WorldWideScience

Sample records for carbon 21

  1. 21 CFR 582.1240 - Carbon dioxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is...

  2. 21 CFR 868.5310 - Carbon dioxide absorber.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in...

  3. 21 CFR 184.1240 - Carbon dioxide.

    Science.gov (United States)

    2010-04-01

    .... The solid form, dry ice, sublimes under atmospheric pressure at a temperature of −78.5 °C. Carbon dioxide is prepared as a byproduct of the manufacture of lime during the “burning” of limestone, from the... processing aid as defined in § 170.3(o)(24) of this chapter; and a propellant, aerating agent, and gas...

  4. 40 CFR 721.10100 - Dialkyl dimethyl ammonium carbonate (2:1) (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Dialkyl dimethyl ammonium carbonate (2... Specific Chemical Substances § 721.10100 Dialkyl dimethyl ammonium carbonate (2:1) (generic). (a) Chemical... as dialkyl dimethyl ammonium carbonate (2:1) (PMN P-03-716) is subject to reporting under...

  5. 21 CFR 878.3500 - Polytetrafluoroethylene with carbon fibers composite implant material.

    Science.gov (United States)

    2010-04-01

    ... Prosthetic Devices § 878.3500 Polytetrafluoroethylene with carbon fibers composite implant material. (a) Identification. A polytetrafluoroethylene with carbon fibers composite implant material is a porous device... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Polytetrafluoroethylene with carbon...

  6. Carbon monoxide: The 21st century poison that goes unnoticed

    International Nuclear Information System (INIS)

    This editorial article describes the effects of carbon monoxide poisoning on human beings and the mechanisms involving carbon monoxide saturation of haemoglobin that are responsible for it. The initial research done in the mid-1800s by Claude Bernard is presented. Methods of treatment for persons poisoned by carbon monoxide are discussed and the experiments made by J.B.S. Haldane on himself by breathing in carbon monoxide are described. Acclimatisation effects observed by Haldane and his co-workers and concerning persons occupationally exposed to carbon monoxide emissions are described

  7. Prediction of carbon exchanges between China terrestrial ecosystem and atmosphere in 21st century

    Institute of Scientific and Technical Information of China (English)

    JI JinJun; HUANG Mei; LI KeRang

    2008-01-01

    The projected changes in carbon exchange between China terrestrial ecosystem and the atmosphere and vegetation and soil carbon storage during the 21st century were investigated using an atmos-phere-vegetation interaction model (AVIM2). The results show that in the coming 100 a, for SRES B2 scenario and constant atmospheric CO2 concentration, the net primary productivity (NPP) of terrestrial ecosystem in China will be decreased slowly, and vegetation and soil carbon storage as well as net ecosystem productivity (NEP) will also be decreased. The carbon sink for China terrestrial ecosystem in the beginning of the 20th century will become totally a carbon source by the year of 2020, while for B2 scenario and changing atmospheric CO2 concentration, NPP for China will increase continuously from 2.94 GtC.a-1 by the end of the 20th century to 3.99 GtC.a-1 by the end of the 21st century, and vegetation and soil carbon storage will increase to 110.3 GtC. NEP in China will keep rising during the first and middle periods of the 21st century, and reach the peak around 2050s, then will decrease gradually and approach to zero by the end of the 21st century.

  8. Prediction of carbon exchanges between China terrestrial ecosystem and atmosphere in 21st century

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The projected changes in carbon exchange between China terrestrial ecosystem and the atmosphere and vegetation and soil carbon storage during the 21st century were investigated using an atmos-phere-vegetation interaction model (AVIM2). The results show that in the coming 100 a, for SRES B2 scenario and constant atmospheric CO2 concentration, the net primary productivity (NPP) of terrestrial ecosystem in China will be decreased slowly, and vegetation and soil carbon storage as well as net ecosystem productivity (NEP) will also be decreased. The carbon sink for China terrestrial ecosystem in the beginning of the 20th century will become totally a carbon source by the year of 2020, while for B2 scenario and changing atmospheric CO2 concentration, NPP for China will increase continuously from 2.94 GtC·a?1 by the end of the 20th century to 3.99 GtC·a?1 by the end of the 21st century, and vegetation and soil carbon storage will increase to 110.3 GtC. NEP in China will keep rising during the first and middle periods of the 21st century, and reach the peak around 2050s, then will decrease gradually and approach to zero by the end of the 21st century.

  9. 21 CFR 862.1160 - Bicarbonate/carbon dioxide test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bicarbonate/carbon dioxide test system. 862.1160 Section 862.1160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry...

  10. Importance of Nitrogen Availability on Land Carbon Sequestration in Northern Eurasia during the 21st Century

    Science.gov (United States)

    Kicklighter, D. W.; Melillo, J. M.; Monier, E.; Sokolov, A. P.; Lu, X.; Zhuang, Q.

    2015-12-01

    Atmospheric nitrogen deposition, nitrogen fixation, and the application of nitrogen fertilizers provide subsidies to land ecosystems that can increase nitrogen availability for vegetation production and thereby influence land carbon dynamics. In addition, enhanced decomposition of soil organic matter (SOM) from warming soils and permafrost degradation may also increase nitrogen availability in Northern Eurasia. Here, we examine how changes in nitrogen availability may influence land carbon dynamics in Northern Eurasia during the 21st century by comparing results for a "business as usual" scenario (the IPCC Representative Concentration Pathways or RCP 8.5) and a stabilization scenario (RCP 4.5) between a version of the Terrestrial Ecosystem Model that does not consider the effects of atmospheric nitrogen deposition, nitrogen fixation and soil thermal dynamics on land carbon dynamics (TEM 4.4) and a version that does consider these dynamics (TEM 6.0). In these simulations, atmospheric nitrogen deposition, nitrogen fixation, and fertilizer applications provide an additional 3.3 Pg N (RCP 4.5) to 3.9 Pg N (RCP 8.5) to Northern Eurasian ecosystems over the 21st century. Land ecosystems retain about 38% (RCP4.5) to 48% (RCP 8.5) of this nitrogen subsidy. Net nitrogen mineralization estimated by TEM 6.0 provide an additional 1.0 Pg N to vegetation than estimated by TEM 4.4 over the 21st century from enhanced decomposition of SOM including SOM formerly protected by permafrost. The enhanced nitrogen availability in TEM 6.0 allows Northern Eurasian ecosystems to sequester 1.8x (RCP 8.5) to 2.4x (RCP 4.5) more carbon over the 21st century than estimated by TEM 4.4. Our results indicate that consideration of nitrogen subsidies and soil thermal dynamics have a large influence on how simulated land carbon dynamics in Northern Eurasia will respond to future changes in climate, atmospheric chemistry, and disturbances.

  11. Enhanced Australian carbon sink despite increased wildfire during the 21st century

    International Nuclear Information System (INIS)

    Climate projections show Australia becoming significantly warmer during the 21st century, and precipitation decreasing over much of the continent. Such changes are conventionally considered to increase wildfire risk. Nevertheless, we show that burnt area increases in southern Australia, but decreases in northern Australia. Overall the projected increase in fire is small (0.72–1.31% of land area, depending on the climate scenario used), and does not cause a decrease in carbon storage. In fact, carbon storage increases by 3.7–5.6 Pg C (depending on the climate scenario used). Using a process-based model of vegetation dynamics, vegetation–fire interactions and carbon cycling, we show increased fire promotes a shift to more fire-adapted trees in wooded areas and their encroachment into grasslands, with an overall increase in forested area of 3.9–11.9%. Both changes increase carbon uptake and storage. The increase in woody vegetation increases the amount of coarse litter, which decays more slowly than fine litter hence leading to a relative reduction in overall heterotrophic respiration, further reducing carbon losses. Direct CO2 effects increase woody cover, water-use efficiency and productivity, such that carbon storage is increased by 8.5–14.8 Pg C compared to simulations in which CO2 is held constant at modern values. CO2 effects tend to increase burnt area, fire fluxes and therefore carbon losses in arid areas, but increase vegetation density and reduce burnt area in wooded areas. (letter)

  12. Response of plankton ecology and the carbon cycle to climate change over the 21st century

    Science.gov (United States)

    Marinov, I.; Doney, S.; Lima, I.; Lindsey, K.; Moore, K.

    2008-12-01

    Here we analyze the impact of climate change on ocean plankton ecology and the carbon cycle over the 21st century using a multi-decadal (1880-2100) experiment conducted with the latest version of the Community Climate System Model (CCSM-3.1) coupled ocean-atmosphere-land-ice model. The oceanic ecosystem model component includes three classes of phytoplankton (diatoms, pico/nano plankton, diazotrophs) and one class of zooplankton which grazes differentially on the phytoplankton groups. The competition between phytoplankton groups is altered by climate-induced changes in nutrients, light and zooplankton. Here we connect the resulting changes in the ecosystem structure to changes in the air-sea CO2 fluxes and the global ocean sink. Long-term trends due to anthropogenic changes are compared to the natural variability of the system. Increasing stratification in the northern hemisphere oceans decreases the nutrient supply to the ocean surface and decreases the relative and absolute diatom abundance. The northern hemisphere shift from diatoms to small phytoplankton results in decreases in total primary production, export production and export ratio, and a shift to a more efficiently recycled, lower biomass euphotic layer. By contrast, an increase in Southern Ocean westerlies acts against increasing temperature and freshwater flux to destratify the water-column. Additionally, the wind-driven poleward shift in the Southern Ocean subpolar-subtropical front results in a southward shift and increase in the largest oceanic diatom bloom. In the Southern Ocean diatoms are favored over small phytoplankton on average, acting to increase total chlorophyll, primary production and export production. The impact of these ecological shifts on the global oceanic carbon sink is complex, with northern and southern hemisphere effects partially compensating each other. In the net, total chlorophyll, primary and export production decrease, but less than previous modeling studies have suggested

  13. Modeling biomass burning and related carbon emissions during the 21st century in Europe

    KAUST Repository

    Migliavacca, Mirco

    2013-12-01

    In this study we present an assessment of the impact of future climate change on total fire probability, burned area, and carbon (C) emissions from fires in Europe. The analysis was performed with the Community Land Model (CLM) extended with a prognostic treatment of fires that was specifically refined and optimized for application over Europe. Simulations over the 21st century are forced by five different high-resolution Regional Climate Models under the Special Report on Emissions Scenarios A1B. Both original and bias-corrected meteorological forcings is used. Results show that the simulated C emissions over the present period are improved by using bias corrected meteorological forcing, with a reduction of the intermodel variability. In the course of the 21st century, burned area and C emissions from fires are shown to increase in Europe, in particular in the Mediterranean basins, in the Balkan regions and in Eastern Europe. However, the projected increase is lower than in other studies that did not fully account for the effect of climate on ecosystem functioning. We demonstrate that the lower sensitivity of burned area and C emissions to climate change is related to the predicted reduction of the net primary productivity, which is identified as the most important determinant of fire activity in the Mediterranean region after anthropogenic interaction. This behavior, consistent with the intermediate fire-productivity hypothesis, limits the sensitivity of future burned area and C emissions from fires on climate change, providing more conservative estimates of future fire patterns, and demonstrates the importance of coupling fire simulation with a climate driven ecosystem productivity model.

  14. Importance of soil thermal dynamics on land carbon sequestration in Northern Eurasia during the 21st century

    Science.gov (United States)

    Kicklighter, David; Monier, Erwan; Sokolov, Andrei; Zhuang, Qianlai; Melillo, Jerry

    2015-04-01

    Recent modeling studies have suggested that carbon sinks in pan-arctic ecosystems may be weakening partially as a result of warming-induced increases in soil organic matter (SOM) decomposition and the exposure of previously frozen SOM to decomposition. This weakening of carbon sinks is likely to continue in the future as vast amount of carbon in permafrost soils is vulnerable to thaw. Here, we examine the importance of considering soil thermal dynamics when determining the effects of climate change and land-use change on carbon dynamics in Northern Eurasia during the 21st century. This importance is assessed by comparing results for a "business as usual" scenario between a version of the Terrestrial Ecosystem Model that does not consider soil thermal dynamics (TEM 4.4) and a version that does consider these dynamics (TEM 6.0). In this scenario, which is similar to the IPCC Representative Concentration Pathways (RCP) 8.5 scenario, the net area covered by food crops and pastures in Northern Eurasia is assumed to remain relatively constant over the 21st century, but the area covered by secondary forests is projected to double as a result of timber harvest and the abandonment of land associated with displacement of agricultural land. Enhanced decomposition from the newly exposed SOM from permafrost thaw also increases nitrogen availability for plant production so that the loss of carbon from the enhanced decomposition is partially compensated by enhanced uptake and storage of atmospheric carbon dioxide in vegetation. Our results indicate that consideration of soil thermal dynamics have a large influence on how simulated terrestrial carbon dynamics in Northern Eurasia respond to changes in climate, atmospheric chemistry (e.g., carbon dioxide fertilization, ozone pollution, nitrogen deposition) and disturbances.

  15. Terrestrial carbon losses from mountaintop coal mining offset regional forest carbon sequestration in the 21st century

    International Nuclear Information System (INIS)

    Studies that quantify the spatial and temporal variability of carbon sources and sinks provide process-level information for the prediction of future levels of atmospheric carbon dioxide as well as verification of current emission agreements. Assessments of carbon sources and sinks for North America that compare top-down atmospheric constraints with bottom-up inventories find particularly large carbon sinks in the southeastern US. However, this southeastern US sink may be impacted by extreme land-use disturbance events due to mountaintop coal mining (MCM). Here we apply ecosystem modeling and field experiment data to quantify the potential impact of future mountaintop coal mining on the carbon budget of the southern Appalachian forest region. For projections based on historical mining rates, grassland reclamation, and the continued regrowth of un-mined forests, we find that the southern Appalachian forests switch from a net carbon sink to a net carbon source by year 2025–33 with a 30%–35% loss in terrestrial carbon stocks relative to a scenario with no future mining by the year 2100. Alternatively, scenarios of forest sequestration due to the effect of CO2 fertilization result in a 15%–24% loss in terrestrial carbon stocks by the year 2100 for mining scenarios relative to scenarios with no future mining. These results suggest that while power plant stack emissions are the dominant life-cycle stage in coal-fired electricity, accounting for mountaintop coal mining in bottom-up inventories may be a critical component of regional carbon budgets. (letter)

  16. One carbon metabolism and trisomy 21 : analysis of the impact of genetic polymorphism

    NARCIS (Netherlands)

    Chango, A; Mircher, C; James, SJ; Rethore, MO; Nicolas, JP

    2002-01-01

    Trisomy 21 is the most common chromosome abnormality characterized by the presence of three copies of chromosome 21 in the genome. The clinical disorder attributed to trisomy 21 is Down syndrome. Patients with Down syndrome are heterogeneous in their phenotypic expression. Due to the location of the

  17. Radiocarbon constraints imply reduced carbon uptake by soils during the 21st century

    Science.gov (United States)

    He, Yujie; Trumbore, Susan E.; Torn, Margaret S.; Harden, Jennifer W.; Vaughn, Lydia J.S.; Allison, Steven D.; Randerson, J.T.

    2016-01-01

    Soil is the largest terrestrial carbon reservoir and may influence the sign and magnitude of carbon cycle-climate feedbacks. Many Earth system models (ESMs) estimate a significant soil carbon sink by 2100, yet the underlying carbon dynamics determining this response have not been systematically tested against observations. We used 14C data from 157 globally distributed soil profiles sampled to 1 m depth to show that ESMs underestimated the mean age of soil carbon by more than six-fold (430±50 years vs. 3100±1800 years). Consequently, ESMs overestimated the carbon sequestration potential of soils by nearly two-fold (40±27%). These biases suggest that ESMs must better represent carbon stabilization processes and the turnover time of slow and passive reservoirs when simulating future atmospheric CO2 dynamics.

  18. 21 CFR 874.4500 - Ear, nose, and throat microsurgical carbon dioxide laser.

    Science.gov (United States)

    2010-04-01

    ... laser. 874.4500 Section 874.4500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND..., nose, and throat microsurgical carbon dioxide laser. (a) Identification. An ear, nose, and throat microsurgical carbon dioxide laser is a device intended for the surgical excision of tissue from the ear,...

  19. INTEGRATED CARBONATION: A NOVEL CONCEPT TO DEVELOP A CO2 SEQUESTRATION MODULE FOR VISION 21 POWER PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    Mercedes Maroto-Valer; John M. Andresen; Yinzhi Zhang; Matthew E. Kuchta

    2003-07-01

    The greatest challenge to achieve no environmental impact or zero emissions for the Vision 21 plants is probably greenhouse gases, especially CO{sub 2} emissions that are inevitably associated with fossil fuel combustion. Mineral carbonation, that involves the reaction of CO{sub 2} with non-carbonate minerals to form stable mineral carbonates, has been lately proposed as a promising CO{sub 2} sequestration technology due to the vast natural abundance of the raw minerals, the long term stability of the mineral carbonates formed, and the overall process being exothermic, and therefore, potentially economic viable. However, carbonation efficiency is being considered a major hurdle for the development of economically viable sequestration technologies, where present studies require extensive mineral particle communition, high pressures and prior capture of the CO{sub 2}. Consequently, mineral carbonation will only become a viable cost-effective sequestration technology through innovative development of fast reaction routes under milder regimes in a continuous process. The objective of the proposed novel active carbonation concept is to promote and accelerate reaction rates and efficiencies through surface activation to the extent that extensive mineral particle communition and high temperatures and pressures are not required. In this research program, serpentine was used as the carbonation feedstock material. Physical and chemical surface activation studies were conducted to promote its inherent carbonation reactivity. The activated materials were characterized by a battery of analytical techniques to determine their surface properties and assess their potential as carbonation minerals. Active carbonation studies were conducted and the carbonation activity was quantitatively determined by the increase of the weight of solid products and the percent of stoichiometric conversion. This work has shown that chemical activation was more effective than the physical activation

  20. Long-term Perspectives for Carbon Capture in Power Plants: Scenarios for the 21st Century

    OpenAIRE

    Riahi, K.; Barreto, L.; Rao, S.

    2004-01-01

    The report analyzes the role of fossil-fired power plants equipped with carbon capture systems in long-term scenarios of the global energy system representing technological change as an endogenous process. Within this framework the impacts of a technology policy is illustrated that requires over time an increasing fraction of fossil-fired power generation to incorporate carbon capture technologies. In particular, we examine the potential costs and the contribution that such a policy could off...

  1. Scenario analysis of China's emissions pathways in the 21st century for low carbon transition

    International Nuclear Information System (INIS)

    China's growing demand for energy - and its dependence on coal - has seen its carbon emissions increase more than 50% since 2000. Within the debate about mitigating global climate change, there is mounting pressure for emerging economies like China to take more responsibility for reducing their carbon emissions within a post-2012 international climate change policy framework. For China, this leads to fundamental questions about how feasible it is for the country to shift away from its recent carbon intensive pattern of growth. This paper presents some general results of scenarios that have been developed to investigate how China might continue to develop within a cumulative carbon emissions budget. The results show how changes in the key sectors of the Chinese economy could enable China to follow four different low carbon development pathways, each of which complies with a cumulative emissions constraint. Each scenario reflects different priorities for governmental decision making, infrastructure investments and social preferences. Having compared the key features of each scenario, the paper concludes with some implications for Chinese government policy.

  2. Scenario analysis of China's emissions pathways in the 21st century for low carbon transition

    International Nuclear Information System (INIS)

    China's growing demand for energy - and its dependence on coal - has seen its carbon emissions increase more than 50% since 2000. Within the debate about mitigating global climate change, there is mounting pressure for emerging economies like China to take more responsibility for reducing their carbon emissions within a post-2012 international climate change policy framework. For China, this leads to fundamental questions about how feasible it is for the country to shift away from its recent carbon intensive pattern of growth. This paper presents some general results of scenarios that have been developed to investigate how China might continue to develop within a cumulative carbon emissions budget. The results show how changes in the key sectors of the Chinese economy could enable China to follow four different low carbon development pathways, each of which complies with a cumulative emissions constraint. Each scenario reflects different priorities for governmental decision making, infrastructure investments and social preferences. Having compared the key features of each scenario, the paper concludes with some implications for Chinese government policy. (author)

  3. Projected changes of soil organic carbon in agricultural soils of southeast Germany in the 21th century under different carbon input scenarios

    Science.gov (United States)

    Wiesmeier, Martin; Poeplau, Christopher; Sierra, Carlos; Maier, Harald; Hübner, Rico; Kühnel, Anna; Spörlein, Peter; Geuß, Uwe; Hangen, Edzard; Schilling, Bernd; von Lützow, Margit; Kögel-Knabner, Ingrid

    2016-04-01

    As climate change may have a distinct effect on soil organic carbon (SOC) stocks, projections of the future SOC development on larger spatial scales on the basis of soil carbon models are needed. In this study we simulated the SOC development in cropland and grassland soils of Bavaria (southeast Germany) between 2000 and 2095 using the RothC model. At 51 sampling locations detailed model input data as C pools derived by soil fractionation, C input, clay content and climate variables were determined to run the model. Projections for each sampling location were performed on the basis of an average climate scenario (A1B) and three C input scenarios as a realistic range of possible crop yield developments: stagnation of the C input (1) increase by 20% (2) and decrease by 20% (3). The results showed a general decline of SOC stocks of 12% during the 21th century under C input scenario 1 and a decrease of 21% under scenario 3. Remarkably, even the optimistic scenario 2 resulted in a noticeable decline of SOC stocks by 5%. Our study indicated that C inputs in agricultural soils of Bavaria have to increase by 30% until 2095 (given the A1B climate scenario) in order to maintain present SOC stocks. However, projected SOC changes largely depended on the soil unit and regional site characteristics. The modeling approach provides the basis for a further evaluation of changes of the land use management and enables a site-specific delineation of measures for a sustainable supply of soil organic matter under climate change.

  4. Technologies for the 21st century: carbon nano tubes as adsorbents of metals

    International Nuclear Information System (INIS)

    Nowadays and in the recent past when the word nano appeared in almost anything it attracted immediate attention and interest, this is why carbon nano tubes, since its discovery nearly twenty years ago, caught the interest of a wide scientific and industrial population to apply the somewhat amazing properties of these nano materials in a number of applications. Among them, the removal of toxic and sometimes profitable metals from aqueous streams appeared, due to its economical and social impact, as one of the targets for their uses. This paper reviews some recent advances (2009-2013 years) in the application of carbon nano tubes materials in the removal of a variety of metals from these aqueous streams. (Author)

  5. Simulated 21st century's increase in oceanic suboxia by CO2-enhanced biotic carbon export

    Science.gov (United States)

    Oschlies, Andreas; Schulz, Kai G.; Riebesell, Ulf; Schmittner, Andreas

    2008-12-01

    The primary impacts of anthropogenic CO2 emissions on marine biogeochemical cycles predicted so far include ocean acidification, global warming induced shifts in biogeographical provinces, and a possible negative feedback on atmospheric CO2 levels by CO2-fertilized biological production. Here we report a new potentially significant impact on the oxygen-minimum zones of the tropical oceans. Using a model of global climate, ocean circulation, and biogeochemical cycling, we extrapolate mesocosm-derived experimental findings of a pCO2-sensitive increase in biotic carbon-to-nitrogen drawdown to the global ocean. For a simulation run from the onset of the industrial revolution until A.D. 2100 under a "business-as-usual" scenario for anthropogenic CO2 emissions, our model predicts a negative feedback on atmospheric CO2 levels, which amounts to 34 Gt C by the end of this century. While this represents a small alteration of the anthropogenic perturbation of the carbon cycle, the model results reveal a dramatic 50% increase in the suboxic water volume by the end of this century in response to the respiration of excess organic carbon formed at higher CO2 levels. This is a significant expansion of the marine "dead zones" with severe implications not only for all higher life forms but also for oxygen-sensitive nutrient recycling and, hence, for oceanic nutrient inventories.

  6. Materials for the 21st Century. Can the carbon come from CO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Kissling, S.; Altenbuchner, P.T.; Rieger, B. [Technische Univ. Muenchen (Germany). WACKER Lehrstuhl fuer Makromolekulare Chemie

    2012-07-01

    The major amount of synthetic polymers depend on petroleum feedstock. The topic of biodegradable plastics has drawn much attention since the discovery of poly(propylene carbonate) by Inoue, over 40 years ago. Coupling of carbon dioxide with epoxides leads to polycarbonates, which are temperature stable, biodegradable, firm, elastic and highly transparent. These properties open up a wide range of applications. The most preferable epoxide in the copolymerization is propylene oxide. Up to date, there are three different catalyst systems (zinc glutarates, zinc phenoxides and {beta}-diketiminato-zinc-complexes) containing zinc as a metal center. Due to the fact that heterogeneous zinc glutarates show low activities, our work focuses on homogenous catalyst systems. Herein it is a big challenge to avoid the formation of byproducts, namely the back-biting reaction and the consecutive insertion of epoxides. Therefore a catalyst must be designed to suppress these reactions. Furthermore, most of the zinc based catalysts are only active for the copolymerization of CO{sub 2} and cyclohexene oxide and not propylene oxide. The presentation will give a detailed insight into new catalyst structures and especially mechanistic aspects concerned with electronical and sterical influences of the polymerization catalyst. (orig.)

  7. Technologies for the 21st century: carbon nanotubes as adsorbents of metals

    Directory of Open Access Journals (Sweden)

    Alguacil, Francisco José

    2014-09-01

    Full Text Available Nowadays and in the recent past when the word “nano” appeared in almost anything it attracted immediate attention and interest, this is why carbon nanotubes, since its discovery nearly twenty years ago, caught the interest of a wide scientific and industrial population to apply the somewhat amazing properties of these nanomaterials in a number of applications. Among them, the removal of toxic and sometimes profitable metals from aqueous streams appeared, due to its economical and social impact, as one of the targets for their uses. This paper reviews some recent advances (2009–2013 years in the application of carbon nanotubes materials in the removal of a variety of metals from these aqueous streams.Tanto en el pasado como hoy en día, cuando la palabra “nano” aparece en cualquier sitio inmediatamente suscita atención e interés; por eso y desde su descubrimiento hace cerca de veinte años, los nanotubos de carbono interesaron tanto a científicos como a industriales, que utilizaron las propiedades de estos nanomateriales en una serie de aplicaciones. Entre éstas, se incluye la eliminación de metales tóxicos, y otros con un cierto valor económico, de medios acuosos, problemática que además tiene unas implicaciones económicas y sociales importantes. Este trabajo revisa los avances más recientes (años 2009–2013 de la utilización de estos nanotubos de carbono en la eliminación de una serie de metales contenidos en distintos medios acuosos.

  8. Global and regional effects of land-use change on climate in 21st century simulations with interactive carbon cycle

    Directory of Open Access Journals (Sweden)

    L. R. Boysen

    2014-09-01

    Full Text Available Biogeophysical (BGP and biogeochemical (BGC effects of land-use and land cover change (LULCC are separated at the global and regional scales in new interactive CO2 simulations for the 21st century. Results from four earth system models (ESMs are analyzed for the future RCP8.5 scenario from simulations with and without land-use and land cover change (LULCC, contributing to the Land-Use and Climate, IDentification of robust impacts (LUCID project. Over the period 2006–2100, LULCC causes the atmospheric CO2 concentration to increase by 12, 22, and 66 ppm in CanESM2, MIROC-ESM, and MPI-ESM-LR, respectively. Statistically significant changes in global near-surface temperature are found in three models with a BGC-induced global mean annual warming between 0.07 and 0.23 K. BGP-induced responses are simulated by three models in areas of intense LULCC of varying sign and magnitude (between −0.47 and 0.10 K. Modifications of the land carbon pool by LULCC are disentangled in accordance with processes that can lead to increases and decreases in this carbon pool. Global land carbon losses due to LULCC are simulated by all models: 218, 57, 35 and 34 Gt C by MPI-ESM-LR, MIROC-ESM, IPSL-CM5A-LR and CanESM2, respectively. On the contrary, the CO2-fertilization effect caused by elevated atmospheric CO2 concentrations due to LULCC leads to a land carbon gain of 39 Gt C in MPI-ESM-LR and is almost negligible in the other models. A substantial part of the spread in models' responses to LULCC is attributed to the differences in implementation of LULCC (e.g., whether pastures or crops are simulated explicitly and the simulation of specific processes. Simple idealized experiments with clear protocols for implementing LULCC in ESMs are needed to increase the understanding of model responses and the statistical significance of results, especially when analyzing the regional-scale impacts of LULCC.

  9. Projected loss of soil organic carbon in temperate agricultural soils in the 21(st) century: effects of climate change and carbon input trends.

    Science.gov (United States)

    Wiesmeier, Martin; Poeplau, Christopher; Sierra, Carlos A; Maier, Harald; Frühauf, Cathleen; Hübner, Rico; Kühnel, Anna; Spörlein, Peter; Geuß, Uwe; Hangen, Edzard; Schilling, Bernd; von Lützow, Margit; Kögel-Knabner, Ingrid

    2016-01-01

    Climate change and stagnating crop yields may cause a decline of SOC stocks in agricultural soils leading to considerable CO2 emissions and reduced agricultural productivity. Regional model-based SOC projections are needed to evaluate these potential risks. In this study, we simulated the future SOC development in cropland and grassland soils of Bavaria in the 21(st) century. Soils from 51 study sites representing the most important soil classes of Central Europe were fractionated and derived SOC pools were used to initialize the RothC soil carbon model. For each site, long-term C inputs were determined using the C allocation method. Model runs were performed for three different C input scenarios as a realistic range of projected yield development. Our modelling approach revealed substantial SOC decreases of 11-16% under an expected mean temperature increase of 3.3 °C assuming unchanged C inputs. For the scenario of 20% reduced C inputs, agricultural SOC stocks are projected to decline by 19-24%. Remarkably, even the optimistic scenario of 20% increased C inputs led to SOC decreases of 3-8%. Projected SOC changes largely differed among investigated soil classes. Our results indicated that C inputs have to increase by 29% to maintain present SOC stocks in agricultural soils. PMID:27585648

  10. Global and regional effects of land-use change on climate in 21st century simulations with interactive carbon cycle

    Directory of Open Access Journals (Sweden)

    L. R. Boysen

    2014-04-01

    Full Text Available Biogeophysical (BGP and biogeochemical (BGC effects of land-use and land cover change (LULCC are separated at the global and regional scales in new interactive CO2 simulations for the 21st century. Results from four Earth System models (ESMs are analyzed for the future RCP8.5 scenario from simulations with and without land-use and land cover change (LULCC contributing to the Land-Use and Climate, IDentification of robust impacts (LUCID project. Over the period, 2006–2100, LULCC causes the atmospheric CO2 concentration to increase by 12, 22, and 66 ppm in CanESM2, MIROC-ESM, and MPI-ESM-LR, respectively. Statistically significant changes in global near-surface temperature are found in three models with a BGC-induced global mean annual warming between 0.07 and 0.23 K. BGP-induced responses are simulated by three models in areas of intense LULCC of varying sign and magnitude (between −0.47 and 0.10 K. Global land carbon losses due to LULCC are simulated by all models: 218, 57, 35 and 34 Gt C by MPI-ESM-LR, MIROC-ESM, IPSL-CM5A-LR and CanESM2, respectively. On the contrary, the CO2-fertilization effect caused by elevated atmospheric CO2 concentrations due to LULCC leads to a land carbon gain of 39 Gt C in MPI-ESM-LR and is almost negligible in the other models. A substantial part of the spread in models' responses to LULCC is attributed to the differences in implementation of LULCC (e.g. whether pastures or crops are simulated explicitly and the simulation of specific processes. Simple idealized experiments with clear protocols for implementing LULCC in ESMs are needed to increase the understanding of model responses and the statistical significance of results, especially, when analyzing the regional-scale impacts of LULCC.

  11. Changing black carbon transport to the Arctic from present day to the end of 21st century

    Science.gov (United States)

    Jiao, Chaoyi; Flanner, Mark G.

    2016-05-01

    Here we explore how climate warming under the Representative Concentration Pathway 8.5 (RCP8.5) impacts Arctic aerosol distributions via changes in atmospheric transport and removal processes. We modify the bulk aerosol module in the Community Atmosphere Model to track distributions and fluxes of 200 black carbon-like tracers emitted from different locations, and we conduct idealized experiments with and without active aerosol deposition. Changing wind patterns, studied in isolation, cause the Arctic burdens of tracers emitted from East Asia and West Europe during winter to increase about 20% by the end of the century while decreasing the Arctic burdens of North American emissions by about 30%. These changes are caused by an altered winter polar dome structure that results from Arctic amplification and inhomogeneous sea ice loss and surface warming, both of which are enhanced in the Chukchi Sea region. The resulting geostrophic wind favors Arctic transport of East Asian emissions while inhibiting poleward transport of North American emissions. When active deposition is also considered, however, Arctic burdens of emissions from northern midlatitudes show near-universal decline. This is a consequence of increased precipitation and wet removal, particularly within the Arctic, leading to decreased Arctic residence time. Simulations with present-day emissions of black carbon indicate a 13.6% reduction in the Arctic annual mean burden by the end of the 21st century, due to warming-induced transport and deposition changes, while simulations with changing climate and emissions under RCP8.5 show a 61.0% reduction.

  12. On the Southern Ocean CO2 uptake and the role of the biological carbon pump in the 21st century

    Science.gov (United States)

    Hauck, J.; Völker, C.; Wolf-Gladrow, D. A.; Laufkötter, C.; Vogt, M.; Aumont, O.; Bopp, L.; Buitenhuis, E. T.; Doney, S. C.; Dunne, J.; Gruber, N.; Hashioka, T.; John, J.; Quéré, C. Le; Lima, I. D.; Nakano, H.; Séférian, R.; Totterdell, I.

    2015-09-01

    We use a suite of eight ocean biogeochemical/ecological general circulation models from the Marine Ecosystem Model Intercomparison Project and Coupled Model Intercomparison Project Phase 5 archives to explore the relative roles of changes in winds (positive trend of Southern Annular Mode, SAM) and in warming- and freshening-driven trends of upper ocean stratification in altering export production and CO2 uptake in the Southern Ocean at the end of the 21st century. The investigated models simulate a broad range of responses to climate change, with no agreement on a dominance of either the SAM or the warming signal south of 44°S. In the southernmost zone, i.e., south of 58°S, they concur on an increase of biological export production, while between 44 and 58°S the models lack consensus on the sign of change in export. Yet in both regions, the models show an enhanced CO2 uptake during spring and summer. This is due to a larger CO2(aq) drawdown by the same amount of summer export production at a higher Revelle factor at the end of the 21st century. This strongly increases the importance of the biological carbon pump in the entire Southern Ocean. In the temperate zone, between 30 and 44°S, all models show a predominance of the warming signal and a nutrient-driven reduction of export production. As a consequence, the share of the regions south of 44°S to the total uptake of the Southern Ocean south of 30°S is projected to increase at the end of the 21st century from 47 to 66% with a commensurable decrease to the north. Despite this major reorganization of the meridional distribution of the major regions of uptake, the total uptake increases largely in line with the rising atmospheric CO2. Simulations with the MITgcm-REcoM2 model show that this is mostly driven by the strong increase of atmospheric CO2, with the climate-driven changes of natural CO2 exchange offsetting that trend only to a limited degree (˜10%) and with negligible impact of climate effects on

  13. Boreal and temperate snow cover variations induced by black carbon emissions in the middle of the 21st century

    Directory of Open Access Journals (Sweden)

    M. Ménégoz

    2013-03-01

    Full Text Available We used a coupled climate-chemistry model to quantify the impacts of aerosols on snow cover north of 30° N both for the present-day and for the middle of the 21st century. Black carbon (BC deposition over continents induces a reduction in the mean number of days with snow at the surface (MNDWS that ranges from 0 to 10 days over large areas of Eurasia and Northern America for the present-day relative to the pre-industrial period. This is mainly due to BC deposition during the spring, a period of the year when the remaining of snow accumulated during the winter is exposed to both strong solar radiation and a large amount of aerosol deposition induced themselves by a high level of transport of particles from polluted areas. North of 30° N, this deposition flux represents 222 Gg BC month−1 on average from April to June in our simulation. A large reduction in BC emissions is expected in the future in all of the Representative Concentration Pathway (RCP scenarios. In particular, considering the RCP8.5 in our simulation leads to a decrease in the spring BC deposition down to 110 Gg month−1 in the 2050s. However, despite the reduction of the aerosol impact on snow, the MNDWS is strongly reduced by 2050, with a decrease ranging from 10 to 100 days from present-day values over large parts of the Northern Hemisphere. This reduction is essentially due to temperature increase, which is quite strong in the RCP8.5 scenario in the absence of climate mitigation policies. Moreover, the projected sea-ice retreat in the next decades will open new routes for shipping in the Arctic. However, a large increase in shipping emissions in the Arctic by the mid-21st century does not lead to significant changes of BC deposition over snow-covered areas in our simulation. Therefore, the MNDWS is clearly not affected through snow darkening effects associated with these Arctic ship emissions. In an experiment without nudging toward atmospheric reanalyses, we simulated

  14. DREAM-World: a simple model of energy-related carbon emissions in the 20th and 21st centuries

    Energy Technology Data Exchange (ETDEWEB)

    Boyle, G.

    2000-09-01

    This paper describes DREAM-World, a simple model of global carbon emissions using logistic equations to describe the variations, over the period 1900-2100, in world population, GDP per capita, energy intensity and carbon intensity. The resulting simulations of historical and projected future carbon emissions are in reasonably good agreement with both the historical emissions data and with three published future emission scenarios, chosen to reflect a wide range of possibilities. The use of logistic equations highlights the need to consider when the inflection points in key variables, such as GDP per capita, will occur in future. The modelling exercise also highlights the fact that, because energy intensity cannot in principle reach zero whereas carbon intensity can, energy efficiency improvements can only buy time in the carbon abatement process: a shift to carbon-free energy sources is ultimately required - if global economic growth is to continue. (Author)

  15. Reconstitution of CO2 Regulation of SLAC1 Anion Channel and Function of CO2-Permeable PIP2;1 Aquaporin as CARBONIC ANHYDRASE4 Interactor.

    Science.gov (United States)

    Wang, Cun; Hu, Honghong; Qin, Xue; Zeise, Brian; Xu, Danyun; Rappel, Wouter-Jan; Boron, Walter F; Schroeder, Julian I

    2016-02-01

    Dark respiration causes an increase in leaf CO2 concentration (Ci), and the continuing increases in atmospheric [CO2] further increases Ci. Elevated leaf CO2 concentration causes stomatal pores to close. Here, we demonstrate that high intracellular CO2/HCO3 (-) enhances currents mediated by the Arabidopsis thaliana guard cell S-type anion channel SLAC1 upon coexpression of any one of the Arabidopsis protein kinases OST1, CPK6, or CPK23 in Xenopus laevis oocytes. Split-ubiquitin screening identified the PIP2;1 aquaporin as an interactor of the βCA4 carbonic anhydrase, which was confirmed in split luciferase, bimolecular fluorescence complementation, and coimmunoprecipitation experiments. PIP2;1 exhibited CO2 permeability. Mutation of PIP2;1 in planta alone was insufficient to impair CO2- and abscisic acid-induced stomatal closing, likely due to redundancy. Interestingly, coexpression of βCA4 and PIP2;1 with OST1-SLAC1 or CPK6/23-SLAC1 in oocytes enabled extracellular CO2 enhancement of SLAC1 anion channel activity. An inactive PIP2;1 point mutation was identified that abrogated water and CO2 permeability and extracellular CO2 regulation of SLAC1 activity. These findings identify the CO2-permeable PIP2;1 as key interactor of βCA4 and demonstrate functional reconstitution of extracellular CO2 signaling to ion channel regulation upon coexpression of PIP2;1, βCA4, SLAC1, and protein kinases. These data further implicate SLAC1 as a bicarbonate-responsive protein contributing to CO2 regulation of S-type anion channels. PMID:26764375

  16. The carbon balance pivot point of southwestern U.S. semiarid ecosystems: Insights from the 21st century drought

    Science.gov (United States)

    Scott, Russell L.; Biederman, Joel A.; Hamerlynck, Erik P.; Barron-Gafford, Greg A.

    2015-12-01

    Global-scale studies indicate that semiarid regions strongly regulate the terrestrial carbon sink. However, we lack understanding of how climatic shifts, such as decadal drought, impact carbon sequestration across the wide range of structural diversity in semiarid ecosystems. Therefore, we used eddy covariance measurements to quantify how net ecosystem production of carbon dioxide (NEP) differed with relative grass and woody plant abundance over the last decade of drought in four Southwest U.S. ecosystems. We identified a precipitation "pivot point" in the carbon balance for each ecosystem where annual NEP switched from negative to positive. Ecosystems with grass had pivot points closer to the drought period precipitation than the predrought average, making them more likely to be carbon sinks (and a grass-free shrubland, a carbon source) during the current drought. One reason for this is that the grassland located closest to the shrubland supported higher leaf area and photosynthesis at the same water availability. Higher leaf area was associated with a greater proportion of evapotranspiration being transpiration (T/ET), and therefore with higher ecosystem water use efficiency (gross ecosystem photosynthesis/ET). Our findings strongly show that water availability is a primary driver of both gross and net semiarid productivity and illustrate that structural differences may contribute to the speed at which ecosystem carbon cycling adjusts to climatic shifts.

  17. Soil temperature response to 21st century global warming: the role of and some implications for peat carbon in thawing permafrost soils in North America

    Directory of Open Access Journals (Sweden)

    D. Wisser

    2011-06-01

    Full Text Available Northern peatlands contain a large terrestrial carbon pool that plays an important role in the Earth's carbon cycle. A considerable fraction of this carbon pool is currently in permafrost and is biogeochemically relatively inert; this will change with increasing soil temperatures as a result of climate warming in the 21st century. We use a geospatially explicit representation of peat areas and peat depth from a recently-compiled database and a geothermal model to estimate northern North America soil temperature responses to predicted changes in air temperature. We find that, despite a widespread decline in the areas classified as permafrost, soil temperatures in peatlands respond more slowly to increases in air temperature owing to the insulating properties of peat. We estimate that an additional 670 km3 of peat soils in North America, containing ~33 Pg C, could be seasonally thawed by the end of the century, representing ~20 % of the total peat volume in Alaska and Canada. Warming conditions result in a lengthening of the soil thaw period by ~40 days, averaged over the model domain. These changes have potentially important implications for the carbon balance of peat soils.

  18. Soil temperature response to 21st century global warming: the role of and some implications for peat carbon in thawing permafrost soils in North America

    Directory of Open Access Journals (Sweden)

    D. Wisser

    2011-02-01

    Full Text Available Northern peatlands contain a large terrestrial carbon pool that plays an important role in the Earth's carbon cycle. A considerable fraction of this carbon pool is currently in permafrost and is biogeochemically relatively inert; this will change with increasing soil temperatures as a result of climate warming in the 21st century. We use a geospatially explicit representation of peat areas and peat depth from a recently-compiled database and a geothermal model to estimate northern North America soil temperature responses to predicted changes in air temperature. We find that, despite a widespread decline in the areas classified as permafrost, soil temperatures in peatlands respond more slowly to increases in air temperature owing to the insulating properties of peat. We estimate that an additional 670 km3 of peat soils in North America, containing ~33 Pg C, could be seasonally thawed by the end of the century, representing ~20% of the total peat volume in Alaska and Canada. Warming conditions result in a lengthening of the soil thaw period by ~40 days, averaged over the model domain. These changes have potentially important implications for the carbon balance of peat soils.

  19. Soil temperature response to 21st century global warming: the role of and some implications for peat carbon in thawing permafrost soils in North America

    Science.gov (United States)

    Wisser, D.; Marchenko, S.; Talbot, J.; Treat, C.; Frolking, S.

    2011-06-01

    Northern peatlands contain a large terrestrial carbon pool that plays an important role in the Earth's carbon cycle. A considerable fraction of this carbon pool is currently in permafrost and is biogeochemically relatively inert; this will change with increasing soil temperatures as a result of climate warming in the 21st century. We use a geospatially explicit representation of peat areas and peat depth from a recently-compiled database and a geothermal model to estimate northern North America soil temperature responses to predicted changes in air temperature. We find that, despite a widespread decline in the areas classified as permafrost, soil temperatures in peatlands respond more slowly to increases in air temperature owing to the insulating properties of peat. We estimate that an additional 670 km3 of peat soils in North America, containing ~33 Pg C, could be seasonally thawed by the end of the century, representing ~20 % of the total peat volume in Alaska and Canada. Warming conditions result in a lengthening of the soil thaw period by ~40 days, averaged over the model domain. These changes have potentially important implications for the carbon balance of peat soils.

  20. Pan-Arctic land–atmospheric fluxes of methane and carbon dioxide in response to climate change over the 21st century

    International Nuclear Information System (INIS)

    Future changes of pan-Arctic land–atmospheric methane (CH4) and carbon dioxide (CO2) depend on how terrestrial ecosystems respond to warming climate. Here, we used a coupled hydrology–biogeochemistry model to make our estimates of these carbon exchanges with two contrasting climate change scenarios (no-policy versus policy) over the 21st century, by considering (1) a detailed water table dynamics and (2) a permafrost-thawing effect. Our simulations indicate that, under present climate conditions, pan-Arctic terrestrial ecosystems act as a net greenhouse gas (GHG) sink of −0.2 Pg CO2-eq. yr−1, as a result of a CH4 source (53 Tg CH4 yr−1) and a CO2 sink (−0.4 Pg C yr−1). In response to warming climate, both CH4 emissions and CO2 uptakes are projected to increase over the century, but the increasing rates largely depend on the climate change scenario. Under the non-policy scenario, the CH4 source and CO2 sink are projected to increase by 60% and 75% by 2100, respectively, while the GHG sink does not show a significant trend. Thawing permafrost has a small effect on GHG sink under the policy scenario; however, under the no-policy scenario, about two thirds of the accumulated GHG sink over the 21st century has been offset by the carbon losses as CH4 and CO2 from thawing permafrost. Over the century, nearly all CO2-induced GHG sink through photosynthesis has been undone by CH4-induced GHG source. This study indicates that increasing active layer depth significantly affects soil carbon decomposition in response to future climate change. The methane emissions considering more detailed water table dynamics continuously play an important role in affecting regional radiative forcing in the pan-Arctic. (letter)

  1. The Carbon Balance Pivot Point of Southwestern U.S. Semiarid Ecosystems: Insights From the 21st Century Drought

    Science.gov (United States)

    Scott, R. L.; Biederman, J.; Barron-Gafford, G.; Hamerlynck, E. P.

    2015-12-01

    Global-scale studies indicate that semiarid ecosystems strongly regulate the long-term trend and interannual variability of the terrestrial carbon sink, possibly due to changes in vegetation and an inherent sensitivity to changes in water availability. However, we lack understanding of how climate shifts, such as the ongoing decadal-scale drought in the Southwest US, impact carbon sink functioning in semiarid ecosystems with differing structure. Therefore, we investigated the response of net ecosystem production of carbon dioxide (NEP) to changes in annual water availability in four Southwest US ecosystems varying in relative shrub, tree and grass abundance. Using eddy covariance carbon dioxide and water vapor flux measurements collected over the last drought-impacted decade, we identified a precipitation "pivot point" in the annual carbon balance for each ecosystem type where annual NEP switched from negative to positive. At the three sites with larger amounts of grass, rather than woody plant, cover, pivot points were closer to the drought-period mean annual precipitation (MAP) than MAP over the preceding 30 years, suggesting the carbon pools of these grassier ecosystems have more quickly adjusted to the decadal-scale drought. Current-year water availability, as quantified by evapotranspiration (ET) overwhelmingly drove the response of gross ecosystem photosynthesis (GEP) and respiration (Reco) fluxes. Ecosystem water use efficiency (GEP/ET) increased with water availability and leaf area index, resulting in a more efficient photosynthetic use of water in wetter years and at wetter sites. Grasslands supported a higher leaf area than shrublands at a given water availability, and thus had higher GEP/ET. Differences in GEP/ET were also related to the relative proportion of abiotic evaporation, estimated from the ET intercept in a linear regression of ET and GEP, to total ET at a site, highlighting the importance of ET partitioning for understanding how semiarid

  2. Elucidating the fate, transport and processes controlling carbon on the landscape: Biogeochemistry tools for the 21st century

    Science.gov (United States)

    McFarlane, K. J.; Keiluweit, M.; Nico, P. S.; Ognibene, T.; Mayali, X.; Nuccio, E.; Weber, P. K.; Pett-Ridge, J.; Guilderson, T. P.

    2013-12-01

    Globally, more carbon is stored belowground as soil organic matter than in terrestrial vegetation and the atmosphere combined. A critical scientific question is how soils serve as sources and sinks for atmospheric carbon dioxide (CO2) and how these sinks will evolve with expected changes in atmospheric CO2 concentrations, climate, and land-use. Carbon initially enters belowground soil pools as plant detritus, roots, and root exudates. Once in the soil, this organic matter serves as a substrate for decomposer organisms including soil animals, bacteria, and fungi. Most of this carbon is consumed and respired as CO2, but some is converted to microbial biomass and byproducts, which may leave the soil as dissolved organic carbon, be used as a substrate by other microbes, or be stabilized within the soil mineral matrix. Mechanisms that result in the stabilization of soils include: climate stabilization, physical protection within aggregates and organo-mineral complexes, and protection of potential substrates due to physiochemical barriers. These processes, which span broad temporal and spatial scales, are poorly constrained in many dynamic land surface models. At LLNL, we have developed a suite of analytical tools that allow us to follow the movement of carbon at the cell to landscape scale, including: ';Chip-SIP', ';STXM-SIMS', and new sample interfaces for accelerator mass spectrometry (AMS). Experiments, field-based and in vivo, allow us to further the mechanistic understanding of factors that control the fate, transport, and sequestration potential of belowground carbon. The Chip-SIP approach allows us to interrogate which microbial species in a complex community incorporate specific substrates (e.g. cellulose) in order to understand the production of biofuels and better elucidate energy and carbon transfers in wetlands and soils. To disentangle the complex interactions at soil-microbial-film-mineral interfaces with minimal disruption we are using a combination of

  3. Cleaner fossil power generation in the 21st century: a technology strategy for carbon capture and storage

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-04-15

    The document describes how the research, development and demonstration (RD&D) components of the United Kingdom Government's Carbon Abatement Technologies (CATs) Strategy should be developed and extended, with particular reference to a 2020 target for carbon dioxide capture and storage (CCS) commercialisation and the 2050 UK Committee on Climate Change (CCC) dioxide target. It sets out a strategy for RD&D through the establishment of a collaborative programme linking industry, and academia, and involving different funding sources. The proposed RD& D programme has seven strategic themes: Power plant: focus on cost, increasing efficiency, biomass co-firing; Capture technologies: focus on cost, efficiency penalty, waste heat utilisation; storage: focus on security, monitoring and verification; transport: focus on logistics and transport network; whole system: focus on risks, transient capability, economics, environmental issues; advanced and novel capture technologies; and underpinning technology support. 11 refs., 10 figs., 15 tabs.

  4. Towards an integrated scientific approach for carbon accounting in forestry. COST E21 Workshop. Contribution of forests and forestry to mitigate greenhouse effects. Joensuu (Finland). 28-30 Sep 2000

    OpenAIRE

    Karjalainen T.; Laitat E.; Loustau D.; Lindner M.

    2000-01-01

    In the COST E21-Action ""Contribution of Forests and Forestry to Mitigate Greenhouse Effects"", emphasis is put on the quantification of carbon storage in the forest ecosystems and on the understanding of linkages between human activities and climate change, particularly the role of forests and forestry. COST E21 integrates natural, socio-economic as well as methodological aspects relevant for reporting under the unitéd Nations Framework Convention on Climate Change and the Kyoto Protocol, as...

  5. Reduced-Order Model for the Geochemical Impacts of Carbon Dioxide, Brine and Trace Metal Leakage into an Unconfined, Oxidizing Carbonate Aquifer, Version 2.1

    Energy Technology Data Exchange (ETDEWEB)

    Bacon, Diana H.

