WorldWideScience

Sample records for sources black carbon

  1. Source attribution of black carbon in Arctic snow.

    Science.gov (United States)

    Hegg, Dean A; Warren, Stephen G; Grenfell, Thomas C; Doherty, Sarah J; Larson, Timothy V; Clarke, Antony D

    2009-06-01

    Snow samples obtained at 36 sites in Alaska, Canada, Greenland, Russia, and the Arctic Ocean in early 2007 were analyzed for light-absorbing aerosol concentration together with a suite of associated chemical species. The light absorption data, interpreted as black carbon concentrations, and other chemical data were input into the EPA PMF 1.1 receptor model to explore the sources for black carbon in the snow. The analysis found four factors or sources: two distinct biomass burning sources, a pollution source, and a marine source. The first three of these were responsible for essentially all of the black carbon, with the two biomass sources (encompassing both open and closed combustion) together accounting for >90% of the black carbon.

  2. Characterization of Black and Brown Carbon Concentrations and Sources during winter in Beijing

    Science.gov (United States)

    Yan, Caiqing; Liu, Yue; Hansen, Anthony D. A.; Močnik, Griša; Zheng, Mei

    2017-04-01

    Carbonaceous aerosols, including black carbon (BC) and organic carbon (OC), play important roles in air quality, human health, and climate change. A better understanding of sources of light-absorbing carbonaceous aerosol (including black carbon and brown carbon) is particular critical for formulating emission-based control strategies and reducing uncertainties in current aerosol radiative forcing estimates. Beijing, the capital of China, has experienced serious air pollution problems and high concentrations of carbonaceous aerosols in recent years, especially during heating seasons. During November and December of 2016, several severe haze episodes occurred in Beijing, with hourly average PM2.5 mass concentration up to 400 μg/m3. In this study, concentration levels and sources of black carbon and brown carbon were investigated based on 7-wavelength Aethalometer (AE-33) with combination of other PM2.5 chemical composition information. Contributions of traffic and non-traffic emissions (e.g., coal combustion, biomass burning) were apportioned, and brown carbon was separated from black carbon. Our preliminary results showed that (1) Concentrations of BC were around 5.3±4.2 μg/m3 during the study period, with distinct diurnal variations during haze and non-haze days. (2) Traffic emissions contributed to about 37±17% of total BC, and exhibited higher contributions during non-haze days compared to haze days. (3) Coal combustion was a major source of black carbon and brown carbon in Beijing, which was more significant compared to biomass burning. Sources and the relative contributions to black carbon and brown carbon during haze and non-haze days will be further discussed.

  3. Sources of uncertainties in modelling black carbon at the global scale

    NARCIS (Netherlands)

    Vignati, E.; Karl, M.; Krol, M.C.; Wilson, J.; Stier, P.; Cavalli, F.

    2010-01-01

    Our understanding of the global black carbon (BC) cycle is essentially qualitative due to uncertainties in our knowledge of its properties. This work investigates two source of uncertainties in modelling black carbon: those due to the use of different schemes for BC ageing and its removal rate in

  4. Sources of uncertainties in modelling black carbon at the global scale

    Directory of Open Access Journals (Sweden)

    E. Vignati

    2010-03-01

    Full Text Available Our understanding of the global black carbon (BC cycle is essentially qualitative due to uncertainties in our knowledge of its properties. This work investigates two source of uncertainties in modelling black carbon: those due to the use of different schemes for BC ageing and its removal rate in the global Transport-Chemistry model TM5 and those due to the uncertainties in the definition and quantification of the observations, which propagate through to both the emission inventories, and the measurements used for the model evaluation.

    The schemes for the atmospheric processing of black carbon that have been tested with the model are (i a simple approach considering BC as bulk aerosol and a simple treatment of the removal with fixed 70% of in-cloud black carbon concentrations scavenged by clouds and removed when rain is present and (ii a more complete description of microphysical ageing within an aerosol dynamics model, where removal is coupled to the microphysical properties of the aerosol, which results in a global average of 40% in-cloud black carbon that is scavenged in clouds and subsequently removed by rain, thus resulting in a longer atmospheric lifetime. This difference is reflected in comparisons between both sets of modelled results and the measurements. Close to the sources, both anthropogenic and vegetation fire source regions, the model results do not differ significantly, indicating that the emissions are the prevailing mechanism determining the concentrations and the choice of the aerosol scheme does not influence the levels. In more remote areas such as oceanic and polar regions the differences can be orders of magnitude, due to the differences between the two schemes. The more complete description reproduces the seasonal trend of the black carbon observations in those areas, although not always the magnitude of the signal, while the more simplified approach underestimates black carbon concentrations by orders of

  5. Graft-copolymerization onto carbon black

    International Nuclear Information System (INIS)

    Nakase, Yoshiaki; Nishii, Masanobu; Kijima, Toshiyuki; Kato, Hiroshi.

    1988-07-01

    Radiation-induced graft copolymerization of vinyl monomer onto carbon black was performed. During the γ-ray- and electron beam-induced polymerization (In-source), or the electron beam post-polymerization, the graft-copolymerization behavior was affected by the kinds of both carbon blacks and monomers, i.e. the smaller the size of carbon black particles, the higher the apparent grafted fraction. Homopolymer in the grafted carbon black samples was washed out by the solvent of the polymer, and the extracted polymer seemed to be dimer or trimer of the used monomer. In the case of the post-polymerization with the pre-irradiation doses of 50 Mrad, homopolymer was hardly observed. The polymer sheets of plastics or rubbers with grafted carbon black had an electrical conductivity unalterable considerably by the heating cycles. The particles of grafted carbon black in the sheet might be kept much more at the surface layer within 100 nm depth than at the inner layer. (author)

  6. Pyrolytic carbon black composite and method of making the same

    Energy Technology Data Exchange (ETDEWEB)

    Naskar, Amit K.; Paranthaman, Mariappan Parans; Bi, Zhonghe

    2016-09-13

    A method of recovering carbon black includes the step of providing a carbonaceous source material containing carbon black. The carbonaceous source material is contacted with a sulfonation bath to produce a sulfonated material. The sulfonated material is pyrolyzed to produce a carbon black containing product comprising a glassy carbon matrix phase having carbon black dispersed therein. A method of making a battery electrode is also disclosed.

  7. Barrow Black Carbon Source and Impact Study Final Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, Tate [Baylor Univ., Waco, TX (United States)

    2014-07-01

    The goal of the Barrow Black Carbon Source and Impact (BBCSI) Study was to characterize the concentration and isotopic composition of carbonaceous atmospheric particulate matter (PM) at the Atmospheric Radiation Measurement site in Barrow, AK. The carbonaceous component was characterized via measurement of the organic and black carbon (OC and BC) components of the total PM. To facilitate complete characterization of the particulate matter, filter-based collections were used, including a medium volume PM2.5 sampler and a high volume PM10 sampler. Thirty-eight fine (PM2.5) and 49 coarse (PM10) particulate matter fractions were collected at weekly and bi-monthly intervals. The PM2.5 sampler operated with minimal maintenance during the 12 month campaign. The PM10 sampler used for the BBCSI used standard Tisch hi-vol motors which have a known lifetime of ~1 month under constant use; this necessitated monthly maintenance and it is suggested that the motors be upgraded to industrial blowers for future deployment in the Arctic. The BBCSI sampling campaign successfully collected and archived 87 ambient atmospheric particulate matter samples from Barrow, AK from July 2012 to June 2013. Preliminary analysis of the organic and black carbon concentrations has been completed. This campaign confirmed known trends of high BC lasting from the winter through to spring haze periods and low BC concentrations in the summer.

  8. Barrow Black Carbon Source and Impact Study Final Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, Tate

    2014-07-01

    The goal of the Barrow Black Carbon Source and Impact campaign was to characterize the concentration and isotopic composition of carbonaceous atmospheric particulate matter (PM) at the Atmospheric Radiation Measurement (ARM) Climate Research Facility site in Barrow, Alaska. The carbonaceous component was characterized by measuring the organic and black carbon (OC and BC) components of the total PM. To facilitate complete characterization of the PM, filter-based collections were used, including a medium volume PM2.5 sampler and a high volume PM10 sampler. Thirty-eight fine PM fractions (PM2.5) and 49 coarse (PM10) PM fractions were collected at weekly and bi-monthly intervals. The PM2.5 sampler operated with minimal maintenance during the 12 month campaign. The PM10 sampler used for the Barrow Black Carbon Source and Impact (BBCSI) study used standard Tisch “hi-vol” motors that have a known lifetime of approximately 1 month under constant use; this necessitated monthly maintenance, and it is suggested that, for future deployment in the Arctic, the motors be upgraded to industrial blowers. The BBCSI sampling campaign successfully collected and archived 87 ambient atmospheric PM samples from Barrow, Alaska, from July 2012 to June 2013. Preliminary analysis of the OC and BC concentrations has been completed. This campaign confirmed known trends of high BC lasting from the winter through to spring haze periods and low BC concentrations in the summer. However, the annual OC concentrations had a very different seasonal pattern with the highest concentrations during the summer, lowest concentrations during the fall, and increased concentrations during the winter and spring (Figure 1).

  9. Russia's black carbon emissions: focus on diesel sources

    Directory of Open Access Journals (Sweden)

    N. Kholod

    2016-09-01

    Full Text Available Black carbon (BC is a significant climate forcer with a particularly pronounced forcing effect in polar regions such as the Russian Arctic. Diesel combustion is a major global source of BC emissions, accounting for 25–30 % of all BC emissions. While the demand for diesel is growing in Russia, the country's diesel emissions are poorly understood. This paper presents a detailed inventory of Russian BC emissions from diesel sources. Drawing on a complete Russian vehicle registry with detailed information about vehicle types and emission standards, this paper analyzes BC emissions from diesel on-road vehicles. We use the COPERT emission model (COmputer Programme to calculate Emissions from Road Transport with Russia-specific emission factors for all types of on-road vehicles. On-road diesel vehicles emitted 21 Gg of BC in 2014: heavy-duty trucks account for 60 % of the on-road BC emissions, while cars represent only 5 % (light commercial vehicles and buses account for the remainder. Using Russian activity data and fuel-based emission factors, the paper also presents BC emissions from diesel locomotives and ships, off-road engines in industry, construction and agriculture, and generators. The study also factors in the role of superemitters in BC emissions from diesel on-road vehicles and off-road sources. The total emissions from diesel sources in Russia are estimated to be 49 Gg of BC and 17 Gg of organic carbon (OC in 2014. Off-road diesel sources emitted 58 % of all diesel BC in Russia.

  10. Carbon black vs. black carbon and other airborne materials containing elemental carbon: Physical and chemical distinctions

    International Nuclear Information System (INIS)

    Long, Christopher M.; Nascarella, Marc A.; Valberg, Peter A.

    2013-01-01

    Airborne particles containing elemental carbon (EC) are currently at the forefront of scientific and regulatory scrutiny, including black carbon, carbon black, and engineered carbon-based nanomaterials, e.g., carbon nanotubes, fullerenes, and graphene. Scientists and regulators sometimes group these EC-containing particles together, for example, interchangeably using the terms carbon black and black carbon despite one being a manufactured product with well-controlled properties and the other being an undesired, incomplete-combustion byproduct with diverse properties. In this critical review, we synthesize information on the contrasting properties of EC-containing particles in order to highlight significant differences that can affect hazard potential. We demonstrate why carbon black should not be considered a model particle representative of either combustion soots or engineered carbon-based nanomaterials. Overall, scientific studies need to distinguish these highly different EC-containing particles with care and precision so as to forestall unwarranted extrapolation of properties, hazard potential, and study conclusions from one material to another. -- Highlights: •Major classes of elemental carbon-containing particles have distinct properties. •Despite similar names, carbon black should not be confused with black carbon. •Carbon black is distinguished by a high EC content and well-controlled properties. •Black carbon particles are characterized by their heterogenous properties. •Carbon black is not a model particle representative of engineered nanomaterials. -- This review demonstrates the significant physical and chemical distinctions between elemental carbon-containing particles e.g., carbon black, black carbon, and engineered nanomaterials

  11. An approach to a black carbon emission inventory for Mexico by two methods

    International Nuclear Information System (INIS)

    Cruz-Núñez, Xochitl

    2014-01-01

    A black carbon (BC) emission inventory for Mexico is presented. Estimate was performed by using two approaches, based on fuel consumption and emission factors in a top-down scheme, and the second from PM25 emission data and its correlation with black carbon by source category, assuming that black carbon = elemental carbon. Results show that black carbon emissions are in interval 53–473 Gg using the fuel consumption approach and between 62 and 89 using the sector method. Black carbon key sources come from biomass burning in the rural sector, with 47 percent share to the National total. Mobile sources emissions account to 16% to the total. An opportunity to reduce, in the short-term, carbon dioxide equivalent (CO2-eq) emissions by reducing black carbon emissions would be obtained in reducing emissions mainly from biomass burning in rural housing sector and diesel emissions in the transport sector with important co-benefits in direct radiative forcing, public health and air quality. - Highlights: • Black carbon emissions are estimated between 53 and 473 Gg/year on a fuel consumption method. • Black carbon emissions are estimated between 62 and 89 Gg/year on a sector method

  12. An approach to a black carbon emission inventory for Mexico by two methods

    Energy Technology Data Exchange (ETDEWEB)

    Cruz-Núñez, Xochitl, E-mail: xcruz@unam.mx

    2014-05-01

    A black carbon (BC) emission inventory for Mexico is presented. Estimate was performed by using two approaches, based on fuel consumption and emission factors in a top-down scheme, and the second from PM25 emission data and its correlation with black carbon by source category, assuming that black carbon = elemental carbon. Results show that black carbon emissions are in interval 53–473 Gg using the fuel consumption approach and between 62 and 89 using the sector method. Black carbon key sources come from biomass burning in the rural sector, with 47 percent share to the National total. Mobile sources emissions account to 16% to the total. An opportunity to reduce, in the short-term, carbon dioxide equivalent (CO2-eq) emissions by reducing black carbon emissions would be obtained in reducing emissions mainly from biomass burning in rural housing sector and diesel emissions in the transport sector with important co-benefits in direct radiative forcing, public health and air quality. - Highlights: • Black carbon emissions are estimated between 53 and 473 Gg/year on a fuel consumption method. • Black carbon emissions are estimated between 62 and 89 Gg/year on a sector method.

  13. BLACK Carbon Emissions from Diesel Sources in the Largest Arctic City: Case Study of Murmansk

    Science.gov (United States)

    Evans, M.; Kholod, N.; Malyshev, V.; Tretyakova, S.; Gusev, E.; Yu, S.; Barinov, A.

    2014-12-01

    Russia has very little data on its black carbon (BC) emissions. Because Russia makes up such a large share of the Arctic, understanding Russian emissions will improve our understanding of overall BC levels, BC in the Arctic and the link between BC and climate change. This paper provides a detailed, bottom-up inventory of BC emissions from diesel sources in Murmansk, Russia, along with uncertainty estimates associated with these emissions. The research team developed a detailed data collection methodology. The methodology involves assessing the vehicle fleet and activity in Murmansk using traffic, parking lot and driver surveys combined with an existing database from a vehicle inspection station and statistical data. The team also assessed the most appropriate emission factors, drawing from both Russian and international inventory methodologies. The researchers also compared fuel consumption using statistical data and bottom-up fuel calculations. They then calculated emissions for on-road transportation, off-road transportation (including mines), diesel generators, fishing and other sources. The article also provides a preliminary assessment of Russia-wide emissions of black carbon from diesel sources.

  14. Temporal and seasonal variations of black carbon in a highly polluted European city: Apportionment of potential sources and the effect of meteorological conditions.

    Science.gov (United States)

    Kucbel, Marek; Corsaro, Agnieszka; Švédová, Barbora; Raclavská, Helena; Raclavský, Konstantin; Juchelková, Dagmar

    2017-12-01

    Black carbon - a primary component of particulate matter emitted from an incomplete combustion of fossil fuels, biomass, and biofuels - has been found to have a detrimental effect on human health and the environment. Since black carbon emissions data are not readily available, no measures are implemented to reduce black carbon emissions. The temporal and seasonal variations of black carbon concentrations were evaluated during 2012-2014. The data were collected in the highly polluted European city - Ostrava, Czech Republic, surrounded by major highways and large industries. Significantly higher black carbon concentrations were obtained in Ostrava, relative to other European cities and the magnitude was equivalent to the magnitude of black carbon concentrations measured in Poland and China. The data were categorized to heating and non-heating seasons based on the periodic pattern of daily and monthly average concentrations of black carbon. A higher black carbon concentration was obtained during heating season than non-heating season and was primarily associated with an increase in residential coal burning and meteorological parameters. The concentration of black carbon was found to be negatively correlated with temperature and wind speed, and positively correlated with the relative humidity. Other black carbon sources potentially included emissions from vehicle exhaust and the local steel-producing industry. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Emissions & Measurements - Black Carbon | Science ...

    Science.gov (United States)

    Emissions and Measurement (EM) research activities performed within the National Risk Management Research Lab NRMRL) of EPA's Office of Research and Development (ORD) support measurement and laboratory analysis approaches to accurately characterize source emissions, and near source concentrations of air pollutants. They also support integrated Agency research programs (e.g., source to health outcomes) and the development of databases and inventories that assist Federal, state, and local air quality managers and industry implement and comply with air pollution standards. EM research underway in NRMRL supports the Agency's efforts to accurately characterize, analyze, measure and manage sources of air pollution. This pamphlet focuses on the EM research that NRMRL researchers conduct related to black carbon (BC). Black Carbon is a pollutant of concern to EPA due to its potential impact on human health and climate change. There are extensive uncertainties in emissions of BC from stationary and mobile sources. Emissions and Measurement (EM) research activities performed within the National Risk Management Research Lab NRMRL) of EPA's Office of Research and Development (ORD)

  16. Bounding the Role of Black Carbon in the Climate System: a Scientific Assessment

    Science.gov (United States)

    Bond, T. C.; Doherty, S. J.; Fahey, D. W.; Forster, P. M.; Bernsten, T.; DeAngelo, B. J.; Flanner, M. G.; Ghan, S.; Karcher, B.; Koch, D.; hide

    2013-01-01

    Black carbon aerosol plays a unique and important role in Earth's climate system. Black carbon is a type of carbonaceous material with a unique combination of physical properties. This assessment provides an evaluation of black-carbon climate forcing that is comprehensive in its inclusion of all known and relevant processes and that is quantitative in providing best estimates and uncertainties of the main forcing terms: direct solar absorption; influence on liquid, mixed phase, and ice clouds; and deposition on snow and ice. These effects are calculated with climate models, but when possible, they are evaluated with both microphysical measurements and field observations. Predominant sources are combustion related, namely, fossil fuels for transportation, solid fuels for industrial and residential uses, and open burning of biomass. Total global emissions of black carbon using bottom-up inventory methods are 7500 Gg/yr in the year 2000 with an uncertainty range of 2000 to 29000. However, global atmospheric absorption attributable to black carbon is too low in many models and should be increased by a factor of almost 3. After this scaling, the best estimate for the industrial-era (1750 to 2005) direct radiative forcing of atmospheric black carbon is +0.71 W/sq m with 90% uncertainty bounds of (+0.08, +1.27)W/sq m. Total direct forcing by all black carbon sources, without subtracting the preindustrial background, is estimated as +0.88 (+0.17, +1.48) W/sq m. Direct radiative forcing alone does not capture important rapid adjustment mechanisms. A framework is described and used for quantifying climate forcings, including rapid adjustments. The best estimate of industrial-era climate forcing of black carbon through all forcing mechanisms, including clouds and cryosphere forcing, is +1.1 W/sq m with 90% uncertainty bounds of +0.17 to +2.1 W/sq m. Thus, there is a very high probability that black carbon emissions, independent of co-emitted species, have a positive forcing

  17. Bounding the Role of Black Carbon in the Climate System: A Scientific Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Bond, Tami C.; Doherty, Sarah J.; Fahey, D. W.; Forster, Piers; Berntsen, T.; DeAngelo, B. J.; Flanner, M. G.; Ghan, Steven J.; Karcher, B.; Koch, Dorothy; Kinne, Stefan; Kondo, Yutaka; Quinn, P. K.; Sarofim, Marcus; Schultz, Martin; Schulz, M.; Venkataraman, C.; Zhang, Hua; Zhang, Shiqiu; Bellouin, N.; Guttikunda, S. K.; Hopke, P. K.; Jacobson, M. Z.; Kaiser, J. W.; Klimont, Z.; Lohmann, U.; Schwarz, Joshua P.; Shindell, Drew; Storelvmo, Trude; Warren, Stephen G.; Zender, C. S.

    2013-06-06

    Black carbon aerosol plays a unique and important role in Earth’s climate system. Black carbon is a type of carbonaceous material with a unique combination of physical properties. Predominant sources are combustion related; namely, fossil fuels for transportation, solid fuels for industrial and residential uses, and open burning of biomass. Total global emissions of black carbon using bottom-up inventory methods are 7500 Gg yr-1 in the year 2000 with an uncertainty range of 2000 to 29000. This assessment provides an evaluation of black-carbon climate forcing that is comprehensive in its inclusion of all known and relevant processes and that is quantitative in providing best estimates and uncertainties of the main forcing terms: direct solar absorption, influence on liquid, mixed-phase, and ice clouds, and deposition on snow and ice. These effects are calculated with models, but when possible, they are evaluated with both microphysical measurements and field observations. Global atmospheric absorption attributable to black carbon is too low in many models, and should be increased by about about 60%. After this scaling, the best estimate for the industrial-era (1750 to 2005) direct radiative forcing of black carbon is +0.43 W m-2 with 90% uncertainty bounds of (+0.17, +0.68) W m-2. Total direct forcing by all black carbon sources in the present day is estimated as +0.49 (+0.20, +0.76) W m-2. Direct radiative forcing alone does not capture important rapid adjustment mechanisms. A framework is described and used for quantifying climate forcings and their rapid responses and feedbacks. The best estimate of industrial-era (1750 to 2005) climate forcing of black carbon through all forcing mechanisms is +0.77 W m-2 with 90% uncertainty bounds of +-0.06 to +1.53 W m-2. Thus, there is a 96% probability that black carbon emissions, independent of co-emitted species, have a positive forcing and warm the climate. With a value of +0.77 W m-2, black carbon is likely the second

  18. Investigation of black and brown carbon multiple-wavelength-dependent light absorption from biomass and fossil fuel combustion source emissions

    Science.gov (United States)

    Michael R. Olson; Mercedes Victoria Garcia; Michael A. Robinson; Paul Van Rooy; Mark A. Dietenberger; Michael Bergin; James Jay Schauer

    2015-01-01

    Quantification of the black carbon (BC) and brown carbon (BrC) components of source emissions is critical to understanding the impact combustion aerosols have on atmospheric light absorption. Multiple-wavelength absorption was measured from fuels including wood, agricultural biomass, coals, plant matter, and petroleum distillates in controlled combustion settings....

  19. Biomass Burning Emissions of Black Carbon from African Sources

    Science.gov (United States)

    Aiken, A. C.; Leone, O.; Nitschke, K. L.; Dubey, M. K.; Carrico, C.; Springston, S. R.; Sedlacek, A. J., III; Watson, T. B.; Kuang, C.; Uin, J.; McMeeking, G. R.; DeMott, P. J.; Kreidenweis, S. M.; Robinson, A. L.; Yokelson, R. J.; Zuidema, P.

    2016-12-01

    Biomass burning (BB) emissions are a large source of carbon to the atmosphere via particles and gas phase species. Carbonaceous aerosols are emitted along with gas-phase carbon monoxide (CO) and carbon dioxide (CO2) that can be used to determine particulate emission ratios and modified combustion efficiencies. Black carbon (BC) aerosols are potentially underestimated in global models and are considered to be one of the most important global warming factors behind CO2. Half or more BC in the atmosphere is from BB, estimated at 6-9 Tg/yr (IPCC, 5AR) and contributing up to 0.6 W/m2 atmospheric warming (Bond et al., 2013). With a potential rise in drought and extreme events in the future due to climate change, these numbers are expected to increase. For this reason, we focus on BC and organic carbon aerosol species that are emitted from forest fires and compare their emission ratios, physical and optical properties to those from controlled laboratory studies of single-source BB fuels to understand BB carbonaceous aerosols in the atmosphere. We investigate BC in concentrated BB plumes as sampled from the new U.S. DOE ARM Program campaign, Layered Atlantic Smoke Interactions with Clouds (LASIC). The ARM Aerosol Mobile Facility 1 (AMF1) and Mobile Aerosol Observing System (MAOS) are currently located on Ascension Island in the South Atlantic Ocean, located midway between Angola and Brazil. The location was chosen for sampling maximum aerosol outflow from Africa. The far-field aged BC from LASIC is compared to BC from indoor generation from single-source fuels, e.g. African grass, sampled during Fire Lab At Missoula Experiments IV (FLAME-IV). BC is measured with a single-particle soot photometer (SP2) alongside numerous supporting instrumentation, e.g. particle counters, CO and CO2 detectors, aerosol scattering and absorption measurements, etc. FLAME-IV includes both direct emissions and well-mixed aerosol samples that have undergone dilution, cooling, and condensation. BC

  20. Chemically treated carbon black waste and its potential applications

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Pengwei; Maneerung, Thawatchai; Ng, Wei Cheng; Zhen, Xu [NUS Environmental Research Institute, National University of Singapore, 1 Create Way, Create Tower #15-02, 138602 (Singapore); Dai, Yanjun [School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Tong, Yen Wah [NUS Environmental Research Institute, National University of Singapore, 1 Create Way, Create Tower #15-02, 138602 (Singapore); Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 (Singapore); Ting, Yen-Peng [Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 (Singapore); Koh, Shin Nuo [Sembcorp Industries Ltd., 30 Hill Street #05-04, 179360 (Singapore); Wang, Chi-Hwa, E-mail: chewch@nus.edu.sg [Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 (Singapore); Neoh, Koon Gee, E-mail: chenkg@nus.edu.sg [Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 (Singapore)

    2017-01-05

    Highlights: • Hazardous impurities separated from carbon black waste with little damage to solid. • Heavy metals were effectively removed from carbon black waste by HNO{sub 3} leaching. • Treated carbon black waste has high adsorption capacity (∼356.4 mg{sub dye}/g). • Carbon black waste was also found to show high electrical conductivity (10 S/cm). - Abstract: In this work, carbon black waste – a hazardous solid residue generated from gasification of crude oil bottom in refineries – was successfully used for making an absorbent material. However, since the carbon black waste also contains significant amounts of heavy metals (especially nickel and vanadium), chemical leaching was first used to remove these hazardous impurities from the carbon black waste. Acid leaching with nitric acid was found to be a very effective method for removal of both nickel and vanadium from the carbon black waste (i.e. up to 95% nickel and 98% vanadium were removed via treatment with 2 M nitric acid for 1 h at 20 °C), whereas alkali leaching by using NaOH under the same condition was not effective for removal of nickel (less than 10% nickel was removed). Human lung cells (MRC-5) were then used to investigate the toxicity of the carbon black waste before and after leaching. Cell viability analysis showed that the leachate from the original carbon black waste has very high toxicity, whereas the leachate from the treated samples has no significant toxicity. Finally, the efficacy of the carbon black waste treated with HNO{sub 3} as an absorbent for dye removal was investigated. This treated carbon black waste has high adsorption capacity (∼361.2 mg {sub dye}/g {sub carbonblack}), which can be attributed to its high specific surface area (∼559 m{sup 2}/g). The treated carbon black waste with its high adsorption capacity and lack of cytotoxicity is a promising adsorbent material. Moreover, the carbon black waste was found to show high electrical conductivity (ca. 10 S

  1. Characterizing and sourcing ambient PM2.5 over key emission regions in China III: Carbon isotope based source apportionment of black carbon

    Science.gov (United States)

    Yu, Kuangyou; Xing, Zhenyu; Huang, Xiaofeng; Deng, Junjun; Andersson, August; Fang, Wenzheng; Gustafsson, Örjan; Zhou, Jiabin; Du, Ke

    2018-03-01

    Regional haze over China has severe implications for air quality and regional climate. To effectively combat these effects the high uncertainties regarding the emissions from different sources needs to be reduced. In this paper, which is the third in a series on the sources of PM2.5 in pollution hotspot regions of China, we focus on the sources of black carbon aerosols (BC), using carbon isotope signatures. Four-season samples were collected at two key locations: Beijing-Tianjin-Hebei (BTH, part of Northern China plain), and the Pearl River Delta (PRD). We find that that fossil fuel combustion was the predominant source of BC in both BTH and PRD regions, accounting for 75 ± 5%. However, the contributions of what fossil fuel components were dominating differed significantly between BTH and PRD, and varied dramatically with seasons. Coal combustion is overall the all-important BC source in BTH, accounting for 46 ± 12% of the BC in BTH, with the maximum value (62%) found in winter. In contrast for the PRD region, liquid fossil fuel combustion (e.g., oil, diesel, and gasoline) is the dominant source of BC, with an annual mean value of 41 ± 15% and the maximum value of 55% found in winter. Region- and season-specific source apportionments are recommended to both accurately assess the climate impact of carbonaceous aerosol emissions and to effectively mitigate deteriorating air quality caused by carbonaceous aerosols.

  2. Source contributions to atmospheric fine carbon particle concentrations

    Science.gov (United States)

    Andrew Gray, H.; Cass, Glen R.

    A Lagrangian particle-in-cell air quality model has been developed that facilitates the study of source contributions to atmospheric fine elemental carbon and fine primary total carbon particle concentrations. Model performance was tested using spatially and temporally resolved emissions and air quality data gathered for this purpose in the Los Angeles area for the year 1982. It was shown that black elemental carbon (EC) particle concentrations in that city were dominated by emissions from diesel engines including both on-highway and off-highway applications. Fine primary total carbon particle concentrations (TC=EC+organic carbon) resulted from the accumulation of small increments from a great variety of emission source types including both gasoline and diesel powered highway vehicles, stationary source fuel oil and gas combustion, industrial processes, paved road dust, fireplaces, cigarettes and food cooking (e.g. charbroilers). Strategies for black elemental carbon particle concentration control will of necessity need to focus on diesel engines, while controls directed at total carbon particle concentrations will have to be diversified over a great many source types.

  3. Impacts of black carbon and co-pollutant emissions from transportation sector in Mexico City

    Science.gov (United States)

    Zavala, Miguel; Almanza, Victor; Garcia, Agustin; Jazcilevich, Aron; Lei, Wenfang; Molina, Luisa

    2016-04-01

    Black carbon is one of the most important short-lived climate-forcing agents, which is harmful to human health and also contributes significantly to climate change. Transportation is one of the largest sources of black carbon emissions in many megacities and urban complexes, with diesel vehicles leading the way. Both on-road and off-road vehicles can emit substantial amounts of harmful BC-containing particulate matter (PM) and are also responsible for large emissions of carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx), and many other co-emitted volatile organic compounds (VOCs). Regionally, black carbon emissions contributions from mobile sources may vary widely depending on the technical characteristics of the vehicle fleet, the quality and chemical properties of the fuels consumed, and the degree of local development and economic activities that foster wider and more frequent or intensive use of vehicles. This presentation will review and assess the emissions of black carbon from the on-road and off-road transportation sector in the Mexico City Metropolitan Area. Viable mitigation strategies, including innovative technological alternatives to reduce black carbon and co-pollutants in diesel vehicles and their impacts on climate, human health and ecosystems will be described.

  4. Comparative DEMS study on the electrochemical oxidation of carbon blacks

    DEFF Research Database (Denmark)

    Ashton, Sean James; Arenz, Matthias

    2012-01-01

    Publication year: 2012 Source:Journal of Power Sources, Volume 217 Sean J. Ashton, Matthias Arenz The intention of the study presented here is to compare the electrochemical oxidation tendencies of a pristine Ketjen Black EC300 high surface area (HSA) carbon black, and four graphitised counterparts...... heat-treated between 2100 and 3200 °C, such as those typically used as corrosion resistant carbon (CRC) supports for polymer electrolyte membrane fuel cell (PEMFC) catalysts. A methodology combining cyclic voltammetry (CV) and differential electrochemical mass spectrometry (DEMS) is used, which allows......; however, CRC samples graphitised =2800 °C did not exhibit this same behaviour. Highlights ¿ We quantitatively determine electrooxidation of carbon support materials. ¿ We can distinguish between the total and partial electrooxidation. ¿ Non or mildly heat treated carbon forms passivating layer. ¿ Heat...

  5. Black carbon network in Mexico. First Results

    Science.gov (United States)

    Barrera, Valter; Peralta, Oscar; Granado, Karen; Ortinez, Abraham; Alvarez-Ospina, Harry; Espinoza, Maria de la Luz; Castro, Telma

    2017-04-01

    After the United Nations Framework Convention on Climate Change celebrated in Paris 2016, many countries should adopt some mechanisms in the next years to contribute to mitigate greenhouse gas emissions and support sustainable development. Mexico Government has adopted an unconditional international commitment to carry out mitigation actions that would result in the reduction of 51% in black carbon (BC) emissions by year 2030. However, many BC emissions have been calculated by factor emissions. Since optical measurements of environmental BC concentrations can vary according the different components and their subsequence wavelength measure, it's important to obtain more accurate values. BC is formally defined as an ideally light-absorbing substance composed by carbon (Bond et al., 2013), and is the second main contributor (behind Carbon Dioxide; CO2) to positive radiative forcing (Ramanathan and Carmichael, 2008). Recently, BC has been used as an additional indicator in air quality management in some cities because is emitted from the incomplete combustion of fossil fuels, biofuel and biomass burning in both anthropogenic and it is always emitted with other particles and gases, such as organic carbon (OC), nitrogen oxides (NOx), and sulfur dioxide (SO2). Black Carbon, PM2.5 and pollutant gases were measured from January 2015 to December 2015 at three main cities in Mexico, and two other places to evaluate the BC concentration levels in the country. The urban background sites (Mexico City, Monterrey, Guadalajara, MXC-UB, GDL-UB, MTY-UB), a sub-urban background site (Juriquilla, Queretaro, JUR-SUB) and a regional background site (Altzomoni, ALT-RB). Results showed the relationship between BC and PM2.5 in the 3 large cities, with BC/PM2.5 ratios near 0.14 to 0.09 and a high BC-CO relationship in all the year in Mexico City, who showed that mobile sources are a common, at least in cities with a non-significant biomass burning emission related to agriculture or coal

  6. 129 Xe-NMR of carbon black filled elastomers

    International Nuclear Information System (INIS)

    Sperling-Ischinsky, K.; Veeman, W.S.

    1999-01-01

    It is shown that 129 Xe-NMR is a powerful tool to investigate carbon black and carbon black filled elastomers. For the carbon black material itself the 129 Xe chemical shift of xenon adsorbed at the surface of carbon black aggregates yields information about the relative average pore size of the carbon black aggregates. The experimental 129 Xe-NMR results of carbon black filled ethylene-propylene-diene (EPDM) can be explained when it is assumed that the xenon atoms in the bound EPDM fraction exchange rapidly on the NMR time scale between a state where they are adsorbed on the carbon black surface and a state in which they are absorbed in the EPDM layer. This would imply that the carbon black aggregates are not completely covered with EPDM chains. (author)

  7. Local and remote black carbon sources in the Metropolitan Area of Buenos Aires

    Science.gov (United States)

    Diaz Resquin, Melisa; Santágata, Daniela; Gallardo, Laura; Gómez, Darío; Rössler, Cristina; Dawidowski, Laura

    2018-06-01

    Equivalent black carbon (EBC) mass concentrations in the fine inhalable fraction of airborne particles (PM2.5) were determined using a 7-wavelength Aethalometer for 17 months, between November 2014 and March 2016, for a suburban location of the Metropolitan Area of Buenos Aires (MABA), Argentina. In addition to describing seasonal and diurnal black carbon (BC) cycles for the first time in this region, the relative contributions of fossil fuel and remote and local biomass burning were determined by distinguishing different carbonaceous components based on their effect on light attenuation for different wavelengths. Trajectory analyses and satellite-based fire products were used to illustrate the impact of long-range transport of particles emitted by non-local sources. EBC data showed a marked diurnal cycle, largely modulated by traffic variations and the height of the boundary layer, and a seasonal cycle with monthly median EBC concentrations (in μg /m3) ranging from 1.5 (February) to 3.4 (June). Maximum values were found during winter due to the combination of prevailingly stable atmospheric conditions and the increase of fossil fuel emissions, derived primarily from traffic and biomass burning from the domestic use of wood for heating. The use of charcoal grills was also detected and concentrated during weekends. The average contribution of fossil fuel combustion sources to EBC concentrations was 96%, with the remaining 4% corresponding to local and regional biomass burning. During the entire study period, only two events were identified during which EBC concentrations attributed to regional biomass burning accounted for over 50% of total EBC ; these events demonstrate the relevance of agricultural and forestry activities that take place far from the city yet whose emissions can affect the urban atmosphere of the MABA.

  8. Black carbon and mineral dust in snow cover on the Tibetan Plateau

    Science.gov (United States)

    Zhang, Yulan; Kang, Shichang; Sprenger, Michael; Cong, Zhiyuan; Gao, Tanguang; Li, Chaoliu; Tao, Shu; Li, Xiaofei; Zhong, Xinyue; Xu, Min; Meng, Wenjun; Neupane, Bigyan; Qin, Xiang; Sillanpää, Mika

    2018-02-01

    Snow cover plays a key role for sustaining ecology and society in mountainous regions. Light-absorbing particulates (including black carbon, organic carbon, and mineral dust) deposited on snow can reduce surface albedo and contribute to the near-worldwide melting of snow and ice. This study focused on understanding the role of black carbon and other water-insoluble light-absorbing particulates in the snow cover of the Tibetan Plateau (TP). The results found that the black carbon, organic carbon, and dust concentrations in snow cover generally ranged from 202 to 17 468 ng g-1, 491 to 13 880 ng g-1, and 22 to 846 µg g-1, respectively, with higher concentrations in the central to northern areas of the TP. Back trajectory analysis suggested that the northern TP was influenced mainly by air masses from Central Asia with some Eurasian influence, and air masses in the central and Himalayan region originated mainly from Central and South Asia. The relative biomass-burning-sourced black carbon contributions decreased from ˜ 50 % in the southern TP to ˜ 30 % in the northern TP. The relative contribution of black carbon and dust to snow albedo reduction reached approximately 37 and 15 %, respectively. The effect of black carbon and dust reduced the snow cover duration by 3.1 ± 0.1 to 4.4 ± 0.2 days. Meanwhile, the black carbon and dust had important implications for snowmelt water loss over the TP. The findings indicate that the impacts of black carbon and mineral dust need to be properly accounted for in future regional climate projections, particularly in the high-altitude cryosphere.

  9. Long-term trends in California mobile source emissions and ambient concentrations of black carbon and organic aerosol.

    Science.gov (United States)

    McDonald, Brian C; Goldstein, Allen H; Harley, Robert A

    2015-04-21

    A fuel-based approach is used to assess long-term trends (1970-2010) in mobile source emissions of black carbon (BC) and organic aerosol (OA, including both primary emissions and secondary formation). The main focus of this analysis is the Los Angeles Basin, where a long record of measurements is available to infer trends in ambient concentrations of BC and organic carbon (OC), with OC used here as a proxy for OA. Mobile source emissions and ambient concentrations have decreased similarly, reflecting the importance of on- and off-road engines as sources of BC and OA in urban areas. In 1970, the on-road sector accounted for ∼90% of total mobile source emissions of BC and OA (primary + secondary). Over time, as on-road engine emissions have been controlled, the relative importance of off-road sources has grown. By 2010, off-road engines were estimated to account for 37 ± 20% and 45 ± 16% of total mobile source contributions to BC and OA, respectively, in the Los Angeles area. This study highlights both the success of efforts to control on-road emission sources, and the importance of considering off-road engine and other VOC source contributions when assessing long-term emission and ambient air quality trends.

  10. Immersion microcalorimetry of a carbon black

    International Nuclear Information System (INIS)

    Mendelbaum, Georges

    1966-01-01

    This research thesis first reports a detailed bibliographical study on various topics (fabrication of carbon black, oxidation, immersion heat, adsorptions, main existing theories, and thermodynamics) and then the development of immersion and adsorption microcalorimetry apparatuses aimed at studying the surface of a carbon black and the influence of the oxidation of this carbon black on the adsorption of polar and non-polar solvents. Immersion heats of a raw or oxidised carbon black have been measured in water, in cyclohexane and in methanol. The adsorption of methanol at 20 C and that of nitrogen at -196 C have also been measured. The author outlines that degassing conditions had to be taken into account before performing measurements [fr

  11. Sources and burial fluxes of soot black carbon in sediments on the Mackenzie, Chukchi, and Bering Shelves

    Science.gov (United States)

    Yang, Weifeng; Guo, Laodong

    2018-03-01

    Black carbon (BC) has been recognized as a climate forcing and a major component in the global carbon budget. However, studies on BC in the Arctic Ocean remain scarce. We report here variations in the abundance, sources and burial fluxes of sedimentary soot black carbon (soot-BC) in the western Arctic Ocean. The soot-BC contents averaged 1.6 ± 0.3, 0.46 ± 0.04 and 0.56 ± 0.10 mg-C g-1 on the Mackenzie, Chukchi and Bering Shelves, respectively, accounting for 16.6%, 10.2% and 10.4% of the total organic carbon in surface sediment. Temporally, contents of soot-BC remained fairly stable before 1910, but increased rapidly after the 1970s on the Mackenzie Shelf, indicating enhanced source input related to warming. Comparable δ13C signatures of soot-BC (- 24.95‰ to - 24.57‰) to C3 plants pointed to a major biomass source of soot-BC to the Beaufort Sea. Soot-BC showed similar temporal patterns with large fluctuations in the Chukchi/Bering shelf regions, implying the same source terms for soot-BC in these areas. Two events with elevated soot-BC corresponded to a simultaneous increase in biomass combustion and fossil fuel (coal and oil) consumption in Asia. The similar temporal variability in sedimentary soot-BC between the Arctic shelves and Asian lakes and the comparable δ13C values manifested that anthropogenic emission from East Asia was an important source of soot-BC in the western Arctic and subarctic regions. The burial fluxes of soot-BC, estimated from both 137Cs- and 210Pb-derived sedimentation rates, were 2.43 ± 0.42 g-C m-2 yr-1 on the Mackenzie Shelf, representing an efficient soot-BC sink. Soot-BC showed an increase in buried fluxes from 0.56 ± 0.02 g-C m-2 yr-1 during 1963-1986 to 0.88 ± 0.05 g-C m-2 yr-1 after 1986 on the Chukchi Shelf, and from 1.00 ± 0.18 g-C m-2 yr-1 to 2.58 ± 1.70 g-C m-2 yr-1 on the Bering Shelf, which were consistent with recent anthropogenically enhanced BC input observed especially in Asia. Overall, the three Arctic

  12. Synthesis and luminescence of nanodiamonds from carbon black

    International Nuclear Information System (INIS)

    Hu Shengliang; Tian Fei; Bai Peikang; Cao Shirui; Sun Jing; Yang Jing

    2009-01-01

    Dispersed nanodiamonds just several nanometers in diameter have been successfully synthesized using carbon black as the carbon source by a long-pulse-width laser irradiation in water at room temperature and normal pressure. The produced nanodiamonds can emit strong visible light after simple surface passivation. The light emission is attributed to the surface states related to linkage groups formed on nanodiamond surface. The surface-passivated nanodiamonds with stable photoluminescence have high potential application in bioimaging and medicine

  13. Modified carbon black materials for lithium-ion batteries

    Science.gov (United States)

    Kostecki, Robert; Richardson, Thomas; Boesenberg, Ulrike; Pollak, Elad; Lux, Simon

    2016-06-14

    A lithium (Li) ion battery comprising a cathode, a separator, an organic electrolyte, an anode, and a carbon black conductive additive, wherein the carbon black has been heated treated in a CO.sub.2 gas environment at a temperature range of between 875-925 degrees Celsius for a time range of between 50 to 70 minutes to oxidize the carbon black and reduce an electrochemical reactivity of the carbon black towards the organic electrolyte.

  14. Relationships between organic matter, black carbon and persistent organic pollutants in European background soils: Implications for sources and environmental fate

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Jae Jak [Centre for Chemicals Management and Environmental Science Department, Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom); National Institute of Agricultural Science and Technology, RDA, 249 Sedun, Suwon 702-701 (Korea, Republic of); Gustafsson, Orjan [Department of Applied Environmental Science (ITM), Stockholm University, 10691 Stockholm (Sweden); Kurt-Karakus, Perihan [Centre for Chemicals Management and Environmental Science Department, Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Breivik, Knut [Norwegian Institute for Air Research, P.O. Box 100, NO-2027 Kjeller (Norway); University of Oslo, Department of Chemistry, P.O. Box 1033, NO-0315 Oslo (Norway); Steinnes, Eiliv [Department of Chemistry, Norwegian University of Science and Technology, NO-7491 Trondheim (Norway); Jones, Kevin C. [Centre for Chemicals Management and Environmental Science Department, Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom)], E-mail: k.c.jones@lancaster.ac.uk

    2008-12-15

    Black carbon (BC) and total organic carbon (TOC) contents of UK and Norwegian background soils were determined and their relationships with persistent organic pollutants (HCB, PAHs, PCBs, co-planar PCBs, PBDEs and PCDD/Fs) investigated by correlation and regression analyses, to assess their roles in influencing compound partitioning/retention in soils. The 52 soils used were high in TOC (range 54-460 mg/g (mean 256)), while BC only constituted 0.24-1.8% (0.88%) of the TOC. TOC was strongly correlated (p < 0.001) with HCB, PCBs, co-PCBs and PBDEs, but less so with PCDD/Fs (p < 0.05) and PAHs. TOC explained variability in soil content, as follows: HCB, 80%; PCBs, 44%; co-PCBs, 40%; PBDEs, 27%. BC also gave statistically significant correlations with PBDEs (p < 0.001), co-PCBs (p < 0.01) and PCBs, HCB, PCDD/F (p < 0.05); TOC and BC were correlated with each other (p < 0.01). Inferences are made about possible combustion-derived sources, atmospheric transport and air-surface exchange processes for these compounds. - Total organic carbon and black carbon fractions can play an important role in the storage and cycling of persistent organic pollutants in background soils.

  15. Relationships between organic matter, black carbon and persistent organic pollutants in European background soils: Implications for sources and environmental fate

    International Nuclear Information System (INIS)

    Nam, Jae Jak; Gustafsson, Orjan; Kurt-Karakus, Perihan; Breivik, Knut; Steinnes, Eiliv; Jones, Kevin C.

    2008-01-01

    Black carbon (BC) and total organic carbon (TOC) contents of UK and Norwegian background soils were determined and their relationships with persistent organic pollutants (HCB, PAHs, PCBs, co-planar PCBs, PBDEs and PCDD/Fs) investigated by correlation and regression analyses, to assess their roles in influencing compound partitioning/retention in soils. The 52 soils used were high in TOC (range 54-460 mg/g (mean 256)), while BC only constituted 0.24-1.8% (0.88%) of the TOC. TOC was strongly correlated (p < 0.001) with HCB, PCBs, co-PCBs and PBDEs, but less so with PCDD/Fs (p < 0.05) and PAHs. TOC explained variability in soil content, as follows: HCB, 80%; PCBs, 44%; co-PCBs, 40%; PBDEs, 27%. BC also gave statistically significant correlations with PBDEs (p < 0.001), co-PCBs (p < 0.01) and PCBs, HCB, PCDD/F (p < 0.05); TOC and BC were correlated with each other (p < 0.01). Inferences are made about possible combustion-derived sources, atmospheric transport and air-surface exchange processes for these compounds. - Total organic carbon and black carbon fractions can play an important role in the storage and cycling of persistent organic pollutants in background soils

  16. Structure and properties of carbon black particles

    Science.gov (United States)

    Xu, Wei

    Structure and properties of carbon black particles were investigated using atomic force microscopy, gas adsorption, Raman spectroscopy, and X-ray diffraction. Supplementary information was obtained using TEM and neutron scattering. The AFM imaging of carbon black aggregates provided qualitative visual information on their morphology, complementary to that obtained by 3-D modeling based on TEM images. Our studies showed that carbon black aggregates were relatively flat. The surface of all untreated carbon black particles was found to be rough and its fractal dimension was 2.2. Heating reduced the roughness and fractal dimension for all samples heat treated at above 1300 K to 2.0. Once the samples were heat treated rapid cooling did not affect the surface roughness. However, rapid cooling reduced crystallite sizes, and different Raman spectra were obtained for carbon blacks of various history of heat treatment. By analyzing the Raman spectra we determined the crystallite sizes and identified amorphous carbon. The concentration of amorphous carbon depends on hydrogen content. Once hydrogen was liberated at increased temperature, the concentration of amorphous carbon was reduced and crystallites started to grow. Properties of carbon blacks at high pressure were also studied. Hydrostatic pressure did not affect the size of the crystallites in carbon black particles. The pressure induced shift in Raman frequency of the graphitic component was a result of increased intermolecular forces and not smaller crystallites. Two methods of determining the fractal dimension, the FHH model and the yardstick technique based on the BET theory were used in the literature. Our study proved that the FHH model is sensitive to numerous assumptions and leads to wrong conclusions. On the other hand the yardstick method gave correct results, which agreed with the AFM results.

  17. Black carbon: The reverse of its dark side

    NARCIS (Netherlands)

    Koelmans, A.A.; Jonker, M.T.O.; Cornelissen, G.; Bucheli, T.D.; Noort, van P.C.M.; Gustafsson, O.

    2006-01-01

    The emission of black carbon is known to cause major environmental problems. Black carbon particles contribute to global warming, carry carcinogenic compounds and cause serious health risks. Here, we show another side of the coin. We review evidence that black carbon may strongly reduce the risk

  18. Characterization of Black Carbon Mixing State Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Sedlacek, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Davidovits, P. [Boston College, Chestnut Hill, MA (United States); Lewis, E. R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Onasch, T. B. [Aerodyne Research, Billerica, MA (United States)

    2016-04-01

    Interpreting the temporal relationship between the scattering and incandescence signals recorded by the Single Particle Soot Photometer (SP2), Sedlacek et al. (2012) reported that 60% of the refractory black carbon containing particles in a plume containing biomass burning tracers exhibited non-core-shell structure. Because the relationship between the rBC (refractory black carbon) incandescence and the scattering signals had not been reported in the peer-reviewed literature, and to further evaluate the initial interpretation by Sedlacek et al., a series of experiments was undertaken to investigate black carbon-containing particles of known morphology using Regal black (RB), a proxy for collapsed soot, as the light-absorbing substance to characterize this signal relationship. Particles were formed by coagulation of RB with either a solid substance (sodium chloride or ammonium sulfate) or a liquid substance (dioctyl sebacate), and by condensation with dioctyl sebacate, the latter experiment forming particles in a core-shell configuration. Each particle type experienced fragmentation (observed as negative lagtimes), and each yielded similar lagtime responses in some instances, confounding attempts to differentiate particle morphology using current SP2 lagtime analysis. SP2 operating conditions, specifically laser power and sample flow rate, which in turn affect the particle heating and dissipation rates, play an important role in the behavior of particles in the SP2, including probability of fragmentation. This behavior also depended on the morphology of the particles and on the thermochemical properties of the non-RB substance. Although these influences cannot currently be unambiguously separated, the SP2 analysis may still provide useful information on particle mixing states and black carbon particle sources. This work was communicated in a 2015 publication (Sedlacek et al. 2015)

  19. A study of the mixing state of black carbon in urban zone

    Science.gov (United States)

    Mallet, M.; Roger, J. C.; Despiau, S.; Putaud, J. P.; Dubovik, O.

    2004-02-01

    The knowledge of the mixing state of black carbon particle with other aerosol species is critical for adequate simulations of the direct radiative effect of black carbon particles and its effect on climate. This paper reports the investigation of the mixing state of black carbon aerosol in the urban zone. The study uses a combination of in situ and ground-based remote sensing observations conducted during the ESCOMPTE experiment, which took place in industrialized region in France in summer of 2001. The criteria we used for identifying mixing state relies on the known enhancement of absorption for aerosol composed by internal versus external mixtures of black carbon with weakly absorbing aerosol components. First, using in situ aerosol data, we performed Mie computations and reconstructed the single scattering albedo of aerosol for the two different mixing assumptions: black carbon mixed externally or internally with other aerosol species. Then, we compared the obtained values ωo,int and ωo,ext with the retrievals of ωo from independent AERONET Sun-photometric measurements. The aerosol single scattering albedo (ωo,aer.) derived from the AERONET photometer observations (with the mean value equal to 0.84 ± 0.04) was found to be close to ωo,ext reconstructed from in situ observation under assumptions of external mixture. This similarity between AERONET values and external mixture simulations was observed during all the days studied. Our conclusion on external mixture of black carbon aerosol with other particles in urban zone during ESCOMPTE (close to the pollution source) is coherent with observations made during other independent studies reported in a number of recent publications.

  20. Sources and transport of black carbon at the California-Mexico border

    Science.gov (United States)

    Shores, Christopher A.; Klapmeyer, Michael E.; Quadros, Marina E.; Marr, Linsey C.

    2013-05-01

    At international border areas that suffer from poor air quality, assessment of pollutant sources and transport across the border is important for designing effective air quality management strategies. As part of the Cal-Mex 2010 field campaign at the US-Mexico border in San Diego and Tijuana, we measured black carbon (BC) concentrations at three locations in Mexico and one in the United States. The measurements were intended to support the following objectives: to characterize the spatial and temporal variability in BC, to estimate the BC emission inventory, to identify potential source areas of BC emissions, and to assess the cross-border transport of BC. Concentrations at Parque Morelos, the campaign's supersite, averaged 2.2 μg m-3 and reached a maximum value of 55.9 μg m-3 (1-min average). Sharp, regularly occurring peaks around midnight were suggestive of clandestine industrial activity. BC concentrations were more than two times higher, on average, in Tijuana compared to San Diego. BC and carbon monoxide (CO) were strongly correlated at the three sites in Mexico. The ΔBC/ΔCO ratio of 5.6 ± 0.5 μg m-3 ppm-1 in Tijuana, or 4.7 ± 0.5 μg m-3 ppm-1 when adjusted for seasonal temperature effects to represent an annual average, was comparable to that in other urban areas. Tijuana's emissions of BC were estimated to be 230-890 metric tons per year, 6-23% of those estimated for San Diego. Large uncertainties in this estimate stem mainly from uncertainties in the CO emission inventory, and the lower end of the estimate is more likely to be accurate. Patterns in concentrations and winds suggest that BC in Tijuana was usually of local origin. Under typical summertime conditions such as those observed during the study, transport from Tijuana into the US was common, crossing the border in a northeasterly direction, sometimes as far east as Imperial County at the eastern edge of California.

  1. Estimation of black carbon content for biomass burning aerosols from multi-channel Raman lidar data

    Science.gov (United States)

    Talianu, Camelia; Marmureanu, Luminita; Nicolae, Doina

    2015-04-01

    Biomass burning due to natural processes (forest fires) or anthropical activities (agriculture, thermal power stations, domestic heating) is an important source of aerosols with a high content of carbon components (black carbon and organic carbon). Multi-channel Raman lidars provide information on the spectral dependence of the backscatter and extinction coefficients, embedding information on the black carbon content. Aerosols with a high content of black carbon have large extinction coefficients and small backscatter coefficients (strong absorption), while aerosols with high content of organic carbon have large backscatter coefficients (weak absorption). This paper presents a method based on radiative calculations to estimate the black carbon content of biomass burning aerosols from 3b+2a+1d lidar signals. Data is collected at Magurele, Romania, at the cross-road of air masses coming from Ukraine, Russia and Greece, where burning events are frequent during both cold and hot seasons. Aerosols are transported in the free troposphere, generally in the 2-4 km altitude range, and reaches the lidar location after 2-3 days. Optical data are collected between 2011-2012 by a multi-channel Raman lidar and follows the quality assurance program of EARLINET. Radiative calculations are made with libRadTran, an open source radiative model developed by ESA. Validation of the retrievals is made by comparison to a co-located C-ToF Aerosol Mass Spectrometer. Keywords: Lidar, aerosols, biomass burning, radiative model, black carbon Acknowledgment: This work has been supported by grants of the Romanian National Authority for Scientific Research, Programme for Research- Space Technology and Advanced Research - STAR, project no. 39/2012 - SIAFIM, and by Romanian Partnerships in priority areas PNII implemented with MEN-UEFISCDI support, project no. 309/2014 - MOBBE

  2. Source attribution of black carbon and its direct radiative forcing in China

    International Nuclear Information System (INIS)

    Yang, Yang; Wang, Hailong; Ma, Po-Lun; Rasch, Philip J.; Smith, Steven J.

    2017-01-01

    The source attributions for mass concentration, haze formation, transport and direct radiative forcing of black carbon (BC) in various regions of China are quantified in this study using the Community Earth System Model (CESM) with a source-tagging technique. Anthropogenic emissions are from the Community Emissions Data System that is newly developed for the Coupled Model Intercomparison Project Phase 6 (CMIP6). Over north China where the air quality is often poor, about 90 % of near-surface BC concentration is contributed by local emissions. Overall, 35 % of BC concentration over south China in winter can be attributed to emissions from north China, and 19 % comes from sources outside China in spring. For other regions in China, BC is largely contributed from nonlocal sources. We further investigated potential factors that contribute to the poor air quality in China. During polluted days, a net inflow of BC transported from nonlocal source regions associated with anomalous winds plays an important role in increasing local BC concentrations. BC-containing particles emitted from East Asia can also be transported across the Pacific. Our model results show that emissions from inside and outside China are equally important for the BC outflow from East Asia, while emissions from China account for 8 % of BC concentration and 29 % in column burden in the western United States in spring. Radiative forcing estimates show that 65 % of the annual mean BC direct radiative forcing (2.2 W m -2 ) in China results from local emissions, and the remaining 35 % is contributed by emissions outside of China. Efficiency analysis shows that a reduction in BC emissions over eastern China could have a greater benefit for the regional air quality in China, especially in the winter haze season.

  3. Continental scale Antarctic deposition of sulphur and black carbon from anthropogenic and volcanic sources

    Directory of Open Access Journals (Sweden)

    H.-F. Graf

    2010-03-01

    Full Text Available While Antarctica is often described as a pristine environment, there is an increasing awareness of the potential threats from local pollution sources including tourist ships and emissions associated with scientific activities. However, to date there has been no systematic attempt to model the impacts of such pollutants at the continental scale. Indeed, until very recently there was not even a sulphur emission budget available for Antarctica. Here we present the first comprehensive study of atmospheric pollution in Antarctica using a limited area chemistry climate model, and a monthly emissions inventory for sulphur from maintenance of research stations, ground and air traffic, shipping and the active Erebus volcano. We find that ship emissions, both sulphurous and black carbon, dominate anthropogenic pollution near the ground. Their prevalence is likely to rise dramatically if recent trends in tourism continue.

  4. Black Ink of Activated Carbon Derived From Palm Kernel Cake (PKC)

    Science.gov (United States)

    Selamat, M. H.; Ahmad, A. H.

    2009-06-01

    Recycling the waste from natural plant to produce useful end products will benefit many industries and help preserve the environment. The research reported in this paper is an investigation on the use of the natural waste of palm kernel cake (PKC) to produce carbon residue as a black carbon for pigment source by using pyrolysis process. The activated carbons (AC) is produced in powder form using ball milling process. Rheological spectra in ink is one of quality control process in determining its performance properties. Findings from this study will help expand the scientific knowledge-base for black ink production and formulation base on PKC. Various inks with different weight percentage compositions of AC will be made and tested against its respective rheological properties in order to determine ideal ink printing system. The items in the formulation used comprised of organic and bio-waste materials with added additive to improve the quality of the black ink. Modified Polyurethane was used as binder. The binder's properties highlighted an ideal vehicle to be applied for good black ink opacity performance. The rheological behaviour is a general foundation for ink characterization where the wt% of AC-PKC resulted in different pseudoplastic behaviors, including the Newtonian behavior. The result found that Newtonian field was located in between 2 wt% and 10 wt% of AC-PKC composition with binder. Mass spectroscopy results shown that the carbon content in PKC is high and very suitable for black performance. In the ageing test, the pigment of PKC perform fairly according to the standard pigment of Black carbon (CB) of ferum oxide pigment. The contact angle for substrate's wettability of the ink system shown a good angle proven to be a water resistive coating on paper subtrates; an advantage of the PKC ink pigment performance.

  5. A Community Network of 100 Black Carbon Sensors

    Science.gov (United States)

    Preble, C.; Kirchstetter, T.; Caubel, J.; Cados, T.; Keeling, C.; Chang, S.

    2017-12-01

    We developed a low-cost black carbon sensor, field tested its performance, and then built and deployed a network of 100 sensors in West Oakland, California. We operated the network for 100 days beginning mid-May 2017 to measure spatially resolved black carbon concentrations throughout the community. West Oakland is a San Francisco Bay Area mixed residential and industrial community that is adjacent to regional port and rail yard facilities and surrounded by major freeways. As such, the community is affected by diesel particulate matter emissions from heavy-duty diesel trucks, locomotives, and ships associated with freight movement. In partnership with Environmental Defense Fund, the Bay Area Air Quality Management District, and the West Oakland Environmental Indicators Project, we deployed the black carbon monitoring network outside of residences and business, along truck routes and arterial streets, and at upwind locations. The sensor employs the filter-based light transmission method to measure black carbon and has good precision and correspondence with current commercial black carbon instruments. Throughout the 100-day period, each of the 100 sensors transmitted data via a cellular network. A MySQL database was built to receive and manage the data in real-time. The database included diagnostic features to monitor each sensor's operational status and facilitate the maintenance of the network. Spatial and temporal patterns in black carbon concentrations will be presented, including patterns around industrial facilities, freeways, and truck routes, as well as the relationship between neighborhood concentrations and the BAAQMD's monitoring site. Lessons learned during this first of its kind black carbon monitoring network will also be shared.

  6. Graft polymerization of vynil monomers at carbon black surface (1)

    International Nuclear Information System (INIS)

    Haryono Arumbinang.

    1976-01-01

    Effect of aromatic condensates containing functional group on carbon black surface, effect of pH condensates on carbon black chemisorption, analysis and configuration of functional group, the crystal structure, property measurement standard, particle diameter measurement, oil adsorption, colour capacity, volatile acid content, electric resistence and the volume of the granular or carbon black dust, are given. Electron paramagnetic resonance determination of the amount of free radicals on carbon black surface, its oxidation and effects on the surface and inner structure of carbon black, and graft polymerization by radiation copolymerization, are discussed. Experiments on radiation graft copolymerization by acrylic acid, methacrylate, and glycidol methacrylate, in a vacuum condition, have been carried out. It is concluded that further research on the modification and configuration of carbon black should be developed. (author)

  7. Historical sources of black carbon identified by PAHs and δ13C in Sanjiang Plain of Northeastern China

    Science.gov (United States)

    Gao, Chuanyu; Liu, Hanxiang; Cong, Jinxin; Han, Dongxue; Zhao, Winston; Lin, Qianxin; Wang, Guoping

    2018-05-01

    Black carbon (BC), the byproduct of incomplete combustion of fossil fuels and biomass can be stored in soil for a long time and potentially archive changes in natural and human activities. Increasing amounts of BC has been produced from human activities during the past 150 years and has influenced global climate change and carbon cycle. Identifying historical BC sources is important in knowing how historical human activities influenced BC and BC transportation processes in the atmosphere. In this study, PAH components and δ13C-BC in peatland in the Sanjiang Plain were used for identifying and verifying regional BC sources during the last 150 years. Results showed that environment-unfriendly industry developed at the end of the 1950s produced a great amount of BC and contributed the most BC in this period. In other periods, however, BC in the Sanjiang Plain was mainly produced from incomplete biomass burning before the 1990s; particularly, slash-and-burn of pastures and forests during regional reclamation periods between the 1960s and 1980s produced a huge amount of biomass burning BC, which then deposited into the surrounding ecosystems. With the regional reclamation decreasing and environment-friendly industry developing, the proportion of BC emitted and deposited from transportation sources increased and transportation source became an important BC source in the Sanjiang Plain after the 1990s.

  8. Black carbon sequestration as an alternative to bioenergy

    International Nuclear Information System (INIS)

    Fowles, Malcolm

    2007-01-01

    Most policy and much research concerning the application of biomass to reduce global warming gas emissions has concentrated either on increasing the Earth's reservoir of biomass or on substituting biomass for fossil fuels, with or without CO 2 sequestration. Suggested approaches entail varied risks of impermanence, delay, high costs, and unknowable side-effects. An under-researched alternative approach is to extract from biomass black (elemental) carbon, which can be permanently sequestered as mineral geomass and may be relatively advantageous in terms of those risks. This paper reviews salient features of black carbon sequestration and uses a high-level quantitative model to compare the approach with the alternative use of biomass to displace fossil fuels. Black carbon has been demonstrated to produce significant benefits when sequestered in agricultural soil, apparently without bad side-effects. Black carbon sequestration appears to be more efficient in general than energy generation, in terms of atmospheric carbon saved per unit of biomass; an exception is where biomass can efficiently displace coal-fired generation. Black carbon sequestration can reasonably be expected to be relatively quick and cheap to apply due to its short value chain and known technology. However, the model is sensitive to several input variables, whose values depend heavily on local conditions. Because characteristics of black carbon sequestration are only known from limited geographical contexts, its worldwide potential will not be known without multiple streams of research, replicated in other contexts. (author)

  9. Monumental heritage exposure to urban black carbon pollution

    Science.gov (United States)

    Patrón, D.; Lyamani, H.; Titos, G.; Casquero-Vera, J. A.; Cardell, C.; Močnik, G.; Alados-Arboledas, L.; Olmo, F. J.

    2017-12-01

    In this study, aerosol light-absorption measurements obtained at three sites during a winter campaign were used to analyse and identify the major sources of Black Carbon (BC) particles in and around the Alhambra monument, a UNESCO World Heritage Site that receives over 2 million visitors per year. The Conditional Bivariate Probability Function and the Aethalometer model were employed to identify the main sources of BC particles and to estimate the contributions of biomass burning and fossil fuel emissions to the total Equivalent Black Carbon (EBC) concentrations over the monumental complex. Unexpected high levels of EBC were found at the Alhambra, comparable to those measured in relatively polluted European urban areas during winter. EBC concentrations above 3.0 μg/m3, which are associated with unacceptable levels of soiling and negative public reactions, were observed at Alhambra monument on 13 days from 12 October 2015 to 29 February 2016, which can pose a risk to its long-term conservation and may cause negative social and economic impacts. It was found that road traffic emissions from the nearby urban area and access road to the Alhambra were the main sources of BC particles over the monument. However, biomass burning emissions were found to have very small impact on EBC concentrations at the Alhambra. The highest EBC concentrations were observed during an extended stagnant episode associated with persistent high-pressure systems, reflecting the large impact that can have these synoptic conditions on BC over the Alhambra.

  10. Structure aggregation of carbon black in ethylene-propylene diene polymer

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available The modulus of filled and unfilled Ethylene-propylene diene rubber (EPDM vulcanizates was used to predict the shape-factor of carbon black aggregation in the polymer. Four types of carbon black that vary in particle size and structure were used in this study. Quadratic curves relating the carbon black volume concentration and the modulus ratio of filled and unfilled rubber vulcanizates were used to adopt the shape factor of certain carbon black type. The shape factor of MT, HAF, SRF and Lampblack were 3, 3.75, 4 and 4.25 respectively. X-ray diffraction technique (XRD was also used to evaluate the relative size of crystallite on the filler surface to that of the rubber and correlating it to the shape factor of carbon black aggregation in the polymer. Effect of the pH values and structure of carbon blacks used on the shape factor of filler aggregates were also studied. It was found that the shape factor is independent on the particle size while it is dependent on the pH value and structure of carbon black. Also the crystallites size of the filler is proportional to the shape factor.

  11. Bird specimens track 135 years of atmospheric black carbon and environmental policy

    Science.gov (United States)

    DuBay, Shane G.; Fuldner, Carl C.

    2017-10-01

    Atmospheric black carbon has long been recognized as a public health and environmental concern. More recently, black carbon has been identified as a major, ongoing contributor to anthropogenic climate change, thus making historical emission inventories of black carbon an essential tool for assessing past climate sensitivity and modeling future climate scenarios. Current estimates of black carbon emissions for the early industrial era have high uncertainty, however, because direct environmental sampling is sparse before the mid-1950s. Using photometric reflectance data of >1,300 bird specimens drawn from natural history collections, we track relative ambient concentrations of atmospheric black carbon between 1880 and 2015 within the US Manufacturing Belt, a region historically reliant on coal and dense with industry. Our data show that black carbon levels within the region peaked during the first decade of the 20th century. Following this peak, black carbon levels were positively correlated with coal consumption through midcentury, after which they decoupled, with black carbon concentrations declining as consumption continued to rise. The precipitous drop in atmospheric black carbon at midcentury reflects policies promoting burning efficiency and fuel transitions rather than regulating emissions alone. Our findings suggest that current emission inventories based on predictive modeling underestimate levels of atmospheric black carbon for the early industrial era, suggesting that the contribution of black carbon to past climate forcing may also be underestimated. These findings build toward a spatially dynamic emission inventory of black carbon based on direct environmental sampling.

  12. Electrical conductivity of short carbon fibers and carbon black-reinforced chloroprene rubber

    International Nuclear Information System (INIS)

    Khoshniat, A. R.; MirAli, M.; Hemmati, M.; Afshar Taromi, F.; Katbab, A.

    2002-01-01

    Elastomers and plastics are intrinsically insulating materials, but by addition of some conductive particles such as conductive carbon black, carbon fibers and metals, they can change to conductive form. Conductivity of these composites are due to formation of the lattices of conductive filler particles in polymer chains. In this report, conductivity of chloroprene rubber filled with carbon black and carbon fibers as a function of temperature and pressure are studied. Electrical conductivity of chloroprene in a function of temperature and pressure are studied. Electrical conductivity of chloroprene in the presence of carbon black with proper mixing conditions increases to the conductivity level of semiconductors and even in the presence of carbon fibers it increases to the level of a conductor material. Meanwhile, the sensitivity of this compound to heat and pressure rises. Thus these composites have found various applications in the manufacture of heat and pressure sensitive sensors

  13. Comparison of carbon onions and carbon blacks as conductive additives for carbon supercapacitors in organic electrolytes

    Science.gov (United States)

    Jäckel, N.; Weingarth, D.; Zeiger, M.; Aslan, M.; Grobelsek, I.; Presser, V.

    2014-12-01

    This study investigates carbon onions (∼400 m2 g-1) as a conductive additive for supercapacitor electrodes of activated carbon and compares their performance with carbon black with high or low internal surface area. We provide a study of the electrical conductivity and electrochemical behavior between 2.5 and 20 mass% addition of each of these three additives to activated carbon. Structural characterization shows that the density of the resulting film electrodes depends on the degree of agglomeration and the amount of additive. Addition of low surface area carbon black (∼80 m2 g-1) enhances the power handling of carbon electrodes but significantly lowers the specific capacitance even when adding small amounts of carbon black. A much lower decrease in specific capacitance is observed for carbon onions and the best values are seen for carbon black with a high surface area (∼1390 m2 g-1). The overall performance benefits from the addition of any of the studied additives only at either high scan rates and/or electrolytes with high ion mobility. Normalization to the volume shows a severe decrease in volumetric capacitance and only at high current densities nearing 10 A g-1 we can see an improvement of the electrode capacitance.

  14. High Altitude Emissions of Black Carbon Aerosols: Potential Climate Implications

    Science.gov (United States)

    Satheesh, S. K.

