WorldWideScience

Sample records for carbon 20

  1. A prism carbon molecule C$_20$

    OpenAIRE

    OHNO, Koichi; Satoh, Hiroko; Iwamoto, Takeaki

    2015-01-01

    A new carbon family with a prism structure has been found by quantum chemical calculations. The prism-$C_20$ has a $D_10h$ structure with double-layered decagonal rings connected each other by ten vertical CC bonds. The CC bond lengths are 0.144 nm on the decagonal rings and 0.148 nm on the side faces. The diameter of the ring is 0.465 nm. The $prism-C_20$ is expected to be stable, since the lowest energy barrier from it was estimated to be 158.0 kJ mol$^−1$.

  2. 46 CFR 95.15-20 - Carbon dioxide storage.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a... of not more than 300 pounds of carbon dioxide, may have the cylinders located within the...

  3. 46 CFR 76.15-20 - Carbon dioxide storage.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as... than 300 pounds of carbon dioxide, may have the cylinders located within the space protected. If...

  4. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Carbon-steel or alloy-steel castings. 59.20-1 Section 59... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  5. 20 years of Black Carbon measurements in Germany

    Science.gov (United States)

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

    2016-04-01

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

  6. Can Earth System Models Explain the observed 20th Century Global Carbon Sink?

    Science.gov (United States)

    Stouffer, R. J.; Shevliakova, E.; Malyshev, S.; Krasting, J. P.; Pacala, S.; Dunne, J. P.; John, J. G.

    2012-12-01

    Various authors have estimated the net global land carbon flux as a residual from the global budget of atmospheric, oceanic and fossil fuel carbon fluxes. Recently, Tans (2009) used this method to estimate the globally averaged net land carbon inventory changes method from 1850 to near present day. Using ocean model estimates of the oceanic carbon fluxes, he showed the land being a net source of carbon until around 1940, but after that becoming a net sink, with an uncertainty dominated by the net oceanic carbon flux trajectory (~15%; Sabine et al 2004). Recently Ballantyne et al (2012) produced updated estimates of the net carbon fluxes changes from 1960 until present day. They show that the net carbon flux uptake, land plus ocean, increases from around 2 PgC/yr in 1960 to about 5 PgC/yr in 2010. We compare these observationally based estimates with results from the GFDL Earth System Models (ESMs). We show that both GFDL ESMs store too much carbon in the atmosphere, about a 10 to 20 ppm error by 2005. The models have slightly higher mean values than the Tans (2009) oceanic carbon storage changes but fall within the Sabine et al. (2004) uncertainty estimate. While the general shape of the net land carbon changes in Tans (2009) is well simulated by the ESMs, the ESM sign change in land flux occurs about 15-25years later. By 2010, the models simulate the oceanic carbon uptake as ~2.7 PgC/yr, and the land uptake as ~1 PgC/yr for a total of ~4PgC/yr. The land uptake value varies with ensemble member giving evidence for the role of variability in understanding the past carbon changes. This analysis gives us confidence in the models estimates of the climate-carbon feedbacks. The model results will then be analyzed to determine the various causes of those changes.

  7. Dynamic Recrystallization and Grain Growth Behavior of 20SiMn Low Carbon Alloy Steel

    Institute of Scientific and Technical Information of China (English)

    DONG Lanfeng; ZHONG Yuexian; MA Qingxian; YUAN Chaolong; MA Lishen

    2008-01-01

    A senes of thermodynamics experiments were used to optimize the hot forging process of 20SiMn low-carbon alloy steel.A dynamic recrystallization and grain growth model was developed for the 20SiMn steel for common production conditions of heavy forgings by doing a nonlinear curve fit of the expenment data.Optimized forging parameters were developed based on the control of the dynamic recrystallization and the MnS secondary phase.The data shows that the initial grain size and the MnS secondary phase all affect the behavior of the 20SiMn dynamic recrystallization and grain growth.

  8. Assessing Impacts of 20 yr Old Miscanthus on Soil Organic Carbon Quality

    Science.gov (United States)

    Hu, Yaxian; Schäfer, Gerhard; Kuhn, Nikolaus

    2015-04-01

    The use of biomass as a renewable energy source has become increasingly popular in Upper Rhine Region to meet the demand for renewable energy. Miscanthus is one of the most favorite biofuel crops, due to its long life and large yields, as well as low energy and fertilizer inputs. However, current research on Miscanthus is mostly focused on the techniques and economics to produce biofuel or the impacts of side products such as ash and sulfur emissions to human health. Research on the potential impacts of Miscanthus onto soil quality, especially carbon quality after long-term adoption, is very limited. Some positive benefits, such as sequestrating organic carbon, have been repeatedly reported in previous research. Yet the quality of newly sequestrated organic carbon and its potential impacts onto global carbon cycling remain unclear. To fully account for the risks and benefits of Miscanthus, it is required to investigate the quality as well as the potential CO2 emissions of soil organic carbon on Miscanthus fields. As a part of the Interreg Project to assess the environmental impacts of biomass production in the Upper Rhine Region, this study aims to evaluate the carbon quality and the potential CO2 emissions after long-term Miscanthus adoption. Soils were sampled at 0-10, 10-40, 40-70, and 70-100 cm depths on three Miscanthus fields with up to 20 years of cultivation in Ammerzwiller France, Münchenstein Switzerland, and Farnsburg Switzerland. Soil texture, pH, organic carbon and nitrogen content were measured for each sampled layer. Topsoils of 0-10 cm and subsoils of 10-40 cm were also incubated for 40 days to determine the mineralization potential of the soil organic matter. Our results show that: 1) only in top soils of 0-10 cm, the 20 year old Miscanthus field has significantly higher soil organic carbon concentrations, than the control site. No significant differences were observed in deeper soil layers. Similar tendencies were also observed for organic

  9. Carbon dioxide emissions and governance: A nonparametric analysis for the G-20

    OpenAIRE

    Halkos, George; Tzeremes, Nickolaos

    2012-01-01

    This paper applies nonparametric estimators to examine countries’ carbon dioxide (CO2) emissions and governance relationship. By using data for the time period 1996-2010 of the twenty largest economies (Group of twenty, G-20) the dynamics of the considered relationship are analyzed. Six governance measures are included in our analysis (Voice and Accountability, Political Stability and Absence of Violence, Government Effectiveness, Regulatory Quality, Rule of Law and Control of Corruption) as ...

  10. Characterization and Design of the FutureGen 2.0 Carbon Storage Site

    Energy Technology Data Exchange (ETDEWEB)

    Gilmore, Tyler J.; Bonneville, Alain H.; Sullivan, Elsie C.; Kelley, Mark E.; Appriou, Delphine; Vermeul, Vincent R.; White, Signe K.; Zhang, Zhuanfang; Bjornstad, Bruce N.; Cornet, Francois; Gerst, Jacqueline L.; Gupta, Neeraj; Hund, Gretchen; Horner, Jacob A.; Last, George V.; Lanigan, David C.; Oostrom, Martinus; McNeil, Caitlin; Moody, Mark A.; Rockhold, Mark L.; Elliott, Michael L.; Spane, Frank A.; Strickland, Christopher E.; Swartz, Lucinda L.; Thorne, Paul D.; Brown, Christopher F.; Hoffmann, Jeffrey; Humphreys, Kenneth K.

    2016-07-29

    The objective of the FutureGen 2.0 Project was to demonstrate, at the commercial scale, the technical feasibility of implementing carbon capture and storage (CCS) in a deep saline formation in Illinois, USA. Over approximately 5 years, the FutureGen Alliance conducted a detailed site-selection process and identified a site for carbon sequestration storage in Morgan County, Illinois. The storage site was fully characterized, including the collection of seismic data and the drilling and characterization of a stratigraphic borehole. The characterization data provided critical input for developing a site-specific conceptual model and subsequent numerical modeling simulations. The modeling simulations, coupled with the upstream designs of the pipeline and power plant supported the development of a detailed 90 percent design that included the injection wells and associated control and monitoring infrastructure. Collectively, all these data were used by the FutureGen Alliance to develop the required documentation to support the applications for four underground injection control (UIC) permits (one for each proposed well). In August 2014, the U.S. Environmental Protection Agency issued four, first-of-their-kind, Class VI UIC permits for carbon sequestration in the United States to the FutureGen Alliance. The information and data generated under this project have been made publically available through reports and publications, including this journal and others.

  11. Study of 16O(12C,α20Ne)α for the investigation of carbon-carbon fusion reaction via the Trojan Horse Method

    Science.gov (United States)

    Rapisarda, G. G.; Spitaleri, C.; Bordeanu, C.; Hons, Z.; Kiss, G. G.; La Cognata, M.; Mrazek, J.; Nita, C.; Pantelica, D.; Petrascu, H.; Pizzone, R. G.; Romano, S.; Szücs, T.; Trache, L.; Tumino, A.; Velisa, G.

    2016-04-01

    Carbon-carbon fusion reaction represents a nuclear process of great interest in astrophysics, since the carbon burning is connected with the third phase of massive stars (M > 8 M⊙) evolution. In spite of several experimental works, carbon-carbon cross section has been measured at energy still above the Gamow window moreover data at low energy present big uncertainty. In this paper we report the results about the study of the 16O(12C,α 20Ne)α reaction as a possible three-body process to investigate 12C(12C,α)20Ne at astrophysical energy via Trojan Horse Method (THM). This study represents the first step of a program of experiments aimed to measure the 12C+12C cross section at astrophysical energy using the THM.

  12. Uniaxial ratchetting of 20 carbon steel: Macroscopic and microscopic experimental observations

    International Nuclear Information System (INIS)

    Highlights: → Sub-grains are formed during the ratchetting deformation. → Sub-grains are formed by the re-arrangement of dislocation. → Re-arrangement of dislocation results in a constant ratchetting rate. → New dislocation slip will occur inside the formed sub-grains. - Abstract: The uniaxial ratchetting of polycrystalline 20 ordinary carbon steel (denoted as 20CS), a body-centred cubic (BCC) crystal structure metal, was investigated by macroscopic and microscopic observations at room temperature. The microscopic observations were performed by transmission electron microscopy (TEM) to the samples of 20CS obtained at different stages of monotonic tension, strain-controlled cyclic tension-compression and uniaxial ratchetting deformation. Main attention was paid on the dislocation patterns and their evolution during the ratchetting deformation. The results show that the dislocation patterns evolve from some low density modes such as dislocation lines and networks to those with high density, i.e., dislocation tangles, walls and cells. And then, sub-grain structures are formed by the re-arrangement of dislocation after certain number of cycles during the ratchetting deformation. The uniaxial ratchetting of 20CS is qualitatively explained by considering the observed dislocation patterns and their evolution with the increasing number of cycles and comparing with the patterns observed during the monotonic tension and strain-controlled cyclic tension-compression tests.

  13. Carbon Ion Radiotherapy in Advanced Hypofractionated Regimens for Prostate Cancer: From 20 to 16 Fractions

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Tohru [National Institute of Radiological Sciences, Chiba (Japan); Tsuji, Hiroshi, E-mail: h_tsuji@nirs.go.jp [National Institute of Radiological Sciences, Chiba (Japan); Kamada, Tadashi [National Institute of Radiological Sciences, Chiba (Japan); Akakura, Koichiro; Suzuki, Hiroyoshi; Shimazaki, Jun [Department of Urology, Graduate School of Medicine, Chiba University, Chiba (Japan); Tsujii, Hirohiko [National Institute of Radiological Sciences, Chiba (Japan)

    2012-11-15

    Purpose: To assess the effects of differences in dose fractionation on late radiation toxicity and biochemical control in patients with prostate cancer treated with carbon ion radiotherapy (C-ion RT). Methods and Materials: A total of 740 prostate cancer patients who received C-ion RT between April 2000 and February 2009 were analyzed. Of those, 664 patients followed for at least 1 year were analyzed with regard to late radiation toxicity. Biochemical relapse-free (BRF) and overall survival (OS) rates in patient subgroups with each dose-fractionation were analyzed. Results: Only 1 case of grade 3 genitourinary (GU) morbidity was observed in 20 fractions, and none of the patients developed higher grade morbidities. The incidence of late GU toxicity in patients treated with 16 fractions was lower than that of patients treated with 20 fractions. The OS rate and BRF rate of the entire group at 5 years were 95.2% and 89.7%, respectively. The 5-year BRF rate of the patients treated with 16 fractions of C-ion RT (88.5%) was comparable to that of the patients treated with 20 fractions (90.2%). Conclusion: C-ion RT of 57.6 GyE (the physical C-ion dose [Gy] Multiplication-Sign RBE) in 16 fractions could offer an even lower incidence of genitourinary toxicity and comparable BRF rate than that in 20 fractions. Advancement in hypofractionation could be safely achieved with C-ion RT for prostate cancer.

  14. Carbonated Eclogite Solidus Between 14 and 20 GPa: Results from the Model CMAS-CO2 System and Contrasting Solidus Behavior to Carbonated Peridotite

    Science.gov (United States)

    Keshav, S.; Gudfinnsson, G. H.

    2007-12-01

    The carbonate ledge at ~2.0 GPa is a pronounced feature of the carbonated peridotite solidus. At the ledge, where the CO2-bearing phase changes from vapour to carbonate, the melt composition becomes carbonatitic. After this drop, the solidus of carbonated peridotite gradually rises in P-T space, up to at least 12 GPa. Between 14 and 16 GPa, Keshav et al. (2007) reported another drop in the solidus of carbonated peridotite in the model CMS-CO2 system. Similar to the lower-pressure topology, the solidus at higher pressure resumes a positive slope between 16-20 GPa, and seems to flatten between 22 and 26 GPa. Concomitant with this second drop, the melts become extremely calcic (Ca/Ca+Mg, Ca no.-0.62) at 16 and 20 GPa, but attain more magnesio-carbonatitic (Ca no.-0.40) character both at shallower or greater depths than the transition zone. Clearly, the second drop in the carbonated peridotite solidus has tremendous consequences for geological processes in the deep mantle. The other major rock-type presumed to be present in the mantle is eclogite of broadly basaltic composition. Clarifying the solidus topology of carbonated eclogite in model systems over a similar pressure range is also an important task, because the solidus topology affects the fate of subducted carbonate in the deeper mantle. The position of the solidus of carbonated eclogite will address its impact on local or extensive melting (if it occurs), the possible relationship between the carbonated peridotite and carbonated eclogite solidi at these depths (400-600 km), their respective incipient melts, and ultimately the possibility of carbonate survival at these and greater depths. With these issues in mind, we have determined the solidus of model carbonated eclogite in model CMAS- CO2 system between 14 and 20 GPa. At 14 and 16 GPa, the melts are in equilibrium with cpx, majoritic garnet, stishovite, and magnesite. At 20 GPa, the melts are in equilibrium with calcium-perovskite (capv), garnet, stishovite

  15. Biogas desulfurization with a new developed doped activated carbon. 20 month pilot test; Biogasfeinentschwefelung mittels neu entwickelter dotierter Aktivkohle. 20-monatiger Praxistest

    Energy Technology Data Exchange (ETDEWEB)

    Rossow, Silvana; Deerberg, Goerge; Goetze, Toralf; Kanswohl, Norbert; Nelles, Michael [Univ. Rostock (Germany). Lehrstuhl fuer Abfall- und Stoffstromwirtschaft

    2009-05-15

    Doped activated carbon is a special developed activated carbon for the desulfurization of technical gases. Based on its special adsorption properties, it is able to bond a large amount of hydrogen sulfide. By the special manufacturing method it was possible to optimize further the performance for the desulfurization of gases. In a biogas plant with an installed electric capacity of 2 MW the functionality of the doped activated carbon was proofed in a real biogas stream in a 20 month pilot test. The activated carbon was used in a special adsorption system that was tunes on the requirement of the activated carbon and on the site of installation. Because the biogas plant was in the starting period, all the time there were variable operation conditions. In spite of the variable conditions the doped activated carbon shows a permanent complete desulfurization, as in the executed laboratory experiments. By the use of the desulfurization system the concentration of hydrogen sulfide is decreased less than 1 ppm. The prejudices with are often caused by hydrogen sulphide could not identify until now. A positive evidence of the excellent desulfurization is the doubling of the oil lifetime of the block heating station. (orig.)

  16. Climate and carbon cycle variations in the 20th and 21st centuries in a model of intermediate complexity

    Science.gov (United States)

    Eliseev, A. V.; Mokhov, I. I.; Karpenko, A. A.

    2007-02-01

    The climate model of intermediate complexity developed at the Oboukhov Institute of Atmospheric Physics, Russian Academy of Sciences (IAP RAS CM), has been supplemented by a zero-dimensional carbon cycle model. With the carbon dioxide emissions prescribed for the second half of the 19th century and for the 20th century, the model satisfactorily reproduces characteristics of the carbon cycle over this period. However, with continued anthropogenic CO2 emissions (SRES scenarios A1B, A2, B1, and B2), the climate-carbon cycle feedback in the model leads to an additional atmospheric CO2 increase (in comparison with the case where the influence of climate changes on the carbon exchange between the atmosphere and the underlying surface is disregarded). This additional increase is varied in the range 67 90 ppmv depending on the scenario and is mainly due to the dynamics of soil carbon storage. The climate-carbon cycle feedback parameter varies nonmonotonically with time. Positions of its extremes separate characteristic periods of the change in the intensity of anthropogenic emissions and of climate variations. By the end of the 21st century, depending on the emission scenario, the carbon dioxide concentration is expected to increase to 615 875 ppmv and the global temperature will rise by 2.4 3.4 K relative to the preindustrial value. In the 20th 21st centuries, a general growth of the buildup of carbon dioxide in the atmosphere and ocean and its reduction in terrestrial ecosystems can be expected. In general, by the end of the 21st century, the more aggressive emission scenarios are characterized by a smaller climate-carbon cycle feedback parameter, a lower sensitivity of climate to a single increase in the atmospheric concentration of carbon dioxide, a larger fraction of anthropogenic emissions stored in the atmosphere and the ocean, and a smaller fraction of emissions in terrestrial ecosystems.

  17. Surface treatment of 0.20% C carbon steel by high-current pulsed electron beam

    Institute of Scientific and Technical Information of China (English)

    XU Guo-cheng; FU Shi-you; GUAN Qing-feng

    2006-01-01

    A high-current pulsed electron beam(HCPEB) generated on the system of Nadezhda-2 was applied to improve the microstructure and performance of 0.20% C low carbon steel. Surface layers of the samples bombarded by explosive electron beam at different pulses was observed by using electron microscopy. The physical model of the thermal-stress process and related modification mechanism as a result of HCPEB irradiation was also investigated. After HCPEB post treatments, obvious changes in microstructure and significant hardening occur in the depth of 200-250 μm from the surface after HCPEB irradiation. Rapid heating and subsequent rapid solidification induce heavy plastic deformation, which results in that the laminated structure of pearlite is substituted by dispersive rounded-like cementites in the near-surface. The effect of HCPEB treatment can reach more than 500 m depth from the surface. The original crystalline structure is changed to a different degree that grows with the numbers of bombardment, and in the surface layer amorphous states and nanocrystaline structures consisting of grains of γ-phase and cementite are found. The violent stress induced by HCPEB irradiation is the origin of the nanostructured and amorphous structure formation.

  18. An evaluation of the neutron-induced reaction cross sections on carbon from 10 to 20 MeV

    International Nuclear Information System (INIS)

    Available data on the neutron-induced reactions on carbon are reviewed for the energy range from 10 to 20 MeV. Evaluated cross sections obtained at Bruyeres-le-Chatel are discussed. Comparisons with coupled-channel calculations are presented for the total, elastic and inelastic (to the 2+ level) cross sections of 12C

  19. Carbon dioxide as a venous contrast agent: Applications in interventional radiology=20

    International Nuclear Information System (INIS)

    To evaluate the safety and usefulness of carbon dioxide(CO2) as a venous contrast agent for upper-arm placement of peripherally inserted central venous catheter (PICC), vena caval filter placement, and for visualization of the portal vein in transjugular intrahepatic portosystemic shunt(TIPS). About 20-30ml of CO2 was used as an alternative to iodinated contrast material for digital subtraction angiography (DSA) and fluoroscopy to guide upper-arm placement of PICC in 46 patients, for inferior venacavogram before filter placement in five, and for visualization of the portal vein during TIPS in two. Vital signs, peripheral arterial oxygen saturation, and renal function were checked during and after delivery of CO2. All CO2 DSA for PICC placement clearly delineated patency or stenosis of the central veins. In 41 of 46 patients (89 %), PICC placement with CO2 guidance was successful. The mean number of venipunctures for PICC placement was 1.9, and the mean volume of CO2 injected for venipuncture was 35ml. In five patients, Titanium Greenfield filters were successfully implanted into the inferior vena cava following CO2 vena cavography. In two patients in whom hepatopetal portal flow was seen on indirect portography, the portal vein was visualized by CO2-wedged hepatic venography. Injection of CO2 into the splenic vein following TIPS placement revealed shunt patency. Vital signs and oxygen saturation did not change, and there was no evidence of renal toxicity following CO2injection. CO2 is a safe and useful alternative contrast agent for upper-arm placement of PICC, pre-filter placement cavography, and wedged hepatic venography and portography for TIPS

  20. Effects of carbon, chromium and molybdenum contents on solidification and microstructure of 15 or 20% Cr white cast irons

    International Nuclear Information System (INIS)

    Solidification experiments were performed on 30 mm diameter test pieces of while irons containing 15 or 20% chromium and 2,3 3,0 and 3,6% carbon, with additions of zero, 1,5 or 2,5% molybdenum for each carbon content. Measurements were made of: austenite and eutectic temperature arrest; number of eutectic carbide particles relative to total volume and to eutectic volume; volume fraction of primary austenite. It was observed that increasing carbon contents caused lower austenite and eutectic formation temperature arrest, reduced number of carbide p;articles in eutectic volume and smaller volume fraction of primary austenite. The addition of molybdenum led to lower austenite and eutectic formation temperature arrests, less carbide particles in total and in eutectic volume, and larger volume fraction of primary austenite. As compared to 15% chromium alloys, the 20% chromium alloys showed higher eutectic temperature arrests, more carbide particles both in the total volume and in the eutectic volume, and smaller volume fraction of primary austenite. (author)

  1. The 20th century carbon budget simulated with the CCCma earth system model CanESM1

    Science.gov (United States)

    Arora, V. K.; Boer, G. J.; Curry, C. L.; Christian, J. R.; Zahariev, K.; Denman, K. L.; Flato, G. M.; Scinocca, J. F.; Merryfield, W. J.; Lee, W. G.

    2008-12-01

    The atmosphere-land-ocean CO2 exchange for the 1850-2000 period, as simulated with the Canadian Centre for Climate Modelling and Analysis Earth System Model (CanESM1), is assessed. Land use change (LUC) emissions are estimated interactively on the basis of changes in crop area. In its default configuration, the terrestrial CO2 uptake in the model is higher and atmospheric CO2 concentration lower than observed for the 1850-2000 period. This is likely due to lower simulated LUC emissions in the model because LUC due to changes in pasture area and forest harvesting are not taken into account, although LUC emissions are highly uncertain (± 50% uncertainty). Down-regulation of photosynthesis is observed in many experimental studies that grow plants at ambient and elevated CO2. However, the role of down- regulation of terrestrial photosynthesis in the carbon cycle has not yet been explored. We examine the effect of photosynthesis down-regulation by implementing an empirical down-regulation mechanism based on experimental studies of plant growth under conditions of increased CO2. The rate of increase of terrestrial net primary productivity with CO2 in the model, after down-regulation, is consistent with that inferred from an independent study. When down-regulation is implemented, the 20th century land and ocean carbon uptake and atmospheric CO2 concentration are in good agreement with observation-based estimates. Our results show that down-regulation of terrestrial photosynthesis may play a role in terrestrial carbon uptake similar in magnitude to the uncertainty in LUC emissions. The empirical approach used here also offers a reasonable method of implementing down-regulation for coupled carbon-climate simulations in the absence of a more explicit biogeochemical representation in models.

  2. Equilibrium and non-equilibrium charge-state distributions of 2.0 MeV/u carbon ions passing through carbon foils

    International Nuclear Information System (INIS)

    Both equilibrium and non-equilibrium charge-state distributions were studied experimentally for 2.0 MeV/u carbon ions after passing through carbon foils. Measured charge-state distribution established the equilibrium at a target thickness of 10 μg/cm2 and this remained unchanged until a maximum target thickness of 98 μg/cm2. The equilibrium charge-state distribution, the equilibrium mean charge-state, and the width and skewness of the equilibrium distribution were compared with predictions using existing semi-empirical formulae as well as simulation results, including the ETACHA code. It was found that charge-state distributions, mean charge states, and distribution widths for C2+, C3+, and C4+ incident ions merged into quasi-equilibrium values at a target thickness of 5.7 μg/cm2 in the pre-equilibrium region and evolved simultaneously to the ‘real equilibrium’ values for all of the initial charge states, including C5+ and C6+ ions, as previously demonstrated for sulfur projectile ions at the same velocity (Imai et al., 2009). Two kinds of simulation, ETACHA and solution of rate equations taking only single electron transfers into account, were used, and both of them reproduced the measured charge evolution qualitatively. The quasi-equilibrium behavior could be reproduced with the ETACHA code, but not with solution of elementary rate equations

  3. LAKE 2.0: a model for temperature, methane, carbon dioxide and oxygen dynamics in lakes

    Science.gov (United States)

    Stepanenko, Victor; Mammarella, Ivan; Ojala, Anne; Miettinen, Heli; Lykosov, Vasily; Vesala, Timo

    2016-05-01

    A one-dimensional (1-D) model for an enclosed basin (lake) is presented, which reproduces temperature, horizontal velocities, oxygen, carbon dioxide and methane in the basin. All prognostic variables are treated in a unified manner via a generic 1-D transport equation for horizontally averaged property. A water body interacts with underlying sediments. These sediments are represented by a set of vertical columns with heat, moisture and CH4 transport inside. The model is validated vs. a comprehensive observational data set gathered at Kuivajärvi Lake (southern Finland), demonstrating a fair agreement. The value of a key calibration constant, regulating the magnitude of methane production in sediments, corresponded well to that obtained from another two lakes. We demonstrated via surface seiche parameterization that the near-bottom turbulence induced by surface seiches is likely to significantly affect CH4 accumulation there. Furthermore, our results suggest that a gas transfer through thermocline under intense internal seiche motions is a bottleneck in quantifying greenhouse gas dynamics in dimictic lakes, which calls for further research.

  4. A significant carbon sink in temperate forests in Beijing: based on 20-year field measurements in three stands.

    Science.gov (United States)

    Zhu, JianXiao; Hu, XueYang; Yao, Hui; Liu, GuoHua; Ji, ChenJun; Fang, JingYun

    2015-11-01

    Numerous efforts have been made to characterize forest carbon (C) cycles and stocks in various ecosystems. However, long-term observation on each component of the forest C cycle is still lacking. We measured C stocks and fluxes in three permanent temperate forest plots (birch, oak and pine forest) during 2011–2014, and calculated the changes of the components of the C cycle related to the measurements during 1992–1994 at Mt. Dongling, Beijing, China. Forest net primary production in birch, oak, and pine plots was 5.32, 4.53, and 6.73 Mg C ha-1 a-1, respectively. Corresponding net ecosystem production was 0.12, 0.43, and 3.53 Mg C ha-1 a-1. The C stocks and fluxes in 2011–2014 were significantly larger than those in 1992–1994 in which the biomass C densities in birch, oak, and pine plots increased from 50.0, 37.7, and 54.0 Mg C ha-1 in 1994 to 101.5, 77.3, and 110.9 Mg C ha-1 in 2014; soil organic C densities increased from 207.0, 239.1, and 231.7 Mg C ha-1 to 214.8, 241.7, and 238.4 Mg C ha-1; and soil heterotrophic respiration increased from 2.78, 3.49, and 1.81 Mg C ha-1 a-1 to 5.20, 4.10, and 3.20 Mg C ha-1 a-1. These results suggest that the mountainous temperate forest ecosystems in Beijing have served as a carbon sink in the last two decades. These observations of C stocks and fluxes provided field-based data for a long-term study of C cycling in temperate forest ecosystems. PMID:26501378

  5. A significant carbon sink in temperate forests in Beijing: based on 20-year field measurements in three stands

    Science.gov (United States)

    Zhu, J.

    2015-12-01

    Numerous efforts have been made to characterize the forest carbon (C) cycles and stocks. However, long-term observation-based quantification on each component of the forest C cycle and its change is still lacking. We measured C stocks and fluxes in three permanent temperate forest plots (birch, oak and pine forest plots) during 2011-2014 and calculated the changes of the C cycle components related to the measurements during 1992-1994 in Mt. Dongling, Beijing, China. Our results showed that forest net primary production in birch, oak and pine plots were 5.32, 4.53 and 6.73 Mg C ha-1 yr-1, respectively. The corresponding net ecosystem production were 0.12, 0.43 and 3.53 Mg C ha-1 yr-1. The C stocks and fluxes in 2011-2014 were significantly larger than those in 1992-1994: the biomass C densities in birch, oak and pine plots increased from 50.0, 37.7 and 54.0 Mg C ha-1 in 1994 to 101.5, 77.3 and 110.9 Mg C ha-1 in 2014; soil organic C densities from 207.0, 239.1 and 231.7 Mg C ha-1 to 214.8, 241.7 and 238.4 Mg C ha-1; and soil heterotrophic respiration from 2.78, 3.49 and 1.81 Mg C ha-1 yr-1 to 5.20, 4.10 and 3.20 Mg C ha-1 yr-1. These results suggest that the mountainous temperate forest ecosystems are a carbon sink in the recent two decades. These observations of C densities and fluxes provided field-based data for long-term study of C cycling in temperate forest ecosystems.

  6. Test Measurements of a 20 ms-1 Carbon Wire Beam Scanner

    CERN Document Server

    De Freitas, J; Emery, J; Herranz Alvarez, J F; Koujili, M; Ramos, D; Sapinski, M; Ait-Amira, Y; Djerdir, A

    2011-01-01

    This paper pre­sents the de­sign of the ac­tu­a­tor for the fast and high ac­cu­ra­cy Wire Scan­ner sys­tem. The ac­tu­a­tor con­sists of a ro­tary brushless syn­chronous motor with the per­ma­nent mag­net rotor in­stalled in­side the vac­u­um cham­ber and the sta­tor in­stalled out­side. The fork, per­ma­nent mag­net rotor and two an­gu­lar po­si­tion sen­sors are mount­ed on the same axis and lo­cat­ed in­side the beam vac­u­um cham­ber. The system has to re­sist a bake-out tem­per­a­ture of 200 C and ion­iz­ing radi­a­tion up to tenths of kGy/year. Max­i­mum wire trav­el­ling speed of 20 m/s and a po­si­tion mea­sure­ment ac­cu­ra­cy of 4 um is re­quired. Therefore, the sys­tem must avoid gen­er­at­ing vi­bra­tion and electromagnet­ic in­ter­fer­ence. A dig­i­tal feed­back con­troller will allow max­i­mum flex­i­bil­i­ty for the loop pa­ram­e­ters and feeds the 3-phase lin­ear power driv­er. The per­for­mance of the pr...

  7. INFLUENCE OF SINTERING TEMPERATURE ON THE POLARIZATION RESISTANCE OF LaO20.6SrO20.4CoO20.2FeO20.8O3-δ - SDC CARBONATE COMPOSITE CATHODE

    Directory of Open Access Journals (Sweden)

    Nurul Akidah Baharuddin

    2016-05-01

    Full Text Available The effects of sintering temperature of an LSCF-samarium-doped ceria carbonate (SDCC cathode composite film on its polarization resistance (Rp were evaluated in this study. An LSCF-SDCC composite cathode was prepared for cathode film development by electrophoretic deposition (EPD. The LSCF-SDCC composite cathode was prepared at 50:50 weight percentage ratio. An EPD suspension which is based on an organic aqueous solution was used, and a mixture of ethanol and deionized water was used as medium with poly diallyl dimethyl ammonium chloride (PDADMAC as a dispersing agent. SDCC substrate was used, and EPD was performed on both sides. A symmetrical cell with cathode composite LSCF-SDCC films on both sides of the substrate was subjected to sintering at five different temperatures (from 550°C to 750°C. A symmetrical cell was painted using silver paste before undergoing electrochemical performance test (air condition, in which the impedance, Z data, was measured. The effects of sintering temperature change on element content and film porosity were first investigated by energy-dispersive X-ray spectroscopy, field emission scanning electron microscopy, and J-image analysis. Ceramic-based cathode LSCF-SDCC that was sintered at 600°C exhibited the lowest Rp at a value of 0.68 Ω when operated at 650°C. This study proved that EPD has potential in developing IT-LT solid oxide fuel cell cathode components with high electrochemical performance in terms of Rp values.

  8. Accurate (p, ρ, T) data for two new (carbon dioxide + nitrogen) mixtures from (250 to 400) K at pressures up to 20 MPa

    International Nuclear Information System (INIS)

    Highlights: ► New (p, ρ, T) data of two mixtures of nitrogen and carbon dioxide are reported. ► Experimental data show a disagreement with the equation of state at low temperatures and high pressures. ► Relative deviations in density increase with the carbon dioxide molar fraction of the mixture. ► Only relative deviations at pressures below 10 MPa are within a 0.1% band. - Abstract: Recently our group published a set of (p, ρ, T) data for two (carbon dioxide + nitrogen) mixtures with a low carbon dioxide content (xCO2=0.10,0.15). These data showed larger relative deviations from the GERG-2008 equation of state than expected, specially at low temperatures, high pressures, and for the mixture with higher carbon dioxide content (xCO2=0.15). In order to analyze whether the mentioned deviations from the equation of state increase with the carbon dioxide content, it was decided to measure the (p, ρ, T) behavior of two additional mixtures with higher carbon dioxide molar fractions (xCO2=0.20,0.50). The new experimental data show again an appreciable disagreement with the GERG-2008 equation of state at low temperatures and high pressures. Relative deviations, which depend on temperature, arise to 0.4% at 250 K and 20 MPa and to 0.24% at 275 K and 20 MPa for the xCO2=0.20 and xCO2=0.50 mixture, respectively. Second virial coefficients are calculated for the two new mixtures presented in this work and also for those presented in our previous paper.

  9. MEDUSA-2.0: an intermediate complexity biogeochemical model of the marine carbon cycle for climate change and ocean acidification studies

    Directory of Open Access Journals (Sweden)

    A. Yool

    2013-02-01

    Full Text Available MEDUSA-1.0 (Model of Ecosystem Dynamics, nutrient Utilisation, Sequestration and Acidification was developed as an "intermediate complexity" plankton ecosystem model to study the biogeochemical response, and especially that of the so-called "biological pump", to anthropogenically-driven change in the World Ocean (Yool et al., 2011. The base currency in this model was nitrogen from which fluxes of organic carbon, including export to the deep ocean, were calculated by invoking fixed C:N ratios in phytoplankton, zooplankton and detritus. Since the beginning of the industrial era, the atmospheric concentration of carbon dioxide (CO2 has significantly increased above its natural, inter-glacial background concentration. Simulating and predicting the carbon cycle in the ocean in its entirety, including ventilation of CO2 with the atmosphere and the resulting impact of ocean acidification on marine ecosystems, therefore requires that both organic and inorganic carbon be afforded a full representation in the model specification. Here, we introduce MEDUSA-2.0, an expanded successor model which includes additional state variables for dissolved inorganic carbon, alkalinity, dissolved oxygen and detritus carbon (permitting variable C:N in exported organic matter, as well as a simple benthic formulation and extended parameterisations of phytoplankton growth, calcification and detritus remineralisation. A full description of MEDUSA-2.0, including its additional functionality, is provided and a multi-decadal hindcast simulation described (1860–2005, to evaluate the biogeochemical performance of the model.

  10. Isotopic signatures of continental and marine carbonates from the Magondi belt, Zimbabwe: implications for the global carbon cycle at 2,0 Ga

    International Nuclear Information System (INIS)

    Carbon, oxygen and strontium isotope studies have been carried out on continental and marine carbonates of the early Proterozoic Magondi Belt in Zimbabwe. A new model is presented to explain the global carbon isotope anomaly in 2 Ga old rocks, in the light of recent research on the effects of volcanism and global catastrophes on the biosphere, and on isotopes in the geological record. 16 refs

  11. MEDUSA-2.0: an intermediate complexity biogeochemical model of the marine carbon cycle for climate change and ocean acidification studies

    Directory of Open Access Journals (Sweden)

    A. Yool

    2013-10-01

    Full Text Available MEDUSA-1.0 (Model of Ecosystem Dynamics, nutrient Utilisation, Sequestration and Acidification was developed as an "intermediate complexity" plankton ecosystem model to study the biogeochemical response, and especially that of the so-called "biological pump", to anthropogenically driven change in the World Ocean (Yool et al., 2011. The base currency in this model was nitrogen from which fluxes of organic carbon, including export to the deep ocean, were calculated by invoking fixed C:N ratios in phytoplankton, zooplankton and detritus. However, due to anthropogenic activity, the atmospheric concentration of carbon dioxide (CO2 has significantly increased above its natural, inter-glacial background. As such, simulating and predicting the carbon cycle in the ocean in its entirety, including ventilation of CO2 with the atmosphere and the resulting impact of ocean acidification on marine ecosystems, requires that both organic and inorganic carbon be afforded a more complete representation in the model specification. Here, we introduce MEDUSA-2.0, an expanded successor model which includes additional state variables for dissolved inorganic carbon, alkalinity, dissolved oxygen and detritus carbon (permitting variable C:N in exported organic matter, as well as a simple benthic formulation and extended parameterizations of phytoplankton growth, calcification and detritus remineralisation. A full description of MEDUSA-2.0, including its additional functionality, is provided and a multi-decadal spin-up simulation (1860–2005 is performed. The biogeochemical performance of the model is evaluated using a diverse range of observational data, and MEDUSA-2.0 is assessed relative to comparable models using output from the Coupled Model Intercomparison Project (CMIP5.

  12. MEDUSA-2.0: an intermediate complexity biogeochemical model of the marine carbon cycle for climate change and ocean acidification studies

    Science.gov (United States)

    Yool, A.; Popova, E. E.; Anderson, T. R.

    2013-10-01

    MEDUSA-1.0 (Model of Ecosystem Dynamics, nutrient Utilisation, Sequestration and Acidification) was developed as an "intermediate complexity" plankton ecosystem model to study the biogeochemical response, and especially that of the so-called "biological pump", to anthropogenically driven change in the World Ocean (Yool et al., 2011). The base currency in this model was nitrogen from which fluxes of organic carbon, including export to the deep ocean, were calculated by invoking fixed C:N ratios in phytoplankton, zooplankton and detritus. However, due to anthropogenic activity, the atmospheric concentration of carbon dioxide (CO2) has significantly increased above its natural, inter-glacial background. As such, simulating and predicting the carbon cycle in the ocean in its entirety, including ventilation of CO2 with the atmosphere and the resulting impact of ocean acidification on marine ecosystems, requires that both organic and inorganic carbon be afforded a more complete representation in the model specification. Here, we introduce MEDUSA-2.0, an expanded successor model which includes additional state variables for dissolved inorganic carbon, alkalinity, dissolved oxygen and detritus carbon (permitting variable C:N in exported organic matter), as well as a simple benthic formulation and extended parameterizations of phytoplankton growth, calcification and detritus remineralisation. A full description of MEDUSA-2.0, including its additional functionality, is provided and a multi-decadal spin-up simulation (1860-2005) is performed. The biogeochemical performance of the model is evaluated using a diverse range of observational data, and MEDUSA-2.0 is assessed relative to comparable models using output from the Coupled Model Intercomparison Project (CMIP5).

  13. Molecular Basis of Microbial One-Carbon Metabolism 2008 Gordon Research Conference (July 20-25, 2008)

    Energy Technology Data Exchange (ETDEWEB)

    Stephen W. Ragsdale

    2009-08-12

    One-carbon (C-1) compounds play a central role in microbial metabolism. C-1 compounds include methane, carbon monoxide, CO2, and methanol as well as coenzyme-bound one-carbon compounds (methyl-B12, CH3-H4folate, etc). Such compounds are of broad global importance because several C-1 compounds (e.g., CH4) are important energy sources, some (e.g., CO2 and CH4) are potent greenhouse gases, and others (e.g., CH2Cl2) are xenobiotics. They are central in pathways of energy metabolism and carbon fixation by microbes and many are of industrial interest. Research on the pathways of one-carbon metabolism has added greatly to our understanding of evolution, structural biology, enzyme mechanisms, gene regulation, ecology, and applied biology. The 2008 meeting will include recent important findings in the following areas: (a) genomics, metagenomics, and proteomic studies that have expanded our understanding of autotrophy and C-1 metabolism and the evolution of these pathways; (b) redox regulation of carbon cycles and the interrelationship between the carbon cycle and other biogeochemical cycles (sulfur, nitrogen, oxygen); (c) novel pathways for carbon assimilation; (d) biotechnology related to C-1 metabolism; (e) novel enzyme mechanisms including channeling of C-1 intermediates during metabolism; and (f) the relationship between metal homeostasis and the global carbon cycle. The conference has a diverse and gender-balanced slate of speakers and session leaders. The wide variety of disciplines brought to the study of C-1 metabolism make the field an excellent one in which to train young researchers.

  14. Tight-binding molecular dynamic simulations of (18,0), (19,0) and (20,0) single walled carbon nanotubes under uniaxial strain

    International Nuclear Information System (INIS)

    Single Walled Carbon Nanotubes (SWCNTs) have attracted wide attention for application in nano-devices due to their electronic and mechanic properties. The electronic structure of SWCNT's is mostly determined by the chirality of the tubes. Depending on their chirality, they could be metal or semiconductor. Electrical conductivity of SWCNTs may also change due to deformations such as uniaxial strain. We have studied the behavior of electronic properties of (18,0), (19,0) and (20,0) SWCNTs under uniaxial strain. Mechanical properties of the zig-zag SWCNTs are also obtained. During our simulations we used the parallel, Order N Tight-Binding Molecular Dynamics technique which is improved and successfully applied to SWCNT simulations by G. Dereli et. al. The research reported here was supported through the Yildiz Technical University Research Found Project No: 24-01-01-04. Simulations are performed in parallel environment at Carbon Nanotube Simulation Laboratory of Yildiz Technical University.

  15. Carbon cycling in extratropical terrestrial ecosystems of the Northern Hemisphere during the 20th century: A modeling analysis of the influences of soil thermal dynamics

    Science.gov (United States)

    Zhuang, Q.; McGuire, A.D.; Melillo, J.M.; Clein, J.S.; Dargaville, R.J.; Kicklighter, D.W.; Myneni, R.B.; Dong, J.; Romanovsky, V.E.; Harden, J.; Hobbie, J.E.

    2003-01-01

    There is substantial evidence that soil thermal dynamics are changing in terrestrial ecosystems of the Northern Hemisphere and that these dynamics have implications for the exchange of carbon between terrestrial ecosystems and the atmosphere. To date, large-scale biogeochemical models have been slow to incorporate the effects of soil thermal dynamics on processes that affect carbon exchange with the atmosphere. In this study we incorporated a soil thermal module (STM), appropriate to both permafrost and non-permafrost soils, into a large-scale ecosystem model, version 5.0 of the Terrestrial Ecosystem Model (TEM). We then compared observed regional and seasonal patterns of atmospheric CO2 to simulations of carbon dynamics for terrestrial ecosystems north of 30??N between TEM 5.0 and an earlier version of TEM (version 4.2) that lacked a STM. The timing of the draw-down of atmospheric CO2 at the start of the growing season and the degree of draw-down during the growing season were substantially improved by the consideration of soil thermal dynamics. Both versions of TEM indicate that climate variability and change promoted the loss of carbon from temperate ecosystems during the first half of the 20th century, and promoted carbon storage during the second half of the century. The results of the simulations by TEM suggest that land-use change in temperate latitudes (30-60??N) plays a stronger role than climate change in driving trends for increased uptake of carbon in extratropical terrestrial ecosystems (30-90??N) during the recent decades. In the 1980s the TEM 5.0 simulation estimated that extratropical terrestrial ecosystems stored 0.55 Pg C yr-1. with 0.24 Pg C yr-1 in North America and 0.31 Pg C yr-1 in northern Eurasia. From 1990 through 1995 the model simulated that these ecosystems stored 0.90 Pg C yr-1, with 0.27 Pg C yr-1 stored in North America and 0.63 Pg C yr-1 stored in northern Eurasia. Thus, in comparison to the 1980s, simulated net carbon storage in the

  16. Protons from carbon ion fragmentation at 0.3–2.0 GeV/nucleon: Comparison with models of ion-ion interactions

    International Nuclear Information System (INIS)

    Yields of protons at 3.5° from carbon ion fragmentation at energies of T0 = 0.3, 0.6, 0.95, and 2.0 GeV/nucleon on a Be target were measured in the FRAGM experiment at TWA-ITEP heavy-ion facility. Proton momentum spectra cover both the region of the fragmentation maximum and the cumulative region. The differential cross sections span six orders of its magnitude. The spectra are compared with the predictions of four models of ion-ion interactions: LAQGSM03.03, SHIELD-HIT, QMD, and BC

  17. Bibliography of electron and photon cross sections with atoms and molecules published in the 20th century. Carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Makoto [Gaseous Electronics Institute, Nagoya, Aichi (Japan)

    2003-04-01

    A bibliography of original and review reports of experiments or theories of electron and photon cross sections and also electron swarm data are presented for atomic or molecular species with specified targets. These works covered 17 atoms and 51 molecules. The present bibliography is only for carbon dioxide (CO{sub 2}). About 1,240 papers were compiled. A comprehensive author index is included. The bibliography covers the period 1901 through 2000 for CO{sub 2}. Finally, author's comments for CO{sub 2} electron collision cross sections are given. (author)

  18. CVD growth of carbon nanotubes on thin-film Ni20Ti35N45 alloy catalyst

    Science.gov (United States)

    Gromov, D. G.; Pavlov, A. A.; Skorik, S. N.; Trifonov, A. Yu.; Shulyat'ev, A. S.

    2015-12-01

    The possibility of forming carbon nanotube (CNT) arrays on a Ni-Ti-N catalytic alloy with low nickel content by chemical vapor deposition (CVD) is demonstrated. Adding nitrogen to the Ni-Ti alloy composition favors the formation of TiN compound and segregation of Ni on the surface, where it produces a catalytic effect on the CNT growth. It is found that, using CVD from acetylene gas phase at a substrate temperature of 650°C, a CNT array of 9-µm height can be grown for 2 min.

  19. Bibliography of electron and photon cross sections with atoms and molecules published in the 20th century. Carbon dioxide

    International Nuclear Information System (INIS)

    A bibliography of original and review reports of experiments or theories of electron and photon cross sections and also electron swarm data are presented for atomic or molecular species with specified targets. These works covered 17 atoms and 51 molecules. The present bibliography is only for carbon dioxide (CO2). About 1,240 papers were compiled. A comprehensive author index is included. The bibliography covers the period 1901 through 2000 for CO2. Finally, author's comments for CO2 electron collision cross sections are given. (author)

  20. CO2FIX V2.0. Manual of a model for quantifying carbon sequestration in forest ecosystems and wood products

    Energy Technology Data Exchange (ETDEWEB)

    Nabuurs, G.J.; Mohren, G.M.J.; Schelhaas, M.J. [Alterra, Wageningen (Netherlands); Garza-Caligaris, J.F.; Masera, O. [Laboratorio de Bioenergia, Instituto de Ecologia Universidad Nacional Autonoma de Mexico UNAM, Mexico City (Mexico); Kanninen, M. [Centro Agronomico Tropical de Investigacion y Ensenanza CATIE, Turrialba (Costa Rica); Karjalainen, T.; Lapvetelainen, T.; Liski, J.; Pussinenn, A. [European Forest Institute EFI, Joensuu (Finland)

    2002-07-01

    CO2FIX V2.0 is a simple bookkeeping model that converts volumetric net annual increment data (and additional parameters) to annual carbon stocks and fluxes of the forest ecosystem-soil-wood products chain. It calculates at the hectare scale with time steps of one year. This version 2.0 is a hectare scale model which was improved on: the ability to simulate multi-species and uneven aged stands in multiple cohorts (e.g. selective tropical selective logging systems, and agroforestry systems); the ability to parameterize the growth also by stand density; the ability to deal with inter cohort competition; harvesting, allocation, processing lines, and end-of-life disposal of harvested wood; soil dynamics; the ability to deal with a wider variety of forest types including agro-forestry systems, selective logging systems, and post harvesting mortality; output viewing charts.

