WorldWideScience

Sample records for carbon 12

  1. Elastic Scattering of CARBON-14 + CARBON-12, Carbon -14 + OXYGEN-16, and CARBON-14 + OXYGEN-18.

    Science.gov (United States)

    Sterbenz, Stephen Michael

    We have carried out highly detailed studies of the elastic scattering of ^{14} C from ^{12}C, ^{16}O, and ^ {18}O, in a search for resonant phenomena in heavy-ion systems of non-zero isospin and zero spin. Angular distributions from ^{14}C+ ^{12}C and ^ {14}C+^{16}O scattering were measured at ^{14} C bombarding energies ranging from 20 to 40.3 MeV in 0.35 MeV steps. ^{14}C+ ^{18}O angular distributions were measured at ^{14}C energies from 20 to 30 MeV in 0.40 MeV steps and from 22.5 to 32.5 MeV in 2.5 MeV steps. The great variety of behavior which characterizes heavy-ion scattering is clearly illustrated by our data. The ^{14}C+^ {12}C and ^{14} C+^{16}O systems both exhibit marked gross structure in their excitation functions and deep oscillatory structure with a large backward angle rise in their angular distributions. They are in sharp contrast with the ^{14} C+^{18}O system, where structure is not apparent, and cross-sections fall steeply at larger angles and higher energies. However, only in the ^{14}C+ ^{12}C system are the excitation functions strongly fragmented by intermediate width structure. The anomalous appearance of the ^{14} C+^{12}C angular distributions near 17.5 MeV (cm) does suggest the existence of a resonant state (tentatively identified as l = 10 by phase shift analysis). In our analysis, we point out that the remarkable qualitative differences among these systems may be related to open-channel systematics. We find that general characteristics of the ^{14}C+ ^{18}O data are reproduced with a strongly absorbing optical potential model, contrary to the situation in the other two systems, where a specific mechanism, such as elastic transfer, must be invoked to account for the backward rise. We have pursued analysis with a one-step DWBA elastic transfer model which was quite successful at low energies. Its underprediction of the backward rise at higher energies provides further evidence of the importance of multi-step processes in two

  2. BOREAS TGB-12 Soil Carbon Data over the NSA

    Science.gov (United States)

    Trumbore, Susan; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor); Harden, Jennifer; Sundquist, Eric; Winston, Greg

    2000-01-01

    The BOREAS TGB-12 team made measurements of soil carbon inventories, carbon concentration in soil gases, and rates of soil respiration at several sites to estimate the rates of carbon accumulation and turnover in each of the major vegetation types. TGB-12 data sets include soil properties at tower and selected auxiliary sites in the BOREAS NSA and data on the seasonal variations in the radiocarbon content of CO2 in the soil atmosphere at NSA tower sites. The sampling strategies for soils were designed to take advantage of local fire chronosequences, so that the accumulation of C in areas of moss regrowth could be determined. These data are used to calculate the inventory of C and N in moss and mineral soil layers at NSA sites and to determine the rates of input and turnover (using both accumulation since the last stand-killing fire and radiocarbon data). This data set includes physical parameters needed to determine carbon and nitrogen inventory in soils. The data were collected discontinuously from August 1993 to July 1996. The data are stored in tabular ASCII files.

  3. States of Carbon-12 in the Skyrme Model

    CERN Document Server

    Lau, P H C

    2014-01-01

    The Skyrme model has two Skyrmion solutions of baryon number $12$, with $D_{3h}$ and $D_{4h}$ symmetries. The first has an equilateral triangular shape and the second an extended linear shape, analogous to the triangle and linear chain structures of three alpha particles. We recalculate the moments of inertia of these Skyrmions, and deduce the energies and spins of their quantized rotational excitations. There is a good match with the ground-state band of Carbon-12, and with the recently established rotational band of the Hoyle state. The ratio of the root mean square matter radii also matches the experimental value.

  4. Friction stir processing on high carbon steel U12

    Energy Technology Data Exchange (ETDEWEB)

    Tarasov, S. Yu., E-mail: tsy@ispms.ru; Rubtsov, V. E., E-mail: rvy@ispms.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Melnikov, A. G., E-mail: melnikov-ag@tpu.ru [National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation)

    2015-10-27

    Friction stir processing (FSP) of high carbon steel (U12) samples has been carried out using a milling machine and tools made of cemented tungsten carbide. The FSP tool has been made in the shape of 5×5×1.5 mm. The microstructural characterization of obtained stir zone and heat affected zone has been carried out. Microhardness at the level of 700 MPa has been obtained in the stir zone with microstructure consisting of large grains and cementitte network. This high-level of microhardness is explained by bainitic reaction developing from decarburization of austenitic grains during cementite network formation.

  5. Friction stir processing on high carbon steel U12

    International Nuclear Information System (INIS)

    Friction stir processing (FSP) of high carbon steel (U12) samples has been carried out using a milling machine and tools made of cemented tungsten carbide. The FSP tool has been made in the shape of 5×5×1.5 mm. The microstructural characterization of obtained stir zone and heat affected zone has been carried out. Microhardness at the level of 700 MPa has been obtained in the stir zone with microstructure consisting of large grains and cementitte network. This high-level of microhardness is explained by bainitic reaction developing from decarburization of austenitic grains during cementite network formation

  6. Coastal climate reflected in carbon-13/carbon-12 ratio of organic carbon in varved sediment from Santa Barbara basin

    OpenAIRE

    Schimmelmann, Arndt; Tegner, Mia J.

    1991-01-01

    A 1844-1987 time-series of carbon stable isotope ratios from dated sedimentary total organic carbon from the center of the Santa Barbara basin is compared with historical climate and oceanographic records. Carbon derived from carbon-13-depleted phytoplankton and carbon-13-enriched kelp appear responsible for a large part of the isotopic variance in sedimentary total organic carbon. El Niño/Southern Oscillation events are recorded by the isotopic response of marine organic carbon in sediments.

  7. Drought indicated in carbon-13/carbon-12 ratios of Southwestern tree rings

    International Nuclear Information System (INIS)

    Stomatal closure during periods of moisture deficiency should theoretically lead to elevated 13C/12C ratios as reduction of available CO2 leads to diminished photosynthetic discrimination against 13C in favor of 12C. Stable-carbon isotope ratio chronologies developed from 5-yr tree-ring groups at 17 sites in six southwestern states were tested for a drought relationship by first fitting a spline curve to each chronology to remove the long-term trend and calculating indices as the ratio of actual to spline curve value. The time series of “Del Indices” so developed are significantly correlated with 5-yr mean Palmer Hydrological Drought Indices (post-1930 period) and reconstructed July Palmer Drought Severity Indices from respective areas. Overall, in the period since 1790, the driest pentads were 1900–04 and 1960–64, whereas the wettest were 1980–84 and 1915–19. Maps of drought represented for two pentads seem to be reasonable representations, although spatial correlations of Del Indices with PHDI were generally not significant. These Del Index drought reconstructions may provide a useful measure of past physiological response to drought (stomatal closure), although the present cost of analysis would prevent this from being a routine method. (author)

  8. Efficacy of supercritical carbon dioxide for nonthermal inactivation of Escherichia coli K12 in apple cider

    Science.gov (United States)

    This study evaluated the efficacy of a supercritical carbon dioxide (SCCO2) system with a gas-liquid porous metal contactor for eliminating Escherichia coli K12 in apple cider. Pasteurized, preservative-free apple cider was inoculated with E. coli K12 and processed using the SCCO2 system at CO2 conc...

  9. BOREAS TGB-12 Soil Carbon and Flux Data of NSA-MSA in Raster Format

    Science.gov (United States)

    Hall, Forrest G. (Editor); Knapp, David E. (Editor); Rapalee, Gloria; Davidson, Eric; Harden, Jennifer W.; Trumbore, Susan E.; Veldhuis, Hugo

    2000-01-01

    The BOREAS TGB-12 team made measurements of soil carbon inventories, carbon concentration in soil gases, and rates of soil respiration at several sites. This data set provides: (1) estimates of soil carbon stocks by horizon based on soil survey data and analyses of data from individual soil profiles; (2) estimates of soil carbon fluxes based on stocks, fire history, drain-age, and soil carbon inputs and decomposition constants based on field work using radiocarbon analyses; (3) fire history data estimating age ranges of time since last fire; and (4) a raster image and an associated soils table file from which area-weighted maps of soil carbon and fluxes and fire history may be generated. This data set was created from raster files, soil polygon data files, and detailed lab analysis of soils data that were received from Dr. Hugo Veldhuis, who did the original mapping in the field during 1994. Also used were soils data from Susan Trumbore and Jennifer Harden (BOREAS TGB-12). The binary raster file covers a 733-km 2 area within the NSA-MSA.

  10. 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.

  11. Vitamin B12: one carbon metabolism, fetal growth and programming for chronic disease.

    Science.gov (United States)

    Rush, E C; Katre, P; Yajnik, C S

    2014-01-01

    This review brings together human and animal studies and reviews that examine the possible role of maternal vitamin B12 (B12) on fetal growth and its programming for susceptibility to chronic disease. A selective literature review was undertaken to identify studies and reviews that investigate these issues, particularly in the context of a vegetarian diet that may be low in B12 and protein and high in carbohydrate. Evidence is accumulating that maternal B12 status influences fetal growth and development. Low maternal vitamin B12 status and protein intake are associated with increased risk of neural tube defect, low lean mass and excess adiposity, increased insulin resistance, impaired neurodevelopment and altered risk of cancer in the offspring. Vitamin B12 is a key nutrient associated with one carbon metabolic pathways related to substrate metabolism, synthesis and stability of nucleic acids and methylation of DNA which regulates gene expression. Understanding of factors regulating maternal-fetal one carbon metabolism and its role in fetal programming of non communicable diseases could help design effective interventions, starting with maternal nutrition before conception. PMID:24219896

  12. Crystalline and tensile properties of carbon nanotube and graphene reinforced polyamide 12 fibers

    Science.gov (United States)

    Chatterjee, S.; Nüesch, F. A.; Chu, B. T. T.

    2013-02-01

    The influence of carbon nanotubes (CNTs) and graphene nanoplatelets (GnPs) on the structure and mechanical properties of polyamide 12 (PA12) fibers was investigated. As seen from wide-angle X-ray diffraction analysis the crystallinity index increases with incorporation of nanofillers due to nucleation effects. Marked improvement was noted for mechanical properties of the composites with increase in elastic modulus, yield stress and strength of the fibers. The most significant improvement of a factor of 4 could be observed for elastic modulus with the inclusion of 0.5 wt.% GnP. A comparative study was made between the fibers reinforced with CNTs and GnPs.

  13. Studies on 12 V substrate-integrated lead-carbon hybrid ultracapacitors

    Indian Academy of Sciences (India)

    A Banerjee; A K Shukla

    2015-05-01

    A cost-effective 12 V substrate-integrated lead-carbon hybrid ultracapacitor is developed and performance tested. These hybrid ultracapacitors employ flexible-graphite sheets as negative plate currentcollectors that are coated amperometrically with a thin layer of conducting polymer, namely poly-aniline to provide good adhesivity to activated-carbon layer. The positive plate of the hybrid ultracapacitors comprise conventional lead-sheet that is converted electrochemically into a substrate-integrated lead-dioxide electrode. 12 V substrate-integrated lead-carbon hybrid ultracapacitors both in absorbent-glass-mat and polymeric silicagel electrolyte configurations are fabricated and characterized. It is possible to realize 12 V configurations with capacitance values of ∼200 F and ∼300 F, energy densities of ∼1.9 Wh kg−1 and ∼2.5 Wh kg−1 and power densities of ∼2 kW kg−1 and ∼0.8 kW kg−1, respectively, having faradaic-efficiency values of ∼90 % with cycle-life in excess of 100,000 cycles. The effective cost of the mentioned hybrid ultracapacitors is estimated to be about ∼4 US$/Wh as compared to ∼20 US$/Wh for commercially available ultracapacitors.

  14. Study of removal of Direct Yellow 12 by cadmium oxide nanowires loaded on activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Ghaedi, Mehrorang, E-mail: m_ghaedi@mail.yu.ac.ir [Chemistry Department, Yasouj University Yasouj 75914-35 (Iran, Islamic Republic of); Sadeghian, Batuol [Chemistry Department, Yasouj University Yasouj 75914-35 (Iran, Islamic Republic of); Kokhdan, Syamak Nasiri, E-mail: syamak.nasiri@yahoo.com [Chemistry Department, Yasouj University Yasouj 75914-35 (Iran, Islamic Republic of); Pebdani, Arezou Amiri [Chemistry Department, Yasouj University Yasouj 75914-35 (Iran, Islamic Republic of); Sahraei, Reza; Daneshfar, Ali; Mihandoost, Asma [Department of Chemistry, University of Ilam, P.O. Box: 65315-516, Ilam (Iran, Islamic Republic of)

    2013-05-01

    In this research, cadmium oxide nanowires loaded on activated carbon (CdO-NW-AC) has been synthesized by a simple procedure and characterized by different techniques such as XRD, SEM and UV–vis spectrometry. This new adsorbent has been efficiently utilized for the removal of the Direct Yellow 12 (DY-12) from wastewater. To obtain maximum DY-12 removal efficiency, the influences of variables such as pH, DY-12 concentration, amount of CdO-NW-AC, contact time, and temperature have been examined and optimized in a batch method. Following the variable optimization, the experimental equilibrium data (at different concentration of DY-12) was fitted to conventional isotherm models such as Langmuir, Freundlich and Tempkin. The applicability of each method is based on the R{sup 2} and error analysis for each model. It was found that the experimental equilibrium data well fitted to the Langmuir isotherm model. The dependency of removal process to time and the experimental data follow second order kinetic model with involvement of intraparticle diffusion model. The negative value of Gibbs's free energy and positive value of adsorption enthalpy show the spontaneous and endothermic nature of adsorption process. - Graphical abstract: Typical FE-SEM image of the CdO nanowires. Highlights: ► Cadmium oxide nanowires loaded on activated carbon was utilized as an adsorbent. ► It was used for the removal of Direct Yellow 12 from aqueous solutions. ► The adsorption of Direct Yellow 12 on this adsorbent is endothermic in nature. ► The adsorption equilibrium data was well described by the Langmuir isotherm model.

  15. Germanomolybdate (GeMo12O404−) Modified Carbon Nanotube Composites for Electrochemical Capacitors

    International Nuclear Information System (INIS)

    Highlights: • GeMo12O404− (GeMo) was deposited onto MWCNT to fabricate capacitive electrodes. • GeMo electrode showed excellent conductivity and 6X the capacitance of bare MWCNT. • GeMo was superimposed with PMo12O403− or SiMo12O404− on dual-layer electrodes. • Dual-layer electrodes showed combination of both molecules and 12X bare capacitance. - Abstract: Keggin type germanomolybdate, GeMo12O404− (GeMo), was deposited onto multi-walled carbon nanotubes (MWCNT) via layer-by-layer (LbL) deposition to form composite electrodes for electrochemical capacitors (ECs). The GeMo composite electrode demonstrated charge storage six times greater than that of the bare MWCNT electrode while maintaining excellent conductivity and cycling stability. GeMo also demonstrated charge storage complementary to that of the commercial Keggin type POMs, PMo12O403− (PMo) and SiMo12O404− (SiMo). Dual-layer coatings superimposing GeMo with either PMo or SiMo showed an additive combination of both active layers, which resulted in cyclic voltammograms (CVs) with overlapping redox features and charge storage twelve times greater than that of the bare MWCNT electrode. Scanning Electron Microscopy (SEM) demonstrated successful single and dual layer coating of POMs on MWCNT with high coverage and uniform surface morphologies

  16. Energy loss of /sup 12/C projectiles in different carbon modifications

    International Nuclear Information System (INIS)

    The stopping cross sections of the three carbon modifications diamond, graphite, and glassy carbon are investigated for carbon projectiles of intermediate velocity. The inverted Doppler-shift attenuation method was used as the experimental technique, and it enabled us to measure the ratios of the three stopping cross sections precisely over a wide energy range. For velocities between 3 and 4 times Bohr's velocity the stopping cross sections of graphite and glassy carbon are found to be 1.036 and 1.072 times larger than that of diamond, respectively. These differences are attributed to binding effects. To understand these effects, we have evaluated the mean ionization potentials utilizing the local-plasma approximation for the inner-shell electrons and the dielectric response function for the valence electrons. The theoretical ratios calculated by inserting these potentials into the Bethe-Bloch stopping-power formula agree well with our experimental results. Furthermore, we have obtained a value of 53.3 +- 4.1 fs for the lifetime of the first excited state of the /sup 12/C nucleus

  17. Effect of carbon content on microstructure and mechanical properties of hot-rolled low carbon 12Cr-Ni stainless steel

    International Nuclear Information System (INIS)

    Research highlights: → Hot-rolled ultra low carbon martensite is characterized by dislocation cells substructure. → The formation of dislocation cells is attributed to high Ms and low interstitial atoms content. → Hot-rolled ultra low carbon 12Cr-Ni stainless steel has excellent impact toughness. → Delta ferrite deteriorates the impact toughness of hot-rolled 12Cr-Ni stainless steel. - Abstract: 12Cr-Ni stainless steels containing different carbon contents from 0.004 wt.% to 0.034 wt.% were hot-rolled and air-cooled. Their corresponding microstructures were observed with optical microscope and transmission electron microscope, and the Vickers hardness, tensile and impact tests were also carried out. It was found that the martensitic morphology was significantly influenced by carbon content. The as-received ultra low carbon martensite in the steel containing 0.004 wt.% C is characterized by dislocation cells substructure. The formation of dislocation cells is attributed to high martensite finishing point (above 400 deg. C) and low interstitial atoms content. On the other hand, the martensite in the steel containing 0.034 wt.% C consists mainly of typical martensite laths because of low martensite finishing point and high interstitial atoms content which hinder dislocation motion. Furthermore, carbon content has an evident effect on the mechanical properties of 12Cr-Ni steels. The hardness and strength of the as-received steels increase with an increase in carbon content, but their elongation and impact toughness decrease with the carbon content. The steel containing 0.004 wt.% C has excellent impact toughness due to the ultra low carbon content in the martensite composed of dislocation cells.

  18. A photochemical model for the carbon-rich planet WASP-12b

    CERN Document Server

    Kopparapu, Ravi kumar; Zahnle, Kevin J

    2011-01-01

    The hot Jupiter WASP-12b is a heavily irradiated exoplanet in a short period orbit around a G0-star with twice the metallicity of the Sun. A recent thermochemical equilibrium analysis based on Spitzer and ground-based infrared observations suggests that the presence of $\\ch4$ in its atmosphere and the lack of $\\h2o$ features can only be explained if the carbon-to-oxygen ratio in the planet's atmosphere is much greater than the solar ratio ($\\ctoo = 0.54$). Here, we use a 1-D photochemical model to study the effect of disequilibrium chemistry on the observed abundances of $\\h2o, \\com, \\co2$ and $\\ch4$ in the WASP-12b atmosphere. We consider two cases: one with solar $\\ctoo$ and another with $\\ctoo = 1.08$. The solar case predicts that $\\h2o$ and $\\com$ are more abundant than $\\co2$ and $\\ch4$, as expected, whereas the high $\\ctoo$ model shows that $\\com$, C$_{2}$H$_{2}$ and HCN are more abundant. This indicates that the extra carbon from the high $\\ctoo$ model is in hydrocarbon species. $\\h2o$ photolysis is th...

  19. Comparing carbon nanotubes and graphene nanoplatelets as reinforcements in polyamide 12 composites

    Science.gov (United States)

    Chatterjee, S.; Nüesch, F. A.; Chu, B. T. T.

    2011-07-01

    We investigate the influence of nanofillers including carbon nanotubes (CNTs) and graphene nanoplatelets on a thermoplastic engineering polymer, polyamide 12 (PA12). The comparison between these two important nanofillers as to how they influence the structure and properties of the polymer is systematically studied. The polymer-nanofiller composites were prepared using a twin-screw micro-extruder and the composite was thereafter hot pressed into thin films. The structure (using wide angle x-ray diffraction and differential scanning calorimetry) and properties (through tensile testing and conductivity measurement) of the thin films have been investigated. The composites incorporating surfactant showed the best CNT distribution and dispersion, causing an improvement of up to 80% in the toughness modulus over pure PA12. Electrical percolation could also be achieved at nanofiller concentrations of 1 to 2 wt%. In this study we observed that CNT fillers bring about more pronounced improvements in PA12 compared to graphene nanoplatelets, as far as mechanical and electrical properties are concerned.

  20. Comparing carbon nanotubes and graphene nanoplatelets as reinforcements in polyamide 12 composites

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, S; Nueesch, F A; Chu, B T T, E-mail: bryan.chu@empa.ch [EMPA, Laboratory for Functional Polymers, Swiss Federal Laboratories for Materials Science and Technology (Switzerland)

    2011-07-08

    We investigate the influence of nanofillers including carbon nanotubes (CNTs) and graphene nanoplatelets on a thermoplastic engineering polymer, polyamide 12 (PA12). The comparison between these two important nanofillers as to how they influence the structure and properties of the polymer is systematically studied. The polymer-nanofiller composites were prepared using a twin-screw micro-extruder and the composite was thereafter hot pressed into thin films. The structure (using wide angle x-ray diffraction and differential scanning calorimetry) and properties (through tensile testing and conductivity measurement) of the thin films have been investigated. The composites incorporating surfactant showed the best CNT distribution and dispersion, causing an improvement of up to 80% in the toughness modulus over pure PA12. Electrical percolation could also be achieved at nanofiller concentrations of 1 to 2 wt%. In this study we observed that CNT fillers bring about more pronounced improvements in PA12 compared to graphene nanoplatelets, as far as mechanical and electrical properties are concerned.

  1. Enhanced electrochemical performance of Li4Ti5O12 as anode material for lithium-ion batteries with different carbons as support

    International Nuclear Information System (INIS)

    Nano-Li4Ti5O12/carbon composites with various structures are designed using tetrabutyl titanate as a precursor via a facile in situ liquid deposition method in the presence of three different carbons (multiwalled carbon nanotubes, spherical conductive carbon black super-P and ordered macroporous carbon). The nano-Li4Ti5O12/carbon composites with various morphologies are formed depending on the carbon matrixes used. The Li4Ti5O12 particles obtained are approximately 100 nm in size and homogeneously dispersed in different carbon matrixes. It is found that the structures of the carbon matrixes have a close relation to the discharge capacities of the composites. At the discharge current density of 875 mA g−1, the discharge capacities of nano-Li4Ti5O12/carbon composites with 10 wt% carbon are 138.6, 120.8 and 120.9 mAh g−1 for carbon nanotubes, super-P and porous carbon as the carbon supports, respectively. The nano-Li4Ti5O12/carbon using carbon nanotubes as support exhibits superior performance with large reversible capacity, excellent cycle stability and good rate capability. Capacity retention of 99% can be maintained after 100 cycles, suggesting its promising potential as anode materials. - Highlights: • Li4Ti5O12/carbon nanocomposites are designed using different carbons as supports. • Li4Ti5O12 particles formed on carbon matrix are fine and homogeneous. • Aggregation and growth of Li4Ti5O12 particles are inhibited. • The Li4Ti5O12/carbon nanocomposites exhibit superior electrochemical performance

  2. 40 CFR 600.510-12 - Calculation of average fuel economy and average carbon-related exhaust emissions.

    Science.gov (United States)

    2010-07-01

    ... must meet the minimum driving range requirements established by the Secretary of Transportation (49 CFR... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Calculation of average fuel economy and average carbon-related exhaust emissions. 600.510-12 Section 600.510-12 Protection of...

  3. Comprehensive analysis of the metabolome of Pseudomonas putida S12 grown on different carbon sources.

    Science.gov (United States)

    van der Werf, Mariët J; Overkamp, Karin M; Muilwijk, Bas; Koek, Maud M; van der Werff-van der Vat, Bianca J C; Jellema, Renger H; Coulier, Leon; Hankemeier, Thomas

    2008-04-01

    Metabolomics is an emerging, powerful, functional genomics technology that involves the comparative non-targeted analysis of the complete set of metabolites in an organism. We have set-up a robust quantitative metabolomics platform that allows the analysis of 'snapshot' metabolomes. In this study, we have applied this platform for the comprehensive analysis of the metabolite composition of Pseudomonas putida S12 grown on four different carbon sources, i.e. fructose, glucose, gluconate and succinate. This paper focuses on the microbial aspects of analyzing comprehensive metabolomes, and demonstrates that metabolomes can be analyzed reliably. The technical (i.e. sample work-up and analytical) reproducibility was on average 10%, while the biological reproducibility was approximately 40%. Moreover, the energy charge values of the microbial samples generated were determined, and indicated that no biotic or abiotic changes had occurred during sample work-up and analysis. In general, the metabolites present and their concentrations were very similar after growth on the different carbon sources. However, specific metabolites showed large differences in concentration, especially the intermediates involved in the degradation of the carbon sources studied. Principal component discriminant analysis was applied to identify metabolites that are specific for, i.e. not necessarily the metabolites that show those largest differences in concentration, cells grown on either of these four carbon sources. For selected enzymatic reactions, i.e. the glucose-6-phosphate isomerase, triosephosphate isomerase and phosphoglyceromutase reactions, the apparent equilibrium constants (K(app)) were calculated. In several instances a carbon source-dependent deviation between the apparent equilibrium constant (K(app)) and the thermodynamic equilibrium constant (K(eq)) was observed, hinting towards a potential point of metabolic regulation or towards bottlenecks in biosynthesis routes. For glucose-6

  4. 12 Years of NPK Addition Diminishes Carbon Sink Potential of a Nutrient Limited Peatland

    Science.gov (United States)

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

    2011-12-01

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

  5. Synthesis and properties of novel aliphatic polycarbonate from carbon dioxide with 1,2-butylene oxide and ε-caprolactone

    Institute of Scientific and Technical Information of China (English)

    Yan Fei Liu; Ke Long Huang; Dong Ming Peng; Su Qin Liu; Hong Wu

    2007-01-01

    A new degradable aliphatic poly(butylene-co-ε-caprolactone carbonate) (PBCL) was synthesized through the terpolymerization of carbon dioxide, 1,2-butylene oxide (BO) and ε-caprolactone (CL), a polymer supported bimetallic complex (PBM) was used as a catalyst. The terpolymers prepared were characterized by FT-IR, 1H NMR, 13C NMR, WXRD and DSC. The hydrolysis tests were carried out to appraise the degradability of the copolymers.

  6. Electrophysiological Monitoring in Patients With Tumors of the Skull Base Treated by Carbon-12 Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Carozzo, Simone [Department of Neuroscience, Ophthalmology, and Genetics, University of Genova, Genova (Italy); Schardt, Dieter [Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany); Narici, Livio [Department of Physics, University of Rome Tor Vergata, Rome (Italy); Combs, Stephanie E.; Debus, Jürgen [Department of Radiation Oncology, University of Heidelberg, Heidelberg (Germany); Sannita, Walter G., E-mail: wgs@dism.unige.it [Department of Neuroscience, Ophthalmology, and Genetics, University of Genova, Genova (Italy); Department of Psychiatry, State University of New York, Stony Brook, New York (United States)

    2013-03-15

    Purpose: To report the results of short-term electrophysiologic monitoring of patients undergoing {sup 12}C therapy for the treatment of skull chordomas and chondrosarcomas unsuitable for radical surgery. Methods and Materials: Conventional electroencephalogram (EEG) and retinal and cortical electrophysiologic responses to contrast stimuli were recorded from 30 patients undergoing carbon ion radiation therapy, within a few hours before the first treatment and after completion of therapy. Methodologies and procedures were compliant with the guidelines of the International Federation for Clinical Neurophysiology and International Society for Clinical Electrophysiology of Vision. Results: At baseline, clinical signs were reported in 56.6% of subjects. Electrophysiologic test results were abnormal in 76.7% (EEG), 78.6% (cortical evoked potentials), and 92.8% (electroretinogram) of cases, without correlation with neurologic signs, tumor location, or therapy plan. Results on EEG, but not electroretinograms and cortical responses, were more often abnormal in patients with reported clinical signs. Abnormal EEG results and retinal/cortical responses improved after therapy in 40% (EEG), 62.5% (cortical potentials), and 70% (electroretinogram) of cases. Results on EEG worsened after therapy in one-third of patients whose recordings were normal at baseline. Conclusions: The percentages of subjects whose EEG results improved or worsened after therapy and the improvement of retinal/cortical responses in the majority of patients are indicative of a limited or negligible (and possibly transient) acute central nervous system toxicity of carbon ion therapy, with a significant beneficial effect on the visual pathways. Research on large samples would validate electrophysiologic procedures as a possible independent test for central nervous system toxicity and allow investigation of the correlation with clinical signs; repeated testing over time after therapy would demonstrate, and may

  7. Removal of Direct Yellow-12 Dye from Water by Adsorption on Activated Carbon Prepared from Ficus Racemosa L.

    OpenAIRE

    Revathi, G.; Ramalingam, S; P. Subramaniam; A. Ganapathi

    2011-01-01

    The adsorption of direct yellow-12 dye (DY-12) by Atti leaf (Ficus racemosa) powder carbon (ATC) was carried out by varying the parameters such as agitation time, dye concentration, adsorbent dose, pH and temperature. Equilibrium adsorption data followed both Langmuir and Freundlich isotherms. Adsorption followed second-order kinetics. The adsorption capacity was found to be 6.7 mg dye per gram of the adsorbent. Acidic pH was favorable for the adsorption of DY-12. Desorption studies suggest t...

  8. Fossil and Contemporary Fine Carbon Fractions at 12 Rural and Urban Sites in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Schichtel, B; Malm, W; Bench, G; Fallon, S; McDade, C; Chow, J

    2007-03-01

    Fine particulate matter collected at two urban, four near-urban, and six remote sites throughout the United States were analyzed for total carbon (TC) and radiocarbon ({sup 14}C). Samples were collected at most sites for both a summer and winter season. The radiocarbon was used to partition the TC into fossil and contemporary fractions. On average, contemporary carbon composed about half of the carbon at the urban, {approx}70-97% at near-urban, and 82-100% at remote sites. At Phoenix, Arizona, and Seattle, Washington, one monitor was located within the urban center and one outside to assess the urban excess over background concentrations. During the summer the urban and rural sites had similar contemporary carbon concentrations. However, during the winter the urban sites had more than twice the contemporary carbon measured at the neighboring sites, indicating anthropogenic contributions to the contemporary carbon. The urban fossil carbon was 4-20 times larger than the neighboring rural sites for both seasons. Organic (OC) and elemental carbon (EC) from TOR analysis were available. These and the radiocarbon data were used to estimate characteristic fossil and contemporary EC/TC ratios for the winter and summer seasons. These ratios were applied to carbon data from the Interagency Monitoring of Protected Visual Environments network to estimate the fraction of contemporary carbon at mostly rural sites throughout the United States. In addition, the ratios were used to develop a semiquantitative, lower bound estimate of secondary organic carbon (SOC) contribution to fossil and contemporary carbon. SOC accounted for more than one-third of the fossil and contemporary carbon.

  9. World Carbon Black Output to Reach 12.7 Million Tons in 2015

    Institute of Scientific and Technical Information of China (English)

    Zhu Yongkang

    2012-01-01

    From April 13 to April 17, "Carbon Black China of 2012" (CBC2012) was held in Hangzhou, China. Mr. Paul Ita, the president of US marketing research institution Notch Consulting Group, announced that the prospect of carbon black industry was closely linked with the development of auto industry and tire industry. The demand for carbon black of 2010 increased by 15% compared with that of 2009; the growth rate of demand for carbon black was 5.8% in 2011 and the total output was 10.7 million tons, which increased by about 5.5% compared with that of 2010.

  10. G64-12 and G64-37 are Carbon-Enhanced Metal-Poor Stars

    CERN Document Server

    Placco, Vinicius M; Reggiani, Henrique; Melendez, Jorge

    2016-01-01

    We present new high-resolution chemical-abundance analyses for the well-known high proper-motion subdwarfs G64-12 and G64-37, based on very high signal-to-noise spectra (S/N ~ 700/1) with resolving power R ~ 95,000. These high-quality data enable the first reliable determination of the carbon abundances for these two stars; we classify them as carbon-enhanced metal-poor (CEMP) stars based on their carbonicities, which both exceed [C/Fe] = +1.0. They are sub-classified as CEMP- no Group-II stars, based on their location in the Yoon-Beers diagram of absolute carbon abundance, A(C) vs. [Fe/H], as well as on the conventional diagnostic [Ba/Fe]. The relatively low absolute carbon abundances of CEMP-no stars, in combination with the high effective temperatures of these two stars (Teff ~ 6500 K) weakens their CH molecular features to the point that accurate carbon abundances can only be estimated from spectra with very high S/N. A comparison of the observed abundance patterns with the predicted yields from massive, ...

  11. 40 CFR 600.208-12 - Calculation of FTP-based and HFET-based fuel economy and carbon-related exhaust emission values...

    Science.gov (United States)

    2010-07-01

    ...-based fuel economy and carbon-related exhaust emission values for a model type. 600.208-12 Section 600.208-12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) ENERGY POLICY FUEL ECONOMY AND CARBON-RELATED EXHAUST EMISSIONS OF MOTOR VEHICLES Fuel Economy Regulations for 1977 and...

  12. 40 CFR 600.206-12 - Calculation and use of FTP-based and HFET-based fuel economy and carbon-related exhaust emission...

    Science.gov (United States)

    2010-07-01

    ... HFET-based fuel economy and carbon-related exhaust emission values for vehicle configurations. 600.206-12 Section 600.206-12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) ENERGY POLICY FUEL ECONOMY AND CARBON-RELATED EXHAUST EMISSIONS OF MOTOR VEHICLES Fuel Economy Regulations...

  13. Electrochemical quartz crystal microbalance measurement of a Li4Ti5O12 composite electrode in a carbonate electrolyte

    Science.gov (United States)

    Serizawa, Nobuyuki; Shono, Kumi; Kobayashi, Yo; Miyashiro, Hajime; Katayama, Yasushi; Miura, Takashi

    2015-11-01

    Electrochemical quartz crystal microbalance (EQCM) measurement is conducted with a Li4Ti5O12 (lithium titanium oxide, LTO)-coated quartz crystal electrode in a carbonate electrolyte (ethylene carbonate + dimethyl carbonate; 50: 50 vol%) containing 1 M LiPF6. In-situ monitoring of the mass change during the charge and discharge of the LTO electrode can be achieved quantitatively because of the "zero-strain" property of LTO with Li+ insertion and the probably low reactivity between LTO and the electrolyte. The local changes of viscosity and density of the electrolyte contacting the LTO electrode are detected via the resonance resistance of the quartz crystal electrode, suggesting the local concentrations of Li+ and counter anion changed significantly during insertion and extraction of Li+ in the organic electrolyte.

  14. Metalloradical-Catalyzed Selective 1,2-Rh-H Insertion into the Aliphatic Carbon-Carbon Bond of Cyclooctane

    NARCIS (Netherlands)

    Y.W. Chan; B. de Bruin; K.S. Chan

    2015-01-01

    The selective aliphatic carboncarbon activation of cyclo-octane (c-octane) was achieved via the Rh-II(ttp)-catalyzed 1,2-addition of Rh(ttp)H to give Rh(ttp)(n-octyl) (ttp = tetratolylporphyrinato dianion) in good yield under mild reaction conditions. This mechanism is further supported by DFT calcu

  15. Electrodeposition of Nickel onto 12K Carbon Fibre Tow in a Continuous Manner

    OpenAIRE

    Pierozynski, Boguslaw

    2012-01-01

    Nickel-coated carbon fibre (NiCCF) is an important composite material, which finds nu- merous engineering applications, primarily within: computer, telecommunication, automotive and military industries. In general, NiCCF can be produced by one of the three methods, namely: chemical vapour deposition (CVD), electroless, and electrochemical (galvanic) deposition of Ni on a carbon fibre tow material. The present paper reports a study of the process of nickel electrodeposition (at ultrathin layer...

  16. Processing and characterization of a carbon black-filled electrically conductive Nylon-12 nanocomposite produced by selective laser sintering

    International Nuclear Information System (INIS)

    Selective laser sintering (SLS), a layered manufacturing technique was explored to process an electrically conductive polymer nanocomposite made of Nylon-12 reinforced with 4 wt% of carbon black. SLS process parameters were optimized in order to maximize the flexural modulus. The porosity and morphology were studied using optical microscopy and scanning electron microscopy (SEM). The crystalline state was characterized using differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The electrical conductivity was determined using the four probe technique. Results indicate that carbon black-filled Nylon-12 nanocomposites can be successfully made by SLS. Maximum flexural modulus values of 1750 MPa and 1450 MPa were achieved for the neat polymer and the nanocomposite, respectively. A reduction in the flexural modulus of the nanocomposite is likely due to the formation of a segregated structure in the nanocomposite and a weak polymer-filler interface. The optimized neat polymer and the nanocomposites had average densities of around 97% and 96% relative to full density, respectively. The electrical conductivity of the nanocomposite was approximately 1 x 10-4 S/cm, which is five orders of magnitude higher than that of the neat polymer processed by SLS, and indicates that the onset of percolation behavior occurs below the 4 wt% loading of carbon black.

  17. Carbon sequestration in surface flow constructed wetland after 12 years of swine wastewater treatment

    Science.gov (United States)

    Constructed wetlands used for the treatment of swine wastewater may potentially sequester significant amounts of carbon. In past studies, we evaluated the treatment efficiency of wastewater in marsh-pond-marsh design wetland system. The functionality of this system was highly dependent on soil carbo...

  18. THE INFLUENCE OF THE POROUS STRUCTURE OF LOCAL ACTIVATED CARBONS ON THE IMMOBILIZATION OF THE CONGO RED DYE AND VITAMIN B 12

    Directory of Open Access Journals (Sweden)

    N. Timbaliuc

    2013-06-01

    Full Text Available The adsorption properties of activated carbons, obtained from local raw materials (nut shells, peach and plum stones, towards Congo Red and vitamin B12 have been studied. The values of adsorption of these marker-substances are in direct correlation with the structural characteristics of the studied samples of activated carbons, in particular, with their mesopore volume.

  19. Caractérisation des endommagements d'un composite Carbone/PA12 par émission acoustique

    OpenAIRE

    Philip, F.; Godin, N.; Deschanel, S.; M. Leroy, J.; Grosjean, F.; Courbon, J.

    2011-01-01

    International audience Cet article porte sur la caractérisation de l'endommagement par émission acoustique d'un matériau composite carbone / polyamide 12 (PA12) à fibres longues. L'objectif de ce travail est de discriminer en temps réel les différents types d'endommagement au sein du composite afin de mieux comprendre les mécanismes mis en jeu qui conduisent à la ruine de la structure. Une technique de classification supervisée a été utilisée. L'intérêt de cette technique est de pouvoir ét...

  20. Differentiation of Pigment in Eggs Using Carbon ((13)C/(12)C) and Nitrogen ((15)N/(14)N) Stable Isotopes.

    Science.gov (United States)

    Sun, Feng M; Shi, Guang Y; Wang, Hui W

    2016-07-01

    Consumers prefer natural and healthy food, but artificial pigments are often abused in egg products. The study aimed at differentiating the origin of pigments in eggs by applying the technique of carbon ((13)C/(12)C) and nitrogen ((15)N/(14)N) stable isotope analysis. Five hundred sixty laying hens were randomly distributed into 14 treatments, which were divided into four groups: maize, carophyll red pigment, carophyll yellow pigment, and a mixture of carophyll red and yellow pigments. Eggs were collected and pretreated to determe the values of the Roche Yolk Color Fan (RCF), δ(13)C, and δ(15)N. With increasing maize content, the RCF and δ(13)C values of yolks increased. Moreover, the RCF values in the three pigment groups were significantly influenced by the artificial colors, but δ(13)C values were not significantly different, regardless of the existence of pigment. The δ(15)N values in all treatments did not vary as regularly as the carbon stable isotope. A strong positive correlation was found between RCF and δ(13)C in the maize group, but no such correlation was be observed in the pigment groups. It is concluded that carbon stable isotope ratio analysis (δ(13)C) of the yolk can be used to differentiate the origin of the pigment added to eggs.

  1. Adoption of carbon dioxide efficient technologies and practices: An analysis of sector-specific convergence trends among 12 nations

    International Nuclear Information System (INIS)

    Carbon dioxide intensities in economic terms (GDP in PPP terms) in industrialized and developing countries have been shown to converge, and it has been argued that technology diffusion, leading to the use of similar technologies in all countries, is an important reason for this convergence. Indicators based on CO2 per output in PPP terms, however, give in comparison to physical indicators limited understanding of the process of technology diffusion. In order to analyze the technology diffusion hypothesis in more detail, we therefore study the trend in carbon dioxide emissions in relation to the production output in four separate sectors: iron and steel; paper, board and pulp; coal fuelled power plants; and natural gas fuelled power plants, in each of 12 countries, between 1980 and 1998. The indicators converge in each sector, indicating that across countries, technologies with more similar carbon dioxide efficiencies are used today than 25 years ago. We also find that at least some developing countries with high energy prices use more efficient technologies than industrialized countries with low energy prices

  2. Differentiation of Pigment in Eggs Using Carbon ((13)C/(12)C) and Nitrogen ((15)N/(14)N) Stable Isotopes.

    Science.gov (United States)

    Sun, Feng M; Shi, Guang Y; Wang, Hui W

    2016-07-01

    Consumers prefer natural and healthy food, but artificial pigments are often abused in egg products. The study aimed at differentiating the origin of pigments in eggs by applying the technique of carbon ((13)C/(12)C) and nitrogen ((15)N/(14)N) stable isotope analysis. Five hundred sixty laying hens were randomly distributed into 14 treatments, which were divided into four groups: maize, carophyll red pigment, carophyll yellow pigment, and a mixture of carophyll red and yellow pigments. Eggs were collected and pretreated to determe the values of the Roche Yolk Color Fan (RCF), δ(13)C, and δ(15)N. With increasing maize content, the RCF and δ(13)C values of yolks increased. Moreover, the RCF values in the three pigment groups were significantly influenced by the artificial colors, but δ(13)C values were not significantly different, regardless of the existence of pigment. The δ(15)N values in all treatments did not vary as regularly as the carbon stable isotope. A strong positive correlation was found between RCF and δ(13)C in the maize group, but no such correlation was be observed in the pigment groups. It is concluded that carbon stable isotope ratio analysis (δ(13)C) of the yolk can be used to differentiate the origin of the pigment added to eggs. PMID:27302905

  3. [NEURONAL DIFFERENTIATION OF PC12 CELL LINE AND MURINE NEURAL STEM CELLS ON THE CARBON NANOTUBES FILMS].