    2017-12-01

    Synthesizing a series of ground-based and airborne measurements of aerosols over the Indian region during summer and pre-monsoon seasons have revealed the persistence of elevated absorbing aerosol layers over most of the Indian region; more than 50% of which located above clouds. Subsequent, in situ measurements of black carbon (BC) using high-altitude balloons, showed surprising layers with high concentrations in the middle and upper troposphere even at an altitude of 8 to 10 kms. Simultaneous measurements of the vertical thermal structure have shown localized warming due to BC absorption leading to large reduction in lapse rate and sharp temperature inversion, which in turn increases the atmospheric stability. This aerosol-induced stable layer is conducive for maintaining the black carbon layer longer at that level, leading thereby to further solar absorption and subsequently triggering dry convection. These observations support the `solar escalator' concept through which absorption-warming-convection cycles lead to self-lifting of BC to upper troposphere or even to lower stratosphere under favorable conditions in a matter of a few days. Employing an on-line regional chemistry transport model (WRF-Chem), incorporating aircraft emissions, it is shown that emissions from high-flying aircrafts as the most likely source of these elevated black carbon layers. These in-situ injected particles, produce significant warming of the thin air in those heights and lift these layers to even upper tropospheric/lower stratospheric heights, aided by the strong monsoonal convection occurring over the region, which are known to overshoot the tropical tropopause leading to injection of tropospheric air mass (along with its constituent aerosols) into the stratosphere, especially during monsoon season when the tropical tropopause layer is known to be thinnest. These simulations are further supported by the CALIPSO space-borne LIDAR derived extinction coefficient profiles. Based on

  15. Commuter exposure to black carbon, carbon monoxide, and noise in the mass transport khlong boats of Bangkok, Thailand

    Science.gov (United States)

    Ziegler, A. D.; Velasco, E.; Ho, K. J.

    2013-12-01

    Khlong (canal) boats are a unique mass transport alternative in the congested city of Bangkok. Canals and rivers provide exclusive transit-ways for reducing the commuting time of thousands of city residents daily. However, as a consequence of the service characteristics and boats design and state of repair, they can represent a potential public health risk and an important source of black carbon and greenhouse gases. This work quantifies commuter exposure to black carbon, CO and noise when waiting for and travelling in these diesel fueled boats. Exposure to toxic pollutants and acute noise is similar or worse than for other transportation modes. Mean black carbon concentrations observed at one busy pier and along the main canal were much higher than ambient concentrations at sites impacted by vehicular traffic. Concentrations of CO were similar to those reported for roadside areas of Bangkok. The equivalent continuous sound levels registered at the landing pier were similar to those reported for roadsides, but values recorded inside the boats were significantly higher. We believe that the boat service is a viable alternative mode of mass transport, but public safety could be improved to provide a high quality service, comparable to modern rail systems or emerging bus rapid transit systems. These investments would also contribute to reduce the emission of black carbon and other greenhouse and toxic pollutants.

  16. Black carbon radiative forcing at TOA decreased during aging.

    Science.gov (United States)

    Wu, Yu; Cheng, Tianhai; Zheng, Lijuan; Chen, Hao

    2016-12-05

    During aging processing, black carbon (also called soot) particles may tend to be mixed with other aerosols, and highly influence their radiative forcing. In this study, freshly emitted soot particles were simulated as fractal aggregates composed of small spherical primary monomers. After aging in the atmosphere, soot monomers were coated by a thinly layer of sulfate as thinly coated soot particles. These soot particles were entirely embedded into large sulfate particle by further aging, and becoming heavily coated soot particles. In clear-sky conditions, black carbon radiative forcing with different aging states were investigated for the bottom and top of atmosphere (BOA and TOA). The simulations showed that black carbon radiative forcing increased at BOA and decreased at TOA after their aging processes. Thinly and heavily coated states increased up to ~12% and ~35% black carbon radiative forcing at BOA, and black carbon radiative forcing at TOA can reach to ~20% and ~100% smaller for thinly and heavily coated states than those of freshly emitted states, respectively. The effect of aging states of black carbon radiative forcing was varied with surface albedo, aerosol optical depth and solar zenith angles. These findings would be helpful for the assessments of climate change.

  17. The vacuum pyrolysis of used tires. End-uses for oil and carbon black products

    Energy Technology Data Exchange (ETDEWEB)

    Roy, C.; Chaala, A.; Darmstadt, H. [Institut Pyrovac Inc., Parc Technologique du Quebec Metropolitain, rue Franquet, Sainte-Foy (Canada)

    1999-07-01

    By vacuum pyrolysis, the rubber portion of used tires is transformed into oil and gas and the carbon black filler is recovered as pyrolytic carbon black (CB{sub P}). Several commercial applications for the different products have been investigated and are reported in this article. CB{sub P} surface chemistry and activity are similar to those of commercial carbon blacks. Therefore, CB{sub P} has the potential to replace commercial carbon black grades in certain rubber applications. CB{sub P} was successfully tested as a filler in road pavement. The total pyrolytic oil can be used as a liquid fuel. The oil can also be distilled into different fractions: a light, a middle distillate and a heavy fraction. The light fraction was positively tested as a gasoline additive. Furthermore, this fraction contains valuable chemicals such as d,l-limonene. The middle fraction was successfully tested as a plasticizer in rubbers. The heavy fraction represents a good-quality feedstock for the production of coke and can also be used in road pavements. The pyrolytic gas can be used as a make-up heat source for the pyrolysis process

  18. Carbon nanotube-based black coatings

    Science.gov (United States)

    Lehman, J.; Yung, C.; Tomlin, N.; Conklin, D.; Stephens, M.

    2018-03-01

    Coatings comprising carbon nanotubes are very black, that is, characterized by uniformly low reflectance over a broad range of wavelengths from the visible to far infrared. Arguably, there is no other material that is comparable. This is attributable to the intrinsic properties of graphitic material as well as the morphology (density, thickness, disorder, and tube size). We briefly describe a history of other coatings such as nickel phosphorous, gold black, and carbon-based paints and the comparable structural morphology that we associate with very black coatings. The need for black coatings is persistent for a variety of applications ranging from baffles and traps to blackbodies and thermal detectors. Applications for space-based instruments are of interest and we present a review of space qualification and the results of outgassing measurements. Questions of nanoparticle safety depend on the nanotube size and aspect ratio as well as the nature and route of exposure. We describe the growth of carbon nanotube forests along with the catalyst requirements and temperature limitations. We also describe coatings derived from carbon nanotubes and applied like paint. Building the measurement apparatus and determining the optical properties of something having negligible reflectance are challenging and we summarize the methods and means for such measurements. There exists information in the literature for effective media approximations to model the dielectric function of vertically aligned arrays. We summarize this along with the refractive index of graphite from the literature that is necessary for modeling the optical properties. In our experience, the scientific questions can be overshadowed by practical matters, so we provide an appendix of recipes for making as-grown and sprayed coatings along with an example of reflectance measurements.

  19. Toxicity assessment of carbon black waste: A by-product from oil refineries

    Energy Technology Data Exchange (ETDEWEB)

    Zhen, Xu; Ng, Wei Cheng [NUS Environmental Research Institute, National University of Singapore, 1 Create Way, Create Tower #15-02, 138602 (Singapore); Fendy; Tong, Yen Wah [Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 (Singapore); Dai, Yanjun [School of Mechanical Engineering, Shanghai Jiaotong University, Shanghai, 200240 (China); Neoh, Koon Gee, E-mail: chenkg@nus.edu.sg [Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 (Singapore); Wang, Chi-Hwa, E-mail: chewch@nus.edu.sg [Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 (Singapore)

    2017-01-05

    Highlights: • Carbon black waste extract decreased cell viability in a dose and time-dependent manner. • Apoptosis of human cell lines was induced by carbon black waste extract. • Carbon black waste extract elicited oxidative stress by increasing intracellular ROS generation. • Carbon black waste extract impaired antioxidant enzymatic activities of human cell lines. • The high toxicity of carbon black waste extract could be attributed mainly to the effect of vanadium. - Abstract: In Singapore, approximately 30 t/day of carbon-based solid waste are produced from petrochemical processes. This carbon black waste has been shown to possess physical properties that are characteristic of a good adsorbent such as high external surface area. Therefore, there is a growing interest to reutilize and process this carbon black waste into secondary materials such as adsorbents. However, the carbon black waste obtained from petrochemical industries may contain heavy metals that are hazardous to human health and the environment, hence restricting its full potential for re-utilization. Therefore, it is important to examine the possible toxicity effects and toxicity mechanism of carbon black waste on human health. In this study, inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis showed that the heavy metals, vanadium (V), molybdenum (Mo) and nickel (Ni), were present in the carbon black waste in high concentrations. Three human cell lines (HepG2 cells, MRC-5 cells and MDA-MB-231 cells) were used to investigate the toxicity of carbon black waste extract in a variety of in vitro assays. Results from MTS assays indicated that carbon black waste extract decreased the viability of all three cell lines in a dose and time-dependent manner. Observations from confocal microscopy further confirmed this phenomenon. Flow cytometry assay also showed that carbon black waste extract induced apoptosis of human cell lines, and the level of apoptosis increased with

  20. Toxicity assessment of carbon black waste: A by-product from oil refineries

    International Nuclear Information System (INIS)

    Zhen, Xu; Ng, Wei Cheng; Fendy; Tong, Yen Wah; Dai, Yanjun; Neoh, Koon Gee; Wang, Chi-Hwa

    2017-01-01

    Highlights: • Carbon black waste extract decreased cell viability in a dose and time-dependent manner. • Apoptosis of human cell lines was induced by carbon black waste extract. • Carbon black waste extract elicited oxidative stress by increasing intracellular ROS generation. • Carbon black waste extract impaired antioxidant enzymatic activities of human cell lines. • The high toxicity of carbon black waste extract could be attributed mainly to the effect of vanadium. - Abstract: In Singapore, approximately 30 t/day of carbon-based solid waste are produced from petrochemical processes. This carbon black waste has been shown to possess physical properties that are characteristic of a good adsorbent such as high external surface area. Therefore, there is a growing interest to reutilize and process this carbon black waste into secondary materials such as adsorbents. However, the carbon black waste obtained from petrochemical industries may contain heavy metals that are hazardous to human health and the environment, hence restricting its full potential for re-utilization. Therefore, it is important to examine the possible toxicity effects and toxicity mechanism of carbon black waste on human health. In this study, inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis showed that the heavy metals, vanadium (V), molybdenum (Mo) and nickel (Ni), were present in the carbon black waste in high concentrations. Three human cell lines (HepG2 cells, MRC-5 cells and MDA-MB-231 cells) were used to investigate the toxicity of carbon black waste extract in a variety of in vitro assays. Results from MTS assays indicated that carbon black waste extract decreased the viability of all three cell lines in a dose and time-dependent manner. Observations from confocal microscopy further confirmed this phenomenon. Flow cytometry assay also showed that carbon black waste extract induced apoptosis of human cell lines, and the level of apoptosis increased with

  1. Source apportionment of PM10 mass and particulate carbon in the Kathmandu Valley, Nepal

    Science.gov (United States)

    Kim, Bong Mann; Park, Jin-Soo; Kim, Sang-Woo; Kim, Hyunjae; Jeon, Haeun; Cho, Chaeyoon; Kim, Ji-Hyoung; Hong, Seungkyu; Rupakheti, Maheswar; Panday, Arnico K.; Park, Rokjin J.; Hong, Jihyung; Yoon, Soon-Chang

    2015-12-01

    The Kathmandu Valley in Nepal is a bowl-shaped urban basin in the Himalayan foothills with a serious problem of fine particulate air pollution that impacts local health and impairs visibility. Particulate carbon concentrations have reached severe levels that threaten the health of 3.5 million local residents. Moreover, snow and ice on the Himalayan mountains are melting as a result of additional warming due to particulate carbon, especially high black carbon concentrations. To date, the sources of the Valley's particulate carbon and the impacts of different sources on particulate carbon concentrations are not well understood. Thus, before an effective control strategy can be developed, these particulate carbon sources must be identified and quantified. Our study has found that the four primary sources of particulate carbon in the Kathmandu Valley during winter are brick kilns, motor vehicles, fugitive soil dust, and biomass/garbage burning. Their source contributions are quantified using a recently developed new multivariate receptor model SMP. In contrast to other highly polluted areas such as China, secondary contribution is almost negligible in Kathmandu Valley. Brick kilns (40%), motor vehicles (37%) and biomass/garbage burning (22%) have been identified as the major sources of elemental carbon (black carbon) in the Kathmandu Valley during winter, while motor vehicles (47%), biomass/garbage burning (32%), and soil dust (13%) have been identified as the most important sources of organic carbon. Our research indicates that controlling emissions from motor vehicles, brick kilns, biomass/garbage burning, and soil dust is essential for the mitigation of the particulate carbon that threatens public health, impairs visibility, and influences climate warming within and downwind from the Kathmandu Valley. In addition, this paper suggests several useful particulate carbon mitigation methods that can be applied to Kathmandu Valley and other areas in South Asia with

  2. Comparison Between Elemental Carbon Measured Using Thermal-Optical Analysis and Black Carbon Measurements Using A Novel Cellphone-Based System

    Science.gov (United States)

    Ramanathan, N.; Khan, B.; Leong, I.; Lukac, M.

    2011-12-01

    Black carbon (BC) is produced through the incomplete combustion of fossil and solid fuels. Current BC emissions inventories have large uncertainties of factors of 2 or more due to sparse measurements and because BC is often emitted by local sources that vary over time and space (Bond et al, 2004). Those uncertainties are major sources of error in air pollution models. Emissions from a variety of improved cookstove/fuel/combustion conditions were collected on pre-conditioned 47 mm quartz-fiber filters and analyzed for organic carbon (OC) and elemental carbon (EC) using thermal-optical analysis (TOA). The samples were then analyzed for BC concentration by using cellphone-based instrumentation developed by Ramanathan et al., 2011. The cellphone-based monitoring system (CBMS) is a wireless, low-cost, low-power system that monitors BC emissions. The CBMS is comprised of an aerosol filter sampler containing a battery-powered air pump and a 25mm filter holder that draws air in through a quartz-fiber filter. As black carbon deposits increase, the filter darkens--the darkest color representing the highest loading. A cellphone photograph of the filter with the black carbon deposit is taken and relayed to an analytics unit for comparison to a reference scale to estimate airborne BC concentration. The BC concentration can then be compared to the thermally derived EC concentration. TOA was conducted on a Sunset Laboratory Dual Optics Carbon Analyzer using a modified version of the Birch and Cary (1996) NIOSH 5040 protocol. The dual-optical instrument permitted simultaneous monitoring of the transmission (TOT) and reflectance (TOR). 619 samples were collected; EC was obtained using NIOSH TOT and NIOSH TOR methods, and BC was obtained using the CBMS analytics unit. The mean BC value reported by the CBMS agrees within 20% of the reference values for EC, confirming the findings in Ramanathan et al. (2011) based on samples from India. Given this accuracy, we conclude that the CBMS

  3. Gravimetric determination of the iodine number of carbon black

    International Nuclear Information System (INIS)

    Murphy, L.J. Jr.

    1991-01-01

    This paper discusses a gravimetric method for the determination of the iodine adsorption number of carbon black. It comprises determining the concentration of an accurately weighed iodine blank solution by adding a standardized titrant to the iodine solution until a titration endpoint is reached and determining the concentration of the iodine solution by accurately weighing the amount of the standardized titrant necessary to reach the endpoint, accurately weighing an amount of carbon black and adding an appropriate amount of an accurately weighed portion of the iodine solution, equilibrating the carbon black-iodine solution mixture, adding the standardized titrant to an accurately weighed portion of the supernatant from the carbon black-iodine mixture until a titration endpoint is reached and determining the concentration of the supernatant by accurately weighing the amount of the standardized titrant necessary to reach the endpoint, wherein the titration endpoint of the supernatant is obtained using an indicating and a reference electrode, and calculating the iodine adsorption number of the carbon black based on the gravimetrically determined concentration of the titrant, the iodine solution, and the supernatant

  4. Thermal properties of carbon black aqueous nanofluids for solar absorption

    Directory of Open Access Journals (Sweden)

    Han Dongxiao

    2011-01-01

    Full Text Available Abstract In this article, carbon black nanofluids were prepared by dispersing the pretreated carbon black powder into distilled water. The size and morphology of the nanoparticles were explored. The photothermal properties, optical properties, rheological behaviors, and thermal conductivities of the nanofluids were also investigated. The results showed that the nanofluids of high-volume fraction had better photothermal properties. Both carbon black powder and nanofluids had good absorption in the whole wavelength ranging from 200 to 2,500 nm. The nanofluids exhibited a shear thinning behavior. The shear viscosity increased with the increasing volume fraction and decreased with the increasing temperature at the same shear rate. The thermal conductivity of carbon black nanofluids increased with the increase of volume fraction and temperature. Carbon black nanofluids had good absorption ability of solar energy and can effectively enhance the solar absorption efficiency.

  5. Emissions of black carbon and co-pollutants emitted from diesel vehicles in the Mexico City Metropolitan Area

    Science.gov (United States)

    Zavala, Miguel; Molina, Luisa T.; Fortner, Edward; Knighton, Berk; Herndon, Scott; Yacovitch, Tara; Floerchinger, Cody; Roscioli, Joseph; Kolb, Charles; Mejia, Jose Antonio; Sarmiento, Jorge; Paramo, Victor Hugo; Zirath, Sergio; Jazcilevich, Aron

    2014-05-01

    Black carbon emitted from freight, public transport, and heavy duty trucks sources is linked with adverse effects on human health. In addition, the control of emissions of black carbon, an important short-lived climate forcing agent (SLCF), has recently been considered as one of the key strategies for mitigating regional near-term climate change. Despite the availability of new emissions control technologies for reducing emissions from diesel-powered mobile sources, their introduction is still not widespread in many urban areas and there is a need to characterize real-world emission rates of black carbon from this key source. The emissions of black carbon, organic carbon, and other gaseous and particle pollutants from diesel-powered mobile sources in Mexico were characterized by deploying a mobile laboratory equipped with real-time instrumentation in Mexico City as part of the SLCFs-Mexico 2013 project. From February 25-28 of 2013 the emissions from selected diesel-powered vehicles were measured in both controlled experiments and real-world on-road driving conditions. Sampled vehicles had several emissions levels technologies, including: EPA98, EPA03, EPA04, EURO3-5, and Hybrid. All vehicles were sampled using diesel fuel and several vehicles were measured using both diesel and biodiesel fuels. Additional measurements included the use of a remote sensing unit for the co-sampling of all tested vehicles, and the installation and operation of a Portable Emissions Measurements System (PEMS) for the measurement of emissions from a test vehicle. We will present inter-comparisons of the emission factors obtained among the various vehicle technologies that were sampled during the experiment as well as the inter-comparison of results from the various sampling platforms. The results can be used to

  6. Using measurements for evaluation of black carbon modeling

    Directory of Open Access Journals (Sweden)

    S. Gilardoni

    2011-01-01

    Full Text Available The ever increasing use of air quality and climate model assessments to underpin economic, public health, and environmental policy decisions makes effective model evaluation critical. This paper discusses the properties of black carbon and light attenuation and absorption observations that are the key to a reliable evaluation of black carbon model and compares parametric and nonparametric statistical tools for the quantification of the agreement between models and observations. Black carbon concentrations are simulated with TM5/M7 global model from July 2002 to June 2003 at four remote sites (Alert, Jungfraujoch, Mace Head, and Trinidad Head and two regional background sites (Bondville and Ispra. Equivalent black carbon (EBC concentrations are calculated using light attenuation measurements from January 2000 to December 2005. Seasonal trends in the measurements are determined by fitting sinusoidal functions and the representativeness of the period simulated by the model is verified based on the scatter of the experimental values relative to the fit curves. When the resolution of the model grid is larger than 1° × 1°, it is recommended to verify that the measurement site is representative of the grid cell. For this purpose, equivalent black carbon measurements at Alert, Bondville and Trinidad Head are compared to light absorption and elemental carbon measurements performed at different sites inside the same model grid cells. Comparison of these equivalent black carbon and elemental carbon measurements indicates that uncertainties in black carbon optical properties can compromise the comparison between model and observations. During model evaluation it is important to examine the extent to which a model is able to simulate the variability in the observations over different integration periods as this will help to identify the most appropriate timescales. The agreement between model and observation is accurately described by the overlap of

  7. Neutron scattering analysis of rubber carbon black composite structure

    International Nuclear Information System (INIS)

    Hjelm, R.P. Jr.; Wampler, W.A.; Gerspacher, M.

    1994-01-01

    We explore the uses of small-angle neutron scattering to dissect component form, structure and distribution in carbon black-reinforced rubber by varying the contrast of the system relative to some fluid by changing the fluid scattering-length density. This is the method of contrast variation. Contrast variation allows us to separate scattering contributions from the different components. Here, we extend our studies on high surface area (HSA) carbon black suspended in cyclohexane/deuterocyclohexane to HSA mixed with polyisoprene as a gel of ''bound'' rubber swollen with the same solvent mixtures. Contrast variation of swollen composite gels shows that there are two length scales in the gel structure. Above 1 nm fluctuations in the carbon black predominate. Interactions with elastomer hold the HSA aggregates appart. Below 1 nm the scattering is largely from the elastomer. The smooth surface structure of the carbon black is unaltered by the interactions with elastomer and appears smooth over length scales above about 1 nm. These results show that contrast variation can provide information on composite structure that is not available by other means. This information relates to the reinforcement mechanism of elastomers by carbon blacks

  8. Black carbon in aerosol during BIBLE B

    Science.gov (United States)

    Liley, J. Ben; Baumgardner, D.; Kondo, Y.; Kita, K.; Blake, D. R.; Koike, M.; Machida, T.; Takegawa, N.; Kawakami, S.; Shirai, T.; Ogawa, T.

    2003-02-01

    The Biomass Burning and Lightning Experiment (BIBLE) A and B campaigns over the tropical western Pacific during springtime deployed a Gulfstream-II aircraft with systems to measure ozone and numerous precursor species. Aerosol measuring systems included a MASP optical particle counter, a condensation nucleus (CN) counter, and an absorption spectrometer for black carbon. Aerosol volume was very low in the middle and upper troposphere during both campaigns, and during BIBLE A, there was little aerosol enhancement in the boundary layer away from urban areas. In BIBLE B, there was marked aerosol enhancement in the lowest 3 km of the atmosphere. Mixing ratios of CN in cloud-free conditions in the upper troposphere were in general higher than in the boundary layer, indicating new particle formation from gaseous precursors. High concentrations of black carbon were observed during BIBLE B, with mass loadings up to 40 μg m-3 representing as much as one quarter of total aerosol mass. Strong correlations with hydrocarbon enhancement allow the determination of a black carbon emission ratio for the fires at that time. Expressed as elemental carbon, it is about 0.5% of carbon dioxide and 6% of carbon monoxide emissions from the same fires, comparable to methane production, and greater than that of other hydrocarbons.

  9. Quantifying the variability of potential black carbon transport from cropland burning in Russia driven by atmospheric blocking events.

    Science.gov (United States)

    Hall, J.; Loboda, T. V.

    2017-12-01

    Short lived aerosols and pollutants transported from northern mid-latitudes have amplified the short term warming in the Arctic region. Specifically, black carbon is recognized as the second most important human emission in regards to climate forcing, behind carbon dioxide with a total climate forcing of +1.1Wm-2. Studies have suggested that cropland burning may be a large contributor to the black carbon emissions which are directly deposited on the snow in the Arctic region. However, accurate monitoring of cropland burning from existing active fire and burned area products is limited, thereby leading to an underestimation in black carbon emissions from cropland burning. This research focuses on 1) assessing the potential for the deposition of hypothetical black carbon emissions from known cropland burning in Russia through low-level transport, and 2) identifying a possible atmospheric pattern that may enhance the transport of black carbon emissions to the Arctic. Specifically, atmospheric blocking events present a potential mechanism that could act to enhance the likelihood of transport or accelerate the transport of pollutants to the snow-covered Arctic from Russian cropland burning based on their persistent wind patterns. This research study confirmed the importance of Russian cropland burning as a potential source of black carbon deposition on the Arctic snow in the spring despite the low injection heights associated with cropland burning. Based on the successful transport pathways, this study identified the potential transport of black carbon from Russian cropland burning beyond 80°N which has important implications for permanent sea ice cover. Further, based on the persistent wind patterns of blocking events, this study identified that blocking events are able to accelerate potential transport and increase the success of transport of black carbon emissions to the snow-covered Arctic during spring when the impact on the snow/ice albedo is at its highest. The

  10. Aerosol Absorption by Black Carbon and Dust: Implications of Climate Change and Air Quality in Asia

    Science.gov (United States)

    Chin, Mian

    2010-01-01

    Atmospheric aerosol distributions from 2000 to 2007 are simulated with the global model GOCART to attribute light absorption by aerosol to its composition and sources. We show the seasonal and interannual variations of absorbing aerosols in the atmosphere over Asia, mainly black carbon and dust. and their linkage to the changes of anthropogenic and dust emissions in the region. We compare our results with observations from satellite and ground-based networks, and estimate the importance of black carbon and dust on regional climate forcing and air quality.

  11. Synthesis of multiwalled carbon nanotube from different grades of carbon black using arc discharge method

    Energy Technology Data Exchange (ETDEWEB)

    Arora, Neha, E-mail: n4neha31@gmail.com [Department of Mechanical Engineering, Birla Institute of Technology and Science, Pilani (India); Sharma, N. N. [Department of Mechanical Engineering, Birla Institute of Technology and Science, Pilani (India); Director, School of Automobile, Mechanical & Mechatronics, Manipal University,Jaipur,India (India)

    2016-04-13

    This paper describes the synthesis of nanotube from different grades (Tread * A(non-ASTM), N134,N121,N660 and N330)of carbon black using DC arc discharge method at 40A current for 60sec. Carbon black samples of different grades were procured from industry (Aditya Birla Science and Technology Limited, India). Scanning Electron Micrographs (SEM) of the deposited carbon nanostructures suggests that MWCNTs are formed at 40A and for a minimal exposure time of 60sec.The result formed indicates the N330 grade of carbon black gets converted to MWCNTs (Multiwall Carbon nanotube) as compared to other grades.

  12. Modulation of snow reflectance and snowmelt from Central Asian glaciers by anthropogenic black carbon.

    Science.gov (United States)

    Schmale, Julia; Flanner, Mark; Kang, Shichang; Sprenger, Michael; Zhang, Qianggong; Guo, Junming; Li, Yang; Schwikowski, Margit; Farinotti, Daniel

    2017-01-12

    Deposited mineral dust and black carbon are known to reduce the albedo of snow and enhance melt. Here we estimate the contribution of anthropogenic black carbon (BC) to snowmelt in glacier accumulation zones of Central Asia based on in-situ measurements and modelling. Source apportionment suggests that more than 94% of the BC is emitted from mostly regional anthropogenic sources while the remaining contribution comes from natural biomass burning. Even though the annual deposition flux of mineral dust can be up to 20 times higher than that of BC, we find that anthropogenic BC causes the majority (60% on average) of snow darkening. This leads to summer snowmelt rate increases of up to 6.3% (7 cm a -1 ) on glaciers in three different mountain environments in Kyrgyzstan, based on albedo reduction and snowmelt models.

  13. Influence of carbon black distribution on performance of oxide cathodes for Li ion batteries

    International Nuclear Information System (INIS)

    Dominko, Robert; Gaberscek, Miran; Drofenik, Jernej; Bele, Marjan; Jamnik, Janez

    2003-01-01

    The influence of carbon black content and carbon black distribution on performance of oxide-based cathodes, such as LiCoO 2 and LiMn 2 O 4 , is investigated. The electronic conductivity of oxide material/carbon black composites is compared with electrochemical characteristics of the same composites. Uniformity of carbon black distribution in cathode composites is achieved using novel coating technology in cathode preparation. In this technology, the active particles are first pretreated in a gelatin solution. The adsorbed gelatin then controls the deposition of carbon black so that carbon black particles are uniformly distributed in the final composite. The influence of various parameters, such as pH of gelatin, amount of gelatin and concentration of carbon black on the uniformity of carbon black distribution is investigated. It is shown that the conventional technology of cathode preparation yields quite non-uniform distribution of carbon black in cathode material. At the end, we demonstrate that uniformity of carbon black distribution has a crucial impact on reversible capacity, especially at high current densities

  14. GHG and black carbon emission inventories from Mezquital Valley: The main energy provider for Mexico Megacity

    Energy Technology Data Exchange (ETDEWEB)

    Montelongo-Reyes, M.M.; Otazo-Sánchez, E.M.; Romo-Gómez, C.; Gordillo-Martínez, A.J.; Galindo-Castillo, E.

    2015-09-15

    The greenhouse gases and black carbon emission inventory from IPCC key category Energy was accomplished for the Mezquital Valley, one of the most polluted regions in Mexico, as the Mexico City wastewater have been continuously used in agricultural irrigation for more than a hundred years. In addition, thermoelectric, refinery, cement and chemistry industries are concentrated in the southern part of the valley, near Mexico City. Several studies have reported air, soil, and water pollution data and its main sources for the region. Paradoxically, these sources contaminate the valley, but boosted its economic development. Nevertheless, no research has been done concerning GHG emissions, or climate change assessment. This paper reports inventories performed by the 1996 IPCC methodology for the baseline year 2005. Fuel consumption data were derived from priority sectors such as electricity generation, refineries, manufacturing & cement industries, transportation, and residential use. The total CO{sub 2} emission result was 13,894.9 Gg, which constituted three-quarters of Hidalgo statewide energy category. The principal CO{sub 2} sources were energy transformation (69%) and manufacturing (19%). Total black carbon emissions were estimated by a bottom-up method at 0.66 Gg. The principal contributor was on-road transportation (37%), followed by firewood residential consumption (26%) and cocked brick manufactures (22%). Non-CO{sub 2} gas emissions were also significant, particularly SO{sub 2} (255.9 Gg), which accounts for 80% of the whole Hidalgo State emissions. Results demonstrated the negative environmental impact on Mezquital Valley, caused by its role as a Megacity secondary fuel and electricity provider, as well as by the presence of several cement industries. - Highlights: • First GHG & black carbon inventory for Mezquital Valley: Mexico City energy supplier • Energy industries caused the largest CO{sub 2} and SO{sub 2} emissions from residual fuel oil. • Diesel

  15. Preparation of carbon black masterbatch for PET using polymeric dispersing agents

    Energy Technology Data Exchange (ETDEWEB)

    Oh, D.H. [Kyungpook National University, Taegu (Korea, Republic of); Lim, J.C. [Pukyong National University, Pusan (Korea, Republic of); Seo, K.H. [Yeungnam College of Science and Technology, Taegu (Korea, Republic of)

    1999-03-01

    Three kinds of copolyesters, dispersing agents, were synthesized from the polycondensation reaction of dimethylterephthalate (DMT), dimethylisophthalate (DMI), sebacic acid (SA), and 1,4-butanediol (BD). Carbon black masterbatches were prepared by mixing carbon black into the dispersing agents (1 : 1.3 weight ratio) in a Brabender Plasticorder Using single screw extruder, masterbatches were compounded with poly(ethylene terephthalate) in 3 wt% concentration and mechanical properties of the compounds were investigated Gel permeation chromatography data implied that thermal degradation of polymeric dispersing agents was not significant through dispersion. Capillary rheometer test showed that PBTI has the highest viscosity and shear sensitivity among the there dispersing agents. Volume resistivities of masterbatch and transmission electron micrographs showed that dispersity of carbon black was improved with increasing melt viscosity of dispersing agent. The ultimate performance and mechanical characteristics of carbon black filled PET compounds depended directly on dispersion quality of the carbon black in masterbatch. Mechanical properties of compounds were improved with increasing dispersity of carbon black and with increasing content of rigid aromatic group in the copolyester dispersing agent. 30 refs., 9 figs., 5 tabs.

  16. Invited article summarizing the Science To Achieve Results research portfolio on Black Carbon for the journal EM of the Air and Waste Management Association.

    Science.gov (United States)

    Where there’s smoke, there’s fire – and black carbon. Black carbon is the sooty material emitted from combustion processes, including diesel engines and other sources that burn fossil fuels, biofuels, or biomass. This soot contributes to fine particulate matter,...

  17. The relationship between carbon stable isotope ratios of hatchling down and egg yolk in Black-headed Gulls

    NARCIS (Netherlands)

    Klaassen, M.R.J.; Baarspul, T.; Dekkers, T.; Van Tienen, P.

    2004-01-01

    We reconstructed the nutrient source for egg synthesis by sampling Black-headed Gull (Larus ridibundus) eggs for yolk, analyzing their carbon stable isotope ratio, and comparing that to hatchling down. Most of the variation in carbon stable isotope ratio was explained by differences between nests,

  18. Time-resolved analysis of particle emissions from residential biomass combustion - Emissions of refractory black carbon, PAHs and organic tracers

    Science.gov (United States)

    Nielsen, Ingeborg E.; Eriksson, Axel C.; Lindgren, Robert; Martinsson, Johan; Nyström, Robin; Nordin, Erik Z.; Sadiktsis, Ioannis; Boman, Christoffer; Nøjgaard, Jacob K.; Pagels, Joakim

    2017-09-01

    Time-resolved particle emissions from a conventional wood stove were investigated with aerosol mass spectrometry to provide links between combustion conditions, emission factors, mixing state of refractory black carbon and implications for organic tracer methods. The addition of a new batch of fuel results in low temperature pyrolysis as the fuel heats up, resulting in strong, short-lived, variable emission peaks of organic aerosol-containing markers of anhydrous sugars, such as levoglucosan (fragment at m/z 60). Flaming combustion results in emissions dominated by refractory black carbon co-emitted with minor fractions of organic aerosol and markers of anhydrous sugars. Full cycle emissions are an external mixture of larger organic aerosol-dominated and smaller thinly coated refractory black carbon particles. A very high burn rate results in increased full cycle mass emission factors of 66, 2.7, 2.8 and 1.3 for particulate polycyclic aromatic hydrocarbons, refractory black carbon, total organic aerosol and m/z 60, respectively, compared to nominal burn rate. Polycyclic aromatic hydrocarbons are primarily associated with refractory black carbon-containing particles. We hypothesize that at very high burn rates, the central parts of the combustion zone become air starved, leading to a locally reduced combustion temperature that reduces the conversion rates from polycyclic aromatic hydrocarbons to refractory black carbon. This facilitates a strong increase of polycyclic aromatic hydrocarbons emissions. At nominal burn rates, full cycle emissions based on m/z 60 correlate well with organic aerosol, refractory black carbon and particulate matter. However, at higher burn rates, m/z 60 does not correlate with increased emissions of polycyclic aromatic hydrocarbons, refractory black carbon and organic aerosol in the flaming phase. The new knowledge can be used to advance source apportionment studies, reduce emissions of genotoxic compounds and model the climate impacts of

  19. Reinforcement of Multiwalled Carbon Nanotube in Nitrile Rubber: In Comparison with Carbon Black, Conductive Carbon Black, and Precipitated Silica

    Directory of Open Access Journals (Sweden)

    Atip Boonbumrung

    2016-01-01

    Full Text Available The properties of nitrile rubber (NBR reinforced by multiwalled carbon nanotube (MWCNT, conductive carbon black (CCB, carbon black (CB, and precipitated silica (PSi were investigated via viscoelastic behavior, bound rubber content, electrical properties, cross-link density, and mechanical properties. The filler content was varied from 0 to 15 phr. MWCNT shows the greatest magnitude of reinforcement considered in terms of tensile strength, modulus, hardness, and abrasion resistance followed by CCB, CB, and PSi. The MWCNT filled system also exhibits extremely high levels of filler network and trapped rubber even at relatively low loading (5 phr leading to high electrical properties and poor dynamic mechanical properties. Although CCB possesses the highest specific surface area, it gives lower level of filler network than MWCNT and also gives the highest elongation at break among all fillers. Both CB and PSi show comparable degree of reinforcement which is considerably lower than CCB and MWCNT.

  20. Advantage of SBR/carbon black masterbatch for tire tread application

    Energy Technology Data Exchange (ETDEWEB)

    Sone, K.; Ishiguro, M.; Akimoto, H.; Ishida, M.

    1992-04-01

    The performance required of tire tread is becoming more severe and more various year by year, as social demands on tires have been changing. To improve wear resistance, driving safety and good drive feeling, new HP tires (high performance passenger car tires) are developed intensively. In addition, good fuel efficiency is required to satisfy the CAFE rule, which was proposed for a better global environment. To support this movement of the tire industry, material suppliers are making an effort to supply better materials. Mitsubishi Kasei has been improving the quality and production process of WMB, a SBR/carbon black master-batch produced by co-coagulation of SBR latex, carbon black and extender oil under the wet dispersion process. Compared to the tire tread made from dry-mixing compounds, that made from the WMB shows the following characteristics: (1) the abrasion resistance and the durability are higher; (2) from the viscoelastic properties, skid performance and driving stability are expected to be improved. These characteristics are remarkable when WMB is compounded in the recipes for HP and racing tires using fine carbon black. In this article, these features of WMB are studied from the view point of carbon black dispersion and polymer-carbon black interaction. Furthermore, the changes of carbon black structure during abrasion and fatigue process are analyzed and the mechanisms of these processes are discussed.

  1. Fiber-based broadband black-light source

    OpenAIRE

    Sylvestre , Thibaut; Lee , Min Won; Ragueh , A. R.; Stiller , Birgit; Fanjoux , Gil; Barviau , B.; Mussot , A.; Kudlinski , A.

    2012-01-01

    International audience; Black-Light or Wood's lamp refers to sources that emit long-wavelength ultraviolet radiation (UV-A) from 315 nm and little visible light till 410 nm (blue). In this paper, we present a new fibre-based source of "black light", a source that emits broadband ultraviolet radiation but only small amounts of visible light and no infrared light. We made this source by pumping a specially designed silica photonic crystal fibre (PCF) with 355 nm light pulses from a Q-switched f...

  2. Achieving high performance in intermediate temperature direct carbon fuel cells with renewable carbon as a fuel source

    International Nuclear Information System (INIS)

    Hao, Wenbin; He, Xiaojin; Mi, Yongli

    2014-01-01

    Highlights: • Bamboo fiber and waste paper were pyrolyzed to generate bamboo carbon and waste paper carbon as anode fuels of IT-DCFC. • Superior cell performance was achieved with the waste paper carbon. • The results suggested the high performance was due to the highest thermal reactivity and the catalytic inherent impurities. • Calcite and kaolinite as inherent impurities favored the thermal decomposition and the electrooxidation of carbon. - Abstract: Three kinds of carbon sources obtained from carbon black, bamboo fiber and waste paper were investigated as anode fuels in an intermediate temperature direct carbon fuel cell. The carbon sources were characterized with X-ray photoelectron spectroscopy, thermal gravimetric analysis, etc. The results indicated that the waste paper carbon was more abundant in calcite and kaolinite, and showed higher thermal reactivity in the intermediate temperature range compared with the other two carbon sources. The cell performance was tested at 650 °C in a hybrid single cell, using Sm 0.20 Ce 0.80 O 2−x as the electrolyte. As a result, the cell fed with waste paper carbon showed the highest performance among the three carbon sources, with a peak power density of 225 mW cm −2 . The results indicated that its inherent impurities, such as calcite and kaolinite, might favor the thermal gasification of renewable carbon sources, which resulted in the enhanced performance of the intermediate temperature direct carbon fuel cell

  3. Study of the effect of gamma irradiation on carbon black loaded low-density polyethylene films

    International Nuclear Information System (INIS)

    Salem, M.A.; Hussein, A.; El-Ahdal, M.A.

    2003-01-01

    The effect of gamma irradiation on the tensile and physico-chemical properties of low-density polyethylene (LDPE) films loaded with different concentrations of carbon black (C.B) has been studied. The results showed that the behavior of the samples during gamma irradiation is complicated and this may be due to scission and the interaction between oxidation and crosslinking processes. The tensile properties are modified by the presence of carbon black. Film sample containing 7% C.B was found to exhibit a nearly stabilized tensile behavior with radiation dose, which allows to use this formulation in packaging for food sterilization and in preservation of weak cobalt-gamma sources. (author)

  4. Influence of sample composition on aerosol organic and black carbon determinations

    Energy Technology Data Exchange (ETDEWEB)

    Novakov, T.; Corrigan, C.E.

    1995-07-01

    In this paper we present results on characterization of filter-collected redwood (Sequoia sempevirens)-needle and eucalyptus smoke particles by thermal, optical, and solvent extraction methods. Our results demonstrate that organic and black carbon concentrations determined by thermal and optical methods are not only method dependent, but also critically influenced by the overall chemical composition of the samples. These conclusions are supported by the following: (1) the organic fraction of biomass smoke particles analyzed includes a component, ranging in concentration from about 6-20% of total carbon or from 16-30% of organic carbon, that is relatively non-volatile and has a combustion temperature close to that of black carbon; (2) presence of K or Na in biomass smoke samples lowers the combustion temperatures of this organic component and of black carbon, making their combustion properties indistinguishable; (3) about 20% of total organic material is nonvolatile when heated to 550{degrees}C in an inert atmosphere. Consequently, thermal methods that rely on a specific temperature to separate organic from black carbon may either underestimate or overestimate the black and organic carbon concentrations, depending on the amounts of Na and K and on the composition and concentration of organic material present in a sample. These analytical uncertainties and, under some conditions, absorption by organic material may contribute to the variability of empirically derived proportionality between light transmission through filter deposits and black carbon concentrations.

  5. Influence of sample composition on aerosol organic and black carbon determinations

    International Nuclear Information System (INIS)

    Novakov, T.; Corrigan, C.E.

    1995-07-01

    In this paper we present results on characterization of filter-collected redwood (Sequoia sempevirens)-needle and eucalyptus smoke particles by thermal, optical, and solvent extraction methods. Our results demonstrate that organic and black carbon concentrations determined by thermal and optical methods are not only method dependent, but also critically influenced by the overall chemical composition of the samples. These conclusions are supported by the following: (1) the organic fraction of biomass smoke particles analyzed includes a component, ranging in concentration from about 6-20% of total carbon or from 16-30% of organic carbon, that is relatively non-volatile and has a combustion temperature close to that of black carbon; (2) presence of K or Na in biomass smoke samples lowers the combustion temperatures of this organic component and of black carbon, making their combustion properties indistinguishable; (3) about 20% of total organic material is nonvolatile when heated to 550 degrees C in an inert atmosphere. Consequently, thermal methods that rely on a specific temperature to separate organic from black carbon may either underestimate or overestimate the black and organic carbon concentrations, depending on the amounts of Na and K and on the composition and concentration of organic material present in a sample. These analytical uncertainties and, under some conditions, absorption by organic material may contribute to the variability of empirically derived proportionality between light transmission through filter deposits and black carbon concentrations

  6. Electrical conductivity of conductive carbon blacks: influence of surface chemistry and topology

    International Nuclear Information System (INIS)

    Pantea, Dana; Darmstadt, Hans; Kaliaguine, Serge; Roy, Christian

    2003-01-01

    Conductive carbon blacks from different manufacturers were studied in order to obtain some insight into the relation between their electrical conductivity and their surface properties. The surface chemistry was studied by X-ray photoelectron spectroscopy (XPS) and static secondary ion mass spectroscopy (SIMS), whereas the topology of the carbon black surface was investigated using low-pressure nitrogen adsorption. All these techniques yield information on the graphitic character of the surface. In general, the electrical conductivity of the conductive blacks increases with the graphitic character of the surface. For low surface area conductive blacks, the electrical conductivity correlates well with the surface chemistry. In the case of the XPS and SIMS data, this correlation is also valid when other types of carbon blacks such as thermal and furnace blacks are included, confirming the determining influence of the carbon black surface chemistry on the electrical conductivity

  7. Black carbon or brown carbon? The nature of light-absorbing carbonaceous aerosols

    Directory of Open Access Journals (Sweden)

    M. O. Andreae

    2006-01-01

    Full Text Available Although the definition and measurement techniques for atmospheric 'black carbon' ('BC' or 'elemental carbon'' ('EC' have long been subjects of scientific controversy, the recent discovery of light-absorbing carbon that is not black ('brown carbon, Cbrown' makes it imperative to reassess and redefine the components that make up light-absorbing carbonaceous matter (LAC in the atmosphere. Evidence for the atmospheric presence of Cbrown comes from (1 spectral aerosol light absorption measurements near specific combustion sources, (2 observations of spectral properties of water extracts of continental aerosol, (3 laboratory studies indicating the formation of light-absorbing organic matter in the atmosphere, and (4 indirectly from the chemical analogy of aerosol species to colored natural humic substances. We show that brown carbon may severely bias measurements of 'BC' and 'EC' over vast parts of the troposphere, especially those strongly polluted by biomass burning, where the mass concentration of Cbrown is high relative to that of soot carbon. Chemical measurements to determine 'EC' are biased by the refractory nature of Cbrown as well as by complex matrix interferences. Optical measurements of 'BC' suffer from a number of problems: (1 many of the presently used instruments introduce a substantial bias into the determination of aerosol light absorption, (2 there is no unique conversion factor between light absorption and 'EC' or 'BC' concentration in ambient aerosols, and (3 the difference in spectral properties between the different types of LAC, as well as the chemical complexity of Cbrown, lead to several conceptual as well as practical complications. We also suggest that due to the sharply increasing absorption of Cbrown towards the UV, single-wavelength light absorption measurements may not be adequate for the assessment of absorption of solar radiation in the troposphere. We discuss the possible consequences of these effects for our

  8. Snow darkening caused by black carbon emitted from fires

    Science.gov (United States)

    Engels, Jessica; Kloster, Silvia; Bourgeois, Quentin

    2014-05-01

    We implemented the effect of snow darkening caused by black carbon (BC) emitted from forest fires into the Max Planck Institute for Meteorology Earth System Model (MPI-M ESM) to estimate its potential climate impact of present day fire occurrence. Considerable amounts of black carbon emitted from fires are transported into snow covered regions. Already very small quantities of black carbon reduce the snow reflectance, with consequences for snow melting and snow spatial coverage. Therefore, the SNICAR (SNow And Ice Radiation) model (Flanner and Zender (2005)) is implemented in the land surface component (JSBACH) of the atmospheric general circulation model ECHAM6, developed at the MPI-M. The SNICAR model includes amongst other processes a complex calculation of the snow albedo depending on black carbon in snow and snow grain growth depending on water vapor fluxes for a five layer snow scheme. For the implementation of the SNICAR model into the one layer scheme of ECHAM6-JSBACH, we used the SNICAR-online version (http://snow.engin.umich.edu). This single-layer simulator provides the albedo of snow for selectable combinations of impurity content (e.g. black carbon), snow grain size, and incident solar flux characteristics. From this scheme we derived snow albedo values for black carbon in snow concentrations ranging between 0 and 1500 ng(BC)/g(snow) and for different snow grain sizes for the visible (0.3 - 0.7 µm) and near infrared range (0.7 - 1.5 µm). As snow grains grow over time, we assign different snow ages to different snow grain sizes (50, 150, 500, and 1000 µm). Here, a radius of 50 µm corresponds to new snow, whereas a radius of 1000 µm corresponds to old snow. The required snow age is taken from the BATS (Biosphere Atmosphere Transfer Scheme, Dickinson et al. (1986)) snow albedo implementation in ECHAM6-JSBACH. Here, we will present an extended evaluation of the model including a comparison of modeled black carbon in snow concentrations to observed

  9. Net removal of dissolved organic carbon in the anoxic waters of the Black Sea

    NARCIS (Netherlands)

    Margolin, A.R.; Gerringa, L.J.A.; Hansell, D.A.; Rijkenberg, M.J.A.

    2016-01-01

    Dissolved organic carbon (DOC) concentrations in the deep Black Sea are ~2.5 times higher than found in the globalocean. The two major external sources of DOC are rivers and the Sea of Marmara, a transit point for waters from theMediterranean Sea. In addition, expansive phytoplankton blooms

  10. Hydrogen production using thermocatalytic decomposition of methane on Ni30/activated carbon and Ni30/carbon black.

    Science.gov (United States)

    Srilatha, K; Viditha, V; Srinivasulu, D; Ramakrishna, S U B; Himabindu, V

    2016-05-01

    Hydrogen is an energy carrier of the future need. It could be produced from different sources and used for power generation or as a transport fuel which mainly in association with fuel cells. The primary challenge for hydrogen production is reducing the cost of production technologies to make the resulting hydrogen cost competitive with conventional fuels. Thermocatalytic decomposition (TCD) of methane is one of the most advantageous processes, which will meet the future demand, hence an attractive route for COx free environment. The present study deals with the production of hydrogen with 30 wt% of Ni impregnated in commercially available activated carbon and carbon black catalysts (samples coded as Ni30/AC and Ni30/CB, respectively). These combined catalysts were not attempted by previous studies. Pure form of hydrogen is produced at 850 °C and volume hourly space velocity (VHSV) of 1.62 L/h g on the activity of both the catalysts. The analysis (X-ray diffraction (XRD)) of the catalysts reveals moderately crystalline peaks of Ni, which might be responsible for the increase in catalytic life along with formation of carbon fibers. The activity of carbon black is sustainable for a longer time compared to that of activated carbon which has been confirmed by life time studies (850 °C and 54 sccm of methane).

  11. Evaluation of various carbon blacks and dispersing agents for use in the preparation of uranium microspheres with carbon

    Science.gov (United States)

    Hunt, R. D.; Johnson, J. A.; Collins, J. L.; McMurray, J. W.; Reif, T. J.; Brown, D. R.

    2018-01-01

    A comparison study on carbon blacks and dispersing agents was performed to determine their impacts on the final properties of uranium fuel kernels with carbon. The main target compositions in this internal gelation study were 10 and 20 mol % uranium dicarbide (UC2), which is UC1.86, with the balance uranium dioxide. After heat treatment at 1900 K in flowing carbon monoxide in argon for 12 h, the density of the kernels produced using a X-energy proprietary carbon suspension, which is commercially available, ranged from 96% to 100% of theoretical density (TD), with full conversion of UC to UC2 at both carbon concentrations. However, higher carbon concentrations such as a 2.5 mol ratio of carbon to uranium in the feed solutions failed to produce gel spheres with the proprietary carbon suspension. The kernels using our former baseline of Mogul L carbon black and Tamol SN were 90-92% of TD with full conversion of UC to UC2 at a variety of carbon levels. Raven 5000 carbon black and Tamol SN were used to produce 10 mol % UC2 kernels with 95% of TD. However, an increase in the Raven 5000 concentration led to a kernel density below 90% of TD. Raven 3500 carbon black and Tamol SN were used to make very dense kernels without complete conversion to UC2. The selection of the carbon black and dispersing agent is highly dependent on the desired final properties of the target kernels.

  12. Correlation between rheological and mechanical properties of black PE100 compounds – Effect of carbon black masterbatch

    Directory of Open Access Journals (Sweden)

    G. Pircheraghi

    2017-08-01

    Full Text Available Black PE100 compounds were prepared using a co-rotating twin screw extruder by addition of carbon black masterbatches containing 35–40 wt% carbon black and different polymer carriers to a pipe grade PE100 material with bimodal molecular weight distribution. Different properties of carbon black masterbatches and PE100 black compounds were evaluated using thermal, rheological and mechanical tests. Rheological results indicated an inverse correlation between melt flow index (MFI of masterbatch samples and storage modulus, complex viscosity and shear viscosity of black compounds, while flow instabilities of compounds were also postponed to higher shear rates. TGA indicated that masterbatch with highest value of MFI contained highest amount of low molecular weight lubricants which resulted in inhibition of strain hardening behavior in tensile test of its respective black compound unlike all other samples, reflecting possible suppressing of its long term resistance to slow crack growth. This behavior is attributable to facilitated crystallization and chain folding of longer chains in the presence of low molecular weight lubricants in this sample and consequently formation of thicker lamellas as confirmed by DSC, hence lowering density of entanglements in amorphous area and inhibition of strain hardening.

  13. Studies of activated carbon and carbon black for supercapacitor applications

    Energy Technology Data Exchange (ETDEWEB)

    Richner, R; Mueller, S; Koetz, R; Wokaun, A [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Carbon Black and activated carbon materials providing high surface areas and a distinct pore distribution are prime materials for supercapacitor applications at frequencies < 0.5 Hz. A number of these materials were tested for their specific capacitance, surface and pore size distribution. High capacitance electrodes were manufactured on the laboratory scale with attention to ease of processability. (author) 1 fig., 1 ref.

  14. Sensitive method for dosing carboxylic functions of carbons and its application to the study of thermally processed carbon blacks

    International Nuclear Information System (INIS)

    Bernardin, Jacques

    1968-01-01

    This research thesis reports the development of a sensitive method for the dosing of carboxylic functions present at the surface of carbon blacks, and the use of this method to study the evolution of a carbon black during heat treatments. After a brief description of modes of fabrication of carbon blacks and of their structure, the author proposes an overview of knowledge on their oxidation and functional analysis. After having outlined that existing methods do not allow the measurement of function quantities less than ten micro-equivalent per gram of carbon, the author reports the development of a method which allows such measurements. By using this method, the author shows that carboxylic groups of a carbon black, oxidized by air or not, decompose during degassing by forming carbon dioxide, and that, reciprocally, the released carbon dioxide is exclusively produced by the decomposition of carboxylic groups [fr

  15. Black carbon concentration and deposition estimations in Finland by the regional aerosol–climate model REMO-HAM

    Directory of Open Access Journals (Sweden)

    A. I. Hienola

    2013-04-01

    Full Text Available The prediction skill of the regional aerosol–climate model REMO-HAM was assessed against the black carbon (BC concentration measurements from five locations in Finland, with focus on Hyytiälä station for the year 2005. We examined to what extent the model is able to reproduce the measurements using several statistical tools: median comparison, overlap coefficient (OVL; the common area under two probability distributions curves and Z score (a measure of standard deviation, shape and spread of the distributions. The results of the statistics showed that the model is biased low. The local and regional emissions of BC have a significant contribution, and the model tendency to flatten the observed BC is most likely dominated by the lack of domestic burning of biofuel in the emission inventories. A further examination of the precipitation data from both measurements and model showed that there is no correlation between REMO's excessive precipitation and BC underestimation. This suggests that the excessive wet removal is not the main cause of the low black carbon concentration output. In addition, a comparison of wind directions in relation with high black carbon concentrations shows that REMO-HAM is able to predict the BC source directions relatively well. Cumulative black carbon deposition fluxes over Finland were estimated, including the deposition on snow.

  16. 20th-Century Industrial Black Carbon Emissions Altered Arctic Climate Forcing

    OpenAIRE

    McConnell, J. R; Edwards, R.; Kok, G. L; Flanner, M. G; Zender, C. S; Saltzman, E. S; Banta, J. R; Pasteris, D. R; Carter, M. M; Kahl, J. D. W

    2007-01-01

    Black carbon (BC) from biomass and fossil fuel combustion alters chemical and physical properties of the atmosphere and snow albedo, yet little is known about its emission or deposition histories. Measurements of BC, vanillic acid, and non–sea-salt sulfur in ice cores indicate that sources and concentrations of BC in Greenland precipitation varied greatly since 1788 as a result of boreal forest fires and industrial activities. Beginning about 1850, industrial emissions resulted in a sevenfold...

  17. Black carbon emissions in Russia: A critical review

    Science.gov (United States)

    Evans, Meredydd; Kholod, Nazar; Kuklinski, Teresa; Denysenko, Artur; Smith, Steven J.; Staniszewski, Aaron; Hao, Wei Min; Liu, Liang; Bond, Tami C.

    2017-08-01

    This study presents a comprehensive review of estimated black carbon (BC) emissions in Russia from a range of studies. Russia has an important role regarding BC emissions given the extent of its territory above the Arctic Circle, where BC emissions have a particularly pronounced effect on the climate. We assess underlying methodologies and data sources for each major emissions source based on their level of detail, accuracy and extent to which they represent current conditions. We then present reference values for each major emissions source. In the case of flaring, the study presents new estimates drawing on data on Russia's associated petroleum gas and the most recent satellite data on flaring. We also present estimates of organic carbon (OC) for each source, either based on the reference studies or from our own calculations. In addition, the study provides uncertainty estimates for each source. Total BC emissions are estimated at 688 Gg in 2014, with an uncertainty range 401 Gg-1453 Gg, while OC emissions are 9224 Gg with uncertainty ranging between 5596 Gg and 14,736 Gg. Wildfires dominated and contributed about 83% of the total BC emissions: however, the effect on radiative forcing is mitigated in part by OC emissions. We also present an adjusted estimate of Arctic forcing from Russia's BC and OC emissions. In recent years, Russia has pursued policies to reduce flaring and limit particulate emissions from on-road transport, both of which appear to significantly contribute to the lower emissions and forcing values found in this study.

  18. Quantifying the potential for low-level transport of black carbon emissions from cropland burning in Russia to the snow-covered Arctic.

    Science.gov (United States)

    Hall, Joanne V.; Loboda, Tatiana V.

    2017-12-01

    Short-lived aerosols and pollutants transported from northern mid-latitudes have amplified the short term warming in the Arctic region. Among those black carbon is recognized as the second most important human emission in regards to climate forcing, behind carbon dioxide, with a total climate forcing of +1.1Wm-2. Studies have suggested that cropland burning may be a large contributor to the black carbon emissions which are directly deposited on the snow in the Arctic. However, commonly applied atmospheric transport models rely on estimates of black carbon emissions from cropland burning which are known to be highly inaccurate in both the amount and the timing of release. Instead, this study quantifies the potential for the deposition of hypothetical black carbon emissions from known cropland burning in Russia, identified by the Moderate Resolution Imaging Spectroradiometer (MODIS) active fire detections, through low-level transport to the snow in the Arctic using wind vectors from the European Centre for Medium-Range Weather Forecasts’ ERA-Interim Reanalysis product. Our results confirm that Russian cropland burning is a potentially significant source of black carbon deposition on the Arctic snow in the spring despite the low injection heights associated with cropland burning. Approximately 10% of the observed spring (March - May) cropland active fires (7% annual) likely contribute to black carbon deposition on the Arctic snow from as far south as at least 40°N. Furthermore, our results show that potential spring black carbon emissions from cropland burning in Russia can be deposited beyond 80°N, however, the majority ( 90% - depending on injection height) of all potential spring deposition occurs below 75°N.

  19. Quantifying the Potential for Low-Level Transport of Black Carbon Emissions from Cropland Burning in Russia to the Snow-Covered Arctic

    Directory of Open Access Journals (Sweden)

    Joanne V. Hall

    2017-12-01

    Full Text Available Short lived aerosols and pollutants transported from northern mid-latitudes have amplified the short term warming in the Arctic region. Among those black carbon is recognized as the second most important human emission in regards to climate forcing, behind carbon dioxide, with a total climate forcing of +1.1 Wm−2. Studies have suggested that cropland burning may be a large contributor to the black carbon emissions which are directly deposited on the snow in the Arctic. However, commonly applied atmospheric transport models rely on estimates of black carbon emissions from cropland burning which are known to be highly inaccurate in both the amount and the timing of release. Instead, this study quantifies the potential for the deposition of hypothetical black carbon emissions from known cropland burning in Russia, identified by the Moderate Resolution Imaging Spectroradiometer (MODIS active fire detections, through low-level transport to the snow in the Arctic using wind vectors from the European Centre for Medium-Range Weather Forecasts' ERA-Interim Reanalysis product. Our results confirm that Russian cropland burning is a potentially significant source of black carbon deposition on the Arctic snow in the spring despite the low injection heights associated with cropland burning. Approximately 10% of the observed spring (March–May cropland active fires (7% annual likely contribute to black carbon deposition on the Arctic snow from as far south as at least 40°N. Furthermore, our results show that potential spring black carbon emissions from cropland burning in Russia can be deposited beyond 80°N, however, the majority (~90%-depending on injection height of all potential spring deposition occurs below 75°N.

  20. Source apportionment of organic pollutants of a highway-traffic-influenced urban area in Bayreuth (Germany) using biomarker and stable carbon isotope signatures.

    Science.gov (United States)

    Glaser, Bruno; Dreyer, Annekatrin; Bock, Michael; Fiedler, Stefan; Mehring, Marion; Heitmann, Tobias

    2005-06-01

    Traffic- and urban-influenced areas are prone to enhanced pollution with products of incomplete combustion of fossil fuels and biomass such as black carbon or polycyclic aromatic hydrocarbons (PAHs). Black carbon is composed of aromatic and graphitic structures and may act as a carrier for pollutants such as PAHs and heavy metals. However, little is known about possible contributions of traffic-derived black carbon to the black carbon inventory in soils. Similar uncertainties exist regarding the contribution of different pollutant sources to total PAH and black carbon contents. Therefore, the objective of this study was to quantify the importance of traffic pollution to black carbon and PAH inventories in soils. PAH contamination of soils adjacent to a major German highway in the urban area of Bayreuth with about 50,000 vehicles per day was in the same order of magnitude compared to highway-close soils reported in other studies. Using molecular (black carbon and PAHs) and compound-specific stable carbon isotope evidence (PAHs) it was demonstrated that this contamination originated not only from automobile exhausts, here primarily diesel, but also from tire abrasion and tailpipe soot which significantly contributed to the traffic-caused black carbon and PAH contamination. Low molecular weight PAHs were more widely transported than their heavy molecular counterparts (local distillation), whereas highway-traffic-caused black carbon contamination was distributed to at least 30 m from the highway. On the other hand, urban fire exhausts were distributed more homogeneously among the urban area.

  1. An improved method for quantitatively measuring the sequences of total organic carbon and black carbon in marine sediment cores

    Science.gov (United States)

    Xu, Xiaoming; Zhu, Qing; Zhou, Qianzhi; Liu, Jinzhong; Yuan, Jianping; Wang, Jianghai

    2018-01-01

    Understanding global carbon cycle is critical to uncover the mechanisms of global warming and remediate its adverse effects on human activities. Organic carbon in marine sediments is an indispensable part of the global carbon reservoir in global carbon cycling. Evaluating such a reservoir calls for quantitative studies of marine carbon burial, which closely depend on quantifying total organic carbon and black carbon in marine sediment cores and subsequently on obtaining their high-resolution temporal sequences. However, the conventional methods for detecting the contents of total organic carbon or black carbon cannot resolve the following specific difficulties, i.e., (1) a very limited amount of each subsample versus the diverse analytical items, (2) a low and fluctuating recovery rate of total organic carbon or black carbon versus the reproducibility of carbon data, and (3) a large number of subsamples versus the rapid batch measurements. In this work, (i) adopting the customized disposable ceramic crucibles with the microporecontrolled ability, (ii) developing self-made or customized facilities for the procedures of acidification and chemothermal oxidization, and (iii) optimizing procedures and carbon-sulfur analyzer, we have built a novel Wang-Xu-Yuan method (the WXY method) for measuring the contents of total organic carbon or black carbon in marine sediment cores, which includes the procedures of pretreatment, weighing, acidification, chemothermal oxidation and quantification; and can fully meet the requirements of establishing their highresolution temporal sequences, whatever in the recovery, experimental efficiency, accuracy and reliability of the measurements, and homogeneity of samples. In particular, the usage of disposable ceramic crucibles leads to evidently simplify the experimental scenario, which further results in the very high recovery rates for total organic carbon and black carbon. This new technique may provide a significant support for

  2. Ambient measurements and source apportionment of fossil fuel and biomass burning black carbon in Ontario

    Science.gov (United States)

    Healy, R. M.; Sofowote, U.; Su, Y.; Debosz, J.; Noble, M.; Jeong, C.-H.; Wang, J. M.; Hilker, N.; Evans, G. J.; Doerksen, G.; Jones, K.; Munoz, A.

    2017-07-01

    Black carbon (BC) is of significant interest from a human exposure perspective but also due to its impacts as a short-lived climate pollutant. In this study, sources of BC influencing air quality in Ontario, Canada were investigated using nine concurrent Aethalometer datasets collected between June 2015 and May 2016. The sampling sites represent a mix of background and near-road locations. An optical model was used to estimate the relative contributions of fossil fuel combustion and biomass burning to ambient concentrations of BC at every site. The highest annual mean BC concentration was observed at a Toronto highway site, where vehicular traffic was found to be the dominant source. Fossil fuel combustion was the dominant contributor to ambient BC at all sites in every season, while the highest seasonal biomass burning mass contribution (35%) was observed in the winter at a background site with minimal traffic contributions. The mass absorption cross-section of BC was also investigated at two sites, where concurrent thermal/optical elemental carbon data were available, and was found to be similar at both locations. These results are expected to be useful for comparing the optical properties of BC at other near-road environments globally. A strong seasonal dependence was observed for fossil fuel BC at every Ontario site, with mean summer mass concentrations higher than their respective mean winter mass concentrations by up to a factor of two. An increased influence from transboundary fossil fuel BC emissions originating in Michigan, Ohio, Pennsylvania and New York was identified for the summer months. The findings reported here indicate that BC should not be considered as an exclusively local pollutant in future air quality policy decisions. The highest seasonal difference was observed at the highway site, however, suggesting that changes in fuel composition may also play an important role in the seasonality of BC mass concentrations in the near-road environment

  3. Evaluating The Performance of Asphalt Concrete Mixes by Utilizing Carbon Black as Asphalt Modifier

    Directory of Open Access Journals (Sweden)

    Aliaa Faleh Al.ani

    2018-02-01

    Full Text Available Carbon black produced from several factories in Iraq is expected to provide a reinforcing agent for asphalt paving materials. Carbon black has many characteristics that distinguish  it from conventional mineral fillers, as well as their different function in pavement mixtures. Theory and exercise advanced  in the inclusive utilize of carbon black as a reinforcing agent for rubber has led to concept of asphalt reinforcement. The very fine particles of micro filler added in different contents will be dispersed in asphalt cement improving the mechanical properties of asphalt concrete mixes. In this Four percentages rates were utilized; 0, 3, 6, and 9 percent adding to asphalt grade (60-70. Mixes of asphalt concrete were destined at their optimum asphalt content (OAC then experienced to assess their engineering characteristics that contain moisture of damage, permanent deformation, modulus of resilient and characteristics of fatigue. These characteristics have been assessed utilizing indirect tensile strength, uniaxial repeated loading and repeated flexural beam tests. Mixtures improved with carbon black were existed to have amended permanent deformation and fatigue characteristics, else exhibited high resilient modulus and lower moisture susceptibility. Result showed that a rate changed from 3 to 9 percent has shown an increase in resilient modulus for increment of carbon black and modulus of resilient for mixes with 9 percent carbon black was 1.4 times that for mixes with 0 percent carbon black. The altering of carbon black from a range (3-9 percent has modified the fatigue property of the asphalt concrete mixes as determined by flexural test, Significantly, to modify the asphalt concrete manner taken the  percent of carbon black 6, and to produce the mixes more durable , higher resistance to distresses by adding the local knowledge.

  4. Global emission inventory and atmospheric transport of black carbon. Evaluation of the associated exposure

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Rong

    2015-06-01

    This thesis presents research focusing on the improvement of high-resolution global black carbon (BC) emission inventory and application in assessing the population exposure to ambient BC. A particular focus of the thesis is on the construction of a high-resolution (both spatial and sectorial) fuel consumption database, which is used to develop the emission inventory of black carbon. Above all, the author updates the global emission inventory of black carbon, a resource subsequently used to study the atmospheric transport of black carbon over Asia with the help of a high-resolution nested model. The thesis demonstrates that spatial bias in fuel consumption and BC emissions can be reduced by means of the sub-national disaggregation approach. Using the inventory and nested model, ambient BC concentrations can be better validated against observations. Lastly, it provides a complete uncertainty analysis of global black carbon emissions, and this uncertainty is taken into account in the atmospheric modeling, helping to better understand the role of black carbon in regional and global air pollution.

  5. Seasonal features of black carbon measured at Syowa Station, Antarctica

    Science.gov (United States)

    Hara, K.; Osada, K.; Yabuki, M.; Shiobara, M.; Yamanouchi, T.

    2015-12-01

    Black carbon (BC) is one of important aerosol constituents because the strong light absorption ability. Low concentrations of aerosols and BC let BC make insignificant contribution to aerosol radiative forcing in the Antarctica at the moment. Because of less or negligible source strength of BC in the Antarctic circle, BC can be used as a tracer of transport from the mid-latitudes. This study aims to understand seasonal feature, transport pathway, and origins of black carbon in the Antarctic coats. Black carbon measurement has been made using 7-wavelength aethalometer at Syowa Station, Antarctica since February, 2005. Mass BC concentrations were estimated from light attenuation by Weingartner's correction procedure (Weingartner et al., 2003) in this study. Detection limit was 0.2 - 0.4 ng/m3 in our measurement conditions (2-hour resolution and flow rate of ca. 10LPM). BC concentrations ranged from near detection limit to 55.7 ng/m3 at Syowa Station, Antarctica during the measurements. No trend has been observed since February, 2005. High BC concentrations were coincident with poleward flow from the mid-latitudes under the storm conditions by cyclone approach, whereas low BC concentrations were found in transport from coastal regions and the Antarctic continent. Considering that outflow from South America and Southern Africa affect remarkably air quality in the Southern Ocean of Atlantic and Indian Ocean sectors, BC at Syowa Station might be originated from biomass burning and human activity on South America and Southern Africa. Seasonal features of BC at Syowa Station shows maximum in September - October and lower in December - April. Spring maximum in September - October was obtained at the other Antarctic stations (Neumayer, Halley, South pole, and Ferraz). Although second maximum was found in January at the other stations, the maximum was not observed at Syowa Station.

  6. Black carbon concentrations and sources in the marine boundary layer of the tropical Atlantic Ocean using four methodologies

    Science.gov (United States)

    Combustion-derived aerosols in the marine boundary layer have been poorly studied, especially in remote environments such as the open Atlantic Ocean. The tropical Atlantic has the potential to contain a high concentration of aerosols, such as black carbon, due to the African emis...

  7. Global anthropogenic emissions of particulate matter including black carbon

    Science.gov (United States)

    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

  8. Global anthropogenic emissions of particulate matter including black carbon

    Directory of Open Access Journals (Sweden)

    Z. Klimont

    2017-07-01

    Full Text Available 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

  9. Enhancement of micropore filling of water on carbon black by platinum loading

    Energy Technology Data Exchange (ETDEWEB)

    Miyajima, Naoya, E-mail: miyajima@yamanashi.ac.jp [Interdisciplinary Graduate School of Medicine and Engineering, 4-3-11 Takeda, Kofu, Yamanashi 400-8511 (Japan); Hatori, Hiroaki [Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki 305-8569 (Japan); Radovic, Ljubisa R. [Department of Energy and Geo-Environmental Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Yamada, Yoshio [Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki 305-8569 (Japan)

    2010-10-15

    Two kinds of typical carbons, carbon black and activated carbon fibers, were modified with platinum nanoparticles without changing their original pore structures. The surface properties of the modified carbons were investigated by measuring of water adsorption isotherms. Micropore filling of water was facilitated by the presence of platinum nanoparticles on the surface of the carbon black. On the other hand, such a filling effect was not observed in the case of the activated carbon fibers. A critical content and/or size of platinum nanoparticles could be required to promote efficiently the water adsorption.

  10. 40 CFR 458.45 - Standards of performance for new sources.

    Science.gov (United States)

    2010-07-01

    ... paragraph, which may be discharged from the carbon black lamp process by a new source subject to the provisions of this subpart: There shall be no discharge of process waste water pollutants to navigable waters. ...) EFFLUENT GUIDELINES AND STANDARDS CARBON BLACK MANUFACTURING POINT SOURCE CATEGORY Carbon Black Lamp...

  11. Plasma polymerization surface modification of Carbon black and its effect in elastomers

    NARCIS (Netherlands)

    Mathew, T.; Datta, Rabin; Dierkes, Wilma K.; Talma, Auke; Ooij, W.J.; Noordermeer, Jacobus W.M.

