Slurry burner for mixture of carbonaceous material and water

Science.gov (United States)

Nodd, D.G.; Walker, R.J.

1985-11-05

The present invention is intended to overcome the limitations of the prior art by providing a fuel burner particularly adapted for the combustion of carbonaceous material-water slurries which includes a stationary high pressure tip-emulsion atomizer which directs a uniform fuel into a shearing air flow as the carbonaceous material-water slurry is directed into a combustion chamber, inhibits the collection of unburned fuel upon and within the atomizer, reduces the slurry to a collection of fine particles upon discharge into the combustion chamber, and regulates the operating temperature of the burner as well as primary air flow about the burner and into the combustion chamber for improved combustion efficiency, no atomizer plugging and enhanced flame stability.

Distilling solid carbonaceous materials

Energy Technology Data Exchange (ETDEWEB)

Nielsen, H; Laing, B

1926-12-04

In a process of distilling solid carbonaceous materials with by-product recovery, the time factor and the temperature gradient during the distillation period are so controlled that a temperature difference exceeding 150/sup 0/C is avoided between the temperatures at the center and periphery of any suitable size of material or thickness of fuel bed. The material is heated by direct contact with an inert gas, such as water gas, producer gas, or combustion gases, which is passed in counterflow to the material and whose volume is such as to lower the vapor tension or partial pressure of the volatilizable oils and to withdraw the oils without cracking of the oil vapors. The material may be subjected to a preliminary heat treatment by gases containing 2 to 3 percent of free oxygen to reduce its coking properties, and free oxygen may be added either to the heating gases during the heat treatment, or to the retort and heating gases and vapors to polymerize resinous bodies prior to condensation or during condensation and while the oils are still wholly or partially in the vapor state.

Immobilization of pentachlorophenol in soil using carbonaceous material amendments

Energy Technology Data Exchange (ETDEWEB)

Wen Bei [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road, Haidian District, Beijing 100085 (China)], E-mail: bwen@rcees.ac.cn; Li Ruijuan; Zhang Shuzhen [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road, Haidian District, Beijing 100085 (China); Shan Xiaoquan [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road, Haidian District, Beijing 100085 (China)], E-mail: xiaoquan@rcees.ac.cn; Fang Jing; Xiao Ke [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road, Haidian District, Beijing 100085 (China); Khan, Shahamat U. [Department of Chemistry and Biochemistry, MSN 3E2, George Mason University, 4400 University Drive, Fairfax, VA 22030-4444 (United States)

2009-03-15

In this study, three pentachlorophenol (PCP) laboratory-spiked and one field-contaminated soil were amended with 2.0% char, humic acid (HA) and peat, respectively. The amended soils were aged for either 7 or 250 days. After amendment, CaCl{sub 2} extractability of PCP was significantly decreased. Desorption kinetics indicated that the proposed amendment could lead to a strong binding and slow desorption of PCP in soils. Amendment with char reduced the bioaccumulation factor (BAF) of PCP most significantly for earthworms (Eisenia fetida) in all soils studied. The results of both physicochemical and biological tests suggested that amendment reduced PCP bioavailability quickly and enduringly, implying that carbonaceous material amendment, especially char amendment, was a potentially attractive in situ remediation method for sequestration of PCP in contaminated soil. - Carbonaceous material amendment was a potential in situ remediation method for pentachlorophenol contaminated soil.

Origin and nature of carbonaceous material in the galaxy

Energy Technology Data Exchange (ETDEWEB)

Hoyle, F; Wickramasinghe, N C [University Coll. of South Wales and Monmouthshire, Cardiff (UK)

1977-12-22

It is stated that astronomers generally believe that the carbonaceous material emerging from stars must be in the form of graphite, the most stable condensed form of carbon, and that such emergence must be confined to situations where the C/O ratio exceeds unity, such as in the atmospheres of carbon stars. It is argued here, however, that whilst this state of affairs remains valid for mass flows from stars of sufficiently low surface temperatures, it is not correct for low density flows from stars with colour temperatures approximately > 4,000 K (or for oscillatory stars with colour temperatures that go above 4,000 K for a portion of their cycle). In the latter case it is shown that carbonaceous material comprised mainly of polysaccharides will be able to condense. Implications for the origin of life on the Earth are discussed.

Pressure hydrogenation of solid carbonaceous material

Energy Technology Data Exchange (ETDEWEB)

Pier, M; Kroenig, W

1942-09-28

A process is described for the continuous pressure hydrogenation of solid, nonfusible carbonaceous material, such as coal, oil shale, or peat, in a pasted condition, characterized in that the charge is heated in a known way under pressure, together with water, nearly to the reaction temperature, then it is led into a pressure vessel, whose volume amounts to 20 to 40% of the usual reaction space without any change at the same temperature, and the charge then goes through the reaction vessel, after which its temperature is raised to the reaction height.

Hydrocarbon oils from carbonaceous material

Energy Technology Data Exchange (ETDEWEB)

Fletcher, J

1943-01-28

Carbonaceous material is subjected to gradually increasing temperature in a retort and the gases and vapours are drawn off through four pipes according to their temperature and are passed respectively to a separate bubble tower or a fractionation column. The condensate and overhead from each bubble tower are refluxed in the bubble tower into which the gases and vapours of the next succeeding higher temperature are passed and the condensates and overheads from the bubble tower into which gases and vapours at the highest of the lower temperatures are passed are refluxed in the fractionation column. The waste products of combustion pass to a boiler for generating steam for the fractional plant.

Preg-robbing of Gold by Carbonaceous Materials Encountered in ...

African Journals Online (AJOL)

Processing of gold from refractory ores containing carbonaceous materials (CM) poses challenges due to the ability of the CM to preg-rob dissolved gold. Depending on the type and maturity of CM encountered, preg-robbing of aurocyanide ion can lead to reduction in gold recovery ranging from a few percentages to more ...

Reactions on carbonaceous materials with hydrogenating gases

Energy Technology Data Exchange (ETDEWEB)

Pier, M; Simon, W; Kronig, W

1933-02-08

A process is given for the production of valuable hydrocarbons by treatment of distillable carbonaceous materials with added hydrogenating gases under pressure in contact with catalysts. The process comprises adding to the initial materials before or during the said treatment organic sulphonic acids together with metals of groups 4 to 8 of the periodic system or compounds thereof, or free organic carboxylic acids which when inorganic salts are simultaneously present do not combine therewith to form complex ansolvo acids, or acid salts of strong acids or acid salts of heavy metals, lithium, magnesium, and aluminum, with the exception of aluminum hydrosilicates, or inorganic oxygen containing acids of sulfur or nitrogen or the anhydrides of said inorganic oxygen-containing acids.

Review of the technology for solar gasification of carbonaceous materials

International Nuclear Information System (INIS)

Epstein, M.; Spiewak, I.; Funken, K.H.; Ortner, J.

1994-01-01

Research has demonstrated the feasibility of solar assisted gasification of carbonaceous materials to form synthesis gas (syngas). The potential feedstocks range from natural gas, residual oil, biomass, and oil-shale to coal. The expected advantages of such processing are yields of syngas with calorific values above those of the carbonaceous feedstocks, syngas quality suited to production of hydrogen, methanol or bulk Fischer-Tropsch fuels, and the ability to process low-grade and waste materials with essentially no emissions to atmosphere other than small amounts of CO 2 . The review provides some background on solar receiver concepts to reach the high temperatures needed for syngas production, the basic chemistry involved, covers applicable experiments that have been reported with solar inputs and with conventional heating, heat transfer processes, process and energy balances, and cost analysis. Approximately 80 references are cited. The authors present their views on the most promising approaches to solar-assisted gasification, the technology development required, and the ultimate benefits of such development and commercialization

Preparation of a Sulfonated Carbonaceous Material from Lignosulfonate and Its Usefulness as an Esterification Catalyst

Directory of Open Access Journals (Sweden)

Duckhee Lee

2013-07-01

Full Text Available Sulfonated carbonaceous material useful as a solid acid catalyst was prepared from lignosulfonate, a waste of the paper-making industry sulfite pulping process, and characterized by 13C-NMR, FT-IR, TGA, SEM and elemental analysis, etc. The sulfonic acid group density and total density of all acid groups in the sulfonated carbonaceous material was determined by titration to be 1.24 mmol/g and 5.90 mmol/g, respectively. Its catalytic activity in the esterification of cyclohexanecarboxylic acid with anhydrous ethanol was shown to be comparable to that of the ionic exchange resin Amberlyst-15, when they were used in the same amount. In the meantime, the sulfonic acid group was found to be leached out by 26%–29% after it was exposed to hot water (95 °C for 5 h. The catalytic usefulness of the prepared carbonaceous material was investigated by performing esterifications.

Lithium storage into carbonaceous materials obtained from sugarcane bagasse

International Nuclear Information System (INIS)

Matsubara, Elaine Y.; Lala, Stella M.; Rosolen, Jose Mauricio

2010-01-01

Carbonaceous materials with different structures are prepared by carbonization of sugarcane bagasse. Depending on carbonization conditions, it is possible to obtain soot rich in flakes or in honeycomb-shaped micrometric particles, whose concentration has large influence on lithium storage into electrodes. The soot rich in honeycomb-shaped particles provides the best electrochemical performance, with a reversible specific capacity of 310 mAh g -1 . The results suggest that the sugarcane bagasse can be potentially used in the design of anodic materials for lithium ion batteries. (author)

Process of producing carbonaceous materials; reaction with hydrogen gases

Energy Technology Data Exchange (ETDEWEB)

1933-01-13

A process is described for the production of valuable hydrocarbons by treating distillable carbonaceous materials together with hydrogen gases, under pressure and in contact with catalysts, the process consisting in adding to the original materials, first or during treatment, organic sulfonic acids together with metals from the fourth or eighth groups of the periodic system or a combination of these, or organic carbosilicic acids or inorganic acids containing oxides of sulfur or nitrogen or the anhydrides of these inorganic acids or variation of these compounds.

Distilling solid carbonaceous materials

Energy Technology Data Exchange (ETDEWEB)

Nielsen, H; Laing, B

1926-12-04

In the distillation of solid carbonaceous materials with by-product recovery by direct heating with a gas such as water gas, producer gas, or combustion gas which is passed in counter-flow to the materials, the volume of the gas used is such as to lower the vapor tension of the volatiles to enable the oil vapor to be liberated at temperatures not exceeding 450 to 500/sup 0/C and so that the gaseous mixture may be cooled to from 80 to 100/sup 0/C without causing the highest boiling oil fraction to condense. Coking coals may be subjected to a preliminary heat treatment with gases containing an oxygen content of from 2 to 8 percent to reduce their coking properties, and oxygen may be added to the heating gases to assist the polymerization of resinous bodies. Lubricating oil may be obtained by treating the primary oil with caustic soda to remove tar acids, refining the residue with sulfuric acid, distilling off 25 percent of the refined oil and passing the remainder through a filter press at -5/sup 0/C to extract the paraffin wax. The residue of wax-free oil is distilled to yield a lubricating oil which at normal temperatures has a static coefficient of friction of from .1 to .185. Other specifications are referred to.

Extracting solid carbonaceous materials with solvents

Energy Technology Data Exchange (ETDEWEB)

1936-02-08

Solvent extraction of solid carbonaceous materials is performed in the presence of powdered catalysts together with alkaline substances. Oxides of nickel or iron or nickel nitrate have been used together with caustic soda or potash solutions or milk of lime. Solvents used include benzenes, middle oils, tars, tetrahydronaphthalene. The extraction is performed at 200 to 500/sup 0/C under pressures of 20 to 200 atm. Finely ground peat was dried and mixed with milk of lime and nickel nitrate and an equal quantity of middle oil. The mixture was heated for 3 h at 380/sup 0/C at 90 atm. 88.5% of the peat was extracted. In a similar treatment brown coal was impregnated with solutions of caustic soda and ferric chloride.

Removal of blue indigo and cadmium present in aqueous solutions using a modified zeolitic material and an activated carbonaceous material

International Nuclear Information System (INIS)

Gutierrez S, E. E.

2011-01-01

In the last years the use of water has been increased substantially, it has been also altered its quality as a result of human activities such as mining, industrial activities and others. Water pollution caused by dyes and heavy metals has adverse effects on the environment, since both pollutants are very persisten even after conventional treatments. Denim blue and cadmium are not biodegradable. There is a growing interest in finding new, efficient and low cost alternative materials to remove such pollutants from the aqueous medium. The purpose of this work was to evaluate a modified zeolitic tuff and an activated carbonaceous material obtained from the pyrolysis of sewage sludge for the removal of denim blue and cadmium. The zeolitic material was modified with Na + and Fe 3+ solutions to improve its sorption properties for the removal of cadmium and denim blue, respectively. Carbonaceous material was treated with 10% HCl solution to remove ashes. Both materials were characterized by scanning electron microscopy and elemental analysis (EDS), specific surface areas (Bet), thermogravimetric analysis, infrared spectroscopy and X-ray diffraction. Simultaneously, the denim blue dye was characterized by infrared spectroscopy and its pKa value was determined, these data allowed the determination of its chemical properties and its acid-base behavior in solution. In the content of this work the term indigo blue was changed by denim blue, as it corresponds to the commercial name of the dye. To assess the sorption capacity of sorbents, the sorption kinetics and sorption isotherms in batch system were determined; the results were fitted to mathematical models such as the pseudo-first order, pseudo second order and second order to describe the sorption kinetics and the Langmuir, Freundlich and Langmuir-Freundlich isotherms to describe sorption processes. The results show that the most efficient material to remove denim blue from aqueous solutions is the carbonaceous material

Recent Development of Carbonaceous Materials for Lithium–Sulphur Batteries

Directory of Open Access Journals (Sweden)

Xingxing Gu

2016-11-01

Full Text Available The effects of climate change are just beginning to be felt, and as such, society must work towards strategies of reducing humanity’s impact on the environment. Due to the fact that energy production is one of the primary contributors to greenhouse gas emissions, it is obvious that more environmentally friendly sources of power are required. Technologies such as solar and wind power are constantly being improved through research; however, as these technologies are often sporadic in their power generation, efforts must be made to establish ways to store this sustainable energy when conditions for generation are not ideal. Battery storage is one possible supplement to these renewable energy technologies; however, as current Li-ion technology is reaching its theoretical capacity, new battery technology must be investigated. Lithium–sulphur (Li–S batteries are receiving much attention as a potential replacement for Li-ion batteries due to their superior capacity, and also their abundant and environmentally benign active materials. In the spirit of environmental harm minimization, efforts have been made to use sustainable carbonaceous materials for applications as carbon–sulphur (C–S composite cathodes, carbon interlayers, and carbon-modified separators. This work reports on the various applications of carbonaceous materials applied to Li–S batteries, and provides perspectives for the future development of Li–S batteries with the aim of preparing a high energy density, environmentally friendly, and sustainable sulphur-based cathode with long cycle life.

Biomass-derived carbonaceous materials as components in wood briquettes

Energy Technology Data Exchange (ETDEWEB)

Stengl, S.; Koch, C.; Stadlbauer, E.A.; Scheer, J. [Univ. of Applied Sciences, THM Campus Giessen, Giessen (Germany); Weber, B. [Instituto de Ingenieria de la Universidad Nacional Autonoma de Mexico (UNAM), Coyoacan (Mexico); Strohal, U.; Fey, J. [Strohal Anlagenbau, Staufenberg (Germany)

2012-11-01

The present paper describes a briquette composed of a substantial amount of wooden biomass and up to 35% of carbonaceous materials derived from biogenic residues. The cellulosic component may be a mixture of any wooden residue. Suitable substrates for the carbonaceous fraction are vegetation wastes from land management or agriculture. Depending on physical and chemical nature of the substrate, Hydrothermal Carbonisation (HTC) or Low Temperature Conversion (LTC) may be used to produce the carbonaceous part of the briquette. HTC turns wet biomass at temperatures around 200 deg C in an autoclave into lignite whereas LTC treatment at 400 deg C and atmospheric pressure produces black coal. This is manifested by a molar ratio of 0.1 {<=} H/C (LTC) {<=} 0.7; 0.05{<=} O/C (LTC) {<=} 0.4 and 0.7 < H/C (HTC) <1.5 ; 0.2< O/C (HTC) < 0.5. Solid state {sup 13}C-NMR confirms these findings showing a strong absorption band for sp{sup 2}-hybridized carbon atoms at chemical shifts of 100 ppm und 165 ppm for LTC biochar. Depending on the substrate, HTC gives rise to an increase in the specific calorific value (MJ/kg) by a factor of {Psi} {approx} 1.2 - 1.4; LTC by 1.5 - 1.8. In addition ash melting points are significantly increased; in case of wheat straw by about 200 deg C. Compacted products may have a cylindrical or rectangular profile.

Characterization and performance of carbonaceous materials obtained from exhausted sludges for the anaerobic biodecolorization of the azo dye Acid Orange II

Energy Technology Data Exchange (ETDEWEB)

Athalathil, S.; Stüber, F.; Bengoa, C.; Font, J. [Departament d’Enginyeria Quimica, ETSEQ, Universitat Rovira i Virgili, Av. Paisos Catalans 26, 43007 Tarragona, Catalunya (Spain); Fortuny, A. [Departament d’Enginyeria Quimica, EPSEVG, Universitat Politecnica de Catalunya, Av. Victor Balaguer s/n, 08800 Vilanova i la Geltru, Catalunya (Spain); Fabregat, A., E-mail: azael.fabregat@urv.cat [Departament d’Enginyeria Quimica, ETSEQ, Universitat Rovira i Virgili, Av. Paisos Catalans 26, 43007 Tarragona, Catalunya (Spain)

2014-02-01

Graphical abstract: - Highlights: • Carbonaceous materials were prepared from exhausted sludge materials. • High surface area and good physicochemical properties were achieved. • Utilization of waste sludge materials and mixed anaerobic cultures were used in a continuous anaerobic UPBR system (upflow packed bed biological reactor). • Effective treatment of dye contaminated wastewater in a cheapest and environmental friendly method was demonstrated. - Abstract: This work presents the preliminary study of new carbonaceous materials (CMs) obtained from exhausted sludge, their use in the heterogeneous anaerobic process of biodecolorization of azo dyes and the comparison of their performance with one commercial active carbon. The preparation of carbonaceous materials was conducted through chemical activation and carbonization. Chemical activation was carried out through impregnation of sludge-exhausted materials with ZnCl{sub 2} and the activation by means of carbonization at different temperatures (400, 600 and 800 °C). Their physicochemical and surface characteristics were also investigated. Sludge based carbonaceous (SBC) materials SBC400, SBC600 and SBC800 present values of 13.0, 111.3 and 202.0 m{sup 2}/g of surface area. Biodecolorization levels of 76% were achieved for SBC600 and 86% for SBC800 at space time (τ) of 1.0 min, similar to that obtained with commercial activated carbons in the continuous anaerobic up-flow packed bed reactor (UPBR). The experimental data fit well to the first order kinetic model and equilibrium data are well represented by the Langmuir isotherm model. Carbonaceous materials show high level of biodecolorization even at very short space times. Results indicate that carbonaceous materials prepared from sludge-exhausted materials have outstanding textural properties and significant degradation capacity for treating textile effluents.

Distillation of carbonaceous material

Energy Technology Data Exchange (ETDEWEB)

Ainscow, J W.H.

1936-10-03

To recover hydrocarbon products by distillation of carbonaceous material in a plurality of horizontal zones maintained at different temperatures, a retort has a plurality of superimposed (3) retort chambers, the uppermost being in communication at one end with a hopper and at the other end through coupled junction not shown with one end of the next lower chamber, whose opposite end communicates with lowermost chamber, the other end of which has a sealed discharge passage, tank, and conveyor not shown. Each retort chamber has stirring and conveying means consisting of helical blades (2) attached to radial arms on shaft mounted in water cooled bearings and driven through suitably mounted sprocket wheels and chains not shown. Each retort chamber has a gas dome, with pyrometer tube, and off-take connected to a common main opening into a dust eliminator which in turn connects with a plurality of vertical condensation towers of known construction, maintained at different temperatures by means of steam from a superheater not shown situated in one retort chamber. The retort heating gases pass from the furnace via zig-zag, (three) baffles under and around each retort chamber to a flue not shown.

Carbonaceous material in fine particulate matter (PM10) of urban areas

International Nuclear Information System (INIS)

Brocco, Domenico; Leonardi, Vittorio; Maso; Marco; Prignani, Patrizia

2006-01-01

Total carbon (TC), elemental carbon (EC) and organic carbon (OC) in the fine particulate matter (PM10) were measured in the urban areas of Rome and Marino (Castelli Romani) by means a thermal method with a non-dispersive infrared detector (NDIR). The results showed that carbonaceous material constitutes 30-40% of the total aerosols in Rome and about 20% in Marino [it

The application of a layer of carbonaceous material to a surface

International Nuclear Information System (INIS)

Holland, L.A.

1981-01-01

A method of applying a carbonaceous material to a surface is described. It consists of exposing the surface to an ionised gas atmosphere generated in a gas consisting substantially of carbon and hydrogen, and applying to the surface through capacitive means an electrical potential which changes in sign at time intervals of between 5 x 10 -9 seconds and 10 -6 seconds. (author)

Characterization of baking behaviour of carbonaceous materials by dilatation investigations

Energy Technology Data Exchange (ETDEWEB)

Born, M.; Seichter, A.; Starke, S.

1990-01-01

An increase in volume can be observed in carbonaceous materials during baking which is assumed to be the reason for strains and crack formation. It occurs most pronouncedly within a temperature range from 100 to 200{degree}C. The causes of such phenomena in products pressed at different temperatures are analyzed by means of a gas pressure model and a relaxation model. The factors influencing dilatation are subject to thermal analysis. 15 refs., 13 figs.

Process of treating carbonaceous materials. [400 to 700/sup 0/C, high vacuum

Energy Technology Data Exchange (ETDEWEB)

Parker, O J

1913-11-24

A process is given of treating carbonaceous materials, characterized by the material being submitted simultaneously to a temperature of 400 to 700/sup 0/C, a pressure between 5.0 mm of mercury under atmospheric and a practically perfect vacuum, and by the volatile material able to condense under the vacuum used being condensed practically under the same pressure for the production of a high proportion of condensable products and a superior fuel.

Photolytic process for gasification of carbonaceous material

International Nuclear Information System (INIS)

Zenty, S.

1979-01-01

Process and apparatus are disclosed for converting carbon dioxide to carbon monoxide by subjecting the carbon dioxide to radiation in the presence of carbonaceous material such as coal to form carbon monoxide. The preferred form of radiation is solar energy, and the process is preferably carried out in an atmosphere essentially free of oxygen. The invention also includes subjecting carbon monoxide to radiation to form purified carbon and useful heat energy. The two procedures can be combined into a single process for converting solar or other energy into useful thermal energy with the production of useful products. The reactor apparatus is specifically designed to carry out the radiation-induced conversions. Coal can be desulfurized and its caking characteristics altered by solar radiation in the presence of suitable gases. 3 figures

Organochemical characteristics of carbonaceous materials as indicators of heat recorded on an ancient plate-subduction fault

Science.gov (United States)

Kaneki, S.; Hirono, T.; Mukoyoshi, H.; Sampei, Y.; Ikehara, M.

2016-07-01

Coseismic shear stress and slip distance affect subduction-related earthquake processes. They need to be understood to evaluate the earthquake's mechanism and the tsunami generation potential near trenches. The amount of frictional heat generated depends on the shear stress and slip distance, which are therefore able to be derived from the temperature recorded in the fault. Here we developed a new temperature proxy for carbonaceous materials by performing spectroscopic, thermogravimetric, and organic elemental analyses in conjunction with heating experiments. We found marked anomalies in the infrared and Raman spectra and atomic compositions of carbonaceous materials retrieved from the slip zone of an ancient megasplay fault in the Cretaceous Shimanto accretionary complex, Japan: the infrared spectra show extinction of aliphatic C-H bonding and very weak aromatic C=C bonding, and the Raman spectra show a slightly elevated ratio of disordered band intensity to graphitic band intensity and relatively low H/C and O/C ratios. These correlate well with the spectral and elemental features of host-rock carbonaceous materials after heating to 600°C. Thus, we conclude that the slip zone experienced a temperature of 600°C during a past earthquake event, indicating coseismic slip of 2-9 m, which could have generated a large tsunami if the ruptures propagated to the seafloor.

On thermodynamics of methane+carbonaceous materials adsorption

KAUST Repository

Rahman, Kazi Afzalur

2012-01-01

This study presents the theoretical frameworks for the thermodynamic quantities namely the heat of adsorption, specific heat capacity, entropy, and enthalpy for the adsorption of methane onto various carbonaceous materials. The proposed theoretical frameworks are developed from the rigor of thermodynamic property surfaces of a single component adsorbate-adsorbent system and by incorporating the micropore filling theory approach, where the effect of adsorbed phase volume is considered. The abovementioned thermodynamic properties are quantitatively evaluated from the experimental uptake data for methane adsorption onto activated carbons such as Maxsorb III at temperatures ranging from 120 to 350 K and pressures up to 25 bar. Employing the proposed thermodynamic approaches, this paper shows the thermodynamic maps of the charge and discharge processes of adsorbed natural gas (ANG) storage system for understanding the behaviors of natural gas in ANG vessel. © 2011 Elsevier Ltd. All rights reserved.

Sorption of ionizable and ionic organic compounds to biochar, activated carbon and other carbonaceous materials.

Science.gov (United States)

Kah, Melanie; Sigmund, Gabriel; Xiao, Feng; Hofmann, Thilo

2017-11-01

The sorption of ionic and ionizable organic compounds (IOCs) (e.g., pharmaceuticals and pesticides) on carbonaceous materials plays an important role in governing the fate, transport and bioavailability of IOCs. The paradigms previously established for the sorption of neutral organic compounds do not always apply to IOCs and the importance of accounting for the particular sorption behavior of IOCs is being increasingly recognized. This review presents the current state of knowledge and summarizes the recent advances on the sorption of IOCs to carbonaceous sorbents. A broad range of sorbents were considered to evaluate the possibility to read across between fields of research that are often considered in isolation (e.g., carbon nanotubes, graphene, biochar, and activated carbon). Mechanisms relevant to IOCs sorption on carbonaceous sorbents are discussed and critically evaluated, with special attention being given to emerging sorption mechanisms including low-barrier, charge-assisted hydrogen bonds and cation-π assisted π-π interactions. The key role played by some environmental factors is also discussed, with a particular focus on pH and ionic strength. Overall the review reveals significant advances in our understanding of the interactions between IOCs and carbonaceous sorbents. In addition, knowledge gaps are identified and priorities for future research are suggested. Copyright © 2017 Elsevier Ltd. All rights reserved.

Production of gaseous or vaporous fuels from solid carbonaceous materials

Energy Technology Data Exchange (ETDEWEB)

1951-05-16

A process for the production of gaseous or vaporous fuels from solid carbonaceous materials consists of subjecting the materials in separate zones to at least three successive thermal treatments at least two of which are carried out at different temperature levels. The materials being maintained in zones in the form of beds of finely divided particles fluidized by the passage of gases or vapors upwardly there-through, and recovering product vapors or gases overhead. The total hot gaseous or vaporous effluent and entrained solids from one of the zones is passed directly without separation to another of the zones situated closely adjacent to and vertically above the first named zone in the same vessel, and the heat required in at least one of the thermal treatment zones is supplied at least in part as the sensible heat of residual solids transferred from a thermal treatment zone operated at a higher temperature.

Nitrogen-Doped Carbonaceous Materials for Removal of Phenol from Aqueous Solutions

Directory of Open Access Journals (Sweden)

Magdalena Hofman

2012-01-01

Full Text Available Carbonaceous material (brown coal modified by pyrolysis, activation, and enrichment in nitrogen, with two different factor reagents, have been used as adsorbent of phenol from liquid phase. Changes in the phenol content in the test solutions were monitored after subsequent intervals of adsorption with selected adsorbents prepared from organic materials. Significant effect of nitrogen present in the adsorbent material on its adsorption capacity was noted. Sorption capacity of these selected materials was found to depend on the time of use, their surface area, and pore distribution. A conformation to the most well-known adsorption isotherm models, Langmuir, and Freundlich ones, confirms the formation of mono- and heterolayer solute (phenol coverage on the surface of the adsorbent applied herein. The materials proposed as adsorbents of the aqueous solution contaminants were proved effective, which means that the waste materials considered are promising activated carbon precursors for liquid phase adsorbents for the environmental protection.

Electron spin resonance and its application to heat treated carbonaceous materials

International Nuclear Information System (INIS)

Emmerich, Francisco Guilherme

1993-01-01

This work presents the basic characteristics of the electron spin resonance technique, also called paramagnetic resonance, being discussed its application to heat treated carbonaceous materials. In the low heat treatment temperature (HTT) range (below 700 deg C) the organic free radical are the predominant unpaired spin center, which play a key role in the process of carbonization and meso phase formation. At higher temperatures, it is possible to make correlations between the low H T T range and the high HTT range (above 130 deg C), where the predominant unpaired spin center are the free charge carriers (free electrons) of the graphite like crystallites of the material, which are formed by the carbonization process. (author)

Impact of carbonaceous materials in soil on the transport of soil-bound PAHs during rainfall-runoff events

International Nuclear Information System (INIS)

Luo, Xiaolin; Zheng, Yi; Wu, Bin; Lin, Zhongrong; Han, Feng; Zhang, Wei; Wang, Xuejun

2013-01-01

Polycyclic Aromatic Hydrocarbons (PAHs) transported from contaminated soils by surface runoff pose significant risk for aquatic ecosystems. Based on a rainfall-runoff simulation experiment, this study investigated the impact of carbonaceous materials (CMs) in soil, identified by organic petrology analysis, on the transport of soil-bound PAHs under rainfall conditions. The hypothesis that composition of soil organic matter significantly impacts the enrichment and transport of PAHs was proved. CMs in soil, varying significantly in content, mobility and adsorption capacity, act differently on the transport of PAHs. Anthropogenic CMs like black carbon (BC) largely control the transport, as PAHs may be preferentially attached to them. Eventually, this study led to a rethink of the traditional enrichment theory. An important implication is that CMs in soil have to be explicitly considered to appropriately model the nonpoint source pollution of PAHs (possibly other hydrophobic chemicals as well) and assess its environmental risk. -- Highlights: •Composition of SOM significantly impacts the enrichment and transport of PAHs. •Anthropogenic carbonaceous materials in soil largely control the transport of PAHs. •The classic enrichment theory is invalid if anthropogenic CMs are abundant in the soil. •Organic petrology analysis introduced to study the fate and transport of PAHs. -- Anthropogenic carbonaceous materials in soil, especially black carbon, largely control the transport of soil-bound PAHs during rainfall-runoff events

Primordial Molecular Cloud Material in Metal-Rich Carbonaceous Chondrites

Science.gov (United States)

Taylor, G. J.

2016-03-01

The menagerie of objects that make up our Solar System reflects the composition of the huge molecular cloud in which the Sun formed, a late addition of short-lived isotopes from an exploding supernova or stellar winds from a neighboring massive star, heating and/or alteration by water in growing planetesimals that modified and segregated the primordial components, and mixing throughout the Solar System. Outer Solar System objects, such as comets, have always been cold, hence minimizing the changes experienced by more processed objects. They are thought to preserve information about the molecular cloud. Elishevah Van Kooten (Natural History Museum of Denmark and the University of Copenhagen) and co-authors in Denmark and at the University of Hawai'i, measured the isotopic compositions of magnesium and chromium in metal-rich carbonaceous chondrites. They found that the meteorites preserve an isotopic signature of primordial molecular cloud materials, providing a potentially detailed record of the molecular cloud's composition and of materials that formed in the outer Solar System.

Isotopic evidence for primordial molecular cloud material in metal-rich carbonaceous chondrites

DEFF Research Database (Denmark)

van Kooten, Elishevah M. M. E.; Wielandt, Daniel Kim Peel; Schiller, Martin

2016-01-01

product of (26)Al. This correlation is interpreted as reflecting progressive thermal processing of in-falling (26)Al-rich molecular cloud material in the inner Solar System. The thermally unprocessed molecular cloud matter reflecting the nucleosynthetic makeup of the molecular cloud before the last......)Mg*-depleted and (54)Cr-enriched component. This composition is consistent with that expected for thermally unprocessed primordial molecular cloud material before its pollution by stellar-derived (26)Al. The (26)Mg* and (54)Cr compositions of bulk metal-rich chondrites require significant amounts (25......-50%) of primordial molecular cloud matter in their precursor material. Given that such high fractions of primordial molecular cloud material are expected to survive only in the outer Solar System, we infer that, similarly to cometary bodies, metal-rich carbonaceous chondrites are samples of planetesimals...

CO₂ Separation and Capture Properties of Porous Carbonaceous Materials from Leather Residues.

Science.gov (United States)

Bermúdez, José M; Dominguez, Pablo Haro; Arenillas, Ana; Cot, Jaume; Weber, Jens; Luque, Rafael

2013-10-18

Carbonaceous porous materials derived from leather skin residues have been found to have excellent CO₂ adsorption properties, with interestingly high gas selectivities for CO₂ (α > 200 at a gas composition of 15% CO₂/85% N₂, 273K, 1 bar) and capacities (>2 mmol·g -1 at 273 K). Both CO₂ isotherms and the high heat of adsorption pointed to the presence of strong binding sites for CO₂ which may be correlated with both: N content in the leather residues and ultrasmall pore sizes.

Molybdenum isotopic evidence for the origin of chondrules and a distinct genetic heritage of carbonaceous and non-carbonaceous meteorites

Science.gov (United States)

Budde, Gerrit; Burkhardt, Christoph; Brennecka, Gregory A.; Fischer-Gödde, Mario; Kruijer, Thomas S.; Kleine, Thorsten

2016-11-01

Nucleosynthetic isotope anomalies are powerful tracers to determine the provenance of meteorites and their components, and to identify genetic links between these materials. Here we show that chondrules and matrix separated from the Allende CV3 chondrite have complementary nucleosynthetic Mo isotope anomalies. These anomalies result from the enrichment of a presolar carrier enriched in s-process Mo into the matrix, and the corresponding depletion of this carrier in the chondrules. This carrier most likely is a metal and so the uneven distribution of presolar material probably results from metal-silicate fractionation during chondrule formation. The Mo isotope anomalies correlate with those reported for W isotopes on the same samples in an earlier study, suggesting that the isotope variations for both Mo and W are caused by the heterogeneous distribution of the same carrier. The isotopic complementary of chondrules and matrix indicates that both components are genetically linked and formed together from one common reservoir of solar nebula dust. As such, the isotopic data require that most chondrules formed in the solar nebula and are not a product of protoplanetary impacts. Allende chondrules and matrix together with bulk carbonaceous chondrites and some iron meteorites (groups IID, IIIF, and IVB) show uniform excesses in 92Mo, 95Mo, and 97Mo that result from the addition of supernova material to the solar nebula region in which these carbonaceous meteorites formed. Non-carbonaceous meteorites (enstatite and ordinary chondrites as well as most iron meteorites) do not contain this material, demonstrating that two distinct Mo isotope reservoirs co-existed in the early solar nebula that remained spatially separated for several million years. This separation was most likely achieved through the formation of the gas giants, which cleared the disk between the inner and outer solar system regions parental to the non-carbonaceous and carbonaceous meteorites. The Mo isotope

Spatial and spectral resolution of carbonaceous material from hematite (α-Fe2O3) using multivariate curve resolution-alternating least squares (MCR-ALS) with Raman microspectroscopic mapping: implications for the search for life on Mars.

Science.gov (United States)

Smith, Joseph P; Smith, Frank C; Booksh, Karl S

2017-08-21

The search for evidence of extant or past life on Mars is a primary objective of both the upcoming Mars 2020 rover (NASA) and ExoMars 2020 rover (ESA/Roscosmos) missions. This search will involve the detection and identification of organic molecules and/or carbonaceous material within the Martian surface environment. For the first time on a mission to Mars, the scientific payload for each rover will include a Raman spectrometer, an instrument well-suited for this search. Hematite (α-Fe 2 O 3 ) is a widespread mineral on the Martian surface. The 2LO Raman band of hematite and the Raman D-band of carbonaceous material show spectral overlap, leading to the potential misidentification of hematite as carbonaceous material. Here we report the ability to spatially and spectrally differentiate carbonaceous material from hematite using multivariate curve resolution-alternating least squares (MCR-ALS) applied to Raman microspectroscopic mapping under both 532 nm and 785 nm excitation. For this study, a sample comprised of hematite, carbonaceous material, and substrate-adhesive epoxy in spatially distinct domains was constructed. Principal component analysis (PCA) reveals that both 532 nm and 785 nm excitation produce representative three-phase systems of hematite, carbonaceous material, and substrate-adhesive epoxy in the analyzed sample. MCR-ALS with Raman microspectroscopic mapping using both 532 nm and 785 nm excitation was able to resolve hematite, carbonaceous material, and substrate-adhesive epoxy by generating spatially-resolved chemical maps and corresponding Raman spectra of these spatially distinct chemical species. Moreover, MCR-ALS applied to the combinatorial data sets of 532 nm and 785 nm excitation, which contain hematite and carbonaceous material within the same locations, was able to resolve hematite, carbonaceous material, and substrate-adhesive epoxy. Using multivariate analysis with Raman microspectroscopic mapping, 785 nm excitation more effectively

Modelling decreased food chain accumulation of HOCs due to strong sorption to carbonaceous materials and metabolic transformation

NARCIS (Netherlands)

Moermond, C.T.A.; Traas, T.P.; Roessink, I.; Veltman, K.; Hendriks, A.J.; Koelmans, A.A.

2007-01-01

The predictive power of bioaccumulation models may be limited when they do not account for strong sorption of organic contaminants to carbonaceous materials (CM) such as black carbon, and when they do not include metabolic transformation. We tested a food web accumulation model, including sorption

Removal of blue indigo and cadmium present in aqueous solutions using a modified zeolitic material and an activated carbonaceous material; Remocion de azul indigo y cadmio presentes en soluciones acuosas empleando un material zeolitico modificado y un material carbonoso activado

Energy Technology Data Exchange (ETDEWEB)

Gutierrez S, E. E.

2011-07-01

In the last years the use of water has been increased substantially, it has been also altered its quality as a result of human activities such as mining, industrial activities and others. Water pollution caused by dyes and heavy metals has adverse effects on the environment, since both pollutants are very persisten even after conventional treatments. Denim blue and cadmium are not biodegradable. There is a growing interest in finding new, efficient and low cost alternative materials to remove such pollutants from the aqueous medium. The purpose of this work was to evaluate a modified zeolitic tuff and an activated carbonaceous material obtained from the pyrolysis of sewage sludge for the removal of denim blue and cadmium. The zeolitic material was modified with Na{sup +} and Fe{sup 3+} solutions to improve its sorption properties for the removal of cadmium and denim blue, respectively. Carbonaceous material was treated with 10% HCl solution to remove ashes. Both materials were characterized by scanning electron microscopy and elemental analysis (EDS), specific surface areas (Bet), thermogravimetric analysis, infrared spectroscopy and X-ray diffraction. Simultaneously, the denim blue dye was characterized by infrared spectroscopy and its pKa value was determined, these data allowed the determination of its chemical properties and its acid-base behavior in solution. In the content of this work the term indigo blue was changed by denim blue, as it corresponds to the commercial name of the dye. To assess the sorption capacity of sorbents, the sorption kinetics and sorption isotherms in batch system were determined; the results were fitted to mathematical models such as the pseudo-first order, pseudo second order and second order to describe the sorption kinetics and the Langmuir, Freundlich and Langmuir-Freundlich isotherms to describe sorption processes. The results show that the most efficient material to remove denim blue from aqueous solutions is the carbonaceous

The carbonaceous sorbent based on the secondary silica-containing material from oil extraction industry

Science.gov (United States)

Starostina, I. V.; Stolyarov, D. V.; Anichina, Ya N.; Porozhnyuk, E. V.

2018-01-01

The object of research in this work is the silica-containing waste of oil extraction industry - the waste kieselghur (diatomite) sludge from precoat filtering units, used for the purification of vegetable oils from organic impurities. As a result of the thermal modification of the sludge, which contains up to 70% of organic impurities, a finely-dispersed low-porous carbonaceous mineral sorption material is formed. The modification of the sludge particles surface causes the substantial alteration of its physical, chemical, adsorption and structural properties - the organic matter is charred, the particle size is reduced, and on the surface of diatomite particles a carbon layer is formed, which deposits in macropores and partially occludes them. The amount of mesopores is increased, along with the specific surface of the obtained product. The optimal temperature of sludge modification is 500°C. The synthesized carbonaceous material can be used as an adsorbing agent for the purification of wastewater from heavy metal ions. The sorption capacity of Cu2+ ions amounted to 14.2 mg·g-1 and for Ni2+ ions - 17.0 mg·g-1. The obtained values exceed the sorption capacity values of the initial kieselghur, used as a filtering charge, for the researched metal ions.

Baking process of thin plate carbonaceous compact

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Yoshio; Shimada, Toyokazu

1987-06-27

As a production process of a thin plate carbonaceous compact for separator of phosphoric acid fuel cell, there is a process to knead carbonaceous powder and thermosetting resin solution, to form and harden the kneaded material and then to bake, carbonize and graphitize it. However in this baking and carbonization treatment, many thin plate compacts are set in a compiled manner within a heating furnace and receive a heat treatment from their circumference. Since the above compacts to be heated tend generally to be heated from their peripheries, their baked conditions are not homogeneous easily causing the formation of cracks, etc.. As a process to heat and bake homogeneously by removing the above problematical points, this invention offers a process to set in a heating furnace a laminate consisting of the lamination of thin plate carbonaceous compacts and the heat resistant soaking plates which hold the upper and lower ends of the above lamination, to fill the upper and under peripheries of the laminate above with high heat conductive packing material and its side periphery with low heat conductive packing material respectively and to heat and sinter it. In addition, the invention specifies the high and low heat conductive packing materials respectively. (1 fig, 2 tabs)

Ultraviolet spectral reflectance of carbonaceous materials

Science.gov (United States)

Applin, Daniel M.; Izawa, Matthew R. M.; Cloutis, Edward A.; Gillis-Davis, Jeffrey J.; Pitman, Karly M.; Roush, Ted L.; Hendrix, Amanda R.; Lucey, Paul G.

2018-06-01

A number of planetary spacecraft missions have carried instruments with sensors covering the ultraviolet (UV) wavelength range. However, there exists a general lack of relevant UV reflectance laboratory data to compare against these planetary surface remote sensing observations in order to make confident material identifications. To address this need, we have systematically analyzed reflectance spectra of carbonaceous materials in the 200-500 nm spectral range, and found spectral-compositional-structural relationships that suggest this wavelength region could distinguish between otherwise difficult-to-identify carbon phases. In particular (and by analogy with the infrared spectral region), large changes over short wavelength intervals in the refractive indices associated with the trigonal sp2π-π* transition of carbon can lead to Fresnel peaks and Christiansen-like features in reflectance. Previous studies extending to shorter wavelengths also show that anomalous dispersion caused by the σ-σ* transition associated with both the trigonal sp2 and tetrahedral sp3 sites causes these features below λ = 200 nm. The peak wavelength positions and shapes of π-π* and σ-σ* features contain information on sp3/sp2, structure, crystallinity, and powder grain size. A brief comparison with existing observational data indicates that the carbon fraction of the surface of Mercury is likely amorphous and submicroscopic, as is that on the surface of the martian satellites Phobos and Deimos, and possibly comet 67P/Churyumov-Gerasimenko, while further coordinated observations and laboratory experiments should refine these feature assignments and compositional hypotheses. The new laboratory diffuse reflectance data reported here provide an important new resource for interpreting UV reflectance measurements from planetary surfaces throughout the solar system, and confirm that the UV can be rich in important spectral information.

Analyses and characterization of fossil carbonaceous materials for silicon production

Energy Technology Data Exchange (ETDEWEB)

Myrvaagnes, Viktor

2008-01-15

Production of high silicon alloys is carried out in submerged arc furnaces by reduction of silicon bearing oxides (typically quartz) with carbon materials. Carbonaceous materials like coal, coke, charcoal and woodchips are commonly used as reduction materials in the process. Primarily based on historical prices of charcoal compared to fossil reduction materials, the Norwegian Ferroalloy Industry has mostly been using coal and coke (char) as the source of carbon. From a process point of view, the most important role of the carbonaceous material is to react with SiO gas to produce SiC. The ability of the reduction materials to react with SiO gas can be measured and the value is recognized as the reactivity of the carbon source. Reactivity is one of the most important parameters in the smelting process and is commonly acknowledged to strongly affect both productivity and specific energy consumption. The main objectives of this work has been to establish methods to characterize the material properties of fossil carbonaceous reduction materials used in the silicon process and to evaluated how these properties affect the reactivity towards SiO gas. In order to accomplish these objectives, three run of mine (ROM) single seam coals which are particularly well suited for ferroalloy production were selected. Two Carboniferous coals from USA (Blue Gem) and Poland (Staszic) with similar rank, but significantly different composition as well as a Permian coal from Australia (Peak Downs) have been characterized by chemical- and petrographical methods. Blue Gem is a homogeneous coal, low in mineral inclusions and macerals of the inertinite group and determined to have a random vitrinite reflectance of 0.71 %. Staszic has a similar reflectance of vitrinite (0.72 %), but is determined to be a very inhomogeneous coal with both inertinite macerals and minerals embedded in the vitrinite matrix. Peak Downs has a random reflectance of vitrinite of 1.32 % and is hence the coal sample of

CO2 Separation and Capture Properties of Porous Carbonaceous Materials from Leather Residues

Directory of Open Access Journals (Sweden)

Ana Arenillas

2013-10-01

Full Text Available Carbonaceous porous materials derived from leather skin residues have been found to have excellent CO2 adsorption properties, with interestingly high gas selectivities for CO2 (α > 200 at a gas composition of 15% CO2/85% N2, 273K, 1 bar and capacities (>2 mmol·g−1 at 273 K. Both CO2 isotherms and the high heat of adsorption pointed to the presence of strong binding sites for CO2 which may be correlated with both: N content in the leather residues and ultrasmall pore sizes.

CO2 Separation and Capture Properties of Porous Carbonaceous Materials from Leather Residues

Science.gov (United States)

Bermúdez, José M.; Dominguez, Pablo Haro; Arenillas, Ana; Cot, Jaume; Weber, Jens; Luque, Rafael

2013-01-01

Carbonaceous porous materials derived from leather skin residues have been found to have excellent CO2 adsorption properties, with interestingly high gas selectivities for CO2 (α > 200 at a gas composition of 15% CO2/85% N2, 273K, 1 bar) and capacities (>2 mmol·g−1 at 273 K). Both CO2 isotherms and the high heat of adsorption pointed to the presence of strong binding sites for CO2 which may be correlated with both: N content in the leather residues and ultrasmall pore sizes. PMID:28788352

Successive self-propagating sintering process using carbonaceous materials: A novel low-cost remediation approach for dioxin-contaminated solids

Energy Technology Data Exchange (ETDEWEB)

Zhao, Long, E-mail: zhaolong@craes.org.cn [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Dayangfang 8, Beijing 100012 (China); Hou, Hong, E-mail: houhong@craes.org.cn [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Dayangfang 8, Beijing 100012 (China); Zhu, Tengfei; Li, Fasheng [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Dayangfang 8, Beijing 100012 (China); Terada, Akihiko; Hosomi, Masaaki [Department of Chemical Engineering, Faculty of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588 (Japan)

2015-12-15

Highlights: • A SSPSP using carbonaceous materials for removing dioxin pollutants was developed. • Removal and degradation efficiencies of DL-PCBs were higher than those of PCDD/Fs. • Compositions of PCDD/Fs were dependent on the available precursors in raw materials. • Dechlorination of O{sub 8}CDD and formation pathways of PCDFs were deduced. • Dioxin levels in the effluent gas complied with the International emission limit. - Abstract: The disposal of dioxin-contaminated solids was studied using a novel successive self-propagating sintering process (SSPSP) incorporating a carbonaceous material. Among the five types of carbonaceous materials investigated, Charcoal B displayed optimum adsorbent properties and was selected as the best thermal source in the current remediation approach based on economical efficiency aspects. The feasibility of this proposed approach, removal efficiencies, and congener compositions of dioxins were examined using two types of dioxin-contaminated solids (Fugan sediment and Toyo soil) that displayed different characteristics including the initial concentrations of dioxins. The removal efficiencies of DL-PCBs (“dioxin-like” polychlorinated biphenyls) were higher than those of PCDD/Fs (polychlorinated dibenzo-p-dioxins/dibenzofurans), achieving 99.9 and 92% removal in the Fugan sediment and Toyo soil, respectively. In contrast, the degradation efficiencies of DL-PCBs were lower (i.e., 89.3 and 88.8%, respectively). The initial concentrations of dioxins, available precursors, and properties of the solids strongly influenced the congener compositions and removal efficiencies of dioxins. Furthermore, the dechlorination reaction pathways of high-chlorinated PCDDs and potential regeneration pathways of PCDFs from PCBs were deduced using isotope labeling. The proposed novel low-cost remediation approach for the removal of dioxins from solids is a highly efficient and environmentally sound treatment technology.

Successive self-propagating sintering process using carbonaceous materials: A novel low-cost remediation approach for dioxin-contaminated solids

International Nuclear Information System (INIS)

Zhao, Long; Hou, Hong; Zhu, Tengfei; Li, Fasheng; Terada, Akihiko; Hosomi, Masaaki

2015-01-01

Highlights: • A SSPSP using carbonaceous materials for removing dioxin pollutants was developed. • Removal and degradation efficiencies of DL-PCBs were higher than those of PCDD/Fs. • Compositions of PCDD/Fs were dependent on the available precursors in raw materials. • Dechlorination of O_8CDD and formation pathways of PCDFs were deduced. • Dioxin levels in the effluent gas complied with the International emission limit. - Abstract: The disposal of dioxin-contaminated solids was studied using a novel successive self-propagating sintering process (SSPSP) incorporating a carbonaceous material. Among the five types of carbonaceous materials investigated, Charcoal B displayed optimum adsorbent properties and was selected as the best thermal source in the current remediation approach based on economical efficiency aspects. The feasibility of this proposed approach, removal efficiencies, and congener compositions of dioxins were examined using two types of dioxin-contaminated solids (Fugan sediment and Toyo soil) that displayed different characteristics including the initial concentrations of dioxins. The removal efficiencies of DL-PCBs (“dioxin-like” polychlorinated biphenyls) were higher than those of PCDD/Fs (polychlorinated dibenzo-p-dioxins/dibenzofurans), achieving 99.9 and 92% removal in the Fugan sediment and Toyo soil, respectively. In contrast, the degradation efficiencies of DL-PCBs were lower (i.e., 89.3 and 88.8%, respectively). The initial concentrations of dioxins, available precursors, and properties of the solids strongly influenced the congener compositions and removal efficiencies of dioxins. Furthermore, the dechlorination reaction pathways of high-chlorinated PCDDs and potential regeneration pathways of PCDFs from PCBs were deduced using isotope labeling. The proposed novel low-cost remediation approach for the removal of dioxins from solids is a highly efficient and environmentally sound treatment technology.

Low-temperature catalytic conversion of carbonaceous materials

Directory of Open Access Journals (Sweden)

Tabakaev Roman B.

2015-01-01

Full Text Available Laws of the rate of carbon conversion in steam atmosphere at a temperature in modes of the catalytic low-temperature treatment of peat, brown coal, semi-coke from peat and brown coal are obtained by experiments. Increasing of the rate of carbon conversion in temperature range up to 500 °C is achieved by using of catalysts. The possibility of using results is associated with the burners, a working zone of which is porous filling from carbonaceous particles.

Nebula Scale Mixing Between Non-Carbonaceous and Carbonaceous Chondrite Reservoirs: Testing the Grand Tack Model with Almahata Sitta Stones

Science.gov (United States)

Yin, Q.-Z.; Sanborn, M. E.; Goodrich, C. A.; Zolensky, M.; Fioretti, A. M.; Shaddad, M.; Kohl, I. E.; Young, E. D.

2018-01-01

There is an increasing number of Cr-O-Ti isotope studies that show that solar system materials are divided into two main populations, one carbonaceous chondrite (CC)-like and the other is non-carbonaceous (NCC)-like, with minimal mixing between them attributed to a gap opened in the propoplanetary disk due to Jupiter's formation. The Grand Tack model suggests that there should be a particular time in the disk history when this gap is breached and ensuring a subsequent large-scale mixing between S- and C-type asteroids (inner solar system and outer solar system materials), an idea supported by our recent work on chondrule (Delta)17O-(epsilon)54Cr isotope systematics.

Laboratory Experiments on the Low-temperature Formation of Carbonaceous Grains in the ISM

Science.gov (United States)

Fulvio, Daniele; Góbi, Sándor; Jäger, Cornelia; Kereszturi, Ákos; Henning, Thomas

2017-11-01

The life cycle of cosmic dust grains is far from being understood and the origin and evolution of interstellar medium (ISM) grains is still under debate. In the ISM, the cosmic dust destruction rate is faster than the production rate by stellar sources. However, observations of ISM refractory matter suggest that to maintain a steady amount of cosmic grains, some supplementary production mechanism takes place. In this context, we aimed to study possible reformation mechanisms of cosmic grains taking place at low temperature directly in the ISM. The low-temperature condensation of carbonaceous materials has been investigated in experiments mimicking the ISM conditions. Gas-phase carbonaceous precursors created by laser ablation of graphite were forced to accrete on cold substrates (T ≈ 10 K) representing surviving dust grains. The growing and evolution of the condensing carbonaceous precursors have been monitored by MIR and UV spectroscopy under a number of experimental scenarios. For the first time, the possibility to form ISM carbonaceous grains in situ is demonstrated. The condensation process is governed by carbon chains that first condense into small carbon clusters and finally into more stable carbonaceous materials, of which structural characteristics are comparable to the material formed in gas-phase condensation experiments at very high temperature. We also show that the so-formed fullerene-like carbonaceous material is transformed into a more ordered material under VUV processing. The cold condensation mechanisms discussed here can give fundamental clues to fully understand the balance between the timescale for dust injection, destruction, and reformation in the ISM.

Explosive Characteristics of Carbonaceous Nanoparticles

Science.gov (United States)

Turkevich, Leonid; Fernback, Joseph; Dastidar, Ashok

2013-03-01

Explosion testing has been performed on 20 codes of carbonaceous particles. These include SWCNTs (single-walled carbon nanotubes), MWCNTs (multi-walled carbon nanotubes), CNFs (carbon nanofibers), graphene, diamond, fullerene, carbon blacks and graphites. Explosion screening was performed in a 20 L explosion chamber (ASTM E1226-10 protocol), at a (dilute) concentration of 500 g/m3, using a 5 kJ ignition source. Time traces of overpressure were recorded. Samples exhibited overpressures of 5-7 bar, and deflagration index KSt = V1/3 (dp/pt)max ~ 10 - 80 bar-m/s, which places these materials in European Dust Explosion Class St-1 (similar to cotton and wood dust). There was minimal variation between these different materials. The explosive characteristics of these carbonaceous powders are uncorrelated with particle size (BET specific surface area). Additional tests were performed on selected materials to identify minimum explosive concentration [MEC]. These materials exhibit MEC ~ 101 -102 g/m3 (lower than the MEC for coals). The concentration scans confirm that the earlier screening was performed under fuel-rich conditions (i.e. the maximum over-pressure and deflagration index exceed the screening values); e.g. the true fullerene KSt ~ 200 bar-m/s, placing it borderline St-1/St-2. Work supported through the NIOSH Nanotechnology Research Center (NTRC)

Destructive hydrogenation of carbonaceous materials, etc

Energy Technology Data Exchange (ETDEWEB)

1938-02-15

A process is described for the destructive hydrogenation continuously of solid and infusible carbonaceous substances, consisting of heating the charge to the same temperature as the added hydrogen, under a pressure essentially equal to that of the reaction, from the first to at least 300/sup 0/C, but not more than 440/sup 0/C, while passing the heated charge through a zone the contents of which are equal to about 20 per cent to 40 per cent of that of the reaction space, maintaining the charge for a certain time at the temperature without sensible change in the pressure, then reheating the charge to at least the temperature to prime the reaction and finally to introduce the charge into the reaction space.

Heavy-ion irradiation induced diamond formation in carbonaceous materials

International Nuclear Information System (INIS)

Daulton, T. L.

1999-01-01

The basic mechanisms of metastable phase formation produced under highly non-equilibrium thermodynamic conditions within high-energy particle tracks are investigated. In particular, the possible formation of diamond by heavy-ion irradiation of graphite at ambient temperature is examined. This work was motivated, in part, by earlier studies which discovered nanometer-grain polycrystalline diamond aggregates of submicron-size in uranium-rich carbonaceous mineral assemblages of Precambrian age. It was proposed that the radioactive decay of uranium formed diamond in the fission particle tracks produced in the carbonaceous minerals. To test the hypothesis that nanodiamonds can form by ion irradiation, fine-grain polycrystalline graphite sheets were irradiated with 400 MeV Kr ions. The ion irradiated graphite (and unirradiated graphite control) were then subjected to acid dissolution treatments to remove the graphite and isolate any diamonds that were produced. The acid residues were then characterized by analytical and high-resolution transmission electron microscopy. The acid residues of the ion-irradiated graphite were found to contain ppm concentrations of nanodiamonds, suggesting that ion irradiation of bulk graphite at ambient temperature can produce diamond

Liquefaction of solid carbonaceous material with catalyst recycle

Science.gov (United States)

Gupta, Avinash; Greene, Marvin I.

1992-01-01

In the two stage liquefaction of a carbonaceous solid such as coal wherein coal is liquefied in a first stage in the presence of a liquefaction solvent and the first stage effluent is hydrogenated in the presence of a supported hydrogenation catalyst in a second stage, catalyst which has been previously employed in the second stage and comminuted to a particle size distribution equivalent to 100% passing through U.S. 100 Mesh, is passed to the first stage to improve the overall operation.

Acid functionalized, highly dispersed carbonaceous spheres: an effective solid acid for hydrolysis of polysaccharides

International Nuclear Information System (INIS)

Jiang Yijun; Li Xiutao; Cao Quan; Mu Xindong

2011-01-01

Highly dispersed carbonaceous spheres with sulfonic acid groups were successfully prepared from glucose by hydrothermal method. Transmission electron microscopy (TEM) showed the as-synthesized carbonaceous materials were uniform, spherical in shape with an average diameter of about 450 nm. Fourier transform infrared (FT-IR) proved that –SO 3 H, –COOH, OH groups were grafted on the surface of the carbonaceous spheres during the sulfonation. Interestingly, the functionalized carbonaceous spheres exhibited high dispersibility in the polar solvent due to the hydrophilic groups on the surface. The mechanism of the formation for the carbonaceous spheres was also discussed based on the analysis of structure and composition. At last, the functionalized carbonaceous spheres were employed as solid acid to hydrolyze starch and cellulose. By comparison, the as-synthesized catalyst showed considerable high yield of glucose.

Acid functionalized, highly dispersed carbonaceous spheres: an effective solid acid for hydrolysis of polysaccharides

Science.gov (United States)

Jiang, Yijun; Li, Xiutao; Cao, Quan; Mu, Xindong

2011-02-01

Highly dispersed carbonaceous spheres with sulfonic acid groups were successfully prepared from glucose by hydrothermal method. Transmission electron microscopy (TEM) showed the as-synthesized carbonaceous materials were uniform, spherical in shape with an average diameter of about 450 nm. Fourier transform infrared (FT-IR) proved that -SO3H, -COOH, OH groups were grafted on the surface of the carbonaceous spheres during the sulfonation. Interestingly, the functionalized carbonaceous spheres exhibited high dispersibility in the polar solvent due to the hydrophilic groups on the surface. The mechanism of the formation for the carbonaceous spheres was also discussed based on the analysis of structure and composition. At last, the functionalized carbonaceous spheres were employed as solid acid to hydrolyze starch and cellulose. By comparison, the as-synthesized catalyst showed considerable high yield of glucose.

Process for the liquefaction of solid carbonaceous materials wherein nitrogen is separated from hydrogen via ammonia synthesis

Science.gov (United States)

Stetka, Steven S.; Nazario, Francisco N.

1982-01-01

In a process for the liquefaction of solid carbonaceous materials wherein bottoms residues are upgraded with a process wherein air is employed, the improvement wherein nitrogen buildup in the system is avoided by ammonia synthesis. In a preferred embodiment hydrogen from other portions of the liquefaction process will be combined with hydrogen produced as a result of the bottoms upgrading to increase the H.sub.2 :N.sub.2 ratio in the ammonia reactor.

The Distinct Genetics of Carbonaceous and Non-Carbonaceous Meteorites Inferred from Molybdenum Isotopes

Science.gov (United States)

Budde, G.; Burkhardt, C.; Kleine, T.

2017-07-01

Mo isotope systematics manifest a fundamental dichotomy in the genetic heritage of carbonaceous and non-carbonaceous meteorites. We discuss its implications in light of the most recent literature data and new isotope data for primitive achondrites.

Comparison of Ablation Predictions for Carbonaceous Materials Using CEA and JANAF-Based Species Thermodynamics

Science.gov (United States)

Milos, Frank S.

2011-01-01

In most previous work at NASA Ames Research Center, ablation predictions for carbonaceous materials were obtained using a species thermodynamics database developed by Aerotherm Corporation. This database is derived mostly from the JANAF thermochemical tables. However, the CEA thermodynamics database, also used by NASA, is considered more up to date. In this work, the FIAT code was modified to use CEA-based curve fits for species thermodynamics, then analyses using both the JANAF and CEA thermodynamics were performed for carbon and carbon phenolic materials over a range of test conditions. The ablation predictions are comparable at lower heat fluxes where the dominant mechanism is carbon oxidation. However, the predictions begin to diverge in the sublimation regime, with the CEA model predicting lower recession. The disagreement is more significant for carbon phenolic than for carbon, and this difference is attributed to hydrocarbon species that may contribute to the ablation rate.

Carbon Paste Electrodes Made from Different Carbonaceous Materials: Application in the Study of Antioxidants

Science.gov (United States)

Apetrei, Constantin; Apetrei, Irina Mirela; De Saja, Jose Antonio; Rodriguez-Mendez, Maria Luz

2011-01-01

This work describes the sensing properties of carbon paste electrodes (CPEs) prepared from three different types of carbonaceous materials: graphite, carbon microspheres and carbon nanotubes. The electrochemical responses towards antioxidants including vanillic acid, catechol, gallic acid, l-ascorbic acid and l-glutathione have been analyzed and compared. It has been demonstrated that the electrodes based on carbon microspheres show the best performances in terms of kinetics and stability, whereas G-CPEs presented the smallest detection limit for all the antioxidants analyzed. An array of electrodes has been constructed using the three types of electrodes. As demonstrated by means of Principal Component Analysis, the system is able to discriminate among antioxidants as a function of their chemical structure and reactivity. PMID:22319354

Origin and abundance of water in carbonaceous asteroids

Science.gov (United States)

Marrocchi, Yves; Bekaert, David V.; Piani, Laurette

2018-01-01

The origin and abundance of water accreted by carbonaceous asteroids remains underconstrained, but would provide important information on the dynamic of the protoplanetary disk. Here we report the in situ oxygen isotopic compositions of aqueously formed fayalite grains in the Kaba and Mokoia CV chondrites. CV chondrite bulk, matrix and fayalite O-isotopic compositions define the mass-independent continuous trend (δ17O = 0.84 ± 0.03 × δ18O - 4.25 ± 0.1), which shows that the main process controlling the O-isotopic composition of the CV chondrite parent body is related to isotopic exchange between 16O-rich anhydrous silicates and 17O- and 18O-rich fluid. Similar isotopic behaviors observed in CM, CR and CO chondrites demonstrate the ubiquitous nature of O-isotopic exchange as the main physical process in establishing the O-isotopic features of carbonaceous chondrites, regardless of their alteration degree. Based on these results, we developed a new approach to estimate the abundance of water accreted by carbonaceous chondrites (quantified by the water/rock ratio) with CM (0.3-0.4) ≥ CR (0.1-0.4) ≥ CV (0.1-0.2) > CO (0.01-0.10). The low water/rock ratios and the O-isotopic characteristics of secondary minerals in carbonaceous chondrites indicate they (i) formed in the main asteroid belt and (ii) accreted a locally derived (inner Solar System) water formed near the snowline by condensation from the gas phase. Such results imply low influx of D- and 17O- and 18O-rich water ice grains from the outer part of the Solar System. The latter is likely due to the presence of a Jupiter-induced gap in the protoplanetary disk that limited the inward drift of outer Solar System material at the exception of particles with size lower than 150 μm such as presolar grains. Among carbonaceous chondrites, CV chondrites show O-isotopic features suggesting potential contribution of 17-18O-rich water that may be related to their older accretion relative to other hydrated

Improvements in or relating to process for the production of fuel gas from a carbonaceous solid

Energy Technology Data Exchange (ETDEWEB)

1952-12-03

A process was designed for the generation of fuel gas from a solid carbonaceous fuel containing volatilizable constituents, which comprises admixing the solid carbonaceous fuel in particle form with sufficient water to form a fluid suspension, passing the suspension through a heating zone at an elevated temperature such that substantially all of the water is vaporized, thereby forming a dispersion of coal in steam and causing the dispersion to attain a velocity of at least 60 ft. per second to shatter the particles of coal by collision, passing the resulting dispersion into a fluidized bed of solid carbonaceous material in a methanization zone into contact with carbon monoxide and hydrogen at a temperature within the range of from 900/sup 0/ to 1,800/sup 0/F whereby carbon monoxide and hydrogen are converted to methane and volatilizable constituents of the solid carbonaceous material are distilled therefrom, withdrawing carbonaceous material from the methanization zone and passing it into contact with oxygen and steam in dilute phase in a gasification zone maintained at a temperature within the range of 2,000/sup 0/ to about 3,000/sup 0/F, passing the resulting gases comprising carbon monoxide and hydrogen from the gasification zone into the methanization zone as the source of carbon monoxide and hydrogen, and discharging the gaseous products of the methanization zone as the raw-product fuel gas.

Everyone Wins: A Mars-Impact Origin for Carbonaceous Phobos and Deimos

Science.gov (United States)

Fries, M.; Welzenbach, L.; Steele, A.

2016-01-01

Discussions of Phobos' and Deimos' origin(s) tend to feature an orthogonally opposed pair of observations: dynamical studies which favor coalescence of the moons from an orbital debris ring arising from a large impact on Mars; and reflectance spectroscopy of the moons that indicate a carbonaceous composition that is not consistent with Martian surface materials. One way to reconcile this discrepancy is to consider the option of a Mars-impact origin for Phobos and Deimos, followed by surficial decoration of carbon-rich materials by interplanetary dust particles (IDP). The moons experience a high IDP flux because of their location in Mars' gravity well. Calculations show that accreted carbon is sufficient to produce a surface with reflectance spectra resembling carbonaceous chondrites.

Process and apparatus for pyrolytic decomposition and coking of mixtures of finely divided solid carbonaceous material and hydrocarbon oils

Energy Technology Data Exchange (ETDEWEB)

Fisher, A

1933-09-18

A process is described for pyrolytic decomposition and coking of mixtures of finely divided solid and semi-solid carbonaceous material and hydrocarbon oils, whereby the mixture is first heated to a high temperature; the heated products are introduced into a coking zone, where vapors are separated from nonvaporous residue afterwards to be cracked and condensed, characterized in that the mixture is heated to a high temperature under substantially noncoking conditions and that nonvaporous residue obtained in the coking zone is coked as a relatively thin layer on an externally intensely heated surface, preferably of heat-conducting, fireproof material, such as carborundum, fused-aluminum oxide, or clay.

Mechanism of NH{sub 3} desorption during the reaction of H{sub 2} with nitrogen containing carbonaceous materials

Energy Technology Data Exchange (ETDEWEB)

Juan F. Espinal; Thanh N. Truong; Fanor Mondragon [University of Antioquia, Medellin (Colombia). Institute of Chemistry

2005-07-01

The continued increase in demand for natural gas has stimulated the interest in coal conversion to methane as synthetic natural gas by hydropyrolysis of coal (pyrolysis in a H{sub 2} atmosphere). Because the produced raw gas contains considerable amounts of gaseous N-containing products that have to be removed before delivering to final users, the information on distribution of coal-N is important for designing purification processes. It has been reported in the literature that NH{sub 3} is the main nitrogen containing gas that is released during the hydropyrolysis process. Other gases such as HCN and N{sub 2} are also released but in a much smaller amount. To the best of our knowledge, the mechanism for NH{sub 3} desorption during hydrogen reaction with carbonaceous materials has not been studied. We carried out a molecular modeling study using Density Functional Theory in order to get an insight of the mechanism and thermodynamics for NH{sub 3} evolution using pyridinic nitrogen as a model of N-containing carbonaceous material. We propose a mechanism that involves consecutive hydrogenation steps that lead to C-N bond breakage and NH{sub 3} desorption to the gas phase. It was found that the first hydrogenation reaction is highly exothermic. However, further hydrogenations are endothermic. Several pathways for NH{sub 3} evolution were proposed and most of them show high exothermicity. 17 refs., 2 figs.

Evolution of carbonaceous chondrite parent bodies: Insights into cometary nuclei

International Nuclear Information System (INIS)

McSween, H.Y. Jr.

1989-01-01

It is thought that cometary samples will comprise the most primitive materials that are able to be sampled. Although parent body alteration of such samples would not necessarily detract from scientists' interest in them, the possibility exists that modification processes may have affected cometary nuclei. Inferences about the kinds of modifications that might be encountered can be drawn from data on the evolution of carbonaceous chondrite parent bodies. Observations suggest that, of all the classes of chondrites, these meteorites are most applicable to the study of comets. If the proportion of possible internal heat sources such as Al-26 in cometary materials are similar to those in chondrites, and if the time scale of comet accretion was fast enough to permit incorporation of live radionuclides, comets might have had early thermal histories somewhat like those of carbonaceous chondrite parent bodies

Carbonaceous aerosols from prescribed burning of a boreal forest ecosystem

International Nuclear Information System (INIS)

Mazurek, M.A.; Cofer, W.R. III; Levine, J.S.

1991-01-01

Smoke aerosol and background aerosol particles were collected from the controlled burning of boreal forest where vegetation species and relative mass distributions are known. Chemical mass balances were constructed for the total mass of carbonaceous aerosol particles emitted during the prescribed burn. In addition, a carbonaceous species inventory was developed for aerosol particles presnt under background, smoldering, and full-fire conditions; the production of organic carbon and elemental carbon particles is noted for these two fire regimes. Distributions of the solvent-soluble organic components of the sampled aerosols were generated to identify molecular properties that can be traced to unburned and pyrolyzed materials present in the boreal forest fuels

Evaluation of early Archean volcaniclastic and volcanic flow rocks as possible sites for carbonaceous fossil microbes.

Science.gov (United States)

Walsh, Maud M

2004-01-01

Sedimentary rocks have traditionally been the focus of the search for Archean microfossils; the Earth's oldest fossil bacteria are associated with carbonaceous matter in sedimentary cherts in greenstone belts in the eastern Pilbara block of Western Australia and Barberton greenstone belt of South Africa. Reports of possible fossils in a martian meteorite composed of igneous rock and the discovery of modern bacteria associated with basalts have stimulated a new look at Archean volcanic rocks as possible sites for fossil microbes. This study examines silicified volcaniclastic rocks, near-surface altered volcanic flow rocks, and associated stromatolite- like structures from the Archean Barberton greenstone belt to evaluate their potential for the preservation of carbonaceous fossils. Detrital carbonaceous particles are widely admixed with current-deposited debris. Carbonaceous matter is also present in altered volcanic flow rocks as sparse particles in silica veins that appear to be fed by overlying carbonaceous chert layers. Neither microfossils nor mat-like material was identified in the altered volcanic rocks or adjacent stromatolite-like structures. Ancient volcanic flow and volcaniclastic rocks are not promising sites for carbonaceous fossil preservation.

The Thermal Properties of CM Carbonaceous Chondrites

Science.gov (United States)

Britt, D. T.; Opeil, C.

2017-12-01

The physical properties of asteroid exploration targets are fundamental parameters for developing models, planning observations, mission operations, reducing operational risk, and interpreting mission results. Until we have returned samples, meteorites represent our "ground truth" for the geological material we expect to interact with, sample, and interpret on the surfaces of asteroids. The physical properties of the volatile-rich carbonaceous chondrites (CI, C2, CM, and CR groups) are of particular interest because of their high resource potential. We have measured the thermal conductivity, heat capacity and thermal expansion of five CM carbonaceous chondrites (Murchison, Murray, Cold Bokkeveld, NWA 7309, Jbilet Winselwan) at low temperatures (5-300 K) to mimic the conditions in the asteroid belt. The mineralogy of these meteorites are dominated by abundant hydrous phyllosilicates, but also contain anhydrous minerals such as olivine and pyroxene found in chondrules. The thermal expansion measurements for all these CMs indicate a substantial increase in meteorite volume as temperature decreases from 230 - 210 K followed by linear contraction below 210 K. Such transitions were unexpected and are not typical for anhydrous carbonaceous chondrites or ordinary chondrites. Our thermal diffusivity results compare well with previous estimates for similar meteorites, where conductivity was derived from diffusivity measurements and modeled heat capacities; our new values are of a higher precision and cover a wider range of temperatures.

Functionalization of biomass carbonaceous aerogels: selective preparation of MnO2@CA composites for supercapacitors.