    2013-03-31

    The National Risk Assessment Partnership (NRAP) consists of 5 U.S DOE national laboratories collaborating to develop a framework for predicting the risks associated with carbon sequestration. The approach taken by NRAP is to divide the system into components, including injection target reservoirs, wellbores, natural pathways including faults and fractures, groundwater and the atmosphere. Next, develop a detailed, physics and chemistry-based model of each component. Using the results of the detailed models, develop efficient, simplified models, termed reduced order models (ROM) for each component. Finally, integrate the component ROMs into a system model that calculates risk profiles for the site. This report details the development of the Groundwater Geochemistry ROM for the Edwards Aquifer at PNNL. The Groundwater Geochemistry ROM for the Edwards Aquifer uses a Wellbore Leakage ROM developed at LANL as input. The detailed model, using the STOMP simulator, covers a 5x8 km area of the Edwards Aquifer near San Antonio, Texas. The model includes heterogeneous hydraulic properties, and equilibrium, kinetic and sorption reactions between groundwater, leaked CO2 gas, brine, and the aquifer carbonate and clay minerals. Latin Hypercube sampling was used to generate 1024 samples of input parameters. For each of these input samples, the STOMP simulator was used to predict the flux of CO2 to the atmosphere, and the volume, length and width of the aquifer where pH was less than the MCL standard, and TDS, arsenic, cadmium and lead exceeded MCL standards. In order to decouple the Wellbore Leakage ROM from the Groundwater Geochemistry ROM, the response surface was transformed to replace Wellbore Leakage ROM input parameters with instantaneous and cumulative CO2 and brine leakage rates. The most sensitive parameters proved to be the CO2 and brine leakage rates from the well, with equilibrium coefficients for calcite and dolomite, as well as the number of illite and kaolinite

  6. Solid phase extraction of trace Cu(IIusing Naphtol-2-(Pyridylazo-2-1 (PAN modified Single walled carbon nanotubes (SWCNTs to Determination by FAAS

    Directory of Open Access Journals (Sweden)

    Ali Moghimi

    2014-09-01

    Full Text Available A simple, reliable and rapid method for preconcentration and modified solid phase C18 with Single-Walled Carbon Nano tubes with Naphtol-2-(Pyridylazo-2-1 (PAN in order to prepare an effective sorbent for the preconcentration and determination of copper. The sorption capacity of Naphtol-2-(Pyridylazo-2-1 (PAN -modified Single walled carbon nano tubes (SWCNTs was 50 mg.g -1 and the optimum pH for the quantitative recovery of copper was found as 3.0. The optimum flow rate, sorbent amount and sample volume were1.0 mL.min-1, 300 mg and 50 mL, respectively. 5 mL of 4 mol.L-1 HNO3 was the most suitable eluent. The recommended method is simple and reliable for the determination of copper without any notable matrix effect and successfully applied to environmental water samples. The results of this study show that little amount of Cu2+ ion with the aid of minimum chemical substacnces, in a relatively short amount of time, and with high percentage of recovery, can be isolated and identified. In this method, the detection limits equal to 0.1µg.mL-1, were achieved with the experiment’s relative standard deviation of (n=10 equal to 1.25% factor prior to condensation equating to 125 and the column capacity of 205 µg for each adsorbent.The accuracy of the proposed method was compared with other standard methods, it became clear superiority. Similar experiments on natural samples under optimal conditions have proven the efficiency of this method at an industrial scale.

  7. Carbon capture and storage in deep ocean space for the 21st century: guidelines for implementation in China

    OpenAIRE

    Livermont, Elizabeth A.; Koh, YongJie; Mlambo, Taurai; Bhawanin, Mahesa; Zhao, BinBin

    2011-01-01

    Since the original findings of the Swedish Nobel laureate Arrhenius in 1896 linking the temperature of the Earth to the gaseous composition of our atmosphere we have come a long way. However, one of the most startling observations is the increasing mean carbon dioxide concentration at Mauna Loa, Hawaii. Recordings from 1960 to the present show a total increase of almost 80 ppm CO2 to the present value of 392 in July 2011. Even without the implications on climate change, the simple fact that a...

  8. [Determination of 21 organophosphorus pesticides in tea by gas chromatography-mass spectrometry coupled with hydroxylated multi-walled carbon nanotubes based on dispersive solid-phase extraction].

    Science.gov (United States)

    Rong, Jiefeng; Wei, Hang; Li, Yijun; Huang, Huoshui; Xu, Meizhu

    2016-02-01

    A rapid determination method of 21 organophosphorus pesticides in tea was developed by QuEChERS method using modified multi-walled carbon nanotubes (MWCNTs-OH), primary-secondary amine (PSA) and MgSO4 coupled with gas chromatography-mass spectrometry. The pesticide residues in tea were extracted with a hexane-acetone (2:1, v/v) mixture, and cleaned up by dispersive solid-phase extraction using MWCNTs-OH and primary-secondary amine (PSA) as the sorbents. After centrifugation and filtration, the target compounds were analyzed by gas chromatography-mass spectrometry and quantified by the external standard method. Under the optimized conditions, good linearities were obtained in the range of 0. 01- 0. 50 mg/kg. The average recoveries were in the range of 81. 5% -109. 4% at three spiked levels, with relative standard deviations (RSDs, n = 5 ) of 2. 3% - 10. 6%. The limits of quantification were 0. 001-0. 040 mg/kg. This method is simple, fast, sensitive, cheap, and can meet the requirements of the rapid detection of organophosphorus pesticides in tea.

  9. [Determination of 21 organophosphorus pesticides in tea by gas chromatography-mass spectrometry coupled with hydroxylated multi-walled carbon nanotubes based on dispersive solid-phase extraction].

    Science.gov (United States)

    Rong, Jiefeng; Wei, Hang; Li, Yijun; Huang, Huoshui; Xu, Meizhu

    2016-02-01

    A rapid determination method of 21 organophosphorus pesticides in tea was developed by QuEChERS method using modified multi-walled carbon nanotubes (MWCNTs-OH), primary-secondary amine (PSA) and MgSO4 coupled with gas chromatography-mass spectrometry. The pesticide residues in tea were extracted with a hexane-acetone (2:1, v/v) mixture, and cleaned up by dispersive solid-phase extraction using MWCNTs-OH and primary-secondary amine (PSA) as the sorbents. After centrifugation and filtration, the target compounds were analyzed by gas chromatography-mass spectrometry and quantified by the external standard method. Under the optimized conditions, good linearities were obtained in the range of 0. 01- 0. 50 mg/kg. The average recoveries were in the range of 81. 5% -109. 4% at three spiked levels, with relative standard deviations (RSDs, n = 5 ) of 2. 3% - 10. 6%. The limits of quantification were 0. 001-0. 040 mg/kg. This method is simple, fast, sensitive, cheap, and can meet the requirements of the rapid detection of organophosphorus pesticides in tea. PMID:27382726

  10. Improving the tensile strength of carbon nanotube yarn via one-step double [2+1] cycloadditions

    Energy Technology Data Exchange (ETDEWEB)

    Kim, HeeJin [Kyungpook National University, Daegu (Korea, Republic of); Lee, Jaegeun; Park, Byungrak; Sa, Jeong Hoon; Jung, Alum; Kim, Teawon; Park, Junbeom; Hwang, Woonbong; Lee, Kun Hong [Pohang University of Science and Technology, Pohang (Korea, Republic of)

    2016-01-15

    The tensile strength of a CNT yarn was improved through simple one-step double [2+1] cycloaddition reactions that crosslinked the constituent CNTs using a polyethylene glycol (PEG)-diazide crosslinker. The FT-IR spectrum confirmed that the azide groups in the PEG-diazide were converted into aziridine rings, indicating that the cycloaddition reaction was successful. The generation of crosslinked CNTs was also supported by the observation of N1s peak in the XPS spectrum and the increased thermal stability of the material, as observed by TGA. The tensile strength of the CNT yarn was increased from 0.2GPa to 1.4GPa after the crosslinking reaction when twisted at 4000 twists/ meter. The appropriate selection of the crosslinker may further optimize the CNT yarn crosslinking reaction. The simplicity of this one-step crosslinking reaction provides an economical approach to the mass production of high-strength CNT yarns.

  11. Soil temperature response to 21st century global warming: the role of and some implications for peat carbon in thawing permafrost soils in North America

    NARCIS (Netherlands)

    Wisser, D.; Marchenko, S.; Talbot, J.; Treat, C.; Frolking, S.

    2011-01-01

    Northern peatlands contain a large terrestrial carbon pool that plays an important role in the Earth’s carbon cycle. A considerable fraction of this carbon pool is currently in permafrost and is biogeochemically relatively inert; this will change with increasing soil temperatures as a result of clim

  12. Towards an integrated scientific approach for carbon accounting in forestry. COST E21 Workshop. Contribution of forests and forestry to mitigate greenhouse effects. Joensuu (Finland. 28-30 Sep 2000

    Directory of Open Access Journals (Sweden)

    Karjalainen T.

    2000-01-01

    Full Text Available In the COST E21-Action ""Contribution of Forests and Forestry to Mitigate Greenhouse Effects"", emphasis is put on the quantification of carbon storage in the forest ecosystems and on the understanding of linkages between human activities and climate change, particularly the role of forests and forestry. COST E21 integrates natural, socio-economic as well as methodological aspects relevant for reporting under the unitéd Nations Framework Convention on Climate Change and the Kyoto Protocol, as well as decision-making at the European level in the context of carbon mitigation in forest ecosystems. This Action is a pioneering attempt to co-ordinate research: to exchange experience and knowledge towards standardised greenhouse gas inventory accounting for forests over Europe. It will match, within four years (1999-2003, both scientific and political agendas. This paper gives a background presentation of the COST E21-Action, its work plan and its clearing house. It finally gives the outline of country specific information to the COST E21 as presented in this issue in a standard format.

  13. Carbon stocks estimates for French forests. COST E21 Workshop. Contribution of forests and forestry to mitigate greenhouse effects. Joensuu (Finland. 28-30 Sep 2000

    Directory of Open Access Journals (Sweden)

    Dupouey J.L.

    2000-01-01

    Full Text Available This paper gives a short description of the data and methods used for inventorying the carbon stocks in the biomass and soil pools in metropolitan French forests. The data concerning the biomass pools are measured by the French National Forest Inventory (NFI while data necessary to estimate the soil carbon pools are obtained from the 16 x 16 km soil inventory of the International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forests in the UN/ECE. Some of the problems raised by the implementation of the Kyoto protocol articles 3.3 and 3.4 in France are discussed and a preliminary estimate of the changes in relevant carbon storage is given.

  14. Agenda 21; Agenda 21

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-03-01

    In the prospect of the Johannesburg international summit in August 2002, the regional council of Midi-Pyrenees region (S France) in partnership with the French ministry of national development and environment has organized a two-days meeting in order to identify and valorize the good practices for the implementation of a sustainable development policy. The basic reference document of this meeting is the 'Agenda 21' program of actions that all governments signatories to the commitments of the Rio summit will have to implement. This document is the complete version in French language of the Agenda 21. It comprises several points dealing with: the environment protection and the abatement of pollution, the management of energy resources with the development of renewable energies, the viable management of the transportation sector, the management of wastes and radioactive wastes, etc.. (J.S.)

  15. Isotopically heavy carbon in C21 to C25 regular isoprenoids in halite-rich deposits from the Sdm Formation, Dead Sea, Israel

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Grice, K.; Schouten, S.; Nissenbaum, A.; Charrach, J.

    1998-01-01

    A series of Miocene/Pliocene halite deposits (with extremely low organic carbon contents) from the Sdom Formation (Dead Sea Basin, Israel) have been studied. Distributions and contents of biomarkers have been determined using GC MS and irm-GCMS analyses, respectively. The hydrocarbon fractions cons

  16. A Tale of Three Mysterious Spectral Features in Carbon-Rich Evolved Stars: The 21 Micrometer, 30 Micrometer, and "Unidentified Infrared" Emission Features

    CERN Document Server

    Mishra, Ajay; Jiang, B W

    2015-01-01

    The mysterious "21 micrometer" emission feature seen almost exclusively in the short-lived protoplanetary nebula (PPN) phase of stellar evolution remains unidentified since its discovery two decades ago. This feature is always accompanied by the equally mysterious, unidentified "30 micrometer" feature and the so-called "unidentified infrared" (UIR) features at 3.3, 6.2, 7.7, 8.6, and 11.3 micrometer which are generally attributed to polycyclic aromatic hydrocarbon (PAH) molecules. The 30 micrometer feature is commonly observed in all stages of stellar evolution from the asymptotic giant branch (AGB) through PPN to the planetary nebula phase. We explore the interrelations among the mysterious 21 micrometer, 30 micrometer, and UIR features in the Galactic and Magellanic Cloud of the 21 micrometer sources. We derive the fluxes emitted in the observed UIR, 21 micrometer, and 30 micrometer features from published ISO or Spitzer/IRS spectra. We find that none of these spectral features correlate with each other. Th...

  17. Possibilities for carbon sequestration in Irish forests. COST E21 Workshop. Contribution of forests and forestry to mitigate greenhouse effects. Joensuu (Finland. 28-30 Sep 2000

    Directory of Open Access Journals (Sweden)

    Byrne K.A.

    2000-01-01

    Full Text Available Ireland has a rapidly expanding forest estate which covers some 9/ of the land area. It is government policy to increase this to 17/ by the year 2030. Preliminary studies suggest that forestry activities have the potential to contribute significantly to the mitigation of greenhouse gas emissions. Although some studies have been carried out the determination of the carbon stores and sinks in Irish forests will require a considerable research effort in the future. A key aspect of such studies will be field based studies which measure all components of the carbon cycle and their relationship to climatic and environmental conditions as well as management practices. Many of these issues will be addressed in the recently announced research programme of the Council for Forest Research and Development (COFORD.

  18. Transient simulations of the carbon and nitrogen dynamics in northern peatlands: from the Last Glacial Maximum to the 21st century

    Directory of Open Access Journals (Sweden)

    R. Spahni

    2013-06-01

    Full Text Available The development of northern high-latitude peatlands played an important role in the carbon (C balance of the land biosphere since the Last Glacial Maximum (LGM. At present, carbon storage in northern peatlands is substantial and estimated to be 500 ± 100 Pg C (1 Pg C = 1015 g C. Here, we develop and apply a peatland module embedded in a dynamic global vegetation and land surface process model (LPX-Bern 1.0. The peatland module features a dynamic nitrogen cycle, a dynamic C transfer between peatland acrotelm (upper oxic layer and catotelm (deep anoxic layer, hydrology- and temperature-dependent respiration rates, and peatland specific plant functional types. Nitrogen limitation down-regulates average modern net primary productivity over peatlands by about half. Decadal acrotelm-to-catotelm C fluxes vary between −20 and +50 g C m−2 yr−1 over the Holocene. Key model parameters are calibrated with reconstructed peat accumulation rates from peat-core data. The model reproduces the major features of the peat core data and of the observation-based modern circumpolar soil carbon distribution. Results from a set of simulations for possible evolutions of northern peat development and areal extent show that soil C stocks in modern peatlands increased by 365–550 Pg C since the LGM, of which 175–272 Pg C accumulated between 11 and 5 kyr BP. Furthermore, our simulations suggest a persistent C sequestration rate of 35–50 Pg C per 1000 yr in present-day peatlands under current climate conditions, and that this C sink could either sustain or turn towards a source by 2100 AD depending on climate trajectories as projected for different representative greenhouse gas concentration pathways.

  19. Transient simulations of the carbon and nitrogen dynamics in northern peatlands: from the Last Glacial Maximum to the 21st century

    Directory of Open Access Journals (Sweden)

    R. Spahni

    2012-11-01

    Full Text Available The development of northern high-latitude peatlands played an important role in the carbon (C balance of the land biosphere since the Last Glacial Maximum (LGM. At present, carbon storage in northern peatlands is substantial and estimated to be 500 ± 100 Pg C (1 Pg C = 1015 g C. Here, we develop and apply a peatland module embedded in a dynamic global vegetation model (LPX. The peatland module features a dynamic nitrogen cycle, a dynamic C transfer between peatland acrotelm (upper oxic layer and catotelm (deep anoxic layer, hydrology- and temperature-dependent respiration rates, and peatland specific plant functional types. Nitrogen limitation down-regulates average modern net primary productivity over peatlands by almost a factor of two. Decadal acrotelm-to-catotelm C fluxes vary between −20 and +50 g C m−2 yr−1 over the Holocene. Key model parameters are calibrated with reconstructed peat accumulation rates from peat-core data. The model reproduces the major features of the peat core data and of the observation-based modern circumpolar soil carbon distribution. Results from a set of simulations for possible evolutions of northern peat development and areal extent show that soil C stocks in modern peatlands increased by 365–550 Pg C since the LGM, of which 175–272 Pg C accumulated between 11 and 5 kyr BP. Furthermore, our simulations suggest a persistent C sequestration rate of 35–50 Pg C per 1000 yr in peatlands under current climate conditions, and that this C sink could either vanish or turn into a small source by 2100 AD depending on climate trajectories as projected for different representative greenhouse gas concentration pathways.

  20. A multi-model study on the Southern Ocean CO2 uptake and the role of the biological carbon pump in the 21st century

    OpenAIRE

    Hauck, Judith; Völker, Christoph; Wolf-Gladrow, Dieter; Laufkötter, Charlotte; Vogt, Meike; Aumont, Olivier; Bopp, Laurent; Buitenhuis, Erik; Doney, Scott; Dunne, John; Gruber, Nicolas; Hashioka, Taketo; John, Jasmin; Le Quéré, Corinne; Lima, Ivan

    2015-01-01

    The Southern Ocean is one of the key regions for global carbon uptake and it is under discussion how physical changes will alter its CO2 balance both directly and indirectly through changes in biological production. Here we analyse a suite of eight RCP8.5 model simulations until 2100 from the MAREMIP and CMIP5 model intercomparison projects on changes in export production and CO2 uptake. We explore how the counter-acting effects of stronger winds ("SAM signal", less stratification) and glo...

  1. Transition probabilities for the 1s21S0-1s2p 3P1 intercombination line in He-like carbon and nitrogen

    International Nuclear Information System (INIS)

    Lifetime measurements are presented for 1s2p 3Psub(1,2) levels for He-like C V and N VI. From the measured lifetimes, transition probabilities are deduced for both allowed and spin-forbidden transitions. The values for the 1s21S0 - 1s2p 3P1 transition rates, 0.29 . 108 and 1.38 . 108 s-1 for C V and N VI respectively, are found to be in good agreement with theory. (orig.)

  2. Carbon dioxide, hydrographic, and chemical data obtained during the R/V Meteor Cruise 11/5 in the South Atlantic and Northern Weddell Sea areas (WOCE sections A-12 and A-21)

    Energy Technology Data Exchange (ETDEWEB)

    Chipman, D.W.; Takahashi, T.; Breger, D.; Sutherland, S.C. [Columbia Univ., Palisades, NY (United States). Lamont-Doherty Earth Observatory; Kozyr, A. [Oak Ridge National Lab., TN (United States). Carbon Dioxide Information Analysis Center]|[Tennessee Univ., Knoxville, TN (United States). Energy, Environment and Resources Center; Gaslightwala, A.F. [Oak Ridge National Lab., TN (United States). Carbon Dioxide Information Analysis Center]|[Cornell Univ., Ithaca, NY (United States)

    1994-07-01

    This document presents the procedures and methods used to obtain carbon dioxide (CO{sub 2}), hydrographic, and chemical data during R/V Meteor Expedition 11/5 in the South Atlantic Ocean, including the Drake Passage; the Northern Weddell Sea; and the Eastern South Atlantic Ocean. This cruise was conducted as part of the World Ocean Circulation Experiment (WOCE). The cruise started from Ushuaia, Argentina, on January 23, 1990, and ended at Capetown, South Africa on March 8, 1990. Samples were collected at 78 stations that covered the Drake Passage; the Northern Weddell Sea; a section along the 58 W parallel; and two segmented S-N sections between the Northern Weddell Sea and Capetown, South Africa. Measurements taken at WOCE sections A-12 and A-21 included pressure, temperature, salinity measured by the Conductivity, Temperature and Depth sensor (CTD); bottle salinity; oxygen; phosphate; nitrate; nitrate; silicate; total carbon concentration (TCO{sub 2}); and partial pressure of CO{sub 2} (pCO{sub 2}) measured at 20 C. In addition, potential density at 0 decibar (dbar) and potential temperature were calculated from the measured variables. The TCO{sub 2} concentration in seawater samples was measured using a coulometer with an estimated precision of approximately {+-} {mu}mol/kg.

  3. Photospheric composition of the carbon-rich 21 micron post-AGB stars IRAS 22223+4327 and IRAS 04296+3429

    CERN Document Server

    Decin, L; Waelkens, C; Bakker, E J; Decin, Leen; Winckel, Hans Van; Waelkens, Christoffel; Bakker, Eric J.

    1998-01-01

    We present a detailed chemical analysis on the basis of high-resolution, high signal-to-noise optical spectra of two post-AGB objects IRAS 22223+4327 and IRAS 04296+3429. Both display the unidentified $21 \\mu m$ feature in their IR-spectra. The spectroscopic indicators provide accurate atmospheric parameters of $T_{eff}$=6500 K, $log g=1.0$ and $\\xi_t = 5.5 km/s$ for IRAS 2223+4327 and $T_{eff}$=7000 K, $log g=1.0$ and $\\xi_t = 4.0 km/s$ for IRAS 04296+3429. Both photospheres are found to be metal-deficient with [Fe/H]= -0.4 and -0.7 respectively. C and N are found to be overabundant. The mean abundance of all the measured s-process-elements is [s/Fe]=+1.0 for IRAS 2223+4327 and +1.4 for IRAS 04296+3429. The distribution of the s-process elements can best be described as due to a distribution of neutron exposures with a low mean neutron exposure of $\\tau_{0} = 0.2 mbarn^{-1}$. The 21 $\\mu$m stars form an interesting sub-group in the total post-AGB sample of stars, not only for their IR characteristics, but al...

  4. β-alumina-14H and β-alumina-21R: Two chromic Na2-δ(Al,Mg,Cr)17O25 polysomes observed in slags from the production of low-carbon ferrochromium

    Science.gov (United States)

    Hejny, Clivia; Kahlenberg, Volker; Schmidmair, Daniela; Tribus, Martina; deVilliers, Johan

    2016-09-01

    The crystal structures of unknown phases found in slags from the production of low-carbon ferrochromium were studied by powder and single-crystal X-ray diffraction. Two phases of Na2-δ(Al, Mg, Cr)17O25 composition were found to be composed of an alternating stacking of a spinel-type and a Na-hosting block. Similar structures are known for β-alumina and β"-alumina, NaAl11O17. However, the spinel-type block in Na2-δ(Al, Mg, Cr)17O25 is composed of five cation layers in contrast to three cation layers in the β-alumina spinel-block. The two new phases, β-alumina-14H, P63/mmc, a=5.6467(2), c=31.9111(12) Å, and β-alumina-21R, R 3 ̅m, a=5.6515(3), c=48.068(3) Å have a 14-layer and 21-layer stacking with a 2 × (cccccch) and a 3 × (ccccccc) repeat sequence of oxygen layers in cubic and hexagonal close packing, respectively.

  5. SDSS J000555.90-100213.5: a hot, magnetic carbon-atmosphere WD rotating with a 2.1 day period

    CERN Document Server

    Lawrie, K A; Dufour, P; Hodgkin, S T

    2013-01-01

    A surprisingly large fraction (70%) of hot, carbon dominated atmosphere (DQ) white dwarfs are magnetic and/or photometrically variable on short timescales up to ~1000 s. However, here we show that the hot DQ magnetic white dwarf SDSS J000555.90-100213.5 is photometrically variable by 11% on a longer timescale, with a period of 2.110 +/- 0.045 days. We find no evidence of the target fluctuating on short timescales at an amplitude of <+/-0.5%. Short period hot DQ white dwarfs have been interpreted as non-radial pulsators, but in the case of SDSS J0005-1002, it is more likely that the variability is due to the magnetic hot DQ white dwarf rotating. We suggest that some hot DQ white dwarfs, varying on short timescales, should be more carefully examined to ascertain whether the variability is due to rotation rather than pulsation. All hot DQs should be monitored for long period modulations as an indicator of rotation and magnetism.

  6. Carbon Carbon Composites: An Overview .

    OpenAIRE

    G. Rohini Devi; K. Rama Rao

    1993-01-01

    Carbon carbon composites are a new class of engineering materials that are ceramic in nature but exhibit brittle to pseudoplastic behaviour. Carbon-carbon is a unique all-carbon composite with carbon fibre embeded in carbon matrix and is known as an inverse composite. Due to their excellent thermo-structural properties, carbon-carbon composites are used in specialised application like re-entry nose-tips, leading edges, rocket nozzles, and aircraft brake discs apart from several indust...

  7. Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from time series observations using Bubble type equilibrator for autonomous carbon dioxide (CO2) measurement, Carbon dioxide (CO2) gas analyzer and other instruments from MOORINGS in the Caribbean Sea from 2010-01-21 to 2012-11-26 (NODC Accession 0117354)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0117354 includes time series data collected from MOORINGS in the Caribbean Sea from 2010-01-21 to 2012-11-26 and retrieved during cruise...

  8. Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Carbon dioxide (CO2) gas analyzer and other instruments from the LAURENCE M. GOULD in the South Atlantic Ocean from 2006-03-21 to 2006-04-04 (NODC Accession 0108070)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0108070 includes chemical, discrete sample, physical and profile data collected from LAURENCE M. GOULD in the South Atlantic Ocean from 2006-03-21 to...

  9. 27 CFR 21.127 - Shellac (refined).

    Science.gov (United States)

    2010-04-01

    ... Section 21.127 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... A—5 ml of phenol dissolved in 10 ml of carbon tetrachloride. Solution B—1 ml of bromine dissolved in 4 ml of carbon tetrachloride. To the residue obtained above add 2 ml of Solution A and transfer...

  10. 21 CFR 184.1736 - Sodium bicarbonate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium bicarbonate. 184.1736 Section 184.1736 Food... Specific Substances Affirmed as GRAS § 184.1736 Sodium bicarbonate. (a) Sodium bicarbonate (NaHCO3, CAS Reg. No. 144-55-8) is prepared by treating a sodium carbonate or a sodium carbonate and sodium...

  11. Carbon Carbon Composites: An Overview .

    Directory of Open Access Journals (Sweden)

    G. Rohini Devi

    1993-10-01

    Full Text Available Carbon carbon composites are a new class of engineering materials that are ceramic in nature but exhibit brittle to pseudoplastic behaviour. Carbon-carbon is a unique all-carbon composite with carbon fibre embeded in carbon matrix and is known as an inverse composite. Due to their excellent thermo-structural properties, carbon-carbon composites are used in specialised application like re-entry nose-tips, leading edges, rocket nozzles, and aircraft brake discs apart from several industrial and biomedical applications. The multidirectional carbon-carbon product technology is versatile and offers design flexibility. This paper describes the multidirectional preform and carbon-carbon process technology and research and development activities within the country. Carbon-carbon product experience at DRDL has also been discussed. Development of carbon-carbon brake discs process technology using the liquid impregnation process is described. Further the test results on material characterisation, thermal, mechanical and tribological properties are presented.

  12. Carbon Dioxide, Hydrographic, and Chemical Data Obtained During the R/V John V. Vickers Cruise in the Pacific Ocean (WOCE Section P13, NOAA CGC92 Cruise, August 4 - October 21, 1992)

    Energy Technology Data Exchange (ETDEWEB)

    Kozyr, A.

    2001-01-11

    This data documentation discusses the procedures and methods used to measure total carbon dioxide (TCO{sub 2}) and total alkalinity (TALK) at hydrographic stations during the R/V John V. Vickers oceanographic cruise in the Pacific Ocean (Section P13). Conducted as part of the World Ocean Circulation Experiment (WOCE) and the National Oceanic and Atmospheric Administration's Climate and Global Change Program, the cruise began in Los Angeles, California, on August 4, 1992, with a transit line (Leg 0) to Dutch Harbor, Alaska. On August 16, the ship departed Dutch Harbor on Leg 1 of WOCE section P13. On September 15, the R/V John V. Vickers arrived in Kwajalein, Marshall Islands, for emergency repairs, and after 11 days in port departed for Leg 2 of Section P13 on September 26. The cruise ended on October 21 in Noumea, New Caledonia. Measurements made along WOCE Section P13 included pressure, temperature, salinity [measured by a conductivity, temperature, and depth sensor (CTD)], bottle salinity, bottle oxygen, phosphate, nitrate, nitrite, silicate, chlorofluorocarbons (CFC-11, CFC-12), TCO{sub 2} , and TALK. The TCO{sub 2} was measured by coulometry using a Single-Operator Multiparameter Metabolic Analyzer (SOMMA). The overall precision and accuracy of the analyses was {+-}2 {micro}mol/kg. Samples collected for TALK were measured by potentiometric titration; precision was {+-}2 {micro}mol/kg. The CO{sub 2} -related measurements aboard the R/V John V. Vickers were supported by the U.S. Department of Energy. The WOCE Section P13 data set is available free of charge as a numeric data package (NDP) from the Carbon Dioxide Information Analysis Center. The NDP consists of two oceanographic data files, two FORTRAN 90 data-retrieval routine files, a documentation file, and this printed report, which describes the contents and format of all files as well as the procedures and methods used to obtain the data. Instructions on how to access the data are provided.

  13. ARCHI21

    DEFF Research Database (Denmark)

    Hunter, Moira; Chase, Scott Curland; Kligerman, Bradley;

    2011-01-01

    This paper offers insights into innovative practice being undertaken in higher architectural and design education, where both language and content teaching and learning are integrated as interwoven parts with joint curricular roles. Using Expansive Learning Theory as an analytical framework...... face-to-face learning-teaching scenarios were supported by immersive 3D virtual environments together with social networking media and Web 2.0 tools. This paper uses these pilot studies to speculate on aspects of fragility and offers reflection on future project activity....... to examine potential tensions and contradictions arising from the educational approach of Content and Language Integrated Learning, reference is made to three very recent pilot studies of the EU funded project, ARCHI21. The experiential learning in these studies adopted a blended approach, where classical...

  14. 21 CFR 1210.21 - Permit number.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Permit number. 1210.21 Section 1210.21 Food and... IMPORT MILK ACT Permit Control § 1210.21 Permit number. Each permit issued under the Federal Import Milk Act, including each temporary permit, shall bear an individual number. The right to the use of...

  15. Observations of carbon dioxide in the surface waters of the Eastern North Pacific Ocean and the Bering Sea from 21 July 1968 to 03 September 1968 (NODC Accession 7100114)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Measurements of the equilibrium concentration of carbon dioxide in the air and surface waters of the North Pacific Ocean and the Bering Sea are presented....

  16. National forest inventory of Finland and its role estimating the carbon balance forests. COST E21 Workshop. Contribution of forests and forestry to mitigate greenhouse effects. Joensuu (Finland. 28-30 Sep 2000

    Directory of Open Access Journals (Sweden)

    Tomppo E.

    2000-01-01

    Full Text Available The paper presents the total stem volume increment and total drain, as well as the corresponding carbon contents, of the trees of Finnish forests. The carbon contents are converted to carbon dioxide equivalents. The total increment is above stump stem wood volume increment including bark. The estimates come from the National Forest Inventory of Finland conducted by the Finnish Forest Research Institute. The method is briefly described. The total drain includes fellings, i.e. removals and cutting waste, as well as natural mortality of above stump stem wood volume of trees including bark. The above stump stem volumes are converted to total tree biomass, total dry matter and total carbon content using available coefficients.

  17. Possibilities for carbon sequestration by the forestry sector in Hungary. COST E21 Workshop. Contribution of forests and forestry to mitigate greenhouse effects. Joensuu (Finland. 28-30 Sep 2000

    Directory of Open Access Journals (Sweden)

    Somogyi Z.

    2000-01-01

    Full Text Available In Hungary, gross emissions of carbon amount to some 17.6 millions t C per year. Forestry, the only sector which can offset emissions, seems to be a net sink of 1.6 Mt C per year. Afforesting large areas could substantially increase the carbon fixing capacity of the Hungarian forests. To assess the possibilities of sequestering carbon by afforestation, the CASFOR model, an adaptation of the COMAP model, was developed for Hungarian conditions. The technical potential scenario showed that, by afforesting 773,000 ha of former agricultural land by 2050, some 46 millions t C could be sequestered. The specific costs of sequestering carbon by afforestation are pretty low.

  18. Double-walled carbon nanotubes synthesized using carbon black as the dot carbon source

    Science.gov (United States)

    Chen, Zhi-Gang; Li, Feng; Ren, Wen-Cai; Cong, Hongtao; Liu, Chang; Qing Lu, Gao; Cheng, Hui-Ming

    2006-07-01

    Double-walled carbon nanotubes (DWNTs) were synthesized used carbon black as the dot carbon source by a semi-continuous hydrogen arc discharge process. High-resolution transmission electron microscopy (HRTEM) observations revealed that most of the tubes were DWNTs with outer and inner diameters in the range of 2.67-4 nm and 1.96-3.21 nm, respectively. Most of the DWNTs were in a bundle form of about 10-30 nm in diameter with high purity (about 70%) from thermal gravimetric analysis (TGA), resonant laser Raman spectroscopy, scanning electron microscopy (SEM) and TEM characterizations. It was found that carbon black as the dot carbon source could be easy controlled to synthesize one type of nanotube. A simple process combining oxidation and acid treatment to purify the DWNT bundles was used without damaging the bundles. The structure of carbon black, as the key element for influencing purity, bundle formation and purification of DWNTs, is discussed.

  19. 21 CFR 17.21 - Prehearing conferences.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Prehearing conferences. 17.21 Section 17.21 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL CIVIL MONEY...; (3) Stipulations and admissions of fact as to the contents and authenticity of documents; (4)...

  20. 21 CFR 184.1763 - Sodium hydroxide.

    Science.gov (United States)

    2010-04-01

    ... solution and also by reacting calcium hydroxide with sodium carbonate. (b) The ingredient meets the... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium hydroxide. 184.1763 Section 184.1763 Food... Specific Substances Affirmed as GRAS § 184.1763 Sodium hydroxide. (a) Sodium hydroxide (NaOH, CAS Reg....

  1. 21 CFR 184.1443 - Magnesium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium sulfate. 184.1443 Section 184.1443 Food... Specific Substances Affirmed as GRAS § 184.1443 Magnesium sulfate. (a) Magnesium sulfate (MgSO4·7H2O, CAS... magnesium oxide, hydroxide, or carbonate with sulfuric acid and evaporating the solution to...

  2. Anthropogenic perturbation of the global carbon cycle as a result of agricultural carbon erosion and burial

    Science.gov (United States)

    Wang, Zhengang; Govers, Gerard; Kaplan, Jed; Hoffmann, Thomas; Doetterl, Sebastian; Six, Johan; Van Oost, Kristof

    2016-04-01

    Changes in terrestrial carbon storage exert a strong control over atmospheric CO2 concentrations but the underlying mechanisms are not fully constrained. Anthropogenic land cover change is considered to represent an important carbon loss mechanism, but current assessments do not consider the associated acceleration of carbon erosion and burial in sediments. We evaluated the role of anthropogenic soil erosion and the resulting carbon fluxes between land and atmosphere from the onset of agriculture to the present day. We show, here, that agricultural erosion induced a significant cumulative net uptake of 198±57 Pg carbon on terrestrial ecosystems. This erosion-induced soil carbon sink is estimated to have offset 74±21% of carbon emissions. Since 1850, erosion fluxes have increased 3-fold. As a result, the erosion and lateral transfer of organic carbon in relation to human activities is an important driver of the global carbon cycle at millennial timescales.

  3. Carbon sequestration by afforestation and revegetation as a means of limiting net-CO2 emissions in Iceland. COST E21 Workshop. Contribution of forests and forestry to mitigate greenhouse effects. Joensuu (Finland. 28-30 Sep 2000

    Directory of Open Access Journals (Sweden)

    Sigurdsson B.D.

    2000-01-01

    Full Text Available Iceland has lost about 95/ of its woodlands and 50/ of its vegetative cover during the 1,100 years of human settlement. Efforts to reclaim lost woodlands and herbaceous ecosystems have been continuing since the early 20th century. It is emphasised that for Icelandic conditions, effective carbon sequestration can be achieved by restoring (reclaiming herbaceous ecosystems on carbon-poor soils. Since 1990, about 4,000 ha per year have been afforested or revegetated. In 1995, the estimated C-sequestration of those areas was 65,100 t CO2, or 2.9/ of the national emissions for that year. In 1999, the estimated sequestration was up in 127,600 t CO2, or 4.7/ of the predicted CO2 emissions for the year 2000.

  4. Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from the KNORR in the South Pacific Ocean from 2005-08-21 to 2005-10-06 (NODC Accession 0108071)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0108071 includes chemical, discrete sample, physical and profile data collected from KNORR in the South Pacific Ocean from 2005-08-21 to 2005-10-06...

  5. 21 CFR 26.21 - Safeguard clause.

    Science.gov (United States)

    2010-04-01

    ... OF PHARMACEUTICAL GOOD MANUFACTURING PRACTICE REPORTS, MEDICAL DEVICE QUALITY SYSTEM AUDIT REPORTS... Specific Sector Provisions for Pharmaceutical Good Manufacturing Practices § 26.21 Safeguard clause....

  6. The Swiss carbon balance: methods, state of reporting and research perspectives. COST E21 Workshop. Contribution of forests and forestry to mitigate greenhouse effects. Joensuu (Finland). 28-30 Sep 2000.

    OpenAIRE

    Bugmann H.

    2000-01-01

    For the 1990-1998 period, Switzerland reported an annual sink strength of Swiss forests of 4500-6000 Gg CO2. In its latest submission in 2000, newly available national forest inventory (NFI) data were used to refine earlier estimates. The same NFI data can also be used to provide extrapolations for the near future. No carbon sequestration values have been reported to date for forest soils. The Swiss government will provide funding for a number of research activities under the umbrella of COST...

  7. Carbon stocks and sinks in forestry for the unitéd Kingdom greenhouse gas inventory. COST E21 Workshop. Contribution of forests and forestry to mitigate greenhouse effects. Joensuu (Finland). 28-30 Sep 2000

    OpenAIRE

    Milne R.; Hargreaves K.; Murray M.

    2000-01-01

    Afforestation in the UK has been significant and continuing since 1920 (up to 30,000 ha per year). Planting data is used to drive a dynamic process-based carbon accounting model (C-Flow) to estimate removals of atmospheric CO2 to these forests. It is assumed that the afforestation can be represented by the characteristics of Sitka spruce for conifers and beech for broadleaves. The present area of forest considered for these estimates is 1.6 millions ha. In 1990 the uptake to trees, litter, so...

  8. Porous carbons

    Indian Academy of Sciences (India)

    Satish M Manocha

    2003-02-01

    Carbon in dense as well as porous solid form is used in a variety of applications. Activated porous carbons are made through pyrolysis and activation of carbonaceous natural as well as synthetic precursors. Pyrolysed woods replicate the structure of original wood but as such possess very low surface areas and poor adsorption capacities. On activation, these exhibit increased adsorption volumes of 0.5–0.8 cm3 /gm and surface areas of 700–1800 m2 /gm depending on activation conditions, whether physical or chemical. Former carbons possess mixed pore size distribution while chemically activated carbons predominantly possess micropores. Thus, these carbons can be used for adsorption of wide distributions of molecules from gas to liquid. The molecular adsorption within the pores is due to single layer or multilayer molecule deposition at the pore walls and hence results in different types of adsorption isotherm. On the other hand, activated carbon fibres with controlled microporous structure and surface area in the range of 2500 m2 /gm can be developed by controlled pyrolysis and physical activation of amorphous carbon fibres. Active carbon fibres with unmatchable pore structure and surface characteristics are present and futuristic porous materials for a number of applications from pollution control to energy storage.

  9. Main: REBETALGLHCB21 [PLACE

    Lifescience Database Archive (English)

    Full Text Available Lhcb21 gene promoter; Located at -114 to -109; A GATA sequence created at a position six nucleotides upstre...REBETALGLHCB21 S000363 16-Feb-2001 (last modified) seki REbeta found in Lemna gibba

  10. Mexico and the 21st Century Power Partnership (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2015-02-01

    The 21st Century Power Partnership's program in Mexico (21CPP Mexico) is one initiative of the Clean Energy Ministerial, carried out in cooperation with government and local stakeholders, drawing upon an international community of power system expertise. The overall goal of this program is to support Mexico's power system transformation by accelerating the transition to a reliable, financially robust, and low-carbon system. 21CPP Mexico activities focus on achieving positive outcomes for all participants, especially addressing critical questions and challenges facing policymakers, regulators, and system operators. In support of this goal, 21CPP Mexico taps into deep networks of expertise and professional connections.

  11. Calcium Carbonate

    Science.gov (United States)

    ... before being swallowed; do not swallow them whole. Drink a full glass of water after taking either the regular or chewable tablets or capsules. Some liquid forms of calcium carbonate must be shaken well before use.Do not ...

  12. Carbon Stars

    Indian Academy of Sciences (India)

    T. Lloyd Evans

    2010-12-01

    In this paper, the present state of knowledge of the carbon stars is discussed. Particular attention is given to issues of classification, evolution, variability, populations in our own and other galaxies, and circumstellar material.

  13. Zero-Carbon Energy Kyoto 2011 : Special Edition of Jointed Symposium of Kyoto University Global COE “Energy Science in the Age of Global Warming” and Ajou University BK21

    CERN Document Server

    2012-01-01

    The nuclear plant accident at Fukushima in the wake of the Great East Japan Earthquake and tsunami has had a major impact on the energy strategy of Japan and the world. From a global perspective, approach to energy is of greater and greater consequence. The Global Center of Excellence (COE) Program of the Ministry of Education, Culture, Sports, Science and Technology of Japan, with the support of university faculty members, has established an international education and research platform to foster educators, researchers, and policy makers who can develop technologies and propose policies for establishing a CO2 zero-emission society no longer dependent on fossil fuels by the year 2100. Since 2008, a program called “Energy Science in the Age of Global Warming—Toward a CO2 Zero-Emission Energy System” has been in progress at Kyoto University. A third international symposium, titled “Zero-Carbon Energy, Kyoto 2011,” was held jointly with Ajou University, Korea, in August 2011, and this book is a compila...

  14. Carbon stocks and sinks in forestry for the unitéd Kingdom greenhouse gas inventory. COST E21 Workshop. Contribution of forests and forestry to mitigate greenhouse effects. Joensuu (Finland. 28-30 Sep 2000

    Directory of Open Access Journals (Sweden)

    Milne R.

    2000-01-01

    Full Text Available Afforestation in the UK has been significant and continuing since 1920 (up to 30,000 ha per year. Planting data is used to drive a dynamic process-based carbon accounting model (C-Flow to estimate removals of atmospheric CO2 to these forests. It is assumed that the afforestation can be represented by the characteristics of Sitka spruce for conifers and beech for broadleaves. The present area of forest considered for these estimates is 1.6 millions ha. In 1990 the uptake to trees, litter, soil and products was 2.6 terragramme C, rising to 2.8 terragramme C in 1998. Deforestation is believed to be small. Supporting measurements show that the model predicts long term uptake by conifers well but that losses from planted peat shortly after establishment need further consideration. Process modelling of beech growth suggests that it is primarily dependant on atmospheric CO2 concentration and not on stomatal control per se. UK research priorities relevant to preparation of GHG (greenhouse gas Inventories are presented.

  15. 21 CFR 184.1210 - Calcium oxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium oxide. 184.1210 Section 184.1210 Food and... Substances Affirmed as GRAS § 184.1210 Calcium oxide. (a) Calcium oxide (CaO, CAS Reg. No. 1305-78-8) is also known as lime, quick lime, burnt lime, or calx. It is produced from calcium carbonate, limestone,...

  16. Difference in brain distributions of carbon 11-labeled 4-hydroxy-2(1H)-quinolones as PET radioligands for the glycine-binding site of the NMDA ion channel

    Energy Technology Data Exchange (ETDEWEB)

    Fuchigami, Takeshi [Graduate School of Pharmaceutical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582 (Japan); Photon Medical Research Center, Hamamatsu University School of Medicine, Hamamatsu 431-3192 (Japan); Haradahira, Terushi [Molecular Imaging Center, National Institute of Radiological Sciences, Inage-ku, Chiba 263-8555 (Japan)], E-mail: terushi@niu.ac.jp; Fujimoto, Noriko [Graduate School of Pharmaceutical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582 (Japan); Okauchi, Takashi; Maeda, Jun; Suzuki, Kazutoshi; Suhara, Tetsuya [Molecular Imaging Center, National Institute of Radiological Sciences, Inage-ku, Chiba 263-8555 (Japan); Yamamoto, Fumihiko; Sasaki, Shigeki; Mukai, Takahiro [Graduate School of Pharmaceutical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582 (Japan); Yamaguchi, Hiroshi [Molecular Imaging Frontier Research Center, Hamamatsu University School of Medicine, Hamamatsu 431-3192 (Japan); Ogawa, Mikako [Photon Medical Research Center, Hamamatsu University School of Medicine, Hamamatsu 431-3192 (Japan); Magata, Yasuhiro [Photon Medical Research Center, Hamamatsu University School of Medicine, Hamamatsu 431-3192 (Japan); Molecular Imaging Frontier Research Center, Hamamatsu University School of Medicine, Hamamatsu 431-3192 (Japan); Maeda, Minoru [Graduate School of Pharmaceutical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582 (Japan)

    2008-02-15

    High-affinity iodine- and ethyl-C-5 substituted analogs of 4-hydroxy-3-(3-[{sup 11}C]methoxyphenyl)-2(1H)-quinolone ([{sup 11}C]4HQ) were synthesized as new positron emission tomography radioligands for the glycine-binding sites of the N-methyl-D-aspartate (NMDA) ion channel. Although both radioligands showed high in vitro specific binding to rat brain slices, their binding characteristics were quite different from each other. 5-Ethyl-[{sup 11}C]4HQ (5Et-[{sup 11}C]4HQ) showed higher in vitro binding in the forebrain regions than in the cerebellum, bindings that were strongly inhibited by both glycine-site agonists and antagonists. In contrast, 5-iodo-[{sup 11}C]4HQ (5I-[{sup 11}C]4HQ) showed a homogeneous in vitro binding throughout the brain, which was inhibited by antagonists but not by agonists. This difference in in vitro binding between 5Et-[{sup 11}C]4HQ and 5I-[{sup 11}C]4HQ was quite similar to that previously observed between [{sup 11}C]L-703,717 and [{sup 11}C]4HQ, both glycine-site antagonists. In vivo brain uptakes of these {sup 11}C-labeled 4-hydroxyquinolones were examined in mice. Initial brain uptakes of 5Et- and 5I-[{sup 11}C]4HQ at 1 min after intravenous injections were comparable to that of [{sup 11}C]4HQ, but they were 1.3-2.1 times higher than that of [{sup 11}C]L-703,717. The treatment with an anticoagulant, warfarin, only slightly increased the initial uptakes of [{sup 11}C]4HQ and 5Et-[{sup 11}C]4HQ in contrast to [{sup 11}C]L-703,717. The in vivo regional brain distributions were slightly different between the two radioligands. Pretreatment with nonradioactive ligand (2 mg/kg) slightly inhibited the binding of 5Et-[{sup 11}C]4HQ (16-36% inhibition) but not that of 5I-[{sup 11}C]4HQ. In this study, it was found that a small structural change in [{sup 11}C]4HQ resulted in a major change in binding characteristics and distributions, suggesting the existence of two binding sites for [{sup 11}C]4-hydroxyquinolones on the NMDA ion channel

  17. Carbon recycling in ophiolite-hosted carbonates, Oman-UAE

    Science.gov (United States)

    Stephen, A.; Jenkin, G. R.; Smith, D. J.; Styles, M. T.; Naden, J.; Boyce, A. J.; Bryant, C. L.

    2013-12-01

    Large-scale surface and subsurface freshwater carbonate deposits of probable Quaternary age have formed on the Oman-UAE ophiolite. Here, serpentinisation reactions in ultramafic rocks have produced calcite and magnesite. These carbonates are frequently cited as examples of natural atmospheric CO2 sequestration, but the possibility of carbon recycling has not been addressed. The aim of this study is to assess the degree of atmospheric CO2 being incorporated into carbonates versus that which has been recycled from alternative sources such as soil CO2, or limestones that underlie the ophiolite. This has been determined through δ13C/δ18O, 87Sr/86Sr and 14C analysis of all major carbonate lithofacies identified. Our analyses of modern carbonate crusts forming on the surface of stagnant hyperalkaline (pH >11) waters show highly depleted δ13C and δ18O values (-25.5‰ ×0.5 PDB and -16.8‰ ×0.5 PDB respectively). This depletion has been attributed to a kinetic isotope effect occurring during atmospheric CO2 exchange with Ca(OH)2 hyperalkaline waters [1]. By comparison, inactive travertine deposits show a large range in δ13C (-10.5 to -21.8‰ PDB) which lies on a trajectory from the composition of modern crusts towards bicarbonate fluids in equilibrium with soil CO2. We interpret this trend as being produced by the mixing of different carbon sources, either at the time of formation or during later alteration. Modern carbonates and inactive travertines also have 87Sr/86Sr ratios and Sr concentrations similar to Cretaceous and Tertiary limestones which surround the ophiolite, whilst subsurface veins also display 87Sr/86Sr ratios similar to these Cretaceous limestones. Carbon recycling can also be determined with 14C. Modern atmospheric CO2 has a global average of 105-106% modern 14C (pMC), therefore freshwater carbonates forming solely from atmospheric CO2 would be expected to contain >100 pMC. However, modern carbonates display varied results from 94.5-101.4 p

  18. SW21 Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Juarez, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-02-10

    Los Alamos and Lawrence Livermore National Laboratories hosted the tenth annual Strategic Weapons in the 21st Century Conference (SW21) on 21 January 2016 to reinforce the national commitment to leadership and institutional excellence for nuclear deterrence. The event has been successful over the years in drawing together a diverse, high-level group of policy makers and experts from multiple disciplines to engage in informed dialogue on topics related to strategic weapons in national and international security.

  19. South Africa and the 21st Century Power Partnership (Fact Sheet). 21st Century Power Partnership; 21st Century Power Partnership

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-04-16

    Established in 2012, the 21CPP South Africa Programme is a global initiative that connects South African stakeholders with an international community of expertise. The overall goal of this program is to support South Africa’s power system transformation by accelerating the transition to a reliable, financially robust, and low-carbon power system. 21CPP activities focus on achieving positive outcomes for all participants, especially addressing critical questions and challenges facing system planners, regulators, and operators. In support of this goal, 21CPP taps into deep networks of expertise among leading industry practitioners.

  20. CARBONIZER TESTS WITH LAKELAND FEEDSTOCKS

    Energy Technology Data Exchange (ETDEWEB)

    C. Lu; Z. Fan; R. Froehlich; A. Robertson

    2003-09-01

    Research has been conducted under United States Department of Energy Contract (USDOE) DE-AC21-86MC21023 to develop a new type of coal-fired plant for electric power generation. This new type of plant, called a Second Generation Pressurized Fluidized Bed Combustion Plant (2nd Gen PFB), offers the promise of efficiencies greater than 48%, with both emissions and a cost of electricity that are significantly lower than those of conventional pulverized coal-fired (PC) plants with wet flue gas desulfurization/scrubbers. The 2nd Gen PFB plant incorporates the partial gasification of coal in a carbonizer, the combustion of carbonizer char in a pressurized circulating fluidized (PCFB) bed boiler, and the combustion of carbonizer syngas in a topping combustor to achieve gas turbine inlet temperatures of 2700 F and higher. Under the USDOE Clean Coal V Demonstration Plant Program, a nominal 260 MWe plant demonstrating 2nd Gen PFB technology has been proposed for construction at the McIntosh Power Plant of the City of Lakeland, Florida. In the September-December 1997 time period, four test runs were conducted in Foster Wheeler's 12-inch diameter carbonizer pilot plant in Livingston New Jersey to ascertain carbonizer performance characteristics with the Kentucky No. 9 coal and Florida limestone proposed for use in the Lakeland plant. The tests were of a short-term nature exploring carbonizer carbon conversions, sulfur capture efficiencies and syngas alkali levels. The tests were successful; observed carbonizer performance was in agreement with predictions and no operating problems, attributed to the planned feedstocks, were encountered. The results of the four test runs are reported herein.

  1. New Routes Towards Nanoporous Carbon Materials for Electrochemical Energy Storage and Gas Adsorption

    OpenAIRE

    Oschatz, Martin

    2015-01-01

    The chemical element carbon plays a key role in the 21st century. “The new carbon age” is associated with the global warming due to increasing carbon dioxide emissions. The latter are a major consequence of the continued combustion of fossil fuels for energy generation. However, carbon is also one key component to overcome these problems. Especially porous carbon materials are highly attractive for many environmentally relevant applications. These materials provide high specific surface area,...

  2. Bioenergy, the Carbon Cycle, and Carbon Policy

    Science.gov (United States)

    Kammen, D. M.

    2003-12-01

    The evolving energy and land-use policies across North America and Africa provide critical case studies in the relationship between regional development, the management of natural resources, and the carbon cycle. Over 50 EJ of the roughly 430 EJ total global anthropogenic energy budget is currently utilized in the form of direct biomass combustion. In North America 3 - 4 percent of total energy is derived from biomass, largely in combined heat and power (CHP) combustion applications. By contrast Africa, which is a major consumer of 'traditional' forms of biomass, uses far more total bioenergy products, but largely in smaller batches, with quantities of 0.5 - 2 tons/capita at the household level. Several African nations rely on biomass for well over 90 percent of household energy, and in some nations major portions of the industrial energy supply is also derived from biomass. In much of sub-Saharan Africa the direct combustion of biomass in rural areas is exceeded by the conversion of wood to charcoal for transport to the cities for household use there. There are major health, and environmental repercussions of these energy flows. The African, as well as Latin American and Asian charcoal trade has a noticeable signature on the global greenhouse gas cycles. In North America, and notably Scandinavia and India as well, biomass energy and emerging conversion technologies are being actively researched, and provide tremendous opportunities for the evolution of a sustainable, locally based, energy economy for many nations. This talk will examine aspects of these current energy and carbon flows, and the potential that gassification and new silvicultural practices hold for clean energy systems in the 21st century. North America and Africa will be examined in particular as both sources of innovation in this field, and areas with specific promise for application of these energy technologies and biomass/land use practices to further energy and global climate management.

