Science.gov

Sample records for carbon abatement potential

  1. A Regionally-Specific Assessment of the Carbon Abatement Potential of Biochar

    NASA Astrophysics Data System (ADS)

    Birch, G.; Field, J.; Keske, C.; DeFoort, M.; Cotrufo, M.

    2012-12-01

    Biochar, the solid carbon-rich co-product of certain bioenergy conversion technologies, is receiving a great deal of attention as a strategy for sequestering carbon in soils and improving the performance of agricultural systems. Several studies have attempted to quantify the lifecycle carbon abatement potential of biochar systems, considering emissions associated with feedstock provisioning and processing, energy co-production, agronomic system impacts (yield increases and nitrous oxide emission suppression), and the recalcitrance of biochar in soil, as well as accounting for the carbon abatement value of using the char as a fuel that is foregone when it is used as a soil amendment instead. These assessments typically focus on biochar production in advanced, efficient slow pyrolysis systems, despite the fact that much biochar is currently produced through small-scale carbonization or gasification systems that lack energy recovery or even emission control capability. Here, a mechanistic biochar system assessment model is presented, capable of estimating system carbon abatement value and profitability for different feedstocks, conversion technologies and temperatures, and application into different agricultural soils. The variation of biochar recalcitrance in soil as a function of production temperature is considered, and agricultural impacts are assessed in the context of biochar's liming value, an effect that is straightforward to quantify and that has often been implicated in observed crop yield increases or nitrous oxide emission reductions. The analysis is rigorous in that tradeoffs between biochar production quantity and quality are endogenized, but conservative in that other potential agronomic benefits of biochar (e.g. improved soil water holding capacity) are not considered. This model is applied to a case study of bioenergy and biochar co-production in northern Colorado using beetle-killed pine wood and slash as a feedstock. Preliminary results suggest that

  2. Potential Cost-Effective Opportunities for Methane Emission Abatement

    SciTech Connect

    Warner, Ethan; Steinberg, Daniel; Hodson, Elke; Heath, Garvin

    2015-08-01

    The energy sector was responsible for approximately 84% of carbon dioxide equivalent (CO2e) greenhouse gas (GHG) emissions in the U.S. in 2012 (EPA 2014a). Methane is the second most important GHG, contributing 9% of total U.S. CO2e emissions. A large portion of those methane emissions result from energy production and use; the natural gas, coal, and oil industries produce approximately 39% of anthropogenic methane emissions in the U.S. As a result, fossil-fuel systems have been consistently identified as high priority sectors to contribute to U.S. GHG reduction goals (White House 2015). Only two studies have recently attempted to quantify the abatement potential and cost associated with the breadth of opportunities to reduce GHG emissions within natural gas, oil, and coal supply chains in the United States, namely the U.S. Environmental Protection Agency (EPA) (2013a) and ICF (2014). EPA, in its 2013 analysis, estimated the marginal cost of abatement for non-CO2 GHG emissions from the natural gas, oil, and coal supply chains for multiple regions globally, including the United States. Building on this work, ICF International (ICF) (2014) provided an update and re-analysis of the potential opportunities in U.S. natural gas and oil systems. In this report we synthesize these previously published estimates as well as incorporate additional data provided by ICF to provide a comprehensive national analysis of methane abatement opportunities and their associated costs across the natural gas, oil, and coal supply chains. Results are presented as a suite of marginal abatement cost curves (MACCs), which depict the total potential and cost of reducing emissions through different abatement measures. We report results by sector (natural gas, oil, and coal) and by supply chain segment - production, gathering and boosting, processing, transmission and storage, or distribution - to facilitate identification of which sectors and supply chain

  3. Save water to save carbon and money: developing abatement costs for expanded greenhouse gas reduction portfolios.

    PubMed

    Stokes, Jennifer R; Hendrickson, Thomas P; Horvath, Arpad

    2014-12-01

    The water-energy nexus is of growing interest for researchers and policy makers because the two critical resources are interdependent. Their provision and consumption contribute to climate change through the release of greenhouse gases (GHGs). This research considers the potential for conserving both energy and water resources by measuring the life-cycle economic efficiency of greenhouse gas reductions through the water loss control technologies of pressure management and leak management. These costs are compared to other GHG abatement technologies: lighting, building insulation, electricity generation, and passenger transportation. Each cost is calculated using a bottom-up approach where regional and temporal variations for three different California water utilities are applied to all alternatives. The costs and abatement potential for each technology are displayed on an environmental abatement cost curve. The results reveal that water loss control can reduce GHGs at lower cost than other technologies and well below California's expected carbon trading price floor. One utility with an energy-intensive water supply could abate 135,000 Mg of GHGs between 2014 and 2035 and save--rather than spend--more than $130/Mg using the water loss control strategies evaluated. Water loss control technologies therefore should be considered in GHG abatement portfolios for utilities and policy makers. PMID:25369123

  4. Essays on carbon abatement and electricity markets

    NASA Astrophysics Data System (ADS)

    Taber, John Timothy

    In the first chapter of this dissertation, I study the effects of a number of policies which affect the electric grid using the SuperOPF, a full AC optimization/simulation framework with optimal investment developed at Cornell University. A 36-node model of the Northeast Power Coordinating Council is used to test policies that aim to reduce CO2, other emissions, or otherwise impact the operation of the electric grid: a base case, with no new environmental legislation; enactment of the Kerry-Lieberman CO2 allowance proposal in 2012; following Fukishima, a retirement of all US nuclear plants by 2022 with and without Kerry-Lieberman; marginal damages from SO2 and NOX emissions charged to coal, gas and oil-fired generation; plug-in hybrid electric vehicle load filling; wind incentives in place; and two cases which combine these. The cases suggest that alternative policies may have very different outcomes in terms of electricity prices, emissions, and health outcomes. In all cases, however, the optimal strategy for future investment is investment in new natural gas combined cycle plants. Policies can change how much new generation is built, whether other plants are built, or what types of plants are retired. The second chapter of my dissertation utilizes the SuperOPF and the model of the Northeast Power Coordinating Council to analyze the issue of carbon leakage. I analyze the effects of a regionally-limited carbon cap and trade program, the Regional Greenhouse Initiative (RGGI), when additional generating assets in non-affected states are included in the analysis. In the face of different carbon prices on generating assets in covered and non-covered states, generation is expected to shift from states bound by RGGI to states outside of RGGI. This carbon leakage may undermine some or all of the benefits of RGGI while simultaneously increasing prices for customers in the area. Even though carbon prices under RGGI are very low, some leakage is occurring, and this leakage

  5. Perverse effects of carbon markets on HFC-23 and SF6 abatement projects in Russia

    NASA Astrophysics Data System (ADS)

    Schneider, Lambert; Kollmuss, Anja

    2015-12-01

    Carbon markets are considered a key policy tool to achieve cost-effective climate mitigation. Project-based carbon market mechanisms allow private sector entities to earn tradable emissions reduction credits from mitigation projects. The environmental integrity of project-based mechanisms has been subject to controversial debate and extensive research, in particular for projects abating industrial waste gases with a high global warming potential (GWP). For such projects, revenues from credits can significantly exceed abatement costs, creating perverse incentives to increase production or generation of waste gases as a means to increase credit revenues from waste gas abatement. Here we show that all projects abating HFC-23 and SF6 under the Kyoto Protocol’s Joint Implementation mechanism in Russia increased waste gas generation to unprecedented levels once they could generate credits from producing more waste gas. Our results suggest that perverse incentives can substantially undermine the environmental integrity of project-based mechanisms and that adequate regulatory oversight is crucial. Our findings are critical for mechanisms in both national jurisdictions and under international agreements.

  6. Achieving CO2 reductions in Colombia: Effects of carbon taxes and abatement targets

    SciTech Connect

    Calderón, Silvia; Alvarez, Andres Camilo; Loboguerrero, Ana Maria; Arango, Santiago; Calvin, Katherine; Kober, Tom; Daenzer, Kathryn; Fisher-Vanden, Karen

    2015-06-03

    In this paper we investigate CO2 emission scenarios for Colombia and the effects of implementing carbon taxes and abatement targets on the energy system. By comparing baseline and policy scenario results from two integrated assessment partial equilibrium models TIAM-ECN and GCAM and two general equilibrium models Phoenix and MEG4C, we provide an indication of future developments and dynamics in the Colombian energy system. Currently, the carbon intensity of the energy system in Colombia is low compared to other countries in Latin America. However, this trend may change given the projected rapid growth of the economy and the potential increase in the use of carbon-based technologies. Climate policy in Colombia is under development and has yet to consider economic instruments such as taxes and abatement targets. This paper shows how taxes or abatement targets can achieve significant CO2 reductions in Colombia. Though abatement may be achieved through different pathways, taxes and targets promote the entry of cleaner energy sources into the market and reduce final energy demand through energy efficiency improvements and other demand-side responses. The electric power sector plays an important role in achieving CO2 emission reductions in Colombia, through the increase of hydropower, the introduction of wind technologies, and the deployment of biomass, coal and natural gas with CO2 capture and storage (CCS). Uncertainty over the prevailing mitigation pathway reinforces the importance of climate policy to guide sectors toward low-carbon technologies. This paper also assesses the economy-wide implications of mitigation policies such as potential losses in GDP and consumption. As a result, an assessment of the legal, institutional, social and environmental barriers to economy-wide mitigation policies is critical yet beyond the scope of this paper.

  7. Achieving CO2 reductions in Colombia: Effects of carbon taxes and abatement targets

    DOE PAGESBeta

    Calderón, Silvia; Alvarez, Andres Camilo; Loboguerrero, Ana Maria; Arango, Santiago; Calvin, Katherine; Kober, Tom; Daenzer, Kathryn; Fisher-Vanden, Karen

    2015-06-03

    In this paper we investigate CO2 emission scenarios for Colombia and the effects of implementing carbon taxes and abatement targets on the energy system. By comparing baseline and policy scenario results from two integrated assessment partial equilibrium models TIAM-ECN and GCAM and two general equilibrium models Phoenix and MEG4C, we provide an indication of future developments and dynamics in the Colombian energy system. Currently, the carbon intensity of the energy system in Colombia is low compared to other countries in Latin America. However, this trend may change given the projected rapid growth of the economy and the potential increase inmore » the use of carbon-based technologies. Climate policy in Colombia is under development and has yet to consider economic instruments such as taxes and abatement targets. This paper shows how taxes or abatement targets can achieve significant CO2 reductions in Colombia. Though abatement may be achieved through different pathways, taxes and targets promote the entry of cleaner energy sources into the market and reduce final energy demand through energy efficiency improvements and other demand-side responses. The electric power sector plays an important role in achieving CO2 emission reductions in Colombia, through the increase of hydropower, the introduction of wind technologies, and the deployment of biomass, coal and natural gas with CO2 capture and storage (CCS). Uncertainty over the prevailing mitigation pathway reinforces the importance of climate policy to guide sectors toward low-carbon technologies. This paper also assesses the economy-wide implications of mitigation policies such as potential losses in GDP and consumption. As a result, an assessment of the legal, institutional, social and environmental barriers to economy-wide mitigation policies is critical yet beyond the scope of this paper.« less

  8. Microbial Sulfate Reduction and Its Potential Utility as an Acid Mine Water Pollution Abatement Procedure

    PubMed Central

    Tuttle, Jon H.; Dugan, Patrick R.; Randles, Chester I.

    1969-01-01

    The presence of high concentrations of sulfate, iron, and hydrogen (acid) ions in drainage from coal mines and other areas containing waste pyritic materials is a serious water pollution problem. Sulfate can be removed from solution by microbial reduction to sulfide and subsequent precipitation as FeS. A mixed culture of microorganisms degraded wood dust cellulose, and the degradation products served as carbon and energy sources for sulfate-reducing bacteria. Metabolism of carbon compounds resulted in a net pH increase in the system. Oxidation-reduction potential (Eh) and temperature and carbon supplements were studied in an effort to accelerate the sulfate reduction process, with the ultimate objective of utilizing the process as a pollution abatement procedure. PMID:5775914

  9. Irreversible membrane fouling abatement through pre-deposited layer of hierarchical porous carbons.

    PubMed

    Hamad, Juma Z; Dua, Rubal; Kurniasari, Novita; Kennedy, Maria D; Wang, Peng; Amy, Gary L

    2014-11-15

    In this work, dual-templated hierarchical porous carbons (HPCs), produced from a coupled ice-hard templating approach, are shown to be a highly effective solution to the commonly occurring problem of irreversible fouling of low-pressure membranes used for pre-treatment in wastewater reuse. For the first time, dual-templated HPCs, along with their respective counterparts - single-templated meso-porous carbon (MPCs) (without macropores) - are tested in terms of their fouling reduction capacity and ability to remove different effluent organic matter fractions present in wastewater and compared with a commercially available powdered activated carbon (PAC). The synthesized HPCs provided exceptional fouling abatement, a 4-fold higher fouling reduction as compared to the previously reported best performing commercial PAC and ∼2.5-fold better fouling reduction than their respective mesoporous counterpart. Thus, it is shown that not only mesoporosity, but macroporosity is also necessary to achieve high fouling reduction, thus emphasizing the need for dual templating. In the case of HPCs, the pre-deposition technique is also found to outperform the traditional sorbent-feed mixing approach, mainly in terms of removal of fouling components. Based on their superior performance, a high permeability (ultra-low-pressure) membrane consisting of the synthesized HPC pre-deposited on a large pore size membrane support (0.45 μm membrane), is shown to give excellent pre-treatment performance for wastewater reuse application. PMID:25128660

  10. Carbon Abatement and Emissions Associated with the Gasification of Walnut Shells for Bioenergy and Biochar Production

    PubMed Central

    Pujol Pereira, Engil Isadora; Suddick, Emma C.; Six, Johan

    2016-01-01

    By converting biomass residue to biochar, we could generate power cleanly and sequester carbon resulting in overall greenhouse gas emissions (GHG) savings when compared to typical fossil fuel usage and waste disposal. We estimated the carbon dioxide (CO2) abatements and emissions associated to the concurrent production of bioenergy and biochar through biomass gasification in an organic walnut farm and processing facility in California, USA. We accounted for (i) avoided-CO2 emissions from displaced grid electricity by bioenergy; (ii) CO2 emissions from farm machinery used for soil amendment of biochar; (iii) CO2 sequestered in the soil through stable biochar-C; and (iv) direct CO2 and nitrous oxide (N2O) emissions from soil. The objective of these assessments was to pinpoint where the largest C offsets can be expected in the bioenergy-biochar chain. We found that energy production from gasification resulted in 91.8% of total C offsets, followed by stable biochar-C (8.2% of total C sinks), offsetting a total of 107.7 kg CO2-C eq Mg-1 feedstock. At the field scale, we monitored gas fluxes from soils for 29 months (180 individual observations) following field management and precipitation events in addition to weekly measurements within three growing seasons and two tree dormancy periods. We compared four treatments: control, biochar, compost, and biochar combined with compost. Biochar alone or in combination with compost did not alter total N2O and CO2 emissions from soils, indicating that under the conditions of this study, biochar-prompted C offsets may not be expected from the mitigation of direct soil GHG emissions. However, this study revealed a case where a large environmental benefit was given by the waste-to-bioenergy treatment, addressing farm level challenges such as waste management, renewable energy generation, and C sequestration. PMID:26963623

  11. Carbon Abatement and Emissions Associated with the Gasification of Walnut Shells for Bioenergy and Biochar Production.

    PubMed

    Pujol Pereira, Engil Isadora; Suddick, Emma C; Six, Johan

    2016-01-01

    By converting biomass residue to biochar, we could generate power cleanly and sequester carbon resulting in overall greenhouse gas emissions (GHG) savings when compared to typical fossil fuel usage and waste disposal. We estimated the carbon dioxide (CO2) abatements and emissions associated to the concurrent production of bioenergy and biochar through biomass gasification in an organic walnut farm and processing facility in California, USA. We accounted for (i) avoided-CO2 emissions from displaced grid electricity by bioenergy; (ii) CO2 emissions from farm machinery used for soil amendment of biochar; (iii) CO2 sequestered in the soil through stable biochar-C; and (iv) direct CO2 and nitrous oxide (N2O) emissions from soil. The objective of these assessments was to pinpoint where the largest C offsets can be expected in the bioenergy-biochar chain. We found that energy production from gasification resulted in 91.8% of total C offsets, followed by stable biochar-C (8.2% of total C sinks), offsetting a total of 107.7 kg CO2-C eq Mg-1 feedstock. At the field scale, we monitored gas fluxes from soils for 29 months (180 individual observations) following field management and precipitation events in addition to weekly measurements within three growing seasons and two tree dormancy periods. We compared four treatments: control, biochar, compost, and biochar combined with compost. Biochar alone or in combination with compost did not alter total N2O and CO2 emissions from soils, indicating that under the conditions of this study, biochar-prompted C offsets may not be expected from the mitigation of direct soil GHG emissions. However, this study revealed a case where a large environmental benefit was given by the waste-to-bioenergy treatment, addressing farm level challenges such as waste management, renewable energy generation, and C sequestration. PMID:26963623

  12. THE CO2 ABATEMENT POTENTIAL OF CALIFORNIA'S MID-SIZED COMMERCIAL BUILDINGS

    SciTech Connect

    Stadler, Michael; Marnay, Chris; Cardoso, Goncalo; Lipman, Tim; Megel, Olivier; Ganguly, Srirupa; Siddiqui, Afzal; Lai, Judy

    2009-12-31

    stimulating CHP deployment, while the SGIP buy down is more powerful. The attractiveness of CHP varies widely by climate zone and service territory, but in general, hotter inlandareas and San Diego are the more attractive regions because high cooling loads achieve higher equipment utilization. Additionally, large office buildings are surprisingly good hosts for CHP, so large office buildings in San Diego and hotter urban centers emerge as promising target hosts. Overall the effect on CO2 emissions is limited, never exceeding 27 percent of the CARB target. Nonetheless, results suggest that the CO2 emissions abatement potential of CHP in mid-sized CA buildings is significant, and much more promising than is typically assumed.

  13. Coupled Climate-Economy-Biosphere (CoCEB) model - Part 1: Abatement share and investment in low-carbon technologies

    NASA Astrophysics Data System (ADS)

    Ogutu, K. B. Z.; D'Andrea, F.; Ghil, M.; Nyandwi, C.; Manene, M. M.; Muthama, J. N.

    2015-04-01

    The Coupled Climate-Economy-Biosphere (CoCEB) model described herein takes an integrated assessment approach to simulating global change. By using an endogenous economic growth module with physical and human capital accumulation, this paper considers the sustainability of economic growth, as economic activity intensifies greenhouse gas emissions that in turn cause economic damage due to climate change. Different types of fossil fuels and different technologies produce different volumes of carbon dioxide in combustion. The shares of different fuels and their future evolution are not known. We assume that the dynamics of hydrocarbon-based energy share and their replacement with renewable energy sources in the global energy balance can be modeled into the 21st century by use of logistic functions. Various climate change mitigation policy measures are considered. While many integrated assessment models treat abatement costs merely as an unproductive loss of income, we consider abatement activities also as an investment in overall energy efficiency of the economy and decrease of overall carbon intensity of the energy system. The paper shows that these efforts help to reduce the volume of industrial carbon dioxide emissions, lower temperature deviations, and lead to positive effects in economic growth.

  14. The cost effectiveness of a policy to store carbon in Australian agricultural soils to abate greenhouse gas emissions

    NASA Astrophysics Data System (ADS)

    White, Robert E.; Davidson, Brian

    2015-07-01

    Data for cropping and pastoral enterprises in south eastern Australia were used in a cost-effectiveness analysis to assess the feasibility of abating greenhouse gas (GHG) emissions through storing soil carbon (C) as soil organic matter under the Australian government's Carbon Farming Initiative. We used the C credit value for 2013-14 of 24.15 per tonne of CO2- equivalent (CO2-e) and a C storage rate of 0.5 tonne C/hectare/year for conversion of cropland to pasture. Given that a change of enterprise is driven primarily by farmer returns, we found that none of the changes were feasible at current prices, with the exception of wheat to cattle or sheep in an irrigated system, and dryland cotton to cattle or sheep. Given that our model scenario assumed the most favourable economic factors, it is unlikely that increased soil C storage through a change from cropping to pasture can make a significant contribution to abating Australia's CO2 emissions. However, of greater concern to society is the methane emissions from grazing cattle or sheep, which would negate any gain in soil C under pasture, except for a switch from dryland cropping to sheep.

  15. Exploring the potential of fungi for methane abatement: Performance evaluation of a fungal-bacterial biofilter.

    PubMed

    Lebrero, Raquel; López, Juan Carlos; Lehtinen, Iiro; Pérez, Rebeca; Quijano, Guillermo; Muñoz, Raúl

    2016-02-01

    Despite several fungal strains have been retrieved from methane-containing environments, the actual capacity and role of fungi on methane abatement is still unclear. The batch biodegradation tests here performed demonstrated the capacity of Graphium sp. to co-metabolically biodegrade methane and methanol. Moreover, the performance and microbiology of a fungal-bacterial compost biofilter treating methane at concentrations of ∼2% was evaluated at empty bed residence times of 40 and 20 min under different irrigation rates. The daily addition of 200 mL of mineral medium resulted in elimination capacities of 36.6 ± 0.7 g m(-3) h(-1) and removal efficiencies of ≈90% at the lowest residence time. The indigenous fungal community of the compost was predominant in the final microbial population and outcompeted the inoculated Graphium sp. during biofilter operation. PMID:26347931

  16. Simulation of the GHG Abatement Potentials in the U.S. Building Sector by 2050

    SciTech Connect

    Stadler, Michael; DeForest, Nicholas; Marnay, Chris; Bonnet, Florence; Lai, Judy; Phan, Trucy

    2010-10-01

    various USDOE research funding scenarios on the adoption of these and other building energy technologies. The results demonstrate that passive technologies contain significant potential for carbon reductions - exceeding 1165 Mt cumulative savings between 2005 and 2050 (with 50% likelihood) and outperforming similar R&D funding programs for distributed photovoltaics and high efficiency solid-state lighting.

  17. Noise Abatement

    NASA Technical Reports Server (NTRS)

    1983-01-01

    SMART, Sound Modification and Regulated Temperature compound, is a liquid plastic mixture with exceptional energy and sound absorbing qualities. It is derived from a very elastic plastic which was an effective noise abatement material in the Apollo Guidance System. Discovered by a NASA employee, it is marketed by Environmental Health Systems, Inc. (EHS). The product has been successfully employed by a diaper company with noisy dryers and a sugar company with noisy blowers. The company also manufactures an audiometric test booth and acoustical office partitions.

  18. POTENTIAL ABATEMENT PRODUCTION AND MARKETING OF BYPRODUCT SULFURIC ACID IN THE U.S

    EPA Science Inventory

    The report gives results of an evaluation of the market potential for sulfur and sulfuric acid byproducts of combustion in power plant boilers. (Air quality regulations require control of SOx emissions from power plant boilers. Recovery of sulfur in useful form would avoid waste ...

  19. Broadening the Appeal of Marginal Abatement Cost Curves: Capturing Both Carbon Mitigation and Development Benefits of Clean Energy Technologies; Preprint

    SciTech Connect

    Cowlin, S.; Cochran, J.; Cox, S.; Davison, C.; van der Gaast, Y.

    2012-08-01

    Low emission development strategies (LEDS) articulate policies and implementation plans that enable countries to advance sustainable, climate-resilient development and private sector growth while significantly reducing the greenhouse gas (GHG) emissions traditionally associated with economic growth. In creating a LEDS, policy makers often have access to information on abatement potential and costs for clean energy technologies, but there is a scarcity of economy-wide approaches for evaluating and presenting information on other dimensions of importance to development, such as human welfare, poverty alleviation, and energy security. To address this shortcoming, this paper proposes a new tool for communicating development benefits to policy makers as part of a LEDS process. The purpose of this tool is two-fold: 1. Communicate development benefits associated with each clean energy-related intervention; 2. Facilitate decision-making on which combination of interventions best contributes to development goals. To pilot this tool, the authors created a visual using data on developmental impacts identified through the Technology Needs Assessment (TNA) project in Montenegro. The visual will then be revised to reflect new data established through the TNA that provides information on cost, GHG mitigation, as well as the range and magnitude of developmental impacts.

  20. Nitrous oxide abatement potential from the wastewater sector and the monetary value of the emissions credits

    NASA Astrophysics Data System (ADS)

    Wang, J. S.; Hamburg, S. P.; Pryor, D.

    2009-12-01

    As an illustration of the monetary opportunities afforded by greenhouse gas emissions markets, we estimated the potential value of greenhouse gas credits generated in the wastewater sector by switching from secondary to tertiary treatment. Our methodology for estimating emissions is a modification of that used by the Environmental Protection Agency for the U.S. greenhouse gas inventories. Focusing on N2O, we found that tertiary treatment in some situations will result in a net decrease in emissions, though the full range of reported emission factors for treatment plants and effluent in receiving waters could result in a net increase as well. Implementation of tertiary treatment across the U.S. could reduce emissions by up to 800,000 tonnes of N2O per year, generating greenhouse gas emissions credits worth up to 10 billion per year (assuming a market price of 10-40/tonne CO2 equivalents). In practice, it will be important to account for potential increases in CO2 emissions associated with the additional power consumption and chemical use required by tertiary treatment that would reduce the net climatic benefit. The net credits would reduce the cost of operating and maintaining tertiary treatment plants and provide an incentive for managers to optimize operating conditions for N2O reductions, a critical benefit of raising awareness of the link between tertiary treatment and N2O emissions. We outline a strategy for minimizing the uncertainty in quantifying N2O reductions in the hopes of accelerating implementation of a N2O crediting system for tertiary wastewater treatment plants.

  1. Changes in the use and management of forests for abating carbon emissions: issues and challenges under the Kyoto Protocol.

    PubMed

    Brown, Sandra; Swingland, Ian R; Hanbury-Tenison, Robin; Prance, Ghillean T; Myers, Norman

    2002-08-15

    The global carbon cycle is significantly influenced by changes in the use and management of forests and agriculture. Humans have the potential through changes in land use and management to alter the magnitude of forest-carbon stocks and the direction of forest-carbon fluxes. However, controversy over the use of biological means to absorb or reduce emissions of CO(2) (often referred to as carbon 'sinks') has arisen in the context of the Kyoto Protocol. The controversy is based primarily on two arguments: sinks may allow developed nations to delay or avoid actions to reduce fossil fuel emissions, and the technical and operational difficulties are too threatening to the successful implementation of land use and forestry projects for providing carbon offsets. Here we discuss the importance of including carbon sinks in efforts to address global warming and the consequent additional social, environmental and economic benefits to host countries. Activities in tropical forest lands provide the lowest cost methods both of reducing emissions and reducing atmospheric concentrations of greenhouse gases. We conclude that the various objections raised as to the inclusion of carbon sinks to ameliorate climate change can be addressed by existing techniques and technology. Carbon sinks provide a practical available method of achieving meaningful reductions in atmospheric concentrations of carbon dioxide while at the same time contribute to national sustainable development goals. PMID:12460486

  2. [Carbon capture and storage (CCS) and its potential role to mitigate carbon emission in China].

    PubMed

    Chen, Wen-Ying; Wu, Zong-Xin; Wang, Wei-Zhong

    2007-06-01

    Carbon capture and storage (CCS) has been widely recognized as one of the options to mitigate carbon emission to eventually stabilize carbon dioxide concentration in the atmosphere. Three parts of CCS, which are carbon capture, transport, and storage are assessed in this paper, covering comparisons of techno-economic parameters for different carbon capture technologies, comparisons of storage mechanism, capacity and cost for various storage formations, and etc. In addition, the role of CCS to mitigate global carbon emission is introduced. Finally, China MARKAL model is updated to include various CCS technologies, especially indirect coal liquefaction and poly-generation technologies with CCS, in order to consider carbon emission reduction as well as energy security issue. The model is used to generate different scenarios to study potential role of CCS to mitigate carbon emissions by 2050 in China. It is concluded that application of CCS can decrease marginal abatement cost and the decrease rate can reach 45% for the emission reduction rate of 50%, and it can lessen the dependence on nuclear power development for stringent carbon constrains. Moreover, coal resources can be cleanly used for longer time with CCS, e.g., for the scenario C70, coal share in the primary energy consumption by 2050 will increase from 10% when without CCS to 30% when with CCS. Therefore, China should pay attention to CCS R&D activities and to developing demonstration projects. PMID:17674718

  3. Insect abatement system

    NASA Technical Reports Server (NTRS)

    Spiro, Clifford Lawrence (Inventor); Burnell, Timothy Brydon (Inventor); Wengrovius, Jeffrey Hayward (Inventor)

    1997-01-01

    An insect abatement system prevents adhesion of insect debris to surfaces which must be kept substantially free of insect debris. An article is coated with an insect abatement coating comprising polyorganosiloxane with a Shore A hardness of less than 50 and a tensile strength of less than 4 MPa. A method for preventing the adhesion of insect debris to surfaces includes the step of applying an insect abatement coating to a surface which must be kept substantially free of insect debris.

  4. Photochemical roles of rapid economic growth and potential abatement strategies on tropospheric ozone over South and East Asia in 2030

    NASA Astrophysics Data System (ADS)

    Chatani, S.; Amann, M.; Goel, A.; Hao, J.; Klimont, Z.; Kumar, A.; Mishra, A.; Sharma, S.; Wang, S. X.; Wang, Y. X.; Zhao, B.

    2014-04-01

    A regional air quality simulation framework including the Weather Research and Forecasting modelling system (WRF), the Community Multi-scale Air Quality modeling system (CMAQ), and precursor emissions to simulate tropospheric ozone over South and East Asia is introduced. Concentrations of tropospheric ozone and related species simulated by the framework are validated by comparing with observation data of surface monitorings, ozone zondes, and satellites obtained in 2010. The simulation demonstrates acceptable performance on tropospheric ozone over South and East Asia at regional scale. Future energy consumption, carbon dioxide (CO2), nitrogen oxides (NOx), and volatile organic compound (VOC) emissions in 2030 under three future scenarios are estimated. One of the scenarios assumes a business-as-usual (BAU) pathway, and other two scenarios consider implementation of additional energy and environmental strategies to reduce energy consumption, CO2, NOx, and VOC emissions in China and India. Future surface ozone under these three scenarios is predicted by the simulation. The simulation indicates future surface ozone significantly increases around India for a whole year and around north eastern China in summer. NOx is a main driver on significant seasonal increase of surface ozone, whereas VOC as well as increasing background ozone and methane is also an important factor on annual average of surface ozone in East Asia. Warmer weather around India is also preferable for significant increase of surface ozone. Additional energy and environmental strategies assumed in future scenarios are expected to be effective to reduce future surface ozone over South and East Asia.

  5. Photochemical roles of rapid economic growth and potential abatement strategies on tropospheric ozone over South and East Asia in 2030

    NASA Astrophysics Data System (ADS)

    Chatani, S.; Amann, M.; Goel, A.; Hao, J.; Klimont, Z.; Kumar, A.; Mishra, A.; Sharma, S.; Wang, S. X.; Wang, Y. X.; Zhao, B.

    2014-09-01

    A regional air quality simulation framework including the Weather Research and Forecasting modeling system (WRF), the Community Multi-scale Air Quality modeling system (CMAQ), and precursor emissions to simulate tropospheric ozone over South and East Asia is introduced. Concentrations of tropospheric ozone and related species simulated by the framework are validated by comparing with observation data of surface monitoring, ozonesondes, and satellites obtained in 2010. The simulation demonstrates acceptable performance on tropospheric ozone over South and East Asia at regional scale. Future energy consumption, carbon dioxide (CO2), nitrogen oxides (NOx), and volatile organic compound (VOC) emissions in 2030 under three future scenarios are estimated. One of the scenarios assumes a business-as-usual (BAU) pathway, and other two scenarios consider implementation of additional energy and environmental strategies to reduce energy consumption, CO2, NOx, and VOC emissions in China and India. Future surface ozone under these three scenarios is predicted by the simulation. The simulation indicates future surface ozone significantly increases around India for a whole year and around northeastern China in summer. NOx is a main driver on significant seasonal increase of surface ozone, whereas VOC as well as increasing background ozone and methane is also an important factor on annual average of surface ozone in East Asia. Warmer weather around India is also preferable for significant increase of surface ozone. Additional energy and environmental strategies assumed in future scenarios are expected to be effective to reduce future surface ozone over South and East Asia.

  6. Shifts in the recent distribution of energy intake among U.S. children aged 2-18 years reflect potential abatement of earlier declining trends.

    PubMed

    Mendez, Michelle A; Sotres-Alvarez, Daniela; Miles, Donna R; Slining, Meghan M; Popkin, Barry M

    2014-08-01

    Recent national surveys suggest that child obesity in the United States may have reached a plateau, but corresponding trends in energy intake have not been examined in depth. This article evaluates medium-term trends in children's reported energy intake by using 4 waves of national dietary surveillance from 2003-2004 to 2009-2010. The analysis uses up to 2 24-h dietary recalls, incorporating methods that address challenges in estimating usual intake, accounting for intraindividual variance and covariates such as the presence of atypical consumption days. Quantile regression was used to assess disparities in intake among sociodemographic subgroups at extremes of the distribution as well as at the median, and the potential influence of misreporting was evaluated. Results indicated that after an initial decline in intakes across all age groups through 2007-2008, there were significant increases of ∼90 kcal/d at the median among adolescents in 2009-2010, whereas intakes in younger children remained steady. Among adolescent boys, the recent increase was larger at the 90th percentile than at the median. Intake trends did not vary by race/ethnic group, among whom intakes were similar at the upper end of the distribution. Misreporting did not influence trends over time, but intakes were lower in younger children and higher in older children after excluding misreporters. Overall, findings suggest that declines in children's energy intake from 2003-2004 through 2007-2008 were consistent with the obesity plateau observed in most age and gender subgroups through 2009-2010. However, there is evidence of increased intakes among adolescents in 2009-2010, which may threaten the earlier abatement in overweight in this older age group. PMID:24919689

  7. Comparing primary energy attributed to renewable energy with primary energy equivalent to determine carbon abatement in a national context.

    PubMed

    Gallachóir, Brian P O; O'Leary, Fergal; Bazilian, Morgan; Howley, Martin; McKeogh, Eamon J

    2006-01-01

    The current conventional approach to determining the primary energy associated with non-combustible renewable energy (RE) sources such as wind energy and hydro power is to equate the electricity generated from these sources with the primary energy supply. This paper compares this with an approach that was formerly used by the IEA, in which the primary energy equivalent attributed to renewable energy was equated with the fossil fuel energy it displaces. Difficulties with implementing this approach in a meaningful way for international comparisons lead to most international organisations abandoning the primary energy equivalent methodology. It has recently re-emerged in prominence however, as efforts grow to develop baseline procedures for quantifying the greenhouse gas (GHG) emissions avoided by renewable energy within the context of the Kyoto Protocol credit trading mechanisms. This paper discusses the primary energy equivalent approach and in particular the distinctions between displacing fossil fuel energy in existing plant or in new plant. The approach is then extended provide insight into future primary energy displacement by renewable energy and to quantify the amount of CO2 emissions avoided by renewable energy. The usefulness of this approach in quantifying the benefits of renewable energy is also discussed in an energy policy context, with regard to increasing security of energy supply as well as reducing energy-related GHG (and other) emissions. The approach is applied in a national context and Ireland is case study country selected for this research. The choice of Ireland is interesting in two respects. The first relates to the high proportion of electricity only fossil fuel plants in Ireland resulting in a significant variation between primary energy and primary energy equivalent. The second concerns Ireland's poor performance to date in limiting GHG emissions in line with its Kyoto target and points to the need for techniques to quantify the potential

  8. The Cost of Conserved Carbon: Weighing the Monetary, Social, and Climactic Implications of Regional-, National-, and Global-Scale Carbon Abatement Strategies

    NASA Astrophysics Data System (ADS)

    Kantner, J. W.; Hoffman, I.; Johnston, J. L.; Kammen, D. M.; Levin, J. E.; Komiyama, R.; Motschenbacher, A.; Gimon, E.

    2008-05-01

    Previous schema for analyzing carbon mitigation methods often have lacked realistic costs, comprehensive accounting of trade-offs, and methodological transparency. We offer a dynamic model for evaluating diverse carbon mitigation scenarios based on economics, policy traction, and interplay with climate, society and ecosystems. The model will test the impacts of policy changes across more than two dozen strategies for conserving or avoiding carbon emissions. Users will be able to access the model at rael-c3.berkeley.edu and change underlying assumptions as desired.

  9. Fly Ash Characteristics and Carbon Sequestration Potential

    SciTech Connect

    Palumbo, Anthony V.; Amonette, James E.; Tarver, Jana R.; Fagan, Lisa A.; McNeilly, Meghan S.; Daniels, William L.

    2007-07-20

    Concerns for the effects of global warming have lead to an interest in the potential for inexpensive methods to sequester carbon dioxide (CO2). One of the proposed methods is the sequestration of carbon in soil though the growth of crops or forests.4,6 If there is an economic value placed on sequestration of carbon dioxide in soil there may be an an opportunity and funding to utilize fly ash in the reclamation of mine soils and other degraded lands. However, concerns associated with the use of fly ash must be addressed before this practice can be widely adopted. There is a vast extent of degraded lands across the world that has some degree of potential for use in carbon sequestration. Degraded lands comprise nearly 2 X 109 ha of land throughout the world.7 Although the potential is obviously smaller in the United States, there are still approximately 4 X 106 ha of degraded lands that previously resulted from mining operations14 and an additional 1.4 X 108 ha of poorly managed lands. Thus, according to Lal and others the potential is to sequester approximately 11 Pg of carbon over the next 50 years.1,10 The realization of this potential will likely be dependent on economic incentives and the use of soil amendments such as fly ash. There are many potential benefits documented for the use of fly ash as a soil amendment. For example, fly ash has been shown to increase porosity, water-holding capacity, pH, conductivity, and dissolved SO42-, CO32-, HCO3-, Cl- and basic cations, although some effects are notably decreased in high-clay soils.8,13,9 The potential is that these effects will promote increased growth of plants (either trees or grasses) and result in greater carbon accumulation in the soil than in untreated degraded soils. This paper addresses the potential for carbon sequestration in soils amended with fly ash and examines some of the issues that should be considered in planning this option. We describe retrospective studies of soil carbon accumulation on

  10. Impacts of Geological Variability on Carbon Storage Potential

    NASA Astrophysics Data System (ADS)

    Eccles, Jordan Kaelin

    The changes to the environment caused by anthropogenic climate change pose major challenges for energy production in the next century. Carbon Capture and Storage (CCS) is a group of technologies that would permit the continued use of carbon-intense fuels such as coal for energy production while avoiding further impact on the global climate system. The mechanism most often proposed for storage is injection of CO2 below the surface of the Earth in geological media, with the most promising option for CO2 reservoirs being deep saline aquifers (DSA's). Unlike oil and gas reservoirs, deep saline aquifers are poorly characterized and the variability in their properties is large enough to have a high impact on the overall physical and economic viability of CCS. Storage in saline aquifers is likely to be a very high-capacity resource, but its economic viability is almost unknown. We consider the impact of geological variability on the total viability of the CO 2 storage system from several perspectives. First, we examine the theoretical range of costs of storage by coupling a physical and economic model of CO 2 storage with a range of possible geological settings. With the relevant properties of rock extending over several orders of magnitude, it is not surprising that we find costs and storage potential ranging over several orders of magnitude. Second, we use georeferenced data to evaluate the spatial distribution of cost and capacity. When paired together to build a marginal abatement cost curve (MACC), this cost and capacity data indicates that low cost and high capacity are collocated; storage in these promising areas is likely to be quite viable but may not be available to all CO2 sources. However, when we continue to explore the impact of geological variability on realistic, commercial-scale site sizes by invoking capacity and pressure management constraints, we find that the distribution costs and footprints of these sites may be prohibitively high. The combination

  11. Noise Abatement Materials

    NASA Technical Reports Server (NTRS)

    1986-01-01

    A former NASA employee who discovered a kind of plastic that soaked up energy, dampened vibrations, and was a good noise abatement material, founded a company to market noise deadening adhesives, sheets, panels and enclosures. Known as SMART products, they are 75-80% lighter than ordinary soundproofing material and have demonstrated a high degree of effectiveness. The company, Varian Associates, makes enclosures for high voltage terminals and other electronic system components, and easily transportable audiometric test booths.

  12. Functionalized carbon nanotubes for potential medicinal applications

    PubMed Central

    Zhang, Yi; Bai, Yuhong; Yan, Bing

    2016-01-01

    Functionalized carbon nanotubes display unique properties that enable a variety of medicinal applications, including the diagnosis and treatment of cancer, infectious diseases and central nervous system disorders, and applications in tissue engineering. These potential applications are particularly encouraged by their ability to penetrate biological membranes and relatively low toxicity. PMID:20451656

  13. Hanford Site Asbestos Abatement Plan. Revision 1

    SciTech Connect

    Mewes, B.S.

    1993-09-01

    The Hanford Site Asbestos Abatement Plan (Plan) lists priorities for asbestos abatement activities to be conducted in Hanford Site facilities. The Plan is based on asbestos assessment information gathered in fiscal year 1989 that evaluated all Hanford Site facilities for the presence and condition of asbestos. Of those facilities evaluated, 414 contain asbestos-containing materials and are classified according to the potential risk of asbestos exposure to building personnel. The Plan requires that asbestos condition update reports be prepared for all affected facilities. The reporting is completed by the asbestos coordinator for each of the 414 affected facilities and transmitted to the Plan manager annually. The Plan manager uses this information to reprioritize future project lists. Currently, five facilities are determined to be Class Al, indicating a high potential for asbestos exposure. Class Al and B1 facilities are the highest priority for asbestos abatement. Abatement of the Class A1 and Bl facilities is scheduled through fiscal year 1997. Removal of asbestos in B1 facilities will reduce the risk for further Class ``A`` conditions to arise.

  14. Global forestry emission projections and abatement costs

    NASA Astrophysics Data System (ADS)

    Böttcher, H.; Gusti, M.; Mosnier, A.; Havlik, P.; Obersteiner, M.

    2012-04-01

    In this paper we present forestry emission projections and associated Marginal Abatement Cost Curves (MACCs) for individual countries, based on economic, social and policy drivers. The activities cover deforestation, afforestation, and forestry management. The global model tools G4M and GLOBIOM, developed at IIASA, are applied. GLOBIOM uses global scenarios of population, diet, GDP and energy demand to inform G4M about future land and commodity prices and demand for bioenergy and timber. G4M projects emissions from afforestation, deforestation and management of existing forests. Mitigation measures are simulated by introducing a carbon tax. Mitigation activities like reducing deforestation or enhancing afforestation are not independent of each other. In contrast to existing forestry mitigation cost curves the presented MACCs are not developed for individual activities but total forest land management which makes the estimated potentials more realistic. In the assumed baseline gross deforestation drops globally from about 12 Mha in 2005 to below 10 Mha after 2015 and reach 0.5 Mha in 2050. Afforestation rates remain fairly constant at about 7 Mha annually. Although we observe a net area increase of global forest area after 2015 net emissions from deforestation and afforestation are positive until 2045 as the newly afforested areas accumulate carbon rather slowly. About 200 Mt CO2 per year in 2030 in Annex1 countries could be mitigated at a carbon price of 50 USD. The potential for forest management improvement is very similar. Above 200 USD the potential is clearly constrained for both options. In Non-Annex1 countries avoided deforestation can achieve about 1200 Mt CO2 per year at a price of 50 USD. The potential is less constrained compared to the potential in Annex1 countries, achieving a potential of 1800 Mt CO2 annually in 2030 at a price of 1000 USD. The potential from additional afforestation is rather limited due to high baseline afforestation rates assumed

  15. Emission Abatement System

    DOEpatents

    Bromberg, Leslie; Cohn, Daniel R.; Rabinovich, Alexander

    2003-05-13

    Emission abatement system. The system includes a source of emissions and a catalyst for receiving the emissions. Suitable catalysts are absorber catalysts and selective catalytic reduction catalysts. A plasma fuel converter generates a reducing gas from a fuel source and is connected to deliver the reducing gas into contact with the absorber catalyst for regenerating the catalyst. A preferred reducing gas is a hydrogen rich gas and a preferred plasma fuel converter is a plasmatron. It is also preferred that the absorber catalyst be adapted for absorbing NO.sub.x.

  16. Biological abatement of cellulase inhibitors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bio-abatement uses a fungus to metabolize and remove fermentation inhibitors. To determine whether bio-abatement could alleviate enzyme inhibitor effects observed in biomass liquors after pretreatment, corn stover at 10% (w/v) solids was pretreated with either dilute acid or liquid hot water. The ...

  17. Everglades restoration could decrease carbon sink potential

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2013-01-01

    Starting more than a century ago and ramping up to a massive scale in the 1950s, canal building and drainage projects in the Florida Everglades steadily degraded the sprawling wetland ecosystem. In the coming years, a massive 30-year multibillion-dollar restoration program is set to naturalize the Florida Everglades, returning the drained land to a closer approximation of its original structure. Restoring the Everglades, however, will have consequent effects on wetland dynamics, as plants and soil processes adjust to the changing water levels. Using eddy covariance measurements of surface-atmosphere gas exchange, Jimenez et al. tracked the roles of two different types of Everglades wetlands in the regional carbon cycle. Based on their findings, the authors suggest that, contrary to previous research, restoring the Everglades will likely diminish the potential of the region to serve as a carbon sink.

  18. Estimating the financial risks of Andropogon gayanus to greenhouse gas abatement projects in northern Australia

    NASA Astrophysics Data System (ADS)

    Adams, Vanessa M.; Setterfield, Samantha A.

    2013-06-01

    Financial mechanisms such as offsets are one strategy to abate greenhouse gas emissions, and the carbon market is expanding with a growing demand for offset products. However, in the case of carbon offsets, if the carbon is released due to intentional or unintentional reversal through environmental events such as fire, the financial liability to replace lost offsets will likely fall on the provider. This liability may have implications for future participation in programmes, but common strategies such as buffer pool and insurance products can be used to minimize this liability. In order for these strategies to be effective, an understanding of the spatial and temporal distributions of expected reversals is needed. We use the case study of savanna burning, an approved greenhouse gas abatement methodology under the Carbon Farming Initiative in Australia, to examine potential risks to carbon markets in northern Australia and quantify the financial risks. We focus our analysis on the threat of Andropogon gayanus (gamba grass) to savanna burning due to its documented impacts of increased fuel loads and altered fire regimes. We assess the spatial and financial extent to which gamba grass poses a risk to savanna burning programmes in northern Australia. We find that 75% of the eligible area for savanna burning is spatially coincident with the high suitability range for gamba grass. Our analysis demonstrates that the presence of gamba grass seriously impacts the financial viability of savanna burning projects. For example, in order to recuperate the annual costs of controlling 1 ha of gamba grass infestation, 290 ha of land must be enrolled in annual carbon abatement credits. Our results show an immediate need to contain gamba grass to its current extent to avoid future spread into large expanses of land, which are currently profitable for savanna burning.

  19. Carbon Sequestration Potential of Agricultural Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Through proper management, agricultural systems (cropland, pasture, and forest) have the ability to remove carbon dioxide from the atmosphere and sequester it in soils and wood products. The carbon thus sequestered can help slow the increase in atmospheric carbon dioxide currently occurring as a res...

  20. Model curriculum for asbestos abatement workers

    SciTech Connect

    1993-12-31

    These slides are part of a 4-day-course intended for those persons seeking accreditation as asbestos abatement workers. The course presents a straight forward, easy-to-read approach to learning the basics of asbestos abatement.

  1. ASSESSMENT OF HOUSEHOLD CARBON FOOTPRINT REDUCTION POTENTIALS

    SciTech Connect

    Kramer, Klaas Jan; Homan, Greg; Brown, Rich; Worrell, Ernst; Masanet, Eric

    2009-04-15

    The term ?household carbon footprint? refers to the total annual carbon emissions associated with household consumption of energy, goods, and services. In this project, Lawrence Berkeley National Laboratory developed a carbon footprint modeling framework that characterizes the key underlying technologies and processes that contribute to household carbon footprints in California and the United States. The approach breaks down the carbon footprint by 35 different household fuel end uses and 32 different supply chain fuel end uses. This level of end use detail allows energy and policy analysts to better understand the underlying technologies and processes contributing to the carbon footprint of California households. The modeling framework was applied to estimate the annual home energy and supply chain carbon footprints of a prototypical California household. A preliminary assessment of parameter uncertainty associated with key model input data was also conducted. To illustrate the policy-relevance of this modeling framework, a case study was conducted that analyzed the achievable carbon footprint reductions associated with the adoption of energy efficient household and supply chain technologies.

  2. 23 CFR 772.11 - Noise abatement.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... OF HIGHWAY TRAFFIC NOISE AND CONSTRUCTION NOISE § 772.11 Noise abatement. (a) In determining and abating traffic noise impacts, primary consideration is to be given to exterior areas. Abatement will usually be necessary only where frequent human use occurs and a lowered noise level would be of...

  3. 23 CFR 772.11 - Noise abatement.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... OF HIGHWAY TRAFFIC NOISE AND CONSTRUCTION NOISE § 772.11 Noise abatement. (a) In determining and abating traffic noise impacts, primary consideration is to be given to exterior areas. Abatement will usually be necessary only where frequent human use occurs and a lowered noise level would be of...

  4. Lead Abatement Worker Skill Standards.

    ERIC Educational Resources Information Center

    Laborers-AGC Education and Training Fund, Pomfret Center, CT.

    This document identifies skill standards for lead abatement in a manner that is easy to understand, useful, and meaningful to workers, educators, trainers, labor leaders, contractors, and project owners. To meet the needs of the various users of this document who will have a different application of the standards and seek different information,…

  5. Asbestos Abatement--Practical Considerations.

    ERIC Educational Resources Information Center

    Sedrel, Roy A.

    Illinois Senate Bill 1644, the recently passed "Asbestos Abatement Act," requires all schools in the state, public and private alike, to remove friable asbestos by whichever comes first: July 1, 1989, or 3 years following the establishment of a system for state funding for corrective action. This document addresses practical considerations in…

  6. Biological abatement of enzyme inhibitors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lignocellulose pretreatments release phenolic compounds that cause enzyme inhibition and deactivation. Bio-abatement, the biological removal of furfurals, acetic acid and phenolics, may utilize fungal fermentation to metabolize these compounds to CO2, water, cell mass, and heat. Our work with Coni...

  7. Asbestos Abatement: Start to Finish.

    ERIC Educational Resources Information Center

    Makruski, Edward D.

    1984-01-01

    An EPA survey of the largest school districts in the nation revealed that over 50 percent have not inspected for asbestos and two-thirds have failed to notify parents adequately. Seven steps are therefore provided for successful asbestos abatement, in anticipation of tougher regulations now under consideration. (TE)

  8. An analytical bond-order potential for carbon.

    PubMed

    Zhou, X W; Ward, D K; Foster, M E

    2015-09-01

    Carbon is the most widely studied material today because it exhibits special properties not seen in any other materials when in nano dimensions such as nanotube and graphene. Reduction of material defects created during synthesis has become critical to realize the full potential of carbon structures. Molecular dynamics (MD) simulations, in principle, allow defect formation mechanisms to be studied with high fidelity, and can, therefore, help guide experiments for defect reduction. Such MD simulations must satisfy a set of stringent requirements. First, they must employ an interatomic potential formalism that is transferable to a variety of carbon structures. Second, the potential needs to be appropriately parameterized to capture the property trends of important carbon structures, in particular, diamond, graphite, graphene, and nanotubes. Most importantly, the potential must predict the crystalline growth of the correct phases during direct MD simulations of synthesis to achieve a predictive simulation of defect formation. Because an unlimited number of structures not included in the potential parameterization are encountered, the literature carbon potentials are often not sufficient for growth simulations. We have developed an analytical bond order potential for carbon, and have made it available through the public MD simulation package LAMMPS. We demonstrate that our potential reasonably captures the property trends of important carbon phases. Stringent MD simulations convincingly show that our potential accounts not only for the crystalline growth of graphene, graphite, and carbon nanotubes but also for the transformation of graphite to diamond at high pressure. PMID:26018402

  9. An analytical bond-order potential for carbon

    DOE PAGESBeta

    Zhou, Xiaowang; Ward, Donald K.; Foster, Michael E.

    2015-05-27

    Carbon is the most widely studied material today because it exhibits special properties not seen in any other materials when in nano dimensions such as nanotube and graphene. Reduction of material defects created during synthesis has become critical to realize the full potential of carbon structures. Molecular dynamics (MD) simulations, in principle, allow defect formation mechanisms to be studied with high fidelity, and can, therefore, help guide experiments for defect reduction. Such MD simulations must satisfy a set of stringent requirements. First, they must employ an interatomic potential formalism that is transferable to a variety of carbon structures. Second, themore » potential needs to be appropriately parameterized to capture the property trends of important carbon structures, in particular, diamond, graphite, graphene, and nanotubes. The potential must predict the crystalline growth of the correct phases during direct MD simulations of synthesis to achieve a predictive simulation of defect formation. An unlimited number of structures not included in the potential parameterization are encountered, thus the literature carbon potentials are often not sufficient for growth simulations. We have developed an analytical bond order potential for carbon, and have made it available through the public MD simulation package LAMMPS. We also demonstrate that our potential reasonably captures the property trends of important carbon phases. As a result, stringent MD simulations convincingly show that our potential accounts not only for the crystalline growth of graphene, graphite, and carbon nanotubes but also for the transformation of graphite to diamond at high pressure.« less

  10. An analytical bond-order potential for carbon

    SciTech Connect

    Zhou, Xiaowang; Ward, Donald K.; Foster, Michael E.

    2015-05-27

    Carbon is the most widely studied material today because it exhibits special properties not seen in any other materials when in nano dimensions such as nanotube and graphene. Reduction of material defects created during synthesis has become critical to realize the full potential of carbon structures. Molecular dynamics (MD) simulations, in principle, allow defect formation mechanisms to be studied with high fidelity, and can, therefore, help guide experiments for defect reduction. Such MD simulations must satisfy a set of stringent requirements. First, they must employ an interatomic potential formalism that is transferable to a variety of carbon structures. Second, the potential needs to be appropriately parameterized to capture the property trends of important carbon structures, in particular, diamond, graphite, graphene, and nanotubes. The potential must predict the crystalline growth of the correct phases during direct MD simulations of synthesis to achieve a predictive simulation of defect formation. An unlimited number of structures not included in the potential parameterization are encountered, thus the literature carbon potentials are often not sufficient for growth simulations. We have developed an analytical bond order potential for carbon, and have made it available through the public MD simulation package LAMMPS. We also demonstrate that our potential reasonably captures the property trends of important carbon phases. As a result, stringent MD simulations convincingly show that our potential accounts not only for the crystalline growth of graphene, graphite, and carbon nanotubes but also for the transformation of graphite to diamond at high pressure.

  11. Impact of Various Biochars on Greenhouse Gas Production Potentials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A potential abatement strategy to increasing atmospheric levels of carbon dioxide (CO2) is to sequester atmospheric CO2 into a more stable form through the use of pyrolysis. The biomass feed stock generates energy and a more stable carbon form (biochar) that then can be returned to the soil sequeste...

  12. Managing lead-based paint abatement wastes

    SciTech Connect

    Steele, N.L.C.

    1994-12-31

    Renovation, remodeling, demolition, and surface preparation for painting, in addition to specified lead abatement, are all activities that have the potential to produce hazardous wastes if a property was painted with lead-based paint. Lead-based paint was used on residential structures until 1978, when most residential uses were banned by the Consumer Products Safety Council. Prior to the 1950s, paints for residential uses may have contained up to 50% lead by weight. Today, commercial and military paints may still contain lead and can be used on non-residential structures. The lead content of residential paints is limited to 0.06% lead (by weight) in the dried film. This paper provides an overview of some of the information needed to properly manage lead-based paint abatement wastes. The issues covered in this paper include waste classification, generator status, treatment, and land disposal restrictions. The author assumes that the reader is familiar with the provision of the Health and Safety Code and the California Code of Regulations that pertain to generation and management of hazardous wastes. Citations provided herein do not constitute an exhaustive list of all the regulations with which a generator of hazardous waste must comply.

  13. Glovebags handle asbestos abatement

    SciTech Connect

    Ross, K.

    1997-12-01

    Regulations from OSHA mean that industry can use glovebags to perform many asbestos maintenance operations in less time, at less cost, and with less chance of personnel being exposed. The regulations became effective July 10, 1995, with some clarifications issued since that date. The standards allow glovebags to be used in maintenance operations or removal of asbestos from straight runs of pipe without any size limitations. They can also be used on elbows and other connections if the glovebags are designed for a particular configuration. The paper discusses potential savings, construction activities, procedures that must be followed when using glovebags, and training.

  14. Novel forms of carbon as potential anodes for lithium batteries

    SciTech Connect

    Winans, R.E.; Carrado, K.A.

    1994-06-01

    The objective of this study is to design and synthesize novel carbons as potential electrode materials for lithium rechargeable batteries. A synthetic approach which utilizes inorganic templates is described and initial characterization results are discussed. The templates also act as a catalyst enabling carbon formation at low temperatures. This synthetic approach should make it easier to control the surface and bulk characteristics of these carbons.

  15. New Potential Sources for Black Onaping Carbon

    NASA Technical Reports Server (NTRS)

    Bunch, T. E.; Becker, L.; Schultz, P. H.; Wolbach, W. S.

    1997-01-01

    One intriguing and important issue of the Sudbury Structure concerns the source of the relatively large amount of C in the Onaping Formation Black member. This dilemma was recently addressed, and the conclusion was reached that an impactor could not have delivered all of the requisite C. Becker et al. have suggested that much of the C came from the impactor and reported the presence of interstellar He "caged" inside some fullerenes that may have survived the impact. So, conceivably, the C inventory in the Sudbury Structure comes from both target and impactor materials, although the known target rocks have little C. We discuss here the possibility of two terrestrial sources for at least some of the C: (1) impact evaporation/dissociation of C from carbonate target rocks and (2) the presence of heretofore-unrecognized C-rich (up to 26 wt%) siliceous "shale," fragments, which are found in the upper, reworked Black member. Experimental: Hypervelocity impact of a 0.635-diameter Al projectile into dolomite at 5.03 km/s (performed at the Ames Research Center vertical gun range) produced a thin, black layer (= 0.05 mm thick) that partially lined the crater and coated impactor remnants. Scanning electronic microscope (SEM) imagery shows this layer to be spongelike on a submicron scale and Auger spectroscopic analyses yield: 33% C, 22% Mg, 19% 0, and 9% Al (from the projectile). Elemental mapping shows that all of the available 0 is combined with Ca and Mg, Al is not oxidized, and C is in elemental form. Dissociation efficiency of C from CO2 is estimated to be <10% of crater volume. Raman spectroscopy indicates that the C is highly disorganized graphite. Another impact experiment [4] also produced highly disordered graphite from a limestone target (reducing collector), in addition to small amounts of diamond/lonsdaleite/chaoite (oxidizing collector). These experiments confirm the reduction of C from carbonates in impact vapor plumes. Observational: SEM observations and

  16. Assessing carbon dynamics in semiarid ecosystems : Balancing potential gains with potential large rapid losses

    SciTech Connect

    Breshears, D. D.; Ebinger, M. H.; Unkefer, P. J.

    2001-01-01

    Photosynthesis and respiration are the largest fluxes into and out of the biosphere (Molles 1999). Consequently, small changes in these fluxes can potentially produce large changes in the storage of carbon in the biosphere. Terrestrial carbon fluxes account for more than half of the carbon transferred between the atmosphere and the earth's surface (about 120 GigaTons/year), and current stores of carbon in terrestrial ecosystem are estimated at 2060 GigaTons. Increasing attention is being focused on the role of managing and sequestering carbon in the terrestrial biosphere as a means for addressing global climate change (IGBP, 1998; U.S. Department of Energy, 1999). Terrestrial ecosystems are widely recognized as a major biological scrubber for atmosphereic CO{sub 2} and their ability to finction as such can be increased significantly over the next 25 years through careful manipulation. The potential for terrestrial carbon gains has been the subject of much attention (Dixon et al., 1994; Masera et al. 1997; Cao and Woodward, 1998; DeLucia et al. 1999). In contrast to other strategies for reducing net carbon emissions, terrestrial sequestration has the potential for rapid implementation. Strategies that focus on soil carbon are likely to be effective because in addition to being a storage pool of carbon, soil carbon also improves site productivity through improving soil quality (e.g., water retention and nutrient availability). The carbon pool in soils is immense and highly dynamic. The flux of carbon into and out of soils is one of the largest uncertainties in the total mass balance of global carbon (NRC, 1999; La1 et al., 1998; Cambardella, 1998). Reducing these uncertainties is key to developing carbon sequestration strategies. Soil carbon pools have been greatly depleted over recent centuries, and there is potential to increase storage of carbon in these soils through effective land management. Whereas carbon in vegetation can be managed directly through land use

  17. Carbon Sequestration Potential of a Switchgrass Bioenergy Crop

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Switchgrass is an important bioenergy crop with the potential to provide a reliable supply of renewable energy while also removing carbon dioxide from the atmosphere and sequestering it in the soil. We conducted a four-year study to quantify carbon dioxide sequestration during the establishment and ...

  18. Zeta Potential in Intact Natural Carbonates at Elevated Temperatures

    NASA Astrophysics Data System (ADS)

    Al-Mahrouqi, D.; Vinogradov, J.; Jackson, M.

    2015-12-01

    Measurements of zeta potential have been used to monitor subsurface flows in many natural brine systems. Numerous studies report zeta potentials in carbonates using crushed samples at low ionic strength and laboratory temperatures. However, natural brines have much higher salinity; moreover, temperatures are considerably higher in many subsurface settings. The variation of zeta potentials with temperature has not been examined in natural carbonates. We report zeta potential values interpreted from streaming potential measurements in two intact carbonate rock samples, saturated with artificial brines at elevated temperatures. We measure streaming potential using an experimental set-up that incorporates in-situ measurements of saturated rock conductivity, brine temperature, brine pH, brine electrical conductivity, pressure difference and voltage at temperatures up to 120oC. The streaming potential measurements are complemented with brine effluent studies. We find that the interpreted zeta potential is negative and decreases in magnitude with increasing temperature at low ionic strength (0.01M) and independent of temperature at high ionic strength (0.5M); consistent with published zeta potential in intact natural sandstones. The concentration of Ca2+ (main potential determining ion) also decreases with temperature at low ionic strength, but remains constant at high ionic strength. The temperature dependence of the zeta potential is consistent between two different natural carbonate samples and can be explained by the temperature dependence of pCa2+. We suggest that zeta potential of carbonate is independent of temperature or pH when pCa2+ remains constant. A linear variation of pH vs. pCa2+ is exhibited, at ambient and elevated temperatures, when pCa2+ is allowed to change with pH. This linear variation explains the numerous published data that shows apparent relationship between zeta potential of carbonates and pH.

  19. New Potential Sources for Black Onaping Carbon

    NASA Technical Reports Server (NTRS)

    Bunch, T. E.; Becker, L.; Schultz, P. H.; Wolbach, W. S.

    1997-01-01

    One intriguing and important issue of the Sudbury Structure concerns the source of the relatively large amount of C in the Onaping Formation Black member. This dilemma was recently addressed, and the conclusion was reached that an impactor could not have delivered all of the requisite C. Becker et al. have suggested that much of the C came from the impactor and reported the presence of interstellar He "caged" inside some fullerenes that may have survived the impact. So, conceivably, the C inventory in the Sudbury Structure comes from both target and impactor materials, although the known target rocks have little C. We discuss here the possibility of two terrestrial sources for at least some of the C: (1) impact evaporation/dissociation of C from carbonate target rocks and (2) the presence of heretofore-unrecognized C-rich (up to 26 wt%) siliceous "shale," fragments, which are found in the upper, reworked Black member. Experimental: Hypervelocity impact of a 0.635-diameter Al projectile into dolomite at 5.03 km/s (performed at the Ames Research Center vertical gun range) produced a thin, black layer (= 0.05 mm thick) that partially lined the crater and coated impactor remnants. Scanning electronic microscope (SEM) imagery shows this layer to be spongelike on a submicron scale and Auger spectroscopic analyses yield: 33% C, 22% Mg, 19% 0, and 9% Al (from the projectile). Elemental mapping shows that all of the available 0 is combined with Ca and Mg, Al is not oxidized, and C is in elemental form. Dissociation efficiency of C from CO2 is estimated to be <10% of crater volume. Raman spectroscopy indicates that the C is highly disorganized graphite. Another impact experiment [4] also produced highly disordered graphite from a limestone target (reducing collector), in addition to small amounts of diamond/lonsdaleite/chaoite (oxidizing collector). These experiments confirm the reduction of C from carbonates in impact vapor plumes. Observational: SEM observations and

  20. 76 FR 39368 - Migratory Bird Permits; Abatement Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-06

    ... abatement permit holder may use captive-bred raptors held under his or her migratory bird master falconry permit for abatement activities without transferring them to his or her abatement permit, provided the... used under his or her abatement permit. Raptors used under a Federal abatement permit must be...

  1. [Legal aspects of noise abatement].

    PubMed

    Kierski, W S

    1976-12-01

    Noise abatement is a problem of technology, medicine, law, and education. In the technical field, the problem of avoiding hazards is the primary one. In respect of encroachment upon neighbours mutual regard should be the foremost consideration. From the legal angle, a distinction is made between protection of the individial-above all under the provisions of the German Civil Code (Bürgerliches Gesetzbuch)-and of the community-under the provisions of criminal law and administrative law. Future legislation will have to concentrate increasingly upon governmental control measures especially with a view to prevention, instead of the issue of protection of the individual. PMID:1002088

  2. PFC Abatement in Capacitevely-Coupled Plasma Reactor

    NASA Astrophysics Data System (ADS)

    Porshnev, P. I.; Alaoui, M.; Diamant, Stela; Francis, Terry; Raoux, Sebastien; Woolston, Mike

    2001-10-01

    A low-pressure plasma reactor, was developed to reduce PFC emissions of dielectric etch tools, is a point-of-use environmentally and economically sound solution. Generally, local electric fields in capacitively-coupled (CC) plasmas are higher than in inductively-coupled (IC) plasmas. As a result, electron energy distributions in CC plasmas have more pronounced high-energy part compared to the ones in IC plasmas. This is particularly important for effective breaking of the strong C-F bonds, which dissociation potentials are observably higher than the average electron energy. CC plasma in the Pegasys (Plasma Exhaust Gas Abatement SYStem) reactor was found to be in so-called g-regime, in which ionization is provided with secondary emission electrons. Though in these plasmas, the majority of electrons still reside in plasma bulk, the most important discharge characteristics, in particular, the abatement efficiency, are determined by highly-energetic electrons from sheath zones. With water being added to the incoming gas mixture, better than 95% destruction removal efficiency of the PFCs has been achieved for all dielectric etch applications. CC plasma-based abatement significantly differs from existing abatement methods, especially combustion and catalytic oxidation, which are much less environmentally friendly and economically viable.

  3. Induced Potential in Porous Carbon Films through Water Vapor Absorption.

    PubMed

    Liu, Kang; Yang, Peihua; Li, Song; Li, Jia; Ding, Tianpeng; Xue, Guobin; Chen, Qian; Feng, Guang; Zhou, Jun

    2016-07-01

    Sustainable electrical potential of tens of millivolts can be induced by water vapor adsorption on a piece of porous carbon film that has two sides with different functional group contents. Integrated experiments, and Monte Carlo and ab initio molecular dynamics simulations reveal that the induced potential originates from the nonhomogeneous distribution of functional groups along the film, especially carboxy groups. Sufficient adsorbed water molecules in porous carbon facilitate the release of protons from the carboxy groups, resulting in a potential drop across the carbon film because of the concentration difference of the released free protons on the two sides. The potential utilization of such a phenomenon is also demonstrated by a self-powered humidity sensor. PMID:27159427

  4. The potential for carbon storage in UK peatlands

    NASA Astrophysics Data System (ADS)

    Rowson, J.; Worrall, F.; Evans, M.; Bonn, A.; Reed, M.; Chapman, D.; Holden, J.

    2008-12-01

    Upland peat soils represent a large terrestrial carbon store and as such have the potential to be either an ongoing net sink of carbon or a significant net source of carbon. In the UK many upland peats are managed for a range of purposes but these purposes have rarely included carbon stewardship. However, there is now an opportunity to consider whether management practices could be altered to enhance storage of carbon in upland peats. Further, there are now voluntary and regulated carbon trading schemes operational throughout Europe that mean stored carbon, if verified, could have an economic and tradeable value. This means that new income streams could become available for upland management. The 'Sustainable Uplands' RELU project has developed a model for calculating carbon fluxes from peat soils that covers all carbon uptake and release pathways (e.g. fluvial and gaseous pathways). The model has been developed so that the impact of common management options within UK upland peats can be considered. The model was run for a decade from 1997-2006 and applied to an area of 550 km2 of upland peat soils in the Peak District. The study estimates that the region is presently a net sink of -62 Ktonnes CO2 equivalent at an average export of - 136 tonnes CO2 equivalent/km2/yr. If management interventions were targeted across the area the total sink could increase to -160 Ktonnes CO2/yr at an average export of- 219 tonnes CO2 equivalent/km2/yr. The model suggests which management interventions would be most effective and given present costs of peatland restoration and value of carbon offsets the study suggests that 51% of those areas, where a carbon benefit was estimated by modelling for targeted action of management interventions, would show a profit from carbon offsetting within 30 years.

  5. AHERA CLEARANCE AT TWENTY ABATEMENT SITES

    EPA Science Inventory

    A study was conducted during the summer of 1988 to document Asbestos Hazard Emergency Response Act (AHERA) clearance air sampling practices and clearance concentrations of airborne asbestos at 20 asbestos-abatement sites in New Jersey. ach abatement took place in a school buildin...

  6. AHERA CLEARANCE AT TWENTY ABATEMENT SITES

    EPA Science Inventory

    A study was conducted during the summer of 1988 to document Asbestos Hazard Emergency Response Act (AHERA) clearance air-sampling practices and clearance concentrations of airborne asbestos at 20 asbestos-abatement sites in New Jersey. Each abatement took place in a school buildi...

