WorldWideScience

Sample records for carbon 12

  1. Tests of carbon targets for 12C+12C reactions at astrophysical energies

    International Nuclear Information System (INIS)

    As a preliminary step towards measurements of the 12C +12 C reactions at astrophysical energies, we investigate the behaviour of targets under beam bombardment, specifically the quantitative relation between hydrogen and deuterium content of different carbon targets and target temperature. Experiments have taken place at the CIRCE accelerator in Caserta, Italy and preliminary results are presented here

  2. 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.

  3. 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.

  4. 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

  5. Measurement of carbon-13:carbon-12 ratios by Fourier transform infrared spectrometry

    International Nuclear Information System (INIS)

    An approach to the measurement of 13C:12C ratios in isotopically enriched samples is described. The carbon in samples is converted into CO2 gas by either combustion of organic material or acidification of carbonate. The gas is then measured by FTIR spectrometry. When spectra are recorded at 0.25 cm-1 resolution the magnitude of the isotopic shift is such that the areas of 12C and 13C rotational lines of the ν3 vibrational band for CO2 can be measured and the isotopic composition determined by reference to a standard calibration graph. The relative standard deviation at natural abundance is 1.2%, which gives an absolute limit of detection of 0.026 atom-% 13C. Details of the decomposition procedures and a comparison of the results with those obtained by mass spectrometry are also presented. (author)

  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. 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.

  10. 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

  11. Comparison of infrared and mass-spectrometric measurements of carbon-13/carbon-12 ratios

    International Nuclear Information System (INIS)

    The delta13C values of 20 breath samples and 10 tank-CO2 samples (delta13C values ranged from -31.3 to +148.9per mille vs PDB) and the CO2 concentrations of three breath samples and 10 tank-CO2 samples were measured with a commercial prototype of a diode-laser i.r. spectrophotometer, MAT I. The results were compared with those obtained by gas-isotope-ratio mass spectrometry and by gas chromatography. Precisions (ssub(x), n=10) of 0.2per mille and 0.6% were calculated for 13C/12C ratios and CO2 concentrations, respectively, using the MAT I system. (author)

  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. Synthesis of functionalized poly(ester carbonate) with laminin-derived peptide for promoting neurite outgrowth of PC12 cells.

    Science.gov (United States)

    Xing, Dongming; Ma, Lie; Gao, Changyou

    2014-10-01

    Maleimide-functionalized poly(ester carbonate)s are synthesized by ring-opening copolymerization of furan-maleimide functionalized trimethylene carbonate (FMTMC) with L-lactide and a subsequent retro Diels-Alder reaction. The maleimide groups on poly(ester carbonate)s are amenable to Michael addition with thiol-containing molecules such as 3-mercapto-1-propanol, 2-aminoethanethiol hydrochloride, and mercaptoacetic acid under mild conditions, enabling the formation of biodegradable materials with various functional groups (e.g., hydroxyl, amine, and carboxyl). In particular, the maleimide-functionalized poly(ester carbonate) is clicked with a laminin-derived peptide CQAASIKVAV. In vitro culture of PC12 cells shows that the maleimide-functionalized polymers, especially the CQAASIKVAV-grafted one, could support cell proliferation and neurite outgrowth. The maleimide-functionalized poly(ester carbonate)s provide a versatile platform for diverse functionalization and have comprehensive potential in biomedical engineering. PMID:24962245

  17. Carbon isotope (14C, 12C) measurements to quantify sources of atmospheric carbon monoxide in urban air

    International Nuclear Information System (INIS)

    Atmospheric air samples were collected during the Winter of 1989-90 in Albuquerque, NM USA, for carbon isotope (14C, 12C) analysis of carbon monoxide (CO). An experimental sample design was prepared to target periods when the concentration of CO exceeds the 9 μL/L (volume fraction), 8 hour National Ambient Air Quality Standard (NAAQS) and during periods of attainment. Sampling sites, time of day, sampling duration, and meteorology were carefully considered so that source impacts be optimal. A balanced sampling factorial design was used to yield maximum information from the constraints imposed; the number of samples was limited by the number of sample canisters available, time, and resources. Carbon isotope measurements of urban air, ''clean-air'' background from Niwot Ridge, Colorado, average (wood) logs and oxygenated-gasolines were used in a 3-source model to calculate the contribution of woodburning to the total atmospheric CO burden in Albuquerque. Results show that the estimated fractional contribution of residential wood combustion (Θ' RWC) ranged from 0 to 0.30 of CO concentrations corrected for ''clean-air'' background. For these same samples, the respective CO concentrations attributed to woodburning range from 0 to 0.90 μmol/mol (mole fraction), well below the NAAQS. In all cases, fossil CO is the predominant source of ambient CO concentrations ranging from 0.96 to 6.34 μmol/mol. A final comment is made on the potential of fossil CO measurements as an indirect tracer of atmospheric benzene, relevant to exposure risk estimates of motor vehicle emissions and occupational health and safety standards. (author). 26 refs, 3 figs, 4 tabs

  18. 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

  19. The use of a hydrogen signal in correcting the carbon concentration from 12C(n,n'γ)12C reaction in coal

    International Nuclear Information System (INIS)

    An attempt to use the 2.22 MeV H neutron capture γ-ray as the correcting signal for carbon content measurements is presented. The influence of changes in moisture content on the intensity of 4.43 MeV carbon γ-ray from the 12C(n,n'γ)12C reaction was investigated theoretically using the ANISN multigroup one-dimensional discrete ordinates transport code and the BUGLE-80 (DLC-75) neutron data library, and experimentally by measuring the 4.43 MeV carbon and 2.22 MeV hydrogen γ-ray intensities from a coal sample with added water up to ∼ 23 wt%. A correction formula for carbon γ-ray intensities was arrived at for Janina 118 coal samples using the 2.22 MeV hydrogen γ-ray signal. Further search for a universal formula and error analysis is being undertaken. (author)

  20. 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.

  1. Investigation of carbon-coated lithiated Li4+xTi5O12/C for lithium-ion batteries

    International Nuclear Information System (INIS)

    Highlights: • Lithiated Li4+xTi5O12/C with pre-stored active Li ions has been synthesized. • The first-cycle coulombic efficiency of Li4+xTi5O12/C is over 100%. • Li4+xTi5O12/C displays excellent cyclic stability and capacity retention. • TiO2 nanoparticles and carbon coating are necessary for formation of Li4+xTi5O12/C. - Abstract: Carbon-coated Li4Ti5O12 and lithiated Li4+xTi5O12 anode materials have been synthesized using nanosized anatase TiO2 and commercial TiO2 with mixed structure as Ti sources, respectively. Microstructural investigation indicates that Li4Ti5O12 and Li4+xTi5O12 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 Li4+xTi5O12 lattice during solid-state synthesis, resulting in its first-cycle coulombic efficiency over 100%. Further, Li4+xTi5O12/C exhibits higher cyclic capacities than Li4Ti5O12/C at different current density. The reversible charge capacity retention of Li4+xTi5O12/C reaches 98.5% after 100 cycles, which indicates that Li4+xTi5O12/C is promising candidate anode material for long lifetime lithium-ion batteries. The formation mechanism of Li4+xTi5O12/C has been discussed, in which the nanosized anatase TiO2 with high chemical activity and the carbon coating play key roles for the formation of Li4+xTi5O12/C

  2. 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

  3. 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...

  4. 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.

  5. 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.

  6. Carbon coated Li4Ti5O12 nanorods as superior anode material for high rate lithium ion batteries

    International Nuclear Information System (INIS)

    Highlights: •A novel approach has been developed to fabricate 1D Li4Ti5O12/C nanorods by a wet-chemical route. •Carbon coating layer effectively restrict the particle growth and enhance electronic conductivity. •The Li4Ti5O12/C nanorods exhibit remarkable rate capability and long cycle life. -- Abstract: We describe a novel approach for the synthesis of carbon coated Li4Ti5O12 (Li4Ti5O12/C) nanorods for high rate lithium ion batteries. The carbon coated TiO2 nanotubes using the glucose as carbon source are first synthesized by hydrothermal treatment. The commercial anatase TiO2 powder is immersed in KOH sulotion and subsequently transforms into Li4Ti5O12/C in LiOH solution under hydrothermal condition. Field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, nitrogen adsorption/desorption and Raman spectra are performed to characterize their morphologies and structures. Compared with the pristine Li4Ti5O12, one-dimensional (1D) Li4Ti5O12/C nanostructures show much better rate capability and cycling stability. The 1D Li4Ti5O12/C architectures effectively restrict the particle growth and enhance their electronic conductivity, enabling fast ion and electron transport

  7. 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.

  8. Light-dark (12:12) cycle of carbon and nitrogen metabolism in Crocosphaera watsonii WH8501: relation to the cell cycle.

    Science.gov (United States)

    Dron, Anthony; Rabouille, Sophie; Claquin, Pascal; Le Roy, Bertrand; Talec, Amélie; Sciandra, Antoine

    2012-04-01

    This study provides with original data sets on the physiology of the unicellular diazotrophic cyanobacterium Crocosphaera watsonii WH8501, maintained in continuous culture in conditions of obligate diazotrophy. Cultures were exposed to a 12:12 light-dark regime, representative of what they experience in nature and where growth is expected to be balanced. Nitrogen and carbon metabolism were monitored at high frequency and their dynamics was compared with the cell cycle. Results reveal a daily cycle in the physiological and biochemical parameters, tightly constrained by the timely decoupled processes of N(2) fixation and carbon acquisition. The cell division rate increased concomitantly to carbon accumulation and peaked 6 h into the light. The carbon content reached a maximum at the end of the light phase. N(2) fixation occurred mostly during the dark period and peaked between 9 and 10 h into the night, while DNA synthesis, reflected by DNA fluorescence, increased until the end of the night. Consequently, cells in G1- and S-phases present a marked decrease in their C:N ratio. Nitrogen acquisition through N(2) fixation exceeded 1.3- to 3-fold the nitrogen requirements for growth, suggesting that important amounts of nitrogen are excreted even under conditions supposed to favour balanced, carbon and nitrogen acquisitions. PMID:22188053

  9. Li4Ti5O12/C composite electrode material synthesized involving conductive carbon precursor for Li-ion battery

    International Nuclear Information System (INIS)

    Li4Ti5O12/C composite was synthesized via a simple solid-state reaction using Super-P-Li conductive carbon black as reaction precursor. The prepared samples were characterized by XRD, SEM, TG and granularity analysis and their electrochemical performance was also investigated in this work. The results showed that the Li4Ti5O12/C composite had a spinel crystal structure and the particle size of the powder was uniformly distributed with an average particle size of 480 nm. The conductive carbon was embedded in the Li4Ti5O12 particles without incorporation in the Li4Ti5O12 crystal lattice during the sintering process. The added Super-P-Li carbon played an important role in improving the electronic conductivity and electrochemical performance of the Li4Ti5O12/C electrode. Compared with raw Li4Ti5O12, the Li4Ti5O12/C composite exhibited higher rate capability and excellent reversibility. The initial discharge capacity of Li4Ti5O12/C composite was 174.5 mAh g-1 at 0.5C and 169.3 mAh g-1 at 1C.

  10. Carbon Leakage in the Primary Aluminium Sector: What evidence after 6 1/2 years of the EU ETS? - Working Paper No. 2012-12

    International Nuclear Information System (INIS)

    This paper provides an econometric analysis of the evidence of carbon leakage from the European primary aluminium industry during the first 6 1/2 years of the EU ETS. The findings suggest that while rising electricity prices have played a critical role in reducing the competitiveness of EU primary aluminium smelting in recent years, no evidence of carbon leakage can be detected so far. Other factors, including rising primary energy prices and changes in EU competition law regarding long term contracts, appear to be more important factors explaining the rise in net imports of primary aluminium and the gradual closure of a number of European primary smelters during the past 6 1/2 years. Our results suggest that the carbon leakage debate in this sector may therefore be better seen in terms of not accelerating the decline of the industry in Europe, rather than preventing it, and that any state-aid to the industry to prevent carbon leakage should therefore be applied accordingly. (author)

  11. 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

  12. Use of laser spectroscopy to measure the 13C/12C and 18O/16O compositions of carbonate minerals.

    Science.gov (United States)

    Barker, Shaun L L; Dipple, Gregory M; Dong, Feng; Baer, Douglas S

    2011-03-15

    The stable carbon and oxygen isotope compositions of carbonate minerals are utilized throughout the earth and environmental sciences for various purposes. Here, we demonstrate the first application of a prototype instrument, based on off-axis integrated cavity output laser spectroscopy, to measure the carbon and oxygen isotope composition of CO(2) gas evolved from the acidification of carbonate minerals. The carbon and oxygen isotope ratios were recorded from absorption spectra of (12)C(16)O(16)O, (13)C(16)O(16)O, and (12)C(16)O(18)O in the near-infrared wavelength region. The instrument was calibrated using CaCO(3) minerals with known δ(13)C(VPDB) and δ(18)O(VSMOW) values, which had been previously calibrated by isotope ratio mass spectrometry relative to the international isotopic standards NBS 18 and NBS 19. Individual analyses are demonstrated to have internal precision (1 SE) of better than 0.15‰ for δ(13)C and 0.6‰ for δ(18)O. Analysis of four carbonate standards of known isotopic composition over 2 months, determined using the original instrumental calibration, indicates that analyses are accurate to better than 0.5‰ for both δ(13)C and δ(18)O without application of standard-sample-standard corrections. PMID:21341717

  13. 78 FR 41366 - Certain Large Diameter Carbon and Alloy Seamless Standard, Line, and Pressure Pipe (Over 4 1/2

    Science.gov (United States)

    2013-07-10

    ...The Department of Commerce (the Department) is conducting an administrative review of the antidumping duty order on certain large diameter carbon and alloy seamless standard, line, and pressure pipe (over 4 \\1/2\\ inches) (large diameter seamless pipe) from Japan. The period of review (POR) is June 1, 2011, through May 31, 2012. This review covers five producers/exporters of subject......

  14. 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...

  15. 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.

  16. 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

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Fuel economy and carbon-related... ECONOMY AND CARBON-RELATED EXHAUST EMISSIONS OF MOTOR VEHICLES Fuel Economy Regulations for 1978 and Later Model Year Automobiles-Test Procedures § 600.113-12 Fuel economy and carbon-related exhaust...

  17. 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.

  18. 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, ...

  19. 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...

  20. 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...

  1. Spray drying of spherical Li4Ti5O12/C powders using polyvinyl pyrrolidone as binder and carbon source

    International Nuclear Information System (INIS)

    Highlights: • The spherical Li4Ti5O12/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. • Li4Ti5O12/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 Li4Ti5O12/C granules by spray drying. The effects of PVP content and atmospheres on the properties of Li4Ti5O12 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

  2. 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.

  3. 13C/12C and 18O/16O in calcium carbonate-cemented beach sands ('beach rocks')

    International Nuclear Information System (INIS)

    A study of the stable isotope composition (C13/C12 and O18/O16) of the cement and the local groundwater in Itaparica Island (Salvador-Brazil) is carried out to determine the origin of the carbonate cement. For area A, the cement has Δ13C = 9% showing that CO2 in groundwater charged by decay of organic material is the source of carbonate in the cement. Probably comentation occurs during loss of excess CO2 from groundwater as comes into an environment where loss of CO2 is possible . In area B, where the cements contain, on the average Δ18O v=1,3%, the cement is formed from carbonate typical of sea water or a mixture of sea water and fresh water. (Autor)

  4. Trends of 13C/12C ratios in pinyon tree rings of the American Southwest and the global carbon cycle

    International Nuclear Information System (INIS)

    An accurate atmospheric 13C/12C chronology can provide important constraints to models of the global carbon cycle. Trees accumulate carbon from atmospheric CO2 into growth rings and offer potential for 13C/12C reconstructions, but results have not been reproducible. This paper presents δ13C curves from 5 sites, representing 20 pinyon (Pinus edulis) trees, where cores of 4 trees from each site have been pooled into a composite sample. Isotopic analysis of cellulose in 5-yr ring groups produces curves with a general trend of decreasing δ13C after 1800, but with pronounced short-term fluctuations superimposed upon the trend. Evidence indicates the fluctuations are strongly related to moisture availability (drought). A mean curve of the 5 δ13C chronologies from which the fossil-fuel component is subtracted suggests a substantial biospheric CO2 contribution to the atmosphere since 1800

  5. 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

  6. 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...

  7. 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.

  8. 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...