  1. The improvement by a CVD silica coating of the oxidation behaviour of a 20%Cr/25%Ni niobium stabilized stainless steel in carbon dioxide

    International Nuclear Information System (INIS)

    The improvement of the oxidation behaviour of the 20%Cr-25%Ni-Nb stabilized (20/25/Nb) austenitic stainless steel, in carbon dioxide, by a silica coating, formed by a vapour reaction upon the pre-oxidized steel surface, has been examined at 8250C. The exposure periods extended to 5975 h duration. The silica coating effectiveness increased with its thickness over the range examined, 0.5 to 27 μm. Coatings > approximately 2 μm thick reduced the extent of oxidation by at least a factor of five by providing a barrier to the diffusion of cations outwards and oxidant inwards responsible for oxide growth on the 20/25/Nb steel. In addition, they completely inhibited oxide spallation because oxidation of the steel constituents occurred primarily within the silica coating whose adherence was maintained throughout the exposure. During the prolonged heat treatment of > approximately 2 μm thick silica coated steel, the iron and nickel constituents in the precoating oxide film were reduced by solid-solid reaction with manganese and probably also chromium from the underlying steel. (author)

  2. Using atmospheric CO2 data to assess a simplified carbon-climate simulation for the 20th century

    International Nuclear Information System (INIS)

    The CSIRO biosphere model has been coupled to an atmosphere model and a simulation has been performed for the 20th century. Both biosphere and atmosphere are forced with global CO2 concentration and the atmosphere is also forced with prescribed sea surface temperatures. The simulation follows the C4MIP Phase 1 protocol. We assess the model simulation using atmospheric CO2 data. Mauna Loa growth rate is well simulated from 1980 but overestimated before that time. The interannual variations in growth rate are reasonably reproduced. Seasonal cycles are underestimated in northern mid-latitudes and are out of phase in the southern hemisphere. The north-south gradient of annual mean CO2 is substantially overestimated due to a northern hemisphere net biosphere source and a southern tropical sink. Diurnal cycles at three northern hemisphere locations are larger than observed in many months, most likely due to larger respiration than observed

  3. What metrics best reflect the energy and carbon intensity of cities? Insights from theory and modeling of 20 US cities

    International Nuclear Information System (INIS)

    Three broad approaches have emerged for energy and greenhouse gas (GHG) accounting for individual cities: (a) purely in-boundary source-based accounting (IB); (b) community-wide infrastructure GHG emissions footprinting (CIF) incorporating life cycle GHGs (in-boundary plus trans-boundary) of key infrastructures providing water, energy, food, shelter, mobility–connectivity, waste management/sanitation and public amenities to support community-wide activities in cities—all resident, visitor, commercial and industrial activities; and (c) consumption-based GHG emissions footprints (CBF) incorporating life cycle GHGs associated with activities of a sub-set of the community—its final consumption sector dominated by resident households. The latter two activity-based accounts are recommended in recent GHG reporting standards, to provide production-dominated and consumption perspectives of cities, respectively. Little is known, however, on how to normalize and report the different GHG numbers that arise for the same city. We propose that CIF and IB, since they incorporate production, are best reported per unit GDP, while CBF is best reported per capita. Analysis of input–output models of 20 US cities shows that GHGCIF/GDP is well suited to represent differences in urban energy intensity features across cities, while GHGCBF/capita best represents variation in expenditures across cities. These results advance our understanding of the methods and metrics used to represent the energy and GHG performance of cities. (letter)

  4. Carbon Dioxide, Hydrographic, and Chemical Data Obtained During the R/V Knorr Repeat Hydrography Cruise in the Atlantic Ocean: CLIVAR CO2 Sections A20_2003 (22 September-20 October 2003) and A22_2003 (23 October-13 November, 2003)

    Energy Technology Data Exchange (ETDEWEB)

    Kozyr, Alex [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Carbon Dioxide Information Analysis Center

    2008-09-30

    This report presents methods, and analytical and quality control procedures for salinity, oxygen, nutrient, inorganic carbon, organic carbon, chlorofluorocarbon (CFC), and bomb carbon-14 system parameters performed during the A20_2003 and A22_2003 cruises, which took place between September 22 and November 13, 2003, aboard research vessel (R/V) Knorr under the auspices of the National Oceanic and Atmospheric Administration (NOAA) and National Science Foundation (NSF). The R/V Knorr departed Woods Hole, Massachusetts, on September 22 for the Repeat Section A20, and ended this line in Port of Spain, Trinidad, on October 20. The Repeat Section A22 started on October 23 in Port of Spain, Trinidad, and finished on November 13, 2003, in Woods Hole, Massachusetts. The research conducted was one of a series of repeat hydrography sections jointly funded by NOAA and NSF as part of the Climate Variability Program (CLIVAR)/CO2/repeat hydrography/tracer program. Samples were taken from 36 depths at 88 stations on section A20 and 82 stations on section A22. The data presented in this report include the analyses of water samples for total inorganic carbon (TCO2), total alkalinity (TALK), dissolved organic carbon (DOC), CFC, carbon-14, hydrographic, and other chemical measurements.

  5. Laboratory Measurments of the 3.7-20 cm Wavelength Opacity of Sulfur Dioxide and Carbon Dioxide under Simulated Conditions for the Deep Atmosphere of Venus

    Science.gov (United States)

    Steffes, Paul G.; Barisich, C.

    2012-10-01

    In the past two decades, multiple observations of Venus have been made at X band (3.6 cm) using the Jansky Very Large Array (VLA) and maps have been created of the 3.6 cm emission from Venus. Since the emission morphology is related both to surface features and to deep atmospheric absorption from CO2 and SO2 (see, e.g., Butler et al., Icarus 154, 2001), knowledge of the microwave absorption properties of sulfur dioxide in a carbon dioxide atmosphere under conditions for the deep atmosphere of Venus is required for proper interpretation. Except for a single measurement campaign conducted at a single wavelength (3.2 cm) over 40 years ago (Ho et al., JGR 71, 1966), no measurements of the centimeter-wavelength properties of any Venus atmospheric constituent have been conducted under conditions characteristic of the deep atmosphere (pressures from 10-92 Bars and temperatures from 400-700 K). New measurements of the microwave properties of SO2 and CO2 at wavelengths from 3.7-20 cm are now being conducted under simulated conditions for the deep atmosphere of Venus, using a new high-pressure system. Initial results from this measurement campaign conducted at 430 K and at pressures up to 92 Bars will be presented. This work is supported by the NASA Planetary Atmospheres Program under Grant NNX11AD66G.

  6. Accelerated Carbonation Test of Concrete at 3 % and 20 % CO2 Volume Fraction%3%与20%CO2体积分数下混凝土加速碳化试验研究

    Institute of Scientific and Technical Information of China (English)

    张亚梅; 明静

    2012-01-01

    The CO2 volume fraction for accelerated carbonation test according to Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete(GB/T 50082—2009) is 20%. However, it usually lies between 2%-5% in similar international specifications. In order to compare the impact of CO2 concentration on the test results, the concrete samples with different mineral admixtures that are widely used in many infrastructures in China were prepared and accelerated carbonation test were conducted in chambers with CO2 volume fraction being 3% and 20%. Mineral admixtures used in this investigation included fly ash, ground granulated blast furnace slag and the combination of both. The carbonation depth and carbonation rate coefficient of the concrete samples were compared. It is demonstrated that the carbonation test at 3% CO2 volume fraction follows the diffusion law of CO2 in natural environment, and the carbonation resistance of the concrete with similar water-binder ratio but different mineral admixtures can be clearly distinguished, though carbonation test takes longer time. It is found that accelerated carbonation test at 20% CO2 volume fraction fails to differentiate the carbonation resistance of the concrete with similar water-binder ratio but different mineral admixtures.%选取CO2体积分数为3%和20%进行加速碳化试验,比较分析了2种情况下单掺粉煤灰、矿粉混凝土及二者复掺混凝土碳化深度及碳化速率系数随碳化龄期的变化规律.结果表明:在3%CO2体积分数下进行加速碳化试验,不但能较好地反映普通混凝土的自然碳化规律,而且能对水胶比相同矿物掺合料不同的混凝土碳化性能进行有效区分,但试验时需要适当延长碳化龄期;采用20%CO2体积分数进行加速碳化试验,并不能有效区分水胶比相同矿物掺合料不同的混凝土的碳化性能.

  7. New (p, ρ, T) data for carbon dioxide - Nitrogen mixtures from (250 to 400) K at pressures up to 20 MPa

    International Nuclear Information System (INIS)

    Highlights: → Densities of two mixtures of nitrogen and carbon dioxide are reported. → Experimental data are compared with calculated densities from the equation of state. → Experimental data agree with the equation of state for low pressures above 300 K. → The equation of state shows higher deviations than expected at high pressures. - Abstract: Comprehensive (p, ρ, T) measurements on two binary mixtures (0.10 CO2 + 0.90 N2 and 0.15 CO2 + 0.85 N2) were carried out in the gas phase at seven isotherms between (250 and 400) K and pressures up to 20 MPa using a single sinker densimeter with magnetic suspension coupling. A total of 69 (p, ρ, T) data for the first mixture and 69 (p, ρ, T) data for the second are presented in this article. The uncertainty in density was estimated to be (0.02 to 0.15)%, while the uncertainty in temperature was 3.9 mK and the uncertainty in pressure was less than 0.015% (coverage factor k = 2). Experimental results were compared with densities calculated from the GERG equation of state and with data reported by other authors for similar mixtures. Results yielded that, while deviations between experimental data and values calculated from the GERG equation were lower than 0.05% in density for low pressures, the relative error at high pressures and low temperatures increased to about (0.2 to 0.3)%. The main aim of this work was to contribute to an accurate density data base for CO2/N2 mixtures and to check or improve equations of state existing for these binary mixtures.

  8. New (p, {rho}, T) data for carbon dioxide - Nitrogen mixtures from (250 to 400) K at pressures up to 20 MPa

    Energy Technology Data Exchange (ETDEWEB)

    Mondejar, M.E.; Martin, M.C. [Grupo de Termodinamica y Calibracion (TERMOCAL), Dpto. Ingenieria Energetica y Fluidomecanica, Escuela de Ingenierias Industriales, Universidad de Valladolid, Paseo del Cauce, 59, E-47011 Valladolid (Spain); Span, R. [Lehrstuhl fuer Thermodynamik, Fakultaet fuer Maschinenbau Gebaeude IB, Ebene 5, Ruhr-Universitaet Bochum, Universitaetsstr. 150, 44780 Bochum (Germany); Chamorro, C.R., E-mail: cescha@eis.uva.es [Grupo de Termodinamica y Calibracion (TERMOCAL), Dpto. Ingenieria Energetica y Fluidomecanica, Escuela de Ingenierias Industriales, Universidad de Valladolid, Paseo del Cauce, 59, E-47011 Valladolid (Spain)

    2011-12-15

    Highlights: > Densities of two mixtures of nitrogen and carbon dioxide are reported. > Experimental data are compared with calculated densities from the equation of state. > Experimental data agree with the equation of state for low pressures above 300 K. > The equation of state shows higher deviations than expected at high pressures. - Abstract: Comprehensive (p, {rho}, T) measurements on two binary mixtures (0.10 CO{sub 2} + 0.90 N{sub 2} and 0.15 CO{sub 2} + 0.85 N{sub 2}) were carried out in the gas phase at seven isotherms between (250 and 400) K and pressures up to 20 MPa using a single sinker densimeter with magnetic suspension coupling. A total of 69 (p, {rho}, T) data for the first mixture and 69 (p, {rho}, T) data for the second are presented in this article. The uncertainty in density was estimated to be (0.02 to 0.15)%, while the uncertainty in temperature was 3.9 mK and the uncertainty in pressure was less than 0.015% (coverage factor k = 2). Experimental results were compared with densities calculated from the GERG equation of state and with data reported by other authors for similar mixtures. Results yielded that, while deviations between experimental data and values calculated from the GERG equation were lower than 0.05% in density for low pressures, the relative error at high pressures and low temperatures increased to about (0.2 to 0.3)%. The main aim of this work was to contribute to an accurate density data base for CO{sub 2}/N{sub 2} mixtures and to check or improve equations of state existing for these binary mixtures.

  9. Quantitative Estimation of Carbonate Rock Fraction in Karst Regions Using Field Spectra in 2.0–2.5 μm

    Directory of Open Access Journals (Sweden)

    Xiangjian Xie

    2016-01-01

    Full Text Available Considering the important roles of carbonate rock fraction in karst rocky desertification areas and their potential for indicating damage to vegetation, improved knowledge is desired to assess the application of spectroscopy and remote sensing to characterizing and quantifying the biophysical constituents of karst landscapes. In this study, we examined the spectra of major surface constituents in karst areas for direct evidence of absorption features attributable to carbonate rock fraction. Using spectral feature analysis with continuum removal, we observed that there are overlapping spectral absorption in 2.149–2.398 μm by soils and non-photosynthetic vegetation. These overlapping features complicated the carbonate absorption feature near 2.340 μm in synthetic mixed spectra. To remove the overprint signal, two hyperspectral carbonate rock indices (HCRIs were developed. Compared to the absorption features including depths, areas, and KRDSIs (karst rocky desertification synthesis indices, linear regression of HCRIs with carbonate rock fraction in linear synthetic mixtures resulted in higher correlations and lower errors. This study demonstrates that spectral variation of the surface constituents spectra in 2.270–2.398 μm region can indicate carbonate rock fraction and be used to quantify them. Still, additional research is needed to advance our understanding of the spectral influences from carbonate petrography relative to carbonate mineralogy, components and physical state of rock surface.

  10. Preliminary study of the impact of tritium and carbon 14 releases from the Saint-Alban nuclear power plant. CRIIRAD N.04-20 V1 Report

    International Nuclear Information System (INIS)

    After having recalled the results of previous studies on the radioactivity in surface water and land environments, and outlined the need of an investigation of the tritium and carbon 14 contamination, this report defines the objectives of this investigation, the adopted methodology (choice of plants, tritium and carbon 14 dose measurements, and sampling to study time variations). It recalls some aspects of tritium and carbon 14 releases (production of radionuclides, origins of emissions in the environment, assessments by EDF). It reports the investigation and the assessment of tritium activity in a land environment and in rain waters about the investigated site, and the investigation and the assessment of carbon 14 activity within the same environment. It reports preliminary results concerning the aquatic environment

  11. Synthesis, characterization and solubility of alkaline earth uranyl carbonates M2[UO2(CO3)3].xH20; M: Mg, Ca, Sr, Ba

    International Nuclear Information System (INIS)

    The release and dispersion of uranium from closed uranium mining sites and the resulting uranium contamination of the natural environment of such sites is a major problem examined in this dissertation. Knowledge of the pollution pathways and processes is indispensable for an assessment of the radiological implications for the human population, to be taken into account in the planning of site rehabilitation work. The formation of secondary uranium minerals may contribute to an immobilization of the uranium, but it is possible as well that such secondary uranium minerals will release uranium. A major task of this dissertation therefore was to examine the conditions of formation of alkaline earth uranyl carbonates in the context of their natural occurrence as observed at some sites, and to answer the question of whether hitherto unknown alkaline earth uranyl carbonates may form in the natural environment, and ought to be taken into account as new source terms. (orig./CB)

  12. High-temperature characteristics of 20MnB4 and 30MnB4 micro-addition cold upsetting steels and C45 and C70 high-carbon-steels

    Directory of Open Access Journals (Sweden)

    S. Sawicki

    2016-10-01

    Full Text Available The paper analyzes the high-temperature plasticity characteristics of 20MnB4 and 30MnB4 with micro-additives, intended for cold upsetting and high-carbon steels C45 and C70 in the “solid phase-liquid” during heating and cooling. The investigation was conducted to determine the plastic formability of the examined alloy under hot plastic working conditions. Experiments were carried out on the simulator Gleeble 3800 with the aim of determining the susceptibility of 20MnB4, 30MnB4, C45 and C70 steels to cracking at high temperature. The nil strength (NST, nil ductility (NDT and ductility recovery temperatures (DRT, and the fracture toughness factor and the BRT (brittleness temperature range have been determined.

  13. Test and Research of Effects of Flame Cutting and Normal Heat Treatment to Properties of 20+Cr Carbon Steel Pipe%火焰切割及正火热处理对20控Cr碳钢管性能影响试验研究

    Institute of Scientific and Technical Information of China (English)

    燕智敏; 邹平国; 那永新

    2015-01-01

    20+Cr carbon steel pipes are widely used in the pipeline of the nuclear power plant and the pipeline, which is eroded by steam, of chemical industrial furnace. The highly efficient and convenient flame cutting technology is often used in pipe matching and machining. By comparing the chemical compositions, mechanical properties and metallurgical constitution for both flame cutting and sawing on 20+Cr carbon steel pipes, it had been revealed that flame cutting will bring in several problems, such as unqualified-20 ℃impact energy, coarse grains and the segregation of ferrite and pearlite. The heat-affected zone by flame cutting will be as large as 30mm. The heat treatment experiment of normalization under temperature of 890~930℃indicated that after normalizing heat treatment,-20℃impact energy of the steel had been recovered to the normal level. In addition, the coarse grains would be refined to grain size of grade 8-9 and carbides homogeneously distributed.%20控Cr优质碳钢管广泛应用于核电站管路系统和化学工业炉上有蒸汽冲刷的管道系统,在管件加工、配管过程中不可避免地采用了高效、便捷的火焰切割方法。通过对20控Cr碳钢管在火焰切割与锯切后的化学成分、力学性能、金相试样对比发现,火焰切割将带来-20℃冲击功不满足技术要求、晶粒长大、铁素体与珠光体偏析等系列问题,火焰切割影响范围超过30 mm。正火(890~930℃)热处理校正工艺工程应用试验表明,经过正火热处理校正后,可将受到火焰切割影响的-20℃冲击功数值恢复到正常水平;同时,粗大的晶粒得以细化,晶粒度在8~9之间,碳化物分布均匀化。

  14. Relative contributions of climate change, stomatal closure, and leaf area index changes to 20th and 21st century runoff change: A modelling approach using the Organizing Carbon and Hydrology in Dynamic Ecosystems (ORCHIDEE) land surface model

    Science.gov (United States)

    Alkama, Ramdane; Kageyama, Masa; Ramstein, Gilles

    2010-09-01

    The recent evolution of continental runoff is still an open question. A related and controversial question is the attribution of this change and its consequences on our predictions of the behavior of future runoff. Here, the Land Surface Model Organizing Carbon and Hydrology in Dynamic Ecosystems is used to perform a set of transient simulations of the runoff from 1900 to 2100. We first show that the model's simulated runoff increases for the 20th century from a global point of view as well as its geographical pattern changes are close to the observations made in this paper. Moreover this trend is simulated to increase further during the 21st century under the SRES A2 scenario. We have designed a set of simulations to test the impact on global runoff evolution of three factors: climate, stomatal conductance, and vegetation growth, all sensitive to CO2 increase. A complete factor-separation analysis of the influence of these three factors and of their interactions shows that climate change largely drives the 20th and 21st century runoff increase. The other two factors (stomatal conductance and vegetation growth) play a minor role in the 20th century runoff trend but we show that these contributions increase for the 21st century simulations. Although the interactions between the factors also plays a negligible role in the 20th century global runoff increase, our results show that they become significant during the 21st century, usually reducing the direct effect of each factor. However, our study does not reveal any important negative feedback to counteract the effect of climate warming on the hydrological cycle.

  15. The 20-20-20 Airship Challenge

    Science.gov (United States)

    Kiessling, Alina; Diaz, Ernesto; Miller, Sarah; Rhodes, Jason

    2014-06-01

    A NASA Centennial Challenge; (http://www.nasa.gov/directorates/spacetech/centennial_challenges/index.html) is in development to spur innovation in stratospheric airships as a science platform. We anticipate a million dollar class prize for the first organization to fly a powered airship that remains stationary at 20km (65,000 ft) altitude for over 20 hours with a 20kg payload. The design must be scalable to longer flights with more massive payloads.In NASA’s constrained budget environment, there are few opportunities for space missions in astronomy and Earth science, and these have very long lead times. We believe that airships (powered, maneuverable, lighter-than-air vehicles) could offer significant gains in observing time, sky and ground coverage, data downlink capability, and continuity of observations over existing suborbital options at competitive prices. We seek to spur private industry (or non-profit institutions, including FFRDCs and Universities) to demonstrate the capability for sustained airship flights as astronomy and Earth science platforms. This poster will introduce the challenge in development and provide details of who to contact for more information.

  16. High Temperature Life Testing of 80Ni-20Cr Wire in a Simulated Mars Atmosphere for the Sample Analysis at Mars (SAM) Instrument Suite Gas Processing System (GPS) Carbon Dioxide Scrubber

    Science.gov (United States)

    Hoffman, Christopher; Munoz, Bruno; Gundersen, Cynthia; Thomas, Walter, III; Stephenson, Timothy

    2008-01-01

    In support of the GPS for the SAM instrument suite built by NASA/GSFC, a life test facility was developed to test the suitability of 80Ni-20Cr alloy wire, 0.0142 cm diameter, for use as a heater element for the carbon dioxide scrubber. The element would be required to operate at 1000 C in order to attain the 800 C required for regeneration of the getter. The element also would need to operate in the Mars atmosphere, which consists mostly of CO2 at pressures between 4 and 12 torr. Data on the high temperature degradation mechanism of 80Ni- 20Cr in low pressure CO2, coupled with the effects of thermal cycling, were unknown. In addition, the influence of work hardening of the wire during assembly and the potential for catastrophic grain growth also were unknown. Verification of the element reliability as defined by the mission goals required the construction of a test facility that would accurately simulate the duty cycles in a simulated Mars atmosphere. The experimental set-up, along with the test protocol and results will be described.

  17. Diamond-like carbon film on 20 CrNiMo steel prepared by hollow-cathode glow discharge%20CrNiMo钢表面空心阴极辉光放电制备类金刚石膜

    Institute of Scientific and Technical Information of China (English)

    陈飞; 陈家庆; 周海; 张跃飞

    2011-01-01

    在真空炉内以石墨为电极,利用空心阴极辉光放电在20CrNiMo上成功地沉积了类金刚石(Diamond-like carbon,DLC)薄膜.利用激光拉曼(Baman)光谱分析了所制备DLC薄膜的结构;利用原子力显微镜(AFM)分析了DLC薄膜的表面形貌;利用划痕仪测量了DLC薄膜与基体的结合力并用扫描电子显微镜(SEM)观察了划痕形貌;利用球-盘摩擦磨损实验仪对DLC薄膜的耐磨性能进行了研究.结果表明:在本实验工艺条件下沉积的类金刚石薄膜厚度约为0.6μm,薄膜均匀且致密,表面粗糙度Ra为7~8 nm.类金刚石薄膜与基体结合较紧密,临界载荷达到52 N.DLC薄膜具有优良的减摩性,20CrNiMo表面沉积DLC薄膜后摩擦系数为0.15,较20CrNiMo基体的摩擦系数0.50明显减小,耐磨性能得到提高.%Diamond-like carbon (DLC) thin film was deposited on the sudace of 20CrNiMo ahoy by hollow cathode glow discharge technique. High purity graphite was selected as the cathode and Ar as working gas. The structure of the DLC thin film was analyzed by laser Raman spectroscopy. Surface morphology of the film was observed by atomic force microscope ( AFM ). The adhesion between the DLC thin film and the substrate was investigated with scratch testing. The morphology of the scratch was observed by scanning electron microscopy(SEM). Friction and wear behavior of the DLC thin film under dry sliding against GCr15 steel was evaluated on a ball-on-disc test rig. The results show that it is feasible to prepare a DLC thin film of 0. 6 μm thick by this experimental process. The surface roughness Ra of the film is 7-8 nm. The DLC thin film has a good adhesion with critical load of 52 N by scratch testing. Excellent friction and wear-resistant behavior of the film is observed. Friction coefficient of the 20CrNiMo substrate is about 0.50 under dry sliding against steel, while the DLC thin film exhibited much lower friction coefficient of 0. 15 under the same testing condition.

  18. Rio+20

    Directory of Open Access Journals (Sweden)

    Robert Horn

    2012-10-01

    Full Text Available This reflection on Rio+20 examines many of the major social institutions and how they fulfilled their functions during the United Nations Conference on Sustainable Development at Rio. The institutions are: 1. Nation-states as a collective. 2. Individual nation-states. 3. Vanguard institutions (some NGOs. 4. Action and convening NGOs. 5. Global media. 6. Governments of nation-states acting domestically 7. Individual governments in bilateral and multilateral situations. 8. Similar institutions in different countries acting together. 9. Businesses. 10. Global science. Each is considered within the assumptions of what the society expects them to deliver (in general, what is possible for them to deliver, and what they did deliver at Rio. In approaching Rio+20, our account differs considerably from much of the reportage by the mainstream media.

  19. Modulated magnetic property, enhanced microwave absorption and Mössbauer spectroscopy of Ni0.40Zn0.40Cu0.20Fe2O4 nanoparticles embedded in carbon nanotubes

    International Nuclear Information System (INIS)

    Highlights: •Soft magnetic property of Ni0.40Zn0.40Cu0.20Fe2O4 (NZCF) has been modulated. •NZCF nanoparticles were successfully incorporated in the matrix of CNTs. •Microwave absorption of NZCF has been significantly enhanced in CNTs matrix. -- Abstract: Nanoparticles of Ni0.40Zn0.40Cu0.20Fe2O4 were prepared by sol–gel method where ultrasonication was applied to reduce the distribution of sizes as well as the agglomeration among the nanoparticles. The as dried sample was annealed at 100 and 300 °C. To modulate the soft magnetic property and also to enhance the microwave absorption in X and Ku bands of microwave frequencies, the prepared nanoparticles of each annealed sample were incorporated in the non-magnetic matrix of multi-walled carbon nanotubes (CNTs). The formation of the crystallographic phase of the bare and encapsulated samples was confirmed by X-ray diffractograms. The Raman spectra of the samples were recorded at room temperature and the observed characteristic peaks also confirmed the presence of individual component of NZCF and CNT in the nanocomposite sample. The average nanocrystallite size of NZCF sample was calculated from the broadening of the (3 1 1) peak in the XRD pattern using the Debye–Scherrer formula. The average particle size, crystallographic phase, etc., of one selected sample obtained from the high-resolution transmission electron microscopy is in good agreement with those estimated from the XRD patterns. The observed micrographs in transmission electron microscopy confirmed that the nanoparticles of NZCF were encapsulated in the matrix of CNT. The dynamic and static magnetic properties were measured by digital hysteresis loop tracer and SQUID magnetometer. Different magnetic quantities viz., saturation magnetization, coercive field, saturation to remanence ratio, etc., of the samples were also extracted and these extracted values confirmed the presence of mixed state of superparamagnetic and ferrimagnetic nanoparticles

  20. 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...

  1. A PRELIMINARY STUDY ON THE CARBON DYNAMICS OF CHINA'S TERRESTRIAL ECOSYSTEMS IN THE PAST 20 YEARS%中国陆地生态系统近20年碳空间动态的初步研究(英文)

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In this paper, we briefly review some of the research efforts that are related to the carbon balance of China. Carbon balance is characterized by the net ecosystem productivity (NEP), the difference between net primary productivity (NPP) and the heterotrophic respiration, namely the decomposition of dead organic matter by soil microbes. Direct field measurement of Rh is rare because separating root respiration (Rr) from the total soil surface CO2 efflux is very difficult.At the equilibrium state, ecosystem net primary productivity (NPP) equals Rh.The current global terrestrial ecosystems are most likely at non-equilibrium state due to various disturbances,such as fire,deforestation,and land-use change, as well as climate and atmospheric changes.At the global scale, the difference between NPP and Rh is of great interest because it indicates the capacity of terrestrial ecosystems absorbing/releasing CO2 from/to the atmosphere. We report in this paper our initial attempts towards the determination of carbon balance of China based on a new technique for estimating soil Rh. Preliminary results obtained for China's forest ecosystems are presented.%陆地生态系统的净生产力(NEP)是生态系统净初级生产力(NPP)和异氧呼吸(Rh)之差.在全球尺度上,反映NPP和Rh之差的NEP直接揭示陆地生态系统与大气系统之间的二氧化碳交换,即碳平衡,因此,意义重大.文章简短回顾了关于中国陆地生态系统碳平衡的研究状况.由于植物根部呼吸很难从土壤表面总二氧化碳(CO2)通量中分开,因此直接从野外测量土壤异氧呼吸几乎是不可能的.虽然由于像诸如火灾、森林砍伐、土地利用变化及气候和大气变化等干扰因素,全球陆地生态系统很大程度上处于非平衡态,利用生态系统在平衡态时NPP等于Rh这一事实,我们估算了全球和中国森林生态系统的土壤异氧呼吸.利用遥感和地面的NPP观测数据,我们也估算了中国森林生

  2. Carbonation on ternary cement systems

    OpenAIRE

    Martínez Ramírez, Sagrario; Fernández Carrasco, Lucía

    2012-01-01

    The main hydration reaction product in the ternary system fly ash, calcium sulphate and calcium aluminate cement (40/20/40) at 20°C is a hydrated calcium sulfoaluminate compound, an AFt phase slightly different from “traditional ettringite”. The carbonation of ettringite develops gypsum but in this case rapidcreekite is formed. For the first time it has been observed that carbonation of the mentioned calcium sulfoaluminate compound (AFt), an hydrated calcium sulphate carbonated phase (Ca2(SO4...

  3. Ab-initio computation of electronic, and transport properties of wurtzite aluminum nitride (W-AlN) and microwave absorption properties of multi-walled carbon nanotubes (outer diameter 20-30 nanometers)-epoxy composites

    Science.gov (United States)

    Nwigboji, Ifeanyi Humphrey

    In Section I, We report findings from several ab-initio, self-consistent calculations of electronic and transport properties of wurtzite aluminum nitride (w-AlN). Our calculations utilized a local density approximation (LDA) potential and the linear combination of Gaussian orbitals (LCGO). Unlike some other density functional theory (DFT) calculations, we employed the Bagayoko, Zhao, and Williams' method, enhanced by Ekuma and Franklin (BZW-EF). The BZW-EF method verifiably leads to the minima of the occupied energies; these minima, the low laying unoccupied energies, and related wave functions provide the most variationally and physically valid density functional theory (DFT) description of the ground states of materials under study. With multiple oxidation states of Al (Al3+ to Al) and the availability of N3- to N, the BZW-EF method required several sets of self-consistent calculations with different ionic species as input. The binding energy for (Al3+ & N3-) as input was 1.5 eV larger in magnitude than those for other input choices; the results discussed here are those from the calculation that led to the absolute minima of the occupied energies with this input. Our calculated, direct band gap for w-AlN, at the Gamma point, is 6.28 eV, in excellent agreement with the 6.28 eV experimental value at 5K. We discuss the bands, total and partial densities of states, and calculated, effective masses. In section II, multi-walled carbon nanotubes (MWCNTs)-epoxy composites with MWCNTs of outer diameters (OD) of 20-30nm was fabricated. The MWCNT loadings in the composites were controlled from 1-10 wt. %. An Agilent PNA Network analyzer was utilized in the measurements of microwave absorption (MA) properties of these MWCNTs-epoxy composites over a wide frequency range of 1-26.5GHz.The measurement results showed that MA strongly depends on MWCNTs loadings in the composites. In addition, the microwave reflection, transmission, and dielectric permittivity of the MWCNTs

  4. 20 CFR 602.20 - Organization.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Organization. 602.20 Section 602.20 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR QUALITY CONTROL IN THE FEDERAL-STATE UNEMPLOYMENT INSURANCE SYSTEM State Responsibilities § 602.20 Organization. Each State shall establish a...

  5. Fragmentation in Carbon Therapy Beams

    CERN Document Server

    Charara, Y M

    2010-01-01

    The state of the art Monte Carlo code HETC-HEDS was used to simulate spallation products, secondary neutron, and secondary proton production in A-150 Tissue Equivalent Plastic phantoms to investigate fragmentation of carbon therapy beams. For a 356 MeV/Nucleon carbon ion beam, production of charged particles heavier than protons was 0.24 spallation products per incident carbon ion with atomic numbers ranging from 1 through 5 (hydrogen to boron). In addition, there were 4.73 neutrons and 2.95 protons produced per incident carbon ion. Furthermore, as the incident energy increases, the neutron production rate increases at a rate of 20% per 10 MeV/nucleon. Secondary protons were created at a rate between 2.62-2.87 per carbon ion, while spallation products were created at a rate between 0.20-0.24 per carbon ion.

  6. Metal incorporation into nanoporous carbon

    OpenAIRE

    Henley, SJ; Woolger, NEP; Carey, JD; Silva, SRP; Fuge, GM; Ashfold, MNR

    2005-01-01

    Nanoporous carbon films were deposited by 248 nm pulsed laser ablation of a graphite target in different background pressures of argon (P). The morphology changed from smooth, high-density amorphous carbon films at P = 20 mTorr to ultra-low density nanoporous material at P = 380 mTorr. Subsequently, the nanostructural, chemical and electrical properties of metal containing nanoporous carbon samples were investigated by ablating graphite targets containing known contents of Ni and Co. We demon...

  7. 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.

  8. Microbially mediated mineral carbonation

    Science.gov (United States)

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

    2010-12-01

    implemented and economically efficient alternative to other technologies currently under development for mineral sequestration. Dismukes GC, Carrieri D, Bennette N, Ananyev GM, Posewitz MC (2008) Aquatic phototrophs: efficient alternatives to land-based crops for biofuels. Current Opinion in Biotechnology, 19, 235-240. Ferris FG, Wiese RG, Fyfe WS (1994) Precipitation of carbonate minerals by microorganisms: Implications of silicate weathering and the global carbon dioxide budget. Geomicrobiology Journal, 12, 1-13. Lackner KS, Wendt CH, Butt DP, Joyce EL, Jr., Sharp DH (1995) Carbon dioxide disposal in carbonate minerals. Energy, 20, 1153-1170. Power IM, Wilson SA, Thom JM, Dipple GM, Gabites JE, Southam G (2009) The hydromagnesite playas of Atlin, British Columbia, Canada: A biogeochemical model for CO2 sequestration. Chemical Geology, 206, 302-316. Thompson JB, Ferris FG (1990) Cyanobacterial precipitation of gypsum, calcite, and magnesite from natural alkaline lake water. Geology, 18, 995-998.

  9. Conducting carbonized polyaniline nanotubes

    Czech Academy of Sciences Publication Activity Database

    Mentus, S.; Ciric-Marjanovic, G.; Trchová, Miroslava; Stejskal, Jaroslav

    2009-01-01

    Roč. 20, č. 24 (2009), 245601/1-245601/10. ISSN 0957-4484 R&D Projects: GA ČR GA203/08/0686; GA AV ČR IAA400500905 Institutional research plan: CEZ:AV0Z40500505 Keywords : conducting polymers * polyaniline * carbonization Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.137, year: 2009

  10. The 20-20-20 Package: European Union Ets recommendations

    International Nuclear Information System (INIS)

    By analysing both the major provisions of the new Ets Directive and the preliminary results concerning the sectors' exposition to the risk of Carbon Leakage, this article describes which improvements and inefficiencies will characterize the Emission Trading Scheme during its post-Kyoto trading period (2013-2020).

  11. The 20-20-20 Airships NASA Centennial Challenge

    Science.gov (United States)

    Kiessling, Alina; Diaz, Ernesto; Rhodes, Jason; Ortega, Sam; Eberly, Eric

    2015-08-01

    A 2013 Keck Institute for Space Studies (KISS) study examined airships as a possible platform for Earth and space science. Airships, lighter than air, powered, maneuverable vehicles, could offer significant gains in observing time, sky and ground coverage, data downlink capability, and continuity of observations over existing suborbital options at competitive prices. The KISS study recommended three courses of action to spur the development and use of airships as a science platform. One of those recommendations was that a prize competition be developed to demonstrate a stratospheric airship. Consequently, we have been developing a NASA Centennial Challenge; (www.nasa.gov/challenges) to spur innovation in stratospheric airships as a science platform. We anticipate a multi-million dollar class prize for the first organization to fly a powered airship that remains stationary at 20km (65,000 ft) altitude for over 20 hours with a 20kg payload. The design must be scalable to longer flights with more massive payloads. A second prize tier, for a 20km flight lasting 200 hours with a 200kg payload would incentivize a further step toward a scientifically compelling and viable new platform. This technology would also have broad commercial applications including communications, asset tracking, and surveillance. Via the 20-20-20 Centennial Challenge, we are seeking to spur private industry (or non-profit institutions, including Universities) to demonstrate the capability for sustained airship flights as astronomy and Earth science platforms.

  12. Sc20C60: a volleyballene

    Science.gov (United States)

    Wang, Jing; Ma, Hong-Man; Liu, Ying

    2016-06-01

    An exceptionally stable hollow cage containing 20 scandium atoms and 60 carbon atoms has been identified. This Sc20C60 molecular cluster has a Th point group symmetry and a volleyball-like shape that we refer to below as ``Volleyballene''. Electronic structure analysis shows that the formation of delocalized π bonds between Sc atoms and the neighboring pentagonal rings made of carbon atoms is crucial for stabilizing the cage structure. A relatively large HOMO-LUMO gap (~1.4 eV) was found. The results of vibrational frequency analysis and molecular dynamics simulations both demonstrate that this Volleyballene molecule is exceptionally stable.An exceptionally stable hollow cage containing 20 scandium atoms and 60 carbon atoms has been identified. This Sc20C60 molecular cluster has a Th point group symmetry and a volleyball-like shape that we refer to below as ``Volleyballene''. Electronic structure analysis shows that the formation of delocalized π bonds between Sc atoms and the neighboring pentagonal rings made of carbon atoms is crucial for stabilizing the cage structure. A relatively large HOMO-LUMO gap (~1.4 eV) was found. The results of vibrational frequency analysis and molecular dynamics simulations both demonstrate that this Volleyballene molecule is exceptionally stable. Electronic supplementary information (ESI) available: Sc20C60: a Volleyballene_SI. See DOI: 10.1039/c5nr07784b

  13. 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.

  14. 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.

  15. 28 CFR 20.20 - Applicability.

    Science.gov (United States)

    2010-07-01

    ... history record information for purposes of international travel, such as issuing visas and granting of... History Record Information Systems § 20.20 Applicability. (a) The regulations in this subpart apply to all State and local agencies and individuals collecting, storing, or disseminating criminal history...

  16. A Study of Different Doped Metal Cations on the Physicochemical Properties and Catalytic Activities of Ce20 M1 Ox (M=Zr, Cr, Mn, Fe, Co, Sn) Composite Oxides for Nitric Oxide Reduction by Carbon Monoxide.

    Science.gov (United States)

    Deng, Changshun; Li, Min; Qian, Junning; Hu, Qun; Huang, Meina; Lin, Qingjin; Ruan, Yongshun; Dong, Lihui; Li, Bin; Fan, Minguang

    2016-08-01

    This work is mainly focused on investigating the effects of different doped metal cations on the formation of Ce20 M1 Ox (M=Zr, Cr, Mn, Fe, Co, Sn) composite oxides and their physicochemical and catalytic properties for NO reduction by CO as a model reaction. The obtained samples were characterized by using N2 physisorption, X-ray diffraction, laser Raman spectroscopy, UV/Vis diffuse reflectance spectroscopy, inductively coupled plasma atomic emission spectroscopy, X-ray photoelectron spectroscopy, temperature-programmed reduction by hydrogen and by oxygen (H2 -TPR and O2 -TPD), in situ diffuse reflectance infrared Fourier transform spectroscopy, and the NO+CO model reaction. The results imply that the introduction of M(x+) into the lattice of CeO2 increases the specific surface area and pore volume, especially for variable valence metal cations, and enhances the catalytic performance to a great extent. In this regard, increases in the oxygen vacancies, reduction properties, and chemisorbed O2 (-) (and/or O(-) ) species of these Ce20 M1 Ox composite oxides (M refers to variable valence metals) play significant roles in this reaction. Among the samples, Ce20 Cr1 Ox exhibited the best catalytic performance, mainly because it has the best reducibility and more chemisorbed oxygen, and significant reasons for these attributes may be closely related to favorable synergistic interactions of the vacancies and near-surface Ce(3+) and Cr(3+) . Finally, a possible reaction mechanism was tentatively proposed to understand the reactions. PMID:27435470

  17. 40 CFR 89.320 - Carbon monoxide analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Carbon monoxide analyzer calibration... Test Equipment Provisions § 89.320 Carbon monoxide analyzer calibration. (a) Calibrate the NDIR carbon... introduction into service and annually thereafter, the NDIR carbon monoxide analyzer shall be checked...

  18. Contributions for the 6th London international conference on carbon and graphite CARBON 82

    International Nuclear Information System (INIS)

    This report is the compilation of a number of papers prepared by KFA Juelich GmbH for the Sixth London International Conference on Carbon and Graphite CARBON '82 which will be held at London in the Imperial College, 20-24 September, 1982. The presentations deal with objectives of manufacture, nuclear application and reactivity of carboneous materials. (orig./GSCH)

  19. Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the JAMES CLARK ROSS in the South Atlantic Ocean from 1995-03-20 to 1995-05-06 (NODC Accession 0114999)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0114999 includes chemical, discrete sample, physical and profile data collected from JAMES CLARK ROSS in the South Atlantic Ocean from 1995-03-20 to...

  20. Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the ATLANTIS II in the North Atlantic Ocean from 1989-04-20 to 1989-06-06 (NODC Accession 0113522)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113522 includes chemical, discrete sample, physical and profile data collected from ATLANTIS II in the North Atlantic Ocean from 1989-04-20 to...

  1. 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.

  2. The research of a method for determination of total carbon, combination carbon and free carbon in beryllium metal

    International Nuclear Information System (INIS)

    A method for determination of total carbon, combination carbon and free carbon in beryllium metal with LECO CS-344 carbon/sulphur determinant has been studied. Tungsten-copper mixed pellets are used as flux to the determination of total carbon. Ratio of weight of the flux to the sample is greater than 20:1. Good analytical results are got. By this method the relative standard deviation is <10% when the content of total carbon in the range of 0.050%∼0.080% in beryllium. A standard steel sample of carbon is added into beryllium, the recoveries are 94%∼106%. For determination of free carbon, the sample are decomposed with 3 mol/L HCl, filtered and followed determination. By this method the relative standard deviation is ≤10% when the content of free carbon in the range of 0.006%∼0.020% in beryllium. the balance of total carbon and free carbon is equal to combination carbon. The method is used to determine the sample of content of total carbon in the range of 0.050%∼1.00%, free carbon in the range of 0.006%∼0.500% in metal beryllium. (6 refs., 1 fig., 13 tabs.)

  3. Australian G20 Presidency

    OpenAIRE

    Andrei G. Sakharov; Andrei V. Shelepov; Elizaveta A. Safonkina; Mark R. Rakhmangulov

    2015-01-01

    The 2014 Australian presidency took place against the backdrop of multiple challenges in both global economy and international politics, with Ukrainian crisis, Syrian conflict, Islamic State, and Ebola. Thus, despite being an economic forum, the G20 could not avoid addressing these issues, with discussions taking place during the bilateral meetings and on the sidelines of the forum. The article attempts to analyze the Australian G20 Presidency within a functional paradigm, assessing G20 perfo...

  4. Web 2.0

    CERN Document Server

    Han, Sam

    2012-01-01

    Web 2.0 is a highly accessible introductory text examining all the crucial discussions and issues which surround the changing nature of the World Wide Web. It not only contextualises the Web 2.0 within the history of the Web, but also goes on to explore its position within the broader dispositif of emerging media technologies.The book uncovers the connections between diverse media technologies including mobile smart phones, hand-held multimedia players, ""netbooks"" and electronic book readers such as the Amazon Kindle, all of which are made possible only by the Web 2.0. In addition, Web 2.0 m

  5. Variations in carbon emissions from vehicles at signalised intersections

    OpenAIRE

    Ing, Koh

    2011-01-01

    Carbon emissions from road transport make up 20% of the total greenhouse gas emissions in the UK. Therefore, reducing carbon emissions from road transport is significant in reaching carbon reduction targets. In urban areas where signal controlled intersections are common, carbon emissions from vehicular traffic can be aggravated by aggressive driving and interruptions induced by traffic control. Considerable variations in speed and acceleration profiles could be observed between high carbon a...

  6. 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 ...

  7. 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.

  8. Powernext, newsletter no.20

    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 May 2004. (A.L.B.)

  9. 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.

  10. Protect Yourself from Carbon Monoxide Poisoning

    Centers for Disease Control (CDC) Podcasts

    2007-11-20

    Learn about carbon monoxide - a colorless, odorless gas - and how to protect yourself and your family.  Created: 11/20/2007 by CDC National Center for Environmental Health.   Date Released: 12/4/2007.

  11. Carbon dioxide gasification of carbon black: isotope study of carbonate catalysis

    International Nuclear Information System (INIS)

    Temperature-programmed reaction was used with labeled isotopes (13C and 18O) to study interactions between carbon black and potassium carbonate in pure He and 10% CO2/90% He atmospheres. Catalytic gasification precursor complexes were observed. Carbon and oxygen-bearing carbon surface groups interacted with the carbonate above 500 K to form surface complexes. Between 500 and 950 K, and in the presence of gaseous CO2, the complexes participated in C and O exchange with the gas phase while oxygen atoms within the complexes also exchanged with those on the carbon surface. As the temperature rose, the complexes decomposed, with CO2 the initial product. Decomposition started around 500 K in pure He, and around 950 K in CO2/He. Catalytic gasification began only after decomposition of significant portions of the complexes. Elemental potassium formed, and the active catalyst appears to alternate between being potassium metal and a potassium-oxygen-carbon complex. Potassium carbonate is not part of the catalytic cycle. 20 references, 10 figures

  12. ARLearn 2.0

    NARCIS (Netherlands)

    Ternier, Stefaan; Tabuenca, Bernardo; Klemke, Roland; Specht, Marcus

    2013-01-01

    Ternier, S., Tabuenca, B., Klemke, R., & Specht, M. (2012). ARLearn (version 2.0) [Software]. Heerlen, The Netherlands: Open Universiteit. Available under the GNU Lesser General Public License (LGPL3)

  13. Carbon particles

    Science.gov (United States)

    Hunt, Arlon J.

    1984-01-01

    A method and apparatus whereby small carbon particles are made by pyrolysis of a mixture of acetylene carried in argon. The mixture is injected through a nozzle into a heated tube. A small amount of air is added to the mixture. In order to prevent carbon build-up at the nozzle, the nozzle tip is externally cooled. The tube is also elongated sufficiently to assure efficient pyrolysis at the desired flow rates. A key feature of the method is that the acetylene and argon, for example, are premixed in a dilute ratio, and such mixture is injected while cool to minimize the agglomeration of the particles, which produces carbon particles with desired optical properties for use as a solar radiant heat absorber.

  14. 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...... corporations construing themselves as able and suitable to manage their emissions, and, additionally, given that the construction of carbon emissions has performative consequences, the underlying practices need to be declassified, i.e. opened for public scrutiny. Hence the paper concludes by arguing for a...

  15. Esterification of glycerol from biodiesel production to glycerol carbonate in non-catalytic supercritical dimethyl carbonate.

    Science.gov (United States)

    Ilham, Zul; Saka, Shiro

    2016-01-01

    Conversion of glycerol from biodiesel production to glycerol carbonate was studied by esterification with dimethyl carbonate in a non-catalytic supercritical condition. It was found that in a non-catalytic supercritical condition, glycerol at higher purity gave higher yield of glycerol carbonate at 98 wt% after reaction at 300 °C/20-40 MPa/15 min. The yield of glycerol carbonate was observed to increase with molar ratio, temperature, pressure and time until a certain equilibrium limit. The existence of impurities such as water and remnants of alkaline catalyst in crude glycerol will direct the reaction to produce glycidol. Although impurities might not be desirable, the non-catalytic supercritical dimethyl carbonate could be an alternative method for conversion of glycerol from biodiesel production to value-added glycerol carbonate.Graphical abstractPlausible reaction scheme for conversion of glycerol to glycerol carbonate in non-catalytic supercritical dimethyl carbonate. PMID:27386367

  16. 20-125 mev/nuc cosmic ray carbon nuclei intensities between 2004-2010 in solar cycle #23 as measured near the earth, at voyager 2 and also in the heliosheath at voyager 1 - modulation in a two zone heliospehre

    CERN Document Server

    Webber, W R; Stone, E C; McDonald, F B; Mewaldt, R A; Leske, R; Wiedenbeck, M; Higbie, P R; Heikkila, B

    2012-01-01

    The recovery of cosmic ray Carbon nuclei of energy ~20-125 MeV/nuc in solar cycle #23 from 2004 to 2010 has been followed at three locations, near the Earth using ACE data and at V2 between 74-92 AU and also at V1 beyond the heliospheric termination shock at between 91-113 AU. To describe the observed intensity changes and to predict the absolute intensities measured at all three locations we have used a simple spherically symmetric (no drift) two-zone heliospheric transport model with specific values for the diffusion coefficient in both the inner and outer zones. The diffusion coefficient in the outer zone is determined to be ~5-10 times smaller than that in the inner zone out to 90 AU. For both V1 and V2 the calculated C nuclei intensities agree within an average of \\pm 10% with the observed intensities. Because of this agreement between V1 and V2 observations and predictions there is no need to invoke an asymmetrical squashed heliosphere or other effects to explain the V2 intensities relative to V1 as is ...

  17. 46 CFR 72.20-20 - Sleeping accommodations.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Sleeping accommodations. 72.20-20 Section 72.20-20... ARRANGEMENT Accommodations for Officers and Crew § 72.20-20 Sleeping accommodations. (a) Where practicable, each licensed officer shall be provided with a separate stateroom. (b) Sleeping accommodations for...

  18. 46 CFR 92.20-20 - Sleeping accommodations.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Sleeping accommodations. 92.20-20 Section 92.20-20... CONSTRUCTION AND ARRANGEMENT Accommodations for Officers and Crew § 92.20-20 Sleeping accommodations. (a) Where practicable, each licensed officer must be provided with a separate stateroom. (b) Sleeping accommodations...

  19. 46 CFR 190.20-20 - Sleeping accommodations.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Sleeping accommodations. 190.20-20 Section 190.20-20... CONSTRUCTION AND ARRANGEMENT Accomodations for Officers, Crew, and Scientific Personnel § 190.20-20 Sleeping...) Sleeping accommodations for the crew must be divided into rooms, no one of which must berth more than...

  20. 46 CFR 58.20-20 - Refrigeration piping.