    Science.gov (United States)

    Posypanova, G A; Gaiduchenko, A I; Moskaleva, E Yu; Fedorov, G E

    2016-01-01

    The study of the interaction of nerve cells with specially designed substrates (scaffolds) with different surface characteristics at the nanoscale is a necessary step in the development of methods of stimulation of regeneration of nervous tissues, as well as to create next generation of bioelectronic devices. A promising material for such scaffolds may be carbon nanotubes (CNT) that are flexible films of graphene rolled into nano-sized cylindrical tubes. CNT were produced by chemical deposition from the gas phase. The analysis of the PC12 cells cultivated on quartz glass coated by carbon nanotubes films using electron and light microscopy has shown that CNT stimulate the proliferation and do not inhibit neuronal differentiation of PC12 cells. We have found that it is possible to obtain differentiated neurons from murine neural stem cells on the quartz glasses covered with CNT films. The data obtained indicate that the CNT films produced by chemical deposition from the gas phase onto quartz glass may be used as the electro conductive scaffold to obtain and study the functions of neural cells and possibly of mature neurons. PMID:27228654

  4. Gas-Phase Synthesis of Dimethyl Carbonate from Methanol and Carbon Dioxide Over Co1.5PW12O40 Keggin-Type Heteropolyanion

    Directory of Open Access Journals (Sweden)

    Ahmed Aouissi

    2010-03-01

    Full Text Available The reactivity of Co1.5PW12O40 in the direct synthesis of dimethyl carbonate (DMC from CO2 and CH3OH was investigated. The synthesized catalyst has been characterized by means of FTIR, XRD, TG, and DTA and tested in gas phase under atmospheric pressure. The effects of the reaction temperature, time on stream, and methanol weight hourly space velocity (MWHSV on the conversion and DMC selectivity were investigated. The highest conversion (7.6% and highest DMC selectivity (86.5% were obtained at the lowest temperature used (200 °C. Increasing the space velocity MWHSV increased the selectivity of DMC, but decreased the conversion. A gain of 18.4% of DMC selectivity was obtained when the MWHSV was increased from 0.65 h-1 to 3.2 h-1.

  5. Microstructural morphology of the semi-solid high carbon steel T12 before and after rheo-rolling

    Institute of Scientific and Technical Information of China (English)

    Jiguang Li; Yonglin Kang; Aimin Zhao; Yi Sun; Man Cheng

    2005-01-01

    The semi-solid high carbon steel T12 was rolled in a closed box groove under a certain condition by the rheo-rolling equipment, and the microstructural morphology of the semi-solid T12 before and after deformation was investigated by optical microscope to analyze and summarize the microstructure evolution law of T12 deformed in semi-solid state. The experiment results show that the grain shape before deformation of the semi-solid T12 steel displays globule or ellipse by the electromagnetic stirring,the distribution of solid and liquid phases is homogeneous. But the microstructure of semi-solid product after rheo-rolling exhibits macrosegregation that the distribution of liquid and solid phases changes, the liquid phases divorce from the solid phases. In the transverse section, most of the solid phases get together in the center of the specimen, the liquid phases flow to the surface or the edge of the specimen, and the grains occur plastic deformation while reduction increased. In longitudinal section, the middle microstructure of the specimen is more homogeneous than that at the head or tail, the head microstructure is similar to the tail and the size of the grains is not homogeneous.

  6. The electron mass from $g$-factor measurements on hydrogen-like carbon $^{12}$C$^{5+}$

    CERN Document Server

    Köhler, Florian; Kracke, Anke; Werth, Günter; Quint, Wolfgang; Blaum, Klaus

    2016-01-01

    The electron mass in atomic mass units has been determined with a relative uncertainty of $2.8\\cdot 10^{-11}$, which represents a 13-fold improvement of the 2010 CODATA value. The underlying measurement principle combines a high-precision measurement of the Larmor-to-cyclotron frequency ratio on a single hydrogen-like carbon ion in a Penning trap with a corresponding very accurate $g$-factor calculation. Here, we present the measurement results in detail, including a comprehensive discussion of the systematic shifts and their uncertainties. A special focus is set on the various sources of phase jitters, which are essential for the understanding of the applied line-shape model for the $g$-factor resonance.

  7. The Galactic R Coronae Borealis Stars: The C2 Swan Bands, the Carbon Problem, and the 12C/13C Ratio

    Science.gov (United States)

    Hema, B. P.; Pandey, Gajendra; Lambert, David L.

    2012-03-01

    Observed spectra of R Coronae Borealis (RCB) and hydrogen-deficient carbon (HdC) stars are analyzed by synthesizing the C2 Swan bands (1, 0), (0, 0), and (0, 1) using our detailed line list and the Uppsala model atmospheres. The (0, 1) and (0, 0) C2 bands are used to derive the 12C abundance, and the (1, 0) 12C13C band to determine the 12C/13C ratios. The carbon abundance derived from the C2 Swan bands is about the same for the adopted models constructed with different carbon abundances over the range 8.5 (C/He = 0.1%) to 10.5 (C/He = 10%). Carbon abundances derived from C I lines are about a factor of four lower than the carbon abundance of the adopted model atmosphere over the same C/He interval, as reported by Asplund et al., who dubbed the mismatch between adopted and derived C abundance as the "carbon problem." In principle, the carbon abundances obtained from C2 Swan bands and that assumed for the model atmosphere can be equated for a particular choice of C/He that varies from star to star. Then, the carbon problem for C2 bands is eliminated. However, such C/He ratios are in general less than those of the extreme helium stars, the seemingly natural relatives to the RCB and HdC stars. A more likely solution to the C2 carbon problem may lie in a modification of the model atmosphere's temperature structure. The derived carbon abundances and the 12C/13C ratios are discussed in light of the double degenerate and the final flash scenarios.

  8. Nonthermal inactivation of Escherichia coli K12 in buffered peptone water using a pilot-plant scale supercritical carbon dioxide system with gas-liquid porous metal contractor

    Science.gov (United States)

    This study evaluated the effectiveness of a supercritical carbon dioxide (SCCO2) system, with a gas-liquid CO2 contactor, for reducing Escherichia coli K12 in diluted buffered peptone water. 0.1% (w/v) buffered peptone water inoculated with E. coli K12 was processed using the SCCO2 system at CO2 con...

  9. Forest management and carbon storage: an analysis of 12 key forest nations

    Energy Technology Data Exchange (ETDEWEB)

    Winjum, J.K.; Dixon, R.K.; Schroeder, P.E. (National Council for Air and Steam Improvement, Corvallis, OR (United States). USEPA Environmental Research Laboratory)

    1993-10-01

    Forests of the world sequester and conserve more C than all other terrestrial ecosystems and account for 90% of the annual C flux between the atmosphere and the Earth's land surface. Preliminary estimates indicate that forest and agroforest management practices throughout the world can enhance the capability of forests to sequester C and reduce accumulation of greenhouse gases in the atmosphere. Yet of the 3600 C 10[sup 6] ha of forest in the world today, only about 10% (350 x 10[sup 6] ha) are actively managed. The impetus to expand lands managed for forestry or agroforestry purposes lies primarily with nations having forest resources. In late 1990, an assessment was initiated to evaluate the biological potential and initial site costs of managed forest and agroforest systems to sequester C. Within the assessment, 12 key forested nations were the focus of a special analysis: Argentina, Australia, Brazil, Canada, China, Germany, India, Malaysia, Mexico, South Africa, former USSR and USA. These nations contain 59% of the world's natural forests and are representative of the world's boreal, temperate, and tropical forest biomes. Assessment results indicate that though the world's forests are contained in 138 nations, a subset of key nations, such as the 12 selected for this analysis, can significantly contribute to the global capability to sequester C through managed tree crops. Collectively, the 12 nations are estimated to have the potential to store 25.7 Pg C, once expanded levels of practices such as reforestation, afforestation, natural regeneration and agroforestry are implemented and maintained. Initial site costs based upon establishment costs for management practices are less than US$33/Mg C. 55 refs., 2 tabs.

  10. A study of isospin symmetry breaking in carbon 12 with 50 MeV pions

    Energy Technology Data Exchange (ETDEWEB)

    Applegate, J M

    1993-03-01

    In the first experiment to use the superconducting RF cavity at LAMPF known as the Scruncher, cross sections have been measured for the 1+ doublet in {sup 12}C by 50 MeV {pi}r{sup {plus_minus}} scattering. The cross section ratio of the isoscalar to the isovector states was found to be 6.8 {plus_minus} 1.3 for {pi}{sup +}+ scattering and 3.9 {plus_minus} 1.4 for {pi}{sup {minus}} scattering. These ratios give an isospin mixing matrix element H{sub 01}, of 119 {plus_minus} 40 key, in good agreement with the average value of 123 {plus_minus} 26 key deduced from previous pion-scattering data and with values deduced from other probes. The ratio of {pi}{sup +} + p to {pi}{sup {minus}} + p cross sections was determined experimentally to be 2.60 {plus_minus} 0.11, in agreement with a theoretical value of 2.85. The agreement of these results indicates that the impulse approximation is valid at 50 MeV. Cross sections were also measured for the elastic and collective states in {sup 12}C and were generally described well by distorted wave Born approximation calculations published previously.

  11. Effects of carbon source and carbon content on electrochemical performances of Li{sub 4}Ti{sub 5}O{sub 12}/C prepared by one-step solid-state reaction

    Energy Technology Data Exchange (ETDEWEB)

    Hu Xuebu [College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, Sichuan 610066 (China); Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, Sichuan 610041 (China); Lin Ziji [China National Quality Supervision and Inspection Center for Alcoholic Beverage Products and Processed Food, Luzhou, Sichuan 646100 (China); Yang Kerun [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, Sichuan 610041 (China); Hua, Yongjian [China Aviation Lithium Battery Co. Ltd., Luoyang, Henan 471009 (China); Deng Zhenghua, E-mail: zhdeng@cioc.ac.cn [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, Sichuan 610041 (China)

    2011-05-30

    Highlights: > A simple route to prepare the Li{sub 4}Ti{sub 5}O{sub 12}/C by one-step solid-state reaction. > Carbon source and carbon content are two important factors on the electrochemical performances of Li{sub 4}Ti{sub 5}O{sub 12}/C. > As-prepared Li{sub 4}Ti{sub 5}O{sub 12}/C under optimized conditions shows excellent electrochemical performances. - Abstract: Li{sub 4}Ti{sub 5}O{sub 12}/C composites were synthesized by one-step solid-state reaction method using four commonly used organic compounds or organic polymers as carbon source, i.e., polyacrylate acid (PAA), citric acid (CA), maleic acid (MA) and polyvinyl alcohol (PVA). The physical characteristics of Li{sub 4}Ti{sub 5}O{sub 12}/C composites were investigated by X-ray diffraction, electron microscopy, Raman spectroscopy, particle size distribution and thermogravimetry-derivative thermogravimetry techniques. Their electrochemical properties were characterized by cyclic voltammograms, electrochemical impedance spectra, constant current charge-discharge and rate charge-discharge. These analyses indicated that the carbon source and carbon content have a great effect on the physical and electrochemical performances of Li{sub 4}Ti{sub 5}O{sub 12}/C composites. An ideal carbon source and appropriate carbon content effectively improved the electrical contact between the Li{sub 4}Ti{sub 5}O{sub 12} particles, which enhanced the discharge capacity and rate capability of Li{sub 4}Ti{sub 5}O{sub 12}/C composites. PAA was the best carbon source for the synthesis of Li{sub 4}Ti{sub 5}O{sub 12}/C composites. When the carbon content was 3.49 wt.% (LiOH.H{sub 2}O/PAA molar ratio of 1), as-prepared Li{sub 4}Ti{sub 5}O{sub 12}/C showed the maximum discharge capacity. At 0.2 C, initial capacity of the optimized sample was 168.6 mAh g{sup -1} with capacity loss of 2.8% after 50 cycles. At 8 and 10 C, it showed discharge capacities of 143.5 and 132.7 mAh g{sup -1}, with capacity loss of 8.7 and 9.9% after 50 cycles

  12. Cryogenic optical measurements of 12-segment-bonded carbon-fiber-reinforced silicon carbide composite mirror with support mechanism

    Science.gov (United States)

    Kaneda, Hidehiro; Nakagawa, Takao; Onaka, Takashi; Enya, Keigo; Makiuti, Sin'itirou; Takaki, Junji; Haruna, Masaki; Kume, Masami; Ozaki, Tsuyoshi

    2008-03-01

    A 720 mm diameter 12-segment-bonded carbon-fiber-reinforced silicon carbide (C/SiC) composite mirror has been fabricated and tested at cryogenic temperatures. Interferometric measurements show significant cryogenic deformation of the C/SiC composite mirror, which is well reproduced by a model analysis with measured properties of the bonded segments. It is concluded that the deformation is due mostly to variation in coefficients of thermal expansion among segments. In parallel, a 4-degree-of-freedom ball-bearing support mechanism has been developed for cryogenic applications. The C/SiC composite mirror was mounted on an aluminum base plate with the support mechanism and tested again. Cryogenic deformation of the mirror attributed to thermal contraction of the aluminum base plate via the support mechanism is highly reduced by the support, confirming that the newly developed support mechanism is promising for its future application to large-aperture cooled space telescopes.

  13. Short-range correlations in carbon-12, oxygen-16, and neon-20: Intrinsic properties

    Science.gov (United States)

    Braley, R. C.; Ford, W. F.; Becker, R. L.; Patterson, M. R.

    1972-01-01

    The Brueckner-Hartree-Fock (BHF) method has been applied to nuclei whose intrinsic structure is nonspherical. Reaction matrix elements were calculated as functions of starting energy for the Hamada-Johnston interaction using the Pauli operator appropriate to O-16 and a shifted oscillator spectrum for virtual excited states. Binding energies, single particle energies, radii, and shape deformations of the intrinsic state, in ordinary as well as renormalized BHF, are discussed and compared with previous HF studies and with experiment when possible. Results are presented for C-12, 0-16 and Ne-20. It is found that the binding energies and radii are too small, but that separation energies are well reproduced when the renormalized theory is used.

  14. Black carbon record of the wildfire history of western Sichuan Province in China over the last 12.8 ka

    Science.gov (United States)

    Sun, Weiwei; Zhang, Enlou; Shen, Ji; Chen, Rong; Liu, Enfeng

    2016-01-01

    Wildfire is recognized as a critical Earth system process which affects the global carbon cycle, atmospheric chemistry, and ecosystem dynamics. Estimating the potential impact of future climate change on the incidence of fire requires an understanding of the long-term interactions of fire, climate, vegetation, and human activity. Accordingly, we analyzed the black carbon content and the pollen stratigraphy of sediments spanning the past 12.8 ka from Lake Muge Co, an alpine lake in western Sichuan Province, in order to determine the main factors influencing regional fire regimes. The results demonstrate that wildfires occurred frequently and intensively during the late deglaciation and the early Holocene when the regional vegetation was dominated by deciduous forests. Wildfire occurrence decreased significantly during the Holocene climatic optimum between 9.2 and 5.6 cal ka BP. Overall, the wildfire history of western Sichuan Province is similar to that of the Chinese Loess Plateau and of East Asia as a whole, suggesting that regional-scale fires depended mainly on changes in the intensity of the Asian summer monsoon. In addition, the fire regime of western Sichuan Province may have been influenced by the establishment of human settlement and agriculture in western Sichuan Province and the southeastern Tibetan Plateau after about 5.5 cal ka BP, and by an intensification of cereal cultivation coupled with population expansion in southwestern China during the last two millennia.

  15. Partitioning sources of recharge in environments with groundwater recirculation using carbon-14 and CFC-12

    Science.gov (United States)

    Bourke, Sarah A.; Cook, Peter G.; Dogramaci, Shawan; Kipfer, Rolf

    2015-06-01

    Groundwater recirculation occurs when groundwater is pumped from an aquifer onto the land surface, and a portion of that water subsequently infiltrates back to the aquifer. In environments where groundwater is recirculated, differentiation between various sources of recharge (e.g. natural rainfall recharge vs. recirculated water) can be difficult. Groundwater age indicators, in particular transient trace gases, are likely to be more sensitive tracers of recharge than stable isotopes or chloride in this setting. This is because, unlike stable isotopes or chloride, they undergo a process of equilibration with the atmosphere, and historical atmospheric concentrations are known. In this paper, groundwater age indicators (14C and CFC-12) were used as tracers of recharge by surplus mine water that is discharged to streams. Ternary mixing ratios were calculated based on 14C and CFC-12 concentrations measured along three transects of piezometers and monitoring wells perpendicular to the creeks, and from dewatering wells. Uncertainty in calculated mixing ratios was estimated using a Monte Carlo approach. Ternary mixing ratios in dewatering wells suggest that recharge by mine water accounted for between 10% and 87% of water currently abstracted by dewatering wells. The calculated mixing ratios suggest that recharge by mine water extends to a distance of more than 550 m from the creeks. These results are supported by seepage flux estimates based on the water and chloride balance along the creeks, which suggest that 85-90% of mine water discharged to the creeks recharges the aquifer and recharge by mine water extends between 110 and 730 m from the creeks. Mixing calculations based on gaseous groundwater age indicators could also be used to partition recharge associated with agricultural irrigation or artificial wetland supplementation.

  16. FY12 ARRA-NRAP Report – Studies to Support Risk Assessment of Geologic Carbon Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, Kirk J.; Shao, Hongbo; Thompson, C. J.; Zhong, Lirong; Jung, Hun Bok; Um, Wooyong

    2011-09-27

    This report summarizes results of research conducted during FY2012 to support the assessment of environmental risks associated with geologic carbon dioxide (CO2) sequestration and storage. Several research focus areas are ongoing as part of this project. This includes the quantification of the leachability of metals and organic compounds from representative CO2 storage reservoir and caprock materials, the fate of metals and organic compounds after release, and the development of a method to measure pH in situ under supercritical CO2 (scCO2) conditions. Metal leachability experiments were completed on 6 different rock samples in brine in equilibrium with scCO2 at representative geologic reservoir conditions. In general, the leaching of RCRA metals and other metals of concern was found to be limited and not likely to be a significant issue (at least, for the rocks tested). Metals leaching experiments were also completed on 1 rock sample with scCO2 containing oxygen at concentrations of 0, 1, 5, and 10% to simulate injection of CO2 originating from the oxy-fuel combustion process. Significant differences in the leaching behavior of certain metals were observed when oxygen is present in the CO2. These differences resulted from oxidation of sulfides, release of sulfate, ferric iron and other metals, and subsequent precipitation of iron oxides and some sulfates such as barite. Experiments to evaluate the potential for mobilization of organic compounds from representative reservoir materials and cap rock and their fate in porous media (quartz sand) have been conducted. Results with Fruitland coal and Gothic shale indicate that lighter organic compounds were more susceptible to mobilization by scCO2 compared to heavier compounds. Alkanes demonstrated very low extractability by scCO2. No significant differences were observed between the extractability of organic compounds by dry or water saturated scCO2. Reaction equilibrium appears to have been reached by 96 hours. When

  17. Influence of different carbon sources on exopolysaccharide production by Lactobacillus delbrueckii subsp. bulgaricus (B3, G12 and Streptococcus thermophilus (W22

    Directory of Open Access Journals (Sweden)

    Zehra Nur Yuksekdag

    2008-06-01

    Full Text Available Exopolysaccharides (EPSs production was studied by Lactobacillus delbrueckii subsp. bulgaricus (B3, G12 and Streptococcus thermophilus (W22 in the medium containing various carbon sources (glucose, fructose, sucrose or lactose. For all the strains, glucose was the most efficient carbon source and B3, G12 and W22 strains produced 211, 175 and 120 EPS mg/L respectively. Also, the influence of different concentrations of glucose (5,10,15,20,25,30 g/L on EPS production and growth was studied. The results indicated that EPS production and growth were stimulated by the high glucose concentration (30 g/L.

  18. Investigation of carbon-coated lithiated Li{sub 4+x}Ti{sub 5}O{sub 12}/C for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Mengjie; Zhang, Lin; Gong, Lijun; Liu, Hongbo; Chen, Yuxi, E-mail: yxchen@hnu.edu.cn

    2015-11-15

    Highlights: • Lithiated Li{sub 4+x}Ti{sub 5}O{sub 12}/C with pre-stored active Li ions has been synthesized. • The first-cycle coulombic efficiency of Li{sub 4+x}Ti{sub 5}O{sub 12}/C is over 100%. • Li{sub 4+x}Ti{sub 5}O{sub 12}/C displays excellent cyclic stability and capacity retention. • TiO{sub 2} nanoparticles and carbon coating are necessary for formation of Li{sub 4+x}Ti{sub 5}O{sub 12}/C. - Abstract: Carbon-coated Li{sub 4}Ti{sub 5}O{sub 12} and lithiated Li{sub 4+x}Ti{sub 5}O{sub 12} anode materials have been synthesized using nanosized anatase TiO{sub 2} and commercial TiO{sub 2} with mixed structure as Ti sources, respectively. Microstructural investigation indicates that Li{sub 4}Ti{sub 5}O{sub 12} and Li{sub 4+x}Ti{sub 5}O{sub 12} are covered by amorphous carbon layers with thickness of 2–3 nm. Their electrochemical performance has been evaluated, which indicates that an amount of active Li ions have been pre-stored in the Li{sub 4+x}Ti{sub 5}O{sub 12} lattice during solid-state synthesis, resulting in its first-cycle coulombic efficiency over 100%. Further, Li{sub 4+x}Ti{sub 5}O{sub 12}/C exhibits higher cyclic capacities than Li{sub 4}Ti{sub 5}O{sub 12}/C at different current density. The reversible charge capacity retention of Li{sub 4+x}Ti{sub 5}O{sub 12}/C reaches 98.5% after 100 cycles, which indicates that Li{sub 4+x}Ti{sub 5}O{sub 12}/C is promising candidate anode material for long lifetime lithium-ion batteries. The formation mechanism of Li{sub 4+x}Ti{sub 5}O{sub 12}/C has been discussed, in which the nanosized anatase TiO{sub 2} with high chemical activity and the carbon coating play key roles for the formation of Li{sub 4+x}Ti{sub 5}O{sub 12}/C.

  19. Metal-Free Oxidation of α-Hydroxy Ketones to 1,2-Diketones Catalyzed by Mesoporous Carbon Nitride with Visible Light

    Institute of Scientific and Technical Information of China (English)

    郑志硕; 周小松

    2012-01-01

    As a photocatalyst, mesoporous carbon nitride (mpg-C3N4) shows higher photocatalytic activities in organic synthesis. Herein we report an mpg-C3N4-catalyzed oxidation of α-hydroxy ketones to synthesize 1,2-diketones using visible light. This transformation represents a green and highly efficient synthetic route to synthesize 1,2-diketones for which catalytic approaches are scarce.

  20. Stable carbon isotope fractionation of trans-1,2-dichloroethylene during co-metabolic degradation by methanotrophic bacteria

    Science.gov (United States)

    Brungard, K.L.; Munakata-Marr, J.; Johnson, C.A.; Mandernack, K.W.

    2003-01-01

    Changes in the carbon isotope ratio (??13C) of trans-1,2-dichloroethylene (t-DCE) were measured during its co-metabolic degradation by Methylomonas methanica, a type I methanotroph, and Methylosinus trichosporium OB3b, a type II methanotroph. In closed-vessel incubation experiments with each bacterium, the residual t-DCE became progressively enriched in 13C, indicating isotopic fractionation. From these experiments, the biological fractionation during t-DCE co-metabolism, expressed as ??, was measured to be -3.5??? for the type I culture and -6.7??? for the type II culture. This fractionation effect and subsequent enrichment in the ??13C of the residual t-DCE can thus be applied to determine the extent of biodegradation of DCE by these organisms. Based on these results, isotopic fractionation clearly warrants further study, as measured changes in the ??13C values of chlorinated solvents could ultimately be used to monitor the extent of biodegradation in laboratory or field settings where co-metabolism by methanotrophs occurs. ?? 2002 Elsevier Science B.V. All rights reserved.

  1. Melting Relations of Multicomponent Carbonate System MgCO3 - FeCO3- CaCO3- Na2CO3 at 12-23 GPa

    Science.gov (United States)

    Spivak, Anna; Solopova, Natalia; Litvin, Yuriy; Dubrovinsky, Leonid; Zakharchenko, Egor

    2014-05-01

    Considerable attention is focused on high-pressure high-temperature experimental study of melting phase relations of carbonates which were involved into a 'super-deep' diamond genesis. High-pressure stability of carbonate melts and their role in 'ultra-deep' diamonds genesis are most essential. Experimental study of melting relations of multicomponent carbonate system was carried out using multi-anvil press at the pressures 12 - 23 GPa and temperatures 800 to 1650 oC. Chemical compositions of starting carbonate system used for melting experiment were prepared by mixing: FeCO3 - 26,00; MgCO3- 26,00; CaCO3 - 25,00; Na2CO3 - 23,00 wt %. A region of partial melting for the system is experimentally determined. The partial melting field is arranged between low-temperature boundary of eutectics melting (solidus line) of the multicomponent carbonate and the boundary of complete melting (liquidus line) at higher temperature. From experimental observations, a Mg-Fe carbonate solid solution is the liquidus phase. At temperature lowering, the assemblage (Mg,Fe)CO3 + (Ca,Na2,Fe)CO3 + L (liquid) is formed. Then, the invariant eutectic assemblage (Mg,Fe)CO3 + (Ca,Na2,Fe)CO3 + Na2(Ca,Fe)(CO3)2+ L (liquid) which is determining for subsolidus assemblage (Mg,Fe)CO3 + (Ca,Na2,Fe)CO3 + Na2(Ca,Fe)(CO3)2 is formed. Next to liquidus line is one-phase field of completely miscible multicomponent carbonate melt. On the whole, the results demonstrate phase relations of solid carbonates and multicomponent carbonate liquid in the immediate vicinity to the low-temperature melting boundary. The early melting of the multicomponent carbonate system is compatible with the lower mantle geothermal conditions because the primary melting temperatures are noticeably below than the geothermal values. It is significant that multicomponent carbonate melts are stable and completely miscible under conditions as partial so complete melting. Thus, high-pressure high-temperature experimental data demonstrate

  2. Pyrolysis of Animal Bones with Vitamin B12: A Facile Route to Efficient Transition Metal-Nitrogen-Carbon (TM-N-C) Electrocatalysts for Oxygen Reduction.

    Science.gov (United States)

    Dou, Meiling; He, Duanpeng; Shao, Wenhao; Liu, Haijing; Wang, Feng; Dai, Liming

    2016-02-24

    By pyrolyzing cattle bones, hierarchical porous carbon (HPC) networks with a high surface area (2520 m(2)  g(-1) ) and connected pores were prepared at a low cost and large scale. Subsequent co-pyrolysis of HPC with vitamin B12 resulted in the formation of three-dimensional (3D) hierarchically structured porous cobalt-nitrogen-carbon (Co-N-HPC) electrocatalysts with a surface area as high as 859 m(2)  g(-1) as well as a higher oxygen reduction reaction (ORR) electrocatalytic activity, better operation stability, and higher tolerance to methanol than the commercial Pt/C catalyst in alkaline electrolyte.

  3. Spray drying of spherical Li{sub 4}Ti{sub 5}O{sub 12}/C powders using polyvinyl pyrrolidone as binder and carbon source

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wei [Research Center for New Energy Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); University of Chinese Academy of Sciences, Beijing 110049 (China); Shanghai Nanotechnology Promotion Center, Shanghai 200237 (China); Wang, Qian; Cao, Chunhui [Research Center for New Energy Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); University of Chinese Academy of Sciences, Beijing 110049 (China); Han, Xuewu [Research Center for New Energy Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Zhang, Jian, E-mail: zjskycn@163.com [Research Center for New Energy Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Xie, Xiaohua, E-mail: xiaohuaxie@126.com [Research Center for New Energy Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Xia, Baojia [Research Center for New Energy Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); University of Chinese Academy of Sciences, Beijing 110049 (China)

    2015-02-05

    Highlights: • The spherical Li{sub 4}Ti{sub 5}O{sub 12}/C granules were prepared by spray drying. • Polyvinyl pyrrolidone (PVP) was used as binder and carbon source. • Tap density and spherical structure increase with the increase of PVP content. • Li{sub 4}Ti{sub 5}O{sub 12}/C granules exhibits better rate capability and excellent cyclability. - Abstract: Polyvinyl pyrrolidone (PVP) was used as binder and carbon source to synthesize stable and spherical Li{sub 4}Ti{sub 5}O{sub 12}/C granules by spray drying. The effects of PVP content and atmospheres on the properties of Li{sub 4}Ti{sub 5}O{sub 12} were investigated. The obtained samples were characterized by X-ray diffraction, scanning electron microscopy, Raman spectroscopy, and electrochemical tests, respectively. The results indicate that the average particle size, tap density and degree of spherical structure increase accordingly to the increase of PVP content. However, the large secondary particle would deteriorate the rate capacity at high current density. The carbon coating could significantly improve the rate capacity, which is attributed to the smaller primary particle and higher electrical conductivity.

  4. Measurement of fragment production DDX of 72 and 144 MeV 12C beam induced reaction on carbon using Bragg Curve Counter

    International Nuclear Information System (INIS)

    Double differential cross section (DDX) data of fragment production for 72 (6 MeV/nucleon) and 144 MeV (12 MeV/nucleon) 12C beam induced reaction on carbon were measured using a Bragg Curve Counter (BCC). The DDX data were obtained for fragments of He, Li, Be, B, C, N and O at 30 degree emission angle. Theoretical calculation using PHITS code with QMD+GEM model represents the DDX well except for components from reactions of direct process and α particle clustering process. (author)

  5. Acetohydroxy acid synthase I, a required enzyme for isoleucine and valine biosynthesis in Escherichia coli K-12 during growth on acetate as the sole carbon source.

    OpenAIRE

    Dailey, F E; Cronan, J E

    1986-01-01

    Escherichia coli K-12 has two acetohydroxy acid synthase (AHAS) isozymes (AHAS I and AHAS III). Both of these isozymes catalyze the synthesis of alpha-aceto-alpha-hydroxybutyrate and alpha-acetolactate, which are key intermediates of the isoleucine-valine biosynthetic pathway. Strains lacking either isozyme but not both activities have been previously shown to grow well in minimal media in the absence of isoleucine and valine on any of several commonly used carbon sources (e.g., glucose or su...

  6. A novel method based on selective laser sintering for preparing high-performance carbon fibres/polyamide12/epoxy ternary composites.

    Science.gov (United States)

    Zhu, Wei; Yan, Chunze; Shi, Yunsong; Wen, Shifeng; Liu, Jie; Wei, Qingsong; Shi, Yusheng

    2016-01-01

    A novel method based on selective laser sintering (SLS) process is proposed for the first time to prepare complex and high-performance carbon fibres/polyamide12/epoxy (CF/PA12/EP) ternary composites. The procedures are briefly described as follows: prepare polyamide12 (PA12) coated carbon fibre (CF) composite powder; build porous green parts by SLS; infiltrate the green parts with high-performance thermosetting epoxy (EP) resin; and finally cure the resin at high temperature. The obtained composites are a ternary composite system consisting of the matrix of novolac EP resin, the reinforcement of CFs and the transition thin layer of PA12 with a thickness of 595 nm. The SEM images and micro-CT analysis prove that the ternary system is a three-dimensional co-continuous structure and the reinforcement of CFs are well dispersed in the matrix of EP with the volume fraction of 31%. Mechanical tests show that the composites fabricated by this method yield an ultimate tensile strength of 101.03 MPa and a flexural strength of 153.43 MPa, which are higher than those of most of the previously reported SLS materials. Therefore, the process proposed in this paper shows great potential for manufacturing complex, lightweight and high-performance CF reinforced composite components in aerospace, automotive industries and other areas. PMID:27650254

  7. A novel method based on selective laser sintering for preparing high-performance carbon fibres/polyamide12/epoxy ternary composites.

    Science.gov (United States)

    Zhu, Wei; Yan, Chunze; Shi, Yunsong; Wen, Shifeng; Liu, Jie; Wei, Qingsong; Shi, Yusheng

    2016-09-21

    A novel method based on selective laser sintering (SLS) process is proposed for the first time to prepare complex and high-performance carbon fibres/polyamide12/epoxy (CF/PA12/EP) ternary composites. The procedures are briefly described as follows: prepare polyamide12 (PA12) coated carbon fibre (CF) composite powder; build porous green parts by SLS; infiltrate the green parts with high-performance thermosetting epoxy (EP) resin; and finally cure the resin at high temperature. The obtained composites are a ternary composite system consisting of the matrix of novolac EP resin, the reinforcement of CFs and the transition thin layer of PA12 with a thickness of 595 nm. The SEM images and micro-CT analysis prove that the ternary system is a three-dimensional co-continuous structure and the reinforcement of CFs are well dispersed in the matrix of EP with the volume fraction of 31%. Mechanical tests show that the composites fabricated by this method yield an ultimate tensile strength of 101.03 MPa and a flexural strength of 153.43 MPa, which are higher than those of most of the previously reported SLS materials. Therefore, the process proposed in this paper shows great potential for manufacturing complex, lightweight and high-performance CF reinforced composite components in aerospace, automotive industries and other areas.

  8. A novel method based on selective laser sintering for preparing high-performance carbon fibres/polyamide12/epoxy ternary composites

    Science.gov (United States)

    Zhu, Wei; Yan, Chunze; Shi, Yunsong; Wen, Shifeng; Liu, Jie; Wei, Qingsong; Shi, Yusheng

    2016-01-01

    A novel method based on selective laser sintering (SLS) process is proposed for the first time to prepare complex and high-performance carbon fibres/polyamide12/epoxy (CF/PA12/EP) ternary composites. The procedures are briefly described as follows: prepare polyamide12 (PA12) coated carbon fibre (CF) composite powder; build porous green parts by SLS; infiltrate the green parts with high-performance thermosetting epoxy (EP) resin; and finally cure the resin at high temperature. The obtained composites are a ternary composite system consisting of the matrix of novolac EP resin, the reinforcement of CFs and the transition thin layer of PA12 with a thickness of 595 nm. The SEM images and micro-CT analysis prove that the ternary system is a three-dimensional co-continuous structure and the reinforcement of CFs are well dispersed in the matrix of EP with the volume fraction of 31%. Mechanical tests show that the composites fabricated by this method yield an ultimate tensile strength of 101.03 MPa and a flexural strength of 153.43 MPa, which are higher than those of most of the previously reported SLS materials. Therefore, the process proposed in this paper shows great potential for manufacturing complex, lightweight and high-performance CF reinforced composite components in aerospace, automotive industries and other areas. PMID:27650254

  9. Quarterly Report for LANL Activities: FY12-Q2 National Risk Assessment Partnership (NRAP): Industrial Carbon Capture Program

    Energy Technology Data Exchange (ETDEWEB)

    Pawar, Rajesh J. [Los Alamos National Laboratory

    2012-04-17

    This report summarizes progress of LANL activities related to the tasks performed under the LANL FWP FE102-002-FY10, National Risk Assessment Partnership (NRAP): Industrial Carbon Capture Program. This FWP is funded through the American Recovery and Reinvestment Act (ARRA). Overall, the NRAP activities are focused on understanding and evaluating risks associated with large-scale injection and long-term storage of CO{sub 2} in deep geological formations. One of the primary risks during large-scale injection is due to changes in geomechanical stresses to the storage reservoir, to the caprock/seals and to the wellbores. These changes may have the potential to cause CO{sub 2} and brine leakage and geochemical impacts to the groundwater systems. While the importance of these stresses is well recognized, there have been relatively few quantitative studies (laboratory, field or theoretical) of geomechanical processes in sequestration systems. In addition, there are no integrated studies that allow evaluation of risks to groundwater quality in the context of CO{sub 2} injection-induced stresses. The work performed under this project is focused on better understanding these effects. LANL approach will develop laboratory and computational tools to understand the impact of CO{sub 2}-induced mechanical stress by creating a geomechanical test bed using inputs from laboratory experiments, field data, and conceptual approaches. The Geomechanical Test Bed will be used for conducting sensitivity and scenario analyses of the impacts of CO{sub 2} injection. The specific types of questions will relate to fault stimulation and fracture inducing stress on caprock, changes in wellbore leakage due to evolution of stress in the reservoir and caprock, and the potential for induced seismicity. In addition, the Geomechanical Test Bed will be used to investigate the coupling of stress-induced leakage pathways with impacts on groundwater quality. LANL activities are performed under two tasks

  10. Carbon dioxide adsorption on micro-mesoporous composite materials of ZSM-12/MCM-48 type: The role of the contents of zeolite and functionalized amine

    Energy Technology Data Exchange (ETDEWEB)

    Santos, S.C.G. [Federal University of Sergipe, Materials Science and Engineering Postgraduate Program P" 2CEM, São Cristovão/SE (Brazil); Pedrosa, A.M.Garrido [Federal University of Sergipe, Departament of Chemistry (DQI), São Cristovão/SE (Brazil); Souza, M.J.B., E-mail: mjbsufs@gmail.com [Federal University of Sergipe, Department of Chemical Engineering (DEQ), Av. Marechal Rondon S/N, 49100-000, São Cristovão/SE (Brazil); Cecilia, J.A.; Rodríguez-Castellón, E. [University of Málaga, Department of Inorganic Chemistry, Crystallography and Mineralogy, Faculty of Sciences, 29071, Málaga (Spain)

    2015-10-15

    Highlights: • Synthesis of the micro-mesoporous composite materials of ZSM-12/MCM-48 type. • Application of these adsorbents in the carbon dioxide adsorption. • Effects of the contents of zeolite and amino group in the material surface on the CO{sub 2} capture efficiency. - Abstract: In this study ZSM-12/MCM-48 adsorbents have been synthesized at three ZSM-12 content, and also were functionalizated with amine groups by grafting. All the adsorbents synthesized were evaluated for CO{sub 2} capture. The X-ray diffraction analysis of the ZSM-12/MCM-48 composite showed the main characteristic peaks of ZSM-12 and MCM-48, and after the functionalization, the structure of MCM-48 on the composite impregnated was affected due amine presence. For the composites without amine, the ZSM-12 content was the factor determining in the adsorption capacity of CO{sub 2} and for the composites with amine the amount of amine was that influenced in the adsorption capacity.

  11. Effects of niobium addition on the structure and properties of medium and high carbon steels. v. 1,2

    International Nuclear Information System (INIS)

    An evaluation about the use of niobium in medium and high carbon steels, with ferritic-pearlitic structure, through the understanding of niobium actuaction mechanism in the structure, and consequently in the mechanical properties of those steels is done. (E.G.)

  12. Towards understanding the effects of carbon and nitrogen-doped carbon coating on the electrochemical performance of Li4Ti5O12 in lithium ion batteries: a combined experimental and theoretical study.

    Science.gov (United States)

    Ding, Zijing; Zhao, Liang; Suo, Liumin; Jiao, Yang; Meng, Sheng; Hu, Yong-Sheng; Wang, Zhaoxiang; Chen, Liquan

    2011-09-01

    We investigate the effects of carbon coating, with and without nitrogen-dopants, on the electrochemical performance of a promising anode material Li(4)Ti(5)O(12) (LTO) in lithium ion battery applications. The comparative experimental results show that LTO samples coated with nitrogen-doped carbon derived from pyridine and an ionic liquid exhibit significant improvements in rate capability and cycling performance compared with a LTO sample coated by carbon derived from toluene and the pristine LTO sample. For the first time, we construct an atomistic model for the interface between the lithium transition metal oxide and carbon coating layers. Our first-principles calculations based on density functional theory reveal that at this interface there is strong binding between the graphene coating layer and the Ti-terminated LTO surface, which significantly reduces the chemical activity of LTO surfaces and stabilizes the electrode/electrolyte interface, providing a clue to solve the swelling problem for LTO-based batteries. More importantly, electron transfer from the LTO surface to graphene greatly improves the electric conductivity of the interface. Nitrogen-dopants in graphene coatings further increase the interfacial stability and electric conductivity, which is beneficial to the electrochemical performance in energy storage applications.

  13. Effect of carbon and niobium on the microstructure and impact toughness of a high silicon 12% Cr ferritic/martensitic heat resistant steel

    International Nuclear Information System (INIS)

    In order to guide the design of 9–12% Cr ferritic/martensitic (F/M) heat resistant steels appropriate for use in accelerator-driven system, the impact toughness and behavior of precipitation of a 12% Cr F/M heat resistant steel containing high C and Si concentrations have been investigated. Particular focus has been given to the interaction of carbon and carbonitride-forming element. Because of the presence of primary NbC and a large amount of M23C6, the impact toughness of the investigated steel was much lower than that of the commercial 9–12% Cr F/M heat resistant steels. The primary NbC crystallizes directly from liquid metal when the Nb concentration is higher than a critical value. The critical value of Nb decreases with increase in the carbon concentration. In addition, the higher content and faster precipitation kinetics of M23C6 in the investigated steel during the tempering heat treatment also lowers the impact toughness

  14. Effect of carbon and niobium on the microstructure and impact toughness of a high silicon 12% Cr ferritic/martensitic heat resistant steel

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Zhongfei [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Wang, Pei, E-mail: pwang@imr.ac.cn [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Li, Dianzhong [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Zhang, Yutuo [Shenyang Ligong University, 6 Nanping Road, Shenyang 110159 (China); Li, Yiyi [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China)

    2014-10-20

    In order to guide the design of 9–12% Cr ferritic/martensitic (F/M) heat resistant steels appropriate for use in accelerator-driven system, the impact toughness and behavior of precipitation of a 12% Cr F/M heat resistant steel containing high C and Si concentrations have been investigated. Particular focus has been given to the interaction of carbon and carbonitride-forming element. Because of the presence of primary NbC and a large amount of M{sub 23}C{sub 6}, the impact toughness of the investigated steel was much lower than that of the commercial 9–12% Cr F/M heat resistant steels. The primary NbC crystallizes directly from liquid metal when the Nb concentration is higher than a critical value. The critical value of Nb decreases with increase in the carbon concentration. In addition, the higher content and faster precipitation kinetics of M{sub 23}C{sub 6} in the investigated steel during the tempering heat treatment also lowers the impact toughness.

  15. Measurements of the viscosity of carbon dioxide at temperatures from (253.15 to 473.15) K with pressures up to 1.2 MPa

    International Nuclear Information System (INIS)

    Highlights: • A new rotating-body viscometer for the low-pressure region was presented. • A viscosity dependent offset was compensated by calibrating the viscometer. • The viscosity of carbon dioxide was measured at low pressures. • Measurements were carried out from T = (253.15 to 473.15) K with p ≤ 1.2 MPa. • The relative expanded combined uncertainty (k = 2) was Ur,c(η) = (0.20 to 0.41)%. - Abstract: The viscosity of carbon dioxide was measured over the temperature range T = (253.15 to 473.15) K with pressures up to 1.2 MPa utilizing a new rotating-body viscometer. The relative expanded combined uncertainty (k = 2) in viscosity (including uncertainties of temperature and pressure) was (0.20 to 0.41)%. The instrument was specifically designed for measurements at low gas densities and enables measurements of the dynamic viscosity at temperatures between T = 253.15 K and T = 473.15 K with pressures up to 2 MPa. For carbon dioxide, the fluid specific measuring range with regard to pressure was limited to 1.2 MPa due to the formation of disturbing vortices inside the measuring cell at higher pressures. The model function for the viscosity measurement was extended in such a way that the dynamic viscosity was measured relative to helium. Therefore, the influence of the geometry of the concentric cylindrical system inside the measuring cell became almost negligible. Moreover, a systematic offset resulting from a small but inevitable eccentricity of the cylindrical system was compensated for. The residual damping, usually measured in vacuum, was calibrated in the entire temperature range using viscosity values of helium, neon and argon calculated ab initio; at T = 298.15 K recommended reference values were used. A viscosity dependent offset of the measured viscosities, which was observed in previously published data, did not occur when using the calibrated residual damping. The new carbon dioxide results were compared to other experimental literature data

  16. Stripping voltammetric determination of Cd(Ⅱ) based on multiwalled carbon nanotube functionalized with 1-(2-pyridylazo)-2-naphthol

    Institute of Scientific and Technical Information of China (English)

    Alireza Mohadesi; Hadi Beitollahi; Mohammad Ali Karimi

    2011-01-01

    The present work has focused on the modification of multiwalled carbon nanotube with a ligand, l-(2-pyridylazo)-2-naphthol, and its potential application for the development of a new, simple and selective modified glassy carbon electrode for stripping voltammetric determination of Cd(Ⅱ). The analytical curve for Cd(Ⅱ) ions covered the linear range varying from 0.8 up to 220.4 μg L-1. The limit of detection was found to be 0.1 μg L-1, while the relative standard deviation (RSD) at 50.0 μg L-1 was 1.8% (n = 5). This modified electrode was successfully applied for determination of Cd(Ⅱ) in some water samples.