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

    Science.gov (United States)

    Reddy, Gudigopuram B; Raczkowski, Charles W; Cyrus, Johnsely S; Szogi, Ariel

    2016-01-01

    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 a marsh-pond-marsh design wetland system. The functionality of this system was highly dependent on soil carbon content and organic matter turnover rate. To better understand system performance and carbon dynamics, we measured plant dry matter, decomposition rates and soil carbon fractions. Plant litter decomposition rate was 0.0052 g day(-1) (±0.00119 g day(-1)) with an estimated half-life of 133 days. The detritus layer accumulated over the soil surface had much more humin than other C fractions. In marsh areas, soil C extracted with NaOH had four to six times higher amounts of humic acid, fulvic acid and humin than soil C extracted by cold and hot water, HCl/HF, and Na pyruvate. In the pond area, humic acid, fulvic acid and humin content were two to four times lower than in the marsh area. More soil C and N was found in the marsh area than in the pond area. These wetlands proved to be large sinks for stable C forms. PMID:27191573

  10. Residual stresses and mechanical properties of amorphous carbon films on 40 CAD 6-12 plasma nitrided steel

    International Nuclear Information System (INIS)

    Full text.An investigation has been carried out to study the effect of deposition time and benzene flow rate on residual stresses level, morphological, hardness, adhesion strength and friction coefficient of carbon films. Amorphous hydrogenated carbon a-c:H films were deposited on plasma nitrided layers (ε+γ') of 40 CAD 6-12 steel substrate using Microwave Electron Cyclotron Resonance Plasma Assisted Chemical Vapour Deposition nethod with benzene/Argon gas as precursor. The coatings have been deposited at different temperatures 350 and 520 degree celsius for times 3,5,60 and 120 minutes under different pressures ranging from 10-3 to 10-5 mbar. A wide range of thickness values of the amorphous carbon layers (0.4 up 15 μm) was formed as function of the deposition conditions and precursors, when the bias voltage (-200V) and microwave power (300 W) were kept constant. Stress behavior in carbon films has been investigated by x-ray diffraction measurement using the sin2Ψ technique. The type and the value of stress have shown a strong dependence of film thickness and the benzene flow rate (σ= -259 ÷ 5 MPa). Scratch tests revealed that they possess excellent adhesion strength and exhibit both low values of friction coefficient and roughness. The has been concluded than the micro hardness measurements results are not influenced by the coating thickness. The hardness of the coatings is normally below 30 GPa for coatings with 7 sccm of benzene flow rate. The carbon films were characterized by SEM and Raman spectroscopy

  11. 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.

  12. One-Carbon Metabolism–Genome Interactions in Folate-Associated Pathologies12

    OpenAIRE

    Stover, Patrick J.

    2009-01-01

    Impairments in folate-mediated 1-carbon metabolism are associated with several common diseases and developmental anomalies including intestinal cancers, vascular disease, cognitive decline, and neural tube defects. The etiology of folate-associated pathologies involves interactions among multiple genetic risk alleles and environmental factors, although the causal mechanisms that define the role of folate and other B-vitamins in these complex disorders remain to be established. Folate and othe...

  13. 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...

  14. Controlling the apex angle of carbon cone induced by 1.2 keV argon ions at room temperature

    International Nuclear Information System (INIS)

    Carbon nanofiber-tipped-cones with controllable apex angle were fabricated by sputtering graphite with 1.2keV Ar+ ions in different incident angles at room temperature. The density of carbon cones was estimated at 1 x 109- 1 x 1010/cm2. The cones with carbon nanofiber were oriented to the ion-beam direction. By increasing the incidence from 30 degree to 60 degree, the apex angle of cones decreased from 33 degree to 20 degree, and the aspect ratio increased from 250nm/150nm to 1200nm/400nm. The decreased apex angle, and the increased aspect ratio and density of the cones, were attributed to decreasing effective diffuse coefficient induced by the ion beam and increasing sputtering yield. By increasing the current density from 200 μA/cm2 to 800 μA/cm2, the apex angle of cones decreased from 90 degree to 20 degree and the height of cones increased from 100nm to 1200nm. The increased dose rate caused by larger current densities of the ion beam should result in the different number of the sputtered atom or cluster, which was considered as reason of the decrement of the apex angle and the increment of the height of cones. (authors)

  15. 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

  16. 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

  17. Interaction of single and multi wall carbon nanotubes with the biological systems: tau protein and PC12 cells as targets.

    Science.gov (United States)

    Zeinabad, Hojjat Alizadeh; Zarrabian, Alireza; Saboury, Ali Akbar; Alizadeh, Ali Mohammad; Falahati, Mojtaba

    2016-01-01

    Subtle changes in the structure of nanoparticles influence their surface tension and corresponding interaction with cells and proteins. Here, the interaction of the single wall carbon nanotube (SWCNT) and multiwall carbon nanotube (MWCNT) with different surface tension with tau protein was evaluated using a variety of techniques including far and near circular dichroism, fluorescence spectroscopy, dynamic light scattering, Zeta potential, and TEM evaluation. Also the cytotoxicity of SWCNT and MWCNT on the PC12 cell line as a model of nervous system cell line was investigated by the MTT, LDH, acridine orange/ethidium bromide staining, flow cytometry, caspase 3 activity, cell and membrane potential assays. It was observed that SWCNT induced more structural changes of tau protein relative to MWCNT/tau protein interaction. It was also revealed that SWCNT and MWCNT impaired the viability and complexity of PC12 cells in different modes of cytotoxicity. Analysis of cellular outcomes indicated that MWCNT in comparison with SWCNT resulted in induction of necrotic modes of cell death, whereas apoptotic modes of cell death were activated in SWCNT-incubated cells. Together these findings suggest that surface tension may be used to determine how nanoparticle structure affects neurotoxicity and protein conformational changes. PMID:27216374

  18. [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

  19. Interaction of single and multi wall carbon nanotubes with the biological systems: tau protein and PC12 cells as targets

    Science.gov (United States)

    Zeinabad, Hojjat Alizadeh; Zarrabian, Alireza; Saboury, Ali Akbar; Alizadeh, Ali Mohammad; Falahati, Mojtaba

    2016-01-01

    Subtle changes in the structure of nanoparticles influence their surface tension and corresponding interaction with cells and proteins. Here, the interaction of the single wall carbon nanotube (SWCNT) and multiwall carbon nanotube (MWCNT) with different surface tension with tau protein was evaluated using a variety of techniques including far and near circular dichroism, fluorescence spectroscopy, dynamic light scattering, Zeta potential, and TEM evaluation. Also the cytotoxicity of SWCNT and MWCNT on the PC12 cell line as a model of nervous system cell line was investigated by the MTT, LDH, acridine orange/ethidium bromide staining, flow cytometry, caspase 3 activity, cell and membrane potential assays. It was observed that SWCNT induced more structural changes of tau protein relative to MWCNT/tau protein interaction. It was also revealed that SWCNT and MWCNT impaired the viability and complexity of PC12 cells in different modes of cytotoxicity. Analysis of cellular outcomes indicated that MWCNT in comparison with SWCNT resulted in induction of necrotic modes of cell death, whereas apoptotic modes of cell death were activated in SWCNT-incubated cells. Together these findings suggest that surface tension may be used to determine how nanoparticle structure affects neurotoxicity and protein conformational changes. PMID:27216374

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. A particle-hole-rotator coupling model for the giant resonance of carbon-12

    International Nuclear Information System (INIS)

    A collective correlations calculation has been made for the giant resonance of 12C. The low-lying states are treated as members of two rotational bands, and higher energy low-lying states are included in the coupling procedure in an attempt to examine the connection of these states with structure in the 30-35 MeV region, and to examine a proposed rotational band of states built on the 7.65 MeV (0+) level. The calculation fails to transfer strength to the extent expected. (author)

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

    International Nuclear Information System (INIS)

    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 12C by 50 MeV πr± scattering. The cross section ratio of the isoscalar to the isovector states was found to be 6.8 ± 1.3 for π++ scattering and 3.9 ± 1.4 for π- scattering. These ratios give an isospin mixing matrix element H01, of 119 ± 40 key, in good agreement with the average value of 123 ± 26 key deduced from previous pion-scattering data and with values deduced from other probes. The ratio of π+ + p to π- + p cross sections was determined experimentally to be 2.60 ± 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 12C and were generally described well by distorted wave Born approximation calculations published previously

  6. Orbital plasma keyhole welding of 12--13% Cr low carbon martensitic line pipe steels and weld joint corrosion properties

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmeister, H.; Dietrich, S. [Univ. der Bundeswehr Hamburg (Germany); Tystad, M.; Knagenhjelm, H.O.; Andersen, T.R. [Norsk Hydro A/S Porsgrunn (Norway). Forskningssenteret

    1995-10-01

    Based on requirements for more economical pipe laying procedures in the oil and gas industry, the potential of the orbital plasma keyhole process for welding of 12--13% Cr martensitic low carbon steels together with resulting hardness and corrosion properties is investigated. As a result, downhill orbital welding speeds up to 6--7 mm/s at 6--10 mm wall thickness are achieved. For hardness reduction, local postweld heating of 600--700 C at up to 10 min was required. Pitting corrosion resistance of the weld joints was reduced by welding but could be restored by postweld heating above 750--800 C, which, however, might produce hardness levels not satisfying NACE requirements due to formation of untempered martensite.

  7. 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.

  8. 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.

  9. 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

  10. a Study of Fusion-Fission in the ARGON-36 + Carbon -12 System.

    Science.gov (United States)

    Farrar, Kelly Allen, Jr.

    The ^{36}Ar + ^{12}C reaction at E_{lab} = 187.7 MeV has been used to populate the ^{48}Cr system at an excitation energy of 59.6 MeV. Cross sections to the A = 6, 7 and A = 9-24 decay channels have been measured and found to be consistent with fission from a fully-equilibrated compound nucleus. High-resolution mutual-excitation-energy spectra were obtained through a particle-particle coincidence measurement for the {^{14 }Mg} + {^{14}Mg} and {^{20}Ne} + {^{28}Si} exit channels. The peaks observed in these spectra at high energies were found to correspond directly to peaks seen in similar spectra obtained from an earlier measurement using the ^{24}Mg + ^{24}Mg reaction to reach the same ^{48}Cr system at an excitation energy of 59.4 MeV. The mutual excitation spectrum for the ^{24}Mg + ^{24}Mg exit channel was compared with a spectrum obtained from a calculation based on the transition-state model for light nuclei. The experimental and observed spectra were in good agreement suggesting that the observed structure can be explained in terms of a simple statistical decay picture. A particle-particle -gamma measurement was also made and the results were used to study the specific mutual excitations involved in the excitation energy peaks. It was found that the peaks are not dominated by single, mutual excitations. The results overall tend to confirm the conclusion that the source of the structure seen in the mutual-excitation spectrum at high energy is the result of a statistical population of energy levels as determined by the spin-weighting of the available phase space.

  11. 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.

  12. Carbon coated Li{sub 4}Ti{sub 5}O{sub 12} nanorods as superior anode material for high rate lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Hongjun; Shen, Laifa; Rui, Kun; Li, Hongsen; Zhang, Xiaogang, E-mail: azhangxg@nuaa.edu.cn

    2013-09-25

    Highlights: •A novel approach has been developed to fabricate 1D Li{sub 4}Ti{sub 5}O{sub 12}/C nanorods by a wet-chemical route. •Carbon coating layer effectively restrict the particle growth and enhance electronic conductivity. •The Li{sub 4}Ti{sub 5}O{sub 12}/C nanorods exhibit remarkable rate capability and long cycle life. -- Abstract: We describe a novel approach for the synthesis of carbon coated Li{sub 4}Ti{sub 5}O{sub 12} (Li{sub 4}Ti{sub 5}O{sub 12}/C) nanorods for high rate lithium ion batteries. The carbon coated TiO{sub 2} nanotubes using the glucose as carbon source are first synthesized by hydrothermal treatment. The commercial anatase TiO{sub 2} powder is immersed in KOH sulotion and subsequently transforms into Li{sub 4}Ti{sub 5}O{sub 12}/C in LiOH solution under hydrothermal condition. Field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, nitrogen adsorption/desorption and Raman spectra are performed to characterize their morphologies and structures. Compared with the pristine Li{sub 4}Ti{sub 5}O{sub 12}, one-dimensional (1D) Li{sub 4}Ti{sub 5}O{sub 12}/C nanostructures show much better rate capability and cycling stability. The 1D Li{sub 4}Ti{sub 5}O{sub 12}/C architectures effectively restrict the particle growth and enhance their electronic conductivity, enabling fast ion and electron transport.

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

    International Nuclear Information System (INIS)

    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 CO2 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 CO2 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 CO2 and for the composites with amine the amount of amine was that influenced in the adsorption capacity

  14. 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.

  15. 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

  16. Enhanced electrochemical performance of Li{sub 4}Ti{sub 5}O{sub 12} as anode material for lithium-ion batteries with different carbons as support

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Tingting [School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094 (China); Ni, Haifang; Song, Wei-Li [Institute of Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China); Fan, Li-Zhen, E-mail: fanlizhen@ustb.edu.cn [Institute of Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China)

    2015-10-15

    Nano-Li{sub 4}Ti{sub 5}O{sub 12}/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-Li{sub 4}Ti{sub 5}O{sub 12}/carbon composites with various morphologies are formed depending on the carbon matrixes used. The Li{sub 4}Ti{sub 5}O{sub 12} 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{sup −1}, the discharge capacities of nano-Li{sub 4}Ti{sub 5}O{sub 12}/carbon composites with 10 wt% carbon are 138.6, 120.8 and 120.9 mAh g{sup −1} for carbon nanotubes, super-P and porous carbon as the carbon supports, respectively. The nano-Li{sub 4}Ti{sub 5}O{sub 12}/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: • Li{sub 4}Ti{sub 5}O{sub 12}/carbon nanocomposites are designed using different carbons as supports. • Li{sub 4}Ti{sub 5}O{sub 12} particles formed on carbon matrix are fine and homogeneous. • Aggregation and growth of Li{sub 4}Ti{sub 5}O{sub 12} particles are inhibited. • The Li{sub 4}Ti{sub 5}O{sub 12}/carbon nanocomposites exhibit superior electrochemical performance.

  17. Hierarchical carbon-coated acanthosphere-like Li4Ti5O12 microspheres for high-power lithium-ion batteries

    Science.gov (United States)

    Sha, Yujing; Xu, Xiaomin; Li, Li; Cai, Rui; Shao, Zongping

    2016-05-01

    In this work, carbon-coated hierarchical acanthosphere-like Li4Ti5O12 microspheres (denoted as AM-LTO) were prepared via a two-step hydrothermal process with low-cost glucose as the organic carbon source. The hierarchical porous microspheres had open structures with diameters of 4-6 μm, which consisted of a bunch of willow leaf-like nanosheets. Each nanosheet was comprised of Li4Ti5O12 nanoparticles that are 20 nm in size and coated by a thin carbon layer. When applied as the anode material for lithium-ion batteries (LIBs), the AM-LTO presented outstanding rate and cycling performance due to its unique morphologies. A high capacity of 145.6 mAh g-1 was achieved for AM-LTO at a rate of 40C (1C = 175 mAh g-1). In contrast, the sample synthesized without glucose as carbon source (denoted as S-LTO) experienced an obvious structural collapse during the hydrothermal reaction and presented a specific capacity of only 67 mAh g-1 at 1C, which further decreased to 14 mAh g-1 at 40C. Further morphological growth of the acanthosphere-like Li4Ti5O12 microspheres and their excellent performance as an anode in LIBs were also discussed in this work.

  18. 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)

  19. 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...

  20. Glutamine Synthetases GLN1;2 and GLN2 in Relation to Arabidopsis Growth Response to Elevated Atmospheric Carbon Dioxide and Varying Nitrogen Forms

    DEFF Research Database (Denmark)

    Vurrakula, Swathi

    Carbon and nitrogen are the most abundant elements in plants, together making up around 40-50% and 2-6% of dry matter respectively. Elevated atmospheric CO2 levels are predicted to double by the end of this century, increasing carbon fixation by C3 plants like Arabidopsis and, hence, their carbon...... cues and adjusting it to the plant internal status. The two major types of GS include cytosolic GS1 (five isoforms in Arabidopsis, GLN1;1 to GLN1;5) and a single chloroplastic GS2. GS draws its substrates from carbon skeletons to synthesize amino acids. Thus, carbon and nitrogen metabolisms are closely...... nitrogen species (ammonium and nitrate) and availability. Arabidopsis gln1;2 knock-out and gln2 (reduced GS2 activity by 50%) mutants were studied in response to elevated CO2 (800 ppm) when provided with moderate and high levels of ammonium or nitrate alone, or in combination. Elevated CO2 promoted plant...

  1. 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

  2. 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.