    Science.gov (United States)

    2010-10-01

    ... systems shall be designed in accordance with ANSI B31.5 (incorporated by reference; see 46 CFR 58.03-1... 46 Shipping 2 2010-10-01 2010-10-01 false Refrigeration piping. 58.20-20 Section 58.20-20 Shipping... AND RELATED SYSTEMS Refrigeration Machinery § 58.20-20 Refrigeration piping. (a) All piping...

  1. 40 CFR 60.263 - Standard for carbon monoxide.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for carbon monoxide. 60.263... Production Facilities § 60.263 Standard for carbon monoxide. (a) On and after the date on which the... furnace any gases which contain, on a dry basis, 20 or greater volume percent of carbon...

  2. Nanostructural activated carbons for hydrogen storage

    Science.gov (United States)

    Li, Suoding

    A series of nanostructured activated carbons have been synthesized from poly(ether ether ketone) (PEEK), and its derivatives. These carbons, with surface area exceeding 3000 m2/g and with average pore diameters of ≤ 20 A, are proven to be superior hydrogen storage materials, with hydrogen storage capacities up to 5.5 wt% at 77 K and 45 atm. The porous texture of these carbons was controlled via optimizing three synthetic steps: thermo-oxidation of PEEK in air, pyrolysis or carbonization of the oxidized PEEK in an inert atmosphere, and activation of the pre-carbonized PEEK with metal hydroxide. Thermo-oxidation of PEEK and carbonization process were thoroughly studied. These processes have been investigated by MDSC, FTIR, TGA and Py-MS. The pyrolysis or carbonization of PEEK involves the degradation of PEEK chains in three stages. Carbon morphology, including crystallinity and porous texture, is readily controlled by adjusting carbonization temperature. Activation of PEEK carbons, using inorganic bases and other activation agents, produces microporous carbons having a very narrow pore size distribution and an average pore diameter of ≤ 20 A. The activation control parameters including activation agent, activation temperature, time and carbon morphology have been investigated extensively. High surface area activated carbon is obtained by activating a highly amorphous carbon with a high activation agent/carbon ratio at 800°C. Theoretical calculations show that the pores with smaller diameter, especially smaller than 7 A, favor hydrogen adsorption. The experimental results confirm this fact and show that: (1) the hydrogen adsorption capacity per unit surface area at 77 K and 1 bar is larger in the smaller pores, (2) gravimetric hydrogen storage capacity (W(H2)) is directly proportional to the ultramicropore (< 7 A) volume; and (3) the volumetric hydrogen storage capacity is directly proportional to the volume fraction of ultramicropores in carbon. Hydrogen

  3. TYPE Ia SUPERNOVA CARBON FOOTPRINTS

    International Nuclear Information System (INIS)

    We present convincing evidence of unburned carbon at photospheric velocities in new observations of five Type Ia supernovae (SNe Ia) obtained by the Nearby Supernova Factory. These SNe are identified by examining 346 spectra from 124 SNe obtained before +2.5 days relative to maximum. Detections are based on the presence of relatively strong C II λ6580 absorption 'notches' in multiple spectra of each SN, aided by automated fitting with the SYNAPPS code. Four of the five SNe in question are otherwise spectroscopically unremarkable, with ions and ejection velocities typical of SNe Ia, but spectra of the fifth exhibit high-velocity (v > 20, 000 km s–1) Si II and Ca II features. On the other hand, the light curve properties are preferentially grouped, strongly suggesting a connection between carbon-positivity and broadband light curve/color behavior: three of the five have relatively narrow light curves but also blue colors and a fourth may be a dust-reddened member of this family. Accounting for signal to noise and phase, we estimate that 22+10–6% of SNe Ia exhibit spectroscopic C II signatures as late as –5 days with respect to maximum. We place these new objects in the context of previously recognized carbon-positive SNe Ia and consider reasonable scenarios seeking to explain a physical connection between light curve properties and the presence of photospheric carbon. We also examine the detailed evolution of the detected carbon signatures and the surrounding wavelength regions to shed light on the distribution of carbon in the ejecta. Our ability to reconstruct the C II λ6580 feature in detail under the assumption of purely spherical symmetry casts doubt on a 'carbon blobs' hypothesis, but does not rule out all asymmetric models. A low volume filling factor for carbon, combined with line-of-sight effects, seems unlikely to explain the scarcity of detected carbon in SNe Ia by itself.

  4. Investigation of Structure and Oxidation Behavior of Pitch and Resin Resultant Carbon

    Institute of Scientific and Technical Information of China (English)

    ZHUBo-quan; LINan

    1996-01-01

    The structure and oxidation behaviors of pitch carbon,resin carbon and their mixture re-sultant carbon have been investigated.The results indicate that the pitch carbon has relative higher true specific gravity,well developed crystalline and better oxidation resistance than resin carbon,With 20%-35% resin added to pitch,the structure of the resultant carbon can be modified and oxidation resistance will be improved significantly.

  5. Carbon sequestration in European croplands.

    Science.gov (United States)

    Smith, Pete; Falloon, Pete

    2005-01-01

    The Marrakech Accords allow biospheric carbon sinks and sources to be included in attempts to meet emission reduction targets for the first commitment period of the Kyoto Protocol. Forest management, cropland management, grazing land management, and re-vegetation are allowable activities under Article 3.4 of the Kyoto Protocol. Soil carbon sinks (and sources) can, therefore, be included under these activities. Croplands are estimated to be the largest biospheric source of carbon lost to the atmosphere in Europe each year, but the cropland estimate is the most uncertain among all land-use types. It is estimated that European croplands (for Europe as far east as the Urals) lose 300 Tg (C) per year, with the mean figure for the European Union estimated to be 78 Tg (C) per year (with one SD=37). National estimates for EU countries are of a similar order of magnitude on a per-area basis. There is significant potential within Europe to decrease the flux of carbon to the atmosphere from cropland, and for cropland management to sequester soil carbon, relative to the amount of carbon stored in cropland soils at present. The biological potential for carbon storage in European (EU 15) cropland is of the order of 90-120 Tg (C) per year, with a range of options available that include reduced and zero tillage, set-aside, perennial crops, deep rooting crops, more efficient use of organic amendments (animal manure, sewage sludge, cereal straw, compost), improved rotations, irrigation, bioenergy crops, extensification, organic farming, and conversion of arable land to grassland or woodland. The sequestration potential, considering only constraints on land use, amounts of raw materials and available land, is up to 45 Tg (C) per year. The realistic potential and the conservative achievable potentials may be considerably lower than the biological potential because of socioeconomic and other constraints, with a realistically achievable potential estimated to be about 20% of the

  6. Sinter ageing of equiatomic Al20Co20Cu20Zn20Ni20 high entropy alloy via mechanical alloying

    International Nuclear Information System (INIS)

    The present investigation reports for the first time, the sinter ageing of equiatomic Al20Co20Cu20Ni20Zn20 high entropy alloy (HEA), being synthesized by high energy ball milling of elemental powder blend under protective argon atmosphere, followed by consolidation of the milled powder by spark plasma sintering at different temperatures and applied pressure of 50 MPa. The detailed X-ray diffraction and transmission electron microscopy (TEM) studies indicate the presence of single phase, FCC β supersaturated solid solution in the ball milled powder. However, the sintering of the as-milled powder reveals the formation of α with ordered FCC (L12) structure within the grains of FCC γ. The microstructural analysis using TEM shows the precipitation of near cuboidal shaped α phase within the grains of γ. The size and shape of the precipitates depend on the sintering temperature. Hardness measurement of the sintered alloys suggests age hardening of the as-milled powder during sintering. The sinter age hardening of HEA is attributed to the fine scale precipitation of α phase. Detailed variation of the hardness and microstructural evolution are reported here to elucidate this novel finding

  7. Biosynthesis of glycerol carbonate from glycerol by lipase in dimethyl carbonate as the solvent.

    Science.gov (United States)

    Lee, Kyung Hwa; Park, Chang-Ho; Lee, Eun Yeol

    2010-11-01

    Glycerol carbonate was synthesized from renewable glycerol and dimethyl carbonate using lipase in solvent-free reaction system in which excess dimethyl carbonate played as the reaction medium. A variety of lipases have been tested for their abilities to catalyze transesterification reaction, and Candida antartica lipase B and Novozyme 435 exhibited higher catalytic activities. The silica-coated glycerol with a 1:1 ratio was supplied to prevent two-phase formation between hydrophobic dimethyl carbonate and hydrophilic glycerol. Glycerol carbonate was successfully synthesized with more than 90% conversion from dimethyl carbonate and glycerol with a molar ratio of 10 using Novozyme 435-catalyzed transesterification at 70 °C. The Novozyme 435 [5% (w/w) and 20% (w/w)] and silica gel were more than four times recycled with good stability in a repeated batch operation for the solvent-free synthesis of glycerol carbonate. PMID:20502921

  8. Carbon accumulation in arid croplands of northwest China: pedogenic carbonate exceeding organic carbon

    Science.gov (United States)

    Wang, Xiujun; Wang, Jiaping; Xu, Minggang; Zhang, Wenju; Fan, Tinglu; Zhang, Juan

    2015-06-01

    Soil carbonate (SIC) exceeds organic carbon (SOC) greatly in arid lands, thus may be important for carbon sequestration. However, field data for quantifying carbonate accumulation have been lacking. This study aims to improve our understanding of SIC dynamics and its role in carbon sequestration. We analyzed two datasets of SOC and SIC and their 13C compositions , one with over 100 soil samples collected recently from various land uses in the Yanqi Basin, Xinjiang, and the other with 18 archived soil samples from a long-term experiment (LTE) in Pingliang, Gansu. The data from the Yanqi Basin showed that SOC had a significant relationship with SIC and pedogenic carbonate (PIC); converting shrub land to cropland increased PIC stock by 5.2 kg C m-2, which was 3.6 times of that in SOC stock. The data from the LTE showed greater accumulation of PIC (21-49 g C m-2 year-1) than SOC (10-39 g C m-2 year-1) over 0-20 cm. Our study points out that intensive cropping in the arid and semi-arid regions leads to an increase in both SOC and PIC. Increasing SOC through straw organic amendments enhances PIC accumulation in the arid cropland of northwestern China.

  9. Preparation of hollow spherical carbon nanocages

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, C.-K.; Kang, H. Y.; Hong, C.-I; Huang, C.-H.; Chang, F.-C.; Wang, H. Paul, E-mail: wanghp@mail.ncku.edu.tw [National Cheng Kung University, Department of Environmental Engineering, Taiwan (China)

    2012-12-15

    This study presents a new and simple method for the synthesis of hollow carbon spheres possessing nanocage sizes of 7.1, 14, and 20 nm in diameter. The core-shell (i.e., Cu-C) nanoparticles prepared by carbonization of the Cu{sup 2+}-cyclodextrin (CD) complexes at 573 K for 2 h was etched with HCl (6N) to yield the hollow carbon spheres. The carbon-shell of the hollow carbon nanospheres, which consisted of mainly diamond-like and graphite carbons, is not perturbed during etching. In addition to the nanocages, the hollow carbon nanospheres also possess micropores with an opening of 0.45 nm, allowing small molecules to diffuse in and out through the carbon-shell. Many elements (such as Zn{sup 2+} or Cu{sup 2+}) can therefore be filled into the nanocages of the hollow carbon nanospheres. With these unique properties, for instance, designable active species such as Cu and ZnO encapsulated in the carbon-shell can act as Cu-ZnO-C yolk-shell nanoreactors which are found very effective in the catalytic decomposition of methanol.

  10. Carbon Footprints

    OpenAIRE

    Rahel Aichele; Gabriel Felbermayr

    2011-01-01

    Lässt sich der Beitrag eines Landes zum weltweiten Klimaschutz an der Veränderung seines CO2-Ausstoßes messen, wie es im Kyoto-Abkommen implizit unterstellt wird? Oder ist aufgrund der Bedeutung des internationalen Güterhandels der Carbon Footprint – der alle CO2-Emissionen erfasst, die durch die Absorption (d.h. Konsum und Investitionen) eines Landes entstehen – das bessere Maß? Die Autoren erstellen eine Datenbank mit den Footprints von 40 Ländern für den Zeitraum 1995–2007. Die deskriptive...

  11. LAPSI 2.0

    DEFF Research Database (Denmark)

    Lundqvist, Björn; Forsberg, Yrsa; de Vries, Marc;

    availability of PSI. In fact, Article 6 of the PSI Directive imposes, as the general rule, marginal cost, as the ceiling, for what fees may be obtained by the Public Sector Bodies (PSBs). Interestingly, lately incumbent market players have been submitting claims that this change of policy is in fact illicit...... governments throughout Europe and in fact frustrate the sound application of the PSI Directive. A possible collision of the PSI Directive and European competition (law) principles – The LAPSI 2.0 Network has adopted it as the subject of a position paper under WP 3 (IP and competition law). The paper will...

  12. Carbon footprint of milk from sheep farming systems in northern Spain including soil carbon sequestration in grasslands

    DEFF Research Database (Denmark)

    Batalla, Inma M.; Knudsen, Marie Trydeman; Mogensen, Lisbeth; Hierro, O.; Pinto, M.; Hermansen, John Erik

    2015-01-01

    The link between climate change and livestock production has made carbon footprint based on life cycle assessment a world-wide indicator to assess and communicate the amount of greenhouse gases emitted per unit of product. Nevertheless, the majority of studies have not included soil carbon...... sequestration in the carbon footprint calculations. Especially in grasslands, soil carbon sequestration might be a potential sink to mitigate greenhouse gas emissions in the livestock sector. However, there is no commonly accepted methodology on how to include soil carbon sequestration in carbon footprint...... calculations. In this study, the carbon footprint of sheep milk was estimated from 12 farms in Northern Spain. Before taken into account contribution from soil carbon sequestration in the calculation, the carbon footprint values varied from 2.0 to 5.2 kg CO2 eq. per kg Fat and Protein Corrected Milk (FPCM...

  13. 46 CFR 56.20-20 - Valve bypasses.

    Science.gov (United States)

    2010-10-01

    ... (incorporated by reference; see 46 CFR 56.01-2). (b) Pipe for bypasses should be at least Schedule 80 seamless... 46 Shipping 2 2010-10-01 2010-10-01 false Valve bypasses. 56.20-20 Section 56.20-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND...

  14. 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

  15. Esterification of glycerol from biodiesel production to glycerol carbonate in non-catalytic supercritical dimethyl carbonate

    OpenAIRE

    Ilham, Zul; Saka, Shiro

    2016-01-01

    Conversion of glycerol from biodiesel production to glycerol carbonate was studied by esterification with dimethyl carbonate in a non-catalytic supercritical condition. It was found that in a non-catalytic supercritical condition, glycerol at higher purity gave higher yield of glycerol carbonate at 98 wt% after reaction at 300 °C/20–40 MPa/15 min. The yield of glycerol carbonate was observed to increase with molar ratio, temperature, pressure and time until a certain equilibrium limit. The ex...

  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. 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.

  18. Abiotic carbonate dissolution traps carbon in a semiarid desert

    Science.gov (United States)

    Fa, Keyu; Liu, Zhen; Zhang, Yuqing; Qin, Shugao; Wu, Bin; Liu, Jiabin

    2016-03-01

    It is generally considered that desert ecosystems release CO2 to the atmosphere, but recent studies in drylands have shown that the soil can absorb CO2 abiotically. However, the mechanisms and exact location of abiotic carbon absorption remain unclear. Here, we used soil sterilization, 13CO2 addition, and detection methods to trace 13C in the soil of the Mu Us Desert, northern China. After 13CO2 addition, a large amount of 13CO2 was absorbed by the sterilised soil, and 13C was found enriched both in the soil gaseous phase and dissolved inorganic carbon (DIC). Further analysis indicated that about 79.45% of the total 13C absorbed by the soil was trapped in DIC, while the amount of 13C in the soil gaseous phase accounted for only 0.22% of the total absorbed 13C. However, about 20.33% of the total absorbed 13C remained undetected. Our results suggest that carbonate dissolution might occur predominately, and the soil liquid phase might trap the majority of abiotically absorbed carbon. It is possible that the trapped carbon in the soil liquid phase leaches into the groundwater; however, further studies are required to support this hypothesis.

  19. Carbon, chromium and molybdenum contents

    International Nuclear Information System (INIS)

    This work describes solidification experiments on white cast iron, with 15 and 20% of chromium, 2.3, 3.0 and 3.6 % of carbon and 0.0, 1.5 and 2.5 % of molybdenum in test de samples with 30 mm diameter. Measurements were performed on the austenite and eutectic formation arrests, the number of the eutectic carbide particles relative to the total and the eutectic volumes, and the volume fraction of the primary austenite

  20. Carbon allocation, sequestration and carbon dioxide mitigation under plantation forests of north western Himalaya, India

    Directory of Open Access Journals (Sweden)

    Bandana Devi

    2013-05-01

    Full Text Available The organic carbon and soils of the world comprise bulk of the terrestrial carbon and serve as a major sink and source of atmospheric carbon. Increasing atmospheric concentrations of green house gases may be mitigated by increasing carbon sequestration in vegetation and soil. The study attempted to estimate biomass production and carbon sequestration potential of different plantation ecosystems in north western Himalaya, India. Biomass, carbon density of biomass, soil, detritus, carbon sequestration and CO2 mitigation potential were studied under different plantation forest ecosystems comprising of eight different tree species: Quercus leucotrichophora, Pinus roxburghii, Acacia catechu, Acacia mollissima, Albizia procera, Alnusnitida, Eucalyptus tereticornis and Ulmus villosa. Above (185.57±48.99tha-1 and below ground (42.47±10.38 tha-1 biomass was maximum in Ulmus villosa. The vegetation carbon density was maxium in Albizia procera(118.37±1.49 tha-1 and minimum (36.50±9.87 tha-1 in Acacia catechu. Soil carbon density was maximum (219.86±10.34 tha-1 in Alnus nitida, and minimum (170.83±20.60 tha-1 in Pinus roxburghii. Detritus was higher in Pinus roxburghii (6.79±2.0 tha-1. Carbon sequestration (7.91±3.4 tha-1 and CO2 mitigation potential (29.09±12.78 tha-1 was maximum in Ulmus villosa. Pearson correlation matrix revealed significant positive relationship of ecosystem carbon with plantation biomass, soil carbon and CO2 mitigation potential. With the emerging threat of climate change, such assessment of forest and soil carbon inventory would allow to devise best land management and policy decisions for sustainable management of fragile hilly ecosystem.

  1. Carbon allocation, sequestration and carbon dioxide mitigation under plantation forests of north western Himalaya, India

    Directory of Open Access Journals (Sweden)

    Bandana Devi

    2013-07-01

    Full Text Available The organic carbon and soils of the world comprise bulk of the terrestrial carbon and serve as amajorsink and source of atmospheric carbon. Increasing atmospheric concentrations of green house gases may be mitigated by increasing carbon sequestration in vegetation and soil. The study attempted to estimate biomass production and carbon sequestration potential of different plantation ecosystems in north western Himalaya, India. Biomass, carbon density of biomass, soil, detritus, carbon sequestration and CO2 mitigation potential were studied underdifferent plantation forest ecosystems comprising of eight different tree species viz. Quercus leucotrichophora, Pinus roxburghii, Acacia catechu, Acacia mollissima, Albizia procera, Alnus nitida, Eucalyptus tereticornis and Ulmus villosa. Above (185.57 ą 48.99 tha-1 and below ground (42.47 ą 10.38 tha-1 biomass was maximum in Ulmus villosa. The vegetation carbon density was maxium in Albizia procera (118.37 ą 1.49 tha-1 and minimum (36.50 ą 9.87 tha-1 in Acacia catechu. Soil carbon density was maximum (219.86ą 10.34 tha-1 in Alnus nitida, and minimum (170.83ą 20.60 tha-1in Pinus roxburghii. Detritus was higher in Pinus roxburghii (6.79 ą 2.0 tha-1. Carbon sequestration (7.91ą 3.4 tha-1 and CO2 mitigation potential (29.09 ą 12.78 tha-1 was maximum in Ulmus villosa. Pearson correlation matrix revealed significant positive relationship of ecosystem carbon with plantation biomass, soil carbon and CO2 mitigation potential. With the emerging threat of climate change, such assessment of forest and soil carbon inventory would allow to devise best land management and policy decisions forsustainable management of fragile hilly ecosystem. 

  2. Effect of carbon nanofibers on the infiltration and thermal conductivity of carbon/carbon composites

    International Nuclear Information System (INIS)

    Highlights: → The CNFs improve the infiltration rate and thermal properties of carbon/carbon composites. → The densification rate increases with the CNF content increasing at the beginning of infiltration. → The values of the thermal conductivity of the composite obtain their maximum values at 5 wt.%. -- Abstract: Preforms containing 0, 5, 10, 15 and 20 wt.% carbon nanofibers (CNFs) were fabricated by spreading layers of carbon cloth, and infiltrated using the electrified preform heating chemical vapor infiltration method (ECVI) under atmospheric pressure. Initial thermal gradients were determined. Resistivity and density evolutions with infiltration time have been recorded. Scanning electron microscopy, polarized light micrograph and X-ray diffraction technique were used to analyze the experiment results. The results showed that the infiltration rate increased with the rising of CNF content, and after 120 h of infiltration, the density was the highest when the CNF content was 5 wt.%, but the composite could not be densified efficiently as the CNF content ranged from 10 wt.% to 20 wt.%. CNF-reinforced C/C composites have enhanced thermal conductivity, the values at 5 wt.% were increased by nearly 5.5-24.1% in the X-Y direction and 153.8-251.3% in the Z direction compared to those with no CNFs. When the additive content was increased to 20 wt.%, due to the holes and cavities in the CNF web and between carbon cloth and matrix, the thermal conductivities in the X-Y and Z directions decreased from their maximum values at 5 wt.%.

  3. 10 CFR 20.2005 - Disposal of specific wastes.

    Science.gov (United States)

    2010-01-01

    ... Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION Waste Disposal § 20.2005... not radioactive: (1) 0.05 microcurie (1.85 kBq), or less, of hydrogen-3 or carbon-14 per gram of medium used for liquid scintillation counting; and (2) 0.05 microcurie (1.85 kBq), or less, of...

  4. 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

  5. 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 ...

  6. 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...

  7. 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 ...

  8. Carbon allowance allocation in the transportation industry

    International Nuclear Information System (INIS)

    This study proposes models for projecting reductions in CO2 emissions of 10%, 20%, 30%, and 40% compared to business as usual (BAU), using a carbon allowance allocation policy and both unimodal and intermodal modes of transportation. The results show that for 10% to 80% decreases in free carbon allowance, the intermodal ratio increased from 1.01% to 53.44%, which led to decreases in carbon emissions and demand ranging from 10.41% to 48.19% and 8.45% to 7.57%, respectively. When free carbon allowances are decreased, the demand for intermodal systems increases accordingly. These results suggest that a carbon allowance allocation policy could mitigate transportation carbon emissions with a relatively small negative impact on economic activity. - Highlights: • This study proposes models for CO2 reduction by using carbon allowance policy. • This study found decreases in carbon allowance allocation, the intermodal ratio increased. • Truck-only transport will be replaced by intermodal transport. • The carbon allowance allocation policy cause small negative impact on economic activity

  9. Carbonate and carbon fluctuations in the Eastern Arabian Sea over 140 ka: Implications on productivity changes?

    Digital Repository Service at National Institute of Oceanography (India)

    Guptha, M.V.S.; Naidu, P.D.; Haake, B.G.; Schiebel, R.

    -driven upwelling (Murray and Prell, 1992). A reliable organic carbon-based index of productivity must 0.0 -1.0 -2.0 -3.0 δ 18 O( ‰ ) 0 20 40 60 Age 20 Fig.4. Oxygenisotopestratigraphy,downcorevariationofcalcium coreSK129-CR05 (afterPattanetal.2003).LSR... andsummerinsolationmaximaintheprecessional frequencyband,itissuggestedthattheTOCsignal reflects either preservation changes due to en- hancedsedimentationratesortotheproductionof organic carbon and is not directly linked to monsoonal upwelling (Murray and Prell, 1992). In contrast, variation...

  10. Total organic carbon analyzer

    Science.gov (United States)

    Godec, Richard G.; Kosenka, Paul P.; Smith, Brian D.; Hutte, Richard S.; Webb, Johanna V.; Sauer, Richard L.

    1991-01-01

    The development and testing of a breadboard version of a highly sensitive total-organic-carbon (TOC) analyzer are reported. Attention is given to the system components including the CO2 sensor, oxidation reactor, acidification module, and the sample-inlet system. Research is reported for an experimental reagentless oxidation reactor, and good results are reported for linearity, sensitivity, and selectivity in the CO2 sensor. The TOC analyzer is developed with gravity-independent components and is designed for minimal additions of chemical reagents. The reagentless oxidation reactor is based on electrolysis and UV photolysis and is shown to be potentially useful. The stability of the breadboard instrument is shown to be good on a day-to-day basis, and the analyzer is capable of 5 sample analyses per day for a period of about 80 days. The instrument can provide accurate TOC and TIC measurements over a concentration range of 20 ppb to 50 ppm C.

  11. 20 Years of RECONS

    Science.gov (United States)

    Henry, Todd J.; RECONS

    2014-01-01

    RECONS (REsearch Consortium On Nearby Stars, www.recons.org) turns 20 in 2014, so we take this opportunity to review some of the highlights of the RECONS effort over the past two decades. Through comprehensive searches for new nearby stars, as well as characterization of the stars and exploration of their environments, the RECONS team has made significant contributions to our understanding of the solar neighborhood, and of our own place in the Universe. Here we highlight results detailed in more than 30 papers in The Solar Neighborhood series published in The Astronomical Journal, including: (1) a census indicating that at least 75% of all stars are red dwarfs, which have more real estate available for habitable planets than any other type of star, (2) more than 300 new stellar systems with accurate trigonometric parallaxes placing them within 25 pc, including 12 of the nearest 100 systems, (3) thousands of additional nearby star candidates identified through traditional proper motion searches and novel photometric searches for stars exhibiting minimal proper motions, (4) increases of more than 20% in the nearest white dwarf and cool subdwarf populations, (5) discovery of the nearest star, AP Col, younger than 100 million years, (6) knowledge that more than half of stellar systems contain only one star, dominated by the red dwarf multiplicity rate of only about 30%, (7) definition of the smallest main sequence star, with a radius only 9% that of the Sun (smaller than Jupiter) and a temperature of 2100K, and (8) a revelation that the smallest stars are rarely orbited by giant planets, including the elimination of planets down to half a Jupiter mass orbiting Proxima Centauri. As RECONS enters its third decade, we continue our reconnaissance of the solar neighborhood via a comprehensive survey to understand the nature of star formation by determining accurate luminosity and mass functions for the nearest stars. In addition, we are taking an inventory of nearby planets

  12. Carbon dioxide production in animal houses

    DEFF Research Database (Denmark)

    Pedersen, Søren; Blanes-Vidal, Victoria; Joergensen, H.;

    2008-01-01

    This article deals with carbon dioxide production from farm animals; more specifically, it addresses the possibilities of using the measured carbon dioxide concentration in animal houses as basis for estimation of ventilation flow (as the ventilation flow is a key parameter of aerial emissions from...... animal houses). The investigations include measurements in respiration chambers and in animal houses, mainly for growing pigs and broilers. Over the last decade a fixed carbon dioxide production of 185 litres per hour per heat production unit, hpu (i.e. 1000 W of the total animal heat production at 20o......C) has often been used. The article shows that the carbon dioxide production per hpu increases with increasing respiration quotient. As the respiration quotient increases with body mass for growing animals, the carbon dioxide production per heat production unit also increases with increased body mass...

  13. Carbon isotope effects associated with aceticlastic methanogenesis

    Science.gov (United States)

    Gelwicks, J. T.; Risatti, J. B.; Hayes, J. M.

    1994-01-01

    The carbon isotope effects associated with synthesis of methane from acetate have been determined for Methanosarcina barkeri 227 and for methanogenic archaea in sediments of Wintergreen Lake, Michigan. At 37 degrees C, the 13C isotope effect for the reaction acetate (methyl carbon) --> methane, as measured in replicate experiments with M. barkeri, was - 21.3% +/- 0.3%. The isotope effect at the carboxyl portion of acetate was essentially equal, indicating participation of both positions in the rate-determining step, as expected for reactions catalyzed by carbon monoxide dehydrogenase. A similar isotope effect, - 19.2% +/- 0.3% was found for this reaction in the natural community (temperature = 20 degrees C). Given these observations, it has been possible to model the flow of carbon to methane within lake sediment communities and to account for carbon isotope compositions of evolving methane. Extension of the model allows interpretation of seasonal fluctuations in 13C contents of methane in other systems.

  14. 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.

  15. 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...

  16. Carbon nanostructures produced through ion irradiation

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Several nanostructures we produced by ion irradiation have been reviewed in this paper. By using ions to irradiate two ultrahigh molecular weight polyethylene targets respectively, it was found that small fullerenes C20 and C26 were grown, adding two members to the fullerene family. Meanwhile, crystalline diamonds also have been produced by Ar+ ions irradiation of graphite. In the experiment of double ions Ni+ and Ar+ irradiation, nanoscale argon bubbles formed. On the other side, when multi-wall carbon nanotubes were irradiated by C+, many MWCNTs evolved to amorphous carbon nanowires and amorphous carbon nanotubes. And there are possible welding in the crossed nanotubes.

  17. EDF Group reduces its carbon footprint

    International Nuclear Information System (INIS)

    Although EDF's carbon footprint in France is already very low (40 g of CO2/kWh) compared to coal-fired units (about 20 times more) or even to gas-fired combined cycles (about 10 times more), its stakes in fossil-fired power plants in Europe and overseas contribute to a total amount of 64 million tonnes of CO2 emissions per year. Therefore, reduction of carbon emissions represents a real challenge; besides demand side management, renewable developments, efficiency improvement, fuel switching from coal to gas and contribution to the nuclear revival. CCS (Carbon Capture and Storage) technologies development is also part of the picture. (orig.)

  18. 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

  19. Carbon Stars in the Galactic Halo

    Science.gov (United States)

    Totten, E. J.; Irwin, M. J.

    1996-04-01

    A byproduct of the APM high redshift quasar survey (Irwin et al. 1991) was the discovery of ~ 20 distant (20-100kpc) cool AGB carbon stars (all N-type) at high Galactic latitude. In August we used the INT+IDS to survey the rest of the high latitude SGC sky visible from La Palma and found 10 more similar carbon stars. Before this work there were only a handful of published faint high latitude cool carbon stars known (eg. Margon et al., 1984, Mould et al., 1985) and there has been speculation as to their origin (eg. Sanduleak, 1980, van den Bergh & Lafontaine, 1984). Intermediate age carbon stars (3 -- 7 Gyrs) seem unlikely to have formed in the halo in isolation from other star forming regions so how did they get there ? One possiblity that we are investigating, is that they arise from either the disruption of tidally captured dSph galaxies or are a manifestion of the long sought after optical component of the Magellanic Stream. Lack of proper motion rules out the possibility of them being dwarf carbon stars (eg. Warren et al., 1992); indeed no N-type carbon stars have been found to be dwarf carbon stars. Our optical spectroscopy confirms their carbon star type (they are indistinguishable from cool AGB carbon stars in nearby dwarf galaxies) and hence probable large distances. We are extending our survey to the NGC region, obtaining radial velocities and good S:N fluxed spectra for all the carbon stars. This will enable us to investigate their kinematics, true spatial distribution and hence their origin. Even, in the event that these objects are somehow an integral part of the Galactic halo, then their velocities and large distances will enable direct studies of the velocity ellipsoid and rotation of the outer halo (eg. Green et al., 1994).

  20. New Volleyballenes: Y20C60, La20C60, and Lu20C60

    OpenAIRE

    Wang, Jing; Liu, Ying(College of Nuclear Science and Technology, Beijing Normal University, 100875, Beijing, China)

    2015-01-01

    New stable Volleyballenes Y20C60, La20C60, and Lu20C60 molecular clusters have been proposed using first-principles density functional theory studies. In conjunction with recent findings for the scandium system, these findings establish Volleyballene M20C60 molecules as a stable general class of fullerene family. All M20C60 (M=Y, La, and Lu) molecules have Th point group symmetries and relatively large HOMO-LUMO gaps.

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

    International Nuclear Information System (INIS)

    Highlights: • Bamboo fiber and waste paper were pyrolyzed to generate bamboo carbon and waste paper carbon as anode fuels of IT-DCFC. • Superior cell performance was achieved with the waste paper carbon. • The results suggested the high performance was due to the highest thermal reactivity and the catalytic inherent impurities. • Calcite and kaolinite as inherent impurities favored the thermal decomposition and the electrooxidation of carbon. - Abstract: Three kinds of carbon sources obtained from carbon black, bamboo fiber and waste paper were investigated as anode fuels in an intermediate temperature direct carbon fuel cell. The carbon sources were characterized with X-ray photoelectron spectroscopy, thermal gravimetric analysis, etc. The results indicated that the waste paper carbon was more abundant in calcite and kaolinite, and showed higher thermal reactivity in the intermediate temperature range compared with the other two carbon sources. The cell performance was tested at 650 °C in a hybrid single cell, using Sm0.20Ce0.80O2−x as the electrolyte. As a result, the cell fed with waste paper carbon showed the highest performance among the three carbon sources, with a peak power density of 225 mW cm−2. The results indicated that its inherent impurities, such as calcite and kaolinite, might favor the thermal gasification of renewable carbon sources, which resulted in the enhanced performance of the intermediate temperature direct carbon fuel cell

  2. Composite carbon foam electrode

    Science.gov (United States)

    Mayer, S.T.; Pekala, R.W.; Kaschmitter, J.L.

    1997-05-06

    Carbon aerogels used as a binder for granulated materials, including other forms of carbon and metal additives, are cast onto carbon or metal fiber substrates to form composite carbon thin film sheets. The thin film sheets are utilized in electrochemical energy storage applications, such as electrochemical double layer capacitors (aerocapacitors), lithium based battery insertion electrodes, fuel cell electrodes, and electrocapacitive deionization electrodes. The composite carbon foam may be formed by prior known processes, but with the solid particles being added during the liquid phase of the process, i.e. prior to gelation. The other forms of carbon may include carbon microspheres, carbon powder, carbon aerogel powder or particles, graphite carbons. Metal and/or carbon fibers may be added for increased conductivity. The choice of materials and fibers will depend on the electrolyte used and the relative trade off of system resistivity and power to system energy. 1 fig.

  3. Maximizing carbon uptake and performance gain in slag-containing concretes through early carbonation

    Science.gov (United States)

    Monkman, Sean

    Carbon dioxide (CO2) emissions have been identified as a major contributor to climate change. Current CO2 mitigation efforts focus on the removal, recovery and disposal of CO2 at point sources. Finding beneficial uses of as-captured or recovered CO2 is a critical challenge in greenhouse gas mitigation. This thesis investigates the possibility of the beneficial use of carbon dioxide in precast concrete production and the performance, both short-term and long-term, of the concretes so produced. The calcium compounds in cementitious materials react readily with carbon dioxide to convert CO2 to thermodynamically stable carbonates. The reaction accelerates strength development and makes the technology appropriate for early age curing. Paste, mortar and concrete samples were examined to quantify such aspects as the carbon dioxide uptake, strength development, and durability of carbonated concrete. It was found that the uptake by the cementitious binders was significant. Compared to their theoretical capacity, cement could reach a carbonation degree of over 25% when treated as pastes and about 20% when used as a part of concrete. The study compared carbonation-cured and hydrated Portland cement concrete and slag cement concretes in terms of their early strength, late strength, weathering carbonation shrinkage, freeze/thaw durability, water absorption, and pH. The carbonated concrete was generally comparable, or superior, to the hydrated concrete except for the case of a 50% GGBF slag blend which had a slower strength development due to reduced secondary cementitious reaction. A second method of binding carbon into concrete was considered by carbonating ladle slag fines and using them as a fine aggregate. The 28-day strength of concrete, either hydrated or carbonation-cured, made with the manufactured slag aggregate was comparable to that of a hydrated concrete made with conventional fine aggregate. Carbon dioxide uptake by concrete was nearly doubled if carbonation

  4. Sequestration of Soil Carbon as Secondary Carbonates (Invited)

    Science.gov (United States)

    Lal, R.

    2013-12-01

    Rattan Lal Carbon Management and Sequestration Center The Ohio State University Columbus, OH 43210 USA Abstract World soils, the major carbon (C) reservoir among the terrestrial pools, contain soil organic C (SOC) and soil inorganic C (SIC). The SIC pool is predominant in soils of arid and semi-arid regions. These regions cover a land area of about 4.9x109 ha. The SIC pool in soils containing calcic and petrocalcic horizons is estimated at about 695-748 Pg (Pg = 1015 g = 1 gigaton) to 1-m depth. There are two types of carbonates. Lithogenic or primary carbonates are formed from weathering of carbonaceous rocks. Pedogenic or secondary carbonates are formed by dissolution of CO2 in the soil air to form carbonic acid and precipitation as carbonates of Ca+2 or Mg+2. It is the availability of Ca+2 or Mg+2 from outside the ecosystem that is essential to sequester atmospheric CO2. Common among outside sources of Ca+2 or Mg+2 are irrigation water, aerial deposition, sea breeze, fertilizers, manure and other amendments. The decomposition of SOC and root respiration may increase the partial pressure of CO2 in the soil air and lead to the formation of HCO_3^- upon dissolution in H20. Precipitation of secondary carbonates may result from decreased partial pressure of CO2 in the sub-soil, increased concentration of Ca+2, Mg+2 and HCO_3^- in soil solution, and decreased soil moisture content by evapotranspiration. Transport of bicarbonates in irrigated soils and subsequent precipitation above the ground water (calcrete), activity of termites and other soil fauna, and management of urban soils lead to formation of secondary carbonates. On a geologic time scale, weathering of silicate minerals and transport of the by-products into the ocean is a geological process of sequestration of atmospheric CO2. Factors affecting formation of secondary carbonates include land use, and soil and crop management including application of biosolids, irrigation and the quality of irrigation water

  5. Model-based estimation of the global carbon budget and its uncertainty from carbon dioxide and carbon isotope records

    International Nuclear Information System (INIS)

    A global carbon cycle model is used to reconstruct the carbon budget, balancing emissions from fossil fuel and land use with carbon uptake by the oceans, and the terrestrial biosphere. We apply Bayesian statistics to estimate uncertainty of carbon uptake by the oceans and the terrestrial biosphere based on carbon dioxide and carbon isotope records, and prior information on model parameter probability distributions. This results in a quantitative reconstruction of past carbon budget and its uncertainty derived from an explicit choice of model, data-based constraints, and prior distribution of parameters. Our estimated ocean sink for the 1980s is 17±7 Gt C (90% confidence interval) and is comparable to the estimate of 20±8 Gt C given in the recent Intergovernmental Panel on Climate Change assessment [Schimel et al., 1996]. Constraint choice is tested to determine which records have the most influence over estimates of the past carbon budget; records individually (e.g., bomb-radiocarbon inventory) have little effect since there are other records which form similar constraints. (c) 1999 American Geophysical Union

  6. Improvement in char formability of phenolic resin for development of Carbon/Carbon composites

    International Nuclear Information System (INIS)

    In the processing of carbon/carbon composites using polymer resin as the matrix precursor, it is inevitable that a porous structure was formed after carbonization. As a result, densification by liquid phase impregnation followed by recarbonization is required to obtain a densified composite. Consequently, the char formability of resin is an important factor in reducing the number of densification cycles and hence the processing cost. In this study, a novel approach is adopted to improve the densification of carbon/carbon composites by using a new phenolic resin modified by pitch. For this purpose, soluble part of pitch was extracted and dispersed in resol type phenolic resin. The polymerization reaction was performed in presence of para-formaldehyde and a resol-pitch compound was obtained. The second compound was prepared by mixing novolac-furfural in 55:45 weight ratio containing 9% by weight hexamethylene tetramine. This compound was added to resol-pitch compound in 10,20,50 and 80 w %. The microstructure of carbonized resin was investigated by X-ray diffraction and char yield, and the linear and volumetric shrinkage were obtained. Results show that in 80:20 ratio of resol-pitch to novolac-furfural , the char yield would be maximized by 71% and volumetric shrinkage would be minimized at 16.4%. At the same time, XRD results indicate that the resin has a strong ability to graphitize carbon/carbon composites matrix as a necessary step for its processing

  7. Deep Soil: Quantifying and Modeling Subsurface Carbon

    Science.gov (United States)

    James, J. N.; Devine, W.; Harrison, R. B.

    2014-12-01

    Some soil carbon datasets that are spatially rich, such as the USDA Forest Service Inventory and Analysis National Program dataset, sample soil to only 20 cm (8 inches), despite evidence that substantial stores of soil C can be found deeper in the soil profile. The maximum extent of tree rooting is typically many meters deep and provides: direct exchange with the soil solution; redistribution of water from deep horizons toward the surface during times of drought; resources for active microbial communities in deep soil around root channels; and direct carbon inputs through exudates and root turnover. This study examined soil carbon to a depth of 2.5 meters across 22 soils in Pacific Northwest Douglas-fir forests. Excavations at 20 additional sites took place in summer 2014, greatly expanding the spatial coverage and extent of the data set. Forest floor and mineral soil bulk density samples were collected at depths of 0.1, 0.5, 1.0, 1.5, 2.0 and 2.5 meters. Pool estimates from systematic sampling depths shallower than 1.5 m yielded significantly smaller estimates than the total soil stock to 2.5 meters (PAndisols with non-crystalline minerals, which can adsorb large quantities of carbon on mineral surfaces and preserve it from decomposition. An accurate spatial dataset of soil depth to bedrock would be extremely useful to constrain models of the vertical distribution of soil carbon. Efforts to represent carbon in spatial models would benefit from considering the vertical distribution of carbon in soil. Sampling deep soil will avoid biased estimates of soil carbon and create a more complete picture of soil pools and changes over time.

  8. Web 2.0 aplikace

    OpenAIRE

    Lednický, Miroslav

    2008-01-01

    Following pages will be about abounded term "Web 2.0". I will try to explain the core characteristics of "Web 2.0" applications. This explanation will be followed by some existing examples of these applications. Main target is to explain the term "Web 2.0".

  9. 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 and...

  10. Radiation polymerization of vinylene carbonate

    International Nuclear Information System (INIS)

    The radiation-induced polymerization of vinylene carbonate of 99,97% purity has been investigated. The relationship between conversion and irradiation time is strictly linear, even at the lowest conversions, thus proving that the normal induction period observed for the polymerization of lower-purity vinylene carbonate indeed results from the presence of an inhibitor. Although the identity of the inhibitor has not been established, it has been shown that it is not dichlorovinylene carbonate. An activation energy of 15,1 kJ/mole was calculated for the homopolymerization process. The radiation-induced copolymerization of vinylene carbonate (M1) with isobutyl vinyl ether (M2) has been investigated over the temperature range of 40-80 degrees Celcius. The monomer reactivity ratios r1 and r2 were determined to be 0,118 and 0,148 respectively, and an activation energy of 31,8kJ/mole was calculated for the copolymerization process. The radiation-induced telomerization of vinylene carbonate with carbon tetrachloride has been investigated over a telogen to monomer concentration ratio range of 4 to 20. The rate of formation of the n=1 adduct was found to be independent of monomer concentration, directly proportional to the telogen concentration, and exhibiting a 0,38 order power dependence on the radiation intensity, in general agreement with the derived rate equations. The rate of formation of the n=2 telomer was found to be independent of both monomer and telogen concentrations and radiation intensity, which is not in agreement with the derived rate equations. The first and second chain-transfer coefficients C1 and C2 were determined to be 0,116 and 0,34 respectively, and the activation energies for the formation of the n=1 adduct and n=2 telomer were calculated to be 17,6 and 64,9 kJ/mole respectively

  11. 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

  12. Interaction cross-sections and matter radii of A = 20 isobars

    International Nuclear Information System (INIS)

    High-energy interaction cross-sections of A=20 nuclei (20N, 20O, 20F, 20Ne, 20Na, 20Mg) on carbon were measured with accuracies of ∼1%. The nuclear matter rms radii derived from the measured cross-sections show an irregular dependence on isospin projection. The largest difference in radii, which amounts to approximately 0.2 fm, has been obtained for the mirror nuclei 20O and 20Mg. The influenc of nuclear deformation and binding energy on the radii is discussed. By evaluating the difference in rms radii of neutron and proton distributions, evidence has been found for the existence of a proton skin for 20Mg and of a neutron skin for 20N. (orig.)

  13. 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.

  14. Amorphous carbon and its surfaces

    International Nuclear Information System (INIS)

    Graphical abstract: Some examples of 2.0 g/cm3 surfaces. The cell contained 64 atoms. The top figure shows some tube-like formation, the central figure is an example of a wave-like surface, and the bottom figure is an example of the bending over of the carbons at the surface to form a surface sheet when the sheets in the bulk are not parallel to the surface. - Abstract: We have investigated bulk amorphous carbon at three densities (3.2, 2.6, and 2.0 g/cm3) using density functional theory (DFT). The variation in the structure with density is discussed. The bulk structures are used to create surface structures. If the surfaces are relaxed at 700 K, the surface structures, as a function of density, are more similar than the analogous bulk structures. The relaxed surfaces appear to be graphene sheets with defects, sizable distortions, and have covalently bonded carbon chains holding the sheets together.

  15. A new direction in search of "missing" carbon sinks

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ A CAS scientist succeeds in developing a new direction for exploring the inorganic carbon cycle of the earth. His creative work was recently reported by the 20th issue of Chinese Science Bulletin in 2007.

  16. Wood - a carbon depot

    OpenAIRE

    Lipušček, Igor; Tišler, Vesna

    2003-01-01

    The article examines the global movement of carbon dioxide, the most important greenhouse gas due to its large quantities. We studied the carbon cycle with possibilities of its extension, and analysed the mechanisms that remove carbon dioxide from the atmosphere and bind it into solid substances for a longer period of time. The focus was on carbon dioxide sink into biomass and carbon deposit in wood. On the basis of wood component data and chemical analysis of the components, we calculated th...

  17. Reinforcing Effects of Carbon Black on Asphalt Binder for Pavement

    OpenAIRE

    Yamaguchi, Katsuyuki; Sasaki, Iwao; Nishizaki, Itaru; Meiarashi, Seishi; Moriyoshi, Akihiro

    2005-01-01

    Carbon black, used as a reinforcing filler for rubber materials, was evaluated for asphalt binders in pavements. Carbon black added to straight asphalt within 20 wt% caused an increase in the elastic modulus and a decrease in the viscosity of the asphalt, especially at temperatures higher than room temperature. Addition of carbon black raised the maximum service temperature of asphalt in the category of the binder performance grade according to the SHRP (Strategic Highway Research Program) sp...

  18. Numerical investigations of using carbon foam/PCM/Nano carbon tubes composites in thermal management of electronic equipment

    International Nuclear Information System (INIS)

    Highlights: • A numerical model to predict thermal management of electronic modules using different composite materials. • Effect of insertion of RT65 as PCM and MWCNTs as thermal enhancer in the carbon foam micro cells is evaluated. • Delay and decrease of modules temperature increase with the inclusion of PCM and MWCNTs in the module. • Model prediction of previous experimental data was obtained. - Abstract: A numerical investigation of predicting thermal characteristics of electronic equipment using carbon foam matrix saturated with phase change material (PCM) and Nano carbon tubes as thermal management modules is presented. To study the effect of insertion of RT65 and Nano carbon tubes in carbon foam matrices of different porosities, three different modules; namely Pure CF-20, CF20 + RT65, and CF-20 + RT65/Nano carbon modules are numerically tested at different values of carbon foam porosities. Mathematical model is obtained using volume averaging technique based on single-domain energy equation and a control volume based numerical scheme. Interfacial effects influencing heat transfer process at enclosure wall, module surface and different interfacial surfaces within the composite have been addressed. Governing equations have been solved using a CFD code (Thétis, (http://thetis.enscbp.fr)). Mathematical model is validated by comparing its prediction with previous experimental measurements for pure CF-20 foam and CF-20 + RT65 composite modules. The model is used to predict thermal characteristics of CF-20 + RT65/Nano carbon tubes composite as a thermal management modules. Results reveal that insertion of RT65/MWCNTs in CF-20 leads to a 11.5% reduction in the module surface temperature for carbon foam porosities less than 75%. The reduction decrease to 7.8% for a porosity of 88%. Numerical results of transient and steady state temperature histories at different depths within the module are compared with previous experimental data and fair agreement is

  19. Speculations about RM 20/20 red mercury

    International Nuclear Information System (INIS)

    In the past few years, cases of illegal trading in so-called Red Mercury (RM 20/20) from the former Soviet Union have been reported again and again. The speculations about this mysterious material are based on the fact that it could be used especially in making miniature atom bombs or straightforward fusion bombs, which would pave the way for global nuclear terrorism. The article contains the scientific views on RM 20/20 and its basic physics and chemistry. The conclusion is that the alleged basic principles of this superexplosive do not exist. The whole thing, in all probability, seems to be a hoax. (orig.)

