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1

Yttrium implantation effect on low manganese–carbon steel  

Microsoft Academic Search

Low manganese–carbon steels were implanted with yttrium using the ion implantation method. Compositional and structural analyses were carried out before and after yttrium implantation by several techniques such as Rutherford backscattering spectrometry, X-ray photoelectron spectroscopy, reflection high energy electron diffraction, X-ray diffraction and glancing angle X-ray diffraction to observe the yttrium implantation effect on low manganese–carbon steel.

E Caudron; H Buscail; V. A. C Haanapel; Y. P Jacob; M. F Stroosnijder

2000-01-01

2

Surface modifications induced by yttrium implantation on low manganese–carbon steel  

Microsoft Academic Search

Low manganese–carbon steel samples were ion implanted with yttrium. Sample compositions and structures were investigated before and after yttrium implantations to determine the yttrium distribution in the sample. Yttrium implantation effects were characterized using several analytical and structural techniques such as X-ray photoelectron spectroscopy, reflection high energy electron diffraction, X-ray diffraction, glancing angle X-ray diffraction and Rutherford backscattering spectrometry. In

E Caudron; H Buscail; V. A. C Haanapel; Y. P Jacob; M. F Stroosnijder

1999-01-01

3

Hot corrosion resistances of yttrium-implanted and unimplanted low-manganese–carbon steels  

Microsoft Academic Search

Yttrium-implanted and unimplanted low-manganese–carbon steel samples were analyzed at T=700°C and under an oxygen partial pressure PO2=0.04 Pa for 24 h to observe the yttrium implantation effect on sample hot corrosion resistance. The yttrium implantation effect on low-manganese–carbon steel was investigated using several analytical and structural techniques such as Rutherford backscattering spectrometry (RBS), X-ray photoelectron spectroscopy (XPS), reflection high energy

E Caudron; H Buscail

2000-01-01

4

Fabrication of yttrium aluminum garnet transparent ceramics from yttria nanopowders synthesized by carbonate precipitation  

Microsoft Academic Search

Nanocrystalline yttria powders have been successfully synthesized by using yttrium nitrate as starting salt and ammonium hydrogen\\u000a carbonate as precipitant. It was found that a small amount of ammonia sulfate in the yttrium nitrate solution can effectively\\u000a reduce the agglomeration and the resultant powders display good dispersion. Pure cubic phase yttria powders were prepared\\u000a by calcining the precipitate at 1100 °C

Hua Gong; Dingyuan Tang; Hui Huang; Jan Ma

2009-01-01

5

Dye adsorption on mesoporous activated carbon fiber obtained from pitch containing yttrium complex  

Microsoft Academic Search

The adsorption of acid dyes (Acid Blue 9, Acid Blue 74, Acid Orange 10, and Acid Orange 51), direct dyes (Direct Black 19, Direct Yellow 11, and Direct Yellow 50), and basic dyes (Basic Brown 1 and Basic Violet 3) on a highly mesoporous activated carbon fiber (Y-ACF) obtained from pitch containing yttrium acetylacetonate was investigated in terms of size

Hisashi Tamai; Takeshi Yoshida; Masahiko Sasaki

1999-01-01

6

Comparison of the oxidation resistances of yttrium implanted low manganese and low manganese–carbon steels at high temperature  

Microsoft Academic Search

Yttrium implanted and unimplanted low manganese and low manganese–carbon steel samples were analyzed at T=700°C and under an oxygen partial pressure PO2=0.04 Pa for 24 h to show the yttrium implantation effect on sample high temperature oxidation resistances. Sample oxidation weight gains were studied by thermogravimetry and structural analyses were performed by in-situ high temperature X-ray diffraction (XRD) with the

E. Caudron; H Buscail

2000-01-01

7

The inhibition of neuronal calcium ion channels by trace levels of yttrium released from carbon nanotubes.  

PubMed

Carbon nanotubes (CNTs) are used with increasing frequency in neuroengineering applications. CNT scaffolds are used to transmit electrical stimulation to cultured neurons and to control outgrowth and branching patterns of neurites. CNTs have been reported to disrupt normal neuronal function including alterations in endocytotic capability and inhibition of ion channels. Calcium ion channels regulate numerous neuronal and cellular functions including endo and exocytosis, neurite outgrowth, and gene expression. Strong CNT interactions with neuronal calcium ion channels would have profound biological implications. Here we show that physiological solutions containing CNTs inhibit neuronal voltage-gated calcium ion channels in a dose-dependent and CNT sample-dependent manner with IC50 as low as 1.2 microg/ml. Importantly, we demonstrate that the inhibitory activity does not involve tubular graphene as previously reported, but rather very low concentrations of soluble yttrium released from the nanotube growth catalyst. Cationic yttrium potently inhibits calcium ion channel function with an inhibitory efficacy, IC50, of 0.07 ppm w/w. Because of this potency, unpurified and even some reportedly "purified" CNT samples contain sufficient bioavailable yttrium to inhibit channel function. Our results have important implications for emerging nano-neurotechnology and highlight the critical role that trace components can play in the biological response to complex nanomaterials. PMID:19698989

Jakubek, Lorin M; Marangoudakis, Spiro; Raingo, Jesica; Liu, Xinyuan; Lipscombe, Diane; Hurt, Robert H

2009-10-01

8

High-performance carbon-nanotube-based complementary field-effect-transistors and integrated circuits with yttrium oxide  

NASA Astrophysics Data System (ADS)

High-performance p-type carbon nanotube (CNT) transistors utilizing yttrium oxide as gate dielectric are presented by optimizing oxidization and annealing processes. Complementary metal-oxide-semiconductor (CMOS) field-effect-transistors (FETs) are then fabricated on CNTs, and the p- and n-type devices exhibit symmetrical high performances, especially with low threshold voltage near to zero. The corresponding CMOS CNT inverter is demonstrated to operate at an ultra-low supply voltage down to 0.2 V, while displaying sufficient voltage gain, high noise margin, and low power consumption. Yttrium oxide is proven to be a competitive gate dielectric for constructing high-performance CNT CMOS FETs and integrated circuits.

Liang, Shibo; Zhang, Zhiyong; Si, Jia; Zhong, Donglai; Peng, Lian-Mao

2014-08-01

9

Growth and performance of yttrium oxide as an ideal high-kappa gate dielectric for carbon-based electronics.  

PubMed

High-quality yttrium oxide (Y(2)O(3)) is investigated as an ideal high-kappa gate dielectric for carbon-based electronics through a simple and cheap process. Utilizing the excellent wetting behavior of yttrium on sp(2) carbon framework, ultrathin (about few nm) and uniform Y(2)O(3) layers have been directly grown on the surfaces of carbon nanotube (CNT) and graphene without using noncovalent functionalization layers or introducing large structural distortion and damage. A top-gate CNT field-effect transistor (FET) adopting 5 nm Y(2)O(3) layer as its top-gate dielectric shows excellent device characteristics, including an ideal subthreshold swing of 60 mV/decade (up to the theoretical limit of an ideal FET at room temperature). The high electrical quality Y(2)O(3) dielectric layer has also been integrated into a graphene FET as its top-gate dielectric with a capacitance of up to 1200 nF/cm(2), showing an improvement on the gate efficiency and on state transconductance of over 100 times when compared with that of its back-gate counterpart. PMID:20455575

Wang, Zhenxing; Xu, Huilong; Zhang, Zhiyong; Wang, Sheng; Ding, Li; Zeng, Qingsheng; Yang, Leijing; Pei, Tian; Liang, Xuelei; Gao, Min; Peng, Lian-Mao

2010-06-01

10

In-situ X-ray diffraction study of the behaviour of yttrium implanted low manganese-carbon steel at high temperature  

Microsoft Academic Search

Yttrium implanted and unimplanted low manganese-carbon steel samples were analysed at T=700°C and under oxygen partial pressure (Po2=0.04 Pa) for 24 h to show the yttrium implantation effect on sample oxidation resistance at high temperature. Weight gains resulting from sample oxidation were studied by thermogravimetry and structural analyses were performed by in-situ high temperature X-ray diffraction under the same experimental

E Caudron; H Buscail; R Cueff

2000-01-01

11

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

12

Comparative and quantitative study of neutral debris emanated from tin plasmas produced by neodymium-doped yttrium-aluminum-garnet and carbon dioxide laser pulses  

SciTech Connect

Amount of neutral debris emanated from extreme ultraviolet light source must be minimized to maximize its lifetime. Emanation of neutral atomic debris was experimentally investigated using laser-induced-fluorescence technique for carbon dioxide (CO{sub 2}, 10.6 {mu}m in wavelength) and Nd-doped yttrium-aluminum-garnet (Nd:YAG, 1.064 {mu}m) lasers irradiated tin foils. Total number of neutral atomic debris from CO{sub 2} laser-irradiated tin foils was 1/100 times smaller than that from Nd:YAG irradiated ones. Competitiveness of CO{sub 2} laser was revealed in terms of debris mitigation.

Matsuoka, Yuji; Nakai, Yuki; Fujioka, Shinsuke; Maeda, Shinsuke; Shimomura, Masashi; Nishimura, Hiroaki [Institute of Laser Engineering, Osaka University, 2-6 Yamada-Oka, Osaka 565-0871 (Japan); Shimada, Yoshinori; Sunahara, Atsushi [Institute for Laser Technology, Osaka University, 2-6 Yamada-Oka, Osaka 565-0871 (Japan); Yoshida, Minoru [Department of Electronics and Electronic Engineering, Kinki University, 3-4-1 Kowakae, Osaka 577-8502 (Japan)

2010-09-13

13

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.

14

CoPrecipitation of Double Carbonates of Yttrium and the Rare Earth Elements, Na2xM2(CO3)3+x, from Seawater-Like Electrolyte Solutions  

Microsoft Academic Search

Co-precipitation of mixed carbonates of yttrium and the rare earth elements (YREEs) from perchlorate and chloride solutions at seawater ionic strength (0.7 molal, T = 25°C) was induced by raising pH under an atmosphere of 100% CO2. Solution pH was monitored with a glass combination electrode, and dissolved YREE concentrations by ICP-MS after filtration through 0.2 mum pore size membranes.

J. Schijf; R. H. Byrne

2010-01-01

15

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,

16

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.

Maryland Virtual High School

17

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

18

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

19

Carbon-carbon piston development  

NASA Technical Reports Server (NTRS)

A new piston concept, made of carbon-carbon refractory-composite material, has been developed that overcomes a number of the shortcomings of aluminum pistons. Carbon-carbon material, developed in the early 1960's, is lighter in weight than aluminum, has higher strength and stiffness than aluminum and maintains these properties at temperatures over 2500 F. In addition, carbon-carbon material has a low coefficient of thermal expansion and excellent resistance to thermal shock. An effort, called the Advanced Carbon-Carbon Piston Program was started in 1986 to develop and test carbon-carbon pistons for use in spark ignition engines. The carbon-carbon pistons were designed to be replacements for existing aluminum pistons, using standard piston pin assemblies and using standard rings. Carbon-carbon pistons can potentially enable engines to be more reliable, more efficient and have greater power output. By utilizing the unique characteristics of carbon-carbon material a piston can: (1) have greater resistance to structural damage caused by overheating, lean air-fuel mixture conditions and detonation; (2) be designed to be lighter than an aluminum piston thus, reducing the reciprocating mass of an engine, and (3) be operated in a higher combustion temperature environment without failure.

Gorton, Mark P.

1994-01-01

20

Calcium Carbonate  

MedlinePLUS

Calcium carbonate is a dietary supplement used when the amount of calcium taken in the diet is not ... for healthy bones, muscles, nervous system, and heart. Calcium carbonate also is used as an antacid to relieve ...

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.

Carbon Footprint Ltd

22

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

23

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

24

What is carbon? Carbon is every where  

E-print Network

#12;What is carbon? #12;Carbon is every where #12;Interesting carbon Hardest material Excellent Black solid Cheap and common #12;Why? #12;Why? #12;Carbon family tree Carbon Family tree Carbyne Graphite Diamond 1D 2D 3D Fullerene Carbon nanotube Graphene 0D 1D 2D #12;Carbon nanostructures 1985

Tsymbal, Evgeny Y.

25

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

26

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.

NOAA/Earth System Research Laboratory

27

Cycling Carbon  

NSDL National Science Digital Library

In this experiment, learners will investigate the release of carbon-containing gas from living and nonliving sources. Learners scratch the surface of a limestone rock and observe what happens when they place a few drops of vinegar on the scratched area. Next, learners observe what happens when they release carbon dioxide from a balloon into a beaker with Bromothymol Blue. Learners are encouraged to consider how the results of this experiment would change if they added an aquatic plant to the beaker and also design a method for demonstrating how plants give off carbon dioxide.

Bunnell, Dave

2008-01-01

28

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

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

30

The Carbon Cycle: Carbon Tracker  

NSDL National Science Digital Library

In this activity, learners play NOAA's Carbon Tracker game and discover ways to keep track of carbon dioxide and other greenhouse gases in the world. This game will help learners better understand how the uptake and release of greenhouse gases affect oceans, the atmosphere, ecosystems, the land, plants, and animals on Earth. This game can be played by groups of learners or an individual learner. The resource contains a CarbonTracker Poster that identifies key words and important information related to greenhouse gases and climate change.

Beverly L. Meier

2011-08-20

31

Carbon sequestration.  

PubMed

Developing technologies to reduce the rate of increase of atmospheric concentration of carbon dioxide (CO2) from annual emissions of 8.6PgCyr-1 from energy, process industry, land-use conversion and soil cultivation is an important issue of the twenty-first century. Of the three options of reducing the global energy use, developing low or no-carbon fuel and sequestering emissions, this manuscript describes processes for carbon (CO2) sequestration and discusses abiotic and biotic technologies. Carbon sequestration implies transfer of atmospheric CO2 into other long-lived global pools including oceanic, pedologic, biotic and geological strata to reduce the net rate of increase in atmospheric CO2. Engineering techniques of CO2 injection in deep ocean, geological strata, old coal mines and oil wells, and saline aquifers along with mineral carbonation of CO2 constitute abiotic techniques. These techniques have a large potential of thousands of Pg, are expensive, have leakage risks and may be available for routine use by 2025 and beyond. In comparison, biotic techniques are natural and cost-effective processes, have numerous ancillary benefits, are immediately applicable but have finite sink capacity. Biotic and abiotic C sequestration options have specific nitches, are complementary, and have potential to mitigate the climate change risks. PMID:17761468

Lal, Rattan

2008-02-27

32

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

33

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.

NASA: Challenger Center

34

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

35

Carbon microtubes  

DOEpatents

A carbon microtube comprising a hollow, substantially tubular structure having a porous wall, wherein the microtube has a diameter of from about 10 .mu.m to about 150 .mu.m, and a density of less than 20 mg/cm.sup.3. Also described is a carbon microtube, having a diameter of at least 10 .mu.m and comprising a hollow, substantially tubular structure having a porous wall, wherein the porous wall comprises a plurality of voids, said voids substantially parallel to the length of the microtube, and defined by an inner surface, an outer surface, and a shared surface separating two adjacent voids.

Peng, Huisheng (Shanghai, CN); Zhu, Yuntian Theodore (Cary, NC); Peterson, Dean E. (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM)

2011-06-14

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

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.

NBC Learn

2010-10-07

38

Morphological Changes of Human Dentin after Erbium-Doped Yttrium Aluminum Garnet (Er:YAG) and Carbon Dioxide (CO2) Laser Irradiation and Acid-etch Technique: An Scanning Electron Microscopic (SEM) Evaluation  

PubMed Central

Introduction: The aim of this study was to investigate the morphological changes of human dentin after Erbium-Doped Yttrium Aluminum Garnet (Er:YAG), Carbon Dioxide(CO2) laser-irradiation and acid-etching by means of scanning electron microscopic (SEM) Methods: 9 extracted human third molars were used in this study. The teeth were divided in three groups: first group, CO2 laser with power of 1.5 w and frequency of 80 Hz; second group, Er:YAG laser with output power of 1.5 W frequency of 10 Hz, very short pulse with water and air spray was applied; and third group, samples were prepared by acid-etching 37% for 15 sec and rinsed with air-water spray for 20 sec. Then, the samples were prepared for SEM examination. Results: Melting and cracks can be observed in CO2 laser but in Er:YAG laser cleanedablated surfaces and exposed dentinal tubules, without smear layer was seen. Conclusion: It can be concluded that Er:YAG laser can be an alternative technique for surface treatment and can be considered as safe as the conventional methods. But CO2 laser has some thermal side effects which make this device unsuitable for this purpose. PMID:25606306

Shahabi, Sima; Chiniforush, Nasim; Juybanpoor, Nasrin

2013-01-01

39

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

40

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.

41

Carbonic Anhydrase  

Microsoft Academic Search

It was shown by Henriques1 that the rate at which carbon dioxide is evolved in the reaction H2COS CO2 + H2O is greatly accelerated by the presence of laked blood, mere traces of which are sufficient to catalyse this reaction4. That this accelera-tion is not due to hæmoglobin was clearly demon-strated by Meldrum and Roughton3,4 who have separated from the

D. Keilin; T. Mann

1939-01-01

42

CARBON-CLIMATE INTERACTIONS CARBON-CLIMATEINTER-  

E-print Network

CARBON-CLIMATE INTERACTIONS NATO ASI #12;#12;CARBON-CLIMATEINTER- ACTIONS NATO ASI Edited by M the strength of the biological carbon pump and ultimately the impact of ocean biology on atmospheric CO2. Among of the marine nitrogen cycle and its coupling to the marine oxygen, phosphorus, and carbon cycles. The marine

Gruber, Nicolas

43

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

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Carbon disulfide (carbon bisulfide). 151.50-41...Requirements § 151.50-41 Carbon disulfide (carbon bisulfide). (a) All openings...arrest its flame propagation, carbon disulfide (carbon bisulfide ) requires...

2010-10-01

44

Public Review Draft: A Method for Assessing Carbon Stocks, Carbon  

E-print Network

Public Review Draft: A Method for Assessing Carbon Stocks, Carbon Sequestration, and Greenhouse, and Zhu, Zhiliang, 2010, Public review draft; A method for assessing carbon stocks, carbon sequestration

45

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.

2012-10-18

46

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.

47

Trading forest carbon  

EPA Science Inventory

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

48

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

49

Carbon Nanotube Quantum Dot  

E-print Network

Carbon Nanotube Quantum Dot with Superconducting Electrodes Bachelor of Science Thesis Faculty of march 2010. The study of the electrical properties of carbon nanotubes falls under meso- scopic physics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3 Theory 8 3.1 Carbon Nanotubes . . . . . . . . . . . . . . . . . . . . . . . . 8 3

Nygård, Jesper

50

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

51

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

52

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

53

Calcium carbonate overdose  

MedlinePLUS

Calcium carbonate is an ingredient that is commonly found in antacids (for heartburn) and some dietary supplements. Calcium carbonate overdose occurs when someone accidentally or intentionally takes ...

54

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

55

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

56

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

57

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)

1995-01-01

58

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

59

Composite carbon foam electrode  

DOEpatents

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

Mayer, Steven T. (San Leandro, CA); Pekala, Richard W. (Pleasant Hill, CA); Kaschmitter, James L. (Pleasanton, CA)

1997-01-01

60

Composite carbon foam electrode  

DOEpatents

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

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

1997-05-06

61

Variable Carbon Isotopes in ALH84001 Carbonates  

NASA Astrophysics Data System (ADS)

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 new carbon isotopic measurements performed on the Cameca 6f ion microprobe at Arizona State University. Isotopic measurements were made at high mass resolution with a spot size of 10 microns. The measured carbon isotopic values range from 29.2‰ to 64.5‰ (PDB) with an average uncertainty of +/-1.6‰ (1? ). These data agree very well with previous acid dissolution and stepped combustion experiments which range from a ?13C of +32‰ to +41‰ . As observed with the oxygen isotopic data, the carbon isotopic composition is correlated with the chemical composition of the carbonates. This allows us to establish that the earliest (Ca-rich) carbonates had the lightest carbon isotopic composition while the latest forming (Mg-rich) carbonates had the heaviest carbon isotopic composition. The large range of carbon isotopic compositions measured in this study cannot be explained by previously proposed models. Temperature change or a Rayleigh distillation process caused by progressive carbonate precipitation are insufficient to create the observed carbon isotopic compositions. Furthermore, processes such as evaporation or photosynthesis will not produce large carbon isotopic variations due to rapid isotopic equilibration with the atmosphere. We propose two possible models for the formation of the ALH84001 carbonates consistent with the isotopic data collected thus far. Carbonates could have formed from an evolving system where the carbon and oxygen isotopic composition of the carbonates reflects a mixing between magmatic hydrothermal fluids and fluids in equilibrium with an isotopically heavy atmosphere. Alternatively, carbon enrichment could have occurred as a portion of the carbon dioxide is reduced through abiotic Fischer-Tropsch synthesis or biologically mediated methanogenesis. In this scenario, cooling of the system over time would be necessary to create observed oxygen isotopic values.

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

2002-12-01

62

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

63

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

64

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.

65

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.

Colorado Plateau Climate Science and Solutions Partnership

66

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

67

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

68

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

69

Mesoporous carbon materials  

DOEpatents

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

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

2014-09-09

70

Growth of carbon nanofibers on activated carbon fiber fabrics  

Microsoft Academic Search

Activated carbon fiber fabrics, an excellent adsorbent, were used as catalyst supports to grow carbon nanofibers. Because of the microporous structure of the activated carbon fibers, the catalysts could be distributed uniformly on the carbon surface. Based on this concept, the carbon nanofibers can be grown directly on the activated carbon fiber fabrics. We demonstrate that carbon nanofibers with a

Shinn-Shyong Tzeng; Kai-Hsuan Hung; Tse-Hao Ko

2006-01-01

71

Carbon fibers modified with carbon nanotubes  

Microsoft Academic Search

Carbon nanotubes were used to modify a polyacrylonitrile (PAN) polymer solution before the manufacture of the carbon fiber\\u000a precursor. The modified PAN fibers were spun from a dimethylformamide solution containing a small amount of single-walled\\u000a carbon nanotubes. The fibers were characterized by thermogravimetry and optical and scanning electron microscopy. Structure,\\u000a morphology, and selected properties of the composite polymeric fibers and

Aneta Fraczek-Szczypta; Maciej Bogun; Stanislaw Blazewicz

2009-01-01

72

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

73

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

74

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

75

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

76

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.

2011-04-29

77

Synthesis of carbon nanotubes.  

PubMed

Carbon nanotubes play a fundamental role in the rapidly developing field of nanoscience and nanotechnology because of their unique properties and high potential for applications. In this article, the different synthesis methods of carbon nanotubes (both multi-walled and single-walled) are reviewed. From the industrial point of view, the chemical vapor deposition method has shown advantages over laser vaporization and electric arc discharge methods. This article also presents recent work in the controlled synthesis of carbon nanotubes with ordered architectures. Special carbon nanotube configurations, such as nanocoils, nanohorns, bamboo-shaped and carbon cylinder made up from carbon nanotubes are also discussed. PMID:16245519

Awasthi, Kalpana; Srivastava, Anchal; Srivastava, O N

2005-10-01

78

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

79

Trading forest carbon - OSU  

EPA Science Inventory

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

80

Carbon Monoxide (CO)  

MedlinePLUS

... Basic Information on Pollutants and Sources of Indoor Air Pollution Asbestos Biological Pollutants Carbon Monoxide (CO) Formaldehyde/Pressed Wood Products Lead (Pb) Nitrogen Dioxide (NO 2 ... Read "Care for Your Air: A Guide to Indoor Air Quality" Carbon monoxide ...

81

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.

82

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

83

Carbon Mineralization and Labile Organic Carbon Pools in the Sandy  

E-print Network

Carbon Mineralization and Labile Organic Carbon Pools in the Sandy Soils of a North Florida of California, Riverside, Riverside, California 92521, USA ABSTRACT The large pool of actively cycling carbon (C words: hot-water-extractable carbon; acid- hydrolyzable carbon; carbon mineralization; coastal plain

Grunwald, Sabine

84

Carbon/Carbon Pistons for Internal Combustion Engines  

NASA Technical Reports Server (NTRS)

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

Taylor, A. H.

1986-01-01

85

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

86

Carbon Dioxide & Global Warming  

E-print Network

Carbon Dioxide & Global Warming University of MiaMi rosenstiel sChool of Marine anD atMospheriC s ­ it allows sunlight in, but gases in the atmosphere, especially carbon dioxide (CO2 ), allow less to breathe. Respi- ration by these organisms returns this carbon to the atmosphere as CO2 . Unfortunately

Miami, University of

87

CARBON DIOXIDE EMISSION REDUCTION  

E-print Network

CARBON DIOXIDE EMISSION REDUCTION TECHNOLOGIES AND MEASURES IN US INDUSTRIAL SECTOR FINAL REPORT TO KOREA ENVIRONMENT INSTITUTE FEBRUARY 2007 #12;B #12;C CARBON DIOXIDE EMISSION REDUCTION TECHNOLOGIES.5 Primary Energy Use and Carbon Dioxide Emissions for Selected US Chemical Subsectors in 1994

Delaware, University of

88

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

89

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.

90

Intro to Carbon Sequestration  

SciTech Connect

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.

2008-03-06

91

Carbon Nanotube Image Gallery  

NSDL National Science Digital Library

The mission of NanoLab, Inc. is to utilize nanoscale science and engineering to create high value products from carbon nanotubes, aligned carbon nanotube arrays, and other nanomaterials. This website provides an image gallery of: carbon nanotubes, nanoparticles, nanowire, as well as nanotube fillings, coatings, and arrays.

92

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.

93

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

94

The Taste of Carbonation  

PubMed Central

Summary Carbonated beverages are commonly available and immensely popular, but little is known about the cellular and molecular mechanisms underlying the perception of carbonation in the mouth. In mammals, carbonation elicits both somatosensory and chemosensory responses, including activation of taste neurons. We have now identified the cellular and molecular substrates for the taste of carbonation. By targeted genetic ablation and the silencing of synapses in defined populations of taste receptor cells, we demonstrate that the sour-sensing cells act as the taste sensors for carbonation, and show that carbonic anhydrase 4, a glycosyl-phosphatidyl inositol (GPI)-anchored enzyme, functions as the principal CO2 taste sensor. These studies reveal the basis of the taste of carbonation, and the contribution of taste cells in the orosensory response to CO2. PMID:19833970

Chandrashekar, Jayaram; Yarmolinsky, David; von Buchholtz, Lars; Oka, Yuki; Sly, William; Ryba, Nicholas J. P.; Zuker, Charles S.