  17. Plasma Polymerized Thin Films of Maleic Anhydride and 1,2-methylenedioxybenzene for Improving Adhesion to Carbon Surfaces

    DEFF Research Database (Denmark)

    Drews, Joanna Maria; Goutianos, Stergios; Kingshott, Peter;

    2007-01-01

    Low power 2-phase AC plasma polymerization has been used to surface modify glassy carbon substrates that are used as an experimental model for carbon fibers in reinforced composites. In order to probe the role of carboxylic acid density on the interfacial adhesion strength a combination...... acid are present on the MDOB surface as a result of the fragmentation processes in the plasma. Chemical and physical changes were investigated as a function of plasma power at constant polymerization time. Surface chemistry analysis was perfonned with x-ray photoelectron spectroscopy and attenuated...... total veflectanc~ Fourier transform infrared spectroscopy. Atomic force microscopy was used to measure the thickness of the plasma films and to monitor the surface roughness for the different polymerization conditions. Finally, preliminary results of fracture energy measurements of the plasma modified...

  18. Multi-layer electrode with nano-Li4Ti5O12 aggregates sandwiched between carbon nanotube and graphene networks for high power Li-ion batteries

    Science.gov (United States)

    Choi, Jin-Hoon; Ryu, Won-Hee; Park, Kyusung; Jo, Jeong-Dai; Jo, Sung-Moo; Lim, Dae-Soon; Kim, Il-Doo

    2014-12-01

    Self-aggregated Li4Ti5O12 particles sandwiched between graphene nanosheets (GNSs) and single-walled carbon nanotubes (SWCNTs) network are reported as new hybrid electrodes for high power Li-ion batteries. The multi-layer electrodes are fabricated by sequential process comprising air-spray coating of GNSs layer and the following electrostatic spray (E-spray) coating of well-dispersed colloidal Li4Ti5O12 nanoparticles, and subsequent air-spray coating of SWCNTs layer once again. In multi-stacked electrodes of GNSs/nanoporous Li4Ti5O12 aggregates/SWCNTs networks, GNSs and SWCNTs serve as conducting bridges, effectively interweaving the nanoporous Li4Ti5O12 aggregates, and help achieve superior rate capability as well as improved mechanical stability of the composite electrode by holding Li4Ti5O12 tightly without a binder. The multi-stacked electrodes deliver a specific capacity that maintains an impressively high capacity of 100 mA h g-1 at a high rate of 100C even after 1000 cycles.

  19. Effects of Carbon Sources and Various Chemicals on the Production of a Novel Amylase from a Thermophilic Bacillus sp. K-12

    OpenAIRE

    KIRAN, Özlem; ÇÖMLEKÇİOĞLU, Uğur; Arikan, Burhan

    2005-01-01

    The amylase producer thermophilic Bacillus sp. K-12 was isolated from soil samples from Zeytinli hot spring in Kahramanmaraş. Enzyme synthesis occurred at 20-55 ºC with an optimum of 42 ºC. There was a slight variation in amylase synthesis within the pH range 4.5-10.5. Effects of various carbon sources and chemicals on a-amylase production were examined and maximum a-amylase production was obtained in a medium containing 1% starch in 60 h. MnSO4, ZnSO4 and EDTA inhibited a-amylase production ...

  20. Organic matter turnover in reservoirs of the Harz Mountains (Germany): evidence from 13C/12C changes in dissolved inorganic carbon

    Science.gov (United States)

    Barth, Johannes A. C.; Nenning, Franziska; van Geldern, Robert; Mader, Michael; Friese, Kurt

    2014-05-01

    The Harz Mountains in Germany host several reservoirs for drinking water and electricity supply, the largest of which is the Rappbode System with its two pre-reservoirs. They are the Hassel and the Rappbode pre-reservoirs that have about the same size. These pre-reservoirs were investigated in a comparative study in order to quantify turnover of dissolved organic carbon (DOC) as a representative for organic matter. The objective was to find out how organic matter turnover in these reservoirs may affect dissolved inorganic carbon (DIC) and related CO2 dynamics. Depth profiles of dissolved organic and inorganic carbon (DOC and DIC) were established together with their carbon stable isotope distributions (expressed as δ13CDIC and δ13CDOC). Our results showed up to 104 % increase of DIC contents by organic matter turnover when calculated via isotope mass balances. This contrasted observations of DIC concentration differences between waters collected at the surface and at 12 m depth. These concentration comparisons showed much less DIC increases, and in some cases even decreases, between surface and bottom waters. Such discrepancies could be explained by formation of CO2 at depths below the photic zone that reached calculated values above 7000 ppmV. Such high CO2 concentrations may have reduced the DIC pool by upwards migration. Despite such a concentration decrease, turnover of organic matter has likely incorporated its isotope signal into the DIC pool. While not all DOC present was transposed to DIC, other forms of organic matter from sediments may also have transferred their isotope ratio on the DIC pool. However, with its stable isotope ratio of -28.5 permille the measured DOC was representative of C3 plants and can be assumed as a proxy for other forms of sedimentary carbon including carbon from pore waters and particulate organic matter. Other carbon turnover, including DOC leaching, increased import to the reservoirs after precipitation events and

  1. Effect of carbon content on carbide morphology and mechanical properties of A.R. white cast iron with 10-12% tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Heydari, D. [Department of Materials Science and Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Skandani, A. Alipour [Department of Engineering Science and Mechanics, Virginia Tech, Blacksburg, VA 24061 (United States); Al Haik, M., E-mail: alhaik@vt.edu [Department of Engineering Science and Mechanics, Virginia Tech, Blacksburg, VA 24061 (United States)

    2012-04-30

    Highlights: Black-Right-Pointing-Pointer Effect of W and C variation in A.R. white cast iron was studied up to 12 wt% W. It never exceeded 10 wt% in previous investigations. Black-Right-Pointing-Pointer Carbide morphologies with 2.2-3.2 wt% carbon shows that W has dominating effect on carbide morphology. Black-Right-Pointing-Pointer New carbide microstructures (GA and IA) appear in some range of carbon and its volume fraction is function of carbon content. Black-Right-Pointing-Pointer After heat treatment, new carbide morphology turns to continuous chromium carbide. Black-Right-Pointing-Pointer Wear resistance and hardness of the new alloys depends on both IA appearance presence and tungsten carbide precipitation. - Abstract: Carbide morphologies of white cast iron containing 22% Cr and 10-12% tungsten with different carbon contents (2.34-3.20 wt.%) were investigated. Results indicated that for the as-cast alloys with no heat treatments, the addition of carbon changes the morphology of carbides during air-cooling in the presence of tungsten. Light microscopy analysis revealed that for an alloy with 2.3 wt% carbon, chromium carbides possess coarse gray appearance (GA). Increasing the carbon content reduced the coarse GA zones volume fraction while a finer GA zones emerged. The coexistence of coarse and fine GA phases came to an end at 2.8 wt% carbon, at which only fine GA zones spread throughout the chromium carbide phase. Scaling up the carbon content to 3.2 wt% led to the formation of tungsten carbide and austenite in a eutectic reaction. Both fine and coarse GA zones vanished while the tungsten carbides acquired fishbone-like morphology. Upon heat treatment, the coarse GA zones vanished completely and turned into island appearance (IA) of chromium carbide. On the contrary, the finer GA zones remained unchanged after heat treatment and they coexisted with the IA. After heat treatment, the fishbone morphology shattered apart, however, the hyper chromium carbides

  2. Thick-target neutron, gamma-ray, and radionuclide production for protons below 12 MeV on nickel and carbon beam-stops

    Energy Technology Data Exchange (ETDEWEB)

    Chadwick, M.B.; Young, P.G.; Wilson, W.B.

    1998-03-01

    Nuclear model calculations using the GNASH code are described for protons below 12 MeV incident on nickel and carbon isotopes, for beam stop design in the Los Alamos Accelerator Production of Tritium Low Energy Demonstration Accelerator (LEDA) project. The GNASH calculations apply Hauser-Feshbach and preequilibrium reaction theories and can make use of pre-calculated direct reaction cross sections to low-lying residual nucleus states. From calculated thin target cross sections, thick target 6.7 MeV and 12 MeV proton-induced production of neutrons, gamma rays, and radionuclides are determined. Emission spectra of the secondary neutrons and gamma rays are also determined. The model calculations are validated through comparisons with experimental thin- and thick-target measurements. The results of this work are being utilized as source terms in MCNP analyses for LEDA.

  3. Carbon Isotope Fractionation in Reactions of 1,2-Dibromoethane with FeS and Hydrogen Sulfide

    Science.gov (United States)

    EDB (1,2-dibromoethane) is frequently detected at sites impacted by leaded gasoline. In reducing environments, EDB is highly susceptible to abiotic degradation. A study was conducted to evaluate the potential of compound-specific isotope analysis (CSIA) in assessing abiotic degr...

  4. Large scale micropatterning of multi-walled carbon nanotube/polydimethylsiloxane nanocomposite polymer on highly flexible 12×24 inch substrates

    Science.gov (United States)

    Khosla, A.; Hilbich, D.; Drewbrook, C.; Chung, D.; Gray, B. L.

    2011-03-01

    We present the large scale micro-pattering of an electrically conducting multiwalled carbon nanotube (MWCNT) polydimethylsiloxane (PDMS) nanocomposite polymer prepared by high frequency (42 kHz) ultrasonic agitation of MWCNTs in the PDMS polymer matrix. Large scale micropatterning of the MWCNT-PDMS nanocomposite is achieved via soft lithography employing a 12" × 24" poly-methyl methacrylate (PMMA, commercially known as Plexiglass) micromold. The process has a 20µm minimum feature size. The PMMA micromold is fabricated by laser ablating 5-mm thick, 12" × 24" sheets using the Universal Laser System's VersaLASERlaser cutter system which employs a CO2 laser. We have characterized and compared the resistivity of 1cm × 0.5cm × 0.5cm MWCNT-PDMS structures with varying weight percentage (wt-%) of MWCNT (1-10% wt%) in the PDMS matrix with a result that the percolation threshold is achieved at 2 wt-%. Furthermore, we have demonstrated the ability to fabricate large numbers of microelectrodes with a length of 3.0 cm, width of 500µm, and height of 400µm. The resistivity of these electrodes was found to be equal to 9.93Ωm with a deviation of approximately 10%, indicating uniformity across large areas of the substrate. We have also demonstrated a large scale 12" × 24 hybrid microfabrication process for combining micromolded MWCNT-PDMS nanocomposite microstructures with nonconductive PDMS polymer.

  5. Association constants in solutions of lithium salts in butyrolactone and a mixture of propylene carbonate with 1,2-dimethoxyethane (1 : 1), according to conductometric data

    Science.gov (United States)

    Chernozhuk, T. V.; Sherstyuk, Yu. S.; Novikov, D. O.; Kalugin, O. N.

    2016-02-01

    A conductometric study is performed with solutions of lithium bis(oxalato)borate (LiBOB) in γ-butyrolactone (γ-BL) at 278.15-388.15 K and lithium bis(trifluoromethylsulfonyl)imide (LiTFSI), LiBOB, and lithium tetrafluoroborate (LiBF4) in mixtures of propylene carbonate and 1,2-dimethoxyethane (PC + 1,2-DME) (1 : 1) at 278.15-348.15 K. Limiting molar electrical conductivities (LMECs) and association constants ( K a) in the studied solutions of electrolytes are determined using the Lee-Wheaton equation. The effect temperature, the nature of the solvent, and the properties of the anion have on the conductivity and interparticle interactions in solutions of lithium salts in γ-BL and PC + 1,2-DME (1 : 1) is established. It was concluded that the studied solutions are characterized by low values of their association constants. It was found that the BOB;- anion destroys the structure of the solvent.The thickness of the dynamic solvation shell of ions (Δ R) remains constant for both solvents over the studied range of temperatures, and Δ R is significantly greater for Li+ than for other ions.

  6. Study of Target Fragmentation in the Interaction of 86 MeV/A $^{12}$Carbon with Tantalum, Bismuth and Uranium

    CERN Multimedia

    2002-01-01

    Using radiochemical techniques we will ; a)~~measure the target fragment mass and charge distributions from the interaction of 86~MeV/A |1|2C with Ta, Bi and U; ; b)~~measure the target fragment forward momentum and average kinetic energy using the thick target-thick catcher technique for the above reactions; and ; c)~~measure the target fragment angular and differential energy distributions using thin target-thin catcher techniques for the reactions with Ta and U. \\\\ \\\\ These measurements should allow us to better characterize the transition between low energy and realistic heavy ion reaction mechanisms.

  7. Synthesis of magnetic Pb/Fe304/Si02 and its catalytic activity for propylene carbonate synthesis via urea and 1,2-propylene glycol

    Institute of Scientific and Technical Information of China (English)

    Hualiang AN; Xinqiang ZHAO; Zhiguang JIA; Changcheng WU; Yanji WANG

    2009-01-01

    To facilitate the recovery of Pb/SiO2 catalyst, magnetic Pb/Fe3O4/SiO2 samples were prepared separately by emulsification, sol-gel and incipient impregnation methods. The catalyst samples were characterized by means of X-ray diffraction and N2 adsorption-desorption, and their catalytic activity was investigated in the reaction for synthesizing propylene carbonate from urea and 1,2-propylene glycol. When the gelatin was applied in the preparation of Fe3O4 at 60°C and the pH value was controlled at 4 in the preparation of Fe3O4/SiO2, the Pb/ Fe3O4/SiO2 sample shows good catalytic activity and magnetism. Under the reaction conditions of a reaction temperature of 180°C, reaction time of 2 h, catalyst percentage of 1.7 wt-% and a molar ratio of urea to PG of 1:4, the yield of propylene carbonate attained was 87.7%.

  8. [Effect of accelerated heavy ions of carbon 12C, neon 20Ne and iron 56Fe on the chromosomal apparatus of human blood lymphocytes in vitro].

    Science.gov (United States)

    Repina, L A

    2011-01-01

    Cytogenetic assay of the chromosomal apparatus of human blood lymphocytes was carried out after in vitro irradiation by heavy charged particles with high LET values. Blood plasm samples enriched with lymphocytes were irradiated by accelerated ions of carbon 12C (290 MeV/nucleon and LET = 70 keV/microm), neon 20Ne (400 MeV/nucleon and LET = 70 keV/microm), and iron 56Fe (500 MeV/nucleon and LET = 200 keV/microm) in the dose range from 0.25 to 1 Gy. Rate of chromosome aberrations showed a linear dependence on doses from the densely ionizing radiations with high LET values. Frequency of dicentrics and centric rings in human lymphocytes irradiated by 12C with the energy of 290 MeV/nucleon was maximal at 1 Gy (p < 0.05) relative to the other heavy particles. It was found that relative biological effectiveness of heavy nuclei is several times higher than of 60Co gamma-radiation throughout the range of doses in this investigation.

  9. Large-angle production of charged pions by 3 GeV/c - 12 GeV/c protons on carbon, copper and tin targets

    CERN Document Server

    Catanesi, M G; Edgecock, R; Ellis, M; Robbins, S; Soler, F J P; Gössling, C; Bunyatov, S; Krasnoperov, A; Popov, B; Serdiouk, V; Tereschenko, V; Di Capua, E; Vidal-Sitjes, G; Artamonov, A; Arce, P; Giani, S; Gilardoni, S; Gorbunov, P; Grant, A; Grossheim, A; Gruber, P; Ivanchenko, V; Kayis-Topaksu, A; Panman, J; Papadopoulos, I; Pasternak, J; Chernyaev, E; Tsukerman, I; Veenhof, R; Wiebusch, C; Zucchelli, P; Blondel, A; Borghi, S; Campanelli, M; Morone, M C; Prior, G; Schroeter, R; Engel, R; Meurer, C; Kato, I; Gastaldi, Ugo; Mills, G B; Graulich, J S; Grégoire, G; Bonesini, M; Ferri, F; Paganoni, M; Paleari, F; Kirsanov, M; Bagulya, A; Grichine, V; Polukhina, N; Palladino, V; Coney, L; Schmitz, D; Barr, G; De Santo, A; Pattison, C; Zuber, K; Bobisut, F; Gibin, D; Guglielmi, A; Mezzetto, M; Dumarchez, J; Vannucci, F; Dore, U; Orestano, D; Pastore, F; Tonazzo, A; Tortora, L; Booth, C; Buttar, C; Hodgson, P; Howlett, L; Bogomilov, M; Chizhov, M; Kolev, D; Tsenov, R; Piperov, S; Temnikov, P; Apollonio, M; Chimenti, P; Giannini, G; Santin, G; Burguet-Castell, J; Cervera-Villanueva, A; Gómez-Cadenas, J J; Martín-Albo, J; Novella, P; Sorel, M; Tornero, A

    2008-01-01

    A measurement of the double-differential $\\pi^{\\pm}$ production cross-section in proton--carbon, proton--copper and proton--tin collisions in the range of pion momentum $100 \\MeVc \\leq p < 800 \\MeVc$ and angle $0.35 \\rad \\le \\theta <2.15 \\rad$ is presented. The data were taken with the HARP detector in the T9 beam line of the CERN PS. The pions were produced by proton beams in a momentum range from 3 \\GeVc to 12 \\GeVc hitting a target with a thickness of 5% of a nuclear interaction length. The tracking and identification of the produced particles was done using a small-radius cylindrical time projection chamber (TPC) placed in a solenoidal magnet. An elaborate system of detectors in the beam line ensured the identification of the incident particles. Results are shown for the double-differential cross-sections at four incident proton beam momenta (3 \\GeVc, 5 \\GeVc, 8 \\GeVc and 12 \\GeVc).

  10. Large-angle production of charged pions by 3 GeV/c-12 GeV/c protons on carbon, copper and tin targets

    Science.gov (United States)

    Catanesi, M. G.; Radicioni, E.; Edgecock, R.; Ellis, M.; Robbins, S.; Soler, F. J. P.; Gößling, C.; Bunyatov, S.; Krasnoperov, A.; Popov, B.; Serdiouk, V.; Tereschenko, V.; di Capua, E.; Vidal-Sitjes, G.; Arce, P.; Artamonov, A.; Giani, S.; Gilardoni, S.; Gorbunov, P.; Grant, A.; Grossheim, A.; Gruber, P.; Ivanchenko, V.; Kayis-Topaksu, A.; Panman, J.; Papadopoulos, I.; Pasternak, J.; Tcherniaev, E.; Tsukerman, I.; Veenhof, R.; Wiebusch, C.; Zucchelli, P.; Blondel, A.; Borghi, S.; Campanelli, M.; Morone, M. C.; Prior, G.; Schroeter, R.; Engel, R.; Meurer, C.; Kato, I.; Gastaldi, U.; Mills, G. B.; Graulich, J. S.; Grégoire, G.; Kirsanov, M.; Bonesini, M.; Ferri, F.; Paganoni, M.; Paleari, F.; Bagulya, A.; Grichine, V.; Polukhina, N.; Palladino, V.; Coney, L.; Schmitz, D.; Barr, G.; de Santo, A.; Pattison, C.; Zuber, K.; Bobisut, F.; Gibin, D.; Guglielmi, A.; Mezzetto, M.; Dumarchez, J.; Vannucci, F.; Dore, U.; Orestano, D.; Pastore, F.; Tonazzo, A.; Tortora, L.; Booth, C.; Buttar, C.; Hodgson, P.; Howlett, L.; Bogomilov, M.; Chizhov, M.; Kolev, D.; Tsenov, R.; Piperov, S.; Temnikov, P.; Apollonio, M.; Chimenti, P.; Giannini, G.; Santin, G.; Burguet-Castell, J.; Cervera-Villanueva, A.; Gómez-Cadenas, J. J.; Martín-Albo, J.; Novella, P.; Sorel, M.; Tornero, A.

    2008-01-01

    A measurement of the double-differential π± production cross-section in proton-carbon, proton-copper and proton-tin collisions in the range of pion momentum 100 MeV/ c≤p<800 MeV/ c and angle 0.35 rad≤θ<2.15 rad is presented. The data were taken with the HARP detector in the T9 beam line of the CERN PS. The pions were produced by proton beams in a momentum range from 3 GeV/ c to 12 GeV/ c hitting a target with a thickness of 5% of a nuclear interaction length. The tracking and identification of the produced particles was done using a small-radius cylindrical time projection chamber (TPC) placed in a solenoidal magnet. An elaborate system of detectors in the beam line ensured the identification of the incident particles. Results are shown for the double-differential cross-sections d2σ/dpdθ at four incident proton beam momenta (3 GeV/ c, 5 GeV/ c, 8 GeV/ c and 12 GeV/ c).

  11. Detectability and significance of 12 hr barometric tide in radon-222 signal, drip water flow rate, air temperature and carbon dioxide concentration in an underground tunnel

    International Nuclear Information System (INIS)

    Searching for small periodic signals, such as the 12 hr (S2) barometric tide, and monitoring their amplitude as a function of time, can provide important clues on the complex processes affecting fluid transport in unsaturated fractured media under multiple influences. Here, first, we show that a modified spectrogram analysis (MSA) is more efficient than simple Fourier transform to reveal weak periodic signals. Secondly, we show how transient periodic signals can be monitored as a function of time using spectrograms. These methods are applied to time-series of radon and carbon dioxide concentration, drip water flow rates and air temperature measured during several years in the Roselend dead-end tunnel, located in the French Alps near an artificial lake. A weak S2 line is evidenced in radon concentration, with enhanced amplitude during transient radon bursts. Similarly, the S2 line is observed using MSA in drip water flow rates which sample mainly fracture flow, as suggested by a hydrochemical analysis, while it is not seen in drip water flow rates sampling matrix flow. In the absence of a strong 24 hr line, the presence of a S2 line suggests sensitivity to barometric pressure, and thus a significant advective contribution in radon and some drip water transport. No S2 line is observed in the carbon dioxide time-series. The temporal structure of the S2 component, however, is not similar in the radon concentration and the drip water flow rates, suggesting, in particular, that drip water does not play a significant role in the generation of radon bursts. Temperature time-series exhibit a significant S2 contribution, induced by atmospheric pressure, spatially organised in the tunnel, decreasing vertically upwards. A remarkable transient temperature inversion during radon bursts suggests that the additional advective air contributions responsible for the radon bursts occur from the non-saturated rocks below the tunnel. (authors)

  12. Detectability and significance of 12 hr barometric tide in radon-222 signal, drip water flow rate, air temperature and carbon dioxide concentration in an underground tunnel

    Energy Technology Data Exchange (ETDEWEB)

    Richon, P.; Pili, E. [CEA Bruyeres le Chatel, Dept Analyse Surveillance Environm, 91 (France); Richon, P. [Inst Phys Globe, Equipe Geol Syst Volcan, UMR 7154, F-75252 Paris 05 (France); Perrier, F. [Univ Paris Diderot, Equipe Geomagnetisme, UMR 7154, Inst Phys Globe, F-75252 Paris 05 (France); Sabroux, J. Ch. [CEA Saclay, Inst Radioprotect and Surete Nucl, 91 - Gif-sur-Yvette (France)

    2009-03-15

    Searching for small periodic signals, such as the 12 hr (S{sub 2}) barometric tide, and monitoring their amplitude as a function of time, can provide important clues on the complex processes affecting fluid transport in unsaturated fractured media under multiple influences. Here, first, we show that a modified spectrogram analysis (MSA) is more efficient than simple Fourier transform to reveal weak periodic signals. Secondly, we show how transient periodic signals can be monitored as a function of time using spectrograms. These methods are applied to time-series of radon and carbon dioxide concentration, drip water flow rates and air temperature measured during several years in the Roselend dead-end tunnel, located in the French Alps near an artificial lake. A weak S{sub 2} line is evidenced in radon concentration, with enhanced amplitude during transient radon bursts. Similarly, the S{sub 2} line is observed using MSA in drip water flow rates which sample mainly fracture flow, as suggested by a hydrochemical analysis, while it is not seen in drip water flow rates sampling matrix flow. In the absence of a strong 24 hr line, the presence of a S{sub 2} line suggests sensitivity to barometric pressure, and thus a significant advective contribution in radon and some drip water transport. No S{sub 2} line is observed in the carbon dioxide time-series. The temporal structure of the S{sub 2} component, however, is not similar in the radon concentration and the drip water flow rates, suggesting, in particular, that drip water does not play a significant role in the generation of radon bursts. Temperature time-series exhibit a significant S{sub 2} contribution, induced by atmospheric pressure, spatially organised in the tunnel, decreasing vertically upwards. A remarkable transient temperature inversion during radon bursts suggests that the additional advective air contributions responsible for the radon bursts occur from the non-saturated rocks below the tunnel. (authors)

  13. Oxygen reduction in acid media: influence of the activity of CoNPc(1,2) bilayer deposits in relation to their attachment to the carbon black support and role of surface groups as a function of heat treatment

    NARCIS (Netherlands)

    Biloul, A.; Contamin, O.; Scarbeck, G.; Savy, M.; Palys, B.J.; Riga, J.; Verbist, J.

    1994-01-01

    O2 reduction was investigated using rotating disk electrode and voltammetry techniques on NPcCo(1,2) impregnations deposited onto two kinds of carbon black support. They were selected on the basis of their similar pH and dibuthylphthalate (DBP) adsorption values. Samples were also characterized by I

  14. Traceability of animal byproducts in quail (Coturnix coturnix japonica tissues using carbon (13C/12C and nitrogen (15N/14N stable isotopes

    Directory of Open Access Journals (Sweden)

    C Móri

    2007-12-01

    Full Text Available Consistent information on meat products consumed by the public is essential. The technique of stable isotopes is a powerful tool to recover consumers' confidence, as it allows the detection of animal byproduct residues in poultry meat, particularly in quail meat. This study aimed at checking the presence of poultry byproduct mixtures in quail diets by applying the technique of carbon (13C/12C and nitrogen (15N/14N stable isotopes in quail breast muscle, keel, and tibia. Sixty four one-day-old male quails were obtained from a commercial farm. Birds were housed in an experimental house from one to 42 days of age, and were randomly distributed into 8 experimental treatments, and fed diets containing poultry offal meal (POM, bovine meat and bone meal (MBM or poultry feather meal (PFM, or their mixtures. Four birds per treatment were slaughtered at 42 days of age, and breast (Pectoralis major, keel, and tibia were collected for analyses. The inclusion of animal byproducts in quail diets was detected by 13C e 15N analyses in the tissues of the birds; however, it was not possible to specify which byproducts were used. It was concluded that quail meat can be certified by the technique of stable isotopes.

  15. Carbon-rich presolar grains from massive stars. Subsolar 12C/13C and 14N/15N ratios and the mystery of 15N

    CERN Document Server

    Pignatari, M; Hoppe, P; Jordan, C J; Gibson, B K; Trappitsch, R; Herwig, F; Fryer, C; Hirschi, R; Timmes, F X

    2015-01-01

    Carbon-rich grains with isotopic anomalies compared to the Sun are found in primitive meteorites. They were made by stars, and carry the original stellar nucleosynthesis signature. Silicon carbide grains of Type X and C, and low-density graphites condensed in the ejecta of core-collapse supernovae. We present a new set of models for the explosive He shell and compare them with the grains showing 12C/13C and 14N/15N ratios lower than solar. In the stellar progenitor H was ingested into the He shell and not fully destroyed before the explosion. Different explosion energies and H concentrations are considered. If the SN shock hits the He-shell region with some H still present, the models can reproduce the C and N isotopic signatures in C-rich grains. Hot-CNO cycle isotopic signatures are obtained, including a large production of 13C and 15N. The short-lived radionuclides 22Na and 26Al are increased by orders of magnitude. The production of radiogenic 22Ne from the decay of 22Na in the He shell might solve the pu...

  16. Solvation structure and dynamics of cis- and trans-1,2 dichloroethene isomers in supercritical carbon dioxide. A molecular dynamics simulation study.

    Science.gov (United States)

    Dellis, Dimitris; Skarmoutsos, Ioannis; Samios, Jannis

    2011-10-27

    Molecular dynamics simulation techniques have been employed to investigate the solvation structure and dynamics in dilute mixtures of cis- and trans-1,2-dichloroethene in supercritical carbon dioxide. The calculations were performed for state points along a near-critical isotherm (1.02 T(c)) over a wide range of densities, using new developed optimized potential models for both isomers. The similarities and differences in the solvation structures around each isomer have been presented and discussed. The local density augmentation and enhancement factors of CO(2) around the isomers have been found significantly larger than the corresponding values for pure supercritical CO(2). The dynamic local density reorganization has been investigated and related to previously proposed relaxation mechanisms. The density dependence of the calculated self-diffusion coefficients has revealed the existence of a plateau in the region of 0.7-1.1 ρ(c), where the local density augmentation exhibits the maximum value. The reorientational dynamics of the C═C bond vector have been also studied, exhibiting significant differences between the two isomers in the case of the second-order Legendre time correlation functions.

  17. Evaluation of NorESM-OC (versions 1 and 1.2), the ocean carbon-cycle stand-alone configuration of the Norwegian Earth System Model (NorESM1)

    Science.gov (United States)

    Schwinger, Jörg; Goris, Nadine; Tjiputra, Jerry F.; Kriest, Iris; Bentsen, Mats; Bethke, Ingo; Ilicak, Mehmet; Assmann, Karen M.; Heinze, Christoph

    2016-08-01

    Idealised and hindcast simulations performed with the stand-alone ocean carbon-cycle configuration of the Norwegian Earth System Model (NorESM-OC) are described and evaluated. We present simulation results of three different model configurations (two different model versions at different grid resolutions) using two different atmospheric forcing data sets. Model version NorESM-OC1 corresponds to the version that is included in the NorESM-ME1 fully coupled model, which participated in CMIP5. The main update between NorESM-OC1 and NorESM-OC1.2 is the addition of two new options for the treatment of sinking particles. We find that using a constant sinking speed, which has been the standard in NorESM's ocean carbon cycle module HAMOCC (HAMburg Ocean Carbon Cycle model), does not transport enough particulate organic carbon (POC) into the deep ocean below approximately 2000 m depth. The two newly implemented parameterisations, a particle aggregation scheme with prognostic sinking speed, and a simpler scheme that uses a linear increase in the sinking speed with depth, provide better agreement with observed POC fluxes. Additionally, reduced deep ocean biases of oxygen and remineralised phosphate indicate a better performance of the new parameterisations. For model version 1.2, a re-tuning of the ecosystem parameterisation has been performed, which (i) reduces previously too high primary production at high latitudes, (ii) consequently improves model results for surface nutrients, and (iii) reduces alkalinity and dissolved inorganic carbon biases at low latitudes. We use hindcast simulations with prescribed observed and constant (pre-industrial) atmospheric CO2 concentrations to derive the past and contemporary ocean carbon sink. For the period 1990-1999 we find an average ocean carbon uptake ranging from 2.01 to 2.58 Pg C yr-1 depending on model version, grid resolution, and atmospheric forcing data set.

  18. Melting relations of multicomponent carbonate MgCO3-FeCO3-CaCO3-Na2CO3 system at 12-26 GPa: application to deeper mantle diamond formation

    Science.gov (United States)

    Spivak, Anna; Solopova, Natalia; Dubrovinsky, Leonid; Litvin, Yuriy

    2015-11-01

    Carbonatic components of parental melts of the deeper mantle diamonds are inferred from their primary inclusions of (Mg, Fe, Ca, Na)-carbonate minerals trapped at PT conditions of the Earth's transition zone and lower mantle. PT phase diagrams of MgCO3-FeCO3-CaCO3-Na2CO3 system and its ternary MgCO3-FeCO3-Na2CO3 boundary join were studied at pressures between 12 and 24 GPa and high temperatures. Experimental data point to eutectic solidus phase relations and indicate liquidus boundaries for completely miscible (Mg, Fe, Ca, Na)- and (Mg, Fe, Ca)-carbonate melts. PT fields for partial carbonate melts associated with (Mg, Fe)-, (Ca, Fe, Na)-, and (Na2Ca, Na2Fe)-carbonate solid solution phases are determined. Effective nucleation and mass crystallization of deeper mantle diamonds are realized in multicomponent (Mg, Fe, Ca, Na)-carbonatite-carbon melts at 18 and 26 GPa. The multicomponent carbonate systems were melted at temperatures that are lower than the geothermal ones. This gives an evidence for generation of diamond-parental carbonatite melts and formation of diamonds at the PT conditions of transition zone and lower mantle.

  19. Dissolved inorganic carbon, pH and other variables measured from laboratory experiment studies from an experimental carbonate exposure system from 2013-12-09 to 2014-01-31 (NODC Accession 0123317)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains the carbon chemistry measurements of a laboratory experiment study to understand the effects of ocean acidification on winter...

  20. Dissolved inorganic carbon, pH and other variables measured from laboratory experiment studies from an experimental carbonate exposure system from 2013-05-15 to 2013-07-12 (NODC Accession 0123316)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains the carbon chemistry measurements of a laboratory experiment study to understand the effects of ocean acidification on winter...

  1. Bio-Carbon Accounting for Bio-Oil Co-Processing: 14C and 13C/12C

    Energy Technology Data Exchange (ETDEWEB)

    Mora, Claudia I. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Li, Zhenghua [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vance, Zachary [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-21

    This is a powerpoint presentation on bio-carbon accounting for bio-oil co-processing. Because of the overlapping range in the stable C isotope compositions of fossil oils and biooils from C3-type feedstocks, it is widely thought that stable isotopes are not useful to track renewable carbon during co-production. In contrast, our study demonstrates the utility of stable isotopes to: • capture a record of renewable carbon allocation between FCC products of co-processing • record changes in carbon apportionments due to changes in reactor or feed temperature Stable isotope trends as a function of percent bio-oil in the feed are more pronounced when the δ13C of the bio-oil endmember differs greatly from the VGO (i.e., it has a C4 biomass source–corn stover, switch grass, Miscanthus, sugarcane– versus a C3 biomass source– pine, wheat, rice, potato), but trends on the latter case are significant for endmember differences of just a few permil. The correlation between measured 14C and δ13C may be useful as an alternative to carbon accounting, but the relationship must first be established for different bio-oil sources.

  2. A facile strategy to prepare nano-crystalline Li4Ti5O12/C anode material via polyvinyl alcohol as carbon source for high-rate rechargeable Li-ion batteries

    International Nuclear Information System (INIS)

    Highlights: ► LTO/C nano-composites with 20–50 nm in size. ► LTO/C prepared using a sol–gel method via a simple carbon coating process. ► LTO/C exhibit a high-rate performance of 141 mA h g−1 and 83 mA h g−1 at 10 C and 80 C. - Abstract: Li4Ti5O12/C nano-particles is synthesized at 800 °C, and investigated by XRD, SEM, TEM and HRTEM, and the carbon in the composite is detected by Raman spectroscopy. Experimental results indicate that compared with those synthesized at 600, 700 and 900 °C and pure Li4Ti5O12 the Li4Ti5O12/C nanoparticles synthesized at 800 °C remarkably enhances the rate performance and cycling performance of lithium-ion batteries. Lithium-ion batteries with nanocrystalline Li4Ti5O12 used as anode exhibit an excellent reversible capacity of 169, 141, 132, 106 and 82 mA h g−1, at the current density of 1 C, 10 C, 20 C, 40 C and 80 C, respectively

  3. Carbon dioxide, temperature, salinity and other variables collected via time series monitoring from MOORINGS in the Gulf of Mexico from 2009-05-12 to 2009-12-21 (NODC Accession 0100068)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0100068 includes chemical, physical, time series and underway - surface data collected from MOORINGS in the Gulf of Mexico from 2009-05-12 to...

  4. Determination of vitamin B12 at multi-wall carbon nanotubes film modified gold electrode%多壁碳纳米管修饰金电极测定维生素B12

    Institute of Scientific and Technical Information of China (English)

    向伟; 李将渊; 马曾燕

    2007-01-01

    抗贫血药物维生素B12(VB12)俗称(氰)钴胺素,维生素B12是DNA合成的必需物质,若体内缺乏它,就会引起巨幼细胞贫血,高同型半胱氨酸血症和神经系统损害。因此,检测维生素B12可为血液系统和神经系统一些疾病的诊治提供依据,建立快捷简便的检测方法,在药物分析和医学检验中有应用价值。

  5. 高压氧舱抢救一氧化碳中毒12例临床分析%Hyperbaric oxygen chamber therapy in emergency treatment of carbon monoxide poisoning - Clinical analysis of 12 cases

    Institute of Scientific and Technical Information of China (English)

    董玉民; 赵玉红

    2001-01-01

    @@ 我院自1999年12月引进高压氧舱以来,至2000年3月共收治CO中毒病人12例,在应用药物治疗的同时,利用高压氧舱抢救CO中毒的患者中,取得了良好的疗效,现报告如下.

  6. 40 CFR 600.113-12 - Fuel economy and carbon-related exhaust emission calculations for FTP, HFET, US06, SC03 and cold...

    Science.gov (United States)

    2010-07-01

    ...)(A) Carbon weight fraction using the following equation: CWF = CWFg × MFg + 0.521 × MFe Where: CWFg... = Mass fraction gasoline = (G × SGg)/(G × SGg + E × SGm) MFe = Mass fraction ethanol = (E × SGm)/(G ×...

  7. FINAL REPORT: A Study of the Abundance and 13C/12C Ratio of Atmospheric Carbon Dioxide to Advance the Scientific Understanding of Terrestrial Processes Regulating the GCC

    Energy Technology Data Exchange (ETDEWEB)

    Keeling, R. F.; Piper, S. C.

    2008-12-23

    The main objective of this project was to continue research to develop carbon cycle relationships related to the land biosphere based on remote measurements of atmospheric CO2 concentration and its isotopic composition. The project continued time-series observations of atmospheric carbon dioxide and isotopic composition begun by Charles D. Keeling at remote sites, including Mauna Loa, the South Pole, and eight other sites. The program also included the development of methods for measuring radiocarbon content in the collected CO2 samples and carrying out radiocarbon measurements in collaboration with Tom Guilderson of Lawrence Berkeley National Laboratory (LLNL). The radiocarbon measurements can provide complementary information on carbon exchange rates with the land and oceans and emissions from fossil-fuel burning. Using models of varying complexity, the concentration and isotopic measurements were used to establish estimates of the spatial and temporal variations in the net CO2 exchange with the atmosphere, the storage of carbon in the land and oceans, and variable isotopic discrimination of land plants.

  8. Pioneer 12 (PN-12)

    Science.gov (United States)

    Lozier, D.; Fimmel, R.

    1991-01-01

    The DSN (Deep Space Network) mission support requirements for Pioneer 12 are summarized. The Pioneer 12 spacecraft is in a 24-hour elliptical orbit around Venus. Atmospheric and altimetry data are obtained mainly around periapsis, and planetary imaging is normally performed around apoapsis. The Pioneer 12 mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; support parameters for telemetry, command and support systems; and tracking support responsibility.

  9. Effect of unburned carbon content in fly ash on the retention of 12 elements out of coal-combustion flue gas

    Institute of Scientific and Technical Information of China (English)

    Lucie Barto(n)ová; Bohumír (C)ech; Lucie Ruppenthalová; Vendula Majvelderová; Dagmar Juchelková; Zdeněk Klika

    2012-01-01

    The aim of this study was to evaluate whether unburned carbon particles present in fly ash can help in the retention of S,CI,Br,As,Se,Cu,Ni,Zn,Ga,Ge,Rb,and Pb out of flue gas during the coal combustion at fluidised-bed power station where the coal was combusted along with limestone.The competitive influence of 10%-25% CaO in fly ashes on the distribution of studied elements was studied as well to be clear which factor governs behaviour of studied elements.Except of S (with significant association with CaO) and Rb and Pb (with major affinity to Al2O3) the statistically significant and positive correlation coefficients were calculated for the relations between unburned carbon content and Br (0.959),Cl (0.957),Cu (0.916),Se (0.898),Ni (0.866),As (0.861),Zn (0.742),Ge (0.717),and Ga (0.588) content.The results suggest that the unburned carbon is promising material in terms of flue gas cleaning even if contained in highly calcareous fly ashes.

  10. Volumetric Properties of the Mixture Dimethyl carbonate C3H6O3 + C6H12O3 2,4,6-Trimethyl-1,3,5-trioxane (VMSD1511, LB4517_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Dimethyl carbonate C3H6O3 + C6H12O3 2,4,6-Trimethyl-1,3,5-trioxane (VMSD1511, LB4517_V)' providing data from direct measurement of low-pressure thermodynamic speed of sound at variable mole fraction and constant temperature, in the single-phase region(s).

  11. Volumetric Properties of the Mixture Dimethyl carbonate C3H6O3 + C6H12O3 2,4,6-Trimethyl-1,3,5-trioxane (VMSD1212, LB4519_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Dimethyl carbonate C3H6O3 + C6H12O3 2,4,6-Trimethyl-1,3,5-trioxane (VMSD1212, LB4519_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  12. Volumetric Properties of the Mixture Dimethyl carbonate C3H6O3 + C6H12O3 2,4,6-Trimethyl-1,3,5-trioxane (VMSD1111, LB4518_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Dimethyl carbonate C3H6O3 + C6H12O3 2,4,6-Trimethyl-1,3,5-trioxane (VMSD1111, LB4518_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  13. Isotopic signatures (13C/12C; 15N/14N) of blue penguin burrow soil invertebrates : carbon sources and trophic relationships

    International Nuclear Information System (INIS)

    Seabird burrows provide a soil environment for processing discards such as feathers and guano, hence constituting a primary interface between the sea and the land. This study involved collection and culturing of soil invertebrates from three blue penguin (Eudyptula minor) burrows, and examined their 13C/12C and 15N/14N isotopic composition in relation to potential burrow resources (terrestrial plant litter, burrow soil, guano, blue penguin feathers). Two taxa (cerylonid beetles and small tineid moth larvae) had a depleted 13C/12C indicative of a level of dependence on C from terrestrial soil. Tineid moth larvae (Monopis crocicapitella and (or) M. ethelella) substantially increased their 13C/12C enrichment during development, implying increasing dependence on marine C. Remaining taxa, both decomposers and predators, had 13C/12C intermediate between guano and feathers. Larval and emergent fleas had the most enriched 13C/12C , indicative of a greater dependence on feather C and the likelihood of co-processing with guano. Pseudoscorpions and histerid beetles had overlapping isotopic enrichments implying competition for prey, but were spatially separated in burrow soil. With their highly enriched 15N/14N and marine 13C/12C, larvae and protonymphs of the histiostomatid mite Myianoetus antipodus stood alone. Blue penguin burrows therefore support a diverse invertebrate fauna that incorporates terrestrial soil as well as varying proportions of the various blue penguin discards. (author). 45 refs., 1 fig., 1 tab.