Science.gov (United States)

Ren, Yumei; Xu, Qun; Zhang, Jianmin; Yang, Hongxia; Wang, Bo; Yang, Daoyuan; Hu, Junhua; Liu, Zhimin

2014-06-25

Functionalized porous carbon materials with hierarchical structure and developed porosity coming from natural and renewable biomass have been attracting tremendous attention recently. In this work, we present a facile and scalable method to synthesize MnO2 loaded carbonaceous aerogel (MnO2@CA) composites via the hydrothermal carbonaceous (HTC) process. We employ two reaction systems of the mixed metal ion precursors to study the optimal selective adsorption and further reaction of MnO2 precursor on CA. Our experimental results show that the system containing KMnO4 and Na2S2O3·5H2O exhibits better electrochemical properties compared with the reaction system of MnSO4·H2O and (NH4)2S2O8. For the former, the obtained MnO2@CA displays the specific capacitance of 123.5 F·g(-1). The enhanced supercapacitance of MnO2@CA nanocomposites could be ascribed to both electrochemical contributions of the loaded MnO2 nanoparticles and the porous structure of three-dimensional carbonaceous aerogels. This study not only indicates that it is vital for the reaction systems to match with porous carbonaceous materials, but also offers a new fabrication strategy to prepare lightweight and high-performance materials that can be used in energy storage devices.

Microporous carbonaceous adsorbents for CO2 separation via selective adsorption

KAUST Repository

Zhao, Yunfeng

2015-01-01

Selective adsorption of CO2 has important implications for many energy and environment-related processes, which require the separation of CO2 from other gases (e.g. N2 and CH4) with high uptakes and selectivity. The development of high-performance adsorbents is one of the most promising solutions to the success of these processes. The present review is focused on the state-of-the-art of carbon-based (carbonaceous) adsorbents, covering microporous inorganic carbons and microporous organic polymers, with emphasis on the correlation between their textural and compositional properties and their CO2 adsorption/separation performance. Special attention is given to the most recently developed materials that were not covered in previous reviews. We summarize various effective strategies (N-doping, surface functionalization, extra-framework ions, molecular design, and pore size engineering) for enhancing the CO2 adsorption capacity and selectivity of carbonaceous adsorbents. Our discussion focuses on CO2/N2 separation and CO2/CH4 separation, while including an introduction to the methods and criteria used for evaluating the performance of the adsorbents. Critical issues and challenges regarding the development of high-performance adsorbents as well as some overlooked facts and misconceptions are also discussed, with the aim of providing important insights into the design of novel carbonaceous porous materials for various selective adsorption based applications. This journal is © The Royal Society of Chemistry.

Different effects of surface heterogeneous atoms of porous and non-porous carbonaceous materials on adsorption of 1,1,2,2-tetrachloroethane in aqueous environment.

Science.gov (United States)

Chen, Weifeng; Ni, Jinzhi

2017-05-01

The surface heterogeneous atoms of carbonaceous materials (CMs) play an important role in adsorption of organic pollutants. However, little is known about the surface heterogeneous atoms of CMs might generate different effect on adsorption of hydrophobic organic compounds by porous carbonaceous materials - activated carbons (ACs) and non-porous carbonaceous materials (NPCMs). In this study, we observed that the surface oxygen and nitrogen atoms could decrease the adsorption affinity of both ACs and NPCMs for 1,1,2,2-tetrachloroethane (TeCA), but the degree of decreasing effects were very different. The increasing content of surface oxygen and nitrogen ([O + N]) caused a sharper decrease in adsorption affinity of ACs (slope of lg (k d /SA) vs [O + N]: -0.098∼-0.16) than that of NPCMs (slope of lg (k d /SA) vs [O + N]: -0.025∼-0.059) for TeCA. It was due to the water cluster formed by the surface hydrophilic atoms that could block the micropores and generate massive invalid adsorption sites in the micropores of ACs, while the water cluster only occupied the surface adsorption sites of NPCMs. Furthermore, with the increasing concentration of dissolved TeCA, the effect of surface area on adsorption affinity of NPCMs for TeCA kept constant while the effect of [O + N] decreased due to the competitive adsorption between water molecule and TeCA on the surface of NPCMs, meanwhile, both the effects of micropore volume and [O + N] on adsorption affinity of ACs for TeCA were decreased due to the mechanism of micropore volume filling. These findings are valuable for providing a deep insight into the adsorption mechanisms of CMs for TeCA. Copyright © 2017 Elsevier Ltd. All rights reserved.

Indigenous Carbonaceous Matter in the Nakhla Mars Meteorite

Science.gov (United States)

Clemett, S. J.; Thomas-Keprta, K. L.; Rahman, Z.; Le, L.; Wentworth, S. J.; Gibson, E. K.; McKay, D. S.

2016-01-01

Detailed microanalysis of the Martian meteorite Nakhla has shown there are morphologically distinct carbonaceous features spatially associated with low-T aqueous alteration phases including salts and id-dingsite. A comprehensive suite of analytical instrumentation including optical microscopy, field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) spectroscopy, focused ion beam (FIB) microscopy, transmission electron microscopy (TEM), two-step laser mass spectrometry (mu-L(sup 2)MS), laser mu-Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and nanoscale secondary ion mass spectrometry (NanoSIMS) are being used to characterize the carbonaceous matter and host mineralogy. The search for carbonaceous matter on Mars has proved challenging. Viking Landers failed to unambiguously detect simple organics at either of the two landing sites although the Martian surface is estimated to have acquired at least 10(exp15) kg of C as a consequence of meteoritic accretion over the last several Ga. The dearth of organics at the Martian surface has been attributed to various oxidative processes including UV photolysis and peroxide activity. Consequently, investigations of Martian organics need to be focused on the sub-surface regolith where such surface processes are either severely attenuated or absent. Fortuitously since Martian meteorites are derived from buried regolith materials they provide a unique opportunity to study Martian organic geochemistry.

Carbonaceous deposits on naptha reforming catalysts

International Nuclear Information System (INIS)

Redwan, D.S.

1999-01-01

Carbonaceous deposits on naphtha reforming catalysts play a decisive role in limiting process performance. The deposits negatively after catalyst activity, selectivity and the production cycle of a semi regenerative reformer. The magnitude of negative effect of those deposits is directly proportional to their amounts and complexity. Investigations on used reforming catalysts samples reveal that the amount and type (complexity of the chemical nature) of carbonaceous deposits are directly proportional to the catalysts life on stream and the severity of operating conditions. In addition, the combustibility behavior of carbonaceous deposits on the catalyst samples taken from different reformers are found to be different. Optimal carbon removal, for in situ catalyst regeneration, requires the specific conditions be developed, based on the results of well designed and properly performed investigations of the amount and type of carbonaceous deposits. (author)

Extraterrestrial Nucleobases in Carbonaceous Chondrites

Science.gov (United States)

Martins, Z.; Botta, O.; Fogel, M.; Sephton, M.; Glavin, D.; Watson, J.; Dworkin, J.; Schwartz, A.; Ehrenfreund, P.

. Our stable carbon isotope measurements clearly demonstrate that the nucleobases in the Murchison meteorite are indigenous to the meteorite, and clearly differ from the values determined for the terrestrial nucleobases measured in the soil collected at the impact site. These results support the hypothesis that nucleobases were exogenously delivered to the early Earth, and may have been important for the prebiotic chemistry on our young planet. With regard to the detection of traces of life on other planets such as Mars it is essential to characterize organic materials that have been exogenously delivered to the early planets. The analysis of the composition and isotopic fractionation of extraterrestrial material using complementary techniques can provide crucial insights into the formation of our Solar System, extraterrestrial delivery processes and subsequent addition and incorporation into the carbonaceous material available on the young planets. Ultimately, these parameters form an essential reference point for interpreting biosignatures that may be left in the ancient rock record on a planetary body. References: [1] Hayatsu R. et al. 1975. Geochimica et Cosmochimica Acta 39: 471- 488. [2] Folsome C. E. et al. 1971. Nature 232: 108-109. [3] Stoks P. G. & Schwartz A. W. 1979. Nature 282: 709-710. [4] Stoks P.G. & Schwartz A. W. 1981. Geochimica et Cosmochimica Acta 45: 563-569. [5] Shimoyama A. et al. 1990. Geochemical Journal 24: 343-348. [6] Martins Z. et al. 2004. Meteoritics & Planetary Science 39: A5145. 2

KOH activation of pitch-derived carbonaceous materials - Effect of carbonization degree

Energy Technology Data Exchange (ETDEWEB)

Krol, Magdalena [Institute of Open Cast Mining POLTEGOR-Institute, Parkowa, Wroclaw (Poland); Gryglewicz, Grazyna; Machnikowski, Jacek [Division of Polymer and Carbonaceous Materials, Faculty of Chemistry, Wroclaw University of Technology, Gdanska (Poland)

2011-01-15

Two series of mesophase pitches and semi-cokes of different carbonization degree were produced by heat treatment of anthracene oil derived pitches P1 and P4 in the temperature range of 460-700 C. These carbonaceous materials were activated with potassium hydroxide at 700 C using 1:3 reagents ratio to assess the effects of the precursor optical texture and carbonization degree on the activation behavior. The results show that the increase in the pitch pretreatment temperature suppresses propensity to the pore generation while enhancing particle breaking. The effect can be illustrated by decreases in the BET surface area S{sub BET} from {proportional_to} 2700 to {proportional_to} 1500 m{sup 2} g{sup -1} and the micropore volume V{sub DR} from {proportional_to} 0.85 to {proportional_to} 0.45 cm{sup 3} g{sup -1}. These parameters are inversely related with the H/C atomic ratio of precursor. In contrast, the anisotropic development of pitch coke, varying from flow type to mosaics, has a slight effect on the activation behaviour. The mechanism of porosity generation, that is proposed, stresses the role of hydrogen occurring at the edges of graphene layers and potassium metal insertion/deinsertion on the porosity development and particle disintegration during KOH activation of pitch-derived carbons. (author)

The Role of Fe,Ni Metal and Fe,Ni Sulfide Nanoparticles in Catalytic Organic Synthesis in the Early Solar System: Evidence From Carbonaceous Chondrites.

Science.gov (United States)

Brearley, A. J.

2008-12-01

Numerous studies have shown that carbonaceous chondrites contain a wide variety of both soluble and insoluble organic compounds. These compounds formed in a variety of different astrophysical environments including the interstellar medium, the solar nebula and on asteroidal parent bodies. The solid or insoluble organic material (IOM) in carbonaceous chondrites is likely the complex end product of synthesis and processing in all of these environments. Although the bulk chemistry and structure of IOM in carbonaceous chondrites is well understood, important questions remain as to the exact spatial occurrence and distribution of organic material within carbonaceous chondrites. Such information may provide important insights into the possible mechanisms of formation of organic material at the grain scale. We have examined the matrices of three CM carbonaceous chondrites, Y791198, Murchison and ALH81002 using a range of different TEM techniques. Mineralogically, the matrices of these meteorites consist of phyllosilicates and/or amorphous materials associated with sulfides, oxides and carbides. Using energy filtered TEM several distinct occurrences of organic material have been identified, notably associations with nanoparticles of sulfide and carbide. Sulfides have grain sizes that are commonly <100 nm with thin layers of poorly graphitized C (<1 nm) on their surfaces. This carbonaceous layer often contains nitrogen suggesting that it is organic in character. In addition, nanoparticles of Fe,Ni carbides that occur either singly or in clusters are often embedded in carbonaceous material that is also N-bearing. These carbides have experienced partial oxidation to magnetite around their rims. The ubiquitous spatial association between sulfide and carbide nanoparticles and carbonaceous material indicates a genetic relation between these phases. This association can be most readily explained by Fischer-Tropsch-type (FTT) catalysis reactions involving catalytic hydrogenation

Global cloud condensation nuclei influenced by carbonaceous combustion aerosol

Directory of Open Access Journals (Sweden)

D. V. Spracklen

2011-09-01

Full Text Available Black carbon in carbonaceous combustion aerosol warms the climate by absorbing solar radiation, meaning reductions in black carbon emissions are often perceived as an attractive global warming mitigation option. However, carbonaceous combustion aerosol can also act as cloud condensation nuclei (CCN so they also cool the climate by increasing cloud albedo. The net radiative effect of carbonaceous combustion aerosol is uncertain because their contribution to CCN has not been evaluated on the global scale. By combining extensive observations of CCN concentrations with the GLOMAP global aerosol model, we find that the model is biased low (normalised mean bias = −77 % unless carbonaceous combustion aerosol act as CCN. We show that carbonaceous combustion aerosol accounts for more than half (52–64 % of global CCN with the range due to uncertainty in the emitted size distribution of carbonaceous combustion particles. The model predicts that wildfire and pollution (fossil fuel and biofuel carbonaceous combustion aerosol causes a global mean cloud albedo aerosol indirect effect of −0.34 W m⁻², with stronger cooling if we assume smaller particle emission size. We calculate that carbonaceous combustion aerosol from pollution sources cause a global mean aerosol indirect effect of −0.23 W m⁻². The small size of carbonaceous combustion particles from fossil fuel sources means that whilst pollution sources account for only one-third of the emitted mass they cause two-thirds of the cloud albedo aerosol indirect effect that is due to carbonaceous combustion aerosol. This cooling effect must be accounted for, along with other cloud effects not studied here, to ensure that black carbon emissions controls that reduce the high number concentrations of fossil fuel particles have the desired net effect on climate.

Influence of hydrothermal carbonization and treatment by microwave on morphology of carbonaceous materials obtained from lignin

International Nuclear Information System (INIS)

Oliveira, I.B.; Barin, G.B.; Barreto, L.S.; Santos, M.C.G.

2014-01-01

The conversion of biomass into carbon materials with special morphologies via hydrothermal carbonization presents itself as a potential route for the use of renewable precursors in obtaining carbonaceous structures. In the present study the influence of the hydrothermal carbonization (250 ° C / 4 h) followed by microwave treatment (1-2-4 hours at 25 and 40 mL) in morphology and structure of lignin. The samples were analyzed by X-ray diffraction and scanning electron microscopy. The plaque morphology of lignin was preserved during the hydrothermal process. However, when treated by microwave can be observed partial dissolution of lignin leading to the formation of microspheres on the surface. XRD presence of an amorphous halo 2θ = 23 ° attributed to the (002) network of the amorphous carbon was observed. (author)

Detection of serpentine in exogenic carbonaceous chondrite material on Vesta from Dawn FC data

Science.gov (United States)

Nathues, Andreas; Hoffmann, Martin; Cloutis, Edward A.; Schäfer, Michael; Reddy, Vishnu; Christensen, Ulrich; Sierks, Holger; Thangjam, Guneshwar Singh; Le Corre, Lucille; Mengel, Kurt; Vincent, Jean-Baptist; Russell, Christopher T.; Prettyman, Tom; Schmedemann, Nico; Kneissl, Thomas; Raymond, Carol; Gutierrez-Marques, Pablo; Hall, Ian; Büttner, Irene

2014-09-01

The Dawn mission’s Framing Camera (FC) observed Asteroid (4) Vesta in 2011 and 2012 using seven color filters and one clear filter from different orbits. In the present paper we analyze recalibrated HAMO color cubes (spatial resolution ∼60 m/pixel) with a focus on dark material (DM). We present a definition of highly concentrated DM based on spectral parameters, subsequently map the DM across the Vestan surface, geologically classify DM, study its spectral properties on global and local scales, and finally, compare the FC in-flight color data with laboratory spectra. We have discovered an absorption band centered at 0.72 μm in localities of DM that show the lowest albedo values by using FC data as well as spectral information from Dawn’s imaging spectrometer VIR. Such localities are contained within impact-exposed outcrops on inner crater walls and ejecta material. Comparisons between spectral FC in-flight data, and laboratory spectra of meteorites and mineral mixtures in the wavelength range 0.4-1.0 μm, revealed that the absorption band can be attributed to the mineral serpentine, which is typically present in CM chondrites. Dark material in its purest form is rare on Vesta’s surface and is distributed globally in a non-uniform manner. Our findings confirm the hypothesis of an exogenic origin of the DM by the infall of carbonaceous chondritic material, likely of CM type. It further confirms the hypothesis that most of the DM was deposited by the Veneneia impact.

Template-free synthesis of multifunctional carbonaceous microcone forests

Science.gov (United States)

Wang, Qiang; Yang, Lei; Dai, Bing; Bai, Jie; Yang, Zhenhuai; Guo, Shuai; He, Yurong; Han, Jiecai; Zhu, Jiaqi

2018-01-01

Forests of vertically aligned carbonaceous microcones are fabricated directly on a nickel mesh by microwave-plasma-assisted chemical vapor deposition. The microstructure is formed through a simple one-step process involving self-assembly. The fabricated composite exhibits superhydrophobicity and superoleophilicity as well as low density, owing to which it floats on water and can be used for the in-situ separation of oil from water at the oil/water interface. Furthermore, the composite exhibits pH responsivity, and its water permeability can be varied simply by altering the pH of the aqueous solution. In addition, the composite is suitable for use as an electrode material for supercapacitors owing to its large geometric surface area, porous structure, and superior electrical properties, which allow for fast ion and electron transportation. Thus, this composite consisting of forests of vertically aligned carbonaceous microcones on a nickel mesh is expected to find use in a wide range of fields and applications, including in environmental cleanup, flow switches, and energy storage devices.

Adsorption of perfluoroalkyl acids by carbonaceous adsorbents: Effect of carbon surface chemistry

International Nuclear Information System (INIS)

Zhi, Yue; Liu, Jinxia

2015-01-01

Adsorption by carbonaceous sorbents is among the most feasible processes to remove perfluorooctane sulfonic (PFOS) and carboxylic acids (PFOA) from drinking and ground waters. However, carbon surface chemistry, which has long been recognized essential for dictating performance of such sorbents, has never been considered for PFOS and PFOA adsorption. Thus, the role of surface chemistry was systematically investigated using sorbents with a wide range in precursor material, pore structure, and surface chemistry. Sorbent surface chemistry overwhelmed physical properties in controlling the extent of uptake. The adsorption affinity was positively correlated carbon surface basicity, suggesting that high acid neutralizing or anion exchange capacity was critical for substantial uptake of PFOS and PFOA. Carbon polarity or hydrophobicity had insignificant impact on the extent of adsorption. Synthetic polymer-based Ambersorb and activated carbon fibers were more effective than activated carbon made of natural materials in removing PFOS and PFOA from aqueous solutions. - Highlights: • Adsorption of PFOS and PFOA by ten carbonaceous adsorbents were compared. • Surface chemistry of the adsorbents controlled adsorption affinity. • Carbon surface basicity was positively correlated with the extent of PFOS and PFOA uptake. • Carbon polarity or hydrophobicity was not correlated with adsorption affinity. • Synthetic polymer-based adsorbents were more effective in removing PFOS and PFOA. - Carbon surface basicity is the primary factor that influences adsorption affinity of the carbonaceous sorbents for perfluorooctane sulfonic and carboxylic acids

Understanding the Organo-Carbonate Associations in Carbonaceous Chondrites with the Use of Micro-Raman Analysis

Science.gov (United States)

Chan, Q. H. S.; Zolensky, M. E.

2015-01-01

Carbonates can potentially provide sites for organic materials to accrue and develop into complex macromolecules. This study examines the organics associated with carbonates in carbonaceous chondrites using micron-Raman imaging.

Acid/base bifunctional carbonaceous nanomaterial with large surface area: Preparation, characterization, and adsorption properties for cationic and anionic compounds

Energy Technology Data Exchange (ETDEWEB)

Li, Kai; Ma, Chun–Fang; Ling, Yuan; Li, Meng [Department of Chemistry, Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074 (China); Gao, Qiang, E-mail: gaoqiang@cug.edu.cn [Department of Chemistry, Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074 (China); Engineering Research Center of Nano-Geo Materials of Ministry of Education, China University of Geosciences, Wuhan 430074 (China); Luo, Wen–Jun, E-mail: heartnohome@yahoo.com.cn [Department of Chemistry, Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074 (China)

2015-07-15

Nanostructured carbonaceous materials are extremely important in the nano field, yet developing simple, mild, and “green” methods that can make such materials possess large surface area and rich functional groups on their surfaces still remains a considerable challenge. Herein, a one-pot and environment-friendly method, i.e., thermal treatment (180 °C; 18 h) of water mixed with glucose and chitosan (CTS), has been proposed. The resultant carbonaceous nanomaterials were characterized by field emitting scanning electron microscope, N{sub 2} adsorption/desorption, Fourier transform infrared spectroscope, X-ray photoelectron spectroscopy, and zeta-potential analysis. It was found that, in contrast to the conventional hydrothermally carbonized product from pure glucose, with low surface area (9.3 m{sup 2} g{sup −1}) and pore volume (0.016 cm{sup 3} g{sup −1}), the CTS-added carbonaceous products showed satisfactory textural parameters (surface area and pore volume up to 254 m{sup 2} g{sup −1} and 0.701 cm{sup 3} g{sup −1}, respectively). Moreover, it was also interestingly found that these CTS-added carbonaceous products possessed both acidic (–COOH) and basic (–NH{sub 2}) groups on their surfaces. Taking the advantages of large surface area and –COOH/–NH{sub 2} bifunctional surface, the carbonaceous nanomaterials exhibited excellent performance for adsorptions of cationic compound (i.e., methylene blue) at pH 10 and anionic compound (i.e., acid red 18) at pH 2, respectively. This work not only provides a simple and green route to prepare acid/base bifunctional carbonaceous nanomaterials with large surface area but also well demonstrates their potential for application in adsorption. - Highlights: • A simple and green method was proposed to prepare carbon nanomaterials. • The carbon product showed acid/base bifunctional surface with large surface area. • The carbon material could efficiently adsorb both cationic and anionic compounds.

The use of halogen carriers and buffers in the spectrographic determination of boron in carbonaceous materials and their combustion products

International Nuclear Information System (INIS)

Rucandio, M.I.; Martin, M.; Roca, M.

1992-01-01

For the determination of boron in carbonaceous materials (high purity graphite, coals and their processed products, such as ashes and slags from thermoelectric power plants) by atomic emission spectroscopy with direct current arc excitation and photographic recording, the behaviour of the analyte in the presence of halide compounds or spectrochemical buffers has been studied. Among the halides, cupric fluoride at a low concentration (2%) becomes very suitable for the graphite analysis, and at a higher concentration (25%) for coals being necessary in this case to carry out a dilution of samples with graphite. Strontium carbonate as a spectrochemical buffer allows to analyse satisfactorily coals and their combustion products. (author)

The use of halogen carriers and buffers in the spectrographic determination of boron in carbonaceous materials and their combustion products

International Nuclear Information System (INIS)

Rucandio, M. I.; Martin, M.; Roca, M.

1992-01-01

For the determination of boron in carbonaceous materials (high purity graphite, coals and their processed products, such as ashes and slags from thermoelectric power plants) by atomic emission spectroscopy with direct current are excitation and photographic recording, the behaviour of the analyte in the presence of halide compounds or spectrochemical buffers has been studied. Among the halides, cupric fluoride at a low concentration (2%) becomes very suitable for the graphite analysis, and at a higher concentration (25 %) for coals, being necessary in this case to carry out a dilution of samples with graphite. Strontium carbonate as a spectrochemical buffer allows to analyse satisfactorily coals and their combustion products. (Author) 13 refs

Field effect transistors and photodetectors based on nanocrystalline graphene derived from electron beam induced carbonaceous patterns

International Nuclear Information System (INIS)

Kurra, Narendra; Bhadram, Venkata Srinu; Narayana, Chandrabhas; Kulkarni, G U

2012-01-01

We describe a transfer-free method for the fabrication of nanocrystalline graphene (nc-graphene) on SiO 2 substrates directly from patterned carbonaceous deposits. The deposits were produced from the residual hydrocarbons present in the vacuum chamber without any external source by using an electron beam induced carbonaceous deposition (EBICD) process. Thermal treatment under vacuum conditions in the presence of Ni catalyst transformed the EBIC deposit into nc-graphene patterns, confirmed using Raman and TEM analysis. The nc-graphene patterns have been employed as an active p-type channel material in a field effect transistor (FET) which showed a hole mobility of ∼90 cm 2 V −1 s −1 . The nc-graphene also proved to be suitable material for IR detection. (paper)

Ordered mixed-layer structures in the Mighei carbonaceous chondrite matrix

Science.gov (United States)

Mackinnon, I. D. R.

1982-01-01

High resolution transmission electron microscopy of the Mighei carbonaceous chondrite matrix has revealed the presence of a new mixed layer structure material. This mixed-layer material consists of an ordered arrangement of serpentine-type (S) and brucite-type (B) layers in the sequence SBBSBB. Electron diffraction and imaging techniques show that the basal periodicity is approximately 17 A. Discrete crystals of SBB-type material are typically curved, of small size (less than 1 micron) and show structural variations similar to the serpentine group minerals. Mixed-layer material also occurs in association with planar serpentine. Characteristics of SBB-type material are not consistent with known terrestrial mixed-layer clay minerals. Evidence for formation by a condensation event or by subsequent alteration of pre-existing material is not yet apparent.

Density functional theory study the effects of oxygen-containing functional groups on oxygen molecules and oxygen atoms adsorbed on carbonaceous materials.

Science.gov (United States)

Qi, Xuejun; Song, Wenwu; Shi, Jianwei

2017-01-01

Density functional theory was used to study the effects of different types of oxygen-containing functional groups on the adsorption of oxygen molecules and single active oxygen atoms on carbonaceous materials. During gasification or combustion reactions of carbonaceous materials, oxygen-containing functional groups such as hydroxyl(-OH), carbonyl(-CO), quinone(-O), and carboxyl(-COOH) are often present on the edge of graphite and can affect graphite's chemical properties. When oxygen-containing functional groups appear on a graphite surface, the oxygen molecules are strongly adsorbed onto the surface to form a four-member ring structure. At the same time, the O-O bond is greatly weakened and easily broken. The adsorption energy value indicates that the adsorption of oxygen molecules changes from physisorption to chemisorption for oxygen-containing functional groups on the edge of a graphite surface. In addition, our results indicate that the adsorption energy depends on the type of oxygen-containing functional group. When a single active oxygen atom is adsorbed on the bridge site of graphite, it gives rise to a stable epoxy structure. Epoxy can cause deformation of the graphite lattice due to the transition of graphite from sp2 to sp3 after the addition of an oxygen atom. For quinone group on the edge of graphite, oxygen atoms react with carbon atoms to form the precursor of CO2. Similarly, the single active oxygen atoms of carbonyl groups can interact with edge carbon atoms to form the precursor of CO2. The results show that oxygen-containing functional groups on graphite surfaces enhance the activity of graphite, which promotes adsorption on the graphite surface.

Methods for purifying carbon materials

Science.gov (United States)

Dailly, Anne [Pasadena, CA; Ahn, Channing [Pasadena, CA; Yazami, Rachid [Los Angeles, CA; Fultz, Brent T [Pasadena, CA

2009-05-26

Methods of purifying samples are provided that are capable of removing carbonaceous and noncarbonaceous impurities from a sample containing a carbon material having a selected structure. Purification methods are provided for removing residual metal catalyst particles enclosed in multilayer carbonaceous impurities in samples generate by catalytic synthesis methods. Purification methods are provided wherein carbonaceous impurities in a sample are at least partially exfoliated, thereby facilitating subsequent removal of carbonaceous and noncarbonaceous impurities from the sample. Methods of purifying carbon nanotube-containing samples are provided wherein an intercalant is added to the sample and subsequently reacted with an exfoliation initiator to achieve exfoliation of carbonaceous impurities.

Abodes for life in carbonaceous asteroids?

Science.gov (United States)

Abramov, Oleg; Mojzsis, Stephen J.

2011-05-01

Thermal evolution models for carbonaceous asteroids that use new data for permeability, pore volume, and water circulation as input parameters provide a window into what are arguably the earliest habitable environments in the Solar System. Plausible models of the Murchison meteorite (CM) parent body show that to first-order, conditions suitable for the stability of liquid water, and thus pre- or post-biotic chemistry, could have persisted within these asteroids for tens of Myr. In particular, our modeling results indicate that a 200-km carbonaceous asteroid with a 40% initial ice content takes almost 60 Myr to cool completely, with habitable temperatures being maintained for ˜24 Myr in the center. Yet, there are a number of indications that even with the requisite liquid water, thermal energy sources to drive chemical gradients, and abundant organic "building blocks" deemed necessary criteria for life, carbonaceous asteroids were intrinsically unfavorable sites for biopoesis. These controls include different degrees of exothermal mineral hydration reactions that boost internal warming but effectively remove liquid water from the system, rapid (1-10 mm yr -1) inward migration of internal habitable volumes in most models, and limitations imposed by low permeabilities and small pore sizes in primitive undifferentiated carbonaceous asteroids. Our results do not preclude the existence of habitable conditions on larger, possibly differentiated objects such as Ceres and the Themis family asteroids due to presumed longer, more intense heating and possible long-lived water reservoirs.

Electron spin resonance and its application to heat treated carbonaceous materials; A ressonancia de spin eletronico e sua aplicacao aos materiais carbonosos tratados termicamente

Energy Technology Data Exchange (ETDEWEB)

Emmerich, Francisco Guilherme [Espirito Santo Univ., Vitoria, ES (Brazil). Laboratorio de Materiais Carbonosos e Plasma Termico

1994-12-31

This work presents the basic characteristics of the electron spin resonance technique, also called paramagnetic resonance, being discussed its application to heat treated carbonaceous materials. In the low heat treatment temperature (HTT) range (below 700 deg C) the organic free radical are the predominant unpaired spin center, which play a key role in the process of carbonization and meso phase formation. At higher temperatures, it is possible to make correlations between the low H T T range and the high HTT range (above 130 deg C), where the predominant unpaired spin center are the free charge carriers (free electrons) of the graphite like crystallites of the material, which are formed by the carbonization process. (author) 10 refs., 3 figs.

Solar radiation synthesis of functional carbonaceous materials using Al2O3/TiO2-Cu-HA doped catalyst

Science.gov (United States)

Stanciu, Elena Manuela; Pascu, Alexandru; Roată, Ionut Claudiu; Croitoru, Cătălin; Tierean, Mircea; Rosca, Julia Mirza; Hulka, Iosif

2018-04-01

Single carbon nanotubes were synthesized through a physical vapor deposition method, using concentrated solar radiation as means of vaporization and promoting the formation of carbonaceous plasma plume. A novel catalyst, containing multiple hybrid ceramic/metal phases has been obtained through flame spraying. In conjunction with this catalyst, good quality nanomaterials, such as long single-walled nanotubes and nanoparticles have been obtained and characterized by both morphological (SEM, TEM) as well as structural means on analysis (XRD, FTIR). A mild oxidation of the carbonaceous phase has been reported, which could prove useful in applications in conjunction with metals or hydrophilic polymers as potential matrices for nanocomposites obtaining.

Carbonaceous aerosols from prescribed burning of a boreal forest ecosystem

International Nuclear Information System (INIS)

Mazurek, M.A.; Cofer, W.R. III; Levine, J.S.

1990-10-01

The identity and ambient mass concentrations of radiatively important carbonaceous aerosols were measured for a boreal forest prescribed burn conducted in northern Ontario, CAN in August 1989. Nonsize-segregated airborne particles were collected for smoldering-fire and full-fire conditions using a helicopter sampling platform. Total carbon (TC), organic carbon (OC) and elemental carbon (EC) were measured. Smoke plume mass concentrations of the OC and EC particles were greatest for full-fire conditions and had ranges of 1.560 to 2.160 mg/m -1 (OC) and 0.120 to 0.160 mg/m -3 (EC) with OC:EC ratios of 10 to 18, respectively. Smoldering fire conditions showed smoke plume OC and EC levels of 0.570--1.030 mg/m -3 (OC) and 0.006--0.050 mg/m -3 (EC) and much higher ratios of OC:EC (21 to 95). These aerosol data indicate the formation of EC particles is greatest during full-fire combustion of boreal forest material relative to smoldering combustion. However, EC particles comprise a minor fraction of the particulate carbon smoke aerosols for both full-fire and smoldering conditions; the major component of carbonaceous smoke aerosols emitted during the prescribed burn is OC. Overall, the OC and EC in-plume smoke aerosol data show nonuniform production of these particles during various stages of the prescribed burn, and major differences in the type of carbonaceous aerosol that is generated (OC versus EC)

Impact of carbonaceous materials in soil on the transport of soil-bound PAHs during rainfall-runoff events.

Science.gov (United States)

Luo, Xiaolin; Zheng, Yi; Wu, Bin; Lin, Zhongrong; Han, Feng; Zhang, Wei; Wang, Xuejun

2013-11-01

Polycyclic Aromatic Hydrocarbons (PAHs) transported from contaminated soils by surface runoff pose significant risk for aquatic ecosystems. Based on a rainfall-runoff simulation experiment, this study investigated the impact of carbonaceous materials (CMs) in soil, identified by organic petrology analysis, on the transport of soil-bound PAHs under rainfall conditions. The hypothesis that composition of soil organic matter significantly impacts the enrichment and transport of PAHs was proved. CMs in soil, varying significantly in content, mobility and adsorption capacity, act differently on the transport of PAHs. Anthropogenic CMs like black carbon (BC) largely control the transport, as PAHs may be preferentially attached to them. Eventually, this study led to a rethink of the traditional enrichment theory. An important implication is that CMs in soil have to be explicitly considered to appropriately model the nonpoint source pollution of PAHs (possibly other hydrophobic chemicals as well) and assess its environmental risk. Copyright © 2013 Elsevier Ltd. All rights reserved.

Selective reduction of nitric oxide over Cu/ZSM-5: The role of oxygen in suppressing catalyst deactivation by carbonaceous deposits

Energy Technology Data Exchange (ETDEWEB)

d' Itri, Julie L; Sachtler, Wolfgang M.H. [V.N. Ipatieff Laboratory, Center for Catalysis and Surface Science, Departments of Chemical Engineering and Chemistry, Northwestern University, Evanston, IL (United States)

1993-06-15

The role of oxygen in the selective reduction of nitrogen monoxide by either propane or propene over 'excessively' ion-exchanged Cu/ZSM-5 has been studied. In a wide temperature region and in the absence of additives such as steam, propane is a more effective reductant than propene; with propane and in the presence of oxygen reduction of nitric oxide to nitrogen approaches 100% above 600 K. The difference in effectiveness is due to the different degree of catalyst deactivation by carbonaceous deposits: more carbonaceous material is deposited from propene than from propane. Temperature-programmed oxidation shows that above 600 K the rate of oxidation of carbonaceous deposits by oxygen is significant. The amount of such carbonaceous deposits is, therefore, lower when catalytic tests above 600 K are done in the presence of oxygen. At very high temperatures, the in situ volatilization of the deposits by reaction with oxygen keeps the catalyst surface clean in the steady state of nitric oxide reduction.

Thermodynamic Property Surfaces for Adsorption of R507A, R134a, and n -Butane on Pitch-Based Carbonaceous Porous Materials

KAUST Repository

Chakraborty, Anutosh

2010-10-01

The thermodynamic property surfaces of R507A, R134a, and n-butane on pitch-based carbonaceous porous material (Maxsorb III) are developed from rigorous classical thermodynamics and experimentally measured adsorption isotherm data. These property fields enable us to compute the entropy, enthalpy, internal energy, and heat of adsorption as a function of pressure, temperature, and the amount of adsorbate. The entropy and enthalpy maps are necessary for the analysis of adsorption cooling cycle and gas storage. We have shown here that it is possible to plot an adsorption cooling cycle on the temperature-entropy (T-s) and enthalpy-uptake (h-x) maps. Copyright © Taylor and Francis Group, LLC 2010.

Thermodynamic Property Surfaces for Adsorption of R507A, R134a, and n -Butane on Pitch-Based Carbonaceous Porous Materials

KAUST Repository

Chakraborty, Anutosh; Saha, Bidyut Baran; Ng, Kim Choon; El-Sharkawy, Ibrahim I.; Koyama, Shigeru

2010-01-01

The thermodynamic property surfaces of R507A, R134a, and n-butane on pitch-based carbonaceous porous material (Maxsorb III) are developed from rigorous classical thermodynamics and experimentally measured adsorption isotherm data. These property fields enable us to compute the entropy, enthalpy, internal energy, and heat of adsorption as a function of pressure, temperature, and the amount of adsorbate. The entropy and enthalpy maps are necessary for the analysis of adsorption cooling cycle and gas storage. We have shown here that it is possible to plot an adsorption cooling cycle on the temperature-entropy (T-s) and enthalpy-uptake (h-x) maps. Copyright © Taylor and Francis Group, LLC 2010.

Wet, Carbonaceous Asteroids: Altering Minerals, Changing Amino Acids

Science.gov (United States)

Taylor, G. J.

2011-04-01

Many carbonaceous chondrites contain alteration products from water-rock interactions at low temperature and organic compounds. A fascinating fact known for decades is the presence in some of them of an assortment of organic compounds, including amino acids, sometimes called the building blocks of life. Murchison and other CM carbonaceous chondrites contain hundreds of amino acids. Early measurements indicated that the amino acids in carbonaceous chondrites had equal proportions of L- and D-structures, a situation called racemic. This was in sharp contrast to life on Earth, which heavily favors L- forms. However, beginning in 1997, John Cronin and Sandra Pizzarello (Arizona State University) found L- excesses in isovaline and several other amino acids in the Murchison carbonaceous chondrite. In 2009, Daniel Glavin and Jason Dworkin (Astrobiology Analytical Lab, Goddard Space Flight Center) reported the first independent confirmation of L-isovaline excesses in Murchison using a different analytical technique than employed by Cronin and Pizzarello. Inspired by this work, Daniel Glavin, Michael Callahan, Jason Dworkin, and Jamie Elsila (Astrobiology Analytical Lab, Goddard Space Flight Center), have done an extensive study of the abundance and symmetry of amino acids in carbonaceous chondrites that experienced a range of alteration by water in their parent asteroids. The results show that amino acids are more abundant in the less altered meteorites, implying that aqueous processing changes the mix of amino acids. They also confirmed the enrichment in L-structures of some amino acids, especially isovaline, confirming earlier work. The authors suggest that aqueously-altered planetesimals might have seeded the early Earth with nonracemic amino acids, perhaps explaining why life from microorganisms to people use only L- forms to make proteins. The initial imbalance caused by non-biologic processes in wet asteroids might have been amplified by life on Earth. Alternatively

Pulmonary exposure to carbonaceous nanomaterials and sperm quality

DEFF Research Database (Denmark)

Skovmand, Astrid; Lauvas, Anna Jacobsen; Christensen, Preben

2018-01-01

Background: Semen quality parameters are potentially affected by nanomaterials in several ways: Inhaled nanosized particles are potent inducers of pulmonary inflammation, leading to the release of inflammatory mediators. Small amounts of particles may translocate from the lungs into the lung...... inflammation is a potential modulator of endocrine function. The aim of this study was to investigate the effects of pulmonary exposure to carbonaceous nanomaterials on sperm quality parameters in an experimental mouse model.Methods: Effects on sperm quality after pulmonary inflammation induced by carbonaceous...... nanomaterials were investigated by intratracheally instilling sexually mature male NMRI mice with four different carbonaceous nanomaterials dispersed in nanopure water: graphene oxide (18 mu g/mouse/i.t.), Flammruss 101, Printex 90 and SRM1650b (0.1 mg/mouse/i.t. each) weekly for seven consecutive weeks...

Carbonaceous material production from vegetable residue and their use in the removal of textile dyes present in wastewater

Science.gov (United States)

Peláez-Cid, A. A.; Tlalpa-Galán, M. A.; Herrera-González, A. M.

2013-06-01

This paper presents the adsorption results of acid, basic, direct, vat, and reactive-type dyes on carbonaceous adsorbent materials prepared starting off vegetable residue such as Opuntia ficus indica and Casimiroa edulis fruit wastes. The adsorbents prepared from Opuntia ficus indica waste were designated: TunaAsh, CarTunaT, and CarTunaQ. The materials obtained from Casimiroa edulis waste were named: CenZAP, CarZAPT, and CarZAPQ. TunaAsh and CenZAP consist of ashes obtained at 550 °C CarTunaT and CarZAPT consist of the materials carbonized at 400 °C lastly, CarTunaQ and CarZAPQ consist of chemically activated carbons using H3PO4 at 400 °C. Only the chemically activated materials were washed with distilled water until a neutral pH was obtained after their carbonization. All materials were ground and sieved to obtain a particle size ranging from 0.25 to 0.84 mm. The static adsorption results showed that both ashes and chemically activated carbon are more efficient at dye removal for both vegetable residues. For TunaAsh and CarTunaQ, removal rates of up to 100% in the cases of basic, acid, and direct dyes were achieved. Regarding wastewater containing reactive dyes, the efficiency ranged from 60 to 100%. For vat effluents, it ranged from 42 to 52%. In the case of CenZAP and CarZAPQ, it was possible to treat reactive effluents with rates ranging between 63 and 91%. Regarding vat effluents, it ranged from 57 to 68%. The process of characterization for all materials was done using scanning electron microscopy and infrared spectroscopy.

Carbonaceous material production from vegetable residue and their use in the removal of textile dyes present in wastewater

International Nuclear Information System (INIS)

Peláez-Cid, A A; Tlalpa-Galán, M A; Herrera-González, A M

2013-01-01

This paper presents the adsorption results of acid, basic, direct, vat, and reactive-type dyes on carbonaceous adsorbent materials prepared starting off vegetable residue such as Opuntia ficus indica and Casimiroa edulis fruit wastes. The adsorbents prepared from Opuntia ficus indica waste were designated: TunaAsh, CarTunaT, and CarTunaQ. The materials obtained from Casimiroa edulis waste were named: CenZAP, CarZAPT, and CarZAPQ. TunaAsh and CenZAP consist of ashes obtained at 550 °C; CarTunaT and CarZAPT consist of the materials carbonized at 400 °C; lastly, CarTunaQ and CarZAPQ consist of chemically activated carbons using H 3 PO 4 at 400 °C. Only the chemically activated materials were washed with distilled water until a neutral pH was obtained after their carbonization. All materials were ground and sieved to obtain a particle size ranging from 0.25 to 0.84 mm. The static adsorption results showed that both ashes and chemically activated carbon are more efficient at dye removal for both vegetable residues. For TunaAsh and CarTunaQ, removal rates of up to 100% in the cases of basic, acid, and direct dyes were achieved. Regarding wastewater containing reactive dyes, the efficiency ranged from 60 to 100%. For vat effluents, it ranged from 42 to 52%. In the case of CenZAP and CarZAPQ, it was possible to treat reactive effluents with rates ranging between 63 and 91%. Regarding vat effluents, it ranged from 57 to 68%. The process of characterization for all materials was done using scanning electron microscopy and infrared spectroscopy.

Mineral associations and character of isotopically anomalous organic material in the Tagish Lake carbonaceous chondrite

Science.gov (United States)

Zega, Thomas J.; Alexander, Conel M. O.'D.; Busemann, Henner; Nittler, Larry R.; Hoppe, Peter; Stroud, Rhonda M.; Young, Andrea F.

2010-10-01

We report a coordinated analytical study of matrix material in the Tagish Lake carbonaceous chondrite in which the same small (⩽20 μm) fragments were measured by secondary ion mass spectrometry (SIMS), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), electron energy-loss spectroscopy (EELS), and X-ray absorption near-edge spectroscopy (XANES). SIMS analysis reveals H and N isotopic anomalies (hotspots), ranging from hundreds to thousands of nanometers in size, which are present throughout the fragments. Although the differences in spatial resolution of the SIMS techniques we have used introduce some uncertainty into the exact location of the hotspots, in general, the H and N isotopic anomalies are spatially correlated with C enrichments, suggesting an organic carrier. TEM analysis, enabled by site-specific extraction using a focused-ion-beam scanning-electron microscope, shows that the hotspots contain an amorphous component, Fe-Ni sulfides, serpentine, and mixed-cation carbonates. TEM imaging reveals that the amorphous component occurs in solid and porous forms, EDS indicates that it contains abundant C, and EELS and XANES at the C K edge reveal that it is largely aromatic. This amorphous component is probably macromolecular C, likely the carrier of the isotopic anomalies, and similar to the material extracted from bulk samples as insoluble organic matter. However, given the large sizes of some of the hotspots, the disparity in spatial resolution among the various techniques employed in our study, and the phases with which they are associated, we cannot entirely rule out that some of the isotopic anomalies are carried by inorganic material, e.g., sheet silicates. The isotopic composition of the organic matter points to an initially primitive origin, quite possibly within cold interstellar clouds or the outer reaches of the solar protoplanetary disk. The association of organic material with secondary phases, e.g., serpentine

Porous carbonaceous electrode structure and method for secondary electrochemical cell

Science.gov (United States)

Kaun, Thomas D.

1977-03-08

Positive and negative electrodes are provided as rigid, porous carbonaceous matrices with particulate active material fixedly embedded. Active material such as metal chalcogenides, solid alloys of alkali metal or alkaline earth metals along with other metals and their oxides in particulate form are blended with a thermosetting resin and a solid volatile to form a paste mixture. Various electrically conductive powders or current collector structures can be blended or embedded into the paste mixture which can be molded to the desired electrode shape. The molded paste is heated to a temperature at which the volatile transforms into vapor to impart porosity as the resin begins to cure into a rigid solid structure.

Organic free radicals and micropores in solid graphitic carbonaceous matter at the Oklo natural fission reactors, Gabon

International Nuclear Information System (INIS)

Rigali, M.J.; Nagy, B.

1997-01-01

The presence, concentration, and distribution of organic free radicals as well as their association with specific surface areas and microporosities help characterize the evolution and behavior of the Oklo carbonaceous matter. Such information is necessary in order to evaluate uranium mineralization, liquid bitumen solidification, and radio nuclide containment at Oklo. In the Oklo ore deposits and natural fission reactors carbonaceous matter is often referred to as solid graphitic bitumen. The carbonaceous parts of the natural reactors may contain as much as 65.9% organic C by weight in heterogeneous distribution within the clay-rich matrix. The solid carbonaceous matter immobilized small uraninite crystals and some fission products enclosed in this uraninite and thereby facilitated radio nuclide containment in the reactors. Hence, the Oklo natural fission reactors are currently the subjects of detailed studies because they may be useful analogues to support performance assessment of radio nuclide containment at anthropogenic radioactive waste repository sites. Seven carbonaceous matter rich samples from the 1968 ± 50 Ma old natural fission reactors and the associated Oklo uranium ore deposit were studied by electron spin resonance (ESR) spectroscopy and by measurements of specific surface areas (BET method). Humic acid, fulvic acid, and fully crystalline graphite standards were also examined by ESR spectroscopy for comparison with the Oklo solid graphitic bitumens. With one exception, the ancient Oklo bitumens have higher organic free radical concentrations than the modem humic and fulvic acid samples. The presence of carbon free radicals in the graphite standard could not be determined due to the conductivity of this material. 72 refs., 7 figs., 1 tab

TESTING OF CARBONACEOUS ADSORBENTS FOR REMOVAL OF POLLUTANTS FROM WATER

Directory of Open Access Journals (Sweden)

RAISA NASTAS

2012-03-01

Full Text Available Testing of carbonaceous adsorbents for removal of pollutants from water. Relevant direction for improving of quality of potable water is application of active carbons at various stages of water treatments. This work includes complex research dealing with testing of a broad spectrum of carbonaceous adsorbents for removal of hydrogen sulfide and nitrite ions from water. The role of the surface functional groups of carbonaceous adsorbents, their acid-basic properties, and the influence of the type of impregnated heteroatom (N, O, or metals (Fe, Cu, Ni, on removal of hydrogen sulfide species and nitrite ions have been researched. The efficiency of the catalyst obtained from peach stones by impregnation with Cu2+ ions of oxidized active carbon was established, being recommended for practical purposes to remove the hydrogen sulfide species from the sulfurous ground waters. Comparative analysis of carbonaceous adsorbents reveals the importance of surface chemistry for oxidation of nitrite ions.

Characterization of carbonaceous solids by oxygen chemisorption

Energy Technology Data Exchange (ETDEWEB)

Furimsky, E.; Palmer, A.; Duguay, D.G.; McConnell, D.G.; Henson, D.E.

1988-06-01

Oxygen chemisorption of high and low carbon carbonaceous solids was measured in an electro-microbalance at 200 degrees C in air. A linear correlation between the amount of chemisorbed oxygen and H/C ratio as well as aromaticity was established for the high carbon solids. For the low carbon solids a linear correlation was established between the amount of chemisorbed oxygen and the content of organic matter. Experimental observations are discussed in terms of structural aspects of the solids. Oxygen chemisorption is a suitable technique for a rapid characterization of carbonaceous solids including coal. 15 refs., 7 figs., 3 tabs.

The chemical structure of the insoluble organic matter from carbonaceous meteorites

Science.gov (United States)

Derenne, S.; Robert, F.

2008-09-01

Carbonaceous chondrites are the most primitive objects of the solar system. They contain substantial amounts of carbon (up to 3%), mostly occurring in macromolecular insoluble organic matter (IOM). This IOM is generally considered as a record of interstellar synthesis and may contain precursors of prebiotic molecules possibly deposited on earth by meteoritic bombardments. For these reasons, chondritic IOM has been raising interest for long and it is therefore of special interest to decipher its chemical structure. It is now well established that the chemical structure of this macromolecular material is based on aromatic moieties linked by short aliphatic chains and comprising substantial amounts of heteroatoms. However, its precise chemical structure could only be recently specified. The aim of this presentation is to propose a molecular model for the chemical structure of IOM isolated from non-metamorphosed carbonaceous chondrites. This model is derived from a large set of data obtained through a combination of techniques including various spectrocopies, high resolution transmission electron microscopy (HRTEM) and chemical and thermal degradations. Cosmochemical implications of such a structure will also be discussed.

Raman characterization of carbonaceous matter in CONCORDIA Antarctic micrometeorites

Science.gov (United States)

Dobricǎ, E.; Engrand, C.; Quirico, E.; Montagnac, G.; Duprat, J.

2011-09-01

Abstract- We report a multi-wavelength Raman spectroscopy study of carbonaceous matter in 38 Antarctic micrometeorites (AMMs) from the 2006 CONCORDIA collection. The particles were selected as a function of their degree of thermal alteration developed during the deceleration in the atmosphere. These samples range from unmelted (fine-grained—Fg; ultracarbonaceous—UCAMMs) to partially melted AMMs (scorias—Sc) and completely melted particles (cosmic spherules—CS). More than half of the analyzed AMMs contain a substantial amount of polyaromatic carbonaceous matter with a high degree of disorder. The proportion of particles where carbon is not detected increase from the Fg to the Fg-Sc and to the Sc-AMMs, and no carbon is detected in CS. In addition, the spectral characteristics of the G and D bands of the carbonaceous matter in Sc-AMMs plot apart from the trend formed by the data from Fg-AMMs and UCAMMs. These results suggest that oxidation processes occurred during the deceleration of the particles in the atmosphere. In Fg-AMMs and UCAMMs, the spectral characteristics of the G and D bands reveal the high degree of disorder of the carbonaceous matter, precluding a long duration thermal metamorphism on the parent body and suggesting that AMMs have a connection with C1-C2 chondrites. The Raman parameters of the deuterium-rich carbonaceous matter of UCAMMs do not differ from that of Fg-AMMs. Using a 244 nm excitation, we detected the cyanide (-CN) functional group for the first time in a UCAMM, reinforcing the likely cometary origin of this type of micrometeorites.

Sub-micrometer refractory carbonaceous particles in the polar stratosphere

Science.gov (United States)

Schütze, Katharina; Wilson, James Charles; Weinbruch, Stephan; Benker, Nathalie; Ebert, Martin; Günther, Gebhard; Weigel, Ralf; Borrmann, Stephan

2017-10-01

Eleven particle samples collected in the polar stratosphere during SOLVE (SAGE III Ozone loss and validation experiment) from January until March 2000 were characterized in detail by high-resolution transmission and scanning electron microscopy (TEM/SEM) combined with energy-dispersive X-ray microanalysis. A total of 4202 particles (TEM = 3872; SEM = 330) were analyzed from these samples, which were collected mostly inside the polar vortex in the altitude range between 17.3 and 19.9 km. Particles that were volatile in the microscope beams contained ammonium sulfates and hydrogen sulfates and dominated the samples. Some particles with diameters ranging from 20 to 830 nm were refractory in the electron beams. Carbonaceous particles containing additional elements to C and O comprised from 72 to 100 % of the refractory particles. The rest were internal mixtures of these materials with sulfates. The median number mixing ratio of the refractory particles, expressed in units of particles per milligram of air, was 1.1 (mg air)-1 and varied between 0.65 and 2.3 (mg air)-1. Most of the refractory carbonaceous particles are completely amorphous, a few of the particles are partly ordered with a graphene sheet separation distance of 0.37 ± 0.06 nm (mean value ± standard deviation). Carbon and oxygen are the only detected major elements with an atomic O/C ratio of 0.11 ± 0.07. Minor elements observed include Si, S, Fe, Cr and Ni with the following atomic ratios relative to C: Si/C: 0.010 ± 0.011; S/C: 0.0007 ± 0.0015; Fe/C: 0.0052 ± 0.0074; Cr/C: 0.0012 ± 0.0017; Ni/C: 0.0006 ± 0.0011 (all mean values ± standard deviation).High-resolution element distribution images reveal that the minor elements are distributed within the carbonaceous matrix; i.e., heterogeneous inclusions are not observed. No difference in size, nanostructure and elemental composition was found between particles collected inside and outside the polar vortex. Based on chemistry and nanostructure

Characterization of combustion-generated carbonaceous nanoparticles by size-dependent ultraviolet laser photoionization.

Science.gov (United States)

Commodo, Mario; Sgro, Lee Anne; Minutolo, Patrizia; D'Anna, Andrea

2013-05-16

Photoelectric charging of particles is a powerful tool for online characterization of submicrometer aerosol particles. Indeed photoionization based techniques have high sensitivity and chemical selectivity. Moreover, they yield information on electronic properties of the material and are sensitive to the state of the surface. In the present study the photoionization charging efficiency, i.e., the ratio between the generated positive ions and the corresponding neutral ones, for different classes of flame-generated carbonaceous nanoparticles was measured. The fifth harmonics of a Nd:YAG laser, 213 nm (5.82 eV), was used as an ionization source for the combustion generated nanoparticles, whereas a differential mobility analyzer (DMA) coupled to a Faraday cup electrometer was used for particle classification and detection. Carbonaceous nanoparticles in the nucleation mode, i.e., sizes ranging from 1 to 10 nm, show a photoionization charging efficiency clearly dependent on the flame conditions. In particular, we observed that the richer the flame is, i.e., the higher the equivalent ratio is, the higher the photon charging efficiency is. We hypothesized that such an increase in the photoionization propensity of the carbonaceous nanoparticles from richer flame condition is associated to the presence within the particles of larger aromatic moieties. The results clearly show that photoionization is a powerful diagnostic tool for the physical-chemical characterization of combustion aerosol, and it may lead to further insights into the soot formation mechanism.

Sub-micrometer refractory carbonaceous particles in the polar stratosphere

Directory of Open Access Journals (Sweden)

K. Schütze

2017-10-01

Full Text Available Eleven particle samples collected in the polar stratosphere during SOLVE (SAGE III Ozone loss and validation experiment from January until March 2000 were characterized in detail by high-resolution transmission and scanning electron microscopy (TEM/SEM combined with energy-dispersive X-ray microanalysis. A total of 4202 particles (TEM  =  3872; SEM  =  330 were analyzed from these samples, which were collected mostly inside the polar vortex in the altitude range between 17.3 and 19.9 km. Particles that were volatile in the microscope beams contained ammonium sulfates and hydrogen sulfates and dominated the samples. Some particles with diameters ranging from 20 to 830 nm were refractory in the electron beams. Carbonaceous particles containing additional elements to C and O comprised from 72 to 100 % of the refractory particles. The rest were internal mixtures of these materials with sulfates. The median number mixing ratio of the refractory particles, expressed in units of particles per milligram of air, was 1.1 (mg air−1 and varied between 0.65 and 2.3 (mg air−1. Most of the refractory carbonaceous particles are completely amorphous, a few of the particles are partly ordered with a graphene sheet separation distance of 0.37 ± 0.06 nm (mean value ± standard deviation. Carbon and oxygen are the only detected major elements with an atomic O∕C ratio of 0.11 ± 0.07. Minor elements observed include Si, S, Fe, Cr and Ni with the following atomic ratios relative to C: Si∕C: 0.010 ± 0.011; S∕C: 0.0007 ± 0.0015; Fe∕C: 0.0052 ± 0.0074; Cr∕C: 0.0012 ± 0.0017; Ni∕C: 0.0006 ± 0.0011 (all mean values ± standard deviation.High-resolution element distribution images reveal that the minor elements are distributed within the carbonaceous matrix; i.e., heterogeneous inclusions are not observed. No difference in size, nanostructure and elemental composition was found between

Comets, Carbonaceous Meteorites, and the Origin of the Biosphere

Science.gov (United States)

Hoover, Richard B.

2007-01-01

Evidence for indigenous microfossils in carbonaceous meteorites suggests that the paradigm of the endogenous origin of life on Earth should be reconsidered. It is now widely accepted that comets and carbonaceous meteorites played an important role in the delivery of water, organics and life critical biogenic elements to the early Earth and facilitated the origin and evolution of the Earth's Biosphere. However; the detection of embedded microfossils and mats in carbonaceous meteorites implies that comets and meteorites may have played a direct role in the delivery of intact microorganisms and that the Biosphere may extend far into the Cosmos. Recent space observations have found the nuclei of comets to have very low albedos (approx.0.03) and. these jet-black surfaces become very hot (T approx. 400 K) near perihelion. This paper reviews recent observational data-on comets and suggests that liquid water pools could exist in cavities and fissures between the internal ices and rocks and the exterior carbonaceous crust. The presence of light and liquid water near the surface of the nucleus enhances the possibility that comets could harbor prokaryotic extremophiles (e.g., cyanobacteria) capable of growth over a wide range of temperatures. The hypothesis that comets are the parent bodies of the CI1 and the CM2 carbonaceous meteorites is advanced. Electron microscopy images will be presented showing forms interpreted as indigenous-microfossils embedded' in freshly. fractured interior surfaces of the Orgueil (CI1) and Murchison (CM2) meteorites. These forms are consistent in size and morphologies with known morphotypes of all five orders of Cyanobacteriaceae: Energy Dispersive X-ray Spectroscopy (EDS) elemental data shows that the meteoritic forms have anomalous C/O; C/N; and C/S as compared with modern extremophiles and cyanobacteria. These images and spectral data indicate that the clearly biogenic and embedded remains cannot be interpreted as recent biological

The Insoluble Carbonaceous Material of CM Chondrites as Possible Source of Discrete Organics During the Asteroidal Aqueous Phase

Science.gov (United States)

Yabuta, H.; Williams, L.; Cody, G.; Pizzarello, S.

2005-01-01

The larger portion of the organic carbon in carbonaceous chondrites (CC) is present as a complex and heterogeneous macromolecular material that is insoluble in acids and most solvents (IOM). So far, it has been analyzed only as a whole by microscopy (TEM) and spectroscopy (IR, NMR, EPR), which have offered and overview of its chemical nature, bonding, and functional group composition. Chemical or pyrolytic decomposition has also been used in combination with GC-MS to identify individual compounds released by these processes. Their value in the recognition of the original IOM structure resides in the ability to properly interpret the decomposition pathways for any given process. We report here a preliminary study of IOM from the Murray meteorite that combines both the analytical approaches described above, under conditions that would realistically model the IOM hydrothermal exposure in the meteorite parent body. The aim is to document the possible release of water and solvent soluble organics, determine possible changes in NMR spectral features, and ascertain, by extension, the effect of this loss on the frame of the IOM residue. Additional information is included in the original extended abstract.

Carbonaceous aerosols over China--review of observations, emissions, and climate forcing.

Science.gov (United States)

Wang, Linpeng; Zhou, Xuehua; Ma, Yujie; Cao, Zhaoyu; Wu, Ruidong; Wang, Wenxing

2016-01-01

Carbonaceous aerosols have been attracting attention due to the influence on visibility, air quality, and regional climate. Statistical analyses based on concentration levels, spatial-temporal variations, correlations, and organic carbon (OC) to element carbon (EC) ratios from published data of OC and EC in particulate matter (PM2.5 and PM10) were carried out in order to give a carbonaceous aerosol profile in China. The results showed maxima for OC of 29.5 ± 18.2 μg C m(-3) and for EC of 8.4 ± 6.3 μg C m(-3) in winter and minima for OC of 12.9 ± 7.7 μg C m(-3) in summer and for EC of 4.6 ± 2.8 μg C m(-3) in spring. In addition, OC and EC both had higher concentrations in urban than those in rural sites. Carbonaceous aerosol levels in China are about three to seven times higher compared to those in the USA and Europe. OC and EC occupied 20 ± 6 and 7 ± 3% of PM2.5 mass and 17 ± 7 and 5 ± 3% of PM10 mass, respectively, implying that carbonaceous aerosols are the main component of PM, especially OC. Secondary organic carbon (SOC) was a significant portion of PM and contributed 41 ± 26% to OC and 8 ± 6% to PM2.5 mass. The OC/EC ratio was 3.63 ± 1.73, which, along with the good correlation between OC and EC and the OC to EC slope of 2.29, signifies that coal combustion and/or vehicular exhaust is the dominated carbonaceous aerosol source in China. These provide a primary observation-based understanding of carbonaceous aerosol pollution in China and have a great significance in improving the emission inventory and climate forcing evaluation.

Nature and origin of the resistant carbonaceous polymorphs involved the fossilization of biogenic soil-aggregates

Science.gov (United States)

Courty, M.-A.

2012-04-01

The rare occurrence of organic-rich surface horizons in soil archives is widely accepted to resulting from their rapid degradation. We intend here to further elucidate how pedogenic signatures that initially formed at the soil surface could resist over long timescales to burial processes. We focus on the structural evolution of the biogenic soil aggregates that is controlled by the complex interaction of bioturbation, root colonization, microbial decomposition, chemical weathering and physical processes. The nature and origin of carbonaceous components that could possibly contribute to the long term preservation of biogenic soil-aggregates is particularly examined. The study is based on the comparison of pedogenic aggregated microfacies from present-day situations and the ones encountered in soil archives from contrasting edaphic conditions: Arctic Holocene soils from Spitsbergen, hyper-arid soils from the Moche valley (Peru), Holocene semi-arid Mediterranean soils from Northern Syria, late Pleistocene paleosols from lake Mungo (South Wales Australia) and late Pleistocene paleosols from the Ardeche valley (France). The assemblage and composition of biogenic soil-aggregated horizons has been characterized under the binocular microscope and in thin sections. The basic components have been separated by water sieving. A typology of carbonaceous polymorphs and associated composite materials has been established under the binocular. They have been characterized by SEM-EDS, Raman spectrometry, X-ray diffraction and TEM. The comparative study shows that all the biogenic soil-aggregates from the soil archives contain a high amount of similar exotic components that contrast from the parent materials by their fresh aspect and their hydrophobic properties. This exotic assemblage comprises various types of aliphatic carbonaceous polymorphs (filaments, agglutinates, spherules) and aromatic ones (vitrous char, graphite), carbon cenospheres, fine grained sandstones and rock clasts

Carbonaceous species in atmospheric aerosols from the Krakow area (Malopolska District: carbonaceous species dry deposition analysis

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Szramowiat Katarzyna

2016-01-01

Full Text Available Organic and elemental carbon content in PM10 was studied at three sites in Malopolska District representing the city centre (Krakow, rural/residential (Bialka and residential/industrial environments (Krakow. The PM10 samples were collected during the winter time study. The highest concentrations of carbonaceous species were observed in Skawina (36.9 μg·m-3 of OC and 9.6 μg·m-3 of EC. The lowest OC and EC concentrations were reported in Krakow (15.2 μg·m-3 and 3.9 μg·m-3, respectively. The highest concentration of carbonaceous species and the highest wind velocities in Skawina influenced the highest values of the dry deposition fluxes. Correlations between OC, EC and chemical constituents and meteorological parameters suggest that a Krakow was influenced by local emission sources and temperature inversion occurrence; b Bialka was under the influence of local emission sources and long-range transport of particles; c Skawina was impacted by local emission sources.

Nanostructural Materials for Energy Storage Systems

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Bronislaw Buczek

2011-01-01

Full Text Available The aim of this study was to assess of carbonaceous monoliths used for adsorption cooling systems. The carbonaceous monoliths prepared from coal precursors are obtained. The porous structure of monoliths was evaluated on the basis of nitrogen adsorption-desorption data. The investigated monoliths have significantly developed microporous structure. The large specific area of carbonaceous monoliths (about 2000 m2/g and volume of micropores are observed. Methanol adsorption isotherms and heat of wetting using methanol was determined. Results show that monoliths materials are high adsorption capacity of methanol and heat of wetting, which can improve of heat exchange and efficiency in processes of refrigeration and air conditioning.

Ion Irradiation Experiments on the Murchison CM2 Carbonaceous Chondrite: Simulating Space Weathering of Primitive Asteroids

Science.gov (United States)

Keller, L. P.; Christoffersen, R.; Dukes, C. A.; Baragiola, R. A.; Rahman, Z.

2015-01-01

Remote sensing observations show that space weathering processes affect all airless bodies in the Solar System to some degree. Sample analyses and lab experiments provide insights into the chemical, spectroscopic and mineralogic effects of space weathering and aid in the interpretation of remote- sensing data. For example, analyses of particles returned from the S-type asteroid Itokawa by the Hayabusa mission revealed that space-weathering on that body was dominated by interactions with the solar wind acting on LL ordinary chondrite-like materials [1, 2]. Understanding and predicting how the surface regoliths of primitive carbonaceous asteroids respond to space weathering processes is important for future sample return missions (Hayabusa 2 and OSIRIS-REx) that are targeting objects of this type. Here, we report the results of our preliminary ion irradiation experiments on a hydrated carbonaceous chondrite with emphasis on microstructural and infrared spectral changes.

Microwave assisted synthesis of luminescent carbonaceous nanoparticles from silk fibroin for bioimaging.

Science.gov (United States)

Gao, Hongzhi; Teng, Choon Peng; Huang, Donghong; Xu, Wanqing; Zheng, Chaohui; Chen, Yisong; Liu, Minghuan; Yang, Da-Peng; Lin, Ming; Li, Zibiao; Ye, Enyi

2017-11-01

Bombyx mori silk as a natural protein based biopolymer with high nitrogen content, is abundant and sustainable because of its mass product all over the world per year. In this study, we developed a facile and fast microwave-assisted synthesis of luminescent carbonaceous nanoparticles using Bombyx mori silk fibroin and silk solution as the precursors. As a result, the obtained carbonaceous nanoparticles exhibit a photoluminescence quantum yield of ~20%, high stability, low cytotoxicity, high biocompatibility. Most importantly, we successfully demonstrated bioimaging using these luminescent carbonaceous nanoparticles with excitation dependent luminescence. In addition, the microwave-assisted hydrothermal method can be extended to convert other biomass into functional nanomaterials. Copyright © 2017 Elsevier B.V. All rights reserved.

Materials 2014: a great success for materials sector

International Nuclear Information System (INIS)

Isnard, Olivier; Crepin, Jerome

2014-01-01

In this work are presented the summaries of the 19 symposiums presented at the conference: 'Materials 2014' and whose topics were: eco-materials, materials for energy storage and conversion, strategic materials, rare elements and recycling, surfaces functionalization and physico-chemical characterization, interfaces and coatings, corrosion, aging, durability, damage mechanical behaviours, disordered materials, glasses and their functionalization, materials and health, functional materials, porous, granular and with a high surface area materials, nano-materials, nano-structured systems, assembling processes, carbonaceous materials, great instruments and studies of materials, materials in severe conditions, powder forming processes, metallic materials and structures lightening. (O.M.)

Carbonaceous Aerosols in Fine Particulate Matter of Santiago Metropolitan Area, Chile

Science.gov (United States)

Toro Araya, Richard; Flocchini, Robert; Morales Segura, Rául G. E.; Leiva Guzmán, Manuel A.

2014-01-01

Measurements of carbonaceous aerosols in South American cities are limited, and most existing data are of short term and limited to only a few locations. For 6 years (2002–2007), concentrations of fine particulate matter and organic and elemental carbon were measured continuously in the capital of Chile. The contribution of carbonaceous aerosols to the primary and secondary fractions was estimated at three different sampling sites and in the warm and cool seasons. The results demonstrate that there are significant differences in the levels in both the cold (March to August) and warm (September to February) seasons at all sites studied. The percent contribution of total carbonaceous aerosol fine particulate matter was greater in the cool season (53 ± 41%) than in the warm season (44 ± 18%). On average, the secondary organic carbon in the city corresponded to 29% of the total organic carbon. In cold periods, this proportion may reach an average of 38%. A comparison of the results with the air quality standards for fine particulate matter indicates that the total carbonaceous fraction alone exceeds the World Health Organization standard (10 µg/m3) and the United States Environmental Protection Agency standard (15 µg/m3) for fine particulate matter. PMID:24587753

Carbonaceous Aerosols in Fine Particulate Matter of Santiago Metropolitan Area, Chile

Directory of Open Access Journals (Sweden)

Richard Toro Araya

2014-01-01

Full Text Available Measurements of carbonaceous aerosols in South American cities are limited, and most existing data are of short term and limited to only a few locations. For 6 years (2002–2007, concentrations of fine particulate matter and organic and elemental carbon were measured continuously in the capital of Chile. The contribution of carbonaceous aerosols to the primary and secondary fractions was estimated at three different sampling sites and in the warm and cool seasons. The results demonstrate that there are significant differences in the levels in both the cold (March to August and warm (September to February seasons at all sites studied. The percent contribution of total carbonaceous aerosol fine particulate matter was greater in the cool season (53 ± 41% than in the warm season (44 ± 18%. On average, the secondary organic carbon in the city corresponded to 29% of the total organic carbon. In cold periods, this proportion may reach an average of 38%. A comparison of the results with the air quality standards for fine particulate matter indicates that the total carbonaceous fraction alone exceeds the World Health Organization standard (10 µg/m3 and the United States Environmental Protection Agency standard (15 µg/m3 for fine particulate matter.

Carbonaceous aerosols in fine particulate matter of Santiago Metropolitan Area, Chile.

Science.gov (United States)

Toro Araya, Richard; Flocchini, Robert; Morales Segura, Rául G E; Leiva Guzmán, Manuel A

2014-01-01

Measurements of carbonaceous aerosols in South American cities are limited, and most existing data are of short term and limited to only a few locations. For 6 years (2002-2007), concentrations of fine particulate matter and organic and elemental carbon were measured continuously in the capital of Chile. The contribution of carbonaceous aerosols to the primary and secondary fractions was estimated at three different sampling sites and in the warm and cool seasons. The results demonstrate that there are significant differences in the levels in both the cold (March to August) and warm (September to February) seasons at all sites studied. The percent contribution of total carbonaceous aerosol fine particulate matter was greater in the cool season (53 ± 41%) than in the warm season (44 ± 18%). On average, the secondary organic carbon in the city corresponded to 29% of the total organic carbon. In cold periods, this proportion may reach an average of 38%. A comparison of the results with the air quality standards for fine particulate matter indicates that the total carbonaceous fraction alone exceeds the World Health Organization standard (10 µg/m(3)) and the United States Environmental Protection Agency standard (15 µg/m(3)) for fine particulate matter.

Pulmonary exposure to carbonaceous nanomaterials and sperm quality

DEFF Research Database (Denmark)

Skovmand, Astrid; Lauvas, Anna Jacobsen; Christensen, Preben

2018-01-01

. Pulmonary inflammation was determined by differential cell count in bronchoalveolar lavage fluid. Epididymal sperm concentration and motility were measured by computer-assisted sperm analysis. Epididymal sperm viability and morphological abnormalities were assessed manually using Hoechst 33,342/PI...... inflammation is a potential modulator of endocrine function. The aim of this study was to investigate the effects of pulmonary exposure to carbonaceous nanomaterials on sperm quality parameters in an experimental mouse model.Methods: Effects on sperm quality after pulmonary inflammation induced by carbonaceous...... flourescent and Spermac staining, respectively. Epididymal sperm were assessed with regard to sperm DNA integrity (damage). Daily sperm production was measured in the testis, and testosterone levels were measured in blood plasma by ELISA.Results: Neutrophil numbers in the bronchoalveolar fluid showed...

AMMONIA IN THE EARLY SOLAR SYSTEM: AN ACCOUNT FROM CARBONACEOUS METEORITES

International Nuclear Information System (INIS)

Pizzarello, S.; Williams, L. B.

2012-01-01

This study presents a survey of abundance distribution and isotopic composition of the ammonia found incorporated in the kerogen-like insoluble material of selected carbonaceous chondrite meteorites; the ammonia was released upon hydrothermal treatment at 300°C and 100 MPa. With the exception of Allende, a metamorphosed and highly altered stone, all the insoluble organic materials (IOM) of the meteorites analyzed released significant amounts of ammonia, which varied from over 4 μg mg –1 for the Orgueil IOM to 0.5 μg mg –1 for that of Tagish Lake; the IOM of the pristine Antarctica find GRA95229 remains the most rich in freeable ammonia with 10 μg mg –1 . While the amounts of IOM bound ammonia do not appear to vary between meteorites with a recognizable trend, a possible consequence of long terrestrial exposure of some of the stones, we found that the δ 15 N composition of the ammonia-carrying materials is clearly distinctive of meteorite types and may reflect a preservation of the original 15 N distribution of pre- and proto-solar materials.

Ammonia in the Early Solar System: An Account from Carbonaceous Meteorites

Science.gov (United States)

Pizzarello, S.; Williams, L. B.

2012-04-01

This study presents a survey of abundance distribution and isotopic composition of the ammonia found incorporated in the kerogen-like insoluble material of selected carbonaceous chondrite meteorites; the ammonia was released upon hydrothermal treatment at 300°C and 100 MPa. With the exception of Allende, a metamorphosed and highly altered stone, all the insoluble organic materials (IOM) of the meteorites analyzed released significant amounts of ammonia, which varied from over 4 μg mg-1 for the Orgueil IOM to 0.5 μg mg-1 for that of Tagish Lake; the IOM of the pristine Antarctica find GRA95229 remains the most rich in freeable ammonia with 10 μg mg-1. While the amounts of IOM bound ammonia do not appear to vary between meteorites with a recognizable trend, a possible consequence of long terrestrial exposure of some of the stones, we found that the δ15N composition of the ammonia-carrying materials is clearly distinctive of meteorite types and may reflect a preservation of the original 15N distribution of pre- and proto-solar materials.