2013-01-01

95

The Carbon Cycle  

NASA Astrophysics Data System (ADS)

Reducing carbon dioxide (CO2) emissions is imperative to stabilizing our future climate. Our ability to reduce these emissions combined with an understanding of how much fossil-fuel-derived CO2 the oceans and plants can absorb is central to mitigating climate change. In The Carbon Cycle, leading scientists examine how atmospheric carbon dioxide concentrations have changed in the past and how this may affect the concentrations in the future. They look at the carbon budget and the "missing sink" for carbon dioxide. They offer approaches to modeling the carbon cycle, providing mathematical tools for predicting future levels of carbon dioxide. This comprehensive text incorporates findings from the recent IPCC reports. New insights, and a convergence of ideas and views across several disciplines make this book an important contribution to the global change literature.

Wigley, T. M. L.; Schimel, D. S.

2005-08-01

96

Carbon in detonations  

SciTech Connect

We review three principal results from a five year study of carbon and its properties in detonations and discuss the implications of these results to the behavior of explosives. We first present a new determination of the carbon melt line from release wave velocity measurements in the shocked state. We then outline a colloidal theory of carbon clustering which from diffusion limited coagulation predicts a slow energy release rate for the carbon chemistry. Finally, we show the results from the examination of recovered soot. Here we see support for the colloid theory and find the diamond phase of carbon. The main theme of this paper is that the carbon in detonation products is in the form of a colloidal suspension of carbon clusters which grow through diffusion limited collisions. Even the final state is not bulk graphite or diamond, but is a collection of small, less than 100 /angstrom/A, diamond and graphitic clusters. 23 refs., 4 figs.

Johnson, J.D.

1989-01-01

97

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

98

Carbon isotopes in mollusk shell carbonates  

NASA Astrophysics Data System (ADS)

Mollusk shells contain many isotopic clues about calcification physiology and environmental conditions at the time of shell formation. In this review, we use both published and unpublished data to discuss carbon isotopes in both bivalve and gastropod shell carbonates. Land snails construct their shells mainly from respired CO2, and shell ?13C reflects the local mix of C3 and C4 plants consumed. Shell ?13C is typically >10‰ heavier than diet, probably because respiratory gas exchange discards CO2, and retains the isotopically heavier HCO3 -. Respired CO2 contributes less to the shells of aquatic mollusks, because CO2/O2 ratios are usually higher in water than in air, leading to more replacement of respired CO2 by environmental CO2. Fluid exchange with the environment also brings additional dissolved inorganic carbon (DIC) into the calcification site. Shell ?13C is typically a few ‰ lower than ambient DIC, and often decreases with age. Shell ?13C retains clues about processes such as ecosystem metabolism and estuarine mixing. Ca2+ ATPase-based models of calcification physiology developed for corals and algae likely apply to mollusks, too, but lower pH and carbonic anhydrase at the calcification site probably suppress kinetic isotope effects. Carbon isotopes in biogenic carbonates are clearly complex, but cautious interpretation can provide a wealth of information, especially after vital effects are better understood.

McConnaughey, Ted A.; Gillikin, David Paul

2008-10-01

99

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

100

Carbon dioxide sensor  

DOEpatents

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

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

2011-11-15

101

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 (Knoxville, TN); Wang, Xiqing (Oak Ridge, TN)

2012-02-14

102

Plumbing carbon nanotubes  

NASA Astrophysics Data System (ADS)

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

Jin, Chuanhong; Suenaga, Kazu; Iijima, Sumio

2008-01-01

103

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

104

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

105

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

106

Carbon Calculator Activity  

NSDL National Science Digital Library

In this learning activity, students use a web-based carbon calculator to determine their carbon footprint on the basis of their personal and household habits and choices. Students identify which personal activities and household choices produce the most CO2 emissions, compare their carbon footprint to the U.S. and global averages, and identify lifestyle changes they can make to reduce their footprint.

Environmental Literacy and Inquiry Working Group at Lehigh University

107

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

108

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, Richard C. (East Hartford, CT)

1986-09-02

109

Composites of Carbon Nanotubes.  

E-print Network

??The purpose of this research was to study various methods of incorporation of single-walled carbon nanotubes (SWNT) with polymers for producing electrically conductive polystyrene composites.… (more)

Tchoul, Maxim N.

2008-01-01

110

Temperature VS Carbon Dioxide  

NSDL National Science Digital Library

In this activity, students examine the relationship between carbon dioxide levels and global temperature change by studying a graph of these two variables. They will discover that by using data from ice cores, scientists can determine temperature and carbon dioxide levels in the air as far back as a hundred thousand years in the past. The students try to predict which variable is the independent one and then make a graph of temperature change and carbon dioxide levels. After making their graph, students describe the relationship between temperature and carbon dioxide levels in the atmosphere to determine if their predictions were correct.

111

Carbon dioxide sequestration by mineral carbonation  

SciTech Connect

Concerns about global warming caused by the increasing concentration of carbon dioxide and other greenhouse gases in the earth’s atmosphere have resulted in the need for research to reduce or eliminate emissions of these gases. Carbonation of magnesium and calcium silicate minerals is one possible method to achieve this reduction. It is possible to carry out these reactions either in situ (storage underground and subsequent reaction with the host rock to trap CO2 as carbonate minerals) or ex situ (above ground in a more traditional chemical processing plant). Research at the Department of Energy’s Albany Research Center has explored both of these routes. This paper will explore parameters that affect the direct carbonation of magnesium silicate minerals serpentine (Mg3Si2O5(OH)4) and olivine (Mg2SiO4) to produce magnesite (MgCO3), as well as the calcium silicate mineral, wollastonite (CaSiO3), to form calcite (CaCO3). The Columbia River Basalt Group is a multi-layered basaltic lava plateau that has favorable mineralogy and structure for storage of CO2. Up to 25% combined concentration of Ca, Fe2+, and Mg cations could react to form carbonates and thus sequester large quantities of CO2. Core samples from the Columbia River Basalt Group were reacted in an autoclave for up to 2000 hours at temperatures and pressures to simulate in situ conditions. Changes in core porosity, secondary minerals, and solution chemistry were measured.

Gerdemann, Stephen J.; Dahlin David C.; O'Connor William K.; Penner Larry R.

2003-11-01

112

Carbon/Carbon Panels Cooled By Heat Pipes  

NASA Technical Reports Server (NTRS)

Durable and reusable high-temperature carbon/carbon heat-pipe structure operates at temperatures above 3,000 degree F (1,649 degree C) in vacuum or inert environment and up to 2,800 degree F (1,537 degree C) in oxidizing environment. New concept combines high-temperature heat-pipe and carbon/carbon technologies to extend both thermal structural capabilities of refractory-metal heat pipes and maximum heat-flux capability of carbon/carbon structures. Uses refractory-metal heat pipes embedded within carbon/carbon structure. Walls of heat pipes thin and contain working fluid (lithium or sodium) of heat pipe. Carbon/carbon acts as primary load-carrying part of structure. Heat pipes help to eliminate local hotspots and associated thermal gradients and stresses and to reduce peak surface temperatures of carbon/carbon to levels within capability of oxidation-resisting system.

Camarda, Charles J.; Ransone, Philip O.

1989-01-01

113

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

114

Microbially mediated mineral carbonation  

NASA Astrophysics Data System (ADS)

Mineral carbonation involves silicate dissolution and carbonate precipitation, which are both natural processes that microorganisms are able to mediate in near surface environments (Ferris et al., 1994; Eq. 1). (Ca,Mg)SiO3 + 2H2CO3 + H2O ? (Ca,Mg)CO3 + H2O + H4SiO4 + O2 (1) Cyanobacteria are photoautotrophs with cell surface characteristics and metabolic processes involving inorganic carbon that can induce carbonate precipitation. This occurs partly by concentrating cations within their net-negative cell envelope and through the alkalinization of their microenvironment (Thompson & Ferris, 1990). Regions with mafic and ultramafic bedrock, such as near Atlin, British Columbia, Canada, represent the best potential sources of feedstocks for mineral carbonation. The hydromagnesite playas near Atlin are a natural biogeochemical model for the carbonation of magnesium silicate minerals (Power et al., 2009). Field-based studies at Atlin and corroborating laboratory experiments demonstrate the ability of a microbial consortium dominated by filamentous cyanobacteria to induce the precipitation of carbonate minerals. Phototrophic microbes, such as cyanobacteria, have been proposed as a means for producing biodiesel and other value added products because of their efficiency as solar collectors and low requirement for valuable, cultivable land in comparison to crops (Dismukes et al., 2008). Carbonate precipitation and biomass production could be facilitated using specifically designed ponds to collect waters rich in dissolved cations (e.g., Mg2+ and Ca2+), which would allow for evapoconcentration and provide an appropriate environment for growth of cyanobacteria. Microbially mediated carbonate precipitation does not require large quantities of energy or chemicals needed for industrial systems that have been proposed for rapid carbon capture and storage via mineral carbonation (e.g., Lackner et al., 1995). Therefore, this biogeochemical approach may represent a readily implemented and economically efficient alternative to other technologies currently under development for mineral sequestration. Dismukes GC, Carrieri D, Bennette N, Ananyev GM, Posewitz MC (2008) Aquatic phototrophs: efficient alternatives to land-based crops for biofuels. Current Opinion in Biotechnology, 19, 235-240. Ferris FG, Wiese RG, Fyfe WS (1994) Precipitation of carbonate minerals by microorganisms: Implications of silicate weathering and the global carbon dioxide budget. Geomicrobiology Journal, 12, 1-13. Lackner KS, Wendt CH, Butt DP, Joyce EL, Jr., Sharp DH (1995) Carbon dioxide disposal in carbonate minerals. Energy, 20, 1153-1170. Power IM, Wilson SA, Thom JM, Dipple GM, Gabites JE, Southam G (2009) The hydromagnesite playas of Atlin, British Columbia, Canada: A biogeochemical model for CO2 sequestration. Chemical Geology, 206, 302-316. Thompson JB, Ferris FG (1990) Cyanobacterial precipitation of gypsum, calcite, and magnesite from natural alkaline lake water. Geology, 18, 995-998.

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

2010-12-01

115

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

116

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

117

99 soil carbon .52 Carbon isotope ratios in belowground carbon cycle processes  

E-print Network

99 soil carbon .52 Carbon isotope ratios in belowground carbon cycle processes James R. Ehleringer 801-581-4665 #12;Abstract Analyses of carbon isotope ratios ( 13 C) in soil organic matter (SOM) and soil respired CO 2 provide insights into dynamics of the carbon cycle. 13 C analyses do not provide

Ehleringer, Jim

118

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

119

Production of Carbon Dioxide  

NSDL National Science Digital Library

In this chemistry activity, learners use common chemicals to produce carbon dioxide and observe its properties. This resource includes brief questions for learners to answer after the experiment. Use this activity to introduce learners to carbon dioxide and its use as a fire extinguisher. Note: this activity involves an open flame.

House, The S.

2014-01-28

120

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

121

Carbon Dioxide Emission Estimates  

NSDL National Science Digital Library

The Carbon Dioxide Information Analysis Center of the Oak Ridge National Laboratory provides this new data on carbon dioxide emissions from fossil fuel burning, hydraulic cement production, and gas flaring in 1995. Data for one degree grid cells can be downloaded from the site in addition to code for analysis of the data.

122

Modeling Carbon Exchange  

NASA Technical Reports Server (NTRS)

Model results will be reviewed to assess different methods for bounding the terrestrial role in the global carbon cycle. It is proposed that a series of climate model runs could be scoped that would tighten the limits on the "missing sink" of terrestrial carbon and could also direct future satellite image analyses to search for its geographical location and understand its seasonal dynamics.

Sellers, Piers

2012-01-01

123

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.

2012-12-26

124

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

125

Sustainable carbon materials.  

PubMed

Carbon-based structures are the most versatile materials used in the modern field of renewable energy (i.e., in both generation and storage) and environmental science (e.g., purification/remediation). However, there is a need and indeed a desire to develop increasingly more sustainable variants of classical carbon materials (e.g., activated carbons, carbon nanotubes, carbon aerogels, etc.), particularly when the whole life cycle is considered (i.e., from precursor "cradle" to "green" manufacturing and the product end-of-life "grave"). In this regard, and perhaps mimicking in some respects the natural carbon cycles/production, utilization of natural, abundant and more renewable precursors, coupled with simpler, lower energy synthetic processes which can contribute in part to the reduction in greenhouse gas emissions or the use of toxic elements, can be considered as crucial parameters in the development of sustainable materials manufacturing. Therefore, the synthesis and application of sustainable carbon materials are receiving increasing levels of interest, particularly as application benefits in the context of future energy/chemical industry are becoming recognized. This review will introduce to the reader the most recent and important progress regarding the production of sustainable carbon materials, whilst also highlighting their application in important environmental and energy related fields. PMID:25301517

Titirici, Maria-Magdalena; White, Robin J; Brun, Nicolas; Budarin, Vitaliy L; Su, Dang Sheng; Del Monte, Francisco; Clark, James H; MacLachlan, Mark J

2015-01-01

126

Carbon Energy Flows Belowground  

Technology Transfer Automated Retrieval System (TEKTRAN)

Plants use photosynthesis to convert carbon dioxide in the atmosphere and energy from sunlight into energy-containing, carbon-based foodstuffs (i.e. carbohydrates such as sugars and starches) that provide the building blocks for all life on Earth. Without photosynthesis, sunlight would not be a goo...

127

Carbon Dioxide and Climate.  

ERIC Educational Resources Information Center

The amount of carbon dioxide in the atmosphere is increasing at a rate that could cause significant warming of the Earth's climate in the not too distant future. Oceanographers are studying the role of the ocean as a source of carbon dioxide and as a sink for the gas. (Author/BB)

Brewer, Peter G.

1978-01-01

128

China's carbon conundrum  

NASA Astrophysics Data System (ADS)

China's carbon dioxide emissions are rising fast. Yet, per capita, gross domestic product and energy use are only a fraction of their United States equivalents. With a growing urban middle class, the trend will continue, but there is progress on the path to a low-carbon economy.

Qi, Ye; Wu, Tong; He, Jiankun; King, David A.

2013-07-01

129

Ingredients for Life: Carbon  

NSDL National Science Digital Library

Carbon is the basis of all organic molecules. It is also one of the most abundant elements in the universe. This video segment illustrates the special characteristics of carbon that make it an essential ingredient for life. The segment is one minute thirty-eight seconds in length. A background essay and list of discussion questions are also provided.

2011-07-22

130

Carbon Arc Image Furnaces  

Microsoft Academic Search

Various optical systems are discussed with reference to their use with carbon arc image furnaces. A new optical system which employs two elliptical mirrors is described and shown to have numerous practical advantages. Using modifications of motion picture projection lamps, measurements have been made of carbon arc image furnaces ranging up to more than 26-kw power input, producing approximately 3000-watts

M. R. Null; W. W. Lozier

1958-01-01

131

Nanotube composite carbon fibers  

Microsoft Academic Search

Single walled carbon nanotubes (SWNTs) were dispersed in isotropic petroleum pitch matrices to form nanotube composite carbon fibers with enhanced mechanical and electrical properties. We find that the tensile strength, modulus, and electrical conductivity of a pitch composite fiber with 5 wt % loading of purified SWNTs are enhanced by ~90%, ~150%, and 340% respectively, as compared to the corresponding

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

1999-01-01

132

Simplified Carbonate Sequence Stratigraphy  

NSDL National Science Digital Library

Students interpret shallow to deep marine carbonate environments developed across a 150-km wide carbonate platform, identify a single depositional sequence (and internal systems tracts), correlate facies, then reconstruct the platform geometry at specific time intervals during sequence development. This exercise is based on a real-world example and can be modified based on available samples.

maya elrick

133

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

134

Isolation of Carbon Nanostructures  

SciTech Connect

Carbon nanostructures such a single wall carbon nanotubes (SWCNT), double wall carbon nanotubes (DWCNT) and fullerene peapods (e.g. C70 at SWCNT) usually occur in the form of bundles. Here, we present application of a novel simple and versatile method for deposition of small isolated nanoribbons of carbon nanotubes on annealed gold surface. The nanoribbons were characterized by Raman spectroscopy and exhibit characteristic features of individual carbon nanostructures. The resonance condition allowed the observation of a distinct spectrum of one inner tube in the nanoribbon from DWCNT. The signal of inner tubes of isolated DWCNT nanoribbons was found to be up to 50 times stronger than the sum of signals of the corresponding tubes in buckypaper sample. This dramatic enhancement is assigned to SERS (surface enhanced resonant Raman scattering) effect.

Kalbac, Martin; Kavan, Ladislav [J. Heyrovsky Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejskova 3, CZ-182 23 Prague 8 (Czech Republic); Leibniz Institute of Solid State and Materials Research, Helmholtzstr. 20, D - 01069 Dresden (Germany); Pelouchova, Hana; Janda, Pavel; Zukalova, Marketa [J. Heyrovsky Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejskova 3, CZ-182 23 Prague 8 (Czech Republic); Dunsch, Lothar [Leibniz Institute of Solid State and Materials Research, Helmholtzstr. 20, D - 01069 Dresden (Germany)

2005-09-27

135

Atmospheric Carbon Dioxide and Carbon Reservoir Changes  

Microsoft Academic Search

The net release of CO2 from the biosphere to the atmosphere between 1850 and 1950 is estimated to amount to 1.2 × 109 tons of carbon per year. During this interval, changes in land use reduced the total terrestrial biomass by 7 percent. There has been a smaller reduction in biomass over the last few decades. In the middle 19th

Minze Stuiver

1978-01-01

136

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

137

Carbon monoxide poisoning  

PubMed Central

Carbon monoxide poisoning is a significant cause of illness and death. Its protean symptoms probably lead to a gross underestimation of its true incidence. Low levels of carbon monoxide aggravate chronic cardiopulmonary problems, and high levels are associated with cardiac arrhythmias and cerebral edema. Patients who survive acute poisoning are at risk of delayed neurologic sequelae. The measurement of carboxyhemoglobin levels does not reveal the tissue levels of carbon monoxide but is useful in determining therapy. Treatment includes the monitoring and management of cardiac arrhythmias and oxygenation. Hyperbaric oxygenation is beneficial, but there are currently no definite criteria for its use. PMID:4027805

Dolan, Michael C.

1985-01-01

138

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.

2012-10-05

139

Introduction to Carbon Nanotubes  

NASA Astrophysics Data System (ADS)

Carbon nanotubes are among the amazing objects that science sometimes creates by accident, without meaning to, but that will likely revolutionize the technological landscape of the century ahead. Our society stands to be significantly influenced by carbon nanotubes, shaped by nanotube applications in every aspect, just as silicon-based technology still shapes society today. The world already dreams of space-elevators tethered by the strongest of cables, hydrogen-powered vehicles, artificial muscles, and so on - feasts that would be made possible by the emerging carbon nanotube science.

Monthioux, Marc; Serp, Philippe; Flahaut, Emmanuel; Razafinimanana, Manitra; Laurent, Christophe; Peigney, Alain; Bacsa, Wolfgang; Broto, Jean-Marc

140

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

141

Carbon Distribution in PNe  

NASA Astrophysics Data System (ADS)

We present images showing the carbon distribution in PNe IRAS 18059-3211 (known as ``Gomez's Hamburger"). These images were originally taken with the WFPC-2 camera on the HST on 22 February 2002. Three different filters (F450W, F555W, and F675W) were used to record the images. One of the filters (F675W) is not sensitive to carbon in this object, so this filter is subtracted from the two other filters to create an image showing the spatial distribution of carbon. The Hubble Space Telescope is operated by NASA and ESA. We wish to acknowledge the support of NASA Contract NAS5-26555.

Garner, C. J.; Storrs, A. D.

2004-12-01

142

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

143

Carbon nanotube initiated formation of carbon nanoscrolls Zhao Zhang1  

E-print Network

Carbon nanotube initiated formation of carbon nanoscrolls Zhao Zhang1 and Teng Li1,2,a 1 Department; published online 26 August 2010 The unique topology and exceptional properties of carbon nanoscrolls CNSs graphene on a substrate, initiated by a carbon nanotube CNT . The rolling of graphene into a CNS

Li, Teng

144

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

145

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

146

46 CFR 151.50-40 - Additional requirements for carbon disulfide (carbon bisulfide) and ethyl ether.  

Code of Federal Regulations, 2010 CFR

... Additional requirements for carbon disulfide (carbon bisulfide) and ethyl ether... Additional requirements for carbon disulfide (carbon bisulfide) and ethyl ether...requirements of § 151.50-41 for carbon disulfide (carbon bisulfide ) and §...

2010-10-01

147

Porous carbons prepared by direct carbonization of MOFs for supercapacitors  

NASA Astrophysics Data System (ADS)

Three porous carbons were prepared by direct carbonization of HKUST-1, MOF-5 and Al-PCP without additional carbon precursors. The carbon samples obtained by carbonization at 1073 K were characterized by XRD, TEM and N2 physisorption techniques followed by testing for electrochemical performance. The BET surface areas of the three carbons were in the range of 50-1103 m2/g. As electrode materials for supercapacitor, the MOF-5 and Al-PCP derived carbons displayed the ideal capacitor behavior, whereas the HKUST-1 derived carbon showed poor capacitive behavior at various sweep rates and current densities. Among those carbon samples, Al-PCP derived carbons exhibited highest specific capacitance (232.8 F/g) in 30% KOH solution at the current density of 100 mA/g.

Yan, Xinlong; Li, Xuejin; Yan, Zifeng; Komarneni, Sridhar

2014-07-01

148

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

149

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

150

Carbon in the Oceans  

NSDL National Science Digital Library

In this assignment, students in small groups are asked to interpret and explain a figure depicting one aspect of marine carbon biogeochemistry. Then a representative of each group explains the figure to the class.

Townsend-Small, Amy

151

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

152

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.

WGBH Educational Foundation

2007-02-12

153

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

154

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

155

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

156

Global terrestrial carbon cycle  

SciTech Connect

There is great uncertainty with regard to the future role of the terrestrial biosphere in the global carbon cycle. The uncertainty arises from both an inadequate understanding of current pools and fluxes as well as the potential effects of rising atmospheric concentrations of CO2 on natural ecosystems. Despite these limitations, a number of studies have estimated current and future patterns of terrestrial carbon storage. Future estimates focus on the effects of a climate change associated with a doubled atmospheric concentration of CO2. Available models for examining the dynamics of terrestrial carbon storage and the potential role of forest management and landuse practices on carbon conservation and sequestration are discussed. (Copyright (c) 1993 Kluwer Academic Publishers.)

Smith, T.M.; Cramer, W.P.; Dixon, R.K.; Leemans, R.; Neilson, R.P.

1993-01-01

157

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

158

Carbon nanotubes: Fibrillar pharmacology  

NASA Astrophysics Data System (ADS)

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

Kostarelos, Kostas

2010-10-01

159

Molecular Structure of Carbonic acid  

NSDL National Science Digital Library

The hypothetical acid formed with carbon dioxide and water; it is only in the H2CO3 form when in solution. This acid is found in everyday products, the most prominent of which include carbonated beverages. The conversion of carbonic acid into water and carbon dioxide in sodas is the reason the beverage looses the bubbling.

2002-09-10

160

Carbon Nanoscience and Electronic Structure  

E-print Network

Carbon Nanoscience and Electronic Structure Louis Brus We explore the fundamental nature and dynamics of electrons in graphitic carbon materials. In semiconducting carbon nanotubes, near-infrared two. Electron-electron interactions are compared among CdSe nanocrystals, graphene, and carbon nanotubes

Lewis, Jennifer

161

Carbon Management working with the  

E-print Network

Carbon Management Plan (CMP) working with the Date: 2 March 2011 Version number: 1.0 Owner: Nigel Chancellor 4 Foreword from the Carbon Trust 5 Executive Summary 6 1. Introduction 9 2. Carbon Management Strategy 12 2.1 Context and drivers for Carbon Management 12 2.2 Strategic themes 14 2.3 Targets

Reading, University of

162

Computed tomography of replica carbon  

Microsoft Academic Search

LLNL programs utilize a low density, cellular carbon material. The manufacturing process for this material is described elsewhere. The material is called replica carbon'' because the carbon structure replicates that of a precursor material. For some applications, it is essential that replica carbon have a highly uniform density throughout a bar or finished component. We have for several years utilized

C. M. Logan; G. P. Roberson; D. L. Weirup; J. C. Davis; I. D. Proctor; D. W. Heikkinen; M. L. Roberts; H. E. Martz; D. J. Schneberk; S. G. Azevedo; A. E. Pontau; A. J. Antolak; D. H. Morse

1991-01-01

163

Elevated atmospheric carbon dioxide increases soil carbon  

Microsoft Academic Search

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

Richard J Norby; Michael R Miller; Roser Matamala; THOMAS W. BOUTTON; CHARLES W. RICE; CLENTON E. OWENSBY

2005-01-01

164

Carbon functionalities in amber.  

PubMed

High-resolution nuclear magnetic resonance spectra of the carbon nuclei in powdered amber, obtained by using the techniques of magic angle spinning and cross polarization, provide detailed information about the types of carbon functionalities. The entire spectrum of Baltic amber (succinite) is identical for several samples. Baltic amber shows minor differences from Sicilian amber and drastic differences from Burmese, Romanian, and Bohemian ambers. PMID:17739982

Lambert, J B; Frye, J S

1982-07-01

165

Forms of Carbon  

NSDL National Science Digital Library

In this activity, educators can demonstrate how the nanoscale arrangement of atoms dramatically impacts a materialâs macroscale behavior. Learners investigate the structure and properties of four different forms of carbon. During the program, learners interact with models of four different forms of carbon. Learners also observe the conductivity of graphite (using a simple circuit and an everyday pencil) and the hardness of diamond (using a diamond scribe to cut glass).

Network, Nanoscale I.

2014-06-10

166

Sedimentary Rocks: Carbonate Rocks  

NSDL National Science Digital Library

Sedimentary Rocks: Carbonate Rocks is a course handout meant to accompany the discussion of chemical and biochemical sedimentary rocks. Rock composition is broken into the main categories of limestone and dolostone. Depositional conditions are discussed, including the topics of coral reefs, plankton, and carbonate compensation depth (CCD). There are a few photographs, which display calcareous algae. Links are provided to the online Physical Geology resources at Georgia Perimeter College.