  20. Production of activated carbon from Atili seed shells

    Directory of Open Access Journals (Sweden)

    Nehemiah Samuel MAINA

    2014-11-01

    Full Text Available Activated carbon was produced from atili (black date seed shells by chemical activation with phosphoric acid as an activating agent. Carbonization was done at temperatures of 350°C, 450°C, 550°C, 650°C and at corresponding resident times of 20, 30, 40, 50 and 60 minutes respectively in a muffle furnace. The study involved the determination of yield, carbon content, burn-off, moisture content, and ash content as well as the temperature and suitable resident time for carbonization. The result showed that, increasing the carbonization temperature from 350°C to 650°C as well as increasing the corresponding resident time from 20 to 60 minutes led to a decrease in carbonization yield as well as an increase in burn off. An increase in carbonization time led to a decrease in ash content while an increase in carbonization temperature led to a decrease in the moisture content. The yield, burn-off and ash content obtained at a carbonization temperature of 650°C and at a corresponding time of 60 minutes were found to be 68.29%, 31.71% and 0.75% respectively while the highest carbon content (99.16 and lowest moisture content (0.09 was obtained at this same temperature and corresponding time. The activated carbon produced gave a yield of 99.37%, ash content (2.01%, moisture content (4.20%, carbon content (93.79%, burn off (0.63% and pH of 6.752. These properties therefore indicate the suitability of the activated carbon produced.

  1. Influence of metal-containing carbon fibers on the properties of carbon-filled plastics based on aromatic polyamide

    Science.gov (United States)

    Burya, A. I.; Safonova, A. M.; Rula, I. V.

    2012-07-01

    The influence of metal-containing carbon fibers on the thermal properties of carbon-filled phenylone-based plastics has been investigated. It has been shown that carbometallic fibers containing in their composition 20- 30 mass % of a finely dispersed metal (Co, Cu) are promising fillers of phenylone C-2 for making carbonfilled plastics working in frictional units of various machines and mechanisms.

  2. Deforestation in Amazonia impacts riverine carbon dynamics

    Science.gov (United States)

    Langerwisch, F.; Walz, A.; Rammig, A.; Tietjen, B.; Thonicke, K.; Cramer, W.

    2015-10-01

    Fluxes of organic and inorganic carbon within the Amazon basin are considerably controlled by annual flooding, which triggers the export of terrigenous organic material to the river and ultimately to the Atlantic Ocean. The amount of carbon imported to the river and the further conversion, transport and export of it, depend on terrestrial productivity and discharge, as well as temperature and atmospheric CO2. Both terrestrial productivity and discharge are influenced by climate and land use change. To assess the impact of these changes on the riverine carbon dynamics, the coupled model system of LPJmL and RivCM (Langerwisch et al., 2015) has been used. Vegetation dynamics (in LPJmL) as well as export and conversion of terrigenous carbon to and within the river (RivCM) are included. The model system has been applied for the years 1901 to 2099 under two deforestation scenarios and with climate forcing of three SRES emission scenarios, each for five climate models. The results suggest that, following deforestation, riverine particulate and dissolved organic carbon will strongly decrease by up to 90 % until the end of the current century. In parallel, discharge increases, leading to roughly unchanged net carbon transport during the first decades of the century, as long as a sufficient area is still forested. During the following decades the amount of transported carbon will decrease drastically. In contrast to the riverine organic carbon, the amount of riverine inorganic carbon is only determined by climate change forcing, namely increased temperature and atmospheric CO2 concentration. Mainly due to the higher atmospheric CO2 it leads to an increase in riverine inorganic carbon by up to 20 % (SRES A2). The changes in riverine carbon fluxes have direct effects on the export of carbon, either to the atmosphere via outgassing, or to the Atlantic Ocean via discharge. Basin-wide the outgassed carbon will increase slightly, but can be regionally reduced by up to 60 % due to

  3. Graphene: carbon in two dimensions

    Directory of Open Access Journals (Sweden)

    Mikhail I. Katsnelson

    2007-01-01

    Full Text Available Carbon is one of the most intriguing elements in the Periodic Table. It forms many allotropes, some known from ancient times (diamond and graphite and some discovered 10-20 years ago (fullerenes and nanotubes. Interestingly, the two-dimensional form (graphene was only obtained very recently, immediately attracting a great deal of attention. Electrons in graphene, obeying a linear dispersion relation, behave like massless relativistic particles. This results in the observation of a number of very peculiar electronic properties – from an anomalous quantum Hall effect to the absence of localization – in this, the first two-dimensional material. It also provides a bridge between condensed matter physics and quantum electrodynamics, and opens new perspectives for carbon-based electronics.

  4. 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

  5. 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.

  6. Black Carbon, The Pyrogenic Clay Mineral?

    Science.gov (United States)

    Most soils contain significant amounts of black carbon, much of which is present as discrete particles admixed with the coarse clay fraction (0.2–2.0 µm e.s.d.) and can be physically separated from the more abundant diffuse biogenic humic materials. Recent evidence has shown that naturally occurring...

  7. High density carbon materials obtained at relatively low temperature by spark plasma sintering of carbon nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Borrell, Amparo; Torrecillas, Ramon [Nanomaterials and Nanotechnology Research Center (CINN), Principado de Asturias - Consejo Superior de Investigaciones Cientificas (CSIC), Univ. de Oviedo, Parque Tecnologico de Asturias, Llanera (Spain); Fernandez, Adolfo [Fundacion ITMA, Parque Tecnologico de Asturias, Llanera (Spain); Merino, Cesar [Grupo Antolin Ingenieria, Burgos (Spain)

    2010-01-15

    Graphitic materials obtained at low temperatures are interesting for a wide range of industrial applications including bipolar plates. In this work, graphite based nanocomposites have been obtained starting from carbon nanofibers and a mixture of carbon nanofibers with 20 vol.% of alumina nanopowders. High density carbon components were obtained by using Spark Plasma Sintering at temperatures as low as 1500-1800 C for this kind of materials. The effect of spark plasma sintering parameters on the final density, and the mechanical and electrical properties of resulting nanocomposites have been investigated. Pure carbon nanofibers with around 90% of theoretical density and fracture strength of 60 MPa have been obtained at temperatures as low as 1500 C applying a pressure of 80 MPa during sintering. It has been proved that attrition milling is a suitable method for preparing homogeneous mixtures of carbon nanofibers and alumina powders. (orig.)

  8. Simple Cubic Carbon Phase C21-sc: A Promising Superhard Carbon Conductor

    OpenAIRE

    He, Chaoyu; MENG, LIJUN; Tang, Chao; Zhong, Jianxin

    2014-01-01

    Traditionally, all superhard carbon phases including diamond are electric insulators and all conductive carbon phases including graphite are mechanically soft. Based on first-principles calculation results, we report a superhard but conductive carbon phase C21-sc which can be obtained through increasing the sp3 bonds in the previously proposed soft and conductive phase C20-sc (Phys. Rev. B 74, 172101 2006). We also show that further increase of sp3 bonds in C21-sc results in a superhard and i...

  9. 20 CFR 632.20 - Submission of grant application.

    Science.gov (United States)

    2010-04-01

    ... NATIVE AMERICAN EMPLOYMENT AND TRAINING PROGRAMS Program Planning, Application and Modification Procedures § 632.20 Submission of grant application. (a) Beginning with 1985 or the first designation period... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Submission of grant application....

  10. Carbon storage and recycling in short-rotation energy crops

    International Nuclear Information System (INIS)

    Short-rotation energy crops can play a significant role in storing carbon compared to the agricultural land uses they would displace. However, the benefits from these plantations in avoiding further use of fossil fuels and in taking pressure off native forests for energy uses provides longer term carbon benefits than the plantation carbon sequestration itself. The fast growth and harvest frequency of plantations tends to limit the amount of above- and below-ground carbon storage in them. The primary components of plantation carbon sequestering compared to sustained agricultural practices involve above ground wood, possible increased soil carbon, litter layer formation, and increased root biomass. On the average, short-rotation plantations in total may increase carbon inventories by about 10 to 40 tonnes per hectare over about a 20 to 50 year period when displacing cropland. This is about doubling in storage over cropland and about one-half the storage in human-impacted forests. The sequestration benefit of wood energy crops over cropland would be negated in about 75 to 100 years by the use of fossil fuels to tend the plantations and handle biomass. Plantation interactions with other land uses and total landscape carbon inventory is important in assessing the relative role plantations play in terestrial and atmospheric carbon dynamics. It is speculated that plantations, when viewed in this context, could generate a global levelling of net carbon emissions for approximately 10 to 20 years. 16 refs., 7 figs

  11. Carbon storage and recycling in short-rotation energy crops

    International Nuclear Information System (INIS)

    Short-rotation energy crops can play a significant role in storing carbon compared to the agricultural land uses they would displace. However, the benefits from these plantations in avoiding further use of fossil fuel and in taking pressure off of native forests for energy uses provides longer term carbon benetfits than the plantation carbon sequestration itself. The fast growth and harvest frequency of plantations tends to limit the amount of above and below-ground carbon storage in them. The primary components of plantation carbon sequestering compared to sustained agricultural practices involve above-ground wood, possible increased soil carbon, litter layer formation, and increased root biomass. On the average, short-rotation plantations in total may increase carbon inventories by about 30 to 40 tonnes per hectare over about a 20- to 56-year period when displacing cropland. This is about doubling in storage over cropland and about one-half the storage in human-impacted forests. The sequestration benefit of wood energy crops over cropland would be negated in about 75 to 100 years by the use of fossil fuels to tend the plantations and handle biomass. Plantation interactions with other land uses and total landscape carbon inventory is important in assessing the relative role plantations play in terrestrial and atmospheric carbon dynamics. It is speculated that plantations, when viewed in this context. could trencrate a global leveling of net carbon emissions for approximately 10 to 20 years

  12. Immersion microcalorimetry of a carbon black

    International Nuclear Information System (INIS)

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

  13. Patterned functional carbon fibers from polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, Marcus A [ORNL; Saito, Tomonori [ORNL; Brown, Rebecca H [ORNL; Kumbhar, Amar S [University of North Carolina, Chapel Hill; Naskar, Amit K [ORNL

    2012-01-01

    Patterned, continuous carbon fibers with controlled surface geometry were produced from a novel melt-processible carbon precursor. This portends the use of a unique technique to produce such technologically innovative fibers in large volume for important applications. The novelties of this technique include ease of designing and fabricating fibers with customized surface contour, the ability to manipulate filament diameter from submicron scale to a couple of orders of magnitude larger scale, and the amenable porosity gradient across the carbon wall by diffusion controlled functionalization of precursor. The geometry of fiber cross-section was tailored by using bicomponent melt-spinning with shaped dies and controlling the melt-processing of the precursor polymer. Circular, trilobal, gear-shaped hollow fibers, and solid star-shaped carbon fibers of 0.5 - 20 um diameters, either in self-assembled bundle form, or non-bonded loose filament form, were produced by carbonizing functionalized-polyethylene fibers. Prior to carbonization, melt-spun fibers were converted to a char-forming mass by optimizing the sulfonation on polyethylene macromolecules. The fibers exhibited distinctly ordered carbon morphologies at the outside skin compared to the inner surface or fiber core. Such order in carbon microstructure can be further tuned by altering processing parameters. Partially sulfonated polyethylene-derived hollow carbon fibers exhibit 2-10 fold surface area (50-500 m2/g) compared to the solid fibers (10-25 m2/g) with pore sizes closer to the inside diameter of the filaments larger than the sizes on the outer layer. These specially functionalized carbon fibers hold promise for extraordinary performance improvements when used, for example, as composite reinforcements, catalyst support media, membranes for gas separation, CO2 sorbents, and active electrodes and current collectors for energy storage applications.

  14. Deglacial climate, carbon cycle and ocean chemistry changes in response to a terrestrial carbon release

    Science.gov (United States)

    Simmons, C. T.; Matthews, H. D.; Mysak, L. A.

    2016-02-01

    Researchers have proposed that a significant portion of the post-glacial rise in atmospheric CO2 could be due to the respiration of permafrost carbon stocks that formed over the course of glaciation. In this paper, we used the University of Victoria Earth System Climate Model v. 2.9 to simulate the deglacial and interglacial carbon cycle from the last glacial maximum to the present. The model's sensitivity to mid and high latitude terrestrial carbon storage is evaluated by including a 600 Pg C carbon pool parameterized to respire in concert with decreases in ice sheet surface area. The respiration of this stored carbon during the early stages of deglaciation had a large effect on the carbon cycle in these simulations, allowing atmospheric CO2 to increase by 40 ppmv in the model, with an additional 20 ppmv increase occurring in the case of a more realistic, prescribed CO2 radiative warming. These increases occurred prior to large-scale carbon uptake due to the reestablishment of boreal forests and peatlands in the proxy record (beginning in the early Holocene). Surprisingly, the large external carbon input to the atmosphere and oceans did not increase sediment dissolution and mean ocean alkalinity relative to a control simulation without the high latitude carbon reservoir. In addition, our simulations suggest that an early deglacial terrestrial carbon release may come closer to explaining some observed deglacial changes in deep-ocean carbonate concentrations than simulations without such a release. We conclude that the respiration of glacial soil carbon stores may have been an important contributor to the deglacial CO2 rise, particularly in the early stages of deglaciation.

  15. Modelling carbon overconsumption and the formation of extracellular particulate organic carbon

    Directory of Open Access Journals (Sweden)

    M. Schartau

    2007-01-01

    Full Text Available During phytoplankton growth a fraction of dissolved inorganic carbon (DIC assimilated by phytoplankton is exuded in the form of dissolved organic carbon (DOC, which can be transformed into extracellular particulate organic carbon (POC. A major fraction of extracellular POC is associated with carbon of transparent exopolymer particles (TEP; carbon content = TEPC that form from dissolved polysaccharides (PCHO. The exudation of PCHO is linked to an excessive uptake of DIC that is not directly quantifiable from utilisation of dissolved inorganic nitrogen (DIN, called carbon overconsumption. Given these conditions, the concept of assuming a constant stoichiometric carbon-to-nitrogen (C:N ratio for estimating new production of POC from DIN uptake becomes inappropriate. Here, a model of carbon overconsumption is analysed, combining phytoplankton growth with TEPC formation. The model describes two modes of carbon overconsumption. The first mode is associated with DOC exudation during phytoplankton biomass accumulation. The second mode is decoupled from algal growth, but leads to a continuous rise in POC while particulate organic nitrogen (PON remains constant. While including PCHO coagulation, the model goes beyond a purely physiological explanation of building up carbon rich particulate organic matter (POM. The model is validated against observations from a mesocosm study. Maximum likelihood estimates of model parameters, such as nitrogen- and carbon loss rates of phytoplankton, are determined. The optimisation yields results with higher rates for carbon exudation than for the loss of organic nitrogen. It also suggests that the PCHO fraction of exuded DOC was 63±20% during the mesocosm experiment. Optimal estimates are obtained for coagulation kernels for PCHO transformation into TEPC. Model state estimates are consistent with observations, where 30% of the POC increase was attributed to TEPC formation. The proposed model is of low complexity and is

  16. Modelling carbon overconsumption and the formation of extracellular particulate organic carbon

    Directory of Open Access Journals (Sweden)

    C. Völker

    2007-07-01

    Full Text Available During phytoplankton growth a fraction of dissolved inorganic carbon (DIC assimilated by phytoplankton is exuded in the form of dissolved organic carbon (DOC, which can be transformed into extracellular particulate organic carbon (POC. A major fraction of extracellular POC is associated with carbon of transparent exopolymer particles (TEP; carbon content = TEPC that form from dissolved polysaccharides (PCHO. The exudation of PCHO is linked to an excessive uptake of DIC that is not directly quantifiable from utilisation of dissolved inorganic nitrogen (DIN, called carbon overconsumption. Given these conditions, the concept of assuming a constant stoichiometric carbon-to-nitrogen (C:N ratio for estimating new production of POC from DIN uptake becomes inappropriate. Here, a model of carbon overconsumption is analysed, combining phytoplankton growth with TEPC formation. The model describes two modes of carbon overconsumption. The first mode is associated with DOC exudation during phytoplankton biomass accumulation. The second mode is decoupled from algal growth, but leads to a continuous rise in POC while particulate organic nitrogen (PON remains constant. While including PCHO coagulation, the model goes beyond a purely physiological explanation of building up carbon rich particulate organic matter (POM. The model is validated against observations from a mesocosm study. Maximum likelihood estimates of model parameters, such as nitrogen- and carbon loss rates of phytoplankton, are determined. The optimisation yields results with higher rates for carbon exudation than for the loss of organic nitrogen. It also suggests that the PCHO fraction of exuded DOC was 63±20% during the mesocosm experiment. Optimal estimates are obtained for coagulation kernels for PCHO transformation into TEPC. Model state estimates are consistent with observations, where 30% of the POC increase was attributed to TEPC formation. The proposed model is of low complexity and is

  17. Production process for boron carbide coated carbon material and boron carbide coated carbon material obtained by the production process

    International Nuclear Information System (INIS)

    A boron carbide coated carbon material is used for a plasma facing material of a thermonuclear reactor. The surface of a carbon material is chemically reacted with boron oxide to convert it into boron carbide. Then, it is subjected to heat treatment at a temperature of not lower than 1600degC in highly evacuated or inactive atmosphere to attain a boron carbide coated carbon material. The carbon material used is an artificial graphite or a carbon fiber reinforced carbon composite material. In the heat treatment, when the atmosphere is in vacuum, it is highly evacuated to less than 10Pa. Alternatively, in a case of inactive atmosphere, argon or helium gas each having oxygen and nitrogen content of not more than 20ppm is used. With such procedures, there can be obtained a boron carbide-coated carbon material with low content of oxygen and nitrogen impurities contained in the boron carbide coating membrane thereby hardly releasing gases. (I.N.)

  18. Mechanisms of soil carbon storage in experimental grasslands

    Science.gov (United States)

    Steinbeiss, S.; Temperton, V. M.; Gleixner, G.

    2007-10-01

    We investigated the fate of root and litter derived carbon into soil organic matter and dissolved organic matter in soil profiles, in order to explain unexpected positive effects of plant diversity on carbon storage. A time series of soil and soil solution samples was investigated at the field site of The Jena Experiment. In addition to the main biodiversity experiment with C3 plants, a C4 species (Amaranthus retroflexus L.) naturally labeled with 13C was grown on an extra plot. Changes in organic carbon concentration in soil and soil solution were combined with stable isotope measurements to follow the fate of plant carbon into the soil and soil solution. A split plot design with plant litter removal versus double litter input simulated differences in biomass input. After 2 years, the no litter and double litter treatment, respectively, showed an increase of 381 g C m-2 and 263 g C m-2 to 20 cm depth, while 71 g C m-2 and 393 g C m-2 were lost between 20 and 30 cm depth. The isotopic label in the top 5 cm indicated that 11 and 15% of soil organic carbon were derived from plant material on the no litter and the double litter treatment, respectively. Without litter, this equals the total amount of carbon newly stored in soil, whereas with double litter this corresponds to twice the amount of stored carbon. Our results indicate that litter input resulted in lower carbon storage and larger carbon losses and consequently accelerated turnover of soil organic carbon. Isotopic evidence showed that inherited soil organic carbon was replaced by fresh plant carbon near the soil surface. Our results suggest that primarily carbon released from soil organic matter, not newly introduced plant organic matter, was transported in the soil solution and contributed to the observed carbon storage in deeper horizons.

  19. Quantitative analysis of carbon in plutonium

    International Nuclear Information System (INIS)

    The aim of this study is to develop a method for the determination of carbon traces (20 to 400 ppm) in plutonium. The development of a carbon in plutonium standard is described, then the content of this substance is determined and its validity as a standard shown by analysis in two different ways. In the first method used, reaction of the metal with sulphur and determination of carbon as carbon sulphide, the following parameters were studied: influence of excess reagent, surface growth of samples in contact with sulphur, temperature and reaction time. The results obtained are in agreement with those obtained by the conventional method of carbon determination, combustion in oxygen and measurement of carbon in the form of carbon dioxide. Owing to the presence of this standard we were then able to study the different parameters involved in plutonium combustion so that the reaction can be made complete: temperature reached during combustion, role of flux, metal surface in contact with oxygen and finally method of cleaning plutonium samples

  20. Carbon Activation Diagnostic for Tertiary Neutron Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Glebov, V.Yu.; Stoeckl, C.; Sangster, T.C.; Meyerhofer, D.D.; Radha, P.B.; Padalino, S.; Baumgart, L.; Fuschino, J.

    2003-03-28

    OAK B202 The yield of tertiary neutrons with energies greater than 20 MeV has been proposed to determine the high rho R of inertial confinement fusion targets. The activation of carbon is a valuable measurement technique because of its high reaction threshold, the availability of high-purity samples, and relatively low cost. The 12C(n,2n)11C reaction has a Q value of 18.7 MeV, well above the 14.1 MeV primary DT neutron energy. The isotope 11C decays with a half-life of 20.3 min and emits a positron, resulting in the production of two back-to-back, 511 keV gamma rays upon annihilation. The positron decay of 11C is nearly identical to the copper decay used in the activation measurements of 14.1 MeV primary DT yields; therefore, the present copper activation gamma-detection system can be used to detect the tertiary-produced carbon activation. Because the tertiary neutron yield is more than six orders of magnitude lower than primary neutron yield, the carbon activation diagnostic requires ultrapure carbon samples, free from any positron-emitting contamination. In recent years we have developed carbon purification, packaging, and handling procedures that minimize the contamination signal to a level low enough to use carbon activation for tertiary neutron measurements in direct-drive implosion experiments with DT cryogenic targets on OMEGA. Experimental results of contamination measurements in carbon samples performed on high-neutron-yield shots on OMEGA in 2001-2002 will be presented. A concept for implementing a carbon activation system on the National Ignition Facility (NIF)will be discussed.

  1. Electroprecipitation of potassium americyl carbonate from potassium carbonate solutions

    International Nuclear Information System (INIS)

    Precipitation of potassium americyl carbonate was carried out at multigram scale by oxidizing americium(III) at the platinum anode in 3M K2CO3 solutions. Early investigations were conducted on pure americium 241 solutions on the 10 to 40 mg scale, in order to study the different parameters of the electrolysis, and to prove the feasibility of the process. Further experiments were performed on the 20 g scale, in impure americium 241 solutions. Electrolysis performed at 600C with a platinum grid as the anode, and a tantalum rod immersed in a cathodic compartment, precipitated 20 g of americium 241 with yields above 99% in 2 h. The electroprecipitation process presents the advantage of being clean and suitable for automation techniques in comparison with the chemical oxidation process using potassium persulphate. (orig.)

  2. Electroprecipitation of potassium americyl carbonate from potassium carbonate solutions

    International Nuclear Information System (INIS)

    Precipitation of potassium americyl carbonate was carried out at multigram scale by oxidizing at platinum anode Am(III) in 3 M K2CO3 solutions. Early investigations were conducted on pure americium 241 solutions on 10 to 40 mg scale, in order to study the different parameters of the electrolysis, and to prove the faisability of the process. Further experiments have been performed on the 20 grams scale, in impure americium 241 solutions. Electrolysis performed at 600C with platinum grid as anode, and tantalum rod immersed in a cathodic compartment, precipitates 20 grams of americium 241 with yields above 99% in two hours. The electroprecipitation process presents the advantage to be clean and suitable for automation technique in comparison with the chemical oxidation process using potassium persulfate

  3. Carbon nanotube cathode with capping carbon nanosheet

    Science.gov (United States)

    Li, Xin; Zhao, Dengchao; Pang, Kaige; Pang, Junchao; Liu, Weihua; Liu, Hongzhong; Wang, Xiaoli

    2013-10-01

    Here, we report a vertically aligned carbon nanotube (VACNT) film capped with a few layer of carbon nanosheet (FLCN) synthesized by chemical vapor deposition using a carbon source from iron phthalocyanine pyrolysis. The square resistance of the VACNT film is significantly reduced from 1500 Ω/□ to 300 Ω/□ when it is capped with carbon nanosheet. The VACNT capped with carbon nanosheet was transferred to an ITO glass substrate in an inverted configuration so that the carbon nanosheet served as a flexible transparent electrode at the bottom and the VACNT roots served as emission tips. Because all of the VACNTs start growing from a flat silicon substrate, the VACNT roots are very neat and uniform in height. A field emission test of the carbon nanosheet-capped VACNT film proved that the CNT roots show better uniformity in field emission and the carbon nanosheet cap could also potentially serve as a flexible transparent electrode, which is highly desired in photo-assisted field emission.

  4. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the ROGER REVELLE in the South Pacific Ocean from 1997-10-20 to 1997-11-24 (NODC Accession 0116068)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0116068 includes chemical, discrete sample, physical and profile data collected from ROGER REVELLE in the South Pacific Ocean from 1997-10-20 to...

  5. 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 ROGER REVELLE in the Indian Ocean from 2009-03-20 to 2009-05-15 (NODC Accession 0108075)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0108075 includes discrete sample and profile data collected from ROGER REVELLE in the Indian Ocean from 2009-03-20 to 2009-05-15. These data include...

  6. 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 Hokusei Maru in the North Pacific Ocean from 1992-06-20 to 1992-07-05 (NODC Accession 0112233)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112233 includes chemical, discrete sample, physical and profile data collected from Hokusei Maru in the North Pacific Ocean from 1992-06-20 to...

  7. 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 Hokusei Maru in the North Pacific Ocean from 1992-06-20 to 1992-07-05 (NODC Accession 0112235)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112235 includes chemical, discrete sample, physical and profile data collected from Hokusei Maru in the North Pacific Ocean from 1992-06-20 to...

  8. 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 Hokusei Maru in the North Pacific Ocean from 1992-06-20 to 1992-07-05 (NODC Accession 0112234)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112234 includes chemical, discrete sample, physical and profile data collected from Hokusei Maru in the North Pacific Ocean from 1992-06-20 to...

  9. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from DISCOVERY in the Davis Strait, Labrador Sea and North Atlantic Ocean from 2008-08-20 to 2008-09-25 (NODC Accession 0108367)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0108367 includes discrete sample and profile data collected from DISCOVERY in the Davis Strait, Labrador Sea and North Atlantic Ocean from 2008-08-20...

  10. 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 RYOFU MARU in the North Pacific Ocean and Philippine Sea from 2000-06-20 to 2000-07-31 (NODC Accession 0112278)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0112278 includes discrete sample and profile data collected from RYOFU MARU in the North Pacific Ocean and Philippine Sea from 2000-06-20 to...

  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. 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 ...

  13. Sodium carbonate poisoning

    Science.gov (United States)

    Sodium carbonate (known as washing soda or soda ash) is a chemical found in many household and ... products. This article focuses on poisoning due to sodium carbonate. This article is for information only. Do ...

  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 Information Center

    Medline Plus

    Full Text Available ... Home / Safety Education / Safety Education Centers En Español Carbon Monoxide Information Center The Invisible Killer Carbon monoxide, also known as CO, is called the "Invisible ...

  16. 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 ...

  17. 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...

  18. 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 ...

  19. 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 ...

  20. 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.

  1. 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.

  2. Carbon cycle uncertainty in the Alaskan Arctic

    Directory of Open Access Journals (Sweden)

    J. B. Fisher

    2014-02-01

    Full Text Available Climate change is leading to a disproportionately large warming in the high northern latitudes, but the magnitude and sign of the future carbon balance of the Arctic are highly uncertain. Using 40 terrestrial biosphere models for Alaska, we provide a baseline of terrestrial carbon cycle structural and parametric uncertainty, defined as the multi-model standard deviation (σ against the mean (x for each quantity. Mean annual uncertainty (σ/x was largest for net ecosystem exchange (NEE (−0.01± 0.19 kg C m−2 yr−1, then net primary production (NPP (0.14 ± 0.33 kg C m−2 yr−1, autotrophic respiration (Ra (0.09 ± 0.20 kg C m−2 yr−1, gross primary production (GPP (0.22 ± 0.50 kg C m−2 yr−1, ecosystem respiration (Re (0.23 ± 0.38 kg C m−2 yr−1, CH4 flux (2.52 ± 4.02 g CH4 m−2 yr−1, heterotrophic respiration (Rh (0.14 ± 0.20 kg C m−2 yr−1, and soil carbon (14.0± 9.2 kg C m−2. The spatial patterns in regional carbon stocks and fluxes varied widely with some models showing NEE for Alaska as a strong carbon sink, others as a strong carbon source, while still others as carbon neutral. Additionally, a feedback (i.e., sensitivity analysis was conducted of 20th century NEE to CO2 fertilization (β and climate (γ, which showed that uncertainty in γ was 2x larger than that of β, with neither indicating that the Alaskan Arctic is shifting towards a certain net carbon sink or source. Finally, AmeriFlux data are used at two sites in the Alaskan Arctic to evaluate the regional patterns; observed seasonal NEE was captured within multi-model uncertainty. This assessment of carbon cycle uncertainties may be used as a baseline for the improvement of experimental and modeling activities, as well as a reference for future trajectories in carbon cycling with climate change in the Alaskan Arctic.

  3. 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.

  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. Preparation of Magnesium Carbonate Whisker from Magnesite Tailings

    Energy Technology Data Exchange (ETDEWEB)

    Wang, N; Chen, M [School of Materials and Metallurgy, Northeastern University, Shenyang 110004 (China); Ni, H W, E-mail: chenm@smm.neu.edu.cn [Wuhan University of Science and Technology, Wuhan 430081 (China)

    2011-10-29

    Magnesium carbonate whisker was prepared by thermal decomposition of Mg(HCO{sub 3}){sub 2} solution that was prepared through hydration and carbonation of light burnt magnesia derived from magnesite tailings. The effects of thermal decomposition conditions on the morphology of magnesium carbonate crystal were investigated. The results showed that thermal decomposition product was MgCO{sub 3{center_dot}}3H{sub 2}O, and its crystal morphology was appreciably influenced by the additives added to Mg(HCO{sub 3}){sub 2} solution. Magnesium carbonate whiskers were successfully prepared when a kind of soluble magnesium salt was added, and magnesium carbonate whiskers with the length of 20 to 60{mu}m and aspect ratio of 10{approx}20 were obtained under the condition of 50deg. C thermal decomposition temperature and 200 rpm stirring intensity.

  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. Microstructural Features During Strain Induced Ferrite Transformation in 08 and 20Mn Steels

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The microstructure evolution during strain induced ferrite transformation was followed in thermal-simulation tests of clean 08 and 20Mn steels. The influences of carbon equivalence and initial austenite grain size on ferrite grain refinement and the volume fraction of ferrite during straining were inspected. The results revealed that the accelerating effect of ferrite transformation by strain was increased as the carbon equivalence decreased. However, finer ferrite grains were obtained at higher carbon content. At strain of ~1.5 ferrite grains less than 3m and 2m can be obtained in 08 and 20Mn steels respectively. Whereas the ferrite grain refinement in 08 steel was due to both effects of strain induced transformation and ferrite dynamic recrystallization, that in 20Mn was mainly due to strain induced transformation. Heavy strain can produce fine ferrite grains in coarse austenite grained 08 steel, but it would lead to band microstructure in coarse austenite grained 20Mn.

  8. Institute a modest carbon tax to reduce carbon emissions, finance clean energy technology development, cut taxes, and reduce the deficit

    Energy Technology Data Exchange (ETDEWEB)

    Muro, Mark; Rothwell, Jonathan

    2012-11-15

    The nation should institute a modest carbon tax in order to help clean up the economy and stabilize the nation’s finances. Specifically, Congress and the president should implement a $20 per ton, steadily increasing carbon excise fee that would discourage carbon dioxide emissions while shifting taxation onto pollution, financing energy efficiency (EE) and clean technology development, and providing opportunities to cut taxes or reduce the deficit. The net effect of these policies would be to curb harmful carbon emissions, improve the nation’s balance sheet, and stimulate job-creation and economic renewal.

  9. Catalytic growth of carbon nanotubes with large inner diameters

    Directory of Open Access Journals (Sweden)

    WEI REN ZHONG

    2005-02-01

    Full Text Available Carbon nanotubes (2.4 g/g catalyst, with large inner diameters were successfully synthesized through pyrolysis of methane on a Ni–Cu–Al catalyst by adding sodium carbonate into the carbon nanotubes growth system. The inner diameter of the carbon nanotubes prepared by this method is about 20–60 nm, while their outer diameter is about 40–80 nm. Transmission electron microscopy and X-ray diffraction were employed to investigate the morphology and microstructures of the carbon nanotubes. The analyses showed that these carbon nanotubes have large inner diameters and good graphitization. The addition of sodium carbonate into the reaction system brings about a slight decrease in the methane conversion and the yield of carbon. The experimental results showed that sodium carbonate is a mildly toxic material which influenced the catalytic activity of the Ni–Cu–Al catalyst and resulted in the formation of carbon nanotubes with large inner diameters. The growth mechanism of the carbon nanotubes with large inner diameters is discussed in this paper.

  10. Microstructure and mechanical behavior of a novel Co20Ni20Fe20Al20Ti20 alloy fabricated by mechanical alloying and spark plasma sintering

    International Nuclear Information System (INIS)

    A novel equiatomic Co20Ni20Fe20Al20Ti20 (at%) alloy was designed and synthesized to study the effect of high atomic concentrations of Al and Ti elements on the microstructure, phase composition and mechanical behavior of high-entropy alloys (HEAs) fabricated by mechanical alloying (MA) and spark plasma sintering (SPS). Following the MA process, the Co20Ni20Fe20Al20Ti20 alloy was composed of a primary body-centered cubic (BCC) supersaturated solid solution and a face-centered cubic (FCC) supersaturated solid solution. However, following SPS, a primary FCC solid-solution phase, a BCC solid-solution phase and a trace amount of Al3Ti intermetallics were observed. Transmission electron microscopy (TEM) results confirmed the presence of the FCC solid-solution phase, the BCC (B2-type) solid-solution phase and Al3Ti intermetallics in the bulk alloy. The FCC and B2-type phases are ultrafine-grained, and Al3Ti intermetallics is nano/ultrafine-grained. Our results suggest that consideration of a single existing empirical design criterion is inadequate to explain phase formation in the Co20Ni20Fe20Al20Ti20 alloy. Solid-solution strengthening, grain-boundary strengthening, twin-boundary strengthening, the presence of the strong B2-type BCC phase, and precipitate strengthening due to the presence of a trace amount of Al3Ti are responsible for the ultra-high compressive strength of ~2988 MPa and hardness of ~704 Hv. The strain-to-failure of ~5.8% with visible ductility is dominated by the FCC solid-solution phase

  11. Activated carbons and gold

    International Nuclear Information System (INIS)

    The literature on activated carbon is reviewed so as to provide a general background with respect to the effect of source material and activation procedure on carbon properties, the structure and chemical nature of the surface of the activated carbon, and the nature of absorption processes on carbon. The various theories on the absorption of gold and silver from cyanide solutions are then reviewed, followed by a discussion of processes for the recovery of gold and silver from cyanide solutions using activated carbon, including a comparison with zinc precipitation

  12. Carbon emissions of infrastructure development.

    Science.gov (United States)

    Müller, Daniel B; Liu, Gang; Løvik, Amund N; Modaresi, Roja; Pauliuk, Stefan; Steinhoff, Franciska S; Brattebø, Helge

    2013-10-15

    Identifying strategies for reconciling human development and climate change mitigation requires an adequate understanding of how infrastructures contribute to well-being and greenhouse gas emissions. While direct emissions from infrastructure use are well-known, information about indirect emissions from their construction is highly fragmented. Here, we estimated the carbon footprint of the existing global infrastructure stock in 2008, assuming current technologies, to be 122 (-20/+15) Gt CO2. The average per-capita carbon footprint of infrastructures in industrialized countries (53 (± 6) t CO2) was approximately 5 times larger that that of developing countries (10 (± 1) t CO2). A globalization of Western infrastructure stocks using current technologies would cause approximately 350 Gt CO2 from materials production, which corresponds to about 35-60% of the remaining carbon budget available until 2050 if the average temperature increase is to be limited to 2 °C, and could thus compromise the 2 °C target. A promising but poorly explored mitigation option is to build new settlements using less emissions-intensive materials, for example by urban design; however, this strategy is constrained by a lack of bottom-up data on material stocks in infrastructures. Infrastructure development must be considered in post-Kyoto climate change agreements if developing countries are to participate on a fair basis. PMID:24053762

  13. Distribution Characteristic of Soil Organic Carbon Fraction in Different Types of Wetland in Hongze Lake of China

    OpenAIRE

    2014-01-01

    Soil organic carbon fractions included microbial biomass carbon (MBC), dissolved organic carbon (DOC), and labile organic carbon (LOC), which was investigated over a 0–20 cm depth profile in three types of wetland in Hongze Lake of China. Their ecoenvironmental effect and the relationships with soil organic carbon (SOC) were analyzed in present experiment. The results showed that both active and SOC contents were in order reduced by estuarine wetland, flood plain, and out-of-lake wetland. Pea...

  14. 137Cesium and soil carbon in a small agricultural watershed

    International Nuclear Information System (INIS)

    Scientific, political, and social interests have developed recently in the concept of using agricultural soils to sequester carbon. Studies supporting this concept indicate that soil erosion and subsequent redeposition of eroded soils in the same field may establish an ecosystem disequilibrium that promotes the buildup of carbon on agricultural landscapes. The problem is to determine the patterns of soil erosion and redeposition on the landscape and to relate these to soil carbon patterns. Radioactive 137cesium (137Cs) can be used to estimate soil erosion patterns and, more importantly, redeposition patterns at the field level. The purpose of this study was to determine the relationship between 137Cs, soil erosion, and soil carbon patterns on a small agricultural watershed. Profiles of soils from an upland area and soils in an adjacent riparian system were collected in 5 cm increments and the concentrations of 137Cs and carbon were determined. 137Cs and carbon were uniformly mixed in the upper 15-20 cm of upland soils. 137Cs (Bq g-1) and carbon (%) in the upland soils were significantly correlated (r2=0.66). Carbon content of the 0-20 cm layer was higher (1.4±0.3%) in areas of soil deposition than carbon content (1.1±0.3%) in areas of soil erosion as determined by the 137Cs technique. These data suggest that measurements of 137Cs in the soils can be useful for understanding carbon distribution patterns in surface soil. Carbon content of the upland soils ranged from 0.5 to 1.9% with an average of 1.2±0.4% in the 0-20 cm layer while carbon below this upper tilled layer (20-30 cm) ranged from 0.2 to 1.5% with an average of 0.5±0.3%. Total carbon was 2.66 and 3.20 kg m-2 in the upper 20 cm and upper 30 cm of the upland soils, respectively. Carbon content of the 0-20 cm layer in the riparian system ranged from 1.1 to 67.0% with an average 11.7±17.1%. Carbon content below 20 cm ranged from 1.8 to 79.3% with an average of 18.3±17.5%. Soil carbon in the upper 20 cm

  15. 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

  16. ISS Expedition 20 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 20 from 05/2009-10/2009. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  17. Carbon taxation reform in the European Union. The options involved

    International Nuclear Information System (INIS)

    Even though the EU clearly leads the global fight against climate change and despite the additional reduction in emissions due to the global crisis and European recession, the ambitious objectives flagged in the '20-20-20 by 2020' strategy and 'climate-energy package' may be out of reach if a more resolute and consistent policy of carbon taxation is not rapidly put in place in the EU. In this paper, we detail and discuss the different options available for such European carbon taxation. Initially published in 'Revue de l'OFCE' No. 116

  18. Scaling of carbon erosion in Tore Supra

    Energy Technology Data Exchange (ETDEWEB)

    Marandet, Y., E-mail: yannick.marandet@univ-provence.fr [PIIM, CNRS-Universite de Provence, Marseille (France); Dachicourt, R.; Monier-Garbet, P.; Tsitrone, E. [Association Euratom-CEA, CEA/DSM/IRFM, CEA Cadarache (France); Reiter, D.; Boerner, P. [IEF-4 Plasmaphysik, Forschungszentrum Juelich GmbH, Association EURATOM-FZJ, TEC (Germany); Beaute, A.; Delchambre, E. [Association Euratom-CEA, CEA/DSM/IRFM, CEA Cadarache (France); Genesio, P. [PIIM, CNRS-Universite de Provence, Marseille (France); Naiim-Habib, M.; Gunn, J.P.; Kubic, M.; Pegourie, B.; Aniel, T.; Brosset, C.; Colledani, G.; Corre, Y.; Gauthier, E.; Martinez, A. [Association Euratom-CEA, CEA/DSM/IRFM, CEA Cadarache (France)

    2011-08-01

    The scaling law for carbon erosion in Tore Supra previously established by Hogan et al. ({Phi}{sub C}(C/s) = 5 x 10{sup 20}P{sub cond} (MW), where P{sub cond} is the conducted power) is revisited both from the experimental and the modelling point of view. New developments with the EIRENE code, that allow relating measured CII emission intensities to the total amount of carbon sputtered from the Toroidal Pumped Limiter, are presented. Recent measurements carried out at high input power show a good agreement with the database used to establish the scaling law.

  19. Measuring radioactive carbon with a liquid scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Petkov, T.

    1975-01-01

    Results are presented on the measurement of the soft beta emitter carbon-14 in a liquid scintillator by means of a single-channel scintillation spectrometer provided with a lucite light-guide. The scintillation solution had the composition: PPO-10 grams, POPOP-0.25 grams, naphthalene-100 grams, and dioxane-1 liter. The background count rate and counting efficiency were determined at a discrimination threshold of 2 V and an amplification of 54. Carbon-14 activities of 10 to 20 picocuries could be measured at 90% counting efficiency under the proper conditions. (SJR)

  20. Rapid Annealing Of Amorphous Hydrogenated Carbon

    Science.gov (United States)

    Alterovitz, Samuel A.; Pouch, John J.; Warner, Joseph D.

    1989-01-01

    Report describes experiments to determine effects of rapid annealing on films of amorphous hydrogenated carbon. Study represents first efforts to provide information for applications of a-C:H films where rapid thermal processing required. Major finding, annealing causes abrupt increase in absorption and concomitant decrease in optical band gap. Most of change occurs during first 20 s, continues during longer annealing times. Extend of change increases with annealing temperature. Researchers hypothesize abrupt initial change caused by loss of hydrogen, while gradual subsequent change due to polymerization of remaining carbon into crystallites or sheets of graphite. Optical band gaps of unannealed specimens on silicon substrates lower than those of specimens on quartz substrates.

  1. Forest and wood products role in carbon sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Sampson, R.N.

    1997-12-31

    An evaluation of the use of U.S. forests and forest products for carbon emission mitigation is presented. The current role of forests in carbon sequestration is described in terms of regional differences and forest management techniques. The potential for increasing carbon storage by converting marginal crop and pasture land, increasing timberland growth, reducing wildfire losses, and changing timber harvest methods is examined. Post-harvest carbon flows, environmental impacts of wood products, biomass energy crops, and increased use of energy-conserving trees are reviewed for their potential in reducing or offsetting carbon emissions. It is estimated that these techniques could offset 20 to 40 percent of the carbon emitted annually in the U.S. 39 refs., 5 tabs.

  2. Carbon Taxes. A Review of Experience and Policy Design Considerations

    Energy Technology Data Exchange (ETDEWEB)

    Sumner, Jenny [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bird, Lori [National Renewable Energy Lab. (NREL), Golden, CO (United States); Smith, Hillary [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2009-12-01

    State and local governments in the United States are evaluating a wide range of policies to reduce carbon emissions, including, in some instances, carbon taxes, which have existed internationally for nearly 20 years. This report reviews existing carbon tax policies both internationally and in the United States. It also analyzes carbon policy design and effectiveness. Design considerations include which sectors to tax, where to set the tax rate, how to use tax revenues, what the impact will be on consumers, and how to ensure emissions reduction goals are achieved. Emission reductions that are due to carbon taxes can be difficult to measure, though some jurisdictions have quantified reductions in overall emissions and other jurisdictions have examined impacts that are due to programs funded by carbon tax revenues.

  3. Carbon Taxes: A Review of Experience and Policy Design Considerations

    Energy Technology Data Exchange (ETDEWEB)

    Sumner, J.; Bird, L.; Smith, H.

    2009-12-01

    State and local governments in the United States are evaluating a wide range of policies to reduce carbon emissions, including, in some instances, carbon taxes, which have existed internationally for nearly 20 years. This report reviews existing carbon tax policies both internationally and in the United States. It also analyzes carbon policy design and effectiveness. Design considerations include which sectors to tax, where to set the tax rate, how to use tax revenues, what the impact will be on consumers, and how to ensure emissions reduction goals are achieved. Emission reductions that are due to carbon taxes can be difficult to measure, though some jurisdictions have quantified reductions in overall emissions and other jurisdictions have examined impacts that are due to programs funded by carbon tax revenues.

  4. Carbon activation process for increased surface accessibility in electrochemical capacitors

    Science.gov (United States)

    Doughty, Daniel H.; Eisenmann, Erhard T.

    2001-01-01

    A process for making carbon film or powder suitable for double capacitor electrodes having a capacitance of up to about 300 F/cm.sup.3 is disclosed. This is accomplished by treating in aqueous nitric acid for a period of about 5 to 15 minutes thin carbon films obtained by carbonizing carbon-containing polymeric material having a high degree of molecular directionality, such as polyimide film, then heating the treated carbon film in a non-oxidizing atmosphere at a non-graphitizing temperature of at least 350.degree. C. for about 20 minutes, and repeating alternately the nitric acid step and the heating step from 7 to 10 times. Capacitors made with this carbon may find uses ranging from electronic devices to electric vehicle applications.

  5. Preparation and study of ultra-low density carbon aerogel

    International Nuclear Information System (INIS)

    The ultra-low density resorcinol (R)-formaldehyde (F) aerogel and carbon aerogel were prepared via a sol-gel route, which density are 10 mg/cm3 and 20 mg/cm3, respectively. The microstructures and properties of the carbon aerogel were investigated by using scanning electron microscope, transmission electron microscope, pore size distribution measurement, and so on. The ultra-low density products are some tortuous chains consisting of carbon nanospheres ranging from 10 to 15 nm. The carbon nanosphere consists of nanoparticles whose sizes are about several nanometers. The surface area of the low-density carbon aerogel is 1 783.7 m2/g. The hydrogen adsorption capacity of the ultra-low density carbon aerogel is 4.4% (mass fraction) at liquid nitrogen temperature under atmospheric pressure. (authors)

  6. Interstellar Carbon Chains: Is Thermodynamics the Key?

    Science.gov (United States)

    Etim, Emmanuel; Chakrabarti, Sandip Kumar; Das, Ankan; Gorai, Prasanta; Arunan, Elangannan

    2016-07-01

    In an effort to further our interest in understanding basic chemistry of interstellar molecules, we carry out here an extensive investigation of the stabilities of interstellar carbon chains; C_n, H_2C_n, HC_nN and C_nX (X=N, O, Si, S, H, P, H^-, N^-). These sets of molecules account for about 20% of all the known interstellar and circumstellar molecules. Their high abundances therefore demand a serious attention. High level ab initio quantum chemical simulations are employed to accurately estimate enthalpy of formation, chemical reactivity indices; global hardness and softness; and other chemical parameters of these molecules. Chemical modeling of the abundances of these molecular species has also been performed. Of the 89 molecules considered from these groups, 47 have been astronomically observed, these observed molecules are found to be more stable with respect to other members of the group. Of the 47 observed molecules, 60% are odd number carbon chains. The reason for the high abundance of odd numbered carbon chains can easily be seen from the fact that they are more stable than the corresponding even number carbon chains. This further confirms the dominance of thermodynamics in interstellar formation processes as described in the Energy, Stability and Abundance (ESA) relationship. The next possible carbon chain molecule for astronomical observation in each group is proposed. The effect of kinetics in the formation processes of these carbon chains is shown to be largely dominated by thermodynamics.

  7. Organic carbon biostimulates rapid rhizodegradation of perchlorate.

    Science.gov (United States)

    Yifru, Dawit D; Nzengung, Valentine A

    2008-12-01

    Previous hydroponics and field studies identified phytodegradation and rhizodegradation as the two main mechanisms by which plants metabolize perchlorate. Plant uptake and phytodegradation of perchlorate is a slower and undesired process that poses ecological risks resulting from phytoaccumulation of some fraction of the perchlorate. Meanwhile, rhizodegradation is a more rapid and favored process involving perchlorate-degrading bacteria utilizing dissolved organic carbon (DOC) as a carbon and energy (electron) source to rapidly degrade perchlorate to innocuous chloride. In the present study, rhizodegradation of perchlorate by willow trees (Salix nigra) was biostimulated using electron sources obtained from natural and artificial carbon sources. In bioreactors provided with carbon sources as 500 mg/L DOC, 25 to 40 mg/L of initial perchlorate concentrations were removed to below the ion chromatography method detection limit of 2 microg/L in approximately 9 d. For planted controls provided with no electron donors, the time required for the complete removal of the same doses of perchlorate was up to 70 d. Enhancement of rhizodegradation by organic carbon reduced the phytoaccumulated fraction of perchlorate by an order of magnitude from approximately 430 to 20 mg/kg. The implication of the present study is that the high fraction uptake and phytoaccumulation of perchlorate in agricultural products and the recycling of perchlorate into the ecosystem can be significantly curtailed by supplying electron donors derived from organic carbon sources to the root zone of plants. PMID:18593217

  8. 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.