    2011-01-01

    Surface modification of carbon black by plasma polymerization was aimed to reduce its surface energy in order to compatibilize the filler with various elastomers. A fullerenic carbon black was used for the modification process. Thermogravimetric analysis, wetting behavior with liquids of known

  12. Distribution and Sources of Black Carbon in the Arctic

    Science.gov (United States)

    Qi, Ling

    The Arctic is warming at twice the global rate over recent decades. To slow down this warming trend, there is growing interest in reducing the impact from short-lived climate forcers, such as black carbon (BC), because the benefits of mitigation are seen more quickly relative to CO2 reduction. To propose efficient mitigation policies, it is imperative to improve our understanding of BC distribution in the Arctic and to identify the sources. In this dissertation, we investigate the sensitivity of BC in the Arctic, including BC concentrations in snow (BCsnow) and BC concentrations in air (BCair), to emissions, dry deposition and wet scavenging using a global 3-D chemical transport model (CTM) GEOS-Chem. By including flaring emissions, estimating dry deposition velocity using resistance-in-series method, and including Wegener-Bergeron-Findeisen (WBF) in wet scavenging, simulated BCsnow in the eight Arctic sub-regions agree with the observations within a factor of two, and simulated BCair fall within the uncertainty range of observations. Specifically, we find that natural gas flaring emissions in Western Extreme North of Russia (WENR) strongly enhance BCsnow (by up to ?50%) and BCair (by 20-32%) during snow season in the so-called 'Arctic front', but has negligible impact on BC in the free troposphere. The updated dry deposition velocity over snow and ice is much larger than those used in most of global CTMs and agrees better with observation. The resulting BCsnow changes marginally because of the offsetting of higher dry and lower wet deposition fluxes. In contrast, surface BCair decreases strongly due to the faster dry deposition (by 27-68%). WBF occurs when the environmental vapor pressure is in between the saturation vapor pressure of ice crystals and water drops in mixed-phase clouds. As a result, water drops evaporate and releases BC particles in them back into the interstitial air. In most CTMs, WBF is either missing or represented by a uniform and low BC

  13. Thermal Oxidation of Tail Gases from the Production of Oil-furnace Carbon Black

    Directory of Open Access Journals (Sweden)

    Bosak, Z.

    2009-01-01

    Full Text Available This paper describes the production technology of oil-furnace carbon black, as well as the selected solution for preventing the emissions of this process from contaminating the environment.The products of industrial oil-furnace carbon black production are different grades of carbon black and process tail gases. The qualitative composition of these tail gases during the production of oil-furnace carbon black are: carbon(IV oxide, carbon(II oxide, hydrogen, methane, hydrogen sulfide, nitrogen, oxygen, and water vapor.The quantitative composition and lower caloric value of process tail gases change depending on the type of feedstock used in the production, as well as the type of process. The lower caloric value of process tail gases is relatively small with values ranging between 1500 and 2300 kJ m–3.In the conventional production of oil-furnace carbon black, process tail gases purified from carbon black dust are freely released into the atmosphere untreated. In this manner, the process tail gases pollute the air in the town of Kutina, because their quantitative values are much higher than the prescribed emissions limits for hydrogen sulfide and carbon(II oxide. A logical solution for the prevention of such air pollution is combustion of the process tail gases, i. e. their thermal oxidation. For this purpose, a specially designed flare system has been developed. Consuming minimum amounts of natural gas needed for oxidation, the flare system is designed to combust low caloric process tail gases with 99 % efficiency. Thus, the toxic and flammable components of the tail gases (hydrogen sulfide, hydrogen, carbon(II oxide, methane and other trace hydrocarbons would be transformed into environmentally acceptable components (sulfur(IV oxide, water, carbon(IV oxide and nitrogen(IV oxide, which are in compliance with the emissions limit values prescribed by law.Proper operation of this flare system in the production of oil-furnace carbon black would solve

  14. Automatic Method for Controlling the Iodine Adsorption Number in Carbon Black Oil Furnaces

    Directory of Open Access Journals (Sweden)

    Zečević, N.

    2008-12-01

    Full Text Available There are numerous of different inlet process factors in carbon black oil furnaces which must be continuously and automatically adjusted, due to stable quality of final product. The most important six inlet process factors in carbon black oil-furnaces are:1. volume flow of process air for combustion2. temperature of process air for combustion3. volume flow of natural gas for insurance the necessary heat for thermal reaction of conversionthe hydrocarbon oil feedstock in oil-furnace carbon black4. mass flow rate of hydrocarbon oil feedstock5. type and quantity of additive for adjustment the structure of oil-furnace carbon black6. quantity and position of the quench water for cooling the reaction of oil-furnace carbon black.The control of oil-furnace carbon black adsorption capacity is made with mass flow rate of hydrocarbon feedstock, which is the most important inlet process factor. Oil-furnace carbon black adsorption capacity in industrial process is determined with laboratory analyze of iodine adsorption number. It is shown continuously and automatically method for controlling iodine adsorption number in carbon black oil-furnaces to get as much as possible efficient control of adsorption capacity. In the proposed method it can be seen the correlation between qualitatively-quantitatively composition of the process tail gasses in the production of oil-furnace carbon black and relationship between air for combustion and hydrocarbon feedstock. It is shown that the ratio between air for combustion and hydrocarbon oil feedstock is depended of adsorption capacity summarized by iodine adsorption number, regarding to BMCI index of hydrocarbon oil feedstock.The mentioned correlation can be seen through the figures from 1. to 4. From the whole composition of the process tail gasses the best correlation for continuously and automatically control of iodine adsorption number is show the volume fraction of methane. The volume fraction of methane in the

  15. Stormwater and fire as sources of black carbon nanoparticles to Lake Tahoe.

    Science.gov (United States)

    Bisiaux, Marion M; Edwards, Ross; Heyvaert, Alan C; Thomas, James M; Fitzgerald, Brian; Susfalk, Richard B; Schladow, S Geoffrey; Thaw, Melissa

    2011-03-15

    Emitted to the atmosphere through fire and fossil fuel combustion, refractory black carbon nanoparticles (rBC) impact human health, climate, and the carbon cycle. Eventually these particles enter aquatic environments, where they may affect the fate of other pollutants. While ubiquitous, the particles are still poorly characterized in freshwater systems. Here we present the results of a study determining rBC in waters of the Lake Tahoe watershed in the western United States from 2007 to 2009. The study period spanned a large fire within the Tahoe basin, seasonal snowmelt, and a number of storm events, which resulted in pulses of urban runoff into the lake with rBC concentrations up to 4 orders of magnitude higher than midlake concentrations. The results show that rBC pulses from both the fire and urban runoff were rapidly attenuated suggesting unexpected aggregation or degradation of the particles. We find that those processes prevent rBC concentrations from building up in the clear and oligotrophic Lake Tahoe. This rapid removal of rBC soon after entry into the lake has implications for the transport of rBC in the global aquatic environment and the flux of rBC from continents to the global ocean.

  16. Adsorption of Remazol Black B dye on Activated Carbon Felt

    Directory of Open Access Journals (Sweden)

    Donnaperna Lucio

    2008-11-01

    Full Text Available The adsorption of Remazol Black B (anionic dye on a microporous activated carbon felt is investigated from its aqueous solution. The surface chemistry of activated carbon is studied using X-ray microanalysis, "Boehm" titrations and pH of PZC measurements which indicates that the surface oxygenated groups are mainly acidic in nature. The kinetics of Remazol Black B adsorption is observed to be pH dependent and governed by the diffusion of the dye molecules. The experimental data can be explained by "intra-particle diffusion model". For Remazol Black B, the Khan model is best suited to simulate the adsorption isotherms.

  17. Electrical conductivity of compacts of graphene, multi-wall carbon nanotubes, carbon black, and graphite powder

    NARCIS (Netherlands)

    Marinho, B.; Gomes Ghislandi, M.; Tkalya, E.; Koning, C.E.; With, de G.

    2012-01-01

    The electrical conductivity of different carbon materials (multi-walled carbon nanotubes, graphene, carbon black and graphite), widely used as fillers in polymeric matrices, was studied using compacts produced by a paper preparation process and by powder compression. Powder pressing assays show that

  18. Comparative inhalation toxicity of multi-wall carbon nanotubes, graphene, graphite nanoplatelets and low surface carbon black.

    Science.gov (United States)

    Ma-Hock, Lan; Strauss, Volker; Treumann, Silke; Küttler, Karin; Wohlleben, Wendel; Hofmann, Thomas; Gröters, Sibylle; Wiench, Karin; van Ravenzwaay, Bennard; Landsiedel, Robert

    2013-06-17

    Carbon nanotubes, graphene, graphite nanoplatelets and carbon black are seemingly chemically identical carbon-based nano-materials with broad technological applications. Carbon nanotubes and carbon black possess different inhalation toxicities, whereas little is known about graphene and graphite nanoplatelets. In order to compare the inhalation toxicity of the mentioned carbon-based nanomaterials, male Wistar rats were exposed head-nose to atmospheres of the respective materials for 6 hours per day on 5 consecutive days. Target concentrations were 0.1, 0.5, or 2.5 mg/m3 for multi-wall carbon nanotubes and 0.5, 2.5, or 10 mg/m3 for graphene, graphite nanoplatelets and low-surface carbon black. Toxicity was determined after end of exposure and after three-week recovery using broncho-alveolar lavage fluid and microscopic examinations of the entire respiratory tract. No adverse effects were observed after inhalation exposure to 10 mg/m3 graphite nanoplatelets or relatively low specific surface area carbon black. Increases of lavage markers indicative for inflammatory processes started at exposure concentration of 0.5 mg/m3 for multi-wall carbon nanotubes and 10 mg/m3 for graphene. Consistent with the changes in lavage fluid, microgranulomas were observed at 2.5 mg/m3 multi-wall carbon nanotubes and 10 mg/m3 graphene. In order to evaluate volumetric loading of the lung as the key parameter driving the toxicity, deposited particle volume was calculated, taking into account different methods to determine the agglomerate density. However, the calculated volumetric load did not correlate to the toxicity, nor did the particle surface burden of the lung. The inhalation toxicity of the investigated carbon-based materials is likely to be a complex interaction of several parameters. Until the properties which govern the toxicity are identified, testing by short-term inhalation is the best option to identify hazardous properties in order to avoid unsafe applications or select

  19. Comparative inhalation toxicity of multi-wall carbon nanotubes, graphene, graphite nanoplatelets and low surface carbon black

    Science.gov (United States)

    2013-01-01

    Background Carbon nanotubes, graphene, graphite nanoplatelets and carbon black are seemingly chemically identical carbon-based nano-materials with broad technological applications. Carbon nanotubes and carbon black possess different inhalation toxicities, whereas little is known about graphene and graphite nanoplatelets. Methods In order to compare the inhalation toxicity of the mentioned carbon-based nanomaterials, male Wistar rats were exposed head-nose to atmospheres of the respective materials for 6 hours per day on 5 consecutive days. Target concentrations were 0.1, 0.5, or 2.5 mg/m3 for multi-wall carbon nanotubes and 0.5, 2.5, or 10 mg/m3 for graphene, graphite nanoplatelets and low-surface carbon black. Toxicity was determined after end of exposure and after three-week recovery using broncho-alveolar lavage fluid and microscopic examinations of the entire respiratory tract. Results No adverse effects were observed after inhalation exposure to 10 mg/m3 graphite nanoplatelets or relatively low specific surface area carbon black. Increases of lavage markers indicative for inflammatory processes started at exposure concentration of 0.5 mg/m3 for multi-wall carbon nanotubes and 10 mg/m3 for graphene. Consistent with the changes in lavage fluid, microgranulomas were observed at 2.5 mg/m3 multi-wall carbon nanotubes and 10 mg/m3 graphene. In order to evaluate volumetric loading of the lung as the key parameter driving the toxicity, deposited particle volume was calculated, taking into account different methods to determine the agglomerate density. However, the calculated volumetric load did not correlate to the toxicity, nor did the particle surface burden of the lung. Conclusions The inhalation toxicity of the investigated carbon-based materials is likely to be a complex interaction of several parameters. Until the properties which govern the toxicity are identified, testing by short-term inhalation is the best option to identify hazardous properties in

  20. Low black carbon concentration in agricultural soils of central and northern Ethiopia.

    Science.gov (United States)

    Yli-Halla, Markku; Rimhanen, Karoliina; Muurinen, Johanna; Kaseva, Janne; Kahiluoto, Helena

    2018-08-01

    Soil carbon (C) represents the largest terrestrial carbon stock and is key for soil productivity. Major fractions of soil C consist of organic C, carbonates and black C. The turnover rate of black C is lower than that of organic C, and black C abundance decreases the vulnerablility of soil C stock to decomposition under climate change. The aim of this study was to determine the distribution of soil C in different pools and impact of agricultural management on the abundance of different species. Soil C fractions were quantified in the topsoils (0-15cm) of 23 sites in the tropical highlands of Ethiopia. The sites in central Ethiopia represented paired plots of agroforestry and adjacent control plots where cereal crops were traditionally grown in clayey soils. In the sandy loam and loam soils of northern Ethiopia, the pairs represented restrained grazing with adjacent control plots with free grazing, and terracing with cereal-based cropping with adjacent control plots without terracing. Soil C contained in carbonates, organic matter and black C along with total C was determined. The total C median was 1.5% (range 0.3-3.6%). The median proportion of organic C was 85% (range 53-94%), 6% (0-41%) for carbonate C and 6% (4-21%) for black C. An increase was observed in the organic C and black C fractions attributable to agroforestry and restrained grazing. The very low concentration of the relatively stable black C fraction and the dominance of organic C in these Ethiopian soils suggest vulnerability to degradation and the necessity for cultivation practices maintaining the C stock. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Historical record of black carbon in urban soils and its environmental implications

    International Nuclear Information System (INIS)

    He Yue; Zhang Ganlin

    2009-01-01

    Energy use in urbanization has fundamentally changed the pattern and fluxes of carbon cycling, which has global and local environmental impacts. Here we have investigated organic carbon (OC) and black carbon (BC) in six soil profiles from two contrast zones in an ancient city (Nanjing) in China. BC in soils was widely variable, from 0.22 to 32.19 g kg -1 . Its average concentration in an ancient residential area (Zone 1) was, 0.91 g kg -1 , whereas in Zone 2, an industrial and commercial area, the figure was 8.62 g kg -1 . The ratio of BC/OC ranged from 0.06 to 1.29 in soil profiles, with an average of 0.29. The vertical distribution of BC in soil is suggested to reflect the history of BC formation from burning of biomass and/or fossil fuel. BC in the surface layer of soils was mainly from traffic emission (especially from diesel vehicles). In contrast, in cultural layers BC was formed from historical coal use. The contents of BC and the ratio of BC/OC may reflect different human activities and pollution sources in the contrasting urban zones. In addition, the significant correlation of heavy metals (Cu, Pb, and Zn) with BC contents in some culture layers suggests the sorption of the metals by BC or their coexistence resulted from the coal-involved smelting. - Soil black carbon can reflect the pollution history of a city during urbanization.

  2. Incentives for small clubs of Arctic countries to limit black carbon and methane emissions

    Science.gov (United States)

    Aakre, Stine; Kallbekken, Steffen; Van Dingenen, Rita; Victor, David G.

    2018-01-01

    Although addressing climate change will ultimately require global cooperation, substantial progress may be achieved through small clubs of countries, where it is easier to forge and implement deals needed for policy coordination. Here we quantify the gains from cooperation in the Arctic region and find that nearly 90% of the potential for abating black carbon can be reached by countries acting in self-interest alone because soot, the main source of black carbon, causes severe harm to human health along with warming. Abating methane, by contrast, requires more cooperation because impacts are more diffused geographically. Well-designed clubs with as few as four members can realize more than 80% of the full group cooperation potential for reducing these pollutants. The pivotal player in every effective club is Russia—most other members of the Arctic Council, the institution most focused on advancing the collective interests of the region, offer little leverage on the problems at hand.

  3. Penelitian pengaruh campuran carbon black dan china clay terhadap sifat tegangan putus dan kekerasan karet vulkanisat

    Directory of Open Access Journals (Sweden)

    Supraptiningsih Supraptiningsih

    1999-07-01

    Full Text Available It has been done a research of the influence of mixed carbon black and hardness properties on the vulcanization of rubber. It has been made with additive of carbon black and china clay mixed, in total variation. The result is seen that total variation of carbon black and china clay not influence to tensile strength, but their interacton can do it. The hardness of vulcanization of rubber will be influence by total variation of carbon black china clay anad their interaction.

  4. Roles of black carbon on the fate of heavy metals and agrochemicals in soil

    Science.gov (United States)

    Char(coal) and other black carbon materials can comprise up to 35% of total organic carbon in US agricultural soils, and are known to strongly and often irreversibly bind contaminants including heavy metals. Black carbon has received renewed interests in recent years as a solid co-product formed du...

  5. The online measured black carbon aerosol and source orientations in the Nam Co region, Tibet.

    Science.gov (United States)

    Zhang, Xin; Ming, Jing; Li, Zhongqin; Wang, Feiteng; Zhang, Guoshuai

    2017-11-01

    Equivalent black carbon (eBC) mass concentrations were measured by an aethalometer (AE-31) in the Nam Co, central Tibet from 2010 to 2014. Different from previous filter-sampling studies (Ming et al., J Environ Sci 22(11):1748-1756, 2010; Zhao et al., Environ Sci Pollut Res 20:5827-5838, 2013), the first high-resolution online eBC measurement conducted in central Tibet is reported here, allowing to discuss the diurnal variations as well as seasonal variabilities of eBC. Average daily eBC concentration was 74 ± 50 ng/m 3 , reflecting a global background level. Meteorological conditions influenced eBC concentrations largely at seasonal scale, which are higher in February-May but lower in June-January. The highest eBC concentrations (greater than 210 ng/m 3 ) were more associated with the W and WSW winds smaller than 6 m/s. The diurnal variations of eBC showed plateaus from 10:00 to 15:00 with seasonal variations, associated with local anthropogenic activities, such as indigenous Tibetan burning animal waste and tourism traffic. The PBLHs showed a co-variance with eBC concentrations, implicating close sources. The aerosol optical depths derived from the MODIS data over the Nam Co Observatory Station (NCOS)-included sub-area (30° N-40° N, 90° E-100° E) showed significant relationship with eBC concentrations. This suggests that nearby or short-distance sources other than long-distance transported pollutants could be important contributors to eBC concentrations at the NCOS, different from the conclusions suggested by previous studies.

  6. Using an Explicit Emission Tagging Method in Global Modeling of Source-Receptor Relationships for Black Carbon in the Arctic: Variations, Sources and Transport Pathways

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hailong; Rasch, Philip J.; Easter, Richard C.; Singh, Balwinder; Zhang, Rudong; Ma, Po-Lun; Qian, Yun; Ghan, Steven J.; Beagley, Nathaniel

    2014-11-27

    We introduce an explicit emission tagging technique in the Community Atmosphere Model to quantify source-region-resolved characteristics of black carbon (BC), focusing on the Arctic. Explicit tagging of BC source regions without perturbing the emissions makes it straightforward to establish source-receptor relationships and transport pathways, providing a physically consistent and computationally efficient approach to produce a detailed characterization of the destiny of regional BC emissions and the potential for mitigation actions. Our analysis shows that the contributions of major source regions to the global BC burden are not proportional to the respective emissions due to strong region-dependent removal rates and lifetimes, while the contributions to BC direct radiative forcing show a near-linear dependence on their respective contributions to the burden. Distant sources contribute to BC in remote regions mostly in the mid- and upper troposphere, having much less impact on lower-level concentrations (and deposition) than on burden. Arctic BC concentrations, deposition and source contributions all have strong seasonal variations. Eastern Asia contributes the most to the wintertime Arctic burden. Northern Europe emissions are more important to both surface concentration and deposition in winter than in summer. The largest contribution to Arctic BC in the summer is from Northern Asia. Although local emissions contribute less than 10% to the annual mean BC burden and deposition within the Arctic, the per-emission efficiency is much higher than for major non-Arctic sources. The interannual variability (1996-2005) due to meteorology is small in annual mean BC burden and radiative forcing but is significant in yearly seasonal means over the Arctic. When a slow aging treatment of BC is introduced, the increase of BC lifetime and burden is source-dependent. Global BC forcing-per-burden efficiency also increases primarily due to changes in BC vertical distributions. The

  7. Conductive additive content balance in Li-ion battery cathodes: Commercial carbon blacks vs. in situ carbon from LiFePO{sub 4}/C composites

    Energy Technology Data Exchange (ETDEWEB)

    Palomares, Veronica; Goni, Aintzane; Muro, Izaskun Gil de; Rojo, Teofilo [Departamento de Quimica Inorganica, Universidad del Pais Vasco UPV/EHU, P.O. Box. 644, 48080, Bilbao (Spain); de Meatza, Iratxe; Bengoechea, Miguel [Energy Department, CIDETEC-IK4, P Miramon 196, Parque Tecnologico de San Sebastian, 20009, San Sebastian (Spain); Cantero, Igor [Departamento I+D+i Nuevas Tecnologias, CEGASA, Artapadura, 11, 01013 Vitoria-Gasteiz (Spain)

    2010-11-15

    Two samples of commercial conducting carbon black and the carbon generated in situ during LiFePO{sub 4}/C composite synthesis from citric acid are studied, with the aim of finding out whether carbon from the composite can fulfil the same function as carbon black in the electrode blend for a Li-ion battery. For this purpose, the carbon samples are analyzed by several techniques, such as X-ray diffraction, Raman spectroscopy, transmission electron microscopy, granulometry, BET specific area and conductivity measurements. Different cathode compositions and component proportions are tested for pellet and cast electrodes. Electrochemical results show that a moderate reduction of commercial carbon black content in both kinds of cathodes, by adding more LiFePO{sub 4}/C composite, enhanced the electrochemical behaviour by around 10%. In situ generated carbon can partially replace commercial conducting carbon black because its high specific surface probably enhances electrolyte penetration into the cathode, but it is always necessary to maintain a minimum amount of carbon black that provides better conductivity in order to obtain a good electrochemical response. (author)

  8. Characterization of black carbon in the ambient air of Agra, India: Seasonal variation and meteorological influence

    Science.gov (United States)

    Gupta, Pratima; Singh, Shalendra Pratap; Jangid, Ashok; Kumar, Ranjit

    2017-09-01

    This study characterizes the black carbon in Agra, India home to the Taj Mahal—and situated in the Indo-Gangetic basin. The mean black carbon concentration is 9.5 μg m-3 and, owing to excessive biomass/fossil fuel combustion and automobile emissions, the concentration varies considerably. Seasonally, the black carbon mass concentration is highest in winter, probably due to the increased fossil fuel consumption for heating and cooking, apart from a low boundary layer. The nocturnal peak rises prominently in winter, when the use of domestic heating is excessive. Meanwhile, the concentration is lowest during the monsoon season because of the turbulent atmospheric conditions and the process of washout by precipitation. The ratio of black carbon to brown carbon is less than unity during the entire study period, except in winter (December). This may be because that biomass combustion and diesel exhaust are major black carbon contributors in this region, while a higher ratio in winter may be due to the increased consumption of fossil fuel and wood for heating purposes. ANOVA reveals significant monthly variation in the concentration of black carbon; plus, it is negatively correlated with wind speed and temperature. A high black carbon mass concentration is observed at moderate (1-2 m s-1) wind speed, as compared to calm or turbulent atmospheric conditions.

  9. Higher Atmosphere Heating due to black carbon Over the Northern Part of India

    Science.gov (United States)

    Tiwari, S.; Singh, S., , Dr

    2017-12-01

    Light-absorbing, atmospheric particles have gained greater attention in recent years because of their direct and indirect impacts on regional and global climate. Atmospheric black carbon (BC) aerosol (also called soot particle) is a leading climate warming agent, yet uncertainties in the global direct aerosol radiative forcing remain large. Based on a year of aerosol absorption measurements at seven wavelengths, BC concentrations were investigated in Dhanbad, the coal capital of India. Coal is routinely burned for cooking and residential heat as well as in small industries. The mean daily concentrations of ultraviolet-absorbing black carbon measured at 370 nm (UVBC) and black carbon measured at 880 nm (BC) were 9.8 ± 5.7 and 6.5 ± 3.8 μg m-3, respectively. The difference between UVBC and BC, Delta-C, is an indicator of biomass or residential coal burning and averaged 3.29 ± 4.61 μg m-3. An alternative approach uses the calculation of the Angstrom Exponent (AE) to estimate the amounts of biomass/coal and traffic BC. Biomass/coal burning contributed 87% and fossil fuel combustion contributed 13% to the annual average BC concentration. In the post-monsoon season, potential source contribution function analysis showed that air masses came from the central and northwestern Indo-Gangetic Plains resulting in mean UVBC values of 10.9 μg m-3 and BC of 7.2 μg m-3. The mean winter UVBC and BC concentrations were 15.0 and 10.1 μg m-3, respectively. These highest values were largely driven by local sources under conditions of poor dispersion. The direct radiative forcing (DRF) due to UVBC and BC at the surface (SFC) and the top of the atmosphere (TOA) were calculated. The mean atmospheric heating rates due to UVBC and BC were estimated to be 1.40°K day-1 and 1.18°K day-1, respectively. This high heating rate may affect the monsoon circulation in this region.

  10. Is black carbon a better predictor of polycyclic aromatic hydrocarbon distribution in soils than total organic carbon?

    International Nuclear Information System (INIS)

    Agarwal, Tripti; Bucheli, Thomas D.

    2011-01-01

    Black carbon (BC) and total organic carbon (TOC) were quantified in the surface soils of Switzerland (N = 105) and Delhi (N = 36), India, to examine their relationships with contents of polycyclic aromatic hydrocarbons (PAH). BC content in Swiss (background) soils (N = 104) varied from 0.41 to 4.75 mg/g (median: 1.13 mg/g) and constituted 1-9% (median: 3%) of TOC. Indian (urban) soils had similar BC concentrations (0.37-2.05 mg/g, median: 1.19 mg/g), with relatively higher BC/TOC (6-23%, median: 13%). Similar to TOC, BC showed significant positive correlation with lighter PAH, but no correlation with heavier PAH in Swiss soils. In contrast, heavier PAH were significantly correlated only with BC in Delhi soils. It seems that TOC governs the distribution of PAH in organic matter rich background soils, while the proximity to emission sources is reflected by BC-PAH association in urban soils. - Light PAH correlated with TOC in background soils, whereas heavy PAH were associated with BC close to emission sources.

  11. Black Carbon Measurements From Ireland's Transboundary Network (TXB)

    Science.gov (United States)

    Spohn, T. K.; Martin, D.; O'Dowd, C. D. D.

    2017-12-01

    Black Carbon (BC) is carbonaceous aerosol formed by incomplete fossil fuel combustion. Named for its light absorbing properties, it acts to trap heat in the atmosphere, thus behaving like a greenhouse gas, and is considered a strong, short-lived climate forcer by the International Panel on Climate Change (IPCC). Carbonaceous aerosols from biomass burning (BB) such as forest fires and residential wood burning, also known as brown carbon, affect the ultra violet (UV) light absorption in the atmosphere as well. In 2016 a three node black carbon monitoring network was established in Ireland as part of a Transboundary Monitoring Network (TXB). The three sites (Mace Head, Malin Head, and Carnsore Point) are coastal locations on opposing sides of the country, and offer the opportunity to assess typical northern hemispheric background concentrations as well national and European pollution events. The instruments deployed in this network (Magee Scientific AE33) facilitate elimination of the changes in response due to `aerosol loading' effects; and a real-time calculation of the `loading compensation' parameter which offers insights into aerosol optical properties. Additionally, these instruments have an inbuilt algorithm, which estimates the difference in absorption in the ultraviolet wavelengths (mostly by brown carbon) and the near infrared wavelengths (only by black carbon).Presented here are the first results of the BC measurements from the three Irish stations, including instrument validation, seasonal variation as well as local, regional, and transboundary influences based on air mass trajectories as well as concurrent in-situ observations (meteorological parameters, particle number, and aerosol composition). A comparison of the instrumental algorithm to off-line sensitivity calculations will also be made to assess the contribution of biomass burning to BC pollution events.

  12. Multi-Sensor Constrained Time Varying Emissions Estimation of Black Carbon: Attributing Urban and Fire Sources Globally

    Science.gov (United States)

    Cohen, J. B.

    2015-12-01

    The short lifetime and heterogeneous distribution of Black Carbon (BC) in the atmosphere leads to complex impacts on radiative forcing, climate, and health, and complicates analysis of its atmospheric processing and emissions. Two recent papers have estimated the global and regional emissions of BC using advanced statistical and computational methods. One used a Kalman Filter, including data from AERONET, NOAA, and other ground-based sources, to estimate global emissions of 17.8+/-5.6 Tg BC/year (with the increase attributable to East Asia, South Asia, Southeast Asia, and Eastern Europe - all regions which have had rapid urban, industrial, and economic expansion). The second additionally used remotely sensed measurements from MISR and a variance maximizing technique, uniquely quantifying fire and urban sources in Southeast Asia, as well as their large year-to-year variability over the past 12 years, leading to increases from 10% to 150%. These new emissions products, when run through our state-of-the art modelling system of chemistry, physics, transport, removal, radiation, and climate, match 140 ground stations and satellites better in both an absolute and a temporal sense. New work now further includes trace species measurements from OMI, which are used with the variance maximizing technique to constrain the types of emissions sources. Furthermore, land-use change and fire estimation products from MODIS are also included, which provide other constraints on the temporal and spatial nature of the variations of intermittent sources like fires or new permanent sources like expanded urbanization. This talk will introduce a new, top-down constrained, weekly varying BC emissions dataset, show that it produces a better fit with observations, and draw conclusions about the sources and impacts from urbanization one hand, and fires on another hand. Results specific to the Southeast and East Asia will demonstrate inter- and intra-annual variations, such as the function of

  13. Joint measurements of black carbon and particle mass for heavy-duty diesel vehicles using a portable emission measurement system

    Science.gov (United States)

    The black carbon (BC) emitted from heavy-duty diesel vehicles(HDDVs) is an important source of urban atmospheric pollution and createsstrong climate-forcing impacts. The emission ratio of BC to totalparticle mass (PM) (i.e., BC/PM ratio) is an essential variable used toestimate t...

  14. Selection and Characterization of Carbon Black and Surfactants for Development of Small Scale Uranium Oxicarbide Kernels

    Energy Technology Data Exchange (ETDEWEB)

    Contescu, Cristian I [ORNL

    2006-01-01

    This report supports the effort for development of small scale fabrication of UCO (a mixture of UO{sub 2} and UC{sub 2}) fuel kernels for the generation IV high temperature gas reactor program. In particular, it is focused on optimization of dispersion conditions of carbon black in the broths from which carbon-containing (UO{sub 2} {center_dot} H{sub 2}O + C) gel spheres are prepared by internal gelation. The broth results from mixing a hexamethylenetetramine (HMTA) and urea solution with an acid-deficient uranyl nitrate (ADUN) solution. Carbon black, which is previously added to one or other of the components, must stay dispersed during gelation. The report provides a detailed description of characterization efforts and results, aimed at identification and testing carbon black and surfactant combinations that would produce stable dispersions, with carbon particle sizes below 1 {micro}m, in aqueous HMTA/urea and ADUN solutions. A battery of characterization methods was used to identify the properties affecting the water dispersability of carbon blacks, such as surface area, aggregate morphology, volatile content, and, most importantly, surface chemistry. The report introduces the basic principles for each physical or chemical method of carbon black characterization, lists the results obtained, and underlines cross-correlations between methods. Particular attention is given to a newly developed method for characterization of surface chemical groups on carbons in terms of their acid-base properties (pK{sub a} spectra) based on potentiometric titration. Fourier-transform infrared (FTIR) spectroscopy was used to confirm the identity of surfactants, both ionic and non-ionic. In addition, background information on carbon black properties and the mechanism by which surfactants disperse carbon black in water is also provided. A list of main physical and chemical properties characterized, samples analyzed, and results obtained, as well as information on the desired trend or

  15. Effect of sterilization on mineralization of straw and black carbon

    OpenAIRE

    Bobul'ská, Lenka; Bruun, Sander; Fazekašová, Danica

    2013-01-01

    The study was aimed at investigating the role of microorganisms in the degradation of BC (black carbon). CO evolution was measured under sterilized and non-sterilized soil using BC and straw amendments. Black carbon and straw were produced from homogenously C labelled roots of barley (Hordeum vulgare) with a specific activity 2.9 MBq g C. Production of BC was implemented at 300 °C for 24 h in a muffle oven, incubated in soil and C in the evolved CO was measured after 0.5, 1, 2, 4, 8, 16, 26 a...

  16. Effects of carbon blacks with various structures on vulcanization and reinforcement of filled ethylene-propylene-diene rubber

    Directory of Open Access Journals (Sweden)

    2008-10-01

    Full Text Available The effects of carbon blacks on vulcanization and mechanical properties of filled ethylene-propylene-diene rubber (EPDM are investigated, by comparing with five types of rubber-grade carbon blacks. Curing kinetics is studied by rheometer and the results indicate that the curing characteristics are influenced by combination of surface area of carbon black and sulphur content on the filler surface, because the former one enhances the physical cross-linking and the latter one introduces the additional chemical cross-linking. Both the degree of cross-linking and cure rate increase with increasing surface area and sulphur content, whereas the optimum cure time and scorch time decrease. The reinforcing nature of the carbon black is assessed from mechanical measurements. It is suggested that the surface area of carbon blacks strongly affects the physical properties of EPDM/carbon black composites. Conductive carbon black (N472 can be used as desirable reinforcing filler due to the higher degree of cross-linking of EPDM with N472 than other EPDM/carbon black composites. The morphology and distribution of particles are studied by using scanning electron microscope. The sound reinforcing ability of N472 is also supported by scanning electron microscope due to the notable dispersibility of N472 within EPDM matrix. N472 ensures the EPDM/N472 composite the most conductive sample among the five composites.

  17. Hydrogen and Carbon Black Production from Thermal Decomposition of Sub-Quality Natural Gas

    Directory of Open Access Journals (Sweden)

    M. Javadi

    2010-03-01

    Full Text Available The objective of this paper is computational investigation of the hydrogen and carbon black production through thermal decomposition of waste gases containing CH4 and H2S, without requiring a H2S separation process. The chemical reaction model, which involves solid carbon, sulfur compounds and precursor species for the formation of carbon black, is based on an assumed Probability Density Function (PDF parameterized by the mean and variance of mixture fraction and β-PDF shape. The effects of feedstock mass flow rate and reactor temperature on hydrogen, carbon black, S2, SO2, COS and CS2 formation are investigated. The results show that the major factor influencing CH4 and H2S conversions is reactor temperature. For temperatures higher than 1100° K, the reactor CH4 conversion reaches 100%, whilst H2S conversion increases in temperatures higher than 1300° K. The results reveal that at any temperature, H2S conversion is less than that of CH4. The results also show that in the production of carbon black from sub-quality natural gas, the formation of carbon monoxide, which is occurring in parallel, play a very significant role. For lower values of feedstock flow rate, CH4 mostly burns to CO and consequently, the production of carbon black is low. The results show that the yield of hydrogen increases with increasing feedstock mass flow rate until the yield reaches a maximum value, and then drops with further increase in the feedstock mass flow rate.

  18. Hot electron-induced electrochemiluminescence at polyetherimide-carbon black-based electrodes

    International Nuclear Information System (INIS)

    Salminen, Kalle; Grönroos, Päivi; Johansson, Leena-Sisko; Campbell, Joseph; Kulmala, Sakari

    2017-01-01

    Highlights: • Generation of hydrated electrons at carbon paste electrodes. • Hydrated electrons are able to produce intense chemiluminescence. • Relationship between carbon black content in electrode and HECL studied. • Performance of composite electrodes is similar to aluminum electrodes. • The present electrodes are good alternative for disposable assay cartridges. - Abstract: Various luminophores produce strong electrogenerated chemiluminescence during cathodic pulse polarization of the present insulating film-covered carbon paste electrodes in fully aqueous solutions. First electrodes made of a commercial conductive carbon paste were successfully utilized as working electrodes and their surface was characterized by ESCA. Then custom in-laboratory made improved composite electrodes were manufactured from the same insulating polymer and conducting carbon black particles. The relationship between the amount of carbon present on the composite electrode, in the bulk and on the surface, and the intensity of electrogenerated chemiluminescence was studied further. The overall performance of these composite electrodes makes them viable low-cost replacements for metal/insulator type electrodes such as oxide-coated silicon electrodes.

  19. Dynamac molecular structure of plant biomass-derived black carbon (Biochar)

    Science.gov (United States)

    Char black carbon (BC), the solid residue of incomplete combustion, is continuously being added to soils and sediments due to natural vegetation fires, anthropogenic pollution, and new strategies for carbon sequestration (“biochar”). Here we present a molecular-level assessment o...

  20. Effect of sulfur and Nano- carbon black on the mechanical properties of hard rubber

    Directory of Open Access Journals (Sweden)

    Mohamed Hamza Al-Maamori

    2018-01-01

    Full Text Available To improve the properties of hard rubber(Ebonite from natural rubber, added Nano-Carbon black, where measured the properties of tensile, density, hardness and the properties of the vulcanization of a group of samples with different amount of sulfur from 18-36 pphr and different of carbon black (18-26-30 pphr. The results showed that the best carbon black ratio is 30 pphr, where it gives a balance between tensile properties of hand and toughness and flexibility of on the other hand and reduce brittleness in hard rubber.

  1. Influence of public transport in black carbon

    Science.gov (United States)

    Vasquez, Y.; Oyola, P.; Gramsch, E. V.; Moreno, F.; Rubio, M.

    2013-05-01

    As a consequence of poor air quality in Santiago de Chile, several measures were taken by the local authorities to improve the environmental conditions and protect the public health. In year 2005 the Chilean government implemented a project called "Transantiago" aimed to introduce major modifications in the public transportation system. The primary objectives of this project were to: provide an economically, socially and environmentally sustainable service and improve the quality of service without increasing fares. In this work we evaluate the impact of the Transantiago system on the black carbon pollution along four roads directly affected by the modification to the transport system. The black carbon has been used to evaluate changes in air quality due to changes in traffic. The assessment was done using measurements of black carbon before Transantiago (June-July 2005) and after its implementation (June-July 2007). Four sites were selected to monitor black carbon at street levels, one site (Alameda) that represents trunk-bus streets, i.e., buses crossing the city through main avenues. Buses using these streets had an important technological update with respect to 2005. Two streets (Usach and Departamental) show a mixed condition, i.e., they combine feeder and trunk buses. These streets combine new EURO III buses with old buses with more than 3 years of service. The last street (Eliodoro Yañez) represent private cars road without public transportation and did not experience change. Hence, the results from the years 2005 and 2007 can be directly compared using an appropriate methodology. To ensure that it was not the meteorological conditions that drive the trends, the comparison between year 2005 and 2007 was done using Wilcoxon test and a regression model. A first assessment at the four sites suggested a non decrease in black carbon concentration from 2005 to 2007, except for Alameda. A first statistical approach confirmed small increases in BC in Usach and E

  2. Arctic Black Carbon Loading and Profile Using the Single-Particle Soot Photometer (SP2) Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Sedlacek, Arthur J [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-05-01

    One of the major issues confronting aerosol climate simulations of the Arctic and Antarctic cryospheres is the lack of detailed data on the vertical and spatial distribution of aerosols with which to test these models. This is due, in part, to the inherent difficulty of conducting such measurements in extreme environments. However given the pronounced sensitivity of the polar regions to radiative balance perturbations, it is incumbent upon our community to better understand and quantify these perturbations, and their unique feedbacks, so that robust model predictions of this region can be realized. One class of under-measured radiative forcing agents in the polar region is the absorbing aerosol—black carbon and brown carbon. Black carbon (BC; also referred to as light-absorbing carbon [LAC], refractory black carbon [rBC], and soot) is second only to CO2 as a positive forcing agent. Roughly 60% of BC emissions can be attributed to anthropogenic sources (fossil fuel combustion and open-pit cooking), with the remaining fraction being due to biomass burning. Brown carbon (BrC), a major component of biomass burning, collectively refers to non-BC carbonaceous aerosols that typically possess minimal light absorption at visible wavelengths but exhibit pronounced light absorption in the near-ultraviolet (UV) spectrum. Both species can be sourced locally or be remotely transported to the Arctic region and are expected to perturb the radiative balance. The work conducted in this field campaign addresses one of the more glaring deficiencies currently limiting improved quantification of the impact of BC radiative forcing in the cryosphere: the paucity of data on the vertical and spatial distributions of BC. By expanding the Gulfstream aircraft (G-1) payload for the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility-sponsored ACME-V campaign to include the Single-Particle Soot Photometer (SP2)) and leveraging the ACME-V campaign

  3. Estimation of Black Carbon Emissions from Dry Dipterocarp Forest Fires in Thailand

    Directory of Open Access Journals (Sweden)

    Ubonwan Chaiyo

    2014-12-01

    Full Text Available This study focused on the estimation of black carbon emissions from dry dipterocarp forest fires in Thailand. Field experiments were set up at the natural forest, Mae Nam Phachi wildlife sanctuary, Ratchaburi Province, Thailand. The dead leaves were the main component consumed of the surface biomass with coverage higher than 90% in volume and mass. The dead leaves load was 342 ± 190 g∙m−2 and followed by a little mass load of twig, 100 g∙m−2. The chemical analysis of the dead leaves showed that the carbon content in the experimental biomass fuel was 45.81 ± 0.04%. From the field experiments, it was found that 88.38 ± 2.02% of the carbon input was converted to carbon released to the atmosphere, while less than 10% were left in the form of residues, and returned to soil. The quantity of dead leaves consumed to produce each gram of carbon released was 2.40 ± 0.02 gdry biomass burned. From the study, the emissions factor of carbon dioxide, carbon monoxide, particulate matter (PM2.5 and black carbon amounted 1329, 90, 26.19 and 2.83 g∙kg−1dry biomass burned, respectively. In Thailand, the amount of black carbon emissions from dry dipterocarp forest fires amounted 17.43 tonnes∙y−1.

  4. A black body absorber from vertically aligned single-walled carbon nanotubes

    Science.gov (United States)

    Mizuno, Kohei; Ishii, Juntaro; Kishida, Hideo; Hayamizu, Yuhei; Yasuda, Satoshi; Futaba, Don N.; Yumura, Motoo; Hata, Kenji

    2009-01-01

    Among all known materials, we found that a forest of vertically aligned single-walled carbon nanotubes behaves most similarly to a black body, a theoretical material that absorbs all incident light. A requirement for an object to behave as a black body is to perfectly absorb light of all wavelengths. This important feature has not been observed for real materials because materials intrinsically have specific absorption bands because of their structure and composition. We found a material that can absorb light almost perfectly across a very wide spectral range (0.2–200 μm). We attribute this black body behavior to stem from the sparseness and imperfect alignment of the vertical single-walled carbon nanotubes. PMID:19339498

  5. Study of black carbon levels in city centers and industrial centers in Jordan

    International Nuclear Information System (INIS)

    Hamasha, K.M.; Almomani, M.S.; Abu-Allaban, M.; Arnott, W. P.

    2010-01-01

    Light absorption coefficients of black carbon (B abc ) were measured at serveral urban and industrial locations in Jordan during summer of 2007 and winter of 2008 using the photoacoustic instrument at a wavelength of 870 nm. Black carbon mass concentration (BC) was calculated using B abc .Black carbon levels at urban locations in the summer of 2007 were higher than those obtained at industrial centers.Zarqa had the highest value of BC in summer (29.24μg/m 3 ) and in winter (13.27μg/m 3 ). Ibbeen and Irbid city center had relatively high values of BC in winter: 11.75μg/m 3 and 12.48μg/m 3 , respectively. (authors).

  6. Sonoelectrochemical one-pot synthesis of Pt - Carbon black nanocomposite PEMFC electrocatalyst.

    Science.gov (United States)

    Karousos, Dionysios S; Desdenakis, Kostantinos I; Sakkas, Petros M; Sourkouni, Georgia; Pollet, Bruno G; Argirusis, Christos

    2017-03-01

    Simultaneous electrocatalytic Pt-nanoparticle synthesis and decoration of Vulcan XC-72 carbon black substrate was achieved in a novel one-step-process, combining galvanostatic pulsed electrodeposition and pulsed ultrasonication with high power, low-frequency (20kHz) ultrasound. Aqueous chloroplatinic acid precursor baths, as well as carbon black suspensions in the former, were examined and decoration was proven by a combination of characterization methods, namely: dynamic light scattering, transmission electron microscopy, scanning electron microscopy with EDX-analysis and cyclic voltammetry. In particular, PVP was shown to have a beneficial stabilizing effect against free nanoparticle aggregation, ensuring narrow size distributions of the nanoparticles synthesized, but is also postulated to prevent the establishment of a strong metal-substrate interaction. Current pulse amplitude was identified as the most critical nanoparticle size-determining parameters, while only small size particles, under 10nm, appeared to be attached to carbon black. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Morphology and Optical Properties of Black-Carbon Particles Relevant to Engine Emissions

    Science.gov (United States)

    Michelsen, H. A.; Bambha, R.; Dansson, M. A.; Schrader, P. E.

    2013-12-01

    Black-carbon particles are believed to have a large influence on climate through direct radiative forcing, reduction of surface albedo of snow and ice in the cryosphere, and interaction with clouds. The optical properties and morphology of atmospheric particles containing black carbon are uncertain, and characterization of black carbon resulting from engines emissions is needed. Refractory black-carbon particles found in the atmosphere are often coated with unburned fuel, sulfuric acid, water, ash, and other combustion by-products and atmospheric constituents. Coatings can alter the optical and physical properties of the particles and therefore change their optical properties and cloud interactions. Details of particle morphology and coating state can also have important effects on the interpretation of optical diagnostics. A more complete understanding of how coatings affect extinction, absorption, and incandescence measurements is needed before these techniques can be applied reliably to a wide range of particles. We have investigated the effects of coatings on the optical and physical properties of combustion-generated black-carbon particles using a range of standard particle diagnostics, extinction, and time-resolved laser-induced incandescence (LII) measurements. Particles were generated in a co-flow diffusion flame, extracted, cooled, and coated with oleic acid. The diffusion flame produces highly dendritic soot aggregates with similar properties to those produced in diesel engines, diffusion flames, and most natural combustion processes. A thermodenuder was used to remove the coating. A scanning mobility particle sizer (SMPS) was used to monitor aggregate sizes; a centrifugal particle mass analyzer (CPMA) was used to measure coating mass fractions, and transmission electron microscopy (TEM) was used to characterize particle morphologies. The results demonstrate important differences in optical measurements between coated and uncoated particles.

  8. Characteristics of black carbon in snow from Laohugou No. 12 glacier on the northern Tibetan Plateau.

    Science.gov (United States)

    Zhang, Yulan; Kang, Shichang; Li, Chaoliu; Gao, Tanguang; Cong, Zhiyuan; Sprenger, Michael; Liu, Yajun; Li, Xiaofei; Guo, Junming; Sillanpää, Mika; Wang, Kun; Chen, Jizu; Li, Yang; Sun, Shiwei

    2017-12-31

    Black carbon (BC) emitted from the incomplete combustion of biomass and fossil fuel impacts the climate system, cryospheric change, and human health. This study documents black carbon deposition in snow from a benchmark glacier on the northern Tibetan Plateau. Significant seasonality of BC concentrations indicates different input or post-depositional processes. BC particles deposited in snow had a mass volume median diameter slightly larger than that of black carbon particles typically found in the atmosphere. Also, unlike black carbon particles in the atmosphere, the particles deposited in snow did not exhibit highly fractal morphology by Scanning Transmission Electron Microscope. Footprint analysis indicated BC deposited on the glacier in summer originated mainly from Central Asia; in winter, the depositing air masses generally originated from Central Asia and Pakistan. Anthropogenic emissions play an important role on black carbon deposition in glacial snow, especially in winter. The mass absorption efficiency of BC in snow at 632nm exhibited significantly seasonality, with higher values in summer and lower values in winter. The information on black carbon deposition in glacial snow provided in this study could be used to help mitigate the impacts of BC on glacier melting on the northern Tibetan Plateau. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. The structure of carbon black-elastomer composites by small-angle neutron scattering and the method of contrast variation

    International Nuclear Information System (INIS)

    Hjelm, R.P.; Wampler, W.; Gerspacher, M.

    1996-01-01

    We have been exploring the use of small-angle neutron scattering and the method of contrast variation to give a new look at a very old problem: reinforcement of elastomers by carbon black in durable rubber products. Carbon black has a hierarchy of structures consisting of particles covalently bound into aggregates, which in turn associate by weak interactions into agglomerates. We found that in one carbon black, HSA, the aggregates are rodlike, containing an average of 4-6 particles. The aggregates have an outer graphitic shell and an inner core of lower density carbon. The core is continuous throughout the carbon black aggregate. Contrast variation of swollen HSA-polyisoprene gels shows that the HSA is completely embedded in polyisoprene and that the agglomerates are formed predominantly by end on associations of the rodlike aggregates. The surface structure of the carbon black appears smooth over length scales above about 10 angstrom. Further studies using production carbon blacks suggest that these structural characteristics are generally present in commercial rubber composites

  10. Contribution of Black Carbon Aerosol to Drying of the Mediterranean

    Science.gov (United States)

    Tang, T.; Shindell, D. T.; Samset, B. H.; Boucher, O.; Forster, P.; Hodnebrog, Ø.; Myhre, G.; Sillmann, J.; Voulgarakis, A.; Andrews, T.; Faluvegi, G.; Fläschner, D.; Iverson, T.; Kasoar, M.; Kharin, V. V.; Kirkevag, A.; Lamarque, J. F.; Olivié, D.; Richardson, T.; Stjern, C.; Takemura, T.; Zwiers, F. W.

    2017-12-01

    Atmospheric aerosols affect cloud properties, radiative balance and thus, the hydrological cycle. Many studies have reported that precipitation has decreased in the Mediterranean since the mid-20th century, and investigated possible mechanisms. So far, however, the effects of aerosol forcing on Mediterranean precipitation remain largely unknown. Here we compare observed Mediterranean precipitation trends during 1951-2010 with responses to individual forcing in a set of state-of-the-art global climate models. Our analyses suggest that nearly one-third (30%) of the observed precipitation decrease may be attributable to black carbon forcing. The remainder is most strongly linked to forcing of well-mixed greenhouse gases (WMGHGs), with scattering sulfate aerosols having negligible impacts. Black carbon caused an enhanced positive North Atlantic Oscillation (NAO)/Arctic Oscillation (AO)-like sea level pressure (SLP) pattern, characterized by higher SLP at mid-latitudes and lower SLP at high-latitudes. This SLP change diverted the jet stream and storm tracks further northward, reducing precipitation in the Mediterranean while increasing precipitation in Northern Europe. The results from this study suggest that future black carbon emissions may significantly affect regional water resources, agricultural practices, ecosystems, and economy in the Mediterranean region.

  11. Electric anisotropy in high density polyethylene + carbon black composites induced by mechanical deformation

    Energy Technology Data Exchange (ETDEWEB)

    Vigueras-Santiago, E; Hernandez-Lopez, S; Camacho-Lopez, M A; Lara-Sanjuan, O, E-mail: eviguerass@uaemex.m [Laboratorio de Investigacion y Desarrollo de Materiales Avanzados (LIDMA), Facultad de Quimica, UAEM. Paseo Colon esq. con Paseo Tollocan, s/n. C.P. 50000, Toluca (Mexico)

    2009-05-01

    High density polyethylene + carbon black composites with electrical anisotropy was studied. Electrical anisotropy was induced by uniaxial mechanical deformation and injection moulding. We show that anisotropy depends on the carbon black concentration and percentage deformation. Resistivity had the highest anisotropy resistivity around the percolation threshold. Perpendicular resistivity showed two magnitude orders higher than parallel resistivity for injected samples, whereas resistivity showed an inverse behaviour for 100% tensile samples. Both directions were set respect to the deformation axe. Anisotropy could be explained in terms of the molecular deformation (alignment) of the polymer chains as a response of the deformation process originating a redistribution of the carbon black particles in both directions. Alignment of the polymer chains was evidenced by polarized Raman spectroscopy.

  12. Effect of carbon black on electrical and rheological properties of graphite nanoplatelets/poly(ethylene-butyl acrylate composites

    Directory of Open Access Journals (Sweden)

    H. Oxfall

    2015-01-01

    Full Text Available The effect of adding carbon black on the electrical and rheological properties of graphite nanoplatelets/poly(ethylene-butyl acrylate copolymer composites produced via melt or solution mixing was studied. By adding a small amount of low- or high-structured carbon black to the nanocomposite, the electrical percolation threshold decreased and the final conductivity (at higher filler contents increased. The effect on the percolation threshold was significantly stronger in case of the high-structured carbon black where replacing 10 wt% of the total filler content with carbon black instead of graphite nanoplatelets reduced the electrical percolation threshold from 6.9 to 4.6 vol%. Finally, the solution mixing process was found to be more efficient leading to a lower percolation threshold. For the composites containing high-structured carbon black, graphite nanoplatelets and their hybrids there was a quite reasonable correlation between the electrical and rheological percolation thresholds.

  13. Personal exposure to Black Carbon in transport microenvironments

    Science.gov (United States)

    Dons, Evi; Int Panis, Luc; Van Poppel, Martine; Theunis, Jan; Wets, Geert

    2012-08-01

    We evaluated personal exposure of 62 individuals to the air pollutant Black Carbon, using 13 portable aethalometers while keeping detailed records of their time-activity pattern and whereabouts. Concentrations encountered in transport are studied in depth and related to trip motives. The evaluation comprises more than 1500 trips with different transport modes. Measurements were spread over two seasons. Results show that 6% of the time is spent in transport, but it accounts for 21% of personal exposure to Black Carbon and approximately 30% of inhaled dose. Concentrations in transport were 2-5 times higher compared to concentrations encountered at home. Exposure was highest for car drivers, and car and bus passengers. Concentrations of Black Carbon were only half as much when traveling by bike or on foot; when incorporating breathing rates, dose was found to be twice as high for active modes. Lowest 'in transport' concentrations were measured in trains, but nevertheless these concentrations are double the concentrations measured at home. Two thirds of the trips are car trips, and those trips showed a large spread in concentrations. In-car concentrations are higher during peak hours compared to off-peak, and are elevated on weekdays compared to Saturdays and even more so on Sundays. These findings result in significantly higher exposure during car commute trips (motive 'Work'), and lower concentrations for trips with motive 'Social and leisure'. Because of the many factors influencing exposure in transport, travel time is not a good predictor of integrated personal exposure or inhaled dose.

  14. Temporal variation and source identification of black carbon at Lin'an and Longfengshan regional background stations in China

    Science.gov (United States)

    Cheng, Siyang; Wang, Yaqiang; An, Xingqin

    2017-12-01

    Black carbon (BC) is a component of fine particulate matter (PM2.5), associated with climate, weather, air quality, and people's health. However, studies on temporal variation of atmospheric BC concentration at background stations in China and its source area identification are lacking. In this paper, we use 2-yr BC observations from two background stations, Lin'an (LAN) and Longfengshan (LFS), to perform the investigation. The results show that the mean diurnal variation of BC has two significant peaks at LAN while different characteristics are found in the BC variation at LFS, which are probably caused by the difference in emission source contributions. Seasonal variation of monthly BC shows double peaks at LAN but a single peak at LFS. The annual mean concentrations of BC at LAN and LFS decrease by 1.63 and 0.26 μg m-3 from 2009 to 2010, respectively. The annual background concentration of BC at LAN is twice higher than that at LFS. The major source of the LAN BC is industrial emission while the source of the LFS BC is residential emission. Based on transport climatology on a 7-day timescale, LAN and LFS stations are sensitive to surface emissions respectively in belt or approximately circular area, which are dominated by summer monsoon or colder land air flows in Northwest China. In addition, we statistically analyze the BC source regions by using BC observation and FLEXible PARTicle dispersion model (FLEXPART) simulation. In summer, the source regions of BC are distributed in the northwest and south of LAN and the southwest of LFS. Low BC concentration is closely related to air mass from the sea. In winter, the source regions of BC are concentrated in the west and south of LAN and the northeast of the threshold area of s tot at LFS. The cold air mass in the northwest plays an important role in the purification of atmospheric BC. On a yearly scale, sources of BC are approximately from five provinces in the northwest/southeast of LAN and the west of LFS. These

  15. Thickness effect on electric resistivity on polystyrene and carbon black- based composites

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Lopez, S; Vigueras-Santiago, E [Laboratorio de Investigacion y Desarrollo de Materiales Avanzados (LIDMA) Facultad de Quimica, Paseo Colon Esquina con Paseo Tollocan, s/n, CP 50000, Toluca (Mexico); Mayorga-Rojas, M; Reyes-Contreras, D, E-mail: eviguerass@uaemex.m [Facultad de Ciencias, Universidad Autonoma del Estado de Mexico. Av. Instituto Literario 100 Ote. C. P. 50000, Toluca (Mexico)

    2009-05-01

    Changes on electrical resistivity were experimentally studied for polystyrene and carbon black-based composites respect to the temperature. 22% w/w carbon black composite films at 30{mu}m, 2mm y 1cm thick were submitted to thermal heating-cooling cycles from room temperature to 100 deg. C, slightly up to T{sub g} of the composite. For each cycle changes on electrical resistivity constituent a hysteresis loop that depends on the sample thickness. The changes during the heating stage could be explained as a consequence of the thermal expansion and mobility of the polymer chains at T{sub g}, producing a disconnecting of the electrical contacts among carbon black particles and an important increasing (200%) of the electrical resistivity. For each cycle, the hysteresis loop was observed in thicker samples, whereas for 30 mu m thickness sample the hysteresis loop was lost after four cycles.

  16. Comparing black carbon types in sequestering polybrominated diphenyl ethers (PBDEs) in sediments

    International Nuclear Information System (INIS)

    Jia, Fang; Gan, Jay

    2014-01-01

    Polybrominated diphenyl ethers (PBDEs) are widely found in sediments, especially congeners from the penta-BDE formula. Due to their strong affinity for black carbon (BC), bioavailability of PBDEs may be decreased in BC-amended sediments. In this study, we used a matrix-SPME method to measure the freely dissolved concentration (C free ) of PBDEs as a parameter of their potential bioavailability and evaluated the differences among biochar, charcoal, and activated carbon. Activated carbon displayed a substantially greater sequestration capacity than biochar or charcoal. At 1% amendment rate in sediment with low organic carbon (OC) content (0.12%), C free of six PBDEs was reduced by 47.5–78.0%, 47.3–77.5%, and 94.1–98.3% with biochar, charcoal, and activated carbon, respectively, while the sequestration was more limited in sediment with high OC content (0.87%). Therefore, it is important to consider the type and properties of the BC and the sediment in BC-based remediation or mitigation. -- Highlights: • A matrix-SPME method was developed for measuring C free of PBDEs in sediment porewater. • Different black carbon types differed greatly in their ability to decrease C free of PBDEs in sediments. • Activated carbon was much more efficient in sequestering PBDEs than biochar or charcoal. • The effect of black carbon was more pronounced in sediment with lower indigenous OC content. -- Biochar, charcoal, and activated carbon have been compared for their efficacy in sequestering PBDEs in sediments by using a matrix-SPME method

  17. High resolution of black carbon and organic carbon emissions in the Pearl River Delta region, China.

    Science.gov (United States)

    Zheng, Junyu; He, Min; Shen, Xingling; Yin, Shasha; Yuan, Zibing

    2012-11-01

    A high-resolution regional black carbon (BC) and organic carbon (OC) emission inventory for the year 2009 was developed for the Pearl River Delta (PRD) region, China, based on the collected activity data and the latest emission factors. PM(2.5), BC and OC emissions were estimated to be 303 kt, 39 kt and 31 kt, respectively. Industrial processes were major contributing sources to PM(2.5) emissions. BC emissions were mainly from mobile sources, accounting for 65.0%, while 34.1% of OC emissions were from residential combustion. The primary OC/BC ratios for individual cities in the PRD region were dependent on the levels of economic development due to differences in source characteristics, with high ratios in the less developed cities and low ratios in the central and southern developed areas. The preliminary temporal profiles were established, showing the highest OC emissions in winter and relatively constant BC emissions throughout the year. The emissions were spatially allocated into grid cells with a resolution of 3 km × 3 km. Large amounts of BC emissions were distributed over the central-southern PRD city clusters, while OC emissions exhibited a relatively even spatial distribution due to the significant biomass burning emissions from the outlying area of the PRD region. Uncertainties in carbonaceous aerosol emissions were usually higher than in other primary pollutants like SO(2), NO(x), and PM(10). One of the key uncertainty sources was the emission factor, due to the absence of direct measurements of BC and OC emission rates. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Black Carbon and Sulfate Aerosols in the Arctic: Long-term Trends, Radiative Impacts, and Source Attributions

    Science.gov (United States)

    Wang, H.; Zhang, R.; Yang, Y.; Smith, S.; Rasch, P. J.

    2017-12-01

    The Arctic has warmed dramatically in recent decades. As one of the important short-lived climate forcers, aerosols affect the Arctic radiative budget directly by interfering radiation and indirectly by modifying clouds. Light-absorbing particles (e.g., black carbon) in snow/ice can reduce the surface albedo. The direct radiative impact of aerosols on the Arctic climate can be either warming or cooling, depending on their composition and location, which can further alter the poleward heat transport. Anthropogenic emissions, especially, BC and SO2, have changed drastically in low/mid-latitude source regions in the past few decades. Arctic surface observations at some locations show that BC and sulfate aerosols had a decreasing trend in the recent decades. In order to understand the impact of long-term emission changes on aerosols and their radiative effects, we use the Community Earth System Model (CESM) equipped with an explicit BC and sulfur source-tagging technique to quantify the source-receptor relationships and decadal trends of Arctic sulfate and BC and to identify variations in their atmospheric transport pathways from lower latitudes. The simulation was conducted for 36 years (1979-2014) with prescribed sea surface temperatures and sea ice concentrations. To minimize potential biases in modeled large-scale circulations, wind fields in the simulation are nudged toward an atmospheric reanalysis dataset, while atmospheric constituents including water vapor, clouds, and aerosols are allowed to evolve according to the model physics. Both anthropogenic and open fire emissions came from the newly released CMIP6 datasets, which show strong regional trends in BC and SO2 emissions during the simulation time period. Results show that emissions from East Asia and South Asia together have the largest contributions to Arctic sulfate and BC concentrations in the upper troposphere, which have an increasing trend. The strong decrease in emissions from Europe, Russia and

  19. Black Carbon at the Mt. Bachelor Observatory Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Jaffe, Dan A. [Univ. of Washington, Bothell, WA (United States); Sedlacek, Arthur [Brookhaven National Lab. (BNL), Upton, NY (United States); Laing, James R. [Univ. of Washington, Bothell, WA (United States)

    2017-03-01

    This campaign was initiated to measure refractory black carbon (rBC, as defined in Schwarz et al. (2010)) at the Mt. Bachelor Observatory (MBO) using the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility single-particle soot photometer (SP2; unit 54). MBO is a high-elevation site located on the summit of Mt. Bachelor in central Oregon, USA (43.979°N, 121.687°W, 2,763 meters ASL). This site is operated by Professor Dan Jaffe’s group at the University of Washington Bothell and has been used continuously as an atmospheric observatory for the past 12 years (Jaffe et al., 2005; Gratz et al., 2014). The location of MBO allows frequent sampling of the free troposphere along with a wide array of plumes from regional and distant sources. MBO is currently supported with funding from the National Science Foundation (NSF) to the Principal Investigator (PI; D. Jaffe) via the project “Influence of Free Tropospheric Ozone and PM on Surface Air Quality in the Western U.S.” (#1447832) covering the period 03/15/2015 to 02/28/2018. The SP2 instrument from Droplet Measurement Technologies provides particle-resolved measurements of rBC mass loading, size and mass distributions, and mixing state. The SP2 was installed at MBO on 6/27/2016 and ran through 9/23/2016. Additional measurements at MBO during this campaign included carbon monoxide (CO), fine particulate matter (PM1), aerosol light scattering coefficients (σscat) at three wavelengths using a TSI nephelometer, aerosol absorption coefficients (σabs) with the Brechtel tricolor absorption photometer (TAP), aerosol number size distributions with a scanning mobility particle sizer spectrometer (SMPS), and black carbon (eBC) with an aethalometer. BC data from this campaign have been submitted to the ARM Data Archive. Black carbon (BC) is the predominant light-absorbing aerosol constituent in the atmosphere, and is estimated to exert a positive radiative forcing second only to CO

  20. Low-temperature atmospheric oxidation of mixtures of titanium and carbon black or brown

    International Nuclear Information System (INIS)

    Elizarova, V.A.; Babaitsev, I.V.; Barzykin, V.V.; Gerusova, V.P.; Rozenband, V.I.

    1984-01-01

    This article reports on the thermogravimetric investigation of mixtures of titanium no. 2 and carbon black with various mass carbon contents. Adding carbon black (as opposed to boron) to titanium leads to an increase in the rate of heat release of the oxidation reaction. An attempt is made to clarify the low-temperature oxidation mechanism of titanium mixtures in air. An x-ray phase and chemical (for bound carbon) analysis of specimens of a stoichiometric Ti + C mixture after heating in air to a temperature of 650 0 C at the rate of 10 0 /min was conducted. The results indicate that the oxidation of the titanium-carbon mixture probably proceeds according to a more complex mechanism associated with the transport of the gaseous carbon oxidation products and their participation in the titanium oxidation

  1. Comparison of manufactured and black carbon nanoparticle concentrations in aquatic sediments

    NARCIS (Netherlands)

    Koelmans, A.A.; Nowack, B.; Wiesner, M.

    2009-01-01

    In this paper, we show that concentrations of manufactured carbon-based nanoparticles (MCNPs) in aquatic sediments will be negligible compared to levels of black carbon nanoparticles (BCNPs). This is concluded from model calculations accounting for MCNP sedimentation fluxes, removal rates due to

  2. Ultra-luminous X-ray sources and intermediate-mass black holes

    International Nuclear Information System (INIS)

    Cseh, David

    2012-01-01

    More than ten years ago, the discovery of Ultra-luminous X-ray sources (ULXs) has opened up an entirely new field in astrophysics. Many ideas were developed to explain the nature of these sources, like their emission mechanism, mass, and origin, without any strong conclusions. Their discovery boosted the fields of X-ray binaries, accretion physics, stellar evolution, cosmology, black hole formation and growth, due to the concept of intermediate-mass black holes (IMBHs). Since their discovery is related to the domain of X-ray astrophysics, there have been very few studies made in other wavelengths. This thesis focuses on the multiwavelength nature of Ultra-luminous X-ray sources and intermediate-mass black holes from various aspects, which help to overcome some difficulties we face today. First, I investigated the accretion signatures of a putative intermediate-mass black hole in a particular globular cluster. To this purpose, I characterized the nature of the innermost X-ray sources in the cluster. Then I calculated an upper limit on the mass of the black hole by studying possible accretion efficiencies and rates based on the dedicated X-ray and radio observations. The accreting properties of the source was described with standard spherical accretion and in the context of inefficient accretion. Secondly, I attempted to dynamically measure the mass of the black hole in a particular ULX via optical spectroscopy. I discovered that a certain emission line has a broad component that markedly shifts in wavelength. I investigated the possibility whether this line originates in the accretion disk, and thus might trace the orbital motion of the binary system. I also characterized the parameters of the binary system, such as the mass function, possible orbital separation, the size of the line-emitting region, and an upper limit on the mass of the black hole. Then I studied the environment of a number of ULXs that are associated with large-scale optical and radio nebulae. I

  3. Early growth performances of various seed sources of black (Prunus ...

    African Journals Online (AJOL)

    Early growth performances of various seed sources of black (Prunus serotina Erhr.) and wild cherry ( Prunus avium L.) seedlings on low and high elevation sites in the western Black Sea Region of Turkey.

  4. Stellar-mass black holes and ultraluminous x-ray sources.

    Science.gov (United States)

    Fender, Rob; Belloni, Tomaso

    2012-08-03

    We review the likely population, observational properties, and broad implications of stellar-mass black holes and ultraluminous x-ray sources. We focus on the clear empirical rules connecting accretion and outflow that have been established for stellar-mass black holes in binary systems in the past decade and a half. These patterns of behavior are probably the keys that will allow us to understand black hole feedback on the largest scales over cosmological time scales.

  5. Coatings of black carbon in Tijuana, Mexico, during the CalMex Campaign

    Science.gov (United States)

    Takahama, S.; Russell, L. M.; Duran, R.; Subramanian, R.; Kok, G.

    2010-12-01

    Black carbon number and mass concentrations were measured by a single-particle soot photometer (SP2; by Droplet Measurement Technologies) in Tijuana, Mexico between May 15, 2010, and June 30, 2010, for the CalMex campaign. The measurement site, Parque Morelos, is a recreational area located in the Southeast region of Tijuana. The SP2 was equipped with 8-channels of signal detection that spans a wider range of sensitivity for incandescing and scattering measurements than traditional configurations. The campaign-average number concentration of incandescing particles was 280 #/cc, peaking during traffic activity in the mornings. Incandescing particles made up 50% of all particles (incandescing and purely scattering) detected by the SP2. The mode of the number size distribution estimated for black carbon, according to estimated mass-equivalent diameters, was approximately 100 nm or smaller. Temporal variations in estimated coating thicknesses for these black carbon particles are discussed together with co-located measurements of organic aerosol and inorganic salts.

  6. Black carbon exposure more strongly associated with census tract poverty compared to household income among US black, white, and Latino working class adults in Boston, MA (2003–2010)

    International Nuclear Information System (INIS)

    Krieger, Nancy; Waterman, Pamela D.; Gryparis, Alexandros; Coull, Brent A.

    2014-01-01

    We investigated the association of individual-level ambient exposure to black carbon (spatiotemporal model-based estimate for latitude and longitude of residential address) with individual, household, and census tract socioeconomic measures among a study sample comprised of 1757 US urban working class white, black and Latino adults (age 25–64) recruited for two studies conducted in Boston, MA (2003–2004; 2008–2010). Controlling for age, study, and exam date, the estimated average annual black carbon exposure for the year prior to study enrollment at the participants' residential address was directly associated with census tract poverty (beta = 0.373; 95% confidence interval (CI) 0.322, 0.423) but not with annual household income or education; null associations with race/ethnicity became significant only after controlling for socioeconomic position. - Highlights: • The study included 1757 black, Latino, and white working class adults in Boston, MA. • Census tract poverty was associated with annual average black carbon exposure. • Annual household income was not associated with black carbon exposure. • Individual-level education was not associated with black carbon exposure. • The observed socioeconomic patterns varied by race/ethnicity. - In a US multiethnic urban working adult population, exposure to black carbon was more strongly associated with census tract as compared to household- or individual-level socioeconomic measures

  7. Electrochemical properties of Super P carbon black as an anode active material for lithium-ion batteries

    International Nuclear Information System (INIS)

    Gnanamuthu, RM.; Lee, Chang Woo

    2011-01-01

    Highlights: → A novel attempt of Super P carbon black as an anode active material for lithium-ion batteries. → The first discharge capacity was approximately 1256 mAh g -1 and at the end of 20th cycling the capacity was 610 mAh g -1 at 0.1 C rate. → Coulombic efficiency of Super P carbon black electrode was maintained about 84% at the end of cycling. - Abstract: A new approach to investigate upon the electrochemical properties of Super P carbon black anode material is attempted and compared with conventional mesophase pitch-based carbon fibers (MPCFs) anode material for lithium-ion batteries. The prepared Super P carbon black electrodes are characterized using transmission electron microscope (TEM). The assembled 2032-type coin cells are electrochemically characterized by ac impedance spectroscopic and cyclic voltammetric methods. The electrochemical performance of charge and discharge was analyzed using a battery cycler at 0.1 C rate and cut-off potentials of 1.20 and 0.01 V vs. Li/Li + . The electrochemical test illustrates that the discharge capacity corresponding to Li intercalation into the Super P carbon black electrode is higher and coulombic efficiency is maintained approximately 84% at the end of the 20th cycling at room temperature.

