC) system, and without an air filtration and pressurization system. A new replacement operator booth was designed and installed by 3M based on design considerations from past NIOSH research on enclosed cab filtration systems. NIOSH conducted pre-testing of the old booth and post-testing of the new booth to assess the new filtration and pressurization system’s effectiveness in controlling airborne dusts and particulates. The booth’s dust and particulate control effectiveness is described by its protection factor, expressed as a ratio of the outside to inside concentrations measured during testing. Results indicate that the old booth provided negligible airborne respirable dust protection and low particulate protection from the outside environment. The newly installed booth provided average respirable dust protection factors from 2 to 25 over five shifts of dust sampling with occasional worker ingress and egress from the booth, allowing some unfiltered contaminants to enter the enclosure. Shorter-term particle count testing outside and inside the booth under near-steady-state conditions, with no workers entering or exiting the booth, resulted in protection factors from 35 to 127 on 0.3- to 1.0-μm respirable size particulates under various HVAC airflow operating conditions. PMID:26937052

  15. The Unique Properties of Agricultural Aerosols Measured at a Cattle Feeding Operation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hiranuma, Naruki; Brooks, S. D.; Gramann, J.

    2011-05-11

    Housing roughly 10 million head of cattle in the United States alone, open air cattle feedlots represent a significant but poorly constrained source of atmospheric particles. Here we present a comprehensive characterization of physical and chemical properties of particles emitted from a large representative cattle feedlot in the Southwest United States. In the summer of 2008, measurements and samplings were conducted at the nominally upwind and downwind edges of the facility. A series of far-field measurements and samplings was also conducted 3.5 km north of the facility. Two instruments, a GRIMM Sequential Mobility Particle Sizer (SMPS) and a GRIMM Portablemore » Aerosol Spectrometer (PAS), were used to measure particle size distributions over the range of 0.01 to 25 μm diameter. Raman microspectroscopy (RM) was used to determine the chemical composition of particles on a single particle basis. Volume size distributions of fugitive dust were dominated by coarse mode particles. Twenty-four hour averaged concentrations of PM10 (particulate matter with a diameter of 10 µm or less) were as high as 1200 μg/m3 during the campaign. The primary constituents of the particulate matter were carbonaceous materials, such as humic acid, water soluble organics, and less soluble fatty acids, including stearic acid and tristearin. A significant fraction of the organic particles was composed of internally mixed with salts. Basic characteristics such as size distribution and composition of agricultural aerosols were found to be different than the properties of those found in urban and semi-urban aerosols. Failing to account for such differences will lead to serious errors in estimates of aerosol effects on climate, visibility, and public health.« less

  16. The unique properties of agricultural aerosols measured at a cattle feeding operation

    NASA Astrophysics Data System (ADS)

    Hiranuma, N.; Brooks, S. D.; Gramann, J.; Auvermann, B. W.

    2011-05-01

    Housing roughly 10 million head of cattle in the United States alone, open air cattle feedlots represent a significant but poorly constrained source of atmospheric particles. Here we present a comprehensive characterization of physical and chemical properties of particles emitted from a large representative cattle feedlot in the Southwest United States. In the summer of 2008, measurements and samplings were conducted at the nominally upwind and downwind edges of the facility. A series of far-field measurements and samplings was also conducted 3.5 km north of the facility. Two instruments, a GRIMM Sequential Mobility Particle Sizer (SMPS) and a GRIMM Portable Aerosol Spectrometer (PAS), were used to measure particle size distributions over the range of 0.01 to 25 μm diameter. Raman microspectroscopy (RM) was used to determine the chemical composition of particles on a single particle basis. Volume size distributions of fugitive dust were dominated by coarse mode particles. Twenty-four hour averaged concentrations of PM10 (particulate matter with a diameter of 10 μm or less) were as high as 1200 μg m-3 during the campaign. The primary constituents of the particulate matter were carbonaceous materials, such as humic acid, water soluble organics, and less soluble fatty acids, including stearic acid and tristearin. A significant percentage of the organic particles, up to 28 %, were composed of internally mixed with salts. Basic characteristics such as size distribution and composition of agricultural aerosols were found to be different than the properties of those found in urban and semi-urban aerosols. Failing to account for such differences will lead to serious errors in estimates of aerosol effects on climate, visibility, and public health.

  17. High concentrations of coarse particles emitted from a cattle feeding operation

    NASA Astrophysics Data System (ADS)

    Hiranuma, N.; Brooks, S. D.; Gramann, J.; Auvermann, B. W.

    2011-08-01

    Housing roughly 10 million head of cattle in the United States alone, open air cattle feedlots represent a significant but poorly constrained source of atmospheric particles. Here we present a comprehensive characterization of physical and chemical properties of particles emitted from a large representative cattle feedlot in the Southwest United States. In the summer of 2008, measurements and samplings were conducted at the upwind and downwind edges of the facility. A series of far-field measurements and samplings was also conducted 3.5 km north of the facility. Two instruments, a GRIMM Sequential Mobility Particle Sizer (SMPS) and a GRIMM Portable Aerosol Spectrometer (PAS), were used to measure particle size distributions over the range of 0.01 to 25 μm diameter. Raman microspectroscopy was used to determine the chemical composition of particles on a single particle basis. Volume size distributions of dust were dominated by coarse mode particles. Twenty-four hour averaged concentrations of PM10 (particulate matter with a diameter of 10 μm or less) were as high as 1200 μg m-3 during the campaign. The primary constituents of the particulate matter were carbonaceous materials, such as humic acid, water soluble organics, and less soluble fatty acids, including stearic acid and tristearin. A significant fraction of the organic particles was present in internal mixtures with salts. Basic characteristics such as size distribution and composition of agricultural aerosols were found to be different than the properties of those found in urban and semi-urban aerosols. Failing to account for such differences may lead to errors in estimates of aerosol effects on local air quality, visibility, and public health.

  18. Diesel-related hydrocarbons can dominate gas phase reactive carbon in megacities

    NASA Astrophysics Data System (ADS)

    Dunmore, R. E.; Hopkins, J. R.; Lidster, R. T.; Lee, J. D.; Evans, M. J.; Rickard, A. R.; Lewis, A. C.; Hamilton, J. F.

    2015-09-01

    Hydrocarbons are key precursors to two priority air pollutants, ozone and particulate matter. Those with two to seven carbons have historically been straightforward to observe and have been successfully reduced in many developed cities through air quality policy interventions. Longer chain hydrocarbons released from diesel vehicles are not considered explicitly as part of air quality strategies and there are few direct measurements of their gaseous abundance in the atmosphere. This study describes the chemically comprehensive and continuous measurements of organic compounds in a developed megacity (London), which demonstrate that on a seasonal median basis, diesel-related hydrocarbons represent only 20-30 % of the total hydrocarbon mixing ratio but comprise more than 50 % of the atmospheric hydrocarbon mass and are a dominant local source of secondary organic aerosols. This study shows for the first time that 60 % of the winter primary hydrocarbon hydroxyl radical reactivity is from diesel-related hydrocarbons and using the maximum incremental reactivity scale, we predict that they contribute up to 50 % of the ozone production potential in London. Comparing real-world urban composition with regulatory emissions inventories in the UK and US highlights a previously unaccounted for, but very significant, under-reporting of diesel-related hydrocarbons; an underestimation of a factor ~4 for C9 species rising to a factor of over 70 for C12 during winter. These observations show that hydrocarbons from diesel vehicles can dominate gas phase reactive carbon in cities with high diesel fleet fractions. Future control of urban particulate matter and ozone in such locations requires a shift in policy focus onto gas phase hydrocarbons released from diesels as this vehicle type continues to displace gasoline world-wide.

  19. Diesel-related hydrocarbons can dominate gas phase reactive carbon in megacities

    NASA Astrophysics Data System (ADS)

    Dunmore, R. E.; Hopkins, J. R.; Lidster, R. T.; Lee, J. D.; Evans, M. J.; Rickard, A. R.; Lewis, A. C.; Hamilton, J. F.

    2015-03-01

    Hydrocarbons are key precursors to two priority air pollutants, ozone and particulate matter. Those with two to seven carbons have historically been straightforward to observe and have been successfully reduced in many developed cities through air quality policy interventions. Longer chain hydrocarbons released from diesel vehicles are not considered explicitly as part of air quality strategies and there are few direct measurements of their gaseous abundance in the atmosphere. This study describes the chemically comprehensive and continuous measurements of organic compounds in a developed megacity (London), which demonstrate that on a seasonal median basis, diesel-related hydrocarbons represent only 20-30% of the total hydrocarbon mixing ratio but comprise more than 50% of the atmospheric hydrocarbon mass and are a dominant local source of secondary organic aerosols. This study shows for the first time that, 60% of the winter primary hydrocarbon hydroxyl radical reactivity is from diesel-related hydrocarbons and using the maximum incremental reactivity scale, we predict that they contribute up to 50% of the ozone production potential in London. Comparing real-world urban composition with regulatory emissions inventories in the UK and US highlights a previously unaccounted for but, very significant under-reporting of diesel related hydrocarbons; an underestimation of a factor ~ 4 for C9 species rising to a factor of over 70 for C12 during winter. These observations show that hydrocarbons from diesel vehicles can dominate gas phase reactive carbon in cities with high diesel fleet fractions. Future control of urban particulate matter and ozone in such locations requires a shift in policy focus onto gas phase hydrocarbons released from diesels as this vehicle type continues to displace gasoline world-wide.

  20. Comprehensiveness of care from the patient perspective: comparison of primary healthcare evaluation instruments.

    PubMed

    Haggerty, Jeannie L; Beaulieu, Marie-Dominique; Pineault, Raynald; Burge, Frederick; Lévesque, Jean-Frédéric; Santor, Darcy A; Bouharaoui, Fatima; Beaulieu, Christine

    2011-12-01

    Comprehensiveness relates both to scope of services offered and to a whole-person clinical approach. Comprehensive services are defined as "the provision, either directly or indirectly, of a full range of services to meet most patients' healthcare needs"; whole-person care is "the extent to which a provider elicits and considers the physical, emotional and social aspects of a patient's health and considers the community context in their care." Among instruments that evaluate primary healthcare, two had subscales that mapped to comprehensive services and to the community component of whole-person care: the Primary Care Assessment Tool - Short Form (PCAT-S) and the Components of Primary Care Index (CPCI, a limited measure of whole-person care). To examine how well comprehensiveness is captured in validated instruments that evaluate primary healthcare from the patient's perspective. 645 adults with at least one healthcare contact in the previous 12 months responded to six instruments that evaluate primary healthcare. Scores were normalized for descriptive comparison. Exploratory and confirmatory (structural equation modelling) factor analysis examined fit to operational definition, and item response theory analysis examined item performance on common constructs. Over one-quarter of respondents had missing responses on services offered or doctor's knowledge of the community. The subscales did not load on a single factor; comprehensive services and community orientation were examined separately. The community orientation subscales did not perform satisfactorily. The three comprehensive services subscales fit very modestly onto two factors: (1) most healthcare needs (from one provider) (CPCI Comprehensive Care, PCAT-S First-Contact Utilization) and (2) range of services (PCAT-S Comprehensive Services Available). Individual item performance revealed several problems. Measurement of comprehensiveness is problematic, making this attribute a priority for measure development. Range of services offered is best obtained from providers. Whole-person care is not addressed as a separate construct, but some dimensions are covered by attributes such as interpersonal communication and relational continuity.

  1. Sedimentary particulate iron: the missing micronutrients ?

    NASA Astrophysics Data System (ADS)

    Beghoura, Houda; Gorgues, Thomas; Aumont, Olivier; Planquette, Hélène

    2017-04-01

    Iron is known to regulate the marine primary production and to impact the structure of ecosystems. Indeed, iron is the limiting nutrient for the phytoplankton growth over about 30% of the global ocean. However, the nature of the external sources of iron to the ocean and their quantification remain uncertain. Among these external sources, the sediment sources have been recently shown to be underestimated. Besides, since the operationally defined dissolved iron (which is the sum of truly dissolved and colloidal iron) was traditionally assumed to be the only form available to phytoplankton and bacteria, most studies have focused on the supply of dissolved iron to the ocean, the role of the particulate fraction of iron being largely ignored. This traditional view has been recently challenged, noticeably, by observational evidences. Indeed, in situ observations have shown that large amounts of particulate iron are being resuspended from continental margins to the open ocean thanks to fine grained particles' transport over long distances. A fraction of this particulate iron may dissolve and thereby fuel the phytoplankton growth. The magnitude of the sedimentary sources of particulate iron and the releasing processes affecting this iron phase are not yet well constrained or quantified. As a consequence, the role of sedimentary particulate iron in the biogeochemical cycles is still unclear despite its potentially major widespread importance. Here, we propose a modeling exercise to assess the first order impacts of this newly considered particulate sedimentary iron on global ocean biogeochemistry. We designed global experiments with a coupled dynamical-biogeochemical model (NEMO-PISCES). First, a control simulation that includes only a sediment source of iron in the dissolved phase has been run. Then, this control simulation is being compared with simulations, in which we include a sediment source of iron in both phases (dissolved as well as particulate). Those latter simulations have been performed using a range of particulate iron dissolution rates (from published studies and laboratory experiment results) that will permit to test the sensitivity of the biogeochemical response.

  2. Leachable particulate iron in the Columbia River, estuary, and near-field plume

    NASA Astrophysics Data System (ADS)

    Lippiatt, Sherry M.; Brown, Matthew T.; Lohan, Maeve C.; Berger, Carolyn J. M.; Bruland, Kenneth W.

    2010-03-01

    This study examines the distribution of leachable particulate iron (Fe) in the Columbia River, estuary, and near-field plume. Surface samples were collected during late spring and summer of 2004-2006 as part of four River Influence on Shelf Ecosystems (RISE) cruises. Tidal amplitude and river flow are the primary factors influencing the estuary leachable particulate Fe concentrations, with greater values during high flow and/or spring tides. Near the mouth of the estuary, leachable particulate Fe [defined as the particulate Fe solubilized with a 25% acetic acid (pH 2) leach containing a weak reducing agent to reduce Fe oxyhydroxides and a short heating step to access intracellular Fe] averaged 770 nM during either spring tide or high flow, compared to 320 nM during neap tide, low flow conditions. In the near-field Columbia River plume, elevated leachable particulate Fe concentrations occur during spring tides and/or higher river flow, with resuspended shelf sediment as an additional source to the plume during periods of coastal upwelling and spring tides. Near-field plume concentrations of leachable particulate Fe (at a salinity of 20) averaged 660 nM during either spring tide or high flow, compared to 300 nM during neap tide, low flow conditions. Regardless of tidal amplitude and river flow, leachable particulate Fe concentrations in both the river/estuary and near-field plume are consistently one to two orders of magnitude greater than dissolved Fe concentrations. The Columbia River is an important source of reactive Fe to the productive coastal waters off Oregon and Washington, and leachable particulate Fe is available for solubilization following biological drawdown of the dissolved phase. Elevated leachable Fe concentrations allow coastal waters influenced by the Columbia River plume to remain Fe-replete and support phytoplankton production during the spring and summer seasons.

  3. Efficiency of Emission Control Measures on Particulate Matter-Related Health Impacts and Economic Cost during the 2014 Asia-Pacific Economic Cooperation Meeting in Beijing.

    PubMed

    Liu, Qichen; Huang, Jing; Guo, Bin; Guo, Xinbiao

    2016-12-28

    Background : The Asia-Pacific Economic Cooperation (APEC) meeting was held from 5 November to 11 November 2014 in Beijing, and comprehensive emission control measures were implemented. The efficiency of these measures on particulate matter-related health impacts and economic cost need to be evaluated. Methods : The influences of emission control measures during APEC on particulate matter were evaluated, and health economic effects were assessed. Results : Average concentrations of PM 2.5 and PM 10 during APEC were reduced by 57.0%, and 50.6% respectively, compared with pre-APEC period. However, the concentrations of particulate matter rebounded after APEC. Compared with the pre-APEC and post-APEC periods, the estimated number of deaths caused by non-accidental, cardiovascular and respiratory diseases that could be attributed to PM 2.5 and PM 10 during the APEC were the lowest. The economic cost associated with mortality caused by PM 2.5 and PM 10 during the APEC were reduced by (61.3% and 66.6%) and (50.3% and 60.8%) respectively, compared with pre-APEC and post-APEC. Conclusions : The emission control measures were effective in improving short term air quality and reducing health risks and medical expenses during 2014 APEC, but more efforts is needed for long term and continuous air quality improvement and health protection.

  4. Efficiency of Emission Control Measures on Particulate Matter-Related Health Impacts and Economic Cost during the 2014 Asia-Pacific Economic Cooperation Meeting in Beijing

    PubMed Central

    Liu, Qichen; Huang, Jing; Guo, Bin; Guo, Xinbiao

    2016-01-01

    Background: The Asia-Pacific Economic Cooperation (APEC) meeting was held from 5 November to 11 November 2014 in Beijing, and comprehensive emission control measures were implemented. The efficiency of these measures on particulate matter-related health impacts and economic cost need to be evaluated. Methods: The influences of emission control measures during APEC on particulate matter were evaluated, and health economic effects were assessed. Results: Average concentrations of PM2.5 and PM10 during APEC were reduced by 57.0%, and 50.6% respectively, compared with pre-APEC period. However, the concentrations of particulate matter rebounded after APEC. Compared with the pre-APEC and post-APEC periods, the estimated number of deaths caused by non-accidental, cardiovascular and respiratory diseases that could be attributed to PM2.5 and PM10 during the APEC were the lowest. The economic cost associated with mortality caused by PM2.5 and PM10 during the APEC were reduced by (61.3% and 66.6%) and (50.3% and 60.8%) respectively, compared with pre-APEC and post-APEC. Conclusions: The emission control measures were effective in improving short term air quality and reducing health risks and medical expenses during 2014 APEC, but more efforts is needed for long term and continuous air quality improvement and health protection. PMID:28036006

  5. Lexical Quality and Reading Comprehension in Primary School Children

    ERIC Educational Resources Information Center

    Richter, Tobias; Isberner, Maj-Britt; Naumann, Johannes; Neeb, Yvonne

    2013-01-01

    In a cross-sectional study, we examined the relationship between the quality of lexical representations and text comprehension skill in German primary school children (Grades 1-4). We measured the efficiency and accuracy of orthographical, phonological, and meaning representations by means of computerized tests. Text comprehension skill was…

  6. InMAP: a new model for air pollution interventions

    NASA Astrophysics Data System (ADS)

    Tessum, C. W.; Hill, J. D.; Marshall, J. D.

    2015-10-01

    Mechanistic air pollution models are essential tools in air quality management. Widespread use of such models is hindered, however, by the extensive expertise or computational resources needed to run most models. Here, we present InMAP (Intervention Model for Air Pollution), which offers an alternative to comprehensive air quality models for estimating the air pollution health impacts of emission reductions and other potential interventions. InMAP estimates annual-average changes in primary and secondary fine particle (PM2.5) concentrations - the air pollution outcome generally causing the largest monetized health damages - attributable to annual changes in precursor emissions. InMAP leverages pre-processed physical and chemical information from the output of a state-of-the-science chemical transport model (WRF-Chem) within an Eulerian modeling framework, to perform simulations that are several orders of magnitude less computationally intensive than comprehensive model simulations. InMAP uses a variable resolution grid that focuses on human exposures by employing higher spatial resolution in urban areas and lower spatial resolution in rural and remote locations and in the upper atmosphere; and by directly calculating steady-state, annual average concentrations. In comparisons run here, InMAP recreates WRF-Chem predictions of changes in total PM2.5 concentrations with population-weighted mean fractional error (MFE) and bias (MFB) < 10 % and population-weighted R2 ~ 0.99. Among individual PM2.5 species, the best predictive performance is for primary PM2.5 (MFE: 16 %; MFB: 13 %) and the worst predictive performance is for particulate nitrate (MFE: 119 %; MFB: 106 %). Potential uses of InMAP include studying exposure, health, and environmental justice impacts of potential shifts in emissions for annual-average PM2.5. Features planned for future model releases include a larger spatial domain, more temporal information, and the ability to predict ground-level ozone (O3) concentrations. The InMAP model source code and input data are freely available online.

  7. Deep ocean communities impacted by changing climate over 24 y in the abyssal northeast Pacific Ocean.

    PubMed

    Smith, Kenneth L; Ruhl, Henry A; Kahru, Mati; Huffard, Christine L; Sherman, Alana D

    2013-12-03

    The deep ocean, covering a vast expanse of the globe, relies almost exclusively on a food supply originating from primary production in surface waters. With well-documented warming of oceanic surface waters and conflicting reports of increasing and decreasing primary production trends, questions persist about how such changes impact deep ocean communities. A 24-y time-series study of sinking particulate organic carbon (food) supply and its utilization by the benthic community was conducted in the abyssal northeast Pacific (~4,000-m depth). Here we show that previous findings of food deficits are now punctuated by large episodic surpluses of particulate organic carbon reaching the sea floor, which meet utilization. Changing surface ocean conditions are translated to the deep ocean, where decadal peaks in supply, remineralization, and sequestration of organic carbon have broad implications for global carbon budget projections.

  8. Deep ocean communities impacted by changing climate over 24 y in the abyssal northeast Pacific Ocean

    PubMed Central

    Smith, Kenneth L.; Ruhl, Henry A.; Kahru, Mati; Huffard, Christine L.; Sherman, Alana D.

    2013-01-01

    The deep ocean, covering a vast expanse of the globe, relies almost exclusively on a food supply originating from primary production in surface waters. With well-documented warming of oceanic surface waters and conflicting reports of increasing and decreasing primary production trends, questions persist about how such changes impact deep ocean communities. A 24-y time-series study of sinking particulate organic carbon (food) supply and its utilization by the benthic community was conducted in the abyssal northeast Pacific (∼4,000-m depth). Here we show that previous findings of food deficits are now punctuated by large episodic surpluses of particulate organic carbon reaching the sea floor, which meet utilization. Changing surface ocean conditions are translated to the deep ocean, where decadal peaks in supply, remineralization, and sequestration of organic carbon have broad implications for global carbon budget projections. PMID:24218565

  9. Carbide/nitride grain refined rare earth-iron-boron permanent magnet and method of making

    DOEpatents

    McCallum, R.W.; Branagan, D.J.

    1996-01-23

    A method of making a permanent magnet is disclosed wherein (1) a melt is formed having a base alloy composition comprising RE, Fe and/or Co, and B (where RE is one or more rare earth elements) and (2) TR (where TR is a transition metal selected from at least one of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Al) and at least one of C and N are provided in the base alloy composition melt in substantially stoichiometric amounts to form a thermodynamically stable compound (e.g. TR carbide, nitride or carbonitride). The melt is rapidly solidified in a manner to form particulates having a substantially amorphous (metallic glass) structure and a dispersion of primary TRC, TRN and/or TRC/N precipitates. The amorphous particulates are heated above the crystallization temperature of the base alloy composition to nucleate and grow a hard magnetic phase to an optimum grain size and to form secondary TRC, TRN and/or TRC/N precipitates dispersed at grain boundaries. The crystallized particulates are consolidated at an elevated temperature to form a shape. During elevated temperature consolidation, the primary and secondary precipitates act to pin the grain boundaries and minimize deleterious grain growth that is harmful to magnetic properties. 33 figs.

  10. Carbide/nitride grain refined rare earth-iron-boron permanent magnet and method of making

    DOEpatents

    McCallum, R. William; Branagan, Daniel J.

    1996-01-23

    A method of making a permanent magnet wherein 1) a melt is formed having a base alloy composition comprising RE, Fe and/or Co, and B (where RE is one or more rare earth elements) and 2) TR (where TR is a transition metal selected from at least one of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Al) and at least one of C and N are provided in the base alloy composition melt in substantially stoichiometric amounts to form a thermodynamically stable compound (e.g. TR carbide, nitride or carbonitride). The melt is rapidly solidified in a manner to form particulates having a substantially amorphous (metallic glass) structure and a dispersion of primary TRC, TRN and/or TRC/N precipitates. The amorphous particulates are heated above the crystallization temperature of the base alloy composition to nucleate and grow a hard magnetic phase to an optimum grain size and to form secondary TRC, TRN and/or TRC/N precipitates dispersed at grain boundaries. The crystallized particulates are consolidated at an elevated temperature to form a shape. During elevated temperature consolidation, the primary and secondary precipitates act to pin the grain boundaries and minimize deleterious grain growth that is harmful to magnetic properties.

  11. Sources of fine organic aerosol. 2. Noncatalyst and catalyst-equipped automobiles and heavy-duty diesel trucks

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rogge, W.F.; Hildemann, L.M.; Mazurek, M.A.

    Gasoline- and diesel-powered vehicles are known to contribute appreciable amounts of inhalable fine particulate matter to the atmosphere in urban areas. Internal combustion engines burning gasoline and diesel fuel contribute more than 21% of the primary fine particulate organic carbon emitted to the Los Angeles atmosphere. In the present study, particulate (d[sub p] [le] 2 [mu]m) exhaust emissions from six noncatalyst automobiles, seven catalyst-equipped automobiles, and two heavy-duty diesel trucks are examined by gas chromatography/mass spectrometry. The purposes of this study are as follows: (a) to search for conservative marker compounds suitable for tracing the presence of vehicular particulate exhaustmore » emissions in the urban atmosphere, (b) to compile quantitative source profiles, and (c) to study the contributions of fine organic particulate vehicular exhaust to the Los Angeles atmosphere. More than 100 organic compounds are quantified, including n-alkanes, n-alkanoic acids, benzoic acids, benzaldehydes, PAH, oxy-PAH, steranes, pentacyclic triterpanes, azanaphthalenes, and others. Although fossil fuel markers such as steranes and pentacyclic triterpanes can be emitted from other sources, it can be shown that their ambient concentrations measured in the Los Angeles atmosphere are attributable mainly to vehicular exhaust emissions. 102 refs., 9 figs., 6 tabs.« less

  12. Global anthropogenic emissions of particulate matter including black carbon

    NASA Astrophysics Data System (ADS)

    Klimont, Zbigniew; Kupiainen, Kaarle; Heyes, Chris; Purohit, Pallav; Cofala, Janusz; Rafaj, Peter; Borken-Kleefeld, Jens; Schöpp, Wolfgang

    2017-07-01

    This paper presents a comprehensive assessment of historical (1990-2010) global anthropogenic particulate matter (PM) emissions including the consistent and harmonized calculation of mass-based size distribution (PM1, PM2. 5, PM10), as well as primary carbonaceous aerosols including black carbon (BC) and organic carbon (OC). The estimates were developed with the integrated assessment model GAINS, where source- and region-specific technology characteristics are explicitly included. This assessment includes a number of previously unaccounted or often misallocated emission sources, i.e. kerosene lamps, gas flaring, diesel generators, refuse burning; some of them were reported in the past for selected regions or in the context of a particular pollutant or sector but not included as part of a total estimate. Spatially, emissions were calculated for 172 source regions (as well as international shipping), presented for 25 global regions, and allocated to 0.5° × 0.5° longitude-latitude grids. No independent estimates of emissions from forest fires and savannah burning are provided and neither windblown dust nor unpaved roads emissions are included. We estimate that global emissions of PM have not changed significantly between 1990 and 2010, showing a strong decoupling from the global increase in energy consumption and, consequently, CO2 emissions, but there are significantly different regional trends, with a particularly strong increase in East Asia and Africa and a strong decline in Europe, North America, and the Pacific region. This in turn resulted in important changes in the spatial pattern of PM burden, e.g. European, North American, and Pacific contributions to global emissions dropped from nearly 30 % in 1990 to well below 15 % in 2010, while Asia's contribution grew from just over 50 % to nearly two-thirds of the global total in 2010. For all PM species considered, Asian sources represented over 60 % of the global anthropogenic total, and residential combustion was the most important sector, contributing about 60 % for BC and OC, 45 % for PM2. 5, and less than 40 % for PM10, where large combustion sources and industrial processes are equally important. Global anthropogenic emissions of BC were estimated at about 6.6 and 7.2 Tg in 2000 and 2010, respectively, and represent about 15 % of PM2. 5 but for some sources reach nearly 50 %, i.e. for the transport sector. Our global BC numbers are higher than previously published owing primarily to the inclusion of new sources. This PM estimate fills the gap in emission data and emission source characterization required in air quality and climate modelling studies and health impact assessments at a regional and global level, as it includes both carbonaceous and non-carbonaceous constituents of primary particulate matter emissions. The developed emission dataset has been used in several regional and global atmospheric transport and climate model simulations within the ECLIPSE (Evaluating the Climate and Air Quality Impacts of Short-Lived Pollutants) project and beyond, serves better parameterization of the global integrated assessment models with respect to representation of black carbon and organic carbon emissions, and built a basis for recently published global particulate number estimates.

  13. The Effect of Mississippi River Discharge on the Concentration and Composition of Particulate Matter along the Texas-Louisiana Shelf during Summers 2012 and 2013

    NASA Astrophysics Data System (ADS)

    Richardson, M. J.; Zuck, N.; Gardner, W. D.

    2016-02-01

    Flow from the Mississippi-Atchafalaya River System generally peaks during the spring freshet, discharging nutrient-rich fresh water and sediment into the northern Gulf of Mexico. The peak discharge varies year to year as a result of varying drought or flood conditions in the Mississippi watershed. When compared to an 8-year climatological average, summer 2012 is characterized by low discharge into the northern Gulf of Mexico, whereas summer 2013 is characterized by average discharge conditions. Water samples were collected during four cruises during June and August of 2012 and 2013 to assess the changes in concentration and composition of bulk particulate matter. While no consistent relationship between particulate matter composition and hypoxia was observed, there are several statistically significant seasonal and inter-annual changes in the concentration and composition of particulate matter associated with varying river discharge. There is also evidence that some sub-pycnocline turbidity and chlorophyll-a may be due to in situ primary productivity, rather than settled plankton containing chlorophyll-a.

  14. Characterization of a humic acid-like brown substance in airborne particulate matter and tentative identification of its origin

    NASA Astrophysics Data System (ADS)

    Mukai, Hitoshi; Ambe, Yoshinari

    A brown substance having the solubility characteristics of humic acid was extracted from airborne particulate matter sampled in a rural area of Japan. This brown substance contributed 0.6-3% of the total carbon in airborne particulate matter. This fraction also contained pollen protein in samples collected during the pollen season. Patterns of elution from gel permeation chromatography suggested a molecular weight range from 500 to 10,000, with a still higher upper limit for one sample. The infrared spectra were compared with those of humic acid from the local soil, extracts from dead leaves, smoke from burning plant matter, and soot from automotive exhaust, all possible sources of the brown substance. The closest similarity was with the extract smoke. This identification is strengthened by lack of correlation of the brown substance with aluminum, a tracer for soil content, and a value of K/Fe ratio in the associated particulate matter higher than any plausible source other than combustion. It is probable that the primary source of this brown, high molecular weight acidic materials is agricultural burning.

  15. Optimizing the milling characteristics of Al-SiC particulate composites

    NASA Astrophysics Data System (ADS)

    Karthikeyan, R.; Raghukandan, K.; Naagarazan, R. S.; Pai, B. C.

    2000-12-01

    The present investigation focuses on the face milling characteristics of LM25Al-SiC particulate composites produced through stir casting. Experiments were conducted according to an L27 orthogonal array and mathematical models were developed for such machining characteristics as flank wear, specific energy and surface roughness whose adequacy was checked. The insignificant effects present in the models were eliminated using a t-test. Goal programming was employed to optimize the cutting conditions by considering such primary objectives as maximizing the metal removal rate and minimizing tool wear, specific energy and surface roughness.

  16. Elucidating the mechanisms of nickel compound uptake: A review of particulate and nano-nickel endocytosis and toxicity

    PubMed Central

    Muñoz, Alexandra; Costa, Max

    2012-01-01

    Nickel (Ni) is a worldwide pollutant and contaminant that humans are exposed to through various avenues resulting in multiple toxic responses - most alarming is its clear carcinogenic nature. A variety of particulate Ni compounds persist in the environment and can be distinguished by characteristics such as solubility, structure, and surface charge. These characteristics influence cellular uptake and toxicity. Some particulate forms of Ni are carcinogenic and are directly and rapidly endocytized by cells. A series of studies conducted in the 1980’s observed this process, and we have reanalyzed the results of these studies to help elucidate the molecular mechanism of particulate Ni uptake. Originally the process of uptake observed was described as phagocytosis, however in the context of recent research we hypothesize that the process is macropinocytosis and/or clathrin mediated endocytosis. Primary considerations in determining the route of uptake here include calcium dependence, particle size, and inhibition through temperature and pharmacological approaches. Particle characteristics that influenced uptake include size, charge, surface characteristics, and structure. This discussion is relevant in the context of nanoparticle studies and the emerging interest in nano-nickel (nano-Ni), where toxicity assessments require a clear understanding of the parameters of particulate uptake and where establishment of such parameters is often obscured through inconsistencies across experimental systems. In this regard, this review aims to carefully document one system (particulate nickel compound uptake) and characterize its properties. PMID:22206756

  17. Elucidating the mechanisms of nickel compound uptake: A review of particulate and nano-nickel endocytosis and toxicity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Muñoz, Alexandra; Costa, Max, E-mail: Max.Costa@nyumc.org

    Nickel (Ni) is a worldwide pollutant and contaminant that humans are exposed to through various avenues resulting in multiple toxic responses — most alarming is its clear carcinogenic nature. A variety of particulate Ni compounds persist in the environment and can be distinguished by characteristics such as solubility, structure, and surface charge. These characteristics influence cellular uptake and toxicity. Some particulate forms of Ni are carcinogenic and are directly and rapidly endocytized by cells. A series of studies conducted in the 1980s observed this process, and we have reanalyzed the results of these studies to help elucidate the molecular mechanismmore » of particulate Ni uptake. Originally the process of uptake observed was described as phagocytosis, however in the context of recent research we hypothesize that the process is macropinocytosis and/or clathrin mediated endocytosis. Primary considerations in determining the route of uptake here include calcium dependence, particle size, and inhibition through temperature and pharmacological approaches. Particle characteristics that influenced uptake include size, charge, surface characteristics, and structure. This discussion is relevant in the context of nanoparticle studies and the emerging interest in nano-nickel (nano-Ni), where toxicity assessments require a clear understanding of the parameters of particulate uptake and where establishment of such parameters is often obscured through inconsistencies across experimental systems. In this regard, this review aims to carefully document one system (particulate nickel compound uptake) and characterize its properties.« less

  18. Primary School Text Comprehension Predicts Mathematical Word Problem-Solving Skills in Secondary School

    ERIC Educational Resources Information Center

    Björn, Piia Maria; Aunola, Kaisa; Nurmi, Jari-Erik

    2016-01-01

    This longitudinal study aimed to investigate the extent to which primary school text comprehension predicts mathematical word problem-solving skills in secondary school among Finnish students. The participants were 224 fourth graders (9-10 years old at the baseline). The children's text-reading fluency, text comprehension and basic calculation…

  19. Primary production export flux in Marguerite Bay (Antarctic Peninsula): Linking upper water-column production to sediment trap flux

    NASA Astrophysics Data System (ADS)

    Weston, Keith; Jickells, Timothy D.; Carson, Damien S.; Clarke, Andrew; Meredith, Michael P.; Brandon, Mark A.; Wallace, Margaret I.; Ussher, Simon J.; Hendry, Katharine R.

    2013-05-01

    A study was carried out to assess primary production and associated export flux in the coastal waters of the western Antarctic Peninsula at an oceanographic time-series site. New, i.e., exportable, primary production in the upper water-column was estimated in two ways; by nutrient deficit measurements, and by primary production rate measurements using separate 14C-labelled radioisotope and 15N-labelled stable isotope uptake incubations. The resulting average annual exportable primary production estimates at the time-series site from nutrient deficit and primary production rates were 13 and 16 mol C m-2, respectively. Regenerated primary production was measured using 15N-labelled ammonium and urea uptake, and was low throughout the sampling period. The exportable primary production measurements were compared with sediment trap flux measurements from 2 locations; the time-series site and at a site 40 km away in deeper water. Results showed ˜1% of the upper mixed layer exportable primary production was exported to traps at 200 m depth at the time-series site (total water column depth 520 m). The maximum particle flux rate to sediment traps at the deeper offshore site (total water column depth 820 m) was lower than the flux at the coastal time-series site. Flux of particulate organic carbon was similar throughout the spring-summer high flux period for both sites. Remineralisation of particulate organic matter predominantly occurred in the upper water-column (<200 m depth), with minimal remineralisation below 200 m, at both sites. This highly productive region on the Western Antarctic Peninsula is therefore best characterised as 'high recycling, low export'.

  20. ANALYSIS OF PARTICULATE BOUND NUTRIENTS IN URBAN STORMWATER

    EPA Science Inventory

    Nutrients are important players in the degradation of waterbodies because they are often the elements that limit primary productivity and, hence, are the key factors controlling eutrophication. Eutrophication causes unsightly algal blooms leading to oxygen depletion, stress on o...

  1. A BIOGENIC ROLE IN EXPOSURE TO TWO TOXIC COMPOUNDS

    EPA Science Inventory

    Biogenic sources play an important role in ozone and particulate concentrations through emissions of volatile organic compounds. The same emissions also contribute to chronic toxic exposures from formaldehyde and acetaldehyde because each compound arises through primary and se...

  2. Clean Air Act Second Prospective Report Study Science Advisory Board Review Teleconference, August 11, 2010

    EPA Pesticide Factsheets

    This technical memorandum provides a description of the Adjustment to the Primary Particulate Matter Emissions Estimates and the Modeled Attainment Test Software Analysis (MATS) Procedure for the 812 Second Prospective Analysis

  3. Comprehensive characterization of humic-like substances in smoke PM2.5 emitted from the combustion of biomass materials and fossil fuels

    NASA Astrophysics Data System (ADS)

    Fan, Xingjun; Wei, Siye; Zhu, Mengbo; Song, Jianzhong; Peng, Ping'an

    2016-10-01

    Humic-like substances (HULIS) in smoke fine particulate matter (PM2.5) emitted from the combustion of biomass materials (rice straw, corn straw, and pine branch) and fossil fuels (lignite coal and diesel fuel) were comprehensively studied in this work. The HULIS fractions were first isolated with a one-step solid-phase extraction method, and were then investigated with a series of analytical techniques: elemental analysis, total organic carbon analysis, UV-vis (ultraviolet-visible) spectroscopy, excitation-emission matrix (EEM) fluorescence spectroscopy, Fourier transform infrared spectroscopy, and 1H-nuclear magnetic resonance spectroscopy. The results show that HULIS account for 11.2-23.4 and 5.3 % of PM2.5 emitted from biomass burning (BB) and coal combustion, respectively. In addition, contributions of HULIS-C to total carbon and water-soluble carbon in smoke PM2.5 emitted from BB are 8.0-21.7 and 56.9-66.1 %, respectively. The corresponding contributions in smoke PM2.5 from coal combustion are 5.2 and 45.5 %, respectively. These results suggest that BB and coal combustion are both important sources of HULIS in atmospheric aerosols. However, HULIS in diesel soot only accounted for ˜ 0.8 % of the soot particles, suggesting that vehicular exhaust may not be a significant primary source of HULIS. Primary HULIS and atmospheric HULIS display many similar chemical characteristics, as indicated by the instrumental analytical characterization, while some distinct features were also apparent. A high spectral absorbance in the UV-vis spectra, a distinct band at λex/λem ≈ 280/350 nm in EEM spectra, lower H / C and O / C molar ratios, and a high content of [Ar-H] were observed for primary HULIS. These results suggest that primary HULIS contain more aromatic structures, and have a lower content of aliphatic and oxygen-containing groups than atmospheric HULIS. Among the four primary sources of HULIS, HULIS from BB had the highest O / C molar ratios (0.43-0.54) and [H-C-O] content (10-19 %), indicating that HULIS from this source mainly consisted of carbohydrate- and phenolic-like structures. HULIS from coal combustion had a lower O / C molar ratio (0.27) and a higher content of [Ar-H] (31 %), suggesting that aromatic compounds were extremely abundant in HULIS from this source. Moreover, the absorption Ångström exponents of primary HULIS from BB and coal combustion were 6.7-8.2 and 13.6, respectively. The mass absorption efficiencies of primary HULIS from BB and coal combustion at 365 nm (MAE365) were 0.97-2.09 and 0.63 m2 gC-1, respectively. Noticeably higher MAE365 values for primary HULIS from BB than coal combustion indicate that the former has a stronger contribution to the light-absorbing properties of aerosols in the atmospheric environment.

  4. School Environmental Intervention to Reduce Particulate Pollutant Exposures for Children with Asthma.

    PubMed

    Jhun, Iny; Gaffin, Jonathan M; Coull, Brent A; Huffaker, Michelle F; Petty, Carter R; Sheehan, William J; Baxi, Sachin N; Lai, Peggy S; Kang, Choong-Min; Wolfson, Jack M; Gold, Diane R; Koutrakis, Petros; Phipatanakul, Wanda

    Home-based interventions to improve indoor air quality have demonstrated benefits for asthma morbidity, yet little is known about the effect of environmental interventions in the school setting. We piloted the feasibility and effectiveness of a classroom-based air cleaner intervention to reduce particulate pollutants in classrooms of children with asthma. In this pilot randomized controlled trial, we assessed the effect of air cleaners on indoor air particulate pollutant concentrations in 18 classrooms (9 control, 9 intervention) in 3 urban elementary schools. We enrolled 25 children with asthma (13 control, 12 intervention) aged 6 to 10 years. Classroom air pollutant measurements and spirometry were completed once before and twice after randomization. Asthma symptoms were surveyed every 3 months. Baseline classroom levels of fine particulate matter (particulate matter with diameter of <2.5 μm [PM 2.5 ]) and black carbon (BC) were 6.3 and 0.41 μg/m 3 , respectively. When comparing the intervention to the control group, classroom PM 2.5 levels were reduced by 49% and 42% and BC levels were reduced by 58% and 55% in the first and second follow-up periods, respectively (P < .05 for all comparisons). When comparing the children randomized to intervention and control classrooms, there was a modest improvement in peak flow, but no significant changes in forced expiratory volume in 1 second (FEV 1 ) and asthma symptoms. In this pilot study, a classroom-based air cleaner intervention led to significant reductions in PM 2.5 and BC. Future large-scale studies should comprehensively evaluate the effect of school-based environmental interventions on pediatric asthma morbidity. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  5. The Effect of Text Types on Reading Comprehension

    ERIC Educational Resources Information Center

    Sahin, Ayfer

    2013-01-01

    Aim of this study is to determine the effect of narrative and informative text types on Reading Comprehension levels of Primary Education 4th and 5th grade students. Application was fulfilled in 2011-2012 academic year with 134 students in a primary education school in Province Kirsehir. Reading comprehension tests prepared according to text types…

  6. A SELF-CONSISTENT DEUTSCHIAN ESP MODEL

    EPA Science Inventory

    The report presents a new version of the EPA I Southern Research Institute electrostatic precipitator (ESP) model. The primary difference between this and the standard (Revision 3) versions is in the treatment of the particulate space charge. Both models apply the Deutsch equatio...

  7. EPA scientists develop Federal Reference & Equivalent Methods for measuring key air pollutants

    EPA Pesticide Factsheets

    EPA operates a nationwide air monitoring network to measure six primary air pollutants: carbon monoxide, lead, sulfur dioxide, ozone, nitrogen dioxide, and particulate matter as part of its mission to protect human health and the environment.

  8. New Federal Air Quality Standards.

    ERIC Educational Resources Information Center

    Stopinski, O. W.

    The report discusses the current procedures for establishing air quality standards, the bases for standards, and, finally, proposed and final National Primary and Secondary Ambient Air Quality Standards for sulfur dioxide, particulate matter, carbon monoxide, nonmethane hydrocarbons, photochemical oxidants, and nitrogen dioxide. (Author/RH)

  9. Present and Past Impact of Glacially Sourced Dust on Iron Fertilization of the Southern Ocean

    NASA Astrophysics Data System (ADS)

    Shoenfelt, E. M.; Winckler, G.; Kaplan, M. R.; Sambrotto, R.; Bostick, B. C.

    2016-12-01

    An increase in iron-containing dust flux and a more efficient biological pump in the Southern Ocean have been associated with the CO2 drawdown and global cooling of the Last Glacial Maximum (LGM). While iron (Fe) mineralogy is known to affect Fe bioavailability through its impact on Fe solubility, there are limited studies investigating the importance of Fe mineralogy in dust fluxes to the Southern Ocean, and no previous studies investigating interactions between eukaryotic phytoplankton and particulate-phase Fe in natural dusts applicable to Southern Ocean environments. Since physically weathered bedrock becomes less soluble as it becomes weathered and oxidized, we hypothesized that glacially sourced dusts would contain more Fe(II)-rich primary minerals and would be more bioavailable than dusts from areas not impacted by glaciers. We used a series of natural dusts from Patagonia as the sole Fe source in incubation experiments with the model diatom Phaeodactylum tricornutum, and evaluated Fe bioavailability using culture growth rates, cell density, and variable fluorescence. Monod curves were also used to evaluate the efficiency of the different particulates as sources of nutrient Fe. Using these Monod curves fit to growth rates plotted against particulate Fe concentrations, we observed that 1) Fe(II)-rich primary silicates were significantly more effective as an Fe source to diatoms than Fe(III)-rich oxides, that 2) Fe(II) content itself was responsible for the difference in Fe bioavailability/efficiency of the Fe nutrient source, and that 3) surface interactions with the particulates were important. In an effort to explore the possibility that Fe mineralogy impacted Fe bioavailability in past oceans, we will present our hypotheses regarding productivity and Fe mineralogy/bioavailability through the last glacial cycle.

  10. 2006 critical review - health effects of fine particulate air pollution: lines that connect

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    C. Arden Pope III; Douglas W. Dockery

    2006-06-15

    Efforts to understand and mitigate the health effects of particulate matter (PM) air pollution have a rich and interesting history. This review focuses on six substantial lines of research that have been pursued since 1997 that have helped elucidate our understanding about the effects of PM on human health. There has been substantial progress in the evaluation of PM health effects at different time-scales of exposure and in the exploration of the shape of the concentration-response function. There has also been emerging evidence of PM-related cardiovascular health effects and growing knowledge regarding interconnected general pathophysiological pathways that link PM exposuremore » with cardiopulmonary morbidity and mortality. Despite important gaps in scientific knowledge and continued reasons for some skepticism, a comprehensive evaluation of the research findings provides persuasive evidence that exposure to fine particulate air pollution has adverse effects on cardiopulmonary health. Although much of this research has been motivated by environmental public health policy, these results have important scientific, medical, and public health implications that are broader than debates over legally mandated air quality standards. 502 refs., 4 figs., 7 tabs.« less

  11. Emission characteristics and chemical components of size-segregated particulate matter in iron and steel industry

    NASA Astrophysics Data System (ADS)

    Jia, Jia; Cheng, Shuiyuan; Yao, Sen; Xu, Tiebing; Zhang, Tingting; Ma, Yuetao; Wang, Hongliang; Duan, Wenjiao

    2018-06-01

    As one of the highest energy consumption and pollution industries, the iron and steel industry is regarded as a most important source of particulate matter emission. In this study, chemical components of size-segregated particulate matters (PM) emitted from different manufacturing units in iron and steel industry were sampled by a comprehensive sampling system. Results showed that the average particle mass concentration was highest in sintering process, followed by puddling, steelmaking and then rolling processes. PM samples were divided into eight size fractions for testing the chemical components, SO42- and NH4+ distributed more into fine particles while most of the Ca2+ was concentrated in coarse particles, the size distribution of mineral elements depended on the raw materials applied. Moreover, local database with PM chemical source profiles of iron and steel industry were built and applied in CMAQ modeling for simulating SO42- and NO3- concentration, results showed that the accuracy of model simulation improved with local chemical source profiles compared to the SPECIATE database. The results gained from this study are expected to be helpful to understand the components of PM in iron and steel industry and contribute to the source apportionment researches.

  12. Global emissions of trace gases, particulate matter, and hazardous air pollutants from open burning of domestic waste.

    PubMed

    Wiedinmyer, Christine; Yokelson, Robert J; Gullett, Brian K

    2014-08-19

    The open burning of waste, whether at individual residences, businesses, or dump sites, is a large source of air pollutants. These emissions, however, are not included in many current emission inventories used for chemistry and climate modeling applications. This paper presents the first comprehensive and consistent estimates of the global emissions of greenhouse gases, particulate matter, reactive trace gases, and toxic compounds from open waste burning. Global emissions of CO2 from open waste burning are relatively small compared to total anthropogenic CO2; however, regional CO2 emissions, particularly in many developing countries in Asia and Africa, are substantial. Further, emissions of reactive trace gases and particulate matter from open waste burning are more significant on regional scales. For example, the emissions of PM10 from open domestic waste burning in China is equivalent to 22% of China's total reported anthropogenic PM10 emissions. The results of the emissions model presented here suggest that emissions of many air pollutants are significantly underestimated in current inventories because open waste burning is not included, consistent with studies that compare model results with available observations.

  13. The exposure assessment of airborne particulates matter (PM10 & PM2.5) towards building occupants: A case study at KL Sentral, Kuala Lumpur, Malaysia

    NASA Astrophysics Data System (ADS)

    Mohddin, S. A.; Aminuddin, N. M.