  9. 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

  10. Gears Based on Carbon Nanotubes

    Science.gov (United States)

    Jaffe, Richard; Han, Jie; Globus, Al; Deardorff, Glenn

    2005-01-01

    Gears based on carbon nanotubes (see figure) have been proposed as components of an emerging generation of molecular- scale machines and sensors. In comparison with previously proposed nanogears based on diamondoid and fullerene molecules, the nanotube-based gears would have simpler structures and are more likely to be realizable by practical fabrication processes. The impetus for the practical development of carbon-nanotube- based gears arises, in part, from rapid recent progress in the fabrication of carbon nanotubes with prescribed diameters, lengths, chiralities, and numbers of concentric shells. The shafts of the proposed gears would be made from multiwalled carbon nanotubes. The gear teeth would be rigid molecules (typically, benzyne molecules), bonded to the nanotube shafts at atomically precise positions. For fabrication, it may be possible to position the molecular teeth by use of scanning tunneling microscopy (STM) or other related techniques. The capability to position individual organic molecules at room temperature by use of an STM tip has already been demonstrated. Routes to the chemical synthesis of carbon-nanotube-based gears are also under investigation. Chemical and physical aspects of the synthesis of molecular scale gears based on carbon nanotubes and related molecules, and dynamical properties of nanotube- based gears, have been investigated by computational simulations using established methods of quantum chemistry and molecular dynamics. Several particularly interesting and useful conclusions have been drawn from the dynamical simulations performed thus far: The forces acting on the gears would be more sensitive to local molecular motions than to gross mechanical motions of the overall gears. Although no breakage of teeth or of chemical bonds is expected at temperatures up to at least 3,000 K, the gears would not work well at temperatures above a critical range from about 600 to about 1,000 K. Gear temperature could probably be controlled by

  11. Partial pressure of carbon dioxide, pH, dissolved oxygen and other variables collected from time series observations using SAMI-CO2, SAMI-pH, and other instruments from Buoy NH-20 off the coast of Newport, Oregon, United States, at the near bottom depth of ~125 meters from 2014-01-15 to 2015-08-25 (NCEI Accession 0145163)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Subset of moored data from Benthic Boundary Layer near shelfbreak at 44.65N off OR coast. Hydro stattion NH20, at ~124.5W. Approximate water depth ~127m. Sensors ~2...

  12. Effect of Synthesis Technique and Carbonate Content on the Crystallinity and Morphology of Carbonated Hydroxyapatite

    Institute of Scientific and Technical Information of China (English)

    Chia Ching Kee; Hanafi Ismail; Ahmad Fauzi Mohd Noor

    2013-01-01

    The syntheses of nanosized carbonated hydroxyapatite (CHA) were performed by comparing dropwise and direct pouring of acetone solution of Ca(NO3)2.4H20 into mixture of (NH4)2HP04 and NH4HC03 at room temperature controlled at pH 11.Direct pouring method was later applied to study the increment of carbonate content in syntheses.The as-synthesized powders were characterized by various characterization techniques.The crystallographic results of the produced powders were obtained from X-ray diffraction analysis,whilst the carbonate content in the produced powders was determined by the CHNS/O elemental analyzer.Fourier transform infrared analysis confirmed that the CHA powders formed were B-type.Field emission scanning electron microscopy revealed that the powders were highly agglomerated in nanosized range and hence energy filtered transmission electron microscopy was employed to show elongated particles which decreased with increasing carbonate content.

  13. Carbon-Carbon Composites as Recuperator Materials for Direct Gas Brayton Systems

    International Nuclear Information System (INIS)

    Of the numerous energy conversion options available for a space nuclear power plant (SNPP), one that shows promise in attaining reliable operation and high efficiency is the direct gas Brayton (GB) system. In order to increase efficiency, the GB system incorporates a recuperator that accounts for nearly half the weight of the energy conversion system (ECS). Therefore, development of a recuperator that is lighter and provides better performance than current heat exchangers could prove to be advantageous. The feasibility of a carbon-carbon (C/C) composite recuperator core has been assessed and a mass savings of 60% and volume penalty of 20% were projected. The excellent thermal properties, high-temperature capabilities, and low density of carbon-carbon materials make them attractive in the GB system, but development issues such as material compatibility with other structural materials in the system, such as refractory metals and superalloys, permeability, corrosion, joining, and fabrication must be addressed

  14. Coping with carbon: a near-term strategy to limit carbon dioxide emissions from power stations.

    Science.gov (United States)

    Breeze, Paul

    2008-11-13

    Burning coal to generate electricity is one of the key sources of atmospheric carbon dioxide emissions; so, targeting coal-fired power plants offers one of the easiest ways of reducing global carbon emissions. Given that the world's largest economies all rely heavily on coal for electricity production, eliminating coal combustion is not an option. Indeed, coal consumption is likely to increase over the next 20-30 years. However, the introduction of more efficient steam cycles will improve the emission performance of these plants over the short term. To achieve a reduction in carbon emissions from coal-fired plant, however, it will be necessary to develop and introduce carbon capture and sequestration technologies. Given adequate investment, these technologies should be capable of commercial development by ca 2020. PMID:18757277

  15. Carbon-Carbon Composites as Recuperator Material for Direct Gas Brayton Systems

    Energy Technology Data Exchange (ETDEWEB)

    RA Wolf

    2006-07-19

    Of the numerous energy conversion options available for a space nuclear power plant (SNPP), one that shows promise in attaining reliable operation and high efficiency is the direct gas Brayton (GB) system. In order to increase efficiency, the GB system incorporates a recuperator that accounts for nearly half the weight of the energy conversion system (ECS). Therefore, development of a recuperator that is lighter and provides better performance than current heat exchangers could prove to be advantageous. The feasibility of a carbon-carbon (C/C) composite recuperator core has been assessed and a mass savings of 60% and volume penalty of 20% were projected. The excellent thermal properties, high-temperature capabilities, and low density of carbon-carbon materials make them attractive in the GB system, but development issues such as material compatibility with other structural materials in the system, such as refractory metals and superalloys, permeability, corrosion, joining, and fabrication must be addressed.

  16. Facile synthesis of carbon nanofibers-bridged porous carbon nanosheets for high-performance supercapacitors

    Science.gov (United States)

    Jiang, Yuting; Yan, Jun; Wu, Xiaoliang; Shan, Dandan; Zhou, Qihang; Jiang, Lili; Yang, Deren; Fan, Zhuangjun

    2016-03-01

    A facile and one-step method is demonstrated to prepare carbon nanofibers (CNFs)-bridged porous carbon nanosheets (PCNs) through carbonization of the mixture of bacterial cellulose and potassium citrate. The CNFs bridge PCNs to form integrated porous carbon architecture with high specific surface area of 1037 m2 g-1, much higher than those of pure PCNs (381 m2 g-1) and CNFs (510 m2 g-1). As a consequence, the PCN/CNF composite displays high specific capacitance of 261 F g-1, excellent rate capability and outstanding cycling stability (97.6% of capacitance retention after 10000 cycles). Moreover, the assembled symmetric supercapacitor with PCN/CNF electrodes delivers an ultrahigh energy density of 20.4 Wh kg-1 and outstanding cycling life (94.8% capacitance retention after 10000 cycles) in an aqueous electrolyte.

  17. Accounting for forest carbon pool dynamics in product carbon footprints: Challenges and opportunities

    International Nuclear Information System (INIS)

    Modification and loss of forests due to natural and anthropogenic disturbance contribute an estimated 20% of annual greenhouse gas (GHG) emissions worldwide. Although forest carbon pool modeling rarely suggests a ‘carbon neutral’ flux profile, the life cycle assessment community and associated product carbon footprint protocols have struggled to account for the GHG emissions associated with forestry, specifically, and land use generally. Principally, this is due to underdeveloped linkages between life cycle inventory (LCI) modeling for wood and forest carbon modeling for a full range of forest types and harvest practices, as well as a lack of transparency in globalized forest supply chains. In this paper, through a comparative study of U.S. and Chinese coated freesheet paper, we develop the initial foundations for a methodology that rescales IPCC methods from the national to the product level, with reference to the approaches in three international product carbon footprint protocols. Due to differences in geographic origin of the wood fiber, the results for two scenarios are highly divergent. This suggests that both wood LCI models and the protocols need further development to capture the range of spatial and temporal dimensions for supply chains (and the associated land use change and modification) for specific product systems. The paper concludes by outlining opportunities to measure and reduce uncertainty in accounting for net emissions of biogenic carbon from forestland, where timber is harvested for consumer products. - Highlights: ► Typical life cycle assessment practice for consumer products often excludes significant land use change emissions when estimating carbon footprints. ► The article provides a methodology to rescale IPCC guidelines for product-level carbon footprints. ► Life cycle inventories and product carbon footprint protocols need more comprehensive land use-related accounting. ► Interdisciplinary collaboration linking the LCA and

  18. Lithium storage properties of multiwall carbon nanotubes prepared by CVD

    International Nuclear Information System (INIS)

    Full text: Multiwall carbon nanotubes (MWCNTs) were synthesised by chemical vapour deposition (CVD) method using acetylene gas. The XRD pattern of as prepared carbon nanotubes showed that the d002 value is 3.44 Angstroms. The morphology and microstructure of carbon nanotubes were characterized by HRTEM. Most of carbon nanotubes are entangled together to form bundles or ropes. The diameter of the carbon nanotubes is in the range of 10 ∼ 20 nm. There is a small amount of amorphous carbon particles presented in the sample. However, the yield of carbon nanotubes is more than 95%. Electrochemical properties of carbon nanotubes were characterised via a variety of electrochemical testing techniques. The result of CV test showed that the Li insertion potential is quite low, which is very close to O V versus Li+/Li reference electrode, whereas the potential for Li de-intercalation is in the range of 0.2-0.4 V. There exists a slight voltage hysteresis between Li intercalation and Li de-intercalation, which is similar to the other carbonaceous materials. The intensity of redox peaks of carbon nanotubes decrease with scanning cycle, indicating that the reversible Li insertion capacity gradually decreases. The carbon nanotubes electrode demonstrated a reversible lithium storage capacity of 340 mAh/g with good cyclability at moderate current density. Further improvement of Li storage capacity is possible by opening the end of carbon nanotubes to allow lithium insertion into inner graphene sheet of carbon nanotubes. The kinetic properties of lithium insertion in carbon nanotube electrodes were characterised by a.c. impedance measurements. It was found that the lithium diffusion coefficient dLi decreases with an increase of Li ion concentration in carbon nanotube host

  19. Novel phase of carbon, ferromagnetism, and conversion into diamond

    Science.gov (United States)

    Narayan, Jagdish; Bhaumik, Anagh

    2015-12-01

    We report the discovery of a new phase of carbon (referred to as Q-carbon) and address fundamental issues related to direct conversion of carbon into diamond at ambient temperatures and pressures in air without any need for catalyst and presence of hydrogen. The Q-carbon is formed as result of quenching from super undercooled state by using high-power nanosecond laser pulses. We discuss the equilibrium phase diagram (P vs. T) of carbon and show that by rapid quenching kinetics can shift thermodynamic graphite/diamond/liquid carbon triple point from 5000 K/12 GPa to super undercooled carbon at atmospheric pressure in air. It is shown that nanosecond laser heating of diamond-like amorphous carbon on sapphire, glass, and polymer substrates can be confined to melt carbon in a super undercooled state. By quenching the carbon from the super undercooled state, we have created a new state of carbon (Q-carbon) from which nanodiamond, microdiamond, microneedles, and single-crystal thin films are formed depending upon the nucleation and growth times allowed for diamond formation. The Q-carbon quenched from liquid is a new state of solid carbon with a higher mass density than amorphous carbon and a mixture of mostly fourfold sp3 (75%-85%) with the rest being threefold sp2 bonded carbon (with distinct entropy). It is expected to have new and improved mechanical hardness, electrical conductivity, chemical, and physical properties, including room-temperature ferromagnetism (RTFM) and enhanced field emission. Here we present interesting results on RTFM, enhanced electrical conductivity and surface potential of Q-carbon to emphasize its unique properties. The Q-carbon exhibits robust bulk ferromagnetism with estimated Curie temperature of about 500 K and saturation magnetization value of 20 emu g-1. From the Q-carbon, diamond phase is nucleated and a variety of micro- and nanostructures and large-area single-crystal diamond sheets are grown by allowing growth times as needed

  20. Novel phase of carbon, ferromagnetism, and conversion into diamond

    Energy Technology Data Exchange (ETDEWEB)

    Narayan, Jagdish, E-mail: narayan@ncsu.edu; Bhaumik, Anagh [Department of Materials Science and Engineering, Centennial Campus, North Carolina State University, Raleigh, North Carolina 27695-7907 (United States)

    2015-12-07

    We report the discovery of a new phase of carbon (referred to as Q-carbon) and address fundamental issues related to direct conversion of carbon into diamond at ambient temperatures and pressures in air without any need for catalyst and presence of hydrogen. The Q-carbon is formed as result of quenching from super undercooled state by using high-power nanosecond laser pulses. We discuss the equilibrium phase diagram (P vs. T) of carbon and show that by rapid quenching kinetics can shift thermodynamic graphite/diamond/liquid carbon triple point from 5000 K/12 GPa to super undercooled carbon at atmospheric pressure in air. It is shown that nanosecond laser heating of diamond-like amorphous carbon on sapphire, glass, and polymer substrates can be confined to melt carbon in a super undercooled state. By quenching the carbon from the super undercooled state, we have created a new state of carbon (Q-carbon) from which nanodiamond, microdiamond, microneedles, and single-crystal thin films are formed depending upon the nucleation and growth times allowed for diamond formation. The Q-carbon quenched from liquid is a new state of solid carbon with a higher mass density than amorphous carbon and a mixture of mostly fourfold sp{sup 3} (75%–85%) with the rest being threefold sp{sup 2} bonded carbon (with distinct entropy). It is expected to have new and improved mechanical hardness, electrical conductivity, chemical, and physical properties, including room-temperature ferromagnetism (RTFM) and enhanced field emission. Here we present interesting results on RTFM, enhanced electrical conductivity and surface potential of Q-carbon to emphasize its unique properties. The Q-carbon exhibits robust bulk ferromagnetism with estimated Curie temperature of about 500 K and saturation magnetization value of 20 emu g{sup −1}. From the Q-carbon, diamond phase is nucleated and a variety of micro- and nanostructures and large-area single-crystal diamond sheets are grown by allowing

  1. LabVIEW 8.20-20 Years of Innovation

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Introduction LabVIEW, a graphical development environment for measurement and automation introduced in 1986, has more than 20 years of innovation and continuous improvement. Although introduced as a tool for automating measurements from instruments, LabVIEW has evolved into a graphical system design platform for design, test, and control.

  2. Inferring Absorbing Organic Carbon Content from AERONET Data

    Science.gov (United States)

    Arola, A.; Schuster, G.; Myhre, G.; Kazadzis, S.; Dey, S.; Tripathi, S. N.

    2011-01-01

    Black carbon, light-absorbing organic carbon (often called brown carbon) and mineral dust are the major light-absorbing aerosols. Currently the sources and formation of brown carbon aerosol in particular are not well understood. In this study we estimated globally the amount of light absorbing organic carbon and black carbon from AERONET measurements. We find that the columnar absorbing organic carbon (brown carbon) levels in biomass burning regions of South-America and Africa are relatively high (about 15-20 magnesium per square meters during biomass burning season), while the concentrations are significantly lower in urban areas in US and Europe. However, we estimated significant absorbing organic carbon amounts from the data of megacities of newly industrialized countries, particularly in India and China, showing also clear seasonality with peak values up to 30-35 magnesium per square meters during the coldest season, likely caused by the coal and biofuel burning used for heating. We also compared our retrievals with the modeled organic carbon by global Oslo CTM for several sites. Model values are higher in biomass burning regions than AERONET-based retrievals, while opposite is true in urban areas in India and China.

  3. Basalt catalyzed carbonate precipitation reactions using carbon dioxide at low temperatures and low pressures

    Science.gov (United States)

    Petrik-Huff, C.; Finkelstein, D. B.; Mabee, S. B.

    2011-12-01

    Increased attention is being paid to basalts as host formations for the geologic sequestration of anthropogenically produced CO2. Here, we present preliminary results of batch experiments conducted on basalts from the Hartford Basin, the Deerfield and the Holyoke Basalt, to better constrain the optimum conditions to maximize carbon sequestration through the precipitation of carbonate. The purpose of this work is to explore options for CO2 sequestration in a locality where there is a lack of large geologic reservoirs appropriate for storage. In these experiments, 10 grams of 400 micron Deerfield and Holyoke basalt was reacted with deionized water for three hours both at and below supercritical conditions. These experiments showed carbonate precipitation of 15% was consistent at low pressures of CO2 (800 psi) both at high (100 Celsius) and low (20 Celsius) temperatures. These ranges of carbonate precipitation were greatest (15%) when CO2 was at low pressures. Experiments conducted at supercritical conditions precipitated a maximum of 4.7% carbonate. This information is valuable when considering alternative sequestration mechanisms that could be operated adjacent to power generation facilities or more industrial pure sources of CO2. The possibility of low pressure/temperature sequestration reactors to be operated in areas where transport to regional or national sequestration facilities may be cost prohibitive is a parallel course of action that should also be considered. Additionally, it is important to consider how a small ex-situ carbon sequestration project can help increase public acceptance of carbon capture and sequestration.

  4. Histone H4 Lysine 20 methylation

    DEFF Research Database (Denmark)

    Jørgensen, Stine; Schotta, Gunnar; Sørensen, Claus Storgaard

    2013-01-01

    compaction. The distinct H4K20 methylation states are mediated by SET8/PR-Set7 that catalyses monomethylation of H4K20, whereas SUV4-20H1 and SUV4-20H2 enzymes mediate further H4K20 methylation to H4K20me2 and H4K20me3. Disruption of these H4K20-specific histone methyltransferases leads to genomic...

  5. 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.

  6. Carbon-negative biofuels

    International Nuclear Information System (INIS)

    Current Kyoto-based approaches to reducing the earth's greenhouse gas problem involve looking for ways to reduce emissions. But these are palliative at best, and at worst will allow the problem to get out of hand. It is only through sequestration of atmospheric carbon that the problem can be solved. Carbon-negative biofuels represent the first potentially huge assault on the problem, in ways that are already technically feasible and practicable. The key to carbon negativity is to see it not as technically determined but as an issue of strategic choice, whereby farmers and fuel producers can decide how much carbon to return to the soil. Biochar amendment to the soil not only sequesters carbon but also enhances the fertility and vitality of the soil. The time is approaching when biofuels will be carbon negative by definition, and, as such, they will sweep away existing debates over their contribution to the solution of global warming. (author)

  7. Research on Eddy Current Testing System of the Carburized Layer Depth of 20CrMnTi Steel

    Institute of Scientific and Technical Information of China (English)

    CHENG Xiao-min; LI Na; WU Xin- wen; FANG Hua-bin

    2004-01-01

    In this paper the carbon distribution in the carburized layer of 20CrMnTi steel was studied. The relationship between the depth of a carburized layer and the surface carbon distribution was established. Eddy current testing system of the case depth of this carburized steel was built by using ANSYS software as second development platform.

  8. Hydrogen storage properties of carbon nanomaterials and carbon containing metal hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Maehlen, Jan Petter

    2003-07-01

    The topic of this thesis is structural investigations of carbon containing materials in respect to their hydrogen storage properties. This work was initially triggered by reports of extremely high hydrogen storage capacities of specific carbon nanostructures. It was decided to try to verify and understand the mechanisms in play in case of the existence of such high hydrogen densities in carbon. Two different routes towards the goal were employed; by studying selected hydrides with carbon as one of its constituents (mainly employing powder diffraction techniques in combination with hydrogen absorption and desorption measurements) and by carefully conducting hydrogen sorption experiments on what was believed to be the most ''promising'' carbon nanomaterial sample. In the latter case, a lot of effort was attributed to characterisations of different carbon nanomaterial containing samples with the aid of electron microscopy. Three different carbon-containing metal hydride systems, Y2C-H, YCoC-H and Y5SiC0.2-H, were examined. A relation between hydrogen occupation and the local arrangement of metal and carbon atoms surrounding the hydrogen sites was established. Several characteristic features of the compounds were noted in addition to solving the structure of the former unknown deuterideY5Si3C0.2D2.0 by the use of direct methods. Several carbon-nanomaterial containing samples were studied by means of transmission electron microscopy and powder diffraction, thus gaining knowledge concerning the structural aspects of nanomaterials. Based on these investigations, a specific sample containing a large amount of open-ended single-wall carbon nanotubes was chosen for subsequent hydrogen storage experiments. The latter experiments revealed moderate hydrogen storage capacities of the nanotubes not exceeding the values obtained for more conventional forms of carbon. These two different routes in investigating the hydrogen storage properties of carbon and

  9. Carbon monoxide poisoning

    OpenAIRE

    Dolan, Michael C.

    1985-01-01

    Carbon monoxide poisoning is a significant cause of illness and death. Its protean symptoms probably lead to a gross underestimation of its true incidence. Low levels of carbon monoxide aggravate chronic cardiopulmonary problems, and high levels are associated with cardiac arrhythmias and cerebral edema. Patients who survive acute poisoning are at risk of delayed neurologic sequelae. The measurement of carboxyhemoglobin levels does not reveal the tissue levels of carbon monoxide but is useful...

  10. The carbon dioxide cycle

    Science.gov (United States)

    James, P.B.; Hansen, G.B.; Titus, T.N.

    2005-01-01

    The seasonal CO2 cycle on Mars refers to the exchange of carbon dioxide between dry ice in the seasonal polar caps and gaseous carbon dioxide in the atmosphere. This review focuses on breakthroughs in understanding the process involving seasonal carbon dioxide phase changes that have occurred as a result of observations by Mars Global Surveyor. ?? 2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

  11. Carbon monoxide poisoning (acute)

    OpenAIRE

    Olson, Kent; Smollin, Craig

    2010-01-01

    The main symptoms of carbon monoxide poisoning are non-specific in nature and relate to effects on the brain and heart. The symptoms correlate poorly with serum carboxyhaemoglobin levels. People with comorbidity, elderly or very young people, and pregnant women are most susceptible.Carbon monoxide is produced by the incomplete combustion of carbon fuels, including inadequately ventilated heaters and car exhausts, or from chemicals such as methylene chloride paint stripper.Poisoning is cons...

  12. Carbon nanotubes decorating methods

    OpenAIRE

    A.D. Dobrzańska-Danikiewicz; D. Łukowiec; D. Cichock; W. Wolany

    2013-01-01

    Purpose: The work is to present and characterise various methods of depositing carbon nanotubes with nanoparticles of precious metals, and also to present the results of own works concerning carbon nanotubes coated with platinum nanoparticles.Design/methodology/approach: Electron transmission and scanning microscopy has been used for imaging the structure and morphology of the nanocomposites obtained and the distribution of nanoparticles on the surface of carbon nanotubes.Findings: The studie...

  13. Functionalization of Carbon Nanotubes

    OpenAIRE

    Abraham, Jürgen

    2005-01-01

    Carbon nanotubes have an enormous potential due to their outstanding electronic, optical, and mechanical properties. However, any technological application is still hindered due to problems regarding the processibility of the pristine carbon nanotubes. In the past few years, it has been shown that the chemical modification of the carbon nanotubes is an inevitable step prior to their application. The first part of this work (chapter 3.1) was focused on the purification of pristine laser ablati...

  14. In situ functionalisation of mesoporous carbon electrodes with carbon nanotubes for proton exchange membrane fuel-cell application

    International Nuclear Information System (INIS)

    In the work presented here, an attempt is made to study the effect of different carbon supports on the mesostructural properties as well as electrochemical behaviour of Pt/carbon supports. In this respect, the functionalised samples have been synthesised by using CMK-3, nickelocene as nickel source and the chemical vapour deposition (CVD) process for growth of carbon nanotubes. The platinum catalysts (Pt 20 wt.%) were obtained through a conventional wet impregnation method. All the materials have been characterised by XRD (small- and high-) angle, N2 adsorption–desorption isotherms, high-resolution transmission electron microscopy and high-resolution field emission scanning electron microscopy. The results showed that the mesostructural structure had been partially destroyed by functionalisation of CMK-3 with NiO and multiwalled carbon nanotubes (MWCNTs). Moreover, wide-angle X-ray diffraction (WAXRD) studies revealed the formation of smaller platinum crystallite sizes compared to Vulcan-supported samples. Furthermore, electrochemical evaluation indicates that CMK-3–CNT–20Pt gives a specific surface area of 58.9 m2 g−1. Finally, the polarisation curves for the fabricated membrane electrode assemblies (MEAs) with Pt loading of 0.5 mg cm−2 demonstrated that the CMK-3–CNT–20Pt catalyst shows better performance than industrial catalysts and even Vulcan–40% Pt. - Highlights: • In situ functionalisation of ordered mesoporous carbon with carbon nanotubes. • Novel electrocatalytic activity of functionalised mesostructured carbon. • Simultaneous effect of surface area and reactivity on electrocatalytic activity

  15. 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)

  16. Carbon Trading. Literature Overview

    International Nuclear Information System (INIS)

    From Pigou and Coase to the Kyoto Protocol, carbon trading has resulted in pricing of the negative externalities emanating from pollution. This report highlights leading literature and empirical findings on carbon trading, amongst others addressing the relevant carbon and related markets, the (lack of) success of carbon trading so far and room for improvement as well as its impact on investments in emission reduction. This report is part of a set of SEO-reports on finance and sustainability. The other reports deal with: Financing the Transition to Sustainable Energy; Innovations in financing environmental and social sustainability; and Sustainable investment.

  17. 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

  18. Global Carbon Cycle

    OpenAIRE

    Probst, Jean-Luc; Faure, Hugues; Veizer, Jan

    1999-01-01

    The European Union of Geosciences held its 9th biannual meeting in Strasbourg, March 23–27, 1997. During this meeting, Symposium N8 18, Global carbon Cycle, was held under the sponsorship of the IGCP 1 n8404 on the «Terrestrial Carbon in the past 125 Ka», the INQUA 2 Carbon Commission and the ESCOBA-Biosphere 3 project of the EC Environment and Climate Programme. The «Global Carbon Cycle» Symposium attracted 28 oral and poster presentations and about one hundred par...

  19. 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

  20. Changing global carbon cycle

    International Nuclear Information System (INIS)

    Full text: The increase in atmospheric carbon dioxide (C02) is the single largest human perturbation on the earth's radiative balance contributing to climate change. Its rate of change reflects the balance between anthropogenic carbon emissions and the dynamics of a number of terrestrial and ocean processes that remove or emit C02. It is the long term evolution of this balance that will determine to large extent the speed and magnitude of the human induced climate change and the mitigation requirements to stabilise atmospheric C02 concentrations at any given level. In this talk, we show new trends in global carbon sources and sinks, with particularly focus on major shifts occurring since 2000 when the growth rate of atmospheric C02 has reached its highest level on record. The acceleration in the C02 growth results from the combination of several changes in properties of the carbon cycle, including: acceleration of anthropogenic carbon emissions; increased carbon intensity of the global economy, and decreased efficiency of natural carbon sinks. We discuss in more detail some of the possible causes of the reduced efficiency of natural carbon sinks on land and oceans, such as the decreased net sink in the Southern Ocean and on terrestrial mid-latitudes due to world-wide occurrence of drought. All these changes reported here characterise a carbon cycle that is generating stronger than expected climate forcing, and sooner than expected

  1. AGS 20th anniversary celebration

    International Nuclear Information System (INIS)

    On May 22, 1980, a symposium was held at Brookhaven to celebrate the 20th birthday of the AGS, to recall its beginnings, and to review major discoveries that have been made with its beams. The talks at the symposium are recorded in this volume

  2. AGS 20th anniversary celebration

    Energy Technology Data Exchange (ETDEWEB)

    Baggett, N.V. (ed.)

    1980-05-22

    On May 22, 1980, a symposium was held at Brookhaven to celebrate the 20th birthday of the AGS, to recall its beginnings, and to review major discoveries that have been made with its beams. The talks at the symposium are recorded in this volume.

  3. Efficient organic carbon burial in the Bengal fan sustained by the Himalayan erosional system.

    Science.gov (United States)

    Galy, Valier; France-Lanord, Christian; Beyssac, Olivier; Faure, Pierre; Kudrass, Hermann; Palhol, Fabien

    2007-11-15

    Continental erosion controls atmospheric carbon dioxide levels on geological timescales through silicate weathering, riverine transport and subsequent burial of organic carbon in oceanic sediments. The efficiency of organic carbon deposition in sedimentary basins is however limited by the organic carbon load capacity of the sediments and organic carbon oxidation in continental margins. At the global scale, previous studies have suggested that about 70 per cent of riverine organic carbon is returned to the atmosphere, such as in the Amazon basin. Here we present a comprehensive organic carbon budget for the Himalayan erosional system, including source rocks, river sediments and marine sediments buried in the Bengal fan. We show that organic carbon export is controlled by sediment properties, and that oxidative loss is negligible during transport and deposition to the ocean. Our results indicate that 70 to 85 per cent of the organic carbon is recent organic matter captured during transport, which serves as a net sink for atmospheric carbon dioxide. The amount of organic carbon deposited in the Bengal basin represents about 10 to 20 per cent of the total terrestrial organic carbon buried in oceanic sediments. High erosion rates in the Himalayas generate high sedimentation rates and low oxygen availability in the Bay of Bengal that sustain the observed extreme organic carbon burial efficiency. Active orogenic systems generate enhanced physical erosion and the resulting organic carbon burial buffers atmospheric carbon dioxide levels, thereby exerting a negative feedback on climate over geological timescales. PMID:18004382

  4. Mineral Carbonation Employing Ultramafic Mine Waste

    Science.gov (United States)

    Southam, G.; McCutcheon, J.; Power, I. M.; Harrison, A. L.; Wilson, S. A.; Dipple, G. M.

    2014-12-01

    wetland (up to 1000 ppm), and dissolved inorganic carbon (> 20 mM C) were ideal for carbonate precipitation. Under optimum nutrient and magnesium inputs, a mass balance calculation using water chemistry data and hydromagnesite as the sole mineral product resulted in a carbon sequestration rate of 61 t C/ha/year.

  5. Economic effects of using carbon taxes to reduce carbon dioxide emissions in major OECD countries. Final report

    International Nuclear Information System (INIS)

    A tax on fossil fuels designed to obtain a 20 percent reduction in emissions of carbon dioxide by the year 2020 would lower output among major OECD nations by 1 to 3 1/2 percent. The tax required to achieve a 20% reduction in emissions of carbon dioxide by 2020 ranged from $489.4 (Sweden) per metric ton of carbon to $2,427.9 (Japan) per ton of carbon. The tax required for the U.S. was $720.6 per ton. In the U.S., a tax per $100 per ton of carbon would equate to a tax of $70.68 per short ton of coal, $11.42 per barrel of oil, $1.66 per MCF of natural gas and 0.27 per gallon of gasoline. The study is part of a multi-phase effort to gauge the economic consequences of various measures being discussed by the international community to mitigate the possibility of global climate change by limiting emissions of carbon dioxide from fossil fuel use. The study assumed that the carbon tax program would be revenue neutral in that increased revenues from the carbon tax would be offset by reductions in personal income taxes

  6. Nuclear pumping of a neutral carbon laser

    International Nuclear Information System (INIS)

    Nuclear pumped lasing on the neutral carbon line at 1.45 μ has been achieved in mixtures of He-CO, He-CO2, Ne-CO and Ne-CO2. A low thermal neutron flux of 2 x 1014 n/cm2-sec was required and delays of up to 5.5 ms were observed. Helium pressures ranged from 20-800 T, Ne from 100-200 T, CO from 0.25 to 20 mT and CO2 from 0.1 to 25 mT

  7. Building a low carbon society

    International Nuclear Information System (INIS)

    This paper presents the strategy of the European Union in the field of energy and climate change. At the heart of the package are three commitments to be met by 2020: to reduce greenhouse gas emissions by at least 20%, to ensure that 20% of final energy consumption is met with renewable sources, and to raise energy efficiency by 20%. This strategy is based on the scientific consensus drawn by the International Panel for Climate Change, and implements the EU political strategy to limit the anthropogenic temperature rise to no more than 2 oC. A Directive for the geological storage of CO2 is another integral part of the package. This should enable the development and subsequent deployment of zero emission power plants. From a research and technology perspective, the Strategic Energy Technology Plan (SET-Plan) lists several energy technologies which will be required to reconcile economic growth and a vision of a decarbonised society. The EU climate and energy package and the SET-Plan are part of the solution both to the climate crisis and to the current economic and financial crisis. They represent a green 'new deal' which will enhance the competitiveness of EU industry in an increasingly carbon-constrained world.

  8. Calcium silicate structure and carbonation shrinkage of a tobermorite-based material

    International Nuclear Information System (INIS)

    Carbonated autoclaved aerated concretes (AACs) show no shrinkage at a degree of carbonation approximately less than 20%. The 29Si MAS NMR spectrum showed that at a degree of carbonation less than 25%, the typical double-chain silicate anion structure of tobermorite-11A was well maintained and interlayer Ca ions were exchanged with protons. This corresponded to the absence of carbonation shrinkage at a degree of carbonation less than 20%. When the degree of carbonation increased from 25% to 50% up to 60%, the double-chain silicate anion structure of tobermorite-11A was decomposed and Ca ions in the Ca-O layers were dissolved, showing a possible mechanism of carbonation shrinkage

  9. Vision 20/20 : saving for the future Alberta advantage

    International Nuclear Information System (INIS)

    As part of the Alberta Vision 20/20 project, Alberta's past and present spending patterns on natural resources and choices for the future were examined. Trust funds in Alberta, Alaska, and Norway were also compared, in order to learn from other jurisdictions. This report presented findings from Phase 3 of Vision 2020. The objectives of the study were to provide insight on what Alberta's economic, social and policy landscape might look like in the coming decades given expected demographic changes; benchmark Alberta's performance on key economic and social indicators and analyze government performance in related policy areas; supply useful, accessible information and possible solutions to Albertans about some of the challenges that demographic change is likely to bring; encourage discussion of issues among Albertans, including legislators and the media; and, where appropriate, encourage actions to mitigate or alleviate foreseeable problems. The guiding principles of the Vision 20/20 were first presented. Alberta's fiscal context and labyrinth of savings funds were examined. A detailed explanation and literature review of resource trust funds in Norway, Alaska, and Alberta were then provided followed by a comparison of the Alberta, Alaska, and Norway funds. Last, the report presented Alberta's options and discussion as well as recommendations. It was recommended that Alberta's annual per capita spending should not exceed population growth and inflation; the province should consider transfers of additional resource revenue into the Heritage Fund in the manner of the state of Alaska; and the province should deposit between 30 per cent and 40 per cent of all nonrenewable resource revenues in the Heritage Fund annually. 38 refs., 4 tabs., 17 figs., 4 appendices

  10. 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

  11. F values for isoelectronic ions of carbon

    Science.gov (United States)

    Ganas, P. S.

    1981-10-01

    An analytic atomic independent particle model is used to generate wave functions for the valence and excited states of isoelectronic ions of carbon up to Z = 20. Using these wave functions in conjunction with the Born approximation and the Russell-Saunders LS-coupling scheme, f values are calculated for various transitions from the 2p2(3P0) ground state. The results are compared with those from other works.

  12. Deformation and Recrystallisation in Low Carbon Steels

    OpenAIRE

    Almojil, Marwan

    2010-01-01

    The annealing behaviour, including studies of recrystallisation kinetics anddevelopment of crystallographic texture, of two low carbon steels after different coldrolling reductions have been investigated using Optical Microscopy (OM), ElectronBack-Scatter Diffraction (EBSD) and Transmission Electron Microscopy (TEM).The primary recrystallisation behaviour of 20, 50, 70 and 90% cold rolled InterstitialFree (IF) and High Strength Low Alloy (HSLA) steels was studied. The HSLA wasinitially proces...

  13. Al current collector surface treatment and carbon nano tubes influences on Carbon / Carbon super-capacitors performances

    Energy Technology Data Exchange (ETDEWEB)

    Portet, C.; Taberna, P.L.; Simon, P. [Universite Paul Sabatier, CIRIMAT-LCMIE, 31 - Toulouse (France)

    2004-07-01

    Performances of 4 cm{sup 2} carbon/carbon super-capacitors cells using Al current collectors foils in organic electrolyte are presented; the improvement of electrode material has been investigated. In a first part, a surface treatment of the Al current collector is proposed in order to improve contact surface between the current collector and the active material leading to an internal resistance decrease. The process consists in an etching of the Al foil and is followed by a carbonaceous sol-gel deposit. Galvano-static cycling and Electrochemical Impedance Spectroscopy measurements of super-capacitors all assembled with treated Al foil were tested over 10,000 cycles: an ESR of 0.5 {omega} cm{sup 2} and a capacitance of 95 F g{sup -1} of activated carbon are obtained and performances remain stable during cycling. The second part is devoted to the study of Carbon Nano Tubes (CNTs) adding into the active material on the performances of super-capacitors. A content of 15% of CNTs appears to be the best composition; the ESR is 0.4 {omega} cm{sup 2} (20% lowered as compared to a cell using activated carbon based electrode) and the capacitance remain high 93 F g{sup -1} of carbonaceous active material. (authors)

  14. 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.

  15. Ocean carbon uptake and storage

    International Nuclear Information System (INIS)

    Full text: The ocean contains about 95% of the carbon in the atmosphere, ocean and land biosphere system, and is of fundamental importance in regulating atmospheric carbon dioxide concentrations. In the 1990s an international research effort involving Australia was established to determine the uptake and storage of anthropogenic C02 for all major ocean basins. The research showed that about 118 of the 244 + 20 billion tons of the anthropogenic carbon emitted through fossil fuel burning and cement production has been stored in the ocean since preindustrial times, thus helping reduce the rate of increase in atmospheric C02. The research also showed the terrestrial biosphere has been a small net source of C02 (39 ± 28 billion tons carbon) to the atmosphere over the same period. About 60% of the total ocean inventory of the anthropogenic C02 was found in the Southern Hemisphere, with most in the 300S to 500S latitude band. This mid-latitude band is where surface waters are subducted as Mode and Intermediate waters, which is a major pathway controlling ocean C02 uptake. High storage (23% of the total) also occurs in the North Atlantic, associated with deep water formation in that basin. The ocean uptake and storage is expected to increase in the coming decades as atmospheric C02 concentrations rise. However, a number of feedback mechanisms associated with surface warming, changes in circulation, and biological effects are likely to impact on the uptake capacity. The accumulation or storage-of the C02 in the ocean is also the major driver of ocean acidification with potential to disrupt marine ecosystems. This talk will describe the current understanding of the ocean C02 uptake and storage and a new international research strategy to detect how the ocean uptake and storage will evolve on interannual through decadal scales. Understanding the ocean response to increasing atmospheric C02 will be a key element in managing future C02 increases and establishing stabilisation

  16. Selective Oxidation of Amorphous Carbon Layers without Damaging Embedded Single Wall Carbon Nanotube Bundles

    Science.gov (United States)

    Choi, Young Chul; Lim, Seong Chu

    2013-11-01

    Single wall carbon nanotubes (SWCNTs) were synthesized by arc discharge, and then purified by selective oxidation of amorphous carbon layers that were found to encase SWCNT bundles and catalyst metal particles. In order to remove selectively the amorphous carbon layers with SWCNTs being intact, we have systematically investigated the thermal treatment conditions; firstly, setting the temperature by measuring the activation energies of SWCNTs and amorphous carbon layers, and then, secondly, finding the optimal process time. As a consequence, the optimal temperature and time for the thermal treatment was found to be 460 °C and 20 min, respectively. The complete elimination of surrounding amorphous carbon layers makes it possible to efficiently disperse the SWCNT bundles, resulting in high absorbance of SWCNT-ink. The SWCNTs which were thermal-treated at optimized temperature (460 °C) and duration (20 min) showed much better crystallinity, dispersibility, and transparent conducting properties, compared with as-synthesized and the nanotubes thermal-treated at different experimental conditions.

  17. Water and Carbon as Creators of Imbalances in Nature

    Science.gov (United States)

    Shlafman, L. M.; Kontar, V. A.

    2012-12-01

    Our studies are showing that the carbon and water are closely intertwined. There are many reasons to study the imbalance of water and carbon together. For example, in photosynthesis six molecules of water and six molecules of carbon dioxide have created one molecule of sugar and six molecules of oxygen. 6H2O + 6CO2 go C6H12O6 + 6O2 For water and carbon dioxide, regarding the point of view of the imbalance, this process is the creator of imbalance of the decreasing type. The concentration of water and carbon dioxide in the atmosphere will decrease. For oxygen this process is the creator of imbalance of the increasing type. The concentration of oxygen in the atmosphere will increase. Water and carbon dioxide can be created independently of each other. For example, water is obtained from combining two hydrogen atoms and one oxygen atom: 2 H2 + O2 go 2 H2O Carbon dioxide also is possible to create without water: Na2CO3 go Na2O + CO2 or CaCO3 go CaO + CO2 But it is very often the water and carbon dioxide made up simultaneously in one reaction. For example combustion of methane gives carbon dioxide and water: CH4 + 2 O2 go CO2 + 2 H2O Carbon dioxide can come up more complicated way. Initially created carbon monoxide and water 2 CH4 + 3 O2 go 2 CO + 4 H2O After then the carbon monoxide rapidly oxidized to carbon dioxide. The gasification of solid fuels is the reaction: C + H20 go CO + H2 In the next step carbon monoxide is oxidized to carbon dioxide, and hydrogen is oxidized to water. C3H8 + 5 O2 go 3 CO2 + 4 H2O By the incomplete combustion of propane will be produced some very interesting components: 2 C3H8 + 7 O2 go 8 H2O + 2 CO2 + 2 CO + 2 C It will be water, carbon dioxide, carbon monoxide and pure carbon. Carbon monoxide will oxidize to carbon dioxide. But the pure carbon will have a very serious going on. By the incomplete combustion of not only propane, but other hydrocarbons, will be produced and the pure carbon also. This "pure carbon" or "black carbon" plays a

  18. Carbon Stock and Carbon Cycle of Wetland Ecosystem

    OpenAIRE

    Zeng, Zhangquan; Zhang, Canming; LI, JIAO; Yang, Nan; Li, Xiquan; Niu, Yandong; Wu, Zijian

    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 relationshi...

  19. Carbonate hosted gold deposit in Tasmania, Australia

    International Nuclear Information System (INIS)

    Full text: This study uses elemental and isotopic composition of carbonates associated with gold from Henty and Beaconsfield in Tasmania, Australia, to illustrate source of gold-bearing fluids, salinity, temperature and dissolution and reprecipitation of carbonate. The Beaconsfield and Henty gold mines are located in northern and western Tasmania respectively. Gold mineralisation in Beaconsfield occurs within the quartz-carbonate Tasmania Reef (Lower to Middle Palaeozoic sequence, Hills, 1998). The Henty gold mine is located at the base of the Cambrian Tyndall Group (volcano-sedimentary succession, White and McPhie, 1996) close to Henty Fault. Gold in carbonate samples from Henty ranges from 7.7 to 9360 ppm and in Beaconsfield ranges from 0.01 to 434 ppm. The amount of carbonate in samples from Henty and Beaconsfield gold mines varies from approximately 24 to 99.8%. Bivariate plot of Ca relative to total amounts of Mg, Fe and Mn illustrates that the major carbonate minerals at Beaconsfield and Henty gold mines are magnesian ankerite and calcite. The difference in carbonate mineralogy, at Henty and Beaconsfield gold mines, is attributed to the composition of fluids responsible for carbonate alteration. Gold and magnesium in Beaconsfield ankerite are derived from the leaching of Cambrian ultramafic rocks during the Devonian by the passage of meteoric fluids through tectonically affected Ordovician carbonates (Rao and Adabi, 1999). The total concentration of Fe and Mn are low (0.5 to 2%) in Henty and high (1 to 17.5%) in Beaconsfield ankerite, possibly due to oxidising conditions at Henty and reducing conditions at Beaconsfield gold mines during gold mineralisation. Variation of Sr values between Beaconsfield ankerite and Henty calcite is related to dissolution of limestone that increase Sr concentrations in gold mineralising fluids. Na values in both Beaconsfield (20 to 1100 ppm) and Henty carbonates (25 to 1650 ppm) suggest low salinity fluids responsible for gold

  20. 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 ...

  1. 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 ...

  2. 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

  3. 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

  4. Seeing the Carbon Cycle

    Science.gov (United States)

    Drouin, Pamela; Welty, David J.; Repeta, Daniel; Engle-Belknap, Cheryl A.; Cramer, Catherine; Frashure, Kim; Chen, Robert

    2006-01-01

    In this article, the authors present a classroom experiment that was developed to introduce middle school learners to the carbon cycle. The experiment deals with transfer of CO[subscript 2] between liquid reservoirs and the effect CO[subscript 2] has on algae growth. It allows students to observe the influence of the carbon cycle on algae growth,…

  5. The carbon cycle revisited

    Science.gov (United States)

    Bolin, Bert; Fung, Inez

    1992-01-01

    Discussions during the Global Change Institute indicated a need to present, in some detail and as accurately as possible, our present knowledge about the carbon cycle, the uncertainties in this knowledge, and the reasons for these uncertainties. We discuss basic issues of internal consistency within the carbon cycle, and end by summarizing the key unknowns.

  6. 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...

  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 Monoxide Poisoning

    Science.gov (United States)

    ... natural gas, propane, oil, and methane) burn incompletely. ** Carbon Monoxide can have different effects on people based on its concentration in the air that people breathe, and the person’s health condition.**** Each year, carbon monoxide poisoning claims approximately 480 lives and sends another ...

  9. 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...

  10. 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.)…

  11. 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,

  12. 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

  13. 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).

  14. Climate change, fire and the carbon balance

    International Nuclear Information System (INIS)

    On average, forest fires have burned 2 to 3 million hectares annually in Canada over the last twenty years. Over the last 40 years, this amounts to 20 per cent of the amount of carbon released through fossil fuel emissions in Canada. This paper analyses the extent to which climate change may contribute to a disturbance in the carbon balance due to increased fire activity. In addition, data from FLUXNET-Canada was examined, indicating that carbon fluxes from younger forests show dramatic changes in diurnal carbon flux patterns, caused by reduced photosynthetic uptake during the day and less root respiration at night. Increases in fire are expected throughout much of the boreal forest towards the end of this century, with a lengthening of the fire season and increases in severity and intensity. It was concluded that there is the possibility of a positive feedback, where climate change could cause more fires, resulting in a greater release of carbon and thereby increasing greenhouse gas concentrations. Evidence that smoke promoted positive lightning strikes while reducing precipitation was also presented. It was suggested that certain self-limiting factors may prevent a run-away scenario. Changes to human and lightning ignition patterns, for example, may have an impact. It was also suggested that research efforts should focus on refining climate change estimates that account for landscape change and other aspects that control fire in Canada. 9 refs., 2 figs

  15. Nanosponge formation from organocatalytically-synthesized poly(carbonate) copoplymers

    OpenAIRE

    Stevens, David M.; Tempelaar, Sarah; Dove, Andrew P.; Harth, Eva

    2012-01-01

    Advanced organocatalytic synthesis methods were employed to prepare linear poly(carbonate)s with control over functional group incorporation and molecular weight. Pendant allyl or epoxide groups served as reaction partners in thiol-ene click or epoxide–amine reactions with ethylene oxide-containing crosslinking groups to form a panel of six novel poly(carbonate) nanosponges with crosslinking densities ranging from 5%, 10% and 20% via an intermolecular chain-crosslinking approach.

  16. Specific Energy Characteristics of Nanoporous Carbon Activated by Orthophosphoric Acid

    Directory of Open Access Journals (Sweden)

    B.I. Rachiy

    2015-12-01

    Full Text Available This paper investigated the effect of the amount of phosphoric acid on the structure nanoporous carbon materials (NCM obtained from raw materials of plant origin. The results voltammetry defined specific capacitance characteristics of NCM and conditions its synthesis with optimal energy parameters established. It is shown that reducing the number of lignin-cellulose materials in precursor volume due to carbonization leads to a decline in specific capacity of NCM approximately 6-20 %.

  17. Epidemiological bases for the current ambient carbon monoxide standards.

    OpenAIRE

    Kuller, L H; Radford, E P

    1983-01-01

    Carbon monoxide is widely distributed in the environment, and acute or chronic toxic effects may be of considerable public health significance. A review of the basis for current ambient standards is given. Mortality and morbidity studies have been negative or equivocal in relating carbon monoxide levels to health effects, but studies in human subjects with compromised coronary or peripheral circulation support an effect of acute exposure to CO at blood levels equivalent to about 20 ppm over s...

  18. The Users Office turns 20

    CERN Multimedia

    2009-01-01

    20 years ago, in the summer of 1989, an office was created to assist the thousands of users who come to CERN each year, working over the broad range of projects and collaborations. Chris Onions (right), head of the Users’ Office, with Bryan Pattison (left), the Office’s founder.Before the inception of the Users Office, it was common for users to spend at least an entire day moving from office to office in search of necessary documentation and information in order to make their stay official. "Though the Office has undergone various changes throughout its lifetime, it has persisted in being a welcoming bridge to facilitate the installation of visitors coming from all over the world", says Chris Onions, head of the Users Office. This September, the Office will celebrate its 20-year anniversary with a drink offered to representatives of the User community, the CERN management and staff members from the services with whom the Office is involved. &...

  19. The influence of bubbles on the perception carbonation bite.

    Directory of Open Access Journals (Sweden)

    Paul M Wise

    Full Text Available Although many people naively assume that the bite of carbonation is due to tactile stimulation of the oral cavity by bubbles, it has become increasingly clear that carbonation bite comes mainly from formation of carbonic acid in the oral mucosa. In Experiment 1, we asked whether bubbles were in fact required to perceive carbonation bite. Subjects rated oral pungency from several concentrations of carbonated water both at normal atmospheric pressure (at which bubbles could form and at 2.0 atmospheres pressure (at which bubbles did not form. Ratings of carbonation bite under the two pressure conditions were essentially identical, indicating that bubbles are not required for pungency. In Experiment 2, we created controlled streams of air bubbles around the tongue in mildly pungent CO2 solutions to determine how tactile stimulation from bubbles affects carbonation bite. Since innocuous sensations like light touch and cooling often suppress pain, we predicted that bubbles might reduce rated bite. Contrary to prediction, air bubbles flowing around the tongue significantly enhanced rated bite, without inducing perceived bite in blank (un-carbonated solutions. Accordingly, though bubbles are clearly not required for carbonation bite, they may well modulate perceived bite. More generally, the results show that innocuous tactile stimulation can enhance chemogenic pain. Possible physiological mechanisms are discussed.