  3. Impact of a CXCL12/CXCR4 Antagonist in Bleomycin (BLM) Induced Pulmonary Fibrosis and Carbon Tetrachloride (CCl4) Induced Hepatic Fibrosis in Mice

    Science.gov (United States)

    Chow, Leola N.; Schreiner, Petra; Ng, Betina Y. Y.; Lo, Bernard; Hughes, Michael R.; Scott, R. Wilder; Gusti, Vionarica; Lecour, Samantha; Simonson, Eric; Manisali, Irina; Barta, Ingrid; McNagny, Kelly M.; Crawford, Jason; Webb, Murray; Underhill, T. Michael

    2016-01-01

    Modulation of chemokine CXCL12 and its receptor CXCR4 has been implicated in attenuation of bleomycin (BLM)-induced pulmonary fibrosis and carbon tetrachloride (CCl4)-induced hepatic injury. In pulmonary fibrosis, published reports suggest that collagen production in the injured lung is derived from fibrocytes recruited from the circulation in response to release of pulmonary CXCL12. Conversely, in hepatic fibrosis, resident hepatic stellate cells (HSC), the key cell type in progression of fibrosis, upregulate CXCR4 expression in response to activation. Further, CXCL12 induces HSC proliferation and subsequent production of collagen I. In the current study, we evaluated AMD070, an orally bioavailable inhibitor of CXCL12/CXCR4 in alleviating BLM-induced pulmonary and CCl4-induced hepatic fibrosis in mice. Similar to other CXCR4 antagonists, treatment with AMD070 significantly increased leukocyte mobilization. However, in these two models of fibrosis, AMD070 had a negligible impact on extracellular matrix deposition. Interestingly, our results indicated that CXCL12/CXCR4 signaling has a role in improving mortality associated with BLM induced pulmonary injury, likely through dampening an early inflammatory response and/or vascular leakage. Together, these findings indicate that the CXCL12-CXCR4 signaling axis is not an effective target for reducing fibrosis. PMID:26998906

  4. 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.)

  5. Site-selective covalent functionalization at interior carbon atoms and on the rim of circumtrindene, a C36H12 open geodesic polyarene

    Directory of Open Access Journals (Sweden)

    Hee Yeon Cho

    2014-04-01

    Full Text Available Circumtrindene (6, C36H12, one of the largest open geodesic polyarenes ever reported, exhibits fullerene-like reactivity at its interior carbon atoms, whereas its edge carbons react like those of planar polycyclic aromatic hydrocarbons (PAHs. The Bingel–Hirsch and Prato reactions – two traditional methods for fullerene functionalization – afford derivatives of circumtrindene with one of the interior 6:6 C=C bonds modified. On the other hand, functionalization on the rim of circumtrindene can be achieved by normal electrophilic aromatic substitution, the most common reaction of planar PAHs. This peripheral functionalization has been used to extend the π-system of the polyarene by subsequent coupling reactions and to probe the magnetic environment of the concave/convex space around the hydrocarbon bowl. For both classes of functionalization, computational results are reported to complement the experimental observations.

  6. 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.

  7. 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

  8. 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

  9. 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.

  10. 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 ...

  11. 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.

  12. 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

  13. 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

  14. Charge-state dependence of M-shell x-ray production in 67Ho by 2--12-MeV carbon ions

    International Nuclear Information System (INIS)

    Charge-state dependence of M-shell x-ray production cross sections of 67Ho bombarded by 2--12-MeV carbon ions, with and without K-shell vacancies, were measured using a windowless Si(Li) x-ray detector with a full-width-at-half-maximum resolution of 135 eV at 5.9 keV. Carbon ions of different charge states were produced using a postacceleration, nitrogen gas stripping cell. The carbon ions were then magnetically analyzed to select the desired charge state and energy before entering the target chamber. The total M-shell and Mζ, Mα,β, and Mγ x-ray cross sections were measured. The electron-capture (EC) contributions as well as the direct-ionization (DI) contributions can be determined by making a comprehensive study of the projectile-charge-state dependence of the target x-ray production cross sections for targets in which the single-collision realm is maintained. In this paper, both EC and DI contributions and the total M-shell x-ray production cross sections are compared to both the first Born theory and to the perturbed-stationary-state theory with energy-loss, Coulomb-deflection, and relativistic corrections

  15. 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...

  16. 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.

  17. Corrosion of carbon steel under anaerobic conditions in a repository for SF and HLW in Opalinus Clay. Technical report 08-12

    International Nuclear Information System (INIS)

    Nagra is considering carbon steel as one of the canister material options for the disposal of high level waste and spent fuel in a deep geological repository in Opalinus Clay. Following a brief period of aerobic conditions, the canister will be exposed to an anaerobic environment for much of its service life. Knowledge of the rate of anaerobic corrosion is important not only for estimating the canister lifetime but also for determining the rate of hydrogen generation. This report describes a critical review of the anaerobic corrosion behaviour of carbon steel under environmental conditions similar to those expected in the repository. The aims of the report are: 1. to recommend a (range of) long-term anaerobic corrosion rate(s) for carbon steel canisters, and 2. to justify the use of this rate in safety assessments based on a mechanistic understanding of the structure and properties of the protective corrosion product films. The review is based on selected studies from various national nuclear waste management programs, supplemented where appropriate with studies from other applications and with evidence from archaeological analogues. The corrosion rate of carbon steel decreases with time because of the formation of a protective surface film. There are differences in behaviour in bulk solution and in the presence of compacted bentonite. In bulk solution, the corrosion rate decreases to an apparent steady-state rate after a period of approximately six months, with a long-term rate of the order of 0.1 μm·.yr-1. The surface film comprises a duplex structure, with a magnetite outer layer and a spinel-type inner layer. In compacted clay systems the rate of decrease in corrosion rate is slower, with steady state not being reached after several years of exposure. There is a significant body of evidence from apparently well-conducted experiments that indicate an anaerobic corrosion rate of the order of 1-2 μm·yr-1 in systems containing compacted clay and the protective

  18. 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.

  19. 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

    different plasma powers and monomer compositions was used. Maleic anhydride (MAR) and 1,2-methylenedioxybenzene (MDOB) were plasma deposited separately and as mixtures to create layers with different surface compositions. In all cases the MAR was hydrolyzed to form carboxylic acid groups. Some carboxylic...... 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...

  20. Applications of cavity ring-down spectroscopy to high precision isotope ratio measurement of 13C/12C in carbon dioxide.

    Science.gov (United States)

    Wahl, Ed H; Fidric, Bernard; Rella, Chris W; Koulikov, Sergei; Kharlamov, Boris; Tan, Sze; Kachanov, Alexander A; Richman, Bruce A; Crosson, Eric R; Paldus, Barbara A; Kalaskar, Shashi; Bowling, David R

    2006-03-01

    Recent measurements of carbon isotopes in carbon dioxide using near-infrared, diode-laser-based cavity ring-down spectroscopy (CRDS) are presented. The CRDS system achieved good precision, often better than 0.2 per thousand, for 4% CO2 concentrations, and also achieved 0.15-0.25 per thousand precision in a 78 min measurement time with cryotrap-based pre-concentration of ambient CO2 concentrations (360 ppmv). These results were obtained with a CRDS system possessing a data rate of 40 ring-downs per second and a loss measurement of 4.0 x 10(-11) cm(-1) Hz(-1/2). Subsequently, the measurement time has been reduced to under 10 min. This standard of performance would enable a variety of high concentration (3-10%) isotopic measurements, such as medical human breath analysis or animal breath experiments. The extension of this ring-down to the 2 microm region would enable isotopic analysis at ambient concentrations, which, combined with the small size, robust design, and potential for frequent measurements at a remote site, make CRDS technology attractive for remote atmospheric measurement applications. PMID:16500752

  1. Stable Carbon and Nitrogen isotopic characterization of bulk atmospheric particles over Indian coastal site (Goa) during monsoon, post-monsoon and winter periods of 2011-12

    Science.gov (United States)

    Yadav, K.; Agnihotri, R.; Sarma, V. V.; Karapurkar, S. G.; Poosarla, P. K.; Kumar, M. D.

    2012-12-01

    Atmospheric carbonaceous aerosols are known for their influential nature on regional biogeochemical cycles of biogenic elements e.g. carbon (C) and nitrogen (N) as well as to radiation budgets. As they may have multiple primary sources of natural and anthropogenic origin, their detailed chemical and isotopic characterization can greatly help in identifying source and secondary processes they undergo. Using high volume air sampler, bulk aerosols were collected on tissue quartz filters from the roof of National Institute of Oceanography Goa (15.46o N, 73.8oE; at 55.8 MASL height) on almost weekly intervals for the monsoon, post- monsoon, and full winter period of 2011-12. Nearly 60 aerosol samples were analyzed for their carbon (TC) and nitrogen TN mass concentrations together with their isotopic values (δ13C, δ15N). Overall, δ13C of TC varied in a narrow range (average: -22.8±2.7‰) compared to δ15N of TN, showing a wider range (average: 12.7±5.1‰) during this sampling campaign. δ15N of bulk aerosols were found to be significantly lower (average: 3.0±0.5‰ ; n=7) during monsoon period as compared to those for post monsoon (average: 12.3±3.8‰ ; n=6) and winter period (average: 14.2±3.8‰; n=47). In contrast, δ13C of TC were found to be similar during monsoon, post-monsoon and winter periods (average: -23.8±2.3‰, -23.6±1.9‰, -23.1±1.8‰, respectively). TSP mass concentrations together with their TC and TN contents also showed clear differences; highest values during winter and late winter as compared to monsoon and post monsoon periods. Lower δ15N values of Goa aerosols during monsoon are similar to those during pre monsoon period (Agnihotri et al., 2011) and thereby attributable to incorporation of isotopically depleted nitrogenous compounds originating from adjacent Arabian Sea. δ13C of TC values, on an average, represent an intermediate value of carbonaceous material originating from continental and marine sources (-26‰ and -21

  2. Elastic and inelastic scattering of polarized protons from carbon-12 at 400, 600, and 700 MeV

    International Nuclear Information System (INIS)

    Good resolution cross section and analyzing power (p vector, p') data for many states in 12C up to an excitation energy of 21 MeV and spanning a momentum transfer range of 0.3 to 2.1 fm-1 were obtained using the High Resolution Spectrometer at the Clinton P. Anderson Meson Physics Facility at incident beam energies of 398, 597, and 698 MeV. Optical model potentials were obtained from the elastic scattering data. Inelastic data were analyzed in the Distorted Wave Impulse Approximation using the Love-Franey effective nucleon-nucleon interaction. The energy dependent isoscalar natural parity cross sections were underestimated, while phase difficulties were encountered in fitting analyzing powers. The energy independent isovector natural parity cross sections were reasonably reproduced, but analyzing powers were not, the calculations yielding positive trends whereas the data are of opposite sign. The energy independent isoscalar and isovector unnatural parity cross sections were quite well reproduced up to moderate momentum transfers, and striking successes were observed for some analyzing power data. Systematics of energy dependence together with the results of the DWIA calculations permitted the assignment of spin, parity and isospin quantum numbers to states in the 18-21 MeV excitation region. 64 references

  3. 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).

  4. 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).

  5. A facile method to synthesize carbon coated Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.6}O{sub 2} with improved performance

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yunjian, E-mail: lyjian122331@yahoo.com.cn [School of Material Science and Technology Jiangsu University, Zhenjiang (China); Automobile Engineering Research Institute Jiangsu University, Zhenjiang (China); Gao, Yanyong; Lv, Jun [School of Material Science and Technology Jiangsu University, Zhenjiang (China); Chen, Long [Automobile Engineering Research Institute Jiangsu University, Zhenjiang (China)

    2013-11-15

    Graphical abstract: Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.6}O{sub 2} powders are synthesized and then coated by decomposed carbon. The discharge capacity of carbon-coated cathode at 0.1 and 5 C are 246 and 125 mAhg{sup −1}, while those of ball-milled cathode are 222 and 49 mAhg{sup −1}. - Highlights: • A simple method was applied to synthesize carbon-coated Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.6}O{sub 2}. • The discharge capacities of carbon-coated sample at 0.1 and 5.0 C rates are 246 and 125 mAh/g. • Capacity retention of carbon-coated electrode after 50 cycles is 97.5%. - Abstract: Carbon-coated Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.6}O{sub 2} powders have been synthesized with Bakelite and heat process in air. The effect of carbon coating on the physical and electrochemical properties have been discussed through the characterizations of X-ray diffraction (XRD), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), discharge and rate tests. The carbon-coated cathode exhibits much improved first discharge capacity and rate capability than the pristine sample. The discharge capacity at 0.1 and 5.0 C rates are 246 and 125 mAhg{sup −1}, while that of pristine are only about 222 and 49 mAhg{sup −1}, respectively. The capacity retention of Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.6}O{sub 2} electrode after 50 cycles is improved from 89.8 to 97.5% after carbon coating. EIS results indicate that R{sub ct} of Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.6}O{sub 2} electrode is decreased from 62 to 37 Ω after carbon coating.

  6. High sensitivity Cavity Ring Down spectroscopy of 18O enriched carbon dioxide between 5850 and 7000 cm-1: Part III-Analysis and theoretical modeling of the 12C17O2, 16O12C17O, 17O12C18O, 16O13C17O and 17O13C18O spectra

    CERN Document Server

    Karlovets, E V; Mondelain, D; Kassi, S; Tashkun, S A; Perevalov, V I

    2014-01-01

    More than 19,700 transitions belonging to 11 isotopologues of carbon dioxide have been assigned in the room temperature absorption spectrum of highly 18O enriched carbon dioxide recorded by very high sensitivity CW-Cavity Ring Down spectroscopy between 5851 and 6990 cm-1 (1.71-1.43 \\mum). This third and last report is devoted to the analysis of the bands of five 17O containing isotopologues present at very low concentration in the studied spectra: 16O12C17O, 17O12C18O, 16O13C17O, 17O13C18O and 12C17O2 (627, 728, 637, 738 and 727 in short hand notation). On the basis of the predictions of effective Hamiltonian models, a total of 1759, 1786, 335, 273 and 551 transitions belonging to 24, 24, 5, 4 and 7 bands were rovibrationally assigned for 627, 728, 637, 738 and 727, respectively. For comparison, only five bands were previously measured in the region for the 728 species. All the identified bands belong to the \\deltaP=8 and 9 series of transitions, where P=2V1+V2+3V3 is the polyad number (Vi are vibrational qua...

  7. 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)

  8. 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)

  9. 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.

  10. 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...

  11. 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.

  12. Processing of carbon-fiber-reinforced Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 bulk metallic glass composites

    OpenAIRE

    Kim, C. P.; Busch, R.; Masuhr, A.; Choi-Yim, H.; Johnson, W. L.

    2001-01-01

    Carbon-fiber-reinforced bulk metallic glass composites are produced by infiltrating liquid Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 into carbon fiber bundles with diameter of the individual fiber of 5 mum. Reactive wetting occurs by the formation of a ZrC layer around the fibers. This results in a composite with a homogeneous fiber distribution. The volume fraction of the fibers is about 50% and the density of the composite amounts to 4.0 g/cm(^3).

  13. 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.

  14. A 12-year record reveals pre-growing season temperature and water table level threshold effects on the net carbon dioxide exchange in a boreal fen

    International Nuclear Information System (INIS)

    This study uses a 12-year time series (2001–2012) of eddy covariance measurements to investigate the long-term net ecosystem exchange (NEE) of carbon dioxide (CO2) and inter-annual variations in relation to abiotic drivers in a boreal fen in northern Sweden. The peatland was a sink for atmospheric CO2 in each of the twelve study years with a 12-year average (± standard deviation) NEE of −58 ± 21 g C m−2 yr−1. For ten out of twelve years, the cumulative annual NEE was within a range of −42 to −79 g C m−2 yr−1 suggesting a general state of resilience of NEE to moderate inter-annual climate variations. However, the annual NEE of −18 and −106 g C m−2 yr−1 in 2006 and 2008, respectively, diverged considerably from this common range. The lower annual CO2 uptake in 2006 was mainly due to late summer emissions related to an exceptional drop in water table level (WTL). A positive relationship (R 2 = 0.65) between pre-growing season (January to April) air temperature (Ta) and summer (June to July) gross ecosystem production (GEP) was observed. We suggest that enhanced GEP due to mild pre-growing season air temperature in combination with air temperature constraints on ecosystem respiration (ER) during the following cooler summer explained most of the greater net CO2 uptake in 2008. Differences in the annual and growing season means of other abiotic variables (e.g. radiation, vapor pressure deficit, precipitation) and growing season properties (i.e. start date, end date, length) were unable to explain the inter-annual variations of NEE. Overall, our findings suggest that this boreal fen acts as a persistent contemporary sink for atmospheric CO2 that is, however, susceptible to severe anomalies in WTL and pre-growing season air temperature associated with predicted changes in climate patterns for the boreal region. (papers)

  15. 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...

  16. 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...