    2014-02-01

    Airborne particulates have been recognized as a crucial pollutant of indoor air. These pollutants can contribute towards poor indoor air quality (IAQ), which may affect human health in immediate or long term. This study aims to determine the level of IAQ and the effects of particulate towards occupants of office buildings (the office buildings selected for the case study are SSM, KTMB and MRCB at KL Sentral). The objectives of study are (i) to measure the level of airborne particulates that contribute to the IAQ during working hours, (ii) to compare the level of airborne particulates with the existing guidelines and standards of IAQ in Malaysia and other Asian countries and (iii) to assess the symptoms associated with airborne particulates among the building occupants, which were achieved through primary data collection (case study or site survey, structured interview and questionnaire survey) and supported by literature reviews. The results showed that the mass concentration level of airborne particulates within the areas has exceeded the allowable limit of 0.15mg/m3 by IAQ Code of Practice, 2005 of the Department of Safety and Health (DOSH), Malaysia and 0.05mg/m3 by the Department of Environmental (DOE) (outdoor) of 8 hours continuous sampling. Based on the findings, the highest mass concentration values measured is 2.581 mg/m3 at lobby of SSM building which is the highest recorded 17 times higher from the maximum limit recommended by DOSH than the others. This is due to the nearby construction works and the high numbers of particulates are generated from various types of vehicles for transportation surrounding KL Sentral. Therefore, the development of Malaysian Ambient Air Quality Guidelines on PM2.5 as one of the crucial parameters is highly recommended.

  14. Fossil and non-fossil source contributions to atmospheric carbonaceous aerosols during extreme spring grassland fires in Eastern Europe

    NASA Astrophysics Data System (ADS)

    Ulevicius, V.; Byčenkienė, S.; Bozzetti, C.; Vlachou, A.; Plauškaitė, K.; Mordas, G.; Dudoitis, V.; Abbaszade, G.; Remeikis, V.; Garbaras, A.; Masalaite, A.; Blees, J.; Fröhlich, R.; Dällenbach, K. R.; Canonaco, F.; Slowik, J. G.; Dommen, J.; Zimmermann, R.; Schnelle-Kreis, J.; Salazar, G. A.; Agrios, K.; Szidat, S.; El Haddad, I.; Prévôt, A. S. H.

    2015-09-01

    In early spring the Baltic region is frequently affected by high pollution events due to biomass burning in that area. Here we present a comprehensive study to investigate the impact of biomass/grass burning (BB) on the evolution and composition of aerosol in Preila, Lithuania, during springtime open fires. Non-refractory submicron particulate matter (NR-PM1) was measured by an Aerodyne aerosol chemical speciation monitor (ACSM) and a source apportionment with the multilinear engine (ME-2) running the positive matrix factorization (PMF) model was applied to the organic aerosol fraction to investigate the impact of biomass/grass burning. Satellite observations over regions of biomass burning activity supported the results and identification of air mass transport to the area of investigation. Sharp increases in biomass burning tracers, such as levoglucosan up to 683 ng m-3 and black carbon (BC) up to 17 μg m-3 were observed during this period. A further separation between fossil and non-fossil primary and secondary contributions was obtained by coupling ACSM PMF results and radiocarbon (14C) measurements of the elemental (EC) and organic (OC) carbon fractions. Non-fossil organic carbon (OCnf) was the dominant fraction of PM1, with the primary (POCnf) and secondary (SOCnf) fractions contributing 26-44 % and 13-23 % to the TC, respectively. 5-8 % of the TC had a primary fossil origin (POCf), whereas the contribution of fossil secondary organic carbon (SOCf) was 4-13 %. Non-fossil EC (ECnf) and fossil EC (ECf) ranged from 13-24 % and 7-12 %, respectively. Isotope ratio of stable carbon and nitrogen isotopes were used to distinguish aerosol particles associated with solid and liquid fossil fuel burning.

  15. Fossil and non-fossil source contributions to atmospheric carbonaceous aerosols during extreme spring grassland fires in Eastern Europe

    NASA Astrophysics Data System (ADS)

    Ulevicius, Vidmantas; Byčenkienė, Steigvilė; Bozzetti, Carlo; Vlachou, Athanasia; Plauškaitė, Kristina; Mordas, Genrik; Dudoitis, Vadimas; Abbaszade, Gülcin; Remeikis, Vidmantas; Garbaras, Andrius; Masalaite, Agne; Blees, Jan; Fröhlich, Roman; Dällenbach, Kaspar R.; Canonaco, Francesco; Slowik, Jay G.; Dommen, Josef; Zimmermann, Ralf; Schnelle-Kreis, Jürgen; Salazar, Gary A.; Agrios, Konstantinos; Szidat, Sönke; El Haddad, Imad; Prévôt, André S. H.

    2016-05-01

    In early spring the Baltic region is frequently affected by high-pollution events due to biomass burning in that area. Here we present a comprehensive study to investigate the impact of biomass/grass burning (BB) on the evolution and composition of aerosol in Preila, Lithuania, during springtime open fires. Non-refractory submicron particulate matter (NR-PM1) was measured by an Aerodyne aerosol chemical speciation monitor (ACSM) and a source apportionment with the multilinear engine (ME-2) running the positive matrix factorization (PMF) model was applied to the organic aerosol fraction to investigate the impact of biomass/grass burning. Satellite observations over regions of biomass burning activity supported the results and identification of air mass transport to the area of investigation. Sharp increases in biomass burning tracers, such as levoglucosan up to 683 ng m-3 and black carbon (BC) up to 17 µg m-3 were observed during this period. A further separation between fossil and non-fossil primary and secondary contributions was obtained by coupling ACSM PMF results and radiocarbon (14C) measurements of the elemental (EC) and organic (OC) carbon fractions. Non-fossil organic carbon (OCnf) was the dominant fraction of PM1, with the primary (POCnf) and secondary (SOCnf) fractions contributing 26-44 % and 13-23 % to the total carbon (TC), respectively. 5-8 % of the TC had a primary fossil origin (POCf), whereas the contribution of fossil secondary organic carbon (SOCf) was 4-13 %. Non-fossil EC (ECnf) and fossil EC (ECf) ranged from 13-24 and 7-13 %, respectively. Isotope ratios of stable carbon and nitrogen isotopes were used to distinguish aerosol particles associated with solid and liquid fossil fuel burning.

  16. Variability of Ambient Aerosol in the Mexico City Metropolian Area

    NASA Astrophysics Data System (ADS)

    Onasch, T. B.; Worsnop, D. R.; Canagaratna, M.; Jayne, J. T.; Herndon, S.; Mortimer, P.; Kolb, C. E.; Rogers, T.; Knighton, B.; Dunlea, E.; Marr, L.; de Foy, B.; Molina, M.; Molina, L.; Salcedo, D.; Dzepina, K.; Jimenez, J. L.

    2004-12-01

    The spatial and temporal variations of the ambient aerosol in the Mexico City Metropolitan area was characterized during the springs of 2002 and 2003 using a mobile laboratory equipped with gas and particulate measurement instrumentation. The laboratory was operated at various fixed sites locations in and at the edge of the metropolitan area (Xalostoc, Merced, Cenica, Pedregal, and Santa Ana). Size-resolved aerosol mass and chemical composition was measured with an aerosol mass spectrometer and selected trace gas species (low mass organic compounds, NO, NO2, NOy, O3, SO2, CH2O, NH3, CO2) were measured using a proton transfer reaction mass spectrometer and various optical systems. The aerosol was predominantly organic in composition with lesser amounts of ammonium nitrate, sulfate, and chloride. The organic component was composed of mixed primary and secondary organic compounds. The mass loading and chemical composition of the aerosol was influenced by local and regional air pollution sources and the meteorology in Mexico City. Most urban sites were influenced by a strong diurnal particulate mass trend indicative of primary organic emissions from traffic during early morning and subsequently oxidized/processed organics and ammonium nitrate particles starting in the mid-morning (~9 AM) and continuing throughout the day. Morning traffic-related primary organic emissions were strongest at La Merced (center of Mexico City, located near a busy food market), more subdued at other fixed sites further from the city center, and varied depending upon the day of week and holiday schedules. Particle-bound polycyclic aromatic hydrocarbons were observed within Mexico City fixed sites and were correlated with traffic organic PM emissions. Oxidized organic and ammonium nitrate events occurred during mid-morning at all city sites and were well correlated with gas phase photochemical activity. The daily ammonium nitrate aerosol event occurred later at sites near the city limits, likely due to transported emissions from the city center. The sulfate particulate mass measured throughout most of the Mexico City area did not show a consistent diurnal pattern, characteristic of aged regional aerosol. Local refuse burns were observed to be a source of inorganic particulate chloride.

  17. An Evaluation of Two Approaches for Teaching Reading Comprehension Strategies in the Primary Years Using Science Information Texts

    ERIC Educational Resources Information Center

    Reutzel, D. Ray; Smith, John A.; Fawson, Parker C.

    2005-01-01

    There are few research studies on the effects of teaching comprehension strategies to young children in the primary grades. Using a Dominant-Less Dominant Mixed Model design employing both qualitative and quantitative data collection, we evaluated two approaches for teaching comprehension strategies to 7- and 8-year-old children in four…

  18. Environmental assessment of a watertube boiler firing a coal-water slurry. Volume 1. Technical results. Final report, January 1984-March 1985

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    DeRosier, R.; Waterland, L.R.

    1986-02-01

    The report describes results from field testing a watertube industrial boiler firing a coal/water slurry (CWS) containing about 60% coal. Emission measurements included continuous monitoring of flue-gas emissions; source assessment sampling system (SASS) sampling of the flue-gas, with subsequent analysis of samples to obtain total flue-gas organics in two boiling point ranges, compound category information within these ranges, specific quantitation of the semivolatile organic priority pollutants, and flue-gas concentrations of 73 trace elements: EPA Methods 5/8 sampling for particulate, SO/sub 2/, and SO/sub 3/ emissions; and grab sampling of fuel and ash for inorganic composition. NOx, SO/sub 2/, CO, andmore » TUHC emissions were in the 230-310, 880-960, 170-200, and 1-3 ppm ranges (corrected to 3% 02), respectively, over the two tests performed. Particulate levels at the boiler outlet (upstream of the unit's baghouse) were 7.3 g/dscm in the comprehensive test. Coarse particulate (>3 micrometers) predominated. Total organic emissions were almost 50 mg/dscm, with about 70% of the organic matter in the nonvolatile (>300 C) boiling point range. The bottom ash organic content was 8 mg/g, 80% of which was in the nonvolatile range. Of the PAHs, only naphthalene was detected in the flue gas particulate, with emission levels of 8.6 micrograms/dscm. Several PAHs were found in the bottom ash.« less

  19. The mouse lymphoma thymidine kinase assay for the assessment and comparison of the mutagenic activity of cigarette mainstream smoke particulate phase.

    PubMed

    Schramke, H; Meisgen, T J; Tewes, F J; Gomm, W; Roemer, E

    2006-10-29

    The mouse lymphoma thymidine kinase assay (MLA) has been optimized to quantitatively determine the in vitro mutagenicity of cigarette mainstream smoke particulate phase. To test whether the MLA is able to discriminate between different cigarette types, specially constructed cigarettes each containing a single tobacco type - Bright, Burley, or Oriental - were investigated. The mutagenic activity of the Burley cigarette was statistically significantly lower, up to approximately 40%, than that of the Bright and Oriental cigarettes. To determine the impact of two different sets of smoking conditions, American-blend cigarettes were smoked under US Federal Trade Commission/International Organisation for Standardisation conditions and under Massachusetts Department of Public Health (MDPH) conditions. Conventional cigarettes - eight from the US commercial market plus the Reference Cigarettes 1R4F and 2R4F - and an electrically heated cigarette smoking system (EHCSS) prototype were tested. There were no statistically significant differences between the two sets of smoking conditions on a per mg total particulate matter basis, although there was a consistent trend towards slightly lower mutagenic activity under MDPH conditions. The mutagenic activity of the EHCSS prototype was distinctly lower than that of the conventional cigarettes under both sets of smoking conditions. These results show that the MLA can be used to assess and compare the mutagenic activity of cigarette mainstream smoke particulate phase in the comprehensive toxicological assessment of cigarette smoke.

  20. A32A-0126: A BIOGENIC ROLE IN EXPOSURE TO TWO TOXIC COMPOUNDS

    EPA Science Inventory

    Biogenic sources play an important role in ozone and particulate concentrations through emissions of volatile organic compounds. The same emissions also contribute to chronic toxic exposures from formaldehyde and acetaldehyde because each compound arises through primary and sec...

  1. VASCULAR RESPONSE TO TRAFFIC-DERIVED INHALATION IN HUMANS

    EPA Science Inventory

    By coordinating closely with Center Projects 1-3, we will determine whether specific aspects of traffic-derived exposure (primary vs. secondary organics, particulate vs. gases, spark-ignition vs. diesel engine vs. a mixture) enhance the human vascular response to pollutants. W...

  2. Measurement of gas and particulate amines at a dairy operation

    USDA-ARS?s Scientific Manuscript database

    Agricultural facilities are a source of particles and gases that can exhibit influences on air quality. Particle mass concentration influences from agricultural sources can include both primary emissions and secondary particle formation through the emission of gaseous precursors. Reports showing ami...

  3. [Association between particulate matter from biomass burning and respiratory diseases in the southern region of the Brazilian Amazon].

    PubMed

    do Carmo, Cleber Nascimento; Hacon, Sandra; Longo, Karla Maria; Freitas, Saulo; Ignotti, Eliane; Ponce de Leon, Antonio; Artaxo, Paulo

    2010-01-01

    To investigate the short-term effects of exposure to particulate matter from biomass burning in the Amazon on the daily demand for outpatient care due to respiratory diseases in children and the elderly. Epidemiologic study with ecologic time series design. Daily consultation records were obtained from the 14 primary health care clinics in the municipality of Alta Floresta, state of Mato Grosso, in the southern region of the Brazilian Amazon, between January 2004 and December 2005. Information on the daily levels of fine particulate matter was made available by the Brazilian National Institute for Spatial Research. To control for confounding factors (situations in which a non-causal association between exposure and disease is observed due to a third variable), variables related to time trends, seasonality, temperature, relative humidity, rainfall, and calendar effects (such as occurrence of holidays and weekends) were included in the model. Poisson regression with generalized additive models was used. A 10 microg/m3 increase in the level of exposure to particulate matter was associated with increases of 2.9% and 2.6% in outpatient consultations due to respiratory diseases in children on the 6th and 7th days following exposure. Significant associations were not observed for elderly individuals. The results suggest that the levels of particulate matter from biomass burning in the Amazon are associated with adverse effects on the respiratory health of children.

  4. Using Primary Language Support via Computer to Improve Reading Comprehension Skills of First-Grade English Language Learners

    ERIC Educational Resources Information Center

    Rodriguez, Cathi Draper; Filler, John; Higgins, Kyle

    2012-01-01

    Through this exploratory study the authors investigated the effects of primary language support delivered via computer on the English reading comprehension skills of English language learners. Participants were 28 First-grade students identified as Limited English Proficient. The primary language of all participants was Spanish. Students were…

  5. Electron microscopic study of soot particulate matter emissions from aircraft turbine engines.

    PubMed

    Liati, Anthi; Brem, Benjamin T; Durdina, Lukas; Vögtli, Melanie; Dasilva, Yadira Arroyo Rojas; Eggenschwiler, Panayotis Dimopoulos; Wang, Jing

    2014-09-16

    The microscopic characteristics of soot particulate matter (PM) in gas turbine exhaust are critical for an accurate assessment of the potential impacts of the aviation industry on the environment and human health. The morphology and internal structure of soot particles emitted from a CFM 56-7B26/3 turbofan engine were analyzed in an electron microscopic study, down to the nanoscale, for ∼ 100%, ∼ 65%, and ∼ 7% static engine thrust as a proxy for takeoff, cruising, and taxiing, respectively. Sampling was performed directly on transmission electron microscopy (TEM) grids with a state-of-the-art sampling system designed for nonvolatile particulate matter. The electron microscopy results reveal that ∼ 100% thrust produces the highest amount of soot, the highest soot particle volume, and the largest and most crystalline primary soot particles with the lowest oxidative reactivity. The opposite is the case for soot produced during taxiing, where primary soot particles are smallest and most reactive and the soot amount and volume are lowest. The microscopic characteristics of cruising condition soot resemble the ones of the ∼ 100% thrust conditions, but they are more moderate. Real time online measurements of number and mass concentration show also a clear correlation with engine thrust level, comparable with the TEM study. The results of the present work, in particular the small size of primary soot particles present in the exhaust (modes of 24, 20, and 13 nm in diameter for ∼ 100%, ∼ 65% and ∼ 7% engine thrust, respectively) could be a concern for human health and the environment and merit further study. This work further emphasizes the significance of the detailed morphological characteristics of soot for assessing environmental impacts.

  6. Effect of selective catalytic reduction (SCR) on fine particle emission from two coal-fired power plants in China

    NASA Astrophysics Data System (ADS)

    Li, Zhen; Jiang, Jingkun; Ma, Zizhen; Wang, Shuxiao; Duan, Lei

    2015-11-01

    Nitrogen oxides (NOx) emission abatement of coal-fired power plants (CFPPs) requires large-scaled installation of selective catalytic reduction (SCR), which would reduce secondary fine particulate matter (PM2.5) (by reducing nitrate aerosol) in the atmosphere. However, our field measurement of two CFPPs equipped with SCR indicates a significant increase of SO42- and NH4+ emission in primary PM2.5, due to catalytic enhancement of SO2 oxidation to SO3 and introducing of NH3 as reducing agent. The subsequent formation of (NH4)2SO4 or NH4HSO4 aerosol is commonly concentrated in sub-micrometer particulate matter (PM1) with a bimodal pattern. The measurement at the inlet of stack also showed doubled primary PM2.5 emission by SCR operation. This effect should therefore be considered when updating emission inventory of CFPPs. By rough estimation, the enhanced primary PM2.5 emission from CFPPs by SCR operation would offset 12% of the ambient PM2.5 concentration reduction in cities as the benefit of national NOx emission abatement, which should draw attention of policy-makers for air pollution control.

  7. Quenching of Particle-Gas Combustible Mixtures Using Electric Particulate Suspension (EPS) and Dispersion Methods

    NASA Technical Reports Server (NTRS)

    Colver, Gerald M.; Goroshin, Samuel; Lee, John H. S.

    2001-01-01

    A cooperative study is being carried out between Iowa State University and McGill University. The new study concerns wall and particle quenching effects in particle-gas mixtures. The primary objective is to measure and interpret flame quenching distances, flammability limits, and burning velocities in particulate suspensions. A secondary objective is to measure particle slip velocities and particle velocity distribution as these influence flame propagation. Two suspension techniques will be utilized and compared: (1) electric particle suspension/EPS; and (2) flow dispersion. Microgravity tests will permit testing of larger particles and higher and more uniform dust concentrations than is possible in normal gravity.

  8. Gravimetric measurement of momentary drying rate of spray freeze-dried powders in vials.

    PubMed

    Gieseler, Henning; Lee, Geoffrey

    2009-09-01

    The profile of drying rate versus primary drying time for a spray freeze-dried trehalose aqueous solution is much different from that determined for regular freeze-drying. Drying rate declines very rapidly, attributed to rate-limiting heat transfer through the packed bed of frozen microparticles contained in a vial. The inter-particulate spaces appear to be the cause of this rate limitation. Use of either liquid nitrogen or liquid propane as a cryogenic produced strong differences in both SFD particle morphology and drying rate using trehalose, sucrose, or mannitol. The lack of any evident correlation supports the argument that the inter-particulate voids determine drying behavior.

  9. Characterization of the Particulate Emissions from the BP ...

    EPA Pesticide Factsheets

    Opportunistic particle samples were gathered from the sail of a tethered aerostat during at-sea plume sampling of the purposely-burned surface oil during the BP Deepwater Horizon disaster in the Gulf of Mexico. Particles were analyzed for polycyclic aromatic hydrocarbons (PAHs), organic carbon (OC), elemental carbon (EC), metals, and polychlorinated dibenzodioxins/dibenzofurans (PCDDs/PCDFs). Emission factors were calculated using previous sampling values of background-adjusted CO2 and particulate matter (PM)-bound C. The mean of five thermal-optical analyses indicated that the burned crude oil particulate matter was 93% carbon (w/w) with the predominance being refractory elemental carbon (82% w/w) on average. PAHs accounted for roughly 60 ug/g of the PM mass or 4.5 mg/kg oil burned, at least an order of magnitude less than earlier laboratory based studies. Microscopy indicates that the soot from the in situ oil burns is distinct from more common soot by its aggregate size, primary particle size, and nanostructure within the primary particles. The PCDD/PCDF concentration of the PM was 1.5 to 3.3 ng toxic equivalency (TEQ)/kg PM sampled, about 10-fold lower than from a previous dedicated gas/solid sample, indicating loss of small particle-bound and more volatile PCDD/PCDF congeners through the aerostat sail. This work presents an analysis of smoke particles opportunistically caught during the in situ surface oil burns during the 2010 BP Deepwater Horizon di

  10. Ocean Color Data at the Goddard DAAC

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The apparent color of the ocean is determined by the interactions of incident light with substances or particles present in the water. The most significant constituents are free-floating photosynthetic organisms (phytoplankton) and inorganic particulates. Phytoplankton contain chlorophyll, which absorbs light at blue and red wavelengths and transmits in the green. Particulate matter can reflect and absorb light, which reduces the clarity (light transmission) of the water. Substances dissolved in water can also affect its color. Observations of ocean color from space, utilizing sensors specially designed to detect the small amount of light radiating from the sea surface, provide a global picture of the patterns of biological productivity in the world's oceans. For that reason, ocean color remote sensing data is a vital resource for biological oceanography. Unlike the limited area of the ocean that can be investigated from a research ship, data from a satellite sensor covers a large region and provides a comprehensive view of the marine environment.

  11. Air pollution and cardiovascular disease: a statement for healthcare professionals from the Expert Panel on Population and Prevention Science of the American Heart Association.

    PubMed

    Brook, Robert D; Franklin, Barry; Cascio, Wayne; Hong, Yuling; Howard, George; Lipsett, Michael; Luepker, Russell; Mittleman, Murray; Samet, Jonathan; Smith, Sidney C; Tager, Ira

    2004-06-01

    Air pollution is a heterogeneous, complex mixture of gases, liquids, and particulate matter. Epidemiological studies have demonstrated a consistent increased risk for cardiovascular events in relation to both short- and long-term exposure to present-day concentrations of ambient particulate matter. Several plausible mechanistic pathways have been described, including enhanced coagulation/thrombosis, a propensity for arrhythmias, acute arterial vasoconstriction, systemic inflammatory responses, and the chronic promotion of atherosclerosis. The purpose of this statement is to provide healthcare professionals and regulatory agencies with a comprehensive review of the literature on air pollution and cardiovascular disease. In addition, the implications of these findings in relation to public health and regulatory policies are addressed. Practical recommendations for healthcare providers and their patients are outlined. In the final section, suggestions for future research are made to address a number of remaining scientific questions.

  12. Effects of vibratory microscreening on proximate composition and recovery of poultry processing wastewater particulate matter.

    PubMed

    Kiepper, B H; Merka, W C; Fletcher, D L

    2008-12-01

    Experiments were conducted to compare the effects of tertiary microscreen gap size on the proximate composition and rate of recovery of particulate matter from poultry processing wastewater (PPW). A high-speed vibratory screen was installed within the wastewater treatment area of a southeast US broiler slaughter plant after the existing primary and secondary mechanical rotary screens. Microscreen panels with nominal gap size openings of 212, 106 and 45mum were investigated. The particulate matter samples recovered were subjected to proximate analysis to determine percent moisture, fat, protein, crude fiber and ash. The average percent wet weight moisture (%WW) content for all samples was 79.1. The average percent dry matter (%DM) fat, protein, crude fiber and ash were 63.5, 17.5, 4.8 and 1.5, respectively. The mean concentration of total solids (TS) recovered from all microscreen runs was 668mg/L, which represents a potential additional daily offal recovery rate of 12.1metric tons (MT) per 3.78 million L (1.0 million gallons US) of PPW. There was no significant difference in the performance of the three microscreen gap sizes with regard to proximate composition or mass of particulate matter recovered.

  13. Tracing carbonaceous sources by using particulate carbon and sulfate in precipitation in Calgary, Alberta Canada

    NASA Astrophysics Data System (ADS)

    Ge, C.; Stenhouse, K. J.; Du, K.; Xing, Z.; Norman, A. L.

    2016-12-01

    Carbonaceous matter is often the dominant contributor to Particulate Matter (PM) which has a significant influence on climate, air quality and human health. The measurement of particulate carbon in rainfall in Calgary, Alberta has not been studied. This study reports the sulfate and the first concentrations of particulate carbon (PC) in rainfall in Calgary. It traces seasonal carbonaceous sources for the purpose of understanding sources for air quality control. Precipitation samples are collected twice a day at the University of Calgary. Thermo-optical methods are used to analyze concentrations of PC, including elemental carbon (EC), primary organic carbon (POC) and secondary organic carbon (SOC). Sulfate concentrations are measured using ion chromatography. In this study, sources from long range transport and local emissions are examined. We emphasized the apportionment of OC/EC in oil and gas emissions and diurnal variations in transportation emissions. Weekly average data for dry deposition were calculated to estimate the scavenging ratio of EC/POC/SOC and ions in precipitation. The results of this study will be presented with an emphasis on the relationship of carbonaceous material and sulfate. A range of apportionment methods have been applied to examine limitations in quantifying SOC in fall.

  14. Distribution of trace metals (Cu, Pb, Ni, Zn) between particulate, colloidal and truly dissolved fractions in wastewater treatment.

    PubMed

    Hargreaves, Andrew J; Vale, Peter; Whelan, Jonathan; Constantino, Carlos; Dotro, Gabriela; Campo, Pablo; Cartmell, Elise

    2017-05-01

    The distribution of Cu, Pb, Ni and Zn between particulate, colloidal and truly dissolved size fractions in wastewater from a trickling filter treatment plant was investigated. Samples of influent, primary effluent, humus effluent, final effluent and sludge holding tank returns were collected and separated into particulate (i.e. > 0.45 μm), colloidal (i.e. 1 kDa to 0.45 μm), and truly dissolved (i.e. < 1 kDa) fractions using membrane filters. In the influent, substantial proportions of Cu (60%), Pb (67%), and Zn (32%) were present in the particulate fraction which was removed in conjunction with suspended particles at the works in subsequent treatment stages. In final effluent, sizeable proportions of Cu (52%), Pb (32%), Ni (44%) and Zn (68%) were found within the colloidal size fraction. Calculated ratios of soluble metal to organic carbon suggest the metal to be adsorbed to or complexed with non-humic macromolecules typically found within the colloidal size range. These findings suggest that technologies capable of removing particles within the colloidal fraction have good potential to enhance metals removal from wastewater. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. RECRUITING AND RETAINING PARTICIPANTS FOR AN EXPOSURE STUDY IN SOUTHEAST RALEIGH

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) recently completed a study of African-Americans' exposure to particulate matter (PM) in Southeast Raleigh. A primary goal was to compare PM levels measured at ambient and residential sites with those from personal exposure monitors...

  16. PHOTOCHEMICAL AND AEROSOL MODELING WITH THE CMAQ PLUME-IN-GRID APPROACH

    EPA Science Inventory

    Emissions of nitrogen oxides (NO) and/or sulfur oxides (SO) from individual point sources, such as coal-fired power plants, with tall stacks contribute to reduced air quality. These primary species are important precursors of various oxidant species and secondary fine particul...

  17. Effect of Drive Cycle and Gasoline Particulate Filter on the Size and Morphology of Soot Particles Emitted from a Gasoline-Direct-Injection Vehicle.

    PubMed

    Saffaripour, Meghdad; Chan, Tak W; Liu, Fengshan; Thomson, Kevin A; Smallwood, Gregory J; Kubsh, Joseph; Brezny, Rasto

    2015-10-06

    The size and morphology of particulate matter emitted from a light-duty gasoline-direct-injection (GDI) vehicle, over the FTP-75 and US06 transient drive cycles, have been characterized by transmission-electron-microscope (TEM) image analysis. To investigate the impact of gasoline particulate filters on particulate-matter emission, the results for the stock-GDI vehicle, that is, the vehicle in its original configuration, have been compared to the results for the same vehicle equipped with a catalyzed gasoline particulate filter (GPF). The stock-GDI vehicle emits graphitized fractal-like aggregates over all driving conditions. The mean projected area-equivalent diameter of these aggregates is in the 78.4-88.4 nm range and the mean diameter of primary particles varies between 24.6 and 26.6 nm. Post-GPF particles emitted over the US06 cycle appear to have an amorphous structure, and a large number of nucleation-mode particles, depicted as low-contrast ultrafine droplets, are observed in TEM images. This indicates the emission of a substantial amount of semivolatile material during the US06 cycle, most likely generated by the incomplete combustion of accumulated soot in the GPF during regeneration. The size of primary particles and soot aggregates does not vary significantly by implementing the GPF over the FTP-75 cycle; however, particles emitted by the GPF-equipped vehicle over the US06 cycle are about 20% larger than those emitted by the stock-GDI vehicle. This may be attributed to condensation of large amounts of organic material on soot aggregates. High-contrast spots, most likely solid nonvolatile cores, are observed within many of the nucleation-mode particles emitted over the US06 cycle by the GPF-equipped vehicle. These cores are either generated inside the engine or depict incipient soot particles which are partially carbonized in the exhaust line. The effect of drive cycle and the GPF on the fractal parameters of particles, such as fractal dimension and fractal prefactor, is insignificant.

  18. Comprehensive Monitoring Program, Final Air Quality Data Assessment Report for 1989, Version 2.1. Volume 4

    DTIC Science & Technology

    1990-06-01

    8.3U 11.94 23.4 214.71 6 6 36.9 17.54 4 I U SFM6 DATA LSTM i SIGA SA AX "DAR OR 03 CO S02 NO N02 NOX U S D THUA TEN PRE$ PRECIP RAD RH WS STAB S115...Hodgson, 1974: Predicted dry deposition velocities. Atmospheric-Surface Exchange of Particulate and Gaseous Pollutants. Available as CONF-740921

  19. Experimental Investigation of Turbine Vane Heat Transfer for Alternative Fuels

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nix, Andrew Carl

    The focus of this program was to experimentally investigate advanced gas turbine cooling schemes and the effects of and factors that contribute to surface deposition from particulate matter found in coal syngas exhaust flows on turbine airfoil heat transfer and film cooling, as well as to characterize surface roughness and determine the effects of surface deposition on turbine components. The program was a comprehensive, multi-disciplinary collaborative effort between aero-thermal and materials faculty researchers and the Department of Energy, National Energy Technology Laboratory (NETL). The primary technical objectives of the program were to evaluate the effects of combustion of syngas fuelsmore » on heat transfer to turbine vanes and blades in land-based power generation gas turbine engines. The primary questions to be answered by this investigation were; What are the factors that contribute to particulate deposition on film cooled gas turbine components? An experimental program was performed in a high-temperature and pressure combustion rig at the DOE NETL; What is the effect of coal syngas combustion and surface deposition on turbine airfoil film cooling? Deposition of particulate matter from the combustion gases can block film cooling holes, decreasing the flow of the film coolant and the film cooling effectiveness; How does surface deposition from coal syngas combustion affect turbine surface roughness? Increased surface roughness can increase aerodynamic losses and result in decreased turbine hot section efficiency, increasing engine fuel consumption to maintain desired power output. Convective heat transfer is also greatly affected by the surface roughness of the airfoil surface; Is there any significant effect of surface deposition or erosion on integrity of turbine airfoil thermal barrier coatings (TBC) and do surface deposits react with the TBC in any way to decrease its thermal insulating capability? Spallation and erosion of TBC is a persistent problem in modern turbine engines; and What advancements in film cooling hole geometry and design can increase effectiveness of film cooling in turbines burning high-hydrogen coal syngas due to the higher heat loads and mass flow rates of the core flow? Experimental and numerical investigations of advanced cooling geometries that can improve resistance to surface deposition were performed. The answers to these questions were investigated through experimental measurements of turbine blade surface temperature and coolant coverage (via infrared camera images and thermocouples) and time-varying surface roughness in the NETL high-pressure combustion rig with accelerated, simulated surface deposition and advanced cooling hole concepts, coupled with detailed materials analysis and characterization using conventional methods of Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), 3-D Surface Topography (using a 3-D stylus profilometer). Detailed surface temperatures and cooling effectiveness could not be measured due to issues with the NETL infrared camera system. In collaboration with faculty startup funding from the principal investigator, experimental and numerical investigations were performed of an advanced film cooling hole geometry, the anti-vortex hole (AVH), focusing on improving cooling effectiveness and decreasing the counter-rotating vortex of conventional cooling holes which can entrain mainstream particulate matter to the surface. The potential benefit of this program is in gaining a fundamental understanding of how the use of alternative fuels will effect the operation of modern gas turbine engines, providing valuable data for more effective cooling designs for future turbine systems utilizing alternative fuels.« less

  20. PM2.5 ORGANIC COMPOSITION FROM SEVERAL SITES IN THE UNITED STATES

    EPA Science Inventory

    Organic constituents make up an important component of fine particulate matter (PM2.5) in ambient environments. While part of the composition of organic aerosol results from emissions of primary sources, an additional component appears to come from gas-to-particle conversion o...

  1. RECRUITING AND RETAINING AFRICAN-AMERICANS FOR AN EXPOSURE STUDY IN SOUTHEAST RALEIGH

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) recently completed a study of African-Americans' exposure to particulate matter (PM) in Southeast Raleigh. A primary goal was to compare PM levels measured at ambient and residential sites with those from personal exposure monitors...

  2. Respiratory deposition of inhaled micron particles in subjects with mild asthma

    EPA Science Inventory

    Rational: Particulate matter (PM) in the ambient air can cause adverse health effects to some people including an aggravation of asthma. Although compromised lung conditions in disease are likely to be the primary cause of the effects, enhanced respiratory dose of particles may a...

  3. Semivolatile POA and parameterized total combustion SOA in CMAQv5.2: impacts on source strength and partitioning

    EPA Science Inventory

    Mounting evidence from field and laboratory observations coupled with atmospheric model analyses shows that primary combustion emissions of organic compounds dynamically partition between the vapor and particulate phases, especially as near-source emissions dilute and cool to amb...

  4. HAP-PRO USER'S MANUAL (FOR USE WITH VERSION 1.0)

    EPA Science Inventory

    The primary purpose of the Hazardous Air Pollutant Program (HAP-PRO) is to assist permit engineers in reviewing applications for control of air toxics by calculating the capital and annual costs for 6 volatile organic compound (VOC) and 3 different particulate control devices, i...

  5. COMPARATIVE IN VITRO CARDIAC TOXICITY OF PRIMARY COMBUSTION PARTICLES: IDENTIFICATION OF CAUSAL CONSTITUENTS AND MECHANISMS OF INJURY

    EPA Science Inventory

    Identification of causal particle characteristics and mechanisms of injury would allow linkage of particulate air pollution adverse health effects to sources. Research has examined the direct cardiovascular effects of air pollution particle constituents since previous studies dem...

  6. STRUCTURE OF PRIMARY PM2.5 DERIVED FROM DIESEL TRUCK EXHAUST

    EPA Science Inventory

    The U.S. Environmental Protection Agency is currently considering regulations on airborne particulate matter < 2.5 microns in mean diameter (PM2.5). It is important that the molecular structure and microstructure of PM2.5 from various sources be thoroughly characterized in order ...

  7. Chemical characterization and sources of PM2.5 at 12-h resolution in Guiyang, China

    EPA Science Inventory

    The increasing emission of primary and gaseous precursors of secondarily formed atmospheric particulate matter due to continuing industrial development and urbanization are leading to an increased public awareness of environmental issues and human health risks in China. As part o...

  8. 40 CFR Table 3 to Subpart Ttttt of... - Initial Compliance With Emission Limits

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants for Primary Magnesium... dryer stack a. The average mass flow of particulate matter from the control system applied to emissions...

  9. The role of the premotor cortex and the primary motor cortex in action verb comprehension: evidence from Granger causality analysis.

    PubMed

    Yang, Jie; Shu, Hua

    2012-08-01

    Although numerous studies find the premotor cortex and the primary motor cortex are involved in action language comprehension, so far the nature of these motor effects is still in controversy. Some researchers suggest that the motor effects reflect that the premotor cortex and the primary motor cortex make functional contributions to the semantic access of action verbs, while other authors argue that the motor effects are caused by comprehension. In the current study, we used Granger causality analysis to investigate the roles of the premotor cortex and the primary motor cortex in processing of manual-action verbs. Regions of interest were selected in the primary motor cortex (M1) and the premotor cortex based on a hand motion task, and in the left posterior middle temporal gyrus (lexical semantic area) based on the reading task effect. We found that (1) the left posterior middle temporal gyrus had a causal influence on the left M1; and (2) the left posterior middle temporal gyrus and the left premotor cortex had bidirectional causal relations. These results suggest that the premotor cortex and the primary motor cortex play different roles in manual verb comprehension. The premotor cortex may be involved in motor simulation that contributes to action language processing, while the primary motor cortex may be engaged in a processing stage influenced by the meaning access of manual-action verbs. Further investigation combining effective connectivity analysis and technique with high temporal resolution is necessary for better clarification of the roles of the premotor cortex and the primary motor cortex in action language comprehension. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. A Comprehensive Primary Health Care Delivery Model.

    ERIC Educational Resources Information Center

    Pullen, Carol; And Others

    1994-01-01

    This primary health care model is based on four assumptions: emphasis on collective, not individual, needs; coordination of preventive/episodic care with secondary/tertiary care; comprehensive, holistic approach; and partnership and equality among professional disciplines and community members. Stakeholders involved are medical, nursing, and…

  11. Seasonal dynamics of particulate organic matter in the Changjiang Estuary and adjacent coastal waters illustrated by amino acid enantiomers

    NASA Astrophysics Data System (ADS)

    Wu, Ying; Liu, Zongguang; Hu, Jun; Zhu, Zhuoyi; Liu, Sumei; Zhang, Jing

    2016-02-01

    Total suspended matter (TSM) was collected in the Changjiang Estuary and adjacent areas of the East China Sea in July, August, and November 2011, to study the composition and fate of particulate organic nitrogen (PON) during an August typhoon event and bottom trawling activities. Concentrations of particulate organic carbon (POC), particulate nitrogen (PN), and hydrolyzable particulate amino acids (PAA, D- and L-enantiomers) were higher during July and August than during November; however, D-arginine and alanine levels were significantly higher in November. Seasonal trends in the composition of PAAs indicate that in situ production is a key factor in their temporal distribution. No significant increase in TSM or decrease in labile organic matter was observed during the transit period following a typhoon event in August. In contrast, higher primary production was observed at this time as a result of the penetration of Changjiang Diluted Water caused by the typhoon event. Trawling effects were studied by comparing the calm season (July) with the bottom-trawling period (November) at similar sampling sites. The effect of trawling on the composition of bottom organic matter was studied by comparing D-amino acids concentrations and C/N ratios in the calm season (July) with the bottom-trawling period (November). A substantial contribution of microbial organic matter during the November cruise was indicated by a decrease in glutamic acid, an increase in TSM and D-alanine, and a lower carbon/nitrogen (C/N) ratio. In shallow coastal regions, anthropogenic activities (bottom trawling) may enhance the transfer of low-nutritional-value particulate organic matter into the benthic food chain.

  12. Impact of maritime traffic on polycyclic aromatic hydrocarbons, metals and particulate matter in Venice air.

    PubMed

    Gregoris, Elena; Barbaro, Elena; Morabito, Elisa; Toscano, Giuseppa; Donateo, Antonio; Cesari, Daniela; Contini, Daniele; Gambaro, Andrea

    2016-04-01

    Harbours are important hubs for economic growth in both tourism and commercial activities. They are also an environmental burden being a source of atmospheric pollution often localized near cities and industrial complexes. The aim of this study is to quantify the relative contribution of maritime traffic and harbour activities to atmospheric pollutant concentration in the Venice lagoon. The impact of ship traffic was quantified on various pollutants that are not directly included in the current European legislation for shipping emission reduction: (i) gaseous and particulate PAHs; (ii) metals in PM10; and (iii) PM10 and PM2.5. All contributions were correlated with the tonnage of ships during the sampling periods and results were used to evaluate the impact of the European Directive 2005/33/EC on air quality in Venice comparing measurements taken before and after the application of the Directive (year 2010). The outcomes suggest that legislation on ship traffic, which focused on the issue of the emissions of sulphur oxides, could be an efficient method also to reduce the impact of shipping on primary particulate matter concentration; on the other hand, we did not observe a significant reduction in the contribution of ship traffic and harbour activities to particulate PAHs and metals. Graphical abstract Impact of maritime traffic on polycyclic aromatic hydrocarbons, metals and particulate matter and evaluation of the effect of an European Directive on air quality in Venice.

  13. The Effect of the Thinking-Aloud Strategy on the Reading Comprehension Skills of 4th Grade Primary School Students

    ERIC Educational Resources Information Center

    Sönmez, Yasemin; Sulak, Süleyman Erkam

    2018-01-01

    The purpose of this study, which is designed in quasi-experimental model, is to examine the effect of the thinking aloud strategy on the reading comprehension skills of the 4th grade primary school students. For this purpose, in the second semester of 2016-2017 academic year, the reading comprehension levels of 26 students in the 4th grade at a…

  14. Recent Advances in Lipid-Based Vesicles and Particulate Carriers for Topical and Transdermal Application.

    PubMed

    Jain, Shashank; Patel, Niketkumar; Shah, Mansi K; Khatri, Pinak; Vora, Namrata

    2017-02-01

    In the recent decade, skin delivery (topical and transdermal) has gained an unprecedented popularity, especially due to increased incidences of chronic skin diseases, demand for targeted and patient compliant delivery, and interest in life cycle management strategies among pharmaceutical companies. Literature review of recent publications indicates that among various skin delivery systems, lipid-based delivery systems (vesicular carriers and lipid particulate systems) have been the most successful. Vesicular carriers consist of liposomes, ultradeformable liposomes, and ethosomes, while lipid particulate systems consist of lipospheres, solid lipid nanoparticles, and nanostructured lipid carriers. These systems can increase the skin drug transport by improving drug solubilization in the formulation, drug partitioning into the skin, and fluidizing skin lipids. Considering that lipid-based delivery systems are regarded as safe and efficient, they are proving to be an attractive delivery strategy for the pharmaceutical as well as cosmeceutical drug substances. However, development of these delivery systems requires comprehensive understanding of physicochemical characteristics of drug and delivery carriers, formulation and process variables, mechanism of skin delivery, recent technological advancements, specific limitations, and regulatory considerations. Therefore, this review article encompasses recent research advances addressing the aforementioned issues. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  15. Using Advanced Monitoring Tools to Evaluate PM PM2.5 2.5 in San Joaquin Valley

    EPA Science Inventory

    One of the primary data deficiencies that prevent the advance of policy relevant research on particulate matter, ozone, and associated precursors is the lack of measurement data and knowledge on the true vertical profile and synoptic-scale spatial distributions of the pollutants....

  16. INHIBITION OF PROTEIN TYROSINE PHOSPHATASE ACTIVITY MEDIATES EPIDERMAL GROWTH FACTOR RECEPTOR SIGNALING IN HUMAN AIRWAY EPITHELIAL CELLS

    EPA Science Inventory

    Epidemiological studies have implicated zinc in the toxicity of ambient particulate matter (PM) inhalation. We previously showed that exposure to metal-laden PM inhibits protein tyrosine phosphatase (PTP) activity in human primary bronchial epithelial cells (HAEC) and leads t...

  17. Evaluation of a regional air-quality model with bidirectional NH3 exchange coupled to an agroecosystem modelecosystem model

    EPA Science Inventory

    Atmospheric ammonia (NH3) is the primary atmospheric base and an important precursor for inorganic particulate matter and when deposited NH3 contributes to surface water eutrophication, soil acidification and decline in species biodiversity. Flux measurement...

  18. DIAGNOSTIC MODEL EVALUATION FOR CARBONACEOUS PM 2.5 USING ORGANIC MARKERS MEASURED IN THE SOUTHEASTERN U.S.

    EPA Science Inventory

    Summertime concentrations of fine particulate carbon in the southeastern United States are consistently underestimated by air quality models. In an effort to understand the cause of this error, the Community Multiscale Air Quality (CMAQ) model is instrumented to track primary org...

  19. Fire and Pesticides: A Review of Air Quality Considerations

    Treesearch

    Parshall B. Bush; Daniel G. Neary; Charles K. McMahon

    2000-01-01

    The classes of primary chemical products naturally produced by the combustion of forest fuels are: carbon dioxide, water, carbon monoxide, particulate matter, methane and non-methane hydrocarbons, polynuclear aromatic hydrocarbons, nitrogen and sulfur oxides, aldehydes, free radicals, and inorganic elements. Secondary chemical products produced by reactions in smoke...

  20. MONITORING FOOD WEB CHANGES IN TIDE-RESTORED SALT MARSHES: A CARBON STABLE ISOTOPE APPROACH

    EPA Science Inventory

    Primary producer (angiosperms, macroalgae, submerged aquatic vegetation), suspended particulate matter, and Fundulus heteroclitus isotope values (d13C , d15N, d34S) were examined to assess their use as an indicator for changes in food web support functions in tidally-restored sal...

  1. PARTICIPANT RECRUITMENT AND RETENTION FOR THE NERL RTP PM PANEL STUDY

    EPA Science Inventory

    EPA's National Exposure Research Laboratory (NERL) completed a 12 month Particulate Matter (PM) Panel Study in the Research Triangle Park, NC area in May 2001. A primary goal of the study was to compare PM levels measured at an ambient and residential sites with those from per...

  2. LESSONS LEARNED FROM FOUR EXPOSURE PANEL STUDIES: THE U.S. EPA'S PARTICULATE MATTER STUDIES INVOLVING ELDERLY COHORTS

    EPA Science Inventory

    The U.S. Environmental Protection Agency and its collaborators are conducting a series of human exposure panel studies on elderly (65+ years) subpopulations. The primary objectives of these studies are

    -To determine personal and indoor exposures to particles and relate...

  3. DESIGN AND CHARACTERIZATION OF AN ULTRAFINE COAL ASH AEROSOL GENERATOR FOR DIRECT ANIMAL EXPOSURE STUDIES

    EPA Science Inventory

    Primary ultrafine particulate matter (PM) is produced during pulverized coal combustion by the nucleation and heterogeneous condensation of vapor-phase species. This differs from the mechanisms that control the formation of the supermicron fly ash that is heavily influenced by t...

  4. POWER ANALYSIS OF LINEAR RELATIONSHIPS BETWEEN PERSONAL EXPOSURE AND INDOOR/OUTDOOR PM 2.5 CONCENTRATIONS AT BALTIMORE AND FRESNO

    EPA Science Inventory

    The National Exposure Research Laboratory is currently in the process of conducting panel studies to investigate personal exposure to particulate matter(PM). One of the primary goals of PM exposure studies is to establish mathematical relationships between personal exposure and...

  5. INVESTIGATION OF PRIMARY FINE PARTICULATE MATTER FROM COAL COMBUSTION BY COMPUTER-CONTROLLED SCANNING ELECTRON MICROSCOPY

    EPA Science Inventory

    The particle size distributions, morphologies, and chemical composition distributions of 14 coal fly ash (CFA) samples produced by the combustion of four western U.S. coals (two subbituminous, one lignite, and one bituminous) and three eastern U.S. coals (all bituminous) have bee...

  6. COMPARISON OF INTEGRATED SAMPLERS FOR MASS AND COMPOSITION DURING THE 1999 ATLANTA SUPERSITES PROJECT

    EPA Science Inventory

    The first of EPA's Particulate Matter (PM) Supersites projects was established in Atlanta, GA during the summer of 1999 in conjunction with the Southern Oxidants Study. The short-term primary focus was a one month intensive field campaign to evaluate advanced PM measurement me...

  7. TLR-2 IS INVOLVED IN AIRWAY EPITHELIAL CELL RESPONE TO AIR POLLUTION PARTICLES

    EPA Science Inventory

    Primary cultures of normal human airway epithelial cells (NHBE) respond to ambient air pollution particulate matter (PM) by increased production of the cytokine IL-8, and the induction of a number of oxidant stress response genes. Components of ambient air PM responsible for stim...

  8. A CASE-CROSSOVER ANALYSIS OF PARTICULATE MATTER AIR POLLUTION AND OUT-OF-HOSPITAL PRIMARY CARDIAC ARREST. (R827355C001)

    EPA Science Inventory

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

  9. Electro-optic and holographic measurement techniques for the atmospheric sciences. [considering spacecraft simulation applications

    NASA Technical Reports Server (NTRS)

    Moore, W. W., Jr.; Lemons, J. F.; Kurtz, R. L.; Liu, H.-K.

    1977-01-01

    A comprehensive examination is made of recent advanced research directions in the applications of electro-optical and holographic instrumentations and methods to atmospheric sciences problems. In addition, an overview is given of the in-house research program for environmental and atmospheric measurements with emphasis on particulates systems. Special treatment is made of the instrument methods and applications work in the areas of laser scattering spectrometers and pulsed holography sizing systems. Selected engineering tests data on space simulation chamber programs are discussed.

  10. Chemical characteristics and source apportionment of fine particulate organic carbon in Hong Kong during high particulate matter episodes in winter 2003

    NASA Astrophysics Data System (ADS)

    Li, Yun-Chun; Yu, Jian Zhen; Ho, Steven Sai Hang; Schauer, James J.; Yuan, Zibing; Lau, Alexis K. H.; Louie, Peter K. K.