  14. Preparation and selective laser sintering behavior of carbon fiber/polyamide 1 2 composite%炭纤维/尼龙12复合粉体的制备及选择性激光烧结行为

    Institute of Scientific and Technical Information of China (English)

    吴琼; 陈惠; 巫静; 夏笑虹; 许小曙; 边宏; 刘洪波

    2016-01-01

    采用液相氧化法对PAN基短切炭纤维进行表面改性,再与尼龙12混合,采用选择性激光烧结成形技术制备炭纤维/尼龙12复合粉体试样。利用扫描电子显微镜(SEM)、傅里叶变换红外光谱(FT-IR)表征炭纤维改性前后的表面状态、复合粉体的分散状况及烧结试样的断口形貌。探讨了复合粉体的烧结行为及烧结试样的力学性能与孔隙率的关系。结果表明,改性炭纤维表面的含氧基团在激光烧结时热分解产生气体,导致烧结试样孔隙率较高、力学性能较差。改性炭纤维经高温热处理可以在保留炭纤维表面粗糙度的同时有效降低烧结试样的孔隙率,与未改性炭纤维/尼龙12试样相比,拉伸强度、拉伸模量、弯曲强度和弯曲模量均有不同程度的提高。%The PAN-based chopped carbon fibers were surface modified by liquid-phase oxidation,mixed with polyamide 12,and the carbon fiber reinforced polyamide 12 composites were prepared by selective laser sinte-ring technology.Scanning electron microscope and Fourier transform infrared spectrum were applied to the characterization of the surface state on the carbon fibers before and after modification,the dispersity of compos-ite powder,and fracture morphology of the sintered components.The sintering behavior of composite powder, the relationship between mechanical property and porosity of the sintered components were also discussed.The results show that the oxygen-containing groups on the surface of modified carbon fibers are thermal decomposed and release gas in the process of laser sintering,which cause a high porosity and poor mechanical properties of the sintered components.While the carbon fibers treated under high temperature after modification can preserve the surface roughness,lower the porosity at the same time,and compared with the unmodified carbon fiber re-inforced polyamide 1 2 sintered components,the tensile strength,tensile modulus

  15. Carbon Residence Times in Pedogenic Carbonate Pools

    Science.gov (United States)

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

    2013-12-01

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

  16. Control of the environmental inluences on THe-Trap on the example of the determination of the mass ratio of carbon-12 to oxygen-16

    International Nuclear Information System (INIS)

    Tritium-Helium-3-Trap (THe-Trap) is a Penning-trap setup dedicated to measure the 3H to 3He mass ratio with a relative uncertainty of better than 10-11. This is 40 times more precise than the currently adopted value and, thus, will help to investigate possible systematic uncertainties of the Karlsruhe Tritium Neutrino experiment (KATRIN). To achieve the desired level of uncertainty, several environmental influences such as atmospheric pressure shifts and magnetic field fluctuations have to be suppressed. With the implemented stabilization system, the relative magnetic field drift could be reduced to a few 10-12/h for a time span of several weeks. Within the context of this thesis a mass ratio measurement of 12C4+ to 16O5+ was performed to characterize systematic effects. This measurement yielded a statistical uncertainty of 6.3 x 10-11, which can easily be improved with more statistics, i.e. a longer measurement time. While the systematic uncertainty for 12C4+-ions were under control at the 10-11 level, the systematic shifts could not be quantified for 16O5+ due to poor vacuum conditions. Without these corrections, a systematic uncertainty of 1.2.10-10 could be achieved for the 12C/16O mass ratio measurement.

  17. Mesoporous Li4Ti5O12 nanoclusters anchored on super-aligned carbon nanotubes as high performance electrodes for lithium ion batteries

    Science.gov (United States)

    Sun, Li; Kong, Weibang; Wu, Hengcai; Wu, Yang; Wang, Datao; Zhao, Fei; Jiang, Kaili; Li, Qunqing; Wang, Jiaping; Fan, Shoushan

    2015-12-01

    Mesoporous lithium titanate (LTO) nanoclusters are in situ synthesized in a network of super aligned carbon nanotubes (SACNTs) via a solution-based method followed by heat treatment in air. In the LTO-CNT composite, SACNTs not only serve as the skeleton to support a binder-free electrode, but also render the composite with high conductivity, flexibility, and mechanical strength. The homogeneously dispersed LTO nanoclusters among the SACNTs allow each LTO grain to effectively access the electrolyte and the conductive network, benefiting both ion and electron transport. By the incorporation of LTO into the CNT network, mechanical reinforcement is also achieved. When serving as a negative electrode for lithium ion batteries, such a robust composite-network architecture provides the electrodes with effective charge transport and structural integrity, leading to high-performance flexible electrodes with high capacity, high rate capability, and excellent cycling stability.Mesoporous lithium titanate (LTO) nanoclusters are in situ synthesized in a network of super aligned carbon nanotubes (SACNTs) via a solution-based method followed by heat treatment in air. In the LTO-CNT composite, SACNTs not only serve as the skeleton to support a binder-free electrode, but also render the composite with high conductivity, flexibility, and mechanical strength. The homogeneously dispersed LTO nanoclusters among the SACNTs allow each LTO grain to effectively access the electrolyte and the conductive network, benefiting both ion and electron transport. By the incorporation of LTO into the CNT network, mechanical reinforcement is also achieved. When serving as a negative electrode for lithium ion batteries, such a robust composite-network architecture provides the electrodes with effective charge transport and structural integrity, leading to high-performance flexible electrodes with high capacity, high rate capability, and excellent cycling stability. Electronic supplementary information

  18. Laboratory measurement of the 2-centimeter, 2/11/-2/12/ transition of normal formaldehyde and its carbon-13 and oxygen-18 species.

    Science.gov (United States)

    Tucker, K. D.; Tomasevich, G. R.; Thaddeus, P.

    1972-01-01

    Beam-maser spectrometric measurements to an accuracy of about 100 Hz have been conducted of the 2(11)-2(12) transition for the isotopic species of greatest astronomical interest - i.e., H2CO, H2(13)CO, and H2C(18)O. The samples used were not isotopically enriched, monomeric formaldehyde vapors. For these species, all the coupling constants required to calculate the hyperfine structure of any rotational transition have been determined.

  19. Self–activation and effect of regeneration conditions in CO2 – carbonate looping with CaO - Ca12Al14O33 sorbent

    OpenAIRE

    STENDARDO Stefano; Andersen, Lars; HERCE C

    2012-01-01

    CO2 capture by solid sorbents through uptake–regeneration cycling is a promising option for high temperature removal of CO2 from combustion gases and synthesis/fuel gases. The present study investigates the influence of regeneration atmosphere and temperature on the CO2 uptake capacity during repeated cycling of CaO–based solid sorbents. The sorbents were synthesised to contain 75 and 85 %w/w of active phase (CaO) and binder (Ca12Al14O33) and were then subjected to cycling tests with repeate...

  20. Studies of palaeovegetation changes in the Central Amazon by carbon isotopes (12C, 13C, 14C) of soil organic matter

    International Nuclear Information System (INIS)

    The paper presents carbon isotope data δ13C and 14C on soil organic matter collected along an ecosystem transect in southern Amazon state, north-central Amazon region, that includes three distinct vegetation communities: savannah (Campos de Humaita), a savannah-forest transition and forest (Manaus). The study sites are located along road BR 319. Botanical identification and 13C analysis of modern vegetation in the savannah and forest sites indicate that most of the vegetation is C3 plants, although a few C4 plants are present at Campos de Humaita. The 13C and 14C data for soil organic matter in the Humaita region show that significant vegetation changes have occurred in the past, probably associated with climatic changes. During the early Holocene, forest vegetation extended throughout the study region, including areas occupied today by savannah vegetation. Savannah vegetation expanded at least 2 km into the modern forest ecotone during the middle Holocene, suggesting drier conditions. The last approximately 1000 years appear to indicate a recent expansion of forest vegetation, reflecting a return to a more moist climate. The study illustrates that the transition area between forest and savannah vegetation is quite sensitive to climatic changes, and this region should be the focus of more extensive research related to past climate and vegetation dynamics in the Amazon region. (author)

  1. Carbon Dioxide, Hydrographic, and Chemical Data Obtained During the R/V Meteor Cruise 28/1 in the South Atlantic Ocean (WOCE Section A8, March 29 - May 12, 1994)

    Energy Technology Data Exchange (ETDEWEB)

    Kozyr, A.

    2002-05-09

    This data documentation discusses the procedures and methods used to measure total carbon dioxide (TCO{sub 2}) and the fugacity of CO{sub 2} (fCO{sub 2}) at hydrographic stations during the R/V Meteor oceanographic cruise 28/1 in the South Atlantic Ocean (Section A8). Conducted as part of the World Ocean Circulation Experiment (WOCE), the cruise began in Recife, Brazil, on March 29, 1994, and ended after 35 days at sea in Walvis Bay, Namibia, on May 12, 1994. Instructions for accessing the data are provided. TCO{sub 2} was measured using two single-operator multiparameter metabolic analyzers (SOMMA) coupled to a coulometer for extracting and detecting CO{sub 2} from seawater samples. The overall precision and accuracy of the analyses was {+-}1.17 {micro}mol/kg. For the second carbonate system parameter, the fCO{sub 2} was measured in discrete samples by equilibrating a known volume of liquid phase (seawater) with a known volume of a gas phase containing a known mixture of CO{sub 2} in gaseous nitrogen (N{sub 2}). After equilibration, the gas phase CO{sub 2} concentration was determined by flame ionization detection following the catalytic conversion of CO{sub 2} to methane (CH{sub 4}). The precision of these measurements was less than or equal to 1.0%. The R/V Meteor Cruise 28/1 data set is available free of charge as a numeric data package (NDP) from the Carbon Dioxide Information Analysis Center. The NDP consists of two oceanographic data files, two FORTRAN 90 data retrieval routine files, a readme file, and this printed documentation that describes the contents and format of all files as well as the procedures and methods used to obtain the data.

  2. Neutron Dose measurement in the carbon ion therapy area at HIRFL (IMP) as 12C ions with energies from 165 to 350MeV/u

    CERN Document Server

    Xu, Jun-Kui; Yan, Wei-Wei; Su, You-Wu; Li, Zong-Qiang; Wang, Mao; Pang, Cheng-Guo; Xu, Chong

    2016-01-01

    The neutron dose distributions on observation distances and on observation angles were measured using a Wendi-II neutron dose-meter at the deep tumor therapy terminal at HIRFL (Heavy Ion Research Facility in Lanzhou) as 12C ions with energies from 165 to 350 MeV/u bombarding on thick solid water targets with different thickness according to the ion energies. The experimental results were compared with those calculated by FLUKA code. It is found that the experimental data was in good agreement with the calculated results. The neutron energy spectra were also studied by using the FLUKA code. The results are valuable for the shielding design of high energy heavy ion medical machines and for the individual dose assessment.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-07-01

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

  4. Preparation and analysis of amorphous carbon films deposited from (C{sub 6}H{sub 12})/Ar/He chemistry for application as the dry etch hard mask in the semiconductor manufacturing process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seungmoo [Department of Materials Science and Engineering, Korea University, Seoul, 136-701 (Korea, Republic of); TC Technology Team, Samsung Electronics Co. Ltd., Gyeounggi-Do, 446-711 (Korea, Republic of); Won, Jaihyung; Choi, Jongsik [TC Technology Team, Samsung Electronics Co. Ltd., Gyeounggi-Do, 446-711 (Korea, Republic of); Jang, Samseok [Department of Materials Science and Engineering, Korea University, Seoul, 136-701 (Korea, Republic of); Jee, Yeonhong; Lee, Hyeondeok [TC Technology Team, Samsung Electronics Co. Ltd., Gyeounggi-Do, 446-711 (Korea, Republic of); Byun, Dongjin, E-mail: dbyun@korea.ac.kr [Department of Materials Science and Engineering, Korea University, Seoul, 136-701 (Korea, Republic of)

    2011-08-01

    Amorphous carbon layers (ACL) were deposited on Si (100) wafers by plasma enhanced chemical vapor deposition (PECVD) by using 1-hexene (C{sub 6}H{sub 12}) as a carbon source for dry etch hard mask of semiconductor devices manufacturing process. The deposition characteristics and film properties were investigated by means of ellipsometry, Raman spectroscopy, X-ray photo electron spectroscopy (XPS) and stress analysis. Hardness, Young's modulus, and surface roughness of ACL deposited at 550 deg. C were investigated by using nano-indentation and AFM. The deposition rate was decreased from 5050 A/min to 2160 A/min, and dry etch rate was decreased from 2090 A/min to 1770 A/min, and extinction coefficient was increased from 0.1 to 0.5. Raman analysis revealed a higher shift of the G-peak and a lower shift of the D-peak and the increase of I(D)/I(G) ratio as the deposition temperature was increased from 350 deg. C to 550 deg. C. XPS results of ACL deposited at 550 deg. C revealed a carbon 1s binding energy of 284.4 eV. The compressive film stress was decreased from 2.95 GPa to 1.28 GPa with increasing deposition temperature. The hardness and Young's modulus of ACL deposited at 550 deg. C were 5.8 GPa and 48.7 GPa respectively. The surface roughness RMS of ACL deposited at 550 deg. C was 2.24 A, and that after cleaning in diluted HF solution (H{sub 2}O:HF = 200:1), SC1 (NH{sub 4}OH:H{sub 2}O{sub 2}:H{sub 2}O = 1:4:20) solution, and sulfuric acid solution (H{sub 2}SO{sub 4}:H{sub 2}O{sub 2} = 6:1) was 2.28 A, 2.30 A and 7.34 A, respectively. The removal amount of ACL deposited at 550 deg. C in diluted HF solution, SC1 solution and sulfuric acid solution was 6 A, 36 A and 110 A, respectively. These results demonstrated the viability of ACL deposited by PECVD from C{sub 6}H{sub 12} at 550 deg. C for application as the dry etch hard mask in fabrication of semiconductor devices.

  5. Immobilization of [Cu(bpy){sub 2}]Br{sub 2} complex onto a glassy carbon electrode modified with {alpha}-SiMo{sub 12}O{sub 40}{sup 4-} and single walled carbon nanotubes: Application to nanomolar detection of hydrogen peroxide and bromate

    Energy Technology Data Exchange (ETDEWEB)

    Salimi, Abdollah [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Research Center for Nanotechnology, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of)], E-mail: absalimi@uok.ac.ir; Korani, Aazam; Hallaj, Rahman; Khoshnavazi, Roshan [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Hadadzadeh, Hasan [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2009-03-02

    A simple procedure has been used for preparation of modified glassy carbon electrode with carbon nanotubes and copper complex. Copper complex [Cu(bpy){sub 2}]Br{sub 2} was immobilized onto glassy carbon (GC) electrode modified with silicomolybdate, {alpha}-SiMo{sub 12}O{sub 40}{sup 4-} and single walled carbon nanotubes (SWCNTs){sub .} Copper complex and silicomolybdate irreversibly and strongly adsorbed onto GC electrode modified with CNTs. Electrostatic interactions between polyoxometalates (POMs) anions and Cu-complex, cations mentioned as an effective method for fabrication of three-dimensional structures. The modified electrode shows three reversible redox couples for polyoxometalate and one redox couple for Cu-complex at wide range of pH values. The electrochemical behavior, stability and electron transfer kinetics of the adsorbed redox couples were investigated using cyclic voltammetry. Due to electrostatic interaction, copper complex immobilized onto GC/CNTs/{alpha}-SiMo{sub 12}O{sub 40}{sup 4-} electrode shows more stable voltammetric response compared to GC/CNTs/Cu-complex modified electrode. In comparison to GC/CNTs/Cu-complex the GC/CNTs/{alpha}-SiMo{sub 12}O{sub 40}{sup 4-} modified electrodes shows excellent electrocatalytic activity toward reduction H{sub 2}O{sub 2} and BrO{sub 3}{sup -} at more reduced overpotential. The catalytic rate constants for catalytic reduction hydrogen peroxide and bromate were 4.5({+-}0.2) x 10{sup 3} M{sup -1} s{sup -1} and 3.0({+-}0.10) x 10{sup 3} M{sup -1} s{sup -1}, respectively. The hydrodynamic amperommetry technique at 0.08 V was used for detection of nanomolar concentration of hydrogen peroxide and bromate. Detection limit, sensitivity and linear concentration range proposed sensor for bromate and hydrogen peroxide detection were 1.1 nM and 6.7 nA nM{sup -1}, 10 nM-20 {mu}M, 1 nM, 5.5 nA nM{sup -1} and 10 nM-18 {mu}M, respectively.

  6. Carbon Carbon Composites: An Overview .

    OpenAIRE

    G. Rohini Devi; K. Rama Rao

    1993-01-01

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

  7. Electrochemical Behavior and Determination of Vitamin B12 at Multi-Wall Carbon Nanotubes Modified Glassy Carbon Electrode%维生素B12在多壁碳纳米管修饰玻碳电极上的电化学行为及其分析测定

    Institute of Scientific and Technical Information of China (English)

    向伟; 李将渊; 马曾燕

    2007-01-01

    制备了多壁碳纳米管修饰玻碳电极(MWNT/GCE),研究了该电极对维生素B12(VB12)的电催化作用并测定VB12的分析条件.结果表明,在以0.1 mol/L KCl为支持电解质,pH=7.0的磷酸缓冲溶液中,VB12在MWNT/GCE电极上出现2组氧化还原峰,式量电位分别为-0.10和-0.85 V.VB12在-0.85 V附近的还原峰电流的一次导数值与其浓度在1×10-8~4×10-7 mol/L范围内具有良好的线性关系,其关系式为i'p=5.958×10-7+2.885c(R=0.995),检出限为1.5×10-9 mol/L.以该电极对VB12样品进行测定,回收率为97.3%~107.8%.

  8. Carbon Carbon Composites: An Overview .

    Directory of Open Access Journals (Sweden)

    G. Rohini Devi

    1993-10-01

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

  9. 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

  10. Dissolved inorganic carbon, total alkalinity, pH, and other variables collected from surface and discrete observations using Niskin bottle, flow-through pump and other instruments from F.G. Walton Smith in the Gulf of Mexico (east coast of Florida near the Keys) from 2014-12-03 to 2014-12-04 (NCEI Accession 0154383)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Increasing amounts of atmospheric carbon dioxide from human industrial activities are causing changes in global ocean carbon chemistry. Through the SOOP program we...

  11. Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from MIRAI in the South Atlantic Ocean from 2003-11-06 to 2003-12-05 (NCEI Accession 0144246)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0144246 includes Surface underway data collected from MIRAI in the South Atlantic Ocean from 2003-11-06 to 2003-12-05. These data include AIR...

  12. Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from MIRAI in the Indian Ocean, Mozambique Channel and South Atlantic Ocean from 2003-12-09 to 2004-01-24 (NCEI Accession 0144250)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0144250 includes Surface underway data collected from MIRAI in the Indian Ocean, Mozambique Channel and South Atlantic Ocean from 2003-12-09 to...

  13. Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from time series observations using Bubble type equilibrator for autonomous carbon dioxide (CO2) measurement, Carbon dioxide (CO2) gas analyzer and other instruments from MOORINGS in the North Pacific Ocean from 2007-09-26 to 2010-12-24 (NODC Accession 0100071)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0100071 includes time series data collected from MOORINGS in the North Pacific Ocean from 2007-09-26 to 2010-12-24. These data include AIR-SEA...

  14. Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from time series observations using Bubble type equilibrator for autonomous carbon dioxide (CO2) measurement, Carbon dioxide (CO2) gas analyzer and other instruments from MOORINGS in the North Atlantic Ocean from 2010-12-05 to 2013-03-15 (NODC Accession 0117060)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0117060 includes time series data collected from MOORINGS in the North Atlantic Ocean from 2010-12-05 to 2013-03-15 and retrieved during cruise...

  15. Simultaneous Determination of Vitamin B2 ,B6, B12 and Vitamin C at Multi-Wall Carbon Nanotubes Modified Glassy Carbon Electrode%多壁碳纳米管修饰电极同时测定维生素B2、B6、B12和维生素C

    Institute of Scientific and Technical Information of China (English)

    向伟; 李将渊; 马曾燕

    2007-01-01

    制备了多壁碳纳米管修饰玻碳电极(MWNT/GCE),研究了维生素B2、B6、B12和维生素C共存时在该电极上的电化学行为.实验发现,在HAc-NaAc缓冲溶液中,该电极可同时测定以上四种维生素,线性范围分别为1.0×10-6~1.0×10-4 mol/L、5.0×10-5~2.0×10-3 mol/L、5.0×10-5~7.5×10-4 mol/L和5.0×10-5~2.0×10-3 mol/L,其检出限分别为7.0×10-7 mol/L、1.0×10-5 mol/L、2.5×10-5 mol/L和5.0×10-6 mol/L.样品分析的RSD分别为1.66%、1.71%、2.26%和1.46%.方法简便快捷,可用于四种维生素同时分析测定.

  16. Dissolved Inorganic Carbon, Alkalinity, pH, temperature, salinity, and other variables collected from profile observations using CTD, discrete bottles, and other instruments from February 12, 1985 to June 17, 2009, as synthesized in the Pacific Ocean Interior Carbon (PACIFICA) Database (NODC Accession 0110865)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — PACIFICA Data Synthesis Project PACIFICA (PACIFic ocean Interior CArbon) was an international collaborative project for the data synthesis of ocean interior carbon...

  17. 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.

  18. Dissolved inorganic carbon, total alkalinity, nitrate, phosphate, temperature and other variables collected from time series observations at Heron Island Reef Flat from 2010-06-01 to 2010-12-13 (NODC Accession 0127256)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains carbonate chemistry and environmental parameters data that were collected from a 200-day time series monitoring on the Heron Island...

  19. SPACEPART12

    CERN Multimedia

    Michele Famiglietti / widlab.com

    2012-01-01

    From 5 to 7 November, CERN will host the 4th International Conference on Particle and Fundamental Physics in Space (SpacePart12). Special talks open to the general public will be given by two of the biggest names in space exploration: Edward Stone, project scientist for the Voyager probes, and William Gerstenmaier, former Manager of the International Space Station (ISS) programme.

  20. Adsorption of Imidacloprid on Powdered Activated Carbon and Magnetic Activated Carbon

    OpenAIRE

    Zahoor, M.; Mahramanlioglu, M.

    2011-01-01

    The adsorptive characteristics of imidacloprid on magnetic activated carbon (MAC12) in comparison to powdered activated carbon (PAC) were investigated. Adsorption of imidacloprid onto powdered activated carbon and magnetic activated carbon was studied as a function of time, initial imidacloprid concentration, temperature and pH. Pseudo-first-order, pseudo-second-order and intraparticle diffusion models for both carbons were used to describe the kinetic data. The adsorption equilibrium data we...

  1. Highway 12

    OpenAIRE

    Probasco, Christian

    2005-01-01

    Highway 12 is undoubtedly one of not only America's but the world's most scenic highways. From its intersection on the west with Highway 89 south of Panguitch, Utah, it runs up through Red Canyon onto the Paunsagunt Plateau and across Bryce Canyon National Park. It then drops into the Paria River Valley, passes through several tiny villages, crosses some extraordinary (for anywhere but this region) badlands, and descends the Escalante River into Potato Valley. While a driver may justifiably f...

  2. Tendances Carbone n. 12 Mar. 2007; Tendances Carbone n. 12 mars 2007

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This newsletter presents first some lessons learnt from the European emissions trading system (market fluidity, administrative and political framework, careful but voluntaristic development of the system). Then it makes a synthesis of the European CO{sub 2} market over the last 13 months: traded volumes, spot prices, climate indexes (temperature, precipitations), economic activity indicators (industrial production index, business leaders' confidence index, changes in energy prices, CO{sub 2} quotas allocated to European Union countries, and detailed indicators of CO{sub 2} market, climate, economic activity and energy prices. (J.S.)

  3. Electrochemical Behavior of Vitamin B6 at Vitamin B12 Modified Glassy Carbon Electrode and Its Application%维生素B6在维生素B12修饰电极上的电化学行为及其分析应用

    Institute of Scientific and Technical Information of China (English)

    王燕; 毕春燕

    2012-01-01

    采用循环伏安法研究了维生素B6在维生素B12修饰玻碳电极上的电化学行为,建立了测定痕量维生素B6的新方法.在pH 8.6的NH3-NH4Cl缓冲溶液中,维生素B6在修饰电极上产生一个灵敏的氧化峰,采用差分脉冲伏安法测定,其氧化峰电流与维生素B6的浓度在8.0×10-7~2.0×10-4 mol/L范围内呈良好的线性关系,检出限为2.0×10-7 mol/L.该修饰电极具有良好的选择性、灵敏度及稳定性,用于片剂中维生素B6的定量分析,结果令人满意.%A Vitamin B,2 modified glassy carbon electrode was prepared. The electrochemical behavior of Vitamin B6 (VB6) was studied at the prepared electrode by cyclic voltammetry. The modified electrode showed an excellent electrocatalytical effect on oxidation of VB6. In NH3-NH4C1 buffer solution(pH 8.6), the anodic peak current had a linear relationship with VB6 concentration in the range of 8.0×10-7 -2.0×10-4 mol / L by differential pulse voltammetry. The detection limit was 2.0×10-7mol / L. The modified electrode had good selectivity and sensitivity. The proposed method had been applied to the determination of VB6 in tablets with satisfactory results.

  4. Critical elements in sediment-hosted deposits (clastic-dominated Zn-Pb-Ag, Mississippi Valley-type Zn-Pb, sedimentary rock-hosted Stratiform Cu, and carbonate-hosted Polymetallic Deposits): A review: Chapter 12

    Science.gov (United States)

    Marsh, Erin; Hitzman, Murray W.; Leach, David L.

    2016-01-01

    Some sediment-hosted base metal deposits, specifically the clastic-dominated (CD) Zn-Pb deposits, carbonate-hosted Mississippi Valley-type (MVT) deposits, sedimentary-rock hosted stratiform copper deposits, and carbonate-hosted polymetallic (“Kipushi type”) deposits, are or have been important sources of critical elements including Co, Ga, Ge, and Re. The generally poor data concerning trace element concentrations in these types of sediment-hosted ores suggest that there may be economically important concentrations of critical elements yet to be recognized.

  5. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the METEOR in the North Atlantic Ocean from 1994-10-12 to 1994-11-12 (NODC Accession 0113580)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113580 includes chemical, discrete sample, physical and profile data collected from METEOR in the North Atlantic Ocean from 1994-10-12 to 1994-11-12...

  6. Mean-field study of $^{12}$C+$^{12}$C fusion

    CERN Document Server

    Chien, Le Hoang; Khoa, Dao T

    2016-01-01

    The nuclear mean-field potential arising from the $^{12}$C+$^{12}$C interaction at the low energies relevant for the astrophysical carbon burning process has been constructed within the double-folding model, using the realistic nuclear ground-state density of the $^{12}$C nucleus and the effective M3Y nucleon-nucleon (NN) interaction constructed from the G-matrix of the Paris (free) NN potential. To explore the nuclear medium effect, both the original density independent M3Y-Paris interaction and its density dependent CDM3Y6 version have been used in the folding model calculation of the $^{12}$C+$^{12}$C potential. The folded potentials at the different energies were used in the optical model description of the elastic $^{12}$C+$^{12}$C scattering at the energies around and below the Coulomb barrier, as well as in the barrier penetration model to estimate the fusion cross section and astrophysical $S$ factor of the $^{12}$C+$^{12}$C reactions at the low energies. The obtained results are in good agreement wit...

  7. 45 CFR 12.12 - Utilization.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Utilization. 12.12 Section 12.12 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION DISPOSAL AND UTILIZATION OF SURPLUS REAL PROPERTY FOR PUBLIC HEALTH PURPOSES § 12.12 Utilization. (a) Where property or any portion thereof is...

  8. Soil carbon storage and N{sub 2}O emissions from wheat agroecosystems as affected by free-air CO{sub 2} enrichment (FACE) and nitrogen treatments. Final Report - February 12, 1999

    Energy Technology Data Exchange (ETDEWEB)

    S. W. Leavitt; A. D. Matthias; T. L. Thompson; R. A. Rauschkolb

    1999-02-17

    Rising atmospheric CO{sub 2} concentrations have prompted concern about response of plants and crops to future elevated CO{sub 2} levels, and particularly the extent to which ecosystems will sequester carbon and thus impact the rate of rise of CO{sub 2} concentrations. Free-air CO{sub 2} enrichment (FACE) experimentation was used with wheat agroecosystems for two growing seasons to assess effects of CO{sub 2} and soil nitrogen. Over 20 researchers on this experiment variously examined plant production and grain yield, phenology, length of growing season, water-use efficiency ecosystem production, below ground processes (eg, root and microbial activity, carbon and nitrogen cycling), etc.

  9. Dissolved inorganic carbon, total alkalinity, pH and other variables collected from surface discrete observations using infrared dissolved inorganic carbon analyzer, alkalinity titrator and other instruments from the North Atlantic Ocean near Key West, Florida (Class III climate monitoring sites) from 2012-03-23 to 2014-12-11 (NCEI Accession 0132022)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains data collected to monitor changes to coral reef carbonate chemistry over time, at US affiliated coral reef sites, through quantifying...

  10. 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.

  11. The structure of 12C

    Indian Academy of Sciences (India)

    Martin Freer

    2014-11-01

    The nucleus 12C has a rather significant role in modern nuclear physics, but whose influence can be traced to the work of Hoyle in the 1950s, when it was concluded that there should be a state close to 7.68 MeV responsible for the synthesis of carbon in stellar nucleosynthesis. Although a state at 7.65 MeV was subsequently discovered, its properties have remained something of a mystery until rather recently. This paper explores our current understanding of the structure of 12C, in particular the nature of the Hoyle state.

  12. Carbon and Carbon Isotope Cycling in the Western Canadian Arctic

    Science.gov (United States)

    Mol, Jacoba; Thomas, Helmuth

    2016-04-01

    Increasing carbon dioxide levels in the atmosphere are having drastic effects on the global oceans. The Arctic Ocean is particularly susceptible to change as warming, sea-ice loss and a weak buffering capacity all influence this complicated semi-enclosed sea. In order to investigate the inorganic carbon system in the Canadian Arctic, water samples were collected in the Beaufort Sea, on the Alaskan shelf, at the Mackenzie river delta, and in Amundsen Gulf during the summer of 2014 and were analyzed for dissolved inorganic carbon (DIC), total alkalinity (TA), DI13C and 18O isotopes. Carbon isotopes are used to investigate the role of biological production on the uptake and transfer of inorganic carbon to depth. A preferential uptake of the lighter 12C relative to the heavier 13C isotope during biological production leads to a fractionation of the 13C/12C isotopes in both the organic matter and the water column. This results in an enrichment of DI13C in the high productivity surface waters and a depletion of DI13C at depth. Physical processes including freshwater input, brine rejection, and water mass mixing are investigated through the measurement of oxygen isotopes. Differences in the carbon system across the study area due to both biological and physical processes are assessed using depth profiles of DI13C and related carbon system parameters.

  13. Stable isotope ratio (13C/12C mass spectrometry to evaluate carbon sources and sinks: changes and trends during the decomposition of vegetal debris from eucalyptus clone plantations (NW Spain

    Directory of Open Access Journals (Sweden)

    I. Fernandez

    2014-02-01

    Full Text Available Vegetal debris is known to participate in key soil processes such as the formation of soil organic matter (OM, also being a potential source of greenhouse gases to the atmosphere. However, its contribution to the isotopic composition of both the soil OM and the atmospheric carbon dioxide is not clear yet. Hence, the main objective of the present research is to understand the isotopic 13C changes and trends that take place during the successive biodegradative stages of decomposing soil organic inputs. By incubating bulk plant tissues for several months under laboratory controlled conditions, the kinetics of the CO2 releases and shifts in the 13C natural abundance of the solid residues were investigated using litter samples coming from forest plantations with a different clone (Anselmo: 1st clonal generation attained by morphological selection and Odiel: 2nd clonal generation genetically obtained of Eucalyptus globulus Labill. developed over granitic or schistic bedrocks and located in northwestern Spain. Significant isotopic variations with time were observed, probably due to the isotopically heterogeneous composition of these complex substrates in conjunction with the initial selective consumption of more easily degradable 13C-differentiated compounds during the first stages of the biodegradation, while less available or recalcitrant litter components were decomposed at later stages of biodegradation, generating products that have their own specific isotopic signatures. These results, which significantly differ depending on the type of clone, suggest that caution must be exercised when interpreting carbon isotope studies (at natural abundance levels since perturbations associated with the quality or chemical composition of the organic debris from different terrestrial ecosystems can have an important effect on the carbon stable isotope dynamics.

  14. 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 ...

  15. 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.

  16. The circumstellar shell of the post-AGB star HD 56126 the $^{12}C ^{12}C \\/ ^{12}C ^{13}C$isotope ratio and $^{12}C ^{16}O$ column density

    CERN Document Server

    Bakker, E J; Lambert, Eric J. Bakker & David L.

    1998-01-01

    We have made the first detection of circumstellar absorption lines of the 12C13C (Phillips) system 1-0 band and the 12C16O first-overtone 2-0 band in the spectrum of the post-AGB star HD56126 (IRAS07134+1005). The rotational temperatures are lower for molecules with a higher permanent dipole moment. Derived relative column densities ratios are 12C12C/12C13C=36+-13, 12C16O/(12C12C+12C13C)=606+-230, and 12C16O/(12C14N+13C14N)=475+-175. The isotopic exchange reaction for 12C12C is too slow to significantly alter the 12C12C/12C13C ratio and the 12C12C to 12C13C ratio a good measure of half the carbon isotope ratio: 12C/13C=2 X 12C12C/12C13C=72+-26. A fit of the 12C12C excitation model of van Dishoeck & Black (1982) to the relative population distribution of 12C12C yields n sigma / I = 3.3 +- 1.0 X 1e-14. At r=1e16cm this translates in n=1.7e7cm-3 and dM/dt=2.5e-4Msol/year.

  17. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the MARION DUFRESNE in the Indian Ocean from 1998-12-05 to 1998-12-27 (NODC Accession 0113574)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113574 includes biological, chemical, discrete sample, physical and profile data collected from MARION DUFRESNE in the Indian Ocean from 1998-12-05...

  18. 9,10-Dibromo-N-aryl-9,10-dihydro-9,10-[3,4]epipyrroloanthracene-12,14-diones: Synthesis and Investigation of Their Effects on Carbonic Anhydrase Isozymes I, II, IX, and XII.

    Science.gov (United States)

    Göksu, Haydar; Topal, Meryem; Keskin, Ali; Gültekin, Mehmet S; Çelik, Murat; Gülçin, İlhami; Tanc, Muhammet; Supuran, Claudiu T

    2016-06-01

    N-substituted maleimides were synthesized from maleic anhydride and primary amines. 1,4-Dibromo-dibenzo[e,h]bicyclo-[2,2,2]octane-2,3-dicarboximide derivatives (4a-f) were prepared by the [4+2] cycloaddition reaction of dibromoanthracenes with the N-substituted maleimide derivatives. The carbonic anhydrase (CA, EC 4.2.1.1) inhibitory effects of the new derivatives were assayed against the human (h) isozymes hCA I, II, IX, and XII. All tested bicyclo dicarboximide derivatives exhibited excellent inhibitory effects in the nanomolar range, with Ki values in the range of 117.73-232.87 nM against hCA I and of 69.74-111.51 nM against hCA II, whereas they were low micromolar inhibitors against hCA IX and XII. PMID:27174792

  19. 12 CFR 561.12 - Consumer credit.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Consumer credit. 561.12 Section 561.12 Banks... AFFECTING ALL SAVINGS ASSOCIATIONS § 561.12 Consumer credit. The term consumer credit means credit extended... association relies substantially upon other factors, such as the general credit standing of the...

  20. 12 CFR 229.12 - Availability schedule.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Availability schedule. 229.12 Section 229.12... Availability Policies § 229.12 Availability schedule. (a) Effective date. The availability schedule contained...)(1)(vii). (e) Extension of schedule for certain deposits in Alaska, Hawaii, Puerto Rico, and the...

  1. Dissolved inorganic carbon, total alkalinity, pH, and other variables collected from surface discrete observations using flow through pump and other instruments from M/V Skogafoss in the Northeast U.S. Shelf (off the southern coast of Greenland) and North Atlantic ocean during the Ocean Acidification Cruise SKO1501 from 2015-12-05 to 2015-12-10 (NCEI Accession 0154380)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Increasing amounts of atmospheric carbon dioxide from human industrial activities are causing changes in global ocean carbon chemistry. Through the SOOP program we...

  2. Dissolved inorganic carbon, total alkalinity, pH, and other variables collected from surface discrete observations using flow through pump and other instruments from M/V Skogafoss in the Northeast U.S. Shelf (off the southern coast of Greenland) and North Atlantic ocean during the Ocean Acidification Cruise SKO1406 from 2015-12-05 to 2015-12-10 (NCEI Accession 0154384)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Increasing amounts of atmospheric carbon dioxide from human industrial activities are causing changes in global ocean carbon chemistry. Through the SOOP program we...

  3. Electrochemical behavior and determination of vitamin B12 at a Multi-wall carbon nanotube modified electrode%VB12在多壁碳纳米管修饰电极上的电化学行为与含量测定

    Institute of Scientific and Technical Information of China (English)

    刘景; 王军; 全先高; 孙勤枢

    2013-01-01

    目的 研究了维生素B12在多壁碳纳米管修饰玻碳电极上的电化学行为与含量测定,以期建立一种直接测定维生素B12的电化学分析方法.方法 利用循环伏安法,通过改变缓冲体系、pH值、扫描速度、修饰剂用量等找到维生素B12的最佳测定条件,以便得出最佳测定结果.结果 修饰电极对维生素B12有良好的电催化活性,最佳缓冲体系为pH=4.4的醋酸-醋酸钠缓冲体系,最佳的修饰剂用量为20μl.与裸电极相比,多避碳纳米管能显著提高维生素的峰电流,且浓度在0.2×10-4 ~0.5×10-5 mol/L范围内峰电流与浓度呈良好的线性关系,检出限为1.0×10-7 mol/L.结论 多壁碳纳米管修饰玻碳电极对维生素B12有良好的电催化活性,可用于药物制剂中维生素B12的检测.

  4. 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.

  5. The early diagenetic and PETROphysical behaviour of recent cold-water CARbonate mounds in Deep Environments (PETROCARDE)

    OpenAIRE

    Foubert, A.; H. Pirlet; Thierens, M.; Van Mol, B.; Henriet, J.-P.; Swennen, R.

    2010-01-01

    Sub-recent cold-water carbonate mounds localized in deeper slope settings on the Atlantic continental margins cannot be any longer neglected in the study of carbonate systems. They clearly play a major role in the dynamics of mixed siliciclastic-carbonate and/or carbonate-dominated continental slopes. Carbonate accumulation rates of cold-water carbonate mounds are about 4 to 12 % of the carbonate accumulation rates of tropical shallow-water reefs but exceed the carbonate accumulation rates of...

  6. Control of the environmental inluences on THe-Trap on the example of the determination of the mass ratio of carbon-12 to oxygen-16; Kontrolle der Umwelteinfluesse auf THe-Trap am Beispiel der Bestimmung des Massenverhaeltnisses von Kohlenstoff-12 zu Sauerstoff-16

    Energy Technology Data Exchange (ETDEWEB)

    Streubel, Sebastian Dennis

    2014-04-16

    Tritium-Helium-3-Trap (THe-Trap) is a Penning-trap setup dedicated to measure the {sup 3}H to {sup 3}He mass ratio with a relative uncertainty of better than 10{sup -11}. This is 40 times more precise than the currently adopted value and, thus, will help to investigate possible systematic uncertainties of the Karlsruhe Tritium Neutrino experiment (KATRIN). To achieve the desired level of uncertainty, several environmental influences such as atmospheric pressure shifts and magnetic field fluctuations have to be suppressed. With the implemented stabilization system, the relative magnetic field drift could be reduced to a few 10{sup -12}/h for a time span of several weeks. Within the context of this thesis a mass ratio measurement of {sup 12}C{sup 4+} to {sup 16}O{sup 5+} was performed to characterize systematic effects. This measurement yielded a statistical uncertainty of 6.3 x 10{sup -11}, which can easily be improved with more statistics, i.e. a longer measurement time. While the systematic uncertainty for {sup 12}C{sup 4+}-ions were under control at the 10{sup -11} level, the systematic shifts could not be quantified for {sup 16}O{sup 5+} due to poor vacuum conditions. Without these corrections, a systematic uncertainty of 1.2.10{sup -10} could be achieved for the {sup 12}C/{sup 16}O mass ratio measurement.

  7. Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the DISCOVERY in the North Atlantic Ocean from 1990-06-12 to 1990-06-24 (NODC Accession 0113885)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113885 includes chemical, discrete sample, physical and profile data collected from DISCOVERY in the North Atlantic Ocean from 1990-06-12 to...

  8. Putting the Brakes on Carbon

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    More Chinese are adhering to a low-carbon lifestyle Han Xiangyu hesitates every day on whether he should climb the stairs or take the elevator to his 12th-floor apartment. He also ruminates on what tem-perature to set the thermostat and whether he should take a car or bus to go shopping.

  9. Sensitivity study in vitro in clinical isolated strains in the previous five years for erythromycin cyclic 11,12-carbonate%环酯红霉素对近5年临床分离菌株的体外敏感性研究

    Institute of Scientific and Technical Information of China (English)

    刘立涛; 孙韵; 卢涛; 谭显曙; 秦盼立; 周黎明

    2012-01-01

    Objective To investigate the antimicrobial susceptibility to clinically isolated strains in the previous five years and the drug resistance to antimicrobial agents so as to realize the antibacterial activity to erythromycin cyclic 11,12-carbonate in vitro. Methods Agar dilution method was used to detect the drug susceptibility to the 220 clinical isolates. Results Susceptibility test showed the resistance rates of Streptococcus pneumoniae, Streptococcus pyogenes, Staphylococcus aureus, Staphylococcus epidermidis and H. Influenzae to erythromycin cyclic 11,12-carbonate were 35.0%, 55.0%, 35.0%, 36.7% and 70.0%. The MIC50 of Staphylococcus aureus, Staphylococcus epidermidis and H. Influenzae were 1, 1, 32, 0.5 and 64ug/mL, and the MIC90 were 32, 8, 256, 32 and 128μg/mL. Conclusion The resistance of clinical isolates indicated that erythromycin cyclic 11,12-carbonate was comparative with azithromycin in the antibacterial activity, presenting no statistically significant between erythromycin cyclic 1 l,12-carbonate and azithromycin by SPSS17.0 (P>0.05).%目的 通过比较近五年临床分离菌株对多种抗菌药物的药物敏感性及耐药性研究,了解环酯红霉素的体外抗菌活性.方法 利用琼脂平板稀释法对临床分离220株细菌进行药敏性分析.结果 药物敏感性实验表明肺炎链球菌、化脓链球菌、金黄色葡萄球菌、表皮葡萄球菌和流感嗜血菌对环酯红霉素的耐药率分别为35.0%、55.0%、35.0%、36.7 %和70.0 %.肺炎链球菌、化脓链球菌、金黄色葡萄球菌、表皮葡萄球菌和流感嗜血菌对环酯红霉素的MIC50和MIC90分别为1、1、32、0.5、64μg/mL和32、8、256、32、128μg/mL.结论 经SPSS17.0统计分析后,发现临床分离菌株对环酯红霉素和阿奇霉素的耐药率表明两者的抗菌活性相当,不存在统计学差异(P>0.05).