  3. Standardisation of gas mixtures for estimating carbon monoxide transfer factor.

    OpenAIRE

    Kendrick, A. H.; Laszlo, G.

    1993-01-01

    BACKGROUND--The American Thoracic Society recommends that the inspired concentration used for the estimation of carbon monoxide transfer factor (TLCO) mixture should be 0.25-0.35% carbon monoxide, 10-14% helium, 17-21% oxygen, balance nitrogen. Inspired oxygen influences alveolar oxygen and hence carbon monoxide uptake, such that transfer factor increases by 0.35% per mm Hg decrease in alveolar oxygen. To aid in the standardisation of TLCO either a known inspired oxygen concentration should b...

  4. Unburned carbon in combustion residues from mainly solid biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Bjurstroem H; Lind B; Lagerkvist A

    2012-02-15

    Unburned carbon in 21 combustion residues from solid biofuels is investigated using several methods of analysis (a.o. LOI and TOC), as well as micro-Raman spectroscopy. The results are used to discuss the distribution of unburned carbon in the residues from the different combustion plants and its nature (organic or elemental). The consequences of the elemental nature of carbon for environmental properties of the residue are noted

  5. Synthesis of carbon-14 labeled doxylamine succinate

    International Nuclear Information System (INIS)

    Doxylamine succinate, N,N-dimethyl-2-[1-phenyl-1-(2-pyridinyl)-ethoxy]ethanamine succinate is an antihistamine used primarily as a sedative. Carbon-14 labeled doxylamine succinate, required for toxicological studies, was synthesized in two steps starting from 2-benzoyl pyridine. (author)

  6. Main: REALPHALGLHCB21 [PLACE

    Lifescience Database Archive (English)

    Full Text Available inding activity is high in etiolated plants but much lower in green plants; Required for phytochrome regulation; See S000363; REalpha; Lhcb21; phytochrome; REbeta; Lemna gibba AACCAA ...

  7. 21 CFR 884.4550 - Gynecologic surgical laser.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Gynecologic surgical laser. 884.4550 Section 884....4550 Gynecologic surgical laser. (a) Identification. A gynecologic surgical laser is a continuous wave carbon dioxide laser designed to destroy tissue thermally or to remove tissue by radiant light...

  8. Aquatic carbon cycling in the conterminous United States and implications for terrestrial carbon accounting.

    Science.gov (United States)

    Butman, David; Stackpoole, Sarah; Stets, Edward; McDonald, Cory P; Clow, David W; Striegl, Robert G

    2016-01-01

    Inland water ecosystems dynamically process, transport, and sequester carbon. However, the transport of carbon through aquatic environments has not been quantitatively integrated in the context of terrestrial ecosystems. Here, we present the first integrated assessment, to our knowledge, of freshwater carbon fluxes for the conterminous United States, where 106 (range: 71-149) teragrams of carbon per year (TgC⋅y(-1)) is exported downstream or emitted to the atmosphere and sedimentation stores 21 (range: 9-65) TgC⋅y(-1) in lakes and reservoirs. We show that there is significant regional variation in aquatic carbon flux, but verify that emission across stream and river surfaces represents the dominant flux at 69 (range: 36-110) TgC⋅y(-1) or 65% of the total aquatic carbon flux for the conterminous United States. Comparing our results with the output of a suite of terrestrial biosphere models (TBMs), we suggest that within the current modeling framework, calculations of net ecosystem production (NEP) defined as terrestrial only may be overestimated by as much as 27%. However, the internal production and mineralization of carbon in freshwaters remain to be quantified and would reduce the effect of including aquatic carbon fluxes within calculations of terrestrial NEP. Reconciliation of carbon mass-flux interactions between terrestrial and aquatic carbon sources and sinks will require significant additional research and modeling capacity.

  9. Aquatic carbon cycling in the conterminous United States and implications for terrestrial carbon accounting

    Science.gov (United States)

    Butman, David; Stackpoole, Sarah; Stets, Edward; McDonald, Cory P.; Clow, David W.; Striegl, Robert G.

    2016-01-01

    Inland water ecosystems dynamically process, transport, and sequester carbon. However, the transport of carbon through aquatic environments has not been quantitatively integrated in the context of terrestrial ecosystems. Here, we present the first integrated assessment, to our knowledge, of freshwater carbon fluxes for the conterminous United States, where 106 (range: 71–149) teragrams of carbon per year (TgC⋅y−1) is exported downstream or emitted to the atmosphere and sedimentation stores 21 (range: 9–65) TgC⋅y−1 in lakes and reservoirs. We show that there is significant regional variation in aquatic carbon flux, but verify that emission across stream and river surfaces represents the dominant flux at 69 (range: 36–110) TgC⋅y−1 or 65% of the total aquatic carbon flux for the conterminous United States. Comparing our results with the output of a suite of terrestrial biosphere models (TBMs), we suggest that within the current modeling framework, calculations of net ecosystem production (NEP) defined as terrestrial only may be overestimated by as much as 27%. However, the internal production and mineralization of carbon in freshwaters remain to be quantified and would reduce the effect of including aquatic carbon fluxes within calculations of terrestrial NEP. Reconciliation of carbon mass–flux interactions between terrestrial and aquatic carbon sources and sinks will require significant additional research and modeling capacity. PMID:26699473

  10. Carbon classified?

    DEFF Research Database (Denmark)

    Lippert, Ingmar

    2012-01-01

    . Using an actor- network theory (ANT) framework, the aim is to investigate the actors who bring together the elements needed to classify their carbon emission sources and unpack the heterogeneous relations drawn on. Based on an ethnographic study of corporate agents of ecological modernisation over...... a period of 13 months, this paper provides an exploration of three cases of enacting classification. Drawing on ANT, we problematise the silencing of a range of possible modalities of consumption facts and point to the ontological ethics involved in such performances. In a context of global warming...

  11. Evaluation of the tracing effect of carbon nanoparticle and carbon nanoparticle-epirubicin suspension in axillary lymph node dissection for breast cancer treatment

    OpenAIRE

    Du, Junze; Zhang, Yongsong; Ming, Jia; Liu, Jing; Zhong, Ling; Liang, Quankun; Fan, Linjun; Jiang, Jun

    2016-01-01

    Abstracts Background Carbon nanoparticle suspension, using smooth carbon particles at a diameter of 21 nm added with suspending agents, is a stable suspension of carbon pellets of 150 nm in diameter. It is obviously inclined to the lymphatic system. There were some studies reporting that carbon nanoparticles are considered as superior tracers for sentinel lymph nodes because of their stability and operational feasibility. However, there were few study concerns about the potential treatment ef...

  12. Carbon Nanomembranes.

    Science.gov (United States)

    Turchanin, Andrey; Gölzhäuser, Armin

    2016-08-01

    Carbon nanomembranes (CNMs) are synthetic 2D carbon sheets with tailored physical or chemical properties. These depend on the structure, molecular composition, and surroundings on either side. Due to their molecular thickness, they can be regarded as "interfaces without bulk" separating regions of different gaseous, liquid, or solid components and controlling the materials exchange between them. Here, a universal scheme for the fabrication of 1 nm-thick, mechanically stable, functional CNMs is presented. CNMs can be further modified, for example perforated by ion bombardment or chemically functionalized by the binding of other molecules onto the surfaces. The underlying physical and chemical mechanisms are described, and examples are presented for the engineering of complex surface architectures, e.g., nanopatterns of proteins, fluorescent dyes, or polymer brushes. A simple transfer procedure allows CNMs to be placed on various support structures, which makes them available for diverse applications: supports for electron and X-ray microscopy, nanolithography, nanosieves, Janus nanomembranes, polymer carpets, complex layered structures, functionalization of graphene, novel nanoelectronic and nanomechanical devices. To close, the potential of CNMs in filtration and sensorics is discussed. Based on tests for the separation of gas molecules, it is argued that ballistic membranes may play a prominent role in future efforts of materials separation. PMID:27281234

  13. 21 CFR 872.3680 - Polytetrafluoroethylene (PTFE) vitreous carbon materials.

    Science.gov (United States)

    2010-04-01

    ... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3680... the sockets in which teeth are rooted) or intended to coat metal surgical implants to be placed in the alveoli (sockets in which the teeth are rooted) or the temporomandibular joints (the joint between...

  14. 21 CFR 177.1312 - Ethylene-carbon monoxide copolymers.

    Science.gov (United States)

    2010-04-01

    ... D1238-82, condition E “Standard Test Method for Flow Rates of Thermoplastics by Extrusion Plastometer,” which is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may...

  15. High resolution carbon and oxygen K-LL Auger spectra of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Hiltunen, A.; Aksela, S.; Vikor, Gy.; Ricz, S. E-mail: ricz@atomki.hu; Koever, A.; Sulik, B

    1999-06-03

    The proton excited carbon and oxygen K-LL Auger spectra of carbon dioxide were measured using the high-resolution, angular resolving ESA-21 electron spectrometer. The proton impact energy was 1.0 MeV. The transition energies of both K-LL Auger-spectra (oxygen and carbon) are determined and compared with the existing theoretical and earlier experimental data. The experimental line widths full width at half maximum (FWHM) and relative intensities of the Auger lines are determined. The Auger emission was found to be isotropic within the experimental accuracy.

  16. Trading forest carbon

    Science.gov (United States)

    The nature of carbon in forests is discussed from the perspective of carbon trading. Carbon inventories, specifically in the area of land use and forestry are reviewed for the Pacific Northwest. Carbon turnover in forests is discussed as it relates to carbon sequestration. Scient...

  17. 50 CFR 21.21 - Import and export permits.

    Science.gov (United States)

    2010-10-01

    ... additional permits to take a bird from the United States or to return home with it (see 50 CFR part 15 (Wild... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Import and export permits. 21.21 Section... WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD PERMITS Specific Permit Provisions § 21.21 Import and...

  18. 21 CFR 522.542 - Dexamethasone-21-isonicotinate suspension.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Dexamethasone-21-isonicotinate suspension. 522.542... § 522.542 Dexamethasone-21-isonicotinate suspension. (a) Specifications. Each milliliter of sterile suspension contains 1 milligram of dexamethasone-21-isonicotinate. (b) Sponsor. No. 000010 in § 510.600(c)...

  19. Photoconductivity of Activated Carbon Fibers

    Science.gov (United States)

    Kuriyama, K.; Dresselhaus, M. S.

    1990-08-01

    The photoconductivity is measured on a high-surface-area disordered carbon material, namely activated carbon fibers, to investigate their electronic properties. Measurements of decay time, recombination kinetics and temperature dependence of the photoconductivity generally reflect the electronic properties of a material. The material studied in this paper is a highly disordered carbon derived from a phenolic precursor, having a huge specific surface area of 1000--2000m{sup 2}/g. Our preliminary thermopower measurements suggest that this carbon material is a p-type semiconductor with an amorphous-like microstructure. The intrinsic electrical conductivity, on the order of 20S/cm at room temperature, increases with increasing temperature in the range 30--290K. In contrast with the intrinsic conductivity, the photoconductivity in vacuum decreases with increasing temperature. The recombination kinetics changes from a monomolecular process at room temperature to a biomolecular process at low temperatures. The observed decay time of the photoconductivity is {approx equal}0.3sec. The magnitude of the photoconductive signal was reduced by a factor of ten when the sample was exposed to air. The intrinsic carrier density and the activation energy for conduction are estimated to be {approx equal}10{sup 21}/cm{sup 3} and {approx equal}20meV, respectively. The majority of the induced photocarriers and of the intrinsic carriers are trapped, resulting in the long decay time of the photoconductivity and the positive temperature dependence of the conductivity.

  20. Carbon dioxide reducing processes; Koldioxidreducerande processer

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, Fredrik

    1999-12-01

    This thesis discusses different technologies to reduce or eliminate the carbon dioxide emissions, when a fossil fuel is used for energy production. Emission reduction can be accomplished by separating the carbon dioxide for storage or reuse. There are three different ways of doing the separation. The carbon dioxide can be separated before the combustion, the process can be designed so that the carbon dioxide can be separated without any energy consumption and costly systems or the carbon dioxide can be separated from the flue gas stream. Two different concepts of separating the carbon dioxide from a combined cycle are compared, from the performance and the economical point of view, with a standard natural gas fired combined cycle where no attempts are made to reduce the carbon dioxide emissions. One concept is to use absorption technologies to separate the carbon dioxide from the flue gas stream. The other concept is based on a semi-closed gas turbine cycle using carbon dioxide as working fluid and combustion with pure oxygen, generated in an air-separating unit. The calculations show that the efficiency (power) drop is smaller for the first concept than for the second, 8.7 % points compared to 13.7 % points, when power is produced. When both heat and power are produced, the relation concerning the efficiency (power) remains. Regarding the overall efficiency (heat and power) the opposite relation is present. A possible carbon dioxide tax must exceed 0.21 SEK/kg CO{sub 2} for it to be profitable to separate carbon dioxide with any of these technologies.

  1. Carbon Farming as a Carbon Negative Technology

    Science.gov (United States)

    Anderson, C.; Laird, D.; Hayes, D. J.

    2015-12-01

    Carbon farms have a pivotal role in national and international efforts to mitigate and adapt to climate change. A carbon farm in its broadest sense is one that reduces greenhouse gas (GHG) emissions or captures and holds carbon in vegetation and soils. Their capacity to remove carbon from the air and store it safely and permanently, while providing additional human and ecosystem benefits, means they could contribute significantly to national efforts to stabilize or reduce GHGs. We examine carbon farms in the context of corn and soybean production agriculture. We illustrate, using Iowa data but with relevance across United States corn and soybean production, the potential for carbon farms to reduce human GHG emissions and sequester carbon permanently at a rate that has meaningful impact on global greenhouse gas concentration. Carbon has been viewed as a next generation cash crop in Iowa for over a decade. The carbon farm perspective, however, goes beyond carbon as cash crop to make carbon the center of an entire farm enterprise. The transformation is possible through slight adjustment crop practices mixed with advances in technology to sequester carbon through biochar. We examine carbon balance of Iowa agriculture given only the combination of slight reduction in fertilizer and sequestration by biochar. We find the following. Iowa carbon farms could turn Iowa agriculture into a carbon sink. The estimated range of GHG reduction by statewide implementation of carbon farms is 19.46 to 90.27 MMt CO2-equivalent (CO2-e), while the current agricultural CO2-e emission estimate is 35.38 MMt CO2-e. Iowa carbon farm GHG reduction would exceed Iowa GHG reduction by wind energy (8.7 MMt CO2-e) and could exceed combined reductions from wind energy and corn grain ethanol (10.7 MMt CO2-e; 19.4 MMt CO2-e combined). In fact, Iowa carbon farms alone could exceed GHG reduction from national corn grain ethanol production (39.6 MMt CO2-e). A carbon price accessible to agricultural

  2. Net Ecosystem Carbon Flux

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Net Ecosystem Carbon Flux is defined as the year-over-year change in Total Ecosystem Carbon Stock, or the net rate of carbon exchange between an ecosystem and the...

  3. Carbon Monoxide (CO)

    Science.gov (United States)

    ... IAQ) » Carbon Monoxide's Impact on Indoor Air Quality Carbon Monoxide's Impact on Indoor Air Quality On this ... length of exposure. Top of Page Sources of Carbon Monoxide Sources of CO include: unvented kerosene and ...

  4. Carbon Monoxide Poisoning

    Science.gov (United States)

    ... Recommend on Facebook Tweet Share Compartir What is Carbon Monoxide? Carbon monoxide, or “CO,” is an odorless, colorless gas that can kill you. Carbon monoxide detector Where is CO found? CO is ...

  5. Asian Highlands Perspectives 21

    Directory of Open Access Journals (Sweden)

    various

    2012-12-01

    Full Text Available AHP21 is the fourth volume of collected essays published by AHP. This volume features articles on English language education and globalization; New Year celebrations in A mdo; hail prevention rituals and practitioners; pyramid schemes on the Tibetan Plateau; Tibetans and Muslims in northwest China; sacred dairies, dairymen, and buffaloes of the Nilgiri Mountains in South India; an A mdo family's annual income and expenses; vernacular architecture; and cultural change in the context of a female rite of passage in A mdo. Volume 21 also contains six short stories and ten reviews.

  6. Integral Ring Carbon-Carbon Piston

    Science.gov (United States)

    Northam, G. Burton (Inventor)

    1999-01-01

    An improved structure for a reciprocating internal combustion engine or compressor piston fabricate from carbon-carbon composite materials is disclosed. An integral ring carbon-carbon composite piston, disclosed herein, reduces the need for piston rings and for small clearances by providing a small flexible, integral component around the piston that allows for variation in clearance due to manufacturing tolerances, distortion due to pressure and thermal loads, and variations in thermal expansion differences between the piston and cylinder liner.

  7. Carbon dioxide sequestration by mineral carbonation

    OpenAIRE

    Huijgen, W.J.J.

    2007-01-01

    The increasing atmospheric carbon dioxide (CO2) concentration, mainly caused by fossil fuel combustion, has lead to concerns about global warming. A possible technology that can contribute to the reduction of carbon dioxide emissions is CO2 sequestration by mineral carbonation. The basic concept behind mineral CO2 sequestration is the mimicking of natural weathering processes in which calcium or magnesium containing minerals react with gaseous CO2 and form solid calcium or magnesium carbonate...

  8. Carbon Residence Times in Pedogenic Carbonate Pools

    Science.gov (United States)

    Monger, H.; Feng, Y.; Karnjanapiboonwang, A.

    2013-12-01

    Soil carbonate is a huge pool of terrestrial carbon that contains at least 930 to 940 Pg C and has influx rates on the order of 1 to 12 g CaCO3/m2/yr. Such large mass to flux ratios yield long mean residence times for carbon (e.g., 85,000 years)--assuming steady state. Like other global carbon pools, the soil carbonate pool has smaller sub-pools with higher influx rates and shorter mean residence times. For example, pedogenic carbonate in coppice dunes known to have formed since 1858 and carbonate formed on lithic artifacts in soils at archaeology sites suggests mean residence times can be as short as 120 years--again assuming steady state. Harder to assess are efflux rates as CO2 emissions or bicarbonate leaching. Some Bowen-ratio studies have nevertheless found evidence for CO2 emissions resulting from carbonate dissolution, and other studies have found evidence for bicarbonate leaching based on dissolution pipes through calcic horizons using soil morphology studies. Since an understanding of mean residence times are prerequisite for a better understanding of soil carbonate in the global carbon cycle, especially in a scenario of an expanding Aridosphere, more influx and efflux measurements are needed to evaluate the possibility of carbon sequestration by soil carbonate in hyperarid, arid, semiarid, or subhumid soils.

  9. Carbon dioxide sequestration by mineral carbonation

    NARCIS (Netherlands)

    Huijgen, W.J.J.

    2007-01-01

    The increasing atmospheric carbon dioxide (CO2) concentration, mainly caused by fossil fuel combustion, has lead to concerns about global warming. A possible technology that can contribute to the reduction of carbon dioxide emissions is CO2 sequestration by mineral carbonation. The basic concept beh

  10. Powernext, newsletter no.21

    International Nuclear Information System (INIS)

    This newsletter provides information and statistical data on the four business unit of Powernext: Powernext Day-Ahead, Powernext Carbon, Powernext Futures and Powernext Weather. Powernext Day-Ahead provides a short term price reference to manage the volume risk. Powernext Day-Ahead counts close to 50 members among producers, suppliers, eligible consumers, etc. Powernext Carbon is a spot market of CO2 allowances. The market model is the result of a three-fold partnership between Powernext, Caisse des Depots and Euronext. Powernext Carbon counts close to 30 active members. More than 2 Million tonnes of CO2 have been traded since the launch of the market on 24 June. Powernext Carbon has made a name for itself as the most liquid CO2 allowances spot market in Europe to date. Powernext Futures has made a name for itself as a price reference for the medium term market. Its market makers and members guarantee a high-quality market over a time period going up until 2008. Powernext Weather is a range of economically weather driven temperature indices provided by our partner Meteo France. These indices are decision making or hedging tools. This analysis concerns July 2004. (A.L.B.)

  11. Chapter 21. chlorine dioxide

    Science.gov (United States)

    Submerging terminal leafy cuttings of Rhododendron L. 'Gumpo White' ('Gumpo White' azalea) in 50 °C water for 21 min was previously shown to eliminate binucleate Rhizoctonia species, the cause of azalea web blight, from plant tissues. Prior to considering commercial use of this practice, a better un...

  12. Vilnakommandoet 1920-21

    DEFF Research Database (Denmark)

    Clemmesen, Michael Hesselholt

    Danmarks første kontingent til en international fredsbevarende styrke, Vilnakommandoet i 1920-21, kom aldrig af sted, men denne analyse af dens internationale og nationale forudsætninger er interessant som et bidrag både til dansk udenrigspolitik under Venstre-regeringen 1920-24, til det tidlige...

  13. Main: TATCCACHVAL21 [PLACE

    Lifescience Database Archive (English)

    Full Text Available TATCCACHVAL21 S000416 10-May-2006 (last modified) kehi TATCCAC box is a part of the... (see S000181), or GA-responsive element (GARE); the pyrimidine box, CCTTTT (see S000259); and the TATCCAC b...ox, which are necessary for a full GA response; gibberellin; GA; GARC; barley (Hordeum vulgare) TATCCAC ...

  14. Africa and the global carbon cycle

    Directory of Open Access Journals (Sweden)

    Denning A Scott

    2007-03-01

    Full Text Available Abstract The African continent has a large and growing role in the global carbon cycle, with potentially important climate change implications. However, the sparse observation network in and around the African continent means that Africa is one of the weakest links in our understanding of the global carbon cycle. Here, we combine data from regional and global inventories as well as forward and inverse model analyses to appraise what is known about Africa's continental-scale carbon dynamics. With low fossil emissions and productivity that largely compensates respiration, land conversion is Africa's primary net carbon release, much of it through burning of forests. Savanna fire emissions, though large, represent a short-term source that is offset by ensuing regrowth. While current data suggest a near zero decadal-scale carbon balance, interannual climate fluctuations (especially drought induce sizeable variability in net ecosystem productivity and savanna fire emissions such that Africa is a major source of interannual variability in global atmospheric CO2. Considering the continent's sizeable carbon stocks, their seemingly high vulnerability to anticipated climate and land use change, as well as growing populations and industrialization, Africa's carbon emissions and their interannual variability are likely to undergo substantial increases through the 21st century.

  15. Synthesis of 21-Thioureido or 21-Ureidocorticosteroids as NOS Inhibitors

    Institute of Scientific and Technical Information of China (English)

    PENG Jiu-He; HAN Chong; LI Bing-Jie; CHENG Jin-Pei

    2003-01-01

    @@ Aryl or alkyl thioureas are known as NOS inhibitors, [1~ 4] in this paper we reported the synthesis of 21-thioureido or 21-ureidocorticosteroids as potential NOS inhibitors. The title compounds were prepared from primary 21aminocorticosteroids and in vivo generated aryl isothiocynates. For comparison, 21-ureidocorticoids were synthesized in a similar way. Scheme 1 shows the preparation of 21-thioureido and 21-ureidoprednisolone. Other corticosteroids' 2 1-thioureido or ureido derivatives, such as hydrocortisone' s, methylprednisolne' s, dexamethasone' s, betamethasone' s, RS' s, cortisone' s and prednisone' s, were also prepared. Preliminary pharmacology evaluation showed that they possessed NOS inhibiting activities.

  16. Molecular and stable carbon isotopic compositions of hopanoids in seep carbonates from the South China Sea continental slope

    Science.gov (United States)

    Guan, Hongxiang; Sun, Yongge; Mao, Shengyi; Zhu, Xiaowei; Wu, Nengyou

    2014-10-01

    The lipid biomarkers of hopanoids in cold seep carbonates from the South China Sea continental slope were investigated by gas chromatography-mass spectrometer (GC-MS) and gas chromatography-isotope ratio-mass spectrometer (GC-ir-MS). The distribution of hopanes/hopenes shows a preference for the ‘biological’ 17β(H), 21β(H)-over the ‘geological’ 17α(H), 21β(H)-configuration. This interpretation is in agreement with the strong odd-even preference of long-chain n-alkanes in those samples, suggesting that the ββ hopanes may be the early diagenetic products of biohopanoids and the αβ, βα configurations of hopanes were mainly derived from allochthonous sources contributing to the organic matter of the carbonates. In terms of hopanoid acids, the C30 to C33 17β(H), 21β(H)-hopanoid acids were detected with C32 17β(H), 21β(H)-hopanoid acid being the most abundant. However, there is a significant difference in stable carbon isotopic compostions of the C32 17β(H), 21β(H)-hopanoic acid among samples (-30.7‰ to -69.8‰). The δ13C values match well with the carbon isotopic compositions of SRB-derived iso-/anteiso-C15:0 fatty acids in the samples, which strongly depend on the carbon utilization types by microbe. The most abundant compound of hopanols detected in the samples, C30-17β(H), 21β(H)-hopanol, may be a good indicator of diagenetic product of type I methanotrophs. The molecular and carbon isotopic compositions of hopanoids demonstrate clearly that there is a combination contribution of both SRB and type I or type X methanotrophs to the source organism in the seep carbonates from the South China Sea continental slope.

  17. From carbon nanotubes to carbon atomic chains

    Science.gov (United States)

    Casillas García, Gilberto; Zhang, Weijia; José-Yacamán, Miguel

    2010-10-01

    Carbyne is a linear allotrope of carbon. It is formed by a linear arrangement of carbon atoms with sp-hybridization. We present a reliable and reproducible experiment to obtain these carbon atomic chains using few-layer-graphene (FLG) sheets and a HRTEM. First the FLG sheets were synthesized from worm-like exfoliated graphite and then drop-casted on a lacey-carbon copper grid. Once in the TEM, two holes are opened near each other in a FLG sheet by focusing the electron beam into a small spot. Due to the radiation, the carbon atoms rearrange themselves between the two holes and form carbon fibers. The beam is concentrated on the carbon fibers in order excite the atoms and induce a tension until multi wall carbon nanotube (MWCNT) is formed. As the radiation continues the MWCNT breaks down until there is only a single wall carbon nanotube (SWCNT). Then, when the SWCNT breaks, an atomic carbon chain is formed, lasts for several seconds under the radiation and finally breaks. This demonstrates the stability of this carbon structure.

  18. Coulomb drag in multiwall armchair carbon nanotubes

    DEFF Research Database (Denmark)

    Lunde, A.M.; Jauho, Antti-Pekka

    2004-01-01

    We calculate the transresistivity rho(21) between two concentric armchair nanotubes in a diffusive multiwall carbon nanotube as a function of temperature T and Fermi level epsilon(F). We approximate the tight-binding band structure by two crossing bands with a linear dispersion near the Fermi...... surface. The cylindrical geometry of the nanotubes and the different parities of the Bloch states are accounted for in the evaluation of the effective Coulomb interaction between charges in the concentric nanotubes. We find a broad peak in rho(21) as a function of temperature at roughly T similar to 0.4T...

  19. Neutral atomic carbon in dense molecular clouds

    Science.gov (United States)

    Zmuidzinas, J.; Betz, A. L.; Boreiko, R. T.; Goldhaber, D. M.

    1988-01-01

    The 370 micron 3P2-3P1 fine-structure line of neutral carbon was detected in seven sources: OMC 1, NGC 2024, S140, W3, DR 21, M17, and W51. Simultaneous analysis of J = 2-1 data and available observations of the J = 1-0 line make it possible to deduce optical depths and excitation temperatures for these lines. These data indicate that both C I lines are likely to be optically thin, and that the ratio of C I to CO column densities in these clouds is typically about 0.1.

  20. Carbon nanotube composite materials

    Energy Technology Data Exchange (ETDEWEB)

    O' Bryan, Gregory; Skinner, Jack L; Vance, Andrew; Yang, Elaine Lai; Zifer, Thomas

    2015-03-24

    A material consisting essentially of a vinyl thermoplastic polymer, un-functionalized carbon nanotubes and hydroxylated carbon nanotubes dissolved in a solvent. Un-functionalized carbon nanotube concentrations up to 30 wt % and hydroxylated carbon nanotube concentrations up to 40 wt % can be used with even small concentrations of each (less than 2 wt %) useful in producing enhanced conductivity properties of formed thin films.

  1. Mutagenicity of carbon nanomaterials

    DEFF Research Database (Denmark)

    Wallin, Håkan; Jacobsen, Nicklas Raun; White, Paul A;

    2011-01-01

    Carbon nanomaterials such carbon nanotubes, graphene and fullerenes are some the most promising nanomaterials. Although carbon nanomaterials have been reported to possess genotoxic potential, it is imperitive to analyse the data on the genotoxicity of carbon nanomaterials in vivo and in vitro...

  2. Electroanalysis with carbon paste electrodes

    CERN Document Server

    Svancara, Ivan; Walcarius, Alain; Vytras, Karel

    2011-01-01

    Introduction to Electrochemistry and Electroanalysis with Carbon Paste-Based ElectrodesHistorical Survey and GlossaryField in Publication Activities and LiteratureCarbon Pastes and Carbon Paste ElectrodesCarbon Paste as the Binary MixtureClassification of Carbon Pastes and Carbon Paste ElectrodesConstruction of Carbon Paste HoldersCarbon Paste as the Electrode MaterialPhysicochemical Properties of Carbon PastesElectrochemical Characteristics of Carbon PastesTesting of Unmodified CPEsIntera

  3. Mesoporous carbon materials

    Science.gov (United States)

    Dai, Sheng; Fulvio, Pasquale Fernando; Mayes, Richard T.; Wang, Xiqing; Sun, Xiao-Guang; Guo, Bingkun

    2014-09-09

    A conductive mesoporous carbon composite comprising conductive carbon nanoparticles contained within a mesoporous carbon matrix, wherein the conductive mesoporous carbon composite possesses at least a portion of mesopores having a pore size of at least 10 nm and up to 50 nm, and wherein the mesopores are either within the mesoporous carbon matrix, or are spacings delineated by surfaces of said conductive carbon nanoparticles when said conductive carbon nanoparticles are fused with each other, or both. Methods for producing the above-described composite, devices incorporating them (e.g., lithium batteries), and methods of using them, are also described.

  4. Pyrolyzed thin film carbon

    Science.gov (United States)

    Tai, Yu-Chong (Inventor); Liger, Matthieu (Inventor); Harder, Theodore (Inventor); Konishi, Satoshi (Inventor); Miserendino, Scott (Inventor)

    2010-01-01

    A method of making carbon thin films comprises depositing a catalyst on a substrate, depositing a hydrocarbon in contact with the catalyst and pyrolyzing the hydrocarbon. A method of controlling a carbon thin film density comprises etching a cavity into a substrate, depositing a hydrocarbon into the cavity, and pyrolyzing the hydrocarbon while in the cavity to form a carbon thin film. Controlling a carbon thin film density is achieved by changing the volume of the cavity. Methods of making carbon containing patterned structures are also provided. Carbon thin films and carbon containing patterned structures can be used in NEMS, MEMS, liquid chromatography, and sensor devices.

  5. Marginalia no. 21

    OpenAIRE

    Library, Merrill-Cazier

    2006-01-01

    Issue Number 21: Autumn 2006 “AS THE LIBRARY SHAPES STUDENTS, STUDENTS SHAPE THE LIBRARY”-A message from Director, Linda Wolcott LET US EAT CAKE! MERRILL-CAZIER LIBRARY IS 1-YEAR OLD!-The Library holds a birthday party. IDEAS IN FLIGHT-Patrick Williams on a popular birdhouse exhibit by Darrin Brooks Interior Design students. BOOKS STUDIO EXHIBIT: BASIC BINDING & BEYOND-Dennise Gackstetter describes unique book as art exhibit MORE GALLERY SPACE: FOR STUDENT EXHIBITS- A LOT MORE ...

  6. 21 CFR 1.21 - Failure to reveal material facts.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Failure to reveal material facts. 1.21 Section 1... GENERAL ENFORCEMENT REGULATIONS General Labeling Requirements § 1.21 Failure to reveal material facts. (a) Labeling of a food, drug, device, or cosmetic shall be deemed to be misleading if it fails to reveal...

  7. 21 CFR 21.44 - Verification of identity.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Verification of identity. 21.44 Section 21.44 Food... Verification of identity. (a) An individual seeking access to records in a Privacy Act Record System may be... identity. The identification required shall be suitable considering the nature of the records sought....

  8. 21 CFR 1303.21 - Individual manufacturing quotas.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Individual manufacturing quotas. 1303.21 Section... Manufacturing Quotas § 1303.21 Individual manufacturing quotas. (a) The Administrator shall, on or before July 1... controlled substance listed in Schedule I or II, and who applies for a manufacturing quota, an...

  9. 21 CFR 1315.21 - Individual manufacturing quotas.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Individual manufacturing quotas. 1315.21 Section... PRODUCTION QUOTAS FOR EPHEDRINE, PSEUDOEPHEDRINE, AND PHENYLPROPANOLAMINE Individual Manufacturing Quotas § 1315.21 Individual manufacturing quotas. The Administrator shall, on or before July 1 of each year,...

  10. DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Harold H. Schobert; M. Mercedes Maroto-Valer; Zhe Lu

    2003-09-30

    The increasing role of coal as a source of energy in the 21st century will demand environmental and cost-effective strategies for the use of coal combustion by-products (CCBPs), mainly unburned carbon in fly ash. Unburned carbon is nowadays regarded as a waste product and its fate is mainly disposal, due to the present lack of efficient routes for its utilization. However, unburned carbon is a potential precursor for the production of adsorbent carbons, since it has gone through a devolatilization process while in the combustor, and therefore, only requires to be activated. Accordingly, the principal objective of this work was to characterize and utilize the unburned carbon in fly ash for the production of activated carbons. The unburned carbon samples were collected from different combustion systems, including pulverized utility boilers, a utility cyclone, a stoker, and a fluidized bed combustor. LOI (loss-on-ignition), proximate, ultimate, and petrographic analyses were conducted, and the surface areas of the samples were characterized by N2 adsorption isotherms at 77K. The LOIs of the unburned carbon samples varied between 21.79-84.52%. The proximate analyses showed that all the samples had very low moisture contents (0.17 to 3.39 wt %), while the volatile matter contents varied between 0.45 to 24.82 wt%. The elemental analyses show that all the unburned carbon samples consist mainly of carbon with very little hydrogen, nitrogen, sulfur and oxygen In addition, the potential use of unburned carbon as precursor for activated carbon (AC) was investigated. Activated carbons with specific surface area up to 1075m{sup 2}/g were produced from the unburned carbon. The porosity of the resultant activated carbons was related to the properties of the unburned carbon feedstock and the activation conditions used. It was found that not all the unburned carbon samples are equally suited for activation, and furthermore, their potential as activated carbons precursors could be

  11. Identifying 21st Century Capabilities

    Science.gov (United States)

    Stevens, Robert

    2012-01-01

    What are the capabilities necessary to meet 21st century challenges? Much of the literature on 21st century skills focuses on skills necessary to meet those challenges associated with future work in a globalised world. The result is a limited characterisation of those capabilities necessary to address 21st century social, health and particularly…

  12. 21st Century Skills Map

    Science.gov (United States)

    Partnership for 21st Century Skills, 2011

    2011-01-01

    The Partnership for 21st Century Skills (P21) has forged alliances with key national organizations representing the core academic subjects, including Social Studies, English, Math, Science, Geography, World Languages and the Arts. These collaborations have resulted in the development of 21st Century Skills Maps that illustrate the essential…

  13. Adsorption of Carbon Dioxide on Activated Carbon

    Institute of Scientific and Technical Information of China (English)

    Bo Guo; Liping Chang; Kechang Xie

    2006-01-01

    The adsorption of CO2 on a raw activated carbon A and three modified activated carbon samples B, C, and D at temperatures ranging from 303 to 333 K and the thermodynamics of adsorption have been investigated using a vacuum adsorption apparatus in order to obtain more information about the effect of CO2 on removal of organic sulfur-containing compounds in industrial gases. The active ingredients impregnated in the carbon samples show significant influence on the adsorption for CO2 and its volumes adsorbed on modified carbon samples B, C, and D are all larger than that on the raw carbon sample A. On the other hand, the physical parameters such as surface area, pore volume, and micropore volume of carbon samples show no influence on the adsorbed amount of CO2. The Dubinin-Radushkevich (D-R) equation was the best model for fitting the adsorption data on carbon samples A and B, while the Freundlich equation was the best fit for the adsorption on carbon samples C and D. The isosteric heats of adsorption on carbon samples A, B, C, and D derived from the adsorption isotherms using the Clapeyron equation decreased slightly increasing surface loading. The heat of adsorption lay between 10.5 and 28.4 kJ/mol, with the carbon sample D having the highest value at all surface coverages that were studied. The observed entropy change associated with the adsorption for the carbon samples A, B, and C (above the surface coverage of 7 ml/g) was lower than the theoretical value for mobile adsorption. However, it was higher than the theoretical value for mobile adsorption but lower than the theoretical value for localized adsorption for carbon sample D.

  14. Accelerating Mineral Carbonation Using Carbonic Anhydrase.

    Science.gov (United States)

    Power, Ian M; Harrison, Anna L; Dipple, Gregory M

    2016-03-01

    Carbonic anhydrase (CA) enzymes have gained considerable attention for their potential use in carbon dioxide (CO2) capture technologies because they are able to catalyze rapidly the interconversion of aqueous CO2 and bicarbonate. However, there are challenges for widespread implementation including the need to develop mineralization process routes for permanent carbon storage. Mineral carbonation of highly reactive feedstocks may be limited by the supply rate of CO2. This rate limitation can be directly addressed by incorporating enzyme-catalyzed CO2 hydration. This study examined the effects of bovine carbonic anhydrase (BCA) and CO2-rich gas streams on the carbonation rate of brucite [Mg(OH)2], a highly reactive mineral. Alkaline brucite slurries were amended with BCA and supplied with 10% CO2 gas while aqueous chemistry and solids were monitored throughout the experiments (hours to days). In comparison to controls, brucite carbonation using BCA was accelerated by up to 240%. Nesquehonite [MgCO3·3H2O] precipitation limited the accumulation of hydrated CO2 species, apparently preventing BCA from catalyzing the dehydration reaction. Geochemical models reproduce observed reaction progress in all experiments, revealing a linear correlation between CO2 uptake and carbonation rate. Data demonstrates that carbonation in BCA-amended reactors remained limited by CO2 supply, implying further acceleration is possible. PMID:26829491

  15. Carbon fuel cells with carbon corrosion suppression

    Science.gov (United States)

    Cooper, John F.

    2012-04-10

    An electrochemical cell apparatus that can operate as either a fuel cell or a battery includes a cathode compartment, an anode compartment operatively connected to the cathode compartment, and a carbon fuel cell section connected to the anode compartment and the cathode compartment. An effusion plate is operatively positioned adjacent the anode compartment or the cathode compartment. The effusion plate allows passage of carbon dioxide. Carbon dioxide exhaust channels are operatively positioned in the electrochemical cell to direct the carbon dioxide from the electrochemical cell.

  16. The Uncertain Carbon Emissions in China (Invited)

    Science.gov (United States)

    Liu, Z.; Guan, D.

    2013-12-01

    Anthropogenic fossil fuel emissions are considered as being well understood with a low uncertainty (9.1 × 0.5Gt C yr-1). By using full transparency emission inventory which the energy consumption, fuel heating values, carbon content and oxidation rate reported separately in sectoal level, here we found new 2.1 Gt C yr-1 (23% of global total) uncertainties of carbon emission inventory, which mainly contributed by the mass energy use and consumption coal quality in China and by misunderstanding of fuel quality in international fossil fuel trade. Increment of coal's carbon emission in China and India are equivalent to 130 % of global total coal's emission growth during 2008-2010, by using macro energy statistics and bottom up coal mine datasets, the difference carbon emission estimates from China and India can up to 1.32 C yr-1. Emissions from international trade of coal could produce another 0.08 Gt C yr-1 uncertainty. These new emerging 1.4 Gt C yr-1 uncertainties implies a significant mis-estimation of human induced carbon emissions and a new dominating factor in contributing the global carbon budget residual.

  17. Soil Carbon Sequestration in India

    International Nuclear Information System (INIS)

    With a large land area and diverse ecoregions, there is a considerable potential of terrestrial/soil carbon sequestration in India. Of the total land area of 329 million hectares (Mha), 297 Mha is the land area comprising 162 Mha of arable land, 69 Mha of forest and woodland, 11 Mha of permanent pasture, 8 Mha of permanent crops and 58 Mha is other land uses. The soil organic carbon (SOC) pool is estimated at 21 Pg (petagram = Pg = 1 x 1015 g billion ton) to 30-cm depth and 63 Pg to 150-cm depth. The soil inorganic carbon (SIC) pool is estimated at 196 Pg to 1-m depth. The SOC concentration in most cultivated soils is less than 5 g/kg compared with 15 to 20 g/kg in uncultivated soils. Low SOC concentration is attributed to plowing, removal of crop residue and other biosolids, and mining of soil fertility. Accelerated soil erosion by water leads to emission of 6 Tg C/y. Important strategies of soil C sequestration include restoration of degraded soils, and adoption of recommended management practices (RMPs) of agricultural and forestry soils. Potential of soil C sequestration in India is estimated at 7 to 10 Tg C/y for restoration of degraded soils and ecosystems, 5 to 7 Tg C/y for erosion control, 6 to 7 Tg C/y for adoption of RMPs on agricultural soils, and 22 to 26 Tg C/y for secondary carbonates. Thus, total potential of soil C sequestration is 39 to 49 (44± 5) Tg C/y

  18. Carbon sequestration via wood burial

    Directory of Open Access Journals (Sweden)

    Zeng Ning

    2008-01-01

    Full Text Available Abstract To mitigate global climate change, a portfolio of strategies will be needed to keep the atmospheric CO2 concentration below a dangerous level. Here a carbon sequestration strategy is proposed in which certain dead or live trees are harvested via collection or selective cutting, then buried in trenches or stowed away in above-ground shelters. The largely anaerobic condition under a sufficiently thick layer of soil will prevent the decomposition of the buried wood. Because a large flux of CO2 is constantly being assimilated into the world's forests via photosynthesis, cutting off its return pathway to the atmosphere forms an effective carbon sink. It is estimated that a sustainable long-term carbon sequestration potential for wood burial is 10 ± 5 GtC y-1, and currently about 65 GtC is on the world's forest floors in the form of coarse woody debris suitable for burial. The potential is largest in tropical forests (4.2 GtC y-1, followed by temperate (3.7 GtC y-1 and boreal forests (2.1 GtC y-1. Burying wood has other benefits including minimizing CO2 source from deforestation, extending the lifetime of reforestation carbon sink, and reducing fire danger. There are possible environmental impacts such as nutrient lock-up which nevertheless appears manageable, but other concerns and factors will likely set a limit so that only part of the full potential can be realized. Based on data from North American logging industry, the cost for wood burial is estimated to be $14/tCO2($50/tC, lower than the typical cost for power plant CO2 capture with geological storage. The cost for carbon sequestration with wood burial is low because CO2 is removed from the atmosphere by the natural process of photosynthesis at little cost. The technique is low tech, distributed, easy to monitor, safe, and reversible, thus an attractive option for large-scale implementation in a world-wide carbon market.

  19. Dissolved inorganic carbon, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Coulometer for DIC measurement and other instruments from the POLARSTERN in the South Atlantic Ocean from 1992-05-21 to 1992-08-05 (NODC Accession 0116641)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0116641 includes chemical, discrete sample, physical and profile data collected from POLARSTERN in the South Atlantic Ocean from 1992-05-21 to...

  20. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Coulometer for DIC measurement and other instruments from the SEIFU MARU in the Sea of Japan from 2008-10-21 to 2008-11-25 (NODC Accession 0112358)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112358 includes biological, chemical, discrete sample, physical and profile data collected from SEIFU MARU in the Sea of Japan from 2008-10-21 to...

  1. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Coulometer for DIC measurement and other instruments from the MIRAI in the North Pacific Ocean from 2003-05-21 to 2003-06-06 (NODC Accession 0112260)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112260 includes chemical, discrete sample, physical and profile data collected from MIRAI in the North Pacific Ocean from 2003-05-21 to 2003-06-06...

  2. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Coulometer for DIC measurement and other instruments from the SHUMPU MARU in the Philippine Sea from 1999-01-21 to 1999-01-28 (NODC Accession 0112306)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112306 includes biological, chemical, discrete sample, physical and profile data collected from SHUMPU MARU in the Philippine Sea from 1999-01-21 to...

  3. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Coulometer for DIC measurement and other instruments from the SHUMPU MARU in the Philippine Sea from 2000-01-21 to 2000-01-28 (NODC Accession 0112311)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112311 includes biological, chemical, discrete sample, physical and profile data collected from SHUMPU MARU in the Philippine Sea from 2000-01-21 to...

  4. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from RRS JAMES COOK in the South Atlantic Ocean from 2009-03-07 to 2009-04-21 (NODC Accession 0108214)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0108214 includes discrete sample and profile data collected from RRS JAMES COOK in the South Atlantic Ocean from 2009-03-07 to 2009-04-21 and...

  5. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the HAKON MOSBY in the North Greenland Sea from 1996-11-21 to 1996-11-30 (NODC Accession 0113544)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113544 includes chemical, discrete sample, physical and profile data collected from HAKON MOSBY in the North Greenland Sea from 1996-11-21 to...

  6. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from MELVILLE in the South Pacific Ocean and Tasman Sea from 2009-11-21 to 2010-02-11 (NODC Accession 0109920)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0109920 includes discrete sample and profile data collected from MELVILLE in the South Pacific Ocean and Tasman Sea from 2009-11-21 to 2010-02-11 and...

  7. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the HEALY in the Baffin Bay and Lincoln Sea from 2003-07-21 to 2003-08-16 (NODC Accession 0113909)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113909 includes chemical, discrete sample, physical and profile data collected from HEALY in the Baffin Bay and Lincoln Sea from 2003-07-21 to...

  8. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the MARION DUFRESNE in the Indian Ocean from 1998-01-21 to 1998-02-19 (NODC Accession 0113570)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113570 includes biological, chemical, discrete sample, physical and profile data collected from MARION DUFRESNE in the Indian Ocean from 1998-01-21...

  9. SALINITY, Total nitrogen, WATER TEMPERATURE, PARTICULATE ORGANIC CARBON and other profile and discrete sample data collected in the North Pacific Ocean on the ATLANTIS, NEW HORIZON and WECOMA cruises AT7-21, NH0307A and others as part of the NEP project from 1997-09-19 to 2004-09-02 (NODC Accession 0115198)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115198 includes profile, discrete sample, physical and chemical data collected aboard the ATLANTIS, NEW HORIZON and WECOMA during cruises AT7-21,...

  10. Evaluation of microbial fuel cell operation using algae as an oxygen supplier: carbon paper cathode vs. carbon brush cathode.

    Science.gov (United States)

    Kakarla, Ramesh; Min, Booki

    2014-12-01

    Microbial fuel cell (MFC) and its cathode performances were compared with use of carbon fiber brush and plain carbon paper cathode electrodes in algae aeration. The MFC having carbon fiber brush cathode exhibited a voltage of 0.21 ± 0.01 V (1,000 Ω) with a cathode potential of around -0.14 ± 0.01 V in algal aeration, whereas MFC with plain carbon paper cathode resulted in a voltage of 0.06 ± 0.005 V with a cathode potential of -0.39 ± 0.01 V. During polarizations, MFC equipped with carbon fiber brush cathode showed a maximum power density of 30 mW/m(2), whereas the MFC equipped with plain carbon paper showed a power density of 4.6 mW/m(2). In algae aeration, the internal resistance with carbon fiber brush cathode was 804 Ω and with plain carbon paper it was 1,210 Ω. The peak currents of MFC operation with carbon fiber brush and plain carbon paper cathodes were -31 mA and -850 µA, respectively. PMID:24890136

  11. Trading forest carbon - OSU

    Science.gov (United States)

    Issues associate with trading carbon sequestered in forests are discussed. Scientific uncertainties associated with carbon measurement are discussed with respect to proposed accounting procedures. Major issues include: (1) Establishing baselines. (2) Determining additivity from f...

  12. Soil Organic Carbon Stock

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Soil organic carbon (SOC) is the carbon held within soil organic constituents (i.e., products produced as dead plants and animals decompose and the soil microbial...

  13. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Education / Safety Education Centers En Español Carbon Monoxide Information Center The Invisible Killer Carbon monoxide, also known ... Install one and check its batteries regularly. View Information About CO Alarms Other CO Topics Safety Tips ...

  14. Biomass Carbon Stock

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Biomass carbon includes carbon stored in above- and below-ground live plant components (such as leaf, branch, stem and root) as well as in standing and down dead...

  15. Carbon Monoxide Safety

    Science.gov (United States)

    ... with the Media Fire Protection Technology Carbon monoxide safety outreach materials Help inform residents in your community ... KB | Spanish PDF 645 KB Handout: carbon monoxide safety Download this handout and add your organization's logo ...

  16. Calcium carbonate overdose

    Science.gov (United States)

    Tums overdose; Calcium overdose ... Calcium carbonate can be dangerous in large amounts. ... Some products that contain calcium carbonate are certain: ... and mineral supplements Other products may also contain calcium ...

  17. Potassium carbonate poisoning

    Science.gov (United States)

    Potassium carbonate is a white powder used to make soap, glass, and other items. This article discusses poisoning from swallowing or breathing in potassium carbonate. This article is for information only. Do ...

  18. Carbon nanotube nanoelectrode arrays

    Science.gov (United States)

    Ren, Zhifeng; Lin, Yuehe; Yantasee, Wassana; Liu, Guodong; Lu, Fang; Tu, Yi

    2008-11-18

    The present invention relates to microelectode arrays (MEAs), and more particularly to carbon nanotube nanoelectrode arrays (CNT-NEAs) for chemical and biological sensing, and methods of use. A nanoelectrode array includes a carbon nanotube material comprising an array of substantially linear carbon nanotubes each having a proximal end and a distal end, the proximal end of the carbon nanotubes are attached to a catalyst substrate material so as to form the array with a pre-determined site density, wherein the carbon nanotubes are aligned with respect to one another within the array; an electrically insulating layer on the surface of the carbon nanotube material, whereby the distal end of the carbon nanotubes extend beyond the electrically insulating layer; a second adhesive electrically insulating layer on the surface of the electrically insulating layer, whereby the distal end of the carbon nanotubes extend beyond the second adhesive electrically insulating layer; and a metal wire attached to the catalyst substrate material.

  19. FGF21 and cardiac physiopathology

    Directory of Open Access Journals (Sweden)

    Anna ePlanavila

    2015-08-01

    Full Text Available The heart is not traditionally considered either a target or a site of fibroblast growth factor-21 (FGF21 production. However, recent findings indicate that FGF21 can act as a cardiomyokine; that is, it is produced by cardiac cells at significant levels and acts in an autocrine manner on the heart itself. The heart is sensitive to the effects of FGF21, both systemic and locally generated, owing to the expression in cardiomyocytes of β-Klotho, the key co-receptor known to confer specific responsiveness to FGF21 action. FGF21 has been demonstrated to protect against cardiac hypertrophy, cardiac inflammation, and oxidative stress. FGF21 expression in the heart is induced in response to cardiac insults, such as experimental cardiac hypertrophy and myocardial infarction in rodents, as well as in failing human hearts. Intracellular mechanisms involving PPARα and Sirt1 mediate transcriptional regulation of the FGF21 gene in response to exogenous stimuli. In humans, circulating FGF21 levels are elevated in coronary heart disease and atherosclerosis, and are associated with a higher risk of cardiovascular events in patients with type 2 diabetes. These findings provide new insights into the role of FGF21 in the heart and may offer potential therapeutic strategies for cardiac disease.

  20. Metal filled porous carbon

    Science.gov (United States)

    Gross, Adam F.; Vajo, John J.; Cumberland, Robert W.; Liu, Ping; Salguero, Tina T.

    2011-03-22

    A porous carbon scaffold with a surface and pores, the porous carbon scaffold containing a primary metal and a secondary metal, where the primary metal is a metal that does not wet the surface of the pores of the carbon scaffold but wets the surface of the secondary metal, and the secondary metal is interspersed between the surface of the pores of the carbon scaffold and the primary metal.

  1. Monthly, global emissions of carbon dioxide from fossil fuel consumption

    DEFF Research Database (Denmark)

    Andres, R.J.; Gregg, Jay Sterling; Losey, L.;

    2011-01-01

    This paper examines available data, develops a strategy and presents a monthly, global time series of fossil-fuel carbon dioxide emissions for the years 1950–2006. This monthly time series was constructed from detailed study of monthly data from the 21 countries that account for approximately 80...... reproduces monthly patterns in the data and the global monthly pattern of emissions is relatively insensitive to the exact proxy assignments used. The data and results presented here should lead to a better understanding of global and regional carbon cycles, especially when the mass data are combined...... with the stable carbon isotope data in atmospheric transport models....