Method of pyrolytic decomposition and coking of a mixture of finely distributed solid or semisolid carbonaceous material and hydrocarbon oils

Energy Technology Data Exchange (ETDEWEB)

1933-09-09

A method of pyrolytic decomposition and coking of a mixture of finely distributed of solid or semi-solid carbonaceous material and hydrocarbon oils is disclosed whereby the mixture is exposed to a decomposition temperature and later is brought into the zone of decomposition where vapors are separated from the unvaporized residue and the vapors are exposed to fractional condensation for the purpose of obtaining a light product of distillation. The method is characterized by the mixture being exposed to heating by means of indirect exchange of heat in a heating zone or by means of a direct addition of a hot heat-conducting medium, or by means of both the mentioned indirect exchange of heat and direct heat under such conditions that the unvaporized residue obtained from the thus-heated mixture in the decomposition zone is transformed to solid coke in this zone by being heated to coking temperature in a comparatively thin layer on the surface of the decomposition zone that has been heated to a high temperature.

A New Method of Absorption-Phase Nanotomography for 3D Observation of Mineral-Organic-Water Textiles and its Application to Pristine Carbonaceous Chondrites

Science.gov (United States)

Tsuchiyama, A.; Nakato, A.; Matsuno, J.; Sugimoto, M.; Uesugi, K.; Takeuchi, A.; Nakano, T.; Vaccaro, E.; Russel, S.; Nakamura-Messenger, K.;

Radiocarbon: nature's tracer for carbonaceous pollutants

International Nuclear Information System (INIS)

Currie, L.A.; Klouda, G.A.; Gerlach, R.W.

1982-01-01

Recent developments in radiocarbon dating techniques have made it feasible to determine 14 C/ 12 C ratios in samples containing milligram or even microgram quantities of carbon. As a result, it has become practicable to apply these techniques to the study of trace gases and particles in the atmosphere, as a means of resolving anthropogenic from natural source components. Interpretation of 14 C data is straightforward: biospheric carbon (such as vegetation) is alive with a 14 C/ 12 C ratio of about 1.5 x 10 -12 , whereas fossil carbon is dead. Beyond this dichotomous classification it becomes very interesting to combine the isotopic data with concurrent chemical data, as well as spatial and temporal distributions, in order to infer the strengths of specific sources of carbonaceous pollutants. A brief review will be presented of our program on atmospheric gases and carbonaceous particles. For the latter, we have assayed individual chemical and size fractions, and samples collected in urban, rural, and remote locales. The biogenic carbon fraction - presumably from wood-burning - ranged from 10% to 100% for the urban samples analyzed

Fungal-Transformation of Surrogate Sulphides and Carbonaceous ...

African Journals Online (AJOL)

In the recovery of gold from refractory gold ores, pretreatment is required to decompose sulphides and liberate occluded gold before cyanidation, and to deactivate carbonaceous matter and prevent it from adsorbing dissolved gold. Until the past three decades, most commercial pretreatment processes had been by abiotic ...

Carbonaceous Asteroid Volatile Recovery (CAVoR) system, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The Carbonaceous Asteroid Volatile Recovery (CAVoR) system produces water and hydrogen-rich syngas for propellant production, life support consumables, and...

The carbonaceous phyllite rock-hosted Pedra Verde copper mine, Borborema Province, Brazil: Stable isotope constraints, structural controls and metallogenic evolution

Science.gov (United States)

da Silva Nogueira de Matos, José Henrique; Saraiva dos Santos, Ticiano José; Virgínia Soares Monteiro, Lena

2017-12-01

The Pedra Verde Copper Mine is located in the Viçosa do Ceará municipality, State of Ceará, NE Brazil. The copper mineralization is hosted by the Pedra Verde Phyllite, which is a carbonaceous chlorite-calcite phyllite with subordinate biotite. It belongs to the Neoproterozoic Martinópole Group of the Médio Coreaú Domain, Borborema Province. The Pedra Verde deposit is stratabound and its ore zoning is conspicuous, according to the following sequence, from bottom to top: marcasite/pyrite, native silver, chalcopyrite, bornite, chalcocite, native copper and hematite. Barite and carbonaceous material are reported in ore zones. Zoning reflects the ore formation within a redox boundary developed due to the interaction between oxidized copper- and sulfate-bearing fluids and the reduced phyllite. Structural control on mineralization is evidenced by the association of the ore minerals with veins, hinge folds, shadow pressures, and mylonitic foliation. It was mainly exercised by a dextral transcurrent shear zone developed during the third deformational stage identified in the Médio Coreaú Domain between 590 Ma and 570 Ma. This points to the importance of epigenetic, post-metamorphic deformational events for ore formation. Oxygen isotopic composition (δ18OH2O = 8.94 to 11.28‰, at 250 to 300 °C) estimated for the hydrothermal fluids in equilibrium with calcite indicates metamorphic or evolved meteoric isotopic signatures. The δ13CPDB values (-2.60 to -9.25‰) obtained for hydrothermal calcite indicate mixing of carbon sources derived from marine carbonate rocks and carbonaceous material. The δ34SCDT values (14.88 to 36.91‰) of sulfides suggest evaporites as sulfate sources or a closed system in relation to SO42- availability to form H2S. Carbonaceous matter had a key role in thermochemical sulfate processes and sulfide precipitation. The Pedra Verde Copper Mine is considered the first stratabound meta-sedimentary rock-hosted copper deposit described in Brazil

Carbonaceous Aerosol Characterization during 2016 KOR-US 2016

Science.gov (United States)

Rodriguez, B.; Santos, G. M.; Sanchez, D.; Jeong, D.; Czimczik, C. I.; Kim, S.

2017-12-01

Atmospheric carbonaceous aerosols are a major component of fine particulate matter and assume important roles in Earth's climate and human health. Because atmospheric carbonaceous aerosols exist as a continuum ranging from small, light-scattering organic carbon (OC), to highly-condensed, light-absorbing elemental carbon (EC) they have contrasting effects on interaction with incoming and outgoing radiation, cloud formation, and snow/ice albedo. By strengthening our understanding of the relative contribution and sources of OC and EC we will be able to further describe aerosol formation and mixing at the regional level. To understand the relative anthropogenic and biogenic contributions to carbonaceous aerosol, 12 PM10 aerosols samples were collected on quartz fiber filters at the Mt. Taewha Research Forest in South Korea during the KORUS-AQ 2016 campaign over periods of 24-48 hours with a high-volume air sampler. Analysis of bulk C and N concentrations and absorption properties of filter extracts interspersed with HYSPLIT model results indicated that continental outflow across the Yellow Sea in enriched in bulk nitrogen loading and enhanced bulk absorptive properties of the aerosols. Bulk radiocarbon analysis also indicated enriched values in all samples indicating contamination from a nuclear power plant or the combustion of biomedical waste nearby. Here, we aim to investigate further the chemical characterization of VOCs adsorbed unto the aerosol through TD-GC-TOFMS. With this dataset we aim to determine the relative contribution of anthropogenic and biogenic aerosols by utilizing specific chemical tracers for source apportionment.

Tunable atomic force microscopy bias lithography on electron beam induced carbonaceous platforms

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Narendra Kurra

2013-09-01

Full Text Available Tunable local electrochemical and physical modifications on the carbonaceous platforms are achieved using Atomic force microscope (AFM bias lithography. These carbonaceous platforms are produced on Si substrate by the technique called electron beam induced carbonaceous deposition (EBICD. EBICD is composed of functionalized carbon species, confirmed through X-ray photoelectron spectroscopy (XPS analysis. AFM bias lithography in tapping mode with a positive tip bias resulted in the nucleation of attoliter water on the EBICD surface under moderate humidity conditions (45%. While the lithography in the contact mode with a negative tip bias caused the electrochemical modifications such as anodic oxidation and etching of the EBICD under moderate (45% and higher (60% humidity conditions respectively. Finally, reversible charge patterns are created on these EBICD surfaces under low (30% humidity conditions and investigated by means of electrostatic force microscopy (EFM.

A Case for Nebula Scale Mixing Between Non-Carbonaceous and Carbonaceous Chondrite Reservoirs: Testing the Grand Tack Model with Chromium Isotopic Composition of Almahata Sitta Stone 91A

Science.gov (United States)

Sanborn, M. E.; Yin, Q.-Z.; Goodrich, C. A.; Zolensky, M.; Fioretti, A. M.

2017-01-01

There is an increasing number of Cr-O-Ti isotope studies that show solar system materials are divided into two main populations, one carbonaceous chondrite (CC)-like and the other is non-carbonaceous (NC)-like, with minimal mixing attributed to a gap opened in the protoplanetary disk due to Jupiter's formation. The Grand Tack model suggests there should be large-scale mixing between S- and C-type asteroids, an idea supported by our recent work on chondrule (Delta)17O-e54Cr isotope systematics. The Almahata Sitta (AhS) meteorite provides a unique opportunity to test the Grand Tack model. The meteorite fell to Earth in October 2008 and has been linked to the asteroid 2008 TC3 which was discovered just prior to the fall of the AhS stones. The AhS meteorite is composed of up to 700 individual pieces with approx.140 of those pieces having some geochemical and/or petrologic studies. Almahata Sitta is an anomalous polymict ureilite with other meteorite components, including enstatite, ordinary, and carbonaceous chondrites with an approximate abundance of 70% ureilites and 30% chondrites. This observation has lead to the suggestion that TC3 2008 was a loosely aggregated rubble pile-like asteroid with the non-ureilite sample clasts within the rubble-pile. Due to the loosely-aggregated nature of AhS, the object disintegrated during atmospheric entry resulting in the weakly held clasts falling predominantly as individual stones in the AhS collection area. However, recent work has identified one sample of AhS, sample 91A, which may represent two different lithologies coexisting within a single stone. The predominate lithology type in 91A appears to be that of a C2 chondrite based on mineralogy but also contains olivine, pyroxene, and albite that have ureilite-like compositions. Previous Cr isotope investigations into AhS stones are sparse and what data is available show nearly uniform isotopic composition similar to that of typical ureilites with negative e54Cr values.

Carbonaceous aerosols in Norwegian urban areas

Directory of Open Access Journals (Sweden)

K. E. Yttri

2009-03-01

Full Text Available Little is known regarding levels and source strength of carbonaceous aerosols in Scandinavia. In the present study, ambient aerosol (PM₁₀ and PM_2.5 concentrations of elemental carbon (EC, organic carbon (OC, water-insoluble organic carbon (WINSOC, and water-soluble organic carbon (WSOC are reported for a curbside site, an urban background site, and a suburban site in Norway in order to investigate their spatial and seasonal variations. Aerosol filter samples were collected using tandem filter sampling to correct for the positive sampling artefact introduced by volatile and semivolatile OC. Analyses were performed using the thermal optical transmission (TOT instrument from Sunset Lab Inc., which corrects for charring during analysis. Finally, we estimated the relative contribution of OC from wood burning based on the samples content of levoglucosan.

Levels of EC varied by more than one order of magnitude between sites, likely due to the higher impact of vehicular traffic at the curbside and the urban background sites. In winter, the level of particulate organic carbon (OC_p at the suburban site was equal to (for PM₁₀ or even higher (for PM_2.5 than the levels observed at the curbside and the urban background sites. This finding was attributed to the impact of residential wood burning at the suburban site in winter, which was confirmed by a high mean concentration of levoglucosan (407 ng m⁻³. This finding indicates that exposure to primary combustion derived OC_p could be equally high in residential areas as in a city center. It is demonstrated that OC_p from wood burning (OC_wood accounted for almost all OC_p at the suburban site in winter, allowing a new estimate of the ratio TC_p/levoglucosan for both PM₁₀ and PM_2.5. Particulate carbonaceous material (PCM

Cloud albedo increase from carbonaceous aerosol

Directory of Open Access Journals (Sweden)

W. R. Leaitch

2010-08-01

Full Text Available Airborne measurements from two consecutive days, analysed with the aid of an aerosol-adiabatic cloud parcel model, are used to study the effect of carbonaceous aerosol particles on the reflectivity of sunlight by water clouds. The measurements, including aerosol chemistry, aerosol microphysics, cloud microphysics, cloud gust velocities and cloud light extinction, were made below, in and above stratocumulus over the northwest Atlantic Ocean. On the first day, the history of the below-cloud fine particle aerosol was marine and the fine particle sulphate and organic carbon mass concentrations measured at cloud base were 2.4 μg m⁻³ and 0.9 μg m⁻³ respectively. On the second day, the below-cloud aerosol was continentally influenced and the fine particle sulphate and organic carbon mass concentrations were 2.3 μg m⁻³ and 2.6 μg m⁻³ respectively. Over the range 0.06–0.8 μm diameter, the shapes of the below-cloud size distributions were similar on both days and the number concentrations were approximately a factor of two higher on the second day. The cloud droplet number concentrations (CDNC on the second day were approximately three times higher than the CDNC measured on the first day. Using the parcel model to separate the influence of the differences in gust velocities, we estimate from the vertically integrated cloud light scattering measurements a 6% increase in the cloud albedo principally due to the increase in the carbonaceous components on the second day. Assuming no additional absorption by this aerosol, a 6% albedo increase translates to a local daytime radiative cooling of ∼12 W m⁻². This result provides observational evidence that the role of anthropogenic carbonaceous components in the cloud albedo effect can be much larger than that of anthropogenic sulphate, as some global simulations have indicated.

Gasoline cars produce more carbonaceous particulate matter than modern filter-equipped diesel cars.

Science.gov (United States)

Platt, S M; El Haddad, I; Pieber, S M; Zardini, A A; Suarez-Bertoa, R; Clairotte, M; Daellenbach, K R; Huang, R-J; Slowik, J G; Hellebust, S; Temime-Roussel, B; Marchand, N; de Gouw, J; Jimenez, J L; Hayes, P L; Robinson, A L; Baltensperger, U; Astorga, C; Prévôt, A S H

2017-07-13

Carbonaceous particulate matter (PM), comprising black carbon (BC), primary organic aerosol (POA) and secondary organic aerosol (SOA, from atmospheric aging of precursors), is a highly toxic vehicle exhaust component. Therefore, understanding vehicle pollution requires knowledge of both primary emissions, and how these emissions age in the atmosphere. We provide a systematic examination of carbonaceous PM emissions and parameterisation of SOA formation from modern diesel and gasoline cars at different temperatures (22, -7 °C) during controlled laboratory experiments. Carbonaceous PM emission and SOA formation is markedly higher from gasoline than diesel particle filter (DPF) and catalyst-equipped diesel cars, more so at -7 °C, contrasting with nitrogen oxides (NO X ). Higher SOA formation from gasoline cars and primary emission reductions for diesels implies gasoline cars will increasingly dominate vehicular total carbonaceous PM, though older non-DPF-equipped diesels will continue to dominate the primary fraction for some time. Supported by state-of-the-art source apportionment of ambient fossil fuel derived PM, our results show that whether gasoline or diesel cars are more polluting depends on the pollutant in question, i.e. that diesel cars are not necessarily worse polluters than gasoline cars.

AMMONIA IN THE EARLY SOLAR SYSTEM: AN ACCOUNT FROM CARBONACEOUS METEORITES

Energy Technology Data Exchange (ETDEWEB)

Pizzarello, S. [Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287-1604 (United States); Williams, L. B., E-mail: pizzar@asu.edu [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287-1404 (United States)

2012-04-20

This study presents a survey of abundance distribution and isotopic composition of the ammonia found incorporated in the kerogen-like insoluble material of selected carbonaceous chondrite meteorites; the ammonia was released upon hydrothermal treatment at 300 Degree-Sign C and 100 MPa. With the exception of Allende, a metamorphosed and highly altered stone, all the insoluble organic materials (IOM) of the meteorites analyzed released significant amounts of ammonia, which varied from over 4 {mu}g mg{sup -1} for the Orgueil IOM to 0.5 {mu}g mg{sup -1} for that of Tagish Lake; the IOM of the pristine Antarctica find GRA95229 remains the most rich in freeable ammonia with 10 {mu}g mg{sup -1}. While the amounts of IOM bound ammonia do not appear to vary between meteorites with a recognizable trend, a possible consequence of long terrestrial exposure of some of the stones, we found that the {delta}{sup 15}N composition of the ammonia-carrying materials is clearly distinctive of meteorite types and may reflect a preservation of the original {sup 15}N distribution of pre- and proto-solar materials.

Quenched carbonaceous composite (QCC): a likely candidate for interstellar grains

International Nuclear Information System (INIS)

Sakata, A.; Wada, S.; Tanabe, T.; Onaka, T.

1984-01-01

The authors have recently reported that a carbonaceous composite synthesized from a hydrocarbon plasma shows an extinction property quite resembling the observed average interstellar extinction curve around the 220 nm hump. This composite is synthesized by quenching the excited gas ejecting from a plasma of methane gas, so it is called 'quenched carbonaceous composite' or 'QCC'. A recent study of QCC in the infrared region has shown that QCC can also account for some of the unidentified bands in the infrared region detected in several celestial objects. These results suggest that most of the pronounced features of the interstellar grains originate from substances whose major constituent is carbon. (author)

Carbonaceous aerosol at two rural locations in New York State: Characterization and behavior

Science.gov (United States)

Sunder Raman, Ramya; Hopke, Philip K.; Holsen, Thomas M.

2008-06-01

Fine particle samples were collected to determine the chemical constituents in PM2.5 at two rural background sites (Potsdam and Stockton, N. Y.) in the northeastern United States from November 2002 to August 2005. Samples were collected every third day for 24 h with a speciation network sampler. The measured carbonaceous species included thermal-optical organic carbon (OC), elemental carbon (EC), pyrolytic carbon (OP), black carbon (BC), and water-soluble, short-chain (WSSC) organic acids. Concentration time series, autocorrelations, and seasonal variations of the carbonaceous species were examined. During this multiyear period, the contributions of the total carbon (OC + EC) to the measured fine particle mass were 31.2% and 31.1% at Potsdam and Stockton, respectively. The average sum of the WSSC acids carbon accounted for approximately 2.5% of the organic carbon at Potsdam and 3.0% at Stockton. At Potsdam, the seasonal differences in the autocorrelation function (ACF) and partial autocorrelation function (PACF) values for carbonaceous species suggest that secondary formation may be an important contributor to the observed concentrations of species likely to be secondary in origin, particularly during the photochemically active time of the year (May to October). This study also investigated the relationships between carbonaceous species to better understand the behavior of carbonaceous aerosol and to assess the contribution of secondary organic carbon (SOC) to the total organic carbon mass (the EC tracer method was used to estimate SOC). At Potsdam the average SOC contribution to total OC varied between 66% and 72%, while at Stockton it varied between 58% and 64%.

Porous nitrogen-enriched carbonaceous material from marine waste: chitosan-derived layered CNX catalyst for aerial oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid

Data.gov (United States)

U.S. Environmental Protection Agency — Chitosan-derived, porous and layered nitrogen-enriched carbonaceous CNx catalyst (PLCNx) has been synthesized from marine waste and its use demonstrated in a...

Sorption characteristics and mechanisms of organic contaminant to carbonaceous biosorbents in aqueous solution

Institute of Scientific and Technical Information of China (English)

2008-01-01

A series of carbonaceous biosorbents was prepared by pyrolyzing pine needles,a model biomass,at various temperatures (100-700℃) under an oxygen-limited condition for 6h. The elemental composi-tions and the specific surface areas (BET-N2) of the biosorbents were analyzed. Sorption properties of 4-nitrotoluene to the biosorbents and their mechanisms were investigated,and then correlated with the structures of the biosorbents. The result shows that with the increase of the pyrolytic temperature,the aromaticity of the carbonaceous biosorbents increases dramatically and the polarity (the (N+O)/C atomic ratio) decreases sharply. Correspondingly,conformations of the organic matter in the biosor-bents transform gradually from a "soft-state" to a "hard-state" and the specific surface areas of the resultant biosorbents extend rapidly. The sorption isotherms fit well with the Freundlich equation. The regression parameters (i.e.,N and lgKf) are linearly related to the aromaticity indices (the H/C atomic ratio). Contributions of adsorption and partition to total sorption of the carbonaceous biosorbents are quantified. The adsorption of the carbonaceous biosorbents increases quickly with the increase of the pyrolytic temperature. The saturated adsorption amounts (Qmax) increase linearly with the increase of the specific surface areas (SA) of the biosorbents. For the carbonaceous biosorbents with hard-state carbon,the calculated normalized-Qmax values by SA are comparable to the theoretical estimation (2.45 μmol/m2). In comparison,for the carbonaceous sorbents with soft-state carbon,the calculated nor-malized-Qmax values by SA are much higher than the theoretical estimation. The partition coefficients (Kom) increase with the decrease of the polarity of the biosorbents,reaching a maximum,and then de-crease sharply with further decreasing the polarity,suggesting that partition mechanism be dominated by the compatibility and accessibility of the sorbent medium with organic

Sorption characteristics and mechanisms of organic contaminant to carbonaceous biosorbents in aqueous solution

Institute of Scientific and Technical Information of China (English)

CHEN BaoLiang; ZHOU DanDan; ZHU LiZhong; SHEN XueYou

2008-01-01

A series of carbonaceous biosorbents was prepared by pyrolyzing pine needles, a model biomass, at various temperatures (100-700℃) under an oxygen-limited condition for 6 h. The elemental composi-tions and the specific surface areas (BET-N2) of the biosorbents were analyzed. Sorption properties of 4-nitrotoluene to the biosorbents and their mechanisms were investigated, and then correlated with the structures of the biosorbents. The result shows that with the increase of the pyrolytic temperature, the sromaticity of the carbonaceous biosorbents increases dramatically and the polarity (the (N+O)/C atomic ratio) decreases sharply. Correspondingly, conformations of the organic matter in the biosor-bents transform gradually from a "soft-state" to a "hard-state" and the specific surface areas of the resultant biosorbents extend rapidly. The sorption isotherms fit well with the Freundlich equation. The regression parameters (I.e., N and IgKf) are linearly related to the aromaticity indices (the H/C atomic ratio). Contributions of adsorption and partition to total sorption of the carbonaceous biosorbents are quantified. The adsorption of the carbonaceous biosorbents increases quickly with the increase of the pyrolytic temperature. The saturated adsorption amounts (Qmax) increase linearly with the increase of the specific surface areas (SA) of the biosorbents. For the carbonaceous biosorbents with hard-state carbon, the calculated normalized-Qmax values by SA are comparable to the theoretical estimation (2.45 μmol/m2). In comparison, for the carbonaceous sorbents with soft-state carbon, the calculated nor-malized-Qmax values by SA are much higher than the theoretical estimation. The partition coefficients (Kom) increase with the decrease of the polarity of the biosorbents, reaching a maximum, and then de-crease sharply with further decreasing the polarity, suggesting that partition mechanism be dominated by the compatibility and accessibility of the sorbent medium with

Ore-forming environment and ore-forming system of carbonaceous-siliceous-pelitic rock type uranium deposit in China

International Nuclear Information System (INIS)

Qi Fucheng; Zhang Zilong; Li Zhixing; He Zhongbo; Wang Wenquan

2012-01-01

It is proposed that there are four types of ore-forming systems about carbonaceous-siliceous-pelitic rock type uranium deposit in China based on systematic study on structural environment and distribution regularity of uraniferous construction of marine carbonaceous-siliceous-pelitic rock in China: continental margin rift valley ore-forming systems, continental margin rifting deep fracture zone ore-forming systems, landmass boundary borderland basin ore-forming systems and epicontinental mobile belt downfaulted aulacogen ore-forming systems. It is propounded definitely that it is controlled by margin rift valley ore-forming systems and continental margin rifting deep fracture zone ore-forming systems for large-scale uranium mineralization of carbonaceous-siliceous-pelitic rock type uranium deposit in China, which is also controlled by uraniferous marine carbonaceous-siliceous-pelitic rock construction made up of silicalite, siliceous phosphorite and carbonaceous-siliceous-pelitic rock, which settled down accompany with submarine backwash and sub marine volcanic eruption in margin rift valley and continental margin rifting mineralizing environment. Continental mar gin rift valley and continental margin rifting thermal sedimentation or exhalation sedimentation is the mechanism of forming large-scale uraniferous marine carbonaceous-siliceous-pelitic rock construction Early Palaeozoic Era in China or large-scale uranium-polymetallic mineralization. (authors)

Sorption/desorption reversibility of polycyclic aromatic hydrocarbons (PAHs) in soils and carbonaceous materials

Energy Technology Data Exchange (ETDEWEB)

Wang, Guohui

2008-07-01

the determination of the sorption/desorption enthalpies which gives insight into the sorbent-sorbate interactions. In order to attain sorption/desorption equilibrium, all the samples were pulverized to shorten the laboratory experimental time. The sorbate losses were carefully monitored and considered in the isotherm calculation. Additionally, release of native phenanthrene was also investigated at different temperatures and compared with the freshly spiked samples to investigate the aging effect. The batch results show that for all individual temperature steps sorption and desorption isotherms coincide. Furthermore, the solubility-normalized sorption/desorption isotherms at different temperatures collapse to unique overall isotherms. Leaching of native phenanthrene occurred at much lower concentrations but was well predicted by extrapolation of the spiked equilibrium sorption isotherms. The absolute values of sorption/desorption isosteric heats ({delta}H) determined are in a range of 19 - 35 kJ mol{sup -1}, which is higher than the heat of aqueous solution of subcooled phenanthrene but much less than the heat of condensation of solid phenanthrene from water. No significant difference of the enthalpies between sorption and desorption was observed. Furthermore, the desorption enthalpy of the native phenanthrene was not significantly higher than expected from the sorption experiments with spiked samples. Sorption and desorption kinetics were monitored in on-line column experiments with stepwise increases of temperature. An intraparticle diffusion model was used to simulate the desorption profile in order to get the apparent diffusion coefficients of phenanthrene from the carbonaceous materials. Desorption activation energies were calculated by Arrhenius relationship based on the high-resolution measurement of concentration increases at each temperature step. The activation energies determined range from 58 - 71 kJ mol{sup -1}. No significant trend of increasing

Sorption/desorption reversibility of polycyclic aromatic hydrocarbons (PAHs) in soils and carbonaceous materials

Energy Technology Data Exchange (ETDEWEB)

Wang, Guohui

2008-07-01

determination of the sorption/desorption enthalpies which gives insight into the sorbent-sorbate interactions. In order to attain sorption/desorption equilibrium, all the samples were pulverized to shorten the laboratory experimental time. The sorbate losses were carefully monitored and considered in the isotherm calculation. Additionally, release of native phenanthrene was also investigated at different temperatures and compared with the freshly spiked samples to investigate the aging effect. The batch results show that for all individual temperature steps sorption and desorption isotherms coincide. Furthermore, the solubility-normalized sorption/desorption isotherms at different temperatures collapse to unique overall isotherms. Leaching of native phenanthrene occurred at much lower concentrations but was well predicted by extrapolation of the spiked equilibrium sorption isotherms. The absolute values of sorption/desorption isosteric heats ({delta}H) determined are in a range of 19 - 35 kJ mol{sup -1}, which is higher than the heat of aqueous solution of subcooled phenanthrene but much less than the heat of condensation of solid phenanthrene from water. No significant difference of the enthalpies between sorption and desorption was observed. Furthermore, the desorption enthalpy of the native phenanthrene was not significantly higher than expected from the sorption experiments with spiked samples. Sorption and desorption kinetics were monitored in on-line column experiments with stepwise increases of temperature. An intraparticle diffusion model was used to simulate the desorption profile in order to get the apparent diffusion coefficients of phenanthrene from the carbonaceous materials. Desorption activation energies were calculated by Arrhenius relationship based on the high-resolution measurement of concentration increases at each temperature step. The activation energies determined range from 58 - 71 kJ mol{sup -1}. No significant trend of increasing desorption activation

Effects of chemical functional groups on elemental mercury adsorption on carbonaceous surfaces

Energy Technology Data Exchange (ETDEWEB)

Liu Jing, E-mail: liujing27@mail.hust.edu.cn [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074 (China); Cheney, Marcos A. [Department of Natural Sciences, University of Maryland Eastern Shore, Princess Anne, MD 21853 (United States); Wu Fan; Li Meng [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074 (China)

2011-02-15

A systematic theoretical study using density functional theory is performed to provide molecular-level understanding of the effects of chemical functional groups on mercury adsorption on carbonaceous surfaces. The zigzag and armchair edges were used in modeling the carbonaceous surfaces to simulate different adsorption sites. The edge atoms on the upper side of the models are unsaturated to simulate active sites. All calculations (optimizations, energies, and frequencies) were made at B3PW91 density functional theory level, using RCEP60VDZ basis set for mercury and 6-31G(d) pople basis set for other atoms. The results indicate that the embedding of halogen atom can increase the activity of its neighboring site which in turn increases the adsorption capacity of the carbonaceous surface for Hg{sup 0}. The adsorption belongs to chemisorptions, which is in good agreement with the experimental results. For the effects of oxygen functional groups, lactone, carbonyl and semiquinone favor Hg{sup 0} adsorption because they increase the neighboring site's activity for mercury adsorption. On the contrary, phenol and carboxyl functional groups show a physisorption of Hg{sup 0}, and reduce Hg capture. This result can explain the seemingly conflicting experimental results reported in the literature concerning the influence of oxygen functional groups on mercury adsorption on carbonaceous surface.

Proto-Planetary Disk Chemistry Recorded by D-Rich Organic Radicals in Carbonaceous Chondrites

OpenAIRE

Remusat, Laurent; Robert, François; Meibom, Anders; Mostefaoui, Smail; Delpoux, Olivier; Binet, Laurent; Gourier, Didier; Derenne, Sylvie

2009-01-01

Insoluble organic matter (IOM) in primitive carbonaceous meteorites has preserved its chemical composition and isotopic heterogeneity since the solar system formed ~4.567 billion years ago. We have identified the carrier moieties of isotopically anomalous hydrogen in IOM isolated from the Orgueil carbonaceous chondrite. Data from high spatial resolution, quantitative isotopic NanoSIMS mapping of Orgueil IOM combined with data from electron paramagnetic resonance spectroscopy reveals that orga...

A Mudball Model for the Evolution of Carbonaceous Asteroids

Science.gov (United States)

Travis, B. J.; Bland, P. A.

2018-05-01

We simulation the evolution of carbonaceous chondrite parent bodies from initially unconsolidated aggregations of rock grains and ice crystals. Application of the numerical model MAGHNUM to evolution of CM type planetesimals and Ceres is described.

On radiogenic nature of xenon-X in carbonaceous and LL chondrites

International Nuclear Information System (INIS)

Gerling, Eh.K.

1982-01-01

The nature of Xe-X from the mineral fraction produced during the differential dissolution of carbonaceous and LL chondrites was investigated using literature data on the age of some meteorites and their fractions and quantities of fission 136 Xe contained in them. A graph of lg fission 136 Xe against the age of meteorites was plotted; the decay constant of a hypothetical superheavy nucleus was calculated using the graph and equaled 1x10 - 7 year - 1 . The calculations served as a forcible argument for the radiogenic nature of xenon with 136 and 134 mass in carbonaceous and LL chondrites

Process of treating carbonaceous substances

Energy Technology Data Exchange (ETDEWEB)

1938-12-16

A process is described of removing halogens or halogen compounds (or both) from the products which form when carbonaceous substances are treated thermally in the presence of halogens or halogen compounds, consisting of passing the reaction products at the same temperature with a substance able to fix halogens or acid halides through an apparatus included between the receiver and the heat exchanger, which contains, in a relatively restricted space, internal elements obliquely disposed in relation to the direction of the flow, stretched in this direction and constituted preferably of helicoidal passages.

Fe and O EELS Studies of Ion Irradiated Murchison CM2 Carbonaceous Chondrite Matrix

Science.gov (United States)

Keller, L. P.; Christofferson, R.; Dukes, C. A.; Baragiola, R. A.; Rahman, Z.

2015-01-01

Introduction: The physical and chemical response of hydrated carbonaceous chondrite materials to space weathering processes is poorly understood. Improving this understanding is a key part of establishing how regoliths on primitive carbonaceous asteroids respond to space weathering processes, knowledge that supports future sample return missions (Hayabusa 2 and OSIRISREx) that are targeting objects of this type. We previously reported on He+ irradiation of Murchison matrix and showed that the irradiation resulted in amorphization of the matrix phyllosilicates, loss of OH, and surface vesiculation. Here, we report electron energy-loss spectroscopy (EELS) measurements of the irradiated material with emphasis on the Fe and O speciation. Sample and Methods: A polished thin section of the Murchison CM2 carbonaceous chondrite was irradiated with 4 kilovolts He(+) (normal incidence) to a total dose of 1 x 10(exp 18) He(+) per square centimeter. We extracted thin sections from both irradiated and unirradiated regions in matrix using focused ion beam (FIB) techniques with electron beam deposition for the protective carbon strap to minimize surface damage artifacts from the FIB milling. The FIB sections were analyzed using a JEOL 2500SE scanning and transmission electron microscope (STEM) equipped with a Gatan Tridiem imaging filter. EELS spectra were collected from 50 nanometer diameter regions with an energy resolution of 0.7 electronvolts FWHM at the zero loss. EELS spectra were collected at low electron doses to minimize possible artifacts from electron-beam irradiation damage. Results and Discussion: Fe L (sub 2,3) EELS spectra from matrix phyllosilicates in CM chondrites show mixed Fe(2+)/Fe(3+) oxidation states with Fe(3+)/Sigma Fe approximately 0.5. Fe L(sub 2,3) spectra from the irradiated/ amorphized matrix phyllosilicates show higher Fe(2+)/Fe(3+) ratios compared to spectra obtained from pristine material at depths beyond the implantation/amorphization layer. We

Source apportionment of carbonaceous aerosol in southern Sweden

Directory of Open Access Journals (Sweden)

J. Genberg

2011-11-01

Full Text Available A one-year study was performed at the Vavihill background station in southern Sweden to estimate the anthropogenic contribution to the carbonaceous aerosol. Weekly samples of the particulate matter PM₁₀ were collected on quartz filters, and the amounts of organic carbon, elemental carbon, radiocarbon (¹⁴C and levoglucosan were measured. This approach enabled source apportionment of the total carbon in the PM₁₀ fraction using the concentration ratios of the sources. The sources considered in this study were emissions from the combustion of fossil fuels and biomass, as well as biogenic sources. During the summer, the carbonaceous aerosol mass was dominated by compounds of biogenic origin (80%, which are associated with biogenic primary and secondary organic aerosols. During the winter months, biomass combustion (32% and fossil fuel combustion (28% were the main contributors to the carbonaceous aerosol. Elemental carbon concentrations in winter were about twice as large as during summer, and can be attributed to biomass combustion, probably from domestic wood burning. The contribution of fossil fuels to elemental carbon was stable throughout the year, although the fossil contribution to organic carbon increased during the winter. Thus, the organic aerosol originated mainly from natural sources during the summer and from anthropogenic sources during the winter. The result of this source apportionment was compared with results from the EMEP MSC-W chemical transport model. The model and measurements were generally consistent for total atmospheric organic carbon, however, the contribution of the sources varied substantially. E.g. the biomass burning contributions of OC were underestimated by the model by a factor of 2.2 compared to the measurements.

Extraction products of solid carbonaceous materials

Energy Technology Data Exchange (ETDEWEB)

1937-11-04

A method is described for the manufacture of liquid products from pressure extracts of solid carbon-containing material by destructive hydrogenation, characterized in that the pressure extracts are hydrogenated in admixture with products of high-molecular weight formed during a previous destructive hydrogenation of another part of the same or other pressure extract and which has been collected as liquid without extensive cooling of the hot products of the reaction, which came from the reaction chamber where the previous destructive hydrogenation took place.

Modeling and analytical simulation of a smouldering carbonaceous ...

African Journals Online (AJOL)

Modeling and analytical simulation of a smouldering carbonaceous rod. A.A. Mohammed, R.O. Olayiwola, M Eseyin, A.A. Wachin. Abstract. Modeling of pyrolysis and combustion in a smouldering fuel bed requires the solution of flow, heat and mass transfer through porous media. This paper presents an analytical method ...

The analysis of creep characteristics of the surrounding rock of the carbonaceous rock tunnel based on Singh-Mitchell model

Science.gov (United States)

Luo, Junhui; Mi, Decai; Ye, Qiongyao; Deng, Shengqiang; Zeng, Fuquan; Zeng, Yongjun

2018-01-01

Carbonaceous rock has the characteristics of easy disintegration, softening, swelling and environmental sensitivity, which belongs to soft surrounding rock, and the deformation during excavation and long-term stability of the surrounding rock of carbonaceous rock tunnel are common problems in the construction of carbonaceous rock tunnel. According to the above, the Monitor and measure the displacement, temperature and osmotic pressure of the surrounding carbonaceous rock of the tunnel of Guangxi Hebai highway. Then it based on the obtaining data to study the creep mechanism of surrounding rock using Singh-Mitchell model and predict the deformation of surrounding rock before the tunnel is operation. The results show that the Singh-Mitchell creep model can effectively analyse and predict the deformation development law of surrounding rock of tunnel without considering temperature and osmotic pressure, it can provide reference for the construction of carbonaceous rock tunnel and the measures to prevent and reinforce it..

Characterization of Organic Materials in the Xenolithic Clasts in Sharps (H3.4) Meteorite Using Micro-Raman Spectroscopy

Science.gov (United States)

Chan, Q. H. S.; Zolensky, M. E.; Bodnar, R. J.; Kebukawa, Y.

2015-01-01

Graphitization of carbon is an irreversible process which alters the structure of graphitic materials in response to the increase in metamorphic grade (temperature and/or pressure). Carbonaceous materials offer a reliable geothermometer as their Raman spectra change systematically with increasing metamorphic grade. In this study, we identified carbonaceous materials in the xenolithic clasts in Sharps and interpreted their metamorphic history by revealing the structural organization (order) of the polyaromatic organic phases using micro-Raman spectroscopy.

Characterization of Organic Materials in the Xenolithic Clasts in Sharps (H3.4) Meteorite Using Microraman Spectroscopy

Science.gov (United States)

Chan, Q. H. S.; Zolensky, M. E.; Bodnar, R. J.; Kebukawa, Y.

2015-01-01

Graphitization of carbon is an irreversible process which alters the structure of graphitic materials in response to the increase in metamorphic grade (temperature and/or pressure). Carbonaceous materials offer a reliable geothermometer as their Raman spectra change systematically with increasing metamorphic grade [1-3]. In this study, we identified carbonaceous materials in the xenolithic clasts in Sharps and interpreted their metamorphic history by revealing the structural organization (order) of the polyaromatic organic phases using µ-Raman spectroscopy.

The Eocene Rusayl Formation, Oman, carbonaceous rocks in calcareous shelf sediments: Environment of deposition, alteration and hydrocarbon potential

Energy Technology Data Exchange (ETDEWEB)

Dill, H.G.; Wehner, H.; Kus, J. [Federal Institute for Geosciences and Natural Resources, P.O. Box 510163, D-30631 Hannover (Germany); Botz, R. [University Kiel, Geological-Paleontological Department, Olshausenstrasse 40-60, D-24118 Kiel (Germany); Berner, Z.; Stueben, D. [Technical University Karlsruhe, Institute for Mineralogy and Geochemistry, Fritz-Haber-Weg 2, D-76131 Karlsruhe (Germany); Al-Sayigh, A. [Sultan Qaboos University, Geological Dept. PO Box 36, Al-Khod (Oman)

2007-10-01

incursions make up a greater deal of the sedimentary record than mangrove swamps. Terra rossa paleosols mark the end of accumulation of organic material (OM) and herald supratidal conditions at the passage of Rusayl Formation into the overlying Seeb Formation. In the subtidal-supratidal cycles of lithofacies unit VIII the terra rossa horizons are thining upwards and become gradually substituted for by deep-water middle ramp sediments of lithofacies unit IX. Framboidal pyrite, (ferroan) dolomite with very little siderite are indicative of an early diagenetic alteration stage I under rather moderate temperatures of formation. During a subsequent stage II, an increase in the temperature of alteration was partly induced by burial and a high heat flow from the underlying Semail Ophiolite. Type-III kerogen originating from higher plants and, in addition, some marine biota gave rise to the generation of small amounts of soluble organic matter during this stage of diagenesis. The average reflectance of humic particles marks the beginning of the oil window and the production index reveals the existence of free hydrocarbons. Further uplift of the Eocene strata and oxidation during stage IIII caused veins of satin spar to form from organic sulfur and pyrite in the carbonaceous material. Lowering of the pH value of the pore fluid led to the precipitation of jarosite and a set of hydrated aluminum sulfates dependant upon the cations present in the wall rocks. AMD minerals (= acid mine drainage) are not very widespread in this carbonaceous series intercalated among calcareous rocks owing to the buffering effect of carbonate minerals. These carbonate-hosted carbonaceous rocks are below an economic level as far as the mining of coal is concerned, but deserves particular attention as source rocks for hydrocarbons in the Middle East, provided a higher stage of maturity is reached. (author)

Porous nitrogen-enriched carbonaceous material from marine waste: chitosan-derived layered CNX catalyst for aerial oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid

Science.gov (United States)

Chitosan derived porous layered nitrogen-enriched carbonaceous CNx catalyst (PLCNx) has been synthesized from marine waste and its use demonstrated in a metal-free heterogeneous selective oxidation of 5-hydroxymethyl-furfural (HMF) to 2,5-furandicarboxylic acid (FDCA) using aeria...

Quality evaluation of carbonaceous industrial by-products and its effect on properties of autoclave aerated concrete

Science.gov (United States)

Fomina, E. V.; Lesovik, V. S.; Fomin, A. E.; Kozhukhova, N. I.; Lebedev, M. S.

2018-03-01

Argillite is a carbonaceous industrial by-product that is a potential source in environmentally friendly and source-saving construction industry. In this research, chemical and mineral composition as well as particle size distribution of argillite were studied and used to develop autoclave aerated concrete as partial substitute of quartz sand. Effect of the argillite as a mineral admixture in autoclave aerated concrete was investigated in terms of compressive and tensile strength, density, heat conductivity etc. The obtained results demonstrated an efficiency of argillite as an energy-saving material in autoclave construction composites.

Characteristics and sources of carbonaceous aerosols from Shanghai, China

Science.gov (United States)

Cao, J.-J.; Zhu, C.-S.; Tie, X.-X.; Geng, F.-H.; Xu, H.-M.; Ho, S. S. H.; Wang, G.-H.; Han, Y.-M.; Ho, K.-F.

2013-01-01

An intensive investigation of carbonaceous PM2.5 and TSP (total suspended particles) from Pudong (China) was conducted as part of the MIRAGE-Shanghai (Megacities Impact on Regional and Global Environment) experiment in 2009. Data for organic and elemental carbon (OC and EC), organic species, including C17 to C40 n-alkanes and 17 polycyclic aromatic hydrocarbons (PAHs), and stable carbon isotopes OC (δ13COC) and EC (δ13CEC) were used to evaluate the aerosols' temporal variations and identify presumptive sources. High OC/EC ratios indicated a large fraction of secondary organic aerosol (SOA); high char/soot ratios indicated stronger contributions to EC from motor vehicles and coal combustion than biomass burning. Diagnostic ratios of PAHs indicated that much of the SOA was produced via coal combustion. Isotope abundances (δ13COC = -24.5 ± 0.8‰ and δ13CEC = -25.1 ± 0.6‰) indicated that fossil fuels were the most important source for carbonaceous PM2.5 (particulate matter less than 2.5 micrometers in diameter), with lesser impacts from biomass burning and natural sources. An EC tracer system and isotope mass balance calculations showed that the relative contributions to total carbon from coal combustion, motor vehicle exhaust, and SOA were 41%, 21%, and 31%; other primary sources such as marine, soil and biogenic emissions contributed 7%. Combined analyses of OC and EC, n-alkanes and PAHs, and stable carbon isotopes provide a new way to apportion the sources of carbonaceous particles.

Multifunctional materials and composites

Science.gov (United States)

Seo, Dong-Kyun; Jeon, Ki-Wan

2017-08-22

Forming multifunctional materials and composites thereof includes contacting a first material having a plurality of oxygen-containing functional groups with a chalcogenide compound, and initiating a chemical reaction between the first material and the chalcogenide compound, thereby replacing oxygen in some of the oxygen-containing functional groups with chalcogen from the chalcogen-containing compound to yield a second material having chalcogen-containing functional groups and oxygen-containing functional groups. The first material is a carbonaceous material or a macromolecular material. A product including the second material is collected and may be processed further to yield a modified product or a composite.

3-D assessment of peak-metamorphic conditions by Raman spectroscopy of carbonaceous material: an example from the margin of the Lepontine dome (Swiss Central Alps)

DEFF Research Database (Denmark)

Wiederkehr, Michael; Bousquet, Romain; Ziemann, Martin

2011-01-01

This study monitors regional changes in the crystallinity of carbonaceous matter (CM) by applying Micro-Raman spectroscopy to a total of 214 metasediment samples (largely so-called Bu¨ndnerschiefer) dominantly metamorphosed under blueschist- to amphibolite-facies conditions. They were collected w...

The carbonaceous concrete based on sawdust

Directory of Open Access Journals (Sweden)

BELOUSOVA Elena Sergeevna

2015-06-01

Full Text Available Today there are many requirements for strength, ecology and economy of produced concretes. The authors of the paper study attenuation of electromagnetic radiation of carbonaceous powders in the concrete composition. Carbon black was selected as a carbon powder for addition in concrete composition. Carbon black is a nanomaterial with disoriented structure of particles (average size is about 50 nm. The composition of the carbon black contains at least 90 wt.% amorphous carbon, more than 5 wt. % chemisorbed oxygen and about 4 wt.% of impurities. Materials with the addition of carbon black have electrical conductivity due to the high content of carbon. These materials are able to absorb electromagnetic radiation. For cement composition with addition of carbon black (more than 30 wt. % and water transmission coefficient of electromagnetic radiation is about –10 dB, for cement composition with 20 wt. % of carbon black the reflection coefficient is –8 dB in the frequency range 8–12 GHz. The concretes with a saturated aqueous solution of calcium chloride and 10% of carbon black possess minimal reflection coefficient (–14... –8 dB. Electromagnetic radiation shielding of concrete with the addition of sawdust was investigated. The concrete with sawdust (40 wt. % impregnated with an aqueous solution with carbon black has the reflection coefficient less than –8 dB and transmission coefficient –40 dB in the frequency range 8–12 GHz. These concretes can be used for creation of a shielded room with the technical equipment for information processing to prevent data leakage through the compromising emanations and crosstalk.

Antarctic carbonaceous chondrites - New opportunities for research

Science.gov (United States)

McSween, Harry Y., Jr.

An account is given of the types of carbonaceous meteorites available in the Antarctic collections of the U.S. and Japan. In the case of the collection for Victoria Land and Queen Maud Land, all known classes for meteorites except C1 are present; available pairing data, though limited, are indicative of the presence of many different falls. Thus far, attention has been focused on the largest meteorites. Most samples, however, are small.

Crystallography of Magnetite Plaquettes and their Significance as Asymmetric Catalysts for the Synthesis of Chiral Organics in Carbonaceous Chondrites

Science.gov (United States)

Chan, Q. H. S.; Zolensky, M. E.

2015-01-01

We have previously observed the magnetite plaquettes in carbonaceous chondrites using scanning electron microscope (SEM) imaging, examined the crystal orientation of the polished surfaces of magnetite plaquettes in CI Orgueil using electron backscattered diffraction (EBSD) analysis, and concluded that these magnetite plaquettes are likely naturally asymmetric materials. In this study, we expanded our EBSD observation to other magnetite plaquettes in Orgueil, and further examined the internal structure of these remarkable crystals with the use of X-ray computed microtomography.

The molecular structure of the insoluble organic matter isolated from Murchison carbonaceous chondrite.

Science.gov (United States)

Robert, F.; Derenne, S.

2009-04-01

During these last 10 years, our group has characterized the various molecular moieties of the insoluble organic matter (IOM) isolated from carbonaceous meteorites with the aim of reconstructing its overall molecular structure. Indeed, a precise knowledge of the structure of an organic macromolecule contains irreplaceable information that traces its mechanisms of synthesis and its conditions of formation. Such a modelled structure will be presented. Carbonaceous chondrites contain up to 3 wt % of carbon that is under the form of soluble and insoluble fractions. The IOM, which constitutes more than 75 wt% of the bulk organic matter, was isolated from the bulk rock through successive acid dissolutions. The chemical structure of the isolated IOM has been studied by both (1) destructive and (2) non destructive methods. Methods include thermal and chemical degradations followed by GC/MS, spectroscopic techniques (nuclear magnetic resonance, Fourier transform infra red spectroscopy; X-ray absorption near-edge spectroscopy, electron paramagnetic resonance) along with high resolution transmission electron microscopy. Although each technique alone cannot provide definite information on the chemical structure of such a complex material, the combination of the results can be used to reconstruct the molecular structure of the IOM. The proposed structure accounts for all these measured parameters. The details of this structure reveal information of the conditions of its formation in space and allow to discuss the mechanisms of organo-synthesis in the cosmochemical context of the formation of the solar system.

Impact of anthropogenic emissions and open biomass burning on regional carbonaceous aerosols in South China

Energy Technology Data Exchange (ETDEWEB)

Zhang Gan, E-mail: zhanggan@gig.ac.c [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Li Jun [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Li Xiangdong [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Xu Yue; Guo Lingli [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Tang Jianhui [Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); Lee, Celine S.L. [Department of Civil and Structural Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Liu Xiang [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chen Yingjun [Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China)

2010-11-15

Carbonaceous aerosols were studied at three background sites in south and southwest China. Hok Tsui in Hong Kong had the highest concentrations of carbonaceous aerosols (OC = 8.7 {+-} 4.5 {mu}g/m{sup 3}, EC = 2.5 {+-} 1.9 {mu}g/m{sup 3}) among the three sites, and Jianfeng Mountains in Hainan Island (OC = 5.8 {+-} 2.6 {mu}g/m{sup 3}, EC = 0.8 {+-} 0.4 {mu}g/m{sup 3}) and Tengchong mountain over the east edge of the Tibetan Plateau (OC = 4.8 {+-} 4.0 {mu}g/m{sup 3}, EC = 0.5 {+-} 0.4 {mu}g/m{sup 3}) showed similar concentration levels. Distinct seasonal patterns with higher concentrations during the winter, and lower concentrations during the summertime were observed, which may be caused by the changes of the regional emissions, and monsoon effects. The industrial and vehicular emissions in East, Southeast and South China, and the regional open biomass burning in the Indo-Myanmar region of Asia were probably the two major potential sources for carbonaceous matters in this region. - Anthropogenic emissions in China and open biomass burning in the Indo-Myanmar region were the two major potential sources for carbonaceous matters in South China region.

Impact of anthropogenic emissions and open biomass burning on regional carbonaceous aerosols in South China

International Nuclear Information System (INIS)

Zhang Gan; Li Jun; Li Xiangdong; Xu Yue; Guo Lingli; Tang Jianhui; Lee, Celine S.L.; Liu Xiang; Chen Yingjun

2010-01-01

Carbonaceous aerosols were studied at three background sites in south and southwest China. Hok Tsui in Hong Kong had the highest concentrations of carbonaceous aerosols (OC = 8.7 ± 4.5 μg/m 3 , EC = 2.5 ± 1.9 μg/m 3 ) among the three sites, and Jianfeng Mountains in Hainan Island (OC = 5.8 ± 2.6 μg/m 3 , EC = 0.8 ± 0.4 μg/m 3 ) and Tengchong mountain over the east edge of the Tibetan Plateau (OC = 4.8 ± 4.0 μg/m 3 , EC = 0.5 ± 0.4 μg/m 3 ) showed similar concentration levels. Distinct seasonal patterns with higher concentrations during the winter, and lower concentrations during the summertime were observed, which may be caused by the changes of the regional emissions, and monsoon effects. The industrial and vehicular emissions in East, Southeast and South China, and the regional open biomass burning in the Indo-Myanmar region of Asia were probably the two major potential sources for carbonaceous matters in this region. - Anthropogenic emissions in China and open biomass burning in the Indo-Myanmar region were the two major potential sources for carbonaceous matters in South China region.

In situ observation of D-rich carbonaceous globules embedded in NWA 801 CR2 chondrite

Science.gov (United States)

Hashiguchi, Minako; Kobayashi, Sachio; Yurimoto, Hisayoshi

2013-12-01

Eighty-five D-rich carbonaceous particles were identified in the matrix of the NWA 801 CR2 chondrite using isotope microscopy. The occurrence of 67 D-rich carbonaceous particles was characterized using secondary electron microscopy combined with X-ray elemental mapping. The close association of H and C, and D-enrichment suggests that the D-rich carbonaceous particles correspond to organic matter. The D-rich organic particles were scattered ubiquitously throughout the matrix at a concentration of approximately 660 ppm. The morphology of the D-rich carbonaceous particles is globular up to about 1 μm in diameter and is classified into four types: ring globules, round globules, irregular-shaped globules, and globule aggregates. The ring globules are ring-shaped organic matter containing silicate and/or oxide, with or without a void in the center. This is the first report of silicate and oxide grains surrounded by D-rich organic matter. The globule aggregates are composed of several D-rich organic globules mixed with silicates. Morphology of ring globules is very similar to core-mantle grain produced in the molecular cloud or in the outer solar nebula inferring by astronomy, suggesting that the organic globules have formed by UV photolysis in the ice mantle. Silicates or oxides attached to D-rich organic globules are the first observation among chondrites so far and may be unique nature of CR2 chondrites. The hydrogen isotopic compositions of the ring globules, round globules, irregular-shaped globules, and globule aggregates are δD = 3000-4800, 2900-8100, 2700-11,000, and 2500-11,000‰, respectively. Variations of D/H ratio of these organic globules seemed to be attributed to variations of D/H ratio of the organic radicals or differences of content of the D-rich organic radicals. There are no significant differences in the hydrogen isotopic compositions among the four types of D-rich carbonaceous matter. The D-enrichments suggest that these organic globules have

Carbonaceous particle record in lake sediments from the Arctic and other remote areas of the northern hemisphere

International Nuclear Information System (INIS)

Rose, N.L.

1995-01-01

Lake sediments, including spheroidal carbonaceous particles produced by high temperature combustion of fossil fuels, contain a record of lake, catchment and atmospheric deposition history. The spatial and temporal distributions of these particles can indicate the extent to which a single lake or a region has been contaminated by airborne pollutants (e.g. sulfur, polycyclic aromatic hydrocarbons (PAHs)) derived from fossil fuels. The carbonaceous particle records of two Arctic lakes, Shuonijavr and Stepanovichjarvi, close to local pollution sources on the Kola Peninsula, Russia, are compared with the record of a remote lake on Svalbard and with mid-latitude remote mountain lakes in Europe and Asia. Although, Shuonijavr and Stepanovichjarvi show relatively high levels of contamination, as expected, the presence of carbonaceous particles at all of the remote sites studied suggests there is a hemispherical background of these particles. Other less remote mountain lakes in Europe have been found to contain significant concentrations of particles and these may represent regional deposition patterns. Carbonaceous particle analysis may provide an effective assessment of whether a lake site is receiving local, regional or background levels of deposition

Processes for liquefying carbonaceous feedstocks and related compositions

Energy Technology Data Exchange (ETDEWEB)

MacDonnell, Frederick M.; Dennis, Brian H.; Billo, Richard E.; Priest, John W.

2017-02-28

Methods for the conversion of lignites, subbituminous coals and other carbonaceous feedstocks into synthetic oils, including oils with properties similar to light weight sweet crude oil using a solvent derived from hydrogenating oil produced by pyrolyzing lignite are set forth herein. Such methods may be conducted, for example, under mild operating conditions with a low cost stoichiometric co-reagent and/or a disposable conversion agent.

Turning Waste Chemicals into Wealth-A New Approach To Synthesize Efficient Cathode Material for an Li-O2 Battery.

Science.gov (United States)

Yao, Ying; Wu, Feng

2017-09-20

An Li-O 2 battery requires the oxygen-breathing cathode to be highly electronically conductive, rapidly oxygen diffusive, structurally stable, and often times electrocatalytically active. Catalyst-decorated porous carbonaceous materials are the chosen air cathode in this regard. Alternatively, biomass-derived carbonaceous materials possess great ability to remove heavy and toxic metal ions from waste, forming a metal-adsorbed porous carbonaceous material. The similar structure between the air cathode and the metal-adsorbed biomass-derived carbon nicely bridges these two irrelevant areas. In this study, we investigated the electrochemical activity of a biochar material Ag-ESB directly synthesized from ethanol sludge residue in a rechargeable aprotic Li-O 2 battery. Ag ions were adsorbed from sewage and became Ag nanoparticles with uniform coverage on the biochar surface. The as-prepared material exhibits good electrochemical behavior in battery testing, especially toward the battery efficiency and cyclability. This study provides the possibility of synthetically efficient cathode material by reusing "waste" such as biofuel sludge residue. It is an economically and environmentally friendly approach both for an energy-storage system and for waste recycling.

Pulmonary exposure to carbonaceous nanomaterials and sperm quality.

Science.gov (United States)

Skovmand, Astrid; Jacobsen Lauvås, Anna; Christensen, Preben; Vogel, Ulla; Sørig Hougaard, Karin; Goericke-Pesch, Sandra

2018-01-31

Semen quality parameters are potentially affected by nanomaterials in several ways: Inhaled nanosized particles are potent inducers of pulmonary inflammation, leading to the release of inflammatory mediators. Small amounts of particles may translocate from the lungs into the lung capillaries, enter the systemic circulation and ultimately reach the testes. Both the inflammatory response and the particles may induce oxidative stress which can directly affect spermatogenesis. Furthermore, spermatogenesis may be indirectly affected by changes in the hormonal milieu as systemic inflammation is a potential modulator of endocrine function. The aim of this study was to investigate the effects of pulmonary exposure to carbonaceous nanomaterials on sperm quality parameters in an experimental mouse model. Effects on sperm quality after pulmonary inflammation induced by carbonaceous nanomaterials were investigated by intratracheally instilling sexually mature male NMRI mice with four different carbonaceous nanomaterials dispersed in nanopure water: graphene oxide (18 μg/mouse/i.t.), Flammruss 101, Printex 90 and SRM1650b (0.1 mg/mouse/i.t. each) weekly for seven consecutive weeks. Pulmonary inflammation was determined by differential cell count in bronchoalveolar lavage fluid. Epididymal sperm concentration and motility were measured by computer-assisted sperm analysis. Epididymal sperm viability and morphological abnormalities were assessed manually using Hoechst 33,342/PI flourescent and Spermac staining, respectively. Epididymal sperm were assessed with regard to sperm DNA integrity (damage). Daily sperm production was measured in the testis, and testosterone levels were measured in blood plasma by ELISA. Neutrophil numbers in the bronchoalveolar fluid showed sustained inflammatory response in the nanoparticle-exposed groups one week after the last instillation. No significant changes in epididymal sperm parameters, daily sperm production or plasma testosterone levels

Regional variation of carbonaceous aerosols from space and simulations

Science.gov (United States)

Mukai, Sonoyo; Sano, Itaru; Nakata, Makiko; Kokhanovsky, Alexander

2017-04-01

Satellite remote sensing provides us with a systematic monitoring in a global scale. As such, aerosol observation via satellites is known to be useful and effective. However, before attempting to retrieve aerosol properties from satellite data, the efficient algorithms for aerosol retrieval need to be considered. The characteristics and distributions of atmospheric aerosols are known to be complicated, owing to both natural factors and human activities. It is known that the biomass burning aerosols generated by the large-scale forest fires and burn agriculture have influenced the severity of air pollution. Nevertheless the biomass burning episodes increase due to global warming and climate change and vice versa. It is worth noting that the near ultra violet (NUV) measurements are helpful for the detection of carbonaceous particles, which are the main component of aerosols from biomass burning. In this work, improved retrieval algorithms for biomass burning aerosols are shown by using the measurements observed by GLI and POLDER-2 on Japanese short term mission ADEOS-2 in 2003. The GLI sensor has 380nm channel. For detection of biomass burning episodes, the aerosol optical thickness of carbonaceous aerosols simulated with the numerical model simulations (SPRINTARS) is available as well as fire products from satellite imagery. Moreover the algorithm using shorter wavelength data is available for detection of absorbing aerosols. An algorithm based on the combined use of near-UV and violet data has been introduced in our previous work with ADEOS (Advanced Earth Observing Satellite) -2 /GLI measurements [1]. It is well known that biomass burning plume is a seasonal phenomenon peculiar to a particular region. Hence, the mass concentrations of aerosols are frequently governed with spatial and/or temporal variations of biomass burning plumes. Accordingly the satellite data sets for our present study are adopted from the view points of investigation of regional and seasonal

Hydrogen ion-driven permeation in carbonaceous films

International Nuclear Information System (INIS)

Anderl, R.A.; Holland, D.F.; Longhurst, G.R.

1989-01-01

This paper presents the results of investigations into the permeation properties of amorphous carbonaceous, a-C:H, films produced by plasmachemical deposition techniques. Carbonaceous films on iron substrates with thickness ranging from 60 nm to 110 nm were subjected to high fluence implantations with mass analyzed D 3 + ions with energies ranging from 600 eV to 3000 eV and fluxes ranging from 5x10 14 D/cm 2 s to 5x10 15 D/cm 2 s, respectively. Deuterium re-emission upstream, deuterium permeation downstream and secondary ions sputtered from the implantation surface were measured as a function of implantation fluence for specimens at 420 K. The present studies indicate that the a-C:H film permeability is directly related to the time, hence the fluence, required to achieve isotopic replacement and saturation of the deuterium ion beam atoms stopped in the implant region. Once the deuterium saturation level is achieved in the layer, a significant fraction of the implanting ions can result in permeation. For the present experiment, this permeation factor was much higher than that for uncoated iron specimens subjected to similar beam conditions. Carbon sputter yields of 0.008-0.01 C/D were determined in this work for 1000-eV to 400-eV deuterium ions incident on a-C:H films. (orig.)

Hydrogen ion-driven permeation in carbonaceous films

Energy Technology Data Exchange (ETDEWEB)

Anderl, R.A.; Holland, D.F.; Longhurst, G.R.

1989-04-01

This paper presents the results of investigations into the permeation properties of amorphous carbonaceous, a-C:H, films produced by plasmachemical deposition techniques. Carbonaceous films on iron substrates with thickness ranging from 60 nm to 110 nm were subjected to high fluence implantations with mass analyzed D/sub 3//sup +/ ions with energies ranging from 600 eV to 3000 eV and fluxes ranging from 5x10/sup 14/ D/cm/sup 2/ s to 5x10/sup 15/ D/cm/sup 2/ s, respectively. Deuterium re-emission upstream, deuterium permeation downstream and secondary ions sputtered from the implantation surface were measured as a function of implantation fluence for specimens at 420 K. The present studies indicate that the a-C:H film permeability is directly related to the time, hence the fluence, required to achieve isotopic replacement and saturation of the deuterium ion beam atoms stopped in the implant region. Once the deuterium saturation level is achieved in the layer, a significant fraction of the implanting ions can result in permeation. For the present experiment, this permeation factor was much higher than that for uncoated iron specimens subjected to similar beam conditions. Carbon sputter yields of 0.008-0.01 C/D were determined in this work for 1000-eV to 400-eV deuterium ions incident on a-C:H films. (orig.).

Hydrogen ion-driven permeation in carbonaceous films

Science.gov (United States)

Anderl, R. A.; Holland, D. F.; Longhurst, G. R.

1989-04-01

This paper presents the results of investigations into the permeation properties of amorphous carbonaceous, a-C: H, films produced by plasmachemical deposition techniques. Carbonaceous films on iron substrates with thickness ranging from 60 nm to 110 nm were subjected to high fluence implantations with mass analyzed D +3 ions with energies ranging from 600 eV to 3000 eV and fluxes ranging from 5 × 10 14D/ cm2 s to 5 × 10 15D/ cm2 s, respectively. Deuterium re-emission upstream, deuterium permeation downstream and secondary ions sputtered from the implantation surface were measured as a function of implantation fluence for specimens at 420 K. The present studies indicate that the a-C : H film permeability is directly related to the time, hence the fluence, required to achieve isotopic replacement and saturation of the deuterium ion beam atoms stopped in the implant region. Once the deuterium saturation level is achieved in the layer, a significant fraction of the implanting ions can result in permeation. For the present experiment, this permeation factor was much higher than that for uncoated iron specimens subjected to similar beam conditions. Carbon sputter yields of 0.008-0.01 C/D were determined in this work for 1000-eV to 400-eV deuterium ions incident on a-C : H films.

Processing Uranium-Bearing Materials Containing Coal and Loam

Energy Technology Data Exchange (ETDEWEB)

Civin, V; Prochazka, J [Research and Development Laboratory No. 3 of the Uranium Industry, Prague, Czechoslovakia (Czech Republic)

1967-06-15

Among the ores which are classified as low-grade in the CSSR are mixtures of coal and bentonitic loam of tertiary origin, containing approximately 0.1% U and with a moisture content at times well above 20-30%. The uranium is held mainly by the carbonaceous component. Conventional processing of these materials presents various difficulties which are not easily overcome. During leaching the pulp thickens and frequently becomes pasty, due to the presence of montmorillonites. Further complications arise from the high sorption capacity of the materials (again primarily due to montmorillonites) and poor sedimentation of the viscous pulps. In addition, the materials are highly refractory to the leaching agents. The paper presents experience gained in solving the problems of processing these ores. The following basic routes were explored: (1) separation of the carbonaceous and loamy components: The organic component appears to be the main activity carrier. Processing the concentrated material upon separation of the inactive or less active loam may not only remove the thixotropic behaviour but also substantially reduce the cost of the ore treatment; (2) 'liquifying' the pulps or preventing the thickening of the pulp by addition of suitable agents; (3) joint acid or carbonate processing of the materials in question with current ore types; (4) removal or suppression of thixotropic behaviour by thermal pretreatment of the material; and (5) application of the 'acid cure' method. The first method appears to be the most effective, but it presents considerable difficulties due to the extreme dispersion of the carbonaceous phase and further research is being carried out. Methods 2 and 3 proved to be unacceptable. Method 4, which includes roasting at 300-400{sup o}C, is now being operated on an industrial scale. The final method has also shown definite advantages for particular deposits of high montmorillonite content material. (author)

A dual origin for water in carbonaceous asteroids revealed by CM chondrites

Science.gov (United States)

Piani, Laurette; Yurimoto, Hisayoshi; Remusat, Laurent

2018-04-01

Carbonaceous asteroids represent the principal source of water in the inner Solar System and might correspond to the main contributors for the delivery of water to Earth. Hydrogen isotopes in water-bearing primitive meteorites, for example carbonaceous chondrites, constitute a unique tool for deciphering the sources of water reservoirs at the time of asteroid formation. However, fine-scale isotopic measurements are required to unravel the effects of parent-body processes on the pre-accretion isotopic distributions. Here, we report in situ micrometre-scale analyses of hydrogen isotopes in six CM-type carbonaceous chondrites, revealing a dominant deuterium-poor water component (δD = -350 ± 40‰) mixed with deuterium-rich organic matter. We suggest that this deuterium-poor water corresponds to a ubiquitous water reservoir in the inner protoplanetary disk. A deuterium-rich water signature has been preserved in the least altered part of the Paris chondrite (δDParis ≥ -69 ± 163‰) in hydrated phases possibly present in the CM rock before alteration. The presence of the deuterium-enriched water signature in Paris might indicate that transfers of ice from the outer to the inner Solar System were significant within the first million years of the history of the Solar System.

Characteristics and sources of carbonaceous aerosols from Shanghai, China

Directory of Open Access Journals (Sweden)

J.-J. Cao

2013-01-01

Full Text Available An intensive investigation of carbonaceous PM_2.5 and TSP (total suspended particles from Pudong (China was conducted as part of the MIRAGE-Shanghai (Megacities Impact on Regional and Global Environment experiment in 2009. Data for organic and elemental carbon (OC and EC, organic species, including C17 to C40 n-alkanes and 17 polycyclic aromatic hydrocarbons (PAHs, and stable carbon isotopes OC (δ¹³C_OC and EC (δ¹³C_EC were used to evaluate the aerosols' temporal variations and identify presumptive sources. High OC/EC ratios indicated a large fraction of secondary organic aerosol (SOA; high char/soot ratios indicated stronger contributions to EC from motor vehicles and coal combustion than biomass burning. Diagnostic ratios of PAHs indicated that much of the SOA was produced via coal combustion. Isotope abundances (δ¹³C_OC = −24.5 ± 0.8‰ and δ¹³C_EC = −25.1 ± 0.6‰ indicated that fossil fuels were the most important source for carbonaceous PM_2.5 (particulate matter less than 2.5 micrometers in diameter, with lesser impacts from biomass burning and natural sources. An EC tracer system and isotope mass balance calculations showed that the relative contributions to total carbon from coal combustion, motor vehicle exhaust, and SOA were 41%, 21%, and 31%; other primary sources such as marine, soil and biogenic emissions contributed 7%. Combined analyses of OC and EC, n-alkanes and PAHs, and stable carbon isotopes provide a new way to apportion the sources of carbonaceous particles.

Ethanol and other oxygenateds from low grade carbonaceous resources

Energy Technology Data Exchange (ETDEWEB)

Joo, O.S.; Jung, K.D.; Han, S.H. [Korea Institute of Science and Technology, Seoul (Korea, Democratic People`s Republic of)] [and others

1995-12-31

Anhydrous ethanol and other oxygenates of C2 up can be produced quite competitively from low grade carbonaceous resources in high yield via gasification, methanol synthesis, carbonylation of methanol an hydrogenation consecutively. Gas phase carbonylation of methanol to form methyl acetate is the key step for the whole process. Methyl acetate can be produced very selectively in one step gas phase reaction on a fixed bed column reactor with GHSV over 5,000. The consecutive hydrogenation of methyl or ethyl acetate produce anhydrous ethanol in high purity. It is also attempted to co-produce methanol and DME in IGCC, in which low grade carbonaceous resources are used as energy sources, and the surplus power and pre-power gas can be stored in liquid form of methanol and DME during base load time. Further integration of C2 up oxygenate production with IGCC can improve its economics. The attempt of above extensive technology integration can generate significant industrial profitability as well as reduce the environmental complication related with massive energy consumption.

Carbonaceous Components in the Comet Halley Dust

Science.gov (United States)

Fomenkova, M. N.; Chang, S.; Mukhin, L. M.

1994-01-01

Cometary grains containing large amounts of carbon and/or organic matter (CHON) were discovered by in situ measurements of comet Halley dust composition during VEGA and GIOTTO flyby missions. In this paper, we report the classification of these cometary, grains by means of cluster analysis, discuss the resulting compositional groups, and compare them with substances observed or hypothesized in meteorites, interplanetary dust particles, and the interstellar medium. Grains dominated by carbon and/or organic matter (CHON grains) represent approx. 22% of the total population of measured cometary dust particles. They, usually contain a minor abundance of rock-forming elements as well. Grains having organic material are relatively more abundant in the vicinity of the nucleus than in the outer regions of the coma, which suggests decomposition of the organics in the coma environment. The majority of comet Halley organic particles are multicomponent mixtures of carbon phases and organic compounds. Possibly, the cometary CHON grains may be related to kerogen material of an interstellar origin in carbonaceous meteorites. Pure carbon grains, hydrocarbons and polymers of cyanopolyynes, and multi-carbon monoxides are present in cometary dust as compositionally simple and distinctive components among a variety of others. There is no clear evidence of significant presence of pure formaldehyde or HCN polymers in Halley dust particles. The diversity of types of cometary organic compounds is consistent with the inter-stellar dust model of comets and probably reflects differences in composition of precursor dust. Preservation of this heterogeneity among submicron particles suggest the gentle formation of cometary, nucleus by aggregation of interstellar dust in the protosolar nebula without complete mixing or chemical homogenization at the submicron level.

Composition and sources of carbonaceous aerosols in Northern Europe during winter

NARCIS (Netherlands)

Glasius, M.; Hansen, A.M.K.; Claeys, M.; Henzing, J.S.; Jedynska, A.D.; Kasper-Giebl, A.; Kistler, M.; Kristensen, K.; Martinsson, J.; Maenhaut, W.; Nøjgaard, J.K.; Spindler, G.; Stenström, K.E.; Swietlicki, E.; Szidat, S.; Simpson, D.; Yttri, K.E.

2018-01-01

Sources of elemental carbon (EC) and organic carbon (OC) in atmospheric aerosols (carbonaceous aerosols) were investigated by collection of weekly aerosol filter samples at six background sites in Northern Europe (Birkenes, Norway; Vavihill, Sweden; Risoe, Denmark; Cabauw and Rotterdam in The

Radar-Enabled Recovery of the Sutters Mill Meteorite, a Carbonaceous Chondrite Regolith Breccia

Science.gov (United States)

Jenniskens, Petrus M.; Fries, Marc D.; Yin, Qing-Zhu; Zolensky, Michael E.; Krot, Alexander N.; Sandford, Scott A.; Sears, Derek; Beauford, Robert; Ebel, Denton S.; Friedrich, Jon M.;

Quenched carbonaceous composite - Fluorescence spectrum compared to the extended red emission observed in reflection nebulae

Science.gov (United States)

Sakata, Akira; Wada, Setsuko; Narisawa, Takatoshi; Asano, Yoichi; Iijima, Yutaka; Onaka, Takashi; Tokunaga, Alan T.

1992-01-01

The photoluminescence (fluorescence) of a film of the laboratory-synthesized quenched carbonaceous composite (filmy QCC) is shown to have a single broad emission feature with a peak wavelength that varies from 670 to 725 nm, and coincides with that of the extended red emission observed in reflection nebulae. The rapid decay of the filmy QCC red fluorescence in air and of the stable blue fluorescence of the filmy QCC dissolved in liquid Freon suggests that the red fluorescence originates from the interaction of active chemical species and aromatic components in the filmy QCC. A material similar in nature to that of the filmy QCC may be a major component of interstellar dust.

Carbonaceous aerosol characteristics over Delhi in Northern India: Seasonal variability and possible sources

Science.gov (United States)

Srivastava, Atul Kumar; Bisht, Ds; Tiwari, S.