  10. Influence of Different Heat Treatment Time on Carbon Migration and Microstructure of 12Cr1MoV/304 Joints%热处理时间对12Cr1MoV/304接头碳迁移和组织的影响

    Institute of Scientific and Technical Information of China (English)

    崔一哲; 李超

    2013-01-01

    奥氏体不锈钢与低合金耐热钢的焊接广泛应用于电站锅炉.为了研究高温时效对异质接头碳扩散以及组织的影响,模拟异质接头的工作环境,对异质接头进行500 ℃、不同时间的时效处理,观察熔合线两侧成分和组织的变化.结果表明,随着时效时间的增加,碳扩散的总量增加,母材热影响区贝氏体退化,转变成铁素体和索氏体,降低了接头的力学性能和使用寿命.%The welding of austenitic stainless steel with low alloy heat-resistant steel is widely used in the power station boiler. In order to research the influence of high-temperature aging on carbon diffusion of dissimilar joints and microstructure, it simulated the work environment of dissimilar jointers, after the aging treatment for the dissimilar joint at 500 °C at different time, along with observing the changes of the composition and the microstructure on both sides of the fusion zone, the result showed that with aging time increasing, the total quantity of carbon diffusion increase, the bainite in base metal degenerate and transform into ferrite and sorbite, which reduce the mechanical properties and service life of joint.

  11. 12 CFR 704.12 - Permissible services.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Permissible services. 704.12 Section 704.12 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS CORPORATE... teller machines, online transaction processing through a website, website hosting services,...

  12. Hydroisomerization-cracking of n-octane on heteropolyacid H{sub 3}PW{sub 12}O{sub 40} supported on ZrO{sub 2}, SiO{sub 2} and carbon

    Energy Technology Data Exchange (ETDEWEB)

    Yori, Juan C.; Grau, Javier M.; Benitez, Viviana M.; Sepulveda, Jorge [Instituto de Investigaciones en Catalisis y Petroquimica-INCAPE-(FIQ-UNL, CONICET), Santiago del Estero 2654, 3000 Santa Fe (Argentina)

    2005-05-26

    Heavy paraffins (n-C{sub 8-20}) are inexpensive refinery cuts of low octane number that can be upgraded to fuel-grade gasoline (C{sub 4}-C{sub 7}) by means of simultaneous hydrocracking and hydroisomerization over bifunctional metal/acid catalysts. The addition of Pt to pure tungstophosphoric acid (HPA) and supported on ZrO{sub 2} (HPA/Z), SiO{sub 2} (HPA/Si) and carbon (HPA/C) was studied in n-octane hydroisomerization-cracking reaction (300{sup o}C, 0.1MPa, WHSV=1h{sup -1}, H{sub 2}/n-C{sub 8}=6). Catalysts were characterized by specific surface area; temperature-programmed reduction, XRD measurements, FT-IR spectroscopy and temperature-programmed desorption of probe molecules (pyridine and 2,4,6-trimethyl pyridine). Supported HPA samples showed initial specific activity values expressed by mass unit of HPA higher than pure HPA. The order at 5min on stream was HPA/Z>HPA/C>HPA/Si {approx} pure HPA. All the samples deactivated by coking. The Pt addition had two effects: (1) increased surface proton content of the samples and thus their activity in n-C{sub 8} hydroconversion (a linear relationship between specific activity values and Bronsted acidity was found), (2) increased stability of samples allowing the attainments of a fast pseudo-steady state. The increase in activity due to Pt incorporation may be related with the formation of a new surface species of Pt into the HPA network. The fast stabilization of the samples was related to the inhibition of the coke precursors produced by the metallic Pt that remained on the surface of catalysts. Catalysts provides between 5 and 110 additional RON points over those of a model feedstock of n-octane. The RON gain is better correlated to the Bronsted acidity of samples, thus confirming that the production of branched isomers from long alkanes does not require highly acidic sites. Pt-HPA/Z showed the best catalytic performance with a RON gain of 101 points. A linear relation between the production of light gases (C{sub 1

  13. 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

  14. Vitamin B-12

    Science.gov (United States)

    MENU Return to Web version Vitamin B-12 Vitamin B-12 What is vitamin B-12? Vitamin B-12 is an important nutrient that is found naturally ... shellfish, meat, eggs, dairy products, and fortified foods. Vitamin B-12 helps make red blood cells and ...

  15. 40 CFR 600.101-12 - General applicability.

    Science.gov (United States)

    2010-07-01

    ... Section 600.101-12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) ENERGY POLICY FUEL ECONOMY AND CARBON-RELATED EXHAUST EMISSIONS OF MOTOR VEHICLES Fuel Economy Regulations for 1978... of 2012 and later model year automobiles. (b) Fuel economy and carbon-related emissions data....

  16. Innovation with carbon materials---A report on the annual world conference on carbon, Carbon 2015%炭材料的革新--记Carbon 2015国际炭会议

    Institute of Scientific and Technical Information of China (English)

    张强

    2015-01-01

    The annual world conference on carbon, Carbon 2015, was held in Dresden, Germany, and was hosted by the German Carbon Group and German Ceramic Society, during July 12~17, 2015. About 582 attendees from 40 countries participated in the conference, and 540 papers were accepted for discussion, including 4 plenary lectures, 256 oral presentations, and 280 posters in-volved in 12 topics, namely, activated carbon, biomass derived carbon, carbon black, carbon fiber and composites, granular/nucle-ar carbon, natural graphite, nanoforms, industrial, conversion process, physical &chemical properties, environmental &medical, and energy storage. Carbon fiber, graphite, carbon black, and carbon alloy were the subjects of the plenary lectures. The innovation of the traditional carbon materials and new nanocarbon, the critical role of carbon in energy, environment, and healthcare applica-tion, as well as the new insights on the relationship of structure and properties at the molecular scale were strongly considered in this event. Carbon materials required continuous innovation to meet the rising requirement of sustainable society.

  17. The Economic Implications of Introducing Carbon Taxes in South Africa

    DEFF Research Database (Denmark)

    Arndt, Thomas Channing

    2014-01-01

    national welfare and employment by about 1.2 and 0.6 percent, respectively. However, if trading partners unilaterally impose a carbon consumption tax on South African exports, then welfare/employment losses exceed those from a domestic carbon tax. South Africa can lessen welfare/employment losses...... by introducing its own border carbon adjustments. The mode for recycling carbon tax revenues strongly influences distributional outcomes, with tradeoffs between growth and equity....

  18. Catalytic Hydrogenolysis of 5-Carbon Sugar Alcohols

    Energy Technology Data Exchange (ETDEWEB)

    Zacher, Alan H.; Frye, John G.; Werpy, Todd A.; Miller, Dennis J.

    2005-01-01

    PNNL, in cooperation with the USDOE and CRADA partners, National Corn Growers Association and Archer Daniels Midland, has developed a new class of catalysts based on Nickel and Rhenium with very effective performance for highly selective, high conversion hydrogenolysis of five–carbon sugar alcohols to useful glycols. The Ni-Re catalyst appears to exhibit preferential hydrogenolysis of the carbon-carbon bonds of secondary carbons over primary carbons of the 5-carbon sugar alcohols tested. In addition, the catalyst has demonstrated significant and unique primary C-O bond hydrogenolysis activity in its ability to convert glycerol into 1,2- propylene glycol, which is then stable in the presence of this class of catalysts. The rhenium containing catalysts are found to have higher activity and better selectivity to desired glycols than previously reported catalysts. A continuous flow reactor lifetime test of over 1500 hours also demonstrated the requisite high stability for an industrially attractive process.

  19. Soft-templated synthesis of mesoporous carbon nanospheres and hollow carbon nanofibers

    Science.gov (United States)

    Cheng, Youliang; Li, Tiehu; Fang, Changqing; Zhang, Maorong; Liu, Xiaolong; Yu, Ruien; Hu, Jingbo

    2013-10-01

    Using coal tar pitch based amphiphilic carbonaceous materials (ACMs) as the precursor and amphiphilic triblock copolymer Plutonic P123 as the only soft template, carbon nanospheres with partially ordered mesopores and hollow carbon nanofibers were synthesized. The concentration of P123, cp, and the mass ratio of P123 to ACM, r, are the key parameters of controlling the shape of the as-prepared products. Mesoporous carbon nanospheres with diameter of 30-150 nm were prepared under the condition of cp = 13.3 g/L and r = 1.2. When cp = 26.7 g/L and r = 2, hollow carbon nanofibers with diameters of 50-200 nm and mesopores/macropores were obtained. Carbon nanospheres and hollow carbon fibers were amorphous materials. The mesoporous carbon nanospheres show good stability in the cyclic voltammograms and their specific capacitance at 10 mV s-1 is 172.1 F/g.

  20. Developing a Carbon Observing System

    Science.gov (United States)

    Moore, B., III

    2015-12-01

    There is a clear need to better understand and predict future climate change, so that science can more confidently inform climate policy, including adaptation planning and future mitigation strategies. Understanding carbon cycle feedbacks, and the relationship between emissions (fossil and land use) and the resulting atmospheric carbon dioxide (CO2) and methane (CH4) concentrations in a changing climate has been recognized as an important goal by the IPCC. The existing surface greenhouse gas observing networks provide accurate and precise measurements of background values, but they are not configured to target the extended, complex and dynamic regions of the carbon budget. Space Agencies around the globe are committed to CO2 and CH4 observations: GOSAT-1/2, OCO-2/3, MERLin, TanSat, and CarbonSat. In addition to these Low Earth Orbit (LEO) missions, a new mission in Geostationary Orbit (GEO), geoCARB, which would provide mapping-like measurements of carbon dioxide, methane, and carbon monoxide concentrations over major land areas, has been recently proposed to the NASA Venture Program. These pioneering missions do not provide the spatial/temporal coverage to answer the key carbon-climate questions at process relevant scales nor do they address the distribution and quantification of anthropogenic sources at urban scales. They do demonstrate, however, that a well-planned future system of system integrating space-based LEO and GEO missions with extensive in situ observations could provide the accuracy, spatial resolution, and coverage needed to address critical open issues in the carbon-climate system. Dr. Diana Wickland devoted enormous energy in developing a comprehensive apprioach to understand the global carbon cycle; she understood well that an integrated, coordinated, international approach is needed. This shines through in her recent contribution in co-chairing the team that produced the "CEOS Strategy for Carbon Observations from Space." A NASA-funded community

  1. Quantifying global terrestrial carbon influx and storage as stimulated by an increase in atmospheric carbon dioxide concentration

    OpenAIRE

    Luo, Yiqi

    1997-01-01

    EXTRACT (SEE PDF FOR FULL ABSTRACT): Measurements of spatial and temporal distributions of carbon dioxide concentration and carbon-13/carbon-12 ratio in the atmosphere suggest a strong biospheric carbon sink in terrestrial ecosystems. Quantifying the sink, however, has become an enormous challenge for Earth system scientists because of great uncertainties associated with biological variation and environmental heterogeneity in the ecosystems. This paper presents an approach that uses two d...

  2. Carbon classified?

    DEFF Research Database (Denmark)

    Lippert, Ingmar

    2012-01-01

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

  3. CARBONIZER TESTS WITH LAKELAND FEEDSTOCKS

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-09-01

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

  4. Carbon storage in Amazonian podzols

    Science.gov (United States)

    Montes, Celia; Lucas, Yves; Pereira, Osvaldo; Merdy, Patricia; Santin, Roberta; Ishida, Débora; du Gardin, Beryl; Melfi, Adolpho

    2014-05-01

    It has recently been discovered that Amazonian podzols may store much larger quantities of carbon than previously thought, particularly in their deep Bh horizons (over 13.6 Pg for Brazilian Amazonia alone [1]). Similarly high carbon stocks are likely to exist in similar climate/soil areas, mainly in Africa and in Borneo. Such carbon stocks raise the problem of their stability in response to changes in land use or climate. Any significant changes in vegetation cover would significantly alter the soil water dynamics, which is likely to affect organic matter turnover in soils. The direction of the change, however, is not clear and is likely to depend on the specific conditions of carbon storage and properties of the soils. It is reasonable to assume that the drying of the Bh horizons of equatorial podzols, which are generally saturated, will lead to an increase in C mineralization, although the extent of this increase has not yet been determined. These unknowns resulted in research programs, granted by the Brazilian FAPESP and the French Région PACA-ARCUS and ANR, dedicated improving estimates of the Amazonian podzol carbon stocks and to an estimate of its mineralisability. Eight test areas were determined from the analysis of remote sensing data in the larger Amazonian podzol region located in the High Rio Negro catchment and studied in detail. Despite the extreme difficulties in carrying out the field work (difficulties in reaching the study sites and extracting the soils), more than a hundred points were sampled. In all podzols the presence of a thick deep Bh was confirmed, sometimes to depths greater than 12 m. The Bh carbon was quantified, indicating that carbon stocks in these podzols are even higher than estimated recently [1]. References 1- Montes, C.R.; Lucas, Y.; Pereira, O.J.R.; Achard, R.; Grimaldi, M.; Mefli, A.J. Deep plant?derived carbon storage in Amazonian podzols. Biogeosciences, 8, 113?120, 2011.

  5. Carbonate Ion Effects on Coccolith Carbon and Oxygen Isotopes

    Science.gov (United States)

    Ziveri, P.; Probert, I.; Stoll, H. M.

    2006-12-01

    The stable oxygen and carbon isotopic composition of biogenic calcite constitutes one of the primary tools used in paleoceanographic reconstructions. The δ18O of shells of ocean floor microfossils and corals reflects the composition of the paleo-seawater as they use the oxygen to build up their calcite and aragonite shells. The δ13C is used to reconstruct variations in the carbon isotopic composition of dissolved inorganic carbon in the ocean, which is controlled by biological productivity through the removal of isotopically light carbon in organic matter. To be effective and sensitive tools for understanding photic zone processes it is first necessary to understand the various biological fractionations associated with carbonate precipitation. To date, isotopic fractionation models are mainly based on foraminifera and corals but not on coccoliths, tiny plates produced by coccolithophore algae, which are often the most dominant carbonate contributors to pelagic sediments. As photosynthetic organisms, their chemistry can provide a sensitive tool for understanding photic zone processes. Coccoliths may be the most important carbonate phase for geochemical analysis in sediments where foraminifera are less common and/or core material is limited, such as in subpolar regions and for Early Cenozoic and Mesozoic sediments. Here we report experimental results on a common living coccolithophore species showing that the 13C/12C and 18O/16O ratios decrease with the increase of HCO^{3-} (CO32-). The selected species are among the heaviest calcifying extant coccolithophores and are major contributors to present coccolith carbonate export production. Because coccolithophores are photosynthetic organisms that calcify intracellularly in specialized vesicles, the challenge lies in ascertaining how kinetic and thermodynamic processes of isotopic fractionation are linked to cellular carbon "transport" and carbonate precipitation. This is a daunting challenge since studies have not

  6. 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

  7. Vitamin B12

    Science.gov (United States)

    ... Consumer Datos en español Health Professional Other Resources Vitamin B12 Fact Sheet for Consumers Have a question? ... out more about vitamin B12? Disclaimer What is vitamin B12 and what does it do? Vitamin B12 ...

  8. 40 CFR 70.12 - Enforceable commitments for further actions addressing greenhouse gases (GHGs).

    Science.gov (United States)

    2010-07-01

    ... actions addressing greenhouse gases (GHGs). 70.12 Section 70.12 Protection of Environment ENVIRONMENTAL... commitments for further actions addressing greenhouse gases (GHGs). (a) Definitions. (1) Greenhouse Gases... six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons,...

  9. 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...

  10. 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;

    2015-01-01

    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......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...

  11. Determination of dopamine by carboxylic multi-wall carbon nanotubes/vitamin B12 modified electrode%羧化多壁碳纳米管/维生素B12修饰电极测定多巴胺

    Institute of Scientific and Technical Information of China (English)

    刘景; 王军; 孔凡栋

    2014-01-01

    制备了羧化多壁碳纳米管/维生素B12修饰玻碳电极,利用循环伏安法研究了多巴胺(DA)在此修饰电极上的电化学行为.结果表明,在pH为6.48的PBS缓冲溶液中,此修饰电极对DA有很强的电催化作用,明显增强了峰电流,峰电位差△Ep由196 mV减小至69 mV,提高了电极反应的可逆性.在优化实验条件下,此修饰电极所测DA氧化峰电流与DA浓度在1.0×10-5 ~5.0×10-5 mol/L及1.0×10-3 ~1.0×10-2 moi/L范围内均呈线性,线性方程分别为y=373.78x+ 71.726(R2=0.995 8)和y=57.2x +365.22(R2=0.986 6),其中低浓度区的相关系数较高,应用于实际样品测定时结果较为满意.检测限可达8.0×10-8 mol/L.

  12. Matrix metalloproteinase-12 (MMP-12) in osteoclasts

    DEFF Research Database (Denmark)

    Hou, Peng; Troen, Tine; Ovejero, Maria C;

    2004-01-01

    Osteoclasts require matrix metalloproteinase (MMP) activity and cathepsin K to resorb bone, but the critical MMP has not been identified. Osteoclasts express MMP-9 and MMP-14, which do not appear limiting for resorption, and the expression of additional MMPs is not clear. MMP-12, also called...... bone show MMP-12 expression in osteoclasts in calvariae and long bones. We also demonstrate that recombinant MMP-12 cleaves the putative functional domains of osteopontin and bone sialoprotein, two bone matrix proteins that strongly influence osteoclast activities, such as attachment, spreading...

  13. 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

  14. Synthesis and Characterization of Cobalt-Carbon Core-Shell Microspheres in Supercritical Carbon Dioxide System

    Institute of Scientific and Technical Information of China (English)

    Jun-song Yang; Qian-wang Chen

    2008-01-01

    The synthesis of cobalt-carbon core-shell microspheres in supercritical carbon dioxide system was investigated. Cobalt-carbon core-shell microspheres with diameter of about 1μm were prepared at 350℃ for 12 h in a closed vessel containing an appropriate amount of bis(cyclopentadienyl)cobalt powder and dry ice.Characterization by a variety of techniques,including X-ray powder diffraction,X-ray photoelectron spectroscopy,Transmission electron microscope,Fourier transform infrared spectrum and Raman spectroscopy analysis reveals that each cobalt-carbon core-shell microsphere is made up of an amorphous cobalt core with diameter less than 1 μm and an amorphous carbon shell with thickness of about 200 nm.The possible growth mechanism of cobalt-carbon core-shell microspheres is discussed,based on the pyrolysis of bis(cyclopentadienyl)cobalt in supercritical carbon dioxide and the deposition of carbon or carbon clusters with odd electrons on the surface of magnetic cobalt cores due to magnetic attraction.Magnetic measurements show 141.41 emu/g of saturation magnetization of a typical sample,which is lower than the 168 emu/g of the corresponding metal cobalt bulk material.This is attributed to the considerable mass of the carbon shell and amorphous nature of the magnetic core.Control of magnetism in the cobalt-carbon core-shell microspheres was achieved by annealing treatments.

  15. Polyacrylonitrile/carbon nanotube composite fibers: Reinforcement efficiency and carbonization studies

    Science.gov (United States)

    Chae, Han Gi

    Polyacrylonitrile (PAN)/carbon nanotube (CNT) composite fibers were made using various processing methods such as conventional solution spinning, gel spinning, and bi-component gel spinning. The detailed characterization exhibited that the smaller and longer CNT will reinforce polymer matrix mostly in tensile strength and modulus, respectively. Gel spinning combined with CNT also showed the promising potential of PAN/CNT composite fiber as precursor fiber of the next generation carbon fiber. High resolution transmission electron microscopy showed the highly ordered PAN crystal layer on the CNT, which attributed to the enhanced physical properties. The subsequent carbonization study revealed that carbonized PAN/CNT fibers have at least 50% higher tensile strength and modulus as compared to those of carbonized PAN fibers. Electrical conductivity of CNT containing carbon fiber was also 50% higher than that of carbonized PAN fiber. In order to have carbon fiber with high tensile strength, the smaller diameter precursor fiber is preferable. Bi-component gel spinning produced 1-2 mum precursor fiber, resulting in ˜1 mum carbon fiber. The tensile strength of the carbonized bi-component fiber (islands fibers) is as high as 6 GPa with tensile modulus of ˜500 GPa. Further processing optimization may lead to the next generation carbon fiber.

  16. 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...

  17. 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 ...

  18. 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 ...

  19. 12C+12C reactions at astrophysical energies: Tests of targets behaviour under beam bombardment

    International Nuclear Information System (INIS)

    12C(12C,α)20Ne and 12C(12C,p)23Na are the most important reactions during the carbon burning phase in stars. Direct measurements at the relevant astrophysical energy (E=1.5±0.3MeV) are very challenging because of the extremely small cross sections involved and of the high beam-induced background originating from impurities in the targets. In addition, persistent resonant structures at low energies are not well understood and make the extrapolation of the cross section from high energy data very uncertain. As a preliminary step towards the measurements of the 12C(12C,α)20Ne and 12C(12C,p)23Na reactions we intend to investigate the behaviour of targets under beam bombardment, specifically the quantitative measurement of hydrogen and deuterium content of highly pure stable carbon targets in relation to target temperature. Experiments are taking place at the CIRCE accelerator in Caserta, Italy and preliminary results are presented here

  20. 40 CFR 600.201-12 - General applicability.

    Science.gov (United States)

    2010-07-01

    ... Section 600.201-12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) ENERGY POLICY FUEL ECONOMY AND CARBON-RELATED EXHAUST EMISSIONS OF MOTOR VEHICLES Fuel Economy Regulations for 1977 and Later Model Year Automobiles-Procedures for Calculating Fuel Economy Values § 600.201-12...

  1. Carbon isotopic fractionation in heterotrophic microbial metabolism

    Science.gov (United States)

    Blair, N.; Leu, A.; Munoz, E.; Olsen, J.; Kwong, E.; Des Marais, D.

    1985-01-01

    Differences in the natural-abundance carbon stable isotopic compositions between products from aerobic cultures of Escherichia coli K-12 were measured. Respired CO2 was 3.4 percent depleted in C-13 relative to the glucose used as the carbon source, whereas the acetate was 12.3 percent enriched in C-13. The acetate C-13 enrichment was solely in the carboxyl group. Even though the total cellular carbon was only 0.6 percent depleted in C-13, intracellular components exhibited a significant isotopic heterogeneity. The protein and lipid fractions were -1.1 and -2.7 percent, respectively. Aspartic and glutamic acids were -1.6 and +2.7 percent, respectively, yet citrate was isotopically identical to the glucose. Probable sites of carbon isotopic fractionation include the enzyme, phosphotransacetylase, and the Krebs cycle.

  2. 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.

  3. 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...

  4. 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

  5. A multiple of 12 for Avogadro

    CERN Document Server

    Fraundorf, P

    2012-01-01

    The new International System of Units may let us select an integer value for Avogadro's number. Some might prefer an integer that's divisible by 12, so that an integer number of $^{12}C$ atoms may be associated (at least to first order) with a gram's mass. For educational as well as practical reasons it may also help to choose a {\\em physically-meaningful} definition, within measurement error of the current numeric value. Cubes of diamond face-centered-cubic Si and (much rarer) face-centered-cubic C have been proposed, but these structures don't have naturally occurring facets (or numbers of atoms generally divisible by 12). We show here that graphite prisms formed by stacking $m$ hexagonal graphene sheets, with $m$ Carbon-12 atoms on each side, are a natural solution to this challenge.

  6. Organic chemistry of Murchison meteorite: Carbon isotopic fractionation

    Science.gov (United States)

    Yuen, G. U.; Blair, N. E.; Desmarais, D. J.; Cronin, J. R.; Chang, S.

    1986-01-01

    The carbon isotopic composition of individual organic compounds of meteoritic origin remains unknown, as most reported carbon isotopic ratios are for bulk carbon or solvent extractable fractions. The researchers managed to determine the carbon isotopic ratios for individual hydrocarbons and monocarboxylic acids isolated from a Murchison sample by a freeze-thaw-ultrasonication technique. The abundances of monocarboxylic acids and saturated hydrocarbons decreased with increasing carbon number and the acids are more abundant than the hydrocarbon with the same carbon number. For both classes of compounds, the C-13 to C-12 ratios decreased with increasing carbon number in a roughly parallel manner, and each carboxylic acid exhibits a higher isotopic number than the hydrocarbon containing the same number of carbon atoms. These trends are consistent with a kinetically controlled synthesis of higher homologues for lower ones.

  7. Regiospecificity of Chlorophenol Reductive Dechlorination by Vitamin B12s

    OpenAIRE

    Smith, Mark H.; Woods, Sandra L.

    1994-01-01

    Vitamin B12, reduced by titanium (III) citrate to vitamin B12s, catalyzes the reductive dechlorination of chlorophenols. Reductive dechlorination of pentachlorophenol and of all tetrachlorophenol and trichlorophenol isomers was observed. Reaction of various chlorophenols with vitamin B12 favored reductive dechlorination at positions adjacent to another chlorinated carbon, but chlorines ortho to the hydroxyl group of a phenol were particularly resistant to reductive dechlorination, even if the...

  8. From carbon nanotubes to carbon atomic chains

    Science.gov (United States)

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

    2010-10-01

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

  9. Carbon Footprint of Beef Cattle

    Directory of Open Access Journals (Sweden)

    Jim Dyer

    2012-12-01

    Full Text Available The carbon footprint of beef cattle is presented for Canada, The United States, The European Union, Australia and Brazil. The values ranged between 8 and 22 kg CO2e per kg of live weight (LW depending on the type of farming system, the location, the year, the type of management practices, the allocation, as well as the boundaries of the study. Substantial reductions have been observed for most of these countries in the last thirty years. For instance, in Canada the mean carbon footprint of beef cattle at the exit gate of the farm decreased from 18.2 kg CO2e per kg LW in 1981 to 9.5 kg CO2e per kg LW in 2006 mainly because of improved genetics, better diets, and more sustainable land management practices. Cattle production results in products other than meat, such as hides, offal and products for rendering plants; hence the environmental burden must be distributed between these useful products. In order to do this, the cattle carbon footprint needs to be reported in kg of CO2e per kg of product. For example, in Canada in 2006, on a mass basis, the carbon footprint of cattle by-products at the exit gate of the slaughterhouse was 12.9 kg CO2e per kg of product. Based on an economic allocation, the carbon footprints of meat (primal cuts, hide, offal and fat, bones and other products for rendering were 19.6, 12.3, 7 and 2 kg CO2e per kg of product, respectively.

  10. 12 CFR 3.12 - Procedures.

    Science.gov (United States)

    2010-01-01

    ... circumstances affecting the bank's capital adequacy or its ability to reach the required minimum capital ratios... COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY MINIMUM CAPITAL RATIOS; ISSUANCE OF DIRECTIVES Establishment of Minimum Capital Ratios for an Individual Bank § 3.12 Procedures. (a) Notice. When the...

  11. 12 CFR 563e.12 - Definitions.

    Science.gov (United States)

    2010-01-01

    ... (13 CFR 121.301) or have gross annual revenues of $1 million or less; or (4) Activities that... Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY COMMUNITY REINVESTMENT General § 563e.12... purpose community development. (u) Small savings association—(1) Definition. Small savings...

  12. 12 CFR 12.2 - Definitions.

    Science.gov (United States)

    2010-01-01

    ... fixed or revolving, that by their terms convert into cash within a finite time period plus any rights or.... (b) Collective investment fund means any fund established pursuant to 12 CFR 9.18. (c) Completion of..., bank as trustee acting as shareholder of record for the purchase or sale of securities, or issuer...

  13. Soil carbon model alternatives for ECHAM5/JSBACH climate model: Evaluation and impacts on global carbon cycle estimates

    DEFF Research Database (Denmark)

    Thum, T.; Raisanen, P.; Sevanto, S.;

    2011-01-01

    The response of soil organic carbon to climate change might lead to significant feedbacks affecting global warming. This response can be studied by coupled climate-carbon cycle models but so far the description of soil organic carbon cycle in these models has been quite simple. In this work we used......, the results were ambiguous and the RMS error was 12% larger for Yasso07 than for CBALANCE. As a response to climatic changes, Yasso07 showed greater release of soil carbon to the atmosphere than the original model formulation during the years 1977-2006. This emphasizes the need for better understanding...... the coupled climate-carbon cycle model ECHAM5/JSBACH (European Center/Hamburg Model 5/Jena Scheme for Biosphere-Atmosphere Coupling in Hamburg) with two different soil carbon modules, namely (1) the original soil carbon model of JSBACH called CBALANCE and (2) a new soil carbon model Yasso07, to study...

  14. A comparative study of EMI shielding properties of carbon nanofiber and multi-walled carbon nanotube filled polymer composites.

    Science.gov (United States)

    Yang, Yonglai; Gupta, Mool C; Dudley, Kenneth L; Lawrence, Roland W

    2005-06-01

    Electromagnetic interference shielding properties of carbon nanofiber- and multi-walled carbon nanotube-filled polystyrene composites were investigated in the frequency range of 8.2-12.4 GHz (X-band). It was observed that the shielding effectiveness of composites was frequency independent, and increased with the increase of carbon nanofiber or nanotube loading. At the same filler loading, multi-walled carbon nanotube-filled polystyrene composites exhibited higher shielding effectiveness compared to those filled with carbon nanofibers. In particular, carbon nanotubes were more effective than nanofibers in providing high EMI shielding at low filler loadings. The experimental data showed that the shielding effectiveness of the composite containing 7 wt% carbon nanotubes could reach more than 26 dB, implying that such a composite can be used as a potential electromagnetic interference shielding material. The dominant shielding mechanism of carbon nanotube-filled polystyrene composites was also discussed. PMID:16060155

  15. Carbon nanotube composite materials

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-03-24

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

  16. 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...

  17. 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

  18. Mesoporous carbon materials

    Science.gov (United States)

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

    2014-09-09

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

  19. 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.

  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. Synthesis of mesoporous carbons using ordered and disordered mesoporous silica templates and polyacrylonitrile as carbon precursor.

    Science.gov (United States)

    Kruk, Michal; Dufour, Bruno; Celer, Ewa B; Kowalewski, Tomasz; Jaroniec, Mietek; Matyjaszewski, Krzysztof

    2005-05-19

    Mesoporous carbons were synthesized from polyacrylonitrile (PAN) using ordered and disordered mesoporous silica templates and were characterized using transmission electron microscopy (TEM), powder X-ray diffraction, nitrogen adsorption, and thermogravimetry. The pores of the silica templates were infiltrated with carbon precursor (PAN) via polymerization of acrylonitrile from initiation sites chemically bonded to the silica surface. This polymerization method is expected to allow for a uniform filling of the template with PAN and to minimize the introduction of nontemplated PAN, thus mitigating the formation of nontemplated carbon. PAN was stabilized by heating to 573 K under air and carbonized under N2 at 1073 K. The resulting carbons exhibited high total pore volumes (1.5-1.8 cm3 g(-1)), with a primary contribution of the mesopore volume and with relatively low microporosity. The carbons synthesized using mesoporous templates with a 2-dimensional hexagonal structure (SBA-15 silica) and a face-centered cubic structure (FDU-1 silica) exhibited narrow pore size distributions (PSDs), whereas the carbon synthesized using disordered silica gel template had broader PSD. TEM showed that the SBA-15-templated carbon was composed of arrays of long, straight, or curved nanorods aligned in 2-D hexagonal arrays. The carbon replica of FDU-1 silica appeared to be composed of ordered arrays of spheres. XRD provided evidence of some degree of ordering of graphene sheets in the carbon frameworks. Elemental analysis showed that the carbons contain an appreciable amount of nitrogen. The use of our novel infiltration method and PAN as a carbon precursor allowed us to obtain ordered mesoporous carbons (OMCs) with (i) very high mesopore volume, (ii) low microporosity, (iii) low secondary mesoporosity, (iv) large pore diameter (8-12 nm), and (v) semi-graphitic framework, which represent a desirable combination of features that has not been realized before for OMCs. PMID:16852101

  2. 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. 

  3. Deciphering Carbon Isotope Excursions in Separated Biogenic and Diagenetic Carbonates

    Science.gov (United States)

    Hermoso, M.; Minoletti, F.; Hesselbo, S.; Jenkyns, H.; Rickaby, R.; Diester-Haass, L.; Delsate, D.

    2008-12-01

    The long-term evolution of the carbon-isotope ratio in the sedimentary archive is classically linked with changes in primary productivity and organic matter burial. There have been sudden and pronounced shifts, so-called Carbon Isotope Excursions (CIEs) in the long-term trends as evidenced by synchronous shifts from various basins. These geochemical perturbations may have various explanations such as changes of the efficiency of the carbon sink; sudden infusion of isotopically-light carbon into the Ocean-Atmosphere system; or advection of 12C-rich source from bottom water in a stratified water column. Beside the record of primary changes in seawater chemistry, a possible diagenetic overprint may also mime such CIEs in the sedimentary record. The aim of this contribution is to illustrate through three critical intervals (the Early Toarcian, the K-P boundary and the Mid-Miocene Montery Event) how the various micron-sized sedimentary particles specifically record these CIEs, which are respectively associated with major paleoceanographical events. New techniques for getting monotaxic calcareous nannofossil assemblages from the sediment (Minoletti et al., accepted) enable the isotopic measurement at various depths within the surface water and from bottom water by analyzing early diagenetic precipitations (rhombs and micarbs). The integration of these high-resolution isotopic signals in terms of amplitudes affords to recognize diagenetic artifacts in some sections displaying coeval decrease in the carbonate content. For both Early Toarcian and K-P events, corroborative records of CIE records in both primary calcite and bottom water carbonate indicate a global C-isotope perturbation of the water column. For the Monterey event, the evolution of calcareous nannoplankton and the foraminifera isotopic records are in overall agreement, but in detail, the coccolith-discoaster and foraminifer ratio in the sediment, related to environmental changes, is likely to produce isotopic

  4. Adsorption of Carbon Dioxide on Activated Carbon

    Institute of Scientific and Technical Information of China (English)

    Bo Guo; Liping Chang; Kechang Xie

    2006-01-01

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

  5. Synthesis and Conformation of cis-1,2-Disubstituted Cyclododecene

    Institute of Scientific and Technical Information of China (English)

    HAN,Xiang-Yu(韩翔宇); WANG,Ming-An(王明安); LIANG,Xiao-Mei(梁晓梅); WANG,Dao-Quan(王道全)

    2004-01-01

    Eight 1,2-disubstituted cyclododecenes were synthesized from a-alkoxycarbonyl-cyclododecanone and alkyl chloroformate. Their configuration and conformation determined by IR, NMR spectroscopy and X-ray diftraction analysis showed that the carbon-carbon double bond of all of the synthesized compounds has cis-configuration, and the ring skeleton of their preferred conformation is [lene2333] in solid, and they may adopt two different [lene2333]conformations, which exist in a dynamic equilibrium in solution.

  6. Characterization of Carbon Mat Thermoplastic Composites: Flow and Mechanical Properties

    OpenAIRE

    Caba, Aaron C.

    2005-01-01

    Carbon mat thermoplastics (CMT) consisting of 12.7 mm or 25.4 mm long, 7.2 micrometer diameter, chopped carbon fibers in a polypropylene (PP) or poly(ethylene terephthalate) (PET) thermoplastic matrix were manufactured using the wetlay technique. This produces a porous mat with the carbon fibers well dispersed and randomly oriented in a plane. CMT composites offer substantial cost and weight savings over typical steel construction in new automotive applications. In production vehicles, aut...

  7. 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

  8. 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.

  9. Carbon-cluster mass calibration at SHIPTRAP

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhuri, Ankur

    2007-12-10

    A carbon-cluster ion source has been installed and tested at SHIPTRAP, the Penning-trap mass spectrometer for mass measurements of heavy elements at GSI/Darmstadt, Germany. A precision mass determination is carried out by measuring the ion cyclotron frequency {omega}{sub c}=qB=m, where q/m is the charge-to-mass ratio of the ion and B is the magnetic field. The mass of the ion of interest is obtained from the comparison of its cyclotron frequency {omega}{sub c} with that of a well-known reference ion. Carbon clusters are the mass reference of choice since the unified atomic mass unit is defined as 1/12 of the mass of the {sup 12}C atom. Thus the masses of carbon clusters {sup 12}C{sub n}, n=1,2,3,.. are multiples of the unified atomic mass unit. Carbon-cluster ions {sup 12}C{sub n}{sup +}, 5{<=}n{<=}23, were produced by laser-induced desorption and ionization from a carbon sample. Carbon clusters of various sizes ({sup 12}C{sub 7}{sup +}, {sup 12}C{sub 9}{sup +}, {sup 12}C{sub 10}{sup +}, {sup 12}C{sub 11}{sup +}, {sup 12}C{sub 12}{sup +}, {sup 12}C{sub 15}{sup +}, {sup 12}C{sub 18}{sup +}, {sup 12}C{sub 19}{sup +}, {sup 12}C{sub 20}{sup +}) were used for an investigation of the accuracy of SHIPTRAP covering a mass range from 84 u to 240 u. To this end the clusters were used both as ions of interest and reference ions. Hence the true values of the frequency ratios are exactly known. The mass-dependent uncertainty was found to be negligible for the case of (m-m{sub ref})<100 u. However, a systematic uncertainty of 4.5 x 10{sup -8} was revealed. In addition, carbon clusters were employed for the first time as reference ions in an on-line studies of short-lived nuclei. Absolute mass measurements of the radionuclides {sup 144}Dy, {sup 146}Dy and {sup 147}Ho were performed using {sup 12}C{sub 11}{sup +} as reference ion. The results agree with measurements during the same run using {sup 85}Rb{sup +} as reference ion. The investigated radionuclides were produced in the

  10. Vitamin B12

    Science.gov (United States)

    ... and other dairy foods Some breakfast cereals and nutritional yeasts To find out if vitamin B12 has been added to a food product, check the nutrition fact panel on the food label. The body absorbs animal sources of vitamin B12 ...

  11. Vitamin B-12

    Science.gov (United States)

    Vitamin B-12 is a cofactor for 2 enzymes. In the cytoplasm, methionine synthase requires vitamin B-12 in the form of methylcobalamin and catalyzes the conversion of homocysteine to methionine by transfer of a methyl group from methyltetrahydrofolate.This enzyme links the methylation pathway through ...

  12. Safety Code A12

    CERN Multimedia

    SC Secretariat

    2005-01-01

    Please note that the Safety Code A12 (Code A12) entitled "THE SAFETY COMMISSION (SC)" is available on the web at the following url: https://edms.cern.ch/document/479423/LAST_RELEASED Paper copies can also be obtained from the SC Unit Secretariat, e-mail: sc.secretariat@cern.ch SC Secretariat

  13. Long-range transport of continentally-derived particulate carbon in the marine atmosphere: evidence from stable carbon isotope studies

    OpenAIRE

    Cachier, Héléne; BUAT-MÉNARD, PATRICK; Fontugne, Michel; Chesselet, Roger

    2011-01-01

    Since 1979, we have investigated marine and non-marine sources of particulate carbon in the marine atmosphere from measurements of carbon concentration and isotopic composition 13C/12C). Aerosol samples were collected, mostly during the Sea/Air Exchange (SEAREX) Program experiments, in the northern and southern hemispheres (Sargasso Sea, Enewetak Atoll, Peru upwelling, American Samoa, New Zealand, Amsterdam Island). The concentration and the isotopic composition of particulate carbon of marin...

  14. Synthesis of carbon-14 labeled doxylamine succinate

    International Nuclear Information System (INIS)

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

  15. China Firmly Committed to Low Carbon Economy

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ The creation of a "low carbon" economy that will provide jobs and clean up industry is now a crucial policy objective for countries trying to spend their way out of the world economic downturn. A recent report by HSBC calculates that the United States is allocating 12 per cent of its fiscal stimulus to the green economy and China, 34per cent.

  16. The Photochemical Stability of Carbonates on Mars

    Science.gov (United States)

    Quinn, Richard; Zent, Aaron P.; McKay, Christopher P.

    2006-08-01

    Carbonates, predominately MgCO3, have been spectroscopically identified at a level of 2-5% in martian dust. However, in spite of this observation, and a large number of climate studies that suggest 1 to several bars of CO2 should be sequestered in carbonate rocks, no outcropscale exposures of carbonate have been detected anywhere on Mars to date. To address one hypothesis for this long-standing puzzle, the effect of ultraviolet (UV) light on the stability of calcium carbonate in a simulated martian atmosphere was experimentally investigated. Using 13C-labeled calcite, we found no experimental evidence of the UV photodecomposition of calcium carbonate in a simulated martian atmosphere. Extrapolating the lower limit of detection of our experimental system to an upper limit of carbonate decomposition on Mars yields a quantum efficiency of 3.5 × 10-8 molecules/photon over the wavelength interval of 190-390 nm and a maximum UV photodecomposition rate of 1.2 × 10-13 kg m-2 s-1 from a calcite surface. The maximum loss of bulk calcite due to this process would be 2.5 nm year-1 (Mars year). However, calcite is expected to be thermodynamically stable on the surface of Mars, and potential UV photodecomposition reaction mechanisms indicate that, though calcium carbonate may decompose under vacuum, it would be stable in a CO2 atmosphere. Given the expected stability of carbonate on Mars and our inability to detect carbonate decomposition, we conclude that it is unlikely that the apparent absence of extensive carbonate deposits on the martian surface is due to UV photodecomposition in the current environment.

  17. A Thermal Model for Carbon Nanotube Interconnects

    Directory of Open Access Journals (Sweden)

    Clay Mayberry

    2013-04-01

    Full Text Available In this work, we have studied Joule heating in carbon nanotube based very large scale integration (VLSI interconnects and incorporated Joule heating influenced scattering in our previously developed current transport model. The theoretical model explains breakdown in carbon nanotube resistance which limits the current density. We have also studied scattering parameters of carbon nanotube (CNT interconnects and compared with the earlier work. For 1 µm length single-wall carbon nanotube, 3 dB frequency in S12 parameter reduces to ~120 GHz from 1 THz considering Joule heating. It has been found that bias voltage has little effect on scattering parameters, while length has very strong effect on scattering parameters.

  18. 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...

  19. 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...

  20. 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 ...

  1. 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...

  2. 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 ...

  3. 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 ...

  4. 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 ...

  5. 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.

  6. A Novel Polyamide 12 Polymerization System and its Use for a LCM-process to Produce CFRP

    OpenAIRE

    Rosso, Patrick; Friedrich, Klaus; Wollny, Andreas; Mülhaupt, Rolf

    2005-01-01

    Abstract The aim of this study was to investigate the scope of the recently developed polymerization molding system for polyamide 12 (PA12), especially with respect to the formation of carbon fiber-reinforced PA12 composites. Initial screening of PA12 composite formation was performed by means of an internal mixer in order to identify the suitable type of surface-treated carbon fiber (CF). The content of re...

  7. Vitamin B12 level

    Science.gov (United States)

    ... sprue Chronic myelogenous leukemia (CML) Cirrhosis Delirium Dementia Dementia due to metabolic causes Hepatitis Hyperthyroidism Malabsorption Pernicious anemia Polycythemia vera Reticulocyte count Vitamin B12 Update Date 2/24/2014 Updated by: ...

  8. 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.

  9. Chemical synthesis and biological evaluation of cis- and trans-12,13-cyclopropyl and 12,13-cyclobutyl epothilones and related pyridine side chain analogues

    DEFF Research Database (Denmark)

    Nicolaou, K C; Namoto, K; Ritzén, A;

    2001-01-01

    The design, chemical synthesis, and biological evaluation of a series of cyclopropyl and cyclobutyl epothilone analogues (3-12, Figure 1) are described. The synthetic strategies toward these epothilones involved a Nozaki-Hiyama-Kishi coupling to form the C15-C16 carbon-carbon bond, an aldol...

  10. 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.

  11. Carbon nanotube quantum dots

    NARCIS (Netherlands)

    Sapmaz, S.

    2006-01-01

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

  12. 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…

  13. 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.