Gore, Pamela

167

Carbon Cycle Poster  

NSDL National Science Digital Library

In this activity, learners gain knowledge about how carbon moves through all four of the Earth’s 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.

California Academy of Sciences

2008-01-01

168

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

169

Carbon based prosthetic devices  

SciTech Connect

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

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

1998-12-31

170

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

171

The Contemporary Carbon Cycle  

NASA Astrophysics Data System (ADS)

The global carbon cycle refers to the exchanges of carbon within and between four major reservoirs: the atmosphere, the oceans, land, and fossil fuels. Carbon may be transferred from one reservoir to another in seconds (e.g., the fixation of atmospheric CO2 into sugar through photosynthesis) or over millennia (e.g., the accumulation of fossil carbon (coal, oil, gas) through deposition and diagenesis of organic matter). This chapter emphasizes the exchanges that are important over years to decades and includes those occurring over the scale of months to a few centuries. The focus will be on the years 1980-2000 but our considerations will broadly include the years ˜1850-2100. Chapter 8.09, deals with longer-term processes that involve rates of carbon exchange that are small on an annual timescale (weathering, vulcanism, sedimentation, and diagenesis).The carbon cycle is important for at least three reasons. First, carbon forms the structure of all life on the planet, making up ˜50% of the dry weight of living things. Second, the cycling of carbon approximates the flows of energy around the Earth, the metabolism of natural, human, and industrial systems. Plants transform radiant energy into chemical energy in the form of sugars, starches, and other forms of organic matter; this energy, whether in living organisms or dead organic matter, supports food chains in natural ecosystems as well as human ecosystems, not the least of which are industrial societies habituated (addicted?) to fossil forms of energy for heating, transportation, and generation of electricity. The increased use of fossil fuels has led to a third reason for interest in the carbon cycle. Carbon, in the form of carbon dioxide (CO2) and methane (CH4), forms two of the most important greenhouse gases. These gases contribute to a natural greenhouse effect that has kept the planet warm enough to evolve and support life (without the greenhouse effect the Earth's average temperature would be -33°C). Additions of greenhouse gases to the atmosphere from industrial activity, however, are increasing the concentrations of these gases, enhancing the greenhouse effect, and starting to warm the Earth.The rate and extent of the warming depend, in part, on the global carbon cycle. If the rate at which the oceans remove CO2 from the atmosphere were faster, e.g., concentrations of CO2 would have increased less over the last century. If the processes removing carbon from the atmosphere and storing it on land were to diminish, concentrations of CO2 would increase more rapidly than projected on the basis of recent history. The processes responsible for adding carbon to, and withdrawing it from, the atmosphere are not well enough understood to predict future levels of CO2 with great accuracy. These processes are a part of the global carbon cycle.Some of the processes that add carbon to the atmosphere or remove it, such as the combustion of fossil fuels and the establishment of tree plantations, are under direct human control. Others, such as the accumulation of carbon in the oceans or on land as a result of changes in global climate (i.e., feedbacks between the global carbon cycle and climate), are not under direct human control except through controlling rates of greenhouse gas emissions and, hence, climatic change. Because CO2 has been more important than all of the other greenhouse gases under human control, combined, and is expected to continue so in the future, understanding the global carbon cycle is a vital part of managing global climate.This chapter addresses, first, the reservoirs and natural flows of carbon on the earth. It then addresses the sources of carbon to the atmosphere from human uses of land and energy and the sinks of carbon on land and in the oceans that have kept the atmospheric accumulation of CO2 lower than it would otherwise have been. The chapter describes changes in the distribution of carbon among the atmosphere, oceans, and terrestrial ecosystems over the past 150 years as a result of human-induced emissions of carbon. The processes responsible fo

Houghton, R. A.

2003-12-01

172

Thermal oxidation of carbon nanomaterials  

NASA Astrophysics Data System (ADS)

The process of the thermal oxidation of various carbon nanomaterials (multiwalled carbon nanotubes, carbon black, nanoporous carbon and graphite) used in the catalytic layers of electrochemical energy converters (electrolyzers, fuel cells) has been studied. The thermal stability of these materials has been determined. Relationships between the structural characteristics of carbon nanomaterials and the parameters of their thermal oxidation in air have determined using the methods of differential thermal analysis and adsorption-structure analysis.

Glebova, N. V.; Nechitailov, A. A.; Kukushkina, Yu. A.; Sokolov, V. V.

2011-05-01

173

Carbon isotope effects in carbonate systems  

NASA Astrophysics Data System (ADS)

Global carbon cycle models require a complete understanding of the ? 13C variability of the Earth's C reservoirs as well as the C isotope effects in the transfer of the element among them. An assessment of ? 13C changes during CO 2 loss from degassing magmas requires knowledge of the melt-CO 2 carbon isotope fractionation. In order to examine the potential size of this effect for silicate melts of varying composition, 13C reduced partition functions were computed in the temperature range 275 to 4000 K for carbonates of varying bond strengths (Mg, Fe, Mn, Sr, Ba, Pb, Zn, Cd, Li, and Na) and the polymorphs of calcite. For a given cation and a given pressure the 13C content increases with the density of the carbonate structure. For a given structure the tendency to concentrate 13C increases with pressure. The effect of pressure (‰/10 kbar) on the size of the reduced partition function of aragonite varies with temperature; in the pressure range 1 to 10 5 bars the change is given by: ? 13C p average=-0.01796+0.06635? 10 3/T+0.006875? 10 6/T2 For calcite III the pressure effect is on average 1.4× larger than that for aragonite at all temperatures. The nature of the cation in a given structure type has a significant effect on the carbon isotope fractionation properties. The tendency to concentrate 13C declines in the series magnesite, aragonite, dolomite, strontianite, siderite, calcite, smithonite, witherite, rhodochrosite, otavite, cerrusite. For divalent cations a general expression for an estimation of the reduced partition function (?) from the reduced mass (? = [M Cation × M Carbonate]/[M Cation + M Carbonate]) is: 1000 ln?=(0.032367-0.072563? 10 3/T-0.01073? 10 6/T2)??-14.003+29.953? 10 3/T+9.4610? 10 6/T2 For Mg-calcite the 13C content varies with the Mg concentration. The fractionation between Mg-calcite (X = mole fraction of MgCO 3) and calcite is given by: 1000 ln(? MgCalite- Calcite)=[0.013702-0.10957× 10 3/T+1.35940× 10 6/T2-0.329124× 10 9/T3+0.0304160× 10 12/T4]× X1.5 The results of the computations were used together with previously published experimental vaporous CO 2-silicate melt fractionations to determine, at 1200°C, a relationship between melt-CO 213C fractionation and melt composition, expressed as molecular proportions of the cations Mg, Fe, Mn, Ca, Na, K and Si and Al: 1000 ln? Melt- CO2=5.14× Mg+ Fe+ Mn+ Ca+ Na+ K/Si+ Al+0.86 A conceptual model to understand this relationship was developed. The results of the computations approximate closely the experimentally determined vaporous CO 2-CaCO 3 fractionations at high temperatures. Empirically derived dolomite-calcite and calcite-graphite 13C isotope geothermometers agree with results of the present work.

Deines, Peter

2004-06-01

174

Carbon nanotube core graphitic shell hybrid fibers.  

PubMed

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

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

2013-12-23

175

WESTCARB Carbon Atlas  

DOE Data Explorer

The West Coast Regional Carbon Sequestration Partnership (known as WESTCARB) was established in Fall 2003. It is one of seven research partnerships co-funded by DOE to characterize regional carbon sequestration opportunities and conduct pilot-scale validation tests. The California Energy Commission manages WESTCARB and is a major co-funder. WESTCARB is characterizing the extent and capacity of geologic formations capable of storing CO2, known as sinks. Results are entered into a geographic information system (GIS) database, along with the location of major CO2-emitting point sources in each of the six WESTCARB states, enabling researchers and the public to gauge the proximity of candidate CO2 storage sites to emission sources and the feasibility of linking them via pipelines. Specifically, the WESTCARB GIS database (also known as the carbon atlas) stores layers of geologic information about potential underground storage sites, such as porosity and nearby fault-lines and aquifers. Researchers use these data, along with interpreted geophysical data and available oil and gas well logs to estimate the region's potential geologic storage capacity. The database also depicts existing pipeline routes and rights-of-way and lands that could be off-limits, which can aid the development of a regional carbon management strategy. The WESTCARB Carbon Atlas, which is accessible to the public, provides a resource for public discourse on practical solutions for regional CO2 management. A key WESTCARB partner, the Utah Automated Geographic Reference Center, has developed data serving procedures to enable the WESTCARB Carbon Atlas to be integrated with those from other regional partnerships, thereby supporting the U.S. Department of Energy's national carbon atlas, NATCARB

176

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

177

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

178

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 J; Alvizo, Oscar

2013-10-29

179

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

180

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

181

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

182

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

183

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.

184

Carbon-particle generator  

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, A.J.

1982-09-29

185

Carbon Fibers Conductivity Studies  

NASA Technical Reports Server (NTRS)

In an attempt to understand the process of electrical conduction in polyacrylonitrile (PAN)-based carbon fibers, calculations were carried out on cluster models of the fiber consisting of carbon, nitrogen, and hydrogen atoms using the modified intermediate neglect of differential overlap (MINDO) molecular orbital (MO) method. The models were developed based on the assumption that PAN carbon fibers obtained with heat treatment temperatures (HTT) below 1000 C retain nitrogen in a graphite-like lattice. For clusters modeling an edge nitrogen site, analysis of the occupied MO's indicated an electron distribution similar to that of graphite. A similar analysis for the somewhat less stable interior nitrogen site revealed a partially localized II electron distribution around the nitrogen atom. The differences in bonding trends and structural stability between edge and interior nitrogen clusters led to a two-step process proposed for nitrogen evolution with increasing HTT.

Yang, C. Y.; Butkus, A. M.

1980-01-01

186

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

187

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.

188

40 CFR 721.2084 - Carbon oxyfluoride (Carbonic difluoride).  

Code of Federal Regulations, 2011 CFR

(1) The chemical substance carbon oxyfluoride (CAS No. 353-50-4), also referred to as carbonic difluoride, is subject to reporting under this section for the significant new use described in paragraph (a)(2) of this...

2011-07-01

189

40 CFR 721.2084 - Carbon oxyfluoride (Carbonic difluoride).  

Code of Federal Regulations, 2012 CFR

(1) The chemical substance carbon oxyfluoride (CAS No. 353-50-4), also referred to as carbonic difluoride, is subject to reporting under this section for the significant new use described in paragraph (a)(2) of this...

2012-07-01

190

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

NASA Astrophysics Data System (ADS)

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 the composites increased with carbonization by two to three times that of pristine BP. These results indicate that discontinuity and intertube contact barriers of SWCNTs in the BP are partially overcome by the carbonization process of pitch. The temperature dependence of the Raman shift shows that mechanical strain is increased since carbonized pitch matrix surrounds the nanotubes.

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

2011-03-01

191

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

NASA Astrophysics Data System (ADS)

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 composites was evaluated after extended exposure to 4.5 MeV electrons. Electron exposure was conducted under argon utilizing a Mylar™ bag enclosure. Solar absorptance and infrared emittance was evaluated before and after exposure to identify optical properties degradation. Adhesion of the paints to the carbon-carbon and carbon-polyimide composite substrates was also of interest. Adhesion was evaluated on pristine and electron beam exposed coupons using a variation of the ASTM D-3359 tape test. Results of the optical properties evaluation and the adhesion tape tests are summarized.

Jaworske, Donald A.

2006-01-01

192

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

193

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.

194

Carbon Dioxide Exercise  

NSDL National Science Digital Library

In this activity, students work in groups, plotting carbon dioxide concentrations over time on overheads and estimating the rate of change over five years. Stacked together, the overheads for the whole class show an increase on carbon dioxide over five years and annual variation driven by photosynthesis. This exercise enables students to practice basic quantitative skills and understand how important sampling intervals can be when studying changes over time. A goal is to see how small sample size may give incomplete picture of data.

Richardson, Randy; Collection, Serc -.

195

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

196

Ultrahard carbon nanocomposite films  

SciTech Connect

Modest thermal annealing to 600 degree sign 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%. We report on the evolution of density and bonding topologies as a function of annealing temperature. Despite a decrease in density, film hardness actually increases {approx}15% due to the development of the nanocomposite structure. (c) 2000 American Institute of Physics.

Siegal, M. P. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States); Tallant, D. R. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States); Provencio, P. N. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States); Overmyer, D. L. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States); Simpson, R. L. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States); Martinez-Miranda, L. J. [Department of Materials and Nuclear Engineering, University of Maryland, College Park, Maryland 20742 (United States)] [Department of Materials and Nuclear Engineering, University of Maryland, College Park, Maryland 20742 (United States)

2000-05-22

197

Deep Recycling of Carbon  

NASA Astrophysics Data System (ADS)

While most of the subducted H2O is recycled at shallow and subarc depths, carbon is less readily mobilized and susceptive to complex redox processes involving CO2 in solids, fluids and melts, elemental carbon, Fe- and Si- carbides, and methane. Here I review the various ways of recycling carbon during subduction and present a spectrum of possible reaction products in the mantle. Metamorphic reactions liberate <20% of the subducted CO2 to the subarc region (Connolly 2005, EPSL). Larger amounts might be mobilized through (sediment) melting. Although the wet pelite solidus is only shifted by 30-50 oC (at 3 GPa) with carbonates, the latter remain stable with melts that are saturated in a H2O+CO2-fluid. Complete dissolution of carbonates requires temperatures above any predicted subduction geotherm. Carbonated sediments yield CO2-rich phonolites to 5 GPa but carbonatites at higher pressures. The silicate melts become increasingly potassic with pressure, while the alkali-rich carbonatites have their highest K/Na at 8 GPa, slightly decreasing to 13 GPa and become sodic with the disappearance of residual cpx at ~16 GPa. What may happen when carbonated pelite derived melts migrate into the mantle is illustrated in Central Italy: in this case, it can be experimentally demonstrated that hybridization of ultrapotassic phonolitic melts with ~2 wt% H2O and ~6 wt% CO2 in the mantle results in the primitive parents of the ultrapotassic kamafugite suites which have ~43 wt% SiO2. Hence, despite a crustal isotopic signature of C, O, and Sr in these rocks, the CO2 of the Italian magmatism does not stem from assimilation in the crust but from melts derived from subducted marine carbonates mixed with pelagic clays and then reacted in the mantle. The migration of CO2-bearing fluids and melts into the mantle may lead to a redox-shock. Where high liquid/mantle ratios prevail, carbonatites rest in their oxidized form and may only freeze in relatively cold lithospheric keels where they form metasomatic zones prone to generate kimberlites in the context of a much later remelting event. Where the redox-capacity of the oxidized crust-derived material is subequal to the reduced mantle, iron carbides are to be expected. The eutectic in the Fe-Ni-C system is at lower temperatures than the mantle adiabat, leading to the distinct possibility that such zones entrained in global mantle convection will contain ~1% of eutectic Fe-C-melt. When the amount of subduction derived CO2 is small compared to the redox capacity of a metal bearing reduced mantle, diamond will form, but diamond itself is not truly reducing at high pressures. The most extreme reducing case leads to moissanite (found together with diamond), which isotopic signature implies involvement of organically derived carbon. Moissanite (SiC) only forms at fO2 <6-8 log units below iron-wustite and coexists with mantle silicates that have an XMg of 0.995-0.998. Our calculations show that a fluid or melt with a bulk, which is slightly more reduced than the CO2-H2O-tieline in C-O-H, may evolve to ultra-reduced residual C-H-rich fluids through removal of CO2 (through carbonate precipitation) followed by removal of H2O (through hydrous silicate formation). As SiC may only be in grain scale equilibrium with the mantle and requires a protracted fluid-fractionation, we propose that SiC is generally a low temperature phase formed from originally already reducing fluids involving organic carbon and hence subduction.

Schmidt, M. W.

2012-12-01

198

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

199

SYNTHESIS OF CARBONATED FATTY METHYL ESTERS USING SUPERCRITICAL CARBON DIOXIDE  

Technology Transfer Automated Retrieval System (TEKTRAN)

The two step syntheses of the cyclic carbonates: carbonated methyl oleate (CMO) and carbonated methyl linoleate (CML) are reported. First, synthesis of the epoxide through well precedented chemical reaction of unsaturated fatty methyl esters with hydrogen peroxide and formic acid is performed. Nex...

200

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

201

Plasmachemical Synthesis of Carbon Suboxide  

E-print Network

of the theoretical thermodynamics and kinetics of carbon suboxide formation as well as experimental results. The theoretical analysis suggests that carbon suboxide may be an equilibrium product even at ambient conditions but favors lower temperatures; furthermore...

Geiger, Robert

2012-12-11

202

Carbon Taxation: The Way Forward  

E-print Network

Carbon Taxation: The Way Forward Friday, October 11 12:00 - 1:30 p.m. Ventana Room, ASU's Memorial discusses the benefits and feasibility of environmental fiscal reform and carbon taxation, using examples

Zhang, Junshan

203

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 ...

204

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

205

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

206

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

207

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

208

Carbon smackdown: smart windows  

SciTech Connect

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

2010-08-05

209

Measuring Caltech's Carbon Footprint  

Microsoft Academic Search

The project deals with collecting data on greenhouse gas emissions on the Caltech campus. The emissions are categorized in 3 scopes. Scope 1 includes direct emissions, scope 2 - indirect emissions from purchased water and electricity and scope 3 - other indirect emissions. The data is used as an input in a Carbon footprint calculator, giving as an output a

Stanislava Petkova

210

Carbon Dioxide Increases  

NSDL National Science Digital Library

In this problem set, learners will analyze the Keeling Curve showing carbon dioxide concentration in the atmosphere since 1985 to answer a series of questions. Answer key is provided. This is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

211

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

212

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.

Robert A. Rohde

213

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

214

Carbon-Fuelled Future  

SciTech Connect

Whether due to changes in policy or consumption of available fossil fuels, alternative sources of energy will be required, especially given the rising global energy demand. However, one of the main factors limiting the widespread utilization of renewable energy, such as wind, solar, wave or geothermal, is our ability to store energy. Storage of energy from carbon-neutral sources, such as electricity from solar or wind, can be accomplished through many routes. One approach is to store energy in the form of chemical bonds, as fuels. The conversion of low-energy compounds, such as water and carbon dioxide, to higher energy molecules, such as hydrogen or carbon-based fuels, enables the storage of carbon-neutral energy on a very large scale. The author¹s work in this area is supported by the US Department of Energy Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

Appel, Aaron M.

2014-09-12

215

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

216

Carbon nanotube electronics  

Microsoft Academic Search

We evaluate the potential of carbon nanotubes (CNTs) as the basis for a new nanoelectronic technology. After briefly reviewing the electronic structure and transport properties of CNTs, we discuss the fabrication of CNT field-effect transistors (CNTFETs) formed from individual single-walled nanotubes (SWCNTs), SWCNT bundles, or multiwalled (MW) CNTs. The performance characteristics of the CNTFETs are discussed and compared to those

PHAEDON AVOURIS; JOERG APPENZELLER; RICHARD MARTEL; SHALOM J. WIND

2003-01-01

217

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.

218

Comparing Carbon Calculators  

NSDL National Science Digital Library

Carbon calculators, no matter how well intended as tools to help measure energy footprints, tend to be black boxes and can produce wildly different results, depending on the calculations used to weigh various energy factors. By comparing different calculators, learners can analyze which ones are the most accurate and relevant, and which are the most transparent.

Mark McCaffrey

219

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

220

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

221

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...

222

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

223

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

224

Carbon: electrochemical and physicochemical properties  

SciTech Connect

This book provides a reference source for the application and study of carbon materials in electrochemistry. The first four chapters deal with the physical properties and chemical reactivity of carbon in its many forms. The remaining chapters focus on the role of carbon materials in electrode and electrochemistry applications. The book concludes with a complete listing of recently assigned patents pertaining to carbon-based electrodes and electrode substrates.

Kinoshita, K.

1988-01-01

225

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.

226

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

227

Low Carbon Development of Hainan  

NASA Astrophysics Data System (ADS)

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

Yi, Feng; Kun, Zhang

228

Turning green: assessing carbon footprints  

Microsoft Academic Search

ASSESSING and reducing carbon footprints – that is, how much carbon dioxide a building or business produces, directly and indirectly – is a hot topic, but what does it actually mean for practitioners? Here, Sarah Farley discusses how the University of Liverpool's Small Animal Teaching Hospital went about calculating its carbon footprint and identifying areas where emissions were high –

Sarah Farley

2009-01-01

229

Carbon: electrochemical and physicochemical properties  

Microsoft Academic Search

This book provides a reference source for the application and study of carbon materials in electrochemistry. The first four chapters deal with the physical properties and chemical reactivity of carbon in its many forms. The remaining chapters focus on the role of carbon materials in electrode and electrochemistry applications. The book concludes with a complete listing of recently assigned patents

K Kinoshita

1988-01-01

230

NANOFIBRILLAR CARBON FROM NATIVE CELLULOSE  

Microsoft Academic Search

Use of pyrolytic carbon from cellulose has been limited in practice to activated adsorbent carbon, but cellulose-derived carbon retaining the nanoscale microfibrillar morphology offers rich possibilities as an advanced material. Here we developed novel methods to prepare such materials by an improved drying of wet cellulose prior to pyrolysis. This procedure is an adaptation from electron microscopy techniques, i.e. rapid

O. Ishida; Y. Kim; S. Kuga; Y. Nishiyama

2002-01-01

231

Microfibrillar carbon from native cellulose  

Microsoft Academic Search

Use of pyrolytic carbon from cellulose has been limited in practice to activated adsorbent carbon, but cellulose-derived carbon retaining the nanoscale microfibrillar morphology offers rich possibilities as an advanced material. Here we developed novel methods to prepare such materials by an improved drying of wet cellulose prior to pyrolysis. This procedure is an adaptation from electron microscopy techniques, i.e. rapid

O. Ishida; D.-Y. Kim; S. Kuga; Y. Nishiyama

2004-01-01

232

Carbon Nanomaterials: The Ideal Interconnect  

E-print Network

Carbon 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-a`-vis optical and RF interconnects, and we illustrate why carbon nanomaterials constitute the ideal intercon

233

Carbon Nanotube Reinforced Polymer Nanocomposites  

E-print Network

Carbon Nanotube Reinforced Polymer Nanocomposites: Engineering the Interface at the Nano-Domain Wei Nanocomposites The Ideal "Straws" ­ Carbon Nanotubes 7.80.4208Steel 2.61501200MWCNT 1.341501054SWCNT Density (g on the surface of multi-walled carbon nanotubes are carried out using either a three-step chemical treatment

Southern California, University of

234

Carbon County Secondary Data Analysis  

E-print Network

Carbon County Secondary Data Analysis July 23, 2012 1 1 Community Health Data, MT Dept, Wheatland, Golden Valley, Musselshell, Sweet Grass, Stillwater, Yellowstone, Big Horn, and Carbon. CLRD* #12; Carbon County Secondary Data Analysis July 23, 2012 2 Socioeconomic Measures1

Maxwell, Bruce D.

235

5, 45994639, 2005 Global carbon  

E-print Network

ACPD 5, 4599­4639, 2005 Global carbon monoxide vertical distributions B. Barret et al. Title Page Discussions Global carbon monoxide vertical distributions from spaceborne high-resolution FTIR nadir Commons License. 4599 #12;ACPD 5, 4599­4639, 2005 Global carbon monoxide vertical distributions B. Barret

236

4, 99123, 2007 Amazon carbon  

E-print Network

BGD 4, 99­123, 2007 Amazon carbon balanc J. Lloyd et al. Title Page Abstract Introduction Discussions is the access reviewed discussion forum of Biogeosciences An airborne regional carbon balance January 2007 Correspondence to: J. Lloyd (j.lloyd@leeds.ac.uk) 99 #12;BGD 4, 99­123, 2007 Amazon carbon

Boyer, Edmond

237

7, 405428, 2007 SCIAMACHY carbon  

E-print Network

ACPD 7, 405­428, 2007 SCIAMACHY carbon monoxide M. Buchwitz et al. Title Page Abstract Introduction Discussions Three years of global carbon monoxide from SCIAMACHY: comparison with MOPITT and first results (michael.buchwitz@iup.physik.uni-bremen.de) 405 #12;ACPD 7, 405­428, 2007 SCIAMACHY carbon monoxide M

Paris-Sud XI, Université de

238

3, 409447, 2006 Modeling carbon  

E-print Network

BGD 3, 409­447, 2006 Modeling carbon dynamics in farmland of China F. Zhang et al. Title Page impacts of management alternatives on soil carbon storage of farmland in Northwest China F. Zhang1,3 , C Correspondence to: C. Li (changsheng.li@unh.edu) 409 #12;BGD 3, 409­447, 2006 Modeling carbon dynamics

Boyer, Edmond

239

5, 40834113, 2005 Black Carbon  

E-print Network

ACPD 5, 4083­4113, 2005 Black Carbon Specific Absorption in the Mexico City Metropolitan Area J. C and Physics Discussions Measurements of Black Carbon Specific Absorption in the Mexico City Metropolitan Area License. 4083 #12;ACPD 5, 4083­4113, 2005 Black Carbon Specific Absorption in the Mexico City Metropolitan

Paris-Sud XI, Université de

240

6, 363399, 2006 SCIAMACHY carbon  

E-print Network

ACPD 6, 363­399, 2006 SCIAMACHY carbon gas measurements: CO, CH4, and CO2 R. de Beek et al. Title and Physics Discussions Atmospheric carbon gases retrieved from SCIAMACHY by WFM-DOAS: improved global CO SCIAMACHY carbon gas measurements: CO, CH4, and CO2 R. de Beek et al. Title Page Abstract Introduction

Paris-Sud XI, Université de

241

5, 271296, 2008 Modeling carbon  

E-print Network

BGD 5, 271­296, 2008 Modeling carbon dynamics in Russian forests J. Kurbatova et al. Title Page carbon dynamics in two adjacent spruce forests with different soil conditions in Russia J. Kurbatova 1 Modeling carbon dynamics in Russian forests J. Kurbatova et al. Title Page Abstract Introduction

Paris-Sud XI, Université de

242

Carbon Nanotubes for Data Processing  

E-print Network

Carbon Nanotubes for Data Processing Joerg Appenzeller, T. J. Watson Research Center, IBM Research.2 Electronic Structure of Graphene 4 2.3 Electronic Structure of Carbon Nanotubes 4 2.4 Transport Properties 6 2.5 Contacts 9 3 Synthesis of Carbon Nanotubes 10 3.1 Synthetic Methods 10 3.2 Growth Mechanisms 12

Joselevich, Ernesto

243

Carbon Nanotube Linear Bearing Nanoswitches  

E-print Network

Carbon Nanotube Linear Bearing Nanoswitches V. V. Deshpande, H.-Y. Chiu, H. W. Ch. Postma, C. Miko-friction bearing capabilities of multiwalled carbon nanotubes (MWNTs) to realize nanoelectromechanical switches geometry remain important obstacles to the miniaturization of me- chanical systems. Carbon nanotubes

Bockrath, Marc

244

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

245

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

246

The Structures & Properties of Carbon  

ERIC Educational Resources Information Center

The four main forms of carbon--diamond, graphite, buckyballs, and carbon nanotubes (CNTs)--are an excellent vehicle for teaching fundamental principles of chemical bonding, material structure, and properties. Carbon atoms form a variety of structures that are intrinsically connected to the properties they exhibit. Educators can take advantage of…

Castellini, Olivia M.; Lisensky, George C.; Ehrlich, Jennifer; Zenner, Greta M.; Crone, Wendy C.