  17. 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

  18. Preparation and electrochemical performance of hyper-networked Li{sub 4}Ti{sub 5}O{sub 12}/carbon hybrid nanofiber sheets for a battery-supercapacitor hybrid system

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hong Soo; Kim, TaeHoon; Im, Ji Hyuk; Park, Chong Rae, E-mail: crpark@snu.ac.kr [Carbon Nanomaterials Design Laboratory, Global Research Laboratory, Research Institute of Advanced Materials, and Department of Materials Science and Engineering, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul 151-744 (Korea, Republic of)

    2011-10-07

    Hyper-networked Li{sub 4}Ti{sub 5}O{sub 12}/carbon hybrid nanofiber sheets that contain both a faradaically rechargeable battery-type component, namely Li{sub 4}Ti{sub 5}O{sub 12}, and a non-faradaically rechargeable supercapacitor-type component, namely N-enriched carbon, are prepared by electrospinning and their dual function as a negative electrode of lithium-ion batteries (LIBs) and a capacitor is tested for a new class of hybrid energy storage (denoted BatCap). An aqueous solution composed of polyvinylpyrrolidone, lithium hydroxide, titanium(IV) bis(ammonium-lactato)dihydroxide and ammonium persulfate is electrospun to obtain hyper-networked nanofiber sheets. Next, the sheets are exposed to pyrrole monomer vapor to prepare the polypyrrole-coated nanofiber sheets (PPy-HNS). The hyper-networked Li{sub 4}Ti{sub 5}O{sub 12}/N-enriched carbon hybrid nanofiber sheets (LTO/C-HNS) are then obtained by a stepwise heat treatment of the PPy-HNS. The LTO/C-HNS deliver a specific capacity of 135 mAh g{sup -1} at 4000 mA g{sup -1} as a negative electrode for LIBs. In addition, potentiodynamic experiments are performed using a full cell with activated carbon (AC) as the positive electrode and LTO/C-HNS as the negative electrode to estimate the capacitance properties. This new asymmetric electrode system exhibits a high energy density of 91 W kg{sup -1} and 22 W kg{sup -1} at power densities of 50 W kg{sup -1} and 4000 W kg{sup -1}, respectively, which are superior to the values observed for the AC||AC symmetric electrode system.

  19. 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.

  20. 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...

  1. 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。

  2. 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.

  3. Inactivation of E. coli K12 in buffered peptone water and apple cider by pilot-plant scale supercritical carbon dioxide system

    Science.gov (United States)

    There is increasing interest in non-thermal processing to inactivate foodborne pathogens and background microflora in juice products. Non-thermal pasteurization ensures safety and may offer better quality products than thermal pasteurization. Of non-thermal technologies, use of supercritical carbon ...

  4. 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).

  5. 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.

  6. 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).

  7. 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.

  8. 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

  9. Li1.2Mn0.54Ni0.13Co0.13O2-Encapsulated Carbon Nanofiber Network Cathodes with Improved Stability and Rate Capability for Li-ion Batteries

    Science.gov (United States)

    Ma, Dingtao; Zhang, Peixin; Li, Yongliang; Ren, Xiangzhong

    2015-06-01

    Li1.2Mn0.54Ni0.13Co0.13O2-encapsulated carbon nanofiber network cathode materials were synthesized by a facile electrospinning method. The microstructures, morphologies and electrochemical properties are characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM), galvonostatic charge/discharge tests, cyclic voltammetry and electrochemical impedance spectroscopy (EIS), etc. The nanofiber decorated Li1.2Mn0.54Ni0.13Co0.13O2 electrode demonstrated higher coulombic efficiency of 83.5%, and discharge capacity of 263.7 mAh g-1 at 1 C as well as higher stability compared to the pristine particle counterpart. The superior electrochemical performance results from the novel network structure which provides fast transport channels for electrons and lithium ions and the outer carbon acts a protection layer which prevents the inner oxides from reacting with HF in the electrolyte during charge-discharge cycling.

  10. 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.

  11. 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...

  12. 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)

  13. 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.

  14. 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.

  15. 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.

  16. 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...

  17. 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.

  18. Preparation and analysis of amorphous carbon films deposited from (C6H12)/Ar/He chemistry for application as the dry etch hard mask in the semiconductor manufacturing process

    International Nuclear Information System (INIS)

    Amorphous carbon layers (ACL) were deposited on Si (100) wafers by plasma enhanced chemical vapor deposition (PECVD) by using 1-hexene (C6H12) 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 (H2O:HF = 200:1), SC1 (NH4OH:H2O2:H2O = 1:4:20) solution, and sulfuric acid solution (H2SO4:H2O2 = 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 C6H12 at 550 deg. C for application as the dry etch hard mask in fabrication of semiconductor devices.

  19. 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.

  20. 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

  1. 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%.

  2. Tendances Carbone n. 12 Mar. 2007

    International Nuclear Information System (INIS)

    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 CO2 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, CO2 quotas allocated to European Union countries, and detailed indicators of CO2 market, climate, economic activity and energy prices. (J.S.)

  3. Carbon isotope techniques

    International Nuclear Information System (INIS)

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

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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.

  10. Modification of Carrier Gas Stream to Improve 13C/12C Isotopic Accuracy in Cavity Ring-Down Spectroscopy-Based Measurements of Low-Concentration Dissolved Carbon Samples

    Science.gov (United States)

    Conaway, C. H.; Morkner, P.; Thomas, B.; Saad, N.

    2013-12-01

    Determining isotopic composition of dissolved organic and inorganic carbon in natural waters is of critical importance to a broad set of scientific objectives. The routine analysis of these sample types can be expensive and in the past has been limited predominantly to laboratories capable of high-precision isotope ratio mass spectrometric analysis. More recently, cavity ring-down spectroscopy (CRDS) has provided an alternative instrumental means for characterizing these samples. One challenge with these types of is that the CRDS can show a non-linear response in d13C at low carbon concentrations (<0.5 mM). Here we present a new approach using a modification of a total organic carbon-cavity ring-down spectroscopy (TOC-CRDS) continuous flow system by adding a background stream of carbon dioxide of known isotopic composition to the CRDS analytical train. The isotopic carbon values generated by the CRDS are then corrected using a two-component isotopic mixing model. This modification is useful in reducing bias towards lighter carbon isotopic values when measuring samples with low carbon concentration, such as natural waters with either dissolved organic or inorganic carbon concentrations of less than 0.5 mM, and does not introduce substantial bias for higher concentration samples.

  11. 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...

  12. 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.

  13. 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...

  14. 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...

  15. 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.

  16. 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...

  17. 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.

  18. 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...

  19. 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...

  20. 12 MW

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Pena Diaz, Alfredo; Mikkelsen, Torben; Gryning, Sven-Erik; Courtney, Michael; Sørensen, Paul B.

    establish the scientific basis relevant for the next generation of huge 12 MW wind turbines operating offshore. The project started 1st October 2005 and ended 31st March 2009. Firstly was conducted a 6-month experiment at the Horns Rev offshore wind farm deploying a lidar and a sodar on the transformer...... platform. The observed data were successfully compared to offshore mast data and the wind profile was extended 100 m above previous levels observed in this offshore environment. The wind and turbulence was observed up to 160m above mean sea level. A new normalization was introduced to group the wind...... profiles into stability groups with variable roughness. Secondly two experiments were conducted at Høvsøre at the North Sea coast in Jutland. Again the wind profile was extended far beyond previous observed levels, up to 300 m above ground. The analysis showed that the profiles extended far beyond the...

  1. Porous carbons

    Indian Academy of Sciences (India)

    Satish M Manocha

    2003-02-01

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

  2. 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.

  3. 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 oral reef carbonate chemistry over time, at US affiliated coral reef sites, through quantifying...

  4. 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...

  5. 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.

  6. 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.

  7. Measurement of carbon thermodynamic activity in sodium

    International Nuclear Information System (INIS)

    The report presents the brief outline on system of carbon activity detecting system in sodium (SCD), operating on the carbon-permeable membrane, of the methods and the results of testing it under the experimental circulating loop conditions. The results of carbon activity sensor calibration with the use of equilibrium samples of XI8H9, Fe -8Ni, Fe -12Mn materials are listed. The behaviour of carbon activity sensor signals in sodium under various transitional conditions and hydrodynamic perturbation in the circulating loop, containing carbon bearing impurities in the sodium flow and their deposits on the surfaces flushed by sodium, are described. (author)

  8. 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.

  9. 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 ...

  10. 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.

  11. Wet deposition of elemental carbon and sulfate in Sweden

    OpenAIRE

    Ogren, J.A.; R. J. Charlson

    2011-01-01

    Elemental carbon and sulfate were measured in monthly precipitation samples at 12 rural sites inSweden from April to August, 1981. Wet deposition of excess sulfate was significantly correlatedwith elemental carbon deposition, and no systematic spatial or temporal variations in the ratio ofexcess sulfate to elemental carbon were observed. Comparision of these results with sulfur andelemental carbon emissions in Western Europe suggests that elemental carbon is removed at aslower rate than sulfu...

  12. 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.

  13. Theoretical investigation of stabilities and optical properties of Si12C12 clusters

    International Nuclear Information System (INIS)

    By sorting through hundreds of globally stable Si12C12 isomers using a potential surface search and using simulated annealing, we have identified low-energy structures. Unlike isomers knit together by Si–C bonds, the lowest energy isomers have segregated carbon and silicon regions that maximize stronger C–C bonding. Positing that charge separation between the carbon and silicon regions would produce interesting optical absorption in these cluster molecules, we used time-dependent density functional theory to compare the calculated optical properties of four isomers representing structural classes having different types of silicon and carbon segregation regions. Absorptions involving charge transfer between segregated carbon and silicon regions produce lower excitation energies than do structures having alternating Si–C bonding for which frontier orbital charge transfer is exclusively from separated carbon atoms to silicon atoms. The most stable Si12C12 isomer at temperatures below 1100 K is unique as regards its high symmetry and large optical oscillator strength in the visible blue. Its high-energy and low-energy visible transitions (1.15 eV and 2.56 eV) are nearly pure one-electron silicon-to-carbon transitions, while an intermediate energy transition (1.28 eV) is a nearly pure carbon-to-silicon one-electron charge transfer

  14. Introducing carbon taxes in South Africa

    International Nuclear Information System (INIS)

    Highlights: • South Africa is considering introducing a carbon tax to reduce greenhouse gas emissions. • A phased-in tax of US$30 per ton can achieve national emissions reductions targets set for 2025. • Ignoring all potential benefits, the tax reduces national welfare by about 1.2 percent in 2025. • Border carbon adjustments reduce welfare losses while maintaining emissions reductions. • The mode for recycling carbon tax revenues strongly influences distributional outcomes. - Abstract: South Africa is considering introducing a carbon tax to reduce greenhouse gas emissions. Following a discussion of the motivations for considering a carbon tax, we evaluate potential impacts using a dynamic economywide model linked to an energy sector model including a detailed evaluation of border carbon adjustments. Results indicate that a phased-in carbon tax of US$30 per ton of CO2 can achieve national emissions reductions targets set for 2025. Relative to a baseline with free disposal of CO2, constant world prices and no change in trading partner behavior, the preferred tax scenario reduces 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

  15. 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...

  16. 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.

  17. 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

  18. Contribution to analysis of fatigue crack propagation at room temperature in low carbon austenitic steels type 18-10(304L) and Mo 17-12(316L). Relation between macroscopic and microscopic phenomena

    International Nuclear Information System (INIS)

    Low cycle fatigue phenomenon on the structural components of reactors is one of the most important problem. In this paper were carried out some fatigue tests on stainless steels type Z2CN18-10 (AISI 304L) and Z2CND17-12 (AISI 316L) at room temperature in air and in a corrosive medium (NaCl solution at different pH values). Length of cracks and crack propagation under stresses were determined. Z2CND17-12 has a better behavior than Z2CN18-10 because of a better structural stability both in air and in a corrosive environment. Structure was examined by transmission electron microscopy and microhardness was measured in the perturbed zones

  19. 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...

  20. Evaluation of bioremediation systems utilizing stable carbon isotope analysis

    International Nuclear Information System (INIS)

    Carbon, whether in an organic or inorganic form, is composed primarily of two stable isotopes, carbon-12 and carbon-13. The ratio of carbon-12 to carbon-13 is approximately 99:1. The stable carbon isotope ratios of most natural carbon materials of biological interest range from approximately 0 to -110 per mil (per-thousand) versus the PDB standard. Utilizing stable carbon isotope analysis, it is often possible to determine the source(s) of the liberated carbon dioxide, thereby confirming successful mineralization of the targeted carbon compound(s) and, if the carbon dioxide results from multiple carbon compounds, in what ratio the carbon compounds are mineralized. Basic stable isotope 'theory' recommended sampling procedures and analysis protocols are reviewed. A case study involving fuel oil presented on the application of stable carbon isotope analysis for the monitoring and evaluation of in situ bioremediation. At the site, where a field bioventing study was being conducted, multiple potential sources of carbon dioxide production existed. Additional potential applications of stable carbon isotope analysis for bioremediation evaluation and monitoring are discussed

  1. Carbon particles

    Science.gov (United States)

    Hunt, Arlon J.

    1984-01-01

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

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

  3. 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.

  4. 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...

  5. 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...

  6. 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...

  7. 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.

  8. 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...

  9. 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.

  10. 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).

  11. Black carbon in deep-sea sediments

    OpenAIRE

    Masiello, CA; Druffel, ERM

    1998-01-01

    Black carbon (BC) enters the ocean through aerosol and river deposition. BC makes up 12 to 31 percent of the sedimentary organic carbon (SOC) at two deep ocean sites, and it is 2400 to 13,900 carbon-14 years older than non-BC SOC deposited concurrently. BC is likely older because it is stored in an intermediate reservoir before sedimentary deposition. Possible intermediate pools are oceanic dissolved organic carbon (DOC) and terrestrial soils. If DOC is the intermediate reservoir, then BC is ...

  12. Measurement of the concentration ratio for 13N and 12N isotopes at atmospheric pressure by carbon dioxide absorption of diode laser radiation at ∼2 μm

    International Nuclear Information System (INIS)

    The ratio of 12NO2 and 13CO2 concentrations in the human exhaled air is measured by the method of diode laser spectroscopy using a three-channel optical scheme and multipass cell. Unlike the previous measurements in the spectral range of ∼4.3 μm with a resolved rotational structure at low pressure of selected samples, the present measurements are performed in the range of ∼2 μm, in which weaker absorption bands of CO2 reside. In this case, it is possible to employ lasers and photodetectors operating at room temperature. The thorough simulation of the spectrum with collisional broadening of lines and employment of regression analysis allow one to take measurements at atmospheric pressure with the accuracy of ∼0.04%, which satisfies the requirements to medical diagnostics of ulcers. (laser spectroscopy)

  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. 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

  15. 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.

  16. 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....

  17. The carbon is down the hole

    International Nuclear Information System (INIS)

    Each year, about 7.1 billions of tons of carbon are released by human activities and industries, from which 5.5 come from the combustion of fossil fuels and 1.6 is a direct consequence of deforestation. However, less than half of this carbon is kept by the atmosphere in its CO2 form and contributes to the anthropic greenhouse effect. The rest is necessarily absorbed by carbon sinks, some of them located in the oceans and responsible for the disappearing of about 2 billions of tons of carbon, and the others probably located in the continental biosphere and in particular in the vegetal biomass and the organic matter of soils. This additional storage is probably located in the northern hemisphere between 30 deg. N and 60 deg. N. The distinction between the continental and oceanic sinks is made according to the concentration ratios of carbon 12 and carbon 13 isotopes. (J.S.)

  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. 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 ...

  20. 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...

  1. 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

  2. Carbon Footprints

    OpenAIRE

    Rahel Aichele; Gabriel Felbermayr

    2011-01-01

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

  3. 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.

  4. Vitamin B12 level

    Science.gov (United States)

    The vitamin B12 level is a blood test that measures how much vitamin B12 is in your blood. ... form of megaloblastic anemia caused by poor vitamin B12 absorption. This can occur when the stomach makes ...

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

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  8. 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...

  9. High sensitivity Cavity Ring Down spectroscopy of 18O enriched carbon dioxide between 5850 and 7000 cm−1: Part II—Analysis and theoretical modeling of the 12C18O2, 13C18O2 and 16O13C18O spectra

    International Nuclear Information System (INIS)

    More than 19000 transitions belonging to 11 isotopologues of carbon dioxide have been assigned in the room temperature absorption spectrum of highly 18O enriched carbon dioxide recorded by very high sensitivity CW-Cavity Ring Down spectroscopy between 5851 and 6990 cm−1 (1.71–1.43 μm). The line positions were determined with accuracy better than 1×10−3 cm−1 while the absolute line intensities are reported with an uncertainty better than 10%. This second report is devoted to the analysis of the bands of three multiply substituted isotopologues: 12C18O2, 13C18O2 and 16O13C18O (828, 838 and 638 in short hand notation). On the basis of the predictions of effective Hamiltonian models, a total of 2870, 538 and 1375 transitions belonging to 59, 11 and 15 bands were rovibrationnally assigned for 828, 838 and 638, respectively. For comparison, only 11 bands were previously measured by Fourier Transform spectroscopy in the region, for the 828 species. All the identified bands correspond to a ΔP=9 variation of the polyad number (P=2V1+V2+3V3, where Vi are vibrational quantum numbers). The band-by-band analysis has allowed deriving accurate spectroscopic parameters of 81 bands from a fit of the measured line positions. A few resonance perturbations were identified. In particular, the 31113 and 51106 states of 638 belonging to different polyads (P=10 and P=11, respectively) are anharmonically coupled. Using the large set of newly measured line positions and those collected from the literature, the global modeling of the line positions within the effective Hamiltonian approach was performed and a new set of Hamiltonian parameters was obtained for each of the three considered isopotologues. Using a similar approach, the global fits of the obtained intensity values of the ΔP=9 series of transitions were used to derive the corresponding ΔP=9 effective dipole moment parameters of the three considered isotopologues. The obtained results will help to improve the quality

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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 ...

