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1

Thermal Decomposition of Lanthanide, Yttrium, and Scandium Oxalates and Carbonates  

NASA Astrophysics Data System (ADS)

Data concerning the thermal decomposition of lanthanide, yttrium, and scandium oxalates and carbonates are surveyed. The complexity of the process, the large number of stages involved, and the dependence of the composition of the intermediates in the thermal transformations on the experimental conditions is noted. Certain process characteristics have been discovered and it is concluded that the decomposition process depends on the ionic radius of the metal. The bibliography includes 83 references.

Sharov, Vyacheslav A.; Bezdenezhnykh, G. V.

1981-07-01

2

Yttrium silicate oxidation protective coating for SiC coated carbon\\/carbon composites  

Microsoft Academic Search

Four kinds of yttrium silicate oxidation protective coatings SiO2·Y2O3, 1.5SiO2·Y2O3, 1.5SiO2·Y2O3\\/SiO2·Y2O3 and 2SiO2·Y2O3\\/1.5SiO2·Y2O3\\/SiO2·Y2O3 were prepared by plasma spray on the surface of SiC pre-coated carbon\\/carbon composites. The structures of the coatings were characterized by XRD, SEM and EDS analyses. It was shown that the gradied 2SiO2·Y2O3\\/1.5SiO2·Y2O3\\/SiO2·Y2O3 multi-layer coating had better high-temperature oxidation resistance. It could protect carbon\\/carbon composites from oxidation

Jian-Feng Huang; He-Jun Li; Xie-Rong Zeng; Ke-Zhi Li

2006-01-01

3

Selective encapsulation of the carbides of yttrium and titanium into carbon nanoclusters  

NASA Astrophysics Data System (ADS)

Characterization of the arc-discharge deposits at the cathode from anodes containing yttrium oxide and titanium by transmission electron microscopy and x-ray diffraction shows different results with respect to an encapsulation of the metal carbides into carbon clusters. Yttrium carbide is encapsulated into carbon nanoclusters in a crystalline phase. The formation of titanium carbide, on the other hand, preempts the formation of the carbon—carbon bonds necessary to form the carbon cages, so that only titanium carbide clusters are observed. Thermodynamic data support the interpretation of the results.

Seraphin, Supapan; Zhou, Dan; Jiao, Jun; Withers, James C.; Loutfy, Raouf

1993-10-01

4

RBS and GAXRD contributions to yttrium implanted extra low carbon steel characterization  

SciTech Connect

Extra low carbon steel samples were yttrium implanted using an ion implantation method. Composition and structural studies were carried out before and after yttrium implantations by several analytical and structural techniques (Rutherford backscattering spectrometry, reflection high energy electron diffraction, scanning electron microscopy, X-ray diffraction, and glancing angle X-ray diffraction) to characterize the yttrium implantation effect on extra low carbon steel. The aim of this article is to show the contributions of Rutherford back-scattering spectrometry (RBS) and glancing angle X-ray diffraction (GAXRD) to the determination of yttrium depth profiles in the samples. The results obtained by these techniques are compared to those of the other analyses performed in this work to show the existing correlation between composition and structural studies. Their results allow a better understanding of the effect of yttrium implantation in extra low carbon steel before studying their corrosion resistance at high temperature.

Caudron, E.; Buscail, H. [Equipe Locale Univ. Blaise Pascal Clermont-Fd II, Le Puy en Velay (France). Lab. Vellave d`Elaboration et d`Etude des Materiaux] [Equipe Locale Univ. Blaise Pascal Clermont-Fd II, Le Puy en Velay (France). Lab. Vellave d`Elaboration et d`Etude des Materiaux; Jacob, Y.P.; Stroosnijder, M.F. [European Commission, Ispra (Italy). Inst. for Advanced Materials] [European Commission, Ispra (Italy). Inst. for Advanced Materials

1999-02-01

5

Preparation of yttrium, lanthanum, cerium, and neodymium basic carbonate particles by homogeneous precipitation  

SciTech Connect

Uniform yttrium, lanthanum, cerium, and neodymium basic carbonate particles were prepared by homogeneous precipitation. Powders were characterized with respect to size, shape, crystal structure, and thermal decomposition behavior. Yttria precursor particles were spherical, monosized (0.4 {mu}m), and amorphous; whereas lanthana, neodymia, and ceria precursors were prismatic (ranging from 1 to 6 {mu}m in size) and crystalline. Crystal structure was found to be ancylite-type orthorhombic symmetry in all three cases. Upon heating in air, yttrium, lanthanum, and neodymium precursors underwent two-step decomposition to first form oxycarbonate and then oxide. Cerium hydroxycarbonate decomposed in a single step to form the oxide.

Akinc, M.; Sordelet, D. (Iowa State Univ., Ames (USA))

1987-07-01

6

PET Imaging of Soluble Yttrium-86-Labeled Carbon Nanotubes in Mice  

PubMed Central

Background The potential medical applications of nanomaterials are shaping the landscape of the nanobiotechnology field and driving it forward. A key factor in determining the suitability of these nanomaterials must be how they interface with biological systems. Single walled carbon nanotubes (CNT) are being investigated as platforms for the delivery of biological, radiological, and chemical payloads to target tissues. CNT are mechanically robust graphene cylinders comprised of sp2-bonded carbon atoms and possessing highly regular structures with defined periodicity. CNT exhibit unique mechanochemical properties that can be exploited for the development of novel drug delivery platforms. In order to evaluate the potential usefulness of this CNT scaffold, we undertook an imaging study to determine the tissue biodistribution and pharmacokinetics of prototypical DOTA-functionalized CNT labeled with yttrium-86 and indium-111 (86Y-CNT and 111In-CNT, respectively) in a mouse model. Methodology and Principal Findings The 86Y-CNT construct was synthesized from amine-functionalized, water-soluble CNT by covalently attaching multiple copies of DOTA chelates and then radiolabeling with the positron-emitting metal-ion, yttrium-86. A gamma-emitting 111In-CNT construct was similarly prepared and purified. The constructs were characterized spectroscopically, microscopically, and chromatographically. The whole-body distribution and clearance of yttrium-86 was characterized at 3 and 24 hours post-injection using positron emission tomography (PET). The yttrium-86 cleared the blood within 3 hours and distributed predominantly to the kidneys, liver, spleen and bone. Although the activity that accumulated in the kidney cleared with time, the whole-body clearance was slow. Differential uptake in these target tissues was observed following intraveneous or intraperitoneal injection. Conclusions The whole-body PET images indicated that the major sites of accumulation of activity resulting from the administration of 86Y-CNT were the kidney, liver, spleen, and to a much less extent the bone. Blood clearance was rapid and could be beneficial in the use of short-lived radionuclides in diagnostic applications. PMID:17878942

Jaggi, Jaspreet S.; Finn, Ronald D.; Zanzonico, Pat B.; Villa, Carlos; Rey, Diego; Mendenhall, Juana; Batt, Carl A.; Njardarson, Jon T.; Scheinberg, David A.

2007-01-01

7

In situ high-temperature X-ray diffraction characterization of yttrium-implanted extra low-carbon steel  

SciTech Connect

Yttrium-implanted and unimplanted extra low-carbon steel samples were analyzed at T = 700 C and under an oxygen partial pressure P{sub O2} = 0.041Pa for 24 h to show the yttrium implantation effect on extra low-carbon steel high-temperature corrosion resistance. Sample oxidation weight gains were studied by thermogravimetry, and structural analyses were performed using in situ high-temperature X-ray diffraction with the same experimental conditions. The aim of this paper is to show the initial nucleation stage of the main compounds induced by oxidation at high temperatures according to the initial sample treatment (yttrium-implanted or unimplanted). The results obtained by in situ high-temperature X-ray diffraction will be compared to those by thermogravimetry to show the existing correlation between weight gain curves and structural studies. Results allow one to understand the improved corrosion resistance of yttrium-implanted extra low-carbon steel at high temperatures.

Caudron, E.; Buscail, H.; Perrier, S.

1999-11-01

8

Effect of yttrium and chromium ion implantation on crevice electrochemical behavior of carbon steel in sodium chloride solution  

NASA Astrophysics Data System (ADS)

In order to study the effect of yttrium (Y) and chromium (Cr) ion implantation on the crevice corrosion behavior of carbon steel, the carbon steel was implanted with Y and Cr ion using MEVVA source at an energy of 40 keV. Electrochemical measurement was employed to evaluate the crevice corrosion of implanted carbon steel in NaCl solution. The results indicated that, after Y and Cr ion implantation, the carbon steel's crevice corrosion resistance and electrochemical characteristic were significantly improved in NaCl solution when the implantation dose of Y increased. Auger electron spectroscopy (AES) analysis of the implanted carbon steel manifested that the surface layer was mainly composed of elements Fe, Cr, O, and Y. Most of element Y was located near the outside region of the surface layer/solution interface, whereas Cr was enriched in the transition area between surface layer and matrix. By X-ray photoelectron spectroscopy (XPS) analysis, the implanted Y was in the form of Y 2O 3, whereas Cr in the form of Cr 2O 3 in the surface layer. The mechanism of the crevice corrosion resistance and electrochemical characteristic improvement was that, after Y and Cr ion implantation, the surface layer seemed to be constituted by Y 2O 3 and Cr 2O 3. The surface layer acted as a barrier to reduce the metal matrix to contact with the corrosion medium such as inhibiting Cl - ions from corroding the layer.

Liang, Chenghao; Huang, Naibao

2008-12-01

9

Correlation of optical properties and temperature-induced irreversible phase transitions in europium-doped yttrium carbonate nanoparticles  

SciTech Connect

Nanophase europium-doped yttrium carbonate precursors are subjected to heat treatments, ranging from 300 Degree-Sign C to 1100 Degree-Sign C for dwell times of 5 min, 30 min, and 180 min. XRD, TEM, FT-IR, fluorescence, fluorescence excitation, and fluorescence lifetime measurements are used to characterize the materials. Upon heating, the material transitions through several amorphous stages until it reaches the crystalline cubic Y{sub 2}O{sub 3} phase. DSC measurements show an exothermic transition at 665.7 Degree-Sign C, indicating the formation of crystalline Y{sub 2}O{sub 3}. The grain size development is fitted by the relaxation equation and yields an activation energy of 50.3 kJ/mol. The amorphous phases are characterized by inhomogenously broadened optical spectra. Heating up to 700 Degree-Sign C leads to an increased fluorescence lifetime (from about 1 ms to 2.4 ms). As the material is heated to higher temperatures and completes the formation of the crystalline cubic Y{sub 2}O{sub 3} phase, the optical spectra become narrower and the fluorescence lifetime decreases to about 1.2 ms. - Graphical abstract: Fluorescence lifetimes of Eu-doped Y{sub 2}O{sub 3} precursors heated for 5, 30, and 180 min to various temperatures. Highlights: Black-Right-Pointing-Pointer Irreversible phase transitions in nanoparticles are of interest for thermometry. Black-Right-Pointing-Pointer Eu-doped nanophase yttrium carbonate precursors were heat-treated. Black-Right-Pointing-Pointer The material undergoes decomposition and crystallization. Black-Right-Pointing-Pointer Morphological and optical properties are measured. Black-Right-Pointing-Pointer Optical properties can be used to deduce the temperature.

Gunawidjaja, Ray; Myint, Thandar [Applied Sciences Laboratory, Institute for Shock Physics, Washington State University, Spokane, WA 99210-1495 (United States); Eilers, Hergen, E-mail: eilers@wsu.edu [Applied Sciences Laboratory, Institute for Shock Physics, Washington State University, Spokane, WA 99210-1495 (United States)

2011-12-15

10

Synergistic effects of sequential carbon dioxide and neodymium:yttrium aluminum garnet laser injuries. Experimental observations and measurements  

SciTech Connect

The carbon dioxide and neodymium:yttrium aluminum garnet lasers have well documented but characteristically different biological effects, yet little is known about their cumulative, synergistic, or paradoxical effects when used sequentially on living tissue. Using a Merrimack ML 880 laser, a series of superimposed CO/sub 2/ and Nd:YAG lesions in various combinations were produced on the undersurface of dog tongues. Therapeutic time and power settings were chosen and the number of applications varied, with suitable controls. Observations and measurements were made on acute, healing, and healed lesions. All lesions were excised and submitted for routine hematoxylin and eosin histology. Acute lesions were also assessed for cell viability using rhodamine 123 as a supravital marker. The results show that, even though all the lesions eventually heal, the actual cell damage produced by the Nd:YAG laser is much more than is suggested by the size of the acute lesion. This cell damage can be reduced by the surface carbonization produced by initial application of the CO/sub 2/ laser. Higher surface temperatures are reached in this combination with less fibrosis and scarring than equal energy counterparts where the Nd:YAG laser was applied first. The knowledge of these synergistic effects can be used to advantage in the clinical setting. The rhodamine 123 technique also appears to be a valid measure of acute thermal tissue injury.

Primrose, W.J.; McDonald, G.A.; O'Brien, M.J.; Vaughan, C.W.; Strong, M.S.

1987-01-01

11

Evaluation of carbon deposition behavior on the nickel/yttrium-stabilized zirconia anode-supported fuel cell fueled with simulated syngas  

NASA Astrophysics Data System (ADS)

The nickel/yttrium-stabilized zirconia (Ni/YSZ) anode-supported solid oxide fuel cells (SOFCs) have been operated under various simulated syngases at different temperatures to investigate the degradation behavior of the cells caused by carbon deposition. The results show that the carbon morphology and the cell performance degradation are influenced significantly by the operation temperature. The stability of the cell fueled with syngas can be improved by applying a constant current, but the cell degraded quickly after carbon deposition. The microstructure damage is close to the anode surface and leads to a conductivity decrease, which is an important reason for the cell degradation and failure at 750 °C. Conversely, the degradation behavior at 650 °C is mainly due to solid carbon deposits inside of the anode that impede fuel diffusion and electrochemical reactions on the anodic side. The effect of carbon deposition on the microstructure degradation is also investigated using transmission electron microscope.

Chen, Tao; Wang, Wei Guo; Miao, He; Li, Tingshuai; Xu, Cheng

2011-03-01

12

CARBON-CARBON COMPOSITE ALLCOMP Carbon-Carbon Composite  

E-print Network

CARBON-CARBON COMPOSITE ALLCOMP Carbon-Carbon Composite · C-C supplied in two forms · T300: C strength 4340 steel, carbon-carbon composite, and Carbon-Silicon Carbide composite were tested to examine materials. MATERIALS AND DESIRED DATA Carbon-Carbon Composites(T300 & SWB): Crush Resistance, Bend Strength

Rollins, Andrew M.

13

Multilayer coating with self-sealing properties for carbon–carbon composites  

Microsoft Academic Search

This work proposes a simple and low cost method to deposit an effective multilayer protective coating on carbon–carbon composites (C\\/C). The first layer is made of molybdenum disilicide particles in a barium boron aluminosilicate glass (SABB); the second (external) layer is made of yttrium oxide modified SABB. A study of the reactions between the yttrium oxide and the SABB glass

Federico Smeacetto; Monica Ferraris; Milena Salvo

2003-01-01

14

Carbon Cycles  

NSDL National Science Digital Library

Students are introduced to the concept of energy cycles by learning about the carbon cycle. They learn how carbon atoms travel through the geological (ancient) carbon cycle and the biological/physical carbon cycle. They consider how human activities disturb the carbon cycle by emitting carbon dioxide into the atmosphere. They discuss how engineers and scientists are working to reduce carbon dioxide emissions. Lastly, students consider how they can help the world through simple energy conservation measures.

Integrated Teaching And Learning Program

15

carbon cycle  

NSDL National Science Digital Library

Life on earth is based on carbon. Living things acquire carbon from their environment - from air, water, soil, and rock and from other living things - through processes such as photosynthesis, respiration and decomposition. The carbon cycle model is a representation of the movement of carbon from sources to sinks through chemical and physical transfers. The carbon cycle activity allows students to see the effect of fossil fuel burning on the carbon cycle.

School, Maryland V.

16

Carbon-carbon cylinder block  

NASA Technical Reports Server (NTRS)

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.

Ransone, Philip O. (Inventor)

1998-01-01

17

Carbon-Carbon Radiator  

NASA Technical Reports Server (NTRS)

Carbon-Carbon (C-C) Radiator was a success and proved that the technology can work to reduce Spacecraft weight. C-C has a niche, especially for high temperatures. C-C still needs further development: reduction in fabrication time and cost - high conductivity "traditional" composites are more competitive, and CTE interface issues with heat pipes. Redundancy a good idea - we flew the spare panel. CSRP was a success -informal inter-agency partnership. Possible follow-on: C-C foam for low CTE mirrors/optical benches.

Butler, Dan; Powers, Edward I. (Technical Monitor)

2001-01-01

18

Carbon Smackdown: Carbon Capture  

ScienceCinema

In this July 9, 2010 Berkeley Lab summer lecture, Lab scientists Jeff Long of the Materials Sciences and Nancy Brown of the Environmental Energy Technologies Division discuss their efforts to fight climate change by capturing carbon from the flue gas of power plants, as well as directly from the air

Jeffrey Long

2010-09-01

19

Carbon Configurations  

NSDL National Science Digital Library

In this activity, learners use geometry to predict the shape of carbon. Learners twist and attach chenille stem pieces that represent bonds between different carbon atoms. Information about tetrahedral, trigonal planar, and diamond geometry types is included in this resource. This activity can also be used to introduce learners to allotropes (pure carbon forms) and fullerenes such as buckyballs and carbon nanotubes.

Yu, Julie

2010-01-01

20

Calcium Carbonate  

MedlinePLUS

... heart. Calcium carbonate also is used as an antacid to relieve heartburn, acid indigestion, and upset stomach. ... use.Do not take calcium carbonate as an antacid for more than 2 weeks unless your doctor ...

21

Carbon Footprint  

NSDL National Science Digital Library

This website has interactive tools to calculate your carbon footprint, which is a way to measure how much carbon dioxide and other greenhouse gases are produced by your activities. This site also contains specific recommendations for reducing and off-setting your carbon footprint, as well as links to news and information about global warming.

Ltd, Carbon F.

22

Carbon Sequestration  

NSDL National Science Digital Library

In this inquiry-based lesson, learners measure the biomass of trees, calculate the carbon stored by the trees, and use this information to create recommendations about using trees for carbon sequestration. This activity encourages learners to think critically about managing forests for carbon sequestration.

Science, New Y.

2012-01-01

23

Carbon-Carbon Piston Architectures  

NASA Technical Reports Server (NTRS)

An improved structure for carbon-carbon composite piston architectures consists of replacing the knitted fiber, three-dimensional piston preform architecture described in U.S. Pat. No. 4.909,133 (Taylor et al.) with a two-dimensional lay-up or molding of carbon fiber fabric or tape. Initially. the carbon fabric or tape layers are prepregged with carbonaceous organic resins and/or pitches and are laid up or molded about a mandrel. to form a carbon-fiber reinforced organic-matrix composite part shaped like a "U" channel, a "T"-bar. or a combination of the two. The molded carbon-fiber reinforced organic-matrix composite part is then pyrolized in an inert atmosphere, to convert the organic matrix materials to carbon. At this point, cylindrical piston blanks are cored from the "U" channel, "T"-bar, or combination part. These blanks are then densified by reimpregnation with resins or pitches which are subsequently carbonized. Densification is also be accomplished by direct infiltration with carbon by vapor deposition processes. Once the desired density has been achieved, the piston billets are machined to final piston dimensions; coated with oxidation sealants; and/or coated with a catalyst. When compared to conventional steel or aluminum-alloy pistons, the use of carbon-carbon composite pistons reduces the overall weight of the engine; allows for operation at higher temperatures without a loss of strength; allows for quieter operation; reduces the heat loss; and reduces the level of hydrocarbon emissions.

Rivers, H. Kevin (Inventor); Ransone, Philip O. (Inventor); Northam, G. Burton (Inventor); Schwind, Francis A. (Inventor)

1999-01-01

24

Carbonate aquifers  

USGS Publications Warehouse

Only limited hydrogeological research has been conducted using ichnology in carbonate aquifer characterization. Regardless, important applications of ichnology to carbonate aquifer characterization include its use to distinguish and delineate depositional cycles, correlate mappable biogenically altered surfaces, identify zones of preferential groundwater flow and paleogroundwater flow, and better understand the origin of ichnofabric-related karst features. Three case studies, which include Pleistocene carbonate rocks of the Biscayne aquifer in southern Florida and Cretaceous carbonate strata of the Edwards–Trinity aquifer system in central Texas, demonstrate that (1) there can be a strong relation between ichnofabrics and groundwater flow in carbonate aquifers and (2) ichnology can offer a useful methodology for carbonate aquifer characterization. In these examples, zones of extremely permeable, ichnofabric-related macroporosity are mappable stratiform geobodies and as such can be represented in groundwater flow and transport simulations.

Cunningham, Kevin J.; Sukop, Michael; Curran, H. Allen

2012-01-01

25

Carbon Nanotubes.  

E-print Network

?? Carbon nanotubes have extraordinary mechanical, electrical, thermal andoptical properties. They are harder than diamond yet exible, have betterelectrical conductor than copper, but can also… (more)

Fredriksson, Tore

2014-01-01

26

CARBON MONOXIDE  

EPA Science Inventory

This document summarizes the carbon monoxide literature related to effects on man and his environment for the consideration of the Environmental Protection Agency in updating the information in the Air Quality Criteria for Carbon Monoxide. It emphasizes recent major advances in o...

27

Carbon-Carbon Piston Architectures  

NASA Technical Reports Server (NTRS)

An improved structure for carbon-carbon composite piston architectures is disclosed. The improvement consists of replacing the knitted fiber, three-dimensional piston preform architecture described in U.S. Pat.No. 4,909,133 (Taylor et al.) with a two-dimensional lay-up or molding of carbon fiber fabric or tape. Initially, the carbon fabric of tape layers are prepregged with carbonaceous organic resins and/or pitches and are laid up or molded about a mandrel, to form a carbon-fiber reinforced organic-matrix composite part shaped like a "U" channel, a "T"-bar, or a combination of the two. The molded carbon-fiber reinforced organic-matrix composite part is then pyrolized in an inert atmosphere, to convert the organic matrix materials to carbon. At this point, cylindrical piston blanks are cored from the "U"-channel, "T"-bar, or combination part. These blanks are then densified by reimpregnation with resins or pitches which are subsequently carbonized. Densification is also accomplished by direct infiltration with carbon by vapor deposition processes. Once the desired density has been achieved, the piston billets are machined to final piston dimensions; coated with oxidation sealants; and/or coated with a catalyst. When compared to conventional steel or aluminum alloy pistons, the use of carbon-carbon composite pistons reduces the overall weight of the engine; allows for operation at higher temperatures without a loss of strength; allows for quieter operation; reduces the heat loss; and reduces the level of hydrocarbon emissions.

Rivers, H. Kevin (Inventor); Ransone, Philip O. (Inventor); Northam, G. Burton (Inventor); Schwind, Francis A. (Inventor)

2000-01-01

28

Carbon Cycle  

NSDL National Science Digital Library

This activity from NOAA Earth System Research Laboratory introduces students to the current scientific understanding of the greenhouse effect and the carbon cycle. The activity leads them through several interactive tasks investigating recent trends in atmospheric carbon dioxide. Students analyze scientific data and use scientific reasoning to determine the causes responsible for these recent trends. By studying carbon cycle science in a visual and interactive manner, the activity provides students with a conceptual framework with which to address the challenges of a changing climate.

Laboratory, Noaa/earth S.

29

Carbon Cycle  

NSDL National Science Digital Library

This interactive animation focuses on the carbon cycle and includes embedded videos and captioned images to provide greater clarification and detail of the cycle than would be available by a single static visual alone.

Sciencelearn; Waikato, University O.

30

Developments in carbon materials  

NASA Technical Reports Server (NTRS)

The following carbon-based materials are reviewed and their applications discussed: fullerenes; graphite (synthetic and manufactured); activated carbon fibers; and carbon-carbon composites. Carbon R&D activities at ORNL are emphasized.

Burchell, Timothy D.

1994-01-01

31

Infiltrated carbon foam composites  

NASA Technical Reports Server (NTRS)

An infiltrated carbon foam composite and method for making the composite is described. The infiltrated carbon foam composite may include a carbonized carbon aerogel in cells of a carbon foam body and a resin is infiltrated into the carbon foam body filling the cells of the carbon foam body and spaces around the carbonized carbon aerogel. The infiltrated carbon foam composites may be useful for mid-density ablative thermal protection systems.

Lucas, Rick D. (Inventor); Danford, Harry E. (Inventor); Plucinski, Janusz W. (Inventor); Merriman, Douglas J. (Inventor); Blacker, Jesse M. (Inventor)

2012-01-01

32

Carbon–Carbon Composite Materials  

Microsoft Academic Search

Data are summarized on the performance characteristics and properties of Russian-produced and foreign carbon–carbon composite materials for various engineering applications. The effect of neutron irradiation on their macroscopic properties and structure is examined. The relationships between the radiation-induced dimensional changes and properties of the composites are established, which can be used in assessing the engineering performance and optimizing the fabrication

Yu. S. Virgil'ev; I. P. Kalyagina

2004-01-01

33

Carbon particles  

DOEpatents

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.

Hunt, Arlon J. (Oakland, CA)

1984-01-01

34

Manual of carbonate sedimentology  

SciTech Connect

This manual, organised along encycolopaedic/lexicographic lines, summarizes information on the properties and characteristics of carbonates and their environments. Part 1 deals with the elements of carbonates; Part 2 with environments, settings, and carbonate bodies; Part 3 with carbonate diagenesis, and Part 4 with carbonate reservoirs. Contents include: Elements of carbonates; Carbonate Environments, Settings and Bodies; Carbonate diagenesis; Carbonate reservoirs; Alphabetical Indices; English, Dutch, German, Spanish, French Computer Compatible Codes; Commonly Used (Informal) abbreviations.

Reijers, T.J.; Hsu, K.S.

1986-01-01

35

Carbon Temperature Model  

NSDL National Science Digital Library

With this carbon/temperature interactive model, students investigate the role of atmospheric carbon in the greenhouse effect using a relationship between atmospheric carbon dioxide and global temperature.

Center, Nasa: C.; Nasa

36

Carbon Footprint  

NSDL National Science Digital Library

Students investigate how much greenhouse gas (carbon dioxide and methane) their family releases into the atmosphere each year and relate it to climate change. To address this, students use the Environmental Protection Agency Personal Emissions Calculator to estimate their family's greenhouse gas emissions and to think about how their family could reduce those emissions.

2007-01-01

37

Carbon dioxide  

NSDL National Science Digital Library

Bubbles are an indicator of a chemical reaction. An indicator is an object, material, or organism that tells you if a specific substance is present. In the sugar test, carbon dioxide gas release is an indicator that yeast is using sugar to grow. The more gas produced, the more sugar a specific substance contains.

Arie Melamed-Katz (None;)

2007-06-19

38

Black Carbon  

NSDL National Science Digital Library

Black carbon, composed of tiny particles of soot, is produced whenever organic substances like fossil fuels, firewood or coal is incompletely burned. These particles are polluting the air and causing serious health and environmental concerns for people around the world. "Changing Planet" is produced in partnership with the National Science Foundation.

Learn, Nbc

2010-10-07

39

Carbon-carbon - An overview  

NASA Technical Reports Server (NTRS)

In nonoxidizing high-temperature environments, carbon-carbon composites retain room temperature properties to more than 2225 C; in oxidizing environments, the variety of coatings thus far developed limits maximum operating temperatures to about 1600 C. The high thermal conductivity and low thermal expansion of these composites renders them ideal for applications encountering thermal shocks. In addition, the variety of fibers, weave patterns, and layup procedures that can be used for the composites allows mechanical properties to be carefully tailored over a wide range to fit the application in question.

Buckley, John D.

1988-01-01

40

Multilayer coating for carbon-carbon composites  

Microsoft Academic Search

Because of the excellent mechanical properties at elevated temperature, carbon-fiber reinforced carbon (carbon-carbon) composites have received much attention for high-temperature structural applications. One serious drawback against actual use of carbon-carbon composites is their poor oxidation resistance in high-temperature oxidizing atmospheres. In many attempts to develop an effective oxidation-protection coating, silicon carbide coating has shown the best performance for short periods

T. Morimoto; Y. Ogura; M. Kondo; T. Ueda

1995-01-01

41

Diamond formation on carbon\\/carbon composite  

Microsoft Academic Search

A carbon\\/carbon composite was used as substrate for low-pressure diamond deposition. To enhanced diamond nucleation on carbon\\/carbon composites, a total of ten surface preparation methods have been investigated. These methods involved the use of atomic hydrogen etching, mechanical polishing, sonication, or coating. Diamond nucleation was found to occur on either the defects of the carbon\\/carbon composite substrates or diamond particulate

Jyh-Ming Ting

1995-01-01

42

Carbon City  

NSDL National Science Digital Library

Since the Industrial Revolution, atmospheric carbon dioxide concentration has risen from ~280ppm (parts per million by volume) to ~390ppm in 2010. The rate of increase for the last decade (2001-2010) has been 2.04ppm/yr, more than double the rate for the 1960's. Most scientists agree that human actions are the primary cause of the increase, the rise in Earth's average temperature since the mid-1900's and recent climate change. In this problem-based learning activity, learners develop a carbon mitigation strategy to address climate change issues. This module was developed to be used in the Earth System Science Education Alliance (ESSEA) courses for middle and high school teachers and is also available to teachers to adapt for general classroom use.

43

Carbon Cycle  

NSDL National Science Digital Library

Elementary students often successfully memorize and repeat back the stages in cycles, with no deep conceptual understanding of the complexities of the processes involved. Their ability to synthesize knowledge of the cycles with a wider breadth of information related to real-world, unresolved environmental issues such as global warming, greenhouse gas emissions or the burning of biomass for fuel is probably less well developed. In order to engage in meaningful discussions of carbon-related environmental issues, students also need an understanding of the changing nature of the earth s atmosphere. The relative proportion of nitrogen, carbon dioxide, oxygen, ozone and other gases is neither consistent around the world nor constant over time. What factors contribute to the variability in atmospheric content? Which of the factors should be controlled? What are the possible approaches to controlling them? What are the possible and probable outcomes of such controlling measures?

Lefever, Mary

2007-01-01

44

Molecular Structure of Carbonate ion  

NSDL National Science Digital Library

Carbonates were studied extensively by geologists. Common carbonate-containing geologic materials are barium calcium carbonate, lead carbonate, and strontium carbonate. Carbonate is the salt of carbonic acid. Many counter ions are possible, including calcium carbonate and barium carbonate. Calcium carbonate is a brittle white rock, used in many buildings. Lithium carbonate is used to treat manic phases for bipolar disorder/manic depression. Carbonic acid is found in carbonated beverages, giving them a tart flavor.

2002-09-18

45

Engine makers tap carbon-carbon pistons  

SciTech Connect

This article describes the use of a carbon-carbon composite, developed for nose cones and rocket nozzles, for pistons in modern internal combustion engines. The topics of the article include the carbon-carbon composite mechanical and physical characteristics, initial research, manufacturing methods, fabrication techniques, initial testing in 2 stroke and 4 stroke engines, and current research.

Ashley, S.

1994-05-01

46

Method of making carbon-carbon composites  

Microsoft Academic Search

A process for making 2D and 3D carbon-carbon composites having a combined high crystallinity, high strength, high modulus and high thermal and electrical conductivity. High-modulus\\/high-strength mesophase derived carbon fibers are woven into a suitable cloth. Layers of this easily graphitizible woven cloth are infiltrated with carbon material to form green composites. The carbonized composite is then impregnated several times with

Engle; Glen B

1993-01-01

47

Carbon Nanotubes  

NSDL National Science Digital Library

From the NanoEd Resource Portal, this course describes the purpose and uses of carbon nanotubes in etching, indentation, compression, bending, and twisting as well as their application as gears. Instructed by Dr. Meyya Meyyappan and contributed by the NASA Ames Research Center, the main content of this course is the variety of demonstration videos on each topic so visitors may make the nanoscale visible. In total, there are thirty mpg format videos, and each would make an excellent addition to any nanotechnology classroom.

Meyyappan, Meyya

2012-04-12

48

Carbon "Kidprints"  

NSDL National Science Digital Library

In this self-paced tutorial, learners explore the personal choices students make every day as resource consumers, and how those decisions contribute to the climate health of our planet. Multimedia educational resources such as video clips, digital interactive explorations and a quiz are included. This is the fifth of ten self-paced professional development modules providing opportunities for teachers to learn about climate change through first-hand data exploration. A carbon consumption calculator designed for kids to be used in the classroom and glossary links to vocabulary are included.

49

Carbon Cycle: Where Is This Crucial Carbon?  

NSDL National Science Digital Library

This demonstration aims to teach students about the nature of carbon, the different types of compounds it exists in (e.g. charcoal, glucose, carbon dioxide), the biochemical reactions it takes part in (photosynthesis and respiration), the range of processes that carbon and carbon compounds are involved in on Earth, and how these link together to form the carbon cycle. Students will be reminded that carbon is the fundamental building block of life (the element that life is based on). They will discover that carbon is contained in everything from fossil fuels to DNA and is cycled and re-cycled through the carbon cycle. Students will also understand that both animals and plants need carbon although they obtain it in different ways. This site has teacher notes and directions, suggested questions with answers, a list of required materials, and a glossary.

50

Carbon Based Resistive Memory  

Microsoft Academic Search

We propose carbon as new resistive memory material for non-volatile memories and compare three allotropes of carbon, namely carbon nanotubes, graphene-like conductive carbon and insulating carbon for their possible application as resistance-change material in high density non-volatile memories. Repetitive high-speed switching and the potential for multi-level programming have been successfully demonstrated.

Franz Kreupl; Rainer Bruchhaus; Petra Majewski; Jan B. Philipp; Ralf Symanczyk; Thomas Happ; Christian Arndt; Mirko Vogt; Roy Zimmermann; Axel Buerke; Andrew P. Graham; Michael Kund

2009-01-01

51

The Carbon Cycle  

NSDL National Science Digital Library

This narrated slide presentation shows the carbon cycle, looking at various parts of this biogeochemical sequence by examining carbon reservoirs and how carbon is exchanged among them and the atmosphere.

Thinkport; Television, Maryland P.

52

Photophysics of carbon nanotubes  

E-print Network

This thesis reviews the recent advances made in optical studies of single-wall carbon nanotubes. Studying the electronic and vibrational properties of carbon nanotubes, we find that carbon nanotubes less than 1 nm in ...

Samsonidze, Georgii G

2007-01-01

53

CALIFORNIA CARBON SEQUESTRATION THROUGH  

E-print Network

CALIFORNIA ENERGY COMMISSION CARBON SEQUESTRATION THROUGH CHANGES IN LAND USE IN WASHINGTON. Carbon Sequestration Through Changes in Land Use in Washington: Costs and Opportunities. California for Terrestrial Carbon Sequestration in Oregon. Report to Winrock International. #12;ii #12;iii Preface

54

Method of making carbon-carbon composites  

DOEpatents

A process for making 2D and 3D carbon-carbon composites having a combined high crystallinity, high strength, high modulus and high thermal and electrical conductivity. High-modulus/high-strength mesophase derived carbon fibers are woven into a suitable cloth. Layers of this easily graphitizible woven cloth are infiltrated with carbon material to form green composites. The carbonized composite is then impregnated several times with pitch by covering the composite with hot pitch under pressure. The composites are given a heat treatment between each impregnant step to crack up the infiltrated carbon and allow additional pitch to enter the microstructure during the next impregnation cycle. The impregnated composites are then given a final heat treatment in the range 2500.degree. to 3100.degree. C. to fully graphitize the fibers and the matrix carbon. The composites are then infiltrated with pyrolytic carbon by chemical vapor deposition in the range 1000.degree. C. to 1300.degree. C. at a reduced. pressure.

Engle, Glen B. (16716 Martincoit Rd., Poway, CA 92064)

1993-01-01

55

Carbon nanotube cathode with capping carbon nanosheet  

NASA Astrophysics Data System (ADS)

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 ?/? to 300 ?/? 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.

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

2013-10-01

56

Carbon Capture (Carbon Cycle 2.0)  

ScienceCinema

Berend Smit speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 3, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

Smit, Berend

2011-06-08

57

From carbon nanotubes to carbon atomic chains  

Microsoft Academic Search

Carbyne is a linear allotrope of carbon. It is formed by a linear arrangement of carbon atoms with sp-hybridization. We present a reliable and reproducible experiment to obtain these carbon atomic chains using few-layer-graphene (FLG) sheets and a HRTEM. First the FLG sheets were synthesized from worm-like exfoliated graphite and then drop-casted on a lacey-carbon copper grid. Once in the

Gilberto Casillas García; Weijia Zhang; Miguel José-Yacamán

2010-01-01

58

Carbon Capture (Carbon Cycle 2.0)  

SciTech Connect

Berend Smit speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 3, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

Smit, Berend

2010-02-03

59

Integral Ring Carbon-Carbon Piston  

NASA Technical Reports Server (NTRS)

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.

Northam, G. Burton (Inventor)

1999-01-01

60

Radiation damage in carbon-carbon composites  

Microsoft Academic Search

Graphite and carbon-carbon composite materials are widely used in plasma facing applications in current Tokamak devices such as TFTR and DIIID in the USA, JET, Tore Supra and TEXTOR in Europe, and JT-60U in Japan. Carbon-carbon composites are attractive choices for Tokamak limiters and diverters because of their low atomic number, high thermal shock resistance, high melting point, and high

T. D. Burchell; W. P. Eartherly; G. E. Nelson

1992-01-01

61

Toward Zero Carbon Energy Production Toward Zero Carbon Energy Production  

E-print Network

#12;Toward Zero Carbon Energy Production Toward Zero Carbon Energy Production Toward Zero Carbon Energy Production Toward Zero Carbon Energy Production Toward Zero Carbon Energy Production Toward Zero Carbon Energy Production Toward Zero Carbon Energy Production Toward Zero Carbon Energy Production Toward

Narasayya, Vivek

62

Interpreting carbon-isotope excursions: carbonates and organic matter  

Microsoft Academic Search

Variations in the carbon isotopic compositions of marine carbonate and organic carbon provide a record of changes in the fraction of organic carbon buried through time and may provide clues to changes in rates of weathering and sources of organic carbon. Paired carbonate and organic carbon isotope determinations provide a possibility of interpreting not only changes in the global carbon

Lee R. Kump; Michael A. Arthur

1999-01-01

63

Carbon Code Requirements for voluntary carbon sequestration projects  

E-print Network

Woodland Carbon Code Requirements for voluntary carbon sequestration projects ® Version 1.2 July trademark 10 3. Carbon sequestration 11 3.1 Units of carbon calculation 11 3.2 Carbon baseline 11 3.3 Carbon leakage 12 3.4 Project carbon sequestration 12 3.5 Net carbon sequestration 13 4. Environmental quality 14

64

Carbon dioxide sequestration by mineral carbonation  

Microsoft Academic Search

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

W. J. J. Huijgen; R. N. J. Comans

2007-01-01

65

Carbon-carbon grid for ion engines  

NASA Technical Reports Server (NTRS)

A method and apparatus of manufacturing a grid member for use in an ion discharge apparatus provides a woven carbon fiber in a matrix of carbon. The carbon fibers are orientated to provide a negatibe coefficient of thermal expansion for at least a portion of the grid member's operative range of use.

Garner, Charles E. (inventor)

1993-01-01

66

Carbon monoxide  

PubMed Central

Carbon monoxide (CO), a by-product released during the degradation of heme by heme oxygenases (HOS EC 1.14.99.3) in animals, plays a major role as neurotransmitter, regulator of sinusoidal tone, inhibitor of platelet aggregation and suppressor of acute hypertensive response, and most of above effects are similar to or mediated by nitric oxide (NO), another signal molecule in both the animal and plant kingdoms. Previous result demonstrated that NO could act as a promoter of plant cell elongation, acting similarly to IAA, inducing morphogenetic responses leading to expansion in plant tissues. Recent observations revealed that CO is an inducer of cell expansion in wheat root segments, acting similarly to IAA and NO. Evidence also indicated that IAA could result in either the potent induction of HO-1 transcript or endogenous CO releasing in wheat root segments. Additionally, our results suggested that above CO signaling might be related to NO/cGMP, Ca2+ and even ROS-dependent pathways. In this addendum, combined with other previous results, we further proposed a possible hypothesis for CO signaling role in regulation of plant root development induced by auxin. PMID:19704571

Xuan, Wei; Xu, Sheng; Yuan, Xingxing

2008-01-01

67

Carbon Cycle Diagram  

NSDL National Science Digital Library

This diagram illustrates some of the most abundant stores of carbon and identifies some of the pathways in the carbon cycle along which carbon is transferred from one form to another. Long-term sinks of carbon are labelled in black; shorter-term fluxes are labelled in purple. Amounts are in billions of tons.

2011-07-12

68

Carbon Journey Game  

NSDL National Science Digital Library

This hands-on activity is a kinesthetic game illustrating the dynamics of the carbon cycle. Acting as carbon atoms, students travel from one carbon reservoir to another; at each reservoir they determine, by rolling dice, how long they stay in the reservoir or how likely it is that they will move to another carbon reservoir.

Andrill; Framework, Environmental L.