  14. The Australian terrestrial carbon budget

    Directory of Open Access Journals (Sweden)

    V. Haverd

    2013-02-01

    Full Text Available This paper reports a study of the full carbon (C-CO2 budget of the Australian continent, focussing on 1990–2011 in the context of estimates over two centuries. The work is a contribution to the RECCAP (REgional Carbon Cycle Assessment and Processes project, as one of numerous regional studies. In constructing the budget, we estimate the following component carbon fluxes: net primary production (NPP; net ecosystem production (NEP; fire; land use change (LUC; riverine export; dust export; harvest (wood, crop and livestock and fossil fuel emissions (both territorial and non-territorial. Major biospheric fluxes were derived using BIOS2 (Haverd et al., 2012, a fine-spatial-resolution (0.05° offline modelling environment in which predictions of CABLE (Wang et al., 2011, a sophisticated land surface model with carbon cycle, are constrained by multiple observation types. The mean NEP reveals that climate variability and rising CO2 contributed 12 ± 24 (1σ error on mean and 68 ± 15 TgC yr−1, respectively. However these gains were partially offset by fire and LUC (along with other minor fluxes, which caused net losses of 26 ± 4 TgC yr−1 and 18 ± 7 TgC yr−1, respectively. The resultant net biome production (NBP is 36 ± 29 TgC yr−1, in which the largest contributions to uncertainty are NEP, fire and LUC. This NBP offset fossil fuel emissions (95 ± 6 TgC yr−1 by 38 ± 30%. The interannual variability (IAV in the Australian carbon budget exceeds Australia's total carbon emissions by fossil fuel combustion and is dominated by IAV in NEP. Territorial fossil fuel emissions are significantly smaller than the rapidly growing fossil fuel exports: in 2009–2010, Australia exported 2.5 times more carbon in fossil fuels than it emitted by burning fossil fuels.

  15. Monte-Carlo simulation of soil carbon measurements by inelastic neutron scattering

    Science.gov (United States)

    Measuring soil carbon is critical for assessing the potential impact of different land management practices on carbon sequestration. The inelastic neutron scattering (INS) of fast neutrons (with energy around 14 MeV) on carbon-12 nuclei produces gamma rays with energy of 4.43 MeV; this gamma flux ca...

  16. Carbon nanotube ecotoxicity in amphibians: assessment of multiwalled carbon nanotubes and comparison with double-walled carbon nanotubes.

    Science.gov (United States)

    Mouchet, Florence; Landois, Perine; Puech, Pascal; Pinelli, Eric; Flahaut, Emmanuel; Gauthier, Laury

    2010-08-01

    The potential impact of industrial multiwalled carbon nanotubes (MWNTs) was investigated under normalized laboratory conditions according to the International Standard micronucleus assay ISO 21427-1 for 12 days of half-static exposure to 0.1, 1, 10 and 50 mg/l of MWNTs in water. Three different end points were carried out for 12 days of exposure: mortality, growth inhibition and micronuclei induction in erythrocytes of the circulating blood of larvae. Raman spectroscopy analysis was used to study the presence of carbon nanotubes in the biological samples. Considering the high diversity of carbon nanotubes according to their different characteristics, MWNTs were analyzed in Xenopus larvae, comparatively to double-walled carbon nanotubes used in a previous study in similar conditions. Growth inhibition in larvae exposed to 50 mg/l of MWNTs was evidenced; however, no genetoxicity (micronucleus assay) was noticed, at any concentration. Carbon nanotube localization in the larvae leads to different possible hypothesis of mechanisms explaining toxicity in Xenopus.

  17. Multi-functional carbon nanomaterials: Tailoring morphology for multidisciplinary applications

    Energy Technology Data Exchange (ETDEWEB)

    Dervishi, Enkeleda [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-05-14

    Carbon based nanomaterials are being developed to have many new properties and applications. Graphene, is a mono-layer 2D atomic thick structure formed from hexagons of carbon atoms bound together by sp^2hybrid bonds. A carbon nanotube (CNT) can be viewed as a sheet of graphene rolled up into a cylinder, usually 1-2 nanometers in diameter and a few microns thick. A few applications of graphene and carbon nanotubes include the development of Nanoelectronics, nanocomposite materials, Hydrogen storage and Li⁺ battery, etc.

  18. Twelve year interannual and seasonal variability of stream carbon export from a boreal peatland catchment

    Science.gov (United States)

    Leach, J. A.; Larsson, A.; Wallin, M. B.; Nilsson, M. B.; Laudon, H.

    2016-07-01

    Understanding stream carbon export dynamics is needed to accurately predict how the carbon balance of peatland catchments will respond to climatic and environmental change. We used a 12 year record (2003-2014) of continuous streamflow and manual spot measurements of total organic carbon (TOC), dissolved inorganic carbon (DIC), methane (CH4), and organic carbon quality (carbon-specific ultraviolet absorbance at 254 nm per dissolved organic carbon) to assess interannual and seasonal variability in stream carbon export for a peatland catchment (70% mire and 30% forest cover) in northern Sweden. Mean annual total carbon export for the 12 year period was 12.2 gCm-2 yr-1, but individual years ranged between 6 and 18 gCm-2 yr-1. TOC, which was primarily composed of dissolved organic carbon (>99%), was the dominant form of carbon being exported, comprising 63% to 79% of total annual exports, and DIC contributed between 19% and 33%. CH4 made up less than 5% of total export. When compared to previously published annual net ecosystem exchange (NEE) for the studied peatland system, stream carbon export typically accounted for 12 to 50% of NEE for most years. However, in 2006 stream carbon export accounted for 63 to 90% (estimated uncertainty range) of NEE due to a dry summer which suppressed NEE, followed by a wet autumn that resulted in considerable stream export. Runoff exerted a primary control on stream carbon export from this catchment; however, our findings suggest that seasonal variations in biologic and hydrologic processes responsible for production and transport of carbon within the peatland were secondary influences on stream carbon export. Consideration of these seasonal dynamics is needed when predicting stream carbon export response to environmental change.

  19. Molybdosphoric Acid Mixed with Titania Used as a Catalyst to Synthesize Diphenyl Carbonate via Transesterification of Dimethyl Carbonate and Phenol

    Institute of Scientific and Technical Information of China (English)

    Tong Chen; Huajun Han; Zhiping Du; Jie Yao; Gongying Wang; Dachuan Shi; Desheng Zhang; Zhiming Chen

    2006-01-01

    The 12-molybdosphoric acid mixed with titania (MPA-TiO2) was found to be a novel and efficient catalyst for the synthesis of diphenyl carbonate (DPC) via transesterification of dimethyl carbonate (DMC) and phenol. The X-ray diffraction (XRD) and infrared (IR) techniques were employed to characterize the prepared catalysts. The effect of the weight ratio of the 12-molybdosphoric acid to titania on the transesterification was investigated. A 13.1% yield of DPC and an 11.6% yield of methyl phenyl carbonate (MPC) were obtained over MPA-TiO2 with the weight ratio of MPA to TiO2 as 5:1.

  20. 1,2-Bis(2-methoxy-6-formylphenoxyethane

    Directory of Open Access Journals (Sweden)

    Hongqi Li

    2011-02-01

    Full Text Available In the title compound [systematic name: 3,3′-dimethoxy-2,2′-(ethane-1,2-diyldioxydibenzaldehyde], C18H18O6, prepared from 1,2-dibromoethane and ortho-vanillin in the presence of sodium carbonate, the two vanillin units are linked via a CH2–CH2 bridge. The two benzene rings are inclined at a dihedral angle of 41.6 (5°.

  1. Vitamin B12 and folate depletion in cognition: A review

    OpenAIRE

    Moretti Rita; Torre Paola; Antonello Rodolfo; Cattaruzza Tatiana; Cazzato Giuseppe; Bava Antonio

    2004-01-01

    In cross-sectional studies, low levels of folate and B12 have been shown to be associated with cognitive decline and dementia Evidence for the putative role of folate, vitamin B12 in neurocognitive and other neurological functions comes from reported cases of severe vitamin deficiencies, particularly pernicious anemia, and homozygous defects in genes that encode for enzymes of one-carbon metabolism. The neurological alterations seen in these cases allow for a biological role of vitamins in ne...

  2. Strategies for Local Low-Carbon Development

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Nan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Price, Lynn [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fridley, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ohshita, Stephanie [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Khanna, Nina [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Min, Hu [Energy Foundation China, Beijing (China); Xiulian, Hu [Energy Research Inst., Beijing (China)

    2012-11-14

    Cities around the world are implementing policies and programs with the goal to reduce greenhouse gas emissions, as well as save energy, reduce costs, and protect the local, regional, and global environment. In China, low-carbon development is a key element of the 12th Five Year Plan. Pilot low-carbon development zones have been initiated in five provinces and eight cities and many other locations around China also want to pursue a low-carbon development pathway. This booklet provides information for government officials, policy makers, program designers and implementers, provincial and city planners, and others who want an overview of the key options available for low-carbon development at local level. These Strategies for Local Low-Carbon Development draw from successful experiences from around the world. Information is provided for low-carbon actions that can be taken in the sectors of (1) Industry, (2) Buildings and Appliances, (3) Electric Power, (4) Consumption and Waste Management, (5) Transportation and Urban Form, and (6) Agriculture and Forestry. A description of each policy is provided along with information on the stakeholders involved in implementation, the conditions for successful implementation, the expected energy and carbon savings, and the policy cost-effectiveness. Case studies show how each policy has been implemented somewhere around the world. While there are many low-carbon options available for local implementation, this booklet aims to provide guidance on those that have been most successful, that have the largest impact, and that are cost-effective in order to support low-carbon development efforts in Chinese cities.

  3. 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

  4. 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.

  5. 12 CFR 226.12 - Special credit card provisions.

    Science.gov (United States)

    2010-01-01

    ... both credit and electronic fund transfer aspects, refer to Regulation E, 12 CFR 205.12(a) regarding... Regulation E. For guidance on whether Regulation Z (12 CFR part 226) or Regulation E (12 CFR part 205... CFR 205.12(a) regarding issuance and liability for unauthorized use. On matters other than...

  6. Carbon-rich RR Lyr type stars

    CERN Document Server

    Wallerstein, George; Andrievsky, S M

    2009-01-01

    We have derived CNO abundances in 12 RR Lyrae stars. Four stars show [C/Fe] near 0.0 and two stars show [C/Fe] = 0.52 and 0.65. Red giant branch stars, which are known to be the predecessors of RR Lyrae stars, generally show a deficiency of carbon due to proton captures during their evolution from the main sequence up the giant branch. We suggest that the enhancement of carbon is due to production during the helium flash combined with mixing to the surface by vigorous convection induced by the flash itself.

  7. Carbon Isotope Chemistry in Molecular Clouds

    Science.gov (United States)

    Robertson, Amy N.; Willacy, Karen

    2012-01-01

    Few details of carbon isotope chemistry are known, especially the chemical processes that occur in astronomical environments like molecular clouds. Observational evidence shows that the C-12/C-13 abundance ratios vary due to the location of the C-13 atom within the molecular structure. The different abundances are a result of the diverse formation pathways that can occur. Modeling can be used to explore the production pathways of carbon molecules in an effort to understand and explain the chemical evolution of molecular clouds.

  8. Ferromagnetism in Carbon doped Zinc Oxide Systems

    OpenAIRE

    Nagare, B. J.; Chacko, Sajeev; Kanhere, D. G.

    2009-01-01

    We report spin polarized density functional calculations of ferromagnetic properties of a series of ZnO clusters and solid containing one or two substitutional carbon impurities. We analyze the eigen value spectra, spin densities and molecular orbitals, and induced magnetic moments for ZnC, Zn$_{2}$C, Zn$_{2}$OC, carbon substituted clusters Zn$_{n}$O$_{n}$ (n=3--10, 12) and ZnO solid. The results show that the doping induces magnetic moment of the $\\sim$2 $\\mu_{B}$ in all the cases. All the s...

  9. 40 CFR 600.507-12 - Running change data requirements.

    Science.gov (United States)

    2010-07-01

    ... technology vehicle in such a way that the city or highway fuel economy of the vehicle (or the energy... POLICY FUEL ECONOMY AND CARBON-RELATED EXHAUST EMISSIONS OF MOTOR VEHICLES Fuel Economy Regulations for... Passenger Automobiles)-Procedures for Determining Manufacturer's Average Fuel Economy § 600.507-12...

  10. 40 CFR 600.001-12 - General applicability.

    Science.gov (United States)

    2010-07-01

    ... Section 600.001-12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) ENERGY POLICY FUEL ECONOMY AND CARBON-RELATED EXHAUST EMISSIONS OF MOTOR VEHICLES Fuel Economy Regulations for 1977... of 2012 and later model year automobiles. (b) Fuel economy and related emissions data. Unless...

  11. Carbon dioxide sensor

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-11-15

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

  12. Anemia - B12 deficiency

    Science.gov (United States)

    ... tongue or bleeding gums If you have low vitamin B12 level for a long time, you can have nerve damage. Symptoms of nerve damage include: Confusion or change in mental status ( dementia ) in severe cases Depression Loss of balance Numbness ...

  13. 12 Merken, 13 Ongelukken

    NARCIS (Netherlands)

    Alsem, Karel Jan; Klein Koerkamp, Robbert

    2011-01-01

    Merken oefenen bewust en onbewust veel invloed op ons uit. Veel boeken beschrijven vooral succes stories van merken. Dit boek beschrijft van 12 merken de fouten die ze maakten in hun merk- en communicatiebeslissingen, zoals het op de markt brengen van merkextensies die ver af liggen van de kernwaard

  14. 12th CIFIT Approaches

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    CIFIT, standing for China International Fair for Investment and Trade, approved by the State Council of the People’s Republic of China, hold on September 8-11 every year in the city of Xiamen, China. In the year of 2008, the days for the 12th CIFIT approaches closely, a series of preparation have been on the way.

  15. 12.DIGESTIVE TRACT

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    12.2.Stomach and duodenum930685 Seroprevalence of Helicobacter pylori insome inhabitants of Beijing district.ZHANG Qiboet al.1st Teach Hosp,Beijing Med Univ,Bei-jing,100034.Beijing Med J 1993;15(4):212-214.With the use of an enzyme-linked immunosorbentassay(ELISA),we estimated 200 healthy blood

  16. TOTAL CARBON STOCK IN AGRICULTURAL SYSTEM HAVING CROP ROTATION IN TARAI REGION OF NORTHERN INDIA

    OpenAIRE

    Kavita Tariyal

    2014-01-01

    Soil organic carbon pools are important in maintaining soil productivity and influencing the CO2 loading into the atmosphere. Agricultural soils can mitigate the problem of carbon concentration increase in atmosphere if proper management practices are involved. In the present study, total carbon stock in crops and soil was analyzed for two years along with crop rotation practice to observe its impact on the carbon pool. For that two agricultural fields C12 and D7 were incorporated with differ...

  17. Carbonated fermented dairy drink - effect on quality and shelf life.

    Science.gov (United States)

    Ravindra, Menon Rekha; Rao, K Jayaraj; Nath, B Surendra; Ram, Chand

    2014-11-01

    Processing conditions were standardized for a carbonated sweetened fermented dairy beverage. The optimum level of carbonation for the beverage filled in 200 ml glass bottles was found to be at 50 psi pressure for 30 seconds. The beverage samples were stored under refrigerated conditions (7 °C) and evaluated at weekly intervals for their sensory, chemical and microbial quality. The uncarbonated control samples were found to keep well till 5 weeks of storage while the carbonated beverage was acceptable up to 12 weeks of storage. Carbonation did not significantly alter the pH of the beverage, while a marginal increase in titratable acidity was recorded for the carbonated samples. Carbonation was found to arrest the development of lipolysis and proteolysis in the beverage during storage. Microbiological investigations established the inhibition of yeast and mold growth due to dissolved CO2. PMID:26396337

  18. Chinas carbon-intensity target: climate actors and policy developments

    Energy Technology Data Exchange (ETDEWEB)

    Stensdal, Iselin

    2012-11-01

    China has become the largest GHG emitting country, and announced in 2009 its first policy objective measured in carbon emissions. The carbon-intensity target is to reduce the carbon intensity by 40-45 % by 2020 compared to 200 levels. Since then there has been further policy developments in order to attain the reduction carbon intensity and steer China towards a low-carbon development. The 12th 5-year plan (2011-2015) is strong on incentives for reducing China's carbon intensity such as energy conservation measures and the establishment of new market-based mechanisms. While the central government forms the policies, the implementation is dependent on a range of actors. In addition to the climate change bureaucracy, the positive forces and actors on GHG mitigation is presented. All in all, there are promising developments in China for the years to come.(auth)

  19. The 12C(12C,α)20Ne and 12C(12C,p)23Na reactions at the Gamow peak via the Trojan Horse Method

    Science.gov (United States)

    Tumino, A.; Spitaleri, C.; Cherubini, S.; Guardo, L.; Gulino, M.; Indelicato, I.; La Cognata, M.; Lamia, L.; Pizzone, R. G.; Puglia, S. M. R.; Rapisarda, G. G.; Romano, S.; Sergi, M. L.; Spartá, R.

    2016-05-01

    A measurement of the 12C(14N,α20Ne)2H and 12C(14N,p23Na)2Hreactions has been performed at a 14N beam energy of 30.0 MeV. The experiment aims to explore the extent to which contributing 24Mg excited states can be populated in the quasi-free reaction off the deuteron in 14N. In particular, the 24Mg excitation region explored in the measurement plays a key role in stellar carbon burning whose cross section is commonly determined by extrapolating high-energy fusion data. From preliminary results, α and proton channels are clearly identified. In particular, ground and first excited states of 20Ne and 23Na play a major role.

  20. The 12C(12C,α20Ne and 12C(12C,p23Na reactions at the Gamow peak via the Trojan Horse Method

    Directory of Open Access Journals (Sweden)

    Tumino A.

    2016-01-01

    Full Text Available A measurement of the 12C(14N,α20Ne2H and 12C(14N,p23Na2Hreactions has been performed at a 14N beam energy of 30.0 MeV. The experiment aims to explore the extent to which contributing 24Mg excited states can be populated in the quasi-free reaction off the deuteron in 14N. In particular, the 24Mg excitation region explored in the measurement plays a key role in stellar carbon burning whose cross section is commonly determined by extrapolating high-energy fusion data. From preliminary results, α and proton channels are clearly identified. In particular, ground and first excited states of 20Ne and 23Na play a major role.

  1. NON-DESTRUCTIVE SOIL CARBON ANALYZER.

    Energy Technology Data Exchange (ETDEWEB)

    Wielopolski, Lucian; Hendrey, G.; Orion, I.; Prior, S.; Rogers, H.; Runion, B.; Torbert, A.

    2004-02-01

    This report describes the feasibility, calibration, and safety considerations of a non-destructive, in situ, quantitative, volumetric soil carbon analytical method based on inelastic neutron scattering (INS). The method can quantify values as low as 0.018 gC/cc, or about 1.2% carbon by weight with high precision under the instrument's configuration and operating conditions reported here. INS is safe and easy to use, residual soil activation declines to background values in under an hour, and no radiological requirements are needed for transporting the instrument. The labor required to obtain soil-carbon data is about 10-fold less than with other methods, and the instrument offers a nearly instantaneous rate of output of carbon-content values. Furthermore, it has the potential to quantify other elements, particularly nitrogen. New instrumentation was developed in response to a research solicitation from the U.S. Department of Energy (DOE LAB 00-09 Carbon Sequestration Research Program) supporting the Terrestrial Carbon Processes (TCP) program of the Office of Science, Biological and Environmental Research (BER). The solicitation called for developing and demonstrating novel techniques for quantitatively measuring changes in soil carbon. The report includes raw data and analyses of a set of proof-of-concept, double-blind studies to evaluate the INS approach in the first phase of developing the instrument. Managing soils so that they sequester massive amounts of carbon was suggested as a means to mitigate the atmospheric buildup of anthropogenic CO{sub 2}. Quantifying changes in the soils' carbon stocks will be essential to evaluating such schemes and documenting their performance. Current methods for quantifying carbon in soil by excavation and core sampling are invasive, slow, labor-intensive and locally destroy the system being observed. Newly emerging technologies, such as Laser Induced Breakdown Spectroscopy and Near-Infrared Spectroscopy, offer soil-carbon

  2. ER-12-1 completion report

    International Nuclear Information System (INIS)

    The objective of drillhole ER-12-1 was to determine the hydrogeology of paleozoic carbonate rocks and of the Eleana Formation, a regional aquitard, in an area potentially downgradient from underground nuclear testing conducted in nearby Rainier Mesa. This objective was addressed through the drilling of well ER-12-1 at N886,640.26 E640,538.85 Nevada Central Coordinates. Drilling of the 1094 m (3588 ft) well began on July 19, 1991 and was completed on October 17, 1991. Drilling problems included hole deviation and hole instability that prevented the timely completion of this borehole. Drilling methods used include rotary tri-cone and rotary hammer drilling with conventional and reverse circulation using air/water, air/foam (Davis mix), and bentonite mud. Geologic cuttings and geophysical logs were obtained from the well. The rocks penetrated by the ER-12-1 drillhole are a complex assemblage of Silurian, Devonian, and Mississippian sedimentary rocks that are bounded by numerous faults that show substantial stratigraphic offset. The final 7.3 m (24 ft) of this hole penetrated an unusual intrusive rock of Cretaceous age. The geology of this borehole was substantially different from that expected, with the Tongue Wash Fault encountered at a much shallower depth, paleozoic rocks shuffled out of stratigraphic sequence, and the presence of an altered biotite-rich microporphyritic igneous rock at the bottom of the borehole. Conodont CAI analyses and rock pyrolysis analyses indicate that the carbonate rocks in ER-12-1, as well as the intervening sheets of Eleana siltstone, have been thermally overprinted following movement on the faults that separate them. The probable source of heat for this thermal disturbance is the microporphyritic intrusion encountered at the bottom of the hole, and its age establishes that the major fault activity must have occurred prior to 102.3+0.5 Ma (middle Cretaceous)

  3. ER-12-1 completion report

    Energy Technology Data Exchange (ETDEWEB)

    Russell, C.E.; Gillespie, D.; Cole, J.C.; Drellack, S.L. [and others

    1996-12-01

    The objective of drillhole ER-12-1 was to determine the hydrogeology of paleozoic carbonate rocks and of the Eleana Formation, a regional aquitard, in an area potentially downgradient from underground nuclear testing conducted in nearby Rainier Mesa. This objective was addressed through the drilling of well ER-12-1 at N886,640.26 E640,538.85 Nevada Central Coordinates. Drilling of the 1094 m (3588 ft) well began on July 19, 1991 and was completed on October 17, 1991. Drilling problems included hole deviation and hole instability that prevented the timely completion of this borehole. Drilling methods used include rotary tri-cone and rotary hammer drilling with conventional and reverse circulation using air/water, air/foam (Davis mix), and bentonite mud. Geologic cuttings and geophysical logs were obtained from the well. The rocks penetrated by the ER-12-1 drillhole are a complex assemblage of Silurian, Devonian, and Mississippian sedimentary rocks that are bounded by numerous faults that show substantial stratigraphic offset. The final 7.3 m (24 ft) of this hole penetrated an unusual intrusive rock of Cretaceous age. The geology of this borehole was substantially different from that expected, with the Tongue Wash Fault encountered at a much shallower depth, paleozoic rocks shuffled out of stratigraphic sequence, and the presence of an altered biotite-rich microporphyritic igneous rock at the bottom of the borehole. Conodont CAI analyses and rock pyrolysis analyses indicate that the carbonate rocks in ER-12-1, as well as the intervening sheets of Eleana siltstone, have been thermally overprinted following movement on the faults that separate them. The probable source of heat for this thermal disturbance is the microporphyritic intrusion encountered at the bottom of the hole, and its age establishes that the major fault activity must have occurred prior to 102.3+0.5 Ma (middle Cretaceous).

  4. 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.

  5. 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

  6. 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

  7. Biosphere model simulations of interannual variability in terrestrial 13C/12C exchange.

    NARCIS (Netherlands)

    Velde, van der I.R.; Miller, J.B.; Schaefer, K.; Masarie, K.A.; Denning, S.; White, J.W.C.; Krol, M.C.; Peters, W.; Tans, P.P.

    2013-01-01

    Previous studies suggest that a large part of the variability in the atmospheric ratio of (CO2)-C-13/(12)CO(2)originates from carbon exchange with the terrestrial biosphere rather than with the oceans. Since this variability is used to quantitatively partition the total carbon sink, we here investig

  8. 75 FR 40729 - Residues of Quaternary Ammonium Compounds, N-Alkyl (C12-14

    Science.gov (United States)

    2010-07-14

    ...) 305-5805. II. Summary of Petitioned-For Exemption In the Federal Register of November 28, 2007 (72 FR... represents the different number of hydrocarbon carbon moieties delineated by different percentages (e.g... chemicals together because variance in the length and conformation of alkyl carbon chains between 12 and...

  9. Seagrass restoration enhances "blue carbon" sequestration in coastal waters.

    Directory of Open Access Journals (Sweden)

    Jill T Greiner

    Full Text Available Seagrass meadows are highly productive habitats that provide important ecosystem services in the coastal zone, including carbon and nutrient sequestration. Organic carbon in seagrass sediment, known as "blue carbon," accumulates from both in situ production and sedimentation of particulate carbon from the water column. Using a large-scale restoration (>1700 ha in the Virginia coastal bays as a model system, we evaluated the role of seagrass, Zosteramarina, restoration in carbon storage in sediments of shallow coastal ecosystems. Sediments of replicate seagrass meadows representing different age treatments (as time since seeding: 0, 4, and 10 years, were analyzed for % carbon, % nitrogen, bulk density, organic matter content, and ²¹⁰Pb for dating at 1-cm increments to a depth of 10 cm. Sediment nutrient and organic content, and carbon accumulation rates were higher in 10-year seagrass meadows relative to 4-year and bare sediment. These differences were consistent with higher shoot density in the older meadow. Carbon accumulation rates determined for the 10-year restored seagrass meadows were 36.68 g C m⁻² yr⁻¹. Within 12 years of seeding, the restored seagrass meadows are expected to accumulate carbon at a rate that is comparable to measured ranges in natural seagrass meadows. This the first study to provide evidence of the potential of seagrass habitat restoration to enhance carbon sequestration in the coastal zone.

  10. The role of urbanization in the global carbon cycle

    Directory of Open Access Journals (Sweden)

    Galina eChurkina

    2016-01-01

    Full Text Available Urban areas account for more than 70% of CO2 emissions from burning fossil fuels. Urban expansion in tropics is responsible for 5% of the annual emissions from land use change. Here I show that the effect of urbanization on the global carbon cycle extends beyond these emissions. I quantify the contribution of urbanization to the major carbon fluxes and pools globally and identify gaps crucial for predicting the evolution of the carbon cycle in the future. Urban residents currently control ~22 (12-40 % of the land carbon uptake (112 PgC/yr and ~24 (15-39 % of the carbon emissions (117 PgC/yr from land globally. Urbanization resulted in the creation of new carbon pools on land such as buildings (~6.7 PgC and landfills (~30 PgC. Together these pools store 1.6 (±0.3 % of the total vegetation and soil carbon pools globally. The creation and maintenance of these new pools has been associated with high emissions of CO2, which are currently better understood than the processes associated with the dynamics of these pools and accompanying uptake of carbon. Predictions of the future trajectories of the global carbon cycle will require a much better understanding of how urban development affects the carbon cycle over the long term.

  11. Nanographene reinforced carbon/carbon composites

    Science.gov (United States)

    Bansal, Dhruv

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

  12. The impact of a unilateral carbon tax on carbon-intensive industries: evidence from Norway

    Energy Technology Data Exchange (ETDEWEB)

    Golombek, R.

    1996-02-01

    This publication identifies the impact of a unilateral Norwegian carbon tax on the profitability and the exit probability in 12 carbon intensive manufacturing sectors. The study uses Norwegian panel data for manufacturing firms and focuses both on a tax on burning of fossil fuels and a tax on all emissions of carbon. It is demonstrated that for most carbon intensive sectors the impact on both profits and the exit probability of a tax on burning of fossil fuel is negligible or moderate. That is, the increase in the average sectorial exit probability is always less that one percentage point when the tax is 75 USD per tonne carbon dioxide. On the other hand, for sectors where carbon emissions are due to both burning of fossil fuels and the production process, the impact of a general tax on carbon dioxide (at 75 USD) is significant. In particular, in the manufacture of ferro alloys the average exit probability may increase by more than 15 percentage points. 15 refs., 11 figs., 8 tabs.

  13. 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)

  14. 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

  15. Direct Measurement of the 4He(12C, 16Oγ Total Cross Section Near Stellar Energies

    Directory of Open Access Journals (Sweden)

    Fujita Kunihiro

    2015-01-01

    For measuring at Ecm < 1.2 MeV, a hybrid detector employing both, an ionization chamber and a silicon detector was developed to reduce the carbon backgrounds more efficiently. The oxygen ions were clearly separated from carbon background by using the energy deposit in the ionization chamber. Experiment of Ecm = 1.2 MeV was performed and the cross section was obtained.

  16. Daedalus 12 - Light pollution

    OpenAIRE

    Sánchez de Miguel, Alejandro; Ocaña, Francisco; Conde, Aitor; Ortuño, Frenando; Gómez Sánchez-Tirado, Miguel Angel; Mayo, David; Zamorano, Jaime; Izquierdo, Jaime; Raya, Ruben; Leon, Pedro

    2016-01-01

    Light pollution of Valencia from the Probe Daedalus 12. Video of the PRO-AM colaboration -between the Dep. Astrofísica y CC. de la Atmosfera of the Universidad Complutese de Madrid and Daedalus project, Astroinova Asociation. Mission of an stratospheric balloon. It was recorded with a High sensitivity camera(Watec 902H2) and a video recorder.

  17. Carbonation Behavior of Pure Cement Hydrates under Supercritical Carbon Dioxide Conditions - 12199

    International Nuclear Information System (INIS)

    Carbonation of cement-based waste forms using a supercritical carbon dioxide (SCCO2) is a developing technology for the waste immobilization of radioactive and non-radioactive wastes. However, the detail carbonation behaviors of cement matrices under the SCCO2 condition are unknown, since cement matrices forms very complex phases. In this study, in order to clarify the crystal phases, we synthesized pure cement hydrate phases as each single phases; portlandite (Ca(OH)2), ettringite (Ca6Al2(SO4)3(OH)12.26H2O), and calcium silicate hydrate (n CaO---m SiO2 ---x H2O), using suspensions containing a stoichiometric mixture of chemical regents, and performed carbonation experiments using an autoclave under supercritical condition for carbon dioxide. The XRD results revealed both the carbonate phases and co-product phases depending on the initial hydrate phases; gypsum for Ettringite, amorphous or crystalline silica for calcium silicate hydroxide. Thermogravimetric analysis was also performed to understand carbonation behaviors quantitatively. According to the experimental results, it was found that the major reaction was formation of calcium carbonate (CaCO3) in all cases. However, the behaviors of H2O and CO2 content were quietly different: Portlandite was most reactive for carbonation under SCCO2 conditions, and the CO2 content per one molar CaO was ranged from 0.96 ∼ 0.98. In the case of Ettringite, the experiment indicates partial decomposition of ettringite phase during carbonation. Ettringite was comparatively stable even under the SCCO2 conditions. Therefore, a part of ettringite remained and formed similar phases after the ettringite carbonation. The CO2 content for ettringite showed almost constant values around 0.86 ∼ 0.87. In the case of calcium silicate hydrate, the carbonation behavior was significantly influenced by the condition of SCCO2. The CO2 content for the calcium silicate hydrate had values that ranged from 0.51 ∼ 1.01. The co-products of the

  18. The first direct measurement of 12C(12C,n)23Mg at stellar energies

    CERN Document Server

    Bucher, B; Fang, X; Heger, A; Almaraz-Calderon, S; Alongi, A; Ayangeakaa, A D; Beard, M; Best, A; Browne, J; Cahillane, C; Couder, M; deBoer, R J; Kontos, A; Lamm, L; Li, Y J; Long, A; Lu, W; Lyons, S; Notani, M; Patel, D; Paul, N; Pignatari, M; Roberts, A; Robertson, D; Smith, K; Stech, E; Talwar, R; Tan, W P; Wiescher, M; Woosley, S E

    2015-01-01

    Neutrons produced by the carbon fusion reaction 12C(12C,n)23Mg play an important role in stellar nucleosynthesis. However, past studies have shown large discrepancies between experimental data and theory, leading to an uncertain cross section extrapolation at astrophysical energies. We present the first direct measurement that extends deep into the astrophysical energy range along with a new and improved extrapolation technique based on experimental data from the mirror reaction 12C(12C,p)23Na. The new reaction rate has been determined with a well-defined uncertainty that exceeds the precision required by astrophysics models. Using our constrained rate, we find that 12C(12C,n)23Mg is crucial to the production of Na and Al in Pop-III Pair Instability Supernovae. It also plays a non-negligible role in the production of weak s-process elements as well as in the production of the important galactic gamma-ray emitter 60Fe.

  19. Functions required for vitamin B12-dependent ethanolamine utilization in Salmonella typhimurium.

    OpenAIRE

    Roof, D M; Roth, J R

    1989-01-01

    When B12 is available, Salmonella typhimurium can degrade ethanolamine to provide a source of carbon and nitrogen. B12 is essential since it is a cofactor for ethanolamine ammonia-lyase, the first enzyme in ethanolamine breakdown. S. typhimurium makes B12 only under anaerobic conditions; in the presence of oxygen, exogenous B12 must be provided to permit ethanolamine utilization. Genes required for ethanolamine utilization are encoded in the eut operon. For complementation testing, an F' plas...

  20. Soil Carbon Changes Following Afforestation with Olga Bay Larch (Larix olgensis Henry) in Northeastern China

    Institute of Scientific and Technical Information of China (English)

    Chun-Mei Wang; Hua Ouyang; Bin Shao; Yu-Qiang Tian; Jing-Gang Zhao; Huai-Yan Xu

    2006-01-01

    After converting cropland to forest, carbon is sequestered in the aggrading biomass of the new forests,but the question remains, to what extent will the former arable soil contribute as a sink for CO2? Quantifying changes in soil carbon is an important consideration in the large-scale conversion of cropland to forest.Extensive field studies were undertaken to identify a number of suitable sites for comparison of soil properties under pasture and forest. The present paper describes results from a study of the effects of first rotation larch on soil carbon in seven stands in an afforestation chronosequence compared with adjacent Korean pine, pasture, and cropland. An adjacent 250-year-old natural forest was included to give information on the possible long-term changes in soil carbon in northeast China in 2004. Soil carbon initially decreased during the first 12 yr before a gradual recovery and accumulation of soil carbon occurred. The initial (0-12 yr) decrease in soil carbon was an average 1.2% per year among case studies, whereas the increase in soil carbon (12-33 yr) was 1.90% per year. Together with the carbon sequestration of forest floors, this led to total soil carbon stores of approximately 101.83 Mg/hm2 over the 33-year chronosequence.Within the relatively short time span, carbon sequestration occurred mainly in tree biomass, whereas soil carbon stores were clearly higher in the 250-year-old plantation (184 Mg/hm2). The ongoing redistribution of mineral soil carbon in the young stands and the higher soil carbon contents in the 250-year-old afforested stand suggest that nutrient-rich afforestation soils may become greater sinks for carbon (C) in the long term.

  1. Double layer capacitance of carbon foam electrodes

    Science.gov (United States)

    Delnick, F. M.; Ingersoll, D.; Firsich, D.

    We have evaluated a wide variety of microcellular carbon foams prepared by the controlled pyrolysis and carbonization of several polymers including: polyacrylonitrile (PAN), polymethacrylonitrile (PMAN), resorcinol/formaldehyde (RF), divinylbenzene/methacrylonitrile (DVB), phenolics (furfuryl/alcohol), and cellulose polymers such as Rayon. The porosity may be established by several processes including: gelation (1-5), phase separation (1-3,5-8), emulsion (1,9,10), aerogel/xerogel formation (1,11,12,13), replication (14), and activation. In this report we present the complex impedance analysis and double layer charging characteristics of electrodes prepared from one of these materials for double layer capacitor applications, namely activated cellulose derived microcellular carbon foam.

  2. Purification process for vertically aligned carbon nanofibers

    Science.gov (United States)

    Nguyen, Cattien V.; Delziet, Lance; Matthews, Kristopher; Chen, Bin; Meyyappan, M.

    2003-01-01

    Individual, free-standing, vertically aligned multiwall carbon nanotubes or nanofibers are ideal for sensor and electrode applications. Our plasma-enhanced chemical vapor deposition techniques for producing free-standing and vertically aligned carbon nanofibers use catalyst particles at the tip of the fiber. Here we present a simple purification process for the removal of iron catalyst particles at the tip of vertically aligned carbon nanofibers derived by plasma-enhanced chemical vapor deposition. The first step involves thermal oxidation in air, at temperatures of 200-400 degrees C, resulting in the physical swelling of the iron particles from the formation of iron oxide. Subsequently, the complete removal of the iron oxide particles is achieved with diluted acid (12% HCl). The purification process appears to be very efficient at removing all of the iron catalyst particles. Electron microscopy images and Raman spectroscopy data indicate that the purification process does not damage the graphitic structure of the nanotubes.

  3. 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

  4. Forest carbon trading : legal, policy, ecological and aboriginal issues

    International Nuclear Information System (INIS)

    was presented, including costs for sequestering carbon range and counting forest product sinks. Conservation and management costs as well as tree planting costs were also presented. The overall projected carbon price was estimated at $4.00 to $12.00 per tonne by 2008. tabs., figs

  5. 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.

  6. 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 ...

  7. 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

  8. 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...

  9. 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.

  10. 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

  11. 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

  12. 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...

  13. 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.)…

  14. 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 ...

  15. 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,

  16. Carbon isotopic composition of individual Precambrian microfossils

    Science.gov (United States)

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

    2000-01-01

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

  17. Carbon isotopic composition of individual Precambrian microfossils.

    Science.gov (United States)

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

    2000-08-01

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

  18. Stable carbon isotope analysis of heavy oils

    Energy Technology Data Exchange (ETDEWEB)

    Fixari, B.; Le Perchec, P.; Bigois, M.; Casabianca, H.; Jame, P. [CNRS, Vernaison (France). Lab. des Materiaux Organiques

    1994-03-01

    Stable carbon isotope analysis of various heavy oils and some thermo-catalytically converted products was performed with a thermal analyser coupled with an isotopic ratio mass spectrometer. The temperature-programmed oxidative pyroanalysis technique subdivides the classical {sup 13}C/{sup 12}C ratio, affording new insights into the structural composition of heavy oils such as the contribution of naphthenoaromatics, and appears to be of interest for following their thermal refining. 24 refs., 11 figs., 2 tabs.

  19. Bio-inspired Hybrid Carbon Nanotube Muscles

    OpenAIRE

    Tae Hyeob Kim; Cheong Hoon Kwon; Changsun Lee; Jieun An; Tam Thi Thanh Phuong; Sun Hwa Park; Lima, Márcio D.; Baughman, Ray H.; Tong Mook Kang; Seon Jeong Kim

    2016-01-01

    There has been continuous progress in the development for biomedical engineering systems of hybrid muscle generated by combining skeletal muscle and artificial structure. The main factor affecting the actuation performance of hybrid muscle relies on the compatibility between living cells and their muscle scaffolds during cell culture. Here, we developed a hybrid muscle powered by C2C12 skeletal muscle cells based on the functionalized multi-walled carbon nanotubes (MWCNT) sheets coated with p...

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  2. Carbonation-Related Microstructural Changesin Long-Term Durability Concrete

    Directory of Open Access Journals (Sweden)

    Cláudio A. Rigo da Silva

    2002-09-01

    Full Text Available This paper discusses the effects of carbonation on the microstructure of Portland cement concrete for long-term durability applications. A class C40 concrete (characteristic compression strength between 40 MPa and 44 MPa on the 28th day, according to Brazilian standard NBR 8953 was chosen for the experimental study of the carbonation effects, from which test samples were molded for accelerated test under a 100%-CO2 atmosphere after physical and mechanical characterization. It was observed that carbonation provoked a reduction of 5% to 12% of the concrete open porosity accessible to water. Flexural strength values obtained after the carbonation tests revealed a decrease of 12% and 25% in relation to the values obtained before tests on the 28th and 91st days, respectively.

  3. Major carbon industries in India

    Energy Technology Data Exchange (ETDEWEB)

    Jain, P.K.

    1982-01-01

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

  4. Synthesis of hydrated lutetium carbonate

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-09-01

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

  5. Evaluating Soil Carbon Sequestration in Central Iowa

    Science.gov (United States)

    Doraiswamy, P. C.; Hunt, E. R.; McCarty, G. W.; Daughtry, C. S.; Izaurralde, C.

    2005-12-01

    The potential for reducing atmospheric carbon dioxide (CO2) concentration through landuse and management of agricultural systems is of great interest worldwide. Agricultural soils can be a source of CO2 when not properly managed but can also be a sink for sequestering CO2 through proper soil and crop management. The EPIC-CENTURY biogeochemical model was used to simulate the baseline level of soil carbon from soil survey data and project changes in soil organic carbon (SOC) under different tillage and crop management practices for corn and soybean crops. The study was conducted in central Iowa (50 km x 100 km) to simulate changes in soil carbon over the next 50 years. The simulations were conducted in two phases; initially a 25-year period (1971-1995) was simulated using conventional tillage practices since there was a transition in new management after 1995. In the second 25-year period (1996-2020), four different modeling scenarios were applied namely; conventional tillage, mulch tillage, no-tillage and no-tillage with a rye cover crop over the winter. The model simulation results showed potential gains in soil carbon in the top layers of the soil for conservation tillage. The simulations were made at a spatial resolution of 1.6 km x 1.6 km and mapped for the study area. There was a mean reduction in soil organic carbon of 0.095 T/ha per year over the 25-year period starting with 1996 for the conventional tillage practice. However, for management practices of mulch tillage, no tillage and no tillage with cover crop there was an increase in soil organic carbon of 0.12, 0.202 and 0.263 T/ha respectively over the same 25-year period. These results are in general similar to studies conducted in this region.

  6. Vitamin B12 for cognition

    OpenAIRE

    Malouf, RM; Areosa Sastre, A

    2003-01-01

    Background An association between neuropsychiatric disorders and vitamin B12 deficiency has been recognized since 1849 when pernicious anaemia was first described. It has been suggested that deficiency of vitamin B12 might contribute to age-associated cognitive impairment. Low serum vitamin B12 concentrations are found in more than 10% of older people. A high prevalence of low serum vitamin B12 levels, and other indicators of vitamin B12 deficiency have been reported among people with Alzh...

  7. Carbon Isotope and Isotopomer Fractionation in Cold Dense Cloud Cores

    CERN Document Server

    Furuya, Kenji; Sakai, Nami; Yamamoto, Satoshi

    2011-01-01

    We construct the gas-grain chemical network model which includes carbon isotopes (12C and 13C) with an emphasis on isotopomer-exchange reactions. Temporal variations of molecular abundances, the carbon isotope ratios (12CX/13CX) and the isotopomer ratios (12C13CX/13C12CX) of CCH and CCS in cold dense cloud cores are investigated by numerical calculations. We confirm that the isotope ratios of molecules, both in the gas phase and grain surfaces, are significantly different depending on whether the molecule is formed from the carbon atom (ion) or the CO molecule. Molecules formed from carbon atoms have the CX/13CX ratios greater than the elemental abundance ratio of [12C/13C]. On the other hand, molecules formed from CO molecules have the CX/13CX ratios smaller than the [12C/13C] ratio. We reproduce the observed C13CH/13CCH ratio in TMC-1, if the isotopomer exchange reaction, 13CCH + H C13CH + H + 8.1 K, proceeds with the forward rate coefficient kf > 10^-11 cm3 s-1. However, the C13CS/13CCS ratio is lower tha...