2006-01-01

247

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

248

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

249

Palaeoclimate: Carbon feedbacks on repeat?  

NASA Astrophysics Data System (ADS)

A period of rapid warming about 55.5 million years ago was triggered by a massive release of carbon. The carbon isotope composition of soil nodules provides evidence for a smaller, but still important, carbon release prior to the main event.

Grimes, Stephen

2015-01-01

250

Development of a carbon-carbon hip prosthesis.  

PubMed

This article deals with the use of carbon-fiber-reinforced-carbon materials for the manufacture of hip prosthesis stems. It considers the manufacturing process of carbon-carbon (C-C) composites made of carbon fibers infiltrated either with dense pyrolytic carbon or silicon carbide (SiC) through chemical vapor infiltration. The chemicophysical properties of these composites are examined according to their structures. The long-term response (2 years) of cortical bone to various types of carbon-carbon was evaluated mainly for bone contact and ingrowth. Carbon-carbon coated with calcium phosphate was found to speed up the bone formation as compared to pyrolytic carbon or SiC coatings. The low modulus of elasticity of the C-C materials could be responsible for quicker bone contact as compared to a much stiffer material like sintered aluminum oxide. The biomechanical performance of C-C hip stems was assessed through (a) implantations into cadaver femurs, (b) fatigue testing, and (c) finite element analysis. These tests showed: (a) a better stress transfer as compared to a metal prosthesis having the same design, (b) no fatigue damage, (c) a computerized stem stress distribution in accordance with the fractures obtained during static mechanical testing. PMID:3624286

Christel, P; Meunier, A; Leclercq, S; Bouquet, P; Buttazzoni, B

1987-08-01

251

Carbon dioxide conversion over carbon-based nanocatalysts.  

PubMed

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

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

2013-07-01

252

Graphene oxide assisted hydrothermal carbonization of carbon hydrates.  

PubMed

Hydrothermal carbonization (HTC) of biomass such as glucose and cellulose typically produces micrometer-sized carbon spheres that are insulating. Adding a very small amount of Graphene oxide (GO) to glucose (e.g., 1:800 weight ratio) can significantly alter the morphology of its HTC product, resulting in more conductive carbon materials with higher degree of carbonization. At low mass loading level of GO, HTC treatment results in dispersed carbon platelets of tens of nanometers in thickness, while at high mass loading levels, free-standing carbon monoliths are obtained. Control experiments with other carbon materials such as graphite, carbon nanotubes, carbon black, and reduced GO show that only GO has significant effect in promoting HTC conversion, likely due to its good water processability, amphiphilicity, and two-dimensional structure that may help to template the initially carbonized materials. GO offers an additional advantage in that its graphene product can act as an in situ heating element to enable further carbonization of the HTC products very rapidly upon microwave irradiation. Similar effect of GO is also observed for the HTC treatment of cellulose. PMID:24298909

Krishnan, Deepti; Raidongia, Kalyan; Shao, Jiaojing; Huang, Jiaxing

2014-01-28

253

Carbon and carbon-14 in lunar soil 14163  

SciTech Connect

Carbon is removed from the surface of lunar soil 14163 size fractions by combustions at 500 and 1000/sup 0/C in an oxygen stream and the carbon contents and the carbon-14 activities are measured. The carbon contents are inversely correlated with grain size. A measured carbon content of 198 ppM for bulk 14163, obtained by combining the size fraction results, is modified to 109 +- 12 ppM by a carbon contamination correction. This value is in accord with a previous determination, 110 ppM, for bulk 14163. The small (< 53 ..mu..) grains of 14163 had more combusted carbon-14 activity, 31.2 +- 2.5 dpm /kg, than the large (> 53 ..mu..) grains, 11.2 +- 2.0 dpm/kg. The combusted carbon and carbon-14 are attributed mainly to solar-wind implantation. Melt extractions of carbon-14 from the combusted soil samples gave essentially identical activities, 21.0 +- 1.5 and 19.2 +- 2.0 dpm/kg for the small and large grains, and are attributed to cosmic-ray spallation-produced carbon-14.

Fireman, E.L.; Stoenner, R.W.

1981-01-01

254

Carbon Sequestered, Carbon Displaced and the Kyoto Context  

SciTech Connect

The integrated system that embraces forest management, forest products, and land-use change impacts the global carbon cycle - and hence the net emission of the greenhouse gas carbon dioxide - in four fundamental ways. Carbon is stored in living and dead biomass, carbon is stored in wood products and landfills, forest products substitute in the market place for products made from other materials, and forest harvests can be used wholly or partially to displace fossil fuels in the energy sector. Implementation of the Kyoto Protocol to the United Nations Framework Convention on Climate Change would result in the creation of international markets for carbon dioxide emissions credits, but the current Kyoto text does not treat all carbon identically. We have developed a carbon accounting model, GORCAM, to examine a variety of scenarios for land management and the production of forest products. In this paper we explore, for two simple scenarios of forest management, the carbon flows that occur and how these might be accounted for under the Kyoto text. The Kyoto protocol raises questions about what activities can result in emissions credits, which carbon reservoirs will be counted, who will receive the credits, and how much credit will be available? The Kyoto Protocol would sometimes give credits for carbon sequestered, but it would always give credits when fossil-fuel carbon dioxide emissions are displaced.

Marland, G.; Schlamadinger, B.

1999-04-18

255

Authigenic carbonate and the history of the global carbon cycle.  

PubMed

We present a framework for interpreting the carbon isotopic composition of sedimentary rocks, which in turn requires a fundamental reinterpretation of the carbon cycle and redox budgets over Earth's history. We propose that authigenic carbonate, produced in sediment pore fluids during early diagenesis, has played a major role in the carbon cycle in the past. This sink constitutes a minor component of the carbon isotope mass balance under the modern, high levels of atmospheric oxygen but was much larger in times of low atmospheric O(2) or widespread marine anoxia. Waxing and waning of a global authigenic carbonate sink helps to explain extreme carbon isotope variations in the Proterozoic, Paleozoic, and Triassic. PMID:23372007

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

2013-02-01

256

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

257

The Global Carbon Cycle Radiative forcing  

E-print Network

The Global Carbon Cycle Radiative forcing Global carbon reservoirs Glacial-interglacial cycles Anthropogenic CO2 Ocean carbon cycle Carbonate chemistry and air-sea equilibrium "Solubility pump due to CO2 #12;Global carbon reservoirs #12;Geologic timescales #12;Pre-industrial Carbon Cycle

Follows, Mick

258

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

259

*** How PAN based Carbon Fibers are  

E-print Network

*** How PAN based Carbon Fibers are Manufactured *** How Carbon Fiber Material Properties are Achieved *** Carbon Fiber Markets/Applications CarbonFiber AerospaceEngineeringGuestLecture: Friday as a Business Development Manager for Amoco's carbon fiber business unit (manufacturers of T-300 carbon fiber

Hu, Hui

260

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.

261

Carbon Capture and Storage, 2008  

SciTech Connect

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.

2009-03-19

262

Natural carbon nanofibers in graphite  

NASA Astrophysics Data System (ADS)

Natural carbon nanofibers have been found in diamond-bearing carbonatites from the Chagatay trachyte-carbonatite complex (Uzbekistan) and described using a series of methods, including SEM, TEM, and Raman spectroscopy. The carbon nanofibers occur as tight aggregates within the host graphite, forming natural bulk nano-structural intergrowths. This is the first description of such carbon nanofibers either in nature or in the laboratory. The data from this study suggest a new possible means of diamond formation. These carbon intergrowths could potentially be used as a model for the fabrication of new types of carbon nanostructural material.

Shumilova, Tatyana Grygoryevna; Isaenko, Sergey Ivanovich; Divaev, Farid Karibovich; Akai, Junji

2012-03-01

263

Carbon dioxide dangers demonstration model  

USGS Publications Warehouse

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

Venezky, Dina; Wessells, Stephen

2010-01-01

264

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

265

Analysis of carbon monoxide.  

PubMed

The degree of exposure to carbon monoxide is most often assessed by measuring the blood carboxyhaemoglobin saturation. This measurement is relevant to investigations of acute accidental or deliberate poisoning and of chronic exposure in a domestic or work place environment. Simple spectrophotometric methods based on differential protein precipitation or dithionite reduction are prone to interference from other haemoglobin pigments and are imprecise for low-level estimations. Automated spectrophotometric devices (CO-oximeters) that estimate simultaneously total haemoglobin, percentage oxyhaemoglobin and percentage carboxyhaemoglobin have acceptable accuracy for carboxyhaemoglobin saturation levels of > 5% and are recommended for most clinical purposes. For the investigation of low-level exposure and the detection of increased haemolysis in neonates, more sensitive methods involving the release of carbon monoxide and its measurement by gas chromatography are required. Gas chromatographic methods are also appropriate when examining post-mortem blood samples where putrefaction or heat stress has resulted in a significant change in haemoglobin composition. PMID:12117442

Widdop, Brian

2002-07-01

266

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

267

California's Future Carbon Flux  

NASA Astrophysics Data System (ADS)

The diversity of the climate and vegetation systems in the state of California provides a unique opportunity to study carton dioxide exchange between the terrestrial biosphere and the atmosphere. In order to accurately calculate the carbon flux, this study couples the sophisticated analytical surface layer model ACASA (Advance Canopy-Atmosphere-Soil Algorithm, developed in the University of California, Davis) with the newest version of mesoscale model WRF (the Weather Research & Forecasting Model, developed by NCAR and several other agencies). As a multilayer, steady state model, ACASA incorporates higher-order representations of vertical temperature variations, CO2 concentration, radiation, wind speed, turbulent statistics, and plant physiology. The WRF-ACASA coupling is designed to identify how multiple environmental factors, in particularly climate variability, population density, and vegetation distribution, impact on future carbon cycle prediction across a wide geographical range such as in California.

Xu, L.; Pyles, R. D.; Paw U, K.; Gertz, M.

2008-12-01

268

Carbon K-edge spectra of carbonate minerals.  

PubMed

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. PMID:20724789

Brandes, Jay A; Wirick, Sue; Jacobsen, Chris

2010-09-01

269

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

270

Carbonate fuel cell matrix  

DOEpatents

A carbonate fuel cell matrix comprising support particles and crack attenuator particles which are made platelet in shape to increase the resistance of the matrix to through cracking. Also disclosed is a matrix having porous crack attenuator particles and a matrix whose crack attenuator particles have a thermal coefficient of expansion which is significantly different from that of the support particles, and a method of making platelet-shaped crack attenuator particles.

Farooque, Mohammad (Huntington, CT); Yuh, Chao-Yi (New Milford, CT)

1996-01-01

271

Carbon nanotube network varactor  

NASA Astrophysics Data System (ADS)

Microelectromechanical system (MEMS) varactors based on a freestanding layer of single-walled carbon nanotube (SWCNT) films were designed, fabricated and tested. The freestanding SWCNT film was employed as a movable upper patch in the parallel plate capacitor of the MEMS. The measurements of the SWCNT varactors show very high tunability, nearly 100%, of the capacitance with a low actuation voltage of 10 V. The functionality of the varactor is improved by implementing a flexible nanocellulose aerogel filling.

Generalov, A. A.; Anoshkin, I. V.; Erdmanis, M.; Lioubtchenko, D. V.; Ovchinnikov, V.; Nasibulin, A. G.; Räisänen, A. V.

2015-01-01

272

Carbon nanotube network varactor.  

PubMed

Microelectromechanical system (MEMS) varactors based on a freestanding layer of single-walled carbon nanotube (SWCNT) films were designed, fabricated and tested. The freestanding SWCNT film was employed as a movable upper patch in the parallel plate capacitor of the MEMS. The measurements of the SWCNT varactors show very high tunability, nearly 100%, of the capacitance with a low actuation voltage of 10 V. The functionality of the varactor is improved by implementing a flexible nanocellulose aerogel filling. PMID:25556375

Generalov, A A; Anoshkin, I V; Erdmanis, M; Lioubtchenko, D V; Ovchinnikov, V; Nasibulin, A G; Räisänen, A V

2015-01-30

273

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

274

Carbon nanotube electronics  

Microsoft Academic Search

Presents experimental results on single-wall carbon nanotube field-effect transistors (CNFETs) operating at gate and drain voltages below 1V. Taking into account the extremely small diameter of the semiconducting tubes used as active components, electrical characteristics are comparable with state-of-the-art metal oxide semiconductor field-effect transistors (MOSFETs). While output as well as subthreshold characteristics resemble those of conventional MOSFETs, we find that

J. Appenzeller; J. Knoch; R. Martel; V. Derycke; S. J. Wind; P. Avouris

2002-01-01

275

[Is carbon disulfide atherogenic?].  

PubMed

The changes in serum lipids and the histopathological aspect of aorta and blood vessels in the coronary, cerebral and renal territories were followed up in the white rat injected intraperitoneally with carbon bisulphide at various doses (5, 10, 15, 25, 75 mg/kg body weight) in subacute and chronic experiment (3, 6, 10 months). The absence of hyperlipemia and atherosclerotic lesions in aorta and coronary, renal and cerebral blood vessels were noticed. PMID:2636775

Mihalache, C; Mihalache, G; P?l?maru, I

1989-01-01

276

Carbonate fuel cell matrix  

DOEpatents

A carbonate fuel cell matrix is described comprising support particles and crack attenuator particles which are made platelet in shape to increase the resistance of the matrix to through cracking. Also disclosed is a matrix having porous crack attenuator particles and a matrix whose crack attenuator particles have a thermal coefficient of expansion which is significantly different from that of the support particles, and a method of making platelet-shaped crack attenuator particles. 8 figs.

Farooque, M.; Yuh, C.Y.

1996-12-03

277

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

278

The effect of carbonization temperature of PAN fiber on the properties of activated carbon fiber composites  

Microsoft Academic Search

The PAN (polyacrylonitrile) based carbon fiber composites were prepared from mixtures of chopped carbon fibers and phenolic resin. Two different carbon fibers were obtained by carbonization of stabilized PAN fiber precursors in nitrogen at 1073 and 1273 K, respectively. Samples of activated carbon fiber composites (ACFCs) were prepared from the carbon fiber composites by activation in carbon dioxide at 1123

J. C. Lee; B. H. Lee; B. G. Kim; M. J. Park; D. Y. Lee; I. H. Kuk; H. Chung; H. S. Kang; H. S. Lee; D. H. Ahn

1997-01-01

279

Electrochimica Acta 52 (2007) 39653975 Elucidating differences between carbon paper and carbon  

E-print Network

of them are carbon-fiber-based porous materials: carbon paper is non-woven, while carbon cloth is wovenElectrochimica Acta 52 (2007) 3965­3975 Elucidating differences between carbon paper and carbon the performance differences between carbon paper (CP) and carbon cloth (CC). Three-dimensional simulations, based

280

Interfaces of propylene carbonate.  

PubMed

Propylene carbonate (PC) wets graphite with a contact angle of 31° at ambient conditions. Molecular dynamics simulations agree with this contact angle after 40% reduction of the strength of graphite-C atom Lennard-Jones interactions with the solvent, relative to the models used initially. A simulated nano-scale PC droplet on graphite displays a pronounced layering tendency and an Aztex pyramid structure for the droplet. Extrapolation of the computed tensions of PC liquid-vapor interface estimates the critical temperature of PC accurately to about 3%. PC molecules lie flat on the PC liquid-vapor surface and tend to project the propyl carbon toward the vapor phase. For close PC neighbors in liquid PC, an important packing motif stacks carbonate planes with the outer oxygen of one molecule snuggled into the positively charged propyl end of another molecule so that neighboring molecule dipole moments are approximately antiparallel. The calculated thermal expansion coefficient and the dielectric constants for liquid PC agree well with experiment. The distribution of PC molecule binding energies is closely Gaussian. Evaluation of the density of the coexisting vapor then permits estimation of the packing contribution to the PC chemical potential and that contribution is about two thirds of the magnitude of the contributions due to attractive interactions, with opposite sign. PMID:23534654

You, Xinli; Chaudhari, Mangesh I; Pratt, Lawrence R; Pesika, Noshir; Aritakula, Kalika M; Rick, Steven W

2013-03-21

281

Interfaces of propylene carbonate  

NASA Astrophysics Data System (ADS)

Propylene carbonate (PC) wets graphite with a contact angle of 31° at ambient conditions. Molecular dynamics simulations agree with this contact angle after 40% reduction of the strength of graphite-C atom Lennard-Jones interactions with the solvent, relative to the models used initially. A simulated nano-scale PC droplet on graphite displays a pronounced layering tendency and an Aztex pyramid structure for the droplet. Extrapolation of the computed tensions of PC liquid-vapor interface estimates the critical temperature of PC accurately to about 3%. PC molecules lie flat on the PC liquid-vapor surface and tend to project the propyl carbon toward the vapor phase. For close PC neighbors in liquid PC, an important packing motif stacks carbonate planes with the outer oxygen of one molecule snuggled into the positively charged propyl end of another molecule so that neighboring molecule dipole moments are approximately antiparallel. The calculated thermal expansion coefficient and the dielectric constants for liquid PC agree well with experiment. The distribution of PC molecule binding energies is closely Gaussian. Evaluation of the density of the coexisting vapor then permits estimation of the packing contribution to the PC chemical potential and that contribution is about two thirds of the magnitude of the contributions due to attractive interactions, with opposite sign.

You, Xinli; Chaudhari, Mangesh I.; Pratt, Lawrence R.; Pesika, Noshir; Aritakula, Kalika M.; Rick, Steven W.

2013-03-01

282

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

283

Structural investigation of carbon/carbon composites by neutron scattering  

NASA Astrophysics Data System (ADS)

Carbon/carbon (C/C) composite material was investigated by means of small-angle as well as wide-angle elastic neutron scattering. The C/C-composites were built up from bi-directionally woven fabrics from PAN-based carbon fibers. Pre-impregnation with phenolic resin was followed by pressure curing and carbonization at 1000 °C and a final heat treatment at either 1800 or 2400 °C. Measurements of the samples were performed in orientations arranging the carbon fibers, respectively, parallel and perpendicular to the incoming beam. Structural features of the fibers as well as the inherently existing pores are presented and the influence of the heat treatment is discussed. The results are compared to earlier X-ray investigations of carbon fibers and C/C-composites.

Prem, Manfred; Krexner, Gerhard; Peterlik, Herwig

2006-11-01

284

An advanced carbon reactor subsystem for carbon dioxide reduction  

NASA Technical Reports Server (NTRS)

An evaluation is presented of the development status of an advanced carbon-reactor subsystem (ACRS) for the production of water and dense, solid carbon from CO2 and hydrogen, as required in physiochemical air revitalization systems for long-duration manned space missions. The ACRS consists of a Sabatier Methanation Reactor (SMR) that reduces CO2 with hydrogen to form methane and water, a gas-liquid separator to remove product water from the methane, and a Carbon Formation Reactor (CFR) to pyrolize methane to carbon and hydrogen; the carbon is recycled to the SMR, while the produce carbon is periodically removed from the CFR. A preprototype ACRS under development for the NASA Space Station is described.

Noyes, Gary P.; Cusick, Robert J.

1986-01-01

285

Natural Carbonation of Peridotite and Applications for Carbon Storage  

NASA Astrophysics Data System (ADS)

Natural carbonation of peridotite in the Samail Ophiolite of Oman is surprisingly rapid and could be further enhanced to provide a safe, permanent method of CO2 storage through in situ formation of carbonate minerals. Carbonate veins form by low-temperature reaction between peridotite and groundwater in a shallow weathering horizon. Reaction with peridotite drives up the pH of the water, and extensive travertine terraces form where this groundwater emerges at the surface in alkaline springs. The potential sink for CO2 in peridotite is enormous: adding 1wt% CO2 to the peridotite in Oman could consume 1/4 of all atmospheric carbon, and several peridotite bodies of comparable size exist throughout the world. Thus carbonation rate and cost, not reservoir size, are the limiting factors on the usefulness of in situ mineral carbonation of peridotite for carbon storage. The carbonate veins in Oman are much younger than previously believed, yielding average 14C ages of 28,000 years. Age data plus estimated volumes of carbonate veins and terraces suggest 10,000 to 100,000 tons per year of CO2 are consumed by these peridotite weathering reactions in Oman. This rate can be enhanced by drilling, hydraulic fracture, injecting CO2-rich fluid, and increasing reaction temperature. Drilling and hydraulic fracture can increase volume of peridotite available for reaction. Additional fracture may occur due to the solid volume increase of the carbonation reaction, and field observations suggest that such reaction-assisted fracture may be responsible for hierarchical carbonate vein networks in peridotite. Natural carbonation of peridotite in Oman occurs at low pCO2, resulting in partial carbonation of peridotite, forming magnesite and serpentine. Raising pCO2 increases carbonation efficiency, forming of magnesite + talc, or at complete carbonation, magnesite + quartz, allowing ˜30wt% CO2 to be added to the peridotite. Increasing the temperature to 185°C can improve the reaction rate by a factor of more than 100,000. Thermal modeling suggests that after an initial heating stage, CO2-rich fluids injected at relatively low temperature can be heated by exothermic carbonation reactions, offsetting diffusive heat loss to maintain optimal temperatures for rapid carbonation without additional energy input. With these enhancements, in situ carbonation could consume more than 1 billion tons of CO2 per cubic kilometer of peridotite per year. Costs associated with this method include drilling, hydraulic fracture, initial heating, CO2 capture and transport, fluid injection and monitoring. The techniques for drilling, fracture and injection are routinely used by oil companies. Compared with other carbon storage methods, in situ mineral carbonation has several advantages. It offers permanent storage that is safer and easier to monitor than storage of CO2-rich fluids in porous underground reservoirs or in the ocean. It may also be less costly than ex situ mineral carbonation, which requires quarrying and transportation of peridotite, grinding and heat treatment, reactions in pressure vessels at elevated temperature, production of catalysts, and disposal of carbonated material. An alternative method, carbonation by reaction of offshore peridotite with shallow seawater rather than CO2-rich fluids, would consume less CO2, but would avoid the costs of CO2 capture and transport inherent in other CCS methods. Drilling to depths where rocks are already close to the optimal carbonation temperature would avoid pre-heating costs and circulate water by thermal convection rather than pumping fluids.

Streit, E.; Kelemen, P.; Matter, J.

2009-05-01

286

Lowstand carbonates, highstand sandstones?  

NASA Astrophysics Data System (ADS)

The sedimentary facies, sediment dynamics and sequence architecture of modern high-energy shelves in the mid and high latitudes are largely governed by wave abrasion processes. Cool-water carbonates may form there, if the influx and/or net accretion of siliciclastics is kept at a minimum. Little dilution of the carbonate produced in situ is generally promoted by a wide "epicontinental" shelf, subdued topography of the adjacent mainland, the predominance of limestone outcrops, and an arid climate. The aforementioned requirements are rarely met, and thus will automatically lead to the formation of mixed siliciclastic-cool-water carbonates. Such an example is found in the Early to Mid-Miocene Lagos-Portimão Formation (Algarve, S-Portugal), which formed on a narrow high-energy shelf of the Atlantic Ocean that was bounded by a mountain range. The sediments of the formation consist of fossiliferous sandstone (FS), shell beds, and rhodolith blankets. Along strike, the stratification of the formation is monotonous for tens of kilometres and well exposed in coastal cliffs, whereas no outcrops of dip sections exist. The bulk skeletal composition of the sediments is typical for the warm-temperate climatic zone: various endo- and epibenthic bivalves, bryozoans, coralline algae, echinoderms, gastropods, and large foraminifers ( Heterostegina). In some very rare beds, a few isolated, not framework-forming specimens of zooxanthellate corals ( Porites, Tarbellastrea) indicate temporally elevated surface water temperatures close to the lower threshold of the coral reef ecosystem. In sandstones, the fauna is well preserved and burrowing bivalves are commonly found in life position. In limestone beds, the state of preservation of the grains ranges from intact to disintegrated and abraded specimens. We infer an accumulation of the shell beds through winnowing of fine materials (siliciclastic sand and carbonate mud) at wave abrasion depth and concentration of calcareous skeletons associated with the subsequent attraction of new epibiota in a complex shell bed. The vertical alternation of fossiliferous sandstone and shell beds, and in-phase variations of the "Photo Index" (photic biota vs. bryozoans) and "Bryozoan Index" (bivalves vs. bryozoans) is envisaged to document variations of water depth (and sea level). Sandstone units built up when wave abrasion depth (WAD) rose above the sea floor during TST (and early HST), whereas the shell beds formed during LST when the WAD for sand intersected with the sea floor. Clastic sediments were probably brought on the outer shelf during early transgression, and by longshore currents. Sea-level signatures inferred in the mixed siliciclastic-cool-water carbonate shelf setting of S-Portugal therefore significantly deviate from conventional concepts of carbonate sequence stratigraphy, which were developed for flat-topped platforms. Successful interpretations of ancient mixed sequences must therefore take into consideration the processes of production, concentration and accretion of the carbonate sediments.

Brachert, T. C.; Forst, M. H.; Pais, J. J.; Legoinha, P.; Reijmer, J. J. G.