  2. Protolytic carbon film technology

    Energy Technology Data Exchange (ETDEWEB)

    Renschler, C.L.; White, C.A.

    1996-04-01

    This paper presents a technique for the deposition of polyacrylonitrile (PAN) on virtually any surface allowing carbon film formation with only the caveat that the substrate must withstand carbonization temperatures of at least 600 degrees centigrade. The influence of processing conditions upon the structure and properties of the carbonized film is discussed. Electrical conductivity, microstructure, and morphology control are also described.

  3. Carbon nanotube quantum dots

    NARCIS (Netherlands)

    Sapmaz, S.

    2006-01-01

    Low temperature electron transport measurements on individual single wall carbon nanotubes are described in this thesis. Carbon nanotubes are small hollow cylinders made entirely out of carbon atoms. At low temperatures (below ~10 K) finite length nanotubes form quantum dots. Because of its small si

  4. Carbon Goes To…

    Science.gov (United States)

    Savasci, Funda

    2014-01-01

    The purposes of this activity are to help middle school students understand the carbon cycle and realize how human activities affect the carbon cycle. This activity consists of two parts. The first part of the activity focuses on the carbon cycle, especially before the Industrial Revolution, while the second part of the activity focuses on how…

  5. 21 cm Intensity Mapping

    CERN Document Server

    Peterson, Jeffrey B; Ansari, Reza; Bandura, Kevin; Bond, Dick; Bunton, John; Carlson, Kermit; Chang, Tzu-Ching; DeJongh, Fritz; Dobbs, Matt; Dodelson, Scott; Darhmaoui, Hassane; Gnedin, Nick; Halpern, Mark; Hogan, Craig; Goff, Jean-Marc Le; Liu, Tiehui Ted; Legrouri, Ahmed; Loeb, Avi; Loudiyi, Khalid; Magneville, Christophe; Marriner, John; McGinnis, David P; McWilliams, Bruce; Moniez, Marc; Palanque-Delabruille, Nathalie; Pasquinelli, Ralph J; Pen, Ue-Li; Rich, Jim; Scarpine, Vic; Seo, Hee-Jong; Sigurdson, Kris; Seljak, Uros; Stebbins, Albert; Steffen, Jason H; Stoughton, Chris; Timbie, Peter T; Vallinotto, Alberto; Wyithe, Stuart; Yeche, Christophe

    2009-01-01

    Using the 21 cm line, observed all-sky and across the redshift range from 0 to 5, the large scale structure of the Universe can be mapped in three dimensions. This can be accomplished by studying specific intensity with resolution ~ 10 Mpc, rather than via the usual galaxy redshift survey. The data set can be analyzed to determine Baryon Acoustic Oscillation wavelengths, in order to address the question: 'What is the nature of Dark Energy?' In addition, the study of Large Scale Structure across this range addresses the questions: 'How does Gravity effect very large objects?' and 'What is the composition our Universe?' The same data set can be used to search for and catalog time variable and transient radio sources.

  6. Carbon/Carbon Pistons for Internal Combustion Engines

    Science.gov (United States)

    Taylor, A. H.

    1986-01-01

    Carbon/carbon piston performs same function as aluminum pistons in reciprocating internal combustion engines while reducing weight and increasing mechanical and thermal efficiencies of engine. Carbon/carbon piston concept features low piston-to-cylinder wall clearance - so low piston rings and skirts unnecessary. Advantages possible by negligible coefficient of thermal expansion of carbon/carbon.

  7. On Brauer's problem 21

    Institute of Scientific and Technical Information of China (English)

    ZENG; Jiwen(

    2001-01-01

    [1]Brauer, R., Representations of finite groups, in Lectures in Mathematics, Vol. 1, New York: Wiley, 1963, 133-175.[2]Feit, W. , The Representation Theory of Finite Groups, Amsterdam: North-Holland, 1982.[3]Külshammer, B., Landau's theorem for p-blocks of p-solvable groups, J. Reine Angew. Math., 1990, 404: 189-191.[4]Külshammer B., Robinson, G. R., Alperin-Mckey implies Brauer's problem 21, J. Algebra, 1996, 180: 208-210.[5]Zeng Jiwen, An inequality of block invariants, J. Algebra, 1997, 193: 724-727.[6]Nagao, N., Tsushima, Y., Representations of Finite Groups, New York: Academic Press, Inc., 1989.[7]Robinson, G. R., On Brauer's k(B) problem, J. Algebra, 1992, 147: 450-455.[8]Zhang Jiping, p-regular orbits and p-blocks of defect zero, Comm. Algebra, 1993, 21(1): 299-307.[9]Xu Minyao, Huang ,Jianhua, An Introduction to Finite Groups (in Chinese), Vol. 2, Beijing: Science Press, 1999.[10]Alperin, ,J. L. , Weights for finite group, Proc. Sympos. Pure Math. , 1987, 47: 369-379.[11]Puig, L., Usami, Y., Perfect isometrics for blocks with Abelian defect groups and cyclic four inertial quotients, J. Algebra,1996.[12]Dade, E. C., Counting characters in blocks, I, Invent. Math., 1992, 109: 187-210.

  8. Amazon River carbon dioxide outgassing fuelled by wetlands

    Science.gov (United States)

    Abril, Gwenaël; Martinez, Jean-Michel; Artigas, L. Felipe; Moreira-Turcq, Patricia; Benedetti, Marc F.; Vidal, Luciana; Meziane, Tarik; Kim, Jung-Hyun; Bernardes, Marcelo C.; Savoye, Nicolas; Deborde, Jonathan; Souza, Edivaldo Lima; Albéric, Patrick; Landim de Souza, Marcelo F.; Roland, Fabio

    2014-01-01

    River systems connect the terrestrial biosphere, the atmosphere and the ocean in the global carbon cycle. A recent estimate suggests that up to 3 petagrams of carbon per year could be emitted as carbon dioxide (CO2) from global inland waters, offsetting the carbon uptake by terrestrial ecosystems. It is generally assumed that inland waters emit carbon that has been previously fixed upstream by land plant photosynthesis, then transferred to soils, and subsequently transported downstream in run-off. But at the scale of entire drainage basins, the lateral carbon fluxes carried by small rivers upstream do not account for all of the CO2 emitted from inundated areas downstream. Three-quarters of the world's flooded land consists of temporary wetlands, but the contribution of these productive ecosystems to the inland water carbon budget has been largely overlooked. Here we show that wetlands pump large amounts of atmospheric CO2 into river waters in the floodplains of the central Amazon. Flooded forests and floating vegetation export large amounts of carbon to river waters and the dissolved CO2 can be transported dozens to hundreds of kilometres downstream before being emitted. We estimate that Amazonian wetlands export half of their gross primary production to river waters as dissolved CO2 and organic carbon, compared with only a few per cent of gross primary production exported in upland (not flooded) ecosystems. Moreover, we suggest that wetland carbon export is potentially large enough to account for at least the 0.21 petagrams of carbon emitted per year as CO2 from the central Amazon River and its floodplains. Global carbon budgets should explicitly address temporary or vegetated flooded areas, because these ecosystems combine high aerial primary production with large, fast carbon export, potentially supporting a substantial fraction of CO2 evasion from inland waters.

  9. Carbon-ionogel supercapacitors for integrated microelectronics.

    Science.gov (United States)

    Leung, Greg; Smith, Leland; Lau, Jonathan; Dunn, Bruce; Chui, Chi On

    2016-01-22

    To exceed the performance limits of dielectric capacitors in microelectronic circuit applications, we design and demonstrate on-chip coplanar electric double-layer capacitors (EDLCs), or supercapacitors, employing carbon-coated gold electrodes with ionogel electrolyte. The formation of carbon-coated microelectrodes is accomplished by solution processing and results in a ten-fold increase in EDLC capacitance compared to bare gold electrodes without carbon. At frequencies up to 10 Hz, an areal capacitance of 2.1 pF μm(-2) is achieved for coplanar carbon-ionogel EDLCs with 10 μm electrode gaps and 0.14 mm(2) electrode area. Our smallest devices, comprised of 5 μm electrode gaps and 80 μm(2) of active electrode area, reach areal capacitance values of ∼0.3 pF μm(-2) at frequencies up to 1 kHz, even without carbon. To our knowledge, these are the highest reported values to date for on-chip EDLCs with sub-mm(2) areas. A physical EDLC model is developed through the use of computer-aided simulations for design exploration and optimization of coplanar EDLCs. Through modeling and comparison with experimental data, we highlight the importance of reducing the electrode gap and electrolyte resistance to achieve maximum performance from on-chip EDLCs. PMID:26650708

  10. Carbon-14 waste management

    International Nuclear Information System (INIS)

    Carbon-14 occurs in nature, but is also formed in nuclear reactors. Because of its long half-life and the biological significance of carbon, releases from nuclear facilities could have a significant radiological impact. Waste management strategies for carbon-14 are therefore of current concern. Carbon-14 is present in a variety of waste streams both at reactors and at reprocessing plants. A reliable picture of the production and release of carbon-14 from various reactor systems has been built up for the purposes of this study. A possible management strategy for carbon-14 might be the reduction of nitrogen impurity levels in core materials, since the activation of 14N is usually the dominant source of carbon-14. The key problem in carbon-14 management is its retention of off-gas streams, particularly in the dissolver off-gas stream at reprocessing plants. Three alternative trapping processes that convert carbon dioxide into insoluble carbonates have been suggested. The results show that none of the options considered need be rejected on the grounds of potential radiation doses to individuals. All exposures should be as low as reasonably achievable, economic and social factors being taken into account. If, on these grounds, retention and disposal of carbon-14 is found to be beneficial, then, subject to the limitations noted, appropriate retention, immobilization and disposal technologies have been identified

  11. Mesoporous Carbon for Capacitive Deionization of Saline Water

    Energy Technology Data Exchange (ETDEWEB)

    Tsouris, Costas [ORNL; Mayes, Richard T [ORNL; Kiggans, Jim [ORNL; Sharma, Ms. Ketki [Georgia Institute of Technology; Yiacoumi, Sotira [Georgia Institute of Technology; DePaoli, David W [ORNL; Dai, Sheng [ORNL

    2011-01-01

    Self-assembled mesoporous carbon (MC) materials have been synthesized and tested for application in capacitive deionization (CDI) of saline water. MC was prepared by self-assembly of a triblock copolymer with hydrogen-bonded chains via a phenolic resin, such as resorcinol or phloroglucinol in acidic conditions, followed by carbonization and, in some cases, activation by KOH. Carbon synthesized in this way was ground into powder, from which activated MC sheets were produced. In a variation of this process, after the reaction of triblock copolymer with resorcinol or phloroglucinol, the gel that was formed was used to coat a graphite plate and then carbonized. The coated graphite plate in this case was not activated and was tested to serve as current collector during the CDI process. The performance of these MC materials was compared to that of carbon aerogel for salt concentrations ranging between 1000 ppm and 35,000 ppm. Resorcinol-based MC removed up to 15.2 mg salt per gram of carbon, while carbon aerogel removed 5.8 mg salt per gram of carbon. Phloroglucinol-based MC-coated graphite exhibited the highest ion removal capacity at 21 mg of salt per gram of carbon for 35,000 ppm salt concentration.

  12. Mesoporous carbon for capacitive deionization of saline water.

    Science.gov (United States)

    Tsouris, C; Mayes, R; Kiggans, J; Sharma, K; Yiacoumi, S; DePaoli, D; Dai, S

    2011-12-01

    Self-assembled mesoporous carbon (MC) materials have been synthesized and tested for application in capacitive deionization (CDI) of saline water. MC was prepared by self-assembly of a triblock copolymer with hydrogen-bonded chains via a phenolic resin, such as resorcinol or phloroglucinol in acidic conditions, followed by carbonization and, in some cases, activation by KOH. Carbon synthesized in this way was ground into powder, from which activated MC sheets were produced. In a variation of this process, after the reaction of triblock copolymer with resorcinol or phloroglucinol, the gel that was formed was used to coat a graphite plate and then carbonized. The coated graphite plate in this case was not activated and was tested to serve as current collector during the CDI process. The performance of these MC materials was compared to that of carbon aerogel for salt concentrations ranging between 1000 ppm and 35,000 ppm. Resorcinol-based MC removed up to 15.2 mg salt per gram of carbon, while carbon aerogel removed 5.8 mg salt per gram of carbon. Phloroglucinol-based MC-coated graphite exhibited the highest ion removal capacity at 21 mg of salt per gram of carbon for 35,000 ppm salt concentration. PMID:22032802

  13. Spatial dynamics of carbon storage: a case study from Turkey.

    Science.gov (United States)

    Sivrikaya, Fatih; Baskent, Emin Zeki; Bozali, Nuri

    2013-11-01

    Forest ecosystems have an important role in carbon cycle at both regional and global scales as an important carbon sink. Forest degradation and land cover changes, caused by deforestation and conversion to non-forest area, have a strong impact on carbon storage. The carbon storage of forest biomass and its changes over time in the Hartlap planning unit of the southeastern part of Turkey have been estimated using the biomass expansion factor method based on field measurements of forests plots with forest inventory data between 1991 and 2002. The amount of carbon storage associated with land use and land cover changes were also analyzed. The results showed that the total forested area of the Hartlap planning unit slightly increased by 2.1%, from 27,978.7 ha to 28,282.6 ha during the 11-year period, and carbon storage increased by 9.6%, from 390,367.6 to 427,826.9 tons. Carbon storage of conifer and mixed forests accounted for about 70.6% of carbon storage in 1991, and 67.8% in 2002 which increased by 14,274.6 tons. Land use change and increasing forest area have a strong influence on increasing biomass and carbon storage. PMID:23771281

  14. On Carbon Burning in Super Asymptotic Giant Branch Stars

    CERN Document Server

    Farmer, R; Timmes, F X

    2015-01-01

    We explore the detailed and broad properties of carbon burning in Super Asymptotic Giant Branch (SAGB) stars with 2755 MESA stellar evolution models. The location of first carbon ignition, quenching location of the carbon burning flames and flashes, angular frequency of the carbon core, and carbon core mass are studied as a function of the ZAMS mass, initial rotation rate, and mixing parameters such as convective overshoot, semiconvection, thermohaline and angular momentum transport. In general terms, we find these properties of carbon burning in SAGB models are not a strong function of the initial rotation profile, but are a sensitive function of the overshoot parameter. We quasi-analytically derive an approximate ignition density, $\\rho_{ign} \\approx 2.1 \\times 10^6$ g cm$^{-3}$, to predict the location of first carbon ignition in models that ignite carbon off-center. We also find that overshoot moves the ZAMS mass boundaries where off-center carbon ignition occurs at a nearly uniform rate of $\\Delta M_{\\rm...

  15. A study of the oxygen and carbon dioxide requirements of thermophilic campylobacters.

    OpenAIRE

    Bolton, F J; Coates, D.

    1983-01-01

    The oxygen and carbon dioxide requirements of different biotypes of thermophilic campylobacters were investigated by means of (a) quantitative studies, and (b) total growth studies. Oxygen tolerance of the five test organisms differed markedly and varied with the carbon dioxide concentration. At most carbon dioxide concentrations tested, Campylobacter jejuni strains NCTC 11168 and NCTC 11392 tolerated 21% oxygen (growth reduced), C coli NCTC 11353 tolerated 15% oxygen (growth reduced), and C ...

  16. Densification and microstructure of carbon/carbon composites prepared by chemical vapor infiltration using ethanol as precursor

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Chemical vapor infiltration of carbon fiber felts with uniform initial bulk density of 0.47 g·cm-3 was investigated at the ethanol partial pressures of 5-20 kPa,as well as the temperatures of 1050,1100,1150 and 1200°C.Ethanol,diluted by nitrogen,was employed as the precursor of pyrolytic carbon.Polarized light microscopy(PLM),scanning electron microscopy and X-ray diffraction were adopted to study the texture of pyrolytic carbon deposited at various temperatures.A change from medium-to high-textured pyrolytic carbon was observed in the sample infiltrated at 1050°C.Whereas,homogeneous high-textured pyrolytic carbons were deposited at the temperatures of 1100,1150 and 1200°C.Extinction angles of 19°-21° were determined for different regions in the samples densified at the temperatures ranging from 1100 to 1200°C.Scanning electron microscopy of the fracture surface after bending test indicated that the prepared carbon/carbon composite samples exhibited a pseudo-plastic fracture behavior.In addition,fracture behavior of the carbon/carbon samples was obviously effected by their infiltration temperature.The fracture mode of C/C composites was transformed from shearing failure to tensile breakage with increasing infiltration temperature. Results of this study show that ethanol is a promising carbon source to synthesize carbon/carbon composites with homogeneously high-textured pyrolytic carbon over a wide range of temperatures(from 1100 to 1200°C).

  17. Millimetre observations of infrared carbon stars - I. The data

    NARCIS (Netherlands)

    Sevenster, M; Spoon, HWW; Perez, [No Value

    2002-01-01

    Millimetre observations of IRAS selected red carbon stars are presented. About 260 stars have been observed with SEST and IRAM in the CO (1-0) and CO (2-1) lines and partially in HCN (1-0) and SiO (3-2). An overall detection rate, in at least one line, of about 80% is achieved. The survey represents

  18. Carbon isotopes in mollusk shell carbonates

    Science.gov (United States)

    McConnaughey, Ted A.; Gillikin, David Paul

    2008-10-01

    Mollusk shells contain many isotopic clues about calcification physiology and environmental conditions at the time of shell formation. In this review, we use both published and unpublished data to discuss carbon isotopes in both bivalve and gastropod shell carbonates. Land snails construct their shells mainly from respired CO2, and shell δ13C reflects the local mix of C3 and C4 plants consumed. Shell δ13C is typically >10‰ heavier than diet, probably because respiratory gas exchange discards CO2, and retains the isotopically heavier HCO3 -. Respired CO2 contributes less to the shells of aquatic mollusks, because CO2/O2 ratios are usually higher in water than in air, leading to more replacement of respired CO2 by environmental CO2. Fluid exchange with the environment also brings additional dissolved inorganic carbon (DIC) into the calcification site. Shell δ13C is typically a few ‰ lower than ambient DIC, and often decreases with age. Shell δ13C retains clues about processes such as ecosystem metabolism and estuarine mixing. Ca2+ ATPase-based models of calcification physiology developed for corals and algae likely apply to mollusks, too, but lower pH and carbonic anhydrase at the calcification site probably suppress kinetic isotope effects. Carbon isotopes in biogenic carbonates are clearly complex, but cautious interpretation can provide a wealth of information, especially after vital effects are better understood.

  19. Carbon dioxide sensor

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Prabir K. (Worthington, OH); Lee, Inhee (Columbus, OH); Akbar, Sheikh A. (Hilliard, OH)

    2011-11-15

    The present invention generally relates to carbon dioxide (CO.sub.2) sensors. In one embodiment, the present invention relates to a carbon dioxide (CO.sub.2) sensor that incorporates lithium phosphate (Li.sub.3PO.sub.4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li.sub.2CO.sub.3) and barium carbonate (BaCO.sub.3). In another embodiment, the present invention relates to a carbon dioxide (CO.sub.2) sensor has a reduced sensitivity to humidity due to a sensing electrode with a layered structure of lithium carbonate and barium carbonate. In still another embodiment, the present invention relates to a method of producing carbon dioxide (CO.sub.2) sensors having lithium phosphate (Li.sub.3PO.sub.4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li.sub.2CO.sub.3) and barium carbonate (BaCO.sub.3).

  20. Comparative study on CO2 sources in soil developed on carbonate rock and non-carbonate rock in Central Guizhou

    Institute of Scientific and Technical Information of China (English)

    黎廷宇; 王世杰; 郑乐平

    2002-01-01

    In this paper, by using concentration and carbon stable isotope the CO2 sources of soil profiles developed on limestone, dolostone and claystone basements in Central Guizhou, China are comparatively studied. The results show that CO2 concentration of soil profiles developed on different basements is different, having the following sequence: limestone>dolostone>claystone. Below the soil depth of 20 cm from the surface the ? 13C value of CO2 in soil profile developed on limestone ranges from -12.811‰ - -13.492‰(PDB), that in soil profile developed on dolostone varys from -13.212‰ - -14.271‰(PDB) and that in soil profile developed on claystone is about -20.234‰ - -21.485‰(PDB). Taking the carbon isotope of soil organic matter and carbonate rock as two isotopic endmembers, the proportion of soil CO2 generated by dissolution of carbonate rock is calculated, about 21%-25% for soil profile developed on limestone basement, 19%-21% for soil profile developed on dolostone basement. There is almost no influx of CO2 generated by the dissolution of carbonate rock in soil profile developed on claystone basement.

  1. Plumbing carbon nanotubes

    Science.gov (United States)

    Jin, Chuanhong; Suenaga, Kazu; Iijima, Sumio

    2008-01-01

    Since their discovery, the possibility of connecting carbon nanotubes together like water pipes has been an intriguing prospect for these hollow nanostructures. The serial joining of carbon nanotubes in a controlled manner offers a promising approach for the bottom-up engineering of nanotube structures-from simply increasing their aspect ratio to making integrated carbon nanotube devices. To date, however, there have been few reports of the joining of two different carbon nanotubes. Here we demonstrate that a Joule heating process, and associated electro-migration effects, can be used to connect two carbon nanotubes that have the same (or similar) diameters. More generally, with the assistance of a tungsten metal particle, this technique can be used to seamlessly join any two carbon nanotubes-regardless of their diameters-to form new nanotube structures.

  2. Investigating carbonate formation in urban soils as a method for capture and storage of atmospheric carbon.

    Science.gov (United States)

    Washbourne, C-L; Renforth, P; Manning, D A C

    2012-08-01

    This paper investigates the potential for engineered urban soils to capture and store atmospheric carbon (C). Calcium (Ca) and magnesium (Mg) bearing waste silicate minerals within the soil environment can capture and store atmospheric C through the process of weathering and secondary carbonate mineral precipitation. Anthropogenic soils, known to contain substantial quantities of Ca and Mg-rich minerals derived from demolition activity (particularly cement and concrete), were systematically sampled at the surface across a 10 ha brownfield site, Science Central, located in the urban centre of Newcastle upon Tyne, U.K. Subsequent analysis yielded average carbonate contents of 21.8±4.7% wt CaCO(3). Isotopic analysis demonstrated δ(18)O values between -9.4‰ and -13.3‰ and δ(13)C values between -7.4‰ and -13.6‰ (relative to Pee Dee Belemnite), suggesting that up to 39.4±8.8% of the carbonate C has been captured from the atmosphere through hydroxylation of dissolved CO(2) in high pH solutions. The remaining carbonate C is derived from lithogenic sources. 37.4 kg of atmospheric CO(2) has already been captured and stored as carbonate per Mg of soil across the site, representing a carbon dioxide (CO(2)) removal rate of 12.5 kg CO(2) Mg(-1) yr(-1). There is the potential for capture and storage of a further 27.3 kg CO(2) Mg(-1) in residual reactive materials, which may be exploited through increased residence time (additional in situ weathering). Overall, the Science Central site has the potential to capture and store a total of 64,800 Mg CO(2) as carbonate minerals. This study illustrates the potential for managing urban soils as tools of C capture and storage, an important ecosystem service, and demonstrates the importance of studying C storage in engineering urban anthropogenic soils. PMID:22683756

  3. Nanographene reinforced carbon/carbon composites

    Science.gov (United States)

    Bansal, Dhruv

    Carbon/Carbon Composites (CCC) are made of carbon reinforcement in carbon matrix and have high thermal stability and fatigue resistance. CCC are used in nose cones, heat shields and disc brakes of aircrafts due to their exceptional mechanical properties at high temperature. The manufacturing process of CCC involves a carbonization stage in which unwanted elements, except carbon, are eliminated from the polymer precursor. Carbonization results in the formation of voids and cracks due to the thermal mismatch between the reinforcement and the matrix and expulsion of volatiles from the polymer matrix. Thermal cracks and voids decrease the density and mechanical properties of the manufactured CCC. In this work, Nanographene Platelets (NGP) were explored as nanofillers to fill the voids/cracks and reduce thermal shrinkage in CCC. They were first compared with Vapor Grown Carbon Nanofibers (VGCNF) by dispersion of different concentrations (0.5wt%, 1.5wt%, 3wt%) in resole-type phenolic resin and were characterized to explore their effect on rheology, heat of reaction and wetting behavior. The dispersions were then cured to form nanocomposites and were characterized for morphology, flexure and thermal properties. Finally, NGP were introduced into the carbon/carboncomposites in two stages, first by spraying in different concentrations (0.5wt%, 1.5wt%, 3wt%, 5wt %) during the prepreg formation and later during densification by directly mixing in the corresponding densification mix. The manufactured NGP reinforced CCC were characterized for microstructure, porosity, bulk density and mechanical properties (Flexure and ILSS) which were further cross-checked by non-destructive techniques (vibration and ultrasonic). In this study, it was further found that at low concentration (≤ 1.5 wt%) NGP were more effective in increasing the heat of reaction and in decreasing the viscosity of the phenolic resin. The decrease in viscosity led to better wetting properties of NGP / phenolic

  4. Physics of carbon nanostructures

    International Nuclear Information System (INIS)

    Carbon is a prominent element that appears in various structures with new promising technological applications. The physics of carbon nanostructures is one of the hot topics in modern condensed matter theory. I plan to present a brief introduction into the theory of variously shaped carbon nanostructures paying special attention to generic field-theory models. The preliminary plan is the following: (1) a brief historical excursus, (2) the most interesting experimental observations, (3) generic models for the description of electronic states in carbon nanoparticles (Dirac-type equations, defects, geometry, etc.), (4) open problems. (author)

  5. Carbon Monoxide Toxicity

    Science.gov (United States)

    Aniol, Michael J.

    1992-01-01

    Of all fatal poisonings in the United States, an estimated half are due to carbon monoxide. The number of non-lethal poisonings due to carbon monoxide is difficult to estimate because signs and symptoms of carbon monoxide poisoning cover a wide spectrum and mimic other disorders. Misdiagnosis is serious, as the patient often returns to the contaminated environment. Those not receiving proper treatment are at significant risk, as high as 10% to 12%, of developing late neurological sequelae. The diagnosis of carbon monoxide poisoning depends upon precise history taking, careful physical examination, and a high index of suspicion. ImagesFigure 2 PMID:21221282

  6. Nanoindentation of Carbon Nanostructures.

    Science.gov (United States)

    Kumar, Dinesh; Singh, Karamjit; Verma, Veena; Bhatti, H S

    2016-06-01

    In the present research paper carbon nanostructures viz. single walled carbon nanotubes, multi-walled carbon nanotubes, single walled carbon nanohorns and graphene nanoplatelets have been synthesized by CVD technique, hydrothermal method, DC arc discharge method in liquid nitrogen and microwave technique respectively. After synthesis 5 mm thick pallets of given nanomaterial are prepared by making a paste in isopropyl alcohol and using polyvinylidene difluoride as a binder and then these pallets were used for nanoindentation measurements. Hardness, reduced modulus, stiffness, contact height and contact area have been measured using nanoindenter. PMID:27427726

  7. Agnathia-holoprosencephaly associated with a 46,XY,-21,+t(21q;21q) karyotype

    Energy Technology Data Exchange (ETDEWEB)

    Niedermeyer, K.K.; McCorquodale, M.M.; Burton, B.K. [Univ. of Illinois, Chicago, IL (United States)

    1994-09-01

    We report an unusual case of agnathia-holoprosencephaly associated with Down syndrome due to a 21/21 translocation. The patient presented prenatally at 21 wks gestation. A fetal ultrasound revealed multiple CNS anomalies including hydrocephalus, compressed cerebellum, absent septum pellucidum and possible cranial meningocele or encephalocele. High resolution ultrasound & fetal karyotype were recommended. The patient refused & elected to have a pregnancy termination. Chromosomal analysis performed on products of conception revealed a 46,XY,-21,+t(21q;21q) karyotype. Fluorescence in situ hybridization was performed and confirmed the 21/21 translocation chromosome. An autopsy revealed agnathia and multiple CNS anomalies including absence of the septum pellucidum, absence of the corpus callosum, arhinencephaly, an occiptal meningoencephalocele, dilation of the lateral ventricles, and extensive dysgenesis & heterotopias of the central cerebrum & mid-brain. Additional abnormalities included a persistent left superior vena cava, atrial & ventricular septal defects, irregular length of the fingers with absence of the middle phalanges of the right 2nd and 5th & left 5th digits and bilateral simian creases. Agnathia can be an isolated abnormality but often is associated with holoprosencephaly and/or situs inversus. The majority of familial case of agnathis-holoprosencephaly was caused by an inherited unbalanced translocation resulting in duplication of 6p and monosomy of 18p. Our patient had a translocation form of trisomy 21 but did not have a phenotype consistent with Down syndrome. Trisomy 21 has not been previously reported in other cases of agnathia-holoprosencephaly. Whether the chromosomal abnormality caused the phenotypic abnormalities or if it is a coincidental finding cannot be determined.

  8. 21st Colloquium on African Geology——CAG21

    Institute of Scientific and Technical Information of China (English)

    Lopo Vasconcelos

    2006-01-01

    @@ Under the auspices of the Geological Society of Africa (GSAf), the Geological Mining Association of Mozambique (AGMM) organized the 21st Colloquium on African Geology under the theme "Geoscience for Poverty Relief.

  9. Effect of carbonation on microbial corrosion of concretes

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, N.; Nonaka, T.; Noda, S.; Mori, T. [Shimane Univ., Shimane (Japan)

    1993-09-20

    Carbonation of concrete induces a decrease of surface pH of concrete and is the prerequisite to the generation of microbial corrosion of concrete. Carbonation experiments were conducted on mortar specimens for four months under three different concentrations of carbon dioxide and then, the mortar specimens were subjected to microbial corrosion experiments for eight months by immersion in raw sewage influent. The carbonation rates increased with the increase of CO2 concentration, however, the highest carbonation rate was found in the specimen exposed to 0.5% CO2 compared to 5% CO2 and control (0.03%) specimens. Microbial corrosion rates increased corresponding to the carbonation rates and were 3.0, 3.8, 2.1 mm per year for 5%, 0.5% and control specimens respectively. However, higher CO2 concentration suppresses both carbonation and microbial corrosion rates due to formation of much calcite. Results of on-site investigations show combined effect of H2S and CO2 on actual microbial corrosion. Growth of Thiobacillus thiooxidans is considered to be promoted on the reduced pH of carbonated surface. 6 refs., 11 figs., 4 tabs.

  10. Microbially mediated mineral carbonation

    Science.gov (United States)

    Power, I. M.; Wilson, S. A.; Dipple, G. M.; Southam, G.

    2010-12-01

    Mineral carbonation involves silicate dissolution and carbonate precipitation, which are both natural processes that microorganisms are able to mediate in near surface environments (Ferris et al., 1994; Eq. 1). (Ca,Mg)SiO3 + 2H2CO3 + H2O → (Ca,Mg)CO3 + H2O + H4SiO4 + O2 (1) Cyanobacteria are photoautotrophs with cell surface characteristics and metabolic processes involving inorganic carbon that can induce carbonate precipitation. This occurs partly by concentrating cations within their net-negative cell envelope and through the alkalinization of their microenvironment (Thompson & Ferris, 1990). Regions with mafic and ultramafic bedrock, such as near Atlin, British Columbia, Canada, represent the best potential sources of feedstocks for mineral carbonation. The hydromagnesite playas near Atlin are a natural biogeochemical model for the carbonation of magnesium silicate minerals (Power et al., 2009). Field-based studies at Atlin and corroborating laboratory experiments demonstrate the ability of a microbial consortium dominated by filamentous cyanobacteria to induce the precipitation of carbonate minerals. Phototrophic microbes, such as cyanobacteria, have been proposed as a means for producing biodiesel and other value added products because of their efficiency as solar collectors and low requirement for valuable, cultivable land in comparison to crops (Dismukes et al., 2008). Carbonate precipitation and biomass production could be facilitated using specifically designed ponds to collect waters rich in dissolved cations (e.g., Mg2+ and Ca2+), which would allow for evapoconcentration and provide an appropriate environment for growth of cyanobacteria. Microbially mediated carbonate precipitation does not require large quantities of energy or chemicals needed for industrial systems that have been proposed for rapid carbon capture and storage via mineral carbonation (e.g., Lackner et al., 1995). Therefore, this biogeochemical approach may represent a readily

  11. Novel carbon nanostructures

    International Nuclear Information System (INIS)

    The discovery of carbon nanotubes in 1991 opened up a challenging new area of research, because they are expected to be ideal building blocks for nanoscale applications due to their extraordinary mechanical and electronic properties. Various production methods have been developed, however precise control of nanotube morphology (e.g. length, diameter) has yet to be realised, a fact which has delayed industrial exploitation. Thus a comprehensive understanding of nanotube growth is essential, and this thesis is concerned with this important problem, i.e. the controlled production of novel carbon nanomaterials. Chapter 1 surveys production methods for fullerenes, carbon nanotubes and other carbon-based materials, such as fibres, particles etc. The sophisticated tools required for this work, e.g. high resolution transmission electron microscopy (HRTEM), high resolution electron energy loss spectroscopy (HREELS), etc. are reviewed in Chapter 2. Chapter 3 describes a novel approach to carbon nanotubes, using laser etching techniques, which generates aligned tubes of uniform diameter and length. The mode of catalyst preparation, as well as the nature of the precursor, play crucial roles in this process. The preparation of modified carbon nanotubes by the pyrolysis of metallocene, e.g. ferrocene in conjunction with various hydrocarbons, is discussed in Chapter 4. Superconducting interference device measurements (SQUID) show that Fe-filled carbon nanotubes exhibit enhanced coercivities in the 430-1070 Oe range, i.e. greater than those reported for Ni and Co nanowires. Carbon nanotubes can be also modified by replacing atoms of the carbon network with nitrogen, boron or both. The creation of large arrays of nitrogen-doped carbon nanotubes, for example CNx nanofibres, as well as the formation of BxCyNz onions is described in Chapter 5. Electron irradiation of these onions generates pure carbon onions. Finally (Chapter 6), the catalytic behaviour of metal particles in different

  12. Characterization of Biochar from Switchgrass Carbonization

    Directory of Open Access Journals (Sweden)

    Samy Sadaka

    2014-01-01

    Full Text Available Switchgrass is a high yielding, low-input intensive, native perennial grass that has been promoted as a major second-generation bioenergy crop. Raw switchgrass is not a readily acceptable feedstock in existing power plants that were built to accommodate coal and peat. The objective of this research was to elucidate some of the characteristics of switchgrass biochar produced via carbonization and to explore its potential use as a solid fuel. Samples were carbonized in a batch reactor under reactor temperatures of 300, 350 and 400 °C for 1, 2 and 3 h residence times. Biochar mass yield and volatile solids decreased from 82.6% to 35.2% and from 72.1% to 43.9%, respectively, by increasing carbonization temperatures from 300 °C to 400 °C and residence times from 1 h to 3 h. Conversely, biochar heating value (HV and fixed carbon content increased from 17.6 MJ kg−1 to 21.9 MJ kg−1 and from 22.5% to 44.9%, respectively, under the same conditions. A biomass discoloration index (BDI was created to quantify changes in biochar colors as affected by the two tested parameters. The maximum BDI of 77% was achieved at a carbonization temperature of 400 °C and a residence time of 3 h. The use of this index could be expanded to quantify biochar characteristics as affected by thermochemical treatments. Carbonized biochar could be considered a high quality solid fuel based on its energy content.

  13. Nanoscale fluid transportation through individual carbon nanotubes

    Science.gov (United States)

    He, Jin; Cao, Di; Pang, Pei; Luo, Tao; Lindsay, Stuart; Kristic, Predrag; Nuckolls, Colin

    2011-03-01

    There are great interest in both simulation and experiment of fluid flow on the nanoscale. Carbon nanotubes, with their extremely small inner diameter (usually below 2 nm) and atomic smooth inner surface, are ideal materials for studying nanoconfinement and ion and molecule nanoscale translocation. The excellent electrical properties of CNTs can also be integrated to achieve nanoelectrofluidic device. This presentation describes our recent progress in studying fluid transport through individual carbon nanotubes, including simultaneously ionic and electronic measurements during water, ion and molecule translocation. This work was supported by the DNA Sequencing Technology Program of the National Human Genome Research Institute (1RC2HG005625-01, 1R21HG004770-01).

  14. Ultrahigh carbon steels, Damascus steels, and superplasticity

    Energy Technology Data Exchange (ETDEWEB)

    Sherby, O.D. [Stanford Univ., CA (United States). Dept. of Materials Science and Engineering; Wadsworth, J. [Lawrence Livermore National Lab., CA (United States)

    1997-04-01

    The processing properties of ultrahigh carbon steels (UHCSs) have been studied at Stanford University over the past twenty years. These studies have shown that such steels (1 to 2.1% C) can be made superplastic at elevated temperature and can have remarkable mechanical properties at room temperature. It was the investigation of these UHCSs that eventually brought us to study the myths, magic, and metallurgy of ancient Damascus steels, which in fact, were also ultrahigh carbon steels. These steels were made in India as castings, known as wootz, possibly as far back as the time of Alexander the Great. The best swords are believed to have been forged in Persia from Indian wootz. This paper centers on recent work on superplastic UHCSs and on their relation to Damascus steels. 32 refs., 6 figs.

  15. Corrosion of carbon-alloyed iron aluminides

    Indian Academy of Sciences (India)

    M Sen; R Balasubramaniam; A V Ramesh Kumar

    2000-10-01

    The corrosion behaviour of two carbon-alloyed intermetallics of composition Fe–28.1Al–2.1C and Fe–27.5Al–3.7C has been studied and compared with that of binary intermetallics. Potentiodynamic polarization studies indicated that the intermetallics exhibited active–passive behaviour in an acidic solution of pH = 1, whereas they exhibited stable passivity in a buffer solution of pH 8.4. Corrosion rates were also obtained by immersion testing. The variation of corrosion rate as a function of time was similar for both the intermetallics. The variation in corrosion rate as a function of time has been explained based on the observed potentiodynamic polarization behaviour. Scanning electron microscopy of corroded surfaces indicated that the carbon-alloyed intermetallics were susceptible to galvanic corrosion, due to the presence of carbides.

  16. Method for Making a Carbon-Carbon Cylinder Block

    Science.gov (United States)

    Ransone, Phillip O. (Inventor)

    1997-01-01

    A method for making a lightweight cylinder block composed of carbon-carbon is disclosed. The use of carbon-carbon over conventional materials. such as cast iron or aluminum, reduces the weight of the cylinder block and improves thermal efficiency of the internal combustion reciprocating engine. Due to the negligible coefficient of thermal expansion and unique strength at elevated temperatures of carbon-carbon, the piston-to-cylinder wall clearance can be small, especially when the carbon-carbon cylinder block is used in conjunction with a carbon-carbon piston. Use of the carbon-carbon cylinder block has the effect of reducing the weight of other reciprocating engine components allowing the piston to run at higher speeds and improving specific engine performance.

  17. Carbon balance of Russian agricultural land

    Science.gov (United States)

    Schepaschenko, D.; Shvidenko, A.; Schepaschenko, M.

    2012-04-01

    Russia managed 218.7 mln ha agricultural land (2009) in accordance with national statistics (FSSS, 2011: http://www.gks.ru/dbscripts/Cbsd/DBInet.cgi#1). Among that, 91.75 mln ha is arable land; 92.05 mln ha - hayfield and pasture; 34.9 mln ha - abandoned arable and fallow. Abandoned arable area is not indicated directly in the statistics, but can be calculated as a difference between "arable" and "cultivated" area. We estimated carbon balance of agricultural land by accounting carbon fluxes. Carbon sink includes: net primary productivity (NPP), applying fertilizes and liming. Carbon losses include soil respiration (SR), harvest and lateral flux. The initial data (cultivated area and harvest distribution by regions and crop) was derived from national agriculture statistics (FSSS, 2011). NPP was estimated via harvest and set of regression models. Average NPP for agricultural land was estimated at 435 g C m-2 (530 g C m-2 for crops). Soil respiration was calculated by a model (Mukhortova et. al., 1011: http://www.iiasa.ac.at/Research/FOR/forest_cdrom/Articles/Mukhortova_2011_IBFRA_SR.pdf) developed for Russia which is based on all available empirical data and accounted for climatic parameters, soil type and management practice. Average SR of agricultural land is 344 g C m-2 (372 g C m-2 for the cropland). We applied the IPCC method (National inventory, 2010; IPCC, 2006) for fertilizer and lateral fluxes assessment. The total carbon balance of agricultural land is almost in equilibrium (-0.04 t C ha-1) in spite of arable land is a carbon source (-0.84 t C ha-1). The highest sink (1.21 t C ha-1) is provided by abandoned land. Carbon fluxes vary substantially depending on seasonal weather conditions. For example grains' NPP in 2010 (dry and hot summer in major agricultural regions of European Russia) was estimated at 32% less compare to 2009 and the total carbon balance of this land category decreased by order of magnitude. We used Russian land cover (Schepaschenko et al

  18. Carbon isotopic composition of individual Precambrian microfossils

    Science.gov (United States)

    House, C. H.; Schopf, J. W.; McKeegan, K. D.; Coath, C. D.; Harrison, T. M.; Stetter, K. O.

    2000-01-01

    Ion microprobe measurements of carbon isotope ratios were made in 30 specimens representing six fossil genera of microorganisms petrified in stromatolitic chert from the approximately 850 Ma Bitter Springs Formation, Australia, and the approximately 2100 Ma Gunflint Formation, Canada. The delta 13C(PDB) values from individual microfossils of the Bitter Springs Formation ranged from -21.3 +/- 1.7% to -31.9 +/- 1.2% and the delta 13C(PDB) values from microfossils of the Gunflint Formation ranged from -32.4 +/- 0.7% to -45.4 +/- 1.2%. With the exception of two highly 13C-depleted Gunflint microfossils, the results generally yield values consistent with carbon fixation via either the Calvin cycle or the acetyl-CoA pathway. However, the isotopic results are not consistent with the degree of fractionation expected from either the 3-hydroxypropionate cycle or the reductive tricarboxylic acid cycle, suggesting that the microfossils studied did not use either of these pathways for carbon fixation. The morphologies of the microfossils suggest an affinity to the cyanobacteria, and our carbon isotopic data are consistent with this assignment.

  19. Carbon isotopic composition of individual Precambrian microfossils.

    Science.gov (United States)

    House, C H; Schopf, J W; McKeegan, K D; Coath, C D; Harrison, T M; Stetter, K O

    2000-08-01

    Ion microprobe measurements of carbon isotope ratios were made in 30 specimens representing six fossil genera of microorganisms petrified in stromatolitic chert from the approximately 850 Ma Bitter Springs Formation, Australia, and the approximately 2100 Ma Gunflint Formation, Canada. The delta 13C(PDB) values from individual microfossils of the Bitter Springs Formation ranged from -21.3 +/- 1.7% to -31.9 +/- 1.2% and the delta 13C(PDB) values from microfossils of the Gunflint Formation ranged from -32.4 +/- 0.7% to -45.4 +/- 1.2%. With the exception of two highly 13C-depleted Gunflint microfossils, the results generally yield values consistent with carbon fixation via either the Calvin cycle or the acetyl-CoA pathway. However, the isotopic results are not consistent with the degree of fractionation expected from either the 3-hydroxypropionate cycle or the reductive tricarboxylic acid cycle, suggesting that the microfossils studied did not use either of these pathways for carbon fixation. The morphologies of the microfossils suggest an affinity to the cyanobacteria, and our carbon isotopic data are consistent with this assignment.

  20. The Social Cost of Carbon Emissions

    OpenAIRE

    Duncan Foley; Lance Taylor

    2013-01-01

    Determining the social cost of carbon emissions (SCC) is a crucial step in the economic analysis of climate change policy as the US government’s recent decision to use a range of estimates of the SCC centered at $77/tC (or, equivalently, $21/tCO2) in cost-benefit analyses of proposed emission-control legislation underlines. This note reviews the welfare economics theory fundamental to the estimation of the SCC in both static and intertemporal contexts, examining the effects of assumptions abo...

  1. The Social Cost of Carbon Emissions

    OpenAIRE

    Duncan Foley; Lance Taylor; Armon Rezai

    2013-01-01

    Determining the social cost of carbon emissions (SCC) is a crucial step in the economic analysis of climate change policy as the US government's recent decision to use a range of estimates of the SCC centered at $77/tC (or, equivalently, $21/tCO2) in cost-benefit analyses of proposed emission-control legislation underlines. This note reviews the welfare economics theory fundamental to the estimation of the SCC in both static and intertemporal contexts, examining the effects of assumptions abo...

  2. Neutral Atomic Carbon in Centers of Galaxies

    OpenAIRE

    Israel, F.P.; Baas, F

    2001-01-01

    We present measurements of the emission from the centers of fifteen spiral galaxies in the 3P1-3P0 [CI] fine-structure transition at 492 GHz. Observed galaxy centers range from quiescent to starburst to active. The intensities of neutral carbon, the J=2-1 transition of 13CO and the J=4-3 transition of 12CO are compared in matched beams. Most galaxy centers emit more strongly in [CI] than in 13CO, completely unlike the situation pertaining to Galactic molecular cloud regions. [CI] intensities ...

  3. Carbon Budget of Bastard Halibut Paralichthys Oliva-eus in Relation to Body Weight and Temperature

    Institute of Scientific and Technical Information of China (English)

    线薇薇; 刘瑞玉; 朱鑫华

    2003-01-01

    The effects of body weight and temperature on the carbon budget of the juvenile bastard halibut, Paralichthys olivaceus , were studied at temperature 13.5, 18, 21.5 and 24 ℃, respectively. The carbon intake, faecal and growth carbon were measured, and the carbon respiration was calculated using the carbon budget equation(CC=GC+FC+RC). The combined relationship between different components of the carbon budget, body weight and temperature could be described by regression equations: CC =1.0206 W 0.8126 e 0.1483 T; G=0.0042 W 1.4096 (-5.11 T 3+285.90 T2-5173.72 T +30314.03); FC =0.0485 W0.7711e 0.1624 T ; UC = 1.4333 W 0.6715e 0.1487 T. Body weight had no significant ffect on the carbon absorption efficiency and the conversion efficiency.

  4. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Consumers Businesses Contact CPSC Website Design Feedback Consumers: Español Businesses: Español , 中文 , Tiếng Việt Connect with Us : Twitter YouTube ... Safely Home / Safety Education / Safety Education Centers En Español Carbon Monoxide Information Center The Invisible Killer Carbon ...

  5. Carbon black recovery

    International Nuclear Information System (INIS)

    A process and apparatus for recovering carbon black from hot smoke which comprises passing the smoke through a cyclone separation zone following cooling, then through aggregate filter beds and regeneration of filter beds with clean off-gas which is recycled to the carbon black reaction zone as quench

  6. Carbon for sensing devices

    CERN Document Server

    Tagliaferro, Alberto

    2015-01-01

    This book reveals why carbon is playing such an increasingly prominent role as a sensing material. The various steps that transform a raw material in a sensing device are thoroughly presented and critically discussed.  The authors deal with all aspects of carbon-based sensors, starting from the various hybridization and allotropes of carbon, with specific focus on micro and nanosized carbons (e.g., carbon nanotubes, graphene) and their growth processes. The discussion then moves to the role of functionalization and the different routes to achieve it. Finally, a number of sensing applications in various fields are presented, highlighting the connection with the basic properties of the various carbon allotropes.  Readers will benefit from this book’s bottom-up approach, which starts from the local bonding in carbon solids and ends with sensing applications, linking the local hybridization of carbon atoms and its modification by functionalization to specific device performance. This book is a must-have in th...

  7. Fly ash carbon passivation

    Science.gov (United States)

    La Count, Robert B; Baltrus, John P; Kern, Douglas G

    2013-05-14

    A thermal method to passivate the carbon and/or other components in fly ash significantly decreases adsorption. The passivated carbon remains in the fly ash. Heating the fly ash to about 500 and 800 degrees C. under inert gas conditions sharply decreases the amount of surfactant adsorbed by the fly ash recovered after thermal treatment despite the fact that the carbon content remains in the fly ash. Using oxygen and inert gas mixtures, the present invention shows that a thermal treatment to about 500 degrees C. also sharply decreases the surfactant adsorption of the recovered fly ash even though most of the carbon remains intact. Also, thermal treatment to about 800 degrees C. under these same oxidative conditions shows a sharp decrease in surfactant adsorption of the recovered fly ash due to the fact that the carbon has been removed. This experiment simulates the various "carbon burnout" methods and is not a claim in this method. The present invention provides a thermal method of deactivating high carbon fly ash toward adsorption of AEAs while retaining the fly ash carbon. The fly ash can be used, for example, as a partial Portland cement replacement in air-entrained concrete, in conductive and other concretes, and for other applications.

  8. Carbon Capture and Storage

    NARCIS (Netherlands)

    Benson, S.M.; Bennaceur, K.; Cook, P.; Davison, J.; Coninck, H. de; Farhat, K.; Ramirez, C.A.; Simbeck, D.; Surles, T.; Verma, P.; Wright, I.

    2012-01-01

    Emissions of carbon dioxide, the most important long-lived anthropogenic greenhouse gas, can be reduced by Carbon Capture and Storage (CCS). CCS involves the integration of four elements: CO 2 capture, compression of the CO2 from a gas to a liquid or a denser gas, transportation of pressurized CO 2

  9. COMMITTED TO CARBON REDUCTION

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Chinese efforts to lower carbon emissions through environmentally friendly means begin gaining momentum Efforts to curb carbon emissions continue to take shape as China adheres to its pledge for a brighter, greener future. More importantly, as environmental measures take hold and develop

  10. Amorphous iron (II) carbonate

    DEFF Research Database (Denmark)

    Sel, Ozlem; Radha, A.V.; Dideriksen, Knud;

    2012-01-01

    Abstract The synthesis, characterization and crystallization energetics of amorphous iron (II) carbonate (AFC) are reported. AFC may form as a precursor for siderite (FeCO3). The enthalpy of crystallization (DHcrys) of AFC is similar to that of amorphous magnesium carbonate (AMC) and more...

  11. Carbon Dioxide Fountain

    Science.gov (United States)

    Kang, Seong-Joo; Ryu, Eun-Hee

    2007-01-01

    This article presents the development of a carbon dioxide fountain. The advantages of the carbon dioxide fountain are that it is odorless and uses consumer chemicals. This experiment also is a nice visual experiment that allows students to see evidence of a gaseous reagent being consumed when a pressure sensor is available. (Contains 3 figures.)…

  12. Carbon dioxide recycling

    Science.gov (United States)

    The recycling of carbon dioxide to methanol and dimethyl ether is seen to offer a substantial route to renewable and environmentally carbon neutral fuels. One of the authors has championed the “Methanol Economy" in articles and a book. By recycling ambient CO2, the authors argue ...

  13. De-carbonizingChina

    Institute of Scientific and Technical Information of China (English)

    zhou; Xiaoyan

    2013-01-01

    Innovation in the energy sector will pave the way for the country’slow-carbon future Although its per-capita emission is roughly on par with the world’s average, China is the world’s largest carbon dioxide emitter,

  14. THE BEATLES 2.1

    DEFF Research Database (Denmark)

    Nielsen, Steen Kaargaard

    2010-01-01

    Blog-essay publiceret på følgende web-adresse: www.avlyt.dk/2010/04/the-beatles-2-1-om-emis-forvaltning-af-the-fab-fours-lydværk-og-værklyd......Blog-essay publiceret på følgende web-adresse: www.avlyt.dk/2010/04/the-beatles-2-1-om-emis-forvaltning-af-the-fab-fours-lydværk-og-værklyd...