69

The Woodland Carbon Code  

E-print Network

The Woodland Carbon Code While society must continue to make every effort to reduce greenhouse gas that schemes will actually deliver the carbon savings that they claim. The Woodland Carbon Code will provide that reassurance. The voluntary code will encourage a consistent approach to woodland carbon projects, and offer

70

Dynamic carbon footprinting  

Microsoft Academic Search

The early focus by individual businesses on the reduction of their own carbon footprint is being superseded by a phase of building carbon-constrained business networks. Across these networks, businesses evaluate each others' footprints and conduct business accordingly. Dynamic carbon footprinting is emerging as a powerful tool for guiding operational logic and business transformation into the carbon-constrained markets, with delivery of

Michael Gell

2008-01-01

71

Acetylenic carbon allotrope  

DOEpatents

A fourth allotrope of carbon, an acetylenic carbon allotrope, is described. The acetylenic carbon allotropes of the present invention are more soluble than the other known carbon allotropes in many common organic solvents and possesses other desirable characteristics, e.g. high electron density, ability to burn cleanly, and electrical conductive properties. Many uses for this fourth allotrope are described herein. 17 figs.

Lagow, R.J.

1998-02-10

72

Acetylenic carbon allotrope  

DOEpatents

A fourth allotrope of carbon, an acetylenic carbon allotrope, is described. The acetylenic carbon allotropes of the present invention are more soluble than the other known carbon allotropes in many common organic solvents and possesses other desirable characteristics, e.g. high electron density, ability to burn cleanly, and electrical conductive properties. Many uses for this fourth allotrope are described herein.

Lagow, Richard J. (6204 Shadow Mountain Dr., Austin, TX 78731)

1999-01-01

73

Acetylenic carbon allotrope  

DOEpatents

A fourth allotrope of carbon, an acetylenic carbon allotrope, is described. The acetylenic carbon allotropes of the present invention are more soluble than the other known carbon allotropes in many common organic solvents and possesses other desirable characteristics, e.g. high electron density, ability to burn cleanly, and electrical conductive properties. Many uses for this fourth allotrope are described herein.

Lagow, Richard J. (6204 Shadow Mountain Dr., Austin, TX 78731)

1998-01-01

74

Acetylenic carbon allotrope  

Microsoft Academic Search

A fourth allotrope of carbon, an acetylenic carbon allotrope, is described. The acetylenic carbon allotropes of the present invention are more soluble than the other known carbon allotropes in many common organic solvents and possesses other desirable characteristics, e.g. high electron density, ability to burn cleanly, and electrical conductive properties. Many uses for this fourth allotrope are described herein. 17

Lagow

1998-01-01

75

Acetylenic carbon allotrope  

SciTech Connect

A fourth allotrope of carbon, an acetylenic carbon allotrope, is described. The acetylenic carbon allotropes of the present invention are more soluble than the other known carbon allotropes in many common organic solvents and possesses other desirable characteristics, e.g. high electron density, ability to burn cleanly, and electrical conductive properties. Many uses for this fourth allotrope are described herein.

NONE

1999-11-16

76

Carbon Monoxide Environmental Public  

E-print Network

Staets1979 through 1988. JAMA 1991;266:659-63 3. Ernst A, Zibrak JD. Carbon monoxide poisoning. N Engl J.graber@maine.gov #12;EPHT Branch Monthly Brown BagEPHT Branch Monthly Brown Bag ---- Carbon Monoxide PoisoningCarbon-based surveillance system for carbon monoxide poisoning Judith M. Graber, M.S. Andrew E. Smith, Sc.D. Maine

77

Carbon Cycle Game  

NSDL National Science Digital Library

In this interactive, regionally-relevant carbon cycle game, students are challenged to understand the role of carbon in global climate change. They imagine that they are carbon molecules and travel via different processes through carbon reservoirs on the Colorado Plateau (the Four Corners area of Arizona, Colorado, New Mexico and Utah). This game can be adapted to other regions.

Partnership, Colorado P.; Northern Arizona University; Biological Sciences Curriculum Study

78

Pyrolyzed thin film carbon  

NASA Technical Reports Server (NTRS)

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.

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

2010-01-01

79

Automotive high color carbon  

SciTech Connect

A method of making a low porosity carbon black is described comprising: (1) feeding into a carbon black reactor a carbonaceous feed; (2) contacting the feed in the reactor with combustion gases containing oxygen thereby cracking the feed to produce carbon black; and (3) contacting the produced carbon black in the reactor with vaporizable hydrocarbon oil injected into the reaction at a point where the carbon black forming reaction is substantially complete to at least partially quench the carbon black producing reaction, the vaporizable hydrocarbon oil being cracked and serving to plate the carbon black to reduce the porosity thereof.

Ducote, R.E.; Dees, R.G.; Musick, V.L.

1988-06-14

80

Carbon/Carbon extendible Nozzles  

NASA Astrophysics Data System (ADS)

For many years, SEP has developed C-C composite materials to lighten architectures of propulsion systems, thanks to their high specific mechanical properties kept up to about 2500°C. The 3D carbon reinforcement the so-called Novoltex ® has emerged, and today more than 150 tons per year of C-C is produced by SEP using it. The advent of these thermostructural composite materials have blazed a trail for innovative solutions applicable to the extreme operating conditions of large rocket engines, to improve their performances. The extendible nozzle concept has been developed to optimize the expansion ratio with regard to size restriction required particularly for the upper stages of launchers. The first two tests of a SEP extendible nozzle extension were carried out in 1979, one on a ring design and one on a panel design. Today, nearly all possible configurations have been tested, from the simple scenario of extending a ring from a fixed nozzle prior to ignition, to the most complex one: nozzle deployment while the motor is operating and when the nozzle is being vectored. In August 1995, Pratt & Whitney have entrusted SEP with the development of the C-C exit cone dedicated to the RL10 B-2 cryotechnic engine, propulsion system of the DELTA III upper stage. One year later, in August 1996, SEP delivered the first development item which is currently under testing. When the entire C-C nozzle is attached to the RL10 B-2 engine and deployed, the nozzle diameter increases from 1.1 to 2.1 m and translates to 2.5 m in length, providing an expansion ratio of 285:1 and 30 s of specific impulse increase to the engine. Finally, the paper will describe the design and manufacturing of this huge exit cone and will report the latest test results.

Lacoste, M.; Lacombe, A.; Joyez, P.; Ellis, R. A.; Lee, J. C.; Payne, F. M.

2002-03-01

81

Carbon Dioxide Emissions and Carbonation Sensors  

Microsoft Academic Search

The gases with higher heat capacities than those of O2 and N2 cause greenhouse effects. Carbon dioxide (CO2) is the main greenhouse gas associated with global climate change. At the present time, coal is responsible for 30–40% of world CO2 emissions from fossil fuels. There was a higher correlation between the amount of carbon dioxide emission and percentage of carbon

A. Demirbas

2007-01-01

82

Method of making carbon-carbon composites  

Microsoft Academic Search

A method for fabricating a high-strength, high-modulus and high thermal and electrical conducting 2D laminate carbon-carbon composite is described comprising the steps of: (a) forming a green laminate composite comprising: (1) graphitizible carbon cloth plies, (2) fine graphitizible pitch powder; said cloth plies comprising mesophase derived pitch fiber tow with moduli in a range of 25 to 140 Msi, and

Engle

1993-01-01

83

Method of making carbon-carbon composites  

Microsoft Academic Search

A process for making a carbon-carbon composite having a combination of high crystallinity, high strength, high modulus and high thermal and electrical conductivity. High-modulus\\/high-strength mesophase derived carbon fibers are woven into a suitable cloth. Layers of this easily graphitizable woven cloth are covered with petroleum or coal tar pitch and pressed at a temperature a few degrees above the softening

Engle; Glen B

1991-01-01

84

Method of making carbon-carbon composites  

Microsoft Academic Search

A process is described for making a carbon-carbon composite having a combination of high crystallinity, high strength, high modulus and high thermal and electrical conductivity. High-modulus\\/high-strength mesophase derived carbon fibers are woven into a suitable cloth. Layers of this easily graphitizable woven cloth are covered with petroleum or coal tar pitch and pressed at a temperature a few degrees above

Engle

1991-01-01

85

Carbon fuel cells with carbon corrosion suppression  

DOEpatents

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.

Cooper, John F. (Oakland, CA)

2012-04-10

86

Modern carbonate environments  

SciTech Connect

This book offers help in evaluating potential sites for oil and gas accumulations. Pointing the way to discovery of hydrocarbons in carbonate reservoirs, this volume discusses modern carbonate depositional environments in different geomorphic settings. It compiles papers by scientists whose observations have revolutionized current thinking on facies relationships in ancient carbonate rock. Contents include: Selected carbonate regions --The Algal Sediments on Androa Island in the Bahamas, Sedimentary Facies, Interaction of Genetic Processes in Holocene Reefs off North Eleuthera Island in the Bahamas, Recent Anhydrite, Holocene Shallow-Water Carbonate and Evaporite Sediments of Khor al Bazam; Carbonate production--On the Origin of Aragonite in the Dead Sea, Carbonate Production by Coral Reefs; Cold-water carbonates--Contributions on the Geology of the Northwestern Peninsula of Iceland, Evaluation of Cold-Water Carbonates as a Possible Paleoclimatic Indicator.

Bhattacharyya, A.; Friedman, G.M.

1983-01-01

87

The Carbon Cycle  

NSDL National Science Digital Library

This Earth Observatory site contains detailed information on the carbon cycle of the Earth. It provides an explanation of the role of carbon in the geologic carbon cycle followed by a discussion of carbon in the life process, including photosynthesis and respiration. Carbon sinks on land and in the ocean are covered next, followed by the human role in the cycle. Lastly, the activity of the National Aeronautics and Space Administration, (NASA), and that of the National Oceanic and Atmospheric Administration, (NOAA) in the exploration of the connection of the carbon cycle to weather and climate is covered.

2011-04-27

88

The effect of carbon nanotube growing on carbon fibers on the microstructure of the pyrolytic carbon and the thermal conductivity of carbon\\/carbon composites  

Microsoft Academic Search

Carbon nanotubes were prepared on the surface of carbon fibers in a unidirectional carbon preform and then chemical vapor deposition was used to densify the preform to get a modified carbon\\/carbon composite. The effects of carbon nanotubes on the microstructure of the pyrolytic carbon and the thermal conductivity of the composite were investigated. Results show that carbon nanotubes on the

Jie Chen; Xiang Xiong; Peng Xiao

2009-01-01

89

Method of making carbon-carbon composites  

DOEpatents

A process for making a carbon-carbon composite having a combination of high crystallinity, high strength, high modulus and high thermal and electrical conductivity. High-modulus/high-strength mesophase derived carbon fibers are woven into a suitable cloth. Layers of this easily graphitizable woven cloth are covered with petroleum or coal tar pitch and pressed at a temperature a few degrees above the softening point of the pitch to form a green laminated composite. The green composite is restrained in a suitable fixture and heated slowly to carbonize the pitch binder. The carbonized composite is then impregnated several times with pitch by covering the composite with hot pitch under pressure. The composites are given a heat treatment between each impregnation step to crack up the infiltrated carbon and allow additional pitch to enter the microstructure during the next impregnation cycle. The impregnated composites are then given a final heat treatment in the range 2500.degree. to 3000.degree. C. to fully graphitize the fibers and the matrix carbon. The composites are then infiltrated with pyrolytic carbon by chemical vapor deposition in the range 1000.degree. to 1300.degree. C. at a reduced pressure for approximately one hundred and fifty (150) hours.

Engle, Glen B. (16716 Martincoit Rd., Poway, CA 92064)

1991-01-01

90

Carbon Monoxide Safety Tips  

E-print Network

Protect yourself and your family from the deadly effects of carbon monoxide--a colorless, odorless poisonous gas. This publication describes the warning signs of carbon monoxide exposure and includes a home safety checklist....

Shaw, Bryan W.; Garcia, Monica L.

1999-07-26

91

Carbon Based Nanotechnology: Review  

NASA Technical Reports Server (NTRS)

This presentation reviews publicly available information related to carbon based nanotechnology. Topics covered include nanomechanics, carbon based electronics, nanodevice/materials applications, nanotube motors, nano-lithography and H2O storage in nanotubes.

Srivastava, Deepak; Saini, Subhash (Technical Monitor)

1999-01-01

92

Calcium carbonate overdose  

MedlinePLUS

... is an ingredient that is commonly found in antacids (for heartburn) and some dietary supplements. Calcium carbonate ... Products containing calcium carbonate, including Certain antacids ... mineral supplements Note: This list may not be all-inclusive.

93

Preliminary study of iridium coating on carbon\\/carbon composites  

Microsoft Academic Search

Iridium coating was deposited on as-received, polished and chemical vapour deposited (CVD) pyro carbon-coated carbon\\/carbon composite by d.c. sputtering. The as-received surface of the carbon\\/carbon composite was not fully covered by an iridium coating up to 12 µm thick, whereas better deposition and surface coverage with the iridium coating were obtained on the polished surface and CVD pyro carbon-coated carbon\\/carbon

K. Mumtaz; J. Echigoya; M. Taya

1993-01-01

94

Understanding the Carbon Cycle  

NSDL National Science Digital Library

In this unit, students use Internet resources, slide presentations, and modeling to explain how understanding the carbon cycle helps scientists understand and prepare for global climate change, what might happen if sources of carbon produced more than sinks could remove, and what might happen if sinks absorbed more than sources produced. They should understand how the carbon cycle affects various life forms and the role that carbon plays in their lives. Procedures, a glossary, assessments, and scoring rubrics are provided.

95

Metal filled porous carbon  

DOEpatents

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.

Gross, Adam F. (Los Angeles, CA); Vajo, John J. (West Hills, CA); Cumberland, Robert W. (Malibu, CA); Liu, Ping (Irvine, CA); Salguero, Tina T. (Encino, CA)

2011-03-22

96

Carbon Cycle Roleplay  

NSDL National Science Digital Library

In this creative roleplay activity, learners will explore the various processes of the carbon cycle using movement and props to aid in comprehension. Learners will understand that carbon changes forms throughout the carbon cycle, and that carbon is continuously moving throughout all the cycles at the same time. This standards-based lesson, which is great for the classroom, camps, or afterschool programs, includes roleplay cards and ideas for props.

Sciences, California A.

2008-01-01

97

Carbon dioxide power cycle  

Microsoft Academic Search

An improved direct fired power system generating and employing a combustion gas which includes carbon dioxide or a working fluid including a combustion chamber for burning a mixture which includes oxygen, carbonaceous fuel and recycled carbon dioxide working fluid at a first pressure of above 1100 PSI thereby providing a combustion gas which includes carbon dioxide and water at substantially

Osgerby

1985-01-01

98

Carbon Footprint Towson University  

E-print Network

Carbon Footprint Towson University GHG Inventory for Educational Institutes Getting Starting.TM The Carbon Footprint 8 The Constellation Experience A Broad Inventory 1. Scope I-Direct Emissions works.TM The Carbon Footprint 10 The Constellation Experience A Broad Inventory 3. Scope III

Fath, Brian D.

99

Naturally produced carbon nanotubes  

Microsoft Academic Search

Carbon nanotubes represent an impressive kind of materials with diverse unexpected properties, and different methods to artificially produce them have been developed. Recently, they have also been synthesized at low temperatures, demonstrating that these materials might exist in fluids or carbon rocks of the Earth’s crust. A new type of natural encapsulated carbon nanotubes found in a coal–petroleum mix is

C. Velasco-Santos; A. L. Mart??nez-Hernández; A. Consultchi; R. Rodr??guez; V. M. Castaño

2003-01-01

100

Molten Carbonate Fuel Cell  

NSDL National Science Digital Library

This page is an introduction to the Molten Carbonate fuel cell. It uses flash animation to explain in greater detail what the Molten Carbonate fuel cell consists of and how it works. The website has an introductory animation which is followed by more in depth description of the molten carbonate fuel cell works.

2010-09-08

101

Intro to Carbon Sequestration  

ScienceCinema

NETL's Carbon Sequestration Program is helping to develop technologies to capture, purify, and store carbon dioxide (CO2) in order to reduce greenhouse gas emissions without adversely influencing energy use or hindering economic growth. Carbon sequestration technologies capture and store CO2 that would otherwise reside in the atmosphere for long periods of time.

None

2010-01-08

102

Carbon Goes To…  

ERIC Educational Resources Information Center

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…

Savasci, Funda

2014-01-01

103

ESM 271 Carbon Footprints and Carbon Accounting Instructor: Sangwon Suh  

E-print Network

1 ESM 271 Carbon Footprints and Carbon Accounting Instructor: Sangwon Suh Bren hall 3422, suh Week 1: Introduction to carbon footprint and carbon account - Background: carbon awareness, major out a report or a web site about carbon footprint results of a product or of a company. Write a two

California at Santa Barbara, University of

104

SmallholderSmallholder CarbonCarbon AgroforestryAgroforestry && Carbon for Poverty ReductionCarbon for Poverty Reduction  

E-print Network

SmallholderSmallholder CarbonCarbon AgroforestryAgroforestry && Carbon for Poverty ReductionCarbon for Poverty Reduction Roundtable (CAPR)Roundtable (CAPR) GEO Forest Monitoring SymposiumGEO Forest Monitoring)Amazon Initiative Consortium (IA) #12;Carbon for Poverty Reduction Roundtable (CAPR)Carbon for Poverty Reduction

105

Templated nanoscale porous carbons.  

PubMed

This manuscript reviews key developments in the important and rapidly expanding area of templated porous carbons. The porosity covered ranges from microporous to mesoporous and macroporous carbons. Two modes of templating, using so-called hard and soft templates, are covered. In particular, for hard templating, zeolite templating generates microporous carbons, mesoporous silicates yield mesoporous carbons, while colloidal particles are replicated to large mesoporous and macroporous carbons. Soft-templating, a more recent phenomenon, mainly generates mesoporous carbons. The full range of pore sizes can therefore now be accessed using hard and soft templates to generate highly ordered nanoscale carbons with well-defined and optimised textural properties. The research area has seen rapid and important developments over the last few years, and this review aims to present the more significant advances. PMID:20648305

Xia, Yongde; Yang, Zhuxian; Mokaya, Robert

2010-05-01

106

Carbon/Carbon for satellite applications  

NASA Astrophysics Data System (ADS)

Carbon/Carbon has many attributes that make it an attractive material for satellite applications. It is low in density, is dimensionally stable under a wide variety of conditions, has very low thermal expansion, is relatively low in cost, and is a mature technology. Moreover, the material is flexible enough to enable the designer to select such variables as fiber type, fabric architecture, fiber volume, and high temperature processing and thus custom tailor the physical and mechanical properties to his specific requirements. A wide range of properties are available - densities from 1.5 to 1.9 g/cm3, room temperature Coefficients of Thermal Expansion (CTE) from -0.3x10-6to -1.3x10-6/K, room temperature thermal conductivities from 7 to 210 W/m.K, and modulus from 60 to 190 GPa. A new type of structure developed by CNRS on the space instrument SODISM uses Carbon/Carbon.

Meftah, M.; Lee, S.; Irbah, A.; Ostergren, S.

2011-06-01

107

Process of making carbon-carbon composites  

NASA Technical Reports Server (NTRS)

A carbon composite structure, for example, an automotive engine piston, is made by preparing a matrix including of a mixture of non crystalline carbon particulate soluble in an organic solvent and a binder that has a liquid phase. The non crystalline particulate also contains residual carbon hydrogen bonding. An uncured structure is formed by combining the matrix mixture, for example, carbon fibers such as graphite dispersed in the mixture and/or graphite cloth imbedded in the mixture. The uncured structure is cured by pyrolyzing it in an inert atmosphere such as argon. Advantageously, the graphite reinforcement material is whiskered prior to combining it with the matrix mixture by a novel method involving passing a gaseous metal suboxide over the graphite surface.

Withers, James C. (Inventor); Loutfy, Raouf O. (Inventor); Kowbel, Witold (Inventor); Bruce, Calvin (Inventor); Vaidyanathan, Ranji (Inventor)

2000-01-01

108

Variable Carbon Isotopes in ALH84001 Carbonates  

Microsoft Academic Search

The Martian meteorite ALH84001 contains a small amount of carbonate that was deposited from aqueous fluids on the Martian surface approximately 3.9 Ga.. McKay et al. (1996) proposed evidence for the existence of life preserved within the carbonate grains. In order to determine the nature of the ancient Martian aqueous system we have combined previously collected oxygen isotopic data with

P. B. Niles; L. A. Leshin; Y. Guan

2002-01-01

109

Hypervelocity technology carbon\\/carbon testing  

Microsoft Academic Search

The paper describes the procedures used at the Structures Test Laboratory of the Wright Laboratory's Flight Dynamics Directorate to test a carbon\\/carbon hot structure representing a typical hypersonic gliding body, and presents the results of tests. The forebody was heated to 1371 C over 13 test runs, using radiant quartz lamps; a vertical shear force of 5.34 kN was introduced

John V. Anselmo; Lawrence O. Kretz

1991-01-01

110

High performance carbon-carbon composites  

Microsoft Academic Search

Carbon-carbon composites rank first among ceramic composite materials with a spectrum of properties and applications in various\\u000a sectors. These composites are made of fibres in various directions and carbonaceous polymers and hydrocarbons as matrix precursors.\\u000a Their density and properties depend on the type and volume fraction of reinforcement, matrix precursor used and end heat treatment\\u000a temperature. Composites made with thermosetting

Lalit M. Manocha

2003-01-01

111

Mechanical behavior of carbon-carbon composites  

NASA Technical Reports Server (NTRS)

A general background, test plan, and some results of preliminary examinations of a carbon-carbon composite material are presented with emphasis on mechanical testing and inspection techniques. Experience with testing and evaluation was gained through tests of a low modulus carbon-carbon material, K-Karb C. The properties examined are the density - 1.55 g/cc; four point flexure strength in the warp - 137 MPa (19,800 psi) and the fill - 95.1 MPa (13,800 psi,) directions; and the warp interlaminar shear strength - 14.5 MPa (2100 psi). Radiographic evaluation revealed thickness variations and the thinner areas of the composite were scrapped. The ultrasonic C-scan showed attenuation variations, but these did not correspond to any of the physical and mechanical properties measured. Based on these initial tests and a survey of the literature, a plan has been devised to examine the effect of stress on the oxidation behavior, and the strength degradation of coated carbon-carbon composites. This plan will focus on static fatigue tests in the four point flexure mode in an elevated temperature, oxidizing environment.

Rozak, G. A.

1984-01-01

112

Activated carbon from biomass  

NASA Astrophysics Data System (ADS)

Activated carbon are unique and versatile adsorbents having extended surface area, micro porous structure, universal adsorption effect, high adsorption capacity and high degree of surface reactivity. Activated carbons are synthesized from variety of materials. Most commonly used on a commercial scale are cellulosic based precursors such as peat, coal, lignite wood and coconut shell. Variation occurs in precursors in terms of structure and carbon content. Coir having very low bulk density and porous structure is found to be one of the valuable raw materials for the production of highly porous activated carbon and other important factor is its high carbon content. Exploration of good low cost and non conventional adsorbent may contribute to the sustainability of the environment and offer promising benefits for the commercial purpose in future. Carbonization of biomass was carried out in a horizontal muffle furnace. Both carbonization and activation were performed in inert nitrogen atmosphere in one step to enhance the surface area and to develop interconnecting porosity. The types of biomass as well as the activation conditions determine the properties and the yield of activated carbon. Activated carbon produced from biomass is cost effective as it is easily available as a waste biomass. Activated carbon produced by combination of chemical and physical activation has higher surface area of 2442 m2/gm compared to that produced by physical activation (1365 m2/gm).

Manocha, S.; Manocha, L. M.; Joshi, Parth; Patel, Bhavesh; Dangi, Gaurav; Verma, Narendra

2013-06-01

113

Molten carbonate fuel cell separator  

DOEpatents

In a stacked array of molten carbonate fuel cells, a fuel cell separator is positioned between adjacent fuel cells to provide isolation as well as a conductive path therebetween. The center portion of the fuel cell separator includes a generally rectangular, flat, electrical conductor. Around the periphery of the flat portion of the separator are positioned a plurality of elongated resilient flanges which form a gas-tight seal around the edges of the fuel cell. With one elongated flange resiliently engaging a respective edge of the center portion of the separator, the sealing flanges, which are preferably comprised of a noncorrosive material such as an alloy of yttrium, iron, aluminum or chromium, form a tight-fitting wet seal for confining the corrosive elements of the fuel cell therein. This arrangement permits a good conductive material which may be highly subject to corrosion and dissolution to be used in combination with a corrosion-resistant material in the fuel cell separator of a molten carbonate fuel cell for improved fuel cell conductivity and a gas-tight wet seal.

Nickols, R.C.

1984-10-17

114

Carbon black enriched combustion  

SciTech Connect

A process for combustion of carbon black enriched gaseous hydrocarbon fuels is described comprising: entraining a plurality of carbon black particles in a carrier fluid, forming a carbon black/carrier fluid mixture; injecting said carbon black/carrier fluid mixture through a center nozzle of a fluid injector into a combustion chamber, said fluid injector having an outer nozzle concentrically disposed around said center nozzle forming an annular chamber between said center nozzle and said outer nozzle; injecting at least a first portion of a gaseous hydrocarbon fuel through said annular chamber into said combustion chamber forming a carbon black enriched gaseous hydrocarbon fuel; mixing said carbon black enriched gaseous hydrocarbon fuel with combustion air, forming a fuel/air mixture; and igniting said fuel/air mixture.

Joshi, M.L.; Tester, M.E.

1993-06-29

115

Mesoporous carbon materials  

DOEpatents

The invention is directed to a method for fabricating a mesoporous carbon material, the method comprising subjecting a precursor composition to a curing step followed by a carbonization step, the precursor composition comprising: (i) a templating component comprised of a block copolymer, (ii) a phenolic compound or material, (iii) a crosslinkable aldehyde component, and (iv) at least 0.5 M concentration of a strong acid having a pKa of or less than -2, wherein said carbonization step comprises heating the precursor composition at a carbonizing temperature for sufficient time to convert the precursor composition to a mesoporous carbon material. The invention is also directed to a mesoporous carbon material having an improved thermal stability, preferably produced according to the above method.

Dai, Sheng; Wang, Xiqing

2013-08-20

116

Land plants, carbon isotopes and the late Paleozoic carbon cycle  

Microsoft Academic Search

Two parameters determine the carbon isotopic composition of plant tissue: the carbon isotopic composition of atmospheric carbon dioxide and the carbon isotopic fractionation associated with plant metabolism. Based on a systematic survey of terrestrial organic matter, we present a carbon isotope record for the late Paleozoic. Investigations directed towards sample type, maturity and host lithology indicate that near primary isotopic

W. Peters-Kottig; H. Strauss; H. Kerp

2003-01-01

117

Smooth-Surfaced Carbon/Carbon Reflector Panels  

NASA Technical Reports Server (NTRS)

Surface-densification technique integral to fabrication of reflective, lightweight, low-outgassing radio-antenna-reflector panels including carbon/carbon surface laminates supported by carbon/carbon core structures. Densification prevents "print-through" of carbon fibers on surface. When properly densified, surface polished to smooth finish.

Schmitigal, Wesley P.; Jacoy, Paul J.; Porter, Christopher C.; Hickey, Gregory S.

1992-01-01

118

Carbon Sequestration via Mineral Carbonation: Overview and Assessment  

E-print Network

1 Carbon Sequestration via Mineral Carbonation: Overview and Assessment 14 March 2002 Howard Herzog overview and assessment of carbon sequestration by mineral carbonation (referred to as "mineral sequestration R&D. The first is that carbonates have a lower energy state than CO2. Therefore, at least

119

Introduction of nanostructures in carbon–carbon composites  

Microsoft Academic Search

The properties of carbon–carbon composites are predominantly dictated by the microstructure of carbon reinforcement and matrix system. In order to control this, studies were undertaken on the effect of introduction of nanostructured carbons in fibers as well as matrix system on microstructure of modified composites. Composites were made with vapour grown carbons, thermosetting (polyfurfuryl alcohol) as well as isotropic and

L. M. Manocha

2005-01-01

120

The carbon dioxide cycle  

USGS Publications Warehouse

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.

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

2005-01-01

121

The Carbon Cycle  

NSDL National Science Digital Library

Since living things extract carbon from their nonliving environment, for life to continue carbon must be recycled. This site tells us that the cycle is not in balance and explores the possibilities of where the missing carbon might be found. The site also explains the greenhouse effect and global warming and also covers the other greenhouse gases such as methane and chlorofluorocarbons (CFCs). It also features diagrams, a graph, and links to other sites for more detailed information.

Kimball, John

122

Why is Carbon Important?  

NSDL National Science Digital Library

Students explore the carbon cycle and the relationship between atmospheric carbon dioxide concentrations and temperature. Students create and compare graphs of carbon dioxide and temperature data from one local (Mauna Loa, Hawaii) meteorological station and one NASA global data set. These graphs, as well as a global vegetation map and an atmospheric wind circulation patterns diagram, are used as evidence to support the scientific claims they develop through their analysis and interpretation.

Center, Nasa G.

123

Seeing the Carbon Cycle  

NSDL National Science Digital Library

The most important biochemical reactions for life in the ocean and on Earth are cellular respiration and photosynthesis. These two reactions play a central role in the carbon cycle. The ocean-based carbon cycle is highly relevant to today's students because of its key role in global warming. This experiment allows middle school students to observe the influence of the carbon cycle on algae growth, explore experimental design, collect data, and draw a conclusion.

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

2006-01-01

124

Carbon plasma gun  

SciTech Connect

A family of plasma guns supplying highly ionized carbon plasma is described. The guns are simple and inexpensive to construct and are pulsed by small capacitor banks of a few hundred joules. The output consists of 10/sup 17/--10/sup 18/ multiply ionized carbon ions traveling at about 10/sup 7/ cm/s. Neutral output is very low and arrives well after the ionized carbon. The guns and pulsers are very reliable.

Mendel, C.W. Jr.; Zagar, D.M.; Mills, G.S.; Humphries, S. Jr.; Goldstein, S.A.

1980-12-01

125

USGS Carbon Cycle Research  

NSDL National Science Digital Library

This portal provides access to information on United States Geological Survey (USGS) research activities conducted in support of the U.S. Carbon Cycle Science Program (CCSP). This research includes carbon sequestration in sediments, landscape dynamics and vegetation change, fate of carbon in cold region forests, exchanges of greenhouse gases, water vapor, and heat at the Earth's surface, and other topics. Each topic heading features links to reports or program webpages.

126

Reinforced Carbon Nanotubes.  

DOEpatents

The present invention relates generally to reinforced carbon nanotubes, and more particularly to reinforced carbon nanotubes having a plurality of microparticulate carbide or oxide materials formed substantially on the surface of such reinforced carbon nanotubes composite materials. In particular, the present invention provides reinforced carbon nanotubes (CNTs) having a plurality of boron carbide nanolumps formed substantially on a surface of the reinforced CNTs that provide a reinforcing effect on CNTs, enabling their use as effective reinforcing fillers for matrix materials to give high-strength composites. The present invention also provides methods for producing such carbide reinforced CNTs.

Ren, Zhifen (Newton, MA); Wen, Jian Guo (Newton, MA); Lao, Jing Y. (Chestnut Hill, MA); Li, Wenzhi (Brookline, MA)

2005-06-28

127

Wildland Soil Carbon Management  

NASA Astrophysics Data System (ADS)

In the era of climate change, traditional wildland management practices have come into question, especially with respect to their impact on soil carbon sequestration. Over half of the land area of the United States and Puerto Rico is either in forest or grassland ecosystems, i.e. 302 million hectares of forested lands and 247 million hectares of grasslands and pasture lands. Forested lands hold approximately 35.5 Pg of soil carbon to a depth of 100cm. Private grasslands hold approximately 21 Pg of soil carbon to a depth of 200cm. The difficulty of managing for carbon sequestration becomes more evident when one surveys the variety of complex ecosystems being managed. This presentation highlights implications for wildland management for promoting soil carbon sequestration for sustaining forest and grassland ecosystems in the United States. We will address key considerations, strategies, and opportunities to incorporate soil carbon management into wildland management. Examples of vegetation management influence on soil carbon will be discussed including fire, soil amendments and best management practices for maintaining and/or improving soil carbon sequestration. The USDA Forest Service has established a soil management policy that seeks to conserve soil quality and protect soil carbon on National Forest System lands. Aspects of this national policy will also be presented.

Davis, R. L.; Swanston, C.

2009-12-01

128

Naturally produced carbon nanotubes  

NASA Astrophysics Data System (ADS)

Carbon nanotubes represent an impressive kind of materials with diverse unexpected properties, and different methods to artificially produce them have been developed. Recently, they have also been synthesized at low temperatures, demonstrating that these materials might exist in fluids or carbon rocks of the Earth's crust. A new type of natural encapsulated carbon nanotubes found in a coal-petroleum mix is presented. These findings show that all allotropic carbon forms known up to date can be produced in Nature, where pressure, catalysts particles, shear stress and parameters other than exclusively very high temperature, seem to play an important role for producing nanotubes.

Velasco-Santos, C.; Martínez-Hernández, A. L.; Consultchi, A.; Rodríguez, R.; Castaño, V. M.

2003-05-01

129

The Growth and Characterization of Germanium-Carbon Alloy Thin Films and Solid Phase Equilibria for Metal-Silicon - Ternary Systems: Magnesium, Calcium, Strontium, Barium, Scandium, Yttrium, Lanthanum, Titanium, Zirconium and Hafnium  

NASA Astrophysics Data System (ADS)

Thin films of pure germanium-carbon alloys (Ge _{rm x}C _{rm 1-x} with 0 <=q x <=q 1) have been grown on Si and Al_2O_3 substrates by pulsed laser ablation in a high vacuum chamber. The films were analyzed by x-ray 0-20 diffraction (XRD), x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), conductivity measurements and optical absorption spectroscopy. The analyses of these new materials showed that films of all compositions were amorphous, free of contamination and uniform in composition. By changing the film composition, the optical band gap of these semiconducting films was varied from 0.00 eV to 0.85 eV for x = 0.0 to 1.0 respectively. According to the AES results, the carbon atoms in the Ge-C alloy thin film samples have a bonding structure that is a mixture of sp^2 and sp^3 hybridizations. The presence of the sp^2 C is apparently what causes the bandgap of amorphous Ge-C alloys to decrease with increasing carbon concentration. The solidus portion of the ternary phase diagrams of the type M-Si-O, where M = Mg, Ca, Sr, Ba, Sc, Y, La, Ti, Zr and Hf have been derived at 298K and 1 atm oxygen partial pressure by investigating the bulk reactions possible in these systems. These phase diagrams, which have been determined by experiments and by calculations using thermodynamic data available, can be used to predict the occurrence of the reaction products or the stability of the phases present at the interfaces between different solid materials. Hence, they provide guides in designing thin film structures and in selecting candidate materials to form chemically stable interfaces. A research effort has been made on the investigation of the growth of diamond thin films from a carbon containing solid-CI_4, using laser ablation technique. The film grown by laser ablation from CI _4 is mainly composed of carbon with very small amount of oxygen and iodine as indicated by x-ray photoelectron spectroscopy data. The Auger electron spectroscopy result shows that the film grown contains a mixture of sp^2 and sp^3 hybridized carbon. By using x-ray powder diffraction and magnetic susceptibility measurements methods, we studied the chemical stability of candidate interlayer materials between YBa _2Cu_3O _7-delta and Si. The results show that CaF_2 reacts with YBCO while BaF_2 is chemically stable with YBCO. LaGaO_3 and Ca _2SiO_4 are chemically stable with Si and more investigations need to be made on the reactivity between Ca_2SiO _4 and YBCO.

Yuan, Haojie

1992-09-01

130

Thermal conductivity of unidirectional carbon\\/carbon composites with different carbon matrixes  

Microsoft Academic Search

Unidirectional carbon\\/carbon preforms were densified using resin and mesophase pitch, respectively. The microstructure and thermal properties of the carbon\\/carbon composites with different carbon matrixes were investigated. The results show that resin carbon has a lower micro-orientation (micro-graphitization degree) and combines loosely with carbon fibers, having obvious interface cracks. Due to the specific properties of mesophase pitch, it can arrange along

Chen Jie; Xiong Xiang; Xiao Peng

2009-01-01

131

Carbon-based resistive memory  

Microsoft Academic Search

We propose carbon as new resistive memory material for non-volatile memories and compare three allotropes of carbon, namely carbon nanotubes, graphene-like conductive carbon and insulating carbon for their possible application as resistance-change material in high density non-volatile memories. Repetitive high-speed switching and the potential for multi-level programming have been successfully demonstrated.

Franz Kreupl; Rainer Bruchhaus; Petra Majewski; Jan B. Philipp; Ralf Symanczyk; Thomas Happ; Christian Arndt; Mirko Vogt; Roy Zimmermann; Axel Buerke; Andrew P. Graham; Michael Kund

2008-01-01

132

Randomly oriented carbon/carbon composite  

NASA Astrophysics Data System (ADS)

The main objective of this study is to develop an alternate, rapid and cost effective process for the fabrication of carbon/carbon (C/C) composite. Slurry moulding technique is adopted for the fabrication of C/C composite. Randomly oriented hybrid discrete carbon fiber (CF) reinforced and mesophase pitch (MP) derived matrix C/C composite is fabricated. Process parameters are optimized and repeatability is proved. The electrical conductivity of the composite fabricated through the developed process is found to be better than that fabricated through conventional processes. The other properties are also found to be competent. The randomly oriented C/C composite because of its mouldability is found suitable for various applications which require complex shapes.

Raunija, Thakur Sudesh Kumar; Babu, S.

2013-06-01

133

Method for Making a Carbon-Carbon Cylinder Block  

NASA Technical Reports Server (NTRS)

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.

Ransone, Phillip O. (Inventor)

1997-01-01

134

Interstitially protected oxidation resistant carbon-carbon composite  

Microsoft Academic Search

The carbon fiber bundles in a carbon-carbon composite are protected against oxidation by coating the fiber bundles with at least one protective layer consisting of an underlayer portion of boron carbide and an overlayer portion of silicon carbide.

T. E. Strangman; R. J. Keiser

1984-01-01

135

Cumulative Carbon and Just Allocation of the Global Carbon Commons  

E-print Network

in the atmosphere causes global warming and other forms of climate disruption, while that portion that entersCumulative Carbon and Just Allocation of the Global Carbon Commons R.T. Pierrehumbert* Abstract. Introduction............................................... 528 II. The Global Carbon Commons

Pierrehumbert, Raymond

136

Elevated atmospheric carbon dioxide increases soil carbon  

SciTech Connect

In a study funded by the U.S. Department of Energy's Office of Science, researchers from Argonne and Oak Ridge National Laboratories and Kansas State and Texas A&M Universities evaluated the collective results of earlier studies by using a statistical procedure called meta-analysis. They found that on average elevated CO2 increased soil carbon by 5.6 percent over a two to nine year period. They also measured comparable increases in soil carbon for Tennessee deciduous forest and Kansas grassland after five to eight years of experimental exposure to elevated CO2.

Norby, Richard J [ORNL; Jastrow, Julie D [ORNL; Miller, Michael R [ORNL; Matamala, Roser [Argonne National Laboratory (ANL); Boutton, Thomas W [Texas A& M University; Rice, Charles W [ORNL; Owensby, Clenton E [Kansas State University

2005-01-01

137

Affordable carbon-carbon composite spacecraft radiator demonstration program  

Microsoft Academic Search

Thermal-structural analysis of a hyperspectral imaging instrument for the NASA New Millennium EO-1 spacecraft indicated that a high conductivity carbon-carbon composite radiator plate without heat pipes would perform equivalently to a baseline aluminum honeycomb heatpipe cryoradiator panel. A carbon-carbon radiator plate was designed, fabricated, and tested to demonstrate that high thermal conductive carbon-carbon composites can achieve cost and weight savings

Edward M. Silverman

2000-01-01

138

Seeing the Carbon Cycle  

ERIC Educational Resources Information Center

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,…

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

2006-01-01

139

Lead carbonate scintillator materials  

DOEpatents

Improved radiation detectors containing lead carbonate or basic lead carbonate as the scintillator element are disclosed. Both of these scintillators have been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to other known scintillator materials. The radiation detectors disclosed are favorably suited for use in general purpose detection and in medical uses.

Derenzo, Stephen E. (Pinole, CA); Moses, William W. (Berkeley, CA)

1991-01-01

140

Superplastic carbon nanotubes  

Microsoft Academic Search

The theoretical maximum tensile strain - that is, elongation - of a single-walled carbon nanotube is almost 20%, but in practice only 6% is achieved. Here we show that, at high temperatures, individual single-walled carbon nanotubes can undergo superplastic deformation, becoming nearly 280% longer and 15 times narrower before breaking. This superplastic deformation is the result of the nucleation and

J. Y. Huang; S. Chen; Z. Q. Wang; K. Kempa; Y. M. Wang; S. H. Jo; G. Chen; M. S. Dresselhaus; Z. F. Ren

2006-01-01

141

Plant Carbonic Anhydrases  

PubMed Central

On the basis of polyacrylamide gradient gel electrophoresis of leaf extracts from 24 species of higher plants, two main forms of carbonic anhydrase (EC 4.2.1.1) were recognized; the “dicotyledon” type and the “monocotyledon” type. More than one band of enzyme was found on gels from most species, suggesting the possibility of carbonic anhydrase isoenzymes in higher plants. Images PMID:16658144

Atkins, C. A.; Patterson, B. D.; Graham, D.

1972-01-01

142

The carbon cycle revisited  

NASA Technical Reports Server (NTRS)

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.

Bolin, Bert; Fung, Inez

1992-01-01

143

Carbon Dioxide Removal  

NSDL National Science Digital Library

In this experiment using sprigs of Elodea, learners will observe a natural process that removes carbon dioxide (CO2) from Earth's atmosphere. This process is a part of the carbon cycle and results in temperature suitable for life. Note: this experiment requires that learners make observations an hour or the next day after they set up the materials.

History, American M.

2008-01-01

144

Fly ash carbon passivation  

DOEpatents

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.