2003-01-01

287

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

288

A look at carbonate rocks  

SciTech Connect

Important ore deposits are found in carbonate rocks, and large volumes of oil and gas are also produced from carbonate rocks on a worldwide basis. Reservoir types and productive capability are most often related to rock type and the facies to which the rock belongs. Broad new understanding of carbonate rocks came with the publication of Classification of Carbonate Rocks-A Symposium (AAPG Memoir 1, 1962). The principal parameters of carbonate rocks are (1) chemical composition, (2) grade size, (3) sorting and packing, (4) identification of grains in the rock, (5) cement, (6) color, (7) alteration of recrystallization, and (8) porosity. Original porosity in carbonate rocks relates to kind and packing of original particles. Secondary porosity is reduced by infilling that usually relates to some particles, or is enhanced because some types of grains are dissolved. Carbonate sediments are organic detritus. The range of solubility of organic detritus is very large. Fossils present in the carbonates are clues as to the source of the detritus in the rock. Additional research is needed in faunal relations of facies and of rock types. Ore recovery, well completion, and EOR are more successful when the parameters of carbonate rocks are extensively studied. A simplified approach to carbonate description is discussed.

Bowsher, A.I. (Independent Geologist, Roswell, NM (United States))

1994-03-01

289

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

290

Natural Carbonation of Peridotite and Applications for Carbon Storage  

Microsoft Academic Search

Natural carbonation of peridotite in the Samail Ophiolite of Oman is surprisingly rapid and could be further enhanced to provide a safe, permanent method of CO2 storage through in situ formation of carbonate minerals. Carbonate veins form by low-temperature reaction between peridotite and groundwater in a shallow weathering horizon. Reaction with peridotite drives up the pH of the water, and

E. Streit; P. Kelemen; J. Matter

2009-01-01

291

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

292

Development of improved coating for advanced carbon-carbon components  

NASA Technical Reports Server (NTRS)

Reaction sintered silicon nitride (RSSN) was studied as a substitute coating material on the carbon-carbon material (RCC) presently used as a heat shield on the space shuttle, and on advanced carbon-carbon (ACC), a later development. On RCC, RSSN showed potential in a 538 C (1000 F) screening test in which silicon carbide coated material exhibits its highest oxidation rate; RSSN afforded less protection to ACC because of a larger thermal expansion mismatch. Organosilicon densification and metallic silicon sealing methods were studied as means of further increasing the oxidation resistance of the coating, and some improvement was noted when these methods were employed.

Yamaki, Y. R.; Brown, J. J.

1984-01-01

293

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

294

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

295

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

296

Carbon-Carbon Turbocharger Housing Unit for Intermittent Combustion Engines  

NASA Technical Reports Server (NTRS)

An improved, lightweight, turbine housing unit for an intermittent combustion reciprocating internal combustion engine turbocharger is prepared from a lay-up or molding of carbon-carbon composite materials in a single-piece or two-piece process. When compared to conventional steel or cast iron, the use of carbon-carbon composite materials in a turbine housing unit reduces the overall weight of the engine and reduces the heat energy loss used in the turbocharging process. This reduction in heat energy loss and weight reduction provides for more efficient engine operation.

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

1998-01-01

297

Carbon isotope anomalies in carbonates of the Karelian series  

NASA Astrophysics Data System (ADS)

Results are presented on carbon isotope distributions in carbonates of the Karelian complex. A highly anomalous isotopic composition was found in carbonate rocks aged from 2.6 to 1.9 b.y. In the stromatolitic carbonates of the Onega water table, delta-(C-13) reaches a value of +18 percent, while the shungite layer of the Zaonega horizon is characterized by a wide dispersion (from +7.9 to -11.8 percent). These data are in good agreement with the known geochemical boundary (about 2.2 b.y. ago) in the history of the earth.

Iudovich, Ia. E.; Makarikhin, V. V.; Medvedev, P. V.; Sukhanov, N. V.

1990-07-01

298

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

299

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

300

Carbon Emission Flow in Networks  

PubMed Central

As the human population increases and production expands, energy demand and anthropogenic carbon emission rates have been growing rapidly, and the need to decrease carbon emission levels has drawn increasing attention. The link between energy production and consumption has required the large-scale transport of energy within energy transmission networks. Within this energy flow, there is a virtual circulation of carbon emissions. To understand this circulation and account for the relationship between energy consumption and carbon emissions, this paper introduces the concept of “carbon emission flow in networks” and establishes a method to calculate carbon emission flow in networks. Using an actual analysis of China's energy pattern, the authors discuss the significance of this new concept, not only as a feasible approach but also as an innovative theoretical perspective. PMID:22761988

Kang, Chongqing; Zhou, Tianrui; Chen, Qixin; Xu, Qianyao; Xia, Qing; Ji, Zhen

2012-01-01

301

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

302

Compilation of carbon-14 data  

SciTech Connect

A review and critical analysis was made of the original sources of carbon-14 in the graphite moderator and reflector zones of the eight Hanford production reactors, the present physical and chemical state of the carbon-14, pathways (other than direct combustion) by which the carbon-14 could be released to the biosphere, and the maximum rate at which it might be released under circumstances which idealistically favor the release. Areas of uncertainty are noted and recommendations are made for obtaining additional data in three areas: (1) release rate of carbon-14 from irradiated graphite saturated with aerated water; (2) characterization of carbon-14 deposited outside the moderator and reflector zones; and (3) corrosion/release rate of carbon-14 from irradiated steel and aluminum alloys.

Paasch, R.A.

1985-07-08

303

Fragmentation in Carbon Therapy Beams  

E-print Network

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

Charara, Y M

2010-01-01

304

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

305

Activated carbon from municipal waste  

Microsoft Academic Search

A refuse derived fuel (RDF) was carbonized by partial combustion at 623 K and the carbonized RDF (cRDF) was steam-activated at 1123 K. The cRDF was also treated by 3.3 or 5.2 N nitric acid at a boiling temperature for 3 h prior to the steam-activation. Porous properties of the activated carbons prepared were determined by the nitrogen adsorption method.

S Nagano; H Tamon; T Adzumi; K Nakagawa; T Suzuki

2000-01-01

306

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.

2012-08-03

307

Silicon Encapsulated Carbon Nanotubes  

PubMed Central

A dual stage process of depositing bamboo-like carbon nanotubes (BCNTs) by hot filament chemical vapor deposition (HFCVD) and coating Si using Radio frequency sputtering (RFS) technique. The films were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and electron field emission studies (EFE). SEM results suggest a dense network of homogeneous silicon-coated BCNTs. From the comprehensive analysis of the results provided by these techniques emerges the picture of Si encapsulated BCNTs. PMID:20652067

2010-01-01

308

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

309

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

310

Carbonic anhydrase inhibitors  

Microsoft Academic Search

A novel class of effective CAIs has been identified, starting from a very weak carbonic anhydrase inhibitor (CAI), sulfamide, whose X-ray crystal structure in the adduct with hCA II has recently been reported. A series of N,N-disubstituted- and N-substituted-sulfamides were prepared from the corresponding amines and N-(tert-butoxycarbonyl)-N-[4-(dimethylazaniumylidene)-1,4-dihydropyridin-1-ylsulfonyl]azanide or the unstable N-(tert-butoxycarbonyl)sulfamoyl chloride. The disubstituted compounds being too bulky, were ineffective

Angela Casini; Jean-Yves Winum; Jean-Louis Montero; Andrea Scozzafava; Claudiu T Supuran

2003-01-01

311

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

312

Ultrahigh Carbon Steels  

NASA Astrophysics Data System (ADS)

Recent studies and results on ultrahigh carbon (UHC) steels suggest that major development efforts on these steels are timely and that programs to evaluate prototype structural components should be initiated. These recent results include: the development of economical processing techniques incorporating a divorced eutectoid transformation, the improvement of room temperature strength and ductility by heat treatment, the enhancement of superplastic properties through dilute alloying with silicon, and the attainment of exceptional notch impact strength in laminated UHC steel composites manufactured through solid state bonding. The unique mechanical properties achieved in UHC steels are due to the presence of micron-size fer-rite grains and ultrafine spheroidized carbides.

Sherby, O. D.; Oyama, T.; Kum, D. W.; Walser, B.; Wadsworth, J.

1985-06-01

313

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 particles, such as atomic H or F, in a first chamber. The target particles are directed 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 particles, at or below room temperature, to a point of saturation, in an exposure time interval no longer than about 30 sec.

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

2007-01-01

314

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., H.sub.2 or F.sub.2 or C.sub.nH.sub.m) is irradiated to provide a cold plasma of selected target particles, such as atomic H or F, in a first chamber. The target particles are directed 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 particles, at or below room temperature, to a point of saturation, in an exposure time interval no longer than about 30 sec.

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

2007-01-01

315

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

316

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.

317

Methods of verifying net carbon  

SciTech Connect

Problems currently exist with using net carbon as an industrial standard to gauge smelter performance. First, throughout the industry there are a number of different methods used for determining net carbon. Also, until recently there has not been a viable method to cross check or predict change in net carbon. This inherently leads to differences and most likely inaccuracies when comparing performances of different plants using a net carbon number. Ravenswood uses specific methods when calculating the net carbon balance. The R and D Carbon, Ltd. formula developed by Verner Fisher, et al, to predict and cross check net carbon based on baked carbon core analysis has been successfully used. Another method is used, as a cross check, which is based on the raw materials (cokes and pitch) usage as related to the metal produced. The combination of these methods gives a definitive representation of the carbon performance in the reduction cell. This report details the methods Ravenswood Aluminum uses and the information derived from it.

McClung, M. [Ravenswood Aluminum, WV (United States)

1996-10-01

318

Exploring Marine Carbon Isotope Excursions  

NSDL National Science Digital Library

David Jones, Geology Department, Amherst College Topic: stable isotopes, geochemistry, oceanography, carbon cycle Course type: Upper level undergraduate course Description The exercise is designed to introduce ...

319

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

320

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

321

The Global Carbon Cycle Radiative forcing  

E-print Network

The Global Carbon Cycle Radiative forcing Global carbon reservoirs Glacial-interglacial cycles Anthropogenic CO2 Ocean-atmosphere partitioning Ocean carbon cycle Carbon distribution in the ocean;Geological timescales #12;Present day carbon cycle Gruber & Sarmiento (2002) #12;Glacial

Follows, Mick

322

The Carbon Cycle: How It Works  

NSDL National Science Digital Library

In this game, learners walk through an imaginary Carbon Cycle and explore the ways in which carbon is stored in reservoirs and the processes that transport the carbon atom from one location to another. This resource includes background information about carbon, the carbon cycle, and climate change.

Beverly L. Meier

2012-07-20

323

6, 34193463, 2006 Black carbon or  

E-print Network

), and the early studies on the environmental cycle of "black carbon" (BC) were summarized in the monograph BlackACPD 6, 3419­3463, 2006 Black carbon or brown carbon M. O. Andreae and A. Gelencs´er Title Page Chemistry and Physics Discussions Black carbon or brown carbon? The nature of light-absorbing carbonaceous

Paris-Sud XI, Université de

324

Carbon dioxide consumption during soil development  

Microsoft Academic Search

Carbon is sequestered in soils by accumulation of recalcitrant organic matter and by bicarbonate weathering of silicate minerals. Carbon fixation by ecosystems helps drive weathering processes in soils and that in turn diverts carbon from annual photosynthesis-soil respiration cycling into the long-term geological carbon cycle. To quantify rates of carbon transfer during soil development in moist temperate grassland and desert

Oliver A. Chadwick; Eugene F. Kelly; Dorothy M. Merritts; Ronald G. Amundson

1994-01-01

325

Carbon Management and Implementation Plan 1. Background  

E-print Network

Carbon Management and Implementation Plan 1. Background Energy security and the increasing their part in this and set a carbon target to deliver a 43% reduction in carbon emissions on 2005 levels to the College if it meets the requirements of CIF2 of which delivering carbon reductions through a carbon

Chittka, Lars

326

Biology and chemistry of the carbonic anhydrases  

SciTech Connect

This book contains 10 sections, each consisting of several papers. Some of the paper titles are: The Early Days of Research on Carbonic Anhydrase; Primary Structures and Genetic Changes in Mammalian Carbonic Anhydrase Isozymes; Organization of the Mouse and Human Carbonic Anhydrase II Genes; Isolation of the Chicken Carbonic Anhydrase II Gene; and Origins and Molecular Evolution of the Carbonic Anhydrase Isozymes.

Tashian, R.E.; Hewett-Emmett, D.

1984-01-01

327

Friction stir welding of carbon steels  

Microsoft Academic Search

In order to determine the effect of the carbon content and the transformation on the mechanical properties and microstructures of the FSW carbon steel joints, three types of carbon steels with different carbon contents (IF steel, S12C, S35C) were friction stir welded under various welding conditions. Compared with IF steel, the microstructures and mechanical properties of the carbon steel joints

Hidetoshi Fujii; Ling Cui; Nobuhiro Tsuji; Masakatsu Maeda; Kazuhiro Nakata; Kiyoshi Nogi

2006-01-01

328

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

329

Materials property definition and generation for carbon-carbon and carbon phenolic materials  

NASA Technical Reports Server (NTRS)

A data base program to generate statistically significant material-property data for carbon-carbon and carbon phenolic materials to be used in designs of Space Shuttle is described. The program, which will provide data necessary for thermal and stress modeling of Shuttle nozzle and exit cone structures, includes evaluation of tension, compression, shear strength, shear modulus, thermal expansion, thermal conductivity, permeability, and emittance for both materials; the testing of carbon phenolic materials also includes CTE, off-gassing, pyrolysis, and RTG. Materials to be tested will be excised from Space Shuttle inlet, throat, and exit cone billets and modified involute carbon-carbon exit cones; coprocessed blocks, panels, and cylinders will also be tested.

Canfield, A. R.; Mathis, J. R.; Starrett, H. S.; Koenig, J. R.

1987-01-01

330

Carbon dioxide sequestration in cement kiln dust through mineral carbonation  

SciTech Connect

Carbon sequestration through the formation of carbonates is a potential means to reduce CO{sub 2} emissions. Alkaline industrial solid wastes typically have high mass fractions of reactive oxides that may not require preprocessing, making them an attractive source material for mineral carbonation. The degree of mineral carbonation achievable in cement kiln dust (CKD) under ambient temperatures and pressures was examined through a series of batch and column experiments. The overall extent and potential mechanisms and rate behavior of the carbonation process were assessed through a complementary set of analytical and empirical methods, including mass change, thermal analysis, and X-ray diffraction. The carbonation reactions were carried out primarily through the reaction of CO{sub 2} with Ca(OH){sub 2}, and CaCO{sub 3} was observed as the predominant carbonation product. A sequestration extent of over 60% was observed within 8 h of reaction without any modifications to the waste. Sequestration appears to follow unreacted core model theory where reaction kinetics are controlled by a first-order rate constant at early times; however, as carbonation progresses, the kinetics of the reaction are attenuated by the extent of the reaction due to diffusion control, with the extent of conversion never reaching completion. 35 refs., 3 figs., 1 tab.

Deborah N. Huntzinger; John S. Gierke; S. Komar Kawatra; Timothy C. Eisele; Lawrence L. Sutter [University of Michigan, Ann Arbor, MI (United States). Department of Civil and Environmental Engineering

2009-03-15

331

Demonstration and evaluation of carbon-carbon ion optics  

NASA Astrophysics Data System (ADS)

The principal life-limiting component of ion thrusters is the ion optical used to electrostatically accelerate ionized propellant from the thruster's discharge chamber. An ion optics set consists of two or three thin, closely spaced, multiaperture grids, usually made of molybdenum. Grid lifetime is limited by sputter erosion from ion impingement. Data in the literature show that carbon is five times more resistant to sputter erosion than molybdenum. Carbon in the form of graphite is used for laboratory ion optics but graphite is too fragile for spacecraft use. Use of carbon-carbon composites may enable fabrication of rugged, thermomechanically stable optics with greater lifetime than molybdenum. This article describes a laboratory demonstration of flat, two-grid, 10-cm diameter carbon-carbon optics set, with an evaluation of selected performance characteristic relative to a molybdenum optics set of roughly similar geometry. The carbon-carbon optics delivered stable operation at a cold grid gap of 0.2 mm, an average current density of 2.2 mA/sq cm, and an inferred voltage gradient of 6400 V/mm. Differences observed in the maximum perveance condition, the electron backstreaming limit, and the defocusing limit between the two optics sets were consistent with the known geometrical differences.

Hedges, D. E.; Meserole, J. S.

1994-03-01

332

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

333

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.

michael stapleton

334

Properties of Carbon Nanotubes  

NASA Astrophysics Data System (ADS)

Different synthesizing methods are used to create various nanostructures of carbon; we are mainly interested in single and multi-wall carbon nanotubes, (SWCNTs) and (MWCNTs) respectively. The properties of these tubes are related to their synthetic methods, chirality, and diameter. The extremely sturdy structure of CNTs, with their distinct thermal and electromagnetic properties, suggests a tremendous use of these tubes in electronics and medicines. Here, we analyze various physical properties of SWCNTs with a special emphasis on electromagnetic and chemical properties. By examining their electrical properties, we demonstrate the viability of discrete CNT based components. After considering the advantages of using CNTs over microstructures, we make a case for the advancement and development of nanostructures based electronics. As for current CNT applications, it's hard to overlook their use and functionality in the development of cancer treatment. Whether the tubes are involved in chemotherapeutic drug delivery, molecular imaging and targeting, or photodynamic therapy, we show that the remarkable properties of SWCNTs can be used in advantageous ways by many different industries.

Masood, Samina; Bullmore, Daniel; Duran, Michael; Jacobs, Michael

2012-10-01

335

Carbon dioxide and climate  

SciTech Connect

Scientific and public interest in greenhouse gases, climate warming, and global change virtually exploded in 1988. The Department's focused research on atmospheric CO{sub 2} contributed sound and timely scientific information to the many questions produced by the groundswell of interest and concern. Research projects summarized in this document provided the data base that made timely responses possible, and the contributions from participating scientists are genuinely appreciated. In the past year, the core CO{sub 2} research has continued to improve the scientific knowledge needed to project future atmospheric CO{sub 2} concentrations, to estimate climate sensitivity, and to assess the responses of vegetation to rising concentrations of CO{sub 2} and to climate change. The Carbon Dioxide Research Program's goal is to develop sound scientific information for policy formulation and governmental action in response to changes of atmospheric CO{sub 2}. The Program Summary describes projects funded by the Carbon Dioxide Research Program during FY 1990 and gives a brief overview of objectives, organization, and accomplishments.

Not Available

1990-10-01

336

Carbon nanotube array actuators  

NASA Astrophysics Data System (ADS)

Experimental investigations of highly vertically aligned carbon nanotubes (CNTs), also known as CNT-arrays, are the main focus of this paper. The free strain as result of an active material behavior is analyzed via a novel experimental setup. Previous test experiences of papers made of randomly oriented CNTs, also called Bucky-papers, reveal comparably low free strain. The anisotropy of aligned CNTs promises better performance. Via synthesis techniques like chemical vapor deposition (CVD) or plasma enhanced CVD (PECVD), highly aligned arrays of multi-walled carbon nanotubes (MWCNTs) are synthesized. Two different types of CNT-arrays are analyzed, morphologically first, and optically tested for their active characteristics afterwards. One type of the analyzed arrays features tube lengths of 750-2000 ?m with a large variety of diameters between 20 and 50 nm and a wave-like CNT-shape. The second type features a maximum, almost uniform, length of 12 ?m and a constant diameter of 50 nm. Different CNT-lengths and array types are tested due to their active behavior. As result of the presented tests, it is reported that the quality of orientation is the most decisive property for excellent active behavior. Due to their alignment, CNT-arrays feature the opportunity to clarify the actuation mechanism of architectures made of CNTs.

Geier, S.; Mahrholz, T.; Wierach, P.; Sinapius, M.

2013-09-01

337

Carbon Nanotube Purification  

NASA Technical Reports Server (NTRS)

A method for cleaning or otherwise removing amorphous carbon and other residues that arise in growth of a carbon nanotube (CNT) array. The CNT array is exposed to a plurality of hydroxyls or hydrogen, produced from a selected vapor or liquid source such as H2O or H2O2. and the hydroxyls or hydrogen (neutral or electrically charged) react with the residues to produce partly or fully dissolved or hydrogenated or hydroxylizated products that can be removed or separated from the CNT array. The hydroxyls or hydrogen can be produced by heating the CNT array, residue and selected vapor or liquid source or by application of an electromagnetic excitation signal with a selected frequency or range of frequencies to dissociate the selected vapor or liquid. The excitation frequency can be chirped to cover a selected range of frequencies corresponding to dissociation of the selected vapor or liquid. Sonication may be uscd to supplement dissociation of the H2O and/or H2O2.

Delzeit, Lance D. (Inventor); Delzeit, Clement J. (Inventor)

2005-01-01

338

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

339

Structural graphitic carbon foams  

SciTech Connect

Graphitic carbon foams are a unique material form with very high structural and thermal properties at a light weight. A process has been developed to produce microcellular, open-celled graphitic foams. The process includes heating a mesophase pitch preform above the pitch melting temperature in a pressurized reactor. At the appropriate time, the pressure is released, the gas nucleates bubbles, and these bubbles grow forming the pitch into the foam structure. The resultant foamed pitch is then stabilized in an oxygen environment. At this point a rigid structure exists with some mechanical integrity. The foam is then carbonized to 800 C followed by a graphitization to 2700 C. The shear action from the growing bubbles aligns the graphitic planes along the foam struts to provide the ideal structure for good mechanical properties. Some of these properties have been characterized for some of the foam materials. It is known that variations of the blowing temperature, blowing pressure and saturation time result in foams of variously sized with mostly open pores; however, the mechanism of bubble nucleation is not known. Therefore foams were blown with various gases to begin to determine the nucleation method. These gases are comprised of a variety of molecular weights as well as a range of various solubility levels. By examining the resultant structures of the foam, differences were noted to develop an explanation of the foaming mechanism.

Kearns, K.M.; Anderson, H.J. [Air Force Lab., Wright-Patterson AFB, OH (United States). Materials and Mfg. Directorate

1998-12-31

340

Carbon nanotube computer.  

PubMed

The miniaturization of electronic devices has been the principal driving force behind the semiconductor industry, and has brought about major improvements in computational power and energy efficiency. Although advances with silicon-based electronics continue to be made, alternative technologies are being explored. Digital circuits based on transistors fabricated from carbon nanotubes (CNTs) have the potential to outperform silicon by improving the energy-delay product, a metric of energy efficiency, by more than an order of magnitude. Hence, CNTs are an exciting complement to existing semiconductor technologies. Owing to substantial fundamental imperfections inherent in CNTs, however, only very basic circuit blocks have been demonstrated. Here we show how these imperfections can be overcome, and demonstrate the first computer built entirely using CNT-based transistors. The CNT computer runs an operating system that is capable of multitasking: as a demonstration, we perform counting and integer-sorting simultaneously. In addition, we implement 20 different instructions from the commercial MIPS instruction set to demonstrate the generality of our CNT computer. This experimental demonstration is the most complex carbon-based electronic system yet realized. It is a considerable advance because CNTs are prominent among a variety of emerging technologies that are being considered for the next generation of highly energy-efficient electronic systems. PMID:24067711

Shulaker, Max M; Hills, Gage; Patil, Nishant; Wei, Hai; Chen, Hong-Yu; Wong, H-S Philip; Mitra, Subhasish

2013-09-26

341

Carbon Dioxide Carbonates in the Earth;s Mantle: Implications to the Deep Carbon Cycle  

SciTech Connect

An increase in the ionic character in C-O bonds at high pressures and temperatures is shown by the chemical/phase transformation diagram of CO{sub 2}. The presence of carbonate carbon dioxide (i-CO{sub 2}) near the Earth's core-mantle boundary condition provides insights into both the deep carbon cycle and the transport of atmospheric CO{sub 2} to anhydrous silicates in the mantle and iron core.

Yoo, Choong-Shik; Sengupta, Amartya; Kim, Minseob (Princeton); (WSU)

2012-05-22

342

Carbon Sequestration and Its Role in the Global Carbon Cycle  

NASA Astrophysics Data System (ADS)

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 after year. The findings, published in the 1960s, led to the now iconic Keeling curve and raised several questions about the contribution of fossil fuel burning to atmospheric CO2 concentrations. The AGU monograph Carbon Sequestration and Its Role in the Global Carbon Cycle, edited by Brian J. McPherson and Eric T. Sundquist, moves beyond the “how much?” and “where is it coming from?” of atmospheric CO2 and provides an interdisciplinary look at what we can do to address imbalances in the carbon cycle. In this interview, Eos talks with McPherson.

Schultz, Colin

2011-05-01

343

The kinetics of binding carbon dioxide in magnesium carbonate  

SciTech Connect

Humans currently consume about 6 Gigatons of carbon annually as fossil fuel. In some sense, the coal industry has a unique advantage over many other anthropogenic and natural emitters of CO{sub 2} in that it owns large point sources of CO{sub 2} from which this gas could be isolated and disposed of. If the increased energy demands of a growing world population are to be satisfied from coal, the implementation of sequestration technologies will likely be unavoidable. The authors` method of sequestration involves binding carbon dioxide as magnesium carbonate, a thermodynamically stable solid, for safe and permanent disposal, with minimal environmental impact. The technology is based on extracting magnesium hydroxide from common ultramafic rock for thermal carbonation and subsequent disposition. The economics of the method appear to be promising, however, many details of the proposed process have yet to be optimized. Realization of a cost effective method requires development of optimal technologies for efficient extraction and thermal carbonation.

Butt, D.P.; Lackner, K.S.; Wendt, C.H.; Vaidya, R.; Pile, D.L.; Park, Y.; Holesinger, T.; Harradine, D.M. [Los Alamos National Lab., NM (United States); Nomura, Koji [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.]|[Chichibu Onada Cement Co., Tokyo (Japan)

1998-08-01

344

Intermediate Temperature Carbon - Carbon Composite Structures. CRADA Final Report  

SciTech Connect

The objective of this Cooperative Research and Development Agreement (CRADA) between UT-Battelle, LLC (the "Contractor") and Synterials, Inc. (the "Participant") was to demonstrate promising processing methods, which can lead to producing Carbon-Carbon Composites (CCC), with tensile and interlaminar properties comparable to those of organic matrix composites and environmental stability at 1200 F for long periods of time. The participant synthesized carbon-carbon composites with two different fiber coatings and three different matrices. Both parties evaluated the tensile and interlaminar properties of these materials and characterized the microstructure of the matrices and interfaces. It was found that fiber coatings of carbon and boron carbide provided the best environmental protection and resulted in composites with high tensile strength.