  7. An Overview of Geologic Carbon Sequestration Potential in California

    SciTech Connect

    Cameron Downey; John Clinkenbeard

    2005-10-01

    As part of the West Coast Regional Carbon Sequestration Partnership (WESTCARB), the California Geological Survey (CGS) conducted an assessment of geologic carbon sequestration potential in California. An inventory of sedimentary basins was screened for preliminary suitability for carbon sequestration. Criteria included porous and permeable strata, seals, and depth sufficient for critical state carbon dioxide (CO{sub 2}) injection. Of 104 basins inventoried, 27 met the criteria for further assessment. Petrophysical and fluid data from oil and gas reservoirs was used to characterize both saline aquifers and hydrocarbon reservoirs. Where available, well log or geophysical information was used to prepare basin-wide maps showing depth-to-basement and gross sand distribution. California's Cenozoic marine basins were determined to possess the most potential for geologic sequestration. These basins contain thick sedimentary sections, multiple saline aquifers and oil and gas reservoirs, widespread shale seals, and significant petrophysical data from oil and gas operations. Potential sequestration areas include the San Joaquin, Sacramento, Ventura, Los Angeles, and Eel River basins, followed by the smaller Salinas, La Honda, Cuyama, Livermore, Orinda, and Sonoma marine basins. California's terrestrial basins are generally too shallow for carbon sequestration. However, the Salton Trough and several smaller basins may offer opportunities for localized carbon sequestration.

  8. Impact of field exposure on greenhouse gas production potentials from biochar additions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A potential abatement strategy to increasing atmospheric levels of carbon dioxide (CO2) is to sequester atmospheric CO2 into a more stable form through the pyrolysis of biomass. Biomass feed stocks are used to generate a more stable carbon form (biochar) that when added to soils can act place atmosp...

  9. Potential release of fibers from burning carbon composites. [aircraft fires

    NASA Technical Reports Server (NTRS)

    Bell, V. L.

    1980-01-01

    A comprehensive experimental carbon fiber source program was conducted to determine the potential for the release of conductive carbon fibers from burning composites. Laboratory testing determined the relative importance of several parameters influencing the amounts of single fibers released, while large-scale aviation jet fuel pool fires provided realistic confirmation of the laboratory data. The dimensions and size distributions of fire-released carbon fibers were determined, not only for those of concern in an electrical sense, but also for those of potential interest from a health and environmental standpoint. Fire plume and chemistry studies were performed with large pool fires to provide an experimental input into an analytical modelling of simulated aircraft crash fires. A study of a high voltage spark system resulted in a promising device for the detection, counting, and sizing of electrically conductive fibers, for both active and passive modes of operation.

  10. Potential Influence of Perchlorate on Organic Carbon in Martian Regolith

    NASA Astrophysics Data System (ADS)

    Oze, C.; Vithanage, M. S.; Kumarathilaka, P. R.; Indraratne, S.; Horton, T. W.

    2014-12-01

    Perchlorate is a strong oxidizer present at elevated concentrations in surface martian regolith. Chemical and isotopic modification of potential organic carbon with perchlorate in martian regolith during H2O(l) interactions is unknown. Here we assess the relationship between martian levels of perchlorate and organic carbon present in life harbouring geologic material from Earth. These materials represent chemical (i.e., processed serpentine soils from Sri Lanka) and temperature (i.e., hydrothermal jarosite/goethite deposit from White Island, New Zealand) extremes to where life exists on Earth. Preliminary evidence demonstrates that organic carbon decreases and δ13C values are modified for ultramafic sediment in both perchlorate kinetic and incubation experiments. In hydrothermal jarosite/goethite with microbial communities present, total and organic carbon is maintained and little modification in δ13C values is apparent. These preliminary results suggest that surface hydrothermal deposits with mineralogically 'protected' organic carbon are preferable sites to assess the potential of life on Mars.

  11. How Sensitive Is the Carbon Budget Approach to Potential Carbon Cycle Changes?

    NASA Astrophysics Data System (ADS)

    Matthews, D.

    2014-12-01

    The recent development of global Earth-system models, which include dynamic representations of both physical climate and carbon cycle processes, has led to new insights about how the climate responds to human carbon dioxide emissions. Notably, several model analyses have now shown that global temperature responds linearly to cumulative CO2 emissions across a wide range of emissions scenarios. This implies that the timing of CO2 emissions does not affect the overall climate response, and allows a finite global carbon carbon budget to be defined for a given global temperature target. This linear climate response, however, emerges from the interaction of several non-linear processes and feedbacks involving how carbon sinks respond to changes in atmospheric CO2 and climate. In this presentation, I will give an overview of how carbon sinks and carbon cycle feedbacks contribute to the overall linearity of the climate response to cumulative emissions, and will assess how robust this relationship is to a range of possible changes in the carbon cycle, including (a) potential positive carbon cycle feedbacks that are not well represented in the current generation of Earth-system models and (b) negative emission scenarios resulting from possible technological strategies to remove CO2 from the atmosphere.

  12. Comparing carbon sequestration potential of pyrogenic carbon from natural and anthropogenic sources

    NASA Astrophysics Data System (ADS)

    Santin, Cristina; Doerr, Stefan; Merino, Augustin

    2014-05-01

    The enhanced resistance to environmental degradation of Pyrogenic Carbon (PyC), both produced in wildfires (charcoal), and man-made (biochar), gives it the potential to sequester carbon by preventing it to be released into the atmosphere. Sustainable addition of biochar to soils is seen as a viable global approach for carbon sequestration and climate change mitigation. Also the role of its 'natural counterpart', i.e. wildfire charcoal, as a long-term carbon sink in soils is widely recognized. However, in spite of their fundamental similarities, research on the potential of 'man-made' biochar and wildfire charcoal for carbon sequestration has been carried out essentially in isolation as analogous materials for accurate comparison are not easily available. Here we assess the carbon sequestration potential of man-made biochar and wildfire charcoal generated from the same material under known production conditions: (i) charcoal from forest floor and down wood produced during an experimental boreal forest fire (FireSmart, June 2012, NWT- Canada) and (ii) biochar produced from the same feedstock by slow pyrolysis [three treatments: 2 h at 350, 500 and 650°C, respectively]. The carbon sequestration potential of these PyC materials is given by the recalcitrance index, R50, proposed by Harvey et al. (2012). R50 is based on the relative thermal stability of a given PyC material to that of graphite and is calculated using thermogravimetric analyses. Our results show highest R50 for PyC materials produced from down wood than from forest floor, which points to the importance of feedstock chemical composition in determining the C sequestration potential of PyC both from natural (charcoal) and anthropogenic (biochar) sources. Moreover, production temperature is also a major factor affecting the carbon sequestration potential of the studied PyC materials, with higher R50 for PyC produced at higher temperatures. Further investigation on the similarities and differences between man

  13. Properties and potential applications of brominated P-100 carbon fibers

    NASA Technical Reports Server (NTRS)

    Jaworske, D. A.; Gaier, J. R.; Hung, C. C.; Banks, B. A.

    1986-01-01

    A review of the properties and potential applications of bromine-intercalated pitch-based carbon fibers is presented. The dynamics of the intercalation reaction are summarized, and characteristics, such as resistivity, density, and stability, are discussed. In addition, the mechanical and electrical properties of bromine-intercalated fiber-epoxy conposites will be addressed. With conductivities comparable to stainless steel, these brominated carbon fibers may be used in a number of composite applications, such as electromagnetic interference shielding containers, large conductive space structures, lightning strike-tolerant aircraft surfaces, and aircraft deicing applications.

  14. 24 CFR 35.1325 - Abatement.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... authorized by EPA, or by EPA at 40 CFR 745.227(e), and shall be completed by achieving clearance in... accordance with § 35.1355. Abatement of an intact, factory-applied prime coating on metal surfaces is...

  15. 24 CFR 35.1325 - Abatement.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... authorized by EPA, or by EPA at 40 CFR 745.227(e), and shall be completed by achieving clearance in... accordance with § 35.1355. Abatement of an intact, factory-applied prime coating on metal surfaces is...

  16. Interaction of pollution abatement with world dynamics

    NASA Technical Reports Server (NTRS)

    Smith, G. L.

    1973-01-01

    The world dynamics model of Jay W. Forrester was modified to account for pollution abatement. In the modified model, it is assumed that as pollution increases, efforts are made to control pollution. There is a competition between food supply, material standard of living, and pollution abatement for capital, and time is required for diversion of capital toward pollution abatement. Inclusion of pollution abatement in the model drastically alters the response of the world system for the case in which depletion of natural resources is not considered. Instead of undergoing a pollution catastrophe, all system levels move more or less smoothly toward an equilibrium. A FORTRAN program listing of the modified world dynamics model is included.

  17. 24 CFR 35.1325 - Abatement.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... authorized by EPA, or by EPA at 40 CFR 745.227(e), and shall be completed by achieving clearance in accordance with § 35.1340. If encapsulation or enclosure is used as a method of abatement, ongoing...

  18. 24 CFR 35.1325 - Abatement.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... authorized by EPA, or by EPA at 40 CFR 745.227(e), and shall be completed by achieving clearance in accordance with § 35.1340. If encapsulation or enclosure is used as a method of abatement, ongoing...

  19. 24 CFR 35.1325 - Abatement.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... authorized by EPA, or by EPA at 40 CFR 745.227(e), and shall be completed by achieving clearance in accordance with § 35.1340. If encapsulation or enclosure is used as a method of abatement, ongoing...

  20. Low-Potential Stable NADH Detection at Carbon-Nanotube-Modified Glassy Carbon Electrodes

    SciTech Connect

    Musameh, Mustafa; Wang, Joseph; Merkoci, Arben; Lin, Yuehe )

    2002-11-22

    Carbon-nanotube (CNT) modified glassy-carbon electrodes exhibiting strong and stable electrocatalytic response toward NADH are described. A substantial (490 mV) decrease in the overvoltage of the NADH oxidation reaction (compared to ordinary carbon electrodes) is observed using single-wall and multi-wall carbon-nanotube coatings, with oxidation starting at ca.?0.05V (vs. Ag/AgCl; pH 7.4). Furthermore, the NADH amperometric response of the coated electrodes is extremely stable, with 96 and 90% of the initial activity remaining after 60min stirring of 2x10-4M and 5x10-3M NADH solutions, respectively (compared to 20 and 14% at the bare surface). The CNT-coated electrodes thus allow highly-sensitive, low-potential, stable amperometric sensing. Such ability of carbon-nanotubes to promote the NADH electron-transfer reaction suggests great promise for dehydrogenase-based amperometric biosensors.

  1. Carbon stewardship: land management decisions and the potential for carbon sequestration in Colorado, USA

    NASA Astrophysics Data System (ADS)

    Failey, Elisabeth L.; Dilling, Lisa

    2010-04-01

    Land use and its role in reducing greenhouse gases is a key element of policy negotiations to address climate change. Calculations of the potential for enhanced terrestrial sequestration have largely focused on the technical characteristics of carbon stocks, such as vegetation type and management regime, and to some degree, on economic incentives. However, the actual potential for carbon sequestration critically depends on who owns the land and additional land management decision drivers. US land ownership patterns are complex, and consequently land use decision making is driven by a variety of economic, social and policy incentives. These patterns and incentives make up the 'carbon stewardship landscape'—that is, the decision making context for carbon sequestration. We examine the carbon stewardship landscape in the US state of Colorado across several public and private ownership categories. Achieving the full potential for land use management to help mitigate carbon emissions requires not only technical feasibility and financial incentives, but also effective implementing mechanisms within a suite of often conflicting and hard to quantify factors such as multiple-use mandates, historical precedents, and non-monetary decision drivers.

  2. Formation Buffering Potential Pertaining to Geological Storage of Carbon Dioxide

    NASA Astrophysics Data System (ADS)

    Ellis, B. R.; Peters, C. A.; Buschkuehle, M.

    2007-12-01

    One promising strategy for decreasing CO2 emissions to the atmosphere is carbon capture and storage in deep saline formations. Modeling efforts and the experimental measurements that support these efforts are critical to determining the fate of injected CO2. The focus of this work is CO2-water-rock interactions as they pertain to formation buffering potential. PHREEQC was used to model pH evolution in siliciclastic and carbonate rocks after simulated injection of CO2. The initial mineral and formation water compositions were determined from analysis of core samples and brines from several formations in the Alberta sedimentary basin in western Canada. Simulation parameters correspond to injection conditions of 50°C, CO2 pressure of 100 bar and high ionic strength. Results indicate that the carbonate formations have a higher buffering potential relative to siliciclastic formations. Considerable variability of acid-catalyzed reactions among formations with similar mineralogical compositions was also observed. To assess the effect of grain coating by clay minerals, a comparative simulation was performed with kaolinite as the dominant mineral in contact with the pore fluids. Results from this simulation showed a pronounced retardation in pH buffering reaction kinetics. This emphasizes the importance for differentiating between mineral abundance and accessibility in model calculations when clay coatings may obscure contact between pore fluids and potentially reactive minerals.

  3. Historical forest baselines reveal potential for continued carbon sequestration

    PubMed Central

    Rhemtulla, Jeanine M.; Mladenoff, David J.; Clayton, Murray K.

    2009-01-01

    One-third of net CO2 emissions to the atmosphere since 1850 are the result of land-use change, primarily from the clearing of forests for timber and agriculture, but quantifying these changes is complicated by the lack of historical data on both former ecosystem conditions and the extent and spatial configuration of subsequent land use. Using fine-resolution historical survey records, we reconstruct pre-EuroAmerican settlement (1850s) forest carbon in the state of Wisconsin, examine changes in carbon after logging and agricultural conversion, and assess the potential for future sequestration through forest recovery. Results suggest that total above-ground live forest carbon (AGC) fell from 434 TgC before settlement to 120 TgC at the peak of agricultural clearing in the 1930s and has since recovered to approximately 276 TgC. The spatial distribution of AGC, however, has shifted significantly. Former savanna ecosystems in the south now store more AGC because of fire suppression and forest ingrowth, despite the fact that most of the region remains in agriculture, whereas northern forests still store much less carbon than before settlement. Across the state, continued sequestration in existing forests has the potential to contribute an additional 69 TgC. Reforestation of agricultural lands, in particular, the formerly high C-density forests in the north-central region that are now agricultural lands less optimal than those in the south, could contribute 150 TgC. Restoring historical carbon stocks across the landscape will therefore require reassessing overall land-use choices, but a range of options can be ranked and considered under changing needs for ecosystem services. PMID:19369213

  4. Historical forest baselines reveal potential for continued carbon sequestration.

    PubMed

    Rhemtulla, Jeanine M; Mladenoff, David J; Clayton, Murray K

    2009-04-14

    One-third of net CO(2) emissions to the atmosphere since 1850 are the result of land-use change, primarily from the clearing of forests for timber and agriculture, but quantifying these changes is complicated by the lack of historical data on both former ecosystem conditions and the extent and spatial configuration of subsequent land use. Using fine-resolution historical survey records, we reconstruct pre-EuroAmerican settlement (1850s) forest carbon in the state of Wisconsin, examine changes in carbon after logging and agricultural conversion, and assess the potential for future sequestration through forest recovery. Results suggest that total above-ground live forest carbon (AGC) fell from 434 TgC before settlement to 120 TgC at the peak of agricultural clearing in the 1930s and has since recovered to approximately 276 TgC. The spatial distribution of AGC, however, has shifted significantly. Former savanna ecosystems in the south now store more AGC because of fire suppression and forest ingrowth, despite the fact that most of the region remains in agriculture, whereas northern forests still store much less carbon than before settlement. Across the state, continued sequestration in existing forests has the potential to contribute an additional 69 TgC. Reforestation of agricultural lands, in particular, the formerly high C-density forests in the north-central region that are now agricultural lands less optimal than those in the south, could contribute 150 TgC. Restoring historical carbon stocks across the landscape will therefore require reassessing overall land-use choices, but a range of options can be ranked and considered under changing needs for ecosystem services. PMID:19369213

  5. The economic potential of carbon sequestration in Californian agricultural land

    NASA Astrophysics Data System (ADS)

    Catala-Luque, Rosa

    This dissertation studies the potential success of a carbon sequestration policy based on payments to farmers for adoption of alternative, less intensive, management practices in California. Since this is a first approach from a Californian perspective, we focus on Yolo County, an important agricultural county of the State. We focus on the six more important crops of the region: wheat, tomato, corn, rice, safflower, and sunflower. In Chapter 1, we characterize the role of carbon sequestration in Climate Change policy. We also give evidence on which alternative management practices have greenhouse gas mitigation potential (reduced tillage, cover-cropping, and organic systems) based on a study of experimental sites. Chapter 2 advances recognizing the need for information at the field level, and describes the survey designed used to obtain data at the field level, something required to perform a complete integrated assessment of the issue. The survey design is complex in the sense that we use auxiliary information to obtain a control (subpopulation of conventional farmers)-case (subpopulation of innovative farmers) design with stratification for land use. We present estimates for population quantities of interest such as total variable costs, profits, managerial experience in different alternatives, etc. This information efficiently gives field level information for innovative farmers, a missing piece of information so far, since our sampling strategy required the inclusion with probability one of farmers identified as innovative. Using an agronomic process model (DayCent) for the sample and population units, we construct carbon mitigation cost curves for each crop and management observed. Chapter 3 builds different econometric models for cross-sectional data taking into account the survey design, and expanding the sample size constructing productivity potential under each alternative. Based on the yield productivity potential modeled for each unit, we conclude that a

  6. Coarse-grained potentials of single-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Zhao, Junhua; Jiang, Jin-Wu; Wang, Lifeng; Guo, Wanlin; Rabczuk, Timon

    2014-11-01

    We develop the coarse-grained (CG) potentials of single-walled carbon nanotubes (SWCNTs) in CNT bundles and buckypaper for the study of the static and dynamic behaviors. The explicit expressions of the CG stretching, bending and torsion potentials for the nanotubes are obtained by the stick-spiral and the beam models, respectively. The non-bonded CG potentials between two different CG beads are derived from analytical results based on the cohesive energy between two parallel and crossing SWCNTs from the van der Waals interactions. We show that the CG model is applicable to large deformations of complex CNT systems by combining the bonded potentials with non-bonded potentials. Checking against full atom molecular dynamics calculations and our analytical results shows that the present CG potentials have high accuracy. The established CG potentials are used to study the mechanical properties of the CNT bundles and buckypaper efficiently at minor computational cost, which shows great potential for the design of micro- and nanomechanical devices and systems.

  7. Hydrocarbon potential of Middle Eocene carbonates, Sirt Basin, Libya

    NASA Astrophysics Data System (ADS)

    Swei, Giuma H.; Tucker, Maurice E.

    2015-11-01

    Deposition of Middle Eocene carbonates in the Sirt Basin in Libya has been the subject of considerable study in recent years because of the importance of sediments of this age as hydrocarbon reservoirs. The Gialo Formation is an important gas-producing reservoir in the Assumood, Sahl and other nearby fields. The gas which is generated from the gas-prone Sirt Shale source rock of the northern Ajdabiya Trough probably migrated in to the Assumood Ridge from the northeast through late Cretaceous, Paleocene and early Eocene carbonates, before being trapped beneath the Augila Shale (Upper Eocene) which is the principal regional seal in the area. This integrated study has enhanced our understanding of reservoir heterogeneity and hydrocarbon potential of the Gialo carbonates and should lead to improved exploration in the future. Reservoir quality in the Gialo Formation is a function of grain types, pore types, grain size, sorting, cementation and compaction, and predicting areas of high reservoir quality has proved difficult; exploration should be oriented to positioning wells into the main trend of the mid-ramp, nummulite accumulation. Different nummulite facies can be reservoirs depending on their diagenetic history. A diagenetic reduction in porosity must be distinguished from a lack of porosity resulting from an unfavourable depositional environment, so that exploration alternatives can be assessed. This integrated study has demonstrated the presence of suitable reservoir rocks, hydrocarbon traps and the close proximity of potential source rocks. These features should encourage further hydrocarbon exploration in the area.

  8. Abatement of CF4 by atmospheric-pressure microwave plasma torch

    NASA Astrophysics Data System (ADS)

    Hong, Yong C.; Uhm, Han S.

    2003-08-01

    An atmospheric microwave plasma torch is presented for post-pump destruction of perfluorocompound gases (PFCs), which are used widely in the semiconductor industry and are emitted with nitrogen gas for vacuum pump purges. Discharges of the microwave plasma torch are well suited for abatement of PFC contaminants discharged at a typical flow rate. The abatement was carried out using oxygen or air as additive gases. Analytical results are systematically compared to quadrupole mass spectroscopy and Fourier transform infrared (FTIR) data in the laboratory. Destruction and removal efficiency of more than 99% in FTIR data was achieved for carbon tetrafluoride.

  9. Cost of abating greenhouse gas emissions with cellulosic ethanol.

    PubMed

    Dwivedi, Puneet; Wang, Weiwei; Hudiburg, Tara; Jaiswal, Deepak; Parton, William; Long, Stephen; DeLucia, Evan; Khanna, Madhu

    2015-02-17

    We develop an integrated framework to determine and compare greenhouse gas (GHG) intensities and production costs of cellulosic ethanol derived from corn stover, switchgrass, and miscanthus grown on high and low quality soils for three representative counties in the Eastern United States. This information is critical for assessing the cost-effectiveness of utilizing cellulosic ethanol for mitigating GHG emissions and designing appropriate policy incentives to support cellulosic ethanol production nationwide. We find considerable variations in the GHG intensities and production costs of ethanol across feedstocks and locations mostly due to differences in yields and soil characteristics. As compared to gasoline, the GHG savings from miscanthus-based ethanol ranged between 130% and 156% whereas that from switchgrass ranged between 97% and 135%. The corresponding range for GHG savings with corn stover was 57% to 95% and marginally below the threshold of at least 60% for biofuels classified as cellulosic biofuels under the Renewable Fuels Standard. Estimates of the costs of producing ethanol relative to gasoline imply an abatement cost of at least $48 Mg(-1) of GHG emissions (carbon dioxide equivalent) abated and can be used to infer the minimum carbon tax rate needed to induce consumption of cellulosic ethanol. PMID:25588032

  10. Impacts of Woodchip Biochar Additions on Soil Carbon Net, CH4 Oxidation and Sorption/Degradation of Two Herbicides in a Minnesota Soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A potential abatement to increasing levels of carbon dioxide (CO2) in the atmosphere is the use of pyrolysis to convert vegetative biomass into a more stable form of carbon (biochar) that could then be applied to the soil. However, the impacts of pyrolysis biochar on the soil system need to be asses...

  11. Potential climate impact of black carbon emitted by rockets

    NASA Astrophysics Data System (ADS)

    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. Anesthesia-Related Carbon Monoxide Exposure: Toxicity and Potential Therapy.

    PubMed

    Levy, Richard J

    2016-09-01

    Exposure to carbon monoxide (CO) during general anesthesia can result from volatile anesthetic degradation by carbon dioxide absorbents and rebreathing of endogenously produced CO. Although adherence to the Anesthesia Patient Safety Foundation guidelines reduces the risk of CO poisoning, patients may still experience subtoxic CO exposure during low-flow anesthesia. The consequences of such exposures are relatively unknown. In contrast to the widely recognized toxicity of high CO concentrations, the biologic activity of low concentration CO has recently been shown to be cytoprotective. As such, low-dose CO is being explored as a novel treatment for a variety of different diseases. Here, we review the concept of anesthesia-related CO exposure, identify the sources of production, detail the mechanisms of overt CO toxicity, highlight the cellular effects of low-dose CO, and discuss the potential therapeutic role for CO as part of routine anesthetic management. PMID:27537758

  13. Potential for Carbon Dioxide Sequestration in Flood Basalts

    SciTech Connect

    McGrail, B. PETER; Schaef, Herbert T.; Ho, Anita M.; Chien, Yi-Ju; Dooley, James J.; Davidson, Casie L.

    2006-12-01

    Flood basalts are a potentially important host medium for geologic sequestration of anthropogenic CO2. Most lava flows have flow tops that are porous, permeable, and have enormous capacity for storage of CO2. Interbedded sediment layers and dense low-permeability basalt rock overlying sequential flows may act as effective seals allowing time for mineralization reactions to occur. Laboratory experiments confirm relatively rapid chemical reaction of CO2-saturated pore water with basalts to form stable carbonate minerals. Calculations suggest a sufficiently short time frame for onset of carbonate precipitation after CO2 injection that verification of in situ mineralization rates appears feasible in field pilot studies. If proven viable, major flood basalts in the U.S. and India would provide significant additional CO2 storage capacity and additional geologic sequestration options in certain regions where more conventional storage options are limited.

  14. Tobacco litter costs and public policy: a framework and methodology for considering the use of fees to offset abatement costs

    PubMed Central

    Peterson, N Andrew; Kiss, Noemi; Ebeid, Omar; Doyle, Alexis S

    2011-01-01

    Objectives Growing concern over the costs, environmental impact and safety of tobacco product litter (TPL) has prompted states and cities to undertake a variety of policy initiatives, of which litter abatement fees are part. The present work describes a framework and methodology for calculating TPL costs and abatement fees. Methods Abatement is associated with four categories of costs: (1) mechanical and manual abatement from streets, sidewalks and public places, (2) mechanical and manual abatement from storm water and sewer treatment systems, (3) the costs associated with harm to the ecosystem and harm to industries dependent on clean and healthy ecosystems, and (4) the costs associated with direct harm to human health. The experiences of the City of San Francisco's recently proposed tobacco litter abatement fee serve as a case study. Results City and municipal TPL costs are incurred through manual and mechanical clean-up of surfaces and catchment areas. According to some studies, public litter abatement costs to US cities range from US$3 million to US$16 million. TPL typically comprises between 22% and 36% of all visible litter, implying that total public TPL direct abatement costs range from about US$0.5 million to US$6 million for a city the size of San Francisco. The costs of mitigating the negative externalities of TPL in a city the size of San Francisco can be offset by implementing a fee of approximately US$0.20 per pack. Conclusions Tobacco litter abatement costs to cities can be substantial, even when the costs of potential environmental pollution and tourism effects are excluded. One public policy option to address tobacco litter is levying of fees on cigarettes sold. The methodology described here for calculating TPL costs and abatement fees may be useful to state and local authorities who are considering adoption of this policy initiative. PMID:21504923

  15. Experimental Study of Potential Wellbore Cement Carbonation by Various Phases of Carbon Dioxide during Geologic Carbon Sequestration

    NASA Astrophysics Data System (ADS)

    Jung, H.; Um, W.

    2012-12-01

    Hydrated Portland cement was reacted with three different carbon dioxide (CO2) phases (supercritical, gaseous, and aqueous) to understand potential cement alteration processes along the length of a wellbore, extending from the deep CO2 storage reservoir to the shallow subsurface. Three-dimensional X-ray microtomography (XMT) images showed that cement alteration was significantly more extensive in CO2-saturated water experiments than in dry or wet supercritical CO2 experiments at high P (10 MPa)-T (50°C) conditions. XMT imaging was capable of visualizing the degradation front with lower density and higher porosity as well as the carbonated zone with higher density and lower porosity in the cement matrix altered by CO2-saturated water. Scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) analysis showed a systematic change in Ca and C atom % in the cement matrix after reaction with CO2-saturated water for 1-5 months due to Ca depletion and C enrichment as a result of progressive carbonation. Integrated XMT and SEM-EDS analyses revealed that cement carbonation by CO2-saturated water formed three alteration zones; the degradation front, the carbonated zone, and the outermost porous zone. Cement pores in the carbonated zone were filled with CaCO3(s), resulting in a decrease in the porosity and permeability of the cement columns by an order of magnitude. In contrast, cement carbonation by dry or wet supercritical CO2 was slow and minor, and only a thin single carbonation zone was formed after exposure to dry supercritical CO2 for 15 months. Extensive calcite coating was formed on the outside surface of a cement sample after exposure to wet gaseous CO2 for 1-3 months, which reduced the pore volume of the cement by a factor of 3-6. The chemical-physical characterization of hydrated Portland cement after exposure to various phases of carbon dioxide indicates that the extent of cement carbonation can be significantly heterogeneous depending on CO2

  16. FEASIBILITY OF ELK CREEK ACID MINE DRAINAGE ABATEMENT PROJECT

    EPA Science Inventory

    A study was conducted within the Elk Creek Watershed, West Virginia to determine the technical and economic feasibility of three acid mine drainage abatement techniques. Alkaline regarding and slurry trench construction were established as technically and economically viable abat...

  17. Soil Organic Carbon Loss: An Overlooked Factor in the Carbon Sequestration Potential of Enhanced Mineral Weathering

    NASA Astrophysics Data System (ADS)

    Dietzen, Christiana; Harrison, Robert

    2016-04-01

    Weathering of silicate minerals regulates the global carbon cycle on geologic timescales. Several authors have proposed that applying finely ground silicate minerals to soils, where organic acids would enhance the rate of weathering, could increase carbon uptake and mitigate anthropogenic CO2 emissions. Silicate minerals such as olivine could replace lime, which is commonly used to remediate soil acidification, thereby sequestering CO2 while achieving the same increase in soil pH. However, the effect of adding this material on soil organic matter, the largest terrestrial pool of carbon, has yet to be considered. Microbial biomass and respiration have been observed to increase with decreasing acidity, but it is unclear how long the effect lasts. If the addition of silicate minerals promotes the loss of soil organic carbon through decomposition, it could significantly reduce the efficiency of this process or even create a net carbon source. However, it is possible that this initial flush of microbial activity may be compensated for by additional organic matter inputs to soil pools due to increases in plant productivity under less acidic conditions. This study aimed to examine the effects of olivine amendments on soil CO2 flux. A liming treatment representative of typical agricultural practices was also included for comparison. Samples from two highly acidic soils were split into groups amended with olivine or lime and a control group. These samples were incubated at 22°C and constant soil moisture in jars with airtight septa lids. Gas samples were extracted periodically over the course of 2 months and change in headspace CO2 concentration was determined. The effects of enhanced mineral weathering on soil organic matter have yet to be addressed by those promoting this method of carbon sequestration. This project provides the first data on the potential effects of enhanced mineral weathering in the soil environment on soil organic carbon pools.

  18. Continuous nitrous oxide abatement in a novel denitrifying off-gas bioscrubber.

    PubMed

    Frutos, Osvaldo D; Arvelo, Ilan A; Pérez, Rebeca; Quijano, Guillermo; Muñoz, Raúl

    2015-04-01

    The potential of a bioscrubber composed of a packed bed absorption column coupled to a stirred tank denitrification bioreactor (STR) was assessed for 95 days for the continuous abatement of a diluted air emission of N2O at different liquid recycling velocities. N2O removal efficiencies of up to 40 ± 1 % were achieved at the highest recirculation velocity (8 m h(-1)) at an empty bed residence time of 3 min using a synthetic air emission containing N2O at 104 ± 12 ppmv. N2O was absorbed in the packed bed column and further reduced in the STR at efficiencies >80 % using methanol as electron donor. The long-term operation of the bioscrubber suggested that the specialized N2O degrading community established was not able to use N2O as nitrogen source. Additional nitrification assays showed that the activated sludge used as inoculum was not capable of aerobically oxidizing N2O to nitrate or nitrite, regardless of the inorganic carbon concentration tested. Denitrification assays confirmed the ability of non-acclimated activated sludge to readily denitrify N2O at a specific rate of 3.9 mg N2O g VSS h(-1) using methanol as electron donor. This study constitutes, to the best of our knowledge, the first systematic assessment of the continuous abatement of N2O in air emission. A characterization of the structure of the microbial population in the absorption column by DGGE-sequencing revealed a high microbial diversity and the presence of heterotrophic denitrifying methylotrophs. PMID:25547842

  19. OPTIONS FOR ABATING GREENHOUSE GASES FROM EXHAUST STREAMS.

    SciTech Connect

    FTHENAKIS,V.

    2001-12-01

    This report examines different alternatives for replacing, treating, and recycling greenhouse gases. It is concluded that treatment (abatement) is the only viable short-term option. Three options for abatement that were tested for use in semiconductor facilities are reviewed, and their performance and costs compared. This study shows that effective abatement options are available to the photovoltaic (PV) industry, at reasonable cost.

  20. 23 CFR 772.13 - Analysis of noise abatement.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... standard and in conformance with the provisions of 40 CFR 1506.5(c) and 23 CFR 636.109. (j) Third party... PROCEDURES FOR ABATEMENT OF HIGHWAY TRAFFIC NOISE AND CONSTRUCTION NOISE § 772.13 Analysis of noise abatement. (a) When traffic noise impacts are identified, noise abatement shall be considered and evaluated...

  1. 23 CFR 772.13 - Analysis of noise abatement.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 23 Highways 1 2012-04-01 2012-04-01 false Analysis of noise abatement. 772.13 Section 772.13 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RIGHT-OF-WAY AND ENVIRONMENT PROCEDURES FOR ABATEMENT OF HIGHWAY TRAFFIC NOISE AND CONSTRUCTION NOISE § 772.13 Analysis of noise abatement. (a) When traffic noise impacts are...

  2. 23 CFR 772.13 - Analysis of noise abatement.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 23 Highways 1 2013-04-01 2013-04-01 false Analysis of noise abatement. 772.13 Section 772.13 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RIGHT-OF-WAY AND ENVIRONMENT PROCEDURES FOR ABATEMENT OF HIGHWAY TRAFFIC NOISE AND CONSTRUCTION NOISE § 772.13 Analysis of noise abatement. (a) When traffic noise impacts are...

  3. 10 CFR 851.22 - Hazard prevention and abatement.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Hazard prevention and abatement. 851.22 Section 851.22 Energy DEPARTMENT OF ENERGY WORKER SAFETY AND HEALTH PROGRAM Specific Program Requirements § 851.22 Hazard prevention and abatement. (a) Contractors must establish and implement a hazard prevention and abatement process to ensure that all identified...

  4. POLLUTION ABATEMENT COSTS AND EXPENDITURES SURVEY

    EPA Science Inventory

    The Pollution Abatement Costs and Expenditures (PACE) Survey is a Census Bureau product funded via a cooperative agreement with EPA. PACE data was collected by Census from 1974-1996 (except 1987) and 1999. The survey consists of approximately 20,000 manufacturing facilities in ...

  5. 29 CFR 4207.3 - Abatement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... section, as appropriate. If a bond or escrow has been provided to the plan under § 4207.4, the plan sponsor shall send a copy of the notice to the bonding or escrow agent. (c) Effects of abatement. If the... applicable; (3) Any bonds furnished under § 4207.4 shall be cancelled and any amounts held in escrow...

  6. 29 CFR 4207.3 - Abatement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... section, as appropriate. If a bond or escrow has been provided to the plan under § 4207.4, the plan sponsor shall send a copy of the notice to the bonding or escrow agent. (c) Effects of abatement. If the... applicable; (3) Any bonds furnished under § 4207.4 shall be cancelled and any amounts held in escrow...

  7. The potential of clear-sky carbon dioxide satellite retrievals

    NASA Astrophysics Data System (ADS)

    Nelson, Robert R.; O'Dell, Christopher W.; Taylor, Thomas E.; Mandrake, Lukas; Smyth, Mike

    2016-04-01

    Since the launch of the Greenhouse Gases Observing Satellite (GOSAT) in 2009, retrieval algorithms designed to infer the column-averaged dry-air mole fraction of carbon dioxide (XCO2) from hyperspectral near-infrared observations of reflected sunlight have been greatly improved. They now generally include the scattering effects of clouds and aerosols, as early work found that absorption-only retrievals, which neglected these effects, often incurred unacceptably large errors, even for scenes with optically thin cloud or aerosol layers. However, these "full-physics" retrievals tend to be computationally expensive and may incur biases from trying to deduce the properties of clouds and aerosols when there are none present. Additionally, algorithms are now available that can quickly and effectively identify and remove most scenes in which cloud or aerosol scattering plays a significant role. In this work, we test the hypothesis that non-scattering, or "clear-sky", retrievals may perform as well as full-physics retrievals for sufficiently clear scenes. Clear-sky retrievals could potentially avoid errors and biases brought about by trying to infer properties of clouds and aerosols when none are present. Clear-sky retrievals are also desirable because they are orders of magnitude faster than full-physics retrievals. Here we use a simplified version of the Atmospheric Carbon Observations from Space (ACOS) XCO2 retrieval algorithm that does not include the scattering and absorption effects of clouds or aerosols. It was found that for simulated Orbiting Carbon Observatory-2 (OCO-2) measurements, the clear-sky retrieval had errors comparable to those of the full-physics retrieval. For real GOSAT data, the clear-sky retrieval had errors 0-20 % larger than the full-physics retrieval over land and errors roughly 20-35 % larger over ocean, depending on filtration level. In general, the clear-sky retrieval had XCOAbatement of methane emissions from landfills -- the German way

    SciTech Connect

    Angerer, G.; Kalb, H.

    1996-12-31

    Landfills are a major source of methane. Methane is generated by biological degradation of native organic matter under anaerobic conditions. In Germany one quarter to one third of the total methane emissions into the air originate from landfills for municipal wastes. These emissions amounts to 1.2--1.9 million metric tons annually. Landfills represent the second most important methane source. For stock farming the technical opportunities to reduce methane emissions are limited. Therefore, environmental policy aiming to abate methane emissions focuses on waste management. In Germany the most effective policy instrument for this task is the Third Administrative Provision to the waste framework law. This provision came into operation in 1993 and requires that waste disposed in landfills must be inert. Beginning in the year 2005 the total organic carbon (TOC) content of the waste will be limited to 1--3%. This limit requires a pretreatment of municipal waste, and among the currently available technology options only an incineration is able to fulfill the stipulated criteria. Methane abatement will be further regulated by the new waste law, Cycle Economy and Waste Law.

  8. Carbon dynamics of Oregon and Northern California forests and potential land-based carbon storage.

    PubMed

    Hudiburg, Tara; Law, Beverly; Turner, David P; Campbell, John; Donato, Dan; Duane, Maureen

    2009-01-01

    Net uptake of carbon from the atmosphere (net ecosystem production, NEP) is dependent on climate, disturbance history, management practices, forest age, and forest type. To improve understanding of the influence of these factors on forest carbon stocks and flux in the western United States, federal inventory data and supplemental field measurements at additional plots were used to estimate several important components of the carbon balance in forests in Oregon and Northern California during the 1990s. Species- and ecoregion-specific allometric equations were used to estimate live and dead biomass stores, net primary productivity (NPP), and mortality. In the semiarid East Cascades and mesic Coast Range, mean total biomass was 8 and 24 kg C/m2, and mean NPP was 0.30 and 0.78 kg C.m(-2).yr(-1), respectively. Maximum NPP and dead biomass stores were most influenced by climate, whereas maximum live biomass stores and mortality were most influenced by forest type. Within ecoregions, mean live and dead biomass were usually higher on public lands, primarily because of the younger age class distribution on private lands. Decrease in NPP with age was not general across ecoregions, with no marked decline in old stands (>200 years old) in some ecoregions. In the absence of stand-replacing disturbance, total landscape carbon stocks could theoretically increase from 3.2 +/- 0.34 Pg C to 5.9 +/- 1.34 Pg C (a 46% increase) if forests were managed for maximum carbon storage. Although the theoretical limit is probably unattainable, given the timber-based economy and fire regimes in some ecoregions, there is still potential to significantly increase the land-based carbon storage by increasing rotation age and reducing harvest rates. PMID:19323181

  9. Experimental study of potential wellbore cement carbonation by various phases of carbon dioxide during geologic carbon sequestration

    SciTech Connect

    Jung, Hun Bok; Um, Wooyong

    2013-08-16

    Hydrated Portland cement was reacted with carbon dioxide (CO2) in supercritical, gaseous, and aqueous phases to understand the potential cement alteration processes along the length of a wellbore, extending from deep CO2 storage reservoir to the shallow subsurface during geologic carbon sequestration. The 3-D X-ray microtomography (XMT) images displayed that the cement alteration was significantly more extensive by CO2-saturated synthetic groundwater than dry or wet supercritical CO2 at high P (10 MPa)-T (50°C) conditions. Scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) analysis also exhibited a systematic Ca depletion and C enrichment in cement matrix exposed to CO2-saturated groundwater. Integrated XMT, XRD, and SEM-EDS analyses identified the formation of extensive carbonated zone filled with CaCO3(s), as well as the porous degradation front and the outermost silica-rich zone in cement after exposure to CO2-saturated groundwater. The cement alteration by CO2-saturated groundwater for 2-8 months overall decreased the porosity from 31% to 22% and the permeability by an order of magnitude. Cement alteration by dry or wet supercritical CO2 was slow and minor compared to CO2-saturated groundwater. A thin single carbonation zone was formed in cement after exposure to wet supercritical CO2 for 8 months or dry supercritical CO2 for 15 months. Extensive calcite coating was formed on the outside surface of a cement sample after exposure to wet gaseous CO2 for 1-3 months. The chemical-physical characterization of hydrated Portland cement after exposure to various phases of carbon dioxide indicates that the extent of cement carbonation can be significantly heterogeneous depending on CO2 phase present in the wellbore environment. Both experimental and geochemical modeling results suggest that wellbore cement exposure to supercritical, gaseous, and aqueous phases of CO2 during geologic carbon sequestration is unlikely to damage the wellbore

  10. The potential of clear-sky carbon dioxide satellite retrievals

    NASA Astrophysics Data System (ADS)

    Nelson, R. R.; O'Dell, C. W.; Taylor, T. E.; Mandrake, L.; Smyth, M.

    2015-12-01

    Since the launch of the Greenhouse Gases Observing Satellite (GOSAT) in 2009, retrieval algorithms designed to infer the column-averaged dry-air mole fraction of carbon dioxide (XCO2) from hyperspectral near-infrared observations of reflected sunlight have been greatly improved. They now generally include the scattering effects of clouds and aerosols, as early work found that absorption-only retrievals, which neglected these effects, often incurred unacceptably large errors, even for scenes with optically thin cloud or aerosol layers. However, these "full-physics" retrievals tend to be computationally expensive and may incur biases from trying to deduce the properties of clouds and aerosols when there are none present. Additionally, algorithms are now available that can quickly and effectively identify and remove most scenes in which cloud or aerosol scattering plays a significant role. In this work, we test the hypothesis that non-scattering, or "clear-sky", retrievals may perform as well as full-physics retrievals for sufficiently clear scenes. Clear-sky retrievals could potentially avoid errors and biases brought about by trying to infer properties of clouds and aerosols when none are present. Clear-sky retrievals are also desirable because they are orders of magnitude faster than full-physics retrievals. Here we use a simplified version of the Atmospheric Carbon Observations from Space (ACOS) XCO2 retrieval algorithm that does not include the scattering and absorption effects of clouds or aerosols. It was found that for simulated Orbiting Carbon Observatory-2 (OCO-2) measurements, the clear-sky retrieval had errors comparable to those of the full-physics retrieval. For real GOSAT data, the clear-sky retrieval had nearly indistinguishable error characteristics over land, but roughly 30-60 % larger errors over ocean, depending on filtration level, compared to the full-physics retrieval. In general, the clear-sky retrieval had XCO2 root-mean-square (RMS) errors of

  11. Genotoxicity of carbon nanofibers: are they potentially more or less dangerous than carbon nanotubes or asbestos?

    PubMed Central

    Kisin, E. R.; Murray, A.R.; Sargent, L.; Lowry, D.; Chirila, M.; Siegrist, K.J.; Schwegler-Berry, D.; Leonard, S.; Castranova, V.; Fadeel, B.; Kagan, V.E.; Shvedova, A.A.

    2011-01-01

    The production of carbon nanofibers and nanotubes (CNF/CNT) and their composite products is increasing globally. CNF are generating great interest in industrial sectors such as energy production and electronics, where alternative materials may have limited performance or are produced at a much higher cost. However, despite the increasing industrial use of carbon nanofibers, information on their potential adverse health effects is limited. In the current study, we examine the cytotoxic and genotoxic potential of carbon-based nanofibers (Pyrograf®-III) and compare this material with the effects of asbestos fibers (crocidolite) or single-walled carbon nanotubes (SWCNT). The genotoxic effects in the lung fibroblast (V79) cell line were examined using two complementary assays: the comet assay and micronucleus (MN) test. In addition, we utilized fluorescence in situ hybridization to detect the chromatin pan-centromeric signals within the MN indicating their origin by aneugenic (chromosomal malsegregation) or clastogenic (chromosome breakage) mechanisms. Cytotoxicity tests revealed a concentration- and time-dependent loss of V79 cell viability after exposure to all tested materials in the following sequence: asbestos>CNF>SWCNT. Additionally, cellular uptake and generation of oxygen radicals was seen in the murine RAW264.7 macrophages following exposure to CNF or asbestos but not after administration of SWCNT. DNA damage and MN induction were found after exposure to all tested materials with the strongest effect seen for CNF. Finally, we demonstrated that CNF induced predominately centromere-positive MN in primary human small airway epithelial cells (SAEC) indicating aneugenic events. Further investigations are warranted to elucidate the possible mechanisms involved in CNF-induced genotoxicity. PMID:21310169

  12. Genotoxicity of carbon nanofibers: Are they potentially more or less dangerous than carbon nanotubes or asbestos?

    SciTech Connect

    Kisin, E.R.; Murray, A.R.; Sargent, L.; Lowry, D.; Chirila, M.; Siegrist, K.J.; Schwegler-Berry, D.; Leonard, S.; Castranova, V.; Fadeel, B.; Kagan, V.E.; Shvedova, A.A.

    2011-04-01

    The production of carbon nanofibers and nanotubes (CNF/CNT) and their composite products is increasing globally. CNF are generating great interest in industrial sectors such as energy production and electronics, where alternative materials may have limited performance or are produced at a much higher cost. However, despite the increasing industrial use of carbon nanofibers, information on their potential adverse health effects is limited. In the current study, we examine the cytotoxic and genotoxic potential of carbon-based nanofibers (Pyrograf (registered) -III) and compare this material with the effects of asbestos fibers (crocidolite) or single-walled carbon nanotubes (SWCNT). The genotoxic effects in the lung fibroblast (V79) cell line were examined using two complementary assays: the comet assay and micronucleus (MN) test. In addition, we utilized fluorescence in situ hybridization to detect the chromatin pan-centromeric signals within the MN indicating their origin by aneugenic (chromosomal malsegregation) or clastogenic (chromosome breakage) mechanisms. Cytotoxicity tests revealed a concentration- and time-dependent loss of V79 cell viability after exposure to all tested materials in the following sequence: asbestos > CNF > SWCNT. Additionally, cellular uptake and generation of oxygen radicals was seen in the murine RAW264.7 macrophages following exposure to CNF or asbestos but not after administration of SWCNT. DNA damage and MN induction were found after exposure to all tested materials with the strongest effect seen for CNF. Finally, we demonstrated that CNF induced predominately centromere-positive MN in primary human small airway epithelial cells (SAEC) indicating aneugenic events. Further investigations are warranted to elucidate the possible mechanisms involved in CNF-induced genotoxicity.

  13. Abating environmentally harmful waste gases

    NASA Astrophysics Data System (ADS)

    Sridhar, S.; Sichen, Du; Pal, U. B.; Seetharaman, S.

    2002-05-01

    A gas-purification method, based on the condensation of nitrogen, sulfur, and carbon-containing environmentally hazardous gases produced from industrial processes, is proposed in this article. The method, which utilizes the cooling capacity of waste nitrogen in the oxygen plant to condense the hazardous gases, is capable of removing hazardous impurities up to 99.98%. Theoretical calculations underlying the condensation process are presented employing gases produced in a blast furnace and coke oven in an integrated steel plant. The cooling power required for the condensation process is calculated using the waste nitrogen generated from an oxygen plant that generates captive oxygen for the steel plant. Design modifications that need to be made to the oxygen plant in order to utilize the cooling power of the waste nitrogen gas are also presented. As a case study, the advantages of the method are illustrated with purification of coke-oven gas. The economic impact and the investment aspects are also discussed.

  14. Soil organic carbon of an intensively reclaimed region in China: Current status and carbon sequestration potential.

    PubMed

    Deng, Xunfei; Zhan, Yu; Wang, Fei; Ma, Wanzhu; Ren, Zhouqiao; Chen, Xiaojia; Qin, Fangjin; Long, Wenli; Zhu, Zhenling; Lv, Xiaonan

    2016-09-15

    Land reclamation has been highly intensive in China, resulting in a large amount of soil organic carbon (SOC) loss to the atmosphere. Evaluating the factors which drive SOC dynamics and carbon sequestration potential in reclaimed land is critical for improving soil fertility and mitigating global warming. This study aims to determine the current status and factors important to the SOC density in a typical reclaimed land located in Eastern China, where land reclamation has been undergoing for centuries. A total of 4746 topsoil samples were collected from 2007 to 2010. The SOC density of the reclaimed land (3.18±0.05kgCm(-2); mean±standard error) is significantly lower than that of the adjacent non-reclaimed land (5.71±0.04kgCm(-2)) (p<0.05). A Random Forest model is developed and it captures the relationships between the SOC density and the environmental/anthropogenic factors (R(2)=0.59). The soil pH, land use, and elevation are the most important factors for determining SOC dynamics. In contrast, the effect of the reclamation age on the SOC density is negligible, where SOC content in the land reclaimed during years 1047-1724 is as low as that reclaimed during years 1945-2004. The scenario analysis results indicate that the carbon sequestration potential of the reclaimed lands may achieve a maximum of 5.80±1.81kgCO2m(-2) (mean±SD) when dryland is converted to flooded land with vegetable-rice cropping system and soil pH of ~5.9. Note that in some scenarios the methane emission substantially offsets the carbon sequestration potential, especially for continuous rice cropping system. With the optimal setting for carbon sequestration, it is estimated that the dryland reclaimed in the last 50years in China is able to sequester 0.12milliontons CO2 equivalent per year. PMID:27196991

  15. The streaming potential of liquid carbon dioxide in Berea sandstone

    NASA Astrophysics Data System (ADS)

    Moore, Jeffrey R.; Glaser, Steven D.; Morrison, H. Frank; Hoversten, G. Michael

    2004-09-01

    We report here, for the first time, evolution of the streaming potential coupling coefficient as liquid carbon dioxide infiltrates Berea sandstone. Using 125 Ω-m tap water, the coupling coefficient determined before and after each CO2 flood of five samples averaged approximately -30 mV/0.1 MPa. After liquid CO2 passed through the specimens displacing all mobile pore water, trapped water remained and the coupling coefficient was approximately -3 mV/0.1 MPa. A bound water limit of the coupling coefficient for liquid CO2 flow was found using an air-dried sample to be -0.02 mV/0.1 MPa. For initially water-saturated samples, bulk resistivity varied during CO2 invasion from 330 Ω-m, to 150 Ω-m during CO2/water mixing, to a final value of 380 Ω-m. Results suggest that trapped and bound water control electrical conduction and the electrokinetic response. Applications include monitoring CO2 injectate in subsurface reservoirs using the self potential method.

  16. Potential release scenarios for carbon nanotubes used in composites.

    PubMed

    Nowack, Bernd; David, Raymond M; Fissan, Heinz; Morris, Howard; Shatkin, Jo Anne; Stintz, Michael; Zepp, Richard; Brouwer, Derk

    2013-09-01

    The expected widespread use of carbon nanotube (CNT)-composites in consumer products calls for an assessment of the possible release and exposure to workers, consumers and the environment. Release of CNTs may occur at all steps in the life cycle of products, but to date only limited information is available about release of CNTs from actual products and articles. As a starting point for exposure assessment, exploring sources and pathways of release helps to identify relevant applications and situations where the environment and especially humans may encounter releases of CNTs. It is the aim of this review to identify various potential release scenarios for CNTs used in polymers and identify the greatest likelihood of release at the various stages throughout the life-cycle of the product. The available information on release of CNTs from products and articles is reviewed in a first part. In a second part nine relevant release scenarios are described in detail: injection molding, manufacturing, sports equipment, electronics, windmill blades, fuel system components, tires, textiles, incineration, and landfills. Release from products can potentially occur by two pathways; (a) where free CNTs are released directly, or more frequently (b) where the initial release is a particle with CNTs embedded in the matrix, potentially followed by the subsequent release of CNTs from the matrix. The potential for release during manufacturing exists for all scenarios, however, this is also the situation when exposure can be best controlled. For most of the other life cycle stages and their corresponding release scenarios, potential release of CNTs can be considered to be low, but it cannot be excluded totally. Direct release to the environment is also considered to be very low for most scenarios except for the use of CNTs in tires where significant abrasion during use and release into the environment would occur. Also the possible future use of CNTs in textiles could result in consumer

  17. MICROBIAL ECOLOGY OF POLLUTION ABATEMENT

    EPA Science Inventory

    My career started with Cliff Dahm at the University of New Mexico. The western United States had been experiencing a new “gold rush” using cyanide to mine previously unextractable, low-grade ore and we studied the potential to stimulate native cyanide-degrading micro...

  18. New insights into the nation's carbon storage potential

    USGS Publications Warehouse

    Warwick, Peter D.; Zhu, Zhi-Liang

    2012-01-01

    Carbon sequestration is a method of securing carbon dioxide (CO2) to prevent its release into the atmosphere, where it contributes to global warming as a greenhouse gas. Geologic storage of CO2 in porous and permeable rocks involves injecting high-pressure CO2 into a subsurface rock unit that has available pore space. Biologic carbon sequestration refers to both natural and anthropogenic processes by which CO2 is removed from the atmosphere and stored as carbon in vegetation, soils, and sediments.

  19. Abating exhaust noises in jet engines

    NASA Technical Reports Server (NTRS)

    Schwartz, I. R. (Inventor)

    1974-01-01

    A noise abating improvement for jet engines including turbojets, turbofans, turboprops, ramjets, scramjets, and hybrid jets is introduced. A provision is made for an apparatus in the primary and/or secondary flow streams of the engines; the apparatus imparts to the exhaust gases a component rotation or swirl about the engine's longitudinal axis. The rotary component in the exhaust gases causes a substantial suppression of sound energy build up normally produced by an axial flow exhaust system.

  1. Carbon Sequestration Potential in Mangrove Wetlands of Southern of India

    NASA Astrophysics Data System (ADS)

    Chokkalingam, L.; Ponnambalam, K.; Ponnaiah, J. M.; Roy, P.; Sankar, S.

    2012-12-01

    Mangrove forest and the soil on which it grows are major sinks of atmospheric carbon. We present the results of a study on the carbon sequestration in the ground biomass of Avicennia marina including the organic carbon deposition, degradation and preservation in wetland sediments of Muthupet mangrove forest (southeast coast of India) in order to evaluate the influence of forests in the global carbon cycle. The inventory for estimating the ground biomass of Avicennia marina was carried out using random sampling technique (10 m × 10 m plot) with allometric regression equation. The carbon content in different vegetal parts (leaves, stem and root) of mangrove species and associated marshy vegetations was estimated using the combustion method. We observe that the organic carbon was higher (ca. 54.8%) recorded in the stems of Aegiceras corniculatum and Salicornia brachiata and lower (ca. 30.3%) in the Sesuvium portulacastrum leaves. The ground biomass and carbon sequestration of Avicennia marina are 58.56±12.65 t/ ha and 27.52±5.95 mg C/ha, respectively. The depth integrated organic carbon model profiles indicate an average accumulation rate of 149.75gC/m2.yr and an average remineralization rate of 32.89gC/m2.yr. We estimate an oxidation of ca. 21.85% of organic carbon and preservation of ca. 78.15% of organic carbon in the wetland sediments. Keywords: Above ground biomass, organic carbon, sequestration, mangrove, wetland sediments, Muthupet.

  2. Potential Carbon Negative Commercial Aviation through Land Management

    NASA Technical Reports Server (NTRS)

    Hendricks, Robert C.

    2008-01-01

    Brazilian terra preta soil and char-enhanced soil agricultural systems have demonstrated both enhanced plant biomass and crop yield and functions as a carbon sink. Similar carbon sinking has been demonstrated for both glycophyte and halophyte plants and plant roots. Within the assumption of 3.7 t-C/ha/yr soils and plant root carbon sinking, it is possible to provide carbon neutral U.S. commercial aviation using about 8.5% of U.S. arable lands. The total airline CO2 release would be offset by carbon credits for properly managed soils and plant rooting, becoming carbon neutral for carbon sequestered synjet processing. If these lands were also used to produce biomass fuel crops such as soybeans at an increased yield of 60 bu/acre (225gal/ha), they would provide over 3.15 10(exp 9) gallons biodiesel fuel. If all this fuel were refined into biojet it would provide a 16% biojet-84% synjet blend. This allows the U.S. aviation industry to become carbon negative (carbon negative commercial aviation through carbon credits). Arid land recovery could yield even greater benefits.

  3. Carbon nanotubes buckypapers for potential transdermal drug delivery.

    PubMed

    Schwengber, Alex; Prado, Héctor J; Zilli, Darío A; Bonelli, Pablo R; Cukierman, Ana L

    2015-12-01

    Drug loaded buckypapers based on different types of carbon nanotubes (CNTs) were prepared and characterized in order to evaluate their potentialities for the design of novel transdermal drug delivery systems. Lab-synthesized CNTs as well as commercial samples were employed. Clonidine hydrochloride was used as model drug, and the influence of composition of the drug loaded buckypapers and processing variables on in vitro release profiles was investigated. To examine the influence of the drug nature the evaluation was further extended to buckypapers prepared with flurbiprofen and one type of CNTs, their selection being based on the results obtained with the former drug. Scanning electronic microscopy images indicated that the model drugs were finely dispersed on the CNTs. Differential scanning calorimetry, and X-ray diffraction pointed to an amorphous state of both drugs in the buckypapers. A higher degree of CNT-drug superficial interactions resulted in a slower release of the drug. These interactions were in turn affected by the type of CNTs employed (single wall or multiwall CNTs), their functionalization with hydroxyl or carboxyl groups, the chemical structure of the drug, and the CNT:drug mass ratio. Furthermore, the application of a second layer of drug free CNTs on the loaded buckypaper, led to decelerate the drug release and to reduce the burst effect. PMID:26354234

  4. Land use efficiency: anticipating future demand for land-sector greenhouse gas emissions abatement and managing trade-offs with agriculture, water, and biodiversity.

    PubMed

    Bryan, Brett A; Crossman, Neville D; Nolan, Martin; Li, Jing; Navarro, Javier; Connor, Jeffery D

    2015-11-01

    Competition for land is increasing, and policy needs to ensure the efficient supply of multiple ecosystem services from land systems. We modelled the spatially explicit potential future supply of ecosystem services in Australia's intensive agricultural land in response to carbon markets under four global outlooks from 2013 to 2050. We assessed the productive efficiency of greenhouse gas emissions abatement, agricultural production, water resources, and biodiversity services and compared these to production possibility frontiers (PPFs). While interacting commodity markets and carbon markets produced efficient outcomes for agricultural production and emissions abatement, more efficient outcomes were possible for water resources and biodiversity services due to weak price signals. However, when only two objectives were considered as per typical efficiency assessments, efficiency improvements involved significant unintended trade-offs for the other objectives and incurred substantial opportunity costs. Considering multiple objectives simultaneously enabled the identification of land use arrangements that were efficient over multiple ecosystem services. Efficient land use arrangements could be selected that meet society's preferences for ecosystem service provision from land by adjusting the metric used to combine multiple services. To effectively manage competition for land via land use efficiency, market incentives are needed that effectively price multiple ecosystem services. PMID:26147156

  5. Potential for Carbon Sequestration in Transplanted Salt Marshes

    NASA Astrophysics Data System (ADS)

    O'Brien, C.; Davis, J.; Currin, C.

    2014-12-01

    The photosynthetic uptake of atmospheric carbon dioxide (CO2) by tidal salt marshes results in the long-term storage of carbon in the sediment. In recent decades, pressures such as land-use change and sea level rise have significantly reduced the global extent of salt marshes and increased the need for restoration projects. Restored salt marshes have been shown to provide many of the same ecological and economic benefits as natural marshes, including fish habitat, pollution filtration, and shoreline stabilization. Given the high carbon sequestration capacity of tidal marshes, carbon storage is likely an additional benefit of restoration; however, the degree to which restored marshes achieve equivalency with natural marshes in terms of carbon burial has not been well-defined. In this study, annual carbon sequestration rates in transplanted marshes were estimated and belowground carbon stocks were compared in transplanted versus natural marshes. Sediment cores were collected from five transplanted Spartina alterniflora marshes of known age (12-38 years old) in the Newport River Estuary, NC and from two natural marshes of unknown age. Organic matter content was estimated using the loss on ignition method and carbon content was estimated based on previously established relationships. In transplanted marshes, the rate of carbon sequestration in the top 30 cm decreased with marsh age and ranged from 76.70 g C/m2/yr (38 year old marsh) to 212.83 g C/m2/yr (12 year old marsh). The natural marshes contained significantly larger carbon stocks in the top 30 cm (4534.61 - 7790.18 g C m-2) than the transplanted marshes (1822.97 - 3798.62 g C m-2). However, the annual sequestration rates in the transplanted marshes are similar to those observed by others in natural marshes, and therefore it is likely that over time restored marshes are capable of accreting belowground carbon stocks equivalent to those found in natural marshes.

  6. Carbon sequestration potential for forage and pasture systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grassland soils represent a large reservoir of organic and inorganic carbon. Regionally, grasslands are annual CO2 sources or sinks depending on crop and soil management, current soil organic carbon (SOC) concentration and climate. Land management changes (LMC) impact SOC sequestration rate, the du...

  7. CARBON STORAGE POTENTIAL OF SHORT ROTATION TROPICAL TREE PLANTATIONS

    EPA Science Inventory

    Forests are a major sin or car on an play an important role in the global carbon cycle. ot only do forests contain hugh amounts of carbon, they exchange it very actively with the atmosphere. xpanding the world's forests, therefore, may present an opportunity to increase the terre...

  8. Global potential of biospheric carbon management for climate mitigation.

    PubMed

    Canadell, Josep G; Schulze, E Detlef

    2014-01-01

    Elevated concentrations of atmospheric greenhouse gases (GHGs), particularly carbon dioxide (CO2), have affected the global climate. Land-based biological carbon mitigation strategies are considered an important and viable pathway towards climate stabilization. However, to satisfy the growing demands for food, wood products, energy, climate mitigation and biodiversity conservation-all of which compete for increasingly limited quantities of biomass and land-the deployment of mitigation strategies must be driven by sustainable and integrated land management. If executed accordingly, through avoided emissions and carbon sequestration, biological carbon and bioenergy mitigation could save up to 38 billion tonnes of carbon and 3-8% of estimated energy consumption, respectively, by 2050. PMID:25407959

  9. Assessment of the potential of urban organic carbon dynamics to off-set urban anthropogenic emissions

    NASA Astrophysics Data System (ADS)

    Gottschalk, P.; Churkina, G.; Wattenbach, M.; Cubasch, U.

    2010-12-01

    The impact of urban systems on current and future global carbon emissions has been a focus of several studies. Many mitigation options in terms of increasing energy efficiency are discussed. However, apart from technical mitigation potential urban systems also have a considerable biogenic potential to mitigate carbon through an optimized management of organic carbon pools of vegetation and soil. Berlin city area comprises almost 50% of areas covered with vegetation or largely covered with vegetation. This potentially offers various areas for carbon mitigation actions. To assess the mitigation potentials our first objective is to estimate how large current vegetation and soil carbon stocks of Berlin are. We use publicly available forest and soil inventories to calculate soil organic carbon of non-pervious areas and forest standing biomass carbon. This research highlights data-gaps and assigns uncertainty ranges to estimated carbon resources. The second objective is to assess the carbon mitigation potential of Berlin’s vegetation and soils using a biogeochemical simulation model. BIOME-BGC simulates carbon-, nitrogen- and water-fluxes of ecosystems mechanistically. First, its applicability for Berlin forests is tested at selected sites. A spatial application gives an estimate of current net carbon fluxes. The application of such a model allows determining the sensitivity of key ecosystem processes (e.g. carbon gains through photosynthesis, carbon losses through decomposition) towards external drivers. This information can then be used to optimise forest management in terms of carbon mitigation. Initial results of Berlin’s current carbon stocks and its spatial distribution and preliminary simulations results will be presented.

  10. Emission abatement system utilizing particulate traps

    DOEpatents

    Bromberg, Leslie; Cohn, Daniel R.; Rabinovich, Alexander

    2004-04-13

    Emission abatement system. The system includes a source of emissions and a catalyst for receiving the emissions. Suitable catalysts are absorber catalysts and selective catalytic reduction catalysts. A plasma fuel converter generates a reducing gas from a fuel source and is connected to deliver the reducing gas into contact with the absorber catalyst for regenerating the catalyst. A preferred reducing gas is a hydrogen rich gas and a preferred plasma fuel converter is a plasmatron. It is also preferred that the absorber catalyst be adapted for absorbing NO.sub.x.

  11. [Research on carbon reduction potential of electric vehicles for low-carbon transportation and its influencing factors].

    PubMed

    Shi, Xiao-Qing; Li, Xiao-Nuo; Yang, Jian-Xin

    2013-01-01

    Transportation is the key industry of urban energy consumption and carbon emissions. The transformation of conventional gasoline vehicles to new energy vehicles is an important initiative to realize the goal of developing low-carbon city through energy saving and emissions reduction, while electric vehicles (EV) will play an important role in this transition due to their advantage in energy saving and lower carbon emissions. After reviewing the existing researches on energy saving and emissions reduction of electric vehicles, this paper analyzed the factors affecting carbon emissions reduction. Combining with electric vehicles promotion program in Beijing, the paper analyzed carbon emissions and reduction potential of electric vehicles in six scenarios using the optimized energy consumption related carbon emissions model from the perspective of fuel life cycle. The scenarios included power energy structure, fuel type (energy consumption per 100 km), car type (CO2 emission factor of fuel), urban traffic conditions (speed), coal-power technologies and battery type (weight, energy efficiency). The results showed that the optimized model was able to estimate carbon emissions caused by fuel consumption more reasonably; electric vehicles had an obvious restrictive carbon reduction potential with the fluctuation of 57%-81.2% in the analysis of six influencing factors, while power energy structure and coal-power technologies play decisive roles in life-cycle carbon emissions of electric vehicles with the reduction potential of 78.1% and 81.2%, respectively. Finally, some optimized measures were proposed to reduce transport energy consumption and carbon emissions during electric vehicles promotion including improving energy structure and coal technology, popularizing energy saving technologies and electric vehicles, accelerating the battery R&D and so on. The research provides scientific basis and methods for the policy development for the transition of new energy vehicles

  12. Evaluation of Equipment Vulnerability and Potential Shock Hazards. [carbon fibers

    NASA Technical Reports Server (NTRS)

    Taback, I.

    1980-01-01

    The vulnerability of electric equipment to carbon fibers released from aircraft accidents is investigated and the parameters affecting vulnerability are discussed. The shock hazard for a hypothetical set of accidents is computed.

  13. Potential for Carbon Sequestration using Organic Amendments on Rangeland Soils

    NASA Astrophysics Data System (ADS)

    Ryals, R.; Silver, W. L.