  8. Recent results from the carbon fusion project at Notre Dame

    Science.gov (United States)

    Bucher, Brian; Notani, Masahiro; Alongi, Adam; Browne, Justin; Cahillane, Craig; Dahlstrom, Erin; Davies, Paul; Fang, Xiao; Lamm, Larry; Ma, Chi; Moncion, Alexander; Tan, Wanpeng; Tang, Xiao-Dong; Thomas, Spencer

    2012-11-01

    The carbon fusion project at Notre Dame is aimed towards measuring the 12C+12C fusion cross section and its decay branches relevant to astrophysics down to the lowest possible energies. To complement this approach, we are also exploring new techniques for providing more reliable extrapolations of the cross sections in the energy ranges where experimental data are unavailable. In this paper, we report two recent results: 1) an upper limit for the 12C+12C fusion cross section, and 2) a new measurement of 12C(12C,n) along with an improved extrapolation technique based on the mirror reaction channel, 12C(12C,p). The outlook for astrophysical heavy-ion fusion studies at Notre Dame is also discussed.

  9. Recent results from the carbon fusion project at Notre Dame

    Energy Technology Data Exchange (ETDEWEB)

    Bucher, Brian; Notani, Masahiro; Alongi, Adam; Browne, Justin; Cahillane, Craig; Dahlstrom, Erin; Davies, Paul; Fang Xiao; Lamm, Larry; Ma Chi; Moncion, Alexander; Tan Wanpeng; Tang Xiaodong; Thomas, Spencer [Institute for Structure and Nuclear Astrophysics, Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, IN 46556-5670 (United States)

    2012-11-12

    The carbon fusion project at Notre Dame is aimed towards measuring the {sup 12}C+{sup 12}C fusion cross section and its decay branches relevant to astrophysics down to the lowest possible energies. To complement this approach, we are also exploring new techniques for providing more reliable extrapolations of the cross sections in the energy ranges where experimental data are unavailable. In this paper, we report two recent results: 1) an upper limit for the {sup 12}C+{sup 12}C fusion cross section, and 2) a new measurement of {sup 12}C({sup 12}C,n) along with an improved extrapolation technique based on the mirror reaction channel, {sup 12}C({sup 12}C,p). The outlook for astrophysical heavy-ion fusion studies at Notre Dame is also discussed.

  10. Recent results from the carbon fusion project at Notre Dame

    International Nuclear Information System (INIS)

    The carbon fusion project at Notre Dame is aimed towards measuring the 12C+12C fusion cross section and its decay branches relevant to astrophysics down to the lowest possible energies. To complement this approach, we are also exploring new techniques for providing more reliable extrapolations of the cross sections in the energy ranges where experimental data are unavailable. In this paper, we report two recent results: 1) an upper limit for the 12C+12C fusion cross section, and 2) a new measurement of 12C(12C,n) along with an improved extrapolation technique based on the mirror reaction channel, 12C(12C,p). The outlook for astrophysical heavy-ion fusion studies at Notre Dame is also discussed.

  11. Towards Green Cyclic Carbonate Synthesis : Heterogeneous and Homogeneous Catalyst Development

    OpenAIRE

    Stewart, J A

    2015-01-01

    This PhD research serves to implement both known and novel catalytic systems for the purpose of cyclic carbonate synthesis from biomass-derived substrates. Such products have been earmarked as potential monomers for non-isocyanate polyurethanes (NIPUs), amongst other uses. Particular attention has been placed on operating under the guidance of the 12 principles of Green Chemistry as posited by Anastas et al. Following an in depth literature discussion of catalytic cyclic carbonate synthesis i...

  12. Microwave absorbing properties of activated carbon fibre polymer composites

    Indian Academy of Sciences (India)

    Tianchun Zou; Naiqin Zhao; Chunsheng Shi; Jiajun Li

    2011-02-01

    Microwave absorption of composites containing activated carbon fibres (ACFs) was investigated. The results show that the absorptivity greatly depends on increasing ACF content in the absorbing layer, first increasing and then decreasing. When the content is 0.76 wt.%, the bandwidth below −10dB is 12.2 GHz. Comparing the absorption characteristics of the ACF composite with one containing unactivated fibres, it is found that carbon fibre activation increases the absorption of the composite.

  13. 76 FR 66893 - Certain Circular Welded Carbon Steel Pipes and Tubes From India, Thailand, and Turkey; Final...

    Science.gov (United States)

    2011-10-28

    ..., 75 FR 69626, 69627 (November 15, 2010). Thailand--Welded Carbon Steel Pipe and Tube (A-549-502) The.... See Scope Rulings, 58 FR 27542, (May 10, 1993). Turkey--Welded Carbon Steel Pipe and Tube (A-489-501... Tubes from India, 51 FR 17384 (May 12, 1986); Antidumping Duty Order; Circular Welded Carbon Steel...

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from the FRANKLIN in the Indian Ocean from 2000-09-26 to 2000-11-12 (NODC Accession 0108074)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0108074 includes chemical, discrete sample, physical and profile data collected from FRANKLIN in the Indian Ocean from 2000-09-26 to 2000-11-12 and...

  19. 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 S. A. AGULHAS in the South Atlantic Ocean from 1997-12-04 to 1998-02-06 (NODC Accession 0113247)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113247 includes chemical, discrete sample, physical and profile data collected from S. A. AGULHAS in the South Atlantic Ocean from 1997-12-04 to...

  20. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Coulometer for DIC measurement and other instruments from the MIRAI in the North Pacific Ocean from 1998-10-30 to 1998-12-15 (NODC Accession 0112251)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112251 includes chemical, discrete sample, physical and profile data collected from MIRAI in the North Pacific Ocean from 1998-10-30 to 1998-12-15...

  1. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Coulometer for DIC measurement and other instruments from the MIRAI in the North Pacific Ocean from 1997-11-11 to 1997-12-04 (NODC Accession 0112250)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112250 includes chemical, discrete sample, physical and profile data collected from MIRAI in the North Pacific Ocean from 1997-11-11 to 1997-12-04...

  2. 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 MIRAI in the Indian Ocean and Mozambique Channel from 2003-12-09 to 2004-01-24 (NODC Accession 0108101)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0108101 includes discrete sample and profile data collected from MIRAI in the Indian Ocean and Mozambique Channel from 2003-12-09 to 2004-01-24....

  3. Dissolved inorganic carbon, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Coulometer for DIC measurement and other instruments from the POLARSTERN in the South Atlantic Ocean from 1992-12-03 to 1993-01-22 (NODC Accession 0116565)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0116565 includes chemical, discrete sample, physical and profile data collected from POLARSTERN in the South Atlantic Ocean from 1992-12-03 to...

  4. Dissolved inorganic carbon, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the HUDSON in the North Atlantic Ocean from 1993-11-05 to 1993-12-16 (NODC Accession 0113553)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113553 includes chemical, discrete sample, physical and profile data collected from HUDSON in the North Atlantic Ocean from 1993-11-05 to 1993-12-16...

  5. 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 1997-12-02 to 1998-01-03 (NODC Accession 0116136)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0116136 includes chemical, discrete sample, physical and profile data collected from ROGER REVELLE in the South Pacific Ocean from 1997-12-02 to...

  6. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from the METEOR in the North Atlantic Ocean from 2006-07-12 to 2006-08-06 (NODC Accession 0109917)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0109917 includes chemical, discrete sample, physical and profile data collected from METEOR in the North Atlantic Ocean from 2006-07-12 to 2006-08-06...

  7. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from HUDSON in the Davis Strait, Labrador Sea and North Atlantic Ocean from 1996-05-12 to 1996-06-01 (NODC Accession 0115010)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0115010 includes discrete sample and profile data collected from HUDSON in the Davis Strait, Labrador Sea and North Atlantic Ocean from 1996-05-12 to...

  8. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from the MARION DUFRESNE in the Indian Ocean from 2009-12-19 to 2010-01-24 (NODC Accession 0109906)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0109906 includes chemical, discrete sample, physical and profile data collected from MARION DUFRESNE in the Indian Ocean from 2009-12-19 to...

  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...... 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 abundances and isotope ratios in 70 bright M giants

    International Nuclear Information System (INIS)

    Approximate carbon abundances and 12C/13C isotope ratios are obtained for 70 M giant stars from intermediate-resolution spectrophotometry of the CO bands near 2.3 μm. A low mean carbon abundance ([C/H]=-0.64±0.29) is obtained, suggesting that standard mixing is insufficient to explain atmospheric abundances in M giants. HR 8795 appears to be exceptionally carbon deficient, and is worthy of further study as a possible weak G-band star descendant. (author)

  11. Carbon abundances and isotope ratios in 70 bright M giants

    Energy Technology Data Exchange (ETDEWEB)

    Lazaro, C. (Inst. de Astrofisica de Canarias, Tenerife (Spain)); Lynas-Gray, A.E. (University Coll., London (UK). Dept. of Physics and Astronomy); Clegg, R.E.S. (Royal Greenwich Observatory, Cambridge (UK)); Mountain, C.M.; Zadrozny, A. (Imperial Coll. of Science and Technology, London (UK))

    1991-03-01

    Approximate carbon abundances and {sup 12}C/{sup 13}C isotope ratios are obtained for 70 M giant stars from intermediate-resolution spectrophotometry of the CO bands near 2.3 {mu}m. A low mean carbon abundance ((C/H)=-0.64+-0.29) is obtained, suggesting that standard mixing is insufficient to explain atmospheric abundances in M giants. HR 8795 appears to be exceptionally carbon deficient, and is worthy of further study as a possible weak G-band star descendant. (author).

  12. 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...

  13. 12 CFR 563g.12 - Securities sale report.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Securities sale report. 563g.12 Section 563g.12 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY SECURITIES OFFERINGS § 563g.12 Securities sale report. (a) Within 30 days after the first sale of the securities, every six months after such 30 day period and not later...

  14. A global predictive model of carbon in mangrove soils

    Science.gov (United States)

    Jardine, Sunny L.; Siikamäki, Juha V.

    2014-10-01

    Mangroves are among the most threatened and rapidly vanishing natural environments worldwide. They provide a wide range of ecosystem services and have recently become known for their exceptional capacity to store carbon. Research shows that mangrove conservation may be a low-cost means of reducing CO2 emissions. Accordingly, there is growing interest in developing market mechanisms to credit mangrove conservation projects for associated CO2 emissions reductions. These efforts depend on robust and readily applicable, but currently unavailable, localized estimates of soil carbon. Here, we use over 900 soil carbon measurements, collected in 28 countries by 61 independent studies, to develop a global predictive model for mangrove soil carbon. Using climatological and locational data as predictors, we explore several predictive modeling alternatives, including machine-learning methods. With our predictive model, we construct a global dataset of estimated soil carbon concentrations and stocks on a high-resolution grid (5 arc min). We estimate that the global mangrove soil carbon stock is 5.00 ± 0.94 Pg C (assuming a 1 meter soil depth) and find this stock is highly variable over space. The amount of carbon per hectare in the world’s most carbon-rich mangroves (approximately 703 ± 38 Mg C ha-1) is roughly a 2.6 ± 0.14 times the amount of carbon per hectare in the world’s most carbon-poor mangroves (approximately 272 ± 49 Mg C ha-1). Considerable within country variation in mangrove soil carbon also exists. In Indonesia, the country with the largest mangrove soil carbon stock, we estimate that the most carbon-rich mangroves contain 1.5 ± 0.12 times as much carbon per hectare as the most carbon-poor mangroves. Our results can aid in evaluating benefits from mangrove conservation and designing mangrove conservation policy. Additionally, the results can be used to project changes in mangrove soil carbon stocks based on changing climatological predictors, e.g. to

  15. A global predictive model of carbon in mangrove soils

    International Nuclear Information System (INIS)

    Mangroves are among the most threatened and rapidly vanishing natural environments worldwide. They provide a wide range of ecosystem services and have recently become known for their exceptional capacity to store carbon. Research shows that mangrove conservation may be a low-cost means of reducing CO2 emissions. Accordingly, there is growing interest in developing market mechanisms to credit mangrove conservation projects for associated CO2 emissions reductions. These efforts depend on robust and readily applicable, but currently unavailable, localized estimates of soil carbon. Here, we use over 900 soil carbon measurements, collected in 28 countries by 61 independent studies, to develop a global predictive model for mangrove soil carbon. Using climatological and locational data as predictors, we explore several predictive modeling alternatives, including machine-learning methods. With our predictive model, we construct a global dataset of estimated soil carbon concentrations and stocks on a high-resolution grid (5 arc min). We estimate that the global mangrove soil carbon stock is 5.00 ± 0.94 Pg C (assuming a 1 meter soil depth) and find this stock is highly variable over space. The amount of carbon per hectare in the world’s most carbon-rich mangroves (approximately 703 ± 38 Mg C ha−1) is roughly a 2.6 ± 0.14 times the amount of carbon per hectare in the world’s most carbon-poor mangroves (approximately 272 ± 49 Mg C ha−1). Considerable within country variation in mangrove soil carbon also exists. In Indonesia, the country with the largest mangrove soil carbon stock, we estimate that the most carbon-rich mangroves contain 1.5 ± 0.12 times as much carbon per hectare as the most carbon-poor mangroves. Our results can aid in evaluating benefits from mangrove conservation and designing mangrove conservation policy. Additionally, the results can be used to project changes in mangrove soil carbon stocks based on changing climatological predictors

  16. Modeling the carbon isotope composition of bivalve shells (Invited)

    Science.gov (United States)

    Romanek, C.

    2010-12-01

    The stable carbon isotope composition of bivalve shells is a valuable archive of paleobiological and paleoenvironmental information. Previous work has shown that the carbon isotope composition of the shell is related to the carbon isotope composition of dissolved inorganic carbon (DIC) in the ambient water in which a bivalve lives, as well as metabolic carbon derived from bivalve respiration. The contribution of metabolic carbon varies among organisms, but it is generally thought to be relatively low (e.g., organism and high (>90%) in the shells from terrestrial organisms. Because metabolic carbon contains significantly more C-12 than DIC, negative excursions from the expected environmental (DIC) signal are interpreted to reflect an increased contribution of metabolic carbon in the shell. This observation contrasts sharply with modeled carbon isotope compositions for shell layers deposited from the inner extrapallial fluid (EPF). Previous studies have shown that growth lines within the inner shell layer of bivalves are produced during periods of anaerobiosis when acidic metabolic byproducts (e.g., succinic acid) are neutralized (or buffered) by shell dissolution. This requires the pH of EPF to decrease below ambient levels (~7.5) until a state of undersaturation is achieved that promotes shell dissolution. This condition may occur when aquatic bivalves are subjected to external stressors originating from ecological (predation) or environmental (exposure to atm; low dissolved oxygen; contaminant release) pressures; normal physiological processes will restore the pH of EPF when the pressure is removed. As a consequence of this process, a temporal window should also exist in EPF at relatively low pH where shell carbonate is deposited at a reduced saturation state and precipitation rate. For example, EPF chemistry should remain slightly supersaturated with respect to aragonite given a drop of one pH unit (6.5), but under closed conditions, equilibrium carbon isotope

  17. 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.

  18. 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).

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

    Science.gov (United States)

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

    2013-02-01

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

  20. 12 CFR 621.12 - Applicability and general instructions.

    Science.gov (United States)

    2010-01-01

    ... require. The reports shall be prepared on the accrual basis of accounting and shall fairly represent the... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Applicability and general instructions. 621.12 Section 621.12 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM ACCOUNTING AND...

  1. 12 CFR 1261.12 - Reporting requirements for Bank directors.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Reporting requirements for Bank directors. 1261.12 Section 1261.12 Banks and Banking FEDERAL HOUSING FINANCE AGENCY FEDERAL HOME LOAN BANKS FEDERAL HOME LOAN BANK DIRECTORS Federal Home Loan Bank Boards of Directors: Eligibility and Elections §...

  2. 12 CFR 907.12 - Finance Board procedures.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Finance Board procedures. 907.12 Section 907.12 Banks and Banking FEDERAL HOUSING FINANCE BOARD FEDERAL HOUSING FINANCE BOARD ORGANIZATION AND... Finance Board procedures. (a) Notice of Receipt of Petition or Request to Intervene. No later than...

  3. 12 CFR 1710.12 - Committees of board of directors.

    Science.gov (United States)

    2010-01-01

    ... board of directors of an Enterprise shall meet with sufficient frequency to carry out its obligations... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Committees of board of directors. 1710.12... § 1710.12 Committees of board of directors. (a) General. The board of directors may rely, in...

  4. 12 CFR 925.12 - Character of management requirement.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Character of management requirement. 925.12... ASSOCIATES MEMBERS OF THE BANKS Eligibility Requirements § 925.12 Character of management requirement. An applicant shall be deemed to be in compliance with the character of management requirement of section...

  5. 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.

  6. 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.)

  7. Sodium carbonate poisoning

    Science.gov (United States)

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

  8. 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, ...

  9. 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 ...

  10. 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.

  11. 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.

  12. 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 ...

  13. 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.

  14. 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...

  15. 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.

  16. Carbon partitioning in photosynthesis.

    Science.gov (United States)

    Melis, Anastasios

    2013-06-01

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

  17. Designing of epoxy composites reinforced with carbon nanotubes grown carbon fiber fabric for improved electromagnetic interference shielding

    OpenAIRE

    Singh, B. P.; Veena Choudhary; Parveen Saini; Mathur, R.B.

    2012-01-01

    In this letter, we report preparation of strongly anchored multiwall carbon nanotubes (MWCNTs) carbon fiber (CF) fabric preforms. These preforms were reinforced in epoxy resin to make multi scale composites for microwave absorption in the X-band (8.2-12.4GHz). The incorporation of MWCNTs on the carbon fabric produced a significant enhancement in the electromagnetic interference shielding effectiveness (EMI-SE) from −29.4 dB for CF/epoxy-composite to −51.1 dB for CF-MWCNT/epoxy multiscale comp...

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

    Science.gov (United States)

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

    2012-08-01

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

  19. 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

  20. Carbon Isotopic Fractionation During Formation of Macromolecular Organic Grain Coatings via FTT Reactions

    Science.gov (United States)

    Nuth, J. A.; Johnson, N. M.; Elsila-Cook, J.; Kopstein, M.

    2011-01-01

    Observations of carbon isotopic fractionation of various organic compounds found in meteorites may provide useful diagnostic information concerning the environments and mechanisms that were responsible for their formation. Unfortunately, carbon has only two stable isotopes, making interpretation of such observations quite problematic. Chemical reactions can increase or decrease the C-13/C-12 ratio by various amounts, but the final ratio will depend on the total reaction pathway followed from the source carbon to the final product, a path not readily discernable after 4.5 billion years. In 1970 Libby showed that the C-13/C-12 ratios of terrestrial and meteoritic carbon were similar by comparing carbon from the Murchison meteorite to that of terrestrial sediments. More recent studies have shown that the C-13/C-12 ratio of the Earth and meteorites may be considerably enriched in C-13 compared to the ratio observed in the solar wind [2], possibly suggesting that carbon produced via ion-molecule reactions in cold dark clouds could be an important source of terrestrial and meteoritic carbon. However, meteoritic carbon has been subjected to parent body processing that could have resulted in significant changes to the C-13/C-12 ratio originally present while significant variation has been observed in the C-13/C-12 ratio of the same molecule extracted from different terrestrial sources. Again we must conclude that understanding the ratio found in meteorites may be difficult.

  1. 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)

  2. Selective Oxidation of Soft Grade Carbon

    Directory of Open Access Journals (Sweden)

    Zecevic, N.

    2007-12-01

    into granules, and the most famous are the wet, semi-wet, and the dry process. In the oil-furnace process, the wet process of granulation is the most acceptable, in which the "fluffy" carbon black is mixed with water in an approximate ratio. After granulation, the carbon black is dried in a rotary drum at temperatures ranging between 180 to 210 °C. The period of drying is various, and depends on the production capacity and moisture fraction.The described laboratory procedure improvised successfully industrial conditions of granulating soft grade carbon black, and it is applicable to the conventional industrial method of producing soft grade oil-furnace carbon black at the Kutina plant, which is shown in Tables 1-7, and Figures 1-2.

  3. [1,2]-Wittig Rearrangement of THP Acetal Compounds: Facile Synthesis of Aromatic Tertiary Alcohols

    Directory of Open Access Journals (Sweden)

    Feng-Lei Gu

    2011-01-01

    Full Text Available Several sec-aromatic THP acetal compounds have been found to be suitable substrates for the [1,2]-Wittig rearrangement in the absence of an external electrophile, which resulted in the generation of new carbon-carbon bond and the facile synthesis of aromatic tertiary alcohols. More interestingly, an unexpected effect of chlorotrimethylsilane on this [1,2]-Wittig rearrangement of sec-aromatic THP acetal compounds was found, in which two different products involving oxidative procedure were obtained due to the competitive [1,4]-Sigmatropic rearrangement versus [1,2]-Wittig rearrangement

  4. 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.

  5. 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

  6. 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.

  7. Method for synthesizing carbon nanotubes

    Science.gov (United States)

    Fan, Hongyou

    2012-09-04

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

  8. Carbon isotopes as indicators of peatland growth?

    Science.gov (United States)

    Alewell, Christine; Krüger, Jan Paul; von Sengbusch, Pascal; Szidat, Sönke; Leifeld, Jens

    2016-04-01

    ., and Alewell, C. 2014. Degradation changes stable carbon isotope depth profiles in palsa peatlands. Biogeosciences, 11, 3369-3380. Krüger, J. P., Leifeld, J., Glatzel, S., Szidat, S., and Alewell, C. 2015: Biogeochemical indicators of peatland degradation - a case study of a temperate bog in northern Germany, Biogeosciences, 12, 2861-2871. Krüger, J. P., Alewell, C., Minkkinen, K., Szidat, S., and Leifeld, J. 2016: Calculating carbon changes in peat soils drained for forestry with four different profile-based methods (under review).

  9. Aspects of carbon dioxide utilization

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-06-30

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

  10. Abundances in red giant stars - Carbon and oxygen isotopes in carbon-rich molecular envelopes

    Science.gov (United States)

    Wannier, P. G.; Sahai, R.

    1987-01-01

    Millimeter-wave observations have been made of isotopically substituted CO toward the envelopes of 11 carbon-rich stars. In every case, C-13O was detected and model calculations were used to estimate the C-12/C-13 abundance ratio. C-17O was detected toward three, and possibly four, envelopes, with sensitive upper limits for two others. The CO-18 variant was detected in two envelopes. New results include determinations of oxygen isotopic ratios in the two carbon-rich protoplanetary nebulae CRL 26688 and CRL 618. As with other classes of red giant stars, the carbon-rich giants seem to be significantly, though variably, enriched in O-17. These results, in combination with observations in interstellar molecular clouds, indicate that current knowledge of stellar production of the CNO nuclides is far from satisfactory.

  11. Organometallic B12-DNA conjugate

    DEFF Research Database (Denmark)

    Hunger, Miriam; Mutti, Elena; Rieder, Alexander;

    2014-01-01

    Design, synthesis, and structural characterization of a B12-octadecanucleotide are presented herein, a new organometallic B12-DNA conjugate. In such covalent conjugates, the natural B12 moiety may be a versatile vector for controlled in vivo delivery of oligonucleotides to cellular targets in hum...

  12. 46 CFR Sec. 12 - Audit.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Audit. Sec. 12 Section 12 Shipping MARITIME... TRANSACTIONS UNDER AGENCY AGREEMENTS Reports and Audit Sec. 12 Audit. (a) The owner will audit as currently as possible subsequent to audit by the agent, all documents relating to the activities, maintenance...

  13. Inorganic carbon acquisition in red tide dinoflagellates.

    Science.gov (United States)

    Rost, Björn; Richter, Klaus-Uwe; Riebesell, Ulf; Hansen, Per Juel

    2006-05-01

    Carbon acquisition was investigated in three marine bloom-forming dinollagellates-Prorocentrum minimum, Heterocapsa triquetra and Ceratium lineatum. In vivo activities of extracellular and intracellular carbonic anhydrase (CA), photosynthetic O2 evolution, CO2 and HCO3- uptake rates were measured by membrane inlet mass spectrometry (MIMS) in cells acclimated to low pH (8.0) and high pH (8.5 or 9.1). A second approach used short-term 14C-disequilibrium incubations to estimate the carbon source utilized by the cells. All three species showed negligible extracellular CA (eCA) activity in cells acclimated to low pH and only slightly higher activity when acclimated to high pH. Intracellular CA (iCA) activity was present in all three species, but it increased only in P. minimum with increasing pH. Half-saturation concentrations (K1/2) for photosynthetic O2 evolution were low compared to ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) kinetics. Moreover, apparent affinities for inorganic carbon (Ci) increased with increasing pH in the acclimation, indicating the operation of an efficient CO2 concentration mechanism (CCM) in these dinoflagellates. Rates of CO2 uptake were comparably low and could not support the observed rates of photosynthesis. Consequently, rates of HCO3- uptake were high in the investigated species, contributing more than 80% of the photosynthetic carbon fixation. The affinity for HCO3- and maximum uptake rates increased under higher pH. The strong preference for HCO3- was also confirmed by the 14C-disequilibrium technique. Modes of carbon acquisition were consistent with the 13C-fractionation pattern observed and indicated a strong species-specific difference in leakage. These results suggest that photosynthesis in marine dinoflagellates is not limited by Ci even at high pH, which may occur during red tides in coastal waters. PMID:17087465

  14. Measurement of the ^12C+^12C Fusion Reaction with MUSIC

    Science.gov (United States)

    Carnelli, P. F. F.; Almaraz-Calderon, S.; Henderson, D.; Rehm, K. E.; Albers, M.; Alcorta, M.; Bertone, P. F.; Esbensen, H.; Fernandez-Niello, J. O.; Jiang, C. L.; Lighthall, J. C.; Marley, S. T.; Palchan-Hazan, T.; Pardo, R. C.; Paul, M.

    2012-10-01

    The fusion of the ^12C+^12C system is of great interest in nuclear structure and nuclear astrophysics. Above the Coulomb barrier, the excitation function of this system exhibits oscillations, which are not well understood. There is also a significant discrepancy between the experimental fusion cross-section and recent coupled-channel calculations that is not present in other carbon systems. To address these issues, we have re-measured the fusion excitation function for ^12,13C+^12C in the energy range of 10 MeV MUSIC) detector. The gas of the ionization chamber (CH4) served as both the target material and the counter gas. One of the main advantages of this method is that the excitation function is measured over a large range of energies using only one beam energy. This method has been proven to be successful and it will be used to measure fusion reactions in other light systems. The experimental results will be presented and compared to previous experimental data and theoretical models.

  15. 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.

  16. The costing of carbon credits from ocean nourishment plants

    International Nuclear Information System (INIS)

    Ocean nourishment is a process for stimulating the sequestration of atmospheric carbon dioxide in the deep ocean by providing the nutrients needed to enhance the production of phytoplankton. The carbon dioxide sink thus created, can be used to generate tradeable carbon credits. The costs of sequestering carbon by the process of ocean nourishment have been estimated using as a basis, the previous experience in nitrogen fixing of Toyo Engineering Corporation. While there are uncertainties about the biological uptake efficiency, these introduce only a moderate uncertainty in our overall estimates of costs. The major determinants of the costs are the interest that must be paid on capital and the cost of the feedstock, natural gas. We have used for discussion purposes, an interest rate of 4-8% per annum and natural gas costs of US$0.5-$2 per GJ. The costs of carbon credits lie in the range US$6.70-$12.40 per tonne of carbon dioxide emissions sequestered. It should be noted that we have adopted the measure of carbon avoided by non-emission, because of the complex partitioning of anthropogenic carbon between the atmosphere, land and ocean

  17. Neutrino neutral-current elastic scattering on 12C

    OpenAIRE

    Butkevich, A. V.; Perevalov, D.

    2011-01-01

    The neutral current elastic scattering of neutrinos on Carbon and $CH_2$ targets is computed using the relativistic distorted-wave impulse approximation with relativistic optical potential. Results for exclusive and inclusive neutrino reactions on ${}^{12}$C target are presented. We show that the nuclear effects on the shape of four-momentum transferred squared distribution $d\\sigma/dQ^2_{QE}$ in neutrino neutral-current and charged-current quasi-elastic scattering are similar. We also calcul...

  18. The oncoprotein H-RasV12 increases mitochondrial metabolism

    Directory of Open Access Journals (Sweden)

    Arumugam Sengodagounder

    2007-12-01

    Full Text Available Abstract Background Neoplastic cells increase glycolysis in order to produce anabolic precursors and energy within the hypoxic environment of a tumor. Ras signaling is activated in several cancers and has been found to regulate metabolism by enhancing glycolytic flux to lactate. We examined the effects of sequential immortalization and H-RasV12-transformation of human bronchial epithelial cells on the anabolic fate of fully-labeled 13C-glucose-derived carbons using two-dimensional total correlated spectroscopic analysis-nuclear magnetic resonance spectroscopy (2D TOCSY-NMR. Results We found that the introduction of activated H-RasV12 into immortalized human bronchial epithelial cells unexpectedly increased tricarboxylic acid cycle activity as measured by the direct conversion of 13C-glucose carbons into the anabolic substrates glutamate/glutamine, aspartate and uridine. We then observed that immortalization and H-RasV12-transformation of bronchial epithelial cells caused a stepwise increase in oxygen consumption, a global measure of electron transport chain activity. Importantly, ectopic expression of H-RasV12 sensitized immortalized cells to the ATP-depleting and cytotoxic effects of electron transport perturbation using the complex I inhibitor rotenone. Conclusion Taken together, these data indicate that the oncoprotein H-RasV12 increases mitochondrial metabolism and provide new rationale for the targeting of the tricarboxylic acid cycle and electron transport chain as anti-neoplastic strategies.

  19. The role of urbanization in the global carbon cycle

    Science.gov (United States)

    Churkina, Galina

    2016-04-01

    Increasing urbanization and global environmental change are two of the grand challenges of the Anthropocene. There are many important connections between these two challenges, which are still poorly understood. The role of urbanization in the global carbon cycle is one of them. Until now, the known facts about the its role encompassed only CO2 emissions. Urban areas account for more than 70% of CO2 emissions from burning fossil fuels. Urban expansion in tropics is responsible for 5% of the annual emissions from land use change. Here I show that the effect of urbanization on the global carbon cycle extends beyond these emissions. I quantify the contribution of urbanization to the major carbon fluxes and pools globally and identify gaps crucial for predicting the evolution of the carbon cycle in the future. Urban residents currently control ~22 (12-40)% of the land carbon uptake (112 PgC/yr) and ~24 (15-39)% of the carbon emissions (117 PgC/yr) from land globally. Urbanization resulted in the creation of new carbon pools on land such as buildings (~6.7 PgC) and landfills (~30 PgC). Together these pools store 1.6 (±0.3)% of the total vegetation and soil carbon pools globally. The creation and maintenance of these new pools has been associated with high emissions of CO2, which are currently better understood than the processes associated with the dynamics of these pools and accompanying uptake of carbon. Predictions of the future trajectories of the global carbon cycle will require a much better understanding of how urban development affects the carbon cycle over the long term.

  20. 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

  1. Decoupling of carbon isotope records between organic matter and carbonate prior to the Toarcian Oceanic Anoxic Event (Early Jurassic)

    Science.gov (United States)

    Bodin, Stephane; Kothe, Tim; Krencker, Francois-Nicolas; Suan, Guillaume; Heimhofer, Ulrich; Immenhauser, Adrian

    2014-05-01

    Across the Pliensbachian-Toarcian boundary (P-To, Early Jurassic), ca. 1 Myr before the Toarcian Oceanic Anoxic Event (T-OAE), an initial negative carbon isotope excursion has been documented in western Tethys sedimentary rocks. In carbonate, its amplitude (2-3 permil) is similar to the subsequent excursion recorded at the onset of the T-OAE. Being also associated with a rapid warming event, the significance of this first carbon isotope shift, in terms of paleoenvironmental interpretation and triggering mechanism, remains however elusive. Taking advantage of expanded and rather continuous sections in the High Atlas of Morocco, several high-resolution, paired organic-inorganic carbon isotope records have been obtained across the Upper Pliensbachian - Lower Toarcian interval. At the onset of the T-OAE, an abrupt 1-2 permil negative shift is recorded in both organic and inorganic phases, succeeded by a relatively longer term 1-2 permil negative trend and a final slow return to pre-excursion conditions. In accordance with previous interpretations, this pattern indicates a perturbation of the entire exogenic carbon isotope reservoir at the onset of the T-OAE by the sudden release of isotopically light carbon into the atmosphere. By contrast, there is no negative shift in carbon isotopes for the P-To event recorded in bulk organic matter of Morocco. Given the strong dominance of terrestrial particles in the bulk organic matter fraction, this absence indicates that massive input of 12C-rich carbon into the atmosphere is not likely to have happened during the P-To event. A pronounced (2 permil) and abrupt negative shift in carbon isotope is however recorded in the bulk carbonate phase. We suggest that this decoupling between organic and inorganic phase is due to changes in the nature of the bulk carbonate phase. Indeed, the negative shift occurs at the lithological transition between Pliensbachian-lowermost Toarcian limestone-marl alternations and the Lower Toarcian marl

  2. 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.

  3. 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

  4. Chapter 12. Public information

    International Nuclear Information System (INIS)

    'Nuclear Power Engineering Safety' running substantial articles from major UJD activities. The double issues 7/8 and 11/12 (2000) included safety analyses - NPP V-1 Bohunice and NPP Mochovce units safety assessment. The monthly 'Verejna sprava' (Public Administration) ran in 2000 two substantial articles on UJD legislative and state law activities. Contributions on UJD regulatory activity and international co-operation appear on a regular basis in 'Spravodajstvo SE, a.s.' (SE, a.s., Newsletter) and in-house journals 'Mochovce' and 'Bohunice'. UJD domestic and foreign activities were published in 5 issues in 'Slovak Nuclear Society (SNUS) Bulletin'. A report on the safety of nuclear installations and the management of spent nuclear fuel and radioactive wastes in the Slovak Republic in the journal 'Nuclear Europe Worldscan' No. 7-8/2000 was also published the year 2000. A number of substantial articles were published in the magazine Energia. A contribution on UJD's mission and tasks in the Slovak Republic was published in 'Energia Almanach' 2000/2001. Six contributions focused on UJD's domestic and foreign activities were prepared for the world information agency NucNet. A Slovak-English information material on UJD (12/2000) was prepared and published for the public. Also the Slovak-English 1999 Annual Report on the results of UJD activity and nuclear installation safety in the Slovak Republic was prepared and published. In 2000, four press conferences were held at UJD, with follow-up appearances by UJD management in television and radio. UJD executives made five appearances in television and gave six interviews and seven relevant interviews for Slovak Radio and magazines and dailies, respectively. In 2000, two video-clips were produced for the public, namely on the 'UJD tasks and mission' and 'emergency planning'. A highly successful press conference on Slovakia's NPP safety was arranged by UJD on the occasion of the visit to Slovakia by the OECD/ Nuclear Energy Agency

  5. Enigma Version 12

    Science.gov (United States)

    Shores, David; Goza, Sharon P.; McKeegan, Cheyenne; Easley, Rick; Way, Janet; Everett, Shonn; Guerra, Mark; Kraesig, Ray; Leu, William

    2013-01-01

    Enigma Version 12 software combines model building, animation, and engineering visualization into one concise software package. Enigma employs a versatile user interface to allow average users access to even the most complex pieces of the application. Using Enigma eliminates the need to buy and learn several software packages to create an engineering visualization. Models can be created and/or modified within Enigma down to the polygon level. Textures and materials can be applied for additional realism. Within Enigma, these models can be combined to create systems of models that have a hierarchical relationship to one another, such as a robotic arm. Then these systems can be animated within the program or controlled by an external application programming interface (API). In addition, Enigma provides the ability to use plug-ins. Plugins allow the user to create custom code for a specific application and access the Enigma model and system data, but still use the Enigma drawing functionality. CAD files can be imported into Enigma and combined to create systems of computer graphics models that can be manipulated with constraints. An API is available so that an engineer can write a simulation and drive the computer graphics models with no knowledge of computer graphics. An animation editor allows an engineer to set up sequences of animations generated by simulations or by conceptual trajectories in order to record these to highquality media for presentation. Enigma Version 12 Lyndon B. Johnson Space Center, Houston, Texas 28 NASA Tech Briefs, September 2013 Planetary Protection Bioburden Analysis Program NASA's Jet Propulsion Laboratory, Pasadena, California This program is a Microsoft Access program that performed statistical analysis of the colony counts from assays performed on the Mars Science Laboratory (MSL) spacecraft to determine the bioburden density, 3-sigma biodensity, and the total bioburdens required for the MSL prelaunch reports. It also contains numerous

  6. Terrestrial Carbon Cycle Variability

    Science.gov (United States)

    Baldocchi, Dennis; Ryu, Youngryel; Keenan, Trevor

    2016-01-01

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

  7. The GLOBE Carbon Cycle Project: Using a systems approach to understand carbon and the Earth's climate system

    Science.gov (United States)

    Silverberg, S. K.; Ollinger, S. V.; Martin, M. E.; Gengarelly, L. M.; Schloss, A. L.; Bourgeault, J. L.; Randolph, G.; Albrechtova, J.

    2009-12-01

    National Science Content Standards identify systems as an important unifying concept across the K-12 curriculum. While this standard exists, there is a recognized gap in the ability of students to use a systems thinking approach in their learning. In a similar vein, both popular media as well as some educational curricula move quickly through climate topics to carbon footprint analyses without ever addressing the nature of carbon or the carbon cycle. If students do not gain a concrete understanding of carbon’s role in climate and energy they will not be able to successfully tackle global problems and develop innovative solutions. By participating in the GLOBE Carbon Cycle project, students learn to use a systems thinking approach, while at the same time, gaining a foundation in the carbon cycle and it's relation to climate and energy. Here we present the GLOBE Carbon Cycle project and materials, which incorporate a diverse set of activities geared toward upper middle and high school students with a variety of learning styles. A global carbon cycle adventure story and game let students see the carbon cycle as a complete system, while introducing them to systems thinking concepts including reservoirs, fluxes and equilibrium. Classroom photosynthesis experiments and field measurements of schoolyard vegetation brings the global view to the local level. And the use of computer models at varying levels of complexity (effects on photosynthesis, biomass and carbon storage in global biomes, global carbon cycle) not only reinforces systems concepts and carbon content, but also introduces students to an important scientific tool necessary for understanding climate change.

  8. 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.

  9. 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...

  10. Noncovalent Attachment of PbS Quantum Dots to Single- and Multiwalled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Anirban Das

    2014-01-01

    Full Text Available Attachment of PbS quantum dots (QD to single-walled carbon nanotubes (SWNT and multiwalled carbon nanotubes (MWCNT is described; wherein commercially obtained PbS-QD of size 2.7 nm, stabilized by oleic acid, are added to a suspension of single- or multiwalled carbon nanotubes (CNT prefunctionalized noncovalently with 1,2-benzenedimethanethiol (1,2-BDMT in ethanol. The aromatic part of 1,2-BDMT attaches to the CNT by π-π stacking interactions, noncovalently functionalizing the CNT. The thiol part of the 1,2-BDMT on the functionalized CNT replaces oleic acid on the surface of the QD facilitating the noncovalent attachment of the QD to the CNT. The composites were characterized by TEM and FTIR spectroscopy. Quenching of NIR fluorescence of the PbS-QD on attachment to the carbon nanotubes (CNT was observed, indicating FRET from the QD to the CNT.

  11. Supercritical carbon dioxide (SC-CO2 as a clean technology for palm kernel oil extraction

    Directory of Open Access Journals (Sweden)

    Norhuda I

    2009-04-01

    Kyoto Protocol. Keywords: By-product, Solvent extraction, Kyoto protocol, Supercritical Carbon Dioxide, Palm Kernel Oil Received: 13 July 2008 / Received in revised form: 17 February 2009, Accepted: 28 February 2009, Published online: 12 March 2009

  12. Microbiological quality of carbonated drinking water produced with in-home carbonation systems.

    Science.gov (United States)

    Kohnen, Wolfgang; Teske-Keiser, Susanne; Meyer, Heinz-Georg; Loos, Anja H; Pietsch, Michael; Jansen, Bernd

    2005-01-01

    The microbiological quality of carbonated water produced with tap water in commercial in-home carbonation systems was determined, the results being discussed in the context of the microbiological quality of the tap water used, the properties of the drink makers, and the procedures of preparation and washing of various parts of the appliance. The last-mentioned data were received from each participant of the study by questionnaire. Escherichia coli, coliforms, fecal streptococci and spore-forming sulphite-reducing anaerobes were used as indicators for the hygienic quality of the water. Tap-water samples were collected according to the usual procedure when filling the carbonating bottle, i.e., without previous flushing and disinfection of the faucet. In 12% of tap-water samples, coliforms could be detected. On the other hand, in 20 of 52 carbonated waters (39%), coliforms as indicators of water pollution were found. By means of fecal streptococci and Pseudomonas aeruginosa, it was possible to establish additional contamination not involving E. coli or coliforms alone. Analysis revealed that, in addition to contaminated tap water, a bacterial biofilm on the inner surface of the re-usable bottles had a predominant influence on the microbiological quality of the carbonated water.

  13. Influence of soil moisture-carbon cycle interactions on the terrestrial carbon cycle over Europe

    Science.gov (United States)

    Mystakidis, Stefanos; Davin, Edouard L.; Gruber, Nicolas; Seneviratne, Sonia I.

    2016-04-01

    Water availability is a crucial limiting factor for terrestrial ecosystems, but relatively few studies have quantitatively assessed the influence of soil moisture variability on the terrestrial carbon cycle. Here, we investigate the role of soil moisture variability and state in the contemporary terrestrial carbon cycle over Europe. For this we use a Regional Earth System Model (RESM) based on the COSMO-CLM Regional Climate Model, coupled to the Community Land Model version 4.0 (CLM4.0) and its carbon-nitrogen module. The simulation setup consists of a control simulation over the period 1979-2010 in which soil moisture is interactive and three sensitivity simulations in which soil moisture is prescribed to a mean, a very dry or a very wet seasonal cycle without inter-annual variability. The cumulative net biome productivity varies markedly between the different experiments ranging from a strong sink of up to 6PgC in the wet experiment to a source of up to 1.2PgC in the dry experiment. Changes in the land carbon uptake are driven by a combination of two factors: the direct impact of soil moisture on plant's carbon uptake (essentially in southern Europe) and an indirect effect through changes in temperature affecting ecosystem respiration (mainly in central and northern Europe). We find that removing temporal variations in soil moisture dampens interannual variations in terrestrial carbon fluxes (Gross Primary Productivity, respiration, Net Biome Productivity) by more than 50% over most of Europe. Moreover, the analysis reveals that on annual scale about two-thirds of central Europe and about 70% of southern Europe display statistically significant effect of drying and/or wetting on the terrestrial carbon budget and its components. Our findings confirm the crucial role of soil moisture in determining the magnitude and the inter-annual variability in land CO2 uptake which is a key contributor to the year-to-year variations in atmospheric CO2 concentration.

  14. Flexible Carbon Aerogels

    Directory of Open Access Journals (Sweden)

    Marina Schwan

    2016-09-01

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

  15. Securing tropical forest carbon

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  16. 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

  17. 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...