  20. THE Eucalyptus sp. AGE PLANTATIONS INFLUENCING THE CARBON STOCKS

    Directory of Open Access Journals (Sweden)

    Charlote Wink

    2013-06-01

    Full Text Available http://dx.doi.org/10.5902/198050989279The tree growth and biomass accumulation, as well as the maintenance of forest residue at the soil surface can act in the removal of carbon from the atmosphere through the cycling process of plant material. The objective was to study the influence of Eucalyptus sp. Plantations with 20, 44 and 240 months of age on the variation of carbon in soil and biomass. The carbon in the soil depth was determined by CHNS auto-analyzer and carbon in the vegetation was determined by the biomass in each forest, considering a factor of 0.45 of the dry mass. We determined the density and particle size distribution of soil. For the comparison between plantations, there was analysis of variance and comparison of means of carbon in vegetation and soil, considering the 5% level of probability. The carbon content and stock in the soil were low, indicating that a natural feature of the category of Paleuldt, or the growth of eucalyptus forests, replacing the field native vegetation did not aggregate a significant increase in the carbon. Although, there was a significant increase carbon in aboveground biomass. It includes forest biomass and litter. So, despite the values ​​of carbon stocks are low, it identified a greater average total in the soil compared to the stock aboveground. Furthermore, this increase aboveground (tree and litter compartments can be considered significant between the eucalyptus plantations of different ages.

  1. Roles of Mineralogical Phases in Aqueous Carbonation of Steelmaking Slag

    Directory of Open Access Journals (Sweden)

    Huining Zhang

    2016-05-01

    Full Text Available Mineralogical phases of steelmaking slags have significant influences on the carbonation of the slags. In this paper, the effects of temperature and reaction time on the conversion of calcium-related phases and the carbonation degree of a slag sample were studied. The experimental conditions were a liquid-to-solid ratio of 20 mL/g, a carbon dioxide flow rate of 1 L/min and a slag particle size of 38–75 μm. The results show that the optimum carbonation temperature and reaction time are 60 °C and 90 min, respectively, and calcite phase content is about 26.78% while the conversion rates of Ca3Al2O6, CaSiO3, Ca2SiO4 and free CaO are about 40%, 42.46%, 51% and 100%, respectively, and the carbon dioxide sequestration efficiency is about 170 g/kg slag.

  2. Type Ia Supernova Carbon Footprints

    CERN Document Server

    Thomas, R C; Aragon, C; Antilogus, P; Bailey, S; Baltay, C; Bongard, S; Buton, C; Canto, A; Childress, M; Chotard, N; Copin, Y; Fakhouri, H K; Gangler, E; Hsiao, E Y; Kerschhaggl, M; Kowalski, M; Loken, S; Nugent, P; Paech, K; Pain, R; Pecontal, E; Pereira, R; Perlmutter, S; Rabinowitz, D; Rigault, M; Rubin, D; Runge, K; Scalzo, R; Smadja, G; Tao, C; Weaver, B A; Wu, C; Brown, P J; Milne, P A

    2011-01-01

    We present convincing evidence of unburned carbon at photospheric velocities in new observations of 5 Type Ia supernovae (SNe Ia) obtained by the Nearby Supernova Factory. These SNe are identified by examining 346 spectra from 124 SNe obtained before +2.5 d relative to maximum. Detections are based on the presence of relatively strong C II 6580 absorption "notches" in multiple spectra of each SN, aided by automated fitting with the SYNAPPS code. Four of the 5 SNe in question are otherwise spectroscopically unremarkable, with ions and ejection velocities typical of SNe Ia, but spectra of the fifth exhibits high-velocity (v > 20,000 km/s) Si II and Ca II features. On the other hand, the light curve properties are preferentially grouped, strongly suggesting a connection between carbon-positivity and broad band light curve/color behavior: Three of the 5 have relatively narrow light curves but also blue colors, and a fourth may be a dust-reddened member of this family. Accounting for signal-to-noise and phase, we ...

  3. Analysis of Terrestrial Carbon Stocks in a Small Catchment of Northeastern Siberia

    Science.gov (United States)

    Heard, K.; Natali, S.; Bunn, A. G.; Loranty, M. M.; Kholodov, A. L.; Schade, J. D.; Berner, L. T.; Spektor, V.; Zimov, N.; Alexander, H. D.

    2015-12-01

    As arctic terrestrial ecosystems comprise about one-third of the global terrestrial ecosystem carbon total, understanding arctic carbon cycling and the feedback of terrestrial carbon pools to accelerated warming is an issue of global concern. For this research, we examined above- and belowground carbon stocks in a larch-dominated catchment underlain by yedoma and located within the Kolyma River watershed in northeastern Siberia. We quantified carbon stocks in vegetation, active layer, and permafrost, and we assessed the correlation between plant and active layer carbon pools and four environmental correlates — slope, solar insolation, canopy density, and leaf area index ­— at 20 sites. Carbon in the active layer was approximately four times greater than aboveground carbon pools (972 g C m-2), and belowground carbon to 1 m depth was approximately 18 times greater than aboveground carbon pools. Canopy density and slope had a robust positive association with aboveground carbon pools, and soil moisture was positively related to %C in organic, thawed mineral and permafrost soil. Thaw depth was negatively correlated with moss cover and larch biomass, highlighting the importance of vegetation and surface characteristics on permafrost carbon vulnerability. These data suggest that landscape and ecosystem characteristics affect carbon accumulation and storage, but they also play an important role in stabilizing permafrost carbon pools.

  4. Composite electrodes of activated carbon derived from cassava peel and carbon nanotubes for supercapacitor applications

    Science.gov (United States)

    Taer, E.; Iwantono, Yulita, M.; Taslim, R.; Subagio, A.; Salomo, Deraman, M.

    2013-09-01

    In this paper, a composite electrode was prepared from a mixture of activated carbon derived from precarbonization of cassava peel (CP) and carbon nanotubes (CNTs). The activated carbon was produced by pyrolysis process using ZnCl2 as an activation agent. A N2 adsorption-desorption analysis for the sample indicated that the BET surface area of the activated carbon was 1336 m2 g-1. Difference percentage of CNTs of 0, 5, 10, 15 and 20% with 5% of PVDF binder were added into CP based activated carbon in order to fabricate the composite electrodes. The morphology and structure of the composite electrodes were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The SEM image observed that the distribution of CNTs was homogeneous between carbon particles and the XRD pattern shown the amorphous structure of the sample. The electrodes were fabricated for supercapacitor cells with 316L stainless steel as current collector and 1 M sulfuric acid as electrolyte. An electrochemical characterization was performed by using an electrochemical impedance spectroscopy (EIS) method using a Solatron 1286 instrument and the addition of CNTs revealed to improve the resistant and capacitive properties of supercapacitor cell.

  5. Carbon deposition with LOX/RP-1 propellants

    Science.gov (United States)

    Lausten, M. F.; Rousar, D. C.; Buccella, S.

    1985-01-01

    The generation and deposition of carbon were studied using subscale hardware with LOX/RP-1 propellants. Deposition on a turbine simulator at preburner or gas generator conditions was evaluated at mixture ratios of 0.25 to 1.0 and chamber pressures of 750 to 1500 psia. Deposition on the combustion chamber wall was investigated at mixture ratios of 2.0 to 4.0 and chamber pressures of 1000 to 1500 psia. Significant carbon buildup was observed on the turbine simulator at low mixture ratios but no carbon deposition on the chamber walls was detected at the higher mixture ratios.

  6. Carbon Nanotube Electron Emitter for X-ray Imaging

    Directory of Open Access Journals (Sweden)

    Jung Su Kang

    2012-11-01

    Full Text Available The carbon nanotube field emitter array was grown on silicon substrate through a resist-assisted patterning (RAP process. The shape of the carbon nanotube array is elliptical with 2.0 × 0.5 mm2 for an isotropic focal spot size at anode target. The field emission properties with triode electrodes show a gate turn-on field of 3 V/µm at an anode emission current of 0.1 mA. The author demonstrated the X-ray source with triode electrode structure utilizing the carbon nanotube emitter, and the transmitted X-ray image was of high resolution.

  7. Carbon Nanotube Electron Emitter for X-ray Imaging

    OpenAIRE

    Jung Su Kang; Je Hwang Ryu; Kyu Chang Park

    2012-01-01

    The carbon nanotube field emitter array was grown on silicon substrate through a resist-assisted patterning (RAP) process. The shape of the carbon nanotube array is elliptical with 2.0 × 0.5 mm2 for an isotropic focal spot size at anode target. The field emission properties with triode electrodes show a gate turn-on field of 3 V/µm at an anode emission current of 0.1 mA. The author demonstrated the X-ray source with triode electrode structure utilizing the carbon nanotube em...

  8. Biological control of the terrestrial carbon sink

    Directory of Open Access Journals (Sweden)

    E.-D. Schulze

    2006-01-01

    Full Text Available This lecture reviews the past (since 1964 when the International Biological Program began and the future of our understanding of terrestrial carbon fluxes with focus on photosynthesis, respiration, primary-, ecosystem-, and biome-productivity. Photosynthetic capacity is related to the nitrogen concentration of leaves, but the capacity is only rarely reached under field conditions. Average rates of photosynthesis and stomatal conductance are closely correlated and operate near 50% of their maximal rate, with light being the limiting factor in humid regions and air humidity and soil water the limiting factor in arid climates. Leaf area is the main factor to extrapolate from leaves to canopies, with maximum surface conductance being dependent on leaf level stomatal conductance. Additionally, gas exchange depends also on rooting depth which determines the water and nutrient availability and on mycorrhizae which regulate the nutrient status. An important anthropogenic disturbance is the nitrogen uptake from air pollutants, which is not balanced by cation uptake from roots and this may lead to damage and breakdown of the plant cover. Photosynthesis is the main carbon input into ecosystems, but it alone does not represent the ecosystem carbon balance, which is determined by respiration of various kinds. Plant respiration and photosynthesis determine growth (net primary production and microbial respiration balances the net ecosystem flux. In a spruce forest, 30% of the assimilatory carbon gain is used for respiration of needles, 20% is used for respiration in stems. Soil respiration is about 50% the carbon gain, half of which is root respiration, half is microbial respiration. In addition, disturbances lead to carbon losses, where fire, harvest and grazing bypass the chain of respiration. In total, the carbon balance at the biome level is only about 1% of the photosynthetic carbon input, or may indeed become negative. The recent observed increase in

  9. Natural disturbance impacts on Canada's forest carbon budget

    International Nuclear Information System (INIS)

    Wildfire and insect outbreaks are major determinants of forest dynamics in Canada, transferring carbon within the ecosystem, releasing carbon into the atmosphere and influencing post-disturbance carbon dynamics. This paper discusses the impacts of global climate change on natural disturbances. Higher temperatures and drier conditions are likely to increase burned areas in Canada and will also increase the impacts of insects, allowing for an expanded range and stressing their host species. Long-term changes in disturbance regimes have already affected Canada's forest age-class structure. Statistics of lower disturbance periods and carbon production were compared with periods of higher disturbance. Scenario analyses were conducted for the period of 1996 to 2032, assuming that annual insect and fire disturbance rates in timber-productive forests were 20 per cent higher and carbon production 20 per cent lower than base scenarios using average disturbance rates. It was concluded that these conditions could cause carbon stocks in Canada's forests to decline. The future carbon balance of Canada's forests will be affected by the rate of natural and human-induced disturbances. 4 refs

  10. Climate Constraints on the Carbon Intensity of Economic Growth

    Science.gov (United States)

    Davis, S. J.; Rozenberg, J.; Hallegatte, S.; Narloch, U.

    2015-12-01

    Development and climate goals together constrain the carbon intensity of production. Using a simple and transparent model that represents committed CO2 emissions (i.e. those embedded in installed capital), we explore the carbon intensity of production related to new capital required for different temperature targets across several thousand scenarios. Future pathways consistent with the 2oC target which allow for continued GDP growth require early action to reduce carbon intensity of new production, and either (i) a short lifetime of energy and industry capital (e.g. early retrofit of coal power plants), or (ii) large negative emissions after 2050 (i.e. rapid development and dissemination of carbon capture and sequestration). To achieve the 2oC target, half of the scenarios indicate a carbon intensity of new production between 33 and 73 g CO2/ - much lower than the carbon intensities of the best performing countries today. The average lifespan of energy capital (especially power plants), and industry capital, are critical because they commit emissions far into the future and reduce the budget for new capital emissions. Each year of lifetime added to existing, carbon intensive capital, decreases the carbon intensity of new production required to meet a 2°C carbon budget by 1 to 1.5 g CO2/, and each year of delaying the start of mitigation decreases the required CO2 intensity of new production by 20 to 50 gCO2/$. Constraints on the carbon intensity of new production under a 3°C target are considerably relaxed relative to the 2°C target, but remain daunting in comparison to the carbon intensity of the global economy today. Figure Caption: The relationship between GDP per capita growth, lifetime of energy and industry capital and the required carbon intensity of new production 2013-2050 under a 2°C target.

  11. HYDROGEN SULFIDE ADSORPTION BY ALKALINE IMPREGNATED COCONUT SHELL ACTIVATED CARBON

    Directory of Open Access Journals (Sweden)

    HUI SUN CHOO

    2013-12-01

    Full Text Available Biogas is one type of renewable energy which can be burnt to produce heat and electricity. However, it cannot be burnt directly due to the presence of hydrogen sulfide (H2S which is highly corrosive to gas engine. In this study, coconut shell activated carbon (CSAC was applied as a porous adsorbent for H2S removal. The effect of amount of activated carbon and flow rate of gas stream toward adsorption capacity were investigated. Then, the activated carbons were impregnated by three types of alkaline (NaOH, KOH and K2CO3 with various ratios. The effects of various types of alkaline and their impregnation ratio towards adsorption capacity were analysed. In addition, H2S influent concentration and the reaction temperature on H2S adsorption were also investigated. The result indicated that adsorption capacity increases with the amount of activated carbon and decreases with flow rate of gas stream. Alkaline impregnated activated carbons had better performance than unimpregnated activated carbon. Among all impregnated activated carbons, activated carbon impregnated by K2CO3 with ratio 2.0 gave the highest adsorption capacity. Its adsorption capacity was 25 times higher than unimpregnated activated carbon. The result also indicated that the adsorption capacity of impregnated activated carbon decreased with the increment of H2S influent concentration. Optimum temperature for H2S adsorption was found to be 50˚C. In this study, the adsorption of H2S on K2CO3 impregnated activated carbon was fitted to the Langmuir isotherm. The fresh and spent K2CO3 impregnated activated carbon were characterized to study the adsorption process.

  12. Preparation and characterization of activated carbon produced from pomegranate seeds by ZnCl 2 activation

    Science.gov (United States)

    Uçar, Suat; Erdem, Murat; Tay, Turgay; Karagöz, Selhan

    2009-08-01

    In this study, pomegranate seeds, a by-product of fruit juice industry, were used as precursor for the preparation of activated carbon by chemical activation with ZnCl 2. The influence of process variables such as the carbonization temperature and the impregnation ratio on textural and chemical-surface properties of the activated carbons was studied. When using the 2.0 impregnation ratio at the carbonization temperature of 600 °C, the specific surface area of the resultant carbon is as high as 978.8 m 2 g -1. The results showed that the surface area and total pore volume of the activated carbons at the lowest impregnation ratio and the carbonization temperature were achieved as high as 709.4 m 2 g -1 and 0.329 cm 3 g -1. The surface area was strongly influenced by the impregnation ratio of activation reagent and the subsequent carbonization temperature.

  13. The formation of carbon nanostructures by in situ TEM mechanical nanoscale fatigue and fracture of carbon thin films

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J J; Lockwood, A J; Peng, Y; Xu, X; Inkson, B J [Department of Engineering Materials, University of Sheffield, Sheffield S1 3JD (United Kingdom); Bobji, M S, E-mail: beverley.inkson@sheffield.ac.u [Department of Mechanical Engineering, Indian Institute of Science, Bangalore 560012, Karnataka (India)

    2009-07-29

    A technique to quantify in real time the microstructural changes occurring during mechanical nanoscale fatigue of ultrathin surface coatings has been developed. Cyclic nanoscale loading, with amplitudes less than 100 nm, is achieved with a mechanical probe miniaturized to fit inside a transmission electron microscope (TEM). The TEM tribological probe can be used for nanofriction and nanofatigue testing, with 3D control of the loading direction and simultaneous TEM imaging of the nano-objects. It is demonstrated that fracture of 10-20 nm thick amorphous carbon films on sharp gold asperities, by a single nanoscale shear impact, results in the formation of <10 nm diameter amorphous carbon filaments. Failure of the same carbon films after cyclic nanofatigue, however, results in the formation of carbon nanostructures with a significant degree of graphitic ordering, including a carbon onion.

  14. The paper of the forests like retainers of carbon, an experience in the south of Mexico

    International Nuclear Information System (INIS)

    The forests play an important paper in the global cycle of the carbon. At the moment, the deforestation is responsible for approximately 1.8GtC (gigatons of carbon), 20% of the global annual emissions of carbonic gas caused by the human activity. However, it is calculated that the reforestation could retain from 50 to 150 GtC along next 50 years. Concepts related with the retention of carbon are discussed. The necessity is commented of carrying out the regulation of an international market in retention of carbon with the purpose of being able to maintain acceptable norms in the reforestation projects that are executed under this program

  15. 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.

  16. 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.

  17. Big Sky Carbon Sequestration Partnership

    Energy Technology Data Exchange (ETDEWEB)

    Susan Capalbo

    2005-12-31

    has significant potential to sequester large amounts of CO{sub 2}. Simulations conducted to evaluate mineral trapping potential of mafic volcanic rock formations located in the Idaho province suggest that supercritical CO{sub 2} is converted to solid carbonate mineral within a few hundred years and permanently entombs the carbon. Although MMV for this rock type may be challenging, a carefully chosen combination of geophysical and geochemical techniques should allow assessment of the fate of CO{sub 2} in deep basalt hosted aquifers. Terrestrial carbon sequestration relies on land management practices and technologies to remove atmospheric CO{sub 2} where it is stored in trees, plants, and soil. This indirect sequestration can be implemented today and is on the front line of voluntary, market-based approaches to reduce CO{sub 2} emissions. Initial estimates of terrestrial sinks indicate a vast potential for increasing and maintaining soil Carbon (C) on rangelands, and forested, agricultural, and reclaimed lands. Rangelands can store up to an additional 0.05 mt C/ha/yr, while the croplands are on average four times that amount. Estimates of technical potential for soil sequestration within the region in cropland are in the range of 2.0 M mt C/yr over 20 year time horizon. This is equivalent to approximately 7.0 M mt CO{sub 2}e/yr. The forestry sinks are well documented, and the potential in the Big Sky region ranges from 9-15 M mt CO{sub 2} equivalent per year. Value-added benefits include enhanced yields, reduced erosion, and increased wildlife habitat. Thus the terrestrial sinks provide a viable, environmentally beneficial, and relatively low cost sink that is available to sequester C in the current time frame. The Partnership recognizes the critical importance of measurement, monitoring, and verification technologies to support not only carbon trading but all policies and programs that DOE and other agencies may want to pursue in support of GHG mitigation. The efforts

  18. Carbon isotope techniques

    International Nuclear Information System (INIS)

    This book is a hands-on introduction to using carbon isotope tracers in experimental biology and ecology. It is a bench-top reference with protocols for the study of plants, animals, and soils. The 11C, 12C, 13C, and 14C carbon isotopes are considered and standard techniques are described by established authors. The compilation includes the following features: specific, well-established, user-oriented techniques; carbon cycles in plants, animals, soils, air, and water; isotopes in ecological research; examples and sample calculations

  19. Ez 20 i moralne implikacije

    OpenAIRE

    Višaticki, Karlo

    2012-01-01

    U uvodnom dijelu priloga daje se kratka biografija proroka Ezekiela. Podatci su vrlo oskudni, tako da se teško može govoriti o pravoj biografiji, više zapravo o obrisima i minimalnim podatcima. Prorok Ezekiel pozvan je od Gospodina u vrijeme babilonskog sužanjstva. Govoreći o samom spisu, donose se prijedlozi podjele teksta Ezekielove knjige s tim što treba reći da glede toga ne postoji konsenzus među autorima. Tekst Ez 20, koji se u daljnjem dijelu rada analizira, ima simptomatičan naslov – ...

  20. Genome Sequence of the Haloalkaliphilic Methanotrophic Bacterium Methylomicrobium alcaliphilum 20Z

    OpenAIRE

    Vuilleumier, Stéphane; Khmelenina, Valentina N; Bringel, Françoise; Reshetnikov, Alexandr S.; Lajus, Aurélie; Mangenot, Sophie; Rouy, Zoé; Op Den Camp, Huub J M; Jetten, Mike S. M.; DiSpirito, Alan A.; Dunfield, Peter; Klotz, Martin G.; Semrau, Jeremy D.; Stein, Lisa Y.; Barbe, Valérie

    2012-01-01

    Methylomicrobium strains are widespread in saline environments. Here, we report the complete genome sequence of Methylomicrobium alcaliphilum 20Z, a haloalkaliphilic methanotrophic bacterium, which will provide the basis for detailed characterization of the core pathways of both single-carbon metabolism and responses to osmotic and high-pH stresses. Final assembly of the genome sequence revealed that this bacterium contains a 128-kb plasmid, making M. alcaliphilum 20Z the first methanotrophic...

  1. Iron-Doped Carbon Aerogels: Novel Porous Substrates for Direct Growth of Carbon Nanotubes

    Science.gov (United States)

    Steiner, S. A.; Baumann, T. F.; Kong, J.; Satcher, J. H.; Dresselhaus, M. S.

    2007-02-20

    We present the synthesis and characterization of Fe-doped carbon aerogels (CAs) and demonstrate the ability to grow carbon nanotubes directly on monoliths of these materials to afford novel carbon aerogel-carbon nanotube composites. Preparation of the Fe-doped CAs begins with the sol-gel polymerization of the potassium salt of 2,4-dihydroxybenzoic acid with formaldehyde, affording K{sup +}-doped gels that can then be converted to Fe{sup 2+}- or Fe{sup 3+}-doped gels through an ion exchange process, dried with supercritical CO{sub 2} and subsequently carbonized under an inert atmosphere. Analysis of the Fe-doped CAs by TEM, XRD and XPS revealed that the doped iron species are reduced during carbonization to form metallic iron and iron carbide nanoparticles. The sizes and chemical composition of the reduced Fe species were related to pyrolysis temperature as well as the type of iron salt used in the ion exchange process. Raman spectroscopy and XRD analysis further reveal that, despite the presence of the Fe species, the CA framework is not significantly graphitized during pyrolysis. The Fe-doped CAs were subsequently placed in a thermal CVD reactor and exposed to a mixture of CH{sub 4} (1000 sccm), H{sub 2} (500 sccm), and C{sub 2}H{sub 4} (20 sccm) at temperatures ranging from 600 to 800 C for 10 minutes, resulting in direct growth of carbon nanotubes on the aerogel monoliths. Carbon nanotubes grown by this method appear to be multiwalled ({approx}25 nm in diameter and up to 4 mm long) and grow through a tip-growth mechanism that pushes catalytic iron particles out of the aerogel framework. The highest yield of CNTs were grown on Fe-doped CAs pyrolyzed at 800 C treated at CVD temperatures of 700 C.

  2. Carbonate-containing apatite (CAP) synthesis under moderate conditions starting from calcium carbonate and orthophosphoric acid

    International Nuclear Information System (INIS)

    The synthesis of carbonate-containing apatite (CAP) from calcium carbonate and orthophosphoric acid under moderate conditions was investigated. In all cases, complete precipitation of orthophosphate species was observed. The reaction temperature influenced strongly the decomposition of calcium carbonate and therefore the composition of formed products. The reaction temperature of 80 °C was found to be effective for the complete decomposition of calcium carbonate particles after 48 h of reaction. Infra-red spectroscopy (IR), nuclear magnetic resonance (NMR), thermogravimetry/mass spectroscopy (TG–MS) coupling, and X-ray diffraction (XRD) characterizations allowed the identification of the composition of formed products. By increasing the reaction temperature from 20 °C to 80 °C, the content of A-type CAP increased and that of B-type CAP decreased, according to the favorable effect of temperature on the formation of A-type CAP. The total amount of carbonate content incorporated in CAP's structure, which was determined by TG–MS analysis, increased with the reaction temperature and reached up to 4.1% at 80 °C. At this temperature, the solid product was mainly composed of apatitic components and showed the typical flat-needle-like structure of CAP particles obtained in hydrothermal conditions. These results show an interesting one-step synthesis of CAP from calcium carbonate and orthophosphoric acid as low cost but high purity starting materials. Highlights: • The synthesis of carbonate-containing apatites from CaCO3 and H3PO4 was studied. • The decomposition of CaCO3 particles was complete at 80 °C, 13.2 bar for 48 h. • The transformation of CaCO3 and H3PO4 into apatitic products was also complete. • Pure carbonate-containing apatite was directly obtained without water-rising step

  3. Evaluation of Powdered Activated Carbon Efficiency in Removal of Dissolved Organic Carbon inWater Treatment

    Directory of Open Access Journals (Sweden)

    G.R Bonyadi nejad

    2010-07-01

    Full Text Available "n "nBackgrounds and Objectives: Powdered Activated$ carbon is known as a suitable absorbent for organic materials. The aim of this research is evaluation of Powdered Activated-Carbon (PAC efficiency in removal of Dissolved Organic Carbon (DOC in water treatment in Isfahan."nMaterials and Methods : The increase of PAC for DOC reduction has done in three paths in the Isfahan water treatment plant (WTP. These paths including: 1 Intake up to entrance of WTP 2 Intake to exit ofWTP 3 Between entrance and exit of waterworks. The paths were simulated by the Jar test system. Then DOC and UV254 absorption were analyzed and SUVA parameter for samples and activated-carbon adsorption isotherm was calculated."nResults: The injected PAC doses of 20,40,60,80 and 100 mg/l caused decreasing in DOC and UV254 absorption in every sample in all paths. The average of this decrease, from intake to WTP.s exit (second path was the greatest 69.8± 3.9%and the commonWTP process had capability of removing 35% of DOC. The first path also showed that PAC can reduce 33± 2% DOC of raw water by itself. Activated-carbon absorption results were adhered from Freundlich adsorption isotherm."nConclusion: In the third path therewas lessDOCremoval efficiency than exceptedwhen Activated- Carbon injected in rapid mixed basin with coagulant. Powdered activated carbon porosity reduction due to effect of coagulant can be the reason for this issue.Also according to different paths, the point of intake is more suitable for powdered activated carbon addition.

  4. A novel carbon fiber based porous carbon monolith

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-07-01

    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.

  5. 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...

  6. 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.

  7. 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).

  8. Carbon and Oxygen Isotopic Composition of Surface-Sediment Carbonate in Bosten Lake (Xinjiang, China) and its Controlling Factors

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chengjun; Steffen MISCHKE; ZHENG Mianping; Alexander PROKOPENKO; GUO Fangqin; FENG Zhaodong

    2009-01-01

    Bosten Lake is a mid-latitude lake with water mainly supplied by melting ice and snow in the Tianshan Mountains. The depositional environment of the lake is spatially not uniform due to the proximity of the major inlet and the single outlet in the western part of the lake. The analytical results show that the carbon and oxygen isotopic composition of recent lake sediments is related to this specific lacustrine depositional environment and to the resulting carbonate mineralogy. In the southwestern lake region between the Kaidu River inlet and the Kongqi River outlet, carbon isotope composition (δ13C) values of the carbonate sediment (-1‰ to -2‰) have no relation to the oxygen isotope composition of the carbonate (δ18O) values (-7‰ to -8‰), with both isotopes showing a low variability. The carbonate content is low (<20%). Carbonate minerals analyzed by X-ray diffraction are mainly composed of calcite, while aragonite was not recorded. The salinity of the lake water is low in the estuary region as a result of the Kaidu River inflow. In comparison, the carbon and oxygen isotope values are higher in the middle and eastern parts of the lake, with δ13C values between approximately +0.5‰ and +3‰, and δ18O values between -1‰ and -5‰. There is a moderate correlation between the stable oxygen and carbon isotopes, with a coefficient of correlation r of approximately 0.63. This implies that the lake water has a relatively short residence time. Carbonate minerals constitute calcite and aragonite in the middle and eastern region of the lake. Aragonite and Mg-calcite are formed at higher lake water salinity and temperatures, and larger evaporation effects. More saline lake water in the middle and eastern region of the lake and the enhanced isotopic equilibrium between water and atmospheric CO2 cause the correlating carbon and oxygen isotope values determined for aragonite and Mg-calcite. Evaporation and biological processes are the main reasons for the salinity

  9. Draw out Carbon Nanotube from Liquid Carbon

    OpenAIRE

    ZHANG, SHUANG; Hoshi, Takeo; Fujiwara, Takeo

    2006-01-01

    Carbon nanotube (CNT) is expected for much more important and broader applications in the future, because of its amazing electrical and mechanical properties. However, today, the prospect is detained by the fact that the growth of CNTs cannot be well controlled. In particular, controlling the chirality of CNTs seems formidable to any existing growth method. In addition, a systematic method for a designed interconnected network has not been established yet, which is focused particularly in nan...

  10. 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.)

  11. Difference Analysis of Different Land Use Types on Soil Organic Carbon in Loess Gullied-Hilly Region of China

    Directory of Open Access Journals (Sweden)

    Jianing Zhang

    2015-02-01

    Full Text Available The cycles of carbon in terrestrial ecosystems has received increasing attention worldwide. Because the balance between inputs and outputs of carbon to the soil has an important influences on the atmospheric CO2 and global climate. With the increasing deforestation and overgrazing, the impact of human disturbances on carbon storage and fluxes have exceeded the rate and extent of effects from natural variability, this could significantly raise the CO2 concentration in the atmosphere. Thus, accurate estimations of land use and land cover in soil ecosystem have become increasingly important for estimating the carbon balance of regions. One of the greatest uncertainties concerning the influence of human activities is changes in soil carbon stock. In this study, soil samples were collected form farmland, orchard, woodland, grassland, wasteland five different land use types. Each soil sample core was separated into 0-10, 10-20, 20-40 and 40-60 cm depth. The study revealed the difference of soil carbon pool storage and mass effect in different land use styles by the contrast analysis of total organic carbon, labile organic carbon and carbon management index in number, distribution and changes. The results showed that there were big differences for the density of Total Organic Carbon (TOC among different land use types, which means soil organic carbon storages were different. The extent of variation of the mass fraction of TOC and LOC was increase with the increase of soil depth and 0-20 cm layer was significantly greater than 20-60 cm layer. Relative to wasteland, the density of LOC and NLOC, total organic carbon storage and carbon management index for other four land use types were higher, especial for woodland and grassland. The woodland use type and grassland use type were significantly increased the carbon management index and improved the quality of soil carbon pool. The change of soil organic carbon reserve is huge influenced by human land use.

  12. 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 ...

  13. Carbon diffusion in niobium

    International Nuclear Information System (INIS)

    An attempt is made to find out the reasons for deviations in the literary data on carbon diffusion in niobium. Methods of layer-by-layer radiometric analysis and measuring the internal friction are applied for this purpose. It is shown that penetration curves can be presented as a sum of two exponents which describe the distribution of active carbon in the surface and depth layers. Carbon diffusion parameters calculated in the above two regions are noticeably different, which can be the reason for deviations in the literary data. The temperature dependence of carbon diffusion coefficients in niobium at 677-1300 deg C in found which corresponds to the interstitial diffusion coe icient

  14. 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.

  15. 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.

  16. 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, ...

  17. 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...

  18. 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.

  19. 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.

  20. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Safety Network Community Outreach Resource Center CO Poster Contest Toy Recall Statistics Pool Safely Home / Safety Education / ... VIDEO CPSC announces winners of carbon monoxide poster contest View the blog SAFETY GUIDE Clues You Can ...

  1. 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 ... CO Blogs Research & Statistics January 07, 2016 Non-Fire Carbon Monoxide Deaths Associated with the Use of ...

  2. 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 ...

  3. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Other CO Topics Safety Tips Recalls and News Questions and Answers Charcoal Portable Heaters & Camping Equipment Home Heating Equipment On Safety Blogs: CO Safety More CO Blogs Research & Statistics January 07, 2016 Non-Fire Carbon Monoxide ...

  4. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Import Safety International Recall Guidance Civil and Criminal Penalties Federal Court Orders ... 07, 2016 Non-Fire Carbon Monoxide Deaths Associated with the Use of Consumer Products 2012 ...

  5. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... On Safety Blogs: CO Safety More CO Blogs Research & Statistics January 07, 2016 Non-Fire Carbon Monoxide ... Inside CPSC: Recalls Safety Education Regulations, Laws & Standards Research & Statistics Business & Manufacturing Small Business Resources International Newsroom ...

  6. Understanding carbon compensation

    International Nuclear Information System (INIS)

    Today, everyone can compensate its carbon emissions on the Internet in few mouse clicks. But what is the meaning of this compensation? What are the mechanisms of voluntary compensation in the framework of the Kyoto protocol? How to participate to this system and to what organisation a company or an individual can call in to reduce his carbon footprint? Carbon compensation is one of the numerous instruments invented to fight against global warming. When it is not possible to reduce our own emissions, we can compensate them by financing projects allowing to reduce the emissions of another company or collectivity. In this book, the authors answer the questions regarding the mechanisms, implementation and efficiency of carbon compensation. (J.S.)

  7. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Statistics January 07, 2016 Non-Fire Carbon Monoxide Deaths Associated with the Use of Consumer Products 2012 Annual Estimates October 13, 2015 Incidents, Deaths, and In-Depth Investigations Associated with Non-Fire ...

  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. Effect of biostimulation on biodegradation of dissolved organic carbon in biological granular activated carbon filters

    Directory of Open Access Journals (Sweden)

    K. Tihomirova

    2012-03-01

    Full Text Available The addition of labile organic carbon (LOC to enhance the biodegradation rate of dissolved organic carbon (DOC in biological columns was studied. Acetate standard solution (NaAc and LB (Luria Bertrani medium were used as LOC as biostimulants in glass column system used for measurements of biodegradable dissolved organic carbon (BDOC. The addition of LOC related with the increase of total DOC in sample. The concentration of BDOC increased up to 7 and 5 times and was utilized after 24 min. contact time. The biodegradation rate constant was increased at least 8 times during adaptation-biostimulation period. There was a strong positive correlation between the biodegradation rate constant and the concentration of BDOC. Biostimulation period ranged from 24 to 53 h for NaAc biostimulant and from 20 to 168 h for LB. The study has shown that LOC could be used as stimulator to enhance the biodegradation rate of DOC during biofiltration.

  10. Carbon Footprint of Thermowood

    OpenAIRE

    Nordlund, Teemu

    2015-01-01

    Purpose of this Bachelor’s Thesis was to evaluate the carbon footprint of thermally modified wood and its manufacturing process and transportation cycle for several different ThermoWood producer. Research included the whole production cycle from harvesting raw wood to ThermoWood transportation in destination area. Carbon dioxide emissions from these areas were determined and calculated for every ThermoWood producer at first hand. Calculations were based on the PAS 2050:2011, which is ...

  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. A supercritical carbon dioxide plasma process for preparing tungsten oxide nanowires.

    Science.gov (United States)

    Kawashima, Ayato; Nomura, Shinfuku; Toyota, Hiromichi; Takemori, Toshihiko; Mukasa, Shinobu; Maehara, Tsunehiro

    2007-12-12

    A supercritical carbon dioxide (CO(2)) plasma process for fabricating one-dimensional tungsten oxide nanowires coated with amorphous carbon is presented. High-frequency plasma was generated in supercritical carbon dioxide at 20 MPa by using tungsten electrodes mounted in a supercritical cell, and subsequently an organic solvent was introduced with supercritical carbon dioxide into the plasma. Electron microscopy and Raman spectroscopy investigations of the deposited materials showed the production of tungsten oxide nanowires with or without an outer layer. The nanowires with an outer layer exhibited a coaxial structure with an outer concentric layer of amorphous carbon and an inner layer of tungsten oxide with a thickness and diameter of 20-30 and 10-20 nm, respectively. PMID:20442477

  13. A supercritical carbon dioxide plasma process for preparing tungsten oxide nanowires

    International Nuclear Information System (INIS)

    A supercritical carbon dioxide (CO2) plasma process for fabricating one-dimensional tungsten oxide nanowires coated with amorphous carbon is presented. High-frequency plasma was generated in supercritical carbon dioxide at 20 MPa by using tungsten electrodes mounted in a supercritical cell, and subsequently an organic solvent was introduced with supercritical carbon dioxide into the plasma. Electron microscopy and Raman spectroscopy investigations of the deposited materials showed the production of tungsten oxide nanowires with or without an outer layer. The nanowires with an outer layer exhibited a coaxial structure with an outer concentric layer of amorphous carbon and an inner layer of tungsten oxide with a thickness and diameter of 20-30 and 10-20 nm, respectively

  14. Spectroscopy of 20F levels

    International Nuclear Information System (INIS)

    From a study of the 19F(n,γ) reaction with thermal neutrons incident on a Teflon target, 168 γ rays have been detected and incorporated into a level scheme of 20F consisting of 35 previously known levels and a new one at 5939 keV. Two low-energy primary E1 transitions of energies 584 and 665 keV together account for more than half of the total capture cross section. They populate, respectively, states at 6018 and 5936 keV (both Jπ=2-). These states are also excited strongly in the 19F(d,p) reaction. From each of these states, 17 γ rays were observed to the lower-lying states. These γ rays constitute the largest number of branches reported from any nuclear bound state. A weak (6±1μb)γ ray of energy 4630.6±0.9 keV, placed as a transition between the neutron-capturing state (which is a 0+ and 1+ mixture) and the 1971-keV, (3-) state, might represent the first observation of a primary M2 transition in the (n,γ) reaction. The total thermal-neutron-capture cross section of 19F was measured as 9.51±0.09 mb; and the neutron separation energy of 20F as 6601.35±0.04 keV. Estimates of direct neutron capture have been made using physically realistic optical-model parameters. These model estimates are in reasonable agreement with the measured (partial) cross sections. While constructing the (n,γ) level scheme, the existing data on bound levels in 20F were critically evaluated. The lifetime values for many levels are poorly known. The lifetimes for 25 levels were measured by the Doppler-shift-attenuation method using the inverse reaction 2H(19F, pγ) on implanted deuterium targets. The experimental level properties such as excitation energies, Jπ assignments, branching ratios, and lifetimes are compared with the results from a large-basis shell-model calculation

  15. 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.

  16. 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

  17. 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.

  18. Carbon exchange between ecosystems and atmosphere in the Czech Republic is affected by climate factors

    International Nuclear Information System (INIS)

    By comparing five ecosystem types in the Czech Republic over several years, we recorded the highest carbon sequestration potential in an evergreen Norway spruce forest (100%) and an agroecosystem (65%), followed by European beech forest (25%) and a wetland ecosystem (20%). Because of a massive ecosystem respiration, the final carbon gain of the grassland was negative. Climate was shown to be an important factor of carbon uptake by ecosystems: by varying the growing season length (a 22-d longer season in 2005 than in 2007 increased carbon sink by 13%) or by the effect of short- term synoptic situations (e.g. summer hot and dry days reduced net carbon storage by 58% relative to hot and wet days). Carbon uptake is strongly affected by the ontogeny and a production strategy which is demonstrated by the comparison of seasonal course of carbon uptake between coniferous (Norway spruce) and deciduous (European beech) stands. - Highlights: → Highest carbon sequestration potential in evergreen Norway spruce forest (100%) and an agroecosystem (65%), followed by European beech forest (25%) and a wetland ecosystem (20%). → The final carbon gain of the grassland was negative (massive ecosystem respiration). → Climate is important factor of net primary productivity. → Carbon uptake is strongly affected by the ontogeny and a production strategy of ecosystem. - Identification of the apparent differences in the carbon storage by different ecosystem types.

  19. Corrosion behavior of carbon steel in wet Na-bentonite medium

    International Nuclear Information System (INIS)

    Corrosion behaviors of carbon steel in wet Na-bentonite medium were studied. Corrosion rate of carbon steel in wet bentonite was measured to be 20 μm/yr at 25 deg C using the AC impedance technique. This value is agreed with that obtained by weight loss at 40 deg C for 1 year. The effect of bicarbonate ion on the corrosion of carbon steel in wet bentonite was also evaluated. The carbon steels in wet bentonite having 0.001, 0.01, and 0.1 M concentration of bicarbonate ion gave corrosion rates of 20, 8, and 0.2 μm/yr, respectively. Corrosion potentials of specimens were also measured and compared with the AC impedance results. Both results indicated that bicarbonate ion could effectively reduce the corrosion rate of carbon steels in bentonite due to the formation of protective layer on the carbon steel. (author)

  20. Surface State of Carbon Fibers Modified by Electrochemical Oxidation

    Institute of Scientific and Technical Information of China (English)

    Yunxia GUO; Jie LIU; Jieying LIANG

    2005-01-01

    Surface of polyacrylonitrile (PAN)-based carbon fibers was modified by electrochemical oxidation. The modification effect on carbon fibers surface was explored using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Results showed that on the modified surface of carbon fibers, the carbon contents decreased by 9.7% and the oxygen and nitrogen contents increased by 53.8% and 7.5 times, respectively. The surface roughness and the hydroxyl and carbonyl contents also increased. The surface orientation index was reduced by 1.5%which decreased tensile strength of carbon fibers by 8.1%, and the microcrystalline dimension also decreased which increased the active sites of carbon fiber surface by 78%. The physical and chemical properties of carbon fibers surface were modified through the electrochemical oxidative method, which improved the cohesiveness between the fibers and resin matrix and increased the interlaminar shear strength (ILSS) of carbon fibers reinforced epoxy composite (CFRP) over 20%.

  1. Tillage Effect on Organic Carbon in a Purple Paddy Soil

    Institute of Scientific and Technical Information of China (English)

    HUANG Xue-Xia; GAO Ming; WEI Chao-Fu; XIE De-Ti; PAN Gen-Xing

    2006-01-01

    The distribution and storage of soil organic carbon (SOC) based on a long-term experiment with various tillage systems were studied in a paddy soil derived from purple soil in Chongqing, China. Organic carbon storage in the 0-20and 0-40 cm soil layers under different tillage systems were in an order: ridge tillage with rice-rape rotation (RT-rr)> conventional tillage with rice only (CT-r) > ridge tillage with rice only (RT-r) > conventional tillage with rice-rape rotation (CT-rr). The RT-rr system had significantly higher levels of soil organic carbon in the 0-40 cm topsoil, while the proportion of the total remaining organic carbon in the total soil organic carbon in the 0-10 cm layer was greatest in the RT-rr system. This was the reason why the RT-rr system enhanced soil organic carbon storage. These showed that tillage system type was crucial for carbon storage. Carbon levels in soil humus and crop-yield results showed that the RT-rr system enhanced soil fertility and crop productivity. Adoption of this tillage system would be beneficial both for environmental protection and economic development.

  2. Chernobyl - 20 years and beyond

    International Nuclear Information System (INIS)

    In commemoration of the Chernobyl accident 20 years ago, the French society for radiation protection (S.F.R.P.) and the Belgian society for radiation protection (B.V.S.A.B.R.) organise jointly a one day colloquium in Brussels. This colloquium is divided in two parts: the first one concerns the technical and organisational aspects of the accident with the scenario and its global impact, the international environmental radioactivity information exchange through the Chernobyl experience, the European Union (E.U.) assistance to mitigate the Chernobyl accident consequences, the crisis communication and management and the lessons learned from them; the second part is devoted to the medical and humanitarian aspects through the thyroid cancers after Chernobyl accident, the health effects in the European Union (E.U.) and the psychological factors affecting health after the Chernobyl disaster. (N.C.)

  3. A t20 tensor polarimeter

    International Nuclear Information System (INIS)

    A t20 tensor polarimeter using the 3He(d,p)4He reaction as analyzer has been designed and constructed. Upon its calibration, with a deuteron beam of known polarization, it has been used for measurements of the recoil deuteron polarization from πd elastic scattering. The polarimeter was designed such that the cylindrical symmetry required for the polarimeter could be constructed for any given incident deuteron beam geometry, and was aligned independently on such experimental parameters as the position of the beam centroid, beam intensity distribution, etc. There are contributions from it11 and t22, and therefore most likely from t21 as well, is such symmetry is not maintained. It was found that if the incident deuteron intensity distribution is cylindrically symmetric, then contributions from these components can be neglected on average, provided the polarimeter face is larger than the beam size and the beam centroid is placed on the symmetry axis

  4. 20% Research & Design Science Project

    Science.gov (United States)

    Spear, Beth A.

    2015-04-01

    A project allowing employees to use 15 % of their time on independent projects was established at 3M in the 1950's. The result of this project included products like post it notes and masking tape. Google allows its employees to use 20% of their time on independently pursued projects. The company values creativity and innovation. Employees are allowed to explore projects of interest to them one day out of the week, 20 % of their work week. Products like AdSense, Gmail, Google Transit, Google News, and Google Talk are the result of this 20 % program. My school is implementing the Next Generation Science Standards (NGSS) as part of our regularly scheduled curriculum review. These new standards focus on the process of learning by doing and designing. The NGSS are very hands on and active. The new standards emphasize learning how to define, understand and solve problems in science and technology. In today's society everyone needs to be familiar with science and technology. This project allows students to develop and practice skills to help them be more comfortable and confident with science and technology while exploring something of interest to them. This project includes three major parts: research, design, and presentation. Students will spend approximately 2-4 weeks defining a project proposal and educating themselves by researching a science and technology topic that is of interest to them. In the next phase, 2-4 weeks, students design a product or plan to collect data for something related to their topic. The time spent on research and design will be dependant on the topic students select. Projects should be ambitious enough to encompass about six weeks. Lastly a presentation or demonstration incorporating the research and design of the project is created, peer reviewed and presented to the class. There are some problems anticipated or already experienced with this project. It is difficult for all students to choose a unique topic when you have large class sizes

  5. Chernobyl - 20 years and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Lacronique, J.F. [Institut de Radioprotection et de Surete Nucleaire, 92 - Fontenay-aux-Roses (France); Deconinck, F.; Govaerts, P.; Eggermont, C. [SCK-CEN - Studiecentrum voor Kernenergie, Centre d' Etude de l' Energie Nucleaire, Mol (Belgium); Cort, M. de [Institute for Environment and Sustainability, DG JRC EC (Italy); Joulia, J.P. [EuropeAid Co-operation Office, EC, Brussels (Belgium); Dal, A.H.; Balonov, M. [International Atomic Energy Agency (IAEA), Vienna (Austria); Kenigsberg, J. [Commission on Radiation protection, council of ministry (Belarus); Hindie, E. [Universites Paris, 75 (France); Havenaar, M. [Amsterdam Univ. (Netherlands)

    2006-07-01

    In commemoration of the Chernobyl accident 20 years ago, the French society for radiation protection (S.F.R.P.) and the Belgian society for radiation protection (B.V.S.A.B.R.) organise jointly a one day colloquium in Brussels. This colloquium is divided in two parts: the first one concerns the technical and organisational aspects of the accident with the scenario and its global impact, the international environmental radioactivity information exchange through the Chernobyl experience, the European Union (E.U.) assistance to mitigate the Chernobyl accident consequences, the crisis communication and management and the lessons learned from them; the second part is devoted to the medical and humanitarian aspects through the thyroid cancers after Chernobyl accident, the health effects in the European Union (E.U.) and the psychological factors affecting health after the Chernobyl disaster. (N.C.)

  6. 20-MW Magnicon for ILC

    Energy Technology Data Exchange (ETDEWEB)

    Jay L. Hirshfield

    2006-11-29

    The 1.3 GHz RF power to drive ILC is now planned to be supplied by 600-1200, 10-MW peak power multi-beam klystrons. In this project, a conceptual design for 1.3 GHz magnicons with 20 MW peak power was developed as an alternative to the klystrons, with the possibility of cutting in half the numbers of high-power tubes and associated components. Design of a conventional magnicon is described, using TM110 modes in all cavities, as well as design of a modified magnicon with a TE111 mode output cavity. The latter has the advantage of much lower surface fields than the TM110 mode, with no loss of output power or electronic efficiency.

  7. 20-MW Magnicon for ILC

    International Nuclear Information System (INIS)

    The 1.3 GHz RF power to drive ILC is now planned to be supplied by 600-1200, 10-MW peak power multi-beam klystrons. In this project, a conceptual design for 1.3 GHz magnicons with 20 MW peak power was developed as an alternative to the klystrons, with the possibility of cutting in half the numbers of high-power tubes and associated components. Design of a conventional magnicon is described, using TM110 modes in all cavities, as well as design of a modified magnicon with a TE111 mode output cavity. The latter has the advantage of much lower surface fields than the TM110 mode, with no loss of output power or electronic efficiency

  8. 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

  9. Determinations of the Configuration of C-20 in Derivatives of Adynerin Using DFT/HF Methods

    Institute of Scientific and Technical Information of China (English)

    HUA Yan; REN Jie; CHEN Chang-xiang; ZHU Hua-jie

    2007-01-01

    The configurations of C-20 in derivatives of novel 5α-adynerin type, co-existing glycoside in pair, were identified with the calculated chemical shifts of carbon at the B3LYP/6-311 + G(2d,p) level. These glycosides are unusual cardic aglycones without the common olefin bond in ring E.