  15. 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...

  16. 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 ...

  17. 75 FR 20813 - Certain Magnesia Carbon Bricks from the People's Republic of China: Amended Preliminary...

    Science.gov (United States)

    2010-04-21

    ... Determination, 75 FR 11847 (March 12, 2010) (``Preliminary Determination''). We are amending our Preliminary... International Trade Administration Certain Magnesia Carbon Bricks from the People's Republic of China: Amended... value (``LTFV'') in the antidumping duty investigation of certain magnesia carbon bricks...

  18. 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.

  19. 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...

  20. 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.

  1. 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...

  2. 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

  3. 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

  4. The importance of a surface organic layer in simulating permafrost thermal and carbon dynamics

    Science.gov (United States)

    Jafarov, Elchin; Schaefer, Kevin

    2016-03-01

    Permafrost-affected soils contain twice as much carbon as currently exists in the atmosphere. Studies show that warming of the perennially frozen ground could initiate significant release of the frozen soil carbon into the atmosphere. Initializing the frozen permafrost carbon with the observed soil carbon distribution from the Northern Circumpolar Soil Carbon Database reduces the uncertainty associated with the modeling of the permafrost carbon feedback. To improve permafrost thermal and carbon dynamics we implemented a dynamic surface organic layer with vertical carbon redistribution, and introduced dynamic root growth controlled by active layer thickness, which improved soil carbon exchange between frozen and thawed pools. These changes increased the initial amount of simulated frozen carbon from 313 to 560 Gt C, consistent with observed frozen carbon stocks, and increased the spatial correlation of the simulated and observed distribution of frozen carbon from 0.12 to 0.63.

  5. Composite carbon foam electrode

    Science.gov (United States)

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

    1997-05-06

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

  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. 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

  8. 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 new model formulation produced soil carbon stock estimates that were much closer to measured values. It also captured better the seasonal cycle of the direct CO2 exchange measurements at the three grassland sites considered (RMS error reduced by 12%), while for the five forest sites also analyzed......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 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...

  9. Vitamin B12

    Science.gov (United States)

    ... with other B vitamins, such as niacin, riboflavin, vitamin B6, and magnesium. A prescription form of vitamin B12 ... Nutrition Board. Dietary Reference Intakes: Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. ...

  10. 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...

  11. Mutagenicity of carbon nanomaterials

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  12. 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

  13. Pyrolyzed thin film carbon

    Science.gov (United States)

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

    2010-01-01

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

  14. Heteronuclear carbon nanotubes: applications to study carbon nanotube growth

    International Nuclear Information System (INIS)

    Full text: Synthesis of heteronuclear carbon nanotubes and their application for a variety of studies is presented. SWCNTs peapods encapsulating highly 13C enriched fullerenes and double wall carbon nanotubes (DWCNTs) based on the peapods were prepared. Raman studies indicate that the inner tubes are highly 13C enriched with no carbon exchange between the two walls during the synthesis. The material enables the straightforward identification of the inner and outer tube vibrational spectra. An inhomogeneous broadening, assigned to the random distribution of 12C and 13C nuclei is observed and is explained by ab initio vibrational analysis. The growth of inner tubes from organic solvents was proven by the use of 13C labeled organic materials such as toluene. The simultaneous encapsulation of fullerenes with the solvents was found crucial as these prevent the solvents from evaporating during the high temperature synthesis of the inner tubes. Nuclear magnetic resonance on the peapods and DWCNTs with highly 13C enriched fullerenes or inner walls proves the significant contrast of the isotope enriched SWCNTs as compared to other carbon phases. The NMR experiment on the DWCNTs yield direct information on the electronic properties of small diameter SWCNTs. The significantly different chemical shift of the inner tubes is related to a curvature effect. Relaxation data on the inner tubes shows a deviation from a Fermi-liquid behavior. (author)

  15. The effect of 12C + 12C rate uncertainties on the evolution and nucleosynthesis of massive stars

    CERN Document Server

    Bennett, M E; Pignatari, M; Diehl, S; Fryer, C; Herwig, F; Hungerford, A; Nomoto, K; Rockefeller, G; Timmes, F X; Wiescher, M

    2012-01-01

    [Shortened] The 12C + 12C fusion reaction has been the subject of considerable experimental efforts to constrain uncertainties at temperatures relevant for stellar nucleosynthesis. In order to investigate the effect of an enhanced carbon burning rate on massive star structure and nucleosynthesis, new stellar evolution models and their yields are presented exploring the impact of three different 12C + 12C reaction rates. Non-rotating stellar models were generated using the Geneva Stellar Evolution Code and were later post-processed with the NuGrid Multi-zone Post-Processing Network tool. The enhanced rate causes core carbon burning to be ignited more promptly and at lower temperature. This reduces the neutrino losses, which increases the core carbon burning lifetime. An increased carbon burning rate also increases the upper initial mass limit for which a star exhibits a convective carbon core. Carbon shell burning is also affected, with fewer convective-shell episodes and convection zones that tend to be large...

  16. Wood - a carbon depot

    OpenAIRE

    Lipušček, Igor; Tišler, Vesna

    2003-01-01

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

  17. 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.

  18. 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. 

  19. 12 CFR 12.2 - Definitions.

    Science.gov (United States)

    2010-01-01

    ..., bank as trustee acting as shareholder of record for the purchase or sale of securities, or issuer of.... (b) Collective investment fund means any fund established pursuant to 12 CFR 9.18. (c) Completion of... of securities (including any interest therein or based on the value thereof), or, in general,...

  20. 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...

  1. 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...

  2. 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...

  3. 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

  4. Systematic AMD+GCM Study of Structure of Carbon Isotopes

    International Nuclear Information System (INIS)

    The structure of low-lying states of the carbon isotopes is investigated using the extended version of the Antisymmetrized Molecular Dynamics (AMD) Multi-Slater Determinant model. We can reproduce reasonably well many experimental data for carbon isotopes 12C-22C. A special approach is adopted for 15C to better describe the tail of the wave function

  5. Softening of the Radial Breathing Mode in Metallic Carbon Nanotubes

    Czech Academy of Sciences Publication Activity Database

    Farhat, H. (ed.); Sasaki, K.; Kalbáč, Martin; Hofmann, M.; Saito, R.; Dresselhaus, M. S.; Kong, J.

    2009-01-01

    Roč. 102, č. 12 (2009), 126804-1-126804-4. ISSN 0031-9007 Institutional research plan: CEZ:AV0Z40400503 Keywords : metallic carbon nanotubes * radial breathing mode * single waled carbon nanotubes Subject RIV: CG - Electrochemistry Impact factor: 7.328, year: 2009

  6. 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

  7. 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.

  8. 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...

  9. Genetic characterization of the pdu operon: use of 1,2-propanediol in Salmonella typhimurium.

    OpenAIRE

    Walter, D; Ailion, M; Roth, J

    1997-01-01

    Salmonella typhimurium is able to catabolize 1,2-propanediol for use as the sole carbon and energy source; the first enzyme of this pathway requires the cofactor adenosyl cobalamin (Ado-B12). Surprisingly, Salmonella can use propanediol as the sole carbon source only in the presence of oxygen but can synthesize Ado-B12 only anaerobically. To understand this situation, we have studied the pdu operon, which encodes proteins for propanediol degradation. A set of pdu mutants defective in aerobic ...

  10. Multi-wall carbon nanotubes with nitrogen-containing carbon coating

    Czech Academy of Sciences Publication Activity Database

    Tomšík, Elena; Morávková, Zuzana; Stejskal, Jaroslav; Trchová, Miroslava; Šálek, Petr; Kovářová, Jana; Zemek, Josef; Cieslar, M.; Prokeš, J.

    2013-01-01

    Roč. 67, č. 8 (2013), s. 1054-1065. ISSN 0366-6352 R&D Projects: GA ČR GPP108/11/P763; GA ČR GAP205/12/0911; GA ČR GA202/09/0428 Institutional support: RVO:61389013 ; RVO:68378271 Keywords : polyaniline coating * carbonization * multi-wall carbon nanotubes Subject RIV: CD - Macromolecular Chemistry; BM - Solid Matter Physics ; Magnetism (FZU-D) Impact factor: 1.193, year: 2013

  11. Simulations of nanosensors based on single walled carbon nanotubes

    International Nuclear Information System (INIS)

    The potential of single-walled carbon nanotubes as mass sensors is examined. The change in mass leads to proportional changes in the nanotube vibrational frequencies, which are monitored during atomistic simulations. We observed a frequency shift as a result of replacement of carbon C12 with its isotope C13. For a zigzag (12,0) nanotube of about 10 nm length, we found zeptogram sensitivity.

  12. 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)

  13. The Properties and Application of Carbon Nanostructures

    Czech Academy of Sciences Publication Activity Database

    Slepička, P.; Hubáček, T.; Kolská, Z.; Trostová, S.; Kasálková-Slepičková, N.; Bačáková, Lucie; Švorčík, V.

    Rijeka: InTech, 2013 - (Yilmaz, F.), s. 175-199 ISBN 978-953-51-0941-9 R&D Projects: GA ČR(CZ) GAP108/10/1106; GA ČR(CZ) GAP108/12/1168 Institutional support: RVO:67985823 Keywords : carbon nanostructures * properties * tissue engineering Subject RIV: JJ - Other Materials

  14. Erbium doping into thin carbon optical layers

    Czech Academy of Sciences Publication Activity Database

    Prajzler, V.; Huttel, I.; Nekvindová, P.; Schrofel, J.; Macková, Anna; Gurovič, J.

    2003-01-01

    Roč. 433, 1/2 (2003), s. 363-366. ISSN 0040-6090 R&D Projects: GA AV ČR KSK1010104 Keywords : carbon layers * erbium Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.598, year: 2003

  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. Estimation of the contribution of soil carbon to paddy rice and soil to rice carbon transfer factor using natural abundances of stable carbon isotopes

    International Nuclear Information System (INIS)

    To obtain the soil-to-rice transfer factor (TF) of carbon-14 (14C), TF of stable carbon was estimated by measuring stable carbon isotope ratios (13C/12C) and total C concentrations in rice grain and associated soil samples collected throughout Japan. Carbon isotope ratios were reported in terms of a δ13C value. By comparing δ13C values for brown rice, white rice and bran, we concluded that white rice was the most suitable part to be used for this estimation because it reflects products from photosynthesis. The δ13C values for white rice and soil showed a weak correlation which may indicate a potential carbon supply from soil to rice. Thus we took a statistical approach to estimate the percent of soil-origin carbon in rice plants. We found that a maximum 1.6% of total carbon in rice plants was from soil under the reasonable assumptions that the carbon fractionation by paddy rice was -19 per mille and δ13C of atmospheric CO2 was -8 per mille. Maximum TF value ranged from 0.05 to 0.5 for stable carbon and the value would also be applicable for 14C because the carbon fractionation effect for 14C would be negligible in carbon transfer. (author)

  17. Interaction forces between waterborne bacteria and activated carbon particles.

    Science.gov (United States)

    Busscher, Henk J; Dijkstra, Rene J B; Langworthy, Don E; Collias, Dimitris I; Bjorkquist, David W; Mitchell, Michael D; Van der Mei, Henny C

    2008-06-01

    Activated carbons remove waterborne bacteria from potable water systems through attractive Lifshitz-van der Waals forces despite electrostatic repulsion between negatively charged cells and carbon surfaces. In this paper we quantify the interaction forces between bacteria with negatively and positively charged, mesoporous wood-based carbons, as well as with a microporous coconut carbon. To this end, we glued carbon particles to the cantilever of an atomic force microscope and measured the interaction forces upon approach and retraction of thus made tips. Waterborne Raoultella terrigena and Escherichia coli adhered weakly (1-2 nN) to different activated carbon particles, and the main difference between the activated carbons was the percentage of curves with attractive sites revealed upon traversing of a carbon particle through the bacterial EPS layer. The percentage of curves showing adhesion forces upon retraction varied between 21% and 69%, and was highest for R. terrigena with positively charged carbon (66%) and a coconut carbon (69%). Macroscopic bacterial removal by the mesoporous carbon particles increased with increasing percentages of attractive sites revealed upon traversing a carbon particle through the outer bacterial surface layer. PMID:18405910

  18. The Circumstellar Shell of the Post-Asymptotic Giant Branch Star HD 56126: 12C12C/12C13C Isotope Ratio and 12C16O Column Density

    Science.gov (United States)

    Bakker, Eric J.; Lambert, David L.

    1998-11-01

    We have made the first detection of circumstellar absorption lines of the 12C13C A 1Πu-X 1Σ+g (Phillips) system 1-0 band and the 12C16O X 1Σ+ first-overtone 2-0 band in the spectrum of the post-AGB star HD 56126 (IRAS 07134+1005). All current detections of circumstellar molecular absorption lines toward HD 56126 (12C2, 12C13C, 12C14N, 13C14N, and 12C16O) yield the same heliocentric velocity of VCSE = 77.6 +/- 0.4 km s-1. The 12C2, 12C13C, and 12C16O lines give rotational temperatures and integrated column densities of Trot = 328 +/- 37 K, log Nint = 15.34 +/- 0.10 cm-2, Trot = 256 +/- 30 K, log Nint = 13.79 +/- 0.12 cm-2, and Trot = 51 +/- 37 K, log Nint = 18.12 +/- 0.13 cm-2, respectively. The rotational temperatures are lower for molecules with a higher permanent dipole moment. Derived relative column densities ratios are 12C2/12C13C = 36 +/- 13 and 12C16O/(12C2 + 12C13C) = 606 +/- 230. Combined with data from a previous paper, we find relative column densities of 12C16O/(12C14N + 13C14N) = 475 +/- 175 and 12C14N/13C14N = 38 +/- 2. Under chemical equilibrium conditions, 12C13C is formed twice as easily as 12C2. The isotopic exchange reaction for 12C2 is too slow to significantly alter the 12C2/12C13C ratio, and the 12C2 to 12C13C ratio is a good measure of half the carbon isotope ratio: 12C/13C = 2 × 12C2/12C13C = 72 +/- 26. This is in agreement with our prediction that the isotopic exchange reaction for 12C14N is efficient and our observation in Paper III of 12C14N/13C14N = 38 +/- 2. A fit of the C2 excitation model of van Dishoeck & Black to the relative population distribution of C2 yields nc σ/I = 3.3 +/- 1.0 × 10-14. At r ~= 1016 cm, this translates into nc = 1.7 × 107 cm-3 and Ṁ~=2.5×10-4 M⊙ yr-1.

  19. 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.

  20. Calculating Young's modulus for a carbon nanotube

    Science.gov (United States)

    Alzubi, Feras; Cosby, Ronald

    2008-10-01

    Young's modulus for an armchair single-wall carbon nanotube was calculated using an atomistic approach and density functional theory (DFT). Atomic forces and total energies for strained carbon nanotube segments were computed using Atomistix's Virtual NanoLab (VNL) and ToolKit (ATK) software. For a maximum strain of one percent, elastic moduli were calculated using both force-strain and energy-strain data. The average values found for Young's modulus were in the range 1.2 to 3.9 TPa depending on the cross-sectional area taken for the carbon nanotube, consideration of Poisson's ratio, and the calculation method used. Three possible choices of cross-sectional area for the carbon nanotube are discussed and parameter and convergence tests for the DFT computations are described.

  1. Extended Carbon Cognition as a Machine

    DEFF Research Database (Denmark)

    Lippert, Ingmar

    2011-01-01

    By way of exploring ethnographic data on carbon construction practices by agents of ecological modernisation in a multinational corporation, this paper seeks to problematise the distributed and heterogeneous intelligence assembled by human and non-humans to make intelligible their carbon footprint....... Grounded in ethnographic fieldwork at a leading multinational in the financial services sector over a period of more than 12 months, I focus on everyday work practices as taking place in a capitalist context. It is through practical work that the presences of carbon emissions are imagined and brought into...... being. Thus, carbon emerges as co-constituted by thought. I will focus on instances in which the corporate machinery, i.e. automated thought, had to be supplemented by immediate human practices of 1) thinking themselves, 2) organising materials to think through and 3) ordering others to think. At...