    2013-02-01

    PM2.5 samples were collected at six general stations and one roadside station in Hong Kong in two periods of high particulate matter (PM) in 2003 (27 October-4 November and 30 November-13 December). The highest PM2.5 reached 216 μg m- 3 during the first high PM period and 113 μg m- 3 during the second high PM period. Analysis of synoptic weather conditions identified individual sampling days under dominant influence of one of three types of air masses, that is, local, regional and long-range transported (LRT) air masses. Roadside samples were discussed separately due to heavy influences from vehicular emissions. This research examines source apportionment of fine organic carbon (OC) and contribution of secondary organic aerosol on high PM days under different synoptic conditions. Six primary OC (POC) sources (vehicle exhaust, biomass burning, cooking, cigarette smoke, vegetative detritus, and coal combustion) were identified on the basis of characteristic organic tracers. Individual POC source contributions were estimated using chemical mass balance model. In the roadside and the local samples, OC was dominated by the primary sources, accounting for more than 74% of OC. In the samples influenced by regional and LRT air masses, secondary OC (SOC), which was approximated to be the difference between the total measured OC and the apportioned POC, contributed more than 54% of fine OC. SOC was highly correlated with water-soluble organic carbon and sulfate, consistent with its secondary nature.

  11. Dynamic Management of NOx and SO2 Emissions in the Texas and Mid-Atlantic Electric Power Systems and Implications for Air Quality.

    PubMed

    McDonald-Buller, Elena; Kimura, Yosuke; Craig, Michael; McGaughey, Gary; Allen, David; Webster, Mort

    2016-02-02

    Cap and trade programs have historically been designed to achieve annual or seasonal reductions in emissions of nitrogen oxides and sulfur dioxide from power plants. Emissions reductions may not be temporally coincident with meteorological conditions conducive to the formation of peak ozone and fine particulate matter concentrations. Integrated power system and air quality modeling methods were developed to evaluate time-differentiated emissions price signals on high ozone days in the Mid-Atlantic portion of the Pennsylvania-New Jersey-Maryland (PJM) Interconnection and Electric Reliability Council of Texas (ERCOT) grids. Sufficient flexibility exists in the two grids with marked differences in demand and fuel generation mix to accommodate time-differentiated emissions pricing alone or in combination with a season-wide program. System-wide emissions reductions and production costs from time-differentiated pricing are shown to be competitive with those of a season-wide program on high ozone days and would be more cost-effective if the primary policy goal was to target emissions reductions on these days. Time-differentiated pricing layered as a complement to the Cross-State Air Pollution Rule had particularly pronounced benefits for the Mid-Atlantic PJM system that relies heavily on coal-fired generation. Time-differentiated pricing aimed at reducing ozone concentrations had particulate matter reduction co-benefits, but if particulate matter reductions are the primary objective, other approaches to time-differentiated pricing may lead to greater benefits.

  12. Comparative Soot Diagnostics: Preliminary Results

    NASA Technical Reports Server (NTRS)

    Urban, David L.; Griffin, DeVon W.; Gard, Melissa Y.

    1997-01-01

    The motivation for the Comparative Soot Diagnostics (CSD) experiment lies in the broad practical importance of understanding combustion generated particulate. Depending upon the circumstances, particulate matter can affect the durability and performance of combustion equipment, can be a pollutant, can be used to detect fires and, in the form of soot, can be the dominant source of radiant energy from flames. The nonbuoyant structure of most flames of practical interest makes understanding of soot processes in low gravity flames important to our ability to predict fire behavior on earth. These studies also have direct applications to fire safety in human-crew spacecraft, since smoke is the indicator used for automated detection in current spacecraft. In the earliest missions (Mercury, Gemini and Apollo), the crew quarters were so cramped that it was considered reasonable that the astronauts would rapidly detect any fire. The Skylab module, however, included approximately 20 UV-sensing fire detectors. The Space Shuttle has 9 particle-ionization smoke detectors in the mid-deck and flight deck and Spacelab has six additional particle-ionization smoke detectors. The designated detectors for the ISS are laser-diode, forward-scattering, smoke or particulate detectors. Current plans for the ISS call for two detectors in the open area of the module, and detectors in racks that have both cooling air flow and electrical power. Due to the complete absence of data concerning the nature of particulate and radiant emission from incipient and fully developed low-g fires, all three of these detector systems were designed based upon l-g test data and experience. As planned mission durations and complexity increase and the volume of spacecraft increases, the need for and importance of effective, crew-independent, fire detection grows significantly. To provide this level of protection, more knowledge is needed concerning low-gravity fire phenomena and, in particular, how they might be detected and suppressed. Prior to CSD, no combustion-generated particulate samples had been collected near the flame zone for well-developed microgravity flames. All of the extant data either came from drop tower tests and therefore only corresponded to the early stages of a fire or were collected far from the flame zone. The fuel sources in the drop tower tests were restricted to laminar gas-jet diffusion flames and very rapidly overheated wire insulation. The gas-jet tests indicated, through thermophoretic sampling, (2) that soot primaries and aggregates (groups of primary particles) in low-gravity may be significantly larger than those in normal gravity (1-g). This raises new scientific questions about soot processes as well as practical issues for particulate size sensitivity and detection alarm threshold levels used in on-orbit smoke detectors. Preliminary tests in the 2.2 second drop tower suggest that particulate generated by overheated wire insulation may be larger in low-g than in 1-g. Transmission Electron Microscope (TEM) grids downstream of the fire region in the Wire Insulation Flammability experiment as well as visual observation of long string-like aggregates, further confirm this suggestion. The combined impact of these limited results and theoretical predictions is that, as opposed to extrapolation from l-g data, direct knowledge of low-g combustion particulate is needed for more confident design of smoke detectors for spacecraft. This paper describes the operation and preliminary results of the CSD, a project conceived and developed at NASA Lewis Research Center. The CSD flight experiment was conducted in the Middeck Glovebox Facility (MGBX) on USMP-3. The project is support by NASA Headquarters Microgravity Science and Applications Division and Code Q. The results presented here are from the microgravity portion of the experiment, including the temporal response of the detectors and average sizes of the primary and aggregate particles captured on the thermophoretic probes.

  13. [Coal fineness effect on primary particulate matter features during pulverized coal combustion].

    PubMed

    Lü, Jian-yi; Li, Ding-kai

    2007-09-01

    Three kinds of coal differed from fineness were burned in a laboratory-scale drop tube furnace for combustion test, and an 8-stage Andersen particle impactor was employed for sampling the primary particulate matter (PM), in order to study coal fineness effect on primary PM features during pulverized coal combustion. It has been shown that the finer the coal was, the finer the PM produced. PM, emission amount augmented with coal fineness decreased, and the amount of PM10 increased from 13 mg/g to 21 mg/g respectively generated by coarse coal and fine coal. The amount of PM2.5 increased from 2 mg/g to 8 mg/g at the same condition. Constituents and content in bulk ash varied little after three different fineness coal combustion, while the appearance of grading PM differed visibly. The value of R(EE) increased while the coal fineness deceased. The volatility of trace elements which were investigated was Pb > Cr > Zn > Cu > Ni in turn. The concentration of poisonous trace elements was higher which generated from fine coal combustion. The volatilization capacity was influenced little by coal fineness, but the volatilization extent was influenced differently by coal fineness. Fine coal combustion affects worse environment than coarse coal does.

  14. Factors influencing mobile source particulate matter emissions-to-exposure relationships in the Boston urban area.

    PubMed

    Greco, Susan L; Wilson, Andrew M; Hanna, Steven R; Levy, Jonathan I

    2007-11-15

    Benefit-cost and regulatory impact analyses often use atmospheric dispersion models with coarse resolution to estimate the benefits of proposed mobile source emission control regulations. This approach may bias health estimates or miss important intra-urban variability for primary air pollutants. In this study, we estimate primary fine particulate matter (PM2.5) intake fractions (iF; the fraction of a pollutant emitted from a source that is inhaled by the population) for each of 23 398 road segments in the Boston Metro Core area to evaluate the potential for intra-urban variability in the emissions-to-exposure relationship. We estimate iFs using the CAL3QHCR line source model combined with residential populations within 5000 m of each road segment. The annual average values for the road segments range from 0.8 to 53 per million, with a mean of 12 per million. On average, 46% of the total exposure is realized within 200 m of the road segment, though this varies from 0 to 93% largely due to variable population patterns. Our findings indicate the likelihood of substantial intra-urban variability in mobile source primary PM2.5 iF that accounting for population movement with time, localized meteorological conditions, and street-canyon configurations would likely increase.

  15. Diagnostic air quality model evaluation of source-specific primary and secondary fine particulate carbon.

    PubMed

    Napelenok, Sergey L; Simon, Heather; Bhave, Prakash V; Pye, Havala O T; Pouliot, George A; Sheesley, Rebecca J; Schauer, James J

    2014-01-01

    Ambient measurements of 78 source-specific tracers of primary and secondary carbonaceous fine particulate matter collected at four midwestern United States locations over a full year (March 2004-February 2005) provided an unprecedented opportunity to diagnostically evaluate the results of a numerical air quality model. Previous analyses of these measurements demonstrated excellent mass closure for the variety of contributing sources. In this study, a carbon-apportionment version of the Community Multiscale Air Quality (CMAQ) model was used to track primary organic and elemental carbon emissions from 15 independent sources such as mobile sources and biomass burning in addition to four precursor-specific classes of secondary organic aerosol (SOA) originating from isoprene, terpenes, aromatics, and sesquiterpenes. Conversion of the source-resolved model output into organic tracer concentrations yielded a total of 2416 data pairs for comparison with observations. While emission source contributions to the total model bias varied by season and measurement location, the largest absolute bias of -0.55 μgC/m(3) was attributed to insufficient isoprene SOA in the summertime CMAQ simulation. Biomass combustion was responsible for the second largest summertime model bias (-0.46 μgC/m(3) on average). Several instances of compensating errors were also evident; model underpredictions in some sectors were masked by overpredictions in others.

  16. Decadal-scale export of nitrogen, phosphorus, and sediment from the Susquehanna River basin, USA: Analysis and synthesis of temporal and spatial patterns

    USGS Publications Warehouse

    Zhang, Qian; Ball, William P.; Moyer, Douglas

    2016-01-01

    The export of nitrogen (N), phosphorus (P), and suspended sediment (SS) is a long-standing management concern for the Chesapeake Bay watershed, USA. Here we present a comprehensive evaluation of nutrient and sediment loads over the last three decades at multiple locations in the Susquehanna River basin (SRB), Chesapeake's largest tributary watershed. Sediment and nutrient riverine loadings, including both dissolved and particulate fractions, have generally declined at all sites upstream of Conowingo Dam (non-tidal SRB outlet). Period-of-record declines in riverine yield are generally smaller than those in source input, suggesting the possibility of legacy contributions. Consistent with other watershed studies, these results reinforce the importance of considering lag time between the implementation of management actions and achievement of river quality improvement. Whereas flow-normalized loadings for particulate species have increased recently below Conowingo Reservoir, those for upstream sites have declined, thus substantiating conclusions from prior studies about decreased reservoir trapping efficiency. In regard to streamflow effects, statistically significant log-linear relationships between annual streamflow and annual constituent load suggest the dominance of hydrological control on the inter-annual variability of constituent export. Concentration-discharge relationships revealed general chemostasis and mobilization effects for dissolved and particulate species, respectively, both suggesting transport-limitation conditions. In addition to affecting annual export rates, streamflow has also modulated the relative importance of dissolved and particulate fractions, as reflected by its negative correlations with dissolved P/total P, dissolved N/total N, particulate P/SS, and total N/total P ratios. For land-use effects, period-of-record median annual yields of N, P, and SS all correlate positively with the area fraction of non-forested land but negatively with that of forested land under all hydrological conditions. Overall, this work has informed understanding with respect to four major factors affecting constituent export (i.e., source input, reservoir modulation, streamflow, and land use) and demonstrated the value of long-term river monitoring.

  17. Environmental Issues in Managing Asthma

    PubMed Central

    Diette, Gregory B; McCormack, Meredith C; Hansel, Nadia N; Breysse, Patrick N; Matsui, Elizabeth C

    2008-01-01

    Management of asthma requires attention to environmental exposures both indoors and outdoors. Americans spend most of their time indoors, where they have a greater ability to modify their environment. The indoor environment contains both pollutants (eg, particulate matter, nitrogen dioxide, secondhand smoke, and ozone) and allergens from furred pets, dust mites, cockroaches, rodents, and molds. Indoor particulate matter consists of particles generated from indoor sources such as cooking and cleaning activities, and particles that penetrate from the outdoors. Nitrogen dioxide sources include gas stoves, furnaces, and fireplaces. Indoor particulate matter and nitrogen dioxide are linked to asthma morbidity. The indoor ozone concentration is mainly influenced by the outdoor ozone concentration. The health effects of indoor ozone exposure have not been well studied. In contrast, there is substantial evidence of detrimental health effects from secondhand smoke. Guideline recommendations are not specific for optimizing indoor air quality. The 2007 National Asthma Education and Prevention Program asthma guidelines recommend eliminating indoor smoking and improving the ventilation. Though the guidelines state that there is insufficient evidence to recommend air cleaners, air cleaners and reducing activities that generate indoor pollutants may be sound practical approaches for improving the health of individuals with asthma. The guidelines are more specific about allergen avoidance; they recommend identifying allergens to which the individual is immunoglobin E sensitized and employing a multifaceted, comprehensive strategy to reduce exposure. Outdoor air pollutants that impact asthma include particulate matter, ozone, nitrogen dioxide, and sulfur dioxide, and guidelines recommend that individuals with asthma avoid exertion outdoors when these pollutants are elevated. Outdoor allergens include tree, grass, and weed pollens, which vary in concentration by season. Recommendations to reduce exposure include staying indoors, keeping windows and doors closed, using air conditioning and perhaps high-efficiency particulate arrestor (HEPA) air filters, and thorough daily washing to remove allergens from one’s person. PMID:18426614

  18. Compositional Analysis of Fine Particulate Matter in Fairbanks, Alaska

    NASA Astrophysics Data System (ADS)

    Nattinger, K.; Simpson, W. R.; Huff, D.

    2015-12-01

    Fairbanks, AK experiences extreme pollution episodes that result in winter violations of the fine particulate matter (PM2.5) National Ambient Air Quality Standards. This poses a significant health risk for the inhabitants of the area. These high levels result from trapping of pollution in a very shallow boundary layer due to local meteorology, but the role of primary (direct emission) of particulate matter versus secondary production (in the atmosphere) of particulate matter is not understood. Analysis of the PM2.5 composition is being conducted to provide insight into sources, trends, and chemistry. Methods are developed to convert carbon data from IMPROVE (post-2009 analysis method) to NIOSH (pre-2009 method) utilizing blank subtraction, sampler bias adjustment, and inter-method correlations from co-located samples. By converting all carbon measurements to a consistent basis, long-term trends can be analyzed. The approach shows excellent mass closure between PM2.5 mass reconstructed from constituents and gravimetric-analyzed mass. This approach could be utilized in other US locations where the carbon analysis methods also changed. Results include organic and inorganic fractional mass percentages, analyzed over an eight-year period for two testing sites in Fairbanks and two in the nearby city of North Pole. We focus on the wintertime (Nov—Feb) period when most air quality violations occur and find that the particles consist primarily of organic carbon, with smaller percentages of sulfate, elemental carbon, ammonium, and nitrate. The Fairbanks area PM2.5 organic carbon / elemental carbon partitioning matches the source profile of wood smoke. North Pole and Fairbanks PM2.5 have significant compositional differences, with North Pole having a larger percentage of organic matter. Mass loadings in SO42-, NO3-, and total PM2.5 mass correlate with temperature. Multi-year temporal trends show little if any change with a strong effect from temperature. Insights from this study regarding primary versus possible secondary PM2.5 production processes can help in identifying effective PM2.5 control strategies.

  19. Using backup generators for meeting peak electricity demand: a sensitivity analysis on emission controls, location, and health endpoints.

    PubMed

    Gilmore, Elisabeth A; Adams, Peter J; Lave, Lester B

    2010-05-01

    Generators installed for backup power during blackouts could help satisfy peak electricity demand; however, many are diesel generators with nonnegligible air emissions that may damage air quality and human health. The full (private and social) cost of using diesel generators with and without emission control retrofits for fine particulate matter (PM2.5) and nitrogen oxides (NOx) were compared with a new natural gas turbine peaking plant. Lower private costs were found for the backup generators because the capital costs are mostly ascribed to reliability. To estimate the social costs from air quality, the changes in ambient concentrations of ozone (O3) and PM2.5 were modeled using the Particulate Matter Comprehensive Air Quality Model with extensions (PMCAMx) chemical transport model. These air quality changes were translated to their equivalent human health effects using concentration-response functions and then into dollars using estimates of "willingness-to-pay" to avoid ill health. As a case study, 1000 MW of backup generation operating for 12 hr/day for 6 days in each of four eastern U.S. cities (Atlanta, Chicago, Dallas, and New York) was modeled. In all cities, modeled PM2.5 concentrations increased (up to 5 microg/m3) due mainly to primary emissions. Smaller increases and decreases were observed for secondary PM2.5 with more variation between cities. Increases in NOx, emissions resulted in significant nitrate formation (up to 1 microg/m3) in Atlanta and Chicago. The NOx emissions also caused O3 decreases in the urban centers and increases in the surrounding areas. For PM2.5, a social cost of approximately $2/kWh was calculated for uncontrolled diesel generators in highly populated cities but was under 10 cent/kWh with PM2.5 and NOx controls. On a full cost basis, it was found that properly controlled diesel generators are cost-effective for meeting peak electricity demand. The authors recommend NOx and PM2.5 controls.

  20. Impact of aftertreatment devices on primary emissions and secondary organic aerosol formation potential from in-use diesel vehicles: results from smog chamber experiments

    NASA Astrophysics Data System (ADS)

    Chirico, R.; Decarlo, P. F.; Heringa, M. F.; Tritscher, T.; Richter, R.; Prévôt, A. S. H.; Dommen, J.; Weingartner, E.; Wehrle, G.; Gysel, M.; Laborde, M.; Baltensperger, U.

    2010-12-01

    Diesel particulate matter (DPM) is a significant source of aerosol in urban areas and has been linked to adverse health effects. Although newer European directives have introduced increasingly stringent standards for primary PM emissions, gaseous organics emitted from diesel cars can still lead to large amounts of secondary organic aerosol (SOA) in the atmosphere. Here we present results from smog chamber investigations characterizing the primary organic aerosol (POA) and the corresponding SOA formation at atmospherically relevant concentrations for three in-use diesel vehicles with different exhaust aftertreatment systems. One vehicle lacked exhaust aftertreatment devices, one vehicle was equipped with a diesel oxidation catalyst (DOC) and the third vehicle used both a DOC and diesel particulate filter (DPF). The experiments presented here were obtained from the vehicles at conditions representative of idle mode, and for one car in addition at a speed of 60 km/h. An Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was used to measure the organic aerosol (OA) concentration and to obtain information on the chemical composition. For the conditions explored in this paper, primary aerosols from vehicles without a particulate filter consisted mainly of black carbon (BC) with a low fraction of organic matter (OM, OM/BC < 0.5), while the subsequent aging by photooxidation resulted in a consistent production of SOA only for the vehicles without a DOC and with a deactivated DOC. After 5 h of aging ~80% of the total organic aerosol was on average secondary and the estimated "emission factor" for SOA was 0.23-0.56 g/kg fuel burned. In presence of both a DOC and a DPF, only 0.01 g SOA per kg fuel burned was produced within 5 h after lights on. The mass spectra indicate that POA was mostly a non-oxidized OA with an oxygen to carbon atomic ratio (O/C) ranging from 0.10 to 0.19. Five hours of oxidation led to a more oxidized OA with an O/C range of 0.21 to 0.37.

  1. Impact of aftertreatment devices on primary emissions and secondary organic aerosol formation potential from in-use diesel vehicles: results from smog chamber experiments

    NASA Astrophysics Data System (ADS)

    Chirico, R.; Decarlo, P. F.; Heringa, M. F.; Tritscher, T.; Richter, R.; Prevot, A. S. H.; Dommen, J.; Weingartner, E.; Wehrle, G.; Gysel, M.; Laborde, M.; Baltensperger, U.

    2010-06-01

    Diesel particulate matter (DPM) is a significant source of aerosol in urban areas and has been linked to adverse health effects. Although newer European directives have introduced increasingly stringent standards for primary PM emissions, gaseous organics emitted from diesel cars can still lead to large amounts of secondary organic aerosol (SOA) in the atmosphere. Here we present results from smog chamber investigations characterizing the primary organic aerosol (POA) and the corresponding SOA formation at atmospherically relevant concentrations for three in-use diesel vehicles with different exhaust aftertreatment systems. One vehicle lacked exhaust aftertreatment devices, one vehicle was equipped with a diesel oxidation catalyst (DOC) and the final vehicle used both a DOC and diesel particulate filter (DPF). The experiments presented here were obtained from the vehicles at conditions representative of idle mode, and for one car in addition at a speed of 60 km/h. An Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was used to measure the organic aerosol (OA) concentration and to obtain information on the chemical composition. For the conditions explored in this paper, primary aerosols from vehicles without a particulate filter consisted mainly of black carbon (BC) with a low fraction of organic matter (OM, OM/BC<0.5), while the subsequent aging by photooxidation resulted in a consistent production of SOA only for the vehicles without a DOC and with a deactivated DOC. After 5 h of aging ~80% of the total organic aerosol was on average secondary and the estimated "emission factor" for SOA was 0.23-0.56 g/kg fuel burned. In presence of both a DOC and a DPF, primary particles with a mobility diameter above 5 nm were 300±19 cm-3, and only 0.01 g SOA per kg fuel burned was produced within 5 h after lights on. The mass spectra indicate that POA was mostly a non-oxidized OA with an oxygen to carbon atomic ratio (O/C) ranging from 0.097 to 0.190. Five hours of oxidation led to a more oxidized OA with an O/C range of 0.208 to 0.369.

  2. Global Biogeochemical Fluxes Program for the Ocean Observatories Initiative: A Proposal. (Invited)

    NASA Astrophysics Data System (ADS)

    Ulmer, K. M.; Taylor, C.

    2010-12-01

    The overarching emphasis of the Global Biogeochemical Flux Ocean Observatories Initiative is to assess the role of oceanic carbon, both living and non-, in the Earth climate system. Modulation of atmospheric CO2 and its influence on global climate is a function of the quantitative capacity of the oceans to sequester organic carbon into deep waters. Critical to our understanding of the role of the oceans in the global cycling of carbon are the quantitative dynamics in both time and space of the fixation of CO2 into organic matter by surface ocean primary production and removal of this carbon to deep waters via the “biological pump”. To take the next major step forward in advancing our understanding of the oceanic biological pump, a global observation program is required that: (i) greatly improves constraints on estimates of global marine primary production (PP), a critical factor in understanding the global CO2 cycle and for developing accurate estimates of export production (EP); (ii) explores the spatiotemporal links between PP, EP and the biogeochemical processes that attenuate particulate organic carbon (POC) flux; (iii) characterizes microbial community structure and dynamics both in the surface and deep ocean; (iv) develops a comprehensive picture of the chemical and biological processes that take place from the surface ocean to the sea floor; (v) provides unique time-series samples for detailed laboratory-based chemical and biological characterization and tracer studies that will enable connections to be made between the operation of the biological pump at present and in the geologic past. The primary goal is to provide high quality biological and biogeochemical observational data for the modeling and prediction efforts of the global CO2 cycle research community. Crucial to the realization of the GBF-OOI is the development of reliable, long-term, time-series ocean observation platforms capable of precise and controlled placement of sophisticated biogeochemical sensors/samplers, and in situ experimental systems at a wide range of depths, including close proximity to the sea surface. Significant opportunities exist to exploit sensor miniaturization in combination with recent exponential improvements in “omics” technologies for measurement of nucleic acids, proteins and metabolites with unprecedented throughput and resolution. We will discuss the goals, philosophy, principal experimental and technical approaches and operational challenges. We will outline proposed mooring systems as well as means for accurate, spatiotemporal assessment of: (i) primary production, (ii) constraint of POC export flux with season and depth, (iii) assessment of microbial and zooplankton community structure/function throughout the water column, and (iv) collection and preservation of particulate and water samples for land-based examination of temporal and vertical variability of specific tracers, isotopes, nutrients, DOC and related substances for even more precise measurements of environmental biogeochemical properties. The GBF-OOI will become our Hubble for the sea.

  3. Neural network-based estimates of Southern Ocean net community production from in-situ and satellite observation: A methodological study

    NASA Astrophysics Data System (ADS)

    Chang, C.; Johnson, N. C.; Cassar, N.

    2012-12-01

    Although the Southern Ocean (SO) net community production (NCP), which is the difference between gross primary production and the community respiration rate, plays an important role in the global carbon cycle, limited in situ measurements prohibit a thorough understanding of the climatology and variability NCP in this region. In order to achieve a more comprehensive characterization of temporal and spatial variability of Southern Ocean NCP, we use a neural network approach based on the self-organizing map (SOM) to reconstruct weekly gridded (1o x 1o) SO NCP maps for the period of 1998-2009. This approach combines in situ measurements of NCP from over 40 research cruises with satellite-derived NCP predictor data, which includes chlorophyll (Chl), particulate organic carbon (POC), photosynthetically available radiation (PAR), sea surface height (SSH), and sea surface temperature (SST), as well as the mixed layer depth (MLD) from a high-resolution ocean general circulation model forced with satellite observed wind. The resulting NCP reconstructions reveal a number of salient features, including low NCP in the subtropics except near land masses, elevated NCP along the subtropical front (STF) around 40oS and especially off the Atlantic coast of the South America between the Río de la Plata and the Falkland Island, and moderate NCP values near Kerguelen Islands and along the Antarctic coast. Peak SO NCP occurs during November - January, as expected, and the climatological NCP field during the growing season closely resembles the climatological POC field. This neural network approach, which reveals complex nonlinear relationships and readily handles missing predictor data, provides a comprehensive view of SO NCP and an opportunity to investigate variability over a period of more than ten years. Convergence of various approaches;

  4. Bidirectional Relations between Text Reading Prosody and Reading Comprehension in the Upper Primary School Grades: A Longitudinal Perspective

    PubMed Central

    Veenendaal, Nathalie J.; Groen, Margriet A.; Verhoeven, Ludo

    2016-01-01

    The purpose of this study was to examine the directionality of the relationship between text reading prosody and reading comprehension in the upper grades of primary school. We compared three theoretical possibilities: Two unidirectional relations from text reading prosody to reading comprehension and from reading comprehension to text reading prosody and a bidirectional relation between text reading prosody and reading comprehension. Further, we controlled for autoregressive effects and included decoding efficiency as a measure of general reading skill. Participants were 99 Dutch children, followed longitudinally, from fourth- to sixth-grade. Structural equation modeling showed that the bidirectional relation provided the best fitting model. In fifth-grade, text reading prosody was related to prior decoding and reading comprehension, whereas in sixth-grade, reading comprehension was related to prior text reading prosody. As such, the results suggest that the relation between text reading prosody and reading comprehension is reciprocal, but dependent on grade level. PMID:27667916

  5. Prediction is Production: The missing link between language production and comprehension.

    PubMed

    Martin, Clara D; Branzi, Francesca M; Bar, Moshe

    2018-01-18

    Language comprehension often involves the generation of predictions. It has been hypothesized that such prediction-for-comprehension entails actual language production. Recent studies provided evidence that the production system is recruited during language comprehension, but the link between production and prediction during comprehension remains hypothetical. Here, we tested this hypothesis by comparing prediction during sentence comprehension (primary task) in participants having the production system either available or not (non-verbal versus verbal secondary task). In the primary task, sentences containing an expected or unexpected target noun-phrase were presented during electroencephalography recording. Prediction, measured as the magnitude of the N400 effect elicited by the article (expected versus unexpected), was hindered only when the production system was taxed during sentence context reading. The present study provides the first direct evidence that the availability of the speech production system is necessary for generating lexical prediction during sentence comprehension. Furthermore, these important results provide an explanation for the recruitment of language production during comprehension.

  6. Primary particulate emissions and secondary organic aerosol (SOA) formation from idling diesel vehicle exhaust in China.

    PubMed

    Deng, Wei; Hu, Qihou; Liu, Tengyu; Wang, Xinming; Zhang, Yanli; Song, Wei; Sun, Yele; Bi, Xinhui; Yu, Jianzhen; Yang, Weiqiang; Huang, Xinyu; Zhang, Zhou; Huang, Zhonghui; He, Quanfu; Mellouki, Abdelwahid; George, Christian

    2017-09-01

    In China diesel vehicles dominate the primary emission of particulate matters from on-road vehicles, and they might also contribute substantially to the formation of secondary organic aerosols (SOA). In this study tailpipe exhaust of three typical in-use diesel vehicles under warm idling conditions was introduced directly into an indoor smog chamber with a 30m 3 Teflon reactor to characterize primary emissions and SOA formation during photo-oxidation. The emission factors of primary organic aerosol (POA) and black carbon (BC) for the three types of Chinese diesel vehicles ranged 0.18-0.91 and 0.15-0.51gkg-fuel -1 , respectively; and the SOA production factors ranged 0.50-1.8gkg-fuel -1 and SOA/POA ratios ranged 0.7-3.7 with an average of 2.2. The fuel-based POA emission factors and SOA production factors from this study for idling diesel vehicle exhaust were 1-3 orders of magnitude higher than those reported in previous studies for idling gasoline vehicle exhaust. The emission factors for total particle numbers were 0.65-4.0×10 15 particleskg-fuel -1 , and particles with diameters less than 50nm dominated in total particle numbers. Traditional C 2 -C 12 precursor non-methane hydrocarbons (NMHCs) could only explain less than 3% of the SOA formed during aging and contribution from other precursors including intermediate volatile organic compounds (IVOC) needs further investigation. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Primary Care Attributes and Care for Depression Among Low-Income African American Women

    PubMed Central

    O’Malley, Ann S.; Forrest, Christopher B.; Miranda, Jeanne

    2003-01-01

    Objectives. We examined the association between attributes of primary care providers and care for depression, from a patients’ perspective, among a sample of predominantly low-income African American women. Methods. Computer-assisted telephone interviews were conducted among a population-based sample of 1202 women residing in Washington, DC. Results. Respondents whose primary care physicians provided more comprehensive medical services were more likely to be asked about and treated for depressive symptoms than women whose providers were less medically comprehensive. Women who rated their providers as having more respect for them also were more likely to be asked about and treated for depression. Conclusions. More comprehensive primary care delivery and a physician–patient relationship focused on mutual respect are associated with greater rates of physician inquiry about and treatment for depression among vulnerable women. PMID:12893623

  8. Observations and analysis of organic aerosol evolution in some prescribed fire smoke plumes

    Treesearch

    A. A. May; T. Lee; G. R. McMeeking; S. Akagi; A. P. Sullivan; S. Urbanski; R. J. Yokelson; S. M. Kreidenweis

    2015-01-01

    Open biomass burning is a significant source of primary air pollutants such as particulate matter (PM) and non-methane organic gases (NMOG). However, the physical and chemical atmospheric processing of these emissions during transport is poorly understood. Atmospheric transformations of biomass burning emissions have been investigated in environmental chambers, but...

  9. THE ROLE OF GENETIC SUSCEPTIBILITY IN EXPERIMENTAL INDUCTION CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) AND PARTICULATE MATTER (PM) HEALTH EFFECTS.

    EPA Science Inventory

    Human COPD represents the 4th common cause of mortality worldwide and is characterized by presence of chronic bronchitis/inflammation and emphysema. The primary cause is cigarette smoking, as nearly all COPD patients are smokers. However, only about 10% of smokers develop this di...

  10. Air Pollution and Its Effects on an Individual's Health and Exercise Performance.

    ERIC Educational Resources Information Center

    Singh, A. I. Clifford

    1988-01-01

    Air Pollution is a common environmental stressor affecting the training and competitive performance of athletes, commonly irritating the eyes, nose, and throat. The health and exercise effects of such primary and secondary air pollutants as carbon monoxide, sulfur dioxide, air particulates, ozone, and nitrogen dioxide are discussed. (CB)

  11. EXPOSURE TO AMBIENT FINE PARTICULATE MATTER AND PRIMARY CARDIAC ARREST AMONG PERSONS WITH AND WITHOUT CLINICALLY RECOGNIZED HEART DISEASE. (R827355C001)

    EPA Science Inventory

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

  12. 40 CFR 52.1173 - Control strategy: Particulates.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... on the quantity of total dissolved solids in the quench water. (12) The State adopts and submits... establishes 2023 motor vehicle emissions budgets for the Detroit-Ann Arbor area of 4,360 tpy for primary PM2.5...), has been approved as submitted on July 5, 2011. The maintenance plan establishes 2023 motor vehicle...

  13. Reading Fluency as an Indicator of Reading Comprehension

    ERIC Educational Resources Information Center

    Basaran, Mustafa

    2013-01-01

    This study examined the relationship between fourth grade primary school students' reading habits/conditions/ situations and their comprehension regarding what they read. For this purpose, a correlational survey method was used in the study. 90 fourth-grade students who were attending a state primary school in the center of Ku¨tahya participated…

  14. The Contribution of Segmental and Suprasegmental Phonology to Reading Comprehension

    ERIC Educational Resources Information Center

    Veenendaal, Nathalie J.; Groen, Margriet A.; Verhoeven, Ludo

    2016-01-01

    The aim of the present study was to examine the relation between decoding and segmental and suprasegmental phonology, and their contribution to reading comprehension, in the upper primary grades. Following a longitudinal design, the performance of 99 Dutch primary school students on phonological awareness (segmental phonology) and text-reading…

  15. Environmental assessment of an enhanced-oil-recovery steam generator equipped with a low-NOx burner. Volume 1. Technical results. Final report, January 1984-January 1985

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Castaldini, C.; Waterland, L.R.; Lips, H.I.

    1986-02-01

    The report discusses results from sampling flue gas from an enhanced-oil-recovery steam generator (EOR steamer) equipped with an MHI PM low-NOx burner. The tests included burner performance/emission mapping tests, comparative testing of an identical steamer equipped with a conventional burner, and comprehensive testing of the low-NOx-burner-equipped steamer. Comprehensive test measurements included continuous flue-gas monitoring; source assessment sampling system testing with subsequent laboratory analysis to give total flue-gas organics in two boiling point ranges and specific quantitation on the semivolatile organic priority pollutants; C1 to C6 hydrocarbon sampling; Methods 5/8 sampling for particulate and SO/sub 2/ and SO/sub 3/ emissions; andmore » emitted particle size distribution tests using Andersen impactors. Full-load NOx emissions of 110 ppm (3% O/sub 2/) could be maintained from the low-NOx burner at acceptable CO and smoke emissions, compared to about 300 ppm (3% O/sub 2/) from the conventional-burner-equipped steamer. At the low-NOx condition, CO, SO/sub 2/, and SO/sub 3/ emissions were 93, 594, and 3.1 ppm, respectively. Particulate emissions were 39 mg/dscm with a mean particle diameter of 3 to 4 micrometers. Total organic emissions were 11.1 mg/dscm, almost exclusively volatile (C1 to C6) organics. Three PAHs were detected at from 0.1 to 1.4 micrograms/dscm.« less

  16. Environmental assessment of NH/sub 3/ injection for an industrial package boiler. Volume 1. Technical results. Final report, January 1983-January 1984

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Castaldini, C.; DeRosier, R.; Waterland, L.R.

    1986-02-01

    The report discusses emission results from comprehensive flue gas sampling of a gas- and oil-fired industrial boiler equipped with Exxon's Thermal DeNO/sub x/ Ammonia Injection Process for NO/sub x/ reduction. Comprehensive emission measurements included continuous monitoring of flue gas emissions; source assessment sampling system (SASS) tests; EPA Method 5/17 for solid and condensible particulate emissions and ammonia emissions; controlled condensation system for SO/sub 2/ and SO/sub 3/; and N/sub 2/O emission sampling. Ammonia injection at a NH/sub 3//NO molar ratio of 2.52 gave a NO/sub x/ reduction of 41% from an uncontrolled level of 234 ppm to a controlled levelmore » of 137 ppm. NH/sub 3/ emissions increased from 11 ppm for the baseline to an average of 430 ppm for ammonia injection. Nitrous oxide, N/sub 2/O was reduced 68% from a 50 ppm baseline level to a 17 ppm controlled level. Total particulate emissions increased by an order of magnitude from a baseline of 17.7 ng/J to a controlled level of 182 ng/J. The increase is in part attributed to formation of ammonia sulfate and bisulfate from residual ammonia and SO/sub x/. Total organic emissions were at a moderate level and showed a relative concentration in the nonvolatile category. Organic emissions of CO and trace inorganic elements were not significantly affected by ammonia injection.« less

  17. Particulate emissions from a mid-latitude prescribed chaparral fire

    NASA Technical Reports Server (NTRS)

    Cofer, Wesley R., III; Levine, Joel S.; Sebacher, Daniel I.; Winstead, Edward L.; Riggin, Philip J.; Brass, James A.; Ambrosia, Vincent G.

    1988-01-01

    Particulate emission from a 400-acre prescribed chaparral fire in the San Dimas Experimental Forest was investigated by collecting smoke aerosol on Teflon and glass-fiber filters from a helicopter, and using SEM and EDAX to study the features of the particles. Aerosol particles ranged in size from about 0.1 to 100 microns, with carbon, oxygen, magnesium, aluminum, silicon, calcium, and iron as the primary elements. The results of ion chromatographic analysis of aerosol-particle extracts (in water-methanol) revealed the presence of significant levels of NO2(-), NO3(-), SO4(2-), Cl(-), PO4(3-), C2O4(2-), Na(+), NH4(+), and K(+). The soluble ionic portion of the aerosol was estimated to be about 2 percent by weight.

  18. Developing a universal reading comprehension intervention for mainstream primary schools within areas of social deprivation for children with and without language-learning impairment: a feasibility study.

    PubMed

    McCartney, Elspeth; Boyle, James; Ellis, Sue

    2015-01-01

    Some children in areas of social deprivation in Scotland have lower reading attainment than neighbouring children in less deprived areas, and some of these also have lower spoken language comprehension skills than expected by assessment norms. There is a need to develop effective reading comprehension interventions that fit easily into the school curriculum and can benefit all pupils. A feasibility study of reading comprehension strategies with existing evidence of efficacy was undertaken in three mainstream primary schools within an area of social deprivation in west central Scotland, to decide whether further investigation of this intervention was warranted. Aims were to measure comprehension of spoken language and reading via standardised assessments towards the beginning of the school year (T1) in mainstream primary school classrooms within an area of social deprivation; to have teachers introduce previously-validated text comprehension strategies, and to measure change in reading comprehension outcome measures towards the end of the year (T2). A pre- and post-intervention cohort design was used. Reading comprehension strategies were introduced to staff in participating schools and used throughout the school year as part of on-going reading instruction. Spoken language comprehension was measured by TROG-2 at T1, and reading progress by score changes from T1 to T2 on the WIAT-II(UK) -T reading comprehension scale. Forty-seven pupils in five classes in three primary schools took part: 38% had TROG-2 scores below the 10(th) centile. As a group, children made good reading comprehension progress, with a medium effect size of 0.46. Children with TROG-2 scores below the 10(th) centile had lower mean reading scores than others at T1 and T2, although with considerable overlap. However, TROG-2 did not make a unique contribution to reading progress: children below the 10(th) centile made as much progress as other children. The intervention was welcomed by schools, and the measure of reading comprehension proved responsive to change. The outcomes suggest the reading intervention may be effective for children with and without spoken language comprehension difficulties, and warrants further investigation in larger, controlled, studies. © 2014 Royal College of Speech and Language Therapists.

  19. Atmospheric iron fluxes in the northern region of the Gulf of California: Implications for primary production and potential Fe limitation

    NASA Astrophysics Data System (ADS)

    Muñoz-Barbosa, Albino; Segovia-Zavala, José A.; Huerta-Diaz, Miguel Angel; Delgadillo-Hinojosa, Francisco; Torres-Delgado, Eunice V.; Lares, María L.; Marinone, Silvio G.; Gutiérrez-Galindo, Efraín A.

    2017-11-01

    To study the temporal variability of atmospheric mineral dust and Fe fluxes to the northern region of the Gulf of California, dust samples were collected at San Felipe, Baja California (Site 1) and Puerto Peñasco, Sonora (Site 2), from May 2010 to December 2011. Dust fluxes were partially associated with monsoon circulation, with highest (38 ± 20 mg m-2 d-1) and lowest (8.8 ± 4.9 mg m-2 d-1) fluxes linked to southwesterly winds (monsoon season) and north-northwesterly winds (non-monsoon season), respectively. Our analysis suggests that the surrounding deserts are the most probable source of dust arriving into the Gulf of California. However, analyses of Al and Fe concentrations in dusts showed no trends that could identify specific particulate Fe provenance. Average particulate Fe atmospheric fluxes (FeAtm) showed no clear temporal trends and their magnitudes (3.2 ± 3.4 and 6 ± 10 μmol m-2 d-1 for sites 1 and 2, respectively) could be considered medium-to-low in magnitude within a global context. An Fe limitation index (FeLI), calculated as the ratio of phytoplankton Fe requirements to atmospheric and upwelling Fe fluxes, is proposed to estimate the impact of atmospheric mineral dust on phytoplankton primary production in surface waters of the Gulf of California. On a seasonal time scale, FeLI results suggest that under winter conditions, there is no evidence of Fe limitation because upwelling Fe contribution (FeUp) is high enough to support primary production. In contrast, during summer conditions, when FeUp is very low or negligible, high FeAtm combined with high particulate Fe dissolution factors could prevent the northern Gulf of California from becoming Fe-limited. Finally, we postulate that at an interannual scale, conditions prevailing during ENSO events could increase atmospheric Fe fluxes to the Gulf of California, further contributing to prevent Fe limitation in this marginal sea.

  20. Impact of river discharge, upwelling and vertical mixing on the nutrient loading and productivity of the Canadian Beaufort Shelf

    NASA Astrophysics Data System (ADS)

    Tremblay, J.-É.; Raimbault, P.; Garcia, N.; Lansard, B.; Babin, M.; Gagnon, J.

    2014-09-01

    The concentrations and elemental stoichiometry of particulate and dissolved pools of carbon (C), nitrogen (N), phosphorus (P) and silicon (Si) on the Canadian Beaufort Shelf during summer 2009 (MALINA program) were assessed and compared with those of surface waters provided by the Mackenzie river as well as by winter mixing and upwelling of upper halocline waters at the shelf break. Neritic surface waters showed a clear enrichment in dissolved and particulate organic carbon (DOC and POC, respectively), nitrate, total particulate nitrogen (TPN) and dissolved organic nitrogen (DON) originating from the river. Silicate as well as bulk DON and DOC declined in a near-conservative manner away from the delta's outlet, whereas nitrate dropped non-conservatively to very low background concentrations inside the brackish zone. By contrast, the excess of soluble reactive P (SRP) present in oceanic waters declined in a non-conservative manner toward the river outlet, where concentrations were very low and consistent with P shortage in the Mackenzie River. These opposite gradients imply that the admixture of Pacific-derived, SRP-rich water is necessary to allow phytoplankton to use river-derived nitrate and to a lesser extent DON. A coarse budget based on concurrent estimates of primary production shows that river N deliveries support a modest fraction of primary production when considering the entire shelf, due to the ability of phytoplankton to thrive in the subsurface chlorophyll maximum beneath the thin, nitrate-depleted river plume. Away from shallow coastal bays, local elevations in the concentration of primary production and dissolved organic constituents were consistent with upwelling at the shelf break. By contrast with shallow winter mixing, nutrient deliveries by North American rivers and upwelling relax surface communities from N limitation and permit a more extant utilization of the excess SRP entering through the Bering Strait. In this context, increased nitrogen supply by rivers and upwelling potentially alters the vertical distribution of the excess P exported into the North Atlantic.

  1. Seasonal variations in high time-resolved chemical compositions, sources, and evolution of atmospheric submicron aerosols in the megacity Beijing

    NASA Astrophysics Data System (ADS)

    Hu, Wei; Hu, Min; Hu, Wei-Wei; Zheng, Jing; Chen, Chen; Wu, Yusheng; Guo, Song

    2017-08-01

    A severe regional haze problem in the megacity Beijing and surrounding areas, caused by fast formation and growth of fine particles, has attracted much attention in recent years. In order to investigate the secondary formation and aging process of urban aerosols, four intensive campaigns were conducted in four seasons between March 2012 and March 2013 at an urban site in Beijing (116.31° E, 37.99° N). An Aerodyne high-resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS) was deployed to measure non-refractory chemical components of submicron particulate matter (NR-PM1). The average mass concentrations of PM1 (NR-PM1+black carbon) were 45.1 ± 45.8, 37.5 ± 31.0, 41.3 ± 42.7, and 81.7 ± 72.4 µg m-3 in spring, summer, autumn, and winter, respectively. Organic aerosol (OA) was the most abundant component in PM1, accounting for 31, 33, 44, and 36 % seasonally, and secondary inorganic aerosol (SNA, sum of sulfate, nitrate, and ammonium) accounted for 59, 57, 43, and 55 % of PM1 correspondingly. Based on the application of positive matrix factorization (PMF), the sources of OA were obtained, including the primary ones of hydrocarbon-like (HOA), cooking (COA), biomass burning OA (BBOA) and coal combustion OA (CCOA), and secondary component oxygenated OA (OOA). OOA, which can be split into more-oxidized (MO-OOA) and less-oxidized OOA (LO-OOA), accounted for 49, 69, 47, and 50 % in four seasons, respectively. Totally, the fraction of secondary components (OOA+SNA) contributed about 60-80 % to PM1, suggesting that secondary formation played an important role in the PM pollution in Beijing, and primary sources were also non-negligible. The evolution process of OA in different seasons was investigated with multiple metrics and tools. The average carbon oxidation states and other metrics show that the oxidation state of OA was the highest in summer, probably due to both strong photochemical and aqueous-phase oxidations. It was indicated by the good correlations (r = 0.53-0.75, p < 0.01) between LO-OOA and odd oxygen (Ox = O3 + NO2), and between MO-OOA and liquid water content in aerosols. BBOA was resolved in spring and autumn, influenced by agricultural biomass burning (e.g., field preparation burnings, straw burning after the harvest). CCOA was only identified in winter due to domestic heating. These results signified that the comprehensive management for biomass burning and coal combustion emissions is needed. High concentrations of chemical components in PM1 in Beijing, especially in winter or in adverse meteorological conditions, suggest that further strengthening the regional emission control of primary particulate and precursors of secondary species is expected.

  2. CPMs: A Kinesthetic Comprehension Strategy

    ERIC Educational Resources Information Center

    Block, Cathy Collins; Parris, Sheri R.; Whiteley, Cinnamon S.

    2008-01-01

    This article discusses a study to determine whether primary grade students can learn comprehension processes via hand motions to portray these mental processes. Comprehension Process Motions (CPMs) were designed to provide students with a way to make abstract comprehension processes more consciously accessible and also to give teachers a way to…

  3. Particulate Matter Resuspension in Mississippi Bight Evaluated with CONCORDE's Synthesis Model

    NASA Astrophysics Data System (ADS)

    O'Brien, S. J.; Quas, L. M.; Miles, T. N.; Pan, C.; Cambazoglu, M. K.; Soto Ramos, I. M.; Greer, A. T.; Church, I.; Wiggert, J. D.

    2017-12-01

    The CONsortium for oil spill exposure pathways in COastal River-Dominated Ecosystems (CONCORDE) was established to investigate the complex fine-scale biological, chemical and physical interactions in a marine system controlled by pulsed-river plume dynamics. During CONCORDE's spring 2016 field campaign, the In Situ Ichthyoplankton Imaging System (ISIIS) on the R/V Point Sur and the Scanfish on the R/V Pelican comprehensively characterized the physical and biological structure in the region. Increased suspended particulate matter was observed by the ISIIS, with concentrations at depth sufficient to completely occlude the in situ images of planktonic organisms. Data was also collected on the continental shelf during the spring cruise by the RU31 glider in the proximity of the Mississippi River Delta, east of the ISIIS / Scanfish transects. Backscatter and salinity observed by the Scanfish and glider showed elevated suspended particulate matter and increased salinity, suggesting a linkage to shoreward advection from the continental shelf of oceanic waters that are sufficiently energetic to drive sediment resuspension. As part of the CONCORDE research effort, a four-dimensional biogeochemical/lower trophic level synthesis model for Mississippi Sound and Bight has been developed, based on the Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) Modeling System. This study utilizes CONCORDE's synthesis model to investigate the physical forcing mechanisms affecting the increased suspended particulate matter concentration observed in the Mississippi Bight during spring 2016, and advection pathways between estuarine and shelf waters in the northern Gulf of Mexico. The results show that episodic, advection-driven resuspension is a critical aspect controlling suspended sediment distributions in Mississippi Bight, which has implications for observed spatio-temporal patterns of planktonic species.