    2009-12-01

    Managed rangelands represent a geographically large land-use footprint and thus have considerable potential to sequester carbon (C) in soil through changes in management practices. Organic amendments are frequently added to agricultural and rangeland soils in an effort to improve fertility and yield, yet little is known about their impact on greenhouse gas dynamics and soil biogeochemical dynamics, especially in rangeland soils. This research aims to explore the effects of organic amendments on soil chemical and physical properties, plant inputs, and soil C and N dynamics in managed rangeland ecosystems. Our research uses field manipulations at two Mediterranean grassland ecosystems replicated within and across bioclimatic zones: the Sierra Foothills Research and Extension Center (SFREC) in Browns Valley, CA and the Nicasio Native Grass Ranch in Nicasio, CA. Both sites are dominated by annual grasses and are moderately grazed by cattle. Three replicate blocks at each site contain 60m x 25m treatment plots (organic amendments and control) with 5m buffer strips. Organic amendments were applied at a level of 14 MgC/ha (equivalent to a 1.27cm surface dressing) at the beginning of the wet season (December 2008). During the wet season (October through June), carbon dioxide (CO2) flux was measured weekly using a LI-8100, while fluxes of methane (CH4) and nitrous oxide (N2O) were measured biweekly using static flux chambers. During the dry season (June through September), fluxes were measured biweekly and monthly, respectively. Soil organic C (SOC) and nitrogen (N) were measured prior to treatment and seven months following treatment at 0-10, 10-30, 30-50, and 50-100 cm depths. Soil moisture and temperature were measured continuously. Changes in oxidative and hydrolytic extracellular enzyme activities are also being explored. After the first year of management, both sites responded similarly to treatments in both trend and magnitude. For example, at SFREC, total soil

  14. The microbial carbon pump concept: Potential biogeochemical significance in the globally changing ocean

    NASA Astrophysics Data System (ADS)

    Legendre, Louis; Rivkin, Richard B.; Weinbauer, Markus G.; Guidi, Lionel; Uitz, Julia

    2015-05-01

    Three vertical ocean carbon pumps have been known for almost three decades to sequester atmospheric carbon in the deep-water and sediment reservoirs, i.e. the solubility pump, the carbonate pump, and the soft-tissue (also known as organic, or biological) carbon pump (BCP). These three pumps maintain the vertical gradient in total dissolved inorganic carbon between the surface and deep waters. The more recently proposed microbial carbon pump (MCP) would maintain a gradient between short- and long-lived dissolved organic carbon (DOC; average lifetimes of <100 and >100 years, respectively). Long-lived DOC is an additional proposed reservoir of sequestered carbon in the ocean. This review: examines critically aspects of the vertical ocean carbon pumps and the MCP, in particular their physical dimensions and their potential roles in carbon sequestration; normalises the dimensions of the MCP to allow direct comparisons with the three vertical ocean carbon pumps; compares the MCP and vertical ocean carbon pumps; organises in a coherent framework the information available in the literature on refractory DOC; explores the potential effects of the globally changing ocean on the MCP; and identifies the assumptions that generally underlie the MCP studies, as bases for future research. The study: proposes definitions of terms, expressions and concepts related to the four ocean carbon pumps (i.e. three vertical pumps and MCP); defines the magnitude for the MCP as the rate of production of DOC with an average lifetime of >100 years and provides its first estimate for the World Ocean, i.e. 0.2 Pg C year-1; and introduces an operational "first-time-sequestration" criterion that prevents organic carbon fluxes from being assigned to both the BCP and the MCP. In our review of the potential effects of predicted climate-related changes in the ocean environment on the MCP, we found that three of the seven predicted changes could potentially enhance carbon sequestration by the MCP, and

  15. Topographic variability influences the carbon sequestration potential of arable soils

    NASA Astrophysics Data System (ADS)

    Chirinda, N.; Elsgaard, L.; Thomsen, I. K.; Lægdsmand, M.; Heckrath, G.; Petersen, B. M.; Olesen, JE

    2012-04-01

    There is presently limited knowledge on the influence of field spatial variability on the carbon (C) sink-source relationships in arable landscapes. This is accompanied by the fact that our understanding of soil profile C dynamics is also limited. This study aimed at investigating how spatial variability along a short catena influences C sink-source relationships and temporal dynamics of CO2 concentrations in soils. In spring 2011, soil samples were collected from topsoil (2-5.5 cm) and subsoil (38-41.5 cm) horizons at upslope and footslope positions in a Danish winter wheat field on a sandy loam soil developed on glacial till. Bulk densities and C concentrations of the soils were characterized. From June 2011, gas samples were collected at least bimonthly from the same slope positions in four spatial replicates using stainless steel needles that were permanently installed at 5, 10, 20 and 30 cm soil depths. Concurrently, gas was sampled from 40, 50, and 80 cm depths using steel rods connected to a sampling port. Concentrations of CO2 in the gas samples were analyzed by gas chromatography. The results show that at the upslope position, soils from the topsoil horizon clearly had higher C pools (5.2 Mg C ha-1) compared to those from the subsoil horizon (1.0 Mg C ha-1). At the footslope position, however, C pools in topsoil (6.9 Mg C ha-1) and subsoil (7.0 C Mg ha-1) horizons were similar but higher than those at the upslope position. The gas monitoring study is still ongoing, but preliminary results show that CO2 concentrations generally increased with depth. At the upslope position, CO2 concentrations ranged between 800 and 24000 ppm and were generally lower than the concentrations observed at the footslope position (3000-42000 ppm) for similar soil depths. The upslope position has been subject to soil erosion while the footslope position has been a depositional site; thus the subsoil at the footslope position was to a large extent a buried topsoil horizon. The

  16. Determination of the atherogenic potential of inhaled carbon monoxide

    SciTech Connect

    Penn, A. )

    1993-05-01

    he effects of chronic exposure to moderate levels of carbon monoxide upon the augmentation of arteriosclerotic plaque development were investigated in a series of in vivo studies in the cockerel (young rooster). This animal model has been well characterized, especially regarding the role of environmental agents in exacerbating early stages of plaque development. Cockerels injected with subtumorigenic doses of carcinogens exhibit markedly accelerated development of aortic arteriosclerotic plaques. Inhalation of mainstream smoke from two packs of cigarettes (100 minutes/day for 16 weeks) causes small but statistically significant increases in plaque size. As is the case with many animal models of plaque development, raised fat-proliferative plaques also appear in these animals following cholesterol feeding. Carbon monoxide is a ubiquitous pollutant in urban environments, where it is derived largely from mobile sources and cigarette smoke. Exposure to chronically elevated carbon monoxide levels has been implicated in a number of health-related problems. Whether such exposure plays a role in the development of arteriosclerosis has not been determined conclusively. In the present study, three questions were posed: 1. Will inhaled carbon monoxide at levels of 50 to 200 parts per million (ppm)* (two hours/day for 16 weeks) be sufficient to augment arteriosclerotic plaque development in cockerels, in the absence of other plaque-promoting agents 2. Will the inhalation of 100 ppm carbon monoxide (two hours/day for 16 weeks), concomitant with the feeding of low levels (0.1%) of cholesterol, yield larger plaques than those obtained with either of these agents administered alone 3. Will inhalation of 100 ppm carbon monoxide (two hours/day for 11 or 22 weeks), by cockerels in whom plaques have already appeared, further augment plaque development Cockerels were exposed to carefully regulated levels of carbon monoxide in stainless-steel and Plexiglas dynamic exposure chambers.

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

    PubMed

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

    2012-02-01

    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) < 0.70) or Class C (R(50) < 0.50) recalcitrance/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. PMID:22242866

  18. An Index-Based Approach to Assessing Recalcitrance and Soil Carbon Sequestration Potential of Engineered Black Carbons (Biochars)

    SciTech Connect

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

    2012-01-10

    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{sub 50}, for assessing biochar quality for carbon sequestration is proposed. The R{sub 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{sub 50}, with biochar physicochemical properties and biochar-C mineralization revealed the existence of a quantifiable relationship between R{sub 50} and biochar recalcitrance. As presented here, the R{sub 50} is immediately applicable to pre-land application screening of biochars into Class A (R{sub 50} {>=} 0.70), Class B (0.50 {<=} R{sub 50} < 0.70) or Class C (R{sub 50} < 0.50) recalcitrance/carbon sequestration classes. Class A and Class C biochars would have carbon sequestration potential comparable to soot/graphite and uncharred plant biomass, respectively, while Class B biochars would have intermediate carbon sequestration potential. We believe that the coupling of the R{sub 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.

  19. Nitrogen oxide abatement by distributed fuel addition

    SciTech Connect

    Wendt, J.O.L.; Meraab, J.

    1988-03-25

    The purpose of this project is to develop techniques for nitrogen oxides abatement by distributed fuel addition. The major nitrogen oxide of interest is Nitric Oxide (NO), a precursor to premature forest damage and to acid rain. Recently interest has also been evoked with respect to an additional oxide of nitrogen, namely Nitrous Oxide (N{sub 2}O). Therefore, abatement measures for NO{sub x} are being investigated to determine their influence on N{sub 2}O as well. This report briefly describes the significance of N{sub 2}O emissions to the environment and the urgent need to develop techniques that can reduce emissions of both NO and N{sub 2}O. Reburning through distributed fuel addition may be an effective technique for NO{sub x} (mainly NO) emission control as described in the previous quarterly report. Reburning may also be effective in reducing N{sub 2}O levels. A technique for N{sub 2}O measurement by gas chromatography/electron capture detection was developed during this quarter, and is described in this report. This analysis technique will be used in the proposed experimental study to investigate the effectiveness of reburning on N{sub 2}O control.

  20. 29 CFR 4207.10 - Plan rules for abatement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 9 2013-07-01 2013-07-01 false Plan rules for abatement. 4207.10 Section 4207.10 Labor Regulations Relating to Labor (Continued) PENSION BENEFIT GUARANTY CORPORATION WITHDRAWAL LIABILITY FOR MULTIEMPLOYER PLANS REDUCTION OR WAIVER OF COMPLETE WITHDRAWAL LIABILITY § 4207.10 Plan rules for abatement. (a) General rule. Subject to...

  1. 47 CFR 22.971 - Obligation to abate unacceptable interference.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Obligation to abate unacceptable interference. 22.971 Section 22.971 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PUBLIC MOBILE SERVICES Cellular Radiotelephone Service § 22.971 Obligation to abate unacceptable interference. (a) Strict...

  2. 47 CFR 22.878 - Obligation to abate unacceptable interference.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Obligation to abate unacceptable interference. 22.878 Section 22.878 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service Commercial Aviation Air-Ground Systems § 22.878 Obligation to abate...

  3. ASBESTOS CONCENTRATIONS TWO YEARS AFTER ABATEMENT IN SEVENTEEN SCHOOLS

    EPA Science Inventory

    Airborne asbestos concentrations were measured at 17 schools that underwent an asbestos abatement 2 years before in 1988. These 17 schools, which involved 20 abatement sites, were part of a study conducted by the U.S. Environmental Protection Agency (EPA) and the New Jersey Depar...

  4. ASBESTOS CONCENTRATIONS IN TWO YEARS AFTER ABATEMENT IN SEVENTEEN SCHOOLS

    EPA Science Inventory

    Airborne asbestos concentrations were measured at 17 schools that underwent an asbestos abatement 2 years before in 1988. hese 17 schools, which involved 20 abatement sites, were part of a study conducted by the U.S Environmental Protection Agency (EPA) and the New Jersey Departm...

  5. 30 CFR 722.13 - Failure to abate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Failure to abate. 722.13 Section 722.13 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR INITIAL PROGRAM REGULATIONS ENFORCEMENT PROCEDURES § 722.13 Failure to abate. An authorized representative of the...

  6. 30 CFR 722.13 - Failure to abate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Failure to abate. 722.13 Section 722.13 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR INITIAL PROGRAM REGULATIONS ENFORCEMENT PROCEDURES § 722.13 Failure to abate. An authorized representative of the...

  7. 30 CFR 722.13 - Failure to abate.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Failure to abate. 722.13 Section 722.13 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR INITIAL PROGRAM REGULATIONS ENFORCEMENT PROCEDURES § 722.13 Failure to abate. An authorized representative of the...

  8. 30 CFR 722.13 - Failure to abate.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Failure to abate. 722.13 Section 722.13 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR INITIAL PROGRAM REGULATIONS ENFORCEMENT PROCEDURES § 722.13 Failure to abate. An authorized representative of the...

  9. 76 FR 67650 - Migratory Bird Permits; Abatement Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-02

    ... for a specific permit authorizing the use of raptors in abatement activities (76 FR 39368). The... the advance notice of proposed rulemaking, please refer to that document at 76 FR 39368 (July 6, 2011... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AW75 Migratory Bird Permits; Abatement...

  10. VISUAL INSPECTION AND AHERA CLEARANCE AT ASBESTOS ABATEMENT SITES

    EPA Science Inventory

    Asbestos abatement carried out in schools is subject to regulations under the Asbestos Hazard Emergency Response Act (AHERA) of 1986. The AHERA rule (40 CFR Part 763) specifies a bifactorial process for determining when an asbestos abatement site is clean enough for the primary ...

  11. VISUAL INSPECTION AND AHERA CLEARANCE AT ASBESTOS-ABATEMENT SITES

    EPA Science Inventory

    Asbestos abatement carried out in schools is subject to regulations under the Asbestos Hazard Emergency Response Act (AHERA) of 1986. he AHERA rule (40 CFR Part 763) specifies a bifactorial process for determining when an asbestos abatement site is clean enough for the primary co...

  12. 30 CFR 722.13 - Failure to abate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Failure to abate. 722.13 Section 722.13 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR INITIAL PROGRAM REGULATIONS ENFORCEMENT PROCEDURES § 722.13 Failure to abate. An authorized representative of the...

  13. Carbonate Precipitation through Microbial Activities in Natural Environment, and Their Potential in Biotechnology: A Review

    PubMed Central

    Zhu, Tingting; Dittrich, Maria

    2016-01-01

    Calcium carbonate represents a large portion of carbon reservoir and is used commercially for a variety of applications. Microbial carbonate precipitation, a by-product of microbial activities, plays an important metal coprecipitation and cementation role in natural systems. This natural process occurring in various geological settings can be mimicked and used for a number of biotechnologies, such as metal remediation, carbon sequestration, enhanced oil recovery, and construction restoration. In this study, different metabolic activities leading to calcium carbonate precipitation, their native environment, and potential applications and challenges are reviewed. PMID:26835451

  14. Carbonate Precipitation through Microbial Activities in Natural Environment, and Their Potential in Biotechnology: A Review.

    PubMed

    Zhu, Tingting; Dittrich, Maria

    2016-01-01

    Calcium carbonate represents a large portion of carbon reservoir and is used commercially for a variety of applications. Microbial carbonate precipitation, a by-product of microbial activities, plays an important metal coprecipitation and cementation role in natural systems. This natural process occurring in various geological settings can be mimicked and used for a number of biotechnologies, such as metal remediation, carbon sequestration, enhanced oil recovery, and construction restoration. In this study, different metabolic activities leading to calcium carbonate precipitation, their native environment, and potential applications and challenges are reviewed. PMID:26835451

  15. Coal reserves and resources as well as potentials for underground coal gasification in connection with carbon capture and storage (CCS)

    NASA Astrophysics Data System (ADS)

    Ilse, Jürgen

    2010-05-01

    . However, these otherwise unprofitable coal deposits can be mined economically by means of underground coal gasification, during which coal is converted into a gaseous product in the deposit. The synthesis gas can be used for electricity generation, as chemical base material or for the production of petrol. This increases the usability of coal resources tremendously. At present the CCS technologies (carbon capture and storage) are a much discussed alternative to other CO2 abatement techniques like efficiency impovements. The capture and subsequent storage of CO2 in the deposits created by the actual underground gasification process seem to be technically feasible.

  16. Preliminary Feasibility Assessment of Geologic Carbon Sequestration Potential for TVA's John Sevier and Kingston Power Plants

    SciTech Connect

    Smith, Ellen D; Saulsbury, Bo

    2008-03-01

    This is a preliminary assessment of the potential for geologic carbon sequestration for the Tennessee Valley Authority's (TVA) John Sevier and Kingston power plants. The purpose of this assessment is to make a 'first cut' determination of whether there is sufficient potential for geologic carbon sequestration within 200 miles of the plants for TVA and Oak Ridge National Laboratory (ORNL) to proceed with a joint proposal for a larger project with a strong carbon management element. This assessment does not consider alternative technologies for carbon capture, but assumes the existence of a segregated CO{sub 2} stream suitable for sequestration.

  17. Potential for Soil Carbon Sequestration in Central Kazakhstan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The World Bank Kazakhstan Drylands Management Project has the goal of restoring degraded soils associated with abandoned croplands in Kazakhstan. Global markets for carbon sequestration are likely to grow with continued implementation of international agreements such as Kyoto as well as those expec...

  18. Potential carbon dioxide fixation by industrially important microalgae.

    PubMed

    Sydney, Eduardo Bittencourt; Sturm, Wilerson; de Carvalho, Julio Cesar; Thomaz-Soccol, Vanete; Larroche, Christian; Pandey, Ashok; Soccol, Carlos Ricardo

    2010-08-01

    The present study aimed at investigating the carbon metabolism in terms of carbon dioxide fixation and its destination in microalgae cultivations. To this purpose, analysis of growth parameters, media of cultivation, biomass composition and productivity and nutrients balance were performed. Four microalgae suitable for mass cultivation were evaluated: Dunaliella tertiolecta SAD-13.86, Chlorella vulgaris LEB-104, Spirulina platensis LEB-52 and Botryococcus braunii SAG-30.81. Global rates of carbon dioxide and oxygen were determinated by a system developed in our laboratory. B. braunii presented the highest CO(2) fixation rate, followed by S. platensis,D. tertiolecta and C. vulgaris (496.98, 318.61, 272.4 and 251.64 mg L(-1)day(-1), respectively). Carbon dioxide fixated was mainly used for microalgal biomass production. Nitrogen, phosphorus (calcium for D. tertiolecta), potassium and magnesium consumption rates (mg gX(-1)) were evaluated for the four microalgae. Biomass composition presented a predominance of proteins but also a high amount of lipids, especially in D. tertiolecta and B. braunii. PMID:20350804

  19. Potential release scenarios for carbon nanotubes used in composites

    EPA Science Inventory

    The expected widespread use of carbon nanotube (CNT)-composites in consumer products calls for an assessment of the possible release and exposure to workers, consumers and the environment. Release of CNTs may occur at all steps in the life cycle of products, but to date only limi...

  20. Modeling carbon sequestration potential in Mollisols under climate change scenarios

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carbon sequestration in agricultural soils, besides its importance in mitigating global climate change, impacts and will be impacted by provisioning, regulating and supporting agroecosystem services. The objectives of this study were to (1) provide an improved understanding of the role of projected ...

  1. Carbon stocks and potential carbon storage in the mangrove forests of China.

    PubMed

    Liu, Hongxiao; Ren, Hai; Hui, Dafeng; Wang, Wenqing; Liao, Baowen; Cao, Qingxian

    2014-01-15

    Mangrove forests provide important ecosystem services, and play important roles in terrestrial and oceanic carbon (C) cycling. Although the C stocks or storage in terrestrial ecosystems in China have been frequently assessed, the C stocks in mangrove forests have often been overlooked. In this study, we estimated the C stocks and the potential C stocks in China's mangrove forests by combining our own field data with data from the National Mangrove Resource Inventory Report and from other published literature. The results indicate that mangrove forests in China store about 6.91 ± 0.57 Tg C, of which 81.74% is in the top 1 m soil, 18.12% in the biomass of mangrove trees, and 0.08% in the ground layer (i.e. mangrove litter and seedlings). The potential C stocks are as high as 28.81 ± 4.16 Tg C. On average, mangrove forests in China contain 355.25 ± 82.19 Mg C ha(-1), which is consistent with the global average of mangrove C density at similar latitudes, but higher than the average C density in terrestrial forests in China. Our results suggest that C storage in mangroves can be increased by selecting high C-density species for afforestation and stand improvement, and even more by increasing the mangrove area. The information gained in this study will facilitate policy decisions concerning the restoration of mangrove forests in China. PMID:24374165

  2. Estimating organic micro-pollutant removal potential of activated carbons using UV absorption and carbon characteristics.

    PubMed

    Zietzschmann, Frederik; Altmann, Johannes; Ruhl, Aki Sebastian; Dünnbier, Uwe; Dommisch, Ingvild; Sperlich, Alexander; Meinel, Felix; Jekel, Martin

    2014-06-01

    Eight commercially available powdered activated carbons (PAC) were examined regarding organic micro-pollutant (OMP) removal efficiencies in wastewater treatment plant (WWTP) effluent. PAC characteristic numbers such as B.E.T. surface, iodine number and nitrobenzene number were checked for their potential to predict the OMP removal of the PAC products. Furthermore, the PAC-induced removal of UV254 nm absorption (UVA254) in WWTP effluent was determined and also correlated with OMP removal. None of the PAC characteristic numbers can satisfactorily describe OMP removal and accordingly, these characteristics have little informative value on the reduction of OMP concentrations in WWTP effluent. In contrast, UVA254 removal and OMP removal correlate well for carbamazepine, diclofenac, and several iodinated x-ray contrast media. Also, UVA254 removal can roughly describe the average OMP removal of all measured OMP, and can accordingly predict PAC performance in OMP removal. We therefore suggest UVA254 as a handy indicator for the approximation of OMP removal in practical applications where direct OMP concentration quantification is not always available. In continuous operation of large-scale plants, this approach allows for the efficient adjustment of PAC dosing to UVA254, in order to ensure reliable OMP removal whilst minimizing PAC consumption. PMID:24651017

  3. [Estimation of soil carbon sequestration potential in typical steppe of Inner Mongolia and associated uncertainty].

    PubMed

    Wang, Wei; Wu, Jian-Guo; Han, Xing-Guo

    2012-01-01

    Based on the measurements in the enclosure and uncontrolled grazing plots in the typical steppe of Xilinguole, Inner Mongolia, this paper studied the soil carbon storage and carbon sequestration in the grasslands dominated by Leymus chinensis, Stipa grandis, and Stipa krylovii, respectively, and estimated the regional scale soil carbon sequestration potential in the heavily degraded grassland after restoration. At local scale, the annual soil carbon sequestration in the three grasslands all decreased with increasing year of enclosure. The soil organic carbon storage was significantly higher in the grasslands dominated by L. chinensis and Stipa grandis than in that dominated by Stipa krylovii, but the latter had much higher soil carbon sequestration potential, because of the greater loss of soil organic carbon during the degradation process due to overgrazing. At regional scale, the soil carbon sequestration potential at the depth of 0-20 cm varied from -0.03 x 10(4) to 3.71 x 10(4) kg C x a(-1), and the total carbon sequestration potential was 12.1 x 10(8) kg C x a(-1). Uncertainty analysis indicated that soil gravel content had less effect on the estimated carbon sequestration potential, but the estimation errors resulted from the spatial interpolation of climate data could be about +/- 4.7 x 10(9) kg C x a(-1). In the future, if the growth season precipitation in this region had an average variation of -3.2 mm x (10 a)(-1), the soil carbon sequestration potential would be de- creased by 1.07 x 10(8) kg C x (10 a)(-1). PMID:22489476

  4. CO2 abatement costs of greenhouse gas (GHG) mitigation by different biogas conversion pathways.

    PubMed

    Rehl, T; Müller, J

    2013-01-15

    Biogas will be of increasing importance in the future as a factor in reducing greenhouse gas emissions cost-efficiently by the optimal use of available resources and technologies. The goal of this study was to identify the most ecological and economical use of a given resource (organic waste from residential, commercial and industry sectors) using one specific treatment technology (anaerobic digestion) but applying different energy conversion technologies. Average and marginal abatement costs were calculated based on Life Cycle Cost (LCC) and Life Cycle Assessment (LCA) methodologies. Eight new biogas systems producing electricity, heat, gas or automotive fuel were analyzed in order to identify the most cost-efficient way of reducing GHG emissions. A system using a combined heat and power station (which is connected to waste treatment and digestion operation facilities and located nearby potential residential, commercial or industrial heat users) was found to be the most cost-efficient biogas technology for reducing GHG emissions. Up to € 198 per tonne of CO(2) equivalents can be saved by replacing the "business as usual" systems based on fossil resources with ones based on biogas. Limited gas injection (desulfurized and dried biogas, without compression and upgrading) into the gas grid can also be a viable option with an abatement cost saving of € 72 per tonne of CO(2) equivalents, while a heating plant with a district heating grid or a system based on biogas results in higher abatement costs (€ 267 and € 270 per tonne CO(2) eq). Results from all systems are significantly influenced by whether average or marginal data are used as a reference. Beside that energy efficiency, the reference system that was replaced and the by-products as well as feedstock and investment costs were identified to be parameters with major impacts on abatement costs. The quantitative analysis was completed by a discussion of the role that abatement cost methodology can play in

  5. Carbon budgets and potential blue carbon stores in Scotland's coastal and marine environment

    NASA Astrophysics Data System (ADS)

    Howe, John; austin, william

    2016-04-01

    The role of marine ecosystems in storing blue carbon has increasingly become a topic of interest to both scientists and politicians. This is the first multidisciplinary study to assess Scotland's marine blue carbon stores, using GIS to collate habitat information based on existing data. Relevant scientific information on primary habitats for carbon uptake and storage has been reviewed, and quantitative rates of production and storage were obtained. Habitats reviewed include kelp, phytoplankton, saltmarshes, biogenic reefs (including maerl), marine sediments (coastal and shelf), and postglacial geological sediments. Each habitat has been individually assessed for any specific threats to its carbon sequestration ability. Here we present an ecosystem-scale inventory of the key rates and ultimate sequestration capacity of each habitat. Coastal and offshore sediments are the main repositories for carbon in Scotland's marine environment. Habitat-forming species on the coast (seagrasses, saltmarsh, bivalve beds, coralline algae), are highly productive but their contribution to the overall carbon budget is very small because of the limited extent of each habitat. This study highlights the importance of marine carbon stores in global carbon cycles, and the implications of climate change on the ability of marine ecosystems to sequester carbon.

  6. Interleaved Carbon Minibeams: An Experimental Radiosurgery Method With Clinical Potential

    SciTech Connect

    Dilmanian, F. Avraham; Rusek, Adam; Fois, Giovanna R.; Olschowka, John; Desnoyers, Nicolle R.; Park, Jane Y.; Dioszegi, Istvan; Dane, Bari; Wang Ruiliang; Tomasi, Dardo; Lee, Hedok; Hurley, Sean D.; Coyle, Patricia K.; Meek, Allen G.; O'Banion, M. Kerry

    2012-10-01

    Purpose: To evaluate the efficacy of 'interleaved carbon minibeams' for ablating a 6.5-mm target in a rabbit brain with little damage to the surrounding brain. The method is based on the well-established tissue-sparing effect of arrays of thin planes of radiation. Methods and Materials: Broad carbon beams from the National Aeronautics and Space Agency Space Radiation Facility at Brookhaven National Laboratory were segmented into arrays of parallel, horizontal, 0.3-mm-thick planar beams (minibeams). The minibeams' gradual broadening in tissues resulted in 0.525-mm beam thickness at the target's proximal side in the spread-out Bragg peak. Interleaving was therefore implemented by choosing a 1.05 mm beam spacing on-center. The anesthetized rabbit, positioned vertically on a stage capable of rotating about a vertical axis, was exposed to arrays from four 90 Degree-Sign angles, with the stage moving up by 0.525 mm in between. This produced a solid radiation field at the target while exposing the nontargeted tissues to single minibeam arrays. The target 'physical' absorbed dose was 40.2 Gy. Results: The rabbit behaved normally during the 6-month observation period. Contrast magnetic resonance imaging and hematoxylin and eosin histology at 6 months showed substantial focal target damage with little damage to the surrounding brain. Conclusion: We plan to evaluate the method's therapeutic efficacy by comparing it with broad-beam carbon therapy in animal models. The method's merits would combine those of carbon therapy (i.e., tight target dose because of the carbon's Bragg-peak, sharp dose falloff, and high relative biological effectiveness at the target), together with the method's low impact on the nontargeted tissues. The method's smaller impact on the nontargeted brain might allow carbon therapy at higher target doses and/or lower normal tissue impact, thus leading to a more effective treatment of radioresistant tumors. It should also make the method more amenable to

  7. Carbon carry capacity and carbon sequestration potential in China based on an integrated analysis of mature forest biomass.

    PubMed

    Liu, YingChun; Yu, GuiRui; Wang, QiuFeng; Zhang, YangJian; Xu, ZeHong

    2014-12-01

    Forests play an important role in acting as a carbon sink of terrestrial ecosystem. Although global forests have huge carbon carrying capacity (CCC) and carbon sequestration potential (CSP), there were few quantification reports on Chinese forests. We collected and compiled a forest biomass dataset of China, a total of 5841 sites, based on forest inventory and literature search results. From the dataset we extracted 338 sites with forests aged over 80 years, a threshold for defining mature forest, to establish the mature forest biomass dataset. After analyzing the spatial pattern of the carbon density of Chinese mature forests and its controlling factors, we used carbon density of mature forests as the reference level, and conservatively estimated the CCC of the forests in China by interpolation methods of Regression Kriging, Inverse Distance Weighted and Partial Thin Plate Smoothing Spline. Combining with the sixth National Forest Resources Inventory, we also estimated the forest CSP. The results revealed positive relationships between carbon density of mature forests and temperature, precipitation and stand age, and the horizontal and elevational patterns of carbon density of mature forests can be well predicted by temperature and precipitation. The total CCC and CSP of the existing forests are 19.87 and 13.86 Pg C, respectively. Subtropical forests would have more CCC and CSP than other biomes. Consequently, relying on forests to uptake carbon by decreasing disturbance on forests would be an alternative approach for mitigating greenhouse gas concentration effects besides afforestation and reforestation. PMID:25424432

  8. Hydrology affects carbon storage potential of prairie potholes

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2013-06-01

    Prairie potholes, the small, dynamic, unconnected ponds that dot central Canada as well as parts of the north central United States, can store significant amounts of soil nutrients that can be transformed to carbon dioxide and other greenhouse gases. Scientists would like to better understand how these regions could contribute to climate warming, but there are challenges, given the large heterogeneity in greenhouse gas emissions over the prairie pothole landscape.

  9. The Lifestyle Carbon Dividend: Assessment of the Carbon Sequestration Potential of Grasslands and Pasturelands Reverted to Native Forests

    NASA Astrophysics Data System (ADS)

    Rao, S.; Jain, A. K.; Shu, S.

    2015-12-01

    What is the potential of a global transition to a vegan lifestyle to sequester carbon and mitigate climate change? To answer this question, we use an Earth System Model (ESM), the Integrated Science Assessment Model (ISAM). ISAM is a fully coupled biogeochemistry (carbon and nitrogen cycles) and biogeophysics (hydrology and thermal energy) ESM, which calculates carbon sources and sinks due to land cover and land use change activities, such as reforestation and afforestation. We calculate the carbon sequestration potential of grasslands and pasturelands that can be reverted to native forests as 265 GtC on 1.96E+7 km2 of land area, just 41% of the total area of such lands on Earth. The grasslands and pasturelands are assumed to revert back to native forests which existed prior to any human intervention and these include tropical, temperate and boreal forests. The results are validated with above ground regrowth measurements. Since this carbon sequestration potential is greater than the 240 GtC of that has been added to the atmosphere since the industrial era began, it shows that such global lifestyle transitions have tremendous potential to mitigate and even reverse climate change.

  10. Lead paint abatement -- A technological review

    SciTech Connect

    Draper, A.C. III; Kapuscik, D.

    1994-12-31

    Abatement of lead from various surfaces proves to be a rapidly developing industry. Removal techniques and effectiveness varies greatly with varying substrates (wood, concrete, steel, etc.) and surface configurations including interior/exterior considerations, habitability and anticipated retrofit. Numerous technologies advances, and/or adaptations of long accepted removal techniques have recently emerged. Some of the more commonly used removal procedures including vacuum blasting, chemical stripping, scarifiers, grinders, sanders, etc. will be reviewed. Specific emphasis will be placed upon mode of application, positive and negative environmental aspects, and varying emissions generated. Personnel sampling data will be discussed with respect to associated personal protective equipment impact to derive the most cost productive environmentally conscious alternatives.

  11. Properties and potential environmental applications of carbon adsorbents from waste tire rubber

    USGS Publications Warehouse

    Lehmann, C.M.B.; Rameriz, D.; Rood, M.J.; Rostam-Abadi, M.

    2000-01-01

    The properties of tire-derived carbon adsorbents (TDCA) produced from select tire chars were compared with those derived from an Illinois coal and pistachio nut shells. Chemical analyses of the TDCA indicated that these materials contain metallic elements not present in coal-and nut shell-derived carbons. These metals, introduced during the production of tire rubber, potentially catalyze steam gasification reactions of tire char. TDCA carbons contained larger meso-and macopore volumes than their counterparts derived from coal and nut shell (on the moisture-and ash-free-basis). Adsorptive properties of the tire-derived adsorbent carbons for air separation, gas storage, and gas clean up were also evaluated and compared with those of the coal-and nut shell derived carbons as well as a commercial activated carbon. The results revealed that TDCA carbons are suitable adsorbents for removing vapor-phase mercury from combustion flue gases and hazardous organic compounds from industrial gas streams.

  12. Use of glassy carbon as a working electrode in controlled potential coulometry.

    PubMed

    Plock, C E; Vasquez, J

    1969-11-01

    Glassy carbon has been used as the working electrode in controlled potential coulometry. The results of coulometric investigations of chromium, copper, iron, uranium and neptunium are compared with results obtained with platinum or mercury working electrodes. The accuracy of results with the glassy carbon electrode compares favourably with the results obtainable with the other electrodes, but the precision is poorer. PMID:18960665

  13. CONSERVATION AND SEQUESTRATION OF CARBON: THE POTENTIAL OF FOREST AND AGROFOREST MANAGEMENT PRACTICES

    EPA Science Inventory

    Forests play a major role in the Earth's carbon cycle through assimilation, storage, and emission of CO2. stablishment and management of boreal, temperate, and tropical forest and agroforest systems could potentially enhance sequestration of carbon in the terrestrial biosphere. i...

  14. Dissolved organic carbon and its potential predictors in eutrophic lakes.

    PubMed

    Toming, Kaire; Kutser, Tiit; Tuvikene, Lea; Viik, Malle; Nõges, Tiina

    2016-10-01

    Understanding of the true role of lakes in the global carbon cycle requires reliable estimates of dissolved organic carbon (DOC) and there is a strong need to develop remote sensing methods for mapping lake carbon content at larger regional and global scales. Part of DOC is optically inactive. Therefore, lake DOC content cannot be mapped directly. The objectives of the current study were to estimate the relationships of DOC and other water and environmental variables in order to find the best proxy for remote sensing mapping of lake DOC. The Boosted Regression Trees approach was used to clarify in which relative proportions different water and environmental variables determine DOC. In a studied large and shallow eutrophic lake the concentrations of DOC and coloured dissolved organic matter (CDOM) were rather high while the seasonal and interannual variability of DOC concentrations was small. The relationships between DOC and other water and environmental variables varied seasonally and interannually and it was challenging to find proxies for describing seasonal cycle of DOC. Chlorophyll a (Chl a), total suspended matter and Secchi depth were correlated with DOC and therefore are possible proxies for remote sensing of seasonal changes of DOC in ice free period, while for long term interannual changes transparency-related variables are relevant as DOC proxies. CDOM did not appear to be a good predictor of the seasonality of DOC concentration in Lake Võrtsjärv since the CDOM-DOC coupling varied seasonally. However, combining the data from Võrtsjärv with the published data from six other eutrophic lakes in the world showed that CDOM was the most powerful predictor of DOC and can be used in remote sensing of DOC concentrations in eutrophic lakes. PMID:27318445

  15. Carbon-enriched calcium carbide and its potential use

    SciTech Connect

    Ivakhnyuk, G.K.; Samonin, V.V.; Fedorov, N.F.; Vladimirov, V.A.; Stepanova, L.V.; Kas'yanova, O.M.

    1987-10-10

    The authors comparatively assess the feasibility of a variety of carbonaceous materials--lean coal, specialty coke, coal coke, semicoke, and coke residue from shale production--as raw materials for the production and carburization of calcium carbide and subsequently assess the value of the calcium carbide produced as a raw material in the production of graphite. They determine that calcium carbide enriched by their process is characterized by a high carbon content having the graphite structure and that the use of carburized calcium carbide allows for a significant increase in the output of graphite during low-temperature reaction of the carbide with magnesium chloride.

  16. Carbon sequestration potential of coastal wetland soils of Veracruz, Mexico

    NASA Astrophysics Data System (ADS)

    Fuentes-Romero, Elisabeth; García-Calderón, Norma Eugenia; Ikkonen, Elena; García-Varela, Kl

    2014-05-01

    Tropical coastal wetlands, including rainforests and mangrove ecosystems play an increasingly important ecological and economic role in the tropical coastal area of the State of Veracruz /Mexico. However, soil processes in these environments, especially C-turnover rates are largely unknown until today. Therefore, we investigated CO2 and CH4 emissions together with gains and losses of organic C in the soils of two different coastal ecosystems in the "Natural Protected Area Cienaga del Fuerte (NPACF)" near Tecolutla, in the State of Veracruz. The research areas were an artificially introduced grassland (IG) and a wetland rainforest (WRF). The gas emissions from the soil surfaces were measured by a static chamber array, the soil organic C was analysed in soil profiles distributed in the two areas, humic substances were characterized and C budget was calculated. The soils in both areas acted as carbon sinks, but the soils of the WRF sequestered more C than those of the IG, which showed a higher gas emission rate and produced more dissolved organic carbon. The gas emission measurements during the dry and the rainy seasons allowed for estimating the possible influence of global warming on gas fluxes from the soils of the two different ecological systems, which show in the WRF a quite complex spatial emission pattern during the rainy season in contrast to a more continuous emission pattern in the IG plots

  17. Investigation of Microbial Respirometry for Monitoring Natural Sulfide Abatement in Geothermal Cooling Tower Basins

    SciTech Connect

    Peter A. Pryfogle

    2005-09-01

    Geothermal plant operators are interested in investigating the ability of micro-organisms found in the cooling tower basin to metabolize and cycle sulfide to less toxic sulfur compounds. If the growth or activity of the organisms participating in sulfur-oxidation could be selectively enhanced, then hydrogen sulfide could be naturally abated in the cooling basin, substantially reducing the costs associated with the chemicals used for abatement. The use of respirometry has been proposed as a technique for monitoring the response of the microbial populations found in geothermal cooling towers to various conditions, including the addition of nutrients such as nitrogen and phosphorus. Respiro-metry is a manometric measurement of dissolved gases that are in equilibrium in a con-fined sample volume. Since microbes expire varying amounts of carbon dioxide or oxygen as they metabolize nutrients, this technique can be used to evaluate their activities in process streams. This report describes a series of experiments designed to determine the suitability of respirometry for tracking microbial activity for evaluating and enhancing natural abatement processes in geothermal cooling basins.

  18. Carbon sequestration potential of second-growth forest regeneration in the Latin American tropics.

    PubMed

    Chazdon, Robin L; Broadbent, Eben N; Rozendaal, Danaë M A; Bongers, Frans; Zambrano, Angélica María Almeyda; Aide, T Mitchell; Balvanera, Patricia; Becknell, Justin M; Boukili, Vanessa; Brancalion, Pedro H S; Craven, Dylan; Almeida-Cortez, Jarcilene S; Cabral, George A L; de Jong, Ben; Denslow, Julie S; Dent, Daisy H; DeWalt, Saara J; Dupuy, Juan M; Durán, Sandra M; Espírito-Santo, Mario M; Fandino, María C; César, Ricardo G; Hall, Jefferson S; Hernández-Stefanoni, José Luis; Jakovac, Catarina C; Junqueira, André B; Kennard, Deborah; Letcher, Susan G; Lohbeck, Madelon; Martínez-Ramos, Miguel; Massoca, Paulo; Meave, Jorge A; Mesquita, Rita; Mora, Francisco; Muñoz, Rodrigo; Muscarella, Robert; Nunes, Yule R F; Ochoa-Gaona, Susana; Orihuela-Belmonte, Edith; Peña-Claros, Marielos; Pérez-García, Eduardo A; Piotto, Daniel; Powers, Jennifer S; Rodríguez-Velazquez, Jorge; Romero-Pérez, Isabel Eunice; Ruíz, Jorge; Saldarriaga, Juan G; Sanchez-Azofeifa, Arturo; Schwartz, Naomi B; Steininger, Marc K; Swenson, Nathan G; Uriarte, Maria; van Breugel, Michiel; van der Wal, Hans; Veloso, Maria D M; Vester, Hans; Vieira, Ima Celia G; Bentos, Tony Vizcarra; Williamson, G Bruce; Poorter, Lourens

    2016-05-01

    Regrowth of tropical secondary forests following complete or nearly complete removal of forest vegetation actively stores carbon in aboveground biomass, partially counterbalancing carbon emissions from deforestation, forest degradation, burning of fossil fuels, and other anthropogenic sources. We estimate the age and spatial extent of lowland second-growth forests in the Latin American tropics and model their potential aboveground carbon accumulation over four decades. Our model shows that, in 2008, second-growth forests (1 to 60 years old) covered 2.4 million km(2) of land (28.1% of the total study area). Over 40 years, these lands can potentially accumulate a total aboveground carbon stock of 8.48 Pg C (petagrams of carbon) in aboveground biomass via low-cost natural regeneration or assisted regeneration, corresponding to a total CO2 sequestration of 31.09 Pg CO2. This total is equivalent to carbon emissions from fossil fuel use and industrial processes in all of Latin America and the Caribbean from 1993 to 2014. Ten countries account for 95% of this carbon storage potential, led by Brazil, Colombia, Mexico, and Venezuela. We model future land-use scenarios to guide national carbon mitigation policies. Permitting natural regeneration on 40% of lowland pastures potentially stores an additional 2.0 Pg C over 40 years. Our study provides information and maps to guide national-level forest-based carbon mitigation plans on the basis of estimated rates of natural regeneration and pasture abandonment. Coupled with avoided deforestation and sustainable forest management, natural regeneration of second-growth forests provides a low-cost mechanism that yields a high carbon sequestration potential with multiple benefits for biodiversity and ecosystem services. PMID:27386528

  19. Carbon sequestration potential of second-growth forest regeneration in the Latin American tropics

    PubMed Central

    Chazdon, Robin L.; Broadbent, Eben N.; Rozendaal, Danaë M. A.; Bongers, Frans; Zambrano, Angélica María Almeyda; Aide, T. Mitchell; Balvanera, Patricia; Becknell, Justin M.; Boukili, Vanessa; Brancalion, Pedro H. S.; Craven, Dylan; Almeida-Cortez, Jarcilene S.; Cabral, George A. L.; de Jong, Ben; Denslow, Julie S.; Dent, Daisy H.; DeWalt, Saara J.; Dupuy, Juan M.; Durán, Sandra M.; Espírito-Santo, Mario M.; Fandino, María C.; César, Ricardo G.; Hall, Jefferson S.; Hernández-Stefanoni, José Luis; Jakovac, Catarina C.; Junqueira, André B.; Kennard, Deborah; Letcher, Susan G.; Lohbeck, Madelon; Martínez-Ramos, Miguel; Massoca, Paulo; Meave, Jorge A.; Mesquita, Rita; Mora, Francisco; Muñoz, Rodrigo; Muscarella, Robert; Nunes, Yule R. F.; Ochoa-Gaona, Susana; Orihuela-Belmonte, Edith; Peña-Claros, Marielos; Pérez-García, Eduardo A.; Piotto, Daniel; Powers, Jennifer S.; Rodríguez-Velazquez, Jorge; Romero-Pérez, Isabel Eunice; Ruíz, Jorge; Saldarriaga, Juan G.; Sanchez-Azofeifa, Arturo; Schwartz, Naomi B.; Steininger, Marc K.; Swenson, Nathan G.; Uriarte, Maria; van Breugel, Michiel; van der Wal, Hans; Veloso, Maria D. M.; Vester, Hans; Vieira, Ima Celia G.; Bentos, Tony Vizcarra; Williamson, G. Bruce; Poorter, Lourens

    2016-01-01

    Regrowth of tropical secondary forests following complete or nearly complete removal of forest vegetation actively stores carbon in aboveground biomass, partially counterbalancing carbon emissions from deforestation, forest degradation, burning of fossil fuels, and other anthropogenic sources. We estimate the age and spatial extent of lowland second-growth forests in the Latin American tropics and model their potential aboveground carbon accumulation over four decades. Our model shows that, in 2008, second-growth forests (1 to 60 years old) covered 2.4 million km2 of land (28.1% of the total study area). Over 40 years, these lands can potentially accumulate a total aboveground carbon stock of 8.48 Pg C (petagrams of carbon) in aboveground biomass via low-cost natural regeneration or assisted regeneration, corresponding to a total CO2 sequestration of 31.09 Pg CO2. This total is equivalent to carbon emissions from fossil fuel use and industrial processes in all of Latin America and the Caribbean from 1993 to 2014. Ten countries account for 95% of this carbon storage potential, led by Brazil, Colombia, Mexico, and Venezuela. We model future land-use scenarios to guide national carbon mitigation policies. Permitting natural regeneration on 40% of lowland pastures potentially stores an additional 2.0 Pg C over 40 years. Our study provides information and maps to guide national-level forest-based carbon mitigation plans on the basis of estimated rates of natural regeneration and pasture abandonment. Coupled with avoided deforestation and sustainable forest management, natural regeneration of second-growth forests provides a low-cost mechanism that yields a high carbon sequestration potential with multiple benefits for biodiversity and ecosystem services. PMID:27386528

  20. Bragg gratings in carbon coated optical fibers and their potential sensor applications in harsh environment

    NASA Astrophysics Data System (ADS)

    Li, Yaowen; Kudelko, David J.; Hokansson, Adam S.; Simoff, Debra A.; Stolov, Andrei A.; Ng, Joanna; Mann, Joel

    2014-05-01

    We have demonstrated that fiber Bragg gratings can be written through the carbon layer of carbon-coated optical fibers having different coating thicknesses. Specifically, grating index modulation amplitudes of ~2.5x10-5 and 0.52x10-5 were obtained in optical fibers having carbon layers 29 nm and 56 nm thick, respectively, without any extra photosensitization of the fibers. Subsequent experimental results showed that the carbon coatings in the grating areas didn't change their hermetic properties. Finally, we describe the advantages of these gratings and their potential applications in fiber optic sensing.

  1. Conservation and sequestration of carbon: The potential of forest and agroforest management practices

    SciTech Connect

    Dixon, R.K.; Winjum, J.K.; Schroeder, P.E.

    1993-01-01

    Forests play a major role in the Earth's carbon cycle through assimilation, storage, and emission of CO2. Establishment and management of boreal, temperate, and tropical forest and agroforest systems could potentially enhance sequestration of carbon in the terrestrial biosphere. A biologic and economic analysis of forest establishment and management options from 94 nations revealed that forestation, agroforestry, and silviculture could be employed to conserve and sequester one gigaton (Gt) of carbon annually over a 50 year period. The marginal cost of implementing these options to sequester 55 Gt of carbon would be approximately $10/ton.

  2. Soil carbon sequestration in degraded semiarid agro-ecosystems--perils and potentials.

    PubMed

    Olsson, Lennart; Ardö, Jonas

    2002-09-01

    The Kyoto Protocol opens new possibilities for using the biosphere as a carbon sink. Using agro-ecosystems as carbon sinks may be the most appropriate practice from both environmental and socioeconomic points of view. Degraded agro-ecosystems in Africa might benefit significantly from the improved land management that would be part of a carbon sequestration program. There are vast areas of these agro-ecosystems in Africa and their rehabilitation is an urgent matter. We agree with UNEP that there are potentially important synergies to be made between the Convention on Climate Change, the UN Convention to Combat Desertification and the UN Convention on Biodiversity. In this paper, we have investigated the potential for increasing soil carbon content in semiarid agro-ecosystems in the Sudan and found that increasing fallow periods will result in increased soil carbon content and converting marginal agricultural areas to rangeland will restore the carbon levels to 80% of the natural savannah carbon levels in 100 years. The economic gain from a future carbon sequestration program has the potential of a significant contribution to the household economy in these agro-ecosystems. PMID:12436845

  3. NO{sub x} Emission Abatement Technologies

    SciTech Connect

    Goles, R

    1991-10-01

    The Hanford Waste Vitrification Plant (HWVP) will convert Hanford Site high-level liquid defense waste to a solid vitrified (glass) form suitable for final disposal in a geological repository. Future process flow sheet developments may establish a need for a NO, scrubber in the melter off-gas system. Consequently, a technology review has been conducted to identify and compare applicable off-gas processing alternatives should NO, emission abatement be required. Denitrification processes can be separated into two distinct categories, wet or dry, depending upon whether or not NO{sub x} is absorbed into an aqueous solution. The dry methods of removal are generally more efficient (>90%) than wet scrubbing approaches (>60%); however, most dry approaches are applicable only to NO,. Of the dry removal methods, selective catalytic reduction (SCR) using NH3 reductant and a hydrogen zeolite catalyst appears to be the most suitable technology for reducing HWVP NO{sub x} emissions should emission abatement be required. SCR is a relatively simple, well established technology that produces no secondary waste stream and is applicable to a wide range of NO{sub x} concentrations (500 to 30,000 ppm). This technology has been successfully applied to uranium dissolver exhaust streams and has, more recently, been tested and evaluated as the best available control technology for reducing NO, emissions at the Idaho National Engineering Laboratory's waste calciner facility, and at DOE's West Valley Demonstration Project. Unlike dry NO, scrubbing methods, the wet techniques are not specific to NO{sub x}, so they may support the process in more than one way. This is the only major advantage associated with wet technologies. Their disadvantages are that they are not highly efficient at low NO{sub x} concentrations, they produce a secondary waste stream, and they may require complex chemical support to reduce equipment size. Wet scrubbing of HWVP process NO{sub x} emissions is an option that

  4. 47 CFR 22.971 - Obligation to abate unacceptable interference.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SERVICES PUBLIC MOBILE SERVICES Cellular Radiotelephone Service § 22.971 Obligation to abate unacceptable... licensee that can show that its signal does not directly or indirectly, cause or contribute to...

  5. A METHOD FOR COMPARING MULTICOMPONENT, MULTIMEDIA POLLUTION ABATEMENT PROCESSES

    EPA Science Inventory

    The paper describes a comparison of the cost-effectiveness of four multicomponent, multimedia pollution abatement options: coal cleaning, limestone, limestone plus adipic acid, and coal cleaning plus limestone plus adipic acid. The comparison makes cost-effectiveness evaluations ...

  6. Potential Occupational Risks Associated with Pulmonary Toxicity of Carbon Nanotubes

    PubMed Central

    Manke, Amruta; Luanpitpong, Sudjit; Rojanasakul, Yon

    2014-01-01

    Given their remarkable properties, carbon nanotubes (CNTs) have made their way through various industrial and medicinal applications and the overall production of CNTs is expected to grow rapidly in the next few years, thus requiring an additional recruitment of workers. However, their unique applications and desirable properties are fraught with concerns regarding occupational exposure. The concern about worker exposure to CNTs arises from the results of recent animal studies. Short-term and sub-chronic exposure studies in rodents have shown consistent adverse health effects such as pulmonary inflammation, granulomas, fibrosis, genotoxicity and mesothelioma after inhalation or instillation of several types of CNTs. Furthermore, physicochemical properties of CNTs such as dispersion, functionalization and particle size can significantly affect their pulmonary toxicity. Risk estimates from animal studies necessitate implementation of protective measures to limit worker exposure to CNTs. Information on workplace exposure is very limited, however, studies have reported that CNTs can be aerosolized and attain respirable airborne levels during synthesis and processing activities in the workplace. Quantitative risk assessments from sub-chronic animal studies recommend the health-based need to reduce exposures below the recommended exposure limit of 1 µg/m3. Practice of prevention measures including the use of engineering controls, personal protective equipment, health surveillance program, safe handling and use, as well as worker training can significantly minimize worker exposure and improve worker health and safety. PMID:25621290

  7. Soil carbon storage and respiration potential across a landscape age and climate gradient in western Greenland

    NASA Astrophysics Data System (ADS)

    Bradley-Cook, J. I.; Virginia, R. A.; Hammond Wagner, C.; Racine, P. E.

    2013-12-01

    The soil formation state factors proposed by Hans Jenny (climate, organisms, relief, parent material, time) explain many soil characteristics, yet geological controls on biological carbon cycling are not well represented in regional carbon models. Landscape age, for instance, can directly affect the quantity and quality of soil organic carbon, which are key determinants of the temperature sensitivity of soil organic matter (SOM) to decomposition. Temperature control of SOM decomposition is of particular importance in Arctic soils, which contain nearly half of global belowground organic carbon and have a permafrost thermal regime that straddles the freeze-thaw threshold. We investigated soil carbon storage and respiration potential across a west Greenland transect, and related the landscape carbon patterns to regional variation in climate and landscape age. The four study sites capture a range in: landscape age from 180 years on the inland Little Ice Age moraine near Kangerlussuaq to ~10,000 years at the coastal sites near Sisimiut and Nuuk, mean annual air temperatures from -5.7 to -1.4 °C, and mean annual precipitation from 149 to 752 mm. At each site, we collected surface and mineral samples from nine soil pits within similar vegetation cover and relief classes. We measured total organic carbon and nitrogen though elemental analysis, and incubated soils at 4 °C and field capacity moisture for 175 day to measure carbon dioxide production from which we derived soil respiration potential. We hypothesized that soil carbon storage and respiration potential would be greatest at the sites with the oldest landscape age. Soil carbon content was more than four times greater at the 10,000 year sites (Nuuk = 24.03%, Sisimiut = 17.34%) than the inland sites (Ørkendalen = 3.49%, LIA = 0.05%). Carbon quality decreased across the age gradient, as measured by a nearly two-fold increase in C:N ratio from the youngest and driest to the oldest and wettest soils (LIA = 12.2, Nuuk

  8. A Comparison of Lead Abatement Technologies at Lewis Research Center

    NASA Technical Reports Server (NTRS)

    Jeziorowski, Luz Y.; Calla, Joanne

    1997-01-01

    In 1995, Lewis participated in a pilot test of Lead Specifications. The Specifications were sponsored by the Center to Protect Worker's Rights (CPWR). Entitled "Model Specifications for the Protection of Worker's from Lead on Steel Structures", one aspect of this endeavor was to test and compare several lead abatement technologies. The project overview, objectives, team, and requirements as well as abatement methods and materials are outlined.

  9. Post-Soviet farmland abandonment, forest recovery, and carbon storage potential in Ukraine

    NASA Astrophysics Data System (ADS)

    Olofsson, P.; Kuemmerle, T.; Baumann, M.; Radeloff, V. C.; Woodcock, C. E.; Hostert, P.

    2010-12-01

    Land use is a critical factor in the global carbon cycle, but land use effects on carbon fluxes are poorly understood in many regions. One such region is the former Eastern Bloc, where land use intensity decreased substantially after the collapse of the Soviet Union, resulting in widespread farmland abandonment and forest regrowth. The aim of this study was to examine how land use trends altered net carbon fluxes in Western Ukraine (57,000 km2) for the communist (1945-1991) and the post-communist period (1991-2007), and to assess the regions’ future carbon sequestration potential. Forest disturbance and farmland abandonment between 1988 to 2007 was estimated from Landsat imagery in former study. Historical land use change rates were obtained from forest inventories to reconstruct forest trends back to the mid-1800s. Using a carbon book-keeping model, we quantified net carbon fluxes from land use change and assessed potential future carbon fluxes for a range of reforestation and logging scenarios. Our results suggest that the low-point in forest cover occurred in the 1920s. Forest expansion in the second half of the 20th century turned the region from a carbon source to a sink, despite heavy logging during Soviet times. The current land-use related sink strength is about 1.5 Tg of carbon per year. Sequestration potential on abandoned farmland is enormous, even when assuming that only a minor fraction of the currently abandoned land will revert to forests. Beyond our study area, farmland abandonment has been widespread throughout Eastern Europe and the former Soviet Union, suggesting that a substantial proportion of the regions’ industrial carbon emissions may be offset by reforesting farmland.

  10. The Veterans Administration's Asbestos Abatement Program

    SciTech Connect

    Schepers, G.W. )

    1991-12-31

    The Veterans Administration has developed a program of asbestos abatement for its more than 1000 buildings, where health care personnel from 173 hospitals and 238 ambulatory care clinics are likely to encounter respirable asbestos. This is a costly program, which has averaged about $25 million annually for the past ten years. The VA has banned the use of new asbestos products containing more than 1% of asbestos in building construction or renovation projects. Industrial hygiene engineering programs have been ordered instituted at all VA medical centers to monitor dust levels in compliance with OSHA and EPA requirements. Health surveillance programs, managed by an environmental health physician at each medical center, have been instituted for all personnel who have been identified to have breathed asbestos fibers in excess of OSHA-EPA threshold limit values. The health care program focuses on the identification of asbestosis and asbestos-related cancer through periodic X-ray films, lung function tests, and electrocardiographic and physical examination screening. The program also stresses cessation of smoking.

  11. Nitrogen oxide abatement by distributed fuel addition

    SciTech Connect

    Wendt, J.O.L.; Meraab, J.

    1988-06-27

    This research is directed towards the development of engineering guidelines that define the application of distributed fuel addition as a technique for NOx abatement. It is expected that multiple fuel and air addition in the post-flame of a combustion process will increase free radical concentrations which destroy nitrogenous species and thus help them decay toward their equilibrium concentrations, which can be very low in that region of the combustor. Screening experiments were conducted on a laboratory scale downfired combustor. The objective was to compare NOx emissions arising from various combustion configurations, including fuel and/or air staging. Although the primary focus of this research is on NO control, a secondary effort was directed towards the measurement of N2O emissions from various coal combustion processes. N2O has been identified as a trace gas responsible for stratospheric ozone depletion, and has been hypothesized to arise from combustion processes, in amounts roughly proportional to NO emissions. Results presented in this report showed that the ratio N2O/NO was far from constant. The introduction of secondary air into a combustion process was accompanied an increase in N2O emissions. The measured N2O was always less than 10 ppm even under the most favorable combustion conditions. Reburning with premixed fuel and air mixtures was not effective in reducing NO emissions.

  12. Geologic Carbon Sequestration: Leakage Potential and Policy Implications

    NASA Astrophysics Data System (ADS)

    Bielicki, J. M.; Peters, C. A.; Fitts, J. P.; Wilson, E. J.

    2014-12-01

    The geologic reservoirs that could be used for long-term sequestration of carbon dioxide (CO2) may have natural or manmade pathways that allow injected CO2, or the brine it displaces, to leak into overlying formations. Using a basin-scale leakage estimation model, we investigated the geophysical parameters that govern this leakage, and the resulting accumulations of leaked fluids in overlying formations. The results are discussed in the context of two polices aimed at governing long-term sequestration and protecting groundwater: the U.S. DOE guideline for storage permanence and the U.S. EPA UIC Program Class VI Rule. For a case study of CO2 injection into the Mt. Simon sandstone in the Michigan sedimentary basin, we showed that (1) the U.S. DOE guideline would allow for more leakage from larger injection projects than for smaller ones; (2) leakage amounts are determined mostly by well leakage permeability rather than by variation in formation permeabilities; (3) numerous leaking wells with anomalously high leakage permeabilities are necessary in order to achieve substantial leakage rates; (4) leakage can reach potable groundwater but intervening stratigraphic traps reduce the amount to be multiple orders of magnitude less than the leakage out of the reservoir, and (5) this leakage can reduce the Area of Review that is defined by the U.S. EPA as the area within which leakage can threaten groundwater. In summary, leakage that exceeds the U.S. DOE storage permanence goal would occur only under extreme conditions, the amount that reaches shallow potable groundwater may be inconsequential from a pollution standpoint, and leakage may be beneficial. Future federal policies should be harmonized to achieve the dual goals of protecting groundwater while allowing for adaptive management that incorporates uncertainties and imperfections inherent in geologic reservoirs.

  13. The GABA transaminase, ABAT, is essential for mitochondrial nucleoside metabolism

    PubMed Central

    Besse, Arnaud; Wu, Ping; Bruni, Francesco; Donti, Taraka; Graham, Brett H.; Craigen, William J.; McFarland, Robert; Moretti, Paolo; Lalani, Seema; Scott, Kenneth L.; Taylor, Robert W.; Bonnen, Penelope E.

    2015-01-01

    Summary ABAT is a key enzyme responsible for catabolism of principal inhibitory neurotransmitter gamma-aminobutyric acid (GABA). We report an essential role for ABAT in a seemingly unrelated pathway, mitochondrial nucleoside salvage, and demonstrate that mutations in this enzyme cause an autosomal recessive neurometabolic disorder and mtDNA depletion syndrome (MDS). We describe a family with encephalomyopathic MDS caused by a homozygous missense mutation in ABAT that results in elevated GABA in subjects’ brains as well as decreased mtDNA levels in subjects’ fibroblasts. Nucleoside rescue and co-IP experiments pinpoint that ABAT functions in the mitochondrial nucleoside salvage pathway to facilitate conversion of dNDPs to dNTPs. Pharmacological inhibition of ABAT through the irreversible inhibitor Vigabatrin caused depletion of mtDNA in photoreceptor cells that was prevented through addition of dNTPs in cell culture media. This work reveals ABAT as a connection between GABA metabolism and nucleoside metabolism and defines a neurometabolic disorder that includes MDS. PMID:25738457

  14. Physically Based Simulation of Potential Effects of Carbon Dioxide Altered Climates on Groundwater Recharge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increased concentrations of atmospheric carbon-dioxide (CO2) will alter regional rainfall and potential evapotranspiration regimes that drive groundwater recharge. Improved methods are needed for assessing the potential sensitivities of the soil-water-vegetation system to climate change. This study ...

  15. Spatial optimization of carbon-stocking projects across Africa integrating stocking potential with co-benefits and feasibility.

    PubMed

    Greve, Michelle; Reyers, Belinda; Mette Lykke, Anne; Svenning, Jens-Christian

    2013-01-01

    Carbon offset projects through forestation are employed within the emissions trading framework to store carbon. Yet, information about the potential of landscapes to stock carbon, essential to the design of offset projects, is often lacking. Here, based on data on vegetation carbon, climate and soil, we quantify the potential for carbon storage in woody vegetation across tropical Africa. The ability of offset projects to produce co-benefits for ecosystems and people is then quantified. When co-benefits such as biodiversity conservation are considered, the top-ranked sites are sometimes different to sites selected purely for their carbon-stocking potential, although they still possess up to 92% of the latter carbon-stocking potential. This work provides the first continental-scale assessment of which areas may provide the greatest direct and indirect benefits from carbon storage reforestation projects at the smallest costs and risks, providing crucial information for prioritization of investments in carbon storage projects. PMID:24352139

  16. Spatial optimization of carbon-stocking projects across Africa integrating stocking potential with co-benefits and feasibility

    NASA Astrophysics Data System (ADS)

    Greve, Michelle; Reyers, Belinda; Mette Lykke, Anne; Svenning, Jens-Christian

    2013-12-01

    Carbon offset projects through forestation are employed within the emissions trading framework to store carbon. Yet, information about the potential of landscapes to stock carbon, essential to the design of offset projects, is often lacking. Here, based on data on vegetation carbon, climate and soil, we quantify the potential for carbon storage in woody vegetation across tropical Africa. The ability of offset projects to produce co-benefits for ecosystems and people is then quantified. When co-benefits such as biodiversity conservation are considered, the top-ranked sites are sometimes different to sites selected purely for their carbon-stocking potential, although they still possess up to 92% of the latter carbon-stocking potential. This work provides the first continental-scale assessment of which areas may provide the greatest direct and indirect benefits from carbon storage reforestation projects at the smallest costs and risks, providing crucial information for prioritization of investments in carbon storage projects.

  17. Potential climate change effects on rice: Carbon dioxide and temperature

    SciTech Connect

    Baker, J.T.; Boote, K.J.; Allen, L.H. Jr. |

    1995-12-31

    The projected doubling of current levels of atmospheric CO{sub 2} concentration [CO{sub 2}] during the next century, along with increases in other radiatively active gases, has led to predictions of increases in global air temperature and shifts in precipitation patterns. Since 1987, several [CO{sub 2}] and temperature experiments have been conducted on rice (Oryza sativa L., cv. IR-30) in outdoor, naturally-sunlit, environmentally-controlled, plant growth chambers. The objectives of this chapter are to summarize some of the major findings of these experiments. In these experiments, season-long [CO{sub 2}] treatments ranged from 160 to 900 {micro}mol CO{sub 2} mol{sup {minus}1} air, while temperature treatments ranged from 25/18/21 to 40/33/37 C (daytime dry bulb air temperature/nighttime dry bulb air temperature/constant paddy water temperature). Total growth duration was shortened by 10 to 12 d as [CO{sub 2}] increased across a [CO{sub 2}] range from 160 to 500 {micro}mol mol{sup {minus}1}, due mainly to a shortened vegetative phase of development and a reduction in the number of mainstem leaves formed prior to panicle initiation. Photosynthesis, growth, and final grain yield increased with [CO{sub 2}] from 160 to 500 {micro}mol mol{sup {minus}1}, but were very similar from 500 to 900 {micro}mol mol{sup {minus}1}. Carbon dioxide enrichment from 330 to 660 {micro}mol mol{sup {minus}1} increased grain yield mainly by increasing the number of panicles per plant, and increasing temperature treatment above 28/21/25 C resulted in decreased grain yield, due largely to a decline in the number of filled grain per panicle. Evapotranspiration decreased and water-use efficiency increased with increasing [CO{sub 2}] treatment, while the reverse trends were found with increasing temperature treatment. 60 refs., 7 figs., 2 tabs.

  18. Development of an assessment methodology for hydrocarbon recovery potential using carbon dioxide and associated carbon sequestration-Workshop findings

    USGS Publications Warehouse

    Verma, Mahendra K.; Warwick, Peter D.

    2011-01-01

    The Energy Independence and Security Act of 2007 (Public Law 110-140) authorized the U.S. Geological Survey (USGS) to conduct a national assessment of geologic storage resources for carbon dioxide (CO2) and requested that the USGS estimate the "potential volumes of oil and gas recoverable by injection and sequestration of industrial carbon dioxide in potential sequestration formations" (121 Stat. 1711). The USGS developed a noneconomic, probability-based methodology to assess the Nation's technically assessable geologic storage resources available for sequestration of CO2 (Brennan and others, 2010) and is currently using the methodology to assess the Nation's CO2 geologic storage resources. Because the USGS has not developed a methodology to assess the potential volumes of technically recoverable hydrocarbons that could be produced by injection and sequestration of CO2, the Geologic Carbon Sequestration project initiated an effort in 2010 to develop a methodology for the assessment of the technically recoverable hydrocarbon potential in the sedimentary basins of the United States using enhanced oil recovery (EOR) techniques with CO2 (CO2-EOR). In collaboration with Stanford University, the USGS hosted a 2-day CO2-EOR workshop in May 2011, attended by 28 experts from academia, natural resource agencies and laboratories of the Federal Government, State and international geologic surveys, and representatives from the oil and gas industry. The geologic and the reservoir engineering and operations working groups formed during the workshop discussed various aspects of geology, reservoir engineering, and operations to make recommendations for the methodology.

  19. Use of multi-transition-metal-ion-exchanged zeolite 13X catalysts in methane emissions abatement

    SciTech Connect

    Hui, K.S.; Chao, C.Y.H.; Kwong, C.W.; Wan, M.P.

    2008-04-15

    Methane is a potent greenhouse gas. It has a global warming potential (GWP) 23 times greater than carbon dioxide. Reducing methane emissions would lead to substantial economic and environmental benefits. This study investigated the performance of multi-transition-metal-(Cu, Cr, Ni, and Co)-ion-exchanged zeolite 13X catalysts in methane emissions abatement. The catalytic activity in methane combustion using multi-ion-exchanged catalysts was studied with different parameters including the molar percentage of metal loading, the space velocity, and the inlet methane concentration under atmospheric pressure and at a relatively low reaction temperature of 500 C. The performance of the catalysts was determined in terms of the apparent activation energy, the number of active sites of the catalyst, and the BET surface area of the catalyst. This study showed that multi-ion-exchanged catalysts outperformed single-ion-exchanged and acidified 13X catalysts and that lengthening the residence time led to a higher methane conversion percentage. The enhanced catalytic activity in the multi-ion-exchanged catalysts was attributed to the presence of exchanged transition ions instead of acid sites in the catalyst. The catalytic activity of the catalysts was influenced by the metal loading amount, which played an important role in affecting the apparent activation energy for methane combustion, the active sites, and the BET surface area of the catalyst. Increasing the amount of metal loading in the catalyst decreased the apparent activation energy for methane combustion and also the BET surface area of the catalyst. An optimized metal loading amount at which the highest catalytic activity was observed due to the combined effects of the various factors was determined. (author)

  20. Direct Carbon Conversion: Review of Production and Electrochemical Conversion of Reactive Carbons, Economics and Potential Impact on the Carbon Cycle

    SciTech Connect

    Cooper, J F; Cherepy, N; Upadhye, R; Pasternak, A; Steinberg, M

    2000-12-12

    Concerns over global warning have motivated the search for more efficient technologies for electric power generation from fossil fuels. Today, 90% of electric power is produced from coal, petroleum or natural gas. Higher efficiency reduces the carbon dioxide emissions per unit of electric energy. Exercising an option of deep geologic or ocean sequestration for the CO{sub 2} byproduct would reduce emissions further and partially forestall global warming. We introduce an innovative concept for conversion of fossil fuels to electricity at efficiencies in the range of 70-85% (based on standard enthalpy of the combustion reaction). These levels exceed the performance of common utility plants by up to a factor of two. These levels are also in excess of the efficiencies of combined cycle plants and of advanced fuel cells now operated on the pilot scale. The core of the concept is direct carbon conversion a process that is similar to that a fuel cell but differs in that synthesized forms of carbon, not hydrogen, are used as fuel. The cell sustains the reaction, C + O{sub 2} = CO{sub 2} (E {approx} 1.0 V, T = 800 C). The fuel is in the form of fine particulates ({approx}100 nm) distributed by entrainment in a flow of CO{sub 2} to the cells to form a slurry of carbon in the melt. The byproduct stream of CO{sub 2} is pure. It affords the option of sequestration without additional separation costs, or can be reused in secondary oil or gas recovery. Our experimental program has discovered carbon materials with orders of magnitude spreads in anode reactivity reflected in cell power density. One class of materials yields energy at about 1 kW/m{sup 2} sufficiently high to make practical the use of the cell in electric utility applications. The carbons used in such cells are highly disordered on the nanometer scale (2-30 nm), relative to graphite. Such disordered or turbostratic carbons can be produced by controlled pyrolysis (thermal decomposition) of hydrocarbons extracted from

  1. The potential for damage from the accidental release of conductive carbon fibers from aircraft composites

    NASA Technical Reports Server (NTRS)

    Bell, V. L.

    1980-01-01

    Carbon and graphite fibers are known to be electrically conductive. The rapidly accelerating use of carbon fibers as the reinforcement in filamentary composite materials brought up the possibility of accidental release of carbon fibers from the burning of crashed commercial airliners with carbon composite parts. Such release could conceivably cause widespread damage to electrical and electronic equipment. The experimental and analytical results of a comprehensive investigation of the various elements necessary to assess the extent of such potential damage in terms of annual expected costs and maximum losses at low probabilities of occurrence are presented. A review of NASA materials research program to provide alternate or modified composite materials to overcome any electrical hazards from the use of carbon composites in aircraft structures is described.

  2. Loess Plateau check dams can potentially sequester eroded soil organic carbon

    NASA Astrophysics Data System (ADS)

    Zhang, Haicheng; Liu, Shuguang; Yuan, Wenping; Dong, Wenjie; Xia, Jiangzhou; Cao, Yaojun; Jia, Yanwei

    2016-06-01

    Check dams are special soil and water conservation structures in the Loess Plateau, China. They play an important role in intercepting sediments and soil organic carbon (SOC). However, the decomposition of intercepted SOC and the environmental regulations at check dams have not been investigated. We conducted several paired field experiments at both check dams and slope lands in the Yanhe Watershed of the Loess Plateau to examine the characteristics of SOC decomposition at check dams. On average, the SOC mineralization rate in slope lands was approximately three times higher than in check dams. Increased soil moisture and compaction in check dams can constrain carbon mineralization by limiting the oxygen availability of SOC and can isolate substrate carbon from heterotrophic microorganisms. Our results indicate that check dams display a considerable potential for eroded SOC sequestration via reducing the soil respiration rate and highlight the important implications of lateral carbon redistribution and human engineering projects when estimating regional or global ecosystem carbon cycles.