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

2013-05-14

145

Extrasolar Carbon Planets  

E-print Network

We suggest that some extrasolar planets silicon carbide and other carbon compounds. Pulsar planets and low-mass white dwarf planets are especially good candidate members of this new class of planets, but these objects could also conceivably form around stars like the Sun. This planet-formation pathway requires only a factor of two local enhancement of the protoplanetary disk's C/O ratio above solar, a condition that pileups of carbonaceous grains may create in ordinary protoplanetary disks. Hot, Neptune-mass carbon planets should show a significant paucity of water vapor in their spectra compared to hot planets with solar abundances. Cooler, less massive carbon planets may show hydrocarbon-rich spectra and tar-covered surfaces. The high sublimation temperatures of diamond, SiC, and other carbon compounds could protect these planets from carbon depletion at high temperatures.

Kuchner, M J; Kuchner, Marc J.

2005-01-01

146

Extrasolar Carbon Planets  

E-print Network

We suggest that some extrasolar planets silicon carbide and other carbon compounds. Pulsar planets and low-mass white dwarf planets are especially good candidate members of this new class of planets, but these objects could also conceivably form around stars like the Sun. This planet-formation pathway requires only a factor of two local enhancement of the protoplanetary disk's C/O ratio above solar, a condition that pileups of carbonaceous grains may create in ordinary protoplanetary disks. Hot, Neptune-mass carbon planets should show a significant paucity of water vapor in their spectra compared to hot planets with solar abundances. Cooler, less massive carbon planets may show hydrocarbon-rich spectra and tar-covered surfaces. The high sublimation temperatures of diamond, SiC, and other carbon compounds could protect these planets from carbon depletion at high temperatures.

Marc J. Kuchner; S. Seager

2005-04-08

147

Carbon Park Environmental Impact Assessment  

E-print Network

of offsetting the University's carbon footprint, promoting biodiversity and establishing easily maintained Carbon Park Environmental Impact Assessment A B.E.S.T. Project By, Adam Bond 2011 #12; Bishop's University Carbon Park

148

Effective and recoverable homogeneous catalysts for the transesterification of dimethyl carbonate with ethanol: Lanthanide triflates  

Microsoft Academic Search

The catalytic activities of metal triflates were tested for the transesterification of dimethyl carbonate (DMC) with ethanol.\\u000a It was found that yttrium triflate was the most efficient homogeneous catalyst. When the transesterification reaction was\\u000a catalyzed by yttrium triflate at 76–80°C, 7 h, ethanol to DMC in 6: 1 molar ratio, 0.35 mol % of catalyst based on DMC, the\\u000a conversion

F. M. Mei; E. X. Chen; G. X. Li

2009-01-01

149

Carbon dioxide disposal in carbonate minerals  

Microsoft Academic Search

We introduce a safe and permanent method of CO2 disposal based on combining CO2 chemically with abundant raw materials to form stable carbonate minerals. Substantial heat is liberated in the overall chemical reaction so that cost will be determined by the simplicity and speed of the reaction rather than the cost of energy. Preliminary investigations have been conducted on two

Klaus S. Lackner; Christopher H. Wendt; Darryl P. Butt; Edward L. Joyce; David H. Sharp

1995-01-01

150

Single-walled carbon nanotube buckypaper and mesophase pitch carbon\\/carbon composites  

Microsoft Academic Search

Carbon\\/carbon composites consisting of single-walled carbon nanotube (SWCNT) buckypaper (BP) and mesophase pitch resin have been produced through impregnation of BP with pitch using toluene as a solvent. Drying, stabilization and carbonization processes were performed sequentially, and repeated to increase the pitch content. Voids in the carbon\\/carbon composite samples decreased with increasing impregnation process cycles. Electrical conductivity and density of

Jin Gyu Park; Nam Gyun Yun; Young Bin Park; Richard Liang; Lloyd Lumata; James S. Brooks; Chuck Zhang; Ben Wang

2010-01-01

151

Electron Beam Exposure of Thermal Control Paints on Carbon-Carbon and Carbon-Polyimide Composites  

Microsoft Academic Search

Carbon-carbon and carbon-polyimide composites are being considered for use as radiator face sheets or fins for space radiator applications. Several traditional white thermal control paints are being considered for the surface of the composite face sheets or fins. One threat to radiator performance is high energy electrons. The durability of the thermal control paints applied to the carbon-carbon and carbon-polyimide

Donald A. Jaworske

2006-01-01

152

Single-walled carbon nanotube buckypaper and mesophase pitch carbon\\/carbon composites  

Microsoft Academic Search

Carbon\\/carbon composites consisting of single-walled carbon nanotube (SWCNT) buckypaper (BP) and mesophase pitch resin have been produced through impregnation of BP with pitch using toluene as a solvent. Drying, stabilization and carbonization processes were performed sequentially, and repeated to increase the pitch content. Voids in the carbon\\/carbon composite samples decreased with increasing impregnation process cycles. Electrical conductivity and density of

Jin Gyu Park; Nam Gyun Yun; Young Bin Park; Richard Liang; Lloyd Lumata; James Brooks; Chuck Zhang; Ben Wang

2011-01-01

153

IMPACCT: Carbon Capture Technology  

SciTech Connect

IMPACCT Project: IMPACCT’s 15 projects seek to develop technologies for existing coal-fired power plants that will lower the cost of carbon capture. Short for “Innovative Materials and Processes for Advanced Carbon Capture Technologies,” the IMPACCT Project is geared toward minimizing the cost of removing carbon dioxide (CO2) from coal-fired power plant exhaust by developing materials and processes that have never before been considered for this application. Retrofitting coal-fired power plants to capture the CO2 they produce would enable greenhouse gas reductions without forcing these plants to close, shifting away from the inexpensive and abundant U.S. coal supply.

None

2012-01-01

154

The Carbon Cycle Game  

NSDL National Science Digital Library

In this activity, learners take on the role of a carbon atom and record which reservoirs in the carbon cycle they visit. Learners will compare and contrast their trip with those of other learners to discover information about sources and sinks, and residence times of the different reservoirs. Ocean processes are highlighted to allow the educator to define the biological pump and explain its importance to climate. Helping learners understand the carbon cycle is essential to their understanding of the causes and consequences of climate change.

Now, Cosee

2012-01-01

155

Improving Carbon Fixation Pathways  

PubMed Central

A recent resurgence in basic and applied research on photosynthesis has been driven in part by recognition that fulfilling future food and energy requirements will necessitate improvements in crop carbon-fixation efficiencies. Photosynthesis in traditional terrestrial crops is being reexamined in light of molecular strategies employed by photosynthetic microbes to enhance the activity of the Calvin cycle. Synthetic biology is well-situated to provide original approaches for compartmentalizing and enhancing photosynthetic reactions in a species independent manner. Furthermore, the elucidation of alternative carbon-fixation routes distinct from the Calvin cycle raises possibilities that alternative pathways and organisms can be utilized to fix atmospheric carbon dioxide into useful materials. PMID:22647231

Ducat, Daniel C.

2012-01-01

156

Carbon Nanotubes in Neuroscience  

PubMed Central

Carbon nanotubes have electrical, mechanical and chemical properties that make them one of the most promising materials for applications in neuroscience. Single-walled and multi-walled carbon nanotubes have been increasingly used as scaffolds for neuronal growth and more recently for neural stem cell growth and differentiation. They are also used in interfaces with neurons, where they can detect neuronal electrical activity and also deliver electrical stimulation to these cells. The emerging picture is that carbon nanotubes do not have obvious adverse effects on mammalian health. Thus in the near future they could be used in brain–machine interfaces. PMID:19812974

Malarkey, Erik B.

2010-01-01

157

Understanding activated carbons  

SciTech Connect

It would be fair to say that most chemical industry professionals can explain the differences between adsorption and absorption. But when asked which type of activated carbon would be best suited for a particular application, few chemists or chemical engineers would be able to identify what properties to look for. Activated carbon is used in a wide variety of applications such as purification or recovery of chemical products, catalysis or catalyst supports, and various environmental applications such as VPC abatement and wastewater purification. With such broad used in industry, it is critical for engineers and chemists to understand the differences between activated carbons in order to obtain the best performance from their processes.

Boppart, S.; Ingle, L.; Potwora, R.J.; Rester, D.O. [NORIT Americas Inc., Atlanta, GA (United States)

1996-09-01

158

Trees and Carbon  

NSDL National Science Digital Library

The transport and transformation of substances in the environment are known collectively as biogeochemical cycles. These global cycles involve the circulation of elements and nutrients that sustain both the biological and physical aspects of the environment. As an example, this discussion centers around the carbon cycle and how carbon is sequestered in trees. Students will perform an activity that replicates a case study in which the biomass of trees in a 15-acre plot of forest was calculated to determine the amount of carbon sequestered per acre.

Pratte, John

159

Resistivity of Carbon-Carbon Composites Halved  

NASA Technical Reports Server (NTRS)

Carbon-carbon composites have become the material of choice for applications requiring strength and stiffness at very high temperatures (above 2000 C). These composites comprise carbon or graphite fibers embedded in a carbonized or graphitized matrix. In some applications, such as shielding sensitive electronics in very high temperature environments, the performance of these materials would be improved by lowering their electrical resistivity. One method to lower the resistivity of the composites is to lower the resistivity of the graphite fibers, and a proven method to accomplish that is intercalation. Intercalation is the insertion of guest atoms or molecules into a host lattice. In this study the host fibers were highly graphitic pitch-based graphite fibers, or vapor-grown carbon fibers (VGCF), and the intercalate was bromine. Intercalation compounds of graphite are generally thought of as being only metastable, but it has been shown that the residual bromine graphite fiber intercalation compound is remarkably stable, resisting decomposition even at temperatures at least as high as 1000 C. The focus of this work was to fabricate composite preforms, determine whether the fibers they were made from were still intercalated with bromine after processing, and determine the effect on composite resistivity. It was not expected that the resistivity would be lowered as dramatically as with graphite polymer composites because the matrix itself would be much more conductive, but it was hoped that the gains would be substantial enough to warrant its use in high-performance applications. In a collaborative effort supporting a Space Act Agreement between the NASA Glenn Research Center and Applied Sciences, Inc. (Cedarville, OH), laminar preforms were fabricated with pristine and bromine-intercalated pitch-based fibers (P100 and P100-Br) and VGCF (Pyro I and Pyro I-Br). The green preforms were carbonized at 1000 C and then heat treated to 3000 C. To determine whether the fibers in the samples were still intercalated after composite fabrication, they were subjected to X-ray diffraction. The composites containing intercalated graphite fibers showed much higher background scatter than that of pristine fibers, indicating the presence of bromine in the samples. More importantly, faint features indicative of intercalation were visible in the diffraction pattern, showing that the fibers were still intercalated.

Gaier, James R.

2004-01-01

160

Carbon dioxide sequestration as stable carbonate minerals - environmental barriers  

Microsoft Academic Search

This paper considers the major environmental impacts associated with industrial-scale carbon dioxide sequestration as stable carbonate minerals, material resulting from a study undertaken by CSMA Consultants Ltd. in 1999. The chemical bonding of carbon dioxide, through reaction of two or more products to produce magnesium or calcium carbonate has been suggested as a means to mitigate CO2 from fossil fuel

H. Haywood; J. Eyre; H. Scholes

2001-01-01

161

Small particle impact damage in carbon-carbon composites  

Microsoft Academic Search

Carbon-carbon composites, an important member of the fast emerging families of advanced material systems, which are making it feasible to achieve large advances in aero gas turbines of the future, are considered. In spite of a combination of outstanding properties, carbon-carbon composites do have serious oxidation problems. Oxidation protection technologies, essentially a barrier coating, become essential. Such coating systems, in

S. Gupta; W. Westphal

1991-01-01

162

Pistons and Cylinders Made of Carbon-Carbon Composite Materials  

NASA Technical Reports Server (NTRS)

An improved reciprocating internal combustion engine has a plurality of engine pistons, which are fabricated from carbon---carbon composite materials, in operative association with an engine cylinder block, or an engine cylinder tube, or an engine cylinder jug, all of which are also fabricated from carbon-carbon composite materials.

Rivers, H. Kevin (Inventor); Ransone, Philip O. (Inventor); Northam, G. Burton (Inventor); Schwind, Francis A. (Inventor)

2000-01-01

163

Pistons and Cylinders Made of Carbon-Carbon Composite Materials  

NASA Technical Reports Server (NTRS)

An improved reciprocating internal combustion engine has a plurality of engine pistons, which are fabricated from carbon-carbon composite materials, in operative association with an engine cylinder block, or an engine cylinder tube, or an engine cylinder jug, all of which are also fabricated from carbon-carbon composite materials.

Rivers, H. Kevin (Inventor); Ransone, Philip O. (Inventor); Northam, G. Burton (Inventor); Schwind, Francis A. (Inventor)

2000-01-01

164

Trading Water for Carbon with Biological Carbon Sequestration  

E-print Network

Trading Water for Carbon with Biological Carbon Sequestration Robert B. Jackson,1 * Esteban G. Farley,1 David C. le Maitre,5 Bruce A. McCarl,6 Brian C. Murray7 Carbon sequestration strategies plantations feature prominently among tools for carbon sequestration (1­8). Plantations typi- cally combine

Nacional de San Luis, Universidad

165

A novel carbon fiber based porous carbon monolith  

SciTech Connect

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.

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

1995-07-01

166

Hypervelocity technology carbon/carbon testing  

NASA Astrophysics Data System (ADS)

The paper describes the procedures used at the Structures Test Laboratory of the Wright Laboratory's Flight Dynamics Directorate to test a carbon/carbon hot structure representing a typical hypersonic gliding body, and presents the results of tests. The forebody was heated to 1371 C over 13 test runs, using radiant quartz lamps; a vertical shear force of 5.34 kN was introduced to the nose at a stabilized temperature of 816 C. Test data were collected using prototype high-temperature strain gages, in-house-designed high-temperature extensometers, conventional strain gages, and thermocouples. Video footage was taken of all test runs. Test runs were successfully completed up to 1371 C with flight typical thermal gradients at heating rates up to 5.56 C/sec. Results showed that, overall, the termal test control systems performed as predicted and that test temperatures and thermal gradients were achieved to within about 5 percent in most cases.

Anselmo, John V.; Kretz, Lawrence O.

167

Transport in Carbon Nanotubes  

NASA Technical Reports Server (NTRS)

This presentation discusses coupling between carbon nanotubes (CNT), simple metals (FEG) and a graphene sheet. The graphene sheet did not couple well with FEG, but the combination of a graphene strip and CNT did couple well with most simple metals.

Datta, S.; Xue, Yong-Qinag; Anantram, M. P.; Saini, Subhash (Technical Monitor)

1999-01-01

168

Carbon nanotubes: Perfect mismatch  

NASA Astrophysics Data System (ADS)

The electronic coupling between two stacked atomic layers is usually weak if their periodicities are incommensurate. Optical absorption experiments have now revealed unexpectedly strong interlayer coupling in incommensurate double-walled carbon nanotubes.

Dos Santos, João Lopes

2014-10-01

169

Carbon sequestration in soils  

SciTech Connect

The purpose of this article is to examine (a) the magnitude of the potential for carbon sequestration in the soil as a means of reducing carbon dioxide (CO{sub 2}) in the atmosphere, (b) some of the measures that might be used to achieve this potential, (c) the methods available for estimating carbon sequestration on a farm or regional level, (d) what is needed to achieve international consensus, and (e) additional information needs. This article is not presented as a definitive document but rather as an overview of where scientific opinion converges and where more work is needed. In addition, it aims to provoke discussion of the measures that can increase soil carbon sequestration and the policies that might be used to implement those measures.

Bruce, J.P. [Soil and Water Conservation Society, Ottawa, Ontario (Canada); Frome, M. [Soil and Water Conservation Society, Washington, DC (United States); Haites, E. [Margaree Consultants, Toronto, Ontario (Canada); Janzen, H. [Agriculture and Agri-Food Canada, Lethbridge, Alberta (Canada); Lal, R. [Ohio State Univ., Columbus, OH (United States). School of Natural Resources; Paustian, K. [Colorado State Univ., Fort Collins, CO (United States). Natural Resource Ecology Lab.

1999-01-01

170

Estimating carbon monoxide exposure  

NASA Technical Reports Server (NTRS)

Method predicts effects of carbon monoxide on astronauts confined in spacecraft cabin atmospheres. Information on need for low toxicity level also applies to confined spaces. Benefits are applicable to industry and public health.

Edgerley, R. H.

1971-01-01

171

Carbon Monoxide Safety  

MedlinePLUS

... media accounts and ask your followers to share. Twitter 150+ people die each yr from consumer product- ... National Institute of Standards and Technology Follow us: Twitter Facebook YouTube More information on carbon monoxide safety ...

172

Ringed-Carbon Compounds  

NSDL National Science Digital Library

In this interactive activity adapted from NOVA, learn about alkaloids and steroids, both examples of compounds with carbon rings. Short videos with interviews,animations, and photographs are featured.

Foundation, Wgbh E.

2007-02-12

173

Carbon monoxide intoxication  

SciTech Connect

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.

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

1993-11-01

174

Carbon and oxygen isotope microanalysis of carbonate.  

PubMed

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

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

2009-08-30

175

Development of carbon-carbon sandwich panels  

NASA Astrophysics Data System (ADS)

The Electrostatic Gravity Gradiometer (EGG) is the main payload of the Gravity field and steady state Ocean Circulation Explorer (GOCE) mission, which has the objectives of producing models of the Earth's gravity field and geoid with high resolution and accuracy. The EGG allows measuring the components of the gravity gradient tensor by means of a set of accelerometers. To meet the outstanding measurement requirements, the EGG structure must provide high dimensional stability under the expected environmental conditions. Carbon-Carbon technology has been selected for the construction of the sandwich panels, which support the accelerometers and their electronics, as well as the thermal control unit. This technology in fact offers good thermo-elastic characteristics, low sensitivity to moisture (only for organic assembly), high panel stiffness-to-mass ratio. Due to the lack of heritage for large-size sandwich structures, a dedicated evaluation and qualification program has been established for the demonstration of the suitability of the sandwich and associated manufacturing processes to the GOCE applications. Following the evaluation of candidate materials and associated bonding techniques, a preferred baseline has been selected that is undergoing qualification testing. A safe two-steps manufacturing process of the sandwich panels has been adopted: C/C face-sheets and honeycomb cores are procured from Hitco Carbon Composites Inc, USA, and their assembly is performed by Alcatel Space through organic bonding, to obtain the final sandwich structure. The results of the evaluation and of the first qualification tests are presented in the paper.

Panin, Fabio; Lutz-Nivet, Martine; Lemaire, Hugues

2003-09-01

176

Carbon Isotope Ratios in Belowground Carbon Cycle Processes  

Microsoft Academic Search

Abstract Analyses of carbon isotope ratios (?,C values of CO2effluxing from soils, but asof,yet a global,database,is lacking,with which,to test this prediction. Such a global,database,would be a useful input for global carbon cycle models,which,rely on ?values,to constrain source and sink relations. Keywords: global change, ecosystem processes, soil organic carbon, carbon isotope ratio, carbon cycle,

James R. Ehleringer; Nina Buchmann; Lawrence B. Flanagan

2000-01-01

177

CARBON -14 PHYSICAL DATA  

E-print Network

) · Committed Effective Dose Equivalent (CEDE): 1.54 mrem/uCi (ingested) · Annual Limit on Intake (ALI)*: 2 mCi (ingestion of labeled organic compound) 2000 mCi (inhalation of carbon monoxide) 200 mCi (inhalation of carbon dioxide) *[1.0 ALI = 2 mCi (ingested C- 14 organic compound) = 5,000 mrem CEDE] · Skin

Vallino, Joseph J.

178

Lead carbonate scintillator materials  

DOEpatents

Improved radiation detectors containing lead carbonate or basic lead carbonate as the scintillator element are disclosed. Both of these scintillators have been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to other known scintillator materials. The radiation detectors disclosed are favorably suited for use in general purpose detection and in medical uses. 3 figures.

Derenzo, S.E.; Moses, W.W.

1991-05-14

179

Carbon Cycle Poster  

NSDL National Science Digital Library

In this activity, learners gain knowledge about how carbon moves through all four of the Earthâs major spheres (biosphere, hydrosphere, atmosphere, and lithosphere), and understand how humans influence the carbon cycle and contribute to global climate change. Learners work in groups to create a diagram to show how the Earth's major spheres are connected by diffusion, respiration, burial, and weathering. This detailed lesson plan includes key vocabulary words, discussion questions, resources for educators, and is standards-based.

Sciences, California A.

2008-01-01

180

GETTING CARBON CAPTURE AND STORAGE  

E-print Network

GETTING CARBON CAPTURE AND STORAGE TECHNOLOGIES TO MARKET BREAKING THE DEADLOCK Report of a Science: Carbon Capture and Storage © OECD/IEA 2009, fig. 1, p. 6 Figures 2 and 3 reprinted with permission from `UK Carbon storage and capture, where is it?' by Stuart Haszeldine, Professor of Carbon Capture

Haszeldine, Stuart

181

Carbon Nanomaterials: The Ideal Interconnect  

E-print Network

-dimensional allotropes of carbon, known as carbon nanomaterials, have extraordinary physical properties becauseCarbon Nanomaterials: The Ideal Interconnect Technology for Next- Generation ICs Hong Li, Chuan Xu-generation ICs. In this research, carbon nanomaterials, with their many attractive properties, are emerging

182

AMAZING CARBON Prof. David Tomnek  

E-print Network

determines function. In this context, carbon is a real champion, with its layered sp2 allotrope being bonded chains. Even though other pure-carbon allotropes, such as C60 with a significantly differentAMAZING CARBON Prof. David Tománek Carbon does not stop amazing us ­ again and again. For many

183

Molten carbonate fuel cell cathode with mixed oxide coating  

DOEpatents

A molten carbonate fuel cell cathode having a cathode body and a coating of a mixed oxygen ion conductor materials. The mixed oxygen ion conductor materials are formed from ceria or doped ceria, such as gadolinium doped ceria or yttrium doped ceria. The coating is deposited on the cathode body using a sol-gel process, which utilizes as precursors organometallic compounds, organic and inorganic salts, hydroxides or alkoxides and which uses as the solvent water, organic solvent or a mixture of same.

Hilmi, Abdelkader; Yuh, Chao-Yi

2013-05-07

184

Mitochondrial carbonic anhydrase.  

PubMed Central

We have assayed carbonic anhydrase activity (carbonate dehydratase, carbonate hydro-lyase, EC 4.2.1.1) and bicarbonate permeability in suspensions of broken and intact guinea pig mitochondria by monitoring the disappearance of C16O18O. We found significant activity in preparations from liver and skeletal muscle, but not in preparations from heart muscle, brain, and kidney. Intact mitochondria containing carbonic anhydrase produce a two-phase acceleration of the disappearance of the labeled CO2, which indicates that the enzyme is located in a region more accessible to CO2 than to HCO3-. Acetazolamide inhibits the enzyme activity instantly in broken mitochondria but only after a delay in intact mitochondria, indicating that the enzyme is in a region not immediately accessible to the inhibitor. Sonication of mitochondria containing carbonic anhydrase activity releases the enzyme, which remains in the supernatant after sedimentation of the submitochondrial particles. This shows that mitochondrial carbonic anhydrase is in the matrix compartment and not in, or bound to, the inner membrane. The activity of the enzyme increases markedly with increasing pH. The enzyme activity of intact mitochondria is greater than that of the broken mitochondria at the same pH of the suspending fluid, corresponding to an intramitochondrial pH that is 0.2-0.5 unit more alkaline. PMID:6776540

Dodgson, S J; Forster, R E; Storey, B T; Mela, L

1980-01-01

185

Carbon Characterization Laboratory Report  

SciTech Connect

The newly completed Idaho National Laboratory (INL) Carbon Characterization Laboratory (CCL) is located in Lab-C20 of the Idaho National Laboratory Research Center. This laboratory was established under the Next Generation Nuclear Plant (NGNP) Project to support graphite research and development activities. The CCL is designed to characterize and test carbon-based materials such as graphite, carbon-carbon composites, and silicon-carbide composite materials. The laboratory is fully prepared to measure material properties for nonirradiated carbon-based materials. Plans to establish the laboratory as a radiological facility within the next year are definitive. This laboratory will be modified to accommodate irradiated materials, after which it can be used to perform material property measurements on both irradiated and nonirradiated carbon-based material. Instruments, fixtures, and methods are in place for preirradiation measurements of bulk density, thermal diffusivity, coefficient of thermal expansion, elastic modulus, Young’s modulus, Shear modulus, Poisson ratio, and electrical resistivity. The measurement protocol consists of functional validation, calibration, and automated data acquisition.

David Swank; William Windes; D.C. Haggard; David Rohrbaugh; Karen Moore

2009-03-01

186

Method of manufacturing carbon nanotubes  

NASA Technical Reports Server (NTRS)

A process for manufacturing carbon nanotubes, including a step of inducing electrical current through a carbon anode and a carbon cathode under conditions effective to produce the carbon nanotubes, wherein the carbon cathode is larger than the carbon anode. Preferably, a welder is used to induce the electrical current via an arc welding process. Preferably, an exhaust hood is placed on the anode, and the process does not require a closed or pressurized chamber. The process provides high-quality, single-walled carbon nanotubes, while eliminating the need for a metal catalyst.

Benavides, Jeanette M. (Inventor); Leidecker, Henning W. (Inventor); Frazier, Jeffrey (Inventor)

2004-01-01

187

Ocean Sciences: Carbonate Network Forms  

Microsoft Academic Search

The Carbonate Network is a new Internet-based international network (www.carbonet.net) for carbonate researchers. The network aims to stimulate an increased exchange of knowledge between carbonate researchers from different geological institutions, and to provide a scientific forum for discussing carbonate-related issues. The discussion forum (www.carbonet.net\\/forum), which is the essence of the Carbonate Network, includes information about meetings, publications, excursions, courses, Internet

Bjarne Rafaelsen

2004-01-01

188

Studies and characterisations of various activated carbons used for carbon\\/carbon supercapacitors  

Microsoft Academic Search

Various activated carbons from the PICA Company have been tested in supercapacitor cells in order to compare their performances. The differences measured in terms of specific capacitance and cell resistance are presented. Porosity measurements made on activated carbon powders and electrode allowed a better understanding of the electrochemical behaviour of these activated carbons. In this way, the PICACTIF SC carbon

J Gamby; P. L Taberna; P Simon; J. F Fauvarque; M Chesneau

2001-01-01

189

Measurement of carbon capture efficiency and stored carbon leakage  

DOEpatents

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.

Keeling, Ralph F.; Dubey, Manvendra K.

2013-01-29

190

Microbially mediated carbon mineralization: Geoengineering a carbon-neutral mine  

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

191

Effect of carbon nanotube addition on the tribological behavior of carbon\\/carbon composites  

Microsoft Academic Search

Carbon nanotube composite coatings were applied onto carbon\\/carbon composites to improve wear properties. Carbon nanotubes have been prepared by catalytic pyrolysis of hydrocarbons. The nanotube slurry was prepared by addition of phenolic resin and solvent to infiltrate into C\\/C composites. The nanotube added composites were then carbonized in a nitrogen atmosphere. Ball-on-disc type wear tests were performed to evaluate the

Dae-Soon Lim; Jeong-Wook An; Hwack Joo Lee

2002-01-01

192

Effects of Preform and Pyrolytic Carbon Structure on Thermophysical Properties of 2D Carbon\\/Carbon Composites  

Microsoft Academic Search

Four kinds of carbon\\/carbon (C\\/C) composites, including the needled carbon fiber felt\\/the pyrolytic carbon (two different pyrolytic carbon microstructures), the chopped carbon fiber\\/the resin + pyrolytic carbon (PyrC), and the carbon cloth\\/PyrC, named as the composites 1#, 4#, 2#, and 3#, are prepared respectively. Effects of the preform and pyrolytic carbon structure on the thermophysical properties of 2D C\\/C composites

Rui-ying LUO; Yong-hong CHENG

2004-01-01

193

Carbon-based sorbents: carbon nanotubes.  

PubMed

Carbon nanotubes (CNTs), as an advanced material, have been widely used in various fields since its discovery in 1991. In recent years, as an excellent adsorption material, the pure and modified CNTs are successfully used for the purification and enrichment of food, medicine, environmental samples and so on. In this review, we focus on the detailed description of different CNTs-based extraction modes such as solid-phase extraction (SPE) (including cartridge and disk SPE, dispersive SPE, and ?-SPE) and solid-phase microextraction (SPME) (including fiber SPME, electrosorption-enhanced SPME, stir bar sorptive extraction, needle trap SPME, and hollow fiber SPME). PMID:24792692

Liang, Xiaojing; Liu, Shujuan; Wang, Shuai; Guo, Yong; Jiang, Shengxiang

2014-08-29

194

Functionalization of carbon nanotubes  

NASA Astrophysics Data System (ADS)

Carbon nanotubes have unique properties that make them attractive for different engineering applications. However, because of their chemical inertness, carbon nanotubes have to be functionalized in order to acquire additional physico-chemical properties. Large multiwalled carbon nanotubes are different from fullerenes and singlewalled nanotubes because the stresses in their walls are almost relaxed while most chemical methods for fullerene functionalization exploit this effect of stressed bonds. The objective of this work is to develop new methods for functionalization of multiwalled carbon nanotubes. This work is dedicated to study two functionalization methods. The first deals with physico-chemical functionalization by filling the nanotube interior with colloidal suspensions. Irreversible adsorption of functional nanoparticles on the nanotube wall leads to the nanotube functionalization. The second method is purely chemical functionalization, which uses the reaction of cyclopropanation to break pi-bonds in the benzene rings of the nanotubes with formation of new ?-bonds with deprotonated malonate. This so-called Bingel reaction has been used in fullerene chemistry and in this work was applied for the first time to functionalize multiwalled carbon nanotubes. While capillary filling of carbon nanotubes was known long ago, the research community was skeptical about possibility of engulfing nanoparticles into nanotubes by capillary forces. We developed and implemented capillary method to fill nanotubes with different nanoparticles. Using this method, magnetic carbon nanotubes were produced for the first time. Synthesized nanotubes have very high magnetic moment and allow to manipulate them by magnetic field. These magnetic nanotubes have been successfully used in fabrication of carbon nanotube-tipped pipettes for biological probes. The Bingel reaction was studied on three sets of multiwalled carbon nanotubes with diameters: 20nm, 100nm, and 300nm. To estimate the degree of Bingel functionalization, the chemical tagging of gold nanoparticles to the malonated nanotubes was used. Gold was attached using the sulfur-gold bridges formed after the reaction of transesterification of malonated tubes with 2(methylthio)ethanol. We found that the critical size for Bingel reaction to occur along the whole nanotube wall is less than 200 nm. Larger nanotubes could be also Bingel modified, but their chemical activity is mostly observed at the nanotube ends.

Korneva, Guzeliya

195

Response of carbon-carbon composites to challenging environments  

NASA Technical Reports Server (NTRS)

This paper presents results from material performance evaluations of oxidation-resistant carbon-carbon composites intended for multiuse aerospace applications, which cover the effects of the following environmental parameters: the oxidizing nature of the environments (including both high and low oxygen partial pressures), high temperatures, moisture, cyclic temperature service, and foreign-object impact. Results are presented for the carbon-carbon material currently in use as the thermal-protection-system material on Space Shuttle, as well as for newer and more advanced structural forms of carbon-carbon composites.

Maahs, Howard G.; Ohlhorst, Craig W.; Barrett, David M.; Ransone, Philip O.; Sawyer, J. Wayne

1988-01-01

196

Carbon fuel particles used in direct carbon conversion fuel cells  

DOEpatents

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.

Cooper, John F. (Oakland, CA); Cherepy, Nerine (Oakland, CA)

2012-01-24

197

Carbon fuel particles used in direct carbon conversion fuel cells  

DOEpatents

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.

Cooper, John F.; Cherepy, Nerine

2012-10-09

198

Carbon fuel particles used in direct carbon conversion fuel cells  

DOEpatents

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.

Cooper, John F. (Oakland, CA); Cherepy, Nerine (Oakland, CA)

2011-08-16

199

Chemically modified carbonic anhydrases useful in carbon capture systems  

DOEpatents

The present disclosure relates to chemically modified carbonic anhydrase polypeptides and soluble compositions, homogenous liquid formulations comprising them. The chemically modified carbonic anhydrase polypeptides have improved properties relative to the same carbonic anhydrase polypeptide that is not chemically modified including the improved properties of increased activity and/or stability in the presence of amine compounds, ammonia, or carbonate ion. The present disclosure also provides methods of preparing the chemically modified polypeptides and methods of using the chemically modified polypeptides for accelerating the absorption of carbon dioxide from a gas stream into a solution as well as for the release of the absorbed carbon dioxide for further treatment and/or sequestering.

Novick, Scott; Alvizo, Oscar

2013-01-15

200

Carbon Fuel Particles Used in Direct Carbon Conversion Fuel Cells  

DOEpatents

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.

Cooper, John F. (Oakland, CA); Cherepy, Nerine (Oakland, CA)

2008-10-21

201

CarbonTracker  

NSDL National Science Digital Library

This portal provides information about the National Oceanic and Atmospheric Administration (NOAA) Earth System Research Laboratory (ERSL) CarbonTracker, a system to keep track of carbon dioxide uptake and release at the Earth's surface over time. CarbonTracker produces model predictions of atmospheric CO2 mole fractions, to be compared with the observed atmospheric CO2 mole fractions. Materials available at the site include CO2 flux maps, flux time series graphs, carbon 'weather' maps, and CO2 concentration time series graphs. A download (FTP) page provides access to datasets on 3-D CO2 mole fractions, weekly fluxes, atmospheric CO2 observations, and to the CarbonTracker source code. There is also a link to the Interactive Atmospheric Data Visualization (IADV) tool, a data explorarion tool that enables users to view all data including near real-time preliminary measurement results, obtain details about each sampling location, manipulate and compare NOAA ESRL datasets, create custom graphs, and view their plots online or save them for later use. Other materials include subscription information for an email list, a glossary, and a bibliography.

202

Orbiting Carbon Observatory  

NASA Technical Reports Server (NTRS)

Human impact on the environment has produced measurable changes in the geological record since the late 1700s. Anthropogenic emissions of CO2 today may cause the global climate to depart for its natural behavior for many millenia. CO2 is the primary anthropogenic driver of climate change. The Orbiting Carbon Observatory goals are to help collect measurements of atmospheric CO2, answering questions such as why the atmospheric CO2 buildup varies annually, the roles of the oceans and land ecosystems in absorbing CO2, the roles of North American and Eurasian sinks and how these carbon sinks respond to climate change. The present carbon cycle, CO2 variability, and climate uncertainties due atmospheric CO2 uncertainties are highlighted in this presentation.

Miller, Charles E.

2005-01-01

203

Carbon Nanotubes for Supercapacitor  

PubMed Central

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. PMID:20672061

2010-01-01

204

Pyrolyzed carbon film diodes.  

PubMed

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

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

2013-11-13

205

Solid State Carbon Monoxide Sensor  

NASA Technical Reports Server (NTRS)

A means for detecting carbon monoxide which utilizes an un-heated catalytic material to oxidize carbon monoxide at ambient temperatures. Because this reaction is exothermic, a thermistor in contact with the catalytic material is used as a sensing element to detect the heat evolved as carbon monoxide is oxidized to carbon dioxide at the catalyst surface, without any heaters or external heating elements for the ambient air or catalytic element material. Upon comparison to a reference thermistor, relative increases in the temperature of the sensing thermistor correspond positively with an increased concentration of carbon monoxide in the ambient medium and are thus used as an indicator of the presence of carbon monoxide.

Upchurch, Billy T. (Inventor); Wood, George M. (Inventor); Schryer, David R. (Inventor); Leighty, Bradley D. (Inventor); Oglesby, Donald M. (Inventor); Kielin, Erik J. (Inventor); Brown, Kenneth G. (Inventor); DAmbrosia, Christine M. (Inventor)

1999-01-01

206

Carbon Cycle and Life  

NSDL National Science Digital Library

In this lesson, learners explore the steps in the carbon cycle and draw conclusions about the importance of the carbon cycle in the planetary temperature system. The lesson models scientific inquiry using the 5E instructional model and includes teacher notes, prerequisite concepts, common misconceptions, student journal and reading. This is lesson six in the Astro-Venture Geology Training Unit that was developed to increase students' awareness of and interest in astrobiology and the many career opportunities that utilize science, math and technology skills. The lessons are designed for educators to use with the Astro-Venture multimedia modules.

207

Carbon Monoxide Detector  

NASA Technical Reports Server (NTRS)

Beckman Instruments, Inc. has introduced another technical approach to pollution detection which was used aboard Skylab. This technique, developed with Ames assistance is known as nondispersive infrared spectroscopy. Previous nondispersive analyzers could not selectively distinguish between water vapor and carbon monoxide, thus necessitating water removal by another device before measurement. These analyzers also were susceptible to vibrations and other problems. New instrument which stimulates fluorescent in two carbon monoxide isotopes in two sealed cells, eliminates these problems and increases sensitivity to a tenth of a part per million.

1976-01-01

208

Ultrahard carbon nanocomposite films  

SciTech Connect

Modest thermal annealing to 600 C of diamondlike amorphous-carbon (a-C) films grown at room temperature results in the formation of carbon nanocomposites with hardness similar to diamond. These nanocomposite films consist of nanometer-sized regions of high density a-C embedded in an a-C matrix with a reduced density of 5--10%. The authors report on the evolution of density and bonding topologies as a function of annealing temperature. Despite a decrease in density, film hardness actually increases {approximately} 15% due to the development of the nanocomposite structure.

SIEGAL,MICHAEL P.; TALLANT,DAVID R.; PROVENCIO,PAULA P.; OVERMYER,DONALD L.; SIMPSON,REGINA L.; MARTINEZ-MIRANDA,L.J.

2000-01-27

209

Carbon wastewater treatment process  

NASA Technical Reports Server (NTRS)

A new powdered-carbon treatment process is being developed for the elimination of the present problems, associated with the disposal of biologically active sewage waste solids, and with water reuse. This counter-current flow process produces an activated carbon, which is obtained from the pyrolysis of the sewage solids, and utilizes this material to remove the adulterating materials from the water. Additional advantages of the process are the elimination of odors, the removal of heavy metals, and the potential for energy conservation.

Humphrey, M. F.; Simmons, G. M.; Dowler, W. L.

1974-01-01

210

Carbon Capture and Storage  

SciTech Connect

Carbon capture and sequestration (CCS) is the long-term isolation of carbon dioxide from the atmosphere through physical, chemical, biological, or engineered processes. This includes a range of approaches including soil carbon sequestration (e.g., through no-till farming), terrestrial biomass sequestration (e.g., through planting forests), direct ocean injection of CO{sub 2} either onto the deep seafloor or into the intermediate depths, injection into deep geological formations, or even direct conversion of CO{sub 2} to carbonate minerals. Some of these approaches are considered geoengineering (see the appropriate chapter herein). All are considered in the 2005 special report by the Intergovernmental Panel on Climate Change (IPCC 2005). Of the range of options available, geological carbon sequestration (GCS) appears to be the most actionable and economic option for major greenhouse gas reduction in the next 10-30 years. The basis for this interest includes several factors: (1) The potential capacities are large based on initial estimates. Formal estimates for global storage potential vary substantially, but are likely to be between 800 and 3300 Gt of C (3000 and 10,000 Gt of CO{sub 2}), with significant capacity located reasonably near large point sources of the CO{sub 2}. (2) GCS can begin operations with demonstrated technology. Carbon dioxide has been separated from large point sources for nearly 100 years, and has been injected underground for over 30 years (below). (3) Testing of GCS at intermediate scale is feasible. In the US, Canada, and many industrial countries, large CO{sub 2} sources like power plants and refineries lie near prospective storage sites. These plants could be retrofit today and injection begun (while bearing in mind scientific uncertainties and unknowns). Indeed, some have, and three projects described here provide a great deal of information on the operational needs and field implementation of CCS. Part of this interest comes from several key documents written in the last three years that provide information on the status, economics, technology, and impact of CCS. These are cited throughout this text and identified as key references at the end of this manuscript. When coupled with improvements in energy efficiency, renewable energy supplies, and nuclear power, CCS help dramatically reduce current and future emissions (US CCTP 2005, MIT 2007). If CCS is not available as a carbon management option, it will be much more difficult and much more expensive to stabilize atmospheric CO{sub 2} emissions. Recent estimates put the cost of carbon abatement without CCS to be 30-80% higher that if CCS were to be available (Edmonds et al. 2004).

Friedmann, S

2007-10-03

211

Heteronuclear carbon nanotubes  

NASA Astrophysics Data System (ADS)

The physical properties of double-wall carbon nanotubes (DWCNT) with highly 13C enriched inner walls were studied with Raman spectroscopy and nuclear magnetic resonance (NMR). An inhomogeneous broadening of the vibrational modes is explained by the random distribution of 12C and 13C nuclei based on ab-initio calculations. The growth of DWCNTs from natural and 13C enriched fullerene mixtures indicates that carbon does not diffuse freely along the tube axis during the inner tube growth. The high curvature of the small diameter inner tubes manifests in an increased distribution of the NMR chemical shift tensor components.

Simon, Ferenc; Pfeiffer, Rudolf; Kramberger, Christian; Kuzmany, Hans; Zólyomi, Viktor; Kürti, Jen?; Singer, Philip M.; Alloul, Henri

2005-09-01

212

Structural response of oxidation resistant carbon-carbon composites  

E-print Network

, and unit cell methodology to determine the constitutive response of the carbon-carbon laminate with the inhibitors. These analytical models are used to study the effects of progressive failure, material defects, and oxidation on this material system...