  8. 238U series isotopes and 232Th in carbonates and black shales from the Lesser Himalaya: implications to dissolved uranium abundances in Ganga-Indus source waters

    International Nuclear Information System (INIS)

    Singh, S.K.; Dalai, Tarun K.; Krishnaswami, S.

    2003-01-01

    238 U and 232 Th concentrations and the extent of 238 U- 234 U- 230 Th radioactive equilibrium have been measured in a suite of Precambrian carbonates and black shales from the Lesser Himalaya. These measurements were made to determine their abundances in these deposits, their contributions to dissolved uranium budget of the headwaters of the Ganga and the Indus in the Himalaya and to assess the impact of weathering on 238 U- 234 U- 230 Th radioactive equilibrium in them. 238 U concentrations in Precambrian carbonates range from 0.06 to 2.07 μg g -1 . The 'mean' U/Ca in these carbonates is 2.9 ng U mg -1 Ca. This ratio, coupled with the assumption that all Ca in the Ganga-Indus headwaters is of carbonate origin and that U and Ca behave conservatively in rivers after their release from carbonates, provides an upper limit on the U contribution from these carbonates, to be a few percent of dissolved uranium in rivers. There are, however, a few streams with low uranium concentrations, for which the carbonate contribution could be much higher. These results suggest that Precambrian carbonates make only minor contributions to the uranium budget of the Ganga-Indus headwaters in the Himalaya on a basin wide scale, however, they could be important for particular streams. Similar estimates of silicate contribution to uranium budget of these rivers using U/Na in silicates and Na* (Na corrected for cyclic and halite contributions) in river waters show that silicates can contribute significantly (∼40% on average) to their U balance. If, however, much of the uranium in these silicates is associated with weathering resistant minerals, then the estimated silicate uranium component would be upper limits. Uranium concentration in black shales averages about 37 μg g -1 . Based on this concentration, supply of U from at least ∼50 mg of black shales per liter of river water is needed to balance the average river water U concentration, 1.7 μg L -1 in the Ganga-Indus headwaters

  9. Carbon distribution in char residue from gasification of kraft black liquor

    International Nuclear Information System (INIS)

    Sricharoenchaikul, Viboon; Frederick, W.J.; Agrawal, Pradeep

    2003-01-01

    The char residue yields and the total carbon and carbonate content were measured for dry black liquor solids after pyrolysis or gasification in a laminar entrained-flow reactor. The experimental conditions were 700-1000 deg. C in N 2 ,CO 2 /N 2 or water vapor/N 2 at 1 bar total pressure, for residence times from 0.3 to 1.7 s. Fixed carbon yields, when measured at the same particle residence time, decreased with increasing reactor temperature. CO 2 and water vapor diminished the char carbon significantly at temperatures above 800 deg. C, compared with pyrolysis in N 2 . Water vapor oxidized the char carbon more rapidly than did CO 2 . At 1000 deg. C, the reactions of carbon with sulfate and carbonate became faster, resulting in a smaller difference between carbon conversion rates in the different gas environments. By the end of devolatilization, the amount of carbonate in the char had changed very little at 700-800 deg. C. After devolatilization, carbonate was formed more rapidly at higher temperatures. The presence of CO 2 or water vapor increased the formation of carbonate. In the presence of these gases, more carbonate was measured at all temperatures and residence times. The maximum carbonate measured in the char was 16% of the carbon in the black liquor solids, as compared to 4.4% in the original dry liquor solids. Under most conditions, the carbonate, as a fraction of carbon input, first increased to a constant, temperature-independent value and then decreased

  10. Effect of carbon black on thermal properties of charcoal and salacca leafstalk briquettes

    Science.gov (United States)

    Thassana, Chewa; Nuleg, Witoon

    2017-08-01

    In this work, the effect of a carbon black (CB) on the thermal properties of briquettes produced from the charcoal and the salacca leafstalk with and without CB have been investigated. Four thermal properties of a briquettes compose of the burning time, the calorific value, the percentage moisture (PMC) and an percentage ash content (PAC) were analyzed using standard laboratory methods. Our results were indicated that the sallacca leafstalk mix a carbon black is the long burning times, high heating but a few ash content. Results shown that the burning time and the calorific value of a charcoal, a charcoal with CB, the salacca leafstalk and the salacca leafstalk with carbon black particles is about 58, 63, 76, 81 minutes, and 10.33, 12.96, 13.12, 14.63 MJ/kg, respectively. In addition, the PMC and PAC were in range of 11.6 - 8.14% and 9.33 - 5.42%. So, we can conclude that a cabon black affect on the thermal properties of a briquettes and salacca leaftstalk mixed CB has been most suited for briquetting.

  11. Black carbon emission reduction strategies in healthcare industry for effective global climate change management.

    Science.gov (United States)

    Raila, Emilia Mmbando; Anderson, David O

    2017-04-01

    Climate change remains one of the biggest threats to life on earth to date with black carbon (BC) emissions or smoke being the strongest cause after carbon dioxide (CO 2 ). Surprisingly, scientific evidence about black carbon emissions reduction in healthcare settings is sparse. This paper presents new research findings on the reduction of black carbon emissions from an observational study conducted at the UN Peacekeeping Operations (MINUSTAH) in Haiti in 2014. Researchers observed 20 incineration cycles, 30 minutes for each cycle of plastic and cardboard sharps healthcare waste (HCW) containers ranged from 3 to 14.6 kg. The primary aim was to determine if black carbon emissions from healthcare waste incineration can be lowered by mainstreaming the use of cardboard sharps healthcare waste containers instead of plastic sharps healthcare waste containers. Similarly, the study looks into whether burning temperature was associated with the smoke levels for each case or not. Independent samples t-tests demonstrated significantly lower black carbon emissions during the incineration of cardboard sharps containers (6.81 ± 4.79% smoke) than in plastic containers (17.77 ± 8.38% smoke); a statistically significant increase of 10.96% smoke (95% Confidence Interval ( CI) [4.4 to 17.5% smoke], p = 0.003). Correspondingly, lower bottom burner temperatures occurred during the incineration of cardboard sharps containers than in plastic (95% Cl [16 to 126°C], p = 0.014). Finally, we expect the application of the new quantitative evidence to form the basis for policy formulation, mainstream the use of cardboard sharps containers and opt for non-incineration disposal technologies as urgent steps for going green in healthcare waste management.

  12. An index-based approach to assessing recalcitrance and soil carbon sequestration potential of engineered black carbons (biochars).

    Science.gov (United States)

    Harvey, Omar R; Kuo, Li-Jung; Zimmerman, Andrew R; Louchouarn, Patrick; Amonette, James E; Herbert, Bruce E

    2012-02-07

    The ability of engineered black carbons (or biochars) to resist abiotic and, or biotic degradation (herein referred to as recalcitrance) is crucial to their successful deployment as a soil carbon sequestration strategy. A new recalcitrance index, the R(50), for assessing biochar quality for carbon sequestration is proposed. The R(50) is based on the relative thermal stability of a given biochar to that of graphite and was developed and evaluated with a variety of biochars (n = 59), and soot-like black carbons. Comparison of R(50), with biochar physicochemical properties and biochar-C mineralization revealed the existence of a quantifiable relationship between R(50) and biochar recalcitrance. As presented here, the R(50) is immediately applicable to pre-land application screening of biochars into Class A (R(50) ≥ 0.70), Class B (0.50 ≤ R(50) carbon sequestration classes. Class A and Class C biochars would have carbon sequestration potential comparable to soot/graphite and uncharred plant biomass, respectively, whereas Class B biochars would have intermediate carbon sequestration potential. We believe that the coupling of the R(50), to an index-based degradation, and an economic model could provide a suitable framework in which to comprehensively assess soil carbon sequestration in biochars.

  13. Regional Responses to Black Carbon Aerosols: The Importance of Air-Sea Interaction

    Science.gov (United States)

    Gnanadesikan, A.; Scott, A. A.; Pradal, M.-A.; Seviour, W. J. M.; Waugh, D. W.

    2017-12-01

    The impact of modern black carbon aerosols on climate via their changes in radiative balance is studied using a coupled model where sea surface temperatures (SSTs) are allowed to vary and an atmosphere-only version of the same model where SSTs are held fixed. Allowing the ocean to respond is shown to have a profound impact on the pattern of temperature change. Particularly, large impacts are found in the North Pacific (which cools by up to 1 K in the coupled model) and in north central Asia (which warms in the coupled simulation and cools in the fixed SST simulation). Neither set of experiments shows large changes in surface temperatures in the Southeast Asian region where the atmospheric burden of black carbon is highest. These results are related to the stabilization of the atmosphere and changes in oceanic heat transport. Over the North Pacific, atmospheric stabilization results in an increase in stratiform clouds. The resulting shading reduces evaporation, freshening the surface layer of the ocean and reducing the inflow of warm subtropical waters. Over the land, a delicate balance between greater atmospheric absorption, shading of the surface and changes in latent cooling of the surface helps to determine whether warming or cooling is seen. Our results emphasize the importance of coupling in determining the response of the climate system to black carbon and suggest that black carbon may play an important role in modulating climate change over the North Pacific.

  14. A new mechanism for selective adsorption of rubber on carbon black surface caused by nano-confinement in SBR/NBR solution

    Science.gov (United States)

    Kawazoe, Masayuki

    A novel mechanism of selective adsorption of rubber molecules onto carbon black surface in a binary immiscible rubber blend solution has been proposed in this dissertation. The phenomenon leads to uneven distribution of carbon black to the specific polymer in the blend and the obtained electrically conductive composite showed drastic reduction of percolation threshold concentration (PTC). The mechanism and the feature of conductive network formation have much potential concerning both fundamental understanding and industrial application to improve conductive polymer composites. In chapter I, carbon black filled conductive polymer composites are briefly reviewed. Then, in chapter II, a mechanism of rubber molecular confinement into carbon black aggregate structure is introduced to explain the selective adsorption of a specific rubber onto carbon black surface in an immiscible rubber solution blend (styrene butadiene rubber (SBR) and acrylonitrile butadiene rubber (NBR) with toluene or chloroform). Next, in chapters III and IV, polymers with various radius of gyration (Rg) and carbon blacks with various aggregate structure are examined to verify the selective adsorption mechanism. Finally, in chapter V, the novel mechanism was applied to create unique meso-/micro-unit conductive network in carbon black dispersed SBR/NBR composites.

  15. Accounting for black carbon lowers estimates of blue carbon storage services.

    Science.gov (United States)

    Chew, Swee Theng; Gallagher, John B

    2018-02-07

    The canopies and roots of seagrass, mangrove, and saltmarsh protect a legacy of buried sedimentary organic carbon from resuspension and remineralisation. This legacy's value, in terms of mitigating anthropogenic emissions of CO 2 , is based on total organic carbon (TOC) inventories to a depth likely to be disturbed. However, failure to subtract allochthonous recalcitrant carbon overvalues the storage service. Simply put, burial of oxidation-resistant organics formed outside of the ecosystem provides no additional protection from remineralisation. Here, we assess whether black carbon (BC), an allochthonous and recalcitrant form of organic carbon, is contributing to a significant overestimation of blue carbon stocks. To test this supposition, BC and TOC contents were measured in different types of seagrass and mangrove sediment cores across tropical and temperate regimes, with different histories of air pollution and fire together with a reanalysis of published data from a subtropical system. The results suggest current carbon stock estimates are positively biased, particularly for low-organic-content sandy seagrass environs, by 18 ± 3% (±95% confidence interval) and 43 ± 21% (±95% CI) for the temperate and tropical regions respectively. The higher BC fractions appear to originate from atmospheric deposition and substantially enrich the relatively low TOC fraction within these environs.

  16. Dissolved black carbon in the global cryosphere: Concentrations and chemical signatures

    Science.gov (United States)

    Khan, Alia L.; Wagner, Sasha; Jaffe, Rudolf; Xian, Peng; Williams, Mark; Armstrong, Richard; McKnight, Diane

    2017-06-01

    Black carbon (BC) is derived from the incomplete combustion of biomass and fossil fuels and can enhance glacial recession when deposited on snow and ice surfaces. Here we explore the influence of environmental conditions and the proximity to anthropogenic sources on the concentration and composition of dissolved black carbon (DBC), as measured by benzenepolycaroxylic acid (BPCA) markers, across snow, lakes, and streams from the global cryosphere. Data are presented from Antarctica, the Arctic, and high alpine regions of the Himalayas, Rockies, Andes, and Alps. DBC concentrations spanned from 0.62 μg/L to 170 μg/L. The median and (2.5, 97.5) quantiles in the pristine samples were 1.8 μg/L (0.62, 12), and nonpristine samples were 21 μg/L (1.6, 170). DBC is susceptible to photodegradation when exposed to solar radiation. This process leads to a less condensed BPCA signature. In general, DBC across the data set was composed of less polycondensed DBC. However, DBC from the Greenland Ice Sheet (GRIS) had a highly condensed BPCA molecular signature. This could be due to recent deposition of BC from Canadian wildfires. Variation in DBC appears to be driven by a combination of photochemical processing and the source combustion conditions under which the DBC was formed. Overall, DBC was found to persist across the global cryosphere in both pristine and nonpristine snow and surface waters. The high concentration of DBC measured in supraglacial melt on the GRIS suggests that DBC can be mobilized across ice surfaces. This is significant because these processes may jointly exacerbate surface albedo reduction in the cryosphere.Plain Language SummaryHere we present dissolved black carbon (DBC) results for snow and glacial melt systems in Antarctica, the Arctic, and high alpine regions of the Himalayas, Rockies, Andes, and Alps. Across the global cryosphere, DBC composition appears to be a result of photochemical processes occurring en route in the atmosphere or in situ on the

  17. Quantifying the variability of potential black carbon transport from cropland burning in Russia driven by atmospheric blocking events

    Science.gov (United States)

    Hall, Joanne; Loboda, Tatiana

    2018-05-01

    The deposition of short-lived aerosols and pollutants on snow above the Arctic Circle transported from northern mid-latitudes have amplified the short term warming in the Arctic region. Specifically, black carbon has received a great deal of attention due to its absorptive efficiency and its fairly complex influence on the climate. Cropland burning in Russia is a large contributor to the black carbon emissions deposited directly onto the snow in the Arctic region during the spring when the impact on the snow/ice albedo is at its highest. In this study, our focus is on identifying a possible atmospheric pattern that may enhance the transport of black carbon emissions from cropland burning in Russia to the snow-covered Arctic. Specifically, atmospheric blocking events are large-scale patterns in the atmospheric pressure field that are nearly stationary and act to block migratory cyclones. The persistent low-level wind patterns associated with these mid-latitude weather patterns are likely to accelerate potential transport and increase the success of transport of black carbon emissions to the snow-covered Arctic during the spring. Our results revealed that overall, in March, the transport time of hypothetical black carbon emissions from Russian cropland burning to the Arctic snow is shorter (in some areas over 50 hours less at higher injection heights) and the success rate is also much higher (in some areas up to 100% more successful) during atmospheric blocking conditions as compared to conditions without an atmospheric blocking event. The enhanced transport of black carbon has important implications for the efficacy of deposited black carbon. Therefore, understanding these relationships could lead to possible mitigation strategies for reducing the impact of deposition of black carbon from crop residue burning in the Arctic.

  18. The Properties of SBR/ENR50 Blend Containing Nanoclay/Carbon Black Dual Filler System Cured by Electron Beam

    Directory of Open Access Journals (Sweden)

    Sima Ahmadi-Shooli

    2017-05-01

    Full Text Available Nanocomposites based on an SBR/ENR50 rubber blend with the blend ratio of 50/50 using Cloisite 15A nanoclay (5 and 10 phr and carbon black (20 phr were prepared by melt mixing process. The rubber compounds were crosslinked by electron beam irradiation process at 50 and 100 kGy doses. A reference sample containing carbon black at 35 phr was prepared using a conventional sulphur curing system. The gel content of the samples was specified using gel fraction measurement. The results showed the maximum gel content for the sample having 5 phr nanoclay and 20 phr carbon black. The dynamic mechanical properties, including the storage modulus, loss modulus, and loss factor, of the nanocomposites were evaluated using dynamic mechanical analysis (DMA tests. The results indicated that, in spite of a well dispersed nanoclay in samples containing 10 phr nanoclay and 20 phr carbon black, a minimum loss factor was observed in the sample containing 5 phr nanoclay and 20 phr carbon black at 100 kGy. On the other hand, the storage modulus of the reference sample was found to be higher than that of the sample with 5 phr nanoclay and 20 phr carbon black. The mechanical properties, including the tensile strength, stress at 100%, 200%, and 300% elongation and the percentage of elongation were measured by a tensile machine. The results showed an increase in tensile strength and the stress at different elongations for a sample with 5 phr nanoclay and 20 phr carbon black compared to the reference sample. In the corresponding SEM images of the samples having nanoclay and carbon black irradiated at 100 kGy a significantly higher surface roughness was observed.

  19. Estimates of increased black carbon emissions from electrostatic precipitators during powdered activated carbon injection for mercury emissions control.

    Science.gov (United States)

    Clack, Herek L

    2012-07-03

    The behavior of mercury sorbents within electrostatic precipitators (ESPs) is not well-understood, despite a decade or more of full-scale testing. Recent laboratory results suggest that powdered activated carbon exhibits somewhat different collection behavior than fly ash in an ESP and particulate filters located at the outlet of ESPs have shown evidence of powdered activated carbon penetration during full-scale tests of sorbent injection for mercury emissions control. The present analysis considers a range of assumed differential ESP collection efficiencies for powdered activated carbon as compared to fly ash. Estimated emission rates of submicrometer powdered activated carbon are compared to estimated emission rates of particulate carbon on submicrometer fly ash, each corresponding to its respective collection efficiency. To the extent that any emitted powdered activated carbon exhibits size and optical characteristics similar to black carbon, such emissions could effectively constitute an increase in black carbon emissions from coal-based stationary power generation. The results reveal that even for the low injection rates associated with chemically impregnated carbons, submicrometer particulate carbon emissions can easily double if the submicrometer fraction of the native fly ash has a low carbon content. Increasing sorbent injection rates, larger collection efficiency differentials as compared to fly ash, and decreasing sorbent particle size all lead to increases in the estimated submicrometer particulate carbon emissions.

  20. Effect of carbon black nanoparticles on methane/air explosions: Influence at low initial turbulence

    Science.gov (United States)

    Torrado, David; Glaude, Pierre-Alexandre; Dufaud, Olivier

    2017-06-01

    Nanoparticles are widely used in industrial applications as additives to modify materials properties such as resistance, surface, rheology or UV-radiation. As a consequence, the quantification and characterization of nanoparticles have become almost compulsory, including the understanding of the risks associated to their use. Since a few years ago, several studies of dust explosion properties involving nano-sized powder have been published. During the production and industrial use of nanoparticles, simultaneous presence of gas / vapor / solvents and dispersed nanoparticles mixtures might be obtained, increasing the risk of a hybrid mixture explosion. The aim of this work is to study the severity of the explosion of carbon black nanoparticles/methane mixtures and understand the influence of adding nanopowders on the behavior of the gas explosions. These results are also useful to understand the influence of soot on the efficiency of the gas combustion. Two grades of carbon black nanoparticles (ranging from 20 to 300 nm average diameter) have been mixed with methane. Tests have been performed on these mixtures in a standard 20 L explosion sphere. Regarding the scale precision, the lowest concentration of carbon black nanoparticles was set at 0.5 g.m-3. Tests were also performed at 2.5 g.m-3, which is still far below 60 g.m-3, the minimum explosive concentration of such powders previously determined in our laboratory. The influence of carbon black particles on the severity of the explosions has been compared to that of pure gas. It appears that the use of carbon black nanoparticles increases the explosion overpressure for lean methane mixtures at low initial turbulences by c. 10%. Similar results were obtained for high initial turbulent systems. Therefore, it seems that carbon black nanoparticles have an impact on the severity of the explosion even for quiescent systems, as opposed to systems involving micro-sized powders that require dispersion at high turbulence

  1. The impact of black wattle encroachment of indigenous grasslands on soil carbon, Eastern Cape, South Africa

    DEFF Research Database (Denmark)

    Oelofse, Myles; Birch-Thomsen, Torben; Magid, Jakob

    2016-01-01

    adverse environmental impacts in South Africa. Little is known about the effects of black wattle encroachment on soil carbon, therefore the aim of this study was to investigate the impact of black wattle encroachment of natural grassland on soil carbon stocks and dynamics. Focussing on two sites...... in the Eastern Cape, South Africa, the study analysed carbon stocks in soil and litter on a chronosequence of black wattle stands of varying ages (up to >50 years) and compared these with adjacent native grassland. The study found that woody encroachment of grassland at one site had an insignificant effect...... on soil and litter carbon stocks. The second site showed a clear decline in combined soil and litter carbon stocks following wattle encroachment. The lowest stock was in the oldest wattle stand, meaning that carbon stocks are still declining after 50 years of encroachment. The results from the two sites...

  2. Assessment of the surface chemistry of carbon blacks by TGA-MS, XPS and inverse gas chromatography using statistical chemometric analysis

    International Nuclear Information System (INIS)

    Strzemiecka, Beata; Voelkel, Adam; Donate-Robles, Jessica; Martín-Martínez, José Miguel

    2014-01-01

    Highlights: • Carbon blacks with lower specific surface area had basic character (electron donor) due to C=O and C-O groups. • Carbon blacks with higher specific surface area had acidic character (acceptor electron) due to OH groups. • Total surface energy and its dispersive component of carbon blacks increased by increasing their specific surface area. (table) - Abstract: Four carbon blacks with different specific surface areas and surface chemistries (C32, C71, C159 and C178) were analyzed by transmission electron microscopy (TEM) and nitrogen adsorption isotherms at 77 K. Their surface chemistries were analyzed by X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis coupled with mass spectrometry (TGA-MS) and inverse gas chromatography (IGC). The carbon blacks contained 2.7–5.8 wt% volatiles corresponding to -OH, C-O, C=O and COO groups. The surface chemistry parameters obtained with the different experimental techniques were inter-related by using chemometric statistical analysis tools. The application of this methodology showed that the carbon blacks with lower specific surface area (C32 and C71) had basic character (electron donor) mainly due to C=O and C-O groups, whereas the carbon black with the highest specific surface area (C178) showed acidic character (acceptor electron) due to its high content of OH groups. Moreover, the total surface energy and the dispersive component of the surface energy of the carbon blacks increased with the increase of their specific surface area. In general the specific interactions of the carbon blacks also increased with the increase of their specific surface area although C71 is exceptional due to higher oxygen content corresponding to C-O groups

  3. Use of carbon filaments in place of carbon black as the current collector of a lithium cell with a thionyl chloride bromine chloride catholyte

    Science.gov (United States)

    Frysz, Christine A.; Shui, Xiaoping; Chung, D. D. L.

    Submicron carbon filaments (ADNH, Applied Sciences Inc.) used in place of carbon black as porous reduction electrodes (i.e., current collectors) in plate and jellyroll configurations in carbon limited lithium batteries with the BCX (bromine chloride in thionyl chloride) catholyte gave a specific capacity (at 2 V cut-off) of up to 8700 mAh/g of carbon, compared with a value of up to 2900 mAh/g of carbon for carbon black. The high specific capacity for the filament electrode is partly due to the filaments' processability into sheets as thin as 0.2 mm with good porosity, acceptable mechanical properties and without binder, and partly due to the high catholyte absorptivity and high rate of catholyte absorption of the filament electrode. Use of solvent-cleansed filaments in place of as-received filaments in making electrodes increased the packing density, thus decreasing capacity per g of carbon. The BCX catholyte acted as a cleanser anyway, due to the thionyl chloride in it. The specific capacity per cm 3 of carbon and that per unit density of carbon were also increased by using carbon filaments in place of carbon black, provided that the filament electrode was not pressed after forming by slurry filtration. Though no binder was needed for the filament plate electrode, it was needed for the filament jellyroll electrode. The Teflon™ binder increased the tensile strength and modulus, but decreased the catholyte absorption and rate of absorption. The filament electrode exhibited 405 less volume electrical resistivity than the carbon black electrode, both without a binder.

  4. Use of carbon filaments in place of carbon black as the current collector of a lithium cell with a thionyl chloride bromine chloride catholyte

    Energy Technology Data Exchange (ETDEWEB)

    Frysz, C.A. [Technology Div., Wilson Greatbatch Ltd., Clarence, NY (United States); Shui Xiaoping [Composite Materials Research Lab., State Univ. of New York, Buffalo, NY (United States); Chung, D.D.L. [Composite Materials Research Lab., State Univ. of New York, Buffalo, NY (United States)

    1996-01-01

    Submicron carbon filaments (ADNH, Applied Sciences Inc.) used in place of carbon black as porous reduction electrodes (i.e., current collectors) in plate and jellyroll configurations in carbon limited lithium batteries with the BCX (bromine chloride in thionyl chloride) catholyte gave a specific capacity (at 2 V cut-off) of up to 8700 mAh/g of carbon, compared with a value of up to 2900 mAh/g of carbon for carbon black. The high specific capacity for the filament electrode is partly due to the filaments` processability into sheets as thin as 0.2 mm with good porosity, acceptable mechanical properties and without binder, and partly due to the high catholyte absorptivity and high rate of catholyte absorption of the filament electrode. Use of solvent-cleansed filaments in place of as-received filaments in making electrodes increased the packing density, thus decreasing capacity per g of carbon. The BCX catholyte acted as a cleanser anyway, due to the thionyl chloride in it. The specific capacity per cm{sup 3} of carbon and that per unit density of carbon were also increased by using carbon filaments in place of carbon black, provided that the filament electrode was not pressed after forming by slurry filtration. Though no binder was needed for the filament plate electrode, it was needed for the filament jellyroll electrode. The Teflon{sup TM} binder increased the tensile strength and modulus, but decreased the catholyte absorption and rate of absorption. The filament electrode exhibited 40% less volume electrical resistivity than the carbon black electrode, both without a binder. (orig.)

  5. Source attribution of Arctic black carbon constrained by aircraft and surface measurements

    Directory of Open Access Journals (Sweden)

    J.-W. Xu

    2017-10-01

    Full Text Available Black carbon (BC contributes to Arctic warming, yet sources of Arctic BC and their geographic contributions remain uncertain. We interpret a series of recent airborne (NETCARE 2015; PAMARCMiP 2009 and 2011 campaigns and ground-based measurements (at Alert, Barrow and Ny-Ålesund from multiple methods (thermal, laser incandescence and light absorption with the GEOS-Chem global chemical transport model and its adjoint to attribute the sources of Arctic BC. This is the first comparison with a chemical transport model of refractory BC (rBC measurements at Alert. The springtime airborne measurements performed by the NETCARE campaign in 2015 and the PAMARCMiP campaigns in 2009 and 2011 offer BC vertical profiles extending to above 6 km across the Arctic and include profiles above Arctic ground monitoring stations. Our simulations with the addition of seasonally varying domestic heating and of gas flaring emissions are consistent with ground-based measurements of BC concentrations at Alert and Barrow in winter and spring (rRMSE  < 13 % and with airborne measurements of the BC vertical profile across the Arctic (rRMSE  = 17 % except for an underestimation in the middle troposphere (500–700 hPa.Sensitivity simulations suggest that anthropogenic emissions in eastern and southern Asia have the largest effect on the Arctic BC column burden both in spring (56 % and annually (37 %, with the largest contribution in the middle troposphere (400–700 hPa. Anthropogenic emissions from northern Asia contribute considerable BC (27 % in spring and 43 % annually to the lower troposphere (below 900 hPa. Biomass burning contributes 20 % to the Arctic BC column annually.At the Arctic surface, anthropogenic emissions from northern Asia (40–45 % and eastern and southern Asia (20–40 % are the largest BC contributors in winter and spring, followed by Europe (16–36 %. Biomass burning from North America is the most important

  6. Self-sensing piezoresistive cement composite loaded with carbon black particles

    KAUST Repository

    Monteiro, André O.; Cachim, Paulo B.; Da Costa, Pedro M. F. J.

    2017-01-01

    Strain sensors can be embedded in civil engineering infrastructures to perform real-time service life monitoring. Here, the sensing capability of piezoresistive cement-based composites loaded with carbon black (CB) particles is investigated. Several

  7. (2+1-dimensional regular black holes with nonlinear electrodynamics sources

    Directory of Open Access Journals (Sweden)

    Yun He

    2017-11-01

    Full Text Available On the basis of two requirements: the avoidance of the curvature singularity and the Maxwell theory as the weak field limit of the nonlinear electrodynamics, we find two restricted conditions on the metric function of (2+1-dimensional regular black hole in general relativity coupled with nonlinear electrodynamics sources. By the use of the two conditions, we obtain a general approach to construct (2+1-dimensional regular black holes. In this manner, we construct four (2+1-dimensional regular black holes as examples. We also study the thermodynamic properties of the regular black holes and verify the first law of black hole thermodynamics.

  8. Effect of part replacement of silica sand with carbon black on composite properties

    International Nuclear Information System (INIS)

    Adeosun, B.F.; Olaofe, O.

    2003-01-01

    We have reported the properties of natural rubber filled with locally available materials (Adu et al 2000). The effect of local clay, limestone, silica sand and charcoal on the properties of natural rubber has been examined. Results have shown detrimental effects of silica sand on the properties of natural rubber compound. It has been reported that when silica is used as a part for part replacement of carbon black, the heat build up the composite decreased whilst tear resistance improved. Results revealed that within the filler content range used in the present work, the hardness, modulus, and tensile strength of composites loaded with silica sand/carbon black showed enhanced magnitude over the composite loaded singly with silica sand. These parameters generally increased with increasing carbon black content in the composite. New area of use requiring moderate level of tensile strength, hardness and modulus (as in soles of shoes and engine mounts) is therefore opened up for silica sand.(author)

  9. Comparison of manufactured and black carbon nanoparticle concentrations in aquatic sediments

    International Nuclear Information System (INIS)

    Koelmans, A.A.; Nowack, B.; Wiesner, M.R.

    2009-01-01

    In this paper, we show that concentrations of manufactured carbon-based nanoparticles (MCNPs) in aquatic sediments will be negligible compared to levels of black carbon nanoparticles (BCNPs). This is concluded from model calculations accounting for MCNP sedimentation fluxes, removal rates due to aggregation or degradation, and MCNP burial in deeper sediment layers. The resultant steady state MCNP levels are compared with BCNP levels calculated from soot levels in sediments and weight fractions of nanosized fractions of these soot particles. MCNP/BCNP ratios range from 10 -7 to 10 -4 (w:w). This suggests that the often acclaimed effect of MCNPs on organic pollutant binding and bioavailability will likely be below the level of detection if natural BCNPs are present, even if binding to MCNP is one to two orders of magnitude stronger than to BCNPs. Furthermore, exposure and toxic effects of MCNPs in sediments and soils will be negligible compared to that of BCNPs. - Concentrations of manufactured carbon-based nanoparticles in sediments and soils will be negligible compared to levels of black carbon (soot) nanoparticles

  10. Particulate Matter and Black Carbon Concentration Levels in Ashaiman, a Semi-Urban Area of Ghana, 2008

    OpenAIRE

    Sam-Quarcoo Dotse; Joshua Kwame Asane; F.G. Ofosu

    2012-01-01

    Particulate matter and black carbon concentration levels in Ashaiman, a semi-urban area of Ghana was assessed. Using IVL PM2.5 and PM10 particle samplers, airborne particulate matter was sampled on Teflon filters for a period of three months. In addition to determination of particulate mass in the two fractions by gravimetrical method, aerosol filters were analyzed to determine Black Carbon (BC) concentration levels using the black smoke method. BC fractions in fine and coarse, together with ...

  11. Potential climate impact of black carbon emitted by rockets

    Science.gov (United States)

    Ross, Martin; Mills, Michael; Toohey, Darin

    2010-12-01

    A new type of hydrocarbon rocket engine is expected to power a fleet of suborbital rockets for commercial and scientific purposes in coming decades. A global climate model predicts that emissions from a fleet of 1000 launches per year of suborbital rockets would create a persistent layer of black carbon particles in the northern stratosphere that could cause potentially significant changes in the global atmospheric circulation and distributions of ozone and temperature. Tropical stratospheric ozone abundances are predicted to change as much as 1%, while polar ozone changes by up to 6%. Polar surface temperatures change as much as one degree K regionally with significant impacts on polar sea ice fractions. After one decade of continuous launches, globally averaged radiative forcing from the black carbon would exceed the forcing from the emitted CO2 by a factor of about 105 and would be comparable to the radiative forcing estimated from current subsonic aviation.

  12. Filtration of Oil-furnace Carbon Black Dust Particles from the Tail Gases by Filter Bags With PTFE Membrane

    Directory of Open Access Journals (Sweden)

    Čuzela, D.

    2010-01-01

    Full Text Available During the industrial production of oil furnace carbon black, tail gases containing oil-furnace carbon black dust particles are emitted to the atmosphere. In the carbon black plant, Petrokemija d. d., there are six exhaust stacks for tail gases. Each of them has installed process equipment for cleaning tail gases. Efficiency of cleaning mainly depends on equipment construction and cleaning technology. The vicinity of the town, quality of the air in the region of Kutina, regarding floating particles PM10, and corporate responsibility for further enviromental improvement, imposes development of new methods that will decrease the emmision of oil-furnace carbon black dust particles in the air. Combining centrifugal percipitator and filter, special construction of cyclofilter for filtration of oil-furnace carbon black dust particles from tail gases by using PTFE (polytetrafluoroethylene membrane filter bags, was designed. Developed filtration technique provides η = 99.9 % efficiency of filtration. Construction part of the filter contains the newest generation of PTFE membrane filter bags with the ability of jet pulse cleaning. Using the PTFE membrane filter bags technology, filtration efficiency for oil-furnace carbon black dust particles in tail gases of maximum γ=5mgm-3can be achieved. The filtration efficiency was monitored continuously measuring the concentration of the oil-furnace carbon black dust particles in the tail gases with the help of in situ electronic probe. The accomplished filtration technology is the base for the installation of the PTFE membrane filter bags in the main operation filters which will provide better protection of the air in the town of Kutina against floating particles PM10.

  13. Black Carbon, Aerosol optical depth and Angstrom Exponent in São Paulo, Brazil

    Science.gov (United States)

    Miranda, R. M.; Perez-Martinez, P. J.; Andrade, M. D. F.

    2017-12-01

    Black carbon (BC) is a major absorber of solar radiation, and its impact on the radiative balance is therefore considered important. Fossil fuel combustion processes and biomass burning result in the emission of BC. Black carbon is being monitored since 2014 with a Multi-Angle Absorption Photometer-MAAP (5012; Thermo Scientific) in the East Zone of São Paulo, Brazil. São Paulo Metropolitan Area with more than 19 million inhabitants, 7 million vehicles, has high concentrations of air pollutants, especially in the winter. Vehicles can be considered the principal source of particles emitted to the atmosphere. Concentration of the pollutant had an average of 1.95 ug.m-3 ± 2.06 and a maximum value of 19.93 ug.m-3. These large variations were due to meteorological effects and to the influence of anthropogenic activities, since samples were collected close to important highways. Winds coming from the East part predominate. Higher concentrations were found in the winter months (June, July and August). Optical data from AERONET (Aerosol Optical Depth-AOD 550 nm and Angstrom Exponent 440-675 nm) were related to BC concentrations for the period from August, 2016. Average values of AOD at 500 nm and Angstrom Parameter (440-675nm) were 0.16±0.11 and 1.44±0.23, respectively. Higher BC concentrations were related to lower Angstrom values.

  14. Black carbon aerosol properties measured by a single particle soot photometer in emissions from biomass burning in the laboratory and field

    Science.gov (United States)

    G. R. McMeeking; J. W. Taylor; A. P. Sullivan; M. J. Flynn; S. K. Akagi; C. M. Carrico; J. L. Collett; E. Fortner; T. B. Onasch; S. M. Kreidenweis; R. J. Yokelson; C. Hennigan; A. L. Robinson; H. Coe

    2010-01-01

    We present SP2 observations of BC mass, size distributions and mixing state in emissions from laboratory and field biomass fires in California, USA. Biomass burning is the primary global black carbon (BC) source, but understanding of the amount emitted and its physical properties at and following emission are limited. The single particle soot photometer (SP2) uses a...

  15. Comparison of structural health assessment capabilities in epoxy – carbon black and epoxy – carbon nanotube nanocomposites

    OpenAIRE

    F. Inam; B. R. Bhat; N. Luhyna; T. Vo

    2014-01-01

    A novel method for comparing structural health of different types of brittle epoxy nanocomposites filled with carbon nanostructured fillers is presented. Epoxy – 0.2 vol% carbon black (CB) and epoxy – 0.2 vol% carbon nanotube (CNT) nanocomposite bars were prepared by calendering and thermal curing. Nanocomposite bars were subjected to Vickers diamond indentation to produce sub-surface damage. Electrical conductivities were analysed by 4-point method to estimate the structural damage caused by...

  16. The theory-practice gap of black carbon mitigation technologies in rural China

    Science.gov (United States)

    Zhang, Weishi; Li, Aitong; Xu, Yuan; Liu, Junfeng

    2018-02-01

    Black carbon mitigation has received increasing attention for its potential contribution to both climate change mitigation and air pollution control. Although different bottom-up models concerned with unit mitigation costs of various technologies allow the assessment of alternative policies for optimized cost-effectiveness, the lack of adequate data often forced many reluctant explicit and implicit assumptions that deviate away from actual situations of rural residential energy consumption in developing countries, where most black carbon emissions occur. To gauge the theory-practice gap in black carbon mitigation - the unit cost differences that lie between what is estimated in the theory and what is practically achieved on the ground - this study conducted an extensive field survey and analysis of nine mitigation technologies in rural China, covering both northern and southern regions with different residential energy consumption patterns. With a special focus on two temporal characteristics of those technologies - lifetimes and annual utilization rates, this study quantitatively measured the unit cost gaps and explain the technical as well as sociopolitical mechanisms behind. Structural and behavioral barriers, which have affected the technologies' performance, are discussed together with policy implications to narrow those gaps.

  17. Exploring biomass based carbon black as filler in epoxy composites: Flexural and thermal properties

    International Nuclear Information System (INIS)

    Abdul Khalil, H.P.S.; Firoozian, P.; Bakare, I.O.; Akil, Hazizan Md.; Noor, Ahmad Md.

    2010-01-01

    Carbon blacks (CB), derived from bamboo stem (BS-CB), coconut shells (CNS-CB) and oil palm empty fiber bunch (EFB-CB), were obtained by pyrolysis of fibers at 700 o C, characterized and used as filler in epoxy composites. The results obtained showed that the prepared carbon black possessed well-developed porosities and are predominantly made up of micropores. The BS-CB, CNS-CB and EFB-CB filled composites were prepared and characterized using scanning electron microscope (SEM) and thermogravimetric analyzer (TGA). The SEM showed that the fractured surface of the composite indicates its high resistance to fracture. The CBs-epoxy composites exhibited better flexural properties than the neat epoxy, which was attributed to better adhesion between the CBs and the epoxy resin. TGA showed that there was improvement in thermal stability of the carbon black filled composites compared to the neat epoxy resin.

  18. 20th-century industrial black carbon emissions altered Arctic climate forcing.

    Science.gov (United States)

    McConnell, Joseph R; Edwards, Ross; Kok, Gregory L; Flanner, Mark G; Zender, Charles S; Saltzman, Eric S; Banta, J Ryan; Pasteris, Daniel R; Carter, Megan M; Kahl, Jonathan D W

    2007-09-07

    Black carbon (BC) from biomass and fossil fuel combustion alters chemical and physical properties of the atmosphere and snow albedo, yet little is known about its emission or deposition histories. Measurements of BC, vanillic acid, and non-sea-salt sulfur in ice cores indicate that sources and concentrations of BC in Greenland precipitation varied greatly since 1788 as a result of boreal forest fires and industrial activities. Beginning about 1850, industrial emissions resulted in a sevenfold increase in ice-core BC concentrations, with most change occurring in winter. BC concentrations after about 1951 were lower but increasing. At its maximum from 1906 to 1910, estimated surface climate forcing in early summer from BC in Arctic snow was about 3 watts per square meter, which is eight times the typical preindustrial forcing value.

  19. Molecular simulation of polycyclic aromatic hydrocarbon sorption to black carbon

    NARCIS (Netherlands)

    Haftka, J.J.H.; Parsons, J.R.; Govers, H.A.J.

    2009-01-01

    Strong sorption of hydrophobic organic contaminants to soot or black carbon (BC) is an important environmental process limiting the bioremediation potential of contaminated soils and sediments. Reliable methods to predict BC sorption coefficients for organic contaminants are therefore required. A

  20. Distribution and sources of dissolved black carbon in surface waters of the Chukchi Sea, Bering Sea, and the North Pacific Ocean

    Science.gov (United States)

    Nakane, Motohiro; Ajioka, Taku; Yamashita, Youhei

    2017-05-01

    Pyrogenic carbon, also called black carbon (BC), is an important component in the global carbon cycle. BC produced by biomass burning or fossil fuel combustion is transported to oceans by the atmosphere or rivers. However, environmental dynamics (i.e., major sources and sinks) of BC in marine environments have not been well documented. In this study, dissolved BC (DBC) collected from surface waters of the Chukchi Sea, the Bering Sea, and the subarctic and subtropical North Pacific were analyzed using the benzene polycarboxylic acid (BPCA) method. The DBC concentration and the ratio of B5CA and B6CA to all BPCAs (an index of the DBC condensation degree) ranged from 4.8 to 15.5 µg-C L-1 and from 0.20 to 0.43, respectively, in surface waters of the Chukchi/Bering Seas and the North Pacific Ocean. The concentration and condensation degree of DBC in the Chukchi/Bering Seas were higher and more variable than those in the subarctic and subtropical North Pacific, which implies that the major factors controlling DBC distribution were different in these marine provinces. In the Chukchi/Bering Seas, the DBC concentration was negatively correlated to salinity but positively correlated to chromophoric dissolved organic matter (CDOM) quantity and total dissolved lignin phenol concentration estimated by CDOM parameters. These correlations indicated that the possible major source of DBC in the Chukchi/Bering Seas was Arctic rivers. However, in the North Pacific, where riverine inputs are negligible for most sampling sites, DBC was possibly derived from the atmosphere. Although spectral slopes of CDOM at 275-295 nm (an index of the photodegradation degree of CDOM) differed widely between the subarctic and subtropical North Pacific, the concentration and condensation degrees of DBC were similar between the subarctic and subtropical North Pacific, which suggests that photodegradation was not the only major factor controlling DBC distribution. Therefore, DBC distributions of the

  1. PTCR effect in carbon black/copolymer composites

    International Nuclear Information System (INIS)

    Costa, L.C.; Chakki, A.; Achour, M.E.; Graca, M.P.F.

    2011-01-01

    Some materials show an abrupt increase in resistivity when the temperature changes only over a few degrees. This phenomenon, known as PTCR effect (positive temperature coefficient of resistivity), has been largely studied in the last few years, due to its potential applications in industry. Particularly, it can be used in auto controlled heaters, temperature sensors, protection circuits and in security systems for power electronic circuits. In this work we present the study of the electrical properties of the percolating system carbon black particles filled with ethylene butylacrylate copolymer composite (EBA), in the temperature range from -100 to 100 o C and in frequencies between 10 Hz and 100 kHz. The PTCR effect was observed at temperatures slightly above the room temperature, for concentrations higher than that of the percolation critical concentration. The mechanism responsible for the change in resistivity, at this stage, is predominantly tunnelling, wherein the conductive filler particles are not in physical contact, and the electrons tunnel through the insulating gap between them. At low temperatures, such as below and close to the glass transition temperature, the DC conductivity obeys the Arrhenius law. The calculated activation energy values are independent of carbon black contents inside the copolymer matrix, suggesting that these particles do not interact significantly with the chain segments of the macromolecules in the EBA copolymer.

  2. PTCR effect in carbon black/copolymer composites

    Energy Technology Data Exchange (ETDEWEB)

    Costa, L.C., E-mail: kady@fis.ua.p [I3N and Physics Department, University of Aveiro, 3810-193 Aveiro (Portugal); Chakki, A.; Achour, M.E. [LASTID, Physics Department, Faculty of Sciences, Ibn Tofail University, BP 133, 14000 Kenitra (Morocco); Graca, M.P.F. [I3N and Physics Department, University of Aveiro, 3810-193 Aveiro (Portugal)

    2011-01-15

    Some materials show an abrupt increase in resistivity when the temperature changes only over a few degrees. This phenomenon, known as PTCR effect (positive temperature coefficient of resistivity), has been largely studied in the last few years, due to its potential applications in industry. Particularly, it can be used in auto controlled heaters, temperature sensors, protection circuits and in security systems for power electronic circuits. In this work we present the study of the electrical properties of the percolating system carbon black particles filled with ethylene butylacrylate copolymer composite (EBA), in the temperature range from -100 to 100 {sup o}C and in frequencies between 10 Hz and 100 kHz. The PTCR effect was observed at temperatures slightly above the room temperature, for concentrations higher than that of the percolation critical concentration. The mechanism responsible for the change in resistivity, at this stage, is predominantly tunnelling, wherein the conductive filler particles are not in physical contact, and the electrons tunnel through the insulating gap between them. At low temperatures, such as below and close to the glass transition temperature, the DC conductivity obeys the Arrhenius law. The calculated activation energy values are independent of carbon black contents inside the copolymer matrix, suggesting that these particles do not interact significantly with the chain segments of the macromolecules in the EBA copolymer.

  3. GHG and black carbon emission inventories from Mezquital Valley: The main energy provider for Mexico Megacity.

    Science.gov (United States)

    Montelongo-Reyes, M M; Otazo-Sánchez, E M; Romo-Gómez, C; Gordillo-Martínez, A J; Galindo-Castillo, E

    2015-09-15

    The greenhouse gases and black carbon emission inventory from IPCC key category Energy was accomplished for the Mezquital Valley, one of the most polluted regions in Mexico, as the Mexico City wastewater have been continuously used in agricultural irrigation for more than a hundred years. In addition, thermoelectric, refinery, cement and chemistry industries are concentrated in the southern part of the valley, near Mexico City. Several studies have reported air, soil, and water pollution data and its main sources for the region. Paradoxically, these sources contaminate the valley, but boosted its economic development. Nevertheless, no research has been done concerning GHG emissions, or climate change assessment. This paper reports inventories performed by the 1996 IPCC methodology for the baseline year 2005. Fuel consumption data were derived from priority sectors such as electricity generation, refineries, manufacturing & cement industries, transportation, and residential use. The total CO2 emission result was 13,894.9 Gg, which constituted three-quarters of Hidalgo statewide energy category. The principal CO2 sources were energy transformation (69%) and manufacturing (19%). Total black carbon emissions were estimated by a bottom-up method at 0.66 Gg. The principal contributor was on-road transportation (37%), followed by firewood residential consumption (26%) and cocked brick manufactures (22%). Non-CO2 gas emissions were also significant, particularly SO2 (255.9 Gg), which accounts for 80% of the whole Hidalgo State emissions. Results demonstrated the negative environmental impact on Mezquital Valley, caused by its role as a Megacity secondary fuel and electricity provider, as well as by the presence of several cement industries. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Hydrogen and Carbon Black Production from the Degradation of Methane by Thermal Plasma

    Directory of Open Access Journals (Sweden)

    Leila Cottet

    2014-05-01

    Full Text Available Methane gas (CH4 is the main inducer of the so called greenhouse gases effect. Recent scientific research aims to minimize the accumulation of this gas in the atmosphere and to develop processes capable of producing stable materials with added value. Thermal plasma technology is a promising alternative to these applications, since it allows obtaining H2 and solid carbon from CH4, without the parallel formation of byproducts such as CO2 and NOx. In this work, CH4 was degraded by thermal plasma in order to produce hydrogen (H2 and carbon black. The degradation efficiency of CH4, selectivity for H2 production as well as the characterization of carbon black were studied. The best results were obtained in the CH4 flow rate of 5 L min-1 the degradation percentage and the selectivity for H2 production reached 98.8 % and 48.4 %, respectively. At flow rates of less than 5 L min-1 the selectivity for H2 production increases and reaches 91.9 %. The carbon black has obtained amorphous with hydrophobic characteristics and can be marketed to be used in composite material, and can also be activated chemically and/or physically and used as adsorbent material.

  5. Strong lensing of a regular black hole with an electrodynamics source

    Science.gov (United States)

    Manna, Tuhina; Rahaman, Farook; Molla, Sabiruddin; Bhadra, Jhumpa; Shah, Hasrat Hussain

    2018-05-01

    In this paper we have investigated the gravitational lensing phenomenon in the strong field regime for a regular, charged, static black holes with non-linear electrodynamics source. We have obtained the angle of deflection and compared it to a Schwarzschild black hole and Reissner Nordström black hole with similar properties. We have also done a graphical study of the relativistic image positions and magnifications. We hope that this method may be useful in the detection of non-luminous bodies like this current black hole.

  6. Carbon Black-Modified Electrodes Screen-Printed onto Paper Towel, Waxed Paper and Parafilm M®.

    Science.gov (United States)

    Cinti, Stefano; Mazzaracchio, Vincenzo; Cacciotti, Ilaria; Moscone, Danila; Arduini, Fabiana

    2017-10-03

    Herein, we evaluated the use of paper towel, waxed paper, and Parafilm M ® (Heathrow Scientific, Vernon Hills, IL, USA) as alternative substrates for screen-printed sensor manufacturing. Morphological study was performed to evaluate the adhesion of the ink on these uncommon substrates, as well as the morphology of the working electrode. The electrochemical characterization was carried out using ferricyanide/ferrocyanide as redox couple. To enhance the electrochemical properties of the developed sensors, the nanomaterial carbon black was used as nanomodifier. The modification by drop casting of the working electrode surface, using a stable dispersion of carbon black, allows to obtain a sensor with improved electrochemical behavior in terms of peak-to-peak separation, current intensity, and the resistance of charge transfer. The results achieved confirm the possibility of printing the electrode on several cost-effective paper-based materials and the improvement of the electrochemical behavior by using carbon black as sustainable nanomaterial.

  7. Carbon Black-Modified Electrodes Screen-Printed onto Paper Towel, Waxed Paper and Parafilm M®

    Directory of Open Access Journals (Sweden)

    Stefano Cinti

    2017-10-01

    Full Text Available Herein, we evaluated the use of paper towel, waxed paper, and Parafilm M® (Heathrow Scientific, Vernon Hills, IL, USA as alternative substrates for screen-printed sensor manufacturing. Morphological study was performed to evaluate the adhesion of the ink on these uncommon substrates, as well as the morphology of the working electrode. The electrochemical characterization was carried out using ferricyanide/ferrocyanide as redox couple. To enhance the electrochemical properties of the developed sensors, the nanomaterial carbon black was used as nanomodifier. The modification by drop casting of the working electrode surface, using a stable dispersion of carbon black, allows to obtain a sensor with improved electrochemical behavior in terms of peak-to-peak separation, current intensity, and the resistance of charge transfer. The results achieved confirm the possibility of printing the electrode on several cost-effective paper-based materials and the improvement of the electrochemical behavior by using carbon black as sustainable nanomaterial.

  8. Lung clearance of inhaled particles after exposure to carbon black generated from a resuspension system

    International Nuclear Information System (INIS)

    Lee, P.S.; Gorski, R.A.; Hering, W.E.; Chan, T.L.

    1987-01-01

    A system to resuspend carbon black particles for providing submicron aerosols for inhalation exposure studies has been developed. The effect of continuous exposure to carbonaceous material (as a surrogate for the carbonaceous particles in diesel exhaust) on the pulmonary clearance of inhaled diesel tracer particles was studied in male Fischer 344 rats. Submicron carbon black particles with a mass median aerodynamic diameter (MMAD) of 0.22 micron and a size distribution similar to that of exhaust particles from a GM 5.7-liter diesel engine were successfully generated and administered to test animals at a nominal concentration of 6 mg/m3 for 20 hr/day, 7 days/week, for periods lasting 1 to 11 weeks. Immediately after the carbon black exposure, test animals were administered 14 C-tagged diesel particles for 45 min in a nose-only chamber. The pulmonary retention of inhaled radioactive tracer particles was determined at preselected time intervals. Based upon the data collected up to 1 year postexposure, prolonged exposure to carbon black particles exhibits a similar inhibitory effect on pulmonary clearance as does prolonged exposure to diesel exhaust with a comparable particulate dose. This observation indicates that the excessive accumulation of carbonaceous material may be the predominant factor affecting lung clearance

  9. Central Asian supra-glacier snow melt enhanced by anthropogenic black carbon

    Science.gov (United States)

    Schmale, Julia; Flanner, Mark; Kang, Shichang; Sprenger, Michael; Farinotti, Daniel; Zhang, Qianggong; Guo, Junming; Li, Yang; Lawrence, Mark; Schwikowski, Margit

    2016-04-01

    In Central Asia, more than 60 % of the population depends on water stored in glaciers and mountain snow. Densely populated areas near lower-lying mountain ranges are particularly vulnerable and a recent study showed that the region might lose 50 % of its glacier mass by 2050. While temperature, precipitation and dynamic processes are key drivers of glacial change, deposition of light absorbing impurities such as mineral dust and black carbon can lead to accelerated melting through surface albedo reduction. Here, we discuss the origin of deposited mineral dust and black carbon and their impacts on albedo change and snow melt. 218 snow samples were taken on 4 glaciers, Abramov (Pamir), Suek, Glacier No. 354 and Golubin (Tien Shan), representing deposition between summer 2012 and 2014. They were analyzed for elemental carbon, mineral dust and iron among other parameters. We find the elemental carbon concentration to be at the higher end of the range reported for neighboring mountain ranges between 70 and 502 ng g-1 (interquartile range). To investigate the origin of the snow impurities, we used a Lagrangian particle dispersion model, LAGRANTO. Back trajectory ensembles of 40 members with varied starting points to capture the meteorological spread were released every 6 hours for the covered period at all sites. "Footprints" were calculated and combined with emission inventories to estimate the relative contribution of anthropogenic and natural BC to deposited aerosol on the glaciers. We find that more than 94 % of BC is of anthropogenic origin and the major source region is Central Asia followed by the Middle East. Further exploring the implications of mineral dust and BC deposition, we calculate the snow albedo reduction with the Snow-Ice-Aerosol-Radiative model (SNICAR). Even though mineral dust concentrations were up to a factor of 50 higher than BC concentrations, BC dominates the albedo reduction. Using these results we calculate the snow melt induced by

  10. Relative importance of black carbon, brown carbon, and absorption enhancement from clear coatings in biomass burning emissions

    Science.gov (United States)

    Pokhrel, Rudra P.; Beamesderfer, Eric R.; Wagner, Nick L.; Langridge, Justin M.; Lack, Daniel A.; Jayarathne, Thilina; Stone, Elizabeth A.; Stockwell, Chelsea E.; Yokelson, Robert J.; Murphy, Shane M.

    2017-04-01

    A wide range of globally significant biomass fuels were burned during the fourth Fire Lab at Missoula Experiment (FLAME-4). A multi-channel photoacoustic absorption spectrometer (PAS) measured dry absorption at 405, 532, and 660 nm and thermally denuded (250 °C) absorption at 405 and 660 nm. Absorption coefficients were broken into contributions from black carbon (BC), brown carbon (BrC), and lensing following three different methodologies, with one extreme being a method that assumes the thermal denuder effectively removes organics and the other extreme being a method based on the assumption that black carbon (BC) has an Ångström exponent of unity. The methodologies employed provide ranges of potential importance of BrC to absorption but, on average, there was a difference of a factor of 2 in the ratio of the fraction of absorption attributable to BrC estimated by the two methods. BrC absorption at shorter visible wavelengths is of equal or greater importance to that of BC, with maximum contributions of up to 92 % of total aerosol absorption at 405 nm and up to 58 % of total absorption at 532 nm. Lensing is estimated to contribute a maximum of 30 % of total absorption, but typically contributes much less than this. Absorption enhancements and the estimated fraction of absorption from BrC show good correlation with the elemental-carbon-to-organic-carbon ratio (EC / OC) of emitted aerosols and weaker correlation with the modified combustion efficiency (MCE). Previous studies have shown that BrC grows darker (larger imaginary refractive index) as the ratio of black to organic aerosol (OA) mass increases. This study is consistent with those findings but also demonstrates that the fraction of total absorption attributable to BrC shows the opposite trend: increasing as the organic fraction of aerosol emissions increases and the EC / OC ratio decreases.

  11. End of the Little Ice Age in the Alps forced by industrial black carbon

    OpenAIRE

    Painter, Thomas H.; Flanner, Mark G.; Kaser, Georg; Marzeion, Ben; VanCuren, Richard A.; Abdalati, Waleed

    2013-01-01

    The end of the Little Ice Age in the European Alps has long been a paradox to glaciology and climatology. Glaciers in the Alps began to retreat abruptly in the mid-19th century, but reconstructions of temperature and precipitation indicate that glaciers should have instead advanced into the 20th century. We observe that industrial black carbon in snow began to increase markedly in the mid-19th century and show with simulations that the associated increases in absorbed sunlight by black carbon...

  12. Potential impacts of black carbon on the marine microbial community

    NARCIS (Netherlands)

    Malits, A.; Cattaneo, R.; Sintes, E.; Gasol, J.M.; Herndl, G.J.; Weinbauer, M.G.

    2015-01-01

    Black carbon (BC) is the carbonaceous residue of the incomplete combustion of fossil fuels and biomass and encompasses a range of chemically heterogeneous substances from partly charred plant material to highly condensed soot aerosols. We addressed the potential role of BC aerosol deposition on

  13. Associations between Prenatal Exposure to Black Carbon and Memory Domains in Urban Children: Modification by Sex and Prenatal Stress.

    Science.gov (United States)

    Cowell, Whitney J; Bellinger, David C; Coull, Brent A; Gennings, Chris; Wright, Robert O; Wright, Rosalind J

    2015-01-01

    Whether fetal neurodevelopment is disrupted by traffic-related air pollution is uncertain. Animal studies suggest that chemical and non-chemical stressors interact to impact neurodevelopment, and that this association is further modified by sex. To examine associations between prenatal traffic-related black carbon exposure, prenatal stress, and sex with children's memory and learning. Analyses included N = 258 mother-child dyads enrolled in a Boston, Massachusetts pregnancy cohort. Black carbon exposure was estimated using a validated spatiotemporal land-use regression model. Prenatal stress was measured using the Crisis in Family Systems-Revised survey of negative life events. The Wide Range Assessment of Memory and Learning (WRAML2) was administered at age 6 years; outcomes included the General Memory Index and its component indices [Verbal, Visual, and Attention Concentration]. Relationships between black carbon and WRAML2 index scores were examined using multivariable-adjusted linear regression including effect modification by stress and sex. Mothers were primarily minorities (60% Hispanic, 26% Black); 67% had ≤12 years of education. The main effect for black carbon was not significant for any WRAML2 index; however, in stratified analyses, among boys with high exposure to prenatal stress, Attention Concentration Index scores were on average 9.5 points lower for those with high compared to low prenatal black carbon exposure (P3-way interaction = 0.04). The associations between prenatal exposure to black carbon and stress with children's memory scores were stronger in boys than in girls. Studies assessing complex interactions may more fully characterize health risks and, in particular, identify vulnerable subgroups.

  14. Quantity and quality of black carbon molecular markers as obtained by two chromatographic methods (GC-FID and HPLC-DAD) - How do results compare?

    Science.gov (United States)

    Schneider, M. P. W.; Smittenberg, R. H.; Dittmar, T.; Schmidt, M. W. I.

    2009-04-01

    Chars produced by wildfires are an important source of black carbon (BC) in the environment. After their deposition on the soil surface they can be distributed into rivers, marine waters and sediments. The analysis of benzenepolycarboxylic acids (BPCAs) as a quantitative measure for black carbon (BC) in soil and sediment samples is a well-established method (Glaser et al., 1998; Brodowski et al., 2005). Briefly, the nitric acid oxidation of fused aromatic ring systems in BC forms eight molecular markers (BPCAs), which can be assigned to BC, and which subsequently can be quantified by GC-FID (gas chromatography with flame ionization detector). Recently, this method was modified for the quantification of BC in seawater samples using HPLC-DAD (High performance liquid chromatography with diode array detector) for the determination of individual BPCAs (Dittmar, 2008). A direct comparison of both analytical techniques is lacking but would be important for future data comparison aimed at the calculation of global BC budgets. Here we present a systematic comparison of the two BPCA quantification methods. We prepared chars under well-defined laboratory conditions. In order to cover a broad spectrum of char properties we used two sources of biomass and a wide range of pyrolysis temperatures. Chestnut hardwood chips (Castanea sativa) and rice straw (Oryza sativa) were pyrolysed at temperatures between 200 and 1000°C under a constant N2 stream. The maximum temperatures were held constant for 5 hours (Hammes et al., 2006). The BC contents of the chars have been analysed using the BPCA extraction method followed by either GC-FID or HPLC-DAD quantification. Preliminary results suggest that both methods yield similar total quantities of BPCA, and also the proportions of the individual markers are similar. Ongoing experiments will allow for a more detailed comparison of the two methods. The BPCA composition of chars formed at different temperatures and from different precursor

  15. Quantifying black carbon light absorption enhancement with a novel statistical approach

    Science.gov (United States)

    Wu, Cheng; Wu, Dui; Zhen Yu, Jian

    2018-01-01

    Black carbon (BC) particles in the atmosphere can absorb more light when coated by non-absorbing or weakly absorbing materials during atmospheric aging, due to the lensing effect. In this study, the light absorption enhancement factor, Eabs, was quantified using a 1-year measurement of mass absorption efficiency (MAE) in the Pearl River Delta region (PRD). A new approach for calculating primary MAE (MAEp), the key for Eabs estimation, is demonstrated using the minimum R squared (MRS) method, exploring the inherent source independency between BC and its coating materials. A unique feature of Eabs estimation with the MRS approach is its insensitivity to systematic biases in elemental carbon (EC) and σabs measurements. The annual average Eabs550 is found to be 1.50 ± 0.48 (±1 SD) in the PRD region, exhibiting a clear seasonal pattern with higher values in summer and lower in winter. Elevated Eabs in the summertime is likely associated with aged air masses, predominantly of marine origin, along with long-range transport of biomass-burning-influenced air masses from Southeast Asia. Core-shell Mie simulations along with measured Eabs and absorption Ångström exponent (AAE) constraints suggest that in the PRD, the coating materials are unlikely to be dominated by brown carbon and the coating thickness is higher in the rainy season than in the dry season.

  16. The effects of additional black carbon on the albedo of Arctic sea ice: variation with sea ice type and snow cover

    Directory of Open Access Journals (Sweden)

    A. A. Marks

    2013-07-01

    Full Text Available The response of the albedo of bare sea ice and snow-covered sea ice to the addition of black carbon is calculated. Visible light absorption and light-scattering cross-sections are derived for a typical first-year and multi-year sea ice with both "dry" and "wet" snow types. The cross-sections are derived using data from a 1970s field study that recorded both reflectivity and light penetration in Arctic sea ice and snow overlying sea ice. The variation of absorption cross-section over the visible wavelengths suggests black carbon is the dominating light-absorbing impurity. The response of first-year and multi-year sea ice albedo to increasing black carbon, from 1 to 1024 ng g−1, in a top 5 cm layer of a 155 cm-thick sea ice was calculated using a radiative-transfer model. The albedo of the first-year sea ice is more sensitive to additional loadings of black carbon than the multi-year sea ice. An addition of 8 ng g−1 of black carbon causes a decrease to 98.7% of the original albedo for first-year sea ice compared to a decrease to 99.7% for the albedo of multi-year sea ice, at a wavelength of 500 nm. The albedo of sea ice is surprisingly unresponsive to additional black carbon up to 100 ng g−1 . Snow layers on sea ice may mitigate the effects of black carbon in sea ice. Wet and dry snow layers of 0.5, 1, 2, 5 and 10 cm depth were added onto the sea ice surface. The albedo of the snow surface was calculated whilst the black carbon in the underlying sea ice was increased. A layer of snow 0.5 cm thick greatly diminishes the effect of black carbon in sea ice on the surface albedo. The albedo of a 2–5 cm snow layer (less than the e-folding depth of snow is still influenced by the underlying sea ice, but the effect of additional black carbon in the sea ice is masked.

  17. Black holes as possible sources of closed and semiclosed worlds

    International Nuclear Information System (INIS)

    Frolov, V.P.; Markov, M.A.; Mukhanov, V.F.

    1988-05-01

    The internal structure of spacetime inside a black hole is investigated on the assumption that some limiting curvature exists. It is shown that the Schwarzschild metric inside a black hole can be attached to the de Sitter one at some spacelike junction hypersurface which represents a short transition layer. After passing the deflation stage the de Sitter space inside the black hole begins to inflate and may become a source of a new macroscopic Universe. The corresponding conformal Penrose diagrams are given. The described model may be considered as an example of ''a creation of a closed or semiclosed world in laboratory''. The fate of an evaporating black hole is also briefly discussed. (author). 21 refs, 12 figs

  18. Multi-wavelength Characterization of Brown and Black Carbon from Filter Samples

    Science.gov (United States)

    Johnson, M. M.; Yatavelli, R. L. N.; Chen, L. W. A. A.; Gyawali, M. S.; Arnott, W. P.; Wang, X.; Chakrabarty, R. K.; Moosmüller, H.; Watson, J. G.; Chow, J. C.

    2014-12-01

    Particulate matter (PM) scatters and absorbs solar radiation and thereby affects visibility, the Earth's radiation balance, and properties and lifetimes of clouds. Understanding the radiative forcing (RF) of PM is essential to reducing the uncertainty in total anthropogenic and natural RF. Many instruments that measure light absorption coefficients (βabs [λ], Mm-1) of PM have used light at near-infrared (NIR; e.g., 880 nm) or red (e.g., 633 nm) wavelengths. Measuring βabs over a wider wavelength range, especially including the ultraviolet (UV) and visible, allows for contributions from black carbon (BC), brown carbon (BrC), and mineral dust (MD) to be differentiated. This will help to determine PM RF and its emission sources. In this study, source and ambient samples collected on Teflon-membrane and quartz-fiber filters are used to characterize and develop a multi-wavelength (250 - 1000 nm) filter-based measurement method of PM light absorption. A commercially available UV-visible spectrometer coupled with an integrating sphere is used for quantifying diffuse reflectance and transmittance of filter samples, from which βabs and absorption Ǻngström exponents (AAE) of the PM deposits are determined. The filter-based light absorption measurements of laboratory generated soot and biomass burning aerosol are compared to 3-wavelength photoacoustic absorption measurements to evaluate filter media and loading effects. Calibration factors are developed to account for differences between filter types (Teflon-membrane vs. quartz-fiber), and between filters and in situ photoacoustic absorption values. Application of multi-spectral absorption measurements to existing archived filters, including specific source samples (e.g. diesel and gasoline engines, biomass burning, dust), will also be discussed.

  19. Arctic Aerosols and Sources

    DEFF Research Database (Denmark)

    Nielsen, Ingeborg Elbæk

    2017-01-01

    Since the Industrial Revolution, the anthropogenic emission of greenhouse gases has been increasing, leading to a rise in the global temperature. Particularly in the Arctic, climate change is having serious impact where the average temperature has increased almost twice as much as the global during......, ammonium, black carbon, and trace metals. This PhD dissertation studies Arctic aerosols and their sources, with special focus on black carbon, attempting to increase the knowledge about aerosols’ effect on the climate in an Arctic content. The first part of the dissertation examines the diversity...... of aerosol emissions from an important anthropogenic aerosol source: residential wood combustion. The second part, characterizes the chemical and physical composition of aerosols while investigating sources of aerosols in the Arctic. The main instrument used in this research has been the state...

  20. Prenatal Exposure to Carbon Black (Printex 90)

    DEFF Research Database (Denmark)

    Jackson, Petra; Vogel, Ulla; Wallin, Håkan

    2011-01-01

    Maternal pulmonary exposure to ultrafine particles during pregnancy may affect the health of the child. Developmental toxicity of carbon black (Printex 90) nanoparticles was evaluated in a mouse model. Time-mated mice were intratracheally instilled with Printex 90 dispersed in Millipore water on ...... on gestation days (GD) 7, 10, 15 and 18, with total doses of 11, 54 and 268 mu g Printex 90/animal. The female offspring prenatally exposed to 268 mu g Printex 90/animal displayed altered habituation pattern during the Open field test....

  1. Electromagnetic properties of carbon black and barium titanate composite materials

    International Nuclear Information System (INIS)

    Wang Guiqin; Chen Xiaodong; Duan Yuping; Liu Shunhua

    2008-01-01

    Nanocrystalline carbon black/barium titanate compound particle (CP) was synthesized by sol-gel method. The phase structure and morphology of compound particle were investigated by X-ray diffraction (XRD), transmission electron microscope (TEM) and Raman spectrum measurements, the electroconductivity was test by trielectrode arrangement and the precursor powder was followed by differential scanning calorimetric measurements (DSC) and thermal gravimetric analysis (TGA). In addition, the complex relative permittivity and permeability of compound particle were investigated by reflection method. The compound particle/epoxide resin composite (CP/EP) with different contents of CP were measured. The results show barium titanate crystal is tetragonal phase and its grain is oval shape with 80-100 nm which was coated by carbon black film. As electromagnetic (EM) complex permittivity, permeability and reflection loss (RL) shown that the compound particle is mainly a kind of electric and dielectric lossy materials and exhibits excellent microwave absorption performance in the X- and Ku-bands

  2. Optics of Water Cloud Droplets Mixed with Black-Carbon Aerosols

    Science.gov (United States)

    Mishchenko, Michael I.; Liu, Li; Cairns, Brian; Mackowski, Daniel W.

    2014-01-01

    We use the recently extended superposition T-matrix method to calculate scattering and absorption properties of micrometer-sized water droplets contaminated by black carbon. Our numerically exact results reveal that, depending on the mode of soot-water mixing, the soot specific absorption can vary by a factor exceeding 6.5. The specific absorption is maximized when the soot material is quasi-uniformly distributed throughout the droplet interior in the form of numerous small monomers. The range of mixing scenarios captured by our computations implies a wide range of remote sensing and radiation budget implications of the presence of black carbon in liquid-water clouds. We show that the popular Maxwell-Garnett effective-medium approximation can be used to calculate the optical cross sections, single-scattering albedo, and asymmetry parameter for the quasi-uniform mixing scenario, but is likely to fail in application to other mixing scenarios and in computations of the elements of the scattering matrix.

  3. Effect of silica concentration on electrical conductivity of epoxy resin-carbon black-silica nanocomposites

    International Nuclear Information System (INIS)

    Zhang Wei; Blackburn, Richard S.; Dehghani-Sanij, Abbas A.

    2007-01-01

    Electrical properties of nanocomposites are determined by the conductive paths of carbon black and influenced by a 'network' of silica. With increasing content of silica, carbon black (CB) particles are optimally dispersed, contributing to the generation of a conductive network between CB particles via direct particle contact and a tunneling effect; maximum conductivity for the epoxy resin-CB-silica nanocomposite described herein occurs at a ratio of 0.6:1.0 (SiO 2 :CB). As a non-conductive component, excessive silica will prevent electron flow, giving rise to low conductivity

  4. The effects of additional black carbon on Arctic sea ice surface albedo: variation with sea ice type and snow cover

    OpenAIRE

    A. A. Marks; M. D. King

    2013-01-01

    Black carbon in sea ice will decrease sea ice surface albedo through increased absorption of incident solar radiation, exacerbating sea ice melting. Previous literature has reported different albedo responses to additions of black carbon in sea ice and has not considered how a snow cover may mitigate the effect of black carbon in sea ice. Sea ice is predominately snow covered. Visible light absorption and light scattering coefficients are calculated for a typical first year and multi-y...