  3. Black carbon from the Mississippi River: quantities, sources, and potential implications for the global carbon cycle.

    PubMed

    Mitra, Siddhartha; Bianchi, Thomas S; McKee, Brent A; Sutula, Martha

    2002-06-01

    Black carbon (BC) may be a major component of riverine carbon exported to the ocean, but its flux from large rivers is unknown. Furthermore, the global distribution of BC between natural and anthropogenic sources remains uncertain. We have determined BC concentrations in suspended sediments of the Mississippi River, the 7th largest river in the world in terms of sediment and water discharge, during high flow and low flow in 1999. The 1999 annual flux of BC from the Mississippi River was 5 x 10(-4) petagrams (1 Pg = 10(15) g = 1 gigaton). We also applied a principal components analysis to particulate-phase high molecular weight polycyclic aromatic hydrocarbon isomer ratios in Mississippi River suspended sediments. In doing so, we determined that approximately 27% of the BC discharged from the Mississippi River in 1999 originated from fossil fuel combustion (coal and smelter-derived combustion), implicating fluvial BC as an important source of anthropogenic BC contamination into the ocean. Using our value for BC flux and the annual estimate for BC burial in ocean sediments, we calculate that, in 1999, the Mississippi River discharged approximately 5% of the BC buried annually in the ocean. These results have important implications, not only for the global carbon cycle but also for the fluvial discharge of particulate organic contaminants into the world's oceans. PMID:12075780

  4. Integrated geologic and engineering determination of oil-reserve-growth potential in carbonate reservoirs

    SciTech Connect

    Holtz, M.H.; Rupel, S.C.; Hocott, C.R. )

    1992-11-01

    Leonardian restricted-platform carbonate reservoirs in the Permian Basin in West Texas and southeastern New Mexico exhibit abnormally low recovery efficiencies. Cumulative production form these mature reservoirs is only 18% of the original oil in place (OOIP), or about one-half the average recovery efficiency of Permian Basin carbonate reservoirs. Low recovery efficiency is directly related to high degrees of vertical and lateral facies heterogeneity caused by high-frequency, cyclic sedimentation in low-energy, carbonate platform environments and by equally complex postdepositional diagenesis. This paper reports that because of their geologic complexity, these reservoirs have high reserve-growth potential.

  5. Potential biodiversity benefits from international programs to reduce carbon emissions from deforestation.

    PubMed

    Siikamäki, Juha; Newbold, Stephen C

    2012-01-01

    Deforestation is the second largest anthropogenic source of carbon dioxide emissions and options for its reduction are integral to climate policy. In addition to providing potentially low cost and near-term options for reducing global carbon emissions, reducing deforestation also could support biodiversity conservation. However, current understanding of the potential benefits to biodiversity from forest carbon offset programs is limited. We compile spatial data on global forest carbon, biodiversity, deforestation rates, and the opportunity cost of land to examine biodiversity conservation benefits from an international program to reduce carbon emissions from deforestation. Our results indicate limited geographic overlap between the least-cost areas for retaining forest carbon and protecting biodiversity. Therefore, carbon-focused policies will likely generate substantially lower benefits to biodiversity than a more biodiversity-focused policy could achieve. These results highlight the need to systematically consider co-benefits, such as biodiversity in the design and implementation of forest conservation programs to support international climate policy. PMID:22307280

  6. Oak Ridge Gaseous Diffusion Plant Biological Monitoring and Abatement Program for Mitchell Branch

    SciTech Connect

    Loar, J.M.; Adams, S.M.; Kszos, L.A.; Ryon, M.G.; Smith, J.G.; Southworth, G.R.; Stewart, A.J.

    1992-01-01

    A proposed Biological Monitoring and Abatement Program (BMAP) for the Oak Ridge Gaseous Diffusion Plant (ORGDP; currently the Oak Ridge K-25 Site) was prepared in December 1986, as required by the modified National Pollutant Discharge Elimination System (NPDES) permit that was issued on September 11, 1986. The effluent discharges to Mitchell Branch are complex, consisting of trace elements, organic chemicals, and radionuclides in addition to various conventional pollutants. Moreover, the composition of these effluent streams will be changing over time as various pollution abatement measures are implemented over the next several years. Although contaminant inputs to the stream originate primarily as point sources from existing plant operations, area sources, such as the classified burial grounds and the K-1407-C holding pond, can not be eliminated as potential sources of contaminants. The proposed BMAP consists of four tasks. These tasks include (1) ambient toxicity testing, (2) bioaccumulation studies, (3) biological indicator studies, and (4) ecological surveys of the benthic invertebrate and fish communities. BMAP will determine whether the effluent limits established for ORGDP protect the designated use of the receiving stream (Mitchell Branch) for growth and propagation of fish and aquatic life. Another objective of the program is to document the ecological effects resulting from various pollution abatement projects, such as the Central Neutralization Facility.

  7. Identification of root cause and abatement of vibration of monochromator.

    SciTech Connect

    Jendrzejczyk, J. A.

    1998-01-13

    Silicon crystal mirrors are used to reflect high-intensity X-ray beams. A large amount of heat is generated in each mirror. To minimize the effect of thermal expansion on the crystal mirrors, heat is removed by pumping liquid gallium (with a boiling point of 29.8 C) through passages in the crystal mirrors. During system operation, mirror motion should be kept to an acceptable level to avoid performance degradation. There are many potential sources of excitation to the crystal assembly; one such source is the flowing gallium. Two series of tests were performed earlier for a near-prototypical gallium cooling system (1-2). This paper describes a series of tests to measure the general vibration response characteristics of critical components in the monochromator system that contains the mirrors. The main objective of this work is to identify the root cause of vibration and to recommend general guidelines for abatement of vibration. This is achieved by performing many tests to understand the response characteristics under various conditions, by analysis of the response data, and by use of some theoretical considerations.

  8. Abatement of an aircraft exhaust plume using aerodynamic baffles.

    PubMed

    Bennett, Michael; Christie, Simon M; Graham, Angus; Garry, Kevin P; Velikov, Stefan; Poll, D Ian; Smith, Malcolm G; Mead, M Iqbal; Popoola, Olalekan A M; Stewart, Gregor B; Jones, Roderic L

    2013-03-01

    The exhaust jet from a departing commercial aircraft will eventually rise buoyantly away from the ground; given the high thrust/power (i.e., momentum/buoyancy) ratio of modern aero-engines, however, this is a slow process, perhaps requiring ∼ 1 min or more. Supported by theoretical and wind tunnel modeling, we have experimented with an array of aerodynamic baffles on the surface behind a set of turbofan engines of 124 kN thrust. Lidar and point sampler measurements show that, as long as the intervention takes place within the zone where the Coanda effect holds the jet to the surface (i.e., within about 70 m in this case), then quite modest surface-mounted baffles can rapidly lift the jet away from the ground. This is of potential benefit in abating both surface concentrations and jet blast downstream. There is also some modest acoustic benefit. By distributing the aerodynamic lift and drag across an array of baffles, each need only be a fraction of the height of a single blast fence. PMID:23343109

  9. Chemical abatement of acid mine drainage formation

    SciTech Connect

    Steven, J.

    1987-01-01

    Chemical and thermodynamic data were used to develop a unified model of hydroxo-, sulfato-, and bisulfato-iron complexes and their stability constants in iron-sulfate solutions. Free energy of formation for each ligand series species was hypothesized to be linear in ligand number because of supporting evidence from the literature. Laboratory tests on the inhibition of acid mine drainage bacteria were conducted. Benzoic acid, sorbic acid, and sodium lauryl sulfate at low concentrations (5 to 10 mg/liter) each effectively inhibited oxidation of ferrous iron in batch cultures of Thiobacillus ferrooxidans. The rate of chemical oxidation of ferrous iron in low-pH, sterile batch reactors was not substantially affected at the tested concentrations (5 to 50 mg/liter) of any of the compounds. Low-pH cultures of Thiobacillus thioxidans significantly increased zinc sulfide dissolution rates relative to sterile controls. Sodium lauryl sulfate, benzoic acid, and sorbic acid at concentrations of 10, 25, and 50 mg/liter, respectively, in identical low-pH, batch cultures of Thiobacillus thiooxidans, were sufficient for complete inhibition of bacterial zinc sulfide dissolution. Pilot-scale experiments on the abatement of acid mine drainage formation in both fresh and weathered pyritic coal refuse were also conducted. At doses of 0.5 g/kg and 5.0 g/kg in fresh and weathered refuse, respectively, sodium benzoate, potassium sorbate, and most significantly, sodium lauryl surface, reduced the rate of iron, sulfate, and acidity production in water-leached barrels of coal refuse material.

  10. Sinking jelly-carbon unveils potential environmental variability along a continental margin.

    PubMed

    Lebrato, Mario; Molinero, Juan-Carlos; Cartes, Joan E; Lloris, Domingo; Mélin, Frédéric; Beni-Casadella, Laia

    2013-01-01

    Particulate matter export fuels benthic ecosystems in continental margins and the deep sea, removing carbon from the upper ocean. Gelatinous zooplankton biomass provides a fast carbon vector that has been poorly studied. Observational data of a large-scale benthic trawling survey from 1994 to 2005 provided a unique opportunity to quantify jelly-carbon along an entire continental margin in the Mediterranean Sea and to assess potential links with biological and physical variables. Biomass depositions were sampled in shelves, slopes and canyons with peaks above 1000 carcasses per trawl, translating to standing stock values between 0.3 and 1.4 mg C m(2) after trawling and integrating between 30,000 and 175,000 m(2) of seabed. The benthopelagic jelly-carbon spatial distribution from the shelf to the canyons may be explained by atmospheric forcing related with NAO events and dense shelf water cascading, which are both known from the open Mediterranean. Over the decadal scale, we show that the jelly-carbon depositions temporal variability paralleled hydroclimate modifications, and that the enhanced jelly-carbon deposits are connected to a temperature-driven system where chlorophyll plays a minor role. Our results highlight the importance of gelatinous groups as indicators of large-scale ecosystem change, where jelly-carbon depositions play an important role in carbon and energy transport to benthic systems. PMID:24367499

  11. Sinking Jelly-Carbon Unveils Potential Environmental Variability along a Continental Margin

    PubMed Central

    Lebrato, Mario; Molinero, Juan-Carlos; Cartes, Joan E.; Lloris, Domingo; Mélin, Frédéric; Beni-Casadella, Laia

    2013-01-01

    Particulate matter export fuels benthic ecosystems in continental margins and the deep sea, removing carbon from the upper ocean. Gelatinous zooplankton biomass provides a fast carbon vector that has been poorly studied. Observational data of a large-scale benthic trawling survey from 1994 to 2005 provided a unique opportunity to quantify jelly-carbon along an entire continental margin in the Mediterranean Sea and to assess potential links with biological and physical variables. Biomass depositions were sampled in shelves, slopes and canyons with peaks above 1000 carcasses per trawl, translating to standing stock values between 0.3 and 1.4 mg C m2 after trawling and integrating between 30,000 and 175,000 m2 of seabed. The benthopelagic jelly-carbon spatial distribution from the shelf to the canyons may be explained by atmospheric forcing related with NAO events and dense shelf water cascading, which are both known from the open Mediterranean. Over the decadal scale, we show that the jelly-carbon depositions temporal variability paralleled hydroclimate modifications, and that the enhanced jelly-carbon deposits are connected to a temperature-driven system where chlorophyll plays a minor role. Our results highlight the importance of gelatinous groups as indicators of large-scale ecosystem change, where jelly-carbon depositions play an important role in carbon and energy transport to benthic systems. PMID:24367499

  12. Potential threshold of anode materials for foldable lithium-ion batteries featuring carbon nanotube current collectors

    NASA Astrophysics Data System (ADS)

    Wang, Qing Hui; Zhong, Sheng Wen; Hu, Jing Wei; Liu, Ting; Zhu, Xian Yan; Chen, Jing; Hong, Yin Yan; Wu, Zi Ping

    2016-04-01

    Flexible carbon nanotube macro-films (CMFs) are perfect current collectors for preparing foldable lithium-ion batteries (LIBs). However, selecting appropriate anodes for electrode is difficult because of the different potentials (vs. Li/Li+) of carbon nanotubes and traditional metallic current collector. This study demonstrated an additional reaction at potential below 0.9 V (vs. Li/Li+) caused by CMF, And Li+ will be constrained, which decreased capacity of anode/CMF electrode. Conversely, results changed when the anode potential exceeded 0.9 V (vs. Li/Li+) because Li+ passed the potential threshold, and the CMF retained its electrochemical inactivity. Consequently, the CMF-based foldable LIBs performed well. The potential threshold mechanism of anode is expected to provide new impetus to both academia and industry for exploring flexible or foldable LIBs.

  13. Evaluation of Fibrogenic Potential of Industrial Multi-Walled Carbon Nanotubes in Acute Aspiration Experiment

    PubMed Central

    Khaliullin, T. O.; Shvedova, A. A.; Kisin, E. R.; Zalyalov, R. R.; Fatkhutdinova, L. M.

    2015-01-01

    Local inflammatory response in the lungs and fibrogenic potential of multi-walled carbon nanotubes were studied in an acute aspiration experiment in mice. The doses were chosen based on the concentration of nanotubes in the air at a workplace of the company-producer. ELISA, flow cytometry, enhanced darkfield microscopy, and histological examination showed that multi-walled carbon nanotubes induced local inflammation, oxidative stress, and connective tissue growth (fibrosis). Serum levels of TGF-β1 and osteopontin proteins can serve as potential exposure biomarkers. PMID:25778660

  14. Mechanisms controlling soil carbon turnover and their potential application for enhancing carbon sequestration

    SciTech Connect

    Jastrow, Julie D.; Amonette, James E.; Bailey, Vanessa L.

    2007-01-01

    Two major mechanisms, (bio)chemical alteration and physicochemical protection, stabilize soil organic carbon (SOC) and thereby control soil carbon turnover. With (bio)chemical alteration, SOC is transformed by biotic and abiotic processes to chemical forms that are more resistant to decomposition and, in some cases, more easily retained by sorption to soil solids. With physicochemical protection, biochemical attack of SOC is inhibited by organomineral interactions at molecular to millimeter scales. Stabilization of otherwise decomposable SOM can occur via sorption to soil surfaces, complexation with soil minerals, occlusion within aggregates, and deposition in pores inaccessible to decomposers and extracellular enzymes. Soil structure (i.e., the arrangement of solids and pores in the soil) is a master integrating variable that both controls and indicates the SOC stabilization status of a soil. To enhance SOC sequestration, the best option is to modify the soil physicochemical environment to favor the activities of fungi. Specific practices that accomplish this include minimizing tillage, maintaining a near-neutral soil pH and an adequate base cation exchange capacity (particularly Ca), ensuring adequate drainage, and minimizing erosion by water and wind. In some soils, amendments with various high-specific-surface micro- and mesoporous sorbents such as fly ash or charcoal can be beneficial.

  15. Evaluation of the potential for operating carbon neutral WWTPs in China.

    PubMed

    Hao, Xiaodi; Liu, Ranbin; Huang, Xin

    2015-12-15

    Carbon neutrality is starting to become a hot topic for wastewater treatment plants (WWTPs) all over the world, and carbon neutral operations have emerged in some WWTPs. Although China is still struggling to control its water pollution, carbon neutrality will definitely become a top priority for WWTPs in the near future. In this review, the potential for operating carbon neutral WWTPs in China is technically evaluated. Based on the A(2)/O process of a typical municipal WWTP, an evaluation model is first configured, which couples the COD/nutrient removals (mass balance) with the energy consumption/recovery (energy balance). This model is then applied to evaluate the potential of the organic (COD) energy with regards to carbon neutrality. The model's calculations reveal that anaerobic digestion of excess sludge can only provide some 50% of the total amount of energy consumption. Water source heat pumps (WSHP) can effectively convert the thermal energy contained in wastewater to heat WWTPs and neighbourhood buildings, which can supply a net electrical equivalency of 0.26 kWh when 1 m(3) of the effluent is cooled down by 1 °C. Photovoltaic (PV) technology can generate a limited amount of electricity, barely 10% of the total energy consumption. Moreover, the complexity of installing solar panels on top of tanks makes PV technology almost not worth the effort. Overall, therefore, organic and thermal energy sources can effectively supply enough electrical equivalency for China to approach to its target with regards to carbon neutral operations. PMID:26072280

  16. Global economic potential for reducing carbon dioxide emissions from mangrove loss

    PubMed Central

    Siikamäki, Juha; Sanchirico, James N.; Jardine, Sunny L.

    2012-01-01

    Mangroves are among the most threatened and rapidly disappearing natural environments worldwide. In addition to supporting a wide range of other ecological and economic functions, mangroves store considerable carbon. Here, we consider the global economic potential for protecting mangroves based exclusively on their carbon. We develop unique high-resolution global estimates (5′ grid, about 9 × 9 km) of the projected carbon emissions from mangrove loss and the cost of avoiding the emissions. Using these spatial estimates, we derive global and regional supply curves (marginal cost curves) for avoided emissions. Under a broad range of assumptions, we find that the majority of potential emissions from mangroves could be avoided at less than $10 per ton of CO2. Given the recent range of market price for carbon offsets and the cost of reducing emissions from other sources, this finding suggests that protecting mangroves for their carbon is an economically viable proposition. Political-economy considerations related to the ability of doing business in developing countries, however, can severely limit the supply of offsets and increases their price per ton. We also find that although a carbon-focused conservation strategy does not automatically target areas most valuable for biodiversity, implementing a biodiversity-focused strategy would only slightly increase the costs. PMID:22847435

  17. Global economic potential for reducing carbon dioxide emissions from mangrove loss.

    PubMed

    Siikamäki, Juha; Sanchirico, James N; Jardine, Sunny L

    2012-09-01

    Mangroves are among the most threatened and rapidly disappearing natural environments worldwide. In addition to supporting a wide range of other ecological and economic functions, mangroves store considerable carbon. Here, we consider the global economic potential for protecting mangroves based exclusively on their carbon. We develop unique high-resolution global estimates (5' grid, about 9 × 9 km) of the projected carbon emissions from mangrove loss and the cost of avoiding the emissions. Using these spatial estimates, we derive global and regional supply curves (marginal cost curves) for avoided emissions. Under a broad range of assumptions, we find that the majority of potential emissions from mangroves could be avoided at less than $10 per ton of CO(2). Given the recent range of market price for carbon offsets and the cost of reducing emissions from other sources, this finding suggests that protecting mangroves for their carbon is an economically viable proposition. Political-economy considerations related to the ability of doing business in developing countries, however, can severely limit the supply of offsets and increases their price per ton. We also find that although a carbon-focused conservation strategy does not automatically target areas most valuable for biodiversity, implementing a biodiversity-focused strategy would only slightly increase the costs. PMID:22847435

  18. Development of a carbonate platform with potential for large discoveries - an example from Vietnam

    SciTech Connect

    Mayall, M.; Bent, A.; Dale, B. )

    1996-01-01

    In offshore central and southern Vietnam a number of carbonate accumulations can be recognized. Platform carbonates form basin-wide units of carbonate characterized by strong, continuous parallel seismic reflectors. Facies are dominated by bioclastic wackestones with poor-moderate reservoir quality. On the more isolated highs, large buildups developed. These are typically 5-10 km across and 300 m thick. They unconformably overlie the platform carbonate facies which are extensively karstified. In places these are pinnacles, typically 2-5 km across, 300 m+ thick with chaotic or mounded internal seismic facies. The large carbonate buildups are characterized by steep sided slopes with talus cones, reef-margin rims usually developed around only part of the buildup, and a prominent back-stepping geometry. Buildup interior facies form the main potential reservoirs They are dominated by fine to coarse grained coralgal packstones. Fine grained carbonates are associated with deeper water events and multiple karst surfaces can also be identified. Reservoir quality is excellent, largely controlled by extensive dissolution and dolomitization believed to be related to the exposure events. Gas has been found in a number of reservoirs. Heterogeneities can be recognized which could potentially effect production. These include the extensive finer grained facies, cementation or open fissures associated with the karst surfaces, a more cemented reef rim, shallowing upwards facies cycles and faults.

  19. Development of a carbonate platform with potential for large discoveries - an example from Vietnam

    SciTech Connect

    Mayall, M.; Bent, A.; Dale, B.

    1996-12-31

    In offshore central and southern Vietnam a number of carbonate accumulations can be recognized. Platform carbonates form basin-wide units of carbonate characterized by strong, continuous parallel seismic reflectors. Facies are dominated by bioclastic wackestones with poor-moderate reservoir quality. On the more isolated highs, large buildups developed. These are typically 5-10 km across and 300 m thick. They unconformably overlie the platform carbonate facies which are extensively karstified. In places these are pinnacles, typically 2-5 km across, 300 m+ thick with chaotic or mounded internal seismic facies. The large carbonate buildups are characterized by steep sided slopes with talus cones, reef-margin rims usually developed around only part of the buildup, and a prominent back-stepping geometry. Buildup interior facies form the main potential reservoirs They are dominated by fine to coarse grained coralgal packstones. Fine grained carbonates are associated with deeper water events and multiple karst surfaces can also be identified. Reservoir quality is excellent, largely controlled by extensive dissolution and dolomitization believed to be related to the exposure events. Gas has been found in a number of reservoirs. Heterogeneities can be recognized which could potentially effect production. These include the extensive finer grained facies, cementation or open fissures associated with the karst surfaces, a more cemented reef rim, shallowing upwards facies cycles and faults.

  20. Mineral Carbonation Potential of CO2 from Natural and Industrial-based Alkalinity Sources

    NASA Astrophysics Data System (ADS)

    Wilcox, J.; Kirchofer, A.

    2014-12-01

    Mineral carbonation is a Carbon Capture and Storage (CSS) technology where gaseous CO2 is reacted with alkaline materials (such as silicate minerals and alkaline industrial wastes) and converted into stable and environmentally benign carbonate minerals (Metz et al., 2005). Here, we present a holistic, transparent life cycle assessment model of aqueous mineral carbonation built using a hybrid process model and economic input-output life cycle assessment approach. We compared the energy efficiency and the net CO2 storage potential of various mineral carbonation processes based on different feedstock material and process schemes on a consistent basis by determining the energy and material balance of each implementation (Kirchofer et al., 2011). In particular, we evaluated the net CO2 storage potential of aqueous mineral carbonation for serpentine, olivine, cement kiln dust, fly ash, and steel slag across a range of reaction conditions and process parameters. A preliminary systematic investigation of the tradeoffs inherent in mineral carbonation processes was conducted and guidelines for the optimization of the life-cycle energy efficiency are provided. The life-cycle assessment of aqueous mineral carbonation suggests that a variety of alkalinity sources and process configurations are capable of net CO2 reductions. The maximum carbonation efficiency, defined as mass percent of CO2 mitigated per CO2 input, was 83% for CKD at ambient temperature and pressure conditions. In order of decreasing efficiency, the maximum carbonation efficiencies for the other alkalinity sources investigated were: olivine, 66%; SS, 64%; FA, 36%; and serpentine, 13%. For natural alkalinity sources, availability is estimated based on U.S. production rates of a) lime (18 Mt/yr) or b) sand and gravel (760 Mt/yr) (USGS, 2011). The low estimate assumes the maximum sequestration efficiency of the alkalinity source obtained in the current work and the high estimate assumes a sequestration efficiency

  1. Carbon storage potential by four macrophytes as affected by planting diversity in a created wetland.

    PubMed

    Means, Mary M; Ahn, Changwoo; Korol, Alicia R; Williams, Lisa D

    2016-01-01

    Wetland creation has become a commonplace method for mitigating the loss of natural wetlands. Often mitigation projects fail to restore ecosystem services of the impacted natural wetlands. One of the key ecosystem services of newly created wetlands is carbon accumulation/sequestration, but little is known about how planting diversity (PD) affects the ability of herbaceous wetland plants to store carbon in newly created wetlands. Most mitigation projects involve a planting regime, but PD, which may be critical in establishing biologically diverse and ecologically functioning wetlands, is seldom required. Using a set of 34 mesocosms (∼1 m(2) each), we investigated the effects of planting diversity on carbon storage potential of four native wetland plant species that are commonly planted in created mitigation wetlands in Virginia - Carex vulpinoidea, Eleocharis obtusa, Juncus effusus, and Mimulus ringens. The plants were grown under the four distinctive PD treatments [i.e., monoculture (PD 1) through four different species mixture (PD 4)]. Plant biomass was harvested after two growing seasons and analyzed for tissue carbon content. Competition values (CV) were calculated to understand how the PD treatment affected the competitive ability of plants relative to their biomass production and thus carbon storage potentials. Aboveground biomass ranged from 988 g/m(2) - 1515 g/m(2), being greatest in monocultures, but only when compared to the most diverse mixture (p = 0.021). However, carbon storage potential estimates per mesocosm ranged between 344 g C/m(2) in the most diverse mesocosms (PD 4) to 610 g C/m(2) in monoculture ones with no significant difference (p = 0.089). CV of E. obtusa and C. vulpinoidea showed a declining trend when grown in the most diverse mixtures but J. effusus and M. ringens displayed no difference across the PD gradient (p = 0.910). In monocultures, both M. ringens, and J. effusus appeared to store carbon as biomass more

  2. Assessing the potential of native tree species for carbon sequestration forestry in Northeast China.

    PubMed

    Thomas, S C; Malczewski, G; Saprunoff, M

    2007-11-01

    Although the native forests of China are exceptionally diverse, only a small number of tree species have been widely utilized in forest plantations and reforestation efforts. We used dendrochronological sampling methods to assess the potential growth and carbon sequestration of native tree species in Jilin Province, Northeast China. Trees were sampled in and near the Changbaishan Biosphere Reserve, with samples encompassing old-growth, disturbed forest, and plantations. To approximate conditions for planted trees, sampling focused on trees with exposed crowns (dominant and co-dominant individuals). A log-linear relationship was found between diameter increment and tree diameter, with a linear decrease in increment with increasing local basal area; no significant differences in these patterns between plantations and natural stands were detected for two commonly planted species (Pinus koraiensis and Larix olgensis). A growth model that incorporates observed feedbacks with individual tree size and local basal area (in conjunction with allometric models for tree biomass), was used to project stand-level biomass increment. Predicted growth trajectories were then linked to the carbon process model InTEC to provide estimates of carbon sequestration potential. Results indicate substantial differences among species, and suggest that certain native hardwoods (in particular Fraxinus mandshurica and Phellodendron amurense), have high potential for use in carbon forestry applications. Increased use of native hardwoods in carbon forestry in China is likely to have additional benefits in terms of economic diversification and enhanced provision of "ecosystem services", including biodiversity protection. PMID:17188419

  3. The potential storage of carbon caused by eutrophication of the biosphere

    NASA Technical Reports Server (NTRS)

    Peterson, B. J.; Melillo, J. M.

    1985-01-01

    The hypothesis that the rate of atmospheric CO2 increase has been reduced due to increased net storage of carbon in forests, coastal oceans, and the open sea, caused by eutrophication of the biosphere with nitrogen and phosphorus, is examined. The potential for carbon storage, the balance of C, N, and P, and man's influence on the forests, rivers, coastal oceans, and the open sea is studied and discussed. It is concluded that biotic carbon sinks are small relative to the rate of CO2 release from fossil fuel; therefore, storage is limited. Man has reduced the stocks of carbon held in forests and soils and there is a redistribution of C, N, and P from the land to the oceans.

  4. Potential climate engineering effectiveness and side effects during a high carbon dioxide-emission scenario.

    PubMed

    Keller, David P; Feng, Ellias Y; Oschlies, Andreas

    2014-01-01

    The realization that mitigation efforts to reduce carbon dioxide emissions have, until now, been relatively ineffective has led to an increasing interest in climate engineering as a possible means of preventing the potentially catastrophic consequences of climate change. While many studies have addressed the potential effectiveness of individual methods there have been few attempts to compare them. Here we use an Earth system model to compare the effectiveness and side effects of afforestation, artificial ocean upwelling, ocean iron fertilization, ocean alkalinization and solar radiation management during a high carbon dioxide-emission scenario. We find that even when applied continuously and at scales as large as currently deemed possible, all methods are, individually, either relatively ineffective with limited (<8%) warming reductions, or they have potentially severe side effects and cannot be stopped without causing rapid climate change. Our simulations suggest that the potential for these types of climate engineering to make up for failed mitigation may be very limited. PMID:24569320

  5. Potential climate engineering effectiveness and side effects during a high carbon dioxide-emission scenario

    PubMed Central

    Keller, David P.; Feng, Ellias Y.; Oschlies, Andreas

    2014-01-01

    The realization that mitigation efforts to reduce carbon dioxide emissions have, until now, been relatively ineffective has led to an increasing interest in climate engineering as a possible means of preventing the potentially catastrophic consequences of climate change. While many studies have addressed the potential effectiveness of individual methods there have been few attempts to compare them. Here we use an Earth system model to compare the effectiveness and side effects of afforestation, artificial ocean upwelling, ocean iron fertilization, ocean alkalinization and solar radiation management during a high carbon dioxide-emission scenario. We find that even when applied continuously and at scales as large as currently deemed possible, all methods are, individually, either relatively ineffective with limited (<8%) warming reductions, or they have potentially severe side effects and cannot be stopped without causing rapid climate change. Our simulations suggest that the potential for these types of climate engineering to make up for failed mitigation may be very limited. PMID:24569320

  6. THE POTENTIAL OF RECLAIMED LANDS TO SEQUESTER CARBON AND MITIGATE THE GREENHOUSE EFFECT

    SciTech Connect

    Terry Brown; Song Jin

    2006-05-01

    Reclaimed mine lands have the potential to sequester carbon. The use of amendments to increase fertility and overall soil quality is encouraging. Waste amendments such as sewage sludge and clarifier sludge, as well as commercial compost were tested to determine their effects on carbon sequestration and humic acid formation in reclaimed mine lands. Sewage sludge and clarifier sludge have the potential to work as reclaimed mine lands amendments. C:N ratios need to be understood to determine probability of nutrient leaching and water contamination. Microbial activity on the humic acid fraction of sludge is directed toward the readily degradable constituents containing single chain functional groups. This finding indicate that amendments with lower molecular constituents such as aliphatic compounds are more amenable to microbial degradation, therefore serves as better nutrient sources to enhance the formation of vegetation in mine lands and leads to more efficient carbon sequestration.

  7. The potential of carbon fiber induced shock hazards in household toasters

    NASA Technical Reports Server (NTRS)

    Meyers, J. A.

    1979-01-01

    The average exposure to carbon fibers which produced a short and potential shock hazard in a household toaster was determined. Toasters are normally in the off state. They are used for brief periods during the day and have timed cycles during which power is applied. The possibility of a short occurring from the heating element to the case was investigated to find the exposure levels at which a potential shock hazard could appear. The short produced was tested to determine its importance.

  8. The potential for damage from the accidental release of conductive carbon fibers from burning composites

    NASA Technical Reports Server (NTRS)

    Bell, V. L.

    1980-01-01

    The potential damage to electrical equipment caused by the release of carbon fibers from burning commercial airliners is assessed in terms of annual expected costs and maximum losses at low probabilities of occurrence. A materials research program to provide alternate or modified composite materials for aircraft structures is reviewed.

  9. High biomass removal limits carbon sequestration potential of mature temperate pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Decades of plowing have depleted organic carbon stocks in many agricultural soils. Conversion of plowed fields to pasture has the potential to reverse this process, recapturing organic matter that was lost under more intensive cropping systems. Temperate pastures in the northeast USA are highly prod...

  10. SEQUESTERING CARBON IN SOIL: A WORKSHOP TO EXPLORE THE POTENTIAL FOR MITIGATING GLOBAL CLIMATE CHANGE

    EPA Science Inventory

    This workshop was an excellent forum for a scientific debate on the potential of soils to sequester additional carbon from the atmosphere. wo primary conclusions can be drawn from the workshop. irst, that steps should be taken to protect and preserve the size and integrity of the...

  11. Using semi-analytic solutions to approximate the area of potential impact for carbon dioxide injection

    EPA Science Inventory

    This study examines using the threshold critical pressure increase and the extent of the carbon dioxide (CO2) plume to delineate the area of potential impact (AoPI) for geologic CO2 storage projects. The combined area covering both the CO2 plume and the region where the pressure ...

  12. Evaluating Renewable Cornstarch/biochar Fillers as Potential Substitutes for Carbon Black in SBR Composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The continually growing demand for fossil fuels coupled with the potential risk of relying on foreign sources for these fuels strengthens the need to find renewable substitutes for petroleum products. Carbon black is a petroleum product that dominates the rubber composite filler market. Agricultur...

  13. Realistic costs of carbon capture

    SciTech Connect

    Al Juaied, Mohammed . Belfer Center for Science and International Affiaris); Whitmore, Adam )

    2009-07-01

    transport and storage costs appears to be US$100-150/tCO2 for first-of-a-kind plants and perhaps US$30-50/tCO2 for nth-of-a-kind plants.The estimates for FOAK and NOAK costs appear to be broadly consistent in the light of estimates of the potential for cost reductions with increased experience. Cost reductions are expected from increasing scale, learning on individual components, and technological innovation including improved plant integration. Innovation and integration can both lower costs and increase net output with a given cost base. These factors are expected to reduce abatement costs by approximately 65% by 2030. The range of estimated costs for NOAK plants is within the range of plausible future carbon prices, implying that mature technology would be competitive with conventional fossil fuel plants at prevailing carbon prices.

  14. Environmental projects. Volume 1: Polychlorinated biphenyl (PCB) abatement program

    NASA Technical Reports Server (NTRS)

    Kushner, L.

    1987-01-01

    Six large parabolic dish antennas are located at the Goldstone Deep Space Communications Complex north of Barstow, California. Some of the ancillary electrical equipment of thes Deep Space Stations, particularly transformers and power capicitors, were filled with stable, fire-retardant, dielectric fluids containing substances called polychlorobiphenyls (PCBs). Because the Environmental Protection Agency has determined that PCBs are environmental pollutants toxic to humans, all NASA centers have been asked to participate in a PCB-abatement program. Under the supervision of JPL's Office of Telecommunications and Data Acquisition, a two-year long PCB-abatement program has eliminated PCBs from the Goldstone Complex.

  15. Carbon financing of household water treatment: background, operation and recommendations to improve potential for health gains.

    PubMed

    Hodge, James M; Clasen, Thomas F

    2014-11-01

    Household water treatment (HWT) provides a means for vulnerable populations to take charge of their own drinking water quality as they patiently wait for the pipe to finally reach them. In many low-income countries, however, promoters have not succeeded in scaling up the intervention among the target population or securing its consistent and sustained use. Carbon financing can provide the funding for reaching targeted populations with effective HWT solutions and the incentives to ensure their long-term uptake. Nevertheless, programs have been criticized because they do not actually reduce carbon emissions. We summarize the background and operation of carbon financing of HWT interventions, including the controversial construct of "suppressed demand". We agree that these programs have limited potential to reduce greenhouse gas emissions and that their characterization of trading "carbon for water" is misleading. Nevertheless, we show that the Kyoto Protocol expressly encouraged the use of suppressed demand as a means of allowing low-income countries to benefit from carbon financing provided it is used to advance development priorities such as health. We conclude by recommending changes to existing criteria for eligible HWT programs that will help ensure that they meet the conditions of microbiological effectiveness and actual use that will improve their potential for health gains. PMID:25314642

  16. Evaluation of the sediment remediation potential of magnetite impregnated activated carbons and biochars

    NASA Astrophysics Data System (ADS)

    Werner, David; Han, Zhantao; Karapanagioti, Hrissi

    2014-05-01

    We evaluated the sediment remediation potential of magnetic composite materials synthesized by precipitating magnetite minerals onto activated carbons and biochars. Magnetite impregnation did not reduce the phenanthrene sorption capacity of the activated carbon or biochar component of the composite materials. The phenanthrene sorption capacity of the composite materials correlated with the surface areas of the pristine carbonaceous sorbents. XRD data and mass magnetic susceptibility data indicate that the mineral component of the composites is indeed nearly 100% magnetite. Addition of magnetic activated carbon to River Tyne sediment slurries reduced polycyclic aromatic hydrocarbon availability by more than 90%. After 3 months of mixing, 77% of the added magnetic activated carbon could be recovered with a magnetic rod. Continued monitoring showed that polycyclic aromatic hydrocarbon availability remained low following the magnetic recovery of most of the added sorbent mass. XRD analysis confirmed the presence of magnetite in the recovered sorbent material, with some other mineral phases such as calcite and quartz also being identifiable. Magnetic activated carbon has potential as a recoverable sorbent amendment for the treatment of sediment polluted with hydrophobic organic compounds. Further work will include an evaluation of the long-term magnetic sorbent effectiveness and stability in unmixed sediments under aerobic and anaerobic conditions and regeneration and re-use options for the recovered sorbent materials.

  17. Reforestation as a novel abatement and compliance measure for ground-level ozone.

    PubMed

    Kroeger, Timm; Escobedo, Francisco J; Hernandez, José L; Varela, Sebastián; Delphin, Sonia; Fisher, Jonathan R B; Waldron, Janice

    2014-10-01

    High ambient ozone (O3) concentrations are a widespread and persistent problem globally. Although studies have documented the role of forests in removing O3 and one of its precursors, nitrogen dioxide (NO2), the cost effectiveness of using peri-urban reforestation for O3 abatement purposes has not been examined. We develop a methodology that uses available air quality and meteorological data and simplified forest structure growth-mortality and dry deposition models to assess the performance of reforestation for O3 precursor abatement. We apply this methodology to identify the cost-effective design for a hypothetical 405-ha, peri-urban reforestation project in the Houston-Galveston-Brazoria O3 nonattainment area in Texas. The project would remove an estimated 310 tons of (t) O3 and 58 t NO2 total over 30 y. Given its location in a nitrogen oxide (NOx)-limited area, and using the range of Houston area O3 production efficiencies to convert forest O3 removal to its NOx equivalent, this is equivalent to 127-209 t of the regulated NOx. The cost of reforestation per ton of NOx abated compares favorably to that of additional conventional controls if no land costs are incurred, especially if carbon offsets are generated. Purchasing agricultural lands for reforestation removes this cost advantage, but this problem could be overcome through cost-share opportunities that exist due to the public and conservation benefits of reforestation. Our findings suggest that peri-urban reforestation should be considered in O3 control efforts in Houston, other US nonattainment areas, and areas with O3 pollution problems in other countries, wherever O3 formation is predominantly NOx limited. PMID:25201970

  18. Reforestation as a novel abatement and compliance measure for ground-level ozone

    PubMed Central

    Kroeger, Timm; Escobedo, Francisco J.; Hernandez, José L.; Varela, Sebastián; Delphin, Sonia; Fisher, Jonathan R. B.; Waldron, Janice

    2014-01-01

    High ambient ozone (O3) concentrations are a widespread and persistent problem globally. Although studies have documented the role of forests in removing O3 and one of its precursors, nitrogen dioxide (NO2), the cost effectiveness of using peri-urban reforestation for O3 abatement purposes has not been examined. We develop a methodology that uses available air quality and meteorological data and simplified forest structure growth-mortality and dry deposition models to assess the performance of reforestation for O3 precursor abatement. We apply this methodology to identify the cost-effective design for a hypothetical 405-ha, peri-urban reforestation project in the Houston–Galveston–Brazoria O3 nonattainment area in Texas. The project would remove an estimated 310 tons of (t) O3 and 58 t NO2 total over 30 y. Given its location in a nitrogen oxide (NOx)-limited area, and using the range of Houston area O3 production efficiencies to convert forest O3 removal to its NOx equivalent, this is equivalent to 127–209 t of the regulated NOx. The cost of reforestation per ton of NOx abated compares favorably to that of additional conventional controls if no land costs are incurred, especially if carbon offsets are generated. Purchasing agricultural lands for reforestation removes this cost advantage, but this problem could be overcome through cost-share opportunities that exist due to the public and conservation benefits of reforestation. Our findings suggest that peri-urban reforestation should be considered in O3 control efforts in Houston, other US nonattainment areas, and areas with O3 pollution problems in other countries, wherever O3 formation is predominantly NOx limited. PMID:25201970

  19. Potential responses of soil organic carbon to global environmental change

    PubMed Central

    Trumbore, Susan E.

    1997-01-01

    Recent improvements in our understanding of the dynamics of soil carbon have shown that 20–40% of the approximately 1,500 Pg of C stored as organic matter in the upper meter of soils has turnover times of centuries or less. This fast-cycling organic matter is largely comprised of undecomposed plant material and hydrolyzable components associated with mineral surfaces. Turnover times of fast-cycling carbon vary with climate and vegetation, and range from <20 years at low latitudes to >60 years at high latitudes. The amount and turnover time of C in passive soil carbon pools (organic matter strongly stabilized on mineral surfaces with turnover times of millennia and longer) depend on factors like soil maturity and mineralogy, which, in turn, reflect long-term climate conditions. Transient sources or sinks in terrestrial carbon pools result from the time lag between photosynthetic uptake of CO2 by plants and the subsequent return of C to the atmosphere through plant, heterotrophic, and microbial respiration. Differential responses of primary production and respiration to climate change or ecosystem fertilization have the potential to cause significant interrannual to decadal imbalances in terrestrial C storage and release. Rates of carbon storage and release in recently disturbed ecosystems can be much larger than rates in more mature ecosystems. Changes in disturbance frequency and regime resulting from future climate change may be more important than equilibrium responses in determining the carbon balance of terrestrial ecosystems. PMID:11607735

  20. Assessing potential diagenetic alteration of primary iodine-to-calcium ratios in carbonate rocks

    NASA Astrophysics Data System (ADS)

    Hardisty, D. S.; Lu, Z.; Swart, P. K.; Planavsky, N.; Gill, B. C.; Loyd, S. J.; Lyons, T. W.

    2015-12-01

    We have evaluated iodine-to-calcium (I/Ca) ratios from a series of carbonate samples with well-constrained histories of diagenetic alteration to assess the likelihood of overprints on primary water column-derived signals. Because only the oxidized iodine species, iodate, is incorporated during carbonate precipitation, I/Ca ratios have strong potential as proxies for both marine redox and carbon cycling. This utility lies with the combination of iodate's redox sensitivity as well as the close association between iodine and marine organic matter. However, despite the possibility of large pore water iodine enrichments relative to overlying seawater, carbonate alteration under reducing diagenetic conditions, and iodate-to-iodide reduction, no study has assessed the prospect of diagenetic alteration of primary I/Ca ratios. Here, we evaluated aragonite-to-calcite transformations and dolomitization within the Key Largo Limestone of South Florida and the Clino and Unda drill cores of the Bahamas Bank. Also, early burial diagenesis was studied through analysis of I/Ca ratios in short cores from a variety of shallow settings within the Exuma Bay, Bahamas. Further, we evaluated authigenic carbonates through analysis of iodine in concretions constrained to have formed during varying stages of evolving pore fluid chemistry. In all cases, I/Ca ratios show the potential for diagenetic iodine loss relative to water-column derived values, consistent with observations of quantitative reduction of dissolved iodate to iodide in pore waters before or synchronous with carbonate alteration. In no case, however, did we observe an increase in I/Ca during diagenetic transformation. Our results suggest both that primary I/Ca values and trends can be preserved but that maximum I/Ca ratios should be considered a minimum estimate of seawater iodate. We recommend that ancient carbonates with distinct I/Ca trends not indicative of diagenetic iodine loss reflect preservation of or very early

  1. Current and potential carbon stocks in Moso bamboo forests in China.

    PubMed

    Li, Pingheng; Zhou, Guomo; Du, Huaqiang; Lu, Dengsheng; Mo, Lufeng; Xu, Xiaojun; Shi, Yongjun; Zhou, Yufeng

    2015-06-01

    Bamboo forests provide important ecosystem services and play an important role in terrestrial carbon cycling. Of the approximately 500 bamboo species in China, Moso bamboo (Phyllostachys pubescens) is the most important one in terms of distribution, timber value, and other economic values. In this study, we estimated current and potential carbon stocks in China's Moso bamboo forests and in their products. The results showed that Moso bamboo forests in China stored about 611.15 ± 142.31 Tg C, 75% of which was in the top 60 cm soil, 22% in the biomass of Moso bamboos, and 3% in the ground layer (i.e., bamboo litter, shrub, and herb layers). Moso bamboo products store 10.19 ± 2.54 Tg C per year. The potential carbon stocks reach 1331.4 ± 325.1 Tg C, while the potential C stored in products is 29.22 ± 7.31 Tg C a(-1). Our results indicate that Moso bamboo forests and products play a critical role in C sequestration. The information gained in this study will facilitate policy decisions concerning carbon sequestration and management of Moso bamboo forests in China. PMID:25836664

  2. Effects of climate extremes on the terrestrial carbon cycle: concepts, processes and potential future impacts.

    PubMed

    Frank, Dorothea; Reichstein, Markus; Bahn, Michael; Thonicke, Kirsten; Frank, David; Mahecha, Miguel D; Smith, Pete; van der Velde, Marijn; Vicca, Sara; Babst, Flurin; Beer, Christian; Buchmann, Nina; Canadell, Josep G; Ciais, Philippe; Cramer, Wolfgang; Ibrom, Andreas; Miglietta, Franco; Poulter, Ben; Rammig, Anja; Seneviratne, Sonia I; Walz, Ariane; Wattenbach, Martin; Zavala, Miguel A; Zscheischler, Jakob

    2015-08-01

    Extreme droughts, heat waves, frosts, precipitation, wind storms and other climate extremes may impact the structure, composition and functioning of terrestrial ecosystems, and thus carbon cycling and its feedbacks to the climate system. Yet, the interconnected avenues through which climate extremes drive ecological and physiological processes and alter the carbon balance are poorly understood. Here, we review the literature on carbon cycle relevant responses of ecosystems to extreme climatic events. Given that impacts of climate extremes are considered disturbances, we assume the respective general disturbance-induced mechanisms and processes to also operate in an extreme context. The paucity of well-defined studies currently renders a quantitative meta-analysis impossible, but permits us to develop a deductive framework for identifying the main mechanisms (and coupling thereof) through which climate extremes may act on the carbon cycle. We find that ecosystem responses can exceed the duration of the climate impacts via lagged effects on the carbon cycle. The expected regional impacts of future climate extremes will depend on changes in the probability and severity of their occurrence, on the compound effects and timing of different climate extremes, and on the vulnerability of each land-cover type modulated by management. Although processes and sensitivities differ among biomes, based on expert opinion, we expect forests to exhibit the largest net effect of extremes due to their large carbon pools and fluxes, potentially large indirect and lagged impacts, and long recovery time to regain previous stocks. At the global scale, we presume that droughts have the strongest and most widespread effects on terrestrial carbon cycling. Comparing impacts of climate extremes identified via remote sensing vs. ground-based observational case studies reveals that many regions in the (sub-)tropics are understudied. Hence, regional investigations are needed to allow a global

  3. Soil organic carbon sequestration potential and gap of the sub-tropical region

    NASA Astrophysics Data System (ADS)

    Chiti, T.; Santini, M.; Valentini, R.

    2012-04-01

    A database of soil organic carbon (SOC) stocks was created for the sub-tropical belt using existing global SOC databases (WISE3; various SOTER) and new data from an ongoing project (ERC Africa-GHG) specific for the tropical forests of the African continent. The intent of this database is to evaluate the sequestration potential of a critical area of the world where most of the primary rainforests are located, and actually show undoubtedly high SOC losses associated with deforestation. About 4100 profiles, quite well distributed over the entire sub-tropical belt, were used to calculate the actual SOC stock for the 0-30 cm and 30-100 cm depths of mineral soil. First, this actual SOC stock has been related to the current Land Use Systems; successively, it has been interpolated taking into account Homogeneous Land Units (HLUs) in terms of soil type, climate zone and land use. Then, relying on consistent projections, of both climate and land use changes, for the years 2050 and 2100 under extremes IPCC-SRES emission scenarios such as the B1 and the A2, potential SOC stocks for these time frames has been calculated. Soil carbon sequestration gap is calculated by the difference of the actual SOC stock and the future projections. When subtracting potential from the actual SOC stocks, negative values represent a gap in terms of possible SOC losses and so reduced carbon sequestration. The soil carbon gap indicates locations where there will be low soil-carbon levels associated with medium-to-high actual SOC stocks, and medium soil-carbon levels associated with high actual SOC stocks, depending on soil type, climate and land use conditions. On the long term, 2076-2100, a SOC gap is observed under all scenarios in South America, just below the Amazonia basin, where are located open and fragmented forests. However, in the Amazonia basin deforestation decrease since no sensible SOC losses were observed. An important gap is observed also in the Congo basin and West Africa, but the

  4. Biomass Carbon in the South Mexican Pacific Coast: Exploring Mangrove Potential to REDD+ Mechanisms

    NASA Astrophysics Data System (ADS)

    Bejarano, M.; Amezcua-Torrijos, I.

    2014-12-01

    Mangroves have the highest carbon stocks amongst tropical forests. In Mexico, however, little is known about their potential to mitigate climate change. In this work, we estimated biomass carbon stocks in the Southern Mexican Pacific Coast (~69,000 ha). We quantified above and belowground biomass carbon stocks at (1) the regional scale along two environmental strata (i.e. dry and wet), and (2) at the local scale along three geomorphological types of mangroves (i.e. fringe, estuarine and basin). Regional strata were defined using intensity and influence of rivers and, the mean annual precipitation and evapotranspiration ratio (i.e., wet < 1 > dry). By lowering the stressing environmental conditions (e.g., low salinity and high sediment accumulation), we expected the highest stocks in mangroves growing in wet and estuarine strata at the regional scale and local scale, respectively. Quantifications were carried out in sixty-six sites chosen through stratified randomized design in which six strata were obtained by a full combination of regional and local strata. In all strata, aboveground carbon represents 64-67% of total carbon. Total biomass carbon was higher in wet than dry stratum (W: 87.3 ± 6.9, D: 47.0 ± 5.0, p<0.001). While at local scale, total biomass carbon was high in estuarine mangroves of both wet and dry regions (W: 91.6 ± 7.8, D: 77.6 ± 14.8, p<0.001), and these were statistically similar to fringe wet mangroves (110.9 ± 24.2, p<0.001), the stratum with the highest total carbon. Following a conservative approach, the Mexican Southern Pacific Coast is storing near 20,344 Gg CO2e. If the historical annual deforestation rate of 0.54% continues, this region could emit between 0.03 and 14.4 Gg of CO2e ha/year, out of which wet estuarine mangroves would have the highest emission values. Evidence suggests that these mangroves are the most important strata in which REDD+ mechanisms could be implemented due to (1) their carbon stocks, and (2) their highest

  5. Assessing global potential and implications of Carbon Dioxide Removal: how much, for how long, and where might it take us?

    NASA Astrophysics Data System (ADS)

    Scott, V.

    2014-12-01

    Aiming to keep cumulative anthropogenic carbon release within the 2 degrees C warming budget, useful energy services and value of fossil carbon might be retained if its extraction is balanced by carbon dioxide capture and carbon storage creation. Here, we examine this proposition: assessing the global resource available for carbon storage, the reliable duration of storage, and exploring the resulting hierarchy of different storage types. The balance between fossil carbon supply, and the sufficiency (size) and capability (technology, security) of candidate carbon stores is assessed. The timescale of carbon retention by the variety of proposed stores has potentially important consequences for future climates. A distinction between 'permanent' and 'temporary' carbon storage is considered, and the results and implications for the usage of 'temporary' stores discussed.

  6. [Calculus removal efficiency and injury potential of vertically oscillating metallic and carbon ultrasonic tips].

    PubMed

    Naef, Felix H F; Sener, Beatrice; Bürgi-Tiedemann, Christine; Schmidlin, Patrick R

    2004-01-01

    This laboratory study investigated the efficiency and aggressiveness of metallic and carbonic inserts of a vertically oscillating ultrasonic device (Vector-system) at different power settings. The following parameters concerning periodontal treatment were assessed under standardized conditions: calculus and tooth substance removal, mean surface roughness and micro morphological appearance of the treated roots. Concerning the calculus removal potential, no significant differences were found between the types of insert used. The carbon fibre inserts, however, showed significantly more tooth substance loss than the metallic inserts. These findings were confirmed by micromorphological SEM analysis. In view of these results, the repeated use of these carbon fiber inserts during periodonatal sustaining therapy cannot be recommended. PMID:15587598

  7. Marginal abatement cost curve for NOx incorporating controls, renewable electricity, energy efficiency and fuel switching

    EPA Science Inventory

    A marginal abatement cost curve (MACC) traces out the relationship between the quantity of pollution abated and the marginal cost of abating each additional unit. In the context of air quality management, MACCs typically are developed by sorting end-of-pipe controls by their resp...

  8. Marginal abatement cost curves for NOx incorporating both controls and alternative measures

    EPA Science Inventory

    A marginal abatement cost curve (MACC) traces out the efficient marginal abatement cost level for any aggregate emissions target when a least cost approach is implemented. In order for it to represent the efficient MAC level, all abatement opportunities across all sectors and loc...

  9. 23 CFR 772.9 - Analysis of traffic noise impacts and abatement measures.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 23 Highways 1 2011-04-01 2011-04-01 false Analysis of traffic noise impacts and abatement measures... AND ENVIRONMENT PROCEDURES FOR ABATEMENT OF HIGHWAY TRAFFIC NOISE AND CONSTRUCTION NOISE § 772.9 Analysis of traffic noise impacts and abatement measures. (a) The highway agency shall determine...

  10. 23 CFR 772.9 - Analysis of traffic noise impacts and abatement measures.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Analysis of traffic noise impacts and abatement measures... Analysis of traffic noise impacts and abatement measures. (a) The highway agency shall determine and..., giving weight to the benefits and cost of abatement, and to the overall social, economic...

  11. A guide to potential soil carbon sequestration; land-use management for mitigation of greenhouse gas emissions

    USGS Publications Warehouse

    Markewich, H.W.; Buell, G.R.

    2001-01-01

    Terrestrial carbon sequestration has a potential role in reducing the recent increase in atmospheric carbon dioxide (CO2) that is, in part, contributing to global warming. Because the most stable long-term surface reservoir for carbon is the soil, changes in agriculture and forestry can potentially reduce atmospheric CO2 through increased soil-carbon storage. If local governments and regional planning agencies are to effect changes in land-use management that could mitigate the impacts of increased greenhouse gas (GHG) emissions, it is essential to know how carbon is cycled and distributed on the landscape. Only then can a cost/benefit analysis be applied to carbon sequestration as a potential land-use management tool for mitigation of GHG emissions. For the past several years, the U.S. Geological Survey (USGS) has been researching the role of terrestrial carbon in the global carbon cycle. Data from these investigations now allow the USGS to begin to (1) 'map' carbon at national, regional, and local scales; (2) calculate present carbon storage at land surface; and (3) identify those areas having the greatest potential to sequester carbon.

  12. The Potential Field of Carbon Bodies as a Basis for Sorption Properties of Barrier Gas Systems

    NASA Astrophysics Data System (ADS)

    Bubenchikov, A. M.; Bubenchikov, M. A.; Potekaev, A. I.; Libin, É. E.; Khudobina, Yu. P.

    2015-11-01

    A modification of the Lennard-Jones potential allowed us, via integration over the volume of the bodies of different shapes, to determine the integral action (potential energy barrier) generated by the distributed force centers. The body generating the potential barrier was a carbon plate and the test particles overcoming this barrier were atoms or molecules of a number of gases (hydrogen, helium and methane). When considering the transit of particles (gas atoms or molecules) over this barrier, use was made of the energy barrier wave theory and the potential of a continuous body was used as a barrier. In so doing, the Schrödinger equation was integrated numerically for the molecular density. This integration yielded the expected wave pattern of the process of transit and reflection of the molecules, so a phase averaging procedure had to be applied. By varying the parameters of the layer containing force centers - field sources, the dimensions and density of the carbon plate possessing high selectivity towards separation of gas mixture containing helium, hydrogen and methane were determined. The data obtained provide an interpretation of the sorption properties of barrier carbon systems capable of filtering or separating gases.

  13. 47 CFR 22.971 - Obligation to abate unacceptable interference.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SERVICES PUBLIC MOBILE SERVICES Cellular Radiotelephone Service § 22.971 Obligation to abate unacceptable..., causes or contributes to causing unacceptable interference to a non-cellular part 90 of this chapter... or indirectly, cause or contribute to causing unacceptable interference to a non-cellular part 90...

  14. SO2 ABATEMENT FOR COAL-FIRED BOILERS IN JAPAN

    EPA Science Inventory

    The report is a compilation of information on the current status of SO2 abatement technologies for coal-fired boilers in Japan, where strict ambient air quality standards for SO2 and NOx mandate the use of various air pollution control technologies. It focuses on flue gas desulfu...

  15. Compressor station noise-abatement: a case study

    SciTech Connect

    Bianucci, J.A.; Bush, R.C.; Dooher, C.A.

    1980-01-01

    This paper describes the noise abatement measures incorporated by Pacific Gas and Electric Company into the design of its Brannan Island Compressor Station. This two unit reciprocating compressor station is located within 100 feet of a state park and 600 feet of a camp site. Operating noise level data is presented and compared to design expectations.

  16. EVALUATION OF POLLUTION ABATEMENT ALTERNATIVES: PICILLO PROPERTY, COVENTRY, RHODE ISLAND

    EPA Science Inventory

    This report describes the second phase of a two-phase investigation undertaken by the MITRE Corp. to determine the nature and severity of ground and surface water contamination at the Picillo property in Coventry, Rhode Island and to make recommendations for permanent abatement o...

  17. 26 CFR 301.6656-1 - Abatement of penalty.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ....6656-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) PROCEDURE AND ADMINISTRATION PROCEDURE AND ADMINISTRATION Additions to the Tax, Additional Amounts, and Assessable Penalties Additions to the Tax and Additional Amounts § 301.6656-1 Abatement of penalty. (a) Exception for first...

  18. QUANTITATIVE EVALUATION OF HEPA FILTRATION UNITS AT ASBESTOS ABATEMENT SITES

    EPA Science Inventory

    A study was conducted to determine-the filtering efficiencies of 31 high efficiency particulate air (HEPA) filtration units in use at asbestos-abatement projects. article-removal efficiencies for these units ranged from 90.53 to > 99.99 percent. ineteen (61%) of the units tested ...

  19. Noise levels near streets, effectiveness and cost abatement measures

    NASA Technical Reports Server (NTRS)

    Lang, J.

    1980-01-01

    During the years 1975-1978, research was carried concerning the current noise levels near streets, the annoyance felt by the population, possible noise abatement measures for these streets, and the economic impact of such measures. The results of the research are summarized.

  20. Contracting for Asbestos Abatement: What You Need to Know.

    ERIC Educational Resources Information Center

    Bittle, Edgar H.; McAllister, Jane B.

    1990-01-01

    School districts are required to determine if asbestos-containing materials exist at school facilities and design and implement asbestos abatement. Reviews how to select a contractor, draft the contract, and ensure its proper implementation by complying with the law and avoiding liability. (MLF)

  1. Estimation of Potential Carbon Dioxide Storage Capacities of Onshore Sedimentary Basins in Republic of Korea

    NASA Astrophysics Data System (ADS)

    Park, S.; Kim, J.; Lee, Y.

    2010-12-01

    The potential carbon dioxide storage capacities of the five main onshore sedimentary basins (Chungnam, Gyeongsang, Honam, Mungyeong, and Taebaeksan Basins) in Republic of Korea are estimated based on the methods suggested by the United States National Energy Technology Laboratory (NETL). The target geologic formations considered for geologic storage of carbon dioxide in the sedimentary basins are sandstone and coal beds. The density of carbon dioxide is set equal to 446.4 kg/m3. The adsorption capacity and density of coal (anthracite) are set equal to 2.71 × 10-2 kg/kg and 1.82 × 103 kg/m3, respectively. The average storage efficiency factors for sandstone and coal are set equal to 2.5% and 34.0%, respectively. The Chungnam Basin has the sandstone volume of 72 km3 and the coal volume of 1.24 km3. The average porosity of sandstone in the Chungnam Basin is 3.8%. As a result, the potential carbon dioxide storage capacities of sandstone and coal in the Chungnam Basin are estimated to be 31 Mton and 21 Mton, respectively. The Gyeongsang Basin has the sandstone volume of 1,960 km3. The average porosity of sandstone in the Gyeongsang Basin is 4.6%. As a result, the potential carbon dioxide storage capacity of sandstone in the Gyeongsang Basin is estimated to be 1,011 Mton. The Honam Basin has the sandstone volume of 8 km3 and the coal volume of 0.27 km3. The average porosity of sandstone in the Honam Basin is 1.9%. As a result, the potential carbon dioxide storage capacities of sandstone and coal in the Honam Basin are estimated to be 2 Mton and 5 Mton, respectively. The Mungyeong Basin has the sandstone volume of 60 km3 and the coal volume of 0.66 km3. The average porosity of sandstone in the Mungyeong Basin is 2.0%. As a result, the potential carbon dioxide storage capacities of sandstone and coal in the Mungyeong Basin are estimated to be 13 Mton and 11 Mton, respectively. The Taebaeksan Basin has the sandstone volume of 71 km3 and the coal volume of 0.73 km3. The

  2. ALTERATIONS IN RAT FLASH AND PATTERN REVERSAL EVOKED POTENTIALS AFTER ACUTE OR REPEATED ADMINISTRATION OF CARBON DISULFIDE (CS2)

    EPA Science Inventory

    Because solvents may selectively alter portions of visual evoked potentials, we examined the effects of carbon disulfide (CS2) on flash (FEPs) and pattern reversal (PREPs) evoked potentials. Long-Evans rats were administered (ip) carbon disulfide (CS2) either acutely or for 30 da...

  3. Impact of the choice of emission metric on greenhouse gas abatement and costs

    NASA Astrophysics Data System (ADS)

    van den Berg, Maarten; Hof, Andries F.; van Vliet, Jasper; van Vuuren, Detlef P.

    2015-02-01

    This paper analyses the effect of different emission metrics and metric values on timing and costs of greenhouse gas mitigation in least-cost emission pathways aimed at a forcing level of 3.5 W m-2 in 2100. Such an assessment is currently relevant in view of UNFCCC’s decision to replace the values currently used. An emission metric determines the relative weights of non-CO2 greenhouse gases in obtaining CO2-equivalent emissions. For the first commitment period of the Kyoto Protocol, the UNFCCC has used 100 year global warming potential (GWP) values as reported in IPCC’s Second Assessment Report. For the second commitment period, the UNFCCC has decided to use 100 year GWP values from IPCC’s Fourth Assessment Report. We find that such a change has only a minor impact on (the optimal timing of) global emission reductions and costs. However, using 20 year or 500 year GWPs to value non-CO2 greenhouse gases does result in a significant change in both costs and emission reductions in our model. CO2 reductions are favored over non-CO2 gases when the time horizon of the GWPs is increased. Application of GWPs with time horizons longer than 100 year can increase abatement costs substantially, by about 20% for 500 year GWPs. Surprisingly, we find that implementation of a metric based on a time-dependent global temperature potential does not necessary lead to lower abatement costs. The crucial factor here is how fast non-CO2 emissions can be reduced; if this is limited, the delay in reducing methane emissions cannot be (fully) compensated for later in the century, which increases total abatement costs.

  4. Potential vulnerability of southeast Alaskan wetland soil carbon stocks to climate warming

    NASA Astrophysics Data System (ADS)

    Fellman, J.; D'Amore, D. V.; Hood, E. W.

    2015-12-01

    Carbon cycling along the high latitude coastal margins of Alaska is poorly understood relative to boreal and arctic ecosystems. The perhumid coastal temperate rainforest (PCTR) of southeast Alaska has some of the densest carbon stocks (>300 Mg C ha-1) in the world but the fate of these stocks with continued warming will balance on the poorly constrained rates of carbon accumulation and loss. We quantified the rate of dissolved organic carbon (DOC) and carbon dioxide (CO2) production from four different wetland types (rich fen, poor fen, forested wetland and cedar wetland) using controlled laboratory incubations of surface (10 cm) and subsurface (25 cm) soils incubated at 8 ºC and 15 ºC for 37 weeks. This design allowed us to determine the potential vulnerability of wetland soil carbon stocks to climate warming and partition organic matter mineralization into DOC and CO2 fluxes and its controls (e.g., wetland type and temperature). Furthermore, we used fluorescence characterization of DOC and laboratory bioassays to assess how climate warming may impact the quality and bioavailability of DOC delivered to fluvial systems. Soil depth and temperature strongly influenced carbon loss in all four wetland types with the greatest CO2 fluxes observed in the rich fen and greatest DOC fluxes observed in the poor fen. Of the fluxes, CO2 was the most sensitive to incubation temperature but DOC showed more variation with wetland type. Fluxes of DOC and CO2 were positively correlated only during the last few months of the incubation suggesting strong biotic control of DOC production developed as soil organic matter decomposition progressed. Moreover, bioavailable DOC and protein-like fluorescence were greatest in the initial soil extractions but dramatically decreased over the length of the incubations. Our findings suggest that soil organic matter decomposition will increase as the PCTR continues to warm, but this response will also will vary with wetland type.

  5. Root system reserve status, a potential barometer of carbon limitations in trees

    NASA Astrophysics Data System (ADS)

    Landhäusser, Simon

    2014-05-01

    Carbon reserve allocation in trees is an important factor in tree growth and survival which in turn influences the distribution of species and forest communities and their associated carbon, water and energy fluxes at multiple scales. We still lack a comprehensive understanding of the underlying mechanisms of carbon reserve allocation in trees and how they might be influenced by drought, biotic attack, and stand age. This is particularly true for mature trees. Over a period of eight years seasonal non-structural carbon reserves (NSC) were followed in different organs of mature aspens (Populus tremuloides Michx.). Foliar, twig, stem and root tissues were sampled. Over the eight years some of the aspen clones were defoliated in 2000, 2001 and/or 2007; results indicate that after the defoliation events the NSC reserves in the roots required much longer to recover than the NSC reserves in the twigs and stems of the crown. While reserve recovery in twigs was almost immediate in defoliated trees, root starch reserves recovered only fully after two growing seasons to values comparable to undefoliated trees. These results suggest that an allocation priority could exist, which in large part might be determined by a tissue's proximity to the canopy (crown). It is hypothesized that this would be most noticeable in tall trees with small live crown ratios resulting in greater carbon reserve withdrawal along the bole. This top-down allocation could result in carbon reserves shortages in the roots during carbon limitation, which could feedback on to the canopy, further reducing aboveground growth and potentially also resiliency to future stresses.

  6. Effects of climate extremes on the terrestrial carbon cycle: concepts, processes and potential future impacts

    PubMed Central

    Frank, Dorothea; Reichstein, Markus; Bahn, Michael; Thonicke, Kirsten; Frank, David; Mahecha, Miguel D; Smith, Pete; van der Velde, Marijn; Vicca, Sara; Babst, Flurin; Beer, Christian; Buchmann, Nina; Canadell, Josep G; Ciais, Philippe; Cramer, Wolfgang; Ibrom, Andreas; Miglietta, Franco; Poulter, Ben; Rammig, Anja; Seneviratne, Sonia I; Walz, Ariane; Wattenbach, Martin; Zavala, Miguel A; Zscheischler, Jakob

    2015-01-01

    Extreme droughts, heat waves, frosts, precipitation, wind storms and other climate extremes may impact the structure, composition and functioning of terrestrial ecosystems, and thus carbon cycling and its feedbacks to the climate system. Yet, the interconnected avenues through which climate extremes drive ecological and physiological processes and alter the carbon balance are poorly understood. Here, we review the literature on carbon cycle relevant responses of ecosystems to extreme climatic events. Given that impacts of climate extremes are considered disturbances, we assume the respective general disturbance-induced mechanisms and processes to also operate in an extreme context. The paucity of well-defined studies currently renders a quantitative meta-analysis impossible, but permits us to develop a deductive framework for identifying the main mechanisms (and coupling thereof) through which climate extremes may act on the carbon cycle. We find that ecosystem responses can exceed the duration of the climate impacts via lagged effects on the carbon cycle. The expected regional impacts of future climate extremes will depend on changes in the probability and severity of their occurrence, on the compound effects and timing of different climate extremes, and on the vulnerability of each land-cover type modulated by management. Although processes and sensitivities differ among biomes, based on expert opinion, we expect forests to exhibit the largest net effect of extremes due to their large carbon pools and fluxes, potentially large indirect and lagged impacts, and long recovery time to regain previous stocks. At the global scale, we presume that droughts have the strongest and most widespread effects on terrestrial carbon cycling. Comparing impacts of climate extremes identified via remote sensing vs. ground-based observational case studies reveals that many regions in the (sub-)tropics are understudied. Hence, regional investigations are needed to allow a global

  7. Net carbon sequestration potential and emissions in home lawn turfgrasses of the United States.

    PubMed

    Selhorst, Adam; Lal, Rattan

    2013-01-01

    Soil analyses were conducted on home lawns across diverse ecoregions of the U.S. to determine the soil organic carbon (SOC) sink capacity of turfgrass soils. Establishment of lawns sequestered SOC over time. Due to variations in ecoregions, sequestration rates varied among sites from 0.9 Mg carbon (C) ha(-1) year(-1) to 5.4 Mg C ha(-1) year(-1). Potential SOC sink capacity also varied among sites ranging from 20.8 ± 1.0-96.3 ± 6.0 Mg C ha(-1). Average sequestration rate and sink capacity for all sites sampled were 2.8 ± 0.3 Mg C ha(-1) year(-1) and 45.8 ± 3.5 Mg C ha(-1), respectively. Additionally, the hidden carbon costs (HCC) due to lawn mowing (189.7 kg Ce (carbon equivalent) ha(-1) year(-1)) and fertilizer use (63.6 kg Ce ha(-1) year(-1)) for all sites totaled 254.3 kg Ce ha(-1) year(-1). Considering home lawn SOC sink capacity and HCC, mean home lawn sequestration was completely negated 184 years post establishment. The potential SOC sink capacity of home lawns in the U.S. was estimated at 496.3 Tg C, with HCC of between 2,504.1 Gg Ce year(-1) under low management regimes and 7551.4 Gg Ce year(-1) under high management. This leads to a carbon-positive system for between 66 and 199 years in U.S. home lawns. More efficient and reduction of C-intensive maintenance practices could increase the overall sequestration longevity of home lawns and improve their climate change mitigation potential. PMID:23124590

  8. Net Carbon Sequestration Potential and Emissions in Home Lawn Turfgrasses of the United States

    NASA Astrophysics Data System (ADS)

    Selhorst, Adam; Lal, Rattan

    2013-01-01

    Soil analyses were conducted on home lawns across diverse ecoregions of the U.S. to determine the soil organic carbon (SOC) sink capacity of turfgrass soils. Establishment of lawns sequestered SOC over time. Due to variations in ecoregions, sequestration rates varied among sites from 0.9 Mg carbon (C) ha-1 year-1 to 5.4 Mg C ha-1 year-1. Potential SOC sink capacity also varied among sites ranging from 20.8 ± 1.0-96.3 ± 6.0 Mg C ha-1. Average sequestration rate and sink capacity for all sites sampled were 2.8 ± 0.3 Mg C ha-1 year-1 and 45.8 ± 3.5 Mg C ha-1, respectively. Additionally, the hidden carbon costs (HCC) due to lawn mowing (189.7 kg Ce (carbon equivalent) ha-1 year-1) and fertilizer use (63.6 kg Ce ha-1 year-1) for all sites totaled 254.3 kg Ce ha-1 year-1. Considering home lawn SOC sink capacity and HCC, mean home lawn sequestration was completely negated 184 years post establishment. The potential SOC sink capacity of home lawns in the U.S. was estimated at 496.3 Tg C, with HCC of between 2,504.1 Gg Ce year-1 under low management regimes and 7551.4 Gg Ce year-1 under high management. This leads to a carbon-positive system for between 66 and 199 years in U.S. home lawns. More efficient and reduction of C-intensive maintenance practices could increase the overall sequestration longevity of home lawns and improve their climate change mitigation potential.