Ashley, Timothy Harold

2012-06-07

213

Carbon dioxide sequestration as stable carbonate minerals - environmental barriers  

NASA Astrophysics Data System (ADS)

This paper considers the major environmental impacts associated with industrial-scale carbon dioxide sequestration as stable carbonate minerals, material resulting from a study undertaken by CSMA Consultants Ltd. in 1999. The chemical bonding of carbon dioxide, through reaction of two or more products to produce magnesium or calcium carbonate has been suggested as a means to mitigate CO2 from fossil fuel power plants. The study considered six potential methods for sequestering carbon dioxide, notionally captured from fossil fuel burning power stations, as stable mineral carbonates, i.e. magnesite and limestone (calcium carbonate) and as sodium bicarbonate. Four methods were eliminated in the initial screening and two were selected for further detailed consideration. Following this stage the overall environmental costs, including environmental impacts, energy and carbon dioxide balances, meant that all the current technologies amenable to reasoned consideration had to be discarded as currently environmentally unacceptable.

Haywood, H.; Eyre, J.; Scholes, H.

2001-11-01

214

Carbon Cycle: Exchanging Carbon Dioxide between the Atmosphere and Ocean  

NSDL National Science Digital Library

This lab investigates the exchange of carbon dioxide between the atmosphere and the ocean's surface. It is based on the fact that carbon dioxide dissolves in the ocean and provides the source of that plants and plankton living in the ocean rely on for photosynthesis. Students will discover that the amount of carbon dioxide the ocean can contain depends on the temperature of the water and its salinity (whether it is sea water or fresh water) and that cold water can hold more carbon dioxide in solution than warm water. They will observe that when carbon dioxide dissolves in water, it forms carbonic acid which makes the water acidic, and they will test for the acidity caused by the presence of dissolved carbon dioxide using Universal Indicator, which turns yellow when the solution is acidic. This activity tests whether sea water or fresh water absorbs more carbon dioxide.

215

Carbon cycle: A dent in carbon's gold standard  

Microsoft Academic Search

The global uptake of carbon by land plants may be greater than previously thought, according to observations based on the enigmatic Keeling curve of rising atmospheric carbon dioxide. See Letter p.579

Matthias Cuntz

2011-01-01

216

Development of carbon-carbon composites from solvent extracted pitch  

SciTech Connect

There are several methods used to fabricate carbon-carbon composites. One used extensively in the fabrication of aerospace components such as rocket nozzles and reentry vehicle nosetips, as well as commercial components for furnace fixturing and glass manufacturing, is the densification of a woven preform with molten pitch, and the subsequent conversion of the pitch to graphite through heat treatment. Two types of pitch are used in this process; coal tar pitch and petroleum pitch. The objective of this program was to determine if a pitch produced by the direct extraction of coal could be used as a substitute for these pitches in the fabrication of carbon-carbon composites. The program involved comparing solvent extracted pitch with currently accepted pitches and rigidizing a carbon-carbon preform with solvent extracted pitch for comparison with carbon-carbon fabricated with currently available pitch.

NONE

1996-06-24

217

Carbon tips for all-carbon single-molecule electronics  

NASA Astrophysics Data System (ADS)

We present here an exhaustive ab initio study of the use of carbon-based tips as electrodes in single-molecule junctions. Motivated by recent experiments, we show that carbon tips can be combined with other carbon nanostructures, such as graphene, to form all-carbon molecular junctions with molecules like benzene or C60. Our results show that the use of carbon tips can lead to relatively conductive molecular junctions. However, contrary to junctions formed with standard metals, the conductance traces recorded during the formation of the all-carbon single-molecule junctions do not exhibit clear conductance plateaus, which can be attributed to the inability of the hydrogenated carbon tips to form chemical bonds with the organic molecules. Additionally, we explore here the use of carbon tips for scanning tunneling microscopy and show that they are well suited for obtaining sample images with atomic resolution.

Dappe, Y. J.; González, C.; Cuevas, J. C.

2014-05-01

218

The thermal properties of carbon-carbon composite materials  

Microsoft Academic Search

An analysis is presented of experimental data on the heat capacity, thermal conductivity, diffusivity, and thermal coefficient of linear expansion of carbon-carbon composites in the temperature range from 300 to 3000 K.

D. P. Volkov; P. Yu. Zarichnyak

1995-01-01

219

Carbon\\/Carbon Composite Bipolar Plate for PEM Fuel Cells  

Microsoft Academic Search

Carbon\\/carbon-composite bipolar plates for proton- exchange-membrane fuel cells have been fabricated by slurry molding a chopped -fiber preform followed by sealing with chemically vapor-infiltrated carbon. The resulting component is hermetic with respect to through- thickness leakage, has a high electronic conductivity as a result of the deposited graphitic carbon, a low density due to retained porosity, and is corrosion resistant.

Theodore M. Besmann; James W. Klett; John J. Henry; Edgar Lara-Curzio

2000-01-01

220

Properties of carbon-carbon composites based on exfoliated graphite  

Microsoft Academic Search

We report the first study of the mechanical and electrical properties of carbon-carbon composites based on flexible graphite\\u000a foils modified with pyrolytic carbon. Our results demonstrate that slight densification with pyrolytic carbon enhances the\\u000a chemical and thermal stability of the graphite foils, increases their Young’s modulus by a factor of 2.5, and reduces their\\u000a resistivity by 25%. Decomposition of the

D. V. Savchenko; S. G. Ionov; A. I. Sizov

2010-01-01

221

Carbon cycling: Molecular regulation of photosynthetic carbon fixation  

Microsoft Academic Search

Photosynthetic carbon fixation by phytoplankton is a key component of the global carbon cycle. Our understanding of the types of picoplankton and ultraphytoplankton involved in this process is evolving. However, mechanisms of regulation of photosynthetic carbon fixation in the oceans are poorly understood. All phytoplankton fix CO2 by reductive carboxylation employing the enzyme ribulose bisphosphate carboxylase (RuBPCase). The sequence of

J. H. Paul

1996-01-01

222

Method of Manufacturing Carbon Fiber Reinforced Carbon Composite Valves  

NASA Technical Reports Server (NTRS)

A method for forming a carbon composite valve for internal combustion engines is discussed. The process includes the steps of braiding carbon fiber into a rope thereby forming a cylindrically shaped valve stem portion and continuing to braid said fiber while introducing into the braiding carbon fiber rope a carbon matrix plug having an outer surface in a net shape of a valve head thereby forming a valve head portion. The said carbon matrix plug acting as a mandrel over which said carbon fiber rope is braided, said carbon fiber rope and carbon matrix plug forming a valve head portion suitable for mating with a valve seat; cutting said braided carbon valve stem portion at one end to form a valve tip and cutting said braided carbon fiber after said valve head portion to form a valve face and thus provide a composite valve preform; and densifying said preform by embedding the braided carbon in a matrix of carbon to convert said valve stem portion to a valve stem and said valve head portion to a valve head thereby providing said composite valve.

Rivers, H. Kevin (Inventor); Ransone, Philip O. (Inventor); Northam, G. Burton (Inventor)

1998-01-01

223

Carbon accounting and carbon footprint – more than just diced results?  

Microsoft Academic Search

Purpose – The purpose of this paper is to discuss the growing public interest in climate protection and the desire for climate-friendly consumption which has led to a previously unimagined demand for Carbon Labels on products and various approaches to calculating the carbon footprint of firms or individual products. Design\\/methodology\\/approach – A principal problem in calculating the carbon footprint is

Mario Schmidt

2009-01-01

224

Carbon-carbon composites : oxidation behavior and coatings protection  

Microsoft Academic Search

Based on their good mechanical performances, potential uses of structural carbon materials have been identified in high temperature applications. Many applications require extended periods ranging from a few hours (at high temperature) to a few thousands of hours (at low temperature) in oxidizing environments where unprotected carbon- carbon composites deteriorate rapidly. Therefore numerous investigations have been conducted in an attempt

M. P. BACOS

1993-01-01

225

Determination of carbonate carbon in geological materials by coulometric titration  

USGS Publications Warehouse

A coulometric titration is used for the determination of carbonate carbon in geological materials. Carbon dioxide is evolved from the sample by the addition of 2 M perchloric acid, with heating, and is determined by automated coulometric titration. The coulometric titration showed improved speed and precision with comparable accuracy to gravimetric and gasometric techniques. ?? 1985.

Engleman, E.E.; Jackson, L.L.; Norton, D.R.

1985-01-01

226

International Conference on Carbon Nanotechnology: Potential and Challenges (Carbon 10)  

E-print Network

such as diamond, amorphous carbon, graphite, carbon-carbon composites, etc. To ensure the highest standards, all, thermal/electrical conductivity, ballistic quantum conductance, and surface functionality. No wonder CNT research has led to a variety of applications, ranging from strong composites, to flat panel displays

Srivastava, Kumar Vaibhav

227

From Coffee to Carbon  

NSDL National Science Digital Library

In this activity, learners place cards featuring biological structures in order by their relative size from largest to smallest. The cards feature structures ranging from the carbon atom (340 pm) to a skin cell (30 μm) to a coffee bean (8 mm). This activity can also be used as a formative assessment or an anticipatory set.

Malone, Molly; Avery, Sheila; Conley, Thomas; Starr, Harmony

2008-01-01

228

Carbon cloth supported electrode  

DOEpatents

A flow-by anode is disclosed made by preparing a liquid suspension of about to about 18% by weight solids, the solids comprising about 3.5 to about 8% of a powdered catalyst of platinum, palladium, palladium oxide, or mixtures thereof; about 60 to about 76% carbon powder (support) having a particle size less than about 20 m.mu.m and about 20 to about 33% of an inert binder having a particle size of less than about 500 m.mu.m. A sufficient amount of the suspension is poured over a carbon cloth to form a layer of solids about 0.01 to about 0.05 cm thick on the carbon cloth when the electrode is completed. A vacuum was applied to the opposite side of the carbon cloth to remove the liquid and the catalyst layer/cloth assembly is dried and compressed at about 10 to about 50 MPa's. The binder is then sintered in an inert atmosphere to complete the electrode. The electrode is used for the oxidation of sulfur dioxide in a sulfur based hybrid cycle for the decomposition of water.

Lu, Wen-Tong P. (Upper St. Clair, PA); Ammon, Robert L. (Baldwin both of, PA)

1982-01-01

229

Carbon smackdown: wind warriors  

SciTech Connect

July 16. 2010 carbon smackdown summer lecture: learn how Berkeley Lab scientists are developing wind turbines to be used in an urban setting, as well as analyzing what it will take to increase the adoption of wind energy in the U.S.

Glen Dahlbacka of the Accelerator & Fusion Research Division and Ryan Wiser of the Environmental Energy Technologies Division are the speakers.

2010-07-21

230

Atmospheric Carbon Dioxide  

NSDL National Science Digital Library

This figure, the famous Keeling Curve, shows the history of atmospheric carbon dioxide concentrations as directly measured at Mauna Loa, Hawaii. This curve is an essential piece of evidence that shows the increased greenhouse gases that cause recent increases in global temperatures.

Rohde, Robert A.; (from published NOAA data)

231

AUSTRALIA'S CARBON FOOTPRINT  

Microsoft Academic Search

This paper gives an overview of the construction techniques and methods used to assign greenhouse gas accounts to industry sectors and of the use of input–output analysis to subsequently calculate the carbon footprint of Australia. The work is motivated by the introduction of an emissions-trading scheme in Australia, and by the need for policy to be developed around the direct

Richard Wood; Christopher J. Dey

2009-01-01

232

Bench Remarks: Carbon Dioxide.  

ERIC Educational Resources Information Center

Discusses the properties of carbon dioxide in its solid "dry ice" stage. Suggests several demonstrations and experiments that use dry ice to illustrate Avogadro's Law, Boyle's Law, Kinetic-Molecular Theory, and the effects of dry ice in basic solution, in limewater, and in acetone. (TW)

Bent, Henry A.

1987-01-01

233

Fabrication of Carbon Nanotubes  

Microsoft Academic Search

The remarkable properties of carbon nanotubes give promise of a diverse array of revolutionary technologies and applications. Synthesis remains the key to their development. This article will review many of the current methods used for nanotube synthesis and the recent results towards achieving the goal of large-scale production with rational control of nanotube structure and properties.

Christopher T. Kingston; Benoit Simard

2003-01-01

234

Granular activated carbon installations  

Microsoft Academic Search

This article presents a compilation and summary of design criteria, performance, and cost data from 22 operating municipal and industrial granular activated carbon (GAC) installations that treat water and wastewater or process food and beverage products. Guidance for using this information to estimate costs for GAC treatment of water supplies is provided. In conjunction with previous reports, this article may

Russell L. Culp; Robert M. Clark

1983-01-01

235

Carbon smackdown: wind warriors  

ScienceCinema

July 16. 2010 carbon smackdown summer lecture: learn how Berkeley Lab scientists are developing wind turbines to be used in an urban setting, as well as analyzing what it will take to increase the adoption of wind energy in the U.S.

Glen Dahlbacka of the Accelerator & Fusion Research Division and Ryan Wiser of the Environmental Energy Technologies Division are the speakers.

2010-09-01

236

Polyimide/carbon Nanocomposites  

NASA Technical Reports Server (NTRS)

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

Harris, Frank W.

2003-01-01

237

Carbon nanotube solar cells.  

PubMed

We present proof-of-concept all-carbon solar cells. They are made of a photoactive side of predominantly semiconducting nanotubes for photoconversion and a counter electrode made of a natural mixture of carbon nanotubes or graphite, connected by a liquid electrolyte through a redox reaction. The cells do not require rare source materials such as In or Pt, nor high-grade semiconductor processing equipment, do not rely on dye for photoconversion and therefore do not bleach, and are easy to fabricate using a spray-paint technique. We observe that cells with a lower concentration of carbon nanotubes on the active semiconducting electrode perform better than cells with a higher concentration of nanotubes. This effect is contrary to the expectation that a larger number of nanotubes would lead to more photoconversion and therefore more power generation. We attribute this to the presence of metallic nanotubes that provide a short for photo-excited electrons, bypassing the load. We demonstrate optimization strategies that improve cell efficiency by orders of magnitude. Once it is possible to make semiconducting-only carbon nanotube films, that may provide the greatest efficiency improvement. PMID:22655070

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

2012-01-01

238

Carbon smackdown: smart windows  

ScienceCinema

August 3, 2010 Berkeley Lab talk: In the fourth of five Carbon Smackdown matches, Berkeley Lab researchers Delia Milliron of the Materials Sciences Division and Stephen Selkowitz of the Environmental Energy Technologies Division talk about their work on energy-saving smart windows.

Delia Milliron

2010-09-01

239

Accidental carbon monoxide poisoning  

Microsoft Academic Search

Improved home insulation and increased use of space heaters have increased the potential for accidental carbon monoxide (CO) poisonings in the home. CO is a major environmental pollutant in today's society and is also contained in cigarette smoke. The toxic effects, metabolic pathways, and treatment of CO poisoning are described.

D. L. Jackson; H. Menges

1980-01-01

240

GRANULAR ACTIVATED CARBON INSTALLATIONS  

EPA Science Inventory

This paper presents a compilation and summary of design criteria, performance, and cost data from 22 operating municipal and industrial granular activated carbon (GAC) installations that treat water and wastewater or process food and beverage products. Guidance for using this inf...

241

Carbon Dioxide Laser Guidelines  

PubMed Central

The carbon dioxide (CO2) laser is a versatile tool that has applications in ablative lasing and caters to the needs of routine dermatological practice as well as the aesthetic, cosmetic and rejuvenation segments. This article details the basics of the laser physics as applicable to the CO2 laser and offers guidelines for use in many of the above indications. PMID:20808594

Krupa Shankar, DS; Chakravarthi, M; Shilpakar, Rachana

2009-01-01

242

Nanoindentation of carbon materials  

Microsoft Academic Search

The compressive behaviour of carbon materials has been investigated by modelling the recently developed method of nanoindentation. Molecular dynamics simulations are employed to investigate the indentation of a diamond cube-corner apex into graphite {0001}, diamond {001} and a C60 substrate. Simulations performed on graphite show that the crystal undergoes an elastic deformation. Indentation of diamond shows some elastic behaviour but

David Christopher; Roger Smith; Asta Richter

2001-01-01

243

Wettability alteration in carbonates  

Microsoft Academic Search

Fractured oil-wet carbonate reservoirs are often located at low temperatures and pressures, and the oil recovery by pure pressure depletion is usually low. The potential for improved oil recovery (IOR) is therefore very high. An IOR method is to change the wettability of the reservoir towards more water-wet conditions so that water can spontaneously imbibe into the matrix blocks and

Dag C Standnes; Tor Austad

2003-01-01

244

Populations of Carbon Stars  

NASA Astrophysics Data System (ADS)

Carbon stars in the Galaxy do not constitute a single family, but may be divided over several types with distinctive spectroscopic and photometric properties. A subtype of the N stars, characterised by high velocities and weak CN bands, may have been captured by the Milky Way from a cannibalised dwarf galaxy.

Lloyd Evans, T.

2011-09-01

245

GLOBAL TERRESTRIAL CARBON CYCLE  

EPA Science Inventory

There is great uncertainty with regard to the future role of the terrestrial biosphere in the global carbon cycle, arising from both an inadequate understanding of current pools and fluxes as well as the potential effects of rising atmospheric concentrations of CO, on natural eco...

246

Changing Planet: Black Carbon  

NSDL National Science Digital Library

This video addresses two ways in which black carbon contributes to global warming - when in the atmosphere, it absorbs sunlight and generates heat, warming the air; when deposited on snow and ice, it changes the albedo of the surface. The video is effective in communicating about a problem frequently underrepresented in discussions of climate change and also public health.

Learn, Nbc; Universe, Windows T.

247

Calcium carbonate with magnesium overdose  

MedlinePLUS

The combination of calcium carbonate and magnesium is commonly found in antacids, which are medicines that provide heartburn relief. Calcium carbonate with magnesium overdose occurs when someone accidentally or ...

248

Vaccine Delivery by Carbon Nanotubes  

Microsoft Academic Search

Novel nanomaterials, such as carbon nanotubes, are under active investigation for potential use in biomedical applications. In this issue of Chemistry & Biology, researchers describe antigen-antibody interactions and immune responses using peptide-carbon nanotube conjugates.

Marc in het Panhuis

2003-01-01

249

Plasmachemical Synthesis of Carbon Suboxide  

E-print Network

if solid carbon is considered to be kinetically limited, and therefore not a product, then carbon suboxide is more likely to be a product under these pseudo-equilibrium conditions. Experimentally, solid films were produced in a dielectric barrier discharge...

Geiger, Robert

2012-12-11

250

Dewatering Peat With Activated Carbon  

NASA Technical Reports Server (NTRS)

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

Rohatgi, N. K.

1984-01-01

251

Sensor applications of carbon nanotubes  

E-print Network

A search of published research on sensing mechanisms of carbon nanotubes was performed to identify applications in which carbon nanotubes might improve on current sensor technologies, in either offering improved performance, ...

Rushfeldt, Scott I

2005-01-01

252

Bioenergy, the Carbon Cycle, and Carbon Policy  

NASA Astrophysics Data System (ADS)

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

Kammen, D. M.

2003-12-01

253

Where is mantle's carbon?  

NASA Astrophysics Data System (ADS)

Due to the strongly reducing conditions (the presence of metallic iron was suggested both by experiments [1] and theory [2]), diamond was believed to be the main host of carbon through most of the lower mantle [3]. We showed [4] that cementite Fe3C is another good candidate to be the main host of "reduced" carbon in the mantle, reinforcing an earlier hypothesis [5]. The fate of "oxidised" carbon (in subducted slabs) is of particular importance - if carbonates decompose producing fluid CO2, this would have important implications for the chemistry and rheology of the mantle. Knowledge of crystal structures and phase diagrams of carbonates is crucial here. The high-pressure structures of CaCO3 were predicted [6] and subsequently verified by experiments. For MgCO3, Isshiki et al. [7] found a new phase above 110 GPa, and several attempts were made to solve it [8,9]. Here [4], using an evolutionary algorithm for crystal structure prediction [10], we show that there are two post-magnesite phases at mantle-relevant pressure range, one stable at 82-138 GPa, and the other from 138 GPa to ~160 GPa. Both are based on threefold rings of CO4-tetrahedra and are more favourable than all previously proposed structures. We show that through most of the P-T conditions of the mantle, MgCO3 is the major host of oxidized carbon in the Earth. We predict the possibility of CO2 release at the very bottom of the mantle (in SiO2-rich basaltic part of subducted slabs), which could enhance partial melting of rocks and be related to the geodynamical differences between the Earth and Venus. 1.Frost D.J., Liebske C., Langenhorst F., McCammon C.A., Tronnes R.G., Rubie D.C. (2004). Experimental evidence for the existence of iron-rich metal in the Earth's lower mantle. Nature 428, 409-412. 2.Zhang F., Oganov A.R. (2006). Valence and spin states of iron impurities in mantle-forming silicates. Earth Planet. Sci. Lett. 249, 436-443. 3.Luth R.W. (1999). Carbon and carbonates in the mantle. In: Mantle Petrology: Field Observations and High Pressure Experimentation: A Tribute to Francis R. (Joe) Boyd. Geochemical Soc., Special Publication No. 6. Eds: Y. Fei, C.M. Bertka, B.O. Mysen. 4.Oganov A.R., Ono S., Ma Y., Glass C.W., Garcia A. (2008). Novel high-pressure structures of MgCO3, CaCO3 and CO2 and their role in the Earth's lower mantle. Earth Planet. Sci. Lett. 273, 38-47 5.Scott H.P.,, Williams Q., Knittle E. (2001). Stability and equation of state of Fe3C to 73 GPa: Implications for carbon in the Earth's core. Geoph. Res. Lett. 28, 1875-1878. 6.Oganov A.R., Glass C.W., Ono S. (2006). High-pressure phases of CaCO3: crystal structure prediction and experiment. Earth Planet. Sci. Lett. 241, 95-103. 7.Isshiki M., Irifune T., Hirose K., Ono S., Ohishi Y., Watanuki T., Nishibori E., Takadda M., and Sakata M. (2004). Stability of Magnesite and its high-pressure form in the lowermost mantle. Nature 427, 60-63. 8.Skorodumova N.V., Belonoshko A.B., Huang L., Ahuja R., Johansson B. (2005) Stability of the MgCO3 structures under lower mantle conditions. Am. Mineral. 90, 1008-1011. 9.Panero W.R., Kabbes J.E. (2008). Mantle-wide sequestration of carbon in silicates and the structure of magnesite II. Geophys. Res. Lett. 35, L14307. 10.Oganov A.R., Glass C.W. (2006). Crystal structure prediction using ab initio evolutionary algorithms: principles and applications. J. Chem. Phys. 124, art. 244704.

Oganov, A. R.; Ono, S.; Ma, Y.

2008-12-01

254

ISSUES IN EVALUATING CARBON SEQUESTRATION AND ATTRIBUTING CARBON CREDITS TO GRASSLAND RESTORATION EFFORTS  

E-print Network

ISSUES IN EVALUATING CARBON SEQUESTRATION AND ATTRIBUTING CARBON CREDITS TO GRASSLAND RESTORATION examines biological carbon sequestration using a grassland restoration as a model system. Chapter 1 for biological carbon sequestration. In this analysis, we found that significantly greater soil carbon

Wisconsin at Madison, University of

255

Poly(carbonate-imide) polymer  

NASA Technical Reports Server (NTRS)

A novel series of polymers and copolymers based on a polyimide backbone with the incorporation of carbonate moieties along the backbone. The process for preparing these polymers and copolymers is also disclosed as is a novel series of dinitrodiphenyl carbonates and diaminodiphenyl carbonates. The novel polymers and copolymers exhibit high temperature capability and because of the carbonate unit, many exhibit a high degree of order and/or crystallinity.

St. Clair, Terry L. (Inventor); Maudgal, Shubha (Inventor); Pratt, J. Richard (Inventor)

1987-01-01

256

Poly (Carbonate-Mide) Polymer  

NASA Technical Reports Server (NTRS)

A novel series of polymers and copolymers based on a polymide backbone with the incorporation of carbonate moieties along the backbone is presented. The preparation process for the polymers and copolymers is disclosed together with a novel series of dinitrodiphenyl carbonates and diaminodiphenyl carbonates. The novel polyners and copolymers exhibit high temperature capability and because of the carbonate unit, many exhibit a high degree of order and/or crystallinity.

St.clair, T. L. (inventor); Maudgal, S. (inventor); Pratt, J. R. (inventor)

1986-01-01

257

Controllable fabrication of carbon aerogels  

Microsoft Academic Search

Nano-pore carbon aerogels were prepared by the sol-gel polymerization of resorcinol (1, 3-dihydroxybenzene)(C6H4(OH)2) with formaldehyde (HCHO) in a slightly basic aqueous solution, followed by super-critical drying under liquid carbon dioxide as super-critical media and carbonization at 700 °C under N2 gas atmosphere. The key of the work is to fabricate carbon aerogels with controllable nano-pore structure, which means extremely high

Ya'ning FENG; Lei MIAO; Sakae TANEMURA; Masaki TANEMURA; Kenzi SUZUKI

2006-01-01

258

Method of producing carbon black  

SciTech Connect

The tint residual of produced carbon black appears to go through a maximum value at a toluene photelometer of between about 65 and about 75. A process is disclosed for maximizing the tint residual of carbon black product at constant reactor volume and combustion gas flow by measuring the photelometer of the produced carbon black and changing the feedstock rate so that the photelometer of the carbon black being produced falls within the range of 65 to about 75.

Cheng, P. J.

1985-03-05

259

The biocompatibility of carbon nanotubes  

Microsoft Academic Search

Carbon nanotubes (CNT) are well-ordered, high aspect ratio allotropes of carbon. The two main variants, single-walled carbon nanotubes (SWCNT) and multi-walled carbon nanotubes (MWCNT) both possess a high tensile strength, are ultra-light weight, and have excellent chemical and thermal stability. They also possess semi- and metallic-conductive properties. This startling array of features has led to many proposed applications in the

S. K. Smart; A. I. Cassady; G. Q. Lu; D. J. Martin

2006-01-01

260

Carbon nanotubes: properties and application  

Microsoft Academic Search

Carbon nanotubes are unique tubular structures of nanometer diameter and large length\\/diameter ratio. The nanotubes may consist of one up to tens and hundreds of concentric shells of carbons with adjacent shells separation of ?0.34nm. The carbon network of the shells is closely related to the honeycomb arrangement of the carbon atoms in the graphite sheets. The amazing mechanical and

Valentin N Popov

2004-01-01

261

Carbon sequestration and eruption hazards  

Microsoft Academic Search

In order to reduce the buildup of carbon dioxide in the atmosphere, proposals have been made to sequestrate carbon in ocean, or in coal mines and other underground formations. High gas concentration in ocean or underground formations has to potential to power gas-driven eruptions. In this presentation, possible eruption hazards are explored. Whenever carbon dioxide is sequestrated in the form

Y. Zhang

2007-01-01

262

8, 62656280, 2011 Ocean carbonate  

E-print Network

altering the efficiency of primary produc- ers consuming DIC and reducing the effect of nutrient limitation Introduction The marine organic carbon and carbonate pumps are affected by increasing atmo-20 spheric carbon dioxide (CO2) concentrations through marine organisms. Enhanced CO2 in seawater has been observed

Phipps, Steven J.

263

Gas permeability of carbon aerogels  

Microsoft Academic Search

Carbon aerogels are synthesized via the aqueous polycondensation of resorcinol with formaldehyde, followed by supercritical drying and subsequent pyrolysis at 1050 [degree]C. As a result of their interconnected porosity, ultrafine cell\\/pore size, and high surface area, carbon aerogels have many potential applications such as supercapacitors, battery electrodes, catalyst supports, and gas filters. The performance of carbon aerogels in the latter

F. M. Kong; J. D. LeMay; S. S. Hulsey; C. T. Alviso; R. W. Pekala

1993-01-01

264

Carbon Cloth Supports Catalytic Electrodes  

NASA Technical Reports Server (NTRS)

Carbon cloth is starting material for promising new catalytic electrodes. Carbon-cloth electrodes are more efficient than sintered-carbon configuration previously used. Are also chemically stable and require less catalyst--an important economic advantage when catalyst is metal such as platinum.

Lu, W. T. P.; Ammon, R. L.

1983-01-01

265

Porous carbon EOS: numerical analysis  

Microsoft Academic Search

In this paper, we address the problem of direct simulation of laser-driven shock experiments aiming at determining the equation of state (EOS) of carbon using the “relative” impedance mismatch method. In particular, using tabulated carbon EOS (SESAME library, material number 7830), we have found some difficulties in reducing the initial density of the material in simulations with porous carbon. We

A. Aliverdiev; D. Batani; R. Dezulian; T. Vinci

2010-01-01

266

Dispersion toughened silicon carbon ceramics  

DOEpatents

Fracture resistant silicon carbide ceramics are provided by incorporating therein a particulate dispersoid selected from the group consisting of (a) a mixture of boron, carbon and tungsten, (b) a mixture of boron, carbon and molybdenum, (c) a mixture of boron, carbon and titanium carbide, (d) a mixture of aluminum oxide and zirconium oxide, and (e) boron nitride. 4 figures.

Wei, G.C.

1984-01-01

267

Getting to Know Global Carbon  

NSDL National Science Digital Library

GLOBE Carbon Cycle is focused on bringing the most cutting edge research and research techniques in the field of terrestrial ecosystem carbon cycling into the classroom. Students can collect data about their school field site through existing GLOBE protocols of phenology, land cover and soils as well as through new protocols focused on biomass and carbon stocks in vegetation.

2013-01-01

268

CARBON IN FORESTS: QUALITY MATTERS  

EPA Science Inventory

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

269

Carbon sequestration research and development  

Microsoft Academic Search

Predictions of global energy use in the next century suggest a continued increase in carbon emissions and rising concentrations of carbon dioxide (COâ) in the atmosphere unless major changes are made in the way we produce and use energy--in particular, how we manage carbon. For example, the Intergovernmental Panel on Climate Change (IPCC) predicts in its 1995 ''business as usual''

Dave Reichle; John Houghton; Bob Kane; Jim Ekmann

1999-01-01

270

8, 73157337, 2008 Carbon dioxide  

E-print Network

ACPD 8, 7315­7337, 2008 Carbon dioxide distributions over Europe C. Gurk et al. Title Page Abstract distributions of carbon dioxide over Europe C. Gurk1 , H. Fischer1 , P. Hoor1 , M.G. Lawrence1 , J. Lelieveld1 Publications on behalf of the European Geosciences Union. 7315 #12;ACPD 8, 7315­7337, 2008 Carbon dioxide

Paris-Sud XI, Université de

271

Carbon Fiber Risk Analysis. [conference  

NASA Technical Reports Server (NTRS)

The scope and status of the effort to assess the risks associated with the accidental release of carbon/graphite fibers from civil aircraft is presented. Vulnerability of electrical and electronic equipment to carbon fibers, dispersal of carbon fibers, effectiveness of filtering systems, impact of fiber induced failures, and risk methodology are among the topics covered.

1979-01-01

272

1, 393412, 2004 Carbon isotope  

E-print Network

BGD 1, 393­412, 2004 Carbon isotope anomaly in the major plant C1 pool F. Keppler et al. Title Page Biogeosciences Discussions is the access reviewed discussion forum of Biogeosciences Carbon isotope anomaly.keppler@qub.ac.uk) 393 #12;BGD 1, 393­412, 2004 Carbon isotope anomaly in the major plant C1 pool F. Keppler et al. Title

Boyer, Edmond

273

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

PubMed

Recent carbon-carbon bond forming reactions of carbon dioxide with alkenes, alkynes, dienes, aryl zinc compounds, aryl boronic esters, aryl halides, and arenes having acidic C-H bonds are reviewed in which transition-metal catalysts play an important role. PMID:22859266

Tsuji, Yasushi; Fujihara, Tetsuaki

2012-10-14

274

Arnold Schwarzenegger THE CARBON DIOXIDE  

E-print Network

i Arnold Schwarzenegger Governor THE CARBON DIOXIDE ABATEMENT POTENTIAL OF CALIFORNIA'S MID, Afzal Siddiqui, and Judy Lai. 2011. The Carbon Dioxide Abatement Potential of California's Mid/Agricultural/Water EndUse Energy Efficiency · Renewable Energy Technologies · Transportation The Carbon Dioxide

275

14 April 2001 tmospheric carbon dioxide  

E-print Network

emissions is through increased carbon sequestration into forests. In a large-scale assessment, Birdsey- ing carbon sequestration in southern forests. Carbon sequestration via southern pine forests may policy commitments. Keywords: carbon sequestration; southern pine forests ABSTRACT MEETING GLOBAL POLICY

Teskey, Robert O.

276

21 CFR 184.1619 - Potassium carbonate.  

...exposing the resultant potassium to carbon dioxide; (2) By treating a solution of potassium hydroxide with excess carbon dioxide to produce potassium carbonate...solution of potassium hydroxide with carbon dioxide to produce potassium...

2014-04-01

277

Carbon sequestration and its role in the global carbon cycle  

USGS Publications Warehouse

For carbon sequestration the issues of monitoring, risk assessment, and verification of carbon content and storage efficacy are perhaps the most uncertain. Yet these issues are also the most critical challenges facing the broader context of carbon sequestration as a means for addressing climate change. In response to these challenges, Carbon Sequestration and Its Role in the Global Carbon Cycle presents current perspectives and research that combine five major areas: • The global carbon cycle and verification and assessment of global carbon sources and sinks • Potential capacity and temporal/spatial scales of terrestrial, oceanic, and geologic carbon storage • Assessing risks and benefits associated with terrestrial, oceanic, and geologic carbon storage • Predicting, monitoring, and verifying effectiveness of different forms of carbon storage • Suggested new CO2 sequestration research and management paradigms for the future. The volume is based on a Chapman Conference and will appeal to the rapidly growing group of scientists and engineers examining methods for deliberate carbon sequestration through storage in plants, soils, the oceans, and geological repositories.

McPherson, Brian J.; Sundquist, Eric T.

2009-01-01

278

Global carbon budget 2013  

NASA Astrophysics Data System (ADS)

Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and a methodology to quantify all major components of the global carbon budget, including their uncertainties, based on the combination of a range of data, algorithms, statistics and model estimates and their interpretation by a broad scientific community. We discuss changes compared to previous estimates, consistency within and among components, alongside methodology and data limitations. CO2 emissions from fossil-fuel combustion and cement production (EFF) are based on energy statistics, while emissions from land-use change (ELUC), mainly deforestation, are based on combined evidence from land-cover change data, fire activity associated with deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the annual changes in concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. The variability in SOCEAN is evaluated for the first time in this budget with data products based on surveys of ocean CO2 measurements. The global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms of the global carbon budget and compared to results of independent dynamic global vegetation models forced by observed climate, CO2 and land cover change (some including nitrogen-carbon interactions). All uncertainties are reported as ±1?, reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. For the last decade available (2003-2012), EFF was 8.6 ± 0.4 GtC yr-1, ELUC 0.9 ± 0.5 GtC yr-1, GATM 4.3 ± 0.1 GtC yr-1, SOCEAN 2.5 ± 0.5 GtC yr-1, and SLAND 2.8 ± 0.8 GtC yr-1. For year 2012 alone, EFF grew to 9.7 ± 0.5 GtC yr-1, 2.2% above 2011, reflecting a continued growing trend in these emissions, GATM was 5.1 ± 0.2 GtC yr-1, SOCEAN was 2.9 ± 0.5 GtC yr-1, and assuming an ELUC of 1.0 ± 0.5 GtC yr-1 (based on the 2001-2010 average), SLAND was 2.7 ± 0.9 GtC yr-1. GATM was high in 2012 compared to the 2003-2012 average, almost entirely reflecting the high EFF. The global atmospheric CO2 concentration reached 392.52 ± 0.10 ppm averaged over 2012. We estimate that EFF will increase by 2.1% (1.1-3.1%) to 9.9 ± 0.5 GtC in 2013, 61% above emissions in 1990, based on projections of world gross domestic product and recent changes in the carbon intensity of the economy. With this projection, cumulative emissions of CO2 will reach about 535 ± 55 GtC for 1870-2013, about 70% from EFF (390 ± 20 GtC) and 30% from ELUC (145 ± 50 GtC). This paper also documents any changes in the methods and data sets used in this new carbon budget from previous budgets (Le Quéré et al., 2013). All observations presented here can be downloaded from the Carbon Dioxide Information Analysis Center (doi:10.3334/CDIAC/GCP_2013_V2.3).

Le Quéré, C.; Peters, G. P.; Andres, R. J.; Andrew, R. M.; Boden, T. A.; Ciais, P.; Friedlingstein, P.; Houghton, R. A.; Marland, G.; Moriarty, R.; Sitch, S.; Tans, P.; Arneth, A.; Arvanitis, A.; Bakker, D. C. E.; Bopp, L.; Canadell, J. G.; Chini, L. P.; Doney, S. C.; Harper, A.; Harris, I.; House, J. I.; Jain, A. K.; Jones, S. D.; Kato, E.; Keeling, R. F.; Klein Goldewijk, K.; Körtzinger, A.; Koven, C.; Lefèvre, N.; Maignan, F.; Omar, A.; Ono, T.; Park, G.-H.; Pfeil, B.; Poulter, B.; Raupach, M. R.; Regnier, P.; Rödenbeck, C.; Saito, S.; Schwinger, J.; Segschneider, J.; Stocker, B. D.; Takahashi, T.; Tilbrook, B.; van Heuven, S.; Viovy, N.; Wanninkhof, R.; Wiltshire, A.; Zaehle, S.

2014-06-01

279

Development of a carbon formation reactor for carbon dioxide reduction  

NASA Technical Reports Server (NTRS)

Applied research, engineering development, and performance evaluation were conducted on a process for formation of dense carbon by pyrolysis of methane. Experimental research showed that dense (0.7 to 1.6 g/cc bulk density and 1.6 to 2.2 g/cc solid density) carbon can be produced by methane pyrolysis in quartzwool-packed quartz tubes at temperatrues of 1100 to 1300 C. This result supports the condensation theory of pyrolytic carbon formation from gaseous hydrocarbons. A full-scale Breadboard Carbon Formation Reactor (CFR) was designed, fabricated, and tested at 1100 to 1200 C with 380 to 2280 sccm input flows of methane. Single-pass conversion of methane to carbon ranged from 60 to 100 percent, with 89 percent average conversion. Performance was projected for an Advanced Carbon Reactor Subsystem (ACRS) which indicated that the ACRS is a viable option for management of metabolic carbon on long-duration space missions.

Noyes, G.

1985-01-01

280

Erosion of soil organic carbon: implications for carbon sequestration  

USGS Publications Warehouse

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

Van Oost, K.; Van Hemelryck, H.; Harden, J.W.

2009-01-01

281

The reinforcing mechanism of carbon fiber in composite adhesive for bonding carbon\\/carbon composites  

Microsoft Academic Search

A carbon fiber reinforced adhesive was developed for bonding carbon\\/carbon composites. The Weibull distribution method was used to analyze the bonding strength data, and the results showed that when the volume fraction of carbon fiber was 6vol.%, the Weibull modulus was 42.9393 and the bonding strength of the adhesive was 11.3763MPa. A model was proposed to explain the reinforcement of

Yunfeng Zhang; Ruiying Luo; Jiangsong Zhang; Qiao Xiang

2011-01-01

282

High Temperature Thermomechanical Behavior of Carbon-Phenolic and Carbon-Carbon Composites, II. Results  

Microsoft Academic Search

Tests were conducted to validate the model and the CHAR computer code previously developed for calculating the thermomechanical behavior of carbon-phenolic and carbon-carbon composites exposed to high temperatures. Temperature distributions in and damage of rapidly heated carbon-phenolic composites were measured. The data com pared well to the results calculated by the code. Parametric studies were also performed, the results of

Hugh L. N. Mcmanus; George S. Springer

1992-01-01

283

Carbon sequestration by switchgrass  

NASA Astrophysics Data System (ADS)

Increasing levels of carbon dioxide (CO2), which is partly due to use of fossil fuel, is primarily responsible for global climate warming. Producing and using switchgrass for bioenergy can help reduce atmospheric CO2 buildup by partly replacing use of fossil fuels and by carbon (C) sequestration. Switchgrass (Panicum virgatum L) is a potential bioenergy crop suited to the southeastern U.S. The objective of this study was to determine the effects of agricultural management practices on C sequestration by switchgrass. Field experiments were designed so that differences in row spacing, nitrogen (N) rate, switchgrass cultivar, harvest frequency, and soil type on C sequestration would be evaluated. Soil C dynamic studies indicated that soil C mineralization, microbial biomass C, and C turnover tended to increase with time after switchgrass establishment in Norfolk sandy sod. These changes were more apparent in 0 to 15 cm than 15 to 30 cm of the sandy loam soil. Ten years of continuous switchgrass resulted in higher soil C level than nearby fallow soils, but several years of continuous grass may be need before increases are measurable. Results from this study imply that management practices can impact soil C sequestration with switchgrass, such as several years for humification by conversion of the root accumulation to the stable soil C pool. The effect of N was to increase N but not C concentration of roots, which imply that any increases in C sequestration by switchgrass would be due to increases in root biomass. Switchgrass roots were more dense in Pacolet clay soil than the other soils used in this study. Carbon storage in switchgrass, shoots increased as row width and N rate increased. Carbon storage in shoots and roots generally increased with time after switchgrass establishment, and rate of increase of C storage in root was higher than that in shoot. Carbon partitioning analyses showed that C storage was soil C > root C > shoot C. The root/shoot ratio of C storage was 2.2, and this implied that C partitioning to roots plays a key role in C sequestration by switchgrass. Carbon storage in the overall switchgrass-soil system showed an upward trend after switchgrass establishment.