  15. Investigating carbonate formation in urban soils as a method for capture and storage of atmospheric carbon

    International Nuclear Information System (INIS)

    This paper investigates the potential for engineered urban soils to capture and store atmospheric carbon (C). Calcium (Ca) and magnesium (Mg) bearing waste silicate minerals within the soil environment can capture and store atmospheric C through the process of weathering and secondary carbonate mineral precipitation. Anthropogenic soils, known to contain substantial quantities of Ca and Mg-rich minerals derived from demolition activity (particularly cement and concrete), were systematically sampled at the surface across a 10 ha brownfield site, Science Central, located in the urban centre of Newcastle upon Tyne, U.K. Subsequent analysis yielded average carbonate contents of 21.8 ± 4.7% wt CaCO3. Isotopic analysis demonstrated δ18O values between − 9.4‰ and − 13.3‰ and δ13C values between − 7.4‰ and − 13.6‰ (relative to Pee Dee Belemnite), suggesting that up to 39.4 ± 8.8% of the carbonate C has been captured from the atmosphere through hydroxylation of dissolved CO2 in high pH solutions. The remaining carbonate C is derived from lithogenic sources. 37.4 kg of atmospheric CO2 has already been captured and stored as carbonate per Mg of soil across the site, representing a carbon dioxide (CO2) removal rate of 12.5 kgCO2 Mg−1 yr−1. There is the potential for capture and storage of a further 27.3 kgCO2 Mg−1 in residual reactive materials, which may be exploited through increased residence time (additional in situ weathering). Overall, the Science Central site has the potential to capture and store a total of 64,800 Mg CO2 as carbonate minerals. This study illustrates the potential for managing urban soils as tools of C capture and storage, an important ecosystem service, and demonstrates the importance of studying C storage in engineering urban anthropogenic soils. Highlights: ► Urban soils potentially capture 12.5 kgCO2 Mg−1 yr−1 (value £51,843–£77,765 ha−1). ► Formation of carbonate may be significant and exploitable storage

  16. Potential reduction of carbon emissions from Crude Palm Oil production based on energy and carbon balances

    International Nuclear Information System (INIS)

    Highlights: ► We evaluate energy and carbon equivalence from CPO production based on a CBM. ► Energy spent and produced via carbon movement from palm oil mill was determined. ► Scenarios were formulated to evaluate the potential reduction of carbon emission. ► Utilization of biomass from palm oil mill shows the high potential of C-reduction. -- Abstract: This study aimed to evaluate energy and carbon equivalences (CE) associated with palm oil milling and to evaluate sustainability alternatives for energy consumption. Appropriate ways to reduce carbon emissions were also evaluated. A field survey was carried out to quantify the input and output of energy and materials following the conceptual framework of a carbon-balanced model (CBM), which exclude other non-CO2 greenhouse gases. Survey results indicate that the electrical energy consumption for daily mill start-up averaged 18.7 ± 5.4 kWh/ton Fresh Fruit Bunches (FFBs). This energy is equivalent to 114.4 ± 33.2 kWh/ton Crude Palm Oil (CPO) which was found to be offset by that generated in the mills using palm fiber as a solid fuel. Currently, organic residues contained in the wastewater are anaerobically converted to methane. The methane is used as fuel to generate electricity and sold to an outside grid network at a generation rate of 8.1 ± 2.1 kWh/ton FFB. Based on the CBM approach, carbon emissions observed from the use of fossil energy in palm oil milling were very small; however, total carbon emission from oil palm plantation and palm oil milling were found to be 12.3 kg CE/ton FFB, resulting in the net carbon reduction in CPO production of 2.8 kg CE/ton FFB or 53.7 kg CE/ha-y. Overall, the sum of C-reduction was found 1.2 times greater than that of C-emission. This figure can be increased up to 5.5, if all biomass by-products are used as fuel to generate electricity only. The full potential for carbon reduction from palm oil milling is estimated at 0.94 kW of electric power for every hectare of

  17. Carbonate hosted gold deposit in Tasmania, Australia

    International Nuclear Information System (INIS)

    mineralisation. Oxygen isotope values of gold-bearing carbonate from Beaconsfield (-6.3 to -17.7 per mil VPDB) and Henty (20.98 to -21.49 per mil VPDB) are negative compared to modern marine calcite (+0.5 to -1 per mil VPDB). The very depleted oxygen isotope values along with elemental compositions and palaeotemperature calculation indicate the presence of hot meteoric fluids during gold mineralisation (Rao and Adabi, 1999).Carbon isotope values in both Beaconsfield and Henty carbonates are lower (-0.4 to -5.3 per mil VPDB) than modern marine calcite (0 to +4 per mil. VPDB) due to dissolution of large concentration of carbonate prior to gold mineralisation and this is likely to have increased Ph of gold-bearing fluid and promoted gold precipitation. Copyright (1999) Geological Society of Australia

  18. Benthic foraminiferal fauna turnover at 2.1 Ma in the northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    HUANG BaoQi; JIAN ZhiMin; WANG PinXian

    2007-01-01

    Quantitative analysis of benthic foraminifera from ODP Site 1146 in the northern South China Sea (SCS)shows that abundance of Bulimina alazanensis, sometimes up to about 90%, decreased gradually since 3.2 Ma, especially at 2.1 Ma. Abundance of other benthic foraminiferal species, Globobulimina subglobosa and Cibicidoides wuellerstorfi, increased after 2.1 Ma. Comparison with changes in oxygen and carbon isotopes of planktonic and benthic foraminifera shows that high abundance values of B.alazanensis corresponded with lower values of oxygen isotope, but for carbon isotope, high values of the species were consistent with heavier carbon Isotope of benthic foraminifera and lighter carbon isotope of planktonic foraminifera, respectively, and vice versa. Considering factors such as uplift of Bashi Strait, expansion of the North Hemisphere Glaciation, strengthening of East Asian winter monsoon and variations in oxygen and carbon isotope of foraminifera, changes of B. alazanensis in ODP Site 1146 suggest that the source of deep water masses of the northern South China Sea changed from the warm Pacific deep water with high oxygen content to Pacific Intermediate water with Iow oxygen content at 2.1 Ma. In addition, the strengthened East Asian winter monsoon resulted in increased primary productivity, high nutrient and suboxic bottom water. Variations in species of B. alazanensis seemed to be unable to tolerate environmental stress induced by deep water masses and productivity changes.

  19. Major carbon industries in India

    Energy Technology Data Exchange (ETDEWEB)

    Jain, P.K.

    1982-01-01

    The history of the major carbon industries in India, their growth, present status, problems and future prospects are described. Chapters cover: raw petroleum coke, calcined petroleum coke, graphite electrodes and anodes, carbon electrode paste, calcined anthracite coal, low-ash metallurgical coke, carbon black industry, activated carbon, midget electrodes, cinema arc carbons, carbon blocks and brushes for electrical machinery, and the growth of the aluminium industry and its impact on the calcined petroleum coke industry.

  20. Synthesis of hydrated lutetium carbonate

    Energy Technology Data Exchange (ETDEWEB)

    Song Liu [South China Univ. of Technology, Dept. of Applied Chemistry, Guangdong (China); Rong-jun Ma [Changsha Research Institute of Minig and Metallurgy, Hunan (China)

    1997-09-01

    Crystalline lutetium carbonate was synthesized for the corresponding chloride using ammonium bicarbonate as precipitant. The chemical analyses suggest that the synthesized lutetium carbonate is a hydrated basic carbonate or oxycarbonate. The X-ray powder diffraction data are presented. The IR data for the compound show the presence of two different carbonate groups. There is no stable intermediate carbonate in the process of thermal decomposition of the lutetium carbonate. (au) 15 refs.

  1. China’s Forests and Their Impact on Global Carbon Cycle

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Forests have multiple benefits and functions, including mitigation of climate change. The impacts of forests on the global carbon cycle include forests as carbon sinks, wood-based products as carbon sinks, bio-energy, and production and use of non-timber products. In the past decades, forest cover of China has increased from 8.6% to 18.21% by large-scale afforestation and conversion of cropland into forests. Forest biomass carbon (C) stock increased from 4.3 Pg C (1 Pg C = 1 015 g C) in the early 1980s to 5...

  2. Environmental change and the carbon balance of Amazonian forests.

    Science.gov (United States)

    Aragão, Luiz E O C; Poulter, Benjamin; Barlow, Jos B; Anderson, Liana O; Malhi, Yadvinder; Saatchi, Sassan; Phillips, Oliver L; Gloor, Emanuel

    2014-11-01

    Extreme climatic events and land-use change are known to influence strongly the current carbon cycle of Amazonia, and have the potential to cause significant global climate impacts. This review intends to evaluate the effects of both climate and anthropogenic perturbations on the carbon balance of the Brazilian Amazon and to understand how they interact with each other. By analysing the outputs of the Intergovernmental Panel for Climate Change (IPCC) Assessment Report 4 (AR4) model ensemble, we demonstrate that Amazonian temperatures and water stress are both likely to increase over the 21st Century. Curbing deforestation in the Brazilian Amazon by 62% in 2010 relative to the 1990s mean decreased the Brazilian Amazon's deforestation contribution to global land use carbon emissions from 17% in the 1990s and early 2000s to 9% by 2010. Carbon sources in Amazonia are likely to be dominated by climatic impacts allied with forest fires (48.3% relative contribution) during extreme droughts. The current net carbon sink (net biome productivity, NBP) of +0.16 (ranging from +0.11 to +0.21) Pg C year(-1) in the Brazilian Amazon, equivalent to 13.3% of global carbon emissions from land-use change for 2008, can be negated or reversed during drought years [NBP = -0.06 (-0.31 to +0.01) Pg C year(-1) ]. Therefore, reducing forest fires, in addition to reducing deforestation, would be an important measure for minimizing future emissions. Conversely, doubling the current area of secondary forests and avoiding additional removal of primary forests would help the Amazonian gross forest sink to offset approximately 42% of global land-use change emissions. We conclude that a few strategic environmental policy measures are likely to strengthen the Amazonian net carbon sink with global implications. Moreover, these actions could increase the resilience of the net carbon sink to future increases in drought frequency. PMID:25324039

  3. Enhancing the capacitances of electric double layer capacitors based on carbon nanotube electrodes by carbon dioxide activation and acid oxidization

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Polarizable electrodes of electric double layer capacitors(EDLCs) were made from carbon nanotubes(CNTs).Effect of carbon dioxide activation together with acid oxidation for the electrodes on the characteristics and performances of electrodes and EDLCs was studied.Carbon dioxide activation changed the microstructure of the electrodes,increased the effective surface area of CNTs and optimized the distribution of apertures of the electrodes.Acid oxidization modified the surface characteristics of CNTs.Based on the polarizable electrodes treated by carbon dioxide activation and acid oxidization,the performances of EDLCs were greatly enhanced.The specific capacitance of the electrodes with organic electrolyte was increased from 21.8 F/g to 60.4 F/g.

  4. Asphalt-derived high surface area activated porous carbons for carbon dioxide capture.

    Science.gov (United States)

    Jalilov, Almaz S; Ruan, Gedeng; Hwang, Chih-Chau; Schipper, Desmond E; Tour, Josiah J; Li, Yilun; Fei, Huilong; Samuel, Errol L G; Tour, James M

    2015-01-21

    Research activity toward the development of new sorbents for carbon dioxide (CO2) capture have been increasing quickly. Despite the variety of existing materials with high surface areas and high CO2 uptake performances, the cost of the materials remains a dominant factor in slowing their industrial applications. Here we report preparation and CO2 uptake performance of microporous carbon materials synthesized from asphalt, a very inexpensive carbon source. Carbonization of asphalt with potassium hydroxide (KOH) at high temperatures (>600 °C) yields porous carbon materials (A-PC) with high surface areas of up to 2780 m(2) g(-1) and high CO2 uptake performance of 21 mmol g(-1) or 93 wt % at 30 bar and 25 °C. Furthermore, nitrogen doping and reduction with hydrogen yields active N-doped materials (A-NPC and A-rNPC) containing up to 9.3% nitrogen, making them nucleophilic porous carbons with further increase in the Brunauer-Emmett-Teller (BET) surface areas up to 2860 m(2) g(-1) for A-NPC and CO2 uptake to 26 mmol g(-1) or 114 wt % at 30 bar and 25 °C for A-rNPC. This is the highest reported CO2 uptake among the family of the activated porous carbonaceous materials. Thus, the porous carbon materials from asphalt have excellent properties for reversibly capturing CO2 at the well-head during the extraction of natural gas, a naturally occurring high pressure source of CO2. Through a pressure swing sorption process, when the asphalt-derived material is returned to 1 bar, the CO2 is released, thereby rendering a reversible capture medium that is highly efficient yet very inexpensive. PMID:25531980

  5. Asphalt-derived high surface area activated porous carbons for carbon dioxide capture.

    Science.gov (United States)

    Jalilov, Almaz S; Ruan, Gedeng; Hwang, Chih-Chau; Schipper, Desmond E; Tour, Josiah J; Li, Yilun; Fei, Huilong; Samuel, Errol L G; Tour, James M

    2015-01-21

    Research activity toward the development of new sorbents for carbon dioxide (CO2) capture have been increasing quickly. Despite the variety of existing materials with high surface areas and high CO2 uptake performances, the cost of the materials remains a dominant factor in slowing their industrial applications. Here we report preparation and CO2 uptake performance of microporous carbon materials synthesized from asphalt, a very inexpensive carbon source. Carbonization of asphalt with potassium hydroxide (KOH) at high temperatures (>600 °C) yields porous carbon materials (A-PC) with high surface areas of up to 2780 m(2) g(-1) and high CO2 uptake performance of 21 mmol g(-1) or 93 wt % at 30 bar and 25 °C. Furthermore, nitrogen doping and reduction with hydrogen yields active N-doped materials (A-NPC and A-rNPC) containing up to 9.3% nitrogen, making them nucleophilic porous carbons with further increase in the Brunauer-Emmett-Teller (BET) surface areas up to 2860 m(2) g(-1) for A-NPC and CO2 uptake to 26 mmol g(-1) or 114 wt % at 30 bar and 25 °C for A-rNPC. This is the highest reported CO2 uptake among the family of the activated porous carbonaceous materials. Thus, the porous carbon materials from asphalt have excellent properties for reversibly capturing CO2 at the well-head during the extraction of natural gas, a naturally occurring high pressure source of CO2. Through a pressure swing sorption process, when the asphalt-derived material is returned to 1 bar, the CO2 is released, thereby rendering a reversible capture medium that is highly efficient yet very inexpensive.

  6. Global Warming in the 21st Century: An Alternate Scenario

    Science.gov (United States)

    Hansen, James E.

    2000-01-01

    Evidence on a broad range of time scales, from Proterozoic to the most recent periods, shows that the Earth's climate responds sensitively to global forcings. In the past few decades the Earth's surface has warmed rapidly, apparently in response to increasing anthropogenic greenhouse gases in the atmosphere. The conventional view is that the current global warming rate will continue or accelerate in the 21st century. I will describe an alternate scenario that would slow the rate of global warming and reduce the danger of dramatic climate change. But reliable prediction of future climate change requires improved knowledge of the carbon cycle and global observations that allow interpretation of ongoing climate change.

  7. Comparative study on CO2 sources in soil developed on carbonate rock and non-carbonate rock in Central Guizhou

    Institute of Scientific and Technical Information of China (English)

    黎廷宇; 王世杰; 郑乐平

    2002-01-01

    In this paper, by using concentration and carbon stable isotope the.CO2 sources of soil profiles developed on limestone, dolostone and claystone basements in Central Guizhou, China are comparatively studied. The results show that CO2 concentration of soil profiles developed on different basements is different, having the following sequence: limestone>dolostone>claystone. Below the soil depth of 20 cm from the surface the δ13C value of CO2 in soil profile developed on limestone ranges from -12.811‰ - -13.492‰(PDB), that in soil profile developed on dolostone varys from -13.212‰--14.271‰(PDB) and that in soil profile developed on claystone is about -20.234‰- -21.485‰(PDB). Taking the carbon isotope of soil organic matter and carbonate rock as two isotopic endmembers, the proportion of soil C02 generated by dissolution of carbonate rock is calculated, about 21%-25% for soil profile developed on limestone basement, 19%-21% for soil profile developed on dolostone basement. There is almost no influx of

  8. Conducting carbonized polyaniline nanotubes

    Science.gov (United States)

    Mentus, Slavko; Ćirić-Marjanović, Gordana; Trchová, Miroslava; Stejskal, Jaroslav

    2009-06-01

    Conducting nitrogen-containing carbon nanotubes were synthesized by the carbonization of self-assembled polyaniline nanotubes protonated with sulfuric acid. Carbonization was carried out in a nitrogen atmosphere at a heating rate of 10 °C min-1 up to a maximum temperature of 800 °C. The carbonized polyaniline nanotubes which have a typical outer diameter of 100-260 nm, with an inner diameter of 20-170 nm and a length extending from 0.5 to 0.8 µm, accompanied with very thin nanotubes with outer diameters of 8-14 nm, inner diameters 3.0-4.5 nm and length extending from 0.3 to 1.0 µm, were observed by scanning and transmission electron microscopies. Elemental analysis showed 9 wt% of nitrogen in the carbonized product. Conductivity of the nanotubular PANI precursor, amounting to 0.04 S cm-1, increased to 0.7 S cm-1 upon carbonization. Molecular structure of carbonized polyaniline nanotubes has been analyzed by FTIR and Raman spectroscopies, and their paramagnetic characteristics were compared with the starting PANI nanotubes by EPR spectroscopy.

  9. Conducting carbonized polyaniline nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Mentus, Slavko; Ciric-Marjanovic, Gordana [Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12-16, 11158 Belgrade (Serbia); Trchova, Miroslava; Stejskal, Jaroslav [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Square 2, 162 06 Prague 6 (Czech Republic)], E-mail: gordana@ffh.bg.ac.rs

    2009-06-17

    Conducting nitrogen-containing carbon nanotubes were synthesized by the carbonization of self-assembled polyaniline nanotubes protonated with sulfuric acid. Carbonization was carried out in a nitrogen atmosphere at a heating rate of 10 deg. C min{sup -1} up to a maximum temperature of 800 deg. C. The carbonized polyaniline nanotubes which have a typical outer diameter of 100-260 nm, with an inner diameter of 20-170 nm and a length extending from 0.5 to 0.8 {mu}m, accompanied with very thin nanotubes with outer diameters of 8-14 nm, inner diameters 3.0-4.5 nm and length extending from 0.3 to 1.0 {mu}m, were observed by scanning and transmission electron microscopies. Elemental analysis showed 9 wt% of nitrogen in the carbonized product. Conductivity of the nanotubular PANI precursor, amounting to 0.04 S cm{sup -1}, increased to 0.7 S cm{sup -1} upon carbonization. Molecular structure of carbonized polyaniline nanotubes has been analyzed by FTIR and Raman spectroscopies, and their paramagnetic characteristics were compared with the starting PANI nanotubes by EPR spectroscopy.

  10. Small diameter carbon nanopipettes

    Science.gov (United States)

    Singhal, Riju; Bhattacharyya, Sayan; Orynbayeva, Zulfiya; Vitol, Elina; Friedman, Gary; Gogotsi, Yury

    2010-01-01

    Nanoscale multifunctional carbon probes facilitate cellular studies due to their small size, which makes it possible to interrogate organelles within living cells in a minimally invasive fashion. However, connecting nanotubes to macroscopic devices and constructing an integrated system for the purpose of fluid and electrical signal transfer is challenging, as is often the case with nanoscale components. We describe a non-catalytic chemical vapor deposition based method for batch fabrication of integrated multifunctional carbon nanopipettes (CNPs) with tip diameters much smaller (10-30 nm) than previously reported (200 nm and above) and approaching those observed for multiwalled carbon nanotubes. This eliminates the need for complicated attachment/assembly of nanotubes into nanofluidic devices. Variable tip geometries and structures were obtained by controlled deposition of carbon inside and outside quartz pipettes. We have shown that the capillary length and gas flow rate have a marked effect on the carbon deposition. This gives us a flexible protocol, useful for growing carbon layers of different thicknesses at selective locations on a glass pipette to yield a large variety of cellular probes in bulk quantities. The CNPs possess an open channel for fluid transfer with the carbon deposited inside at 875 °C behaving like an amorphous semiconductor. Vacuum annealing of the CNP tips at temperatures up to 2000 °C yields graphitic carbon structures with an increase in conductivity of two orders of magnitude. Penetration of the integrated carbon nanoprobes into cells was shown to produce minimal Ca2+ signals, fast recovery of basal Ca2+ levels and no adverse activation of the cellular metabolism during interrogation times as long as 0.5-1 h.

  11. Small diameter carbon nanopipettes

    International Nuclear Information System (INIS)

    Nanoscale multifunctional carbon probes facilitate cellular studies due to their small size, which makes it possible to interrogate organelles within living cells in a minimally invasive fashion. However, connecting nanotubes to macroscopic devices and constructing an integrated system for the purpose of fluid and electrical signal transfer is challenging, as is often the case with nanoscale components. We describe a non-catalytic chemical vapor deposition based method for batch fabrication of integrated multifunctional carbon nanopipettes (CNPs) with tip diameters much smaller (10-30 nm) than previously reported (200 nm and above) and approaching those observed for multiwalled carbon nanotubes. This eliminates the need for complicated attachment/assembly of nanotubes into nanofluidic devices. Variable tip geometries and structures were obtained by controlled deposition of carbon inside and outside quartz pipettes. We have shown that the capillary length and gas flow rate have a marked effect on the carbon deposition. This gives us a flexible protocol, useful for growing carbon layers of different thicknesses at selective locations on a glass pipette to yield a large variety of cellular probes in bulk quantities. The CNPs possess an open channel for fluid transfer with the carbon deposited inside at 875 deg. C behaving like an amorphous semiconductor. Vacuum annealing of the CNP tips at temperatures up to 2000 deg. C yields graphitic carbon structures with an increase in conductivity of two orders of magnitude. Penetration of the integrated carbon nanoprobes into cells was shown to produce minimal Ca2+ signals, fast recovery of basal Ca2+ levels and no adverse activation of the cellular metabolism during interrogation times as long as 0.5-1 h.

  12. Redesigning Urban Carbon Cycles: from Waste Stream to Commodity

    Science.gov (United States)

    Brabander, D. J.; Fitzstevens, M. G.

    2013-12-01

    While there has been extensive research on the global scale to quantify the fluxes and reservoirs of carbon for predictive climate change models, comparably little attention has been focused on carbon cycles in the built environment. The current management of urban carbon cycles presents a major irony: while cities produce tremendous fluxes of organic carbon waste, their populations are dependent on imported carbon because most urban have limited access to locally sourced carbon. The persistence of outdated management schemes is in part due to the fact that reimagining the handling of urban carbon waste streams requires a transdisciplinary approach. Since the end of the 19th century, U.S. cities have generally relied on the same three options for managing organic carbon waste streams: burn it, bury it, or dilute it. These options still underpin the framework for today's design and management strategies for handling urban carbon waste. We contend that urban carbon management systems for the 21st century need to be scalable, must acknowledge how climate modulates the biogeochemical cycling of urban carbon, and should carefully factor local political and cultural values. Urban waste carbon is a complex matrix ranging from wastewater biosolids to municipal compost. Our first goal in designing targeted and efficient urban carbon management schemes has been examining approaches for categorizing and geochemically fingerprinting these matrices. To date we have used a combination of major and trace element ratio analysis and bulk matrix characteristics, such as pH, density, and loss on ignition, to feed multivariable statistical analysis in order to identify variables that are effective tracers for each waste stream. This approach was initially developed for Boston, MA, US, in the context of identifying components of municipal compost streams that were responsible for increasing the lead inventory in the final product to concentrations that no longer permitted its use in

  13. Carbon Ion Therapy

    DEFF Research Database (Denmark)

    Bassler, Niels; Hansen, David Christoffer; Herrmann, Rochus;

    On the importance of choice of target size for selective boosting of hypoxic tumor subvolumina in carbon ion therapy Purpose: Functional imaging methods in radiotherapy are maturing and can to some extent uncover radio resistant structures found within a tumour entity. Selective boost of identified...... effect. All cell lines investigated here did not reach an OER of 1, even for the smaller structures, which may indicate that the achievable dose average LET of carbon ions is too low, and heavier ions than carbon may be considered for functional LET-painting....

  14. THE SODIUM PREVALENCE IN CARBONATED SOFT DRINKS SOLD IN BRAZIL

    Directory of Open Access Journals (Sweden)

    Sandra Fernanda Nunes

    2012-12-01

    Full Text Available The carbonated soft drinks intake has changed the children eating habits. This factor may be directly associated with arterial hypertension due the high consumption of sodium present in foods and drinks industrialized. This study was to compare sodium levels between two different types of carbonated soft drinks, carbonated sugar drinks and diet drinks to define what type of drink has the lowest sodium content and alerting healthcare professionals about the presence of sodium in industrialized beverages. The study included labels of carbonated soft drinks n = 33 – sugar drinks (n = 21 or diet drinks (n = 12 – of five different flavors.All carbonated soft drinks evaluated have sodium in its composition. However, the sodium presence in carbonated sugar drinks was significantly lower when compared with carbonated diet drinks (69.05 ± 16.55 vs. 145.30 ± 47.36mg Na/l, respectively.Studies to identify children's eating habits related with increased consumption of foods and drinks manufactured are needed to identify, reduce and prevent high blood pressure.

  15. Branchfall dominates annual carbon flux across lowland Amazonian forests

    Science.gov (United States)

    Marvin, David C.; Asner, Gregory P.

    2016-09-01

    Tropical forests play an important role in the global carbon cycle, but knowledge of interannual variation in the total tropical carbon flux and constituent carbon pools is highly uncertain. One such pool, branchfall, is an ecologically important dynamic with links to nutrient cycling, forest productivity, and drought. Identifying and quantifying branchfall over large areas would reveal the role of branchfall in carbon and nutrient cycling. Using data from repeat airborne light detection and ranging campaigns across a wide array of lowland Amazonian forest landscapes totaling nearly 100 000 ha, we find that upper canopy gaps—driven by branchfall—are pervasive features of every landscape studied, and are seven times more frequent than full tree mortality. Moreover, branchfall comprises a major carbon source on a landscape basis, exceeding that of tree mortality by 21%. On a per hectare basis, branchfall and tree mortality result in 0.65 and 0.72 Mg C ha-1 yr-1 gross source of carbon to the atmosphere, respectively. Reducing uncertainties in annual gross rates of tropical forest carbon flux, for example by incorporating large-scale branchfall dynamics, is crucial for effective policies that foster conservation and restoration of tropical forests. Additionally, large-scale branchfall mapping offers ecologists a new dimension of disturbance monitoring and potential new insights into ecosystem structure and function.

  16. Computable General Equilibrium Techniques for Carbon Tax Modeling

    Directory of Open Access Journals (Sweden)

    Al-Amin

    2009-01-01

    Full Text Available Problem statement: Lacking of proper environmental models environmental pollution is now a solemn problem in many developing countries particularly in Malaysia. Some empirical studies of worldwide reveal that imposition of a carbon tax significantly decreases carbon emissions and does not dramatically reduce economic growth. To our knowledge there has not been any research done to simulate the economic impact of emission control policies in Malaysia. Approach: Therefore this study developed an environmental computable general equilibrium model for Malaysia and investigated carbon tax policy responses in the economy applying exogenously different degrees of carbon tax into the model. Three simulations were carried out using a Malaysian social accounting matrix. Results: The carbon tax policy illustrated that a 1.21% reduction of carbon emission reduced the nominal GDP by 0.82% and exports by 2.08%; 2.34% reduction of carbon emission reduced the nominal GDP by 1.90% and exports by 3.97% and 3.40% reduction of carbon emission reduced the nominal GDP by 3.17% and exports by 5.71%. Conclusion/Recommendations: Imposition of successively higher carbon tax results in increased government revenue from baseline by 26.67, 53.07 and 79.28% respectively. However, fixed capital investment increased in scenario 1a by 0.43% and decreased in scenarios 1b and 1c by 0.26 and 1.79% respectively from the baseline. According to our policy findings policy makers should consider 1st (scenario 1a carbon tax policy. This policy results in achieving reasonably good environmental impacts without losing the investment, fixed capital investment, investment share of nominal GDP and government revenue.

  17. Investigations during fiscal 1995 on capability of oceans to absorb and fix carbon dioxide; 1995 nendo kaiyo no nisanka tanso kyushu kotei noryoku no chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Investigations were given on capability of oceans to absorb and fix carbon dioxide as part of measures to prevent global warming. Carbon dioxide absorption and fixation in oceans relate to biological and chemical processes, whereas parameter dependence of each process was investigated. In relation to dissolution and dissociation of carbon dioxide into oceans, the parameter that governs exchange of carbon dioxide between atmosphere and ocean is partial pressure of carbon dioxide in surface sea water. This partial pressure is largely affected by water temperature, total carbonic acid and alkalinity. Particle-shaped organic carbon (detritus) is formed mainly by withering of photoplanktons. Formation of calcium carbonate due to activities of living organisms increases the carbon dioxide partial pressure. Fluxes of detritus are predominant among the whole precipitation flux in carbon circulation, which are more than two times the precipitation flux of photoplanktons. Particles are turned into inorganics by bacteria during the precipitation process. 29 refs., 21 figs., 6 tabs.

  18. Carbon emission and sequestration of urban turfgrass systems in Hong Kong

    International Nuclear Information System (INIS)

    Climate change is more than just a global issue. Locally released carbon dioxide may lead to a rise in global ambient temperature and influence the surrounding climate. Urban greenery may mitigate this as they can remove carbon dioxide by storing carbon in substrates and vegetation. On the other hand, urban greenery systems which are under intense management and maintenance may contribute to the emission of carbon dioxide or other greenhouse gases. The impact of urban greenery on carbon balance in major metropolitan areas thus remains controversial. We investigated the carbon footprints of urban turf operation and maintenance by conducting a research questionnaire on different Hong Kong turfs in 2012, and showed that turf maintenance contributed 0.17 to 0.63 kg Ce m−2 y−1 to carbon emissions. We also determined the carbon storage of turfs at 0.05 to 0.21 kg C m−2 for aboveground grass biomass and 1.26 to 4.89 kg C m−2 for soils (to 15 cm depth). We estimated that the carbon sink capacity of turfs could be offset by carbon emissions in 5–24 years under current management patterns, shifting from carbon sink to carbon source. Our study suggested that maintenance management played a key role in the carbon budget and footprint of urban greeneries. The environmental impact of turfgrass systems can be optimized by shifting away from empirically designed maintenance schedules towards rational ones based on carbon sink and emission principles. - Highlights: • Carbon storage capacity at 0.05 to 0.21 kg C m−2 for grasses and 1.26 to 4.89 kg C m−2 for soils (to 15 cm depth). • Turf maintenance contributed to carbon emissions at 0.17 to 0.63 kg Ce (carbon equivalent) m−2 y−1. • Turf system respiration was negatively correlated with soil carbon capacity but only in the wet season. • Carbon stored in turfs could be offset by maintenance carbon emissions in 5–24 years

  19. Carbon emission and sequestration of urban turfgrass systems in Hong Kong

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Ling [School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong (China); Shi, Zhengjun [Shenzhen Key Laboratory of Southern Subtropical Plant Diversity, Fairy Lake Botanical Garden, Shenzhen and Chinese Academy of Science, Shenzhen (China); Chu, L.M., E-mail: leemanchu@cuhk.edu.hk [School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong (China)

    2014-03-01

    Climate change is more than just a global issue. Locally released carbon dioxide may lead to a rise in global ambient temperature and influence the surrounding climate. Urban greenery may mitigate this as they can remove carbon dioxide by storing carbon in substrates and vegetation. On the other hand, urban greenery systems which are under intense management and maintenance may contribute to the emission of carbon dioxide or other greenhouse gases. The impact of urban greenery on carbon balance in major metropolitan areas thus remains controversial. We investigated the carbon footprints of urban turf operation and maintenance by conducting a research questionnaire on different Hong Kong turfs in 2012, and showed that turf maintenance contributed 0.17 to 0.63 kg Ce m{sup −2} y{sup −1} to carbon emissions. We also determined the carbon storage of turfs at 0.05 to 0.21 kg C m{sup −2} for aboveground grass biomass and 1.26 to 4.89 kg C m{sup −2} for soils (to 15 cm depth). We estimated that the carbon sink capacity of turfs could be offset by carbon emissions in 5–24 years under current management patterns, shifting from carbon sink to carbon source. Our study suggested that maintenance management played a key role in the carbon budget and footprint of urban greeneries. The environmental impact of turfgrass systems can be optimized by shifting away from empirically designed maintenance schedules towards rational ones based on carbon sink and emission principles. - Highlights: • Carbon storage capacity at 0.05 to 0.21 kg C m{sup −2} for grasses and 1.26 to 4.89 kg C m{sup −2} for soils (to 15 cm depth). • Turf maintenance contributed to carbon emissions at 0.17 to 0.63 kg Ce (carbon equivalent) m{sup −2} y{sup −1}. • Turf system respiration was negatively correlated with soil carbon capacity but only in the wet season. • Carbon stored in turfs could be offset by maintenance carbon emissions in 5–24 years.

  20. DISCOVERY AND ANALYSIS OF 21 μm FEATURE SOURCES IN THE MAGELLANIC CLOUDS

    International Nuclear Information System (INIS)

    Spitzer Space Telescope mid-infrared spectroscopy has been obtained for 15 carbon-rich protoplanetary nebulae (PPNe) in the Large Magellanic Cloud (LMC) and for two other such stars in the Small Magellanic Cloud (SMC). Of these 17 PPNe, the unidentified 21 μm feature is strong in 7 spectra, weak in 2 spectra, and very weak or questionable in 4 spectra. Two of the four spectra without the 21 μm feature have a very strong feature near 11 μm, similar to a feature observed in some carbon-rich planetary nebulae (PNe) in the LMC. We attribute this feature to unusual SiC dust, although the feature-to-continuum ratio is much larger than for SiC features in Galactic or Magellanic Cloud carbon star spectra. The remaining two objects show typical carbon-rich PPNe spectra with no 21 μm features. One of the LMC objects that lacks the 21 μm feature and one SMC object with a questionable 21 μm detection may have mixed dust chemistries based upon their spectral similarity to Galactic [WC] PNe. The 13 objects that either definitely or may show the 21 μm feature have distinct dust shell properties compared to the Galactic 21 μm objects-the 21 μm features are weaker, the estimated dust temperatures are significantly higher, the unidentified infrared (UIR) bands are stronger, and the UIRs show more structure. Four of the 21 μm objects appear to show normal SiC emission features in their spectra. Many of the PPNe show strong 30 μm features, although this feature carries less of the total mid-infrared emission than is normally the case for the Galactic 21 μm PPNe. The LMC objects are in the LMC halo rather than in the LMC bar. The estimated luminosities of these PPNe vary from 4700 to 12,500 Lsun.

  1. 46 CFR 151.50-41 - Carbon disulfide (carbon bisulfide).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Carbon disulfide (carbon bisulfide). 151.50-41 Section... CARGOES BARGES CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-41 Carbon disulfide (carbon bisulfide). (a) All openings shall be in the top of the tank. (b) Loading lines...

  2. Synthesis and characterization of boron-doped carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Ceragioli, H J; Peterlevitz, A C; Quispe, J C R; Pasquetto, M P; Sampaio, M A; Baranauskas, V [Faculdade de Engenharia Eletrica e Computacao, Departamento de Semicondutores, Instrumentos e Fotonica, Universidade Estadual de Campinas, UNICAMP, Av. Albert Einstein N.400, 13083-852 Campinas SP Brasil (Brazil); Larena, A [Department of Chemical Industrial Engineering and Environment, Universidad Politecnica de Madrid, E.T.S. Ingenieros Industriales, C/ Jose Gutierrez Abascal, Madrid (Spain)], E-mail: vitor.baranauskas@gmail.com

    2008-03-15

    Boron-doped carbon nanotubes have been prepared by chemical vapour deposition of ethyl alcohol doped with B{sub 2}O{sub 3} using a hot-filament system. Multi-wall carbon nanotubes of diameters in the range of 30-100 nm have been observed by field emission scanning electron microscopy (FESEM). Raman measurements indicated that the degree of C-C sp{sup 2} order decreased with boron doping. Lowest threshold fields achieved were 1.0 V/{mu}m and 2.1 V/{mu}m for undoped and boron-doped samples, respectively.

  3. New strategies for the selective functionalization of carbon materials

    Directory of Open Access Journals (Sweden)

    M. Pérez-Mendoza

    2012-03-01

    Full Text Available Selectively surface-modified solids can play a crucialrole in the development of new materials devised togive effective answers to the new technologydemands of the more sustainable 21st-centuryindustry. This has brought about a concentration ofresearch efforts on the elaboration of specificchemical functionality on solid surfaces. Nevertheless,the introduction of specific surface functionalizationon carbon materials has not yet realized the degreeof sophistication and control that other solid materialshave reached. This article reviews the latest researchdeveloped under the CARB-NANOMETAL project(at the Universities of Granada and Jaén towardsthe designing of new strategies for the selectivefunctionalization of carbon materials.

  4. Agenda 21 haridusprogramm / Imbi Henno

    Index Scriptorium Estoniae

    Henno, Imbi

    2000-01-01

    1992. a Rio de Janeiros toimunud ÜRO keskkonna- ja arengukonverentsil võeti vastu "Agenda 21", määrab kindlaks riikide säästva arengu alased põhisuunad käesoleval sajandil. 1997. a. Rio jätkukonverentsil tegi ÜRO Säästva Arengu Komisjon valitsustele ettekirjutuse - viia ellu "Agenda 21" põhimõtted. ÜRO Säästva Arengu Komisjoni eestvõtmisel võeti 1998. a. vastu ka "Agenda 21" 36. peatüki "Haridus, koolitus ja avalikkuse teadlikkus" laiendatud versioon, mille eesmärk on edendada riikidevahelist koostööd ja säästva arengu alast teadlikkust

  5. Carbon Stock and Carbon Cycle of Wetland Ecosystem

    Institute of Scientific and Technical Information of China (English)

    Zhangquan; ZENG; Canming; ZHANG; Jiao; LI; Nan; YANG; Xihao; LI; Yandong; NIU; Zijian; WU

    2014-01-01

    Wetland ecosystem is an essential ecosystem in the world. Its organic carbon stock and carbon cycle are important basis of global carbon cycle researches and also major contents of global climate change researches. Researches have shown that wetland protection and restoration can promote carbon accumulation and reduce emission of greenhouse gases. This paper discussed influence of carbon stock and carbon balance of wetland ecosystem and emission of greenhouse gases,as well as the relationship between wetland and global climate changes. Finally,it made prospect on researches about carbon cycle of Dongting Lake.

  6. A novel carbon fiber based porous carbon monolith

    Energy Technology Data Exchange (ETDEWEB)

    Burchell, T.D.; Klett, J.W.; Weaver, C.E.

    1995-06-01

    A novel porous carbon material based on carbon fibers has been developed. The material, when activated, develops a significant micro- or mesopore volume dependent upon the carbon fiber type utilized (isotropic pitch or polyacrylonitrile). The materials will find applications in the field of fluid separations or as a catalyst support. Here, the manufacture and characterization of our porous carbon monoliths are described. A novel adsorbent carbon composite material has been developed comprising carbon fibers and a binder. The material, called carbon fiber composite molecular sieve (CFCMS), was developed through a joint research program between Oak Ridge National Laboratory (ORNL) and the University of Kentucky, Center for Applied Energy Research (UKCAER).

  7. Authigenic Carbonate and the History of the Global Carbon Cycle

    Science.gov (United States)

    Schrag, Daniel P.; Higgins, John. A.; Macdonald, Francis A.; Johnston, David T.

    2013-02-01

    We present a framework for interpreting the carbon isotopic composition of sedimentary rocks, which in turn requires a fundamental reinterpretation of the carbon cycle and redox budgets over Earth's history. We propose that authigenic carbonate, produced in sediment pore fluids during early diagenesis, has played a major role in the carbon cycle in the past. This sink constitutes a minor component of the carbon isotope mass balance under the modern, high levels of atmospheric oxygen but was much larger in times of low atmospheric O2 or widespread marine anoxia. Waxing and waning of a global authigenic carbonate sink helps to explain extreme carbon isotope variations in the Proterozoic, Paleozoic, and Triassic.

  8. High performance carbon-carbon composites

    Indian Academy of Sciences (India)

    Lalit M Manocha

    2003-02-01

    Carbon-carbon composites rank first among ceramic composite materials with a spectrum of properties and applications in various sectors. These composites are made of fibres in various directions and carbonaceous polymers and hydrocarbons as matrix precursors. Their density and properties depend on the type and volume fraction of reinforcement, matrix precursor used and end heat treatment temperature. Composites made with thermosetting resins as matrix precursors possess low densities (1.55–1.75 g/cm3) and well-distributed microporosity whereas those made with pitch as the matrix precursor, after densification exhibit densities of 1.8–2.0 g/cm3 with some mesopores, and those made by the CVD technique with hydrocarbon gases, possess intermediate densities and matrices with close porosities. The former (resin-based) composites exhibit high flexural strength, low toughness and low thermal conductivity, whereas the latter (pitch- and CVD-based) can be made with very high thermal conductivity (400–700 W/MK) in the fibre direction. Carbon-carbon composites are used in a variety of sectors requiring high mechanical properties at elevated temperatures, good frictional properties for brake pads in high speed vehicles or high thermal conductivity for thermal management applications. However, for extended life applications, these composites need to be protected against oxidation either through matrix modification with Si, Zr, Hf etc. or by multilayer oxidation protection coatings consisting of SiC, silica, zircon etc.

  9. Carbon aerogels; Les aerogels de carbone

    Energy Technology Data Exchange (ETDEWEB)

    Berthon-Fabry, S.; Achard, P

    2003-06-15

    The carbon aerogel is a nano-porous material at open porosity, electrical conductor. The aerogels morphology is variable in function of the different synthesis parameters. This characteristic offers to the aerogels a better adaptability to many applications: electrodes (super condensers, fuel cells). The author presents the materials elaboration and their applications. It provides also the research programs: fundamental research, realization of super-condenser electrodes, fuel cells electrodes, gas storage materials and opaque materials for thermal insulation. (A.L.B.)

  10. Global Tree Cover and Biomass Carbon on Agricultural Land: The contribution of agroforestry to global and national carbon budgets.

    Science.gov (United States)

    Zomer, Robert J; Neufeldt, Henry; Xu, Jianchu; Ahrends, Antje; Bossio, Deborah; Trabucco, Antonio; van Noordwijk, Meine; Wang, Mingcheng

    2016-01-01

    Agroforestry systems and tree cover on agricultural land make an important contribution to climate change mitigation, but are not systematically accounted for in either global carbon budgets or national carbon accounting. This paper assesses the role of trees on agricultural land and their significance for carbon sequestration at a global level, along with recent change trends. Remote sensing data show that in 2010, 43% of all agricultural land globally had at least 10% tree cover and that this has increased by 2% over the previous ten years. Combining geographically and bioclimatically stratified Intergovernmental Panel on Climate Change (IPCC) Tier 1 default estimates of carbon storage with this tree cover analysis, we estimated 45.3 PgC on agricultural land globally, with trees contributing >75%. Between 2000 and 2010 tree cover increased by 3.7%, resulting in an increase of >2 PgC (or 4.6%) of biomass carbon. On average, globally, biomass carbon increased from 20.4 to 21.4 tC ha(-1). Regional and country-level variation in stocks and trends were mapped and tabulated globally, and for all countries. Brazil, Indonesia, China and India had the largest increases in biomass carbon stored on agricultural land, while Argentina, Myanmar, and Sierra Leone had the largest decreases. PMID:27435095

  11. Global Tree Cover and Biomass Carbon on Agricultural Land: The contribution of agroforestry to global and national carbon budgets

    Science.gov (United States)

    Zomer, Robert J.; Neufeldt, Henry; Xu, Jianchu; Ahrends, Antje; Bossio, Deborah; Trabucco, Antonio; van Noordwijk, Meine; Wang, Mingcheng

    2016-07-01

    Agroforestry systems and tree cover on agricultural land make an important contribution to climate change mitigation, but are not systematically accounted for in either global carbon budgets or national carbon accounting. This paper assesses the role of trees on agricultural land and their significance for carbon sequestration at a global level, along with recent change trends. Remote sensing data show that in 2010, 43% of all agricultural land globally had at least 10% tree cover and that this has increased by 2% over the previous ten years. Combining geographically and bioclimatically stratified Intergovernmental Panel on Climate Change (IPCC) Tier 1 default estimates of carbon storage with this tree cover analysis, we estimated 45.3 PgC on agricultural land globally, with trees contributing >75%. Between 2000 and 2010 tree cover increased by 3.7%, resulting in an increase of >2 PgC (or 4.6%) of biomass carbon. On average, globally, biomass carbon increased from 20.4 to 21.4 tC ha‑1. Regional and country-level variation in stocks and trends were mapped and tabulated globally, and for all countries. Brazil, Indonesia, China and India had the largest increases in biomass carbon stored on agricultural land, while Argentina, Myanmar, and Sierra Leone had the largest decreases.

  12. Global Tree Cover and Biomass Carbon on Agricultural Land: The contribution of agroforestry to global and national carbon budgets

    Science.gov (United States)

    Zomer, Robert J.; Neufeldt, Henry; Xu, Jianchu; Ahrends, Antje; Bossio, Deborah; Trabucco, Antonio; van Noordwijk, Meine; Wang, Mingcheng

    2016-07-01

    Agroforestry systems and tree cover on agricultural land make an important contribution to climate change mitigation, but are not systematically accounted for in either global carbon budgets or national carbon accounting. This paper assesses the role of trees on agricultural land and their significance for carbon sequestration at a global level, along with recent change trends. Remote sensing data show that in 2010, 43% of all agricultural land globally had at least 10% tree cover and that this has increased by 2% over the previous ten years. Combining geographically and bioclimatically stratified Intergovernmental Panel on Climate Change (IPCC) Tier 1 default estimates of carbon storage with this tree cover analysis, we estimated 45.3 PgC on agricultural land globally, with trees contributing >75%. Between 2000 and 2010 tree cover increased by 3.7%, resulting in an increase of >2 PgC (or 4.6%) of biomass carbon. On average, globally, biomass carbon increased from 20.4 to 21.4 tC ha-1. Regional and country-level variation in stocks and trends were mapped and tabulated globally, and for all countries. Brazil, Indonesia, China and India had the largest increases in biomass carbon stored on agricultural land, while Argentina, Myanmar, and Sierra Leone had the largest decreases.

  13. Global Tree Cover and Biomass Carbon on Agricultural Land: The contribution of agroforestry to global and national carbon budgets

    Science.gov (United States)

    Zomer, Robert J.; Neufeldt, Henry; Xu, Jianchu; Ahrends, Antje; Bossio, Deborah; Trabucco, Antonio; van Noordwijk, Meine; Wang, Mingcheng

    2016-01-01

    Agroforestry systems and tree cover on agricultural land make an important contribution to climate change mitigation, but are not systematically accounted for in either global carbon budgets or national carbon accounting. This paper assesses the role of trees on agricultural land and their significance for carbon sequestration at a global level, along with recent change trends. Remote sensing data show that in 2010, 43% of all agricultural land globally had at least 10% tree cover and that this has increased by 2% over the previous ten years. Combining geographically and bioclimatically stratified Intergovernmental Panel on Climate Change (IPCC) Tier 1 default estimates of carbon storage with this tree cover analysis, we estimated 45.3 PgC on agricultural land globally, with trees contributing >75%. Between 2000 and 2010 tree cover increased by 3.7%, resulting in an increase of >2 PgC (or 4.6%) of biomass carbon. On average, globally, biomass carbon increased from 20.4 to 21.4 tC ha−1. Regional and country-level variation in stocks and trends were mapped and tabulated globally, and for all countries. Brazil, Indonesia, China and India had the largest increases in biomass carbon stored on agricultural land, while Argentina, Myanmar, and Sierra Leone had the largest decreases. PMID:27435095

  14. Sodium carbonate poisoning

    Science.gov (United States)

    Sodium carbonate is found in: Automatic dishwashing soaps Clinitest (diabetes testing) tablets Glass products Pulp and paper products Some bleaches Some bubble bath solutions Some steam iron cleaners Note: This list is not all-inclusive.

  15. Carbon monoxide poisoning

    Science.gov (United States)

    ... heater). Many carbon monoxide poisonings occur in the winter months when furnaces, gas fireplaces, and portable heaters ... 16567227 www.ncbi.nlm.nih.gov/pubmed/16567227 . Nelson LS, Hoffman RS. Inhaled toxins. In: Marx JA, ...

  16. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... United States die every year from accidental non-fire related CO poisoning. Products that can produce deadly ... Driven Generators, 2004-2014 January 07, 2016 Non-Fire Carbon Monoxide Deaths Associated with the Use of ...

  17. FLUIDIZATION OF CARBON NANOTUBES

    Institute of Scientific and Technical Information of China (English)

    Fei Wei; Cang Huang; Yao Wang

    2005-01-01

    Carbon nanotubes (CNTs) can be fluidized in the form of fluidlike agglomerates made of many three-dimensional sub-agglomerates, having a multi-stage agglomerate (MSA) structure and containing large amounts of twisting CNTs of micrometer magnitude.

  18. Carbon nanotubes: Fibrillar pharmacology

    Science.gov (United States)

    Kostarelos, Kostas

    2010-10-01

    The mechanisms by which chemically functionalized carbon nanotubes flow in blood and are excreted through the kidneys illustrate the unconventional behaviour of these fibrillar nanostructures, and the opportunities they offer as components for the design of advanced delivery vehicles.

  19. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Safety More CO Blogs Research & Statistics March 09, 2016 Supplemental Memos Regarding Some of the Hazards Associated with Engine-Driven Generators, 2004-2014 January 07, 2016 Non-Fire Carbon Monoxide Deaths Associated with the ...

  20. The Carbon Emission Game

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    When Chinese President Hu Jintao attended the UN climate summit on September22,he made a solemn commitment that China will cut its per GDP unit carbon emission to a significant amount in 2020 compared with that of 2005.

  1. Total Ecosystem Carbon Stock

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Total ecosystem carbon includes above- and below-ground live plant components (such as leaf, branch, stem and root), dead biomass (such as standing dead wood, down...

  2. Carbon monoxide intoxication

    Energy Technology Data Exchange (ETDEWEB)

    Kales, S.N. (Cambridge Hospital, MA (United States))

    1993-11-01

    Carbon monoxide poisoning usually results from inhalation of exhaust fumes from motor vehicles, smoke from fires or fumes from faulty heating systems. Carbon monoxide has a high affinity for hemoglobin, with which it forms carboxyhemoglobin. The resulting decrease in both oxygen-carrying capacity and oxygen release can lead to end-organ hypoxia. The clinical presentation is nonspecific. Headache, dizziness, fatigue and nausea are common in mild to moderate carbon monoxide poisoning. In more severe cases, tachycardia, tachypnea and central nervous system depression occur. When carbon monoxide intoxication is suspected, empiric treatment with 100 percent oxygen should be initiated immediately. The diagnosis is confirmed by documenting an elevated carboxyhemoglobin level. Hyperbaric oxygen therapy is recommended in patients with neurologic dysfunction, cardiac dysfunction or a history of unconsciousness. 26 refs.

  3. Carbon partitioning in photosynthesis.

    Science.gov (United States)

    Melis, Anastasios

    2013-06-01

    The work seeks to raise awareness of a fundamental problem that impacts the renewable generation of fuels and chemicals via (photo)synthetic biology. At issue is regulation of the endogenous cellular carbon partitioning between different biosynthetic pathways, over which the living cell exerts stringent control. The regulation of carbon partitioning in photosynthesis is not understood. In plants, microalgae and cyanobacteria, methods need be devised to alter photosynthetic carbon partitioning between the sugar, terpenoid, and fatty acid biosynthetic pathways, to lower the prevalence of sugar biosynthesis and correspondingly upregulate terpenoid and fatty acid hydrocarbons production in the cell. Insight from unusual but naturally occurring carbon-partitioning processes can help in the design of blueprints for improved photosynthetic fuels and chemicals production.

  4. Carbon isotopic record from Upper Devonian carbonates at Dongcun in Guilin, southern China, supporting the world-wide pattern of carbon isotope excursions during Frasnian-Famennian transition

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Two positive δ13C excursions are presented in records from the Frasnian-Famennian (F-F) marine carbonate sediments in Europe, America, Africa, and Australia, having been considered as a worldwide pattern, and attributed to enhanced organic carbon burial during the F-F biological mass extinction. However, this worldwide pattern has not been revealed from the well-deposited Late Devonian sequences in southern China. In this paper, a detailed investigation has been made on the Late Devonian section at Dongcun, Guilin, southern China to constrain perturbations in δ13C of carbonates in the F-F deposited sequence. The result from this section also indicates two positive δ13C excursions during the F-F transition. The first excursion with an amplitude of 1.5‰ occurred at the bottom of linguiformis Zone, later than the early excursion existing in the Late rhenana Zone of the Late Devonian profiles in other continents, especially, in central Europe. This difference has been expected to be a result as conodont Palmatolepis linguiformis occurred earlier in southern China than other sites. The second excursion with an amplitude of 2.1‰ is located at the F-F boundary, same as the records from other continents. This result strongly supports the view that two carbon isotope positive excursions during the F-F transition are common in carbonate sediments, resulting from worldwide increases of organic carbon burial intensity.

  5. 27 CFR 21.97 - Benzene.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Benzene. 21.97 Section 21... TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.97 Benzene. (a..., Standard No. D 836-77; for incorporation by reference, see § 21.6(b).) When 100 ml of benzene are...

  6. 28 CFR 21.3 - Aliens.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Aliens. 21.3 Section 21.3 Judicial Administration DEPARTMENT OF JUSTICE WITNESS FEES § 21.3 Aliens. (a) Aliens entitled to payment of $30 per day. The following aliens are entitled to witness fees and allowances provided in § 21.4: (1)...

  7. 38 CFR 21.7170 - Course measurement.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Course measurement. 21... Bill-Active Duty) Course Assessment § 21.7170 Course measurement. In administering benefits payable...)—Measurement of courses; (b) § 21.4272—Collegiate course measurement; (c) § 21.4273—Collegiate graduate;...