Lara-Curzio, Edgar [ORNL

2007-06-01

345

A study on Low-Carbon City Proper Planning based on Carbon Footprint  

Microsoft Academic Search

The research tool of Carbon Footprint was brought forward to formulate Low-Carbon City Proper Planning better. In order to accommodate the long range and uncertainty in Low-Carbon City Proper planning, for example, Beijing Shijingshan District, all kinds of Carbon Footprint and the capacity of Carbon sink of city proper were calculated and analyzed by the computing method of Carbon Footprint,

Bo Wu; Wei-hua Zeng

2011-01-01

346

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

347

Carbon-Carbon Bond Formation Promoted by Organoruthenium Complexes. The First Unsubstituted  

E-print Network

Carbon-Carbon Bond Formation Promoted by Organoruthenium Complexes. The First Unsubstituted in toluene gives several products resulting from carbon-carbon bond coupling reactions; these include of [Cp*RuCl2]2 with propadiene also leads to a carbon- carbon bond coupling reaction, and the product

Girolami, Gregory S.

348

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

E-print Network

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

Subramanian, Sriram

349

Catalytic engineering of carbon nanostructures  

Microsoft Academic Search

Catalytically grown carbon nanofibers are novel materials that are the product of the decomposition of carbon-containing gases over certain metal surfaces. Studies in our laboratory have demonstrated that the structure and properties of the fibers can be tailored by careful control of a number of parameters including the nature of the metal surface, the composition of the gas-phase reactant, the

A. Chambers; N. M. Rodriguez; K. Baker; R. Terry

1995-01-01

350

Hydrogen storage in carbon nanostructures  

Microsoft Academic Search

Carbon nanotubes have been known for more than 10 years. It is a challenge to fill their unique tubular structure with metals and gases. Especially, the absorption of hydrogen in single wall nanotubes has attracted many research groups worldwide. The values published for the quantity of hydrogen absorbed in nanostructured carbon materials varies between 0.4 and 67 mass%. With the

A. Züttel; P. Sudan; Ph. Mauron; T. Kiyobayashi; Ch. Emmenegger; L. Schlapbach

2002-01-01

351

Closing the fuel carbon cycle  

SciTech Connect

The global carbon cycle involves constant exchange of carbon atoms between the atmosphere, land, and ocean through biological, chemical and geological processes. This natural cycle of uptake and release of carbon is roughly in balance. However, the global industrialization of the past two centuries has released carbon to the atmosphere, mostly in the form of CO{sub 2} that had been locked up in underground coal, oil, and natural gas deposits for millions of years. It is primarily combustion of these long-stored fossil fuels that threatens to tip the balance of the carbon cycle, leading to a substantial buildup of CO{sub 2} in the upper atmosphere. Scientists believe that one key to stabilizing future atmospheric CO{sub 2} concentrations will be essentially to close the fuel carbon cycle, to capture the carbon from fossil fuels before it is released to the atmosphere and return it to permanent reservoirs in the earth or oceans. The article summarises the various options for carbon capture and storage (CCS) and looks at the state of development of technologies. It also addresses regulatory uncertainties, legal issues risks and perceptions of CCS. 3 figs., 1 tab.

Powicki, C.R.

2007-04-01

352

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

353

CARBON NANOTUBES AS MULTIPOLLUTANT SORBENTS  

EPA Science Inventory

Exploratory Research Program Project - Carbon nanotubes (CNTs) are formed from graphite (or graphene) sheets rolled into tubes, typically with diameters of 1 - 10 nm and lengths of 200 - 500 nm. Carbon nanotubes have unique electrical properties that have led to interest in thei...

354

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...

355

DIALKYL CARBONATES AS LUBRICANT ADDITIVES  

Technology Transfer Automated Retrieval System (TEKTRAN)

It has been previously reported that dialkyl carbonates represent attractive lubricants, in part, to their ampiphilic nature and their decomposition to non-corrosive simple alcohols and carbon dioxide. Members of our labs previously examined such materials as additives for biodiesel applications an...

356

Earth's Carbon Metabolism-Revealed  

NSDL National Science Digital Library

In this problem set, learners will use a map of satellite data of Earth's carbon "metabolism" or Net Primary Production to answer a series of questions about carbon removal. Answer key is provided. This is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

357

Carbon budgets in symbiotic associations  

SciTech Connect

Methods are described which permit the estimation of daily budgets for photosynthetically fixed carbon in any alga-invertebrate symbiosis. Included is a method for estimating total daily translocation which does not involve the use of C-14. A daily carbon budget for a shallow water symbiotic reef coral is presented.

Muscatine, L.; Falkowski, P.G.; Dubinsky, Z.

1983-01-01

358

Is Carbon Hard or Soft?  

NSDL National Science Digital Library

The representation shows differences in the arrangement of carbon atoms that make up diamonds and graphite. Through text and pictures, the resource describes the difference in arrangement of two different carbon allotropes. The text relates the differences in arrangements to differences in the hardness (properties) of the materials.

359

Carbon fiber counting. [aircraft structures  

NASA Technical Reports Server (NTRS)

A method was developed for characterizing the number and lengths of carbon fibers accidentally released by the burning of composite portions of civil aircraft structure in a jet fuel fire after an accident. Representative samplings of carbon fibers collected on transparent sticky film were counted from photographic enlargements with a computer aided technique which also provided fiber lengths.

Pride, R. A.

1980-01-01

360

CARBON SEQUESTRATION IN IRRIGATED PASTURES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Carbon sequestration potential for irrigated grazing lands is significant. We measured organic and inorganic carbon stored in southern Idaho soils having long-term land use histories that supported native sagebrush vegetation (NSB), irrigated pasture systems (IP), irrigated conservation tillage sit...

361

CARBON NANOTUBE TRANSISTORS: AN EVALUATION  

E-print Network

CARBON NANOTUBE TRANSISTORS: AN EVALUATION L.C. Castro, D.L. John, and D.L. Pulfrey Department-effect transistors. It is shown that, by appropriate work function engineering of the source, drain and gate contacts-effect transistors, nanotechnology 1. INTRODUCTION Carbon nanotube molecules can be either metallic or semiconducting

Pulfrey, David L.

362

Ongoing transients in carbonate compensation  

Microsoft Academic Search

Uptake of anthropogenic CO2 is acidifying the oceans. Over the next 2000 years, this will modify the dissolution and preservation of sedimentary carbonate. By coupling new formulas for the positions of the calcite saturation horizon, zsat, the compensation depth, zcc, and the snowline, zsnow, to a biogeochemical model of the oceanic carbonate system, we evaluate how these horizons will change

Bernard P. Boudreau; Jack J. Middelburg; Andreas F. Hofmann; Filip J. R. Meysman

2010-01-01

363

Acrylic Precursors for Carbon Fibers  

Microsoft Academic Search

Carbon fibers, owing to their excellent properties such as low density, high stiffness, good resistance toward chemical and environmental effects, and ability to withstand high temperature, find an important place in high-tech areas. with lightweight matrices. They have shown good potential for use as reinforcing agents in light metals such as aluminum and magnesium [1 – 3]. Although carbon fiber

A. K. Gupta; D. K. Paliwal; Pushpa Bajaj

1991-01-01

364

Impregnating Coal With Calcium Carbonate  

NASA Technical Reports Server (NTRS)

Relatively inexpensive process proposed for impregnating coal with calcium carbonate to increase rates of gasification and combustion of coal and to reduce emission of sulfur by trapping sulfur in calcium sulfide. Process involves aqueous-phase reactions between carbon dioxide (contained within pore network of coal) and calcium acetate. Coal impregnated with CO2 by exposing it to CO2 at high pressure.

Sharma, Pramod K.; Voecks, Gerald E.; Gavalas, George R.

1991-01-01

365

4, 317348, 2007 Lateral carbon  

E-print Network

BGD 4, 317­348, 2007 Lateral carbon exchange in a tidal mangrove creek S. Bouillon et al. Title mangrove creek (Ras Dege, Tanzania) S. Bouillon 1,2 , J. J. Middelburg 2 , F. Dehairs 1 , A. V. Borges 3, France 317 #12;BGD 4, 317­348, 2007 Lateral carbon exchange in a tidal mangrove creek S. Bouillon et al

Boyer, Edmond

366

Transport Through Carbon Nanotube Wires  

NASA Technical Reports Server (NTRS)

This viewgraph presentation deals with the use of carbon nanotubes as a transport system. Contact, defects, tubular bend, phonons, and mechanical deformations all contribute to reflection within the nanotube wire. Bragg reflection, however, is native to an ideal energy transport system. Transmission resistance depends primarily on the level of energy present. Finally, the details regarding coupling between carbon nanotubes and simple metals are presented.

Anantram, M. P.; Kwak, Dochan (Technical Monitor)

2001-01-01

367

Diamond-like amorphous carbon  

Microsoft Academic Search

Diamond-like carbon (DLC) is a metastable form of amorphous carbon with significant sp3 bonding. DLC is a semiconductor with a high mechanical hardness, chemical inertness, and optical transparency. This review will describe the deposition methods, deposition mechanisms, characterisation methods, electronic structure, gap states, defects, doping, luminescence, field emission, mechanical properties and some applications of DLCs. The films have widespread applications

J. Robertson

2002-01-01

368

History of ultrahigh carbon steels  

Microsoft Academic Search

The history and development of ultrahigh carbon steels (i.e., steels containing between 1 and 2.l percent C and now known as UHCS) are described. The early use of steel compositions containing carbon contents above the eutectoid level is found in ancient weapons from around the world. For example, both Damascus and Japanese sword steels are hypereutectoid steels. Their manufacture and

J. Wadsworth; O. D. Sherby

1997-01-01

369

21 CFR 582.1137 - Ammonium carbonate.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 2010-04-01 false Ammonium carbonate. 582.1137 Section 582.1137...General Purpose Food Additives § 582.1137 Ammonium carbonate. (a) Product. Ammonium carbonate. (b) Conditions of use....

2010-04-01

370

21 CFR 73.1070 - Calcium carbonate.  

Code of Federal Regulations, 2010 CFR

...1070 Calcium carbonate. (a) Identity. (1) The color additive calcium carbonate is a fine, white, synthetically prepared powder consisting essentially of precipitated calcium carbonate (CaCO3 ). (2) Color additive...

2010-04-01

371

Carbon Fiber Composite Cellular A Dissertation  

E-print Network

Carbon Fiber Composite Cellular Structures ____________________________________ A Dissertation and honeycombs. However, for weight sensitive, ambient temperature applications, carbon fiber composites have emerged as a promising material due to its high specific strength and low density. Carbon fiber reinforced

Wadley, Haydn

372

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

373

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

374

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

375

21 CFR 582.1425 - Magnesium carbonate.  

Code of Federal Regulations, 2014 CFR

... 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

376

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

377

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

378

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.

379

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).

Cinzia Cervato

380

The carbon brace  

PubMed Central

Background The CMCR brace (Corset MonocoqueCarbone respectant la Respiration –which means Monoshell Carbon Brace respecting Breathing) is an innovative brace, used in orthopaedic treatment for progressive thoracic, thoraco-lumbar or combined scoliosis, whatever their etiology. It can be used at the very young age without disrupting the chest growth, but should be kept for reducible scoliosis in older teenagers. Brace description and principles The CMCR brace is monoshell while retaining the corrective principle of the polyvalve Lyon brace with one or two supports (brace “pads”) located on hump(s).In contrast to Lyon brace made of plexidur and structured by metal reinforcement with adjustable but fixed localized supports, the CMCR brace is made of polyethylene and carbon with adjustable and mobile supports. This mobility provides a permanent pressure, which varies depending on ribs and spine movements. The correction is obtained without spinal extension so that each respiratory movement takes part in a gradual return to dorsal kyphosis. Results Results were presented in two published analysis: •?In the first retrospective study about 115 patients, French-published in the Annals of Physical Medicine and Rehabilitation (2005), the CMCR brace stabilized moderate scoliosis, decreased the vital capacity (VC) of 13% compared to the VC without brace, and did not have sufficient impact on the hump reduction. Treatment had better results when started at Risser 3 or 4 than Risser 0, 1, 2. The brace was then modified to increase the dorsal pad pressure and the location of correction forces was defined more precisely through the use of 3D analysis. •?The second study published in Scoliosis (2011) mainly focused on the impact on VC at brace setting up and followed a cohort of 90 patients treated with CMCR. Girls as well as boys increased VC during treatment, and at brace definitive removal, VC had increased of 21% from the initial value, whereas the theoretical VC at the same time rose by 18%. The difference between the time where the child actually wears its brace and the time asked by the clinician for the brace to be worn is only 1 hour, which means that this brace is accepted by teenagers. Conclusions Orthopaedic treatment is still a heavy treatment for teenagers in growth period. This orthosis is designed to partly maintain spine and chest mobility. We hope so to have part in improving life conditions of these teenagers, compared to those treated with rigid braces. PMID:23409701

2013-01-01

381

Natural materials for carbon capture.  

SciTech Connect

Naturally occurring clay minerals provide a distinctive material for carbon capture and carbon dioxide sequestration. Swelling clay minerals, such as the smectite variety, possess an aluminosilicate structure that is controlled by low-charge layers that readily expand to accommodate water molecules and, potentially, carbon dioxide. Recent experimental studies have demonstrated the efficacy of intercalating carbon dioxide in the interlayer of layered clays but little is known about the molecular mechanisms of the process and the extent of carbon capture as a function of clay charge and structure. A series of molecular dynamics simulations and vibrational analyses have been completed to assess the molecular interactions associated with incorporation of CO2 in the interlayer of montmorillonite clay and to help validate the models with experimental observation.

Myshakin, Evgeniy M. (National Energy Technology Laboratory, Pittsburgh, PA); Romanov, Vyacheslav N. (National Energy Technology Laboratory, Pittsburgh, PA); Cygan, Randall Timothy

2010-11-01

382

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

383

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

384

Superconducting properties of carbon nanotubes  

NASA Astrophysics Data System (ADS)

Metallic single wall carbon nanotubes have attracted much interest as 1D quantum wires combining a low carrier density and a high mobility. It was believed for a long time that low temperature transport was exclusively dominated by the existence of unscreened Coulomb interactions leading to an insulating behavior at low temperature. However experiments have also shown evidence of superconductivity in carbon nanotubes. We distinguish two fundamentally different physical situations. When carbon nanotubes are connected to superconducting electrodes, they exhibit proximity induced superconductivity with supercurrents which strongly depend on the transmission of the electrodes. On the other hand intrinsic superconductivity was also observed in suspended ropes of carbon nanotubes and recently in doped individual tubes. These experiments indicate the presence of attractive interactions in carbon nanotubes which overcome Coulomb repulsion at low temperature, and enables investigation of superconductivity in a 1D limit never explored before. To cite this article: M. Ferrier et al., C. R. Physique 10 (2009).

Ferrier, M.; Kasumov, A.; Deblock, R.; Guéron, S.; Bouchiat, H.

2009-05-01

385

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

386

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

387

Carbon dioxide review 1982  

SciTech Connect

The buildup of CO/sub 2/ is a reality, monitored with increasing precision since 1957 and inferred for much earlier dates. A statistical section gives the monitored values to 1980, as well as a review of a long series of measurements made at Mauna Loa by the pioneers of such monitoring, Charles D. Keeling, Robert B. Bacastow, and Timothy P. Whorf. The book discusses internal transport processes in the ocean, of ocean-atmosphere interaction, of the magnitude of forest and soil carbon wastage, of the future course of fossil-fuel consumption. Yet something else emerges, too: if the CO/sub 2/ buildup continues; if the big general circulation models are right about its impact on climate, and if we have not miscalculated the potential role of the oceans, then we face a climatic change in the next century and a half like nothing the post-glacial world, and hence civilized humanity, has seen.

Clark, W.C. (ed.)

1982-01-01

388

Sampling Carbon Dioxide  

NSDL National Science Digital Library

In this lab activity, student teams hypothesize which source has a greater becomes CO² concentration: their breath, auto exhaust, or air in the classroom. They test gas samples from each of these sources, plot data, and hypothesize about the respective role engine exhaust and animal respiration play in contemporary climate change. The lab procedures require Bromthymol Blue indicator solution (BTB), household ammonia, vinegar, and balloons. Links to videos supporting the investigations are provided. This activity is supported by a textbook chapter, "How is Carbon Dioxide Measured?," part of the unit, Climate Change, in Global Systems Science (GSS), an interdisciplinary course for high school students that emphasizes how scientists from a wide variety of fields work together to understand significant problems of global impact.

389

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

390

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

391

Total organic carbon analyzer  

NASA Astrophysics Data System (ADS)

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.

392

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

393

Carbon nanotube actuators  

PubMed

Electromechanical actuators based on sheets of single-walled carbon nanotubes were shown to generate higher stresses than natural muscle and higher strains than high-modulus ferroelectrics. Like natural muscles, the macroscopic actuators are assemblies of billions of individual nanoscale actuators. The actuation mechanism (quantum chemical-based expansion due to electrochemical double-layer charging) does not require ion intercalation, which limits the life and rate of faradaic conducting polymer actuators. Unlike conventional ferroelectric actuators, low operating voltages of a few volts generate large actuator strains. Predictions based on measurements suggest that actuators using optimized nanotube sheets may eventually provide substantially higher work densities per cycle than any previously known technology. PMID:10334985

Baughman; Cui; Zakhidov; Iqbal; Barisci; Spinks; Wallace; Mazzoldi; De Rossi D; Rinzler; Jaschinski; Roth; Kertesz

1999-05-21

394

Graphene: Materially Better Carbon  

SciTech Connect

Graphene, a single atom–thick plane of carbon atoms arranged in a honeycomb lattice, has captivated the attention of physicists, materials scientists, and engineers alike over the five years following its experimental isolation. Graphene is a fundamentally new type of electronic material whose electrons are strictly confined to a two-dimensional plane and exhibit properties akin to those of ultrarelativistic particles. Graphene's two-dimensional form suggests compatibility with conventional wafer processing technology. Extraordinary physical properties, including exceedingly high charge carrier mobility, current-carrying capacity, mechanical strength, and thermal conductivity, make it an enticing candidate for new electronic technologies both within and beyond complementary metal oxide semiconductors (CMOS). Immediate graphene applications include high-speed analog electronics and highly conductive, flexible, transparent thin films for displays and optoelectronics. Currently, much graphene research is focused on generating and tuning a bandgap and on novel device structures that exploit graphene's extraordinary electrical, optical, and mechanical properties.

Fuhrer, M. S.; Lau, C. N.; MacDonald, A. H.

2010-01-01

395

Lightweight Carbon-Carbon High-Temperature Space Radiator  

NASA Technical Reports Server (NTRS)

A document summarizes the development of a carbon-carbon composite radiator for dissipating waste heat from a spacecraft nuclear reactor. The radiator is to be bonded to metal heat pipes and to operate in conjunction with them at a temperature approximately between 500 and 1,000 K. A goal of this development is to reduce the average areal mass density of a radiator to about 2 kg/m(exp 2) from the current value of approximately 10 kg/m(exp 2) characteristic of spacecraft radiators made largely of metals. Accomplishments thus far include: (1) bonding of metal tubes to carbon-carbon material by a carbonization process that includes heating to a temperature of 620 C; (2) verification of the thermal and mechanical integrity of the bonds through pressure-cycling, axial-shear, and bending tests; and (3) construction and testing of two prototype heat-pipe/carbon-carbon-radiator units having different radiator areas, numbers of heat pipes, and areal mass densities. On the basis of the results achieved thus far, it is estimated that optimization of design could yield an areal mass density of 2.2 kg/m (exp 2) close to the goal of 2 kg/m(exp 2).

Miller, W.O.; Shih, Wei

2008-01-01

396

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

397

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

398

The reionization of carbon  

NASA Astrophysics Data System (ADS)

Observations suggest that C II was more abundant than C IV in the intergalactic medium towards the end of the hydrogen reionization epoch (z ˜ 6). This transition provides a unique opportunity to study the enrichment history of intergalactic gas and the growth of the ionizing ultraviolet background (UVB) at early times. We study how carbon absorption evolves from z = 10 to 5 using a cosmological hydrodynamic simulation that includes a self-consistent multifrequency UVB as well as a well-constrained model for galactic outflows to disperse metals. Our predicted UVB is within ˜2-4 times of that from Haardt & Madau, which is fair agreement given the uncertainties. Nonetheless, we use a calibration in post-processing to account for Lyman ? forest measurements while preserving the predicted spectral slope and inhomogeneity. The UVB fluctuates spatially in such a way that it always exceeds the volume average in regions where metals are found. This implies both that a spatially uniform UVB is a poor approximation and that metal absorption is not sensitive to the epoch when H II regions overlap globally even at column densities of 1012 cm-2. We find, consistent with observations, that the C II mass fraction drops to low redshift while C IV rises owing the combined effects of a growing UVB and continued addition of carbon in low-density regions. This is mimicked in absorption statistics, which broadly agree with observations at z = 6-3 while predicting that the absorber column density distributions rise steeply to the lowest observable columns. Our model reproduces the large observed scatter in the number of low-ionization absorbers per sightline, implying that the scatter does not indicate a partially neutral Universe at z ˜ 6.

Finlator, Kristian; Thompson, Robert; Huang, Shuiyao; Davé, Romeel; Zackrisson, E.; Oppenheimer, B. D.

2015-03-01

399

RESEARCH PAPER Amorphous dysprosium carbonate: characterization,  

E-print Network

RESEARCH PAPER Amorphous dysprosium carbonate: characterization, stability, and crystallization earths Á Dysprosium Á Carbonate Á Crystallization Introduction The crystallization of many simple ionic

Benning, Liane G.

400

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

401

The fabrication of artifacts out of glassy carbon and carbon-fiber-reinforced carbon for biomedical applications.  

PubMed

Polymeric carbons are produced by the carbonization of a wide range of organic polymeric systems. We have concentrated on the fabrication of two types of polymeric carbons, glassy carbon and carbon-fiber-reinforced carbon (CFRC), both involving phenolic resin precursors. We describe herein the technology which enables us to make dental implants and heart valves out of glassy carbon. We also show how carbon-fiber-reinforced carbon can be made in the form of rods and plates for orthopedic use and molded before firing to produce complex, rigid, individually sculptured shapes suitable for maxillofacial bone replacement. The mechanical properties will be discussed in relation to the structure of these various forms of polymeric carbon. The main purpose of the work is to show that the technology of polymeric-carbon manufacture is essentially simple and the manufacturing process is readily carried out in laboratories which have already been equipped to fabricate standard dental prostheses. PMID:571441

Jenkins, G M; Grigson, C J

1979-05-01

402

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

403

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

404

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

405

Carbon Nanotube Templated Microfabrication of Porous Silicon-Carbon Materials  

NASA Astrophysics Data System (ADS)

Carbon nanotube templated microfabrication (CNT-M) of porous materials is demonstrated. Partial chemical infiltration of three dimensional carbon nanotube structures with silicon resulted in a mechanically robust material, precisely structured from the 10 nm scale to the 100 micron scale. Nanoscale dimensions are determined by the diameter and spacing of the resulting silicon/carbon nanotubes while the microscale dimensions are controlled by lithographic patterning of the CNT growth catalyst. We demonstrate the utility of this hierarchical structuring approach by using CNT-M to fabricate thin layer chromatography (TLC) separations media with precise microscale channels for fluid flow control and nanoscale porosity for high analyte capacity.

Song, Jun; Jensen, David; Dadson, Andrew; Vail, Michael; Linford, Matthew; Vanfleet, Richard; Davis, Robert

2010-10-01

406

Onion-like carbon and carbon nanotube film antennas  

NASA Astrophysics Data System (ADS)

In this paper, radiating dipole antennas have been fabricated from rolled carbon films, which are typically used for supercapacitor electrodes. Return loss and radiation pattern measurements for onion-like carbon (OLC) and multi-walled carbon nanotubes (MWCNTs) antenna samples are presented and compared to a copper standard. The OLC antenna's radiation pattern measurements show a peak gain of -1.48 dBi, just less than 3 dB of a copper dipole antenna. Compared to antennas made from MWCNT films, the OLC samples show better radiation performance despite a lower measured conductivity.

Vacirca, Nicholas A.; McDonough, John K.; Jost, Kristy; Gogotsi, Yury; Kurzweg, Timothy P.

2013-08-01

407

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

408

Geologic Sequestration of Carbon Dioxide  

NASA Astrophysics Data System (ADS)

Geologic sequestration of carbon dioxide has emerged as one of the most promising options for making deep cuts in carbon dioxide emissions. Geologic sequestration involves the two-step process of first capturing carbon dioxide by separating it from stack emissions, followed by injection and long term storage in deep geologic formations. Sedimentary basins, including depleted oil and gas reservoirs, deep unminable coal seams, and brine-filled formations, provide the most attractive storage reservoirs. Over the past few years significant advances have been made in this technology, including development of simulation models and monitoring systems, implementation of commercial scale demonstration projects, and investigation of natural and industrial analogues for geologic storage of carbon dioxide. While much has been accomplished in a short time, there are many questions that must be answered before this technology can be employed on the scale needed to make significant reductions in carbon dioxide emissions. Questions such as how long must the carbon dioxide remain underground, to what extent will geochemical reactions completely immobilize the carbon dioxide, what can be done in the event that a storage site begins to leak at an unacceptable rate, what is the appropriate risk assessment, regulatory and legal framework, and will the public view this option favorably? This paper will present recent advances in the scientific and technological underpinnings of geologic sequestration and identify areas where additional information is needed.

Benson, S. M.