Carbonaceous aerosols have been the focus of extensive studies during the last decade due to its significant impacts on human health, visibility and climate change. As per Asian regions are concerned, aerosols in south-Asia are gaining considerable importance because of their potential impacts on regional climate, yet their possible sources are poorly understood. Semi-continuous measurements of organic carbon (OC) and elemental carbon (EC) and continuous measurements of black carbon (BC) aerosols were conducted simultaneously at Delhi during the period from January 2011 to May 2012. Delhi is the capital city of India and one of the densely populated and industrialized urban megacities in Asia, located at the Ganga basin in the northern part of India. Being highly polluted region, mass concentrations of OC, EC and BC over Delhi were found to vary from about 6-92 mug m (-3) (mean: 23±16 mug m (-3) ), 3-38 mug m (-3) (mean: 11±7 mug m (-3) ) and 1-24 mug m (-3) (mean: 7±5 mug m (-3) ), respectively during the entire measurement period, with about two times higher concentration during winter as compared to summer. A significant correlation between OC and EC (R=0.95, n=232) and relatively lower OC/EC ratio (range: 1.0-3.6; mean: 2.2±0.5) suggest fossil fuel emission as a dominant source of carbonaceous aerosols over the station. The average mass concentration of EC was found about 38% higher than BC during the study period, which is interestingly different as reported at other locations over Ganga basin. We also determined the associated optical properties of carbonaceous species (e.g. absorption coefficient and mass absorption efficiency) over the station. Significant loading of carbonaceous species over such regions emphasize an urgent need to focus on air quality management and proper impact assessment on health perspective.

Report compiled by Research Center for Carbonaceous Resources, Institute for Chemical Reaction Science, Tohoku University; Tohoku Daigaku Hanno Kagaku Kenkyusho tanso shigen hanno kenkyu center hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-04-01

The Research Center for Carbonaceous Resources was established in April 1991 for the purpose of developing a comprehensive process for converting carbonaceous resources into clean fuels or into materials equipped with advanced functions. In this report, the track records etc. of the center are introduced. Under study in the conversion process research department is the organization of a comprehensive coal conversion process which will be a combination of solvent extraction, catalytic decomposition, and catalytic gasification, whose goal is to convert coal in a clean way at high efficiency. Under study in the conversion catalyst research department are the development of a coal denitrogenation method, development of a low-temperature gasification method by use of inexpensive catalysts, synthesis of C{sub 2} hydrocarbons in a methane/carbon dioxide reaction, etc. Other endeavors under way involve the designing and development of new organic materials such as new carbon materials and a study of the foundation on which such efforts stand, that is, the study of the control of reactions between solids. Furthermore, in the study of interfacial reaction control, the contact gasification of coal, brown coal ion exchange capacity and surface conditions, carbonization of cation exchanged brown coal, etc., are being developed. (NEDO)

Preparing patterned carbonaceous nanostructures directly by overexposure of PMMA using electron-beam lithography

Energy Technology Data Exchange (ETDEWEB)

Duan Huigao; Zhao Jianguo; Zhang Yongzhe; Xie Erqing [School of Physical Science and Technology, Lanzhou University, Lanzhou 730000 (China); Han Li [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China)], E-mail: duanhg@gmail.com, E-mail: xieeq@lzu.edu.cn

2009-04-01

The overexposure process of poly(methyl methacrylate) (PMMA) was studied in detail using electron-beam lithography. It was found that PMMA films could be directly patterned without development due to the electron-beam-induced collapse of PMMA macromolecular chains. By analyzing the evolution of surface morphologies and compositions of the overexposed PMMA films, it was also found that the transformation of PMMA from positive to negative resist was a carbonization process, so patterned carbonaceous nanostructures could be prepared directly by overexposure of PMMA using electron-beam lithography. This simple one-step process for directly obtaining patterned carbonaceous nanostructures has promising potential application as a tool to make masks and templates, nanoelectrodes, and building blocks for MEMS and nanophotonic devices.

Carbon nanocages as supercapacitor electrode materials.

Science.gov (United States)

Xie, Ke; Qin, Xingtai; Wang, Xizhang; Wang, Yangnian; Tao, Haisheng; Wu, Qiang; Yang, Lijun; Hu, Zheng

2012-01-17

Supercapacitor electrode materials: Carbon nanocages are conveniently produced by an in situ MgO template method and demonstrate high specific capacitance over a wide range of charging-discharging rates with high stability, superior to the most carbonaceous supercapacitor electrode materials to date. The large specific surface area, good mesoporosity, and regular structure are responsible for the excellent performance. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

PCB congener sorption to carbonaceous sediment components: Macroscopic comparison and characterization of sorption kinetics and mechanism

International Nuclear Information System (INIS)

Choi, Hyeok; Al-Abed, Souhail R.

2009-01-01

Sorption of polychlorinated biphenyls (PCBs) to sediment is a key process in determining their mobility, bioavailability, and chemical decomposition in aquatic environments. In order to examine the validity of currently used interpretation approaches for PCBs sorption, comparative results on 2-chlorobiphenyl sorption to carbonaceous components in sediments (activated carbon, carbon black, coal, soot, graphite, flyash, wood) were macroscopically correlated with the structural, morphological, crystallographic, and compositional properties of the carbonaceous components. Since the Freundlich sorption constant, K F (L kg -1 ) spanned several orders of magnitude, ranging from log K F of 6.13-5.27 for activated carbon, 5.04 for carbon black, 3.83 for coal to 3.08 for wood, organic carbon partitioning approach should be more specifically categorized, considering the various forms, nature and origins of organic carbon in sediment. Sorption rate constants and fraction parameters, which were numerically defined from empirical kinetic model with fast and slow sorption fractions, were closely related to the physicochemical properties of the carbonaceous components. Sorption interpretation approaches with a specific property and viewpoint, such as organic carbon partitioning, soot carbon distribution, or surface area correlation, did not properly explain the overall results on sorption capacity, fast and slow sorption kinetics, and partitioning coefficient. It is also important to emphasize the heterogeneous nature of sediment and the difficulties of encompassing the partitioning among its carbonaceous components.

PCB congener sorption to carbonaceous sediment components: Macroscopic comparison and characterization of sorption kinetics and mechanism

Energy Technology Data Exchange (ETDEWEB)

Choi, Hyeok [National Risk Management Research Laboratory, U.S. Environmental Protection Agency, 26 West Martin Luther King Drive, Cincinnati, OH 45268 (United States); Al-Abed, Souhail R., E-mail: al-abed.souhail@epa.gov [National Risk Management Research Laboratory, U.S. Environmental Protection Agency, 26 West Martin Luther King Drive, Cincinnati, OH 45268 (United States)

2009-06-15

Sorption of polychlorinated biphenyls (PCBs) to sediment is a key process in determining their mobility, bioavailability, and chemical decomposition in aquatic environments. In order to examine the validity of currently used interpretation approaches for PCBs sorption, comparative results on 2-chlorobiphenyl sorption to carbonaceous components in sediments (activated carbon, carbon black, coal, soot, graphite, flyash, wood) were macroscopically correlated with the structural, morphological, crystallographic, and compositional properties of the carbonaceous components. Since the Freundlich sorption constant, K{sub F} (L kg{sup -1}) spanned several orders of magnitude, ranging from log K{sub F} of 6.13-5.27 for activated carbon, 5.04 for carbon black, 3.83 for coal to 3.08 for wood, organic carbon partitioning approach should be more specifically categorized, considering the various forms, nature and origins of organic carbon in sediment. Sorption rate constants and fraction parameters, which were numerically defined from empirical kinetic model with fast and slow sorption fractions, were closely related to the physicochemical properties of the carbonaceous components. Sorption interpretation approaches with a specific property and viewpoint, such as organic carbon partitioning, soot carbon distribution, or surface area correlation, did not properly explain the overall results on sorption capacity, fast and slow sorption kinetics, and partitioning coefficient. It is also important to emphasize the heterogeneous nature of sediment and the difficulties of encompassing the partitioning among its carbonaceous components.

AFM measurements of adhesive forces between carbonaceous particles and the substrates

Energy Technology Data Exchange (ETDEWEB)

Zhang, Tianqi [Institute of Nuclear and New Energy Technology of Tsinghua University, Collaborative Innovation Center of Advanced Nuclear Energy Technology, Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education, Beijing 100084 (China); Peng, Wei, E-mail: pengwei@tsinghua.edu.cn [Institute of Nuclear and New Energy Technology of Tsinghua University, Collaborative Innovation Center of Advanced Nuclear Energy Technology, Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education, Beijing 100084 (China); Shen, Ke [Institute of Nuclear and New Energy Technology of Tsinghua University, Collaborative Innovation Center of Advanced Nuclear Energy Technology, Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education, Beijing 100084 (China); Yu, Suyuan, E-mail: suyuan@tsinghua.edu.cn [Center for Combustion Energy, Key Laboratory for Thermal Science and Power Engineering of Ministry of Educations, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China)

2015-11-15

Highlights: • Adhesive force of spherical carbonaceous particle MCMBs and HTR-10 graphite matrix debris were measured for the first time. • The measured equivalent works of adhesion were much smaller than the ideal values. • The shape factor and the particle morphology reduce the adhesive force. • The adhesion effect does not change directly with the asperity size. - Abstract: Graphite dust is carbonaceous particles generated during operation of High Temperature Gas-Cooled Reactors (HTR). Graphite dust resuspension is the key behavior associated with HTR source term analyses and environmental safety assessment. The adhesive force is the key factor that determines the resuspension rate. The present study used an atomic force microscope (AFM) to measure the adhesive force between a single carbonaceous particle and the substrate. The measurements were performed on mica, graphite IG110 and Inconel 800H. The prepared “probe cantilevers” were mesocarbon microbeads (MCMB), fuel element debris from HTR-10 and graphite NBG18. The equivalent work of adhesion was derived from the measured adhesive force and calculated based on substrate profile approximation and the JKR theoretical model. The measured work was smaller than the ideal work of adhesion, most likely due to the rough particle morphology and the rough substrate surface. Additionally, a shape factor imposes a constraint on the lateral deformation of the particles. Furthermore, surface roughness could reduce the adhesive force some depending on the particle size. Once the particle was too small to be trapped into a trough, the adhesive force would not be further reduced.

AFM measurements of adhesive forces between carbonaceous particles and the substrates

International Nuclear Information System (INIS)

Zhang, Tianqi; Peng, Wei; Shen, Ke; Yu, Suyuan

2015-01-01

Highlights: • Adhesive force of spherical carbonaceous particle MCMBs and HTR-10 graphite matrix debris were measured for the first time. • The measured equivalent works of adhesion were much smaller than the ideal values. • The shape factor and the particle morphology reduce the adhesive force. • The adhesion effect does not change directly with the asperity size. - Abstract: Graphite dust is carbonaceous particles generated during operation of High Temperature Gas-Cooled Reactors (HTR). Graphite dust resuspension is the key behavior associated with HTR source term analyses and environmental safety assessment. The adhesive force is the key factor that determines the resuspension rate. The present study used an atomic force microscope (AFM) to measure the adhesive force between a single carbonaceous particle and the substrate. The measurements were performed on mica, graphite IG110 and Inconel 800H. The prepared “probe cantilevers” were mesocarbon microbeads (MCMB), fuel element debris from HTR-10 and graphite NBG18. The equivalent work of adhesion was derived from the measured adhesive force and calculated based on substrate profile approximation and the JKR theoretical model. The measured work was smaller than the ideal work of adhesion, most likely due to the rough particle morphology and the rough substrate surface. Additionally, a shape factor imposes a constraint on the lateral deformation of the particles. Furthermore, surface roughness could reduce the adhesive force some depending on the particle size. Once the particle was too small to be trapped into a trough, the adhesive force would not be further reduced.

Retort for coal, shale, and other carbonaceous material

Energy Technology Data Exchange (ETDEWEB)

Moure, K R

1930-12-15

A truncated conical retort chamber is described with a water tank or pit below the level of the floor of the retort, an aperture is the base of the retort chamber, a water-sealed chamber is interposed between the aperture at the base of the retort chamber and the water tank or pit, the upper end of the water-sealed chamber is connected to the retort chamber so as to make an air-tight joint therewith. Its lower end is submerged in the water in the tank or pit, an endless chain grate rotatably mounted upon a frame upon the floor of the retort chamber. The chain grate is inclined toward and projecting through the aperture at the base of the retort chamber into the water-sealed chamber for the purpose of conveying the spent material from the retort chamber to the water-sealed chamber through which it will gravitate to the water tank or pit. Means such as a bucket conveyor are provided for raising the spent material from the water tank or pit. Means are provided for rotating the endless chain grate, superimposed cylindrical feed chambers are upon the top of and in axial line with the retort chamber, a coned valve is interposed between the retort chamber and the next adjacent cylindrical chamber, another valve is interposed between the upper and lower cylindrical chambers. Means are provided for opening and closing the valves alternately, a discharge aperature is at or near the top of the retortchamber, and means are provided for feeding the material into the uppermost cylindrical feed chamber.

Carbonaceous Materials Obtained from Sewage Sludge for NO2 Removal under Wet Conditions at Room Temperature

International Nuclear Information System (INIS)

Pietrzak, R.

2010-01-01

The effect of the processes of carbonisation and activation on adsorbents obtained from sewage sludge and their sorption properties towards NO 2 were studied. Carbonaceous adsorbents were obtained by carbonisation of sewage sludge at 600 o C for four different times 30, 60, 90 and 120 min followed by activation of the carbonisates by CO 2 at 800 o C for 60 min. Adsorption of NO 2 was carried out in wet air. It has been shown that by appropriate thermal and chemical treatment of sludge, mesoporous adsorbents capable of NO 2 removal can be obtained. The sorption abilities of the carbonised and activated samples to adsorb NO 2 have been shown to increase with increased time of carbonisation and reach maximum for the carbonisation maintained for 90 min. Further increase in this time causes a decrease in the adsorption abilities of the samples. The sorption properties of the carbonisates have been proved to be determined by the chemical character of the surface, while those of the activated samples - by the porous structure. (author)

Comparative study of adsorptive role of carbonaceous materials in removal of UV-active impurities of paclitaxel extracts

Directory of Open Access Journals (Sweden)

Jaber Nasiri

2015-12-01

Full Text Available Graphite oxide (GO and reduced graphene oxide (rGO nanosheets were synthesized with a low-cost manufacturing method. The morphology and structures of the synthesized samples were studied using X-ray diffraction (XRD, atomic force microscopy (AFM, Fourier-transform infrared (FTIR and Raman spectroscopy. The efficiencies of GO and rGO as novel candidate adsorbents in the pre-purification of paclitaxel were compared and contrasted with those of commercial graphite (Gt, graphene (G and multi-wall carbon nanotube (MWCNT. According to UV–vis and HPLC analyses, rGO was evaluated as the best absorbent for the removal of impurities in pre-purification of paclitaxel from plant cell cultures. In contrast, the GO had the poorest proficiency for paclitaxel pre-purification in comparison with the other carbonaceous adsorbents. This is attributed to the existence of many localized defects in the π-structure of GO that is related to weakness of π–π stacking interactions between crude extract impurities and GO.

Conditions of formation for carbonaceous silicites of the continental margins

Energy Technology Data Exchange (ETDEWEB)

Bazhenova, O.K.

1986-06-01

Carbonaceous silicites occur in virtually all systems in Phanerozoic folded regions. They are of practical interest as concentrators of silver, molybdenum, vanadium, and nickel and as source and occasionally reservoir beds for petroleum. Some small oil pools occur in them in basins in Japan (Niigata and Akita), California, and East Sakhalin. Recently, interest has increased because a major pool was discovered in silicites of the Monterey formation: Point Arguello Hueso in the offshore part of the Santa Maria basin. Here the authors consider carbonaceous silicates in the western part of the Pacific active margin, which include Silurian and Devonian phthanites in the Mongolia-Okhotsk belt, and Triassic and Jurassic phthanites in the Sikhote-Alin area, although these rocks are of fairly local occurrence in the section. The authors have examined silicites in Kamchatka, Sakhalin, and Chukotka: diatomites, tuff-diatomites, and opokas, together with their recrystallized analogs. They occur in the Paleogene, but they are most abundant in the Miocene and Pliocene, as well as in the Jurassic, Cretaceous, and Eocene, particularly in the Miocene of California and Japan. 16 references.

Amino acid compositions in heated carbonaceous chondrites and their compound-specific nitrogen isotopic ratios

Science.gov (United States)

Chan, Queenie Hoi Shan; Chikaraishi, Yoshito; Takano, Yoshinori; Ogawa, Nanako O.; Ohkouchi, Naohiko

2016-01-01

A novel method has been developed for compound-specific nitrogen isotope compositions with an achiral column which was previously shown to offer high precision for nitrogen isotopic analysis. We applied the method to determine the amino acid contents and stable nitrogen isotopic compositions of individual amino acids from the thermally metamorphosed (above 500 °C) Antarctic carbonaceous chondrites Ivuna-like (CI)1 (or CI-like) Yamato (Y) 980115 and Ornans-like (CO)3.5 Allan Hills (ALH) A77003 with the use of gas chromatography/combustion/isotope ratio mass spectrometry. ALHA77003 was deprived of amino acids due to its extended thermal alteration history. Amino acids were unambiguously identified in Y-980115, and the δ15N values of selected amino acids (glycine +144.8 ‰; α-alanine +121.2 ‰) are clearly extraterrestrial. Y-980115 has experienced an extended period of aqueous alteration as indicated by the presence of hydrous mineral phases. It has also been exposed to at least one post-hydration short-lived thermal metamorphism. Glycine and alanine were possibly produced shortly after the accretion event of the asteroid parent body during the course of an extensive aqueous alteration event and have abstained from the short-term post-aqueous alteration heating due to the heterogeneity of the parent body composition and porosity. These carbonaceous chondrite samples are good analogs that offer important insights into the target asteroid Ryugu of the Hayabusa-2 mission, which is a C-type asteroid likely composed of heterogeneous materials including hydrated and dehydrated minerals.

Enantiomer excesses of rare and common sugar derivatives in carbonaceous meteorites

Science.gov (United States)

Cooper, George; Rios, Andro C.

2016-06-01

Biological polymers such as nucleic acids and proteins are constructed of only one—the d or l—of the two possible nonsuperimposable mirror images (enantiomers) of selected organic compounds. However, before the advent of life, it is generally assumed that chemical reactions produced 50:50 (racemic) mixtures of enantiomers, as evidenced by common abiotic laboratory syntheses. Carbonaceous meteorites contain clues to prebiotic chemistry because they preserve a record of some of the Solar System’s earliest (˜4.5 Gy) chemical and physical processes. In multiple carbonaceous meteorites, we show that both rare and common sugar monoacids (aldonic acids) contain significant excesses of the d enantiomer, whereas other (comparable) sugar acids and sugar alcohols are racemic. Although the proposed origins of such excesses are still tentative, the findings imply that meteoritic compounds and/or the processes that operated on meteoritic precursors may have played an ancient role in the enantiomer composition of life’s carbohydrate-related biopolymers.

Enantiomer excesses of rare and common sugar derivatives in carbonaceous meteorites.

Science.gov (United States)

Cooper, George; Rios, Andro C

2016-06-14

Biological polymers such as nucleic acids and proteins are constructed of only one-the d or l-of the two possible nonsuperimposable mirror images (enantiomers) of selected organic compounds. However, before the advent of life, it is generally assumed that chemical reactions produced 50:50 (racemic) mixtures of enantiomers, as evidenced by common abiotic laboratory syntheses. Carbonaceous meteorites contain clues to prebiotic chemistry because they preserve a record of some of the Solar System's earliest (∼4.5 Gy) chemical and physical processes. In multiple carbonaceous meteorites, we show that both rare and common sugar monoacids (aldonic acids) contain significant excesses of the d enantiomer, whereas other (comparable) sugar acids and sugar alcohols are racemic. Although the proposed origins of such excesses are still tentative, the findings imply that meteoritic compounds and/or the processes that operated on meteoritic precursors may have played an ancient role in the enantiomer composition of life's carbohydrate-related biopolymers.

Source apportionment of atmospheric carbonaceous particulate matter based on the radiocarbon

International Nuclear Information System (INIS)

Guang-hua Wang; You-shi Zeng; Jian Yao; Yuan Qian; Ke Liu; Wei Liu; Yan Li; Yu Huang; University of South China, Hunan

2013-01-01

A method was established to quantitatively estimate sources of atmospheric carbonaceous matter, using a combination of radiocarbon technology, linear regression of organic carbon (OC) -K + and elemental carbon (EC) tracer method. Fractional contributions of fossil fuels, biomass burning, biogenic secondary organic carbon (BSOC) and soil dust to the atmospheric size-resolved carbonaceous matters in Shanghai suburb were estimated using this new method. The fossil carbon contributed most of the OC in particles smaller than 0.49 μm, and its fraction decreased with the increase of particle size. Biomass burning contributed 17-28 % to the OC. The BSOC contributed comparable proportions to the OC in particles smaller than 3.0 μm with the biomass burning, but larger in the particles lager than 3.0 μm. The soil dust contributed least fraction to the OC of each size with a proportion of 2-13 %. The biomass burning and fossil sources shared comparable fraction of the EC in all size range. (author)

Turning Waste Chemicals into Wealth—A New Approach To Synthesize Efficient Cathode Material for an Li–O ₂ Battery

Energy Technology Data Exchange (ETDEWEB)

Yao, Ying; Wu, Feng (Beijing Inst. Tech.)

2017-03-20

An Li–O₂ battery requires the oxygen-breathing cathode to be highly electronically conductive, rapidly oxygen diffusive, structurally stable, and often times electrocatalytically active. Catalyst-decorated porous carbonaceous materials are the chosen air cathode in this regard. Alternatively, biomass-derived carbonaceous materials possess great ability to remove heavy and toxic metal ions from waste, forming a metal-adsorbed porous carbonaceous material. The similar structure between the air cathode and the metal-adsorbed biomass-derived carbon nicely bridges these two irrelevant areas. In this study, we investigated the electrochemical activity of a biochar material Ag-ESB directly synthesized from ethanol sludge residue in a rechargeable aprotic Li–O₂ battery. Ag ions were adsorbed from sewage and became Ag nanoparticles with uniform coverage on the biochar surface. The as-prepared material exhibits good electrochemical behavior in battery testing, especially toward the battery efficiency and cyclability. This study provides the possibility of synthetically efficient cathode material by reusing “waste” such as biofuel sludge residue. It is an economically and environmentally friendly approach both for an energy-storage system and for waste recycling.

The use of halogen carriers and buffers in the spectrographic determination of boron in carbonaceous materials and their combustion products; Empleo de agentes halogenantes y reguladores en la determinacion espectrografica de Boro en carbones y productos derivados

Energy Technology Data Exchange (ETDEWEB)

Rucandio, M I; Martin, M; Roca, M

1992-07-01

For the determination of boron in carbonaceous materials (high purity graphite, coals and their processed products, such as ashes and slags from thermoelectric power plants) by atomic emission spectroscopy with direct current are excitation and photographic recording, the behaviour of the analyte in the presence of halide compounds or spectrochemical buffers has been studied. Among the halides, cupric fluoride at a low concentration (2%) becomes very suitable for the graphite analysis, and at a higher concentration (25 %) for coals, being necessary in this case to carry out a dilution of samples with graphite. Strontium carbonate as a spectrochemical buffer allows to analyse satisfactorily coals and their combustion products. (Author) 13 refs.

Ultraviolet reflectance spectroscopy measurements of carbonaceous meteorites and planetary analog materials

Science.gov (United States)

Hibbitts, Charles A.; Stockstill-Cahill, Karen; Takir, Driss

2017-10-01

The compositions of airless solar system objects tell us about the origin and evolutionary processes that are responsible for the current state of our solar system and that shape our environment. Spectral reflectance measurements in the ultraviolet are being used more frequently for providing compositional information of airless solid surfaces. Most minerals absorb in the UV making studying surface composition both informative but also challenging [e.g. 1]. The UV region is sensitive to atomic and molecular electronic absorptions such as the ligand-metal charge transfer band that is present in oxides and silicates and the conduction band at vacuum UV wavelengths. At the JHU-APL, bidirectional UV reflectance measurements are obtained under vacuum using a McPherson monochrometer with a PMT detector to achieve measurements over the range from ~ 140 nm to ~ 570 nm. Sample temperature can also be controlled from ~ 100K to ~ 600K, which enables the exploring the interaction of water ice and other volatiles with refractory samples. We have measured the UV spectra of many carbonaceous chondrites, including Mokoia, Vigarano, Warrenton, Orgueil, SaU290, and Essebi. In addition to being dark, some also possess on OMCT band. We have also obtained IR measurement of these meteorites to explore possible correlations between their UV and IR spectral signatures. In addition, we have also measured the UV spectra of low water content lunar analog glasses and have found a correlation between the spectral nature of the OMCT band and the abundance of iron [3]. Also, the spectral signature of mineralic and adsorbed water in the UV has been investigated. While water-ice has a known strong absorption feature near 180 nm (e.g. 4], adsorbed molecular and disassociatively adsorbed OH appear to not be optically active in this spectral region [5]. References: [1] Wagner et al. (1987) Icarus, 69, 14-28.1987; [2] Cloutis et al. (2008) Icarus, 197, 321-347; [3] Greenspon et al. (2012), 43rd LPSC

Comets as parent bodies of CI1 carbonaceous meteorites and possible habitats of ice-microbes

Science.gov (United States)

Wickramasinghe, N. Chandra; Wickramasinghe, Janaki T.; Wallis, Jamie; Hoover, Richard B.; Rozanov, Alexei Y.

2011-10-01

Recent studies of comets and cometary dust have confirmed the presence of biologically relevant organic molecules along with clay minerals and water ice. It is also now well established by deuterium/hydrogen ratios that the CI1 carbonaceous meteorites contain indigenous extraterrestrial water. The evidence of extensive aqueous alteration of the minerals in these meteorites led to the hypothesis that water-bearing asteroids or comets represent the parent bodies of the CI1 (and perhaps CM2) carbonaceous meteorites. These meteorites have also been shown to possess a diverse array of complex organics and chiral and morphological biomarkers. Stable isotope studies by numerous independent investigators have conclusively established that the complex organics found in these meteorites are both indigenous and extraterrestrial in nature. Although the origin of these organics is still unknown, some researchers have suggested that they originated by unknown abiotic mechanisms and may have played a role in the delivery of chiral biomolecules and the origin of life on Early Earth. In this paper we review these results and investigate the thermal history of comets. We show that permanent as well as transient domains of liquid water can be maintained on a comet under a plausible set of assumptions. With each perihelion passage of a comet volatiles are preferentially released, and during millions of such passages the comet could shed crustal debris that may survive transit through the Earth's atmosphere as a carbonaceous meteorite. We review the current state of knowledge of comets and carbonaceous meteorites. We also present the results of recent studies on the long-term viability of terrestrial ice-microbiota encased in ancient glacial ice and permafrost. We suggest that the conditions which have been observed to prevail on many comets do not preclude either survivability (or even the active metabolism and growth) of many types of eukaryotic and prokaryotic microbial

Comets as Parent Bodies of CI1 Carbonaceous Meteorites and Possible Habitats of Ice-Microbiota

Science.gov (United States)

Wickramasinghe, N. Chandra; Wallis, Daryl H.; Rozanov, Alexei Yu.; Hoover, Richard B.

2011-01-01

Recent studies of comets and cometary dust have confirmed the presence of biologically relevant organic molecules along with clay minerals and water ice. It is also now well established by deuterium/hydrogen ratios that the CI1 carbonaceous meteorites contain indigenous extraterrestrial water. The evidence of extensive aqueous alteration of the minerals in these meteorites led to the hypothesis that water-bearing asteroids or comets represent the parent bodies of the CI1 (and perhaps CM2) carbonaceous meteorites. These meteorites have also been shown to possess a diverse array of complex organics and chiral and morphological biomarkers. Stable isotope studies by numerous independent investigators have conclusively established that the complex organics found in these meteorites are both indigenous and extraterrestrial in nature. Although the origin of these organics is still unknown, some researchers have suggested that they originated by unknown abiotic mechanisms and may have played a role in the delivery of chiral biomolecules and the origin of life on Early Earth. In this paper we review these results and investigate the thermal history of comets. We show that permanent as well as transient domains of liquid water can be maintained on a comet under a plausible set of assumptions. With each perihelion passage of a comet volatiles are preferentially released, and during millions of such passages the comet could shed crustal debris that may survive transit through the Earth s atmosphere as a carbonaceous meteorite. We review the current state of knowledge of comets and carbonaceous meteorites. We also present the results of recent studies on the long-term viability of terrestrial ice-microbiota encased in ancient glacial ice and permafrost. We suggest that the conditions which have been observed to prevail on many comets do not preclude either survivability (or even the active metabolism and growth) of many types of eukaryotic and prokaryotic microbial

Influence of hydrothermal carbonization and treatment by microwave on morphology of carbonaceous materials obtained from lignin; Influencia da carbonizacao hidrotermica e do tratamento por microondas na morfologia de materiais carbonaceos obtidos de lignina

Energy Technology Data Exchange (ETDEWEB)

Oliveira, I.B.; Barin, G.B.; Barreto, L.S.; Santos, M.C.G., E-mail: iara.negreti18@gmail.com [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil)

2014-07-01

The conversion of biomass into carbon materials with special morphologies via hydrothermal carbonization presents itself as a potential route for the use of renewable precursors in obtaining carbonaceous structures. In the present study the influence of the hydrothermal carbonization (250 ° C / 4 h) followed by microwave treatment (1-2-4 hours at 25 and 40 mL) in morphology and structure of lignin. The samples were analyzed by X-ray diffraction and scanning electron microscopy. The plaque morphology of lignin was preserved during the hydrothermal process. However, when treated by microwave can be observed partial dissolution of lignin leading to the formation of microspheres on the surface. XRD presence of an amorphous halo 2θ = 23 ° attributed to the (002) network of the amorphous carbon was observed. (author)

Sources of carbonaceous aerosol in the Amazon basin

Directory of Open Access Journals (Sweden)

S. Gilardoni

2011-03-01

Full Text Available The quantification of sources of carbonaceous aerosol is important to understand their atmospheric concentrations and regulating processes and to study possible effects on climate and air quality, in addition to develop mitigation strategies.

In the framework of the European Integrated Project on Aerosol Cloud Climate Interactions (EUCAARI fine (D_p < 2.5 μm and coarse (2.5 μm < D_p <10 μm aerosol particles were sampled from February to June (wet season and from August to September (dry season 2008 in the central Amazon basin. The mass of fine particles averaged 2.4 μg m⁻³ during the wet season and 4.2 μg m⁻³ during the dry season. The average coarse aerosol mass concentration during wet and dry periods was 7.9 and 7.6 μg m⁻³, respectively. The overall chemical composition of fine and coarse mass did not show any seasonality with the largest fraction of fine and coarse aerosol mass explained by organic carbon (OC; the average OC to mass ratio was 0.4 and 0.6 in fine and coarse aerosol modes, respectively. The mass absorbing cross section of soot was determined by comparison of elemental carbon and light absorption coefficient measurements and it was equal to 4.7 m² g⁻¹ at 637 nm. Carbon aerosol sources were identified by Positive Matrix Factorization (PMF analysis of thermograms: 44% of fine total carbon mass was assigned to biomass burning, 43% to secondary organic aerosol (SOA, and 13% to volatile species that are difficult to apportion. In the coarse mode, primary biogenic aerosol particles (PBAP dominated the carbonaceous aerosol mass. The results confirmed the importance of PBAP in forested areas.

The source apportionment results were employed to evaluate the ability of global chemistry transport models to simulate carbonaceous aerosol sources in a regional tropical background site. The comparison showed an overestimation

Carbon isotope analysis of carbonaceous compounds in Puget Sound and Lake Washington

International Nuclear Information System (INIS)

Swanson, J.R.

1980-01-01

A new method has been developed and tested for determining chronological profiles of organic pollutants. This method, Carbon Isotope Analysis (CIA), involves measurements of 12 C, 13 C and 14 C in carbonaceous compounds found in layers of sediment. Lipids, total aliphatic hydrocarbons (TAHs) and polycyclic aromatic hydrocarbons (PAHs) are separated from kg quantities of sediment. Large Soxhlet extractors are used to remove the extractable organics, using ultra-pure benzene-methanol solution and having an extraction efficiency of about 86% for compounds with boiling points higher than n-tetradecane (n-C 14 ). The basic steps in compound separation include freeze-drying, extraction, fractionation, column chromatography and evaporation. Isolating the TAH and PAH fractions is accomplished by eluting samples from Sephadex and alumina/silica-gel columns. The amount of each fraction recovered is determined by converting the hydrocarbons to carbon dioxide and measuring this gas manometrically. Variations in 12 C and 13 C abundances for carbonaceous compounds are primarily due to thermodynamic, photosynthetic and metabolic fractionation processes. Thus, the source of a particular organic compound can often be determined by measuring its 13 C/ 12 C ratio. Combining the information from both the 13 C analysis and 14 C analysis makes source identification more certain. In addition, this investigation reviews carbon isotopic data and carbon cycling and analyzes organic pollution in two limited ecosystems (Puget Sound and Lake Washington). Specifically, distinct carbonaceous species are analyzed for pollution in sediments of Lake Washington, Elliott Bay, Commencement Bay, central Puget Sound and northern Puget Sound near the Cherry Point oil refineries

Graphite and carbonaceous materials in a molten salt nuclear reactor

International Nuclear Information System (INIS)

Rousseau, Ginette; Lecocq, Alfred; Hery, Michel.

1982-09-01

A project for a molten salt 1000 MWe reactor is studied by EDF-CEA teams. The design provides for a chromesco 3 vessel housing graphite structures in which the salt circulates. The salt (Th, U, Be and Li fluorides) is cooled by direct contact with lead. The graphites and carbonated materials, inert with respect to lead and the fuel salt, are being considered not only as moderators, but as reflectors and in the construction of the sections where the heat exchange takes place. On the basis of the problems raised in the operation of the reactor, a study programme on French experimental materials (Le Carbone Lorraine, SERS, SEP) has been defined. Hence, depending on the function or functions that the material is to ensure in the structure, the criteria of choice which follow will have to be examined: behaviour under irradiation, insertion of a fluid in the material, thermal properties required, mechanical properties required, utilization [fr

Inner Surface Chirality of Single-Handed Twisted Carbonaceous Tubular Nanoribbons.

Science.gov (United States)

Liu, Dan; Li, Baozong; Guo, Yongmin; Li, Yi; Yang, Yonggang

2015-11-01

Single-handed twisted 4,4'-biphenylene-bridged polybissilsesquioxane tubular nanoribbons and single-layered nanoribbons were prepared by tuning the water/ethanol volume ratio in the reaction mixture at pH = 11.6 through a supramolecular templating approach. The single-layered nanoribbons were formed by shrinking tubular nanoribbons after the removal of the templates. In addition, solvent-induced handedness inversion was achieved. The handedness of the polybissilsesquioxanes could be controlled by changing the ethanol/water volume ratio in the reaction mixture. After carbonization at 900 °C for 4.0 h and removal of silica, single-handed twisted carbonaceous tubular nanoribbons and single-layered nanoribbons with micropores in the walls were obtained. X-ray diffraction and Raman spectroscopy analyses indicated that the carbon is predominantly amorphous. The circular dichroism spectra show that the twisted tubular nanoribbons exhibit optical activity, while the twisted single-layered nanoribbons do not. The results shown here indicate that chirality is transferred from the organic self-assemblies to the inner surfaces of the 4,4'-biphenylene-bridged polybissilsesquioxane tubular nanoribbons and subsequently to those of the carbonaceous tubular nanoribbons. © 2015 Wiley Periodicals, Inc.

Carbonaceous matter in the Pomozhan deposit

Energy Technology Data Exchange (ETDEWEB)

Piatek, G

1979-01-01

Carbonaceous matter (CM), encountered in the Pomozhan deposit, is coordinate to dolomitic-illitic clay, filling caverns in ore-bearing dolomites. The CM represents a disperse mass with particle sizes up to 2 mm, having a color from dark brown to black. The reflectivity (0.35-0.42%) and classification assignment of the CM to macerals of the vitrinite or dopplerinite group were determined by micropetrographic methods. CM belonging to the type of humic coals, transitional from brown to bituminous coals is an epigenetic formation. Its accumulation in the regions of the Ol'kush ore deposits occurred in the Triassic-Cretaceous or Cenozoic interval. Liassic coal of the Zavertse region or Helvetian coal of Khomentuv and Tarnobzheg could be the source of the CM.

Kinetics of the hydrothermal treatment of tannin for producing carbonaceous microspheres.

Science.gov (United States)

Braghiroli, F L; Fierro, V; Izquierdo, M T; Parmentier, J; Pizzi, A; Celzard, A

2014-01-01

Aqueous solutions of condensed tannins were submitted to hydrothermal carbonization (HTC) in a stainless steel autoclave, and the kinetics of hydrothermal carbon formation was investigated by changing several parameters: amount of tannin (0.5; 1.0; 1.5; 2.0 g in 16 mL of water), HTC temperature (130, 160, 180 and 200°C) and reaction times (from 1 to 720 h). The morphology and the structure of the tannin-based hydrothermal carbons were studied by TEM, krypton adsorption at -196°C and helium pycnometry. These materials presented agglomerated spherical particles, having surface areas ranging from 0.6 to 10.0 m(2) g(-1). The chemical composition of the hydrothermal carbons was found to be constant and independent of reaction time. HTC kinetics of tannin were determined and shown to correspond to first-order reaction. Temperature-dependent measurements led to an activation energy of 91 kJ mol(-1) for hydrothermal conversion of tannin into carbonaceous microspheres separable by centrifugation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Distilling carbonaceous material

Energy Technology Data Exchange (ETDEWEB)

Karrick, L C

1926-11-02

Coal, shale and the like are distilled in a current of superheated steam which is passed into a retort at about midway between its ends a further supply being if necessary introduced at the bottom to generate water-gas, and the coke being dry quenched in a hopper below the retort. Combustion products may also be introduced and the temperature may be varied from 950 to 1725/sup 0/F, oil, gas, resin and a residual coke having good adsorbent value, being obtained. The charge from hoppers and auxiliary hoppers is fed to retorts situated between gas and steam preheaters, the rate of downward movement being controlled by discharge rollers having arms, counterweighted rocking arms allowing the residue to be fed downwards into hoppers. Steam from a pipe is superheated in horizontal passages, and admitted through ports into the retort. Preheated fuel gas is burnt in combustion flues and passes down through vertical flues, across horizontal flues and up flues adjacent the retorts, from which by ports and flues it passes down a chamber having an air or gas preheater each having two independent systems, one discharging into the combustion chamber beneath it and the other into an adjacent chamber. Air or gas enters by pipes and after being heated in pipes is fed by ports to the chamber. The volatiles pass off through outlets leading to a main air cooled condenser and a water-cooled condenser delivering to a separating tank connecting with pipes for quenching the residues and with pipes to preheat the charge in the hoppers and maintain a gas barrier the rein. Superheated steam may also be admitted through ports to generate water-gas and increase the total volume of gases and combustion products may be introduced through ports. The upper part of the retort is made of cast iron, the high temperature parts of silica or carborundum brick, and the lower part of chrome iron or other metal.

Effects of day-of-week trends and vehicle types on PM{sub 2.5}-bounded carbonaceous compositions

Energy Technology Data Exchange (ETDEWEB)

Pongpiachan, Siwatt, E-mail: pongpiajun@gmail.com [NIDA Center for Research & Development of Disaster Prevention & Management, School of Social and Environmental Development, National Institute of Development Administration (NIDA), 118 Moo 3, Sereethai Road, Klong-Chan, Bangkapi, Bangkok 10240 (Thailand); SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences (IEECAS), Xi' an 710075 (China); Kositanont, Charnwit [Department of Microbiology, Faculty of Sciences, Chulalongkorn University, Bangkok 10330 (Thailand); Palakun, Jittree [Faculty of Education, Valaya Alongkorn Rajabhat University under the Royal Patronage (VRU), No.1 Moo 20, Phaholyothin Road, Klong luang, Pathumthani 13180 (Thailand); Liu, Suixin; Ho, Kin Fai; Cao, Junji [SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences (IEECAS), Xi' an 710075 (China)

2015-11-01

Carbonaceous compositions of PM{sub 2.5} were measured in the heart of Bangkok from 17th November 2010 to 19th January 2012, and a data set of 94 samples was constructed. Effects of day-of-week trends and vehicle types on PM{sub 2.5}-bound TC, OC, and EC were carefully investigated. In this study, OC was the most important contributor to the total PM{sub 2.5} mass concentration. The average PM{sub 2.5}-bound OC content measured at CHAOS (18.8 ± 9.18 μg m{sup −3}) was approximately 11 times higher than at Chaumont, Switzerland (1.7 μg m{sup −3}), but approximately five times lower than at Xi'an, China (93.0 μg m{sup −3}). The application of diagnostic binary ratios of OC/EC and estimations of secondary organic carbon (SOC) coupled with autocorrelation plots (Box and Jenkins) highlight the enhanced impacts of traffic emissions, especially from diesel vehicles, on PM{sub 2.5}-bound carbonaceous compositions on weekdays relative to weekends. Hierarchical cluster analysis (HCA) coupled with principal component analysis (PCA) underline the importance of diesel emissions as the primary contributors of carbonaceous aerosols, particularly during weekdays. - Highlights: • Traffic emissions play an important role in governing OC and EC during weekdays. • Time series analysis shows the existence of day-of-week trends of OC and EC. • Diesel vehicles are the main contributors of carbonaceous compositions.

Petrography of the carbonaceous, diamond-bearing stone "Hypatia" from southwest Egypt: A contribution to the debate on its origin

Science.gov (United States)

Belyanin, Georgy A.; Kramers, Jan D.; Andreoli, Marco A. G.; Greco, Francesco; Gucsik, Arnold; Makhubela, Tebogo V.; Przybylowicz, Wojciech J.; Wiedenbeck, Michael

2018-02-01

The stone named "Hypatia" found in the Libyan Desert Glass area of southwest Egypt is carbon-dominated and rich in microdiamonds. Previous noble gas and nitrogen isotope studies suggest an extraterrestrial origin. We report on a reconnaissance study of the carbonaceous matrix of this stone and the phases enclosed in it. This focused on areas not affected by numerous transecting fractures mostly filled with secondary minerals. The work employed scanning electron microscopy (SEM) with energy-dispersive (EDS) and wavelength-dispersive (WDS) electron microprobe (EMPA) analysis, Proton Induced X-ray Emission (PIXE) spectrometry and micro-Raman spectroscopy. We found that carbonaceous matrices of two types occur irregularly intermingled on the 50-500 μm scale: Matrix-1, consisting of almost pure carbonaceous matter, and Matrix-2, containing Fe, Ni, P and S at abundances analyzable by microprobe. Matrix-2 contains the following phases as inclusions: (i) (Fe,Ni) sulphide occurring in cloud-like concentrations of sub-μm grains, in domains of the matrix that are enriched in Fe and S. These domains have (Fe + Ni)/S (atomic) = 1.51 ± 0.24 and Ni/Fe = 0.086 ± 0.061 (both 1SD); (ii) grains up to ∼5 μm in size of moissanite (SiC); (iii) Ni-phosphide compound grains up to 60 μm across that appear cryptocrystalline or amorphous and have (Ni + Fe)/P (atomic) = 5.6. ± 1.7 and Ni/Fe = 74 ± 29 (both 1SD), where both these ratios are much higher than any known Ni-phosphide minerals; (iv) rare grains (observed only once) of graphite, metallic Al, Fe and Ag, and a phase consisting of Ag, P and I. In Matrix-2, Raman spectroscopy shows a prominent narrow diamond band at 1340 cm-1. In Matrix-1 the D and G bands of disordered carbon are dominant, but a minor diamond band is ubiquitous, accounting for the uniform hardness of the material. The D and G bands have average full width at half maximum (FWHM) values of 295 ± 19 and 115 ± 19 cm-1, respectively, and the D/G intensity ratio

Production of carbonaceous materials with various lengths in small spheroidal fullerenes and long CNTs by tunable multi-walled carbon nanotube cutting

Energy Technology Data Exchange (ETDEWEB)

Kim, Seung Hoi; Shin, Ueon Sang [Dankook University, Cheonan (Korea, Republic of)

2016-10-15

Tunable cutting of multi-walled carbon nanotubes (CNTs) using high pressure homogenizer and/or HNO{sub 3}/H{sub 2}SO{sub 4} solution was accomplished, resulting in the production of short CNTs with minimum length of 35 nm. Field emission scanning electron microscopy (FE-SEM) and Zeta sizer analysis showed significant reduction of CNT length from this tunable cutting (e.g. from long and entangled pristine CNTs at about 20 μm to ≥1000 nm, ⁓400 nm, ⁓200 nm, and ⁓100 nm via high pressure jet-spraying cutting within 5 h, while chemical cutting process using greatly longer hours (48 h) showed a reduction only to about 1000 nm). When CNT sample of average 1000 nm length previously shortened by HNO{sub 3}/H{sub 2}SO{sub 4} was subjected to the high pressure jet-spraying cutting process, the reduction progressed faster (≤1 h), producing ≥35 nm. Fourier transform infrared spectra and thermogravimetric analysis (TGA) indicated restricted formation of hydrophilic functional groups such as carboxylic group and hydroxyl group in the high pressure jet-spraying cutting, whereas an intensive formation of hydrophilic functional groups on the surface of shortened CNT samples was found after chemical cutting. Such short CNT samples would fulfill the requirements for carbonaceous materials with various lengths in small spheroidal fullerenes and long CNTs. The short CNTs produced are promising for scientific and technological applications in many fields such as electronics, diagnostics, pharmaceuticals, biomedical engineering, and environmental or energy industries.

Atmospheric carbonaceous aerosols from Indo-Gangetic Plain and Central Himalaya: impact of anthropogenic sources.

Science.gov (United States)

Ram, Kirpa; Sarin, M M

2015-01-15

In the present-day scenario of growing anthropogenic activities, carbonaceous aerosols contribute significantly (∼20-70%) to the total atmospheric particulate matter mass and, thus, have immense potential to influence the Earth's radiation budget and climate on a regional to global scale. In addition, formation of secondary organic aerosols is being increasingly recognized as an important process in contributing to the air-pollution and poor visibility over urban regions. It is, thus, essential to study atmospheric concentrations of carbonaceous species (EC, OC and WSOC), their mixing state and absorption properties on a regional scale. This paper presents the comprehensive data on emission sources, chemical characteristics and optical properties of carbonaceous aerosols from selected urban sites in the Indo-Gangetic Plain (IGP) and from a high-altitude location in the central Himalaya. The mass concentrations of OC, EC and WSOC exhibit large spatio-temporal variability in the IGP. This is attributed to seasonally varying emissions from post-harvest agricultural-waste burning, their source strength, boundary layer dynamics and secondary aerosol formation. The high concentrations of OC and SO4(2-), and their characteristic high mass scattering efficiency, contribute significantly to the aerosol optical depth and scattering coefficient. This has implications to the assessment of single scattering albedo and aerosol radiative forcing on a regional scale. Copyright © 2014 Elsevier Ltd. All rights reserved.

Distinct Purine Distribution in Carbonaceous Chondrites

Science.gov (United States)

Callahan, Michael P.; Smith, Karen E.; Cleaves, Henderson J.; Ruzicka, Josef; Stern, Jennifer C.; Glavin, Daniel P.; House, Christopher H.; Dworkin, Jason P.

2011-01-01

Carbonaceous chondrite meteorites are known to contain a diverse suite of organic compounds, many of which are essential components of biochemistry. Amino acids, which are the monomers of proteins, have been extensively studied in such meteorites (e.g. Botta and Bada 2002; Pizzarello et aI., 2006). The origin of amino acids in meteorites has been firmly established as extraterrestrial based on their detection typically as racemic mixtures of amino acids, the presence of many non-protein amino acids, and non-terrestrial values for compound-specific deuterium, carbon, and nitrogen isotopic measurements. In contrast to amino acids, nucleobases in meteorites have been far less studied. Nucleobases are substituted one-ring (pyrimidine) or two-ring (purine) nitrogen heterocyclic compounds and serve as the information carriers of nucleic acids and in numerous coenzymes. All of the purines (adenine, guanine, hypoxanthine, and xanthine) and pyrimidines (uracil) previously reported in meteorites are biologically common and could be interpreted as the result of terrestrial contamination (e.g. van del' Velden and Schwartz, 1974.) Unlike other meteoritic organics, there have been no observations of stochastic molecular diversity of purines and pyrimidines in meteorites, which has been a criterion for establishing extraterrestrial origin. Maltins et al. (2008) performed compound-specific stable carbon isotope measurements for uracil and xanthine in the Murchison meteorite. They assigned a non-terrestrial origin for these nucleobases; however, the possibility that interfering indigenous molecules (e.g. carboxylic acids) contributed to the 13C-enriched isotope values for these nucleobases cannot be completely ruled out. Thus, the origin of these meteoritic nucleobases has never been established unequivocally. Here we report on our investigation of extracts of II different carbonaceous chondrites covering various petrographic types (Cl, CM, and CR) and degrees of aqueous alteration

Characterization of Chiral Carbonaceous Nanotubes Prepared from Four Coiled Tubular 4,4'-biphenylene-silica Nanoribbons

Directory of Open Access Journals (Sweden)

Shuwei Lin

2014-04-01

Full Text Available Four dipeptides derived from phenylalanine were synthesized, which can self-assemble into twisted nanoribbon in deionized water. The handedness of the organic self-assemblies was controlled by the chirality of the phenylalanine at the terminals. Coiled 4,4'-biphenylene bridged polybissilsesquioxane tubular nanoribbons were prepared using the organic self-assemblies as the templates. The circular dichroism spectra indicated that the biphenylene rings preferred to twist in one-handedness within the walls of the samples. After carbonization and removal of silica, single-handed coiled carbonaceous tubular nanoribbons were obtained. The Raman spectra indicated that the carbon was amorphous. The diffuse reflectance circular dichroism spectra indicated the tubular carbonaceous nanoribbons exhibited optical activity.

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

It is revealed that the noble metals phases occur as separate microsized grains, most of which have been indicated as Au–Ag–Hg amalgam and rarely as Pt-rich compounds. The obtained data can be mainly used to advance technologies for manufacturing carbide-based composite materials from natural carbonaceous ...

Solar-Radiation Heating as a Possible Heat Source for Dehydration of Hydrous Carbonaceous Chondrites

Science.gov (United States)

Nakamura, T.; Golabek, G.; Ohtsuka, K.; Matsuoka, M.

2017-07-01

We have calculated time-dependent temperature profiles of near surface layers of primitive Near Sun Asteroid (3200) Phaethon and found that solar radiation heating is a possible heat source for dehydration of carbonaceous chondrites.

Carbon offers advantages as implant material in human body

Science.gov (United States)

Benson, J.

1969-01-01

Because of such characteristics as high strength and long-term biocompatability, aerospace carbonaceous materials may be used as surgical implants to correct pathological conditions in the body resulting from disease or injury. Examples of possible medical uses include bone replacement, implantation splints and circulatory bypass implants.

Organic Chemistry of Carbonaceous Meteorites

Science.gov (United States)

Cronin, John R.

2001-01-01

Chiral and carbon-isotopic analyses of isovaline have been carried out on numerous samples of the Murchison and one sample of the Murray carbonaceous chondrite. The isovaline was found to be heterogeneous with regard to enantiomeric excess (ee) both between samples and within a single Murchison sample. L-Excesses ranging from 0 to 15% were observed. The isovaline delta(sup 13) C was found to be about +18%. No evidence was obtained suggesting terrestrial contamination in the more abundant L-enantiomer. A correlation was observed between isovaline (also alpha - aminoisobutyric acid) concentration and PCP content of five CM chondrites. It is suggested that isovaline, along with other meteoritic a-methyl amino acids with ee, are of presolar origin. The possible formation of ee in extraterrestrial amino acids by exposure to circularly polarized light or by magnetochiral photochemistry is discussed. Key words: Murchison meteorite, Murray meteorite, amino acids, isovaline, chirality, carbon isotopes, PCP.

Black liquor-derived carbonaceous solid acid catalyst for the hydrolysis of pretreated rice straw in ionic liquid.

Science.gov (United States)

Bai, Chenxi; Zhu, Linfeng; Shen, Feng; Qi, Xinhua

2016-11-01

Lignin-containing black liquor from pretreatment of rice straw by KOH aqueous solution was applied to prepare a carbonaceous solid acid catalyst, in which KOH played dual roles of extracting lignin from rice straw and developing porosity of the carbon material as an activation agent. The synthesized black liquor-derived carbon material was applied in catalytic hydrolysis of the residue solid from the pretreatment of rice straw, which was mainly composed of cellulose and hemicellulose, and showed excellent activity for the production of total reducing sugars (TRS) in ionic liquid, 1-butyl-3-methyl imidazolium chloride. The highest TRS yield of 63.4% was achieved at 140°C for 120min, which was much higher than that obtained from crude rice straw under the same reaction conditions (36.6% TRS yield). Overall, this study provides a renewable strategy for the utilization of all components of lignocellulosic biomass. Copyright © 2016 Elsevier Ltd. All rights reserved.

Thermal alteration in carbonaceous chondrites and implications for sublimation in rock comets

Science.gov (United States)

Springmann, Alessondra; Lauretta, Dante S.; Steckloff, Jordan K.

2015-11-01

Rock comets are small solar system bodies in Sun-skirting orbits (perihelion q CO2, etc.). B-class asteroid (3200) Phaethon, considered to be the parent body of the Geminid meteor shower, is the only rock comet currently known to periodically eject dust and form a coma. Thermal fracturing or thermal decomposition of surface materials may be driving Phaethon’s cometary activity (Li & Jewitt, 2013). Phaethon-like asteroids have dynamically unstable orbits, and their perihelia can change rapidly over their ~10 Myr lifetimes (de León et al., 2010), raising the possibility that other asteroids may have been rock comets in the past. Here, we propose using spectroscopic observations of mercury (Hg) as a tracer of an asteroid’s thermal metamorphic history, and therefore as a constraint on its minimum achieved perihelion distance.B-class asteroids such as Phaethon have an initial composition similar to aqueously altered primitive meteorites such as CI- or CM-type meteorites (Clark et al., 2010). Laboratory heating experiments of ~mm sized samples of carbonaceous chondrite meteorites from 300K to 1200K at a rate of 15K/minute show mobilization and volatilization of various labile elements at temperatures that could be reached by Mercury-crossing asteroids. Samples became rapidly depleted in labile elements and, in particular, lost ~75% of their Hg content when heated from ~500-700 K, which corresponds to heliocentric distances of ~0.15-0.3 au, consistent with our thermal models. Mercury has strong emission lines in the UV (~ 185 nm) and thus its presence (or absence) relative to carbonaceous chondrite abundances would indicate if these bodies had perihelia in their dynamical histories inside of 0.15 AU, and therefore may have previously been Phaethon-like rock comets. Future space telescopes or balloon-borne observing platforms equipped with a UV spectrometer could potentially detect the presence or absence of strong ultraviolet mercury lines on rock comets or rock

Pyrolitic carbon from biomass precursors as anode materials for lithium batteries

International Nuclear Information System (INIS)

Stephan, A. Manuel; Kumar, T. Prem; Ramesh, R.; Thomas, Sabu; Jeong, Soo Kyung; Nahm, Kee Suk

2006-01-01

Disordered carbonaceous materials were synthesized by the pyrolysis of banana fibers treated with pore-forming substances such as ZnCl 2 and KOH. X-ray diffraction studies indicated a carbon structure with a large number of disorganized single layer carbon sheets. Addition of porogenic agent led to remarkable changes in the structure and morphology of the carbonaceous products. The product obtained with ZnCl 2 treatment gave first-cycle lithium insertion and de-insertion capacities of 3325 and 400 mAh g -1 , respectively. Lower capacities only could be realized in the subsequent cycles, although the coulombic efficiency increased upon cycling, which in the 10th cycle was 95%

Uranium band types in carbonaceous sediments with different diagenesis levels

International Nuclear Information System (INIS)

Borstel, D. von.

1984-01-01

Uraniferous peats, lignites and coals were studied by chemical and geological methods in order to determine the influence of carbonaceous substances with different diagenesis levels on uranium enrichment in sediments. It was found that the main factor of deposit genesis is not the chemical bending of uranium to the organic substance but rather the reduction from mobile U(VI) to immobile U(IV) in the course of diagenesis to epigenesis. (orig./PW) [de

Uranium resources in fine-grained carbonaceous rocks of the Great Divide Basin, south-central Wyoming. National Uranium Resource Evaluation

International Nuclear Information System (INIS)

Burger, J.A.; Roe, L.M. II; Hacke, C.M.; Mosher, M.M.

1982-11-01

The uranium resources of the fine-grained carbonaceous rocks of the Great Divide Basin in southern Wyoming were assessed. The assessment was based primarily on data from some 600 boreholes. The data included information from geophysical logs, lithologic logs and cores, and drill cuttings. The cores and cuttings were analyzed for chemical U 3 O 8 , radiometric U, Th and trace elements. Selected samples were examined by thin section, sieve analysis, x-ray, SEM, ion probe, and alpha track methods. The uranium is associated with fine-grained carbonaceous shales, siltstones, mudstones, and coals in radioactive zones 5 to 50 ft thick that are continuous over broad areas. These rocks have a limited stratigraphic range between the Red Desert tongue of the Wasatch Formation and the lower part of the Tipton tongue of the Green River Formation. Most of this uranium is syngenetic in origin, in part from the chelation of the uranium by organic material in lake-side swamps and in part as uranium in very fine detrital heavy minerals. The uraniferous fine-grained carbonaceous rocks that exceed a cutoff grade of 100 ppM eU 3 O 8 extend over an area of 542 mi 2 and locally to a depth of approximately 2000 ft. The uraniferous area is roughly ellipical and embraces the zone of change between the piedmont and alluvial-fan facies and the lacustrine facies of the intertonguing Battle Spring, Wasatch, and Green River Formations. About 1.05 x 10 6 tons U 3 O 8 , based on gross-gamma logs not corrected for thorium, are assigned to the area in the first 500 ft; an estimated 3.49 x 10 6 tons are assigned to a depth of 1000 ft. These units also contain a substantial thorium resource that is also associated with fine-grained rocks. The thorium-to-uranium ratio generally ranges between 1 and 4. A thorium resource of 3.43 x 10 6 tons to a depth of 500 ft is estimated for the assessment area. 5 figures, 3 tables

Results of high-temperature processing of high-carbon materials from the lower cambrian period of the Earth's history

International Nuclear Information System (INIS)

Maslov, O.D.

2016-01-01

The paper reports on the observation of spontaneous fission of nuclides, concentrated in fly ash during the combustion of high-carbon (graphite) material, chemogenic siliceous-carbonaceous rocks and carbonaceous shale in the mixture with brown coal. In the samples obtained, the spontaneous fission was measured by track method. The zones of precipitation of spontaneous fission of nuclides and their lighter homologues on thermochromatographic column were determined. A nuclide with a half-life of 62 d was detected in the alkaline trap. The chemical treatment procedure included co-precipitation with iron hydroxide, dissolution in NH 4 OH + H 2 O 2 solution and distillation by heating up to 100°C followed by AgI co-precipitation. Based on the chemical behavior it can be concluded that the detected radionuclide belongs to the halides. The content of the parent nuclide in high-carbon (graphite) material and chemogenic siliceous-carbonaceous rock corresponds to 10 -14 g/g. [ru

Nitrile versus isonitrile adsorption at interstellar grain surfaces. II. Carbonaceous aromatic surfaces

Science.gov (United States)

Bertin, M.; Doronin, M.; Michaut, X.; Philippe, L.; Markovits, A.; Fillion, J.-H.; Pauzat, F.; Ellinger, Y.; Guillemin, J.-C.

2017-12-01

Context. Almost 20% of the 200 different species detected in the interstellar and circumstellar media present a carbon atom linked to nitrogen by a triple bond. Of these 37 molecules, 30 are nitrile R-CN compounds, the remaining 7 belonging to the isonitrile R-NC family. How these species behave in their interactions with the grain surfaces is still an open question. Aims: In a previous work, we have investigated whether the difference between nitrile and isonitrile functional groups may induce differences in the adsorption energies of the related isomers at the surfaces of interstellar grains of various nature and morphologies. This study is a follow up of this work, where we focus on the adsorption on carbonaceous aromatic surfaces. Methods: The question is addressed by means of a concerted experimental and theoretical approach of the adsorption energies of CH3CN and CH3NC on the surface of graphite (with and without surface defects). The experimental determination of the molecule and surface interaction energies is carried out using temperature-programmed desorption in an ultra-high vacuum between 70 and 160 K. Theoretically, the question is addressed using first-principle periodic density functional theory to represent the organised solid support. Results: The adsorption energy of each compound is found to be very sensitive to the structural defects of the aromatic carbonaceous surface: these defects, expected to be present in a large numbers and great diversity on a realistic surface, significantly increase the average adsorption energies to more than 50% as compared to adsorption on perfect graphene planes. The most stable isomer (CH3CN) interacts more efficiently with the carbonaceous solid support than the higher energy isomer (CH3NC), however.

Distilling peat and other carbonaceous matters

Energy Technology Data Exchange (ETDEWEB)

Stones, W B

1850-03-07

Improvements in treating peat and other carbonaceous and ligneous matters, so as to obtain products therefrom are disclosed. These improvements consist, first, of a machine for compressing and partially drying peat. The unpressed peat is put into boxes and these into frames which are passed through between the bowls of a machine resembling a pair of squeezers. Secondly, consists in distilling, at a temperature of, say 700/sup 0/F, the compressed peat, with or without the addition of tar or fatty matter in retorts, and condensing the vapors in a series of vessels, arranged after the manner of Wolfe's bottles. The resulting charcoal may be extinguished by passing carbonic acid through it while in an air-tight box or chamber, and it may then be compressed into bricks, and used for locomotives and other purposes.

PROTO-PLANETARY DISK CHEMISTRY RECORDED BY D-RICH ORGANIC RADICALS IN CARBONACEOUS CHONDRITES

International Nuclear Information System (INIS)

Remusat, Laurent; Robert, Francois; Meibom, Anders; Mostefaoui, Smail; Delpoux, Olivier; Binet, Laurent; Gourier, Didier; Derenne, Sylvie

2009-01-01

Insoluble organic matter (IOM) in primitive carbonaceous meteorites has preserved its chemical composition and isotopic heterogeneity since the solar system formed ∼4.567 billion years ago. We have identified the carrier moieties of isotopically anomalous hydrogen in IOM isolated from the Orgueil carbonaceous chondrite. Data from high spatial resolution, quantitative isotopic NanoSIMS mapping of Orgueil IOM combined with data from electron paramagnetic resonance spectroscopy reveals that organic radicals hold all the deuterium excess (relative to the bulk IOM) in distinct, micrometer-sized, D-rich hotspots. Taken together with previous work, the results indicate that an isotopic exchange reaction took place between pre-existing organic compounds characterized by low D/H ratios and D-rich gaseous molecules, such as H 2 D + or HD 2 + . This exchange reaction most likely took place in the diffuse outer regions of the proto-planetary disk around the young Sun, offering a model that reconciles meteoritic and cometary isotopic compositions of organic molecules.

Proto-Planetary Disk Chemistry Recorded by D-Rich Organic Radicals in Carbonaceous Chondrites

Science.gov (United States)

Remusat, Laurent; Robert, François; Meibom, Anders; Mostefaoui, Smail; Delpoux, Olivier; Binet, Laurent; Gourier, Didier; Derenne, Sylvie

2009-06-01

Insoluble organic matter (IOM) in primitive carbonaceous meteorites has preserved its chemical composition and isotopic heterogeneity since the solar system formed ~4.567 billion years ago. We have identified the carrier moieties of isotopically anomalous hydrogen in IOM isolated from the Orgueil carbonaceous chondrite. Data from high spatial resolution, quantitative isotopic NanoSIMS mapping of Orgueil IOM combined with data from electron paramagnetic resonance spectroscopy reveals that organic radicals hold all the deuterium excess (relative to the bulk IOM) in distinct, micrometer-sized, D-rich hotspots. Taken together with previous work, the results indicate that an isotopic exchange reaction took place between pre-existing organic compounds characterized by low D/H ratios and D-rich gaseous molecules, such as H2D+ or HD2 +. This exchange reaction most likely took place in the diffuse outer regions of the proto-planetary disk around the young Sun, offering a model that reconciles meteoritic and cometary isotopic compositions of organic molecules.

Atmospheric pressure MALDI for the noninvasive characterization of carbonaceous ink from Renaissance documents.

Science.gov (United States)

Grasso, Giuseppe; Calcagno, Marzia; Rapisarda, Alessandro; D'Agata, Roberta; Spoto, Giuseppe

2017-06-01

The analytical methods that are usually applied to determine the compositions of inks from ancient manuscripts usually focus on inorganic components, as in the case of iron gall ink. In this work, we describe the use of atmospheric pressure/matrix-assisted laser desorption ionization-mass spectrometry (AP/MALDI-MS) as a spatially resolved analytical technique for the study of the organic carbonaceous components of inks used in handwritten parts of ancient books for the first time. Large polycyclic aromatic hydrocarbons (L-PAH) were identified in situ in the ink of XVII century handwritten documents. We prove that it is possible to apply MALDI-MS as a suitable microdestructive diagnostic tool for analyzing samples in air at atmospheric pressure, thus simplifying investigations of the organic components of artistic and archaeological objects. The interpretation of the experimental MS results was supported by independent Raman spectroscopic investigations. Graphical abstract Atmospheric pressure/MALDI mass spectrometry detects in situ polycyclic aromatic hydrocarbons in the carbonaceous ink of XVII century manuscripts.

Purity Evaluation of Bulk Single Wall Carbon Nanotube Materials

International Nuclear Information System (INIS)

Dettlaff-Weglikowska, U.; Hornbostel, B.; Cech, J.; Roth, S.; Wang, J.; Liang, J.

2005-01-01

We report on our experience using a preliminary protocol for quality control of bulk single wall carbon nanotube (SWNT) materials produced by the electric arc-discharge and laser ablation method. The first step in the characterization of the bulk material is mechanical homogenization. Quantitative evaluation of purity has been performed using a previously reported procedure based on solution phase near-infrared spectroscopy. Our results confirm that this method is reliable in determining the nanotube content in the arc-discharge sample containing carbonaceous impurities (amorphous carbon and graphitic particles). However, the application of this method to laser ablation samples gives a relative purity value over 100 %. The possible reason for that might be different extinction coefficient meaning different oscillator strength of the laser ablation tubes. At the present time, a 100 % pure reference sample of laser ablation SWNT is not available, so we chose to adopt the sample showing the highest purity as a new reference sample for a quantitative purity evaluation of laser ablation materials. The graphitic part of the carbonaceous impurities has been estimated using X-ray diffraction of 1:1 mixture of nanotube material and C60 as an internal reference. To evaluate the metallic impurities in the as prepared and homogenized carbon nanotube soot inductive coupled plasma (ICP) has been used

First Results of the “Carbonaceous Aerosol in Rome and Environs (CARE” Experiment: Beyond Current Standards for PM10

Directory of Open Access Journals (Sweden)

Francesca Costabile

2017-12-01

Full Text Available In February 2017 the “Carbonaceous Aerosol in Rome and Environs (CARE” experiment was carried out in downtown Rome to address the following specific questions: what is the color, size, composition, and toxicity of the carbonaceous aerosol in the Mediterranean urban background area of Rome? The motivation of this experiment is the lack of understanding of what aerosol types are responsible for the severe risks to human health posed by particulate matter (PM pollution, and how carbonaceous aerosols influence radiative balance. Physicochemical properties of the carbonaceous aerosol were characterised, and relevant toxicological variables assessed. The aerosol characterisation includes: (i measurements with high time resolution (min to 1–2 h at a fixed location of black carbon (eBC, elemental carbon (EC, organic carbon (OC, particle number size distribution (0.008–10 μ m, major non refractory PM1 components, elemental composition, wavelength-dependent optical properties, and atmospheric turbulence; (ii 24-h measurements of PM10 and PM2.5 mass concentration, water soluble OC and brown carbon (BrC, and levoglucosan; (iii mobile measurements of eBC and size distribution around the study area, with computational fluid dynamics modeling; (iv characterisation of road dust emissions and their EC and OC content. The toxicological assessment includes: (i preliminary evaluation of the potential impact of ultrafine particles on lung epithelia cells (cultured at the air liquid interface and directly exposed to particles; (ii assessment of the oxidative stress induced by carbonaceous aerosols; (iii assessment of particle size dependent number doses deposited in different regions of the human body; (iv PAHs biomonitoring (from the participants into the mobile measurements. The first experimental results of the CARE experiment are presented in this paper. The objective here is to provide baseline levels of carbonaceous aerosols for Rome, and to address

Origin of fine carbonaceous particulate matter in the Western Mediterranean Basin: fossil versus modern sources

Science.gov (United States)

Cruz Minguillón, María.; Perron, Nolwenn; Querol, Xavier; Szidat, Sönke; Fahrni, Simon; Wacker, Lukas; Reche, Cristina; Cusack, Michael; Baltensperger, Urs; Prévôt, André S. H.

2010-05-01

The present work was carried out in the frame of the international field campaign DAURE (Determination of the sources of atmospheric Aerosols in Urban and Rural Environments in the western Mediterranean). The objective of this campaign is to study the aerosol pollution episodes occurring at regional scale during winter and summer in the Western Mediterranean Basin. As part of this campaign, this work focuses on identifying the origin of fine carbonaceous aerosols. To this end, fine particulate matter (PM1) samples were collected during two different seasons (February-March and July 2009) at two sites: an urban site (Barcelona, NE Spain) and a rural European Supersite for Atmospheric Aerosol Research (Montseny, NE Spain). Subsequently, 14C analyses were carried out on these samples, both in the elemental carbon (EC) fraction and the organic carbon (OC) fraction, in order to distinguish between modern carbonaceous sources (biogenic emissions and biomass burning emissions) and fossil carbonaceous sources (mainly road traffic). Preliminary results from the winter period show that 40% of the OC at Barcelona has a fossil origin whereas at Montseny this percentage is 30%. These values can be considered as unexpected given the nature of the sites. Nevertheless, the absolute concentrations of fossil OC at Barcelona and Montseny differ by a factor of 2 (the first being higher), since the total OC at Montseny is lower than at Barcelona. Further evaluation of results and comparison with other measurements carried out during the campaign are required to better evaluate the origin of the fine carbonaceous matter in the Western Mediterranean Basin. Acknowledgements: Spanish Ministry of Education and Science, for a Postdoctoral Grant awarded to M.C. Minguillón in the frame of Programa Nacional de Movilidad de Recursos Humanos del Plan nacional de I-D+I 2008-2011. Spanish Ministry of Education and Science, for the Acción Complementaria DAURE CGL2007-30502-E/CLI.

Microfossils, biomolecules and biominerals in carbonaceous meteorites: implications to the origin of life

Science.gov (United States)

Hoover, Richard B.

2012-11-01

Environmental and Field Emission Scanning Electron Microscopy (ESEM and FESEM) investigations have shown that a wide variety of carbonaceous meteorites contain the remains of large filaments embedded within freshly fractured interior surfaces of the meteorite rock matrix. The filaments occur singly or in dense assemblages and mats and are often encased within carbon-rich, electron transparent sheaths. Electron Dispersive X-ray Spectroscopy (EDS) spot analysis and 2D X-Ray maps indicate the filaments rarely have detectable nitrogen levels and exhibit elemental compositions consistent with that interpretation that of the meteorite rock matrix. Many of the meteorite filaments are exceptionally well-preserved and show evidence of cells, cell-wall constrictions and specialized cells and processes for reproduction, nitrogen fixation, attachment and motility. Morphological and morphometric analyses permit many of the filaments to be associated with morphotypes of known genera and species of known filamentous trichomic prokaryotes (cyanobacteria and sulfur bacteria). The presence in carbonaceous meteorites of diagenetic breakdown products of chlorophyll (pristane and phytane) along with indigenous and extraterrestrial chiral protein amino acids, nucleobases and other life-critical biomolecules provides strong support to the hypothesis that these filaments represent the remains of cyanobacteria and other microorganisms that grew on the meteorite parent body. The absence of other life-critical biomolecules in the meteorites and the lack of detectable levels of nitrogen indicate the filaments died long ago and can not possibly represent modern microbial contaminants that entered the stones after they arrived on Earth. This paper presents new evidence for microfossils, biomolecules and biominerals in carbonaceous meteorites and considers the implications to some of the major hypotheses for the Origin of Life.

Fabricating eco-friendly nanocomposites of SiC with morphologically-different nano-carbonaceous phases 

DEFF Research Database (Denmark)

Candelario, Victor M.; Moreno, Rodrigo; Guiberteau, Fernando

2018-01-01

A route based on aqueous colloidal processing followed by liquid-phase assisted spark-plasma-sintering (SPS) is described for fabricating eco-friendly nanocomposites of SiC with nano-carbonaceous phases (nanotubes, nanoplatelets, or nanoparticles). To this end, the conditions optimizing the aqueo...

Pyrolitic carbon from biomass precursors as anode materials for lithium batteries

Energy Technology Data Exchange (ETDEWEB)

Stephan, A. Manuel [School of Chemical Engineering and Technology, Chonbuk National University, Chonju 561-756 (Korea, Republic of); Central Electrochemical Research Institute, Karaikudi 630006 (India); Kumar, T. Prem [Central Electrochemical Research Institute, Karaikudi 630006 (India); Ramesh, R. [Central Electrochemical Research Institute, Karaikudi 630006 (India); Thomas, Sabu [School of Chemical Sciences, Mahatma Gandhi University, Kottayam 686560 (India); Jeong, Soo Kyung [School of Chemical Engineering and Technology, Chonbuk National University, Chonju 561-756 (Korea, Republic of); Nahm, Kee Suk [School of Chemical Engineering and Technology, Chonbuk National University, Chonju 561-756 (Korea, Republic of)]. E-mail: nahmks@chonbuk.ac.kr

2006-08-25

Disordered carbonaceous materials were synthesized by the pyrolysis of banana fibers treated with pore-forming substances such as ZnCl{sub 2} and KOH. X-ray diffraction studies indicated a carbon structure with a large number of disorganized single layer carbon sheets. Addition of porogenic agent led to remarkable changes in the structure and morphology of the carbonaceous products. The product obtained with ZnCl{sub 2} treatment gave first-cycle lithium insertion and de-insertion capacities of 3325 and 400 mAh g{sup -1}, respectively. Lower capacities only could be realized in the subsequent cycles, although the coulombic efficiency increased upon cycling, which in the 10th cycle was 95%.