  18. Canopy-scale kinetic fractionation of atmospheric carbon dioxide and water vapour isotopes

    Science.gov (United States)

    The isotopic fluxes of carbon dioxide (CO2) and water vapour (H2O) between the atmosphere and terrestrial plants provide powerful constraints on carbon sequestration on land 1-2, changes in vegetation cover 3 and the Earth’s Dole effect 4. Past studies, relying mainly on leaf-scale observations, hav...

  19. Oxygen electrode reaction in molten carbonate fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Appleby, A.J.; White, R.E.

    1992-07-07

    Molten carbonate fuel cell system is a leading candidate for the utility power generation because of its high efficiency for fuel to AC power conversion, capability for an internal reforming, and a very low environmental impact. However, the performance of the molten carbonate fuel cell is limited by the oxygen reduction reaction and the cell life time is limited by the stability of the cathode material. An elucidation of oxygen reduction reaction in molten alkali carbonate is essential because overpotential losses in the molten carbonate fuel cell are considerably greater at the oxygen cathode than at the fuel anode. Oxygen reduction on a fully-immersed gold electrode in a lithium carbonate melt was investigated by electrochemical impedance spectroscopy and cyclic voltammetry to determine electrode kinetic and mass transfer parameters. The dependences of electrode kinetic and mass transfer parameters on gas composition and temperature were examined to determine the reaction orders and the activation energies. The results showed that oxygen reduction in a pure lithium carbonate melt occurs via the peroxide mechanism. A mass transfer parameter, D{sub O}{sup 1/2}C{sub O}, estimated by the cyclic voltammetry concurred with that calculated by the EIS technique. The temperature dependence of the exchange current density and the product D{sub O}{sup 1/2}C{sub O} were examined and the apparent activation energies were determined to be about 122 and 175 kJ/ mol, respectively.

  20. Kinetic study of uranium carburization by different carbonated gases

    International Nuclear Information System (INIS)

    The kinetic study of the reaction U + CO2 and U + CO has been performed by a thermogravimetric method on a spherical uranium powder, in temperature ranges respectively from 460 to 690 deg. C and from 570 to 850 deg. C. The reaction with carbon dioxide leads to uranium dioxide. A carbon deposition takes place at the same time. The global reactions is the result of two reactions: U + 2 CO2 → UO2 + 2 CO U + CO2 → UO2 + C The reaction with carbon monoxide leads to a mixture of dioxide UO2, dicarbide UC2 and free carbon. The main reaction can be written. U + CO → 1/2 UO2 + 1/2 UC2 The free carbon results of the disproportionation of the carbon monoxide. A remarkable separation of the two phases UO2 and UC2 can be observed. A mechanism accounting for the phenomenon has been proposed. The two reactions U + CO2 and U + CO begin with a long germination period, after which, the reaction velocity seems to be limited in both cases by the ionic diffusion of oxygen through the uranium dioxide. (author)

  1. 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

  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. 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...

  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. 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.

  6. B12 in fetal development.

    Science.gov (United States)

    Pepper, M Reese; Black, Maureen M

    2011-08-01

    Vitamin B12 (cobalamin) is necessary for development of the fetus and child. Pregnant women who are vegetarian or vegan, have Crohn's or celiac disease, or have undergone gastric bypass surgery are at increased risk of B12 deficiency. Low serum levels of B12 have been linked to negative impacts in cognitive, motor, and growth outcomes. Low cobalamin levels also may be related to depression in adults. Some studies indicate that B12 supplementation may improve outcomes in children, although more research is needed in this area. Overall, the mechanisms of B12 action in development remain unclear. Further studies in this area to elucidate the pathways of cobalamin influence on development, as well as to prevent B12 deficiency in pregnant women and children are indicated.

  7. Global Distribution of Pyrogenic Carbon

    Science.gov (United States)

    Reisser, Moritz; Abiven, Samuel; Schmidt, Michael W. I.

    2016-04-01

    Pyrogenic Carbon (PyC) is ubiquitous in the environment and represents presumably one of the most stable compounds of the total organic carbon. Due to its persistence in the soil, it might play an important role in the global carbon cycle. In order to model future CO2 emissions from soils it is thus crucial to know where and how much of PyC exists on a global scale. Yet, only rough estimates for global PyC stocks in soils could be made, and even less is known about the distribution across ecosystems. Therefore we propose here literature analysis of data on PyC concentrations and stocks worldwide. We extracted PyC values in soils from the literature (n = 600) and analysed the percentage of PyC in the soil organic carbon (SOC) as a function of climate (temperature, precipitation), soil parameters (pH, clay content), fire characteristics (fire frequency and fire regime) and land use. Overall, the average contribution of PyC to SOC was 13 %, ranging from 0.1 % up to 60 %. We observed that the PyC content was significantly higher with high clay content, higher pH, and in cultivated land as compared to forest and grassland. We did not observe any relationships between fire activity, frequency or intensity and PyC % at a global scale. When the fire regime was monitored on site (only 12 % of the data we collected), we observed higher PyC concentrations with higher fire frequencies. We hypothesise that the resolution of global fire datasets is neither temporally nor spatially high enough to explain the very local fire history of the soil samples. Data points were not homogeneously distributed on the globe, but rather aggregated in places like Central Europe, the Russian Steppe or North America. Therefore, a global interpolation is not directly possible. We modelled PyC concentrations, based on the five most significant parameters, which were clay content, pH, mean annual temperature and precipitation as well as land use. We then predicted worldwide PyC using global datasets

  8. Realistic costs of carbon capture

    Energy Technology Data Exchange (ETDEWEB)

    Al Juaied, Mohammed (Harvard Univ., Cambridge, MA (US). Belfer Center for Science and International Affiaris); Whitmore, Adam (Hydrogen Energy International Ltd., Weybridge (GB))

    2009-07-01

    There is a growing interest in carbon capture and storage (CCS) as a means of reducing carbon dioxide (CO2) emissions. However there are substantial uncertainties about the costs of CCS. Costs for pre-combustion capture with compression (i.e. excluding costs of transport and storage and any revenue from EOR associated with storage) are examined in this discussion paper for First-of-a-Kind (FOAK) plant and for more mature technologies, or Nth-of-a-Kind plant (NOAK). For FOAK plant using solid fuels the levelised cost of electricity on a 2008 basis is approximately 10 cents/kWh higher with capture than for conventional plants (with a range of 8-12 cents/kWh). Costs of abatement are found typically to be approximately US$150/tCO2 avoided (with a range of US$120-180/tCO2 avoided). For NOAK plants the additional cost of electricity with capture is approximately 2-5 cents/kWh, with costs of the range of US$35-70/tCO2 avoided. Costs of abatement with carbon capture for other fuels and technologies are also estimated for NOAK plants. The costs of abatement are calculated with reference to conventional SCPC plant for both emissions and costs of electricity. Estimates for both FOAK and NOAK are mainly based on cost data from 2008, which was at the end of a period of sustained escalation in the costs of power generation plant and other large capital projects. There are now indications of costs falling from these levels. This may reduce the costs of abatement and costs presented here may be 'peak of the market' estimates. If general cost levels return, for example, to those prevailing in 2005 to 2006 (by which time significant cost escalation had already occurred from previous levels), then costs of capture and compression for FOAK plants are expected to be US$110/tCO2 avoided (with a range of US$90-135/tCO2 avoided). For NOAK plants costs are expected to be US$25-50/tCO2. Based on these considerations a likely representative range of costs of abatement from CCS

  9. Influence of impurity on electronic properties of carbon nanotube superlattices

    Directory of Open Access Journals (Sweden)

    AA Shokri

    2013-09-01

    Full Text Available   In this paper, electronic properties of single-wall armchair and zigzag carbon nanotubes (CNTs superlattices, n(12,0/m(6,6 and n(12,0/m(11,0 are investigated. For this reason, the topological defects of pentagon–heptagon pairs at interfaces of carbon hexagonal network appear. These defects break the symmetry of the system, and then change the electrical properties. The calculations include two parts: investigation of the structures in the absence and presence of the impurity effect, which are calculated by the nearest-neighbor tight binding model . Out numerical results can be useful in designing nanoelectronic devices based on carbon nanotubes.

  10. 12 CFR 905.12 - Office of Management.

    Science.gov (United States)

    2010-01-01

    ... on management and organizational policies and is responsible for the Finance Board's administrative... programs; (4) Agency financial management, budgeting and accounting; (5) Records management; and (6... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Office of Management. 905.12 Section...

  11. 12 CFR 370.12 - Payment on the guarantee.

    Science.gov (United States)

    2010-01-01

    ... transaction deposit accounts in such entities will be paid in accordance with 12 U.S.C. 1821(f) and 12 CFR... satisfaction. Payment under paragraph (b)(2) of this section shall constitute, to the extent of payments made, satisfaction of all FDIC obligations under the debt guarantee program with respect to that debtholder...

  12. Warkworth 12-m VLBI Station: WARK12M - 2012

    CERN Document Server

    Weston, Stuart; Natusch, Tim; Gulyaev, Sergei

    2013-01-01

    The Warkworth 12-m Radio Telescope is operated by the Institute for Radio Astronomy and Space Research (IRASR) at AUT University, Auckland, New Zealand. This report briefly reviews the characteristics of the 12-m VLBI station. We report on a number of activities and technical developments.

  13. 12 CFR 337.12 - Frequency of examination.

    Science.gov (United States)

    2010-01-01

    ...) The bank has total assets of less than $500 million; (2) The bank is well capitalized as defined in... examination, the FDIC— (i) Assigned the bank a rating of 1 or 2 for management as part of the bank's composite... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Frequency of examination. 337.12 Section...

  14. Geochemistry of carbon stable isotopes in the sea

    International Nuclear Information System (INIS)

    This paper describes geochemical process which affect the distribution in the sea of the 13C/12C ratio of total inorganic dissolved CO2; synthesis of the biomass and respiratory phenomena; oxidation of organic matter; dissolution of carbonates; run off waters; exchange of CO2 between sea and atmosphere. Some applications to the paleoclimatology are presented. (author)

  15. Supercritical carbon dioxide process for pasteurization of fruit juices

    Science.gov (United States)

    Supercritical carbon dioxide (SCCO2) nonthermal processing inactivates microorganisms in juices using non-toxic and non-reactive CO2. However, data is lacking on the inactivation of E. coli K12 and L. plantarum in apple cider using pilot plant scale SCCO2 equipment. For this study, pasteurized pres...

  16. Terrestrial carbon isotope excursions and biotic change during Palaeogene hyperthermals

    NARCIS (Netherlands)

    Abels, H.A.; Clyde, W.C.; Gingerich, P.D.; Hilgen, F.J.; Fricke, H.C.; Bowen, G.J.; Lourens, L.J.

    2012-01-01

    Pronounced transient global warming events between 60 and 50 million years ago have been linked to rapid injection of isotopically-light carbon to the ocean–atmosphere system1,2. It is, however, unclear whether the largest of the hyperthermals, the Palaeocene–Eocene Thermal Maximum (PETM; ref. 3), h

  17. Oracle 12c for dummies

    CERN Document Server

    Ruel, Chris

    2013-01-01

    Demystifying the power of the Oracle 12c database The Oracle database is the industry-leading relational database management system (RDMS) used from small companies to the world's largest enterprises alike for their most critical business and analytical processing. Oracle 12c includes industry leading enhancements to enable cloud computing and empowers users to manage both Big Data and traditional data structures faster and cheaper than ever before. Oracle 12c For Dummies is the perfect guide for a novice database administrator or an Oracle DBA who is new to Oracle 12c. The book covers what

  18. Deadwood biomass: an underestimated carbon stock in degraded tropical forests?

    Science.gov (United States)

    Pfeifer, Marion; Lefebvre, Veronique; Turner, Edgar; Cusack, Jeremy; Khoo, MinSheng; Chey, Vun K.; Peni, Maria; Ewers, Robert M.

    2015-04-01

    Despite a large increase in the area of selectively logged tropical forest worldwide, the carbon stored in deadwood across a tropical forest degradation gradient at the landscape scale remains poorly documented. Many carbon stock studies have either focused exclusively on live standing biomass or have been carried out in primary forests that are unaffected by logging, despite the fact that coarse woody debris (deadwood with ≥10 cm diameter) can contain significant portions of a forest’s carbon stock. We used a field-based assessment to quantify how the relative contribution of deadwood to total above-ground carbon stock changes across a disturbance gradient, from unlogged old-growth forest to severely degraded twice-logged forest, to oil palm plantation. We measured in 193 vegetation plots (25 × 25 m), equating to a survey area of >12 ha of tropical humid forest located within the Stability of Altered Forest Ecosystems Project area, in Sabah, Malaysia. Our results indicate that significant amounts of carbon are stored in deadwood across forest stands. Live tree carbon storage decreased exponentially with increasing forest degradation 7-10 years after logging while deadwood accounted for >50% of above-ground carbon stocks in salvage-logged forest stands, more than twice the proportion commonly assumed in the literature. This carbon will be released as decomposition proceeds. Given the high rates of deforestation and degradation presently occurring in Southeast Asia, our findings have important implications for the calculation of current carbon stocks and sources as a result of human-modification of tropical forests. Assuming similar patterns are prevalent throughout the tropics, our data may indicate a significant global challenge to calculating global carbon fluxes, as selectively-logged forests now represent more than one third of all standing tropical humid forests worldwide.

  19. High-spin molecular resonances in 12C + 12C

    Science.gov (United States)

    Uegaki, E.; Abe, Y.

    2016-05-01

    Resonances observed in the 12C + 12C collisions are studied with a molecular model. At high spins J = 10-18, a stable dinuclear configuration is found to be an equator-equator touching one. Firstly, normal modes have been solved around the equilibrium, with spin J and K-quantum number being specified for rotation of the whole system. Secondly, with respect to large centrifugal energy, Coriolis coupling has been diagonalized among low-lying 11 states of normal-mode excitations, which brings K-mixing. The analyses of decay widths and excitation functions have been done. The molecular ground state exhibits alignments of the orbital angular momentum and the 12C spins, while some of the molecular excited states exhibit disalignments with small widths. Those results are surprisingly in good agreement with the experiments, which will light up a new physical picture of the highspin 12C + 12C resonances.

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

    Energy Technology Data Exchange (ETDEWEB)

    Naskar, Amit K.

    2015-08-04

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

  1. Carbon allocation belowground in Pinus pinaster using stable carbon isotope pulse labeling technique

    Science.gov (United States)

    Dannoura, M.; Bosc, A.; Chipeaux, C.; Sartore, M.; Lambrot, C.; Trichet, P.; Bakker, M.; Loustau, D.; Epron, D.

    2010-12-01

    Carbon allocation belowground competes with aboveground growth and biomass production. In the other hand, it contributes to resource acquisition such as nutrient, water and carbon sequestration in soil. Thus, a better characterization of carbon flow from plant to soil and its residence time within each compartment is an important issue for understanding and modeling forest ecosystem carbon budget. 13C pulse labeling of whole crown was conducted at 4 seasons to study the fate of assimilated carbon by photosynthesis into the root on 12 year old Pinus pinaster planted in the INRA domain of Pierroton. Maritime pine is the most widely planted species in South-West Europe. Stem, root and soil CO2 effluxes and their isotope composition were measured continuously by tunable diode laser absorption spectroscopy with a trace gas analyzer (TGA 100A; Campbell Scientific) coupled to flow-through chambers. 13CO2 recovery and peak were observed in respiration of each compartment after labeling. It appeared sequentially from top of stem to bottom, and to coarse root. The maximum velocity of carbon transfer was calculated as the difference in time lag of recovery between two positions on the trunk or on the root. It ranged between 0.08-0.2 m h-1 in stem and between 0.04-0.12 m h-1 in coarse root. This velocity was higher in warmer season, and the difference between time lag of recovery and peak increased after first frost. Photosynthates arrived underground 1.5 to 5 days after labeling, at similar time in soil CO2 effluxes and coarse root respiration. 0.08-1.4 g of carbon was respired per tree during first 20 days following labeling. It presented 0.6 -10% of 13C used for labeling and it is strongly related to seasons. The isotope signal was detected in fine root organs and microbial biomass by periodical core sampling. The peak was observed 6 days after labeling in early summer while it was delayed more than 10 days in autumn and winter with less amount of carbon allocated

  2. 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.

  3. Lithium Titanate Confined in Carbon Nanopores for Asymmetric Supercapacitors.

    Science.gov (United States)

    Zhao, Enbo; Qin, Chuanli; Jung, Hong-Ryun; Berdichevsky, Gene; Nese, Alper; Marder, Seth; Yushin, Gleb

    2016-04-26

    Porous carbons suffer from low specific capacitance, while intercalation-type active materials suffer from limited rate when used in asymmetric supercapacitors. We demonstrate that nanoconfinement of intercalation-type lithium titanate (Li4Ti5O12) nanoparticles in carbon nanopores yielded nanocomposite materials that offer both high ion storage density and rapid ion transport through open and interconnected pore channels. The use of titanate increased both the gravimetric and volumetric capacity of porous carbons by more than an order of magnitude. High electrical conductivity of carbon and the small size of titanate crystals allowed the composite electrodes to achieve characteristic charge and discharge times comparable to that of the electric double-layer capacitors. The proposed composite synthesis methodology is simple, scalable, and applicable for a broad range of active intercalation materials, while the produced composite powders are compatible with commercial electrode fabrication processes. PMID:26950509

  4. Anomalous carbon-isotope ratios in nonvolatile organic material.

    Science.gov (United States)

    Kaplan, I R; Nissenbaum, A

    1966-08-12

    Organic mats are associated with sulfur deposits in Upper Pleistocene sand ridges of the coastal plain of southern Israel; black, brittle, and non-volatile, they show parallel layering but no other apparent cellular structure. Two independent carbon-14 determinations yielded ages of 27,750+/-500 and 31,370+/-1400 years. Four carbon-13:carbon-12 determinations fell within the range deltaC(13) =-82.5 to -89.3 per mille relative to the PDB standard; these appear to be the lowest values yet reported for naturally occurring high-molecular-weight organic material. The origin of the carbon is probably complex; it must have passed through at least one biologic cycle before final deposition.

  5. Hybrid carbon nanostructure assemblage for high performance pseudo-capacitors

    Directory of Open Access Journals (Sweden)

    A. K. Mishra

    2012-06-01

    Full Text Available Investigation of novel nanocomposites for pseudo-capacitors with high capacitance and energy density is the spotlight of current energy research. In the present work, hybrid carbon nanostructure assemblage of graphene and multiwalled carbon nanotubes has been used as carbon support to nanostructured RuO2 and polyaniline for high energy supercapacitors. Maximum specific capacitances of 110, 235 and 440 F g−1 at the voltage sweep rate of 10 mV s−1 and maximum energy densities of 7, 12.5 and 20.5 Wh kg−1 were observed for carbon assemblage and its RuO2 and polyanilne decorated nanocomposites, respectively, with 1M H2SO4 as electrolyte.

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

    Institute of Scientific and Technical Information of China (English)

    ZHANG Can; LU Guimin; SUN Ze; YU Jianguo

    2012-01-01

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

  7. Operational damage of steel 12Kh1MF steam superheater tubes

    International Nuclear Information System (INIS)

    The structure and mechanical properties of steel 12Kh1MF specimens are investigated after cyclic tests under conditions simulating operational regime of steam superheater tubes. It is revealed that in thermal barocycling a decrease of steel strength and a transition from trans crystalline to intercrystalline feature take place due to precipitation of complex carbides along grain boundaries. Complex carbide formation is resulted from the appearance of free carbon of decomposed carbon-containing organic impurities in a water coolant

  8. Carbon Monoxide Information Center

    Medline Plus

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

  9. Carbon Monoxide Poisoning

    OpenAIRE

    Wray, Alisa

    2016-01-01

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

  10. Closing carbon cycles

    NARCIS (Netherlands)

    Patel, Martin

    2001-01-01

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

  11. Carbon Monoxide Information Center

    Medline Plus

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

  12. Carbon nanotube solar cells.

    Directory of Open Access Journals (Sweden)

    Colin Klinger

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

  13. Skallerup Klit's carbon footprint

    DEFF Research Database (Denmark)

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

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

  14. Polyimide/carbon Nanocomposites

    Science.gov (United States)

    Harris, Frank W.

    2003-01-01

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

  15. City Carbon Footprint Networks

    Directory of Open Access Journals (Sweden)

    Guangwu Chen

    2016-07-01

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

  16. Bioenergy, the Carbon Cycle, and Carbon Policy

    Science.gov (United States)

    Kammen, D. M.

    2003-12-01

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

  17. Supercapacitor carbon electrodes from pyrolyzed glycerol

    International Nuclear Information System (INIS)

    In this study pyrolyzed glycerol was explored as electrode material using a catalytic agent during pyrolysis. Here, evaporation of glycerol at high temperatures was prevented by catalyzing the formation of oligoglycerol in turn leading to carbonization above 300 °C. A one-step and tow-step pyrolysis process were developed and compared based on the suercapacitive properties of the carbon material. The pyrolysis of the glycerol was performed at 600 °C for 1 hour under nitrogen atmosphere. The product obtained was washed with 1 M HCl, and characterized using scanning electron microscopy (SEM), nitrogen adsorption (BET surface analysis), Fourier transform infrared (FTIR) spectroscopy, cyclic voltammetry, and galvanostatic charge-discharge measurements. Carbon percent yields of 4-6% were obtained for the two different processes. The one-step process was found to have slightly higher yields. FTIR spectroscopy showed that majority of the functional groups had been removed during the pyrolysis process. SEM images show no significant difference in the surface morphology and porosity from the products of the two processes. Fabricated electrodes showed specific capacitances ranging from 0.25 Fg-“1 to 1.36 Fg-“1 through cyclic voltammetry in 1 M Li2SO4 with a sweep rate of 100 mV s”-“1 and galvonostatic cycling with a current of 1 and 5 mA from 0 to 1.2 V. These results show the potential use of carbon from pyrolysis of glycerol as active component in carbon-based supercapacitors. (author)

  18. Carbon pathways in the Seine river system

    Science.gov (United States)

    Marescaux, Audrey; Garnier, Josette; Thieu, Vincent

    2016-04-01

    Many papers have recently suggested that the anthropogenic perturbations of the carbon cycle have led to a significant increase in carbon export from terrestrial ecosystems to inland waters. The quantification of the carbon cascade (including fate of CO2 emissions) in highly anthropized river systems is thus essential to understand the response of aquatic systems. The Seine Basin where Paris and its environs represent 2/3 of its population, and agriculture is particularly intensive, is a eutrophic system. The main aim of this research is to understand and quantify how an excess of anthropogenic nutrients entering the Seine River system may locally enhance primary production, C sequestration, C respiration and CO2 emissions. The development of a new CO2 module in the pre-existing biogeochemical Riverstrahler model (Billen et al., 2007) should enable a refined calculation of the carbon budget. Besides calculation of the Respiration and Production activities along the entire river continuum, it will directly associate CO2 emissions. The CO2 modelling results will be confronted to (i) direct (in-situ) measurements with a non-dispersive infrared gas analyzer and (ii) indirect measurements based on total alkalinity, carbonate and pH along the Seine river system during the last decades, and (iii) calculations of a C metabolism budget. Billen, G., Garnier, J., Némery, J., Sebilo, M., Sferratore, A., Barles, S., Benoit P., Benoît, M. (2007). A long-term view of nutrient transfers through the Seine river continuum. Science of the Total Environment, 375(1-3), 80-97. http://doi.org/10.1016/j.scitotenv.2006.12.005

  19. Ionization and photofragmentation of Ru3(CO)12 and Os3(CO)12

    International Nuclear Information System (INIS)

    In this paper, we use a combination of photoelectron spectroscopy, mass spectrometry, and density functional theory calculations to get a detailed understanding of valence single and double ionization and the subsequent dissociation processes. This is exemplified on benchmark systems, trimetallo-dodecacarbonyls M3(CO)12 with M = Ru, Os, where the energy remaining in the molecule after photoionization can be retrieved by measuring the degree of fragmentation of the molecular ion. The intensity of different mass peaks can thus be directly related to ionization cross sections obtained by photoelectron spectroscopy. We find that the M—CO dissociation energy rises as the number of CO ligands decreases due to dissociation. Moreover, ionization of the CO ligands has a higher cross section than that of the metal center for both single and double ionization. After advanced fragmentation, a CO bond can break and the carbon atom remains bonded to the metal core. In addition, we found that the valence ionization cross sections of M3(CO)12 are maximal at about 40 eV photon energy thus showing a more pronounced shape resonance than Ru and Os-complexes with a single metal atom center. Finally, an np → nd giant resonance absorption causes a significant increase of the ionization cross section above 50 eV for Ru3(CO)12

  20. Ionization and photofragmentation of Ru3(CO)12 and Os3(CO)12

    Science.gov (United States)

    Schalk, Oliver; Josefsson, Ida; Richter, Robert; Prince, Kevin C.; Odelius, Michael; Mucke, Melanie

    2015-10-01

    In this paper, we use a combination of photoelectron spectroscopy, mass spectrometry, and density functional theory calculations to get a detailed understanding of valence single and double ionization and the subsequent dissociation processes. This is exemplified on benchmark systems, trimetallo-dodecacarbonyls M3(CO)12 with M = Ru, Os, where the energy remaining in the molecule after photoionization can be retrieved by measuring the degree of fragmentation of the molecular ion. The intensity of different mass peaks can thus be directly related to ionization cross sections obtained by photoelectron spectroscopy. We find that the M—CO dissociation energy rises as the number of CO ligands decreases due to dissociation. Moreover, ionization of the CO ligands has a higher cross section than that of the metal center for both single and double ionization. After advanced fragmentation, a CO bond can break and the carbon atom remains bonded to the metal core. In addition, we found that the valence ionization cross sections of M3(CO)12 are maximal at about 40 eV photon energy thus showing a more pronounced shape resonance than Ru and Os-complexes with a single metal atom center. Finally, an np → nd giant resonance absorption causes a significant increase of the ionization cross section above 50 eV for Ru3(CO)12.

  1. Carbon nanotube macroelectronics

    Science.gov (United States)

    Zhang, Jialu

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

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

    Directory of Open Access Journals (Sweden)

    Sandra Fernanda Nunes

    2012-12-01

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

  3. Twelve metropolitan carbon footprints. A preliminary comparative global assessment

    International Nuclear Information System (INIS)

    A dearth of available data on carbon emissions and comparative analysis between metropolitan areas make it difficult to confirm or refute best practices and policies. To help provide benchmarks and expand our understanding of urban centers and climate change, this article offers a preliminary comparison of the carbon footprints of 12 metropolitan areas. It does this by examining emissions related to vehicles, energy used in buildings, industry, agriculture, and waste. The carbon emissions from these sources - discussed here as the metro area's partial carbon footprint - provide a foundation for identifying the pricing, land use, help metropolitan areas throughout the world respond to climate change. The article begins by exploring a sample of the existing literature on urban morphology and climate change and explaining the methodology used to calculate each area's carbon footprint. The article then depicts the specific carbon footprints for Beijing, Jakarta, London, Los Angeles, Manila, Mexico City, New Delhi, New York, Sao Paulo, Seoul, Singapore, and Tokyo and compares these to respective national averages. It concludes by offering suggestions for how city planners and policymakers can reduce the carbon footprint of these and possibly other large urban areas. (author)

  4. Sequestration of carbon dioxide (CO2) using red mud.

    Science.gov (United States)

    Yadav, Vishwajeet S; Prasad, Murari; Khan, Jeeshan; Amritphale, S S; Singh, M; Raju, C B

    2010-04-15

    Red mud, an aluminium industry hazardous waste, has been reported to be an inexpensive and effective adsorbent. In the present work applicability of red mud for the sequestration of green house gases with reference to carbon dioxide has been studied. Red mud sample was separated into three different size fractions (RM I, RM II, RM III) of varying densities (1.5-2.2 g cm(-3)). Carbonation of each fraction of red mud was carried out separately at room temperature using a stainless steel reaction chamber at a fixed pressure of 3.5 bar. Effects of reaction time (0.5-12 h) and liquid to solid ratio (0.2-0.6) were studied for carbonation of red mud. Different instrumental techniques such as X-ray diffraction, FTIR and scanning electron microscope (SEM) were used to ascertain the different mineral phases before and after carbonation of each fraction of red mud. Characterization studies revealed the presence of boehmite, cancrinite, chantalite, hematite, gibbsite, anatase, rutile and quartz. Calcium bearing mineral phases (cancrinite and chantalite) were found responsible for carbonation of red mud. Maximum carbonation was observed for the fraction RM II having higher concentration of cancrinite. The carbonation capacity is evaluated to be 5.3 g of CO(2)/100 g of RM II. PMID:20036053

  5. Carbon sinks in temperate forests

    NARCIS (Netherlands)

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

    2001-01-01

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

  6. Carbon Monoxide (CO) Poisoning Prevention

    Science.gov (United States)

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

  7. Dewatering Peat With Activated Carbon

    Science.gov (United States)

    Rohatgi, N. K.

    1984-01-01

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

  8. ROE Carbon Storage - Percent Change

    Data.gov (United States)

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

  9. Microbial Carbon Pump ---A New Mechanism for Long-Term Carbon Storage in the Global Ocean (Invited)

    Science.gov (United States)

    Jiao, N.; Azam, F.; McP Working Group; Scor Wg134

    2010-12-01

    to a recalcitrant carbon reservoir, pumping organic carbon from low concentrations of labile DOM to high concentrations of recalcitrant DOM, building up a huge reservoir for carbon storage over time. Meanwhile the MCP transfers more carbon relative to nitrogen and phosphorus from the reactive organic matter pool into recalcitrant organic matter pool. Compared with the solubility pump, an abiotic mechanism for carbon storage in the ocean which has ocean acidification impacts on marine organisms and biogeochemical cycles, the MCP-driven recalcitrant DOM carbon storage does not appreciably alter the buffering capacity of seawater and has no known negative impact on marine organisms. Furthermore, in the ocean warming scenario, the partitioning of biogenic carbon flow will change, with the flow to POM diminishing and that to DOM increasing, and thus the role of the MCP in carbon storage will most likely enhanced. A working group joined by 26 scientists from 12 countries has been formed under the Scientific Committee for Oceanic Research (SCOR-WG134) to address this multi-faceted biogeochemical issue related to carbon cycling in the ocean and global climate changes.

  10. Electrospun carbon nanofibers reinforced 3D porous carbon polyhedra network derived from metal-organic frameworks for capacitive deionization.

    Science.gov (United States)

    Liu, Yong; Ma, Jiaqi; Lu, Ting; Pan, Likun

    2016-01-01

    Carbon nanofibers reinforced 3D porous carbon polyhedra network (e-CNF-PCP) was prepared through electrospinning and subsequent thermal treatment. The morphology, structure and electrochemical performance of the e-CNF-PCP were characterized using scanning electron microscopy, Raman spectra, nitrogen adsorption-desorption, cyclic voltammetry and electrochemical impedance spectroscopy, and their electrosorption performance in NaCl solution was studied. The results show that the e-CNF-PCP exhibits a high electrosorption capacity of 16.98 mg g(-1) at 1.2 V in 500 mg l(-1) NaCl solution, which shows great improvement compared with those of electrospun carbon nanofibers and porous carbon polyhedra. The e-CNF-PCP should be a very promising candidate as electrode material for CDI applications. PMID:27608826

  11. Electrospun carbon nanofibers reinforced 3D porous carbon polyhedra network derived from metal-organic frameworks for capacitive deionization

    Science.gov (United States)

    Liu, Yong; Ma, Jiaqi; Lu, Ting; Pan, Likun

    2016-01-01

    Carbon nanofibers reinforced 3D porous carbon polyhedra network (e-CNF-PCP) was prepared through electrospinning and subsequent thermal treatment. The morphology, structure and electrochemical performance of the e-CNF-PCP were characterized using scanning electron microscopy, Raman spectra, nitrogen adsorption-desorption, cyclic voltammetry and electrochemical impedance spectroscopy, and their electrosorption performance in NaCl solution was studied. The results show that the e-CNF-PCP exhibits a high electrosorption capacity of 16.98 mg g−1 at 1.2 V in 500 mg l−1 NaCl solution, which shows great improvement compared with those of electrospun carbon nanofibers and porous carbon polyhedra. The e-CNF-PCP should be a very promising candidate as electrode material for CDI applications. PMID:27608826

  12. Bioavailability of vitamin B12

    Science.gov (United States)

    Vitamin B12 deficiency is common in people of all ages who consume a low intake of animal-source foods, including populations in developing countries. It is also prevalent among the elderly, even in wealthier countries, due to their malabsorption of B12 from food. Several methods have been applied t...

  13. Neutral Atomic Carbon in Centers of Galaxies

    OpenAIRE

    Israel, F.P.; Baas, F

    2001-01-01

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

  14. Carbon disulphide promotes sprouting of potato minitubers

    OpenAIRE

    Salimi, Kh.; Hosseini, M.B.; Struik, P.C.; Tavakkol Afshari, R.

    2010-01-01

    We investigated the effects of postharvest application of carbon disulphide (CS2) in various concentrations (0, 15, 25, 35, 45 and 55 ml m-3) and with different exposure duration (24, 48, 72 and 96 h) on breaking of dormancy and sprouting of potato (Solanum tuberosum L., cv. Marfona) minitubers of two ages (freshly harvested and one week after harvest) and two weight classes (1.5 and 12 g). In comparison with the control minitubers, CS2 treated minitubers showed significantly shorter dormancy...

  15. Boron nitride converted carbon fiber

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-04-05

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

  16. Templated Growth of Carbon Nanotubes

    Science.gov (United States)

    Siochik Emilie J. (Inventor)

    2007-01-01

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

  17. Carbon balance in Mediterranean ecosystems

    OpenAIRE

    Correia, Alexandra Cristina Pires

    2013-01-01

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

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

    Science.gov (United States)

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

    2015-10-20

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

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

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

    2008-01-01

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

  1. Wool Research Makes Carbon Headway

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

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

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

    OpenAIRE

    Tsuji, Yasushi; Fujihara, Tetsuaki

    2012-01-01

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

  3. Carbon nanotube junctions and devices

    NARCIS (Netherlands)

    Postma, H.W.Ch.

    2001-01-01

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

  4. Guideposts for Low Carbon Finance

    International Nuclear Information System (INIS)

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

  5. CARBON IN FORESTS: QUALITY MATTERS

    Science.gov (United States)

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

  6. Carbon Sequestration in Agricultural Soils

    OpenAIRE

    World Bank

    2009-01-01

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

  7. Low Carbon Development of Hainan

    Science.gov (United States)

    Yi, Feng; Kun, Zhang

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

  8. Synthesis of (9Z, 12E-, (9E, 12Z-[1-14C]-linoleic acid, (9Z, 12Z, 15E-, (9E, 12Z, 15Z-[1-14C]-linolenic acid and (5Z, 8Z, 11Z, 14E-[1-14C]-arachidonic acid

    Directory of Open Access Journals (Sweden)

    Enard, Thierry

    1996-04-01

    Full Text Available Trans polyunsaturated fatty acids are produced in vegetable oils during heat treatment (240-250 °C.ln order to study the metabolic pathway of 9c, 12t and 9t, 12c linoleic acid and 9c, 12c, 15t and 9t, 12c, 15c linolenic acid, these products were prepared labelled with carbon 14 in the carboxylic position. 5c, 8c, 11c, 14t-Arachidonic acid was also labelled on the carboxylic position with carbon 14 in order to study its physiological effects. To introduce the labelling (E-bromo precursors with a 17 carbons chain or a 19 carbon chain were needed. The different syntheses were done by elongation steps and creation of cis double bonds via highly stereospecific Wittig reactions. The radioactive carbon atom was introduced from [14C]-potassium cyanide. The final radioactive fatty acids had a specific activity greater than 50 mCi/mmol and a radioactive purity better than 99 % for linoleic and linolenic and better than 98.6 % for arachidonic acid.

  9. Full Factorial Experimental Design Analysis of Reactive Dye Removal by Carbon Adsorption

    OpenAIRE

    Özbay, N.; A. Ş. Yargıç; Yarbay-Şahin, R. Z.; E. Önal

    2013-01-01

    The objective of this study was to investigate the removal of Remazol Yellow dye from aqueous solutions by adsorption on activated carbon prepared by chemical activation of sunflower seed cake. It was found that the carbon content of biomass increases up to 65.12% after activation and carbonization processes. The maximum percentage dye removal was obtained as 82.12% with 0.4 g/50 mL adsorbent dosage at 313 K. The Langmuir model showed the best fit with equilibrium isotherm data. The interacti...

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

    Science.gov (United States)

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

    2013-01-01

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

  11. Carbon dioxide conversion over carbon-based nanocatalysts.

    Science.gov (United States)

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

    2013-07-01

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

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

    Science.gov (United States)

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

    2009-01-01

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

  13. Biosphere structure, carbon sequestering potential and the atmospheric C-14 carbon record

    Energy Technology Data Exchange (ETDEWEB)

    Goudriaan, J.

    1992-08-01

    The behaviour of a numerical model for the global carbon cycle is elucidated by a simple analytical model for the biosphere. In the period 1980-1990 the ocean is estimated to have absorbed 33% of the total CO{sub 2} emission to the atmosphere in that same period. Net deforestation was responsible for 12-17% of this total emission rate, whereas the CO{sub 2}-fertilization effect caused a re-absorption of 20-25%. Aggregation of the above-ground biosphere into a single pool in the model caused an overestimation of the CO{sub 2}-fertilization effect. Also, the estimate of this rate increased when the fraction of carbon assumed to remain after the transformation of litter into humus was increased, but the rate was little influenced by the model structure for soil organic carbon. A larger estimate for carbon uptake in the biosphere (Tans, Fung, and Takahashi, 1990) must be compensated by a reduced uptake in the ocean to arrive at a carbon balance. To do this, either the exchange rate between the upper mixed ocean layer and deep sea, or between ocean surface and atmosphere, should be reduced. In addition, a good match to the observed time-course of C-14 carbon in the atmosphere must be preserved by the model. The C-14 time-course did not remain well-matched if the atmosphere-ocean surface exchange was reduced, but it was hardly disturbed at all if the exchange rate with the deep sea was reduced.

  14. Fusion, resonances and scattering in 12C+12C reaction

    Indian Academy of Sciences (India)

    B Sahu; S K Agarwalla; C S Shastry

    2003-07-01

    The variation of fusion cross-section (fus) with energy in the 12C+12C collision is linked to the underlying resonance phenomenon through the behavior of reaction cross-section (r) of which fus is taken as a part. The calculation of fus is done through an energy-dependent imaginary potential in the optical model potential (OMP). Through dispersion relation, such an imaginary potential gives rise to energy-dependent real potential which is incorporated in the OMP. In our calculation, a form of potential for the nuclear part which has a soft repulsive in-built core is introduced based on similar works done earlier. The calculated results of fus are used to explain the oscillatory structure, astrophysical -factor and the decreasing trend at higher energies of the experimental fus data in the case of 12C+12C system with remarkable success. The potential used for fusion calculation is tested for fitting elastic scattering data at some energies and is found good in forward angles. Further improvement of the fitting of these data is obtained by incorporating a coupling potential in the surface region. About twenty resonances are observed in our calculation in the specific partial waves and some of them are found close to the experimentally identified resonances in 12C+12C reaction. Thus, we provide an integrated and comprehensive analysis of fusion, resonance and scattering data in the best studied case of 12C+12C reaction within the framework of optical potential model.

  15. A nova re-accretion model for J-type carbon stars

    OpenAIRE

    S. Sengupta; Izzard, R.G.; Lau, H. H. B.

    2013-01-01

    The J-type carbon (J)-stars constitute 10-15% of the observed carbon stars in both our Galaxy and the Large Magellanic Cloud (LMC). They are characterized by strong 13C absorption bands with low 12C/13C ratios along with other chemical signatures peculiar for typical carbon stars, e.g. a lack of s-process enhancement. Most of the J-stars are dimmer than the N-type carbon stars some of which, by hot-bottom burning, make 13C only in a narrow range of masses. We investigate a binary-star formati...

  16. Microfabricated electroactive carbon nanotube actuators

    Science.gov (United States)

    Ahluwalia, Arti; Baughman, Ray H.; De Rossi, Danilo; Mazzoldi, Alberto; Tesconi, Mario; Tognetti, Alessandro; Vozzi, Giovanni

    2001-07-01

    A variety of microfabrication techniques have been developed at the University of Pisa. They are based either on pressure or piston actuated microsyringes or modified ink-jet printers. This work present the results of a study aimed at fabricating carbon nanotube (NT) actuators using micro-syringes. In order to prevent the nanotubes from aggregating into clumps, they were enclosed in a partially cross-linked polyvinylalcohol - polyallylamine matrix. After sonication the solution remained homogenously dispersed for about 40 minutes, which was sufficient time for deposition. Small strips of NT, about 5 mm across and 15 mm long were deposited. Following deposition, the films were baked at 80 degree(s)C and their thickness, impedance and mechanical resistance measured. The results indicate that 50 minutes of baking time is sufficient to give a constant resistivity of 1.12 x 10-2 (Omega) m per layer similar to a typical semiconductor, and each layer has a thickness of about 6 micrometers .

  17. Carbon isotope fractionation in protoplanetary disks

    CERN Document Server

    Woods, Paul M

    2008-01-01

    We investigate the gas-phase and grain-surface chemistry in the inner 30 AU of a typical protoplanetary disk using a new model which calculates the gas temperature by solving the gas heating and cooling balance and which has an improved treatment of the UV radiation field. We discuss inner-disk chemistry in general, obtaining excellent agreement with recent observations which have probed the material in the inner regions of protoplanetary disks. We also apply our model to study the isotopic fractionation of carbon. Results show that the fractionation ratio, 12C/13C, of the system varies with radius and height in the disk. Different behaviour is seen in the fractionation of different species. We compare our results with 12C/13C ratios in the Solar System comets, and find a stark contrast, indicative of reprocessing.

  18. Making use of surplus biological sludge from waste water treatment plants by transforming it into active carbon; Valoracion de fangos biologicos excedentes de EDARs por transformacion en carbon activo

    Energy Technology Data Exchange (ETDEWEB)

    Martin Sanchez, M. J.; Balaguer Condom, M. D.; Rigola Lapena, M. [Universitat de Girona (Spain)

    1999-05-01

    As an alternative to classical sludge disposal methods, its transformation to activated carbon by chemical activation has been investigated. The objective of this study was to evaluate the characteristics of an activated carbon obtained from biological sludge and to compare these properties with those of commercially available activated carbons in terms of established characterisation parameters and with respect to their removal efficiency for several dyes and heavy metals chosen. The results demonstrated sludge-based activated carbon had a removal efficiency for heavy metals and dyes superior to that of commercially available activated carbons although it is rated inferior according to standardised parameters such as specific surface area. (Author) 12 refs.

  19. Carbon dioxide dangers demonstration model

    Science.gov (United States)

    Venezky, Dina; Wessells, Stephen

    2010-01-01

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

  20. Thermal Influence of CNT on the Polyamide 12 Nanocomposite for Selective Laser Sintering

    Directory of Open Access Journals (Sweden)

    Jiaming Bai

    2015-10-01

    Full Text Available The thermal influence of carbon nanotubes (CNTs on the PA12 in the laser sintering process was assessed by physical experiments and a three dimensional simulation model. It appears that, by adding the CNTs into the PA12 matrix, the thermal conductivity increased. A double ellipsoidal heat flux model was applied to input a three dimensional, continuous moving, volumetric laser heat source. The predicted three dimensional temperature distributions suggested that the laser heat was conducted wider and deeper in the PA12-CNT sample than PA12. Greater heat conduction can reduce the interspace between two successive layers, and result in the increase of the parts’ density and properties.