Ma, Zhiqin

1999-11-01

284

Carbon Capture and Storage, 2008  

ScienceCinema

The U.S. Department of Energy is researching the safe implementation of a technology called carbon sequestration, also known as carbon capture and storage, or CCS. Based on an oilfield practice, this approach stores carbon dioxide, or CO2 generated from human activities for millennia as a means to mitigate global climate change. In 2003, the Department of Energys National Energy Technology Laboratory formed seven Regional Carbon Sequestration Partnerships to assess geologic formations suitable for storage and to determine the best approaches to implement carbon sequestration in each region. This video describes the work of these partnerships.

None

2010-01-08

285

Understanding the Global Carbon Cycle  

NSDL National Science Digital Library

The site offers charts and graphs to aid in a detailed explanation of where carbon comes from and where it goes. Supplementing the main topic, links lead to the topics Carbon and Land Use, Missing Carbon Sink, and Forest Sequestered Carbon Dioxide. Their conclusion is that the major contributor to climatic change, and hence the human activity most in need of change, is use of fossil fuels for energy. Advances in the technology of renewable energy sources, including wood-derived fuels, might reduce our reliance on fossil fuels and thus reduce global emissions of carbon dioxide significantly.

286

Method for making thin carbon foam electrodes  

Microsoft Academic Search

A method for fabricating thin, flat carbon electrodes by infiltrating highly porous carbon papers, membranes, felts, metal fibers\\/powders, or fabrics with an appropriate carbon foam precursor material. The infiltrated carbon paper, for example, is then cured to form a gel-saturated carbon paper, which is subsequently dried and pyrolyzed to form a thin sheet of porous carbon. The material readily stays

Richard W. Pekala; Steven T. Mayer; James L. Kaschmitter; Robert L. Morrison

1999-01-01

287

Method for making thin carbon foam electrodes  

Microsoft Academic Search

A method for fabricating thin, flat carbon electrodes by infiltrating highly porous carbon papers, membranes, felts, metal fibers\\/powders, or fabrics with an appropriate carbon foam precursor material is disclosed. The infiltrated carbon paper, for example, is then cured to form a gel-saturated carbon paper, which is subsequently dried and pyrolyzed to form a thin sheet of porous carbon. The material

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

1999-01-01

288

CALCULATING THE CARBON FOOTPRINT SUPPLY CHAIN FOR  

E-print Network

CALCULATING THE CARBON FOOTPRINT SUPPLY CHAIN FOR THE SEMICONDUCTOR INDUSTRY By: Yasser Dessouky #12;Carbon Footprint Supply Chain Carbon Trust defines carbon footprint of a supply chain as follows: "The carbon footprint of a product is the carbon dioxide emitted across the supply chain for a single

Su, Xiao

289

Influence of carbon nanotubes addition on carbon–carbon supercapacitor performances in organic electrolyte  

Microsoft Academic Search

This paper presents the performances of 4cm2 supercapacitors cells assembled with 200?m thick active material films composed with activated carbon and carbon nanotubes mixture in organic electrolyte. Galvanostatic and electrochemical spectroscopy impedance measurements have been carried out. Galvanostatic measurements show that both internal resistance and specific capacitance decrease when the carbon nanotubes content increases in the active material. With 15%

C. Portet; P. L. Taberna; P. Simon; E. Flahaut

2005-01-01

290

Biomechanical and biological properties of the implant material carbon-carbon composite covered with pyrolytic carbon  

Microsoft Academic Search

The aim of this study was to test C\\/C material (carbonized, graphitized or covered with pyrolytic carbon) designated for the use in orthopaedic and bone surgery. Using an in vitro assay we confirmed, that the cell proliferation was exhibited the mostly on the C\\/C composite coated with pyrolitic carbon and afterwards polished. The two latest of subsequent water extracts of

V. PesÁkovÁ; Z. Kle´zl; K. Bali´k; M. Adam

2000-01-01

291

Depositing Diamondlike Carbon Films  

NASA Technical Reports Server (NTRS)

New process demonstrated to make thin films (usually thousands of angstroms to few microns thick) that have properties of diamonds. Various plasma and ion-beam techniques employed to generate films. Films made by radio-frequency plasma decomposition of hydrocarbon gas or other alkanes, by low-energy carbon-ion-beam deposition, or by ion plating and dual ion technique using carbon target. Advantages of new process over others are films produced, though amorphous, are clear, extremely hard, chemically inert, of high resistivity, and have index of refraction of 3.2 properties similar to those of single-crystal diamonds. Films have possible uses in microelectronic applications, high-energy-laser and plastic windows, corrosion protection for metals, and other applications where desired properties of film shaped during the film-formation process.

Mirtich, M. J.; Sovey, J. S.; Banks, B. A.

1986-01-01

292

Carbon materials for supercapacitors  

NASA Astrophysics Data System (ADS)

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

Gao, Yang

293

Defects in carbon nanostructures  

SciTech Connect

Previous high-resolution electron microscopy (HREM) observations of carbon nanotubes have led to a Russian doll' structural model that is based on hollow concentric cylinders capped at both ends. The structures of the carbon nanotubes and particles were characterized here by bulk physical and chemical property measurements. The individual nanostructure is as compressible as graphite in the c-axis, and such nanostructures can be intercalated with potassium and rubidium, leading to a saturation composition of Mc[sub 8]'. These results are counter to expectations that are based on a Russian doll structure. HREM after intercalation with potassium and deintercalation indicates that individual nanoparticles are a paper-mache' of smaller graphite layers. Direct current magnetization and electron spin resonance measurements indicate that the electronic properties of the nanostructures are distinctly different from those of graphite. Although the nanostructures have distinct morphologies and electronic properties, they are highly defective and have a local structure similar to turbostratic graphite.

Zhou, O.; Fleming, R.M.; Murphy, D.W.; Chen, C.H.; Haddon, R.C.; Ramirez, A.P.; Glarum, S.H. (AT T Bell Laboratories, Murray Hill, NJ (United States))

1994-03-25

294

Carbon Cycle of Mars  

NSDL National Science Digital Library

Carbon Cycle of Mars is a Windows to the Universe Exploratour and provides information and images about carbon dioxide and the lower atmosphere of Mars. Windows to the Universe is a user-friendly learning system pertaining to the Earth and Space sciences. The objective of this project is to develop an innovative and engaging web site that spans the Earth and Space sciences and includes a rich array of documents, including images, movies, animations, and data sets that explore the Earth and Space sciences and the historical and cultural ties between science, exploration and the human experience. Links at the top of each page allow users to navigate between beginner, intermediate, and advanced options for each topic level.

Johnson, Roberta

2000-07-01

295

Global carbon budget 2013  

NASA Astrophysics Data System (ADS)

Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe datasets and a methodology to quantify all major components of the global carbon budget, including their uncertainties, based on the combination of a range of data, algorithms, statistics and model estimates and their interpretation by a broad scientific community. We discuss changes compared to previous estimates consistency within and among components, alongside methodology and data limitations. CO2 emissions from fossil-fuel combustion and cement production (EFF) are based on energy statistics, while emissions from Land-Use Change (ELUC), including deforestation, are based on combined evidence from land-cover change data, fire activity in regions undergoing deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the annual changes in concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. The variability in SOCEAN is evaluated for the first time in this budget with data products based on surveys of ocean CO2 measurements. The global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms of the global carbon budget and compared to results of Dynamic Global Vegetation Models. All uncertainties are reported as ± 1 sigma, reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. For the last decade available (2003-2012), EFF was 8.6 ± 0.4 GtC yr-1, ELUC 0.8 ± 0.5 GtC yr-1, GATM 4.3 ± 0.1 GtC yr-1, SOCEAN 2.6 ± 0.5 GtC yr-1, and SLAND 2.6 ± 0.8 GtC yr-1. For year 2012 alone, EFF grew to 9.7 ± 0.5 GtC yr-1, 2.2% above 2011, reflecting a continued trend in these emissions; GATM was 5.2 ± 0.2 GtC yr-1, SOCEAN was 2.9 ± 0.5 GtC yr-1, and assuming and ELUC of 0.9 ± 0.5 GtC yr-1 (based on 2001-2010 average), SLAND was 2.5 ± 0.9 GtC yr-1. GATM was high in 2012 compared to the 2003-2012 average, almost entirely reflecting the high EFF. The global atmospheric CO2 concentration reached 392.52 ± 0.10 ppm on average over 2012. We estimate that EFF will increase by 2.1% (1.1-3.1%) to 9.9 ± 0.5 GtC in 2013, 61% above emissions in 1990, based on projections of World Gross Domestic Product and recent changes in the carbon intensity of the economy. With this projection, cumulative emissions of CO2 will reach about 550 ± 60 GtC for 1870-2013, 70% from EFF (390 ± 20 GtC) and 30% from ELUC (160 ± 55 GtC). This paper is intended to provide a baseline to keep track of annual carbon budgets in the future. All data presented here can be downloaded from the Carbon Dioxide Information Analysis Center (10.3334/CDIAC/GCP_2013_v1.1).

Le Quéré, C.; Peters, G. P.; Andres, R. J.; Andrew, R. M.; Boden, T.; Ciais, P.; Friedlingstein, P.; Houghton, R. A.; Marland, G.; Moriarty, R.; Sitch, S.; Tans, P.; Arneth, A.; Arvanitis, A.; Bakker, D. C. E.; Bopp, L.; Canadell, J. G.; Chini, L. P.; Doney, S. C.; Harper, A.; Harris, I.; House, J. I.; Jain, A. K.; Jones, S. D.; Kato, E.; Keeling, R. F.; Klein Goldewijk, K.; Körtzinger, A.; Koven, C.; Lefèvre, N.; Omar, A.; Ono, T.; Park, G.-H.; Pfeil, B.; Poulter, B.; Raupach, M. R.; Regnier, P.; Rödenbeck, C.; Saito, S.; Schwinger, J.; Segschneider, J.; Stocker, B. D.; Tilbrook, B.; van Heuven, S.; Viovy, N.; Wanninkhof, R.; Wiltshire, A.; Zaehle, S.; Yue, C.

2013-11-01

296

Filling the carbon nanocages  

NASA Astrophysics Data System (ADS)

Twenty elements were codeposited with carbon in an arc discharge between graphite electrodes. The majority of them were evaporated from composite anodes that contained the elements or their oxides stuffed into central bores in the graphite rods. The deposits, found in the soot at the reactor walls or as slag at the cathode, were characterized using scanning and transmission electron microscopy, electron energy loss spectroscopy, and x-ray diffraction. The products fall into four categories: (1) elements that can be encapsulated in the form of their carbides (B, V, Cr, Mn, Y, Zr, Nb, Mo); (2) elements that are not encapsulated but tolerate the formation of graphitic carbon cages (Cu, Zn, Pd, Ag, Pt); (3) elements that form stable carbides, competing with and pre-empting the carbon supply for the graphitic cage formation (Al, Si, Ti, W); and (4) the iron-group metals (Fe, Co, Ni) that stimulate the formation of single-walled tubes and strings of nanobeads in the conventional arc discharge condition, and produce the nanometer-size carbon-coated ferromagnetic particles in a modified arc discharge in which metals are in molten form in graphite crucible anodes exposed to a helium jet stream. The criterion determining the formation according to one of the four categories is discussed on the basis of this extended study. It is apparent that the physical properties such as vapor pressure, melting and boiling points, the completeness of the electronic shells of the elements, or their heat of carbide formation are not sufficient to explain the selectivity of the encapsulation without exceptions. A hypothesis is advanced that emphasizes the existence of the carbide, interfacial compatibility with the graphitic network, as well as the transport and supply parameters in the reaction space.

Seraphin, Supapan; Zhou, Dan; Jiao, Jun

1996-08-01

297

Wool is 44% Carbon  

Microsoft Academic Search

Carbon Footprint is one of the Lovely Weather Donegal Residencies projects initiated by Leonardo\\/Olats and the Regional Cultural Centre of Donegal. It is a process-based work using Inishowen sheep wool and hand spinning as the primary metaphors to articulate the intrinsic relationship between climate change and economics. This project works to rejuvenate the use of local wool and low-tech\\/slow-tech making

Seema Goel

2012-01-01

298

Wool is 44% Carbon  

Microsoft Academic Search

Carbon Footprint is one of the Lovely Weather Donegal Residencies projects initiated by Leonardo\\/Olats and the Regional Cultural Centre of Donegal. It is a process-based work using Inishowen sheep wool and hand spinning as the primary metaphors to articulate the intrinsic relationship between climate change and economics. This project works to rejuvenate the use of local wool and low-tech\\/slow-tech making

Seema Goel

299

Modeling Carbon Dioxide Levels  

NSDL National Science Digital Library

In this activity students will explore levels of Carbon Dioxide ( C02) in the atmosphere over time. There is concern that levels of C02 are rising; and finding a good mathematical model for CO2 levels is an important part of determining if this is attributable to human technology. Students draw a scatter plot, choose two points to create a linear model for the data, then use the model to make predictions.

2009-01-01

300

Closing carbon cycles  

Microsoft Academic Search

Fossil fuels are used as raw materials for the manufacture of synthetic organic materials, e.g. plastics, fibres, synthetic rubber,\\u000a paints, solvents, fertilisers, surfactants, lubricants and bitumen. Since fossil carbon is embodied in these products they may be particularly relevant to climate change. This thesis analyses the production, use and waste management of synthetic organic\\u000a materials. The main research questions are

Martin Patel

1999-01-01

301

The Carbon Cycle  

NSDL National Science Digital Library

This online lab exercise focuses on the processes involved in the Carbon cycle and the influences of human activity on those processes- especially as they relate to Earth's weather and climate. The fourth in a 10-part lab series on weather and climate, this lab exercise is designed for first and second year college geoscience students (majors and non-majors) as well as pre-service STEM teachers.

302

CARBON DIOXIDE FIXATION.  

SciTech Connect

Solar carbon dioxide fixation offers the possibility of a renewable source of chemicals and fuels in the future. Its realization rests on future advances in the efficiency of solar energy collection and development of suitable catalysts for CO{sub 2} conversion. Recent achievements in the efficiency of solar energy conversion and in catalysis suggest that this approach holds a great deal of promise for contributing to future needs for fuels and chemicals.

FUJITA,E.

2000-01-12

303

Carbon fluxes in soil  

Microsoft Academic Search

Terrestrial ecosystems represent the second largest carbon reservoir, and the C balance in terrestrial ecosystems can be directly\\u000a impacted by human activities such as agricultural management practices and land-use changes. This paper focuses on the C-sequestration\\u000a in soil. Although many studies showed that the concentration of SOC is much higher in the shallow soils (0–30 cm), the deeper\\u000a horizons represent

John F. McCarthy

2005-01-01

304

Brominated graphitized carbon fibers  

NASA Technical Reports Server (NTRS)

Low cost, high break elongation graphitized carbon fibers having low degree of graphitization are inert to bromine at room or higher temperatures, but are brominated at -7 to 20 C, and then debrominated at ambient. Repetition of this bromination-debromination process can bring the bromine content to 18 percent. Electrical conductivity of the brominated fibers is three times of the before-bromination value.

Hung, Ching-Cheh (inventor)

1991-01-01

305

Low dimensional carbon electronics  

NASA Astrophysics Data System (ADS)

This thesis covers several different experiments that comprised my graduate career. The main focus of these experiments was the use of carbon as an electronic material and a steady evolution of fabrication recipes that allowed us to perform reliable and consistent measurements. The second chapter describes experiments with carbon nanotubes, where our goal was to produce devices capable of manipulating electronic spin states in order create quantum bits or "qubits." The third chapter covers the development of fabrication recipes with the goal of creating qubits within Si-Ge nanowire, and the bottom-gating approach that was developed. The fourth chapter begins graphene related research, describing one of the simplest uses of graphene as a simple transparent electrode on a SiN micromembrane. The remainder of the thesis describes experiments that develop graphene based optical and infrared detectors, study their characteristics and determine the physics that underlies their detection mechanism. Key in these experiments were the fabrication recipes that had been developed to create carbon nanotube and Si-Ge nanowire devices. Finally, we demonstrate how engineering of the device's thermal characteristics can lead to improved sensitivity and how graphene can be used in novel applications where conventional materials are not suitable.

Herring, Patrick Kenichi

306

Carbon taxes and India  

SciTech Connect

Using the Indian module of the Second Generation Model 9SGM, we explore a reference case and three scenarios in which greenhouse gas emissions were controlled. Two alternative policy instruments (carbon taxes and tradable permits) were analyzed to determine comparative costs of stabilizing emissions at (1) 1990 levels (the 1 X case), (2) two times the 1990 levels (the 2X case), and (3) three times the 1990 levels (the 3X case). The analysis takes into account India`s rapidly growing population and the abundance of coal and biomass relative to other fuels. We also explore the impacts of a global tradable permits market to stabilize global carbon emissions on the Indian economy under the following two emissions allowance allocation methods: (1) {open_quotes}Grandfathered emissions{close_quotes}: emissions allowances are allocated based on 1990 emissions. (2) {open_quotes}Equal per capita emissions{close_quotes}: emissions allowances are allocated based on share of global population. Tradable permits represent a lower cost method to stabilize Indian emissions than carbon taxes, i.e., global action would benefit India more than independent actions.

Fisher-Vanden, K.A.; Pitcher, H.M.; Edmonds, J.A.; Kim, S.H. [Pacific Northwest Lab., Richland, WA (United States); Shukla, P.R. [Indian Institute of Management, Ahmedabad (India)

1994-07-01

307

Carbon in primitive meteorites  

NASA Technical Reports Server (NTRS)

No meteorites are truly primitive, in the sense of being pristine collections of interstellar grains or solar-nebular condensates. Nonetheless, some chrondritic meteorites have been so little altered by secondary processing that they are commonly termed primitive and it is almost a definition of such chondrites that they contain significant quantities of carbon. Most of that carbon is of apparently local, i.e., solar-system, origin but a proportion that ranges from trace, in some cases, to minor, in others, is believed to be exotic, i.e., of circumstellar or interstellar origin, and it is upon such material that researchers focus here. The nature of the meteoritic samples and the techniques used to analyse them are briefly discussed and the observational record is surveyed. Clearly, the study of exotic carbon preserved in meteorites has been informative about sites of nucleosynthesis, processes of nucleation and growth of grains in stellar outflows, grain survival in the interstellar medium, and many other topics of astrophysical significance. Much more work, particularly of an interdisciplinary nature remains to be done, however.

Kerridge, John F.

1990-01-01

308

Carbon Dioxide Capture and Disposal  

NASA Astrophysics Data System (ADS)

Unless carbon dioxide from fossil fuel combustion is captured and disposed of safely and permanently, the concerns over climate change will eventually lead to the demise of fossil fuels. Because of their importance in today's energy market the phasing out of fossil fuels would likely precipitate a major energy crisis. Mineral sequestration and extraction of carbon dioxide from the air are two advanced technologies for carbon sequestration that aim at maintaining access to the vast fossil energy resources for centuries to come. While it is straightforward to dispose of carbon dioxide in limited amounts and for a limited time, permanent disposal of trillions of tons of carbon poses serious challenges. The formation of solid mineral carbonates from readily available minerals would provide safe and permanent storage. Capture of carbon dioxide from air makes it possible to sequester carbon dioxide emissions from sources other than power plants. This is important considering that even the relatively minor reductions suggested by the Kyoto Accord would have required the US to eliminate carbon dioxide emissions comparable to those of the entire 1990 coal fired power plant fleet. Capture of carbon dioxide from the air, would make it possible to close the carbon cycle in the transportation sector without phasing out liquid hydrocarbon fuels. It eliminates the need for long distance transport of carbon dioxide and allows the continued use of the existing energy infrastructure. Mineral sequestration at remote sites combined with on site carbon dioxide capture from air, would allow for long term stabilization of atmospheric carbon dioxide levels. I will outline the current state of the technology and point to advances required before these approaches are ready for large-scale implementation.

Lackner, K. S.

2002-05-01

309

Mass spectroscopic characterization of yttrium-containing metallofullerene YC82 using resonant laser ablation  

SciTech Connect

In this paper, resonant laser ablation time-of-flight mass spectroscopy (RLA-TOF-MS) has been used to mass spectroscopic characterization of yttrium-containing fullerenes. Solvent soluble, yttrium-containing fullerenes are extracted from yttrium/carbon soot produced by the carbon-arc fullerene generation method. The RLA-TOF mass spectra indicate the presence of YC82. The metallofullerences YC60, YC70, Y2C82 and a series of Y2C2n are not observed by RLA-TOF-MS. This result is consistent with the ESR spectral result reported by Shinohara et al.

Wang Shiliang; Tian Jiahe; Dai Songtao; Chen Dieyan; Luo Chuping; Tan Haisong; Gan Liangbing; Huang Chunhui [Laser Single Atom Detection Laboratory, Department of Physics, Tsinghua University, Beijing 100084 (China); State Key Laboratory of Rare Earth Material Chemistry and Applications, Peking University, Beijing 100871 (China)

1995-04-01

310

Carbon K-edge Spectra of Carbonate Minerals  

SciTech Connect

Carbon K-edge X-ray spectroscopy has been applied to the study of a wide range of organic samples, from polymers and coals to interstellar dust particles. Identification of carbonaceous materials within these samples is accomplished by the pattern of resonances in the 280-320 eV energy region. Carbonate minerals are often encountered in the study of natural samples, and have been identified by a distinctive resonance at 290.3 eV. Here C K-edge and Ca L-edge spectra from a range of carbonate minerals are presented. Although all carbonates exhibit a sharp 290 eV resonance, both the precise position of this resonance and the positions of other resonances vary among minerals. The relative strengths of the different carbonate resonances also vary with crystal orientation to the linearly polarized X-ray beam. Intriguingly, several carbonate minerals also exhibit a strong 288.6 eV resonance, consistent with the position of a carbonyl resonance rather than carbonate. Calcite and aragonite, although indistinguishable spectrally at the C K-edge, exhibited significantly different spectra at the Ca L-edge. The distinctive spectral fingerprints of carbonates provide an identification tool, allowing for the examination of such processes as carbon sequestration in minerals, Mn substitution in marine calcium carbonates (dolomitization) and serpentinization of basalts.

Brandes, J.; Wirick, S; Jacobsen, C

2010-01-01

311

Oxidation of Carbon/Carbon through Coating Cracks  

NASA Technical Reports Server (NTRS)

Reinforced carbon/carbon (RCC) is used to protect the wing leading edge and nose cap of the Space Shuttle Orbiter on re-entry. It is composed of a lay-up of carbon/carbon fabric protected by a SiC conversion coating. Due to the thermal expansion mismatch of the carbon/carbon and the SiC, the SiC cracks on cool-down from the processing temperature. The cracks act as pathways for oxidation of the carbon/carbon. A model for the diffusion controlled oxidation of carbon/carbon through machined slots and cracks is developed and compared to laboratory experiments. A symmetric cylindrical oxidation cavity develops under the slots, confirming diffusion control. Comparison of cross sectional dimensions as a function of oxidation time shows good agreement with the model. A second set of oxidation experiments was done with samples with only the natural craze cracks, using weight loss as an index of oxidation. The agreement of these rates with the model is quite reasonab

Jacobson, N. S.; Roth, d. J.; Rauser, R. W.; Cawley, J. D.; Curry, D. M.

2008-01-01

312

The effects of neutron irradiation on the structure of carbon-carbon composites  

SciTech Connect

In this paper irradiation behavior of carbon fibers and carbon-carbon composites are discussed in terms on simple microstructural models. Previous data are discussed in terms of these models. New data are presented for the irradiation-induced dimensional changes of selected carbon-carbon composites. The influence of fiber precursor on carbon- carbon irradiation performance is discussed.

Burchell, T.D.; Eatherly, W.P. (Oak Ridge National Lab., TN (USA)); Hollenberg, G. W.; Slagle, O.D. (Pacific Northwest Lab., Richland, WA (USA)); Watson, R.D. (Sandia National Labs., Albuquerque, NM (USA))

1991-01-01

313

Oxidative Attack of Carbon/Carbon Substrates through Coating Pinholes  

NASA Technical Reports Server (NTRS)

A critical issue with oxidation protected carbon/carbon composites used for spacecraft thermal protection is the formation of coating pinholes. In laboratory experiments, artificial pinholes were drilled through SiC-coatings on a carbon/carbon material and the material was oxidized at 600, 1000, and 1400 C at reduced pressures of air. The attack of the carbon/carbon was quantified by both weight loss and a novel cross-sectioning technique. A two-zone, one dimensional diffusion control model was adapted to analyze this problem. Agreement of the model with experiment was reasonable at 1000 and 1400 C; however results at lower temperatures show clear deviations from the theory suggesting that surface reaction control plays a role.

Jacobson, Nathan S.; Leonhardt, Todd; Curry, Donald; Rapp, Robert A.

1998-01-01

314

The Toxicology of Carbon Nanotubes  

NASA Astrophysics Data System (ADS)

1. Carbon nanotube structure, synthesis and applications C. Singh and W. Song; 2. The aerodynamic behaviour and pulmonary deposition of carbon nanotubes A. Buckley, R. Smith and R Maynard; 3. Utilising the concept of the biologically effective dose to define the particle and fibre hazards of carbon nanotubes K. Donaldson, R. Duffin, F. Murphy and C. Poland; 4. CNT, biopersistence and the fibre paradigm D. Warheit and M. DeLorme; 5. Length-dependent retention of fibres in the pleural space C. Poland, F. Murphy and K. Donaldson; 6. Experimental carcinogenicity of carbon nanotubes in the context of other fibres K. Unfried; 7. Fate and effects of carbon nanotubes following inhalation J. Ryman-Rasmussen, M. Andersen and J. Bonner; 8. Responses to pulmonary exposure to carbon nanotubes V. Castranova and R. Mercer; 9. Genotoxicity of carbon nanotubes R. Schins, C. Albrecht, K. Gerloff and D. van Berlo; 10. Carbon nanotube-cellular interactions; macrophages, epithelial and mesothelial cells V. Stone, M. Boyles, A. Kermanizadeh, J. Varet and H. Johnston; 11. Systemic health effects of carbon nanotubes following inhalation J. McDonald; 12. Dosimetry and metrology of carbon nanotubes L. Tran, L. MacCalman and R. Aitken; Index.

Donaldson, Ken; Poland, Craig; Duffin, Rodger; Bonner, James

2012-06-01

315

Reconciling biodiversity and carbon conservation.  

PubMed

Climate change is leading to the development of land-based mitigation and adaptation strategies that are likely to have substantial impacts on global biodiversity. Of these, approaches to maintain carbon within existing natural ecosystems could have particularly large benefits for biodiversity. However, the geographical distributions of terrestrial carbon stocks and biodiversity differ. Using conservation planning analyses for the New World and Britain, we conclude that a carbon-only strategy would not be effective at conserving biodiversity, as have previous studies. Nonetheless, we find that a combined carbon-biodiversity strategy could simultaneously protect 90% of carbon stocks (relative to a carbon-only conservation strategy) and > 90% of the biodiversity (relative to a biodiversity-only strategy) in both regions. This combined approach encapsulates the principle of complementarity, whereby locations that contain different sets of species are prioritised, and hence disproportionately safeguard localised species that are not protected effectively by carbon-only strategies. It is efficient because localised species are concentrated into small parts of the terrestrial land surface, whereas carbon is somewhat more evenly distributed; and carbon stocks protected in one location are equivalent to those protected elsewhere. Efficient compromises can only be achieved when biodiversity and carbon are incorporated together within a spatial planning process. PMID:23279784

Thomas, Chris D; Anderson, Barbara J; Moilanen, Atte; Eigenbrod, Felix; Heinemeyer, Andreas; Quaife, Tristan; Roy, David B; Gillings, Simon; Armsworth, Paul R; Gaston, Kevin J

2013-05-01

316

Uncovering the Neoproterozoic carbon cycle.  

PubMed

Interpretations of major climatic and biological events in Earth history are, in large part, derived from the stable carbon isotope records of carbonate rocks and sedimentary organic matter. Neoproterozoic carbonate records contain unusual and large negative isotopic anomalies within long periods (10-100 million years) characterized by ?(13)C in carbonate (?(13)C(carb)) enriched to more than +5 per mil. Classically, ?(13)C(carb) is interpreted as a metric of the relative fraction of carbon buried as organic matter in marine sediments, which can be linked to oxygen accumulation through the stoichiometry of primary production. If a change in the isotopic composition of marine dissolved inorganic carbon is responsible for these excursions, it is expected that records of ?(13)C(carb) and ?(13)C in organic carbon (?(13)C(org)) will covary, offset by the fractionation imparted by primary production. The documentation of several Neoproterozoic ?(13)C(carb) excursions that are decoupled from ?(13)C(org), however, indicates that other mechanisms may account for these excursions. Here we present ?(13)C data from Mongolia, northwest Canada and Namibia that capture multiple large-amplitude (over 10 per mil) negative carbon isotope anomalies, and use these data in a new quantitative mixing model to examine the behaviour of the Neoproterozoic carbon cycle. We find that carbonate and organic carbon isotope data from Mongolia and Canada are tightly coupled through multiple ?(13)C(carb) excursions, quantitatively ruling out previously suggested alternative explanations, such as diagenesis or the presence and terminal oxidation of a large marine dissolved organic carbon reservoir. Our data from Namibia, which do not record isotopic covariance, can be explained by simple mixing with a detrital flux of organic matter. We thus interpret ?(13)C(carb) anomalies as recording a primary perturbation to the surface carbon cycle. This interpretation requires the revisiting of models linking drastic isotope excursions to deep ocean oxygenation and the opening of environments capable of supporting animals. PMID:22388817

Johnston, D T; Macdonald, F A; Gill, B C; Hoffman, P F; Schrag, D P

2012-03-15

317

Molded Carbon–Carbon Composites Based on Microcomposite Technology  

Microsoft Academic Search

A one-step, cost-effective processing methodology based on compression molding of a mixture of graphite particles and short fibers, both coated with a soluble polyimide adhesive was developed. This technique shows a considerable potential in decreasing the complexity of the current carbon–carbon fabrication procedures. The new process eliminates additional infiltration and densification steps following the initial carbonization, which reduces the processing

Alisa Buchman; Robert G. Bryant

1999-01-01

318

Microstructural investigation of low-density carbon-carbon composites  

Microsoft Academic Search

The microstructure of low-density (0.13–0.64 Mg m-3) carbon-carbon composites was investigated using optical microscopy, scanning electron microscopy and image analysis. All samples initially contained varying proportions of rayon precursor carbon fibres, recycled fibrous material and phenolic resin precursor matrix, and were manufactured utilizing a vacuum moulding technique. Some of the composites were densified using the chemical vapour deposition (CVD) of

I. J. Davies; R. D. Rawlings

1994-01-01

319

Inhibition of catalytic oxidation of carbon\\/carbon composite materials  

Microsoft Academic Search

An investigation coupling experimental efforts with computational chemistry analysis was conducted to study the inhibition effects of phosphorous or boron on the oxidation of carbon\\/carbon composite materials catalyzed by potassium or calcium acetate (KAC or CaAC). Commercial aircraft brakes were used, which are exposed during use to K- or Ca-containing runway deicing agents. The reactivity of inhibitor-doped carbon materials was

Xianxian Wu

2002-01-01

320

Method for joining carbon-carbon composites to metals  

DOEpatents

A method for joining carbon-carbon composites to metals by brazing. Conventional brazing of recently developed carbon-bonded carbon fiber (CBCF) material to a metal substrate is limited by the tendency of the braze alloy to ``wick`` into the CBCF composite rather than to form a strong bond. The surface of the CBCF composite that is to be bonded is first sealed with a fairly dense carbonaceous layer achieved by any of several methods. The sealed surface is then brazed to the metal substrate by vacuum brazing with a Ti-Cu-Be alloy. 1 fig.

Lauf, R.J.; McMillan, A.D.; Moorhead, A.J.

1997-07-15

321

Method for joining carbon-carbon composites to metals  

DOEpatents

A method for joining carbon-carbon composites to metals by brazing. Conventional brazing of recently developed carbon-bonded carbon fiber (CBCF) material to a metal substrate is limited by the tendency of the braze alloy to "wick" into the CBCF composite rather than to form a strong bond. The surface of the CBCF composite that is to be bonded is first sealed with a fairly dense carbonaceous layer achieved by any of several methods. The sealed surface is then brazed to the metal substrate by vacuum brazing with a Ti-Cu-Be alloy.

Lauf, Robert J. (Oak Ridge, TN); McMillan, April D. (Knoxville, TN); Moorhead, Arthur J. (Knoxville, TN)

1997-01-01

322

Carbon Nanotube-Enhanced Carbon-Phenenolic Ablator Material  

NASA Technical Reports Server (NTRS)

This viewgraph presentation reviews the use of PICA (phenolic impregnated carbon ablator) as the selected material for heat shielding for future earth return vehicles. It briefly reviews the manufacturing of PICA and the advantages for the use of heat shielding, and then explains the reason for using Carbon Nanotubes to improve strength of phenolic resin that binds carbon fibers together. It reviews the work being done to create a carbon nanotube enhanced PICA. Also shown are various micrographic images of the various PICA materials.

Kikolaev, P.; Stackpoole, M.; Fan, W.; Cruden, B. A.; Waid, M.; Moloney, P.; Arepalli, S.; Arnold, J.; Partridge, H.; Yowell, L.

2006-01-01

323

Evaluation of carbon-carbon for space engine nozzle  

NASA Technical Reports Server (NTRS)

An investigation is underway to determine the suitability of carbon-carbon composite materials for lightweight nozzle extensions on the Orbit Transfer Vehicle (OTV). The best combinations of fiber precursor, matrix material, and oxidation protection coatings are being evaluated in a series of hot-fire tests in an O sub 2/H sub 2 rocket nozzle environment. Evaluation criteria include life expectancy (recession), strength to weight, producibility, maturity, and cost. A data base of carbon-carbon performance in the OTV nozzle environment will be established which may be used in designing a full-scale OTV nozzle extension.

Suhoza, J. P.; Cawood, G. W.; Cawood, G. W.; Cawood, G. W.; Cawood, G. W.; Cawood, G. W.

1986-01-01

324

Soil warming, carbon-nitrogen interactions, and forest carbon budgets.  

PubMed

Soil warming has the potential to alter both soil and plant processes that affect carbon storage in forest ecosystems. We have quantified these effects in a large, long-term (7-y) soil-warming study in a deciduous forest in New England. Soil warming has resulted in carbon losses from the soil and stimulated carbon gains in the woody tissue of trees. The warming-enhanced decay of soil organic matter also released enough additional inorganic nitrogen into the soil solution to support the observed increases in plant carbon storage. Although soil warming has resulted in a cumulative net loss of carbon from a New England forest relative to a control area over the 7-y study, the annual net losses generally decreased over time as plant carbon storage increased. In the seventh year, warming-induced soil carbon losses were almost totally compensated for by plant carbon gains in response to warming. We attribute the plant gains primarily to warming-induced increases in nitrogen availability. This study underscores the importance of incorporating carbon-nitrogen interactions in atmosphere-ocean-land earth system models to accurately simulate land feedbacks to the climate system. PMID:21606374

Melillo, Jerry M; Butler, Sarah; Johnson, Jennifer; Mohan, Jacqueline; Steudler, Paul; Lux, Heidi; Burrows, Elizabeth; Bowles, Francis; Smith, Rose; Scott, Lindsay; Vario, Chelsea; Hill, Troy; Burton, Andrew; Zhou, Yu-Mei; Tang, Jim

2011-06-01

325

Soil warming, carbon-nitrogen interactions, and forest carbon budgets  

PubMed Central

Soil warming has the potential to alter both soil and plant processes that affect carbon storage in forest ecosystems. We have quantified these effects in a large, long-term (7-y) soil-warming study in a deciduous forest in New England. Soil warming has resulted in carbon losses from the soil and stimulated carbon gains in the woody tissue of trees. The warming-enhanced decay of soil organic matter also released enough additional inorganic nitrogen into the soil solution to support the observed increases in plant carbon storage. Although soil warming has resulted in a cumulative net loss of carbon from a New England forest relative to a control area over the 7-y study, the annual net losses generally decreased over time as plant carbon storage increased. In the seventh year, warming-induced soil carbon losses were almost totally compensated for by plant carbon gains in response to warming. We attribute the plant gains primarily to warming-induced increases in nitrogen availability. This study underscores the importance of incorporating carbon–nitrogen interactions in atmosphere–ocean–land earth system models to accurately simulate land feedbacks to the climate system. PMID:21606374

Melillo, Jerry M.; Butler, Sarah; Johnson, Jennifer; Mohan, Jacqueline; Steudler, Paul; Lux, Heidi; Burrows, Elizabeth; Bowles, Francis; Smith, Rose; Scott, Lindsay; Vario, Chelsea; Hill, Troy; Burton, Andrew; Zhou, Yu-Mei; Tang, Jim

2011-01-01

326

Novel carbon-carbon bond formations for biocatalysis  

PubMed Central

Carbon–carbon bond formation is the key transformation in organic synthesis to set up the carbon backbone of organic molecules. However, only a limited number of enzymatic C–C bond forming reactions have been applied in biocatalytic organic synthesis. Recently, further name reactions have been accomplished for the first time employing enzymes on a preparative scale, for instance the Stetter and Pictet–Spengler reaction or oxidative C–C bond formation. Furthermore, novel enzymatic C–C bond forming reactions have been identified like benzylation of aromatics, intermolecular Diels-Alder or reductive coupling of carbon monoxide. PMID:21354781

Resch, Verena; Schrittwieser, Joerg H; Siirola, Elina; Kroutil, Wolfgang

2011-01-01

327

Carbon-hydrogen bonding in near-frictionless carbon.  

SciTech Connect

The uniquely low friction behavior of near-frictionless carbon (NFC) as compared to conventional diamondlike carbon (DLC) is determined by the bonding within the film. Inelastic neutron scattering (INS) and Fourier transform infrared (FTIR) spectroscopy were used to probe the bonding environment of carbon and hydrogen; both INS and FTIR can probe the whole sample. Previous work has focused on surface studies; the present results show that in the film as a whole the majority of the hydrogen is adjacent to sp{sup 3}-bonded carbon. In addition this work has determined the absence of any molecular hydrogen in NFC.

Johnson, J. A.; Woodford, J. B.; Rajput, D.; Kolesnikov, A. I.; Schleuter, J. A.; Eryilmaz, O. L.; Erdemir, A.; Univ. of Tennessee Space Inst.; ORNL

2008-01-01

328

Geologic Carbon Sequestration and Biosequestration (Carbon Cycle 2.0)  

ScienceCinema

Don DePaolo, Director of LBNL's Earth Sciences Division, speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 3, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

DePaolo, Don [Director, LBNL Earth Sciences Division

2011-06-08

329

Geologic Carbon Sequestration and Biosequestration (Carbon Cycle 2.0)  

SciTech Connect

Don DePaolo, Director of LBNL's Earth Sciences Division, speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 3, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

DePaolo, Don [Director, LBNL Earth Sciences Division] [Director, LBNL Earth Sciences Division

2010-02-03

330

Carbon-hydrogen bonding in near-frictionless carbon  

NASA Astrophysics Data System (ADS)

The uniquely low friction behavior of near-frictionless carbon (NFC) as compared to conventional diamondlike carbon (DLC) is determined by the bonding within the film. Inelastic neutron scattering (INS) and Fourier transform infrared (FTIR) spectroscopy were used to probe the bonding environment of carbon and hydrogen; both INS and FTIR can probe the whole sample. Previous work has focused on surface studies; the present results show that in the film as a whole the majority of the hydrogen is adjacent to sp3-bonded carbon. In addition this work has determined the absence of any molecular hydrogen in NFC.

Johnson, J. A.; Woodford, J. B.; Rajput, D.; Kolesnikov, A. I.; Schleuter, J. A.; Eryilmaz, O. L.; Erdemir, A.

2008-09-01

331

Single-walled carbon nanotubes growing radially from YC2 particles  

NASA Astrophysics Data System (ADS)

In the primary soot produced by arc discharge using an yttrium carbide loaded anode, bundles of single-walled carbon nanotubes (SWT) are observed, protruding radially from YC2 particles coated with graphitic multilayers. The graphitic cages separating YC2 particle and SWT bundles fall into the narrow range of 10-20 layers. The morphology of the clusters suggests a two-step growth model: The radial SWT growth pattern is first initiated by catalytic action between the YC2 droplet and the carbon in the gas phase. Second, and upon cooling, the graphitic cage starts by segregating excess carbon from the YC2 bulk, arresting further growth of SWT.

Zhou, Dan; Seraphin, Supapan; Wang, Su

1994-09-01

332

Radiocarbon dating of terrestrial carbonates  

USGS Publications Warehouse

Terrestrial carbonates encompass a wide range of materials that potentially could be used for radiocarbon (14C) dating. Biogenic carbonates, including shells and tests of terrestrial and aquatic gastropods, bivalves, ostracodes, and foraminifera, are preserved in a variety of late Quaternary deposits and may be suitable for 14C dating. Primary calcareous deposits (marls, tufa, speleothems) and secondary carbonates (rhizoliths, fracture fill, soil carbonate) may also be targeted for dating when conditions are favorable. This chapter discusses issues that are commonly encountered in 14C dating of terrestrial carbonates, including isotopic disequilibrium and open-system behavior, as well as methods used to determine the reliability of ages derived from these materials. Recent methodological advancements that may improve the accuracy and precision of 14C ages of terrestrial carbonates are also highlighted.

Pigati, Jeffrey S.

2014-01-01

333

Carbonate fuel cell anodes  

DOEpatents

A molten alkali metal carbonates fuel cell porous anode of lithium ferrite and a metal or metal alloy of nickel, cobalt, nickel/iron, cobalt/iron, nickel/iron/aluminum, cobalt/iron/aluminum and mixtures thereof wherein the total iron content including ferrite and iron of the composite is about 25 to about 80 percent, based upon the total anode, provided aluminum when present is less than about 5 weight percent of the anode. A process is described for production of the lithium ferrite containing anode by slipcasting.