  2. Carbon-cluster mass calibration at SHIPTRAP

    International Nuclear Information System (INIS)

    A carbon-cluster ion source has been installed and tested at SHIPTRAP, the Penning-trap mass spectrometer for precision mass measurements of heavy elements at GSI (Darmstadt, Germany). Carbon-cluster ions 12Cn+, 5 ≤ n ≤ 23, were produced by laser-induced desorption and ionization from a carbon sample. They were tested for the first time as reference ions in an on-line mass measurement of the radionuclides 144Dy, 146Dy and 147Ho. In addition, carbon clusters of various sizes were used for an investigation of the systematic uncertainty of SHIPTRAP covering a mass range from 84 u to 240 u. The mass-dependent uncertainty was found to be negligible for the case of (m - m(ref)) -8 was revealed. (authors)

  3. Carbon nanotube cathode with capping carbon nanosheet

    Science.gov (United States)

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

    2013-10-01

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

  4. 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 ...

  5. 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

  6. 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...

  7. 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 ...

  8. Sodium carbonate poisoning

    Science.gov (United States)

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

  9. 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...

  10. Carbon Monoxide Information Center

    Medline Plus

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

  11. 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 ...

  12. Soil Organic Carbon Stock

    Data.gov (United States)

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

  13. Carbon Monoxide Information Center

    Medline Plus

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

  14. 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 ...

  15. 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.

  16. Carbon dioxide-guided angioplasty

    International Nuclear Information System (INIS)

    Revascularization procedures are frequently necessary in patients with severe peripheral vascular disease and renal insufficiency (often coexistent with diabetes mellitus). This paper examines the use of carbon dioxide as the contrast agent in percutaneous revascularization procedures (balloon angioplasty). Over the past 10 months, our protocol has used CO2 as the contrast agent for balloon angioplasty in a select group of patients (n = 12) with peripheral vascular disease and renal insufficiency. Some had coexistent diabetes mellitus. With digital subtraction angiography, CO2 was the only contrast agent used during revascularization. Pressure gradients were obtained in appropriate patients

  17. 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...

  18. 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.

  19. 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...

  20. 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.

  1. 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…

  2. 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.

  3. 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.

  4. 75 FR 60814 - Carbon Steel Butt-Weld Pipe Fittings From Brazil, China, Japan, Taiwan, and Thailand

    Science.gov (United States)

    2010-10-01

    ... Investigation No. F.R. cite 12/17/86 Carbon steel butt- 731-TA-308 51 FR 45152. weld pipe fittings/ Brazil. 12/17/86 Carbon steel butt- 731-TA-310 51 FR 45152. weld pipe fittings/ Taiwan. 2/10/87 Carbon steel butt- 731-TA-309 52 FR 4167. weld pipe fittings/ Japan. 7/6/92 Carbon steel butt- 731-TA-520 57...

  5. 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.

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

    DEFF Research Database (Denmark)

    Arndt, Thomas Channing

    2014-01-01

    South Africa is considering introducing a carbon tax to reduce greenhouse gas emissions. Following a discussion of the motivations for considering a carbon tax, we evaluate potential impacts using a dynamic economywide model linked to an energy sector model including a detailed evaluation of border...... 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...

  7. Catalytic removal of carbon monoxide over carbon supported palladium catalyst

    International Nuclear Information System (INIS)

    Highlights: ► Carbon supported palladium (Pd/C) catalyst was prepared. ► Catalytic removal of CO over Pd/C catalyst was studied under dynamic conditions. ► Effects of Pd %, CO conc., humidity, GHSV and reaction environment were studied. - Abstract: Carbon supported palladium (Pd/C) catalyst was prepared by impregnation of palladium chloride using incipient wetness technique, which was followed by liquid phase reduction with formaldehyde. Thereafter, Pd/C catalyst was characterized using X-ray diffractometery, scanning electron microscopy, atomic absorption spectroscopy, thermo gravimetry, differential scanning calorimetry and surface characterization techniques. Catalytic removal of carbon monoxide (CO) over Pd/C catalyst was studied under dynamic conditions. Pd/C catalyst was found to be continuously converting CO to CO2 through the catalyzed reaction, i.e., CO + 1/2O2 → CO2. Pd/C catalyst provided excellent protection against CO. Effects of palladium wt%, CO concentration, humidity, space velocity and reaction environment were also studied on the breakthrough behavior of CO.

  8. 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.

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

    Science.gov (United States)

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

    2012-12-01

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

  10. Activated carbons and gold

    International Nuclear Information System (INIS)

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

  11. Corrosion rate of carbon steel in NS tank water

    International Nuclear Information System (INIS)

    Neutron shield tank (NST) is an open tank 12.5 meters in height and 12 meters dia constructed around the research reactor. It is filled with water to (i) provide shielding from the neutron radiation, (ii) to remove the heat from the Pressure suppression system during LOCA and (iii) to act as a heat sink. NST is made of IS2062 carbon steel and it contains the stainless steel tanks, CS support structures, forged carbon steel gas cylinders, steel containment and its supports and emergency cooling down system condensers made of ASTM 350 grade LF2 carbon steel. All the equipments/systems located inside NST are painted with epoxy paint. NST is filled up 12 meters ie with 1200 m3 of water. The water chemistry parameters and microbiological parameters and corrosion rate of carbon steel materials in NST water at various water chemistry and various depths are discussed in the paper. (author)

  12. 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: ...

  13. Vitamin B12

    Science.gov (United States)

    ... prevent or treat dementia. Energy and athletic performance Advertisements often promote vitamin B12 supplements as a way ... 24, 2011 Share This Page: E-mail Twitter Facebook Google+ Pinterest Contact Us | Accessibility | Site Policies | Disclaimer | ...

  14. 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

  15. 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...

  16. 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°.

  17. 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.

  18. 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.

  19. 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...

  20. 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.

  1. 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

  2. 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)

  3. Study on the Cycling Performance of Li4Ti5O12 Electrode in the Ionic Liquid Electrolytes Containing an Additive

    International Nuclear Information System (INIS)

    The cycling behavior of Li4Ti5O12 electrode in the ionic liquid (IL)-based electrolytes containing 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide and a small amount of additive (vinylene carbonate, ethylene carbonate, fluoroethylene carbonate) was investigated. The Li4Ti5O12 electrode in the IL electrolyte with an additive exhibited reversible cycling behavior with good capacity retention. Electrochemical impedance spectroscopy and FTIR studies revealed that an electrochemically stable solid electrolyte interphase was formed on the Li4Ti5O12 electrode in the presence of vinylene carbonate and ethylene carbonate during cycling

  4. 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

  5. 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...

  6. 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...

  7. Disintegration of Carbon Dioxide Molecules in a Microwave Plasma Torch

    Science.gov (United States)

    Kwak, Hyoung S.; Uhm, Han S.; Hong, Yong C.; Choi, Eun H.

    2015-12-01

    A pure carbon dioxide torch is generated by making use of 2.45 GHz microwave. Carbon dioxide gas becomes the working gas and produces a stable carbon dioxide torch. The torch volume is almost linearly proportional to the microwave power. Temperature of the torch flame is measured by making use of optical spectroscopy and thermocouple. Two distinctive regions are exhibited, a bright, whitish region of high-temperature zone and a bluish, dimmer region of relatively low-temperature zone. Study of carbon dioxide disintegration and gas temperature effects on the molecular fraction characteristics in the carbon dioxide plasma of a microwave plasma torch under atmospheric pressure is carried out. An analytical investigation of carbon dioxide disintegration indicates that substantial fraction of carbon dioxide molecules disintegrate and form other compounds in the torch. For example, the normalized particle densities at center of plasma are given by nCO2/nN = 6.12 × 10-3, nCO/nN = 0.13, nC/nN = 0.24, nO/nN = 0.61, nC2/nN = 8.32 × 10-7, nO2/nN = 5.39 × 10-5, where nCO2, nCO, nC, nO, nC2, and nO2 are carbon dioxide, carbon monoxide, carbon and oxygen atom, carbon and oxygen molecule densities, respectively. nN is the neutral particle density. Emission profiles of the oxygen and carbon atom radicals and the carbon monoxide molecules confirm the theoretical predictions of carbon dioxide disintegration in the torch.

  8. 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

  9. 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

  10. 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...

  11. 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.

  12. Carbon-negative biofuels

    International Nuclear Information System (INIS)

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

  13. Carbon Activation Diagnostic for Tertiary Neutron Measurements

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-03-28

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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Carbon monoxide poisoning

    OpenAIRE

    Dolan, Michael C.

    1985-01-01

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

  20. The carbon dioxide cycle

    Science.gov (United States)

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

    2005-01-01

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

  1. Carbon monoxide poisoning (acute)

    OpenAIRE

    Olson, Kent; Smollin, Craig

    2010-01-01

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

  2. Carbon nanotubes decorating methods

    OpenAIRE

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

    2013-01-01

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

  3. Functionalization of Carbon Nanotubes

    OpenAIRE

    Abraham, Jürgen

    2005-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Hirabayashi, Daisuke; Enokida, Youichi [Graduate School of Engineering, Nagoya University, 1 Furo-cho, Chikusa-ku, Nagoya-shi, Aichi-ken, 464-8603 (Japan); Sawada, Kayo [EcoTopia Science Institute, Nagoya University, 1 Furo-cho, Chikusa-ku, Nagoya-shi, Aichi-ken, 464-8603 (Japan); Hertz, Audrey; Charton, Frederic [CEA, DEN, Marcoule, DTCD/SPDE/L2ED, BP 17171, F-30207 Bagnols-sur-Ceze (France); Frizon, Fabien [CEA, DEN, Marcoule, DTCD/SPDE/LFSM, BP 17171, F-30207 Bagnols-sur-Ceze (France); Brouno, Fournel [CEA, DEN, Marcoule, DTCD, BP 17171, F-30207 Bagnols-sur-Ceze (France)

    2012-07-01

    Carbonation of cement-based waste forms using a supercritical carbon dioxide (SCCO{sub 2}) is a developing technology for the waste immobilization of radioactive and non-radioactive wastes. However, the detail carbonation behaviors of cement matrices under the SCCO{sub 2} 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){sub 2}), ettringite (Ca{sub 6}Al{sub 2}(SO{sub 4}){sub 3}(OH){sub 12}.26H{sub 2}O), and calcium silicate hydrate (n CaO---m SiO{sub 2} ---x H{sub 2}O), 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 (CaCO{sub 3}) in all cases. However, the behaviors of H{sub 2}O and CO{sub 2} content were quietly different: Portlandite was most reactive for carbonation under SCCO{sub 2} conditions, and the CO{sub 2} 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 SCCO{sub 2} conditions. Therefore, a part of ettringite remained and formed similar phases after the ettringite carbonation. The CO{sub 2} 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 SCCO{sub 2

  5. 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

  6. 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)

  7. Carbon Trading. Literature Overview

    International Nuclear Information System (INIS)

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

  8. 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

  9. Global Carbon Cycle

    OpenAIRE

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

    1999-01-01

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

  10. Changing global carbon cycle

    International Nuclear Information System (INIS)

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

  11. 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)

  12. 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).

  13. 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.

  14. 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 ...

  15. 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

  16. 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.

  17. Heavy duty piezoresistivity induced strain sensing natural rubber/carbon black nanocomposites reinforced with different carbon nanofillers

    Science.gov (United States)

    He, Qingliang; Yuan, Tingting; Zhang, Xi; Guo, Shimei; Liu, Jingjing; Liu, Jiurong; Liu, Xinyu; Sun, Luyi; Wei, Suying; Guo, Zhanhu

    2014-09-01

    Durable piezoresistive effects of natural rubber nanocomposites have been demonstrated, i.e., with stable and reversible electrical resistance change within the tested 3000 cycles upon applying a small compressive strain (˜16.7%) under a relatively high frequency (0.5 Hz, 2 s/cycle). This unique function was achieved for the first time by combining carbon nanotubes and carbon nanofibers with natural rubber composites pretreated with carbon black. Even though the combination of different carbon nanomaterials, such as graphene nanosheets and carbon nanotubes, can improve the dispersion quality of both the nanostructures in solution or in polymer matrices, this type of synergistic effect between carbon nanotubes and carbon nanofibers in producing stable and reversible piezoresistive effect has been rarely reported. Besides, the strong reinforcement (compressive stress at a maximum strain of 16.7% was increased from 12.6 for untreated to 18.5 MPa for the natural rubber/carbon black composites treated with a combination of 1.0 wt% carbon nanotubes and 1.0 wt% carbon nanofibers) makes the as-prepared composites promising for heavy duty pressure sensors, i.e., healthy motion monitoring of industrial machinery vibrations.

  18. 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.

  19. 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.

  20. 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...

  1. 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

  2. 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

  3. 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.

  4. Carbon Stock and Carbon Cycle of Wetland Ecosystem

    OpenAIRE

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

    2014-01-01

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

  5. 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 ...

  6. 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 ...

  7. 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

  8. 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

  9. Seeing the Carbon Cycle

    Science.gov (United States)

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

    2006-01-01

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

  10. The carbon cycle revisited

    Science.gov (United States)

    Bolin, Bert; Fung, Inez

    1992-01-01

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

  11. 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...

  12. 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.

  13. Carbon Monoxide Poisoning

    Science.gov (United States)

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

  14. 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...

  15. 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.)…

  16. 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,

  17. 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

  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. Welding of high manganese- and carbon steels

    International Nuclear Information System (INIS)

    Technology and conditions of welding of high manganese and carbon steel by a resistance welding technique using an intermediate part are developed. Austenitic chromium-nickel 12Kh18N10T steel is chosen as a material of the intermediate part. The recommended welding conditions insure a high quality of the weld joint in terms of metal structure and its mechanical properties. It is the basic metal of the joint that fractures under mechanical testing

  20. 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...

  1. Water and Carbon as Creators of Imbalances in Nature

    Science.gov (United States)

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

    2012-12-01

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

  2. Chernobyl, 12 years later

    International Nuclear Information System (INIS)

    This report draws an account of the consequences of Chernobyl accident 12 years after the disaster. It is made up of 7 chapters whose titles are: 1) Some figures about Chernobyl accident, 2) The Chernobyl nuclear power plant, 3)Sanitary consequences of Chernobyl accident, 4) The management of contaminated lands, 5) The impact in France of Chernobyl fallout, 6) The Franco-German cooperation, and 7) Glossary

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. Same Exposure, Various Clinical Pictures: The Carbon Monoxide Enigma

    Directory of Open Access Journals (Sweden)

    Musa Salmanoglu

    2013-02-01

    Full Text Available -Children and adolescents exposed to the same source of carbon monoxide have been shown to demonstrate different clinical pictures (1,2. The same condition probably may be extrapolated between children with varying ages and hence lung surface areas. Smaller children will receive larger doses of carbon monoxide, because they have greater lung surface area/body weight ratios and increased minute volumes/weight ratios. As carbon monoxide accumulation is expected to be more significant nearer to the ground, another explanation for varying clinical pictures in poisoning events may be the different level of sleeping positions of the casualties. Herein, we report a cluster poisoning of carbon monoxide affecting 5 children from the same family at the same time but in different clinical pictures. [TAF Prev Med Bull 2013; 12(1.000: 118-118

  8. Carbon Dioxide in Exoplanetary Atmospheres: Rarely Dominant Compared to Carbon Monoxide and Water in Hot, Hydrogen-dominated Atmospheres

    Science.gov (United States)

    Heng, Kevin; Lyons, James R.

    2016-02-01

    We present a comprehensive study of the abundance of carbon dioxide in exoplanetary atmospheres in hot, hydrogen-dominated atmospheres. We construct novel analytical models of systems in chemical equilibrium that include carbon monoxide, carbon dioxide, water, methane and acetylene and relate the equilibrium constants of the chemical reactions to temperature and pressure via the tabulated Gibbs free energies. We prove that such chemical systems may be described by a quintic equation for the mixing ratio of methane. By examining the abundances of these molecules across a broad range of temperatures (spanning equilibrium temperatures from 600 to 2500 K), pressures (via temperature-pressure profiles that explore albedo and opacity variations) and carbon-to-oxygen ratios, we conclude that carbon dioxide is subdominant compared to carbon monoxide and water. Atmospheric mixing does not alter this conclusion if carbon dioxide is subdominant everywhere in the atmosphere. Carbon dioxide and carbon monoxide may attain comparable abundances if the metallicity is greatly enhanced, but this property is negated by temperatures above 1000 K. For hydrogen-dominated atmospheres, our generic result has the implication that retrieval studies may wish to set the subdominance of carbon dioxide as a prior of the calculation and not let its abundance completely roam free as a fitting parameter, because it directly affects the inferred value of the carbon-to-oxygen ratio and may produce unphysical conclusions. We discuss the relevance of these implications for the hot Jupiter WASP-12b and suggest that some of the previous results are chemically impossible. The relative abundance of carbon dioxide to acetylene is potentially a sensitive diagnostic of the carbon-to-oxygen ratio.

  9. 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.

  10. 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.

  11. 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.