Factors influencing the outdoor concentration of carbonaceous aerosols at urban schools in Brisbane, Australia: Implications for children's exposure

International Nuclear Information System (INIS)

Crilley, L.R.; Ayoko, G.A.; Mazaheri, M.; Morawska, L.

2016-01-01

This comprehensive study aimed to determine the sources and driving factors of organic carbon (OC) and elemental carbon (EC) concentrations in ambient PM 2.5 in urban schools. Sampling was conducted outdoors at 25 schools in the Brisbane Metropolitan Area, Australia. Concentrations of primary and secondary OC were quantified using the EC tracer method, with secondary OC accounting for an average of 60%. Principal component analysis distinguished the contributing sources above the background and identified groups of schools with differing levels of primary and secondary carbonaceous aerosols. Overall, the results showed that vehicle emissions, local weather conditions and secondary organic aerosols (SOA) were the key factors influencing concentrations of carbonaceous component of PM 2.5 at these schools. These results provide insights into children's exposure to vehicle emissions and SOA at such urban schools. - Highlights: • We aimed to find the contributing sources to children's exposure at school. • Measured outdoor organic carbon and elemental carbon at 25 urban schools. • Schools varied in exposure to primary and secondary sources. • Secondary organic carbon the largest component of carbonaceous aerosols. • Vehicle emission levels at schools are primarily dependent on local traffic counts. - Key factors influencing concentrations of carbonaceous component of PM 2.5 at urban schools were found to be vehicle emissions, secondary organic aerosols and local weather conditions.

Dome C UltraCarbonaceous Antarctic MicroMeteorites Infrared and Raman fingerprints

OpenAIRE

Dartois, E.; Engrand, C.; Duprat, J.; Godard, M.; Charon, E.; Delauche, L.; Sandt, C.; Borondics, F.

2017-01-01

UltraCarbonaceous Antarctic MicroMeteorites (UCAMMs) represent a small fraction of interplanetary dust particles reaching the Earth's surface and contain large amounts of an organic component not found elsewhere. They are most probably sampling a contribution from the outer regions of the solar system to the local interplanetary dust particle flux. We characterize UCAMMs composition focusing on the organic matter, and compare the results to the insoluble organic matter (IOM) from primitive me...

Infrared Spectroscopy of Carbonaceous-chondrite Inclusions in the Kapoeta Meteorite: Discovery of Nanodiamonds with New Spectral Features and Astrophysical Implications

Science.gov (United States)

Abdu, Yassir A.; Hawthorne, Frank C.; Varela, Maria E.

2018-03-01

We report the finding of nanodiamonds, coexisting with amorphous carbon, in carbonaceous-chondrite (CC) material from the Kapoeta achondritic meteorite by Fourier-transform infrared (FTIR) spectroscopy and micro-Raman spectroscopy. In the C–H stretching region (3100–2600 cm‑1), the FTIR spectrum of the Kapoeta CC material (KBr pellet) shows bands attributable to aliphatic CH2 and CH3 groups, and is very similar to IR spectra of organic matter in carbonaceous chondrites and the diffuse interstellar medium. Nanodiamonds, as evidenced by micro-Raman spectroscopy, were found in a dark region (∼400 μm in size) in the KBr pellet. Micro-FTIR spectra collected from this region are dramatically different from the KBr-pellet spectrum, and their C–H stretching region is dominated by a strong and broad absorption band centered at ∼2886 cm‑1 (3.47 μm), very similar to that observed in IR absorption spectra of hydrocarbon dust in dense interstellar clouds. Micro-FTIR spectroscopy also indicates the presence of an aldehyde and a nitrile, and both of the molecules are ubiquitous in dense interstellar clouds. In addition, IR peaks in the 1500–800 cm‑1 region are also observed, which may be attributed to different levels of nitrogen aggregation in diamonds. This is the first evidence for the presence of the 3.47 μm interstellar IR band in meteorites. Our results further support the assignment of this band to tertiary CH groups on the surfaces of nanodiamonds. The presence of the above interstellar bands and the absence of shock features in the Kapoeta nanodiamonds, as indicated by Raman spectroscopy, suggest formation by a nebular-condensation process similar to chemical-vapor deposition.

The Effect of Aqueous Alteration in Antarctic Carbonaceous Chondrites from Comparative ICP-MS Bulk Chemistry

Science.gov (United States)

Alonso-Azcarate, J.; Trigo-Rodriguez, J. M.; Moyano-Cambero, C. E.; Zolensky, M.

2014-01-01

Terrestrial ages of Antarctic carbonaceous chondrites (CC) indicate that these meteorites have been preserved in or on ice for, at least, tens of thousands of years. Due to the porous structure of these chondrites formed by the aggregation of silicate-rich chondrules, refractory inclusions, metal grains, and fine-grained matrix materials, the effect of pervasive terrestrial water is relevant. Our community defends that pristine CC matrices are representing samples of scarcely processed protoplanetary disk materials as they contain stellar grains, but they might also trace parent body processes. It is important to study the effects of terrestrial aqueous alteration in promoting bulk chemistry changes, and creating distinctive alteration minerals. Particularly because it is thought that aqueous alteration has particularly played a key role in some CC groups in modifying primordial bulk chemistry, and homogenizing the isotopic content of fine-grained matrix materials. Fortunately, the mineralogy produced by parent-body and terrestrial aqueous alteration processes is distinctive. With the goal to learn more about terrestrial alteration in Antarctica we are obtaining reflectance spectra of CCs, but also performing ICP-MS bulk chemistry of the different CC groups. A direct comparison with the mean bulk elemental composition of recovered falls might inform us on the effects of terrestrial alteration in finds. With such a goal, in the current work we have analyzed some members representative of CO and CM chondrite groups.

Production of activated charcoal beads or green moldnings useful in stationary or fluidized bed uses rotary stirrer(s) for mixing carbonaceous powder with binder

DEFF Research Database (Denmark)

2000-01-01

In the production of activated charcoal beads or green moldings by mixing carbonaceous powder with a binder, mixing is carried out in a stirred vessel with rotary stirrer(s).......In the production of activated charcoal beads or green moldings by mixing carbonaceous powder with a binder, mixing is carried out in a stirred vessel with rotary stirrer(s)....

Glass-Graphite Composite Materials

International Nuclear Information System (INIS)

Mayzan, M.Z.H.; Lloyd, J.W.; Heath, P.G.; Stennett, M.C.; Hyatt, N.C.; Hand, R.J.

2016-01-01

A summary is presented of investigations into the potential of producing glass-composite materials for the immobilisation of graphite or other carbonaceous materials arising from nuclear power generation. The methods are primarily based on the production of base glasses which are subsequently sintered with powdered graphite or simulant TRISO particles. Consideration is also given to the direct preparation of glass-graphite composite materials using microwave technology. Production of dense composite wasteforms with TRISO particles was more successful than with powdered graphite, as wasteforms containing larger amounts of graphite were resistant to densification and the glasses tried did not penetrate the pores under the pressureless conditions used. Based on the results obtained it is concluded that the production of dense glassgraphite composite wasteforms will require the application of pressure. (author)

Sources of increase in lowermost stratospheric sulphurous and carbonaceous aerosol background concentrations during 1999–2008 derived from CARIBIC flights

Directory of Open Access Journals (Sweden)

Johan Friberg

2014-03-01

Full Text Available This study focuses on sulphurous and carbonaceous aerosol, the major constituents of particulate matter in the lowermost stratosphere (LMS, based on in situ measurements from 1999 to 2008. Aerosol particles in the size range of 0.08–2 µm were collected monthly during intercontinental flights with the CARIBIC passenger aircraft, presenting the first long-term study on carbonaceous aerosol in the LMS. Elemental concentrations were derived via subsequent laboratory-based ion beam analysis. The stoichiometry indicates that the sulphurous fraction is sulphate, while an O/C ratio of 0.2 indicates that the carbonaceous aerosol is organic. The concentration of the carbonaceous component corresponded on average to approximately 25% of that of the sulphurous, and could not be explained by forest fires or biomass burning, since the average mass ratio of Fe to K was 16 times higher than typical ratios in effluents from biomass burning. The data reveal increasing concentrations of particulate sulphur and carbon with a doubling of particulate sulphur from 1999 to 2008 in the northern hemisphere LMS. Periods of elevated concentrations of particulate sulphur in the LMS are linked to downward transport of aerosol from higher altitudes, using ozone as a tracer for stratospheric air. Tropical volcanic eruptions penetrating the tropical tropopause are identified as the likely cause of the particulate sulphur and carbon increase in the LMS, where entrainment of lower tropospheric air into volcanic jets and plumes could be the cause of the carbon increase.

Extraterrestrial Amino Acids Identified in Metal-Rich CH and CB Carbonaceous Chondrites from Antarctica

Science.gov (United States)

Burton, Aaron S.; Elsila, Jamie E.; Hein, Jason E.; Glavin, Daniel P.; Dworkin, Jason P.

2013-01-01

Carbonaceous chondrites contain numerous indigenous organic compounds and could have been an important source of prebiotic compounds required for the origin of life on Earth or elsewhere. Extraterrestrial amino acids have been reported in five of the eight groups of carbonaceous chondrites and are most abundant in CI, CM, and CR chondritesbut are also present in the more thermally altered CV and CO chondrites. We report the abundance, distribution, and enantiomeric and isotopic compositions of simple primary amino acids in six metal-rich CH and CB carbonaceous chondrites that have not previously been investigated for amino acids: Allan Hills (ALH) 85085 (CH3), Pecora Escarpment(PCA) 91467 (CH3), Patuxent Range (PAT) 91546 (CH3), MacAlpine Hills (MAC) 02675(CBb), Miller Range (MIL) 05082 (CB), and Miller Range (MIL) 07411 (CB). Amino acid abundances and carbon isotopic values were obtained by using both liquid chromatography time-of-flight mass spectrometry and fluorescence, and gas chromatography isotope ratiomass spectrometry. The (delta D, delta C-13, delta N-15) ratios of multiple amino acids fall outside of the terrestrial range and support their extraterrestrial origin. Extracts of CH chondrites were found to be particularly rich in amino acids (1316 parts per million, ppm) while CB chondrite extracts had much lower abundances (0.22 ppm). The amino acid distributions of the CH and CB chondrites were distinct from the distributions observed in type 2 and 3 CM and CR chondrites and contained elevated levels of beta-, gamma-, and delta-amino acids compared to the corresponding alpha-amino acids, providing evidence that multiple amino acid formation mechanisms were important in CH and CB chondrites.

Carbonaceous content of atmospheric aerosols in Lisbon urban atmosphere

Science.gov (United States)

Mirante, Fátima; Oliveira, C.; Martins, N.; Pio, C.; Caseiro, A.; Cerqueira, M.; Alves, C.; Oliveira, C.; Oliveira, J.; Camões, F.; Matos, M.; Silva, H.

2010-05-01

Lisbon is the capital city of Portugal with about 565,000 residents and a population density of 6,600 inhabitants per square kilometre. The town is surrounded by satellite cities, forming together a region known as "Lisbon Metropolitan Area" with about 3 million inhabitants. It is estimated that more than one million citizens come into the Lisbon area every day from the outskirts, leading to elevated traffic densities and intense traffic jams. Airborne particulate matter limit values are frequently exceeded, with important consequences on air pollution levels and obvious negative impacts on human health. Atmospheric aerosols are known to have in their structure significant amounts of carbonaceous material. The knowledge of the aerosols carbon content, particularly on their several carbon forms (as TC, EC and OC, meaning respectively Total, Elemental and Organic carbon) is often required to provide information for source attribution. In order to assess the vehicles PM input, two sampling campaigns (summer and winter periods) were carried out in 2008 in Lisbon in two contrasting sites, a roadside and an urban background site. Particulate matter was collected in two fractions on quartz fibre filters using Hi-Vol samplers (coarse fraction, 2.5µmwork was performed under Project PAHLIS (Polycyclic Aromatic Hydrocarbons Contamination in Lisbon Urban Atmosphere - PTDC/AMB/65699/2006) financed by "Fundação para a Ciência e a Tecnologia" - FCT. Fátima Mirante acknowledges FCT her PhD grant (SFRH/BD/45473/2008).

Measurements of non-volatile aerosols with a VTDMA and their correlations with carbonaceous aerosols in Guangzhou, China

Science.gov (United States)

Cheung, Heidi H. Y.; Tan, Haobo; Xu, Hanbing; Li, Fei; Wu, Cheng; Yu, Jian Z.; Chan, Chak K.

2016-07-01

Simultaneous measurements of aerosol volatility and carbonaceous matters were conducted at a suburban site in Guangzhou, China, in February and March 2014 using a volatility tandem differential mobility analyzer (VTDMA) and an organic carbon/elemental carbon (OC / EC) analyzer. Low volatility (LV) particles, with a volatility shrink factor (VSF) at 300 °C exceeding 0.9, contributed 5 % of number concentrations of the 40 nm particles and 11-15 % of the 80-300 nm particles. They were composed of non-volatile material externally mixed with volatile material, and therefore did not evaporate significantly at 300 °C. Non-volatile material mixed internally with the volatile material was referred to as medium volatility (MV, 0.4 transported at low altitudes (below 1500 m) for over 40 h before arrival. Further comparison with the diurnal variations in the mass fractions of EC and the non-volatile OC in PM2.5 suggests that the non-volatile residuals may be related to both EC and non-volatile OC in the afternoon, during which the concentration of aged organics increased. A closure analysis of the total mass of LV and MV residuals and the mass of EC or the sum of EC and non-volatile OC was conducted. It suggests that non-volatile OC, in addition to EC, was one of the components of the non-volatile residuals measured by the VTDMA in this study.

Amino Acid Chemistry as a Link Between Small Solar System Bodies and Carbonaceous Chondrites

Science.gov (United States)

Glavin, Daniel P.; Ehrenfreund, Pascale; Botta, Oliver; Cooper, George; Bada, Jeffrey L.

2000-01-01

Establishing chemical links between meteorites and small solar system bodies, such as comets and asteroids, provides a tool for investigating the processes that occurred during the formation of the solar system. Carbonaceous meteorites are of particular interest, since they may have seeded the early Earth with a variety of prebiotic organic compounds including amino acids, purines and pyrimidines, which are thought to be necessary for the origin of life. Here we report the results of high-performance liquid chromatography (HPLC) based amino acid analyses of the acid-hydrolyzed hot water extracts from pristine interior pieces of the CI carbonaceous chondrites Orgueil and Ivuna and the CM meteorites Murchison and Murray. We found that the CI meteorites Orgueil and Ivuna contained high abundances of beta-alanine and glycine, while only traces of other amino acids like alanine, alpha-amino-n-butryic acid (ABA) and alpha-aminoisobutyric acid (AIB) were detected in these meteorites. Carbon isotopic measurements of beta-alanine and glycine in Orgueil by gas chromatography combustion-isotope ratio mass spectrometry clearly indicate an extraterrestrial origin of these amino acids. The amino acid composition of Orgueil and Ivuna was strikingly different from the CM chondrites Murchison and Murray. The most notable difference was the high relative abundance of B-alanine in Orgueil and Ivuna compared to Murchison and Murray. Furthermore, AIB, which is one of the most abundant amino acids found in Murchison and Murray, was present in only trace amounts in Orgueil and Ivuna. Our amino acid data strongly suggest that the CI meteorites Orgueil and Ivuna came from a different type of parent body than the CM meteorites Murchison and Murray, possibly from an extinct comet. It is generally thought that carbonaceous meteorites are fragments of larger asteroidal bodies delivered via near Earth objects (NEO). Orbital and dynamic studies suggest that both fragments of main belt asteroids

Characterization of carbonaceous matter in xenolithic clasts from the Sharps (H3.4) meteorite: Constraints on the origin and thermal processing

Energy Technology Data Exchange (ETDEWEB)

Kebukawa, Yoko [Yokohama National Univ. (Japan); Zolensky, Michael E. [NASA Johnson Space Center, Houston, TX (United States); Chan, Queenie H. S. [NASA Johnson Space Center, Houston, TX (United States); Nagao, Keisuke [Univ. of Tokyo (Japan); Kilcoyne, A. L. David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Bodnar, Robert J. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Farley, Charles [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Rahman, Zia [NASA Johnson Space Center, Houston, TX (United States); Le, Loan [NASA Johnson Space Center, Houston, TX (United States); Cody, George D. [Carnegie Inst. of Washington, Washington, DC (United States)

2016-09-25

almost identical with some material reported in carbonaceous chondrites, i.e., heavily enriched in the Q-gas component as well as HL-gas from presolar diamonds and Ne-E(H) from presolar SiC. These results indicate that the C-rich aggregates in the Sharps clasts formed under relatively high temperature conditions, up to 800 °C, and were subsequently mixed with lower temperature matrix, probably in a different parent body, before they were incorporated into the final Sharps lithology by collision.

Aqueous processing of organic compounds in carbonaceous asteroids

Science.gov (United States)

Trigo-Rodríguez, Josep Maria; Rimola, Albert; Martins, Zita

2015-04-01

There is growing evidence pointing towards a prebiotic synthesis of complex organic species in water-rich undifferentiated bodies. For instance, clays have been found to be associated with complex organic compounds (Pearson et al. 2002; Garvie & Buseck 2007; Arteaga et al. 2010), whereas theoretical calculations have studied the interaction between the organic species and surface minerals (Rimola et al., 2013) as well as surface-induced reactions (Rimola at al. 2007). Now, we are using more detailed analytical techniques to study the possible processing of organic molecules associated with the mild aqueous alteration in CR, CM and CI chondrites. To learn more about these processes we are studying carbonaceous chondrites at Ultra High-Resolution Transmission Electron Microscopy (UHR-TEM). We are particularly interested in the relationship between organics and clay minerals in carbonaceous chondrites (CCs) matrixes (Trigo-Rodríguez et al. 2014, 2015).We want to address two goals: i) identifying the chemical steps in which the organic molecules could have increased their complexity (i.e., surface interaction and catalysis); and ii) studying if the organic matter present in CCs experienced significant processing concomitant to the formation of clays and other minerals at the time in which these planetary bodies experienced aqueous alteration. Here, these two points are preliminarily explored combing experimental results with theoretical calculations based on accurate quantum mechanical methods. References Arteaga O, Canillas A, Crusats J, El-Hachemi Z, Jellison GE, Llorca J, Ribó JM (2010) Chiral biases in solids by effect of shear gradients: a speculation on the deterministic origin of biological homochirality. Orig Life Evol Biosph 40:27-40. Garvie LAJ, Buseck PR (2007) Prebiotic carbon in clays from Orgueil and Ivuna (CI) and Tagish lake (C2 ungrouped) meteorites. Meteorit Planet Sci 42:2111-2117. Pearson VK, Sephton MA, Kearsley AT, Bland AP, Franchi IA, Gilmour

Carbonaceous Survivability on Impact

Science.gov (United States)

Bunch, T. E.; Becker, Luann; Morrison, David (Technical Monitor)

1994-01-01

In order to gain knowledge about the potential contributions of comets and cosmic dust to the origin of life on Earth, we need to explore the survivability of their potential organic compounds on impact and the formation of secondary products that may have arisen from the chaotic events sustained by the carriers as they fell to Earth. We have performed a series of hypervelocity impact experiments using carbon-bearing impactors (diamond, graphite, kerogens, PAH crystals, and Murchison and Nogoya meteorites) into Al plate targets at velocities - 6 km/s. Estimated peak shock pressures probably did not exceed 120 GPa and peak shock temperatures were probably less than 4000 K for times of nano- to microsecs. Nominal crater dia. are less than one mm. The most significant results of these experiments are the preservation of the higher mass PAHs (e. g., pyrene relative to napthalene) and the formation of additional alkylated PAHs. We have also examined the residues of polystyrene projectiles impacted by a microparticle accelerator into targets at velocities up to 15 km/s. This talk will discuss the results of these experiments and their implications with respect to the survival of carbonaceous deliverables to early Earth. The prospects of survivability of organic molecules on "intact" capture of cosmic dust in space via soft: and hard cosmic dust collectors will also be discussed.

Fermentation, gasification and pyrolysis of carbonaceous residues towards usage in fuel cells

International Nuclear Information System (INIS)

Sequeira, C.A.C.; Brito, P.S.D.; Mota, A.F.; Carvalho, J.L.; Rodrigues, L.F.F.T.T.G.; Santos, D.M.F.; Barrio, D.B.; Justo, D.M.

2007-01-01

In this paper, the technologies of fermentation, gasification and pyrolysis of carbonaceous residues for the production of biohydrogen and other gaseous, liquid or solid fuels, are analysed. The energetic, economic and environmental advantages of linking these energy areas with the fuel cell engines are stressed. In addition, the current status of fuel cell technologies, namely their historic trends, basic electrode mechanisms, cell types, market drivers and leading issues, are reviewed

A European Aerosol Phenomenology -4: Harmonized Concentrations of Carbonaceous Aerosol at 10 Regional Background Sites Across Europe.

Czech Academy of Sciences Publication Activity Database

Cavalli, F.; Areskoug, H.; Ceburnis, D.; Čech, J.; Genberg, J.; Harrison, R. M.; Jaffrezo, J.L.; Kiss, G.; Laj, P.; Mihalopoulos, N.; Perez, N.; Quincey, P.; Schwarz, Jaroslav; Sellegri, K.; Spindler, G.; Swietlicki, E.; Theodosi, C.; Yttri, K.E.; Aas, W.; Putaud, J.P.

2016-01-01

Roč. 144, NOV 2016 (2016), s. 133-145 ISSN 1352-2310 Institutional support: RVO:67985858 Keywords : aerosol * carbonaceous * PM Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.629, year: 2016

R Raman Spectroscopy and Petrology of Antarctic CR Chondrites: Comparison with Other Carbonaceous Chondrites

Science.gov (United States)

Komatsu, M.; Fagan, T. J.; Yamaguchi, A.; Mikouchi, T.; Zolensky, M. E.; Yasutake, M.

2015-01-01

In Renazzo-like carbonaceous (CR) chondrites, abundant original Fe,Ni-metal is preserved in chrondules, but the matrix is characterized by fine-grained magnetite with phyllosilicate. This combination of reduced Fe in chrodrules with oxidized Fe and phyllosilicate in the matrix has been attributed to aqueous alteration of matrix at relatively low temperatures.

Environment Conscious Ceramics (Ecoceramics): An Eco-Friendly Route to Advanced Ceramic Materials

Science.gov (United States)

Singh, M.

2001-01-01

Environment conscious ceramics (Ecoceramics) are a new class of materials, which can be produced with renewable natural resources (wood) or wood wastes (wood sawdust). This technology provides an eco-friendly route to advanced ceramic materials. Ecoceramics have tailorable properties and behave like ceramic materials manufactured by conventional approaches. Silicon carbide-based ecoceramics have been fabricated by reactive infiltration of carbonaceous preforms by molten silicon or silicon-refractory metal alloys. The fabrication approach, microstructure, and mechanical properties of SiC-based ecoceramics are presented.

Implementing a new EPR lineshape parameter for organic radicals in carbonaceous matter.

Science.gov (United States)

Bourbin, Mathilde; Du, Yann Le; Binet, Laurent; Gourier, Didier

2013-07-17

Electron Paramagnetic Resonance (EPR) is a non-destructive, non-invasive technique useful for the characterization of organic moieties in primitive carbonaceous matter related to the origin of life. The classical EPR parameters are the peak-to-peak amplitude, the linewidth and the g factor; however, such parameters turn out not to suffice to fully determine a single EPR line. In this paper, we give the definition and practical implementation of a new EPR parameter based on the signal shape that we call the R10 factor. This parameter was originally defined in the case of a single symmetric EPR line and used as a new datation method for organic matter in the field of exobiology. Combined to classical EPR parameters, the proposed shape parameter provides a full description of an EPR spectrum and opens the way to novel applications like datation. Such a parameter is a powerful tool for future EPR studies, not only of carbonaceous matter, but also of any substance which spectrum exhibits a single symmetric line. The paper is a literate program-written using Noweb within the Org-mode as provided by the Emacs editor- and it also describes the full data analysis pipeline that computes the R10 on a real EPR spectrum.

Agglomeration Determines Effects of Carbonaceous Nanomaterials on Soybean Nodulation, Dinitrogen Fixation Potential, and Growth in Soil

Science.gov (United States)

The potential effects of carbonaceous nanomaterials (CNMs) on agricultural plants are of concern. However, little research has been performed using plants cultivated to maturity in soils contaminated with various CNMs at different concentrations. Here, we grew soybean for 39 days...

Photoelectric work function studies of carbonaceous films containing Ni nanocrystals

International Nuclear Information System (INIS)

Czerwosz, E.; Dluzewski, P.; Kutner, T.; Stacewicz, T.

2003-01-01

In this paper we present the results of photoelectric work function measurements for carbonaceous films containing Ni nanocrystals. The investigated films were obtained by thermal vacuum deposition method. The structure of films was studied by electron diffraction, transmission microscopy and Raman spectroscopy. Film structure depends on Ni contents in the film volume. Work function determined from photoelectric measurements for all investigated films are similar and lie in the range of 2.65-2.93 eV. The decrease of work function value with the cleaning of the film's surface with UV pulsed laser beam was observed

Enantiomer excesses of rare and common sugar derivatives in carbonaceous meteorites

OpenAIRE

Cooper, George; Rios, Andro C.

2016-01-01

The majority of biological sugars and their derivatives contain higher abundances of the “d” mirror-image forms relative to the “l” forms. For example, nucleic acids are composed of only d sugars. Carbonaceous meteorites can potentially assist in understanding the long-sought origin of such phenomena; They preserve a record of the earliest (∼4.5 Gy) chemical processes in the Solar System. To date, there have been no systematic studies of d/l (i.e., enantiomer) ratios of meteoritic sugar deriv...

Characterization of carbonaceous aerosol emissions from selected combustion sources

International Nuclear Information System (INIS)

Martinez, J.P.G.; Espino, M.P.M.; Pabroa, P.C.B.; Bautista, A.T. VII

2015-01-01

Carbonaceous Particulates are carbon-containing solid or liquid matter which form a significant portion of the fine particulate mass (PM2.5) and these have known profound adverse effects on health, climate and visibility. This study aims to characterize carbonaceous aerosol emissions from different combustion sources to establish fingerprints for these for use in the refinement of improvement of the resolution of sources apportionment studies being done by the Philippine Nuclear Research Institute (PNRI), i.e. to resolve vehicular emission sources. Fine air particulate sample were collected in pre-baked Quartz filters using an improvised collection set-up with a Gent sampler. Concentrations of organic and elemental carbon (OC and EC, respectively) in PM2.5 were measured for the different combustion sources—vehicular emissions, tire pyrolysis, and biomass burning, using a thermal-optical method of analysis following the IMPROVE_A protocol. Measured OC ad EC concentrations are shown as percentages with respect to the total carbon (TC) and are illustrated in a 100% stacked chart. Predominance of the EC2 fraction is exhibited in both the diesel fuelled vehicle and tire pyrolysis emissions with EC2/OC2 ratio distinguishing one from the other, EC2/OC2 is 1.63 and 8.41, respectively. Predominance of either OC2 or OC3 fraction is shown in the unleaded gasoline and LPG Fuelled vehicles and in biomass burning with the OC2/OC3 ratio distinguishing one from the others. OC2/OC3 ratios are 1.33 for unleaded gasoline fuelled vehicle, 1.89 for LPG-fuelled vehicle, 0.55 for biomass burning (leaves) and 0.82 biomass burning (wood). The study has shown probable use of the EC2/OC2 and OC2/OC3 ratios to distinguish fingerprints for combustion sources covered in this study. (author)

Influence of Bulk Carbonaceous Matter on Pluto's Structure and Evolution

Science.gov (United States)

McKinnon, W. B.; Stern, S. A.; Weaver, H. A., Jr.; Spencer, J. R.; Moore, J. M.; Young, L. A.; Olkin, C.

2017-12-01

The rock/ice mass ratio of the Pluto system is about 2/1 (McKinnon et al., Icarus 287, 2017) [1], though this neglects the potential role of bulk carbonaceous matter ("CHON"), an important cometary component and one likely important in the ancestral Kuiper belt. The wealth of measurements at comet 67P/Churyumov-Gerasimenko (a Jupiter-family comet and thus one formed in the same region of the outer Solar System as Pluto) by Rosetta are particularly instructive. E.g., Davidsson et al. (A&A 592, 2016) [2] propose in their "composition A" that 67P/Ch-G is 25% metal/sulfides, 42% rock/organics, and 32% ice by mass. For their assumed component densities, the overall grain density is 1820 kg/m3. Fulle et al. (MNRAS 462, 2016) [3] posit 5 ± 2 volume % Fe-sulfides of density 4600 kg/m3, 28 ± 5% Mg,Fe-olivines and -pyroxenes of density 3200 kg/m3, 52 ± 12% hydrocarbons of density 1200 kg/m3, and 15 ± 6% ices of 917 kg/m3. This composition yields a primordial grain density (dust + ice) of 1885 ± 240 kg/m3. Both of these cometary density estimates [2,3] are consistent with Pluto-Charon, especially as Pluto's uncompressed (STP) density is close to 1820 kg/m3 and that of the system as a whole is close to 1800 kg/m3 [1]. We consider the potential compositional and structural implications of these proposed 67P/Ch-G compositions when applied to Pluto and Charon. The amount of ice in model A of [2] is a good match to Pluto structural models. Their rock/organics component, however, is taken to be half graphite (2000 kg/m3) by volume. The composition in [3] is more divergent: very ice poor, and on the order of 50% light hydrocarbons by volume. Regardless of the differences between [2] and [3], the possibility of massive internal graphite or carbonaceous layers within Pluto is real. We discuss the possible consequences for Pluto's structure, rock/ice ratio, thermal and chemical evolution, and even interpretation of its gravity field from tectonics. For example, radiogenic heat

Characteristics and major sources of carbonaceous aerosols in PM{sub 2.5} from Sanya, China

Energy Technology Data Exchange (ETDEWEB)

Wang, Jingzhi [Key Lab of Aerosol Chemistry & Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); State Key Lab of Loess and Quaternary Geology (SKLLQG), Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); Ho, Steven Sai Hang [Key Lab of Aerosol Chemistry & Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); Division of Atmospheric Sciences, Desert Research Institute, Reno, NV (United States); Cao, Junji, E-mail: cao@loess.llqg.ac.cn [Key Lab of Aerosol Chemistry & Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); State Key Lab of Loess and Quaternary Geology (SKLLQG), Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); Institute of Global Environmental Change, Xi' an Jiaotong University, Xi' an (China); Huang, Rujin [Key Lab of Aerosol Chemistry & Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); State Key Lab of Loess and Quaternary Geology (SKLLQG), Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), 5232 Villigen (Switzerland); Zhou, Jiamao [Key Lab of Aerosol Chemistry & Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); State Key Lab of Loess and Quaternary Geology (SKLLQG), Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); Zhao, Youzhi [College of Science and Technology, Qiongzhou University, Sanya (China); Xu, Hongmei [Department of Environmntal Science and Engineering, Xi' an Jiaotong University, Xi' an (China); Liu, Suixin; Wang, Gehui [Key Lab of Aerosol Chemistry & Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); State Key Lab of Loess and Quaternary Geology (SKLLQG), Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); and others

2015-10-15

PM{sub 2.5} samples were collected in Sanya, China in summer and winter in 2012/2013. Organic carbon (OC), elemental carbon (EC), and non-polar organic compounds including n-alkanes (n-C{sub 14}-n-C{sub 40}) and polycyclic aromatic hydrocarbons (PAHs) were quantified. The concentrations of these carbonaceous matters were generally higher in winter than summer. The estimated secondary organic carbon (OC{sub sec}) accounted for 38% and 54% of the total organic carbon (TOC) in winter and summer, respectively. The higher value of OC{sub sec} in addition to the presences of photochemically-produced PAHs in summer supports that photochemical conversions of organics are much active at the higher air temperatures and with stronger intense solar radiation. Carbon preference index (CPI) and percent contribution of wax n-alkanes suggest that anthropogenic sources were more dominant than derivation from terrestrial plants in Sanya. Diagnostic ratios of atmospheric PAHs further indicate that there was a wide mix of pollution sources in winter while fossil fuel combustion was the most dominant in summer. Positive Matrix Factorization (PMF) analysis with 18 PAHs in the winter samples found that motor vehicle emissions and biomass burning were the two main pollution sources, contributing 37.5% and 24.6% of the total quantified PAHs, respectively. - Highlights: • The first comprehensive study to investigate carbonaceous PM{sub 2.5} in Sanya, China • Higher carbonaceous levels in winter while more SOC formation in summer • Anthropogenic emission is the dominant sources of n-alkanes • Vehicle emission and biomass burning contributed ≥60% of the total PAHs in winter • The result supports better air quality in Sanya than most megacities in China.

Carbonaceous aerosols and pollutants over Delhi urban environment: Temporal evolution, source apportionment and radiative forcing

Energy Technology Data Exchange (ETDEWEB)

Bisht, D.S. [Indian Institute of Tropical Meteorology, New Delhi (India); Dumka, U.C., E-mail: dumka@aries.res.in [Aryabhatta Research Institute of Observational Sciences, Nainital (India); Kaskaoutis, D.G. [School of Natural Sciences, Shiv Nadar University, Tehsil Dadri (India); Pipal, A.S. [Department of Chemistry, Savitribai Phule Pune University, Pune (India); Srivastava, A.K. [Indian Institute of Tropical Meteorology, New Delhi (India); Soni, V.K.; Attri, S.D.; Sateesh, M. [India Meteorology Department, Lodhi Road, New Delhi (India); Tiwari, S. [Indian Institute of Tropical Meteorology, New Delhi (India)

2015-07-15

Particulate matter (PM{sub 2.5}) samples were collected over Delhi, India during January to December 2012 and analysed for carbonaceous aerosols and inorganic ions (SO{sub 4}{sup 2−} and NO{sub 3}{sup −}) in order to examine variations in atmospheric chemistry, combustion sources and influence of long-range transport. The PM{sub 2.5} samples are measured (offline) via medium volume air samplers and analysed gravimetrically for carbonaceous (organic carbon, OC; elemental carbon, EC) aerosols and inorganic ions (SO{sub 4}{sup 2−} and NO{sub 3}{sup −}). Furthermore, continuous (online) measurements of PM{sub 2.5} (via Beta-attenuation analyser), black carbon (BC) mass concentration (via Magee scientific Aethalometer) and carbon monoxide (via CO-analyser) are carried out. PM{sub 2.5} (online) range from 18.2 to 500.6 μg m{sup −3} (annual mean of 124.6 ± 87.9 μg m{sup −3}) exhibiting higher night-time (129.4 μg m{sup −3}) than daytime (103.8 μg m{sup −3}) concentrations. The online concentrations are 38% and 28% lower than the offline during night and day, respectively. In general, larger night-time concentrations are found for the BC, OC, NO{sub 3}{sup −}and SO{sub 4}{sup 2−}, which are seasonally dependent with larger differences during late post-monsoon and winter. The high correlation (R{sup 2} = 0.74) between OC and EC along with the OC/EC of 7.09 (day time) and 4.55 (night-time), suggest significant influence of biomass-burning emissions (burning of wood and agricultural waste) as well as secondary organic aerosol formation during daytime. Concentrated weighted trajectory (CWT) analysis reveals that the potential sources for the carbonaceous aerosols and pollutants are local emissions within the urban environment and transported smoke from agricultural burning in northwest India during post-monsoon. BC radiative forcing estimates result in very high atmospheric heating rates (~ 1.8–2.0 K day{sup −1}) due to agricultural burning effects

Carbonaceous aerosols and pollutants over Delhi urban environment: Temporal evolution, source apportionment and radiative forcing

International Nuclear Information System (INIS)

Bisht, D.S.; Dumka, U.C.; Kaskaoutis, D.G.; Pipal, A.S.; Srivastava, A.K.; Soni, V.K.; Attri, S.D.; Sateesh, M.; Tiwari, S.

2015-01-01

Particulate matter (PM 2.5 ) samples were collected over Delhi, India during January to December 2012 and analysed for carbonaceous aerosols and inorganic ions (SO 4 2− and NO 3 − ) in order to examine variations in atmospheric chemistry, combustion sources and influence of long-range transport. The PM 2.5 samples are measured (offline) via medium volume air samplers and analysed gravimetrically for carbonaceous (organic carbon, OC; elemental carbon, EC) aerosols and inorganic ions (SO 4 2− and NO 3 − ). Furthermore, continuous (online) measurements of PM 2.5 (via Beta-attenuation analyser), black carbon (BC) mass concentration (via Magee scientific Aethalometer) and carbon monoxide (via CO-analyser) are carried out. PM 2.5 (online) range from 18.2 to 500.6 μg m −3 (annual mean of 124.6 ± 87.9 μg m −3 ) exhibiting higher night-time (129.4 μg m −3 ) than daytime (103.8 μg m −3 ) concentrations. The online concentrations are 38% and 28% lower than the offline during night and day, respectively. In general, larger night-time concentrations are found for the BC, OC, NO 3 − and SO 4 2− , which are seasonally dependent with larger differences during late post-monsoon and winter. The high correlation (R 2 = 0.74) between OC and EC along with the OC/EC of 7.09 (day time) and 4.55 (night-time), suggest significant influence of biomass-burning emissions (burning of wood and agricultural waste) as well as secondary organic aerosol formation during daytime. Concentrated weighted trajectory (CWT) analysis reveals that the potential sources for the carbonaceous aerosols and pollutants are local emissions within the urban environment and transported smoke from agricultural burning in northwest India during post-monsoon. BC radiative forcing estimates result in very high atmospheric heating rates (~ 1.8–2.0 K day −1 ) due to agricultural burning effects during the 2012 post-monsoon season. - Highlights: • Very high PM 2.5 (> 200 µg m −3 ) levels

Constraining Carbonaceous Aerosol Climate Forcing by Bridging Laboratory, Field and Modeling Studies

Science.gov (United States)

Dubey, M. K.; Aiken, A. C.; Liu, S.; Saleh, R.; Cappa, C. D.; Williams, L. R.; Donahue, N. M.; Gorkowski, K.; Ng, N. L.; Mazzoleni, C.; China, S.; Sharma, N.; Yokelson, R. J.; Allan, J. D.; Liu, D.

2014-12-01

Biomass and fossil fuel combustion emits black (BC) and brown carbon (BrC) aerosols that absorb sunlight to warm climate and organic carbon (OC) aerosols that scatter sunlight to cool climate. The net forcing depends strongly on the composition, mixing state and transformations of these carbonaceous aerosols. Complexities from large variability of fuel types, combustion conditions and aging processes have confounded their treatment in models. We analyse recent laboratory and field measurements to uncover fundamental mechanism that control the chemical, optical and microphysical properties of carbonaceous aerosols that are elaborated below: Wavelength dependence of absorption and the single scattering albedo (ω) of fresh biomass burning aerosols produced from many fuels during FLAME-4 was analysed to determine the factors that control the variability in ω. Results show that ω varies strongly with fire-integrated modified combustion efficiency (MCEFI)—higher MCEFI results in lower ω values and greater spectral dependence of ω (Liu et al GRL 2014). A parameterization of ω as a function of MCEFI for fresh BB aerosols is derived from the laboratory data and is evaluated by field data, including BBOP. Our laboratory studies also demonstrate that BrC production correlates with BC indicating that that they are produced by a common mechanism that is driven by MCEFI (Saleh et al NGeo 2014). We show that BrC absorption is concentrated in the extremely low volatility component that favours long-range transport. We observe substantial absorption enhancement for internally mixed BC from diesel and wood combustion near London during ClearFlo. While the absorption enhancement is due to BC particles coated by co-emitted OC in urban regions, it increases with photochemical age in rural areas and is simulated by core-shell models. We measure BrC absorption that is concentrated in the extremely low volatility components and attribute it to wood burning. Our results support

Dust Infall Onto Phobos and Deimos Can Explain Their Carbonaceous Reflectance Signature, Perhaps Overlying a Mars-Impact-Origin Core: A Hypothesis

Science.gov (United States)

Fries, M.; Cintala, M.; Steele, A.; Welzenbach, L. C.

2017-01-01

Discussions of Phobos' and Deimos' (henceforth P&D) origin(s) include an unresolved conflict: dynamical studies which favor coalescence of the moons from a large impact on Mars [1,2], versus reflectance spectroscopy of the moons showing a carbonaceous composition that is not consistent with martian surface materials [3-5]. One way to reconcile this discrepancy is to consider the combined options of a Mars impact origin for Phobos and Deimos, followed by deposition of carbon-rich materials by interplanetary dust particle (IDP) infall. This is significant because, unlike asteroidal bodies, P&D experience a high IDP flux due to their location in Mars' gravity well. We present some relatively simple, initial calculations which indicate that accreted carbon may be sufficient to produce a surface with sufficient added carbon to account for P&D's reflectance spectra. If this is true, then a major objection to an impact origin for P&D is resolved.

Influence of Electric Fields on Biofouling of Carbonaceous Electrodes.

Science.gov (United States)

Pandit, Soumya; Shanbhag, Sneha; Mauter, Meagan; Oren, Yoram; Herzberg, Moshe

2017-09-05

Biofouling commonly occurs on carbonaceous capacitive deionization electrodes in the process of treating natural waters. Although previous work reported the effect of electric fields on bacterial mortality for a variety of medical and engineered applications, the effect of electrode surface properties and the magnitude and polarity of applied electric fields on biofilm development has not been comprehensively investigated. This paper studies the formation of a Pseudomonas aeruginosa biofilm on a Papyex graphite (PA) and a carbon aerogel (CA) in the presence and the absence of an electric field. The experiments were conducted using a two-electrode flow cell with a voltage window of ±0.9 V. The CA was less susceptible to biofilm formation compared to the PA due to its lower surface roughness, lower hydrophobicity, and significant antimicrobial properties. For both positive and negative applied potentials, we observed an inverse relationship between biofilm formation and the magnitude of the applied potential. The effect is particularly strong for the CA electrodes and may be a result of cumulative effects between material toxicity and the stress experienced by cells at high applied potentials. Under the applied potentials for both electrodes, high production of endogenous reactive oxygen species (ROS) was indicative of bacterial stress. For both electrodes, the elevated specific ROS activity was lowest for the open circuit potential condition, elevated when cathodically and anodically polarized, and highest for the ±0.9 V cases. These high applied potentials are believed to affect the redox potential across the cell membrane and disrupt redox homeostasis, thereby inhibiting bacterial growth.

Inorganic and carbonaceous components in indoor/outdoor particulate matter in two residential houses in Oslo, Norway.

Science.gov (United States)

Lazaridis, Mihalis; Aleksandropoulou, Victoria; Hanssen, Jan Erik; Dye, Christian; Eleftheriadis, Kostantinos; Katsivela, Eleftheria

2008-03-01

A detailed analysis of indoor/outdoor physicochemical aerosol properties has been performed. Aerosol measurements were taken at two dwellings, one in the city center and the other in the suburbs of the Oslo metropolitan area, during summer/fall and winter/spring periods of 2002-2003. In this paper, emphasis is placed on the chemical characteristics (water-soluble ions and carbonaceous components) of fine (PM2.5) and coarse (PM2.5-10) particles and their indoor/outdoor relationship. Results demonstrate that the carbonaceous species were dominant in all fractions of the PM10 particles (cut off size: 0.09-11.31 microm) during all measurement periods, except winter 2003, when increased concentrations of water-soluble inorganic ions were predominant because of sea salt transport. The concentration of organic carbon was higher in the fine and coarse PM10 fractions indoors, whereas elemental carbon was higher indoors only in the coarse fraction. In regards to the carbonaceous species, local traffic and secondary organic aerosol formation were, probably, the main sources outdoors, whereas indoors combustion activities such as preparation of food, burning of candles, and cigarette smoking were the main sources. In contrast, the concentrations of water-soluble inorganic ions were higher outdoors than indoors. The variability of water-soluble inorganic ion concentrations outdoors was related to changes in emissions from local anthropogenic sources, long-range transport of particles, sea salt emissions, and resuspension of roadside and soil dusts. In the indoor environment the infiltration of the outdoor air indoors was the major source of inorganic ions.

Mineralogy and Textural Characteristics of Fine-grained Rims in the Yamato 791198 CM2 Carbonaceous Chondrite: Constraints on the Location of Aqueous Alteration

Science.gov (United States)

Chizmadia, Lysa J.; Brearley, Adrian J.

2003-01-01

Carbonaceous chondrites provide important clues into the nature of physical and chemical processes in the early solar system. A question of key importance concerns the role of water in solar nebular and asteroidal processes. The effects of water on primary mineral assemblages have been widely recognized in chondritic meteorites, especially the CI and CM carbonaceous chondrites. These meteorites have undergone extensive aqueous alteration that occurred prior to their arrival on Earth. In the case of the CM chondrites, this alteration has resulted in the partial to complete replacement of the primary nebular phases with secondary alteration phases. Considerable controversy exists as to the exact location where the alteration of the CM chondrites occurred. Several textural lines of evidence have been cited in support of aqueous alteration prior to the accretion of the final parent asteroid. An important line of evidence to support this hypothesis is the dis-equilibrium nature of fine-grained rims and matrix materials. [2] also noted the juxtaposition of micron-sized Fe-Ni metal grains and apparently unaltered chondrule glass against hydrated rim silicates. Conversely, there is a large body of evidence in favor of parent body alteration such as the occurrence of undisturbed Fe-rich aureoles and the systematic redistribution of elemental components over millimeters, e.g., Mg(+2) into the matrix and Fe(+2) into chondrules etc.

The Biological Potency Of Carbonaceous Nanoparticles Is Associated With The State Of Oxidation Of Surface Carbon Atoms

Science.gov (United States)

Epidemiological studies have shown that exposure to ambient particulate matter (PM) is associated with excess morbidity and mortality. An important component of PM consists of inorganic and organic compounds adsorbed onto a carbonaceous particle core. Toxicological studies indica...

Plasma treatment for producing electron emitters

Science.gov (United States)

Coates, Don Mayo; Walter, Kevin Carl

2001-01-01

Plasma treatment for producing carbonaceous field emission electron emitters is disclosed. A plasma of ions is generated in a closed chamber and used to surround the exposed surface of a carbonaceous material. A voltage is applied to an electrode that is in contact with the carbonaceous material. This voltage has a negative potential relative to a second electrode in the chamber and serves to accelerate the ions toward the carbonaceous material and provide an ion energy sufficient to etch the exposed surface of the carbonaceous material but not sufficient to result in the implantation of the ions within the carbonaceous material. Preferably, the ions used are those of an inert gas or an inert gas with a small amount of added nitrogen.

COMBINED THEORETICAL AND EXPERIMENTAL INVESTIGATION OF MECHANISMS AND KINETICS OF VAPOR-PHASE MERCURY UPTAKE BY CARBONACEOUS SURFACES; ANNUAL

International Nuclear Information System (INIS)

Radisav D. Vidic; Eric V. Borguet; Karl J. Johnson

2000-01-01

The overall goal of this research program is to gain fundamental understanding of the important chemistry and physics involved in mercury adsorption on carbonaceous surfaces. This knowledge will then be used to optimize adsorption processes and operating conditions to maximize the uptake of mercury within the required contact time. An additional long-term benefit of this research is the basic understanding of the Hg adsorption process, which may facilitate the design of new adsorbents for more efficient and cost-effective removal of Hg from a variety of effluent streams. Molecular modeling of the adsorption of Hg on carbonaceous surfaces will greatly increase the insight into the physics of the adsorption process and combined with in situ rate measurements of mercury adsorption and desorption (conventional and pulsed laser) on graphite using linear and nonlinear optical probes with real time optical resolution have the potential to provide fundamental insight into the process of mercury uptake by carbonaceous surfaces. Besides accurate assessment of key parameters influencing adsorption equilibrium, fundamental understanding of the kinetics of mercury adsorption, desorption, and diffusion will be developed in this study. These key physical and chemical processes postulated through molecular modeling efforts and verified by in situ measurements will be utilized to select (or develop) promising sorbents for mercury control, which will be tested under dynamic conditions using simulated flue gas

Preparation of carbonaceous electrodes and evaluation of their performance by electrochemical techniques

International Nuclear Information System (INIS)

Sharma, H.S.; Manolkar, R.B.; Kamat, J.V.; Marathe, S.G.; Biswas, A.R.; Kulkarni, P.G.

1994-01-01

Carbonaceous electrodes, from glassy carbon (GC), graphite rod or graphite powder, have been prepared for coulometric and voltammetric investigation. Beaker type graphite electrode of larger surface area was used as working electrode for the analysis of uranium and plutonium in solution by coulometry. Results have shown usefulness of the electrode for both uranium and plutonium analysis. Thus the graphite electrode can be used in place of mercury for uranium analysis and in place of platinum gauze for plutonium analysis. GC electrode ( from French and Indian material ), graphite or carbon paste electrode of smaller surface area prepared here have also been found to give satisfactory performance as could be observed from cyclic voltammetric (cv) patterns for standard K 9 Fe(CN) 6 /K 4 Fe(CN) 6 redox system. Especially the GC electrode, (French) polished to 1μ finish with diamond paste gave very low values (1μ amp.) of background current in 1M KCl and the difference in cathodic and anodic peak potentials (δE values) was close to 60 mV from one electron transfer. Therefore the electrode can be used for various types of electrochemical studies relating to redox potentials, reaction mechanism, kinetic parameters etc. of different electrode processes. (author). 20 refs., 3 tabs., 10 figs., 8 photographs

Long-term (2001-2012) trends of carbonaceous aerosols from a remote island in the western North Pacific: an outflow region of Asian pollutants

Science.gov (United States)

Boreddy, Suresh K. R.; Mozammel Haque, M.; Kawamura, Kimitaka

2018-01-01

The present study reports on long-term trends of carbonaceous aerosols in total suspended particulate (TSP) samples collected at Chichijima in the western North Pacific during 2001-2012. Seasonal variations of elemental carbon (EC), organic carbon (OC), and water-soluble organic carbon (WSOC) concentrations showed maxima in winter to spring and minima in summer. These seasonal differences in the concentrations of carbonaceous aerosols were associated with the outflows of polluted air masses from East Asia, which are clearly distinguishable from pristine air masses from the central Pacific. The higher concentrations of carbonaceous aerosols during winter to spring are associated with long-range atmospheric transport of East Asian continental polluted air masses, whereas lower concentrations may be due to pristine air masses from the central Pacific in summer. The annual trends of OC / EC (+0.46 % yr-1), WSOC (+0.18 % yr-1) and WSOC / OC (+0.08 % yr-1) showed significant (p Asia.

Electro-desalination of sulfate contaminated carbonaceous sandstone – risk for salt induced decay during the process

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.

2016-01-01

Sodium-sulphate is known to cause severe stone damage. This paper is focused on removal of this salt from carbonaceous sandstone by electro-desalination (ED). The research questions are related to possible stone damage during ED and subsequently suction cycles are made in distilled water before......, during and after ED. During suction in water the salts are concentrated in the upper part of the sandstone. After 2 days of treatment the average water soluble SO42- concentration was half the initial and for this sample corners were damaged as was the case for the reference stone. After 4 days of ED...... in the poultice with carbonate. The acid would be highly damaging to the carbonaceous sandstone as the binder-CaCO3 is soluble in acid. From pH measurements of the poultice it seems as if the acid is buffered well, as pH is still slightly alkaline after ED, but this is a measurement of the average pH and thus...

Water and the thermal evolution of carbonaceous chondrite parent bodies

International Nuclear Information System (INIS)

Grimm, R.E.; Mcsween, H.Y. Jr.

1989-01-01

Two hypotheses are proposed for the aqueous alteration of carbonaceous chondrites within their parent bodies, in which respectively the alteration occurs (1) throughout the parent body interior, or (2) in a postaccretional surface regolith; both models assume an initially homogeneous mixture of ice and rock that is heated through the decay of Al-26. Water is seen to exert a powerful influence on chondrite evolution through its role of thermal buffer, permitting substitution of a low temperature aqueous alteration for high temperature recrystallization. It is quantitatively demonstrated that liquid water may be introduced by either hydrothermal circulation, vapor diffusion from below, or venting due to fracture. 104 refs

Carbon-Based Materials for Photo-Triggered Theranostic Applications

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Karunya Albert

2016-11-01

Full Text Available Carbon-based nanomaterials serve as a type of smart material for photo-triggered disease theranostics. The inherent physicochemical properties of these nanomaterials facilitate their use for less invasive treatments. This review summarizes the properties and applications of materials including fullerene, nanotubes, nanohorns, nanodots and nanographenes for photodynamic nanomedicine in cancer and antimicrobial therapies. Carbon nanomaterials themselves do not usually act as photodynamic therapy (PDT agents owing to the high hydrophobicity, however, when the surface is passivated or functionalized, these materials become great vehicles for PDT. Moreover, conjugation of carbonaceous nanomaterials with the photosensitizer (PS and relevant targeting ligands enhances properties such as selectivity, stability, and high quantum yield, making them readily available for versatile biomedical applications.

Organic matter in primitive meteorites: a study of the hydrogen isotopic distribution in CM-type carbonaceous chondrites

Science.gov (United States)

Piani, L.; Yurimoto, H.; Remusat, L.; Gonzales, A.; Marty, B.

2017-12-01

Chondrite meteorites are fragments of rocks coming from small bodies of the asteroid belt and constitute witnesses of the volatile-rich reservoirs present in the inner protoplanetary disk. Among these meteorites, carbonaceous chondrites contain the largest quantity of water and organic matter and are one of the most probable candidates for the delivery of water and molecular origin of life to Earth. Organic matter in carbonaceous chondrites is intimately mixed with hydrated minerals challenging its in situ characterization and the determination of its H-isotope composition (Le Guillou et al., GCA 131, 2014). Organic matter occurs as soluble components (in water or organic solvents) and an insoluble macromolecule. The insoluble organic matter (IOM) is efficiently isolated after acid leaching of the chondrite minerals. IOM has thus been investigated by a large set of analytical techniques allowing its structural organization, chemical composition and isotopic composition to be determined at several scales (e.g. Derenne and Robert, MAPS 45, 2010). In the soluble counterpart (SOM), targeted studies have shown large ranges of D/H ratios in the different classes of soluble organic compounds (i.e. carboxylic acids, ketones and aldehydes, amino-acids etc.) (Remusat, Planetary Mineralogy 15, 2015 and references therein). This D/H distribution indicates a complex and probably multiple-stage synthesis of this organic compounds occurring at different stages of the disk evolution. Nevertheless, inventories of the known C-bearing species in carbonaceous chondrites (carbonates, SOM and IOM) show that about 40-50 % of the carbon is hidden within the matrix (Alexander et al., MAPS 50, 2015). In this study, we perform in situ hydrogen isotope analyses at the micrometer scale by secondary ion mass spectrometry to investigate the distribution of organic matter in primitive chondrites without the use of any chemical treatment. Correlated analyses of the D/H and C/H ratios allow us to

In Situ Mapping of the Organic Matter in Carbonaceous Chondrites and Mineral Relationships

Science.gov (United States)

Clemett, Simon J.; Messenger, S.; Thomas-Keprta, K. L.; Ross, D. K.

2012-01-01

Carbonaceous chondrite organic matter represents a fossil record of reactions that occurred in a range of physically, spatially and temporally distinct environments, from the interstellar medium to asteroid parent bodies. While bulk chemical analysis has provided a detailed view of the nature and diversity of this organic matter, almost nothing is known about its spatial distribution and mineralogical relationships. Such information is nevertheless critical to deciphering its formation processes and evolutionary history.

Chemical, structural and combustion characteristics of carbonaceous products obtained by hydrothermal carbonization of palm empty fruit bunches.

Science.gov (United States)

Parshetti, Ganesh K; Kent Hoekman, S; Balasubramanian, Rajasekhar

2013-05-01

A carbon-rich solid product, denoted as hydrochar, was synthesized by hydrothermal carbonization (HTC) of palm oil empty fruit bunch (EFB), at different pre-treatment temperatures of 150, 250 and 350 °C. The conversion of the raw biomass to its hydrochar occurred via dehydration and decarboxylation processes. The hydrochar produced at 350 °C had the maximum energy-density (>27 MJ kg(-1)) with 68.52% of raw EFB energy retained in the char. To gain a detailed insight into the chemical and structural properties, carbonaceous hydrochar materials were characterized by FE-SEM, FT-IR, XRD and Brunauer-Emmett-Teller (BET) analyses. This work also investigated the influence of hydrothermally treated hydrochars on the co-combustion characteristics of low rank Indonesian coal. Conventional thermal gravimetric analysis (TGA) parameters, kinetics and activation energy of different hydrochar and coal blends were estimated. Our results show that solid hydrochars improve the combustion of low rank coals for energy generation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Mineralized remains of morphotypes of filamentous cyanobacteria in carbonaceous meteorites

Science.gov (United States)

Hoover, Richard B.

2005-09-01

The quest for conclusive evidence of microfossils in meteorites has been elusive. Abiotic microstructures, mineral grains, and even coating artifacts may mimic unicellular bacteria, archaea and nanobacteria with simple spherical or rod morphologies (i.e., cocci, diplococci, bacilli, etc.). This is not the case for the larger and more complex microorganisms, colonies and microbial consortia and ecosystems. Microfossils of algae, cyanobacteria, and cyanobacterial and microbial mats have been recognized and described from many of the most ancient rocks on Earth. The filamentous cyanobacteria and sulphur-bacteria have very distinctive size ranges, complex and recognizable morphologies and visibly differentiated cellular microstructures. The taphonomic modes of fossilization and the life habits and processes of these microorganisms often result in distinctive chemical biosignatures associated with carbonization, silicification, calcification, phosphatization and metal-binding properties of their cell-walls, trichomes, sheaths and extracellular polymeric substances (EPS). Valid biogenicity is provided by the combination of a suite of known biogenic elements (that differ from the meteorite matrix) found in direct association with recognizable and distinct biological features and microstructures (e.g., uniseriate or multiseriate filaments, trichomes, sheaths and cells of proper size/size range); specialized cells (e.g., basal or apical cells, hormogonia, akinetes, and heterocysts); and evidence of growth characteristics (e.g., spiral filaments, robust or thin sheaths, laminated sheaths, true or false branching of trichomes, tapered or uniform filaments) and evidence of locomotion (e.g. emergent cells and trichomes, coiling hormogonia, and hollow or flattened and twisted sheaths). Since 1997 we have conducted Environmental and Field Emission Scanning Electron Microscopy (ESEM and FESEM) studies of freshly fractured interior surfaces of carbonaceous meteorites, terrestrial

Global climate impacts of country-level primary carbonaceous aerosol from solid-fuel cookstove emissions

International Nuclear Information System (INIS)

Lacey, Forrest; Henze, Daven

2015-01-01

Cookstove use is globally one of the largest unregulated anthropogenic sources of primary carbonaceous aerosol. While reducing cookstove emissions through national-scale mitigation efforts has clear benefits for improving indoor and ambient air quality, and significant climate benefits from reduced green-house gas emissions, climate impacts associated with reductions to co-emitted black (BC) and organic carbonaceous aerosol are not well characterized. Here we attribute direct, indirect, semi-direct, and snow/ice albedo radiative forcing (RF) and associated global surface temperature changes to national-scale carbonaceous aerosol cookstove emissions. These results are made possible through the use of adjoint sensitivity modeling to relate direct RF and BC deposition to emissions. Semi- and indirect effects are included via global scaling factors, and bounds on these estimates are drawn from current literature ranges for aerosol RF along with a range of solid fuel emissions characterizations. Absolute regional temperature potentials are used to estimate global surface temperature changes. Bounds are placed on these estimates, drawing from current literature ranges for aerosol RF along with a range of solid fuel emissions characterizations. We estimate a range of 0.16 K warming to 0.28 K cooling with a central estimate of 0.06 K cooling from the removal of cookstove aerosol emissions. At the national emissions scale, countries’ impacts on global climate range from net warming (e.g., Mexico and Brazil) to net cooling, although the range of estimated impacts for all countries span zero given uncertainties in RF estimates and fuel characterization. We identify similarities and differences in the sets of countries with the highest emissions and largest cookstove temperature impacts (China, India, Nigeria, Pakistan, Bangladesh and Nepal), those with the largest temperature impact per carbon emitted (Kazakhstan, Estonia, and Mongolia), and those that would provide the

Global climate impacts of country-level primary carbonaceous aerosol from solid-fuel cookstove emissions

Science.gov (United States)

Lacey, Forrest; Henze, Daven

2015-11-01

Cookstove use is globally one of the largest unregulated anthropogenic sources of primary carbonaceous aerosol. While reducing cookstove emissions through national-scale mitigation efforts has clear benefits for improving indoor and ambient air quality, and significant climate benefits from reduced green-house gas emissions, climate impacts associated with reductions to co-emitted black (BC) and organic carbonaceous aerosol are not well characterized. Here we attribute direct, indirect, semi-direct, and snow/ice albedo radiative forcing (RF) and associated global surface temperature changes to national-scale carbonaceous aerosol cookstove emissions. These results are made possible through the use of adjoint sensitivity modeling to relate direct RF and BC deposition to emissions. Semi- and indirect effects are included via global scaling factors, and bounds on these estimates are drawn from current literature ranges for aerosol RF along with a range of solid fuel emissions characterizations. Absolute regional temperature potentials are used to estimate global surface temperature changes. Bounds are placed on these estimates, drawing from current literature ranges for aerosol RF along with a range of solid fuel emissions characterizations. We estimate a range of 0.16 K warming to 0.28 K cooling with a central estimate of 0.06 K cooling from the removal of cookstove aerosol emissions. At the national emissions scale, countries’ impacts on global climate range from net warming (e.g., Mexico and Brazil) to net cooling, although the range of estimated impacts for all countries span zero given uncertainties in RF estimates and fuel characterization. We identify similarities and differences in the sets of countries with the highest emissions and largest cookstove temperature impacts (China, India, Nigeria, Pakistan, Bangladesh and Nepal), those with the largest temperature impact per carbon emitted (Kazakhstan, Estonia, and Mongolia), and those that would provide the

Electron microscopy of fine-grained extraterrestrial materials

International Nuclear Information System (INIS)

Mackinnon, I.D.R.; McKay, D.S.; Isaacs, A.M.; Nace, G.

1982-01-01

Electron micrographs are shown of (a) Mighei C2 carbonaceous chondrite (variety of matrix phases present; micro-diffraction patterns of a region showing small, discrete intergrowths of planar serpentine and an ordered mixed-layer material; figures showing examples of textures which may be interpreted in terms of alteration processes, and inclusions); and (b) a typical cosmic dust particle collected by high-flying aircraft in the Earth's stratosphere. The composition and morphology of the samples are discussed and their significance. (U.K.)

Structure and isotopic ratios of aliphatic side chains in the insoluble organic matter of the Murchison carbonaceous chondrite

Science.gov (United States)

Huang, Yongsong; Alexandre, Marcelo R.; Wang, Yi

2007-07-01

We report in this paper the first molecular and isotopic characterization of individual aliphatic side chains from the insoluble organic matter (IOM) in the Murchison carbonaceous chondrite using a novel combined approach of RuO 4 oxidation and solid phase microextraction (SPME). The aliphatic side chains in the IOM of Murchison were first released by oxidizing aromatic structures using RuO 4. Because the IOM of carbonaceous chondrites contains predominantly short (C 1 to C 9) aliphatic substitutions, the resulting low molecular weight monocarboxylic acids (MCAs) are highly volatile and water-soluble. The conventional aqueous extraction and derivatization procedures following RuO 4 oxidation are unable to recover MCAs for subsequent analyses. We overcame this problem by employing SPME to directly capture the MCAs from the aqueous solution. We selected a SPME fiber with greater affinity for longer chain monoacids to compensate for the exponential decline of monoacid concentrations with increasing carbon numbers in meteorite IOM, allowing more accurate identification and quantification for the less abundant monoacids. We also determined the carbon and hydrogen isotopic ratios of individual MCAs derived from Murchinson IOM. Our results reveal significant similarity in both molecular structures and hydrogen isotopic ratios between the IOM aliphatic side chains and water-soluble MCAs in Murchison, suggesting that these compounds had common precursors. Our combined new approach of RuO 4 oxidation-SPME provides a new way to probe the molecular and isotopic characteristics of aliphatic side chains in carbonaceous chondrites.

Source apportionment of the summer time carbonaceous aerosol at Nordic rural background sites

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K. E. Yttri

2011-12-01

Full Text Available In the present study, natural and anthropogenic sources of particulate organic carbon (OC_p and elemental carbon (EC have been quantified based on weekly filter samples of PM₁₀ (particles with aerodynamic diameter <10 μm collected at four Nordic rural background sites [Birkenes (Norway, Hyytiälä (Finland, Vavihill (Sweden, Lille Valby, (Denmark] during late summer (5 August–2 September 2009. Levels of source specific tracers, i.e. cellulose, levoglucosan, mannitol and the ¹⁴C/¹²C ratio of total carbon (TC, have been used as input for source apportionment of the carbonaceous aerosol, whereas Latin Hypercube Sampling (LHS was used to statistically treat the multitude of possible combinations resulting from this approach. The carbonaceous aerosol (here: TC_p; i.e. particulate TC was totally dominated by natural sources (69–86%, with biogenic secondary organic aerosol (BSOA being the single most important source (48–57%. Interestingly, primary biological aerosol particles (PBAP were the second most important source (20–32%. The anthropogenic contribution was mainly attributed to fossil fuel sources (OC_ff and EC_ff (10–24%, whereas no more than 3–7% was explained by combustion of biomass (OC_bb and EC_bb in this late summer campaign i.e. emissions from residential wood burning and/or wild/agricultural fires. Fossil fuel sources totally dominated the ambient EC loading, which accounted for 4–12% of TC_p, whereas <1.5% of EC was attributed to combustion of biomass. The carbonaceous aerosol source apportionment showed only minor variation between the four selected sites. However, Hyytiälä and Birkenes showed greater resemblance to each other, as did Lille Valby and Vavihill, the two latter being somewhat more influenced by anthropogenic sources. Ambient levels of organosulphates and nitrooxy-organosulphates in the Nordic rural

Uranium, yttrium, and rare earth elements accumulation during the Cretaceous anoxic events in carbonaceous rocks in the Pacific Ocean

Science.gov (United States)

Savelyeva, Olga; Philosofova, Tatyana; Bergal-Kuvikas, Olga; Savelyeva, Svetlana

2017-04-01

We have studied the carbonate-siliceous section of paleooceanic Albian-Cenomanian deposits on the Kamchatsky Mys peninsula (Eastern Kamchatka, Russia) [1].The section is represented by a rhythmic alternation of planktonic limestones and jaspers, accumulated in the open ocean environment. The rhythmicity can be attributed to climate variations that reflect a fluctuation of astronomical parameters (Milankovitch cycles) [2, 3].The section contains two beds enriched in organic carbon, corresponding to the two oceanic anoxic events - MCE and OAE2 [3]. The maximum content of organic matter in those beds reaches 68%. Our geochemical studies revealed an enrichment of the carbonaceous rocks in some major and trace elements including PGE, in comparison with the surrounding limestone and jasper [4].The accumulation of the ore elements in carbonaceous beds is caused by euxinic conditions during sedimentation.The content of uranium, yttrium, and rare earth elements in carbonaceous rocks is up to 60, 142 and 312 ppm respectively. Phosphate grains (bone detritus) with microinclusions of yttrium and uranium minerals were revealed in the carbonaceous rocks using the scanning electron microscope. These data prove the hypothesis of the sorbtion of U and Y by phosphate detritus from seawater. Microprobe analysis also showed an increased content of Cu, Zn, V in some pyrite framboids, which indicates that these elements are fixed in rocks by Fe-sulphide phase or organic matter under euxinic conditions. Our research may bring us closer to understanding the mechanism of syngenetic accumulation of metals in the black shales. This work was supported by the RFBR (No. 16-05-00546). [1] Palechek, T.N., Savelyev, D.P., Savelyeva, O.L. (2010) Stratigraphy and Geological Correlation 18, (1) 63-82. [2] Savelyeva, O.L. (2010). Vestnik Kraunts. Nauki o zemle 1 (15), 45-55 (in Russian). [3] Savelyev, D.P., Savelyeva, O.L., Palechek, T.N., Pokrovsky, B.G. (2012) Geophysical Research Abstracts, 14, EGU

Carbon Anode Materials

Science.gov (United States)

Ogumi, Zempachi; Wang, Hongyu

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.

Program GICC, final report (March 2005), inventory of carbonaceous aerosol particles from 1860 to 2100 or which carbonaceous aerosol for a significant climatic regional/global impact?

International Nuclear Information System (INIS)

Cachier, H.; Guinot, B.; Criqui, P.; Mima, S.; Brignon, J.M.; Penner, J.; Carmichael, G.; Gadi, R.; Denier Van der Gon, H.; Gregoire, J.M.; Liousse, C.; Michel, C.; Guillaume, B.; Junker, C.

2007-01-01

The aim of our program is to determine past, present and future emission inventories of carbonaceous particles from 1860 to 2100 for fossil fuel and biofuel sources. Emission inventories for savannah and forest fires have been developed by using burnt area products given by satellite for Asia and Africa. The strong collaboration with the different groups attending this GICC program has allowed to develop the following results. 1- With the improvement of algorithms and new choices for emission factors, emission inventories for black carbon (BC), primary organic carbon (OCp) and total organic carbon (OCtot) have been constructed for the period 1950 to 1997 for fossil fuel and biofuel sources. With these new development, biofuel sources have been seen to be significant, especially in the developing countries. 2- Past inventories have been developed for fossil fuel and biofuel sources from 1860 to 1997 by taking into account the evolution of fuel consumption, fuel use and emission factors. 3- Savannah and forest fire inventories have been constructed based on burnt area products, for Africa (1981-1991, 2000) and Asia (2000-2001). These results show the importance of using real time data instead of statistics. 4-Future emission inventory of black carbon by fossil fuel sources has been constructed for 2100 following the IPCC scenario A2 (catastrophic case) and B1 (perfect world). 5-Characterization of biofuel emissions has been realized by organizing an experiment in a combustion chamber where indian and chinese biofuels (fuelwood, agricultural wastes, dung-cake etc..). were burnt, reproducing the burning methods used in these countries. 6-Finally, the differences between the existing inventories of carbonaceous aerosols has been explained. (A.L.B.)

Studying properties of carbonaceous reducers and process of forming primary titanium slags

Directory of Open Access Journals (Sweden)

T. K. Balgabekov

2014-10-01

Full Text Available When smelting a rich titanium slag the most suitable are low-ash reducers, and the studies revealed the suitability for this purpose of special coke and coal. An important property of a reducer is its specific resistance. Therefore there were carried out studies for measuring electric resistance of briquettes consisting of ilmenite concentrate and different carbonaceous reducers. It is recommended to jointly smelt the briquetted and powdered burden (the amount of the powdered burden varies form 20 tо 50 %, this leads to the increase of technical-economic indicators of the process.

Preliminary investigation into the use of surface modification techniques to detect organic materials in meteorites

OpenAIRE

Goodyear, M. D.; Gilmour, I.; Pearson, V. K.

2011-01-01

Many carbonaceous chondrites (CCs) display evidence of aqueous and/or thermal alteration of their component minerals. In addition, CCs also contain up to ca. 5% carbon, much of which is organic, insoluble, involatile and unreactive, and known as insoluble organic material (IOM). It is not known if there is a causal connection between the mineral alteration, and formation or modification of organic materials; however by understanding the relationships between them, any connections (chemical or...

Ore-controlling mechanism of carbonaceous-siliceous-pelitic rock type uranium deposits with down-faulted red basins in the southeast continental margin of Yangtze plate

International Nuclear Information System (INIS)

Zhang Zilong; Qi Fucheng; He Zhongbo; Li Zhixing; Wang Wenquan; Yu Jinshui

2012-01-01

One of the important ore-concentrated areas of carbonaceous-siliceous-pelitic rock type uranium deposits is the Southeast continental margin of Yangtze plate. Sedimentary-exogenously transformed type and sedimentary- hydrothermal superimposed transformed type uranium deposits are always distributed at or near the edge of down-faulted red ba sins. In this paper, the distributions of the deposits are analyzed with the relation to down-faulted red basins. The connective effect and ore-controlling mechanism are proposed of carbonaceous-siliceous-pelitic rock type uranium deposits with marginal fractures of red basins. (authors)

Thermal maturity and organic composition of Pennsylvanian coals and carbonaceous shales, north-central Texas: Implications for coalbed gas potential

Energy Technology Data Exchange (ETDEWEB)

Hackley, Paul C. [U.S. Geological Survey, 956 National Center, Reston, VA 20192 (United States); Guevara, Edgar H.; Hentz, Tucker F. [Bureau of Economic Geology, The University of Texas at Austin, Austin, TX 78713 (United States); Hook, Robert W. [1301 Constant Springs Drive, Austin, TX 78746 (United States)

2009-01-31

Thermal maturity was determined for about 120 core, cuttings, and outcrop samples to investigate the potential for coalbed gas resources in Pennsylvanian strata of north-central Texas. Shallow (< 600 m; 2000 ft) coal and carbonaceous shale cuttings samples from the Middle-Upper Pennsylvanian Strawn, Canyon, and Cisco Groups in Archer and Young Counties on the Eastern Shelf of the Midland basin (northwest and downdip from the outcrop) yielded mean random vitrinite reflectance (R{sub o}) values between about 0.4 and 0.8%. This range of R{sub o} values indicates rank from subbituminous C to high volatile A bituminous in the shallow subsurface, which may be sufficient for early thermogenic gas generation. Near-surface (< 100 m; 300 ft) core and outcrop samples of coal from areas of historical underground coal mining in the region yielded similar R{sub o} values of 0.5 to 0.8%. Carbonaceous shale core samples of Lower Pennsylvanian strata (lower Atoka Group) from two deeper wells (samples from {proportional_to} 1650 m; 5400 ft) in Jack and western Wise Counties in the western part of the Fort Worth basin yielded higher R{sub o} values of about 1.0%. Pyrolysis and petrographic data for the lower Atoka samples indicate mixed Type II/Type III organic matter, suggesting generated hydrocarbons may be both gas- and oil-prone. In all other samples, organic material is dominated by Type III organic matter (vitrinite), indicating that generated hydrocarbons should be gas-prone. Individual coal beds are thin at outcrop (< 1 m; 3.3 ft), laterally discontinuous, and moderately high in ash yield and sulfur content. A possible analog for coalbed gas potential in the Pennsylvanian section of north-central Texas occurs on the northeast Oklahoma shelf and in the Cherokee basin of southeastern Kansas, where contemporaneous gas-producing coal beds are similar in thickness, quality, and rank. (author)

Looking for Fossil Bacteria in Martian Materials

Science.gov (United States)

Westall, F.; Walsh, M. M.; Mckay, D. D.; Wentworth, S.; Gibson, E. K.; Steele, A.; Toporski, J.; Lindstrom, D.; Martinez, R.; Allen, C. C.