  5. Relationship between Black Carbon and heavy traffic in São Paulo, Brazil

    Science.gov (United States)

    Miranda, R. M.; Perez-Martinez, P.; Ribeiro, F. N. D.; Andrade, M. D. F.

    2015-12-01

    Carbonaceous aerosols play an important role in air quality, human health and global climate change. Black Carbon (BC) can be considered the most efficient light absorber in the visible spectrum and is mainly found in the fine fraction of aerosol. Typically is emitted by incomplete combustion of fossil fuels related to traffic, industrial processes and biomass burning. São Paulo Metropolitan Area (SPMA) with more than 19 million inhabitants, 7 million vehicles, as well as the major industrial and technological park of the country, has high concentrations of air pollutants, especially in the winter and vehicles are considered the principal source of particles emitted to the atmosphere. Since November 2014, Black Carbon and PM2.5 are being monitored using a MAAP (Multi Angle Absorption Photometer) Thermo 5012 and a Dust Trak DRX-8533 TSI in the East Campus of University of São Paulo, close to important highways and also to the largest airport of Brazil (Guarulhos Airport). Average BC concentration was 1.7 μg/m3 with some peaks above 17.0 μg/m3 and for PM2.5 average was 10.2 μg/m3. Particle concentrations reached values greater than the air quality standard (60 μg/m3) in the winter months. Winds coming from the East direction predominate. Traffic restrictions to heavy duty vehicles in the road-rings next to the sampling site during some hours of the day are the responsible for the daily BC and PM2.5 behavior (figure below), where high concentrations occur early in the morning and late at night, when heavy diesel vehicles are released for transit. Seasonal variations are different for BC and PM2.5 due to local sources of BC and meteorological conditions that have more influence on the particles. The weekly variation indicates that concentrations are lower on Sundays and higher from Tuesday to Thursday. Emission factors for BC were calculated based on traffic information.

  6. Centennial black carbon turnover observed in a Russia steppe soil

    Energy Technology Data Exchange (ETDEWEB)

    Hammes, K.; Torn, M.S.; Lapenas, A.G.; Schmidt, M.W.I.

    2008-09-15

    Black carbon (BC), from incomplete combustion of fuels and biomass, has been considered highly recalcitrant and a substantial sink for carbon dioxide. Recent studies have shown that BC can be degraded in soils. We use two soils with very low spatial variability sampled 100 years apart in a Russian steppe preserve to generate the first whole-profile estimate of BC stocks and turnover in the field. Quantities of fire residues in soil changed significantly over a century. Black carbon stock was 2.5 kg m{sup -2}, or about 7-10% of total organic C in 1900. With cessation of biomass burning, BC stocks decreased 25% over a century, which translates into a centennial soil BC turnover (293 years best estimate; range 182-541 years), much faster than so-called inert or passive carbon in ecosystem models. The turnover time presented here is for loss by all processes, namely decomposition, leaching, and erosion, although the latter two were probably insignificant in this case. Notably, at both time points, the peak BC stock was below 30 cm, a depth interval, which is not typically accounted for. Also, the quality of the fire residues changed with time, as indicated by the use benzene poly carboxylic acids (BPCA) as molecular markers. The proportions of less-condensed (and thus more easily degradable) BC structures decreased, whereas the highly condensed (and more recalcitrant) BC structures survived unchanged over the 100-year period. Our results show that BC cannot be assumed chemically recalcitrant in all soils, and other explanations for very old soil carbon are needed.

  7. ESR study on the interaction between carbon blacks and oxygen molecules; ESR ho ni yoru carbon black to sanso bunshi tono sogo sayo no kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Okazaki, M.; Toriyama, K.; Konishi, Y. [National Industrial Research Institute of Nagoya, Nagoya (Japan)

    2000-02-24

    Interaction between carbon blacks and oxygen molecules has been studied by means of electron spin resonance (ESR) spectroscopy. The ESR spectra of the carbon blacks appears at the g-value of free spin, which are contributed by both isolated electrons and conduction electrons. Upon introducing oxygen to the system the ESR linewidth was broadened in proportion to the partial pressure of oxygen. In case of lampblack (LB 101, Degussa) the interaction was not so strong that it took a tong time at 77K for the linewidth to reach the maxmum value. In case of gassblack (P 140 V, Degussa), on the other hand, the oxygen was easily adsorbed at 298K and the linewidth at 77K became its maximum immediately after cooling. The number of unpaired electrons decreased when the system was kept at 298 K and the decrease was prominent for the local spins. These phenomena have been explained with a simple band model for the electron. (author)

  8. Kinetic Modeling of the Reaction Rate for Quartz and Carbon Black Pellet

    Science.gov (United States)

    Li, Fei; Tangstad, Merete

    2018-06-01

    The kinetic modeling for the carbothermal reduction reaction rate in quartz and carbon black pellets is studied at different temperatures, under varying CO partial pressures in ambient atmosphere, varying carbon contents, different quartz particle sizes, and different crucible opening areas. Carbon black is produced by the cracking of natural gas. The activation energy of the SiC-producing step was determined to be 594 kJ/mol. The averaged pre-exponential factor A obtained from 1898 K, 1923 K, and 1948 K (1625 °C, 1650 °C, and 1675 °C) is 2.62E+16 min-1. The reaction rate of the gas-solid interface factor, fix-C content ( X fix-C), temperature ( T), and CO partial pressure ( X CO) can be expressed as follows: {{d/pct}}{{{d}t}} = (1 - 0.40 × X_{{{fix} - C}}^{ - 0.86} × {pct}) × 2.62 × 10^{16} × \\exp ( { - 594000/RT} ) × (2.6 - 0.015 × X_{co} ).

  9. Polymer-carbon black composite sensors in an electronic nose for air-quality monitoring

    Science.gov (United States)

    Ryan, M. A.; Shevade, A. V.; Zhou, H.; Homer, M. L.

    2004-01-01

    An electronic nose that uses an array of 32 polymer-carbon black composite sensors has been developed, trained, and tested. By selecting a variety of chemical functionalities in the polymers used to make sensors, it is possible to construct an array capable of identifying and quantifying a broad range of target compounds, such as alcohols and aromatics, and distinguishing isomers and enantiomers (mirror-image isomers). A model of the interaction between target molecules and the polymer-carbon black composite sensors is under development to aid in selecting the array members and to enable identification of compounds with responses not stored in the analysis library.

  10. Silurian and Devonian source rocks and crude oils from the western part of Libya: Organic geochemistry, palynology and carbon stratigraphy

    NARCIS (Netherlands)

    Elkelani, Mohamed M.A.

    2015-01-01

    The Early Silurian “hot” shales and Late Devonian black shales are major regional oil and gas source rocks in North Africa. Their deposition probably played a major role in global carbon cycling in general because of the large areas of the ocean affected. Comparing the Libyan δ13C record with

  11. Variability in and agreement between modeled and personal continuously measured black carbon levels using novel smartphone and sensor technologies.

    Science.gov (United States)

    Nieuwenhuijsen, Mark J; Donaire-Gonzalez, David; Rivas, Ioar; de Castro, Montserrat; Cirach, Marta; Hoek, Gerard; Seto, Edmund; Jerrett, Michael; Sunyer, Jordi

    2015-03-03

    Novel technologies, such as smartphones and small personal continuous air pollution sensors, can now facilitate better personal estimates of air pollution in relation to location. Such information can provide us with a better understanding about whether and how personal exposures relate to residential air pollution estimates, which are normally used in epidemiological studies. The aims of this study were to examine (1) the variability in personal air pollution levels during the day and (2) the relationship between modeled home and school estimates and continuously measured personal air pollution exposure levels in different microenvironments (e.g., home, school, and commute). We focused on black carbon as an indicator of traffic-related air pollution. We recruited 54 school children (aged 7-11) from 29 different schools around Barcelona as part of the BREATHE study, an epidemiological study of the relation between air pollution and brain development. For 2 typical week days during 2012-2013, the children were given a smartphone with CalFit software to obtain information on their location and physical activity level and a small sensor, the micro-aethalometer model AE51, to measure their black carbon levels simultaneously and continuously. We estimated their home and school exposure to PM2.5 filter absorbance, which is well-correlated with black carbon, using a temporally adjusted PM2.5 absorbance land use regression (LUR) model. We found considerable variation in the black carbon levels during the day, with the highest levels measured during commuting periods (geometric mean = 2.8 μg/m(3)) and the lowest levels at home (geometric mean = 1.3 μg/m(3)). Hourly temporally adjusted LUR model estimates for the home and school showed moderate to good correlation with measured personal black carbon levels at home and school (r = 0.59 and 0.68, respectively) and lower correlation with commuting trips (r = 0.32 and 0.21, respectively). The correlation between modeled home

  12. PM2.5 and aerosol black carbon in Suva, Fiji

    Science.gov (United States)

    Isley, C. F.; Nelson, P. F.; Taylor, M. P.; Mani, F. S.; Maata, M.; Atanacio, A.; Stelcer, E.; Cohen, D. D.

    2017-02-01

    Concentrations of particulate air pollution in Suva, Fiji, have been largely unknown and consequently, current strategies to reduce health risk from air pollution in Suva are not targeted effectively. This lack of air quality data is common across the Pacific Island Countries. A monitoring study, during 2014 and 2015, has characterised the fine particulate air quality in Suva, representing the most detailed study to date of fine aerosol air pollutants for the Pacific Islands; with sampling at City, Residential (Kinoya) and Background (Suva Point) sites. Meteorology for Suva, as it relates to pollutant dispersion for this period of time, has also been analysed. The study design enables the contribution of maritime air and the anthropogenic emissions to be carefully distinguished from each other and separately characterised. Back trajectory calculations show that a packet of air sampled at the Suva City site has typically travelled 724 km in the 24-h prior to sampling, mainly over open ocean waters; inferring that pollutants would also be rapidly transported away from Suva. For fine particulates, Suva City reported a mid-week PM2.5 of 8.6 ± 0.4 μg/m3, averaged over 13-months of gravimetric sampling. Continuous monitoring (Osiris laser photometer) suggests that some areas of Suva may experience levels exceeding the WHO PM2.5 guideline of 10 μg/m3, however, compared to other countries, Fiji's PM2.5 is low. Peak aerosol particulate levels, at all sites, were experienced at night-time, when atmospheric conditions were least favourable to dispersion of air pollutants. Suva's average ambient concentrations of black carbon in PM2.5, 2.2 ± 0.1 μg/m3, are, however, similar to those measured in much larger cities. With any given parcel of air spending only seven minutes, on average, over the land area of Suva Peninsula, these black carbon concentrations are indicative that significant combustion emissions occur within Suva. Many other communities in the Pacific Islands

  13. A methodology for calculating transport emissions in cities with limited traffic data: Case study of diesel particulates and black carbon emissions in Murmansk.

    Science.gov (United States)

    Kholod, N; Evans, M; Gusev, E; Yu, S; Malyshev, V; Tretyakova, S; Barinov, A

    2016-03-15

    This paper presents a methodology for calculating exhaust emissions from on-road transport in cities with low-quality traffic data and outdated vehicle registries. The methodology consists of data collection approaches and emission calculation methods. For data collection, the paper suggests using video survey and parking lot survey methods developed for the International Vehicular Emissions model. Additional sources of information include data from the largest transportation companies, vehicle inspection stations, and official vehicle registries. The paper suggests using the European Computer Programme to Calculate Emissions from Road Transport (COPERT) 4 model to calculate emissions, especially in countries that implemented European emissions standards. If available, the local emission factors should be used instead of the default COPERT emission factors. The paper also suggests additional steps in the methodology to calculate emissions only from diesel vehicles. We applied this methodology to calculate black carbon emissions from diesel on-road vehicles in Murmansk, Russia. The results from Murmansk show that diesel vehicles emitted 11.7 tons of black carbon in 2014. The main factors determining the level of emissions are the structure of the vehicle fleet and the level of vehicle emission controls. Vehicles without controls emit about 55% of black carbon emissions. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Highly Loaded Carbon Black Supported Pt Catalysts for Fuel Cells

    Czech Academy of Sciences Publication Activity Database

    Kaluža, Luděk; Larsen, M.J.; Zdražil, Miroslav; Gulková, Daniela; Vít, Zdeněk; Šolcová, Olga; Soukup, Karel; Koštejn, Martin; Bonde, J.L.; Maixnerová, Lucie; Odgaard, M.

    2015-01-01

    Roč. 256, NOV 1 (2015), s. 375-383 ISSN 0920-5861 R&D Projects: GA MŠk(CZ) 7HX13003 EU Projects: European Commission(XE) 303466 - IMMEDIATE Institutional support: RVO:67985858 Keywords : carbon black * fuell cell * electrocatalyst Subject RIV: CI - Industrial Chemistry , Chemical Engineering Impact factor: 4.312, year: 2015

  15. Centennial black carbon turnover observed in a Russian steppe soil

    Directory of Open Access Journals (Sweden)

    K. Hammes

    2008-09-01

    Full Text Available Black carbon (BC, from incomplete combustion of fuels and biomass, has been considered highly recalcitrant and a substantial sink for carbon dioxide. Recent studies have shown that BC can be degraded in soils. We use two soils with very low spatial variability sampled 100 years apart in a Russian steppe preserve to generate the first whole-profile estimate of BC stocks and turnover in the field. Quantities of fire residues in soil changed significantly over a century. Black carbon stock was 2.5 kg m−2, or about 7–10% of total organic C in 1900. With cessation of biomass burning, BC stocks decreased 25% over a century, which translates into a centennial soil BC turnover (293 years best estimate; range 182–541 years, much faster than so-called inert or passive carbon in ecosystem models. The turnover time presented here is for loss by all processes, namely decomposition, leaching, and erosion, although the latter two were probably insignificant in this case. Notably, at both time points, the peak BC stock was below 30 cm, a depth interval, which is not typically accounted for. Also, the quality of the fire residues changed with time, as indicated by the use benzene polycarboxylic acids (BPCA as molecular markers. The proportions of less-condensed (and thus more easily degradable BC structures decreased, whereas the highly condensed (and more recalcitrant BC structures survived unchanged over the 100-year period. Our results show that BC cannot be assumed chemically recalcitrant in all soils, and other explanations for very old soil carbon are needed.

  16. A global gas flaring black carbon emission rate dataset from 1994 to 2012

    Science.gov (United States)

    Huang, Kan; Fu, Joshua S.

    2016-11-01

    Global flaring of associated petroleum gas is a potential emission source of particulate matters (PM) and could be notable in some specific regions that are in urgent need of mitigation. PM emitted from gas flaring is mainly in the form of black carbon (BC), which is a strong short-lived climate forcer. However, BC from gas flaring has been neglected in most global/regional emission inventories and is rarely considered in climate modeling. Here we present a global gas flaring BC emission rate dataset for the period 1994-2012 in a machine-readable format. We develop a region-dependent gas flaring BC emission factor database based on the chemical compositions of associated petroleum gas at various oil fields. Gas flaring BC emission rates are estimated using this emission factor database and flaring volumes retrieved from satellite imagery. Evaluation using a chemical transport model suggests that consideration of gas flaring emissions can improve model performance. This dataset will benefit and inform a broad range of research topics, e.g., carbon budget, air quality/climate modeling, and environmental/human exposure.

  17. Use of submicron carbon filaments in place of carbon black as a porous reduction electrode in lithium batteries with a catholyte comprising bromine chloride in thionyl chloride

    Energy Technology Data Exchange (ETDEWEB)

    Frysz, C.A. [Wilson Greatbatch, Ltd., Clarence, NY (United States); Shui, X.; Chung, D.D.L. [State Univ. of New York, Buffalo, NY (United States). Composite Materials Research Lab.

    1995-12-31

    Submicron carbon filaments used in place of carbon black as porous reduction electrodes in carbon limited lithium batteries in plate and jellyroll configurations with the BCX (bromine chloride in thionyl chloride) catholyte gave a specific capacity (at 2 V cut-off) of up to 8,700 mAh/g carbon, compared to a value of up to 2,900 mAh/g carbon for carbon black. The high specific capacity per g carbon (demonstrating superior carbon efficiency) for the filament electrode is partly due to the filaments` processability into sheets as thin as 0.2 mm with good porosity and without a binder, and partly due to the high catholyte absorptivity and high rate of catholyte absorption of the filament electrode.

  18. Long-range transported dissolved organic matter, ions and black carbon deposited on Central Asian snow covered glaciers

    Science.gov (United States)

    Schmale, Julia; Kang, Shichang; Peltier, Richard

    2014-05-01

    Ninety percent of the Central Asian population depend on water precipitated in the mountains stored in glaciers and snow cover. Accelerated melting of the snow and ice can be induced by the deposition of airborne impurities such as mineral dust, black carbon and co-emitted species leading to significant reductions of the surface albedo. However, Central Asia is a relatively understudied region and data on the source regions, chemical and microphysical characteristics as well as modelling studies of long-range transported air pollution and dust to the Tien Shan mountains is very scarce. We studied the atmospheric aerosol deposited most likely between summer 2012 and summer 2013on three different glaciers in the Kyrgyz Republic. Samples were taken from four snow pits on the glaciers Abramov (2 pits, 39.59 °N, 71.56 °E, 4390 m elevation, 240 cm deep, and 39.62°N, 71.52 °E, 4275 m elevation, 125 cm deep), Ak-Shiirak (41.80 °N, 78.18 °E, 4325 m elevation, 75 cm deep) and Suek (41.78 °N, 77.75 °E, 4341 m elevation, 200 cm deep). The latter two glaciers are located roughly within 6 and 38 km of an operating gold mine. The snow was analyzed for black carbon, ions, metals and organic carbon. We here focus on the results of inorganic ion measurements and organic carbon speciation based on analysis with an Aerodyne high-resolution time-of-flight aerosol spectrometer (HR-ToF-AMS) and potential pollution sources that can be deduced from the chemical information as well as back trajectories. Average contributions of snow impurities measured by the HR-ToF-AMS were dominated by organic carbon. Relative concentrations of organic carbon, sulfate, nitrate and ammonium in snow were 86 %, 3 %, 9 % and 2 % respectively for Abramov, 92 %, 1 %, 5 % and 1 % for Suek, and 95 %, 1 %, 3 % and 1 % for Ak-Shiirak. Generally, impurities on Suek and Ak-Shiirak were three and five times higher than on Abramov. Mass concentrations of organic carbon were on average 6 times higher in samples

  19. Airborne black carbon concentrations over an urban region in western India-temporal variability, effects of meteorology, and source regions.

    Science.gov (United States)

    Bapna, Mukund; Sunder Raman, Ramya; Ramachandran, S; Rajesh, T A

    2013-03-01

    This study characterizes over 5 years of high time resolution (5 min), airborne black carbon (BC) concentrations (July 2003 to December 2008) measured over Ahmedabad, an urban region in western India. The data were used to obtain different time averages of BC concentrations, and these averages were then used to assess the diurnal, seasonal, and annual variability of BC over the study region. Assessment of diurnal variations revealed a strong association between BC concentrations and vehicular traffic. Peaks in BC concentration were co-incident with the morning (0730 to 0830, LST) and late evening (1930 to 2030, LST) rush hour traffic. Additionally, diurnal variability in BC concentrations during major festivals (Diwali and Dushera during the months of October/November) revealed an increase in BC concentrations due to fireworks displays. Maximum half hourly BC concentrations during the festival days were as high as 79.8 μg m(-3). However, the high concentrations rapidly decayed suggesting that local meteorology during the festive season was favorable for aerosol dispersion. A multiple linear regression (MLR) model with BC as the dependent variable and meteorological parameters as independent variables was fitted. The variability in temperature, humidity, wind speed, and wind direction accounted for about 49% of the variability in measured BC concentrations. Conditional probability function (CPF) analysis was used to identify the geographical location of local source regions contributing to the effective BC measured (at 880 nm) at the receptor site. The east north-east (ENE) direction to the receptor was identified as a major source region. National highway (NH8) and two coal-fired thermal power stations (at Gandhinagar and Sabarmati) were located in the identified direction, suggesting that local traffic and power plant emissions were likely contributors to the measured BC.

  20. Nanoscale Interactions between Engineered Nanomaterials and Black Carbon (Biochar) in Soil

    Science.gov (United States)

    An understanding of the interactions between engineered nanomaterials (NMs) and soil constituents, and a comprehension of how these interactions may affect biological uptake and toxicity are currently lacking. Charcoal black carbon is a normal constituent of soils due to fire history, and can be pre...

  1. Binder-Free and Carbon-Free Nanoparticle Batteries: A Method for Nanoparticle Electrodes without Polymeric Binders or Carbon Black

    KAUST Repository

    Ha, Don-Hyung; Islam, Mohammad A.; Robinson, Richard D.

    2012-01-01

    In this work, we have developed a new fabrication method for nanoparticle (NP) assemblies for Li-ion battery electrodes that require no additional support or conductive materials such as polymeric binders or carbon black. By eliminating

  2. Properties of black carbon and other insoluble light-absorbing particles in seasonal snow of northwestern China

    Science.gov (United States)

    Pu, Wei; Wang, Xin; Wei, Hailun; Zhou, Yue; Shi, Jinsen; Hu, Zhiyuan; Jin, Hongchun; Chen, Quanliang

    2017-05-01

    A large field campaign was conducted and 284 snow samples were collected at 38 sites in Xinjiang Province and 6 sites in Qinghai Province across northwestern China from January to February 2012. A spectrophotometer combined with chemical analysis was used to measure the insoluble light-absorbing particles (ILAPs) and chemical components in seasonal snow. The results indicate that the cleanest snow was found in northeastern Xinjiang along the border of China, and it presented an estimated black carbon (CBCest) of approximately 5 ng g-1. The dirtiest snow presented a CBCest of approximately 450 ng g-1 near industrial cities in Xinjiang. Overall, the CBCest of most of the snow samples collected in this campaign was in the range of 10-150 ng g-1. Vertical variations in the snowpack ILAPs indicated a probable shift in emission sources with the progression of winter. An analysis of the fractional contributions to absorption implied that organic carbon (OC) dominated the 450 nm absorption in Qinghai, while the contributions from BC and OC were comparable in Xinjiang. Finally, a positive matrix factorization (PMF) model was run to explore the sources of particulate light absorption, and the results indicated an optimal three-factor/source solution that included industrial pollution, biomass burning, and soil dust.

  3. Optimising carbon and nitrogen sources for Azotobacter ...

    African Journals Online (AJOL)

    The present work deals with selecting and optimization of carbon and nitrogen sources for producing biomass from Azotobacter chroococcum. Four carbon sources (glucose, sucrose, manitol and sodium benzoate) and four nitrogen sources (yeast extract, meat extract, NH4Cl and (NH4)2SO4) were evaluated during the first ...

  4. An analysis of the black crusts from the Seville Cathedral: A challenge to deepen the understanding of the relationships among microstructure, microchemical features and pollution sources

    International Nuclear Information System (INIS)

    Ruffolo, Silvestro A.; Comite, Valeria; La Russa, Mauro F.; Belfiore, Cristina M.; Barca, Donatella; Bonazza, Alessandra; Crisci, Gino M.; Pezzino, Antonino

    2015-01-01

    The Cathedral of Seville is one of the most important buildings in the whole of southern Spain. It suffers, like most of the historical buildings located in urban environments, from several degradation phenomena related to the high pollution level. Undoubtedly, the formation of black crusts plays a crucial role in the decay of the stone materials belonging to the church. Their formation occurs mainly on carbonate building materials, whose interaction with a sulfur oxide-enriched atmosphere leads to the transformation of calcium carbonate (calcite) into calcium sulfate dihydrate (gypsum) which, together with embedded carbonaceous particles, forms the black crusts on the stone surface. To better understand the composition and the formation dynamics of this degradation product and to identify the pollutant sources and evaluate their impact on the stone material, an analytical study was carried out on the black crust samples collected from different areas of the building. For a complete characterization of the black crusts, several techniques were used, including laser ablation inductively coupled plasma mass spectrometry, Fourier transform infrared spectroscopy, micro infrared spectroscopy, optical and scanning electron microscopy. This battery of tests provided information about the nature and distribution of the mineralogical phases and the elements within the crusts and the crust-substrate interface, contributing to the identification of the major pollution sources responsible for the deterioration of the monument over time. In addition, the results revealed a relation among the height of sampling, the surface exposure and the concentration of heavy metals. Finally, information has been provided about the origin of the concentration gradients of some metals. - Highlights: • Black crusts from the Cathedral of Seville have been studied. • The impact of the pollution on the Cathedral of Seville has been assessed. • A geochemical study has been performed on black

  5. An analysis of the black crusts from the Seville Cathedral: A challenge to deepen the understanding of the relationships among microstructure, microchemical features and pollution sources

    Energy Technology Data Exchange (ETDEWEB)

    Ruffolo, Silvestro A., E-mail: silvestro.ruffolo@unical.it [Università della Calabria, Dipartimento di Biologia, Ecologia e Scienze della Terra (DiBEST), Via Pietro Bucci 87036, Arcavacata di Rende, CS (Italy); Comite, Valeria [Università della Calabria, Dipartimento di Biologia, Ecologia e Scienze della Terra (DiBEST), Via Pietro Bucci 87036, Arcavacata di Rende, CS (Italy); Dipartimento di Scienze Biologiche, Geologiche e Ambientali–Sezione di Scienze della Terra, Università di Catania, Corso Italia 57, 95129 Catania (Italy); La Russa, Mauro F. [Università della Calabria, Dipartimento di Biologia, Ecologia e Scienze della Terra (DiBEST), Via Pietro Bucci 87036, Arcavacata di Rende, CS (Italy); Belfiore, Cristina M. [Università della Calabria, Dipartimento di Biologia, Ecologia e Scienze della Terra (DiBEST), Via Pietro Bucci 87036, Arcavacata di Rende, CS (Italy); Dipartimento di Scienze Biologiche, Geologiche e Ambientali–Sezione di Scienze della Terra, Università di Catania, Corso Italia 57, 95129 Catania (Italy); Barca, Donatella [Università della Calabria, Dipartimento di Biologia, Ecologia e Scienze della Terra (DiBEST), Via Pietro Bucci 87036, Arcavacata di Rende, CS (Italy); Bonazza, Alessandra [Istituto di Scienze dell' Atmosfera e del Clima, ISAC-CNR, Via Gobetti 101, 40129 Bologna (Italy); Crisci, Gino M. [Università della Calabria, Dipartimento di Biologia, Ecologia e Scienze della Terra (DiBEST), Via Pietro Bucci 87036, Arcavacata di Rende, CS (Italy); Pezzino, Antonino [Dipartimento di Scienze Biologiche, Geologiche e Ambientali–Sezione di Scienze della Terra, Università di Catania, Corso Italia 57, 95129 Catania (Italy); and others

    2015-01-01

    The Cathedral of Seville is one of the most important buildings in the whole of southern Spain. It suffers, like most of the historical buildings located in urban environments, from several degradation phenomena related to the high pollution level. Undoubtedly, the formation of black crusts plays a crucial role in the decay of the stone materials belonging to the church. Their formation occurs mainly on carbonate building materials, whose interaction with a sulfur oxide-enriched atmosphere leads to the transformation of calcium carbonate (calcite) into calcium sulfate dihydrate (gypsum) which, together with embedded carbonaceous particles, forms the black crusts on the stone surface. To better understand the composition and the formation dynamics of this degradation product and to identify the pollutant sources and evaluate their impact on the stone material, an analytical study was carried out on the black crust samples collected from different areas of the building. For a complete characterization of the black crusts, several techniques were used, including laser ablation inductively coupled plasma mass spectrometry, Fourier transform infrared spectroscopy, micro infrared spectroscopy, optical and scanning electron microscopy. This battery of tests provided information about the nature and distribution of the mineralogical phases and the elements within the crusts and the crust-substrate interface, contributing to the identification of the major pollution sources responsible for the deterioration of the monument over time. In addition, the results revealed a relation among the height of sampling, the surface exposure and the concentration of heavy metals. Finally, information has been provided about the origin of the concentration gradients of some metals. - Highlights: • Black crusts from the Cathedral of Seville have been studied. • The impact of the pollution on the Cathedral of Seville has been assessed. • A geochemical study has been performed on black

  6. Response behavior of an epoxy resin/amine curing agent/carbon black composite film to various solvents

    Energy Technology Data Exchange (ETDEWEB)

    Luo Yanling [School of Chemistry and Materials Science, Shaanxi Normal University, Xi' an 710062 (China)]. E-mail: luoyl0401@yahoo.com.cn; Li Zhanqing [School of Chemistry and Materials Science, Shaanxi Normal University, Xi' an 710062 (China); Lan Wenxiang [School of Chemistry and Materials Science, Shaanxi Normal University, Xi' an 710062 (China)

    2007-04-25

    A novel polymer based sensitive film was prepared from thermosetting epoxy resins (EP) filled with carbon blacks. The curing reaction of amine curing agents with epoxy resins and the response of the curing resultants to solvent vapors were dealt with. The influence of the types and content of carbon blacks and curing agents, and curing temperatures and time on curing reactions and response selectivity of the conductive films were investigated. The structural characterization was conducted on a Fourier transform infrared spectrophotometer (FTIR). The results indicated that the conductive films showed high response selectivity to polar solvent vapors, especially to chloroform vapor, while no response was observed in non-polar solvent vapors. The responsivity of the film increased with the decreased carbon black contents. The film filled with acetylene carbon black gave an optimal response, with responsivity of about 700 times. The response performances were improved with the amount of curing agents increased, and an optimal response appeared at the amount of the curing agent of 8%. The film's responsivity was remarkably enhanced, the reversibility property, however, rapidly declined in the order of diethyleneltriamine < triethylenetetramine < ethylenediamine. The curing reaction tended to complete with the curing temperature elevated and the curing time prolonged. But the response performance dropped because of over cross-linking as the temperature was too high or the time was too long.

  7. Response behavior of an epoxy resin/amine curing agent/carbon black composite film to various solvents

    International Nuclear Information System (INIS)

    Luo Yanling; Li Zhanqing; Lan Wenxiang

    2007-01-01

    A novel polymer based sensitive film was prepared from thermosetting epoxy resins (EP) filled with carbon blacks. The curing reaction of amine curing agents with epoxy resins and the response of the curing resultants to solvent vapors were dealt with. The influence of the types and content of carbon blacks and curing agents, and curing temperatures and time on curing reactions and response selectivity of the conductive films were investigated. The structural characterization was conducted on a Fourier transform infrared spectrophotometer (FTIR). The results indicated that the conductive films showed high response selectivity to polar solvent vapors, especially to chloroform vapor, while no response was observed in non-polar solvent vapors. The responsivity of the film increased with the decreased carbon black contents. The film filled with acetylene carbon black gave an optimal response, with responsivity of about 700 times. The response performances were improved with the amount of curing agents increased, and an optimal response appeared at the amount of the curing agent of 8%. The film's responsivity was remarkably enhanced, the reversibility property, however, rapidly declined in the order of diethyleneltriamine < triethylenetetramine < ethylenediamine. The curing reaction tended to complete with the curing temperature elevated and the curing time prolonged. But the response performance dropped because of over cross-linking as the temperature was too high or the time was too long

  8. Structural, mechanical and electrical characterization of epoxy-amine/carbon black nanonocomposites

    Directory of Open Access Journals (Sweden)

    2008-05-01

    Full Text Available This work presents an insight into the effect of preparation procedure and the filler content on both electrical and mechanical properties of a nanocomposite system. For the preparation of the nanocomposites diglycidyl ether of bisphenol A (DGEBA was used with triethylenetetramine (TETA as a curing agent. As fillers carbon black (CB nanoparticles with size from 25 to 75 nm were used. The characterization was done using Dynamic Mechanical Analysis (DMA, Dielectric Relaxation Spectroscopy (DRS, Differential Scanning Calorimetry (DSC, Wide Angle X-ray Diffraction (WAXD and electrical conductivity measurements. The dependence of the dynamic mechanical and dielectric parameters (E′, E″, tanδ, ε', ε″, σ and Tg is associated with the filler content and is controlled by the employed curing conditions. An increase in electrical conductivity, which is observed at about 1% w/w of carbon black, indicates the creation of conducting paths and is associated with the Maxwell Wagner Sillars (MWS relaxation, probably due to the formation of aggregated microstructures in the bulk composite..

  9. Rethinking the distinction between black and brown carbon

    Science.gov (United States)

    Adler, G. A.; Franchin, A.; Lamb, K. D.; Manfred, K.; Middlebrook, A. M.; Schwarz, J. P.; Wagner, N.; Washenfelder, R. A.; Womack, C.; Murphy, D. M.

    2017-12-01

    Aerosol radiative properties contribute large uncertainty to modeling of the earth's radiative budget. Black carbon (BC) aerosols originate from combustion processes and substantially contribute to warming and uncertainty - ongoing efforts are focused on reducing their anthropogenic emissions even as their emissions from biomass burning sources, such as wildfire, may increase in the future. Quantifying the radiative effect of BC is challenging, in part due to its association with other light absorbing materials including Brown carbon organic aerosol (BrC) that absorbs primarily blue and ultraviolet light while BC absorbs broadly across the visible. Conventionally BrC is thought of a low volatility spherical particles, distinguishing it from BC, which has a distinctive agglomerate morphology and is refractory at high temperatures. However, the separation of BC and BrC is often operationally defined and dependent on the measurement method. Using measurements of aerosol morphology, mass, absorption, and refractory BC mass content we were able to identify a light absorbing contribution from biomass burning aerosol that does not correspond to either BC or BrC as conventionally defined. Our measurements were collected from realistic biomass burning fires at the Missoula Fire Sciences Laboratory as part of the NOAA FIREX project (2016) and from extensive natural wildfire sampled aloft during NASA SEAC4RS field study (2013). We coin the term Dark Brown Carbon (DBrC) to describe this material, which absorbs broadly across the visible and survives thermal denuding at 250°C but does not incandesce in laser induced incandesce (LII) measurements. DBrC may be an intermediate burning stage product between polycyclic aromatic hydrocarbons (PAHs) and the mature soot. DBrC deserves further study to quantify its abundance and aging in ambient biomass burning plumes, and its relationship to tar balls. Our findings show that more than half of the light absorption in biomass burning

  10. An accurate filter loading correction is essential for assessing personal exposure to black carbon using an Aethalometer.

    Science.gov (United States)

    Good, Nicholas; Mölter, Anna; Peel, Jennifer L; Volckens, John

    2017-07-01

    The AE51 micro-Aethalometer (microAeth) is a popular and useful tool for assessing personal exposure to particulate black carbon (BC). However, few users of the AE51 are aware that its measurements are biased low (by up to 70%) due to the accumulation of BC on the filter substrate over time; previous studies of personal black carbon exposure are likely to have suffered from this bias. Although methods to correct for bias in micro-Aethalometer measurements of particulate black carbon have been proposed, these methods have not been verified in the context of personal exposure assessment. Here, five Aethalometer loading correction equations based on published methods were evaluated. Laboratory-generated aerosols of varying black carbon content (ammonium sulfate, Aquadag and NIST diesel particulate matter) were used to assess the performance of these methods. Filters from a personal exposure assessment study were also analyzed to determine how the correction methods performed for real-world samples. Standard correction equations produced correction factors with root mean square errors of 0.10 to 0.13 and mean bias within ±0.10. An optimized correction equation is also presented, along with sampling recommendations for minimizing bias when assessing personal exposure to BC using the AE51 micro-Aethalometer.

  11. The effect of snow/sea ice type on the response of albedo and light penetration depth (e-folding depth to increasing black carbon

    Directory of Open Access Journals (Sweden)

    A. A. Marks

    2014-09-01

    Full Text Available The optical properties of snow/sea ice vary with age and by the processes they were formed, giving characteristic types of snow and sea ice. The response of albedo and light penetration depth (e-folding depth to increasing mass ratio of black carbon is shown to depend on the snow and sea ice type and the thickness of the snow or sea ice. The response of albedo and e-folding depth of three different types of snow (cold polar snow, wind-packed snow and melting snow and three sea ice (multi-year ice, first-year ice and melting sea ice to increasing mass ratio of black carbon is calculated using a coupled atmosphere–snow/sea ice radiative-transfer model (TUV-snow, over the optical wavelengths of 300–800 nm. The snow and sea ice types are effectively defined by a scattering cross-section, density and asymmetry parameter. The relative change in albedo and e-folding depth of each of the three snow and three sea ice types with increasing mass ratio of black carbon is considered relative to a base case of 1 ng g−1 of black carbon. The relative response of each snow and sea ice type is intercompared to examine how different types of snow and sea ice respond relative to each other. The relative change in albedo of a melting snowpack is a factor of four more responsive to additions of black carbon compared to cold polar snow over a black carbon increase from 1 to 50 ng g−1, while the relative change in albedo of a melting sea ice is a factor of two more responsive to additions of black carbon compared to multi-year ice for the same increase in mass ratio of black carbon. The response of e-folding depth is effectively not dependent on snow/sea ice type. The albedo of sea ice is more responsive to increasing mass ratios of black carbon than snow.

  12. Quantifying immediate radiative forcing by black carbon and organic matter with the Specific Forcing Pulse

    Directory of Open Access Journals (Sweden)

    T. C. Bond

    2011-02-01

    Full Text Available Climatic effects of short-lived climate forcers (SLCFs differ from those of long-lived greenhouse gases, because they occur rapidly after emission and because they depend upon the region of emission. The distinctive temporal and spatial nature of these impacts is not captured by measures that rely on global averages or long time integrations. Here, we propose a simple measure, the Specific Forcing Pulse (SFP, to quantify climate warming or cooling by these pollutants, where we define "immediate" as occurring primarily within the first year after emission. SFP is the amount of energy added to or removed from a receptor region in the Earth-atmosphere system by a chemical species, per mass of emission in a source region. We limit the application of SFP to species that remain in the atmosphere for less than one year. Metrics used in policy discussions, such as total forcing or global warming potential, are easily derived from SFP. However, SFP conveys purely physical information without incurring the policy implications of choosing a time horizon for the global warming potential.

    Using one model (Community Atmosphere Model, or CAM, we calculate values of SFP for black carbon (BC and organic matter (OM emitted from 23 source-region combinations. Global SFP for both atmosphere and cryosphere impacts is divided among receptor latitudes. SFP is usually greater for open-burning emissions than for energy-related (fossil-fuel and biofuel emissions because of the timing of emission. Global SFP for BC varies by about 45% for energy-related emissions from different regions. This variation would be larger except for compensating effects. When emitted aerosol has larger cryosphere forcing, it often has lower atmosphere forcing because of less deep convection and a shorter atmospheric lifetime.

    A single model result is insufficient to capture uncertainty. We develop a best estimate and uncertainties for SFP by combining forcing results from

  13. Sediment pore water distribution coefficients of PCB congeners in enriched black carbon sediment

    International Nuclear Information System (INIS)

    Martinez, Andres; O'Sullivan, Colin; Reible, Danny; Hornbuckle, Keri C.

    2013-01-01

    More than 2300 sediment pore water distribution coefficients (K PCBids ) of 93 polychlorinated biphenyls (PCBs) were measured and modeled from sediments from Indiana Harbor and Ship Canal. K PCBids were calculated from previously reported bulk sediment values and newly analyzed pore water. PCBs in pore waters were measured using SPME PDMS-fiber and ∑PCB ranged from 41 to 1500 ng L −1 . The resulting K PCBids were ∼1 log unit lower in comparison to other reported values. A simple model for the K PCBid consisted of the product of the organic carbon fraction and the octanol–water partition coefficient and provided an excellent prediction for the measured values, with a mean square error of 0.09 ± 0.06. Although black carbon content is very high in these sediments and was expected to play an important role in the distribution of PCBs, no improvement was obtained when a two-carbon model was used. -- Highlights: •PCB sediment-pore water distribution coefficients were measured and modeled. •Distribution coefficients were lower in comparison to other reported values. •Organic carbon fraction times the K OW yielded the best prediction model. •The incorporation of black carbon into a model did not improve the results. -- The organic carbon fraction times the octanol–water partition coefficient yielded the best prediction model for the sediment pore water distribution coefficient of PCBs

  14. T-S criticality of black holes with power Maxwell invariant source

    Science.gov (United States)

    Lin, Ze-Tao; Li, Gu-Qiang; Long, Kun; He, Fang; Mo, Jie-Xiong

    2017-09-01

    In this paper, we show that black holes with PMI source exhibit the T-S criticality and derive the relevant critical physical quantities analytically. The values of critical quantities for the case s≠1 vary from those for the case s=1, showing the effect of PMI field on the critical phenomena of black holes. When qPMI field does not affect the Maxwell equal area law.

  15. Interaction between carboxyl-functionalized carbon black nanoparticles and porous media

    Science.gov (United States)

    Kim, Song-Bae; Kang, Jin-Kyu; Yi, In-Geol

    2015-04-01

    Carbon nanomaterials, such as carbon nanotubes, fullerene, and graphene, have received considerable attention due to their unique physical and chemical characteristics, leading to mass production and widespread application in industrial, commercial, and environmental fields. During their life cycle from production to disposal, however, carbon nanomaterials are inevitably released into water and soil environments, which have resulted in concern about their health and environmental impacts. Carbon black is a nano-sized amorphous carbon powder that typically contains 90-99% elemental carbon. It can be produced from incomplete combustion of hydrocarbons in petroleum and coal. Carbon black is widely used in chemical and industrial products or applications such as ink pigments, coating plastics, the rubber industry, and composite reinforcements. Even though carbon black is strongly hydrophobic and tends to aggregate in water, it can be dispersed in aqueous media through surface functionalization or surfactant use. The aim of this study was therefore to investigate the transport behavior of carboxyl-functionalized carbon black nanoparticles (CBNPs) in porous media. Column experiments were performed for potassium chloride (KCl), a conservative tracer, and CBNPs under saturated flow conditions. Column experiments was conducted in duplicate using quartz sand, iron oxide-coated sand (IOCS), and aluminum oxide-coated sand (AOCS) to examine the effect of metal (Fe, Al) oxide presence on the transport of CBNPs. Breakthrough curves (BTCs) of CBNPs and chloride were obtained by monitoring effluent, and then mass recovery was quantified from these curves. Additionally, interaction energy profiles for CBNP-porous media were calculated using DLVO theory for sphere-plate geometry. The BTCs of chloride had relative peak concentrations ranging from 0.895 to 0.990. Transport parameters (pore-water velocity v, hydrodynamic dispersion coefficient D) obtained by the model fit from the

  16. Tensile properties of carbon black-filled natural rubber latex films using two different approaches of film preparation

    Science.gov (United States)

    Jarkasi, Siti Aisyah; Samsuri, Azemi; Hashim, M. Y. Amir; Kamarun, Dzaraini

    2017-09-01

    A study was structured to investigate the effects of two different approaches of black-filled NRL films preparation on tensile strengths and tensile stress at 100% strain (M100). In the "First Approach", carbon black dispersion was added into the NRL and mixed using mechanical stirrer. Then the black-filled NRL was coagulated with acetic acid and dried to form NR black-filled masterbatch. This black-filled NR masterbatch was then masticated and mixed with other compounding ingredients on the 2-roll mill. In the "Second Approach", carbon black dispersion was mixed with NRL plus all other compounding ingredients using a mechanical stirrer at high mechanical stirring speed (200 rpm) for 3 hrs. Tensile test-pieces from these two rubber specimens were tested according to ISO37. It was observed that the tensile strengths are affected by both methods. In the case of masticated latex masterbatch, the black-filled NRL films gave higher tensile strength (25-27 MPa) as compared to un-masticated black-filled NRL films (11-17 MPa). The optimum amount of filler loading for highest tensile strength in both approaches was 20 phr of carbon black. However these different approaches did not give significant effect to the elongation at break, EB and M100. SEM images of samples prepared from both approaches suggested that the dispersion of filler in the rubber matrix was better in the masticated samples compared to the un-masticated samples. The reason for the difference in the tensile strength between the two black-filled rubbers might be associated with the degree of dispersions and the uniformity of the dispersions within the rubber matrix. The first mixing approach involved high mechanical shearing action during mastication and mixing process on the 2-roll mill. The high shearing actions were able to breakdown filler aggregates efficiently and distributed the dispersed filler uniformly within the rubber matrix. In the second approach, the breakdown of filler aggregates relied on

  17. ANALYSIS OF DEVONIAN BLACK SHALES IN KENTUCKY FOR POTENTIAL CARBON DIOXIDE SEQUESTRATION AND ENHANCED NATURAL GAS PRODUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Brandon C. Nuttall

    2003-10-29

    CO{sub 2} emissions from the combustion of fossil fuels have been linked to global climate change. Proposed carbon management technologies include geologic sequestration of CO{sub 2}. A possible, but untested, sequestration strategy is to inject CO{sub 2} into organic-rich shales. Devonian black shales underlie approximately two-thirds of Kentucky and are thicker and deeper in the Illinois and Appalachian Basin portions of Kentucky than in central Kentucky. The Devonian black shales serve as both the source and trap for large quantities of natural gas; total gas in place for the shales in Kentucky is estimated to be between 63 and 112 trillion cubic feet. Most of this natural gas is adsorbed on clay and kerogen surfaces, analogous to methane storage in coal beds. In coals, it has been demonstrated that CO{sub 2} is preferentially adsorbed, displacing methane. Black shales may similarly desorb methane in the presence of CO{sub 2}. The concept that black, organic-rich Devonian shales could serve as a significant geologic sink for CO{sub 2} is the subject of current research. To accomplish this investigation, drill cuttings and cores were selected from the Kentucky Geological Survey Well Sample and Core Library. Methane and carbon dioxide adsorption analyses are being performed to determine the gas-storage potential of the shale and to identify shale facies with the most sequestration potential. In addition, sidewall core samples are being acquired to investigate specific black-shale facies, their potential CO{sub 2} uptake, and the resulting displacement of methane. Advanced logging techniques (elemental capture spectroscopy) are being investigated for possible correlations between adsorption capacity and geophysical log measurements. For the Devonian shale, average total organic carbon is 3.71 (as received) and mean random vitrinite reflectance is 1.16. Measured adsorption isotherm data range from 37.5 to 2,077.6 standard cubic feet of CO{sub 2} per ton (scf/ton) of

  18. ANALYSIS OF DEVONIAN BLACK SHALES IN KENTUCKY FOR POTENTIAL CARBON DIOXIDE SEQUESTRATION AND ENHANCED NATURAL GAS PRODUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Brandon C. Nuttall

    2004-04-01

    CO{sub 2} emissions from the combustion of fossil fuels have been linked to global climate change. Proposed carbon management technologies include geologic sequestration of CO{sub 2}. A possible, but untested, sequestration strategy is to inject CO{sub 2} into organic-rich shales. Devonian black shales underlie approximately two-thirds of Kentucky and are thicker and deeper in the Illinois and Appalachian Basin portions of Kentucky than in central Kentucky. The Devonian black shales serve as both the source and trap for large quantities of natural gas; total gas in place for the shales in Kentucky is estimated to be between 63 and 112 trillion cubic feet. Most of this natural gas is adsorbed on clay and kerogen surfaces, analogous to methane storage in coal beds. In coals, it has been demonstrated that CO{sub 2} is preferentially adsorbed, displacing methane. Black shales may similarly desorb methane in the presence of CO{sub 2}. The concept that black, organic-rich Devonian shales could serve as a significant geologic sink for CO{sub 2} is the subject of current research. To accomplish this investigation, drill cuttings and cores were selected from the Kentucky Geological Survey Well Sample and Core Library. Methane and carbon dioxide adsorption analyses are being performed to determine the gas-storage potential of the shale and to identify shale facies with the most sequestration potential. In addition, sidewall core samples are being acquired to investigate specific black-shale facies, their potential CO{sub 2} uptake, and the resulting displacement of methane. Advanced logging techniques (elemental capture spectroscopy) are being investigated for possible correlations between adsorption capacity and geophysical log measurements. For the Devonian shale, average total organic carbon is 3.71 percent (as received) and mean random vitrinite reflectance is 1.16. Measured adsorption isotherm data range from 37.5 to 2,077.6 standard cubic feet of CO{sub 2} per ton (scf

  19. ANALYSIS OF DEVONIAN BLACK SHALES IN KENTUCKY FOR POTENTIAL CARBON DIOXIDE SEQUESTRATION AND ENHANCED NATURAL GAS PRODUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Brandon C. Nuttall

    2004-01-01

    CO{sub 2} emissions from the combustion of fossil fuels have been linked to global climate change. Proposed carbon management technologies include geologic sequestration of CO{sub 2}. A possible, but untested, sequestration strategy is to inject CO{sub 2} into organic-rich shales. Devonian black shales underlie approximately two-thirds of Kentucky and are thicker and deeper in the Illinois and Appalachian Basin portions of Kentucky than in central Kentucky. The Devonian black shales serve as both the source and trap for large quantities of natural gas; total gas in place for the shales in Kentucky is estimated to be between 63 and 112 trillion cubic feet. Most of this natural gas is adsorbed on clay and kerogen surfaces, analogous to methane storage in coal beds. In coals, it has been demonstrated that CO{sub 2} is preferentially adsorbed, displacing methane. Black shales may similarly desorb methane in the presence of CO{sub 2}. The concept that black, organic-rich Devonian shales could serve as a significant geologic sink for CO{sub 2} is the subject of current research. To accomplish this investigation, drill cuttings and cores were selected from the Kentucky Geological Survey Well Sample and Core Library. Methane and carbon dioxide adsorption analyses are being performed to determine the gas-storage potential of the shale and to identify shale facies with the most sequestration potential. In addition, sidewall core samples are being acquired to investigate specific black-shale facies, their potential CO{sub 2} uptake, and the resulting displacement of methane. Advanced logging techniques (elemental capture spectroscopy) are being investigated for possible correlations between adsorption capacity and geophysical log measurements. For the Devonian shale, average total organic carbon is 3.71 (as received) and mean random vitrinite reflectance is 1.16. Measured adsorption isotherm data range from 37.5 to 2,077.6 standard cubic feet of CO{sub 2} per ton (scf/ton) of

  20. Sol-gel processed thin-layer ruthenium oxide/carbon black supercapacitors: A revelation of the energy storage issues

    Energy Technology Data Exchange (ETDEWEB)

    Panic, V.V.; Dekanski, A.B.; Stevanovic, R.M. [Institute of Chemistry, Technology and Metallurgy, Department of Electrochemistry, University of Belgrade, Njegoseva 12, Belgrade 125213 (RS)

    2010-07-01

    Hydrous ruthenium oxide/carbon black nanocomposites were prepared by impregnation of the carbon blacks by differently aged inorganic RuO{sub 2} sols, i.e. of different particle size. Commercial Black Pearls 2000 {sup registered} (BP) and Vulcan {sup registered} XC-72 R (XC) carbon blacks were used. Capacitive properties of BP/RuO{sub 2} and XC/RuO{sub 2} composites were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in H{sub 2}SO{sub 4} solution. Capacitance values and capacitance distribution through the composite porous layer were found different if high- (BP) and low- (XC) surface-area carbons are used as supports. The aging time (particle size) of Ru oxide sol as well as the concentration of the oxide solid phase in the impregnating medium influenced the capacitive performance of prepared composites. While the capacitance of BP-supported oxide decreases with the aging time, the capacitive ability of XC-supported oxide is promoted with increasing oxide particle size. The increase in concentration of the oxide solid phase in the impregnating medium caused an improvement of charging/discharging characteristics due to pronounced pseudocapacitance contribution of the increasing amount of inserted oxide. The effects of these variables in the impregnation process on the energy storage capabilities of prepared nanocomposites are envisaged as a result of intrinsic way of population of the pores of carbon material by hydrous Ru oxide particle. (author)

  1. Effects of black carbon on bioturbination-induced benthic fluxes of polychlorinated biphenyls

    NARCIS (Netherlands)

    Koelmans, A.A.; Jonker, M.T.O.

    2011-01-01

    It is unknown whether carbonaceous geosorbents, such as black carbon (BC) affect bioturbation by benthic invertebrates, thereby possibly affecting sediment–water exchange of sediment-bound contaminants. Here, we assess the effects of oil soot on polychlorinated biphenyl (PCB) mass transfer from

  2. ANALYSIS OF DEVONIAN BLACK SHALES IN KENTUCKY FOR POTENTIAL CARBON DIOXIDE SEQUESTRATION AND ENHANCED NATURAL GAS PRODUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Brandon C. Nuttall

    2003-07-28

    CO{sub 2} emissions from the combustion of fossil fuels have been linked to global climate change. Proposed carbon management technologies include geologic sequestration of CO{sub 2}. A possible, but untested, sequestration strategy is to inject CO{sub 2} into organic-rich shales. Devonian black shales underlie approximately two-thirds of Kentucky and are thicker and deeper in the Illinois and Appalachian Basin portions of Kentucky than in central Kentucky. The Devonian black shales serve as both the source and trap for large quantities of natural gas; total gas in place for the shales in Kentucky is estimated to be between 63 and 112 trillion cubic feet. Most of this natural gas is adsorbed on clay and kerogen surfaces, analogous to methane storage in coal beds. In coals, it has been demonstrated that CO{sub 2} is preferentially adsorbed, displacing methane. Black shales may similarly desorb methane in the presence of CO{sub 2}. The concept that black, organic-rich Devonian shales could serve as a significant geologic sink for CO{sub 2} is the subject of current research. To accomplish this investigation, drill cuttings and cores were selected from the Kentucky Geological Survey Well Sample and Core Library. Methane and carbon dioxide adsorption analyses are being performed to determine the gas-storage potential of the shale and to identify shale facies with the most sequestration potential. In addition, sidewall core samples are being acquired to investigate specific black-shale facies, their potential CO{sub 2} uptake, and the resulting displacement of methane. Advanced logging techniques (elemental capture spectroscopy) are being investigated for possible correlations between adsorption capacity and geophysical log measurements. Initial estimates indicate a sequestration capacity of 5.3 billion tons CO{sub 2} in the Lower Huron Member of the Ohio shale in parts of eastern Kentucky and as much as 28 billion tons total in the deeper and thicker portions of the

  3. Hydrothermal, biogenic, and seawater components in metalliferous black shales of the Brooks Range, Alaska: Synsedimentary metal enrichment in a carbonate ramp setting

    Science.gov (United States)

    Slack, John F.; Selby, David; Dumoulin, Julie A.

    2015-01-01

    Trace element and Os isotope data for Lisburne Group metalliferous black shales of Middle Mississippian (early Chesterian) age in the Brooks Range of northern Alaska suggest that metals were sourced chiefly from local seawater (including biogenic detritus) but also from externally derived hydrothermal fluids. These black shales are interbedded with phosphorites and limestones in sequences 3 to 35 m thick; deposition occurred mainly on a carbonate ramp during intermittent upwelling under varying redox conditions, from suboxic to anoxic to sulfidic. Deposition of the black shales at ~335 Ma was broadly contemporaneous with sulfide mineralization in the Red Dog and Drenchwater Zn-Pb-Ag deposits, which formed in a distal marginal basin.Relative to the composition of average black shale, the metalliferous black shales (n = 29) display large average enrichment factors (>10) for Zn (10.1), Cd (11.0), and Ag (20.1). Small enrichments (>2–seawater. Such moderate enrichments, which are common in other metalliferous black shales, suggest wholly marine sources (seawater and biogenic material) for these metals, given similar trends for enrichment factors in organic-rich sediments of modern upwelling zones on the Namibian, Peruvian, and Chilean shelves. The largest enrichment factors for Zn and Ag are much higher (1.4 × 107 and 2.9 × 107, respectively), consistent with an appreciable hydrothermal component. Other metals such as Cu, Pb, and Tl that are concentrated in several black shale samples, and are locally abundant in the Red Dog and Drenchwater Zn-Pb-Ag deposits, may have a partly hydrothermal origin but this cannot be fully established with the available data. Enrichments in Cr (up to 7.8 × 106) are attributed to marine and not hydrothermal processes. The presence in some samples of large enrichments in Eu (up to 6.1 × 107) relative to modern seawater and of small positive Eu anomalies (Eu/Eu* up to 1.12) are considered unrelated to hydrothermal activity, instead

  4. pH-dependence of pesticide adsorption by wheat-residue-derived black carbon.

    Science.gov (United States)

    Yang, Yaning; Chun, Yuan; Sheng, Guangyao; Huang, Minsheng

    2004-08-03

    The potential of black carbon as an adsorbent for pesticides in soils may be strongly influenced by the properties of the adsorbent and pesticides and by the environmental conditions. This study evaluated the effect of pH on the adsorption of diuron, bromoxynil, and ametryne by a wheat (Triticum aestivum L.) residue derived black carbon (WC) as compared to a commercial activated carbon (AC). The pH drift method indicated that WC had a point of zero charge of 4.2, much lower than that of 7.8 for AC. The density of oxygen-containing surface functional groups, measured by the Boehm titration, on WC was 5.4 times higher than that on AC, resulting in a pesticide adsorption by WC being 30-50% of that by AC, due to the blockage of WC surface by the waters associated with the functional groups. A small decrease (5.5%/unit pH) in diuron adsorption by WC with increase in pH resulted from increased deprotonation of surface functional groups at higher pH values. A much larger decrease (14-21%/unit pH) in bromoxynil adsorption by WC with increase in pH resulted from the deprotonation of both the adsorbate and surface functional groups of the adsorbent. The deprotonation reduced the adsorptive interaction between bromoxynil and the neutral carbon surface and increased the electrical repulsion between the negatively charged WC surface and bromoxynil anions. Deprotonation of ametryne with increase in pH over the low pH range increased its fraction of molecular form and thus adsorption on WC by 15%/unit pH. Further increase in pH resulted in a 20%/unit pH decrease in ametryne adsorption by WC due primarily to the development of a negative charge on the surface of WC. The pH-dependent adsorption of pesticides by black carbon may significantly influence their environmental fate in soils.

  5. Thermal and bonding properties of nano size carbon black filled PDMS

    CSIR Research Space (South Africa)

    Chen, H

    2009-12-01

    Full Text Available is varied from 10% to 25%. The mechanical property is characterized by testing the bond strength of the bond between pure PDMS and PDMS-CB composite. The bond between pure PDMS and 10% carbon black filled PDMS broke at 0.72 MPa. The bond has become very...

  6. Measured Black Carbon Deposition on the Sierra Nevada Snow Pack and Implication for Snow Pack Retreat

    Energy Technology Data Exchange (ETDEWEB)

    Hadley, O.L.; Corrigan, C.E.; Kirchstetter, T.W.; Cliff, S.S.; Ramanathan, V.

    2010-01-12

    Modeling studies show that the darkening of snow and ice by black carbon deposition is a major factor for the rapid disappearance of arctic sea ice, mountain glaciers and snow packs. This study provides one of the first direct measurements for the efficient removal of black carbon from the atmosphere by snow and its subsequent deposition to the snow packs of California. The early melting of the snow packs in the Sierras is one of the contributing factors to the severe water problems in California. BC concentrations in falling snow were measured at two mountain locations and in rain at a coastal site. All three stations reveal large BC concentrations in precipitation, ranging from 1.7 ng/g to 12.9 ng/g. The BC concentrations in the air after the snow fall were negligible suggesting an extremely efficient removal of BC by snow. The data suggest that below cloud scavenging, rather than ice nuclei, was the dominant source of BC in the snow. A five-year comparison of BC, dust, and total fine aerosol mass concentrations at multiple sites reveals that the measurements made at the sampling sites were representative of large scale deposition in the Sierra Nevada. The relative concentration of iron and calcium in the mountain aerosol indicates that one-quarter to one-third of the BC may have been transported from Asia.

  7. Upgrading pyrolytic residue from waste tires to commercial carbon black.

    Science.gov (United States)

    Zhang, Xue; Li, Hengxiang; Cao, Qing; Jin, Li'e; Wang, Fumeng

    2018-05-01

    The managing and recycling of waste tires has become a worldwide environmental challenge. Among the different disposal methods for waste tires, pyrolysis is regarded as a promising route. How to effectively enhance the added value of pyrolytic residue (PR) from waste tires is a matter of great concern. In this study, the PRs were treated with hydrochloric and hydrofluoric acids in turn under ultrasonic waves. The removal efficiency for the ash and sulfur was investigated. The pyrolytic carbon black (PCB) obtained after treating PR with acids was analyzed by X-ray fluorescence spectrophotometry, Fourier transform infrared spectrometry, X-ray diffractometry, laser Raman spectrometry, scanning electron microscopy, thermogravimetric (TG) analysis, and physisorption apparatus. The properties of PCB were compared with those of commercial carbon black (CCB) N326 and N339. Results showed PRs from waste tires were mainly composed of carbon, sulfur, and ash. The carbon in PCB was mainly from the CCB added during tire manufacture rather than from the pyrolysis of pure rubbers. The removal percentages for the ash and sulfur of PR are 98.33% (from 13.98 wt % down to 0.24 wt %) and 70.16% (from 1.81 wt % down to 0.54 wt %), respectively, in the entire process. The ash was mainly composed of metal oxides, sulfides, and silica. The surface properties, porosity, and morphology of the PCB were all close to those of N326. Therefore, PCB will be a potential alternative of N326 and reused in tire manufacture. This route successfully upgrades PR from waste tires to the high value-added CCB and greatly increases the overall efficiency of the waste tire pyrolysis industry.

  8. Analysis of the sources and dynamic processes leading to the increase of atmospheric CO2, black carbon and other trace species during recent urban pollution events in the Paris megacity region : a synergy of resources provided by the IPSL OCAPI platform.

    Science.gov (United States)

    Xueref-Remy, I.; Foret, G.; Beekmann, M.; Brégonzio-Rozier, L.; Favez, O.; Gros, V.; Moreau-Guigon, E.; Vogel, F. R.; Belviso, S.; Ghersi, V.; Dupont, J. C.; Bodichon, R.; Cailteau-Fischbach, C.; Baisnee, D.; Peinado, F.; Haeffelin, M.; DeCola, P.; Turnbull, J. C.; Chelin, P.; Te, Y. V.; Formenti, P.; Doussin, J. F.; Gratien, A.; Desboeufs, K. V.; Ramage, K.; Jeseck, P.; Delmotte, M.; Ramonet, M.; Michoud, V.; Ravetta, F.

    2016-12-01

    Nowadays, more than 50% of the global population leave in urban centers which activities generate large anthropogenic emissions of CO2 (more than 70% of fossil fuel CO2 comes from urbanized/industrialized areas) and reactive gases that endanger our climate, the health of human beings and surrounding ecosystems. The worst situations are encountered during urban pollution events that usually form under anticyclonic conditions. Analyzing the contribution of the local and regional sources of urban CO2 and co-emitted species vs the remote ones, as well as the nature of these sources and the dynamical processes that lead to the building of such events can provide interesting knowledge for helping urban policy makers to better identify the role of anthropogenic/biogenic sources on the urban air composition and to take proper decisions in matter of CO2 and pollutants sources mitigation. With 12 million of people, Paris (France) is the second megacity in Europe. In 2016, two pollution events occured in the Paris region during which the instrumental platform OCAPI (http://observations.ipsl.fr/composition-atmospherique-en-idf.html) from IPSL (Institut Pierre Simon Laplace) was mobilized in collaboration with air quality governing actors (AIRPARIF, INERIS) to collect a bunch of observations. Five sites located in the urban, peri-urban and rural areas of Paris were equiped with in-situ analyzers (CO2, CO, black carbon, 13CO2, COS) ; Fourier transform spectrometers for column measurements (XCO2, XCO, XCOS), particle filters (for aerosols size and content analysis) ; air samples (levoglucosan, 14CO2, VOCs) ; and Lidar profilers (boundary layer height ; wind profiles). These data, combined with a backtrajectories analysis, give information about the dynamical processes that lead to the formation of the pollution events and on the contribution of local, regional and remote sources. The analysis of the correlations between the trace species and of the isotopic content of carbon in

  9. Quantifying black carbon light absorption enhancement with a novel statistical approach

    Directory of Open Access Journals (Sweden)

    C. Wu

    2018-01-01

    Full Text Available Black carbon (BC particles in the atmosphere can absorb more light when coated by non-absorbing or weakly absorbing materials during atmospheric aging, due to the lensing effect. In this study, the light absorption enhancement factor, Eabs, was quantified using a 1-year measurement of mass absorption efficiency (MAE in the Pearl River Delta region (PRD. A new approach for calculating primary MAE (MAEp, the key for Eabs estimation, is demonstrated using the minimum R squared (MRS method, exploring the inherent source independency between BC and its coating materials. A unique feature of Eabs estimation with the MRS approach is its insensitivity to systematic biases in elemental carbon (EC and σabs measurements. The annual average Eabs550 is found to be 1.50 ± 0.48 (±1 SD in the PRD region, exhibiting a clear seasonal pattern with higher values in summer and lower in winter. Elevated Eabs in the summertime is likely associated with aged air masses, predominantly of marine origin, along with long-range transport of biomass-burning-influenced air masses from Southeast Asia. Core–shell Mie simulations along with measured Eabs and absorption Ångström exponent (AAE constraints suggest that in the PRD, the coating materials are unlikely to be dominated by brown carbon and the coating thickness is higher in the rainy season than in the dry season.

  10. Arctic black shale formation during Cretaceous Oceanic Anoxic Event 2

    DEFF Research Database (Denmark)

    Lenniger, Marc; Nøhr-Hansen, Henrik; Hills, Len V.

    2014-01-01

    The Late Cretaceous Oceanic Anoxic Event 2 (OAE2) represents a major perturbation of the global carbon cycle caused by the widespread deposition of organic-rich black shales. Although the paleoceanographic response and the spatial extent of bottom-water anoxia in low and mid-paleolatitudes are re......The Late Cretaceous Oceanic Anoxic Event 2 (OAE2) represents a major perturbation of the global carbon cycle caused by the widespread deposition of organic-rich black shales. Although the paleoceanographic response and the spatial extent of bottom-water anoxia in low and mid...... caused massive organic-carbon burial on the Arctic shelf in general, with important implications for hydrocarbon source-rock distribution in the Arctic region....

  11. Growth and hydrolase profiles can be used as characteristics to distinguish Aspergillus niger and other black aspergilli

    Science.gov (United States)

    Meijer, M.; Houbraken, J.A.M.P.; Dalhuijsen, S.; Samson, R.A.; de Vries, R.P.

    2011-01-01

    Wild type Aspergillus niger isolates from different biotopes from all over the world were compared to each other and to the type strains of other black Aspergillus species with respect to growth and extracellular enzyme profiles. The origin of the A. niger isolate did not result in differences in growth profile with respect to monomeric or polymeric carbon sources. Differences were observed in the growth rate of the A. niger isolates, but these were observed on all carbon sources and not specific for a particular carbon source. In contrast, carbon source specific differences were observed between the different species. Aspergillus brasiliensis is the only species able to grow on D-galactose, and A. aculeatus had significantly better growth on Locus Bean gum than the other species. Only small differences were found in the extracellular enzyme profile of the A. niger isolates during growth on wheat bran, while large differences were observed in the profiles of the different black aspergilli. In addition, differences were observed in temperature profiles between the black Aspergillus species, but not between the A. niger isolates, demonstrating no isolate-specific adaptations to the environment. These data indicate that the local environment does not result in stable adaptations of A. niger with respect to growth profile or enzyme production, but that the potential is maintained irrespective of the environmental parameters. It also demonstrates that growth, extracellular protein and temperature profiles can be used for species identification within the group of black aspergilli. PMID:21892240

  12. O2 electrocatalysis in acid media on iron naphthalocyanine impregnations. Effect of nitric acid treatment on different carbon black supports

    NARCIS (Netherlands)

    Coowar, F.; Contamin, O.; Savy, M.; Scarbeck, G.; van den Ham, D.; Riga, J.; Verbist, J.J.

    1991-01-01

    O2 electrocatalysis on (2,3)FeNPc impregnations on different carbon blacks was investigated in H2SO4 medium. The effect of nitric acid treatment on the carbon black support is to enhance both the activity and stability of the catalyst. Moreover, as seen by XPS, the dissolution of iron is impeded by

  13. Analyzing 20 years of Black Carbon measurements in Germany

    Science.gov (United States)

    Kutzner, R. D.; Quedenau, J.; Kuik, F.; von Schneidemesser, E.; Schmale, J.

    2016-12-01

    Black Carbon (BC) is an important short-lived climate-forcing pollutant contributing to global warming through absorption of sunlight. In addition, BC, as a component of particulate matter (PM) exerts adverse health effects. Anthropogenic emission sources of BC include residential heating, transport, and agricultural fires, and the dominant natural emission source is wildfires. Despite the adverse effects of BC, legislation that requires mandatory monitoring of BC concentrations does not currently exist in the European Union (EU). Instead, BC is only indirectly monitored as component of PM10 and PM2.5 (PM with a diameter smaller 10 µm and 2.5 µm, respectively). Before the introduction of mandatory PM10 and PM2.5 monitoring in the EU in 2005 and 2015, respectively, `black smoke' (BS), a surrogate for BC, was a required measurement in Germany from the early 1990s. The annual mean limit value was 14 µg/m3 from 1995 and 8 µg/m³ from 1998. In 2004, many measurements were stopped, with the repeal of the regulations. In most German federal states a limited number BC monitoring stations continued to operate. We present a synthesis of BC data from 213 stations across Germany covering the period between 1994 and 2014. Due to the lack of a standardized method and respective legislation, the data set is very heterogeneous relying on twelve different measurement methods including chemical, optical, and thermal-optical methods. Stations include, among others, urban background, traffic and rural. We highlight results from the year 2009, as it is the year with the largest measurement coverage based on the same measurement method, with 28 stations. Further, we calculated trends in BC concentrations for 13 stations with at least 10 years of data, for median concentrations, as well as 5th percentile (background) and 95th percentile (peak episodes). Preliminary results suggest that concentrations have generally declined, with a larger trend at traffic stations compared to urban

  14. A cellphone based system for large-scale monitoring of black carbon

    Science.gov (United States)

    Ramanathan, N.; Lukac, M.; Ahmed, T.; Kar, A.; Praveen, P. S.; Honles, T.; Leong, I.; Rehman, I. H.; Schauer, J. J.; Ramanathan, V.

    2011-08-01

    Black carbon aerosols are a major component of soot and are also a major contributor to global and regional climate change. Reliable and cost-effective systems to measure near-surface black carbon (BC) mass concentrations (hereafter denoted as [BC]) globally are necessary to validate air pollution and climate models and to evaluate the effectiveness of BC mitigation actions. Toward this goal we describe a new wireless, low-cost, ultra low-power, BC cellphone based monitoring system (BC_CBM). BC_CBM integrates a Miniaturized Aerosol filter Sampler (MAS) with a cellphone for filter image collection, transmission and image analysis for determining [BC] in real time. The BC aerosols in the air accumulate on the MAS quartz filter, resulting in a coloration of the filter. A photograph of the filter is captured by the cellphone camera and transmitted by the cellphone to the analytics component of BC_CBM. The analytics component compares the image with a calibrated reference scale (also included in the photograph) to estimate [BC]. We demonstrate with field data collected from vastly differing environments, ranging from southern California to rural regions in the Indo-Gangetic plains of Northern India, that the total BC deposited on the filter is directly and uniquely related to the reflectance of the filter in the red wavelength, irrespective of its source or how the particles were deposited. [BC] varied from 0.1 to 1 μg m -3 in Southern California and from 10 to 200 μg m -3 in rural India in our field studies. In spite of the 3 orders of magnitude variation in [BC], the BC_CBM system was able to determine the [BC] well within the experimental error of two independent reference instruments for both indoor air and outdoor ambient air. Accurate, global-scale measurements of [BC] in urban and remote rural locations, enabled by the wireless, low-cost, ultra low-power operation of BC_CBM, will make it possible to better capture the large spatial and temporal variations in

  15. Study of positron annihilation lifetime spectroscopy in carbon black-filled HDPE composite

    CERN Document Server

    Zhang Xian Feng; Zhou Xian Yi; Weng Hu Imin; Ye Bang Jiao; Han Rong Dian; Jia Shao Jin; Zhang Zhi Cheng

    2002-01-01

    The variation of the electrical conductivity of high density polyethylene (HDPE) with the carbon black (CB) content was studied using positron annihilation lifetime spectroscopy (PALS) and free-volume model, the crystallinity of HDPE/CB composite and 'percolation' effect were discussed with measurements of conductivity and DSC test

  16. Optical properties of sea ice doped with black carbon - an experimental and radiative-transfer modelling comparison

    Science.gov (United States)

    Marks, Amelia A.; Lamare, Maxim L.; King, Martin D.