  4. School Environmental Intervention to Reduce Particulate Pollutant Exposures for Children with Asthma

    PubMed Central

    Jhun, Iny; Gaffin, Jonathan M.; Coull, Brent A.; Huffaker, Michelle F.; Petty, Carter R.; Sheehan, William J.; Baxi, Sachin N.; Lai, Peggy S.; Kang, Choong-Min; Wolfson, Jack M.; Gold, Diane R.; Koutrakis, Petros; Phipatanakul, Wanda

    2016-01-01

    Background Home-based interventions to improve indoor air quality have demonstrated benefits for asthma morbidity, yet little is known about the effect of environmental interventions in the school setting. Objective We piloted the feasibility and effectiveness of a classroom-based air cleaner intervention to reduce particulate pollutants in classrooms of children with asthma. Methods In this pilot randomized controlled trial, we assessed the effect of air cleaners on indoor air particulate pollutant concentrations in 18 classrooms (9 control, 9 intervention) in 3 urban elementary schools. We enrolled 25 asthmatic children (13 control, 12 intervention) aged 6–10 years old. Classroom air pollutant measurements and spirometry were completed once prior to and twice after randomization. Asthma symptoms were surveyed every 3 months. Results Baseline classroom levels of fine particulate matter (PM2.5) and black carbon (BC) were 6.3 μg/m3 and 0.41 μg/m3, respectively. When comparing the intervention to the control group, classroom PM2.5 levels were reduced by 49% and 42%, and BC levels were reduced by 58% and 55% in the first and second follow-up periods, respectively (p < 0.05 for all comparisons). When comparing the children randomized to intervention and control classrooms, there was a modest improvement in peak flow, but no significant changes in forced expiratory volume in 1 second (FEV1) and asthma symptoms. Conclusion In this pilot study, a classroom-based air cleaner intervention led to significant reductions in PM2.5 and BC. Future large-scale studies should comprehensively evaluate the effect of school-based environmental interventions on pediatric asthma morbidity. PMID:27641483

  5. Ambient air concentrations exceeded health-based standards for fine particulate matter and benzene during the Deepwater Horizon oil spill.

    PubMed

    Nance, Earthea; King, Denae; Wright, Beverly; Bullard, Robert D

    2016-02-01

    The Deepwater Horizon oil spill is considered one of the largest marine oil spills in the history of the United States. Air emissions associated with the oil spill caused concern among residents of Southeast Louisiana. The purpose of this study was to assess ambient concentrations of benzene (n=3,887) and fine particulate matter (n=102,682) during the oil spill and to evaluate potential exposure disparities in the region. Benzene and fine particulate matter (PM2.5) concentrations in the targeted parishes were generally higher following the oil spill, as expected. Benzene concentrations reached 2 to 19 times higher than background, and daily exceedances of PM2.5 were 10 to 45 times higher than background. Both benzene and PM2.5 concentrations were considered high enough to exceed public health criteria, with measurable exposure disparities in the coastal areas closer to the spill and clean-up activities. These findings raise questions about public disclosure of environmental health risks associated with the oil spill. The findings also provide a science-based rationale for establishing health-based action levels in future disasters. Benzene and particulate matter monitoring during the Deepwater Horizon oil spill revealed that ambient air quality was a likely threat to public health and that residents in coastal Louisiana experienced significantly greater exposures than urban residents. Threshold air pollution levels established for the oil spill apparently were not used as a basis for informing the public about these potential health impacts. Also, despite carrying out the most comprehensive air monitoring ever conducted in the region, none of the agencies involved provided integrated analysis of the data or conclusive statements about public health risk. Better information about real-time risk is needed in future environmental disasters.

  6. Estimation of Particulate Mass and Manganese Exposure Levels among Welders

    PubMed Central

    Hobson, Angela; Seixas, Noah; Sterling, David; Racette, Brad A.

    2011-01-01

    Background: Welders are frequently exposed to Manganese (Mn), which may increase the risk of neurological impairment. Historical exposure estimates for welding-exposed workers are needed for epidemiological studies evaluating the relationship between welding and neurological or other health outcomes. The objective of this study was to develop and validate a multivariate model to estimate quantitative levels of welding fume exposures based on welding particulate mass and Mn concentrations reported in the published literature. Methods: Articles that described welding particulate and Mn exposures during field welding activities were identified through a comprehensive literature search. Summary measures of exposure and related determinants such as year of sampling, welding process performed, type of ventilation used, degree of enclosure, base metal, and location of sampling filter were extracted from each article. The natural log of the reported arithmetic mean exposure level was used as the dependent variable in model building, while the independent variables included the exposure determinants. Cross-validation was performed to aid in model selection and to evaluate the generalizability of the models. Results: A total of 33 particulate and 27 Mn means were included in the regression analysis. The final model explained 76% of the variability in the mean exposures and included welding process and degree of enclosure as predictors. There was very little change in the explained variability and root mean squared error between the final model and its cross-validation model indicating the final model is robust given the available data. Conclusions: This model may be improved with more detailed exposure determinants; however, the relatively large amount of variance explained by the final model along with the positive generalizability results of the cross-validation increases the confidence that the estimates derived from this model can be used for estimating welder exposures in absence of individual measurement data. PMID:20870928

  7. A Discussion of Procedures and Equipment for the Comprehensive Test Ban Treaty On-Site Inspection Environmental Sampling and Analysis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wogman, Ned A.; Milbrath, Brian D.; Payne, Rosara F.

    This paper is intended to serve as a scientific basis to start discussions of the available environmental sampling techniques and equipment that have been used in the past that could be considered for use within the context of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) on-site inspections (OSI). This work contains information on the techniques, equipment, costs, and some operational procedures associated with environmental sampling that have actually been used in the past by the United States for the detection of nuclear explosions. This paper also includes a discussion of issues, recommendations, and questions needing further study within the context of themore » sampling and analysis of aquatic materials, atmospheric gases, atmospheric particulates, vegetation, sediments and soils, fauna, and drill-back materials.« less

  8. Radionuclide observables during the Integrated Field Exercise of the Comprehensive Nuclear-Test-Ban Treaty.

    PubMed

    Burnett, Jonathan L; Miley, Harry S; Milbrath, Brian D

    2016-03-01

    In 2014 the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) undertook an Integrated Field Exercise (IFE14) in Jordan. The exercise consisted of a simulated 0.5-2 kT underground nuclear explosion triggering an On-site Inspection (OSI) to search for evidence of a Treaty violation. This research paper evaluates two of the OSI techniques used during the IFE14, laboratory-based gamma-spectrometry of soil samples and in-situ gamma-spectrometry, both of which were implemented to search for 17 OSI relevant particulate radionuclides indicative of nuclear explosions. The detection sensitivity is evaluated using real IFE and model data. It indicates that higher sensitivity laboratory measurements are the optimum technique during the IFE and within the Treaty/Protocol-specified OSI timeframes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. A prospective study (SCOPE) comparing the cardiometabolic and respiratory effects of air pollution exposure on healthy and pre-diabetic individuals.

    PubMed

    Wang, Yanwen; Han, Yiqun; Zhu, Tong; Li, Weiju; Zhang, Hongyin

    2018-01-01

    Air pollution is known to be a major risk factor for cardiopulmonary disease, but this is unclear for cardiometabolic disease (e.g. diabetes). This is of considerable public health importance, given the nationwide epidemic of diabetes, accompanied by severe air pollution, in China. The evidence so far remained inadequate to answer questions of whether individuals with cardiometabolic dysfunctions are susceptible to air pollution and whether air pollution exacerbates diabetes development via certain biological pathways. In this manuscript, we summarize the results and limitations of studies exploring these two topics and elaborate our design of a prospective panel study (SCOPE) as a solution. We assessed and compared the health effect of air pollution among pre-diabetic individuals and matched healthy controls through four repeated clinical visits over 1 year. Comprehensive evaluation was made to both health endpoints and exposure. The primary biomarkers were assessed to reveal the impact on multiple biological pathways, including glycolipid metabolism and insulin resistance, endothelial function, and inflammation. Detailed chemical and size fractional components of particulate matter were measured in this study, along with the application of personal monitors. The work should increase our understanding of how air pollution affects individuals with cardiometabolic dysfunction and the underlying mechanisms.

  10. Review of Urban Secondary Organic Aerosol Formation from Gasoline and Diesel Motor Vehicle Emissions.

    PubMed

    Gentner, Drew R; Jathar, Shantanu H; Gordon, Timothy D; Bahreini, Roya; Day, Douglas A; El Haddad, Imad; Hayes, Patrick L; Pieber, Simone M; Platt, Stephen M; de Gouw, Joost; Goldstein, Allen H; Harley, Robert A; Jimenez, Jose L; Prévôt, André S H; Robinson, Allen L

    2017-02-07

    Secondary organic aerosol (SOA) is formed from the atmospheric oxidation of gas-phase organic compounds leading to the formation of particle mass. Gasoline- and diesel-powered motor vehicles, both on/off-road, are important sources of SOA precursors. They emit complex mixtures of gas-phase organic compounds that vary in volatility and molecular structure-factors that influence their contributions to urban SOA. However, the relative importance of each vehicle type with respect to SOA formation remains unclear due to conflicting evidence from recent laboratory, field, and modeling studies. Both are likely important, with evolving contributions that vary with location and over short time scales. This review summarizes evidence, research needs, and discrepancies between top-down and bottom-up approaches used to estimate SOA from motor vehicles, focusing on inconsistencies between molecular-level understanding and regional observations. The effect of emission controls (e.g., exhaust aftertreatment technologies, fuel formulation) on SOA precursor emissions needs comprehensive evaluation, especially with international perspective given heterogeneity in regulations and technology penetration. Novel studies are needed to identify and quantify "missing" emissions that appear to contribute substantially to SOA production, especially in gasoline vehicles with the most advanced aftertreatment. Initial evidence suggests catalyzed diesel particulate filters greatly reduce emissions of SOA precursors along with primary aerosol.

  11. Urban particulate matter pollution: a tale of five cities.

    PubMed

    Pandis, Spyros N; Skyllakou, Ksakousti; Florou, Kalliopi; Kostenidou, Evangelia; Kaltsonoudis, Christos; Hasa, Erion; Presto, Albert A

    2016-07-18

    Five case studies (Athens and Paris in Europe, Pittsburgh and Los Angeles in the United States, and Mexico City in Central America) are used to gain insights into the changing levels, sources, and role of atmospheric chemical processes in air quality in large urban areas as they develop technologically. Fine particulate matter is the focus of our analysis. In all cases reductions of emissions by industrial and transportation sources have resulted in significant improvements in air quality during the last few decades. However, these changes have resulted in the increasing importance of secondary particulate matter (PM) which dominates over primary in most cases. At the same time, long range transport of secondary PM from sources located hundreds of kilometres from the cities is becoming a bigger contributor to the urban PM levels in all seasons. "Non-traditional" sources including cooking, and residential and agricultural biomass burning contribute an increasing fraction of the now reduced fine PM levels. Atmospheric chemistry is found to change the chemical signatures of a number of these sources relatively fast both during the day and night, complicating the corresponding source apportionment.

  12. Vapor-phase and particulate-associated pesticides and PCB concentrations in eastern North Dakota air samples

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hawthorne, S.B.; Miller, D.J.; Louie, P.K.K.

    1996-05-01

    Vapor-phase and suspended particulate (<50 {mu}m) samples were collected on polyurethane foam (PUF) and quartz fiber filters in rural North Dakota to determine the air concentrations of pesticides in an area where agriculture is a primary source of semivolatile pollutants. Samples were collected at two sites from 1992 to 1994 that were at least 0.4 km from the nearest farmed fields and known application of pesticides, and analyzed for 22 different organochlorine, triazine, and acid herbicide pesticides. Fourteen pesticides were found above the detection limits (typically <1 pg/m{sup 3}). Concentrations of polychlorinated biphenyl (PCB) congeners were much lower (<50 pg/m{supmore » 3} in all cases) than many of the pesticides. These results demonstrate that pesticides are among the most prevalent chlorinated semivolatile pollutants present in rural North Dakota, that significant transport of pesticides occurs both in the vapor-phase and on suspended particulate matter, and that blown soil may be a significant mechanism for introducing pesticides into surface and ground waters. 32 refs., 2 figs., 4 tabs.« less

  13. Sources of PM10 Air Pollution in Rural Area in the Vicinity of a Highway In Žilina Selfgoverning Region, Slovakia

    NASA Astrophysics Data System (ADS)

    Jandačka, Dušan

    2015-05-01

    Particulate matter results as an aftermath of numerous distinctive processes in the atmosphere and they become a part of everyday life. Their harmful effect and impact on the ambient environment is determined predominantly by the presence of various chemical substances and elements. The chemical composition of these particles (organic and elemental carbon, mineral dust, sea aerosols, secondary particles, especially sulphates and nitrates, heavy metals and further elements) is mainly impacted on by their origin, whereas the primary source of the particulate matter is determined and specified by the profile of chemical elements and substances. Particulate Matter (PM) may originate in various natural resources or anthropogenic sources. Among the natural sources sea salt is to be counted on, dust of the earth crust, pollen and volcanic ashes. Anthropogenic sources do include, predominantly, burning fossil fuels in the fossil-fuel power plants, local heating of households, burning liquefied fossil fuels in the combustion engines of vehicles, noncombustion related emissions as a result of vehicular traffic, resuspension of the road-traffic-related dust.

  14. Is it the time to study air pollution effects under environmental conditions? A case study to support the shift of in vitro toxicology from the bench to the field.

    PubMed

    Gualtieri, Maurizio; Grollino, Maria Giuseppa; Consales, Claudia; Costabile, Francesca; Manigrasso, Maurizio; Avino, Pasquale; Aufderheide, Michaela; Cordelli, Eugenia; Di Liberto, Luca; Petralia, Ettore; Raschellà, Giuseppe; Stracquadanio, Milena; Wiedensohler, Alfred; Pacchierotti, Francesca; Zanini, Gabriele

    2018-09-01

    Air pollution and particulate matter are recognised cause of increased disease incidence in exposed population. The toxicological processes underlying air pollution associated effects have been investigated by in vivo and/or in vitro experimentation. The latter is usually performed by exposing cells cultured under submerged condition to particulate matter concentration quite far from environmental exposure expected in humans. Here we report for the first time the feasibility of a direct exposure of air liquid interface cultured cells to environmental concentration of particulate matter. Inflammatory proteins release was analysed in cell medium while differential expression of selected genes was analysed in cells. Significant association of anti-oxidant genes was observed with secondary and aged aerosol, while cytochrome activation with primary and PAHs enriched ultrafine particles. The results obtained clearly show the opportunity to move from the lab bench to the field for properly understanding the toxicological effects also of ultrafine particles on selected in vitro models. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Selection of Optical Cavity Surface Coatings for 1micron Laser Based Missions

    NASA Technical Reports Server (NTRS)

    Hedgeland, Randy J.; Straka, Sharon; Matsumura, Mark; Hammerbacher, Joseph

    2004-01-01

    The particulate surface cleanliness level on several coatings for aluminum and beryllium substrates were examined for use in the optical cavities of high pulse energy Nd:YAG Q-switched, diode-pumped lasers for space flight applications. Because of the high intensity of the lasers, any contaminants in the laser beam path could damage optical coatings and limit the instrument mission objectives at the operating wavelength of 1 micron (micrometer). Our goal was to achieve an EST-STD-CC1246D Level 100 particulate distribution or better to ensure particulate redistribution during launch would not adversely affect the performance objectives. Tapelifts were performed to quantify the amount of particles using in-house developed procedures. The primary candidate coatings included chromate conversion coating aluminum (Al), uncoated Al electroless Nickel (Ni) on Al, Ni-gold (Au) on Al, anodized Al, and gold (Au)/Ni on Beryllium (Be). The results indicate that there were advantages in Ni and Au coating applications for the two major substrates, Al and Be, when considering applications that need to meet launch environments.

  16. Assessment of primary and secondary ambient particle trends using satellite aerosol optical depth and ground speciation data in the New England region, United States

    PubMed Central

    Lee, Hyung Joo; Kang, Choong-Min; Coull, Brent A.; Bell, Michelle L.; Koutrakis, Petros

    2014-01-01

    The effectiveness of air pollution emission control policies can be evaluated by examining ambient pollutant concentration trends that are observed at a large number of ground monitoring sites over time. In this paper, we used ground monitoring measurements in conjunction with satellite aerosol optical depth (AOD) data to investigate fine particulate matter (PM2.5; particulate matter with aerodynamic diameter ≤2.5 μm) trends and their spatial patterns over a large U.S. region, New England, during 2000–2008. We examined the trends in rural and urban areas to get a better insight about the trends of regional and local source emissions. Decreases in PM2.5 concentrations (μg/m3) were more pronounced in urban areas than in rural ones. In addition, the highest and lowest PM2.5 decreases (μg/m3) were observed for winter and summer, respectively. Together, these findings suggest that primary particle concentrations decreased more relative to secondary ones. This is also supported by the analysis of the speciation data which showed that downward trends of primary pollutants including black carbon were stronger than those of secondary pollutants including sulfate. Furthermore, this study found that ambient primary pollutants decreased at the same rate as their respective source emissions. This was not the case for secondary pollutants which decreased at a slower rate than that of their precursor emissions. This indicates that concentrations of secondary pollutants depend not only on the primary emissions but also on the availability of atmospheric oxidants which might not change during the study period. This novel approach of investigating spatially varying concentration trends, in combination with ground PM2.5 species trends, can be of substantial regulatory importance. PMID:24906074

  17. Source apportionment and air quality impact assessment studies in Beijing/China

    NASA Astrophysics Data System (ADS)

    Suppan, P.; Schrader, S.; Shen, R.; Ling, H.; Schäfer, K.; Norra, S.; Vogel, B.; Wang, Y.

    2012-04-01

    More than 15 million people in the greater area of Beijing are still suffering from severe air pollution levels caused by sources within the city itself but also from external impacts like severe dust storms and long range advection from the southern and central part of China. Within this context particulate matter (PM) is the major air pollutant in the greater area of Beijing (Garland et al., 2009). PM did not serve only as lead substance for air quality levels and therefore for adverse health impact effects but also for a strong influence on the climate system by changing e.g. the radiative balance. Investigations on emission reductions during the Olympic Summer Games in 2008 have caused a strong reduction on coarser particles (PM10) but not on smaller particles (PM2.5). In order to discriminate the composition of the particulate matter levels, the different behavior of coarser and smaller particles investigations on source attribution, particle characteristics and external impacts on the PM levels of the city of Beijing by measurements and modeling are performed: Examples of long term measurements of PM2.5 filter sampling in 2005 with the objectives of detailed chemical (source attribution, carbon fraction, organic speciation and inorganic composition) and isotopic analyses as well as toxicological assessment in cooperation with several institutions (Karlsruhe Institute of Technology (IfGG/IMG), Helmholtz Zentrum München (HMGU), University Rostock (UR), Chinese University of Mining and Technology Beijing, CUMTB) will be discussed. Further experimental studies include the operation of remote sensing systems to determine continuously the MLH (by a ceilometer) and gaseous air pollutants near the ground (by DOAS systems) as well as at the 320 m measurement tower (adhesive plates at different heights for passive particle collection) in cooperation with the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences (CAS). The influence of the MLH on the air pollution concentration could be demonstrated and will be discussed. The impact of dust storm events on the overall pollution level of particulate matter in the greater area of Beijing is being assessed by the online coupled comprehensive model system COSMO-ART. First results of the dust storm modeling in northern China (2006, April 3rd until 12th) demonstrates very well the general behavior of the meteorological parameters temperature and humidity as well as a good agreement between modeled and measured dust storm concentration variability at Beijing in the course of time. The results show the importance of intertwine investigations of measurements and modeling, the analysis of local air pollution levels as well as the impact and analysis of advective process in the greater region of Beijing. Comprehensive investigations on particulate matter are a prerequisite for the knowledge of the source strengths and source attribution to the overall air pollution level. Only this knowledge can help to formulate and to introduce specific reduction measures to reduce coarser as well as finer particulates.

  18. A comprehensive emission inventory of multiple air pollutants from iron and steel industry in China: Temporal trends and spatial variation characteristics.

    PubMed

    Wang, Kun; Tian, Hezhong; Hua, Shenbing; Zhu, Chuanyong; Gao, Jiajia; Xue, Yifeng; Hao, Jiming; Wang, Yong; Zhou, Junrui

    2016-07-15

    China has become the largest producer of iron and steel throughout the world since 1996. However, as an energy-and-pollution intensive manufacturing sector, a detailed comprehensive emission inventory of air pollutants for iron and steel industry of China is still not available. To obtain and better understand the temporal trends and spatial variation characteristics of typical hazardous air pollutants (HAPs) emissions from iron and steel production in China, a comprehensive emission inventory of multiple air pollutants, including size segregated particulate matter (TSP/PM10/PM2.5), gaseous pollutants (SO2, NOx, CO), heavy metals (Pb, Cd, Hg, As, Cr, Ni etc.), as well as the more dangerous PCDD/Fs, is established with the unit-based annual activity, specific dynamic emission factors for the historical period of 1978-2011, and the future potential trends till to 2050 are forecasted by using scenario analysis. Our results show that emissions of gaseous pollutants and particulate matter have experienced a gradual increase tendency since 2000, while emissions of priority-controlled heavy metals (Hg, Pb, As, Cd, Cr, and Ni) have exhibited a short-term fluctuation during the period of 1990 to 2005. With regard to the spatial distribution of HAPs emissions in base year 2011, Bohai economic circle is identified as the top emission intensity region where iron and steel smelting plants are densely built; within iron and steel industry, blast furnaces contribute the majority of PM emissions, sinter plants account for most of gaseous pollutants and the majority of PCDD/Fs, whereas steel making processes are responsible for the majority of heavy metal emissions. Moreover, comparisons of future emission trends under three scenarios indicate that advanced technologies and integrated whole process management strategies are in great need to further diminish various hazardous air pollutants from iron and steel industry in the future. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. ADVANCES IN CONTROL OF PM2..5 AND PM2..5 PRECURSORS GENERATED BY THE COMBUSTION OF PULVERIZED COAL

    EPA Science Inventory

    Particulate matter smaller than 2.5 micrometers in aerodynamic diameter (PM2.5) is of concern due to adverse health effects associated with elevated ambient mass concentrations of PM2.5. PM2.5 from coal-fired utility boilers is composed of directly emitted (primary) particles and...

  20. 40 CFR 86.004-15 - NOX plus NMHC and particulate averaging, trading, and banking for heavy-duty engines.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... all diesel-cycle engine families within the same primary service class is allowed. (ii) Urban buses... averaging set from all other heavy-duty engines. Averaging and trading between diesel cycle bus engine... heavy-duty engines, the equivalent mileage is 6.3 miles. For diesel heavy-duty engines, the equivalent...

  1. 40 CFR 86.004-15 - NOX plus NMHC and particulate averaging, trading, and banking for heavy-duty engines.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... all diesel-cycle engine families within the same primary service class is allowed. (ii) Urban buses... averaging set from all other heavy-duty engines. Averaging and trading between diesel cycle bus engine... heavy-duty engines, the equivalent mileage is 6.3 miles. For diesel heavy-duty engines, the equivalent...

  2. Smoke management photographic guide: a visual aid for communicating impacts

    Treesearch

    Joshua C. Hyde; Jarod Blades; Troy Hall; Roger D. Ottmar; Alistair Smith

    2016-01-01

    Communicating emissions impacts to the public can sometimes be difficult because quantitatively conveying smoke concentrations is complicated. Regulators and land managers often refer to particulate-matter concentrations in micrograms per cubic meter, but this may not be intuitive or meaningful to everyone. The primary purpose of this guide is to serve as a tool for...

  3. DEVELOPMENT AND EVALUATION OF A HIGH-VOLUME DICHOTOMOUS SAMPLER FOR CHEMICAL SPECIATION OF COARSE AND FINE PARTICLES

    EPA Science Inventory

    This paper describes the development and field evaluation of a compact high-volume dichotomous sampler (HVDS) that collects coarse (PM10-2.5) and fine (PM2.5) particulate matter. In its primary configuration as tested, the sampler size-fractionates PM10 into...

  4. Identifying the Effects of Specific CHC Factors on College Students' Reading Comprehension

    ERIC Educational Resources Information Center

    Taub, Gordon E.; Benson, Nicholas

    2013-01-01

    Reading comprehension is an important skill for college academic success. Much of the research pertaining to reading in general, and reading comprehension specifically, focuses on the success of primary and secondary school-age students. The present study goes beyond previous research by extending such investigation to the reading comprehension of…

  5. Activation of Transient Receptor Potential Ankyrin-1 (TRPA1) in Lung Cells by Wood Smoke Particulate Material

    PubMed Central

    Shapiro, Darien; Deering-Rice, Cassandra E.; Romero, Erin G.; Hughen, Ronald W.; Light, Alan R.; Veranth, John M.; Reilly, Christopher A.

    2013-01-01

    Cigarette smoke, diesel exhaust, and other combustion-derived particles activate the calcium channel transient receptor potential ankyrin-1 (TRPA1), causing irritation and inflammation in the respiratory tract. It was hypothesized that wood smoke particulate and select chemical constituents thereof would also activate TRPA1 in lung cells, potentially explaining the adverse effects of wood and other forms of biomass smoke on the respiratory system. TRPA1 activation was assessed using calcium imaging assays in TRPA1-overexpressing HEK-293 cells, mouse primary trigeminal neurons, and human adenocarcinoma (A549) lung cells. Particles from pine and mesquite smoke were less potent agonists of TRPA1 than an equivalent mass concentration of an ethanol extract of diesel exhaust particles; pine particles were comparable in potency to cigarette smoke condensate, and mesquite particles were the least potent. The fine particulate (PM<2.5 μm) of wood smoke were the most potent TRPA1 agonists and several chemical constituents of wood smoke particulate: 3,5-ditert-butylphenol, coniferaldehyde, formaldehyde, perinaphthenone, agathic acid, and isocupressic acid were TRPA1 agonists. Pine particulate activated TRPA1 in mouse trigeminal neurons and A549 cells in a concentration-dependent manner, which was inhibited by the TRPA1 antagonist HC-030031. TRPA1 activation by wood smoke particles occurred through the electrophile/oxidant-sensing domain (i.e., C621/C641/C665/K710), based on the inhibition of cellular responses when the particles were pre-treated with glutathione; a role for the menthol-binding site of TRPA1 (S873/T874) was demonstrated for 3,5-ditert-butylphenol. This study demonstrated that TRPA1 is a molecular sensor for wood smoke particulate and several chemical constituents thereof, in sensory neurons and A549 cells, suggesting that TRPA1 may mediate some of the adverse effects of wood smoke in humans. PMID:23541125

  6. Variability in sinking fluxes and composition of particle-bound phosphorus in the Xisha area of the northern South China Sea

    NASA Astrophysics Data System (ADS)

    Dong, Yuan; Li, Qian P.; Wu, Zhengchao; Zhang, Jia-Zhong

    2016-12-01

    Export fluxes of phosphorus (P) by sinking particles are important in studying ocean biogeochemical dynamics, whereas their composition and temporal variability are still inadequately understood in the global oceans, including the northern South China Sea (NSCS). A time-series study of particle fluxes was conducted at a mooring station adjacent to the Xisha Trough in the NSCS from September 2012 to September 2014, with sinking particles collected every two weeks by two sediment traps deployed at 500 m and 1500 m depths. Five operationally defined particulate P classes of sinking particles including loosely-bound P, Fe-bound P, CaCO3-bound P, detrital apatite P, and refractory organic P were quantified by a sequential extraction method (SEDEX). Our results revealed substantial variability in sinking particulate P composition at the Xisha over two years of samplings. Particulate inorganic P was largely contributed from Fe-bound P in the upper trap, but detrital P in the lower trap. Particulate organic P, including exchangeable organic P, CaCO3-bound organic P, and refractory organic P, contributed up to 50-55% of total sinking particulate P. Increase of CaCO3-bound P in the upper trap during 2014 could be related to a strong El Niño event with enhanced CaCO3 deposition. We also found sediment resuspension responsible for the unusual high particles fluxes at the lower trap based on analyses of a two-component mixing model. There was on average a total mass flux of 78±50 mg m-2 d-1 at the upper trap during the study period. A significant correlation between integrated primary productivity in the region and particle fluxes at 500 m of the station suggested the important role of biological production in controlling the concentration, composition, and export fluxes of sinking particulate P in the NSCS.

  7. Sorption and Release of Organics by Primary, Anaerobic, and Aerobic Activated Sludge Mixed with Raw Municipal Wastewater

    PubMed Central

    Modin, Oskar; Saheb Alam, Soroush; Persson, Frank; Wilén, Britt-Marie

    2015-01-01

    New activated sludge processes that utilize sorption as a major mechanism for organics removal are being developed to maximize energy recovery from wastewater organics, or as enhanced primary treatment technologies. To model and optimize sorption-based activated sludge processes, further knowledge about sorption of organics onto sludge is needed. This study compared primary-, anaerobic-, and aerobic activated sludge as sorbents, determined sorption capacity and kinetics, and investigated some characteristics of the organics being sorbed. Batch sorption assays were carried out without aeration at a mixing velocity of 200 rpm. Only aerobic activated sludge showed net sorption of organics. Sorption of dissolved organics occurred by a near-instantaneous sorption event followed by a slower process that obeyed 1st order kinetics. Sorption of particulates also followed 1st order kinetics but there was no instantaneous sorption event; instead there was a release of particles upon mixing. The 5-min sorption capacity of activated sludge was 6.5±10.8 mg total organic carbon (TOC) per g volatile suspend solids (VSS) for particulate organics and 5.0±4.7 mgTOC/gVSS for dissolved organics. The observed instantaneous sorption appeared to be mainly due to organics larger than 20 kDa in size being sorbed, although molecules with a size of about 200 Da with strong UV absorbance at 215–230 nm were also rapidly removed. PMID:25768429

  8. Smoke detection in low-G fires

    NASA Technical Reports Server (NTRS)

    Urban, David L.; Griffin, Devon W.; Gard, Melissa Y.; Hoy, Michael

    1995-01-01

    Fires in spacecraft are considered a credible risk. To respond to this risk, NASA flew fire detectors on Skylab and the Space Shuttle (STS) and included them in the design for International Space Station Alpha (ISSA). In previous missions (Mercury, Gemini and Apollo), the crew quarters were so cramped that it was not considered credible that the astronauts could fail to observe a fire. The Skylab nodule included approximately 20 UV fire detectors. The space shuttle has 9 ionization detectors in the mid deck and flight deck and Spacelab has six additional ionization detectors. The planned detectors for ISSA are laser-diode, forward-scattering, smoke or particulate detectors. Current plans for the ISSA call for two detectors in the open area of the module and detectors in racks that have both cooling air flow and electrical power. Due to the complete absence of data concerning the nature of particulate and radiant emission from low-g fires, all three of these detector systems were designed based upon 1-g test data. As planned mission durations and complexity increase and the volume of spacecraft increases, the need for and importance of effective, crew independent, fire detection grows significantly. This requires more knowledge concerning low-gravity fires and how they might be detected. To date, no combustion-generated particulate samples have been collected for well-developed microgravity flames. All of the extant data come from drop tower tests and therefore only correspond to the early stages of a fire. The fuel sources were restricted to laminar gas-jet diffusion flames and rapidly overheated wire insulation. These gas-jet drop tower tests indicate, through thermophoretic sampling, that soot primaries and aggregates (groups of primary particles) in micro-g may be significantly larger than those in normal-g (ng). This raises new scientific questions about soot processes as well as practical issues for particulate detection/alarm threshold levels used in on-orbit smoke detectors. Furthermore, it is widely speculated but unverified that the aggregates will grow to very large scales in a microgravity fire of longer duration than available on the ground. Preliminary tests in the 2.2 second drop tower suggest that particulate generated by overheated wire insulation will also be larger in microgravity than in normal gravity. TEM grids downstream of the fire region in the WIF experiment as well as visual observation of long string-like aggregates, further confirm this suggestion. The combined impact of these limited results and theoretical predictions is that direct knowledge of low-g combustion particulate as opposed to extrapolation from 1-g data is needed for a more confident design of smoke detectors for spacecraft.

  9. Reading Comprehension: A Computerized Intervention with Primary-age Poor Readers.

    PubMed

    Horne, Joanna Kathryn

    2017-05-01

    The current study investigates the effectiveness of a computerized reading comprehension programme on the reading accuracy, reading comprehension and reading rate of primary-age poor readers. There is little published literature relating to computerized reading interventions in UK primary schools, and no previous studies have investigated the Comprehension Booster programme. Thirty-eight children (26 boys and 12 girls; aged 6:7 to 11:0) from two schools in East Yorkshire, UK, took part. Half of the participants (the intervention group) undertook the Comprehension Booster programme for a 6-week period, whilst the other half (the control group) continued with their usual teaching. Significant effects of the intervention were found, with increases in reading accuracy and reading comprehension for the intervention group. It is concluded that computerized reading programmes can be effective in improving reading skills, and these are particularly useful for pupils with reading difficulties in disadvantaged areas, where resources are limited and family support in reading is lower. However, such programmes are not a replacement for good teaching, and regular monitoring of children with reading difficulties is required. Further research is necessary to compare the programme used here to other conventional and computerized intervention programmes, using a larger sample. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  10. Clarifying Linguistic Comprehension in the Simple View of Reading: The Influence of Word-, Sentence-, and Discourse-Level Linguistic Skills on Reading Comprehension

    ERIC Educational Resources Information Center

    Santoro, Julie Kay

    2012-01-01

    There are a high number of students who struggle with reading comprehension beyond the primary grades and understanding the skills involved in successful reading comprehension continues to be a topic of investigation. The Simple View of Reading (SVR) is a viable theory of reading that suggests reading comprehension results from developing skills…

  11. Comparisons of aerosol optical depth provided by seviri satellite observations and CAMx air quality modelling

    NASA Astrophysics Data System (ADS)

    Fernandes, A.; Riffler, M.; Ferreira, J.; Wunderle, S.; Borrego, C.; Tchepel, O.

    2015-04-01

    Satellite data provide high spatial coverage and characterization of atmospheric components for vertical column. Additionally, the use of air pollution modelling in combination with satellite data opens the challenging perspective to analyse the contribution of different pollution sources and transport processes. The main objective of this work is to study the AOD over Portugal using satellite observations in combination with air pollution modelling. For this purpose, satellite data provided by Spinning Enhanced Visible and Infra-Red Imager (SEVIRI) on-board the geostationary Meteosat-9 satellite on AOD at 550 nm and modelling results from the Chemical Transport Model (CAMx - Comprehensive Air quality Model) were analysed. The study period was May 2011 and the aim was to analyse the spatial variations of AOD over Portugal. In this study, a multi-temporal technique to retrieve AOD over land from SEVIRI was used. The proposed method takes advantage of SEVIRI's high temporal resolution of 15 minutes and high spatial resolution. CAMx provides the size distribution of each aerosol constituent among a number of fixed size sections. For post processing, CAMx output species per size bin have been grouped into total particulate sulphate (PSO4), total primary and secondary organic aerosols (POA + SOA), total primary elemental carbon (PEC) and primary inert material per size bin (CRST1 to CRST_4) to be used in AOD quantification. The AOD was calculated by integration of aerosol extinction coefficient (Qext) on the vertical column. The results were analysed in terms of temporal and spatial variations. The analysis points out that the implemented methodology provides a good spatial agreement between modelling results and satellite observation for dust outbreak studied (10th -17th of May 2011). A correlation coefficient of r=0.79 was found between the two datasets. This work provides relevant background to start the integration of these two different types of the data in order to improve air pollution assessment.

  12. A Longitudinal Study of the Role of Reading Motivation in Primary Students' Reading Comprehension: Implications for a Less Simple View of Reading

    ERIC Educational Resources Information Center

    Cartwright, Kelly B.; Marshall, Timothy R.; Wray, Erica

    2016-01-01

    Although substantial research indicates motivation contributes significant variance to reading comprehension in upper elementary students, research with students in primary grades has focused, instead, on the relation of motivation to word reading. Assessment of reading motivation in 68 first and second graders indicated word and nonword reading…

  13. Case Study of an Aboriginal Community-Controlled Health Service in Australia

    PubMed Central

    Baum, Fran; Lawless, Angela; Labonté, Ronald; Sanders, David; Boffa, John; Edwards, Tahnia; Javanparast, Sara

    2016-01-01

    Abstract Universal health coverage provides a framework to achieve health services coverage but does not articulate the model of care desired. Comprehensive primary health care includes promotive, preventive, curative, and rehabilitative interventions and health equity and health as a human right as central goals. In Australia, Aboriginal community-controlled health services have pioneered comprehensive primary health care since their inception in the early 1970s. Our five-year project on comprehensive primary health care in Australia partnered with six services, including one Aboriginal community-controlled health service, the Central Australian Aboriginal Congress. Our findings revealed more impressive outcomes in several areas—multidisciplinary work, community participation, cultural respect and accessibility strategies, preventive and promotive work, and advocacy and intersectoral collaboration on social determinants of health—at the Aboriginal community-controlled health service compared to the other participating South Australian services (state-managed and nongovernmental ones). Because of these strengths, the Central Australian Aboriginal Congress’s community-controlled model of comprehensive primary health care deserves attention as a promising form of implementation of universal health coverage by articulating a model of care based on health as a human right that pursues the goal of health equity. PMID:28559679

  14. Processing of positive-causal and negative-causal coherence relations in primary school children and adults: a test of the cumulative cognitive complexity approach in German.

    PubMed

    Knoepke, Julia; Richter, Tobias; Isberner, Maj-Britt; Naumann, Johannes; Neeb, Yvonne; Weinert, Sabine

    2017-03-01

    Establishing local coherence relations is central to text comprehension. Positive-causal coherence relations link a cause and its consequence, whereas negative-causal coherence relations add a contrastive meaning (negation) to the causal link. According to the cumulative cognitive complexity approach, negative-causal coherence relations are cognitively more complex than positive-causal ones. Therefore, they require greater cognitive effort during text comprehension and are acquired later in language development. The present cross-sectional study tested these predictions for German primary school children from Grades 1 to 4 and adults in reading and listening comprehension. Accuracy data in a semantic verification task support the predictions of the cumulative cognitive complexity approach. Negative-causal coherence relations are cognitively more demanding than positive-causal ones. Moreover, our findings indicate that children's comprehension of negative-causal coherence relations continues to develop throughout the course of primary school. Findings are discussed with respect to the generalizability of the cumulative cognitive complexity approach to German.

  15. Comprehensive Characterization Of Ultrafine Particulate Emission From 2007 Diesel Engines: PM Size Distribution, Loading And Indidividual Particle Size And Composition.

    NASA Astrophysics Data System (ADS)

    Zelenyuk, A.; Cuadra-Rodriguez, L. A.; Imre, D.; Shimpi, S.; Warey, A.

    2006-12-01

    The strong absorption of solar radiation by black carbon (BC) impacts the atmospheric radiative balance in a complex and significant manner. One of the most important sources of BC is vehicular emissions, of which diesel represents a significant fraction. To address this issue the EPA has issues new stringent regulations that will be in effect in 2007, limiting the amount of particulate mass that can be emitted by diesel engines. The new engines are equipped with aftertreatments that reduce PM emissions to the point, where filter measurements are subject to significant artifacts and characterization by other techniques presents new challenges. We will present the results of the multidisciplinary study conducted at the Cummins Technical Center in which a suite of instruments was deployed to yield comprehensive, temporally resolved information on the diesel exhaust particle loadings and properties in real-time: Particle size distributions were measured by Engine Exhaust Particle Sizer (EEPS) and Scanning Mobility Particle Sizer (SMPS). Total particle diameter concentration was obtained using Electrical Aerosol Detector (EAD). Laser Induced Incandescence and photoacoustic techniques were used to monitor the PM soot content. Single Particle Laser Ablation Time-of- flight Mass Spectrometer (SPLAT) provided the aerodynamic diameter and chemical composition of individual diesel exhaust particles. Measurements were conducted on a number of heavy duty diesel engines operated under variety of operating conditions, including FTP transient cycles, ramped-modal cycles and steady states runs. We have also characterized PM emissions during diesel particulate filter regeneration cycles. We will present a comparison of PM characteristics observed during identical cycles, but with and without the use of aftertreatment. A total of approximately 100,000 individual particles were sized and their composition characterized by SPLAT. The aerodynamic size distributions of the characterized particles were between 50 and 300 nm, depending on engine operating conditions and particle composition. We will show that while the drastically reduced diesel PM emissions often render the PM filter measurements inadequate due to organic vapor artifacts SPLAT demonstrated its capability to provide real-time information on size and composition of individual diesel exhaust particles as function of engine operating conditions with better than 1 minute resolution.

  16. NFLUX: a test of vertical nitrogen flux by diel migrant biota

    NASA Astrophysics Data System (ADS)

    Longhurst, A. R.; Bedo, A.; Harrison, W. G.; Head, E. J. H.; Horne, E. P.; Irwin, B.; Morales, C.

    1989-11-01

    At a station (NFLUX), occupied for 10 days in the northern Sargasso Sea, we assembled data to test the hypothesis that diel migrant biota in the open ocean induce a downward flux of dissolved inorganic nitrogen that is significant in relation to the passive flux under gravity of particulate organic nitrogen at the base on the photic zone. We founf taht NH 4+ excretion rates by day at depths below the photic zone were approximately 8% of particulate nitrogen flux obtained by a sediment trap array at the same depth. This figure is in the lower part of the range of values calculated previously for 10 published station data sets; we attribute this to the quite high rate of passive flux relative to primary production at the NFLUX station.

  17. Influence of frontal zones on the distribution of particulate matter and organic compounds in surface waters of the Atlantic and Southern Oceans

    NASA Astrophysics Data System (ADS)

    Nemirovskaya, I. A.; Lisitzin, A. P.; Kravchishina, M. D.; Redzhepova, Z. Yu.

    2015-10-01

    Particulate matter and organic compounds (chlorophyll, lipids, and hydrocarbons) were analyzed in surface waters along the routes of R/Vs Akademik Fedorov (cruise 32) and Akademik Treshnikov (cruise 2) in February-May of 2012 and 2014, respectively, in the course of the 57th and 59th Russian Antarctic expeditions. It was found that the frontal zones exert the primary influence on the concentrations of the mentioned components in the Southern Ocean and in the western part of the Atlantic Ocean. The supply of pollutants into the Eastern Atlantic Ocean on the shelf of the Iberian peninsula results in a pronounced increase in the concentrations of lipids and hydrocarbons causing local anthropogenic pollution zones.

  18. Spatial, temporal, and interspecies patterns in fine particulate matter in Texas.

    PubMed

    Gebhart, Kristi A; Malm, William C; Ashbaugh, Lowell L

    2005-11-01

    The Big Bend Regional Aerosol and Visibility Observational (BRAVO) field study was conducted from July to October 1999 and was followed by several years of modeling and data analyses to examine the causes of haze at Big Bend National Park TX (BBNP). During BRAVO, daily speciated fine (diameter <2.5 microm) particulate concentrations were measured at 37 sites throughout Texas. At the primary receptor site, K-Bar Ranch, there were many additional measurements including a "high-sensitivity" version of the 24-hr fine particulate elemental data. The spatial, temporal, and interspecies patterns in these data are examined here to qualitatively investigate source regions and source types influencing the fine particulate concentrations in Texas with an emphasis on sources of sulfates, the largest contributor to fine mass and light extinction. Peak values of particulate sulfur (S) varied spatially and seasonally. Maximum S was in Northeast Texas during the summer, whereas peak S at BBNP was in the fall. Sulfate acidity at BBNP also varied by month. Sources of Se were evident in Northeast Texas and from the Carbón I and II plants. High S episodes at BBNP during BRAVO had several different trace element characteristics. Carbon concentrations at BBNP during BRAVO were probably mostly urban-related, with arrival from the Houston area likely. The Houston artificial tracer released during the second half of BRAVO was highly correlated with some carbon fractions. There was evidence of the influence of African dust at sites throughout Texas during the summer. Patterns in several trace elements were also examined. Vanadium was associated with air masses from Mexico. Lead concentrations in southern Texas have dropped dramatically over the past several years.

  19. Particulate polycyclic aromatic hydrocarbon spatial variability and aging in Mexico City

    NASA Astrophysics Data System (ADS)

    Thornhill, D. A.; Herndon, S. C.; Onasch, T. B.; Wood, E. C.; Zavala, M.; Molina, L. T.; Gaffney, J. S.; Marley, N. A.; Marr, L. C.

    2007-11-01

    As part of the Megacities Initiative: Local and Global Research Observations (MILAGRO) study in the Mexico City Metropolitan Area in March 2006, we measured particulate polycyclic aromatic hydrocarbons (PAHs) and other gaseous species and particulate properties at six locations throughout the city. The measurements were intended to support the following objectives: to describe spatial and temporal patterns in PAH concentrations, to gain insight into sources and transformations of PAHs, and to quantify the relationships between PAHs and other pollutants. Total particulate PAHs at the Instituto Mexicano del Petróleo (T0 supersite) located near downtown averaged 50 ng m-3, and aerosol active surface area averaged 80 mm2 m-3. PAHs were also measured on board the Aerodyne Mobile Laboratory, which visited six sites encompassing a mixture of different land uses and a range of ages of air parcels transported from the city core. Weak intersite correlations suggest that local sources are important and variable and that exposure to PAHs cannot be represented by a single regional-scale value. The relationships between PAHs and other pollutants suggest that a variety of sources and ages of particles are present. Among carbon monoxide, nitrogen oxides (NOx), and carbon dioxide, particulate PAHs are most strongly correlated with NOx. Mexico City's PAH-to-black carbon mass ratio of 0.01 is similar to that found on a freeway loop in the Los Angeles area and approximately 8-30 times higher than that found in other cities. Ratios also indicate that primary combustion particles are rapidly coated by secondary aerosol in Mexico City. If so, the lifetime of PAHs may be prolonged if the coating protects them against photodegradation or heterogeneous reactions.

  20. Spatio-temporal Evolution of Velocity Structure, Concentration and Grain-size Stratification within Experimental Particulate Gravity Flows: Potential Input Parameters for Numerical Models

    NASA Astrophysics Data System (ADS)

    McCaffrey, W.; Choux, C.; Baas, J.; Haughton, P.

    2001-12-01

    Little is known about the combined spatio-temporal evolution of velocity structure, concentration and grain size stratification within particulate gravity currents. Yet these data are of primary importance for numerical model validation, prior to application to natural flows, such as pyroclastic density currents and turbidity currents. A comprehensive study was carried out on a series of experimental particulate gravity flows of 5% by volume initial concentration. The sediment analogue was polydisperse silica flour (mean grain size ~8 microns). A uniform 30 liter suspension was prepared in an overhead reservoir, then allowed to drain (in about one minute) into an flume 10 m long and 0.3 m wide, water-filled to a depth of 0.3 m. Each flow was siphoned continuously for 52 s at 5 different heights (spaced evenly from 0.6 to 4.6 cm) with samples collected at a frequency of 0.25Hz, generating 325 samples for grain-size and concentration analysis. Simultaneously, six 4-MHz UDVP (Ultrasonic Doppler Velocity Profiling) probes recorded the horizontal component of flow velocity. All but the highest probe were positioned at the same height as the siphons. The sampling location was shifted 1.32m down-current for each of five nominally identical flows, yielding sample locations at 1.32, 2.64, 3.96, 5.28 and 6.60m from the inlet point. These data can be combined to give both the temporal and spatial evolution of a single idealised flow. The concentration data can be used to defined the structure of the flow. The flow first propagated as a jet, then became stratified. The length of the head increased with increasing distance from the reservoir (although the head propagation velocity was uniform). The maximum concentration was located at the base of the flow towards the rear of the head. Grain-size analysis showed that the head was enriched in coarse particles even at the most distal sampling location. Distinct flow stratification developed at a distance between 1.3 m and 2.6 m from the reservoir. In the body of the current, the suspended sediment was normally graded, whereas the tail exhibited inverse grading. This inverse grading may be linked to coarse particles in the head being swept upwards and backwards, then falling back into the body of the current. Alternatively, body turbulence may inhibit the settling of coarse particles. Turbulence may also explain the presence of coarse particles in the flow's head, with turbulence intensity apparently correlated with the flow competence.

  1. Use of Pharmacotherapies in the Treatment of Alcohol Use Disorders and Opioid Dependence in Primary Care

    PubMed Central

    Lee, Jinhee; Kresina, Thomas F.; Campopiano, Melinda; Lubran, Robert; Clark, H. Westley

    2015-01-01

    Substance-related and addictive disorders are chronic relapsing conditions that substantially impact public health. Effective treatments for these disorders require addressing substance use/dependence comprehensively as well as other associated comorbidities. Comprehensive addressing of substance use in a medical setting involves screening for substance use, addressing substance use directly with the patient, and formulating an appropriate intervention. For alcohol dependence and opioid dependence, pharmacotherapies are available that are safe and effective when utilized in a comprehensive treatment paradigm, such as medication assisted treatment. In primary care, substance use disorders involving alcohol, illicit opioids, and prescription opioid abuse are common among patients who seek primary care services. Primary care providers report low levels of preparedness and confidence in identifying substance-related and addictive disorders and providing appropriate care and treatment. However, new models of service delivery in primary care for individuals with substance-related and addictive disorders are being developed to promote screening, care and treatment, and relapse prevention. The education and training of primary care providers utilizing approved medications for the treatment of alcohol use disorders and opioid dependence in a primary care setting would have important public health impact and reduce the burden of alcohol abuse and opioid dependence. PMID:25629034

  2. 76 FR 54004 - Agency Information Collection (Joint Application for Comprehensive Assistance and Support...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-30

    ... Application for Comprehensive Assistance and Support Services for Family Caregivers) Activity Under OMB Review... INFORMATION: Title: Joint Application for Comprehensive Assistance and Support Services for Family Caregivers... financial benefits under the Caregiver Program. Individuals designated as primary or secondary family...