1999-01-01

The rationale for looking for prokaryote fossils in Martian materials is based on our present understanding of the environmental evolution of that planet in comparison to the history of the terrestrial environments and the development and evolution of life on Earth. On Earth we have clear, albeit indirect, evidence of life in 3.8 b.y.-old rocks from Greenland and the first morphological fossils in 3.3-3.5 b.y.-old cherts from South Africa and Australia. In comparison, Mars, being smaller, probably cooled down after initial aggregation faster than the Earth. Consequently, there could have been liquid water on its surface earlier than on Earth. With a similar exogenous and endogenous input of organics and life-sustaining nutrients as is proposed for the Earth, life could have arisen on that planet, possibly slightly earlier dm it did on Earth. Whereas on Earth liquid water has remained at the surface of the planet since about 4.4 b.y. (with some possible interregnums caused by planet-sterilising impacts before 3.8. b.y. and perhaps a number of periods of a totally frozen Earth, this was not the case with Mars. Although it is not known exactly when surficial water disappeared from the surface, there would have been sufficient time for life to have developed into something similar to the terrestrial prokaryote stage. However, given the earlier environmental deterioration, it is unlikely that it evolved into the eukaryote stage and even evolution of oxygenic photosynthesis may not have been reached. Thus, the impetus of research is on single celled life simnilar to prokaryotes. We are investigating a number of methods of trace element analysis with respect to the Early Archaean microbial fossils. Preliminary neutron activation analysis of carbonaceous layers in the Early Archaean cherts from South Africa and Australia shows some partitioning of elements such as As, Sb, Cr with an especial enrichment of lanthanides in a carbonaceous-rich banded iron sediment . More

Light absorption of biomass burning and vehicle emission-sourced carbonaceous aerosols of the Tibetan Plateau.

Science.gov (United States)

Hu, Zhaofu; Kang, Shichang; Li, Chaoliu; Yan, Fangping; Chen, Pengfei; Gao, Shaopeng; Wang, Zhiyong; Zhang, Yulan; Sillanpää, Mika

2017-06-01

Carbonaceous aerosols over the Tibetan Plateau originate primarily from biomass burning and vehicle emissions (BB and VEs, respectively). The light absorption characteristics of these carbonaceous aerosols are closely correlated with the burning conditions and represent key factors that influence climate forcing. In this study, the light absorption characteristics of elemental carbon (EC) and water-soluble organic carbon (WSOC) in PM 2.5 (fine particulate matter smaller than 2.5 μm) generated from BB and VEs were investigated over the Tibetan Plateau (TP). The results showed that the organic carbon (OC)/EC ratios from BB- and VE-sourced PM 2.5 were 17.62 ± 10.19 and 1.19 ± 0.36, respectively. These values were higher than the ratios in other regions, which was primarily because of the diminished amount of oxygen over the TP. The mass absorption cross section of EC (MAC EC ) at 632 nm for the BB-sourced PM 2.5 (6.10 ± 1.21 m 2 .g -1 ) was lower than that of the VE-sourced PM 2.5 (8.10 ± 0.98 m 2 .g -1 ), indicating that the EC content of the BB-sourced PM 2.5 was overestimated because of the high OC/EC ratio. The respective absorption per mass (α/ρ) values at 365 nm for the VE- and BB-sourced PM 2.5 were 0.71 ± 0.17 m 2 .g -1 and 0.91 ± 0.18 m 2 .g -1 . The α/ρ value of the VEs was loaded between that of gasoline and diesel emissions, indicating that the VE-sourced PM 2.5 originated from both types of emissions. Because OC and WSOC accounts for most of the carbonaceous aerosols at remote area of the TP, the radiative forcing contributed by the WSOC should be high, and requires further investigation.

Microwave-assisted and carbonaceous catalytic pyrolysis of crude glycerol from biodiesel waste for energy production

International Nuclear Information System (INIS)

Ng, Jo-Han; Leong, Swee Kim; Lam, Su Shiung; Ani, Farid Nasir; Chong, Cheng Tung

2017-01-01

Highlights: • Crude glycerol is pyrolysed catalytically via microwave irradiation to produce bioenergy. • Carbonaceous catalyst elevates pyrolysis temperature and promotes selectivity towards H_2 production. • Synthesis gas consisting of mainly H_2 and CH_4 was predominantly produced at long residence time and high temperature. • Production of bio-oil consisting of oxygenated compounds peaks at intermediate carrier gas flow rate. • Energy profit analysis shows positive energy gained with increasing residence time and decreasing reaction temperature. - Abstract: Biodiesel proliferation as a sustainable fuel has led to a glut of crude glycerol as co-product. This scenario made a previously lucrative co-product in the food and pharmaceutical sectors into a bioresource waste. The present study investigates the utilisation of a microwave-assisted pyrolysis technique to convert crude glycerol from biodiesel waste into usable bioenergy source. Operating conditions ranged from a temperature of 300–800 °C at carrier gas flow rates of 100–2000 mL/min, with the effects of carbonaceous catalyst on the selectivity of reaction pathway being investigated. Within the aforementioned conditions, the proportion of products phases is mainly dependent on the residence time inside the quartz reactor, followed by the reaction temperature. This is due to the combined factors of the reaction sequence and provision of activation energy to change product phases. The third factor of carbonaceous catalyst shows a predisposition towards hydrogen gas selectivity, leading to a lower overall gaseous product mass when factoring in products from all phases. An analysis of the energy content revealed that overall energy profit increases with decreasing temperature and increasing residence time. This concurs with solid energy content increasing in the same conditions, while it increases for liquid and gaseous products with decreasing temperature and flow rate, respectively. The

Carbon air pollution reflected in deposits on chosen building materials of Prague Castle

Czech Academy of Sciences Publication Activity Database

Sýkorová, Ivana; Havelcová, Martina; Zeman, Antonín; Trejtnarová, Hana

2011-01-01

Roč. 409, č. 21 (2011), s. 4606-4611 ISSN 0048-9697 R&D Projects: GA AV ČR IAA300460804 Institutional research plan: CEZ:AV0Z30460519; CEZ:AV0Z20710524 Keywords : historical building materials * air pollution * carbonaceous matter Subject RIV: DD - Geochemistry Impact factor: 3.286, year: 2011 http://www.sciencedirect.com/science/article/pii/S0048969711007431

Characterization, Long-Range Transport and Source Identification of Carbonaceous Aerosols during Spring and Autumn Periods at a High Mountain Site in South China

Directory of Open Access Journals (Sweden)

Hong-yan Jia

2016-09-01

Full Text Available PM10 (particulate matter samples were collected at Mount Lu, a high elevation mountain site in south China (August and September of 2011; and March, April and May of 2012. Eight carbonaceous fractions of particles were analyzed to characterize the possible carbonaceous emission sources. During the sampling events, daily average concentrations of PM10 at Mount Lu were 97.87 μg/m3 and 73.40 μg/m3 in spring and autumn, respectively. The observed mean organic carbon (OC and element carbon (EC concentrations during spring in PM10 were 10.58 μg/m3 and 2.58 μg/m3, respectively, and those in autumn were 6.89 μg/m3 and 2.40 μg/m3, respectively. Secondary organic carbon concentration was 4.77 μg/m3 and 2.93 μg/m3 on average, accounting for 28.0% and 31.0% of the total OC in spring and autumn, respectively. Relationships between carbonaceous species and results of principal component analysis showed that there were multiple sources contributing to the carbonaceous aerosols at the observation site. Through back trajectory analysis, it was found that air masses in autumn were mainly transported from the south of China, and these have the highest OC but lowest EC concentrations. Air masses in spring transported from northwest China bring 7.77 μg/m3 OC and 2.28 μg/m3 EC to the site, with lower levels coming from other sites. These air mass sources were featured by the effective carbon ratio (ECR.

Geological Structure and Gold Mineralization of Carbonaceous Deposits of the Tyotechnaya Mountain (South Urals)

OpenAIRE

A. V. Snachev; E. P. Shchulkin

2018-01-01

This paper considers the geological structure of the northern part of the East-Urals Trough. Particular attention is paid to the Kosobrodskaya Formation, where the carbonaceous deposits are most abundant. It was found that the gold in the black shales of the Tyotechnaya Mountain is associated with the intensively dislocated, silicified and sulfidised rocks struck with the diorite porphyry of the Birgildin-Tomino Complex. Channel sampling on the number of wells showed the gold grades up to 1.5...

Sustainable Materials for Sustainable Energy Storage: Organic Na Electrodes

Science.gov (United States)

Oltean, Viorica-Alina; Renault, Stéven; Valvo, Mario; Brandell, Daniel

2016-01-01

In this review, we summarize research efforts to realize Na-based organic materials for novel battery chemistries. Na is a more abundant element than Li, thereby contributing to less costly materials with limited to no geopolitical constraints while organic electrode materials harvested from biomass resources provide the possibility of achieving renewable battery components with low environmental impact during processing and recycling. Together, this can form the basis for truly sustainable electrochemical energy storage. We explore the efforts made on electrode materials of organic salts, primarily carbonyl compounds but also Schiff bases, unsaturated compounds, nitroxides and polymers. Moreover, sodiated carbonaceous materials derived from biomasses and waste products are surveyed. As a conclusion to the review, some shortcomings of the currently investigated materials are highlighted together with the major limitations for future development in this field. Finally, routes to move forward in this direction are suggested. PMID:28773272

Natural Radionuclides and Isotopic Signatures for Determining Carbonaceous Aerosol Sources, Aerosol Lifetimes, and Washout Processes

International Nuclear Information System (INIS)

Gaffney, Jeffrey

2012-01-01

This is the final technical report. The project description is as follows: to determine the role of aerosol radiative forcing on climate, the processes that control their atmospheric concentrations must be understood, and aerosol sources need to be determined for mitigation. Measurements of naturally occurring radionuclides and stable isotopic signatures allow the sources, removal and transport processes, as well as atmospheric lifetimes of fine carbonaceous aerosols, to be evaluated.

Natural Radionuclides and Isotopic Signatures for Determining Carbonaceous Aerosol Sources, Aerosol Lifetimes, and Washout Processes

Energy Technology Data Exchange (ETDEWEB)

Gaffney, Jeffrey [Univ. of Arkansas, Little Rock, AR (United States)

2012-12-12

This is the final technical report. The project description is as follows: to determine the role of aerosol radiative forcing on climate, the processes that control their atmospheric concentrations must be understood, and aerosol sources need to be determined for mitigation. Measurements of naturally occurring radionuclides and stable isotopic signatures allow the sources, removal and transport processes, as well as atmospheric lifetimes of fine carbonaceous aerosols, to be evaluated.

Raman spectra of carbonaceous materials in a fault zone in the Longmenshan thrust belt, China; comparisons with those of sedimentary and metamorphic rocks

Science.gov (United States)

Kouketsu, Yui; Shimizu, Ichiko; Wang, Yu; Yao, Lu; Ma, Shengli; Shimamoto, Toshihiko

2017-03-01

We analyzed micro-Raman spectra of carbonaceous materials (CM) in natural and experimentally deformed fault rocks from Longmenshan fault zone that caused the 2008 Wenchuan earthquake, to characterize degree of disordering of CM in a fault zone. Raman spectral parameters for 12 samples from a fault zone in Shenxigou, Sichuan, China, all show low-grade structures with no graphite. Low crystallinity and δ13C values (-24‰ to -25‰) suggest that CM in fault zone originated from host rocks (Late Triassic Xujiahe Formation). Full width at half maximum values of main spectral bands (D1 and D2), and relative intensities of two subbands (D3 and D4) of CM were variable with sample locations. However, Raman parameters of measured fault rocks fall on established trends of graphitization in sedimentary and metamorphic rocks. An empirical geothermometer gives temperatures of 160-230 °C for fault rocks in Shenxigou, and these temperatures were lower for highly sheared gouge than those for less deformed fault breccia at inner parts of the fault zone. The lower temperature and less crystallinity of CM in gouge might have been caused by the mechanical destruction of CM by severe shearing deformation, or may be due to mixing of host rocks on the footwall. CM in gouge deformed in high-velocity experiments exhibits slight changes towards graphitization characterized by reduction of D3 and D4 intensities. Thus low crystallinity of CM in natural gouge cannot be explained by our experimental results. Graphite formation during seismic fault motion is extremely local or did not occur in the study area, and the CM crystallinity from shallow to deep fault zones may be predicted as a first approximation from the graphitization trend in sedimentary and metamorphic rocks. If that case, graphite may lower the friction of shear zones at temperatures above 300 °C, deeper than the lower part of seismogenic zone.

Development of a preparation system for the radiocarbon analysis of organic carbon in carbonaceous aerosols in China

International Nuclear Information System (INIS)

Zhang, Y.L.; Liu, D.; Shen, C.D.; Ding, P.; Zhang, G.

2010-01-01

Carbonaceous aerosols comprising a large fraction of elemental carbon (EC) and organic carbon (OC) are considered to affect both global climate and human health. Radiocarbon measurements have been proved to be a useful isotopic tracer for distinguishing contemporary and fossil emissions. An optimized system of a two-step thermal preparation system for radiocarbon ( 14 C) measurement of OC/TC is firstly established in China. In this system, OC/TC are converted into carbon dioxide under a pure oxygen flow at 340 o C/650 o C and then reduced to graphite for AMS target using the method of zinc reduction. Afterwards, radiocarbon measurements of the targets performed by the NEC Compact AMS System at the Institute of Heavy Ion Physics, Peking University. The measured results for estimated reference martial including HOx I, HOx II and IAEA-C6 are consistent with internationally accepted values. The radiocarbon-based source appointment of carbonaceous aerosols in China would be much more convenient and faster with the preparation system developed in this work.

High resolution TEM of chondritic carbonaceous matter: Metamorphic evolution and heterogeneity

Science.gov (United States)

Le Guillou, Corentin; Rouzaud, Jean-Noël.; Bonal, Lydie; Quirico, Eric; Derenne, Sylvie; Remusat, Laurent

2012-03-01

The insoluble carbonaceous matter from 12 chondrites (CI, CM, CO, CV, EH, and UOC), was characterized by high resolution transmission electron microscopy (HRTEM). Besides ubiquitous nanoglobules, the insoluble organic matter from petrologic type 1 and 2 chondrites and Semarkona (LL 3.0) is composed of a highly disordered polyaromatic component. No structural differences were observed between these IOMs, in agreement with the limited thermal metamorphism they all experienced. In chondrites of petrologic type >3.0, the evolution of the IOM is controlled by the extent of thermal metamorphism. The polyaromatic layers, shorter than 1 nm in petrologic type ≤3.0 chondrites, grow up to sizes between 5 and 10 nm in petrologic type >3.6 chondrites, contributing to the increase of the degree of structural order. In addition, we find rare, but ubiquitous onion-like carbons, which may be the product of nanodiamond graphitization. The insoluble carbonaceous matter of the enstatite chondrite Sahara 97096 (EH 3) is different from the other meteorites studied here. It is more heterogeneous and displays a high abundance of graphitized particles. This may be the result of a mixture between (1) the disordered carbon located in the matrix, and (2) catalytic graphitized phases associated with metal, potentially originating from partial melting events. The structural and nanostructural evolution are similar in all IOMs. This suggests that the structure of the accreted precursors and the parent body conditions of their secondary thermal modifications (temperature, duration, and pressure) were similar. The limited degree of organization of the most metamorphosed IOMs compared with terrestrial rocks submitted to similar temperature suggests that the conditions are not favorable to graphitization processes, due to the chemical nature of the precursor or the lack of confinement pressure.

On the Q-phase of carbonaceous chondrites

International Nuclear Information System (INIS)

Vis, R.D.; Heymann, D.

1999-01-01

One of the unresolved puzzles of meteoritics is the nature of the carrier of the so-called heavy planetary gases. Apparently, these gases reside mainly in a minor fraction, which has been dubbed Q by Lewis et al. [R.S. Lewis, B. Srinivasan, E. Anders, Science 190 (1975) 1251] in analogy of the naming by Papanastasiou et al. [D.A. Papanastassiou, G.J. Wasserburg, Earth Planet. Sci. Lett. 11 (1971) 37] of a minor glassy phase in lunar rocks highly enriched in trace elements such as Pb and U. Q stands for the archaic term quintessence, the fifth or last and highest substance in ancient and medieval philosophy above fire, air, water and earth. In this contribution, an attempt is made to provide evidence that Q is carbonaceous, with carbon in the form of closed structures such as carbon nanotubes which serve as micro bottles for the heavy noble gases. To this end, Q was characterised with micro-PIXE and NRA, whereas HREM was used to search for nanotubes. Q itself was obtained as residue after chemical destruction of samples of Allende, Leoville and Vigarano

Variability of carbonaceous aerosols in remote, rural, urban and industrial environments in Spain: implications for air quality policy

Science.gov (United States)

Querol, X.; Alastuey, A.; Viana, M.; Moreno, T.; Reche, C.; Minguillón, M. C.; Ripoll, A.; Pandolfi, M.; Amato, F.; Karanasiou, A.; Pérez, N.; Pey, J.; Cusack, M.; Vázquez, R.; Plana, F.; Dall'Osto, M.; de la Rosa, J.; Sánchez de la Campa, A.; Fernández-Camacho, R.; Rodríguez, S.; Pio, C.; Alados-Arboledas, L.; Titos, G.; Artíñano, B.; Salvador, P.; García Dos Santos, S.; Fernández Patier, R.

2013-07-01

We interpret here the variability of levels of carbonaceous aerosols based on a 12 yr database from 78 monitoring stations across Spain specially compiled for this article. Data did not evidence any spatial trends of carbonaceous aerosols across the country. Conversely, results show marked differences in average concentrations from the cleanest, most remote sites (around 1 μg m-3 of non-mineral carbon (nmC), mostly made of organic carbon (OC) with very little elemental carbon (EC), around 0.1 μg m-3; OC / EC = 12-15), to the highly polluted major cities (8-10 μg m-3 of nmC; 3-4 μg m-3 of EC; 4-5 μg m-3 of OC; OC / EC = 1-2). Thus, urban (and very specific industrial) pollution was found to markedly increase levels of carbonaceous aerosols in Spain, with much lower impact of biomass burning and of biogenic emissions. Correlations between yearly averaged OC / EC and EC concentrations adjust very well to a potential equation (OC = 3.37 EC0.326, R2 = 0.8). A similar equation is obtained when including average concentrations obtained at other European sites (OC = 3.60EC0.491, R2 = 0.7). A clear seasonal variability in OC and EC concentrations was detected. Both OC and EC concentrations were higher during winter at the traffic and urban sites, but OC increased during the warmer months at the rural sites. Hourly equivalent black carbon (EBC) concentrations at urban sites accurately depict road traffic contributions, varying with distance from road, traffic volume and density, mixing-layer height and wind speed. Weekday urban rush-hour EBC peaks are mimicked by concentrations of primary gaseous emissions from road traffic, whereas a single midday peak is characteristic of remote and rural sites. Decreasing annual trends for carbonaceous aerosols were observed between 1999 and 2011 at a large number of stations, probably reflecting the impact of the EURO4 and EURO5 standards in reducing the diesel PM emissions. This has resulted in some cases in an increasing trend for

Simulating the formation of carbonaceous aerosol in a European Megacity (Paris) during the Megapoli summer and winter campaigns

NARCIS (Netherlands)

Fountoukis, C.; Megaritis, A.G.; Skyllakou, K.; Charalampidis, P.E.; Denier van der Gon, H.A.C.; Crippa, M.; Prevot, A.S.H.; Fachinger, F.; Wiedensohler, A.; Pilinis, C.; Pandis, S.N.

2016-01-01

We use a three-dimensional regional chemical transport model (PMCAMx) with high grid resolution and high-resolution emissions (4 x 4 km2) over the Paris greater area to simulate the formation of carbonaceous aerosol dur-ing a summer (July 2009) and a winter (January/February 2010) period as part of

Low-temperature method of, and apparatus for, removing the vaporizable contents from carbonaceous materials

Energy Technology Data Exchange (ETDEWEB)

Russell, A C; Garven, C W

1937-03-25

Consisting in subjecting the material in the absence of air and oxygen and presence of natural quartz as catalyzing material to requisite heat in a retort resulting from heat applied thereto externally and from reducing gas supplied thereinto.

Heat storage properties of organic phase-change materials confined in the nanospace of mesoporous SBA-15 and CMK-3.

Science.gov (United States)

Kadoono, Tomosuke; Ogura, Masaru

2014-03-28

A novel type of material encapsulating phase-change materials (PCMs) is reported concerning their implication for use as thermal energy storage devices. The composites of siliceous SBA-15 or carbonaceous CMK-3 mesoporous assemblies and organic PCMs could be used to make leak-free devices that retain their capabilities over many thermal cycles for heat storage/release. A confinement effect was observed that alters the thermal properties of the encapsulated PCM, especially in CMK-3 without any similar effects in other carbon materials.

Analysis of the saturated hydrocarbon in coal, carbonaceous mudstone and oils from the lower Jurassic coal measures in the Turpan Basin by GC/MS

International Nuclear Information System (INIS)

Fang Xuan; Meng Qianxiang; Sun Minzhuo; Du Li; Ding Wanren

2005-01-01

Saturated hydrocarbon of coal, carbonaceous mudstone and oils from the Lower Jurassic coal measures in the Turpan basin were studied, and biomarker characteristics and coal thermal maturity analyzed to draw the following conclusions. T here are many similar biomarker characteristics between oil from middle-lower Jurassic of Turpan Basin and coal and carbonaceous mudstone in the same strata. They all contain specific r-lupane, I-norbietane, C 24 -tetracyclic and high content of C 29 -steranes. These characteristics suggest that they have similar matter source of the organic matter derived from matter with abundant high plants. Meanwhile, biomarkers often used to indicate depositional environments characterized by high Pr/Ph ratio, little or no gammacerane and high abundance dibenzofurans, such biomarker distributions are indicative of suboxic and freshwater environment. Although coal and carbonaceous mudstone remain in lower thermal maturity (Ro=0.47-0.53), but C 29 -ββ/(αα+ββ) sterane ratio (0.294-0.489) and bezohopane are detected. Because these ferture are related to bacterial activity, bacterial degradation of organic matter maybe take an important role in coal-derived oil. (authors)

Catalytic production of Jatropha biodiesel and hydrogen with magnetic carbonaceous acid and base synthesized from Jatropha hulls

International Nuclear Information System (INIS)

Zhang, Fan; Tian, Xiao-Fei; Fang, Zhen; Shah, Mazloom; Wang, Yi-Tong; Jiang, Wen; Yao, Min

2017-01-01

Graphical abstract: Jatropha seeds were extracted oil for biodiesel production and the hulls were carbonized to load active sites as magnetic carbonaceous solid acid and base catalysts. Crude Jatropha oil was esterified to decrease its acid value to 1.3 from 17.2 mg KOH/g by the solid acid, and subsequently transesterified to biodiesel (96.7% yield) catalyzed by the solid base. After 3 cycles and magnetically separated, the deactivated base was catalyzed the hydrothermal gasification of biodiesel by-product (crude glycerol) with gasification rate of 81% and 82% H_2 purity. - Highlights: • High acid value (AV) crude oil was extracted from Jatropha seeds with waste hulls produced. • Carbonizing the hulls and loading active sites produced magnetic carbonaceous acid and base. • The acid reduced AV of crude oil to 1.3 from 17.2 mg KOH/g and separated for 3 cycles. • The base achieved 97.5% biodiesel yield and magnetically separated for recycles. • After 3 cycles, the deactivated base catalyzed the hydrothermal gasification of glycerol. - Abstract: Magnetic carbonaceous solid acid (C-SO_3H@Fe/JHC) and base (Na_2SiO_3@Ni/JRC) catalysts were synthesized by loading active groups on the carbonaceous supporters derived from Jatropha-hull hydrolysate and hydrolysis residue. Characterization of their morphology, magnetic saturation, functional groups and total acid/base contents were performed by various techniques. Additional acidic functional groups that formed with Jatropha-hull hydrolysate contributed to the high acidity of C-SO_3H@Fe/JHC catalyst for the pretreatment (esterification) of crude Jatropha oil with high acid values (AV). The AV of esterified Jatropha oil dropped down from 17.2 to 1.3 mg KOH/g, achieving a high biodiesel yield of 96.7% after subsequent transesterification reaction with Na_2SiO_3@Ni/JRC base that was cycled at least 3 times with little loss of catalysis activity. Both solid acid and base catalysts were easily recovered by magnetic force

The significant role of carboxylated carbonaceous fragments in the electrochemistry of carbon nanotubes.

Science.gov (United States)

Ma, Xiao; Jia, Li; Zhang, Lu; Zhu, Liande

2014-04-01

Carbon nanotubes (CNTs) have been widely employed as electrode materials in diverse branches of electrochemistry, which are claimed to display dramatically improved electrochemical behaviour compared to the conventional carbon materials. But a series of recent publications have demonstrated that the electrocatalysis of CNTs might be due to the presence of some impurities, such as metallic catalysts, nanographitic particles and amorphous carbon. For this reason, CNTs are usually purified or treated with nitric acid or nitric and sulphuric acid prior to their versatile applications. However, the strong acidic and oxidative conditions are so aggressive that serious erosion of the tube structures has inevitably taken place, which creates defects on the sidewalls and gives rise to numerous molecular byproducts, commonly referred as carboxylated carbonaceous fragments (CCFs). The adsorption of CCFs on CNTs greatly alters the surface conditions of CNTs which may significantly impact on their electrochemical properties. To this end, we wish to disclose whether the electrocatalysis of the nitric acid purified CNTs is affected by the adsorption of the CCFs. Ascorbic acid (AA) and β-nicotinamide adenine dinucleotide (NADH) as selected as the targeting benchmarks that are known to be insensitive to the presence of metallic impurities, which may guarantee the preclusion of the promoting contributions from the metallic catalysts resident in CNTs. We have demonstrated that the electrocatalytic activities of the CNTs are actually dominated by the adsorbed CCFs generated during the acidic pre-treatment. After removal of the CCFs by base rinse, the electrocatalytic properties of CNTs are greatly deteriorated and degraded to the level similar to the conventional graphite powder. We believe this finding is particularly meaningful to uncover the mysterious electrocatalysis of CNTs. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fuel cells for electricity generation from carbonaceous fuels

Energy Technology Data Exchange (ETDEWEB)

Ledjeff-Hey, K; Formanski, V; Roes, J [Gerhard-Mercator- Universitaet - Gesamthochschule Duisburg, Fachbereich Maschinenbau/Fachgebiet Energietechnik, Duisburg (Germany); Heinzel, A [Fraunhofer Inst. for Solar Energy Systems (ISE), Freiburg (Germany)

1998-09-01

Fuel cells, which are electrochemical systems converting chemical energy directly into electrical energy with water and heat as by-products, are of interest as a means of generating electricity which is environmentally friendly, clean and highly efficient. They are classified according to the electrolyte used. The main types of cell in order of operating temperature are described. These are: alkaline fuel cells, the polymer electrolyte membrane fuel cell (PEMFC); the phosphoric acid fuel cell (PAFC); the molten carbonate fuel cell (MCFC); the solid oxide fuel cell (SOFC). Applications depend on the type of cell and may range from power generation on a large scale to mobile application in cars or portable systems. One of the most promising options is the PEM-fuel cell stack where there has been significant improvement in power density in recent years. The production from carbonaceous fuels and purification of the cell fuel, hydrogen, is considered. Of the purification methods available, hydrogen separation by means of palladium alloy membranes seems particular effective in reducing CO concentrations to the low levels required for PEM cells. (UK)

Pyrolysis oil from carbonaceous solid wastes in Malaysia

International Nuclear Information System (INIS)

Islam, M.N.; Jamil, M.K.; Ani, F.N.; Zailani, R.

2000-01-01

The agro-industrial sector of Malaysia produces a huge amount of oil palm and paddy rice. These generate a significant amount of renewable biomass solid wastes in the forms of oil palm shell and rice husk. Apart from this a huge quantity of scrap tyre is generated from the country's faster increasing usage of transportation vehicles like motorcycle, car, bus and lorries. These wastes are producing pollution and disposal problems affecting the environment. Besides energy is not recovered efficiently from these waste resources. From the elemental composition and thermogravimetric analysis (TGA) studies of the wastes, it appeared that the wastes could be used for pyrolysis liquid oil production. Pyrolysis at present is deemed to be a potential method for the conversion of carbonaceous solid wastes into upgraded liquid products which can either be tried for liquid fuel or value-added chemical. A fluidized bed bench scale fast pyrolysis system was employed for this thermochemical conversion process of solid wastes. Silica sand was used as fluidized bed material and nitrogen gas as the fluidising medium. The products obtained were liquid oil, solid char and gas. The liquid oil and solid char were collected separately while the gas was flared. The maximum liquid product yield was found to vary with feedstock material fluidized bed temperature. The maximum liquid product yield was found to be 58, 53 and 40 wt. % of biomass fed at fluidized bed temperature at 500, 525 and 450 0 C respectively for oil palm shell, scrap tyre and rice husk. The solid char yield was 25, 36 and 53 wt. % of biomass fed at the condition of maximum liquid product yield for oil palm shell, scrap tyre and rice husk respectively. The oil products were subjected to FTIR, GC and GC/MS analysis for their group composition and detailed chemical compositions. The pyrolysis oil from scrap tyre was found to contain highest percentage of pure hydrocarbons (25 wt. % of total feed) with esters and oxygenated

Aqueous Alteration of Carbonaceous Chondrites: New Insights from Comparative Studies of Two Unbrecciated CM2 Chondrites, Y 791198 and ALH 81002

Science.gov (United States)

Chizmadia, L. J.; Brearley, A. J.

2004-01-01

Carbonaceous chondrites are an important resource for understanding the physical and chemical conditions in the early solar system. In particular, a long-standing question concerns the role of water in the cosmochemical evolution of carbonaceous chondrites. It is well established that extensive hydration of primary nebular phases occurred in the CM and CI chondrites, but the location where this alteration occurred remains controversial. In the CM2 chondrites, hydration formed secondary phases such as serpentine, tochilinite, pentlandite, carbonate and PCP. There are several textural observations which suggest that alteration occurred before the accretion of the final CM parent asteroid, i.e. preaccretionary alteration. Conversely, there is a significant body of evidence that supports parent-body alteration. In order to test these two competing hypotheses further, we studied two CM chondrites, Y-791198 and ALH81002, two meteorites that exhibit widely differing degrees of aqueous alteration. In addition, both meteorites have primary accretionary textures, i.e. experienced minimal asteroidal brecciation. Brecciation significantly complicates the task of unraveling alteration histories, mixing components that have been altered to different degrees from different locations on the same asteroidal parent body. Alteration in Y-791198 is mostly confined to chondrule mesostases, FeNi metal and fine-grained matrix and rims. In comparison, the primary chondrule silicates in ALH81002 have undergone extensive replacement by secondary hydrous phases. This study focuses on compositional and textural relationships between chondrule mesostasis and the associated rim materials. Our hypothesis is: both these components are highly susceptible to aqueous alteration and should be sensitive recorders of the alteration process. For parent body alteration, we expect systematic coupled mineralogical and compositional changes in rims and altered mesostasis, as elemental exchange between these

Indigenous Carbonaceous Phases Embedded Within Surface Deposits on Apollo 17 Volcanic Glass Beads

Science.gov (United States)

Thomas-Keprta, K. L.; Clemett, S. J.; Ross, D. K.; Le, L.; McKay, D. S.; Gibson, E. K.; Gonzalez, C.

2012-01-01

The assessment of indigenous organic matter in returned lunar samples was one of the primary scientific goals of the Apollo program. Prior studies of Apollo samples have shown the total amount of organic matter to be in the range of approx 50 to 250 ppm. Low concentrations of lunar organics may be a consequence not only of its paucity but also its heterogeneous distribution. Several processes should have contributed to the lunar organic inventory including exogenous carbonaceous accretion from meteoroids and interplanetary dust particles, and endogenous synthesis driven by early planetary volcanism and cosmic and solar radiation.

An review on geology study of carbonaceous-siliceous-pelitic rock type uranium deposit in China and the strategy for its development

International Nuclear Information System (INIS)

Zhao Fengmin

2009-01-01

Carbonaceous-siliceous-pelitic rock type uranium deposit was founded by Chinese uranium geologist, it refers to the uranium deposit hosted by non or light metamophosed carbonate,siliceous rock, pelitic rock and their intermediates. It is one of the important types uranium deposit in China. A lot of this type deposits have been discovered in China and their temporal-spatial distribution pattern and mineralization features have been basically identified, and the rich experience have layed a good foundation for the future exploration. Although the ore of this type is not favourable economically, it is still available. Because carbonaceous-siliceous-pelitic rock type uranium deposit has great resource potential, metallogenic study and exploration efforts should be projected differentially according to their economic profit so as to meet the uranium resource demand of nuclear power development in China. (authors)

Role of air bubbles overlooked in the adsorption of perfluorooctanesulfonate on hydrophobic carbonaceous adsorbents.

Science.gov (United States)

Meng, Pingping; Deng, Shubo; Lu, Xinyu; Du, Ziwen; Wang, Bin; Huang, Jun; Wang, Yujue; Yu, Gang; Xing, Baoshan

2014-12-02

Hydrophobic interaction has been considered to be responsible for adsorption of perfluorooctanesulfonate (PFOS) on the surface of hydrophobic adsorbents, but the long C-F chain in PFOS is not only hydrophobic but also oleophobic. In this study, for the first time we propose that air bubbles on the surface of hydrophobic carbonaceous adsorbents play an important role in the adsorption of PFOS. The level of adsorption of PFOS on carbon nanotubes (CNTs), graphite (GI), graphene (GE), and powdered activated carbon (PAC) decreases after vacuum degassing. Vacuum degassing time and pressure significantly affect the removal of PFOS by these adsorbents. After vacuum degassing at 0.01 atm for 36 h, the extent of removal of PFOS by the pristine CNTs and GI decreases 79% and 74%, respectively, indicating the main contribution of air bubbles to PFOS adsorption. When the degassed solution is recontacted with air during the adsorption process, the removal of PFOS recovers to the value obtained without vacuum degassing, further verifying the key role of air bubbles in PFOS adsorption. By theoretical calculation, the distribution of PFOS in air bubbles on the adsorbent surfaces is discussed, and a new schematic sorption model of PFOS on carbonaceous adsorbents in the presence of air bubbles is proposed. The accumulation of PFOS at the interface of air bubbles on the adsorbents is primarily responsible for its adsorption, providing a new mechanistic insight into the transport, fate, and removal of PFOS.

Agglomeration processes in carbonaceous dusty plasmas, experiments and numerical simulations

International Nuclear Information System (INIS)

Dap, S; Hugon, R; De Poucques, L; Bougdira, J; Lacroix, D; Patisson, F

2010-01-01

This paper deals with carbon dust agglomeration in radio frequency acetylene/argon plasma. Two studies, an experimental and a numerical one, were carried out to model dust formation mechanisms. Firstly, in situ transmission spectroscopy of dust clouds in the visible range was performed in order to observe the main features of the agglomeration process of the produced carbonaceous dust. Secondly, numerical simulation tools dedicated to understanding the achieved experiments were developed. A first model was used for the discretization of the continuous population balance equations that characterize the dust agglomeration process. The second model is based on a Monte Carlo ray-tracing code coupled to a Mie theory calculation of dust absorption and scattering parameters. These two simulation tools were used together in order to numerically predict the light transmissivity through a dusty plasma and make comparisons with experiments.

[Study on pollution characteristics of carbonaceous aerosols in Xi'an City during the spring festival].

Science.gov (United States)

Zhou, Bian-Hong; Zhang, Cheng-Zhong; Wang, Ge-Hui

2013-02-01

The samples of PM2.5 with 8 times periods were collected using Automated Cartridge Collection Unit (ACCU) of Rupprecht& Patashnick (R&P)Corporation, and monitored by R&P1400a instrument of TEOM series online during 2011 Spring Festival in Xi'an city. The organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC) and water-insoluble organic carbon (WIOC) contents of 3 h integrated PM2.5 were analyzed to evaluate the influence of firework display on the carbonaceous components in urban air. The mass concentration of PM2.5 was found increased significantly from 00:00 A. M. to 02:59 A. M. at the Chinese Lunar New Year's Eve than the non-firework periods, reaching 1514.8 microg.m-3 at 01:00 A. M. The mass concentrations of OC, EC, WSOC, and WIOC during the same time period were 123.3 microg.m-3, 18.6 microg.m-3, 66.7 microg.m-3, and 56.6 microg.m-3, about 1.7, 1.2, 1.4, and 2.2 times higher than the average in normal days, respectively. Correlation analysis among WSOC, OC, and EC contents in PM25 showed that firework emission was an obvious source of carbonaceous aerosol in the Spring Festival vacation. However, it only contributes to 9. 4% for aerosol in fireworks emission.

Geological Structure and Gold Mineralization of Carbonaceous Deposits of the Tyotechnaya Mountain (South Urals

Directory of Open Access Journals (Sweden)

A. V. Snachev

2018-03-01

Full Text Available This paper considers the geological structure of the northern part of the East-Urals Trough. Particular attention is paid to the Kosobrodskaya Formation, where the carbonaceous deposits are most abundant. It was found that the gold in the black shales of the Tyotechnaya Mountain is associated with the intensively dislocated, silicified and sulfidised rocks struck with the diorite porphyry of the Birgildin-Tomino Complex. Channel sampling on the number of wells showed the gold grades up to 1.5 g/t that allows suggesting the setting up of new gold deposit.

Laboratory Studies of the Formation of Carbonaceous Cosmic Dust from PAH Precursors

Science.gov (United States)

Salama, Farid; Contreras, C. S.

2012-05-01

The study of the formation and destruction processes of cosmic dust is essential to understand and to quantify the budget of extraterrestrial organic molecules. Although dust with all its components plays an important role in the evolution of interstellar chemistry and in the formation of organic molecules, little is known on the formation and destruction processes of carbonaceous dust. PAHs are important chemical building blocks of interstellar dust. They are detected in interplanetary dust particles and in meteoritic samples and are an important, ubiquitous component of the interstellar medium. The formation of PAHs from smaller molecules has not been extensively studied. Therefore, it is imperative that laboratory experiments be conducted to study the dynamic processes of carbon grain formation from PAH precursors. Studies of interstellar dust analogs formed from a variety of PAH and hydrocarbon precursors as well as species that include O, N, and S, have recently been performed using the COSmIC facility in our laboratory under conditions that simulate interstellar and circumstellar environments. The species formed in the pulsed discharge nozzle (PDN) plasma source are detected and characterized with high-sensitivity cavity ringdown spectroscopy coupled to a Reflectron time-of-flight mass spectrometer (ReTOF-MS), thus providing both spectroscopic and ion mass information in-situ. We report the measurements obtained in these experiments. Studies with hydrocarbon precursors show the feasibility of specific molecules to form PAHs, while studies with carbon ring systems (benzene and derivatives, PAHs) precursors provide information on pathways toward larger carbonaceous molecules. From these unique measurements, we derive information on the size and the structure of interstellar dust grain particles, the growth and the destruction processes of interstellar dust and the resulting budget of extraterrestrial organic molecules. Acknowledgements: This research is

Spatial and temporal variability of carbonaceous aerosols: Assessing the impact of biomass burning in the urban environment.

Science.gov (United States)

Titos, G; Del Águila, A; Cazorla, A; Lyamani, H; Casquero-Vera, J A; Colombi, C; Cuccia, E; Gianelle, V; Močnik, G; Alastuey, A; Olmo, F J; Alados-Arboledas, L

2017-02-01

Biomass burning (BB) is a significant source of atmospheric particles in many parts of the world. Whereas many studies have demonstrated the importance of BB emissions in central and northern Europe, especially in rural areas, its impact in urban air quality of southern European countries has been sparsely investigated. In this study, highly time resolved multi-wavelength absorption coefficients together with levoglucosan (BB tracer) mass concentrations were combined to apportion carbonaceous aerosol sources. The Aethalometer model takes advantage of the different spectral behavior of BB and fossil fuel (FF) combustion aerosols. The model was found to be more sensitive to the assumed value of the aerosol Ångström exponent (AAE) for FF (AAE ff ) than to the AAE for BB (AAE bb ). As result of various sensitivity tests the model was optimized with AAE ff =1.1 and AAE bb =2. The Aethalometer model and levoglucosan tracer estimates were in good agreement. The Aethalometer model was further applied to data from three sites in Granada urban area to evaluate the spatial variation of CM ff and CM bb (carbonaceous matter from FF or BB origin, respectively) concentrations within the city. The results showed that CM bb was lower in the city centre while it has an unexpected profound impact on the CM levels measured in the suburbs (about 40%). Analysis of BB tracers with respect to wind speed suggested that BB was dominated by sources outside the city, to the west in a rural area. Distinguishing whether it corresponds to agricultural waste burning or with biomass burning for domestic heating was not possible. This study also shows that although traffic restrictions measures contribute to reduce carbonaceous concentrations, the extent of the reduction is very local. Other sources such as BB, which can contribute to CM as much as traffic emissions, should be targeted to reduce air pollution. Copyright © 2016 Elsevier B.V. All rights reserved.

Oxygen isotopic composition of relict olivine grains in cosmic spherules: Links to chondrules from carbonaceous chondrites

Digital Repository Service at National Institute of Oceanography (India)

Rudraswami, N.G.; ShyamPrasad, M.; Nagashima, K.; Jones, R.H.

aluminium rich inclusions (CAIs), amoeboid olivine aggregates (AOAs), and some porphyritic chondrules from carbonaceous chondrites. These grains appear to have recorded the initial oxygen isotopic composition of the inner solar nebula. Three olivine... to the major components of meteorites such as chondrules and calcium-aluminium-rich inclusions (CAIs). CAIs, the first solar system objects in the solar nebula, are formed by condensation of refractory minerals at high temperatures. They are 16O...

CO2 sorption on surface-modified carbonaceous support: Probing the influence of the carbon black microporosity and surface polarity

International Nuclear Information System (INIS)

Gargiulo, Valentina; Alfè, Michela; Ammendola, Paola; Raganati, Federica; Chirone, Riccardo

2016-01-01

Graphical abstract: - Highlights: • CO 2 -sorbent materials preparation by surface modification of CB. • CB functionalization (amino-groups), CB coating (Fe 3 O 4 ), CB impregnation (ionic liquid). • Sorbents bearing basic functionalities exhibit the higher CO 2 sorption capacity. • Microporous supporting material limits the CO 2 accessibility toward the adsorbing material. - Abstract: The use of solid sorbents is a convenient option in post-combustion CO 2 capture strategies. Sorbents selection is a key point because the materials are required to be both low-cost and versatile in typical post-combustion conditions in order to guarantee an economically advantageous overall process. This work compares strategies to tailor the chemico-physical features of carbon black (CB) by surface-modification and/or coating with a CO 2 -sorbent phase. The influence of the CB microporosity, enhanced by chemical/thermal treatments, is also taken into account. Three CB surface modifications are performed and compared: (i) oxidation and functionalization with amino-groups, (ii) coating with iron oxides and (iii) impregnation with an ionic liquid (IL). The CO 2 capture performance is evaluated on the basis of the breakthrough curves measured at atmospheric pressure and room temperature in a lab-scale fixed bed micro-reactor. Most of tested solids adsorb a CO 2 amount significantly higher than a 13X zeolite and DARCO FGD (Norit) activated carbon (up to 4 times more in the best case). The sorbents bearing basic functionalities (amino-groups and IL) exhibit the highest CO 2 sorption capacity. The use of a microporous carbonaceous support limits the accessibility of CO 2 toward the adsorbing phase (IL or FM) lowering the number of accessible binding sites for CO 2 .

Lignin-based active anode materials synthesized from low-cost renewable resources

Science.gov (United States)

Rios, Orlando; Tenhaeff, Wyatt Evan; Daniel, Claus; Dudney, Nancy Johnston; Johs, Alexander; Nunnery, Grady Alexander; Baker, Frederick Stanley

2016-06-07

A method of making an anode includes the steps of providing fibers from a carbonaceous precursor, the carbon fibers having a glass transition temperature T.sub.g. In one aspect the carbonaceous precursor is lignin. The carbonaceous fibers are placed into a layered fiber mat. The fiber mat is fused by heating the fiber mat in the presence of oxygen to above the T.sub.g but no more than 20% above the T.sub.g to fuse fibers together at fiber to fiber contact points and without melting the bulk fiber mat to create a fused fiber mat through oxidative stabilization. The fused fiber mat is carbonized by heating the fused fiber mat to at least 650.degree. C. under an inert atmosphere to create a carbonized fused fiber mat. A battery anode formed from carbonaceous precursor fibers is also disclosed.

Synthesis of hydrogen-carbon clathrate material and hydrogen evolution therefrom at moderate temperatures and pressures

Science.gov (United States)

Lueking, Angela [State College, PA; Narayanan, Deepa [Redmond, WA

2011-03-08

A process for making a hydrogenated carbon material is provided which includes forming a mixture of a carbon source, particularly a carbonaceous material, and a hydrogen source. The mixture is reacted under reaction conditions such that hydrogen is generated and/or released from the hydrogen source, an amorphous diamond-like carbon is formed, and at least a portion of the generated and/or released hydrogen associates with the amorphous diamond-like carbon, thereby forming a hydrogenated carbon material. A hydrogenated carbon material including a hydrogen carbon clathrate is characterized by evolution of molecular hydrogen at room temperature at atmospheric pressure in particular embodiments of methods and compositions according to the present invention.

Seasonal variation and light absorption property of carbonaceous aerosol in a typical glacier region of the southeastern Tibetan Plateau

Science.gov (United States)

Niu, Hewen; Kang, Shichang; Wang, Hailong; Zhang, Rudong; Lu, Xixi; Qian, Yun; Paudyal, Rukumesh; Wang, Shijin; Shi, Xiaofei; Yan, Xingguo

2018-05-01

Deposition and accumulation of light-absorbing carbonaceous aerosol on glacier surfaces can alter the energy balance of glaciers. In this study, 2 years (December 2014 to December 2016) of continuous observations of carbonaceous aerosols in the glacierized region of the Mt. Yulong and Ganhaizi (GHZ) basin are analyzed. The average elemental carbon (EC) and organic carbon (OC) concentrations were 1.51±0.93 and 2.57±1.32 µg m-3, respectively. Although the annual mean OC / EC ratio was 2.45±1.96, monthly mean EC concentrations during the post-monsoon season were even higher than OC in the high altitudes (approximately 5000 m a. s. l. ) of Mt. Yulong. Strong photochemical reactions and local tourism activities were likely the main factors inducing high OC / EC ratios in the Mt. Yulong region during the monsoon season. The mean mass absorption efficiency (MAE) of EC, measured for the first time in Mt. Yulong, at 632 nm with a thermal-optical carbon analyzer using the filter-based method, was 6.82±0.73 m2 g-1, comparable with the results from other studies. Strong seasonal and spatial variations of EC MAE were largely related to the OC abundance. Source attribution analysis using a global aerosol-climate model, equipped with a black carbon (BC) source tagging technique, suggests that East Asia emissions, including local sources, have the dominant contribution (over 50 %) to annual mean near-surface BC in the Mt. Yulong area. There is also a strong seasonal variation in the regional source apportionment. South Asia has the largest contribution to near-surface BC during the pre-monsoon season, while East Asia dominates the monsoon season and post-monsoon season. Results in this study have great implications for accurately evaluating the influences of carbonaceous matter on glacial melting and water resource supply in glacierization areas.

Evaluation of traffic exhaust contributions to ambient carbonaceous submicron particulate matter in an urban roadside environment in Hong Kong

Science.gov (United States)

Lee, Berto Paul; Kwok Keung Louie, Peter; Luk, Connie; Keung Chan, Chak

2017-12-01

Road traffic has significant impacts on air quality particularly in densely urbanized and populated areas where vehicle emissions are a major local source of ambient particulate matter. Engine type (i.e., fuel use) significantly impacts the chemical characteristics of tailpipe emission, and thus the distribution of engine types in traffic impacts measured ambient concentrations. This study provides an estimation of the contribution of vehicles powered by different fuels (gasoline, diesel, LPG) to carbonaceous submicron aerosol mass (PM1) based on ambient aerosol mass spectrometer (AMS) and elemental carbon (EC) measurements and vehicle count data in an urban inner city environment in Hong Kong with the aim to gauge the importance of different engine types to particulate matter burdens in a typical urban street canyon. On an average per-vehicle basis, gasoline vehicles emitted 75 and 93 % more organics than diesel and LPG vehicles, respectively, while EC emissions from diesel vehicles were 45 % higher than those from gasoline vehicles. LPG vehicles showed no appreciable contributions to EC and thus overall represented a small contributor to traffic-related primary ambient PM1 despite their high abundance (˜ 30 %) in the traffic mix. Total carbonaceous particle mass contributions to ambient PM1 from diesel engines were only marginally higher (˜ 4 %) than those from gasoline engines, which is likely an effect of recently introduced control strategies targeted at commercial vehicles and buses. Overall, gasoline vehicles contributed 1.2 µg m-3 of EC and 1.1 µ m-3 of organics, LPG vehicles 0.6 µg m-3 of organics and diesel vehicles 2.0 µg m-3 of EC and 0.7 µg m-3 of organics to ambient carbonaceous PM1.

Process for production of liquid fuels

Energy Technology Data Exchange (ETDEWEB)

1947-03-14

The process comprises continually passing a current of carbonaceous material, finely divided in a vertical zone of reaction, finely divided carbonaceous material raised to a fluidized state dispersed in gas flowing from the bottom to the top carrying into the zone of reaction an oxidizing gas in sufficient quantity to supply the heat for combustion by burning part of the carbonaceous material withdrawing from the zone of reaction the products of the combustible fluids, withdrawing from the zone the solid carbonaceous products of the reaction and reacting a part of the lesser products left in a second zone of reaction by means of steam to produce oxides of carbon and hydrogen.

Precursor polymers for the carbon coating of Au@ZnO multipods for application as active material in lithium-ion batteries.

Science.gov (United States)

Oschmann, Bernd; Tahir, Muhammad Nawaz; Mueller, Franziska; Bresser, Dominic; Lieberwirth, Ingo; Tremel, Wolfgang; Passerini, Stefano; Zentel, Rudolf

2015-06-01

The synthesis of statistical and block copolymers based on polyacrylonitrile, as a source for carbonaceous materials, and thiol-containing repeating units as inorganic nanoparticle anchoring groups is reported. These polymers are used to coat Au@ZnO multipod heteroparticles with polymer brushes. IR spectroscopy and transmission electron microscopy prove the successful binding of the polymer onto the inorganic nanostructures. Thermogravimetric analysis is applied to compare the binding ability of the block and statistical copolymers. Subsequently, the polymer coating is transformed into a carbonaceous (partially graphitic) coating by pyrolysis. The obtained carbon coating is characterized by Raman spectroscopy and energy-dispersive X-ray (EDX) spectroscopy. The benefit of the conformal carbon coating of the Au@ZnO multipods regarding its application as lithium-ion anode material is revealed by performing galvanostatic cycling, showing a highly enhanced and stabilized electrochemical performance of the carbon-coated particles (still 831 mAh g(-1) after 150 cycles) with respect to the uncoated ones (only 353 mAh g(-1) after 10 cycles). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Activated carbon fibers and engineered forms from renewable resources

Science.gov (United States)

Baker, Frederick S

2013-02-19

A method of producing activated carbon fibers (ACFs) includes the steps of providing a natural carbonaceous precursor fiber material, blending the carbonaceous precursor material with a chemical activation agent to form chemical agent-impregnated precursor fibers, spinning the chemical agent-impregnated precursor material into fibers, and thermally treating the chemical agent-impregnated precursor fibers. The carbonaceous precursor material is both carbonized and activated to form ACFs in a single step. The method produces ACFs exclusive of a step to isolate an intermediate carbon fiber.

Polyaniline (PANi based electrode materials for energy storage and conversion

Directory of Open Access Journals (Sweden)

Huanhuan Wang

2016-09-01

Full Text Available Polyaniline (PANi as one kind of conducting polymers has been playing a great role in the energy storage and conversion devices besides carbonaceous materials and metallic compounds. Due to high specific capacitance, high flexibility and low cost, PANi has shown great potential in supercapacitor. It alone can be used in fabricating an electrode. However, the inferior stability of PANi limits its application. The combination of PANi and other active materials (carbon materials, metal compounds or other polymers can surpass these intrinsic disadvantages of PANi. This review summarizes the recent progress in PANi based composites for energy storage/conversion, like application in supercapacitors, rechargeable batteries, fuel cells and water hydrolysis. Besides, PANi derived nitrogen-doped carbon materials, which have been widely employed as carbon based electrodes/catalysts, are also involved in this review. PANi as a promising material for energy storage/conversion is deserved for intensive study and further development.

Zhamanshin astrobleme provides evidence for carbonaceous chondrite and post-impact exchange between ejecta and Earth's atmosphere.

Science.gov (United States)

Magna, Tomáš; Žák, Karel; Pack, Andreas; Moynier, Frédéric; Mougel, Bérengère; Peters, Stefan; Skála, Roman; Jonášová, Šárka; Mizera, Jiří; Řanda, Zdeněk

2017-08-09

Chemical fingerprints of impacts are usually compromised by extreme conditions in the impact plume, and the contribution of projectile matter to impactites does not often exceed a fraction of per cent. Here we use chromium and oxygen isotopes to identify the impactor and impact-plume processes for Zhamanshin astrobleme, Kazakhstan. ε 54 Cr values up to 1.54 in irghizites, part of the fallback ejecta, represent the 54 Cr-rich extremity of the Solar System range and suggest a CI-like chondrite impactor. Δ 17 O values as low as -0.22‰ in irghizites, however, are incompatible with a CI-like impactor. We suggest that the observed 17 O depletion in irghizites relative to the terrestrial range is caused by partial isotope exchange with atmospheric oxygen (Δ 17 O = -0.47‰) following material ejection. In contrast, combined Δ 17 O-ε 54 Cr data for central European tektites (distal ejecta) fall into the terrestrial range and neither impactor fingerprint nor oxygen isotope exchange with the atmosphere are indicated.Identifying the original impactor from craters remains challenging. Here, the authors use chromium and oxygen isotopes to indicate that the Zhamanshin astrobleme impactor was a carbonaceous chrondrite by demonstrating that depleted 17O values are due to exchange with atmospheric oxygen.

Synthetic carbonaceous fuel and feedstock using nuclear power, air, and water. [CO/sub 2/ from atmosphere and ocean reacting with H/sub 2/ to produce MeOH and then gasoline

Energy Technology Data Exchange (ETDEWEB)

Steinberg, M [Brookhaven National Lab., Upton, NY; Baron, S

1977-01-01

Development of synthetic carbonaceous fuels and feedstocks (SCFF) is imperative if the U.S. is to maintain its world leadership. All forms of carbonaceous materials can serve as sources of raw material for SCFF, however, here we consider the ultimate renewable resource of carbon which is CO/sub 2/ from the atmosphere or the oceans. A number of methods for the recovery of CO/sub 2/ have been examined. An absorption-stripping system utilizing dilute carbonate solvent appears most economical for atmospheric recovery while distillation appears of interest for sea-water recovery. An alternative isothermal process utilizing chlor-alkali cells is also described. Electrolytic hydrogen is thermocatalytically combined with the CO/sub 2/ to form methanol which can then be dehydrated to gasoline. Production cost is dominated by the energy for hydrogen and the plant capital investment. Base loaded nuclear power plants supplying peaking load and generating SCFF in an off-peak mode is proposed for reducing costs. Under 1974/5 conditions, incremental power costs would have been a minimum. Under 1985 escalated conditions, incremental costs indicate 6 mills/kWh(e) for power which yields 33.9 c/gallon methanol or 77.1 c/gallon of equivalent gasoline which takes credit for oxygen would break even with $23/bbl of oil. The capital investment for producing the equivalent of one million barrels/day of gasoline in 142 nuclear reactors of 100 MW(e) capacity, operating in an off-peak mode, amounts to slightly more than the investment in new oil exploration and production facilities and considerably less than the projected outflow of capital to foreign OPEC countries. The nuclear synthesis-route using atmospheric and aquatic CO/sub 2/ simulates the solar photosynthetic process and provides a long-term renewable and environmentally acceptable alternate source of SCFF.

Isotopically Anomalous Carbonaceous Nanoglobules in Meteorites and Comets

Science.gov (United States)

de Gregorio, B. T.; Alexander, C.; Bassim, N. D.; Cody, G. D.; Kilcoyne, D.; Nittler, L.; Stroud, R.; Zega, T. J.

2009-12-01

Sub-micron, spherical, organic globules are prevalent in primitive meteorites and interplanetary dust particles. Many of these globules are significantly enriched in 15N and/or D, relative to solar values, which suggest that they or their precursors formed in cold regions of the solar nebula or in interstellar molecular clouds. We have used correlated transmission electron microscopy (TEM), synchrotron-based X-ray absorption near-edge structure spectroscopy (XANES), and secondary ion mass spectrometry (SIMS) to determine the elemental and isotopic composition and organic functional group chemistry of individual carbonaceous nanoglobules in a suite of insoluble organic matter (IOM) residues prepared from carbonaceous and ordinary chondrites, and two additional organic globules from the Stardust comet 81P/Wild 2 sample collection. The majority of the meteoritic nanoglobules have a similar chemistry to the bulk IOM, with, on average, a small but significant enrichment in aromatic ketone (-C=O) and carboxyl (-COOH) functional groups. However, some of the meteoritic nanoglobules and one of the Stardust nanoglobules contain highly aromatic organic matter with no significant oxygen functionality. Preliminary measurements indicate that the highest 15N enrichments are associated with the highly aromatic nanoglobules and that aromatic nanoglobules are more prevalent in IOM from more primitive meteorites (e.g. Bells contains more aromatic globules than Murchison). For example, of two adjacent nanoglobules with nearly identical hollow morphologies from Murchison, one contains highly aromatic organic matter and the other contains oxidized IOM-like organic matter. SIMS analysis of these two globules reveals that the highly aromatic globule has the greatest 15N enrichment (δ15N ~ +500‰) of all meteoritic globules in which both XANES and SIMS was performed, whereas the adjacent IOM-like globule has a smaller 15N enrichment (δ15N ~ +300‰) but still greater than bulk IOM (δ15

The carbonaceous matter in the uraniferous dequartzified and albitized leucogranite of Saraya (Senegal): an example of superimposed hydrothermal alterations

International Nuclear Information System (INIS)

Mouthier, B.

1988-01-01

Two superimposed early hydrothermal alterations have been recognized in the Proterozoic Saraya leucogranite. Successively are described a major dequartzification leading to an episyenite infilled with carbonaceous matter and sulfate during an interruption of the system, succeeded by a mobilization of U and other elements during an albitization. A dolomite filling up followed by a silicopotassic feed-back alteration, close down the system [fr

Sources and formation mechanisms of carbonaceous aerosol at a regional background site in the Netherlands : insights from a year-long radiocarbon study

NARCIS (Netherlands)

Dusek, Ulrike; Hitzenberger, Regina; Kasper-Giebl, Anne; Kistler, Magdalena; Meijer, Harro A. J.; Szidat, Sonke; Wacker, Lukas; Holzinger, Rupert; Rockmann, Thomas

2017-01-01

We measured the radioactive carbon isotope C-14 (radiocarbon) in various fractions of the carbonaceous aerosol sampled between February 2011 and March 2012 at the Cesar Observatory in the Netherlands. Based on the radiocarbon content in total carbon (TC), organic carbon (OC), water-insoluble organic

Treating effluents; recovering coal, etc

Energy Technology Data Exchange (ETDEWEB)

Jones, F B; Bury, E

1920-02-18

Liquor obtained by scrubbing coal gas with sea-water or fresh water, and containing or having added to it finely-divided carbonaceous material in suspension, is subjected to a froth-flotation process to recover the carbonaceous matter and organic materials in the froth, and render the remaining liquor innocuous. Liquor obtained by scrubbing distillation gases, such as coal gas, may be used as a frothing-agent in a froth flotation process for the recovery of carbonaceous substances such as coal from materials containing them, thereby producing a froth containing the coal, etc., and also the organic materials from the liquor. In some cases the effluent may be diluted with sea-water, and, in recovering carbonaceous shales, there may be added to the liquor a small proportion of paraffin oil.

Reprocessing and disposal of used lubricating and process materials. requirements, problems, and solution methods

Energy Technology Data Exchange (ETDEWEB)

Matzke, U D

1978-02-01

A discussion covers West German laws concerning used oil disposal and re-refining (316,000 tons were reprocessed in 1976); disposal of sulfuric acid resins or tar and fuller's earth containing mineral oils by solidification (with added lime, alkali ash, clay, etc.) or pyrolysis; disposal of rolling mill scale and sludge containing oil and grease by rolling with a solid carbonaceous material and processing to high-grade sponge iron; and the breaking of oil-water emulsions.

Mapping Organic Materials in Carbonaceous Chondrites

Science.gov (United States)

Gasda, P. J.; Taylor, G. J.; Misra, A.; Sharma, S. K.

2012-09-01

We present two new techniques that, together, constitute a quick first order method to characterize the insoluble organic matter (IOM), shedding light on the heterogeneity of the IOM both in its composition and its distribution in meteorites.

Exploration of Carbonaceous Materials for Supercapacitors

OpenAIRE

Liu, Tianyu

2017-01-01

Energy storage techniques are critical for feasible implantation of sustainable energy, as most sustainable energy sources suffer from intermittent nature, uneven geographically distribution and unstable natural availability. Supercapacitors are a family of energy storage devices capable of storing electric energy converted from sustainable energy such as solar energy and wind energy. They distinguish from another family of energy storage devices, i.e., batteries, by their ability to be fully...

Carbonaceous Materials from End-capped Alkynes

Czech Academy of Sciences Publication Activity Database

Hlavatý, Jaromír; Kavan, Ladislav; Kubišta, Jiří

2002-01-01

Roč. 40, č. 3 (2002), s. 345-349 ISSN 0008-6223 R&D Projects: GA ČR GA203/00/0634; GA ČR GA203/99/1015 Institutional research plan: CEZ:AV0Z4040901 Keywords : carbon nanotube * alkynes * infrared spectroscopy Subject RIV: CG - Electrochemistry Impact factor: 3.048, year: 2002

Investigating the Early Carbon Cycle Using Carbonaceous Inclusions and Dissolved Carbon in Detrital Zircon

Science.gov (United States)

Bell, E. A.; Boehnke, P.; Harrison, M.; Mao, W. L.

2015-12-01

Because the terrestrial rock record extends only to ~4 Ga and older materials thus far identified are limited to detrital zircons, information about volatile abundances and cycles on early Earth is limited. Carbon, for instance, plays an important role not only in the modern biosphere but also in deep recycling of materials between the crust and mantle. We are investigating the record of carbon abundance and origin in Hadean zircons from Jack Hills (W. Australia) using two main approaches. First, carbon may partition into the zircon structure at trace levels during crystallization from a magma, and better understanding of this partitioning behavior will allow for zircon's use as a monitor of magmatic carbon contents. We have measured carbon abundances in zircon from a variety of igneous rocks (gabbro; I-, A-, and S-type granitoids) via SIMS and found that although abundances are typically low (average raw 12C/30Si ~ 1x10-6), S-type granite zircons can reach a factor of 1000 over this background. Around 10% of Hadean zircons investigated show similar enrichments, consistent with other evidence for the derivation of many Jack Hills zircons from S-type granitoids and with the establishment of modern-level carbon abundances in the crust by ca. 4.2 Ga. Diamond and graphite inclusions reported in the Jack Hills zircons by previous studies proved to be contamination by polishing debris, leaving the true abundance of these materials in the population uncertain. On a second front, we have identified and investigated primary carbonaceous inclusions in these zircons. From a population of over 10,000 Jack Hills zircons, we identified one concordant 4.10±0.01 Ga zircon that contains primary graphite inclusions (so interpreted due to their enclosure in a crack-free zircon host as shown by transmission X-ray microscopy and their crystal habit). Their δ13CPDB of -24±5‰ is consistent with a biogenic origin and, in the absence of a likely inorganic mechanism to produce such a

PIXE micro-mapping of minor elements in Hypatia, a diamond bearing carbonaceous stone from the Libyan Desert Glass area, Egypt: Inheritance from a cold molecular cloud?

International Nuclear Information System (INIS)

Andreoli, M.A.G.; Przybylowicz, W.J.; Kramers, J.; Belyanin, G.; Westraadt, J.; Bamford, M.; Mesjasz-Przybylowicz, J.; Venter, A.

2015-01-01

Matter originating from space, particularly if it represents rare meteorite samples, is ideally suited to be studied by Particle Induced X-ray Emission (PIXE) as this analytical technique covers a broad range of trace elements and is per se non-destructive. We describe and interpret a set of micro-PIXE elemental maps obtained on two minute (weighing about 25 and 150 mg), highly polished fragments taken from Hypatia, a controversial, diamond-bearing carbonaceous pebble from the SW Egyptian desert. PIXE data show that Hypatia is chemically heterogeneous, with significant amounts of primordial S, Cl, P and at least 10 elements with Z > 21 (Ti, V, Cr, Mn, Fe, Ni, Os, Ir) locally attaining concentrations above 500 ppm. Si, Al, Ca, K, O also occur, but are predominantly confined to cracks and likely represent contamination from the desert environment. Unusual in the stone is poor correlation between elements within the chalcophile (S vs. Cu, Zn) and siderophile (i.e.: Fe vs. Ni, Ir, Os) groups, whereas other siderophiles (Mn, Mo and the Platinum group elements (PGEs)) mimic the distribution of lithophile elements such as Cr and V. Worthy of mention is also the presence of a globular domain (Ø ∼ 120 μm) that is C and metals-depleted, yet Cl (P)-enriched (>3 wt.% and 0.15 wt.% respectively). While the host of the Cl remains undetermined, this chemical unit is enclosed within a broader domain that is similarly C-poor, yet Cr–Ir rich (up to 1.2 and 0.3 wt.% respectively). Our data suggest that the pebble consists of shock-compacted, primitive carbonaceous material enriched in cold, pre-solar dust.

PIXE micro-mapping of minor elements in Hypatia, a diamond bearing carbonaceous stone from the Libyan Desert Glass area, Egypt: Inheritance from a cold molecular cloud?

Energy Technology Data Exchange (ETDEWEB)

Andreoli, M.A.G., E-mail: marco.andreoli@wits.ac.za [School of Geosciences, University of the Witwatersrand, P.O. Box 3, Wits 2050 (South Africa); Przybylowicz, W.J. [iThemba LABS, National Research Foundation, P.O. Box 722, Somerset West 7129 (South Africa); AGH University of Science and Technology, Faculty of Physics & Applied Computer Science, al. A. Mickiewicza 30, 30-059 Kraków (Poland); Kramers, J.; Belyanin, G. [Department of Geology, University of Johannesburg, Auckland Park 2006 (South Africa); Westraadt, J. [Department of Physics, Nelson Mandela Metropolitan University, Port Elizabeth 6031 (South Africa); Bamford, M. [Evolutionary Studies Institute, University of the Witwatersrand, P.O. Box 3, Wits 2050 (South Africa); Mesjasz-Przybylowicz, J. [iThemba LABS, National Research Foundation, P.O. Box 722, Somerset West 7129 (South Africa); Venter, A. [South African Nuclear Energy Corporation, P.O. Box 582, Pretoria 0001 (South Africa)

2015-11-15

Matter originating from space, particularly if it represents rare meteorite samples, is ideally suited to be studied by Particle Induced X-ray Emission (PIXE) as this analytical technique covers a broad range of trace elements and is per se non-destructive. We describe and interpret a set of micro-PIXE elemental maps obtained on two minute (weighing about 25 and 150 mg), highly polished fragments taken from Hypatia, a controversial, diamond-bearing carbonaceous pebble from the SW Egyptian desert. PIXE data show that Hypatia is chemically heterogeneous, with significant amounts of primordial S, Cl, P and at least 10 elements with Z > 21 (Ti, V, Cr, Mn, Fe, Ni, Os, Ir) locally attaining concentrations above 500 ppm. Si, Al, Ca, K, O also occur, but are predominantly confined to cracks and likely represent contamination from the desert environment. Unusual in the stone is poor correlation between elements within the chalcophile (S vs. Cu, Zn) and siderophile (i.e.: Fe vs. Ni, Ir, Os) groups, whereas other siderophiles (Mn, Mo and the Platinum group elements (PGEs)) mimic the distribution of lithophile elements such as Cr and V. Worthy of mention is also the presence of a globular domain (Ø ∼ 120 μm) that is C and metals-depleted, yet Cl (P)-enriched (>3 wt.% and 0.15 wt.% respectively). While the host of the Cl remains undetermined, this chemical unit is enclosed within a broader domain that is similarly C-poor, yet Cr–Ir rich (up to 1.2 and 0.3 wt.% respectively). Our data suggest that the pebble consists of shock-compacted, primitive carbonaceous material enriched in cold, pre-solar dust.

Adsorptive removal of hydrophobic organic compounds by carbonaceous adsorbents: a comparative study of waste-polymer-based, coal-based activated carbon, and carbon nanotubes.

Science.gov (United States)

Lian, Fei; Chang, Chun; Du, Yang; Zhu, Lingyan; Xing, Baoshan; Liu, Chang

2012-01-01

Adsorption of the hydrophobic organic compounds (HOCs) trichloroethylene (TCE), 1,3-dichlorobenzene (DCB), 1,3-dinitrobenzene (DNB) and gamma-hexachlorocyclohexane (HCH) on five different carbonaceous materials was compared. The adsorbents included three polymer-based activated carbons, one coal-based activated carbon (F400) and multiwalled carbon nanotubes (MWNT). The polymer-based activated carbons were prepared using KOH activation from waste polymers: polyvinyl chloride (PVC), polyethyleneterephthalate (PET) and tire rubber (TR). Compared with F400 and MWNT, activated carbons derived from PVC and PET exhibited fast adsorption kinetics and high adsorption capacity toward the HOCs, attributed to their extremely large hydrophobic surface area (2700 m2/g) and highly mesoporous structures. Adsorption of small-sized TCE was stronger on the tire-rubber-based carbon and F400 resulting from the pore-filling effect. In contrast, due to the molecular sieving effect, their adsorption on HCH was lower. MWNT exhibited the lowest adsorption capacity toward HOCs because of its low surface area and characteristic of aggregating in aqueous solution.

Adsorptive removal of hydrophobic organic compounds by carbonaceous adsorbents: A comparative study of waste-polymer-based,coal-based activated carbon, and carbon nanotubes

Institute of Scientific and Technical Information of China (English)

Fei Lian; Chun Chang; Yang Du; Lingyan Zhu; Baoshan Xing; Chang Liu

2012-01-01

Adsorption of the hydrophobic organic compounds (HOCs) trichloroethylene (TCE),1,3-dichlorobenzene (DCB),1,3-dinitrobenzene (DNB) and γ-hexachlorocyclohexane (HCH) on five different carbonaceous materials was compared.The adsorbents included three polymer-based activated carbons,one coal-based activated carbon (F400) and multiwalled carbon nanotubes (MWNT).The polymerbased activated carbons were prepared using KOH activation from waste polymers:polyvinyl chloride (PVC),polyethyleneterephthalate (PET) and tire rubber (TR).Compared with F400 and MWNT,activated carbons derived from PVC and PET exhibited fast adsorption kinetics and high adsorption capacity toward the HOCs,attributed to their extremely large hydrophobic surface area (2700 m2/g) and highly mesoporous structures.Adsorption of small-sized TCE was stronger on the tire-rubber-based carbon and F400 resulting from the pore-filling effect.In contrast,due to the molecular sieving effect,their adsorption on HCH was lower.MWNT exhibited the lowest adsorption capacity toward HOCs because of its low surface area and characteristic of aggregating in aqueous solution.

Melanin-originated carbonaceous dots for triple negative breast cancer diagnosis by fluorescence and photoacoustic dual-mode imaging.

Science.gov (United States)

Xiao, Wei; Li, Yuan; Hu, Chuan; Huang, Yuan; He, Qin; Gao, Huile

2017-07-01

Carbonaceous dots exhibit increasing applications in diagnosis and drug delivery due to excellent photostability and biocompatibility properties. However, relative short excitation and emission of melanin carbonaceous dots (MCDs) limit the applicability in fluorescence bioimaging. Furthermore, the generally poor spatial resolution of fluorescence imaging limits potential in vivo applications. Due to a variety of beneficial properties, in this study, MCDs were prepared exhibiting great potential in fluorescence and photoacoustic dual-mode bioimaging. The MCDs exhibited a long excitation peak at 615nm and emission peak at 650nm, further highlighting the applicability in fluorescence imaging, while the absorbance peak at 633nm renders MCDs suitable for photoacoustic imaging. In vivo, the photoacoustic signal of MCDs was linearly correlated with the concentration of MCDs. Moreover, the MCDs were shown to be taken up into triple negative breast cancer cell line 4T1 in both a time- and concentration-dependent manner. In vivo fluorescence and photoacoustic imaging of subcutaneous 4T1 tumor demonstrated that MCDs could passively target triple negative breast cancer tissue by enhanced permeability and retention effects and may therefore be used for tumor dual-mode imaging. Furthermore, fluorescence distribution in tissue slices suggested that MCDs may distribute in 4T1 tumor with high efficacy. In conclusion, the MCDs studied offer potential application in fluorescence and photoacoustic dual-mode imaging. Copyright © 2017 Elsevier Inc. All rights reserved.