Donado, R.A.; Hrdina, K.E.; Remick, R.J.

1993-04-27

334

Carbonate fuel cell anodes  

DOEpatents

A molten alkali metal carbonates fuel cell porous anode of lithium ferrite and a metal or metal alloy of nickel, cobalt, nickel/iron, cobalt/iron, nickel/iron/aluminum, cobalt/iron/aluminum and mixtures thereof wherein the total iron content including ferrite and iron of the composite is about 25 to about 80 percent, based upon the total anode, provided aluminum when present is less than about 5 weight percent of the anode. A process for production of the lithium ferrite containing anode by slipcasting.

Donado, Rafael A. (Chicago, IL); Hrdina, Kenneth E. (Glenview, IL); Remick, Robert J. (Bolingbrook, IL)

1993-01-01

335

Platinum carbon nanotube interaction  

NASA Astrophysics Data System (ADS)

The interaction between evaporated Pt and pristine or oxygen-plasma-treated multiwall carbon nanotubes (CNTs) is investigated. Pt is found to nucleate at defect sites, whether initially present or introduced by oxygen plasma treatment. The plasma treatment induces a uniform dispersion of Pt nanoparticles at the CNT surface. The absence of additional features in the C 1 s core level spectrum indicates that no mixed Pt-C phase is formed. The formation of C-O-Pt bonds at the cluster-CNT interface is suggested to reduce the electronic interaction between Pt nanoparticles and the CNT surface.

Bittencourt, C.; Hecq, M.; Felten, A.; Pireaux, J. J.; Ghijsen, J.; Felicissimo, M. P.; Rudolf, P.; Drube, W.; Ke, X.; Van Tendeloo, G.

2008-09-01

336

Global carbon budget 2014  

NASA Astrophysics Data System (ADS)

Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe datasets and a methodology to quantify all major components of the global carbon budget, including their uncertainties, based on the combination of a range of data, algorithms, statistics and model estimates and their interpretation by a broad scientific community. We discuss changes compared to previous estimates, consistency within and among components, alongside methodology and data limitations. CO2 emissions from fossil fuel combustion and cement production (EFF) are based on energy statistics and cement production data, respectively, while emissions from Land-Use Change (ELUC), mainly deforestation, are based on combined evidence from land-cover change data, fire activity associated with deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the annual changes in concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. The variability in SOCEAN is evaluated with data products based on surveys of ocean CO2 measurements. The global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms of the global carbon budget and compared to results of independent Dynamic Global Vegetation Models forced by observed climate, CO2 and land cover change (some including nitrogen-carbon interactions). We compare the variability and mean land and ocean fluxes to estimates from three atmospheric inverse methods for three broad latitude bands. All uncertainties are reported as ±1?, reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. For the last decade available (2004-2013), EFF was 8.9 ± 0.4 GtC yr-1, ELUC 0.9 ± 0.5 GtC yr-1, GATM 4.3 ± 0.1 GtC yr-1, SOCEAN 2.6 ± 0.5 GtC yr-1, and SLAND 2.9 ± 0.8 GtC yr-1. For year 2013 alone, EFF grew to 9.9 ± 0.5 GtC yr-1, 2.3% above 2012, contining the growth trend in these emissions. ELUC was 0.9 ± 0.5 GtC yr-1, GATM was 5.4 ± 0.2 GtC yr-1, SOCEAN was 2.9 ± 0.5 GtC yr-1 and SLAND was 2.5 ± 0.9 GtC yr-1. GATM was high in 2013 reflecting a steady increase in EFF and smaller and opposite changes between SOCEAN and SLAND compared to the past decade (2004-2013). The global atmospheric CO2 concentration reached 395.31 ± 0.10 ppm averaged over 2013. We estimate that EFF will increase by 2.5% (1.3-3.5%) to 10.1 ± 0.6 GtC in 2014 (37.0 ± 2.2 GtCO2 yr-1), 65% above emissions in 1990, based on projections of World Gross Domestic Product and recent changes in the carbon intensity of the economy. From this projection of EFF and assumed constant ELUC for 2014, cumulative emissions of CO2 will reach about 545 ± 55 GtC (2000 ± 200 GtCO2) for 1870-2014, about 75% from EFF and 25% from ELUC. This paper documents changes in the methods and datasets used in this new carbon budget compared with previous publications of this living dataset (Le Quéré et al., 2013, 2014). All observations presented here can be downloaded from the Carbon Dioxide Information Analysis Center (doi:10.3334/CDIAC/GCP_2014). Italic font highlights significant methodological changes and results compared to the Le Quéré et al. (2014) manuscript that accompanies the previous version of this living data.

Le Quéré, C.; Moriarty, R.; Andrew, R. M.; Peters, G. P.; Ciais, P.; Friedlingstein, P.; Jones, S. D.; Sitch, S.; Tans, P.; Arneth, A.; Boden, T. A.; Bopp, L.; Bozec, Y.; Canadell, J. G.; Chevallier, F.; Cosca, C. E.; Harris, I.; Hoppema, M.; Houghton, R. A.; House, J. I.; Jain, A.; Johannessen, T.; Kato, E.; Keeling, R. F.; Kitidis, V.; Klein Goldewijk, K.; Koven, C.; Landa, C. S.; Landschützer, P.; Lenton, A.; Lima, I. D.; Marland, G.; Mathis, J. T.; Metzl, N.; Nojiri, Y.; Olsen, A.; Ono, T.; Peters, W.; Pfeil, B.; Poulter, B.; Raupach, M. R.; Regnier, P.; Rödenbeck, C.; Saito, S.; Salisbury, J. E.; Schuster, U.; Schwinger, J.; Séférian, R.; Segschneider, J.; Steinhoff, T.; Stocker, B. D.; Sutton, A. J.; Takahashi, T.; Tilbrook, B.; van der Werf, G. R.; Viovy, N.; Wang, Y.-P.; Wanninkhof, R.; Wiltshire, A.; Zeng, N.

2014-09-01

337

Carbon nanotubes: biomaterial applications.  

PubMed

There is increasing interest in the unique biological and medical properties of carbon nanotubes (CNTs), and it is expected that biomaterials incorporating CNTs will be developed for clinical use. There has been a great deal of progress in improving the various properties of CNTs for use in biomaterials and for promotion of tissue regeneration as scaffold materials. The effects of CNTs on cells and tissues are extremely important for their use in biomaterials. This tutorial review clarifies the current state of knowledge in the interdisciplinary field of CNT-based nanobiotechnology to determine whether CNTs may be useful in biomaterials. Future perspectives in this rapidly developing field will also be discussed. PMID:19551170

Saito, Naoto; Usui, Yuki; Aoki, Kaoru; Narita, Nobuyo; Shimizu, Masayuki; Hara, Kazuo; Ogiwara, Nobuhide; Nakamura, Koichi; Ishigaki, Norio; Kato, Hiroyuki; Taruta, Seiichi; Endo, Morinobu

2009-07-01

338

Carbon Dioxide Production at Home  

NSDL National Science Digital Library

In this problem set, learners will consider the "Carbon Footprint" of a family of four in a given context, as well as the US and global averages, and compare that with their own to answer a series of questions. They will use an online Carbon Footprint calculator to determine their own per-capita carbon production. Answer key is provided. This problem is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

339

Carbon dioxide affects global ecology  

Microsoft Academic Search

Man's activities are changing the carbon dioxide and oxygen content of the entire atmosphere. These changes may, in turn, affect worldwide weather and the growth of plants. Under normal conditions, the amounts of carbon dioxide and oxygen in the atmosphere remain approximately in equilibrium on a year-to-year basis. The atmosphere today contains about 21% oxygen and about 0.032% carbon dioxide

Eugene K. Peterson

1969-01-01

340

What is the Carbon Cycle?  

NSDL National Science Digital Library

This activity has students explore the carbon cycle and learn to identify carbon sources, sinks, and release agents. They will come to understand that carbon is critical to the biosphere and must continue cycling to support life on earth. The instructor guide contains detailed background material, learning goals, alignment to national standards, grade level/time, details on materials and preparation, procedure, assessment ideas, and modifications for alternative learners.

2007-12-12

341

Plasma patterning of carbon nanotubes  

Microsoft Academic Search

We have prepared micropatterns of carbon nanotubes on a wide range of substrates either by patterned growth of aligned nanotubes on surfaces prepatterned with plasma polymers (e.g., n-hexane plasma polymer) or through region-specific adsorption of certain chemically modified carbon nanotubes (e.g., -COOH substituted nanotubes) onto surfaces prepatterned with various plasma-generated functionalities (e.g., -NH2). Micropatterns of carbon nanotubes prepared in both

Qidao Chen; Liming Dai

2000-01-01

342

Conservation tillage for carbon sequestration  

Microsoft Academic Search

World soils represent the largest terrestrial pool of organic carbon (C), about 1550 Pg compared with about 700 Pg in the\\u000a atmosphere and 600 Pg in land biota. Agricultural activities (e.g., deforestation, burning, plowing, intensive grazing) contribute\\u000a considerably to the atmospheric pool. Expansion of agriculture may have contributed substantially to the atmospheric carbon\\u000a pool. However, the exact magnitude of carbon

R. Lal; J. M. Kimble

1997-01-01

343

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

E-print Network

of carbon dioxide by the burning of fossil fuels ( 6 billion tons of carbon per year). Possible shiftsModel-based estimation of the global carbon budget and its uncertainty from carbon dioxide, balancing emissions from fossil fuel and land use with carbon uptake by the oceans, and the terrestrial

Jain, Atul K.

344

Inelastic neutron scattering from carbon, iron, yttrium and lead  

NASA Astrophysics Data System (ADS)

Double-differential cross sections and angular distributions of inelastic neutron scattering on 12C, 56Fe, 89Y and 208Pb have been measured at 96 MeV at The Svedberg Laboratory, Uppsala, Sweden. Results on elastic neutron scattering at 96 MeV from these nuclei have been reported previously [1-3]. To obtain the inelastic cross sections, a forward-folding technique has been applied. A physically reasonable trial spectrum has been folded with the response function of the detector system and the output has been compared with the experimental data. To create the trial spectrum, a Gaussian has been used for the elastic part and the PRECO code [4-7] for the inelastic part. Other models were tested for the pre-equilibrium contribution and the method was found to be model independent. The response function of the detector setup has been obtained experimentally at the smallest possible angle, in this case at 9 deg. The resulting preliminary inelastic scattering data cover an excitation energy range up to 45 MeV and the angular intervals 28 to 58 degrees for 12C, 26 to 65 degrees for 56Fe and 26 to 52 degrees for 89Y and 208Pb. The preliminary results are discussed and compared to several model codes as well as existing experimental data for (n,n'x), (n,p'x) and (p,p'x). Possible improvements of the analysis are also discussed.

Gustavsson, Cecilia; Blomgren, Jan; Hellesen, Carl; Öhrn, Angelica; Pomp, Stephan

2012-02-01

345

The Carbon Cycle Science Program  

NSDL National Science Digital Library

The US Global Change Research Program (USGCRP) provides this site with the purpose of supplying "critical unbiased scientific information on the fate of carbon dioxide in the environment to contribute to the ongoing public dialogue." The USGCRP's focus for the fiscal year 2000 is on determining the location, magnitude, and use of carbon sinks in North America. Sections of the site include Current Research Activities, Contacts, Program and Science Planning, and Meetings and Workshops. Users can download The Carbon Cycle Science Plan in .pdf format and also obtain specific, current information on the background and goals of the Carbon Cycle Science Program initiative.

346

Improving Spectrophotometric Carbon System Measurements.  

E-print Network

??This work provides improved procedures for spectrophotometric carbon system measurements. Indicator dyes used for routine spectrophotometric pH measurements in seawater suffer from impurity issues, which… (more)

Patsavas, Mark

2014-01-01

347

Carbon-assisted flyer plates  

DOEpatents

A laser driven flyer plate utilizing an optical fiber connected to a laser. The end of the optical fiber has a layer of carbon and a metal layer deposited onto it. The carbon layer provides the laser induced plasma which is superior to the plasma produced from most metals. The carbon layer plasma is capable of providing a flatter flyer plate, converting more of the laser energy to driving plasma, promoting a higher flyer plate acceleration, and providing a more uniform pulse behind the plate. In another embodiment, the laser is in optical communication with a substrate onto which a layer of carbon and a layer of metal have been deposited.

Stahl, David B. (Los Alamos, NM); Paisley, Dennis L. (Santa Fe, NM)

1994-01-01

348

Carbon Cycling in Northern Peatlands  

NASA Astrophysics Data System (ADS)

Northern peatlands span only 3 million square kilometers, about 3% of the terrestrial area of the globe, yet they represent a significant terrestrial sink for carbon dioxide. They are also important emitters of methane, an even more potent greenhouse gas. Despite their substantial role in the global carbon cycle, peatlands are not typically incorporated into global climate models. The AGU Monograph Carbon Cycling in Northern Peatlands, edited by Andrew J. Baird, Lisa R. Belyea, Xavier Comas, A. S. Reeve, and Lee D. Slater, looks at the disproportionate role peatlands play in the global carbon budget. In this interview, Eos talks with Andy Baird, University of Leeds, Leeds, United Kingdom.

Schultz, Colin

2010-11-01

349

Amorphous carbons and extinction curve  

NASA Astrophysics Data System (ADS)

All forms of carbonaceous matter are supposed to be originated from amorphous carbon in the interstellar medium (ISM). In a search for the proper kind of amorphous carbon suitable for ISM particles, a theoretical study of wavelength extinction profiles along peculiar sightlines is performed. We consider nanodiamond core with mantle made of various amorphous carbon models. The study concludes that the extinction curves along different sightlines need different amorphous carbons to compare well with the observational data, whereas a same dust-particle formation process is consistent with all the data, whatever the sightline.

Rai, Rakesh K.; Botet, Robert S.

2014-10-01

350

Carbon dioxide and climate  

NASA Astrophysics Data System (ADS)

The earth's climate is getting warmer because of a buildup of carbon dioxide in the atmosphere that will continue well into the next century, according to a report released October 20 by the National Research Council (NRC), the research arm of the National Academy of Sciences. As the result of a 2-year study commissioned by Congress, the NRC's Carbon Dioxide Assessment Committee predicts a global temperature rise of as much as 4.5°C by the year 2100, enough to shift weather patterns, raise sea levels, and eliminate agriculture in some parts of the world. What's more, the trend seems inevitable— even drastic changes in our energy use would not prevent the warmup, according to the committee's findings.CO2, the major contributor to a thermal “greenhouse effect” that traps re-radiated heat in the atmosphere, has risen from a concentration of 315 parts per million (ppm) to 340 ppm in one generation, largely as a result of the use of fossil fuels. Sometime in the third quarter of the next century, the report predicts, the concentration will probably be double the current level. The result will be a global warming of surface air of between 1.5° and 4.5°C, with temperature rises relatively greater at the poles.

351

Nanofabrication of carbon materials  

NASA Astrophysics Data System (ADS)

We demonstrate a process for fabrication of nanostructures on the surfaces of highly oriented pyrolytic graphite (HOPG) and glassy carbon (GC) samples. Using hole-mask colloidal lithography (HCL), nanosized etch masks with three different feature diameters were prepared by identical processes on each of the two surface types. Oxygen reactive ion etching (RIE) was then used to transfer the mask pattern onto the surfaces. The structures were characterized using atomic force- (AFM), scanning electron microscopy (SEM) and optical spectrophotometry. The identical preparation schemes applied to the two materials yield structures with remarkably different shape and sizes. For example the process that yields 361 nm high and 37 nm diameter structures on glassy carbon yields 120 nm high and 119 nm diameter structures on HOPG. In general, the diameters of the fabricated GC nano-features are always at least 80 nm smaller than those of the corresponding HOPG structures, and the GC structure heights are more than three times that of the HOPG structures. These differences are attributed to different (an)isotropic etching behavior of the two materials.

Chakarov, Dinko; Fredriksson, Hans; Kasemo, Bengt

2008-03-01

352

Carbon fiber modification  

NASA Technical Reports Server (NTRS)

The effect of several chemical treatments on the electrical and mechanical properties of carbon fibers was investigated with an optimum goal of increasing the electrical resistivity by a factor of 1000 without appreciably changing the mechanical properties. It was possible to effect resistivity increases from 10 to 50 percent without adversely affecting the tensile strength or Young's modulus for T-300 and C-6000 PAN fibers by treatments with either AlCl3 or nitric acid mixtures. Larger increases in the resistivity were produced with pitch fibers treated with nitric acid mixtures. This treatment also produced a partial decomposition of the pitch fiber and deterioration of the mechanical properties. The rationale behind the approch was to immobilize the conductivity producing pi electrons in the microscopic aromatic structure of the carbon fibers without destroying the strength producing sigma bonds. The investigations indicate that certain chemical treatments can produce such results, but the total reduction in the electrical conductivity which was achieved was not large enough to impact on problems which might arise from the high conductivities of the fibers.

Thompson, T. E.

1979-01-01

353

[Unusual carbon monoxide poisoning].  

PubMed

Despite of indicative death scenes or characteristic findings of the external examination, about 40% of the accidental fatal intoxications due to carbon monoxide are not recognized before the performance of the autopsy. Six cases are reported which illustrate possible reasons for the delayed establishment of the diagnosis: unusual circumstances of the intoxication or sources of carbon monoxide, only subtle degree or lack of external signs of the intoxication or a competing cause of death at autopsy.--Cases 1 and 2: 53, respectively 54-year-old couple, found dead in a caravan, extreme putrefaction of the bodies, spectrophotometric detection of the fatal carboxyhaemoglobin level in oedema fluid of the scalp.--Case 3: 23-year-old lorry driver, found dead in the tightly closed cab of his lorry, operation of a source of electricity with "environmentally friendly" fuel, carboxyhaemoglobin level 83%.--Case 4: 19-year-old man, found dead in the flat of friends, removal of the CO-source before alerting the police forces, lack of the bright pink coloration of livor mortis, haemopericardium due to atrial rupture at postmortem examination, carboxyhaemoglobin level 65%.--Case 5: 27-year-old man, found dead in his flat, advanced decomposition of the body, residues of a charcoal fire in a metal bucket in the sink, carboxyhaemoglobin level 80%.--Case 6: 42-year-old woman, lying dead in the garage beside her car, engine switched-off, ignition key next to the body on the floor under the car, carboxyhaemoglobin level 46%. PMID:11591055

Schmidt, P; Musshoff, F; Dettmeyer, R; Madea, B

2001-01-01

354

[Carbon monoxide poisoning].  

PubMed

Carbon monoxide (CO) is a product of incomplete burning of coals and carbon compounds and is a gas without any typical taste, colour or smell. Defective radiators or gas pipes, open fireplaces, fires and explosions are sources of unintended CO production and inhalation. CO bonds with haemoglobin much more readily than oxygen does. CO toxicity causes impaired oxygen delivery and utilisation at cellular level. It affects different sites within the body, but has its most profound impact on the organs with the highest oxygen requirement. CO concentration and the intensity and duration of inhalation determine the extent of intoxication. Following basic life support, assisted or controlled ventilation with 100% oxygen is essential during emergency care. Hyperbaric oxygenation (HBO) is the preferred therapeutic option for releasing CO from its binding to haemoglobin. It has been shown that CO may cause lipid peroxidation and leukocyte-mediated inflammatory changes in the brain, a process that may be inhibited by HBO. Patients with neurological symptoms including loss of consciousness and expectant mothers should undergo HBO treatment, no matter how high their CO levels are. Neonates and in-utero fetuses are more vulnerable due to the natural leftward shift of the dissociation curve of fetal haemoglobin, a lower baseline pO2 and carboxyhaemoglobin levels at equilibration that are 10-15% higher than maternal levels. Physicians need to be aware of the potential occurrence of this life threatening hazard so that appropriate emergency treatment can be administered and fatalities prevented. PMID:10920484

Jaeger, K; Ruschulte, H; Heine, J; Piepenbrock, S

2000-01-01

355

Introduction to Carbonate Equilibrium  

NSDL National Science Digital Library

The activity asks students to make observations about what occurs when two effervescent antacid tablets are placed into a beaker of water. The Students work together in groups. There are three parts to the activity. In the first part, the tablets are dropped into tap water and student groups (2-4 students) must complete a series of question sheets (one per group) that guide them through thinking about the event. In the second part, a presentation on chemical equilibrium for the carbonate system is given. The starting point is the answers received in the first part. Basic chemical reactions for the carbonate system are presented including equilibrium expressions for each reaction and discussion about open and closed systems. At the end of class, a handout is given to the students. In the third part, three beakers (acidic, neutral and basic solutions, but not indicated) are placed together and two tablets are placed into each beaker. Students are split into two groups (8-12 students) and are asked to describe why the reactions are different. Discussion follows collection of student responses in each part. Once the chemical reactions and equilibrium expressions are presented, they are involved and referenced in all discussions.

Stapleton, Michael

356

Refractory Oxidative-Resistant Ceramic Carbon Insulation  

NASA Technical Reports Server (NTRS)

High-temperature, lightweight, ceramic carbon insulation is prepared by coating or impregnating a porous carbon substrate with a siloxane gel derived from the reaction of an organodialkoxy silane and an organotrialkoxy silane in an acid or base medium in the presence of the carbon substrate. The siloxane gel is subsequently dried on the carbon substrate to form a ceramic carbon precursor. The carbon precursor is pyrolyzed, in an inert atmosphere, to form the ceramic insulation containing carbon, silicon, and oxygen. The carbon insulation is characterized as a porous, fibrous, carbon ceramic tile which is particularly useful as lightweight tiles for spacecraft.

Leiser, Daniel B. (Inventor); Hsu, Ming-Ta S. (Inventor); Chen, Timothy S. (Inventor)

2001-01-01

357

Carbon Cloth Reinforced Carbon Aerogel Films Derived from Resorcinol Formaldehyde  

Microsoft Academic Search

Carbon cloth reinforced RF (Resorcinol Formaldehyde) aerogel films have been produced with extremely high RC ratio (molar ratio of resorcinol to catalyst) or with no catalyst at all. The gels were subcritically dried. Carbon aerogel films were obtained by pyrolysis of the RF aerogel films. The structure of the composite porous films was investigated using infrared spectrometer, optical and electron

J. Wang; M. Glora; R. Petricevic; R. Saliger; H. Proebstle; J. Fricke

2001-01-01

358

Role of activated carbon pellets in carbon dioxide removal  

Microsoft Academic Search

The removal of carbon dioxide from gas\\/air streams is more often becoming necessary in many industries for different purposes. In cryogenic air separation plant, air has to be free from carbon dioxide before its liquefaction otherwise blockage due to freezing of heat exchange equipment would result. Enrichment of methane in biogas to have fuel of higher calorific value can be

S. C Sarkar; A Bose

1997-01-01

359

Carbon sequestration and its role in the global carbon cycle  

Microsoft Academic Search

The science of climate change, and the role carbon dioxide (CO2) plays in it, was launched into the public consciousness by Charles David Keeling's investigations in the late 1950s. Keeling conducted early atmospheric carbon measurements high on Hawaii's Mauna Loa volcano and found that even after ruling out natural fluctuations, the concentration of CO2 in the atmosphere was increasing year

Colin Schultz

2011-01-01

360

SCALE-UP OF CARBON /CARBON BIPOLAR PLATES  

E-print Network

production #12;PHASE II ACTIVITIES AND TIMELINE Scale-up of Carbon/Carbon Bipolar Plates · Overview of Phase ­ Perform cost analysis on plates produced with this facility and project costs to higher volume production line capability through production metrics ­ Demonstrate 5000 hour plate operation with minimal

361

Carbon isotope geochemistry of the Precambrian Lomagundi carbonate province, Rhodesia  

Microsoft Academic Search

Carbon isotope measurements carried out on 67 dolomite samples from the Middle Precambrian Lomagundi Group (Rhodesia) have yielded a 13 C mean of +8.2 ± 2.6%. vs PDB. With the outcrop of these dolomites extending over a distance of almost 300 km, the Lomagundi dolomite faces is likely to represent the largest isotopically anomalous sedimentary carbonate province ever recorded. It

Manfred Schidlowski; Rudolf Eichmann; Christian E. Junge

1976-01-01

362

Multilayered coatings for protecting carbon-carbon composites from oxidation  

Microsoft Academic Search

Two multilayered coatings were designed for protecting a 2D carbon-carbon composite material from oxidation in a particular application. The principles of coating design are presented and the results obtained indicate that the protective effect met the predetermined requirements. It is concluded that a desirable coating should be a glass material, insensitive to moisture, which has a compositional gradient.

Meili Guo; Kui Shen; Yudong Zheng

1995-01-01

363

Oxidation behaviour and protection of carbon\\/carbon composites  

Microsoft Academic Search

The oxidation behaviour of carbon\\/carbon composite materials and graphite (in cube form), in flowing air, has been studied in the temperature range 500 to 1100 °C. Gasification for unprotected samples occurred at temperatures around 500 °C. SiC coatings offered only limited protection below their intrinsic protection range due to the diffusion of oxygen along microcracks. Diffusional control was more significant

S. M. Gee; J. A. Little

1991-01-01

364

Cumulative Carbon and Just Allocation of the Global Carbon Commons  

E-print Network

in the atmosphere causes global warming and other forms of climate disruption, while that portion that enters--notably methane--also contribute to global warming, but these do not merit consideration on an equal footingCumulative Carbon and Just Allocation of the Global Carbon Commons R.T. Pierrehumbert1

Pierrehumbert, Raymond

365

Eddy current testing of carbon-carbon composites  

Microsoft Academic Search

A noncontact electromagnetic measuring system for conductivity monitoring in carbon-carbon composites and similar refractory materials at elevated temperatures is demonstrated. It was verified in the case of thin sheets of test material that the frequency of the peak eddy current dissipation was inversely proportional to the product of the thickness and conductivity. Hysteresis on heating and cooling was noted to

M. Gvishi; A. H. Kahn; M. L. Mester

1992-01-01

366

Effects of Porosity on Strength of Carbon-Carbon Composites  

Microsoft Academic Search

Filament wound\\/CVD (Chemical Vapor Deposition) carbon-carbon composites have received considerable attention and application within the past few years because of their desirable characteristics such as high heat of ablation, thermal shock resistance, high strength at elevated temperatures, and chemical inertness. However, poor mechanical properties in the transverse direction have hampered the total effectiveness of these composites in some applications and

Gilbert William Brassell; James A. Horak; Barry Lynn Butler

1975-01-01

367

Three-dimensional helical carbon materials: Microcoiled carbon fibers, carbon nanocoils, carbon nanotubes: Synthesis, properties and applications  

NASA Astrophysics Data System (ADS)

Materials with a 3D-helical/spiral-structure in micron size have recently aroused a great deal of interests because of their helical morphology and unique properties. However, materials with a 3D helical structure are not commonly observed among industrially available materials. Researchers have been trying to synthesize various micro- and nano-sized 3D helical materials and are exploring the mechanisms, nature, and properties of these materials. Yet a systematic study on 3D helical carbon materials in micro- and nano-size has been missing. This research work is intended as a first step to fill this gap. Among various 3D helical materials, carbon element has stimulated great interests. Micro coiled carbon fibers, carbon nanocoils, and carbon nanotubes are major types of 3D helical carbon materials ranging from micron to nano size. Synthesis of these 3D helical carbon materials by a catalytic chemical vapor deposition method is presented in this thesis. It involves a pyrolysis of hydrocarbon gas (e.g. acetylene) over transition metals, such as Ni, Fe, and Co, at high reaction temperature (500--1000°C). Besides the conventional thermal filament chemical vapor deposition method, a novel microwave chemical vapor deposition (MWCVD) method has been developed to synthesize micro- and nano-sized 3D helical carbon materials economically. The faster heating and cooling processes associated with microwave CVD have potential for large-scale production in the near future. Compared with previously reported microwave plasma enhanced chemical vapor deposition (MWPECVD) method, this method does not require high vacuum and much higher deposition rate is another major advantage. It has been found in this work that microwave plays an important role on coil morphology formation for micro coiled carbon fibers and carbon nanocoils. The large temperature gradient around the catalytic particles could be the reason. Different reaction factors have been checked to optimize the deposition. Due to their extraordinary properties, carbon nanotubes have been expected to have wide applications. Efforts have been made on the synthesis of high quality carbon nanotubes economically in this work. A novel catalyst/catalyst support pair, iron/magnesium carbonate, has been developed for synthesis of multi-walled carbon nanotubes with high purity. The coil morphology is induced by insertion of pentagon-heptagon pairs into hexagonal network of nanotube wall periodically. Thorough purification of carbon nanotubes is always a concern before investigating their properties and potential applications. Impurities in raw carbon nanotube material have to be removed by chemical treatment. A couple of purification methods are presented in this work. Various techniques have been used to characterize these micro- and nano-3D materials, such as scanning electron microscopy (SEM), energy dispersive spectrum (EDS), transmission electron microscopy (TEM), X-ray diffraction (XRD), Brunauer Emmett-Teller (BET), thermal gravimetric analysis (TGA), etc. Growth mechanisms are proposed based on the experimental and characterization results. It is verified that the nonuniform carbon deposition rate on catalyst particles leads to the bending of the carbon fiber/tubule, and hence results in the coil morphology. To conclude, the research work reported here is a systematic study on synthesis, characterizations, and applications of micro- and nano-3D helical carbon materials, such as micro coiled carbon fibers, carbon nanocoils and carbon nanotubes. A few suggestions for future research directions are also listed.

Xie, Jining

368

CARBON DIOXIDE AND OUR OCEAN LEGACY  

E-print Network

of carbon dioxide from the atmosphere, or nearly half of the fossil fuel carbon emissions over this periodCARBON DIOXIDE AND OUR OCEAN LEGACY G Carbon Dioxide: Our Role The United States is the single. Every day the average American adds about 118 pounds of carbon dioxide to the atmos- phere, due largely

369

University of Aberdeen Carbon Management Plan  

E-print Network

of Aberdeen is committed to reducing its carbon footprint and to playing its part in limiting the worstUniversity of Aberdeen Carbon Management Plan Higher Education Carbon Management Programme working with Page 1 The University of Aberdeen Carbon Management Programme Carbon Management Plan (CMP

Levi, Ran

370

Nanoporous carbons through direct carbonization of a zeolitic imidazolate framework for supercapacitor electrodes.  

PubMed

Nanoporous carbons with high surface area are achieved through direct carbonization of a commercially available zeolitic imidazolate framework (ZIF-8) without any additional carbon sources. The resultant nanoporous carbons exhibit high electrochemical capacitances in an acidic aqueous electrolyte. PMID:22710974

Chaikittisilp, Watcharop; Hu, Ming; Wang, Hongjing; Huang, Hou-Sheng; Fujita, Taketoshi; Wu, Kevin C-W; Chen, Lin-Chi; Yamauchi, Yusuke; Ariga, Katsuhiko

2012-07-25

371

Carbon14 labeling of phytoplankton carbon and chlorophyll a carbon: determination of specific growth rates  

Microsoft Academic Search

The pattern of photosynthetic ¹⁴C labeling over time is described for phytoplankton. The carbon-specific growth rate (d⁻¹) is defined explicitly by changes in the specific activity (dpm x ..mu..g⁻¹ C) of the algae. For Skeletonema costatum, growing in axenic batch culture, the specific activities of both total cellular carbon and chlorophyll carbon increase at equal rates and the change in

NICHOLAS A. WELSCHMEYER; CARL J. LORENZEN

1984-01-01

372

STUDY ON ELASTOPLASTIC BEHAVIOR OF DIFFERENT CARBON TYPES IN CARBON\\/CARBON COMPOSITES  

Microsoft Academic Search

Indentation tests combined with the knowledge of corresponding microstructure of carbonaceous materials offer valuable information that cannot be extracted from the conventional indentation tests alone. Since mechanical properties of carbon are sensitive to the crystal orientation, inelastic mechanisms can be detected by studying the stress-strain behavior of carbon\\/carbon composites. The aim of this paper is to investigate the elasto-plastic behavior

Soydan Ozcan; Jale Tezcan; Jane Y Howe; Peter Filip

2008-01-01

373

Compressed carbon nanotubes: A family of new multifunctional carbon allotropes  

PubMed Central

The exploration of novel functional carbon polymorphs is an enduring topic of scientific investigations. In this paper, we present simulations demonstrating metastable carbon phases as the result of pressure induced carbon nanotube polymerization. The configuration, bonding, electronic, and mechanical characteristics of carbon polymers strongly depend on the imposed hydrostatic/non-hydrostatic pressure, as well as on the geometry of the raw carbon nanotubes including diameter, chirality, stacking manner, and wall number. Especially, transition processes under hydrostatic/non-hydrostatic pressure are investigated, revealing unexpectedly low transition barriers and demonstrating sp2?sp3 bonding changes as well as peculiar oscillations of electronic property (e.g., semiconducting?metallic?semiconducting transitions). These polymerized nanotubes show versatile and superior physical properties, such as superhardness, high tensile strength and ductility, and tunable electronic properties (semiconducting or metallic). PMID:23435585

Hu, Meng; Zhao, Zhisheng; Tian, Fei; Oganov, Artem R.; Wang, Qianqian; Xiong, Mei; Fan, Changzeng; Wen, Bin; He, Julong; Yu, Dongli; Wang, Hui-Tian; Xu, Bo; Tian, Yongjun

2013-01-01

374

Compressed carbon nanotubes: a family of new multifunctional carbon allotropes.  

PubMed

The exploration of novel functional carbon polymorphs is an enduring topic of scientific investigations. In this paper, we present simulations demonstrating metastable carbon phases as the result of pressure induced carbon nanotube polymerization. The configuration, bonding, electronic, and mechanical characteristics of carbon polymers strongly depend on the imposed hydrostatic/non-hydrostatic pressure, as well as on the geometry of the raw carbon nanotubes including diameter, chirality, stacking manner, and wall number. Especially, transition processes under hydrostatic/non-hydrostatic pressure are investigated, revealing unexpectedly low transition barriers and demonstrating sp(2)?sp(3) bonding changes as well as peculiar oscillations of electronic property (e.g., semiconducting?metallic?semiconducting transitions). These polymerized nanotubes show versatile and superior physical properties, such as superhardness, high tensile strength and ductility, and tunable electronic properties (semiconducting or metallic). PMID:23435585

Hu, Meng; Zhao, Zhisheng; Tian, Fei; Oganov, Artem R; Wang, Qianqian; Xiong, Mei; Fan, Changzeng; Wen, Bin; He, Julong; Yu, Dongli; Wang, Hui-Tian; Xu, Bo; Tian, Yongjun

2013-01-01

375

Prospects for using carbon-carbon composites for EMI shielding  

NASA Technical Reports Server (NTRS)

Since pyrolyzed carbon has a higher electrical conductivity than most polymers, carbon-carbon composites would be expected to have higher electromagnetic interference (EMI) shielding ability than polymeric resin composites. A rule of mixtures model of composite conductivity was used to calculate the effect on EMI shielding of substituting a pyrolyzed carbon matrix for a polymeric matrix. It was found that the improvements were small, no more than about 2 percent for the lowest conductivity fibers (ex-rayon) and less than 0.2 percent for the highest conductivity fibers (vapor grown carbon fibers). The structure of the rule of mixtures is such that the matrix conductivity would only be important in those cases where it is much higher than the fiber conductivity, as in metal matrix composites.

Gaier, James R.

1990-01-01

376

Comparison of carbon onions and carbon blacks as conductive additives for carbon supercapacitors in organic electrolytes  

NASA Astrophysics Data System (ADS)

This study investigates carbon onions (?400 m2 g-1) as a conductive additive for supercapacitor electrodes of activated carbon and compares their performance with carbon black with high or low internal surface area. We provide a study of the electrical conductivity and electrochemical behavior between 2.5 and 20 mass% addition of each of these three additives to activated carbon. Structural characterization shows that the density of the resulting film electrodes depends on the degree of agglomeration and the amount of additive. Addition of low surface area carbon black (?80 m2 g-1) enhances the power handling of carbon electrodes but significantly lowers the specific capacitance even when adding small amounts of carbon black. A much lower decrease in specific capacitance is observed for carbon onions and the best values are seen for carbon black with a high surface area (?1390 m2 g-1). The overall performance benefits from the addition of any of the studied additives only at either high scan rates and/or electrolytes with high ion mobility. Normalization to the volume shows a severe decrease in volumetric capacitance and only at high current densities nearing 10 A g-1 we can see an improvement of the electrode capacitance.

Jäckel, N.; Weingarth, D.; Zeiger, M.; Aslan, M.; Grobelsek, I.; Presser, V.

2014-12-01

377

Carbon Footprint Exercise  

NSDL National Science Digital Library

Step 1. Students are asked to keep track of their energy use from a variety of sources (heating/cooling, electricity, transportation, secondary emissions, etc) during the 9 days of Thanksgiving break, when many of them are likely to travel. They use the total for the 9 days that they calculated using an online calculator to estimate their yearly footprint and compare it to US and world averages. For most of them, the amount of carbon emitted during those 9 days is quite large because of airplane travel or long-distance driving. However, using a week of break when many students will travel allows them to become aware of the significance of transportation in carbon emissions. We provided a table with electricity and heating/cooling bills for various residence halls for students who stay on campus during the break. Step 2. Students complete an online survey where they are asked to enter the values that they have obtained for the various components of the calculator, perform some simple calculations and compare their annual footprint to the U.S. average. We used SurveyGizmo for the survey because it allows to download the data in a spreadsheet format and has some limited plotting features. The free version allows a maximum of 250 submissions, the Basic version ($19 per month, can be canceled at any time) has unlimited submissions. Step 3. Students write an essay through BlackBoard/WebCT (Assignment). A few guiding questions are provided for this essay where students reflect on the results of their impact on the global carbon budget, what they found surprising, and if they plan to make any changes to their lifestyle to limit their impact. No length limit is set for the essay. The guidelines and components of this assignment are available on a wiki page. The three steps can be implemented in BlackBoard/WebCT as a Lesson Plan with links to the online calculator (step 1), to the survey (step 2), and to the Assignment/essay (step 3).

Cervato, Cinzia

378

Carbon Dioxide Capture and Disposal  

Microsoft Academic Search

Unless carbon dioxide from fossil fuel combustion is captured and disposed of safely and permanently, the concerns over climate change will eventually lead to the demise of fossil fuels. Because of their importance in today's energy market the phasing out of fossil fuels would likely precipitate a major energy crisis. Mineral sequestration and extraction of carbon dioxide from the air

K. S. Lackner

2002-01-01

379

Big Sky Carbon Sequestration Partnership  

Microsoft Academic Search

The Big Sky Carbon Sequestration Partnership, led by Montana State University, is comprised of research institutions, public entities and private sectors organizations, and the Confederated Salish and Kootenai Tribes and the Nez Perce Tribe. Efforts under this Partnership in Phase I fall into four areas: evaluation of sources and carbon sequestration sinks that will be used to determine the location

Susan M. Capalbo

2005-01-01

380

Acetic Acid Catalyzed Carbon Aerogels  

Microsoft Academic Search

We prepared carbon aerogels with a wide range of structural properties and densities using the weak acetic acid as a catalyst. Two series of acetic acid catalyzed carbon aerogels with different dilution of the catalyst and the monomers were investigated accurately. Structural investigation was performed via (U)SAXS, gas sorption and SEM. The pore and particle size can be tailored according

R. Brandt; R. Petricevic; H. Pröbstle; J. Fricke

2003-01-01

381

Bioenergy technologies for carbon abatement  

Microsoft Academic Search

In this paper, bioenergy technologies (BETs) are presented as potential carbon abatement opportunities substituting fossil fuel or traditional (less efficient) biomass energy systems. Cost of energy (produced or saved) of BETs is compared with fossil fuel and traditional biomass energy systems to estimate the incremental cost (IC). The IC of carbon abatement for each of the selected BETs (in $kWh?1

N. H. Ravindranath; P. Balachandra; S. Dasappa; K. Usha Rao

2006-01-01

382

Big Sky Carbon Sequestration Partnership  

Microsoft Academic Search

The Big Sky Carbon Sequestration Partnership, led by Montana State University, is comprised of research institutions, public entities and private sectors organizations, and the Confederated Salish and Kootenai Tribes and the Nez Perce Tribe. Efforts under this Partnership in Phase I are organized into four areas: (1) Evaluation of sources and carbon sequestration sinks that will be used to determine

Susan Capalbo

2005-01-01

383

Carbon Sequestration in Campus Trees  

NSDL National Science Digital Library

In this activity, students use a spreadsheet to calculate the net carbon sequestration in a set of trees; they will utilize an allometric approach based upon parameters measured on the individual trees. They determine the species of trees in the set, measure trunk diameter at a particular height, and use the spreadsheet to calculate carbon content of the tree using forestry research data.

Cole, Robert S.; Spreadsheets Across the Curruculum; Washington Center; Science Education Resource Center (SERC)

384

Atomic Structure of Carbon Nanomaterials  

E-print Network

#12;1.420 to 1.426 � 1.544 � 1.334 � Carbon Phase Diagram Heinmann R. B., Evsyukov S. E., and Koga, Y Diagram Heinmann R. B., Evsyukov S. E., and Koga, Y., Carbon 35 (1997), 1654�1658 #12;Pt/C Univ

Zuo, Jian-Min "Jim"

385

Minimizing activated carbons production cost  

Microsoft Academic Search

A detailed economic evaluation of activated carbons production process from various raw materials is undertaken using the conventional economic indices (ROI, POT, and NPV). The fundamental factors that affect production cost were taken into account. It is concluded that for an attractive investment in activated carbons production one should select the raw material with the highest product yield, adopt a

G. G. Stavropoulos; A. A. Zabaniotou

2009-01-01

386

SOURCE ASSESSMENT: CARBON BLACK MANUFACTURE  

EPA Science Inventory

The report summarizes the assessment of air emissions from the manufacture of carbon black, currently manufactured in the U.S. by two major processes: thermal and oil furnace. Sources of atmospheric emissions within oil furnace plants (about 90% of the 30 U.S. carbon black plants...