  9. Trihalomethane formation potential of aquatic and terrestrial fulvic and humic acids: Sorption on activated carbon.

    PubMed

    Abouleish, Mohamed Y Z; Wells, Martha J M

    2015-07-15

    Humic substances (HSs) are precursors for the formation of hazardous disinfection by-products (DBPs) during chlorination of water. Various surrogate parameters have been used to investigate the generation of DBPs by HS precursors and the removal of these precursors by activated carbon treatment. Dissolved organic carbon (DOC)- and ultraviolet absorbance (UVA254)-based isotherms are commonly reported and presumed to be good predictors of the trihalomethane formation potential (THMFP). However, THMFP-based isotherms are rarely published such that the three types of parameters have not been compared directly. Batch equilibrium experiments on activated carbon were used to generate constant-initial-concentration sorption isotherms for well-characterized samples obtained from the International Humic Substances Society (IHSS). HSs representing type (fulvic acid [FA], humic acid [HA]), origin (aquatic, terrestrial), and geographical source (Nordic, Suwannee, Peat, Soil) were examined at pH6 and pH9. THMFP-based isotherms were generated and compared to determine if DOC- and UVA254-based isotherms were good predictors of the THMFP. The sorption process depended on the composition of the HSs and the chemical nature of the activated carbon, both of which were influenced by pH. Activated carbon removal of THM-precursors was pH- and HS-dependent. In some instances, the THMFP existed after UVA254 was depleted. PMID:25847173

  10. Potential in vitro effects of carbon nanotubes on human aortic endothelial cells

    SciTech Connect

    Walker, Valerie G.; Li Zheng; Hulderman, Tracy; Schwegler-Berry, Diane; Kashon, Michael L.; Simeonova, Petia P.

    2009-05-01

    Respiratory exposure of mice to carbon nanotubes induces pulmonary toxicity and adverse cardiovascular effects associated with atherosclerosis. We hypothesize that the direct contact of carbon nanotubes with endothelial cells will result in dose-dependent effects related to altered cell function and cytotoxicity which may play a role in potential adverse pulmonary and cardiovascular outcomes. To test this hypothesis, we examined the effects of purified single- and multi-walled carbon nanotubes (SWCNT and MWCNT) on human aortic endothelial cells by evaluating actin filament integrity and VE-cadherin distribution by fluorescence microscopy, membrane permeability by measuring the lactate dehydrogenase (LDH) release, proliferation/viability by WST-1 assay, and overall functionality by tubule formation assay. Marked actin filament and VE-cadherin disruption, cytotoxicity, and reduced tubule formation occurred consistently at 24 h post-exposure to the highest concentrations [50-150 {mu}g/10{sup 6} cells (1.5-4.5 {mu}g/ml)] for both SWCNT and MWCNT tested in our studies. These effects were not observed with carbon black exposure and carbon nanotube exposure in lower concentrations [1-10 {mu}g/10{sup 6} cells (0.04-0.4 {mu}g/ml)] or in any tested concentrations at 3 h post-exposure. Overall, the results indicate that SWCNT and MWCNT exposure induce direct effects on endothelial cells in a dose-dependent manner.

  11. A facile magnesium-containing calcium carbonate biomaterial as potential bone graft.

    PubMed

    He, Fupo; Zhang, Jing; Tian, Xiumei; Wu, Shanghua; Chen, Xiaoming

    2015-12-01

    The calcium carbonate is the main composition of coral which has been widely used as bone graft in clinic. Herein, we readily prepared novel magnesium-containing calcium carbonate biomaterials (MCCs) under the low-temperature conditions based on the dissolution-recrystallization reaction between unstable amorphous calcium carbonate (ACC) and metastable vaterite-type calcium carbonate with water involved. The content of magnesium in MCCs was tailored by adjusting the proportion of ACC starting material that was prepared using magnesium as stabilizer. The phase composition of MCCs with various amounts of magnesium was composed of one, two or three kinds of calcium carbonates (calcite, aragonite, and/or magnesian calcite). The different MCCs differed in topography. The in vitro degradation of MCCs accelerated with increasing amount of introduced magnesium. The MCCs with a certain amount of magnesium not only acquired higher compressive strength, but also promoted in vitro cell proliferation and osteogenic differentiation. Taken together, the facile MCCs shed light on their potential as bone graft. PMID:26539810

  12. Adhesion to Carbon Nanotube Conductive Scaffolds Forces Action-Potential Appearance in Immature Rat Spinal Neurons

    PubMed Central

    Toma, Francesca Maria; Calura, Enrica; Rizzetto, Lisa; Carrieri, Claudia; Roncaglia, Paola; Martinelli, Valentina; Scaini, Denis; Masten, Lara; Turco, Antonio; Gustincich, Stefano; Prato, Maurizio; Ballerini, Laura

    2013-01-01

    In the last decade, carbon nanotube growth substrates have been used to investigate neurons and neuronal networks formation in vitro when guided by artificial nano-scaled cues. Besides, nanotube-based interfaces are being developed, such as prosthesis for monitoring brain activity. We recently described how carbon nanotube substrates alter the electrophysiological and synaptic responses of hippocampal neurons in culture. This observation highlighted the exceptional ability of this material in interfering with nerve tissue growth. Here we test the hypothesis that carbon nanotube scaffolds promote the development of immature neurons isolated from the neonatal rat spinal cord, and maintained in vitro. To address this issue we performed electrophysiological studies associated to gene expression analysis. Our results indicate that spinal neurons plated on electro-conductive carbon nanotubes show a facilitated development. Spinal neurons anticipate the expression of functional markers of maturation, such as the generation of voltage dependent currents or action potentials. These changes are accompanied by a selective modulation of gene expression, involving neuronal and non-neuronal components. Our microarray experiments suggest that carbon nanotube platforms trigger reparative activities involving microglia, in the absence of reactive gliosis. Hence, future tissue scaffolds blended with conductive nanotubes may be exploited to promote cell differentiation and reparative pathways in neural regeneration strategies. PMID:23951361

  13. Paleokarst and fracture overprints in Mid-Continent carbonates in evaluation of horizontal drilling potential

    SciTech Connect

    Fritz, R.D.; Shelton, J.W. ); Esteban, M. ); Wilson, J.L.

    1991-03-01

    The Mid-Continent region, especially in Oklahoma and Arkansas, contains thick Paleozoic carbonate sections that are dolomitic and karstic in character. These sections commonly exhibit strong structural overprints, including intense fracturing, due primarily to Pennsylvanian orogenies. Because of their rather wide association with source rocks, these carbonates are thought to represent good potential targets for horizontal drilling. The Cambro-Ordovician Arbuckle Group, the Ordovician Viola Group, the Siluro-Devonian Hunton Group, and the Mississippian Limestone all contain zones that are locally productive. These stratigraphic units are either uniformly tight or they are heterogeneous with complex porosity profiles. In karst terranes both types commonly occur together; both require fracturing to increase porosity and permeability. Both youthful and mature stages of paleokarst are observed in the Arbuckle Group; the best porosity is developed in the youthful stage. These stages can develop microporous, planar porous, or macroporous types of reservoir geometry. All of these may be heterogeneous in nature, requiring fractures to interconnect porous intervals. Horizontal drilling is yet to be proved as a reliable method for increasing production efficiency in Mid-Continent carbonates. An evaluation of diagenetic history, especially karst processes, along with local and regional structural settings, may provide a key for improved understanding of the horizontal drilling potential in these carbonates.

  14. CO2 mitigation potential of mineral carbonation with industrial alkalinity sources in the United States.

    PubMed

    Kirchofer, Abby; Becker, Austin; Brandt, Adam; Wilcox, Jennifer

    2013-07-01

    The availability of industrial alkalinity sources is investigated to determine their potential for the simultaneous capture and sequestration of CO2 from point-source emissions in the United States. Industrial alkalinity sources investigated include fly ash, cement kiln dust, and iron and steel slag. Their feasibility for mineral carbonation is determined by their relative abundance for CO2 reactivity and their proximity to point-source CO2 emissions. In addition, the available aggregate markets are investigated as possible sinks for mineral carbonation products. We show that in the U.S., industrial alkaline byproducts have the potential to mitigate approximately 7.6 Mt CO2/yr, of which 7.0 Mt CO2/yr are CO2 captured through mineral carbonation and 0.6 Mt CO2/yr are CO2 emissions avoided through reuse as synthetic aggregate (replacing sand and gravel). The emission reductions represent a small share (i.e., 0.1%) of total U.S. CO2 emissions; however, industrial byproducts may represent comparatively low-cost methods for the advancement of mineral carbonation technologies, which may be extended to more abundant yet expensive natural alkalinity sources. PMID:23738892

  15. Deriving Multiple Benefits from Carbon Market-Based Savanna Fire Management: An Australian Example

    PubMed Central

    Russell-Smith, Jeremy; Yates, Cameron P.; Edwards, Andrew C.; Whitehead, Peter J.; Murphy, Brett P.; Lawes, Michael J.

    2015-01-01

    Carbon markets afford potentially useful opportunities for supporting socially and environmentally sustainable land management programs but, to date, have been little applied in globally significant fire-prone savanna settings. While fire is intrinsic to regulating the composition, structure and dynamics of savanna systems, in north Australian savannas frequent and extensive late dry season wildfires incur significant environmental, production and social impacts. Here we assess the potential of market-based savanna burning greenhouse gas emissions abatement and allied carbon biosequestration projects to deliver compatible environmental and broader socio-economic benefits in a highly biodiverse north Australian setting. Drawing on extensive regional ecological knowledge of fire regime effects on fire-vulnerable taxa and communities, we compare three fire regime metrics (seasonal fire frequency, proportion of long-unburnt vegetation, fire patch-size distribution) over a 15-year period for three national parks with an indigenously (Aboriginal) owned and managed market-based emissions abatement enterprise. Our assessment indicates improved fire management outcomes under the emissions abatement program, and mostly little change or declining outcomes on the parks. We attribute improved outcomes and putative biodiversity benefits under the abatement program to enhanced strategic management made possible by the market-based mitigation arrangement. For these same sites we estimate quanta of carbon credits that could be delivered under realistic enhanced fire management practice, using currently available and developing accredited Australian savanna burning accounting methods. We conclude that, in appropriate situations, market-based savanna burning activities can provide transformative climate change mitigation, ecosystem health, and community benefits in northern Australia, and, despite significant challenges, potentially in other fire-prone savanna settings. PMID:26630453

  16. Deriving Multiple Benefits from Carbon Market-Based Savanna Fire Management: An Australian Example.

    PubMed

    Russell-Smith, Jeremy; Yates, Cameron P; Edwards, Andrew C; Whitehead, Peter J; Murphy, Brett P; Lawes, Michael J

    2015-01-01

    Carbon markets afford potentially useful opportunities for supporting socially and environmentally sustainable land management programs but, to date, have been little applied in globally significant fire-prone savanna settings. While fire is intrinsic to regulating the composition, structure and dynamics of savanna systems, in north Australian savannas frequent and extensive late dry season wildfires incur significant environmental, production and social impacts. Here we assess the potential of market-based savanna burning greenhouse gas emissions abatement and allied carbon biosequestration projects to deliver compatible environmental and broader socio-economic benefits in a highly biodiverse north Australian setting. Drawing on extensive regional ecological knowledge of fire regime effects on fire-vulnerable taxa and communities, we compare three fire regime metrics (seasonal fire frequency, proportion of long-unburnt vegetation, fire patch-size distribution) over a 15-year period for three national parks with an indigenously (Aboriginal) owned and managed market-based emissions abatement enterprise. Our assessment indicates improved fire management outcomes under the emissions abatement program, and mostly little change or declining outcomes on the parks. We attribute improved outcomes and putative biodiversity benefits under the abatement program to enhanced strategic management made possible by the market-based mitigation arrangement. For these same sites we estimate quanta of carbon credits that could be delivered under realistic enhanced fire management practice, using currently available and developing accredited Australian savanna burning accounting methods. We conclude that, in appropriate situations, market-based savanna burning activities can provide transformative climate change mitigation, ecosystem health, and community benefits in northern Australia, and, despite significant challenges, potentially in other fire-prone savanna settings. PMID:26630453

  17. Improving carbon dioxide yields and cell efficiencies for ethanol oxidation by potential scanning

    NASA Astrophysics Data System (ADS)

    Majidi, Pasha; Pickup, Peter G.

    2014-12-01

    An ethanol electrolysis cell with aqueous ethanol supplied to the anode and nitrogen at the cathode has been operated under potential cycling conditions in order to increase the yield of carbon dioxide and thereby increase cell efficiency relative to operation at a fixed potential. At ambient temperature, faradaic yields of CO2 as high as 26% have been achieved, while only transient CO2 production was observed at constant potential. Yields increased substantially at higher temperatures, with maximum values at Pt anodes reaching 45% at constant potential and 65% under potential cycling conditions. Use of a PtRu anode increased the cell efficiency by decreasing the anode potential, but this was offset by decreased CO2 yields. Nonetheless, cycling increased the efficiency relative to constant potential. The maximum yields at PtRu and 80 °C were 13% at constant potential and 32% under potential cycling. The increased yields under cycling conditions have been attributed to periodic oxidative stripping of adsorbed CO, which occurs at lower potentials on PtRu than on Pt. These results will be important in the optimization of operating conditions for direct ethanol fuel cells and for the electrolysis of ethanol to produce clean hydrogen.

  18. Adoption of Emissions Abating Technologies by U.S. Electricity Producing Firms Under the SO2 Emission Allowance Market

    NASA Astrophysics Data System (ADS)

    Creamer, Gregorio Bernardo

    The objective of this research is to determine the adaptation strategies that coal-based, electricity producing firms in the United States utilize to comply with the emission control regulations imposed by the SO2 Emissions Allowance Market created by the Clean Air Act Amendment of 1990, and the effect of market conditions on the decision making process. In particular, I take into consideration (1) the existence of carbon contracts for the provision of coal that may a affect coal prices at the plant level, and (2) local and geographical conditions, as well as political arrangements that may encourage firms to adopt strategies that appear socially less efficient. As the electricity producing sector is a regulated sector, firms do not necessarily behave in a way that maximizes the welfare of society when reacting to environmental regulations. In other words, profit maximization actions taken by the firm do not necessarily translate into utility maximization for society. Therefore, the environmental regulator has to direct firms into adopting strategies that are socially efficient, i.e., that maximize utility. The SO 2 permit market is an instrument that allows each firm to reduce marginal emissions abatement costs according to their own production conditions and abatement costs. Companies will be driven to opt for a cost-minimizing emissions abatement strategy or a combination of abatement strategies when adapting to new environmental regulations or markets. Firms may adopt one or more of the following strategies to reduce abatement costs while meeting the emission constraints imposed by the SO2 Emissions Allowance Market: (1) continue with business as usual on the production site while buying SO2 permits to comply with environmental regulations, (2) switch to higher quality, lower sulfur coal inputs that will generate less SO2 emissions, or (3) adopting new emissions abating technologies. A utility optimization condition is that the marginal value of each input

  19. Greenhouse Gas Abatement with Distributed Generation in California's Commercial Buildings

    SciTech Connect

    Stadler, Michael; Marnay, Chris; Cardoso, Goncalo; Megel, Olivier; Siddiqui, Afzal; Lai, Judy

    2009-08-15

    Lawrence Berkeley National Laboratory (LBL) is working with the California Energy Commission (CEC) to determine the role of distributed generation (DG) in greenhouse gas reductions. The impact of DG on large industrial sites is well known, and mostly, the potentials are already harvested. In contrast, little is known about the impact of DG on commercial buildings with peak electric loads ranging from 100 kW to 5 MW. We examine how DG with combined heat and power (CHP) may be implemented within the context of a cost minimizing microgrid that is able to adopt and operate various smart energy technologies, such as thermal and photovoltaic (PV) on-site generation, heat exchangers, solar thermal collectors, absorption chillers, and storage systems. We use a mixed-integer linear program (MILP) that has the minimization of a site's annual energy costs as objective. Using 138 representative commercial sites in California (CA) with existing tariff rates and technology data, we find the greenhouse gas reduction potential for California's commercial sector. This paper shows results from the ongoing research project and finished work from a two year U.S. Department of Energy research project. To show the impact of the different technologies on CO2 emissions, several sensitivity runs for different climate zones within CA with different technology performance expectations for 2020 were performed. The considered sites can contribute between 1 Mt/a and 1.8 Mt/a to the California Air Resources Board (CARB) goal of 6.7Mt/a CO2 abatement potential in 2020. Also, with lower PV and storage costs as well as consideration of a CO2 pricing scheme, our results indicate that PV and electric storage adoption can compete rather than supplement each other when the tariff structure and costs of electricity supply have been taken into consideration. To satisfy the site's objective of minimizing energy costs, the batteries will be charged also by CHP systems during off-peak and mid-peak hours and

  20. ASSESSMENT OF THE MUTAGENIC POTENTIAL OF CARBON DISULFIDE, CARBON TETRACHLORIDE, DICHLOROMETHANE, ETHYLENE DICHLORIDE, AND METHYL BROMIDE: A COMPARATIVE ANALYSIS IN RELATION TO ETHYLENE DIBROMIDE

    EPA Science Inventory

    The document provides an evaluation of the mutagenic potential of five alternative fumigants to ethylene dibromide(EDB). These include carbon disulfide(CS2), carbon tetrachloride(CCl4), dichloromethane(DCM), ethylene dichloride(EDC), and methyl bromide (MB). Of the five proposed ...

  1. Pyrolysis of wetland biomass waste: Potential for carbon sequestration and water remediation.

    PubMed

    Cui, Xiaoqiang; Hao, Hulin; He, Zhenli; Stoffella, Peter J; Yang, Xiaoe

    2016-05-15

    Management of biomass waste is crucial to the efficiency and sustainable operation of constructed wetlands. In this study, biochars were prepared using the biomass of 22 plant species from constructed wetlands and characterized by BET-N2 surface area analysis, FTIR, TGA, SEM, EDS, and elemental compositions analysis. Biochar yields ranged from 32.78 to 49.02%, with mesopores dominating the pore structure of most biochars. The biochars had a R50 recalcitrance index of class C and the carbon sequestration potential of 19.4-28%. The aquatic plant biomass from all the Chinese constructed wetlands if made into biochars has the potential to sequester 11.48 Mt carbon yr(-1) in soils over long time periods, which could offset 0.4% of annual CO2 emissions from fossil fuel combustion in China. In terms of adsorption capacity for selected pollutants, biochar derived from Canna indica plant had the greatest adsorption capacity for Cd(2+) (98.55 mg g(-1)) and NH4(+) (7.71 mg g(-1)). Whereas for PO4(3-), Hydrocotyle verticillata derived biochar showed the greatest adsorption capacities (2.91 mg g(-1)). The results from this present study demonstrated that wetland plants are valuable feedstocks for producing biochars with potential application for carbon sequestration and contaminant removal in water remediation. PMID:26978731

  2. Influence of the dynamical image potential on the rainbows in ion channeling through short carbon nanotubes

    SciTech Connect

    Borka, D.; Petrovic, S.; Neskovic, N.; Mowbray, D. J.; Miskovic, Z. L.

    2006-06-15

    We investigate the influence of the dynamic polarization of the carbon valence electrons on the angular distributions of protons channeled through short (11,9) single-wall carbon nanotubes at speeds of 3 and 5 a.u. (corresponding to the proton energies of 0.223 and 0.621 MeV), with the nanotube length varied from 0.1 to 0.3 {mu}m. The dynamic image force on protons is calculated by means of a two-dimensional hydrodynamic model for the nanotube's dielectric response, whereas the repulsive interaction with the nanotube's cylindrical wall is modeled by a continuum potential based on the Doyle-Turner interatomic potential. The angular distributions of channeled protons are generated by a computer simulation method using the numerical solution of the proton equations of motion in the transverse plane. Our analysis shows that the inclusion of the image interaction causes qualitative changes in the proton deflection function, giving rise to a number of rainbow maxima in the corresponding angular distribution. We propose that observations of those rainbow maxima could be used to deduce detailed information on the relevant interaction potentials, and consequently to probe the electron distribution inside carbon nanotubes.

  3. Tunable construction of multi-shelled hollow carbonate nanospheres and their potential applications

    NASA Astrophysics Data System (ADS)

    Ma, Xiaoming; Zhang, Xiaoting; Yang, Lin; Wang, Ge; Jiang, Kai; Wu, Geoffrey; Cui, Weigang; Wei, Zipeng

    2016-04-01

    The development of multi-shelled hollow carbonate nanospheres (MHCN) for biomedical applications is challenging, and has not been reported. In this study, a facile approach is firstly reported to synthesize hierarchically porous MHCN with controllable shell numbers using a novel strategy called layer-by-layer thermal decomposition of organic acid salts and templates. The choice of organic acid salts as the reactants is innovative and crucial. The shell numbers of porous MHCN can be easily controlled and tuned through adjusting the adsorption temperature of organic acid salts and/or the adsorption ability of the template. The synthetic method can not only open a window to prepare the multi-shelled carbonates but also provide a new strategy to synthesise other multi-shelled inorganic salts. Notably, the hierarchically porous multi-shelled hollow structures empower the carbonates with not only a large specific surface area but also good porosity and permeability, showing great potential for future applications. Herein, our in vitro/vivo evaluations show that CaCO3 MHCN possess a high drug loading capacity and a sustained-release drug profile. It is highly expected that this novel synthetic strategy for MHCN and novel MHCN platform have the potential for biomedical applications in the near future.The development of multi-shelled hollow carbonate nanospheres (MHCN) for biomedical applications is challenging, and has not been reported. In this study, a facile approach is firstly reported to synthesize hierarchically porous MHCN with controllable shell numbers using a novel strategy called layer-by-layer thermal decomposition of organic acid salts and templates. The choice of organic acid salts as the reactants is innovative and crucial. The shell numbers of porous MHCN can be easily controlled and tuned through adjusting the adsorption temperature of organic acid salts and/or the adsorption ability of the template. The synthetic method can not only open a window to

  4. Scenarios of U.S. Carbon Reductions: Potential Impacts of Energy-Efficient and Low-Carbon Technologies by 2010 and Beyond

    SciTech Connect

    Brown, M.A.

    1997-01-01

    This report presents the results of a study conducted by five US Department of Energy national laboratories that quantifies the potential for energy-efficient and low-carbon technologies to reduce carbon emissions in the US. The stimulus for this study derives from a growing recognition that any national effort to reduce the growth of greenhouse gas emissions must consider ways of increasing the productivity of energy use. To add greater definition to this view, they quantify the reductions in carbon emissions that can be attained through the improved performance and increased penetration of efficient and low-carbon technologies by the year 2010. They also take a longer-term perspective by characterizing the potential for future research and development to produce further carbon reductions over the next quarter century. As such, this report makes a strong case for the value of energy technology research, development, demonstration, and diffusion as a public response to global climate change. Three overarching conclusions emerge from their analysis of alternative carbon reduction scenarios. First, a vigorous national commitment to develop and deploy cost-effective energy-efficient and low-carbon technologies could reverse the trend toward increasing carbon emissions. Along with utility sector investments, such a commitment could halt the growth in US energy consumption and carbon emissions so that levels in 2010 are close to those in 1997 (for energy) and in 1990 (for carbon). It must be noted that such a vigorous national commitment would have to go far beyond current efforts. Second, if feasible ways are found to implement the carbon reductions, the cases analyzed in the study are judged to yield energy savings that are roughly equal to or greater than costs. Third, a next generation of energy-efficient and low-carbon technologies promises to enable the continuation of an aggressive pace of carbon reductions over the next quarter century.

  5. Modeling Dynamics of Culex pipiens Complex Populations and Assessing Abatement Strategies for West Nile Virus

    PubMed Central

    Pawelek, Kasia A.; Hager, Elizabeth J.; Hunt, Gregg J.

    2014-01-01

    The primary mosquito species associated with underground stormwater systems in the United States are the Culex pipiens complex species. This group represents important vectors of West Nile virus (WNV) throughout regions of the continental U.S. In this study, we designed a mathematical model and compared it with surveillance data for the Cx. pipiens complex collected in Beaufort County, South Carolina. Based on the best fit of the model to the data, we estimated parameters associated with the effectiveness of public health insecticide (adulticide) treatments (primarily pyrethrin products) as well as the birth, maturation, and death rates of immature and adult Cx. pipiens complex mosquitoes. We used these estimates for modeling the spread of WNV to obtain more reliable disease outbreak predictions and performed numerical simulations to test various mosquito abatement strategies. We demonstrated that insecticide treatments produced significant reductions in the Cx. pipiens complex populations. However, abatement efforts were effective for approximately one day and the vector mosquitoes rebounded until the next treatment. These results suggest that frequent insecticide applications are necessary to control these mosquitoes. We derived the basic reproductive number (ℜ0) to predict the conditions under which disease outbreaks are likely to occur and to evaluate mosquito abatement strategies. We concluded that enhancing the mosquito death rate results in lower values of ℜ0, and if ℜ0<1, then an epidemic will not occur. Our modeling results provide insights about control strategies of the vector populations and, consequently, a potential decrease in the risk of a WNV outbreak. PMID:25268229

  6. PHOTOCATALYTIC OXIDATION FOR NOx ABATEMENT: DEVELOPMENT OF A KINETIC EXPRESSION AND DESIGN TOOLS

    SciTech Connect

    Rajiv Srivastava; M. A. Ebadian

    2000-09-15

    The ''Nitrogen Oxides Emission Reduction Program'' and ''Ozone Non-Attainment Program'' in the 1990 Clean Air Act provide guidelines for controlling NOx (NO and NO{sub 2}) emissions in new and existing stationary sources. NOx emissions have local (air quality), regional (acid rain), and global (ozone production) consequences. This study aids in developing the photocatalyst technology that has potential for use in abatement of NOx. The objective of the proposed project is to apply the principles of chemical engineering fundamentals--reaction kinetics, transport phenomena and thermodynamics--in the process design for a system that will utilize a photocatalytic reactor to oxidize NOx to nitric acid (HNO{sub 3}). HNO{sub 3} can be more easily trapped than NOx on adsorbent surfaces or in water. The project dealt with the engineering aspect of the gas-solid heterogeneous oxidation of NOx. The experiments were conducted in a photocatalyst wash-coated glass flow tube reactor. A mathematical model was developed based on a rigorous description of the physical and chemical processes occurring in the reactor. The mathematical model took into account (1) intrinsic reaction kinetics (i.e., true reaction rates), (2) transport phenomena that deal with the mass transfer effects in the reactor, and (3) the geometry of the reactor. The experimental results were used for validation of the mathematical model that provides the basis for a versatile and reliable method for the purpose of design, scale-up and process control. The NOx abatement was successfully carried out in a flow tube reactor surrounded by black lights under the exploratory grant. Due to lack of funds, a comprehensive kinetic analysis for the photocatalytic reaction scheme could not be carried out. The initial experiments look very promising for use of photocatalysis for NOx abatement.

  7. Carbon sequestration potential in reclaimed mine sites in seven east-central states

    SciTech Connect

    Sperow, M.

    2006-07-15

    Terrestrial systems represent a significant potential carbon (C) sink to help mitigate or offset greenhouse gas emissions. Nearly 3.2 Mha are permitted for mining activities in the United States, which are required to be reclaimed with vegetative cover. While site-specific studies have assessed C accumulation on reclaimed mine sites, regional analyses to estimate potential C increases have not been conducted. For this analysis, potential C sequestration is analyzed on 567000 ha of mine land in a seven-state region reclaimed to cropland, pasture, or forest. Carbon accumulation is estimated for cropland, pasture, and forest soils, forest litter layer, and aboveground biomass by estimating average annual rates of C accumulation from site-specific and general C sequestration studies. The average annual rate of C storage is highest when mine land is reclaimed to forest, where the potential sequestration is 0.7 to 2.2 Tg yr{sup -1}. The C from soils, litter layer, and biomass from mine lands reclaimed to forest represents 0.3 to 1.0% of the 1990 CO{sub 2} emissions from the study region (919 Tg CO{sub 2}). To achieve the greenhouse gas (GHG) emission reduction goal of 7% below the 1990 level as proposed by the Kyoto Treaty requires CO{sub 2} emissions in the study area to be reduced by just over 64 Tg CO{sub 2}. The potential carbon storage in mine sites reclaimed to forest could account for 4 to 12.5% of these required reductions.

  8. Carbon nanotube multi-electrode array chips for noninvasive real-time measurement of dopamine, action potentials, and postsynaptic potentials.

    PubMed

    Suzuki, Ikuro; Fukuda, Mao; Shirakawa, Keiichi; Jiko, Hideyasu; Gotoh, Masao

    2013-11-15

    Multi-electrode arrays (MEAs) can be used for noninvasive, real-time, and long-term recording of electrophysiological activity and changes in the extracellular chemical microenvironment. Neural network organization, neuronal excitability, synaptic and phenotypic plasticity, and drug responses may be monitored by MEAs, but it is still difficult to measure presynaptic activity, such as neurotransmitter release, from the presynaptic bouton. In this study, we describe the development of planar carbon nanotube (CNT)-MEA chips that can measure both the release of the neurotransmitter dopamine as well as electrophysiological responses such as field postsynaptic potentials (fPSPs) and action potentials (APs). These CNT-MEA chips were fabricated by electroplating the indium-tin oxide (ITO) microelectrode surfaces. The CNT-plated ITO electrode exhibited electrochemical response, having much higher current density compared with the bare ITO electrode. Chronoamperometric measurements using these CNT-MEA chips detected dopamine at nanomolar concentrations. By placing mouse striatal brain slices on the CNT-MEA chip, we successfully measured synaptic dopamine release from spontaneous firings with a high S/N ratio of 62. Furthermore, APs and fPSPs were measured from cultured hippocampal neurons and slices with high temporal resolution and a 100-fold greater S/N ratio. Our CNT-MEA chips made it possible to measure neurotransmitter dopamine (presynaptic activities), postsynaptic potentials, and action potentials, which have a central role in information processing in the neuronal network. CNT-MEA chips could prove useful for in vitro studies of stem cell differentiation, drug screening and toxicity, synaptic plasticity, and pathogenic processes involved in epilepsy, stroke, and neurodegenerative diseases. PMID:23774164

  9. Potentially bioavailable natural organic carbon and hydrolyzable amino acids in aquifer sediments

    USGS Publications Warehouse

    Thomas, Lashun K.; Widdowson, Mark A.; Novak, John T.; Chapelle, Francis H.; Benner, Ronald; Kaiser, Karl

    2012-01-01

    This study evaluated the relationship between concentrations of operationally defined potentially bioavailable organic -carbon (PBOC) and hydrolyzable amino acids (HAAs) in sediments collected from a diverse range of chloroethene--contaminated sites. Concentrations of PBOC and HAA were measured using aquifer sediment samples collected at six selected study sites. Average concentrations of total HAA and PBOC ranged from 1.96 ± 1.53 to 20.1 ± 25.6 mg/kg and 4.72 ± 0.72 to 443 ± 65.4 mg/kg, respectively. Results demonstrated a statistically significant positive relationship between concentrations of PBOC and total HAA present in the aquifer sediment (p < 0.05). Higher levels of HAA were consistently observed at sites with greater levels of PBOC and first-order decay rates. Because amino acids are known to be readily biodegradable carbon compounds, this relationship suggests that the sequential chemical extraction procedure used to measure PBOC is a useful indicator of bioavailable carbon in aquifer sediments. This, in turn, is consistent with the interpretation that PBOC measurements can be used for estimating the amount of natural organic carbon available for driving the reductive dechlorination of chloroethenes in groundwater systems.

  10. Cancer stem cells: The potential of carbon ion beam radiation and new radiosensitizers (Review).

    PubMed

    Baek, Sung-Jae; Ishii, Hideshi; Tamari, Keisuke; Hayashi, Kazuhiko; Nishida, Naohiro; Konno, Masamitsu; Kawamoto, Koichi; Koseki, Jun; Fukusumi, Takahito; Hasegawa, Shinichiro; Ogawa, Hisataka; Hamabe, Atsushi; Miyo, Masaaki; Noguchi, Kozo; Seo, Yuji; Doki, Yuichiro; Mori, Masaki; Ogawa, Kazuhiko

    2015-11-01

    Cancer stem cells (CSCs) are a small population of cells in cancer with stem-like properties such as cell proliferation, multiple differentiation and tumor initiation capacities. CSCs are therapy-resistant and cause cancer metastasis and recurrence. One key issue in cancer therapy is how to target and eliminate CSCs, in order to cure cancer completely without relapse and metastasis. To target CSCs, many cell surface markers, DNAs and microRNAs are considered as CSC markers. To date, the majority of the reported markers are not very specific to CSCs and are also present in non-CSCs. However, the combination of several markers is quite valuable for identifying and targeting CSCs, although more specific identification methods are needed. While CSCs are considered as critical therapeutic targets, useful treatment methods remain to be established. Epigenetic gene regulators, microRNAs, are associated with tumor initiation and progression. MicroRNAs have been recently considered as promising therapeutic targets, which can alter the therapeutic resistance of CSCs through epigenetic modification. Moreover, carbon ion beam radiotherapy is a promising treatment for CSCs. Evidence indicates that the carbon ion beam is more effective against CSCs than the conventional X-ray beam. Combination therapies of radiosensitizing microRNAs and carbon ion beam radiotherapy may be a promising cancer strategy. This review focuses on the identification and treatment resistance of CSCs and the potential of microRNAs as new radiosensitizers and carbon ion beam radiotherapy as a promising therapeutic strategy against CSCs. PMID:26330103

  11. Case studies of the potential effects of carbon taxation on the stone, clay, and glass industry

    SciTech Connect

    Bock, M.J.; Boyd, G.A.; Rosenbaum, D.I.; Ross, M.H.

    1992-12-01

    This case study focuses on the potential for a carbon tax ($25 and $100 per metric ton of carbon) to reduce energy use and associated carbon dioxide (CO{sub 2}) emissions in three subsectors of the stone, clay, and glass industry: hydraulic cement, glass and glass products, and other products. A conservation supply curve analysis found that (1) opportunities for reducing fossil fuel use in the subsectors are limited (15% reduction under $100 tax) and (2) the relationship between the tax and reduced CO{sub 2} emissions is nonlinear and diminishing. Because cement manufacturing produces a significant amount of CO{sub 2}, this subsector was analyzed. A plant-level analysis found more opportunities to mitigate CO{sub 2} emissions; under a $100 tax, fossil fuel use would decrease 52%. (A conservative estimate lies between 15% and 52%). It also confirmed the nonlinear relationship, suggesting significant benefits could result from small taxes (32% reduction under $25 tax). A fuel share analysis found the cement industry could reduce carbon loading 11% under a $100 tax if gas were substituted for coal. Under a $100 tax, cement demand would decrease 17% and its price would increase 32%, a substantial increase for a material commodity. Overall, CO{sub 2} emissions from cement manufacturing would decrease 24--33% under a $100 tax and 10--18% under a $25 tax. Much of the decrease would result from the reduced demand for cement.

  12. Case studies of the potential effects of carbon taxation on the stone, clay, and glass industry

    SciTech Connect

    Bock, M.J.; Boyd, G.A. . Environmental Assessment and Information Sciences Div.); Rosenbaum, D.I. . Dept. of Economics); Ross, M.H. . Dept. of Physics)

    1992-12-01

    This case study focuses on the potential for a carbon tax ($25 and $100 per metric ton of carbon) to reduce energy use and associated carbon dioxide (CO[sub 2]) emissions in three subsectors of the stone, clay, and glass industry: hydraulic cement, glass and glass products, and other products. A conservation supply curve analysis found that (1) opportunities for reducing fossil fuel use in the subsectors are limited (15% reduction under $100 tax) and (2) the relationship between the tax and reduced CO[sub 2] emissions is nonlinear and diminishing. Because cement manufacturing produces a significant amount of CO[sub 2], this subsector was analyzed. A plant-level analysis found more opportunities to mitigate CO[sub 2] emissions; under a $100 tax, fossil fuel use would decrease 52%. (A conservative estimate lies between 15% and 52%). It also confirmed the nonlinear relationship, suggesting significant benefits could result from small taxes (32% reduction under $25 tax). A fuel share analysis found the cement industry could reduce carbon loading 11% under a $100 tax if gas were substituted for coal. Under a $100 tax, cement demand would decrease 17% and its price would increase 32%, a substantial increase for a material commodity. Overall, CO[sub 2] emissions from cement manufacturing would decrease 24--33% under a $100 tax and 10--18% under a $25 tax. Much of the decrease would result from the reduced demand for cement.

  13. Potential for reduced methane and carbon dioxide emissions from livestock and pasture management in the tropics

    PubMed Central

    Thornton, Philip K.; Herrero, Mario

    2010-01-01

    We estimate the potential reductions in methane and carbon dioxide emissions from several livestock and pasture management options in the mixed and rangeland-based production systems in the tropics. The impacts of adoption of improved pastures, intensifying ruminant diets, changes in land-use practices, and changing breeds of large ruminants on the production of methane and carbon dioxide are calculated for two levels of adoption: complete adoption, to estimate the upper limit to reductions in these greenhouse gases (GHGs), and optimistic but plausible adoption rates taken from the literature, where these exist. Results are expressed both in GHG per ton of livestock product and in Gt CO2-eq. We estimate that the maximum mitigation potential of these options in the land-based livestock systems in the tropics amounts to approximately 7% of the global agricultural mitigation potential to 2030. Using historical adoption rates from the literature, the plausible mitigation potential of these options could contribute approximately 4% of global agricultural GHG mitigation. This could be worth on the order of $1.3 billion per year at a price of $20 per t CO2-eq. The household-level and sociocultural impacts of some of these options warrant further study, however, because livestock have multiple roles in tropical systems that often go far beyond their productive utility. PMID:20823225

  14. Screened environment-dependent reactive empirical bond-order potential for atomistic simulations of carbon materials

    NASA Astrophysics Data System (ADS)

    Perriot, Romain; Gu, Xiang; Lin, You; Zhakhovsky, Vasily V.; Oleynik, Ivan I.

    2013-08-01

    A screened environment-dependent reactive empirical bond-order (SED-REBO) potential has been developed for large-scale molecular dynamics (MD) simulations of carbon materials. Based on the second-generation REBO potential developed by Brenner and co-workers [J. Phys.: Condens. MatterJCOMEL0953-898410.1088/0953-8984/14/4/312 14, 783 (2002)], the SED-REBO potential overcomes the deficiencies of the REBO potential, which arise from a short range of interatomic interactions and their abrupt switching off at the cutoff distance, by increasing the range of interatomic interactions and eliminating the explicit switching function while introducing a simple yet efficient screening function. The increased cutoff distance allows the inclusion of interactions critically important for the physically correct description of bond breaking and bond remaking. An analytic form of the attractive and repulsive pairwise terms was devised to automatically become zero at distances above the cutoff, thus, eliminating the need for the switching function. The screening function effectively screens off the second- and further-nearest-neighbor interactions for calculation of energy and forces in a smooth and continuous way for both compression and expansion. The pairwise attractive and repulsive terms were refitted within a wide range of interatomic distances to properly describe large compressions and expansions of diamond and graphene as well as their behavior near equilibrium. Good performances of the SED-REBO potential to describe bond-breaking processes at extreme tensile stresses are demonstrated in large-scale MD simulations of the nanoindentation of graphene membranes. A computationally efficient version of the SED-REBO potential is introduced for large-scale MD simulations of shock-wave compression in carbon materials. The SED-REBO potential is implemented as a module in the Large-Scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) and is freely available.

  15. Tunable construction of multi-shelled hollow carbonate nanospheres and their potential applications.

    PubMed

    Ma, Xiaoming; Zhang, Xiaoting; Yang, Lin; Wang, Ge; Jiang, Kai; Wu, Geoffrey; Cui, Weigang; Wei, Zipeng

    2016-04-28

    The development of multi-shelled hollow carbonate nanospheres (MHCN) for biomedical applications is challenging, and has not been reported. In this study, a facile approach is firstly reported to synthesize hierarchically porous MHCN with controllable shell numbers using a novel strategy called layer-by-layer thermal decomposition of organic acid salts and templates. The choice of organic acid salts as the reactants is innovative and crucial. The shell numbers of porous MHCN can be easily controlled and tuned through adjusting the adsorption temperature of organic acid salts and/or the adsorption ability of the template. The synthetic method can not only open a window to prepare the multi-shelled carbonates but also provide a new strategy to synthesise other multi-shelled inorganic salts. Notably, the hierarchically porous multi-shelled hollow structures empower the carbonates with not only a large specific surface area but also good porosity and permeability, showing great potential for future applications. Herein, our in vitro/vivo evaluations show that CaCO3 MHCN possess a high drug loading capacity and a sustained-release drug profile. It is highly expected that this novel synthetic strategy for MHCN and novel MHCN platform have the potential for biomedical applications in the near future. PMID:27049523

  16. Surface-treated carbon electrodes with modified potential of zero charge for capacitive deionization.

    PubMed

    Wu, Tingting; Wang, Gang; Zhan, Fei; Dong, Qiang; Ren, Qidi; Wang, Jianren; Qiu, Jieshan

    2016-04-15

    The potential of zero charge (Epzc) of electrodes can greatly influence the salt removal capacity, charge efficiency and cyclic stability of capacitive deionization (CDI). Thus optimizing the Epzc of CDI electrodes is of great importance. A simple strategy to negatively shift the Epzc of CDI electrodes by modifying commercial activated carbon with quaternized poly (4-vinylpyridine) (AC-QPVP) is reported in this work. The Epzc of the prepared AC-QPVP composite electrode is as negative as -0.745 V vs. Ag/AgCl. Benefiting from the optimized Epzc of electrodes, the asymmetric CDI cell which consists of the AC-QPVP electrode and a nitric acid treated activated carbon (AC-HNO3) electrode exhibits excellent CDI performance. For inverted CDI, the working potential window of the asymmetric CDI cell can reach 1.4 V, and its salt removal capacity can be as high as 9.6 mg/g. For extended voltage CDI, the salt removal capacity of the asymmetric CDI cell at 1.2/-1.2 V is 20.6 mg/g, which is comparable to that of membrane CDI using pristine activated carbon as the electrodes (19.5 mg/g). The present work provides a simple method to prepare highly positively charged CDI electrodes and may pave the way for the development of high-performance CDI cells. PMID:26878480

  17. Potential-Assisted Adsorption of Bovine Serum Albumin onto Optically-Transparent Carbon Electrodes

    PubMed Central

    Benavidez, Tomás E.; Garcia, Carlos D.

    2013-01-01

    This manuscript describes the effect of the applied potential on the adsorption of bovine serum albumin (BSA) to optically transparent carbon electrodes (OTCE). To decouple the effect of the applied potential from the high affinity of the protein for the bare surface, the surface of the OTCE was initially saturated with a layer of BSA. Experiments described in the manuscript show that potential values higher than +500 mV induced a secondary adsorption process (not observed at open-circuit potentials), yielding significant changes in the thickness (and adsorbed amount) of the BSA layer obtained. Although the process showed a significant dependence on the experimental conditions selected, the application of higher potentials, selection of pH values around the isoelectric point (IEP) of the protein, high concentrations of protein, and low ionic strengths yielded faster kinetics and the accumulation of larger amounts of protein on the substrate. These experiments, obtained around the IEP of the protein, contrast with the traditional hypothesis that enhanced electrostatic interactions between the polarized substrate and the (oppositely charged) protein are solely responsible for the enhanced adsorption. These results suggest that the potential applied to the electrode is able to polarize the adsorbed layer and induce dipole-dipole interactions between the adsorbed and the incoming protein. This mechanism could be responsible for the potential-dependent oversaturation of the surface and could bolster to the development of surfaces with enhanced catalytic activity and implants with improved biocompatibility. PMID:24156567

  18. Dissolved Organic Carbon and Natural Terrestrial Sequestration Potential in Volcanic Terrain, San Juan Mountains, Colorado

    NASA Astrophysics Data System (ADS)

    Yager, D. B.; Burchell, A.; Johnson, R. H.; Kugel, M.; Aiken, G.; Dick, R.

    2009-12-01

    The need to reduce atmospheric CO2 levels has stimulated studies to understand and quantify carbon sinks and sources. Soils represent a potentially significant natural terrestrial carbon sequestration (NTS) reservoir. This project is part of a collaborative effort to characterize carbon (C) stability in temperate soils. To examine the potential for dissolved organic carbon (DOC) values as a qualitative indicator of C-stability, peak-flow (1500 ft3/s) and low-flow (200 ft3/s) samples from surface and ground waters were measured for DOC. DOC concentrations are generally low. Median peak-flow values from all sample sites (mg/L) were: streams (0.9); seeps (1.2); wells (0.45). Median low-flow values were: streams (0.7); seeps (0.75); wells (0.5). Median DOC values decrease between June and September 0.45 mg/L for seeps, and 0.2 mg/L for streams. Elevated DOC in some ground waters as compared to surface waters indicates increased contact time with soil organic matter. Elevated peak-flow DOC in areas with propylitically-altered bedrocks, composed of a secondary acid neutralizing assemblage of calcite-chlorite-epidote, reflects increased microbial and vegetation activity as compared to reduced organic matter accumulation in highly-altered terrain composed of an acid generating assemblage with abundant pyrite. Waters sampled in propylitically-altered bedrock terrain exhibit the lowest values during low-flow and suggest bedrock alteration type may influence DOC. Previous studies revealed undisturbed soils sampled have 2 to 6 times greater total organic soil carbon (TOSC) than global averages. Forest soils underlain by intermediate to mafic volcanic bedrock have the highest C (34.15 wt%), C: N (43) and arylsulfatase enzyme activity (ave. 278, high 461 µg p-nitrophenol/g/h). Unreclaimed mine sites have the lowest C (0 to 0.78 wt%), and arylsulfatase enzyme activity (0 to 41). Radiocarbon dates on charcoal collected from paleo-burn horizons illustrate Rocky Mountain soils may

  19. Environmental projects. Volume 12: Friable asbestos abatement, GDSCC

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The Goldstone Deep Space Communications Complex (GDSCC) is part of the NASA Deep Space Network, one of the world's largest and most sensitive scientific telecommunications and radio navigation networks. Activities at the GDSCC are carried out in support of six large parabolic dish antennas. These activities may give rise to a variety of environmental hazards, particularly the danger of exposure of GDSCC personnel to asbestos fibers that have been shown to be responsible for such serious ailments as asbestosis, lung cancer, and mesothelioma. Asbestos-containing materials (ACM's) were used in the construction of many of the approximately 100 buildings and structures that were built at the GDSCC during a 30-year period from the 1950s through 1980s. The friable asbestos-abatement program at the GDSCC is presented which consists of text, illustrations, and tables that describe the friable asbestos abatement carried out at the GDSCC from December 21, 1988 through May 11, 1989.

  20. The difficulties of abating smoke in late Victorian York

    NASA Astrophysics Data System (ADS)

    Bowler, Catherine; Brimblecombe, Peter

    Historical railway documents and council minutes for the city of York reveal an active interest in abating smoke. As early as the mid-nineteenth century the public became less willing to accept pollution as a necessary part of economic progress. The Sanitary Committee of the council, while diligent in the latter part of the century, seemed unable to use the Public Health Act (1875) effectively. It undertook studies of smoke control devices and their use, but could not identify a workable method of smoke control. Industry, under continual pressure from the Town Clerk's office usually took steps to control smoke emissions. However the improvements in air quality, even when control procedures were adopted by many of the city's major factories, seem disappointing. Weak laws and limited technology hampered a very clear enthusiasm to abate smoke.

  1. Latency attention deficit: Asbestos abatement workers need us to investigate.

    PubMed

    Roelofs, Cora

    2015-12-01

    Little is known of the impact of asbestos on the health of the workers in the United States who have removed or abated asbestos from buildings following recognition of its adverse effects on health. The United States does not have a national occupational health surveillance network to monitor asbestos-related disease and, while the United States Occupational Health and Safety Administration has a strong and detailed asbestos standard, its enforcement resources are limited. A significant proportion of asbestos abatement workers are foreign-born, and may face numerous challenges in achieving safe workplaces, including lack of union representation, economic vulnerability, and inadequate training. Public health surveillance and increased and coordinated enforcement is needed to monitor the health and exposure experiences of asbestos-exposed workers. Alarming disease trends in asbestos removal workers in Great Britain suggest that, in the United States, increased public attention will be necessary to end the epidemic of asbestos-related disease. PMID:26523746

  2. HUD lead-based-paint abatement demonstration (FHA)

    SciTech Connect

    Not Available

    1991-08-01

    The toxic effects of lead on human beings, and particularly on young children, have been known for many years. Amendments to the Lead-Based Paint Poisoning Prevention Act (LPPPA) in 1987 and 1988 required the U.S. Department of Housing and Urban Development (HUD) to undertake a lead-based paint abatement demonstration program. The overall objective of the demonstration was to 'utilize a sufficient number of abatement methods in a sufficient number of areas and circumstances to demonstrate their relative cost-effectiveness...' One component of the demonstration was conducted in HUD-owned, vacant, single-family properties and was completed in the fall of 1990. A public housing component is expected to be completed in 1991. The report describes the objectives, research design, experience and findings of the completed component, which is generally known as the FHA demonstration, named after the Federal Housing Administration, which held title to the houses.

  3. Potential carbon sequestration of European arable soils estimated by modelling a comprehensive set of management practices.

    PubMed

    Lugato, Emanuele; Bampa, Francesca; Panagos, Panos; Montanarella, Luca; Jones, Arwyn

    2014-11-01

    Bottom-up estimates from long-term field experiments and modelling are the most commonly used approaches to estimate the carbon (C) sequestration potential of the agricultural sector. However, when data are required at European level, important margins of uncertainty still exist due to the representativeness of local data at large scale or different assumptions and information utilized for running models. In this context, a pan-European (EU + Serbia, Bosnia and Herzegovina, Montenegro, Albania, Former Yugoslav Republic of Macedonia and Norway) simulation platform with high spatial resolution and harmonized data sets was developed to provide consistent scenarios in support of possible carbon sequestration policies. Using the CENTURY agroecosystem model, six alternative management practices (AMP) scenarios were assessed as alternatives to the business as usual situation (BAU). These consisted of the conversion of arable land to grassland (and vice versa), straw incorporation, reduced tillage, straw incorporation combined with reduced tillage, ley cropping system and cover crops. The conversion into grassland showed the highest soil organic carbon (SOC) sequestration rates, ranging between 0.4 and 0.8 t C ha(-1)  yr(-1) , while the opposite extreme scenario (100% of grassland conversion into arable) gave cumulated losses of up to 2 Gt of C by 2100. Among the other practices, ley cropping systems and cover crops gave better performances than straw incorporation and reduced tillage. The allocation of 12 to 28% of the European arable land to different AMP combinations resulted in a potential SOC sequestration of 101-336 Mt CO2 eq. by 2020 and 549-2141 Mt CO2 eq. by 2100. Modelled carbon sequestration rates compared with values from an ad hoc meta-analysis confirmed the robustness of these estimates. PMID:24789378

  4. Electrically Driven Technologies for Radioactive Aerosol Abatement

    SciTech Connect

    David W. DePaoli; Ofodike A. Ezekoye; Costas Tsouris; Valmor F. de Almeida

    2003-01-28

    The purpose of this research project was to develop an improved understanding of how electriexecy driven processes, including electrocoalescence, acoustic agglomeration, and electric filtration, may be employed to efficiently treat problems caused by the formation of aerosols during DOE waste treatment operations. The production of aerosols during treatment and retrieval operations in radioactive waste tanks and during thermal treatment operations such as calcination presents a significant problem of cost, worker exposure, potential for release, and increased waste volume.

  5. Microwave plasma torch abatement of NF3 and SF6

    NASA Astrophysics Data System (ADS)

    Hong, Yong Cheol; Uhm, Han Sup; Chun, Byung Jun; Lee, Sun Ku; Hwang, Sang Kyu; Kim, Dong Su

    2006-03-01

    An atmospheric pressure microwave plasma torch as a tool for fluorinated compounds (FCs) abatement was presented. Detailed experiments were conducted on the abatement of NF3 and SF6 in terms of destruction and removal efficiency (DRE) using Fourier transform infrared (FTIR). Swirl gas, compressed air for stable plasma, was tangentially injected into the microwave plasma torch and a mixture of N2, NF3, or SF6, and C2H4 was axially injected. The DRE of 99.1% for NF3 was achieved without an additive gas at the total flow rate of 50.1 liters per minute (lpm) by applying a microwave power of 1.4kW. Also, a DRE of SF6 up to 90.1% was obtained at the total flow rate of 40.6lpm using an applied microwave power of 1.4kW. Experimental results indicate that the microwave plasma abatement device can successfully eliminate FCs in the semiconductor industry.

  6. Optimal control based seizure abatement using patient derived connectivity

    PubMed Central

    Taylor, Peter N.; Thomas, Jijju; Sinha, Nishant; Dauwels, Justin; Kaiser, Marcus; Thesen, Thomas; Ruths, Justin

    2015-01-01

    Epilepsy is a neurological disorder in which patients have recurrent seizures. Seizures occur in conjunction with abnormal electrical brain activity which can be recorded by the electroencephalogram (EEG). Often, this abnormal brain activity consists of high amplitude regular spike-wave oscillations as opposed to low amplitude irregular oscillations in the non-seizure state. Active brain stimulation has been proposed as a method to terminate seizures prematurely, however, a general and widely-applicable approach to optimal stimulation protocols is still lacking. In this study we use a computational model of epileptic spike-wave dynamics to evaluate the effectiveness of a pseudospectral method to simulated seizure abatement. We incorporate brain connectivity derived from magnetic resonance imaging of a subject with idiopathic generalized epilepsy. We find that the pseudospectral method can successfully generate time-varying stimuli that abate simulated seizures, even when including heterogeneous patient specific brain connectivity. The strength of the stimulus required varies in different brain areas. Our results suggest that seizure abatement, modeled as an optimal control problem and solved with the pseudospectral method, offers an attractive approach to treatment for in vivo stimulation techniques. Further, if optimal brain stimulation protocols are to be experimentally successful, then the heterogeneity of cortical connectivity should be accounted for in the development of those protocols and thus more spatially localized solutions may be preferable. PMID:26089775

  7. Ecosystem carbon stocks and sequestration potential of federal lands across the conterminous United States

    USGS Publications Warehouse

    Tan, Zhengxi; Liu, Shuguang; Sohl, Terry L.; Wu, Yiping; Young, Claudia J.

    2015-01-01

    Federal lands across the conterminous United States (CONUS) account for 23.5% of the CONUS terrestrial area but have received no systematic studies on their ecosystem carbon (C) dynamics and contribution to the national C budgets. The methodology for US Congress-mandated national biological C sequestration potential assessment was used to evaluate ecosystem C dynamics in CONUS federal lands at present and in the future under three Intergovernmental Panel on Climate Change Special Report on Emission Scenarios (IPCC SRES) A1B, A2, and B1. The total ecosystem C stock was estimated as 11,613 Tg C in 2005 and projected to be 13,965 Tg C in 2050, an average increase of 19.4% from the baseline. The projected annual C sequestration rate (in kilograms of carbon per hectare per year) from 2006 to 2050 would be sinks of 620 and 228 for forests and grasslands, respectively, and C sources of 13 for shrublands. The federal lands’ contribution to the national ecosystem C budget could decrease from 23.3% in 2005 to 20.8% in 2050. The C sequestration potential in the future depends not only on the footprint of individual ecosystems but also on each federal agency’s land use and management. The results presented here update our current knowledge about the baseline ecosystem C stock and sequestration potential of federal lands, which would be useful for federal agencies to decide management practices to achieve the national greenhouse gas (GHG) mitigation goal.

  8. Ecosystem carbon stocks and sequestration potential of federal lands across the conterminous United States.

    PubMed

    Tan, Zhengxi; Liu, Shuguang; Sohl, Terry L; Wu, Yiping; Young, Claudia J

    2015-10-13

    Federal lands across the conterminous United States (CONUS) account for 23.5% of the CONUS terrestrial area but have received no systematic studies on their ecosystem carbon (C) dynamics and contribution to the national C budgets. The methodology for US Congress-mandated national biological C sequestration potential assessment was used to evaluate ecosystem C dynamics in CONUS federal lands at present and in the future under three Intergovernmental Panel on Climate Change Special Report on Emission Scenarios (IPCC SRES) A1B, A2, and B1. The total ecosystem C stock was estimated as 11,613 Tg C in 2005 and projected to be 13,965 Tg C in 2050, an average increase of 19.4% from the baseline. The projected annual C sequestration rate (in kilograms of carbon per hectare per year) from 2006 to 2050 would be sinks of 620 and 228 for forests and grasslands, respectively, and C sources of 13 for shrublands. The federal lands' contribution to the national ecosystem C budget could decrease from 23.3% in 2005 to 20.8% in 2050. The C sequestration potential in the future depends not only on the footprint of individual ecosystems but also on each federal agency's land use and management. The results presented here update our current knowledge about the baseline ecosystem C stock and sequestration potential of federal lands, which would be useful for federal agencies to decide management practices to achieve the national greenhouse gas (GHG) mitigation goal. PMID:26417074

  9. Ecosystem carbon stocks and sequestration potential of federal lands across the conterminous United States

    PubMed Central

    Tan, Zhengxi; Liu, Shuguang; Sohl, Terry L.; Wu, Yiping; Young, Claudia J.

    2015-01-01

    Federal lands across the conterminous United States (CONUS) account for 23.5% of the CONUS terrestrial area but have received no systematic studies on their ecosystem carbon (C) dynamics and contribution to the national C budgets. The methodology for US Congress-mandated national biological C sequestration potential assessment was used to evaluate ecosystem C dynamics in CONUS federal lands at present and in the future under three Intergovernmental Panel on Climate Change Special Report on Emission Scenarios (IPCC SRES) A1B, A2, and B1. The total ecosystem C stock was estimated as 11,613 Tg C in 2005 and projected to be 13,965 Tg C in 2050, an average increase of 19.4% from the baseline. The projected annual C sequestration rate (in kilograms of carbon per hectare per year) from 2006 to 2050 would be sinks of 620 and 228 for forests and grasslands, respectively, and C sources of 13 for shrublands. The federal lands’ contribution to the national ecosystem C budget could decrease from 23.3% in 2005 to 20.8% in 2050. The C sequestration potential in the future depends not only on the footprint of individual ecosystems but also on each federal agency’s land use and management. The results presented here update our current knowledge about the baseline ecosystem C stock and sequestration potential of federal lands, which would be useful for federal agencies to decide management practices to achieve the national greenhouse gas (GHG) mitigation goal. PMID:26417074

  10. Evaluation of brain function in acute carbon monoxide poisoning with multimodality evoked potentials

    SciTech Connect

    He, Fengsheng; Liu, Xibao; Yang, Shi; Zhang, Shoulin ); Xu, Guanghua; Fang, Guangchai; Pan, Xiaowen )

    1993-02-01

    The median nerve somatosensory evoked potentials (SEP), pattern reversal visual evoked potentials (VEP), and brain stem auditory evoked potentials (BAEP) were studied in 109 healthy adults and in 88 patients with acute carbon monoxide (CO) poisoning. The upper limits for normal values of peak and interpeak latencies of multimodalities of evoked potentials in the reference group were established by a stepwise multiple regression analysis. SEP changes selectively affecting N32 and N60 were found in 78.8% of patients. There was prolonged PI00 latency of VEP in 58.2% of the cases examined. The prevalence of BAEP abnormalities in comatose patients (36%) was significantly higher than that (8.6%) in conscious patients. BAEP abnormalities were most frequently seen in comatose patients who had diminished brain stem reflexes (77.8%). It has been found that a consistent abnormality involving N2O and subsequent peaks in SEP, a remarkable prolongation of PI00 latency in VEP, or a prolongation of Ill-V interpeak latency in BAEP as well as the reoccurrence of evoked potential abnormalities after initial recovery all indicate unfavorable outcomes in patients with acute CO poisoning. The multimodality evoked potentials have proved to be sensitive indicators in the evaluation of brain dysfunction and in the prediction of prognosis of acute CO poisoning and the development of delayed encephalopathy. 16 refs., 4 figs., 6 tabs.

  11. Hexane abatement and spore emission control in a fungal biofilter-photoreactor hybrid unit.

    PubMed

    Saucedo-Lucero, J O; Quijano, G; Arriaga, S; Muñoz, R

    2014-07-15

    The performance of a fungal perlite-based biofilter coupled to a post-treatment photoreactor was evaluated over 234 days in terms of n-hexane removal, emission and deactivation of fungal spores. The biofilter and photoreactor were operated at gas residence times of 1.20 and 0.14min, respectively, and a hexane loading rate of 115±5gm(-3)h(-1). Steady n-hexane elimination capacities of 30-40gm(-3)h(-1) were achieved, concomitantly with pollutant mineralization efficiencies of 60-90%. No significant influence of biofilter irrigation frequency or irrigation nitrogen concentration on hexane abatement was recorded. Photolysis did not support an efficient hexane post-treatment likely due to the short EBRT applied in the photoreactor, while overall hexane removal and mineralization enhancements of 25% were recorded when the irradiated photoreactor was packed with ZnO-impregnated perlite. However, a rapid catalyst deactivation was observed, which required a periodic reactivation every 48h. Biofilter irrigation every 3 days supported fungal spore emissions at concentrations ranging from 2.4×10(3) to 9.0×10(4)CFUm(-3). Finally, spore deactivation efficiencies of ≈98% were recorded for the photolytic and photocatalytic post-treatment processes. This study confirmed the potential of photo-assisted post-treatment processes to mitigate the emission of hazardous fungal spores and boost the abatement performance of biotechnologies. PMID:24887128

  12. Characterizing Synergistic Water and Energy Efficiency at the Residential Scale Using a Cost Abatement Curve Approach

    NASA Astrophysics Data System (ADS)

    Stillwell, A. S.; Chini, C. M.; Schreiber, K. L.; Barker, Z. A.

    2015-12-01

    Energy and water are two increasingly correlated resources. Electricity generation at thermoelectric power plants requires cooling such that large water withdrawal and consumption rates are associated with electricity consumption. Drinking water and wastewater treatment require significant electricity inputs to clean, disinfect, and pump water. Due to this energy-water nexus, energy efficiency measures might be a cost-effective approach to reducing water use and water efficiency measures might support energy savings as well. This research characterizes the cost-effectiveness of different efficiency approaches in households by quantifying the direct and indirect water and energy savings that could be realized through efficiency measures, such as low-flow fixtures, energy and water efficient appliances, distributed generation, and solar water heating. Potential energy and water savings from these efficiency measures was analyzed in a product-lifetime adjusted economic model comparing efficiency measures to conventional counterparts. Results were displayed as cost abatement curves indicating the most economical measures to implement for a target reduction in water and/or energy consumption. These cost abatement curves are useful in supporting market innovation and investment in residential-scale efficiency.

  13. Abatement of Xenon and Iodine Emissions from Medical Isotope Production Facilities

    SciTech Connect

    Doll, Charles G.; Sorensen, Christina M.; Bowyer, Ted W.; Friese, Judah I.; Hayes, James C.; Hoffman, Emma L.; Kephart, Rosara F.

    2014-04-01

    The capability of the International Monitoring System (IMS) to detect xenon from underground nuclear explosions is dependent on the radioactive xenon background. Adding to the background, medical isotope production (MIP) by fission releases several important xenon isotopes including xenon-133 and iodine-133 that decays to xenon-133. The amount of xenon released from these facilities may be equivalent to or exceed that released from an underground nuclear explosion. Thus the release of gaseous fission products within days of irradiation makes it difficult to distinguish MIP emissions from a nuclear explosion. In addition, recent shortages in molybdenum-99 have created interest and investment opportunities to design and build new MIP facilities in the United States and throughout the world. Due to the potential increase in the number of MIP facilities, a discussion of abatement technologies provides insight into how the problem of emission control from MIP facilities can be tackled. A review of practices is provided to delineate methods useful for abatement of medical isotopes.

  14. Microbial population and functional dynamics associated with surface potential and carbon metabolism

    PubMed Central

    Ishii, Shun'ichi; Suzuki, Shino; Norden-Krichmar, Trina M; Phan, Tony; Wanger, Greg; Nealson, Kenneth H; Sekiguchi, Yuji; Gorby, Yuri A; Bretschger, Orianna

    2014-01-01

    Microbial extracellular electron transfer (EET) to solid surfaces is an important reaction for metal reduction occurring in various anoxic environments. However, it is challenging to accurately characterize EET-active microbial communities and each member's contribution to EET reactions because of changes in composition and concentrations of electron donors and solid-phase acceptors. Here, we used bioelectrochemical systems to systematically evaluate the synergistic effects of carbon source and surface redox potential on EET-active microbial community development, metabolic networks and overall electron transfer rates. The results indicate that faster biocatalytic rates were observed under electropositive electrode surface potential conditions, and under fatty acid-fed conditions. Temporal 16S rRNA-based microbial community analyses showed that Geobacter phylotypes were highly diverse and apparently dependent on surface potentials. The well-known electrogenic microbes affiliated with the Geobacter metallireducens clade were associated with lower surface potentials and less current generation, whereas Geobacter subsurface clades 1 and 2 were associated with higher surface potentials and greater current generation. An association was also observed between specific fermentative phylotypes and Geobacter phylotypes at specific surface potentials. When sugars were present, Tolumonas and Aeromonas phylotypes were preferentially associated with lower surface potentials, whereas Lactococcus phylotypes were found to be closely associated with Geobacter subsurface clades 1 and 2 phylotypes under higher surface potential conditions. Collectively, these results suggest that surface potentials provide a strong selective pressure, at the species and strain level, for both solid surface respirators and fermentative microbes throughout the EET-active community development. PMID:24351938

  15. Carbon dioxide hydrate phase equilibrium and cage occupancy calculations using ab initio intermolecular potentials.

    PubMed

    Velaga, Srinath C; Anderson, Brian J

    2014-01-16

    Gas hydrate deposits are receiving increased attention as potential locations for CO2 sequestration, with CO2 replacing the methane that is recovered as an energy source. In this scenario, it is very important to correctly characterize the cage occupancies of CO2 to correctly assess the sequestration potential as well as the methane recoverability. In order to predict accurate cage occupancies, the guest–host interaction potential must be represented properly. Earlier, these potential parameters were obtained by fitting to experimental equilibrium data and these fitted parameters do not match with those obtained by second virial coefficient or gas viscosity data. Ab initio quantum mechanical calculations provide an independent means to directly obtain accurate intermolecular potentials. A potential energy surface (PES) between H2O and CO2 was computed at the MP2/aug-cc-pVTZ level and corrected for basis set superposition error (BSSE), an error caused due to the lower basis set, by using the half counterpoise method. Intermolecular potentials were obtained by fitting Exponential-6 and Lennard-Jones 6-12 models to the ab initio PES, correcting for many-body interactions. We denoted this model as the “VAS” model. Reference parameters for structure I carbon dioxide hydrate were calculated using the VAS model (site–site ab initio intermolecular potentials) as Δμ(w)(0) = 1206 ± 2 J/mol and ΔH(w)(0) = 1260 ± 12 J/mol. With these reference parameters and the VAS model, pure CO2 hydrate equilibrium pressure was predicted with an average absolute deviation of less than 3.2% from the experimental data. Predictions of the small cage occupancy ranged from 32 to 51%, and the large cage is more than 98% occupied. The intermolecular potentials were also tested by calculating the pure CO2 density and diffusion of CO2 in water using molecular dynamics simulations. PMID:24328234

  16. Hematite Core Nanoparticles with Carbon Shell: Potential for Environmentally Friendly Production from Iron Mining Sludge

    NASA Astrophysics Data System (ADS)

    Stević, Dragana; Mihajlović, Dijana; Kukobat, Radovan; Hattori, Yoshiyuki; Sagisaka, Kento; Kaneko, Katsumi; Atlagić, Suzana Gotovac

    2016-02-01

    Hematite nanoparticles with amorphous, yet relatively uniform carbon shell, were produced based exclusively on the waste sludge from the iron mine as the raw material. The procedure for acid digestion-based purification of the sludge with the full recovery of acid vapors and the remaining non-toxic rubble is described. Synthesis of the hematite nanoparticles was performed by the arrested precipitation method with cationic surfactant. The particles were thoroughly characterized and the potential of their economical production for the battery industry is indicated.

  17. Application of Homogeneous Potentials for the Modeling of the Bauschinger Effects in Ultra Low Carbon Steel

    NASA Astrophysics Data System (ADS)

    Ha, Jin-Jin; Lee, Jin-Woo; Kuwabara, Toshihiko; Lee, Myoung-Gyu; Barlat, Frédéric

    2011-05-01

    In this work, an approach is proposed for the description of the plastic behavior of materials subjected to multiple or continuous strain path changes. In particular, although it is not formulated with a kinematic hardening rule, it provides a reasonable description of the Bauschinger effect when loading is reversed. This description of anisotropic hardening is based on homogeneous yield functions/plastic potentials combining a stable, isotropic hardening-type, component and a fluctuating component. The capability of this constitutive description is illustrated with applications on an ultra low carbon steel sheet sample deformed in three-stage uniaxial loading with two load reversals [1].

  18. The Natural Terrestrial Carbon Sequestration Potential of Rocky Mountain Soils Derived From Volcanic Bedrock

    NASA Astrophysics Data System (ADS)

    Yager, D. B.; Burchell, A.; Johnson, R. H.