  8. Carbon and oxygen isotope microanalysis of carbonate.

    Science.gov (United States)

    Velivetskaya, Tatiana A; Ignatiev, Alexander V; Gorbarenko, Sergey A

    2009-08-30

    Technical modification of the conventional method for the delta(13)C and delta(18)O analysis of 10-30 microg carbonate samples is described. The CO(2) extraction is carried out in vacuum using 105% phosphoric acid at 95 degrees C, and the isotopic composition of CO(2) is measured in a helium flow by gas chromatography/isotope ratio mass spectrometry (GC/IRMS). The feed-motion of samples to the reaction vessel provides sequential dropping of only the samples (without the sample holder) into the acid, preventing the contamination of acid and allowing us to use the same acid to carry out very large numbers of analyses. The high accuracy and high reproducibility of the delta(13)C and delta(18)O analyses were demonstrated by measurements of international standards and comparison of results obtained by our method and by the conventional method. Our method allows us to analyze 10 microg of the carbonate with a standard deviation of +/-0.05 per thousand for delta(13)C and delta(18)O. The method has been used successfully for the analyses of the oxygen and carbon isotopic composition of the planktonic and benthic foraminifera in detailed palaeotemperature reconstructions of the Okhotsk Sea. PMID:19603476

  9. Impacts of urbanization on carbon balance in terrestrial ecosystems of the Southern United States

    International Nuclear Information System (INIS)

    Using a process-based Dynamic Land Ecosystem Model, we assessed carbon dynamics of urbanized/developed lands in the Southern United States during 1945–2007. The results indicated that approximately 1.72 (1.69–1.77) Pg (1P = 1015) carbon was stored in urban/developed lands, comparable to the storage of shrubland or cropland in the region. Urbanization resulted in a release of 0.21 Pg carbon to the atmosphere during 1945–2007. Pre-urbanization vegetation type and time since land conversion were two primary factors determining the extent of urbanization impacts on carbon dynamics. After a rapid decline of carbon storage during land conversion, an urban ecosystem gradually accumulates carbon and may compensate for the initial carbon loss in 70–100 years. The carbon sequestration rate of urban ecosystem diminishes with time, nearly disappearing in two centuries after land conversion. This study implied that it is important to take urbanization effect into account for assessing regional carbon balance. - Highlights: ► A series of spatial and temporal urban/developed land maps were generated. ► Urbanization effects on regional carbon dynamics were studied with a process-based Dynamic Land Ecosystem Model (DLEM). ► Carbon storage of urban/developed land was comparable to that stored in cropland and shrubland in the Southern United States. ► Pre-urbanization vegetation type and time since land conversion were two primary factors determining the extent of urbanization impacts on carbon dynamics. ► Urbanization resulted in carbon emission, but established urban areas may gradually accumulate carbon over time. - Urbanization has resulted in carbon release to the atmosphere, but established urban areas may gradually accumulate carbon over time.

  10. Nucleares y la COP 21

    OpenAIRE

    Ortega, Jordi

    2015-01-01

    La COP21 de Paris combina top-down (compromisos de seguimiento y verificación) y bottom-up, (contenidos en las INDC). ¿La energía nuclear formar parte estas contribuciones o Intended Nationally Determined Contributions (INDC)? La diferencia más relevante entre la COP21 y la COP15, entre la cumbre de Paris y de Copenhague, es que hoy se ha superado los acuerdos basados en una “distribución justa de las cargas” (burden sharing). En la COP20 de Lima se hizo un llamamiento en favor...

  11. States and carbon

    International Nuclear Information System (INIS)

    The climate challenge appeals to an unprecedented mutation of our societies. From north to south, all our life styles will have to be changed from dwelling, to transport and feeding. These changes will have sense only at a worldwide scale and will impact our way of development. How can we reduce our energy consumption and greenhouse impact with answering everyone's essential needs at the same time? How can we invent a carbon-free economy in the North and preserve the big socio-economical equilibria at the same time? How can we get rid of poverty in the South without compromising the well-being of the future generations with an increase of CO2 emissions? Such difficulties cannot be overcome without innovations in terms of public policies. This book takes stock of the new possible instruments and policies at the global scale and involving fiscality, standards, investments and social justice. Content: 1 - the carbon threat: a changing climate and energies becoming scarce (the climate threat, an increasing energy insecurity); carbon and modern economy (human greenhouse gas emissions, a carbon-free well-being); governments and carbon control (a global challenge requiring an international control, the experiments era from Rio to the present day, the challenge of the state in front of the carbon threat); 2 - the political instruments of environment: standards as first instruments of climate public policies (standards efficiency in some sectors, standards limitations, standards and innovation); emissions quotas and market instruments (Kyoto protocol and CO2 market, the future of 'cap and trade' and of individual and regional quotas); carbon tax, fiscal instruments and new regulations (carbon tax as an alternative or a complement, other fiscal and para-fiscal instruments, new regulation instruments); investing in climate (managing the transition, governments as transition administrators). (J.S)

  12. Carbon based prosthetic devices

    Energy Technology Data Exchange (ETDEWEB)

    Devlin, D.J.; Carroll, D.W.; Barbero, R.S.; Archuleta, T. [Los Alamos National Lab., NM (US); Klawitter, J.J.; Ogilvie, W.; Strzepa, P. [Ascension Orthopedics (US); Cook, S.D. [Tulane Univ., New Orleans, LA (US). School of Medicine

    1998-12-31

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project objective was to evaluate the use of carbon/carbon-fiber-reinforced composites for use in endoprosthetic devices. The application of these materials for the metacarpophalangeal (MP) joints of the hand was investigated. Issues concerning mechanical properties, bone fixation, biocompatibility, and wear are discussed. A system consisting of fiber reinforced materials with a pyrolytic carbon matrix and diamond-like, carbon-coated wear surfaces was developed. Processes were developed for the chemical vapor infiltration (CVI) of pyrolytic carbon into porous fiber preforms with the ability to tailor the outer porosity of the device to provide a surface for bone in-growth. A method for coating diamond-like carbon (DLC) on the articulating surface by plasma-assisted chemical vapor deposition (CVD) was developed. Preliminary results on mechanical properties of the composite system are discussed and initial biocompatibility studies were performed.

  13. Black carbon in marine sediments

    NARCIS (Netherlands)

    Middelburg, J.J.; Nieuwenhuize, J.; Van Breugel, P.

    1999-01-01

    Concentrations of black carbon were determined for a number of marine sediments. A comparison of black carbon based on thermal oxidation and hot concentrated nitric acid pretreatments revealed that the latter significantly overestimates combustion derived carbon phases. Black carbon accounts for abo

  14. Nano-Carbons as Theranostics

    Directory of Open Access Journals (Sweden)

    Zhuang Liu, Xing-Jie Liang

    2012-01-01

    Full Text Available Nano-carbons, including fullerenes, carbon nanoparticles, carbon nanotubes, graphene, and nano-diamonds, are an important class of nanostructures attracting tremendous interests in the past two decades. In this special issue, seven review articles and research reports are collected, to summarize and present the latest progress in the exploration of various nano-carbons for theranostic applications.

  15. Method for synthesizing carbon nanotubes

    Science.gov (United States)

    Fan, Hongyou

    2012-09-04

    A method for preparing a precursor solution for synthesis of carbon nanomaterials, where a polar solvent is added to at least one block copolymer and at least one carbohydrate compound, and the precursor solution is processed using a self-assembly process and subsequent heating to form nanoporous carbon films, porous carbon nanotubes, and porous carbon nanoparticles.

  16. Carbon isotope effects in carbonate systems

    Science.gov (United States)

    Deines, Peter

    2004-06-01

    Global carbon cycle models require a complete understanding of the δ 13C variability of the Earth's C reservoirs as well as the C isotope effects in the transfer of the element among them. An assessment of δ 13C changes during CO 2 loss from degassing magmas requires knowledge of the melt-CO 2 carbon isotope fractionation. In order to examine the potential size of this effect for silicate melts of varying composition, 13C reduced partition functions were computed in the temperature range 275 to 4000 K for carbonates of varying bond strengths (Mg, Fe, Mn, Sr, Ba, Pb, Zn, Cd, Li, and Na) and the polymorphs of calcite. For a given cation and a given pressure the 13C content increases with the density of the carbonate structure. For a given structure the tendency to concentrate 13C increases with pressure. The effect of pressure (‰/10 kbar) on the size of the reduced partition function of aragonite varies with temperature; in the pressure range 1 to 10 5 bars the change is given by: Δ 13C p average=-0.01796+0.06635∗ 10 3/T+0.006875∗ 10 6/T2 For calcite III the pressure effect is on average 1.4× larger than that for aragonite at all temperatures. The nature of the cation in a given structure type has a significant effect on the carbon isotope fractionation properties. The tendency to concentrate 13C declines in the series magnesite, aragonite, dolomite, strontianite, siderite, calcite, smithonite, witherite, rhodochrosite, otavite, cerrusite. For divalent cations a general expression for an estimation of the reduced partition function (β) from the reduced mass (μ = [M Cation × M Carbonate]/[M Cation + M Carbonate]) is: 1000 lnβ=(0.032367-0.072563∗ 10 3/T-0.01073∗ 10 6/T2)∗μ-14.003+29.953∗ 10 3/T+9.4610∗ 10 6/T2 For Mg-calcite the 13C content varies with the Mg concentration. The fractionation between Mg-calcite (X = mole fraction of MgCO 3) and calcite is given by: 1000 ln(α MgCalite- Calcite)=[0.013702-0.10957× 10 3/T+1.35940× 10 6/T2

  17. Biofuel intercropping effects on soil carbon and microbial activity.

    Science.gov (United States)

    Strickland, Michael S; Leggett, Zakiya H; Sucre, Eric B; Bradford, Mark A

    2015-01-01

    Biofuels will help meet rising demands for energy and, ideally, limit climate change associated with carbon losses from the biosphere to atmosphere. Biofuel management must therefore maximize energy production and maintain ecosystem carbon stocks. Increasingly, there is interest in intercropping biofuels with other crops, partly because biofuel production on arable land might reduce availability and increase the price of food. One intercropping approach involves growing biofuel grasses in forest plantations. Grasses differ from trees in both their organic inputs to soils and microbial associations. These differences are associated with losses of soil carbon when grasses become abundant in forests. We investigated how intercropping switchgrass (Panicum virgalum), a major candidate for cellulosic biomass production, in loblolly pine (Pinus taeda) plantations affects soil carbon, nitrogen, and microbial dynamics. Our design involved four treatments: two pine management regimes where harvest residues (i.e., biomass) were left in place or removed, and two switchgrass regimes where the grass was grown with pine under the same two biomass scenarios (left or removed). Soil variables were measured in four 1-ha replicate plots in the first and second year following switchgrass planting. Under switchgrass intercropping, pools of mineralizable and particulate organic matter carbon were 42% and 33% lower, respectively. These declines translated into a 21% decrease in total soil carbon in the upper 15 cm of the soil profile, during early stand development. The switchgrass effect, however, was isolated to the interbed region where switchgrass is planted. In these regions, switchgrass-induced reductions in soil carbon pools with 29%, 43%, and 24% declines in mineralizable, particulate, and total soil carbon, respectively. Our results support the idea that grass inputs to forests can prime the activity of soil organic carbon degrading microbes, leading to net reductions in stocks

  18. Biofuel intercropping effects on soil carbon and microbial activity.

    Science.gov (United States)

    Strickland, Michael S; Leggett, Zakiya H; Sucre, Eric B; Bradford, Mark A

    2015-01-01

    Biofuels will help meet rising demands for energy and, ideally, limit climate change associated with carbon losses from the biosphere to atmosphere. Biofuel management must therefore maximize energy production and maintain ecosystem carbon stocks. Increasingly, there is interest in intercropping biofuels with other crops, partly because biofuel production on arable land might reduce availability and increase the price of food. One intercropping approach involves growing biofuel grasses in forest plantations. Grasses differ from trees in both their organic inputs to soils and microbial associations. These differences are associated with losses of soil carbon when grasses become abundant in forests. We investigated how intercropping switchgrass (Panicum virgalum), a major candidate for cellulosic biomass production, in loblolly pine (Pinus taeda) plantations affects soil carbon, nitrogen, and microbial dynamics. Our design involved four treatments: two pine management regimes where harvest residues (i.e., biomass) were left in place or removed, and two switchgrass regimes where the grass was grown with pine under the same two biomass scenarios (left or removed). Soil variables were measured in four 1-ha replicate plots in the first and second year following switchgrass planting. Under switchgrass intercropping, pools of mineralizable and particulate organic matter carbon were 42% and 33% lower, respectively. These declines translated into a 21% decrease in total soil carbon in the upper 15 cm of the soil profile, during early stand development. The switchgrass effect, however, was isolated to the interbed region where switchgrass is planted. In these regions, switchgrass-induced reductions in soil carbon pools with 29%, 43%, and 24% declines in mineralizable, particulate, and total soil carbon, respectively. Our results support the idea that grass inputs to forests can prime the activity of soil organic carbon degrading microbes, leading to net reductions in stocks

  19. Mineralogy and stable isotope compositions of carbonate and sulphide minerals of carbonate crusts associated with gas hydrate-forming cold vents from the NE Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Conly, A.G. [Lakehead Univ., Thunder Bay, ON (Canada). Dept. of Geology; Scott, S.D. [Toronto Univ., ON (Canada). Dept. of Geology; Riedel, M. [Natural Resources Canada, Sidney, BC (Canada). Geological Survey of Canada, Pacific Geoscience Centre

    2005-07-01

    In 2001, the ROPOS submersible sampled 21 specimens of carbonate crusts from 2 gas hydrate fields located offshore Vancouver Island on the northeast Pacific continental margin. The mineralogy and stable isotopic composition of carbonate and sulphide minerals were used to evaluate petrogenesis and the relationship to associated gas hydrate occurrences. The crusts form the upper surface of carbonate and pelagic mud mounds within the gas hydrate fields. The crusts are made up of micritic carbonate with a highly variable morphology that includes blocky, fissile, nodular and mudcemented brecciated forms. The crusts include micritic calcite and dolomite/ferroan dolomite, with up to 30 per cent detrital and authigenic silicates. The finely disseminated sulphide minerals include pyrite and trace amounts of sphalerite. Bulk-rock chemical compositions are mainly homogeneous. Any variations reflect the calcite:dolomite and carbonate:silicate ratios. The {delta}13 C values for bulk carbonate (calcite and dolomite) were presented. No definitive correlation between {delta}13 C value and carbonate mineralogy was noted, but calcite-dominant samples were found to be more depleted. The {delta}34 S values for sulphide were also presented. The carbon isotopic composition of the carbonate is associated with the balance of inorganic and organic carbon species. Bacterial sulphate reduction and/or bacterial fermentation and carbonate reduction processes responsible for the production of methane were found to control the {delta}13 C of the carbon dioxide reservoir in gas hydrate environments. It was shown that methane was the carbon source involved in bacterial sulphate reduction and that the isotopic composition of the CO{sub 2} reservoir may be controlled by fractionation during bacterial carbonate reduction. The range in sulphur isotopes correlates with the bacterial sulphate reduction under partially closed conditions, where the rate of diffusion of sulphate is less than the rate of

  20. Biogenic carbon fluxes from global agricultural production and consumption

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Julie; West, Tristram O.; Le Page, Yannick LB; Kyle, G. Page; Zhang, Xuesong; Collatz, George; Imhoff, Marc L.

    2015-10-01

    Quantification of biogenic carbon fluxes from agricultural lands is needed to generate comprehensive bottom-up estimates of net carbon exchange for global and regional carbon monitoring. We estimated global agricultural carbon fluxes associated with annual crop net primary production (NPP), harvested biomass, and consumption of biomass by humans and livestock. These estimates were combined for a single estimate of net carbon exchange (NCE) and spatially distributed to 0.05 degree resolution using MODIS satellite land cover data. Global crop NPP in 2011 was estimated at 5.25 ± 0.46 Pg C yr-1, of which 2.05 ± 0.05 Pg C yr-1 was harvested and 0.54 Pg C yr-1 was collected from crop residues for livestock fodder. Total livestock feed intake in 2011 was 2.42 ± 0.21 Pg C yr-1, of which 2.31 ± 0.21 Pg C yr-1 was emitted as CO2, 0.07 ± 0.01 Pg C yr-1 was emitted as CH4, and 0.04 Pg C yr-1 was contained within milk and egg production. Livestock grazed an estimated 1.27 Pg C yr-1 in 2011, which constituted 52.4% of total feed intake. Global human food intake was 0.57 ± 0.03 Pg C yr-1 in 2011, the majority of which is respired as CO2. Completed global cropland carbon budgets accounted for the ultimate use of ca. 80% of harvested biomass. The spatial distribution of these fluxes may be used for global carbon monitoring, estimation of regional uncertainty, and for use as input to Earth system models.

  1. Aspects of carbon dioxide utilization

    Energy Technology Data Exchange (ETDEWEB)

    Omae, Iwao [Omae Research Laboratories, 335-23 Mizuno, Sayama, Saitama 350-1317 (Japan)

    2006-06-30

    Carbon dioxide reacts with hydrogen, alcohols, acetals, epoxides, amines, carbon-carbon unsaturated compounds, etc. in supercritical carbon dioxide or in other solvents in the presence of metal compounds as catalysts. The products of these reactions are formic acid, formic acid esters, formamides, methanol, dimethyl carbonate, alkylene carbonates, carbamic acid esters, lactones, carboxylic acids, polycarbonate (bisphenol-based engineering polymer), aliphatic polycarbonates, etc. Especially, the productions of formic acid, formic acid methyl ester and dimethylformamide with a ruthenium catalyst; dimethyl carbonate and urethanes with a dialkyltin catalyst; 2-pyrone with a nickel-phosphine catalyst; diphenyl carbonate with a lead phenoxide catalyst; the alternating copolymerization of carbon dioxide and epoxides with a zinc catalyst has attracted attentions as the industrial utilizations of carbon dioxide. The further development of these production processes is expected. (author)

  2. Materiales. Numbers 21-23.

    Science.gov (United States)

    Materiales, 1997

    1997-01-01

    These three journals of contemporary cultural, historical, and social interest contain activities designed to enhance the awareness of students of Spanish as a foreign language regarding the entire panorama of daily life in Spain. Number 21 focuses on the role of modern Spanish women; their career status; female authors; and the changing place of…

  3. Organic modification of carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The organic modification of carbon nanotubes is a novel research field being developed recently. In this article, the history and newest progress of organic modification of carbon nanotubes are reviewed from two aspects:organic covalent modification and organic noncovalent modification of carbon nanotubes. The preparation and properties of organic modified carbon nanotubes are discussed in detail. In addition, the prospective development of organic modification of carbon nanotubes is suggested.

  4. Electrooxidation of DNA at glassy carbon electrodes modified with multiwall carbon nanotubes dispersed in polyethylenimine

    Energy Technology Data Exchange (ETDEWEB)

    Luque, Guillermina L.; Ferreyra, Nancy F. [INFIQC, Departamento de Fisico Quimica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina); Granero, Adrian [INFIQC, Departamento de Fisico Quimica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina); Departamento de Quimica, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Rio Cuarto (Argentina); Bollo, Soledad [Laboratorio de Bioelectroquimica, Facultad de Ciencias Quimicas y Farmaceuticas, Universidad de Chile, P.O. Box 233, Santiago (Chile); Rivas, Gustavo A., E-mail: grivas@fcq.unc.edu.ar [INFIQC, Departamento de Fisico Quimica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina)

    2011-10-30

    This work reports the electrochemical response of the complex between dsDNA and PEI formed in solution and at the surface of glassy carbon electrodes (GCE) modified with a dispersion of multi-walled carbon nanotubes in polyethylenimine (CNT-PEI). Scanning Electron Microscopy and Scanning Electrochemical Microscopy demonstrate that the dispersion covers the whole surface of the electrode although there are areas with higher density of CNT and, consequently, with higher electrochemical reactivity. The adsorption of DNA at GCE/CNT-PEI is fast and it is mainly driven by electrostatic forces. A clear oxidation signal is obtained either for dsDNA or a heterooligonucleotide of 21 bases (oligoY) at potentials smaller than those for the oxidation at bare GCE. The comparison of the behavior of DNA before and after thermal treatment demonstrated that the electrochemical response highly depends on the 3D structure of the nucleic acid.

  5. Mexico and the 21st Century Power Partnership: Paving the Way to a Greener, Smarter, More Flexible Grid

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2016-05-01

    The 21st Century Power Partnership's program in Mexico (21CPP Mexico) is one initiative of the Clean Energy Ministerial carried out in cooperation with government and local stakeholders, drawing upon an international community of power system expertise.The overall goal of this program is to support Mexico's power system transformation by accelerating the transition to a reliable, financially robust, and low-carbon system.

  6. South Africa and the 21st Century Power Partnership: Paving the Way to a Clean, Reliable, and Resilient Power System

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2016-05-01

    Established in 2012, the 21CPP South Africa Programme is a global initiative that connects South African stakeholders with an international community
    of expertise. The overall goal of this program is to support South Africa's power system transformation by accelerating the transition to a reliable, financially robust, and low-carbon power system. 21CPP activities focus on achieving positive outcomes for all participants, especially addressing critical questions and challenges facing system planners, regulators, and operators.

  7. Carbon stocks of intact mangroves and carbon emissions arising from their conversion in the Dominican Republic.

    Science.gov (United States)

    Kauffman, J Boone; Heider, Chris; Norfolk, Jennifer; Payton, Frederick

    2014-04-01

    Mangroves are recognized to possess a variety of ecosystem services including high rates of carbon sequestration and storage. Deforestation and conversion of these ecosystems continue to be high and have been predicted to result in significant carbon emissions to the atmosphere. Yet few studies have quantified the carbon stocks or losses associated with conversion of these ecosystems. In this study we quantified the ecosystem carbon stocks of three common mangrove types of the Caribbean as well as those of abandoned shrimp ponds in areas formerly occupied by mangrove-a common land-use conversion of mangroves throughout the world. In the mangroves of the Montecristi Province in Northwest Dominican Republic we found C stocks ranged from 706 to 1131 Mg/ha. The medium-statured mangroves (3-10 m in height) had the highest C stocks while the tall (> 10 m) mangroves had the lowest ecosystem carbon storage. Carbon stocks of the low mangrove (shrub) type (carbon-rich soils as deep as 2 m. Carbon stocks of abandoned shrimp ponds were 95 Mg/ha or approximately 11% that of the mangroves. Using a stock-change approach, the potential emissions from the conversion of mangroves to shrimp ponds ranged from 2244 to 3799 Mg CO2e/ha (CO2 equivalents). This is among the largest measured C emissions from land use in the tropics. The 6260 ha of mangroves and converted mangroves in the Montecristi Province are estimated to contain 3,841,490 Mg of C. Mangroves represented 76% of this area but currently store 97% of the carbon in this coastal wetland (3,696,722 Mg C). Converted lands store only 4% of the total ecosystem C (144,778 Mg C) while they comprised 24% of the area. By these metrics the replacement of mangroves with shrimp and salt ponds has resulted in estimated emissions from this region totaling 3.8 million Mg CO2e or approximately 21% of the total C prior to conversion. Given the high C stocks of mangroves, the high emissions from their conversion, and the other important

  8. Global carbon dioxide emissions from inland waters

    Science.gov (United States)

    Raymond, Peter A.; Hartmann, Jens; Lauerwald, Ronny; Sobek, Sebastian; McDonald, Cory P.; Hoover, Mark; Butman, David; Striegl, Rob; Mayorga, Emilio; Humborg, Christoph; Kortelainen, Pirkko; Durr, Hans H.; Meybeck, Michel; Ciais, Philippe; Guth, Peter

    2013-01-01

    Carbon dioxide (CO2) transfer from inland waters to the atmosphere, known as CO2 evasion, is a component of the global carbon cycle. Global estimates of CO2 evasion have been hampered, however, by the lack of a framework for estimating the inland water surface area and gas transfer velocity and by the absence of a global CO2 database. Here we report regional variations in global inland water surface area, dissolved CO2 and gas transfer velocity. We obtain global CO2 evasion rates of 1.8   petagrams of carbon (Pg C) per year from streams and rivers and 0.32  Pg C yr−1 from lakes and reservoirs, where the upper and lower limits are respectively the 5th and 95th confidence interval percentiles. The resulting global evasion rate of 2.1 Pg C yr−1 is higher than previous estimates owing to a larger stream and river evasion rate. Our analysis predicts global hotspots in stream and river evasion, with about 70 per cent of the flux occurring over just 20 per cent of the land surface. The source of inland water CO2 is still not known with certainty and new studies are needed to research the mechanisms controlling CO2 evasion globally.

  9. Carbon dioxide and climate

    International Nuclear Information System (INIS)

    Global climate change is a serious environmental concern, and the US has developed ''An Action Agenda'' to deal with it. At the heart of the US effort is the US Global Change Research Program (USGCRP), which has been developed by the Committee on Earth and Environmental Sciences (CEES) of the Federal Coordinating Council for Sciences, Engineering, and Technology (FCCSET). The USGCRP will provide the scientific basis for sound policy making on the climate-change issue. The DOE contribution to the USGCRP is the Carbon Dioxide Research Program, which now places particular emphasis on the rapid improvement of the capability to predict global and regional climate change. DOE's Carbon Dioxide Research Program has been addressing the carbon dioxide-climate change connection for more than twelve years and has provided a solid scientific foundation for the USGCRP. The expansion of the DOE effort reflects the increased attention that the Department has placed on the issue and is reflected in the National Energy Strategy (NES) that was released in 1991. This Program Summary describes projects funded by the Carbon Dioxide Research Program during FY 1991 and gives a brief overview of objectives, organization, and accomplishments. The Environmental Sciences Division of the Office of Health and Environmental Research, Office of Energy Research supports a Carbon Dioxide Research Program to determine the scientific linkage between the rise of greenhouse gases in the atmosphere, especially carbon dioxide, and climate and vegetation change. One facet is the Core CO2 Program, a pioneering program that DOE established more than 10 years ago to understand and predict the ways that fossil-fuel burning could affect atmospheric CO2 concentration, global climate, and the Earth's biosphere. Major research areas are: global carbon cycle; climate detection and models of climate change; vegetation research; resource analysis; and, information and integration

  10. Measurement of carbon capture efficiency and stored carbon leakage

    Science.gov (United States)

    Keeling, Ralph F.; Dubey, Manvendra K.

    2013-01-29

    Data representative of a measured carbon dioxide (CO.sub.2) concentration and of a measured oxygen (O.sub.2) concentration at a measurement location can be used to determine whether the measured carbon dioxide concentration at the measurement location is elevated relative to a baseline carbon dioxide concentration due to escape of carbon dioxide from a source associated with a carbon capture and storage process. Optionally, the data can be used to quantify a carbon dioxide concentration increase at the first location that is attributable to escape of carbon dioxide from the source and to calculate a rate of escape of carbon dioxide from the source by executing a model of gas-phase transport using at least the first carbon dioxide concentration increase. Related systems, methods, and articles of manufacture are also described.

  11. Carbon nanotube core graphitic shell hybrid fibers.

    Science.gov (United States)

    Hahm, Myung Gwan; Lee, Jae-Hwang; Hart, Amelia H C; Song, Sung Moo; Nam, Jaewook; Jung, Hyun Young; Hashim, Daniel Paul; Li, Bo; Narayanan, Tharangattu N; Park, Chi-Dong; Zhao, Yao; Vajtai, Robert; Kim, Yoong Ahm; Hayashi, Takuya; Ku, Bon-Cheol; Endo, Morinobu; Barrera, Enrique; Jung, Yung Joon; Thomas, Edwin L; Ajayan, Pulickel M

    2013-12-23

    A carbon nanotube yarn core graphitic shell hybrid fiber was fabricated via facile heat treatment of epoxy-based negative photoresist (SU-8) on carbon nanotube yarn. The effective encapsulation of carbon nanotube yarn in carbon fiber and a glassy carbon outer shell determines their physical properties. The higher electrical conductivity (than carbon fiber) of the carbon nanotube yarn overcomes the drawbacks of carbon fiber/glassy carbon, and the better properties (than carbon nanotubes) of the carbon fiber/glassy carbon make up for the lower thermal and mechanical properties of the carbon nanotube yarn via synergistic hybridization without any chemical doping and additional processes. PMID:24224730

  12. 21st Century Water Conservation Principles

    Science.gov (United States)

    Narayanan, M.

    2013-12-01

    This is an encore presentation of what was presented at the 2012 AGU International Conference. It was entitled: 'The Importance of Water Conservation in the 21st Century.' The poster presentation, however, has been redesigned and reorganized with new, revised perspectives. The importance of water conservation principles has been emphasized. The population of United States has more than doubled over the past 50 years. The need for water however, has tripled. The EPA estimates that more than 36 states face water shortage during the forthcoming years. The EPA has prepared a plan for achieving environmental and energy performance. This will be coupled with leadership and accountability. Carbon neutrality is also of prime importance. The objective is to focus on six important, essential areas. 1. Efficient use of already available energy resources. 2. Intelligent water consumption and focusing on water conservation. 3. Expand the use of renewable energy resources. 4. Explore innovative transportation systems and methodologies. 5. Change building codes and promote high performance sustainable buildings. 6. Focus on developing creative environment management systems. Greenhouse gases such as carbon dioxide occur naturally in the atmosphere. Carbon dioxide is also emitted to the atmosphere through a variety of natural processes and also some human activities. However, fluorinated gases are emitted to the atmosphere solely through human activities, because they are created by humans. It is very important to observe that water conservation is probably the most cost-effective way to reduce our demand for water. Furthermore, it is certainly environmentally justifiable. The Environmental Protection Agency has a plan called E2PLAN. It is EPA's plan for achieving energy and environmental performance, leadership, accountability, and carbon neutrality. In June 2011, the EPA published a comprehensive, multi-year planning document called Strategic Sustainability Performance Plan. The

  13. 21 cm cosmology in the 21st century

    International Nuclear Information System (INIS)

    Imaging the Universe during the first hundreds of millions of years remains one of the exciting challenges facing modern cosmology. Observations of the redshifted 21 cm line of atomic hydrogen offer the potential of opening a new window into this epoch. This will transform our understanding of the formation of the first stars and galaxies and of the thermal history of the Universe. A new generation of radio telescopes is being constructed for this purpose with the first results starting to trickle in. In this review, we detail the physics that governs the 21 cm signal and describe what might be learnt from upcoming observations. We also generalize our discussion to intensity mapping of other atomic and molecular lines. (review article)

  14. Terrestrial Carbon Cycle Variability

    Science.gov (United States)

    Baldocchi, Dennis; Ryu, Youngryel; Keenan, Trevor

    2016-01-01

    A growing literature is reporting on how the terrestrial carbon cycle is experiencing year-to-year variability because of climate anomalies and trends caused by global change. As CO 2 concentration records in the atmosphere exceed 50 years and as satellite records reach over 30 years in length, we are becoming better able to address carbon cycle variability and trends. Here we review how variable the carbon cycle is, how large the trends in its gross and net fluxes are, and how well the signal can be separated from noise. We explore mechanisms that explain year-to-year variability and trends by deconstructing the global carbon budget. The CO 2 concentration record is detecting a significant increase in the seasonal amplitude between 1958 and now. Inferential methods provide a variety of explanations for this result, but a conclusive attribution remains elusive. Scientists have reported that this trend is a consequence of the greening of the biosphere, stronger northern latitude photosynthesis, more photosynthesis by semi-arid ecosystems, agriculture and the green revolution, tropical temperature anomalies, or increased winter respiration. At the global scale, variability in the terrestrial carbon cycle can be due to changes in constituent fluxes, gross primary productivity, plant respiration and heterotrophic (microbial) respiration, and losses due to fire, land use change, soil erosion, or harvesting. It remains controversial whether or not there is a significant trend in global primary productivity (due to rising CO 2, temperature, nitrogen deposition, changing land use, and preponderance of wet and dry regions). The degree to which year-to-year variability in temperature and precipitation anomalies affect global primary productivity also remains uncertain. For perspective, interannual variability in global gross primary productivity is relatively small (on the order of 2 Pg-C y -1) with respect to a large and uncertain background (123 +/- 4 Pg-C y -1), and

  15. Carbon fuel particles used in direct carbon conversion fuel cells

    Science.gov (United States)

    Cooper, John F.; Cherepy, Nerine

    2012-10-09

    A system for preparing particulate carbon fuel and using the particulate carbon fuel in a fuel cell. Carbon particles are finely divided. The finely dividing carbon particles are introduced into the fuel cell. A gas containing oxygen is introduced into the fuel cell. The finely divided carbon particles are exposed to carbonate salts, or to molten NaOH or KOH or LiOH or mixtures of NaOH or KOH or LiOH, or to mixed hydroxides, or to alkali and alkaline earth nitrates.

  16. Effect of Population Structure Change on Carbon Emission in China

    Directory of Open Access Journals (Sweden)

    Wen Guo

    2016-03-01

    Full Text Available This paper expanded the Logarithmic Mean Divisia Index (LMDI model through the introduction of urbanization, residents’ consumption, and other factors, and decomposed carbon emission changes in China into carbon emission factor effect, energy intensity effect, consumption inhibitory factor effect, urbanization effect, residents’ consumption effect, and population scale effect, and then explored contribution rates and action mechanisms of the above six factors on change in carbon emissions in China. Then, the effect of population structure change on carbon emission was analyzed by taking 2003–2012 as a sample period, and combining this with the panel data of 30 provinces in China. Results showed that in 2003–2012, total carbon emission increased by 4.2117 billion tons in China. The consumption inhibitory factor effect, urbanization effect, residents’ consumption effect, and population scale effect promoted the increase in carbon emissions, and their contribution ratios were 27.44%, 12.700%, 74.96%, and 5.90%, respectively. However, the influence of carbon emission factor effect (−2.54% and energy intensity effect (−18.46% on carbon emissions were negative. Population urbanization has become the main population factor which affects carbon emission in China. The “Eastern aggregation” phenomenon caused the population scale effect in the eastern area to be significantly higher than in the central and western regions, but the contribution rate of its energy intensity effect (−11.10 million tons was significantly smaller than in the central (−21.61 million tons and western regions (−13.29 million tons, and the carbon emission factor effect in the central area (−3.33 million tons was significantly higher than that in the eastern (−2.00 million tons and western regions (−1.08 million tons. During the sample period, the change in population age structure, population education structure, and population occupation structure

  17. DISCOVERY OF CARBON RADIO RECOMBINATION LINES IN M82

    Energy Technology Data Exchange (ETDEWEB)

    Morabito, Leah K.; Oonk, J. B. R.; Salgado, Francisco; Röttgering, H. J. A.; Tielens, A. G. G. M.; Haverkorn, Marijke [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Toribio, M. Carmen; Heald, George [Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, 7990 AA Dwingeloo (Netherlands); Beck, Rainer; Adebahr, Björn [MPI für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Best, Philip [SUPA, Institute for Astronomy, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Beswick, Robert [Jodrell Bank Centre for Astrophysics, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Bonafede, Annalisa; Brüggen, Marcus [Hamburg Observatory, University of Hamburg, Gojenbergsweg 112, D-21029 Hamburg (Germany); Brunetti, Gianfranco [INAF-Istituto di Radioastronomia, Via P. Gobetti 101, I-40129 Bologna (Italy); Chyży, Krzysztof T. [Obserwatorium Astronomiczne Uniwersytetu Jagiellońskiego, ul. Orla 171, 30-244 Kraków (Poland); Conway, J. E.; Horellou, Cathy [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-43992 Onsala (Sweden); Van Driel, Wim [GEPI, Observatoire de Paris, UMR 8111, CNRS, Université Paris Diderot, 5 Place Jules Janssen, F-92190 Meudon (France); Gregson, Jonathan, E-mail: morabito@strw.leidenuniv.nl [Department of Physical Sciences, The Open University, Milton Keynes MK7 6AA (United Kingdom); and others

    2014-11-10

    Carbon radio recombination lines (RRLs) at low frequencies (≲ 500 MHz) trace the cold, diffuse phase of the interstellar medium, which is otherwise difficult to observe. We present the detection of carbon RRLs in absorption in M82 with the Low Frequency Array in the frequency range of 48-64 MHz. This is the first extragalactic detection of RRLs from a species other than hydrogen, and below 1 GHz. Since the carbon RRLs are not detected individually, we cross-correlated the observed spectrum with a template spectrum of carbon RRLs to determine a radial velocity of 219 km s{sup –1}. Using this radial velocity, we stack 22 carbon-α transitions from quantum levels n = 468-508 to achieve an 8.5σ detection. The absorption line profile exhibits a narrow feature with peak optical depth of 3 × 10{sup –3} and FWHM of 31 km s{sup –1}. Closer inspection suggests that the narrow feature is superimposed on a broad, shallow component. The total line profile appears to be correlated with the 21 cm H I line profile reconstructed from H I absorption in the direction of supernova remnants in the nucleus. The narrow width and centroid velocity of the feature suggests that it is associated with the nuclear starburst region. It is therefore likely that the carbon RRLs are associated with cold atomic gas in the direction of the nucleus of M82.

  18. Flexible Carbon Aerogels

    Directory of Open Access Journals (Sweden)

    Marina Schwan

    2016-09-01

    Full Text Available Carbon aerogels are highly porous materials with a large inner surface area. Due to their high electrical conductivity they are excellent electrode materials in supercapacitors. Their brittleness, however, imposes certain limitations in terms of applicability. In that context, novel carbon aerogels with varying degree of flexibility have been developed. These highly porous, light aerogels are characterized by a high surface area and possess pore structures in the micrometer range, allowing for a reversible deformation of the aerogel network. A high ratio of pore size to particle size was found to be crucial for high flexibility. For dynamic microstructural analysis, compression tests were performed in-situ within a scanning electron microscope allowing us to directly visualize the microstructural flexibility of an aerogel. The flexible carbon aerogels were found to withstand between 15% and 30% of uniaxial compression in a reversible fashion. These findings might stimulate further research and new application fields directed towards flexible supercapacitors and batteries.

  19. Securing tropical forest carbon

    DEFF Research Database (Denmark)

    Scharlemann, Jörn P. W.; Kapos, Valerie; Campbell, Alison;

    2010-01-01

    Forest loss and degradation in the tropics contribute 6-17% of all greenhouse gas emissions. Protected areas cover 217.2 million ha (19.6%) of the world's humid tropical forests and contain c. 70.3 petagrams of carbon (Pg C) in biomass and soil to 1 m depth. Between 2000 and 2005, we estimate...... that 1.75 million ha of forest were lost from protected areas in humid tropical forests, causing the emission of 0.25-0.33 Pg C. Protected areas lost about half as much carbon as the same area of unprotected forest. We estimate that the reduction of these carbon emissions from ongoing deforestation......, although certainly not sufficient, component of an overall strategy for reducing emissions from deforestation and forest degradation (REDD)...

  20. Pyrolyzed carbon film diodes.

    Science.gov (United States)

    Morton, Kirstin C; Tokuhisa, Hideo; Baker, Lane A

    2013-11-13

    We have previously reported pyrolyzed parylene C (PPC) as a conductive carbon electrode material for use with micropipets, atomic force microscopy probes, and planar electrodes. Advantages of carbon electrode fabrication from PPC include conformal coating of high-aspect ratio micro/nanoscale features and the benefits afforded by chemical vapor deposition of carbon polymers. In this work, we demonstrate chemical surface doping of PPC through the use of previously reported methods. Chemically treated PPC films are characterized by multiple spectroscopic and electronic measurements. Pyrolyzed parylene C and doped PPC are used to construct diodes that are examined as both p-n heterojunction and Schottky barrier diodes. Half-wave rectification is achieved with PPC diodes and demonstrates the applicability of PPC as a conductive and semiconductive material in device fabrication. PMID:24090451

  1. Synthesis of Heteroaromatic Compounds by Oxidative Aromatization Using an Activated Carbon/Molecular Oxygen System

    Directory of Open Access Journals (Sweden)

    Masahiko Hayashi

    2009-08-01

    Full Text Available A variety of heteroaromatic compounds, such as substituted pyridines, pyrazoles, indoles, 2-substituted imidazoles, 2-substituted imidazoles, 2-arylbenzazoles and pyrimidin-2(1H-ones are synthesized by oxidative aromatization using the activated carbon and molecular oxygen system. Mechanistic study focused on the role of activated carbon in the synthesis of 2-arylbenzazoles is also discussed. In the final section, we will disclose the efficient synthesis of substituted 9,10-anthracenes via oxidative aromatization.

  2. A study of fuel poverty and low-carbon synergies in social housing

    OpenAIRE

    D. Jenkins(University of York, UK); Middlemiss, L; Pharoah, R

    2011-01-01

    This socio-technical pilot involved qualitative interviews with social housing tenants, combined with basic energy modelling of the individual dwellings to estimate the carbon emissions of that house. The study aimed to investigate the relationship between fuel poverty and carbon-saving synergies in the UK domestic housing stock. Fuel poverty, the circumstance where a household spends more than 10% of its income on energy bills, is predicted as being 21% of the entire domestic stock. The fuel...

  3. Repairable Woven Carbon Fiber Composites with Full Recyclability Enabled by Malleable Polyimine Networks.

    Science.gov (United States)

    Taynton, Philip; Ni, Huagang; Zhu, Chengpu; Yu, Kai; Loob, Samuel; Jin, Yinghua; Qi, H Jerry; Zhang, Wei

    2016-04-20

    Carbon-fiber reinforced composites are prepared using catalyst-free malleable polyimine networks as binders. An energy neutral closed-loop recycling process has been developed, enabling recovery of 100% of the imine components and carbon fibers in their original form. Polyimine films made using >21% recycled content exhibit no loss of mechanical performance, therefore indicating all of the thermoset composite material can be recycled and reused for the same purpose.

  4. Horizontal carbon nanotube alignment.

    Science.gov (United States)

    Cole, Matthew T; Cientanni, Vito; Milne, William I

    2016-09-21

    The production of horizontally aligned carbon nanotubes offers a rapid means of realizing a myriad of self-assembled near-atom-scale technologies - from novel photonic crystals to nanoscale transistors. The ability to reproducibly align anisotropic nanostructures has huge technological value. Here we review the present state-of-the-art in horizontal carbon nanotube alignment. For both in and ex situ approaches, we quantitatively assess the reported linear packing densities alongside the degree of alignment possible for each of these core methodologies. PMID:27546174

  5. Nanotube composite carbon fibers

    Science.gov (United States)

    Andrews, R.; Jacques, D.; Rao, A. M.; Rantell, T.; Derbyshire, F.; Chen, Y.; Chen, J.; Haddon, R. C.

    1999-08-01

    Single walled carbon nanotubes (SWNTs) were dispersed in isotropic petroleum pitch matrices to form nanotube composite carbon fibers with enhanced mechanical and electrical properties. We find that the tensile strength, modulus, and electrical conductivity of a pitch composite fiber with 5 wt % loading of purified SWNTs are enhanced by ˜90%, ˜150%, and 340% respectively, as compared to the corresponding values in unmodified isotropic pitch fibers. These results serve to highlight the potential that exits for developing a spectrum of material properties through the selection of the matrix, nanotube dispersion, alignment, and interfacial bonding.

  6. Carbon Nanotube Solar Cells

    OpenAIRE

    Klinger, Colin; Patel, Yogeshwari; Postma, Henk W. Ch.

    2012-01-01

    We present proof-of-concept all-carbon solar cells. They are made of a photoactive side of predominantly semiconducting nanotubes for photoconversion and a counter electrode made of a natural mixture of carbon nanotubes or graphite, connected by a liquid electrolyte through a redox reaction. The cells do not require rare source materials such as In or Pt, nor high-grade semiconductor processing equipment, do not rely on dye for photoconversion and therefore do not bleach, and are easy to fabr...

  7. Carbon cycle makeover

    DEFF Research Database (Denmark)

    Canfield, Donald Eugene; Kump, Lee R.

    2013-01-01

    remaining in sediments after respiration leave a residual of oxygen in the atmosphere. The source of oxygen to the atmosphere represented by organic matter burial is balanced by oxygen sinks associated with rock weathering and chemical reaction with volcanic gases. This is the long-term carbon and oxygen...... geochemical cycle. But Earth is an old planet, and oxygen levels have changed through time (2). On page 540 of this issue, Schrag et al. (3) challenge the most commonly used geochemical approach to assess long-term changes in the coupled oxygen and carbon cycles....

  8. Pitch carbon microsphere composite

    Science.gov (United States)

    Price, H. L.; Nelson, J. B.

    1977-01-01

    Petroleum pitch carbon microspheres were prepared by flash heating emulsified pitch and carbonizing the resulting microspheres in an inert atmosphere. Microsphere composites were obtained from a mixture of microspheres and tetraester precursor pyrrone powder. Scanning electron micrographs of the composite showed that it was an aggregate of microspheres bonded together by the pyrrone at the sphere contact points, with voids in and among the microspheres. Physical, thermal, and sorption properties of the composite are described. Composite applications could include use as a honeycomb filler in elevated-temperature load-bearing sandwich boards or in patient-treatment tables for radiation treatment of tumors.

  9. Electronic properties of linear carbon chains: Resolving the controversy

    Energy Technology Data Exchange (ETDEWEB)

    Al-Backri, Amaal [Physics Department, Lancaster University, LA1 4YB Lancaster (United Kingdom); College of Science, Baghdad University, Al-Jaderyia Campus, Baghdad (Iraq); Zólyomi, Viktor; Lambert, Colin J. [Physics Department, Lancaster University, LA1 4YB Lancaster (United Kingdom)

    2014-03-14

    Literature values for the energy gap of long one-dimensional carbon chains vary from as little as 0.2 eV to more than 4 eV. To resolve this discrepancy, we use the GW many-body approach to calculate the band gap E{sub g} of an infinite carbon chain. We also compute the energy dependence of the attenuation coefficient β governing the decay with chain length of the electrical conductance of long chains and compare this with recent experimental measurements of the single-molecule conductance of end-capped carbon chains. For long chains, we find E{sub g} = 2.16 eV and an upper bound for β of 0.21 Å{sup −1}.

  10. 21 reports of future industry

    International Nuclear Information System (INIS)

    This book deals with 21 reports on future industry, which contain revolution of digital educations, genetic engineering, the newest medical device, environmental industry, artificial intelligence, virtual reality, bio-green revolution, energy of the future, advanced concept computer, e-commerce, digital cash, game industry, information technology for future, next DRAM, information protection industry, robot to replace manpower, medium for information display, navigation systems, a space development, design industry and, home automation.

  11. Solar hydrogen hybrid system with carbon storage

    International Nuclear Information System (INIS)

    A complete solar hydrogen hybrid system has been developed to convert, store and use energy from renewable energy sources. The theoretical model has been implemented in a dynamic model-based software environment and applied to real data to simulate its functioning over a one-year period. Results are used to study system design and performance. A photovoltaic sub-system directly drives a residential load and, if a surplus of energy is available, an electrolyzer to produce hydrogen which is stored in a cluster of nitrogen-cooled tanks filled with AX-21 activated carbons. When the power converted from the sun is not sufficient to cover load needs, hydrogen is desorbed from activated carbon tanks and sent to the fuel-cell sub-system so to obtain electrical energy. A set of sub-systems (bus-bar, buck- and boost-converters, inverter, control circuits), handle the electrical power according to a Programmable Logic Control unit so that the load can be driven with adequate Quality of Service. Hydrogen storage is achieved through physisorption (weak van der Waals interactions) between carbon atoms and hydrogen molecules occurring at low temperature (77 K) in carbon porous solids at relatively low pressures. Storage modeling has been developed using a Langmuir-Freundlich 1st type isotherm and experimental data available in literature. Physisorption storage provides safer operations along with good gravimetric (10.8% at 6 MPa) and volumetric (32.5 g/l at 6 MPa) storage capacities at costs that can be comparable to, or smaller than, ordinary storage techniques (compression or liquefaction). Several test runs have been performed on residential user data-sets: the system is capable of providing grid independence and can be designed to yield a surplus production of hydrogen which can be used to recharge electric car batteries or fill tanks for non-stationary uses. (author)

  12. Iron, phytoplankton growth, and the carbon cycle.

    Science.gov (United States)

    Street, Joseph H; Paytan, Adina

    2005-01-01

    Iron is an essential nutrient for all living organisms. Iron is required for the synthesis of chlorophyll and of several photosynthetic electron transport proteins and for the reduction of CO2, SO4(2-), and NO3(-) during the photosynthetic production of organic compounds. Iron concentrations in vast areas of the ocean are very low (iron in oxic seawater. Low iron concentrations have been shown to limit primary production rates, biomass accumulation, and ecosystem structure in a variety of open-ocean environments, including the equatorial Pacific, the subarctic Pacific and the Southern Ocean and even in some coastal areas. Oceanic primary production, the transfer of carbon dioxide into organic carbon by photosynthetic plankton (phytoplankton), is one process by which atmospheric CO2 can be transferred to the deep ocean and sequestered for long periods of time. Accordingly, iron limitation of primary producers likely plays a major role in the global carbon cycle. It has been suggested that variations in oceanic primary productivity, spurred by changes in the deposition of iron in atmospheric dust, control atmospheric CO2 concentrations, and hence global climate, over glacial-interglacial timescales. A contemporary application of this "iron hypothesis" promotes the large-scale iron fertilization of ocean regions as a means of enhancing the ability of the ocean to store anthropogenic CO2 and mitigate 21st century climate change. Recent in situ iron enrichment experiments in the HNLC regions, however, cast doubt on the efficacy and advisability of iron fertilization schemes. The experiments have confirmed the role of iron in regulating primary productivity, but resulted in only small carbon export fluxes to the depths necessary for long-term sequestration. Above all, these experiments and other studies of iron biogeochemistry over the last two decades have begun to illustrate the great complexity of the ocean system. Attempts to engineer this system are likely to

  13. Transcriptional Regulation of TMP21 by NFAT

    Directory of Open Access Journals (Sweden)

    Xia Kun

    2011-03-01

    Full Text Available Abstract Background TMP21 is a member of the p24 cargo protein family, which is involved in protein transport between the Golgi apparatus and ER. Alzheimer's Disease (AD is the most common neurodegenerative disorder leading to dementia and deposition of amyloid β protein (Aβ is the pathological feature of AD pathogenesis. Knockdown of TMP21 expression by siRNA causes a sharp increase in Aβ production; however the underlying mechanism by which TMP21 regulates Aβ generation is unknown, and human TMP21 gene expression regulation has not yet been studied. Results In this report we have cloned a 3.3-kb fragment upstream of the human TMP21 gene. The transcription start site (TSS of the human TMP21 gene was identified. A series of nested deletions of the 5' flanking region of the human TMP21 gene were subcloned into the pGL3-basic luciferase reporter plasmid. We identified the -120 to +2 region as containing the minimal sequence necessary for TMP21 gene promoter activity. Gel shift assays revealed that the human TMP21 gene promoter contains NFAT response elements. Expression of NFAT increased TMP21 gene expression and inhibition of NFAT by siRNA reduced TMP21 gene expression. Conclusion NFAT plays a very important role in the regulation of human TMP21 gene expression. This study demonstrates that the human TMP21 gene expression is transcriptionally regulated by NFAT signaling.

  14. Atypical Down syndrome phenotype in a girl with 21;21 translocation trisomy.

    Science.gov (United States)

    Tuysuz, B; Yavuz, A; Ozdil, M; Caferler, J; Ozon, H

    2010-01-01

    We describe a girl with microcephaly, short stature, coarse face, severe growth and developmental delay, seizures, hypertonia, bilateral flexion contractures of the knees, and a de novo 21;21 translocation trisomy 21 in peripheral blood lymphocytes. Fluorescence in situ hybridization (FISH) analysis confirmed the trisomy 21 translocation using whole chromosome painting probe 21 (WCP21). Chromosome analysis which was also performed on skin fibroblasts and revealed mosaicism for a translocation trisomy 21 cell line (22.3%) as well as a second cell line consisting of one normal chromosome 21 and a small ring chromosome 21 derived from the translocation 21q21q (61%) and a third line consisting of monosomy 21 (16.7%). FISH analyses by LS121 probe for the critical (21q22.2-22.3) region of Down syndrome (DS) on interphase blood cells resulted with 30% two signals and 70% three signals, skin fibroblasts showed 84% single signal, 9% two signals and 7% three signals. The size of ring chromosome 21 in skin fibroblasts was very small and probably there was a large, more proximally located deletion including chromosome 21q22 band. We consider that the atypical DS phenotype of the patient originated from the small ring chromosome 21 and the monosomy 21 in the skin fibroblasts and other tissues not available for analysis. Therefore, the clinical findings of the patient were most similar to monosomy 21 mosaicism syndrome. PMID:20420031

  15. Springtime carbon episodes at Gosan background site revealed by total carbon, stable carbon isotopic composition, and thermal characteristics of carbonaceous particles

    Science.gov (United States)

    Jung, J.; Kawamura, K.