2003-04-01

409

Method for fabricating composite carbon foam  

DOEpatents

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

Mayer, Steven T. (San Leandro, CA); Pekala, Richard W. (Pleasant Hill, CA); Kaschmitter, James L. (Pleasanton, CA)

2001-01-01

410

Capacitor with a composite carbon foam electrode  

DOEpatents

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

Mayer, Steven T. (San Leandro, CA); Pekala, Richard W. (Pleasant Hill, CA); Kaschmitter, James L. (Pleasanton, CA)

1999-01-01

411

Capacitor with a composite carbon foam electrode  

DOEpatents

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

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

1999-04-27

412

Type Ia Supernova Carbon Footprints  

NASA Astrophysics Data System (ADS)

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 ?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-1) Si II and Ca II features. On the other hand, the light curve properties are preferentially grouped, strongly suggesting a connection between carbon-positivity and broadband light curve/color behavior: three of the five have relatively narrow light curves but also blue colors and a fourth may be a dust-reddened member of this family. Accounting for signal to noise and phase, we estimate that 22+10 - 6% of SNe Ia exhibit spectroscopic C II signatures as late as -5 days with respect to maximum. We place these new objects in the context of previously recognized carbon-positive SNe Ia and consider reasonable scenarios seeking to explain a physical connection between light curve properties and the presence of photospheric carbon. We also examine the detailed evolution of the detected carbon signatures and the surrounding wavelength regions to shed light on the distribution of carbon in the ejecta. Our ability to reconstruct the C II ?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.; Aldering, G.; Antilogus, P.; Aragon, C.; Bailey, S.; Baltay, C.; Bongard, S.; Buton, C.; Canto, A.; Childress, M.; Chotard, N.; Copin, Y.; Fakhouri, H. K.; Gangler, E.; Hsiao, E. Y.; Kerschhaggl, M.; Kowalski, M.; Loken, S.; Nugent, P.; Paech, K.; Pain, R.; Pecontal, E.; Pereira, R.; Perlmutter, S.; Rabinowitz, D.; Rigault, M.; Rubin, D.; Runge, K.; Scalzo, R.; Smadja, G.; Tao, C.; Weaver, B. A.; Wu, C.; Brown, P. J.; Milne, P. A.; Nearby Supernova Factory

2011-12-01

413

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

414

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

415

Carbon films produced from ionic liquid carbon precursors  

DOEpatents

The invention is directed to a method for producing a film of porous carbon, the method comprising carbonizing a film of an ionic liquid, wherein the ionic liquid has the general formula (X.sup.+a).sub.x(Y.sup.-b).sub.y, wherein the variables a and b are, independently, non-zero integers, and the subscript variables x and y are, independently, non-zero integers, such that ax=by, and at least one of X.sup.+ and Y.sup.- possesses at least one carbon-nitrogen unsaturated bond. The invention is also directed to a composition comprising a porous carbon film possessing a nitrogen content of at least 10 atom %.

Dai, Sheng; Luo, Huimin; Lee, Je Seung

2013-11-05

416

Carbon finance and the carbon market in China  

NASA Astrophysics Data System (ADS)

The chinese carbon market is up and running, but private finance has not been fully utilized. Finance-friendly policies are needed to help the world's largest greenhouse-gas emitter to harness market forces for climate change mitigation.

Yu, Xiang; Lo, Alex Y.

2015-01-01

417

Inhibition of catalytic oxidation of carbon/carbon composite materials  

NASA Astrophysics Data System (ADS)

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 determined by temperature programmed oxidation (TPO) and isothermal oxidation in 1 atm O2. The structure and surface chemistry of inhibitor-doped samples were characterized, and the inhibition mechanisms were explored with the help of ab initio molecular orbital calculations. The catalytic effects of KAC or CaAC were found to be dependent on catalyst loading, pretreatment procedure, temperature and O2 partial pressure. Experimental observations showed that K is a more effective catalyst for carbon composite oxidation than Ca as expected from prior studies of catalyzed carbon gasification. This was attributed to its ability to form and maintain good interfacial contact with carbon, as well as to its insensitivity to carbon structure because of its excellent wetting ability and mobility. The experimental results suggested that the interfacial catalyst/carbon contact is the critical factor determining the catalytic effectiveness. Thermally deposited phosphorus, upon heat treatment of P-containing compounds such as CH3OP(OH)2 and POCl3 at around 600°C in the presence of inert gas, exhibited a good inhibition effect in the oxidation of C/C composites used in aircraft brake systems. These P compounds were also effective inhibitors for Ca- or K-catalyzed oxidation. The P loading up to a certain amount (ca. 4.0 wt%) was found to suppress Ca-catalyzed oxidation completely. It also improved the resistance of carbon to K-catalyzed oxidation, but the effect was much less significant than in the case of Ca-catalyzed reaction. The characterization of P-doped carbon samples by XPS, XRD, SEM and TPD and the theoretical explorations by ab initio molecular orbital calculations showed that P doping had no effect on the carbon structure and that oxygen-containing P groups preferentially block the active sites on the carbon surface, thus being responsible for the inhibition effect. Boron doping of the composites at 2500°C was found to have a strong inhibition effect in Ca-catalyzed carbon oxidation and a weak effect in K-catalyzed oxidation. Boron as a dopant was confirmed, by XRD, to enhance the graphitization of the composites. The XPS results supported that the chemical state of doped boron is substitutional, that it is oxidized during carbon oxidation, and that it remains on the carbon surface as boron oxide. The substitutional boron and its oxide appear to have a strong effect on the interfacial contact between the carbon substrate and the catalysts. Accordingly, the catalytic effect of Ca can be almost completely suppressed. (Abstract shortened by UMI.)

Wu, Xianxian

418

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

419

Decrease in Carbon Isotope Rations  

NSDL National Science Digital Library

This three-panel figure is an infographic showing how carbon and oxygen isotope ratios, temperature, and carbonate sediments have changed during the Palaeocene-Eocene Thermal Maximum. The figure caption provides sources to scientific articles from which this data was derived. A graphic visualization from the Intergovernmental Panel on Climate Change shows the rapid decrease in carbon isotope ratios that is indicative of a large increase in the atmospheric greenhouse gases CO2 and CH4, which was coincident with approximately 5C of global warming.

Intergovernmental Panel on Climate Change (IPCC)

420

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

421

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

422

Coral, Carbon Dioxide and Calcification  

NSDL National Science Digital Library

In this group activity, learners act out key stages of the "ocean carbon cycle" (also known as the "carbonate buffer system") through motions, rearranging blocks and team tasks. Learners will also hypothesize the potential effects on the ocean and coral when variables are changed (e.g. the addition of massive amounts of CO2 and increased water temperature). At least 8 learners are needed to participate in the simulation. This detailed lesson plan includes an introduction, background information related to corals and the ocean carbon cycle, and adaptation suggestions for younger learners.

Stephanie L. Anderson

2012-07-17

423

Thermoelectric power in carbon nanotubes  

SciTech Connect

The theoretical results for the temperature dependence of the thermoelectric power of graphite and semimetal carbon nanotubes are reported. In the calculations, the cylindrical superatomic range structure of nanotubes is taken into account. The Boltzmann equation and the {pi}-electron model of semimetal carbon nanotubes are used. The basic parameters of the calculation are the concentration of electrons, the Fermi energy, and the energy of the local level associated with the cylindrical structure of carbon nanotubes. The theoretical results are compared with the available experimental data.

Mavrinskiy, A. V., E-mail: mavrinsky@gmail.com; Baitinger, E. M. [Chelyabinsk State Pedagogical University (Russian Federation)

2009-04-15

424

The biodiversity of carbon assimilation.  

PubMed

As all plastids that have been investigated so far can be traced back to endosymbiotic uptake of cyanobacteria by heterotrophic host cells, they accordingly show a high similarity regarding photosynthesis, which includes both the photosystems and the biochemical reactions around the CO2 fixation via the Calvin-Bassham cycle. Major differences between the different algal and plant groups may include the presence or absence of carbon concentrating mechanisms, pyrenoids, Rubisco activases, carbonic anhydrases as well as differences in the regulation of the Calvin-Bassham cycle. This review describes the diversity of primary carbon fixation steps in algae and plants and the respective regulatory mechanisms. PMID:25239594

Kroth, Peter G

2015-01-01

425

Elastic Moduli of Carbon-Epoxy Composites and Carbon Fibers  

Microsoft Academic Search

All independent elastic moduli of unidirectional carbon-epoxy com posites were measured in the tensile and torsional tests of co-axis and off-axis specimens. The experiments were motivated to estimate the unmeasurable elastic moduli of carbon fiber itself. The experimental results were incorporated with the authors' preceding analytical results which describe the relationships between the moduli of composites and consti tuents. According

Takashi Ishikawa; Kazuo Koyama; Shigeo Kobayashi

1977-01-01

426

Pyrolytic carbon nanotubes from vapor-grown carbon fibers  

Microsoft Academic Search

The structure of as-grown and heat-treated pyrolytic carbon nanotubes (PCNTs) produced by hydrocarbon pyrolysis are discussed on the basis of a possible growth process. The structures are compared with those of nanotubes obtained by the arc method (ACNT; arc-formed carbon nanotubes). PCNTs, with and without secondary pyrolytic deposition (which results in diameter increase) are found to form during pyrolysis of

Morinobu Endo; Kenji Takeuchi; Kiyoharu Kobori; Katsushi Takahashi; Harold W. Kroto; A. Sarkar

1995-01-01

427

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

428

Effect of coupling treatment of carbon fiber surface on mechanical properties of carbon fiber reinforced carbon composites  

Microsoft Academic Search

Unidirectional carbon fiber reinforced carbon composites (C\\/C composites) were prepared from a high modulus-type carbon fiber, treated with either silane or titanate coupling agents, and a furanic resin matrix precursor. Regardless of coupling treatments of fibers, a preferentially oriented region parallel to the fiber surface was observed at the interphase in the carbon matrix derived from furanic resin. The matrix

Norio Iwashita; Eleni Psomiadou; Yoshihiro Sawada

1998-01-01

429

NDE for Characterizing Oxidation Damage in Reinforced Carbon-Carbon  

NASA Technical Reports Server (NTRS)

In this study, coated reinforced carbon-carbon (RCC) samples of similar structure and composition as that from the NASA space shuttle orbiter s thermal protection system were fabricated with slots in their coating simulating craze cracks. These specimens were used to study oxidation damage detection and characterization using NDE methods. These specimens were heat treated in air at 1143 and 1200 C to create cavities in the carbon substrate underneath the coating as oxygen reacted with the carbon and resulted in its consumption. The cavities varied in diameter from approximately 1 to 3 mm. Single-sided NDE methods were used since they might be practical for on-wing inspection, while x-ray micro-computed tomography (CT) was used to measure cavity sizes in order to validate oxidation models under development for carbon-carbon materials. An RCC sample having a naturally-cracked coating and subsequent oxidation damage was also studied with x-ray micro-CT. This effort is a follow-on study to one that characterized NDE methods for assessing oxidation damage in an RCC sample with drilled holes in the coating. The results of that study are briefly reviewed in this article as well. Additionally, a short discussion on the future role of simulation to aid in these studies is provided.

Roth, Don J.; Rauser, Richard W.; Jacobson, nathan S.; Wincheski, Russell A.; Walker, James L.; Cosgriff, Laura A.

2009-01-01

430

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

431

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

432

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

433

The Reionisation of Carbon  

E-print Network

Observations suggest that CII was more abundant than CIV in the intergalactic medium towards the end of the hydrogen reionisation epoch. This transition provides a unique opportunity to study the enrichment history of intergalactic gas and the growth of the ionising background (UVB) at early times. We study how carbon absorption evolves from z=10-5 using a cosmological hydrodynamic simulation that includes a self-consistent multifrequency UVB as well as a well-constrained model for galactic outflows to disperse metals. Our predicted UVB is within 2-4 times that of Haardt & Madau (2012), which is fair agreement given the uncertainties. Nonetheless, we use a calibration in post-processing to account for Lyman-alpha forest measurements while preserving the predicted spectral slope and inhomogeneity. The UVB fluctuates spatially in such a way that it always exceeds the volume average in regions where metals are found. This implies both that a spatially-uniform UVB is a poor approximation and that metal absorp...

Finlator, K; Huang, S; Davé, R; Zackrisson, E; Oppenheimer, B D

2014-01-01

434

Carbon nanotube filters.  

PubMed

Over the past decade of nanotube research, a variety of organized nanotube architectures have been fabricated using chemical vapour deposition. The idea of using nanotube structures in separation technology has been proposed, but building macroscopic structures that have controlled geometric shapes, density and dimensions for specific applications still remains a challenge. Here we report the fabrication of freestanding monolithic uniform macroscopic hollow cylinders having radially aligned carbon nanotube walls, with diameters and lengths up to several centimetres. These cylindrical membranes are used as filters to demonstrate their utility in two important settings: the elimination of multiple components of heavy hydrocarbons from petroleum-a crucial step in post-distillation of crude oil-with a single-step filtering process, and the filtration of bacterial contaminants such as Escherichia coli or the nanometre-sized poliovirus ( approximately 25 nm) from water. These macro filters can be cleaned for repeated filtration through ultrasonication and autoclaving. The exceptional thermal and mechanical stability of nanotubes, and the high surface area, ease and cost-effective fabrication of the nanotube membranes may allow them to compete with ceramic- and polymer-based separation membranes used commercially. PMID:15286755

Srivastava, A; Srivastava, O N; Talapatra, S; Vajtai, R; Ajayan, P M

2004-09-01

435

Carbon Nanotube Electronics  

NASA Astrophysics Data System (ADS)

Carbon nanotubes (CNTs) can be used to build field effect transistors (CNTFETs). Early devices had marginal characteristics due to their large contact resistances. By improving the contacts and utilizing top-gates with thin oxides, we produced CNFETs with characteristics better than those of silicon devices. CNTFETs with as-grown CNTs are invariably p-type. We discuss two methods for p-to-n conversion: a) doping of p-type devices, b) annealing in vacuum to remove adsorbed oxygen. A comparison of these methods shows fundamental differences in the mechanisms of p-to-n- conversion. The key effect of oxygen adsorption is not to dope the tubes, but to modify the barriers at the contacts. A method for controlling these contact barriers will be demonstrated. Having both p-type and n-type CNTFETs we were able to fabricate complementary logic gates. Two types of NOT gates will be presented: an inter-molecular and an intra-molecular. Finally, we will discuss the fabrication of CNTFETs using CNTs bundles containing both metallic and semiconducting CNTs without first removing the metallic nanotubes. Collaborators: J. Appenzeller, P. G. Collins, V. Derycke, R. Martel, and S. Wind.

Avouris, Phaedon

2002-03-01

436

Carbon-free induction furnace  

SciTech Connect

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/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.

1985-10-29

437

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

438

Carbon Monoxide: The Silent Killer  

MedlinePLUS

... and stoves to keep warm or use portable generators without proper ventilation. “This colorless, odorless gas is ... all gas appliances (grills, camp stoves, power tools, generators, etc.) are properly vented so that carbon monoxide ...

439

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

440

Molecular Structure of Carbon Suboxide  

NSDL National Science Digital Library

Carbon Suboxide is a foul-smelling, lachrymatory gas produced by the dehydration of malonic acid, CH2(COOH)2, with P4O10. It is a stable molecule at -78° C, but at 25° C the compound is unstable and it polymerizes to form highly colored solid products. Under the influence of ultraviolet light (in the process known as photolysis), C3O2 decomposes to form the very reactive molecule ketene, C2O. Since carbon suboxide is the acid anhydride of malonic acid, it reacts slowly with water to produce that acid. In the laboratory, carbon suboxide, is widely used as a source of atomic carbon. As a gas it can be stored in a bulb at a pressure of a few mm Hg, but under conditions of standard temperature and pressure (300 K, 1 atm), C3O2 forms a yellow, red, or brown polymer.

2003-06-02

441

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

442

Reducing carbon dioxide to products  

DOEpatents

A method reducing carbon dioxide to one or more products may include steps (A) to (C). Step (A) may bubble said carbon dioxide into a solution of an electrolyte and a catalyst in a divided electrochemical cell. The divided electrochemical cell may include an anode in a first cell compartment and a cathode in a second cell compartment. The cathode may reduce said carbon dioxide into said products. Step (B) may adjust one or more of (a) a cathode material, (b) a surface morphology of said cathode, (c) said electrolyte, (d) a manner in which said carbon dioxide is bubbled, (e), a pH level of said solution, and (f) an electrical potential of said divided electrochemical cell, to vary at least one of (i) which of said products is produced and (ii) a faradaic yield of said products. Step (C) may separate said products from said solution.

Cole, Emily Barton; Sivasankar, Narayanappa; Parajuli, Rishi; Keets, Kate A

2014-09-30

443

Method for making carbon films  

DOEpatents

A method for treating an organic polymer material, preferably a vinylidene chloride/vinyl chloride copolymer (Saran) to produce a flat sheet of carbon film material having a high surface area (.apprxeq.1000 m.sup.2 /g) suitable as an electrode material for super capacitor applications. The method comprises heating a vinylidene chloride/vinyl chloride copolymer film disposed between two spaced apart graphite or ceramic plates to a first temperature of about 160.degree. C. for about 14 hours to form a stabilized vinylidene chloride/vinyl chloride polymer film, thereafter heating the stabilized film to a second temperature of about 750.degree. C. in an inert atmosphere for about one hour to form a carbon film; and finally activating the carbon film to increase the surface area by heating the carbon film in an oxidizing atmosphere to a temperature of at least 750-850.degree. C. for between 1-6 hours.

Tan, Ming X. (Livermore, CA)

1999-01-01

444

NASA Satellite Sees Carbon Dioxide  

NSDL National Science Digital Library

In this problem set, learners will analyze a map of atmospheric carbon dioxide derived from satellite data. Answer key is provided. This is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

445

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

446

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.

Chris Lewis

447

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

448

Method for making carbon films  

DOEpatents

A method for treating an organic polymer material, preferably a vinylidene chloride/vinyl chloride copolymer (Saran) to produce a flat sheet of carbon film material having a high surface area ([approx equal]1000 m[sup 2] /g) suitable as an electrode material for super capacitor applications. The method comprises heating a vinylidene chloride/vinyl chloride copolymer film disposed between two spaced apart graphite or ceramic plates to a first temperature of about 160 C for about 14 hours to form a stabilized vinylidene chloride/vinyl chloride polymer film, thereafter heating the stabilized film to a second temperature of about 750 C in an inert atmosphere for about one hour to form a carbon film; and finally activating the carbon film to increase the surface area by heating the carbon film in an oxidizing atmosphere to a temperature of at least 750--850 C for between 1--6 hours. 2 figs.

Tan, M.X.

1999-07-29

449

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

450

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

451

Carbon Nanotube-Nanocrystal Heterostructures  

SciTech Connect

The importance of generating carbon nanotube-nanoparticle heterostructures is that these composites ought to take advantage of and combine the unique physical and chemical properties of both carbon nanotubes and nanoparticles in one discrete structure. These materials have potential applicability in a range of diverse fields spanning heterogeneous catalysis to optoelectronic device development, of importance to chemists, physicists, materials scientists, and engineers. In this critical review, we present a host of diverse, complementary strategies for the reliable synthesis of carbon nanotube-nanoparticle heterostructures using both covalent as well as non-covalent protocols, incorporating not only single-walled and multi-walled carbon nanotubes but also diverse classes of metallic and semiconducting nanoparticles.

Peng, X.; Wong, S.

2009-04-01

452

Hydrogen adsorption in different carbon nanostructures  

Microsoft Academic Search

Hydrogen adsorption in different carbonaceous materials with optimized structure was investigated at room temperature and 77K. Activated carbon, amorphous carbon nanotubes, SWCNTs and porous carbon samples all show the same adsorption properties. The fast kinetics and complete reversibility of the process indicate that the interaction between hydrogen molecules and the carbon nanostructure is due to physisorption. At 77K the adsorption

Barbara Panella; Michael Hirscher; Siegmar Roth

2005-01-01

453

Sweetness intensity in low-carbonated beverages  

Microsoft Academic Search

The carbonation perception and sweetness perception were investigated under the presence of low level of carbondioxide less than 1.0 gas volume. Carbonation perception decreased linearly as carbonation level decreased. Sweetness perception showed inconsistency by means of evaluation methods: Triangle difference test led the result showing carbonation became a hindrance for sweetness perception. However, the measurement for the sweetness degree expressed

Sachiko Odake

2001-01-01

454

The Taste of Carbonation Jayaram Chandrashekar,1  

E-print Network

,1 William Sly,3 Nicholas J. P. Ryba,2 Charles S. Zuker1 * Carbonated beverages are commonlyThe Taste of Carbonation Jayaram Chandrashekar,1 David Yarmolinsky,1 Lars von Buchholtz,2 Yuki Oka the perception of carbonation in the mouth. In mammals, carbonation elicits both somatosensory and chemosensory

Zuker, Charles

455

Nonlinearity of Carbon Cycle Feedbacks KIRSTEN ZICKFELD  

E-print Network

Nonlinearity of Carbon Cycle Feedbacks KIRSTEN ZICKFELD Canadian Centre for Climate Modelling uptake to CO2 (concentration­carbon cycle feedback) and climate change (climate­carbon cycle feedback) combine linearly. This study explores the linearity in the carbon cycle re- sponse by analyzing

Schmittner, Andreas

456

Carbon Nation RSVP: sustainabilityevents@asu.edu  

E-print Network

Carbon Nation RSVP: sustainabilityevents@asu.edu Parking and directions: sustainability screening of the critically acclaimed documentary Carbon Nation, followed by a question-and-answer session hosted by Carbon Nation Director, Peter Byck. Carbon Nation is an inspirational, optimistic, non

Zhang, Junshan

457

Carbon Cycle Coastal Sensitivity to Sea  

E-print Network

Carbon Cycle Climate Coastal Sensitivity to Sea Level Rise Energy and Socioeconomic Systems Terrestrial Carbon Management Subject Areas New IPCC Tier1 Global Biomass Carbon Map for the Year 2000 these data as: Ruesch, Aaron, and Holly K. Gibbs. 2008. New IPCC Tier1 Global Biomass Carbon Map

458

1. CVD SWNT single-walled carbon  

E-print Network

1. CVD SWNT single-walled carbon nanotube, SWNT SWNT 1993 Iijima SWNT 1) 2) SWNT SWNT 6 SWNT SWNT SWNT 1000 C carbon fiber multi-walled carbon nanotube, MWNT chemical vapor. Sugime, et al : Carbon, 47, 234 (2009). 15) Y. Murakami, et al : Chem. Phys. Lett., 377, 49 (2003). 16) Y

Maruyama, Shigeo

459

Measuring Carbon Sequestration in Pasture Soils  

Technology Transfer Automated Retrieval System (TEKTRAN)

Conversion of croplands to pasture can greatly increase sequestration of carbon in soil organic matter, removing carbon dioxide from the atmosphere and helping to reduce the impacts of climate change. The measurement of soil carbon, and its limitations, could impact future carbon credit programs. ...

460

Energy Prices, Taxes and Carbon Dioxide Emissions  

Microsoft Academic Search

Taxes levied on the carbon content of fuels (carbon taxes) are being considered in many OECD countries as a possible policy instrument to reduce carbon dioxide emissions. This paper first reviews the policy response in Member countries to the threat of global warming. It then discusses the link between carbon emission intensities and current energy prices, touching also on the

Peter Hoeller; Markku Wallin

1991-01-01

461

Carbon fiber manufacturing via plasma technology  

Microsoft Academic Search

The disclosed invention introduces a novel method of manufacturing carbon and\\/or graphite fibers that avoids the high costs associated with conventional carbonization processes. The method of the present invention avoids these costs by utilizing plasma technology in connection with electromagnetic radiation to produce carbon and\\/or graphite fibers from fully or partially stabilized carbon fiber precursors. In general, the stabilized or

Felix L. Paulauskas; Kenneth D. Yarborough; Thomas T. Meek

2002-01-01

462

Global nitrogen deposition and carbon sinks  

Microsoft Academic Search

Land and ocean uptake of carbon dioxide plays a critical role in determining atmospheric carbon dioxide levels. Future increases in nitrogen deposition have been predicted to increase the size of these terrestrial and marine carbon sinks, but although higher rates of nitrogen deposition might enhance carbon uptake in northern and tropical forests, they will probably have less of an impact

Dave S. Reay; Frank Dentener; Pete Smith; John Grace; Richard A. Feely

2008-01-01

463

March 2005 Number 238 CARBON CAPTURE AND  

E-print Network

March 2005 Number 238 CARBON CAPTURE AND STORAGE (CCS) As part of the government's global strategy. This POSTnote discusses the potential of carbon capture and storage (CCS), a method of carbon sequestration2 stages: CO2 capture, transport and storage. CO2 capture Carbon capture is best applied to large

Mather, Tamsin A.

464

Ultimate Isotope Precision for Carbonates Thermo Scientific  

E-print Network

Ultimate Isotope Precision for Carbonates Thermo Scientific KIEL IV Carbonate Device Part of Thermo integration cycle Ultimate Isotope Precision for Carbonates The Thermo Scientific KIEL IV Carbonate DeviceV Thermo Scientific MAT 253 or the 3-kV DELTA V isotope ratio mass spectrometer meets the requirements

Lachniet, Matthew S.

465

Single-Walled Carbon Nanotubes for Nanoelectronics  

E-print Network

CHAPTER 6 Single-Walled Carbon Nanotubes for Nanoelectronics M. S. Fuhrer UNIVERSITY OF MARYLAND . . . . . . . . . . . . 299 1. Synthesis of Single-Walled Carbon Nanotubes . . . . . . . . . . . . . 299 2. Fabrication 1991) (``multi-walled carbon nanotubes'' or MWNTs). Soon thereafter, single-walled carbon nanotubes

Rubloff, Gary W.

466

Carbon Fiber Reinforced Carbon Composite Valve for an Internal Combustion Engine  

NASA Technical Reports Server (NTRS)

A carbon fiber reinforced carbon composite valve for internal combustion engines and the like formed of continuous carbon fibers throughout the valve's stem and head is disclosed. The valve includes braided carbon fiber material over axially aligned unidirectional carbon fibers forming a valve stem; the braided and unidirectional carbon fibers being broomed out at one end of the valve stem forming the shape of the valve head; the valve-shaped structure being densified and rigidized with a matrix of carbon containing discontinuous carbon fibers: and the finished valve being treated to resist oxidation. Also disclosed is a carbon matrix plug containing continuous and discontinuous carbon fibers and forming a net-shape valve head acting as a mandrel over which the unidirectional and braided carbon fibers are formed according to textile processes. Also disclosed are various preform valves and processes for making finished and preform carbon fiber reinforced carbon composite valves.

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

1999-01-01

467

Hydrogen storage in carbon nanostructures  

Microsoft Academic Search

The paper gives a critical review of the literature on hydrogen storage in carbon nanostructures. Furthermore, the hydrogen storage of graphite, graphite nanofibers (GNFs), and single-walled carbon nanotubes (SWNTs) was measured by thermal desorption spectroscopy (TDS). The samples were ball milled under Ar or D2 atmosphere in order to modify the microstructure which was characterized by X-ray diffraction, scanning electron

M Hirscher; M Becher; M Haluska; A Quintel; V Skakalova; Y.-M Choi; U Dettlaff-Weglikowska; S Roth; I Stepanek; P Bernier; A Leonhardt; J Fink

2002-01-01

468

Overview of Nanotechnology: Carbon Nanotubes  

NSDL National Science Digital Library

This overview of nanotechnology is presented by the NaMCATE project. Carbon nanotubes are "cylindrical molecules with a diameter as small as 1 nm and a length up to several millimeters. Consisting only of carbon atoms, they are cylinders made of a single layer of graphene." This lesson provides both an overview of nanotubes and a powerpoint presentation.Users must create a free login in order to access materials.