    2008-12-01

    The possible economic and environmental ramifications of climate change have stimulated a range of atmospheric carbon mitigation actions, as well as, studies to understand and quantify potential carbon sinks. However, current carbon management strategies for reducing atmospheric emissions underestimate a critical component. Soils represent between 18 - 30% of the terrestrial carbon sink needed to prevent atmospheric doubling of CO2 by 2050 and a crucial element in mitigating climate change, natural terrestrial sequestration (NTS), is required. NTS includes all naturally occurring, cumulative, biologic and geologic processes that either remove CO2 from the atmosphere or prevent net CO2 emissions through photosynthesis and microbial fixation, soil formation, weathering and adsorption or chemical reactions involving principally alumino- ferromagnesium minerals, volcanic glass and clays. Additionally, NTS supports ecosystem services by improving soil productivity, moisture retention, water purification and reducing erosion. Thus, 'global climate triage' must include the protection of high NTS areas, purposeful enhancement of NTS processes and reclamation of disturbed and mined lands. To better understand NTS, we analyzed soil-cores from Colorado, Rocky Mountain Cordillera sites. North-facing, high-plains to alpine sites in non-wetland environments were selected to represent temperate soils that may be less susceptible to carbon pool declines due to global warming than soils in warmer regions. Undisturbed soils sampled have 2 to 6 times greater total organic soil carbon (TOSC) than global TOSC averages (4 - 5 Wt. %). Forest soils derived from weathering of intermediate to mafic volcanic bedrock have the highest C (34.15 Wt. %), C:N (43) and arylsulfatase (ave. 278, high 461 μg p-nitrophenol/g/h). Intermediate TOSC was identified in soils derived from Cretaceous shale (7.2 Wt. %) and Precambrian, felsic gneiss (6.2 Wt. %). Unreclaimed mine-sites have the lowest C (0

  19. Ballistic parameters and trauma potential of carbon dioxide-actuated arrow pistols.

    PubMed

    Nguyen, Tien Thanh; Grossjohann, Rico; Ekkernkamp, Axel; Bockholdt, Britta; Frank, Matthias

    2015-05-01

    Medical literature abounds with reports of injuries and fatalities caused by arrows and crossbow bolts. Crossbows are of particular forensic and traumatological interest, because their mode of construction allows for temporary mechanical storage of energy. A newly developed type of pistol (Arcus Arrowstar), which belongs to the category of air and carbon dioxide weapons, discharges arrow-shaped bolts actuated by carbon dioxide cylinders. As, to the best of the authors' knowledge, literature contains no information on this uncommon subclass of weapons it is the aim of this work to provide the experimental data and to assess the trauma potential of these projectiles based on the ascertained physical parameters. Basic kinetic parameters of these carbon dioxide-actuated bolts (velocity v = 39 m/s, energy E = 7.2 J, energy density E' = 0.26 J/mm(2)) are similar to bolts discharged by pistol crossbows. Subsequent firing resulted in a continuous and fast decrease in kinetic energy of the arrows. Test shots into ballistic soap blocks reveal a high penetration capacity, especially when compared to conventional projectiles of equal kinetic energy values (like, e.g., airgun pellets). To conclude, these data demonstrate the high efficiency of arrow-shaped projectiles, which are also characterized by a high cross-sectional density (ratio of mass to cross-sectional area of a projectile). PMID:25246008

  20. Copper/zinc bimetal nanoparticles-dispersed carbon nanofibers: A novel potential antibiotic material.

    PubMed

    Ashfaq, Mohammad; Verma, Nishith; Khan, Suphiya

    2016-02-01

    Copper (Cu) and zinc (Zn) nanoparticles (NPs) were asymmetrically distributed in carbon nanofibers (CNFs) grown on an activated carbon fiber (ACF) substrate by chemical vapor deposition (CVD). The CVD conditions were chosen such that the Cu NPs moved along with the CNFs during tip-growth, while the Zn NPs remained adhered at the ACF. The bimetal-ACF/CNF composite material was characterized by the metal NP release profiles, in-vitro hemolytic and antibacterial activities, and bacterial cellular disruption and adhesion assay. The synergetic effects of the bimetal NPs distributed in the ACFs/CNFs resulted from the relatively slower release of the Cu NPs located at the tip of the CNFs and faster release of the Zn NPs dispersed in the ACF. The Cu/Zn-grown ACFs/CNFs inhibited the growth of the Gram negative Escherichia coli, Gram positive Staphylococcus aureus, and Methicillin resistance Staphylococcus aureus bacterial strains, with superior efficiency (instant and prolonged inhibition) than the Cu or Zn single metal-grown ACFs/CNFs. The prepared bimetal-carbon composite material in this study has potential to be used in different biomedical applications such as wound healing and antibiotic wound dressing. PMID:26652451

  1. The Potential of Microbial Activity to Increase the Efficacy of Geologic Carbon Capture and Storage

    NASA Astrophysics Data System (ADS)

    Cunningham, A. B.; Gerlach, R.; Phillips, A. J.; Eldring, J.; Lauchnor, E.; Klapper, I.; Ebigbo, A.; Mitchell, A. C.; Spangler, L.

    2012-12-01

    Geologic carbon capture and storage involves the injection of CO2 into underground formations such as brine aquifers where microbe-rock-fluid interactions will occur. These interactions may be important for the long-term fate of the injected CO2 particularly near well bores and potential leakage pathways. Herein, concepts and results are presented from bench to meso-scale experiments focusing on the utility of attached microorganisms and biofilms to enhance storage security of injected CO2. Batch and flow experiments at atmospheric and geologic CO2storage-relevant pressures have demonstrated the ability of microbial biofilms to decrease the permeability of natural and artificial porous media, survive the exposure to scCO2, and facilitate the conversion of CO2 into long-term stable carbonate phases as well as increase the solubility of CO2 in brines. Recently, the microbially catalyzed process of ureolysis has been investigated for the potential to promote calcium carbonate mineralization in subsurface reservoirs using native or introduced ureolytic microorganisms, which increase the saturation state of CaCO3 via the hydrolysis of urea. The anticipated applications for this biomineralization process in the subsurface include sealing microfractures and CO2 leakage pathways for increased security of geologic carbon storage. Recent work has focused on facilitating this biomineralization process in large scale (74 cm diameter, 38 cm high sandstone) radial flow systems under ambient and subsurface relevant pressures with the goal of developing injection strategies suited for field scale deployment. Methods for microscopic and macroscopic visualization of relevant processes, such as growth of microbial biofilms, their interactions with minerals and influence on pore spaces in porous media reactors are being developed and have been used to calibrate reactive transport models. As a result, these models are being used to predict the effect of biological processes on CO2

  2. Effect of periodic potential on exciton states in semiconductor carbon nanotubes

    DOE PAGESBeta

    Roslyak, Oleksiy; Piryatinski, Andrei

    2016-05-28

    Here we develop a theoretical background to treat exciton states in semiconductor single-walled carbon nanotubes (SWCNTs) in the presence of a periodic potential induced by a surface acoustic wave (SAW) propagating along SWCNT. The formalism accounts for the electronic band splitting into the Floquet subbands induced by the Bragg scattering on the SAW potential. Optical transitions between the Floquet states and correlated electron–hole pairs (excitons) are numerically examined. Formation of new van Hove singularities within the edges of Floquet sub-bands and associated transfer of the exciton oscillator strengths resulting in the photoluminescence quenching are predicted. The simulations demonstrate the excitonmore » energy red Stark shift and reduction in the exciton binding energy. We provide comparison of our results with reported theoretical and experimental studies.« less

  3. Effects of electron exchange-correlation potential on electrostatic oscillations in single-walled carbon nanotubes

    SciTech Connect

    Khan, S. A. Hassan, Sunia

    2014-05-28

    Using macroscopic quantum hydrodynamic formulation, we study the dispersion properties of electrostatic electron plasma oscillations in single-walled carbon nanotubes. The electrons and ions are considered uniformly distributed over the cylindrical surface of a nanotube thus forming a two-component (electron-ion) quantum plasma system. Electron degeneracy via Fermi-Dirac statistics as well as electron exchange and correlation effects is taken into account. It is found that the quantum (Bohm) potential arising due to fermionic nature of electrons and exchange-correlations effects has significant impact on the wave. The frequency of wave is influenced by variation in azimuthal index and radius of the nanotube. The results are analyzed numerically for typical systems for relatively longer wavelength waves and possible consequences are discussed. The results can be important in general understanding of the role of exchange-correlation potential in quantum hydrodynamic treatment of charge-carriers in nanotubes.

  4. Potential energy, force distribution and oscillatory motion of chloride ion inside electrically charged carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Sadeghi, F.; Ansari, R.; Darvizeh, M.

    2016-06-01

    In this research, a continuum-based model is presented to explore potential energy, force distribution and oscillatory motion of ions, and in particular chloride ion, inside carbon nanotubes (CNTs) decorated by functional groups at two ends. To perform this, van der Waals (vdW) interactions between ion and nanotube are modeled by the 6-12 Lennard-Jones (LJ) potential, whereas the electrostatic interactions between ion and functional groups are modeled by the Coulomb potential and the total interactions are analytically derived by summing the vdW and electrostatic interactions. Making the assumption that carbon atoms and charge of functional groups are all uniformly distributed over the nanotube surface and the two ends of nanotube, respectively, a continuum approach is utilized to evaluate the related interactions. Based on the actual force distribution, the equation of motion is also solved numerically to arrive at the time history of displacement and velocity of inner core. With respect to the proposed formulations, comprehensive studies on the variations of potential energy and force distribution are carried out by varying functional group charge and nanotube length. Moreover, the effects of these parameters together with initial conditions on the oscillatory behavior of system are studied and discussed in detail. It is found out that chloride ion escapes more easily from negatively charged CNTs which is followed by uncharged and positively charged ones. It is further shown that the presence of functional groups leads to enhancing the operating frequency of such oscillatory systems especially when the electric charges of ion and functional groups have different signs.

  5. Meta-modeling soil organic carbon sequestration potential and its application at regional scale.

    PubMed

    Luo, Zhongkui; Wang, Enli; Bryan, Brett A; King, Darran; Zhao, Gang; Pan, Xubin; Bende-Michl, Ulrike

    2013-03-01

    Upscaling the results from process-based soil-plant models to assess regional soil organic carbon (SOC) change and sequestration potential is a great challenge due to the lack of detailed spatial information, particularly soil properties. Meta-modeling can be used to simplify and summarize process-based models and significantly reduce the demand for input data and thus could be easily applied on regional scales. We used the pre-validated Agricultural Production Systems sIMulator (APSIM) to simulate the impact of climate, soil, and management on SOC at 613 reference sites across Australia's cereal-growing regions under a continuous wheat system. We then developed a simple meta-model to link the APSIM-modeled SOC change to primary drivers, i.e., the amount of recalcitrant SOC, plant available water capacity of soil, soil pH, and solar radiation, temperature, and rainfall in the growing season. Based on high-resolution soil texture data and 8165 climate data points across the study area, we used the meta-model to assess SOC sequestration potential and the uncertainty associated with the variability of soil characteristics. The meta-model explained 74% of the variation of final SOC content as simulated by APSIM. Applying the meta-model to Australia's cereal-growing regions reveals regional patterns in SOC, with higher SOC stock in cool, wet regions. Overall, the potential SOC stock ranged from 21.14 to 152.71 Mg/ha with a mean of 52.18 Mg/ha. Variation of soil properties induced uncertainty ranging from 12% to 117% with higher uncertainty in warm, wet regions. In general, soils in Australia's cereal-growing regions under continuous wheat production were simulated as a sink of atmospheric carbon dioxide with a mean sequestration potential of 8.17 Mg/ha. PMID:23634591

  6. Distribution of potentially bioavailable natural organic carbon in aquifer sediments at a chloroethene-contaminated site

    USGS Publications Warehouse

    Thomas, L.K.; Widdowson, M.A.; Chapelle, F.H.; Novak, J.T.; Boncal, J.E.; Lebrón, C. A.

    2012-01-01

    The distribution of natural organic carbon was investigated at a chloroethene-contaminated site where complete reductive dechlorination of tetrachloroethene (PCE) to vinyl chloride and ethene was observed. In this study, operationally defined potentially bioavailable organic carbon (PBOC) was measured in surficial aquifer sediment samples collected at varying depths and locations in the vicinity of a dense nonaqueous phase liquid (DNAPL) source and aqueous phase plume. The relationship between chloroethene concentrations and PBOC levels was examined by comparing differences in extractable organic carbon in aquifer sediments with minimal chloroethene exposure relative to samples collected in the source zone. Using performance-monitoring data, direct correlations with PBOC were also developed with chloroethene concentrations in groundwater. Results show a logarithm-normal distribution for PBOC in aquifer sediments with a mean concentration of 187  mg/kg. PBOC levels in sediments obtained from the underlying confining unit were generally greater when compared to sediments collected in the sandy surficial aquifer. Results demonstrated a statistically significant inverse correlation (p=0.007) between PBOC levels in aquifer sediments and chloroethene concentrations for selected monitoring wells in which chloroethene exposure was the highest. Results from laboratory exposure assays also demonstrated that sediment samples exhibited a reduction in PBOC levels of 35% and 73%, respectively, after a 72-h exposure period to PCE (20,000  μg/L). These results support the notion that PBOC depletion in sediments may be expected in chloroethene-contaminated aquifers, which has potential implications for the long-term sustainability of monitored natural attenuation.

  7. Lung Microtissue Array to Screen the Fibrogenic Potential of Carbon Nanotubes

    PubMed Central

    Chen, Zhaowei; Wang, Qixin; Asmani, Mohammadnabi; Li, Yan; Liu, Chang; Li, Changning; Lippmann, Julian M.; Wu, Yun; Zhao, Ruogang

    2016-01-01

    Due to their excellent physical and chemical characteristics, multi-wall carbon nanotubes (MWCNT) have the potential to be used in structural composites, conductive materials, sensors, drug delivery and medical imaging. However, because of their small-size and light-weight, the applications of MWCNT also raise health concerns. In vivo animal studies have shown that MWCNT cause biomechanical and genetic alterations in the lung tissue which lead to lung fibrosis. To screen the fibrogenic risk factor of specific types of MWCNT, we developed a human lung microtissue array device that allows real-time and in-situ readout of the biomechanical properties of the engineered lung microtissue upon MWCNT insult. We showed that the higher the MWCNT concentration, the more severe cytotoxicity was observed. More importantly, short type MWCNT at low concentration of 50 ng/ml stimulated microtissue formation and contraction force generation, and caused substantial increase in the fibrogenic marker miR-21 expression, indicating the high fibrogenic potential of this specific carbon nanotube type and concentration. The presented microtissue array system provides a powerful tool for high-throughput examination of the therapeutic and toxicological effects of target compounds in realistic tissue environment. PMID:27510174

  8. Lung Microtissue Array to Screen the Fibrogenic Potential of Carbon Nanotubes.

    PubMed

    Chen, Zhaowei; Wang, Qixin; Asmani, Mohammadnabi; Li, Yan; Liu, Chang; Li, Changning; Lippmann, Julian M; Wu, Yun; Zhao, Ruogang

    2016-01-01

    Due to their excellent physical and chemical characteristics, multi-wall carbon nanotubes (MWCNT) have the potential to be used in structural composites, conductive materials, sensors, drug delivery and medical imaging. However, because of their small-size and light-weight, the applications of MWCNT also raise health concerns. In vivo animal studies have shown that MWCNT cause biomechanical and genetic alterations in the lung tissue which lead to lung fibrosis. To screen the fibrogenic risk factor of specific types of MWCNT, we developed a human lung microtissue array device that allows real-time and in-situ readout of the biomechanical properties of the engineered lung microtissue upon MWCNT insult. We showed that the higher the MWCNT concentration, the more severe cytotoxicity was observed. More importantly, short type MWCNT at low concentration of 50 ng/ml stimulated microtissue formation and contraction force generation, and caused substantial increase in the fibrogenic marker miR-21 expression, indicating the high fibrogenic potential of this specific carbon nanotube type and concentration. The presented microtissue array system provides a powerful tool for high-throughput examination of the therapeutic and toxicological effects of target compounds in realistic tissue environment. PMID:27510174

  9. Silicon-doped carbon nanotubes: a potential resource for the detection of chlorophenols/chlorophenoxy radicals

    NASA Astrophysics Data System (ADS)

    Jiang, Haihui; Zhang, Dongju; Wang, Ruoxi

    2009-04-01

    Chlorinated phenols and chlorophenoxy radicals are known as predominant precursors for forming polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDF), which are highly carcinogenic and persistent organic pollutants (POPs). Density functional theory (DFT) calculations have been carried out to explore the potential possibility of carbon nanotubes (CNTs) serving as the resource for detecting and/or adsorbing these PCDD/PCDF precursors. Based on the calculated results on a pristine (8, 0) CNT and a Si-doped (8, 0) CNT with and without the presence of a 2-chlorophenol (2-CP)/2-chlorophenoxy radical (2-CPR), the typical representative of chlorophenols/chlorophenoxy radicals, we propose that pristine carbon nanotubes (CNTs) may be unsuitable for the desired applications due to their poor capability for catching chlorinated phenols/chlorophenoxy radicals, on the other hand, Si-doped CNTs are expected to be a potential resource for detecting and/or adsorbing (concentrating) these PCDD/PCDF precursors. The present results provide a guide to the relevant experimentalists, who are exploring novel applications of CNT-based materials in nanoscience and nanotechnology, and/or searching for suitable resources for detecting chlorophenols/chlorophenoxy radicals.

  10. Estimating urban trees and carbon stock potentials for mitigating climate change in Lagos: Case of Ikeja Government Reserved Area (GRA)

    NASA Astrophysics Data System (ADS)

    Elias, P. O.; Faderin, A.

    2014-12-01

    Urban trees are a component of the urban infrastructure which offers diverse services including environmental, aesthetic and economic. The accumulation of carbon in the atmosphere resulting from the indiscriminate distribution of human populations and urban activities with the unsustainable consumption of natural resources contributes to global environmental change especially in coastal cities like Lagos. Carbon stocks and sequestration by urban trees are increasingly recognized to play significant roles for mitigating climate change. This paper focuses on the estimation of carbon stock and sequestration through biomass estimation and quantification in Ikeja GRA, Lagos. Ikeja possesses a characteristic feature as a microcosm of Lagos due to the wide range of land uses. A canopy assessment of tree population was carried out using itree canopy software. A GPS survey was used to collect an inventory of all trees showing their location, spatial distribution and other attributes. The analysis of the carbon storage and sequestration potential of both actual and potential tree planting sites involved biomass estimations from tree allometry equations. Trees were identified at species level and measurements of their dendrometric values were recorded and integrated into the GIS database to estimate biomass of trees and carbon storage. The trees in the study area were estimated to have a biomass of 441.9 mg and carbon storage of 221.395 kg/tree. By considering the potential tree planting sites the estimated carbon stored increased to 11,352.73 kg. Carbon sequestration value in the study area was found to be 1.6790 tonnes for the existing trees and 40.707 tonnes for the potential tree planting sites (PTPS). The estimation of carbon storage and sequestration values of trees are important incentives for carbon accounting/footprints and monitoring of climate change mitigation which has implications for evaluation and monitoring of urban ecosystem.

  11. Potential climate change impacts on microbial distribution and carbon cycling in the Australian Southern Ocean

    NASA Astrophysics Data System (ADS)

    Evans, Claire; Thomson, Paul G.; Davidson, Andrew T.; Bowie, Andrew R.; van den Enden, Rick; Witte, Harry; Brussaard, Corina P. D.

    2011-11-01

    Changes in oceanic circulation and physiochemical parameters due to climate change may alter the distribution, structure and function of marine microbial communities, thereby altering the action of the biological carbon pump. One area of current and predicted future change is the sub-Antarctic zone (SAZ) to the southeast of Tasmania, Australia, where a southward shift in westerly winds appears to be forcing warmer and macronutrient-poor subtropical waters into the sub-Antarctic zone (SAZ). We investigated the impact of these subtropical waters on the microbial community of the SAZ on the SAZ-Sense cruise during the austral summer of 2007. The abundance of pico- and nanoeukaryotic algae, cyanobacteria, heterotrophic nanoflagellates, bacteria and viruses was determined by flow cytometry at stations in the Polar Frontal Zone (PFZ), the SAZ and in Subtropical Zone (STZ). Using cluster and similarity profile analyses on integrated microbial abundances over the top 200 m, we found that microbial communities located in the potential future SAZ to the southeast of Tasmania formed two distinct groups from those of the remainder of the SAZ and the PFZ. In the waters of the potential future SAZ, shallow mixed layers and increased iron concentrations elevated cyanobacterial, bacterial and viral abundances and increased percentage high DNA bacteria, resulting in communities similar to those of subtropical waters. Conversely, waters of the PFZ exhibited relatively low concentrations of autotrophic and heterotrophic microbes and viruses, indicative of the iron limitation in this region. A Distance Based Linear Model determined that salinity and nitrogen availability (nitrate, nitrite and ammonia concentrations) were the most influential environmental parameters over the survey, explaining 72% of the variation in microbial community structure. The microbial community of the potential future SAZ showed a shift away from particulate carbon export from the photic zone towards

  12. Potential for progress in carbon cycle modeling: models as tools and representations of reality (Invited)

    NASA Astrophysics Data System (ADS)

    Caldeira, K.

    2013-12-01

    attribution) Potential for progress in carbon-cycle modeling rests in being clear about the problems we seek to solve, and then developing tools to solve those problems. A global carbon cycle model that represents underlying complexity in all its detail may ultimately prove useless: 'We actually made a map of the country, on the scale of a mile to the mile!' 'Have you used it much?' I enquired. 'It has never been spread out, yet,' said Mein Herr: 'the farmers objected: they said it would cover the whole country, and shut out the sunlight! So we now use the country itself, as its own map, and I assure you it does nearly as well.' - Lewis Carroll

  13. Microbial Degradation and Carbon Biosequestration Potential of Biochar in Contrasting Soils

    NASA Astrophysics Data System (ADS)

    Tas, N.; Castanha, C.; Reichl, K.; Fischer, M. L.; Brodie, E. L.; Torn, M. S.; Jansson, J. K.

    2012-12-01

    Biochar is a carbon-rich product that is produced by high-temperature and low-oxygen pyrolysis of biomass, whose addition to soil has been proposed as a promising method for carbon sequestration. Biochar carbon has been assumed to be stable in soil, but recent research shows that it is at least partly degradable by soil microbes. However, the influence of environmental conditions on microbial transformation of biochar is poorly understood. Our overall goal is to determine the factors that regulate microbial decomposition of biochar in soils. We performed laboratory incubation experiments to compare the potential for biochar decomposition in soils from contrasting ecosystems (tropical forest from Puerto Rico and Mediterranean grassland from California), varied temperatures (ambient and +6°C) and depths (A and B horizons). Soil incubations with pyrolyzed 13C-enriched wood were continuously monitored for heterotrophic respiration using an online Cavity Ringdown Spectrometer. Samples collected after 10 and 150 days of incubation were analyzed for the activity of extracellular enzymes while changes in microbial community composition were assessed via pyrotag sequencing of both 16S rRNA and 16S rRNA genes. 13C-CO2 measurements confirmed that a fraction of added biochar was degraded in both soils during the one-year incubation period. Biochar addition was associated with a decline in cellulose and hemicellulose degrading enzyme activity in grassland soils, although not in tropical soils. In both soils, native soil organic carbon decomposition was not significantly impacted by biochar addition. Principle coordinates analysis of microbial composition showed that both soils harbored different microbial communities and those communities at different depths were distinct. The main bacterial groups enriched by biochar addition were Actinobacteria in the grassland soil, and α-Proteobacteria, Actinobacteria and Acidobacteria in the tropical soil. Analysis of 16S r

  14. Abatement of indoor air pollution achieved with coal-biomass household briquettes

    NASA Astrophysics Data System (ADS)

    Yamada, Kimiko; Sorimachi, Atsuyuki; Wang, Qingyue; Yi, Jing; Cheng, Shuqun; Zhou, Yanrong; Sakamoto, Kazuhiko

    We investigated the abatement of indoor pollution achieved when two types of coal-biomass briquettes (L-BBs and H-BBs) were used in place of honeycombed coal briquettes (H-coal) in household stoves in rural Chongqing, China. Indoor concentrations of sulfur dioxide (SO 2), carbon monoxide (CO), and gaseous fluoride were measured. Additionally, we evaluated the factors that affected indoor concentrations of these gases, including the amount of fuel used as well as its sulfur content, the sulfur-emission ratio determined from the amount of sulfur retained in the combustion ash, and the combustion temperature in the stoves. The average 8-h and 24-h SO 2 concentrations for L-BBs were nearly equal to or less than the World Health Organization's 40 ppb guideline, whereas those for H-coal and H-BBs exceeded the guideline. The average 8-h SO 2 concentrations for L-BBs were from 63 to 89% lower than those for H-coal, even though the 8-h average weight of fuel and its sulfur content for L-BBs were equal to those of H-coal. A chemical analysis of combustion ash indicated that the sulfur-emission ratio was from 26 to 48% for L-BBs, as compared with 86% for H-coal, and this difference resulted in reduction of indoor SO 2 concentrations for L-BBs as compared with H-coal. Most of the 8-h average concentrations of CO and gaseous fluoride for all fuels were lower than the WHO guidelines. We concluded that BBs are a useful domestic fuel for the abatement of indoor air pollution.

  15. Detection of potential leakage pathways from geological carbon storage by fluid pressure data assimilation

    NASA Astrophysics Data System (ADS)

    González-Nicolás, Ana; Baù, Domenico; Alzraiee, Ayman

    2015-12-01

    One of the main concerns of geological carbon storage (GCS) systems is the risk of leakage through "weak" permeable areas of the sealing formation or caprock. Since the fluid pressure pulse travels faster than the carbon dioxide (CO2) plume across the storage reservoir, the fluid overpressure transmitted into overlying permeable formations through caprock discontinuities is potentially detectable sooner than actual CO2 leakage occurs. In this work, an inverse modeling method based on fluid pressure measurements collected in strata above the target CO2 storage formation is proposed, which aims at identifying the presence, the location, and the extent of possible leakage pathways through the caprock. We combine a three-dimensional subsurface multiphase flow model with ensemble-based data assimilation algorithms to recognize potential caprock discontinuities that could undermine the long-term safety of GCS. The goal of this work is to examine and compare the capabilities of data assimilation algorithms such as the ensemble smoother (ES) and the restart ensemble Kalman filter (REnKF) to detect the presence of brine and/or CO2 leakage pathways, potentially in real-time during GCS operations. For the purpose of this study, changes in fluid pressure in the brine aquifer overlying to CO2 storage formation aquifer are hypothetically observed in monitoring boreholes, or provided by time-lapse seismic surveys. Caprock discontinuities are typically characterized locally by higher values of permeability, so that the permeability distribution tends to fit to a non-Gaussian bimodal process, which hardly complies with the requirements of the ES and REnKF algorithms. Here, issues related to the non-Gaussianity of the caprock permeability field are investigated by developing and applying a normal score transform procedure. Results suggest that the REnKF is more effective than the ES in characterizing caprock discontinuities.

  16. Carbon storage capacity of semi-arid grassland soils and sequestration potentials in northern China.

    PubMed

    Wiesmeier, Martin; Munro, Sam; Barthold, Frauke; Steffens, Markus; Schad, Peter; Kögel-Knabner, Ingrid

    2015-10-01

    Organic carbon (OC) sequestration in degraded semi-arid environments by improved soil management is assumed to contribute substantially to climate change mitigation. However, information about the soil organic carbon (SOC) sequestration potential in steppe soils and their current saturation status remains unknown. In this study, we estimated the OC storage capacity of semi-arid grassland soils on the basis of remote, natural steppe fragments in northern China. Based on the maximum OC saturation of silt and clay particles <20 μm, OC sequestration potentials of degraded steppe soils (grazing land, arable land, eroded areas) were estimated. The analysis of natural grassland soils revealed a strong linear regression between the proportion of the fine fraction and its OC content, confirming the importance of silt and clay particles for OC stabilization in steppe soils. This relationship was similar to derived regressions in temperate and tropical soils but on a lower level, probably due to a lower C input and different clay mineralogy. In relation to the estimated OC storage capacity, degraded steppe soils showed a high OC saturation of 78-85% despite massive SOC losses due to unsustainable land use. As a result, the potential of degraded grassland soils to sequester additional OC was generally low. This can be related to a relatively high contribution of labile SOC, which is preferentially lost in the course of soil degradation. Moreover, wind erosion leads to substantial loss of silt and clay particles and consequently results in a direct loss of the ability to stabilize additional OC. Our findings indicate that the SOC loss in semi-arid environments induced by intensive land use is largely irreversible. Observed SOC increases after improved land management mainly result in an accumulation of labile SOC prone to land use/climate changes and therefore cannot be regarded as contribution to long-term OC sequestration. PMID:25916410

  17. The economics of soil C sequestration and agricultural emissions abatement

    NASA Astrophysics Data System (ADS)

    Alexander, P.; Paustian, K.; Smith, P.; Moran, D.

    2015-04-01

    Carbon is a critical component of soil vitality and is crucial to our ability to produce food. Carbon sequestered in soils also provides a further regulating ecosystem service, valued as the avoided damage from global climate change. We consider the demand and supply attributes that underpin and constrain the emergence of a market value for this vital global ecosystem service: markets being what economists regard as the most efficient institutions for allocating scarce resources to the supply and consumption of valuable goods. This paper considers how a potentially large global supply of soil carbon sequestration is reduced by economic and behavioural constraints that impinge on the emergence of markets, and alternative public policies that can efficiently transact demand for the service from private and public sector agents. In essence, this is a case of significant market failure. In the design of alternative policy options, we consider whether soil carbon mitigation is actually cost-effective relative to other measures in agriculture and elsewhere in the economy, and the nature of behavioural incentives that hinder policy options. We suggest that reducing the cost and uncertainties of mitigation through soil-based measures is crucial for improving uptake. Monitoring and auditing processes will also be required to eventually facilitate wide-scale adoption of these measures.

  18. The public health relevance of air pollution abatement.

    PubMed

    Künzli, N

    2002-07-01

    Assuming a causal relationship between current levels of air pollution and morbidity/mortality, it is crucial to estimate the public health relevance of the problem. The derivation of air pollution attributable cases faces inherent uncertainties and requires influential assumptions. Based on the results of the trinational impact assessment study of Austria, France, and Switzerland, where prudent estimates of the air pollution attributable cases (mortality, chronic bronchitis incidence, hospital admissions, acute bronchitis among children, restricted activity days, asthma attacks) have been made, influential uncertainties are quantified in this review. The public health impact of smoking, environmental tobacco smoke, and air pollution on the prevalence of chronic cough/phlegm are outlined. Despite all methodological caveats, impact assessment studies clearly suggest that public health largely benefits from better air quality. The studies are selective underestimates as they are strongly driven by mortality, but do not include full quantification of the impact on morbidity and their consequences on quality of life among the diseased and the caregivers. Air pollution abatement strategies are usually political in nature, targeting at polities, regulation and technology in mobile or stationary sources rather than at individuals. It is of note that key clean air strategies converge into abatement of climate change. In general, energy consumption is very closely related to both air pollution and greenhouse gases. The dominant causes of both problems are the excessive and inefficient combustion of fossil fuel. Thus, for many policy options, the benefit of air pollution abatement will go far beyond what prudent health-impact assessments may derive. From a climate change and air pollution perspective, improved energy efficiency and a strong and decisive departure from the "fossil fuel" combustion society is a science-based must. Health professionals must raise their voices

  19. Forest Management Shifts in the Western US and Potential Impacts on the Carbon Balance

    NASA Astrophysics Data System (ADS)

    Law, B. E.; Jones, M. O.; Yang, Z.; Berner, L. T.

    2015-12-01

    Forest harvest regimes are changing as land managers cope with fires, drought, and insect damage. Thinning on public lands, typically focused on removal of small trees that could act as fuel ladders, is increasing to reduce risk of crown fires and reduce competition for water in crowded stands. On private lands, drought and wildfires could lead to further shortening of harvest cycles (e.g. from 80 to 45 years) or thinning. To examine the effects of potential changes in management regimes vs climate on carbon processes in forests of Oregon, California and Washington, we used data from ancillary plots, inventories, and satellites to parameterize and test the CLM4.5 model. We first examined contemporary biomass loss over the western US to determine the baseline conditions prior to implementing harvest scenarios. Annual biomass mortality from fires and insects increased significantly (1996-2011), and mortality from insects was about twice that of fires. California, Oregon and Idaho were most impacted by fire-related biomass mortality, whereas Colorado, Montana and Washington were most impacted by insects. Harvest scenarios implemented in CLM4.5 include two thinning scenarios to reduce crown fire risk and drought stress, and a salvage scenario to remove trees remaining after recent beetle or fire related mortality; taking into account our previous work showing 70 - 85 % of salvaged biomass is removed and the remainder is left on-site. We simulated the effect of treatments on current and future net ecosystem carbon balance. Challenges of regional modeling of management effects on carbon and other important considerations are addressed.

  20. 12 Years of NPK Addition Diminishes Carbon Sink Potential of a Nutrient Limited Peatland

    NASA Astrophysics Data System (ADS)

    Larmola, T.; Bubier, J. L.; Juutinen, S.; Moore, T. R.

    2011-12-01

    Peatlands store about a third of global soil carbon. Our aim was to study whether the vegetation feedbacks of nitrogen (N) deposition lead to stronger carbon sink or source in a nutrient limited peatland ecosystem. We investigated vegetation structure and ecosystem CO2 exchange at Mer Bleue Bog, Canada, that has been fertilized for 7-12 years. We have applied 5 and 20 times ambient annual wet N deposition (0.8 g N m-2) with or without phosphorus (P) and potassium (K). Gross photosynthesis, ecosystem respiration and net CO2 exchange (NEE) were measured weekly during the growing season using chamber technique. Under the highest N(PK) treatments, the light saturated photosynthesis (PSmax) was reduced by 20-30% compared to the control treatment, whereas under moderate N and PK additions PSmax slightly increased or was similar to the control. The ecosystem respiration showed similar trends among the treatments, but changes in the rates were less pronounced. High nutrient additions led to up to 65% lower net CO2 uptake than that in the control: In the NPK plots with cumulative N additions of 70, 19, and 0 g N m-2, the daytime NEE in May-July 2011 averaged 0.8 (se. 0.3), 2.0 (se. 0.4), and 2.4 (se. 0.3) μmol m-2 s-1, respectively. In the N only plots with cumulative N additions of 45, 19, and 0 g N m-2, the daytime NEE in May-July 2011 averaged 0.8 (se. 0.2), 2.6 (se. 0.4), and 1.8 (se. 0.3) μmol m-2 s-1, respectively. The reduced plant photosynthetic capacity and diminished carbon sink potential in the highest nutrient treatments correlated with the loss of peat mosses and were not compensated for by the increased vascular plant biomass that has mainly been allocated to woody shrub stems.

  1. Functionalized carbon nanomaterials: exploring the interactions with Caco-2 cells for potential oral drug delivery

    PubMed Central

    Coyuco, Jurja C; Liu, Yuanjie; Tan, Bee-Jen; Chiu, Gigi NC

    2011-01-01

    Although carbon nanomaterials (CNMs) have been increasingly studied for their biomedical applications, there is limited research on these novel materials for oral drug delivery. As such, this study aimed to explore the potential of CNMs in oral drug delivery, and the objectives were to evaluate CNM cytotoxicity and their abilities to modulate paracellular transport and the P-glycoprotein (P-gp) efflux pump. Three types of functionalized CNMs were studied, including polyhydroxy small-gap fullerenes (OH-fullerenes), carboxylic acid functionalized single-walled carbon nanotubes (f SWCNT-COOH) and poly(ethylene glycol) functionalized single-walled carbon nanotubes (f SWCNT-PEG), using the well-established Caco-2 cell monolayer to represent the intestinal epithelium. All three CNMs had minimum cytotoxicity on Caco-2 cells, as demonstrated through lactose dehydrogenase release and 3-(4,5-dimethyliazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. Of the three CNMs, f SWCNT-COOH significantly reduced transepithelial electrical resistance and enhanced transport of Lucifer Yellow across the Caco-2 monolayer. Confocal fluorescence microscopy showed that f SWCNT-COOH treated cells had the highest perturbation in the distribution of ZO-1, a protein marker of tight junction, suggesting that f SWCNT-COOH could enhance paracellular permeability via disruption of tight junctions. This modulating effect of f SWCNT-COOH can be reversed over time. Furthermore, cellular accumulation of the P-gp substrate, rhodamine-123, was significantly increased in cells treated with f SWCNT-COOH, suggestive of P-gp inhibition. Of note, f SWCNT-PEG could increase rhodamine-123 accumulation without modifying the tight junction. Collectively, these results suggest that the functionalized CNMs could be useful as modulators for oral drug delivery, and the differential effects on the intestinal epithelium imparted by different types of CNMs would create unique opportunities for drug-specific oral

  2. Thermal characteristics of oleochemical carbonate binary mixtures for potential latent heat storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The present study examines the thermal properties of melting and solidification for binary mixtures between dodecyl carbonate (1a), tetradecyl carbonate (1b), hexadecyl carbonate (1c), and octadecyl carbonate (1d) by differential scanning calorimetry (DSC) in order to gain further understanding of t...

  3. Toward a Comprehensive Carbon Budget for North America: Potential Applications of Adjoint Methods with Diverse Datasets

    NASA Technical Reports Server (NTRS)

    Andrews, A.

    2002-01-01

    A detailed mechanistic understanding of the sources and sinks of CO2 will be required to reliably predict future COS levels and climate. A commonly used technique for deriving information about CO2 exchange with surface reservoirs is to solve an "inverse problem," where CO2 observations are used with an atmospheric transport model to find the optimal distribution of sources and sinks. Synthesis inversion methods are powerful tools for addressing this question, but the results are disturbingly sensitive to the details of the calculation. Studies done using different atmospheric transport models and combinations of surface station data have produced substantially different distributions of surface fluxes. Adjoint methods are now being developed that will more effectively incorporate diverse datasets in estimates of surface fluxes of CO2. In an adjoint framework, it will be possible to combine CO2 concentration data from long-term surface monitoring stations with data from intensive field campaigns and with proposed future satellite observations. A major advantage of the adjoint approach is that meteorological and surface data, as well as data for other atmospheric constituents and pollutants can be efficiently included in addition to observations of CO2 mixing ratios. This presentation will provide an overview of potentially useful datasets for carbon cycle research in general with an emphasis on planning for the North American Carbon Project. Areas of overlap with ongoing and proposed work on air quality/air pollution issues will be highlighted.

  4. Potential of Global Cropland Phytolith Carbon Sink from Optimization of Cropping System and Fertilization

    PubMed Central

    Song, Zhaoliang; Parr, Jeffrey F.; Guo, Fengshan

    2013-01-01

    The occlusion of carbon (C) by phytoliths, the recalcitrant silicified structures deposited within plant tissues, is an important persistent C sink mechanism for croplands and other grass-dominated ecosystems. By constructing a silica content-phytolith content transfer function and calculating the magnitude of phytolith C sink in global croplands with relevant crop production data, this study investigated the present and potential of phytolith C sinks in global croplands and its contribution to the cropland C balance to understand the cropland C cycle and enhance long-term C sequestration in croplands. Our results indicate that the phytolith sink annually sequesters 26.35±10.22 Tg of carbon dioxide (CO2) and may contribute 40±18% of the global net cropland soil C sink for 1961–2100. Rice (25%), wheat (19%) and maize (23%) are the dominant contributing crop species to this phytolith C sink. Continentally, the main contributors are Asia (49%), North America (17%) and Europe (16%). The sink has tripled since 1961, mainly due to fertilizer application and irrigation. Cropland phytolith C sinks may be further enhanced by adopting cropland management practices such as optimization of cropping system and fertilization. PMID:24066067

  5. Immunotoxicity and allergic potential induced by topical application of dimethyl carbonate (DMC) in a murine model.

    PubMed

    Anderson, Stacey E; Franko, Jennifer; Anderson, Katie L; Munson, Albert E; Lukomska, Ewa; Meade, B Jean

    2013-01-01

    Dimethyl carbonate (DMC) is an industrial chemical, used as a paint and adhesive solvent, with the potential for significant increases in production. Using select immune function assays, the purpose of these studies was to evaluate the immunotoxicity of DMC following dermal exposure using a murine model. Following a 28-day exposure, DMC produced a significant decrease in thymus weight at concentrations of 75% and greater. No effects on body weight, hematological parameters (erythrocytes, leukocytes, and their differentials), or immune cell phenotyping (B-cells, T-cells, and T-cell sub-sets) were identified. The IgM antibody response to sheep red blood cell (SRBC) was significantly reduced in the spleen but not the serum. DMC was not identified to be an irritant and evaluation of the sensitization potential, conducted using the local lymph node assay (LLNA) at concentrations ranging from 50-100%, did not identify increases in lymphocyte proliferation. These results demonstrate that dermal exposure to DMC induces immune suppression in a murine model and raise concern about potential human exposure and the need for occupational exposure regulations. PMID:22953780

  6. Seasonal growth potential of rare lake water bacteria suggest their disproportional contribution to carbon fluxes.

    PubMed

    Neuenschwander, Stefan M; Pernthaler, Jakob; Posch, Thomas; Salcher, Michaela M

    2015-03-01

    We studied the seasonal growth potential of opportunistic bacterial populations in Lake Zurich (Switzerland) by a series of grazer-free dilution culture assays. Pronounced shifts in the composition of the bacterial assemblages were observed within one doubling of total cell numbers, from initially abundant Actinobacteria to other fast-growing microbial lineages. Small populations with growth potentials far above community average were detected throughout the year with striking seasonal differences in their respective taxonomic affiliations. Members of Cytophaga-Flavobacteria (CF) were disproportionally proliferating only during phytoplankton blooms in spring and summer, while Beta- and Gammaproteobacteria showed superior growth at all other occasions. Growth rates of Alphaproteobacteria and esp. Sphingomonadaceae were significantly correlated to water temperatures and were far above community average in summer. Within the genus Flavobacterium, two species-like populations showed a tendency for fast growth in most experiments, while four others were exclusively proliferating either during a spring or during a summer phytoplankton bloom. Their high growth potentials but low in situ abundances hint at a tight control by bacterivorous grazers and at a consequently accelerated carbon flux to higher trophic levels. PMID:24903166

  7. Acting Globally: Potential Carbon Emissions Mitigation Impacts from an International Standards and Labelling Program

    SciTech Connect

    McNeil, Michael A; Letschert, Virginie E.; de la Rue du Can, Stephane; Egan, Christine

    2009-05-29

    This paper presents an analysis of the potential impacts of an international initiative designed to support and promote the development and implementation of appliances standards and labelling programs throughout the world. As part of previous research efforts, LBNL developed the Bottom Up Energy Analysis System (BUENAS), an analysis framework that estimates impact potentials of energy efficiency policies on a global scale. In this paper, we apply this framework to an initiative that would result in the successful implementation of programs focused on high priority regions and product types, thus evaluating the potential impacts of such an initiative in terms of electricity savings and carbon mitigation in 2030. In order to model the likely parameters of such a program, we limit impacts to a five year period starting in 2009, but assume that the first 5 years of a program will result in implementation of 'best practice' minimum efficiency performance standards by 2014. The 'high priority' regions considered are: Brazil, China, the European Union,India, Mexico and the United States. The products considered are: refrigerators, air conditioners, lighting (both fluorescent and incandescent), standby power (for consumer electronics) and televisions in the residential sector, and air conditioning and lighting in commercial buildings. In 2020, these regions and enduses account for about 37percent of global residential electricity and 29percent of electricity in commercial buildings. We find that 850Mt of CO2 could be saved in buildings by 2030 compared to the baseline forecast.

  8. Mafic Atlas: Looking at basalt rock formations for potential carbon sequestration application

    DOE Data Explorer

    Basalt formations are prevalent in the Big Sky region, and while less studied than other potential storage sites for CO2, they may play an important role in geologic sequestration due to their unique geochemical and physical properties. Regionally, basalts offer significant long-term storage potential estimated in the range of 33-134 billion metric tons. These estimates scaled globally suggest that the five largest basalt provinces could sequester 10,000 years of the world’s CO2 emissions. Basalt provinces are globally distributed and could significantly expand CO2 storage options in regions where conventional storage is limited or non-existent. BSCSP and Idaho State University developed a national Mafic Atlas to assess the sequestration potential of basalts through modeling studies, laboratory testing, and insights developed from mafic rock pilot projects. The Mafic Atlas online mapping application highlights the Columbia River Basalt Group in Washington and Oregon and its proximity to the West Coast power load. Features of the map include: • Carbon storage capacity estimates for regional basalt provinces • Click-able well locations that link to US Geological Survey well log datasets • Live GeoRSS feeds and an address finder • Custom drawing and printing tools to create your own map • Search tools to explore the Mafic database. [copied from http://www.bigskyco2.org/atlas/mafic

  9. Potential routes to carbon inclusion in apatite minerals: a DFT study

    NASA Astrophysics Data System (ADS)

    Rabone, J. A. L.; de Leeuw, N. H.

    2007-09-01

    We have conducted a computational study to investigate a number of possible routes for the incorporation of carbon into apatites. Using density functional theory (DFT) we have calculated geometry optimised structures for fluor- and hydroxy-apatites with and without various substitutions. We have studied several different carbonate substitutions, pure carbonate and pure formate apatites, neutral carbon atoms occupying interstices, and carbon dioxide and acetylene absorbed in oxyapatite.

  10. [Estimation of Topsoil Carbon Sequestration Potential of Cropland Through Different Methods: A Case Study in Zhuanglang County, Gansu Province].

    PubMed

    Shi, Chen-di; Xu, Ming-xiang; Qiu, Yu-jie

    2016-03-15

    By analyzing the sampled data and the SOC data of the second national soil survey by the mid 80s and the national cultivated land quality evaluation in 2006 in Zhuanglang County, the article studied the cropland topsoil organic carbon sequestration potential estimation using several different methods. The results showed that: (1) There was no significant difference among different estimation methods about cropland carbon sequestration potential in the same region. Taking cropland carbon sequestration potential in Zhuanglang County for example, the theoretical values estimated by maximum value method and classification grading method were 1. 13 Mt and 1.09 Mt, respectively. (2) The real values estimated by classification grading method, saturation method, weighting method were 0.37 Mt, 0.32 Mt, 0.28 Mt, respectively, which were about 1/3 of the theoretical value. (3) The SOC density increments to reach the real level of carbon sequestration potential estimated by classification grading method, saturation method and weighting method were 6.76 t · hm⁻², 5.21 t · hm⁻², 4.56 t · hm⁻² respectively. According to the topsoil carbon sequestration rate of cropland in Zhuanglang county in the recent 30 a, it would need about 24-34 a to achieve the real level. (4) At the county scale, the weighted method was superior to the saturation value method, and the saturation value method was better than the classification grading method in the actual carbon sequestration potential estimation. The classification grading method was better than the maximum value method in the ideal carbon sequestration potential estimation. PMID:27337906

  11. After the Storm: Assessing the carbon and nitrogen leaching potential from sediments deposited in aquatic ecosystems

    NASA Astrophysics Data System (ADS)

    Johnson, E. R.; Krieg, C.; Canning, C.; Inamdar, S. P.; Rowland, R. D.

    2015-12-01

    The erosive energy of large storms can mobilize, and subsequently deposit large amounts of sediment in receiving aquatic ecosystems. Depending on the character of the sediments there is potential for leaching or sequestration of carbon (C) and nitrogen (N) from the sediments. This could have significant implications for water quality, aquatic metabolism, and global cycling of C and N. This study examines the fate of these sediments by: (1) determining the amount and quality of organic matter that can be leached into the surrounding water from coarse, medium and fine particle classes (2) assessing the C and N contents of various particles classes and the sources of the sediment through isotopic composition. Bed sediment samples were collected along a 1-2nd order stream (eight locations) in a forested catchment in the Piedmont region of Maryland following a large storm event. Samples were sieved into three particle classes - coarse (2mm-1mm), medium (1mm-250µm) and fine (<250µm). Extractions were performed for each of three particle class sizes by leaching with DI water. Organic matter composition for the extracts was characterized using fluorescence. Stable isotopes of 13C and 15N were determined for bed sediment classes and upland source sediments to identify the origins of the eroded sediments. Extracts with low C:N ratios that also exhibit a higher percent protein and lower percent humic carbon content are considered most labile. Within the bed sediment deposits, differences were found in the distribution of labile compounds between each particle class size. Generally, course particle size exhibited the most labile characteristics, closely followed by medium particle size. Fine particle size exhibited the most refractory characteristics in all locations. These results are critical since climate-change predictions reveal more intense and large storms for the northeast US, with potentially greater impacts on aquatic ecosystems from eroded upland sediments.

  12. Distribution of organic carbon and petroleum source rock potential of Cretaceous and lower Tertiary carbonates, South Florida Basin: preliminary results

    USGS Publications Warehouse

    Palacas, James George

    1978-01-01

    Analyses of 134 core samples from the South Florida Basin show that the carbonates of Comanchean age are relatively richer in average organic carbon (0.41 percent) than those of Coahuilan age (0.28 percent), Gulfian age (0.18 percent) and Paleocene age (0.20 percent). They are also nearly twice as rich as the average world, wide carbonate (average 0.24 percent). The majority of carbonates have organic carbons less than 0.30 percent but the presence of many relatively organic rich beds composed of highly bituminous, argillaceous, highly stylolitic, and algal-bearing limestones and dolomites accounts for the higher percentage of organic carbon in some of the stratigraphic units. Carbonate rocks that contain greater than 0.4 percent organic carbon and that might be considered as possible petroleum sources were noted in almost each subdivision of the Coahuilan and Comanchean Series but particularly the units of Fredericksburg 'B', Trinity 'A', Trinity 'F', and Upper Sunniland. Possible source rocks have been ascribed by others to the Lower Sunniland, but lack of sufficient samples precluded any firm assessment in this initial report. In the shallower section of the basin, organic-rich carbonates containing as much as 3.2 percent organic carbon were observed in the lowermost part of the Gulfian Series and carbonate rocks with oil staining or 'dead' and 'live oil' were noted by others in the uppermost Gulfian and upper Cedar Keys Formation. It is questionable whether these shallower rocks are of sufficient thermal maturity to have generated commercial oil. The South Florida basin is still sparsely drilled and produces only from the Sunniland Limestone at an average depth of 11,500 feet (3500 m). Because the Sunniland contains good reservoir rocks and apparently adequate source rocks, and because the success rate of new oil field discoveries has increased in recent years, the chances of finding additional oil reserves in the Sunniland are promising. Furthermore, the

  13. Restoration and Carbon Sequestration Potential of Sub-Humid Shrublands in a Changing Climate

    NASA Astrophysics Data System (ADS)

    Adhikari, A.; White, J. D.

    2014-12-01

    per ha for the projected higher emission scenarios compared to lower emission scenarios. We conclude that restoration efforts within LRGV have contributed to increasing shrub density and sequestering carbon in tissue biomass, but future climate change is likely to reduce its carbon sequestration potential.

  14. Microbial community responses to temperature increase the potential for soil carbon losses under climate change.

    NASA Astrophysics Data System (ADS)

    Hartley, Iain; Karhu, Kristiina; Auffret, Marc; Hopkins, David; Prosser, Jim; Singh, Brajesh; Subke, Jens-Arne; Wookey, Philip; Ågren, Göran

    2014-05-01

    There are concerns that global warming may stimulate decomposition rates in soils, with the extra CO2 released representing a positive feedback to climate change. However, there is growing recognition that adaptation of soil microbial communities to temperature changes may alter the potential rate of carbon release. Critically, recent studies have produced conflicting results in terms of whether the medium-term soil microbial community response to temperature reduces (compensatory thermal adaptation) or enhances (enhancing thermal adaptation) the instantaneous direct positive effects of temperature on microbial activity. This lack of understanding adds considerably to uncertainty in predictions of the magnitude and direction of carbon-cycle feedbacks to climate change. In this talk, I present results from one of the most extensive investigations ever undertaken into the role that microbial adaptation plays in controlling the temperature sensitivity of decomposition. Soils were collected from a range of ecosystem types, representing a thermal gradient from the Arctic to the Amazon. Our novel soil-cooling approach minimises issues associated with substrate depletion in warming studies, but still tests whether adaptation enhances or reduces the direct impact of temperature changes on microbial activity. We also investigated the mechanisms underlying changes in microbial respiration by quantifying changes in microbial community composition, microbial biomass, mass-specific activity, carbon-use efficiency, and enzyme activities. Our results indicate that enhancing responses are much more common than compensatory thermal acclimation, with the latter being observed in less than 10% of cases. However, identifying the mechanisms underlying enhancing and compensatory adaptation remained elusive. No consistent changes were observed in terms of mass-specific activity, biomass or enzyme activity, indicating that current theory is inadequate in explaining observed patterns

  15. Deep horizons: Soil Carbon sequestration and storage potential in grassland soils

    NASA Astrophysics Data System (ADS)

    Torres-Sallan, Gemma; Schulte, Rogier; Lanigan, Gary J.; Byrne, Kenneth A.; Reidy, Brian; Creamer, Rachel

    2016-04-01

    Soil Organic Carbon (SOC) enhances soil fertility, holding nutrients in a plant-available form. It also improves aeration and water infiltration. Soils are considered a vital pool for C (Carbon) sequestration, as they are the largest pool of C after the oceans, and contain 3.5 more C than the atmosphere. SOC models and inventories tend to focus on the top 30 cm of soils, only analysing total SOC values. Association of C with microaggregates (53-250 μm) and silt and clay (<53 μm) is considered C sequestration as these fractions offer the greatest protection against mineralization. This study assessed the role of aggregation in C sequestration throughout the profile, down to 1 m depth, of 30 grassland sites divided in 6 soil types. One kg sample was collected for each horizon, sieved at 8 mm and dried at 40 °C. Through a wet sieving procedure, four aggregate sizes were isolated: large macroaggregates (>2000 μm); macroaggregates (250-2000 μm); microaggregates and silt & clay. Organic C associated to each aggregate fraction was analysed on a LECO combustion analyser. Sand-free C was calculated for each aggregate size. For all soil types, 84% of the SOC located in the first 30 cm was contained inside macroaggregates and large macroaggregates. Given that this fraction has a turnover time of 1 to 10 years, sampling at that depth only provides information on the labile fraction in soil, and does not consider the longer term C sequestration potential. Only when looking at the whole profile, two clear trends could be observed: 1) soils with a clay increase at depth had most of their C located in the silt and clay fractions, which indicate their enhanced C sequestration capacity, 2) free-draining soils had a bigger part of their SOC located in the macroaggregate fractions. These results indicate that current C inventories and models that focus on the top 30 cm, do not accurately measure soil C sequestration potential in soils, but rather the more labile fraction. However

  16. Potential flue gas impurities in carbon dioxide streams separated from coal-fired power plants.

    PubMed

    Lee, Joo-Youp; Keener, Tim C; Yang, Y Jeffery

    2009-06-01

    For geological sequestration of carbon dioxide (CO2) separated from pulverized coal combustion flue gas, it is necessary to adequately evaluate the potential impacts of flue gas impurities on groundwater aquifers in the case of the CO2 leakage from its storage sites. This study estimated the flue gas impurities to be included in the CO2 stream separated from a CO2 control unit for a different combination of air pollution control devices and different flue gas compositions. Specifically, the levels of acid gases and mercury vapor were estimated for the monoethanolamine (MEA)-based absorption process on the basis of published performance parameters of existing systems. Among the flue gas constituents considered, sulfur dioxide (SO2) is known to have the most adverse impact on MEA absorption. When a flue gas contains 3000 parts per million by volume (ppmv) SO2 and a wet flue gas desulfurization system achieves its 95% removal, approximately 2400 parts per million by weight (ppmw) SO2 could be included in the separated CO2 stream. In addition, the estimated concentration level was reduced to as low as 135 ppmw for the SO2 of less than 10 ppmv in the flue gas entering the MEA unit. Furthermore, heat-stable salt formation could further reduce the SO2 concentration below 40 ppmw in the separated CO2 stream. In this study, it is realized that the formation rates of heat-stable salts in MEA solution are not readily available in the literature and are critical to estimating the levels and compositions of flue gas impurities in sequestered CO2 streams. In addition to SO2, mercury, and other impurities in separated CO2 streams could vary depending on pollutant removal at the power plants and impose potential impacts on groundwater. Such a variation and related process control in the upstream management of carbon separation have implications for groundwater protection at carbon sequestration sites and warrant necessary considerations in overall sequestration planning

  17. Biochar erosion: A potential threat to its suitability for carbon sequestration?

    NASA Astrophysics Data System (ADS)

    Fister, W.; Heckrath, G.; Greenwood, P.; Kuhn, N. J.

    2013-12-01

    Biochar is often considered to be a ';soft' geo-engineering option, with the potential to encourage soils to sequester more carbon (C) from the atmospheric C pool, and so increase both medium- and long-term soil C stocks. Similar to soil organic carbon (SOC), biochar has a lower bulk density than typical agricultural soils. Therefore, the question about its preferential mobilization and redistribution in the landscape has been raised in recent years. This is especially relevant on soils, which are regularly cultivated and are vulnerable to soil erosion themselves. However, so far few studies about the erodibility and fate of biochar in the landscape exist and the answer to this question is still unknown. Since the efficacy of biochar for sequestering carbon and improving soil quality depends on its amount and residential time in the upper soil matrix, it is important to further our knowledge about mobilization and transport behaviour of biochar. Moreover, such knowledge could have profound economic implications for farmers committed to its use, as a high net annual loss of biochar by erosion could exceed any net annual economic gain. The overall objective of this study was, therefore, to investigate the erodibility of biochar, when erosion events occur directly or soon after its application. The estimation of the financial value of the eroded biochar and its cost-effectiveness were scaled up from plot to field scale. In this investigation, the biochar was applied to the soil surface of three plots on a recently cultivated sandy field near Viborg in northern Jutland, Denmark at concentrations equivalent to 1.5-2.0 kg m-2. After application, the biochar was manually incorporated into the till-zone (20cm). Three consecutive erosion events (each lasted for 30 min. with rainfall intensity of approx. 90 mm h-1) were conducted on both biochar and reference plots. The erosion events were generated by the 2.2 m-2 Portable Wind and Rainfall Simulator. The preliminary results

  18. Evaluation and assessment of the efficacy of an abatement strategy in a former lead smelter community, Boolaroo, Australia.

    PubMed

    Harvey, P J; Taylor, M P; Kristensen, L J; Grant-Vest, S; Rouillon, M; Wu, L; Handley, H K

    2016-08-01

    This study examines the recent soil Lead Abatement Strategy (LAS) in Boolaroo, New South Wales, Australia, that was designed to "achieve a reduction in human exposure to lead dust contamination in surface soils". The abatement programme addressed legacy contamination of residential areas following closure of lead smelting operations in 2003 at the Pasminco Cockle Creek Smelter (PCCS). The principal objective of the LAS was to "cap and cover" lead-contaminated soils within the urban environment surrounding the PCCS. Soil lead concentrations of 2500-5000 mg/kg were scheduled for removal and replacement, while concentrations between 1500 and 2500 mg/kg were replaced only under limited circumstances. To date, there has been no industry, government or independent assessment of the clean-up programme that involved >2000 homes in the township of Boolaroo. Thus, by measuring post-abatement soil lead concentrations in Boolaroo, this study addresses this knowledge gap and evaluates the effectiveness of the LAS for reducing the potential for lead exposure. Soil lead concentrations above the Australian residential soil health investigation level value for residential soils (300 mg/kg) were identified at all but one of the residential properties examined (n = 19). Vacuum dust samples (n = 17) from the same homes had a mean lead concentration of 495 mg/kg (median 380 mg/kg). Bio-accessibility testing revealed that lead in household vacuum dust was readily accessible (% bio-accessible) (mean = 92 %, median = 90 %), demonstrating that the risk of exposure via this pathway remains. Assessment of a limited number of properties (n = 8) where pre-abatement soil lead levels were available for comparison showed they were not statistically different to post-abatement. Although the LAS did not include treatment of non-residential properties, sampling of community areas including public sports fields, playgrounds and schools (n = 32) was undertaken to determine the

  19. Climate and soil properties limit the positive effects of land use reversion on carbon storage in Eastern Australia

    NASA Astrophysics Data System (ADS)

    Rabbi, S. M. F.; Tighe, Matthew; Delgado-Baquerizo, Manuel; Cowie, Annette; Robertson, Fiona; Dalal, Ram; Page, Kathryn; Crawford, Doug; Wilson, Brian R.; Schwenke, Graeme; McLeod, Malem; Badgery, Warwick; Dang, Yash P.; Bell, Mike; O'Leary, Garry; Liu, De Li; Baldock, Jeff

    2015-12-01

    Australia’s “Direct Action” climate change policy relies on purchasing greenhouse gas abatement from projects undertaking approved abatement activities. Management of soil organic carbon (SOC) in agricultural soils is an approved activity, based on the expectation that land use change can deliver significant changes in SOC. However, there are concerns that climate, topography and soil texture will limit changes in SOC stocks. This work analyses data from 1482 sites surveyed across the major agricultural regions of Eastern Australia to determine the relative importance of land use vs. other drivers of SOC. Variation in land use explained only 1.4% of the total variation in SOC, with aridity and soil texture the main regulators of SOC stock under different land uses. Results suggest the greatest potential for increasing SOC stocks in Eastern Australian agricultural regions lies in converting from cropping to pasture on heavy textured soils in the humid regions.

  20. Climate and soil properties limit the positive effects of land use reversion on carbon storage in Eastern Australia

    PubMed Central

    Rabbi, S.M.F.; Tighe, Matthew; Delgado-Baquerizo, Manuel; Cowie, Annette; Robertson, Fiona; Dalal, Ram; Page, Kathryn; Crawford, Doug; Wilson, Brian R.; Schwenke, Graeme; Mcleod, Malem; Badgery, Warwick; Dang, Yash P.; Bell, Mike; O’Leary, Garry; Liu, De Li; Baldock, Jeff

    2015-01-01

    Australia’s “Direct Action” climate change policy relies on purchasing greenhouse gas abatement from projects undertaking approved abatement activities. Management of soil organic carbon (SOC) in agricultural soils is an approved activity, based on the expectation that land use change can deliver significant changes in SOC. However, there are concerns that climate, topography and soil texture will limit changes in SOC stocks. This work analyses data from 1482 sites surveyed across the major agricultural regions of Eastern Australia to determine the relative importance of land use vs. other drivers of SOC. Variation in land use explained only 1.4% of the total variation in SOC, with aridity and soil texture the main regulators of SOC stock under different land uses. Results suggest the greatest potential for increasing SOC stocks in Eastern Australian agricultural regions lies in converting from cropping to pasture on heavy textured soils in the humid regions. PMID:26639009

  1. Introduction to the Biological Monitoring and Abatement Program

    SciTech Connect

    Peterson, Mark J

    2011-01-01

    This paper provides an introduction to a long-term biological monitoring program and the Environmental Management special issue titled Long-term Biological Monitoring of an Impaired Stream: Implications for Environmental Management. The Biological Monitoring and Abatement Program, or BMAP, was implemented to assess biological impairment downstream of U.S. Department of Energy (DOE) facilities in Oak Ridge, Tennessee, beginning in 1985. Several of the unique aspects of the program include its long-term consistent sampling, a focus on evaluating the effectiveness of specific facility abatement and remedial actions, and the use of quantitative sampling protocols using a multidisciplinary approach. This paper describes the need and importance of long-term watershed-based biological monitoring strategies, in particular for addressing long-term stewardship goals at DOE sites, and provides a summary of the BMAP's objectives, spatial and temporal extent, and overall focus. The primary components of the biological monitoring program for East Fork Poplar Creek in Oak Ridge, Tennessee are introduced, as are the additional 9 papers in this Environmental Management special issue.

  2. Styrene emission abatement in a bathtub manufacturing plant

    SciTech Connect

    Niezgodski, D.M.

    1997-12-31

    EPA is moving forward on promulgating the National Emission Standard for Hazardous Air Pollutants (NESHAP-MACT) for the Reinforced Plastics/Composites Source Category which affects styrene emitters like the American Standard plant. While most composites manufacturers are taking a wait and see approach, American Standard realized the need to move foreward with the controls. Styrene has a reputation of being a difficult VOC to abate. Most adsorption technologies shy away from this monomer due to reactions that cause fires. Weatherly refined their treatment of styrene emissions with experience from installations at similar plants in Europe. Weatherly installed a 35,000 scfm concentrator/oxidation Polyad{trademark} system in 1996 at American Standard`s bathtub manufacturing plant in Salem, Ohio. The styrene emissions are captured in the spray booth exhaust and discharged to the Polyad{trademark} system. The system is achieving 93% removal efficiency on the styrene emissions. This paper will describe the Weatherly Polyad{trademark} VOC abatement system at American Standard`s Salem Ohio plant.

  3. A review of carbon nanotube toxicity and assessment of potential occupational and environmental health risks.

    PubMed

    Lam, Chiu-Wing; James, John T; McCluskey, Richard; Arepalli, Sivaram; Hunter, Robert L

    2006-03-01

    Nanotechnology has emerged at the forefront of science research and technology development. Carbon nanotubes (CNTs) are major building blocks of this new technology. They possess unique electrical, mechanical, and thermal properties, with potential wide applications in the electronics, computer, aerospace, and other industries. CNTs exist in two forms, single-wall (SWCNTs) and multi-wall (MWCNTs). They are manufactured predominately by electrical arc discharge, laser ablation and chemical vapor deposition processes; these processes involve thermally stripping carbon atoms off from carbon-bearing compounds. SWCNT formation requires catalytic metals. There has been a great concern that if CNTs, which are very light, enter the working environment as suspended particulate matter (PM) of respirable sizes, they could pose an occupational inhalation exposure hazard. Very recently, MWCNTs and other carbonaceous nanoparticles in fine (<2.5 microm) PM aggregates have been found in combustion streams of methane, propane, and natural-gas flames of typical stoves; indoor and outdoor fine PM samples were reported to contain significant fractions of MWCNTs. Here we review several rodent studies in which test dusts were administered intratracheally or intrapharyngeally to assess the pulmonary toxicity of manufactured CNTs, and a few in vitro studies to assess biomarkers of toxicity released in CNT-treated skin cell cultures. The results of the rodent studies collectively showed that regardless of the process by which CNTs were synthesized and the types and amounts of metals they contained, CNTs were capable of producing inflammation, epithelioid granulomas (microscopic nodules), fibrosis, and biochemical/toxicological changes in the lungs. Comparative toxicity studies in which mice were given equal weights of test materials showed that SWCNTs were more toxic than quartz, which is considered a serious occupational health hazard if it is chronically inhaled; ultrafine carbon black

  4. Maximizing Amazonia's Ecosystem Services: Juggling the potential for carbon storage, agricultural yield and biodiversity in the Amazon

    NASA Astrophysics Data System (ADS)

    O'Connell, C. S.; Foley, J. A.; Gerber, J. S.; Polasky, S.

    2011-12-01

    The Amazon is not only an exceptionally biodiverse and carbon-rich tract of tropical forest, it is also a case study in land use change. Over the next forty years it will continue to experience pressure from an urbanizing and increasingly affluent populace: under a business-as-usual scenario, global cropland, pasture and biofuels systems will carry on expanding, while the Amazon's carbon storage potential will likely become another viable revenue source under REDD+. Balancing those competing land use pressures ought also take into account Amazonia's high - but heterogeneous - biodiversity. Knowing where Amazonia has opportunities to make efficient or optimal trade offs between carbon storage, agricultural production and biodiversity can allow policymakers to direct or influence LUC drivers. This analysis uses a spatially-explicit model that takes climate and management into account to quantify the potential agricultural yield of both the Amazon's most important agricultural commodities - sugar, soy and maize - as well as several that are going to come into increasing prominence, including palm oil. In addition, it maps the potential for carbon to be stored in forest biomass and relative species richness across Amazonia. We then compare carbon storage, agricultural yield and species richness and identify areas where efficient trade offs occur between food, carbon, and biodiversity - three critical ecosystem goods and services provided by the world's largest tropical forest.

  5. Adolescents Exiting Homelessness over Two Years: The Risk Amplification and Abatement Model

    ERIC Educational Resources Information Center

    Milburn, Norweeta G.; Rice, Eric; Rotheram-Borus, Mary Jane; Mallett, Shelley; Rosenthal, Doreen; Batterham, Phillip; May, Susanne J.; Witkin, Andrea; Duan, Naihua

    2009-01-01

    The Risk Amplification and Abatement Model (RAAM) demonstrates that negative contact with socializing agents amplify risk, while positive contact abates risk for homeless adolescents. To test this model, the likelihood of exiting homelessness and returning to familial housing at 2 years and stably exiting over time are examined with longitudinal…

  6. 41 CFR 102-80.20 - What are Federal agencies' responsibilities concerning the abatement of radon?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... agencies' responsibilities concerning the abatement of radon? 102-80.20 Section 102-80.20 Public Contracts... REGULATION REAL PROPERTY 80-SAFETY AND ENVIRONMENTAL MANAGEMENT Safety and Environmental Management Radon § 102-80.20 What are Federal agencies' responsibilities concerning the abatement of radon?...

  7. 41 CFR 102-80.20 - What are Federal agencies' responsibilities concerning the abatement of radon?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... agencies' responsibilities concerning the abatement of radon? 102-80.20 Section 102-80.20 Public Contracts... REGULATION REAL PROPERTY 80-SAFETY AND ENVIRONMENTAL MANAGEMENT Safety and Environmental Management Radon § 102-80.20 What are Federal agencies' responsibilities concerning the abatement of radon?...

  8. 30 CFR 75.401 - Abatement of dust; water or water with a wetting agent.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Abatement of dust; water or water with a wetting agent. 75.401 Section 75.401 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Combustible Materials and Rock Dusting § 75.401 Abatement...

  9. 29 CFR 4208.9 - Plan adoption of additional abatement conditions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 9 2013-07-01 2013-07-01 false Plan adoption of additional abatement conditions. 4208.9... Plan adoption of additional abatement conditions. (a) General rule. A plan may by amendment, subject to... actuarial valuation report of the plan. (5) A statement certifying that notice of the adoption of...

  10. 29 CFR 4208.9 - Plan adoption of additional abatement conditions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Plan adoption of additional abatement conditions. 4208.9... Plan adoption of additional abatement conditions. (a) General rule. A plan may by amendment, subject to... actuarial valuation report of the plan. (5) A statement certifying that notice of the adoption of...