Seasonal variation and light absorption property of carbonaceous aerosol in a typical glacieri region of the southeastern Tibetan Plateau

Energy Technology Data Exchange (ETDEWEB)

Niu, Hewen; Kang, Shichang; Wang, Hailong; Zhang, Rudong; Lu, Xixi; Qian, Yun; Paudyal, Rukumesh; Wang, Shijin; Shi, Xiaofei; Yan, Xingguo

2018-05-07

Deposition and accumulation of light-absorbing carbonaceous aerosol on glacier surfaces can alter the energy balance of glaciers. In this study, 2 years (December 2014 to December 2016) of continuous observations of carbonaceous aerosols in the glacierized region of the Mt. Yulong and Ganhaizi (GHZ) basin are analyzed. The average elemental carbon (EC) and organic carbon (OC) concentrations were 1.51±0.93 and 2.57±1.32 µg m−3, respectively. Although the annual mean OC ∕ EC ratio was 2.45±1.96, monthly mean EC concentrations during the post-monsoon season were even higher than OC in the high altitudes (approximately 5000 m a. s. l. ) of Mt. Yulong. Strong photochemical reactions and local tourism activities were likely the main factors inducing high OC ∕ EC ratios in the Mt. Yulong region during the monsoon season. The mean mass absorption efficiency (MAE) of EC, measured for the first time in Mt. Yulong, at 632 nm with a thermal-optical carbon analyzer using the filter-based method, was 6.82±0.73 m2 g−1, comparable with the results from other studies. Strong seasonal and spatial variations of EC MAE were largely related to the OC abundance. Source attribution analysis using a global aerosol–climate model, equipped with a black carbon (BC) source tagging technique, suggests that East Asia emissions, including local sources, have the dominant contribution (over 50 %) to annual mean near-surface BC in the Mt. Yulong area. There is also a strong seasonal variation in the regional source apportionment. South Asia has the largest contribution to near-surface BC during the pre-monsoon season, while East Asia dominates the monsoon season and post-monsoon season. Results in this study have great implications for accurately evaluating the influences of carbonaceous matter on glacial melting and water resource supply in glacierization areas.

Seasonal variation and light absorption property of carbonaceous aerosol in a typical glacier region of the southeastern Tibetan Plateau

Directory of Open Access Journals (Sweden)

H. Niu

2018-05-01

Full Text Available Deposition and accumulation of light-absorbing carbonaceous aerosol on glacier surfaces can alter the energy balance of glaciers. In this study, 2 years (December 2014 to December 2016 of continuous observations of carbonaceous aerosols in the glacierized region of the Mt. Yulong and Ganhaizi (GHZ basin are analyzed. The average elemental carbon (EC and organic carbon (OC concentrations were 1.51±0.93 and 2.57±1.32 µg m−3, respectively. Although the annual mean OC ∕ EC ratio was 2.45±1.96, monthly mean EC concentrations during the post-monsoon season were even higher than OC in the high altitudes (approximately 5000 m a. s. l.  of Mt. Yulong. Strong photochemical reactions and local tourism activities were likely the main factors inducing high OC ∕ EC ratios in the Mt. Yulong region during the monsoon season. The mean mass absorption efficiency (MAE of EC, measured for the first time in Mt. Yulong, at 632 nm with a thermal-optical carbon analyzer using the filter-based method, was 6.82±0.73 m2 g−1, comparable with the results from other studies. Strong seasonal and spatial variations of EC MAE were largely related to the OC abundance. Source attribution analysis using a global aerosol–climate model, equipped with a black carbon (BC source tagging technique, suggests that East Asia emissions, including local sources, have the dominant contribution (over 50 % to annual mean near-surface BC in the Mt. Yulong area. There is also a strong seasonal variation in the regional source apportionment. South Asia has the largest contribution to near-surface BC during the pre-monsoon season, while East Asia dominates the monsoon season and post-monsoon season. Results in this study have great implications for accurately evaluating the influences of carbonaceous matter on glacial melting and water resource supply in glacierization areas.

Source apportionment of carbonaceous particulate matter during haze days in Shanghai based on the radiocarbon

International Nuclear Information System (INIS)

Nannan Wei; Jialiang Feng; Detao Xiao

2017-01-01

To estimate the sources of carbonaceous particulate matter, "1"4C and biomass-burning marker (levoglucosan) were measured in the form of organic carbon (OC) and elemental carbon (EC) in PM_2_._5 that was collected in five different functional districts of Shanghai during winter 2013. Spatial variations of the contemporary proportion among different districts were evident. The results of levoglucosan in Xujiahui (XH) and Chongming (CM) agreed well with those of "1"4C. The results indicate that environmental protection policies should vary for functional districts within the same city to account for their different sources of emissions. (author)

Annual Report (No. 2) of Center for Advanced Research of Energy Technology, Hokkaido University; Hokkaido Daigaku energy sentan kogaku kenkyu center nenpo dai 2 go

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

Compiled into this report are the activities and achievements of the center in fiscal 1995. Under study in the field of carbonaceous resources conversion reaction are the high-molecular coagulation structure, pyrolysis and carbonization, ignition, complex conversion of resources together with other resources, etc. Under study in the field of carbonaceous resources assessment are catalytic chemistry, organic chemistry, physical chemistry, and analytical chemistry. Under study in the field of the control of energy conversion are the generation of high-temperature thermal energy and its conversion into electromagnetic energy. In the study of ultimate materials engineering, materials are studied for use under hostile conditions such as in a nuclear fusion reactor. As for papers published in fiscal 1995, there are 9 in the field of carbonaceous resources conversion reaction, 11 in the field of carbonaceous resources assessment, 7 in the field of energy conversion control, 10 in the field of ultimate materials engineering, and 4 in other fields. Published also are 9 articles covering general remarks, interpretations, and reviews. As for academic lectures, 13 are given in the field of carbonaceous resources conversion reaction, 14 in the field of carbonaceous resources assessment, 27 in the field of energy conversion control, and 39 in the field of ultimate materials engineering. (NEDO)

Annual Report (No. 3) of Center for Advanced Research of Energy Technology, Hokkaido University; Hokkaido Daigaku energy sentan kogaku kenkyu center nenpo dai 3 go

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

Compiled into this report are the activities and achievements of the center in fiscal 1996. Its studies in the field of carbonaceous resources conversion reaction involve the high-molecular coagulation structure, pyrolysis and carbonization, ignition, complex conversion of resources together with other resources, etc.Under study in the field of carbonaceous resources evaluation are catalytic chemistry, organic chemistry, physical chemistry, and analytical chemistry. Under study in the field of the control of energy conversion are the generation of high-temperature thermal energy and its conversion into electromagnetic energy. In the study of ultimate materials engineering, materials are studied for use under hostile conditions such as in a nuclear fusion reactor, atomic reactor, and combustion plasma. As for papers published in fiscal 1996, there are 19 in the field of carbonaceous resources conversion reaction, 17 in the field of carbonaceous resources assessment, 6 in the field of energy conversion control, and 26 in the field of ultimate materials engineering. Published also are 8 articles covering general remarks, interpretations, and reviews. As for academic lectures, 31 are given in the field of carbonaceous resources conversion reaction, 20 in the field of carbonaceous resources assessment, 30 in the field of energy conversion control, and 38 in the field of ultimate materials engineering. (NEDO)

Annual Report (No. 4) of Center for Advanced Research of Energy Technology, Hokkaido University; Hokkaido Daigaku energy sentan kogaku kenkyu center nenpo dai 4 go

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-03-01

Compiled into this report are the activities and achievements of the center in fiscal 1997. Under study in the field of carbonaceous resources conversion reaction are the high-molecular coagulation structure, pyrolysis and carbonization, ignition, complex conversion of resources together with other resources, etc. Under study in the field of carbonaceous resources assessment are catalytic chemistry, organic chemistry, physical chemistry, and analytical chemistry. Under study in the field of the control of energy conversion are the generation of high-temperature thermal energy and its conversion into electromagnetic energy. In the study of ultimate materials engineering, materials are studied for use under hostile conditions such as in a nuclear fusion reactor. As for papers published in fiscal 1997, there are 18 in the field of carbonaceous resources conversion reaction, 10 in the field of carbonaceous resources assessment, 13 in the field of energy conversion control, and 17 in the field of ultimate materials engineering. Published also are 10 articles covering general remarks, interpretations, and reviews. As for academic lectures, 26 are given in the field of carbonaceous resources conversion reaction, 13 in the field of carbonaceous resources assessment, 29 in the field of energy conversion control, and 45 in the field of ultimate materials engineering. (NEDO)

Annual Report (No. 5) of Center for Advanced Research of Energy Technology, Hokkaido University; Hokkaido Daigaku energy sentan kogaku kenkyu center nenpo dai 5 go

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

Compiled into this report are the activities and achievements of the center in fiscal 1998. Under study in the field of carbonaceous resources conversion reaction are the high-molecular coagulation structure, pyrolysis and carbonization, ignition, complex conversion of resources together with other resources, etc. Under study in the field of carbonaceous resources assessment are catalytic chemistry, organic chemistry, physical chemistry, and analytical chemistry. Under study in the field of the control of energy conversion are the generation of high-temperature thermal energy and its conversion into electromagnetic energy. In the study of ultimate materials engineering, materials are studied for use under hostile conditions such as in a nuclear fusion reactor. As for papers published in fiscal 1998, there are 24 in the field of carbonaceous resources conversion reaction, 8 in the field of carbonaceous resources assessment, 10 in the field of energy conversion control, and 17 in the field of ultimate materials engineering. Published also are 4 articles covering general remarks, interpretations, and reviews. As for academic lectures, 21 are given in the field of carbonaceous resources conversion reaction, 25 in the field of carbonaceous resources assessment, 23 in the field of energy conversion control, and 47 in the field of ultimate materials engineering. (NEDO)

CO{sub 2} sorption on surface-modified carbonaceous support: Probing the influence of the carbon black microporosity and surface polarity

Energy Technology Data Exchange (ETDEWEB)

Gargiulo, Valentina [Istituto di Ricerche sulla Combustione (IRC)-CNR, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Alfè, Michela, E-mail: alfe@irc.cnr.it [Istituto di Ricerche sulla Combustione (IRC)-CNR, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Ammendola, Paola [Istituto di Ricerche sulla Combustione (IRC)-CNR, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Raganati, Federica [Università degli Studi di Napoli “Federico II”, Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Chirone, Riccardo [Istituto di Ricerche sulla Combustione (IRC)-CNR, Piazzale V. Tecchio 80, 80125 Napoli (Italy)

2016-01-01

Graphical abstract: - Highlights: • CO{sub 2}-sorbent materials preparation by surface modification of CB. • CB functionalization (amino-groups), CB coating (Fe{sub 3}O{sub 4}), CB impregnation (ionic liquid). • Sorbents bearing basic functionalities exhibit the higher CO{sub 2} sorption capacity. • Microporous supporting material limits the CO{sub 2} accessibility toward the adsorbing material. - Abstract: The use of solid sorbents is a convenient option in post-combustion CO{sub 2} capture strategies. Sorbents selection is a key point because the materials are required to be both low-cost and versatile in typical post-combustion conditions in order to guarantee an economically advantageous overall process. This work compares strategies to tailor the chemico-physical features of carbon black (CB) by surface-modification and/or coating with a CO{sub 2}-sorbent phase. The influence of the CB microporosity, enhanced by chemical/thermal treatments, is also taken into account. Three CB surface modifications are performed and compared: (i) oxidation and functionalization with amino-groups, (ii) coating with iron oxides and (iii) impregnation with an ionic liquid (IL). The CO{sub 2} capture performance is evaluated on the basis of the breakthrough curves measured at atmospheric pressure and room temperature in a lab-scale fixed bed micro-reactor. Most of tested solids adsorb a CO{sub 2} amount significantly higher than a 13X zeolite and DARCO FGD (Norit) activated carbon (up to 4 times more in the best case). The sorbents bearing basic functionalities (amino-groups and IL) exhibit the highest CO{sub 2} sorption capacity. The use of a microporous carbonaceous support limits the accessibility of CO{sub 2} toward the adsorbing phase (IL or FM) lowering the number of accessible binding sites for CO{sub 2}.

Characterization of carbonaceous materials in PM2.5 and PM10 size fractions in Morogoro, Tanzania, during 2006 wet season campaign

International Nuclear Information System (INIS)

Mkoma, Stelyus L.; Chi Xuguang; Maenhaut, Willy

2010-01-01

Atmospheric aerosol samples in PM10 and PM2.5 size fractions were collected in parallel at a rural site in Morogoro during wet season in March and April 2006. All samples were analysed for the particulate matter mass, for organic, elemental, and total carbon (OC, EC, and TC), and for water-soluble OC (WSOC). The average PM10 and PM2.5 mass concentrations and associated standard deviations were 14 ± 13 μg/m 3 and 7.3 ± 4 μg/m 3 respectively. On average, TC accounted for 33% of the PM10 mass and 44% of the PM2.5 mass for the campaign. The average OC/PM percentage ratios were 27% and 33% in PM10 and PM2.5 size fractions respectively and a larger fraction of the OC was water-soluble. The observed low EC/TC mean percentage ratios of 10-14% respectively for PM10 and PM2.5 fractions indicate that the carbonaceous aerosol originates mainly from biogenic aerosols and/or biomass burning. A simple source apportionment approach was used to apportion the OC to biofuel and charcoal burning. On average, 93% of the PM10 OC was attributed to biofuel and 7% to charcoal burning in the 2006 wet season campaign. However, it is suggested that a contribution to the OC at Morogoro could also come from other natural biogenic matter, and/or biomass burning aerosols. The results for the sources of OC at Morogoro should therefore be considered with great caution.

Estimation of gas-particle partitioning coefficients (Kp) of carcinogenic polycyclic aromatic hydrocarbons in carbonaceous aerosols collected at Chiang-Mai, Bangkok and Hat-Yai, Thailand.

Science.gov (United States)

Pongpiachan, Siwatt; Ho, Kin Fai; Cao, Junji

2013-01-01

To assess environmental contamination with carcinogens, carbonaceous compounds, water-soluble ionic species and trace gaseous species were identified and quantified every three hours for three days at three different atmospheric layers at the heart of Chiang-Mai, Bangkok and Hat-Yai from December 2006 to February 2007. A DRI Model 2001 Thermal/Optical Carbon Analyzer with the IMPROVE thermal/optical reflectance (TOR) protocol was used to quantify the organic carbon (OC) and elemental carbon (EC) contents in PM10. Diurnal and vertical variability was also carefully investigated. In general, OC and EC mass concentration showed the highest values at the monitoring period of 21.00-00.00 as consequences of human activities at night bazaar coupled with reduction of mixing layer, decreased wind speed and termination of photolysis at nighttime. Morning peaks of carbonaceous compounds were observed during the sampling period of 06:00-09:00, emphasizing the main contribution of traffic emission in the three cities. The estimation of incremental lifetime particulate matter exposure (ILPE) raises concern of high risk of carbonaceous accumulation over workers and residents living close to the observatory sites. The average values of incremental lifetime particulate matter exposure (ILPE) of total carbon at Baiyoke Suit Hotel and Baiyoke Sky Hotel are approximately ten times higher than those air samples collected at Prince of Songkla University Hat-Yai campus corpse incinerator and fish-can manufacturing factory but only slightly higher than those of rice straw burning in Songkla province. This indicates a high risk of developing lung cancer and other respiratory diseases across workers and residents living in high buildings located in Pratunam area. Using knowledge of carbonaceous fractions in PM10, one can estimate the gas-particle partitioning of polycyclic aromatic hydrocarbons (PAHs). Dachs-Eisenreich model highlights the crucial role of adsorption in gas

Relationship between indoor and outdoor carbonaceous particulates in roadside households

Energy Technology Data Exchange (ETDEWEB)

Funasaka, K.; Miyazaki, T.; Tsuruho, K. [Osaka City Institute of Public Health and Environmental Sciences (Japan); Tamura, K. [The National Institute for Minamata Disease, Kumamoto (Japan); Mizuno, T. [Mie University (Japan). Dept. of Chemistry for Materials; Kuroda, K. [Osaka City University Medical School (Japan). Dept. of Preventive Medicine and Environmental Health

2000-07-01

Concentrations of particulate matter (PM) and carbonaceous particulates in indoor and outdoor air at roadside private households were measured in Osaka, Japan. The particulate samples were collected on filters using a portable AND sampler capable of separating particles into three different size ranges: over 10 {mu}m, 2-10 {mu}m (coarse) and below 2 {mu}m (fine) in aerodynamic diameter. The filters were weighed and then analyzed for elemental carbon (EC) and organic carbon (OC) by thermal oxidation using a CHN CORDER. The results showed that indoor fine PM concentration is considerably affected by fine EC and the fine EC in indoor air is significantly correlated to that in outdoor air, r = 0.86 (n = 30, p < 0.001). A simple estimation from EC content ratio in diesel exhaust particles indicated that about 30% of indoor particulates of less than 10 {mu}m (PM10) were contributed from diesel exhaust. Additionally, the size characteristics of outdoor PM at roadside and background sites were examined using Andersen Cascade Impactors. (author)

Carbowaste: treatment and disposal of irradiated graphite and other carbonaceous waste

International Nuclear Information System (INIS)

Von Lensa, W.; Rizzato, C.; Baginski, K.; Banford, A.W.; Bradbury, D.; Goodwin, J.; Grambow, B.; Grave, M.J.; Jones, A.N.; Laurent, G.; Pina, G.; Vulpius, D.

2014-01-01

The European Project on 'Treatment and Disposal of Irradiated Graphite and other Carbonaceous Waste (CARBOWASTE)' addressed the retrieval, characterization, treatment, reuse and disposal of irradiated graphite with the following main results: - I-graphite waste features significantly depend on the specific manufacture process, on the operational conditions in the nuclear reactor (neutron dose, atmosphere, temperature etc.) and on radiolytic oxidation leading to partial releases of activation products and precursors during operation. - The neutron activation process generates significant recoil energies breaking pre-existing chemical bonds resulting in dislocations of activation products and new chemical compounds. - Most activation products exist in different chemical forms and at different locations. - I-graphite can be partly purified by thermal and chemical treatment processes leaving more leach-resistant waste products. - Leach tests and preliminary performance analyses show that i-graphite can be safely disposed of in a wide range of disposal systems, after appropriate treatment and/or conditioning. (authors)

Possible superlattice formation in high-temperature treated carbonaceous MgB2 at elevated pressure

International Nuclear Information System (INIS)

Tschauner, Oliver; Errandonea, Daniel; Serghiou, George

2006-01-01

We report indications of a phase transition in carbonaceous MgB 2 above 9 GPa at 300 K after stress relaxation by laser heating. The transition was detected using Raman spectroscopy and X-ray diffraction. The observed changes are consistent with a second-order structural transition involving a doubling of the unit cell along c and a reduction of the boron site symmetry. Moreover, the Raman spectra suggest a reduction in electron-phonon coupling in the slightly modified MgB 2 structure consistent with the previously proposed topological transition in MgB 2 . However, further attributes including deviatoric stress, lattice defects, and compositional variation may play an important role in the observed phenomena

Carbonaceous Chondrite Meteorites: the Chronicle of a Potential Evolutionary Path between Stars and Life.

Science.gov (United States)

Pizzarello, Sandra; Shock, Everett

2017-09-01

The biogenic elements, H, C, N, O, P and S, have a long cosmic history, whose evolution can still be observed in diverse locales of the known universe, from interstellar clouds of gas and dust, to pre-stellar cores, nebulas, protoplanetary discs, planets and planetesimals. The best analytical window into this cosmochemical evolution as it neared Earth has been provided so far by the small bodies of the Solar System, some of which were not significantly altered by the high gravitational pressures and temperatures that accompanied the formation of larger planets and may carry a pristine record of early nebular chemistry. Asteroids have delivered such records, as their fragments reach the Earth frequently and become available for laboratory analyses. The Carbonaceous Chondrite meteorites (CC) are a group of such fragments with the further distinction of containing abundant organic materials with structures as diverse as kerogen-like macromolecules and simpler compounds with identical counterparts in Earth's biosphere. All have revealed a lineage to cosmochemical synthetic regimes. Several CC show that asteroids underwent aqueous alteration of their minerals or rock metamorphism but may yet yield clues to the reactivity of organic compounds during parent-body processes, on asteroids as well as larger ocean worlds and planets. Whether the exogenous delivery by meteorites held an advantage in Earth's molecular evolution remains an open question as many others regarding the origins of life are. Nonetheless, the natural samples of meteorites allow exploring the physical and chemical processes that might have led to a selected chemical pool amenable to the onset of life. Graphical Abstract ᅟ.

Carbonaceous species emitted from handheld two-stroke engines

Science.gov (United States)

Volckens, John; Olson, David A.; Hays, Michael D.

Small, handheld two-stroke engines used for lawn and garden work (e.g., string trimmers, leaf blowers, etc.) can emit a variety of potentially toxic carbonaceous air pollutants. Yet, the emissions effluents from these machines go largely uncharacterized, constraining the proper development of human exposure estimates, emissions inventories, and climate and air quality models. This study samples and evaluates chemical pollutant emissions from the dynamometer testing of six small, handheld spark-ignition engines—model years 1998-2002. Four oil-gas blends were tested in each engine in duplicate. Emissions of carbon dioxide, carbon monoxide, and gas-phase hydrocarbons were predominant, and the PM emitted was organic matter primarily. An ANOVA model determined that engine type and control tier contributed significantly to emissions variations across all identified compound classes; whereas fuel blend was an insignificant variable accounting for engines were generally intermediate in magnitude compared with other gasoline-powered engines, numerous compounds traditionally viewed as motor vehicle markers are also present in small engine emissions in similar relative proportions. Given that small, handheld two-stroke engines used for lawn and garden work account for 5-10% of total US emissions of CO, CO 2, NO x, HC, and PM 2.5, source apportionment models and human exposure studies need to consider the effect of these small engines on ambient concentrations in air polluted environments.

Detection and formation scenario of citric acid, pyruvic acid, and other possible metabolism precursors in carbonaceous meteorites

Science.gov (United States)

Cooper, George; Reed, Chris; Nguyen, Dang; Carter, Malika; Wang, Yi

2011-01-01

Carbonaceous meteorites deliver a variety of organic compounds to Earth that may have played a role in the origin and/or evolution of biochemical pathways. Some apparently ancient and critical metabolic processes require several compounds, some of which are relatively labile such as keto acids. Therefore, a prebiotic setting for any such individual process would have required either a continuous distant source for the entire suite of intact precursor molecules and/or an energetic and compact local synthesis, particularly of the more fragile members. To date, compounds such as pyruvic acid, oxaloacetic acid, citric acid, isocitric acid, and α-ketoglutaric acid (all members of the citric acid cycle) have not been identified in extraterrestrial sources or, as a group, as part of a “one pot” suite of compounds synthesized under plausibly prebiotic conditions. We have identified these compounds and others in carbonaceous meteorites and/or as low temperature (laboratory) reaction products of pyruvic acid. In meteorites, we observe many as part of three newly reported classes of compounds: keto acids (pyruvic acid and homologs), hydroxy tricarboxylic acids (citric acid and homologs), and tricarboxylic acids. Laboratory syntheses using 13C-labeled reactants demonstrate that one compound alone, pyruvic acid, can produce several (nonenzymatic) members of the citric acid cycle including oxaloacetic acid. The isotopic composition of some of the meteoritic keto acids points to interstellar or presolar origins, indicating that such compounds might also exist in other planetary systems. PMID:21825143

Synchrotron Radiation XRD Analysis of Indialite in Y-82094 Ungrouped Carbonaceous Chondrite

Science.gov (United States)

Mikouchi, T.; Hagiya, K.; Sawa, N.; Kimura, M.; Ohsumi, K.; Komatsu, M.; Zolensky, M.

2016-01-01

Y-82094 is an ungrouped type 3.2 carbonaceous chondrite, with abundant chondrules making 78 vol.% of the rock. Among these chondrules, an unusual porphyritic Al-rich magnesian chondrule is reported that consists of a cordierite-like phase, Al-rich orthopyroxene, cristobalite, and spinel surrounded by an anorthitic mesostasis. The reported chemical formula of the cordierite-like phase is Na(0.19)Mg(1.95)Fe(0.02)Al(3.66)Si(5.19)O18, which is close to stoichiometric cordierite (Mg2Al3[AlSi5O18]). Although cordierite can be present in Al-rich chondrules, it has a high temperature polymorph (indialite) and it is therefore necessary to determine whether it is cordierite or indialite in order to better constrain its formation conditions. In this abstract we report on our synchrotron radiation X-ray diffraction (SR-XRD) study of the cordierite-like phase in Y-82094.

Pyrolytic carbon black composite and method of making the same

Energy Technology Data Exchange (ETDEWEB)

Naskar, Amit K.; Paranthaman, Mariappan Parans; Bi, Zhonghe

2016-09-13

A method of recovering carbon black includes the step of providing a carbonaceous source material containing carbon black. The carbonaceous source material is contacted with a sulfonation bath to produce a sulfonated material. The sulfonated material is pyrolyzed to produce a carbon black containing product comprising a glassy carbon matrix phase having carbon black dispersed therein. A method of making a battery electrode is also disclosed.

Molecular and isotope constraints on the formation of the insoluble organic matter of carbonaceous meteorites

Science.gov (United States)

Derenne, Sylvie; Robert, François

2017-04-01

The origin of the insoluble organic matter (IOM) of the carbonaceous meteorites remains an unsolved issue despite major achievements in the knowledge of its chemical structure. The latter led us to propose a model for its molecular structure. Based on the relationship between the aromatic moieties of the macromolecular structure and their aliphatic linkages, it was recently suggested that, its synthesis has taken place in the gas phase of the disk surrounding the Sun in its early T-Tauri phase and that organic radicals have played a central role in this organo-synthesis. To test experimentally this pathway, we submitted short hydrocarbons (methane, pentane, octane) to a microwave plasma discharge so as to produce in situ CHx radicals. The black organic residue deposited contained both soluble and insoluble OM. The comparison at the molecular level between the thus synthesized IOM and that of meteorite led to strong similarities thus supporting the proposed pathway for its organo-synthesis. Moreover, in the meteorite IOM, systematic deuterium enrichment relative to the protosolar value is observed at the bulk sample scale and micrometer-sized grains exhibit dramatic enrichments in deuterium interpreted as a heritage of the interstellar medium or resulting from ion-molecule reactions taking place in the diffuse part of the solar disk. In the aforementioned synthesized IOM, NanoSIMS analyses revealed large variations at a sub-micrometric spatial resolution. They likely reflect the differences in the D/H ratios of the CHx radicals whose polymerization is at the origin of the IOM. These isotopic heterogeneities are commensurable with those observed in meteorite IOM. As a consequence, the appearance of organic radicals in the ionized regions of the T-Tauri solar disk may have triggered the formation of organic compounds. This laboratory synthesis thus shed a new light on the formation conditions and pathways of the IOM of carbonaceous chondrites.

A Combined Study Investigating the Insoluble and Soluble Organic Compounds in Category 3 Carbonaceous Itokawa Particles Recovered by the Hayabusa Mission

Science.gov (United States)

Chan, Q. H. S.; Zolensky, M.; Burton, A.; Clemett, S.; Fries, M.; Kebukawa, Y.

2015-01-01

At the 3rd International Announcement of Opportunity (AO), we have been approved for five Category 3 carbonaceous Itokawa particles (RA-QD02-0012, RA-QD02-0078, RB-CV-0029, RB-CV-0080 and RB-QD04-0052) recovered by the first Hayabusa mission of JAXA. In this investigation, we aim to provide a comprehensive study to characterize and account for the presence of carbon-bearing phases as suggested by the initial Scanning Electron Microscopy (SEM) analysis carried out by JAXA at the curation facility, and to describe the mineralogical components of the particles. The insoluble organic content of Itokawa particle has been investigated with the use of micro-Raman spectroscopy by Kitajima and co-workers [1]. The Raman spectra of Itokawa particles show broad G- and D-bands typical of low temperature material which offers an interesting contrast to the high metamorphic grade (LL4-6) of the Itokawa parent body. Amino acid analysis has been conducted by Naraoka et al. [2] to study the soluble organic component of Itokawa particles, but since it was a preliminary study and thus did not have the opportunity to target on Category 3 carbonaceous particles, only terrestrial contaminants were identified. The investigation will be carried out in the following order prioritized according to the progressive damage the analytical techniques can induce: (1) micro-Raman spectrometry, (2) two-step laser mass spectrometry (micro-L2MS), (3) ultra-high performance liquid chromatography with fluorescence detection and time-of-flight mass spectrometry (LC-FD/ToF-MS), and optimally if we can recover the particles after wet chemistry analysis, we will mount the samples and perform (4) electron beam microscopy (SEM, electron back-scattered diffraction [EBSD]) and (5) carbon X-ray absorption near edge structure spectroscopy (C-XANES). We will begin the analytical procedures upon receiving the samples in September/October. This work will provide us with an understanding of the variety and origins of

Adsorption of aromatic compounds by carbonaceous adsorbents: a comparative study on granular activated carbon, activated carbon fiber, and carbon nanotubes.

Science.gov (United States)

Zhang, Shujuan; Shao, Ting; Kose, H Selcen; Karanfil, Tanju

2010-08-15

Adsorption of three aromatic organic compounds (AOCs) by four types of carbonaceous adsorbents [a granular activated carbon (HD4000), an activated carbon fiber (ACF10), two single-walled carbon nanotubes (SWNT, SWNT-HT), and a multiwalled carbon nanotube (MWNT)] with different structural characteristics but similar surface polarities was examined in aqueous solutions. Isotherm results demonstrated the importance of molecular sieving and micropore effects in the adsorption of AOCs by carbonaceous porous adsorbents. In the absence of the molecular sieving effect, a linear relationship was found between the adsorption capacities of AOCs and the surface areas of adsorbents, independent of the type of adsorbent. On the other hand, the pore volume occupancies of the adsorbents followed the order of ACF10 > HD4000 > SWNT > MWNT, indicating that the availability of adsorption site was related to the pore size distributions of the adsorbents. ACF10 and HD4000 with higher microporous volumes exhibited higher adsorption affinities to low molecular weight AOCs than SWNT and MWNT with higher mesopore and macropore volumes. Due to their larger pore sizes, SWNTs and MWNTs are expected to be more efficient in adsorption of large size molecules. Removal of surface oxygen-containing functional groups from the SWNT enhanced adsorption of AOCs.

Seasonal variations and sources of ambient fossil and biogenic-derived carbonaceous aerosols based on 14C measurements in Lhasa, Tibet

Science.gov (United States)

Huang, Jie; Kang, Shichang; Shen, Chengde; Cong, Zhiyuan; Liu, Kexin; Wang, Wei; Liu, Lichao

2010-06-01

A total of 30 samples of total suspended particles were collected at an urban site in Lhasa, Tibet from August 2006 to July 2007 for investigating carbonaceous aerosol features. The fractions of contemporary carbon ( fc) in total carbon (TC) of ambient aerosols are presented using radiocarbon ( 14C) measurements. The value of fc represents the biogenic contribution to TC, as the biosphere releases organic compounds with the present 14C/ 12C level ( fc = 1), whereas 14C has become extinct in anthropogenic emissions of fossil carbon ( fc = 0). The fc values in Lhasa ranging from 0.357 to 0.702, are higher than Beijing and Tokyo, but clearly lower than the rural region of Launceston, which indicates a major biogenic influence in Lhasa. Seasonal variations of fc values corresponded well with variations of pollutants concentrations (e.g. NO 2). Higher fc values appeared in winter indicating carbonaceous aerosol is more dominated by wood burning and incineration of agricultural wastes within this season. The lower fc values in summer and autumn may be caused by increased diesel and petroleum emissions related to tourism in Lhasa. δ13C values ranged from - 26.40‰ to - 25.10‰, with relative higher values in spring and summer, reflecting the increment of fossil carbon emissions.

Nature of the "Orange" Material on Vesta From Dawn

Science.gov (United States)

LeCorre, L.; Reddy, V.; Schmedemann, N.; Becker, K. J.; OBrien, D. P.; Yamashita, N.; Peplowski, P. N.; Prettyman, T. H.; Li, J.-Y.; Coultis, E. A.;

Metastable carbon in two chondritic porous interplanetary dust particles

International Nuclear Information System (INIS)

Rietmeijer, F.J.M.; Mackinnon, I.D.R.

1986-01-01

An understanding of carbonaceous matter in primitive extraterrestrial materials is an essential component of studies on dust evolution in the interstellar medium and the early history of the Solar System. Analytical Electron Microscopy (AEM) on carbonaceous material in two Chondritic Porous (CP) aggregrates is presented. The study suggests that a record of hydrocarbon carbonization may also be preserved in these materials

Molecular and compound-specific hydrogen isotope analyses of insoluble organic matter from different carbonaceous chondrite groups

Science.gov (United States)

Wang, Yi; Huang, Yongsong; Alexander, Conel M. O.'D.; Fogel, Marilyn; Cody, George

2005-07-01

We have conducted the first systematic analyses of molecular distribution and δD values of individual compounds in pyrolysates of insoluble organic matter (IOM) from different carbonaceous chondrite groups, using flash pyrolysis coupled to gas chromatography-mass spectrometry and compound-specific D/H analysis. IOM samples from six meteorites of different classifications, Elephant Moraine (EET) 92042 (CR2), Orgueil (CI1), Allan Hills (ALH) 83100 (CM1/2), Murchison (CM2), ALH 85013 (CM2), and Tagish Lake (C2) were isolated and studied. Except for the pyrolysate of Tagish Lake IOM, pyrolysates of all five meteorite IOM samples were dominated by an extensive series of aromatic (C 1 to C 7 alkyl-substituted benzenes, C 0 to C 2 alkyl-substituted naphthalenes), with aliphatic (straight chain and branched C 10 to C 15 alkanes) hydrocarbons and several S- and O- containing compounds (C 1 to C 2 alkylthiophenes, benzothiophene, benzaldehyde) being also present. The strong similarity in the pyrolysates of different carbonaceous chondrites suggests certain common characteristics in the formation mechanisms of IOM from different meteorites. The Tagish Lake IOM sample is unique in that its pyrolysate lacks most of the alkyl-substituted aromatic hydrocarbons detected in other meteorite IOM samples, suggesting distinctively different formation processes. Both bulk δD values of meteorite IOMs and weighted-average δD values of individual compounds in pyrolysates show a decreasing trend: CR2 > CI1 > CM2 > C2 (Tagish Lake), with the EET 92042 (CR2) IOM having the highest δD values (˜2000‰ higher than other samples). We attribute the high D contents in the IOM to primitive interstellar organic sources.

Characterization of emissions from South Asian biofuels and application to source apportionment of carbonaceous aerosol in the Himalayas

Science.gov (United States)

Stone, Elizabeth A.; Schauer, James J.; Pradhan, Bidya Banmali; Dangol, Pradeep Man; Habib, Gazala; Venkataraman, Chandra; Ramanathan, V.

2010-03-01

This study focuses on improving source apportionment of carbonaceous aerosol in South Asia and consists of three parts: (1) development of novel molecular marker-based profiles for real-world biofuel combustion, (2) application of these profiles to a year-long data set, and (3) evaluation of profiles by an in-depth sensitivity analysis. Emissions profiles for biomass fuels were developed through source testing of a residential stove commonly used in South Asia. Wood fuels were combusted at high and low rates, which corresponded to source profiles high in organic carbon (OC) or high in elemental carbon (EC), respectively. Crop wastes common to the region, including rice straw, mustard stalk, jute stalk, soybean stalk, and animal residue burnings, were also characterized. Biofuel profiles were used in a source apportionment study of OC and EC in Godavari, Nepal. This site is located in the foothills of the Himalayas and was selected for its well-mixed and regionally impacted air masses. At Godavari, daily samples of fine particulate matter (PM2.5) were collected throughout the year of 2006, and the annual trends in particulate mass, OC, and EC followed the occurrence of a regional haze in South Asia. Maximum concentrations occurred during the dry winter season and minimum concentrations occurred during the summer monsoon season. Specific organic compounds unique to aerosol sources, molecular markers, were measured in monthly composite samples. These markers implicated motor vehicles, coal combustion, biomass burning, cow dung burning, vegetative detritus, and secondary organic aerosol as sources of carbonaceous aerosol. A molecular marker-based chemical mass balance (CMB) model provided a quantitative assessment of primary source contributions to carbonaceous aerosol. The new profiles were compared to widely used biomass burning profiles from the literature in a sensitivity analysis. This analysis indicated a high degree of stability in estimates of source

Evaluation of the growth of carbonaceous deposit in steady state Tore Supra using infrared thermography

International Nuclear Information System (INIS)

Mitteau, R.; Guilhem, D.; Reichle, R.; Vallet, J.C.; Roche, H.; Buravand, Y.; Chantant, M.; Tsitrone, E.; Brosset, C.; Grosman, A.; Chappuis, P.

2006-01-01

Fusion devices with carbon as the main armour material are experiencing a growth in carbonaceous deposits at the surface of the plasma facing components. Tore Supra presents such deposits, and has specific features which influence their growth: long pulse operation and cooled walls. Deposits have a low thermal transfer to the cooled structure so that they appear as hot areas with the infrared imaging system looking at the elements surface temperature during plasma discharges. A 'degree of (carbon) deposit' on the toroidal pumped limiter is estimated by establishing the ratio between the apparent power on the limiter derived from the infrared measure and the actual one, deduced from a power balance analysis between the injected and the radiated power. This criterion is used to monitor the evolution of the deposit average thermal resistance. Successive shots have a similar 'degree of deposit', showing that the evaluation makes sense. Two years of data have been compiled (2003 and 2004), representing 3000 discharges (13 h of plasma, including 30 discharges longer than one minute). A three-fold increase in the 'degree of deposit' over six months is evidenced, following a limiter clean-up early in 2003. A comparison with calorimetric data produces a similar result, albeit less pronounced. Large steps in the degree of deposit are sometimes observed, usually correlated with identified events such as disruption, vessel opening, conditioning or plasma parameters change. It indicates that the deposit thermal resistance can change rapidly, although a systematic correlation with the above mentioned events could not be established

Evaluation of the growth of carbonaceous deposit in steady state Tore Supra using infrared thermography

Science.gov (United States)

Mitteau, R.; Guilhem, D.; Reichle, R.; Vallet, J. C.; Roche, H.; Buravand, Y.; Chantant, M.; Tsitrone, E.; Brosset, C.; Grosman, A.; Chappuis, P.

2006-03-01

Fusion devices with carbon as the main armour material are experiencing a growth in carbonaceous deposits at the surface of the plasma facing components. Tore Supra presents such deposits, and has specific features which influence their growth: long pulse operation and cooled walls. Deposits have a low thermal transfer to the cooled structure so that they appear as hot areas with the infrared imaging system looking at the elements surface temperature during plasma discharges. A 'degree of (carbon) deposit' on the toroidal pumped limiter is estimated by establishing the ratio between the apparent power on the limiter derived from the infrared measure and the actual one, deduced from a power balance analysis between the injected and the radiated power. This criterion is used to monitor the evolution of the deposit average thermal resistance. Successive shots have a similar 'degree of deposit', showing that the evaluation makes sense. Two years of data have been compiled (2003 and 2004), representing 3000 discharges (13 h of plasma, including 30 discharges longer than one minute). A three-fold increase in the 'degree of deposit' over six months is evidenced, following a limiter clean-up early in 2003. A comparison with calorimetric data produces a similar result, albeit less pronounced. Large steps in the degree of deposit are sometimes observed, usually correlated with identified events such as disruption, vessel opening, conditioning or plasma parameters change. It indicates that the deposit thermal resistance can change rapidly, although a systematic correlation with the above mentioned events could not be established.

Effects of secondary alteration on the composition of free and IOM-derived monocarboxylic acids in carbonaceous chondrites

Science.gov (United States)

Aponte, José C.; Alexandre, Marcelo R.; Wang, Yi; Brearley, Adrian J.; Alexander, Conel M. O.'D.; Huang, Yongsong

2011-05-01

Monocarboxylic acids (MCAs) are important astrobiologically because they are often the most abundant soluble compounds in carbonaceous chondrites (CCs) and are potential synthetic end products for many biologically important compounds. However, there has been no systematic study on the effect of parent body alteration on molecular and isotopic variability of MCAs. Since MCAs in meteorites are dominated by low molecular weight (C1-C8), highly volatile compounds, their distributions are likely to be particularly sensitive to secondary alteration processes. In contrast, the aliphatic side chains of insoluble organic matter (IOM) in CCs, whose composition has been shown to be closely related to the MCAs, may be far more resistant to secondary alteration. In the present study, we determined the distributions and isotopic ratios of free and IOM-derived MCAs in six carbonaceous chondrites with a range of classifications: Murchison (CM2), EET 87770 (CR2), ALH 83034 (CM1), ALH 83033 (CM2), MET 00430 (CV3) and WIS 91600 (C2). We compare mineralogical and petrological characteristics to the MCAs distributions to better define the processes leading to the synthesis and alteration of meteoritic MCAs. Our results show that aqueous and especially thermal alteration in the parent bodies led to major loss of free MCAs and depletion of straight relative to branched chain compounds. However, the MCAs derived from aliphatic side chains of IOM are well preserved despite of secondary alterations. The molecular and isotopic similarities of IOM-derived MCAs in different chondrite samples indicate very similar synthetic histories for organic matter in different meteorites.

Correlated Amino Acid and Mineralogical Analyses of Milligram and Submilligram Samples of Carbonaceous Chondrite Lonewolf Nunataks 94101

Science.gov (United States)

Burton, S.; Berger, E. L.; Locke, D. R.; Lewis, E. K.

2018-01-01

Amino acids, the building blocks of proteins, have been found to be indigenous in the eight carbonaceous chondrite groups. The abundances, structural, enantiomeric and isotopic compositions of amino acids differ significantly among meteorites of different groups and petrologic types. These results suggest parent-body conditions (thermal or aqueous alteration), mineralogy, and the preservation of amino acids are linked. Previously, elucidating specific relationships between amino acids and mineralogy was not possible because the samples analyzed for amino acids were much larger than the scale at which petrologic heterogeneity is observed (sub mm-scale differences corresponding to sub-mg samples); for example, Pizzarello and coworkers measured amino acid abundances and performed X-ray diffraction (XRD) on several samples of the Murchison meteorite, but these analyses were performed on bulk samples that were 500 mg or larger. Advances in the sensitivity of amino acid measurements by liquid chromatography with fluorescence detection/time-of-flight mass spectrometry (LC-FD/TOF-MS), and application of techniques such as high resolution X-ray diffraction (HR-XRD) and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) for mineralogical characterizations have now enabled coordinated analyses on the scale at which mineral heterogeneity is observed. In this work, we have analyzed samples of the Lonewolf Nunataks (LON) 94101 CM2 carbonaceous chondrite. We are investigating the link(s) between parent body processes, mineralogical context, and amino acid compositions in meteorites on bulk samples (approx. 20mg) and mineral separates (< or = 3mg) from several of spatial locations within our allocated samples. Preliminary results of these analyses are presented here.

Optimizing Carbonaceous Nanostructure Composition as a Substrate to Grow Co Electrocatalysts

Directory of Open Access Journals (Sweden)

M Pourreza

2018-02-01

Full Text Available Global warming and other adverse environmental effects of fossil fuels have forced humans to consider clean and renewable energy resources. In this context, hydrogen production from water splitting reaction is a key approach. In order to reduce required overpotential for water oxidation reaction, it is necessary to use low cost and earth abundant electrocatalysts like Co, Cu, Fe, Mn, Ni and Zn nanostructures. Herein, cobalt nanostructures on steel-mesh substrate were applied. Electrochemical method was used for growth of Co nanoflakes because of its simplicity and scalability for commercial approach. On the other hand, using carbonaceous support layers including nanomaterials such as graphene and carbon nanotubes, can reduce overpotential and increase efficiency of the electrocatalyst.  According to the results, 40 wt% of graphene oxide and 60 wt% of carbon nanotubes in prepared carbon paste led to better growth for cobalt oxide nanoflakes. For the mentioned layer, cobalt was detected in metallic crystalline phase and the overpotential and electrical resistance measured 305 mV and 20 Ω, respectively.

Carbonaceous PM(2.5) and secondary organic aerosol across the Veneto region (NE Italy).

Science.gov (United States)

Khan, Md Badiuzzaman; Masiol, Mauro; Formenton, Gianni; Di Gilio, Alessia; de Gennaro, Gianluigi; Agostinelli, Claudio; Pavoni, Bruno

2016-01-15

Organic and elemental carbon (OC-EC) were measured in 360 PM2.5 samples collected from April 2012 to February 2013 at six provinces in the Veneto region, to determine the factors affecting the carbonaceous aerosol variations. The 60 daily samples have been collected simultaneously in all sites during 10 consecutive days for 6 months (April, June, August, October, December and February). OC ranged from 0.98 to 22.34 μg/m(3), while the mean value was 5.5 μg/m(3), contributing 79% of total carbon. EC concentrations fluctuated from 0.19 to 11.90 μg/m(3) with an annual mean value of 1.31 μg/m(3) (19% of the total carbon). The monthly OC concentration gradually increased from April to December. The EC did not vary in accordance with OC. However the highest values for both parameters were recorded in the cold period. The mean OC/EC ratio is 4.54, which is higher than the values observed in most of the other European cities. The secondary organic carbon (SOC) contributed for 69% of the total OC and this was confirmed by both the approaches OC/EC minimum ratio and regression. The results show that OC, EC and SOC exhibited higher concentration during winter months in all measurement sites, suggesting that the stable atmosphere and lower mixing play important role for the accumulation of air pollutant and hasten the condensation or adsorption of volatile organic compounds over the Veneto region. Significant meteorological factors controlling OC and EC were investigated by fitting linear models and using a robust procedure based on weighted likelihood, suggesting that low wind speed and temperature favour accumulation of emissions from local sources. Conditional probability function and conditional bivariate probability function plots indicate that both biomass burning and vehicular traffic are probably the main local sources for carbonaceous particulate matter emissions in two selected cities. Copyright © 2015 Elsevier B.V. All rights reserved.

Advanced source apportionment of carbonaceous aerosols by coupling offline AMS and radiocarbon size-segregated measurements over a nearly 2-year period

OpenAIRE

Vlachou, Athanasia; Daellenbach, Kaspar R.; Bozzetti, Carlo; Chazeau, Benjamin; Salazar Quintero, Gary Abdiel; Szidat, Sönke; Jaffrezo, Jean-Luc; Hueglin, Christoph; Baltensperger, Urs; Haddad, Imad El; Prévôt, André S. H.

2018-01-01

Carbonaceous aerosols are related to adverse human health effects. Therefore, identification of their sources and analysis of their chemical composition is important. The offline AMS (aerosol mass spectrometer) technique offers quantitative separation of organic aerosol (OA) factors which can be related to major OA sources, either primary or secondary. While primary OA can be more clearly separated into sources, secondary (SOA) source apportionment is more challenging because different source...

Advanced source apportionment of carbonaceous aerosols by coupling offline AMS and radiocarbon size-segregated measurements over a nearly 2-year period

OpenAIRE

A. Vlachou; K. R. Daellenbach; C. Bozzetti; B. Chazeau; G. A. Salazar; S. Szidat; J.-L. Jaffrezo; C. Hueglin; U. Baltensperger; I. E. Haddad; A. S. H. Prévôt

2018-01-01

Carbonaceous aerosols are related to adverse human health effects. Therefore, identification of their sources and analysis of their chemical composition is important. The offline AMS (aerosol mass spectrometer) technique offers quantitative separation of organic aerosol (OA) factors which can be related to major OA sources, either primary or secondary. While primary OA can be more clearly separated into sources, secondary (SOA) source apportionment is more challenging because d...

Mineralogy, petrology and geochemistry of carbonaceous chondritic clasts in the LEW 85300 polymict eucrite

Science.gov (United States)

Zolensky, M. E.; Hewins, R. H.; Mittlefehldt, D. W.; Lindstrom, M. M.; Xiao, X.; Lipschutz, M. E.

1992-01-01

We have performed a detailed petrologic and mineralogic study of two chondritic clasts from the polymict eucrite Lewis Cliff (LEW) 85300, and performed chemical analyses by INAA and RNAA on one of these. Petrologically, the clasts are identified and are composed of dispersed aggregates, chondrules, and chondrule fragments supported by matrix. The aggregates and chondrules are composed of olivine, orthopyroxene, plus some diopside. The matrix consists of fine-grained olivine, and lesser orthopyroxene and augite. Fine-grained saponite is common in the matrix. The bulk major composition of the clast studied by INAA and RNAA shows unusual abundance patterns for lithophile, siderophile and chalcophile elements but is basically chondritic. The INAA/RNAA data preclude assignment of the LEW 85300,15 clast to any commonly accepted group of carbonaceous chondrite.

Importance of Micropore-Mesopore Interfaces in Carbon Dioxide Capture by Carbon-Based Materials.

Science.gov (United States)

Durá, Gema; Budarin, Vitaliy L; Castro-Osma, José A; Shuttleworth, Peter S; Quek, Sophie C Z; Clark, James H; North, Michael

2016-08-01

Mesoporous carbonaceous materials (Starbons®) derived from low-value/waste bio-resources separate CO2 from CO2 /N2 mixtures. Compared to Norit activated charcoal (AC), Starbons® have much lower microporosities (8-32 % versus 73 %) yet adsorb up to 65 % more CO2 . The presence of interconnected micropores and mesopores is responsible for the enhanced CO2 adsorption. The Starbons® also showed three-four times higher selectivity for CO2 adsorption rather than N2 adsorption compared to AC. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Diversity in C-Xanes Spectra Obtained from Carbonaceous Solid Inclusions from Monahans Halite

Science.gov (United States)

Kebukawa, Y.; Zolensky, M. E.; Fries, M.; Kilcoyne, A. L. D.; Rahman, Z.; Cody, G. D.

2014-01-01

Monahans meteorite (H5) contains fluid inclusion- bearing halite (NaCl) crystals [1]. Microthermometry and Raman spectroscopy showed that the fluid in the inclusions is an aqueous brine and they were trapped near 25degC [1]. Their continued presence in the halite grains requires that their incorporation into the H chondrite asteroid was post metamorphism [2]. Abundant solid inclusions are also present in the halites. The solid inclusions include abundant and widely variable organics [2]. Analyses by Raman microprobe, SEM/EDX, synchrotron X-ray diffraction and TEM reveal that these grains include macromolecular carbon similar in structure to CV3 chondrite matrix carbon, aliphatic carbon compounds, olivine (Fo99-59), high- and low-Ca pyroxene, feldspars, magnetite, sulfides, lepidocrocite, carbonates, diamond, apatite and possibly the zeolite phillipsite [3]. Here we report organic analyses of these carbonaceous residues in Monahans halite using C-, N-, and O- X-ray absorption near edge structure (XANES). Samples and Methods: Approximately 100 nm-thick sections were extracted with a focused ion beam (FIB) at JSC from solid inclusions from Monahans halite. The sections were analyzed using the scanning transmission X-ray microscope (STXM) on beamline 5.3.2.2 at the Advanced Light Source, Lawrence Berkeley National Laboratory for XANES spectroscopy. Results and Discussion: C-XANES spectra of the solid inclusions show micrometer-scale heterogeneity, indicating that the macromolecular carbon in the inclusions have complex chemical variations. C-XANES features include 284.7 eV assigned to aromatic C=C, 288.4-288.8 eV assigned to carboxyl, and 290.6 eV assigned to carbonate. The carbonyl features obtained by CXANES might have been caused by the FIB used in sample preparation. No specific N-XANES features are observed. The CXANES spectra obtained from several areas in the FIB sections include type 1&2 chondritic IOM like, type 3 chondritic IOM like, and none of the above

Time-resolved measurements of PM2.5 carbonaceous aerosols at Gosan, Korea.

Science.gov (United States)

Batmunkh, T; Kim, Y J; Lee, K Y; Cayetano, M G; Jung, J S; Kim, S Y; Kim, K C; Lee, S J; Kim, J S; Chang, L S; An, J Y

2011-11-01

In order to better understand the characteristics of atmospheric carbonaceous aerosol at a background site in Northeast Asia, semicontinuous organic carbon (OC) and elemental carbon (EC), and time-resolved water-soluble organic carbon (WSOC) were measured by a Sunset OC/ EC and a PILS-TOC (particle-into-liquid sampler coupled with an online total organic carbon) analyzer, respectively, at the Gosan supersite on Jeju Island, Korea, in the summer (May 28-June 17) and fall (August 24-September 30) of 2009. Hourly average OC concentration varied in the range of approximately 0.87-28.38 microgC m-3, with a mean of 4.07+/- 2.60 microgC m-3, while the hourly average EC concentration ranged approximately from 0.04 to 8.19 .microgC m-3, with a mean of 1.35 +/- 0.71 microgC m-3, from May 28 to June 17, 2009. During the fall season, OC varied in the approximate range 0.9-9.6 microgC m-3, with a mean of 2.30 +/-0.80 microgC m-3, whereas EC ranged approximately from 0.01 to 5.40 microgC m-3, with a mean of 0.66 +/- 0.38 microgC m-3. Average contributions of EC to TC and WSOC to OC were 26.0% +/- 9.7% and 20.6% +/-7.4%, and 37.6% +/- 23.5% and 57.2% +/- 22.2% during summer and fall seasons, respectively. As expected, clear diurnal variation of WSOC/OC was found in summer, varying from 0.22 during the nighttime up to 0.72 during the daytime, mainly due to the photo-oxidation process. In order to investigate the effect of air mass pathway on the characteristics of carbonaceous aerosol, 5-day back-trajectory analysis was conducted using the HYSPLIT model. The air mass pathways were classified into four types: Continental (CC), Marine (M), East Sea (ES) and Korean Peninsula (KP). The highest OC/EC ratio of 3.63 was observed when air mass originated from the Continental area (CC). The lowest OC/EC ratio of 0.79 was measured when air mass originated from the Marine area (M). A high OC concentration was occasionally observed at Gosan due to local biomass burning activities. The

Cement production from coal conversion residues

International Nuclear Information System (INIS)

Brown, L.D.; Clavenna, L.R.; Eakman, J.M.; Nahas, N.C.

1981-01-01

Cement is produced by feeding residue solids containing carbonaceous material and ash constituents obtained from converting a carbonaceous feed material into liquids and/or gases into a cement-making zone and burning the carbon in the residue solids to supply at least a portion of the energy required to convert the solids into cement

Materials Design and System Construction for Conventional and New-Concept Supercapacitors.

Science.gov (United States)

Wu, Zhong; Li, Lin; Yan, Jun-Min; Zhang, Xin-Bo

2017-06-01

With the development of renewable energy and electrified transportation, electrochemical energy storage will be more urgent in the future. Supercapacitors have received extensive attention due to their high power density, fast charge and discharge rates, and long-term cycling stability. During past five years, supercapacitors have been boomed benefited from the development of nanostructured materials synthesis and the promoted innovation of devices construction. In this review, we have summarized the current state-of-the-art development on the fabrication of high-performance supercapacitors. From the electrode material perspective, a variety of materials have been explored for advanced electrode materials with smart material-design strategies such as carbonaceous materials, metal compounds and conducting polymers. Proper nanostructures are engineered to provide sufficient electroactive sites and enhance the kinetics of ion and electron transport. Besides, new-concept supercapacitors have been developed for practical application. Microsupercapacitors and fiber supercapacitors have been explored for portable and compact electronic devices. Subsequently, we have introduced Li-/Na-ion supercapacitors composed of battery-type electrodes and capacitor-type electrode. Integrated energy devices are also explored by incorporating supercapacitors with energy conversion systems for sustainable energy storage. In brief, this review provides a comprehensive summary of recent progress on electrode materials design and burgeoning devices constructions for high-performance supercapacitors.

Chemical Bonding and Structural Information of Black CarbonReference Materials and Individual Carbonaceous AtmosphericAerosols

Energy Technology Data Exchange (ETDEWEB)

Hopkins, Rebecca J.; Tivanski, Alexei V.; Marten, Bryan D.; Gilles, Mary K.

2007-04-25

The carbon-to-oxygen ratios and graphitic nature of a rangeof black carbon standard reference materials (BC SRMs), high molecularmass humic-like substances (HULIS) and atmospheric particles are examinedusing scanning transmission X-ray microscopy (STXM) coupled with nearedge X-ray absorption fine structure (NEXAFS) spectroscopy. UsingSTXM/NEXAFS, individual particles with diameter>100 nm are studied,thus the diversity of atmospheric particles collected during a variety offield missions is assessed. Applying a semi-quantitative peak fittingmethod to the NEXAFS spectra enables a comparison of BC SRMs and HULIS toparticles originating from anthropogenic combustion and biomass burns,thus allowing determination of the suitability of these materials forrepresenting atmospheric particles. Anthropogenic combustion and biomassburn particles can be distinguished from one another using both chemicalbonding and structural ordering information. While anthropogeniccombustion particles are characterized by a high proportion ofaromatic-C, the presence of benzoquinone and are highly structurallyordered, biomass burn particles exhibit lower structural ordering, asmaller proportion of aromatic-C and contain a much higher proportion ofoxygenated functional groups.

[Estimation of carbonaceous gases emission from forest fires in Xiao Xing'an Mountains of Northeast China in 1953-2011].

Science.gov (United States)

Hu, Hai-Qing; Luo, Bi-Zhen; Wei, Shu-Jing; Sun, Long; Wei, Shu-Wei; Wen, Zheng-Min

2013-11-01

Based on the forest resources investigation data and the forest fire inventory in 1953-2011, in combining with our field research in burned areas and our laboratory experiments, this paper estimated the carbonaceous gases carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), and nonmethane hydrocarbons (NMHC) emission from the forest fires in Xiao Xing' an Mountains of Heilongjiang Province, Northeast China in 1953-2011. The total carbon emission from the forest fires in the Xiao Xing'an Mountains in 1953-2011 was 1.12 x 10(7) t, and the annual emission was averagely 1.90 x10(5) t, accounting for 1.7% of the annual average total carbon emission from the forest fires in China. The emission of CO2, CO, CH4, and NMHC was 3.39 x 10(7), 1.94 x 10(5), 1.09 x 10(5), and 7.46 x 10(4) t, respectively, and the corresponding annual average emission was 5.74 x 10(5), 3.29 x 10(4), 1.85 x 10(3), and 1.27 x 10(3) t, accounting for 1.4%, 1.2%, 1.7%, and 1.1% of the annual carbonaceous gases emitted from the forest fires in China, respectively. The combustion efficiency and the carbon emission per unit burned area of different forest types decreased in order of coniferous forest > broad-leaved forest > coniferous broadleaved mixed forest. Some rational forest fire management measures were put forward.

Variation of mineralogy and organic material during the early stages of aqueous activity recorded in Antarctic micrometeorites

Science.gov (United States)

Noguchi, T.; Yabuta, H.; Itoh, S.; Sakamoto, N.; Mitsunari, T.; Okubo, A.; Okazaki, R.; Nakamura, T.; Tachibana, S.; Terada, K.; Ebihara, M.; Imae, N.; Kimura, M.; Nagahara, H.

2017-07-01

Micrometeorites (MMs) recovered from surface snow near the Dome Fuji Station, Antarctica are almost free from terrestrial weathering and contain very primitive materials, and are suitable for investigation of the evolution and interaction of inorganic and organic materials in the early solar system. We carried out a comprehensive study on seven porous and fluffy MMs [four Chondritic porous (CP) MMs and three fluffy fine-grained (Fluffy Fg) MMs] and one fine-grained type 1 (Fg C1) MM for comparison with scanning electron microscope, transmission electron microscope, X-ray absorption near-edge structure analysis, and secondary ion mass spectrometer. They show a variety of early aqueous activities. Four out of the seven CP MMs contain glass with embedded metal and sulfide (GEMS) and enstatite whiskers/platelets and do not have hydrated minerals. Despite the same mineralogy, organic chemistry of the CP MMs shows diversity. Two of them contain considerable amounts of organic materials with high carboxyl functionality, and one of them contains nitrile (Ctbnd N) and/or nitrogen heterocyclic groups with D and 15N enrichments, suggesting formation in the molecular cloud or a very low temperature region of the outer solar system. Another two CP MMs are poorer in organic materials than the above-mentioned MMs. Organic material in one of them is richer in aromatic C than the CP MMs mentioned above, being indistinguishable from those of hydrated carbonaceous chondrites. In addition, bulk chemical compositions of GEMS in the latter organic poor CP MMs are more homogeneous and have higher Fe/(Si + Mg + Fe) ratios than those of GEMS in the former organic-rich CP MMs. Functional group of the organic materials and amorphous silicate in GEMS in the organic-poor CP MMs may have transformed in the earliest stage of aqueous alteration, which did not form hydrated minerals. Three Fluffy Fg MMs contain abundant phyllosilicates, showing a clear evidence of aqueous alteration

Laboratory study of carbonaceous dust and molecules of astrochemical interest

International Nuclear Information System (INIS)

Cataldo, F; Garcia-Hernandez, D A; Manchado, A; Kwok, S

2016-01-01

In this paper are reviewed some research works dedicated to the study of carbonaceous dust and molecules of astrochemical interest. First of all it is discussed the carbon arc through which it is possible to produce carbon soot and fullerenes under helium but also many other different products just changing the arcing conditions. For example, when the carbon arc is struck in an hydrocarbon solvent it is possible to produce and trap polyynes in the solvent. Monocyanopolyynes and dicyanopolyynes can be produced as well by selecting the appropriate conditions. Amorphous carbon soot or partially graphitized carbon black can be produced with the carbon arc. Fullerenes were found in space thanks to the reference infrared spectra and the absorption cross sections which were determined in laboratory. Fullerenes are readily reactive with hydrogen yielding fulleranes the hydrogenated fullerenes. Furthermore fullerenes react with PAHs and with iron carbonyl yielding adducts. All these fullerene derivatives were synthesized and their reference spectra recorded in laboratory. It was proposed that petroleum fractions can be used as model substrates in the explanation of the carriers of the AIB (Aromatic Infrared Bands) observed in protoplanetary and planetary nebulae and the UIE (Unidentified Infrared Bands) found in the interstellar medium. (paper)

The anthropogenic influence on carbonaceous aerosol in the European background

Energy Technology Data Exchange (ETDEWEB)

May, Barbara; Wagenbach, Dietmar; Hammer, Samuel (Institut fuer Umweltphysik, Univ. Heidelberg (Germany)). e-mail: barbara.may@iup.uni-heidelberg.de; Steier, Peter (VERA laboratory, Univ. of Vienna (Austria)); Puxbaum, Hans (Inst. for Chemical Technologies and Analytics, Vienna Univ. of Technology, Vienna (Austria)); Pio, Casimiro (CESAM and Dept. of Environment, Univ. of Aveiro (Portugal))

2009-07-01

To constrain the relatively uncertain anthropogenic impact on the organic aerosol load, radiocarbon analyses were performed on aerosol samples, collected year-round, at six non-urban sites including a maritime background and three remote mountain stations, lying on a west-east transect over Western Europe. From a crude three component model supported by TOC and levoglucosan filter data, the fossil fuel, biomass burning and biogenic TOC fraction are estimated, showing at all stations year-round, a relatively constant fossil fuel fraction of around (26 +- 6)%, a dominant biogenic contribution of on average (73 +- 7)% in summer and the continental as well as the maritime background TOC to be only about 50% biogenic. Assuming biomass burning as completely anthropogenic, the carbonaceous aerosol concentration at the mountain sites was found to have increased by a factor of up to (1.4 +- 0.2) in summer and up to (2.5 +- 1.0) in winter. This figure is significantly lower, however, than the respective TOC change since pre-industrial times seen in an Alpine ice core. Reconciling both observations would require an increase, since pre-industrial times, of the background biogenic aerosol load, which is estimated at a factor of 1.3-1.7.

The anthropogenic influence on carbonaceous aerosol in the European background

Energy Technology Data Exchange (ETDEWEB)

May, Barbara; Wagenbach, Dietmar; Hammer, Samuel (Inst. fuer Umweltphysik, Univ. Heidelberg (Germany)). e-mail: barbara.may@iup.uni-heidelberg.de; Steier, Peter (VERA laboratory, Univ. of Vienna (Austria)); Puxbaum, Hans (Inst. for Chemical Technologies and Analytics, Vienna Univ. of Technology (Austria)); Pio, Casimiro (CESAM and Dept. of Environment, Univ. of Aveiro (Portugal))

2008-07-01

To constrain the relatively uncertain anthropogenic impact on the organic aerosol load, radiocarbon analyses were performed on aerosol samples, collected year-round, at six non-urban sites including a maritime background and three remote mountain stations, lying on a west-east transect over Western Europe. From a crude three component model supported by TOC and levoglucosan filter data, the fossil fuel, biomass burning and biogenic TOC fraction are estimated, showing at all stations year-round, a relatively constant fossil fuel fraction of around (26 +- 6)% , a dominant biogenic contribution of on average (73 +- 7)% in summer and the continental as well as the maritime background TOC to be only about 50% biogenic. Assuming biomass burning as completely anthropogenic, the carbonaceous aerosol concentration at the mountain sites was found to have increased by a factor of up to (1.4 +- 0.2) in summer and up to (2.5 +- 1.0) in winter. This figure is significantly lower, however, than the respective TOC change since pre-industrial times seen in an Alpine ice core. Reconciling both observations would require an increase, since pre-industrial times, of the background biogenic aerosol load, which is estimated at a factor of 1.3-1.7

The Effect of Carbonaceous Reductant Selection on Chromite Pre-reduction

Science.gov (United States)

Kleynhans, E. L. J.; Beukes, J. P.; Van Zyl, P. G.; Bunt, J. R.; Nkosi, N. S. B.; Venter, M.

2017-04-01

Ferrochrome (FeCr) production is an energy-intensive process. Currently, the pelletized chromite pre-reduction process, also referred to as solid-state reduction of chromite, is most likely the FeCr production process with the lowest specific electricity consumption, i.e., MWh/t FeCr produced. In this study, the effects of carbonaceous reductant selection on chromite pre-reduction and cured pellet strength were investigated. Multiple linear regression analysis was employed to evaluate the effect of reductant characteristics on the aforementioned two parameters. This yielded mathematical solutions that can be used by FeCr producers to select reductants more optimally in future. Additionally, the results indicated that hydrogen (H)- (24 pct) and volatile content (45.8 pct) were the most significant contributors for predicting variance in pre-reduction and compressive strength, respectively. The role of H within this context is postulated to be linked to the ability of a reductant to release H that can induce reduction. Therefore, contrary to the current operational selection criteria, the authors believe that thermally untreated reductants ( e.g., anthracite, as opposed to coke or char), with volatile contents close to the currently applied specification (to ensure pellet strength), would be optimal, since it would maximize H content that would enhance pre-reduction.

Synthesis of nitrogen-doped porous carbon nanofibers as an efficient electrode material for supercapacitors.

Science.gov (United States)

Chen, Li-Feng; Zhang, Xu-Dong; Liang, Hai-Wei; Kong, Mingguang; Guan, Qing-Fang; Chen, Ping; Wu, Zhen-Yu; Yu, Shu-Hong

2012-08-28

Supercapacitors (also known as ultracapacitors) are considered to be the most promising approach to meet the pressing requirements of energy storage. Supercapacitive electrode materials, which are closely related to the high-efficiency storage of energy, have provoked more interest. Herein, we present a high-capacity supercapacitor material based on the nitrogen-doped porous carbon nanofibers synthesized by carbonization of macroscopic-scale carbonaceous nanofibers (CNFs) coated with polypyrrole (CNFs@polypyrrole) at an appropriate temperature. The composite nanofibers exhibit a reversible specific capacitance of 202.0 F g(-1) at the current density of 1.0 A g(-1) in 6.0 mol L(-1) aqueous KOH electrolyte, meanwhile maintaining a high-class capacitance retention capability and a maximum power density of 89.57 kW kg(-1). This kind of nitrogen-doped carbon nanofiber represents an alternative promising candidate for an efficient electrode material for supercapacitors.

Measurements of non-volatile aerosols with a VTDMA and their correlations with carbonaceous aerosols in Guangzhou, China

Directory of Open Access Journals (Sweden)

H. H. Y. Cheung

2016-07-01

Full Text Available Simultaneous measurements of aerosol volatility and carbonaceous matters were conducted at a suburban site in Guangzhou, China, in February and March 2014 using a volatility tandem differential mobility analyzer (VTDMA and an organic carbon/elemental carbon (OC ∕ EC analyzer. Low volatility (LV particles, with a volatility shrink factor (VSF at 300 °C exceeding 0.9, contributed 5 % of number concentrations of the 40 nm particles and 11–15 % of the 80–300 nm particles. They were composed of non-volatile material externally mixed with volatile material, and therefore did not evaporate significantly at 300 °C. Non-volatile material mixed internally with the volatile material was referred to as medium volatility (MV, 0.4  <  VSF  <  0.9 and high volatility (HV, VSF  <  0.4 particles. The MV and HV particles contributed 57–71 % of number concentration for the particles between 40 and 300 nm in size. The average EC and OC concentrations measured by the OC ∕ EC analyzer were 3.4 ± 3.0 and 9.0 ± 6.0 µg m−3, respectively. Non-volatile OC evaporating at 475 °C or above, together with EC, contributed 67 % of the total carbon mass. In spite of the daily maximum and minimum, the diurnal variations in the volume fractions of the volatile material, HV, MV and LV residuals were less than 15 % for the 80–300 nm particles. Back trajectory analysis also suggests that over 90 % of the air masses influencing the sampling site were well aged as they were transported at low altitudes (below 1500 m for over 40 h before arrival. Further comparison with the diurnal variations in the mass fractions of EC and the non-volatile OC in PM2.5 suggests that the non-volatile residuals may be related to both EC and non-volatile OC in the afternoon, during which the concentration of aged organics increased. A closure analysis of the total mass of LV and MV residuals and the mass of EC or the

Use of 15N in nitrification inhibitor studies with special reference to indigenous materials

International Nuclear Information System (INIS)

Sahrawat, K.L.

1988-01-01

Non-edible oil seed cakes and their constituents have been advantageously used for increasing the efficiency of fertilizer nitrogen (N) for crop production. The beneficial effects of these materials have been attributed to retardation of nitrification, which lessen the loss of N associated with nitrification by leaching and denitrification in situations where these losses are high. However, it is possible that some of the effects of these materials could be due to immobilization-remineralization of N particularly when the carbonaceous materials are added with fertilizers at high rates. A methodology involving the use of 15 N-labelled fertilizers is advanced to sort out whether the beneficial effects of non-edible oil seed cakes and other materials are due to retardation of nitrification and or immobilization-remineralization of fertilizer N. Using the proposed technique it would be possible to make realistic evaluation of the wealth of indigenous products as nitrification inhibitors. Following the proposed approach it would also be possible to widen the scope and depth of research in this area for ultimately better exploitation of indigenous materials as nitrification inhibitors. (author). 18 refs

Energy use and carbon footprints differ dramatically for diverse wastewater-derived carbonaceous substrates: An integrated exploration of biokinetics and life-cycle assessment.

Science.gov (United States)

Li, Yanbo; Wang, Xu; Butler, David; Liu, Junxin; Qu, Jiuhui

2017-03-21

Energy neutrality and reduction of carbon emissions are significant challenges to the enhanced sustainability of wastewater treatment plants (WWTPs). Harvesting energy from wastewater carbonaceous substrates can offset energy demands and enable net power generation; yet, there is limited research about how carbonaceous substrates influence energy and carbon implications of WWTPs with integrated energy recovery at systems-level. Consequently, this research uses biokinetics modelling and life cycle assessment philology to explore this notion, by tracing and assessing the quantitative flows of energy embodied or captured, and by exploring the carbon footprint throughout an energy-intensive activated sludge process with integrated energy recovery facilities. The results indicate that energy use and carbon footprint per cubic meter of wastewater treated, varies markedly with the carbon substrate. Compared with systems driven with proteins, carbohydrates or other short-chain fatty acids, systems fed with acetic acid realized energy neutrality with maximal net gain of power from methane combustion (0.198 kWh) and incineration of residual biosolids (0.153 kWh); and also achieved a negative carbon footprint (72.6 g CO 2 ). The findings from this work help us to better understand and develop new technical schemes for improving the energy efficiency of WWTPs by repurposing the stream of carbon substrates across systems.

Materials Design and System Construction for Conventional and New‐Concept Supercapacitors

Science.gov (United States)

Wu, Zhong; Li, Lin

2017-01-01

With the development of renewable energy and electrified transportation, electrochemical energy storage will be more urgent in the future. Supercapacitors have received extensive attention due to their high power density, fast charge and discharge rates, and long‐term cycling stability. During past five years, supercapacitors have been boomed benefited from the development of nanostructured materials synthesis and the promoted innovation of devices construction. In this review, we have summarized the current state‐of‐the‐art development on the fabrication of high‐performance supercapacitors. From the electrode material perspective, a variety of materials have been explored for advanced electrode materials with smart material‐design strategies such as carbonaceous materials, metal compounds and conducting polymers. Proper nanostructures are engineered to provide sufficient electroactive sites and enhance the kinetics of ion and electron transport. Besides, new‐concept supercapacitors have been developed for practical application. Microsupercapacitors and fiber supercapacitors have been explored for portable and compact electronic devices. Subsequently, we have introduced Li‐/Na‐ion supercapacitors composed of battery‐type electrodes and capacitor‐type electrode. Integrated energy devices are also explored by incorporating supercapacitors with energy conversion systems for sustainable energy storage. In brief, this review provides a comprehensive summary of recent progress on electrode materials design and burgeoning devices constructions for high‐performance supercapacitors. PMID:28638780

Comparative evaluation for the sorption capacity of four carbonaceous sorbents to phenol

Directory of Open Access Journals (Sweden)

Ding Feng Jin

2016-10-01

Full Text Available Sorption kinetics and isotherms of phenol by four carbonaceous sorbents (activated carbon (AC, mesoporous carbon (MPC, bamboo biochar (BBC and oak wood biochar (OBC were compared in this study. MPC has the fastest sorption rate and initial sorption potential, which were indicated by sorption rate constants and initial sorption rate “h” in a pseudo-second-order kinetic model. The ordered and straight pore structure of MPC facilitated the accessibility of phenol. The AC showed the greatest sorption capacity towards phenol with maximum sorption of 123 mg/g as calculated by the Langmuir model. High surface area, complexity of pore structure, and the strong binding force of the π–π electron-donor-acceptor interaction between phenol molecules and AC were the main mechanisms. The BBC and OBC had much slower sorption and lower sorption capacity (33.04 and 29.86 mg/g, respectively, compared to MPC (73.00 mg/g and AC, indicating an ineffective potential for phenol removal from water.