    2017-12-01

    Radiative-transfer calculations of the light reflectivity and extinction coefficient in laboratory-generated sea ice doped with and without black carbon demonstrate that the radiative-transfer model TUV-snow can be used to predict the light reflectance and extinction coefficient as a function of wavelength. The sea ice is representative of first-year sea ice containing typical amounts of black carbon and other light-absorbing impurities. The experiments give confidence in the application of the model to predict albedo of other sea ice fabrics. Sea ices, ˜ 30 cm thick, were generated in the Royal Holloway Sea Ice Simulator ( ˜ 2000 L tanks) with scattering cross sections measured between 0.012 and 0.032 m2 kg-1 for four ices. Sea ices were generated with and without ˜ 5 cm upper layers containing particulate black carbon. Nadir reflectances between 0.60 and 0.78 were measured along with extinction coefficients of 0.1 to 0.03 cm-1 (e-folding depths of 10-30 cm) at a wavelength of 500 nm. Values were measured between light wavelengths of 350 and 650 nm. The sea ices generated in the Royal Holloway Sea Ice Simulator were found to be representative of natural sea ices. Particulate black carbon at mass ratios of ˜ 75, ˜ 150 and ˜ 300 ng g-1 in a 5 cm ice layer lowers the albedo to 97, 90 and 79 % of the reflectivity of an undoped clean sea ice (at a wavelength of 500 nm).

  17. Black carbon mixing state impacts on cloud microphysical properties: effects of aerosol plume and environmental conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ching, Ping Pui; Riemer, Nicole; West, Matthew

    2016-05-27

    Black carbon (BC) is usually mixed with other aerosol species within individual aerosol particles. This mixture, along with the particles' size and morphology, determines the particles' optical and cloud condensation nuclei properties, and hence black carbon's climate impacts. In this study the particle-resolved aerosol model PartMC-MOSAIC was used to quantify the importance of black carbon mixing state for predicting cloud microphysical quantities. Based on a set of about 100 cloud parcel simulations a process level analysis framework was developed to attribute the response in cloud microphysical properties to changes in the underlying aerosol population ("plume effect") and the cloud parcel cooling rate ("parcel effect"). It shows that the response of cloud droplet number concentration to changes in BC emissions depends on the BC mixing state. When the aerosol population contains mainly aged BC particles an increase in BC emission results in increasing cloud droplet number concentrations ("additive effect"). In contrast, when the aerosol population contains mainly fresh BC particles they act as sinks for condensable gaseous species, resulting in a decrease in cloud droplet number concentration as BC emissions are increased ("competition effect"). Additionally, we quantified the error in cloud microphysical quantities when neglecting the information on BC mixing state, which is often done in aerosol models. The errors ranged from -12% to +45% for the cloud droplet number fraction, from 0% to +1022% for the nucleation-scavenged black carbon (BC) mass fraction, from -12% to +4% for the effective radius, and from -30% to +60% for the relative dispersion.

  18. Catalytic Enhancement of Carbon Black and Coal-Fueled Hybrid Direct Carbon Fuel Cells

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Ippolito, Davide; Kammer Hansen, Kent

    2015-01-01

    , Ce1-xREExO2-δ (REE = Pr, Sm)) and metal oxides (LiMn2O4, Ag2O). Materials showing the highest activity in carbon black (Mn2O3, CeO2, Ce0.6Pr0.4O2-δ, Ag2O) were subsequently tested for catalytic activity toward bituminous coal, as revealed by both I-V-P curves and electrochemical impedance...... spectroscopy (EIS). Catalytic activity was evaluated as a function of various physical characteristics of doped ceria and manganese-based materials....

  19. Carbon black selection from simulated broth solution for ADU gel spheres

    International Nuclear Information System (INIS)

    Chai, Jeong Kyung; Ho, Eom Sung; Kim, Yeon Ku; Cho, Moon Seoung

    2012-01-01

    The VHTR (Very High Temperature Gas Reactor) is one of the reactor concepts in the Gen IV International Collaboration. The nuclear fuel of a VHTR in the US is based on microspheres containing a mixture of UO 2 and UC 2 coated with multi carbon layers and a SiC layer. This mixture is called a 'UCO (uranium oxi carbide)' kernel. The fabrication process of this kernel was based on the sol-gel method between an ADUN and HMTA and urea, a process referred to as internal gelation. UCO kernel microspheres were first prepared at ORNL in the late 1970s. CB(Carbon Black) as a carbon source in the final UCO kernel is added during the broth solution preparation, in the processing of UCO kernel fabrication. The preparation of a good quality UCO kernel is very difficult due to the homogeneous distribution of carbon in a UCO kernel. The key requirement to obtain a good quality kernel is a uniform distribution of carbon in the ADU gel sphere forming process before the thermal treatment, i.e., during the gel formation step. The internal gelation concept was adapted in ADU gel sphere fabrication in the ORNL process of the US. Generally, UO 2 kernel microspheres are prepared by an internal gelation method (USA, India) or external gelation method (Germany, China, Japan). The UCO kernel microspheres prepared only in the US, use an internal gelation method. A material flow chart on the preparation of the microsphere kernel is simply shown in Fig. 1. The broth solution preparation, the raw material, additives, and thermal steps such as calcining and sintering processes were different to compared with the external gelation and internal gelation methods. In this study, we first carried out the matching CB selection experiments among the various kinds of CBs in a broth solution, for UCO kernel preparation using an external gelation method.

  20. Effect of various carbon and nitrogen sources on cellulose synthesis ...

    African Journals Online (AJOL)

    The effect of various carbon and nitrogen sources on cellulose production by Acetobacter lovaniensis HBB5 was examined. In this study, glucose, fructose, sucrose and ethanol as carbon source and yeast extract, casein hydrolysate and ammonium sulphate as nitrogen source were used. Among the carbon sources, ...

  1. Relation between PAH and black carbon contents in size fractions of Norwegian harbor sediments

    International Nuclear Information System (INIS)

    Oen, Amy M.P.; Cornelissen, Gerard; Breedveld, Gijs D.

    2006-01-01

    Distributions of total organic carbon (TOC), black carbon (BC), and polycyclic aromatic hydrocarbons (PAH) were investigated in different particle size fractions for four Norwegian harbor sediments. The total PAH (16-EPA) concentrations ranged from 2 to 113 mg/kg dry weight with the greatest fraction of PAH mass in the sand fraction for three of the four sediments. TOC contents ranged from 0.84% to 14.2% and BC contents from 0.085% to 1.7%. This corresponds to organic carbon (OC = TOC - BC) contents in the range of 0.81-14% and BC:TOC ratios of 1.3-18.1%. PAH isomer ratios suggested that the PAH in all four sediments were of pyrogenic origin. Furthermore, stronger correlations between PAH versus BC (r 2 = 0.85) than versus OC (r 2 = 0.15) were found. For all size fractions and bulk sediments, the PAH-to-BC ratios for the total PAHs were on average 6 ± 3 mg PAH/g BC. These results suggest that PAH distributions were dominated by the presence of BC, rather than OC. As sorption to BC is much stronger than sorption to OC, this may result in significantly lower dissolved concentrations of PAH than expected on the basis of organic carbon partitioning alone. - PAH contents correlated better with black carbon than organic carbon for four Norwegian harbor sediments

  2. Hydrothermal, biogenic, and seawater components in metalliferous black shales of the Brooks Range, Alaska: Synsedimentary metal enrichment in a carbonate ramp setting

    Science.gov (United States)

    Slack, John F.; Selby, David; Dumoulin, Julie A.

    2015-01-01

    Trace element and Os isotope data for Lisburne Group metalliferous black shales of Middle Mississippian (early Chesterian) age in the Brooks Range of northern Alaska suggest that metals were sourced chiefly from local seawater (including biogenic detritus) but also from externally derived hydrothermal fluids. These black shales are interbedded with phosphorites and limestones in sequences 3 to 35 m thick; deposition occurred mainly on a carbonate ramp during intermittent upwelling under varying redox conditions, from suboxic to anoxic to sulfidic. Deposition of the black shales at ~335 Ma was broadly contemporaneous with sulfide mineralization in the Red Dog and Drenchwater Zn-Pb-Ag deposits, which formed in a distal marginal basin.Relative to the composition of average black shale, the metalliferous black shales (n = 29) display large average enrichment factors (>10) for Zn (10.1), Cd (11.0), and Ag (20.1). Small enrichments (>2–rare earth elements except Ce, Nd, and Sm. A detailed stratigraphic profile over 23 m in the Skimo Creek area (central Brooks Range) indicates that samples from at and near the top of the section, which accumulated during a period of major upwelling and is broadly correlative with the stratigraphic levels of the Red Dog and Drenchwater Zn-Pb-Ag deposits, have the highest Zn/TOC (total organic carbon), Cu/TOC, and Tl/TOC ratios for calculated marine fractions (no detrital component) of these three metals.Average authigenic (detrital-free) contents of Mo, V, U, Ni, Cu, Cd, Pb, Ge, Re, Se, As, Sb, Tl, Pd, and Au show enrichment factors of 4.3 × 103 to 1.2 × 106 relative to modern seawater. Such moderate enrichments, which are common in other metalliferous black shales, suggest wholly marine sources (seawater and biogenic material) for these metals, given similar trends for enrichment factors in organic-rich sediments of modern upwelling zones on the Namibian, Peruvian, and Chilean shelves. The largest enrichment factors for Zn and Ag

  3. Black Carbon And Co-Pollutants Emissions And Energy Efficiency From Bricks Production In Guanajuato, Mexico

    Science.gov (United States)

    Molina, L. T.; Zavala, M.; Maiz, P.; Monsivais, I.; Chow, J.; Munguia, J.

    2013-12-01

    In many parts of the world, small-scale traditional brick kilns are a notorious informal sector source of urban air pollution. Many are both inefficient and burn highly polluting fuels that emit significant levels of black carbon and other pollutants into local communities and to the atmosphere, resulting in severe health and environmental impacts. It is estimated that there are nearly 20,000 traditional brick kilns in Mexico, in which bricks are still produced as they have been for centuries. They are made by hand, dried in the sun, and generally fired in small, one chamber kilns that use various types of fuels, including plastic refuse, used tires, manure, wood scrap, and used motor oil. Three brick kilns, two traditional kilns and an improved kiln (MK2), were sampled as part of the SLCFs-Mexico campaign in Guanajuato, Mexico during March of 2013. The concept of the MK-2 involves covering the kiln with a dome and channeling the output of an active kiln through a second, identical loaded kiln for its additional filtration of the effluents. The results of energy efficiency and carbon mass balance calculations are presented for comparing the production efficiency and carbon emissions from the sampled kilns. Measurements included PM2.5 mass with quartz filters and temporally-resolved elemental carbon and organic carbon composition obtained using thermo-optical methods. The carbon emissions obtained with the mass balance method are compared with concurrent, high- time resolution, emissions measurements obtained using the Aerodyne mobile laboratory employing the tracer method (see abstract by Fortner et al.)

  4. 20 years of Black Carbon measurements in Germany

    Science.gov (United States)

    Kutzner, Rebecca; Quedenau, Jörn; Kuik, Friderike; von Schneidemesser, Erika; Schmale, Julia

    2016-04-01

    Black Carbon (BC) is an important short-lived climate-forcing pollutant contributing to global warming through absorption of sunlight. At the same time, BC, as a component of particulate matter (PM) exerts adverse health effects, like decreased lung function and exacerbated asthma. Globally, anthropogenic emission sources of BC include residential heating, transport, and agricultural fires, while the dominant natural emission sources are wildfires. Despite the various adverse effects of BC, legislation that requires mandatory monitoring of BC concentrations does not currently exist in the European Union. Instead, BC is only indirectly monitored as component of PM10 and PM2.5 (particulate matter with a diameter smaller 10 μm and 2.5 μm). Before the introduction of mandatory PM10 and PM2.5 monitoring in the European Union in 2005 and 2015, respectively, 'black smoke', a surrogate for BC, was a required measurement in Germany from the early 1990s. The annual mean limit value was 14 μg m-3 from 1995 and 8 μg m-3 from 1998 onwards. Many 'black smoke' measurements were stopped in 2004, with the repeal of the regulations obtaining at the time. However, in most German federal states a limited number BC monitoring stations continued to operate. Here we present a synthesis of BC data from 213 stations across Germany covering the period between 1994 and 2014. Due to the lack of a standardized method and respective legislation, the data set is very heterogeneous relying on twelve different measurement methods including chemical, optical, and thermal-optical methods. Stations include locations classified as background, urban-background, industrial and traffic among other types. Raw data in many different formats has been modelled and integrated in a relational database, allowing various options for further data analysis. We highlight results from the year 2009, as it is the year with the largest measurement coverage based on the same measurement method, with 30 stations. In

  5. Photo-lability of deep ocean dissolved black carbon

    Directory of Open Access Journals (Sweden)

    A. Stubbins

    2012-05-01

    Full Text Available Dissolved black carbon (DBC, defined here as condensed aromatics isolated from seawater via PPL solid phase extraction and quantified as benzenepolycarboxylic acid (BPCA oxidation products, is a significant component of the oceanic dissolved organic carbon (DOC pool. These condensed aromatics are widely distributed in the open ocean and appear to be tens of thousands of years old. As such DBC is regarded as highly refractory. In the current study, the photo-lability of DBC, DOC and coloured dissolved organic matter (CDOM; ultraviolet-visible absorbance were determined over the course of a 28 day irradiation of North Atlantic Deep Water under a solar simulator. During the irradiation DBC fell from 1044 ± 164 nM-C to 55 ± 15 nM-C, a 20-fold decrease in concentration. Dissolved black carbon photo-degradation was more rapid and more extensive than for bulk CDOM and DOC. The concentration of DBC correlated with CDOM absorbance and the quality of DBC indicated by the ratios of different BPCAs correlated with CDOM absorbance spectral slope, suggesting the optical properties of CDOM may provide a proxy for both DBC concentrations and quality in natural waters. Further, the photo-lability of components of the DBC pool increased with their degree of aromatic condensation. These trends indicate that a continuum of compounds of varying photo-lability exists within the marine DOC pool. In this continuum, photo-lability scales with aromatic character, specifically the degree of condensation. Scaling the rapid photo-degradation of DBC to rates of DOC photo-mineralisation for the global ocean leads to an estimated photo-chemical half-life for oceanic DBC of less than 800 years. This is more than an order of magnitude shorter than the apparent age of DBC in the ocean. Consequently, photo-degradation is posited as the primary sink for oceanic DBC and the apparent survival of DBC molecules in the oceans for millennia appears to be facilitated not by their

  6. Black carbon measurements during winter 2013-2014 in Athens and intercomparison between different techniques

    Science.gov (United States)

    Liakakou, Eleni; Stravroulas, Jason; Roukounakis, Nikolaos; Paraskevopoulou, Despina; Fourtziou, Luciana; Psiloglou, Vassilis; Gerasopoulos, Evangelos; Sciare, Jean; Mihalopoulos, Nikolaos

    2014-05-01

    Black carbon (BC) is a particulate pollutant species emitted from the combustion of fuels, biomass burning for agricultural purposes and forest fires, with the first two anthropogenic sources being the major contributors to the atmospheric burden of BC. The presence of BC is important due to its direct and indirect physicochemical effects and its use as a tracer of burning and subsequent transport processes. Black carbon measurements took place during winter 2013 -2014 in the frame of a pollution monitoring experiment conducted at the urban site of Thissio, Athens (city center) at the premises of the National Observatory of Athens. The economic crisis in Greece and the resulting turn of Athens inhabitants to wood burning for domestic heating, has led to increased daily concentrations of BC in the range of 2-6 μg m-3, peaking at night time (15-20 μg m-3). Three different optical methods were used for the determination of BC. A Particle Soot Absorption Photometer (PSAP; Radiance Research) commercial instrument was used to monitor the light absorption coefficient (σap) at 565 nm of ambient aerosols, with 1 minute resolution. During parts of the campaign, a portable Aethalometer (AE-42; Magee Scientific) was also used to provide measurement of the aerosol BC content at 7 wavelengths over 5 minutes intervals. Exploiting the measurements at different wavelengths is was feasible to separate wood burning BC from BC related to fossil fuel. Two Multi Angle Absorption Photometers (MAAP; Thermo) were also operated as reference. Finally, aerosol samples were collected on 12-hour basis using a sequential dichotomous sampler for the sampling of PM2.5, PM2.5-10and PM10 fractions of aerosols on quartz filters, and the filters were analyzed for elemental carbon (EC) by a thermal - optical transmission technique. The main objective of the study is the intercomparison of the different BC monitoring techniques under a large range of ambient concentrations achieved due to the special

  7. Short-Range-Order Mineral Physical Protection On Black Carbon Stabilization

    Science.gov (United States)

    Liang, B.; Weng, Y. T.; Wang, C. C.; Song, Y. F.; Lehmann, J.; Wang, C. H.

    2015-12-01

    Soil organic matter is one of the largest reservoirs in global carbon cycle, and black carbon (BC) represents a chemical resistant component. Black C plays an important role in global climate change. Generally considered recalcitrant due to high aromaticity, the reactive surface and functional groups of BC are crucial for carbon sequestration in soils. Mineral sorption and physical protection is an important mechanism for BC long term stabilization and sequestration in environments. Previous studies on mineral protection of BC were limited to analysis techniques in two-dimensions, for example, by SEM, TEM, and NanoSIMS. Little is known about the scope of organo-mineral association, the in-situ distribution and forms of minerals, and the ultimate interplay of BC and minerals. The aim of this study is to investigate the three-dimensional interaction of organic C and minerals in submicron scale using synchrotron-based Transmission X-ray Microcopy (TXM) and Fourier-Transform Infrared Spectroscopy (FTIR). Abundant poorly-crystallined nano-minerals particles were observed. These short-range-order (SRO) minerals also aggregate into clusters and sheets, and form envelops-like structures on the surface of BC. On top of large surface contact area, the intimate interplay between BC and minerals reinforces the stability of both organic C and minerals, resulting from chemical bonding through cation bridging and ligand exchange. The mineral protection enhances BC stabilization and sequestration and lowers its bioavailability in environment. The results suggest that mineral physical protection for BC sequestration may be more important than previous understanding.

  8. Distribution of black carbon in Ponderosa pine litter and soils following the High Park wildfire

    Science.gov (United States)

    Boot, C. M.; Haddix, M.; Paustian, K.; Cotrufo, M. F.

    2014-12-01

    Black carbon (BC), the heterogeneous product of burned biomass, is a critical component in the global carbon cycle, yet timescales and mechanisms for incorporation into the soil profile are not well understood. The High Park Fire, which took place in northwestern Colorado in the summer of 2012, provided an opportunity to study the effects of both fire intenstiy and geomorphology on properties of carbon (C), nitrogen (N), and BC in the Cache La Poudre River drainage. We sampled montane Ponderosa pine litter, 0-5 cm soils, and 5-15 cm soils four months post-fire in order to examine the effects of slope and burn intensity on %C, C stocks, %N and black carbon (g kg-1 C, and g m-2). We developed and implemented the benzene polycarboxylic acid (BPCA) method for quantifying BC. With regard to slope, we found that steeper slopes had higher C : N than shallow slopes, but that there was no difference in black carbon content or stocks. BC content was greatest in the litter in burned sites (19 g kg-1 C), while BC stocks were greatest in the 5-15 cm subsurface soils (23 g m-2). At the time of sampling, none of the BC deposited on the land surface post-fire had been incorporated into to either the 0-5 cm or 5-15 cm soil layers. The ratio of B5CA : B6CA (less condensed to more condensed BC) indicated there was significantly more older, more processed BC at depth. Total BC soil stocks were relatively low compared to other fire-prone grassland and boreal forest systems, indicating most of the BC produced in this system is likely transported off the surface through erosion events. Future work examining mechanisms for BC transport will be required for understanding the role BC plays in the global carbon cycle.

  9. Bardeen regular black hole with an electric source

    Science.gov (United States)

    Rodrigues, Manuel E.; Silva, Marcos V. de S.

    2018-06-01

    If some energy conditions on the stress-energy tensor are violated, is possible construct regular black holes in General Relativity and in alternative theories of gravity. This type of solution has horizons but does not present singularities. The first regular black hole was presented by Bardeen and can be obtained from Einstein equations in the presence of an electromagnetic field. E. Ayon-Beato and A. Garcia reinterpreted the Bardeen metric as a magnetic solution of General Relativity coupled to a nonlinear electrodynamics. In this work, we show that the Bardeen model may also be interpreted as a solution of Einstein equations in the presence of an electric source, whose electric field does not behave as a Coulomb field. We analyzed the asymptotic forms of the Lagrangian for the electric case and also analyzed the energy conditions.

  10. Effect of carbon black composition with sludge palm oil on the curing characteristic and mechanical properties of natural rubber/styrene butadiene rubber compound

    Science.gov (United States)

    Mohamed, R.; Nurazzi, N. Mohd; Huzaifah, M.

    2017-07-01

    This study was conducted to investigate the possibility of utilizing sludge palm oil (SPO) as processing oil, with various amount of carbon black as its reinforcing filler, and its effects on the curing characteristics and mechanical properties of natural rubber/styrene butadiene rubber (NR/SBR) compound. Rubber compound with fixed 15 pphr of SPO loading, and different carbon black loading from 20 to 50 pphr, was prepared using two roll mills. The cure characteristics and mechanical tests that have been conducted are the scorch and cure time analysis, tensile strength and tear strength. Scorch time (ts5) and cure time (t90) of the compound increases with the increasing carbon black loading. The mechanical properties of NR/SBR compound viz. the tensile strength, modulus at 300% strain and tear strength were also improved by the increasing carbon black loading.

  11. Carbon black nanoparticles induce type II epithelial cells to release chemotaxins for alveolar macrophages

    Directory of Open Access Journals (Sweden)

    Donaldson Ken

    2005-12-01

    Full Text Available Abstract Background Alveolar macrophages are a key cell in dealing with particles deposited in the lungs and in determining the subsequent response to that particle exposure. Nanoparticles are considered a potential threat to the lungs and the mechanism of pulmonary response to nanoparticles is currently under intense scrutiny. The type II alveolar epithelial cell has previously been shown to release chemoattractants which can recruit alveolar macrophages to sites of particle deposition. The aim of this study was to assess the responses of a type II epithelial cell line (L-2 to both fine and nanoparticle exposure in terms of secretion of chemotactic substances capable of inducing macrophage migration. Results Exposure of type II cells to carbon black nanoparticles resulted in significant release of macrophage chemoattractant compared to the negative control and to other dusts tested (fine carbon black and TiO2 and nanoparticle TiO2 as measured by macrophage migration towards type II cell conditioned medium. SDS-PAGE analysis of the conditioned medium from particle treated type II cells revealed that a higher number of protein bands were present in the conditioned medium obtained from type II cells treated with nanoparticle carbon black compared to other dusts tested. Size-fractionation of the chemotaxin-rich supernatant determined that the chemoattractants released from the epithelial cells were between 5 and 30 kDa in size. Conclusion The highly toxic nature and reactive surface chemistry of the carbon black nanoparticles has very likely induced the type II cell line to release pro-inflammatory mediators that can potentially induce migration of macrophages. This could aid in the rapid recruitment of inflammatory cells to sites of particle deposition and the subsequent removal of the particles by phagocytic cells such as macrophages and neutrophils. Future studies in this area could focus on the exact identity of the substance(s released by the

  12. Distribution, Transport, and Accumulation of Pyrogenic Black Carbon in Post-Wildfire Watersheds

    Science.gov (United States)

    Galanter, A.; Cadol, D. D.; Frey, B.; Lohse, K. A.

    2014-12-01

    Large, high severity wildfires greatly alter forest structure, water quality, and soil development/erosion. With increased frequency of such wildfires also follows heavy post-wildfire debris flows and flooding which deliver high loads of sediment and pyrogenic black carbon (PyC) to downstream waterways. The accumulation of PyC is a multi-faceted and dynamic issue in the critical zone. Generated by incomplete combustion of organic matter, PyC (in the form of soot and char) impacts turbidity, biological and chemical oxygen demand, and pH. In addition, PyC has the potential to sequester contaminants and can store carbon over short and long timescales. The impacts of two recent wildfires in Northern New Mexico are studied with the goal of understanding the fluxes and residence times of PyC in post-wildfire, mountainous watersheds. Employing burn severity maps and geospatial data, we selected three sites to collect soil and water samples to characterize PyC: a control, an area impacted by a large, severe burn (2011), and an area impacted by a smaller, less severe burn (2013). By collaborating with researchers at the Jemez Critical Zone Observatory, soil samples are being analyzed and will provide pre-wildfire PyC concentrations for the 2013 burn area. In this study, PyC is treated as both a particulate and a solute that is transported throughout the watershed as well as degraded in soils, surface water and groundwater. We used two black carbon quantification methods: the chemo-thermal oxidation (CTO-375) method to distinguish between soil soot and char, and the benzene polycarboxylic acids (BPCA) method to quantify the total concentrations of PyC in soil and water samples. Preliminary soil data from the CTO-375 method show comparable soot concentrations in the control, 2011, and 2013 burn indicating that the soot is more recalcitrant than char and remains in the watershed long after a wildfire. This data also suggests that the fluxes of black carbon over short time

  13. Black carbon and other light-absorbing impurities in the Andes of Northern Chile

    Science.gov (United States)

    Rowe, P. M.; Cordero, R.; Warren, S. G.; Pankow, A.; Jorquera, J.; Schrempf, M.; Doherty, S. J.; Cabellero, M.; Carrasco, J. F.; Neshyba, S.

    2015-12-01

    Black carbon (BC) and other light-absorbing impurities in snow absorb solar radiation and thus have the potential to accelerate glacial retreat and snowmelt. In Chile, glaciers and seasonal snow are important sources of water for irrigation and domestic uses. In July 2015 (Austral winter) we sampled snow in the western Andes in a north-south transect of Chile from 18 S to 34 S. Most of the sampled snow had fallen during a single synoptic event, during 11-13 July. The snow was melted and passed through 0.4 micrometer nuclepore filters. Preliminary estimates indicate that (1) the ratio of BC to dust in snow increases going south from Northern to Central Chile, and (2) in snow sampled during the two weeks following the snowstorm, the impurities were concentrated in the upper 5 cm of snow, indicating that the surface layer became polluted over time by dry deposition.

  14. Do Regional Aerosols Contribute to the Riverine Export of Dissolved Black Carbon?

    Science.gov (United States)

    Jones, M. W.; Quine, T. A.; de Rezende, C. E.; Dittmar, T.; Johnson, B.; Manecki, M.; Marques, J. S. J.; de Aragão, L. E. O. C.

    2017-11-01

    The fate of black carbon (BC), a stable form of thermally altered organic carbon produced during biomass and fuel combustion, remains an area of uncertainty in the global carbon cycle. The transfer of photosynthetically derived BC into extremely long-term oceanic storage is of particular significance and rivers are the key linkage between terrestrial sources and oceanic stores. Significant fluvial fluxes of dissolved BC to oceans result from the slow release of BC from degrading charcoal stocks; however, these fluvial fluxes may also include undetermined contributions of aerosol BC, produced by biomass and fossil fuel combustion, which are deposited in river catchments following atmospheric transport. By investigation of the Paraíba do Sul River catchment in Southeast Brazil we show that aerosol deposits can be substantial contributors to fluvial fluxes of BC. We derived spatial distributions of BC stocks within the catchment associated with soil charcoal and with aerosol from both open biomass burning and fuel combustion. We then modeled the fluvial concentrations of dissolved BC (DBC) in scenarios with varying rates of export from each stock. We analyzed the ability of each scenario to reproduce the variability in DBC concentrations measured in four data sets of river water samples collected between 2010 and 2014 and found that the best performing scenarios included a 5-18% (135-486 Mg DBC year-1) aerosol contribution. Our results suggest that aerosol deposits of BC in river catchments have a shorter residence time in catchments than charcoal BC and, therefore, contribute disproportionately (with respect to stock magnitude) toward fluvial fluxes of BC.

  15. Spinning, structure and properties of PP/CNTs and PP/carbon black composite fibers

    Science.gov (United States)

    Marcincin, A.; Hricova, M.; Ujhelyiova, A.

    2014-08-01

    In this paper, the effect of the compatibilisers-dispersants and other nanofillers on melt spinning of the polypropylene (PP) composites, containing carbon nanotubes (CNTs), and carbon black pigment (CBP) has been investigated. Further, the structure and selected properties of composite fibers, such as mechanical and electrical have been studied. The results revealed, that percolation threshold for PP/CBP composite fibres was situated within the concentration of 15 - 20 wt%, what is several times higher than for PP/CNTs fibers.

  16. ANALYSIS OF DEVONIAN BLACK SHALES IN KENTUCKY FOR POTENTIAL CARBON DIOXIDE SEQUESTRATION AND ENHANCED NATURAL GAS PRODUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Brandon C. Nuttall

    2003-02-10

    Proposed carbon management technologies include geologic sequestration of CO{sub 2}. A possible, but untested, strategy is to inject CO{sub 2} into organic-rich shales of Devonian age. Devonian black shales underlie approximately two-thirds of Kentucky and are generally thicker and deeper in the Illinois and Appalachian Basin portions of Kentucky. The Devonian black shales serve as both the source and trap for large quantities of natural gas; total gas in place for the shales in Kentucky is estimated to be between 63 and 112 trillion cubic feet. Most of this natural gas is adsorbed on clay and kerogen surfaces, analogous to the way methane is stored in coal beds. In coals, it has been demonstrated that CO{sub 2} is preferentially adsorbed, displacing methane at a ratio of two to one. Black shales may similarly desorb methane in the presence of CO{sub 2}. If black shales similarly desorb methane in the presence of CO{sub 2}, the shales may be an excellent sink for CO{sub 2} with the added benefit of serving to enhance natural gas production. The concept that black, organic-rich Devonian shales could serve as a significant geologic sink for CO{sub 2} is the subject this research. To accomplish this investigation, drill cuttings and cores will be selected from the Kentucky Geological Survey Well Sample and Core Library. CO{sub 2} adsorption analyses will be performed in order to determine the gas-storage potential of the shale and to identify shale facies with the most sequestration potential. In addition, new drill cuttings and sidewall core samples will be acquired to investigate specific black-shale facies, their uptake of CO{sub 2}, and the resultant displacement of methane. Advanced logging techniques (elemental capture spectroscopy) will be used to investigate possible correlations between adsorption capacity and geophysical log measurements.

  17. ANALYSIS OF DEVONIAN BLACK SHALES IN KENTUCKY FOR POTENTIAL CARBON DIOXIDE SEQUESTRATION AND ENHANCED NATURAL GAS PRODUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Brandon C. Nuttall

    2003-04-28

    Proposed carbon management technologies include geologic sequestration of CO{sub 2}. A possible, but untested, strategy is to inject CO{sub 2} into organic-rich shales of Devonian age. Devonian black shales underlie approximately two-thirds of Kentucky and are generally thicker and deeper in the Illinois and Appalachian Basin portions of Kentucky. The Devonian black shales serve as both the source and trap for large quantities of natural gas; total gas in place for the shales in Kentucky is estimated to be between 63 and 112 trillion cubic feet. Most of this natural gas is adsorbed on clay and kerogen surfaces, analogous to the way methane is stored in coal beds. In coals, it has been demonstrated that CO{sub 2} is preferentially adsorbed, displacing methane at a ratio of two to one. Black shales may similarly desorb methane in the presence of CO{sub 2}. If black shales similarly desorb methane in the presence of CO{sub 2}, the shales may be an excellent sink for CO{sub 2} with the added benefit of serving to enhance natural gas production. The concept that black, organic-rich Devonian shales could serve as a significant geologic sink for CO{sub 2} is the subject this research. To accomplish this investigation, drill cuttings and cores will be selected from the Kentucky Geological Survey Well Sample and Core Library. CO{sub 2} adsorption analyses will be performed in order to determine the gas-storage potential of the shale and to identify shale facies with the most sequestration potential. In addition, new drill cuttings and sidewall core samples will be acquired to investigate specific black-shale facies, their uptake of CO{sub 2}, and the resultant displacement of methane. Advanced logging techniques (elemental capture spectroscopy) will be used to investigate possible correlations between adsorption capacity and geophysical log measurements.

  18. ANALYSIS OF DEVONIAN BLACK SHALES IN KENTUCKY FOR POTENTIAL CARBON DIOXIDE SEQUESTRATION AND ENHANCED NATURAL GAS PRODUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Brandon C. Nuttall

    2003-02-11

    Proposed carbon management technologies include geologic sequestration of CO{sub 2}. A possible, but untested, strategy is to inject CO{sub 2} into organic-rich shales of Devonian age. Devonian black shales underlie approximately two-thirds of Kentucky and are generally thicker and deeper in the Illinois and Appalachian Basin portions of Kentucky. The Devonian black shales serve as both the source and trap for large quantities of natural gas; total gas in place for the shales in Kentucky is estimated to be between 63 and 112 trillion cubic feet. Most of this natural gas is adsorbed on clay and kerogen surfaces, analogous to the way methane is stored in coal beds. In coals, it has been demonstrated that CO{sub 2} is preferentially adsorbed, displacing methane at a ratio of two to one. Black shales may similarly desorb methane in the presence of CO{sub 2}. If black shales similarly desorb methane in the presence of CO{sub 2}, the shales may be an excellent sink for CO{sub 2} with the added benefit of serving to enhance natural gas production. The concept that black, organic-rich Devonian shales could serve as a significant geologic sink for CO{sub 2} is the subject this research. To accomplish this investigation, drill cuttings and cores will be selected from the Kentucky Geological Survey Well Sample and Core Library. CO{sub 2} adsorption analyses will be performed in order to determine the gas-storage potential of the shale and to identify shale facies with the most sequestration potential. In addition, new drill cuttings and sidewall core samples will be acquired to investigate specific black-shale facies, their uptake of CO{sub 2}, and the resultant displacement of methane. Advanced logging techniques (elemental capture spectroscopy) will be used to investigate possible correlations between adsorption capacity and geophysical log measurements.

  19. Optical Properties of Small Ice Crystals with Black Carbon Inclusions

    Science.gov (United States)

    Yang, X.; Geier, M.; Arienti, M.

    2013-12-01

    The optical properties of ice crystals play a fundamental role in modeling atmospheric radiation and hydrological cycle, which are critical in monitoring climate change. While Black Carbon (BC) is recognized as the dominant absorber with positive radiative forcing (warming) (Ramanathan & Carmichael, 2008), in-situ observations (Cappa, et al, 2012) indicate that the characterization of the mixing state of BC with ice crystals and other non-BC particles in global climate models (Ghan & Schwartz, 2007) needs further investigation. The limitation in the available mixing models is due to the drastically different absorbing properties of BC compared to other aerosols. We explore the scattering properties of ice crystals (in shapes commonly found in cirrus clouds and contrails - Yang, et al. 2012) with the inclusion of BC particles. The Discrete Dipole Approximation (DDA) (Yurkin & Hoekstra, 2011) is utilized to directly calculate the optical properties of the crystals with multiple BC inclusions, modeled as a distribution of spheres. The results are then compared with the most popular models of internal and external mixing (Liou, et al. 2011). The DDA calculations are carried out over a broad range of BC particle sizes and volume fractions within the crystal at the 532 nm wavelength and for ice crystals smaller than 50 μm. The computationally intensive database generated in this study is critical for understanding the effect of different types of BC inclusions on the atmosphere radiative forcing. Examples will be discussed to illustrate the modification of BC optical properties by encapsulation in ice crystals and how the parameterization of the BC mixing state in global climate models can be improved. Acknowledgements Support by Sandia National Laboratories' LDRD (Laboratory Directed Research and Development) is gratefully acknowledged. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of

  20. The Contribution of Black Carbon to Ice Nucleating Particle Concentrations from Prescribed Burns and Wildfires

    Science.gov (United States)

    Schill, G. P.; DeMott, P. J.; Suski, K. J.; Emerson, E. W.; Rauker, A. M.; Kodros, J.; Levin, E. J.; Hill, T. C. J.; Farmer, D.; Pierce, J. R.; Kreidenweis, S. M.

    2017-12-01

    Black carbon (BC) has been implicated as a potential immersion-mode ice nucleating particle (INP) because of its relative abundance in the upper troposphere. Furthermore, several field and aircraft measurements have observed positive correlations between BC and INP concentrations. Despite this, the efficiency of BC to act as an immersion-mode INP is poorly constrained. Indeed, previous results from laboratory studies are in conflict, with estimates of BC's impact on INP ranging from no impact to being efficient enough to rival the well-known INP mineral dust. It is, however, becoming clear that the ice nucleation activity of BC may depend on both its fuel type and combustion conditions. For example, previous work has shown that diesel exhaust BC is an extremely poor immersion-mode INP, but laboratory burns of biomass fuels indicate that BC can contribute up to 70% of all INP for some fuel types. Given these dependencies, we propose that sampling from real-world biomass burning sources would provide the most useful new information on the contribution of BC to atmospheric INP. In this work, we will present recent results looking at the sources of INP from prescribed burns and wildfires. To determine the specific contribution of refractory black carbon (rBC) to INP concentrations, we utilized a new technique that couples the Single Particle Soot Photometer (SP2) to the Colorado State University Continuous Flow Diffusion Chamber (CFDC). The SP2 utilizes laser-induced incandescence to quantify rBC mass on a particle-by-particle basis; in doing so, it also selectively destroys rBC particles by heating them to their vaporization temperature. Thus, the SP2 can be used as a selective pre-filter for rBC into the CFDC. Furthermore, we have also used a filter-based technique for measuring INP, the Ice Spectrometer, which can employ pretreatments such as heating and digestion by H2O2 to determine the contribution of heat-labile and organic particles, respectively.

  1. Temporal characteristics of black carbon concentrations and its potential emission sources in a southern Taiwan industrial urban area.

    Science.gov (United States)

    Cheng, Yu-Hsiang; Lin, Chi-Chi; Liu, Jyh-Jian; Hsieh, Cheng-Ju

    2014-03-01

    This study investigates the temporal characteristics of black carbon and its potential emission sources, as well as the fractions of BC in PM2.5 levels in Kaohsiung urban area, which is an industrial city in southern Taiwan. Concentrations of BC and PM2.5 are monitored continuously from March 2006 to February 2010, using an aethalometer and a tapered element oscillating microbalance monitor. Additionally, the presence of organic compounds (or UV enhanced species) in particles at the sampling site is determined using the Delta-C (UVBC-BC) value. According to long-term measurement results, BC and PM2.5 concentrations are 3.33 and 34.0 μg m(-3), respectively, in the Kaohsiung urban area. The ratio of BC/PM2.5 is approximately 11 %. Low concentration of BC and PM2.5 in the summer of this study period is mostly likely owing to meteorological conditions that favored dispersion of local air pollutants. Nevertheless, BC concentrations peaked markedly during morning hours (7:00-11:00), likely owing to local traffic congestion. Measurement results suggest that BC is released from local traffic activities and emitted from industrial activities at this sampling site. Additionally, Delta-C values are significantly higher than zero during January-March and November-December periods in this industrial urban area, implying that UV enhanced species can be observed. At this sampling site, these UV enhanced species do not only originate from household activity and solid waste burning but also release from industrial activities. The elevated Delta-C values during nighttime (18:00-6:00) in the autumn and winter seasons are likely related to those UV enhanced species in the atmosphere, which can be condensed on particle surface under low temperature conditions. According to long-term measurement results, significantly positive Delta-C values can be observed under temperatures industrial parks and a coal-fired power plant.

  2. Quantification methods of Black Carbon: Comparison of Rock-Eval analysis with traditional methods

    NARCIS (Netherlands)

    Poot, A.; Quik, J.T.K.; Veld, H.; Koelmans, A.A.

    2009-01-01

    Black Carbon (BC) quantification methods are reviewed, including new Rock-Eval 6 data on BC reference materials. BC has been reported to have major impacts on climate, human health and environmental quality. Especially for risk assessment of persistent organic pollutants (POPs) it is important to

  3. Quantitative Analysis of Major Factors Affecting Black Carbon Transport and Concentrations in the Unique Atmospheric Structures of Urban Environment

    Science.gov (United States)

    Liang, Marissa Shuang

    Black carbon (BC) from vehicular emission in transportation is a principal component of particulate matters ≤ 2.5 mum (PM2.5). PM2.5 and other diesel emission pollutants (e.g., NOx) are regulated by the Clean Air Act (CAA) according to the National Ambient Air Quality standards (NAAQS). This doctoral dissertation details a study on transport behaviors of black carbon and PM2.5 from transportation routes, their relations with the atmospheric structure of an urban formation, and their relations with the use of biodiesel fuels. The results have implications to near-road risk assessment and to the development of sustainable transportation solutions in urban centers. The first part of study quantified near-roadside black carbon transport as a function of particulate matter (PM) size and composition, as well as microclimatic variables (temperature and wind fields) at the interstate highway I-75 in northern Cincinnati, Ohio. Among variables examined, wind speed and direction significantly affect the roadside transport of black carbon and hence its effective emission factor. Observed non-Gaussian dispersion occurred during low wind and for wind directions at acute angles or upwind to the receptors, mostly occurring in the morning hours. Meandering of air pollutant mass under thermal inversion is likely the driving force. In contrary, Gaussian distribution predominated in daytime of strong downwinds. The roles of urban atmospheric structure, wind fields, and the urban heat island (UHI) effects were further examined on pollutant dispersion and transport. Spatiotemporal variations of traffic flow, atmospheric structure, ambient temperature and PM2.5 concentration data from 14 EPA-certified NAAQS monitoring stations, were analyzed in relation to land-use in the Cincinnati metropolitan area. The results show a decade-long UHI effects with higher interior temperature than that in exurban, and a prominent nocturnal thermal inversion frequent in urban boundary layer. The

  4. Thermal conductivity and stability of nano size carbon black filled PDMS: Fuel cell perspective

    CSIR Research Space (South Africa)

    Chen, H

    2011-01-01

    Full Text Available Carbon black filled Polydimethylsiloxane (PDMS) was considered as a prospective bipolar plate material candidate for a Fuel Cell. In this perspective, thermal conductivity and stability of the composites were investigated. Samples with filler weight...

  5. Solar Photothermal Disinfection using Broadband-Light Absorbing Gold Nanoparticles and Carbon Black.

    Science.gov (United States)

    Loeb, Stephanie; Li, Chuanhao; Kim, Jae-Hong

    2018-01-02

    A simple heat treatment, perhaps the most globally recognized point-of-use water sterilization method, is seemingly effective against all major pathogens of concern, but bulk water boiling is not energy efficient or sustainable. Herein, we present the first application of solar-to-thermal converting nanomaterials for the direct inactivation of bacteria and viruses in drinking water through the application of Au nanorods, carbon black, and Au nanorod-carbon black composite materials as light absorbers. With broad absorption bands spanning the visible and near-infrared wavelengths, at sufficient concentrations, these nanoparticles induce multiple scattering events, increasing photon absorption probability and concentrating the light within a small spatial domain, leading to localized, intense heating that inactivates microorganisms in close proximity. Moving toward practical device design, we have developed a facile silane immobilization approach to fabricate films with densely packed layers of photothermal nanomaterials. Our results suggest that upon irraditaion with simulated solar light, these films can thermally inactivate bacteria and viruses, as demonstrated through the inactivation of surrogate organisms Escherichia coli K-12, and bacteriophages MS2 and PR772.

  6. Century-scale high-resolution black carbon records in sediment cores from the South Yellow Sea, China

    Science.gov (United States)

    Xu, Xiaoming; Hong, Yuehui; Zhou, Qianzhi; Liu, Jinzhong; Yuan, Lirong; Wang, Jianghai

    2018-01-01

    Black carbon (BC) has received increasing attention in the last 20 years because it is not only an absorbent of toxic pollutants but also a greenhouse substance, preserving fire-history records, and more importantly, acting as an indicator of biogeochemical cycles and global changes. By adopting an improved chemothermal oxidation method (WXY), this study reconstructed the century-scale high-resolution records of BC deposition from two fine-grained sediment cores collected from the Yellow Sea Cold Water Mass in the South Yellow Sea. The BC records were divided into five stages, which exhibited specific sequences with three BC peaks at approximately 1891, 1921, and 2007 AD, representing times at which the first heavy storms appeared just after the termination of long-term droughts. The significant correlation between the times of the BC peaks in the cores and heavy storms in the area of the Huanghe (Yellow) River demonstrated that BC peaks could result from markedly strengthened sedimentation due to surface runoff, which augmented the atmospheric deposition. Stable carbon isotope analysis indicated that the evident increase in carbon isotope ratios of BC in Stage 5 might have resulted from the input of weathered rock-derived graphitic carbon cardinally induced by the annual anthropogenic modulation of water-borne sediment in the Huanghe River since 2005 AD. Numerical calculations demonstrated that the input fraction of graphitic carbon was 22.97% for Stage 5, whereas no graphitic carbon entered during Stages 1 and 3. The obtained data provide new and important understanding of the source-sink history of BC in the Yellow Sea.

  7. Influence of plasma treatment of carbon blacks on electrochemical activity of Pt/carbon blacks catalysts for DMFCs

    Science.gov (United States)

    Kim, Seok; Cho, Mi-Hwa; Lee, Jae-Rock; Park, Soo-Jin

    In this work, in order to improve the dispersion of platinum catalysts deposited on carbon materials, the effects of surface plasma treatment of carbon blacks (CBs) were investigated. The surface characteristics of the CBs were determined by fourier transformed-infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), and Boehm's titration method. The electrochemical properties of the plasma-treated CBs-supported Pt (Pt/CBs) catalysts were analyzed by linear sweep voltammetry (LSV) experiments. From the results of FT-IR and acid-base values, N 2-plasma treatment of the CBs at 300 W intensity led to a formation of a free radical on the CBs. The peak intensity increased with increase of the treatment time, due to the formation of new basic functional groups (such as C-N, C dbnd N, -NH 3 +, -NH, and dbnd NH) by the free radical on the CBs. Accordingly, the basic values were enhanced by the basic functional groups. However, after a specific reaction time, N 2-plasma treatment could hardly influence on change of the surface functional groups of CBs, due to the disappearance of free radical. Consequently, it was found that optimal treatment time was 30 s for the best electro activity of Pt/CBs catalysts and the N 2-plasma treated Pt/CBs possessed the better electrochemical properties than the pristine Pt/CBs.

  8. Few-Layer Black Phosphorus Carbide Field-Effect Transistor via Carbon Doping.

    Science.gov (United States)

    Tan, Wee Chong; Cai, Yongqing; Ng, Rui Jie; Huang, Li; Feng, Xuewei; Zhang, Gang; Zhang, Yong-Wei; Nijhuis, Christian A; Liu, Xinke; Ang, Kah-Wee

    2017-06-01

    Black phosphorus carbide (b-PC) is a new family of layered semiconducting material that has recently been predicted to have the lightest electrons and holes among all known 2D semiconductors, yielding a p-type mobility (≈10 5 cm 2 V -1 s -1 ) at room temperature that is approximately five times larger than the maximum value in black phosphorus. Here, a high-performance composite few-layer b-PC field-effect transistor fabricated via a novel carbon doping technique which achieved a high hole mobility of 1995 cm 2 V -1 s -1 at room temperature is reported. The absorption spectrum of this material covers an electromagnetic spectrum in the infrared regime not served by black phosphorus and is useful for range finding applications as the earth atmosphere has good transparency in this spectral range. Additionally, a low contact resistance of 289 Ω µm is achieved using a nickel phosphide alloy contact with an edge contacted interface via sputtering and thermal treatment. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Primary genotoxicity in the liver following pulmonary exposure to carbon black nanoparticles in mice

    DEFF Research Database (Denmark)

    Modrzynska, Justyna; Berthing, Trine; Ravn-Haren, Gitte

    2018-01-01

    Background Little is known about the mechanism underlying the genotoxicity observed in the liver following pulmonary exposure to carbon black (CB) nanoparticles (NPs). The genotoxicity could be caused by the presence of translocated particles or by circulating inflammatory mediators released during...

  10. Influence of large changes in public transportation (Transantiago) on the black carbon pollution near streets

    Science.gov (United States)

    Gramsch, E.; Le Nir, G.; Araya, M.; Rubio, M. A.; Moreno, F.; Oyola, P.

    2013-02-01

    In 2006 a large transformation was carried out on the public transportation system in Santiago de Chile. The original system (before 2006) had hundreds of bus owners with about 7000 diesel buses. The new system has only 13 firms with about 5900 buses which operate in different parts of the city with little overlap between them. In this work we evaluate the impact of the Transantiago system on the black carbon pollution along four roads directly affected by the modification to the transport system. Measurements were carried out during May-July of 2005 (before Transantiago) and June-July of 2007 (after Transantiago). We have used the Wilcoxon rank-sum test to evaluate black carbon concentration in four streets in year 2005 and 2007. The results show that a statistically significant reduction between year 2005 (before Transantiago) and year 2007 (after Transantiago) in Alameda street, which changed from a mean of 18.8 μg m-3 in 2005 to 11.9 μg m-3 in 2007. In this street there was a decrease in the number of buses as well as the number of private vehicles and an improvement in the technology of public transportation between those years. Other two streets (Usach and Departamental) did not change or experienced a small increase in the black carbon concentration in spite of having less flux of buses in 2007. Eliodoro Yañez Street, which did not have public transportation in 2005 or 2007 experienced a 15% increase in the black carbon concentration between those years. Analysis of the data indicates that the change is related to a decrease in the total number of vehicles or the number of other diesel vehicles in the street rather than a decrease in the number of buses only. These results are an indication that in order to decrease pollution near a street is not enough to reduce the number of buses or improve its quality, but to reduce the total number of vehicles.

  11. Black carbon inclusive multichemical modeling of PBDE and PCB biomagnification and -transformation in estuarine food webs.

    Science.gov (United States)

    Di Paolo, Carolina; Gandhi, Nilima; Bhavsar, Satyendra P; Van den Heuvel-Greve, Martine; Koelmans, Albert A

    2010-10-01

    Bioavailability and bioaccumulation of polybrominated diphenylethers (PBDEs) are affected by adsorption on black carbon (BC) and metabolism in biota, respectively. Recent studies have addressed these two processes separately, illustrating their importance in assessing contaminant dynamics. In order to properly examine biomagnification of polychlorinated biphenyls (PCBs) and PBDEs in an estuarine food-web, here we set up a black carbon inclusive multichemical model. A dual domain sorption model, which accounted for sorption to organic matter (OM) and black carbon (BC), was used to estimate aqueous phase concentrations from the measured chemical concentrations in suspended solids. We adapted a previously published multichemical model that tracks the movement of a parent compound and its metabolites in each organism and within its food web. First, the model was calibrated for seven PCB congeners assuming negligible metabolism. Subsequently, PBDE biomagnification was modeled, including biotransformation and bioformation of PBDE congeners, keeping the other model parameters the same. The integrated model was capable of predicting trophic magnification factors (TMF) within error limits. PBDE metabolic half-lives ranged 21-415 days and agreed to literature data. The results showed importance of including BC as an adsorbing phase, and biotransformation and bioformation of PBDEs for a proper assessment of their dynamics in aquatic systems.

  12. Determination of black carbon and nanoparticles along glaciers in the Spitsbergen (Svalbard) region exploiting a mobile platform

    Science.gov (United States)

    Spolaor, Andrea; Barbaro, Elena; Mazzola, Mauro; Viola, Angelo P.; Lisok, Justyna; Obleitner, Friedrich; Markowicz, Krzysztof M.; Cappelletti, David

    2017-12-01

    An innovative approach to characterize concentration of atmospheric aerosol particles and air mass layering along the elevation profile of glaciers is presented for the first time and validated, exploiting low weight and fast response sensors deployed on a snowmobile. Two micro-Aethalometers for black carbon measurements and a miniature Diffusion Size Classifier (miniDisc) for total aerosol concentration (airborne particles) in the 14-260 nm range were used. Test experiments were conducted in the Arctic (Svalbard) in Spring (2016). Three glaciers in the Spitsbergen region were considered for this exploratory study, the Austre Brøggerbreen, the Edithbreen and the Kongsvegen. The Austre Brøggerbreen and Edithbreen were considered as test sites to setup the experiment, to optimize the sampling strategy and to identify some basic experimental artefacts. Kongsvegen glacier was chosen for the main case study, extending from the Kongsfjorden coast to roughly 700 m above sea level for a total length of ca. 25 km and with a nearly constant elevation gradient. The obtained results were rather consistent for the three glaciers and show an increase of nanoparticles with altitude. Black carbon concentration show stationary to decreasing trends going from the bottom to the top of the glaciers. These observations indicate a very active secondary aerosol formation at the highest elevations, responsible for the increase concentration of ultrafine particles at the glacier top. On the other side, black carbon shows higher levels at the lower altitudes of the glacier. This is indicative that in absence of a long-range transport as demonstrated by calculated back trajectories, black carbon might have accumulated due to the effect of katabatic winds flow along the glacier profile. The results obtained were compared and are largely consistent with the observations from concurrent soundings with a tethered balloon experiment conducted in the nearby site of Ny-Ålesund. The proposed

  13. Exploration of biodegradation mechanisms of black carbon-bound nonylphenol in black carbon-amended sediment

    International Nuclear Information System (INIS)

    Cheng, Guanghuan; Sun, Mingyang; Ge, Xinlei; Xu, Xinhua; Lin, Qi; Lou, Liping

    2017-01-01

    The present study aimed to investigate biodegradation mechanisms of black carbon (BC)-bound contaminants in BC-amended sediment when BC was applied to control organic pollution. The single-point Tenax desorption technique was applied to track the species changes of nonylphenol (NP) during biodegradation process in the rice straw carbon (RC)-amended sediment. And the correlation between the biodegradation and desorption of NP was analyzed. Results showed that microorganisms firstly degraded the rapid-desorbing NP (6 h Tenax desorption) in RC-amended sediment. The biodegradation facilitated the desorption of slow-desorbing NP, which was subsequently degraded as well (192 h Tenax desorption). Notably, the final amount of NP degradation was greater than that of NP desorption, indicating that absorbed NP by RC amendment can be degraded by microorganisms. Finally, the residual NP amount in RC-amended sediment was decided by RC content and its physicochemical property. Moreover, the presence of the biofilm was observed by the confocal laser scanning microscope (CLSM) and scanning electron microscope (SEM) so that microorganisms were able to overcome the mass transfer resistance and directly utilized the absorbed NP. Therefore, single-point Tenax desorption alone may not be an adequate basis for the prediction of the bioaccessibility of contaminants to microorganisms or bioremediation potential in BC-amended sediment. - Highlights: • Biodegradation mechanism of RC-bound NP in sediment was examined. • The microbe prioritized the degradation of NP in desorption fraction. • The microbe formed the biofilm to directly degrade part of non-desorbable NP. • Residual NP amount was decided by RC content and physicochemical property. • Quantifying biodegradation by bioavailability will underestimate the actual outcomes. - The microbes directly degrade the non-desorbable NP bound to amended RC, so quantifying the biodegradation only by desorption will underestimate the

  14. Black Carbon and Kerosene Lighting: An Opportunity for Rapid Action on Climate Change and Clean Energy for Development

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, Arne [Humboldt State Univ., MN (United States). Schatz Energy Research Center; Bond, Tami C. [Univ. of Illinois at Urbana-Champaign, IL (United States). Dept. of Civil and Environmental Engineering; Lam, Nicholoas L. [Univ. of California, Berkeley, CA (United States). Dept. of Environmental Health Sciences; Hultman, Nathan [The Brookings Institution, Washington, DC (United States)

    2013-04-15

    Replacing inefficient kerosene lighting with electric lighting or other clean alternatives can rapidly achieve development and energy access goals, save money and reduce climate warming. Many of the 250 million households that lack reliable access to electricity rely on inefficient and dangerous simple wick lamps and other kerosene-fueled light sources, using 4 to 25 billion liters of kerosene annually to meet basic lighting needs. Kerosene costs can be a significant household expense and subsidies are expensive. New information on kerosene lamp emissions reveals that their climate impacts are substantial. Eliminating current annual black carbon emissions would provide a climate benefit equivalent to 5 gigatons of carbon dioxide reductions over the next 20 years. Robust and low-cost technologies for supplanting simple wick and other kerosene-fueled lamps exist and are easily distributed and scalable. Improving household lighting offers a low-cost opportunity to improve development, cool the climate and reduce costs.

  15. A mass of less than 15 solar masses for the black hole in an ultraluminous X-ray source.

    Science.gov (United States)

    Motch, C; Pakull, M W; Soria, R; Grisé, F; Pietrzyński, G

    2014-10-09

    Most ultraluminous X-ray sources have a typical set of properties not seen in Galactic stellar-mass black holes. They have luminosities of more than 3 × 10(39) ergs per second, unusually soft X-ray components (with a typical temperature of less than about 0.3 kiloelectronvolts) and a characteristic downturn in their spectra above about 5 kiloelectronvolts. Such puzzling properties have been interpreted either as evidence of intermediate-mass black holes or as emission from stellar-mass black holes accreting above their Eddington limit, analogous to some Galactic black holes at peak luminosity. Recently, a very soft X-ray spectrum was observed in a rare and transient stellar-mass black hole. Here we report that the X-ray source P13 in the galaxy NGC 7793 is in a binary system with a period of about 64 days and exhibits all three canonical properties of ultraluminous sources. By modelling the strong optical and ultraviolet modulations arising from X-ray heating of the B9Ia donor star, we constrain the black hole mass to be less than 15 solar masses. Our results demonstrate that in P13, soft thermal emission and spectral curvature are indeed signatures of supercritical accretion. By analogy, ultraluminous X-ray sources with similar X-ray spectra and luminosities of up to a few times 10(40) ergs per second can be explained by supercritical accretion onto massive stellar-mass black holes.

  16. Growth of graphene films from non-gaseous carbon sources

    Science.gov (United States)

    Tour, James; Sun, Zhengzong; Yan, Zheng; Ruan, Gedeng; Peng, Zhiwei

    2015-08-04

    In various embodiments, the present disclosure provides methods of forming graphene films by: (1) depositing a non-gaseous carbon source onto a catalyst surface; (2) exposing the non-gaseous carbon source to at least one gas with a flow rate; and (3) initiating the conversion of the non-gaseous carbon source to the graphene film, where the thickness of the graphene film is controllable by the gas flow rate. Additional embodiments of the present disclosure pertain to graphene films made in accordance with the methods of the present disclosure.

  17. Dielectric study of Poly(styrene- co -butadiene) Composites with Carbon Black, Silica, and Nanoclay

    KAUST Repository

    Vo, Loan T.

    2011-08-09

    Dielectric spectroscopy is used to measure polymer relaxation in styrene-butadiene rubber (SBR) composites. In addition to the bulk polymer relaxation, the SBR nanocomposites also exhibit a slower relaxation attributed to polymer relaxation at the polymer-nanoparticle interface. The glass transition temperature associated with the slower relaxation is used as a way to quantify the interaction strength between the polymer and the surface. Comparisons were made among composites containing nanoclay, silica, and carbon black. The interfacial relaxation glass transition temperature of SBR-clay nanocomposites is more than 80 °C higher than the SBR bulk glass transition temperature. An interfacial mode was also observed for SBR-silica nanocomposites, but the interfacial glass transition temperature of SBR-silica nanocomposite is somewhat lower than that of clay nanocomposites. An interfacial mode is also seen in the carbon black filled system, but the signal is too weak to analyze quantitatively. The interfacial polymer relaxation in SBR-clay nanocomposites is stronger compared to both SBR-carbon black and SBR-silica composites indicating a stronger interfacial interaction in the nanocomposites containing clay. These results are consistent with dynamic shear rheology and dynamic mechanical analysis measurements showing a more pronounced reinforcement for the clay nanocomposites. Comparisons were also made among clay nanocomposites using different SBRs of varying styrene concentration and architecture. The interfacial glass transition temperature of SBR-clay nanocomposites increases as the amount of styrene in SBR increases indicating that styrene interacts more strongly than butadiene with clay. © 2011 American Chemical Society.

  18. Testing the ``Wildfire Hypothesis:'' Terrestrial Organic Carbon Burning as the Cause of the Paleocene-Eocene Boundary Carbon Isotope Excursion

    Science.gov (United States)

    Moore, E. A.; Kurtz, A. C.

    2005-12-01

    The 3‰ negative carbon isotope excursion (CIE) at the Paleocene-Eocene boundary has generally been attributed to dissociation of seafloor methane hydrates. We are testing the alternative hypothesis that the carbon cycle perturbation resulted from wildfires affecting the extensive peatlands and coal swamps formed in the Paleocene. Accounting for the CIE with terrestrial organic carbon rather than methane requires a significantly larger net release of fossil carbon to the ocean-atmosphere, which may be more consistent with the extreme global warming and ocean acidification characteristic of the Paleocene-Eocene Thermal Maximum (PETM). While other researchers have noted evidence of fires at the Paleocene-Eocene boundary in individual locations, the research presented here is designed to test the "wildfire hypothesis" for the Paleocene-Eocene boundary by examining marine sediments for evidence of a global increase in wildfire activity. Such fires would produce massive amounts of soot, widely distributed by wind and well preserved in marine sediments as refractory black carbon. We expect that global wildfires occurring at the Paleocene-Eocene boundary would produce a peak in black carbon abundance at the PETM horizon. We are using the method of Gelinas et al. (2001) to produce high-resolution concentration profiles of black carbon across the Paleocene-Eocene boundary using seafloor sediments from ODP cores, beginning with the Bass River core from ODP leg 174AX and site 1209 from ODP leg 198. This method involves the chemical and thermal extraction of non-refractory carbon followed by combustion of the residual black carbon and measurement as CO2. Measurement of the δ 13C of the black carbon will put additional constraints on the source of the organic material combusted, and will allow us to determine if this organic material was formed prior to or during the CIE.

  19. Small-angle scattering, contrast variation and the study of complex composite materials: A study of the structure of carbon black

    International Nuclear Information System (INIS)

    Hjelm, R.P. Jr.; Seeger, P.A.; Wampler, W.A.

    1993-01-01

    Detailed studies are presented on the structure and aggregation of an experimental high surface area carbon black (HSA) using small-angle neutron scattering and the method of contrast variation. We find that the approximately 27 mn HSA particle form small, linear aggregates of average aggregation number 5 when suspended in cyclohexane. There is considerable density fluctuation in the interior of these particles, with the denser regions being toward the outer part of the spherically-averaged structure. This information would not have been obtained from studies of carbon black without solvent. The results will be applied to similar scattering studies on solvent-swollen bound rubber gels made from HSA-polyisoprene. These result show, however, that the strong internal fluctuations of the carbon black will limit the information that can be obtained on the structure and conformation of the elastomer in the gel. There are additional limitation from compositional heterogeneity of the sample

  20. Comparison of Spheroidal Carbonaceous Particle Data with Modelled Atmospheric Black Carbon Concentration and Deposition and Air Mass Sources in Northern Europe, 1850–2010

    Directory of Open Access Journals (Sweden)

    Meri Ruppel

    2013-01-01

    Full Text Available Spheroidal carbonaceous particles (SCP are a well-defined fraction of black carbon (BC, produced only by the incomplete combustion of fossil fuels such as coal and oil. Their past concentrations have been studied using environmental archives, but, additionally, historical trends of BC concentration and deposition can be estimated by modelling. These models are based on BC emission inventories, but actual measurements of BC concentration and deposition play an essential role in their evaluation and validation. We use the chemistry transport model OsloCTM2 to model historical time series of BC concentration and deposition from energy and industrial sources and compare these to sedimentary measurements of SCPs obtained from lake sediments in Northern Europe from 1850 to 2010. To determine the origin of SCPs we generated back trajectories of air masses to the study sites. Generally, trends of SCP deposition and modelled results agree reasonably well, showing rapidly increasing values from 1950, to a peak in 1980, and a decrease towards the present. Empirical SCP data show differences in deposition magnitude between the sites that are not captured by the model but which may be explained by different air mass transport patterns. The results highlight the need for numerous observational records to reliably validate model results.

  1. Robust Means for Estimating Black Carbon-Water Sorption Coefficients of Organic Contaminants in Sediments

    Science.gov (United States)

    2015-07-01

    compounds by black carbon, Springer, Dordrecht. Plata, D.L., Hemingway , J.D. and Gschwend, P.M. (2015) Polyparameter linear free energy relationship for...1320-1331. 32 8. Appendices Scientific/Technical Publications Plata, D.L., J.D. Hemingway , and P.M. Gschwend. Polyparameter linear free energy

  2. Study of carbon black obtained by pyrolysis of waste scrap tyres

    Czech Academy of Sciences Publication Activity Database

    Mikulová, Z.; Šeděnková, Ivana; Matějová, Lenka; Večeř, M.; Dombek, V.

    2013-01-01

    Roč. 111, č. 2 (2013), s. 1475-1481 ISSN 1388-6150. [Central and Eastern European Conference on Thermal Analysis and Calorimetry /1./ - CEEC-TAC1. Craiova, 07.09.2011-10.09.2011] R&D Projects: GA ČR GA104/09/0972 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z40720504 Keywords : scrap tyres * carbon black * thermogravimetry Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.206, year: 2013

  3. Towards Soil and Sediment Inventories of Black Carbon

    Science.gov (United States)

    Masiello, C. A.

    2008-12-01

    A body of literature on black carbon (BC) concentrations in soils and sediments is rapidly accumulating, but as of yet, there are no global or regional inventories of BC in either reservoir. Soil and sediment BC inventories are badly needed for a range of fields. For example, in oceanography a global sediment BC inventory is crucial in understanding the role of biomass burning in the development of stable marine carbon reservoirs, including dissolved organic carbon and sedimentary organic carbon. Again in the marine environment, BC likely strongly impacts the fate and transport of anthropogenic pollutants: regional inventories of BC in sediments will help develop better environmental remediation strategies. In terrestrial systems well-constrained natural BC soil inventories would help refine ecological, agricultural, and soil biogeochemical studies. BC is highly sorptive of nutrients including nitrogen and phosphorous. The presence of BC in ecosystems almost certainly alters N and P cycling; however, without soil BC inventories, we cannot know where BC has a significant impact. BC's nutrient sorptivity and water-holding capacity make it an important component of agricultural soils, and some researchers have proposed artificially increasing soil BC inventories to improve soil fertility. Natural soil BC concentrations in some regions are quite high, but without a baseline inventory, it is challenging to predict when agricultural amendment will significantly exceed natural conditions. And finally, because BC is one of the most stable fractions of organic carbon in soils, understanding its concentration and regional distribution will help us track the dynamics of soil organic matter response to changing environmental conditions. Developing effective regional and global BC inventories is challenging both because of data sparsity and methodological intercomparison issues. In this presentation I will describe a roadmap to generating these valuable inventories.

  4. ON THE ROLE OF FAST MAGNETIC RECONNECTION IN ACCRETING BLACK HOLE SOURCES

    International Nuclear Information System (INIS)

    Singh, C. B.; De Gouveia Dal Pino, E. M.; Kadowaki, L. H. S.

    2015-01-01

    We attempt to explain the observed radio and gamma-ray emission produced in the surroundings of black holes by employing a magnetically dominated accretion flow model and fast magnetic reconnection triggered by turbulence. In earlier work, a standard disk model was used and we refine the model by focusing on the sub-Eddington regime to address the fundamental plane of black hole activity. The results do not change substantially with regard to previous work, ensuring that the details of accretion physics are not relevant in the magnetic reconnection process occurring in the corona. Rather, our work puts fast magnetic reconnection events as a powerful mechanism operating in the core region near the jet base of black hole sources on more solid ground. For microquasars and low-luminosity active galactic nuclei, the observed correlation between radio emission and the mass of the sources can be explained by this process. The corresponding gamma-ray emission also seems to be produced in the same core region. On the other hand, emission from blazars and gamma-ray bursts cannot be correlated to core emission based on fast reconnection

  5. Carbon source feeding strategies for recombinant protein ...

    African Journals Online (AJOL)

    USER

    2010-04-12

    Apr 12, 2010 ... protein expression with the influence of the carbon source feeding ... in the culture media, increasing the peroxisomes numbers ...... source, temperature, pH, O2, methanol feeding strategy) ..... Catabolite Inactivation in Yeast.

  6. Anti-oxidative and inflammatory responses induced by fly ash particles and carbon black in lung epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Diabate, Silvia; Plaumann, Diana; Uebel, Caroline; Weiss, Carsten [Karlsruhe Institute of Technology, Institute of Toxicology and Genetics, Eggenstein-Leopoldshafen (Germany); Bergfeldt, Britta [Karlsruhe Institute of Technology, Institute of Technical Chemistry, Eggenstein-Leopoldshafen (Germany)

    2011-12-15

    Combustion-derived nanoparticles as constituents of ambient particulate matter have been shown to induce adverse health effects due to inhalation. However, the components inducing these effects as well as the biological mechanisms are still not fully understood. The fine fraction of fly ash particles collected from the electrostatic precipitator of a municipal solid waste incinerator was taken as an example for real particles with complex composition released into the atmosphere to study the mechanism of early biological responses of BEAS-2B human lung epithelial cells. The studies include the effects of the water-soluble and -insoluble fractions of the fly ash and the well-studied carbon black nanoparticles were used as a reference. Fly ash induced reactive oxygen species (ROS) and increased the total cellular glutathione (tGSH) content. Carbon black also induced ROS generation; however, in contrast to the fly ash, it decreased the intracellular tGSH. The fly ash-induced oxidative stress was correlated with induction of the anti-oxidant enzyme heme oxygenase-1 and increase of the redox-sensitive transcription factor Nrf2. Carbon black was not able to induce HO-1. ROS generation, tGSH increase and HO-1 induction were only induced by the insoluble fraction of the fly ash, not by the water-soluble fraction. ROS generation and HO-1 induction were markedly inhibited by pre-incubation of the cells with the anti-oxidant N-acetyl cysteine which confirmed the involvement of oxidative stress. Both effects were also reduced by the metal chelator deferoxamine indicating a contribution of bioavailable transition metals. In summary, both fly ash and carbon black induce ROS but only fly ash induced an increase of intracellular tGSH and HO-1 production. Bioavailable transition metals in the solid water-insoluble matrix of the fly ash mostly contribute to the effects. (orig.)