  11. 29 CFR 4208.9 - Plan adoption of additional abatement conditions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 9 2012-07-01 2012-07-01 false Plan adoption of additional abatement conditions. 4208.9... Plan adoption of additional abatement conditions. (a) General rule. A plan may by amendment, subject to... actuarial valuation report of the plan. (5) A statement certifying that notice of the adoption of...

  12. 29 CFR 4208.9 - Plan adoption of additional abatement conditions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 9 2011-07-01 2011-07-01 false Plan adoption of additional abatement conditions. 4208.9... Plan adoption of additional abatement conditions. (a) General rule. A plan may by amendment, subject to... actuarial valuation report of the plan. (5) A statement certifying that notice of the adoption of...

  13. 29 CFR 4208.9 - Plan adoption of additional abatement conditions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 9 2014-07-01 2014-07-01 false Plan adoption of additional abatement conditions. 4208.9... Plan adoption of additional abatement conditions. (a) General rule. A plan may by amendment, subject to... actuarial valuation report of the plan. (5) A statement certifying that notice of the adoption of...

  14. 29 CFR 4207.4 - Withdrawal liability payments during pendency of abatement determination.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... establish an escrow account for, the plan that satisfies the requirements of paragraph (b) of this section... withdrawal liability. An employer that applies for abatement and neither provides a bond/escrow nor pays its withdrawal liability payments remains eligible for abatement. (b) Bond/escrow. The bond or escrow allowed...

  15. 29 CFR 4207.4 - Withdrawal liability payments during pendency of abatement determination.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... establish an escrow account for, the plan that satisfies the requirements of paragraph (b) of this section... withdrawal liability. An employer that applies for abatement and neither provides a bond/escrow nor pays its withdrawal liability payments remains eligible for abatement. (b) Bond/escrow. The bond or escrow allowed...

  16. 29 CFR 4208.5 - Withdrawal liability payments during pendency of abatement determination.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... § 4208.5 Withdrawal liability payments during pendency of abatement determination. (a) Bond/Escrow. An... to, or establish an escrow account for, the plan that satisfies the requirements of paragraph (b) of... second consecutive plan year. An employer that applies for abatement and neither provides a...

  17. 29 CFR 4208.5 - Withdrawal liability payments during pendency of abatement determination.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... § 4208.5 Withdrawal liability payments during pendency of abatement determination. (a) Bond/Escrow. An... to, or establish an escrow account for, the plan that satisfies the requirements of paragraph (b) of... second consecutive plan year. An employer that applies for abatement and neither provides a...

  18. URBAN SOIL LEAD ABATEMENT DEMONSTRATION PROJECT: VOLUME I, U.S. EPA INTEGRATED REPORT

    EPA Science Inventory

    The Urban Soil Lead Abatement Demonstration Project (USLADP), known also as the A Three City Lead Study,was authorized in 1986 under Section 111(b)(6) of the Superfund Amendments and Reauthorization Act (SARA), which mandated that EPA conduct soil lead abatement projects in up to...

  19. Asbestos concentrations two years after abatement in seventeen schools. Final summary report

    SciTech Connect

    Kominsky, J.R.; Freyberg, R.W.; Brownlee, J.A.; Gerber, D.R.

    1992-03-01

    Airborne asbestos concentrations were measured at 17 schools that underwent an asbestos abatement 2 years before in 1988. These 17 schools, which involved 20 abatement sites, were part of a study conducted by the U.S. Environmental Protection Agency (EPA) and the New Jersey Department of Health (NJDOH) in 1988. The 1988 study showed that asbestos concentrations measured independently by the NJDOH and EPA during the clearance phase of the abatement were elevated in the abatement and perimeter areas compared with outdoor concentrations. The present study was conducted to determine the current levels of airborne asbestos under simulated occupancy conditions and to determine whether the elevated levels found during the clearance phase were still present 2 years after abatement. In 1990, four sites showed significantly higher mean asbestos concentrations inside the building (i.e., the previously abated area and/or perimeter area) compared with those outdoors (p<0.05). In 1990, the mean asbestos concentration measured in the perimeter area at one site and in the previously abated area at two sites were significantly higher than those in 1988 (p<0.05). Variations in asbestos levels between 1988 and 1990 may be due to sampling techniques (passive and aggressive versus modified aggressive), residual air-entrainable asbestos from the 1988 abatement, or air-entrainable asbestos from operations and maintenance activities since 1988.

  20. Sub-Seafloor Carbon Dioxide Storage Potential on the Juan de Fuca Plate, Western North America

    SciTech Connect

    Jerry Fairley; Robert Podgorney

    2012-11-01

    The Juan de Fuca plate, off the western coast of North America, has been suggested as a site for geological sequestration of waste carbon dioxide because of its many attractive characteristics (high permeability, large storage capacity, reactive rock types). Here we model CO2 injection into fractured basalts comprising the upper several hundred meters of the sub-seafloor basalt reservoir, overlain with low-permeability sediments and a large saline water column, to examine the feasibility of this reservoir for CO2 storage. Our simulations indicate that the sub-seafloor basalts of the Juan de Fuca plate may be an excellent CO2 storage candidate, as multiple trapping mechanisms (hydrodynamic, density inversions, and mineralization) act to keep the CO2 isolated from terrestrial environments. Questions remain about the lateral extent and connectivity of the high permeability basalts; however, the lack of wells or boreholes and thick sediment cover maximize storage potential while minimizing potential leakage pathways. Although promising, more study is needed to determine the economic viability of this option.

  1. The streaming potential of liquid carbon dioxide in BreaSandstone

    SciTech Connect

    Moore, J.; Glaser, S.; Morrison, F.; Hoversten, G.M.

    2004-10-01

    We report here, for the first time, evolution of the streaming potential coupling coefficient as liquid carbon dioxide infiltrates Berea sandstone. Using 125 Omega-m tap water, the coupling coefficient determined before and after each CO2 flood of five samples averaged approximately -30 mV/0.1 MPa. After liquid CO2 passed through the specimens displacing all mobile pore water, trapped water remained and the coupling coefficient was approximately -3 mV/0.1 MPa. A bound water limit of the coupling coefficient for liquid CO2 flow was found using an air-dried sample to be -0.02 mV/0.1 MPa. For initially water-saturated samples, bulk resistivity varied during CO2 invasion from 330 Ohm-m, to 150 Ohm-m during CO2/water mixing, to a final value of 380 Ohm-m. Results suggest that trapped and bound water control electrical conduction and the electrokinetic response. Applications include monitoring CO2 injectate in subsurface reservoirs using the self potential method.

  2. Co-composting solid biowastes with alkaline materials to enhance carbon stabilization and revegetation potential.

    PubMed

    Chowdhury, Saikat; Bolan, Nanthi S; Seshadri, Balaji; Kunhikrishnan, Anitha; Wijesekara, Hasintha; Xu, Yilu; Yang, Jianjun; Kim, Geon-Ha; Sparks, Donald; Rumpel, Cornelia

    2016-04-01

    Co-composting biowastes such as manures and biosolids can be used to stabilize carbon (C) without impacting the quality of these biowastes. This study investigated the effect of co-composting biowastes with alkaline materials on C stabilization and monitored the fertilization and revegetation values of these co-composts. The stabilization of C in biowastes (poultry manure and biosolids) was examined by their composting in the presence of various alkaline amendments (lime, fluidized bed boiler ash, flue gas desulphurization gypsum, and red mud) for 6 months in a controlled environment. The effects of co-composting on the biowastes' properties were assessed for different physical C fractions, microbial biomass C, priming effect, potentially mineralizable nitrogen, bioavailable phosphorus, and revegetation of an urban landfill soil. Co-composting biowastes with alkaline materials increased C stabilization, attributed to interaction with alkaline materials, thereby protecting it from microbial decomposition. The co-composted biowastes also increased the fertility of the landfill soil, thereby enhancing its revegetation potential. Stabilization of biowastes using alkaline materials through co-composting maintains their fertilization value in terms of improving plant growth. The co-composted biowastes also contribute to long-term soil C sequestration and reduction of bioavailability of heavy metals. PMID:26381784

  3. Early evaluation of potential environmental impacts of carbon nanotube synthesis by chemical vapor deposition.

    PubMed

    Plata, Desirée L; Hart, A John; Reddy, Christopher M; Gschwend, Philip M

    2009-11-01

    The carbon nanotube (CNT) industry is expanding rapidly, yet little is known about the potential environmental impacts of CNT manufacture. Here, we evaluate the effluent composition of a representative multiwalled CNT synthesis by catalytic chemical vapor deposition (CVD) in order to provide data needed to design strategies for mitigating any unacceptable emissions. During thermal pretreatment of the reactant gases (ethene and H(2)), we found over 45 side-products were formed, including methane, volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). This finding suggests several environmental concerns with the existing process, including potential discharges of the potent greenhouse gas, methane (up to 1.7%), and toxic compounds such as benzene and 1,3-butadiene (up to 36000 ppmv). Extrapolating these laboratory-scale data to future industrial CNT production, we estimate that (1) contributions of atmospheric methane will be negligible compared to other existing sources and (2) VOC and PAH emissions may become important on local scales but will be small when compared to national industrial sources. As a first step toward reducing such unwanted emissions, we used continuous in situ measures of CNT length during growth and sought to identify which thermally generated compounds correlated with CNT growth rate. The results suggested that, in future CNT production approaches, key reaction intermediates could be delivered to the catalyst without thermal treatment. This would eliminate the most energetically expensive component of CVD synthesis (heating reactant gases), while reducing the formation of unintended byproducts. PMID:19924971

  4. An investigation of some sterically hindered amines as potential carbon dioxide scrubbing compounds

    SciTech Connect

    Hook, R.J.

    1997-05-01

    In order to improve the efficiency of the carbon dioxide cycling process and to reduce amine emissions, a series of nonvolatile amino acid salts with sterically hindered amine groups were investigated to determine their potential as direct replacements for monoethanolamine (MEA) in submarine-based CO{sub 2} scrubbers. Absorption from atmospheres containing various levels of CO{sub 2} was measured to assess the total capacities and absorption rates of amine solutions. The regeneration rates and extent of CO{sub 2} desorption were established by heating these solutions. {sup 13}C NMR spectroscopy was used to establish reaction products and solution compositions after both absorption and desorption. Methyl groups substituted adjacent to the amine were found to increase solution absorption capacities but with an overall reduction in absorption rate. Poor absorption rates at low CO{sub 2} levels and precipitation problems would prevent the {alpha}-dimethylamines examined from being used in existing submarine scrubbers. These amines, however, show potential as replacements in industrial CO{sub 2} scrubbing processes.

  5. LIFE CLIMATREE project: A novel approach for accounting and monitoring carbon sequestration of tree crops and their potential as carbon sink areas

    NASA Astrophysics Data System (ADS)

    Stergiou, John; Tagaris, Efthimios; -Eleni Sotiropoulou, Rafaella

    2016-04-01

    Climate Change Mitigation is one of the most important objectives of the Kyoto Convention, and is mostly oriented towards reducing GHG emissions. However, carbon sink is retained only in the calculation of the forests capacity since agricultural land and farmers practices for securing carbon stored in soils have not been recognized in GHG accounting, possibly resulting in incorrect estimations of the carbon dioxide balance in the atmosphere. The agricultural sector, which is a key sector in the EU, presents a consistent strategic framework since 1954, in the form of Common Agricultural Policy (CAP). In its latest reform of 2013 (reg. (EU) 1305/13) CAP recognized the significance of Agriculture as a key player in Climate Change policy. In order to fill this gap the "LIFE ClimaTree" project has recently founded by the European Commission aiming to provide a novel method for including tree crop cultivations in the LULUCF's accounting rules for GHG emissions and removal. In the framework of "LIFE ClimaTree" project estimation of carbon sink within EU through the inclusion of the calculated tree crop capacity will be assessed for both current and future climatic conditions by 2050s using the GISS-WRF modeling system in a very fine scale (i.e., 9km x 9km) using RCP8.5 and RCP4.5 climate scenarios. Acknowledgement: LIFE CLIMATREE project "A novel approach for accounting and monitoring carbon sequestration of tree crops and their potential as carbon sink areas" (LIFE14 CCM/GR/000635).

  6. Inorganic carbon acquisition in potentially toxic and non-toxic diatoms: the effect of pH-induced changes in seawater carbonate chemistry.

    PubMed

    Trimborn, Scarlett; Lundholm, Nina; Thoms, Silke; Richter, Klaus-Uwe; Krock, Bernd; Hansen, Per Juel; Rost, Björn

    2008-05-01

    The effects of pH-induced changes in seawater carbonate chemistry on inorganic carbon (C(i)) acquisition and domoic acid (DA) production were studied in two potentially toxic diatom species, Pseudo-nitzschia multiseries and Nitzschia navis-varingica, and the non-toxic Stellarima stellaris. In vivo activities of carbonic anhydrase (CA), photosynthetic O(2) evolution and CO(2) and HCO(3)(-) uptake rates were measured by membrane inlet MS in cells acclimated to low (7.9) and high pH (8.4 or 8.9). Species-specific differences in the mode of carbon acquisition were found. While extracellular carbonic anhydrase (eCA) activities increased with pH in P. multiseries and S. stellaris, N. navis-varingica exhibited low eCA activities independent of pH. Half-saturation concentrations (K(1/2)) for photosynthetic O(2) evolution, which were highest in S. stellaris and lowest in P. multiseries, generally decreased with increasing pH. In terms of carbon source, all species took up both CO(2) and HCO(3)(-). K(1/2) values for inorganic carbon uptake decreased with increasing pH in two species, while in N. navis-varingica apparent affinities did not change. While the contribution of HCO(3)(-) to net fixation was more than 85% in S. stellaris, it was about 55% in P. multiseries and only approximately 30% in N. navis-varingica. The intracellular content of DA increased in P. multiseries and N. navis-varingica with increasing pH. Based on our data, we propose a novel role for eCA acting as C(i)-recycling mechanism. With regard to pH-dependence of growth, the 'HCO(3)(-) user' S. stellaris was as sensitive as the 'CO(2) user' N. navis-varingica. The suggested relationship between DA and carbon acquisition/C(i) limitation could not be confirmed. PMID:18405335

  7. Novel hexacyanoferrate (III)-modified carbon electrodes: application in miniaturized biosensors with potential for in vivo glucose sensing.

    PubMed

    Jaffari, S A; Pickup, J C

    1996-01-01

    We adapted a new technology for the modification of carbon base electrodes for use as probe-type, potentially implantable glucose sensors. Carbon rods (diameter 0.3 mm) were modified by repeated potential cycling in 0.1 M potassium hexacyanoferrate (III). The modified-carbon electrodes were sealed in plastic pipette tips with an exposed reaction area where glucose oxidase was immobilized using glutaraldehyde. An outer membrane of Nafion, followed by 15% (w/v) polyurethane, was applied over the enzyme layer. The miniature modified-carbon glucose sensors displayed a sensitivity to glucose in phosphate-buffered saline of 91.4 +/- 19 nA/mM (mean +/- SEM) and a linear range up to 5.3 +/- 1 mM glucose when operated at 750 mV versus a silver/silver chloride reference. Corresponding, unmodified-carbon based glucose sensors displayed a lower sensitivity of 20.7 +/- 3 nA/mM with a linear range up to 3.8 +/- 0.5 mM. The modified-carbon glucose sensors responded to glucose when operated in plasma but with a reduced sensitivity compared with that in buffered saline. Glucose sensors displayed good stability for up to 6.5 days during continuous operation in 5 mM buffered glucose solution. Interference from ascorbate and 4-acetamidophenol at both physiological and pharmacological ranges was significantly lower at the modified-carbon base electrodes than that at the unmodified-carbon base electrodes. Also, the relatively large effect of ascorbate and 4-acetamidophenol at the unmodified-carbon base electrode was reduced considerably when the base electrode was coated with glucose oxidase, Nafion and polyurethane membranes. PMID:8828167

  8. Degradation State and Sequestration Potential of Carbon in Coastal Wetlands of Texas: Mangrove Vs. Saltmarsh Ecosystems

    NASA Astrophysics Data System (ADS)

    Sterne, A. M. E.; Kaiser, K.; Louchouarn, P.; Norwood, M. J.

    2015-12-01

    The estimated magnitude of the organic carbon (OC) stocks contained in the first meter of US coastal wetland soils represents ~10% of the entire OC stock in US soils (4 vs. 52 Pg, respectively). Because this stock extends to several meters below the surface for many coastal wetlands, it becomes paramount to understand the fate of OC under ecosystem shifts, varying natural environmental constraints, and changing land use. In this project we analyze the major classes of biochemicals including total hydrolysable neutral carbohydrates, enantiomeric amino acids, phenols, and cutins/suberins at two study sites located on the Texas coastline to investigate chemical composition and its controls on organic carbon preservation in mangrove (Avicennia germinans) and saltmarsh grass (Spartina alterniflora) dominated wetlands. Results show neutral carbohydrates and lignin contribute 30-70% and 10-40% of total OC, respectively, in plant litter and surface sediments at both sites. Sharp declines of carbohydrate yields with depth occur parallel to increasing Ac/AlS,V ratios indicating substantial decomposition of both the polysaccharide and lignin components of litter detritus. Contrasts in the compositions and relative abundances of all previously mentioned compound classes are further discussed to examine the role of litter biochemistry in OC preservation. For example, the selective preservation of cellulose over hemicellulose in sediments indicates macromolecular structure plays a key role in preservation between plant types. It is concluded that the chemical composition of litter material controls the composition and magnitude of OC stored in sediments. Ultimately, as these ecosystems transition from one dominant plant type to another, as is currently observed along the Texas coastline, there is the potential for OC sequestration efficiency to shift due to the changing composition of OC input to sediments.

  9. Potential flue gas impurities in carbon dioxide streams separated from coal-fired power plants

    SciTech Connect

    Joo-Youp Lee; Tim C. Keener; Y. Jeffery Yang

    2009-06-15

    This study estimated the flue gas impurities to be included in the CO{sub 2} stream separated from a CO{sub 2} control unit for a different combination of air pollution control devices and different flue gas compositions. Specifically, the levels of acid gases and mercury vapor were estimated for the monoethanolamine (MEA)-based absorption process on the basis of published performance parameters of existing systems. Among the flue gas constituents considered, sulfur dioxide (SO{sub 2}) is known to have the most adverse impact on MEA absorption. When a flue gas contains 3000 parts per million by volume (ppmv) SO{sub 2} and a wet flue gas desulfurization system achieves its 95% removal, approximately 2400 parts per million by weight (ppmw) SO{sub 2} could be included in the separated CO{sub 2} stream. In addition, the estimated concentration level was reduced to as low as 135 ppmw for the SO{sub 2} of less than 10 ppmv in the flue gas entering the MEA unit. Furthermore, heat-stable salt formation could further reduce the SO{sub 2} concentration below 40 ppmw in the separated CO{sub 2} stream. In this study, it is realized that the formation rates of heat-stable salts in MEA solution are not readily available in the literature and are critical to estimating the levels and compositions of flue gas impurities in sequestered CO{sub 2} streams. In addition to SO{sub 2}, mercury, and other impurities in separated CO{sub 2} streams could vary depending on pollutant removal at the power plants and impose potential impacts on groundwater. Such a variation and related process control in the upstream management of carbon separation have implications for groundwater protection at carbon sequestration sites and warrant necessary considerations in overall sequestration planning, engineering, and management. 63 refs., 1 fig., 3 tabs.

  10. Potential and cost of carbon sequestration in the Tanzanian forest sector

    SciTech Connect

    Makundi, Willy R.

    2001-01-01

    The forest sector in Tanzania offers ample opportunities to reduce greenhouse gas emissions (GHG) and sequestered carbon (C) in terrestrial ecosystems. More than 90% of the country's demand for primary energy is obtained from biomass mostly procured unsustainably from natural forests. This study examines the potential to sequester C through expansion of forest plantations aimed at reducing the dependence on natural forest for wood fuel production, as well as increase the country's output of industrial wood from plantations. These were compared ton conservation options in the tropical and miombo ecosystems. Three sequestration options were analyzed, involving the establishment of short rotation and long rotation plantations on about 1.7 x 106 hectares. The short rotation community forest option has a potential to sequester an equilibrium amount of 197.4 x 106 Mg C by 2024 at a net benefit of $79.5 x 106, while yielding a NPV of $0.46 Mg-1 C. The long rotation options for softwood and hardwood plantations will reach an equilibrium sequestration of 5.6 and 11.8 x 106 Mg C at a negative NPV of $0.60 Mg-1 C and $0.32 Mg-1 C. The three options provide cost competitive opportunities for sequestering about 7.5 x 106 Mg C yr -1 while providing desired forest products and easing the pressure on the natural forests in Tanzania. The endowment costs of the sequestration options were all found to be cheaper than the emission avoidance cost for conservation options which had an average cost of $1.27 Mg-1 C, rising to $ 7.5 Mg-1 C under some assumptions on vulnerability to encroachment. The estimates shown here may represent the upper bound, because the actual potential will be influenced by market prices for inputs and forest products, land use policy constraints and the structure of global C transactions.

  11. Chlordecone potentiates hepatic fibrosis in chronic liver injury induced by carbon tetrachloride in mice.

    PubMed

    Tabet, Elise; Genet, Valentine; Tiaho, François; Lucas-Clerc, Catherine; Gelu-Simeon, Moana; Piquet-Pellorce, Claire; Samson, Michel

    2016-07-25

    Chronic liver damage due to viral or chemical agents leads to a repair process resulting in hepatic fibrosis. Fibrosis may lead to cirrhosis, which may progress to liver cancer or a loss of liver function, with an associated risk of liver failure and death. Chlordecone is a chlorinated pesticide used in the 1990s. It is not itself hepatotoxic, but its metabolism in the liver triggers hepatomegaly and potentiates hepatotoxic agents. Chlordecone is now banned, but it persists in soil and water, resulting in an ongoing public health problem in the Caribbean area. We assessed the probable impact of chlordecone on the progression of liver fibrosis in the population of contaminated areas, by developing a mouse model of chronic co-exposure to chlordecone and a hepatotoxic agent, carbon tetrachloride (CCl4). After repeated administrations of chlordecone and CCl4 by gavage over a 12-week period, we checked for liver damage in the exposed mice, by determining serum liver transaminase (AST, ALT) levels, histological examinations of the liver and measuring the expression of genes encoding extracellular matrix components. The co-exposure of mice to CCl4 and chlordecone resulted in significant increases in ALT and AST levels. Chlordecone also increased expression of the Col1A2, MMP-2, TIMP-1 and PAI-1 genes in CCl4-treated mice. Finally, we demonstrated, by quantifying areas of collagen deposition and alpha-SMA gene expression, that chlordecone potentiated the hepatic fibrosis induced by CCl4. In conclusion, our data suggest that chlordecone potentiates hepatic fibrosis in mice with CCl4-induced chronic liver injury. PMID:26853152

  12. Carbon monoxide effects on human ventricle action potential assessed by mathematical simulations

    PubMed Central

    Trenor, Beatriz; Cardona, Karen; Saiz, Javier; Rajamani, Sridharan; Belardinelli, Luiz; Giles, Wayne R.

    2013-01-01

    Carbon monoxide (CO) that is produced in a number of different mammalian tissues is now known to have significant effects on the cardiovascular system. These include: (i) vasodilation, (ii) changes in heart rate and strength of contractions, and (iii) modulation of autonomic nervous system input to both the primary pacemaker and the working myocardium. Excessive CO in the environment is toxic and can initiate or mediate life threatening cardiac rhythm disturbances. Recent reports link these ventricular arrhythmias to an increase in the slowly inactivating, or “late” component of the Na+ current in the mammalian heart. The main goal of this paper is to explore the basis of this pro-arrhythmic capability of CO by incorporating changes in CO-induced ion channel activity with intracellular signaling pathways in the mammalian heart. To do this, a quite well-documented mathematical model of the action potential and intracellular calcium transient in the human ventricular myocyte has been employed. In silico iterations based on this model provide a useful first step in illustrating the cellular electrophysiological consequences of CO that have been reported from mammalian heart experiments. Specifically, when the Grandi et al. model of the human ventricular action potential is utilized, and after the Na+ and Ca2+ currents in a single myocyte are modified based on the experimental literature, early after-depolarization (EAD) rhythm disturbances appear, and important elements of the underlying causes of these EADs are revealed/illustrated. Our modified mathematical model of the human ventricular action potential also provides a convenient digital platform for designing future experimental work and relating these changes in cellular cardiac electrophysiology to emerging clinical and epidemiological data on CO toxicity. PMID:24146650

  13. Fluxes of nitrous oxide and carbon dioxide over four potential biofuel crops in Central Illinois

    NASA Astrophysics Data System (ADS)

    Zeri, M.; Hickman, G. C.; Bernacchi, C.

    2009-12-01

    Nitrous oxide (N2O) and carbon dioxide (CO2) are important greenhouse gases that contribute to global climate change. Agriculture is a significant source of N2O to the atmosphere due to the use of nitrogen-based fertilizers. Fluxes of N2O and CO2 are measured using the flux-gradient technique over four different crops at the Energy Farm, a University of Illinois research facility in Urbana, Illinois. Measurements started in June of 2009 and are part of a project that aims to assess the impacts of potential biofuel crops on the carbon, water and nitrogen cycles. The species chosen are Maize (Zea mays), Miscanthus (Miscanthus x giganteus), Switchgrass (Panicum virgatum) and Prairie (a mix of several native species). The choice of species was based on their potential for the production of second-generation biofuels, i.e., fuels derived from the decomposition of the cellulosic material in the plant biomass. The use of corn residue for cellulosic biofuels might impact the carbon cycle through the reduction of soil organic content. Miscanthus is a perennial grass with great potential for biomass production. However, the total water used during the growing season and its water use efficiency might impose limits on the regions where this biofuel crop can be sustainably planted on a large scale. Switchgrass and the prairie species are less productive but might be suited for being well adapted and easy to establish. This study is the first side-by-side comparison of fluxes of N2O for these agro-ecosystems. The measurements are performed at micrometeorological towers placed at the center of 4 ha plots. The air is sampled at two heights over the vegetation and is analyzed in a tunable diode laser (TDL) installed nearby. A valve system cycles the TDL measurements trough all the intakes in the plots. The fluxes are calculated using the flux-gradient method, which requires the knowledge of the scalar vertical gradient as well as of the friction velocity (u*) and the Monin

  14. The Streaming Potential Coupling Coefficient of Liquid Carbon Dioxide Injected Into Water Saturated Berea Sandstone

    NASA Astrophysics Data System (ADS)

    Moore, J. R.; Glaser, S. D.; Morrison, H. F.

    2003-12-01

    The streaming potential coupling coefficient was determined for a liquid carbon dioxide flood of a water-saturated sample of Berea sandstone. The coupling coefficient for the rock/water case was determined both before and after each CO2 flood of three samples using a low-pressure static head method. Next, liquid CO2 was allowed to flow through each sample. As the CO2 displaced the water the coupling coefficient decreased. At longer times, when all mobile pore water was displaced, the coupling coefficient maintained a steady state, and was lower than that for water by about 10 times. The results of this testing reveal a coupling coefficient of 30 mV/0.1MPa, for 125 Ohm-m water flow through the sample, and 3.0 mV / 0.1 MPa for liquid CO2 flow. Calculated zeta potentials are -3.4 mV using water as the pore fluid and -1.7 x 10-6 mV for liquid CO2. We propose that the lower coupling coefficient for CO2 flow is primarily a result of changes in zeta potential, since changes in pore fluid resistivity and viscosity would act to increase the coupling coefficient. Zeta potential for the liquid CO2 / mineral interface is a function of the low polarity and lack of mobile ions associated with liquid CO2. We find no anomalous 2-phase liquid/gas effects, which may have augmented single-phase streaming potentials by many times. We propose that although CO2 gas may have been present for some of the higher pressure drop events, the low gas fraction (or quality) of the two-phase mixture did not lead to any significant anomalous or augmented observations. Implications of this work include spatial and temporal monitoring of CO2 injectate in subsurface reservoirs and the identification of flow paths, with the recommendation being to attempt to image the advancing CO2/water front, where the coupling coefficient is higher.

  15. Transport Sector Marginal Abatement Cost Curves in Computable General Equilibrium Model

    NASA Astrophysics Data System (ADS)

    Tippichai, Atit; Fukuda, Atsushi; Morisugi, Hisayoshi

    In the last decade, computable general equilibrium (CGE) models have emerged a standard tool for climate policy evaluation due to their abilities to prospectively elucidate the character and magnitude of the economic impacts of energy and environmental policies. Furthermore, marginal abatement cost (MAC) curves which represent GHG emissions reduction potentials and costs can be derived from these top-down economic models. However, most studies have never address MAC curves for a specific sector that have a large coverage of countries which are needed for allocation of optimal emission reductions. This paper aims to explicitly describe the meaning and character of MAC curves for transport sector in a CGE context through using the AIM/CGE Model developed by Toshihiko Masui. It found that the MAC curves derived in this study are the inverse of the general equilibrium reduction function for CO2 emissions. Moreover, the transport sector MAC curves for six regions including USA, EU-15, Japan, China, India, and Brazil, derived from this study are compared to the reduction potentials under 100 USD/tCO2 in 2020 from a bottom-up study. The results showed that the ranking of the regional reduction potentials in transport sector from this study are almost same with the bottom-up study except the ranks of the EU-15 and China. In addition, the range of the reduction potentials from this study is wider and only the USA has higher potentials than those derived from the bottom-up study.

  16. Geophysical numerical modeling approach for characterizing and monitoring potential carbon sequestration injection sites

    NASA Astrophysics Data System (ADS)

    Shalek, Kyle James

    Geological sequestration has been proposed as a viable option for mitigating the vast amount of CO2 being released into the atmosphere daily. Test sites for CO2 injection have been appearing across the world to ascertain the feasibility of capturing and sequestering carbon dioxide. A major concern with full scale implementation is monitoring and verifying the permanence of injected CO2. Geophysical methods, an exploration industry standard, are non-invasive imaging techniques that can be implemented to address that concern. Geophysical methods, seismic and electromagnetic, play a crucial role in monitoring the subsurface pre- and post-injection. Seismic techniques have been the most popular but electromagnetic methods are gaining interest. The primary goal of this project was to develop a new geophysical tool, a software program called GphyzCO2, to investigate the implementation of geophysical monitoring for detecting injected CO2 at test sites. The GphyzCO2 software consists of interconnected programs that encompass well logging, seismic, and electromagnetic methods. The software enables users to design and execute 3D surface-to-surface (conventional surface seismic) and borehole-to-borehole (cross-hole seismic and electromagnetic methods) numerical modeling surveys. The generalized flow of the program begins with building a complex 3D subsurface geological model, assigning properties to the models that mimic a potential CO2 injection site, numerically forward model a geophysical survey, and analyze the results. A test site located in Warren County, Ohio was selected as the test site for the full implementation of GphyzCO2. Specific interest was placed on a potential reservoir target, the Mount Simon Sandstone, and cap rock, the Eau Claire Formation. Analysis of the test site included well log data, physical property measurements (porosity), core sample resistivity measurements, calculating electrical permittivity values, seismic data collection, and seismic

  17. Regional and sectoral marginal abatement cost curves for NOx incorporating controls, renewable electricity, energy efficiency and fuel switching

    EPA Science Inventory

    A marginal abatement cost curve (MACC) traces out the relationship between the quantity of pollution abated and the marginal cost of abating each additional unit. In the context of air quality management, MACCs typically are developed by sorting end-of-pipe controls by their resp...

  18. Vibration analysis of single-walled carbon nanocones using multiscale atomistic finite element method incorporating Tersoff-Brenner potential

    NASA Astrophysics Data System (ADS)

    Gajbhiye, Sachin O.; Singh, S. P.

    2015-07-01

    This research work addresses the free and forced vibration characteristics of single-walled carbon nanocones (SWCNCs) using multiscale atomistic finite element method (AFEM) incorporating Tersoff-Brenner (TB) potential. The multibody interatomic TB potential is used to represent the energy between two carbon atoms. Based on the TB potential, new set of force constant parameters is established for carbon nanocones, and the equivalent geometric and elastic properties of the space frame element to represent carbon-carbon bond are derived which are consistent with the material constitutive relations. The eigenvalues of clamped and cantilevered SWCNCs with different disclination angles are extracted using AFEM, and the effect of these angles on the resonant frequencies is investigated. A computational sine sweep test is carried out on the atomic structure of SWCNCs within the frequency range of 0-10 THz to investigate the steady-state forced vibration response under harmonic excitation. The frequency response of the SWCNCs to the cyclic and impulse load over an applied frequency range is calculated. Based on the forced vibration response spectra, the resonant frequency components of SWCNCs are identified. The results have been validated using molecular dynamics simulation.

  19. Carbon emissions reduction potential in the US chemicals and pulp and paper industries by applying CHP technologies

    SciTech Connect

    Khrushch, M.; Worrell, E.; Price, L.; Martin, N.; Einstein, D.

    1999-07-01

    The chemical and the pulp/paper industries combined provide 55% of CHP generation in the US industry. Yet, significant potential for new CHP capacities exists in both industries. From the present steam consumption data, the authors estimate about 50 GW of additional technical potential for CHP in both industries. The reduced carbon emissions will be equivalent to 44% of the present carbon emissions in these industries. They find that most of the carbon emissions reductions can be achieved at negative costs. Depending on the assumptions used in calculations, the economic potential of CHP in these industries can be significantly lower, and carbon emissions mitigation costs can be much higher. Using sensitivity analyses, they determine that the largest effect on the CHP estimate have the assumptions in the costs of CHP technology, in the assumed discount rates, in improvements in efficiency of CHP technologies, and in the CHP equipment depreciation periods. Changes in fuel and electricity prices and the growth in the industries' steam demand have less of an effect. They conclude that the lowest carbon mitigation costs are achieved with the CHP facility is operated by the utility and when industrial company that owns the CHP unit can sell extra electricity and steam to the open wholesale market. Based on the results of the analyses they discuss policy implications.

  20. Assessing Actual and Potential Organic Carbon Pools in Southern Taiga and Forest-Steppe Ecosystems of Russia

    NASA Astrophysics Data System (ADS)

    Chernova, Olga; Ryzhova, Irina; Podvezennaya, Marina

    2014-05-01

    Recent debates on climate changes showed the importance of maintaining natural cycles of nutrients and preserving extensive areas of natural ecosystems to ensure sustainability of the biosphere. The size and distribution of nutrient pools within ecosystems are the key characteristics of the biological cycle reflecting changes in the functioning of natural systems. Carbon pools assessed in similar land-use types by different researchers are often poorly comparable due to various calculation algorithms, sampling techniques and sets of field data used. Model-based assessments often yield results that significantly depart from calculations based on actual field data. We estimated the actual and potential natural carbon pools using potential natural vegetation maps, soil maps, up-to-date statistics and results of regional studies. Organic carbon pools in biomass, forest litter, peat and soil were calculated for most typical natural (ecosystems, which experienced the least effect of historic land use) and modern ecosystems for two administrative regions of Russia: 1. Kursk region characterized by high productive natural steppe vegetation with predominance of chernozems - the country's most fertile soils, which were extensively transformed by agricultural activity; 2. Kostroma region, sparsely populated area with still abundant southern taiga forests. The average characteristics of vegetation productivity for natural and some human-modified ecosystems such as coniferous (pine, spruce) and noble broadleaf (oak, linden) forests, swamps, bogs, steppes, bottomland meadows, secondary forests, hayfields, pastures were calculated using the Database on the Productivity of Ecosystems in North Eurasia. The biological productivity of present-day forests and carbon pools in biomass were calculated using the program for assessing forest carbon budget (ROBUL model). Similar characteristics were used for agricultural areas. They were averaged according to crop rotations and recalculated

  1. Potential near-future carbon uptake overcomes losses from a large insect outbreak in British Columbia, Canada

    NASA Astrophysics Data System (ADS)

    Arora, Vivek K.; Peng, Yiran; Kurz, Werner A.; Fyfe, John C.; Hawkins, Barbara; Werner, Arelia T.

    2016-03-01

    The current capacity of northern high-latitude forests to sequester carbon has been suggested to be undermined by the potential increase in fire and insect outbreaks. Here we investigate the response of the terrestrial ecosystems in the province of British Columbia (BC), Canada, to the recent large mountain pine beetle (MPB) outbreak that started in 1999 as well as changing climate and continually increasing atmospheric CO2 concentration up to 2050, in a combined framework, using a process-based model. Model simulations suggest that the recent MPB outbreak results in BC's forests accumulating 328 Tg less carbon over the 1999-2020 period. Over this same period changing climate and increasing atmospheric CO2 concentration, however, yield enhanced carbon uptake equal to a cumulative sink of around 900-1060 Tg C, depending on the future climate change scenario, indicating that the reduced carbon uptake by land due to the MPB disturbance may already be surpassed by 2020.

  2. SMA Hybrid Composites for Dynamic Response Abatement Applications

    NASA Technical Reports Server (NTRS)

    Turner, Travis L.

    2000-01-01

    A recently developed constitutive model and a finite element formulation for predicting the thermomechanical response of Shape Memory Alloy (SMA) hybrid composite (SMAHC) structures is briefly described. Attention is focused on constrained recovery behavior in this study, but the constitutive formulation is also capable of modeling restrained or free recovery. Numerical results are shown for glass/epoxy panel specimens with embedded Nitinol actuators subjected to thermal and acoustic loads. Control of thermal buckling, random response, sonic fatigue, and transmission loss are demonstrated and compared to conventional approaches including addition of conventional composite layers and a constrained layer damping treatment. Embedded SMA actuators are shown to be significantly more effective in dynamic response abatement applications than the conventional approaches and are attractive for combination with other passive and/or active approaches.

  3. Estimating European soil organic carbon mitigation potential in a global integrated land use model

    NASA Astrophysics Data System (ADS)

    Frank, Stefan; Böttcher, Hannes; Schneider, Uwe; Schmid, Erwin; Havlík, Petr

    2013-04-01

    Several studies have shown the dynamic interaction between soil organic carbon (SOC) sequestration rates, soil management decisions and SOC levels. Management practices such as reduced and no-tillage, improved residue management and crop rotations as well as the conversion of marginal cropland to native vegetation or conversion of cultivated land to permanent grassland offer the potential to increase SOC content. Even though dynamic interactions are widely acknowledged in literature, they have not been implemented in most existing land use decision models. A major obstacle is the high data and computing requirements for an explicit representation of alternative land use sequences since a model has to be able to track all different management decision paths. To our knowledge no study accounted so far for SOC dynamics explicitly in a global integrated land use model. To overcome these conceptual difficulties described above we apply an approach capable of accounting for SOC dynamics in GLOBIOM (Global Biosphere Management Model), a global recursive dynamic partial equilibrium bottom-up model integrating the agricultural, bioenergy and forestry sectors. GLOBIOM represents all major land based sectors and therefore is able to account for direct and indirect effects of land use change as well as leakage effects (e.g. through trade) implicitly. Together with the detailed representation of technologies (e.g. tillage and fertilizer management systems), these characteristics make the model a highly valuable tool for assessing European SOC emissions and mitigation potential. Demand and international trade are represented in this version of the model at the level of 27 EU member states and 23 aggregated world regions outside Europe. Changes in the demand on the one side, and profitability of the different land based activities on the other side, are the major determinants of land use change in GLOBIOM. In this paper we estimate SOC emissions from cropland for the EU until

  4. Abatement of SF{sub 6} and CF{sub 4} using an enhanced kerosene microwave plasma burner

    SciTech Connect

    Shin, Dong Hun; Hong, Yong Cheol; Cho, Soon Cheon; Uhm, Han Sup

    2006-11-15

    A kerosene microwave plasma burner was presented as a tool for abatement of SF{sub 6} and CF{sub 4} gases, which cause global warming. The plasma burner operates by injecting kerosene as a liquid hydrocarbon fuel into a microwave plasma torch and by mixing the resultant gaseous hydrogen and carbon compounds with air or oxygen (O{sub 2}) gas. The abatement of SF{sub 6} and CF{sub 4}, by making use of the kerosene plasma burner, was conducted in terms of nitrogen (N{sub 2}) flow rates. The destruction and removal efficiency of the burner were achieved up to 99.9999% for 0.1 liters per minute (lpm) SF{sub 6} in 120 lpm N{sub 2} and 99.3% for 0.05 lpm CF{sub 4} in 60 lpm N{sub 2}, revealing that the microwave plasma burner can effectively eliminate perfluorocompounds emitted from the semiconductor industries.

  5. Trihalomethane, haloacetonitrile, and chloral hydrate formation potentials of organic carbon fractions from sub-tropical forest soils.

    PubMed

    Zhang, Qian; Kuang, Wan-fang; Liu, Lu-ying; Li, Kexin; Wong, Kin-hang; Chow, Alex T; Wong, Po-keung

    2009-12-30

    Forest landscapes represent the major land-cover type for the watersheds of the East River, which is the source of water for 40 million people in South China. Forest soils with high levels of organic carbon are a potential terrestrial source of dissolved organic carbon (DOC) into the East River. DOC is of great concern, since it can form carcinogenic disinfection byproducts (DBPs) during drinking water treatment. In this study, soils from three altitudes (200, 450 and 900 m) in the Xiangtou Mountain Nature Reserve in South China, representing soils from evergreen moon forest, transitional evergreen broadleaf forest, and evergreen broadleaf forest, respectively, were evaluated for their potential contributions of DBP precursors into the East River. The water extractable organic carbon (WEOC) in three forest soils was physically and chemically fractionated into particulate organic carbon (1.2-0.45 microm), colloidal organic carbon (0.45-0.22 microm), and dissolved organic carbon (DOC) (<0.22 microm), hydrophobic acid (HPOA), transphilic acid and hydrophilic acid and were analysed for the formation potentials of trihalomethanes (THMs), haloacetonitriles (HANs), and chloral hydrate (CHD). Also, soils were incubated at 15, 25 and 35 degrees C for 14d in darkness to examine the impact of temperature effects on the availability and characteristics of WEOC. The extraction study showed that the amount of WEOC was proportional to soil organic carbon content, of which about 1% was water extractable. Regardless of soil type, DOC and HPOA were the most reactive fractions in forming THMs, CHD, and HANs. Production of DOC and HPOA in WEOC increased over 14 d incubation as incubation temperature increased, but the temperature did not alter the distribution of physical and chemical fractions and their reactivity in DBP formation. Results suggest higher inputs of DOC and DBP precursors from forest watersheds into source water may result in a warmer environment. PMID:19695772

  6. Intermittent control procedures for the Geysers hydrogen sulfide emission abatement

    SciTech Connect

    Buick, B.D.; Mooney, M.L.

    1984-01-01

    Pacific Gas and Electric Company (PG and E) operates the world's largest geothermal steam electric power generation facility, currently about 1.140 megawatts (Mw). This facility is located about 80 miles north of San Francisco, California and is within a region referred to as the Known Geothermal Resource Area (KGRA). Pollutants resulting from this method of electric power generation are due to impurities in the geothermal steam. A major contaminate in the steam is hydrogen sulfide (H/sub 2/S), a regulated pollutant in California. The ambient air quality standard (AAQS) for this pollutant in California is 0.03 parts per million (ppM) averaged over one hour. H/sub 2/S is an invisible, unpleasant smelling gas present in varying concentrations in the geothermal steam. Its odor has been compared to the smell of rotten eggs. Since PG and E is increasingly relying on this source of electrical power generation, it has committed millions of dollars to the development, testing, acquisition, and installation of abatement equipment to reduce H/sub 2/S emissions during the past ten years. In order to reduce the number of exceeds of the AAQS during this developmental period, a predictive model was needed for interim abatement purposes. Most of the high hourly H/sub 2/S values occur with meteorological conditions having poor ventilation resulting from a combination of low wind speed and reduced mixing layer depths. This weather condition is most common during the months of June through October in California. A predictive model was developed from three years of hourly H/sub 2/S measurements of 0.03 ppM or greater in populated areas downwind of the generation facility and from observations of associated meteorological data.

  7. The microwave assisted synthesis of 1-alkyl-3-methylimidazolium bromide as potential corrosion inhibitor toward carbon steel in 1 M HCl solution saturated with carbon dioxide

    NASA Astrophysics Data System (ADS)

    Pasasa, Norman Vincent A.; Bundjali, Bunbun; Wahyuningrum, Deana

    2015-09-01

    Injection of corrosion inhibitor into the fluid current of oil and gas pipelines is an effective way to mitigate corrosion rate on the inner-surface parts of pipelines, especially carbon steel pipelines. In this research, two alkylimidazolium ionic liquids, 1-decyl-3-methylimidazolium bromide (IL1) and 1-dodecyl-3-methylimidazolium bromide (IL2) have been synthesized and studied as a potential corrosion inhibitor towards carbon steel in 1 M HCl solution saturated with carbon dioxide. IL1 and IL2 were synthesized using microwave assisted organic synthesis (MAOS) method. Mass Spectrometry analysis of IL1 and IL2 showed molecular mass [M-H+] peak at 223.2166 and 251.2484, respectively. The FTIR,1H-NMR and 13C-NMR spectra confirmed that IL1 and IL2 were successfully synthesized. Corrosion inhibition activity of IL1 and IL2 were determined using weight loss method. The results showed that IL1 and IL2 have the potential as good corrosion inhibitors with corrosion inhibition efficiency of IL1 and IL2 are 96.00% at 100 ppm (343 K) and 95.60% at 50 ppm (343 K), respectively. The increase in the concentration of IL1 and IL2 tends to improve their corrosion inhibition activities. Analysis of the data obtained from the weight loss method shows that the adsorption of IL1 and IL2 on carbon steel is classified into chemisorption which obeys Langmuir's adsorption isotherm.

  8. Global Monitoring of Terrestrial Chlorophyll Fluorescence from Space: Status and Potential for Carbon Cycle Research

    NASA Astrophysics Data System (ADS)

    Guanter, L.; Koehler, P.; Walther, S.; Zhang, Y.; Joiner, J.; Frankenberg, C.

    2015-12-01

    Gross primary production (GPP), or the amount of atmospheric CO2 fixed by vegetation through photosynthesis, represents the largest carbon flux between terrestrial ecosystems and the atmosphere. Despite its importance, large-scale estimates of GPP remain highly uncertain for some terrestrial ecosystems. In this context, measurements of sun-induced chlorophyll fluorescence (SIF), which is emitted in the 650-850nm spectral range by the photosynthetic apparatus of green plants, have the potential to provide a new view on vegetation photosynthesis. Global monitoring of SIF from space have been achieved in the last years by means of a number of atmospheric spectrometers, which have turned out to provide the necessary spectral and radiometric sensitivity for SIF retrieval. The first global measurements of SIF were achieved in 2011 from spectra acquired by the Japanese GOSAT mission. This breakthorugh was followed by retrievals from the Global Ozone Monitoring Experiment-2 (GOME-2) instruments onboard MetOp-A and MetOp-B, which enable a continuous spatial sampling, and lately from ENVISAT/SCIAMACHY. This observational scenario is completed by the first SIF data from the NASA-JPL OCO-2 mission (launched in July 2014) and the upcoming Copernicus' Sentinel 5-Precursor to be launched by early 2016. OCO-2 and TROPOMI offer the possibility of monitoring SIF globally with a 100-fold improvement in spatial and temporal resolution with respect to GOSAT, GOME-2 and SCIAMACHY.In this contribution, we will provide an overview of global SIF monitoring and will illustrate the potential of SIF data to improve our knowledge of vegetation photosynthesis and GPP at the synoptic scale. We will show examples of ongoing research exploiting SIF data for an improved monitoring of photosynthetic activity at different ecosystems, highlighting the usefulness of SIF to constrain estimates of CO2 uptake by vegetation through photosynthesis.

  9. Environmental potential of carbon dioxide utilization in the polyurethane supply chain.

    PubMed

    von der Assen, Niklas; Sternberg, André; Kätelhön, Arne; Bardow, André

    2015-01-01

    Potential environmental benefits have been identified for the utilization of carbon dioxide (CO2) as a feedstock for polyurethanes (PUR). CO2 can be utilized in the PUR supply chain in a wide variety of ways ranging from direct CO2 utilization for polyols as a PUR precursor, to indirect CO2 utilization for basic chemicals in the PUR supply chain. In this paper, we present a systematic exploration and environmental evaluation of all direct and indirect CO2 utilization options for flexible and rigid PUR foams. The analysis is based on an LCA-based PUR supply chain optimization model using linear programming to identify PUR production with minimal environmental impacts. The direct utilization of CO2 for polyols allows for large specific impact reductions of up to 4 kg CO2-eq. and 2 kg oil-eq. per kg CO2 utilized, but the amounts of CO2 that can be utilized are limited to 0.30 kg CO2 per kg PUR. The amount of CO2 utilized can be increased to up to 1.7 kg CO2 per kg PUR by indirect CO2 utilization in the PUR supply chain. Indirect CO2 utilization requires hydrogen (H2). The environmental impacts of H2 production strongly affect the impact of indirect CO2 utilization in PUR. To achieve optimal environmental performance under the current fossil-based H2 generation, PUR production can only utilize much less CO2 than theoretically possible. Thus, utilizing as much CO2 in the PUR supply chain as possible is not always environmentally optimal. Clean H2 production is required to exploit the full CO2 utilization potential for environmental impact reduction in PUR production. PMID:26381106

  10. Plant roots alter microbial potential for mediation of soil organic carbon decomposition

    NASA Astrophysics Data System (ADS)

    Firestone, M.; Shi, S.; Herman, D.; He, Z.; Zhou, J.

    2014-12-01

    Plant root regulation of soil organic carbon (SOC) decomposition is a key controller of terrestrial C-cycling. Although many studies have tested possible mechanisms underlying plant "priming" of decomposition, few have investigated the microbial mediators of decomposition, which can be greatly influenced by plant activities. Here we examined effects of Avena fatua roots on decomposition of 13C-labeled root litter in a California grassland soil over two simulated growing-seasons. The presence of plant roots consistently suppressed rates of litter decomposition. Reduction of inorganic nitrogen (N) concentration in soil reduced but did not completely relieve this suppressive effect. The presence of plants significantly altered the abundance, composition and functional potential of microbial communities. Significantly higher signal intensities of genes capable of degrading low molecular weight organic compounds (e.g., glucose, formate and malate) were observed in microbial communities from planted soils, while microorganisms in unplanted soils had higher relative abundances of genes involved in degradation of some macromolecules (e.g., hemicellulose and lignin). Additionally, compared to unplanted soils, microbial communities from planted soils had higher signal intensities of proV and proW, suggesting microbial osmotic stress in planted soils. Possible mechanisms for the observed inhibition of decomposition are 1) microbes preferentially using simple substrates from root exudates and 2) soil drying by plant evapotranspiration impairing microbial activity. We propose a simple data-based model suggesting that the impacts of roots, the soil environment, and microbial community composition on decomposition processes result from impacts of these factors on the soil microbial functional gene potential.

  11. Carbon Sequestration Potential in Irrigated Agriculture: Greenhouse Gas Emissions and the Contribution of Water.

    NASA Astrophysics Data System (ADS)

    Rolston, D. E.; Hopmans, J. W.; van Kessel, C.; Six, J.; Paw U, K.; Plant, R.; Lee, J.; Kochendorfer, J.; Ideris, A. J.; MacIntyre, J.; Louie, D.; Matista, T.; Evatt, J.; Poch, R.; King, A. P.

    2006-12-01

    This study aimed to quantify CO2 and N2O release from an irrigated field in California's Sacramento Valley in an effort to determine greenhouse gas mitigation potentials through minimum tillage (MT) practices. Surface CO2 and N2O flux were monitored on the 30 ha, laser-leveled field site from September 2003 through August 2006. Additional field-representative flux data was collected from eddy-covariance masts and continuously sampling auto-chambers. Irrigation and run-off waters were collected and analyzed for total suspended solids (TSS), dissolved organic carbon (DOC), dissolved organic nitrogen (DON), nitrate-N, ammonium-N, total C and total N in the sediment. Overall, we found very little difference in CO2 flux, water composition, or sediment composition between the two tillage treatments. N2O flux was negligible in both systems until a fertilization and irrigation event occurred in each growing season, at which point the MT treatment showed slightly higher fluxes. NO3-N levels in the run-off exceeded drinking water quality standards only in irrigation events following fertilizer application. Collected CO2 and N2O data from this site will enable us to predict greenhouse gas emissions from similar agricultural systems in the California landscape. Our results indicate that the role of irrigation water in C budgets of agricultural systems is a significant factor in determining total C sequestration potential, but that short-term MT may not significantly decrease the contribution to global warming by irrigated agroecosystems and thus may not be a beneficial strategy for greenhouse gas mitigation.

  12. Polymer-Single Wall Carbon Nanotube Composites for Potential Spacecraft Applications

    NASA Technical Reports Server (NTRS)

    Park, C.; Ounaies, Z.; Watson, K. A.; Pawlowski, K.; Lowther, S. E.; Connell, J. W.; Siochi, E. J.; Harrison, J. S.; St.Clair, T. L.; Bushnell, Dennis M. (Technical Monitor)

    2002-01-01

    Polymer-single wall carbon nanotube (SWNT) composite films were prepared and characterized as part of an effort to develop polymeric materials with improved combinations of properties for potential use on future spacecraft. Next generation spacecraft will require ultra-lightweight materials that possess specific and unique combinations of properties such as radiation and atomic oxygen resistance, low solar absorptivity, high thermal emissitivity, electrical conductivity, tear resistance, ability to be folded and seamed, and good mechanical properties. The objective of this work is to incorporate sufficient electrical conductivity into space durable polyimides to mitigate static charge build-up. The challenge is to obtain this level of conductivity (10(exp -8) S/cm) without degrading other properties of importance, particularly optical transparency. Several different approaches were attempted to fully disperse the SWNTs into the polymer matrix. These included high shear mixing, sonication, and synthesizing the polymers in the presence of pre-dispersed SWNTs. Acceptable levels of conductivity were obtained at loading levels less than one tenth weight percent SWNT without significantly sacrificing optical properties. Characterization of the nanocomposite films and the effect of SWNT concentration and dispersion on the conductivity, solar absorptivity, thermal emissivity, mechanical and thermal properties were discussed. Fibers and non-woven porous mats of SWNT reinforced polymer nanocomposite were produced using electrospinning.

  13. Potential of surface-eroding poly(ethylene carbonate) for drug delivery to macrophages.

    PubMed

    Bohr, Adam; Water, Jorrit J; Wang, Yingya; Arnfast, Lærke; Beck-Broichsitter, Moritz

    2016-09-25

    Films composed of poly(ethylene carbonate) (PEC), a biodegradable polymer, were compared with poly(lactide-co-glycolide) (PLGA) films loaded with and without the tuberculosis drug rifampicin to study the characteristics and performance of PEC as a potential carrier for controlled drug delivery to macrophages. All drug-loaded PLGA and PEC films were amorphous indicating good miscibility of the drug in the polymers, even at high drug loading (up to 50wt.%). Polymer degradation studies showed that PLGA degraded slowly via bulk erosion while PEC degraded more rapidly and near-linearly via enzyme mediated surface erosion (by cholesterol esterase). Drug release studies performed with polymer films indicated a diffusion/erosion dependent delivery behavior for PLGA while an almost zero-order drug release profile was observed from PEC due to the controlled polymer degradation process. When exposed to polymer degradation products the murine macrophage cell line J774A.1 showed less susceptibility to PEC than to PLGA. However, when seeding the macrophages on PLGA and PEC films no relevant difference in cell proliferation/growth kinetics was observed. Overall, this study emphasizes that PEC is an attractive polymer for controlled drug release and could provide superior performance to PLGA for some drug delivery applications including the treatment of macrophage infections. PMID:27492019

  14. Enhancing Phenolic Contents and Antioxidant Potentials of Antidesma thwaitesianum by Supercritical Carbon Dioxide Extraction.

    PubMed

    Poontawee, Warut; Natakankitkul, Surapol; Wongmekiat, Orawan

    2015-01-01

    Supercritical fluid extraction (SFE) has increasingly gained attention as an alternative technique for extraction of natural products without leaving toxic residues in extracts. Antidesma thwaitesianum Muell. Arg. (Phyllanthaceae), or ma mao, has been reported to exhibit antioxidant health benefits due to its phenolic constituents. To determine whether SFE technique could impact on phenolic contents and associated antioxidant potentials, ripe fruits of Antidesma thwaitesianum (Phyllanthaceae) were extracted using supercritical carbon dioxide (SC-CO2) and conventional solvents (ethanol, water). The results showed that the SC-CO2 extract contained significantly higher yield, total phenolic, flavonoid, and proanthocyanidin contents than those obtained from ethanol and water. It also demonstrated the greatest antioxidant activities as assessed by ABTS radical cation decolorization, DPPH radical scavenging, and ferric reducing antioxidant power (FRAP) assays. Further analysis using high-performance liquid chromatography with diode array and mass spectrometry detectors (HPLC-DAD/MSD) revealed the presence of catechin as a major phenolic compound of Antidesma thwaitesianum (Phyllanthaceae), with the maximum amount detected in the SC-CO2 extract. These data indicate that SFE technology improves both quantity and quality of Antidesma thwaitesianum fruit extract. The findings added more reliability of using this technique to produce high added value products from this medicinal plant. PMID:25977832

  15. Microwave-assisted synthesis of wavelength-tunable photoluminescent carbon nanodots and their potential applications.

    PubMed

    Liu, Hongying; He, Zhimei; Jiang, Li-Ping; Zhu, Jun-Jie

    2015-03-01

    A facile and rapid strategy was developed for the synthesis of ultrabright luminescent carbon nanodots (CDs) with tunable wavelength from 464 to 556 nm by introducing glutaraldehyde into the precursor solution under microwave irradiation. The fluorescence properties, including excitation and emission wavelength, quantum yield, and size of the CDs, were adjusted by changing the amount of glutaraldehyde and poly(ethylenimine). Several methods such as high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and dynamic light scattering, UV-vis, fluorescence, and Fourier transform infrared spectroscopy were employed to study the morphology and the properties of CDs. The luminescence mechanism was also discussed. In addition, confocal microscopy imaging revealed that the as-prepared CDs could be used as effective fluorescent probes in the cell imaging without obvious cytotoxicity. Moreover, a novel sensor for the detection of Co(2+) was proposed on the basis of Co(2+)-induced fluorescence quenching. These superior properties demonstrated the potential application of the CDs in cellular imaging and ion sensing. PMID:25671342

  16. Enhancing Phenolic Contents and Antioxidant Potentials of Antidesma thwaitesianum by Supercritical Carbon Dioxide Extraction

    PubMed Central

    Poontawee, Warut; Natakankitkul, Surapol; Wongmekiat, Orawan

    2015-01-01

    Supercritical fluid extraction (SFE) has increasingly gained attention as an alternative technique for extraction of natural products without leaving toxic residues in extracts. Antidesma thwaitesianum Muell. Arg. (Phyllanthaceae), or ma mao, has been reported to exhibit antioxidant health benefits due to its phenolic constituents. To determine whether SFE technique could impact on phenolic contents and associated antioxidant potentials, ripe fruits of Antidesma thwaitesianum (Phyllanthaceae) were extracted using supercritical carbon dioxide (SC-CO2) and conventional solvents (ethanol, water). The results showed that the SC-CO2 extract contained significantly higher yield, total phenolic, flavonoid, and proanthocyanidin contents than those obtained from ethanol and water. It also demonstrated the greatest antioxidant activities as assessed by ABTS radical cation decolorization, DPPH radical scavenging, and ferric reducing antioxidant power (FRAP) assays. Further analysis using high-performance liquid chromatography with diode array and mass spectrometry detectors (HPLC-DAD/MSD) revealed the presence of catechin as a major phenolic compound of Antidesma thwaitesianum (Phyllanthaceae), with the maximum amount detected in the SC-CO2 extract. These data indicate that SFE technology improves both quantity and quality of Antidesma thwaitesianum fruit extract. The findings added more reliability of using this technique to produce high added value products from this medicinal plant. PMID:25977832

  17. Carbonic anhydrase IX correlates with survival and is a potential therapeutic target for neuroblastoma.

    PubMed

    Ameis, Helen M; Drenckhan, Astrid; Freytag, Morton; Izbicki, Jakob R; Supuran, Claudiu T; Reinshagen, Konrad; Holland-Cunz, Stefan; Gros, Stephanie J

    2016-06-01

    Carbonic anhydrase IX (CAIX) is involved in pathological processes including tumorgenicity, metastases and poor survival in solid tumors. Twenty-two neuroblastoma samples of patients who were surgically treated at the University Medical Center Hamburg-Eppendorf were evaluated immunohistochemically for expression of CAIX. Results were correlated with clinical parameters and outcome. Neuroblastoma Kelly and SH-EP-Tet-21/N cells were examined for CAIX expression and inhibited with specific inhibitors, FC5-207A and FC8-325A. 32% of neuroblastoma tumors expressed CAIX. This was significantly associated with poorer survival. Kelly and SH-EP-Tet-21/N cells showed a major increase of CAIX RNA under hypoxic conditions. Proliferation of Kelly cells was significantly decreased by CAIX inhibitors, FC5-207A and FC8-325A, while proliferation of SH-EP-Tet-21/N cells was only significantly affected by FC8-325A. CAIX is a potent biomarker that predicts survival in neuroblastoma patients. CAIX-targeted therapy in neuroblastoma cell lines is highly effective and strengthens the potential of CAIX as a clinical therapeutic target in a selected patient collective. PMID:25884234

  18. A modern literature review of carbon monoxide poisoning theories, therapies, and potential targets for therapy advancement.

    PubMed

    Roderique, Joseph D; Josef, Christopher S; Feldman, Michael J; Spiess, Bruce D

    2015-08-01

    The first descriptions of carbon monoxide (CO) and its toxic nature appeared in the literature over 100 years ago in separate publications by Drs. Douglas and Haldane. Both men ascribed the deleterious effects of this newly discovered gas to its strong interaction with hemoglobin. Since then the adverse sequelae of CO poisoning has been almost universally attributed to hypoxic injury secondary to CO occupation of oxygen binding sites on hemoglobin. Despite a mounting body of literature suggesting other mechanisms of injury, this pathophysiology and its associated oxygen centric therapies persists. This review attempts to elucidate the remarkably complex nature of CO as a gasotransmitter. While CO's affinity for hemoglobin remains undisputed, new research suggests that its role in nitric oxide release, reactive oxygen species formation, and its direct action on ion channels is much more significant. In the course of understanding the multifaceted character of this simple molecule it becomes apparent that current oxygen based therapies meant to displace CO from hemoglobin may be insufficient and possibly harmful. Approaching CO as a complex gasotransmitter will help guide understanding of the complex and poorly understood sequelae and illuminate potentials for new treatment modalities. PMID:25997893

  19. Simulations show decreasing carbon stocks and potential for carbon emissions in Rocky Mountain forests over the next century.

    PubMed

    Boisvenue, Céline; Running, Steven W

    2010-07-01

    Climate change has altered the environment in which forests grow, and climate change models predict more severe alterations to come. Forests have already responded to these changes, and the future temperature and precipitation scenarios are of foremost concern, especially in the mountainous western United States, where forests occur in the dry environments that interface with grasslands. The objective of this study was to understand the trade-offs between temperature and water controls on these forested sites in the context of available climate projections. Three temperature and precipitation scenarios from IPCC AR4 AOGCMs ranging in precipitation levels were input to the process model Biome-BGC for key forested sites in the northern U.S. Rocky Mountains. Despite the omission of natural and human-caused disturbances in our simulations, our results show consequential effects from these conservative future temperature and precipitation scenarios. According to these projections, if future precipitation and temperatures are similar to or drier than the dry scenario depicted here, high-elevation forests on both the drier and wetter sites, which have in the absence of disturbance accumulated carbon, will reduce their carbon accumulation. Under the marginally drier climate projections, most forests became carbon sources by the end of the simulation horizon (2089). Under all three scenarios, growing season lengthened, the number of days with snow on the ground decreased, peak snow occurred earlier, and water stress increased through the projection horizon (1950-2089) for all sites, which represent the temperature and precipitation spectrum of forests in this region. The quantity, form, and timing of precipitation ultimately drive the carbon accumulation trajectory of forests in this region. PMID:20666251

  20. Quantitative Assessment of the Potential of Afforestation for Carbon Dioxide Removal: Evaluating carbon sequestration and biogeophysical impacts in a dynamic global vegetation model

    NASA Astrophysics Data System (ADS)

    Littleton, E. W.

    2015-12-01

    This study presents a new method for representing permanent afforestation in Earth System models. Afforestation has attracted interest as an option to help to slow or reverse the growth of atmospheric carbon dioxide during the next century. However, its potential is poorly constrained with regard to land availability, rates of tree growth and carbon accumulation, and potential side effects. This study aims to provide quantitative assessment of the carbon removal potential and side effects of 21st century afforestation using a dynamic global vegetation model, in contrast to the majority of previous estimates which have used bookkeeping methods. The land surface model JULES was used to simulate needleleaf afforestation on abandoned agricultural land during the 21st century under two future pathways (RCP4.5 and RCP8.5). These results are compared to a control scenario in which natural succession is allowed to act on the same area of land. This study finds considerable spatial variation in the final carbon sequestration potential of afforestation sites. In addition to dieback and marginal growth in many regions, many sites showed minimal additionality of forest areas compared to natural succession. The most suitable sites were in Eastern Europe, central China and central North America. There was no major difference in the general spatial pattern of suitability between RCP4.5 and RCP8.5 by 2100. Overall, this study produced a significantly smaller estimate of the CDR potential of permanent afforestation than previous studies have. The additional carbon stored in suitable sites by 2100 was only 19 Pg C (RCP4.5) and 2.1 Pg C (RCP8.5), a mean of 68 tC/ha. This research also explored the biogeophysical impacts of afforestation on surface energy balance and hydrological cycles. The decrease in albedo caused by afforestation significantly offset the radiative forcing benefits of the carbon removal, although this effect was very sensitive to input assumptions. Flooding results

  1. Effect of nitrate, organic carbon, and temperature on potential denitrification rates in nitrate-rich riverbed sediments

    USGS Publications Warehouse

    Pfenning, K.S.; McMahon, P.B.

    1997-01-01

    A study conducted in 1994 as part of the US Geological Survey's National Water-Quality Assessment Program, South Platte River Basin investigation, examined the effect of certain environmental factors on potential denitrification rates in nitrate-rich riverbed sediments. The acetylene block technique was used to measure nitrous oxide (N2O) production rates in laboratory incubations of riverbed sediments to evaluate the effect of varying nitrate concentrations, organic carbon concentrations and type, and water temperature on potential denitrification rates. Sediment incubations amended with nitrate, at concentrations ranging from 357 to 2142 ??mol l-1 (as measured in the field), produced no significant increase (P > 0.05) in N2O production rates, indicating that the denitrification potential in these sediments was not nitrate limited. In contrast, incubations amended with acetate as a source of organic carbon, at concentrations ranging from 0 to 624 ??mol l-1, produced significant increases (P < 0.05) in N2O production rates with increased organic carbon concentration, indicating that the denitrification potential in these sediments was organic carbon limited. Furthermore, N2O production rates also were affected by the type of organic carbon available as an electron donor. Acetate and surface-water-derived fulvic acid supported higher N2O production rates than groundwater-derived fulvic acid or sedimentary organic carbon. Lowering incubation temperatures from 22 to 4??C resulted in about a 77% decrease in the N2O production rates. These results help to explain findings from previous studies indicating that only 15-30% of nitrate in groundwater was denitrified before discharging to the South Platte River and that nitrate concentrations in the river generally were higher in winter than in summer.

  2. Removal potential of toxic 2378-substituted PCDD/F from incinerator flue gases by waste-derived activated carbons.

    PubMed

    Hajizadeh, Yaghoub; Onwudili, Jude A; Williams, Paul T

    2011-06-01

    The application of activated carbons has become a commonly used emission control protocol for the removal or adsorption of persistent organic pollutants from the flue gas streams of waste incinerators. In this study, the 2378-substituted PCDD/F removal efficiency of three types of activated carbons derived from the pyrolysis of refuse derived fuel, textile waste and scrap tyre was investigated and compared with that of a commercial carbon. Experiments were carried out in a laboratory scale fixed-bed reactor under a simulated flue gas at 275°C with a reaction period of four days. The PCDD/F in the solid matrices and exhaust gas, were analyzed using gas chromatography coupled with a triple quadrupole mass spectrometer. In the absence of activated carbon adsorbent, there was a significant increase in the concentration of toxic PCDD/F produced in the reacted flyash, reaching up to 6.6 times higher than in the raw flyash. In addition, there was a substantial release of PCDD/F into the gas phase, which was found in the flue gas trapping system. By application of the different commercial, refuse derived fuel, textile and tyre activated carbons the total PCDD/F toxic equivalent removal efficiencies in the exhaust gas stream were 58%, 57%, 64% and 52%, respectively. In general, the removal of the PCDDs was much higher with an average of 85% compared to PCDFs at 41%. Analysis of the reacted activated carbons showed that there was some formation of PCDD/F, for instance, a total of 60.6 μg I-TEQ kg(-1) toxic PCDD/F was formed in the refuse derived fuel activated carbon compared to 34 μg I-TEQ kg(-1) in the commercial activated carbon. The activated carbons derived from the pyrolysis of waste, therefore, showed good potential as a control material for PCDD/F emissions in waste incinerator flue gases. PMID:21334872

  3. Removal potential of toxic 2378-substituted PCDD/F from incinerator flue gases by waste-derived activated carbons

    SciTech Connect

    Hajizadeh, Yaghoub; Onwudili, Jude A.; Williams, Paul T.