  10. Interleukin-20 promotes airway remodeling in asthma.

    Science.gov (United States)

    Gong, Wenbin; Wang, Xin; Zhang, Yuguo; Hao, Junqing; Xing, Chunyan; Chu, Qi; Wang, Guicheng; Zhao, Jiping; Wang, Junfei; Dong, Qian; Liu, Tian; Zhang, Yuanyuan; Dong, Liang

    2014-12-01

    Previous studies have demonstrated that interleukin-20 (IL-20) is a pro-inflammatory cytokine, and it has been implicated in psoriasis, lupus nephritis, rheumatoid arthritis, atherosclerosis, and ulcerative colitis. Little is known about the effects of IL-20 in airway remodeling in asthma. The aim of our study was to demonstrate the function of IL-20 in airway remodeling in asthma. To identify the expression of IL-20 and its receptor, IL-20R1/IL-20R2, in the airway epithelium in bronchial tissues, bronchial biopsy specimens were collected from patients and mice with asthma and healthy subjects and stained with specific antibodies. To characterize the effects of IL-20 in asthmatic airway remodeling, we silenced and stimulated IL-20 in cell lines isolated from mice by shRNA and recombinant protein approaches, respectively, and detected the expression of α-SMA and FN-1 by Western blot analysis. First, overexpression of IL-20 and its receptor, IL-20R1/IL-20R2, was detected in the airway epithelium collected from patients and mice with asthma. Second, IL-20 increased the expression of fibronectin-1 and α-SMA, and silencing of IL-20 in mouse lung epithelial (MLE)-12 cells decreased the expression of fibronectin-1 and α-SMA. IL-20 may be a critical cytokine in airway remodeling in asthma. This study indicates that targeting IL-20 and/or its receptors may be a new therapeutic strategy for asthma. PMID:25028099

  11. 22 CFR 20.4 - Retirement benefits.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Retirement benefits. 20.4 Section 20.4 Foreign Relations DEPARTMENT OF STATE PERSONNEL BENEFITS FOR CERTAIN FORMER SPOUSES § 20.4 Retirement benefits. (a) Type of benefits. (1) A former spouse who meets the qualification requirements of § 20.3 is entitled...

  12. 22 CFR 20.5 - Survivor benefits.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Survivor benefits. 20.5 Section 20.5 Foreign Relations DEPARTMENT OF STATE PERSONNEL BENEFITS FOR CERTAIN FORMER SPOUSES § 20.5 Survivor benefits. (a) Type of benefits. A former spouse who meets the eligibility requirements of § 20.3 is entitled...

  13. [Estimation for vegetation carbon storage in Tiantong National Forest Park].

    Science.gov (United States)

    Guo, Chun-Zi; Wu, Yang-Yang; Ni, Jian

    2014-11-01

    Based on the field investigation and the data combination from literature, vegetation carbon storage, carbon density, and their spatial distribution were examined across six forest community types (Schima superba--Castanopsis fargesii community, S. superba--C. fargesii with C. sclerophylla community, S. superba--C. fargesii with Distylium myricoides community, Illicium lanceolatum--Choerospondias axillaris community, Liquidambar formosana--Pinus massoniana community and Hedyotis auricularia--Phylostachys pubescens community) in Tiantong National Forest Park, Zhejiang Province, by using the allometric biomass models for trees and shrubs. Results showed that: Among the six communities investigated, carbon storage and carbon density were highest in the S. superba--C. fargesii with C. sclerophylla community (storage: 12113.92 Mg C; density: 165.03 Mg C · hm(-2)), but lowest in the I. lanceolatum--C. axillaris community (storage: 680.95 Mg C; density: 101.26 Mg C · hm(-2)). Carbon storage was significantly higher in evergreen trees than in deciduous trees across six communities. Carbon density ranged from 76.08 to 144.95 Mg C · hm(-2), and from 0. 16 to 20. 62 Mg C · hm(-2) for evergreen trees and deciduous trees, respectively. Carbon storage was highest in stems among tree tissues in the tree layer throughout communities. Among vegetation types, evergreen broad-leaved forest had the highest carbon storage (23092.39 Mg C), accounting for 81.7% of the total carbon storage in all forest types, with a car- bon density of 126.17 Mg C · hm(-2). Total carbon storage for all vegetation types in Tiantong National Forest Park was 28254.22 Mg C, and the carbon density was 96.73 Mg C · hm(-2). PMID:25898604

  14. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    Energy Technology Data Exchange (ETDEWEB)

    David A. Green; Thomas Nelson; Brian S. Turk; Paul Box; Weijiong Li; Raghubir P. Gupta

    2005-07-01

    This report describes research conducted between April 1, 2005 and June 30, 2005 on the use of dry regenerable sorbents for removal of carbon dioxide from flue gas from coal combustion and synthesis gas from coal gasification. Supported sodium carbonate sorbents removed up to 76% of the carbon dioxide from simulated flue gas in a downflow cocurrent flow reactor system, with an approximate 15 second gas-solid contact time. This reaction proceeds at temperatures as low as 25 C. Lithium silicate sorbents remove carbon dioxide from high temperature simulated flue gas and simulated synthesis gas. Both sorbent types can be thermally regenerated and reused. The lithium silicate sorbent was tested in a thermogravimetric analyzer and in a 1-in quartz reactor at atmospheric pressure; tests were also conducted at elevated pressure in a 2-in diameter high temperature high pressure reactor system. The lithium sorbent reacts rapidly with carbon dioxide in flue gas at 350-500 C to absorb about 10% of the sorbent weight, then continues to react at a lower rate. The sorbent can be essentially completely regenerated at temperatures above 600 C and reused. In atmospheric pressure tests with synthesis gas of 10% initial carbon dioxide content, the sorbent removed over 90% of the carbon dioxide. An economic analysis of a downflow absorption process for removal of carbon dioxide from flue gas with a supported sodium carbonate sorbent suggests that a 90% efficient carbon dioxide capture system installed at a 500 MW{sub e} generating plant would have an incremental capital cost of $35 million ($91/kWe, assuming 20 percent for contingencies) and an operating cost of $0.0046/kWh. Assuming capital costs of $1,000/kW for a 500 MWe plant the capital cost of the down flow absorption process represents a less than 10% increase, thus meeting DOE goals as set forth in its Carbon Sequestration Technology Roadmap and Program Plan.

  15. Observed and model simulated 20th century Arctic temperature variability: Canadian Earth System Model CanESM2

    OpenAIRE

    Chylek, P.; Li, J.; Dubey, M. K.; Wang, M.; Lesins, G.

    2011-01-01

    We present simulations of the 20th century Arctic temperature anomaly from the second generation Canadian Earth System Model (CanESM2). The new model couples together an atmosphere-ocean general circulation model, a land-vegetation model and terrestrial and oceanic interactive carbon cycle. It simulates well the observed 20th century Arctic temperature variability that includes the early and late 20th century warming periods and the intervening 1940–1970 period of substantial cooling. The add...

  16. Observed and model simulated 20th century Arctic temperature variability: Canadian Earth System Model CanESM2

    OpenAIRE

    Chylek, P.; Li, J.; Dubey, M. K.; Wang, M.; Lesins, G.

    2011-01-01

    We present simulations of the 20th century Arctic temperature anomaly from the second generation Canadian Earth System Model (CanESM2). The new model couples together an atmosphere-ocean general circulation model, a land-vegetation model and terrestrial and oceanic interactive carbon cycle. It simulates well the observed 20th century Arctic temperature variability that includes the early and late 20th century warming periods and the intervening 1940–1970 period of substantia...

  17. Storage of hydrogen on carbons; Stockage de l'hydrogene sur les carbones

    Energy Technology Data Exchange (ETDEWEB)

    Conard, J. [Centre National de la Recherche Scientifique, CNRS-CRMD, 45 - Orleans-la-Source (France)

    2000-07-01

    The storage of hydrogen on carbons, with densities above 10% hydrogen weight, can be used in the sector of transport. However, only the physical-sorption of this gas (which is almost perfect and boils at 20 K under atmospheric pressure) cannot explain this performance. A study of the possible sites for one hydrogen, which can take very different forms, is presented, in order to better understand the rational development of this storage mode which could reach about ten weight %. (O.M.)

  18. 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.

  19. Adsorption of dissolved natural organic matter by modified activated carbons.

    Science.gov (United States)

    Cheng, Wei; Dastgheib, Seyed A; Karanfil, Tanju

    2005-06-01

    Adsorption of dissolved natural organic matter (DOM) by virgin and modified granular activated carbons (GACs) was studied. DOM samples were obtained from two water treatment plants before (i.e., raw water) and after coagulation/flocculation/sedimentation processes (i.e., treated water). A granular activated carbon (GAC) was modified by high temperature helium or ammonia treatment, or iron impregnation followed by high temperature ammonia treatment. Two activated carbon fibers (ACFs) were also used, with no modification, to examine the effect of carbon porosity on DOM adsorption. Size exclusion chromatography (SEC) and specific ultraviolet absorbance (SUVA(254)) were employed to characterize the DOMs before and after adsorption. Iron-impregnated (HDFe) and ammonia-treated (HDN) activated carbons showed significantly higher DOM uptakes than the virgin GAC. The enhanced DOM uptake by HDFe was due to the presence of iron species on the carbon surface. The higher uptake of HDN was attributed to the enlarged carbon pores and basic surface created during ammonia treatment. The SEC and SUVA(254) results showed no specific selectivity in the removal of different DOM components as a result of carbon modification. The removal of DOM from both raw and treated waters was negligible by ACF10, having 96% of its surface area in pores smaller than 1 nm. Small molecular weight (MW) DOM components were preferentially removed by ACF20H, having 33% of its surface area in 1--3 nm pores. DOM components with MWs larger than 1600, 2000, and 2700 Da of Charleston raw, Charleston-treated, and Spartanburg-treated waters, respectively, were excluded from the pores of ACF20H. In contrast to carbon fibers, DOM components from entire MW range were removed from waters by virgin and modified GACs. PMID:15927230

  20. 21 CFR 20.20 - Policy on disclosure of Food and Drug Administration records.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Policy on disclosure of Food and Drug Administration records. 20.20 Section 20.20 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PUBLIC INFORMATION General Policy § 20.20 Policy on disclosure of Food and...

  1. Dimethyl carbonate as potential reactant in non-catalytic biodiesel production by supercritical method

    OpenAIRE

    Ilham, Zul; Saka, Shiro

    2009-01-01

    In this study, the non-catalytic supercritical method has been studied in utilizing dimethyl carbonate. It was demonstrated that, the supercritical dimethyl carbonate process without any catalysts applied, converted triglycerides to fatty acid methyl esters with glycerol carbonate and citramalic acid as by-products, while free fatty acids were converted to fatty acid methyl esters with glyoxal. After 12 min of reaction at 350 °C/20 MPa, rapeseed oil treated with supercritical dimethyl carbona...

  2. Coordinated control of carbon and oxygen for ultra-low-carbon interstitial-free steel in a smelting process

    Institute of Scientific and Technical Information of China (English)

    Min Wang; Yan-ping Bao; Quan Yang; Li-hua Zhao; Lu Lin

    2015-01-01

    Low residual-free-oxygen before final de-oxidation was beneficial to improving the cleanness of ultra-low-carbon steel. For ul-tra-low-carbon steel production, the coordinated control of carbon and oxygen is a precondition for achieving low residual oxygen during the Ruhrstahl Heraeus (RH) decarburization process. In this work, we studied the coordinated control of carbon and oxygen for ultra-low-carbon steel during the basic oxygen furnace (BOF) endpoint and RH process using data statistics, multiple linear regressions, and thermodynamics computations. The results showed that the aluminum yield decreased linearly with increasing residual oxygen in liquid steel. When the mass ratio of free oxygen and carbon ([O]/[C]) in liquid steel before RH decarburization was maintained between 1.5 and 2.0 and the carbon range was from 0.030wt%to 0.040wt%, the residual oxygen after RH natural decarburization was low and easily controlled. To satisfy the re-quirement for RH decarburization, the carbon and free oxygen at the BOF endpoint should be controlled to be between 297 × 10−6 and 400 × 10−6 and between 574 × 10−6 and 775 × 10−6, respectively, with a temperature of 1695 to 1715°C and a furnace campaign of 1000 to 5000 heats.

  3. Coordinated control of carbon and oxygen for ultra-low-carbon interstitial-free steel in a smelting process

    Science.gov (United States)

    Wang, Min; Bao, Yan-ping; Yang, Quan; Zhao, Li-hua; Lin, Lu

    2015-12-01

    Low residual-free-oxygen before final de-oxidation was beneficial to improving the cleanness of ultra-low-carbon steel. For ultra-low-carbon steel production, the coordinated control of carbon and oxygen is a precondition for achieving low residual oxygen during the Ruhrstahl Heraeus (RH) decarburization process. In this work, we studied the coordinated control of carbon and oxygen for ultra-low-carbon steel during the basic oxygen furnace (BOF) endpoint and RH process using data statistics, multiple linear regressions, and thermodynamics computations. The results showed that the aluminum yield decreased linearly with increasing residual oxygen in liquid steel. When the mass ratio of free oxygen and carbon ([O]/[C]) in liquid steel before RH decarburization was maintained between 1.5 and 2.0 and the carbon range was from 0.030wt% to 0.040wt%, the residual oxygen after RH natural decarburization was low and easily controlled. To satisfy the requirement for RH decarburization, the carbon and free oxygen at the BOF endpoint should be controlled to be between 297 × 10-6 and 400 × 10-6 and between 574 × 10-6 and 775 × 10-6, respectively, with a temperature of 1695 to 1715°C and a furnace campaign of 1000 to 5000 heats.

  4. Optimization of interfacial microstructure and mechanical properties of carbon fiber/epoxy composites via carbon nanotube sizing

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Hongwei; Sui, Xianhang; Zhao, Zhongbo; Xu, Zhiwei; Chen, Lei, E-mail: chenlei@tjpu.edu.cn; Deng, Hui; Liu, Ya; Qian, Xiaoming, E-mail: qianxiaoming@tjpu.edu.cn

    2015-08-30

    Highlights: • Multiple sizing treatments were used to modify the surface of carbon fiber with carbon nanotubes. • The distribution state of carbon nanotubes in interface had a great effect on the performance of carbon fiber composites. • Interfacial microstructure changes brought by sizing treatment were detected by energy dispersive X-ray spectroscopy and atomic force microscope. • Gradient interphase composed of carbon nanotubes and epoxy was favorable to improve the mechanical properties of carbon composites. - Abstract: Repetitious sizing treatment was used to modify the carbon fiber (CF) surface with carbon nanotubes (CNTs) for improving interfacial properties of CF/epoxy composites. Interlaminar shear and flexural results showed that mechanical properties of composites were significantly depended on the dispersion state and contents of CNTs in interfacial regions. Increases of 13.45% in interlaminar shear strength and 20.31% in flexural strength were achieved in quintuple sized-CF/epoxy composites, whereas excessive CNTs led to decrease of interfacial performance due to defects induced by agglomerated CNTs. Energy dispersive X-ray spectroscopy and force modulation atomic force microscope were used to detect the structure of interfacial phase and results indicated that gradient interfacial structure with various thicknesses was formed due to CNT incorporation. This means that such a simple and efficient method to improve interfacial performance of composites via regulating the fiber–matrix interphase structure was developed and showed great commercial application potential.

  5. Optimization of interfacial microstructure and mechanical properties of carbon fiber/epoxy composites via carbon nanotube sizing

    International Nuclear Information System (INIS)

    Highlights: • Multiple sizing treatments were used to modify the surface of carbon fiber with carbon nanotubes. • The distribution state of carbon nanotubes in interface had a great effect on the performance of carbon fiber composites. • Interfacial microstructure changes brought by sizing treatment were detected by energy dispersive X-ray spectroscopy and atomic force microscope. • Gradient interphase composed of carbon nanotubes and epoxy was favorable to improve the mechanical properties of carbon composites. - Abstract: Repetitious sizing treatment was used to modify the carbon fiber (CF) surface with carbon nanotubes (CNTs) for improving interfacial properties of CF/epoxy composites. Interlaminar shear and flexural results showed that mechanical properties of composites were significantly depended on the dispersion state and contents of CNTs in interfacial regions. Increases of 13.45% in interlaminar shear strength and 20.31% in flexural strength were achieved in quintuple sized-CF/epoxy composites, whereas excessive CNTs led to decrease of interfacial performance due to defects induced by agglomerated CNTs. Energy dispersive X-ray spectroscopy and force modulation atomic force microscope were used to detect the structure of interfacial phase and results indicated that gradient interfacial structure with various thicknesses was formed due to CNT incorporation. This means that such a simple and efficient method to improve interfacial performance of composites via regulating the fiber–matrix interphase structure was developed and showed great commercial application potential

  6. African Savanna-Forest Boundary Dynamics: A 20-Year Study

    Science.gov (United States)

    Cuni-Sanchez, Aida; White, Lee J. T.; Calders, Kim; Jeffery, Kathryn J.; Abernethy, Katharine; Burt, Andrew; Disney, Mathias; Gilpin, Martin; Gomez-Dans, Jose L.; Lewis, Simon L.

    2016-01-01

    Recent studies show widespread encroachment of forest into savannas with important consequences for the global carbon cycle and land-atmosphere interactions. However, little research has focused on in situ measurements of the successional sequence of savanna to forest in Africa. Using long-term inventory plots we quantify changes in vegetation structure, above-ground biomass (AGB) and biodiversity of trees ≥10 cm diameter over 20 years for five vegetation types: savanna; colonising forest (F1), monodominant Okoume forest (F2); young Marantaceae forest (F3); and mixed Marantaceae forest (F4) in Lopé National Park, central Gabon, plus novel 3D terrestrial laser scanning (TLS) measurements to assess forest structure differences. Over 20 years no plot changed to a new stage in the putative succession, but F1 forests strongly moved towards the structure, AGB and diversity of F2 forests. Overall, savanna plots showed no detectable change in structure, AGB or diversity using this method, with zero trees ≥10 cm diameter in 1993 and 2013. F1 and F2 forests increased in AGB, mainly as a result of adding recruited stems (F1) and increased Basal Area (F2), whereas F3 and F4 forests did not change substantially in structure, AGB or diversity. Critically, the stability of the F3 stage implies that this stage may be maintained for long periods. Soil carbon was low, and did not show a successional gradient as for AGB and diversity. TLS vertical plant profiles showed distinctive differences amongst the vegetation types, indicating that this technique can improve ecological understanding. We highlight two points: (i) as forest colonises, changes in biodiversity are much slower than changes in forest structure or AGB; and (ii) all forest types store substantial quantities of carbon. Multi-decadal monitoring is likely to be required to assess the speed of transition between vegetation types. PMID:27336632

  7. African Savanna-Forest Boundary Dynamics: A 20-Year Study.

    Science.gov (United States)

    Cuni-Sanchez, Aida; White, Lee J T; Calders, Kim; Jeffery, Kathryn J; Abernethy, Katharine; Burt, Andrew; Disney, Mathias; Gilpin, Martin; Gomez-Dans, Jose L; Lewis, Simon L

    2016-01-01

    Recent studies show widespread encroachment of forest into savannas with important consequences for the global carbon cycle and land-atmosphere interactions. However, little research has focused on in situ measurements of the successional sequence of savanna to forest in Africa. Using long-term inventory plots we quantify changes in vegetation structure, above-ground biomass (AGB) and biodiversity of trees ≥10 cm diameter over 20 years for five vegetation types: savanna; colonising forest (F1), monodominant Okoume forest (F2); young Marantaceae forest (F3); and mixed Marantaceae forest (F4) in Lopé National Park, central Gabon, plus novel 3D terrestrial laser scanning (TLS) measurements to assess forest structure differences. Over 20 years no plot changed to a new stage in the putative succession, but F1 forests strongly moved towards the structure, AGB and diversity of F2 forests. Overall, savanna plots showed no detectable change in structure, AGB or diversity using this method, with zero trees ≥10 cm diameter in 1993 and 2013. F1 and F2 forests increased in AGB, mainly as a result of adding recruited stems (F1) and increased Basal Area (F2), whereas F3 and F4 forests did not change substantially in structure, AGB or diversity. Critically, the stability of the F3 stage implies that this stage may be maintained for long periods. Soil carbon was low, and did not show a successional gradient as for AGB and diversity. TLS vertical plant profiles showed distinctive differences amongst the vegetation types, indicating that this technique can improve ecological understanding. We highlight two points: (i) as forest colonises, changes in biodiversity are much slower than changes in forest structure or AGB; and (ii) all forest types store substantial quantities of carbon. Multi-decadal monitoring is likely to be required to assess the speed of transition between vegetation types. PMID:27336632

  8. Implications of carbon dust emission for terrestrail carbon cycling and carbon accounting

    Science.gov (United States)

    Wind erosion preferentially removes the finest carbon- and nutrient-rich soil fractions, and consequently its role may be significant within terrestrial carbon (C) cycles. However, the impacts of wind erosion on soil organic carbon (SOC) redistribution are not considered in most carbon cycle models,...

  9. Carbon foam/hydroxyapatite coating for carbon/carbon composites: Microstructure and biocompatibility

    International Nuclear Information System (INIS)

    To improve the surface biocompatibility of carbon/carbon composites, a carbon foam/hydroxyapatite coating was applied using a combination method of slurry procedure and ultrasound-assisted electrochemical deposition procedure. The morphology, microstructure and chemical composition of the coating were investigated by scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and X-ray diffraction. The biocompatibility of the carbon foam/hydroxyapatite coating was investigated by osteoblast-like MG63 cell culture tests. The results showed that the carbon foam could provide a large number of pores on the surface of carbon/carbon composites. The hydroxyapatite crystals could infiltrate into the pores and form the carbon foam/hydroxyapatite coating. The coating covered the carbon/carbon composites fully and uniformly with slice morphology. The cell response tests showed that the MG63 cells on carbon foam/hydroxyapatite coating had a better cell adhesion and cell proliferation than those on uncoated carbon/carbon composites. The carbon foam/hydroxyapatite coatings were cytocompatible and were beneficial to improve the biocompatibility. The approach presented here may be exploited for fabrication of carbon/carbon composite implant surfaces.

  10. Carbon and Oxygen Isotope Measurements of Ordinary Chondrite (OC) Meteorites from Antarctica Indicate Distinct Terrestrial Carbonate Species using a Stepped Acid Extraction Procedure Impacting Mars Carbonate Research

    Science.gov (United States)

    Evans, M. E.; Niles, P. B.; Locke, D.

    2015-12-01

    The purpose of this study is to characterize the stable isotope values of terrestrial, secondary carbonate minerals from five OC meteorites collected in Antarctica. These samples were selected for analysis based upon their size and collection proximity to known Martian meteorites. They were also selected based on petrologic type (3+) such that they were likely to be carbonate-free before falling to Earth. This study has two main tasks: 1) characterize the isotopic composition of terrestrial, secondary carbonate minerals formed on meteorites in Antarctica, and 2) study the mechanisms of carbonate formation in cold and arid environments with Antarctica as an analog for Mars. Two samples from each meteorite, each ~0.5g, was crushed and dissolved in pure phosphoric acid for 3 sequential reactions: a) Rx0 for 1 hour at 30°C, b) Rx1 for 18 hours at 30°C, and c) Rx2 for 3 hours at 150°C. CO2 was distilled by freezing with liquid nitrogen from each sample tube, then separated from organics and sulfides with a TRACE GC using a Restek HayeSep Q 80/100 6' 2mm stainless column, and then analyzed on a Thermo MAT 253 IRMS in Dual Inlet mode. This system was built at NASA/JSC over the past 3 years and proof tested with known carbonate standards to develop procedures, assess yield, and quantify expected uncertainties. Two distinct species of carbonates are found based on the stepped extraction technique: 1) Ca-rich carbonate released at low temperatures, and 2) Mg, or Fe-rich carbonate released at high temperatures. Preliminary results indicate that most of the carbonates present in the ordinary chondrites analyzed have δ13C=+5‰, which is consistent with formation from atmospheric CO2 δ13C=-7‰ at -20°C. The oxygen isotopic compositions of the carbonates vary between +4‰ and +34‰ with the Mg-rich and/or Fe-rich carbonates possessing the lowest δ18O values. This suggests that the carbonates formed under a wide range of temperatures. However, the carbonate oxygen

  11. Carbon nanotubes decorating methods

    Directory of Open Access Journals (Sweden)

    A.D. Dobrzańska-Danikiewicz

    2013-06-01

    Full Text Available Purpose: The work is to present and characterise various methods of depositing carbon nanotubes with nanoparticles of precious metals, and also to present the results of own works concerning carbon nanotubes coated with platinum nanoparticles.Design/methodology/approach: Electron transmission and scanning microscopy has been used for imaging the structure and morphology of the nanocomposites obtained and the distribution of nanoparticles on the surface of carbon nanotubes.Findings: The studies carried out with the HRTEM and SEM techniques have confirmed differences in morphology, homogeneity and density of depositing platinum nanoparticles on the surface of carbon nanotubes and its structure.Research limitations/implications: The studies conducted pertained to the process of decorating carbon nanotubes with platinum nanoparticles. Further works are planned aimed at extending the application scope of the newly developed methodology to include the methods of nanotubes decorating with the nanoparticles of other precious metals (mainly palladium and rhodium.Practical implications: CNTs-NPs (Carbon NanoTube-NanoParticles composites can be used as the active elements of sensors featuring high sensitivity, fast action, high selectivity and accuracy, in particular in medicine as cholesterol and glucoses sensors; in the automotive industry for the precision monitoring of working parameters in individual engine components; in environmental conservation to examine CO2, NOx, and CH4 concentrations and for checking leak-tightness and detecting hazardous substances in household and industrial gas installations.Originality/value: The comprehensive characterisation of the methods employed for fabricating nanocomposites consisting of carbon nanotubes deposited with Pt, Pd, Rh, Au, Ag nanoparticles with special consideration to the colloidal process.

  12. 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

  13. 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.

  14. Fluidized bed electrodes with high carbon loading for water desalination by capacitive deionization

    NARCIS (Netherlands)

    Doornbusch, G.J.; Dykstra, J.E.; Biesheuvel, P.M.; Suss, M.E.

    2016-01-01

    The use of carbon flow electrodes has significantly impacted electrochemical energy storage and capacitive deionization (CDI), but device performance is limited as these electrodes cannot surpass ∼20 wt% carbon while maintaining flowability. We here introduce flowable fluidized bed electrodes whi

  15. Hydrophobic-hydrophilic nanostructures synthesis on the polymers surfaces in low temperature carbon plasma

    International Nuclear Information System (INIS)

    Low-temperature (20-60 deg C) surface modification of polymers (polyethylene and polyurethane) by a method of pulsed ion-plasma carbon deposition was investigated. Optimal parameters suitable for 0.3-15 nm thick deposition of carbon mosaic hydrophobic-hydrophilic nanostructures having 10-500 nm sized clusters were determined

  16. 77 FR 19623 - Certain Welded Carbon Steel Standard Pipe from Turkey: Preliminary Results of Countervailing Duty...

    Science.gov (United States)

    2012-04-02

    ... Pipe and Tube Products from Turkey, 51 FR 7984 (March 7, 1986). \\2\\ See Antidumping or Countervailing... Administrative Review, in Part, 76 FR 78886 (December 20, 2011). \\12\\ See Certain Welded Carbon Steel Standare...: Certain Welded Carbon Steel Standard Pipe from Turkey, 72 FR 62837, 62838 (November 7, 2007) (Turkey...

  17. 20. German materials flow congress; 20. Deutscher Materialfluss-Kongress

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    Within the 20th German Material Flow Meeting of the VDI Wissensforum GmbH (Duesseldorf, Federal Republic of Germany) at 14th to 15th April, 2011 in Garching (Federal Republic of Germany) the following lectures were held: (1) From group logistics to service provider - The innovation process of Hermes Fulfilment GmbH (D. Urbanke); (2) Production structures of the future - Challenges for fabrics through the ages (M. Schenk); (3) Value-driven supply of materials for the implementation of a switching cabinet of great diesel engines (S. Meissner); (4) Material and optimisation of productions with APS - Real operation since January 2008 (M. Mayer); (5) Automation of the material flow in the production - Fully automatic supply of production using the multi-shuttle technology at Siemens site Amberg (M. Paehr); (6) Sustainable enhancement of the process efficiency at Demag Cranes Group (R. Harkort); (7) 'Activity-based logistics' Logistics at Strauss Innovation (A. Witte); (8) A new dimension in e-commerce: Handling of retours at the company Next (UK) - Tendencies and developments in E-Commerce - Handling of increasing quota of retours - A new intralogistic concept approach for handling retours - Green logistics at mail-order companies (V. Welsch); (9) Requirements concerning a tailor-made distribution logistics at office management wholesale trade (R. Barth); (10) New concepts for te distribution logistics - Trading Logistics Center Schweinfurt - The perfect combination of processes and technology for the delivery of an international free spare parts market (T. Nuss); (11) LEAN, BI, APS: Opposition or complementation (A. de Windt); (12) Next E-commerce Generations: How brand manufacturers generate new online sales channels via the utilisation of existing trading structures (M. Thomas); (13) From bus assembly to service provider for spare part logistics - Choice of location (U.J. Unger); (14) Design and implementation of a modular overall logistic system (M

  18. Microbially mediated carbon mineralization: Geoengineering a carbon-neutral mine

    Science.gov (United States)

    Power, I. M.; McCutcheon, J.; Harrison, A. L.; Wilson, S. A.; Dipple, G. M.; Southam, G.

    2013-12-01

    Ultramafic and mafic mine tailings are a potentially valuable feedstock for carbon mineralization, affording the mining industry an opportunity to completely offset their carbon emissions. Passive carbon mineralization has previously been documented at the abandoned Clinton Creek asbestos mine, and the active Diavik diamond mine and Mount Keith nickel mine, yet the majority of tailings remain unreacted. Examples of microbe-carbonate interactions at each mine suggest that biological pathways could be harnessed to promote carbon mineralization. In suitable environmental conditions, microbes can mediate geochemical processes to accelerate mineral dissolution, increase the supply of carbon dioxide (CO2), and induce carbonate precipitation, all of which may accelerate carbon mineralization. Tailings mineralogy and the availability of a CO2 point source are key considerations in designing tailings storage facilities (TSF) for optimizing carbon mineralization. We evaluate the efficacy of acceleration strategies including bioleaching, biologically induced carbonate precipitation, and heterotrophic oxidation of waste organics, as well as abiotic strategies including enhancing passive carbonation through modifying tailings management practices and use of CO2 point sources (Fig. 1). With the aim of developing carbon-neutral mines, implementation of carbon mineralization strategies into TSF design will be driven by economic incentives and public pressure for environmental sustainability in the mining industry. Figure 1. Schematic illustrating geoengineered scenarios for carbon mineralization of ultramafic mine tailings. Scenarios A and B are based on non-point and point sources of CO2, respectively.

  19. 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

  20. Hydrogen adsorption in doped porous carbons

    International Nuclear Information System (INIS)

    properties of doped microporous carbons (SWNTs and activated carbons). The raw nano-structured carbon materials are microporous activated carbons (BET specific surface area: 1600 m2/g), electric-arc closed-end single-walled carbon nano-tubes (SWNTs), and HiPCO SWNTs. They have been doped in the vapor phase by K, and Li (in order to obtain KC7, KC10, LiC18 SWNTs and LiC6, LiC18, KC24 activated carbons). The hydrogen adsorption-desorption isotherms of the doped activated carbons were obtained at room temperature and at 77 K, up to 3 MPa, by a volumetric method. The adsorption of D2 was studied in situ on doped nano-tubes and filaments by neutron diffraction on DIB experiment (ILL), at λ = 2.52 Angstroms, as a function of temperature [300-20 K] and pressure. Simultaneously the adsorption isotherms were recorded in the range 0-0.1 MPa [13]. Doping of microporous carbon by Li or K leads to an increase in the energy of adsorption of H2 or D2 molecules. Thus, the room temperature sorption capacities (at P≤3 MPa) can be higher than that of the raw materials after slight doping. However, the maximum H2 (or D2) storage measured at T≤ 77 K is lower than the one of pristine materials as the sites of adsorption are occupied by alkali ions inserted in the micropores [14]. The microporous adsorption sites of doped single-walled carbon nano-tubes, identified by neutron diffraction, are both the interstitial voids (in electric-arc or HiPCO tubes) in between the tubes and the central canals of the tubes (only in HiPCO tubes) [15]. We have also prepared nano-structured porous doped carbons by ball-milling carbon host materials with some dopant, such as alkali or alkaline earth metal. The new nano-porous carbons obtained by this method have been characterised and tested for their hydrogen-adsorption properties. [1] A. Chambers et al, J. Phys. Chem. B, 102, 4253, 1998; [2] A. C. Dillon et al, Nature, 386, 377, 1997; [3] J. Conard, Ann. Chim. Sci. Mat 26, 107, 2001; [4] A. Zuttel et al, Int

  1. Hydrogen adsorption in doped porous carbons

    International Nuclear Information System (INIS)

    properties of doped microporous carbons (SWNTs and activated carbons). The raw nano-structured carbon materials are microporous activated carbons (BET specific surface area: 1600 m2/g), electric-arc closed-end single-walled carbon nano-tubes (SWNTs), and HiPCO SWNTs. They have been doped in the vapour phase by K, and Li (in order to obtain KC7, KC10, LiC18 SWNTs and LiC6, LiC18, KC24 activated carbons). The hydrogen adsorption-desorption isotherms of the doped activated carbons were obtained at room temperature and at 77 K, up to 3 MPa, by a volumetric method. The adsorption of D2 was studied in situ on doped nano-tubes and nano-filaments by neutron diffraction on D1B experiment (ILL), at λ=2.52 Angstroms, as a function of temperature [300 - 20 K] and pressure. Simultaneously the adsorption isotherms were recorded in the range 0 - 0.1 MPa [13]. Doping of microporous carbon by Li or K leads to an increase in the energy of adsorption of H2 or D2 Molecules. Thus, the room temperature sorption capacities (al P≤3 MPa) can be higher than that of the raw materials after slight doping. However, the maximum H2 (or D2) storage measured at T ≤ 77 K is lower than the one of pristine Materials as the sites of adsorption are occupied by alkali ions inserted in the micropores [14]. The microporous adsorption sites of doped single-walled carbon nano-tubes, identified by neutron diffraction, are both the interstitial voids (in electric-arc or HiPCO tubes) in between the tubes and the central canals of the tubes (only in HiPCO tubes) [15]. We have also prepared nano-structured porous doped carbons by ball-milling carbon host materials with some dopant, such as alkali or alkaline earth metal. The new nano-porous carbons obtained by this method have been characterised and tested for their hydrogen-adsorption properties. References: [1]A. Chambers et al, J. Phys. Chem. B, 102, 4253,1998. [2]A. C. Dillon et al, Nature, 386, 377,1997. [3]J. Conard, Ann. Chim. Sci. Mat 26, 107, 2001. [4]A

  2. RESTORING SUSTAINABLE FORESTS ON APPALACHIAN MINED LANDS FOR WOOD PRODUCTS, RENEWABLE ENERGY, CARBON SEQUESTRATION, AND OTHER ECOSYSTEM SERVICES

    Energy Technology Data Exchange (ETDEWEB)

    J. Burger; J. Galbraith; T. Fox; G. Amacher; J. Sullivan; C. Zipper

    2003-12-18

    The overall purpose of this project is to evaluate the biological and economic feasibility of restoring high-quality forests on mined land, and to measure carbon sequestration and wood production benefits that would be achieved from forest restoration procedures. In this quarterly report, we present a preliminary comparison of the carbon sequestration benefits for two forest types used to convert abandoned grasslands for carbon sequestration. Annual mixed hardwood benefits, based on total stand carbon volume present at the end of a given year, range from a minimum of $0/ton of carbon to a maximum of $5.26/ton of carbon (low prices). White pine benefits based on carbon volume range from a minimum of $0/ton of carbon to a maximum of $18.61/ton of carbon (high prices). The higher maximum white pine carbon payment can primarily be attributed to the fact that the shorter rotation means that payments for white pine carbon are being made on far less cumulative carbon tonnage than for that of the long-rotation hardwoods. Therefore, the payment per ton of white pine carbon needs to be higher than that of the hardwoods in order to render the conversion to white pine profitable by the end of a rotation. These carbon payments may seem appealingly low to the incentive provider. However, payments (not discounted) made over a full rotation may add up to approximately $17,493/ha for white pine (30-year rotation), and $18,820/ha for mixed hardwoods (60-year rotation). The literature suggests a range of carbon sequestration costs, from $0/ton of carbon to $120/ton of carbon, although the majority of studies suggest a cost below $50/ ton of carbon, with van Kooten et al. (2000) suggesting a cutoff cost of $20/ton of carbon sequestered. Thus, the ranges of carbon payments estimated for this study fall well within the ranges of carbon sequestration costs estimated in previous studies.

  3. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    International Nuclear Information System (INIS)

    The objective of this project is to develop a simple, inexpensive process to separate CO(sub 2) as an essentially pure stream from a fossil fuel combustion system using a regenerable, sodium-based sorbent. The sorbent being used in this project is sodium carbonate which is converted to sodium bicarbonate, or ''baking soda,'' through reaction with carbon dioxide and water vapor. Sodium bicarbonate is regenerated to sodium carbonate when heated, producing a nearly pure CO(sub 2) stream after condensation of water vapor. This quarter, five cycle thermogravimetric tests were conducted at the Louisiana State University (LSU) with sodium bicarbonate Grade 3 (SBC(numbersign)3) which showed that carbonation activity declined slightly over 5 cycles following severe calcination conditions of 200 C in pure CO(sub 2). Three different sets of calcination conditions were tested. Initial carbonation activity (as measured by extent of reaction in the first 25 minutes) was greatest subsequent to calcination at 120 C in He, slightly less subsequent to calcination in 80% CO(sub 2)/20% H(sub 2)O, and lowest subsequent to calcination in pure CO(sub 2) at 200 C. Differences in the extent of reaction after 150 minutes of carbonation, subsequent to calcination under the same conditions followed the same trend but were less significant. The differences between fractional carbonation under the three calcination conditions declined with increasing cycles. A preliminary fixed bed reactor test was also conducted at LSU. Following calcination, the sorbent removed approximately 19% of the CO(sub 2) in the simulated flue gas. CO(sub 2) evolved during subsequent calcination was consistent with an extent of carbonation of approximately 49%. Following successful testing of SBC(numbersign)3 sorbent at RTI reported in the last quarter, a two cycle fluidized bed reactor test was conducted with trona as the sorbent precursor, which was calcined to sodium carbonate. In the first carbonation cycle, CO

  4. Carbon nanofibers grafted on activated carbon as an electrode in high-power supercapacitors.

    Science.gov (United States)

    Gryglewicz, Grażyna; Śliwak, Agata; Béguin, François

    2013-08-01

    A hybrid electrode material for high-power supercapacitors was fabricated by grafting carbon nanofibers (CNFs) onto the surface of powdered activated carbon (AC) through catalytic chemical vapor deposition (CCVD). A uniform thin layer of disentangled CNFs with a herringbone structure was deposited on the carbon surface through the decomposition of propane at 450 °C over an AC-supported nickel catalyst. CNF coating was controlled by the reaction time and the nickel content. The superior CNF/AC composite displays excellent electrochemical performance in a 0.5 mol L(-1) solution of K2 SO4 due to its unique structure. At a high scan rate (100 mV s(-1) ) and current loading (20 A g(-1) ), the capacitance values were three- and fourfold higher than those for classical AC/carbon black composites. Owing to this feature, a high energy of 10 Wh kg(-1) was obtained over a wide power range in neutral medium at a voltage of 0.8 V. The significant enhancement of charge propagation is attributed to the presence of herringbone CNFs, which facilitate the diffusion of ions in the electrode and play the role of electronic bridges between AC particles. An in situ coating of AC with short CNFs (below 200 nm) is a very attractive method for producing the next generation of carbon composite materials with a high power performance in supercapacitors working in neutral medium. PMID:23794416

  5. Testing metallicity indicators at z ∼ 1.4 with the gravitationally lensed galaxy CASSOWARY 20

    OpenAIRE

    James, Bethan L.; Pettini, Max; Christensen, Lise; Auger, Matthew W.; Becker, George D.; King, Lindsay J.; Quider, Anna M.; Shapley, Alice E.; Steidel, Charles C.

    2014-01-01

    We present X-shooter observations of CASSOWARY 20 (CSWA 20), a star-forming (SFR ∼ 6 M_⊙ yr^(−1)) galaxy at z = 1.433, magnified by a factor of 11.5 by the gravitational lensing produced by a massive foreground galaxy at z = 0.741. We analysed the integrated physical properties of the H ii regions of CSWA 20 using temperature- and density-sensitive emission lines. We find the abundance of oxygen to be ∼1/7 of solar, while carbon is ∼50 times less abundant than in the Sun. The unusually low C/...

  6. Carbon Deposition Model for Oxygen-Hydrocarbon Combustion, Volume 2

    Science.gov (United States)

    Hernandez, R.; Ito, J. I.; Niiya, K. Y.

    1987-01-01

    Presented are details of the design, fabrication, and testing of subscale hardware used in the evaluation of carbon deposition characteristics of liquid oxygen and three hydrocarbon fuels for both main chamber and preburner/gas generator operating conditions. In main chamber conditions, the deposition of carbon on the combustion chamber wall was investigated at mixture ratios of 2.0 to 4.0 and at chamber pressures of 1000 to 1500 psia. No carbon deposition on chamber walls was detected at these main chamber mixture ratios. In preburner/gas generator operating conditions, the deposition of carbon on the turbine simulator tubes was evaluated at mixture ratios of 0.20 to 0.60 and at chamber pressures of 720 to 1650 psia. The results of the tests showed carbon deposition rate to be a strong function of mixture ratio and a weak function of chamber pressure. Further analyses evaluated the operational concequences of carbon deposition on preburner/gas generator performance. This is Volume 2 of the report, which contains data plots of all the test programs.

  7. Carbon deposition model for oxygen-hydrocarbon combustion, volume 1

    Science.gov (United States)

    Hernandez, R.; Ito, J. I.; Niiya, K. Y.

    1987-01-01

    Presented are details of the design, fabrication, and testing of subscale hardware used in the evaluation of carbon deposition characteristics of liquid oxygen and three hydrocarbon fuels for both main chamber and preburner/gas generator operating conditions. In main chamber conditions, the deposition of carbon on the combustion chamber wall was investigated at mixture ratios of 2.0 to 4.0 and at pressures of 1000 to 1500 psia. No carbon deposition on the chamber walls was detected at these main chamber mixture ratios. In preburner/gas generator operating conditions, the deposition of carbon on the turbine simulator tubes was evaluated at mixture ratios of 0.20 to 0.60 and at chamber pressures of 720 to 1650 psia. The results of the tests showed carbon deposition rate to be a strong function of mixture ratio and a weak function of chamber pressure. Further analyses evaluated the operational consequences of carbon deposition on preburner/gas generator performance. The report is in two volumes, of which this is Volume 1 covering the main body of the report plus Appendixes A through D.

  8. Carbonate and organic carbon content changes over last 20 ka in the Southeastern Arabian Sea: Paleoceanographic implications

    Digital Repository Service at National Institute of Oceanography (India)

    Narayana, A.C.; Naidu, P.D.; Shinu, N.; Nagabhushanam, P.; Sukhija, B

    (A.C. Narayana). Contents lists available at ScienceDirect Quaternary International journal homepage: www.elsevier.com/locate/quaint 1040-6182/$ – see front matter C211 2008 Elsevier Ltd and INQUA. All rights reserved. doi:10.1016/j.quaint.2008....,1973. Physical oceanography of the Indian Ocean. In: Zeitszchel, B. (Ed.), The Biology of the Indian Ocean. Springer, New York, pp. 18–36. Yarincik, K.M., Murray, R.W., 2000. Climatically sensitive eolian and hemipelagic deposition in the Cariaco Basin...

  9. Introducing ADS 2.0

    Science.gov (United States)

    Accomazzi, Alberto; Kurtz, M. J.; Henneken, E. A.; Grant, C. S.; Thompson, D.; Luker, J.; Chyla, R.; Murray, S. S.

    2014-01-01

    In the spring of 1993, the Smithsonian/NASA Astrophysics Data System (ADS) first launched its bibliographic search system. It was known then as the ADS Abstract Service, a component of the larger Astrophysics Data System effort which had developed an interoperable data system now seen as a precursor of the Virtual Observatory. As a result of the massive technological and sociological changes in the field of scholarly communication, the ADS is now completing the most ambitious technological upgrade in its twenty-year history. Code-named ADS 2.0, the new system features: an IT platform built on web and digital library standards; a new, extensible, industrial strength search engine; a public API with various access control capabilities; a set of applications supporting search, export, visualization, analysis; a collaborative, open source development model; and enhanced indexing of content which includes the full-text of astronomy and physics publications. The changes in the ADS platform affect all aspects of the system and its operations, including: the process through which data and metadata are harvested, curated and indexed; the interface and paradigm used for searching the database; and the follow-up analysis capabilities available to the users. This poster describes the choices behind the technical overhaul of the system, the technology stack used, and the opportunities which the upgrade is providing us with, namely gains in productivity and enhancements in our system capabilities.

  10. The 20 years of PROSITE.

    Science.gov (United States)

    Hulo, Nicolas; Bairoch, Amos; Bulliard, Virginie; Cerutti, Lorenzo; Cuche, Béatrice A; de Castro, Edouard; Lachaize, Corinne; Langendijk-Genevaux, Petra S; Sigrist, Christian J A

    2008-01-01

    PROSITE consists of documentation entries describing protein domains, families and functional sites, as well as associated patterns and profiles to identify them. It is complemented by ProRule, a collection of rules based on profiles and patterns, which increases the discriminatory power of profiles and patterns by providing additional information about functionally and/or structurally critical amino acids. In this article, we describe the implementation of a new method to assign a status to pattern matches, the new PROSITE web page and a new approach to improve the specificity and sensitivity of PROSITE methods. The latest version of PROSITE (release 20.19 of 11 September 2007) contains 1319 patterns, 745 profiles and 764 ProRules. Over the past 2 years, about 200 domains have been added, and now 53% of UniProtKB/Swiss-Prot entries (release 54.2 of 11 September 2007) have a PROSITE match. PROSITE is available on the web at: http://www.expasy.org/prosite/. PMID:18003654

  11. WMS Server 2.0

    Science.gov (United States)

    Plesea, Lucian; Wood, James F.

    2012-01-01

    This software is a simple, yet flexible server of raster map products, compliant with the Open Geospatial Consortium (OGC) Web Map Service (WMS) 1.1.1 protocol. The server is a full implementation of the OGC WMS 1.1.1 as a fastCGI client and using Geospatial Data Abstraction Library (GDAL) for data access. The server can operate in a proxy mode, where all or part of the WMS requests are done on a back server. The server has explicit support for a colocated tiled WMS, including rapid response of black (no-data) requests. It generates JPEG and PNG images, including 16-bit PNG. The GDAL back-end support allows great flexibility on the data access. The server is a port to a Linux/GDAL platform from the original IRIX/IL platform. It is simpler to configure and use, and depending on the storage format used, it has better performance than other available implementations. The WMS server 2.0 is a high-performance WMS implementation due to the fastCGI architecture. The use of GDAL data back end allows for great flexibility. The configuration is relatively simple, based on a single XML file. It provides scaling and cropping, as well as blending of multiple layers based on layer transparency.

  12. Carbon Concentration of Austenite

    Directory of Open Access Journals (Sweden)

    Z. Ławrynowicz

    2007-07-01

    Full Text Available The investigation was carried out to examine the influence of temperature and times of austempering process on the maximum extend towhich the bainite reaction can proceed and the carbon content in retained austenite. It should be noted that a small percentage change in theaustenite carbon content can have a significant effect on the subsequent austempering reaction changing the volume fraction of the phasespresent and hence, the resulting mechanical properties. Specimens were prepared from an unalloyed ductile cast iron, austenitised at 950oCfor 60 minutes and austempered by the conventional single-step austempering process at four temperatures between BS and MS, eg., 250,300, 350 and 400oC. The samples were austempered at these temperatures for 15, 30, 60, 120 and 240 minutes and finally quenched toambient temperature. Volume fractions of retained austenite and carbon concentration in the residual austenite have been observed byusing X-ray diffraction. Additionally, carbon concentration in the residual austenite was calculated using volume fraction data of austeniteand a model developed by Bhadeshia based on the McLellan and Dunn quasi-chemical thermodynamic model. The comparison ofexperimental data with the T0, T0' and Ae3' phase boundaries suggests the likely mechanism of bainite reaction in cast iron is displacive rather than diffusional. The carbon concentration in retained austenite demonstrates that at the end of bainite reaction the microstructure must consist of not only ausferrite but additionally precipitated carbides.

  13. 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.

  14. Subduction of Organic Carbon into the Earth

    Science.gov (United States)

    Plank, T. A.; Malinverno, A.

    2015-12-01

    Seafloor sediments approach active subduction zones with small amounts (generally Indus and Begal Fans, Gulf of Alaska, Cascadia, etc). Together, terrigenous turbidites make up about 60% of the global subducted sediment (GLOSS), and thus have a strong control on the concentration of OC in GLOSS. Sites dominated by terrigenous turbidites have 0.4 wt% OC on average (1sd = 0.1 wt%), and GLOSS is very similar, yielding about 6 MtC/yr OC subducted globally. This flux is enough to subduct the entire surface pool of OC every 2.6 Ga, which if not returned, or returned in a more oxidized form, could contribute to a significant rise in oxygen at the surface of the Earth. Seemingly fortuitously, the OC/total carbon fraction in GLOSS is 20%, very near the long term average required to maintain the isotopic composition of marine carbonates at ~ 0 per mil d13C over much of Earth history.