  3. Decadal-scale export of nitrogen, phosphorus, and sediment from the Susquehanna River basin, USA: Analysis and synthesis of temporal and spatial patterns.

    PubMed

    Zhang, Qian; Ball, William P; Moyer, Douglas L

    2016-09-01

    The export of nitrogen (N), phosphorus (P), and suspended sediment (SS) is a long-standing management concern for the Chesapeake Bay watershed, USA. Here we present a comprehensive evaluation of nutrient and sediment loads over the last three decades at multiple locations in the Susquehanna River basin (SRB), Chesapeake's largest tributary watershed. Sediment and nutrient riverine loadings, including both dissolved and particulate fractions, have generally declined at all sites upstream of Conowingo Dam (non-tidal SRB outlet). Period-of-record declines in riverine yield are generally smaller than those in source input, suggesting the possibility of legacy contributions. Consistent with other watershed studies, these results reinforce the importance of considering lag time between the implementation of management actions and achievement of river quality improvement. Whereas flow-normalized loadings for particulate species have increased recently below Conowingo Reservoir, those for upstream sites have declined, thus substantiating conclusions from prior studies about decreased reservoir trapping efficiency. In regard to streamflow effects, statistically significant log-linear relationships between annual streamflow and annual constituent load suggest the dominance of hydrological control on the inter-annual variability of constituent export. Concentration-discharge relationships revealed general chemostasis and mobilization effects for dissolved and particulate species, respectively, both suggesting transport-limitation conditions. In addition to affecting annual export rates, streamflow has also modulated the relative importance of dissolved and particulate fractions, as reflected by its negative correlations with dissolved P/total P, dissolved N/total N, particulate P/SS, and total N/total P ratios. For land-use effects, period-of-record median annual yields of N, P, and SS all correlate positively with the area fraction of non-forested land but negatively with that of forested land under all hydrological conditions. Overall, this work has informed understanding with respect to four major factors affecting constituent export (i.e., source input, reservoir modulation, streamflow, and land use) and demonstrated the value of long-term river monitoring. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  4. Explaining Melting and Evaporation below Boiling Point. Can Software Help with Particle Ideas?

    ERIC Educational Resources Information Center

    Papageorgiou, George; Johnson, Philip; Fotiades, Fotis

    2008-01-01

    This paper reports the findings of a study exploring the use of a software package to help pupils understand particulate explanations for melting and evaporation below boiling point. Two matched classes in a primary school in Greece (ages 11-12, n = 16 and 19) were involved in a short intervention of six one hour lessons. Covering the same…

  5. Patterns in Stable Isotope Values of Nitrogen and Carbon in Particulate Matter from the Northwest Atlantic Continental Shelf, from the Gulf of Maine to Cape Hatteras

    EPA Science Inventory

    Stable isotope measurements of nitrogen and carbon (15N, 13ddC) are often used to characterize estuarine, nearshore, and open ocean ecosystems. Reliable information about the spatial distribution of base-level stable isotope values, often represented by primary producers, is crit...

  6. Investigating Students' Ability to Transfer Ideas Learned from Molecular Animations of the Dissolution Process

    ERIC Educational Resources Information Center

    Kelly, Resa M.; Jones, Loretta L.

    2008-01-01

    Animations of the particulate level of matter are widely available for use in chemistry classes and are often the primary means of representing molecular behavior. These animations may also be viewed by individual students using textbook Web sites, although without reinforcement or feedback. It is not known to what extent the material in these…

  7. Examination of Visuals about the Particulate Nature of Matter in Turkish Middle School Science Textbooks

    ERIC Educational Resources Information Center

    Kapici, Hasan Özgür; Savasci-Açikalin, Funda

    2015-01-01

    Textbooks are one of the primary teaching tools frequently used in schools and most teachers use them in their classrooms (Sanchez and Valcarcel, 1999). Since there are a lot of abstract concepts in science education, images in science textbooks play a vital role in the learning process (Kenan et al., 2011). Concretization of abstract concepts may…

  8. Effects of changes in nutrient loading and composition on hypoxia dynamics and internal nutrient cycling of a stratified coastal lagoon

    NASA Astrophysics Data System (ADS)

    Zhu, Yafei; McCowan, Andrew; Cook, Perran L. M.

    2017-10-01

    The effects of changes in catchment nutrient loading and composition on the phytoplankton dynamics, development of hypoxia and internal nutrient dynamics in a stratified coastal lagoon system (the Gippsland Lakes) were investigated using a 3-D coupled hydrodynamic biogeochemical water quality model. The study showed that primary production was equally sensitive to changed dissolved inorganic and particulate organic nitrogen loads, highlighting the need for a better understanding of particulate organic matter bioavailability. Stratification and sediment carbon enrichment were the main drivers for the hypoxia and subsequent sediment phosphorus release in Lake King. High primary production stimulated by large nitrogen loading brought on by a winter flood contributed almost all the sediment carbon deposition (as opposed to catchment loads), which was ultimately responsible for summer bottom-water hypoxia. Interestingly, internal recycling of phosphorus was more sensitive to changed nitrogen loads than total phosphorus loads, highlighting the potential importance of nitrogen loads exerting a control over systems that become phosphorus limited (such as during summer nitrogen-fixing blooms of cyanobacteria). Therefore, the current study highlighted the need to reduce both total nitrogen and total phosphorus for water quality improvement in estuarine systems.

  9. Biodegradation of potential diesel oxygenate additives: dibutyl maleate (DBM), and tripropylene glycol methyl ether (TGME).

    PubMed

    Marchetti, Alfredo A; Knize, Mark G; Chiarappa-Zucca, Marina L; Pletcher, Ronald J; Layton, David W

    2003-08-01

    The addition of oxygen-bearing compounds to diesel fuel considerably reduces particulate emissions. TGME and DBM have been identified as possible diesel additives based on their physicochemical characteristics and performance in engine tests. Although these compounds will reduce particulate emissions, their potential environmental impacts are unknown. As a means of characterizing their persistence in environmental media such as soil and groundwater, we conducted a series of biodegradation tests of DBM and TGME. Benzene and methyl tertiary butyl ether (MTBE) were also tested as reference compounds. Primary degradation of DBM fully occurred within 3 days, while TGME presented a lag phase of approximately 8 days and was not completely degraded by day 28. Benzene primary degradation occurred completely by day 3 and MTBE did not degrade at all. The total mineralized fractions of DBM and TGME achieved constant values as a function of time of approximately 65% and approximately 40%, respectively. Transport predictions show that, released to the environment, DBM and TGME would concentrate mostly in soils and waters with minimal impact to air. From an environmental standpoint, these results combined with the transport predictions indicate that DBM is a better choice than TGME as a diesel additive.

  10. Isolating the Meteorological Impact of 21st Century GHG Warming on the Removal and Atmospheric Loading of Anthropogenic Fine Particulate Matter Pollution at Global Scale

    NASA Astrophysics Data System (ADS)

    Xu, Yangyang; Lamarque, Jean-François

    2018-03-01

    Particulate matter with the diameter smaller than 2.5 μm (PM2.5) poses health threats to human population. Regardless of efforts to regulate the pollution sources, it is unclear how climate change caused by greenhouse gases (GHGs) would affect PM2.5 levels. Using century-long ensemble simulations with Community Earth System Model 1 (CESM1), we show that, if the anthropogenic emissions would remain at the level in the year 2005, the global surface concentration and atmospheric column burden of sulfate, black carbon, and primary organic carbon would still increase by 5%-10% at the end of 21st century (2090-2100) due to global warming alone. The decrease in the wet removal flux of PM2.5, despite an increase in global precipitation, is the primary cause of the increase in the PM2.5 column burden. Regionally over North America and East Asia, a shift of future precipitation toward more frequent heavy events contributes to weakened wet removal fluxes. Our results suggest climate change impact needs to be accounted for to define the future emission standards necessary to meet air quality standard.

  11. Satellite remote sensing of air quality in winter of Lanzhou

    NASA Astrophysics Data System (ADS)

    Wang, Dawei; Han, Tao; Jiang, Youyan; Li, Lili; Ren, Shuyuan

    2018-03-01

    Fine particulate matter (aerodynamic diameters of less than 2.5 μm, PM2.5) air pollution has become one of the global environmental problem, endangering the existence of residents living, climate, and public health. Estimation Particulate Matter (aerodynamic diameters of less than 10 μm, PM10) concentration and aerosol absorption was the key point in air quality and climate studies. In this study, we retrieve the Aerosol Optical Depth (AOD) from the Earth Observing System (EOS) and the Moderate Resolution Imaging Spectroradiometer (MODIS), and PM2.5, PM10 in winter on 2014 and 2015, using Extended Dense Dark Vegetation Algorithm and 6S radiation model to analysis the correlation. The result showed that at the condition of non-considering the influence of primary pollutants, the correlation of two Polynomials between aerosol optical depth and PM2.5 and PM10 was poor; taking the influence of the primary pollutants into consideration, the aerosol optical depth has a good correlation with PM2.5 and PM10. The version of PM10 by aerosol optical depth is higher than that of PM2.5, so the model can be used to realize the high precision inversion of winter PM10 in Lanzhou.

  12. Gold grade variation and particle microchemistry in exploration pits of the Batouri gold district, SE Cameroon

    NASA Astrophysics Data System (ADS)

    Vishiti, A.; Suh, C. E.; Lehmann, B.; Egbe, J. A.; Shemang, E. M.

    2015-11-01

    The Batouri area hosts lode-gold mineralization under several-m-thick lateritic cover. Pitting to bed rock on a geochemical Au anomaly defined from previous reconnaissance soil sampling identified five horizons ranging from saprock at the base to laterite at the top. Analysis of bulk samples from each horizon by fire assay shows that most of the horizons are barren although 119 ppb and 48 ppb Au values were obtained from one laterite horizon and one saprolite horizon, respectively, from two separate pits. All the horizons were panned and particulate gold was also recovered only from these two horizons. The gold grains from both horizons are morphologically and compositionally indistinguishable with rare quartz, pyrite and galena inclusions. The grains have irregular, sub-rounded, bean to elongated shapes and they show a remarkable core-rim zonation. Electron microprobe analysis of the grains recorded high gold content in the rims (86.3-100 wt%) and along fissures within the grains (95.1-100 wt%). The cores are relatively Ag rich (11.8-14 wt% Ag) while the rims (0.63-13.7 wt% Ag, most of the values fall within the lower limit of this range) and fissures (0.03-5.02 wt% Ag) are poor in Ag. The low Ag concentration in the rims and along fissures is attributed to preferential leaching of Ag; a process recognized in gold grains and platiniferous alloys from alluvia. The core composition of the grains is similar to that of primary gold composition in the bedrock. These results show that gold in the soil is relic particulate gold derived from the primary source with no evidence of secondary gold precipitation in the weathering cycle. In all the pits no horizon was systematically enriched in gold suggesting there has been no chemical remobilization of gold in this environment. Rather the dispersion of gold here is in the particulate form. Therefore combining particulate gold features with assay data is relevant to exploration in such tropical environments.

  13. Modeling Primary Productivity in the Margin Ice Zone from Glider-Based Measurements of Chlorophyll and Light during the 2014 Miz Program

    NASA Astrophysics Data System (ADS)

    Perry, M. J.; Lee, C.; Rainville, L.; Cetinic, I.; Yang, E. J.; Kang, S. H.

    2016-02-01

    In late summer 2014 during the Marginal Ice Zone (MIZ) Experiment, an international project sponsored by ONR, four Seagliders transited open water, through the marginal ice zone, and under ice-covered regions in the Beaufort Sea, penetrating as far as 100 km into the ice pack. The gliders navigated either by GPS in open water or, when under the ice, by acoustics from sound sources embedded in the MIZ autonomous observing array. The glider sensor suite included temperature, temperature microstructure, salinity, oxygen, chlorophyll fluorescence, optical backscatter, and multi-spectral downwelling irradiance. Cruises on the IBRV Araon operating in the open Beaufort Sea and on the R/V Ukpik and Norseman operating in continental shelf waters off Alaska's north slope allowed us to construct proxy libraries for converting chlorophyll fluorescence to chlorophyll concentration and optical backscatter to particulate organic carbon concentration. Water samples were collected for chlorophyll and particulate organic carbon analysis on the cruises and aligned with optical profiles of fluorescence and backscatter using sensors that were factory calibrated at the same time as the glider sensors. Fields of chlorophyll, particulate organic carbon, light, and primary productivity are constructed from the glider data. Productivity is modeled as a function of chlorophyll and light, using photosynthesis-light (PE) models with available PE parameters from Arctic measurements. During August the region under the ice was characterized by a deep chlorophyll maximum layer with low rates of production in overlying waters. A phytoplankton bloom developed in open water at the end of September, preceding the rapid reformation of ice, despite shorter days and reduce irradiation.

  14. Optimizing power cylinder lubrication on a large bore natural gas engine

    NASA Astrophysics Data System (ADS)

    Luedeman, Matthew R.

    More than 6000 integral compressors, located along America's natural gas pipelines, pump natural gas across the United States. These compressors are powered by 2-stroke, large bore natural gas burning engines. Lowering the operating costs, reducing the emissions, and ensuring that these engines remain compliant with future emission regulations are the drivers for this study. Substantial research has focused on optimizing efficiency and reducing the fuel derived emissions on this class of engine. However, significantly less research has focused on the effect and reduction of lubricating oil derived emissions. This study evaluates the impact of power cylinder lubricating oil on overall engine emissions with an emphasis on reducing oxidation catalyst poisoning. A traditional power cylinder lubricator was analyzed; power cylinder lubricating oil was found to significantly impact exhaust emissions. Lubricating oil was identified as the primary contributor of particulate matter production in a large bore natural gas engine. The particulate matter was determined to be primarily organic carbon, and most likely direct oil carryover of small oil droplets. The particulate matter production equated to 25% of the injected oil at a nominal power cylinder lubrication rate. In addition, power cylinder friction is considered the primary contributor to friction loss in the internal combustion engine. This study investigates the potential for optimizing power cylinder lubrication by controlling power cylinder injection to occur at the optimal time in the piston cycle. By injecting oil directly into the ring pack, it is believed that emissions, catalyst poisoning, friction, and wear can all be reduced. This report outlines the design and theory of two electronically controlled lubrication systems. Experimental results and evaluation of one of the systems is included.

  15. More comprehensive discussion of CRC screening associated with higher screening.

    PubMed

    Mosen, David M; Feldstein, Adrianne C; Perrin, Nancy A; Rosales, A Gabriella; Smith, David H; Liles, Elizabeth G; Schneider, Jennifer L; Meyers, Ronald E; Elston-Lafata, Jennifer

    2013-04-01

    Examine association of comprehensiveness of colorectal cancer (CRC) screening discussion by primary care physicians (PCPs) with completion of CRC screening. Observational study in Kaiser Permanente Northwest, a group-model health maintenance organization. A total of 883 participants overdue for CRC screening received an automated telephone call (ATC) between April and June 2009 encouraging CRC screening. Between January and March 2010, participants completed a survey on PCPs' discussion of CRC screening and patient beliefs regarding screening. receipt of CRC screening (assessed by electronic medical record [EMR], 9 months after ATC). Primary independent variable: comprehensiveness of CRC screening discussion by PCPs (7-item scale). Secondary independent variables: perceived benefits of screening (4-item scale assessing respondents' agreement with benefits of timely screening) and primary care utilization (EMR; 9 months after ATC). The independent association of variables with CRC screening was assessed with logistic regression. Average scores for comprehensiveness of CRC discussion and perceived benefits were 0.4 (range 0-1) and 4.0 (range 1-5), respectively. A total of 28.2% (n = 249) completed screening, 84% of whom had survey assessments after their screening date. Of screeners, 95.2% completed the fecal immunochemical test. More comprehensive discussion of CRC screening was associated with increased screening (odds ratio [OR] = 1.51, 95% confidence interval [CI] = 1.03-2.21). Higher perceived benefits (OR = 1.46, 95% CI = 1.13-1.90) and 1 or more PCP visits (OR = 5.82, 95% CI = 3.87-8.74) were also associated with increased screening. More comprehensive discussion of CRC screening was independently associated with increased CRC screening. Primary care utilization was even more strongly associated with CRC screening, irrespective of discussion of CRC screening.

  16. Stable isotope analysis of larval mosquito diets in agricultural wetlands in the coastal plain of Georgia, U.S.A.

    PubMed

    Young, Gina Botello; Golladay, Stephen; Covich, Alan; Blackmore, Mark

    2014-12-01

    Previous studies have used C and N isotope ratios to investigate the use of different food resources such as plant and animal detritus by container-breeding mosquitoes. This study is the first to report on the potential food resources assimilated by larval mosquitoes in agricultural and reference wetlands. Larval mosquitoes (Diptera: Culcidae) were sampled, along with their potential food resources, from agricultural and reference wetland habitats throughout a seasonal hydroperiod. IsoSource mixing model results indicated that food resources had greater δ(15) N isotope values in agricultural wetlands compared with cypress-gum swamps. In February, Aedes vexans (Meigen) and Culex territans Walker larvae fed primarily on lower quality food resources (coarse particulate organic matter and sediment) based on C:N. In contrast, higher quality food resources (fine particulate organic matter) were utilized by Anopheles spp. throughout the study and by Psorophora columbiae (Dyer and Knab) in May. This research contributes to a more comprehensive understanding of the food resources available and assimilated by larval mosquitoes in agricultural wetlands. © 2014 The Society for Vector Ecology.

  17. Quality-assurance procedures: Method 5G determination of particulate emissions from wood heaters from a dilution tunnel sampling location

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ward, T.E.; Hartman, M.W.; Olin, R.C.

    1989-06-01

    Quality-assurance procedures are contained in this comprehensive document intended to be used as an aid for wood-heater manufacturers and testing laboratories in performing particulate matter sampling of wood heaters according to EPA protocol, Method 5G. These procedures may be used in research and development, and as an aid in auditing and certification testing. A detailed, step-by-step quality assurance guide is provided to aid in the procurement and assembly of testing apparatus, to clearly describe the procedures, and to facilitate data collection and reporting. Suggested data sheets are supplied that can be used as an aid for both recordkeeping and certificationmore » applications. Throughout the document, activity matrices are provided to serve as a summary reference. Checklists are also supplied that can be used by testing personnel. Finally, for the purposes of ensuring data quality, procedures are outlined for apparatus operation, maintenance, and traceability. These procedures combined with the detailed description of the sampling and analysis protocol will help ensure the accuracy and reliability of Method 5G emission-testing results.« less

  18. A summary of the 2006 critical review - health effects of fine particulate air pollution: lines that connect

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    C. Arden Pope; Douglas Dockery

    2006-06-15

    In spite of continued gaps in knowledge, several important lines of research explored in the 2006 Critical Review in the Journal of the Air Waste Management Association, June 2006, pp 709-742 have substantially helped elucidate our understanding about human health effects of particulate air pollution. A comprehensive evaluation of the literature provides a compelling evidence that continued reductions in exposure to combustion-related fine particulate air pollution as indicated by PM 2.5 will result in improvements in cardiopulmonary health. Although research on the health effects of PM has been motivated largely by environmental health policy, in this review the progress ofmore » the science has been of more interest than debates over legally mandated standards. There has been substantial progress in the evaluation of the health effects of PM at different time-scales of exposure and in the exploration of the shape of the concentration-response function. The emerging evidence of PM-related cardiovascular health effects and the growing knowledge regarding inter connected general pahtophysiological pathways that link PM exposure with cardiopulmonary morbidity and mortality are fascinating results. These results have important scientific, medical, and public health implications that are much broader than debates over air quality Standard. Unsolved scientific issues dealing with the health effects of PM air pollution need not serve as sources of division, but as opportunities for cooperation and increased collaboration between epidemiology, toxicology, exposure assessment, and related disciplines. 40 refs., 4 figs.« less

  19. Characterization of Emissions and Residues from Simulations ...

    EPA Pesticide Factsheets

    The surface oil burns conducted by the U.S. Coast Guard from April to July 2010 during the Deepwater Horizon disaster in the Gulf of Mexico were simulated by small scale burns to characterize the pollutants, determine emission factors, and gather particulate matter for subsequent toxicity testing. A representative crude oil (Bayou Sweet) was burned in ocean-salinity seawater and emissions were collected from the plume by means of a crane-suspended emission sampling platform. A comprehensive array of emissions was characterized, accounting for over 92% by mass of the combustion products even without accounting for H2O. The particulate matter emissions were 70 g/kg (±8.3) of oil consumed, composed of 81% (±8) elemental carbon, and 80% were 1 µm in diameter or less. The particulate matter emissions were strongly light absorbing and had a single scattering albedo of 0.4 (±0.01) at 532 nm. Emissions of the 16 polycyclic aromatic hydrocarbons (PAHs) were approximately 1 g/kg of oil consumed. While the oil burn particles were highly PAH-enriched, less than 30% of the PAHs were particle-bound, the rest being in the gas phase. Formation of polychlorinated dibenzodioxin/dibenzofuran (PCDD/DF) was observed at 1.2 ng toxic equivalency (TEQ)/kg of oil consumed. Analysis of the particles showed the major elements to be Na, S, Cl and Si with no other elements, including metals, exceeding 5 mg/kg oil consumed. The unburned oil mass was 29% of the original crude oil mas

  20. Silicone-oil-based subvisible particles: their detection, interactions, and regulation in prefilled container closure systems for biopharmaceuticals.

    PubMed

    Felsovalyi, Flora; Janvier, Sébastien; Jouffray, Sébastien; Soukiassian, Hervé; Mangiagalli, Paolo

    2012-12-01

    Recent increased regulatory scrutiny concerning subvisible particulates (SbVPs) in parenteral formulations of biologics has led to the publication of numerous articles about the sources, characteristics, implications, and approaches to monitoring and detecting SbVPs. Despite varying opinions on the level of associated risks and method of regulation, nearly all industry scientists and regulators agree on the need for monitoring and reporting visible and subvisible particles. As prefillable drug delivery systems have become a prominent packaging option, silicone oil, a common primary packaging lubricant, may play a role in the appearance of particles. The goal of this article is to complement the current SbVP knowledge base with new insights into the evolution of silicone-oil-related particulates and their interactions with components in prefillable systems. We propose a "toolbox" for improved silicone-oil-related particulate detection and enumeration, and discuss the benefits and limitations of approaches for lowering and controlling silicone oil release in parenterals. Finally, we present surface cross-linking of silicone as the recommended solution for achieving significant SbVP reduction without negatively affecting functional performance. Copyright © 2012 Wiley Periodicals, Inc.

  1. Solidification of Magnesium (AM50A) / vol%. SiCp composite

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Hu, H.

    2012-01-01

    Magnesium matrix composite is one of the advanced lightweight materials with high potential to be used in automotive and aircraft industries due to its low density and high specific mechanical properties. The magnesium composites can be fabricated by adding the reinforcements of fibers or/and particles. In the previous literature, extensive studies have been performed on the development of matrix grain structure of aluminum-based metal matrix composites. However, there is limited information available on the development of grain structure during the solidification of particulate-reinforced magnesium. In this work, a 5 vol.% SiCp particulate-reinforced magnesium (AM50A) matrix composite (AM50A/SiCp) was prepared by stir casting. The solidification behavior of the cast AM50A/SiCp composite was investigated by computer-based thermal analysis. Optical and scanning electron microscopies (SEM) were employed to examine the occurrence of nucleation and grain refinement involved. The results indicate that the addition of SiCp particulates leads to a finer grain structure in the composite compared with the matrix alloy. The refinement of grain structure should be attributed to both the heterogeneous nucleation and the restricted primary crystal growth.

  2. Adjuvant activity of diesel-exhaust particulates for the production of IgE antibody in mice.

    PubMed

    Muranaka, M; Suzuki, S; Koizumi, K; Takafuji, S; Miyamoto, T; Ikemori, R; Tokiwa, H

    1986-04-01

    The prevalence rate of allergic rhinitis caused by pollen has strikingly increased in Japan in the last three decades. The number of diesel cars in use has also rapidly increased in the country. This fact urged us to study the effects of particulates emitted from diesel cars on the production of IgE antibody. The primary IgE antibody responses in mice immunized with intraperitoneal injection of ovalbumin (OA) mixed with diesel-exhaust particulates (DEP) were higher than those in the animals immunized with OA alone. This effect of DEP on the production of IgE antibody in mice was also demonstrated when mice were immunized with repeated injections of dinitrophenylated-OA. In addition, persistent IgE-antibody response to major allergen of Japanese cedar pollen (JCPA), a most common pollen causing allergic rhinitis in Japan, was observed in mice immunized with JCPA mixed with DEP but not in the animals immunized with JCPA alone. The results do indicate that the adjuvant activity of DEP can not be excluded as a possible cause of the associated change in the number of diesel cars and allergic rhinitis caused by pollen in Japan.

  3. Characterization of inhalable particulate matter, volatile organic compounds and other chemical species measured in urban areas in New Jersey—I. Summertime episodes

    NASA Astrophysics Data System (ADS)

    Lioy, Paul J.; Daisey, Joan M.; Reiss, Nathan M.; Harkov, Ronald

    The 1981 Summer Campaign results of the New Jersey Project on Airborne Toxic Elements and Organic Substances (ATEOS) have been examined for the accumulation of various pollutants during photochemical smog type episodes in Newark, Elizabeth and Camden, N.J. Background data were provided from a rural site in Ringwood, N.J. The interrelationships among inhalable particulate matter (IPM), particulate organic matter (POM), polycyclic aromatic hydrocarbons (PAH), SO 2-4, V, Pb, O 3, volatile organic compounds and alkylating agents are described. In addition, the prevailing synoptic meteorology was examined to characterize the episodes and define situations that significantly affected the accumulation patterns. The concentrations of PAH, toluene, benzene, V and Pb usually varied independently of the episodes indicating primary source contributions. The alkylating agent concentrations appeared to increase in association with episode periods. The results also indicated that 50-60% of the IPM mass in the urban areas was composed of the sum of SO 2-4 and POM. Between site analysis of the SO 2-4 indicated primarily a regional distribution pattern, while the POM appeared to be related to contributions from both local and regional sources.

  4. Reading Comprehension and Autism in the Primary General Education Classroom

    ERIC Educational Resources Information Center

    Nguyen, Neal Nghia; Leytham, Patrick; Schaefer Whitby, Peggy; Gelfer, Jeffrey I.

    2015-01-01

    Reading comprehension is a critical building block for effective early literacy development. Many students with autism spectrum disorder demonstrate difficulties in reading comprehension. These difficulties may be attributed to deficits in Theory of Mind, Weak Central Coherence, and Executive Functioning. Given the rise in the number of students…

  5. How Graphic Novels Support Reading Comprehension Strategy Development in Children

    ERIC Educational Resources Information Center

    Brenna, Beverley

    2013-01-01

    This qualitative case study explored the relationship between comprehension strategies and graphic novels in one Grade 4 classroom, utilising children as informants. The primary research questions related to children's applications of metacognitive reading comprehension strategies as well as the potential for graphic novels to support the…

  6. Particulate Emission Abatement for Krakow Boilerhouses

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    1998-09-14

    Environmental cleanup and pollution control are considered the foremost national priorities in Poland. The target of this cleanup is the Polish coal industry, which supplies the fuel to generate over 78% of Poland`s primary energy production. This project addresses the problem of airborne dust and uncontrolled particulate emissions from boilerhouses, which represent a large fraction of the total in Poland. In Krakow alone, there are numerous uncontrolled boilers accounting for about half the total fuel use. The large number of low-capacity boilers poses both technical and economic challenges, since the cost of control equipment is a significant factor in themore » reduction of emissions. A new concept in dust collection, called a Core Separator, is proposed for this important application. The Core Separator is an advanced technology developed through research sponsored by the Department of Energy.« less

  7. A Comparative Study of Listening Comprehension Measures in English as an Additional Language and Native English-Speaking Primary School Children

    ERIC Educational Resources Information Center

    McKendry, Mairead Grainne; Murphy, Victoria A.

    2011-01-01

    The aim of this study was to investigate the suitability of different measures of listening comprehension for Years 2, 3 and 4 children with English as an additional language (EAL). Non-standardised uses of reading comprehension measures are often employed as proxy measures of listening comprehension, i.e. for purposes for which they were not…

  8. Air quality risk management.

    PubMed

    Williams, Martin L

    2008-01-01

    Rather than attempt to provide a comprehensive account of air quality risk assessment, as might be found in a textbook or manual, this article discusses some issues that are of current importance in the United Kingdom and the rest of Europe, with special emphasis on risk assessment in the context of policy formulation, and emerging scientific knowledge. There are two pollutants of particular concern and that both pose challenges for risk assessment and policy, and they are particulate matter (PM) and ozone. The article describes some issues for health risk assessment and finally some forward-looking suggestions for future approaches to air quality management.

  9. Rural-to-Urban Migrants' Experiences with Primary Care under Different Types of Medical Institutions in Guangzhou, China

    PubMed Central

    Zeng, Jiazhi; Shi, Leiyu; Zou, Xia; Chen, Wen; Ling, Li

    2015-01-01

    Objectives China is facing the unprecedented challenge of rapidly increasing rural-to-urban migration. Migrants are in a vulnerable state when they attempt to access to primary care services. This study was designed to explore rural-to-urban migrants’ experiences in primary care, comparing their quality of primary care experiences under different types of medical institutions in Guangzhou, China. Methods The study employed a cross-sectional survey of 736 rural-to-urban migrants in Guangzhou, China in 2014. A validated Chinese version of Primary Care Assessment Tool—Adult Short Version (PCAT-AS), representing 10 primary care domains was used to collect information on migrants’ quality of primary care experiences. These domains include first contact (utilization), first contact (accessibility), ongoing care, coordination (referrals), coordination (information systems), comprehensiveness (services available), comprehensiveness (services provided), family-centeredness, community orientation and culturally competent. These measures were used to assess the quality of primary care performance as reported from patients’ perspective. Analysis of covariance was conducted for comparison on PCAT scores among migrants accessing primary care in tertiary hospitals, municipal hospitals, community health centers/community health stations, and township health centers/rural health stations. Multiple linear regression models were used to explore factors associated with PCAT total scores. Results After adjustments were made, migrants accessing primary care in tertiary hospitals (25.49) reported the highest PCAT total scores, followed by municipal hospitals (25.02), community health centers/community health stations (24.24), and township health centers/rural health stations (24.18). Tertiary hospital users reported significantly better performance in first contact (utilization), first contact (accessibility), coordination (information system), comprehensiveness (service available), and cultural competence. Community health center/community health station users reported significantly better experience in the community orientation domain. Township health center/rural health station users expressed significantly better experience in the ongoing care domain. There were no statistically significant differences across settings in the ongoing care, comprehensiveness (services provided), and family-centeredness domains. Multiple linear regression models showed that factors positively associated with higher PCAT total scores also included insurance covering parts of healthcare payment (P<0.001). Conclusions This study highlights the need for improvement in primary care provided by primary care institutions for rural-to-urban migrants. Relevant policies related to medical insurance should be implemented for providing affordable healthcare services for migrants accessing primary care. PMID:26474161

  10. Heterotrophic bacterial production and metabolic balance during the VAHINE mesocosm experiment in the New Caledonia lagoon

    NASA Astrophysics Data System (ADS)

    Van Wambeke, F.; Pfreundt, U.; Barani, A.; Berthelot, H.; Moutin, T.; Rodier, M.; Hess, W. R.; Bonnet, S.

    2015-12-01

    N2 fixation fuels ~ 50 % of new primary production in the oligotrophic South Pacific Ocean. The VAHINE mesocosm experiment designed to track the fate of diazotroph derived nitrogen (DDN) in the New Caledonia lagoon. Here, we examined the temporal dynamics of heterotrophic bacterial production during this experiment. Three replicate large-volume (~ 50 m3) mesocosms were deployed and were intentionally fertilized with dissolved inorganic phosphorus (DIP) to stimulate N2 fixation. We specifically examined relationships between N2 fixation rates and primary production, determined bacterial growth efficiency and established carbon budgets of the system from the DIP fertilization to the end of the experiment (days 5-23). Heterotrophic bacterioplankton production (BP) and alkaline phosphatase activity (APA) were statistically higher during the second phase of the experiment (P2: days 15-23), when chlorophyll biomass started to increase compared to the first phase (P1: days 5-14). Among autotrophs, Synechococcus abundances increased during P2, possibly related to its capacity to assimilate leucine and to produce alkaline phosphatase. Bacterial growth efficiency based on the carbon budget was notably higher than generally cited for oligotrophic environments (27-43 %), possibly due to a high representation of proteorhodopsin-containing organisms within the picoplanctonic community. The carbon budget showed that the main fate of gross primary production (particulate + dissolved) was respiration (67 %), and export through sedimentation (17 %). BP was highly correlated with particulate primary production and chlorophyll biomass during both phases of the experiment but slightly correlated, and only during P2 phase, with N2 fixation rates. Our results suggest that most of the DDN reached the heterotrophic bacterial community through indirect processes, like mortality, lysis and grazing.

  11. Proteome-wide changes in primary skin keratinocytes exposed to diesel particulate extract-A role for antioxidants in skin health.

    PubMed

    Rajagopalan, Pavithra; Jain, Ankit P; Nanjappa, Vishalakshi; Patel, Krishna; Mangalaparthi, Kiran K; Babu, Niraj; Cavusoglu, Nükhet; Roy, Nita; Soeur, Jeremie; Breton, Lionel; Pandey, Akhilesh; Gowda, Harsha; Chatterjee, Aditi; Misra, Namita

    2018-05-21

    Skin acts as a protective barrier against direct contact with pollutants but inhalation and systemic exposure have indirect effect on keratinocytes. Exposure to diesel exhaust has been linked to increased oxidative stress. To investigate global proteomic alterations in diesel particulate extract (DPE)/its vapor exposed skin keratinocytes. We employed Tandem Mass Tag (TMT)-based proteomics to study effect of DPE/DPE vapor on primary skin keratinocytes. We observed an increased expression of oxidative stress response protein NRF2, upon chronic exposure of primary keratinocytes to DPE/its vapor which includes volatile components such as polycyclic aromatic hydrocarbons (PAHs). Mass spectrometry-based quantitative proteomics led to identification 4490 proteins of which 201 and 374 proteins were significantly dysregulated (≥1.5 fold, p ≤ 0.05) in each condition, respectively. Proteins involved in cellular processes such as cornification (cornifin A), wound healing (antileukoproteinase) and differentiation (suprabasin) were significantly downregulated in primary keratinocytes exposed to DPE/DPE vapor. These results were corroborated in 3D skin models chronically exposed to DPE/DPE vapor. Bioinformatics analyses indicate that DPE and its vapor affect distinct molecular processes in skin keratinocytes. Components of mitochondrial oxidative phosphorylation machinery were seen to be exclusively overexpressed upon chronic DPE vapor exposure. In addition, treatment with an antioxidant like vitamin E partially restores expression of proteins altered upon exposure to DPE/DPE vapor. Our study highlights distinct adverse effects of chronic exposure to DPE/DPE vapor on skin keratinocytes and the potential role of vitamin E in alleviating adverse effects of environmental pollution. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  12. Plankton Production Biology

    DTIC Science & Technology

    2012-09-30

    understanding of the dynamics of the euphotic zone and the flux of particulate organic carbon (POC) into the mesopelagic (“twilight”) domain below. On p. 13...handicap of satellite-based estimates of the dynamics of primary production”. Moreover, at present we have little hope for predicting accurately from...will permit the study of stage-specific population dynamics (growth rate, production, mortality) of copepod larvae (nauplii) in mixed populations in the

  13. Strength of smoke-free air laws and indoor air quality.

    PubMed

    Lee, Kiyoung; Hahn, Ellen J; Robertson, Heather E; Lee, Seongjik; Vogel, Suzann L; Travers, Mark J

    2009-04-01

    Smoke-free air laws have been implemented in many Kentucky communities to protect the public from the harmful effects of secondhand smoke exposure. The impact of different strengths of smoke-free air laws on indoor air quality was assessed. Indoor air quality in hospitality venues was assessed in seven communities before and after comprehensive smoke-free air laws and in two communities only after partial smoke-free air laws. One community was measured three times: before any smoke-free air law, after the initial partial law, and after the law was strengthened to cover all workplaces and public places with few exemptions. Real-time measurements of particulate matters with 2.5 mum aerodynamic diameter or smaller (PM(2.5)) were obtained. When comprehensive smoke-free air laws were implemented, indoor PM(2.5) concentrations decreased significantly from 161 to 20 microg/m3. In one community that implemented a comprehensive smoke-free law after initially passing a partial law, indoor PM(2.5) concentrations were 304 microg/m3 before the law, 338 microg/m3 after the partial law, and 9 microg/m3 after the comprehensive law. The study clearly demonstrated that partial smoke-free air laws do not improve indoor air quality. A significant linear trend indicated that PM(2.5) levels in the establishments decreased with fewer numbers of burning cigarettes. Only comprehensive smoke-free air laws are effective in reducing indoor air pollution from secondhand tobacco smoke.

  14. Strength of smoke-free air laws and indoor air quality

    PubMed Central

    Hahn, Ellen J.; Robertson, Heather E.; Vogel, Suzann L.; Travers, Mark J.

    2009-01-01

    Introduction: Smoke-free air laws have been implemented in many Kentucky communities to protect the public from the harmful effects of secondhand smoke exposure. The impact of different strengths of smoke-free air laws on indoor air quality was assessed. Methods: Indoor air quality in hospitality venues was assessed in seven communities before and after comprehensive smoke-free air laws and in two communities only after partial smoke-free air laws. One community was measured three times: before any smoke-free air law, after the initial partial law, and after the law was strengthened to cover all workplaces and public places with few exemptions. Real-time measurements of particulate matters with 2.5 μm aerodynamic diameter or smaller (PM2.5) were obtained. Results: When comprehensive smoke-free air laws were implemented, indoor PM2.5 concentrations decreased significantly from 161 to 20 μg/m3. In one community that implemented a comprehensive smoke-free law after initially passing a partial law, indoor PM2.5 concentrations were 304 μg/m3 before the law, 338 μg/m3 after the partial law, and 9 μg/m3 after the comprehensive law. Discussion: The study clearly demonstrated that partial smoke-free air laws do not improve indoor air quality. A significant linear trend indicated that PM2.5 levels in the establishments decreased with fewer numbers of burning cigarettes. Only comprehensive smoke-free air laws are effective in reducing indoor air pollution from secondhand tobacco smoke. PMID:19346510

  15. Place and Policy: Secondhand Smoke Exposure in Bars and Restaurants.

    PubMed

    Buettner-Schmidt, Kelly; Boursaw, Blake; Lobo, Marie L

    2018-06-04

    Rural populations have been identified as having tobacco use disparities, with contributing factors including less demand for policy change than in urban areas, resulting in higher age-adjusted death rates related to tobacco use. In 2012, the rural state of North Dakota enacted a statewide comprehensive law requiring all bars and restaurants to be smoke-free. The purpose of this longitudinal study, performed in three phases, was to assess the continued effects of a statewide comprehensive smoke-free law in a primarily rural state, using a stratified random sample. Particulate matter and compliance indicators were assessed in restaurants and bars 21 months after enactment of the comprehensive law. Results were compared with the findings from the Phase 1 and Phase 2 samples, in which venues were assessed before passage of the law and approximately 3 months after enactment, respectively. The comprehensive, statewide, smoke-free law led to immediate, sustained, and substantial reductions in secondhand smoke and eliminated previous significant disparities in secondhand smoke exposure in rural communities. Although indoor smoke-free compliance with the law was generally high, compliance in required outdoor smoke-free areas was low. Compliance with signage requirements, both indoors and outdoors, was low. The comprehensive statewide smoke-free law created a just distribution of smoke-free laws statewide, resulting in increased protection of rural populations from secondhand smoke. Targeted public health interventions to address compliance may reduce secondhand smoke levels in outlier venues that continue to have high levels of secondhand smoke.

  16. Associations between Source-Specific Fine Particulate Matter and Emergency Department Visits for Respiratory Disease in Four U.S. Cities

    PubMed Central

    Krall, Jenna R.; Mulholland, James A.; Russell, Armistead G.; Balachandran, Sivaraman; Winquist, Andrea; Tolbert, Paige E.; Waller, Lance A.; Sarnat, Stefanie Ebelt

    2016-01-01

    Background: Short-term exposure to ambient fine particulate matter (PM2.5) concentrations has been associated with increased mortality and morbidity. Determining which sources of PM2.5 are most toxic can help guide targeted reduction of PM2.5. However, conducting multicity epidemiologic studies of sources is difficult because source-specific PM2.5 is not directly measured, and source chemical compositions can vary between cities. Objectives: We determined how the chemical composition of primary ambient PM2.5 sources varies across cities. We estimated associations between source-specific PM2.5 and respiratory disease emergency department (ED) visits and examined between-city heterogeneity in estimated associations. Methods: We used source apportionment to estimate daily concentrations of primary source-specific PM2.5 for four U.S. cities. For sources with similar chemical compositions between cities, we applied Poisson time-series regression models to estimate associations between source-specific PM2.5 and respiratory disease ED visits. Results: We found that PM2.5 from biomass burning, diesel vehicle, gasoline vehicle, and dust sources was similar in chemical composition between cities, but PM2.5 from coal combustion and metal sources varied across cities. We found some evidence of positive associations of respiratory disease ED visits with biomass burning PM2.5; associations with diesel and gasoline PM2.5 were frequently imprecise or consistent with the null. We found little evidence of associations with dust PM2.5. Conclusions: We introduced an approach for comparing the chemical compositions of PM2.5 sources across cities and conducted one of the first multicity studies of source-specific PM2.5 and ED visits. Across four U.S. cities, among the primary PM2.5 sources assessed, biomass burning PM2.5 was most strongly associated with respiratory health. Citation: Krall JR, Mulholland JA, Russell AG, Balachandran S, Winquist A, Tolbert PE, Waller LA, Sarnat SE. 2017. Associations between source-specific fine particulate matter and emergency department visits for respiratory disease in four U.S. cities. Environ Health Perspect 125:97–103; http://dx.doi.org/10.1289/EHP271 PMID:27315241

  17. Associations between Source-Specific Fine Particulate Matter and Emergency Department Visits for Respiratory Disease in Four U.S. Cities.

    PubMed

    Krall, Jenna R; Mulholland, James A; Russell, Armistead G; Balachandran, Sivaraman; Winquist, Andrea; Tolbert, Paige E; Waller, Lance A; Sarnat, Stefanie Ebelt

    2017-01-01

    Short-term exposure to ambient fine particulate matter (PM2.5) concentrations has been associated with increased mortality and morbidity. Determining which sources of PM2.5 are most toxic can help guide targeted reduction of PM2.5. However, conducting multicity epidemiologic studies of sources is difficult because source-specific PM2.5 is not directly measured, and source chemical compositions can vary between cities. We determined how the chemical composition of primary ambient PM2.5 sources varies across cities. We estimated associations between source-specific PM2.5 and respiratory disease emergency department (ED) visits and examined between-city heterogeneity in estimated associations. We used source apportionment to estimate daily concentrations of primary source-specific PM2.5 for four U.S. cities. For sources with similar chemical compositions between cities, we applied Poisson time-series regression models to estimate associations between source-specific PM2.5 and respiratory disease ED visits. We found that PM2.5 from biomass burning, diesel vehicle, gasoline vehicle, and dust sources was similar in chemical composition between cities, but PM2.5 from coal combustion and metal sources varied across cities. We found some evidence of positive associations of respiratory disease ED visits with biomass burning PM2.5; associations with diesel and gasoline PM2.5 were frequently imprecise or consistent with the null. We found little evidence of associations with dust PM2.5. We introduced an approach for comparing the chemical compositions of PM2.5 sources across cities and conducted one of the first multicity studies of source-specific PM2.5 and ED visits. Across four U.S. cities, among the primary PM2.5 sources assessed, biomass burning PM2.5 was most strongly associated with respiratory health. Citation: Krall JR, Mulholland JA, Russell AG, Balachandran S, Winquist A, Tolbert PE, Waller LA, Sarnat SE. 2017. Associations between source-specific fine particulate matter and emergency department visits for respiratory disease in four U.S. cities. Environ Health Perspect 125:97-103; http://dx.doi.org/10.1289/EHP271.

  18. BENCAL Cruise Report

    NASA Technical Reports Server (NTRS)

    Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Barlow, Ray; Sessions, Heather; Silulwane, Nonkqubela; Engel, Hermann; Aiken, James; Fishwick, James; Martinez-Vicente, Victor; Morel, Andre

    2003-01-01

    This report documents the scientific activities on board the South African Fisheries Research Ship (FRS) Africana during an ocean color calibration and validation cruise in the Benguela upwelling ecosystem (BEN-CAL), 4-17 October 2002. The cruise, denoted Afncana voyage 170, was staged in the southern Benguela between Cape Town and the Orange River within the region 14-18.5 deg E,29-34 deg S, with 15 scientists participat- ing from seven different international organizations. Uniquely in October 2002, four high-precision ocean color sensors were operational, and these included the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on the Aqua and Terra spacecraft, the Medium Resolution Imaging Spectrometer (MERIS), and the Sea-viewing Wide Field-of-view Sensor (SeaWiFS). SeaWiFS imagery was transmitted daily to the ship to assist in choosing the vessel's course and selecting stations for bio-optical deployments. There were four primary objectives of the cruise. The first was to conduct bio-optical measurements with above- and in-water optical instruments to vicariously calibrate the satellite sensors. The second was to interrelate diverse measurements of the apparent optical properties (AOPs) at satellite sensor wavelengths with inherent optical properties (IOPs) and bio-optically active constituents of seawater such as particles, pigments, and dissolved compounds. The third was to determine the interrelationships between optical properties, phytoplankton pigment composition, photosynthetic rates, and primary production, while the fourth objective was to collect samples for a second pigment round-robin intercalibration experiment. Weather conditions were generally very favorable, and a range of hyperspectral and fixed wavelength AOP instruments were deployed during daylight hours. Various IOP instruments were used to determine the absorption, attenuation, scattering, and backscattering properties of particulate matter and dissolved substances, while a Fast Repetition Rate Fluorometer (FRRF) was deployed to acquire data on phytoplankton photosynthetic activity. Hydrographic profiling was conducted routinely during the cruise, and seawater samples were collected for measurements of salinity, oxygen, inorganic nutrients, pigments, particulate organic carbon, suspended particulate material, and primary production. Location of stations and times of optical deployments were selected to coincide with satellite overpasses whenever possible, and to cover a large range in trophic conditions.

  19. Constraints on primary and secondary particulate carbon sources using chemical tracer and 14C methods during CalNex-Bakersfield

    NASA Astrophysics Data System (ADS)

    Sheesley, Rebecca J.; Nallathamby, Punith Dev; Surratt, Jason D.; Lee, Anita; Lewandowski, Michael; Offenberg, John H.; Jaoui, Mohammed; Kleindienst, Tadeusz E.

    2017-10-01

    The present study investigates primary and secondary sources of organic carbon for Bakersfield, CA, USA as part of the 2010 CalNex study. The method used here involves integrated sampling that is designed to allow for detailed and specific chemical analysis of particulate matter (PM) in the Bakersfield airshed. To achieve this objective, filter samples were taken during thirty-four 23-hr periods between 19 May and 26 June 2010 and analyzed for organic tracers by gas chromatography - mass spectrometry (GC-MS). Contributions to organic carbon (OC) were determined by two organic tracer-based techniques: primary OC by chemical mass balance and secondary OC by a mass fraction method. Radiocarbon (14C) measurements of the total organic carbon were also made to determine the split between the modern and fossil carbon and thereby constrain unknown sources of OC not accounted for by either tracer-based attribution technique. From the analysis, OC contributions from four primary sources and four secondary sources were determined, which comprised three sources of modern carbon and five sources of fossil carbon. The major primary sources of OC were from vegetative detritus (9.8%), diesel (2.3%), gasoline (<1.0%), and lubricating oil impacted motor vehicle exhaust (30%); measured secondary sources resulted from isoprene (1.5%), α-pinene (<1.0%), toluene (<1.0%), and naphthalene (<1.0%, as an upper limit) contributions. The average observed organic carbon (OC) was 6.42 ± 2.33 μgC m-3. The 14C derived apportionment indicated that modern and fossil components were nearly equivalent on average; however, the fossil contribution ranged from 32 to 66% over the five week campaign. With the fossil primary and secondary sources aggregated, only 25% of the fossil organic carbon could not be attributed. Whereas, nearly 80% of the modern carbon could not be attributed to primary and secondary sources accessible to this analysis, which included tracers of biomass burning, vegetative detritus and secondary biogenic carbon. The results of the current study contributes source-based evaluation of the carbonaceous aerosol at CalNex Bakersfield.

  20. Constraints on primary and secondary particulate carbon sources using chemical tracer and 14C methods during CalNex-Bakersfield

    PubMed Central

    Sheesley, Rebecca J.; Nallathamby, Punith Dev; Surratt, Jason D.; Lee, Anita; Lewandowski, Michael; Offenberg, John H.; Jaoui, Mohammed; Kleindienst, Tadeusz E.