    2011-05-01

    In order to investigate the carbon episodes at Gosan background super-site (33.17° N, 126.10° E) in East Asia during spring of 2007 and 2008, total suspended particles (TSP) were collected and analyzed for particulate organic carbon, elemental carbon, total carbon (TC), total nitrogen (TN), and stable carbon isotopic composition (δ13C) of TC. The carbon episodes at the Gosan site were categorized as long-range transported anthropogenic pollutant (LTP) from Asian continent, Asian dust (AD) accompanying with LTP, and local pollen episodes. The stable carbon isotopic composition of TC (δ13CTC) was found to be lowest during the pollen episodes (range: -26.2 ‰ to -23.5 ‰, avg.: -25.2 ± 0.9 ‰), followed by the LTP episodes (range: -23.5 ‰ to -23.0 ‰, avg.: -23.3 ± 0.3 ‰) and the AD episodes (range: -23.3 to -20.4 %, avg.: -21.8 ± 2.0 ‰). The δ13CTC of the airborne pollens (-28.0 ‰) collected at the Gosan site showed value similar to that of tangerine fruit (-28.1 ‰) produced from Jeju Island. Based on the carbon isotope mass balance equation and the TN and TC regression approach, we found that ∼40-45 % of TC in the TSP samples during the pollen episodes was attributed to airborne pollens from Japanese cedar trees planted around tangerine farms in Jeju Island. The δ13C of citric acid in the airborne pollens (-26.3 ‰) collected at the Gosan site was similar to that in tangerine fruit (-27.4 ‰). The negative correlation between the citric acid-carbon/TC ratios and δ13CTC were obtained during the pollen episodes. These results suggest that citric acid emitted from tangerine fruit may be adsorbed on the airborne pollens and then transported to the Gosan site. Based on the thermal evolution pattern of organic aerosols during the carbon episodes, we found that organic aerosols originated from East China are more volatile on heating and are more likely to form pyrolized organic carbon than the pollen-enriched organic aerosols and organic

  16. Thermostable a-amylase from moderately halophilic Halomonas sp. AAD21

    OpenAIRE

    UZYOL, Kamil Serkan; Akbulut, Berna Sariyar; DENİZCİ, Aziz Akın; KAZAN, Dilek

    2012-01-01

    The moderately halophilic Halomonas sp. strain AAD21, which produces extracellular thermostable a-amylase, was isolated from the Çamaltı Saltern area located in İzmir, Turkey. NaCl, carbon, and nitrogen sources in the growth medium were optimized to enhance a-amylase yield. The highest enzyme yield was measured in the presence of 20% NaCl with peptone as the nitrogen and starch as the carbon sources in the fermentation broth. This microorganism was also found to utilize waste potato peel as a...

  17. Carbonation of low heat portland cement paste procured in water for different time

    Institute of Scientific and Technical Information of China (English)

    Deping Chen; Etsuo Sakai; Masaki Daimon; Yoko Ohba

    2007-01-01

    The carbonation technique was applied to accelerate the hydration of low heat portland cement (LHC). Before carbonation, the demoulded pastes were precured in water for 0, 2, 7, and 21 d, respectively. The results show that procuring time in water strongly influences the carbonation process. The phenolphthalein test indicates that the paste precured in water for a shorter time is more quickly carbonated than that for a longer time. The content of calcium hydroxide increases with increasing the procuring time in water, whereas, the amount of absorbed carbon dioxide changes contrarily. Scanning electron microscope (SEM) observation shows that portlandite always fills up big air bubbles in the paste during precuring in water, and the mercury intrusion porosimetry (MIP) results show that there are less large capillary pores in the paste precured in water for a longer time. It is found that the paste without precuring in water has more carbon dioxide absorption during curing in carbon dioxide atmosphere, and its total pore volume decreases remarkably with an increase in the carbonation time than that precured in water. X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) surface area analyses indicate that the carbonate products are vaterite and calcite; CxSHy,, formed from carbonation has low BET surface area in comparison with that of C-S-H formed from curing in water.

  18. Method for production of carbon nanofiber mat or carbon paper

    Energy Technology Data Exchange (ETDEWEB)

    Naskar, Amit K.

    2015-08-04

    Method for the preparation of a non-woven mat or paper made of carbon fibers, the method comprising carbonizing a non-woven mat or paper preform (precursor) comprised of a plurality of bonded sulfonated polyolefin fibers to produce said non-woven mat or paper made of carbon fibers. The preforms and resulting non-woven mat or paper made of carbon fiber, as well as articles and devices containing them, and methods for their use, are also described.

  19. 19 CFR 177.21 - Applicability.

    Science.gov (United States)

    2010-04-01

    ... with the Federal Acquisition Regulations (48 CFR chapter 1) and the Defense Acquisition Regulation (48 CFR chapter 2). ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Applicability. 177.21 Section 177.21...

  20. Main: SURE1STPAT21 [PLACE

    Lifescience Database Archive (English)

    Full Text Available SURE1STPAT21 S000186 17-May-1998 (last modified) kehi Sucrose Responsive Element (S...URE); A motif conserved among genes regulated by sucrose; See also SURE2STPAT21 (S000185); Found between -18

  1. Dynamic carbon allocation significantly changed land carbon sink and carbon pool sizes

    Science.gov (United States)

    Xia, J.; Yuan, W.

    2015-12-01

    The allocation of photosynthate among the plant components (e.g., leaves, stems, and roots) plays an important role in regulating plant growth, competition, and terrestrial carbon cycle. However, the carbon allocation process is still a weak part in the earth system models (ESMs). In this study, the Integrated BIosphere Simulator (IBIS) model coupled with a dynamic carbon allocation model (IBISAL) is used to explore the impact of carbon allocation on the terrestrial carbon cycle. This dynamic carbon allocation model suggests that plants should allocate the largest part of carbon to the plant components which need to capture the most limiting resources, such as light, water and nitrogen. In comparison to the results of original IBIS model using fixed allocation ratios, the net ecosystem productivity, global biomass and soil organic carbon simulated by IBISAL model decreased by13.4% , 9.9% and 20.8%, respectively . The dynamic allocation scheme tends to benefit roots allocation. Because roots had short turnover times, high roots allocation led to the decreases of global carbon sink and carbon pool sizes. The observations showed that the carbon allocation ratios changed with temperature and precipitation. The dynamic carbon allocation model could reproduce this phenomenon correctly. The results show that the dynamic carbon allocation ratios of boreal evergreen forests and C3 grasses are consistent well with the observations. However, the IBISAL, and another three ESMs (i.e., CESM1-BGC, IPSL-CM5A-MR and NorESM1-ME models) adopting dynamic allocation scheme overestimated the stems allocation of tropical forests. This study shows the substantial influences of carbon allocation on the carbon sink and carbon pool sizes. Therefore, improving estimations of carbon allocation by ESMs are an important and effective path to reduce uncertainties in the global carbon cycle simulation and climate change prediction.

  2. Catalytic graphitization of carbon/carbon composites by lanthanum oxide

    Institute of Scientific and Technical Information of China (English)

    ZHANG Can; LU Guimin; SUN Ze; YU Jianguo

    2012-01-01

    Graphitized carbon/carbon composites were prepared by the process of catalytic graphitization with the rare-earth catalyst,lanthanum oxide (La2O3),in order to increase the degree of graphitization and reduce the electrical resistivity.The modified coal tar pitch and coal-based needle coke were used as carbon source,and a small amount of La2O3 was added to catalyze the graphitization of the disordered carbon materials.The effects of La2O3 catalyst on the graphitization degree and microstructure oftbe carbon/carbon composites were investigated by X-ray diffraction,scanning electron microscopy,and Raman spectroscopy.The results showed that La2O3 promoted the formation of more perfect and larger crystallites,and improved the electrical/mechanical properties of carbon/carbon composites.Carbon/carbon composites with a lower electrical resistivity (7.0 μΩ·m) could be prepared when adding 5 wt.% La2O3 powder with heating treatment at 2800 ℃.The catalytic effect of La2O3 for the graphitization of carbon/carbon composites was analyzed.

  3. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Memos Regarding Some of the Hazards Associated with Engine-Driven Generators, 2004-2014 January 07, 2016 Non- ... Investigations Associated with Non-Fire Carbon Monoxide from Engine-Driven Generators and Other Engine-Driven Tools, 2004– ...

  4. Carbon Monoxide Poisoning

    OpenAIRE

    Wray, Alisa

    2016-01-01

    Audience: This oral boards case is appropriate for all emergency medicine learners (residents, interns, and medical students). Introduction: Carbon monoxide (CO) is a colorless and odorless gas that typically results from combustion. It binds hemoglobin, dissociating oxygen, causing headache, weakness, confusion and possible seizure or coma. Pulse oxygen levels may be falsely elevated. Practitioners should maintain a high in...

  5. Closing carbon cycles

    NARCIS (Netherlands)

    Patel, Martin

    2001-01-01

    Fossil fuels are used as raw materials for the manufacture of synthetic organic materials, e.g. plastics, fibres, synthetic rubber, paints, solvents, fertilisers, surfactants, lubricants and bitumen. Since fossil carbon is embodied in these products they may be particularly relevant to climate ch

  6. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Flickr SlideShare All Pages & Documents Recalls & News Releases Home Recalls CPSC Recall API Recall Lawsuits Recalls by ... CO Poster Contest Toy Recall Statistics Pool Safely Home / Safety Education / Safety Education Centers En Español Carbon ...

  7. Carbon nanotube solar cells.

    Directory of Open Access Journals (Sweden)

    Colin Klinger

    Full Text Available We present proof-of-concept all-carbon solar cells. They are made of a photoactive side of predominantly semiconducting nanotubes for photoconversion and a counter electrode made of a natural mixture of carbon nanotubes or graphite, connected by a liquid electrolyte through a redox reaction. The cells do not require rare source materials such as In or Pt, nor high-grade semiconductor processing equipment, do not rely on dye for photoconversion and therefore do not bleach, and are easy to fabricate using a spray-paint technique. We observe that cells with a lower concentration of carbon nanotubes on the active semiconducting electrode perform better than cells with a higher concentration of nanotubes. This effect is contrary to the expectation that a larger number of nanotubes would lead to more photoconversion and therefore more power generation. We attribute this to the presence of metallic nanotubes that provide a short for photo-excited electrons, bypassing the load. We demonstrate optimization strategies that improve cell efficiency by orders of magnitude. Once it is possible to make semiconducting-only carbon nanotube films, that may provide the greatest efficiency improvement.

  8. Skallerup Klit's carbon footprint

    DEFF Research Database (Denmark)

    Zacho, Kristina Overgaard; Ørnstrup, Niels Holm; Zimmermann, Tine Marquard;

    by offsetting and without making actual emission reductions. Therefore the purpose of this study is to present recommendations on how Skallerup Klit can build up their business strategy using Carbon Footprint (CFP) as a tool. The CPF is calculated and assessed by using financial data in an Input-output LCA...

  9. Polyimide/carbon Nanocomposites

    Science.gov (United States)

    Harris, Frank W.

    2003-01-01

    The goal of this product is to design and characterize well-defined conductive nanocomposite materials. The materials will be composed of a polymer matrix composed of rigid-backbone polyimides, and will be filled with modified or unmodified multi-walled carbon nanotubes (MWNTs). The ultimate design of this project is to create composite materials with optical clarity and a high conductivity.

  10. City Carbon Footprint Networks

    Directory of Open Access Journals (Sweden)

    Guangwu Chen

    2016-07-01

    Full Text Available Progressive cities worldwide have demonstrated political leadership by initiating meaningful strategies and actions to tackle climate change. However, the lack of knowledge concerning embodied greenhouse gas (GHG emissions of cities has hampered effective mitigation. We analyse trans-boundary GHG emission transfers between five Australian cities and their trading partners, with embodied emission flows broken down into major economic sectors. We examine intercity carbon footprint (CF networks and disclose a hierarchy of responsibility for emissions between cities and regions. Allocations of emissions to households, businesses and government and the carbon efficiency of expenditure have been analysed to inform mitigation policies. Our findings indicate that final demand in the five largest cities in Australia accounts for more than half of the nation’s CF. City households are responsible for about two thirds of the cities’ CFs; the rest can be attributed to government and business consumption and investment. The city network flows highlight that over half of emissions embodied in imports (EEI to the five cities occur overseas. However, a hierarchy of GHG emissions reveals that overseas regions also outsource emissions to Australian cities such as Perth. We finally discuss the implications of our findings on carbon neutrality, low-carbon city concepts and strategies and allocation of subnational GHG responsibility.

  11. Isotopic investigations of carbonate growth on concrete structures

    Energy Technology Data Exchange (ETDEWEB)

    Krishnamurthy, R.V.; Schmitt, D.; Atekwana, E.A.; Baskaran, M

    2003-03-01

    Stable C and O isotope ratios were measured in carbonate minerals, growing under concrete structures from two locations in the United States. These locations were under a bridge in Michigan and under an overpass in New York. The {delta}{sup 13}C of the carbonate samples ranged from -21.6 to -31.4 per mille (with respect to V-PDB) and clearly indicated precipitation under non-equilibrium conditions. Indeed, the values in some cases were more negative than could be accounted for by existing models that invoke 4 stages of kinetic fractionation. There have been suggestions that microbial activity involving C from gasoline and other fossil fuel sources might be responsible for the relatively low C isotope ratios measured in these carbonates. To explore this possibility, {sup 14}C measurements were made in some of the samples. All samples measured for {sup 14}C contained bomb C. The range of {sup 14}C concentrations suggested a non-uniform growth rate, although possible fossil fuel-derived carbon in the system needs future investigation. The {delta}{sup 18}O values of the carbonates analyzed from Michigan range from 12.5 to 15.7 per mille (with respect to V-SMOW), with a mean value of 13.7 per mille. The {delta}{sup 18}O values of the NY samples range from 11.8 to 15.2 per mille, with a mean value of 13.1 per mille. The nearly identical mean values at both locations favors incorporation of O from atmospheric CO{sub 2} in carbonate precipitation. Additionally, the {sup 210}Pb radiometric technique was also attempted to explore the applicability of this technique in dating concrete derived carbonates as well as recent carbonates forming in a wide variety of environments. The results gave ages between 64 and 3.8 a and are consistent when compared with the date the bridge was constructed.

  12. Carbon nanotube macroelectronics

    Science.gov (United States)

    Zhang, Jialu

    In this dissertation, I discuss the application of carbon nanotubes in macroelectronis. Due to the extraordinary electrical properties such as high intrinsic carrier mobility and current-carrying capacity, single wall carbon nanotubes are very desirable for thin-film transistor (TFT) applications such as flat panel display, transparent electronics, as well as flexible and stretchable electronics. Compared with other popular channel material for TFTs, namely amorphous silicon, polycrystalline silicon and organic materials, nanotube thin-films have the advantages of low-temperature processing compatibility, transparency, and flexibility, as well as high device performance. In order to demonstrate scalable, practical carbon nanotube macroelectroncis, I have developed a platform to fabricate high-density, uniform separated nanotube based thin-film transistors. In addition, many other essential analysis as well as technology components, such as nanotube film density control, purity and diameter dependent semiconducting nanotube electrical performance study, air-stable n-type transistor fabrication, and CMOS integration platform have also been demonstrated. On the basis of the above achievement, I have further demonstrated various kinds of applications including AMOLED display electronics, PMOS and CMOS logic circuits, flexible and transparent electronics. The dissertation is structured as follows. First, chapter 1 gives a brief introduction to the electronic properties of carbon nanotubes, which serves as the background knowledge for the following chapters. In chapter 2, I will present our approach of fabricating wafer-scale uniform semiconducting carbon nanotube thin-film transistors and demonstrate their application in display electronics and logic circuits. Following that, more detailed information about carbon nanotube thin-film transistor based active matrix organic light-emitting diode (AMOLED) displays is discussed in chapter 3. And in chapter 4, a technology to

  13. Carbon sinks in temperate forests

    NARCIS (Netherlands)

    Martin, P.H.; Nabuurs, G.J.; Aubinet, M.; Karjalainen, T.; Vine, E.L.; Kinsman, J.; Heath, L.S.

    2001-01-01

    In addition to being scientifically exciting, commercially important, and environmentally essential, temperate forests have also become a key diplomatic item in international climate negotiations as potential sinks for carbon. This review presents the methods used to estimate carbon sequestration, i

  14. Carbon Monoxide (CO) Poisoning Prevention

    Science.gov (United States)

    ... What's this? Submit Button Past Emails CDC Features Carbon Monoxide (CO) Poisoning Prevention Language: English Español (Spanish) ... tornadoes), using alternative sources of power can cause carbon monoxide (CO) to build up in a home ...

  15. Dewatering Peat With Activated Carbon

    Science.gov (United States)

    Rohatgi, N. K.

    1984-01-01

    Proposed process produces enough gas and carbon to sustain itself. In proposed process peat slurry is dewatered to approximately 40 percent moisture content by mixing slurry with activated carbon and filtering with solid/liquid separation techniques.

  16. ROE Carbon Storage - Percent Change

    Data.gov (United States)

    U.S. Environmental Protection Agency — This polygon dataset depicts the percentage change in the amount of carbon stored in forests in counties across the United States, based on the difference in carbon...

  17. 38 CFR 21.8286 - Training resources.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Training resources. 21.8286 Section 21.8286 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED..., and Resources § 21.8286 Training resources. (a) Applicable 38 U.S.C. chapter 31 resource...

  18. 38 CFR 21.6290 - Training resources

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Training resources 21.6290 Section 21.6290 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED... Recipients Entering Vocational Training § 21.6290 Training resources (a) Applicable 38 U.S.C. chapter...

  19. 27 CFR 19.21 - Tax.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Tax. 19.21 Section 19.21 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS DISTILLED SPIRITS PLANTS Taxes Gallonage Taxes § 19.21 Tax. (a) A tax is imposed by 26...

  20. 14 CFR 21.127 - Tests: aircraft.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Tests: aircraft. 21.127 Section 21.127 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Production Under Type Certificate Only § 21.127 Tests: aircraft. (a)...

  1. 31 CFR 15.737-21 - Evidence.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Evidence. 15.737-21 Section 15.737-21... Administrative Enforcement Proceedings § 15.737-21 Evidence. (a) In general. The rules of evidence prevailing in... exclude evidence which is irrelevant, immaterial, or unduly repetitious. (b) Depositions. The...

  2. 36 CFR 1004.21 - Speed limits.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Speed limits. 1004.21 Section 1004.21 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.21 Speed limits. (a) Speed limits in the area administered by the Presidio Trust are as follows: (1) 15 miles...

  3. 23 CFR 1200.21 - Equipment.

    Science.gov (United States)

    2010-04-01

    ... 402 program, in the absence of which the State shall follow the applicable procedures in 49 CFR part... 23 Highways 1 2010-04-01 2010-04-01 false Equipment. 1200.21 Section 1200.21 Highways NATIONAL... Implementation and Management of the Highway Safety Program § 1200.21 Equipment. (a) Title. Except as provided...

  4. 10 CFR 850.21 - Hazard assessment.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Hazard assessment. 850.21 Section 850.21 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Specific Program Requirements § 850.21 Hazard... must conduct a beryllium hazard assessment that includes an analysis of existing conditions,...

  5. 28 CFR 26.21 - Definitions.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Definitions. 26.21 Section 26.21 Judicial Administration DEPARTMENT OF JUSTICE DEATH SENTENCES PROCEDURES Certification Process for State Capital Counsel Systems § 26.21 Definitions. For purposes of this part, the term— Appropriate state official means...

  6. 32 CFR 21.625 - Contract.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Contract. 21.625 Section 21.625 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE DoD GRANT AND AGREEMENT REGULATIONS DoD GRANTS AND AGREEMENTS-GENERAL MATTERS Definitions § 21.625 Contract. See the definition for procurement contract in...

  7. 36 CFR 2.21 - Smoking.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Smoking. 2.21 Section 2.21... PROTECTION, PUBLIC USE AND RECREATION § 2.21 Smoking. (a) The superintendent may designate a portion of a park area, or all or a portion of a building, structure or facility as closed to smoking when...

  8. 49 CFR 355.21 - Regulatory review.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Regulatory review. 355.21 Section 355.21... AND REGULATIONS AFFECTING INTERSTATE MOTOR CARRIER OPERATIONS Requirements § 355.21 Regulatory review... review are provided in the appendix to this part. (b) Responsibility. The State agency designated as...

  9. 32 CFR 2001.21 - Original classification.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Original classification. 2001.21 Section 2001.21... Markings § 2001.21 Original classification. (a) Primary markings. At the time of original classification, the following shall be indicated in a manner that is immediately apparent: (1)...

  10. 14 CFR 21.139 - Quality control.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Quality control. 21.139 Section 21.139... PROCEDURES FOR PRODUCTS AND PARTS Production Certificates § 21.139 Quality control. The applicant must show that he has established and can maintain a quality control system for any product, for which...

  11. 7 CFR 1491.21 - Funding.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Funding. 1491.21 Section 1491.21 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF... Agreements and Conservation Easement Deeds § 1491.21 Funding. (a) Subject to the statutory limits, the...

  12. 45 CFR 402.21 - Fiscal control.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 2 2010-10-01 2010-10-01 false Fiscal control. 402.21 Section 402.21 Public Welfare Regulations Relating to Public Welfare OFFICE OF REFUGEE RESETTLEMENT, ADMINISTRATION FOR CHILDREN... Administration of Grants § 402.21 Fiscal control. (a) Fiscal control and accounting procedures must be...

  13. 28 CFR 551.21 - Birth control.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Birth control. 551.21 Section 551.21... Birth Control, Pregnancy, Child Placement, and Abortion § 551.21 Birth control. Medical staff shall provide an inmate with advice and consultation about methods for birth control and, where...

  14. 10 CFR 1022.21 - Property management.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Property management. 1022.21 Section 1022.21 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) COMPLIANCE WITH FLOODPLAIN AND WETLAND ENVIRONMENTAL REVIEW REQUIREMENTS Other Requirements § 1022.21 Property management. (a) If property in a floodplain or wetland...

  15. 38 CFR 21.4507 - Advertising.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Advertising. 21.4507 Section 21.4507 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Education Loans § 21.4507 Advertising. (a) General. No...

  16. 9 CFR 91.21 - Ventilation.

    Science.gov (United States)

    2010-01-01

    ... mechanical ventilation that will furnish a complete change of air in each compartment every 2 minutes when... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Ventilation. 91.21 Section 91.21... LIVESTOCK FOR EXPORTATION Inspection of Vessels and Accommodations § 91.21 Ventilation. Each...

  17. 27 CFR 21.126 - Safrole.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Safrole. 21.126 Section 21.126 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.126 Safrole....

  18. 40 CFR 1508.21 - NEPA process.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false NEPA process. 1508.21 Section 1508.21 Protection of Environment COUNCIL ON ENVIRONMENTAL QUALITY TERMINOLOGY AND INDEX § 1508.21 NEPA process. NEPA process means all measures necessary for compliance with the requirements of section 2 and title I of NEPA....

  19. 7 CFR 632.21 - Reclamation plan.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Reclamation plan. 632.21 Section 632.21 Agriculture... AGRICULTURE LONG TERM CONTRACTING RURAL ABANDONED MINE PROGRAM Participation § 632.21 Reclamation plan. (a) Responsibility. Land users are responsible for developing a reclamation plan that will serve as a basis for...

  20. 29 CFR 1903.21 - State administration.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false State administration. 1903.21 Section 1903.21 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR INSPECTIONS, CITATIONS AND PROPOSED PENALTIES § 1903.21 State administration. Nothing in this part 1903...

  1. 25 CFR 140.21 - Gambling.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Gambling. 140.21 Section 140.21 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FINANCIAL ACTIVITIES LICENSED INDIAN TRADERS § 140.21 Gambling. Gambling, by dice, cards, or in any way whatever, is strictly prohibited in any licensed trader's store...

  2. 24 CFR 21.670 - Suspension.

    Science.gov (United States)

    2010-04-01

    ... CFR part 9, subpart 9.4) and the common rule, Government-wide Debarment and Suspension (Nonprocurement... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Suspension. 21.670 Section 21.670... GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (GRANTS) Definitions § 21.670 Suspension. Suspension means...

  3. 14 CFR 21.31 - Type design.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Type design. 21.31 Section 21.31... PROCEDURES FOR PRODUCTS AND PARTS Type Certificates § 21.31 Type design. The type design consists of— (a) The... configuration and the design features of the product shown to comply with the requirements of that part of...

  4. 12 CFR 622.21 - Computing time.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Computing time. 622.21 Section 622.21 Banks and... Formal Hearings § 622.21 Computing time. (a) General rule. In computing any period of time prescribed or... run is not to be included. The last day so computed shall be included, unless it is a Saturday,...

  5. 32 CFR 21.670 - Procurement contract.

    Science.gov (United States)

    2010-07-01

    ... detailed definition for contract at 48 CFR 2.101. ... 32 National Defense 1 2010-07-01 2010-07-01 false Procurement contract. 21.670 Section 21.670... REGULATIONS DoD GRANTS AND AGREEMENTS-GENERAL MATTERS Definitions § 21.670 Procurement contract. A...

  6. 22 CFR 21.1 - Policy.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Policy. 21.1 Section 21.1 Foreign Relations DEPARTMENT OF STATE PERSONNEL INDEMNIFICATION OF EMPLOYEES § 21.1 Policy. (a) The Department of State may indemnify an employee for any verdict, judgment, or other monetary award which is rendered against...

  7. 42 CFR 406.21 - Individual enrollment.

    Science.gov (United States)

    2010-10-01

    ... on substantial gainful activity (20 CFR 404.1571-404.1574). It continues for 7 full months after that... 42 Public Health 2 2010-10-01 2010-10-01 false Individual enrollment. 406.21 Section 406.21 Public... HOSPITAL INSURANCE ELIGIBILITY AND ENTITLEMENT Premium Hospital Insurance § 406.21 Individual...

  8. 24 CFR 21.655 - Individual.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Individual. 21.655 Section 21.655 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (GRANTS) Definitions § 21.655 Individual. Individual means...

  9. 42 CFR 21.45 - Rating values.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Rating values. 21.45 Section 21.45 Public Health... Appointment § 21.45 Rating values. The examination of every candidate for appointment to any grade in the... values for each part of the examination as are prescribed by the Surgeon General. No candidate...

  10. 29 CFR 42.21 - Data collection.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Data collection. 42.21 Section 42.21 Labor Office of the Secretary of Labor COORDINATED ENFORCEMENT § 42.21 Data collection. (a) For each protective statute, ESA... completed based on complaints. (g) The National Committee shall review the data collection systems of...

  11. 10 CFR 21.62 - Criminal penalties.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Criminal penalties. 21.62 Section 21.62 Energy NUCLEAR REGULATORY COMMISSION REPORTING OF DEFECTS AND NONCOMPLIANCE Enforcement § 21.62 Criminal penalties. (a) Section 223 of the Atomic Energy Act of 1954, as amended, provides for criminal sanctions for...

  12. 14 CFR 21.35 - Flight tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flight tests. 21.35 Section 21.35... PROCEDURES FOR PRODUCTS AND PARTS Type Certificates § 21.35 Flight tests. (a) Each applicant for an aircraft...) That the aircraft conforms with the type design; and (4) That the Administrator received a flight...

  13. 34 CFR 304.21 - Allowable costs.

    Science.gov (United States)

    2010-07-01

    ... Grantee § 304.21 Allowable costs. In addition to the allowable costs established in the Education Department General Administrative Regulations in 34 CFR 75.530 through 75.562, the following items are... 34 Education 2 2010-07-01 2010-07-01 false Allowable costs. 304.21 Section 304.21...

  14. 42 CFR 21.54 - Students.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Students. 21.54 Section 21.54 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES PERSONNEL COMMISSIONED OFFICERS Appointment § 21.54 Students. A potential candidate for appointment in the Regular Corps who is pursuing a course of instruction which, upon completion,...

  15. 40 CFR 406.21 - Specialized definitions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Specialized definitions. 406.21 Section 406.21 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GRAIN MILLS POINT SOURCE CATEGORY Corn Dry Milling Subcategory § 406.21 Specialized...

  16. 50 CFR 82.21 - Copyrights.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Copyrights. 82.21 Section 82.21 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED... (MARINE MAMMAL PROTECTION ACT OF 1972) Administration § 82.21 Copyrights. Where research conducted under...

  17. 40 CFR 21.1 - Scope.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Scope. 21.1 Section 21.1 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL SMALL BUSINESS § 21.1 Scope. This part establishes procedures for the issuance by EPA of the statements, referred to in section 7(g) of the Small Business...

  18. 7 CFR 2902.21 - Disposable containers.

    Science.gov (United States)

    2010-01-01

    ... Guideline, 40 CFR 247.10. EPA provides recovered materials content recommendations for paper and paper... 7 Agriculture 15 2010-01-01 2010-01-01 false Disposable containers. 2902.21 Section 2902.21... Items § 2902.21 Disposable containers. (a) Definition. Products designed to be used for...

  19. 29 CFR 779.21 - Enterprise.

    Science.gov (United States)

    2010-07-01

    ... leasing arrangements, but shall not include the related activities performed for such enterprise by an... 29 Labor 3 2010-07-01 2010-07-01 false Enterprise. 779.21 Section 779.21 Labor Regulations... OR SERVICES General Some Basic Definitions § 779.21 Enterprise. (a) Section 3(r) of the Act...

  20. 14 CFR 21.73 - Eligibility.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Eligibility. 21.73 Section 21.73 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Provisional Type Certificates § 21.73 Eligibility. (a) Any manufacturer...

  1. 42 CFR 61.21 - Interest.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Interest. 61.21 Section 61.21 Public Health PUBLIC... Regular Fellowships § 61.21 Interest. Any interest earned through deposit or investment by the sponsoring... such interest is received by the sponsoring institution....

  2. 32 CFR 21.665 - Nonprocurement instrument.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Nonprocurement instrument. 21.665 Section 21.665... REGULATIONS DoD GRANTS AND AGREEMENTS-GENERAL MATTERS Definitions § 21.665 Nonprocurement instrument. A legal instrument other than a procurement contract. Examples include instruments of financial assistance, such...

  3. 22 CFR 212.21 - Public records.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Public records. 212.21 Section 212.21 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT PUBLIC INFORMATION Availability of Information for Public Inspection and Copying § 212.21 Public records. In accordance with this subpart, USAID makes the...

  4. 22 CFR 228.21 - Ocean transportation.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Ocean transportation. 228.21 Section 228.21... for USAID Financing § 228.21 Ocean transportation. (a) The Cargo Preference Act of 1954, Section 901(b... transportation services is determined by the flag registry of the vessel. (1) When the authorized source...

  5. 22 CFR 192.21 - Applicable benefits.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Applicable benefits. 192.21 Section 192.21... Soldiers' and Sailors' Civil Relief Act to Captive Situations § 192.21 Applicable benefits. (a) Eligible persons are entitled to the benefits provided by the Soldiers' and Sailors' Civil Relief Act of 1940 (50...

  6. 22 CFR 191.21 - Applicable benefits.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Applicable benefits. 191.21 Section 191.21 Foreign Relations DEPARTMENT OF STATE HOSTAGE RELIEF HOSTAGE RELIEF ASSISTANCE Medical Benefits § 191.21 Applicable benefits. A person eligible for benefits under this part shall be eligible for authorized...

  7. 7 CFR 983.21 - Person.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Person. 983.21 Section 983.21 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and... NEW MEXICO Definitions § 983.21 Person. Person means an individual, partnership, limited...

  8. 29 CFR 90.21 - Study.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Study. 90.21 Section 90.21 Labor Office of the Secretary of... Study With Respect to Workers in Industry Which is the Subject of an Investigation for Industry Import Relief § 90.21 Study. (a) Initiation. Upon notification by the Commission, pursuant to section 224 of...

  9. 38 CFR 21.4274 - Law courses.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Law courses. 21.4274... Pursuit of Courses § 21.4274 Law courses. (a) Accredited. A law course in an accredited law school leading to a standard professional law degree will be assessed as provided in § 21.4273(a). (b)...

  10. 40 CFR 440.21 - [Reserved

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false 440.21 Section 440.21 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Aluminum Ore Subcategory § 440.21...

  11. 45 CFR 1310.21 - Safety education.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Safety education. 1310.21 Section 1310.21 Public... PROGRAM HEAD START TRANSPORTATION Special Requirements § 1310.21 Safety education. (a) Each agency must... children. The required transportation and pedestrian safety education of children and parents, except...

  12. The 21st Century Skills Movement

    Science.gov (United States)

    Johnson, Paige

    2009-01-01

    Since 2002, the Partnership for 21st Century Skills has been the leading advocacy organization in the United States focused on infusing 21st century skills into education. Its "Framework for 21st Century Learning," the result of a consensus among hundreds of stakeholders, describes the skills, knowledge, and expertise students need to succeed in…

  13. 7 CFR 11.21 - Organization.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Organization. 11.21 Section 11.21 Agriculture Office of the Secretary of Agriculture NATIONAL APPEALS DIVISION Organization And Functions § 11.21 Organization. NAD was established on October 13, 1994. Delegation of authority to the Director, NAD, appears...

  14. 42 CFR 21.24 - Physical examinations.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Physical examinations. 21.24 Section 21.24 Public... Appointment § 21.24 Physical examinations. Every candidate for appointment as an officer shall undergo such physical examination as the Surgeon General may direct, and no candidate who is not found to be...

  15. 40 CFR 405.21 - Specialized definitions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Specialized definitions. 405.21 Section 405.21 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS DAIRY PRODUCTS PROCESSING POINT SOURCE CATEGORY Fluid Products Subcategory § 405.21...

  16. 49 CFR 665.21 - Scheduling.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Scheduling. 665.21 Section 665.21 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BUS TESTING Operations § 665.21 Scheduling. (a) To schedule a bus for testing, a...

  17. 7 CFR 201.21 - Hard seed.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Hard seed. 201.21 Section 201.21 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.21 Hard seed. The label shall show the percentage of hard seed... percentage of hard seed shall not be included as part of the germination percentage....

  18. 49 CFR 228.21 - Civil penalty.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Civil penalty. 228.21 Section 228.21..., DEPARTMENT OF TRANSPORTATION HOURS OF SERVICE OF RAILROAD EMPLOYEES Records and Reporting § 228.21 Civil... requirement is subject to a civil penalty of at least $650 and not more than $25,000 per violation,...

  19. 7 CFR 1726.21 - New materials.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false New materials. 1726.21 Section 1726.21 Agriculture... ELECTRIC SYSTEM CONSTRUCTION POLICIES AND PROCEDURES General § 1726.21 New materials. The borrower shall purchase only new materials and equipment unless otherwise approved by RUS, on a case by case basis,...

  20. 21 CFR 1316.02 - Definitions.

    Science.gov (United States)

    2010-04-01

    ...; 21 U.S.C. 801) and/or the Controlled Substances Import and Export Act (84 Stat. 1285; 21 U.S.C. 951... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Definitions. 1316.02 Section 1316.02 Food and... PROCEDURES Administrative Inspections § 1316.02 Definitions. As used in this subpart, the following...

  1. 29 CFR 510.21 - SIC codes.

    Science.gov (United States)

    2010-07-01

    ... reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR... 29 Labor 3 2010-07-01 2010-07-01 false SIC codes. 510.21 Section 510.21 Labor Regulations Relating... Classification of Industries § 510.21 SIC codes. (a) The Conference Report specifically cites Puerto...

  2. 28 CFR 524.21 - Definitions.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Definitions. 524.21 Section 524.21 Judicial Administration BUREAU OF PRISONS, DEPARTMENT OF JUSTICE INMATE ADMISSION, CLASSIFICATION, AND TRANSFER CLASSIFICATION OF INMATES Youth Corrections Act (YCA) Programs § 524.21 Definitions. (a) YCA inmate: An inmate sentenced under provision of...

  3. 17 CFR 2.1 - Description.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Description. 2.1 Section 2.1 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION OFFICIAL SEAL § 2.1 Description... Futures Trading Commission has adopted an official seal (the “Seal”), the description of which is...

  4. 28 CFR 71.21 - Discovery.

    Science.gov (United States)

    2010-07-01

    ... REMEDIES ACT OF 1986 Implementation for Actions Initiated by the Department of Justice § 71.21 Discovery. (a) The following types of discovery are authorized: (1) Requests for production of documents for... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Discovery. 71.21 Section 71.21...

  5. 22 CFR 521.21 - Discovery.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Discovery. 521.21 Section 521.21 Foreign Relations BROADCASTING BOARD OF GOVERNORS IMPLEMENTATION OF THE PROGRAM FRAUD CIVIL REMEDIES ACT § 521.21 Discovery. (a) The following types of discovery are authorized: (1) Requests for production of documents...

  6. 31 CFR 16.21 - Discovery.

    Science.gov (United States)

    2010-07-01

    ... FRAUD CIVIL REMEDIES ACT OF 1986 § 16.21 Discovery. (a) The following types of discovery are authorized... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Discovery. 16.21 Section 16.21 Money... to require the creation of a document. (c) Unless mutually agreed to by the parties, discovery...

  7. 20 CFR 355.21 - Discovery.

    Science.gov (United States)

    2010-04-01

    ... UNDER THE PROGRAM FRAUD CIVIL REMEDIES ACT OF 1986 § 355.21 Discovery. (a) The following types of discovery are authorized: (1) Requests for production of documents for inspection and copying; (2) Requests... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Discovery. 355.21 Section 355.21...

  8. 42 CFR 21.33 - General service.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false General service. 21.33 Section 21.33 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES PERSONNEL COMMISSIONED OFFICERS Appointment § 21.33 General service. Officers shall be appointed only to general service and shall be...

  9. 42 CFR 409.21 - Nursing care.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Nursing care. 409.21 Section 409.21 Public Health... HOSPITAL INSURANCE BENEFITS Posthospital SNF Care § 409.21 Nursing care. (a) Basic rule. Medicare pays for nursing care as posthospital SNF care when provided by or under the supervision of a...

  10. 45 CFR 3.21 - Emergency vehicles.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Emergency vehicles. 3.21 Section 3.21 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CONDUCT OF PERSONS AND TRAFFIC ON THE NATIONAL INSTITUTES OF HEALTH FEDERAL ENCLAVE Traffic Regulations § 3.21 Emergency vehicles....

  11. 10 CFR 70.21 - Filing.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Filing. 70.21 Section 70.21 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) DOMESTIC LICENSING OF SPECIAL NUCLEAR MATERIAL License Applications § 70.21 Filing. (a... chapter. (e) Each application for a special nuclear material license, other than a license exempted...

  12. COP21 - A moment of truth for climate and sustainable development

    International Nuclear Information System (INIS)

    Time is running out to act on climate change, poverty eradication and sustainable development. These challenges cannot be met independently of each other. The task of COP21 is to send strong policy signals that determined climate action is needed and will not harm the economy. In fact, these actions will trigger multiple employment, health and human development benefits by aligning strengthened short-term economic growth with long-term sustainable development goals. It is challenging but possible to trigger the transformation toward low carbon futures and to increase the affordability of advanced technologies despite the current pressures on public budgets. The world is awash in liquidity. What is needed is to redirect the savings of households, pension funds, insurance schemes, and sovereign wealth funds towards long-term and low-carbon investments. Sound regulatory frameworks and innovative financial mechanisms must be established to reduce the risks attached to potentially profitable low-carbon projects that are blocked by a combination of high up front costs and an uncertain environment, so as to attract private savings and institutional investors. COP 21 can provide critical policy hooks for step changes in economic and financial inter-mediation based on public guarantees for low carbon investments; an agreed social value of carbon mitigation activities could be incorporated into diverse low-carbon financial initiatives supporting Intended Nationally Determined Contributions (INDCs); strong and enforceable requirements for Measuring, Reporting and Verification (MRV) can ensure the environmental integrity and sustainability of the resulting investments. Such a framework can secure the transparency of voluntary commitments by countries, clubs of countries and non-state actors. If it can achieve these goals, the Paris Agreement can unleash a wave of investments into low-carbon development that responds to short-term economic and social challenges while supporting

  13. Boron nitride converted carbon fiber

    Energy Technology Data Exchange (ETDEWEB)

    Rousseas, Michael; Mickelson, William; Zettl, Alexander K.

    2016-04-05

    This disclosure provides systems, methods, and apparatus related to boron nitride converted carbon fiber. In one aspect, a method may include the operations of providing boron oxide and carbon fiber, heating the boron oxide to melt the boron oxide and heating the carbon fiber, mixing a nitrogen-containing gas with boron oxide vapor from molten boron oxide, and converting at least a portion of the carbon fiber to boron nitride.

  14. Templated Growth of Carbon Nanotubes

    Science.gov (United States)

    Siochik Emilie J. (Inventor)

    2007-01-01

    A method of growing carbon nanotubes uses a synthesized mesoporous si lica template with approximately cylindrical pores being formed there in. The surfaces of the pores are coated with a carbon nanotube precu rsor, and the template with the surfaces of the pores so-coated is th en heated until the carbon nanotube precursor in each pore is convert ed to a carbon nanotube.

  15. Carbon balance in Mediterranean ecosystems

    OpenAIRE

    Correia, Alexandra Cristina Pires

    2013-01-01

    Forests play an important role in climate change mitigation as they sequester and store carbon dioxide (CO2) from the atmosphere. The aim of this thesis was to investigate forest carbon balance in its main compartments: tress, understory and soils. We present methods to estimate carbon stock in biomass of stone pine stands in south Portugal. Allometric models, as well as conversion and expansion factors were presented allowing the quantification of stand carbon stocks irrespect...

  16. Microwave Properties of Carbon Nanotubes Grown by Pyrolysis of Ethanol on Nickel Catalyst

    Directory of Open Access Journals (Sweden)

    V.V. Rodionov

    2014-07-01

    Full Text Available The efficiency of carbon nanotubes produced by CVD-method on a nickel catalyst at a protection from microwave radiation is shown. These data are confirmed by scanning electron microscopy, energy dispersive X-ray analysis and spectral analysis of the microwave radiation in the frequency range 26-40 GHz. The observed value of the transmission coefficient S21, up to – 42.7 dB, is in agreement with considered possible absorption mechanisms of electromagnetic wave energy in carbon nanoscale systems “CNT-nickel nanoparticles”. The application of carbon powder materials in shielding of electromagnetic radiation has been theoretically justified.

  17. Carbon fluxes in an acid rain impacted boreal headwater catchment

    Science.gov (United States)

    Marx, Anne; Hintze, Simone; Jankovec, Jakub; Sanda, Martin; Dusek, Jaromir; Vogel, Tomas; van Geldern, Robert; Barth, Johannes A. C.

    2016-04-01

    Terrestrial carbon export via inland aquatic systems is a key process in the budget of the global carbon cycle. This includes loss of carbon to the atmosphere via gas evasion from rivers or reservoirs as well as carbon fixation in freshwater sediments. Headwater streams are the first endmembers of the transition of carbon between soils, groundwater and surface waters and the atmosphere. In order to quantify these processes the experimental catchment Uhlirska (1.78 km2) located in the northern Czech Republic was studied. Dissolved inorganic, dissolved organic and particulate organic carbon (DIC, DOC, POC) concentrations and isotopes were analyzed in ground-, soil -and stream waters between 2014 and 2015. In addition, carbon dioxide degassing was quantified via a stable isotope modelling approach. Results show a discharge-weighted total carbon export of 31.99 g C m‑2 yr‑1 of which CO2 degassing accounts 79 %. Carbon isotope ratios (δ13C) of DIC, DOC, and POC (in ‰ VPDB) ranged from -26.6 to -12.4 ‰ from -29.4 to -22.7 ‰ and from -30.6 to -26.6 ‰ respectively. The mean values for DIC are -21.8 ±3.8 ‰ -23.6 ±0.9 ‰ and -19.5 ±3.0 ‰ for soil, shallow ground and surface water compartments. For DOC, these compartments have mean values of -27.1 ±0.3 ‰ -27.0 ±0.8 ‰ and -27.4 ±0.7 ‰Ṁean POC value of shallow groundwaters and surface waters are -28.8 ±0.8 ‰ and -29.3 ±0.5 ‰ respectively. These isotope ranges indicate little turnover of organic material and predominant silicate weathering. The degassing of CO2 caused an enrichment of the δ13C-DIC values of up to 6.8 ‰ between a catchment gauge and the catchment outlet over a distance of 866 m. In addition, the Uhlirska catchment has only negligible natural sources of sulphate, yet SO42‑ accounts for 21 % of major stream water ions. This is most likely a remainder from acid rain impacts in the area.

  18. Apparatus for producing carbon-coated nanoparticles and carbon nanospheres

    Science.gov (United States)

    Perry, W. Lee; Weigle, John C.; Phillips, Jonathan

    2015-10-20

    An apparatus for producing carbon-coated nano- or micron-scale particles comprising a container for entraining particles in an aerosol gas, providing an inlet for carbon-containing gas, providing an inlet for plasma gas, a proximate torch for mixing the aerosol gas, the carbon-containing gas, and the plasma gas, bombarding the mixed gases with microwaves, and providing a collection device for gathering the resulting carbon-coated nano- or micron-scale particles. Also disclosed is a method and apparatus for making hollow carbon nano- or micro-scale spheres.

  19. Designing carbon markets, Part II: Carbon markets in space

    International Nuclear Information System (INIS)

    This paper analyses the design of carbon markets in space (i.e., geographically). It is part of a twin set of papers that, starting from first principles, ask what an optimal global carbon market would look like by around 2030. Our focus is on firm-level cap-and-trade systems, although much of what we say would also apply to government-level trading and carbon offset schemes. We examine the 'first principles' of spatial design to maximise flexibility and to minimise costs, including key design issues in linking national and regional carbon markets together to create a global carbon market.

  20. Green Carbon : The role of natural forests in carbon storage

    OpenAIRE

    Keith, Heather; Lindenmayer, David B; Mackey, Brendan; Berry, Sandra L.

    2008-01-01

    The colour of carbon matters. Green carbon is the carbon stored in the plants and soil of natural ecosystems and is a vital part of the global carbon cycle. This report is the first in a series that examines the role of natural forests in the storage of carbon, the impacts of human land use activities, and the implications for climate change policy nationally and internationally. REDD (“reducing emissions from deforestation and degradation”) is now part of the agenda for the “Bali Action Plan...

  1. Wool Research Makes Carbon Headway

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    A collective of woolgrowers, scientists and carbon specialists the Wool Carbon Alliance (WCA) has reviewed the latest research role in the natural carbon cycle, from woolgrowing properties around the globe known as on wool's to homes around the globe .

  2. Carbon dioxide as a carbon source in organic transformation: carbon-carbon bond forming reactions by transition-metal catalysts.

    OpenAIRE

    Tsuji, Yasushi; Fujihara, Tetsuaki

    2012-01-01

    Recent carbon-carbon bond forming reactions of carbon dioxide with alkenes, alkynes, dienes, aryl zinc compounds, aryl boronic esters, aryl halides, and arenes having acidic C-H bonds are reviewed in which transition-metal catalysts play an important role.

  3. Carbon nanotube junctions and devices

    NARCIS (Netherlands)

    Postma, H.W.Ch.

    2001-01-01

    In this thesis Postma presents transport experiments performed on individual single-wall carbon nanotubes. Carbon nanotubes are molecules entirely made of carbon atoms. The electronic properties are determined by the exact symmetry of the nanotube lattice, resulting in either metallic or semiconduct

  4. Guideposts for Low Carbon Finance

    International Nuclear Information System (INIS)

    The author proposes four guideposts for efficient low carbon finance: remove subsidies for high-carbon technologies, improve the cost-effectiveness of low-carbon subsidies, encourage private sector innovation and maintain transparent public policy tools that support cost-benefit accounting

  5. CARBON IN FORESTS: QUALITY MATTERS

    Science.gov (United States)

    The nature of carbon in forests is discussed from the perspective of carbon sequestration and global climate change. Carbon inventories, specifically in the area of land use and forestry are reviewed for the Pacific Northwest. Areas vulnerable to climate change with respect to ca...

  6. Carbon Sequestration in Agricultural Soils

    OpenAIRE

    World Bank

    2009-01-01

    The purpose of this report is to improve the knowledge base for facilitating investments in land management technologies that sequester soil organic carbon. While there are many studies on soil carbon sequestration, there is no single unifying volume that synthesizes knowledge on the impact of different land management practices on soil carbon sequestration rates across the world. A meta-a...

  7. Low Carbon Development of Hainan

    Science.gov (United States)

    Yi, Feng; Kun, Zhang

    With the construction of Hainan international tourism island rising to a national strategy level, the green growth pattern based on low carbon objectives will become a significant part in the development of Hainan's economy. In this paper, low carbon electric power system and differentiation service will be discussed, and some opinions were brought up to have a good impact on Hainan's low carbon development.

  8. 21 CFR 878.4810 - Laser surgical instrument for use in general and plastic surgery and in dermatology.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Laser surgical instrument for use in general and... Surgical Devices § 878.4810 Laser surgical instrument for use in general and plastic surgery and in dermatology. (a) Identification. (1) A carbon dioxide laser for use in general surgery and in dermatology is...

  9. Accelerated carbonation of brucite in mine tailings for carbon sequestration.

    Science.gov (United States)

    Harrison, Anna L; Power, Ian M; Dipple, Gregory M

    2013-01-01

    Atmospheric CO(2) is sequestered within ultramafic mine tailings via carbonation of Mg-bearing minerals. The rate of carbon sequestration at some mine sites appears to be limited by the rate of CO(2) supply. If carbonation of bulk tailings were accelerated, large mines may have the capacity to sequester millions of tonnes of CO(2) annually, offsetting mine emissions. The effect of supplying elevated partial pressures of CO(2) (pCO(2)) at 1 atm total pressure, on the carbonation rate of brucite [Mg(OH)(2)], a tailings mineral, was investigated experimentally with conditions emulating those at Mount Keith Nickel Mine (MKM), Western Australia. Brucite was carbonated to form nesquehonite [MgCO(3) · 3H(2)O] at a rate that increased linearly with pCO(2). Geochemical modeling indicated that HCO(3)(-) promoted dissolution accelerated brucite carbonation. Isotopic and aqueous chemistry data indicated that equilibrium between CO(2) in the gas and aqueous phases was not attained during carbonation, yet nesquehonite precipitation occurred at equilibrium. This implies CO(2) uptake into solution remains rate-limiting for brucite carbonation at elevated pCO(2), providing potential for further acceleration. Accelerated brucite carbonation at MKM offers the potential to offset annual mine emissions by ~22-57%. Recognition of mechanisms for brucite carbonation will guide ongoing work to accelerate Mg-silicate carbonation in tailings. PMID:22770473

  10. Carbon dioxide conversion over carbon-based nanocatalysts.

    Science.gov (United States)

    Khavarian, Mehrnoush; Chai, Siang-Piao; Mohamed, Abdul Rahman

    2013-07-01

    The utilization of carbon dioxide for the production of valuable chemicals via catalysts is one of the efficient ways to mitigate the greenhouse gases in the atmosphere. It is known that the carbon dioxide conversion and product yields are still low even if the reaction is operated at high pressure and temperature. The carbon dioxide utilization and conversion provides many challenges in exploring new concepts and opportunities for development of unique catalysts for the purpose of activating the carbon dioxide molecules. In this paper, the role of carbon-based nanocatalysts in the hydrogenation of carbon dioxide and direct synthesis of dimethyl carbonate from carbon dioxide and methanol are reviewed. The current catalytic results obtained with different carbon-based nanocatalysts systems are presented and how these materials contribute to the carbon dioxide conversion is explained. In addition, different strategies and preparation methods of nanometallic catalysts on various carbon supports are described to optimize the dispersion of metal nanoparticles and catalytic activity. PMID:23901504

  11. Postinfectious encephalitis (21 cases appended)

    Institute of Scientific and Technical Information of China (English)

    丰宏林; 孙伟; 王文秋; 王德生

    2003-01-01

    Objective To report 21 cases of postinfectious encephatitis according to ICD-NA, postinfectious/parainfectious encephalitis is an independent disease.Methods Using the uniform criteria provided by The Council of State and Territorial Epidemiologists (CSTE) and Centers for Disease Control and Prevention (CDC), we diagnosed postinfectious encephalitis among patients admitted to The First Hospital of Harbin Medical University and analyzed the characteristics of these cases. Results All the patients had histories of preceding infection, and most of them suffered from mental and conscious disorders. Adrenocortical hormone was effective.Conclusions Postinfectious encephalitis is an independent disease. According to this article, about 10% patients with encephalitis admitted to our hospital are postinfectious.

  12. Regulation of p21ras activity

    DEFF Research Database (Denmark)

    Lowy, D R; Zhang, K; DeClue, J E;

    1992-01-01

    The ras genes encode GTP/GDP-binding proteins that participate in mediating mitogenic signals from membrane tyrosine kinases to downstream targets. The activity of p21ras is determined by the concentration of GTP-p21ras, which is tightly regulated by a complex array of positive and negative control...... mechanisms. GAP and NF1 can negatively regulate p21ras activity by stimulating hydrolysis of GTP bound to p21ras. Other cellular factors can positively regulate p21ras by stimulating GDP/GTP exchange....

  13. Erosion of soil organic carbon: implications for carbon sequestration

    Science.gov (United States)

    Van Oost, Kristof; Van Hemelryck, Hendrik; Harden, Jennifer W.