  7. Optical properties of sea ice doped with black carbon – an experimental and radiative-transfer modelling comparison

    Directory of Open Access Journals (Sweden)

    A. A. Marks

    2017-12-01

    Full Text Available Radiative-transfer calculations of the light reflectivity and extinction coefficient in laboratory-generated sea ice doped with and without black carbon demonstrate that the radiative-transfer model TUV-snow can be used to predict the light reflectance and extinction coefficient as a function of wavelength. The sea ice is representative of first-year sea ice containing typical amounts of black carbon and other light-absorbing impurities. The experiments give confidence in the application of the model to predict albedo of other sea ice fabrics. Sea ices,  ∼  30 cm thick, were generated in the Royal Holloway Sea Ice Simulator ( ∼  2000 L tanks with scattering cross sections measured between 0.012 and 0.032 m2 kg−1 for four ices. Sea ices were generated with and without  ∼  5 cm upper layers containing particulate black carbon. Nadir reflectances between 0.60 and 0.78 were measured along with extinction coefficients of 0.1 to 0.03 cm−1 (e-folding depths of 10–30 cm at a wavelength of 500 nm. Values were measured between light wavelengths of 350 and 650 nm. The sea ices generated in the Royal Holloway Sea Ice Simulator were found to be representative of natural sea ices. Particulate black carbon at mass ratios of  ∼  75,  ∼  150 and  ∼  300 ng g−1 in a 5 cm ice layer lowers the albedo to 97, 90 and 79 % of the reflectivity of an undoped clean sea ice (at a wavelength of 500 nm.

  8. Carbon trading and carbon taxation: how to consider biotic sources and sinks

    International Nuclear Information System (INIS)

    Madlener, Reinhard; Schlamadinger, Bernhard

    1999-01-01

    The Kyoto Protocol (KP) to the UNFCCC includes land-use change and forestry in the carbon accounting process, limited to afforestation, reforestation and deforestation since 1990, and explicitly provides for the option of using a variety of flexibility mechanisms to meet the greenhouse gas (GHG) reduction targets stipulated in a more cost-efficient manner. Domestically, different countries might adopt different approaches to achieve their emission reduction objectives, such as carbon trading or carbon taxation, and it is not clear to date what the implications for bioenergy use, forestry, and land-use change can be expected to be. With respect to national GHG emissions trading, the main issues studied in this paper are: Should trading of fossil fuel emissions allowances be coupled with trading of biotic credits and debits? Should credits for carbon sequestration in forests be auctioned or grandfathered? Should there be a distinction between a carbon permit issued for an additional biotic sink and those issued for fossil fuel carbon emissions? Is there a difference for biotic carbon sinks and sources between one-time permits and permits that allow a continued release of GHG over some pre-specified time? Should permits be issued only for the carbon-stock changes that count under the KP? With respect to national carbon taxation schemes, two questions are investigated: Should a tax credit be given for afforestation/reforestation (and a tax debit for deforestation)? Should tax credits also be given for projects that sequester carbon but do not count under the KP (such as forest protection rather than forest management)? For both schemes a crucial point is that by the formulation chosen in the KP two different classes of forest are created (i.e. those counted and those not counted under the KP), so that the implications for land prices might be significant. From a conceptual point of view this paper addresses the above-mentioned questions and contrasts some of the major

  9. Carbon source in the future chemical industries

    Science.gov (United States)

    Hofmann, Peter; Heinrich Krauch, Carl

    1982-11-01

    Rising crude oil prices favour the exploitation of hitherto unutilised energy carriers and the realisation of new technologies in all sectors where carbon is used. These changed economic constraints necessitate both savings in conventional petrochemistry and a change to oil-independent carbon sources in the chemical industry. While, in coal chemistry, the synthesis and process principles of petrochemistry — fragmentation of the raw material and subsequent buildup of molecular structures — can be maintained, the raw material structure largely remains unchanged in the chemistry of renewable raw materials. This lecture is to demonstrate the structural as well as the technological and energy criteria of the chemistry of alternative carbon sources, to forecast the chances of commercial realization and to discuss some promising fields of research and development.

  10. Hairy carbon electrodes studied by cyclic voltammetry and battery discharge testing

    Science.gov (United States)

    Chung, Deborah D. L.; Shui, Xiaoping; Frysz, Christine A.

    1993-01-01

    Hairy carbon is a new material developed by growing submicron carbon filaments on conventional carbon substrates. Typical substrate materials include carbon black, graphite powder, carbon fibers, and glassy carbon. A catalyst is used to initiate hair growth with carbonaceous gases serving as the carbon source. To study the electrochemical behavior of hairy carbons, cyclic voltammetry (CV) and discharge testing were conducted. In both cases, hairy carbon results surpassed those of the substrate material alone.

  11. Variable effects of plant colonization on black slate uptake into microbial PLFAs

    Science.gov (United States)

    Seifert, Anne-Gret; Trumbore, Susan; Xu, Xiaomei; Zhang, Dachung; Gleixner, Gerd

    2013-04-01

    Microbial degradation of carbon derived from black shale and slate has been shown in vitro. However, in natural settings where other labile carbon sources are likely to exist, this has not been previously demonstrated. We investigated the uptake of ancient carbon derived from slate weathering and from recently photosynthesised organic matter by different groups of microorganisms. Therefore we isolated microbial biomarkers (phospholipid fatty acids, PLFAs) from black slates collected at a chronosequence of waste piles which differed in age and vegetation cover. We quantified the amount of PLFAs and performed stable isotope and radiocarbon measurements on individual or grouped PLFAs to quantify the fraction of slate derived carbon. We used black slate from a pile heaped in the 1950s with either uncovered black slate material (bare site) or material slightly colonized by small plants (greened site) and from a forested leaching pile (forested site) used for alum-mining in the 19th century. Colonization by plants influenced the amount and composition of the microbial community. Greater amounts of PLFAs (5410 ng PLFA/g dw) were extracted from slate sampled at the forested site as opposed to the bare site (960 ng PLFAs/g dw) or the greened (annual grasses and mosses) rock waste pile (1050 ng PLFAs/g dw). We found the highest proportion of PLFAs representing Gram-negative bacteria on the forested site and the highest proportion of PLFAs representing Gram-positive bacteria on the bare site. The fungal PLFA was most abundant at the greened site. Sites with less plant colonization (bare and greened site) tended to have more depleted δ13C values compared to the forested site. Radiocarbon measurements on PLFAs indicated that fungi and Gram-positive bacteria were best adapted to black slate carbon uptake. In the fungal PLFA (combined bare and greened waste pile sample) and in PLFAs of Gram-positive bacteria (greened site) we measured 39.7% and 28.9% ancient carbon uptake

  12. Projection of SO2, NOx, NMVOC, particulate matter and black carbon emissions - 2015-2030

    DEFF Research Database (Denmark)

    Nielsen, Ole-Kenneth; Plejdrup, Marlene Schmidt; Hjelgaard, Katja Hossy

    This report contains a description of models and background data for projection of SO2, NOX, NMVOC, PM2.5 and black carbon for Denmark. The emissions are projected to 2030 using basic scenarios together with the expected results of a few individual policy measures. Official Danish forecasts...

  13. Analysis of the Interphase on Carbon Black Formed in High Voltage Batteries

    DEFF Research Database (Denmark)

    Younesi, Reza; Christiansen, Ane Sælland; Scipioni, Roberto

    2015-01-01

    Carbon black (CB) additives commonly used to increase the electrical conductivity of electrodes in Li-ion batteries are generally believed to be electrochemically inert additives in cathodes. Decomposition of electrolyte in the surface region of CB in Li-ion cells at high voltages up to 4.9 V...... is here studied using electrochemical measurements as well as structural and surface characterizations. LiPF6 and LiClO4 dissolved in ethylene carbonate:diethylene carbonate (1:1) were used as the electrolyte to study irreversible charge capacity of CB cathodes when cycled between 4.9 V and 2.5 V....... Synchrotron-based soft X-ray photoelectron spectroscopy (SOXPES) results revealed spontaneous partial decomposition of the electrolytes on the CB electrode, without applying external current or voltage. Depth profile analysis of the electrolyte/cathode interphase indicated that the concentration of decomposed...

  14. End of the Little Ice Age in the Alps forced by industrial black carbon.

    Science.gov (United States)

    Painter, Thomas H; Flanner, Mark G; Kaser, Georg; Marzeion, Ben; VanCuren, Richard A; Abdalati, Waleed

    2013-09-17

    Glaciers in the European Alps began to retreat abruptly from their mid-19th century maximum, marking what appeared to be the end of the Little Ice Age. Alpine temperature and precipitation records suggest that glaciers should instead have continued to grow until circa 1910. Radiative forcing by increasing deposition of industrial black carbon to snow may represent the driver of the abrupt glacier retreats in the Alps that began in the mid-19th century. Ice cores indicate that black carbon concentrations increased abruptly in the mid-19th century and largely continued to increase into the 20th century, consistent with known increases in black carbon emissions from the industrialization of Western Europe. Inferred annual surface radiative forcings increased stepwise to 13-17 W⋅m(-2) between 1850 and 1880, and to 9-22 W⋅m(-2) in the early 1900s, with snowmelt season (April/May/June) forcings reaching greater than 35 W⋅m(-2) by the early 1900s. These snowmelt season radiative forcings would have resulted in additional annual snow melting of as much as 0.9 m water equivalent across the melt season. Simulations of glacier mass balances with radiative forcing-equivalent changes in atmospheric temperatures result in conservative estimates of accumulating negative mass balances of magnitude -15 m water equivalent by 1900 and -30 m water equivalent by 1930, magnitudes and timing consistent with the observed retreat. These results suggest a possible physical explanation for the abrupt retreat of glaciers in the Alps in the mid-19th century that is consistent with existing temperature and precipitation records and reconstructions.

  15. Stable carbon isotope ratios: implications for the source of sediment carbon and for phytoplankton carbon assimilation in Lake Memphremagog, Quebec

    International Nuclear Information System (INIS)

    LaZerte, B.D.

    1983-01-01

    The stable carbon isotope (SCI) ratio of the sediment of Lake Memphremagog, Quebec is compared with that ot terrestrial sources and the phytoplankton to determine the relative proportion of allochthonous carbon incorporated into the sediments. Approximately 40-50% of the organic carbon in the main basins' pelagic sediment was terrestrial in origin, whereas up to 100% was terrestrial in littoral areas. The SCI method of determining the organic carbon source of sediments appears more reliable than the C/N method. A comparison of the SCI fractionation of the phytoplankton with laboratory cultures under different degrees of carbon limitation indicates that the phytoplankton of Lake Memphremagog are not carbon limited and fix carbon primarily by the C 3 pathway

  16. Electrochemical properties of arc-black and carbon nano-balloon as electrochemical capacitor electrodes

    International Nuclear Information System (INIS)

    Sato, T; Suda, Y; Uruno, H; Takikawa, H; Tanoue, H; Ue, H; Aoyagi, N; Okawa, T; Shimizu, K

    2012-01-01

    In this study, we used two types of carbon nanomaterials, arc-black (AcB) which has an amorphous structure and carbon nano-balloon (CNB) which has a graphitic structure as electrochemical capacitor electrodes. We made a coin electrode from these carbon materials and fabricated an electric double-layer capacitor (EDLC) that sandwiches a separator between the coin electrodes. On the other hand, RuO 2 was loaded on these carbon materials, and we fabricated a pseudo-capacitor that has an ion insertion mechanism into RuO 2 . For comparison with these carbon materials, activated carbon (AC) was also used for a capacitor electrode. The electrochemical properties of all the capacitors were evaluated in 1M H 2 SO 4 aqueous solution. As a result of EDLC performance, AcB electrode had a higher specific capacitance than AC electrode at a high scan rate (≥ 100 mV/s). In the evaluation of pseudo-capacitor performance, RuO 2 -loaded CNB electrode showed a high specific capacitance of 734 F/g per RuO 2 weight.

  17. Comparison of structural health assessment capabilities in epoxy – carbon black and epoxy – carbon nanotube nanocomposites

    Directory of Open Access Journals (Sweden)

    F. Inam

    2014-01-01

    Full Text Available A novel method for comparing structural health of different types of brittle epoxy nanocomposites filled with carbon nanostructured fillers is presented. Epoxy – 0.2 vol% carbon black (CB and epoxy – 0.2 vol% carbon nanotube (CNT nanocomposite bars were prepared by calendering and thermal curing. Nanocomposite bars were subjected to Vickers diamond indentation to produce sub-surface damage. Electrical conductivities were analysed by 4-point method to estimate the structural damage caused by indentation. For comprehensive comparison, fracture toughness and percolation threshold were analysed as well. Because of the systematically induced indentation damage, a sharp decrease of 89% was observed in the electrical conductivity of epoxy – CNT nanocomposite as compared to 25% in the electrical conductivity of epoxy – CB nanocomposite. CNTs impart superior damage sensing capability in brittle nanocomposite structures, in comparison to CB, due to their high aspect ratio (fibrous nature and high electrical conductivity.

  18. Black carbon reduction will weaken the aerosol net cooling effect

    Science.gov (United States)

    Wang, Z. L.; Zhang, H.; Zhang, X. Y.

    2014-12-01

    Black carbon (BC), a distinct type of carbonaceous material formed from the incomplete combustion of fossil and biomass based fuels under certain conditions, can interact with solar radiation and clouds through its strong light-absorption ability, thereby warming the Earth's climate system. Some studies have even suggested that global warming could be slowed down in a short term by eliminating BC emission due to its short lifetime. In this study, we estimate the influence of removing some sources of BC and other co-emitted species on the aerosol radiative effect by using an aerosol-climate coupled model BCC_AGCM2.0.1_CUACE/Aero, in combination with the aerosol emissions from the Representative Concentration Pathways (RCPs) scenarios. We find that the global annual mean aerosol net cooling effect at the top of the atmosphere (TOA) will be enhanced by 0.12 W m-2 compared with present-day conditions if the BC emission is reduced exclusively to the level projected for 2100 based on the RCP2.6 scenario. This will be beneficial for the mitigation of global warming. However, the global annual mean aerosol net cooling effect at the TOA will be weakened by 1.7-2.0 W m-2 relative to present-day conditions if emissions of BC and co-emitted sulfur dioxide and organic carbon are simultaneously reduced as the most close conditions to the actual situation to the level projected for 2100 in different ways based on the RCP2.6, RCP4.5, and RCP8.5 scenarios. Because there are no effective ways to remove the BC exclusively without influencing the other co-emitted components, our results therefore indicate that a reduction in BC emission can lead to an unexpected warming on the Earth's climate system in the future.

  19. Electrocatalytic Determination of Isoniazid by a Glassy Carbon Electrode Modified with Poly (Eriochrome Black T)

    OpenAIRE

    Karim Asadpour-Zeynali; Venus Baghalabadi

    2017-01-01

    In this work poly eriochrome black T (EBT) was electrochemically synthesized on the glassy carbon electrode as electrode modifier. On the modified electrode, voltammetric behavior of isoniazid (INH) was investigated. The poly (EBT)-modified glassy carbon electrode has excellent electrocatalytic ability for the electrooxidation of isoniazid. This fact was appeared as a reduced overpotential of INH oxidation in a wide operational pH range from 2 to 13. It has been found that the catalytic peak ...

  20. Joseph Black, carbon dioxide, latent heat, and the beginnings of the discovery of the respiratory gases.

    Science.gov (United States)

    West, John B

    2014-06-15

    The discovery of carbon dioxide by Joseph Black (1728-1799) marked a new era of research on the respiratory gases. His initial interest was in alkalis such as limewater that were thought to be useful in the treatment of renal stone. When he studied magnesium carbonate, he found that when this was heated or exposed to acid, a gas was evolved that he called "fixed air" because it had been combined with a solid material. He showed that the new gas extinguished a flame, that it could not support life, and that it was present in gas exhaled from the lung. Within a few years of his discovery, hydrogen, nitrogen, and oxygen were also isolated. Thus arguably Black's work started the avalanche of research on the respiratory gases carried out by Priestley, Scheele, Lavoisier, and Cavendish. Black then turned his attention to heat and he was the first person to describe latent heat, that is the heat added or lost when a liquid changes its state, for example when water changes to ice or steam. Latent heat is a key concept in thermal physiology because of the heat lost when sweat evaporates. Black was a friend of the young James Watt (1736-1819) who was responsible for the development of early steam engines. Watt was puzzled why so much cooling was necessary to condense steam into water, and Black realized that the answer was the latent heat. The resulting improvements in steam engines ushered in the Industrial Revolution. Copyright © 2014 the American Physiological Society.

  1. Changes in Snow Albedo Resulting from Snow Darkening Caused by Black Carbon

    Science.gov (United States)

    Engels, J.; Kloster, S.; Bourgeois, Q.

    2014-12-01

    We investigate the potential impact of snow darkening caused by pre-industrial and present-day black carbon (BC) emissions on snow albedo and subsequently climate. To assess this impact, we implemented the effect of snow darkening caused by BC emitted from natural as well as anthropogenic sources into the Max Planck Institute for Meteorology Earth System Model (MPI-M ESM). Considerable amounts of BC are emitted e.g. from fires and are transported through the atmosphere for several days before being removed by rain or snow precipitation in snow covered regions. Already very small quantities of BC reduce the snow reflectance significantly, with consequences for snow melting and snow spatial coverage. We implemented the snow albedo reduction caused by BC contamination and snow aging in the one layer land surface component (JSBACH) of the atmospheric general circulation model ECHAM6, developed at MPI-M. For this we used the single-layer simulator of the SNow, Ice, and Aerosol Radiation (SNICAR-Online (Flanner et al., 2007); http://snow.engin.umich.edu) model to derive snow albedo values for BC in snow concentrations ranging between 0 and 1500 ng(BC)/g(snow) for different snow grain sizes for the visible (0.3 - 0.7 μm) and near infrared range (0.7 - 1.5 μm). As snow grains grow over time, we assign different snow ages to different snow grain sizes (50, 150, 500, and 1000 μm). Here, a radius of 50 μm corresponds to new snow, whereas a radius of 1000 μm corresponds to old snow. The deposition rates of BC on snow are prescribed from previous ECHAM6-HAM simulations for two time periods, pre-industrial (1880-1889) and present-day (2000-2009), respectively. We perform a sensitivity study regarding the scavenging of BC by snow melt. To evaluate the newly implemented albedo scheme we will compare the modeled black carbon in snow concentrations to observed ones. Moreover, we will show the impact of the BC contamination and snow aging on the simulated snow albedo. The

  2. Imparting improvements in electrochemical sensors: evaluation of different carbon blacks that give rise to significant improvement in the performance of electroanalytical sensing platforms

    International Nuclear Information System (INIS)

    Vicentini, Fernando Campanhã; Ravanini, Amanda E.; Figueiredo-Filho, Luiz C.S.; Iniesta, Jesús; Banks, Craig E.; Fatibello-Filho, Orlando

    2015-01-01

    Three different carbon black materials have been evaluated as a potential modifier, however, only one demonstrated an improvement in the electrochemical properties. The carbon black structures were characterised with SEM, XPS and Raman spectroscopy and found to be very similar to that of amorphous graphitic materials. The modifications utilised were constructed by three different strategies (using ultrapure water, chitosan and dihexadecylphosphate). The fabricated sensors are electrochemically characterised using N,N,N',N'-tetramethyl-para-phenylenediamine and both inner-sphere and outer-sphere redox probes, namely potassium ferrocyanide(II) and hexaammineruthenium(III) chloride, in addition to the biologically relevant and electroactive analytes, dopamine (DA) and acetaminophen (AP). Comparisons are made with an edge-plane pyrolytic graphite and glassy-carbon electrode and the benefits of carbon black implemented as a modifier for sensors within electrochemistry are explored, as well as the characterisation of their electroanalytical performances. We reveal significant improvements in the electrochemical performance (excellent sensitivity, faster heterogeneous electron transfer rate (HET)) over that of a bare glassy-carbon and edge-plane pyrolytic graphite electrode and thus suggest that there are substantial advantages of using carbon black as modifier in the fabrication of electrochemical based sensors. Such work is highly important and informative for those working in the field of electroanalysis where electrochemistry can provide portable, rapid, reliable and accurate sensing protocols (bringing the laboratory into the field), with particular relevance to those searching for new electrode materials

  3. Black Carbon Inclusive Multichemical Modeling of PBDE and PCB Biomagnification and -Transformation in Estuarine Food Webs

    NARCIS (Netherlands)

    Paolo, C.; Gandhi, N.; Bhavsar, S.; Heuvel-Greve, van den M.J.; Koelmans, A.A.

    2010-01-01

    Bioavailability and bioaccumulation of polybrominated diphenylethers (PBDEs) are affected by adsorption on black carbon (BC) and metabolism in biota, respectively. Recent studies have addressed these two processes separately, illustrating their importance in assessing contaminant dynamics. In order

  4. Gravitational lensing of transient neutrino sources by black holes

    Energy Technology Data Exchange (ETDEWEB)

    Eiroa, Ernesto F. [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria Pab. I, 1428 Buenos Aires (Argentina); Instituto de Astronomia y Fisica del Espacio, C.C. 67, Suc. 28, 1428 Buenos Aires (Argentina)], E-mail: eiroa@iafe.uba.ar; Romero, Gustavo E. [Instituto Argentino de Radioastronomia (IAR-CONICET), C.C.5, 1894 Villa Elisa, Buenos Aires (Argentina); Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, Paseo del Bosque, 1900 La Plata (Argentina)], E-mail: romero@iar-conicet.gov.ar

    2008-06-05

    In this work we study gravitational lensing of neutrinos by Schwarzschild black holes. In particular, we analyze the case of a neutrino transient source associated with a gamma-ray burst lensed by a supermassive black hole located at the center of an interposed galaxy. We show that the primary and secondary images have an angular separation beyond the resolution of forthcoming km-scale detectors, but the signals from each image have time delays between them that in most cases are longer than the typical duration of the intrinsic events. In this way, the signal from different images can be detected as separate events coming from the very same location in the sky. This would render an event that otherwise might have had a low signal-to-noise ratio a clear detection, since the probability of a repetition of a signal from the same direction is negligible. The relativistic images are so faint and proximate that are beyond the sensitivity and resolution of the next-generation instruments.

  5. Temporal variations of black carbon in Guangzhou, China, in summer 2006

    Directory of Open Access Journals (Sweden)

    R. L. Verma

    2010-07-01

    Full Text Available In situ measurements of the mass concentration of black carbon (BC and mixing ratios of carbon monoxide (CO and carbon dioxide (CO2 were made at Guangzhou, an urban measurement site in the Pearl River Delta (PRD, China, in July 2006. The average ± standard deviation (SD concentrations of BC, CO, and CO2 were 4.7± 2.3 μgC m−3, 798± 459 ppbv, and 400± 13 ppmv, respectively. The trends of these species were mainly controlled by synoptic-scale changes in meteorology during the campaign. Based on back trajectories, data are analyzed separately for two different air mass types representing northerly and southerly flows. The northerly air masses, which constituted ~25% of the campaign, originated mostly in the PRD and hence represent observations on regional scales. On the other hand, during southerly flow (~75%, the measurements were influenced by dilution due to cleaner marine air. The diurnal patterns of BC, CO, and CO2 exhibited peak concentrations during the morning and evening hours coinciding with rush-hour traffic. The ratios of OC/BC were lower during the morning hour peaks in the concentrations of primary pollutants due to their fresh emissions mainly from vehicular traffic in Guangzhou. The diurnal variations of BC observed in southerly air masses tended to follow the traffic patterns of heavy-duty vehicles (HDV in Guangzhou, while the roles of other sources need to be investigated. The slopes of ΔBC/ΔCO, ΔBC/ΔCO2, and ΔCO/ΔCO2 observed during northerly flows were 0.0045 μgC m−3/ppbv, 0.13 μgC m−3/ppmv, and 49.4 ppbv/ppmv, respectively, agreeing reasonably with their respective emission ratios derived from regional emission inventories.

  6. The microstructure and morphology of carbon black: A study using small angle neutron scattering and contrast variation

    International Nuclear Information System (INIS)

    Hjelm, R.P. Jr.; Seeger, P.A.; Wampler, W.A.; Gerspacher, M.

    1994-01-01

    This is a study of the microstructure of particles of an experimental high surface area carbon black (HSA) and of the morphology of the particle aggregates using small-angle neutron scattering and the method of contrast variation. Contrast variation was effected by studying suspensions of the carbon black in cyclohexane containing different fractions of deuterocyclohexane. We find that the approximately 29 nm diameter HSA particles are arranged as small, linear aggregates with average aggregation number between 4 and 6. The structure averaged over the particle population is best represented by a prolate ellipsoid of revolution with semi axes 14.5 and 76.4 nm. The surface of the aggregates appears smooth over length scales longer than 1 nm, which places an upper limit on the surface roughness observed by other methods. The intemal structure of the aggregates is described by a shell-core model, with the shell density being consistent with a graphitic structure and the core being of lower density, more like amorphous carbon. Some fraction of the core volume (0.1 to 0.2) is taken up by voids that are not accessible to the solvent. An estimate of the shell thickness gives 1 to 2 nm along the ellipsoid minor axis and 6 to 10 nm along the major axis. The particles of the aggregate appear to be fused so that the less dense amorphous core is continuous through the inner parts of the aggregate. The information that can be obtained on the internal structure using contrast variation is limited by nonheterogeneity in the chemical composition of carbon black aggregates

  7. Are emissions of black carbon from gasoline vehicles underestimated? Insights from near and on-road measurements.

    Science.gov (United States)

    Liggio, John; Gordon, Mark; Smallwood, Gregory; Li, Shao-Meng; Stroud, Craig; Staebler, Ralf; Lu, Gang; Lee, Patrick; Taylor, Brett; Brook, Jeffrey R

    2012-05-01

    Measurements of black carbon (BC) with a high-sensitivity laser-induced incandescence (HS-LII) instrument and a single particle soot photometer (SP2) were conducted upwind, downwind, and while driving on a highway dominated by gasoline vehicles. The results are used with concurrent CO(2) measurements to derive fuel-based BC emission factors for real-world average fleet and heavy-duty diesel vehicles separately. The derived emission factors from both instruments are compared, and a low SP2 bias (relative to the HS-LII) is found to be caused by a BC mass mode diameter less than 75 nm, that is most prominent with the gasoline fleet but is not present in the heavy-duty diesel vehicle exhaust on the highway. Results from both the LII and the SP2 demonstrate that the BC emission factors from gasoline vehicles are at least a factor of 2 higher than previous North American measurements, and a factor of 9 higher than currently used emission inventories in Canada, derived with the MOBILE 6.2C model. Conversely, the measured BC emission factor for heavy-duty diesel vehicles is in reasonable agreement with previous measurements. The results suggest that greater attention must be paid to black carbon from gasoline engines to obtain a full understanding of the impact of black carbon on air quality and climate and to devise appropriate mitigation strategies. © 2012 American Chemical Society

  8. Ordered mesoporous carbon coating on cordierite: Synthesis and application as an efficient adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Ying, E-mail: ywan@shnu.edu.cn [Key Laboratory of Resource Chemistry of Ministry of Education, Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234 (China); Department of Chemistry, Shanghai Normal University, Shanghai 200234 (China); Cui, Xiangting; Wen, Zhentao [Department of Chemistry, Shanghai Normal University, Shanghai 200234 (China)

    2011-12-30

    Highlight: Black-Right-Pointing-Pointer Surfactant self-assembly of ordered mesoporous carbon coating on honeycomb cordierite. Black-Right-Pointing-Pointer Carbon coating with opened, hexagonally ordered pore arrays. Black-Right-Pointing-Pointer Honeycomb adsorbents for removal of p-chlorophenol. Black-Right-Pointing-Pointer The adsorbents exhibit large processing volume, and great advantages in reusability. - Abstract: Ordered mesoporous carbon coating on the honeycomb cordierite substrate has been prepared using low-polymerized phenolic resins as carbon sources and triblock copolymer F127 as the structure directing agent via the evaporation induced self-assembly route. The high-resolution scanning electron microscopy (HRSEM), transmission electron microscopy (TEM), and nitrogen sorption techniques prove the hexagonally ordered pore arrays of carbon coating on the cordierite. The honeycomb monolith adsorbents coated by ordered mesoporous carbons are directly used without any activation, and exhibit adsorption capacities for chlorinated organic pollutants in water with 200 mg/g for p-chlorophenol and 178 mg/g for p-chloroaniline (with respect to the net carbon coating), high adsorption ratio for low-concentration pollutants, large processing volumes and reusability. More than 200 repeated times can be achieved without obvious loss in both adsorption capacity and weight.

  9. Monthly and spatially resolved black carbon emission inventory of India: uncertainty analysis

    Directory of Open Access Journals (Sweden)

    U. Paliwal

    2016-10-01

    Full Text Available Black carbon (BC emissions from India for the year 2011 are estimated to be 901.11 ± 151.56 Gg yr−1 based on a new ground-up, GIS-based inventory. The grid-based, spatially resolved emission inventory includes, in addition to conventional sources, emissions from kerosene lamps, forest fires, diesel-powered irrigation pumps and electricity generators at mobile towers. The emissions have been estimated at district level and were spatially distributed onto grids at a resolution of 40 × 40 km2. The uncertainty in emissions has been estimated using a Monte Carlo simulation by considering the variability in activity data and emission factors. Monthly variation of BC emissions has also been estimated to account for the seasonal variability. To the total BC emissions, domestic fuels contributed most significantly (47 %, followed by industry (22 %, transport (17 %, open burning (12 % and others (2 %. The spatial and seasonal resolution of the inventory will be useful for modeling BC transport in the atmosphere for air quality, global warming and other process-level studies that require greater temporal resolution than traditional inventories.

  10. Temporally delineated sources of major chemical species in high Arctic snow

    Directory of Open Access Journals (Sweden)

    K. M. Macdonald

    2018-03-01

    Full Text Available Long-range transport of aerosol from lower latitudes to the high Arctic may be a significant contributor to climate forcing in the Arctic. To identify the sources of key contaminants entering the Canadian High Arctic an intensive campaign of snow sampling was completed at Alert, Nunavut, from September 2014 to June 2015. Fresh snow samples collected every few days were analyzed for black carbon, major ions, and metals, and this rich data set provided an opportunity for a temporally refined source apportionment of snow composition via positive matrix factorization (PMF in conjunction with FLEXPART (FLEXible PARTicle dispersion model potential emission sensitivity analysis. Seven source factors were identified: sea salt, crustal metals, black carbon, carboxylic acids, nitrate, non-crustal metals, and sulfate. The sea salt and crustal factors showed good agreement with expected composition and primarily northern sources. High loadings of V and Se onto Factor 2, crustal metals, was consistent with expected elemental ratios, implying these metals were not primarily anthropogenic in origin. Factor 3, black carbon, was an acidic factor dominated by black carbon but with some sulfate contribution over the winter-haze season. The lack of K+ associated with this factor, a Eurasian source, and limited known forest fire events coincident with this factor's peak suggested a predominantly anthropogenic combustion source. Factor 4, carboxylic acids, was dominated by formate and acetate with a moderate correlation to available sunlight and an oceanic and North American source. A robust identification of this factor was not possible; however, atmospheric photochemical reactions, ocean microlayer reaction, and biomass burning were explored as potential contributors. Factor 5, nitrate, was an acidic factor dominated by NO3−, with a likely Eurasian source and mid-winter peak. The isolation of NO3− on a separate factor may reflect its complex atmospheric

  11. Bacterial-viral interactions in the sea surface microlayer of a black carbon-dominated tropical coastal ecosystem (Halong Bay, Vietnam

    Directory of Open Access Journals (Sweden)

    A. S. Pradeep Ram

    2018-02-01

    Full Text Available Increasing human activity has raised concerns about the impact of deposition of anthropogenic combustion aerosols (i.e., black carbon; BC on marine processes. The sea surface microlayer (SML is a key gate for the introduction of atmospheric BC into the ocean; however, relatively little is known of the effects of BC on bacteria-virus interactions, which can strongly influence microbially mediated processes. To study the impact of BC on bacteria-virus interactions, field investigations involving collection from the SML and underlying water were carried out in Halong Bay (Vietnam. Most inorganic nutrient concentrations, as well as dissolved organic carbon, were modestly but significantly higher ('p' = 0.02–0.05 in the SML than in underlying water. The concentrations of particulate organic carbon (though not chlorophyll 'a' and of total particulate carbon, which was composed largely of particulate BC (mean = 1.7 ± 6.4 mmol L–1, were highly enriched in the SML, and showed high variability among stations. On average, microbial abundances (both bacteria and viruses and bacterial production were 2- and 5fold higher, respectively, in the SML than in underlying water. Significantly lower bacterial production ('p' 3 μm compared to the bulk sample, but our data overall suggest that bacterial production in the SML was stimulated by particulate BC. Higher bacterial production in the SML than in underlying water supported high viral lytic infection rates (from 5.3 to 30.1% which predominated over percent lysogeny (from undetected to 1.4%. The sorption of dissolved organic carbon by black carbon, accompanied by the high lytic infection rate in the black carbon-enriched SML, may modify microbially mediated processes and shift the net ecosystem metabolism (ratio of production and respiration to net heterotrophy and CO2 production in this critical layer between ocean and atmosphere.

  12. Processing and characterization of a carbon black-filled electrically conductive Nylon-12 nanocomposite produced by selective laser sintering

    International Nuclear Information System (INIS)

    Athreya, Siddharth Ram; Kalaitzidou, Kyriaki; Das, Suman

    2010-01-01

    Selective laser sintering (SLS), a layered manufacturing technique was explored to process an electrically conductive polymer nanocomposite made of Nylon-12 reinforced with 4 wt% of carbon black. SLS process parameters were optimized in order to maximize the flexural modulus. The porosity and morphology were studied using optical microscopy and scanning electron microscopy (SEM). The crystalline state was characterized using differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The electrical conductivity was determined using the four probe technique. Results indicate that carbon black-filled Nylon-12 nanocomposites can be successfully made by SLS. Maximum flexural modulus values of 1750 MPa and 1450 MPa were achieved for the neat polymer and the nanocomposite, respectively. A reduction in the flexural modulus of the nanocomposite is likely due to the formation of a segregated structure in the nanocomposite and a weak polymer-filler interface. The optimized neat polymer and the nanocomposites had average densities of around 97% and 96% relative to full density, respectively. The electrical conductivity of the nanocomposite was approximately 1 x 10 -4 S/cm, which is five orders of magnitude higher than that of the neat polymer processed by SLS, and indicates that the onset of percolation behavior occurs below the 4 wt% loading of carbon black.

  13. Origin and radiative forcing of black carbon transported to the Himalayas and Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    M. Kopacz

    2011-03-01

    Full Text Available The remote and high elevation regions of central Asia are influenced by black carbon (BC emissions from a variety of locations. BC deposition contributes to melting of glaciers and questions exist, of both scientific and policy interest, as to the origin of the BC reaching the glaciers. We use the adjoint of the GEOS-Chem model to identify the location from which BC arriving at a variety of locations in the Himalayas and Tibetan Plateau originates. We then calculate its direct and snow-albedo radiative forcing. We analyze the seasonal variation in the origin of BC using an adjoint sensitivity analysis, which provides a detailed map of the location of emissions that directly contribute to black carbon concentrations at receptor locations. We find that emissions from northern India and central China contribute the majority of BC to the Himalayas, although the precise location varies with season. The Tibetan Plateau receives most BC from western and central China, as well as from India, Nepal, the Middle East, Pakistan and other countries. The magnitude of contribution from each region varies with season and receptor location. We find that sources as varied as African biomass burning and Middle Eastern fossil fuel combustion can significantly contribute to the BC reaching the Himalayas and Tibetan Plateau. We compute radiative forcing in the snow-covered regions and find the forcing due to the BC induced snow-albedo effect to vary from 5–15 W m−2 within the region, an order of magnitude larger than radiative forcing due to the direct effect, and with significant seasonal variation in the northern Tibetan Plateau. Radiative forcing from reduced snow albedo likely accelerates glacier melting. Our analysis may help inform mitigation efforts to slow the rate of glacial melt by identifying regions that make the largest contributions to BC deposition in the Himalayas and Tibetan Plateau.

  14. Grafting the surface of carbon nanotubes and carbon black with the chemical properties of hyperbranched polyamines

    Science.gov (United States)

    Morales-Lara, Francisco; Domingo-García, María; López-Garzón, Rafael; Luz Godino-Salido, María; Peñas-Sanjuán, Antonio; López-Garzón, F. Javier; Pérez-Mendoza, Manuel; Melguizo, Manuel

    2016-01-01

    Controlling the chemistry on the surface of new carbon materials is a key factor to widen the range of their applicability. In this paper we show a grafting methodology of polyalkylamines to the surface of carbon nanomaterials, in particular, carbon nanotubes and a carbon black. The aim of this work is to reach large degrees of covalent functionalization with hyperbranched polyethyleneimines (HBPEIs) and to efficiently preserve the strong chelating properties of the HBPEIs when they are fixed to the surface of these carbon materials. This functionalization opens new possibilities of using these carbon nanotubes-based hybrids. The results show that the HBPEIs are covalently attached to the carbon materials, forming hybrids. These hybrids emerge from the reaction of amine functions of the HBPEIs with carbonyls and carboxylic anhydrides of the carbon surface which become imine and imide bonds. Thus, due to the nature of these bonds, the pre-oxidized samples with relevant number of C=O groups showed an increase in the degree of functionalization with the HBPEIs. Furthermore, both the acid-base properties and the coordination capacity for metal ions of the hybrids are equivalent to that of the free HBPEIs in solution. This means that the chemical characteristics of the HBPEIs have been efficiently transferred to the hybrids. To reach this conclusion we have developed a novel procedure to assess the acid-base and the coordination properties of the hybrids (solids) by means of potentiometric titration. The good agreement of the values obtained for the hybrids and for the free HBPEIs in aqueous solution supports the reliability of the procedure. Moreover, the high capacity of the hybrids to capture Ni2+ by complexation opens new possibilities of using these hybrids to capture high-value metal ions such as Pd2+ and Pt2+.

  15. Seasonality of global and Arctic black carbon processes in the Arctic Monitoring and Assessment Programme models: Global and Arctic Black Carbon Processes

    Energy Technology Data Exchange (ETDEWEB)

    Mahmood, Rashed [School of Earth and Ocean Sciences, University of Victoria, Victoria British Columbia Canada; Department of Meteorology, COMSATS Institute of Information Technology, Islamabad Pakistan; von Salzen, Knut [School of Earth and Ocean Sciences, University of Victoria, Victoria British Columbia Canada; Canadian Center for Climate Modelling and Analysis, Environment and Climate Change Canada, University of Victoria, Victoria British Columbia Canada; Flanner, Mark [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor Michigan USA; Sand, Maria [Center for International Climate and Environmental Research-Oslo, Oslo Norway; Langner, Joakim [Swedish Meteorological and Hydrological Institute, Norrköping Sweden; Wang, Hailong [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA; Huang, Lin [Climate Chemistry Measurements and Research, Environment and Climate Change Canada, Toronto Ontario Canada

    2016-06-22

    This study quantifies black carbon (BC) processes in three global climate models and one chemistry transport model, with focus on the seasonality of BC transport, emissions, wet and dry deposition in the Arctic. In the models, transport of BC to the Arctic from lower latitudes is the major BC source for this region while Arctic emissions are very small. All models simulated a similar annual cycle of BC transport from lower latitudes to the Arctic, with maximum transport occurring in July. Substantial differences were found in simulated BC burdens and vertical distributions, with CanAM (NorESM) producing the strongest (weakest) seasonal cycle. CanAM also has the shortest annual mean residence time for BC in the Arctic followed by SMHI-MATCH, CESM and NorESM. The relative contribution of wet and dry deposition rates in removing BC varies seasonally and is one of the major factors causing seasonal variations in BC burdens in the Arctic. Overall, considerable differences in wet deposition efficiencies in the models exist and are a leading cause of differences in simulated BC burdens. Results from model sensitivity experiments indicate that scavenging of BC in convective clouds acts to substantially increase the overall efficiency of BC wet deposition in the Arctic, which leads to low BC burdens and a more pronounced seasonal cycle compared to simulations without convective BC scavenging. In contrast, the simulated seasonality of BC concentrations in the upper troposphere is only weakly influenced by wet deposition in stratiform (layer) clouds whereas lower tropospheric concentrations are highly sensitive.

  16. Soot on snow in Iceland: First results on black carbon and organic carbon in Iceland 2016 snow and ice samples, including the glacier Solheimajökull

    Science.gov (United States)

    Meinander, Outi; Dagsson-Waldhauserova, Pavla; Gritsevich, Maria; Aurela, Minna; Arnalds, Olafur; Dragosics, Monika; Virkkula, Aki; Svensson, Jonas; Peltoniemi, Jouni; Kontu, Anna; Kivekäs, Niku; Leppäranta, Matti; de Leeuw, Gerrit; Laaksonen, Ari; Lihavainen, Heikki; Arslan, Ali N.; Paatero, Jussi

    2017-04-01

    New results on black carbon (BC) and organic carbon (OC) on snow and ice in Iceland in 2016 will be presented in connection to our earlier results on BC and OC on Arctic seasonal snow surface, and in connection to our 2013 and 2016 experiments on effects of light absorbing impurities, including Icelandic dust, on snow albedo, melt and density. Our sampling included the glacier Solheimajökull in Iceland. The mass balance of this glacier is negative and it has been shrinking during the last 20 years by 900 meters from its southwestern corner. Icelandic snow and ice samples were not expected to contain high concentrations of BC, as power generation with domestic renewable water and geothermal power energy sources cover 80 % of the total energy consumption in Iceland. Our BC results on filters analyzed with a Thermal/Optical Carbon Aerosol Analyzer (OC/EC) confirm this assumption. Other potential soot sources in Iceland include agricultural burning, industry (aluminum and ferroalloy production and fishing industry), open burning, residential heating and transport (shipping, road traffic, aviation). On the contrary to low BC, we have found high concentrations of organic carbon in our Iceland 2016 samples. Some of the possible reasons for those will be discussed in this presentation. Earlier, we have measured and reported unexpectedly low snow albedo values of Arctic seasonally melting snow in Sodankylä, north of Arctic Circle. Our low albedo results of melting snow have been confirmed by three independent data sets. We have explained these low values to be due to: (i) large snow grain sizes up to 3 mm in diameter (seasonally melting snow); (ii) meltwater surrounding the grains and increasing the effective grain size; (iii) absorption caused by impurities in the snow, with concentration of elemental carbon (black carbon) in snow of 87 ppb, and organic carbon 2894 ppb. The high concentrations of carbon were due to air masses originating from the Kola Peninsula, Russia

  17. Black carbon content in a ponderosa pine forest of eastern Oregon with varying seasons and intervals of prescribed burns

    Science.gov (United States)

    Matosziuk, L.; Hatten, J. A.

    2016-12-01

    Soil carbon represents a significant component of the global carbon cycle. While fire-based disturbance of forest ecosystems acts as a carbon source, the increased temperatures can initiate molecular changes to forest biomass that convert fast cycling organic carbon into more stable forms such as black carbon (BC), a product of incomplete combustion that contains highly-condensed aromatic structures and very low hydrogen and oxygen content. Such forms of carbon can remain in the soil for hundred to thousands of years, effectively creating a long-term carbon sink. The goal of this project is to understand how specific characteristics of prescribed burns, specifically the season of burn and the interval between burns, affect the formation, structure, and retention of these slowly degrading forms of carbon in the soil. Both O-horizon (forest floor) and mineral soil (0-15 cm cores) samples were collected from a season and interval of burn study in Malheur National Forest. The study area is divided into six replicate units, each of which is sub-divided into four treatment areas and a control. Beginning in 1997, each treatment area was subjected to: i) spring burns at five-year intervals, ii) fall burns at five-year intervals, iii) spring burns at 15-year intervals, or iv) fall burns at 15-year intervals. The bulk density, pH, and C/N content of each soil were measured to assess the effect of the burn treatments on the soil. Additionally, the amount and molecular structure of BC in each sample was quantified using the distribution of specific molecular markers (benzene polycarboxylic acids or BPCAs) that are present in the soil following acid digestion.

  18. Long-term trends of black carbon and sulphate aerosol in the Arctic: changes in atmospheric transport and source region emissions

    Directory of Open Access Journals (Sweden)

    D. Hirdman

    2010-10-01

    Full Text Available As a part of the IPY project POLARCAT (Polar Study using Aircraft, Remote Sensing, Surface Measurements and Models, of Climate, Chemistry, Aerosols and Transport and building on previous work (Hirdman et al., 2010, this paper studies the long-term trends of both atmospheric transport as well as equivalent black carbon (EBC and sulphate for the three Arctic stations Alert, Barrow and Zeppelin. We find a general downward trend in the measured EBC concentrations at all three stations, with a decrease of −2.1±0.4 ng m−3 yr−1 (for the years 1989–2008 and −1.4±0.8 ng m−3 yr−1 (2002–2009 at Alert and Zeppelin respectively. The decrease at Barrow is, however, not statistically significant. The measured sulphate concentrations show a decreasing trend at Alert and Zeppelin of −15±3 ng m−3 yr−1 (1985–2006 and −1.3±1.2 ng m−3 yr−1 (1990–2008 respectively, while there is no trend detectable at Barrow.

    To reveal the contribution of different source regions on these trends, we used a cluster analysis of the output of the Lagrangian particle dispersion model FLEXPART run backward in time from the measurement stations. We have investigated to what extent variations in the atmospheric circulation, expressed as variations in the frequencies of the transport from four source regions with different emission rates, can explain the long-term trends in EBC and sulphate measured at these stations. We find that the long-term trend in the atmospheric circulation can only explain a minor fraction of the overall downward trend seen in the measurements of EBC (0.3–7.2% and sulphate (0.3–5.3% at the Arctic stations. The changes in emissions are dominant in explaining the trends. We find that the highest EBC and sulphate concentrations are associated with transport from Northern Eurasia and decreasing emissions in this region drive the

  19. Uptake mechanism for iodine species to black carbon.

    Science.gov (United States)

    Choung, Sungwook; Um, Wooyong; Kim, Minkyung; Kim, Min-Gyu

    2013-09-17

    Natural organic matter (NOM) plays an important role in determining the fate and transport of iodine species such as iodide (I(-)) and iodate (IO3(-)) in groundwater system. Although NOM exists as diverse forms in environments, prior iodine studies have mainly focused on uptake processes of iodide and iodate to humic materials. This study was conducted to determine the iodide and iodate uptake potential for a particulate NOM (i.e., black carbon [BC]). A laboratory-produced BC and commercial humic acid were used for batch experiments to compare their iodine uptake properties. The BC exhibited >100 times greater uptake capability for iodide than iodate at low pH of ~3, while iodide uptake was negligible for the humic acid. The uptake properties of both solids strongly depend on the initial iodine aqueous concentrations. After uptake reaction of iodide to the BC, X-ray absorption fine structure spectroscopy results indicated that the iodide was converted to electrophilic species, and iodine was covalently bound to carbon atom in polycyclic aromatic hydrocarbons present in the BC. The computed distribution coefficients (i.e., Kd values) suggest that the BC materials retard significantly the transport of iodide at low pH in environmental systems containing even a small amount of BC.

  20. Lead chromate detected as a source of atmospheric Pb and Cr (VI) pollution

    Science.gov (United States)

    Lee, Pyeong-Koo; Yu, Soonyoung; Chang, Hye Jung; Cho, Hye Young; Kang, Min-Ju; Chae, Byung-Gon

    2016-10-01

    Spherical black carbon aggregates were frequently observed in dust dry deposition in Daejeon, Korea. They were tens of micrometers in diameter and presented a mixture of black carbon and several mineral phases. Transmission electron microscopy (TEM) observations with energy-dispersive X-ray spectroscopy (EDS) and selected area diffraction pattern (SADP) analyses confirmed that the aggregates were compact and included significant amounts of lead chromate (PbCrO4). The compositions and morphologies of the nanosized lead chromate particles suggest that they probably originated from traffic paint used in roads and were combined as discrete minerals with black carbon. Based on Pb isotope analysis and air-mass backward trajectories, the dust in Daejeon received a considerable input of anthropogenic pollutants from heavily industrialized Chinese cities, which implies that long-range transported aerosols containing PbCrO4 were a possible source of the lead and hexavalent chromium levels in East Asia. Lead chromate should be considered to be a source of global atmospheric Pb and Cr(VI) pollution, especially given its toxicity.

  1. Lead chromate detected as a source of atmospheric Pb and Cr (VI) pollution.

    Science.gov (United States)

    Lee, Pyeong-Koo; Yu, Soonyoung; Chang, Hye Jung; Cho, Hye Young; Kang, Min-Ju; Chae, Byung-Gon

    2016-10-25

    Spherical black carbon aggregates were frequently observed in dust dry deposition in Daejeon, Korea. They were tens of micrometers in diameter and presented a mixture of black carbon and several mineral phases. Transmission electron microscopy (TEM) observations with energy-dispersive X-ray spectroscopy (EDS) and selected area diffraction pattern (SADP) analyses confirmed that the aggregates were compact and included significant amounts of lead chromate (PbCrO 4 ). The compositions and morphologies of the nanosized lead chromate particles suggest that they probably originated from traffic paint used in roads and were combined as discrete minerals with black carbon. Based on Pb isotope analysis and air-mass backward trajectories, the dust in Daejeon received a considerable input of anthropogenic pollutants from heavily industrialized Chinese cities, which implies that long-range transported aerosols containing PbCrO 4 were a possible source of the lead and hexavalent chromium levels in East Asia. Lead chromate should be considered to be a source of global atmospheric Pb and Cr(VI) pollution, especially given its toxicity.

  2. Black and brown carbon fractal aggregates from combustion of two fuels widely used in Asian rituals

    International Nuclear Information System (INIS)

    Chakrabarty, Rajan K.; Arnold, Ian J.; Francisco, Dianna M.; Hatchett, Benjamin; Hosseinpour, Farnaz; Loria, Marcela; Pokharel, Ashok; Woody, Brian M.

    2013-01-01

    Incense sticks and mustard oil are the two most popular combustion fuels during rituals and social ceremonies in Asian countries. Given their widespread use in both closed and open burning activities, it is important to quantify the spectral radiative properties of aerosols emitted from the combustion of both fuels. This information is needed by climate models to assess the impact of these aerosols on radiative forcing. In this study, we used a 3-wavelength integrated photoacoustic-nephelometer – operating simultaneously at 405, 532 and 781 nm – to measure the optical coefficients of aerosols emitted from the laboratory combustion of mustard oil lamp and two types of incense sticks. From the measured optical coefficients at three wavelengths, time-varying single scattering albedo (SSA), absorption Ångström exponent (AAE), and scattering Ångström exponent (SAE) were calculated. For incense smoke particles, the time-averaged mean AAE values were found to be as high as 8.32 (between 405 and 532 nm) and 6.48 (between 532 and 781 nm). This spectrally-varying characteristic of AAE indicates that brown carbon – a class of organic carbon which strongly absorbs solar radiation in the blue and near ultraviolet – is the primary component of incense smoke aerosols. For aerosols emitted from the burning of mustard oil lamp, the time-averaged mean AAE values were ∼1.3 (between 405 and 781 nm) indicating that black carbon (BC) is the primary constituent. Scanning electron microscopy combined with image processing revealed the morphology of incense smoke aerosols to be non-coalescing and weakly-bound aggregates with a mean two-dimensional (2-d) fractal dimension (D f )=1.9±0.07, while the mustard oil smoke aerosols had typical fractal-like BC aggregate morphology with a mean 2-d D f =1.85±0.09. -- Highlights: ► Incense and mustard oil burning aerosols characterized by 3-wavelength photoacoustic spectroscopy and nephelometery, and electron microscopy. ► Brown

  3. Carbon Sources for Polyhydroxyalkanoates and an Integrated Biorefinery

    Directory of Open Access Journals (Sweden)

    Guozhan Jiang

    2016-07-01

    Full Text Available Polyhydroxyalkanoates (PHAs are a group of bioplastics that have a wide range of applications. Extensive progress has been made in our understanding of PHAs’ biosynthesis, and currently, it is possible to engineer bacterial strains to produce PHAs with desired properties. The substrates for the fermentative production of PHAs are primarily derived from food-based carbon sources, raising concerns over the sustainability of their production in terms of their impact on food prices. This paper gives an overview of the current carbon sources used for PHA production and the methods used to transform these sources into fermentable forms. This allows us to identify the opportunities and restraints linked to future sustainable PHA production. Hemicellulose hydrolysates and crude glycerol are identified as two promising carbon sources for a sustainable production of PHAs. Hemicellulose hydrolysates and crude glycerol can be produced on a large scale during various second generation biofuels’ production. An integration of PHA production within a modern biorefinery is therefore proposed to produce biofuels and bioplastics simultaneously. This will create the potential to offset the production cost of biofuels and reduce the overall production cost of PHAs.

  4. Carbon Sources for Polyhydroxyalkanoates and an Integrated Biorefinery.

    Science.gov (United States)

    Jiang, Guozhan; Hill, David J; Kowalczuk, Marek; Johnston, Brian; Adamus, Grazyna; Irorere, Victor; Radecka, Iza

    2016-07-19

    Polyhydroxyalkanoates (PHAs) are a group of bioplastics that have a wide range of applications. Extensive progress has been made in our understanding of PHAs' biosynthesis, and currently, it is possible to engineer bacterial strains to produce PHAs with desired properties. The substrates for the fermentative production of PHAs are primarily derived from food-based carbon sources, raising concerns over the sustainability of their production in terms of their impact on food prices. This paper gives an overview of the current carbon sources used for PHA production and the methods used to transform these sources into fermentable forms. This allows us to identify the opportunities and restraints linked to future sustainable PHA production. Hemicellulose hydrolysates and crude glycerol are identified as two promising carbon sources for a sustainable production of PHAs. Hemicellulose hydrolysates and crude glycerol can be produced on a large scale during various second generation biofuels' production. An integration of PHA production within a modern biorefinery is therefore proposed to produce biofuels and bioplastics simultaneously. This will create the potential to offset the production cost of biofuels and reduce the overall production cost of PHAs.

  5. Flux, Budget and Sources of Black Carbon (BC) in the Continental Shelf of the Bohai and Yellow Seas, China

    Science.gov (United States)

    Fang, Y.; Chen, Y.; Tian, C.

    2015-12-01

    Black carbon (BC) derived from incomplete combustion of fossil fuels and biomass has received increasing attention due to their potential importance in a wide range of biogeochemical processes. China has been generally considered as the world's largest BC emitter. Due to a combination of the prevailing East Asia monsoon and large amounts of riverine outflow, BC released from China can be transported to the adjacent continental shelf seas, the Bohai Sea (BS) and Yellow Sea (YS). Based on measurements of BC in 191 surface sediments, 36 riverine water, and 2 seawater samples, as well as the reported BC data set of the aerosol samples in the Bohai Rim, the concentration, flux, and budget of BC in the BS and YS were investigated. The spatial distribution of the BC concentration in surface sediments was largely influenced by the regional hydrodynamic conditions, with high values mainly occurring in the central mud areas. The BC burial flux in the BS and YS ranged from 4 to 1100 μg/cm2/yr, and averaged 166 ± 200 μg/cm2/yr. The area-integrated sedimentary BC sink flux in the entire BS and YS was ~325 Gg/yr. The BC budget calculated in the BS showed that atmospheric deposition and riverine discharge played comparable importance in delivering BC to the BS, and sequestration to bottom sediments was the major BC output pattern, accounting for ~88% of the total input BC. Besides, we attempted to apportion the BC sources in the BS and YS surface sediments using PAHs (organic molecular proxies cogenerated with BC) and BC as an input data to the Positive Matrix Factorization (PMF) receptor model. Results showed that ~83% of the sediment BC was attributed to the combustion of fossil fuels, and the remaining ~17% was from biomass burning. Due to the differences in their production mechanisms and therefore physicochemical properties, the above distinction and quantification would help us better understand their different environmental behaviors in the complex continental shelf

  6. Effect of carbon dioxide and bicarbonate as inorganic carbon sources on growth and adaptation of autohydrogenotrophic denitrifying bacteria

    International Nuclear Information System (INIS)

    Ghafari, Shahin; Hasan, Masitah; Aroua, Mohamed Kheireddine

    2009-01-01

    Acclimation of autohydrogenotrophic denitrifying bacteria using inorganic carbon source (CO 2 and bicarbonate) and hydrogen gas as electron donor was performed in this study. In this regard, activated sludge was used as the seed source and sequencing batch reactor (SBR) technique was applied for accomplishing the acclimatization. Three distinct strategies in feeding of carbon sources were applied: (I) continuous sparging of CO 2 , (II) bicarbonate plus continuous sparging of CO 2 , and (III) only bicarbonate. The pH-reducing nature of CO 2 showed an unfavorable impact on denitrification rate; however bicarbonate resulted in a buffered environment in the mixed liquor and provided a suitable mean to maintain the pH in the desirable range of 7-8.2. As a result, bicarbonate as the only carbon source showed a faster adaptation, while carbon dioxide as the only carbon source as well as a complementary carbon source added to bicarbonate resulted in longer acclimation period. Adapted hydrogenotrophic denitrifying bacteria, using bicarbonate and hydrogen gas in the aforementioned pH range, caused denitrification at a rate of 13.33 mg NO 3 - -N/g MLVSS/h for degrading 20 and 30 mg NO 3 - -N/L and 9.09 mg NO 3 - -N/g MLVSS/h for degrading 50 mg NO 3 - -N/L

  7. Puzzling accretion onto a black hole in the ultraluminous X-ray source M 101 ULX-1.

    Science.gov (United States)

    Liu, Ji-Feng; Bregman, Joel N; Bai, Yu; Justham, Stephen; Crowther, Paul

    2013-11-28

    There are two proposed explanations for ultraluminous X-ray sources (ULXs) with luminosities in excess of 10(39) erg s(-1). They could be intermediate-mass black holes (more than 100-1,000 solar masses, M sun symbol) radiating at sub-maximal (sub-Eddington) rates, as in Galactic black-hole X-ray binaries but with larger, cooler accretion disks. Alternatively, they could be stellar-mass black holes radiating at Eddington or super-Eddington rates. On its discovery, M 101 ULX-1 had a luminosity of 3 × 10(39) erg s(-1) and a supersoft thermal disk spectrum with an exceptionally low temperature--uncomplicated by photons energized by a corona of hot electrons--more consistent with the expected appearance of an accreting intermediate-mass black hole. Here we report optical spectroscopic monitoring of M 101 ULX-1. We confirm the previous suggestion that the system contains a Wolf-Rayet star, and reveal that the orbital period is 8.2 days. The black hole has a minimum mass of 5 M sun symbol, and more probably a mass of 20 M sun symbol-30 M sun symbol, but we argue that it is very unlikely to be an intermediate-mass black hole. Therefore, its exceptionally soft spectra at high Eddington ratios violate the expectations for accretion onto stellar-mass black holes. Accretion must occur from captured stellar wind, which has hitherto been thought to be so inefficient that it could not power an ultraluminous source.

  8. A characterization of Arctic aerosols on the basis of aerosol optical depth and black carbon measurements

    Directory of Open Access Journals (Sweden)

    R. S. Stone

    2014-06-01

    Full Text Available Abstract Aerosols, transported from distant source regions, influence the Arctic surface radiation budget. When deposited on snow and ice, carbonaceous particles can reduce the surface albedo, which accelerates melting, leading to a temperature-albedo feedback that amplifies Arctic warming. Black carbon (BC, in particular, has been implicated as a major warming agent at high latitudes. BC and co-emitted aerosols in the atmosphere, however, attenuate sunlight and radiatively cool the surface. Warming by soot deposition and cooling by atmospheric aerosols are referred to as “darkening” and “dimming” effects, respectively. In this study, climatologies of spectral aerosol optical depth AOD (2001–2011 and Equivalent BC (EBC (1989–2011 from three Arctic observatories and from a number of aircraft campaigns are used to characterize Arctic aerosols. Since the 1980s, concentrations of BC in the Arctic have decreased by more than 50% at ground stations where in situ observations are made. AOD has increased slightly during the past decade, with variations attributed to changing emission inventories and source strengths of natural aerosols, including biomass smoke and volcanic aerosol, further influenced by deposition rates and airflow patterns.

  9. Characterization of atmospheric black carbon and co-pollutants in urban and rural areas of Spain

    Science.gov (United States)

    Becerril-Valle, M.; Coz, E.; Prévôt, A. S. H.; Močnik, G.; Pandis, S. N.; Sánchez de la Campa, A. M.; Alastuey, A.; Díaz, E.; Pérez, R. M.; Artíñano, B.

    2017-11-01

    A one-year black carbon (BC) experimental study was performed at three different locations (urban traffic, urban background, rural) in Spain with different equivalent BC (eBC) source characteristics by means of multi-wavelength Aethalometers. The Aethalometer model was used for the source apportionment study, based on the difference in absorption spectral dependence of emissions from biomass burning (bb) and fossil fuel (ff) combustion. Most studies use a single bb and ff absorption Ångström exponent (AAE) pair (AAEbb and AAEff), however in this work we use a range of AAE values associated with fossil fuel and biomass burning based on the available measurements, which represents more properly all conditions. A sensitivity analysis of the source specific AAE was carried out to determine the most appropriate AAE values, being site dependent and seasonally variable. Here we present a methodology for the determination of the ranges of AAEbb and AAEff by evaluating the correlations between the source apportionment of eBC using the Aethalometer model with four biomass burning tracers measured at the rural site. The best combination was AAEbb = [1.63-1.74] and AAEff = [0.97-1.12]. Mean eBC values (±SD) obtained during the period of study were 3.70 ± 3.73 μg m-3 at the traffic urban site, 2.33 ± 2.96 μg m-3 at the urban background location, and 2.61 ± 5.04 μg m-3 in the rural area. High contributions of eBC to the PM10 mass were found (values up to 21% in winter), but with high eBC/PM10 variability. The hourly mean eBCff and eBCbb concentrations varied from 0 to 51 μg m-3 and from 0 to 50 μg m-3 at the three sites, respectively, exhibiting distinct seasonal and daily patterns. The fossil fuel combustion was the dominant eBC source at the urban sites, while biomass burning dominated during the cold season (88% of eBCbb) in the rural area. Daily PM2.5 and PM10 samples were collected using high-volume air samplers and analyzed for OC and EC. Analysis of biomass

  10. The Toxicological Mechanisms of Environmental Soot (Black Carbon and Carbon Black: Focus on Oxidative Stress and Inflammatory Pathways

    Directory of Open Access Journals (Sweden)

    Rituraj Niranjan

    2017-06-01

    Full Text Available The environmental soot and carbon blacks (CBs cause many diseases in humans, but their underlying mechanisms of toxicity are still poorly understood. Both are formed after the incomplete combustion of hydrocarbons but differ in their constituents and percent carbon contents. For the first time, “Sir Percival Pott” described soot as a carcinogen, which was subsequently confirmed by many others. The existing data suggest three main types of diseases due to soot and CB exposures: cancer, respiratory diseases, and cardiovascular dysfunctions. Experimental models revealed the involvement of oxidative stress, DNA methylation, formation of DNA adducts, and Aryl hydrocarbon receptor activation as the key mechanisms of soot- and CB-induced cancers. Metals including Si, Fe, Mn, Ti, and Co in soot also contribute in the reactive oxygen species (ROS-mediated DNA damage. Mechanistically, ROS-induced DNA damage is further enhanced by eosinophils and neutrophils via halide (Cl− and Br− dependent DNA adducts formation. The activation of pulmonary dendritic cells, T helper type 2 cells, and mast cells is crucial mediators in the pathology of soot- or CB-induced respiratory disease. Polyunsaturated fatty acids (PUFAs were also found to modulate T cells functions in respiratory diseases. Particularly, telomerase reverse transcriptase was found to play the critical role in soot- and CB-induced cardiovascular dysfunctions. In this review, we propose integrated mechanisms of soot- and CB-induced toxicity emphasizing the role of inflammatory mediators and oxidative stress. We also suggest use of antioxidants and PUFAs as protective strategies against soot- and CB-induced disorders.

  11. Carbon black nanoparticles film electrode prepared by using substrate-induced deposition approach

    Energy Technology Data Exchange (ETDEWEB)

    Svegl, Irena Grabec; Bele, Marjan [National Institute of Chemistry, P.O. Box 660, SI-1001 Ljubljana (Slovenia); Ogorevc, Bozidar [National Institute of Chemistry, P.O. Box 660, SI-1001 Ljubljana (Slovenia)], E-mail: bogorevc@ki.si

    2008-11-03

    A new type of carbon film electrode, composed of a thin layer of tightly packed carbon black (CB) nanoparticles deposited onto a gelatin-covered indium tin oxide/glass support using the surface-induced deposition (SID) approach, is presented. Some parameters of the novel SID method were optimized and the surface image and functionalization of the investigated carbon black film electrode (CBFE) was inspected by employing scanning electron microscopy and infrared spectroscopy. A cyclic voltammetry (CV) study was conducted in which the electron-transfer kinetics and CBFE interfacial characteristics were evaluated employing several selected reference redox systems, such as [Ru(NH{sub 3}){sub 6}]{sup 3+/2+}, [Fe(CN){sub 6}]{sup 3-/4-} and Fe{sup 3+/2+} in aqueous, and ferrocene/ferrocenium in acetonitrile media. CV recordings were also performed in order to compare the electrochemical behavior of the CBFE with that of some well-known and established bare carbon-based electrodes. In order to confirm the validity of the CB film preparation method, the electroanalytical performance of the proposed CBFE was examined by carrying out linear sweep voltammetry of ascorbic acid (AA), anodic stripping square-wave voltammetry of Cu(II) in acidic medium, and amperometric measurements of hydrogen peroxide under flow injection conditions. The sensing characteristics of the novel carbon film electrode, demonstrated in this preliminary study, comprise: (i) a wide working potential window ranging from +1.0 to -1.3 V (depending on the solution pH), (ii) a wide applicable pH range (at least from 2 to 12), (iii) low voltammetric background (<5 {mu}A cm{sup -2}), (iv) a satisfactory linear voltammetric and amperometric response (r{sup 2} > 0.99) to various analytes, (v) good reproducibility (for example, r.s.d. of 2% in amperometric detection of H{sub 2}O{sub 2} and r.s.d. of 8.5% for electrode-to-electrode CV runs), and (vi) stable and fast current response (at least 100 CV runs with

  12. Evaluation of Methods for the Determination of Black Carbon Emissions from an Aircraft Gas Turbine Engine

    Science.gov (United States)

    The emissions from aircraft gas turbine engines consist of nanometer size black carbon (BC) particles plus gas-phase sulfur and organic compounds which undergo gas-to-particle conversion downstream of the engine as the plume cools and dilutes. In this study, four BC measurement ...

  13. Corrosion protection and delamination mechanism of epoxy/carbon black nanocomposite coating on AA2024-T3

    NARCIS (Netherlands)

    Foyet, A.; Wu, T.H.; Kodentsov, A.; Ven, van der L.G.J.; With, de G.; Benthem, van R.A.T.M.

    2013-01-01

    The barrier property of a nanocomposite epoxy coating containing 1 or 1.25 vol% of carbon black (CB) applied on AA2024-T3 was investigated by using electrochemical impedance spectroscopy. Micro-electrochemical impedance spectroscopy and optical microscopy were also used to investigate the

  14. Combining charcoal and elemental black carbon analysis in sedimentary archives: Implications for past fire regimes, the pyrogenic carbon cycle, and the human-climate interactions

    Science.gov (United States)

    Thevenon, Florian; Williamson, David; Bard, Edouard; Anselmetti, Flavio S.; Beaufort, Luc; Cachier, Hélène

    2010-07-01

    This paper addresses the quantification of combustion-derived products in oceanic and continental sediments by optical and chemical approaches, and the interest of combining such methods for reconstructing past biomass burning activity and the pyrogenic carbon cycle. In such context, the dark particles > 0.2 µm 2 remaining after the partial digestion of organic matter are optically counted by automated image analysis and defined as charcoal, while the elemental carbon remaining after thermal and chemical oxidative treatments is quantified as black carbon (BC). The obtained pyrogenic carbon records from three sediment core-based case studies, (i) the Late Pleistocene equatorial Pacific Ocean, (ii) the mid-Holocene European Lake Lucerne, and (iii) the Late Holocene African Lake Masoko, are interpreted as proxy records of regional transportation mechanisms and biomass burning activities. The results show that the burial of dark carbon-rich particles in the 360 kyr-long record from the west equatorial Pacific is controlled by the combination of sea-level changes and low-latitude atmospheric circulation patterns (summer monsoon dynamics). However, the three fold increases in charcoal and BC sediment influxes between 53-43 and 12-10 kyr BP suggest that major shifts in fire activity occur synchronously with human colonization in the Indo/Pacific region. The coarse charcoal distribution from a 7.2 kyr record from Lake Lucerne in Switzerland closely matches the regional timing of major technical, land-use, and socio-economic changes during the Neolithic (between ca. 5.7 and 5.2 kyr BP and 4.9-4.5 kyr BP), the Bronze and Iron Ages (at ca. 3.3 and 2.4 kyr BP, respectively), and the industrialization (after AD 1838), pointing to the key impact of human activities on the sources, transportation processes and reservoirs of refractory carbon during the Holocene. In the tropical Masoko maar lake in Tanzania, where charcoal and BC records are highly sensitive to the local climate

  15. Dynamic molecular structure of plant biomass-derived black carbon (biochar)

    Energy Technology Data Exchange (ETDEWEB)

    Keiluweit, M.; Nico, P.S.; Johnson, M.G.; Kleber, M.

    2009-11-15

    Char black carbon (BC), the solid residue of incomplete combustion, is continuously being added to soils and sediments due to natural vegetation fires, anthropogenic pollution, and new strategies for carbon sequestration ('biochar'). Here we present a molecular-level assessment of the physical organization and chemical complexity of biomass-derived chars and, specifically, that of aromatic carbon in char structures. BET-N{sub 2} surface area, X-ray diffraction (XRD), synchrotron-based Near-edge X-ray Absorption Fine Structure (NEXAFS), and Fourier transform infrared (FT-IR) spectroscopy are used to show how two plant materials (wood and grass) undergo analogous, but quantitatively different physical-chemical transitions as charring temperature increases from 100 to 700 C. These changes suggest the existence of four distinct categories of char consisting of a unique mixture of chemical phases and physical states: (i) in transition chars the crystalline character of the precursor materials is preserved, (ii) in amorphous chars the heat-altered molecules and incipient aromatic polycondensates are randomly mixed, (iii) composite chars consist of poorly ordered graphene stacks embedded in amorphous phases, and (iv) turbostratic chars are dominated by disordered graphitic crystallites. The molecular variations among the different char categories translate into differences in their ability to persist in the environment and function as environmental sorbents.

  16. Non classical sources of uranium and their extraction techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ziegler, V [CEA, 75 - Paris (France)

    1978-11-01

    Non classical uranium sources are reviewed: phosphates, sea water, porphyric copper tailings, minerals allowing in-situ lixiviation, black carbon shales, coals and lignites, granitic rocks. An economical study has shown which sources could be really operative (phosphates seem the most attractive). The situation of uranium supplies does not seem to be actually modified by exploitation of these resources.

  17. From binary black hole simulation to triple black hole simulation

    International Nuclear Information System (INIS)

    Bai Shan; Cao Zhoujian; Han, Wen-Biao; Lin, Chun-Yu; Yo, Hwei-Jang; Yu, Jui-Ping

    2011-01-01

    Black hole systems are among the most promising sources for a gravitational wave detection project. Now, China is planning to construct a space-based laser interferometric detector as a follow-on mission of LISA in the near future. Aiming to provide some theoretical support to this detection project on the numerical relativity side, we focus on black hole systems simulation in this work. Considering the globular galaxy, multiple black hole systems also likely to exist in our universe and play a role as a source for the gravitational wave detector we are considering. We will give a progress report in this paper on our black hole system simulation. More specifically, we will present triple black hole simulation together with binary black hole simulation. On triple black hole simulations, one novel perturbational method is proposed.

  18. Characterizing the Vertical and Spatial Distribution of Black Carbon on the North Slope of Alaska

    Science.gov (United States)

    Sedlacek, A. J., III; Feng, Y.; Biraud, S.; Springston, S. R.