    2018-01-01

    The present study investigates primary and secondary sources of organic carbon for Bakersfield, CA, USA as part of the 2010 CalNex study. The method used here involves integrated sampling that is designed to allow for detailed and specific chemical analysis of particulate matter (PM) in the Bakersfield airshed. To achieve this objective, filter samples were taken during thirty-four 23-hr periods between 19 May and 26 June 2010 and analyzed for organic tracers by gas chromatography – mass spectrometry (GC-MS). Contributions to organic carbon (OC) were determined by two organic tracer-based techniques: primary OC by chemical mass balance and secondary OC by a mass fraction method. Radiocarbon (14C) measurements of the total organic carbon were also made to determine the split between the modern and fossil carbon and thereby constrain unknown sources of OC not accounted for by either tracer-based attribution technique. From the analysis, OC contributions from four primary sources and four secondary sources were determined, which comprised three sources of modern carbon and five sources of fossil carbon. The major primary sources of OC were from vegetative detritus (9.8%), diesel (2.3%), gasoline (<1.0%), and lubricating oil impacted motor vehicle exhaust (30%); measured secondary sources resulted from isoprene (1.5%), α-pinene (<1.0%), toluene (<1.0%), and naphthalene (<1.0%, as an upper limit) contributions. The average observed organic carbon (OC) was 6.42 ± 2.33 μgC m−3. The 14C derived apportionment indicated that modern and fossil components were nearly equivalent on average; however, the fossil contribution ranged from 32-66% over the five week campaign. With the fossil primary and secondary sources aggregated, only 25% of the fossil organic carbon could not be attributed. Whereas, nearly 80% of the modern carbon could not be attributed to primary and secondary sources accessible to this analysis, which included tracers of biomass burning, vegetative detritus and secondary biogenic carbon. The results of the current study contributes source-based evaluation of the carbonaceous aerosol at CalNex Bakersfield. PMID:29681757

  1. Critical Reading Comprehension in an Era of Accountability

    ERIC Educational Resources Information Center

    Comber, Barbara; Nixon, Helen

    2011-01-01

    This paper argues for the need for critical reading comprehension in an era of accountability that often promotes reading comprehension as readily assessable through students answering multiple choice questions of unseen texts. Based upon a 1 year study investigating literacy in Years 4-9 the ways strong-performing primary schools develop serious…

  2. Reading Comprehension and Working Memory's Executive Processes: An Intervention Study in Primary School Students

    ERIC Educational Resources Information Center

    Garcia-Madruga, Juan A.; Elosua, Maria Rosa; Gil, Laura; Gomez-Veiga, Isabel; Vila, Jose Oscar; Orjales, Isabel; Contreras, Antonio; Rodriguez, Raquel; Melero, Maria Angeles; Duque, Gonzalo

    2013-01-01

    Reading comprehension is a highly demanding task that involves the simultaneous process of extracting and constructing meaning in which working memory's executive processes play a crucial role. In this article, a training program on working memory's executive processes to improve reading comprehension is presented and empirically tested in two…

  3. Spatially Modeling the Effects of Meteorological Drivers of PM2.5 in the Eastern United States via a Local Linear Penalized Quantile Regression Estimator.

    PubMed

    Russell, Brook T; Wang, Dewei; McMahan, Christopher S

    2017-08-01

    Fine particulate matter (PM 2.5 ) poses a significant risk to human health, with long-term exposure being linked to conditions such as asthma, chronic bronchitis, lung cancer, atherosclerosis, etc. In order to improve current pollution control strategies and to better shape public policy, the development of a more comprehensive understanding of this air pollutant is necessary. To this end, this work attempts to quantify the relationship between certain meteorological drivers and the levels of PM 2.5 . It is expected that the set of important meteorological drivers will vary both spatially and within the conditional distribution of PM 2.5 levels. To account for these characteristics, a new local linear penalized quantile regression methodology is developed. The proposed estimator uniquely selects the set of important drivers at every spatial location and for each quantile of the conditional distribution of PM 2.5 levels. The performance of the proposed methodology is illustrated through simulation, and it is then used to determine the association between several meteorological drivers and PM 2.5 over the Eastern United States (US). This analysis suggests that the primary drivers throughout much of the Eastern US tend to differ based on season and geographic location, with similarities existing between "typical" and "high" PM 2.5 levels.

  4. Description and evaluation of the Community Multiscale Air ...

    EPA Pesticide Factsheets

    The Community Multiscale Air Quality (CMAQ) model is a comprehensive multipollutant air quality modeling system developed and maintained by the US Environmental Protection Agency's (EPA) Office of Research and Development (ORD). Recently, version 5.1 of the CMAQ model (v5.1) was released to the public, incorporating a large number of science updates and extended capabilities over the previous release version of the model (v5.0.2). These updates include the following: improvements in the meteorological calculations in both CMAQ and the Weather Research and Forecast (WRF) model used to provide meteorological fields to CMAQ, updates to the gas and aerosol chemistry, revisions to the calculations of clouds and photolysis, and improvements to the dry and wet deposition in the model. Sensitivity simulations isolating several of the major updates to the modeling system show that changes to the meteorological calculations result in enhanced afternoon and early evening mixing in the model, periods when the model historically underestimates mixing. This enhanced mixing results in higher ozone (O3) mixing ratios on average due to reduced NO titration, and lower fine particulate matter (PM2. 5) concentrations due to greater dilution of primary pollutants (e.g., elemental and organic carbon). Updates to the clouds and photolysis calculations greatly improve consistency between the WRF and CMAQ models and result in generally higher O3 mixing ratios, primarily due to reduced

  5. Review of the Evidence from Epidemiology, Toxicology, and Lung Bioavailability on the Carcinogenicity of Inhaled Iron Oxide Particulates.

    PubMed

    Pease, Camilla; Rücker, Thomas; Birk, Thomas

    2016-03-21

    Since the iron-age and throughout the industrial age, humans have been exposed to iron oxides. Here, we review the evidence from epidemiology, toxicology, and lung bioavailability as to whether iron oxides are likely to act as human lung carcinogens. Current evidence suggests that observed lung tumors in rats result from a generic particle overload effect and local inflammation that is rat-specific under the dosing conditions of intratracheal instillation. This mode of action therefore, is not relevant to human exposure. However, there are emerging differences seen in vitro, in cell uptake and cell bioavailability between "bulk" iron oxides and "nano" iron oxides. "Bulk" particulates, as defined here, are those where greater than 70% are >100 nm in diameter. Similarly, "nano" iron oxides are defined in this context as particulates where the majority, usually >95% for pure engineered forms of primary particulates (not agglomerates), fall in the range 1-100 nm in diameter. From the weight of scientific evidence, "bulk" iron oxides are not genotoxic/mutagenic. Recent evidence for "nano" iron oxide is conflicting regarding genotoxic potential, albeit genotoxicity was not observed in an in vivo acute oral dose study, and "nano" iron oxides are considered safe and are being investigated for biomedical uses; there is no specific in vivo genotoxicity study on "nano" iron oxides via inhalation. Some evidence is available that suggests, hypothetically due to the larger surface area of "nano" iron oxide particulates, that toxicity could be exerted via the generation of reactive oxygen species (ROS) in the cell. However, the potential for ROS generation as a basis for explaining rodent tumorigenicity is only apparent if free iron from intracellular "nano" scale iron oxide becomes bioavailable at significant levels inside the cell. This would not be expected from "bulk" iron oxide particulates. Furthermore, human epidemiological evidence from a number of studies suggests that iron oxide is not a human carcinogen, and therefore, based upon the complete weight of evidence, we conclude that "bulk" iron oxides are not human carcinogens.

  6. Distribution and geochemical composition of suspended particulate material in the shallow embayment of northern Thermaikos Gulf, Greece

    NASA Astrophysics Data System (ADS)

    Tsompanoglou, K.; Anagnostou, Ch.; Krasakopoulou, E.; Pagou, K.; Karageorgis, A. P.; Pavlidou, A.; Albanakis, K.; Tsirambides, A.

    2017-07-01

    The distribution and the chemical composition of Suspended Particulate Matter (SPM), in the northern Thermaikos Gulf, were studied during an annual experiment, carried out from June 2004 to June 2005. Water samples were collected at three depths (1 m below surface, 10 m depth, and 2 m above bottom) and filtered to obtain SPM, particulate organic carbon (POC), total particulate nitrogen (PNtot) and particulate phosphorus (PP) concentrations. SPM and POC concentrations exhibited strong spatial and temporal variations, related to the different environmental characteristics in the study area such as river network, biological productivity, anthropogenic interferences, wind regime, and resuspension of the bottom sediments. The highest SPM concentrations were recorded at the surface (mean = 1.45 ± 0.75 mg/l, maximum value = 11.60 mg/l) and close to the bottom (mean = 1.49 ± 0.67 mg/l, maximum value = 11.72 mg/l), creating surface and bottom nepheloid layers (SNL and BNL), respectively. The maximum values were recorded close to the river mouths; the rivers are identified as the major sources of SPM. The Axios and Aliakmon rivers supplied the gulf with particulate matter, during the entire sampling period. Chemical analysis has revealed the significant correlation among the elements Al, Si, Fe, Ti, K, V, Mg and Ba suggesting the presence of terrigenous aluminosilicate minerals. Silica and Ca have terrigenous origin, but also come from autochthonous biogenic fraction. Chromium, Ni and Co, are of natural origin and derived from mafic and ultramafic rocks of the Axios and Aliakmon watersheds. Copper and Zn are correlated with each other and their distributions follow that of POC; these two metals are derived from partially treated domestic and industrial effluents. The vertical distribution of organic matter implies increased primary production within the upper layer of the water column. Phosphorus is present mainly in an organic form. During the sampling period, the water column was well-oxygenated. Early diagenesis only affected the concentrations of Mn and to a lesser extent Fe in the recently deposited seabed sediment.

  7. Exposure to airborne metals and particulate matter and risk for youth adjudicated for criminal activity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Haynes, Erin N., E-mail: Erin.Haynes@uc.edu; Chen, Aimin, E-mail: Aimin.Chen@uc.edu; Ryan, Patrick, E-mail: Patrick.Ryan@uc.edu

    Antisocial behavior is a product of multiple interacting sociohereditary variables, yet there is increasing evidence that metal exposure, particularly, manganese and lead, play a role in its epigenesis. Other metals, such as arsenic, cadmium, chromium, and mercury, and exposure to traffic-related air pollution, such as fine particulate matter ({<=}2.5 {mu}m) have been associated with neurological deficits, yet largely unexplored with respect to their relationship with delinquent behavior. The purpose of this study is to evaluate the ecological relationship between county-wide reported airborne emissions of air metals, particulate matter, and youth adjudicated for criminal activity. Metal exposure data were collected frommore » the Environmental Protection Agency AirData. Population statistics were obtained from the United States Census 2000 and adjudication data was obtained from the Courts of Common Pleases from each Ohio County. Simple correlations were calculated with the percentage of adjudications, all covariates, and estimated metal air emissions. Separate negative binomial regression models for each pollutant were used to provide an estimated risk ratio of pollutant emissions on the risk of adjudication for all Ohio counties adjusting for urban-rural residence, percentage of African Americans, median family income, percentage of family below poverty, percentage of high school graduation in 25 years and older populations, and population density. Metal emissions and PM in 1999 were all correlated with adjudication rate (2003-2005 average). Metal emissions were associated with slightly higher risk of adjudication, with about 3-4% increased risk per natural log unit of metal emission except chromium. The associations achieved statistical significance for manganese and mercury. The particulate matter {<=}2.5 and {<=}10 {mu}m emissions had a higher risk estimate, with 12% and 19% increase per natural log unit emission, respectively, and also achieved statistical significance. In summary, airborne exposure to manganese, mercury, and particulate matter are associated with increased risk of adjudication. Causality cannot be proven in observational studies such as this one, but the association warrants further examination in other research studies. Comprehensive epidemiologic investigations of metal exposure in pediatric populations should include social health outcomes, including measures of delinquent or criminal activity. Furthermore, the influence of metals on the neurotoxic pathway leading to delinquent activity should be further explored. - Highlights: Black-Right-Pointing-Pointer We evaluate the relationship between air pollutants and adjudication. Black-Right-Pointing-Pointer Manganese, mercury, and particulate matter are associated with risk of adjudication. Black-Right-Pointing-Pointer Further research of metal exposure should include social health outcomes.« less

  8. Implications of the Differential Toxicological Effects of III-V Ionic and Particulate Materials for Hazard Assessment of Semiconductor Slurries.

    PubMed

    Jiang, Wen; Lin, Sijie; Chang, Chong Hyun; Ji, Zhaoxia; Sun, Bingbing; Wang, Xiang; Li, Ruibin; Pon, Nanetta; Xia, Tian; Nel, André E

    2015-12-22

    Because of tunable band gaps, high carrier mobility, and low-energy consumption rates, III-V materials are attractive for use in semiconductor wafers. However, these wafers require chemical mechanical planarization (CMP) for polishing, which leads to the generation of large quantities of hazardous waste including particulate and ionic III-V debris. Although the toxic effects of micron-sized III-V materials have been studied in vivo, no comprehensive assessment has been undertaken to elucidate the hazardous effects of submicron particulates and released III-V ionic components. Since III-V materials may contribute disproportionately to the hazard of CMP slurries, we obtained GaP, InP, GaAs, and InAs as micron- (0.2-3 μm) and nanoscale (<100 nm) particles for comparative studies of their cytotoxic potential in macrophage (THP-1) and lung epithelial (BEAS-2B) cell lines. We found that nanosized III-V arsenides, including GaAs and InAs, could induce significantly more cytotoxicity over a 24-72 h observation period. In contrast, GaP and InP particulates of all sizes as well as ionic GaCl3 and InCl3 were substantially less hazardous. The principal mechanism of III-V arsenide nanoparticle toxicity is dissolution and shedding of toxic As(III) and, to a lesser extent, As(V) ions. GaAs dissolves in the cell culture medium as well as in acidifying intracellular compartments, while InAs dissolves (more slowly) inside cells. Chelation of released As by 2,3-dimercapto-1-propanesulfonic acid interfered in GaAs toxicity. Collectively, these results demonstrate that III-V arsenides, GaAs and InAs nanoparticles, contribute in a major way to the toxicity of III-V materials that could appear in slurries. This finding is of importance for considering how to deal with the hazard potential of CMP slurries.

  9. Estimating the impact of the 2004 Alaskan forest fires on episodic particulate matter pollution over the eastern United States through assimilation of satellite-derived aerosol optical depths in a regional air quality model

    NASA Astrophysics Data System (ADS)

    Mathur, Rohit

    2008-09-01

    During the summer of 2004, extensive wildfires burned in Alaska and western Canada; the fires were the largest on record for Alaska. Smoke from these fires was observed over the continental United States in satellite images, and a variety of chemical tracers associated with the fires were sampled by aircrafts deployed during the International Consortium for Atmospheric Research on Transport and Transformation field experiment. Several recent studies have quantified the impacts of the long-range transport of pollution associated with these fires on tropospheric CO and O3 levels over the eastern United States. This study quantifies the episodic impact of this pollution transport event on surface-level fine particulate matter (PM2.5) concentrations over the eastern United States during mid-July 2004, through the complementary use of remotely sensed, aloft, and surface measurements, in conjunction with a comprehensive regional atmospheric chemistry-transport model. A methodology is developed to assimilate MODIS aerosol optical depths in the model to represent the impacts of the fires. The resultant model predictions of CO and PM2.5 distributions are compared extensively with corresponding surface and aloft measurements. On the basis of the model calculations, a 0.12Tg enhancement in tropospheric PM2.5 mass loading over the eastern United States is estimated on 19 July 2004 due to the fires. This amount is significantly larger (approximately a factor of 8) than the total daily anthropogenic fine particulate matter emissions for the continental United States. Analysis of measured and modeled PM2.5 surface-level concentrations suggests that the transport of particulate matter pollution associated with the fires resulted in a 24-42 % enhancement in median surface-level PM2.5 concentrations across the eastern United States during 19-23 July 2004.

  10. Organic speciation of size-segregated atmospheric particulate matter

    NASA Astrophysics Data System (ADS)

    Tremblay, Raphael

    Particle size and composition are key factors controlling the impacts of particulate matter (PM) on human health and the environment. A comprehensive method to characterize size-segregated PM organic content was developed, and evaluated during two field campaigns. Size-segregated particles were collected using a cascade impactor (Micro-Orifice Uniform Deposit Impactor) and a PM2.5 large volume sampler. A series of alkanes and polycyclic aromatic hydrocarbons (PAHs) were solvent extracted and quantified using a gas chromatograph coupled with a mass spectrometer (GC/MS). Large volume injections were performed using a programmable temperature vaporization (PTV) inlet to lower detection limits. The developed analysis method was evaluated during the 2001 and 2002 Intercomparison Exercise Program on Organic Contaminants in PM2.5 Air Particulate Matter led by the US National Institute of Standards and Technology (NIST). Ambient samples were collected in May 2002 as part of the Tampa Bay Regional Atmospheric Chemistry Experiment (BRACE) in Florida, USA and in July and August 2004 as part of the New England Air Quality Study - Intercontinental Transport and Chemical Transformation (NEAQS - ITCT) in New Hampshire, USA. Morphology of the collected particles was studied using scanning electron microscopy (SEM). Smaller particles (one micrometer or less) appeared to consist of solid cores surrounded by a liquid layer which is consistent with combustion particles and also possibly with particles formed and/or coated by secondary material like sulfate, nitrate and secondary organic aerosols. Source apportionment studies demonstrated the importance of stationary sources on the organic particulate matter observed at these two rural sites. Coal burning and biomass burning were found to be responsible for a large part of the observed PAHs during the field campaigns. Most of the measured PAHs were concentrated in particles smaller than one micrometer and linked to combustion sources. The presence of known carcinogenic PAHs in the respirable particles has strong importance for human health. Recommendations for method improvements and further studies are included.

  11. An LES-PBE-PDF approach for modeling particle formation in turbulent reacting flows

    NASA Astrophysics Data System (ADS)

    Sewerin, Fabian; Rigopoulos, Stelios

    2017-10-01

    Many chemical and environmental processes involve the formation of a polydispersed particulate phase in a turbulent carrier flow. Frequently, the immersed particles are characterized by an intrinsic property such as the particle size, and the distribution of this property across a sample population is taken as an indicator for the quality of the particulate product or its environmental impact. In the present article, we propose a comprehensive model and an efficient numerical solution scheme for predicting the evolution of the property distribution associated with a polydispersed particulate phase forming in a turbulent reacting flow. Here, the particulate phase is described in terms of the particle number density whose evolution in both physical and particle property space is governed by the population balance equation (PBE). Based on the concept of large eddy simulation (LES), we augment the existing LES-transported probability density function (PDF) approach for fluid phase scalars by the particle number density and obtain a modeled evolution equation for the filtered PDF associated with the instantaneous fluid composition and particle property distribution. This LES-PBE-PDF approach allows us to predict the LES-filtered fluid composition and particle property distribution at each spatial location and point in time without any restriction on the chemical or particle formation kinetics. In view of a numerical solution, we apply the method of Eulerian stochastic fields, invoking an explicit adaptive grid technique in order to discretize the stochastic field equation for the number density in particle property space. In this way, sharp moving features of the particle property distribution can be accurately resolved at a significantly reduced computational cost. As a test case, we consider the condensation of an aerosol in a developed turbulent mixing layer. Our investigation not only demonstrates the predictive capabilities of the LES-PBE-PDF model but also indicates the computational efficiency of the numerical solution scheme.

  12. Literacy in Early Childhood and Primary Education: Issues, Challenges, Solutions

    ERIC Educational Resources Information Center

    McLachlan, Claire; Nicholson, Tom; Fielding-Barnsley, Ruth; Mercer, Louise; Ohi, Sarah

    2012-01-01

    Literacy in Early Childhood and Primary Education provides a comprehensive introduction to literacy teaching and learning. The book explores the continuum of literacy learning and children's transitions from early childhood settings to junior primary classrooms and then to senior primary and beyond. Reader-friendly and accessible, this book equips…

  13. The Contribution of Segmental and Suprasegmental Phonology to Reading Comprehension

    PubMed Central

    Veenendaal, Nathalie J.; Groen, Margriet A.; Verhoeven, Ludo

    2016-01-01

    The aim of the present study was to examine the relation between decoding and segmental and suprasegmental phonology, and their contribution to reading comprehension, in the upper primary grades. Following a longitudinal design, the performance of 99 Dutch primary school children on phonological awareness (segmental phonology) and text reading prosody (suprasegmental phonology) in fourth-grade and fifth-grade, and reading comprehension in sixth-grade were examined. In addition, decoding efficiency as a general assessment of reading was examined. Structural path modeling firstly showed that the relation between decoding efficiency and both measures of phonology from fourth- to fifth grade was unidirectional. Secondly, the relation between decoding in fourth- and fifth-grade and reading comprehension in sixth-grade became indirect when segmental and suprasegmental phonology were added to the model. Both factors independently exerted influence on later reading comprehension. This leads to the conclusion that not only segmental, but also suprasegmental phonology, contributes substantially to children's reading development. PMID:27551159

  14. Student Comprehension of Primary Literature is Aided by Companion Assignments Emphasizing Pattern Recognition and Information Literacy

    ERIC Educational Resources Information Center

    Shannon, Sarah; Winterman, Brian

    2012-01-01

    Primary literature is our main mode of communication in the sciences. As such, it is important for our undergraduates in the discipline to learn how to read primary literature. Incorporating primary literature into undergraduate science courses is often difficult because students are unprepared to comprehend primary articles. Learning to read and…

  15. Monitoring of atmospheric gaseous and particulate polycyclic aromatic hydrocarbons in South African platinum mines utilising portable denuder sampling with analysis by thermal desorption-comprehensive gas chromatography-mass spectrometry.

    PubMed

    Geldenhuys, G; Rohwer, E R; Naudé, Y; Forbes, P B C

    2015-02-06

    Concentrations of diesel particulate matter and polycyclic aromatic hydrocarbons (PAHs) in platinum mine environments are likely to be higher than in ambient air due to the use of diesel machinery in confined environments. Airborne PAHs may be present in gaseous or particle phases each of which has different human health impacts due to their ultimate fate in the body. Here we report on the simultaneous sampling of both phases of airborne PAHs for the first time in underground platinum mines in South Africa, which was made possible by employing small, portable denuder sampling devices consisting of two polydimethylsiloxane (PDMS) multi-channel traps connected in series separated by a quartz fibre filter, which only require small, battery operated portable personal sampling pumps for air sampling. Thermal desorption coupled with comprehensive gas chromatography-mass spectrometry (TD-GC×GC-TofMS) was used to analyse denuder samples taken in three different platinum mines. The samples from a range of underground environments revealed that PAHs were predominantly found in the gas phase with naphthalene and mono-methylated naphthalene derivatives being detected at the highest concentrations ranging from 0.01 to 18 μg m(-3). The particle bound PAHs were found in the highest concentrations at the idling load haul dump vehicle exhausts with a dominance of fluoranthene and pyrene. Particle associated PAH concentrations ranged from 0.47 to 260 ng m(-3) and included benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene and benzo[ghi]perylene. This work highlights the need to characterise both phases in order to assess occupational exposure to PAHs in this challenging sampling environment. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Using Higher Order Cognitive Questions in the Primary Classroom To Improve Comprehension.

    ERIC Educational Resources Information Center

    Coolidge, Susan W.

    A teaching team leader and second grade teacher designed and implemented a 10-week practicum intervention meant to improve the inferential comprehension of 105 second graders whose reading scores on the Ginn Mastery Tests revealed a gap between inferential and literal comprehension. It was reasoned that the gap would decrease if teachers were…

  17. Caring Prescriptions: Comprehensive Health Care Strategies for Young Children in Poverty.

    ERIC Educational Resources Information Center

    Bell, Karen N.; Simkin, Linda S.

    This report examines how communities and groups can shape the content of health services to bring more comprehensive health services to poor children and families. The report is based on a study of 11 comprehensive primary care programs and systems some of which offer school-based services: 4 freestanding community-based programs, 4 local systems…

  18. The Role of Structured Cooperative Learning Groups for Enhancing Chinese Primary Students' Reading Comprehension

    ERIC Educational Resources Information Center

    Law, Yin-Kum

    2014-01-01

    The present study aimed to compare the effectiveness of two types of cooperative learning groups used in reciprocal teaching (RT) classes (i.e. high-structured vs. low-structured groups) for enhancing students' reading comprehension. The participants were 235 Hong Kong Chinese Grade 6 students in nine classes. Reading comprehension tests and…

  19. Prolonged Particulate Hexavalent Chromium Exposure Suppresses Homologous Recombination Repair in Human Lung Cells

    PubMed Central

    Browning, Cynthia L.; Qin, Qin; Kelly, Deborah F.; Prakash, Rohit; Vanoli, Fabio; Jasin, Maria

    2016-01-01

    Abstract Genomic instability is one of the primary models of carcinogenesis and a feature of almost all cancers. Homologous recombination (HR) repair protects against genomic instability by maintaining high genomic fidelity during the repair of DNA double strand breaks. The defining step of HR repair is the formation of the Rad51 nucleofilament, which facilitates the search for a homologous sequence and invasion of the template DNA strand. Particulate hexavalent chromium (Cr(VI)), a human lung carcinogen, induces DNA double strand breaks and chromosome instability. Since the loss of HR repair increases Cr(VI)-induced chromosome instability, we investigated the effect of extended Cr(VI) exposure on HR repair. We show acute (24 h) Cr(VI) exposure induces a normal HR repair response. In contrast, prolonged (120 h) exposure to particulate Cr(VI) inhibited HR repair and Rad51 nucleofilament formation. Prolonged Cr(VI) exposure had a profound effect on Rad51, evidenced by reduced protein levels and Rad51 mislocalization to the cytoplasm. The response of proteins involved in Rad51 nuclear import and nucleofilament formation displayed varying responses to prolonged Cr(VI) exposure. BRCA2 formed nuclear foci after prolonged Cr(VI) exposure, while Rad51C foci formation was suppressed. These results suggest that particulate Cr(VI), a major chemical carcinogen, inhibits HR repair by targeting Rad51, causing DNA double strand breaks to be repaired by a low fidelity, Rad51-independent repair pathway. These results further enhance our understanding of the underlying mechanism of Cr(VI)-induced chromosome instability and thus, carcinogenesis. PMID:27449664

  20. Risk of lung cancer according to mild steel and stainless steel welding.

    PubMed

    Sørensen, Anita Rath; Thulstrup, Ane Marie; Hansen, Johnni; Ramlau-Hansen, Cecilia Høst; Meersohn, Andrea; Skytthe, Axel; Bonde, Jens Peter

    2007-10-01

    Whether the elevated risk of lung cancer observed among welders is caused by welding emissions or by confounding from smoking or asbestos exposure is still not resolved. This question was addressed in a cohort with a long follow-up and quantified estimates of individual exposure to welding fume particulates. Male metal workers employed at least 1 year at one or more Danish stainless or mild steel industrial companies from 1964 through 1984 were enrolled in a cohort. Data on occupational and smoking history were obtained by questionnaire in 1986. Welders in the cohort who started welding in 1960 or later (N=4539) were followed from April 1968 until December 2003, when information on cancer diagnosis was obtained from the Danish Cancer Registry. During the follow-up, 75 cases of primary lung cancer were identified. Lifetime accumulated exposure to welding fume particulates was estimated by combining questionnaire information and more than 1000 welding-process-specific measurements of fume particulates in the Danish welding industry. The standardized incidence ratio (SIR) for lung cancer was increased among the welders [SIR 1.35, 95% confidence interval (95% CI) 1.06-1.70)]. Among the stainless steel welders, the risk increased significantly with increasing accumulative welding particulate exposure, while no exposure-response relation was found for mild steel welders, even after adjustment for tobacco smoking and asbestos exposure. The study corroborates earlier findings that welders have an increased risk of lung cancer. While exposure-response relations indicate carcinogenic effects related to stainless steel welding, it is still unresolved whether the mild steel welding process carries a carcinogenic risk.

  1. Integrin-directed modulation of macrophage responses to biomaterials.

    PubMed

    Zaveri, Toral D; Lewis, Jamal S; Dolgova, Natalia V; Clare-Salzler, Michael J; Keselowsky, Benjamin G

    2014-04-01

    Macrophages are the primary mediator of chronic inflammatory responses to implanted biomaterials, in cases when the material is either in particulate or bulk form. Chronic inflammation limits the performance and functional life of numerous implanted medical devices, and modulating macrophage interactions with biomaterials to mitigate this response would be beneficial. The integrin family of cell surface receptors mediates cell adhesion through binding to adhesive proteins nonspecifically adsorbed onto biomaterial surfaces. In this work, the roles of integrin Mac-1 (αMβ2) and RGD-binding integrins were investigated using model systems for both particulate and bulk biomaterials. Specifically, the macrophage functions of phagocytosis and inflammatory cytokine secretion in response to a model particulate material, polystyrene microparticles were investigated. Opsonizing proteins modulated microparticle uptake, and integrin Mac-1 and RGD-binding integrins were found to control microparticle uptake in an opsonin-dependent manner. The presence of adsorbed endotoxin did not affect microparticle uptake levels, but was required for the production of inflammatory cytokines in response to microparticles. Furthermore, it was demonstrated that integrin Mac-1 and RGD-binding integrins influence the in vivo foreign body response to a bulk biomaterial, subcutaneously implanted polyethylene terephthalate. A thinner foreign body capsule was formed when integrin Mac-1 was absent (~30% thinner) or when RGD-binding integrins were blocked by controlled release of a blocking peptide (~45% thinner). These findings indicate integrin Mac-1 and RGD-binding integrins are involved and may serve as therapeutic targets to mitigate macrophage inflammatory responses to both particulate and bulk biomaterials. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. "Smoke": Characterization Of Smoke Particulate For Spacecraft Fire Detection

    NASA Technical Reports Server (NTRS)

    Urban, David L.; Mulholland, George W.; Yang, Jiann; Cleary, Thomas G.; Yuan, Zeng-Guang

    2003-01-01

    The "Smoke" experiment is a flight definition investigation that seeks to increase our understanding of spacecraft fire detection through measurements of particulate size distributions of preignition smokes from typical spacecraft materials. Owing to the catastrophic risk posed by even a very small fire in a spacecraft, the design goal for spacecraft fire detection is to detect the fire as quickly as possible, preferably in the preignition phase before a real flaming fire has developed. Consequently the target smoke for detection is typically not soot (typical of established hydrocarbon fires) but instead, pyrolysis products, and recondensed polymer particles. At the same time, false alarms are extremely costly as the crew and the ground team must respond quickly to every alarm. The U.S. Space Shuttle (STS: Space Transportation System) and the International Space Station (ISS) both use smoke detection as the primary means of fire detection. These two systems were designed in the absence of any data concerning low-gravity smoke particle (and background dust) size distributions. The STS system uses an ionization detector coupled with a sampling pump and the ISS system is a forward light scattering detector operating in the near IR. These two systems have significantly different sensitivities with the ionization detector being most sensitive (on a mass concentration basis) to smaller particulate and the light scattering detector being most sensitive to particulate that is larger than 1 micron. Since any smoke detection system has inherent size sensitivity characteristics, proper design of future smoke detection systems will require an understanding of the background and alarm particle size distributions that can be expected in a space environment.

  3. Gaseous and particulate emissions from prescribed burning in Georgia.

    PubMed

    Lee, Sangil; Baumann, Karsten; Schauer, James J; Sheesley, Rebecca J; Naeher, Luke P; Meinardi, Simone; Blake, Donald R; Edgerton, Eric S; Russell, Armistead G; Clements, Mark

    2005-12-01

    Prescribed burning is a significant source of fine particulate matter (PM2.5) in the southeastern United States. However, limited data exist on the emission characteristics from this source. Various organic and inorganic compounds both in the gas and particle phase were measured in the emissions of prescribed burnings conducted at two pine-dominated forest areas in Georgia. The measurements of volatile organic compounds (VOCs) and PM2.5 allowed the determination of emission factors for the flaming and smoldering stages of prescribed burnings. The VOC emission factors from smoldering were distinctly higher than those from flaming except for ethene, ethyne, and organic nitrate compounds. VOC emission factors show that emissions of certain aromatic compounds and terpenes such as alpha and beta-pinenes, which are important precursors for secondary organic aerosol (SOA), are much higher from active prescribed burnings than from fireplace wood and laboratory open burning studies. Levoglucosan is the major particulate organic compound (POC) emitted for all these studies, though its emission relative to total organic carbon (mg/g OC) differs significantly. Furthermore, cholesterol, an important fingerprint for meat cooking, was observed only in our in situ study indicating a significant release from the soil and soil organisms during open burning. Source apportionment of ambient primary fine particulate OC measured at two urban receptor locations 20-25 km downwind yields 74 +/- 11% during and immediately after the burns using our new in situ profile. In comparison with the previous source profile from laboratory simulations, however, this OC contribution is on average 27 +/- 5% lower.

  4. Semi-coke briquettes: towards reducing emissions of primary PM2.5, particulate carbon, and carbon monoxide from household coal combustion in China

    NASA Astrophysics Data System (ADS)

    Li, Qing; Li, Xinghua; Jiang, Jingkun; Duan, Lei; Ge, Su; Zhang, Qi; Deng, Jianguo; Wang, Shuxiao; Hao, Jiming

    2016-01-01

    Direct household use of unprocessed raw coals for cooking and heating without any air pollution control device has caused serious indoor and outdoor environment problems by emitting particulate matter (PM) and gaseous pollutants. This study examined household emission reduction by switching from unprocessed bituminous and anthracite coals to processed semi-coke briquettes. Two typical stoves were used to test emission characteristics when burning 20 raw coal samples commonly used in residential heating activities and 15 semi-coke briquette samples which were made from bituminous coals by industrial carbonization treatment. The carbonization treatment removes volatile compounds from raw coals which are the major precursors for PM formation and carbon emission. The average emission factors of primary PM2.5, elemental carbon, organic carbon, and carbon monoxide for the tested semi-coke briquettes are much lower than those of the tested raw coals. Based on the current coal consumption data in China, switching to semi-coke briquettes can reduce average emission factors of these species by about 92%, 98%, 91%, and 34%, respectively. Additionally, semi-coke briquette has relatively lower price and higher burnout ratio. The replacement of raw coals with semi-coke briquettes is a feasible path to reduce pollution emissions from household activities.

  5. Impact of GHG warming on the mean and extreme loading of particulate matter pollution in a chemistry-climate model ensemble simulation

    NASA Astrophysics Data System (ADS)

    Xu, Y.; Lamarque, J. F.; Wu, X.

    2017-12-01

    Particulate matter with the diameter smaller than 2.5 micrometers (PM2.5) poses health threats to human populations. Regardless of efforts to regulate the pollution sources, it is unclear how climate change caused by greenhouse gases (GHGs) would affect PM2.5 levels. Using century-long ensemble simulations with Community Earth System Model 1 (CESM1), we show that, if the anthropogenic emissions would remain at the level in the year 2005, the global surface concentration and atmospheric column burden of sulfate, black carbon, and primary organic carbon would still increase by 5-10% at the end of 21st century (2090-2100) due to global warming alone. The decrease in the wet removal flux of PM2.5, despite an increase in global precipitation, is the primary cause for the increase in the PM2.5 column burden. Regionally over North America and East Asia, a shift of future precipitation toward more frequent heavy events contributes to weakened wet removal fluxes. Based on the daily model output, the frequency and intensity of extreme pollution events are also studied. We found that both stagnation frequency and rainfall changes serve to worsen extreme pollution in the future.

  6. Semi-coke briquettes: towards reducing emissions of primary PM2.5, particulate carbon, and carbon monoxide from household coal combustion in China

    PubMed Central

    Li, Qing; Li, Xinghua; Jiang, Jingkun; Duan, Lei; Ge, Su; Zhang, Qi; Deng, Jianguo; Wang, Shuxiao; Hao, Jiming

    2016-01-01

    Direct household use of unprocessed raw coals for cooking and heating without any air pollution control device has caused serious indoor and outdoor environment problems by emitting particulate matter (PM) and gaseous pollutants. This study examined household emission reduction by switching from unprocessed bituminous and anthracite coals to processed semi-coke briquettes. Two typical stoves were used to test emission characteristics when burning 20 raw coal samples commonly used in residential heating activities and 15 semi-coke briquette samples which were made from bituminous coals by industrial carbonization treatment. The carbonization treatment removes volatile compounds from raw coals which are the major precursors for PM formation and carbon emission. The average emission factors of primary PM2.5, elemental carbon, organic carbon, and carbon monoxide for the tested semi-coke briquettes are much lower than those of the tested raw coals. Based on the current coal consumption data in China, switching to semi-coke briquettes can reduce average emission factors of these species by about 92%, 98%, 91%, and 34%, respectively. Additionally, semi-coke briquette has relatively lower price and higher burnout ratio. The replacement of raw coals with semi-coke briquettes is a feasible path to reduce pollution emissions from household activities. PMID:26782059

  7. Modeling the Dynamics and Export of Dissolved Organic Matter in the Northeastern U.S. Continental Shelf

    NASA Technical Reports Server (NTRS)

    Druon, J.N.; Mannino, A.; Signorini, Sergio R.; McClain, Charles R.; Friedrichs, M.; Wilkin, J.; Fennel, K.

    2009-01-01

    Continental shelves are believed to play a major role in carbon cycling due to their high productivity. Particulate organic carbon (POC) burial has been included in models as a carbon sink, but we show here that seasonally produced dissolved organic carbon (DOC) on the shelf can be exported to the open ocean by horizontal transport at similar rates (1-2 mol C/sq m/yr) in the southern U.S. Mid-Atlantic Bight (MAB). The dissolved organic matter (DOM) model imbedded in a coupled circulation-biogeochemical model reveals a double dynamics: the progressive release of dissolved organic nitrogen (DON) in the upper layer during summer increases the regenerated primary production by 30 to 300%, which, in turns ; enhances the DOC production mainly from phytoplankton exudation in the upper layer and solubilization of particulate organic matter (POM) deeper in the water column. This analysis suggests that DOM is a key element for better representing the ecosystem functioning and organic fluxes in models because DOM (1) is a major organic pool directly related to primary production, (2) decouples partially the carbon and nitrogen cycles (through carbon excess uptake, POM solubilization and DOM mineralization) and (3) is intimately linked to the residence time of water masses for its distribution and export.

  8. Online single particle measurement of fireworks pollution during Chinese New Year in Nanning.

    PubMed

    Li, Jingyan; Xu, Tingting; Lu, Xiaohui; Chen, Hong; Nizkorodov, Sergey A; Chen, Jianmin; Yang, Xin; Mo, Zhaoyu; Chen, Zhiming; Liu, Huilin; Mao, Jingying; Liang, Guiyun

    2017-03-01

    Time-resolved single-particle measurements were conducted during Chinese New Year in Nanning, China. Firework displays resulted in a burst of SO 2 , coarse mode, and accumulation mode (100-500nm) particles. Through single particle mass spectrometry analysis, five different types of particles (fireworks-metal, ash, dust, organic carbon-sulfate (OC-sulfate), biomass burning) with different size distributions were identified as primary emissions from firework displays. The fireworks-related particles accounted for more than 70% of the total analyzed particles during severe firework detonations. The formation of secondary particulate sulfate and nitrate during firework events was investigated on single particle level. An increase of sulfite peak (80SO 3 - ) followed by an increase of sulfate peaks (97HSO 4 - +96SO 4 - ) in the mass spectra during firework displays indicated the aqueous uptake and oxidation of SO 2 on particles. High concentration of gaseous SO 2 , high relative humidity and high particle loading likely promoted SO 2 oxidation. Secondary nitrate formed through gas-phase oxidation of NO 2 to nitric acid, followed by the condensation into particles as ammonium nitrate. This study shows that under worm, humid conditions, both primary and secondary aerosols contribute to the particulate air pollution during firework displays. Copyright © 2016. Published by Elsevier B.V.

  9. Coccolithovirus facilitation of carbon export in the North Atlantic.

    PubMed

    Laber, Christien P; Hunter, Jonathan E; Carvalho, Filipa; Collins, James R; Hunter, Elias J; Schieler, Brittany M; Boss, Emmanuel; More, Kuldeep; Frada, Miguel; Thamatrakoln, Kimberlee; Brown, Christopher M; Haramaty, Liti; Ossolinski, Justin; Fredricks, Helen; Nissimov, Jozef I; Vandzura, Rebecca; Sheyn, Uri; Lehahn, Yoav; Chant, Robert J; Martins, Ana M; Coolen, Marco J L; Vardi, Assaf; DiTullio, Giacomo R; Van Mooy, Benjamin A S; Bidle, Kay D

    2018-05-01

    Marine phytoplankton account for approximately half of global primary productivity 1 , making their fate an important driver of the marine carbon cycle. Viruses are thought to recycle more than one-quarter of oceanic photosynthetically fixed organic carbon 2 , which can stimulate nutrient regeneration, primary production and upper ocean respiration 2 via lytic infection and the 'virus shunt'. Ultimately, this limits the trophic transfer of carbon and energy to both higher food webs and the deep ocean 2 . Using imagery taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua satellite, along with a suite of diagnostic lipid- and gene-based molecular biomarkers, in situ optical sensors and sediment traps, we show that Coccolithovirus infections of mesoscale (~100 km) Emiliania huxleyi blooms in the North Atlantic are coupled with particle aggregation, high zooplankton grazing and greater downward vertical fluxes of both particulate organic and particulate inorganic carbon from the upper mixed layer. Our analyses captured blooms in different phases of infection (early, late and post) and revealed the highest export flux in 'early-infected blooms' with sinking particles being disproportionately enriched with infected cells and subsequently remineralized at depth in the mesopelagic. Our findings reveal viral infection as a previously unrecognized ecosystem process enhancing biological pump efficiency.

  10. Global Marine Productivity and Living-Phytoplankton Carbon Biomass Estimated from a Physiological Growth Model

    NASA Astrophysics Data System (ADS)

    Arteaga, L.; Pahlow, M.; Oschlies, A.

    2016-02-01

    Primay production by marine phytoplankton essentially drives the oceanic biological carbon pump. Global productivity estimates are commonly founded on chlorophyll-based primary production models. However, a major drawback of most of these models is that variations in chlorophyll concentration do not necessarily account for changes in phytoplankton biomass resulting from the physiological regulation of the chlorophyll-to-carbon ratio (Chl:C). Here we present phytoplankton production rates and surface phytoplankton C concentrations for the global ocean for 2005-2010, obtained by combining satellite Chl observations with a mechanistic model for the acclimation of phytoplankton stoichiometry to variations in nutrients, light and temperature. We compare our inferred phytoplankton C concentrations with an independent estimate of surface particulate organic carbon (POC) to identify for the first time the global contribution of living phytoplankton to total POC in the surface ocean. Our annual primary production (46 Pg C yr-1) is in good agreement with other C-based model estimates obtained from satellite observations. We find that most of the oligotrophic surface ocean is dominated by living phytoplankton biomass (between 30-70% of total particulate carbon). Lower contributions are found in the tropical Pacific (10-30% phytoplankton) and the Southern Ocean (≈ 10%). Our method provides a novel analytical tool for identifying changes in marine plankton communities and carbon cycling.

  11. Beyond the Examination Room

    PubMed Central

    O'Malley, Ann S; Forrest, Christopher B

    2002-01-01

    OBJECTIVE To assess whether primary care performance of low-income women's primary care delivery sites is associated with the strength of their relationships with their physicians. DESIGN Random-digit-dial and targeted household telephone survey of a population-based sample. SETTING Washington, D.C. census tracts with ≥30% of households below 200% of federal poverty threshold. PARTICIPANTS Women over age 40 (N = 1,205), 82% of whom were African American. MEASUREMENTS AND MAIN RESULTS The response rate was 85%. Primary care performance was assessed using women's ratings of their systems' accessibility (organizational, geographic, and financial), continuity, comprehensiveness, and coordination. Respondents' ratings of trust in their physicians, communication with their physicians, and compassion shown by their physicians were used to operationalize the patient-physician relationship. Controlling for population and insurance characteristics, 4 primary care features were positively associated with women's trust in and communication with their physicians: continuity with a single clinician, organizational accessibility of the practice, comprehensive care, and coordination of specialty care services. Better organizational access, but not geographic or financial access, was associated with greater levels of trust, compassion, and communication (odds ratios [ORs], 3.2, 7.4, and 6.9, respectively; P≤ .01). Women who rated highest their doctor's ability to take care of all of their health care needs (highest level of comprehensiveness) had 11 times the odds of trusting their physician (P≤ .01) and 6 times the odds of finding their physicians compassionate and communicative (P≤ .01), compared to those with the lowest level of comprehensiveness. CONCLUSIONS Primary care delivery sites organized to be more accessible, to link patients with the same clinician for their visits, to provide for all of a woman's health care needs, and to coordinate specialty care services are associated with stronger relationships between low-income women and their physicians. Primary care systems that fail to emphasize these features of primary care may jeopardize the clinician-patient relationship and indirectly the quality of care and health outcomes. PMID:11903777

  12. Ellipsoid-conic radiation collector and method

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Brunsting, A.; Hogg, W.R.

    Disclosed is a radiation collector apparatus and method primarily for counting and analyzing a flow of dilute particulate material, such as blood cells, sperm cells and the like, through the use of light detection. The radiation collector apparatus comprises a reflector chamber having an ellipsoidal reflector surface with a pair of elipsoidal foci defining a first focus, f11, and second focus, f12, and a second reflector surface with a primary focus, f21, positioned at the same point as focus f12, and a secondary focus, f22. The second reflector surface has the configuration of one of the conic sections of revolution.more » In operation the radiation collector apparatus is provided with an intensifed beam of light and a stream of particulate material aligned to intersect the intensifed beam of light at focus f11. Detectable light signals, after two reflections, are received in a focused beam by a photosensitive detector.« less

  13. LSA Large Area Silicon Sheet Task Continuous Czochralski Process Development

    NASA Technical Reports Server (NTRS)

    Rea, S. N.

    1979-01-01

    A commercial Czochralski crystal growing furnace was converted to a continuous growth facility by installation of a small, in-situ premelter with attendant silicon storage and transport mechanisms. Using a vertical, cylindrical graphite heater containing a small fused quartz test tube linear from which the molten silicon flowed out the bottom, approximately 83 cm of nominal 5 cm diamter crystal was grown with continuous melt addition furnished by the test tube premelter. High perfection crystal was not obtained, however, due primarily to particulate contamination of the melt. A major contributor to the particulate problem was severe silicon oxide buildup on the premelter which would ultimately drop into the primary melt. Elimination of this oxide buildup will require extensive study and experimentation and the ultimate success of continuous Czochralski depends on a successful solution to this problem. Economically, the continuous Czochralski meets near-term cost goals for silicon sheet material.

  14. El Chichon - Composition of plume gases and particles

    NASA Technical Reports Server (NTRS)

    Kotra, J. P.; Finnegan, D. L.; Zoller, W. H.; Hart, M. A.; Moyers, J. L.

    1983-01-01

    Aircraft measurements were made of trace gases, atmospheric particles, and condensed acid volatiles in the plume of El Chichon volcano, Chiapas, Mexico, in November 1982. Hydrogen sulfide was the primary gaseous sulfur species in the plume at the time of collection. Concentrations of 28 elements were determined by neutron activation analysis of particulate material from the plume. The volatile elements sulfur, chlorine, arsenic, selenium, bromine, antimony, iodine, tungsten, and mercury were enriched relative to bulk pyroclastic material by factors of 60 to 20,000. Arsenic, antimony, and selenium were associated predominantly with small (not greater than 3 micrometer) particles. Calcium and sodium were present almost exclusively on larger particles and aluminum and manganese were bimodally distributed. Ashladen particulate material injected into the stratosphere during the early violent eruptions was enriched by factors of 10 to 30 relative to ash in some of the same elements observed in the quiescent plume.

  15. Recent changes in particulate air pollution over China observed from space and the ground: effectiveness of emission control.

    PubMed

    Lin, Jintai; Nielsen, Chris P; Zhao, Yu; Lei, Yu; Liu, Yang; McElroy, Michael B

    2010-10-15

    The Chinese government has moved aggressively since 2005 to reduce emissions of a number of pollutants including primary particulate matter (PM) and sulfur dioxide (SO(2)), efforts inadvertently aided since late 2008 by economic recession. Satellite observations of aerosol optical depth (AOD) and column nitrogen dioxide (NO(2)) provide independent indicators of emission trends, clearly reflecting the sharp onset of the recession in the fall of 2008 and rebound of the economy in the latter half of 2009. Comparison of AOD with ground-based observations of PM over a longer period indicate that emission-control policies have not been successful in reducing concentrations of aerosol pollutants at smaller size range over industrialized regions of China. The lack of success is attributed to the increasing importance of anthropogenic secondary aerosols formed from precursor species including nitrogen oxides (NO(x)), non-methane volatile organic compounds (NMVOC), and ammonia (NH(3)).

  16. Test and evaluation of the heat recovery incinerator system at Naval Station, Mayport, Florida

    NASA Astrophysics Data System (ADS)

    1981-05-01

    This report describes test and evaluation of the two-ton/hr heat recovery incinerator (HRI) facility located at Mayport Naval Station, Fla., carried out during November and December 1980. The tests included: (1) Solid Waste: characterization, heating value, and ultimate analysis, (2) Ash: moisture, combustibles, and heating values of both bottom and cyclone ashes; Extraction Procedure toxicity tests on leachates from both bottom and cyclone ashes; trace metals in cyclone particulates, (3) Stack Emissions: particulates (quantity and size distribution), chlorides, oxygen, carbon dioxide, carbon monoxide, and trace elements, and (4) Heat and Mass Balance: all measurements required to carry out complete heat and mass balance calculations over the test period. The overall thermal efficiency of the HRI facility while operating at approximately 1.0 ton/hr was found to be 49% when the primary Btu equivalent of the electrical energy consumed during the test program was included.