    2011-06-15

    The application of activated carbons has become a commonly used emission control protocol for the removal or adsorption of persistent organic pollutants from the flue gas streams of waste incinerators. In this study, the 2378-substituted PCDD/F removal efficiency of three types of activated carbons derived from the pyrolysis of refuse derived fuel, textile waste and scrap tyre was investigated and compared with that of a commercial carbon. Experiments were carried out in a laboratory scale fixed-bed reactor under a simulated flue gas at 275 deg. C with a reaction period of four days. The PCDD/F in the solid matrices and exhaust gas, were analyzed using gas chromatography coupled with a triple quadrupole mass spectrometer. In the absence of activated carbon adsorbent, there was a significant increase in the concentration of toxic PCDD/F produced in the reacted flyash, reaching up to 6.6 times higher than in the raw flyash. In addition, there was a substantial release of PCDD/F into the gas phase, which was found in the flue gas trapping system. By application of the different commercial, refuse derived fuel, textile and tyre activated carbons the total PCDD/F toxic equivalent removal efficiencies in the exhaust gas stream were 58%, 57%, 64% and 52%, respectively. In general, the removal of the PCDDs was much higher with an average of 85% compared to PCDFs at 41%. Analysis of the reacted activated carbons showed that there was some formation of PCDD/F, for instance, a total of 60.6 {mu}g I-TEQ kg{sup -1} toxic PCDD/F was formed in the refuse derived fuel activated carbon compared to 34 {mu}g I-TEQ kg{sup -1} in the commercial activated carbon. The activated carbons derived from the pyrolysis of waste, therefore, showed good potential as a control material for PCDD/F emissions in waste incinerator flue gases.

  4. Dimethyl carbonate as potential reactant in non-catalytic biodiesel production by supercritical method.

    PubMed

    Ilham, Zul; Saka, Shiro

    2009-03-01

    In this study, the non-catalytic supercritical method has been studied in utilizing dimethyl carbonate. It was demonstrated that, the supercritical dimethyl carbonate process without any catalysts applied, converted triglycerides to fatty acid methyl esters with glycerol carbonate and citramalic acid as by-products, while free fatty acids were converted to fatty acid methyl esters with glyoxal. After 12 min of reaction at 350 degrees C/20 MPa, rapeseed oil treated with supercritical dimethyl carbonate reached 94% (w/w) yield of fatty acid methyl ester. The by-products from this process which are glycerol carbonate and citramalic acid are much higher in value than glycerol produced by the conventional process. In addition, the yield of the fatty acid methyl esters as biodiesel was almost at par with supercritical methanol method. Therefore, supercritical dimethyl carbonate process can be a good candidate as an alternative biodiesel production process. PMID:18990561

  5. Calcifying cyanobacteria--the potential of biomineralization for carbon capture and storage.

    PubMed

    Jansson, Christer; Northen, Trent

    2010-06-01

    Employment of cyanobacteria in biomineralization of carbon dioxide by calcium carbonate precipitation offers novel and self-sustaining strategies for point-source carbon capture and sequestration. Although details of this process remain to be elucidated, a carbon-concentrating mechanism, and chemical reactions in exopolysaccharide or proteinaceous surface layers are assumed to be of crucial importance. Cyanobacteria can utilize solar energy through photosynthesis to convert carbon dioxide to recalcitrant calcium carbonate. Calcium can be derived from sources such as gypsum or industrial brine. A better understanding of the biochemical and genetic mechanisms that carry out and regulate cynaobacterial biomineralization should put us in a position where we can further optimize these steps by exploiting the powerful techniques of genetic engineering, directed evolution, and biomimetics. PMID:20456936

  6. Calcifying Cyanobacteria - The potential of biomineralization for Carbon Capture and Storage

    SciTech Connect

    Jansson, Christer G; Northen, Trent

    2010-03-26

    Employment of cyanobacteria in biomineralization of carbon dioxide by calcium carbonate precipitation offers novel and self-sustaining strategies for point-source carbon capture and sequestration. Although details of this process remain to be elucidated, a carbon-concentrating mechanism, and chemical reactions in exopolysaccharide or proteinaceous surface layers are assumed to be of crucial importance. Cyanobacteria can utilize solar energy through photosynthesis to convert carbon dioxide to recalcitrant calcium carbonate. Calcium can be derived from sources such as gypsum or industrial brine. A better understanding of the biochemical and genetic mechanisms that carry out and regulate cynaobacterial biomineralization should put us in a position where we can further optimize these steps by exploiting the powerful techniques of genetic engineering, directed evolution, and biomimetics.

  7. Abatement vs. treatment for efficient diffuse source water pollution management in terrestrial-marine systems.

    PubMed

    Roebeling, P C; Cunha, M C; Arroja, L; van Grieken, M E

    2015-01-01

    Marine ecosystems are affected by water pollution originating from coastal catchments. The delivery of water pollutants can be reduced through water pollution abatement as well as water pollution treatment. Hence, sustainable economic development of coastal regions requires balancing of the marginal costs from water pollution abatement and/or treatment and the associated marginal benefits from marine resource appreciation. Water pollution delivery reduction costs are, however, not equal across abatement and treatment options. In this paper, an optimal control approach is developed and applied to explore welfare maximizing rates of water pollution abatement and/or treatment for efficient diffuse source water pollution management in terrestrial-marine systems. For the case of diffuse source dissolved inorganic nitrogen water pollution in the Tully-Murray region, Queensland, Australia, (agricultural) water pollution abatement cost, (wetland) water pollution treatment cost and marine benefit functions are determined to explore welfare maximizing rates of water pollution abatement and/or treatment. Considering partial (wetland) treatment costs and positive water quality improvement benefits, results show that welfare gains can be obtained, primarily, through diffuse source water pollution abatement (improved agricultural management practices) and, to a minor extent, through diffuse source water pollution treatment (wetland restoration). PMID:26287831

  8. Whitings as a Potential Mechanism for Controlling Atmospheric Carbon Dioxide Concentrations – Final Project Report

    SciTech Connect

    Brady D. Lee; William A. Apel; Michelle R. Walton

    2006-03-01

    Species of cyanobacteria in the genera Synechococcus and Synechocystis are known to be the catalysts of a phenomenon called "whitings", which is the formation and precipitation of fine-grained CaCO3 particles. Whitings occur when the cyanobacteria fix atmospheric CO2 through the formation of CaCO3 on their cell surfaces which leads to precipitation to the ocean floor and subsequent entombment in mud. Whitings represent one potential mechanism for CO2 sequestration. Research was performed to determine the ability of various strains of Synechocystis and Synechococcus to calcify when grown in microcosms amended with 2.5 mM HCO3- and 3.4 mM Ca2+. Results indicated that while all strains tested have the ability to calcify, only two, Synechococcus species, strains PCC 8806 and PCC 8807, were able to calcify to the extent that CaCO3 was precipitated. Enumeration of the cyanobacterial cultures during testing indicated that cell density did not appear to have an effect on calcification. Factors that had the greatest effect on calcification were CO2 removal and subsequent generation of alkaline pH. As CO2 was removed, growth medium pH increased and soluble Ca2+ was removed from solution. The largest increases in growth medium pH occurred when CO2 levels dropped below 400 ppmv. Precipitation of CaCO3 catalyzed by the growth and physiology of cyanobacteria in the Genus Synechococcus represents a potential mechanism for sequestration of atmospheric CO2 produced during the burning of coal for power generation. Synechococcus sp. strain PCC 8806 and Synechococcus sp. strain PCC 8807 were tested in microcosm experiments for their ability to calcify when exposed to a fixed calcium concentration of 3.4 mM and dissolved inorganic carbon concentrations of 0.5, 1.25 and 2.5 mM. Synechococcus sp. strain PCC 8806 removed calcium continuously over the duration of the experiment producing approximately 18.6 mg of solid-phase calcium. Calcium removal occurred over a two-day time period when

  9. Comparison of caprock pore networks which potentially will be impacted by carbon sequestration projects

    NASA Astrophysics Data System (ADS)

    Mouzakis, K. M.; Sitchler, A.; McCray, J. E.; Rother, G.; Dewers, T.; Heath, J. E.

    2010-12-01

    Injection of CO2 into underground rock formations can reduce atmospheric CO2 emissions. Caprocks present above potential storage formations are the main structural trap inhibiting CO2 from leaking into overlying aquifers or back to the Earth’s surface. Dissolution and precipitation of caprock minerals resulting from reaction with CO2 may alter the pore network where many pores are of the micrometer to nanometer scale, thus altering the structural trapping potential of the caprock. However, the distribution, geometry and volume of pores at these scales are poorly characterized. In order to evaluate the overall risk of leakage of CO2 from storage formations, a first critical step is understanding the distribution and shape of pores in a variety of different caprocks. As the caprock is often comprised of mudstones, we analyzed samples from several mudstone formations with small angle neutron scattering (SANS) and high-resolution transmission electron microscopy (TEM) imaging to compare the pore networks. Mudstones were chosen from current or potential sites for carbon sequestration projects including the Marine Tuscaloosa Group, the Lower Tuscaloosa Group, the upper and lower shale members of the Kirtland Formation, and the Pennsylvanian Gothic shale. Expandable clay contents ranged from 10% to approximately 40% in the Gothic shale and Kirtland Formation, respectively. During SANS, neutrons effectively scatter from interfaces between materials with differing scattering length density (i.e., minerals and pores). The intensity of scattered neutrons, I(Q), where Q is the scattering vector, gives information about the volume and arrangement of pores in the sample. The slope of the scattering data when plotted as log I(Q) vs. log Q provides information about the fractality or geometry of the pore network. On such plots slopes from -2 to -3 represent mass fractals while slopes from -3 to -4 represent surface fractals. Scattering data showed surface fractal dimensions for

  10. Comparison of caprock pore networks which potentially will be impacted by carbon sequestration projects.

    SciTech Connect

    McCray, John; Navarre-Sitchler, Alexis; Mouzakis, Katherine; Heath, Jason E.; Dewers, Thomas A.; Rother, Gernot

    2010-12-01

    Injection of CO2 into underground rock formations can reduce atmospheric CO2 emissions. Caprocks present above potential storage formations are the main structural trap inhibiting CO2 from leaking into overlying aquifers or back to the Earth's surface. Dissolution and precipitation of caprock minerals resulting from reaction with CO2 may alter the pore network where many pores are of the micrometer to nanometer scale, thus altering the structural trapping potential of the caprock. However, the distribution, geometry and volume of pores at these scales are poorly characterized. In order to evaluate the overall risk of leakage of CO2 from storage formations, a first critical step is understanding the distribution and shape of pores in a variety of different caprocks. As the caprock is often comprised of mudstones, we analyzed samples from several mudstone formations with small angle neutron scattering (SANS) and high-resolution transmission electron microscopy (TEM) imaging to compare the pore networks. Mudstones were chosen from current or potential sites for carbon sequestration projects including the Marine Tuscaloosa Group, the Lower Tuscaloosa Group, the upper and lower shale members of the Kirtland Formation, and the Pennsylvanian Gothic shale. Expandable clay contents ranged from 10% to approximately 40% in the Gothic shale and Kirtland Formation, respectively. During SANS, neutrons effectively scatter from interfaces between materials with differing scattering length density (i.e., minerals and pores). The intensity of scattered neutrons, I(Q), where Q is the scattering vector, gives information about the volume and arrangement of pores in the sample. The slope of the scattering data when plotted as log I(Q) vs. log Q provides information about the fractality or geometry of the pore network. On such plots slopes from -2 to -3 represent mass fractals while slopes from -3 to -4 represent surface fractals. Scattering data showed surface fractal dimensions for

  11. Carbonate precipitation under bulk acidic conditions as a potential biosignature for searching life on Mars

    NASA Astrophysics Data System (ADS)

    Fernández-Remolar, David C.; Preston, Louisa J.; Sánchez-Román, Mónica; Izawa, Matthew R. M.; Huang, L.; Southam, Gordon; Banerjee, Neil R.; Osinski, Gordon R.; Flemming, Roberta; Gómez-Ortíz, David; Prieto Ballesteros, Olga; Rodríguez, Nuria; Amils, Ricardo; Darby Dyar, M.

    2012-10-01

    Recent observations of carbonate minerals in ancient Martian rocks have been interpreted as evidence for the former presence of circumneutral solutions optimal for carbonate precipitation. Sampling from surface and subsurface regions of the low-pH system of Río Tinto has shown, unexpectedly, that carbonates can form under diverse macroscopic physicochemical conditions ranging from very low to neutral pH (1.5-7.0). A multi-technique approach demonstrates that carbonate minerals are closely associated with microbial activity. Carbonates occur in the form of micron-size carbonate precipitates under bacterial biofilms, mineralization of subsurface colonies, and possible biogenic microstructures including globules, platelets and dumbbell morphologies. We propose that carbonate precipitation in the low-pH environment of Río Tinto is a process enabled by microbially-mediated neutralization driven by the reduction of ferric iron coupled to the oxidation of biomolecules in microbially-maintained circumneutral oases, where the local pH (at the scale of cells or cell colonies) can be much different than in the macroscopic environment. Acidic conditions were likely predominant in vast regions of Mars over the last four billion years of planetary evolution. Ancient Martian microbial life inhabiting low-pH environments could have precipitated carbonates similar to those observed at Río Tinto. Preservation of carbonates at Río Tinto over geologically significant timescales suggests that similarly-formed carbonate minerals could also be preserved on Mars. Such carbonates could soon be observed by the Mars Science Laboratory, and by future missions to the red planet.

  12. Potential for Woody Bioenergy Crops Grown on Marginal Lands in the US Midwest to Reduce Carbon Emissions

    NASA Astrophysics Data System (ADS)

    Sahajpal, R.; Hurtt, G. C.; Fisk, J. P.; Izaurralde, R. C.; Zhang, X.

    2012-12-01

    While cellulosic biofuels are widely considered to be a low carbon energy source for the future, a comprehensive assessment of the environmental sustainability of existing and future biofuel systems is needed to assess their utility in meeting US energy and food needs without exacerbating environmental harm. To assess the carbon emission reduction potential of cellulosic biofuels, we need to identify lands that are initially not storing large quantities of carbon in soil and vegetation but are capable of producing abundant biomass with limited management inputs, and accurately model forest production rates and associated input requirements. Here we present modeled results for carbon emission reduction potential and cellulosic ethanol production of woody bioenergy crops replacing existing native prairie vegetation grown on marginal lands in the US Midwest. Marginal lands are selected based on soil properties describing use limitation, and are extracted from the SSURGO (Soil Survey Geographic) database. Yield estimates for existing native prairie vegetation on marginal lands modeled using the process-based field-scale model EPIC (Environmental Policy Integrated Climate) amount to ~ 6.7±2.0 Mg ha-1. To model woody bioenergy crops, the individual-based terrestrial ecosystem model ED (Ecosystem Demography) is initialized with the soil organic carbon stocks estimated at the end of the EPIC simulation. Four woody bioenergy crops: willow, southern pine, eucalyptus and poplar are parameterized in ED. Sensitivity analysis of model parameters and drivers is conducted to explore the range of carbon emission reduction possible with variation in woody bioenergy crop types, spatial and temporal resolution. We hypothesize that growing cellulosic crops on these marginal lands can provide significant water quality, biodiversity and GHG emissions mitigation benefits, without accruing additional carbon costs from the displacement of food and feed production.

  13. Carbon Capture and Storage

    SciTech Connect

    Friedmann, S

    2007-10-03

    Carbon capture and sequestration (CCS) is the long-term isolation of carbon dioxide from the atmosphere through physical, chemical, biological, or engineered processes. This includes a range of approaches including soil carbon sequestration (e.g., through no-till farming), terrestrial biomass sequestration (e.g., through planting forests), direct ocean injection of CO{sub 2} either onto the deep seafloor or into the intermediate depths, injection into deep geological formations, or even direct conversion of CO{sub 2} to carbonate minerals. Some of these approaches are considered geoengineering (see the appropriate chapter herein). All are considered in the 2005 special report by the Intergovernmental Panel on Climate Change (IPCC 2005). Of the range of options available, geological carbon sequestration (GCS) appears to be the most actionable and economic option for major greenhouse gas reduction in the next 10-30 years. The basis for this interest includes several factors: (1) The potential capacities are large based on initial estimates. Formal estimates for global storage potential vary substantially, but are likely to be between 800 and 3300 Gt of C (3000 and 10,000 Gt of CO{sub 2}), with significant capacity located reasonably near large point sources of the CO{sub 2}. (2) GCS can begin operations with demonstrated technology. Carbon dioxide has been separated from large point sources for nearly 100 years, and has been injected underground for over 30 years (below). (3) Testing of GCS at intermediate scale is feasible. In the US, Canada, and many industrial countries, large CO{sub 2} sources like power plants and refineries lie near prospective storage sites. These plants could be retrofit today and injection begun (while bearing in mind scientific uncertainties and unknowns). Indeed, some have, and three projects described here provide a great deal of information on the operational needs and field implementation of CCS. Part of this interest comes from several

  14. Nitrogen-doped carbon nanotube as a potential metal-free catalyst for CO oxidation.

    PubMed

    Lin, I-Hsiang; Lu, Yu-Huan; Chen, Hsin-Tsung

    2016-04-28

    We elucidate the possibility of nitrogen-doped carbon nanotube as a robust catalyst for CO oxidation. We have performed first-principles calculations considering the spin-polarization effect to demonstrate the reaction of CO oxidation catalyzed by the nitrogen-doped carbon nanotube. The calculations show that O2 species can be partially reduced with charge transfer from the nitrogen-doped carbon nanotube and directly chemisorbed on the C-N sites of the nitrogen-doped carbon nanotube. The partially reduced O2 species at the C-N sites can further directly react with a CO molecule via the Eley-Rideal mechanism with the barriers of 0.45-0.58 eV for the different diameter of nanotube. Ab initio molecular dynamics (AIMD) simulations were performed and showed that the oxidation of CO occurs by the Eley-Rideal mechanism. The relationship between the curvature and reactivity of the nitrogen doped carbon nanotube was also unraveled. It appears that the barrier height of the rate-limiting step depends on the curvature of the nitrogen-doped carbon nanotube in the trend of (3,3)-NCNT < (4,4)-NCNT < (5,5)-NCNT (decreases with increased curvature). Using this relationship, we can predict the barriers for other N-doped carbon nanotubes with different tube diameters. Our results reveal that the nitrogen doped carbon nanomaterials can be a good, low-cost, and metal-free catalyst for CO oxidation. PMID:27074831

  15. Cellulose-based carbon-A potential anode material for lithium-ion battery

    NASA Astrophysics Data System (ADS)

    Kierzek, Krzysztof; Piotrowska, Aleksandra; Machnikowski, Jacek

    2015-11-01

    A series of hard carbons was produced by the carbonization of microcrystalline cellulose powder in the temperature range of 950-1100 °C. The properties of the carbons were characterized using elemental analysis, X-ray diffraction and N2 and CO2 adsorption. The effect of heat-treatment temperature (HTT), pyrolytic carbon (PC) coating and discharging mode on the lithium insertion/deinsertion behavior of the carbons was assessed in a coin-type half-cell with metal lithium cathode. Increasing cellulose HTT modifies mostly carbon porosity, the surface area (SDFT) decreases from about 500 to 167 m2 g-1. It is associated with lowering the reversible Crev and irreversible Cirr capacities, but without improving relatively low (0.72) 1st cycle coulombic efficiency. Applying constant current (CC)+constant voltage (CV) discharging mode instead of conventional CC enhances the reversible capacity by 15-18%. PC coating is effective in reducing Cirr by ∼20% with a little change of Crev. The best capacity parameters, Crev of 458 mA h g-1 and Cirr of 139 mA h g-1, were measured for PC coated 1000 °C carbon. The prolonged cycling of full-cell assembled with anode of the carbon and commercial cathode revealed that after initial 20 cycles the capacity decay (0.029 mA h/cycle) is comparable to that of commercial cell with graphite-based anode.

  16. Potential drivers for soil carbon pools in residential areas in Auburn, Alabama

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Metropolitan areas are expanding worldwide and residential zones are a major contributor. The turf ecosystems of residential yards can be highly productive and accumulate soil carbon undisturbed for decades. Because little is known about urban soil carbon (C) pools in the southeast, we performed thi...

  17. Geomembranes containing powdered activated carbon have the potential to improve containment of chlorinated aromatic contaminants.

    PubMed

    Surdo, Erin M; Cussler, Edward L; Novak, Paige J; Arnold, William A

    2009-12-01

    Breakthrough across high-density polyethylene (HDPE) was measured for 2,3',4',5-tetrachlorobiphenyl and a higher-solubility surrogate, 1,2,4-trichlorobenzene. Addition of powdered activated carbon (0.14 g carbon/cm(3) membrane) reduced pseudo-steady-state flux through thin HDPE membranes by approximately 60%. Breakthrough curves for activated carbon-containing membranes were best described by a model in which sorption to the carbon was limited by the rate of diffusion from the bulk membrane to the carbon particle surfaces. Field-scale estimates based on this model show a substantial (over 10 orders of magnitude) reduction in flux for the activated carbon-containing HDPE compared with pure HDPE. The flux of 2,3',4',5-tetrachlorobiphenyl through a composite membrane with thin layers of poly(vinyl alcohol) (PVA) with 0.05 g carbon/cm(3) and pure HDPE was 69% lower than expected for a similar layered membrane without the sorptive scavenger. This flux reduction was achieved with less than a third of the carbon used in the HDPE case, an improvement that is likely the result of better solute uptake in the hydrophilic PVA layer. PMID:19943666

  18. POTENTIAL OF FORESTRY AND AGROFORESTRY PRACTICES TO STORE CARBON IN THE TROPICS

    EPA Science Inventory

    Terrestrial vegetation plays a pivotal role in the global carbon cycle. ot only are tremendous amounts of. carbon stored in terrestrial egetation, but large amounts are also actively exchanged,between vegetation and the atmosphere. his suggests that vegetation, and specifically f...

  19. Soil lead abatement and children's blood lead levels in an urban setting.

    PubMed Central

    Farrell, K P; Brophy, M C; Chisolm, J J; Rohde, C A; Strauss, W J

    1998-01-01

    OBJECTIVES: The effect of abating soil lead was assessed among Baltimore children. The hypothesis was that a reduction of 1000 parts per million would reduce children's blood lead levels by 0.14 to 0.29 mumol/L (3-6 micrograms/dL). METHODS: In 2 neighborhoods (study and control), 187 children completed the protocol. In the study area, contaminated soil was replaced with clean soil. RESULTS: Soil lead abatement in this study did not lower children's blood lead. CONCLUSIONS: Although it did not show an effect in this study, soil lead abatement may be useful in certain areas. PMID:9842383

  20. Carbon mitigation potential and costs of forestry options in Brazil, China, India, Indonesia, Mexico, the Philippines and Tanzania

    SciTech Connect

    Sathaye, J.; Makundi, W.; Andrasko, K.; Boer, R.; Ravindranath, N.; Sudha, P.; Rao, S.; Lasco, R.; Pulhin, F.; Masera, O.; Ceron, A.; Ordonez, J.; Deying, X.; Zhang, X.; Zuomin, S.

    2001-01-01

    This paper summarizes studies of carbon (C) mitigation potential and costs of about 40 forestry options in seven developing countries. Each study uses the same methodological approach - Comprehensive Mitigation Assessment Process (COMAP) - to estimate the above parameters between 2000 and 2030. The approach requires the projection of baseline and mitigation land-use scenarios. Coupled with data on a per ha basis on C sequestration or avoidance, and costs and benefits, it allows the estimation of monetary benefit per Mg C, and the total costs and carbon potential. The results show that about half (3.0 Pg C) the cumulative mitigation potential of 6.2 Petagram (Pg) C between 2000 and 2030 in the seven countries (about 200 x 106 Mg C yr-1) could be achieved at a negative cost and the remainder at costs ranging up to $100 Mg C-1. About 5 Pg C could be achieved, at a cost less than $20 per Mg C. Negative cost potential indicates that non-carbon revenue is sufficient to offset direct costs of these options. The achievable potential is likely to be smaller, however, due to market, institutional, and sociocultural barriers that can delay or prevent the implementation of the analyzed options.

  1. Potential for long-term transfer of dissolved organic carbon from riparian zones to streams in boreal catchments.

    PubMed

    Ledesma, José L J; Grabs, Thomas; Bishop, Kevin H; Schiff, Sherry L; Köhler, Stephan J

    2015-08-01

    Boreal regions store most of the global terrestrial carbon, which can be transferred as dissolved organic carbon (DOC) to inland waters with implications for both aquatic ecology and carbon budgets. Headwater riparian zones (RZ) are important sources of DOC, and often just a narrow 'dominant source layer' (DSL) within the riparian profile is responsible for most of the DOC export. Two important questions arise: how long boreal RZ could sustain lateral DOC fluxes as the sole source of exported carbon and how its hydromorphological variability influences this role. We estimate theoretical turnover times by comparing carbon pools and lateral exports in the DSL of 13 riparian profiles distributed over a 69 km(2) catchment in northern Sweden. The thickness of the DSL was 36 ± 18 (average ± SD) cm. Thus, only about one-third of the 1-m-deep riparian profile contributed 90% of the lateral DOC flux. The 13 RZ exported 8.7 ± 6.5 g C m(-2) year(-1) , covering the whole range of boreal stream DOC exports. The variation could be explained by local hydromorphological characteristics including RZ width (R(2) = 0.90). The estimated theoretical turnover times were hundreds to a few thousands of years, that is there is a potential long-lasting supply of DOC. Estimates of net ecosystem production in the RZ suggest that lateral fluxes, including both organic and inorganic C, could be maintained without drawing down the riparian pools. This was supported by measurements of stream DO(14) C that indicated modern carbon as the predominant fraction exported, including streams disturbed by ditching. The transfer of DOC into boreal inland waters from new and old carbon sources has a major influence on surface water quality and global carbon balances. This study highlights the importance of local variations in RZ hydromorphology and DSL extent for future DOC fluxes under a changing climate. PMID:25611952

  2. The potential for increasing the use of catalytic carbons in commercial applications

    USGS Publications Warehouse

    Kruse, C.W.

    1996-01-01

    A carbon catalyst, prepared either by oxidizing activated carbon with air at 500-700??C or by oxidizing activated carbon with boiling nitric acid followed by heating it to 500-700??C, is the subject of this paper. This catalyst, designated OAC500-700, catalyzes the removal of hydrogen chloride from alkyl halides. Because OAC500-700 retains adsorptive properties of an activated carbon it can be used both to adsorb pollutants from liquid or gaseous streams and to convert them to recyclable products. A highly-developed micropore structure is not required for all uses of activated carbon or a catalyst produced from it. A comparatively inexpensive ($325/ton projected) low surface area (<300 m2/g) carbon has been developed at the Illinois State Geological Survey (ISGS) for cleaning incinerator flue gas. This grade of activated carbon is widely used in Europe for flue gas cleaning and for other applications. Activated carbon adsorbers of some type are required by recently passed U.S. Environmental Protection Agency (EPA) regulations for municipal waste combustors to control emission of cadmium, mercury, lead, dioxins, furans and acid gases (U.S. EPA, 1995). Similar regulations are expected for hospital and hazardous waste incinerators. The marketing of less costly activated carbons of the type used widely in Europe is expected in the United States. Low cost OAC500-700 made from less expensive grades of activated carbon may become available for large scale adsorbent/catalyst systems designed to both remove and decompose toxic pollutants found in liquid and gaseous streams, chlorinated organic compounds in particular.

  3. Carbon storage in Swedish bedrock - current status regarding potential storage areas and geophysical information

    NASA Astrophysics Data System (ADS)

    Bergman, B.; Juhojuntti, N. G.

    2010-12-01

    Carbon Capture and Storage (CCS) is increasingly considered as an option to reduce the release of CO2 to the atmosphere. There is today a significant interest from Swedish heavy industry in CCS-technology. Large point sources are found within process industry related to e.g. production of paper and steel (operating under European Union regulations). There is also significant emission of CO2 from burning of biomass for energy production. However, this process is considered to be climate neutral and thus the emissions are not included in the carbon trading schemes. Based on recent work at the Geological Survey of Sweden and by other organizations we discuss the possibilities for geological storage of CO2 in Sweden, including the locations of the potential storage sites and the main CO2 emitters. In this context, we also review the relevant geophysical data available at the Geological Survey, focusing on the seismic data but also including gravity and magnetic data. Deep saline aquifers are presently considered as the most realistic storage alternative in Sweden. Sedimentary bedrock containing such layers and which could be suitable for CO2 storage is mainly found within the southern Baltic Sea and around southernmost Sweden, close to Denmark. The knowledge about the sedimentary bedrock in these areas is mainly based on seismic measurements and drilling in connection with hydrocarbon prospecting during the 70’s and the 80’s. Approximately 40.000 km’s of seismic reflection profiles were acquired, mostly in the potential CO2 storage areas mentioned above. Data from these profiles are now archived at the Geological Survey, and currently the magnetic tapes (8000-9000 reels) are being transcribed to modern storage media, a work that will likely be finished during 2011. Despite the hydrocarbon prospecting in these areas there are remaining uncertainties regarding the suitability of the sedimentary bedrock for CO2 storage, in particular related to the porosity and

  4. Synergies and liabilities: a full-cost approach to the abatement of greenhouse gas fluxes in row-crop agriculture

    NASA Astrophysics Data System (ADS)

    Philip Robertson, G.; Grace, P. R.

    2003-04-01

    According to the IPCC TAR, agriculture is responsible for 21-25% of the global anthropic CO2 flux, 55-60% of the anthropic CH4 flux, and 65-80% of the anthropic flux of N2O. A number of CO2 stabilization strategies target agricultural production practices, and the potential for simultaneously abating fluxes of the non-CO2 greenhouse gases is substantial. But so is the potential for creating greenhouse gas (GHG) liabilities, the unintentional increase in one or more GHGs by activities that mitigate another. Whole-system accounting provides a means for including all GHG-contributing processes in the same cropping system analysis in order to illuminate major liabilities and synergies. We contrast a field crop system in the upper U.S. midwest with a similar system in tropical India, and provide evidence that N2O flux - the major contributor to radiative forcing in both row-crop systems - can be abated with little loss of crop productivity.

  5. Quasi-QSAR for mutagenic potential of multi-walled carbon-nanotubes.

    PubMed

    Toropov, Andrey A; Toropova, Alla P

    2015-04-01

    Available on the Internet, the CORAL software (http://www.insilico.eu/coral) has been used to build up quasi-quantitative structure-activity relationships (quasi-QSAR) for prediction of mutagenic potential of multi-walled carbon-nanotubes (MWCNTs). In contrast with the previous models built up by CORAL which were based on representation of the molecular structure by simplified molecular input-line entry system (SMILES) the quasi-QSARs based on the representation of conditions (not on the molecular structure) such as concentration, presence (absence) S9 mix, the using (or without the using) of preincubation were encoded by so-called quasi-SMILES. The statistical characteristics of these models (quasi-QSARs) for three random splits into the visible training set and test set and invisible validation set are the following: (i) split 1: n=13, r(2)=0.8037, q(2)=0.7260, s=0.033, F=45 (training set); n=5, r(2)=0.9102, s=0.071 (test set); n=6, r(2)=0.7627, s=0.044 (validation set); (ii) split 2: n=13, r(2)=0.6446, q(2)=0.4733, s=0.045, F=20 (training set); n=5, r(2)=0.6785, s=0.054 (test set); n=6, r(2)=0.9593, s=0.032 (validation set); and (iii) n=14, r(2)=0.8087, q(2)=0.6975, s=0.026, F=51 (training set); n=5, r(2)=0.9453, s=0.074 (test set); n=5, r(2)=0.8951, s=0.052 (validation set). PMID:25465947

  6. Zeta Potential of Carbonates in Saline Brines as a Function of NaCl Salinity and Potential Determining Ions: Ca, Mg and SO4

    NASA Astrophysics Data System (ADS)

    Al-Mahrouqi, D.; Vinogradov, J.; Jackson, M.

    2014-12-01

    Measurements of zeta potential are typically obtained using crushed samples and commercial zetameters at ionic strength <1M. However, many natural brines have much higher salinity. This study reports zeta potential values interpreted from streaming potential measurements in two intact carbonate rock samples as a function of brine salinity (up to 5M) and potential determining ions (PDIs: Ca, Mg, SO4). The two samples appear to be identical pure carbonates in XRD analysis but differ in age and provenance. For low salinity NaCl brines (<1M), in which the initial PDI concentration was established during pre-equilibration with the rock samples, the measured (negative) zeta potential decreased in magnitude with increasing NaCl concentration, consistent with published data and reflecting contraction of the electrical double layer. At higher NaCl salinity (>1M) the surface charge polarity was inverted for one rock sample, yet equilibrium Ca and Mg concentrations remained constant (c. 1.3x10-3 and 7x10-5M respectively) and similar for both samples, regardless of NaCl salinity. We suggest charge inversion was caused by differences in SO4 concentration (3x10-4 versus 1.2x10-3M) in the two samples after equilibration. At higher and externally controlled concentrations of Ca (0.1 - 0.42M), the zeta potential was less affected by NaCl salinity and pCa was the dominant control, although the role of SO4 in distinguishing between rock samples remained valid. The iso-electric point was different for the two samples (pCa 1.7 versus 0.5) and lower than any previously published values. Our results suggest that small differences in PDI concentration may invert surface charge polarity at high NaCl concentration; moreover, trace amounts of anhydrite or other minerals that yield aqueous SO4 can significantly modify surface charge in carbonates that otherwise appear identical. These results are important when interpreting the streaming component of SP measurements in carbonates.

  7. Potential Risks of Freshwater Aquifer Contamination from Carbon Capture and Storage

    NASA Astrophysics Data System (ADS)

    Little, M. G.; Jackson, R. B.

    2009-12-01

    Carbon Capture and Storage (CCS) represents a suite of technologies to separate, compress, transport and securely store CO2 produced from power plants and other industrial facilities. Currently, power plant flue gasses containing CO2 are released directly to the atmosphere where they contribute to the steady rise in atmospheric CO2 and thus climate change. The ultimate goal of CCS is to prevent this CO2 from reaching the atmosphere by securing it underground; however, a full understanding of the associated environmental risks is needed before large-scale implementation is feasible and generally accepted by the public. Deep saline aquifers hold the most promise for CCS, having long-term stability, the largest capacity in the U.S. and low leakage risk. Even so, levels of leakage acceptable for the prevention catastrophic climate change (<0.1 % annual leakage) may translate into tons of CO2 released from a given deep storage aquifer into intermediate and shallow strata. As freshwater aquifers used for drinking, industry and agriculture lie directly above many of the proposed CCS locations across the US and world, leaks may have the potential to negatively impact groundwater services. In this study, we access the potential risk of increasing heavy metal concentrations in shallower, drinking-water aquifers due to CO2 contamination. We have identified drinking-water aquifers with evidence of naturally occurring metals of health concern that overlie the most likely sites for CCS. Sediment samples from 4 aquifers that meet this criteria, Mahomet (Illinois), Ogallala (Texas), Columbia (Virginia) and Aquia (Maryland) have been subjected to an on-going, long-term CO2 contamination simulation. The simulated groundwater have been tested for a suite of elements (Cr, Mn, Ni, As, Se, Cd, Tl and Pb). Preliminary results show that CO2 can drive simulated groundwater concentrations of As and Cd to dangerous levels; however, these impacts are highly dependent on lithology. Preliminary

  8. Regional studies of potential carbon monoxide sources based on Space Shuttle and aircraft measurements

    NASA Technical Reports Server (NTRS)

    Newell, R. E.; Shipley, S. T.; Connors, V. S.; Reichle, H. G., Jr.

    1988-01-01

    Carbon monoxide measurements made from the space shuttle show maxima over South America, central Africa, the eastern Mediterranean, and China. The maxima appear to be associated with either concomitant or prior convection in the air masses which carries boundary layer air into the upper troposphere. Previous aircraft measurements of carbon monoxide and ozone over South America are shown to be consistent with this view. In the tropics the three regions of long-term mean rising motion, which form part of the Walker circulation, are associated with elevated carbon monoxide.

  9. Potential for in situ carbonation of peridotite for geological CO2 storage

    NASA Astrophysics Data System (ADS)

    Kelemen, P.; Matter, J.; Streit, L.; Rudge, J.; Spiegelman, M.

    2008-12-01

    The rate of natural carbonation of tectonically exposed mantle peridotite during weathering and low temperature alteration can probably be enhanced to develop a significant sink for atmospheric CO2. Formation of solid carbonate minerals in situ constitutes an important alternative that should be explored. It may be less costly than ex situ mineral carbonation involving transport of solid reactants, grinding, heat treatment, and reaction in pressurized vessels. It is certainly safer and much easier to monitor than storage of super-critical CO2 fluid in pore space at depth. Natural carbonation of peridotite in the Samail ophiolite, an uplifted slice of oceanic crust and upper mantle in the Sultanate of Oman, is surprisingly rapid. Carbonate veins in mantle peridotite in Oman have an average 14C age of approx 26,000 years, and are not 30 to 95 million years old as previously believed. These data and reconnaissance mapping show that 10,000 to 100,000 tons per year of atmospheric CO2 are converted to solid carbonate minerals via peridotite weathering in Oman [1]. Peridotite carbonation can be accelerated via drilling, hydraulic fracture, input of purified CO2 at elevated pressure, and - particularly - increased temperature at depth. Our simple 1D thermal models suggest that, after an initial heating step, CO2 injected at 25 or 30°C can be heated by exothermic carbonation reactions that sustain high temperature and rapid reaction rates at depth with little expenditure of energy. In situ carbonation of peridotite could consume more than 1 billion tons of CO2 per year in Oman alone, affording a low-cost, safe and permanent method to store atmospheric CO2 [1]. In the appropriate PTX regime, solid volume changes associated with peridotite carbonation may induce reaction driven cracking as well as exothermic heating. If cracks expose fresh, new surface area to sustain continued reaction, carbonation rates could accelerate over time. Alternatively, if cracking is too slow

  10. Heterogeneous Photocatalysis and Photoelectrocatalysis: From Unselective Abatement of Noxious Species to Selective Production of High-Value Chemicals.

    PubMed

    Augugliaro, Vincenzo; Camera-Roda, Giovanni; Loddo, Vittorio; Palmisano, Giovanni; Palmisano, Leonardo; Soria, Javier; Yurdakal, Sedat

    2015-05-21

    Heterogeneous photocatalysis and photoelectrocatalysis have been considered as oxidation technologies to abate unselectively noxious species. This article focuses instead on the utilization of these methods for selective syntheses of organic molecules. Some promising reactions have been reported in the presence of various TiO2 samples and the important role played by the amorphous phase has been discussed. The low solubility of most of the organic compounds in water limits the utilization of photocatalysis. Dimethyl carbonate has been proposed as an alternative green organic solvent. The recovery of the products by coupling photocatalysis with pervaporation membrane technology seems to be a solution for future industrial applications. As far as photoelectrocatalysis is concerned, a decrease in recombination of the photogenerated pairs occurs, enhancing the rate of the oxidation reactions and the quantum yield. Another benefit is to avoid reaction(s) between the intermediates and the substrate, as anodic and cathodic reactions take place in different places. PMID:26263277

  11. Synthesis of calcium carbonate nanocrystals and their potential application as vessels for drug delivery

    NASA Astrophysics Data System (ADS)

    Vergaro, Viviana; Carata, Elisabetta; Panzarini, Elisa; Baldassare, Francesca; Dini, Luciana; Ciccarella, Giuseppe

    2015-06-01

    Pure and stable calcium carbonate (CaCO3) nanocrystals were synthesized by spray drying method. We exploited the opportunity to use them as vessels for drug delivery studying the biocompatibility and the internalization in HeLa cells.

  12. QUANTITATIVE EVALUATION OF AIR FILTRATION SYSTEMS IN USE AT ASBESTOS ABATEMENT SITES: RESEARCH IN PROGRESS

    EPA Science Inventory

    High Efficiency Particulate Air (HEPA) filtration systems serve as the principal engineering control to remove asbestos particulate from airstreams at abatement projects. owever, little quantitative information is available on the integrity of these air filtration systems in prev...

  13. S. 1893: Asbestos School Hazard Abatement Reauthorization Act of 1989. Introduced in the Senate of the United States, One Hundredth First Congress, Second Session, November 16, 1989

    SciTech Connect

    Not Available

    1989-01-01

    The U.S. EPA has estimated that more than forty-four thousand school buildings contain friable asbestos, exposing millions of children and school employees to unwarranted health hazards. A bill, S.1893, has been introduced in the Senate of the United States to reauthorize the Asbestos School Hazard Abatement Act of 1984. The purposes of this Act are to direct the EPA to maintain a program to assist local schools in carrying out their responsibilities regarding asbestos; to provide assistance to state and local agencies to enable them to identify and abate asbestos health hazards; to provide financial assistance for training of persons involved with inspections of school buildings for asbestos; and to assure that no school employee suffers any disciplinary action as a result of calling attention to potential asbestos hazards which may exist in schools.

  14. Carbon Sequestration Potential in Stands under the Grain for Green Program in Southwest China

    PubMed Central

    Chen, Xiangang; Luo, Yunjian; Zhou, Yongfeng; Lu, Mei

    2016-01-01

    The Grain for Green Program (GGP) is the largest afforestation and reforestation project in China in the early part of this century. To assess carbon sequestration in stands under the GGP in Southwest China, the carbon stocks and their annual changes in the GGP stands in the region were estimated based on the following information: (1) collected data on the annually planted area of each tree species under the GGP in Southwest China from 1999 to 2010; (2) development of empirical growth curves and corresponding carbon estimation models for each species growing in the GPP stands; and (3) parameters associated with the stands such as wood density, biomass expansion factor, carbon fraction and the change rate of soil organic carbon content. Two forest management scenarios were examined: scenario A, with no harvesting, and scenario B, with logging at the customary rotation followed by replanting. The results showed that by the years 2020, 2030, 2040, 2050 and 2060, the expected carbon storage of the GGP stands in Southwest China is 139.58 TgC, 177.50–207.55 TgC, 196.86–259.65 TgC, 240.45–290.62 TgC and 203.22–310.03 TgC (T = 1012), respectively. For the same years, the expected annual change in carbon stocks is 7.96 TgCyr−1, −7.95–5.95 TgCyr−1, −0.10–4.67 TgCyr−1, 4.31–2.24 TgCyr−1 and −0.02–1.75 TgCyr−1, respectively. This indicates that the stands significantly contribute to forest carbon sinks in this region. In 2060, the estimated carbon stocks in the seven major species of GGP stands in Southwest China are 4.16–13.01 TgC for Pinus armandii, 6.30–15.01 TgC for Pinus massoniana, 11.51–13.44 TgC for Cryptomeria fortunei, 15.94–24.13 TgC for Cunninghamia lanceolata, 28.05 TgC for Cupressus spp., 5.32–15.63 TgC for Populus deltoides and 5.87–14.09 TgC for Eucalyptus spp. The carbon stocks in these seven species account for 36.8%–41.4% of the total carbon stocks in all GGP stands over the next 50 years. PMID:26959645

  15. Carbon Sequestration Potential in Stands under the Grain for Green Program in Southwest China.

    PubMed

    Chen, Xiangang; Luo, Yunjian; Zhou, Yongfeng; Lu, Mei

    2016-01-01

    The Grain for Green Program (GGP) is the largest afforestation and reforestation project in China in the early part of this century. To assess carbon sequestration in stands under the GGP in Southwest China, the carbon stocks and their annual changes in the GGP stands in the region were estimated based on the following information: (1) collected data on the annually planted area of each tree species under the GGP in Southwest China from 1999 to 2010; (2) development of empirical growth curves and corresponding carbon estimation models for each species growing in the GPP stands; and (3) parameters associated with the stands such as wood density, biomass expansion factor, carbon fraction and the change rate of soil organic carbon content. Two forest management scenarios were examined: scenario A, with no harvesting, and scenario B, with logging at the customary rotation followed by replanting. The results showed that by the years 2020, 2030, 2040, 2050 and 2060, the expected carbon storage of the GGP stands in Southwest China is 139.58 TgC, 177.50-207.55 TgC, 196.86-259.65 TgC, 240.45-290.62 TgC and 203.22-310.03 TgC (T = 1012), respectively. For the same years, the expected annual change in carbon stocks is 7.96 TgCyr-1, -7.95-5.95 TgCyr-1, -0.10-4.67 TgCyr-1, 4.31-2.24 TgCyr-1 and -0.02-1.75 TgCyr-1, respectively. This indicates that the stands significantly contribute to forest carbon sinks in this region. In 2060, the estimated carbon stocks in the seven major species of GGP stands in Southwest China are 4.16-13.01 TgC for Pinus armandii, 6.30-15.01 TgC for Pinus massoniana, 11.51-13.44 TgC for Cryptomeria fortunei, 15.94-24.13 TgC for Cunninghamia lanceolata, 28.05 TgC for Cupressus spp., 5.32-15.63 TgC for Populus deltoides and 5.87-14.09 TgC for Eucalyptus spp. The carbon stocks in these seven species account for 36.8%-41.4% of the total carbon stocks in all GGP stands over the next 50 years. PMID:26959645

  16. CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM CARBON DIOXIDE SEQUESTRATION

    SciTech Connect

    V. J. Fabry

    2003-10-30

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds or bioreactors to abate CO{sub 2} emissions from power plants.

  17. CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION

    SciTech Connect

    V.J. Fabry, Ph.D.

    2001-12-15

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

  18. CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION

    SciTech Connect

    V.J. Fabry

    2001-07-01

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids single-celled, marine algae that are the major global producers of calcium carbonate to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

  19. CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION

    SciTech Connect

    V.J. Fabry, Ph.D.

    2002-12-15

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

  20. CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION

    SciTech Connect

    V.J. Fabry, Ph.D.

    2002-07-09

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

  1. CALCIUM CARBONATE PRODUCTION BY COCCOLITHAPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION

    SciTech Connect

    V. J.Fabry

    2004-01-30

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

  2. CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION

    SciTech Connect

    V.J. Fabry, Ph.D.

    2001-09-10

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

  3. CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION

    SciTech Connect

    V.J. Fabry, Ph.D.

    2003-04-15

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

  4. CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION

    SciTech Connect

    V.J. Fabry, Ph.D.

    2003-07-15

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

  5. CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION

    SciTech Connect

    V.J. Fabry, Ph.D.

    2002-09-30

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

  6. Calcium Carbonate Produced by Coccolithophorid Algae in Long Term, Carbon Dioxide Sequestration

    SciTech Connect

    V.J. Fabry

    2007-06-30

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO2 through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids - single-celled, marine algae that are the major global producers of calcium carbonate - to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

  7. CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION

    SciTech Connect

    V. J. Fabry

    2005-01-24

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids ? single-celled, marine algae that are the major global producers of calcium carbonate ? to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

  8. Calcium Carbonate Production by Coccolithophorid Algae in Long Term, Carbon Dioxide Sequestration

    SciTech Connect

    V.J. Fabry

    2005-04-29

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

  9. CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION

    SciTech Connect

    V.J. Fabry

    2004-04-26

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids single-celled, marine algae that are the major global producers of calcium carbonate to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

  10. CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION

    SciTech Connect

    V.J. Fabry

    2004-10-30

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds or bioreactors to abate CO{sub 2} emissions from power plants.

  11. Calcium Carbonate Production by Coccolithophorid Alge in Long Term Carbon Dioxide Sequestration

    SciTech Connect

    V. J. Fabry

    2006-09-30

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

  12. Calcium Carbonate Production by Coccolithophorid Algae in Long Term, Carbon Dioxide Sequestration

    SciTech Connect

    V. J. Fabry

    2006-06-30

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO{sub 2} through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are the major global producers of calcium carbonate--to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

  13. Terrestrial Carbon Sequestration with Biochar: A Preliminary Assessment of its Global Potential

    NASA Astrophysics Data System (ADS)

    Amonette, J.; Lehmann, J.; Joseph, S.

    2007-12-01

    Biochar technology involves the capture of CO2 from the atmosphere by photosynthesis and its ultimate conversion to biochar by pyrolysis. Energy is obtained during the pyrolysis process and the charcoal, or biochar, which is considerably more stable than biomass, may then be incorporated into agricultural lands where it serves to increase the nutrient- and water-holding capacity of soil. With an estimated half-life in soil on the order of centuries to millenia, biochar offers a way of safely storing C for long periods of time while enhancing the productivity of terrestrial ecosystems. Moreover, biochar technology, like other biomass conversion approaches that include C sequestration options, offers a way to decrease the levels of CO2 in the atmosphere. That is, biochar technology is one of the few inherently "carbon-negative" sources of energy. These positive attributes are of little consequence, however, if the total contribution to sequestration is small compared to the need. In this paper, we provide a preliminary assessment of the potential contribution of biochar technology to the mitigation of climate change, and identify some research needs. Currently, the atmospheric C levels are increasing by about 4.1 Gt/yr, with 7.2 Gt/yr being put into the atmosphere by fossil fuel combustion and cement production, and 3.1 Gt/yr being removed from the atmosphere by the ocean (2.2 Gt/yr) and terrestrial processes (0.9 Gt/yr). The uptake by terrestrial processes can be increased significantly by management of the 60.6 Gt/yr of biomass C that is fixed by photosynthesis (i.e., net primary productivity), of which 59 Gt/yr is decomposed and 1.6 Gt/yr combusted. Biomass pyrolysis converts about 50% of the biomass C to char. Of the other 50% that is converted to bio-oil and bio-gas, the net energy production is about 62% efficient. Thus, pyrolysis of 1 Gt of biomass C would provide energy equivalent to about 0.3 Gt of fossil C and could be used to offset that amount of fossil C

  14. High-Pressure Orthorhombic Ferromagnesite as a Potential Deep-Mantle Carbon Carrier

    PubMed Central

    Liu, Jin; Lin, Jung-Fu; Prakapenka, Vitali B.

    2015-01-01

    Knowledge of the physical and chemical properties of candidate deep-carbon carriers such as ferromagnesite [(Mg,Fe)CO3] at high pressure and temperature of the deep mantle is necessary for our understanding of deep-carbon storage as well as the global carbon cycle of the planet. Previous studies have reported very different scenarios for the (Mg,Fe)CO3 system at deep-mantle conditions including the chemical dissociation to (Mg,Fe)O+CO2, the occurrence of the tetrahedrally-coordinated carbonates based on CO4 structural units, and various high-pressure phase transitions. Here we have studied the phase stability and compressional behavior of (Mg,Fe)CO3 carbonates up to relevant lower-mantle conditions of approximately 120 GPa and 2400 K. Our experimental results show that the rhombohedral siderite (Phase I) transforms to an orthorhombic phase (Phase II with Pmm2 space group) at approximately 50 GPa and 1400 K. The structural transition is likely driven by the spin transition of iron accompanied by a volume collapse in the Fe-rich (Mg,Fe)CO3 phases; the spin transition stabilizes the high-pressure phase II at much lower pressure conditions than its Mg-rich counterpart. It is conceivable that the low-spin ferromagnesite phase II becomes a major deep-carbon carrier at the deeper parts of the lower mantle below 1900 km in depth. PMID:25560542

  15. High-pressure orthorhombic ferromagnesite as a potential deep-mantle carbon carrier

    DOE PAGESBeta

    Liu, Jin; Lin, Jung -Fu; Prakapenka, Vitali B.

    2015-01-06

    In this study, knowledge of the physical and chemical properties of candidate deep-carbon carriers such as ferromagnesite [(Mg,Fe)CO3] at high pressure and temperature of the deep mantle is necessary for our understanding of deep-carbon storage as well as the global carbon cycle of the planet. Previous studies have reported very different scenarios for the (Mg,Fe)CO3 system at deep-mantle conditions including the chemical dissociation to (Mg,Fe)O+CO2, the occurrence of the tetrahedrally-coordinated carbonates based on CO4 structural units, and various high-pressure phase transitions. Here we have studied the phase stability and compressional behavior of (Mg,Fe)CO3 carbonates up to relevant lower-mantle conditions ofmore » approximately 120 GPa and 2400 K. Our experimental results show that the rhombohedral siderite (Phase I) transforms to an orthorhombic phase (Phase II with Pmm2 space group) at approximately 50 GPa and 1400 K. The structural transition is likely driven by the spin transition of iron accompanied by a volume collapse in the Fe-rich (Mg,Fe)CO3 phases; the spin transition stabilizes the high-pressure phase II at much lower pressure conditions than its Mg-rich counterpart. It is conceivable that the low-spin ferromagnesite phase II becomes a major deep-carbon carrier at the deeper parts of the lower mantle below 1900 km in depth.« less

  16. Potential contaminant transport in the regional Carbonate Aquifer beneath Yucca Mountain, Nevada, USA

    NASA Astrophysics Data System (ADS)

    Bredehoeft, John; King, Michael

    2010-05-01

    Yucca Mountain, Nevada is the site of the proposed US geologic repository for spent nuclear fuel and high-level radioactive waste. The repository is to be a mine, sited approximately 300 m below the crest of the mountain, in a sequence of variably welded and fractured mid-Miocene rhylolite tuffs, in the unsaturated zone, approximately 300 m above the water table. Beneath the proposed repository, at a depth of 2 km, is a thick sequence of Paleozoic carbonate rocks that contain the highly transmissive Lower Carbonate Aquifer. In the area of Yucca Mountain the Carbonate Aquifer integrates groundwater flow from north of the mountain, through the Amargosa Valley, through the Funeral Mountains to Furnace Creek in Death Valley, California where the groundwater discharges in a set of large springs. Data that describe the Carbonate Aquifer suggest a concept for flow through the aquifer, and based upon the conceptual model, a one-layer numerical model was constructed to simulate groundwater flow in the Carbonate Aquifer. Advective transport analyses suggest that the predicted travel time of a particle from Yucca Mountain to Death Valley through the Carbonate Aquifer might be as short as 100 years to as long 2,000 years, depending upon the porosity.

  17. The microwave assisted synthesis of 1-alkyl-3-methylimidazolium bromide as potential corrosion inhibitor toward carbon steel in 1 M HCl solution saturated with carbon dioxide

    SciTech Connect

    Pasasa, Norman Vincent A. Bundjali, Bunbun; Wahyuningrum, Deana

    2015-09-30

    Injection of corrosion inhibitor into the fluid current of oil and gas pipelines is an effective way to mitigate corrosion rate on the inner-surface parts of pipelines, especially carbon steel pipelines. In this research, two alkylimidazolium ionic liquids, 1-decyl-3-methylimidazolium bromide (IL1) and 1-dodecyl-3-methylimidazolium bromide (IL2) have been synthesized and studied as a potential corrosion inhibitor towards carbon steel in 1 M HCl solution saturated with carbon dioxide. IL1 and IL2 were synthesized using microwave assisted organic synthesis (MAOS) method. Mass Spectrometry analysis of IL1 and IL2 showed molecular mass [M-H+] peak at 223.2166 and 251.2484, respectively. The FTIR,{sup 1}H-NMR and {sup 13}C-NMR spectra confirmed that IL1 and IL2 were successfully synthesized. Corrosion inhibition activity of IL1 and IL2 were determined using weight loss method. The results showed that IL1 and IL2 have the potential as good corrosion inhibitors with corrosion inhibition efficiency of IL1 and IL2 are 96.00% at 100 ppm (343 K) and 95.60% at 50 ppm (343 K), respectively. The increase in the concentration of IL1 and IL2 tends to improve their corrosion inhibition activities. Analysis of the data obtained from the weight loss method shows that the adsorption of IL1 and IL2 on carbon steel is classified into chemisorption which obeys Langmuir’s adsorption isotherm.

  18. An Analysis of the Climate Change Mitigation Potential through Soil Organic Carbon Sequestration in a Corn Belt Watershed

    NASA Astrophysics Data System (ADS)

    Bhattarai, M. D.; Secchi, S.; Schoof, J. T.

    2015-12-01

    The sequestration of carbon constitutes one of major options in agricultural climate change land-based mitigation. We examined the carbon sequestration potential of alternative agricultural land uses in an intensively farmed Corn Belt watershed. We Used downscaled data from eight atmosphere-ocean general circulation models (AOGCMs) for a simulation period between 2015 and 2099 with three emission pathways reflecting low, medium and high greenhouse gas scenarios. The use of downscaled data, coupled with high resolution land use and soil data, can help policy makers and land managers better understand spatial and temporal impacts of climate change. We consider traditional practices such as no-till corn-soybean rotations and continuous corn and include also switchgrass, a bioenergy crop. Our results show that switching from conventional tillage continuous corn to no-till corn-soybean can sequester the equivalent of 156,000 MtCO2 of soil organic carbon with a sequestration rate of 2.38 MtCO2 ha-1 yr-1 for the simulated period. Our results also indicate that switchgrass can sequester the equivalent of 282,000 MtCO2 of soil organic carbon with a sequestration rate of 4.4 MtCO2 ha-1 yr-1 for the period. Our finding also suggests that while climate change impacts corn and soybean yields, it does not have a significant effect on switchgrass yields possibly due to carbon fertilization effect on switchgrass yields.

  19. Diurnal and seasonal carbon sequestration potential of seven broadleaved species in a mixed deciduous forest in India

    NASA Astrophysics Data System (ADS)

    Biswas, Soumyajit; Bala, Sanjay; Mazumdar, Asis

    2014-06-01

    The objective of the study was to measure annual carbon sequestration rate of mixed deciduous forest by measuring that of seven young broadleaved tree species (6 years age) as well as selection of better carbon sequestered plant species for future plantation. The diurnal net assimilation rate of Carbon dioxide (CO2) at leaf level was measured with LI-6400 Portable Photosynthesis System at daytime on seasonal basis in a man-made forest at Budge Budge (N 22°28‧ E 88°08‧) of South 24 Parganas, West Bengal, INDIA. Net assimilation rate of carbon at canopy level was calculated by measuring Leaf Area Index with LAI-2200 and using analytical model with non-rectangular hyperbolic light response curve. The average net assimilation rate of CO2 at leaf level was found maximum in Albizzia lebbek (8.13 μmol m-2 s-1) and that of canopy level in Eucalyptus spp. (4.851 g h-1). The minimum was found for Swietenia mahagoni (1.058 g h-1). The annual carbon sequestration rate of the mixed forest in natural condition was estimated 6.01 t ha-1 year-1 by consolidating the potential of all seven species.

  20. Effects of Extensive Beetle-Induced Forest Mortality on Aromatic Organic Carbon Loading and Disinfection Byproduct Formation Potential

    NASA Astrophysics Data System (ADS)

    Brouillard, B.; Mikkelson, K. M.; Dickenson, E.; Sharp, J.

    2015-12-01

    Recent drought and warmer temperatures associated with climate change have caused increased pest-induced forest mortality with impacts on biogeochemical and hydrologic processes. To better understand the seasonal impacts of bark beetle infestation on water quality, samples were collected regularly over two overlapping snow free seasons at surface water intakes of six water treatment facilities in the Rocky Mountain region of Colorado displaying varying levels of bark beetle infestation (high >40%, moderate 20-40%, and low <20%). Organic carbon concentrations were typically 3 to 6 times higher in waters sourced from high beetle-impacted watersheds compared to moderate and low impact watersheds, revealing elevated specific ultraviolet absorbance, fluorescence, and humic-like intensity indicative of elevated aromatic carbon signatures. Accordingly, an increase in disinfection byproduct (DBP) formation potential of 400 to 600% was quantified when contrasted with watersheds containing less tree mortality. Beetle impact exasperated seasonal increases in carbon loading and DBP formation potential following both runoff and precipitation events indicating windows when enhanced water treatment may be utilized by water providers in highly infested regions. Additionally, elevated carbon concentrations throughout the summer and fall along with peaks following precipitation events provide evidence of shifting hydrologic flow paths in areas experiencing high forest mortality from decreased tree water uptake and interception. Collectively, these results demonstrate the need for continued watershed protection and monitoring with a changing climate as the resultant perturbations can have adverse effects on biogeochemistry and water quality in heavily impacted areas.

  1. Risk management for sulfur dioxide abatement under multiple uncertainties

    NASA Astrophysics Data System (ADS)

    Dai, C.; Sun, W.; Tan, Q.; Liu, Y.; Lu, W. T.; Guo, H. C.

    2016-03-01

    In this study, interval-parameter programming, two-stage stochastic programming (TSP), and conditional value-at-risk (CVaR) were incorporated into a general optimization framework, leading to an interval-parameter CVaR-based two-stage programming (ICTP) method. The ICTP method had several advantages: (i) its objective function simultaneously took expected cost and risk cost into consideration, and also used discrete random variables and discrete intervals to reflect uncertain properties; (ii) it quantitatively evaluated the right tail of distributions of random variables which could better calculate the risk of violated environmental standards; (iii) it was useful for helping decision makers to analyze the trade-offs between cost and risk; and (iv) it was effective to penalize the second-stage costs, as well as to capture the notion of risk in stochastic programming. The developed model was applied to sulfur dioxide abatement in an air quality management system. The results indicated that the ICTP method could be used for generating a series of air quality management schemes under different risk-aversion levels, for identifying desired air quality management strategies for decision makers, and for considering a proper balance between system economy and environmental quality.

  2. Scope for active noise abatement in vehicle diesel engines

    NASA Astrophysics Data System (ADS)

    Summerauer, I.; Boesch, N.

    1984-04-01

    Noise reduction measures must be directed to the engine, the exhaust system, and the cooling system (fan) all of which contribute approximately 90% of the sound energy emitted from commercial diesel trucks. The noise generation processes were visualized and limiting conditions fixed by law were considered in establishing criteria for active solar noise abatement measures. A more effective silencer and better vibration damping on the surface of the silencer and exhaust pipes can reduce noise from the exhaust system. Acoustic emission generated by the fan and air flow can be reduced by decreasing flow velocity or by turning on the fan only when a full cooling output is required (10% of the time). Active measures are needed on the engine itself either at the point of the solid-borne sound transmission or at the point of the solid-borne vibrations. The predominant effect is on the engine casing; oil sump; air suction pipe or air charge line; the flywheel casing; and the clutch housing.

  3. Optimized combinations of abatement strategies for urban mobile sources.

    PubMed

    Yu, T Y; Lin, Y C; Chang, L F

    2000-08-01

    The maximum incremental reactivity (MIR) scale was chosen as a practical index for quantifying ozone-forming impacts. The integer linear and nonlinear programming techniques were employed as the optimization method to maximize MIR and volatile organic compound (VOC) reductions, and minimize ozone's marginal cost with varied control costs. Mobile vehicles were divided into nine categories according to the demands of decision makers and the distinctive features of local circumstance in metro-Taipei. The emission factor (EF) and vehicle kilometers traveled (VKT) of each kind of vehicle were estimated by MOBILE5B model via native parameters and questionnaires. Compressed natural gas (CNG) and inspection and maintenance (I/M) were the alternative control programs for buses and touring buses; liquefied petroleum gas (LPG), I/M, methanol, electrical vehicle (EV) were for taxis and low duty gasoline vehicles. EV, methanol, and I/M were the possible control methods for two-stroke and four-stroke engine motorcycles; I/M programs for low-duty diesel trucks, heavy-duty diesel trucks, and low-duty gasoline trucks. The results include the emission ratios of specific vehicle to all vehicles, the best combination of abated measures based on different objectives, and the marginal cost for ozone and VOC with varied control costs. PMID:11057602

  4. Abatement of gaseous and particulate contamination in a space instrument

    NASA Technical Reports Server (NTRS)

    Scialdone, J. J.

    1983-01-01

    Methods to prevent the ingestion of external contaminants into the instrument and to limit the effect of the self-generated contaminants during ground, launch, orbiting and landing phases of flight were investigated. It is proposed that a positive pressure and purging flow of clean gas inside the instrument be maintained while on the ground, during launch, and for a period of time in orbit. The pressure to be maintained and the required purging flow are examined in terms of the effectiveness in preventing gaseous and particulate contaminants ingestion and the abatement of the self-generated contaminants. Considerations have been given to the venting requirements for the structural integrity of the instrument during launch, the limitations on the volume and the pressure of the purging gas to be carried along in orbit, and the required venting area is established based on the internal volume of the instrument, the allowable pressure differential, and the rate of external pressure change during launch. Previously announced in STAR as N83-23350

  5. Yale FICSIT: risk factor abatement strategy for fall prevention.

    PubMed

    Tinetti, M E; Baker, D I; Garrett, P A; Gottschalk, M; Koch, M L; Horwitz, R I

    1993-03-01

    Based on finding a strong association between number of impairments and risk of falling in earlier studies, Yale FICSIT investigators are conducting an intervention trial comparing the effectiveness of usual care plus social visits (SV) and a targeted risk abatement intervention (TI) strategy in reducing falls among at risk community elderly persons. Subjects include members of a participating HMO who are > or = 70 years of age, cognitively intact, not terminally ill, not too physically active, and possess at least one fall risk factor. The targeted risk factors include postural hypotension; sedative use; at least four targeted medications; upper and lower extremity strength and range of motion impairments; foot problems; and balance, gait, and transfer dysfunctions. The interventions include medication adjustments, behavioral change recommendations, education and training, and home-based exercise regimens targeting the identified risk factors. The interventions are carried out by the study nurse practitioner and physical therapist in TI subjects' homes. The SV subjects receive a comparable number of home visits as the TI subjects during which a structured life review is performed by social work students. The primary outcome is occurrence of falls during the 12-month followup. Secondary outcomes include change in mobility performance and fall-related efficacy. PMID:8440856

  6. The schoolroom asbestos abatement program: a public policy debacle

    NASA Astrophysics Data System (ADS)

    Ross, M.

    1995-10-01

    It is estimated that nearly 100 billion has been spent on removal of asbestos-bearing materials from schoolrooms, public and commercial buildings, and homes. This removal continues to this day despite the publication of an advisory document in 1990 by the US Environmental Protection Agency that states most removal is unnecessary and is even counterproductive both in terms health protection and costs. Concern over low exposure to substances that are designated as carcinogens is based on the false concept that even the smallest exposure to such substances can increase cancer risk. The expression “one molecule of a chemical or one asbestos fiber can possibly produce a tumor” is repeated over and over until it is accepted as a truth. Over 1400 air samples taken in 219 North American school buildings show the average fiber level to be 0.00022 fibers per milliliter of air. Using the most pessimistic models and attendance in the school for 6 h a day, five days a week, for 14 years, the calculated risk is one excess cancer death per million lifetimes. In contrast, the risk of dying from a lightning strike is 35 deaths per million lifetimes. Ambient air asbestos concentrations measured in the chrysotile asbestos mining towns of Quebec are 220 to 2200 times greater than that measured in the average schoolroom, yet the women living their entire lives in these towns show no increased cancer risk. The asbestos abatement program in the United States is a public policy debacle.

  7. Abatement of malodorants from pesticide factory in dielectric barrier discharges.

    PubMed

    Chen, Jie; Yang, Jiantao; Pan, Hua; Su, Qingfa; Liu, Yamin; Shi, Yao

    2010-05-15

    Traditional odor control methods are limitative technically and economically for the abatement of odor from pesticide factory due to its toxicity and complicated composition. Non-thermal plasma (NTP) methods, typically characterized by high removal efficiency, energy yields and good economy, offer possible alternative solutions. This paper provides laboratory scale experimental data on the removal of simulated odors from pesticide factory with various humidity (0-0.8 vol%) and oxygen contents (0-21%) by a dielectric barrier discharge (DBD) reactor. Peak voltage and initial dimethylamine (DML) concentration are important factors that influence the DML removal efficiency and energy yield. The conversion of DML of 761 mg/m(3) reaches 100% at a peak voltage of 41.25 kV. Under the experiment conditions, the conversion of DML increases with an increase of oxygen contents. And the highest DML conversion was achieved with the gas stream containing 0.3% water. Simultaneously, the concentration of O(3) and OH radical in reactor was measured. Higher conversion, higher energy yield and fewer byproducts were found in mixed odor (DML+dimethyl sulfide (DMS)) treatment than that in single odor treatment. The energy yield is promoted from 2.13 to 5.20mg/kJ. PMID:20116170

  8. Insights into the Carbon Sequestration Potential of Rangelands Through Measurement and Modeling of Differently Managed Pastures

    NASA Astrophysics Data System (ADS)

    Owen, J. J.; Hartman, M.; Parton, W. J.; Silver, W. L.

    2014-12-01

    Poor management of rangelands has led to significant soil organic matter losses globally, and contributed to increasing atmospheric CO2 concentrations. Restoring and increasing soil carbon (C) content in rangelands offers an opportunity to mitigate climate change while improving soil conditions and increasing forage production. Organic matter amendments are used to improve soil properties, but predicting the resulting changes in soil C is challenging due to the interactions between amendment characteristics, climate, and soil characteristics. We used data from 10 pasture-based dairies in California and the DayCent model to test the impact of long-term (>30 year) manure additions on soil C pools and fluxes. Soils were sampled from 26 fields which had solid, liquid, solid and liquid, or no manure additions. These field data and management information provided by the ranchers were used to model the effects of manure amends on soil C storage and loss. Soil C was significantly greater in manured fields than non-manured fields when corrected for clay content and slope. Fields with higher clay had more soil C, as did those with lower slopes, and these effects were large enough to confound the manuring effect. DayCent was able to accurately estimate total soil C when parameterized with field-specific management practices, averaging only a 10±1% difference between measurement and modeled values. Using generalized management histories for manured and non-manured fields, as would be used for regional-scale estimates, produced less accurate results with a 24±3% average difference between measurement and modeled values. Modeling alternate scenarios for each field suggested that manure amendment increased soil C and forage production by 0.6 Mg ha-1 y-1 and 0.3 Mg ha-1 y-1, respectively. Forecasting to 2100 showed that in manure-amended fields, soil C increased until 2080 before stabilization, mostly through gains in the pool with slow turnover. The "passive soil C" pool

  9. Low-cost household paint abatement to reduce children's blood lead levels

    SciTech Connect

    Taha, T.; Kanarek, M.S.; Schultz, B.D.; Murphy, A.

    1999-11-01

    The purpose was to examine the effectiveness of low-cost abatement on children's blood lead levels. Blood lead was analyzed before and after abatement in 37 homes of children under 7 years old with initial blood lead levels of 25--44 {micro}g/dL. Ninety-five percent of homes were built before 1950. Abatement methods used were wet-scraping and repainting deteriorated surfaces and wrapping window wells with aluminum or vinyl. A control group was retrospectively selected. Control children were under 7 years old, had initial blood lead levels of 25--44 {micro}g/dL and a follow-up level at least 28 days afterward, and did not have abatements performed in their homes between blood lead levels. After abatement, statistically significant declines occurred in the intervention children's blood lead levels. The mean decline was 22%, 1 to 6 months after treatment. After adjustment for seasonality and child's age, the mean decline was 6.0 {micro}g/dL, or 18%. The control children's blood levels did not decline significantly. There was a mean decline of 0.25 {micro}g/dL, or 0.39%. After adjustment for seasonality and age, the mean decline for control children was 1.6 {micro}g/dL, or 1.8%. Low-cost abatement and education are