    2009-01-01

    Agricultural activities have substantially increased rates of soil erosion and deposition, and these processes have a significant impact on carbon (C) mineralization and burial. Here, we present a synthesis of erosion effects on carbon dynamics and discuss the implications of soil erosion for carbon sequestration strategies. We demonstrate that for a range of data-based parameters from the literature, soil erosion results in increased C storage onto land, an effect that is heterogeneous on the landscape and is variable on various timescales. We argue that the magnitude of the erosion term and soil carbon residence time, both strongly influenced by soil management, largely control the strength of the erosion-induced sink. In order to evaluate fully the effects of soil management strategies that promote carbon sequestration, a full carbon account must be made that considers the impact of erosion-enhanced disequilibrium between carbon inputs and decomposition, including effects on net primary productivity and decomposition rates.

  14. Tc-99 Adsorption on Selected Activated Carbons - Batch Testing Results

    Energy Technology Data Exchange (ETDEWEB)

    Mattigod, Shas V.; Wellman, Dawn M.; Golovich, Elizabeth C.; Cordova, Elsa A.; Smith, Ronald M.

    2010-12-01

    conducted to ascertain the effects of changing pH showed that at pH values of 6.5 and 7.5, no significant differences existed in Tc-adsorption performance for three of the carbons, but the fourth carbon performed better at pH 7.5. When the pH was increased to 8.5, a slight decline in performance was observed for all carbons. Tests conducted to ascertain the temperature effect on Tc-99 adsorption indicated that at 21 ºC, 27 ºC, and 32 ºC there were no significant differences in Tc-99 adsorption for three of the carbons. The fourth carbon showed a noticeable decline in Tc-99 adsorption performance with increasing temperature. The presence of volatile organic compounds (VOCs) in the source water did not significantly affect Tc-99 adsorption on either of two carbons tested. Technetium-99 adsorption differed by less than 15% with or without VOCs present in the test water, indicating that Tc-99 adsorption would not be significantly affected if VOCs were removed from the water prior to contact with carbon.

  15. [Variation characteristics of soil carbon sequestration under long-term different fertilization in red paddy soil].

    Science.gov (United States)

    Huang, Jing; Zhang, Yang-zhu; Gao, Ju-sheng; Zhang, Wen-ju; Liu, Shu-jun

    2015-11-01

    The objective of this study was to clarify the changes of soil organic carbon (SOC) content, the saturation capacity of soil carbon sequestration and its cooperation with carbon input (crop source and organic fertilizer source carbon) under long-term (1982-2012) different fertilization in red paddy soil. The results showed that fertilization could increase SOC content. The SOC content of all the fertilization treatments demonstrated a trend of stabilization after applying fertilizer for 30 years. The SOC content in the treatments applying organic manure with mineral fertilizers was between 21.02 and 21.24 g · kg(-1), and the increase rate ranged from 0.41 to 0.59 g · kg(-1) · a(-1). The SOC content in the treatments applying mineral fertilizers only was 15.48 g · kg(-1). The average soil carbon sequestration in the treatments that applied organic manure with mineral fertilizers ranged from 43.61 to 48.43 t C · hm(-2), and the average SOC storage over the years in these treatments was significantly greater than those applying mineral fertilizers only. There was an exponentially positive correlation between C sequestration efficiency and annual average organic C input. It must input exogenous organic carbon at least at 0. 12 t C · hm(-2) · a(-1) to maintain the balance of soil organic carbon under the experimental conditions. PMID:26915193

  16. [Variation characteristics of soil carbon sequestration under long-term different fertilization in red paddy soil].

    Science.gov (United States)

    Huang, Jing; Zhang, Yang-zhu; Gao, Ju-sheng; Zhang, Wen-ju; Liu, Shu-jun

    2015-11-01

    The objective of this study was to clarify the changes of soil organic carbon (SOC) content, the saturation capacity of soil carbon sequestration and its cooperation with carbon input (crop source and organic fertilizer source carbon) under long-term (1982-2012) different fertilization in red paddy soil. The results showed that fertilization could increase SOC content. The SOC content of all the fertilization treatments demonstrated a trend of stabilization after applying fertilizer for 30 years. The SOC content in the treatments applying organic manure with mineral fertilizers was between 21.02 and 21.24 g · kg(-1), and the increase rate ranged from 0.41 to 0.59 g · kg(-1) · a(-1). The SOC content in the treatments applying mineral fertilizers only was 15.48 g · kg(-1). The average soil carbon sequestration in the treatments that applied organic manure with mineral fertilizers ranged from 43.61 to 48.43 t C · hm(-2), and the average SOC storage over the years in these treatments was significantly greater than those applying mineral fertilizers only. There was an exponentially positive correlation between C sequestration efficiency and annual average organic C input. It must input exogenous organic carbon at least at 0. 12 t C · hm(-2) · a(-1) to maintain the balance of soil organic carbon under the experimental conditions.

  17. The mechanical properties measurement of multiwall carbon nanotube reinforced nanocrystalline aluminum matrix composite

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Manjula, E-mail: manjula.physics@gmail.com; Pal, Hemant; Sharma, Vimal [Department of Physics, NIT Hamirpur (HP) - 177005 (India)

    2015-05-15

    Nanocrystalline aluminum matrix composite containing carbon nanotubes were fabricated using physical mixing method followed by cold pressing. The microstructure of the composite has been investigated using X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy techniques. These studies revealed that the carbon nanotubes were homogeneously dispersed throughout the metal matrix. The consolidated samples were pressureless sintered in inert atmosphere to further actuate a strong interface between carbon nanotubes and aluminum matrix. The nanoindentation tests carried out on considered samples showed that with the addition of 0.5 wt% carbon nanotubes, the hardness and elastic modulus of the aluminum matrix increased by 21.2 % and 2 % repectively. The scratch tests revealed a decrease in the friction coefficient of the carbon nanotubes reinforced composite due to the presence of lubricating interfacial layer. The prepared composites were promising entities to be used in the field of sporting goods, construction materials and automobile industries.

  18. Interannual stability of organic to inorganic carbon production on a coral atoll

    Science.gov (United States)

    Kwiatkowski, Lester; Albright, Rebecca; Hosfelt, Jessica; Nebuchina, Yana; Ninokawa, Aaron; Rivlin, Tanya; Sesboüé, Marine; Wolfe, Kennedy; Caldeira, Ken

    2016-04-01

    Ocean acidification has the potential to adversely affect marine calcifying organisms, with substantial ocean ecosystem impacts projected over the 21st century. Characterizing the in situ sensitivity of calcifying ecosystems to natural variability in carbonate chemistry may improve our understanding of the long-term impacts of ocean acidification. We explore the potential for intensive temporal sampling to isolate the influence of carbonate chemistry on community calcification rates of a coral reef and compare the ratio of organic to inorganic carbon production to previous studies at the same location. Even with intensive temporal sampling, community calcification displays only a weak dependence on carbonate chemistry variability. However, across three years of sampling, the ratio of organic to inorganic carbon production is highly consistent. Although further work is required to quantify the spatial variability associated with such ratios, this suggests that these measurements have the potential to indicate the response of coral reefs to ongoing disturbance, ocean acidification, and climate change.

  19. Transformation of acetate carbon into carbohydrate and amino acid metabilites during decomposition in soil

    DEFF Research Database (Denmark)

    Sørensen, Lasse Holst; Paul, E. A.

    1971-01-01

    Carbon-14-labelled acetate was added to a heavy clay soil of pH 7.6 to study the transformation of acetate carbon into carbohydrate and amino acid metabolites during decomposition. The acetate was totally metabolized after 6 days of incubation at 25°C when 70% of the labelled carbon had been...... evolved as CO2. Maximum incorporation of trace-C into the various organic fractions was observed after 4 days when 19% of residual, labelled carbon in the soil was located in carbohydrates, 29 % in amino acids and 21 % in the insoluble residue of the soil. The curves showing the amounts of labelled carbon...... located in carbohydrates and amino acid metabolites show a curvilinear form during the first 30 days of incubation, indicating a variety of chemical compounds decaying at different rates. After this time, the decay curves became straight lines indicating a greater homogeneity of the metabolites. After 200...

  20. Carbon stocks of intact mangroves and carbon emissions arising from their conversion in the Dominican Republic.

    Science.gov (United States)

    Kauffman, J Boone; Heider, Chris; Norfolk, Jennifer; Payton, Frederick

    2014-04-01

    Mangroves are recognized to possess a variety of ecosystem services including high rates of carbon sequestration and storage. Deforestation and conversion of these ecosystems continue to be high and have been predicted to result in significant carbon emissions to the atmosphere. Yet few studies have quantified the carbon stocks or losses associated with conversion of these ecosystems. In this study we quantified the ecosystem carbon stocks of three common mangrove types of the Caribbean as well as those of abandoned shrimp ponds in areas formerly occupied by mangrove-a common land-use conversion of mangroves throughout the world. In the mangroves of the Montecristi Province in Northwest Dominican Republic we found C stocks ranged from 706 to 1131 Mg/ha. The medium-statured mangroves (3-10 m in height) had the highest C stocks while the tall (> 10 m) mangroves had the lowest ecosystem carbon storage. Carbon stocks of the low mangrove (shrub) type (mangroves. Using a stock-change approach, the potential emissions from the conversion of mangroves to shrimp ponds ranged from 2244 to 3799 Mg CO2e/ha (CO2 equivalents). This is among the largest measured C emissions from land use in the tropics. The 6260 ha of mangroves and converted mangroves in the Montecristi Province are estimated to contain 3,841,490 Mg of C. Mangroves represented 76% of this area but currently store 97% of the carbon in this coastal wetland (3,696,722 Mg C). Converted lands store only 4% of the total ecosystem C (144,778 Mg C) while they comprised 24% of the area. By these metrics the replacement of mangroves with shrimp and salt ponds has resulted in estimated emissions from this region totaling 3.8 million Mg CO2e or approximately 21% of the total C prior to conversion. Given the high C stocks of mangroves, the high emissions from their conversion, and the other important functions and services they provide, their inclusion in climate-change mitigation strategies is warranted.

  1. Organic Carbon Isotope Geochemistry of the Neoproterozoic Doushantuo Formation, South China

    Institute of Scientific and Technical Information of China (English)

    GUO Qingjun; LIU Congqiang; Harald STRAUSS; Tatiana GOLDBERG; ZHU Maoyan; PI Daohui; WANG Jian

    2006-01-01

    The Neoproterozoic Doushantuo Formation on the Yangtze Platform, South China,documents a sedimentary succession with different sedimentary facies from carbonate platform to slope and to deep sea basin, and hosts one of the world-class phosphorite deposits. In these strata,exquisitely preserved fossils have been discovered: the Weng'an biota. This study presents carbon isotope geochemistry which is associated paired carbonate and organic matter from the Weng'an section of a carbonate platform (shelf of the Yangtze Platform, Guizhou Province) from the Songtao section and Nanming section of a transition belt (slope of the Yangtze Platform, Guizhou Province) and from the Yanwutan section (basin area of the Yangtze Platform, Hunan Province). Environmental variations and bio-events on the Yangtze Platform during the Late Neoproterozoic and their causal relationship are discussed. Negative carbon isotope values for carbonate and organic carbon (mean δ13Corg = -35.0%) from the uppermost Nantuo Formation are followed by an overall increase in δ13C up-section. Carbon isotope values vary between -9.9% and 3.6% for carbonate and between -35.6% and -21.5% for organic carbon, respectively. Heavier δ13Ccarb values suggest an increase in organic carbon burial, possibly related to increasing productivity (such as the Weng'an biota). The δ13C values of the sediments from the Doushantuo Formation decreased from the platform via the slope to basin,reflecting a reduced environment with minor dissolved inorganic carbon possibly due to a lower primary productivity. It is deduced that the classical upwelling process, the stratification structure and the hydrothermal eruption are principally important mechanisms to interpret the carbon isotopic compositions of the sediments from the Doushantuo Formation.

  2. Carbon dioxide dangers demonstration model

    Science.gov (United States)

    Venezky, Dina; Wessells, Stephen

    2010-01-01

    Carbon dioxide is a dangerous volcanic gas. When carbon dioxide seeps from the ground, it normally mixes with the air and dissipates rapidly. However, because carbon dioxide gas is heavier than air, it can collect in snowbanks, depressions, and poorly ventilated enclosures posing a potential danger to people and other living things. In this experiment we show how carbon dioxide gas displaces oxygen as it collects in low-lying areas. When carbon dioxide, created by mixing vinegar and baking soda, is added to a bowl with candles of different heights, the flames are extinguished as if by magic.

  3. Decadally cycling soil carbon is more sensitive to warming than faster-cycling soil carbon.

    Science.gov (United States)

    Lin, Junjie; Zhu, Biao; Cheng, Weixin

    2015-12-01

    The response of soil organic carbon (SOC) pools to globally rising surface temperature crucially determines the feedback between climate change and the global carbon cycle. However, there is a lack of studies investigating the temperature sensitivity of decomposition for decadally cycling SOC which is the main component of total soil carbon stock and the most relevant to global change. We tackled this issue using two decadally (13) C-labeled soils and a much improved measuring system in a long-term incubation experiment. Results indicated that the temperature sensitivity of decomposition for decadally cycling SOC (>23 years in one soil and >55 years in the other soil) was significantly greater than that for faster-cycling SOC (<23 or 55 years) or for the entire SOC stock. Moreover, decadally cycling SOC contributed substantially (35-59%) to the total CO2 loss during the 360-day incubation. Overall, these results indicate that the decomposition of decadally cycling SOC is highly sensitive to temperature change, which will likely make this large SOC stock vulnerable to loss by global warming in the 21st century and beyond.

  4. CCL21/IL21-armed oncolytic adenovirus enhances antitumor activity against TERT-positive tumor cells.

    Science.gov (United States)

    Li, Yang; Li, Yi-Fei; Si, Chong-Zhan; Zhu, Yu-Hui; Jin, Yan; Zhu, Tong-Tong; Liu, Ming-Yuan; Liu, Guang-Yao

    2016-07-15

    Multigene-armed oncolytic adenoviruses are capable of efficiently generating a productive antitumor immune response. The chemokine (C-C motif) ligand 21 (CCL21) binds to CCR7 on naïve T cells and dendritic cells (DCs) to promote their chemoattraction to the tumor and resultant antitumor activity. Interleukin 21 (IL21) promotes survival of naïve T cells while maintaining their CCR7 surface expression, which increases their capacity to transmigrate in response to CCL21 chemoattraction. IL21 is also involved in NK cell differentiation and B cell activation and proliferation. The generation of effective antitumor immune responses is a complex process dependent upon coordinated interactions of various subsets of effector cells. Using the AdEasy system, we aimed to construct an oncolytic adenovirus co-expressing CCL21 and IL21 that could selectively replicate in TERTp-positive tumor cells (Ad-CCL21-IL21 virus). The E1A promoter of these oncolytic adenoviruses was replaced by telomerase reverse transcriptase promoter (TERTp). Ad-CCL21-IL21 was constructed from three plasmids, pGTE-IL21, pShuttle-CMV-CCL21 and AdEasy-1 and was homologously recombined and propagated in the Escherichia coli strain BJ5183 and the packaging cell line HEK-293, respectively. Our results showed that our targeted and armed oncolytic adenoviruses Ad-CCL21-IL21 can induce apoptosis in TERTp-positive tumor cells to give rise to viral propagation, in a dose-dependent manner. Importantly, we confirm that these modified oncolytic adenoviruses do not replicate efficiently in normal cells even under high viral loads. Additionally, we investigate the role of Ad-CCL21-IL21 in inducing antitumor activity and tumor specific cytotoxicity of CTLs in vitro. This study suggests that Ad-CCL21-IL21 is a promising targeted tumor-specific oncolytic adenovirus. PMID:27157859

  5. 40 CFR 721.10012 - Manganate (MnO21-), calcium (2:1).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Manganate (MnO21-), calcium (2:1). 721... Substances § 721.10012 Manganate (MnO21-), calcium (2:1). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as manganate (MnO2 1 -), calcium (2:1) (PMN...

  6. VISION 21 SYSTEMS ANALYSIS METHODOLOGIES

    Energy Technology Data Exchange (ETDEWEB)

    G.S. Samuelsen; A. Rao; F. Robson; B. Washom

    2003-08-11

    Under the sponsorship of the U.S. Department of Energy/National Energy Technology Laboratory, a multi-disciplinary team led by the Advanced Power and Energy Program of the University of California at Irvine is defining the system engineering issues associated with the integration of key components and subsystems into power plant systems that meet performance and emission goals of the Vision 21 program. The study efforts have narrowed down the myriad of fuel processing, power generation, and emission control technologies to selected scenarios that identify those combinations having the potential to achieve the Vision 21 program goals of high efficiency and minimized environmental impact while using fossil fuels. The technology levels considered are based on projected technical and manufacturing advances being made in industry and on advances identified in current and future government supported research. Included in these advanced systems are solid oxide fuel cells and advanced cycle gas turbines. The results of this investigation will serve as a guide for the U. S. Department of Energy in identifying the research areas and technologies that warrant further support.

  7. DFT Thermodynamic Research of the Pyrolysis Mechanism of the Carbon Matrix Precursor Toluene for Carbon Material

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on the experiments, the standard enthalpy △H of the possible pyrolysis reactions of the carbon matrix precursor toluene was investigated by means of DFT method UB3LYP/ 3-21G* (based on semi-empirical method UAM1 and ab initio method UHF/3-21G* ). The com putation results with UB3LYP/3-21G* coincide with the experimental values well. Then, the mechanism for all types of the pyrolysis reactions of toluene was studied by UB3LYP/3-2lG*. The geometries of the reactant and the product radicals were optimized, meanwhile, the standard thermodynamic parameters of the pyrolysis reaction at different temperatures (298, 773, 843, 963 and 1 073 K) were calculated. The thermodynamic computation result shows that when the pyrolysis temperature of toluene is lower than 963 K, the reaction path supported by thermody namics is that the C-H bond of the methyl on the benzene ring breaks and bitoluene form, while the temperature increases (about 1 073 K), the thermodynamic calculation result turns to sup port the reaction path producing phenyl radicals and methyl radicals. This mechanism is in accord with the experiments.

  8. Carbon Nanotube Biosensors

    Directory of Open Access Journals (Sweden)

    Carmen-Mihaela eTilmaciu

    2015-10-01

    Full Text Available Nanomaterials possess unique features which make them particularly attractive for biosensing applications. In particular Carbon Nanotubes (CNTs can serve as scaffolds for immobilization of biomolecules at their surface, and combine several exceptional physical, chemical, electrical and optical characteristics properties which make them one of the best suited materials for the transduction of signals associated with the recognition of analytes, metabolites or disease biomarkers. Here we provide a comprehensive review on these carbon nanostructures, in which we will describe their structural and physical properties, discuss functionalization and cellular uptake, biocompatibility and toxicity issues. We further review historical developments in the field of biosensors, and describe the different types of biosensors which have been developed over time, with specific focus on CNT-conjugates engineered for biosensing applications, and in particular detection of cancer biomarkers.

  9. Carbon Fiber Composites

    Science.gov (United States)

    1997-01-01

    HyComp(R), Inc. development a line of high temperature carbon fiber composite products to solve wear problems in the harsh environment of steel and aluminum mills. WearComp(R), self-lubricating composite wear liners and bushings, combines carbon graphite fibers with a polyimide binder. The binder, in conjunction with the fibers, provides the slippery surface, one that demands no lubrication, yet wears at a very slow rate. WearComp(R) typically lasts six to ten times longer than aluminum bronze. Unlike bronze, WearComp polishes the same surface and imparts a self-lube film for years of service. It is designed for continuous operation at temperatures of 550 degrees Fahrenheit and can operate under high compressive loads.

  10. Growing carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Yoshinori Ando

    2004-10-01

    Full Text Available The discovery of ‘fullerenes’ added a new dimension to the knowledge of carbon science1; and the subsequent discovery of ‘carbon nanotubes’ (CNTs, the elongated fullerene added a new dimension to the knowledge of technology2;. Today, ‘nanotechnology’ is a hot topic attracting scientists, industrialists, journalists, governments, and even the general public. Nanotechnology is the creation of functional materials, devices, and systems through control of matter on the nanometer scale and the exploitation of novel phenomena and properties of matter (physical, chemical, biological, electrical, etc. at that length scale. CNTs are supposed to be a key component of nanotechnology. Almost every week a new potential application of CNTs is identified, stimulating scientists to peep into this tiny tube with ever increasing curiosity.

  11. Carbon materials for supercapacitors

    Science.gov (United States)

    Gao, Yang

    As an important energy storage device, electrochemical supercapacitors or ultracapacitors fill the gap between conventional dielectric capacitors and batteries in terms of specific energy and power. Although supercapacitors have been used in electric vehicles, digital communication instruments, and pulsed lasers, further improvement of supercapacitor performance is highly needed to enhance the energy density without significantly losing the power density. Additionally, the conventional supercapacitors use rigid packages and liquid electrolytes, which limit applications in transparent and flexible electronics. To address these challenges, the research efforts in this dissertation mainly focused on: 1) improvement of the energy density of carbon nanoonions by chemical activation; 2) laser-assisted activation of carbon nanotubes for improved energy density; 3) fabrication of flexible solid-state supercapacitors based on nanocarbon and manganese dioxide (MnO2) hybrid electrodes; and 4) investigation of the electrochemical performance of graphene as transparent and flexible supercapacitor electrodes.

  12. Applications of Carbon Nanotubes

    Science.gov (United States)

    Ajayan, Pulickel M.; Zhou, Otto Z.

    Carbon nanotubes have attracted the fancy of many scientists worldwide. The small dimensions, strength and the remarkable physical properties of these structures make them a very unique material with a whole range of promising applications. In this review we describe some of the important materials science applications of carbon nanotubes. Specifically we discuss the electronic and electrochemical applications of nanotubes, nanotubes as mechanical reinforcements in high performance composites, nanotube-based field emitters, and their use as nanoprobes in metrology and biological and chemical investigations, and as templates for the creation of other nanostructures. Electronic properties and device applications of nanotubes are treated elsewhere in the book. The challenges that ensue in realizing some of these applications are also discussed from the point of view of manufacturing, processing, and cost considerations.

  13. Carbon neutron star atmospheres

    CERN Document Server

    Suleimanov, V F; Pavlov, G G; Werner, K

    2013-01-01

    The accuracy of measuring the basic parameters of neutron stars is limited in particular by uncertainties in chemical composition of their atmospheres. For example, atmospheres of thermally - emitting neutron stars in supernova remnants might have exotic chemical compositions, and for one of them, the neutron star in CasA, a pure carbon atmosphere has recently been suggested by Ho & Heinke (2009). To test such a composition for other similar sources, a publicly available detailed grid of carbon model atmosphere spectra is needed. We have computed such a grid using the standard LTE approximation and assuming that the magnetic field does not exceed 10^8 G. The opacities and pressure ionization effects are calculated using the Opacity Project approach. We describe the properties of our models and investigate the impact of the adopted assumptions and approximations on the emergent spectra.

  14. Carbon Lorenz Curves

    Energy Technology Data Exchange (ETDEWEB)

    Groot, L. [Utrecht University, Utrecht School of Economics, Janskerkhof 12, 3512 BL Utrecht (Netherlands)

    2008-11-15

    The purpose of this paper is twofold. First, it exhibits that standard tools in the measurement of income inequality, such as the Lorenz curve and the Gini-index, can successfully be applied to the issues of inequality measurement of carbon emissions and the equity of abatement policies across countries. These tools allow policy-makers and the general public to grasp at a single glance the impact of conventional distribution rules such as equal caps or grandfathering, or more sophisticated ones, on the distribution of greenhouse gas emissions. Second, using the Samuelson rule for the optimal provision of a public good, the Pareto-optimal distribution of carbon emissions is compared with the distribution that follows if countries follow Nash-Cournot abatement strategies. It is shown that the Pareto-optimal distribution under the Samuelson rule can be approximated by the equal cap division, represented by the diagonal in the Lorenz curve diagram.

  15. Carbonation profiles in cement paste analyzed by neutron diffraction

    Science.gov (United States)

    Galan, I.; Sanchez, J.; Andrade, C.; Evans, A.

    2012-02-01

    The present work deals with the carbonation process in cement based materials such as concrete. In order to clarify the evolution of the two main phases involved in the process, portlandite and calcium carbonate as a function of depth, spatially resolved neutron diffraction experiments have been performed at SALSA diffractometer at ILL in carbonated cement paste samples. Specimens submitted to different carbonation processes, both natural and accelerated, have been analyzed with this non destructive technique. The evolution of the main diffraction peaks of portlandite and calcite has been followed by means of neutron diffraction patterns measured at different depths. The results indicate that, in specimens subjected to CO2 atmospheres for 24 and 48 hours, the amount of calcite increases from the centre of the specimen to the surface. In both type of specimens calcite is formed at all depths analyzed, with higher quantities for the ones submitted to the longest carbonation period. Regarding the evolution of portlandite in these specimens, it almost completely disappeared, with only a low amount of the phase constant throughout the sample. In specimens subjected to air in a closed chamber for 21 months, higher amounts of portlandite were observed throughout the sample and little increase of calcite in the outer part, pointing out a much less severe reaction. The absorption effects are characterized by measuring in perpendicular directions and an absorption coefficient is calculated for portlandite.

  16. Carbon and water vapor balance in a subtropical pine plantation

    Directory of Open Access Journals (Sweden)

    Posse G

    2016-10-01

    Full Text Available Afforestation has been proposed as an effective tool for protecting primary and/or secondary forests and for mitigating atmospheric CO2. However, the dynamics of primary productivity differs between plantations and natural forests. The objective of this work was to evaluate the potential for carbon storage of a commercial pine plantation by determining its carbon balance. Measurements started when trees were aged 6 and ended when they were older than 8 years. We measured CO2 and water vapor concentrations using the Eddy covariance method. Gross primary productivity in 2010 and 2011 was 4290 ± 473 g C m-2 and 4015 ± 485 g C m-2, respectively. Ecosystem respiration ranged between 7 and 20 g C m-2 d-1, reaching peaks in all Februaries. Of the 30 months monitored, the plantation acted as carbon source for 21 months and as carbon sink for 6 months, while values close to neutrality were obtained during 3 months. The positive balance representing CO2 loss by the system was most likely due to the cut branches left on the ground following pruning activities. The plantation was subjected to pruning in January and September 2008 and to sanitary pruning in October 2010. In all cases, cut branches were not removed but remained on the ground. Residue management seems to have a very important impact on carbon balance.

  17. Unburned Carbon from Samlaung Coal as Environmental Friendly Sorbent Material

    International Nuclear Information System (INIS)

    The increasing role of coal as a source of energy in the 21st century will demand enviromental and cost-effective strategies for the use of carbonaceous waste products from coal combustion. The carbonaceous in fly ash, unburned carbon (UC), is a potential precursor for the production of adsorbent carbons, since it has gone through a devolatization process while in the combustion, and therefore, only requires to be activated. This paper demonstrates the potential for converting UC from Samlaung coal to activated carbons. After heat activation at 970C, the UC sample was generated to activated carbons having microporous structure. This study concerns with adsorption behavior (decolourization and metal uptake) of UC from Samlaung coal. Batch tests and column tests were carried out. Adsorption isotherms has been obtained from these tests. Results show that the UC have equal or better adsorption capacity comparing with other activated carbons. It was found that heat treatment of Samlaung coal in the presence of air at 970C enhanced the adsorption capacity

  18. Carbon emissions from forest conversion by Kalimantan oil palm plantations

    Science.gov (United States)

    Carlson, Kimberly M.; Curran, Lisa M.; Asner, Gregory P.; Pittman, Alice Mcdonald; Trigg, Simon N.; Marion Adeney, J.

    2013-03-01

    Oil palm supplies >30% of world vegetable oil production. Plantation expansion is occurring throughout the tropics, predominantly in Indonesia, where forests with heterogeneous carbon stocks undergo high conversion rates. Quantifying oil palm's contribution to global carbon budgets therefore requires refined spatio-temporal assessments of land cover converted to plantations. Here, we report oil palm development across Kalimantan (538,346km2) from 1990 to 2010, and project expansion to 2020 within government-allocated leases. Using Landsat satellite analyses to discern multiple land covers, coupled with above- and below-ground carbon accounting, we develop the first high-resolution carbon flux estimates from Kalimantan plantations. From 1990 to 2010, 90% of lands converted to oil palm were forested (47% intact, 22% logged, 21% agroforests). By 2010, 87% of total oil palm area (31,640km2) occurred on mineral soils, and these plantations contributed 61-73% of 1990-2010 net oil palm emissions (0.020-0.024GtCyr-1). Although oil palm expanded 278% from 2000 to 2010, 79% of allocated leases remained undeveloped. By 2020, full lease development would convert 93,844km2 (~ 90% forested lands, including 41% intact forests). Oil palm would then occupy 34% of lowlands outside protected areas. Plantation expansion in Kalimantan alone is projected to contribute 18-22% (0.12-0.15GtCyr-1) of Indonesia's 2020 CO2-equivalent emissions. Allocated oil palm leases represent a critical yet undocumented source of deforestation and carbon emissions.

  19. Hybrid Aluminum Composite Materials Based on Carbon Nanostructures

    Directory of Open Access Journals (Sweden)

    Tatiana S. Koltsova

    2015-09-01

    Full Text Available We investigated formation of carbon nanofibers grown by chemical deposition (CVD method using an acetylene-hydrogen mixture on the surface of micron-sized aluminum powder particles. To obtain uniform distribution of the carbon nanostructures on the particles we deposited nickel catalyst on the surface by spraying from the aqueous solution of nickel nitrate. It was found that increasing the time of the synthesis lowers the rate of growth of carbon nanostructures due to the deactivation of the catalyst. The Raman spectroscopy measurements confirm the presence of disordered carbon corresponding to CNFs in the specimen. X-ray photoelectron spectroscopy showed the presence of aluminum carbide in the hot pressed samples. An aluminum composite material prepared using 1 wt.% CNFs obtained by uniaxial cold pressing and sintering showed 30% increase in the hardness compared to pure aluminum, whereas the composites prepared by hot pressing showed 80% increase in the hardness. Composite materials have satisfactory ductility. Thus, the aluminum based material reinforced with carbon nanostructures should be appropriate for creating high-strength and light compacts for aerospace and automotive applications and power engineering.DOI: http://dx.doi.org/10.5755/j01.ms.21.3.7355

  20. Pilot Study on Carbon-sand Filter for Sedimentation Effluent

    Directory of Open Access Journals (Sweden)

    Zhang Shuo

    2015-01-01

    Full Text Available The development of dual function of integrating with activated carbon adsorption and quartz sand filtration in the carbon-sand filter can collaboratively remove organic matters and turbidity and also protect the bio-security, and the pilot test is carried out to optimize the process parameters. The pilot test results show that the thickness of the filter materials is preferably 1,300mm of the activated carbon, 500mm of uniform quartz sand; filtration rate can be 8-12m/h; filter cycle is 24-48h; when the water temperature is 21°C to 29°C, the biofilm formation period in the carbon-sand filter is 15 to 20 days; removal of the organic matters and nitrogen runs through the entire filter bed, and the nitrite is mainly oxidized on the upper side; when the operation is mature, the layer of filter materials can form the biofilm and zoogloea, with the dual function of micro-biological degradation and activated carbon adsorption.

  1. Digital carbonate rock physics

    Science.gov (United States)

    Saenger, Erik H.; Vialle, Stephanie; Lebedev, Maxim; Uribe, David; Osorno, Maria; Duda, Mandy; Steeb, Holger

    2016-08-01

    Modern estimation of rock properties combines imaging with advanced numerical simulations, an approach known as digital rock physics (DRP). In this paper we suggest a specific segmentation procedure of X-ray micro-computed tomography data with two different resolutions in the µm range for two sets of carbonate rock samples. These carbonates were already characterized in detail in a previous laboratory study which we complement with nanoindentation experiments (for local elastic properties). In a first step a non-local mean filter is applied to the raw image data. We then apply different thresholds to identify pores and solid phases. Because of a non-neglectable amount of unresolved microporosity (micritic phase) we also define intermediate threshold values for distinct phases. Based on this segmentation we determine porosity-dependent values for effective P- and S-wave velocities as well as for the intrinsic permeability. For effective velocities we confirm an observed two-phase trend reported in another study using a different carbonate data set. As an upscaling approach we use this two-phase trend as an effective medium approach to estimate the porosity-dependent elastic properties of the micritic phase for the low-resolution images. The porosity measured in the laboratory is then used to predict the effective rock properties from the observed trends for a comparison with experimental data. The two-phase trend can be regarded as an upper bound for elastic properties; the use of the two-phase trend for low-resolution images led to a good estimate for a lower bound of effective elastic properties. Anisotropy is observed for some of the considered subvolumes, but seems to be insignificant for the analysed rocks at the DRP scale. Because of the complexity of carbonates we suggest using DRP as a complementary tool for rock characterization in addition to classical experimental methods.

  2. Carbon nanotube network varactor

    Science.gov (United States)

    Generalov, A. A.; Anoshkin, I. V.; Erdmanis, M.; Lioubtchenko, D. V.; Ovchinnikov, V.; Nasibulin, A. G.; Räisänen, A. V.

    2015-01-01

    Microelectromechanical system (MEMS) varactors based on a freestanding layer of single-walled carbon nanotube (SWCNT) films were designed, fabricated and tested. The freestanding SWCNT film was employed as a movable upper patch in the parallel plate capacitor of the MEMS. The measurements of the SWCNT varactors show very high tunability, nearly 100%, of the capacitance with a low actuation voltage of 10 V. The functionality of the varactor is improved by implementing a flexible nanocellulose aerogel filling.

  3. CARBON DIOXIDE FIXATION.

    Energy Technology Data Exchange (ETDEWEB)

    FUJITA,E.

    2000-01-12

    Solar carbon dioxide fixation offers the possibility of a renewable source of chemicals and fuels in the future. Its realization rests on future advances in the efficiency of solar energy collection and development of suitable catalysts for CO{sub 2} conversion. Recent achievements in the efficiency of solar energy conversion and in catalysis suggest that this approach holds a great deal of promise for contributing to future needs for fuels and chemicals.

  4. Accounting for carbon

    OpenAIRE

    Lovell, Heather; Sales de Aguiar, Thereza; Bebbington, Jan; Larrinaga-Gonzalez, Carlos; International Emissions Trading Association

    2010-01-01

    ACCA working in partnership with IETA This report reveals how large emitters in the European Emissions Trading Scheme (EU ETS) are accounting for emission allowances. The diversity of emission-allowance accounting practices being used in Europe shows carbon financial accounting to be in its formative stages - rules and practices are still unsettled. With this report, ACCA, in partnership with IETA, is opening up the debate to a wider international audience. Publisher PDF

  5. Improving Carbon Fixation Pathways

    OpenAIRE

    Ducat, Daniel C.; Silver, Pamela A

    2012-01-01

    A recent resurgence in basic and applied research on photosynthesis has been driven in part by recognition that fulfilling future food and energy requirements will necessitate improvements in crop carbon-fixation efficiencies. Photosynthesis in traditional terrestrial crops is being reexamined in light of molecular strategies employed by photosynthetic microbes to enhance the activity of the Calvin cycle. Synthetic biology is well-situated to provide original approaches for compartmentalizing...

  6. Amorphous carbon for photovoltaics

    Science.gov (United States)

    Risplendi, Francesca; Grossman, Jeffrey C.

    2015-03-01

    All-carbon solar cells have attracted attention as candidates for innovative photovoltaic devices. Carbon-based materials such as graphene, carbon nanotubes (CNT) and amorphous carbon (aC) have the potential to present physical properties comparable to those of silicon-based materials with advantages such as low cost and higher thermal stability.In particular a-C structures are promising systems in which both sp2 and sp3 hybridization coordination are present in different proportions depending on the specific density, providing the possibility of tuning their optoelectronic properties and achieving comparable sunlight absorption to aSi. In this work we employ density functional theory to design suitable device architectures, such as bulk heterojunctions (BHJ) or pn junctions, consisting of a-C as the active layer material.Regarding BHJ, we study interfaces between aC and C nanostructures (such as CNT and fullerene) to relate their optoelectronic properties to the stoichiometry of aC. We demonstrate that the energy alignment between the a-C mobility edges and the occupied and unoccupied states of the CNT or C60 can be widely tuned by varying the aC density to obtain a type II interface.To employ aC in pn junctions we analyze the p- and n-type doping of a-C focusingon an evaluation of the Fermi level and work function dependence on doping.Our results highlight promising features of aC as the active layer material of thin-film solar cells.

  7. Nongovernmental valorization of carbon dioxide

    International Nuclear Information System (INIS)

    Carbon dioxide (CO2) is considered the largest contributor to the greenhouse gas effect. Most attempts to manage the flow of CO2 or carbon into our environment involve reducing net emissions or sequestering the gas into long-lived sinks. Using CO2 as a chemical feedstock has a long history, but using it on scales that might impact the net emissions of CO2 into the atmosphere has not generally been considered seriously. There is also a growing interest in employing our natural biomes of carbon such as trees, vegetation, and soils as storage media. Some amelioration of the net carbon emissions into the atmosphere could be achieved by concomitant large withdrawals of carbon. This report surveys the potential and limitations in employing carbon as a resource for organic chemicals, fuels, inorganic materials, and in using the biome to manage carbon. The outlook for each of these opportunities is also described

  8. A Better Carbon Footprint Label

    DEFF Research Database (Denmark)

    Thøgersen, John; Nielsen, Kristian S.

    2016-01-01

    Based on insights from behavioral economics, it is suggested to extend carbon footprint labeling with information about relative performance, using the well-known “traffic light” color scheme to communicate relative performance. To test this proposition, the impact of a carbon footprint label......, participants saw the original Carbon Trust label and in the other condition they saw the same label, but with traffic light colors added to communicate the product's relative performance in terms of carbon footprint. All included attributes were found to have a significant impact on consumer choices...... to indicate relative carbon footprint significantly increases carbon label effectiveness. Hence, a carbon footprint label is more effective if it uses traffic light colors to communicate the product's relative performance....

  9. Increasing the Tensile Property of Unidirectional Carbon/Carbon Composites by Grafting Carbon Nanotubes onto Carbon Fibers by Electrophoretic Deposition

    Institute of Scientific and Technical Information of China (English)

    Qiang Song; Kezhi Li; Hejun Li; Qiangang Fu

    2013-01-01

    Although in-situ growing carbon nanotubes (CNTs) on carbon fibers could greatly increase the matrix-dominated mechanical properties of carbon/carbon composites (C/Cs),it always decreased the tensile strength of carbon fibers.In this work,CNTs were introduced into unidirectional carbon fiber (CF) preforms by electrophoretic deposition (EPD) and they were used to reinforce C/Cs.Effects of the content of CNTs introduced by EPD on tensile property of unidirectional C/Cs were investigated.Results demonstrated that EPD could be used as a simple and efficient method to fabricate carbon nanotube reinforced C/Cs (CNT-C/Cs) with excellent tensile strength,which pays a meaningful way to maximize the global performance of CNT-C/Cs.

  10. Carbon taxes and India

    Energy Technology Data Exchange (ETDEWEB)

    Fisher-Vanden, K.A.; Pitcher, H.M.; Edmonds, J.A.; Kim, S.H. [Pacific Northwest Lab., Richland, WA (United States); Shukla, P.R. [Indian Institute of Management, Ahmedabad (India)

    1994-07-01

    Using the Indian module of the Second Generation Model 9SGM, we explore a reference case and three scenarios in which greenhouse gas emissions were controlled. Two alternative policy instruments (carbon taxes and tradable permits) were analyzed to determine comparative costs of stabilizing emissions at (1) 1990 levels (the 1 X case), (2) two times the 1990 levels (the 2X case), and (3) three times the 1990 levels (the 3X case). The analysis takes into account India`s rapidly growing population and the abundance of coal and biomass relative to other fuels. We also explore the impacts of a global tradable permits market to stabilize global carbon emissions on the Indian economy under the following two emissions allowance allocation methods: (1) {open_quotes}Grandfathered emissions{close_quotes}: emissions allowances are allocated based on 1990 emissions. (2) {open_quotes}Equal per capita emissions{close_quotes}: emissions allowances are allocated based on share of global population. Tradable permits represent a lower cost method to stabilize Indian emissions than carbon taxes, i.e., global action would benefit India more than independent actions.

  11. Studies of Carbon Nanotubes

    Science.gov (United States)

    Caneba, Gerard T.

    2005-01-01

    The fellowship experience for this summer for 2004 pertains to carbon nanotube coatings for various space-related applications. They involve the following projects: (a) EMI protection films from HiPco-polymers, and (b) Thermal protection nanosilica materials. EMI protection films are targeted to be eventually applied onto casings of laptop computers. These coatings are composites of electrically-conductive SWNTs and compatible polymers. The substrate polymer will be polycarbonate, since computer housings are typically made of carbon composites of this type of polymer. A new experimental copolymer was used last year to generate electrically-conductive and thermal films with HiPco at 50/50 wt/wt composition. This will be one of the possible formulations. Reference films will be base polycarbonate and neat HiPco onto polycarbonate films. Other coating materials that will be tried will be based on HiPco composites with commercial enamels (polyurethane, acrylic, polyester), which could be compatible with the polycarbonate substrate. Nanosilica fibers are planned for possible use as thermal protection tiles on the shuttle orbiter. Right now, microscale silica is used. Going to the nanoscale will increase the surface-volume-per-unit-area of radiative heat dissipation. Nanoscale carbon fibers/nanotubes can be used as templates for the generation of nanosilica. A sol-gel operation is employed for this purpose.

  12. Hydropower's Biogenic Carbon Footprint.

    Science.gov (United States)

    Scherer, Laura; Pfister, Stephan

    2016-01-01

    Global warming is accelerating and the world urgently needs a shift to clean and renewable energy. Hydropower is currently the largest renewable source of electricity, but its contribution to climate change mitigation is not yet fully understood. Hydroelectric reservoirs are a source of biogenic greenhouse gases and in individual cases can reach the same emission rates as thermal power plants. Little is known about the severity of their emissions at the global scale. Here we show that the carbon footprint of hydropower is far higher than previously assumed, with a global average of 173 kg CO2 and 2.95 kg CH4 emitted per MWh of electricity produced. This results in a combined average carbon footprint of 273 kg CO2e/MWh when using the global warming potential over a time horizon of 100 years (GWP100). Nonetheless, this is still below that of fossil energy sources without the use of carbon capture and sequestration technologies. We identified the dams most promising for capturing methane for use as alternative energy source. The spread among the ~1500 hydropower plants analysed in this study is large and highlights the importance of case-by-case examinations. PMID:27626943

  13. Carbon Structure Hazard Control

    Science.gov (United States)

    Yoder, Tommy; Greene, Ben; Porter, Alan

    2015-01-01

    Carbon composite structures are widely used in virtually all advanced technology industries for a multitude of applications. The high strength-to-weight ratio and resistance to aggressive service environments make them highly desirable. Automotive, aerospace, and petroleum industries extensively use, and will continue to use, this enabling technology. As a result of this broad range of use, field and test personnel are increasingly exposed to hazards associated with these structures. No single published document exists to address the hazards and make recommendations for the hazard controls required for the different exposure possibilities from damaged structures including airborne fibers, fly, and dust. The potential for personnel exposure varies depending on the application or manipulation of the structure. The effect of exposure to carbon hazards is not limited to personnel, protection of electronics and mechanical equipment must be considered as well. The various exposure opportunities defined in this document include pre-manufacturing fly and dust, the cured structure, manufacturing/machining, post-event cleanup, and post-event test and/or evaluation. Hazard control is defined as it is applicable or applied for the specific exposure opportunity. The carbon exposure hazard includes fly, dust, fiber (cured/uncured), and matrix vapor/thermal decomposition products. By using the recommendations in this document, a high level of confidence can be assured for the protection of personnel and equipment.

  14. Carbon taxes and India

    International Nuclear Information System (INIS)

    Using the Indian module of the Second Generation Model 9SGM, we explore a reference case and three scenarios in which greenhouse gas emissions were controlled. Two alternative policy instruments (carbon taxes and tradable permits) were analyzed to determine comparative costs of stabilizing emissions at (1) 1990 levels (the 1 X case), (2) two times the 1990 levels (the 2X case), and (3) three times the 1990 levels (the 3X case). The analysis takes into account India's rapidly growing population and the abundance of coal and biomass relative to other fuels. We also explore the impacts of a global tradable permits market to stabilize global carbon emissions on the Indian economy under the following two emissions allowance allocation methods: (1) open-quotes Grandfathered emissionsclose quotes: emissions allowances are allocated based on 1990 emissions. (2) open-quotes Equal per capita emissionsclose quotes: emissions allowances are allocated based on share of global population. Tradable permits represent a lower cost method to stabilize Indian emissions than carbon taxes, i.e., global action would benefit India more than independent actions

  15. China's Transition to a Low-Carbon Economy: 2006-2010

    Institute of Scientific and Technical Information of China (English)

    o,~; Li Huimin

    2012-01-01

    China achieved major progress in low-carbon develop- ment during the period of the 11th Five Year Plan (2006-2010). The increasing trend of energy intensity and carbon intensity of the economy as seen prior to 2005 was reversed to a sharp decreas- ing trend, leading to a 19% decrease in energy intensity and 21% decrease in carbon intensity in five years. The enhanced energy efficiency, mostly due to efficiency improvement in power and manufacturing sector, is the major driver of the decrease in carbon intensity of the economy. The development of renewable energy, despite its impressive growth rate, played a minor role because of its small share in the energy mix of the country. Energy con- sumption and energy-related carbon emissions per unit of area in building continued to grow at a lesser rate, which, combined with the fast growth of total building volume, led to fast growth in total energy consumption and carbon emissions in the sector. Similar trend is observed in the transportation sector whose total energy use and carbon emissions continued to grow fast despite slight improvement in energy efficiency. Agricultural energy use expe- rienced a slight change and forestry made a major contribution to carbon sinks. Policy and institutional innovations helped build a solid system of rules for low-carbon development. Improving cost effectiveness of the system remains a major challenge for the next five year plan period.

  16. The impacts of '05.6' extreme flood event on riverine carbon fluxes in Xijiang River

    Institute of Scientific and Technical Information of China (English)

    SUN HuiGuo; HAN JingTai; ZHANG ShuRong; LU XiXi

    2007-01-01

    An extreme flood event with a frequency of nearly 200 year occurred in June of 2005 in the Xijiang River,the main trunk stream of the Zhujiang River. Samples were systematically collected during the flood event, and water quality parameters, including total suspended sediment (TSS), dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), and particulate organic carbon (POC) were analyzed,and riverine carbon concentrations associated with its changing pattern through the flood process were discussed. These parameters reflect the changes in basin surface flow and subsurface flow during the flood. This flood event influenced annual flux estimations of POC, DOC, and DIC to great extents.Based on carbon flux estimations for the year 2005 and the flood event (June 21-28) in the Xijiang River, it was found that DIC, DOC, and POC fluxes during '05.6' flood event are 1.52x106 g.km-2.a-1,0.24x106 g.km-2.a-1, and 0.54x106 g.km-2.a-1, and account for 14.87%, 24.75% and 44.89% of the annual fluxes in 2005, respectively. The results suggested that carbon exports during extreme flood events had great contributions to the total carbon fluxes and composition of various carbon components, being important for accurate estimates of annual carbon fluxes in rivers with frequent floods.

  17. Carbon and Nitrogen Contents in Typical Plants and Soil Profiles in Yanqi Basin of Northwest China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Juan; WANG Xiu-jun; WANG Jia-ping; WANG Wei-xia

    2014-01-01

    Carbon and nitrogen are the most important elements in the terrestrial ecosystem. Studying carbon and nitrogen distributions in plant and soil is important for our understanding of the ecosystem dynamics and carbon cycle on arid lands. A study was conducted in a typical arid area, the Yanqi Basin, Northwest China. Carbon and nitrogen distributions in plant tissues and soil proifles were determined at 21 sites with typical native plants and crops. Our results indicated that carbon content was similar between crops and native plants, and the average carbon contents in aboveground (42.4%) and belowground (42.8%) tissues were almost the same. Average nitrogen contents in crops were nearly the same (~0.7%) in aboveground and belowground tissues whereas mean nitrogen content was approximately 100% higher in aboveground (2.2%) than in belowground (1.2%) tissues for native species. Soil organic carbon (SOC) and total nitrogen (TN) in cropland (9.4 and 0.9 g kg-1) were signiifcantly higher than those in native land (6.2 and 0.7 g kg-1). Multiple regression analyses indicated that carbon content in belowground tissue and nitrogen content in aboveground tissue were key factors connecting plant and soil in native land. However, there was no signiifcant relationship for carbon or nitrogen between soil and crop, which might relfect human disturbance, such as plowing and applications of various organic materials.

  18. Nuclear power and carbon dioxide free automobiles

    International Nuclear Information System (INIS)

    Nuclear energy has been developed as a major source of electric power in Canada. Electricity from nuclear energy already avoids the emission of about 100 million tonnes of carbon dioxide to the atmosphere in Canada. This is a significant fraction of the 619 million tonnes of Canadian greenhouse gas emissions in 1995. However, the current scope of application of electricity to end use energy needs in Canada limits the contribution nuclear energy can make to carbon dioxide emission reduction. Nuclear energy can also contribute to carbon dioxide emissions reduction through expansion of the use of electricity to less traditional applications. Transportation, in particular contributed 165 million tonnes of carbon dioxide to the Canadian atmosphere in 1995. Canada's fleet of personal vehicles consisted of 16.9 million cars and light trucks. These vehicles were driven on average 21,000 km/year and generated 91 million tonnes of greenhouse gases expressed as a C02 equivalent. Technology to improve the efficiency of cars is under development which is expected to increase the energy efficiency from the 1995 level of about 10 litres/100 km of gasoline to under 3 litres/100km expressed as an equivalent referenced to the energy content of gasoline. The development of this technology, which may ultimately lead to the practical implementation of hydrogen as a portable source of energy for transportation is reviewed. Fuel supply life cycle greenhouse gas releases for several personal vehicle energy supply systems are then estimated. Very substantial reductions of greenhouse gas emissions are possible due to efficiency improvements and changing to less carbon intensive fuels such as natural gas. C02 emissions from on board natural gas fueled versions of hybrid electric cars would be decreased to approximately 25 million t/year from the current 91 million tonnes/year. The ultimate reduction identified is through the use of hydrogen fuel produced via electricity from CANDU power

  19. Hybrid Composites Based on Carbon Fiber/Carbon Nanofilament Reinforcement

    Directory of Open Access Journals (Sweden)

    Mehran Tehrani

    2014-05-01

    Full Text Available Carbon nanofilament and nanotubes (CNTs have shown promise for enhancing the mechanical properties of fiber-reinforced composites (FRPs and imparting multi-functionalities to them. While direct mixing of carbon nanofilaments with the polymer matrix in FRPs has several drawbacks, a high volume of uniform nanofilaments can be directly grown on fiber surfaces prior to composite fabrication. This study demonstrates the ability to create carbon nanofilaments on the surface of carbon fibers employing a synthesis method, graphitic structures by design (GSD, in which carbon structures are grown from fuel mixtures using nickel particles as the catalyst. The synthesis technique is proven feasible to grow nanofilament structures—from ethylene mixtures at 550 °C—on commercial polyacrylonitrile (PAN-based carbon fibers. Raman spectroscopy and electron microscopy were employed to characterize the surface-grown carbon species. For comparison purposes, a catalytic chemical vapor deposition (CCVD technique was also utilized to grow multiwall CNTs (MWCNTs on carbon fiber yarns. The mechanical characterization showed that composites using the GSD-grown carbon nanofilaments outperform those using the CCVD-grown CNTs in terms of stiffness and tensile strength. The results suggest that further optimization of the GSD growth time, patterning and thermal shield coating of the carbon fibers is required to fully materialize the potential benefits of the GSD technique.

  20. A carbon sink pathway increases carbon productivity in cyanobacteria.

    Science.gov (United States)

    Oliver, John W K; Atsumi, Shota

    2015-05-01

    The burning of fossil reserves, and subsequent release of carbon into the atmosphere is depleting the supply of carbon-based molecules used for synthetic materials including plastics, oils, medicines, and glues. To provide for future society, innovations are needed for the conversion of waste carbon (CO2) into organic carbon useful for materials. Chemical production directly from photosynthesis is a nascent technology, with great promise for capture of CO2 using sunlight. To improve low yields, it has been proposed that photosynthetic capacity can be increased by a relaxation of bottlenecks inherent to growth. The limits of carbon partitioning away from growth within the cell and the effect of partitioning on carbon fixation are not well known. Here we show that expressing genes in a pathway between carbon fixation and pyruvate increases partitioning to 2,3-butanediol (23BD) and leads to a 1.8-fold increase in total carbon yield in the cyanobacterium Synechococcus elongatus PCC 7942. Specific 2,3-butanediol production increases 2.4-fold. As partitioning increases beyond 30%, it leads to a steep decline in total carbon yield. The data suggests a local maximum for carbon partitioning from the Calvin Benson cycle that is scalable with light intensity.