  17. Blood dendritic cells interact with splenic marginal zone B cells to initiate T-independent immune responses.

    PubMed

    Balázs, Mercedesz; Martin, Flavius; Zhou, Tong; Kearney, John

    2002-09-01

    Marginal zone (MZ) and B1 B lymphocytes participate jointly in the early immune response against T-independent (TI) particulate antigens. Here we show that blood-derived neutrophil granulocytes and CD11c(lo) immature dendritic cells (DC) are the primary cells that efficiently capture and transport particulate bacteria to the spleen. In a systemic infection, CD11c(lo) DC, but not neutrophils, provide critical survival signals, which can be inhibited by TACI-Fc, to antigen-specific MZ B cells and promote their differentiation into IgM-secreting plasmablasts. In a local TI response, peritoneal cavity macrophages provide similar support to B1 B-derived Ag-specific blasts. In the absence of soluble TACI ligands, Ag-activated MZ- and B1-derived blasts lack survival signals and undergo apoptosis, resulting in severely impaired antibody responses.

  18. In Situ Burning of Oil Spills

    PubMed Central

    Evans, David D.; Mulholland, George W.; Baum, Howard R.; Walton, William D.; McGrattan, Kevin B.

    2001-01-01

    For more than a decade NIST conducted research to understand, measure and predict the important features of burning oil on water. Results of that research have been included in nationally recognized guidelines for approval of intentional burning. NIST measurements and predictions have played a major role in establishing in situ burning as a primary oil spill response method. Data are given for pool fire burning rates, smoke yield, smoke particulate size distribution, smoke aging, and polycyclic aromatic hydrocarbon content of the smoke for crude and fuel oil fires with effective diameters up to 17.2 m. New user-friendly software, ALOFT, was developed to quantify the large-scale features and trajectory of wind blown smoke plumes in the atmosphere and estimate the ground level smoke particulate concentrations. Predictions using the model were tested successfully against data from large-scale tests. ALOFT software is being used by oil spill response teams to help assess the potential impact of intentional burning. PMID:27500022

  19. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lam, P.J.; Bishop, J.K.B

    Here we show that labile particulate iron and manganese concentrations in the upper 500m of the Western Subarctic Pacific, an iron-limited High Nutrient Low Chlorophyll (HNLC) region, have prominent subsurface maxima between 100-200 m, reaching 3 nM and 600 pM, respectively. The subsurface concentration maxima in particulate Fe are characterized by a more reduced oxidation state, suggesting a source from primary volcagenic minerals such as from the Kuril/Kamchatka margin. The systematics of these profiles suggest a consistently strong lateral advection of labile Mn and Fe from redox-mobilized labile sources at the continental shelf supplemented by a more variable source ofmore » Fe from the upper continental slope. This subsurface supply of iron from the continental margin is shallow enough to be accessible to the surface through winter upwelling and vertical mixing, and is likely a key source of bioavailable Fe to the HNLC North Pacific.« less

  20. Remote Sensing of Particulate Organic Carbon Pools in the High-Latitude Oceans

    NASA Technical Reports Server (NTRS)

    Stramski, Dariusz; Stramska, Malgorzata

    2005-01-01

    The general goal of this project was to characterize spatial distributions at basin scales and variability on monthly to interannual timescales of particulate organic carbon (POC) in the high-latitude oceans. The primary objectives were: (1) To collect in situ data in the north polar waters of the Atlantic and in the Southern Ocean, necessary for the derivation of POC ocean color algorithms for these regions. (2) To derive regional POC algorithms and refine existing regional chlorophyll (Chl) algorithms, to develop understanding of processes that control bio-optical relationships underlying ocean color algorithms for POC and Chl, and to explain bio-optical differentiation between the examined polar regions and within the regions. (3) To determine basin-scale spatial patterns and temporal variability on monthly to interannual scales in satellite-derived estimates of POC and Chl pools in the investigated regions for the period of time covered by SeaWiFS and MODIS missions.

  1. Particulate matter pollution in the coal-producing regions of the Appalachian Mountains: Integrated ground-based measurements and satellite analysis.

    PubMed

    Aneja, Viney P; Pillai, Priya R; Isherwood, Aaron; Morgan, Peter; Aneja, Saurabh P

    2017-04-01

    This study integrates the relationship between measured surface concentrations of particulate matter 10 μm or less in diameter (PM 10 ), satellite-derived aerosol optical depth (AOD), and meteorology in Roda, Virginia, during 2008. A multiple regression model was developed to predict the concentrations of particles 2.5 μm or less in diameter (PM 2.5 ) at an additional location in the Appalachia region, Bristol, TN. The model was developed by combining AOD retrievals from Moderate Resolution Imaging Spectro-radiometer (MODIS) sensor on board the EOS Terra and Aqua Satellites with the surface meteorological observations. The multiple regression model predicted PM 2.5 (r 2 = 0.62), and the two-variable (AOD-PM 2.5 ) model predicted PM 2.5 (r 2 = 0.4). The developed model was validated using particulate matter recordings and meteorology observations from another location in the Appalachia region, Hazard, Kentucky. The model was extrapolated to the Roda, VA, sampling site to predict PM 2.5 mass concentrations. We used 10 km x 10 km resolution MODIS 550 nm AOD to predict ground level PM 2.5 . For the relevant period in 2008, in Roda, VA, the predicted PM 2.5 mass concentration is 9.11 ± 5.16 μg m -3 (mean ± 1SD). This is the first study that couples ground-based Particulate Matter measurements with satellite retrievals to predict surface air pollution at Roda, Virginia. Roda is representative of the Appalachian communities that are commonly located in narrow valleys, or "hollows," where homes are placed directly along the roads in a region of active mountaintop mining operations. Our study suggests that proximity to heavy coal truck traffic subjects these communities to chronic exposure to coal dust and leads us to conclude that there is an urgent need for new regulations to address the primary sources of this particulate matter.

  2. Source apportionment of airborne particulates through receptor modeling: Indian scenario

    NASA Astrophysics Data System (ADS)

    Banerjee, Tirthankar; Murari, Vishnu; Kumar, Manish; Raju, M. P.

    2015-10-01

    Airborne particulate chemistry mostly governed by associated sources and apportionment of specific sources is extremely essential to delineate explicit control strategies. The present submission initially deals with the publications (1980s-2010s) of Indian origin which report regional heterogeneities of particulate concentrations with reference to associated species. Such meta-analyses clearly indicate the presence of reservoir of both primary and secondary aerosols in different geographical regions. Further, identification of specific signatory molecules for individual source category was also evaluated in terms of their scientific merit and repeatability. Source signatures mostly resemble international profile while, in selected cases lack appropriateness. In India, source apportionment (SA) of airborne particulates was initiated way back in 1985 through factor analysis, however, principal component analysis (PCA) shares a major proportion of applications (34%) followed by enrichment factor (EF, 27%), chemical mass balance (CMB, 15%) and positive matrix factorization (PMF, 9%). Mainstream SA analyses identify earth crust and road dust resuspensions (traced by Al, Ca, Fe, Na and Mg) as a principal source (6-73%) followed by vehicular emissions (traced by Fe, Cu, Pb, Cr, Ni, Mn, Ba and Zn; 5-65%), industrial emissions (traced by Co, Cr, Zn, V, Ni, Mn, Cd; 0-60%), fuel combustion (traced by K, NH4+, SO4-, As, Te, S, Mn; 4-42%), marine aerosols (traced by Na, Mg, K; 0-15%) and biomass/refuse burning (traced by Cd, V, K, Cr, As, TC, Na, K, NH4+, NO3-, OC; 1-42%). In most of the cases, temporal variations of individual source contribution for a specific geographic region exhibit radical heterogeneity possibly due to unscientific orientation of individual tracers for specific source and well exaggerated by methodological weakness, inappropriate sample size, implications of secondary aerosols and inadequate emission inventories. Conclusively, a number of challenging issues and specific recommendations have been included which need to be considered for a scientific apportionment of particulate sources in different geographical regions of India.

  3. On the importance of listening comprehension

    PubMed Central

    Hogan, Tiffany P.; Adlof, Suzanne M.; Alonzo, Crystle

    2015-01-01

    The simple view of reading highlights the importance of two primary components which account for individual differences in reading comprehension across development: word recognition (i.e., decoding) and listening comprehension. While assessments and interventions for decoding have been the focus of pedagogy in the past several decades, the importance of listening comprehension has received less attention. This paper reviews evidence showing that listening comprehension becomes the dominating influence on reading comprehension starting even in the elementary grades. It also highlights a growing number of children who fail to develop adequate reading comprehension skills, primarily due to deficient listening comprehension skills: poor comprehenders. Finally it discusses key language influences on listening comprehension for consideration during assessment and treatment of reading disabilities. PMID:24833426

  4. On the importance of listening comprehension.

    PubMed

    Hogan, Tiffany P; Adlof, Suzanne M; Alonzo, Crystle N

    2014-06-01

    The simple view of reading highlights the importance of two primary components which account for individual differences in reading comprehension across development: word recognition (i.e., decoding) and listening comprehension. While assessments and interventions for decoding have been the focus of pedagogy in the past several decades, the importance of listening comprehension has received less attention. This paper reviews evidence showing that listening comprehension becomes the dominating influence on reading comprehension starting even in the elementary grades. It also highlights a growing number of children who fail to develop adequate reading comprehension skills, primarily due to deficient listening comprehension skills (i.e., poor comprehenders). Finally we discuss key language influences on listening comprehension for consideration during assessment and treatment of reading disabilities.

  5. Physician specialty and the quality of medical care experiences in the context of the Taiwan national health insurance system.

    PubMed

    Tsai, Jenna; Shi, Leiyu; Yu, Wei-Lung; Hung, Li-Mei; Lebrun, Lydie A

    2010-01-01

    Based on a recent patient survey from Taiwan, where there is universal health insurance coverage and unrestricted physician choice, this study examined the relationship between physician specialty and the quality of primary medical care experiences. We assessed ambulatory patients' experiences with medical care using the Primary Care Assessment Tool, representing 7 primary care domains: first contact (ie, accessibility and utilization); longitudinality (ie, ongoing care); coordination (ie, referrals and information systems); comprehensiveness (ie, services available and provided); family centeredness; community orientation; and cultural competence. Having a primary care physician was significantly associated with patients reporting higher quality of primary care experiences. Specifically, relative to specialty care physicians, primary care physicians enhanced accessibility, achieved better community orientation and cultural competence, and provided more comprehensive services. In an area with universal health insurance and unrestricted physician choice, ambulatory patients of primary care physicians rated their medical care experiences as superior to those of patients of specialists. In addition to providing health insurance coverage, promoting primary care should be included as a health policy to improve patients' quality of ambulatory medical care experiences.

  6. Health impacts of frequent heavy automobile traffic on children and adolescents.

    PubMed

    Akpan, Akpan I

    2004-01-01

    This paper assesses the extent to which particulate, elemental and organic carbon emissions from heavy traffic in urban city roads affect the health of children and the adolescent health. Although the health effects of exposures may be cumulative, it is in the adolescence that the manifestations are realized. This paper therefore, assesses the best way forward for monitoring and preventing the environmental health impacts of heavy traffic on children and adolescents who live within the vicinity of urban city transportation systems. Major urban cities such as Houston, New York, and California are cited as examples of cities where health-related problems have already been reported. The particulate, elemental and organic carbon emissions are reviewed as the sources by which heavy traffic and the hazardous chemical emissions affect the health of the populace. The role of accessory loading and engine speed on idling emissions in direct health risks of children and adolescents is evaluated. The association of particulate, elemental, and organic carbon emission with respiratory effects (including, allergies and asthma), and the related behavior problems in children and the adolescents are discussed. The best strategies in preventing the effects of heavy traffic in the urban cities are suggested by introducing new effective monitoring techniques and exposure assessment methods. It is visualized that a more comprehensive research is needed to develop robust regulatory systems that would control the efficiency of automobiles and prevent the adverse health effects relating to heavy traffics in urban city roads. Strong city environmental health authorities-community partnerships relevant to exposure information should be encouraged.

  7. Impacts of freeway traffic conditions on in-vehicle exposure to ultrafine particulate matter

    NASA Astrophysics Data System (ADS)

    Bigazzi, Alexander Y.; Figliozzi, Miguel A.

    2012-12-01

    There is evidence of adverse health impacts from human exposure to traffic-related ultrafine particulate matter pollution. As more commuters are spending a significant portion of their daily routine inside vehicles, it is increasingly relevant to study exposure levels to harmful pollutants inside the vehicle microenvironment. This study is one of the first research efforts to combine detailed freeway traffic data (at 20 s intervals) and in-vehicle ultrafine particulate (UFP) exposure data under varying vehicle ventilation conditions. Results show that due to negative correlation between traffic speed and density, traffic states have a small but significant impact on in-vehicle UFP concentrations, highest in high traffic flow-high speed conditions or in high traffic density-low speed conditions. Vehicle cabin barrier effects are the primary determinant of in-vehicle exposure concentrations, providing 15% protection with the windows down, 47% protection with the windows up and the vent open, and 83-90% protection with the windows up and the vent closed (more with the air conditioning on). Unique results from this study include the dominance of ventilation over traffic effects on UFP and the non-linear relationships between traffic variables and UFP concentrations. The results of this research have important implications for exposure modeling and potential exposure mitigation strategies.

  8. Occurrence and Characterization of Steroid Growth Promoters Associated with Particulate Matter Originating from Beef Cattle Feedyards.

    PubMed

    Blackwell, Brett R; Wooten, Kimberly J; Buser, Michael D; Johnson, Bradley J; Cobb, George P; Smith, Philip N

    2015-07-21

    Studies of steroid growth promoters from beef cattle feedyards have previously focused on effluent or surface runoff as the primary route of transport from animal feeding operations. There is potential for steroid transport via fugitive airborne particulate matter (PM) from cattle feedyards; therefore, the objective of this study was to characterize the occurrence and concentration of steroid growth promoters in PM from feedyards. Air sampling was conducted at commercial feedyards (n = 5) across the Southern Great Plains from 2010 to 2012. Total suspended particulates (TSP), PM10, and PM2.5 were collected for particle size analysis and steroid growth promoter analysis. Particle size distributions were generated from TSP samples only, while steroid analysis was conducted on extracts of PM samples using liquid chromatography mass spectrometry. Of seven targeted steroids, 17α-estradiol and estrone were the most commonly detected, identified in over 94% of samples at median concentrations of 20.6 and 10.8 ng/g, respectively. Melengestrol acetate and 17α-trenbolone were detected in 31% and 39% of all PM samples at median concentrations of 1.3 and 1.9 ng/g, respectively. Results demonstrate PM is a viable route of steroid transportation and may be a significant contributor to environmental steroid hormone loading from cattle feedyards.

  9. Grammatical comprehension deficits in non-fluent/agrammatic primary progressive aphasia.

    PubMed

    Charles, Dorothy; Olm, Christopher; Powers, John; Ash, Sharon; Irwin, David J; McMillan, Corey T; Rascovsky, Katya; Grossman, Murray

    2014-03-01

    Grammatical comprehension difficulty is an essential supporting feature of the non-fluent/agrammatic variant of primary progressive aphasia (naPPA), but well-controlled clinical measures of grammatical comprehension are unavailable. To develop a measure of grammatical comprehension and examine this comparatively in PPA variants and behavioural-variant frontotemporal degeneration (bvFTD) and to assess the neuroanatomic basis for these deficits with volumetric grey matter atrophy and whole-brain fractional anisotropy (FA) in white matter tracts. Case-control study. Academic medical centre. 39 patients with variants of PPA (naPPA=12, lvPPA=15 and svPPA=12), 27 bvFTD patients without aphasia and 12 healthy controls. Grammatical comprehension accuracy. Patients with naPPA had selective difficulty understanding cleft sentence structures, while all PPA variants and patients with bvFTD were impaired with sentences containing a centre-embedded subordinate clause. Patients with bvFTD were also impaired understanding sentences involving short-term memory. Linear regressions related grammatical comprehension difficulty in naPPA to left anterior-superior temporal atrophy and reduced FA in corpus callosum and inferior frontal-occipital fasciculus. Difficulty with centre-embedded sentences in other PPA variants was related to other brain regions. These findings emphasise a distinct grammatical comprehension deficit in naPPA and associate this with interruption of a frontal-temporal neural network.

  10. Spatial patterns of mobile source particulate matter emissions-to-exposure relationships across the United States

    NASA Astrophysics Data System (ADS)

    Greco, Susan L.; Wilson, Andrew M.; Spengler, John D.; Levy, Jonathan I.

    Assessing the public health benefits from air pollution control measures is assisted by understanding the relationship between mobile source emissions and subsequent fine particulate matter (PM 2.5) exposure. Since this relationship varies by location, we characterized its magnitude and geographic distribution using the intake fraction (iF) concept. We considered emissions of primary PM 2.5 as well as particle precursors SO 2 and NO x from each of 3080 counties in the US. We modeled the relationship between these emissions and total US population exposure to PM 2.5, making use of a source-receptor matrix developed for health risk assessment. For primary PM 2.5, we found a median iF of 1.2 per million, with a range of 0.12-25. Half of the total exposure was reached by a median distance of 150 km from the county where mobile source emissions originated, though this spatial extent varied across counties from within the county borders to 1800 km away. For secondary ammonium sulfate from SO 2 emissions, the median iF was 0.41 per million (range: 0.050-10), versus 0.068 per million for secondary ammonium nitrate from NO x emissions (range: 0.00092-1.3). The median distance to half of the total exposure was greater for secondary PM 2.5 (450 km for sulfate, 390 km for nitrate). Regression analyses using exhaustive population predictors explained much of the variation in primary PM 2.5 iF ( R2=0.83) as well as secondary sulfate and nitrate iF ( R2=0.74 and 0.60), with greater near-source contribution for primary than for secondary PM 2.5. We conclude that long-range dispersion models with coarse geographic resolution are appropriate for risk assessments of secondary PM 2.5 or primary PM 2.5 emitted from mobile sources in rural areas, but that more resolved dispersion models are warranted for primary PM 2.5 in urban areas due to the substantial contribution of near-source populations.

  11. Physicochemical and biological factors controlling water column metabolism in Sundarbans estuary, India

    PubMed Central

    2012-01-01

    Background Sundarbans is the single largest deltaic mangrove forest in the world, formed at estuarine phase of the Ganges - Brahmaputra river system. Primary productivity of marine and coastal phytoplankton contributes to 15% of global oceanic production. But unfortunately estuarine dynamics of tropical and subtropical estuaries have not yet received proper attention in spite of the fact that they experience considerable anthropogenic interventions and a baseline data is required for any future comparison. This study is an endeavor to this end to estimate the primary productivity (gross and net), community respiration and nitrification rates in different rivers and tidal creeks around Jharkhali island, a part of Sundarbans estuary surrounded by the mangrove forest during a period of three years starting from November’08 to October’11. Results Various physical and chemical parameters of water column like pH, temperature, conductivity, dissolved oxygen, turbidity, suspended particulate matter, secchi disc index, tidal fluctuation and tidal current velocity, standing crop and nutrients were measured along with water column productivity. Relationship of net water column productivity with algal biomass (standing crop), nutrient loading and turbidity were determined experimentally. Correlations of bacterial abundance with community respiration and nitrification rates were also explored. Annual integrated phytoplankton production rate of this tidal estuary was estimated to be 151.07 gC m-2 y-1. Gross primary productivity showed marked inter annual variation being lowest in monsoon and highest in postmonsoon period. Conclusion Average primary production was a function of nutrient loading and light penetration in the water column. High aquatic turbidity, conductivity and suspended particulate matter were the limiting factors to attenuate light penetration with negative influence on primary production. Community respiration and nitrification rates of the estuary were influenced by the bacterial abundance. The estuary was phosphorus limited in postmonsoon whereas nitrogen-limited in premonsoon and monsoon period. High algal biomass and primary productivity indicated the estuary to be in eutrophic state in most of the time throughout the year. Our study also indicated a seasonal shifting between autotrophic and heterotrophic conditions in Sundarban estuarine ecosystem and it is a tropical, well mixed (high tidal influx) and marine dominated (no fresh water connection) system. PMID:23083531

  12. Physicochemical and biological factors controlling water column metabolism in Sundarbans estuary, India.

    PubMed

    Chaudhuri, Kaberi; Manna, Suman; Sarma, Kakoli Sen; Naskar, Pankaj; Bhattacharyya, Somenath; Bhattacharyya, Maitree

    2012-10-19

    Sundarbans is the single largest deltaic mangrove forest in the world, formed at estuarine phase of the Ganges - Brahmaputra river system. Primary productivity of marine and coastal phytoplankton contributes to 15% of global oceanic production. But unfortunately estuarine dynamics of tropical and subtropical estuaries have not yet received proper attention in spite of the fact that they experience considerable anthropogenic interventions and a baseline data is required for any future comparison. This study is an endeavor to this end to estimate the primary productivity (gross and net), community respiration and nitrification rates in different rivers and tidal creeks around Jharkhali island, a part of Sundarbans estuary surrounded by the mangrove forest during a period of three years starting from November'08 to October'11. Various physical and chemical parameters of water column like pH, temperature, conductivity, dissolved oxygen, turbidity, suspended particulate matter, secchi disc index, tidal fluctuation and tidal current velocity, standing crop and nutrients were measured along with water column productivity. Relationship of net water column productivity with algal biomass (standing crop), nutrient loading and turbidity were determined experimentally. Correlations of bacterial abundance with community respiration and nitrification rates were also explored. Annual integrated phytoplankton production rate of this tidal estuary was estimated to be 151.07 gC m-2 y-1. Gross primary productivity showed marked inter annual variation being lowest in monsoon and highest in postmonsoon period. Average primary production was a function of nutrient loading and light penetration in the water column. High aquatic turbidity, conductivity and suspended particulate matter were the limiting factors to attenuate light penetration with negative influence on primary production. Community respiration and nitrification rates of the estuary were influenced by the bacterial abundance. The estuary was phosphorus limited in postmonsoon whereas nitrogen-limited in premonsoon and monsoon period. High algal biomass and primary productivity indicated the estuary to be in eutrophic state in most of the time throughout the year. Our study also indicated a seasonal shifting between autotrophic and heterotrophic conditions in Sundarban estuarine ecosystem and it is a tropical, well mixed (high tidal influx) and marine dominated (no fresh water connection) system.

  13. The Impact of Gender, Socioeconomic Status and Home Language on Primary School Children’s Reading Comprehension in KwaZulu-Natal

    PubMed Central

    Völkel, Gabriela; Seabi, Joseph; Cockcroft, Kate; Goldschagg, Paul

    2016-01-01

    The current study constituted part of a larger, longitudinal, South African-based study, namely, The Road and Aircraft Noise Exposure on Children’s Cognition and Health (RANCH—South Africa). In the context of a multicultural South Africa and varying demographic variables thereof, this study sought to investigate and describe the effects of gender, socioeconomic status and home language on primary school children’s reading comprehension in KwaZulu-Natal. In total, 834 learners across 5 public schools in the KwaZulu-Natal province participated in the study. A biographical questionnaire was used to obtain biographical data relevant to this study, and the Suffolk Reading Scale 2 (SRS2) was used to obtain reading comprehension scores. The findings revealed that there was no statistical difference between males and females on reading comprehension scores. In terms of socioeconomic status (SES), learners from a low socioeconomic background performed significantly better than those from a high socioeconomic background. English as a First Language (EL1) speakers had a higher mean reading comprehension score than speakers who spoke English as an Additional Language (EAL). Reading comprehension is indeed affected by a variety of variables, most notably that of language proficiency. The tool to measure reading comprehension needs to be standardized and administered in more than one language, which will ensure increased reliability and validity of reading comprehension scores. PMID:26999169

  14. The Impact of Gender, Socioeconomic Status and Home Language on Primary School Children's Reading Comprehension in KwaZulu-Natal.

    PubMed

    Völkel, Gabriela; Seabi, Joseph; Cockcroft, Kate; Goldschagg, Paul

    2016-03-15

    The current study constituted part of a larger, longitudinal, South African-based study, namely, The Road and Aircraft Noise Exposure on Children's Cognition and Health (RANCH-South Africa). In the context of a multicultural South Africa and varying demographic variables thereof, this study sought to investigate and describe the effects of gender, socioeconomic status and home language on primary school children's reading comprehension in KwaZulu-Natal. In total, 834 learners across 5 public schools in the KwaZulu-Natal province participated in the study. A biographical questionnaire was used to obtain biographical data relevant to this study, and the Suffolk Reading Scale 2 (SRS2) was used to obtain reading comprehension scores. The findings revealed that there was no statistical difference between males and females on reading comprehension scores. In terms of socioeconomic status (SES), learners from a low socioeconomic background performed significantly better than those from a high socioeconomic background. English as a First Language (EL1) speakers had a higher mean reading comprehension score than speakers who spoke English as an Additional Language (EAL). Reading comprehension is indeed affected by a variety of variables, most notably that of language proficiency. The tool to measure reading comprehension needs to be standardized and administered in more than one language, which will ensure increased reliability and validity of reading comprehension scores.

  15. Hydrocarbon-enhanced particulate filter regeneration via microwave ignition

    DOEpatents

    Gonze, Eugene V.; Brown, David B.

    2010-02-02

    A regeneration method for a particulate filter includes estimating a quantity of particulate matter trapped within the particulate filter, comparing the quantity of particulate matter to a predetermined quantity, heating at least a portion of the particulate filter to a combustion temperature of the particulate matter, and introducing hydrocarbon fuel to the particulate filter. The hydrocarbon fuel facilitates combustion of the particulate matter to regenerate the particulate filter.

  16. Establishment of a Comprehensive Data System for Occupational Training in Kentucky--Phase I, Final Report.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Center for Vocational and Technical Education.

    This document reports on the first of a 3-phase plan to adapt and install a state vocational-technical education comprehensive data system for occupational training in Kentucky. The objective of the system described is to provide more comprehensive analysis of data essential to education decision-makers. Primary users of the system are expected to…

  17. Developmental, Component-Based Model of Reading Fluency: An Investigation of Predictors of Word-Reading Fluency, Text-Reading Fluency, and Reading Comprehension

    ERIC Educational Resources Information Center

    Kim, Young-Suk Grace

    2015-01-01

    The primary goal was to expand our understanding of text-reading fluency (efficiency or automaticity): how its relation to other constructs (e.g., word reading fluency, reading comprehension) changes over time and how it is different from word-reading fluency and reading comprehension. The study examined (a) developmentally changing relations…

  18. Developmental, Component-Based Model of Reading Fluency: An Investigation of Predictors of Word-Reading Fluency, Text-Reading Fluency, and Reading Comprehension

    ERIC Educational Resources Information Center

    Kim, Young-Suk Grace

    2015-01-01

    The primary goal was to expand our understanding of text-reading fluency (efficiency or automaticity): how its relation to other constructs (e.g., word-reading fluency, reading comprehension) changes over time and how it is different from word-reading fluency and reading comprehension. The study examined (a) developmentally changing relations…

  19. Why Does Working Memory Capacity Predict Variation in Reading Comprehension? On the Influence of Mind Wandering and Executive Attention

    ERIC Educational Resources Information Center

    McVay, Jennifer C.; Kane, Michael J.

    2012-01-01

    Some people are better readers than others, and this variation in comprehension ability is predicted by measures of working memory capacity (WMC). The primary goal of this study was to investigate the mediating role of mind-wandering experiences in the association between WMC and normal individual differences in reading comprehension, as predicted…

  20. Predicting Reading Comprehension Academic Achievement in Late Adolescents with Velo-Cardio-Facial (22q11.2 Deletion) Syndrome (VCFS): A Longitudinal Study

    ERIC Educational Resources Information Center

    Antshel, K.; Hier, B.; Fremont, W.; Faraone, S. V.; Kates, W.

    2014-01-01

    Background: The primary objective of the current study was to examine the childhood predictors of adolescent reading comprehension in velo-cardio-facial syndrome (VCFS). Although much research has focused on mathematics skills among individuals with VCFS, no studies have examined predictors of reading comprehension. Methods: 69 late adolescents…

  1. Improving text comprehension strategies in upper primary school children: a design experiment.

    PubMed

    De Corte, E; Verschaffel, L; Van De Ven, A

    2001-12-01

    With respect to the acquisition of competence in reading, new standards for primary education stress more than before the importance of learning and teaching cognitive and metacognitive strategies that facilitate text comprehension. Therefore, there is a need to design a research-based instructional approach to strategic reading comprehension. The design experiment aimed at developing, implementing and evaluating a research-based, but also practically applicable learning environment for enhancing skilled strategy use in upper primary school children when reading a text. Four text comprehension strategies (activating prior knowledge, clarifying difficult words, making a schematic representation of the text, and formulating the main idea) and a metacognitive strategy (regulating one's own reading process) were trained through a variety of highly interactive instructional techniques, namely modelling, whole class discussion, and small group work in the format of reciprocal teaching. Participants in the study were four experimental 5th grade classes (79 children) and eight comparable control classes (149 pupils). The effects of the learning environment were measured using a pretest-post-test-retention design. Multilevel hierarchical linear regression models were used to analyse the quantitative data of a Reading Strategy Test, a standardised Reading Comprehension Test, a Reading Attitude Scale, a Transfer Test and an interview about strategy use during reading. The data of the Reading Strategy Test, the Transfer Test and the interviews about strategy use showed that the experimental group out-performed the control group in terms of the strategy adoption and application during text reading. Whilst the experimental group also scored higher on the Reading Comprehension Test than the control group, the difference was not significant. This design experiment shows that it is possible to foster pupils' use and transfer of strategic reading comprehension skills in regular classrooms by immersing them in a powerful learning environment. But this intervention does not automatically result in improvement of performance on a standardised reading comprehension test.

  2. Evaluation of attention training and metacognitive facilitation to improve reading comprehension in aphasia.

    PubMed

    Lee, Jaime B; Moore Sohlberg, McKay

    2013-05-01

    This pilot study investigated the impact of direct attention training combined with metacognitive facilitation on reading comprehension in individuals with aphasia. A single-subject, multiple baseline design was employed across 4 participants to evaluate potential changes in reading comprehension resulting from an 8-week intervention using Attention Process Training-3 (APT-3). The primary outcome measure was a maze reading task. Pre- and posttesting included attention and reading comprehension measures. Visual inspection of graphed performance data across conditions was used as the primary method of analysis. Treatment effect sizes were calculated for changes in reading comprehension probes from baseline to maintenance phases. Two of the study's 4 participants demonstrated improvements in maze reading, with corresponding effect sizes that were small in magnitude according to benchmarks for aphasia treatment research. All 4 participants made improvements on select standardized measures of attention. Interventions that include a metacognitive component with direct attention training may elicit improvements in participants' attention and allocation of resources. Maze passage reading is a repeated measure that appears sensitive to treatment-related changes in reading comprehension. Issues for future research related to measurement, candidacy, and clinical delivery are discussed.

  3. Applications of synergistic combination of remote sensing and in-situ measurements on urban monitoring of air quality

    NASA Astrophysics Data System (ADS)

    Diaz, Adrian; Dominguez, Victor; Campmier, Mark; Wu, Yonghua; Arend, Mark; Vladutescu, Daniela Viviana; Gross, Barry; Moshary, Fred

    2017-08-01

    In this study, multiple remote sensing and in-situ measurements are combined in order to obtain a comprehensive understanding of the aerosol distribution in New York City. Measurement of the horizontal distribution of aerosols is performed using a scanning eye-safe elastic-backscatter micro-pulse lidar. Vertical distribution of aerosols is measured with a co-located ceilometer. Furthermore, our analysis also includes in-situ measurements of particulate matter and wind speed and direction. These observations combined show boundary layer dynamics as well as transport and inhomogeneous spatial distribution of aerosols, which are of importance for air quality monitoring.

  4. [A method for the implementation and promotion of access to comprehensive and complementary primary healthcare practices].

    PubMed

    Santos, Melissa Costa; Tesser, Charles Dalcanale

    2012-11-01

    The rendering of integrated and complementary practices in the Brazilian Unified Health System is fostered to increase the comprehensiveness of care and access to same, though it is a challenge to incorporate them into the services. Our objective is to provide a simple method of implementation of such practices in Primary Healthcare, derived from analysis of experiences in municipalities, using partial results of a master's thesis that employed research-action methodology. The method involves four stages: 1 - defininition of a nucleus responsible for implementation and consolidation thereof; 2 - situational analysis, with definition of the existing competent professionals; 3 - regulation, organization of access and legitimation; and 4 - implementation cycle: local plans, mentoring and ongoing education in health. The phases are described, justified and briefly discussed. The method encourages the development of rational and sustainable actions, sponsors participatory management, the creation of comprehensivenessand the broadening of care provided in Primary Healthcare by offering progressive and sustainable comprehensive and complementary practices.

  5. Particulate Concentration Levels in Chinatown, Oakland, California

    NASA Astrophysics Data System (ADS)

    Chen, B.; Yeung, A.; Yu, J. F.

    2007-12-01

    Chinatown is located near the center of the busy business district of downtown Oakland, California. It is one of the most inhabited and congested areas in the City of Oakland, averaging 4,000 vehicles and 3,000 pedestrians per hour at a key intersection in the center of the neighborhood. Particles produced by automobiles and construction can settle into the bronchi of lungs and induce asthma attacks, irritate cardiovascular tissue, and possibly lead to lung cancer and death. Particulate pollution is a serious problem that is estimated to cause between 20,000 and 50,000 deaths per year in the US alone. Hence, evaluation of the air quality of the Chinatown neighborhood is important, because it helps to address issues that are of great concern to residents of the area. The primary goal of our project was to measure particulate concentration levels at various intersections in Oakland's Chinatown to determine if the air quality met U.S. EPA standards, and to take note of any trends that may occur over a period of months. We were primarily concerned with particles that are 2.5 micrometers diameter and smaller, as smaller particles are easily inhaled and directly affect the respiratory system. We were interested in identifying any intersections that may have had significantly higher levels than other intersections. Using a map of Chinatown, we chose 12 intersections and made measurements at these points over the course of six months, beginning in February and ending in July of 2007. Particulate matter measurements were made using a FLUKE 893 Particle Counter. Measurements recorded on the first day of our study, February 4, 2007, which was the day of an annual street festival, yielded the highest values for particulate matter concentration in our dataset. This was followed by a significant drop in concentration the following week, and then a gradual increase of concentration as the months progressed. No one location yielded values significantly higher than any other, and, except for the first and last day (where there was experimental error), recorded values seem to meet EPA standards. We conclude that the high particulate matter levels we observed were due to heavy crowding and traffic jams near street corners during the time of the festival. We also conclude that particulate pollution levels in the Chinatown neighborhood are generally acceptable, except during festivities that generate heavy congestion. We intend conduct further investigations, particularly at next year's street festival, to confirm observations made thus far.

  6. Measuring the Attainment of Primary Care.

    ERIC Educational Resources Information Center

    Starfield, Barbara

    1979-01-01

    The definition of primary care is developed and a way is suggested to measure whether it is being achieved. Evaluative questions are identified that can determine whether a system of care is oriented toward primary care. They include assessing first-contact care, coordination of care, comprehensiveness, and longitudinality. (LBH)

  7. Process for reducing organic compounds with calcium, amine, and alcohol

    DOEpatents

    Benkeser, R.A.; Laugal, J.A.; Rappa, A.

    1985-08-06

    Olefins are produced by contacting an organic compound having at least one benzene ring with calcium metal, ethylenediamine, a low molecular weight aliphatic alcohol, and optionally a low molecular weight aliphatic primary amine, and/or an inert, abrasive particulate substance. The reduction is conducted at temperatures ranging from about [minus]10 C to about 30 C or somewhat higher. Substantially all of the organic compounds are converted to corresponding cyclic olefins, primarily diolefins.

  8. Perception of 'comprehensiveness of care': a qualitative study amongst dentists in the Brazilian Health System.

    PubMed

    Mattos, Grazielle Christine Maciel; Gallagher, Jennifer Elizabeth; Paiva, Saul Martins; Abreu, Mauro Henrique Nogueira Guimarães

    2015-01-01

    Comprehensiveness relates both to the scope of services offered and to a holistic clinical approach. The aim of this study was to identify the perception of Brazilian dentists regarding key concepts of comprehensiveness and its importance in primary health care oral health services performed in the public sector. Focus groups were conducted to explore three main concepts, 'patient welcoming', 'bonding' and 'quality of care', as well as their aspects. In total, there were four focus groups comprising seven general dentists, all of whom had at least two years of experience in primary care, from municipalities of varying sizes. Discussions of approximately 60 minutes were conducted, audio-recorded and transcribed. The data were analysed by qualitative thematic analysis, in line with the framework approach. The general dentists reported that they are aware that in the Brazilian Health System, the onset of patient care by primary health care services must happen through 'patient welcoming.' Nevertheless, they suggested that this action is often performed poorly due to the large volume of patients. Although they knew the importance of 'bonding', they realised that there is a lack of education preparing professionals to address interpersonal and social issues. They were aware that 'quality of care' is related to multiple factors. Comprehensiveness, as an approach in dental public health practices, needs to be enhanced, and there is evidence that primary care dentists are aware of the need for such an approach.

  9. Adult Primary Liver Cancer Treatment (PDQ®)—Health Professional Version

    Cancer.gov

    Adult primary liver cancer treatment options include surveillance, surgery, liver transplant, ablation, embolization, targeted therapy, and radiation. Get comprehensive information about liver cancer and treatment options in this clinician summary

  10. Modelling and characterization of primary settlers in view of whole plant and resource recovery modelling.

    PubMed

    Bachis, Giulia; Maruéjouls, Thibaud; Tik, Sovanna; Amerlinck, Youri; Melcer, Henryk; Nopens, Ingmar; Lessard, Paul; Vanrolleghem, Peter A

    2015-01-01

    Characterization and modelling of primary settlers have been neglected pretty much to date. However, whole plant and resource recovery modelling requires primary settler model development, as current models lack detail in describing the dynamics and the diversity of the removal process for different particulate fractions. This paper focuses on the improved modelling and experimental characterization of primary settlers. First, a new modelling concept based on particle settling velocity distribution is proposed which is then applied for the development of an improved primary settler model as well as for its characterization under addition of chemicals (chemically enhanced primary treatment, CEPT). This model is compared to two existing simple primary settler models (Otterpohl and Freund; Lessard and Beck), showing to be better than the first one and statistically comparable to the second one, but with easier calibration thanks to the ease with which wastewater characteristics can be translated into model parameters. Second, the changes in the activated sludge model (ASM)-based chemical oxygen demand fractionation between inlet and outlet induced by primary settling is investigated, showing that typical wastewater fractions are modified by primary treatment. As they clearly impact the downstream processes, both model improvements demonstrate the need for more detailed primary settler models in view of whole plant modelling.

  11. Criteria pollutant and acid aerosol characterization study, Catano, Puerto Rico

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Edgerton, E.S.; Harlos, D.P.; Sune, J.M.

    1995-07-01

    The primary objective of the Catano Criteria Pollutant and Acid Aerosol Characterization Study (CPAACS) was to measure criteria pollutant concentrations and acid aerosol concentrations in and around the Ward of Catano, Puerto Rico, during the summer of 1994. Continuous air sampling for criteria pollutants was performed at three fixed stations and one moobile station that was deployed to four locations. Air samples for acid aerosol analyses and particulate matter measurements were collected at three sites. Semicontinuous sulfate analysis was performed at the primary site. Continuous measurements of wind speed, wind direction, temperature, and relative humidity were also made at eachmore » site. The study was conducted from June 1 through September 30, 1994.« less

  12. Putting Text Complexity in Context: Refocusing on Comprehension of Complex Text

    ERIC Educational Resources Information Center

    Valencia, Sheila W.; Wixson, Karen K.; Pearson, P. David

    2014-01-01

    The Common Core State Standards for English Language Arts have prompted enormous attention to issues of text complexity. The purpose of this article is to put text complexity in perspective by moving from a primary focus on the text itself to a focus on the comprehension of complex text. We argue that a focus on comprehension is at the heart of…

  13. High time-resolved chemical compositions, sources and evolution for atmospheric submicron aerosols in the winter of Beijing

    NASA Astrophysics Data System (ADS)

    Min, H.; Hu, W.; Zheng, J.; Guo, S.; Wu, Y.; Zeng, L.; Lu, S.; Xie, S.; Zhang, Y.

    2017-12-01

    Severe regional haze problem in the megacity Beijing and surrounding areas has attracted much attention in recent years. In order to investigate the secondary formation and aging process of urban aerosols, intensive campaigns were conducted in the winter of 2010 and 2013 at an urban site in Beijing. An Aerodyne high resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS) was deployed to measure chemical components of PM1, coupled with multiple state of the art online instruments. In the winter of 2010, PM1 mass concentrations changed dramatically along with meteorological conditions. The high average fraction (58%) of primary species in PM1 indicated that primary emissions usually played a more important role. Based on the source apportionment results, 45% POA are from non-fossil sources, contributed by cooking OA and biomass burning OA (BBOA). Cooking OA, accounting for 13-24% of OA, is an important non-fossil carbon source in all years of Beijing and should not be neglected. The fossil sources of POA include hydrocarbon-like OA from vehicle emissions and coal combustion OA (CCOA). The CCOA and BBOA were the two main contributors (57% of OA) for the highest OA concentrations (>100 μg m-3). In the winter of 2013, OOA (MO-OOA and LO-OOA), accounted for 50% of PM1, while (OOA+SNA) contributed 60-80%, suggesting that secondary formation played an important role in the PM pollution. In the winter of 2010 higher OOA/Ox (= NO2 + O3) ratio (0.49 μg m-3 ppb-1) than these ratios from western cities (0.03-0.16 μg m-3 ppb-1) was observed, which may be due to the aqueous reaction or extra SOA formation contributed by semi-VOCs from various primary sources (e.g., BBOA or CCOA). However, aqueous chemistry resulting in efficient secondary formation during occasional periods with high relative humidity may also contribute substantially to haze in winter. CCOA was only identified in winter due to domestic heating. These results signified that the comprehensive management for biomass burning and coal combustion emissions is needed. Further strengthening the regional emission control of primary particulate and precursors of secondary species is expected.

  14. Going Back to School

    ERIC Educational Resources Information Center

    Coffield, Frank

    2010-01-01

    The Cambridge Primary Review is a monumental achievement, a comprehensive and far-sighted review of the primary school system in England. What possible relevance could a major report on primary education hold for the post-compulsory sector? In this article, the author shares his four answers to this question. Furthermore, he describes briefly the…

  15. A Cross-Sectional Comparison of Perceived Quality of Primary Care by Hypertensive Patients in Shanghai and Shenzhen, China

    PubMed Central

    Li, Haitao; Wei, Xiaolin; Wong, Martin Chi-Sang; Wong, Samuel Yeung-Shan; Yang, Nan; Griffiths, Sian M.

    2015-01-01

    Abstract Hypertension should be best managed under primary care settings. This study aimed to compare, between Shanghai and Shenzhen, the perceived quality of primary care in terms of accessibility, continuity, co-ordination, and comprehensiveness among hypertensive patients. A cross-sectional study was conducted in Shanghai and Shenzhen, China. Multistage random sampling method was used to select 8 community health centers. Data from primary care users were collected through on-site face-to-face interviews using the primary care assessment tool. Good quality standard was set as a value of 3 for each attribute and a value of 18 for total score. We included 568 patients in Shanghai and 128 patients in Shenzhen. Compared with those in Shenzhen, hypertensive patients in Shanghai reported a higher score in co-ordination of information (3.37 vs 3.66; P < 0.001), but lower scores in continuity of care (3.36 vs 3.27; P < 0.001), and comprehensiveness-service provision (3.26 vs 2.79; P < 0.001). There was no statistically significant difference in total scores between the 2 cities (18.19 vs 18.15). Over 3-quarters of hypertensive patients in both cities reported accessibility (97.2% vs 91.4%) and co-ordination of services (76.1% vs 80.5%) under good quality standard, while <1-quarter of them rated continuity of care (23.6% vs 22.7%), co-ordination of information (4.8% vs 21.1%), and comprehensiveness-service availability (15.1% vs 25.0%) under that standard. Compared with Shenzhen, the perceived quality of primary care for hypertensive patients in Shanghai was better in terms of co-ordination of information, but poorer on continuity of care and comprehensiveness-service provision. Our study suggests that there is room for quality improvement in both cities. PMID:26313780

  16. Impacts of traffic emissions on atmospheric particulate nitrate and organics at a downwind site on the periphery of Guangzhou, China

    NASA Astrophysics Data System (ADS)

    Qin, Yi Ming; Tan, Hao Bo; Jie Li, Yong; Schurman, Misha I.; Li, Fei; Canonaco, Francesco; Prévôt, André S. H.; Chan, Chak K.

    2017-09-01

    Particulate matter (PM) pollution on the peripheries of Chinese megacities can be as serious as in cities themselves. Given the substantial vehicular emissions in inner-city areas, the direct transport of primary PM (e.g., black carbon and primary organics) and effective formation of secondary PM from precursors (e.g., NOx and volatile organic compounds) can contribute to PM pollution in buffer zones between cities. To investigate how traffic emissions in inner-city areas impact these adjacent buffer zones, a suite of real-time instruments were deployed in Panyu, downwind from central Guangzhou, from November to December 2014. Nitrate mass fraction was higher on high-PM days, with the average nitrate-to-sulfate ratio increasing from around 0.35 to 1.5 as the PM mass concentration increased from 10 to 160 µg m-3. Particulate nitrate was strongly correlated with excess ammonium (([NH4+] / [SO42-] - 1.5) × [SO42-]), with higher concentrations in December than in November due to lower temperatures. The organic mass fraction was the highest across all PM1 levels throughout the campaign. While organic aerosols (OA) were dominated by secondary organic aerosols (SOA = semi-volatile oxygenated organic aerosols + low-volatility oxygenated organic aerosols) as a campaign average, freshly emitted hydrocarbon-like organic aerosols (HOA) contributed up to 40 % of OA during high-OA periods, which typically occurred at nighttime and contributed 23.8 to 28.4 % on average. This was due to daytime traffic restrictions on heavy-duty vehicles in Guangzhou, and HOA almost increased linearly with total OA concentration. SOA increased as odd oxygen (Ox = O3 + NO2) increased during the day due to photochemistry. A combination of nighttime traffic emissions and daytime photochemistry contributed to the buildup of PM in Panyu. The mitigation of PM pollution in inner-city areas by reducing vehicular traffic can potentially improve air quality in peripheral areas.

  17. Characterizing particulate matter emissions from vehicles: chassis-dynamometer tests using a High-Resolution Aerosol Mass Spectrometer

    NASA Astrophysics Data System (ADS)

    Collier, S.; Zhang, Q.; Forestieri, S.; Kleeman, M.; Cappa, C. D.; Kuwayama, T.

    2012-12-01

    During September of 2011 a suite of real-time instruments was used to sample vehicle emissions at the California Air Resources Board Haagen-Schmidt facility in El Monte, CA. A representative fleet of 8 spark ignition gasoline vehicles, a diesel passenger vehicle, a gasoline direct-injection vehicle and an ultra-low emissions vehicle were tested on a chassis dynamometer. The emissions were sampled into the facility's standard CVS tunnel and diluted to atmospherically relevant levels (5-30 μg/m3) while controlling other factors such as relative humidity or background black carbon particulate loading concentrations. An Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-MS) was among the real-time instruments used and sampled vehicle emissions at 10 second time resolution in order to characterize the non-refractory organic and inorganic particulate matter (PM). PM composition and concentration were tracked throughout the cold start driving cycle which included periods of fast acceleration and high velocity cruise control, meant to recreate typical commuter driving behavior. Variations in inorganic and organic PM composition for a given vehicle throughout the driving cycle as well as for various vehicles with differing emissions loading were characterized. Differences in PM composition for a given vehicle whose emissions are being exposed to differing experimental conditions such as varying relative humidity will also be reported. In conjunction with measurements from a Multi Wavelength Photoacoustic Black Carbon Spectrometer (MWPA-BC) and real-time gas measurements from the CARB facility, we determine the real-time emission ratios of primary organic aerosols (POA) with respect to BC and common combustion gas phase pollutants and compared to different vehicle driving conditions. The results of these tests offer the vehicle emissions community a first time glimpse at the real-time behavior of vehicle PM emissions for a variety of conditions and vehicle types at atmospherically relevant conditions and without chemical interferences from other primary or secondary aerosol sources.