  12. How does the carbon fusion reaction happen in stars?

    International Nuclear Information System (INIS)

    The 12C + 12C fusion reaction is one of the most important reactions in the stellar evolution. Due to its complicated reaction mechanism, there is great uncertainty in the reaction rate which limits our understanding of various stellar objects, such as massive stellar evolution, explosions on neutron stars, and supernovae from accreting white dwarf stars. In this paper, I will review the challenges in the study of carbon burning. I will also report recent results from our studies: 1) an upper limit for the 12C + 12C fusion cross sections, 2) measurement of the 12C + 12C at deep sub-barrier energies, and 3) a new measurement of the 12C(12C, n) reaction. The outlook for the studies of the astrophysical heavy-ion fusion reactions will also be presented

  13. Climate policy and dependence on traded carbon

    Science.gov (United States)

    Andrew, Robbie M.; Davis, Steven J.; Peters, Glen P.

    2013-09-01

    A growing number of countries regulate carbon dioxide (CO2) emissions occurring within their borders, but due to rapid growth in international trade, the products consumed in many of the same countries increasingly rely on coal, oil and gas extracted and burned in other countries where CO2 is not regulated. As a consequence, existing national and regional climate policies may be growing less effective every year. Furthermore, countries that are dependent on imported products or fossil fuels are more exposed to energy and climate policies in other countries. We show that the combined international trade in carbon (as fossil fuels and also embodied in products) increased from 12.3 GtCO2 (55% of global emissions) in 1997 to 17.6 GtCO2 (60%) in 2007 (growing at 3.7% yr-1). Within this, trade in fossil fuels was larger (10.8 GtCO2 in 2007) than trade in embodied carbon (6.9 GtCO2), but the latter grew faster (4.6% yr-1 compared with 3.1% yr-1 for fuels). Most major economies demonstrate increased dependence on traded carbon, either as exports or as imports. Because energy is increasingly embodied in internationally traded products, both as fossil fuels and as products, energy and climate policies in other countries may weaken domestic climate policy via carbon leakage and mask energy security issues.

  14. 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 Section 925.12 Banks and Banking FEDERAL HOUSING FINANCE BOARD FEDERAL HOME LOAN BANK MEMBERS AND HOUSING ASSOCIATES MEMBERS OF THE BANKS Eligibility Requirements § 925.12 Character of management requirement....

  15. 12 CFR 1710.12 - Committees of board of directors.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Committees of board of directors. 1710.12 Section 1710.12 Banks and Banking OFFICE OF FEDERAL HOUSING ENTERPRISE OVERSIGHT, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT SAFETY AND SOUNDNESS CORPORATE GOVERNANCE Corporate Practices and Procedures § 1710.12 Committees of board of directors....

  16. Revisiting Zinc Coordination in Human Carbonic Anhydrase II

    OpenAIRE

    Song, He; Wilson, David L.; Farquhar, Erik R.; Lewis, Edwin A.; Emerson, Joseph P.

    2012-01-01

    Carbonic anhydrase (CA) is a well-studied, zinc-dependent metalloenzyme that catalyzes the hydrolysis of carbon dioxide to the bicarbonate ion. The apo-form of CA (apoCA) is relatively easy to generate, and the reconstitution of the human erythrocyte CA has been initially investigated. In the past, these studies have continually relied on equilibrium dialysis measurements to ascertain an extremely strong association constant (Ka ~ 1.2×1012) for Zn2+. However, new reactivity data and isotherma...

  17. 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...

  18. Carbon monoxide and exercise tolerance in chronic bronchitis and emphysema.

    OpenAIRE

    Calverley, P. M.; Leggett, R J; Flenley, D C

    1981-01-01

    The effects of carbon monoxide on exercise tolerance as assessed by the distance walked in 12 minutes were studied in 15 patients with severe chronic bronchitis and emphysema (mean forced expiratory volume in one second 0.56 1, mean forced vital capacity 1.54 1). Each subject walked breathing air and oxygen before and after exposure to sufficient carbon monoxide to raise their venous carboxyhaemoglobin concentration by 9%. There was a significant reduction in the walking distance when the pat...

  19. 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.

  20. 77 FR 64478 - Circular Welded Carbon-Quality Steel Pipe From India: Final Determination of Sales at Less Than...

    Science.gov (United States)

    2012-10-22

    ... Preliminary Determination, 77 FR at 32562-63. \\3\\ See Circular Welded Carbon-Quality Steel Pipe From India...; Certain Welded Carbon Steel Standard Pipes and Tubes From India, 51 FR 17384 (May 12, 1986). Therefore... International Trade Administration Circular Welded Carbon-Quality Steel Pipe From India: Final Determination...

  1. 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...

  2. 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.

  3. 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.

  4. Mechanical Testing of Carbon-Carbon Composite for Applications in Human Spine Surgery in the Form of Intervertebral Cages

    Czech Academy of Sciences Publication Activity Database

    Sochor, M.; Balík, Karel; Suchý, Tomáš; Sedláček, R.; Tichý, P.

    Praha : Ústav struktury a mechaniky hornin AV ČR, 2003 - (Kolář, F.), s. - [Czech-Polish Workshop on Testing of Composite Materials. Praha (CZ), 11.09.2003-12.09.2003] R&D Projects: GA ČR GA106/00/1407 Institutional research plan: CEZ:AV0Z3046908 Keywords : carbon-carbon composite * mechanical testing * biocompatibility Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass

  5. Adhesion, differentiation and immune activation of human osteogenic cells in cultures on carbon-fibre reinforced carbon composites

    Czech Academy of Sciences Publication Activity Database

    Bačáková, Lucie; Starý, V.; Glogar, Petr; Lisá, Věra

    2003-01-01

    Roč. 6, - (2003), s. 8-9. ISSN 1429-7248. [Konferencja Naukowa "Biomaterialy w medycynie i weterynarii" /13./. Rytro, 09.10.2003-12.10.2003] R&D Projects: GA MŠk OC 527.130 Institutional research plan: CEZ:AV0Z3046908; CEZ:AV0Z5011922 Keywords : carbon-carbon composites * surface properties * bone tissue engineering Subject RIV: JI - Composite Materials

  6. 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.

  7. 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.

  8. Radioactively labelled vitamin B12

    International Nuclear Information System (INIS)

    The application concerns the manufacture of radioactive forms of vitamin B-12 in which the cobalt atom present in the vitamin B-12 molecule is replaced with a radioactive isotope of cobalt, usually cobalt-57 or cobalt-58. Such radioactive forms of B-12 are used extensively in the diagnosis of B-12 deficiency states

  9. 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)

  10. 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).

  11. 77 FR 75972 - Foreign-Trade Zone 148-Knoxville, Tennessee, Toho Tenax America, Inc., Subzone 148C (Carbon Fiber...

    Science.gov (United States)

    2012-12-26

    ... 148C (Carbon Fiber Manufacturing Authority); Extension of Comment Period on New Evidence The comment... preliminary recommendation not to authorize TTA to manufacture carbon fiber for the U.S. market at this time... comment (77 FR 73978, 12/12/2012). Rebuttal comments may be submitted during the subsequent 15-day...

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

    DEFF Research Database (Denmark)

    Sørensen, Lasse Holst; Paul, E. A.

    1971-01-01

    Carbon-14-labelled acetate was added to a heavy clay soil of pH 7.6 to study the transformation of acetate carbon into carbohydrate and amino acid metabolites during decomposition. The acetate was totally metabolized after 6 days of incubation at 25°C when 70% of the labelled carbon had been...... evolved as CO2. Maximum incorporation of trace-C into the various organic fractions was observed after 4 days when 19% of residual, labelled carbon in the soil was located in carbohydrates, 29 % in amino acids and 21 % in the insoluble residue of the soil. The curves showing the amounts of labelled carbon...... days of incubation, 2.2% of the labelled carbon originally added to the soil was located in carbohydrate metabolites, 7% in amino acid metabolites and 5% in the insoluble residue. The carbon in these fractions accounted for 77% of the total, residual, labelled carbon in the soil; 12% in carbohydrates...

  13. Caffeine content of prepackaged national-brand and private-label carbonated beverages.

    Science.gov (United States)

    Chou, K-H; Bell, L N

    2007-08-01

    Caffeine is a well-known stimulant that is added as an ingredient to various carbonated soft drinks. Due to its stimulatory and other physiological effects, individuals desire to know the exact amount of caffeine consumed from these beverages. This study analyzed the caffeine contents of 56 national-brand and 75 private-label store-brand carbonated beverages using high-performance liquid chromatography. Caffeine contents ranged from 4.9 mg/12 oz (IGA Cola) to 74 mg/12 oz (Vault Zero). Some of the more common national-brand carbonated beverages analyzed in this study with their caffeine contents were Coca-Cola (33.9 mg/12 oz), Diet Coke (46.3 mg/12 oz), Pepsi (38.9 mg/12 oz), Diet Pepsi (36.7 mg/12 oz), Dr Pepper (42.6 mg/12 oz), Diet Dr Pepper (44.1 mg/12 oz), Mountain Dew (54.8 mg/12 oz), and Diet Mountain Dew (55.2 mg/12 oz). The Wal-Mart store-brand beverages with their caffeine contents were Sam's Cola (12.7 mg/12 oz), Sam's Diet Cola (13.3 mg/12 oz), Dr Thunder (30.6 mg/12 oz), Diet Dr Thunder (29.9 mg/12 oz), and Mountain Lightning (46.5 mg/12 oz). Beverages from 14 other stores were also analyzed. Most store-brand carbonated beverages were found to contain less caffeine than their national-brand counterparts. The wide range of caffeine contents in carbonated beverages indicates that consumers would benefit from the placement of caffeine values on food labels. PMID:17995675

  14. Hydrogen adsorption in doped porous carbons

    International Nuclear Information System (INIS)

    Full text of publication follows: Hydrogen is a clean fuel that will be used in automotive transport when the problem of storage will be solved. The difficulties of H2 storage (available space, security and performance, etc...) require a material that can store 5 weight % of hydrogen. Research is focused on new materials that can assume the constraints imposed by the automotive applications. Among these materials, the nano-structured carbons (nano-fibers and single walled carbon nano-tubes) were claimed to be promising by numerous authors [1-3]. The more promising carbon materials for hydrogen adsorption are those having micropores (i. e. single walled carbon nano-tubes and activated carbon), for which the energy of sorption of hydrogen molecules is theoretically higher [7- 8]. Presently, the best performance of hydrogen adsorption was found in super-activated micro-porous carbons sorbing 5 weight % at 77 K, and almost 0.5 % at room temperature and 6 MPa [9]. Up to now, the performance of these materials can still be improved as the known mechanism of sorption in these carbon materials: physisorption controlled by Van der Waals attractive forces through London interaction is efficient at cryogenic temperatures (77 K) where the interaction between adsorbent and adsorbate becomes stronger. One way to improve the attractive interaction between adsorbent and molecule is to increase the forces due to the interaction of electrical field and induced dipole of the molecule. This can be theoretically tailored in carbon materials through the electron charge transfer by electron donors who can provide an increase in the electrical field al the surface of the adsorbent. Then, the doping of carbon substrates, appearing to be a promising method to increase the energy of adsorption has been proposed in recent papers as a solution to obtain good hydrogen adsorption properties at appropriate temperatures close to room temperatures [10-12]. Thus, we have studied the adsorption

  15. Hydrogen adsorption in doped porous carbons

    International Nuclear Information System (INIS)

    Full text of publication follows: Hydrogen is a clean fuel that will be used in automotive transport when the problem of storage will be solved. The difficulties of H2 storage (available space, security and performance, etc...) require a material that can store 5 weight % of hydrogen. Research is focused on new materials that can assume the constraints imposed by the automotive applications. Among these materials, the nano-structured carbons (nano-fibers and single walled carbon nano-tubes) were claimed to be promising by numerous authors [1-3]. The more promising carbon materials for hydrogen adsorption are those having micropores (i. e. single walled carbon nano-tubes and activated carbon), for which the energy of sorption of hydrogen molecules is theoretically higher [7-8]. Presently, the best performance of hydrogen adsorption was found in super-activated microporous carbons sorbing 5 weight % at 77 K, and almost 0.5 % at room temperature and 6 MPa [9]. Up to now, the performance of these materials can still be improved as the known mechanism of sorption in these carbon materials: physi-sorption controlled by Van der Waals attractive forces through London interaction is efficient at cryogenic temperatures (77 K) where the interaction between adsorbent and adsorbate becomes stronger. One way to improve the attractive interaction between adsorbent and molecule is to increase the forces due to the interaction of electrical field and induced dipole of the molecule. This can be theoretically tailored in carbon materials through the electron charge transfer by electron donors who can provide an increase in the electrical field at the surface of the adsorbent. Then, the doping of carbon substrates, appearing to be a promising method to increase the energy of adsorption has been proposed in recent papers as a solution to obtain good hydrogen adsorption properties at appropriate temperatures close to room temperatures [10-12]. Thus, we have studied the adsorption

  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., 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 fractionation

  17. 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

  18. 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

  19. 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...

  20. A novel carbon fiber based porous carbon monolith

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-07-01

    A novel porous carbon material based on carbon fibers has been developed. The material, when activated, develops a significant micro- or mesopore volume dependent upon the carbon fiber type utilized (isotropic pitch or polyacrylonitrile). The materials will find applications in the field of fluid separations or as a catalyst support. Here, the manufacture and characterization of our porous carbon monoliths are described.

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

    Science.gov (United States)

    2010-10-01

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

  2. 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.

  3. 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...

  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 1994-10-12 to 1994-11-10 (NODC Accession 0113555)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113555 includes chemical, discrete sample, physical and profile data collected from HUDSON in the North Atlantic Ocean from 1994-10-12 to 1994-11-10...

  5. 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...

  6. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the DISCOVERY in the Indian Ocean from 2004-12-13 to 2005-01-21 (NODC Accession 0113538)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113538 includes chemical, discrete sample, physical and profile data collected from DISCOVERY in the Indian Ocean from 2004-12-13 to 2005-01-21 and...

  7. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the DISCOVERY in the Indian Ocean from 2004-11-03 to 2004-12-10 (NODC Accession 0113537)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113537 includes chemical, discrete sample, physical and profile data collected from DISCOVERY in the Indian Ocean from 2004-11-03 to 2004-12-10 and...

  8. 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....

  9. 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...

  10. 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...

  11. Dissolved inorganic carbon, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the TYRO in the North Atlantic Ocean from 1990-07-01 to 1990-07-12 (NODC Accession 0113602)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113602 includes chemical, discrete sample, physical and profile data collected from TYRO in the North Atlantic Ocean from 1990-07-01 to 1990-07-12...

  12. 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...

  13. 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...

  14. Dissolved inorganic carbon, 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 1989-06-12 to 1989-07-09 (NODC Accession 0113531)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113531 includes chemical, discrete sample, physical and profile data collected from DISCOVERY in the North Atlantic Ocean from 1989-06-12 to...

  15. 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...

  16. Carbon Irradiated SI-GaAs for Photoconductive THz Detection

    OpenAIRE

    Singh, Abhishek; Pal, Sanjoy; Surdi, Harshad; Prabhu, S. S.; S., Mathimalar; Nanal, Vandana; Pillay, R. G.; Dohler, G. H.

    2014-01-01

    We report here a photoconductive material for THz generation and detection with sub-picosecond carrier lifetime made by C12 (Carbon) irradiation on commercially available semi-insulating (SI) GaAs. We are able to reduce the carrier lifetime of SI-GaAs down to sub-picosecond by irradiating it with various irradiation dosages of Carbon (C12) ions. With an increase of the irradiation dose from ~1012 /cm2 to ~1015 /cm2 the carrier lifetime of SI-GaAs monotonously decreases to 0.55 picosecond, res...

  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. 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

  20. Draw out Carbon Nanotube from Liquid Carbon

    OpenAIRE

    ZHANG, SHUANG; Hoshi, Takeo; Fujiwara, Takeo

    2006-01-01

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

  1. 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.

  2. 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.)

  3. 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 ...

  4. Carbon diffusion in niobium

    International Nuclear Information System (INIS)

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

  5. 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.

  6. 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.

  7. 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, ...

  8. 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...

  9. 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.

  10. 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.

  11. Carbon Monoxide Information Center

    Medline Plus

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

  12. Carbon Monoxide Information Center

    Medline Plus

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

  13. 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 ...

  14. Carbon Monoxide Information Center

    Medline Plus

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

  15. Carbon Monoxide Information Center

    Medline Plus

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

  16. Carbon Monoxide Information Center

    Medline Plus

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

  17. Understanding carbon compensation

    International Nuclear Information System (INIS)

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

  18. Carbon Monoxide Information Center

    Medline Plus

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

  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. 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.

  1. Carbon Footprint of Thermowood

    OpenAIRE

    Nordlund, Teemu

    2015-01-01

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

  2. 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)

  3. 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; Ulven, T; Shoji, M; Li, J; D'Amico, G; Liotta, D; French, C T; Wartmann, M; Altmann, K H; Giannakakou, P

    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...... reaction to construct the C6-C7 carbon-carbon bond, and a Yamaguchi macrolactonization to complete the required skeletal framework. Biological studies with the synthesized compounds led to the identification of epothilone analogues 3, 4, 7, 8, 9, and 11 as potent tubulin polymerization promoters and......-activity relationships, including the conclusion that neither the epoxide nor the stereochemistry at C12 are essential, while the stereochemistry at both C13 and C15 are crucial for biological activity. These studies also confirmed the importance of both the cyclopropyl and 5-methylpyridine moieties in conferring potent...