    2016-12-01

    The Polar Regions are recognized for their pronounced sensitivity to changes in radiative forcing. Indeed, the Cryosphere is often referred to as the `canary in the coalmine' for climate change in the popular literature. It is this sensitivity that provides both motivation and need for targeted measurement campaigns to test the behavior and predictive capabilities of current climate models to so as to improve our understanding of which factors are most important in Arctic climate change. One class of under measured radiative forcing agents in the Polar Region is the absorbing aerosol - black carbon and brown carbon. In particular, the paucity of vertical profile information of BC is partly responsible for the difficulty of reducing uncertainty in model assessment of aerosol radiative impact at high latitudes. During the summer of 2015, a Single-Particle Soot Photometer (SP2) was deployed aboard the DOE Gultstream-1 (G-1) aircraft to measure refractory BC (rBC) concentrations as part of the DOE-sponsored ACME-V (ARM Airborne Carbon Measurements) campaign. This campaign was conducted from June through to mid-September along the North Slope of Alaska and was punctuated by vertical profiling over 5 sites (Atquasuk, Barrow, Ivotuk, Oliktok, and Toolik). In addition, measurement of CO, CO2 and CH4 were also taken to provide information on the spatial and seasonal differences in GHG sources and how these sources correlate with BC. Comparisons between observations and a global climate model (CAM5) simulations will be shown along with a discussion on the ability of the model to capture observed monthly mean profiles of BC and stratified aerosol layers. Additionally, the capability of the SP2 to partition rBC-containing particles into nascent or aged allows an evaluation of how well the CAM5 model captures long distant transported aged carbonaceous aerosols. Finally model sensitivity studies will be presented that investigated the relative importance of the different

  19. Top-down estimates of biomass burning emissions of black carbon in the western United States

    Science.gov (United States)

    Y. H. Mao; Q. B. Li; D. Chen; L. Zhang; W. -M. Hao; K.-N. Liou

    2014-01-01

    We estimate biomass burning and anthropogenic emissions of black carbon (BC) in the western US for May-October 2006 by inverting surface BC concentrations from the Interagency Monitoring of PROtected Visual Environment (IMPROVE) network using a global chemical transport model. We first use active fire counts from the Moderate Resolution Imaging Spectroradiometer (MODIS...

  20. Stable carbon isotope analysis reveals widespread drought stress in boreal black spruce forests.

    Science.gov (United States)

    Walker, Xanthe J; Mack, Michelle C; Johnstone, Jill F

    2015-08-01

    Unprecedented rates of climate warming over the past century have resulted in increased forest stress and mortality worldwide. Decreased tree growth in association with increasing temperatures is generally accepted as a signal of temperature-induced drought stress. However, variations in tree growth alone do not reveal the physiological mechanisms behind recent changes in tree growth. Examining stable carbon isotope composition of tree rings in addition to tree growth can provide a secondary line of evidence for physiological drought stress. In this study, we examined patterns of black spruce growth and carbon isotopic composition in tree rings in response to climate warming and drying in the boreal forest of interior Alaska. We examined trees at three nested scales: landscape, toposequence, and a subsample of trees within the toposequence. At each scale, we studied the potential effects of differences in microclimate and moisture availability by sampling on northern and southern aspects. We found that black spruce radial growth responded negatively to monthly metrics of temperature at all examined scales, and we examined ∆(13)C responses on a subsample of trees as representative of the wider region. The negative ∆(13)C responses to temperature reveal that black spruce trees are experiencing moisture stress on both northern and southern aspects. Contrary to our expectations, ∆(13)C from trees on the northern aspect exhibited the strongest drought signal. Our results highlight the prominence of drought stress in the boreal forest of interior Alaska. We conclude that if temperatures continue to warm, we can expect drought-induced productivity declines across large regions of the boreal forest, even for trees located in cool and moist landscape positions. © 2015 John Wiley & Sons Ltd.

  1. Influence of the Synthesis Method for Pt Catalysts Supported on Highly Mesoporous Carbon Xerogel and Vulcan Carbon Black on the Electro-Oxidation of Methanol

    Directory of Open Access Journals (Sweden)

    Cinthia Alegre

    2015-03-01

    Full Text Available Platinum catalysts supported on carbon xerogel and carbon black (Vulcan were synthesized with the aim of investigating the influence of the characteristics of the support on the electrochemical performance of the catalysts. Three synthesis methods were compared: an impregnation method with two different reducing agents, sodium borohydride and formic acid, and a microemulsion method, in order to study the effect of the synthesis method on the physico-chemical properties of the catalysts. X-ray diffraction and transmission electron microscopy were applied. Cyclic voltammetry and chronoamperometry were used for studying carbon monoxide and methanol oxidation. Catalysts supported on carbon xerogel presented higher catalytic activities towards CO and CH3OH oxidation than catalysts supported on Vulcan. The higher mesoporosity of carbon xerogel was responsible for the favored diffusion of reagents towards catalytic centers.

  2. Assessing the combined influence of TOC and black carbon in soil–air partitioning of PBDEs and DPs from the Indus River Basin, Pakistan

    International Nuclear Information System (INIS)

    Ali, Usman; Mahmood, Adeel; Syed, Jabir Hussain; Li, Jun; Zhang, Gan; Katsoyiannis, Athanasios; Jones, Kevin C.; Malik, Riffat Naseem

    2015-01-01

    Levels of polybrominated diphenyl ethers (PBDEs) and dechlorane plus (DPs) were investigated in the Indus River Basin from Pakistan. Concentrations of ∑PBDEs and ∑DPs were ranged between 0.05 and 2.38 and 0.002–0.53 ng g −1 in the surface soils while 1.43–22.1 and 0.19–7.59 pg m −3 in the passive air samples, respectively. Black carbon (f BC ) and total organic carbon (f TOC ) fractions were also measured and ranged between 0.73 and 1.75 and 0.04–0.2%, respectively. The statistical analysis revealed strong influence of f BC than f TOC on the distribution of PBDEs and DPs in the Indus River Basin soils. BDE's congener profile suggested the input of penta–bromodiphenylether (DE-71) commercial formulation in the study area. Soil–air partitioning of PBDEs were investigated by employing octanol-air partition coefficients (K OA ) and black carbon-air partition coefficients (K BC−A ). The results of both models suggested the combined influence of total organic carbon (absorption) and black carbon (adsorption) in the studied area. - Highlights: • Model based calculations of black carbon-air partition coefficients for PBDEs. • Soil and air levels of PBDEs and DPs reported first time for ecologically important sites of the Indus River Basin, Pakistan. • Both, f BC and f TOC showed combined influence on soil–air partitioning of PBDEs in the Indus River Basin, Pakistan. - BC and TOC showed combined influence on soil–air partitioning of POPs i-e., PBDEs in the Indus River Basin, Pakistan

  3. Inferring absorbing organic carbon content from AERONET data

    Science.gov (United States)

    Arola, A.; Schuster, G.; Myhre, G.; Kazadzis, S.; Dey, S.; Tripathi, S. N.

    2011-01-01

    Black carbon, light-absorbing organic carbon (often called "brown carbon") and mineral dust are the major light-absorbing aerosols. Currently the sources and formation of brown carbon aerosol in particular are not well understood. In this study we estimated the amount of light-absorbing organic carbon and black carbon from AERONET measurements. We find that the columnar absorbing organic carbon (brown carbon) levels in biomass burning regions of South America and Africa are relatively high (about 15-20 mg m-2 during biomass burning season), while the concentrations are significantly lower in urban areas in US and Europe. However, we estimated significant absorbing organic carbon amounts from the data of megacities of newly industrialized countries, particularly in India and China, showing also clear seasonality with peak values up to 30-35 mg m-2 during the coldest season, likely caused by the coal and biofuel burning used for heating. We also compared our retrievals with the modeled organic carbon by the global Oslo CTM for several sites. Model values are higher in biomass burning regions than AERONET-based retrievals, while the opposite is true in urban areas in India and China.

  4. Effect of carbon dioxide and bicarbonate as inorganic carbon sources on growth and adaptation of autohydrogenotrophic denitrifying bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Ghafari, Shahin; Hasan, Masitah [Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Aroua, Mohamed Kheireddine [Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia)], E-mail: mk_aroua@um.edu.my

    2009-03-15

    Acclimation of autohydrogenotrophic denitrifying bacteria using inorganic carbon source (CO{sub 2} and bicarbonate) and hydrogen gas as electron donor was performed in this study. In this regard, activated sludge was used as the seed source and sequencing batch reactor (SBR) technique was applied for accomplishing the acclimatization. Three distinct strategies in feeding of carbon sources were applied: (I) continuous sparging of CO{sub 2}, (II) bicarbonate plus continuous sparging of CO{sub 2}, and (III) only bicarbonate. The pH-reducing nature of CO{sub 2} showed an unfavorable impact on denitrification rate; however bicarbonate resulted in a buffered environment in the mixed liquor and provided a suitable mean to maintain the pH in the desirable range of 7-8.2. As a result, bicarbonate as the only carbon source showed a faster adaptation, while carbon dioxide as the only carbon source as well as a complementary carbon source added to bicarbonate resulted in longer acclimation period. Adapted hydrogenotrophic denitrifying bacteria, using bicarbonate and hydrogen gas in the aforementioned pH range, caused denitrification at a rate of 13.33 mg NO{sub 3}{sup -}-N/g MLVSS/h for degrading 20 and 30 mg NO{sub 3}{sup -}-N/L and 9.09 mg NO{sub 3}{sup -}-N/g MLVSS/h for degrading 50 mg NO{sub 3}{sup -}-N/L.

  5. Black carbon, organic carbon, and co-pollutant emissions and energy efficiency from artisanal brick production in Mexico

    Science.gov (United States)

    Zavala, Miguel; Molina, Luisa T.; Maiz, Pablo; Monsivais, Israel; Chow, Judith C.; Watson, John G.; Munguia, Jose Luis; Cardenas, Beatriz; Fortner, Edward C.; Herndon, Scott C.; Roscioli, Joseph R.; Kolb, Charles E.; Knighton, Walter B.

    2018-04-01

    In many parts of the developing world and economies in transition, small-scale traditional brick kilns are a notorious source of urban air pollution. Many are both energy inefficient and burn highly polluting fuels that emit significant levels of black carbon (BC), organic carbon (OC) and other atmospheric pollutants into local communities, resulting in severe health and environmental impacts. However, only a very limited number of studies are available on the emission characteristics of brick kilns; thus, there is a need to characterize their gaseous and particulate matter (PM) emission factors to better assess their overall contribution to emissions inventories and to quantify their ecological, human health, and climate impacts. In this study, the fuel-, energy-, and brick-based emissions factors and time-based emission ratios of BC, OC, inorganic PM components, CO, SO2, CH4, NOx, and selected volatile organic compounds (VOCs) from three artisanal brick kilns with different designs in Mexico were quantified using the tracer ratio sampling technique. Simultaneous measurements of PM components, CO, and CO2 were also obtained using a sampling probe technique. Additional measurements included the internal temperature of the brick kilns, mechanical resistance of bricks produced, and characteristics of fuels employed. Average fuel-based BC emission factors ranged from 0.15 to 0.58 g (kg fuel)-1, whereas BC/OC mass ratios ranged from 0.9 to 5.2, depending on the kiln type. The results show that both techniques capture similar temporal profiles of the brick kiln emissions and produce comparable emission factors. A more integrated inter-comparison of the brick kilns' performances was obtained by simultaneously assessing emissions factors, energy efficiency, fuel consumption, and the quality of the bricks produced.

  6. The Nordic Seas carbon budget: Sources, sinks, and uncertainties

    OpenAIRE

    Jeansson, Emil; Olsen, Are; Eldevik, Tor; Skjelvan, Ingunn; Omar, Abdirahman M.; Lauvset, Siv K.; Nilsen, Jan Even Ø.; Bellerby, Richard G. J; Johannessen, Truls; Falck, Eva

    2011-01-01

    A carbon budget for the Nordic Seas is derived by combining recent inorganic carbon data from the CARINA database with relevant volume transports. Values of organic carbon in the Nordic Seas' water masses, the amount of carbon input from river runoff, and the removal through sediment burial are taken from the literature. The largest source of carbon to the Nordic Seas is the Atlantic Water that enters the area across the Greenland-Scotland Ridge; this is in particular true for the anthropogen...

  7. Stable isotope and trace element studies of black bear hair, Big Bend ecosystem, Texas and Mexico

    Science.gov (United States)

    Shanks, W.C. Pat; Hellgren, Eric C.; Stricker, Craig A.; Gemery-Hill, Pamela A.; Onorato, David P.

    2008-01-01

    Hair from black bears (Ursus americanus), collected from four areas in the Big Bend ecosystem, has been analyzed for stable isotopes of carbon, nitrogen, and sulfur to determine major food sources and for trace metals to infer possible effects of environmental contaminants. Results indicate that black bears are largely vegetarian, feeding on desert plants, nuts, and berries. Mercury concentrations in bear hair are below safe level standards (

  8. Black carbon emissions from diesel sources in Russia. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kholod, Nazar [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Evans, Meredydd [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-08-31

    This report presents a detailed inventory of Russian BC emissions from diesel sources. Drawing on a complete Russian vehicle registry with detailed information about vehicle types and emission standards, this report analyzes BC emissions from diesel on-road vehicles. On-road diesel vehicles emitted 21 Gg of BC in 2014: heavy-duty trucks account for 60% of the on-road BC emissions, while cars represent only 5% (light commercial vehicles and buses account for the remainder). Using Russian activity data and fuel-based emission factors, the report also presents BC emissions from diesel locomotives and ships, off-road engines in industry, construction and agriculture, and generators. The total emissions from diesel sources in Russia are estimated to be 49 Gg of BC in 2014.

  9. Influence of updating global emission inventory of black carbon on evaluation of the climate and health impact

    Science.gov (United States)

    Wang, Rong; Tao, Shu; Balkanski, Yves; Ciais, Philippe

    2013-04-01

    Black carbon (BC) is an air component of particular concern in terms of air quality and climate change. Black carbon emissions are often estimated based on the fuel data and emission factors. However, large variations in emission factors reported in the literature have led to a high uncertainty in previous inventories. Here, we develop a new global 0.1°×0.1° BC emission inventory for 2007 with full uncertainty analysis based on updated source and emission factor databases. Two versions of LMDz-OR-INCA models, named as INCA and INCA-zA, are run to evaluate the new emission inventory. INCA is built up based on a regular grid system with a resolution of 1.27° in latitude and 2.50° in longitude, while INCA-zA is specially zoomed to 0.51°×0.66° (latitude×longitude) in Asia. By checking against field observations, we compare our inventory with ACCMIP, which is used by IPCC in the 5th assessment report, and also evaluate the influence of model resolutions. With the newly calculated BC air concentrations and the nested model, we estimate the direct radiative forcing of BC and the premature death and mortality rate induced by BC exposure with Asia emphasized. Global BC direct radiative forcing at TOA is estimated to be 0.41 W/m2 (0.2 - 0.8 as inter-quartile range), which is 17% higher than that derived from the inventory adopted by IPCC-AR5 (0.34 W/m2). The estimated premature deaths induced by inhalation exposure to anthropogenic BC (0.36 million in 2007) and the percentage of high risk population are higher than those previously estimated. Ninety percents of the global total anthropogenic PD occur in Asia with 0.18 and 0.08 million deaths in China and India, respectively.

  10. Effects of occupational exposure to carbon black on peripheral white blood cell counts and lymphocyte subsets

    NARCIS (Netherlands)

    Dai, Yufei; Niu, Yong; Duan, Huawei; Bassig, Bryan A; Ye, Meng; Zhang, Xiao; Meng, Tao; Bin, Ping; Jia, Xiaowei; Shen, Meili; Zhang, Rong; Hu, Wei; Yang, Xiaofa; Vermeulen, Roel; Silverman, Debra; Rothman, Nathaniel; Lan, Qing; Yu, Shanfa; Zheng, Yuxin

    2016-01-01

    The International Agency for Research on Cancer has classified carbon black (CB) as a possible (Group 2B) human carcinogen. Given that most CB manufacturing processes result in the emission of various types of chemicals, it is uncertain if the adverse health effects that have been observed in

  11. Pathogenic Yet Environmentally Friendly? Black Fungal Candidates for Bioremediation of Pollutants : Geomicrobiology Journal

    NARCIS (Netherlands)

    Blasi, B.; Poyntner, C.; Rudavsky, T.; Prenafeta-Boldu, F. X.; De Hoog, S.; Tafer, H.; Sterflinger, K.

    2016-01-01

    A collection of 163 strains of black yeast-like fungi from the CBS Fungal Biodiversity Center (Utrecht, The Netherlands), has been screened for the ability to grow on hexadecane, toluene and polychlorinated biphenyl 126 (PCB126) as the sole carbon and energy source. These compounds were chosen as

  12. High Voltage Surface Degradation on Carbon Blacks in Lithium Ion Batteries

    DEFF Research Database (Denmark)

    Younesi, Reza

    In order to increase the power density of Li-ion batteries, much research is focused on developing cathode materials that can operate at high voltages above 4.5 V with a high capacity, high cycling stability, and rate capability. However, at high voltages all the components of positive electrodes...... including carbon black (CB) additives have a potential risk of degradation. Though the weight percentage of CB in commercial batteries is generally very small, the volumetric amount and thus the surface area of CB compose a rather large part of a cathode due to its small particle size (≈ 50 nm) and high...

  13. Black carbon at a coastal Antarctic station (Syowa Station: seasonal variation and transport processes

    Directory of Open Access Journals (Sweden)

    Keiichiro Hara

    2010-12-01

    Full Text Available Measurement of atmospheric black carbon (BC was carried out at Syowa Station Antarctica (69゜00′S, 39゜35′E from February 2004 until January 2007. The BC concentration at Syowa Station ranged from below detection to 176 ng m^. Higher BC concentrations were observed frequently from April until October. Increase of BC concentration may be associated with poleward flow due to the approach of a cyclone and or blocking event during winter-spring. The BC-rich air masses traveled through the lower troposphere from the Atlantic and Indian Oceans to Syowa (Antarctic coast. During the summer (November-February, the BC concentration showed a diurnal variation together with surface wind speed and increased in the presence of katabatic wind from the Antarctic continent. Considering the low BC source strength over the Antarctic continent, the higher BC concentration in the continental air (katabatic wind might be caused by long range transport of BC via the free troposphere from mid- and low- latitudes. The seasonal variation of BC at Syowa Station had a maximum in July-September, while at the other coastal stations (Halley, Neumayer, and Ferraz and a continental station (Amundsen-Scott, the maximum occurred in October. This difference may result from different transport pathways, significant contribution of source regions and scavenging of BC by precipitation during the transport from the source regions. During the austral summer, long-range transport of BC via the free troposphere is likely to make an important contribution to the ambient BC concentration along the Antarctic coasts.

  14. Geochemical characteristics of Holocene laminated sapropel (unit II) and underlying lacustrine unit III in the Black Sea

    Science.gov (United States)

    Dean, Walter E.; Arthur, Michael A.

    2011-01-01

    eg 1 of the 1988 R/V Knorr expeditions to the Black Sea recovered 90 gravity and box cores. The longest recovery by gravity cores was about 3 meters, with an average of about 2.5 meters, recovering all of the Holocene and upper Pleistocene sections in the Black Sea. During the latest Pleistocene glaciation, sea level dropped below the 35-meters-deep Bosporus outlet sill of the Black Sea. Therefore throughout most of its history the Black Sea was a lake, and most of its sediments are lacustrine. The oldest sediments recovered (older than 8,000 calendar years) consist of massive to coarsely banded lacustrine calcareous clay designated as lithologic Unit III, generally containing less than 1 percent organic carbon (OC). The base of overlying Unit II marks the first incursion of Mediterranean seawater into the Black Sea, and the onset of bottom-water anoxia about 7,900 calendar years. Unit II contains as much as 15 percent OC in cores from the deepest part of the Black Sea (2,200 meters). The calcium carbonate (CaCO3) remains of the coccolith Emiliania huxleyi form the distinctive white laminae of overlying Unit I. The composition of Unit III and Unit II sediments are quite different, reflecting different terrigenous clastic sources and increased contributions from hydrogenous and biogenic components in anoxic Unit II sapropel. In Unit II, positive covariance between OC and three trace elements commonly concentrated in OC-rich sediments where sulfate reduction has occurred (molybdenum, nickel, and vanadium) and a nutrient (phosphorus) suggest a large marine source for these elements although nickel and vanadium also have a large terrigenous clastic source. The marine sources may be biogenic or hydrogenous. A large biogenic source is also suggested for copper and cobalt. Because abundant pyrite forms in the water column and sediments of the Black Sea, we expected to find a large hydrogenous iron component, but a strong covariance of iron with aluminum suggests that the

  15. Density separation of combustion-derived soot and petrogenic graphitic black carbon: Quantification and isotopic characterization

    International Nuclear Information System (INIS)

    Veilleux, M-H; Gelinas, Y; Dickens, A F; Brandes, J

    2009-01-01

    The black carbon continuum is composed of a series of carbon-rich components derived from combustion or metamorphism and characterized by contrasting environmental behavior and susceptibility to oxidation. In this work, we present a micro-scale density fractionation method that allows isolating the small quantities of soot-like and graphitic material usually found in natural samples. Organic carbon and δ 13 C mass balance calculations were used to quantify the relative contributions of the two fractions to thermally-stable organic matter from a series of aquatic sediments. Varying proportions of soot-like and graphitic material were found in these samples, with large variations in δ 13 C signatures suggesting important differences in their origin and/or dynamics in the environment.

  16. Utilization of carbon and nitrogen sources by Streptomyces ...

    African Journals Online (AJOL)

    We tested a number of carbon and nitrogen compounds for their effect on the production of an antibacterial antibiotic by Streptomyces kananmyceticus M27. Dextrose was found to be the most suitable carbon source, though maltose, sucrose, and soluble starch gave moderate yields. (NH4)H2PO4 and yeast extract were ...

  17. Emission factors of black carbon and co-pollutants from diesel vehicles in Mexico City

    Science.gov (United States)

    Zavala, Miguel; Molina, Luisa T.; Yacovitch, Tara I.; Fortner, Edward C.; Roscioli, Joseph R.; Floerchinger, Cody; Herndon, Scott C.; Kolb, Charles E.; Knighton, Walter B.; Paramo, Victor Hugo; Zirath, Sergio; Mejía, José Antonio; Jazcilevich, Aron

    2017-12-01

    Diesel-powered vehicles are intensively used in urban areas for transporting goods and people but can substantially contribute to high emissions of black carbon (BC), organic carbon (OC), and other gaseous pollutants. Strategies aimed at controlling mobile emissions sources thus have the potential to improve air quality and help mitigate the impacts of air pollutants on climate, ecosystems, and human health. However, in developing countries there are limited data on the BC and OC emission characteristics of diesel-powered vehicles, and thus there are large uncertainties in the estimation of the emission contributions from these sources. We measured BC, OC, and other inorganic components of fine particulate matter (PM), as well as carbon monoxide (CO), nitrogen oxides (NOx), sulfur dioxide (SO2), ethane, acetylene, benzene, toluene, and C2-benzenes under real-world driving conditions for 20 diesel-powered vehicles encompassing multiple emission level technologies in Mexico City with the chasing technique using the Aerodyne mobile laboratory. Average BC emission factors ranged from 0.41-2.48 g kg-1 of fuel depending on vehicle type. The vehicles were also simultaneously measured using the cross-road remote sensing technique to obtain the emission factors of nitrogen oxide (NO), CO, total hydrocarbons, and fine PM, thus allowing for the intercomparison of the results from the two techniques. There is overall good agreement between the two techniques and both can identify high and low emitters, but substantial differences were found in some of the vehicles, probably due to the ability of the chasing technique to capture a larger diversity of driving conditions in comparison to the remote sensing technique. A comparison of the results with the US EPA MOVES2014b model showed that the model underestimates CO, OC, and selected VOC species, whereas there is better agreement for NOx and BC. Larger OC / BC ratios were found in comparison to ratios measured in California using

  18. Emission factors of black carbon and co-pollutants from diesel vehicles in Mexico City

    Directory of Open Access Journals (Sweden)

    M. Zavala

    2017-12-01

    Full Text Available Diesel-powered vehicles are intensively used in urban areas for transporting goods and people but can substantially contribute to high emissions of black carbon (BC, organic carbon (OC, and other gaseous pollutants. Strategies aimed at controlling mobile emissions sources thus have the potential to improve air quality and help mitigate the impacts of air pollutants on climate, ecosystems, and human health. However, in developing countries there are limited data on the BC and OC emission characteristics of diesel-powered vehicles, and thus there are large uncertainties in the estimation of the emission contributions from these sources. We measured BC, OC, and other inorganic components of fine particulate matter (PM, as well as carbon monoxide (CO, nitrogen oxides (NOx, sulfur dioxide (SO2, ethane, acetylene, benzene, toluene, and C2-benzenes under real-world driving conditions for 20 diesel-powered vehicles encompassing multiple emission level technologies in Mexico City with the chasing technique using the Aerodyne mobile laboratory. Average BC emission factors ranged from 0.41–2.48 g kg−1 of fuel depending on vehicle type. The vehicles were also simultaneously measured using the cross-road remote sensing technique to obtain the emission factors of nitrogen oxide (NO, CO, total hydrocarbons, and fine PM, thus allowing for the intercomparison of the results from the two techniques. There is overall good agreement between the two techniques and both can identify high and low emitters, but substantial differences were found in some of the vehicles, probably due to the ability of the chasing technique to capture a larger diversity of driving conditions in comparison to the remote sensing technique. A comparison of the results with the US EPA MOVES2014b model showed that the model underestimates CO, OC, and selected VOC species, whereas there is better agreement for NOx and BC. Larger OC / BC ratios were found in comparison to ratios

  19. Solid state double layer capacitor based on a polyether polymer electrolyte blend and nanostructured carbon black electrode composites

    Energy Technology Data Exchange (ETDEWEB)

    Lavall, Rodrigo L.; Borges, Raquel S.; Calado, Hallen D.R.; Welter, Cezar; Trigueiro, Joao P.C.; Silva, Glaura G. [Departamento de Quimica, Instituto de Ciencias Exatas, Universidade Federal de Minas Gerais, CEP 31270-901, Belo Horizonte (Brazil); Rieumont, Jacques [Departamento de Quimica, Instituto de Ciencias Exatas, Universidade Federal de Minas Gerais, CEP 31270-901, Belo Horizonte (Brazil); Facultad de Quimica, Universidad de La Habana, Habana 10400 (Cuba); Neves, Bernardo R.A. [Departamento de Fisica, Instituto de Ciencias Exatas, Universidade Federal de Minas Gerais, CEP 31270-901, Belo Horizonte (Brazil)

    2008-03-01

    An all solid double layer capacitor was assembled by using poly(ethylene oxide)/poly(propylene glycol)-b-poly(ethylene glycol)-b-poly(propylene glycol)-bis(2-aminopropyl ether) blend (PEO-NPPP) and LiClO{sub 4} as polymer electrolyte layer and PEO-NPPP-carbon black (CB) as electrode film. High molecular weight PEO and the block copolymer NPPP with molecular mass of 2000 Da were employed, which means that the design is safe from the point of view of solvent or plasticizer leakage and thus, a separator is not necessary. Highly conductive with large surface area nanostructured carbon black was dispersed in the polymer blend to produce the electrode composite. The electrolyte and electrode multilayers prepared by spray were studied by differential scanning calorimetry, atomic force microscopy (AFM) and impedance spectroscopy. The ionic conductivity as a function of temperature was fitted with the Williams-Landel-Ferry equation, which indicates a conductivity mechanism typical of solid polymer electrolyte. AFM images of the nanocomposite electrode showed carbon black particles of approximately 60 nm in size well distributed in a semicrystalline and porous polymer blend coating. The solid double layer capacitor with 10 wt.% CB was designed with final thickness of approximately 130 {mu}m and delivered a capacitance of 17 F g{sup -1} with a cyclability of more than 1000 cycles. These characteristics make possible the construction of a miniature device in complete solid state which will avoid electrolyte leakage and present a performance superior to other similar electric double layer capacitors (EDLCs) presented in literature, as assessed in specific capacitance by total carbon mass. (author)

  20. Chemical Composition of the Graphitic Black Carbon Fraction in Riverine and Marine Sediments at Submicron Scales using Carbon X-ray Spectromicroscopy

    International Nuclear Information System (INIS)

    Haberstroh, P.; Brandes, J.; Gelinas, Y.; Dickens, A.; Wirick, S.; Cody, G.

    2006-01-01

    The chemical composition of the graphitic black carbon (GBC) fraction of marine organic matter was explored in several marine and freshwater sedimentary environments along the west coast of North America and the Pacific Ocean. Analysis by carbon x-ray absorption near edge structure (C-XANES) spectroscopy and scanning transmission x-ray microscopy (STXM) show the GBC-fraction of Stillaguamish River surface sediments to be dominated by more highly-ordered and impure forms of graphite, together forming about 80% of the GBC, with a smaller percent of an aliphatic carbon component. Eel River Margin surface sediments had very little highly-ordered graphite, and were instead dominated by amorphous carbon and to a lesser extent, impure graphite. However, the GBC of surface sediments from the Washington State Slope and the Mexico Margin were composed almost solely of amorphous carbon. Pre-anthropogenic, highly-oxidized deep-sea sediments from the open Equatorial Pacific Ocean contained over half their GBC in different forms of graphite as well as highly-aliphatic carbon, low aromatic/highly-acidic aliphatic carbon, low aromatic/highly aliphatic carbon, and amorphous forms of carbon. Our results clearly show the impact of graphite and amorphous C phases in the BC fraction in modern riverine sediments and nearby marine shelf deposits. The pre-anthropogenic Equatorial Pacific GBC fraction is remarkable in the existence of highly-ordered graphite

  1. Black carbon and West African Monsoon precipitation. Observations and simulations

    International Nuclear Information System (INIS)

    Huang, J.; Adams, A.; Zhang, C.; Wang, C.

    2009-01-01

    We have recently investigated large-scale co-variability between aerosol and precipitation and other meteorological variables in the West African Monsoon (WAM) region using long term satellite observations and reanalysis data. In this study we compared the observational results to a global model simulation including only direct radiative forcing of black carbon (BC). From both observations and model simulations we found that in boreal cold seasons anomalously high African aerosols are associated with significant reductions in cloud amount, cloud top height, and surface precipitation. These results suggest that the observed precipitation reduction in the WAM region is caused by radiative effect of BC. The result also suggests that the BC effect on precipitation is nonlinear. (orig.)

  2. Magnesian calcite and the problem of the origin of carbonates in the deep-sea Old Black Sea sediments

    Energy Technology Data Exchange (ETDEWEB)

    Georgiev, V M

    1988-04-01

    The Old Black Sea (Lower-Middle Holocene) deep-sea sediments in the Black Sea basin contain carbonate laminae with a fixed position in the section - in the base of the typical sapropelic muds. The areal distribution of these laminae covers the whole continental slope and rise. They are usually lacking in the sediments of the abyssal plain. XRD, SEM and EDS studies show that the laminae comprise mainly authigenic carbonates - aragonite and magnesian calcite. Aragonite occurs as elongated rice-shaped monocrystals or as diverse aggregates of elongated crystal platelets. The magnesian calcite (6-14 mol % MgCO/sub 3/) forms aggregates of isometric grains with submicritic dimensions between the aragonite grains or individual laminae consisting of idiomorphic rhombohedral and/or skeleton crystals. Low-magnesian calcite is also found sometimes. Usually it is related to Holocene coccoliths without traces of recrystallization. The laminae do not show traces of lithification. A hemogenic-synsedimentary genesis of the carbonate laminae is suggested; their mineral composition witnesses marine chemical composition of the initial solutions with a high Mg/Ca ratio.

  3. Radio Observations of Ultra-Luminous X-Ray Sources ---Microblazars or Intermediate-Mass Black Holes?---

    Science.gov (United States)

    Körding, E.; Colbert, E.; Falcke, H.

    In recent years Ultra-Luminous X-Ray sources (ULXs) received wide attention, however, their true nature is not yet understood. Many explanations have been suggested, including intermediate-mass black holes, super-Eddington accretion flows, anisotropic emission, and relativistic beaming of microquasars. We model the logN-logS distribution of ULXs assuming that each neutron star or black hole XRB can be described by an accretion disk plus jet model, where the jet is relativistically beamed. The distribution can be either fit by intermediate-mass black holes or by stellar mass black holes with mildly relativistic jets. Even though the jet is intrinsically weaker than the accretion disk, relativistic beaming can in the latter approach lead to the high fluxes observed. To further explore the possibility of microblazars contributing to the ULX phenomenon, we have embarked on a radio-monitoring study of ULXs in nearby galaxies with the VLA. However, up to now no radio flare has been detected. Using the radio/X-ray correlation the upper limits on the radio flux can be converted into upper limits for the black hole masses of MBH ≲ 10^3 M⊙.

  4. Shunting arc plasma source for pure carbon ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Koguchi, H.; Sakakita, H.; Kiyama, S.; Shimada, T.; Sato, Y.; Hirano, Y. [Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan)

    2012-02-15

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA/mm{sup 2} at the peak of the pulse.

  5. Shunting arc plasma source for pure carbon ion beam.

    Science.gov (United States)

    Koguchi, H; Sakakita, H; Kiyama, S; Shimada, T; Sato, Y; Hirano, Y

    2012-02-01

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA∕mm(2) at the peak of the pulse.

  6. Adaptation, validation and application of the chemo-thermal oxidation method to quantify black carbon in soils

    International Nuclear Information System (INIS)

    Agarwal, Tripti; Bucheli, Thomas D.

    2011-01-01

    The chemo-thermal oxidation method at 375 o C (CTO-375) has been widely used to quantify black carbon (BC) in sediments. In the present study, CTO-375 was tested and adapted for application to soil, accounting for some matrix specific properties like high organic carbon (≤39%) and carbonate (≤37%) content. Average recoveries of standard reference material SRM-2975 ranged from 25 to 86% for nine representative Swiss and Indian samples, which is similar to literature data for sediments. The adapted method was applied to selected samples of the Swiss soil monitoring network (NABO). BC content exhibited different patterns in three soil profiles while contribution of BC to TOC was found maximum below the topsoil at all three sites, however at different depths (60-130 cm). Six different NABO sites exhibited largely constant BC concentrations over the last 25 years, with short-term (6 months) prevailing over long-term (5 years) temporal fluctuations. - Research highlights: → The CTO-375 method was adapted and validated for BC analysis in soils. → Method validation figures of merit proofed satisfactory. → Application is shown with soil cores and topsoil temporal variability. → BC content can be elevated in subsurface soils. → BC contents in surface soils were largely constant over the last 25 years. - Although widely used also for soils, the chemo-thermal oxidation method at 375 o C to quantify black carbon has never been properly validated for this matrix before.

  7. Are emissions of black carbon from gasoline vehicles overestimated? Real-time, in situ measurement of black carbon emission factors.

    Science.gov (United States)

    Wang, Yang; Xing, Zhenyu; Zhao, Shuhui; Zheng, Mei; Mu, Chao; Du, Ke

    2016-03-15

    Accurately quantifying black carbon (BC) emission factors (EFs) is a prerequisite for estimation of BC emission inventory. BC EFs determined by measuring BC at the roadside or chasing a vehicle on-road may introduce large uncertainty for low emission vehicles. In this study, BC concentrations were measured inside the tailpipe of gasoline vehicles with different engine sizes under different driving modes to determine the respective EFs. BC EFs ranged from 0.005-7.14 mg/kg-fuel under the speeds of 20-70 km/h, 0.05-28.95 mg/kg-fuel under the accelerations of 0.5-1.5m/s(2). Although the water vapor in the sampling stream could result in an average of 12% negative bias, the BC EFs are significantly lower than the published results obtained with roadside or chasing vehicle measurement. It is suggested to conduct measurement at the tailpipe of gasoline vehicles instead of in the atmosphere behind the vehicles to reduce the uncertainty from fluctuation in ambient BC concentration. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Effect of carbon coating on cycle performance of LiFePO4/C composite cathodes using Tween80 as carbon source

    International Nuclear Information System (INIS)

    Huang, You-Guo; Zheng, Feng-Hua; Zhang, Xiao-Hui; Li, Qing-Yu; Wang, Hong-Qiang

    2014-01-01

    Highlights: • The Tween80 addition could enhance cycle stability of LiFePO 4 material. • The FTIR spectrum confirms Tween80 surfactant can bond with LiFePO 4 particles. • Some chemical bonds between material and carbon layer still exist after sintering. - Abstract: The influence of carbon coating on the cycle performance of LiFePO 4 /C composite cathodes using polyoxyethylenesorbitan monooleate (Tween80) as carbon source against lithium metal foil anode for Li-ion batteries was investigated in this paper. According to Infrared spectrum analysis (FTIR), the Tween80 surfactant molecules bond to the surface of LiFePO 4 and form an adsorption layer, which contribute to the formation of a homogeneous carbon layer tightly coating on the surface of LiFePO 4 particles in the process of sintering, due to a strong binding force provided by surface chemical bonds. The transmission electron microscopy (TEM) shows that the carbon layer around LiFePO 4 using Tween80 as carbon source still coating on the surface of LiFePO 4 after 200 cycles at 5 C rate while the carbon layer shed from the surface of LiFePO 4 using glucose as carbon source. As a result, the carbon-coated LiFePO 4 using Tween80 as carbon source exhibits much higher capacity retention than the sample using glucose as carbon source. Electrochemical impedance measurement (EIS) reveals that the carbon-coated LiFePO 4 electrode using Tween80 surfactant has a lower charge transfer resistance than the electrode using glucose as carbon source electrode after 100 and 200 cycles at 5 C rate

  9. Implication of using different carbon sources for denitrification in wastewater treatments.

    Science.gov (United States)

    Cherchi, Carla; Onnis-Hayden, Annalisa; El-Shawabkeh, Ibrahim; Gu, April Z

    2009-08-01

    Application of external carbon sources for denitrification becomes necessary for wastewater treatment plants that have to meet very stringent effluent nitrogen limits (e.g., 3 to 5 mgTN/L). In this study, we evaluated and compared three carbon sources--MicroC (Environmental Operating Solutions, Bourne, Massachusetts), methanol, and acetate-in terms of their denitrification rates and kinetics, effect on overall nitrogen removal performance, and microbial community structure of carbon-specific denitrifying enrichments. Denitrification rates and kinetics were determined with both acclimated and non-acclimated biomass, obtained from laboratory-scale sequencing batch reactor systems or full-scale plants. The results demonstrate the feasibility of the use of MicroC for denitrification processes, with maximum denitrification rates (k(dmax)) of 6.4 mgN/gVSSh and an observed yield of 0.36 mgVSS/mgCOD. Comparable maximum nitrate uptake rates were found with methanol, while acetate showed a maximum denitrification rate nearly twice as high as the others. The maximum growth rates measured at 20 degrees C for MicroC and methanol were 3.7 and 1.2 day(-1), respectively. The implications resulting from the differences in the denitrification rates and kinetics of different carbon sources on the full-scale nitrogen removal performance, under various configurations and operational conditions, were assessed using Biowin (EnviroSim Associates, Ltd., Flamborough, Ontario, Canada) simulations for both pre- and post-denitrification systems. Examination of microbial population structures using Automated Ribosomal Intergenic Spacer Analysis (ARISA) throughout the study period showed dynamic temporal changes and distinct microbial community structures of different carbon-specific denitrifying cultures. The ability of a specific carbon-acclimated denitrifying population to instantly use other carbon source also was investigated, and the chemical-structure-associated behavior patterns observed

  10. Reinforcing effect of plasma modified halloysite nanotubes in a carbon black filled natural rubber-butadien rubber matrix

    NARCIS (Netherlands)

    Poikelispaa, Minna; Das, Amit; Dierkes, Wilma K.; Vuorinen, Jyrki

    2011-01-01

    Rubber composites are generally produced by the direct incorporation of fillers like carbon black and/or silica into the rubber matrix. The incorporation of different types of nanofillers is the subject of recent research with the aim of preparing composites with special compositions and properties.

  11. Selective Oxidation of Soft Grade Carbon

    Directory of Open Access Journals (Sweden)

    Zecevic, N.

    2007-12-01

    Full Text Available Oil-furnace carbon black is produced by pyrolysis of gaseous or liquid hydrocarbons or their mixtures. The oil feedstock for the production of oil-furnace carbon black is mainly composed of high-boiling aromatic hydrocarbons, which are residues of petroleum cracking, while the gaseous raw material is commonly natural gas. Most of the oil-furnace carbon black production (> 99 % is used as a reinforcing agent in rubber compounds. Occasionally, oil-furnace carbon blacks are used in contact with other rubber compounds and fillers that have different pigments, particularly with the color white. It has been observed that frequently a migrating rubber soluble colorant would enter the white or light colored rubber composition from the adjacent carbon black filled rubber, resulting in a highly undesirable staining effect. Methods for determining non-oxidized residue on the surface of the oil-furnace carbon black include extraction of carbon black with the appropriate organic solvent, and measuring the color of the organic solvent by means of a colorimeter on 425 nm (ASTM D 1618-99. Transmittance values of 85 % or more are indicative of a practically non-staining carbon black, while transmittance values below 50 % generally lead to a carbon black with pronounced staining characteristics. Many oil-furnace carbon blacks, particularly those with a larger particle size (dp > 50 nm which are produced by pyrolysis, have strongly adsorbed non-reacted oil on their surfaces. Upon incorporation in a rubber compound, the colored materials are gradually dissolved by the rubber matrix and migrate freely into adjacent light colored rubber compounds, causing a highly objectionable staining effect. Adjusting furnace parameters in the industrial process of producing specific soft grades of carbon black cannot obtain minimal values of toluene discoloration. The minimal value of toluene discoloration is very important in special applications. Therefore, after-treatment of

  12. About opportunity of development of photo-diodes capable to work at 2326 sm-1 from carbon black filled polystyrene

    International Nuclear Information System (INIS)

    Akhmedov, U.Kh.; Tukhtaev, G.M.; Umirzakov, B.E.

    2004-01-01

    Full text: In essential progress in nano-electronics have resulted works connected with creation of active components of electronic engineering from cluster forms of carbon (CFC). For example, physical principles of reception of transistor effect from an individual molecule fullerene C 60 are already discussed, results of development of photo-diodes from system poly-thiophene - fullerene C 60 also are submitted. CFC usually synthesize separately. However, our researches have shown an opportunity of compulsory formation of some part of agglomerates of carbon black in final and intermediate products fullerene C 60 during preparation of composites of polystyrene (PS) at filling by its usual amorphous carbon black. Roentgenograms of initial composites, i.e. carbon black and PS, had only amorphous pieces, without what or crystal peaks whereas the roentgenogram of a composite had set of new peaks connected with crystallization. Calculations have shown conformity to within 1-2 % of size of inter plane distance of the most intensive peak in the roentgenogram of a composite 0.3599 nm with that distance for radius of molecule C 60 which makes 0.357 nm. IR-spectra of a composite with such strips of absorption as: 1434; 1174; 500 and 1650; 1577 sm -1 practically confirm presence of unary and double communications between atoms of carbon, characteristic for molecule C 60 . The inter plane distance under the roentgenogram of a composite equal 0.33588 nm to within 1-2 % corresponds to literary size of interlayer distance in such microtube equal 0.34 nm. Actually the technology of preparation applied by us in the given work, has resulted in formation multilayered in structure of this material. It agrees to data ESR of spectroscopy in a boundary layer of a composite ions H 3 O 2 , and H 5 O 2 are formed or donor-acceptor complexes, or with weak communication, for example, (H 2 O) 2 or with strong communication, for example. Results dielectric, ESR and IR-spectroscopy allow to count

  13. Utilizing Colored Dissolved Organic Matter to Derive Dissolved Black Carbon Export by Arctic Rivers

    Science.gov (United States)

    Stubbins, Aron; Spencer, Robert; Mann, Paul; Holmes, R.; McClelland, James; Niggemann, Jutta; Dittmar, Thorsten

    2015-10-01

    Wildfires have produced black carbon (BC) since land plants emerged. Condensed aromatic compounds, a form of BC, have accumulated to become a major component of the soil carbon pool. Condensed aromatics leach from soils into rivers, where they are termed dissolved black carbon (DBC). The transport of DBC by rivers to the sea is a major term in the global carbon and BC cycles. To estimate Arctic river DBC export, 25 samples collected from the six largest Arctic rivers (Kolyma, Lena, Mackenzie, Ob’, Yenisey and Yukon) were analyzed for dissolved organic carbon (DOC), colored dissolved organic matter (CDOM), and DBC. A simple, linear regression between DOC and DBC indicated that DBC accounted for 8.9 ± 0.3% DOC exported by Arctic rivers. To improve upon this estimate, an optical proxy for DBC was developed based upon the linear correlation between DBC concentrations and CDOM light absorption coefficients at 254 nm (a254). Relatively easy to measure a254 values were determined for 410 Arctic river samples between 2004 and 2010. Each of these a254 values was converted to a DBC concentration based upon the linear correlation, providing an extended record of DBC concentration. The extended DBC record was coupled with daily discharge data from the six rivers to estimate riverine DBC loads using the LOADEST modeling program. The six rivers studied cover 53% of the pan-Arctic watershed and exported 1.5 ± 0.1 million tons of DBC per year. Scaling up to the full area of the pan-Arctic watershed, we estimate that Arctic rivers carry 2.8 ± 0.3 million tons of DBC from land to the Arctic Ocean each year. This equates to ~8% of Arctic river DOC export, slightly less than indicated by the simpler DBC vs DOC correlation-based estimate. Riverine discharge is predicted to increase in a warmer Arctic. DBC export was positively correlated with river runoff, suggesting that the export of soil BC to the Arctic Ocean is likely to increase as the Arctic warms.

  14. Utilizing Colored Dissolved Organic Matter to Derive Dissolved Black Carbon Export by Arctic Rivers

    Directory of Open Access Journals (Sweden)

    Aron eStubbins

    2015-10-01

    Full Text Available Wildfires have produced black carbon (BC since land plants emerged. Condensed aromatic compounds, a form of BC, have accumulated to become a major component of the soil carbon pool. Condensed aromatics leach from soils into rivers, where they are termed dissolved black carbon (DBC. The transport of DBC by rivers to the sea is a major term in the global carbon and BC cycles. To estimate Arctic river DBC export, 25 samples collected from the six largest Arctic rivers (Kolyma, Lena, Mackenzie, Ob’, Yenisey and Yukon were analyzed for dissolved organic carbon (DOC, colored dissolved organic matter (CDOM, and DBC. A simple, linear regression between DOC and DBC indicated that DBC accounted for 8.9 ± 0.3% DOC exported by Arctic rivers. To improve upon this estimate, an optical proxy for DBC was developed based upon the linear correlation between DBC concentrations and CDOM light absorption coefficients at 254 nm (a254. Relatively easy to measure a254 values were determined for 410 Arctic river samples between 2004 and 2010. Each of these a254 values was converted to a DBC concentration based upon the linear correlation, providing an extended record of DBC concentration. The extended DBC record was coupled with daily discharge data from the six rivers to estimate riverine DBC loads using the LOADEST modeling program. The six rivers studied cover 53% of the pan-Arctic watershed and exported 1.5 ± 0.1 million tons of DBC per year. Scaling up to the full area of the pan-Arctic watershed, we estimate that Arctic rivers carry 2.8 ± 0.3 million tons of DBC from land to the Arctic Ocean each year. This equates to ~8% of Arctic river DOC export, slightly less than indicated by the simpler DBC vs DOC correlation-based estimate. Riverine discharge is predicted to increase in a warmer Arctic. DBC export was positively correlated with river runoff, suggesting that the export of soil BC to the Arctic Ocean is likely to increase as the Arctic warms.

  15. End of the "Little Ice Age" in the Alps not forced by industrial black carbon

    Science.gov (United States)

    Sigl, Michael; Osmont, Dimtri; Gabrieli, Jacopo; Barbante, Carlo; Schwikowski, Margit

    2016-04-01

    Light absorbing aerosols present in the atmosphere and cryosphere play an important role in the climate system. Their presence in ambient air and snow changes radiative properties of these media, thus contributing to increased atmospheric warming and snowmelt. High spatio-temporal variability of aerosol concentrations in these media and a shortage of long-term observations contribute to large uncertainties in properly assigning the climate effects of these aerosols through time. Glaciers in the European Alps began to retreat abruptly from their mid-19th century maximum, marking what appeared to be the end of the Little Ice Age. Radiative forcing by increasing deposition of industrial black carbon to snow has been suggested as the main driver of the abrupt glacier retreats in the Alps (Painter et al. 2012). Basis for this hypothesis were model simulations using ice-core measurements of elemental carbon at low temporal resolution from two ice cores in the Alps. Here we present sub-annually resolved, well replicated ice-core measurements of refractory black carbon (rBC; using a SP2 soot photometer), mineral dust (Fe, Ca), biomass burning (NH4, K) and distinctive industrial pollution tracers (Bi, Pb, SO4) from an ice core in the Alps covering the past 250 years. These reconstructions allow to precisely compare the timing of observed acceleration of glacier melt in the mid-19th century with that of the increase of soot deposition on ice-sheets caused by the industrialization of Western Europe. Our study suggests that at the time when European rBC emission rates started to significantly increase Alpine glaciers have already experienced more than 70% of their total 19th century length reduction. Industrial BC emissions can therefore not been considered as the primary forcing of the rapid deglaciation at the end of the Little Ice Age in the Alps. References: Painter, T. H., M. G. Flanner, G. Kaser, B. Marzeion, R. A. VanCuren, and W. Abdalati (2013), End of the Little Ice

  16. On the Use of the Field Sunset Semi-continuous Analyzer to Measure Equivalent Black Carbon Concentrations.

    Czech Academy of Sciences Publication Activity Database

    Zíková, Naděžda; Vodička, Petr; Ludwig, W.; Hitzenberger, R.; Schwarz, Jaroslav

    2016-01-01

    Roč. 50, č. 3 (2016), s. 284-296 ISSN 0278-6826 R&D Projects: GA ČR(CZ) GBP503/12/G147; GA MŠk 7AMB12AT021 Institutional support: RVO:67985858 Keywords : black carbon * aerosols * aethalometer Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.926, year: 2016

  17. Mutation spectrum in FE1-MUTA(TM) Mouse lung epithelial cells exposed to nanoparticulate carbon black

    DEFF Research Database (Denmark)

    Jacobsen, Nicklas Raun; White, Paul A; Gingerich, John

    2011-01-01

    It has been shown previously that carbon black (CB), Printex 90 exposure induces cII and lacZ mutants in the FE1-Muta(TM) Mouse lung epithelial cell line and causes oxidatively damaged DNA and the production of reactive oxygen species (ROS). The purpose of this study was to determine the mutation...

  18. Black Carbon Radiative Forcing over the Tibetan Plateau

    Energy Technology Data Exchange (ETDEWEB)

    He, Cenlin; Li, Qinbin; Liou, K. N.; Takano, Y.; Gu, Yu; Qi, L.; Mao, Yuhao; Leung, Lai-Yung R.

    2014-11-28

    We estimate the snow albedo forcing and direct radiative forcing (DRF) of black carbon (BC) in the Tibetan Plateau using a global chemical transport model in conjunction with a stochastic snow model and a radiative transfer model. Our best estimate of the annual BC snow albedo forcing in the Plateau is 2.9 W m-2 (uncertainty: 1.5–5.0 W m-226 ). We find that BC-snow internal mixing increases the albedo forcing by 40-60% compared with external mixing and coated BC increases the forcing by 30-50% compared with uncoated BC, whereas Koch snowflakes reduce the forcing by 20-40% relative to spherical snow grains. Our best estimate of the annual BC DRF at the top of the atmosphere is 2.3 W m-2 (uncertainty: 0.7–4.3 W m-230 ) in the Plateau after scaling the modeled BC absorption optical depth to Aerosol Robotic Network (AERONET) observations. The BC forcings are attributed to emissions from different regions.

  19. Comparative studies of industrial grade carbon black powders

    Energy Technology Data Exchange (ETDEWEB)

    Chawla, Komal, E-mail: komalchawla.rs@gmail.com; Chauhan, Alok P. S., E-mail: chauhan.alok@gmail.com, E-mail: alok.chauhan@alumni.stonybrook.edu [Department of Physics and Material Science and Engineering, Jaypee Institute of Information Technology, A-10, Sector-62, Noida-201307, UP, India. (India)

    2016-05-06

    Comparative studies of two dissimilar industrial grade Carbon Black (CB) powders (N375 and N405) were conducted. The structure, surface area and particle size are the three important characteristics of CB powder that determine their processability and application as filler in preparing rubber compounds. The powders were characterized for their structure using dibutyl phthalate absorption (DBPA), particle size via laser particle size analyzer and surface area by nitrogen adsorption method. The structural characterization showed that N405 had lower DBPA in comparison to N375, confirming low structure of N405 grade CB powder. It was observed from the particle size analysis that N375 was coarser than N405 grade CB. The total surface area values were determined by the BET method based on the cross sectional area of the nitrogen molecule. N375, a coarse grade CB powder with high structure, depicted less surface area as compared to N405.

  20. Study of tribological properties of natural rubber containing carbon nanotubes and carbon black as hybrid fillers

    Science.gov (United States)

    Harea, Evghenii; Stoček, Radek; Storozhuk, Liudmyla; Sementsov, Yurii; Kartel, Nikolai

    2018-04-01

    Dry friction and wear properties of natural rubber (NR), containing multi-walled carbon nanotubes (MWCNT) and carbon black (CB), were investigated. Natural rubber (NR)-based composites containing all common additives and curatives, and a fixed amount (30 phr—parts per 100 rubber by weight) of hybrid fillers (MWCNT x + CB30-x ) were prepared by simple mixing procedure and tested. The main goal was to study the behaviours of composites at different tribological testing conditions, such as friction speed and normal load. It was found that with an increase of concentration of MWCNT from x = 0 phr to x = 5 phr in studied composites, there was a decrease in the coefficient of friction (COF) with no significant change in wear in the framework of each used combination of testing parameters. Generally, higher friction speed at certain normal force led to the increase of COF of all the samples and wear reflected deliberate value fluctuation. Also, it was established that considerable growth of wear and unexpected reducing of friction coefficient ensued from increasing of applied load for every fixed sliding speed.

  1. Wintertime aerosol chemical composition and source apportionment of the organic fraction in the metropolitan area of Paris

    Directory of Open Access Journals (Sweden)

    M. Crippa

    2013-01-01

    Full Text Available The effect of a post-industrial megacity on local and regional air quality was assessed via a month-long field measurement campaign in the Paris metropolitan area during winter 2010. Here we present source apportionment results from three aerosol mass spectrometers and two aethalometers deployed at three measurement stations within the Paris region. Submicron aerosol composition is dominated by the organic fraction (30–36% and nitrate (28–29%, with lower contributions from sulfate (14–16%, ammonium (12–14% and black carbon (7–13%.

    Organic source apportionment was performed using positive matrix factorization, resulting in a set of organic factors corresponding both to primary emission sources and secondary production. The dominant primary sources are traffic (11–15% of organic mass, biomass burning (13–15% and cooking (up to 35% during meal hours. Secondary organic aerosol contributes more than 50% to the total organic mass and includes a highly oxidized factor from indeterminate and/or diverse sources and a less oxidized factor related to wood burning emissions. Black carbon was apportioned to traffic and wood burning sources using a model based on wavelength-dependent light absorption of these two combustion sources. The time series of organic and black carbon factors from related sources were strongly correlated. The similarities in aerosol composition, total mass and temporal variation between the three sites suggest that particulate pollution in Paris is dominated by regional factors, and that the emissions from Paris itself have a relatively low impact on its surroundings.

  2. Endothelial dysfunction in normal and prediabetic rats with metabolic syndrome exposed by oral gavage to carbon black nanoparticles

    DEFF Research Database (Denmark)

    Folkmann, Janne Kjærsgaard; Vesterdal, Lise Kristine; Sheykhzade, Majid

    2012-01-01

    Exposure to nanosized particles may increase the risk of cardiovascular diseases by endothelial dysfunction, particularly in susceptible subjects with metabolic syndrome. We investigated vasomotor dysfunction in aorta from obese and lean Zucker rats after oral exposure to nanosized carbon black (...

  3. Multiple scattering of light by water cloud droplets with external and internal mixing of black carbon aerosols

    International Nuclear Information System (INIS)

    Wang Hai-Hua; Sun Xian-Ming

    2012-01-01

    The mixture of water cloud droplets with black carbon impurities is modeled by external and internal mixing models. The internal mixing model is modeled with a two-layered sphere (water cloud droplets containing black carbon (BC) inclusions), and the single scattering and absorption characteristics are calculated at the visible wavelength of 0.55 μm by using the Lorenz—Mie theory. The external mixing model is developed assuming that the same amount of BC particles are mixed with the water droplets externally. The multiple scattering characteristics are computed by using the Monte Carlo method. The results show that when the size of the BC aerosol is small, the reflection intensity of the internal mixing model is bigger than that of the external mixing model. However, if the size of the BC aerosol is big, the absorption of the internal mixing model will be larger than that of the external mixing model. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  4. Laboratory Validation of Four Black Carbon Measurement Methods for Determination of the Nonvolatile Particulate Matter (nvPM) Mass Emissions from Commercial Aircraft Engines

    Science.gov (United States)

    Four candidate black carbon (BC) measurement techniques have been identified by the SAE International E-31 Committee for possible use in determining nonvolatile particulate matter (nvPM) mass emissions during commercial aircraft engine certification. These techniques are carbon b...

  5. A Precisely Assembled Carbon Source to Synthesize Fluorescent Carbon Quantum Dots for Sensing Probes and Bioimaging Agents.

    Science.gov (United States)

    Qiao, Yiqiang; Luo, Dan; Yu, Min; Zhang, Ting; Cao, Xuanping; Zhou, Yanheng; Liu, Yan

    2018-02-09

    A broad range of carbon sources have been used to fabricate varieties of carbon quantum dots (CQDs). However, the majority of these studies concern the influence of primary structures and chemical compositions of precursors on the CQDs; it is still unclear whether or not the superstructures of carbon sources have effects on the physiochemical properties of the synthetic CQDs. In this work, the concept of molecular assembly is first introduced into the design of a new carbon source. Compared with the tropocollagen molecules, the hierarchically assembled collagen scaffolds, as a new carbon source, immobilize functional groups of the precursors through hydrogen bonds, electrostatic attraction, and hydrophobic forces. Moreover, the accumulation of functional groups in collagen self-assembly further promotes the covalent bond formation in the obtained CQDs through a hydrothermal process. Both of these two chemical superiorities give rise to high quality CQDs with enhanced emission. The assembled collagen scaffold-based CQDs with heteroatom doping exhibit superior stability, and could be further applied as effective fluorescent probes for Fe 3+ detection and cellular cytosol imaging. These findings open a wealth of possibilities to explore more nanocarbons from precursors with assembled superstructures. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Carbon footprint of urban source separation for nutrient recovery.

    Science.gov (United States)

    Kjerstadius, H; Bernstad Saraiva, A; Spångberg, J; Davidsson, Å

    2017-07-15

    Source separation systems for the management of domestic wastewater and food waste has been suggested as more sustainable sanitation systems for urban areas. The present study used an attributional life cycle assessment to investigate the carbon footprint and potential for nutrient recovery of two sanitation systems for a hypothetical urban area in Southern Sweden. The systems represented a typical Swedish conventional system and a possible source separation system with increased nutrient recovery. The assessment included the management chain from household collection, transport, treatment and final return of nutrients to agriculture or disposal of the residuals. The results for carbon footprint and nutrient recovery (phosphorus and nitrogen) concluded that the source separation system could increase nutrient recovery (0.30-0.38 kg P capita -1 year -1 and 3.10-3.28 kg N capita -1 year -1 ), while decreasing the carbon footprint (-24 to -58 kg CO 2 -eq. capita -1 year -1 ), compared to the conventional system. The nutrient recovery was increased by the use of struvite precipitation and ammonium stripping at the wastewater treatment plant. The carbon footprint decreased, mainly due to the increased biogas production, increased replacement of mineral fertilizer in agriculture and less emissions of nitrous oxide from wastewater treatment. In conclusion, the study showed that source separation systems could potentially be used to increase nutrient recovery from urban areas, while decreasing the climate impact. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Inferring absorbing organic carbon content from AERONET data

    Directory of Open Access Journals (Sweden)

    A. Arola

    2011-01-01

    Full Text Available Black carbon, light-absorbing organic carbon (often called "brown carbon" and mineral dust are the major light-absorbing aerosols. Currently the sources and formation of brown carbon aerosol in particular are not well understood. In this study we estimated the amount of light–absorbing organic carbon and black carbon from AERONET measurements. We find that the columnar absorbing organic carbon (brown carbon levels in biomass burning regions of South America and Africa are relatively high (about 15–20 mg m−2 during biomass burning season, while the concentrations are significantly lower in urban areas in US and Europe. However, we estimated significant absorbing organic carbon amounts from the data of megacities of newly industrialized countries, particularly in India and China, showing also clear seasonality with peak values up to 30–35 mg m−2 during the coldest season, likely caused by the coal and biofuel burning used for heating. We also compared our retrievals with the modeled organic carbon by the global Oslo CTM for several sites. Model values are higher in biomass burning regions than AERONET-based retrievals, while the opposite is true in urban areas in India and China.

  8. Geology of the Devonian black shales of the Appalachian Basin

    Science.gov (United States)

    Roen, J.B.

    1984-01-01

    Black shales of Devonian age in the Appalachian Basin are a unique rock sequence. The high content of organic matter, which imparts the characteristic lithology, has for years attracted considerable interest in the shales as a possible source of energy. The recent energy shortage prompted the U.S. Department of Energy through the Eastern Gas Shales Project of the Morgantown Energy Technology Center to underwrite a research program to determine the geologic, geochemical, and structural characteristics of the Devonian black shales in order to enhance the recovery of gas from the shales. Geologic studies by Federal and State agencies and academic institutions produced a regional stratigraphic network that correlates the 15 ft black shale sequence in Tennessee with 3000 ft of interbedded black and gray shales in central New York. These studies correlate the classic Devonian black shale sequence in New York with the Ohio Shale of Ohio and Kentucky and the Chattanooga Shale of Tennessee and southwestern Virginia. Biostratigraphic and lithostratigraphic markers in conjunction with gamma-ray logs facilitated long-range correlations within the Appalachian Basin. Basinwide correlations, including the subsurface rocks, provided a basis for determining the areal distribution and thickness of the important black shale units. The organic carbon content of the dark shales generally increases from east to west across the basin and is sufficient to qualify as a hydrocarbon source rock. Significant structural features that involve the black shale and their hydrocarbon potential are the Rome trough, Kentucky River and Irvine-Paint Creek fault zone, and regional decollements and ramp zones. ?? 1984.

  9. Carbon a support for sulfide catalysts

    NARCIS (Netherlands)

    Vissers, J.P.R.; Lensing, T.J.; Mercx, F.P.M.; Beer, de V.H.J.; Prins, R.

    1983-01-01

    Two types of carbon materials, carbon black composite and carbon covered alumina, were studied for-their use as support for sulfide catalysts. The following parameters were varied: type of carbon black, carbon coverage of the alumina and carbon pretreatment. Pore size distributions were determined

  10. Black carbon in the atmosphere and snow, from pre-industrial times until present

    Directory of Open Access Journals (Sweden)

    R. B. Skeie

    2011-07-01

    Full Text Available The distribution of black carbon (BC in the atmosphere and the deposition of BC on snow surfaces since pre-industrial time until present are modelled with the Oslo CTM2 model. The model results are compared with observations including recent measurements of BC in snow in the Arctic. The global mean burden of BC from fossil fuel and biofuel sources increased during two periods. The first period, until 1920, is related to increases in emissions in North America and Europe, and the last period after 1970 are related mainly to increasing emissions in East Asia. Although the global burden of BC from fossil fuel and biofuel increases, in the Arctic the maximum atmospheric BC burden as well as in the snow was reached in 1960s, with a slight reduction thereafter. The global mean burden of BC from open biomass burning sources has not changed significantly since 1900. With current inventories of emissions from open biomass sources, the modelled burden of BC in snow and in the atmosphere north of 65° N is small compared to the BC burden of fossil fuel and biofuel origin. From the concentration changes radiative forcing time series due to the direct aerosol effect as well as the snow-albedo effect is calculated for BC from fossil fuel and biofuel. The calculated radiative forcing in 2000 for the direct aerosol effect is 0.35 W m−2 and for the snow-albedo effect 0.016 W m−2 in this study. Due to a southward shift in the emissions there is an increase in the lifetime of BC as well as an increase in normalized radiative forcing, giving a change in forcing per unit of emissions of 26 % since 1950.

  11. A pressure-sensitive carbon black cement composite for traffic monitoring

    KAUST Repository

    Monteiro, A.O.

    2017-08-17

    Recent advances in nanotechnology have guided the development of a new generation of multifunctional construction materials. An example of this are cement-based composites, some of which can be used not just to pave roads but also to monitor them. A cement composite, integrating a carbon black (CB) filler, was used as a piezoresistive sensor to identify different cyclic compressive loadings, at temperatures ranging from 15°C to 45°C. The mechanical essays were performed under realistic conditions using 600cm3 specimens and uniaxial loads typical of automobile traffic. A linear and reversible pressure-sensing performance was found with gauge factors ranging from 40 to 60. Overall, these results show that CB/cement composites can act as stress-sensitive materials for traffic monitoring.

  12. Particulate matter and black carbon optical properties and emission factors from prescribed fires in the southeastern United States

    Science.gov (United States)

    The aerosol emissions from prescribed fires in the Southeastern United States were measured and compared to emissions from laboratory burns with fuels collected from the site. Fine particulate matter (PM2.5), black carbon, and aerosol light scattering and absorption were characte...

  13. Influence of black carbon addition on phenanthrene dissipation and microbial community structure in soil

    International Nuclear Information System (INIS)

    Wang Ping; Wang Haizhen; Wu Laosheng; Di Hongjie; He Yan; Xu Jianming

    2012-01-01

    Biodegradation processes and changes in microbial community structure were investigated in black carbon (BC) amended soils in a laboratory experiment using two soils (black soil and red soil). We applied different percentages of charcoal as BC (0%, 0.5% and 1% by weight) with 100 mg kg −1 of phenanthrene. Soil samples were collected at different incubation times (0, 7, 15, 30, 60, 120 d). The amendment with BC caused a marked decrease in the dissipation (ascribed to mainly degradation and/or sequestration) of phenanthrene residues from soil. Extracted phenanthrene in black soil with 1% BC were higher, oppositely in red soil, 0.5% BC amendments were higher. There were significant changes in the PLFA pattern in phenanthrene-spiked soils with time but BC had little effect on the microbial community structure of phenanthrene-spiked soils, as indicated by principal component analysis (PCA) of the PLFA signatures. - Highlights: ► Extracted phenanthrene increased substantially as the BC amount increased. ► Extracted phenanthrene in black soil with 1% BC were higher, oppositely in red soil. ► BC caused a marked decrease in the dissipation of phenanthrene from soil. ► PLFA pattern in phenanthrene-spiked soils with time had significant changes. - BC amendments on phenanthrene extraction were different for two soils and time was a more effective factor in microbial community changes.

  14. Tethered balloon-based black carbon profiles within the lower troposphere of Shanghai in the 2013 East China smog

    Science.gov (United States)

    Li, Juan; Fu, Qingyan; Huo, Juntao; Wang, Dongfang; Yang, Wen; Bian, Qinggen; Duan, Yusen; Zhang, Yihua; Pan, Jun; Lin, Yanfen; Huang, Kan; Bai, Zhipeng; Wang, Sheng-Hsiang; Fu, Joshua S.; Louie, Peter K. K.

    2015-12-01

    low concentrations near the top of the boundary layer around 200 m. Above the boundary layer, BC increased with altitudes and reached a maximum at the top of 1000 m. Prevailing sea breeze within the boundary layer was mainly responsible for the quick cleanup of BC in the lower altitudes. In contrast, continental outflow via regional transport was the major cause of the enhanced BC aloft. This study provides a first insight of the black carbon vertical profiles over Eastern China, which will have significant implications for narrowing the gaps between the source emissions and observations as well as improving estimations of BC radiative forcing and regional climate.

  15. A potential explanation for the effect of carbon source on the ...

    African Journals Online (AJOL)

    This paper proposes a new theory to account for the effect of carbon source on the characteristics of acetate-fed and glucose-fed aerobic granules. It is well known that reactor pH can vary in response to the oxidation of glucose or sodium acetate. As such, the effects associated with the carbon sources may be explained by ...

  16. Carbon isotopes of dissolved inorganic carbon reflect utilization of different carbon sources by microbial communities in two limestone aquifer assemblages

    Directory of Open Access Journals (Sweden)

    M. E. Nowak

    2017-08-01

    Full Text Available Isotopes of dissolved inorganic carbon (DIC are used to indicate both transit times and biogeochemical evolution of groundwaters. These signals can be complicated in carbonate aquifers, as both abiotic (i.e., carbonate equilibria and biotic factors influence the δ13C and 14C of DIC. We applied a novel graphical method for tracking changes in the δ13C and 14C of DIC in two distinct aquifer complexes identified in the Hainich Critical Zone Exploratory (CZE, a platform to study how water transport links surface and shallow groundwaters in limestone and marlstone rocks in central Germany. For more quantitative estimates of contributions of different biotic and abiotic carbon sources to the DIC pool, we used the NETPATH geochemical modeling program, which accounts for changes in dissolved ions in addition to C isotopes. Although water residence times in the Hainich CZE aquifers based on hydrogeology are relatively short (years or less, DIC isotopes in the shallow, mostly anoxic, aquifer assemblage (HTU were depleted in 14C compared to a deeper, oxic, aquifer complex (HTL. Carbon isotopes and chemical changes in the deeper HTL wells could be explained by interaction of recharge waters equilibrated with post-bomb 14C sources with carbonates. However, oxygen depletion and δ13C and 14C values of DIC below those expected from the processes of carbonate equilibrium alone indicate considerably different biogeochemical evolution of waters in the upper aquifer assemblage (HTU wells. Changes in 14C and 13C in the upper aquifer complexes result from a number of biotic and abiotic processes, including oxidation of 14C-depleted OM derived from recycled microbial carbon and sedimentary organic matter as well as water–rock interactions. The microbial pathways inferred from DIC isotope shifts and changes in water chemistry in the HTU wells were supported by comparison with in situ microbial community structure based on 16S rRNA analyses. Our findings

  17. Lead pollution and its sources along the Turkish coast of the Black Sea

    Directory of Open Access Journals (Sweden)

    M. UNSAL

    2001-12-01

    Full Text Available Lead pollution and its sources have been investigated in the south-eastern and south-western Black Sea. Surficial sediments and mussels were collected in different seasons of the year from the south-eastern and south-western Black Sea and analysed for their lead contents. In the south-eastern Black Sea sediments from the easternmost and from the central stations contained the highest lead concentrations. Sediments contained 8 to 10 times the lead concentrations of sediments from the south-west. Samples taken from rivers, streams and effluents had especially high lead concentrations. The highest lead concentrations were found in sediments collected in October and December. Lead concentrations in mussels from the south-eastern coast were comparatively lower compared to those from the south-western coast. The highest average values occurred in December and in October. In the south-western Black Sea, the highest lead concentrations in sediments were obtained in those from Inebolu, followed by those from around Zonguldak. The concentrations increased from the middle to the west of the southern Black Sea coast, possibly due to the effect of the Danube River. Sediments taken in September had the highest lead concentrations, followed by samples taken in December. Very high lead concentrations (> 10 μ g g-1 were observed in mussels from those stations where the sediments also contained high concentrations. Mussels had their highest lead concentrations in January and April.