2011-09-21

469

The carbon footprint of bread  

Microsoft Academic Search

Background, aim, and scope  The aim of this study has been to estimate the carbon footprint of bread produced and consumed in the UK. Sliced white and\\u000a wholemeal bread has been considered for these purposes and the functional unit is defined as “one loaf of sliced bread (800 g)\\u000a consumed at home”. The influence on the carbon footprint of several parameters has

Namy Espinoza-Orias; Heinz Stichnothe; Adisa Azapagic

2011-01-01

470

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

471

Recuperative supercritical carbon dioxide cycle  

DOEpatents

A power plant includes a closed loop, supercritical carbon dioxide system (CLS-CO.sub.2 system). The CLS-CO.sub.2 system includes a turbine-generator and a high temperature recuperator (HTR) that is arranged to receive expanded carbon dioxide from the turbine-generator. The HTR includes a plurality of heat exchangers that define respective heat exchange areas. At least two of the heat exchangers have different heat exchange areas.

Sonwane, Chandrashekhar; Sprouse, Kenneth M; Subbaraman, Ganesan; O'Connor, George M; Johnson, Gregory A

2014-11-18

472

Selective functionalization of carbon nanotubes  

NASA Technical Reports Server (NTRS)

The present invention is directed toward methods of selectively functionalizing carbon nanotubes of a specific type or range of types, based on their electronic properties, using diazonium chemistry. The present invention is also directed toward methods of separating carbon nanotubes into populations of specific types or range(s) of types via selective functionalization and electrophoresis, and also to the novel compositions generated by such separations.

Strano, Michael S. (Inventor); Usrey, Monica (Inventor); Barone, Paul (Inventor); Dyke, Christopher A. (Inventor); Tour, James M. (Inventor); Kittrell, W. Carter (Inventor); Hauge, Robert H. (Inventor); Smalley, Richard E. (Inventor)

2009-01-01

473

Targeting a low carbon estate.  

PubMed

Sustainability specialists within global professional services consultancy Arup have developed a statistical model based on Carbon Trust-collated data that they believe will enable owners and occupiers of even large estates to identify the most cost-effective means of improving their buildings' sustainability both now and in the future. As senior engineer Thomas Briault explains, the model, developed to address the Climate Change Act's 2050 carbon reduction targets, will even factor in such uncertain aspects as future economic growth. PMID:19911557

Briault, Thomas

2009-10-01

474

Carbon Dioxide - Sources and Sinks  

NSDL National Science Digital Library

In this lab activity, students use a chemical indicator (bromothymol blue) to detect the presence of carbon dioxide in animal and plant respiration and in the burning of fossil fuels and its absence in the products of plant photosynthesis. After completing the five parts of this activity, students compare the colors of the chemical indicator in each part and interpret the results in terms of the qualitative importance of carbon sinks and sources.

Universe, Windows T.

475

Dinosaur Breath - Learning about the Carbon Cycle  

NSDL National Science Digital Library

This activity illustrates the carbon cycle using an age-appropriate hook, and it includes thorough discussion and hands-on experimentation. Students learn about the geological (ancient) carbon cycle, they investigate the role of dinosaurs in the carbon cycle, and the eventual storage of carbon in the form of chalk. Students discover how the carbon cycle has been occurring for millions of years and is necessary for life on Earth. Finally, they may extend their knowledge to the concept of global warming and how engineers are working to understand the carbon cycle and reduce harmful carbon dioxide emissions.

2007-01-01

476

Dinosaur Breath - Learning about the Carbon Cycle  

NSDL National Science Digital Library

This activity illustrates the carbon cycle using an age-appropriate hook, and it includes thorough discussion and hands-on experimentation. Students learn about the geological (ancient) carbon cycle; they investigate the role of dinosaurs in the carbon cycle, and the eventual storage of carbon in the form of chalk. Students discover how the carbon cycle has been occurring for millions of years and is necessary for life on Earth. Finally, they may extend their knowledge to the concept of global warming and how engineers are working to understand the carbon cycle and reduce harmful carbon dioxide emissions.

Cooper, Lauren; Zarske, Malinda S.; Yowell, Janet; Teachengineering - Integrated Teaching And Learning Program, Cu B.

477

UHV outgassing measurements on various carbons.  

NASA Technical Reports Server (NTRS)

Mass spectral analyses were made of gases desorbed from carbon samples at increasing temperatures up to 2200 K. Samples were initially outgassed above 2000 K, exposed to air for several hours at room temperature, and then tested in ultrahigh vacuum following a 24-hr bake at 300 C. Four forms of carbon tested were pyrolytic carbon, Grafoil, vitreous carbon, and pyrolyzed-phenolic fibers. The equivalent of several monolayers of gas (mostly H2 and CO) are evolved from all of the carbons except vitreous carbon. Less than a monolayer of gas is evolved from vitreous carbon during outgassing to 2000 K.

Beitel, G. A.; Benson, D. K.

1973-01-01

478

Carbon nanoscrolls by pyrolysis of a polymer  

NASA Astrophysics Data System (ADS)

3D network of carbon nanoscrolls was synthesized starting from pyrolysis of poly(acrylic acid-co-maleic acid) sodium salt. It is a catalyst-free process where pyrolysis of polymer leads to formation of carbon form and sodium carbonate. Upon water soaking of pyrolysis product, the carbon form undergoes self-assembly to form carbon nanoscrolls. The interlayer distance between the walls of carbon nanoscroll was found to be 0.34 nm and the carbon nanoscrolls exhibited a surface area of 188 m2/g as measured by the BET method.

Yadav, Prasad; Warule, Sambhaji; Jog, Jyoti; Ogale, Satishchandra

2012-12-01

479

Electronic transport in amorphous carbon  

SciTech Connect

Electronic transport in a-C films has been the subject of considerable debate. In this study, combined stress relaxation and electrical transport studies were used to identify the transport mechanism in a-C films prepared by pulsed-laser deposition. The stress relaxation was modeled by a first-order kinetic reaction involving transformation of 4-fold coordinated carbon atoms to 3-fold coordinated carbon atoms, and the distribution of activation energies for this process was determined. The activation energies were found to range from about 1 eV to over 2 eV, and using these activation energies, the increase in 3-fold carbon concentration with time-temperature annealing was obtained. Conductivity measurements were also performed as a function of time-temperature annealing. It was found that the conductivity of a-C films is exponentially proportional to increases in 3-fold carbon concentration. This result can be explained by thermally activated hopping along carbon 3-fold chains combined with chain-to-chain tunneling. From the data, a typical chain length was estimated to consist of 13 carbon atoms. The heterogeneous nature of the conductivity may explain the spatially localized electron emission which is observed in a-C assuming a tunnel barrier emission model.

Sullivan, J.P.; Friedmann, T.A.

1997-12-01

480

Carbon sequestration research and development  

SciTech Connect

Predictions of global energy use in the next century suggest a continued increase in carbon emissions and rising concentrations of carbon dioxide (CO{sub 2}) 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'' energy scenario that future global emissions of CO{sub 2} to the atmosphere will increase from 7.4 billion tonnes of carbon (GtC) per year in 1997 to approximately 26 GtC/year by 2100. IPCC also projects a doubling of atmospheric CO{sub 2} concentration by the middle of next century and growing rates of increase beyond. Although the effects of increased CO{sub 2} levels on global climate are uncertain, many scientists agree that a doubling of atmospheric CO{sub 2} concentrations could have a variety of serious environmental consequences. The goal of this report is to identify key areas for research and development (R&D) that could lead to an understanding of the potential for future use of carbon sequestration as a major tool for managing carbon emissions. Under the leadership of DOE, researchers from universities, industry, other government agencies, and DOE national laboratories were brought together to develop the technical basis for conceiving a science and technology road map. That effort has resulted in this report, which develops much of the information needed for the road map.

Reichle, Dave; Houghton, John; Kane, Bob; Ekmann, Jim; and others

1999-12-31

481

Sequestration of Soil Carbon as Secondary Carbonates (Invited)  

NASA Astrophysics Data System (ADS)

Rattan Lal Carbon Management and Sequestration Center The Ohio State University Columbus, OH 43210 USA Abstract World soils, the major carbon (C) reservoir among the terrestrial pools, contain soil organic C (SOC) and soil inorganic C (SIC). The SIC pool is predominant in soils of arid and semi-arid regions. These regions cover a land area of about 4.9x109 ha. The SIC pool in soils containing calcic and petrocalcic horizons is estimated at about 695-748 Pg (Pg = 1015 g = 1 gigaton) to 1-m depth. There are two types of carbonates. Lithogenic or primary carbonates are formed from weathering of carbonaceous rocks. Pedogenic or secondary carbonates are formed by dissolution of CO2 in the soil air to form carbonic acid and precipitation as carbonates of Ca+2 or Mg+2. It is the availability of Ca+2 or Mg+2 from outside the ecosystem that is essential to sequester atmospheric CO2. Common among outside sources of Ca+2 or Mg+2 are irrigation water, aerial deposition, sea breeze, fertilizers, manure and other amendments. The decomposition of SOC and root respiration may increase the partial pressure of CO2 in the soil air and lead to the formation of HCO_3^- upon dissolution in H20. Precipitation of secondary carbonates may result from decreased partial pressure of CO2 in the sub-soil, increased concentration of Ca+2, Mg+2 and HCO_3^- in soil solution, and decreased soil moisture content by evapotranspiration. Transport of bicarbonates in irrigated soils and subsequent precipitation above the ground water (calcrete), activity of termites and other soil fauna, and management of urban soils lead to formation of secondary carbonates. On a geologic time scale, weathering of silicate minerals and transport of the by-products into the ocean is a geological process of sequestration of atmospheric CO2. Factors affecting formation of secondary carbonates include land use, and soil and crop management including application of biosolids, irrigation and the quality of irrigation water, activity and species diversity of soil biota, management of soil fertility and application of Ca-bearing amendments (e.g., lime, single and triple super phosphate, manure), and adoption of conservation-effective measures which trap alluvial and aeolian sediments. Even the low rate of formation of secondary carbonates at 2-5 kg C/ha/yr has implications to aggregation, and microbiological and regolith properties. The isotropic composition of secondary carbonates is a useful tool for reconstructing paleoecological conditions. Researchable priorities include: 1) assessment of the depth distribution of CO2 concentration in soil air and its spatial and temporal variation in relation to tillage systems, crop residue management, fertilizer and manuring, irrigation, cover cropping, agroforestry, etc., 2) understanding the effects of micro and meso-climate (e.g., rainfall, evapotranspiration, air and soil temperatures) on CO2 concentration in soil air, 3) determination of the relation between soil profile characteristics (texture, structure, horizonation, hydrology) and secondary carbonates at present and under paleoecological conditions, 4) establishing the relationship between SOC and SIC pools, 5) determination of the impacts of deforestation, biomass burning, wild fires, drought, inundation, etc., on SIC dynamics, and 6) evaluating the effects of secondary carbonates on soil aggregation and water retention.

Lal, R.

2013-12-01

482

Gravimetric Determination of Inorganic Carbon in Calcareous Soils Using the Carbonate-Meter  

Technology Transfer Automated Retrieval System (TEKTRAN)

Organic carbon affects many important physical, chemical and microbiological soil properties. In calcareous soils, the inorganic carbon has to be measured and subtracted from the total carbon to obtain organic carbon. Our objective was to develop a gravimetric technique to quantify inorganic carbon ...

483

Mechanistical studies on the formation of carbon dioxide in extraterrestrial carbon monoxide ice analog samples  

E-print Network

Mechanistical studies on the formation of carbon dioxide in extraterrestrial carbon monoxide ice with extraterrestrial, carbon monoxide bearing ices. The chemical modifications were monitored on line and in situ via of carbon monoxide and on the formation of carbon dioxide in extraterrestrial ice analog samples. 1

Kaiser, Ralf I.

484

Black Carbon in the Soil Carbon Cycle: Is it an Oxidation Resistant End-Product?  

E-print Network

Black Carbon in the Soil Carbon Cycle: Is it an Oxidation Resistant End-Product? Simone;1 Introduction Soils represent a large carbon pool in the global carbon cycle. Estimates suggest that this pool is twice as large as the atmospheric pool. But its role in the global carbon cycle remains unclear

Fischlin, Andreas

485

Carbon13 variations in the dissolved inorganic carbon in estuarine waters  

Microsoft Academic Search

The stable carbon isotope composition of dissolved inorganic carbon [DIC] was measured in Tampa Bay and Florida Bay. The dependence of isotopic composition was evaluated in terms of atmospheric CO2 exchange, carbon exchange between fresh water and seawater (i.e. salinity) and DIC derived from the reaction between calcium carbonate and organically derived CO2. The extent of organic carbon oxidation and

William M. Sackett; Toedsit Netratanawong; M. Elizabeth Holmes

1997-01-01

486

Mar., 1955 GASIFICATIONOF CARBONRODSWITH CARBONDIOXIDE 241 GASIFICATION OF CARBON RODS WITH CARBON DIOXIDE1*2  

E-print Network

Mar., 1955 GASIFICATIONOF CARBONRODSWITH CARBONDIOXIDE 241 GASIFICATION OF CARBON RODS WITH CARBON commercial carbons and their gasification rates with carbon dioxide at a series of temperatures between 900. No general correlation between these properties and the carbon gasification rates was found. Introduction

487

Low carbon spaces: area-based carbon emission reduction -a scoping study  

E-print Network

carbon emission reductions, but to date most strategic thinking has focused on national policy leversLow carbon spaces: area-based carbon emission reduction - a scoping study 02.06.02 #12;1 Low Carbon Spaces Area-Based Carbon Emission Reduction: A Scoping Study Prepared for the Sustainable Development

488

University of Glasgow Carbon Management Programme Carbon Management Plan working with  

E-print Network

fully in the initiatives which will help us reduce our carbon footprint and combat climate changeUniversity of Glasgow Carbon Management Programme Carbon Management Plan working with Page 1 Carbon Management Programme Carbon Management Plan (CMP) Albert Young, 3 November 2009 #12;University of Glasgow

Mottram, Nigel

489

Structural annealing of carbon coated aligned multi-walled carbon nanotube sheets  

E-print Network

by chem- ical vapor infiltration (CVI) of carbon source gases into fiber preforms. While CVI of carbon fasteners [1]. While the above applications are currently filled by traditional carbon fiber C/ C compositesStructural annealing of carbon coated aligned multi-walled carbon nanotube sheets Shaghayegh Faraji

Zhu, Yuntian T.

490

Improved fracture toughness of carbon fiber composite functionalized with multi walled carbon nanotubes  

E-print Network

Improved fracture toughness of carbon fiber composite functionalized with multi walled carbon August 2008 A B S T R A C T Woven carbon fiber (CF) laminae are functionalized in situ with carbon nanotubes (CNTs) to test the hypothesis that growing CNTs on CF (i.e., carbon fiber bundles or tow) would

Bennett, Gisele

491

PERGAMON Carbon 39 (2001) 369373 Effect of carbon fiber grade on the electrical behavior of  

E-print Network

PERGAMON Carbon 39 (2001) 369­373 Effect of carbon fiber grade on the electrical behavior of carbon 2000 Abstract Electrical conduction in cement reinforced by short carbon fibers below the percolation is decreased by increasing the fiber crystallinity, but is increased by using intercalated fibers. The carbon

Chung, Deborah D.L.

492

Deoiled asphalt as carbon source for preparation of various carbon materials by chemical vapor deposition  

Microsoft Academic Search

Various carbon materials, including vapor grown carbon fibers (VGCFs) and carbon trees, were synthesized by chemical vapor deposition in argon atmosphere, using deoiled asphalt as carbon source and ferrocene as catalyst. Pure carbon microbeads (CMBs) were also obtained by this method in the absence of ferrocene. The influence of different growth parameters, such as ferrocene content, reaction temperature, retention time

Xuguang Liu; Yongzhen Yang; Xian Lin; Bingshe Xu; Yan Zhang

2006-01-01

493

Carbonate rock depositional models: A microfacies approach  

SciTech Connect

Carbonate rocks contain more than 50% by weight carbonate minerals such as calcite, dolomite, and siderite. Understanding how these rocks form can lead to more efficient methods of petroleum exploration. Micofacies analysis techniques can be used as a method of predicting models of sedimentation for carbonate rocks. Micofacies in carbonate rocks can be seen clearly only in thin sections under a microscope. This section analysis of carbonate rocks is a tool that can be used to understand depositional environments, diagenetic evolution of carbonate rocks, and the formation of porosity and permeability in carbonate rocks. The use of micofacies analysis techniques is applied to understanding the origin and formation of carbonate ramps, carbonate platforms, and carbonate slopes and basins. This book will be of interest to students and professionals concerned with the disciplines of sedimentary petrology, sedimentology, petroleum geology, and palentology.

Carozzi, A.V.

1988-01-01

494

Scale-up of Carbon/Carbon Bipolar Plates  

SciTech Connect

This project was focused upon developing a unique material technology for use in PEM fuel cell bipolar plates. The carbon/carbon composite material developed in this program is uniquely suited for use in fuel cell systems, as it is lightweight, highly conductive and corrosion resistant. The project further focused upon developing the manufacturing methodology to cost-effectively produce this material for use in commercial fuel cell systems. United Technology Fuel Cells Corp., a leading fuel cell developer was a subcontractor to the project was interested in the performance and low-cost potential of the material. The accomplishments of the program included the development and testing of a low-cost, fully molded, net-shape carbon-carbon bipolar plate. The process to cost-effectively manufacture these carbon-carbon bipolar plates was focused on extensively in this program. Key areas for cost-reduction that received attention in this program was net-shape molding of the detailed flow structures according to end-user design. Correlations between feature detail and process parameters were formed so that mold tooling could be accurately designed to meet a variety of flow field dimensions. A cost model was developed that predicted the cost of manufacture for the product in near-term volumes and long-term volumes (10+ million units per year). Because the roduct uses lowcost raw materials in quantities that are less than competitive tech, it was found that the cost of the product in high volume can be less than with other plate echnologies, and can meet the DOE goal of $4/kW for transportation applications. The excellent performance of the all-carbon plate in net shape was verified in fuel cell testing. Performance equivalent to much higher cost, fully machined graphite plates was found.

David P. Haack

2009-04-08

495

Leaf Impressions: A Model for Carbonization  

NSDL National Science Digital Library

In this activity students make leaf impressions on paper to illustrate how carbonization works. They use the leaf press method to demonstrate staining as a model for carbonization, when living tissue leaves a carbon film in sediment and rock. The students will discover that many plant fossils are preserved through carbonization and that soft parts of animals including skin and fur have also been preserved as fossils through the process of carbonization.

Greb, Stephen

496

Dust to Dust: The Carbon Cycle  

NSDL National Science Digital Library

This case study examines the carbon cycle: from carbon becoming carbon dioxide, to carbohydrate, to animals, then back to carbon dioxide again. Chemistry topics like atomic structures, carbon isotopes, radiocarbon dating, beta decay, half-life and photosynthesis are explained. The case study and teaching notes may be downloaded in PDF format. The site also includes a section for instructor feedback where general comments may be read and contributed.

Anderson, Jennifer Y.; Chen, Ling; Wang, Diane

2011-01-04

497

Carbonic Acid Retreatment of Biomass  

SciTech Connect

This project sought to address six objectives, outlined below. The objectives were met through the completion of ten tasks. (1) Solidify the theoretical understanding of the binary CO{sub 2}/H{sub 2}O system at reaction temperatures and pressures. The thermodynamics of pH prediction have been improved to include a more rigorous treatment of non-ideal gas phases. However it was found that experimental attempts to confirm theoretical pH predictions were still off by a factor of about 1.8 pH units. Arrhenius experiments were carried out and the activation energy for carbonic acid appears to be substantially similar to sulfuric acid. Titration experiments have not yet confirmed or quantified the buffering or acid suppression effects of carbonic acid on biomass. (2) Modify the carbonic acid pretreatment severity function to include the effect of endogenous acid formation and carbonate buffering, if necessary. It was found that the existing severity functions serve adequately to account for endogenous acid production and carbonate effects. (3) Quantify the production of soluble carbohydrates at different reaction conditions and severity. Results show that carbonic acid has little effect on increasing soluble carbohydrate concentrations for pretreated aspen wood, compared to pretreatment with water alone. This appears to be connected to the release of endogenous acids by the substrate. A less acidic substrate such as corn stover would derive benefit from the use of carbonic acid. (4) Quantify the production of microbial inhibitors at selected reaction conditions and severity. It was found that the release of inhibitors was correlated to reaction severity and that carbonic acid did not appear to increase or decrease inhibition compared to pretreatment with water alone. (5) Assess the reactivity to enzymatic hydrolysis of material pretreated at selected reaction conditions and severity. Enzymatic hydrolysis rates increased with severity, but no advantage was detected for the use of carbonic acid compared to water alone. (6) Determine optimal conditions for carbonic acid pretreatment of aspen wood. Optimal severities appeared to be in the mid range tested. ASPEN-Plus modeling and economic analysis of the process indicate that the process could be cost competitive with sulfuric acid if the concentration of solids in the pretreatment is maintained very high ({approx}50%). Lower solids concentrations result in larger reactors that become expensive to construct for high pressure applications.

Baylor university

2003-06-01

498

Carbonic Acid Pretreatment of Biomass  

SciTech Connect

This project sought to address six objectives, outlined below. The objectives were met through the completion of ten tasks. 1) Solidify the theoretical understanding of the binary CO2/H2O system at reaction temperatures and pressures. The thermodynamics of pH prediction have been improved to include a more rigorous treatment of non-ideal gas phases. However it was found that experimental attempts to confirm theoretical pH predictions were still off by a factor of about 1.8 pH units. Arrhenius experiments were carried out and the activation energy for carbonic acid appears to be substantially similar to sulfuric acid. Titration experiments have not yet confirmed or quantified the buffering or acid suppression effects of carbonic acid on biomass. 2) Modify the carbonic acid pretreatment severity function to include the effect of endogenous acid formation and carbonate buffering, if necessary. It was found that the existing severity functions serve adequately to account for endogenous acid production and carbonate effects. 3) Quantify the production of soluble carbohydrates at different reaction conditions and severity. Results show that carbonic acid has little effect on increasing soluble carbohydrate concentrations for pretreated aspen wood, compared to pretreatment with water alone. This appears to be connected to the release of endogenous acids by the substrate. A less acidic substrate such as corn stover would derive benefit from the use of carbonic acid. 4) Quantify the production of microbial inhibitors at selected reaction conditions and severity. It was found that the release of inhibitors was correlated to reaction severity and that carbonic acid did not appear to increase or decrease inhibition compared to pretreatment with water alone. 5) Assess the reactivity to enzymatic hydrolysis of material pretreated at selected reaction conditions and severity. Enzymatic hydrolysis rates increased with severity, but no advantage was detected for the use of carbonic acid compared to water alone. 6) Determine optimal conditions for carbonic acid pretreatment of aspen wood. Optimal severities appeared to be in the mid range tested. ASPEN-Plus modeling and economic analysis of the process indicate that the process could be cost competitive with sulfuric acid if the concentration of solids in the pretreatment is maintained very high (~50%). Lower solids concentrations result in larger reactors that become expensive to construct for high pressure applications.

G. Peter van Walsum; Kemantha Jayawardhana; Damon Yourchisin; Robert McWilliams; Vanessa Castleberry

2003-05-31

499

Carbon dioxide sequestration by ex-situ mineral carbonation  

SciTech Connect

The process developed for carbon dioxide sequestration utilizes a slurry of water mixed with olivine- forsterite end member (Mg{sub 2}SiO{sub 4}), which is reacted with supercritical CO{sub 2} to produce magnesite (MgCO{sub 3}). Carbon dioxide is dissolved in water to form carbonic acid, which likely dissociates to H{sup +} and HCO{sub 3}{sup -}. The H{sup +} hydrolyzes the silicate mineral, freeing the cation (Mg{sup 2+}), which reacts with the HCO{sub 3}{sup -} to form the solid carbonate. Results of the baseline tests, conducted on ground products of the natural mineral, have demonstrated that the kinetics of the reaction are slow at ambient temperature (22 degrees C) and subcritical CO{sub 2} pressures (below 7.4 MPa). However, at elevated temperature and pressure, coupled with continuous stirring of the slurry and gas dispersion within the water column, significant conversion to the carbonate occurs. Extent of reaction is roughly 90% within 24 h, at 185 degrees C and partial pressure of CO{sub 2} (P{sub CO{sub 2}}) of 11.6 MPa. Current studies suggest that reaction kinetics can be improved by pretreatment of the mineral, catalysis of the reaction, and/or solution modification. Subsequent tests are intended to examine these options, as well as other mineral groups.

O'Connor, W.K.; Dahlin, D.C.; Turner, P.C.; and Walters, R.P.

2000-01-01

500

[Organic carbon and carbon mineralization characteristics in nature forestry soil].  

PubMed

Through field investigation and indoor analysis, the organic carbon content and organic carbon mineralization characteristics of six kinds of natural forest soil were studied, including the pine forests, evergreen broad-leaved forest, deciduous broad-leaved forest, mixed needle leaf and Korean pine and Chinese pine forest. The results showed that the organic carbon content in the forest soil showed trends of gradual decrease with the increase of soil depth; Double exponential equation fitted well with the organic carbon mineralization process in natural forest soil, accurately reflecting the mineralization reaction characteristics of the natural forest soil. Natural forest soil in each layer had the same mineralization reaction trend, but different intensity. Among them, the reaction intensity in the 0-10 cm soil of the Korean pine forest was the highest, and the intensities of mineralization reaction in its lower layers were also significantly higher than those in the same layers of other natural forest soil; comparison of soil mineralization characteristics of the deciduous broad-leaved forest and coniferous and broad-leaved mixed forest found that the differences of litter species had a relatively strong impact on the active organic carbon content in soil, leading to different characteristics of mineralization reaction. PMID:24881403

Yang, Tian; Dai, Wei; An, Xiao-Juan; Pang, Huan; Zou, Jian-Mei; Zhang, Rui

2014-03-01