  18. Managing the Mission: The Primary Challenge to Campus Child Care.

    ERIC Educational Resources Information Center

    Townley, Kim F.; Zeece, Pauline Davey

    1991-01-01

    Examines complex issues and challenges faced by a comprehensive child care system in its efforts to meet its teaching, research, and service missions. These issues and challenges are examined in terms of an expanded, integrated model for comprehensive child care. (SH)

  19. Prolonged Particulate Hexavalent Chromium Exposure Suppresses Homologous Recombination Repair in Human Lung Cells.

    PubMed

    Browning, Cynthia L; Qin, Qin; Kelly, Deborah F; Prakash, Rohit; Vanoli, Fabio; Jasin, Maria; Wise, John Pierce

    2016-09-01

    Genomic instability is one of the primary models of carcinogenesis and a feature of almost all cancers. Homologous recombination (HR) repair protects against genomic instability by maintaining high genomic fidelity during the repair of DNA double strand breaks. The defining step of HR repair is the formation of the Rad51 nucleofilament, which facilitates the search for a homologous sequence and invasion of the template DNA strand. Particulate hexavalent chromium (Cr(VI)), a human lung carcinogen, induces DNA double strand breaks and chromosome instability. Since the loss of HR repair increases Cr(VI)-induced chromosome instability, we investigated the effect of extended Cr(VI) exposure on HR repair. We show acute (24 h) Cr(VI) exposure induces a normal HR repair response. In contrast, prolonged (120 h) exposure to particulate Cr(VI) inhibited HR repair and Rad51 nucleofilament formation. Prolonged Cr(VI) exposure had a profound effect on Rad51, evidenced by reduced protein levels and Rad51 mislocalization to the cytoplasm. The response of proteins involved in Rad51 nuclear import and nucleofilament formation displayed varying responses to prolonged Cr(VI) exposure. BRCA2 formed nuclear foci after prolonged Cr(VI) exposure, while Rad51C foci formation was suppressed. These results suggest that particulate Cr(VI), a major chemical carcinogen, inhibits HR repair by targeting Rad51, causing DNA double strand breaks to be repaired by a low fidelity, Rad51-independent repair pathway. These results further enhance our understanding of the underlying mechanism of Cr(VI)-induced chromosome instability and thus, carcinogenesis. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  20. Advances in Satellite Remote Sensing of Particulate Air Pollution: From MISR to MAIA

    NASA Astrophysics Data System (ADS)

    Diner, D. J.; Burke, K.; Xu, F.; Garay, M. J.; Kalashnikova, O. V.; Liu, Y.; Meng, X.; Wang, J.; Martin, R.; Ostro, B.

    2017-12-01

    Airborne particulate matter (PM) is a well-known cause of cardiovascular and respiratory disease. To estimate human exposure to PM pollution, satellite instruments such as the Terra Multi-angle Imaging SpectroRadiometer (MISR) and the Moderate resolution Imaging Spectroradiometer (MODIS) have been used in conjunction with surface monitors to map near-surface PM concentrations. The relative toxicity of different size and compositional mixtures of PM is not well understood. To address this, we are developing the Multi-Angle Imager for Aerosols (MAIA) investigation. The satellite instrument extends MISR's multiangular visible and near-infrared (VNIR) spectral coverage to 14 bands in the ultraviolet, VNIR, and shortwave IR; three of the bands are polarimetric to enhance sensitivity to aerosol size and composition. To constrain the retrievals, the observations will be combined with data from surface monitors and the WRF-Chem and GEOS-Chem chemical transport models. Existing surface PM speciation monitors will be supplemented by adding new stations to the Surface PARTiculate mAtter Network (SPARTAN). Unlike MISR, MAIA is a targeting instrument. Primary areas of interest include metropolitan areas in North and South America, Europe, the Middle East, Africa, India, and East Asia. PM retrieval algorithms are being developed using data from MISR and the high-altitude Airborne Multiangle SpectroPolarimetric Imager (AirMSPI). Epidemiologists on the MAIA science team will use the derived PM data products and birth, death, and hospital records to investigate adverse health impacts of different types of airborne particulates. MAIA's earliest possible launch date is mid-2020, making it possible for the data to be complemented by global observations from Terra as well as high temporal resolution atmospheric chemistry measurements from TEMPO (Tropospheric Emissions: Monitoring Pollution), GEMS (Geostationary Environment Monitoring Spectrometer), and Sentinel-4.

  1. Proximate composition of poultry processing wastewater particulate matter from broiler slaughter plants.

    PubMed

    Kiepper, B H; Merka, W C; Fletcher, D L

    2008-08-01

    An experiment was conducted to compare the proximate composition of particulate matter recovered from poultry processing wastewater (PPW) generated by broiler slaughter plants. Poultry processing wastewater is the cumulative wastewater stream generated during the processing of poultry following primary and secondary physical screening (typically to 500 mum) that removes gross offal. Composite samples of PPW from 3 broiler slaughter plants (southeast United States) were collected over 8 consecutive weeks. All 3 broiler slaughter plants process young chickens with an average live weight of 2.0 kg. At each plant, a single 72-L composite sample was collected using an automatic sampler programmed to collect 1 L of wastewater every 20 min for 24 h during one normal processing day each week. Each composite sample was thoroughly mixed, and 60 L was passed through a series of sieves (2.0 mm, 1.0 mm, 500 mum, and 53 mum). The amount of particulate solids collected on the 2.0 mm, 1.0 mm, and 500 mum sieves was insignificant. The solids recovered from the 53-mum sieve were subjected to proximate analysis to determine percent moisture, fat, protein, ash, and fiber. The average percentages of fat, protein, ash, and fiber for all samples on a dry-weight basis were 55.3, 27.1, 6.1, and 4.1, respectively. Fat made up over half of the dry-weight matter recovered, representing PPW particulate matter between 500 and 53 mum. Despite the variation in number of birds processed daily, further processing operations, and number and type of wastewater screens utilized, there were no significance differences in percentage of fat and fiber between the slaughter plants. There were significant differences in percent protein and ash between the slaughter plants.

  2. Enhanced levels of atmospheric low-molecular weight monocarboxylic acids in gas and particulates over Mt. Tai, North China, during field burning of agricultural wastes

    NASA Astrophysics Data System (ADS)

    Mochizuki, Tomoki; Kawamura, Kimitaka; Nakamura, Shinnosuke; Kanaya, Yugo; Wang, Zifa

    2017-12-01

    To understand the source and atmospheric behaviour of low molecular weight monocarboxylic acids (monoacids), gaseous (G) and particulate (P) organic acids were collected at the summit of Mt. Tai in the North China Plain (NCP) during field burning of agricultural waste (wheat straw). Particulate organic acids were collected with neutral quartz filter whereas gaseous organic acids were collected with KOH-impregnated quartz filter. Normal (C1-C10), branched (iC4-iC6), hydroxy (lactic and glycolic), and aromatic (benzoic) monoacids were determined with a capillary gas chromatography employing p-bromophenacyl esters. We found acetic acid as the most abundant gas-phase species whereas formic acid is the dominant particle-phase species. Concentrations of formic (G/P 1 570/1 410 ng m-3) and acetic (3 960/1 120 ng m-3) acids significantly increased during the enhanced field burning of agricultural wastes. Concentrations of formic and acetic acids in daytime were found to increase in both G and P phases with those of K+, a field-burning tracer (r = 0.32-0.64). Primary emission and secondary formation of acetic acid is linked with field burning of agricultural wastes. In addition, we found that particle-phase fractions (Fp = P/(G + P)) of formic (0.50) and acetic (0.31) acids are significantly high, indicating that semi-volatile organic acids largely exist as particles. Field burning of agricultural wastes may play an important role in the formation of particulate monoacids in the NCP. High levels (917 ng m-3) of particle-phase lactic acid, which is characteristic of microorganisms, suggest that microbial activity associated with terrestrial ecosystem significantly contributes to the formation of organic aerosols.

  3. Particulate Matter Concentrations in East Oakland's High Street Corridor

    NASA Astrophysics Data System (ADS)

    Lei, P.; Jackson, J.; Lewis, R.; Marigny, A.; Mitchell, J. D.; Nguyen, R.; Philips, B.; Randle, D.; Romero, D.; Spears, D.; Telles, C.; Weissman, D.

    2012-12-01

    Particulate matter (PM) is a complex mixture of small solid pieces and/or liquid droplets in the air. High concentrations of PM can pose a serious health hazard because inhalation can result in breathing problems and/or aggravate asthma. Long term exposure can increase the likelihood of respiratory problems like asthma and emphysema as well as cancer. The smaller the particles, the deeper they can get into the respiratory system. For this reason, the smallest particles, those smaller than 2.5 micrometers in diameter (PM2.5), are the most dangerous. PM2.5 is largely emitted from motor vehicles burning fuels that don't break down fully. Our research team investigated the levels of PM2.5 as well as particles smaller than 10 micrometers (PM10) and total suspended particulate (TSP) along the northeast-southwest trending High Street Corridor, near Fremont High School in East Oakland, California. Using the Aerocet 531 mass particle counter, team members walked through neighborhoods and along major roads within a 1 mile radius of Fremont High School. The Aerocet 531 recorded two minute average measurements of all the relevant PM sizes, which are reported in mg/m3. Measurements were consistently taken in the morning, between 8:30 and 11:30 am. Preliminary results indicate maximum readings of all PM sizes at sites that are in close proximity to a major freeway (Interstate-880). These results support our initial hypothesis that proximity to major roads and freeways, especially those with high diesel-fuel burning truck traffic, would be the primary factor affecting PM concentration levels. Preliminary median and maximum readings all suggest particulate matter levels below what the EPA would consider unhealthy or risky.

  4. Primary central nervous system B-cell lymphoma in a young dog

    PubMed Central

    Kim, Na-Hyun; Ciesielski, Thomas; Kim, Jung H.; Yhee, Ji-Young; Im, Keum-Soon; Nam, Hae-Mi; Kim, Il-Hwan; Kim, Jong-Hyuk; Sur, Jung-Hyang

    2012-01-01

    This report describes a primary central nervous system B-cell lymphoma in a 3-year-old intact female Maltese dog. Canine primary central nervous system lymphomas constitute about 4% of all intracranial primary neoplasms, but comprehensive histopathologic classifications have rarely been carried out. This is the first report of this disease in a young adult dog. PMID:23115372

  5. Comparative Soot Diagnostics: 1 Year Report

    NASA Technical Reports Server (NTRS)

    Urban, David L.; Griffin, DeVon W.; Gard, Melissa Y.

    1998-01-01

    The motivation for the Comparative Soot Diagnostics (CSD) experiment lies in the broad practical importance of understanding combustion generated particulate. Depending upon the circumstances, particulate matter can affect the durability and performance of combustion equipment, can be a pollutant, can be used to detect fires and, in the form of soot, can be the dominant source of radiant energy from flames. Bright sooty fires are desirable for efficient energy extraction in furnaces and power equipment. In contrast, soot-enhanced radiation is undesirable in many propulsion systems (e.g. jet engines). The non-buoyant structure of most flames of practical interest (turbulent) makes understanding of soot processes in low gravity flames important to our ability to predict fire behavior on earth. These studies also have direct applications to fire safety in human-crew spacecraft, since smoke is the indicator used for automated detection in current spacecraft. In addition, recent tests conducted on MIR showed that a candle in a truly quiescent spacecraft environment can burn for tens of minutes. Consequently, this test and many earlier tests have demonstrated that fires in spacecraft can be considered a credible risk. In anticipation of this risk, NASA has included fire detectors on Skylab, smoke detectors on the Space Shuttle (STS), and smoke detectors in the design for the International Space Station (ISS). In the CSD experiment, these smoke detectors were tested using, quasi-steady, low-gravity, particulate generating materials. Samples of the particulate were also obtained from these low-gravity sources. This experiment provides the first such measurements aimed toward understanding of soot processes here on earth and for the testing and design of advanced spacecraft smoke detection systems. This paper describes the operation and preliminary results of the CSD experiment which was was conducted in the Middeck Glovebox Facility (MGBX) on USMP-3. The objectives of CSD are to examine the particulate emission from a variety of pyrolyzing and combusting sources and to quantify the performance of several particulate-sensing diagnostic techniques. This paper presents the results of the microgravity portion of the CSD experiment. The results include the temporal response of the detectors and average sizes of the primary and aggregate particles captured on the thermophoretic probes. Complete assessment of the microgravity data and its combination with the normal-gravity data are still in process.

  6. The strength of primary care in Europe: an international comparative study.

    PubMed

    Kringos, Dionne; Boerma, Wienke; Bourgueil, Yann; Cartier, Thomas; Dedeu, Toni; Hasvold, Toralf; Hutchinson, Allen; Lember, Margus; Oleszczyk, Marek; Rotar Pavlic, Danica; Svab, Igor; Tedeschi, Paolo; Wilm, Stefan; Wilson, Andrew; Windak, Adam; Van der Zee, Jouke; Groenewegen, Peter

    2013-11-01

    A suitable definition of primary care to capture the variety of prevailing international organisation and service-delivery models is lacking. Evaluation of strength of primary care in Europe. International comparative cross-sectional study performed in 2009-2010, involving 27 EU member states, plus Iceland, Norway, Switzerland, and Turkey. Outcome measures covered three dimensions of primary care structure: primary care governance, economic conditions of primary care, and primary care workforce development; and four dimensions of primary care service-delivery process: accessibility, comprehensiveness, continuity, and coordination of primary care. The primary care dimensions were operationalised by a total of 77 indicators for which data were collected in 31 countries. Data sources included national and international literature, governmental publications, statistical databases, and experts' consultations. Countries with relatively strong primary care are Belgium, Denmark, Estonia, Finland, Lithuania, the Netherlands, Portugal, Slovenia, Spain, and the UK. Countries either have many primary care policies and regulations in place, combined with good financial coverage and resources, and adequate primary care workforce conditions, or have consistently only few of these primary care structures in place. There is no correlation between the access, continuity, coordination, and comprehensiveness of primary care of countries. Variation is shown in the strength of primary care across Europe, indicating a discrepancy in the responsibility given to primary care in national and international policy initiatives and the needed investments in primary care to solve, for example, future shortages of workforce. Countries are consistent in their primary care focus on all important structure dimensions. Countries need to improve their primary care information infrastructure to facilitate primary care performance management.

  7. Description of a novel telemedicine-enabled comprehensive system of care: drip and ship plus drip and keep within a system of stroke care delivery.

    PubMed

    Commiskey, Patricia; Afshinnik, Arash; Cothren, Elizabeth; Gropen, Toby; Iwuchukwu, Ifeanyi; Jennings, Bethany; McGrade, Harold C; Mora-Guillot, Julia; Sabharwal, Vivek; Vidal, Gabriel A; Zweifler, Richard M; Gaines, Kenneth

    2017-04-01

    United States (US) and worldwide telestroke programs frequently focus only on emergency room hyper-acute stroke management. This article describes a comprehensive, telemedicine-enabled, stroke care delivery system that combines "drip and ship" and "drip and keep" models with a comprehensive stroke center primary hub at Ochsner Medical Center in New Orleans, advanced stroke-capable regional hubs, and geographically-aligned, "stroke-ready" spokes. The primary hub provides vascular neurology expertise via telemedicine and monitors care for patients remaining at regional hubs and spokes using a multidisciplinary team approach. By 2014, primary hub telestroke consults grew to ≈1000/year with 16 min average door to consult initiation and 20 min to completion, and 29% of ischemic stroke patients received recombinant tissue-type plasminogen activator (rtPA), increasing 275%. Most patients remained in hospitals close to home, but neurointensive care and interventional procedures were common reasons for primary hub transfer. Given the time sensitivity and expert consultation needed for complex acute stroke care delivery paradigms, telestroke programs are effective for fulfilling unmet care needs. Combining drip and ship and drip and keep management allows more patients to stay "local," limiting primary hub transfer unless more advanced services are required. Post admission telestroke management at spokes increases personnel efficiency and can positively impact stroke outcomes.

  8. Cost-Effectiveness of Disease Management Programs for Cardiovascular Risk and COPD in The Netherlands.

    PubMed

    Tsiachristas, Apostolos; Burgers, Laura; Rutten-van Mölken, Maureen P M H

    2015-12-01

    Disease management programs (DMPs) for cardiovascular risk (CVR) and chronic obstructive pulmonary disease (COPD) are increasingly implemented in The Netherlands to improve care and patient's health behavior. The aim of this study was to provide evidence about the (cost-) effectiveness of Dutch DMPs as implemented in daily practice. We compared the physical activity, smoking status, quality-adjusted life-years, and yearly costs per patient between the most and the least comprehensive DMPs in four disease categories: primary CVR prevention, secondary CVR prevention, both types of CVR prevention, and COPD (N = 1034). Propensity score matching increased comparability between DMPs. A 2-year cost-utility analysis was performed from the health care and societal perspectives. Sensitivity analysis was performed to estimate the impact of DMP development and implementation costs on cost-effectiveness. Patients in the most comprehensive DMPs increased their physical activity more (except for primary CVR prevention) and had higher smoking cessation rates. The incremental QALYs ranged from -0.032 to 0.038 across all diseases. From a societal perspective, the most comprehensive DMPs decreased costs in primary CVR prevention (certainty 57%), secondary CVR prevention (certainty 88%), and both types of CVR prevention (certainty 98%). Moreover, the implementation of comprehensive DMPs led to QALY gains in secondary CVR prevention (certainty 92%) and COPD (certainty 69%). The most comprehensive DMPs for CVR and COPD have the potential to be cost saving, effective, or cost-effective compared with the least comprehensive DMPs. The challenge for Dutch stakeholders is to find the optimal mixture of interventions that is most suited for each target group. Copyright © 2015 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  9. Comprehensive primary health care under neo-liberalism in Australia.

    PubMed

    Baum, Fran; Freeman, Toby; Sanders, David; Labonté, Ronald; Lawless, Angela; Javanparast, Sara

    2016-11-01

    This paper applies a critical analysis of the impact of neo-liberal driven management reform to examine changes in Australian primary health care (PHC) services over five years. The implementation of comprehensive approaches to primary health care (PHC) in seven services: five state-managed and two non-government organisations (NGOs) was tracked from 2009 to 2014. Two questions are addressed: 1) How did the ability of Australian PHC services to implement comprehensive PHC change over the period 2009-2014? 2) To what extent is the ability of the PHC services to implement comprehensive PHC shaped by neo-liberal health sector reform processes? The study reports on detailed tracking and observations of the changes and in-depth interviews with 63 health service managers and practitioners, and regional and central health executives. The documented changes were: in the state-managed services (although not the NGOs) less comprehensive service coverage and more focus on clinical services and integration with hospitals and much less development activity including community development, advocacy, intersectoral collaboration and attention to the social determinants. These changes were found to be associated with practices typical of neo-liberal health sector reform: considerable uncertainty, more directive managerial control, budget reductions and competitive tendering and an emphasis on outputs rather than health outcomes. We conclude that a focus on clinical service provision, while highly compatible with neo-liberal reforms, will not on its own produce the shifts in population disease patterns that would be required to reduce demand for health services and promote health. Comprehensive PHC is much better suited to that task. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. The relevance of receptive vocabulary in reading comprehension.

    PubMed

    Nalom, Ana Flávia de Oliveira; Soares, Aparecido José Couto; Cárnio, Maria Silvia

    2015-01-01

    To characterize the performance of students from the 5th year of primary school, with and without indicatives of reading and writing disorders, in receptive vocabulary and reading comprehension of sentences and texts, and to verify possible correlations between both. This study was approved by the Research Ethics Committee of the institution (no. 098/13). Fifty-two students in the 5th year from primary school, with and without indicatives of reading and writing disorders, and from two public schools participated in this study. After signing the informed consent and having a speech therapy assessment for the application of inclusion criteria, the students were submitted to a specific test for standardized evaluation of receptive vocabulary and reading comprehension. The data were studied using statistical analysis through the Kruskal-Wallis test, analysis of variance techniques, and Spearman's rank correlation coefficient with level of significance to be 0.05. A receiver operating characteristic (ROC) curve (was constructed in which reading comprehension was considered as gold standard. The students without indicatives of reading and writing disorders presented a better performance in all tests. No significant correlation was found between the tests that evaluated reading comprehension in either group. A correlation was found between reading comprehension of texts and receptive vocabulary in the group without indicatives. In the absence of indicatives of reading and writing disorders, the presence of a good range of vocabulary highly contributes to a proficient reading comprehension of texts.

  11. Tobacco Smoke Pollution in Hospitality Venues Before and After Passage of Statewide Smoke-Free Legislation.

    PubMed

    Buettner-Schmidt, Kelly; Boursaw, Blake; Lobo, Marie L; Travers, Mark J

    2017-03-01

    In 2012, North Dakota enacted a comprehensive statewide law prohibiting smoking in enclosed public places. Disparities in tobacco control exist in rural areas. This study's objective was to determine the extent to which the passage of a comprehensive, statewide, smoke-free law in a predominantly rural state influenced tobacco smoke pollution in rural and nonrural venues. A longitudinal cohort design study comparing the levels of tobacco smoke pollution before and after passage of the statewide smoke-free law was conducted in 64 restaurants and bars statewide in North Dakota. Particulate matter with a median aerodynamic diameter of <2.5 μm (a valid atmospheric marker of tobacco smoke pollution) was assessed. A significant 83% reduction in tobacco smoke pollution levels occurred after passage of the law. Significant reductions in tobacco smoke pollution levels occurred in each of the rural categories; however, no difference by rurality was noted in the analysis after passage of the law, in contrast to the study before passage. To our knowledge, this was the largest, single, rural postlaw study globally. A comprehensive statewide smoke-free law implemented in North Dakota dramatically decreased the level of tobacco smoke pollution in bars and restaurants. © 2016 The Authors. Public Health Nursing Published by Wiley Periodicals, Inc.

  12. Listening Comprehension: A Cognitive Prerequisite for Communication.

    ERIC Educational Resources Information Center

    Fischer, Robert A.

    Proponents of the cognitive approach to language teaching list linguistic competence as the primary instructional objective and attribute considerable importance to listening comprehension. For the student, linguistic competence would be knowledge of grammatical components of the language and its vocabulary. Understanding oral messages is an…

  13. Developing Reading Comprehension through Collaborative Learning

    ERIC Educational Resources Information Center

    Rojas-Drummond, Sylvia; Mazón, Nancy; Littleton, Karen; Vélez, Maricela

    2014-01-01

    The present study explores the development and promotion of reading comprehension in primary school students, in the context of the implementation of an educational programme called "Learning Together" (LT). The programme, which centred on collaborative learning activities, was designed to promote oral and written communication in…

  14. Sequential-Simultaneous Processing and Reading Skills in Primary Grade Children.

    ERIC Educational Resources Information Center

    McRae, Sandra G.

    1986-01-01

    The study examined relationships between two modes of information processing, simultaneous and sequential, and two sets of reading skills, word recognition and comprehension, among 40 second and third grade students. Results indicated there is a relationship between simultaneous processing and reading comprehension. (Author)

  15. Brief assessments and screening for geriatric conditions in older primary care patients: a pragmatic approach.

    PubMed

    Seematter-Bagnoud, Laurence; Büla, Christophe

    2018-01-01

    This paper discusses the rationale behind performing a brief geriatric assessment as a first step in the management of older patients in primary care practice. While geriatric conditions are considered by older patients and health professionals as particularly relevant for health and well-being, they remain too often overlooked due to many patient- and physician-related factors. These include time constraints and lack of specific training to undertake comprehensive geriatric assessment. This article discusses the epidemiologic rationale for screening functional, cognitive, affective, hearing and visual impairments, and nutritional status as well as fall risk and social status. It proposes using brief screening tests in primary care practice to identify patients who may need further comprehensive geriatric assessment or specific interventions.

  16. Comprehension of concrete and abstract words in semantic variant primary progressive aphasia and Alzheimer's disease: A behavioral and neuroimaging study.

    PubMed

    Joubert, Sven; Vallet, Guillaume T; Montembeault, Maxime; Boukadi, Mariem; Wilson, Maximiliano A; Laforce, Robert Jr; Rouleau, Isabelle; Brambati, Simona M

    2017-07-01

    The aim of this study was to investigate the comprehension of concrete, abstract and abstract emotional words in semantic variant primary progressive aphasia (svPPA), Alzheimer's disease (AD), and healthy elderly adults (HE) Three groups of participants (9 svPPA, 12 AD, 11 HE) underwent a general neuropsychological assessment, a similarity judgment task, and structural brain MRI. The three types of words were processed similarly in the group of AD participants. In contrast, patients in the svPPA group were significantly more impaired at processing concrete words than abstract words, while comprehension of abstract emotional words was in between. VBM analyses showed that comprehension of concrete words relative to abstract words was significantly correlated with atrophy in the left anterior temporal lobe. These results support the view that concrete words are disproportionately impaired in svPPA, and that concrete and abstract words may rely upon partly dissociable brain regions. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Developing a Universal Reading Comprehension Intervention for Mainstream Primary Schools within Areas of Social Deprivation for Children with and without Language-Learning Impairment: A Feasibility Study

    ERIC Educational Resources Information Center

    McCartney, Elspeth; Boyle, James; Ellis, Sue

    2015-01-01

    Background: Some children in areas of social deprivation in Scotland have lower reading attainment than neighbouring children in less deprived areas, and some of these also have lower spoken language comprehension skills than expected by assessment norms. There is a need to develop effective reading comprehension interventions that fit easily into…

  18. Process for reducing organic compounds with calcium, amine, and alcohol

    DOEpatents

    Benkeser, Robert A.; Laugal, James A.; Rappa, Angela

    1985-01-01

    Olefins are produced by contacting an organic compound having at least one benzene ring with calcium metal, ethylenediamine, a low molecular weight aliphatic alcohol, and optionally a low molecular weight aliphatic primary amine, and/or an inert, abrasive particulate substance. The reduction is conducted at temperatures ranging from about -10.degree. C. to about 30.degree. C. or somewhat higher. Substantially all of the organic compounds are converted to corresponding cyclic olefins, primarily diolefins.

  19. Space Station Induced Monitoring

    NASA Technical Reports Server (NTRS)

    Spann, James F. (Editor); Torr, Marsha R. (Editor)

    1988-01-01

    This report contains the results of a conference convened May 10-11, 1988, to review plans for monitoring the Space Station induced environment, to recommend primary components of an induced environment monitoring package, and to make recommendations pertaining to suggested modifications of the Space Station External Contamination Control Requirements Document JSC 30426. The contents of this report are divided as Follows: Monitoring Induced Environment - Space Station Work Packages Requirements, Neutral Environment, Photon Emission Environment, Particulate Environment, Surface Deposition/Contamination; and Contamination Control Requirements.

  20. Effectiveness of mitigation measures in reducing future primary particulate matter emissions from on-road vehicle exhaust.

    PubMed

    Yan, Fang; Bond, Tami C; Streets, David G

    2014-12-16

    This work evaluates the effectiveness of on-road primary particulate matter emission reductions that can be achieved by long-term vehicle scrappage and retrofit measures on regional and global levels. Scenario analysis shows that scrappage can provide significant emission reductions as soon as the measures begin, whereas retrofit provides greater emission reductions in later years, when more advanced technologies become available in most regions. Reductions are compared with a baseline that already accounts for implementation of clean vehicle standards. The greatest global emission reductions from a scrappage program occur 5 to 10 years after its introduction and can reach as much as 70%. The greatest reductions with retrofit occur around 2030 and range from 16-31%. Monte Carlo simulations are used to evaluate how uncertainties in the composition of the vehicle fleet affect predicted reductions. Scrappage and retrofit reduce global emissions by 22-60% and 15-31%, respectively, within 95% confidence intervals, under a midrange scenario in the year 2030. The simulations provide guidance about which strategies are most effective for specific regions. Retrofit is preferable for high-income regions. For regions where early emission standards are in place, scrappage is suggested, followed by retrofit after more advanced emission standards are introduced. The early implementation of advanced emission standards is recommended for Western and Eastern Africa.

  1. Effectiveness of Mitigation Measures in Reducing Future Primary Particulate Matter Emissions from On-Road Vehicle Exhaust

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yan, Fang; Bond, Tami C.; Streets, David G.

    This work evaluates the effectiveness of on-road primary particulate matter emission reductions that can be achieved by long-term vehicle scrappage and retrofit measures on regional and global levels. Scenario analysis shows that scrappage can provide significant emission reductions as soon as the measures begin, whereas retrofit provides greater emission reductions in later years, when more advanced technologies become available in most regions. Reductions are compared with a baseline that already accounts for implementation of clean vehicle standards. The greatest global emission reductions from a scrappage program occur 5 to 10 years after its introduction and can reach as much asmore » 70%. The greatest reductions with retrofit occur around 2030 and range from 16-31%. Monte Carlo simulations are used to evaluate how uncertainties in the composition of the vehicle fleet affect predicted reductions. Scrappage and retrofit reduce global emissions by 22-60% and 15-31%, respectively, within 95% confidence intervals, under a midrange scenario in the year 2030. The simulations provide guidance about which strategies are most effective for specific regions. Retrofit is preferable for high-income regions. For regions where early emission standards are in place, scrappage is suggested, followed by retrofit after more advanced emission standards are introduced. The early implementation of advanced emission standards is recommended for Western and Eastern Africa« less

  2. Study of particulate matter from Primary/Secondary Marine Aerosol and anthropogenic sources collected by a self-made passive sampler for the evaluation of the dry deposition impact on built heritage.

    PubMed

    Morillas, Héctor; Maguregui, Maite; García-Florentino, Cristina; Marcaida, Iker; Madariaga, Juan Manuel

    2016-04-15

    Dry deposition is one of the most dangerous processes that can take place in the environment where the compounds that are suspended in the atmosphere can react directly on different surrounding materials, promoting decay processes. Usually this process is related with industrial/urban fog and/or marine aerosol in the coastal areas. Particularly, marine aerosol transports different types of salts which can be deposited on building materials and by dry deposition promotes different decay pathways. A new analytical methodology based on the combined use of Raman Spectroscopy and SEM-EDS (point-by-point and imaging) was applied. For that purpose, firstly evaporated seawater (presence of Primary Marine Aerosol (PMA)) was analyzed. After that, using a self-made passive sampler (SMPS), different suspended particles coming from marine aerosol (transformed particles in the atmosphere (Secondary Marine Aerosol (SMA)) and metallic airborne particulate matter coming from anthropogenic sources, were analyzed. Finally in order to observe if SMA and metallic particles identified in the SMPS can be deposited on a building, sandstone samples from La Galea Fortress (Getxo, north of Spain) located in front of the sea and in the place where the passive sampler was mounted were analyzed. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Net ecosystem production: A comprehensive measure of net carbon accumulation by ecosystems

    USGS Publications Warehouse

    Randerson, J.T.; Chapin, F. S.; Harden, J.W.; Neff, J.C.; Harmon, M.E.

    2002-01-01

    The conceptual framework used by ecologists and biogeochemists must allow for accurate and clearly defined comparisons of carbon fluxes made with disparate techniques across a spectrum of temporal and spatial scales. Consistent with usage over the past four decades, we define "net ecosystem production" (NEP) as the net carbon accumulation by ecosystems. Past use of this term has been ambiguous, because it has been used conceptually as a measure of carbon accumulation by ecosystems, but it has often been calculated considering only the balance between gross primary production (GPP) and ecosystem respiration. This calculation ignores other carbon fluxes from ecosystems (e.g., leaching of dissolved carbon and losses associated with disturbance). To avoid conceptual ambiguities, we argue that NEP be defined, as in the past, as the net carbon accumulation by ecosystems and that it explicitly incorporate all the carbon fluxes from an ecosystem, including autotrophic respiration, heterotrophic respiration, losses associated with disturbance, dissolved and particulate carbon losses, volatile organic compound emissions, and lateral transfers among ecosystems. Net biome productivity (NBP), which has been proposed to account for carbon loss during episodic disturbance, is equivalent to NEP at regional or global scales. The multi-scale conceptual framework we describe provides continuity between flux measurements made at the scale of soil profiles and chambers, forest inventories, eddy covariance towers, aircraft, and inversions of remote atmospheric flask samples, allowing a direct comparison of NEP estimates made at all temporal and spatial scales.

  4. Size-fractionated dissolved primary production and carbohydrate composition of the coccolithophore Emiliania huxleyi

    NASA Astrophysics Data System (ADS)

    Borchard, C.; Engel, A.

    2014-11-01

    Extracellular release (ER) by phytoplankton is the major source of fresh dissolved organic carbon (DOC) in marine ecosystems and accompanies primary production during all growth phases. Little is known, so far, on size and composition of released molecules, and to which extent ER occurs passively, by leakage, or actively, by exudation. Here, we report on ER by the widespread and bloom-forming coccolithophore Emiliania huxleyi grown under steady state conditions in phosphorus controlled chemostats (N : P = 29, growth rate of μ = 0.2 d-1). 14C incubations were accomplished to determine primary production (PP), comprised by particulate (PO14C) and dissolved organic carbon (DO14C), and the concentration and composition of particulate combined carbohydrates (pCCHO), and of high molecular weight (>1 kDa, HMW) dissolved combined carbohydrates (dCCHO) as major components of ER. Information on size distribution of ER products was obtained by investigating distinct size classes (<0.40 μm, <1000 kDa, <100 kDa and <10 kDa) of DO14C and HMW-dCCHO. Our results revealed relatively low ER during steady state growth, corresponding to ∼4.5% of primary production, and similar ER rates for all size classes. Acidic sugars had a significant share on freshly produced pCCHO as well as on HMW-dCCHO. While pCCHO and the smallest size (<10 kDa) fraction of HMW-dCCHO exhibited a similar sugar composition, dominated by high percentages of glucose (74-80 Mol%), the composition of HMW-dCCHO size-classes >10 kDa was significantly different with higher Mol% of arabinose. Mol% of acidic sugars increased and Mol% glucose decreased with increasing size of HMW-dCCHO. We conclude that larger polysaccharides follow different production and release pathways than smaller molecules, potentially serving distinct ecological and biogeochemical functions.

  5. Abundance of the iron containing biomolecule, heme b, during the progression of a spring phytoplankton bloom in a mesocosm experiment

    PubMed Central

    Bellworthy, Jessica; Esposito, Mario; Achterberg, Eric P.

    2017-01-01

    Concentrations of heme b were determined in a mesocosm experiment situated in Gullmar Fjord off Sweden. The mesocosm experiment lasted for ca. one hundred days and was characterised by the growth of a primary nutrient replete and a secondary nutrient deplete phytoplankton bloom. Heme b varied between 40 ± 10 pmol L-1 in the prebloom period up to a maximum of 700 ± 400 pmol L-1 just prior to the time of the primary chlorophyll a maximum. Thereafter, heme b concentrations decreased again to an average of 120 ± 60 pmol L-1. When normalised to total particulate carbon, heme b was most abundant during the initiation of the nutrient replete spring bloom, when ratios reached 52 ± 24 μmol mol-1; ten times higher than values observed both pre and post the primary bloom. Concentrations of heme b correlated with those of chlorophyll a. Nevertheless, differences were observed in the relative concentrations of the two parameters, with heme b concentrations increasing relative to chlorophyll a during the growth of the primary bloom, decreasing over the period of the secondary bloom and increasing again through the latter period of the experiment. Heme b abundance was therefore influenced by nutrient concentrations and also likely by changing community composition. In half of the mesocosms, pCO2 was elevated and maintained at ca.1000 μatm, however we observed no significant differences between heme b in plus or ambient pCO2 mesocosms, either in absolute terms, or relative to total particulate carbon and chlorophyll a. The results obtained in this study contribute to our understanding of the distribution of this significant component of the biogenic iron pool, and provide an iron replete coastal water end member that aids the interpretation of the distributions of heme b in more iron deplete open ocean waters. PMID:28426768

  6. Size-fractionated dissolved primary production and carbohydrate composition of the coccolithophore Emiliania huxleyi

    NASA Astrophysics Data System (ADS)

    Borchard, C.; Engel, A.

    2015-02-01

    Extracellular release (ER) by phytoplankton is the major source of fresh dissolved organic carbon (DOC) in marine ecosystems and accompanies primary production during all growth phases. Little is known, so far, on size and composition of released molecules, and to which extent ER occurs passively, by leakage, or actively, by exudation. Here, we report on ER by the widespread and bloom-forming coccolithophore Emiliania huxleyi grown under steady-state conditions in phosphorus-controlled chemostats (N:P = 29, growth rate of μ = 0.2 d-1) at present-day and high-CO2 concentrations. 14C incubations were performed to determine primary production (PP), comprised of particulate (PO14C) and dissolved organic carbon (DO14C). Concentration and composition of particulate combined carbohydrates (pCCHO) and high-molecular-weight (>1 kDa, HMW) dissolved combined carbohydrates (dCCHO) were determined by ion chromatography. Information on size distribution of ER products was obtained by investigating distinct size classes (<0.4 μm (DO14C), <0.45 μm (HMW-dCCHO), <1000, <100 and <10 kDa) of DO14CC and HMW-dCCHO. Our results revealed relatively low ER during steady-state growth, corresponding to ~4.5% of primary production, and similar ER rates for all size classes. Acidic sugars had a significant share on freshly produced pCCHO as well as on HMW-dCCHO. While pCCHO and the smallest size fraction (<10 kDa) of HMW-dCCHO exhibited a similar sugar composition, dominated by high percentage of glucose (74-80 mol%), the composition of HMW-dCCHO size classes >10 kDa was significantly different, with a higher mol% of arabinose. The mol% of acidic sugars increased and that of glucose decreased with increasing size of HMW-dCCHO. We conclude that larger polysaccharides follow different production and release pathways than smaller molecules, potentially serving distinct ecological and biogeochemical functions.

  7. Characterization of high explosive particles using cluster secondary ion mass spectrometry.

    PubMed

    Gillen, Greg; Mahoney, Christine; Wight, Scott; Lareau, Richard

    2006-01-01

    The use of secondary ion mass spectrometry (SIMS) for the detection and spatially resolved analysis of individual high explosive particles is described. A C(8) (-) carbon cluster primary ion beam was used in a commercial SIMS instrument to analyze samples of high explosives dispersed as particles on silicon substrates. In comparison with monatomic primary ion bombardment, the carbon cluster primary ion beam was found to greatly enhance characteristic secondary ion signals from the explosive compounds while causing minimal beam-induced degradation. The resistance of these compounds to degradation under ion bombardment allows explosive particles to be analyzed under high primary ion dose bombardment (dynamic SIMS) conditions, facilitating the rapid acquisition of spatially resolved molecular information. The use of cluster SIMS combined with computer control of the sample stage position allows for the automated identification and counting of explosive particle distributions on silicon surfaces. This will be useful for characterizing the efficiency of transfer of particulates in trace explosive detection portal collectors and/or swipes utilized for ion mobility spectrometry applications.

  8. Assessing Learning in the Primary Classroom. Understanding Primary Education Series

    ERIC Educational Resources Information Center

    Johnson, Sandra

    2011-01-01

    "Assessing Learning in the Primary Classroom" is an accessible introduction to the concepts critical to a professional understanding of this vital aspect of a teacher's role. It comprehensively considers the principles underpinning effective assessment, the different forms it can take and the different purposes it serves, both within and beyond…

  9. Websites for Primary Sources and Civics Education

    ERIC Educational Resources Information Center

    Rulli, Daniel

    2005-01-01

    This article features a list of websites for primary sources and civics education. The World Wide Web has become an excellent source for facsimiles, images, and transcriptions of primary sources. As it would be impossible to provide a comprehensive list of all the sites, this annotated list highlights selective sites that provide access to…

  10. Primary Schools and the Delivery of Relationships and Sexuality Education: The Experience of Queensland Teachers

    ERIC Educational Resources Information Center

    Johnson, Rebecca L.; Sendall, Marguerite C.; McCuaig, Louise A.

    2014-01-01

    Primary school provides an appropriate opportunity for children to commence comprehensive relationships and sexuality education (RSE), yet many primary school teachers avoid teaching this subject area. In the absence of teacher confidence and competence, schools have often relied on health promotion professionals, external agencies and/or one-off…

  11. Pediatric Primary Care as a Component of Systems of Care

    ERIC Educational Resources Information Center

    Brown, Jonathan D.

    2010-01-01

    Systems of care should be defined in a manner that includes primary care. The current definition of systems of care shares several attributes with the definition of primary care: both are defined as community-based services that are accessible, accountable, comprehensive, coordinated, culturally competent, and family focused. However, systems of…

  12. Understanding Greek Primary School Children's Comprehension of Sun Exposure.

    ERIC Educational Resources Information Center

    Piperakis, Stylianos M.; Papadimitriou, Vasiliki; Piperakis, Michael M.; Zisis, Panagiotis

    2003-01-01

    Assesses Greek primary school children's understanding of sun exposure during summer vacation. Results indicate that children know the damaging effects of long time exposure and the precautions that should be taken during summer bathing. (Author/SOE)

  13. The HMI Report on Primary Schools.

    ERIC Educational Resources Information Center

    Education in Science, 1978

    1978-01-01

    Gives a summary of a report on primary schools in England. A comprehensive survey of a representation sample of 7-, 9-, and 11- year-old pupils was conducted. The findings and their implications are considered. Recommendations are presented. (GA)

  14. Multiple Primary Cancer Monograph

    Cancer.gov

    To identify groups of cancer survivors that are at increased risk for multiple primary cancers, investigators led an effort to provide the first comprehensive population-based analysis of the risk of subsequent cancer in the U.S., resulting in a monograph.

  15. Primary care providers and medical homes for individuals with spina bifida.

    PubMed

    Walker, William O

    2008-01-01

    The contributions of primary care providers to the successful care of children with spina bifida cannot be underestimated. Overcoming systemic barriers to their integration into a comprehensive care system is essential. By providing routine and disability specific care through the structure of a Medical Home, they are often the first line resource and support for individuals and their families. The Medical Home model encourages primary care providers to facilitate discussions on topics as varied as education and employment. Knowledge of specific medical issues unique to this population allows the primary care provider to complement the efforts of other specialty clinics and providers in often neglected areas such as sexual health, obesity and latex sensitization. As individuals with spina bifida live into adulthood, and access to traditional multidisciplinary care models evolves, these skills will take on increasing importance within the scope of providing comprehensive and coordinated care.

  16. Continuous Trailing-Edge Flaps for Primary Flight Control of a Helicopter Main Rotor

    NASA Technical Reports Server (NTRS)

    Thornburgh, Robert P.; Kreshock, Andrew R.; Wilbur, Matthew L.; Sekula, Martin K.; Shen, Jinwei

    2014-01-01

    The use of continuous trailing-edge flaps (CTEFs) for primary flight control of a helicopter main rotor is studied. A practical, optimized bimorph design with Macro-Fiber Composite actuators is developed for CTEF control, and a coupled structures and computational fluid dynamics methodology is used to study the fundamental behavior of an airfoil with CTEFs. These results are used within a comprehensive rotorcraft analysis model to study the control authority requirements of the CTEFs when utilized for primary flight control of a utility class helicopter. A study of the effect of blade root pitch index (RPI) on CTEF control authority is conducted, and the impact of structural and aerodynamic model complexity on the comprehensive analysis results is presented. The results show that primary flight control using CTEFs is promising; however, a more viable option may include the control of blade RPI, as well.

  17. Overview of the reanalysis of the Harvard Six Cities Study and American Cancer Society Study of Particulate Air Pollution and Mortality.

    PubMed

    Krewski, Daniel; Burnett, Richard T; Goldberg, Mark S; Hoover, B Kristin; Siemiatycki, Jack; Jerrett, Michael; Abrahamowicz, Michal; White, Warren H

    This article provides an overview of the Reanalysis Study of the Harvard Six Cities and the American Cancer Society (ACS) studies of particulate air pollution and mortality. The previous findings of the studies have been subject to debate. In response, a reanalysis team, comprised of Canadian and American researchers, was invited to participate in an independent reanalysis project to address the concerns. Phase I of the reanalysis involved the design of data audits to determine whether each study conformed to the consistency and accuracy of their data. Phase II of the reanalysis involved conducting a series of comprehensive analyses using alternative statistical methods. Alternative models were also used to identify covariates that may confound or modify the association of particulate air pollution as well as identify sensitive population subgroups. The audit demonstrated that the data in the original analyses were of high quality, as were the risk estimates reported by the original investigators. The sensitivity analysis illustrated that the mortality risk estimates reported in both studies were found to be robust against alternative Cox models. Detailed investigation of the covariate effects found a significant modifying effect of education and a relative risk of mortality associated with fine particles and declining education levels. The study team applied spatial analytic methods to the ACS data, resulting in various levels of spatial autocorrelations supporting the reported association for fine particles mortality of the original investigators as well as demonstrating a significant association between sulfur dioxide and mortality. Collectively, our reanalysis suggest that mortality may be attributable to more than one component of the complex mixture of ambient air pollutants for U.S. urban areas.

  18. Particle Size Distributions of Particulate Emissions from the Ferroalloy Industry Evaluated by Electrical Low Pressure Impactor (ELPI)

    PubMed Central

    Kero, Ida; Naess, Mari K.; Tranell, Gabriella

    2015-01-01

    The present article presents a comprehensive evaluation of the potential use of an Electrical Low Pressure Impactor (ELPI) in the ferroalloy industry with respect to indoor air quality and fugitive emission control. The ELPI was used to assess particulate emission properties, particularly of the fine particles (Dp ≤ 1 μm), which in turn may enable more satisfactory risk assessments for the indoor working conditions in the ferroalloy industry. An ELPI has been applied to characterize the fume in two different ferroalloy plants, one producing silicomanganese (SiMn) alloys and one producing ferrosilicon (FeSi) alloys. The impactor classifies the particles according to their aerodynamic diameter and gives real-time particle size distributions (PSD). The PSD based on both number and mass concentrations are shown and compared. Collected particles have also been analyzed by transmission and scanning electron microscopy with energy dispersive spectroscopy. From the ELPI classification, particle size distributions in the range 7 nm – 10 μm have been established for industrial SiMn and FeSi fumes. Due to the extremely low masses of the ultrafine particles, the number and mass concentration PSD are significantly different. The average aerodynamic diameters for the FeSi and the SiMn fume particles were 0.17 and 0.10 μm, respectively. Based on this work, the ELPI is identified as a valuable tool for the evaluation of airborne particulate matter in the indoor air of metallurgical production sites. The method is well suited for real-time assessment of morphology (particle shape), particle size, and particle size distribution of aerosols. PMID:25380385

  19. Using Satellite Aerosol Retrievals to Monitor Surface Particulate Air Quality

    NASA Technical Reports Server (NTRS)

    Levy, Robert C.; Remer, Lorraine A.; Kahn, Ralph A.; Chu, D. Allen; Mattoo, Shana; Holben, Brent N.; Schafer, Joel S.

    2011-01-01

    The MODIS and MISR aerosol products were designed nearly two decades ago for the purpose of climate applications. Since launch of Terra in 1999, these two sensors have provided global, quantitative information about column-integrated aerosol properties, including aerosol optical depth (AOD) and relative aerosol type parameters (such as Angstrom exponent). Although primarily designed for climate, the air quality (AQ) community quickly recognized that passive satellite products could be used for particulate air quality monitoring and forecasting. However, AOD and particulate matter (PM) concentrations have different units, and represent aerosol conditions in different layers of the atmosphere. Also, due to low visible contrast over brighter surface conditions, satellite-derived aerosol retrievals tend to have larger uncertainty in urban or populated regions. Nonetheless, the AQ community has made significant progress in relating column-integrated AOD at ambient relative humidity (RH) to surface PM concentrations at dried RH. Knowledge of aerosol optical and microphysical properties, ambient meteorological conditions, and especially vertical profile, are critical for physically relating AOD and PM. To make urban-scale maps of PM, we also must account for spatial variability. Since surface PM may vary on a finer spatial scale than the resolution of standard MODIS (10 km) and MISR (17km) products, we test higher-resolution versions of MODIS (3km) and MISR (1km research mode) retrievals. The recent (July 2011) DISCOVER-AQ campaign in the mid-Atlantic offers a comprehensive network of sun photometers (DRAGON) and other data that we use for validating the higher resolution satellite data. In the future, we expect that the wealth of aircraft and ground-based measurements, collected during DISCOVER-AQ, will help us quantitatively link remote sensed and ground-based measurements in the urban region.

  20. Spatially and chemically resolved source apportionment analysis: Case study of high particulate matter event

    NASA Astrophysics Data System (ADS)

    Kim, Byeong-Uk; Bae, Changhan; Kim, Hyun Cheol; Kim, Eunhye; Kim, Soontae

    2017-08-01

    This article presents the results of a detailed source apportionment study of the high particulate matter (PM) event in the Seoul Metropolitan Area (SMA), South Korea, during late February 2014. Using the Comprehensive Air Quality Model with Extensions with its Particulate Source Apportionment Technology (CAMx-PSAT), we defined 10 source regions, including five in China, for spatially and chemically resolved analyses. During the event, the spatially averaged PM10 concentration at all PM10 monitors in the SMA was 129 μg/m3, while the PM10 and PM2.5 concentrations at the BulGwang Supersite were 143 μg/m3 and 123 μg/m3, respectively. CAMx-PSAT showed reasonably good PM model performance in both China and the SMA. For February 23-27, CAMx-PSAT estimated that Chinese contributions to the SMA PM10 and PM2.5 were 84.3 μg/m3 and 80.0 μg/m3, respectively, or 64% and 70% of the respective totals, while South Korea's respective domestic contributions were 36.5 μg/m3 and 23.3 μg/m3. We observed that the spatiotemporal pattern of PM constituent concentrations and contributions did not necessarily follow that of total PM10 and PM2.5 concentrations. For example, Beijing-Tianjin-Hebei produced high nitrate concentrations, but the two most-contributing regions to PM in the SMA were the Near Beijing area and South Korea. In addition, we noticed that the relative contributions from each region changed over time. We found that most ammonium mass that neutralized Chinese sulfate mass in the SMA came from South Korean sources, indicating that secondary inorganic aerosol in the SMA, especially ammonium sulfates, during this event resulted from different major precursors originating from different regions.

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