  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. Sub-Coulomb fusion excitation function for 12 C + 12 C

    International Nuclear Information System (INIS)

    Fusion excitation functions are measured for the o, p and n evaporation channels in the fusion of the 12 C + 12 C system at center of mass energies between 4.5 and 6.5 MeV, with energy steps of 75 keV. The X-ray technique is used with a new absolute normalization method which is independent of charge collection and allows at the same time to monitor the Carbon buildup on the target. Good agreement is obtained with absolute cross section values previously measured using particle detection techniques, but smaller energy steps are used in the present experiment. As in previous works much structure is seen in the excitation function which is consistent with the positions of resonances reported in the literature for this system. (Author)

  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. [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

  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. Stable carbon isotope analysis of bone apatite

    International Nuclear Information System (INIS)

    The application of stable carbon isotope analysis to bone apatite is investigated. Bone apatite was prepared from 28 samples of 5 species of modern browsing herbivores, and their 13C/12C ratios measured. The δ13C values for bone apatite of the modern specimens shows a mean enrichment of +12 o/oo relative to the C3 dietary mean of -26.5o/oo. The values for T. strepsiceros (kudu) suggest that it is not a consistent browzer, as was formerly believed. Seven fossil bone apatite browzer samples gave δ13C values which fell within the range for the modern samples. It is concluded that the 13C/12C ratio in modern bone apatite accurately reflects diet, but data for fossil samples was insufficient to allow a firm conclusion about the reliability of bone apatite dietary tracing in archaeological contexts

  12. 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...

  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. 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

  15. 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...

  16. 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... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Office of Management. 905.12 Section 905.12 Banks and Banking FEDERAL HOUSING FINANCE BOARD FEDERAL HOUSING FINANCE BOARD ORGANIZATION...

  17. 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 §...

  18. Organic modification of carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

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

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

    Science.gov (United States)

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

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

    International Nuclear Information System (INIS)

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

  2. Surface plasmon observed for carbon nanotubes

    International Nuclear Information System (INIS)

    This paper presents parallel electron energy loss spectra (PEELS) results, obtained for individual carbon nanotubes, using nanoprobe techniques (1-2 nm diameter electron beam), energy resolution 0.5 eV and collection times of 4-25 sec. The aim was to use a nanoprobe to compare PEELS spectra from different parts of a tube, in order to search for variations in sp2/sp3 bonding ratios as well as to look for orientation dependent plasmon and core-loss phenomena. It also seemed interesting to compare results for nanotubes with those for other varieties of graphitized carbons. The most interesting result so far was the appearance of a 15 eV plasmon peak, which appeared only for tubes containing ≤ about 12 graphite-like layers. This peak did not shift significantly with tube size. A low-loss peaks at 6 eV of variable relative intensity was also observed this peak was relatively very weak for amorphous tubes; it appears to be characteristic of graphite-like layers, as found for nanotubes and, of course, graphite itself. This paper is restricted to discussion of the low-loss results. The experimental techniques are first described, including some details of the methods which may be used to disperse and support sooty carbons for high-resolution transmission electron microscopy. The results are then presented, followed by an interpretation of all the low-loss PEELS results, including those of the other authors. 14 refs., 2 figs

  3. Carbon nanotubes decorating methods

    Directory of Open Access Journals (Sweden)

    A.D. Dobrzańska-Danikiewicz

    2013-06-01

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

  4. 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

  5. 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.

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

    International Nuclear Information System (INIS)

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

  7. Organometallic B12-DNA conjugate

    DEFF Research Database (Denmark)

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

    2014-01-01

    humans and animals, through the endogenous B12 transport systems. Binding of the organometallic B12 octadecanucleotide to the three important human proteins of B12 transport was studied, to examine its structural suitability for the task of eventual in vivo oligonucleotide delivery. Binding was efficient......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...... with transcobalamin (TC), but not so efficient with the homologous glycoproteins intrinsic factor and haptocorrin. Binding of the B12 octadecanucleotide to TC suggests the capacity of the B12 moiety to serve as a natural vector for specific transport of single stranded, organometallic oligonucleotide...

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

    Science.gov (United States)

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

    2013-12-01

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

  9. 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

  10. The carbonization of granular polyaniline to produce nitrogen-containing carbon

    Czech Academy of Sciences Publication Activity Database

    Rozlívková, Zuzana; Trchová, Miroslava; Exnerová, Milena; Stejskal, Jaroslav

    2011-01-01

    Roč. 161, 11/12 (2011), s. 1122-1129. ISSN 0379-6779 R&D Projects: GA AV ČR IAA100500902; GA AV ČR IAA400500905; GA ČR GA203/08/0686 Institutional research plan: CEZ:AV0Z40500505 Keywords : polyaniline * conducting polymer * carbon Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.829, year: 2011

  11. Degradation of 1,2-dichlorobenzene by a Pseudomonas sp.

    OpenAIRE

    Haigler, B E; Nishino, S F; Spain, J C

    1988-01-01

    A Pseudomonas sp. that was capable of growth on 1,2-dichlorobenzene (o-DCB) or chlorobenzene as a sole source of carbon and energy was isolated by selective enrichment from activated sludge. The initial steps involved in the degradation of o-DCB were investigated by isolation of metabolites, respirometry, and assay of enzymes in cell extracts. Extracts of o-DCB-grown cells converted radiolabeled o-DCB to 3,4-dichloro-cis-1,2-dihydroxycyclohexa-3,5-diene (o-DCB dihydrodiol). 3,4-Dichlorocatech...

  12. Carbon Monoxide Toxicity: The difficulty in diagnosing this leading cause of poisoning

    OpenAIRE

    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. Th...

  13. 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...

  14. Activated carbons from African oil palm waste shells and fibre for hydrogen storage

    OpenAIRE

    Liliana Giraldo; Maria Fernanda González-Navarro; Juan Carlos Moreno-Piraján

    2013-01-01

    We prepared a series of activated carbons by chemical activation with two strong bases in-group that few use, and I with waste from shell and fibers and oil-palm African. Activated carbons are obtained with relatively high surface areas (1605 m2/g). We study the textural and chemical properties and its effect on hydrogen storage. The activated carbons obtained from fibrous wastes exhibit a high hydrogen storage capacity of 6.0 wt % at 77 K and 12 bar.

  15. Nitrogen deposition: how important is it for global terrestrial carbon uptake?

    OpenAIRE

    Bala, G.; N. Devaraju; R. K. Chaturvedi; K. Caldeira; R. Nemani

    2013-01-01

    Global carbon budget studies indicate that the terrestrial ecosystems have remained a large sink for carbon despite widespread deforestation activities. CO2 fertilization, N deposition and re-growth of mid-latitude forests are believed to be key drivers for land carbon uptake. In this study, we assess the importance of N deposition by performing idealized near-equilibrium simulations using the Community Land Model 4.0 (CLM4). In our equilibrium simulations, only 12–17% of th...

  16. Elevated Vitamin B12 Levels

    OpenAIRE

    Melike Sezgin Evim; Rahime Tüten; Birol Baytan; Selin Yakarışık; Adalet Meral Güneş

    2014-01-01

    Vitamin B12 is essential to all cells in the body. Both high levels and low levels of vitamin B12 are significant. High serum cobalamin (vitamin B12) levels are found particularly in hematological disorders, solid tumors, autoimmune diseases, renal diseases and infectious diseases; and this elevation is associated with prognosis in some of these diseases. High levels of serum vitamin B12 should be taken into consideration and more studies should be performed on this issue.

  17. Elevated Vitamin B12 Levels

    Directory of Open Access Journals (Sweden)

    Melike Sezgin Evim

    2014-12-01

    Full Text Available Vitamin B12 is essential to all cells in the body. Both high levels and low levels of vitamin B12 are significant. High serum cobalamin (vitamin B12 levels are found particularly in hematological disorders, solid tumors, autoimmune diseases, renal diseases and infectious diseases; and this elevation is associated with prognosis in some of these diseases. High levels of serum vitamin B12 should be taken into consideration and more studies should be performed on this issue.

  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. Organic/inorganic hybrid nanomaterials with vitamin B12 functions

    Directory of Open Access Journals (Sweden)

    Yoshio Hisaeda, Takahiro Masuko, Erika Hanashima and Takashi Hayashi

    2006-01-01

    Full Text Available A hybrid nanomaterial was prepared by human serum albumin (HSA and vitamin B12 derivatives. The incorporation of hydrophobic vitamin B12 derivatives, which have ester groups in place of the peripheral amide moieties of the natural cobalamin, into HSA is primarily controlled by the hydrophobicity of the peripheral ester groups. Microenvironmental property around the hydrophobic vitamin B12 in HSA was examined by fluorescence and fluorescence polarization measurements. The hydrophobic vitamin B12 itself in HSA is in a microenvironment equivalent in medium polarity to dichloromethane. The molecular motion of hydrophobic vitamin B12 in HSA was markedly suppressed under such microenvironmental conditions. Carbon-skeleton rearrangement reaction of an alkyl radical derived from an alkyl ligand bound to the hydrophobic vitamin B12 was markedly favored in HSA aqueous solution, relative to the reactions in methanol and benzene. The 1,2-migration of the electron-withdrawing group arises from both the suppression of molecular motion and desolvation effects on the alkylated hydrophobic vitamin B12 in HSA.

  20. 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...

  1. 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.

  2. 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

  3. 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...

  4. Inorganic carbon acquisition in potentially toxic and non-toxic diatoms: the effect of pH-induced changes in the seawater carbonate chemistry

    DEFF Research Database (Denmark)

    Trimborn, S; Lundholm, Nina; Thoms, S;

    2008-01-01

    The effects of pH-induced changes in seawater carbonate chemistry on inorganic carbon (C-i) acquisition and domoic acid (DA) production were studied in two potentially toxic diatom species, Pseudo-nitzschia multiseries and Nitzschia navis-varingica, and the non-toxic Stellarima stellaris. In vivo......H. In terms of carbon source, all species took up both CO2 and HCO3-. K-1/2 values for inorganic carbon uptake decreased with increasing pH in two species, while in N. navis-varingica apparent affinities did not change. While the contribution of HCO3- to net fixation was more than 85% in S. stellaris...

  5. Carbon Concentration of Austenite

    Directory of Open Access Journals (Sweden)

    Z. Ławrynowicz

    2007-07-01

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

  6. 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.

  7. Integrating carbon nanotube into activated carbon matrix for improving the performance of supercapacitor

    International Nuclear Information System (INIS)

    Highlights: ► Hydrothermal carbonization method to prepare “tube-in-activated carbon” composite. ► Due to high specific surface area, suitable pore size and low electrical resistance. ► It exhibited high capacitance value and excellent cyclibility for supercapacitor. - Abstract: A method of in situ integrating carbon nanotubes (CNTs) into activated carbon (AC) matrix was developed to improve the performance of AC as a supercapacitor electrode. Glucose solution containing pre-dispersed CNTs was hydrothermally carbonized to be a char-like intermediate product, and finally converted into a “tube-in-AC” structure by the chemical activation using KOH. The “tube-in-AC” composite had oxygen content of 12.98 wt%, specific surface area of 1626 m2/g and 90% of 1–2 nm micropores. It exhibited capacitance of 378 F/g in the aqueous KOH electrolyte and excellent cyclibility under high current, that is, the capacitance only decreased 4.6% after 2000 cycles at scanning rate of 100 mV/s. These performances of “tube-in-AC” electrode are better than those of commercial AC electrodes, post-mixed with CNTs or carbon black.

  8. 75 FR 28237 - Certain Magnesia Carbon Bricks From the People's Republic of China: Notice of Preliminary...

    Science.gov (United States)

    2010-05-20

    ... Dumping, 75 FR 20335 (April19, 2010). \\3\\ See Certain Magnesia Carbon Bricks From China and Mexico...-468 and 731-TA-116667 (Preliminary) Certain Magnesia Carbon Bricks From China, 74 FR 49889 (September... Value, 75 FR 11847 (March 12, 2010) (``Preliminary Determination''). On April 21, 2010, the...

  9. 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...

  10. 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...

  11. 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.

  12. 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)

  13. Using hybrid method to evaluate carbon footprint of Xiamen City, China

    International Nuclear Information System (INIS)

    For more holistic inventory estimation, this paper uses a hybrid approach to access the carbon footprint of Xiamen City in 2009. Besides carbon emissions from the end-use sector activities (called Scope 1+2 by WRI/WBCSD) in normal research, carbon emissions from the cross-boundary traffic and the embodied energy of key urban imported materials (namely Scope 3) were also included. The results are as follow: (1) Carbon emissions within Scope 1+2 only take up 66.14% of total carbon footprint, while emissions within Scope 3 which have usually been ignored account for 33.84%. (2) Industry is the most carbon-intensive end use sector which contributes 32.74% of the total carbon footprint and 55.13% of energy use emissions in Scope 1+2. (3) The per capita carbon footprint of Xiamen is just about one-third of that in Denver. (4) Comparing with Denver, the proportion of embodied emissions in Xiamen was 10.60% higher than Denver. Overall, Xiamen is relatively a low-carbon city with characters of industrial carbon-intensive and high embodied emissions. Further analysis indicates that the urbanization and industrialization in Xiamen might cause more material consumption and industrial emissions. These highlight the importance of management for Scope 3 emissions in the developing cities. - Highlights: • Carbon emissions from Scope 1+2+3 are calculated for Xiamen City, China. • Carbon footprint in Xiamen is industrial carbon-intensive and high embodied emissions. • Management for Scope 3 emissions in the developing cities is important

  14. The Carbon Trading Game

    International Nuclear Information System (INIS)

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

  15. 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

  16. Carbon Ion Therapy

    DEFF Research Database (Denmark)

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

    On the importance of choice of target size for selective boosting of hypoxic tumor subvolumina in carbon ion therapy Purpose: Functional imaging methods in radiotherapy are maturing and can to some extent uncover radio resistant structures found within a tumour entity. Selective boost of identified...... to the surface where the beam enters) are examined. For each plan the minimum,  maximum and the dose averaged LET of the PTV is calculated. The numbers are translated to OER using several sets of data found in literature for various cell lines. Results: We find a strong dependence of the dose average LET and OER...... effect. All cell lines investigated here did not reach an OER of 1, even for the smaller structures, which may indicate that the achievable dose average LET of carbon ions is too low, and heavier ions than carbon may be considered for functional LET-painting....

  17. Carbon Nanotubes for Supercapacitor

    Directory of Open Access Journals (Sweden)

    Li Jianyi

    2010-01-01

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

  18. A Binary Cyclic Carbonates-Based Electrolyte Containing Propylene Carbonate and Trifluoropropylene Carbonate for 5 V Lithium-Ion Batteries

    International Nuclear Information System (INIS)

    Graphical abstract: A binary cyclic carbonates-based electrolyte containing propylene carbonate and trifluoropropylene carbonate with an optimized volume ratio is successfully applied for 5 V lithium-ion batteries. Display Omitted -- Highlights: •A binary solvent electrolyte containing TFPC and PC is used for high-voltage LIBs. •Volume ratio of TFPC/PC is a crucial factor affecting the physical and electrochemical properties. •The binary solvent can maintain a stable liquid phase in a broad temperature range. •Graphite anode works well in the electrolyte of 1 mol dm−3 LiPF6-TFPC/PC (1:2). •The optimized electrolyte has good compatibility with 5 V LiNi0.5Mn1.5O4 cathode. -- Abstract: To widen the operating potential window of electrolyte used for lithium-ion batteries, a binary cyclic carbonates-based electrolyte containing propylene carbonate (PC) and trifluoropropylene carbonate (TFPC) with an optimized volume ratio has been successfully proposed. The main function of additive TFPC is to establish a stable SEI layer on graphite electrode and suppress the intercalation reaction of PC molecules. Unlike the previous works, where the TFPC/PC involved electrolyte was simply estimated at a certain volume ration and recognized as an unfavorable system, in this work, the physical properties of the electrolyte solutions with a series of volume ratios of TFPC/PC and their electrochemical performances in a graphite/Li cell and 5 V LiNi0.5Mn1.5O4/Li cell have been systematically studied. The electrolyte of 1 mol dm−3 LiPF6-TFPC/PC (1:2) is adopted as the optimized system due to its high ionic conductivity, low viscosity, broad operating potential window, wide liquid temperature range (−50 ∼ 240 °C) and suitable film-forming property. Both the graphite and LiNi0.5Mn1.5O4 electrodes were found to exhibit high reversible capacity and superb rate performance in the optimized electrolyte, making us have a new recognition of this important binary solvent

  19. 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.

  20. 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