387

Method for producing carbon black  

SciTech Connect

A method is described for producing a relatively coarse, highly structured carbon black having a large surface area which comprises the steps of: (a) mixing a hydrocarbon feedstock with hot combustion gases at a high temperature in a reaction chamber wherein turbulence and stream velocity are relatively low in order to produce a preliminary coarse carbon black and effluent gases; (b) separating the produced preliminary coarse carbon black of step (a) from the effluent gases; (c) feeding the preliminary carbon black of step (a) into a reaction chamber wherein the preliminary carbon black is oxidized by hot combustion gases under controlled conditions of about 100 to 150 MCFH of air, about 0 to 4 MCFH of oxygen, about 6 to 14 MCFH of process gas, about 500 to 800 Lbs/hr of preliminary carbon black feedstock, at a blast ratio of about 7.1 to 25.1 and a total ratio of about 8.1 to 26.7, and wherein the residence time is between 1.5 and 4.5 seconds, to produce final large surface area, course, highly structured carbon black product and effluent gases; and (d) separating the final highly structured carbon black product of step (c) from the effluent gases.

Dickerson, T.

1988-07-05

388

Soil carbon: Resisting climate change  

NASA Astrophysics Data System (ADS)

Increasing temperatures are expected to increase decomposition rates in soils, potentially reducing ecosystem carbon storage. Research now indicates that -- in a tropical montane forest -- soil carbon stocks are unaffected by higher temperatures despite substantially increased rates of CO2 release from the soil.

Hartley, Iain P.

2014-09-01

389

Global distribution of carbon monoxide  

Microsoft Academic Search

This study explores the evolution and distribution of carbon monoxide (CO) using the National Oceanic and Atmospheric Administration (NOAA) Geophysical Fluid Dynamics Laboratory three-dimensional global chemical transport model (GFDL GCTM). The work aims to gain an improved understanding of the global carbon monoxide budget, specifically focusing on the contribution of each of the four source terms to the seasonal variability

Tracey Holloway; Hiram Levy; Prasad Kasibhatla

2000-01-01

390

Coral reefs and carbon dioxide  

SciTech Connect

This commentary argues the conclusion from a previous article, which investigates diurnal changes in carbon dioxide partial pressure and community metabolism on coral reefs, that coral `reefs might serve as a sink, not a source, for atmospheric carbon dioxide.` Commentaries from two groups are given along with the response by the original authors, Kayanne et al. 27 refs.

Buddemeier, R.W. [Kansas Geological Survey, Lawrence, KS (United States)

1996-03-01

391

Forest soils and carbon sequestration  

Microsoft Academic Search

Soils in equilibrium with a natural forest ecosystem have high carbon (C) density. The ratio of soil:vegetation C density increases with latitude. Land use change, particularly conversion to agricultural ecosystems, depletes the soil C stock. Thus, degraded agricultural soils have lower soil organic carbon (SOC) stock than their potential capacity. Consequently, afforestation of agricultural soils and management of forest plantations

R. Lal

2005-01-01

392

Carbon Nanotube Reinforced Polymer Nanocomposites  

E-print Network

Carbon Nanotube Reinforced Polymer Nanocomposites: Engineering the Interface at the Nano-Domain Wei of Art The Northrop Grumman Global Hawk is an unmanned aerial vehicle (UAV) Nano - Composites Polymer Nanocomposites The Ideal "Straws" ­ Carbon Nanotubes 7.80.4208Steel 2.61501200MWCNT 1.341501054SWCNT Density (g

Southern California, University of

393

Partial replacement of carbon fiber by carbon black in multifunctional cementmatrix composites  

E-print Network

Partial replacement of carbon fiber by carbon black in multifunctional cement­matrix composites and the EMI shielding effectiveness of cement, but carbon fiber is more effective than carbon black. Partial (50%) replacement of carbon fiber by carbon black lowers the cost, in addition to increasing

Chung, Deborah D.L.

394

Carbon Cycle Discussion After the warm-up quiz, discuss the carbon cycle.  

E-print Network

Carbon Cycle Discussion After the warm-up quiz, discuss the carbon cycle. Carbon is one: a reservoir where the stuff goes; carbon sink: ocean, landfills, trees Carbon cycling is a type the youtube video linked from the powerpoint on carbon cycling if there is extra time. #12;

Carrington, Emily

395

Production of precipitated calcium carbonate from calcium silicates and carbon dioxide  

Microsoft Academic Search

The possibilities for reducing carbon dioxide emissions from the pulp and paper industry by calcium carbonation are presented. The current precipitated calcium carbonate (PCC) production uses mined, crushed calcium carbonate as raw materials. If calcium silicates were used instead, carbon dioxide emissions from the calcination of carbonates would be eliminated. In Finland, there could, thus, be a potential for eliminating

Sebastian Teir; Sanni Eloneva; Ron Zevenhoven

2005-01-01

396

Royal College of Art Carbon Management Programme Carbon Management Plan working with  

E-print Network

Royal College of Art Carbon Management Programme Carbon Management Plan working with Page 1 Royal College of Art Carbon Management Programme Carbon Management Plan (CMP) Date: 25 February 2011 Final Board Approval status: Draft #12;Royal College of Art Carbon Management Programme Carbon Management Plan

Subramanian, Sriram

397

Carbon Dioxide Sequestration in Concrete Using Vacuum-Carbonation Alain Azar, Prof. Yixin Shao  

E-print Network

Carbon Dioxide Sequestration in Concrete Using Vacuum-Carbonation Alain Azar, Prof. Yixin Shao promising carbon uptake results and is a viable option for carbonation curing. Carbon sequestration increase in Carbon dioxide (CO2) emissions over the past five decades, specific ways to reduce

Barthelat, Francois

398

Electromagnetic interference shielding using continuous carbon-fiber carbon-matrix and polymer-matrix composites  

E-print Network

. Carbon-fiber; A. Carbon-carbon composites (CCCs); A. Polymer-matrix composites (PMCs); Electromagnetic, dense and abundant. Composites with discontinuous conducting fillers, such as metal particles, metal with continuous carbon-fibers (called carbon­carbon composites) are used for aerospace structures that require

Chung, Deborah D.L.

399

Carbon nanotube terahertz detector.  

PubMed

Terahertz (THz) technologies are promising for diverse areas such as medicine, bioengineering, astronomy, environmental monitoring, and communications. However, despite decades of worldwide efforts, the THz region of the electromagnetic spectrum still continues to be elusive for solid state technology. Here, we report on the development of a powerless, compact, broadband, flexible, large-area, and polarization-sensitive carbon nanotube THz detector that works at room temperature. The detector is sensitive throughout the entire range of the THz technology gap, with responsivities as high as ?2.5 V/W and polarization ratios as high as ?5:1. Complete thermoelectric and opto-thermal characterization together unambiguously reveal the photothermoelectric origin of the THz photosignal, triggered by plasmonic absorption and collective antenna effects, and suggest that judicious design of thermal management and quantum engineering of Seebeck coefficients will lead to further enhancement of device performance. PMID:24875576

He, Xiaowei; Fujimura, Naoki; Lloyd, J Meagan; Erickson, Kristopher J; Talin, A Alec; Zhang, Qi; Gao, Weilu; Jiang, Qijia; Kawano, Yukio; Hauge, Robert H; Léonard, François; Kono, Junichiro

2014-07-01

400

Carbon nanotube quantum resistors  

PubMed

The conductance of multiwalled carbon nanotubes (MWNTs) was found to be quantized. The experimental method involved measuring the conductance of nanotubes by replacing the tip of a scanning probe microscope with a nanotube fiber, which could be lowered into a liquid metal to establish a gentle electrical contact with a nanotube at the tip of the fiber. The conductance of arc-produced MWNTs is one unit of the conductance quantum G0 = 2e2/h = (12.9 kilohms)-1. The nanotubes conduct current ballistically and do not dissipate heat. The nanotubes, which are typically 15 nanometers wide and 4 micrometers long, are several orders of magnitude greater in size and stability than other typical room-temperature quantum conductors. Extremely high stable current densities, J > 10(7) amperes per square centimeter, have been attained. PMID:9624050

Frank; Poncharal; Wang; Heer

1998-06-12

401

Forests as carbon sinks  

SciTech Connect

When the nations of the world signed and later ratified the United Nations Framework Convention on Climate Change (FCCC), they accepted the difficult challenge of stabilizing the composition of the atmosphere with respect to the greenhouse gases (GHGs). Success will require a reduction in both use of fossil fuels and rates of deforestation. Forests have a large enough influence on the atmosphere that one of the options for stabilizing the concentrations of GHGs in the atmosphere includes the use of forests as a carbon sink through reforestation of large areas. We identify in this paper the potential and the limitations of such projects. We discuss the implications of four approaches in management of forests globally: (i) continued deforestation, (ii) halting deforestation, (iii) net reforestation including agroforestry, and (iv) substituting the use of wood fuels for fossil fuels.

Houghton, R.A.; Woodwell, R.M. [Woods Hole Research Center, Woods Hole, MA (United States)

1995-11-01

402

Helium diffusion in carbonates  

NASA Astrophysics Data System (ADS)

The abundance and large grain size of carbonate minerals make them a potentially attractive target for 4He thermochronology and 3He cosmogenic dating, although the diffusive properties of helium in carbonates remain poorly understood. This work characterizes helium diffusion in calcite and dolomite to better understand the crystal-chemical factors controlling He transport and retentivity. Slabs of cleaved natural calcite and dolomite, and polished sections of calcite cut parallel or normal to c, were implanted with 3He at 3 MeV with a dose of 5x1015/cm2. Implanted carbonates were heated in 1-atm furnaces, and 3He distributions following diffusion anneals were profiled with Nuclear Reaction Analysis using the reaction 3He(d,p)4He. For 3He transport normal to cleavage surfaces in calcite, we obtain the following Arrhenius relation over the temperature range 78-300°C: Dcalcite = 9.0x10-9exp(-55 × 6 kJ mol-1/RT) m2sec-1. Diffusion in calcite exhibits marked anisotropy, with diffusion parallel to c about two orders of magnitude slower than diffusion normal to cleavage faces. He diffusivities for transport normal to the c-axis are similar in value to those normal to cleavage surfaces. Our findings are broadly consistent with helium diffusivities from step-heating measurements of calcite by Copeland et al. (2007); these bulk degassing data may reflect varying effects of diffusional anisotropy. Helium diffusion normal to cleavage surfaces in dolomite is significantly slower than diffusion in calcite, and has a much higher activation energy for diffusion. For dolomite, we obtain the following Arrhenius relation for He diffusion over the temperature range 150-400°C: Ddolomite = 9.0x10-8exp(-92 × 9 kJ mol-1/RT) m2sec-1. The role of crystallographic structure in influencing these differences among diffusivities was evaluated using the maximum aperture approach of Cherniak and Watson (2011), in which crystallographic structures are sectioned along possible diffusion directions and the maximum interstitial apertures in each 'slice' in the structure are identified. Preliminary results show that observed differences in diffusivities are consistent with the size of the smallest maximum aperture along each diffusion direction. In calcite, the smallest maximum apertures are ~0.92 and ~0.66 angstroms for cleavage-normal and c-axis parallel directions respectively. In dolomite, the smallest maximum aperture is ~0.78 angstroms for the cleavage normal direction. Work is in progress on characterizing helium diffusion for other orientations in dolomite, and in other carbonates, including aragonite and magnesite, and in implementing these diffusion findings in the interpretation and modeling of bulk volume diffusion in heterogeneous calcite crystals common in many geologic applications. Copeland et al. (2007) GCA 71, 4488-4511 Cherniak and Watson, (2011) Chem. Geo. 288, 149-161

Amidon, W. H.; Cherniak, D. J.; Watson, E. B.; Hobbs, D.

2013-12-01

403

Functionalization of Carbon Nanotubes  

NASA Technical Reports Server (NTRS)

Method and system for functionalizing a collection of carbon nanotubes (CNTs). A selected precursor gas (e.g., H2 or F2 or CnHm) is irradiated to provide a cold plasma of selected target species particles, such as atomic H or F, in a first chamber. The target species particles are d irected toward an array of CNTs located in a second chamber while suppressing transport of ultraviolet radiation to the second chamber. A CNT array is functionalized with the target species particles, at or below room temperature, to a point of saturation, in an exposure time interval no longer than about 30 sec. *Discrimination against non-target species is provided by (i) use of a target species having a lifetime that is much greater than a lifetime of a non-target species and/or (2) use of an applied magnetic field to discriminate between charged particle trajectories for target species and for non-target species.

Khare, Bishun N. (Inventor); Meyyappan, Meyya (Inventor)

2009-01-01

404

Nanoindentation of carbon materials  

NASA Astrophysics Data System (ADS)

The compressive behaviour of carbon materials has been investigated by modelling the recently developed method of nanoindentation. Molecular dynamics simulations are employed to investigate the indentation of a diamond cube-corner apex into graphite {0 0 0 1}, diamond {0 0 1} and a C 60 substrate. Simulations performed on graphite show that the crystal undergoes an elastic deformation. Indentation of diamond shows some elastic behaviour but also tip damage. Indentation on a C 60 film reflects a weakly bonded material with the emission of surface C 60 molecules and a plastic deformation of the material. Penetration of the substrate surfaces shows compression of the tip apex and in the case of the diamond substrate, extraction causes blunting by the transfer of atoms from the tip to the substrate. Some qualitative comparisons are made to experiment but available computer power constrains feasible indentation depths to an order of magnitude smaller than experiment and over indentation times several orders of magnitude smaller.

Christopher, David; Smith, Roger; Richter, Asta

2001-06-01

405

Total organic carbon analyzer  

NASA Technical Reports Server (NTRS)

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

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

1991-01-01

406

Carbon nanotube Archimedes screws.  

PubMed

Recently, nanomechanical devices composed of a long stationary inner carbon nanotube and a shorter, slowly rotating outer tube have been fabricated. In this paper, we study the possibility of using such devices as nanoscale transducers of motion into electricity. When the outer tube is chiral, we show that such devices act like quantum Archimedes screws, which utilize mechanical energy to pump electrons between reservoirs. We calculate the pumped charge from one end of the inner tube to the other, driven by the rotation of a chiral outer nanotube. We show that the pumped charge can be greater than one electron per 360° rotation, and consequently, such a device operating with a rotational frequency of 10 MHz, for example, would deliver a current of ?1 pAmp. PMID:21126086

Oroszlány, László; Zólyomi, Viktor; Lambert, Colin J

2010-12-28

407

Carbon nanotube electron gun  

NASA Technical Reports Server (NTRS)

An electron gun, an electron source for an electron gun, an extractor for an electron gun, and a respective method for producing the electron gun, the electron source and the extractor are disclosed. Embodiments provide an electron source utilizing a carbon nanotube (CNT) bonded to a substrate for increased stability, reliability, and durability. An extractor with an aperture in a conductive material is used to extract electrons from the electron source, where the aperture may substantially align with the CNT of the electron source when the extractor and electron source are mated to form the electron gun. The electron source and extractor may have alignment features for aligning the electron source and the extractor, thereby bringing the aperture and CNT into substantial alignment when assembled. The alignment features may provide and maintain this alignment during operation to improve the field emission characteristics and overall system stability of the electron gun.

Nguyen, Cattien V. (Inventor); Ribaya, Bryan P. (Inventor)

2010-01-01

408

Carbon Dioxide Landscape  

NASA Technical Reports Server (NTRS)

7 July 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a mid-summer view of the south polar residual cap at full MOC resolution, 1.5 m (5 ft) per pixel. During each of the three summers since the start of the MGS mapping mission in March 1999, the scarps that form mesas and pits in the 'Swiss cheese'-like south polar terrain have retreated an average of about 3 meters (1 yard). The material is frozen carbon dioxide; another 3 meters or so of each scarp is expected to be removed during the next summer, in late 2005. This image is located near 86.0oS, 350.8oW, and covers an area about 1.5 km (0.9 mi) wide. Sunlight illuminates the scene from the top/upper left.

2004-01-01

409

mineral sequestration by wollastonite carbonation  

NASA Astrophysics Data System (ADS)

In this paper, we demonstrated a new approach to CO2 mineral sequestration using wollastonite carbonation assisted by sulfuric acid and ammonia. Samples were characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and 29Si nuclear magnetic resonance. The change in Gibbs free energy from -223 kJ/mol for the leaching reaction of wollastonite to -101 kJ/mol for the carbonation reaction indicated that these two reactions can proceed spontaneously. The leached and carbonated wollastonite showed fibrous bassanite and granular calcium carbonate, respectively, while the crystal structure of pristine wollastonite was destroyed and the majority of the Ca2+ in pristine wollastonite leached. The chemical changes in the phases were monitored during the whole process. A high carbonation rate of 91.1 % could be obtained under the action of sulfuric acid and ammonia at 30 °C at normal atmospheric pressure, indicating its potential use for CO2 sequestration.

Ding, Wenjin; Fu, Liangjie; Ouyang, Jing; Yang, Huaming

2014-07-01

410

Molecular Structure of Carbon Dioxide  

NSDL National Science Digital Library

Carbon dioxide was first described in the 17th century by Jan Baptist van Helmont, a Belgium chemist. The chemical CO2 is released into the atmosphere when carbon-containing fossil fuels like oil, natural gas, and coal are burned in air. It is also produced by various microorganisms in fermentation and is breathed out by animals. Plants absorb carbon dioxide during photosynthesis, using both the carbon and the oxygen to construct carbohydrates. Every year the amount of CO2 in the atmosphere is increasing. CO2 build-up in the atmosphere is caused by deforestation, therefore reducing the number of trees available to absorb CO2. Excess CO2 in the environment causes Global Warming and the Greenhouse Effect. It is also toxic to humans since inhalation of large amounts of CO2 can cause suffocation. Some beverages, such as beer and sparkling wine contain carbon dioxide as a result of fermentation.

2002-08-15

411

Method for producing carbon nanotubes  

DOEpatents

Method for producing carbon nanotubes. Carbon nanotubes were prepared using a low power, atmospheric pressure, microwave-generated plasma torch system. After generating carbon monoxide microwave plasma, a flow of carbon monoxide was directed first through a bed of metal particles/glass beads and then along the outer surface of a ceramic tube located in the plasma. As a flow of argon was introduced into the plasma through the ceramic tube, ropes of entangled carbon nanotubes, attached to the surface of the tube, were produced. Of these, longer ropes formed on the surface portion of the tube located in the center of the plasma. Transmission electron micrographs of individual nanotubes revealed that many were single-walled.

Phillips, Jonathan (Santa Fe, NM); Perry, William L. (Jemez Springs, NM); Chen, Chun-Ku (Albuquerque, NM)

2006-02-14

412

CALCIUM CARBONATE DEPOSITION IN GEOTHERMAL WELLBORES  

E-print Network

CALCIUM CARBONATE DEPOSITION IN GEOTHERMAL WELLBORES MIRAVALLES GEOTHERMAL FIELD COSTA RICA CALCIUM CARBONATE DEPOSITION IN GEOTHERMAL WELLBORES MIRAVALLES GEOTHERMAL FIELD COSTA RICA BY Eduardo University. #12;ABSTRACT Calcium carbonate deposition takes place in the wells of the Miravalles geothermal

Stanford University

413

21 CFR 184.1191 - Calcium carbonate.  

...1) As a byproduct in the “Lime soda process”; (2) By precipitation of calcium carbonate from calcium hydroxide in the “Carbonation process”; or (3) By precipitation of calcium carbonate from calcium...

2014-04-01

414

21 CFR 582.1425 - Magnesium carbonate.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 2013-04-01 false Magnesium carbonate. 582.1425 Section 582.1425...General Purpose Food Additives § 582.1425 Magnesium carbonate. (a) Product. Magnesium carbonate. (b) Conditions of use....

2013-04-01

415

21 CFR 582.1425 - Magnesium carbonate.  

Code of Federal Regulations, 2011 CFR

... 2011-04-01 2011-04-01 false Magnesium carbonate. 582.1425 Section 582.1425...General Purpose Food Additives § 582.1425 Magnesium carbonate. (a) Product. Magnesium carbonate. (b) Conditions of use....

2011-04-01

416

21 CFR 582.1425 - Magnesium carbonate.  

... 2014-04-01 2014-04-01 false Magnesium carbonate. 582.1425 Section 582.1425...General Purpose Food Additives § 582.1425 Magnesium carbonate. (a) Product. Magnesium carbonate. (b) Conditions of use....

2014-04-01

417

21 CFR 582.1425 - Magnesium carbonate.  

Code of Federal Regulations, 2012 CFR

... 2012-04-01 2012-04-01 false Magnesium carbonate. 582.1425 Section 582.1425...General Purpose Food Additives § 582.1425 Magnesium carbonate. (a) Product. Magnesium carbonate. (b) Conditions of use....

2012-04-01

418

21 CFR 582.1425 - Magnesium carbonate.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 2010-04-01 false Magnesium carbonate. 582.1425 Section 582.1425...General Purpose Food Additives § 582.1425 Magnesium carbonate. (a) Product. Magnesium carbonate. (b) Conditions of use....

2010-04-01

419

DENSITY OF STATES CALCULATIONS FOR CARBON  

E-print Network

DENSITY OF STATES CALCULATIONS FOR CARBON ALLOTROPES AND MIXTURES EDUARDO WARSZAWSKI #12;#12;DENSITY OF STATES CALCULATIONS FOR CARBON ALLOTROPES AND MIXTURES Research Thesis Submitted in Partial;#12;Contents Abstract xiii 1 Introduction 1 1.1 Carbon allotropes

Adler, Joan

420

Mesophase Behavior in Carbon Fiber Bundles.  

National Technical Information Service (NTIS)

Some experimental procedures required to observe the development of mesophase morphologies in three-dimensional carbon-carbon composites during pyrolysis at high pressures have been tested in preliminary room-pressure trials. Bundles of mesophase carbon f...

C. B. Ng J. L. White, M. Buechler, P. M. Sheaffer

1982-01-01

421

The Carbon Crisis in 90 Seconds  

NSDL National Science Digital Library

This video features a short animated sequence that illustrates the difference between young and old carbon released into the atmosphere from the consumption of food (young carbon) and the burning of fossil fuels (old carbon).

Nasa

422

Carbon Dioxide Reduction Through Urban Forestry  

E-print Network

Carbon Dioxide Reduction Through Urban Forestry: Guidelines for Professional and Volunteer Tree; Simpson, James R. 1999. Carbon dioxide reduction through urban forestry of Agriculture; 237 p. Carbon dioxide reduction through urban forestry--Guidelines for professional and volunteer

Standiford, Richard B.

423

Carbon Anode Materials  

NASA Astrophysics Data System (ADS)

Accompanying the impressive progress of human society, energy storage technologies become evermore urgent. Among the broad categories of energy sources, batteries or cells are the devices that successfully convert chemical energy into electrical energy. Lithium-based batteries stand out in the big family of batteries mainly because of their high-energy density, which comes from the fact that lithium is the most electropositive as well as the lightest metal. However, lithium dendrite growth after repeated charge-discharge cycles easily will lead to short-circuit of the cells and an explosion hazard. Substituting lithium metal for alloys with aluminum, silicon, zinc, and so forth could solve the dendrite growth problem.1 Nevertheless, the lithium storage capacity of alloys drops down quickly after merely several charge-discharge cycles because the big volume change causes great stress in alloy crystal lattice, and thus gives rise to cracking and crumbling of the alloy particles. Alternatively, Sony Corporation succeeded in discovering the highly reversible, low-voltage anode, carbonaceous material and commercialized the C/LiCoO2 rocking chair cells in the early 1990s.2 Figure 3.1 schematically shows the charge-discharge process for reversible lithium storage in carbon. By the application of a lithiated carbon in place of a lithium metal electrode, any lithium metal plating process and the conditions for the growth of irregular dendritic lithium could be considerably eliminated, which shows promise for reducing the chances of shorting and overheating of the batteries. This kind of lithium-ion battery, which possessed a working voltage as high as 3.6 V and gravimetric energy densities between 120 and 150 Wh/kg, rapidly found applications in high-performance portable electronic devices. Thus the research on reversible lithium storage in carbonaceous materials became very popular in the battery community worldwide.

Ogumi, Zempachi; Wang, Hongyu

424

Catalytic Growth of Macroscopic Carbon Nanofibers Bodies with Activated Carbon  

NASA Astrophysics Data System (ADS)

Carbon-carbon composite of activated carbon and carbon nanofibers have been synthesized by growing Carbon nanofiber (CNF) on Palm shell-based Activated carbon (AC) with Ni catalyst. The composites are in an agglomerated shape due to the entanglement of the defective CNF between the AC particles forming a macroscopic body. The macroscopic size will allow the composite to be used as a stabile catalyst support and liquid adsorbent. The preparation of CNT/AC nanocarbon was initiated by pre-treating the activated carbon with nitric acid, followed by impregnation of 1 wt% loading of nickel (II) nitrate solutions in acetone. The catalyst precursor was calcined and reduced at 300° C for an hour in each step. The catalytic growth of nanocarbon in C2H4/H2 was carried out at temperature of 550° C for 2 hrs with different rotating angle in the fluidization system. SEM and N2 isotherms show the level of agglomeration which is a function of growth density and fluidization of the system. The effect of fluidization by rotating the reactor during growth with different speed give a significant impact on the agglomeration of the final CNF/AC composite and thus the amount of CNFs produced. The macrostructure body produced in this work of CNF/AC composite will have advantages in the adsorbent and catalyst support application, due to the mechanical and chemical properties of the material.

Abdullah, N.; Rinaldi, A.; Muhammad, I. S.; Hamid, S. B. Abd.; Su, D. S.; Schlogl, R.

2009-06-01

425

Process for making hollow carbon spheres  

DOEpatents

A hollow carbon sphere having a carbon shell and an inner core is disclosed. The hollow carbon sphere has a total volume that is equal to a volume of the carbon shell plus an inner free volume within the carbon shell. The inner free volume is at least 25% of the total volume. In some instances, a nominal diameter of the hollow carbon sphere is between 10 and 180 nanometers.

Luhrs, Claudia C.; Phillips, Jonathan; Richard, Monique N.; Knapp, Angela Michelle

2013-04-16

426

Ureilite Carbon and mg Number  

NASA Astrophysics Data System (ADS)

Ureilites are carbon-bearing ultramafic achondrites composed primarily of olivine and pyroxene with intergranular fine-grained metal, sulfides, and silicates. Carbon (up to 6.5 wt%) is either amorphous or present as graphite, lonsdaleite, and/or diamond. It has been shown that carbon-silicate redox (i.e. "smelting") reactions are responsible for the positive correlation between modal percent pigeonite and mg# and for the negative FeO-MnO trend seen in the mineral and bulk compositions of ureilites. Carbon redox reactions are strongly exothermic and pressure dependent; so ureilites with the largest mg# are the most reduced, experienced the highest temperatures, and formed at the lowest pressures, i.e. near the surface of the ureilite parent body. Ureilites with the largest mg# have the smallest ? 18O and the largest ? 17O. To further investigate possible relationships, we performed carbon isotope and electron probe measurements on a suite of 27 ureilites in order to see the type of correlation that exists between mg# and carbon. Mg#s of olivine cores, carbon contents, and ? 13C data were taken from this study and the literature, and averaged. Polymict ureilites were not considered. A well-defined negative correlation is observed between the mg# of olivine cores and ? 17O. A less well-defined negative correlation may exist between mg# of olivine cores and ? 13C, but there is substantial scatter in the data. However, a well-defined negative correlation exists between mg# of olivine rims and ? 13C. At first glance, this trend is unexpected: if ureilites with the largest mg# experienced the greatest amount of reduction, they should have the largest ? 13C and the correlation between mg# and ? 13C should be positive. A plot of carbon content versus ? 13C seems to show a general trend: the smaller the carbon content, the heavier is the carbon. This general trend is exactly what one would expect if smelting has affected the ureilite parent body: the more C is consumed during smelting, the heavier the residue become. However, mg#s do not support this interpretation: ureilites with the largest mg# have the smallest carbon content and the smallest ? 13C, while ureilites with the largest mg# have the opposite. To explain this apparent contradiction, one needs to consider that ureilites have experienced two reducing events. The first one is recorded in the cores of the olivine crystals while the second is seen in the strongly reduced rims. During the heating of the ureilite parent body, the olivine cores first equilibrated with the carbon and their mg# were fixed according to their depth: the deepest olivine experienced little reduction, had low mg#, relatively light carbon (? 13C < -10 ‰ ) and high carbon content (about 7-8 wt%); the shallowest olivines experienced the greatest reduction, resulting in high mg#, relatively light carbon (? 13C < -8 to -10‰ ) and low carbon content (about 4 wt%). The second reducing event was marked by a sudden drop in pressure (possibly due to an impact that disrupted the parent body). During this event, olivines that formed at depth were now strongly reduced along their rims (the cores preserved their initial mg#), their carbon became heavier (? 13C > -8‰ ) and their carbon content decreased (below about 4 wt%). On the other hand, olivines that formed initially near the surface of the parent body did not experience much change in terms of mg#, ? 13C, and carbon content.

Hudon, P.; Romanek, C.; Paddock, L.; Mittlefehldt, D. W.

2004-05-01

427

Carbon sequestration in European croplands.  

PubMed

The Marrakech Accords allow biospheric carbon sinks and sources to be included in attempts to meet emission reduction targets for the first commitment period of the Kyoto Protocol. Forest management, cropland management, grazing land management, and re-vegetation are allowable activities under Article 3.4 of the Kyoto Protocol. Soil carbon sinks (and sources) can, therefore, be included under these activities. Croplands are estimated to be the largest biospheric source of carbon lost to the atmosphere in Europe each year, but the cropland estimate is the most uncertain among all land-use types. It is estimated that European croplands (for Europe as far east as the Urals) lose 300 Tg (C) per year, with the mean figure for the European Union estimated to be 78 Tg (C) per year (with one SD=37). National estimates for EU countries are of a similar order of magnitude on a per-area basis. There is significant potential within Europe to decrease the flux of carbon to the atmosphere from cropland, and for cropland management to sequester soil carbon, relative to the amount of carbon stored in cropland soils at present. The biological potential for carbon storage in European (EU 15) cropland is of the order of 90-120 Tg (C) per year, with a range of options available that include reduced and zero tillage, set-aside, perennial crops, deep rooting crops, more efficient use of organic amendments (animal manure, sewage sludge, cereal straw, compost), improved rotations, irrigation, bioenergy crops, extensification, organic farming, and conversion of arable land to grassland or woodland. The sequestration potential, considering only constraints on land use, amounts of raw materials and available land, is up to 45 Tg (C) per year. The realistic potential and the conservative achievable potentials may be considerably lower than the biological potential because of socioeconomic and other constraints, with a realistically achievable potential estimated to be about 20% of the biological potential. As with other carbon sequestration options, potential impacts of non-CO, trace gases also need to be factored in. If carbon sequestration in croplands is to be used in helping to meet emission reduction targets for the first commitment period of the Kyoto Protocol, the changes in soil carbon must be measurable and verifiable. Changes in soil carbon can be difficult to measure over a 5-year commitment period, and this has implications for Kyoto accounting and verification. Currently, most countries can hope to achieve only a low level of verifiability during the first commitment period, whereas those with the best-developed national carbon accounting systems will be able to deliver an intermediate level of verifiability. Very stringent definitions of verifiability would require verification that would be prohibitively expensive for any country. There is considerable potential in European croplands to reduce carbon fluxes to the atmosphere and to sequester carbon iri the soil, but carbon sequestration in soil has a finite potential and is non-permanent. Given that carbon sequestration may also be difficult to measure and verify, soil carbon sequestration is a riskier long-term strategy for climate mitigation than direct reduction of carbon emissions. However, improved agricultural management often has a range of other environmental and economic benefits in addition to climate mitigation potential, and this may make attempts to improve soil carbon storage attractive as part of integrated sustainability policies. PMID:17633030

Smith, Pete; Falloon, Pete

2005-01-01

428

Carbon scaffolding: building acetylenic all-carbon and carbon-rich compounds  

Microsoft Academic Search

The preparation of acetylenic molecular and polymeric carbon allotropes and carbon-rich nanometre-sized structures opens new avenues of fundamental and technological research at the interface between chemistry and materials science. Unusual structures, high stability and useful electrical and nonlinear optical properties are some of the desirable characteristics of these materials.

François Diederich

1994-01-01

429

A 400 million year carbon isotope record of pedogenic carbonate: Implications for paleoatmospheric carbon dioxide  

Microsoft Academic Search

A 400 record of atmospheric carbon dioxide levels has been estimated by applying a COâ paleobarometer to a database of 758 analyses of paleosol (fossil soil) carbonates. This database is a compilation of new data and previously published values from the literature. Many new analyses of Mesozoic paleosols are reported, an era poorly represented in the literature. Results indicate that

D. D. Ekart; T. E. Cerling; I. P. Montanez; N. J. Tabor

1999-01-01

430

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

SciTech Connect

Temperature-programmed reaction was used with labeled isotopes (/sup 13/C and /sup 18/O) to study interactions between carbon black and potassium carbonate in pure He and 10% CO/sub 2//90% He atmospheres. Catalytic gasification precursor complexes were observed. Carbon and oxygen-bearing carbon surface groups interacted with the carbonate above 500 K to form surface complexes. Between 500 and 950 K, and in the presence of gaseous CO/sub 2/, the complexes participated in C and O exchange with the gas phase while oxygen atoms within the complexes also exchanged with those on the carbon surface. As the temperature rose, the complexes decomposed, with CO/sub 2/ the initial product. Decomposition started around 500 K in pure He, and around 950 K in CO/sub 2//He. Catalytic gasification began only after decomposition of significant portions of the complexes. Elemental potassium formed, and the active catalyst appears to alternate between being potassium metal and a potassium-oxygen-carbon complex. Potassium carbonate is not part of the catalytic cycle. 20 references, 10 figures.

Saber, J.M.; Falconer, J.L.; Brown, L.F.

1984-11-01

431

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

Microsoft Academic Search

Preforms containing 0, 5, 10, 15 and 20wt.% carbon nanofibers (CNFs) were fabricated by spreading layers of carbon cloth, and infiltrated using the electrified preform heating chemical vapor infiltration method (ECVI) under atmospheric pressure. Initial thermal gradients were determined. Resistivity and density evolutions with infiltration time have been recorded. Scanning electron microscopy, polarized light micrograph and X-ray diffraction technique were

Jinsong Li; Ruiying Luo; Ying Yan

2011-01-01

432

Spectral evidence for carbonates on Mars: Hydrous carbonates  

NASA Technical Reports Server (NTRS)

Although many of the spectral features of the Martian samples studied are not unique mineralogical indicators, much of the current spectral data is consistent with (possibly abundant) hydrous carbonates on the surface of Mars. The absorption features in the measured samples were quite weak compared with those of anhydrous carbonates. The weak features imply that significantly more hydrous carbonates can be incorporated onto the surface before becoming spectrally evident; however, exact limits have yet to be determined. The stability of these materials in the Martian environment is not known, but their formation and occurrence in low temperature terrestrial environments makes them appealing candidates for weathering products on Mars.

Calvin, W. M.; King, T. V. V.

1991-01-01

433

UCSF Sustainability Baseline Assessment: Carbon Footprint Analysis  

E-print Network

UCSF Sustainability Baseline Assessment: Carbon Footprint Analysis Final Issue Date: March 21, 2010 #12;Carbon Footprint Analysis Background This chapter of the Sustainability Assessment focuses on UCSF

Yamamoto, Keith

434

[Progress of researches on carbon/carbon composites used in human loaded bones].  

PubMed

Carbon/carbon composites have excellent biocompatibility with human hard tissue and elasticity modulus similar with that of human bones, which endow them great potential applications in substitution for human loaded bones. The current research situations and applications of carbon/carbon composites in human loaded bones are reviewed. The coating technologies of bioactive layers on carbon/carbon composites are discussed. The problems to be solved and the prospects of carbon/carbon composites in human loaded bones are analyzed and predicted. It is believed that bioactive layers coating on carbon/carbon composites should play an important role in human loaded bones. PMID:15357462

Sui, Jinling; Li, Musen; Lü, Yupeng

2004-08-01

435

Gas permeability of carbon aerogels  

SciTech Connect

Carbon aerogels are synthesized via the aqueous polycondensation of resorcinol with formaldehyde, followed by supercritical drying and subsequent pyrolysis at 1050 [degree]C. As a result of their interconnected porosity, ultrafine cell/pore size, and high surface area, carbon aerogels have many potential applications such as supercapacitors, battery electrodes, catalyst supports, and gas filters. The performance of carbon aerogels in the latter two applications depends on the permeability or gas flow conductance in these materials. By measuring the pressure differential across a thin specimen and the nitrogen gas flow rate in the viscous regime, the permeability of carbon aerogels was calculated from equations based upon Darcy's law. Our measurements show that carbon aerogels have permeabilities on the order of 10[sup [minus]12] to 10[sup [minus]10] cm[sup 2] over the density range from 0.05--0.44 g/cm[sup 3]. Like many other aerogel properties, the permeability of carbon aerogels follows a power law relationship with density, reflecting differences in the average mesopore size. Comparing the results from this study with the permeability of silica aerogels reported by other workers, we found that the permeability of aerogels is governed by a simple universal flow equation. This paper discusses the relationship between permeability, pore size, and density in carbon aerogels.

Kong, F.; LeMay, J.D.; Hulsey, S.S.; Alviso, C.T.; Pekala, R.W. (Chemistry and Materials Science Department, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States))

1993-12-01

436

Ocean uptake of carbon dioxide  

SciTech Connect

Factors controlling the capacity of the ocean for taking up anthropogenic C0[sup 2] include carbon chemistry, distribution of alkalinity, pCO[sup 2] and total concentration of dissolved C0[sup 2], sea-air pCO[sup 2] difference, gas exchange rate across the sea-air interface, biological carbon pump, ocean water circulation and mixing, and dissolution of carbonate in deep sea sediments. A general review of these processes is given and models of ocean-atmosphere system based on our understanding of these regulating processes axe used to estimate the magnitude of C0[sup 2] uptake by the ocean. We conclude that the ocean can absorb up to 35% of the fossil fuel emission. Direct measurements show that 55% Of C0[sup 2] from fossil fuel burning remains in the atmosphere. The remaining 10% is not accounted for by atmospheric increases and ocean uptake. In addition, it is estimated that an amount equivalent to 30% of recent annual fossil fuel emissions is released into the atmosphere as a result of deforestation and farming. To balance global carbon budget, a sizable carbon sink besides the ocean is needed. Storage of carbon in terrestrial biosphere as a result of C0[sup 2] fertilization is a potential candidate for such missing carbon sinks.

Peng, Tsung-Hung (Oak Ridge National Lab., TN (United States)); Takahashi, Taro (Columbia Univ., Palisades, NY (United States). Lamont-Doherty Earth Observatory)

1993-01-01

437

TYPE Ia SUPERNOVA CARBON FOOTPRINTS  

SciTech Connect

We present convincing evidence of unburned carbon at photospheric velocities in new observations of five Type Ia supernovae (SNe Ia) obtained by the Nearby Supernova Factory. These SNe are identified by examining 346 spectra from 124 SNe obtained before +2.5 days relative to maximum. Detections are based on the presence of relatively strong C II {lambda}6580 absorption 'notches' in multiple spectra of each SN, aided by automated fitting with the SYNAPPS code. Four of the five SNe in question are otherwise spectroscopically unremarkable, with ions and ejection velocities typical of SNe Ia, but spectra of the fifth exhibit high-velocity (v > 20, 000 km s{sup -1}) Si II and Ca II features. On the other hand, the light curve properties are preferentially grouped, strongly suggesting a connection between carbon-positivity and broadband light curve/color behavior: three of the five have relatively narrow light curves but also blue colors and a fourth may be a dust-reddened member of this family. Accounting for signal to noise and phase, we estimate that 22{sup +10}{sub -6%} of SNe Ia exhibit spectroscopic C II signatures as late as -5 days with respect to maximum. We place these new objects in the context of previously recognized carbon-positive SNe Ia and consider reasonable scenarios seeking to explain a physical connection between light curve properties and the presence of photospheric carbon. We also examine the detailed evolution of the detected carbon signatures and the surrounding wavelength regions to shed light on the distribution of carbon in the ejecta. Our ability to reconstruct the C II {lambda}6580 feature in detail under the assumption of purely spherical symmetry casts doubt on a 'carbon blobs' hypothesis, but does not rule out all asymmetric models. A low volume filling factor for carbon, combined with line-of-sight effects, seems unlikely to explain the scarcity of detected carbon in SNe Ia by itself.