  15. High Density Methane Storage in Nanoporous Carbon

    Science.gov (United States)

    Rash, Tyler; Dohnke, Elmar; Soo, Yuchoong; Maland, Brett; Doynov, Plamen; Lin, Yuyi; Pfeifer, Peter; Mriglobal Collaboration; All-Craft Team

    2014-03-01

    Development of low-pressure, high-capacity adsorbent based storage technology for natural gas (NG) as fuel for advanced transportation (flat-panel tank for NG vehicles) is necessary in order to address the temperature, pressure, weight, and volume constraints present in conventional storage methods (CNG & LNG.) Subcritical nitrogen adsorption experiments show that our nanoporous carbon hosts extended narrow channels which generate a high surface area and strong Van der Waals forces capable of increasing the density of NG into a high-density fluid. This improvement in storage density over compressed natural gas without an adsorbent occurs at ambient temperature and pressures ranging from 0-260 bar (3600 psi.) The temperature, pressure, and storage capacity of a 40 L flat-panel adsorbed NG tank filled with 20 kg of nanoporous carbon will be featured.

  16. A synthesis of carbon in international trade

    Directory of Open Access Journals (Sweden)

    G. P. Peters

    2012-03-01

    Full Text Available In a globalised world, the transfer of carbon between regions, either physically or embodied in production, represents a substantial fraction of global carbon emissions. The resulting emission transfers are important for balancing regional carbon budgets and for understanding the drivers of regional emissions. In this paper we synthesise current understanding in two parts: (1 embodied CO2 emissions from the production of goods and services produced in one country but consumed in others, (2 physical carbon flows in fossil fuels, petroleum-derived products, harvested wood products, crops, and livestock. We describe the key differences between studies and provide a consistent set of estimates using the same definitions, modelling framework, and consistent data. We find the largest trade flows of carbon in international trade in 2004 were fossil fuels (2673 MtC, 37% of global emissions, CO2 embodied in traded goods and services (1661 MtC, 22% of global emissions, livestock (651 MtC, 20% of total livestock carbon, crops (522 MtC, 31% of total harvested crop carbon, petroleum-based products (183 MtC, 50% of their total production, and harvested wood products (149 MtC, 40% of total roundwood extraction. We find that for embodied CO2 emissions estimates from independent studies are robust. We found that differences between individual studies is not representative of the uncertainty in consumption-based estimates as different studies use different production-based emission estimates as input and different definitions of allocating emissions to international trade. After adjusting for these issues, results across independent studies converge to give less uncertainty than previously assumed. For physical carbon flows there are relatively few studies to be synthesised, but differences between existing studies are due to the method of allocating to international trade with some studies using "apparent consumption" as opposed

  17. Monte Carlo simulations of hydrogen storage in carbon nanotubes

    International Nuclear Information System (INIS)

    The storage capacities of porous materials made up of carbon nanotubes are estimated by Monte Carlo simulations for the specific case of hydrogen in the pressure domain from 0.1 to 20 MPa at temperatures of 293, 150 and 77 K. The use of these materials in devices for hydrogen storage is discussed on the basis of the simulation results. (author)

  18. The U.S. beef cattle industry: The carbon footprint

    Science.gov (United States)

    This was an invited 20 minute oral presentation concerning the carbon footprint of the U.S. beef cattle industry. The audience at the workshop (about 30 people) included university professors and graduate students from agriculture and enviornmental sciences. The presentation included a brief revie...

  19. Biological effect of carbon beams on cultured human cells

    International Nuclear Information System (INIS)

    This study was performed to determine the biological effect of carbon beams on 13 human tumor cells, in comparison with 200 KVp X-rays. Carbon beams were generated by the Riken Ring Cyclotron. The RBE (relative biological effectiveness) values were distributed from 1.46 to 2.20 for LET of 20 keV/μm, and 2.29-3.54 for 80 keV/μm. The RBEs were increased in all cell lines as the LET of carbon beams was increased from 20 to 80 keV/μm. There was no significant difference in radiosensitivity between cells from adenocarcinoma and those from squamous cell carcinoma. The relationship between the radiosensitivity of cells to X-rays and RBE was analyzed, but no significant correlation was suggested. Several survival curves of 20-40 keV/μm carbon beam irradiation showed the initial shoulders and the recovery ratios between two split doses were determined. Recovery was observed for LET of 2O keV/μm but not for that of 40 keV/μm. Furthermore, recovery ratios were 1.0-1.8, smaller than those for X-rays (1.5-2.4). (author)

  20. Method for creating high carbon content products from biomass oil

    Science.gov (United States)

    Parker, Reginald; Seames, Wayne

    2012-12-18

    In a method for producing high carbon content products from biomass, a biomass oil is added to a cracking reactor vessel. The biomass oil is heated to a temperature ranging from about 100.degree. C. to about 800.degree. C. at a pressure ranging from about vacuum conditions to about 20,700 kPa for a time sufficient to crack the biomass oil. Tar is separated from the cracked biomass oil. The tar is heated to a temperature ranging from about 200.degree. C. to about 1500.degree. C. at a pressure ranging from about vacuum conditions to about 20,700 kPa for a time sufficient to reduce the tar to a high carbon content product containing at least about 50% carbon by weight.

  1. Food sources and carbon dudget of chinese prawn Penaeus chinensis

    Science.gov (United States)

    Dong, Shuang-Lin; Zhang, Shuo; Wang, Fang

    2002-03-01

    This study deals with contribution of artificial food pellet and natural food to Chinese prawn ( Penaeus orientalis) growth in a semi-intensive culture pond. The prawn carbon consumption, budget, and the effects of some factors on the budget were investigated. The results showed that 26.2% of P. orientalis growth carbon came from formulated feed at the initial culture stage (when the prawns were 0.06±0.01 g in wet weight), and was 62.5% when the prawns were 9.56±1.04 g. The remaining part of the growth carbon was derived from organic fertilizer and natural food. The highest growth rate occurred at 20×10-3 salinity. Suitable salinity for culturing Chinese prawn was (20 28)×10-3.

  2. FOOD SOURCES AND CARBON BUDGET OF CHINESE PRAWN PENAEUS CHINENSIS

    Institute of Scientific and Technical Information of China (English)

    董双林; 张硕; 王芳

    2002-01-01

    This study deals with contribution of artificial food pellet and natural food to Chinese prawn (Penaeus orientalis) growth in a semiintensive culture pond. The prawn carbon consumption, budget, and the effects of some factors on the budget were investigated. The results showed that 26.2% of P. orientalis growth carbon came from formulated feed at the initial culture stage (when the prawns were 0.06±0.01 g in wet weight), and was 62.5% when the prawns were 9.56±1.04 g. The remaining part of the growth carbon was derived from organic fertilizer and natural food. The highest growth rate occurred at 20×10-3 salinity. Suitable salinity for culturing Chinese prawn was (20-28)×10-3.

  3. 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

    CH2M HILL Plateau Remediation Company (CHPRC) is currently developing a 200-West Area groundwater pump-and-treat system as the remedial action selected under the Comprehensive Environmental Response, Compensation, and Liability Act Record of Decision for Operable Unit (OU) 200-ZP-1. This report documents the results of treatability tests Pacific Northwest National Laboratory researchers conducted to quantify the ability of selected activated carbon products (or carbons) to adsorb technetium-99 (Tc-99) from 200-West Area groundwater. The Tc-99 adsorption performance of seven activated carbons (J177601 Calgon Fitrasorb 400, J177606 Siemens AC1230AWC, J177609 Carbon Resources CR-1240-AW, J177611 General Carbon GC20X50, J177612 Norit GAC830, J177613 Norit GAC830, and J177617 Nucon LW1230) were evaluated using water from well 299-W19-36. Four of the best performing carbons (J177606 Siemens AC1230AWC, J177609 Carbon Resources CR-1240-AW, J177611 General Carbon GC20X50, and J177613 Norit GAC830) were selected for batch isotherm testing. The batch isotherm tests on four of the selected carbons indicated that under lower nitrate concentration conditions (382 mg/L), Kd values ranged from 6,000 to 20,000 mL/g. In comparison. Under higher nitrate (750 mg/L) conditions, there was a measureable decrease in Tc-99 adsorption with Kd values ranging from 3,000 to 7,000 mL/g. The adsorption data fit both the Langmuir and the Freundlich equations. Supplemental tests were conducted using the two carbons that demonstrated the highest adsorption capacity to resolve the issue of the best fit isotherm. These tests indicated that Langmuir isotherms provided the best fit for Tc-99 adsorption under low nitrate concentration conditions. At the design basis concentration of Tc 0.865 µg/L(14,700 pCi/L), the predicted Kd values from using Langmuir isotherm constants were 5,980 mL/g and 6,870 mL/g for for the two carbons. These Kd values did not meet the target Kd value of 9,000 mL/g. Tests

  4. Modelling the carbon and nitrogen balances of direct land use changes from energy crops in Denmark

    DEFF Research Database (Denmark)

    Hamelin, Lorie; Jørgensen, Uffe; Petersen, Bjørn Molt;

    2012-01-01

    and perennials), two soil types (sandy loam and sand), two climate types (wet and dry), three initial soil carbon level (high, average, low), two time horizons for soil carbon changes (20 and 100 years), two residues management practices (removal and incorporation into soil) as well as three soil...... carbon turnover rate reductions in response to the absence of tillage for some perennial crops (0%, 25%, 50%). For all crop systems, nutrient balances, balances between above- and below-ground residues, soil carbon changes, biogenic carbon dioxide flows, emissions of nitrogen compounds and losses of...... macro- and micronutrients are presented. The inventory results highlight Miscanthus as a promising energy crop, indicating it presents the lowest emissions of nitrogen compounds, the highest amount of carbon dioxide sequestrated from the atmosphere, a relatively high carbon turnover efficiency and...

  5. Carbon exchange between ecosystems and atmosphere in the Czech Republic is affected by climate factors.

    Science.gov (United States)

    Marek, Michal V; Janouš, Dalibor; Taufarová, Klára; Havránková, Kateřina; Pavelka, Marian; Kaplan, Věroslav; Marková, Irena

    2011-05-01

    By comparing five ecosystem types in the Czech Republic over several years, we recorded the highest carbon sequestration potential in an evergreen Norway spruce forest (100%) and an agroecosystem (65%), followed by European beech forest (25%) and a wetland ecosystem (20%). Because of a massive ecosystem respiration, the final carbon gain of the grassland was negative. Climate was shown to be an important factor of carbon uptake by ecosystems: by varying the growing season length (a 22-d longer season in 2005 than in 2007 increased carbon sink by 13%) or by the effect of short- term synoptic situations (e.g. summer hot and dry days reduced net carbon storage by 58% relative to hot and wet days). Carbon uptake is strongly affected by the ontogeny and a production strategy which is demonstrated by the comparison of seasonal course of carbon uptake between coniferous (Norway spruce) and deciduous (European beech) stands. PMID:21345558

  6. Measurement of the activity coefficient of carbon in steels in liquid sodium

    International Nuclear Information System (INIS)

    In sodium cooled fast reactors carbon is both a carbon impurity and element of structural materials. Carbon transfert through liquid sodium can produce carburization or decarburization of structural materials. Carbon content in sodium is determined with thin foils of austenitic alloys, when equilibrium is reached thermodynamic activity of carbon in sodium is deduced from carbon activity in alloys. Studied alloys are FeMn 20%, FeNi 30%, Z2CN 18-10 and Z3CND17-13. Carbon activity of alloys in sodium was between 5.10-3 and 10-1 at 600 and 6500C. Calibration was obtained with the alloys FeNi 30% in gaseous mixtures He-CO-CO2 of known activity

  7. The Carbon Trading Game

    International Nuclear Information System (INIS)

    In response to the Kyoto Protocol, an international market for carbon dioxide tradable permits is likely to be created. Two of the key issues involved are explaining the concepts of tradable permits to industrialists, policy-makers and the man on the street, and anticipating how the market will evolve. A simple game of the market for carbon dioxide tradable permits has been developed and used that can help deal with both issues. As a pedagogical tool, this game benefits from simplicity (just a few pieces of paper are needed) and enables students to grasp the concepts and remember them through the intensity and fun of a trading 'pit'. The experiences also provide substantial insights into the evolution of the carbon dioxide permit market, particularly related to the evolution of trade volume, permit prices and country strategies

  8. 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

  9. 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...... to the surface where the beam enters) are examined. For each plan the minimum,  maximum and the dose averaged LET of the PTV is calculated. The numbers are translated to OER using several sets of data found in literature for various cell lines. Results: We find a strong dependence of the dose average LET and OER...... 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....

  10. Carbon Nanotubes for Supercapacitor

    Directory of Open Access Journals (Sweden)

    Li Jianyi

    2010-01-01

    Full Text Available Abstract As an electrical energy storage device, supercapacitor finds attractive applications in consumer electronic products and alternative power source due to its higher energy density, fast discharge/charge time, low level of heating, safety, long-term operation stability, and no disposable parts. This work reviews the recent development of supercapacitor based on carbon nanotubes (CNTs and their composites. The purpose is to give a comprehensive understanding of the advantages and disadvantages of carbon nanotubes-related supercapacitor materials and to find ways for the improvement in the performance of supercapacitor. We first discussed the effects of physical and chemical properties of pure carbon nanotubes, including size, purity, defect, shape, functionalization, and annealing, on the supercapacitance. The composites, including CNTs/oxide and CNTs/polymer, were further discussed to enhance the supercapacitance and keep the stability of the supercapacitor by optimally engineering the composition, particle size, and coverage.

  11. Earth system responses to cumulative carbon emissions

    Science.gov (United States)

    Steinacher, M.; Joos, F.

    2015-07-01

    Information on the relationship between cumulative fossil carbon emissions and multiple climate targets are essential to design emission mitigation and climate adaptation strategies. In this study, the transient responses in different climate variables are quantified for a large set of multi-forcing scenarios extended to year 2300 towards stabilization and in idealized experiments using the Bern3D-LPJ carbon-climate model. The model outcomes are constrained by 26 physical and biogeochemical observational data sets in a Bayesian, Monte-Carlo type framework. Cumulative fossil emissions of 1000 Gt C result in a global mean surface air temperature change of 1.88 °C (68 % confidence interval (c.i.): 1.28 to 2.69 °C), a decrease in surface ocean pH of 0.19 (0.18 to 0.22), and in steric sea level rise of 20 cm (13 to 27 cm until 2300). Linearity between cumulative emissions and transient response is high for pH and reasonably high for surface air and sea surface temperatures, but less pronounced for changes in Atlantic Meridional Overturning, Southern Ocean and tropical surface water saturation with respect to biogenic structures of calcium carbonate, and carbon stocks in soils. The slopes of the relationships change when CO2 is stabilized. The Transient Climate Response is constrained, primarily by long-term ocean heat observations, to 1.7 °C (68 % c.i.: 1.3 to 2.2 °C) and the Equilibrium Climate Sensitivity to 2.9 °C (2.0 to 4.2 °C). This is consistent with results by CMIP5 models, but inconsistent with recent studies that relied on short-term air temperature data affected by natural climate variability.

  12. Earth system responses to cumulative carbon emissions

    Directory of Open Access Journals (Sweden)

    M. Steinacher

    2015-07-01

    Full Text Available Information on the relationship between cumulative fossil carbon emissions and multiple climate targets are essential to design emission mitigation and climate adaptation strategies. In this study, the transient responses in different climate variables are quantified for a large set of multi-forcing scenarios extended to year 2300 towards stabilization and in idealized experiments using the Bern3D-LPJ carbon-climate model. The model outcomes are constrained by 26 physical and biogeochemical observational data sets in a Bayesian, Monte-Carlo type framework. Cumulative fossil emissions of 1000 Gt C result in a global mean surface air temperature change of 1.88 °C (68 % confidence interval (c.i.: 1.28 to 2.69 °C, a decrease in surface ocean pH of 0.19 (0.18 to 0.22, and in steric sea level rise of 20 cm (13 to 27 cm until 2300. Linearity between cumulative emissions and transient response is high for pH and reasonably high for surface air and sea surface temperatures, but less pronounced for changes in Atlantic Meridional Overturning, Southern Ocean and tropical surface water saturation with respect to biogenic structures of calcium carbonate, and carbon stocks in soils. The slopes of the relationships change when CO2 is stabilized. The Transient Climate Response is constrained, primarily by long-term ocean heat observations, to 1.7 °C (68 % c.i.: 1.3 to 2.2 °C and the Equilibrium Climate Sensitivity to 2.9 °C (2.0 to 4.2 °C. This is consistent with results by CMIP5 models, but inconsistent with recent studies that relied on short-term air temperature data affected by natural climate variability.

  13. The thermal properties of amorphous Fe40Pd40B20 and Fe60Pd20B20 thin films

    International Nuclear Information System (INIS)

    The thermal stability of FePdB thin films was studied using nonisothermal and isothermal analyses. X-ray diffraction (XRD) patterns indicated that Fe40Pd40B20 and Fe60Pd20B20 films with thicknesses in the range 25–75 Å were amorphous, whereas Fe40Pd40B20 and Fe60Pd20B20 films with thicknesses in the range 100–200 Å exhibited a nanocrystalline FePd (111) structure. The crucial glass forming ability index (γ and γm) was determined using the differential scanning calorimetry (DSC) results of amorphous FePdB films. The Kissinger formula was applied to calculate the activation energy (Q) of crystallization for determining the resistance of the films to crystallization. Thermal analysis showed that the thermal stability and incubation time of Fe40Pd40B20 are more favorable than those of Fe60Pd20B20. - Highlights: • FePdB films were amorphous in the range 25–75 Å. • FePdB films exhibited a FePd (111) structure in the range 100–200 Å. • The crucial glass forming ability index was determined using the DSC. • Kissinger formula was applied to calculate the activation energy of crystallization. • The thermal performance of Fe40Pd40B20 is more favorable than Fe60Pd20B20

  14. CI, CII, and CO as tracers of gas phase carbon

    Science.gov (United States)

    Keene, Jocelyn

    1990-01-01

    In the dense interstellar medium, we find that about 20 percent of the total carbon abundance is in the form of CO, about 3 percent in C(sub I), and 100 percent in C(sub II) with uncertainties of factors of order 2. The abundance of other forms of gaseous carbon is negligible. CO is widespread throughout molecular clouds as is C(sub I). C(sub II) has only been observed near bright star-formation regions so far because of its high excitation energy. Further from ultraviolet sources it may be less abundant. Altogether we have accounted for about 1/3 of the total carbon abundance associated with dense molecular clouds. Since the other gaseous forms are thought to have negligible abundances, the rest of the carbon is probably in solid form.

  15. Ion-exchange behavior of alkali metals on treated carbons

    International Nuclear Information System (INIS)

    The ion-exchange behavior of trace quantities of the alkali-metal ions sodium and cesium, on activated carbon impregnated with zirconium phosphate (referred to here as ZrP), was studied. Impregnated carbon had twice as much ion-exchange activity as unimpregnated, oxidized carbon, and 10 times as much as commercial activated carbons. The distribution coefficient of sodium increased with increasing pH; the distribution coefficient of cesium decreased with increasing pH. Sodium and cesium were separated with an electrolytic solution of 0.1 M HCl. Preliminary studies indicated that 0.2 M potassium and cesium can also be separated. Distribution coefficients of the supported ZrP were determined by the elution technique and agreed within 20% of the values for pure ZrP calculated from the literature

  16. Preparation of carbon-free TEM microgrids by metal sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Janbroers, S., E-mail: stephan.janbroers@albemarle.com [Albemarle Catalysts B.V., Nieuwendammerkade 1-3, 1030 BE, Amsterdam (Netherlands); Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands); Kruijff, T.R. de; Xu, Q. [Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands); Kooyman, P.J. [DelftChemTech, Delft University of Technology, Julianalaan 136, 2628 BL, Delft (Netherlands); Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands); Zandbergen, H.W. [Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands)

    2009-08-15

    A new method for preparing carbon-free, temperature-stable Transmission Electron Microscope (TEM) grids is presented. An 80% Au/20% Pd metal film is deposited onto a 'holey' microgrid carbon supported on standard mixed-mesh Au TEM grids. Subsequently, the carbon film is selectively removed using plasma cleaning. In this way, an all-metal TEM film is made containing the 'same' microgrid as the original carbon film. Although electron transparency of the foil is reduced significantly, the open areas for TEM inspection of material over these areas are maintained. The metal foil can be prepared with various thicknesses and ensures good electrical conductivity. The new Au/Pd grids are stable to at least 775 K under vacuum conditions.

  17. Preparation of carbon-free TEM microgrids by metal sputtering

    International Nuclear Information System (INIS)

    A new method for preparing carbon-free, temperature-stable Transmission Electron Microscope (TEM) grids is presented. An 80% Au/20% Pd metal film is deposited onto a 'holey' microgrid carbon supported on standard mixed-mesh Au TEM grids. Subsequently, the carbon film is selectively removed using plasma cleaning. In this way, an all-metal TEM film is made containing the 'same' microgrid as the original carbon film. Although electron transparency of the foil is reduced significantly, the open areas for TEM inspection of material over these areas are maintained. The metal foil can be prepared with various thicknesses and ensures good electrical conductivity. The new Au/Pd grids are stable to at least 775 K under vacuum conditions.

  18. Preparation of carbon-free TEM microgrids by metal sputtering.

    Science.gov (United States)

    Janbroers, S; de Kruijff, T R; Xu, Q; Kooyman, P J; Zandbergen, H W

    2009-08-01

    A new method for preparing carbon-free, temperature-stable Transmission Electron Microscope (TEM) grids is presented. An 80% Au/20% Pd metal film is deposited onto a 'holey' microgrid carbon supported on standard mixed-mesh Au TEM grids. Subsequently, the carbon film is selectively removed using plasma cleaning. In this way, an all-metal TEM film is made containing the 'same' microgrid as the original carbon film. Although electron transparency of the foil is reduced significantly, the open areas for TEM inspection of material over these areas are maintained. The metal foil can be prepared with various thicknesses and ensures good electrical conductivity. The new Au/Pd grids are stable to at least 775K under vacuum conditions. PMID:19450927

  19. 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

  20. 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...

  1. Deposition of carbon dioxide

    International Nuclear Information System (INIS)

    In Norway, there is currently a debate about whether or not to build gas power stations. To meet the possibility of reduced emission quotas for carbon dioxide in the future, current interest focuses on the incorporation of large-scale separation and deposition of carbon dioxide when such plants are planned. A group of experts concludes that this technology will become self-financing by means of environmental taxes. From the environmental point of view, taxes upon production are to be preferred over taxes on consumption

  2. 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.

  3. 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.

  4. 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....

  5. Climate constraints on the carbon intensity of economic growth

    International Nuclear Information System (INIS)

    Development and climate goals together constrain the carbon intensity of production. Using a simple and transparent model that represents committed CO2 emissions (future emissions expected to come from existing capital), we explore the carbon intensity of production related to new capital required for different temperature targets across several thousand scenarios. Future pathways consistent with the 2 °C target which allow for continued gross domestic product growth require early action to reduce carbon intensity of new production, and either (i) a short lifetime of energy and industry capital (e.g. early retrofit of coal power plants), or (ii) large negative emissions after 2050 (i.e. rapid development and dissemination of carbon capture and sequestration). To achieve the 2 °C target, half of the scenarios indicate a carbon intensity of new production between 33 and 73 g CO2/$—much lower than the global average today, at 360 g CO2/$. The average lifespan of energy capital (especially power plants), and industry capital, are critical because they commit emissions far into the future and reduce the budget for new capital emissions. Each year of lifetime added to existing, carbon intensive capital, decreases the carbon intensity of new production required to meet a 2 °C carbon budget by 1.0–1.5 g CO2/$, and each year of delaying the start of mitigation decreases the required CO2 intensity of new production by 20–50 g CO2/$. Constraints on the carbon intensity of new production under a 3 °C target are considerably relaxed relative to the 2 °C target, but remain daunting in comparison to the carbon intensity of the global economy today. (letter)

  6. Blue carbon for how long? Lability of buried salt marsh carbon released via erosion.

    Science.gov (United States)

    Cox, D.; Currin, C.; Mctigue, N.

    2015-12-01

    With our climate rapidly changing due to increasing greenhouse gas emissions, the ability of coastal wetlands to sequester carbon (C) on century to millennial time scales has bolstered new interest in these habitats. This stored sedimentary organic carbon termed "blue C" can be eroded to surface horizons from the impacts of sea level rise, storm events, or other physical modifications of the coastline, potentially returning CO2 to the atmosphere upon microbially mediated remineralization. The rates and extent of these remineralization processes are largely unknown. A field exercise revealed a horizontal gradient in the organic matter content of marsh sediments perpendicular to creek banks, as proximity to tidal creeks resulted in a decline in sediment C content, with some variation due to creekbank morphology. We also conducted lab experiments to test the effect of temperature, as in some systems it has been found that a 1°C increase in temperature increases organic matter decomposition rates by 20%. In this study, fluxes of dissolved inorganic carbon (DIC), pH, and pCO2 were measured to determine carbon remineralization rates of marsh sediment collected 30 cm below the surface. A 20°C and 30°C temperature treatment was instituted to examine Q10 and activation energy of the decomposition processes that could potentially act as a climate change positive feedback upon erosion of blue carbon. Laboratory results show that the century-old blue carbon overall is refractory to tidal creek microbes, as only a maximum of 0.28% of sediment organic C was respired in two-week incubations. However, the remineralization rate exhibited a Q10 of 2.45, indicating that the organic carbon, despite being refractory, is temperature sensitive and will degrade exponentially if exposed to higher temperatures. These rates were then modeled at current and projected temperature profiles and applied to actual erosion rates in the study site to assess the release of carbon dioxide via

  7. CarbonSat Constellation

    Science.gov (United States)

    Sun, Wei; Tobehn, Carsten; Ernst, Robert; Bovensmann, Heinrich; Buchwitz, Michael; Burrows, John P.; Notholt, John

    1 Carbon dioxide (CO2) and methane (CH4) are the most important manmade greenhouse gases (GHGs) which are driving global climate change. Currently, the CO2 measurements from the ground observing network are still the main sources of information but due to the limited number of measurement stations the coverage is limited. In addition, CO2 monitoring and trading is often based mainly on bottom-up calculations and an independent top down verification is limited due to the lack of global measurement data with local resolution. The first CO2 and CH4 mapping from SCIAMACHY on ENVISAT shows that satellites add important missing global information. Current GHG measurement satellites (GOSAT)are limited either in spatial or temporal resolution and coverage. These systems have to collect data over a year or even longer to produce global regional fluxes products. Conse-quently global, timely, higher spatial resolution and high accuracy measurement are required for: 1. A good understanding of the CO2 and CH4 sources and sinks for reliable climate predic-tion; and 2. Independent and transparent verification of accountable sources and sinks in supporting Kyoto and upcoming protocols The CarbonSat constellation idea comes out the trade off of resolution and swath width during CarbonSat mission definition studies. In response to the urgent need to support the Kyoto and upcoming protocols, a feasibility study has been carried out. The proposed solution is a constellation of five CarbonSat satellites in 614km LTAN 13:00, which is able to provide global, daily CO2 and CH4 measurement everywhere on the Earth with high spatial resolution 2 × 2 km and low uncertainty lt;2ppm (CO2) and lt;8ppb (CH4). The unique global daily measurement capability significantly increases the number of cloud free measurements, which enables more reliable services associated with reduced uncertainty, e.g. to 0.15ppm (CO2) per month in 10km and even more timely products. The CarbonSat Constellation in

  8. Cardiovascular deaths related to Carbon monoxide Exposure in Ahvaz, Iran

    Directory of Open Access Journals (Sweden)

    Gholamreza Goudarzi

    2014-08-01

    Full Text Available Carbon monoxide is an odorless, colorless and toxic gas that emitted from combustion. Carbon monoxide can cause harmful health effects by reducing oxygen delivery to the body's organs (like the heart and brain, tissues, fibrinolysis effects, abortion and death at extremely high levels. The aim of this study was to assess health- effects of carbon monoxide exposure in Ahvaz city. Data were collected through Ahvaz Meteorological Organization and Department of Environment. Raw data processing by Excel software includes (instruction set correction of averaging, coding and filtering and after the impact of meteorological parameters was converted as input file to the Air Q model. Finally, health-effects of carbon monoxide exposure were calculated. The results showed that the concentration of carbon monoxide was 7.41 mg/m3 in Ahvaz as annual average. Sum of total numbers of deaths attributed to carbon monoxide was 16 cases within a year. Approximately 4.3% of total Cardiovascular deaths happened when the carbon monoxide concentrations was more than 20 mg/m3. This could be due to higher fuel consumption gasoline in vehicles, Oil industry, steel and Heavy industries in Ahwaz. Mortality and Morbidity risks were detected at current ambient concentrations of air pollutants.

  9. Carbonation rates of concretes containing high volume of pozzolanic materials

    Energy Technology Data Exchange (ETDEWEB)

    Kritsada Sisomphon; Lutz Franke [Technical University Hamburg-Harburg, Hamburg (Germany). Department of Building Physics and Building Materials

    2007-12-15

    The project studies the influence of fly ash and slag replacement on the carbonation rate of the concrete. The experimental work includes samples of pure Portland cement concrete (CEM I 42,5 R), blast-furnace slag concrete (CEM III-B), and fly ash blended concrete. To reveal the effect of curing on carbonation rate, the concretes were exposed to various submerged curing periods during their early ages. After that, the samples were subsequently exposed in the climate room controlling 20 {sup o}C and 50% RH until the testing date when the samples had an age of 5 months. Then, the accelerated carbonation test controlling the carbon dioxide concentration of 3% by volume, with 65% relative humidity were started to perform. The depth of carbonation can be observed by spraying a phenolphthalein solution on the fresh broken concrete surface. Finally, according to Fick's law of diffusion theoretical equations are proposed as a guide for estimating the carbonation rate of fly ash and blast-furnace slag concretes exposed under natural conditions from the results from accelerated carbonation tests.

  10. Policy options for carbon taxation in the EU

    OpenAIRE

    Eloi Laurent; Jacques Le Cacheux

    2010-01-01

    Even though the EU clearly leads the global fight against climate change and despite the additional reduction in emissions due to the global crisis and European recession, the ambitious objectives flagged in the "20-20-20 by 2020" strategy and 'climate-energy package' are probably out of reach if a more resolute and consistent policy of carbon taxation is not rapidly put in place. First, the EU is not as 'virtuous' as it may seem, and shows signs of a 'fatigue' in mitigating climate change; t...

  11. Policy options for carbon taxation in the EU

    OpenAIRE

    Laurent, Eloi; Le Cacheux, Jacques

    2010-01-01

    Even though the EU clearly leads the global fight against climate change and despite the additional reduction in emissions due to the global crisis and European recession, the ambitious objectives flagged in the “20-20-20 by 2020” strategy and ‘climate-energy package’ are probably out of reach if a more resolute and consistent policy of carbon taxation is not rapidly put in place. First, the EU is not as ‘virtuous’ as it may seem, and shows signs of a ‘fatigue’ in mitigating cl...

  12. In situ functionalisation of mesoporous carbon electrodes with carbon nanotubes for proton exchange membrane fuel-cell application

    Energy Technology Data Exchange (ETDEWEB)

    Samiee, Leila, E-mail: Leila.samiee83@gmail.com; Shoghi, Fatemeh; Maghsodi, Akram

    2014-02-14

    In the work presented here, an attempt is made to study the effect of different carbon supports on the mesostructural properties as well as electrochemical behaviour of Pt/carbon supports. In this respect, the functionalised samples have been synthesised by using CMK-3, nickelocene as nickel source and the chemical vapour deposition (CVD) process for growth of carbon nanotubes. The platinum catalysts (Pt 20 wt.%) were obtained through a conventional wet impregnation method. All the materials have been characterised by XRD (small- and high-) angle, N{sub 2} adsorption–desorption isotherms, high-resolution transmission electron microscopy and high-resolution field emission scanning electron microscopy. The results showed that the mesostructural structure had been partially destroyed by functionalisation of CMK-3 with NiO and multiwalled carbon nanotubes (MWCNTs). Moreover, wide-angle X-ray diffraction (WAXRD) studies revealed the formation of smaller platinum crystallite sizes compared to Vulcan-supported samples. Furthermore, electrochemical evaluation indicates that CMK-3–CNT–20Pt gives a specific surface area of 58.9 m{sup 2} g{sup −1}. Finally, the polarisation curves for the fabricated membrane electrode assemblies (MEAs) with Pt loading of 0.5 mg cm{sup −2} demonstrated that the CMK-3–CNT–20Pt catalyst shows better performance than industrial catalysts and even Vulcan–40% Pt. - Highlights: • In situ functionalisation of ordered mesoporous carbon with carbon nanotubes. • Novel electrocatalytic activity of functionalised mesostructured carbon. • Simultaneous effect of surface area and reactivity on electrocatalytic activity.

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

    Science.gov (United States)

    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.

  14. Hybrid Composites Based on Carbon Fiber/Carbon Nanofilament Reinforcement

    OpenAIRE

    Mehran Tehrani; Ayoub Yari Boroujeni; Claudia Luhrs; Jonathan Phillips; Al-Haik, Marwan S.

    2014-01-01

    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 emplo...

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

    International Nuclear Information System (INIS)

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

  16. Method to coat carbon or graphite bodies

    International Nuclear Information System (INIS)

    Carbon or graphite bodies are coated by embedding them in a powder mixture (grain size 20-150 μm) of the coating metal (silicon or transition metals of the 4th-8th group), inert substances (oxide, nitride or carbide of Si, Ca, Mg, Al, Ti, Zr, Hf) and a volatile metal halide (preferably ZnCl2) and are heated to 800-12000C. The method is explained by means of various examples (e.g. zirconium coating of graphitic pipes for reactor purposes). (IHOE)

  17. Sorption of UO22+ on calcium carbonate

    International Nuclear Information System (INIS)

    Sorption of uranyl ions on calcium carbonate from aqueous solutions featuring different concentration of calcium nitrate was studied experimentally. It is shown that uranium sorption decreases with calcium concentration growth in solution, irrespective of the ratio of solid phase and solution masses. Specific sorption of uranium per unit of the sorbent surface depends linearly on the ratio of UO22+ and Ca2+ ions activities in solution with proportionality factor (sorption equilibrium constant) 1.71 ± 0.16 mol/m2 at 20 deg C

  18. Spin transport in ferromagnetically contacted carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, C.; Morgan, C.; Schneider, C.M. [Peter Gruenberg Institut, PGI-6, Forschungszentrum Juelich and JARA Juelich Aachen Research Alliance, 52425 Juelich (Germany)

    2011-11-15

    We present magnetoresistance (MR) measurements on carbon nanotubes (CNTs) with different ferromagnetic leads. A sample with permalloy (Ni{sub 80}Fe{sub 20}) contacts shows the expected tunneling-type MR effect. Measurements on devices with CoPd contacts show a larger change of resistance with magnetic field. However, only minor loops are observed, which is explained with domain wall pinning. This is supported by magnetic force microscopy (MFM) measurements, which reveal a complicated bubble and stripe domain pattern. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Cortical blindness in acute carbon monoxide poisoning.

    Science.gov (United States)

    Katafuchi, Y; Nishimi, T; Yamaguchi, Y; Matsuishi, T; Kimura, Y; Otaki, E; Yamashita, Y

    1985-01-01

    A 3-year-old boy had persistent cortical blindness following acute carbon monoxide poisoning. He was believed to have suffered anoxic brain damage due to incomplete combustion of the briquette-type solid fuel. Computed tomographic (CT) scan of the brain and visual evoked potentials (VEP) in the early stage were normal. However, on the 20th hospital day CT scan showed leukomalacia and VEP showed an absence of N1-, and P1-waves which was well correlated with the clinical feature at that time. PMID:4083389

  20. Redox Control of 20S Proteasome Gating

    OpenAIRE

    Silva, Gustavo M.; Netto, Luis E. S.; Simões, Vanessa; Santos, Luiz F.A.; Gozzo, Fabio C.; Demasi, Marcos A.A.; de Oliveira, Cristiano L P; Renata N. Bicev; Klitzke, Clécio F.; Sogayar, Mari C; Demasi, Marilene

    2012-01-01

    The proteasome is the primary contributor in intracellular proteolysis. Oxidized or unstructured proteins can be degraded via a ubiquitin- and ATP-independent process by the free 20S proteasome (20SPT). The mechanism by which these proteins enter the catalytic chamber is not understood thus far, although the 20SPT gating conformation is considered to be an important barrier to allowing proteins free entrance. We have previously shown that S-glutathiolation of the 20SPT is a post-translational...

  1. Carbon diffusion in carbon-supersaturated ferrite and austenite

    Czech Academy of Sciences Publication Activity Database

    Čermák, Jiří; Král, Lubomír

    2014-01-01

    Roč. 586, FEB (2014), s. 129-135. ISSN 0925-8388 R&D Projects: GA ČR(CZ) GAP108/11/0148; GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 Keywords : carbon diffusion * Carbon supersaturation * Carbon supersaturation * Ferrite * Austenite Subject RIV: BJ - Thermodynamics Impact factor: 2.999, year: 2014

  2. Web 2.0 Solutions to Wicked Climate Change Problems

    Directory of Open Access Journals (Sweden)

    Alanah Kazlauskas

    2010-01-01

    Full Text Available One of the most pressing ‘wicked problems’ facing humankind is climate change together with its many interrelated environmental concerns. The complexity of this set of problems can be overwhelming as there is such diversity among both the interpretations of the scientific evidence and the viability of possible solutions. Among the social technologies associated with the second generation of the Internet known as Web 2.0, there are tools that allow people to communicate, coordinate and collaborate in ways that reduce their carbon footprint and a potential to become part of the climate change solution. However the way forward is not obvious or easy as Web 2.0, while readily accepted in the chaotic social world, is often treated with suspicion in the more ordered world of business and government. This paper applies a holistic theoretical sense-making framework to research and practice on potential Web 2.0 solutions to climate change problems. The suite of issues, activities and tools involved are viewed as an ecosystem where all elements are dynamic and inter-related. Through such innovative thinking the Information Systems community can make a valuable contribution to a critical global problem and hence find a new relevance as part of the solution.

  3. 26 CFR 20.0-1 - Introduction.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 14 2010-04-01 2010-04-01 false Introduction. 20.0-1 Section 20.0-1 Internal...; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Introduction § 20.0-1 Introduction. (a) In general. (1... administration provisions. Subtitle F of the Internal Revenue Code contains some sections which are applicable...

  4. 45 CFR 1308.20 - Nutrition services.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Nutrition services. 1308.20 Section 1308.20 Public... PROGRAM HEAD START PROGRAM PERFORMANCE STANDARDS ON SERVICES FOR CHILDREN WITH DISABILITIES Nutrition Performance Standards § 1308.20 Nutrition services. (a) The disabilities coordinator must work with staff...

  5. 27 CFR 20.101 - Drafting formulas.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Drafting formulas. 20.101 Section 20.101 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... Process Approval Policies § 20.101 Drafting formulas. (a) In preparing Form 5150.19, the...

  6. 7 CFR 20.2 - Administration.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Administration. 20.2 Section 20.2 Agriculture Office of the Secretary of Agriculture EXPORT SALES REPORTING REQUIREMENTS § 20.2 Administration. The regulations of this part will be administered by the Foreign Agricultural Service (FAS) under the...

  7. 32 CFR 776.20 - Competence.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Competence. 776.20 Section 776.20 National... Professional Conduct § 776.20 Competence. (a) Competence. A covered attorney shall provide competent, diligent.... Initial determinations as to competence of a covered USG attorney for a particular assignment shall...

  8. 25 CFR 211.20 - Leasing procedures.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Leasing procedures. 211.20 Section 211.20 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF TRIBAL LANDS FOR MINERAL DEVELOPMENT How To Acquire Leases § 211.20 Leasing procedures. (a) Indian mineral owners may, with...

  9. 25 CFR 212.20 - Leasing procedures.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Leasing procedures. 212.20 Section 212.20 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF ALLOTTED LANDS FOR MINERAL DEVELOPMENT How To Acquire Leases § 212.20 Leasing procedures. (a) Application for leases shall...

  10. 36 CFR 1275.20 - Responsibility.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Responsibility. 1275.20 Section 1275.20 Parks, Forests, and Public Property NATIONAL ARCHIVES AND RECORDS ADMINISTRATION NIXON... THE NIXON ADMINISTRATION Preservation and Protection § 1275.20 Responsibility. The Archivist...

  11. 21 CFR 606.20 - Personnel.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Personnel. 606.20 Section 606.20 Food and Drugs... GOOD MANUFACTURING PRACTICE FOR BLOOD AND BLOOD COMPONENTS Organization and Personnel § 606.20 Personnel. (a) (b) The personnel responsible for the collection, processing, compatibility testing,...

  12. 50 CFR 20.155 - Public file.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Public file. 20.155 Section 20.155... § 20.155 Public file. (a) Establishment. A public file will be established for each rulemaking to which.... 552, a public file established pursuant to paragraph (a) of this section will contain: (1) The...

  13. 27 CFR 20.91 - Formula.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Formula. 20.91 Section 20... TREASURY LIQUORS DISTRIBUTION AND USE OF DENATURED ALCOHOL AND RUM Formulas and Statements of Process § 20.91 Formula. (a) Each article made with specially denatured spirits shall be made in accordance...

  14. 42 CFR 410.20 - Physicians' services.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Physicians' services. 410.20 Section 410.20 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICARE PROGRAM SUPPLEMENTARY MEDICAL INSURANCE (SMI) BENEFITS Medical and Other Health Services § 410.20 Physicians'...

  15. 50 CFR 635.20 - Size limits.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Size limits. 635.20 Section 635.20..., DEPARTMENT OF COMMERCE ATLANTIC HIGHLY MIGRATORY SPECIES Management Measures § 635.20 Size limits. Link to an... (160 cm), LJFL. (4) The Atlantic blue and white marlin minimum size limits, specified in paragraphs...

  16. 50 CFR 20.61 - Importation limits.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Importation limits. 20.61 Section 20.61... PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Importations § 20.61 Importation limits. No person shall import migratory game birds in excess of the following importation limits: (a) Doves and pigeons. (1) From...

  17. 50 CFR 20.24 - Daily limit.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Daily limit. 20.24 Section 20.24 Wildlife... (CONTINUED) MIGRATORY BIRD HUNTING Taking § 20.24 Daily limit. No person shall take in any 1 calendar day, more than the daily bag limit or aggregate daily bag limit, whichever applies....

  18. 50 CFR 20.33 - Possession limit.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Possession limit. 20.33 Section 20.33... PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Possession § 20.33 Possession limit. No person shall possess more migratory game birds taken in the United States than the possession limit or the...

  19. 28 CFR 20.30 - Applicability.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Applicability. 20.30 Section 20.30 Judicial Administration DEPARTMENT OF JUSTICE CRIMINAL JUSTICE INFORMATION SYSTEMS Federal Systems and Exchange of Criminal History Record Information § 20.30 Applicability. The provisions of this subpart...

  20. 28 CFR 20.32 - Includable offenses.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Includable offenses. 20.32 Section 20.32 Judicial Administration DEPARTMENT OF JUSTICE CRIMINAL JUSTICE INFORMATION SYSTEMS Federal Systems and Exchange of Criminal History Record Information § 20.32 Includable offenses. (a) Criminal history...

  1. 28 CFR 20.31 - Responsibilities.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Responsibilities. 20.31 Section 20.31 Judicial Administration DEPARTMENT OF JUSTICE CRIMINAL JUSTICE INFORMATION SYSTEMS Federal Systems and Exchange of Criminal History Record Information § 20.31 Responsibilities. (a) The Federal Bureau...

  2. 28 CFR 20.1 - Purpose.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Purpose. 20.1 Section 20.1 Judicial Administration DEPARTMENT OF JUSTICE CRIMINAL JUSTICE INFORMATION SYSTEMS General Provisions § 20.1 Purpose. It is the purpose of these regulations to assure that criminal history record information wherever...

  3. 28 CFR 20.25 - Penalties.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Penalties. 20.25 Section 20.25 Judicial Administration DEPARTMENT OF JUSTICE CRIMINAL JUSTICE INFORMATION SYSTEMS State and Local Criminal History Record Information Systems § 20.25 Penalties. Any agency or individual violating subpart B of these regulations...

  4. 42 CFR 73.20 - Administrative review.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Administrative review. 73.20 Section 73.20 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES QUARANTINE, INSPECTION, LICENSING SELECT AGENTS AND TOXINS § 73.20 Administrative review. An individual or entity may appeal a...

  5. 50 CFR 80.20 - Land control.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Land control. 80.20 Section 80.20 Wildlife... WILDLIFE RESTORATION AND DINGELL-JOHNSON SPORT FISH RESTORATION ACTS § 80.20 Land control. The State must control lands or waters on which capital improvements are made with Wildlife and Sport Fish...

  6. 7 CFR 1794.20 - Control.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 12 2010-01-01 2010-01-01 false Control. 1794.20 Section 1794.20 Agriculture... (CONTINUED) ENVIRONMENTAL POLICIES AND PROCEDURES Classification of Proposals § 1794.20 Control. Electric and... in the ownership of a project where the applicant(s) does not have sufficient control to alter...

  7. 46 CFR 168.15-20 - Equipment.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Equipment. 168.15-20 Section 168.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS CIVILIAN NAUTICAL SCHOOL VESSELS Accommodations § 168.15-20 Equipment. (a) Each person shall have a separate berth and not more than 1 berth...

  8. 21 CFR 26.20 - Alert system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Alert system. 26.20 Section 26.20 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL MUTUAL RECOGNITION OF... Provisions for Pharmaceutical Good Manufacturing Practices § 26.20 Alert system. (a) The details of an...

  9. 32 CFR 310.20 - Reproduction fees.

    Science.gov (United States)

    2010-07-01

    ... portions of the fee schedule in 32 CFR part 286. ... 32 National Defense 2 2010-07-01 2010-07-01 false Reproduction fees. 310.20 Section 310.20... PROGRAM DOD PRIVACY PROGRAM Access by Individuals § 310.20 Reproduction fees. (a) Assessing fees....

  10. 7 CFR 91.20 - Shipping.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Shipping. 91.20 Section 91.20 Agriculture Regulations... AND GENERAL INFORMATION Samples § 91.20 Shipping. (a) Samples must be submitted to the laboratory in a... for providing shipping containers and paying shipping costs for fee basis tests. (f) A courier...

  11. 7 CFR 20.9 - Records.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Records. 20.9 Section 20.9 Agriculture Office of the Secretary of Agriculture EXPORT SALES REPORTING REQUIREMENTS § 20.9 Records. Each reporting exporter shall... authorized employees of the United States Department of Agriculture and shall be preserved for three...

  12. 47 CFR 32.20 - Numbering convention.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Numbering convention. 32.20 Section 32.20 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES UNIFORM SYSTEM OF ACCOUNTS FOR TELECOMMUNICATIONS COMPANIES General Instructions § 32.20 Numbering convention. (a) The number...

  13. 29 CFR 779.20 - Person.

    Science.gov (United States)

    2010-07-01

    ... INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS THE FAIR LABOR STANDARDS ACT AS APPLIED TO RETAILERS OF GOODS OR SERVICES General Some Basic Definitions § 779.20 Person. As used in the Act (including the... 29 Labor 3 2010-07-01 2010-07-01 false Person. 779.20 Section 779.20 Labor Regulations Relating...

  14. 12 CFR 1710.20 - Indemnification.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Indemnification. 1710.20 Section 1710.20 Banks and Banking OFFICE OF FEDERAL HOUSING ENTERPRISE OVERSIGHT, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT SAFETY AND SOUNDNESS CORPORATE GOVERNANCE Indemnification § 1710.20 Indemnification. (a)...

  15. 28 CFR 570.20 - Purpose.

    Science.gov (United States)

    2010-07-01

    ...-Release Community Confinement § 570.20 Purpose. The purpose of this subpart is to provide the procedures... employment, employment search efforts, community service, vocational training, treatment, educational... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Purpose. 570.20 Section 570.20...

  16. 15 CFR 20.12 - Mediation.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Mediation. 20.12 Section 20.12... Procedures § 20.12 Mediation. (a) DOC will refer to a mediation service designated by the Secretary all... further processing. (b) Both the complainant and the recipient shall participate in the mediation...

  17. 7 CFR 201.20 - Germination.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Germination. 201.20 Section 201.20 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.20 Germination. The label shall show the percentage of germination each kind, or kind and variety, or kind and type, or kind and hybrid of agricultural seed...

  18. 50 CFR 680.20 - Arbitration System.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Arbitration System. 680.20 Section 680.20... Measures § 680.20 Arbitration System. (a) Applicability—(1) Arbitration System. All CVO QS, Arbitration IFQ... establish the Arbitration System. Certain parts of the Arbitration System are voluntary for some parties,...

  19. 36 CFR 331.20 - Advertisement.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Advertisement. 331.20 Section 331.20 Parks, Forests, and Public Property CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY REGULATIONS GOVERNING THE PROTECTION, USE AND MANAGEMENT OF THE FALLS OF THE OHIO NATIONAL WILDLIFE CONSERVATION AREA, KENTUCKY AND INDIANA § 331.20...

  20. 33 CFR 118.20 - Obtaining information.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Obtaining information. 118.20 Section 118.20 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.20 Obtaining information. Persons desiring information concerning...