Thomas, R. C.; Nugent, P. [Computational Cosmology Center, Computational Research Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road MS 50B-4206, Berkeley, CA 94611 (United States); Aldering, G.; Aragon, C.; Bailey, S.; Childress, M.; Fakhouri, H. K.; Hsiao, E. Y.; Loken, S. [Physics Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Antilogus, P.; Bongard, S.; Canto, A. [Laboratoire de Physique Nucleaire et des Hautes Energies, Universite Pierre et Marie Curie Paris 6, Universite Paris Diderot Paris 7, CNRS-IN2P3, 4 place Jussieu, 75252 Paris Cedex 05 (France); Baltay, C. [Department of Physics, Yale University, New Haven, CT 06250-8121 (United States); Buton, C.; Kerschhaggl, M.; Kowalski, M.; Paech, K. [Physikalisches Institut, Universitaet Bonn, Nussallee 12, 53115 Bonn (Germany); Chotard, N.; Copin, Y.; Gangler, E. [Universite de Lyon, F-69622 Lyon (France); and others

2011-12-10

438

Current and relic carbon using natural abundance carbon-13  

SciTech Connect

The role of agricultural practices on soil carbon (C) dynamics is critical to improved soil management. The main objective was to examine the C interactions resulting from crop changes under different tillage and residue treatments.

layse,MF; Clapp,CE; Allmaras,RR; Linden,D.R; Molina, JAE.; Copeland,SM; Dowdy,RH

2002-05-01

439

Measuring supply chain carbon efficiency : a carbon label framework  

E-print Network

In the near term, efficiency improvements represent a key option for reducing the impacts of climate change. The growing awareness of climate change has increased the attention regarding the carbon emissions "embedded" in ...

Craig, Anthony (Anthony J.)

2012-01-01

440

Carbon dioxide solubility and carbon isotope fractionation in basaltic melt  

SciTech Connect

Carbon dioxide solubility and isotope fractionation data for a MORB composition at 1,200-1,400C and 5-20 kbar have been obtained using piston-cylinder apparatus and stepped-heating mass spectrometry. Carbon dioxide solubility in basalt melt at 5, 10 and 20 kbar is 0.15-0.17%, 0.45-0.51%, and 1.49%, respectively. Values for {Delta}Co{sub 2}(vap) - CO 2/3{sup {minus}} (basalt melt), obtained from the difference between the isotopic compositions for coexisting vapor and melt, vary from 1.8% to 2.2%. A review of measured and estimated values for carbon isotope fractionation between CO{sub 2} vapor and carbon dissolved in basic melts shows variation from 1.8% to 4.6%. Results of this study and other considerations favor relatively small equilibrium CO{sub 2} vapor melt fractionation factors around 2%.

Mattey, D.P. (Univ. of London, Egham Hill (United Kingdom) Univ. of Tasmania, Hobart (Australia))

1991-11-01

441

Atmospheric carbon dioxide and the global carbon cycle  

SciTech Connect

This state-of-the-art volume presents discussions on the global cycle of carbon, the dynamic balance among global atmospheric CO2 sources and sinks. Separate abstracts have been prepared for the individual papers. (ACR)

Trabalka, J R [ed.

1985-12-01

442

Modern carbonate mound systems  

NASA Astrophysics Data System (ADS)

Carbonate mounds are prominent features throughout the geological record. In many hydrocarbon provinces, they form prime reservoir structures. But recent investigations have increasingly reported occurrences of large mound clusters at the surface of the seabed, or buried at shallow depth on modern ocean margins, and in particular in basins rich in hydrocarbons. Such exciting new observations along the West-European margin are promising for elucidating the setting and environment of modern carbonate mounds, but at the same time they confront us with puzzling or sometimes contradictory observations in the quest for their genesis. Spectacular cold-water coral communities have colonized such mounds, but convincing arguments for recognizing them as prime builders are still lacking. The geological record provides ample evidence of microbial mediation in mound build-up and stabilisation, but as long as mound drilling is lacking, we have no opportunity to verify the role of such processes and identify the key actors in the earliest stage of onset and development of modern mounds. Some evidence from the past record and from present very-high resolution observations in the shallow seabed suggest an initial control by fluid venting, and fluid migration pathways have been imaged or are tentatively reconstructed by modelling in the concerned basins, but the ultimate link in the shallow subsurface seems still to elude a large part of our efforts. Surface sampling and analyses of both corals and surface sediments have largely failed in giving any conclusive evidence of present-day or recent venting in the considered basins. But on the other hand, applying rigourously the interpretational keys derived from e.g. Porcupine Seabight settings off NW Ireland on brand new prospective settings e.g. on the Moroccan margin have resulted in the discovery of totally new mound settings, in the middle of a field of giant, active mud volcanoes. Keys are apparently working, but we still do not understand how or why. We are no doubt facing complex systems at the interface between the Biosphere and the Geosphere, owing their genesis and spectacular growth to a complex woven of internal and external controls, feedback and process relay processes.

Henriet, J. P.; Dullo, C.

2003-04-01

443

Seventh International Carbon Dioxide Conference  

NSDL National Science Digital Library

Organized by NOAA's Climate Monitoring and Diagnostic Laboratory (CMDL), the Seventh International Carbon Dioxide Conference is planned September 25-30 in Broomfield, Colo. At this website, scientists involved in various aspects of the global carbon cycle, especially the current increases of carbon dioxide in the atmosphere, are encouraged to attend. Users can read the preliminary announcement and can learn about the themes of the conference. Researchers can learn about abstract submissions and accommodations. The Brief Conference History link offers a nice synopsis of the accomplishments of past conferences.

444

Carbonate chemistry of the Caribbean  

E-print Network

dissociation constant is the product of the activities of the substances produced at equilibrium in a chemical reaction divided by the product of the activities of the reacting substances. I 1 The dissociation constants of boric (K ) and carbonic acid (K B...] K [HSBO4] (S) where a O is the activity of water, a O is the activity of CO2, "2' C02 [H&BO4] is the concentration of boric acid, Kl is the first carbonic 'I acid dissociation constant, K2 is the second carbonic acid disso- ciation constant...

Carlson, Tonalee

2012-06-07

445

Carbon Markets and Technological Innovation  

E-print Network

the carbon market is bypassed by the regulator, who offers an ex-ante unlimited number of carbon emissions permits at the fixed price of ? . (ii) A pure carbon emissions cap of E is also a special case, which can be implemented by setting R = (E, 0... characterizes the behavior of the solution in ?. Since this paper provides several such monotone comparative statics results, we provide the proof intuition. The proofs of other such results (cf. Proposition 1 (ii) and Proposition 4 (ii),(iii)) follow along...

Weber, T A; Neuhoff, Karsten

446

Aluminum-carbon composite electrode  

DOEpatents

A high performance double layer capacitor having an electric double layer formed in the interface between activated carbon and an electrolyte is disclosed. The high performance double layer capacitor includes a pair of aluminum impregnated carbon composite electrodes having an evenly distributed and continuous path of aluminum impregnated within an activated carbon fiber preform saturated with a high performance electrolytic solution. The high performance double layer capacitor is capable of delivering at least 5 Wh/kg of useful energy at power ratings of at least 600 W/kg.

Farahmandi, C. Joseph (Auburn, AL); Dispennette, John M. (Auburn, AL)

1998-07-07

447

Aluminum-carbon composite electrode  

DOEpatents

A high performance double layer capacitor having an electric double layer formed in the interface between activated carbon and an electrolyte is disclosed. The high performance double layer capacitor includes a pair of aluminum impregnated carbon composite electrodes having an evenly distributed and continuous path of aluminum impregnated within an activated carbon fiber preform saturated with a high performance electrolytic solution. The high performance double layer capacitor is capable of delivering at least 5 Wh/kg of useful energy at power ratings of at least 600 W/kg. 3 figs.

Farahmandi, C.J.; Dispennette, J.M.

1998-07-07

448

The Orbiting Carbon Observatory (OCO)  

NASA Technical Reports Server (NTRS)

CO2 is the principal human generated driver of climate change. Accurate forecasting of future climate requires an improved understanding of the global carbon cycle and its interaction with the climate system. The Orbiting Carbon Observatory (OCO) will make global, space-based observations of atmospheric CO2 with the precision, resolution, and coverage needed to understand sources and sinks. OCO data will provide critical information for decision makers including the scientific basis for policy formulation, guide for carbon management strategies and treaty monitoring.

Miller, Charles E.

2005-01-01

449

Recalcitrant dissolved organic carbon fractions.  

PubMed

Marine dissolved organic carbon (DOC) exhibits a spectrum of reactivity, from very fast turnover of the most bioavailable forms in the surface ocean to long-lived materials circulating within the ocean abyss. These disparate reactivities group DOC by fractions with distinctive functions in the cycling of carbon, ranging from support of the microbial loop to involvement in the biological pump to a hypothesized major source/sink of atmospheric CO(2) driving paleoclimate variability. Here, the major fractions constituting the global ocean's recalcitrant DOC pool are quantitatively and qualitatively characterized with reference to their roles in carbon biogeochemistry. A nomenclature for the fractions is proposed based on those roles. PMID:22881353

Hansell, Dennis A

2013-01-01

450

Molecular Structure of Carbon tetrachloride  

NSDL National Science Digital Library

Carbon tetrachloride was first prepared in 1839. It was discovered by German-born French scientist Henri Victor Regnault during his work with ether/chlorine reactions. Carbon tetrachloride is a clear, heavy, poisonous, nonflammable liquid with a strong ethereal odor. It is also fairly common as a colorless gas. Carbon tetrachloride is used for dry cleaning, degreasing metals, fumigating, manufacturing refrigerants and aerosol propellants, and is also used in fire extinguishers. CCl4 is a possible carcinogen; inhalation or ingestion can cause damage to the brain, liver, kidneys, and can even cause death. CCl4 also contributes to ozone layer depletion.

2002-08-15

451

Carbon nanotubes in hyperthermia therapy  

PubMed Central

Thermal tumor ablation therapies are being developed with a variety of nanomaterials, including single-and multiwalled carbon nanotubes. Carbon nanotubes (CNTs) have attracted interest due to their potential for simultaneous imaging and therapy. In this review, we highlight in vivo applications of carbon nanotube-mediated thermal therapy (CNMTT) and examine the rationale for use of this treatment in recurrent tumors or those resistant to conventional cancer therapies. Additionally, we discuss strategies to localize and enhance the cancer selectivity of this treatment and briefly examine issues relating the toxicity and long term fate of CNTs. PMID:23933617

Singh, Ravi; Torti, Suzy V.

2013-01-01

452

Deciphering Carbon Isotope Excursions in Separated Biogenic and Diagenetic Carbonates  

Microsoft Academic Search

The long-term evolution of the carbon-isotope ratio in the sedimentary archive is classically linked with changes in primary productivity and organic matter burial. There have been sudden and pronounced shifts, so-called Carbon Isotope Excursions (CIEs) in the long-term trends as evidenced by synchronous shifts from various basins. These geochemical perturbations may have various explanations such as changes of the efficiency

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

2008-01-01

453

Protective glass coating for carbon-carbon composites  

Microsoft Academic Search

An oxidation-protective, self-sealing borosilicate glass (SABB) coating was deposited on a carbon-carbon composite (C\\/C) using a simple and low cost method. The wettability of the glass on the composite was promoted by the formation of a 5–10 ?m ?-SiC layer on the composite surface, by direct reaction of liquid silicon with the C\\/C. The glass coating was thermochemically stable at

C. Isola; P. Appendino; F. Bosco; M. Ferraris; M. Salvo

1998-01-01

454

Oxidation protection for 3D carbon\\/carbon composites  

Microsoft Academic Search

The main objective of this study is to produce an effective protection coating for 3D carbon\\/carbon composites (C\\/C) to prevent oxygen attacks at elevated temperatures. Silicon and zirconium base alloys were used to stack a multilayer coating in an array of elemental gradients. The oxidation rate was detected by an in situ measurement at various temperatures as well as by

Shu-En Hsu; Huan-Der Wu; Tsung-Ming Wu; Shian-Tsong Chou; Kung-Long Wang; Chung-I Chen

1995-01-01

455

Study of fluorhydroxyapatite coatings on carbon\\/carbon composites  

Microsoft Academic Search

Fluorhydroxyapatite coatings were prepared on the surface of carbon\\/carbon composites using the combined action of ultrasonic-electrodeposition and ion exchange. The morphology, structure and composition of the prepared coatings after ion exchange were investigated by scanning electron microscopy, X-ray energy spectrum analysis, infrared spectroscopy and X-ray diffraction. Results show that the crystallinity of the coating as well as the intensity of

Chuang Wang; Ke-zhi Li; Yan-qiang Zhai; He-jun Li; Jun-long Wang; Geng-sheng Jiao

2009-01-01

456

As-Fabricated Reinforced Carbon/Carbon Characterized  

NASA Technical Reports Server (NTRS)

Reinforced carbon/carbon (RCC) is a critical material for the space shuttle orbiter. It is used on the wing leading edge and the nose cap, where maximum temperatures are reached on reentry. The existing leading-edge system is a single-plate RCC composite construction with a wall thickness of approximately 1/4 in., making it a prime reliant protection scheme for vehicle operation.

Jacobson, Nathan S.; Calomino, Anthony M.; Webster, Neal

2004-01-01

457

THERMAL STRESSES IN COATINGS ON CARBON-CARBON COMPOSITES  

Microsoft Academic Search

A finite-element model for the analysis of thermal stresses in oxidation-protecting coatings on carbon-carbon composites is developed. The model is based on an incremental formulation of the generalized plane deformation theory and allows for temperature-dependent material properties, and the application of coatings at different temperatures. Emphasis is on the determination of stresses in the coatings near a geometric discontinuity, such

A. W. Obst; M. W. Hyer; W. L. Vaughn

1998-01-01

458

Oxidation protective multilayer coatings for carbon–carbon composites  

Microsoft Academic Search

An oxidation protective double layered coating was deposited on a carbon–carbon composite (C\\/C) using a simple and low cost method. A surface modification of the C\\/C was obtained by direct reaction of liquid silicon with the C\\/C, promoting the formation of a 5–10 ?m ?-SiC layer on the composite surface. The inner layer, in contact with the C\\/C, is a

F. Smeacetto; M. Salvo; M. Ferraris

2002-01-01

459

New NDE method for coated carbon-carbon composites  

Microsoft Academic Search

This document describes a nondestructive technique for detecting and repairing surface flaws in the silicon carbide oxidation-resistant-coating of a carbon-carbon composite. The surface of the composite is treated with a test liquid consisting essentially of a carrier fluid, a particulate pigment and a finely divided borosilicate glass, or a mixture of silicon dioxide and boron oxide, containing 0.25 to 8

1985-01-01

460

Encapsulation of lanthanum carbide in carbon nanotubes and carbon nanoparticles  

Microsoft Academic Search

The morphologies of lanthanum-filled carbon nanotubes and nanoparticles, made by arc-discharging carbon-La2O3 composites, were examined with high-resolution transmission electron microscopy and selected-area electron diffraction technique. The HRTEM images and corresponding SARD patterns obtained from the arc-discharge product confirmed that ?-LaC2 nanocrystals, most of which are single crystals, had been formed within the nanotubes and nanoparticles. The encapsulated ?-LaC2 crystals showed

Mingqui Liu; John M. Cowley

1995-01-01

461

Eddy current testing of carbon-carbon composites  

NASA Astrophysics Data System (ADS)

A noncontact electromagnetic measuring system for conductivity monitoring in carbon-carbon composites and similar refractory materials at elevated temperatures is demonstrated. It was verified in the case of thin sheets of test material that the frequency of the peak eddy current dissipation was inversely proportional to the product of the thickness and conductivity. Hysteresis on heating and cooling was noted to be greatest in the early runs up to the lower maximum temperatures; after heating above 800 C, the hysteresis disappeared.

Gvishi, M.; Kahn, A. H.; Mester, M. L.

462

The Dynamic Fracture Toughness of Carbon-Carbon Composites  

Microsoft Academic Search

The dynamic fracture toughness of two types of carbon-carbon com posites (filament wound and felt substrate) and ATJ-S graphite was deter mined from instrumented Charpy impact tests. The resistance to crack initiation from a pre-existing flaw (notch) was examined by investigating the dynamic fracture toughness, KD, a linear elastic fracture mechanics parameter. The resistance to crack initiation and propagation was

W. R. Hoover; T. R. Guess

1973-01-01

463

Porous carbon-carbon composites for fuel cells  

Microsoft Academic Search

Technology for fabricating porous current-conducting gas-diffusion supports for fuel element electrodes made of carbon-carbon\\u000a composites with the structure of fabrics, knits, and nonwovens was developed. The process scheme for manufacturing gas-diffusion\\u000a electrodes for fuel cells was examined. The properties of the gas-diffusion supports manufactured with the technology of the\\u000a St. Petersburg State University of Technology and Design and supports from

A. A. Tarasenko; A. A. Lysenko; V. A. Lysenko

2007-01-01

464

Carbon isotopes in biological carbonates: Respiration and photosynthesis  

USGS Publications Warehouse

Respired carbon dioxide is an important constituent in the carbonates of most air breathing animals but is much less important in the carbonates of most aquatic animals. This difference is illustrated using carbon isotope data from freshwater and terrestrial snails, ahermatypic corals, and chemoautotrophic and methanotrophic pelecypods. Literature data from fish otoliths and bird and mammal shell and bone carbonates are also considered. Environmental CO2/O2 ratios appear to be the major controlling variable. Atmospheric CO2/O2 ratios are about thirty times lower than in most natural waters, hence air breathing animals absorb less environmental CO2 in the course of obtaining O2. Tissue CO2 therefore, does not isotopically equilibrate with environmental CO2 as thoroughly in air breathers as in aquatic animals, and this is reflected in skeletal carbonates. Animals having efficient oxygen transport systems, such as vertebrates, also accumulate more respired CO2 in their tissues. Photosynthetic corals calcify mainly during the daytime when photosynthetic CO2 uptake is several times faster than respiratory CO2 release. Photosynthesis, therefore, affects skeletal ??13C more strongly than does respiration. Corals also illustrate how "metabolic" effects on skeletal isotopic composition can be estimated, despite the presence of much larger "kinetic" isotope effects. Copyright ?? 1997 Elsevier Science Ltd.

McConnaughey, T.A.; Burdett, J.; Whelan, J.F.; Paull, C.K.

1997-01-01

465

Engineering carbon materials from the hydrothermal carbonization process of biomass.  

PubMed

Energy shortage, environmental crisis, and developing customer demands have driven people to find facile, low-cost, environmentally friendly, and nontoxic routes to produce novel functional materials that can be commercialized in the near future. Amongst various techniques, the hydrothermal carbonization (HTC) process of biomass (either of isolated carbohydrates or crude plants) is a promising candidate for the synthesis of novel carbon-based materials with a wide variety of potential applications. In this Review, we will discuss various synthetic routes towards such novel carbon-based materials or composites via the HTC process of biomass. Furthermore, factors that influence the carbonization process will be analyzed and the special chemical/physical properties of the final products will be discussed. Despite the lack of a clear mechanism, these novel carbonaceous materials have already shown promising applications in many fields such as carbon fixation, water purification, fuel cell catalysis, energy storage, CO(2) sequestration, bioimaging, drug delivery, and gas sensors. Some of the most promising examples will also be discussed here, demonstrating that the HTC process can rationally design a rich family of carbonaceous and hybrid functional carbon materials with important applications in a sustainable fashion. PMID:20217791

Hu, Bo; Wang, Kan; Wu, Liheng; Yu, Shu-Hong; Antonietti, Markus; Titirici, Maria-Magdalena

2010-02-16

466

Carbon-carbon turbopump concept for Space Nuclear Thermal Propulsion  

SciTech Connect

The U.S. Air Force Space Nuclear Thermal Propulsion (SNTP) program is placing high priority on maximizing specific impulse (ISP) and thrust-to-weight ratio in the development of a practical high-performance nuclear rocket. The turbopump design is driven by these goals. The liquid hydrogen propellant is pressurized and pumped to the reactor inlet by the turbopump assembly (TPA). Rocket propulsion is from rapid heating of the propellant from 180 R to thousands of degrees in the particle bed reactor (PBR). The exhausted propellant is then expanded through a high-temperature nozzle. A high-performance approach is to use an uncooled carbon-carbon nozzle and duct turbine inlet. Carbon-carbon components are used throughout the TPA hot section to obtain the high-temperature capability. Several carbon-carbon components are in development including structural parts, turbine nozzles/stators, and turbine rotors. The technology spinoff is applicable to conventional liquid propulsion engines and many other turbomachinery applications. 3 refs.

Overholt, D.M.

1993-06-01

467

Howell, R.A., 2012 Living with a carbon allowance 1 Living with a carbon allowance: the experiences of Carbon  

E-print Network

', their experiences of reducing fossil fuel energy use, and their views on personal carbon trading at CRAG government's 2007 energy white paper attributes 42% of UK carbon dioxide (CO2) emissions directlyHowell, R.A., 2012 Living with a carbon allowance 1 Living with a carbon allowance: the experiences

468

Dopamine as a Carbon Source: The Controlled Synthesis of Hollow Carbon Spheres and Yolk-Structured Carbon Nanocomposites  

SciTech Connect

A facile and versatile synthesis using dopamine as a carbon source gives hollow carbon spheres and yolk-shell Au{at}Carbon nanocomposites. The uniform nature of dopamine coatings and their high carbon yield endow the products with high structural integrity. The Au{at}C nanocomposites are catalytically active.

Dai, Sheng [ORNL; Liu, Rui [ORNL; Mahurin, Shannon Mark [ORNL; Li, Chen [ORNL; Unocic, Raymond R [ORNL; Idrobo Tapia, Juan C [ORNL; Gao, Hongjun [ORNL; Pennycook, Stephen J [ORNL

2011-01-01

469

Carbon Nanotube Actuators  

NASA Astrophysics Data System (ADS)

We have demonstrated a new type of electromechanical actuator, which is based on both a new type of actuator material (single-wall carbon nanotubes) and a new type of actuation mechanism (double-layer charge injection). Like natural muscles, the macroscopic actuators are assemblies of billions of individual nanoscale actuators. Higher stress generation capabilities than natural muscles and higher strains than high modulus ceramics were obtained in investigations of both all-solid-state and liquid-electrolyte-based devices. Evidence of giant charge injection is provided by in-situ measurements of electrochemical voltametry and Raman, UV-visible, and impedance spectroscopies. The results of ab initio quantum chemical calculations show that actuation arises from bond length changes that principally originate from quantum chemical effects, rather than electrostatic effects. Based on analysis of measurements, we conclude that nanotube actuators will eventually provide much higher specific work capacities and stress generation capabilities than alternative technologies, while operating at an order of magnitude lower voltages than ferroelectrics. We have demonstrated device operation to above 650 K, and conclude (based on observations of redox stability) that actuator operation to above 1300 K will eventually be feasible.

Baughman, Ray H.

2000-03-01

470

Letters to the editor / Carbon 40 (2002) 445467 447 using continuous carbon-fiber carbon-matrix and polymeruntreated fibers are used. The activation treatment does not  

E-print Network

, Khastgir D. Electro- magnetic interference shielding by carbon black and carbon fibre filled rubber 2001 Keywords: A. Carbon black; Carbon filaments; Electrodes; Mesophase pitch; D. Electrical properties conduc- without graphitization, and carbon black. These types of tive nature of carbons, carbon is used

Chung, Deborah D.L.

471

THERMAL REGENERATION OF ACTIVATED CARBON  

EPA Science Inventory

Ecologically, petrochemical wastes constitute a major hazard since waste materials contain relatively large amounts of non-biodegradable and toxic materials which may be discharged continuously. A three-part experimental study of activated carbon adsorption and thermal regenerati...

472

Photodecomposition of Carbonates on Mars  

NASA Technical Reports Server (NTRS)

We report on experimental investigations of the photo-induced decomposition of calcium carbonate in both a simulated martian atmosphere and under high vacuum. Additional information is contained in the original extended abstract.

Quinn, R. C.; Zent, A. P.; McKay, C. P.

2001-01-01

473

Tertiary carbonate reservoirs in Indonesia  

SciTech Connect

Hydrocarbon production from Tertiary carbonate reservoirs accounted for ca. 10% of daily Indonesian production at the beginning of 1978. Environmentally, the reservoirs appear as parts of reef complexes and high-energy carbonate deposits within basinal areas situated mainly in the back arc of the archipelago. Good porosities of the reservoirs are represented by vugular/moldic and intergranular porosity types. The reservoirs are capable of producing prolific amounts of hydrocarbons: production tests in Salawati-Irian Jaya reaches maximum values of 32,000 bpd, and in Arun-North Sumatra tests recorded 200 MMCF gas/day. Significant hydrocarbon accumulations are related to good reservoir rocks in carbonates deposited as patch reefs, pinnacle reefs, and platform complexes. Exploration efforts expand continuously within carbonate formations which are extensive horizontally as well as vertically in the Tertiary stratigraphic column.

Nayoan, G.A.S.; Arpandi; Siregar, M.

1981-01-01

474

Magnesite disposal of carbon dioxide  

SciTech Connect

In this paper we report our progress on developing a method for carbon dioxide disposal whose purpose it is to maintain coal energy competitive even is environmental and political pressures will require a drastic reduction in carbon dioxide emissions. In contrast to most other methods, our approach is not aiming at a partial solution of the problem, or at buying time for phasing out fossil energy. Instead, its purpose is to obtain a complete and economic solution of the problem, and thus maintain access to the vast fossil energy reservoir. A successful development of this technology would guarantee energy availability for many centuries even if world economic growth the most optimistic estimates that have been put forward. Our approach differs from all others in that we are developing an industrial process which chemically binds the carbon dioxide in an exothermic reaction into a mineral carbonate that is thermodynamically stable and environmentally benign.

Lackner, K.S.; Butt, D.P.; Wendt, C.H.

1997-08-01

475

Research Report Forests and carbon  

E-print Network

Fix Standard (CFS) Climate, Community and Biodiversity Standard (CCBS) Forest Carbon Standard (FCS) Gold establishing a `business as usual' baseline. This requires deter- mining a counterfactual for what would have

476

A comparison of carbon calculators  

SciTech Connect

International attention to carbon dioxide emissions is turning to an individual's contribution, or 'carbon footprint.' Calculators that estimate an individual's CO{sub 2} emissions have become more prevalent on the internet. Even with similar inputs, however, these calculators can generate varying results, often by as much as several metric tons per annum per individual activity. This paper examines the similarities and differences among ten US-based calculators. Overall, the calculators lack consistency, especially for estimates of CO{sub 2} emissions from household electricity consumption. In addition, most calculators lack information about their methods and estimates, which impedes comparison and validation. Although carbon calculators can promote public awareness of carbon emissions from individual behavior, this paper reveals the need for improved consistency and transparency in the calculators.

Padgett, J. Paul [Vanderbilt University, VU Station B351831, Nashville, TN 37235 (United States)], E-mail: joseph.p.padgett@vanderbilt.edu; Steinemann, Anne C. [University of Washington, Mail Code 352700, Wilson Lab 103, Seattle, WA 98195-2700 (United States)], E-mail: acstein@u.washington.edu; Clarke, James H. [Vanderbilt University, VU Station B351831, Nashville, TN 37235 (United States)], E-mail: james.h.clarke@vanderbilt.edu; Vandenbergh, Michael P. [Vanderbilt University, VU Station B351831, Nashville, TN 37235 (United States)], E-mail: michael.vandenbergh@law.vanderbilt.edu

2008-02-15

477

Activated carbon gets revved up  

SciTech Connect

When it comes to adsorption, few products can match the low cost and efficient performance of activated carbon. That`s why the material is so widely used for wastewater treatment. But with processors looking for economical ways to achieve environmental compliance in other operations, the market s taking off in different directions, wit much attention focused on air purification, process water treatment and solvent recovery. It is the opportunity that manufacturers and marketers of activated carbon have been waiting for. All revved up, they are generating new products and regenerating spent carbon, and rounding out their offerings with equipment and technical service. The article discusses new products and applications, increasing regeneration capacity, and competition in the activated carbon industry.

Hairston, D.

1995-11-01

478

Carbon Capture and Geologic Storage  

NASA Astrophysics Data System (ADS)

This paper will briefly discuss carbon capture and storage options, mechanisms and costs. Risks from geologic storage risks will be addressed and the need for monitoring. Some current field studies will be described.

Myer, Larry R.

2008-09-01

479

Sulfur-Functionalized Mesoporous Carbon  

SciTech Connect

A simple, direct synthesis of mesoporous carbons containing heteroaromatic functionality is described. Superior performance of these mesoporous heterocarbons as heavy metal sorbent material is demonstrated. These materials are shown to be stable towards elevated temperatures and extreme pHs.

Shin, Yongsoon; Fryxell, Glen E.; Um, Wooyong; Parker, Kent E.; Mattigod, Shas V.; Skaggs, Richard

2007-10-15

480

Carbon Fiber Risk Analysis: Conclusions  

NASA Technical Reports Server (NTRS)

It was concluded that preliminary estimates indicate that the public risk due to accidental release of carbon fiber from air transport aircraft is small. It was also concluded that further work is required to increase confidence in these estimates.

Huston, R. J.

1979-01-01

481

Carbon-assisted flyer plates  

DOEpatents

A laser driven flyer plate is described utilizing an optical fiber connected to a laser. The end of the optical fiber has a layer of carbon and a metal layer deposited onto it. The carbon layer provides the laser induced plasma which is superior to the plasma produced from most metals. The carbon layer plasma is capable of providing a flatter flyer plate, converting more of the laser energy to driving plasma, promoting a higher flyer plate acceleration, and providing a more uniform pulse behind the plate. In another embodiment, the laser is in optical communication with a substrate onto which a layer of carbon and a layer of metal have been deposited. 2 figures.

Stahl, D.B.; Paisley, D.L.

1994-04-12

482

Non-carbon induction furnace  

DOEpatents

The present invention is directed to an induction furnace for melting and casting highly pure metals and alloys such as uranium and uranium alloys in such a manner as to minimize contamination of the melt by carbon derived from the materials and the environment within the furnace. The subject furnace is constructed of non-carbon materials and is housed within a conventional vacuum chamber. The furnace comprises a ceramic oxide crucible for holding the charge of metal or alloys. The heating of the crucible is achieved by a plasma-sprayed tungsten susceptor surrounding the crucible which, in turn, is heated by an rf induction coil separated from the susceptor by a cylinder of inorganic insulation. The furnace of the present invention is capable of being rapidly cycled from ambient temperatures to about 1650/sup 0/C for effectively melting uranium and uranium alloys without the attendant carbon contamination problems previously encountered when using carbon-bearing furnace materials.

Holcombe, C.E.; Masters, D.R.; Pfeiler, W.A.

1984-01-06

483

Carbon Dioxide and Ocean Acidification  

NSDL National Science Digital Library

Demonstrates the affect of increased dissolved carbon dioxide on water pH using a cheap, non-toxic acid/base indicator. Students bubble breath through a straw into red cabbage juice and note the color change.

Lewis, Chris

484

Carbon-free induction furnace  

DOEpatents

An induction furnace for melting and casting highly pure metals and alloys such as uranium and uranium alloys in such a manner as to minimize contamination of the melt by carbon derived from the materials and the environment within the furnace. The subject furnace is constructed of carbon free materials and is housed within a conventional vacuum chamber. The furnace comprises a ceramic oxide crucible for holding the charge of metal or alloy. The heating of the crucible is achieved by a plasma-sprayed tungsten susceptor surrounding the crucible which, in turn, is heated by an RF induction coil separated from the susceptor by a cylinder of inorganic insulation. The furnace of the present invention is capable of being rapidly cycled from ambient temperatures to about 1650.degree. C. for effectively melting uranium and uranium alloys without the attendant carbon contamination problems previously encountered when using carbon-bearing furnace materials.

Holcombe, Cressie E. (Knoxville, TN); Masters, David R. (Knoxville, TN); Pfeiler, William A. (Norris, TN)

1985-01-01

485

Emerging Applications of Carbon Nanotubes  

E-print Network

On the basis of their unique electrical and mechanical properties, carbon nanotubes (CNTs) have attracted great attention in recent years. A diverse array of methods has been developed to modify CNTs and to assemble them ...

Schnorr, Jan Markus

486

Fractionation between inorganic and organic carbon during the Lomagundi (2.222.1 Ga) carbon isotope excursion  

E-print Network

April 2008 Editor: H. Elderfield Keywords: Precambrian carbon cycle Lomagundi Event carbon isotope. carbonate carbon isotopic values on the shallow-marine carbonate platform suggests that the carbon cyclingFractionation between inorganic and organic carbon during the Lomagundi (2.22­2.1 Ga) carbon

Bekker, Andrey

487

Stable Carbon and Nitrogen Isotopic  

Microsoft Academic Search

The perennially ice-covered lakes in the McMurdo Dry Valleys, Antarctica, are part of the coldest and driest ecosystem on earth. To understand lacustrine carbon and nitrogen cycling in this end-member ecosystem, and to define paleolimnological proxies for ice-covered lakes, we measured the stable carbon and nitrogen isotopic composition of particulate organic matter (POM) and benthic organic matter (BOM) within the

Jennifer Lawson; PETER T. DORAN; Fabien Kenig; DAVID J. DES MARAIS; JOHN C. PRISCU

2004-01-01

488

Activated carbon to the rescue  

SciTech Connect

This article describes the response to pipeline spill of ethylene dichloride (EDC) on the property of an oil company. Activated carbon cleanup proceedure was used. During delivery, changeout, transport, storage, thermal reactivation, and return delivery to the site, the carbon never came into direct contact with operating personnel or the atmosphere. More than 10,000 tones of dredge soil and 50 million gallons of surface water were processed during the emergency response.

Sen, S. [Calgon Carbon Corp., Pittsburgh, PA (United States)

1996-03-01

489

Carbon storage in Amazonian podzols  

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

490

Carbon Nanotube Array Immunosensor Development  

Microsoft Academic Search

This paper describes the development of a label-free immunosensor using carbon nanotube array electrodes. Highly aligned multi-walled carbon nanotubes were grown by chemical vapor deposition using a metallic catalyst, Fe\\/Al2O3\\/SiO2, On Si wafers. Harvested towers were cast in epoxy and polished on both ends; one end being for electrical connection and the other being the electrode array surface. The nanotubes

A. Bange; H. B. Halsall; W. R. Heineman; YeoHeung Yun; M. J. Schulz; V. Shanov

2006-01-01

491

Carbon Nanotube Electronics and Optoelectronics  

Microsoft Academic Search

Carbon nanotube field-effect transistors (CNFETs) are already competitive in some respects with state-of-the-art silicon transistors,\\u000a and are promising candidates for future nanoelectronic devices. However, it is dificult to form ohmic contacts to carbon nanotubes,\\u000a and most of the CNFETs reported to date operate as Schottky barrier transistors rather than conventional FETs. The electrostatics\\u000a at the contact of a metal to

Stefan Heinze; Jerry Tersoff; Phaedon Avouris

2005-01-01

492

Electronic sputtering of carbon allotropes  

Microsoft Academic Search

Electronic sputtering of different allotropes of carbon (diamond, graphite, fullerene, a-C and a-C:H) are studied under 200 MeV Au15+ ion irradiation. On-line elastic recoil detection analysis (ERDA) and catcher technique is employed to measure the sputtering yield of carbon from these allotropes. Erosion behavior is distinctly different in different allotropes as observed by ERDA. Hardest known material diamond does not

S. Ghosh; D. K Avasthi; A. Tripathi; D. Kabiraj; S. Singh; D. S Misra

2004-01-01

493

Nongovernmental valorization of carbon dioxide  

Microsoft Academic Search

Carbon dioxide (CO2) is considered the largest contributor to the greenhouse gas effect. Most attempts to manage the flow of CO2 or carbon into our environment involve reducing net emissions or sequestering the gas into long-lived sinks. Using CO2 as a chemical feedstock has a long history, but using it on scales that might impact the net emissions of CO2

Gene Petersen; Donn Viviani; Kim Magrini-Bair; Stephen Kelley; Luc Moens; Phil Shepherd; Dan DuBois

2005-01-01

494

Carbon Sequestration in Mine Residue  

NASA Astrophysics Data System (ADS)

Mining of silicate rocks produces as waste a reactive, fine-grained residue that is an ideal feedstock for mineral sequestration of carbon. Natural weathering of Mg-silicate mine tailings is rapid because of the fine grain size, and produces mineral crusts that bind carbon. Stable and radiogenic carbon isotope fingerprinting on the minerals confirms an atmospheric carbon source. In active mines that produce Mg-rich tailings, the carbon sequestration capacity of annual tailings production exceeds annual mine greenhouse gas production by a factor of 5 to 10. Hardrock mines therefore represent an ongoing industrial activity that could serve as a net carbon sink. New cation release rates from inorganic and microbially-mediated mineral dissolution experiments indicate that individual large mining operations could be engineered to sequester carbon dioxide at a rate of 10E4 to 10E6 tonnes per year. Our laboratory experiments also suggest that cyanobacteria could be employed to catalyze precipitation of Mg-carbonate minerals. Mg-silicate tailings are abundant and distributed globally. The global sequestration capacity of annual tailings production from nickel, diamond, platinum group element, and asbestos mining is approximately half a gigatonne of CO2. Parallel, but less efficient mineral sequestration pathways in other silicate tailings increase the sequestration capacity by as much as an order of magnitude. Global implementation of mineral sequestration in mine tailings could contribute as much as one of the seven "wedges" of Pacala and Socolow (2004) that are required to stabilize atmospheric CO2 content over the next 50 years.

Dipple, G. M.; Southam, G.; Power, I.; Thom, J.; Wilson, S.

2005-12-01

495

Escaping carbon lock-in  

Microsoft Academic Search

This article explores the climate policy implications of the arguments made in “Understanding carbon lock-in” (Unruh, 2000), which posited that industrial countries have become locked-into fossil fuel-based energy systems through path dependent processes driven by increasing returns to scale. Carbon lock-in arises through technological, organizational, social and institutional co-evolution, “culminating” in what was termed as techno-institutional complex (TIC). In order

Gregory C. Unruh

2002-01-01

496

PECVD Growth of Carbon Nanotubes  

NASA Technical Reports Server (NTRS)

Plasma enhanced chemical vapor deposition (PECVD), using inductively coupled plasma, has been used to grow carbon nanotubes (CNTs) and graphitic carbon fibers (GCF) on substrates sputtered with aluminum and iron catalyst. The capacitive plasma's power has been shown to cause a transition from nanotubes to nanofibers, depending on the strength of the plasma. The temperature, placement, and other factors have been shown to affect the height and density of the tube and fiber growth.

McAninch, Ian; Arnold, James O. (Technical Monitor)

2001-01-01

497

The Carbon Budget of California  

NASA Astrophysics Data System (ADS)

The carbon budget of a region can be defined as the sum of annual fluxes of carbon dioxide and methane greenhouse gases (GHGs) into and out of the regional surface coverage area. According to the state government’s recent inventory, California's carbon budget is presently dominated by fossil fuel emissions of CO2 (at >85% of total annual GHG emissions) to meet energy and transportation requirements. Other notable (non-ecosystem) sources of carbon GHG emissions in 2004 were from cement- and lime-making industries, livestock-based agriculture, and waste treatment activities. The NASA-CASA (Carnegie Ames Stanford Approach) simulation model based on satellite observations of monthly vegetation cover (including those from the Moderate Resolution Imaging Spectroradiometer - MODIS) has been used to estimate net ecosystem fluxes and vegetation biomass production over the period 1990-2004. California's annual NPP for all ecosystems in the early 2000s, estimated by CASA at 120 million metric tons of carbon equivalent (MMTCE) per year, was roughly equal to its annual fossil fuel emission rates for carbon. However, since natural ecosystems can accumulate only a small fraction of this annual NPP total in long-term storage pools, the net ecosystem sink flux for atmospheric carbon across the state was estimated at a maximum rate of between 15-24 MMTCE per year under favorable precipitation conditions. Under less favorable precipitation conditions, such as those experienced during the early 1990s, ecosystems statewide were estimated to have lost nearly 15 MMTCE per year to the atmosphere. Considering the large amounts of carbon stored in standing biomass of forests, shrublands, and rangelands across the state, the implications of changing climate and land use practices on ecosystems must be factored into the state’s planning to reduce overall GHG emissions.

Potter, C. S.

2009-12-01

498

Carbon nanotubes for orthopaedic implants  

Microsoft Academic Search

The physical and biological limitations of current orthopaedic implant materials are a major challenge for bone tissue engineering.\\u000a Nanotechnology has introduced new materials and methods for meeting this challenge. The application of nanotechnology to engineering\\u000a new bone substitutes finds a model in the nanoscale components of natural bone tissue. Carbon nanotubes are a macromolecular\\u000a form of carbon with exceptional properties

Rose L. Spear; Ruth E. Cameron

2008-01-01

499

Smokeless fuel from carbonized sawdust  

SciTech Connect

Carbonization of sawdust at 538 degrees gave charcoal useful as smokeless fuel; yield and calorific value (CV) of the fuel gas increased when the gases, tar, and pyroligneous liquor from carbonization were subjected to thermal cracking on firebrick, semicoke, or charcoal. When semicoke or charcoal was used, the tar and pyroligneous liquor were completely decomposed and the yield and CV of gaseous products obtained were higher than those obtained by cracking over firebrick.

Chembukulam, S.K.; Dandge, A.S.; Rao, N.L.K.; Seshagiri, K.; Vaidyeswaran, R.

1981-01-01

500

CARBONIZER TESTS WITH LAKELAND FEEDSTOCKS  

SciTech Connect

Research has been conducted under United States Department of Energy Contract (USDOE) DE-AC21-86MC21023 to develop a new type of coal-fired plant for electric power generation. This new type of plant, called a Second Generation Pressurized Fluidized Bed Combustion Plant (2nd Gen PFB), offers the promise of efficiencies greater than 48%, with both emissions and a cost of electricity that are significantly lower than those of conventional pulverized coal-fired (PC) plants with wet flue gas desulfurization/scrubbers. The 2nd Gen PFB plant incorporates the partial gasification of coal in a carbonizer, the combustion of carbonizer char in a pressurized circulating fluidized (PCFB) bed boiler, and the combustion of carbonizer syngas in a topping combustor to achieve gas turbine inlet temperatures of 2700 F and higher. Under the USDOE Clean Coal V Demonstration Plant Program, a nominal 260 MWe plant demonstrating 2nd Gen PFB technology has been proposed for construction at the McIntosh Power Plant of the City of Lakeland, Florida. In the