Assessment of carbonaceous aerosols in Shanghai, China - Part 1: long-term evolution, seasonal variations, and meteorological effects

Science.gov (United States)

Chang, Yunhua; Deng, Congrui; Cao, Fang; Cao, Chang; Zou, Zhong; Liu, Shoudong; Lee, Xuhui; Li, Jun; Zhang, Gan; Zhang, Yanlin

2017-08-01

Carbonaceous aerosols are major chemical components of fine particulate matter (PM2. 5) with major impacts on air quality, climate change, and human health. Gateway to fast-rising China and home of over twenty million people, Shanghai throbs as the nation's largest mega city and the biggest industrial hub. From July 2010 to December 2014, hourly mass concentrations of ambient organic carbon (OC) and elemental carbon (EC) in the PM2. 5 fraction were quasi-continuously measured in Shanghai's urban center. The annual OC and EC concentrations (mean ±1σ) in 2013 (8.9 ± 6.2 and 2.6 ± 2.1 µg m-3, n = 5547) and 2014 (7.8 ± 4.6 and 2.1 ± 1.6 µg m-3, n = 6914) were higher than those of 2011 (6.3 ± 4.2 and 2.4 ± 1.8 µg m-3, n = 8039) and 2012 (5.7 ± 3.8 and 2.0 ± 1.6 µg m-3, n = 4459). We integrated the results from historical field measurements (1999-2012) and satellite observations (2003-2013), concluding that carbonaceous aerosol pollution in Shanghai has gradually reduced since 2006. In terms of monthly variations, average OC and EC concentrations ranged from 4.0 to 15.5 and from 1.4 to 4.7 µg m-3, accounting for 13.2-24.6 and 3.9-6.6 % of the seasonal PM2. 5 mass (38.8-94.1 µg m-3), respectively. The concentrations of EC (2.4, 2.0, 2.2, and 3.0 µg m-3 in spring, summer, fall, and winter, respectively) showed little seasonal variation (except in winter) and weekend-weekday dependence, indicating EC is a relatively stable constituent of PM2. 5 in the Shanghai urban atmosphere. In contrast to OC (7.3, 6.8, 6.7, and 8.1 µg m-3 in spring, summer, fall, and winter, respectively), EC showed marked diurnal cycles and correlated strongly with CO across all seasons, confirming vehicular emissions as the dominant source of EC at the targeted site. Our data also reveal that both OC and EC showed concentration gradients as a function of wind direction (WD) and wind speed (WS), generally with higher values associated with winds from the southwest, west, and northwest

Engineering Bacteria to Catabolize the Carbonaceous Component of Sarin: Teaching E. coli to Eat Isopropanol

DEFF Research Database (Denmark)

Brown, Margaret E.; Mukhopadhyay, Aindrila; Keasling, Jay D.

2016-01-01

conversion with a key reaction performed by the acetone carboxylase complex (ACX). We engineered the heterologous expression of the ACX complex from Xanthobacter autotrophicus PY2 to match the naturally occurring subunit stoichiometry and purified the recombinant complex from E. coli for biochemical analysis....... Incorporating this ACX complex and enzymes from diverse organisms, we introduced an isopropanol degradation pathway in E. coli, optimized induction conditions, and decoupled enzyme expression to probe pathway bottlenecks. Our engineered E. coli consumed 65% of isopropanol compared to no-cell controls......We report an engineered strain of Escherichia coli that catabolizes the carbonaceous component of the extremely toxic chemical warfare agent sarin. Enzymatic decomposition of sarin generates isopropanol waste that, with this engineered strain, is then transformed into acetyl-CoA by enzymatic...

Carbonaceous particles and aerosol mass closure in PM2.5 collected in a port city

Science.gov (United States)

Genga, A.; Ielpo, P.; Siciliano, T.; Siciliano, M.

2017-01-01

Mass concentrations of PM2.5, mineral dust, organic carbon (OC) and elemental carbon (EC), water-soluble organic carbon (WSOC), sea salts and anthropogenic metals have been studied in a city-port of south Italy (Brindisi). This city is characterized by different emission sources (ship, vehicular traffic, biomass burning and industrial emissions) and it is an important port and industrial site of the Adriatic sea. Based on diagnostic ratios of carbonaceous species we assess the presence of biomass burning emissions (BBE), fossil fuel emissions (FFE) and ship emission (SE). Our proposed conversion factors from OC to OM are higher than those reported in the literature for urban site: the reason of this could be due to the existence of aged combustion aerosols during the sampling campaign (WSOC/OC = 0.6 ± 0.3).

Isotope source apportionment of carbonaceous aerosol as a function of particle size and thermal refractiveness

Science.gov (United States)

Masalaite, Agne; Holzinger, Rupert; Remeikis, Vidmantas; Röckmann, Thomas; Dusek, Ulrike

2016-04-01

The stable carbon isotopes can be used to get information about sources and processing of carbonaceous aerosol. We will present results from source apportionment of carbonaceous aerosol as a function of particle size thermal refractiveness. Separate source apportionment for particles smaller than 200 nm and for different carbon volatility classes are rarely reported and give new insights into aerosol sources in the urban environment. Stable carbon isotope ratios were measured for the organic carbon (OC) fraction and total carbon (TC) of MOUDI impactor samples that were collected on a coastal site (Lithuania) during the winter 2012 and in the city of Vilnius (Lithuania) during the winter of 2009. The 11 impactor stages spanned a size range from 0.056 to 18 μm, but only the 6 stages in the submicron range were analysed. The δ13C values of bulk total carbon (δ13CTC) were determined with an elemental analyser (Flash EA 1112) coupled with an isotope ratio mass spectrometer (Thermo Finnigan Delta Plus Advantage) (EA - IRMS). Meanwhile δ13COC was measured using thermal-desorption isotope ratio mass spectrometry (IRMS) system. This allows a rough separation of the more volatile OC fraction (desorbed in the oven of IRMS up to 250 0C) from the more refractory fraction (desorbed up to 400 0C). In this study we investigated the composition of organic aerosol desorbed from filter samples at different temperatures using the thermal-desorption proton-transfer-reaction mass spectrometry (TD-PTR-MS) technique. During winter-time in Lithuania we expect photochemistry and biogenic emissions to be of minor importance. The main sources of aerosol carbon should be fossil fuel and biomass combustion. In both sites, the coastal and the urban site, δ13C measurements give a clear indication that the source contributions differ for small and large particles. Small particles < 200 nm are depleted in 13C with respect to larger particles by 1 - 2 ‰Ṫhis shows that OC in small particle

Elements of Eoarchean life trapped in mineral inclusions

DEFF Research Database (Denmark)

Hassenkam, T.; Andersson, M. P.; Dalby, K. N.

2017-01-01

with carbon-rich sedimentary beds in the host rock, where carbon is fully graphitized. Previous studies have not been able to document other elements of life (mainly hydrogen, oxygen, nitrogen and phosphorus) structurally bound to this carbonaceous material. Here we study carbonaceous inclusions armoured...... residues within sedimentary material corroborates earlier claims for the biogenic origins of carbon in Isua metasediments....

ACCRETION AND PRESERVATION OF D-RICH ORGANIC PARTICLES IN CARBONACEOUS CHONDRITES: EVIDENCE FOR IMPORTANT TRANSPORT IN THE EARLY SOLAR SYSTEM NEBULA

International Nuclear Information System (INIS)

Remusat, L.; Guan, Y.; Wang, Y.; Eiler, J. M.

2010-01-01

We have acquired NanoSIMS images of the matrices of CI, CM, and CR carbonaceous chondrites to study, in situ, the organic matter trapped during the formation of their parent bodies. D/H ratio images reveal the occurrence of D-rich hot spots, constituting isolated organic particles. Not all the organic particles are D-rich hot spots, indicating that at least two kinds of organic particles have been accreted in the parent bodies. Ratio profiles through D-rich hot spots indicate that no significant self-diffusion of deuterium occurs between the D-rich organic matter and the depleted hydrous minerals that are surrounding them. This is not the result of a physical shielding by any constituent of the chondrites. Ab initio calculations indicate that it cannot be explained by isotopic equilibrium. Then it appears that the organic matter that is extremely enriched in D does not exchange with the hydrous minerals, or this exchange is so slow that it is not significant over the 4.5 billion year history on the parent body. If we consider that the D-rich hot spots are the result of an exposure to intense irradiation, then it appears that carbonaceous chondrites accreted organic particles that have been brought to different regions of the solar nebula. This is likely the result of important radial and vertical transport in the early solar system.

Observationally constrained estimates of carbonaceous aerosol radiative forcing.

Science.gov (United States)

Chung, Chul E; Ramanathan, V; Decremer, Damien

2012-07-17

Carbonaceous aerosols (CA) emitted by fossil and biomass fuels consist of black carbon (BC), a strong absorber of solar radiation, and organic matter (OM). OM scatters as well as absorbs solar radiation. The absorbing component of OM, which is ignored in most climate models, is referred to as brown carbon (BrC). Model estimates of the global CA radiative forcing range from 0 to 0.7 Wm(-2), to be compared with the Intergovernmental Panel on Climate Change's estimate for the pre-Industrial to the present net radiative forcing of about 1.6 Wm(-2). This study provides a model-independent, observationally based estimate of the CA direct radiative forcing. Ground-based aerosol network data is integrated with field data and satellite-based aerosol observations to provide a decadal (2001 through 2009) global view of the CA optical properties and direct radiative forcing. The estimated global CA direct radiative effect is about 0.75 Wm(-2) (0.5 to 1.0). This study identifies the global importance of BrC, which is shown to contribute about 20% to 550-nm CA solar absorption globally. Because of the inclusion of BrC, the net effect of OM is close to zero and the CA forcing is nearly equal to that of BC. The CA direct radiative forcing is estimated to be about 0.65 (0.5 to about 0.8) Wm(-2), thus comparable to or exceeding that by methane. Caused in part by BrC absorption, CAs have a net warming effect even over open biomass-burning regions in Africa and the Amazon.

Characterization of sorbent properties of soil organic matter and carbonaceous geosorbents using n-alkanes and cycloalkanes as molecular probes.

Science.gov (United States)

Endo, Satoshi; Grathwohl, Peter; Haderlein, Stefan B; Schmidt, Torsten C

2009-01-15

Nonspecific interactions and modes (i.e., adsorption vs absorption) of sorption by noncondensed, amorphous organic phases (here termed organic matter; OM) in soils and by rigid, aromatic, and condensed phases (termed carbonaceous geosorbents; CGs) were investigated using n-alkanes and cycloalkanes as molecular probes. Sorption isotherms of n- and cyclooctane from water for seven CGs (charcoal, lignite coke, activated carbon, graphite, partially oxidized graphite, diesel soot, bituminous coal), four sorbents with a predominance of OM (lignite, peat, two sapric soils), and two soils containing OM and high amounts of CGs were measured in batch systems. The peat and the sapric soils showed extensively linear sorption, while the CGs exhibited highly nonlinear (Freundlich exponents 0.2-0.7) and strong (Koc values being up to 10(5) times those for the OM-rich materials at low concentrations) sorption for the alkanes studied, showing that enhanced sorption by CGs can occur to completely apolar sorbates that do not undergo any specific interaction. Sorption by CGs was generally stronger and more nonlinear for n-octane than for cyclooctane, which suggests a strong dependence of sorption on the 3-D structure of sorbate molecules. The n-octane-to-cyclooctane sorption coefficient ratios (Kn/Kc) for adsorption to CGs were > or = 1, being distinctly different from those for absorption to the OM-rich materials (Kn/Kc soils determined by quantitative petrography analysis suggest, however, that CGs occurring in soils may be far less effective sorbents than the reference CGs used in the sorption experiments at least for nonspecifically interacting sorbates, probably because of competitive sorption and/or pore blocking by natural OM. The presented approaches and results offer a basis for interpreting sorption data for other organic compounds, as nonspecific interactions and sorption modes are relevant for any compound.

Preliminary Broadband Measurements of Dielectric Permittivity of Planetary Regolith Analog Materials Using a Coaxial Airline

Science.gov (United States)

Boivin, A.; Tsai, C. A.; Ghent, R. R.; Daly, M. G.

2014-12-01

When considering radar observations of airless bodies containing regolith, the radar backscatter coefficient is dependent upon the complex dielectric permittivity of the regolith materials. In many current applications of imaging radar data, uncertainty in the dielectric permittivity precludes quantitative estimates of such important parameters as regolith thickness and depth to buried features (e.g., lava flows on the Aristarchus Plateau on the Moon and the flows that surround the Quetzalpetlatl Corona on Venus). For asteroids, radar is an important tool for detecting and characterizing regoliths. Many previous measurements of the real and/or complex parts of the dielectric permittivity have been made, particularly for the Moon (on both Apollo samples and regolith analogues). However, no studies to date have systematically explored the relationship between permittivity and the various mineralogical components such as presence of FeO and TiO2. For lunar materials, the presence of the mineral ilmenite (FeTiO3), which contains equal portions FeO and TiO2, is thought to be the dominant factor controlling the loss tangent (tanδ, the ratio of the imaginary and real components of the dielectric permittivity). Ilmenite, however, is not the only mineral to contain iron in the lunar soil and our understanding of the effect of iron on the loss tangent is insufficient. Beyond the Moon, little is known about the effects on permittivity of carbonaceous materials. This is particularly relevant for missions to asteroids, such as the OSIRIS-REx mission to (101955) Bennu, a carbonaceous asteroid whose regolith composition is largely unknown. Here we present preliminary broadband (300 Mhz to 14 GHz) measurements on materials intended as planetary regolith analogs. Our ultimate goal is to establish a database of the effects of a wide range mineralogical components on dielectric permittivity, in support of the OSIRIS REx mission and ongoing Earth-based radar investigation of the Moon

Nanostructured mesophase electrode materials: modulating charge-storage behavior by thermal treatment.

Science.gov (United States)

Kong, Hye Jeong; Kim, Saerona; Le, Thanh-Hai; Kim, Yukyung; Park, Geunsu; Park, Chul Soon; Kwon, Oh Seok; Yoon, Hyeonseok

2017-11-16

3D nanostructured carbonaceous electrode materials with tunable capacitive phases were successfully developed using graphene/particulate polypyrrole (PPy) nanohybrid (GPNH) precursors without a separate process for incorporating heterogeneous species. The electrode material, namely carbonized GPNHs (CGPNHs) featured a mesophase capacitance consisting of both electric double-layer (EDL) capacitive and pseudocapacitive elements at the molecular level. The ratio of EDL capacitive element to pseudocapacitive element (E-to-P) in the mesophase electrode materials was controlled by varying the PPy-to-graphite weight (P w /G w ) ratio and by heat treatment (T H ), which was demonstrated by characterizing the CGPNHs with elemental analysis, cyclic voltammetry, and a charge/discharge test. The concept of the E-to-P ratio (EPR) index was first proposed to easily identify the capacitive characteristics of the mesophase electrode using a numerical algorithm, which was reasonably consistent with the experimental findings. Finally, the CGPNHs were integrated into symmetric two-electrode capacitor cells, which rendered excellent energy and power densities in both aqueous and ionic liquid electrolytes. It is anticipated that our approach could be widely extended to fabricating versatile hybrid electrode materials with estimation of their capacitive characteristics.

Magnetic Evidence for a Partially Differentiated Carbonaceous Chondrite Parent Body and Possible Implications for Asteroid 21 Lutetia

Science.gov (United States)

Weiss, Benjamin; Carporzen, L.; Elkins-Tanton, L.; Shuster, D. L.; Ebel, D. S.; Gattacceca, J.; Binzel, R. P.

2010-10-01

The origin of remanent magnetization in the CV carbonaceous chondrite Allende has been a longstanding mystery. The possibility of a core dynamo like that known for achondrite parent bodies has been discounted because chondrite parent bodies are assumed to be undifferentiated. Here we report that Allende's magnetization was acquired over several million years (Ma) during metasomatism on the parent planetesimal in a > 20 microtesla field 8-9 Ma after solar system formation. This field was present too recently and directionally stable for too long to have been the generated by the protoplanetary disk or young Sun. The field intensity is in the range expected for planetesimal core dynamos (Weiss et al. 2010), suggesting that CV chondrites are derived from the outer, unmelted layer of a partially differentiated body with a convecting metallic core (Elkins-Tanton et al. 2010). This suggests that asteroids with differentiated interiors could be present today but masked under chondritic surfaces. In fact, CV chondrites are spectrally similar to many members of the Eos asteroid family whose spectral diversity has been interpreted as evidence for a partially differentiated parent asteroid (Mothe-Diniz et al. 2008). CV chondrite spectral and polarimetric data also resemble those of asteroid 21 Lutetia (e.g., Belskaya et al. 2010), recently encountered by the Rosetta spacecraft. Ground-based measurements of Lutetia indicate a high density of 2.4-5.1 g cm-3 (Drummond et al. 2010), while radar data seem to rule out a metallic surface composition (Shepard et al. 2008). If Rosetta spacecraft measurements confirm a high density and a CV-like surface composition for Lutetia, then we propose Lutetia may be an example of a partially differentiated carbonaceous chondrite parent body. Regardless, the very existence of primitive achondrites, which contain evidence of both relict chondrules and partial melting, are prima facie evidence for the formation of partially differentiated bodies.

Molecular and elemental analyses of the carbonaceous matter in the gold and uranium bearing Vaal Reef carbon seams, Witwatersrand sequence

International Nuclear Information System (INIS)

Zumberge, J.E.; Sigleo, A.C.; Nagy, B.

1978-01-01

The thin Vaal Reef carbon seams consist of a complex, solid, and solvent insoluble, polymer-like substance, containing mainly hydrocarbons and some organic sulphur and oxygen compounds. These carbon seams are not pure carbon, e.g. graphite, and do not contain only hydrocarbons. According to modern terminology the Vaal Reef carbonaceous matter is most appropriately referred to as kerogen rather than carbon or thucholite. This kerogen is not the result of the polymerization of gaseous or liquid hydrocarbons, but rather of the polymerization of biochemicals from decayed, primitive Precambrian micro-organisms. These microbiota formed mats in which uranium minerals and gold became incorporated before burial under younger sediments. Organic geochemistry was first developed as a means to elucidate the nature and composition of petroleum and coal. Later it was successfully used in lunar sample, planetary surface, and meteorite studies as well as in investigations of kerogens in terrestrial sediments of various ages. Considering economic geology, organic geochemistry holds promise for elucidating the origin and helping in the exploration of carbonaceous ore deposits. The purpose of this report is to review some of the major current organic geochemical methods and to illustrate these by the analysis of the Vaal Reef kerogen. The samples were analysed by a directly connected high vacuum pyrolysis system-gas chromatograph-organic mass spectrometer. Additional analyses were performed by a combined scanning electron microscope-electron microprobe, by the techniques of electron paramagnetic resonance spectroscopy, and by neutron activation analysis

Simulating the formation of carbonaceous aerosol in a European Megacity (Paris during the MEGAPOLI summer and winter campaigns

Directory of Open Access Journals (Sweden)

C. Fountoukis

2016-03-01

Full Text Available We use a three-dimensional regional chemical transport model (PMCAMx with high grid resolution and high-resolution emissions (4 × 4 km2 over the Paris greater area to simulate the formation of carbonaceous aerosol during a summer (July 2009 and a winter (January/February 2010 period as part of the MEGAPOLI (megacities: emissions, urban, regional, and global atmospheric pollution and climate effects, and Integrated tools for assessment and mitigation campaigns. Model predictions of carbonaceous aerosol are compared against Aerodyne aerosol mass spectrometer and black carbon (BC high time resolution measurements from three ground sites. PMCAMx predicts BC concentrations reasonably well reproducing the majority (70 % of the hourly data within a factor of two during both periods. The agreement for the summertime secondary organic aerosol (OA concentrations is also encouraging (mean bias = 0.1 µg m−3 during a photochemically intense period. The model tends to underpredict the summertime primary OA concentrations in the Paris greater area (by approximately 0.8 µg m−3 mainly due to missing primary OA emissions from cooking activities. The total cooking emissions are estimated to be approximately 80 mg d−1 per capita and have a distinct diurnal profile in which 50 % of the daily cooking OA is emitted during lunch time (12:00–14:00 LT and 20 % during dinner time (20:00–22:00 LT. Results also show a large underestimation of secondary OA in the Paris greater area during wintertime (mean bias =  −2.3 µg m−3 pointing towards a secondary OA formation process during low photochemical activity periods that is not simulated in the model.

Simulating the formation of carbonaceous aerosol in a European Megacity (Paris) during the MEGAPOLI summer and winter campaigns

Science.gov (United States)

Fountoukis, Christos; Megaritis, Athanasios G.; Skyllakou, Ksakousti; Charalampidis, Panagiotis E.; Denier van der Gon, Hugo A. C.; Crippa, Monica; Prévôt, André S. H.; Fachinger, Friederike; Wiedensohler, Alfred; Pilinis, Christodoulos; Pandis, Spyros N.

2016-03-01

We use a three-dimensional regional chemical transport model (PMCAMx) with high grid resolution and high-resolution emissions (4 × 4 km2) over the Paris greater area to simulate the formation of carbonaceous aerosol during a summer (July 2009) and a winter (January/February 2010) period as part of the MEGAPOLI (megacities: emissions, urban, regional, and global atmospheric pollution and climate effects, and Integrated tools for assessment and mitigation) campaigns. Model predictions of carbonaceous aerosol are compared against Aerodyne aerosol mass spectrometer and black carbon (BC) high time resolution measurements from three ground sites. PMCAMx predicts BC concentrations reasonably well reproducing the majority (70 %) of the hourly data within a factor of two during both periods. The agreement for the summertime secondary organic aerosol (OA) concentrations is also encouraging (mean bias = 0.1 µg m-3) during a photochemically intense period. The model tends to underpredict the summertime primary OA concentrations in the Paris greater area (by approximately 0.8 µg m-3) mainly due to missing primary OA emissions from cooking activities. The total cooking emissions are estimated to be approximately 80 mg d-1 per capita and have a distinct diurnal profile in which 50 % of the daily cooking OA is emitted during lunch time (12:00-14:00 LT) and 20 % during dinner time (20:00-22:00 LT). Results also show a large underestimation of secondary OA in the Paris greater area during wintertime (mean bias = -2.3 µg m-3) pointing towards a secondary OA formation process during low photochemical activity periods that is not simulated in the model.

Soot, organics, and ultrafine ash from air- and oxy-fired coal combustion

KAUST Repository

Andersen, Myrrha E.; Modak, Nabanita; Winterrowd, Christopher K.; Lee, Chun Wai; Roberts, William L.; Wendt, Jost O L; Linak, William P.

2016-01-01

-fired combustion conditions consists primarily of carbonaceous material (50-95%). Carbonaceous components on particles <0.6. μm measured by a thermal optical method showed that large fractions (52-93%) consisted of OC rather than EC, as expected. This observation

Extensive Sorption of Organic Compounds to Black Carbon, Coal and Kerogen in Sediments and Soils: Mechanisms and Consequences for Distribution, Bioaccumulation and Biodegradation (Critical Review)

NARCIS (Netherlands)

Cornelissen, G.; Gustafsson, O.; Bucheli, T.D.; Jonker, M.T.O.; Koelmans, A.A.; Noort, van P.C.M.

2005-01-01

Evidence is accumulating that sorption of organic chemicals to soils and sediments can be described by "dual-mode sorption": absorption in amorphous organic matter (AOM) and adsorption to carbonaceous materials such as black carbon (BC), coal, and kerogen, collectively termed "carbonaceous

Nanostructured Carbon Materials as Supports in the Preparation of Direct Methanol Fuel Cell Electrocatalysts

Directory of Open Access Journals (Sweden)

María Jesús Lázaro

2013-08-01

Full Text Available Different advanced nanostructured carbon materials, such as carbon nanocoils, carbon nanofibers, graphitized ordered mesoporous carbons and carbon xerogels, presenting interesting features such as high electrical conductivity and extensively developed porous structure were synthesized and used as supports in the preparation of electrocatalysts for direct methanol fuel cells (DMFCs. The main advantage of these supports is that their physical properties and surface chemistry can be tailored to adapt the carbonaceous material to the catalytic requirements. Moreover, all of them present a highly mesoporous structure, diminishing diffusion problems, and both graphitic character and surface area can be conveniently modified. In the present work, the influence of the particular features of each material on the catalytic activity and stability was analyzed. Results have been compared with those obtained for commercial catalysts supported on Vulcan XC-72R, Pt/C and PtRu/C (ETEK. Both a highly ordered graphitic and mesopore-enriched structure of these advanced nanostructured materials resulted in an improved electrochemical performance in comparison to the commercial catalysts assayed, both towards CO and alcohol oxidation.

Rational design of carbon and TiO2 assembly materials: covered or strewn, which is better for photocatalysis?

Science.gov (United States)

Cui, Guan-wei; Wang, Wei-liang; Ma, Ming-yue; Zhang, Ming; Xia, Xin-yuan; Han, Feng-yun; Shi, Xi-feng; Zhao, Ying-qiang; Dong, Yu-bin; Tang, Bo

2013-07-21

The rational design of carbonaceous hybrid nanostructures is very important for obtaining high photoactivity. TiO2 particles strewn with an optimal quantity of carbon nanodots have a much higher photoactivity than that of TiO2 covered with a carbon layer, showing the importance of carbon morphology in the photocatalysis of carbonaceous hybrid nanostructures.

Pair distribution functions of carbonaceous solids, determined using energy filtered diffraction

International Nuclear Information System (INIS)

Petersen, T.C.; McCulloch, D.G.

2002-01-01

Full text: The structures of various carbonaceous solids were investigated using energy filtered diffraction patterns collected in two dimensions using a Gatan Imaging Filter (GIF). In order to reduce multiple scattering and eliminate inelastic scattering effects, the diffraction patterns were filtered using an energy -selecting slit around the zero-loss peak. Software has been developed for the extraction of radially averaged pair distributions functions from the diffraction data. This entails finding the position of the un-scattered beam, radially averaging the two dimensional intensity distributions, calibrating the resulting one dimensional intensity profiles and finally normalising the data to obtain structure factors. Techniques for improving and assessing data quality, pertaining to the methodology used here, have also been explored. Structure factors and radial distribution functions generated using this analysis will be discussed and, for the commercial V25 glassy carbon samples, compared to previous, work of one of the authors'. In order to answer questions regarding multiple scattering effects and structural homogeneity of the samples, neutron scattering was performed on the Medium Resolution Powder Diffractometer (MRPD), at the Australian Nuclear Science and Technology's (ANSTO) facility. A critical comparison of the neutron scattering and electron diffraction generated structure factors will be presented. Copyright (2002) Australian Society for Electron Microscopy Inc

Search for Fluid Inclusions in a Carbonaceous Chondrite Using a New X-Ray Micro-Tomography Technique Combined with FIB Sampling

Science.gov (United States)

Tsuchiyama, A.; Miyake, A.; Zolensky, M. E.; Uesugi, K.; Nakano, T.; Takeuchi, A.; Suzuki, Y.; Yoshida, K.

2014-01-01

daughter crystal inside (three-phase inclusion). As we know the exact 3D position of the inclusion, we will anlyze the inclusion by SIMS after freezing the sample as has been done for a halite sample [3]. The present technique is useful for finding small inclusions not only in carbonaceous chondrites but also for terrestrial materials.

FY 1998 report on the results of the R and D of industrial science technology. R and D of 'carbon-base high functional material technology' (R and D of the submarine oil production support system); 1998 nendo sangyo kagaku gijutsu kenkyu kaihatsu seika hokokusho. Tansokei kokino zairyo gijutsu no kenkyu kaihatsu (kaitei sekiyu seisan shien system kenkyu kaihatsu)

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-09-01

For the R and D of carbon-base high functional materials, the paper reported on (1) material creation technology and (2) creation of mechanically high functional materials. In (1), the synthesis of new BCN-base materials is conducted by the electronic excitation CVD method and high temperature/high pressure (explosive synthesis) with the aim of analyzing the composition/structure. Using energy-controlled ion beams and laser beams, the synthesis of new CN-base materials and analysis of composition/structure are aimed at. By the thermal CVD method using catalysts, a method to synthesize a quantity of nanotubes is aimed at. The paper is aimed at clarifying the reaction mechanism on the material conversion of carbonaceous materials relating to the above-mentioned three methods and the appearance mechanism of characteristics of carbonaceous materials. (2) is composed of the following three subjects: composition gradient film formation technology, complicated shape film formation/micro-processing technology, and large area film formation. These three subjects were studied to positively make use of characteristics such as low friction/low abrasion and high temperature corrosion resistance which can be expected in amorphous carbon, diamond and high functional carbon materials of carbon nitride and to apply them to moving parts of various industrial machines and surface protection of construction materials such as glass, etc. (NEDO)

Corrosion behaviour of reinforcements in a carbonaceous concrete: influence of the chemistry of the interstitial solution and of a transport barrier

International Nuclear Information System (INIS)

Huet, B.

2005-10-01

The phenomenon of steel reinforcements corrosion in a carbonaceous concrete is a many-sided process, little understood and of a great economical importance. The aim of this work is to identify, in condition of concrete carbonation, the corrosion mechanisms of reinforcements in order to anticipate the long term damage of the buildings. An analytical and experimental study has been carried out and has revealed two hypotheses. These ones consist to characterize the control of the corrosion velocity, either by the anodic reaction or by addition of an oxidant. The corrosion experiments in solution which represents the interstitial solution of a carbonaceous cement paste show that the evolution of the metal/medium interface is very sensitive to the species introduced in the medium during the carbonation process. The change of the ionic strength and of the sulfate and alkali metals concentrations are the main factors influencing the localization of the reactional areas, the nature of the phases formed at the interface as well as the corrosion velocities and their change with time. The evolution of the water saturation degree of the coating is the preponderant factor on the corrosion velocity. The analytical calculations and the experimental results show that for fixed hydrous conditions, the corrosion velocity in stationary conditions is negligible. The taking into account of transient conditions of transport as well as humidification and drying cycles is required for the long term anticipation of the damage of reinforced concrete buildings. (O.M.)

Removal of mercury from water by carbonaceous sorbents derived from walnut shell

International Nuclear Information System (INIS)

Zabihi, M.; Ahmadpour, A.; Asl, A. Haghighi

2009-01-01

The adsorption ability of a powdered activated carbon (PAC) derived from walnut shell was investigated in an attempt to produce more economic and effective sorbent for the control of Hg(II) ion from industrial liquid streams. Carbonaceous sorbents derived from Iranian walnut shell (WS) were prepared by chemical activation method using ZnCl 2 as an activating reagent. To the best of our knowledge, this adsorbent was not used before for removing mercury from water. Adsorption of Hg(II) from aqueous solutions was carried out under different experimental conditions by varying treatment time, metal ion concentration, adsorbent amount, pH and solution temperature. It was determined that Hg(II) adsorption follows both Langmuir and Freundlich isotherms as well as pseudo-second-order kinetics. It was also shown that Hg(II) uptake decreases with increasing pH of the solution. The proper choice of preparation conditions resulted in a microporous activated carbon with 0.45 g/cm 3 density, 737 mg/g iodine number and 780 m 2 /g BET surface area. The monolayer sorption capacity of this optimum adsorbent was obtained as 151.5 mg/g.

The mercury species and their association with carbonaceous compositions, bromine and iodine in PM2.5 in Shanghai.

Science.gov (United States)

Duan, Lian; Xiu, Guangli; Feng, Ling; Cheng, Na; Wang, Chenggang

2016-03-01

PM2.5 samples were collected in south Shanghai from November 2013 to October 2014. The species of particulate bounded mercury (PBM), including hydrochloric soluble particle-phase mercury (HPM), element soluble particle-phase mercury (EPM) and residual soluble particle-phase mercury (RPM), were determined in PM2.5. The chemical composition of PM2.5 including organic carbon (OC) and elemental carbon (EC), total bromine and iodine were also analyzed. The results showed that the annual average concentration of PBM was 0.30 ± 0.31 ng m(-3) and 0.34 ± 0.32 ng m(-3) in winter, 0.31 ± 0.19 ng m(-3) in spring, 0.30 ± 0.45 ng m(-3) in fall and 0.28 ± 0.17 ng m(-3) in summer. HPM took the highest fraction 51.2% in PBM, followed by RPM 27.7% and EPM 21.1%. EC positively correlated to particle mercury, especially in winter (r = 0.70), the same for OC in winter (r = 0.72), which indicated that the carbonaceous composition may affect the transformation of Hg in the atmosphere. Mercury species showed different correlations with bromine and iodine in the four seasons. The strongest correlation between bromine, iodine and mercury was found in spring and fall, respectively. Bromine showed the stronger correlation with total mercury and speciated particle mercury than iodine. In addition, the days were classified into haze and non-haze days based on the visibility and relative humidity, while the ratio of HPM in haze days was much higher than that in non-haze days. EC strongly correlated with PBM during haze and non-haze days while OC only positively correlated with PBM in non-haze days, this may indicate that the different carbonaceous part may affect PBM differently. Copyright © 2015 Elsevier Ltd. All rights reserved.

A new method to determine the mixing state of light absorbing carbonaceous using the measured aerosol optical properties and number size distributions

Directory of Open Access Journals (Sweden)

N. Ma

2012-03-01

Full Text Available In this paper, the mixing state of light absorbing carbonaceous (LAC was investigated with a two-parameter aerosol optical model and in situ aerosol measurements at a regional site in the North China Plain (NCP. A closure study between the hemispheric backscattering fraction (HBF measured by an integrating nephelometer and that calculated with a modified Mie model was conducted. A new method was proposed to retrieve the ratio of the externally mixed LAC mass to the total mass of LAC (r_ext-LAC based on the assumption that the ambient aerosol particles were externally mixed and consisted of a pure LAC material and a core-shell morphology in which the core is LAC and the shell is a less absorbing material. A Monte Carlo simulation was applied to estimate the overall influences of input parameters of the algorithm to the retrieved r_ext-LAC. The diurnal variation of r_ext-LAC was analyzed and the PartMC-MOSAIC model was used to simulate the variation of the aerosol mixing state. Results show that, for internally mixed particles, the assumption of core-shell mixture is more appropriate than that of homogenous mixture which has been widely used in aerosol optical calculations. A significant diurnal pattern of the retrieved r_ext-LAC was found, with high values during the daytime and low values at night. The consistency between the retrieved r_ext-LAC and the model results indicates that the diurnal variation of LAC mixing state is mainly caused by the diurnal evolution of the mixing layer.

Facile synthesis of α-Fe{sub 2}O{sub 3}@ porous hollow yeast-based carbonaceous microspheres for fluorescent whitening agent-VBL wastewater treatment

Energy Technology Data Exchange (ETDEWEB)

Zheng, Pei; Tong, Zhiqing [College of Environmental Science and Engineering, Chang' an University, Xi' an 710054 (China); Bai, Bo, E-mail: baibochina@163.com [Key Laboratory of Tibetan Medicine Research, Northwest Plateau Institute of Biology, Chinese Academy of Sciences, Xining 810001 (China)

2016-03-15

Porous hollow carbonaceous microspheres (PHCMs) fabricated from yeast cells by hydrothermal treatment have stimulated interest because of their outstanding chemical and physical properties. Herein, the functionalizations of PHCMs by further coating of α-Fe{sub 2}O{sub 3} nanoparticles onto the surface were carried out. The structure of resulted α-Fe{sub 2}O{sub 3}@PHCMs products were characterized by field emission scanning electron microscopy (FE-SEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and BET specific surface area measurements (BET), respectively. Its promising application was evaluated by the Fenton-like degradation of fluorescent whitening agent-VBL from aqueous solutions. - Graphical abstract: In this work, novel α-Fe{sub 2}O{sub 3}@porous hollow carbonaceous microspheres (α-Fe{sub 2}O{sub 3}@PHCMs) were synthesized through a combination of hydrothermal method and calcinations route and achieved excellent removal efficiency for fluorescent whitening Agent-VBL. - Highlights: • The hybrid α-Fe{sub 2}O{sub 3}@ porous hollow microspheres (PHCMs) were firstly fabricated. • The formation mechanism of α-Fe{sub 2}O{sub 3}@PHCMs microspheres was proposed and verified. • Dithizone played a key role in the synthesis of α-Fe{sub 2}O{sub 3}@PHCMs composites. • A favorable removal for the fluorescent whitening agent-VBL were achieved.

Accretion and Preservation of Organic Matter in Carbonaceous Chondrites as Revealed by NanoSIMS Imaging.

Science.gov (United States)

Remusat, L.; Guan, Y.; Eiler, J.

2008-12-01

Carbonaceous chondrites are the most primitive known meteorites. Their parent bodies accreted several discrete components of the early solar system: CAIs, other silicates, oxides, sulfides, ice, organics, and noble gases. Radioactive decay of short live radionucleides quickly heated these parent bodies and drove thermal metamorphism and aqueous alteration of their constituents. Despite this post-acretionary modification, at least some components of the organic matter in the carbaceous chondrites retained distinctive isotopic and molecular properties that may relate to their pre-acretionary origins in the protosolar nebula or in the molecular cloud that gave birth to it [1]. These processes that gave rise to early solar-system organic matter and the extent to which it was modified by parent body processes are still a matter of debate [2]. We have acquired NanoSIMS images of matrices of several CI, CM, CR and CV chondrites to document, in- situ, the distribution of organics and their textural and chemical relationships to co-existing inorganic components. Importantly, we performed these analyses on essentially unmodified fragments of matrix material pressed into indium, rather than on extracts, which have been the focus of most previous work on meteoritic organic matter. Specifically, we simultaneously collected H, D, 12C, 18O, 26CN, 28Si and 32S with a spatial resolution of 200 nm. Inorganic constituents of the imaged domains were determined by SEM imaging and EDS analysis. We identify two textural classes of organic constituents: diffuse organic matter and organic particles ~ 1 micron in diameter. The particles are common and do not exhibit any textural association with any inorganic matrix constituent. This distribution is consistent with previous observations by fluorescence optical microscopy [3]. These organic particles are likely primarily composed of insoluble organic matter (IOM) that grew prior to accretion as pure organic particules and was preserved in

Isolating Weakly and Strongly-Absorbing Classes of Carbonaceous Aerosol: Optical Properties, Abundance and Lifecycle

Energy Technology Data Exchange (ETDEWEB)

Bond, Tami C. [Univ. of Illinois, Urbana-Champaign, IL (United States); Rood, Mark J. [Univ. of Illinois, Urbana-Champaign, IL (United States); Riemer, Nicole [Univ. of Illinois, Urbana-Champaign, IL (United States)

2013-09-15

The goal of this project was to evaluate climate-relevant properties of carbonaceous particles and the transformations of those particles in the atmosphere, with the purpose of developing lumped classes of carbonaceous particles suitable for use in large-scale models. These climate-relevant properties included light absorption and hygroscopicity. Hygroscopicity is a measure of water affinity, which governs particle growth at humid conditions and absorption and scattering under those conditions. It also controls particles’ activation into cloud droplets, which in turn affects cloud albedo and particle removal. This project used laboratory measurements of fresh and aged carbonaceous aerosol, and predictions of properties using a particle-resolved model, to identify sensitivities. The focus in this project was on aerosol from biomass pyrolysis, abbreviated BrC (“brown carbon”). We measured absorption by aerosol from biomass pyrolysis from two sources with very different composition: wood and corn stalk. For both sources, the greatest light absorption occurred at the highest generation temperature, and this maximum absorption was very similar to that of wood-generated aerosol. We suggest that pyrolysis products can be considered surrogates for a wide range of biomass aerosol. We captured aerosol emitted from biomass pyrolysis on filters and exposed it to ultraviolet radiation, to the atmospheric trace gases ozone, ammonia (NH₃) and nitrogen oxide; and to aqueous saturated salt solutions of ammonium sulfate, ammonium nitrate, sodium chloride and sodium sulfate. Absorption increased, but by only small amounts for all of these treatments, with one exception: after aging with ammonia, absorption increased by almost a factor of four. Absorption increased more at visible wavelengths. We confirmed that a significant change occurred in the aerosol phase, by measuring absorption by suspended particles after aging with NH₃ and finding doubled aerosol

Carbonaceous species (coke) characterization in zeolites by solid state {sup 13} C NMR; Caracterizacao de especies carbonaceas (coque) em zeolitos por RMN de {sup 13} C estado solido (CP/MAS)

Energy Technology Data Exchange (ETDEWEB)

Mota, Claudio J.A.; Menezes, Sonia C [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

1992-12-31

This work applies solid state {sup 13} C NMR for characterization of carbonaceous species (coke) deposited on zeolites after contact with n-hexane at 370 deg C. The results have shown two types of carbon: saturated (sp{sup 3}) and unsaturated (sp{sup 2}) 4 refs., 4 tabs.

Destructive distillation under pressure

Energy Technology Data Exchange (ETDEWEB)

1932-09-08

A process of destructive distillation of distillable carbonaceous material under pressure is described, consisting of regulating the temperature by introducing the carbonaceous materials to a point where the reaction of hydrogenation has begun but has not stopped, by placing it in indirect heat-exchange with a cooling agent at a critical temperature below the reaction temperature, the agent being under pressure and introduced in the liquid state. Water is used as the cooling agent.

Cobalt separation present in aqueous solution using shell tamarind as bio sorbent

International Nuclear Information System (INIS)

Hernandez L, J.

2014-01-01

In this work a new carbonaceous material is presented with improved adsorption properties obtained by a heart treatment about 5 min from the shell tamarind. It was found that the samples obtained carbonaceous adsorbents are effective in removing Co 2+ (41 mg / g) ions in aqueous solutions. These samples were prepared from tamarind shell, urea, ammonium nitrate and water. The solution was subjected to a combustion process at different temperatures. Carbonaceous samples prepared in this manner were characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy (Sem) and surface area measurements by Physisorption of N 2 . Changes in structure, morphology and texture were studied. The results show that this material is of great importance to the applications of adsorption of metal ions. The measurements of specific surface area (Bet) were 2.35 to 203.76 m 2 g -1 with pore diameters between 2.31 and 15.63 nm, indicating that the samples obtained are predominantly meso porous. The combustion process of the solution proved to be advantageous to improve the textural properties of the tamarind shell. The obtained carbonaceous material plays an important role in adsorption to remove cobalt in aqueous solutions. (Author)

Cobalt separation present in aqueous solution using shell tamarind as bio sorbent; Separacion de cobalto presente en solucion acuosa utilizando cascara de tamarindo como biosorbente

Energy Technology Data Exchange (ETDEWEB)

Hernandez L, J.

2014-07-01

In this work a new carbonaceous material is presented with improved adsorption properties obtained by a heart treatment about 5 min from the shell tamarind. It was found that the samples obtained carbonaceous adsorbents are effective in removing Co{sup 2+} (41 mg / g) ions in aqueous solutions. These samples were prepared from tamarind shell, urea, ammonium nitrate and water. The solution was subjected to a combustion process at different temperatures. Carbonaceous samples prepared in this manner were characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy (Sem) and surface area measurements by Physisorption of N{sub 2}. Changes in structure, morphology and texture were studied. The results show that this material is of great importance to the applications of adsorption of metal ions. The measurements of specific surface area (Bet) were 2.35 to 203.76 m{sup 2} g{sup -1} with pore diameters between 2.31 and 15.63 nm, indicating that the samples obtained are predominantly meso porous. The combustion process of the solution proved to be advantageous to improve the textural properties of the tamarind shell. The obtained carbonaceous material plays an important role in adsorption to remove cobalt in aqueous solutions. (Author)

Factors affecting the removal of ammonia from air on carbonaceous materials: Investigation of reactive adsorption mechanism

Science.gov (United States)

Petit, Camille

Air pollution related to the release of industrial toxic gases, represents one of the main concerns of our modern world owing to its detrimental effect on the environment. To tackle this growing issue, efficient ways to reduce/control the release of pollutants are required. Adsorption of gases on porous materials appears as a potential solution. However, the physisorption of small molecules of gases such as ammonia is limited at ambient conditions. For their removal, adsorbents providing strong adsorption forces must be used/developed. In this study, new carbon-based materials are prepared and tested for ammonia adsorption at ambient conditions. Characterization of the adsorbents' texture and surface chemistry is performed before and after exposure to ammonia to identify the features responsible for high adsorption capacity and for controlling the mechanisms of retention. The characterization techniques include: nitrogen adsorption, thermal analysis, potentiometric titration, FT-IR spectroscopy, X-ray diffraction, Energy Dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and Electron Microscopy. The results obtained indicate that ammonia removal is governed by the adsorbent's surface chemistry. On the contrary, porosity (and thus physisorption) plays a secondary role in this process, unless strong dispersive forces are provided by the adsorbent. The surface chemistry features responsible for the enhanced ammonia adsorption include the presence of oxygen-(carboxyl, hydroxyl, epoxy) and sulfur- (sulfonic) containing groups. Metallic species improve the breakthrough capacity as well as they lead to the formation of Lewis acid-base interactions, hydrogen-bonding or complexation. In addition to the latter three mechanisms, ammonia is retained on the adsorbent surface via Bronsted acid-base interactions or via specific reactions with the adsorbent's functionalities leading to the incorporation of ammonia into the adsorbent's matrix. Another mechanism

Potential impact of carbonaceous aerosol on the upper troposphere and lower stratosphere (UTLS) and precipitation during Asian summer monsoon in a global model simulation

KAUST Repository

Fadnavis, Suvarna

2017-09-28

Recent satellite observations show efficient vertical transport of Asian pollutants from the surface to the upper-level anticyclone by deep monsoon convection. In this paper, we examine the transport of carbonaceous aerosols, including black carbon (BC) and organic carbon (OC), into the monsoon anticyclone using of ECHAM6-HAM, a global aerosol climate model. Further, we investigate impacts of enhanced (doubled) carbonaceous aerosol emissions on the upper troposphere and lower stratosphere (UTLS), underneath monsoon circulation and precipitation from sensitivity simulations. The model simulation shows that boundary layer aerosols are transported into the monsoon anticyclone by the strong monsoon convection from the Bay of Bengal, southern slopes of the Himalayas and the South China Sea. Doubling of emissions of both BC and OC aerosols over Southeast Asia (10° S–50° N, 65–155° E) shows that lofted aerosols produce significant warming (0.6–1 K) over the Tibetan Plateau (TP) near 400–200 hPa and instability in the middle/upper troposphere. These aerosols enhance radiative heating rates (0.02–0.03 K day−1) near the tropopause. The enhanced carbonaceous aerosols alter aerosol radiative forcing (RF) at the surface by −4.74 ± 1.42 W m−2, at the top of the atmosphere (TOA) by +0.37 ± 0.26 W m−2 and in the atmosphere by +5.11 ± 0.83 W m−2 over the TP and Indo-Gangetic Plain region (15–35° N, 80–110° E). Atmospheric warming increases vertical velocities and thereby cloud ice in the upper troposphere. Aerosol induced anomalous warming over the TP facilitates the relative strengthening of the monsoon Hadley circulation and increases moisture inflow by strengthening the cross-equatorial monsoon jet. This increases precipitation amounts over India (1–4 mm day−1) and eastern China (0.2–2 mm day−1). These results are significant at the 99 % confidence level.

Assessment of carbonaceous aerosols in Shanghai, China – Part 1: long-term evolution, seasonal variations, and meteorological effects

Directory of Open Access Journals (Sweden)

Y. Chang

2017-08-01

Full Text Available Carbonaceous aerosols are major chemical components of fine particulate matter (PM2. 5 with major impacts on air quality, climate change, and human health. Gateway to fast-rising China and home of over twenty million people, Shanghai throbs as the nation's largest mega city and the biggest industrial hub. From July 2010 to December 2014, hourly mass concentrations of ambient organic carbon (OC and elemental carbon (EC in the PM2. 5 fraction were quasi-continuously measured in Shanghai's urban center. The annual OC and EC concentrations (mean ±1σ in 2013 (8.9 ± 6.2 and 2.6 ± 2.1 µg m−3, n =  5547 and 2014 (7.8 ± 4.6 and 2.1 ± 1.6 µg m−3, n =  6914 were higher than those of 2011 (6.3 ± 4.2 and 2.4 ± 1.8 µg m−3, n =  8039 and 2012 (5.7 ± 3.8 and 2.0 ± 1.6 µg m−3, n =  4459. We integrated the results from historical field measurements (1999–2012 and satellite observations (2003–2013, concluding that carbonaceous aerosol pollution in Shanghai has gradually reduced since 2006. In terms of monthly variations, average OC and EC concentrations ranged from 4.0 to 15.5 and from 1.4 to 4.7 µg m−3, accounting for 13.2–24.6 and 3.9–6.6 % of the seasonal PM2. 5 mass (38.8–94.1 µg m−3, respectively. The concentrations of EC (2.4, 2.0, 2.2, and 3.0 µg m−3 in spring, summer, fall, and winter, respectively showed little seasonal variation (except in winter and weekend–weekday dependence, indicating EC is a relatively stable constituent of PM2. 5 in the Shanghai urban atmosphere. In contrast to OC (7.3, 6.8, 6.7, and 8.1 µg m−3 in spring, summer, fall, and winter, respectively, EC showed marked diurnal cycles and correlated strongly with CO across all seasons, confirming vehicular emissions as the dominant source of EC at the targeted site. Our data also reveal that both OC and EC showed concentration gradients as a

Laboratory Studies Of Circumstellar Carbonaceous Grain Formation

Science.gov (United States)

Contreras, Cesar; Sciamma-O'Brien, Ella; Salama, Farid

2014-06-01

The study of the formation processes of dust is essential to understand the budget of extraterrestrial organic molecules. Although dust with all its components plays an important role in the evolution of interstellar (IS) chemistry and in the formation of organic molecules, little is known on the formation processes of carbonaceous dust. We report the progress that was recently achieved in this domain using NASA Ames’ COSmIC facility (Contreras & Salama 2013, ApJS, 208, 6). PAHs are important chemical building blocks of IS dust. They are detected in IDPs and in meteoritic samples. Additionally, observational, laboratory, and theoretical studies have shown that PAHs are an important, ubiquitous component of the ISM. The formation of PAHs from smaller molecules has not been extensively studied. Therefore, we have performed laboratory experiments to study the dynamic processes of carbon grain formation, starting from the smallest hydrocarbon molecules into the formation of larger PAH and further into nanograins. Studies of IS dust analogs formed from a variety of PAH and hydrocarbon precursors as well as species that include the atoms O, N, and S, have recently been performed in our laboratory using the COSmIC facility to provide conditions that simulate IS and circumstellar environments. The species formed in the COSmiC chamber through a pulsed discharge nozzle plasma source are detected and characterized with a cavity ringdown spectrometer coupled to a time-of-flight mass spectrometer, thus providing both spectroscopic and ion mass information in-situ. Analysis of solid soot particles was also conducted using scanning electron microscopy at the UCSC/NASA Ames’ MACS facility. The SEM analysis of the deposition of soot from methane and acetylene precursors seeded in argon plasmas provide examples on the types of nanoparticles and micrograins that are produced in these gas mixtures under our experimental conditions. From these measurements, we derive information on

Internal-standard method for the determination of uranium, thorium, lanthanum and europium in carbonaceous shale and monazite by epithermal neutron activation analysis

Energy Technology Data Exchange (ETDEWEB)

Chen, Shuenn-Gang; Tsai, Hui-Tuh; Wu, Shaw-Chii [Institute of Nuclear Energy Research, Lung-Tan (Taiwan, Republic of China)

1981-10-03

An internal-standard method was applied for the determination of uranium, thorium, lanthanum and europium is carbonaceous shale samples and monazite sand by epithermal neutron activation analysis using gold as an internal standard element. The samples were irradiated in a zero-power reactor at the Institute of Nuclear Energy Research and measured with a high-resolution Ge(Li) detector. The detection limit is 0.1 ppm for uranium and europium, 1 ppm for thorium, 5 ppm for lanthanum, and the realative error of all elements is within +-2.6%.

Artificial fuel

Energy Technology Data Exchange (ETDEWEB)

Hamon, L L.W.

1918-08-20

Lignite, peat, sud, leaf-mold, or shale, or two or more of these raw carbonaceous materials are mixed with cellulose material, such as sawdust, silica, alkali, and tar or pitch, or residues from tar or pitch, or residues from the distillation of oils, and the mixture is molded into blocks. Other carbonaceous materials, such as graphite, anthracite, or coal-dust, coke, breeze, or culm, and mineral substances, such as iron and manganese ores, may be added. A smokeless fuel can be obtained by coking the blocks in the usual way in retorts.

Development of new materials from waste electrical and electronic equipment: Characterization and catalytic application.

Science.gov (United States)

Souza, J P; Freitas, P E; Almeida, L D; Rosmaninho, M G

2017-07-01

Wastes of electrical and electronic equipment (WEEE) represent an important environmental problem, since its composition includes heavy metals and organic compounds used as flame-retardants. Thermal treatments have been considered efficient processes on removal of these compounds, producing carbonaceous structures, which, together with the ceramic components of the WEEE (i.e. silica and alumina), works as support material for the metals. This mixture, associated with the metals present in WEEE, represents promising systems with potential for catalytic application. In this work, WEEE was thermally modified to generate materials that were extensively characterized. Raman spectrum for WEEE after thermal treatment showed two carbon associated bands. SEM images showed a metal nanoparticles distribution over a polymeric and ceramic support. After characterization, WEEE materials were applied in ethanol steam reforming reaction. The system obtained at higher temperature (800°C) exhibited the best activity, since it leads to high conversions (85%), hydrogen yield (30%) and H 2 /CO ratio (3,6) at 750°C. Copyright © 2017 Elsevier Ltd. All rights reserved.

The fate or organic matter during planetary accretion - Preliminary studies of the organic chemistry of experimentally shocked Murchison meteorite

Science.gov (United States)

Tingle, Tracy N.; Tyburczy, James A.; Ahrens, Thomas J.; Becker, Christopher H.

1992-01-01

The fate of organic matter in carbonaceous meteorites during hypervelocity (1-2 km/sec) impacts is investigated using results of experiments in which three samples of the Murchison (CM2) carbonaceous chondrite were shocked to 19, 20, and 36 GPa and analyzed by highly sensitive thermal-desorption photoionization mass spectrometry (SALI). The thermal-desorptive SALI mass spectra of unshocked CM2 material revealed presence of indigenous aliphatic, aromatic, sulfur, and organosulfur compounds, and samples shocked to about 20 GPa showed little or no loss of organic matter. On the other hand, samples shocked to 36 GPa exhibited about 70 percent loss of organic material and a lower alkene/alkane ratio than did the starting material. The results suggest that it is unlikely that the indigenous organic matter in carbonaceous chondritelike planetesimals could have survived the impact on the earth in the later stages of earth's accretion.

Quantification of the carbonaceous matter origin in submicron marine aerosol particles by dual carbon isotope analysis

Science.gov (United States)

Ceburnis, D.; Garbaras, A.; Szidat, S.; Rinaldi, M.; Fahrni, S.; Perron, N.; Wacker, L.; Leinert, S.; Remeikis, V.; Facchini, M. C.; Prevot, A. S. H.; Jennings, S. G.; O'Dowd, C. D.

2011-01-01

Dual carbon isotope analysis has been performed for the first time demonstrating a potential in organic matter apportionment between three principal sources: marine, terrestrial (non-fossil) and fossil fuel due to unique isotopic signatures. The results presented here, utilising combinations of dual carbon isotope analysis, provides a conclusive evidence of a dominant biogenic organic fraction to organic aerosol over biologically active oceans. In particular, the NE Atlantic, which is also subjected to notable anthropogenic influences via pollution transport processes, was found to contain 80% organic aerosol matter of biogenic origin directly linked to plankton emissions. The remaining carbonaceous aerosol was of fossil-fuel origin. By contrast, for polluted air advecting out from Europe into the NE Atlantic, the source apportionment is 30% marine biogenic, 40% fossil fuel, and 30% continental non-fossil fuel. The dominant marine organic aerosol source in the atmosphere has significant implications for climate change feedback processes.

Zinc-stearate-layered hydroxide nanohybrid material as a precursor to produce carbon nanoparticles

International Nuclear Information System (INIS)

Ghotbi, Mohammad Yeganeh; Bagheri, Narjes; Sadrnezhaad, S.K.

2011-01-01

Research highlights: → In this work, a new organic-clay nanohybrid material, in which the organic moiety is intercalated between the inorganic layers, was synthesized using stearate anion as a guest and zinc hydroxide nitrate as an inorganic layered host by ion-exchange technique. Carbon nanoparticles were obtained by heat treating of the nanohybrid material, zinc-stearate-layered hydroxide. The proposed method is very simple, the chemicals used in the synthesis are cheap and the manner is economic and suitable for a large scale production of nano-sized carbon nanoparticles. - Abstract: Zinc-stearate-layered hydroxide nanohybrid was prepared using stearate anion as an organic guest, and zinc layered hydroxide nitrate, as a layered inorganic host by the ion-exchange method. Powder X-ray diffraction patterns and Fourier transform infrared results indicated that the stearate anion was actually intercalated into the interlayer of zinc layered hydroxide nitrate and confirmed the formation of the host-guest nanohybrid material. Also, surface properties data showed that the intercalation process has changed the porosity for the as-prepared nanohybrid material in comparison with that of the parent material, zinc hydroxide nitrate. The nanohybrid material was heat-treated at 600 deg. C under argon atmosphere. Stearate anion was chosen as a carbonaceous reservoir in the nanohybrid to produce carbon nanoparticles after heat-treating of the nanohybrid and subsequently acid washing process.

Synthesis, Characterization and Application of Multiscale Porous Materials

Energy Technology Data Exchange (ETDEWEB)

Hussami, Linda

2010-07-01

This thesis work brings fresh insights and improved understanding of nano scale materials through introducing new hybrid composites, 2D hexagonal in MCM-41 and 3D random interconnected structures of different materials, and application relevance for developing fields of science, such as fuel cells and solar cells. New types of porous materials and organometallic crystals have been prepared and characterized in detail. The porous materials have been used in several studies: as hosts to encapsulate metal-organic complexes; as catalyst supports and electrode materials in devices for alternative energy production. The utility of the new porous materials arises from their unique structural and surface chemical characteristics as demonstrated here using various experimental and theoretical approaches. New single crystal structures and arene-ligand exchange properties of f-block elements coordinated to ligand arene and halogallates are described in Paper I. These compounds have been incorporated into ordered 2D-hexagonal MCM-41 and polyhedral silica nano foam (PNF-SiO{sub 2}) matrices without significant change to the original porous architectures as described in Paper II and III. The resulting inorganic/organic hybrids exhibited enhanced luminescence activity relative to the pure crystalline complexes. A series of novel polyhedral carbon nano foams (PNF-C's) and inverse foams were prepared by nano casting from PNF-SiO{sub 2}'s. These are discussed in Paper IV. The synthesis conditions of PNF-C's were systematically varied as a function of the filling ratio of carbon precursor and their structures compared using various characterization methods. The carbonaceous porous materials were further tested in Paper V and VI as possible catalysts and catalyst supports in counter- and working electrodes for solar- and fuel cell applications

Radiation situation during underground mineral raw materials mining

International Nuclear Information System (INIS)

Ogorodnikov, B.I.

2007-01-01

One studied the content and the ratio of 4 0 K, 226 Ra, 232 Th and 238 U natural radionuclides in the ores mined in Egypt, Iran, China and Turkey. It is shown that in some ores, for example, in the carbonaceous shale mined in China, in the Iranian bauxite and turquoise Ra eq is higher than 370 Bq/kg, that is, it is higher than the value recommended by the International Scientific Committee on Radiation Effect. The Chinese bituminous shale shows high content of 226 Ra, while 226 Ra/ 232 Th concentration ratio varies between 10 and 60 in contrast to that of other numerous mineral raw materials being close to 1-3. In a number of mines one recorded high concentrations of radon (higher than 300 Bq/m 3 ). Inhalation of such an air results in the essential internal irradiation. The average annual dose equivalents for miners may be higher than the maximum permissible value equal to 20 mSv/g [ru

Preparation, characterization, Raman, and terahertz spectroscopy study on carbon nanotubes, graphene nano-sheets, and onion like carbon materials

International Nuclear Information System (INIS)

Abouelsayed, A.; Anis, Badawi; Hassaballa, Safwat; Khalil, Ahmed S.G.; Rashed, Usama M.; Eid, Kamal A.; Al-Ashkar, Emad; El hotaby, W.

2017-01-01

We present the optical properties of carbon nanotubes, graphene nanosheets, and onion like carbon (OLC) samples with different cages size in wide frequency range from 0.06 to 1650 THz. The samples were characterized by high resolution transmission electron microscope (HRTEM), Raman, and UV–Vis-IR-THz spectroscopy. The broad absorption bands centered at around 10, 3, 2.5, 1.5, and 1.8 THz for SWCNTs, MWCNTs, graphene nanosheets, large cages (OLC 1 ), and small cages (OLC 2 ) samples, respectively, are assigned to plasmon resonance due to the localization of free carriers in a finite length. For SWCNTs, both the plasmon band position and the Drude weight (D) are located at higher values as compared with MWCNTs, graphene nanosheets, and OLC sample, suggesting that the dimensionality of the system plays a major role regarding the carrier mobility of the graphene structure. The differences in the estimated values of D, the Fermi energy (E f ), and density of carriers (N) in case of OLC samples can be due to the variation in sizes of the cages and the variation of the defects in the structure of the outermost layers of cages, where each cages consist of multi-layers of graphene enclosed one into another. - Highlights: • Preparation and spectroscopic studies on carbonaceous materials were performed. • Drude-Lorentz model were used for fitting the optical conductivity spectra. • The plasmonic resonances have been observed in THz frequency range. • The charge density N has been effected by disordered of the grapheme structure. • The σ DC values is decreased in case of 2D carbonaceous materials.

Preparation, characterization, Raman, and terahertz spectroscopy study on carbon nanotubes, graphene nano-sheets, and onion like carbon materials

Energy Technology Data Exchange (ETDEWEB)

Abouelsayed, A., E-mail: as.abouelsayed@gmail.com [Spectroscopy Department, Physics Division, National Research Centre, 33 El Bohouth St. (fromer El Tahrir St.), Dokki, P.O. 12622, Giza (Egypt); Anis, Badawi [Spectroscopy Department, Physics Division, National Research Centre, 33 El Bohouth St. (fromer El Tahrir St.), Dokki, P.O. 12622, Giza (Egypt); Hassaballa, Safwat [Physics Department, Faculty of Science, Al-Azhar University, Cairo 11884 (Egypt); Khalil, Ahmed S.G. [Center for Environmental and Smart Technology, Fayoum University, Fayoum (Egypt); Egypt Nanotechnology Center, Cairo University, Giza (Egypt); Arab Academy for Science, Technology and Maritime Transport, Smart Village Campus, Giza (Egypt); Rashed, Usama M. [Physics Department, Faculty of Science, Al-Azhar University, Cairo 11884 (Egypt); Eid, Kamal A.; Al-Ashkar, Emad; El hotaby, W. [Spectroscopy Department, Physics Division, National Research Centre, 33 El Bohouth St. (fromer El Tahrir St.), Dokki, P.O. 12622, Giza (Egypt)

2017-03-01

We present the optical properties of carbon nanotubes, graphene nanosheets, and onion like carbon (OLC) samples with different cages size in wide frequency range from 0.06 to 1650 THz. The samples were characterized by high resolution transmission electron microscope (HRTEM), Raman, and UV–Vis-IR-THz spectroscopy. The broad absorption bands centered at around 10, 3, 2.5, 1.5, and 1.8 THz for SWCNTs, MWCNTs, graphene nanosheets, large cages (OLC{sub 1}), and small cages (OLC{sub 2}) samples, respectively, are assigned to plasmon resonance due to the localization of free carriers in a finite length. For SWCNTs, both the plasmon band position and the Drude weight (D) are located at higher values as compared with MWCNTs, graphene nanosheets, and OLC sample, suggesting that the dimensionality of the system plays a major role regarding the carrier mobility of the graphene structure. The differences in the estimated values of D, the Fermi energy (E{sub f}), and density of carriers (N) in case of OLC samples can be due to the variation in sizes of the cages and the variation of the defects in the structure of the outermost layers of cages, where each cages consist of multi-layers of graphene enclosed one into another. - Highlights: • Preparation and spectroscopic studies on carbonaceous materials were performed. • Drude-Lorentz model were used for fitting the optical conductivity spectra. • The plasmonic resonances have been observed in THz frequency range. • The charge density N has been effected by disordered of the grapheme structure. • The σ{sub DC} values is decreased in case of 2D carbonaceous materials.

Synthesis and Thermodynamic Studies of Physisorptive Energy Storage Materials

Science.gov (United States)

Stadie, Nicholas

Physical adsorption of hydrogen or other chemical fuels on the surface of carbonaceous materials offers a promising avenue for energy storage applications. The addition of a well-chosen sorbent material to a compressed gas tank increases the volumetric energy density of the system while still permitting fast refueling, simplicity of design, complete reversibility, high cyclability, and low overall cost of materials. While physical adsorption is most effective at temperatures below ambient, effective storage technologies are possible at room temperature and modestly high pressure. A volumetric Sieverts apparatus was designed, constructed, and commissioned to accurately measure adsorption uptake at high pressures and an appropriate thermodynamic treatment of the experimental data is presented. In Chapter 1, the problem of energy storage is introduced in the context of hydrogen as an ideal alternative fuel for future mobile vehicle applications, and with methane in mind as a near-term solution. The theory of physical adsorption that is relevant to this work is covered in Chapter 2. In-depth studies of two classes of materials are presented in the final chapters. Chapter 3 presents a study of the dissociative "hydrogen spillover" effect in the context of its viability as a practical hydrogen storage solution at room temperature. Chapters 4-5 deal with zeolite-templated carbon, an extremely high surface-area material which shows promise for hydrogen and methane storage applications. Studies of hydrogen adsorption at high pressure (Chapter 4) and anomalous thermodynamic properties of methane adsorption (Chapter 5) on ZTCs are presented. The concluding chapter discusses the impact of and possible future directions for this work.

Operation of a steam hydro-gasifier in a fluidized bed reactor

OpenAIRE

Park, Chan Seung; Norbeck, Joseph N.

2008-01-01

Carbonaceous material, which can comprise municipal waste, biomass, wood, coal, or a natural or synthetic polymer, is converted to a stream of methane and carbon monoxide rich gas by heating the carbonaceous material in a fluidized bed reactor using hydrogen, as fluidizing medium, and using steam, under reducing conditions at a temperature and pressure sufficient to generate a stream of methane and carbon monoxide rich gas but at a temperature low enough and/or at a pressure high enough to en...

Electrically conductive cellulose composite

Science.gov (United States)

Evans, Barbara R.; O'Neill, Hugh M.; Woodward, Jonathan

2010-05-04

An electrically conductive cellulose composite includes a cellulose matrix and an electrically conductive carbonaceous material incorporated into the cellulose matrix. The electrical conductivity of the cellulose composite is at least 10 .mu.S/cm at 25.degree. C. The composite can be made by incorporating the electrically conductive carbonaceous material into a culture medium with a cellulose-producing organism, such as Gluconoacetobacter hansenii. The composites can be used to form electrodes, such as for use in membrane electrode assemblies for fuel cells.

Method of forming an electrically conductive cellulose composite

Science.gov (United States)

Evans, Barbara R [Oak Ridge, TN; O'Neill, Hugh M [Knoxville, TN; Woodward, Jonathan [Ashtead, GB

2011-11-22

An electrically conductive cellulose composite includes a cellulose matrix and an electrically conductive carbonaceous material incorporated into the cellulose matrix. The electrical conductivity of the cellulose composite is at least 10 .mu.S/cm at 25.degree. C. The composite can be made by incorporating the electrically conductive carbonaceous material into a culture medium with a cellulose-producing organism, such as Gluconoacetobacter hansenii. The composites can be used to form electrodes, such as for use in membrane electrode assemblies for fuel cells.

The role of tin-promoted Pd/MWNTs via the management of carbonaceous species in selective hydrogenation of high concentration acetylene

International Nuclear Information System (INIS)

Esmaeili, Elaheh; Mortazavi, Yadollah; Khodadadi, Abbas Ali; Rashidi, Ali Morad; Rashidzadeh, Mehdi

2012-01-01

Highlights: ► Synthesis of highly active tin-promoted catalysts by polyol method for selective hydrogenation of high concentration of acetylene. ► A positive change in the catalytic activities of tin-promoted catalysts results from distinct geometric and electronic effects. ► Change in the coverage of acetylenic overlayers for different temperature regions corresponds to the change of the number of isolated adsorption sites. ► The isolated adsorption sites are responsible for the enhancement of selectivity to ethylene with increased temperatures, via the management of the carbonaceous species over the catalyst surface. - Abstract: In the present study, Pd/MWNTs are synthesized using polyol process and modified by tin as a promoter for selective hydrogenation of high concentrated acetylene feedstock. Polyol method results in highly dispersed nanoparticles with a depletion of particle size for tin-promoted Pd catalysts as characterized by TEM. Tin promoter plays a considerable role in hydrogenation of pure acetylene stream. This is attributed to formation of Pd 2 Sn structural phase, confirmed by XRD and TPR techniques, composed mainly of intermetallic species. Catalytic behavior of tin-promoted Pd catalysts is affected by geometric and electronic factors which are more pronounced in the case of Sn/Pd = 0.25. A discontinuity in Arrhenius plots for the Sn-promoted catalysts is appeared, which seems to be due to a kinetic factor as a result of change in acetylene coverage on Pd metallic ensembles at low and high temperature ranges. Higher selectivity of the catalysts to ethylene is attributed to the presence of more isolated adsorption sites on the catalyst surface originated from both intermetallic compounds confirmed by XPS and the ones formed via the carbonaceous species upon the acetylene hydrogenation reaction.

Semivolatile Particulate Organic Material Southern Africa during SAFARI 2000

Science.gov (United States)

Eatough, D. J.; Eatough, N. L.; Pang, Y.; Sizemore, S.; Kirchstetter, T. W.; Novakov, T.

2005-01-01

During August and September 2000, the University of Washington's Cloud and Aerosol Research Group (CARG) with its Convair-580 research aircraft participated in the Southern African Fire-Atmosphere Research Initiative (SAFARI) 2000 field study in southern Africa. Aboard this aircraft was a Particle Concentrator-Brigham Young University Organic Sampling System (PC-BOSS), which was used to determine semivolatile particulate material with a diffusion denuder sampler. Denuded quartz filters and sorbent beds in series were used to measure nonvolatile and semivolatile materials, respectively. Results obtained with the PC-BOSS are compared to those obtained with conventional quartz-quartz and Teflon-quartz filter pack samplers. Various 10-120 min integrated samples were collected during flights through the h e troposphere, in the atmospheric boundary layer, and in plumes from savanna fires. Significant fine particulate semivolatile organic compounds (SVOC) were found in all samples. The SVOC was not collected by conventional filter pack samplers and therefore would not have been determined in previous studies that used only filter pack samplers. The SVOC averaged 24% of the fine particulate mass in emissions from the fires and 36% of the fine particulate mass in boundary layer samples heavily impacted by aged emissions from savanna fires. Concentrations of fine particulate material in the atmospheric mixed layer heavily impacted by aged savanna frre emissions averaged 130 micrograms per cubic meter. This aerosol was 85% carbonaceous mated.

Process of pyrogenation, etc

Energy Technology Data Exchange (ETDEWEB)

Pascal, P V.H.

1949-03-31

The invention has for its object improvements relating to processes of pyrogenation of carbonaceous materials in the presence of hydrocarbon wetting agents, notably to those processes for solid fossil combustibles, which improvements consist, chiefly, in adding to the wetting agent and/or carbonaceous materials to be heated, a catalyst constituted by at least one mineral material derived from a polyvalent element such as vanadium, molybdenum, iron, manganese, nickel, cobalt, tin etc, or by a derivative of such an element, the catalyst being added in the proportions of some ten thousandths to some hundredths by weight, for example up to five hundredths.

Characterization of carbonaceous aerosols during the MINOS campaign in Crete, July–August 2001: a multi-analytical approach

Directory of Open Access Journals (Sweden)

J. Sciare

2003-01-01

Full Text Available During the major part of the Mediterranean Intensive Oxidant Study (MINOS campaign (summer 2001, Crete Isl., the Marine Boundary Layer (MBL air was influenced by long range transport of biomass burning from the northern and western part of the Black Sea. During this campaign, carbonaceous aerosols were collected on quartz filters at a Free Tropospheric (FT site, and at a MBL site together with size-resolved distribution of aerosols. Three Evolution Gas Analysis (EGA protocols have been tested in order to better characterize the collected aged biomass burning smoke: A 2-step thermal method (Cachier et al., 1989 and a thermo-optical technique using two different temperature programs. The later temperature programs are those used for IMPROVE (Interagency Monitoring of Protected Visual Environments and NIOSH 5040 (National Institute of Occupational Safety and Health. Artifacts were observed using the NIOSH temperature program and identified as interactions between carbon and dust deposited on the filter matrix at high temperature (T>550ºC under the pure helium step of the analysis. During the MINOS campaign, Black Carbon (BC and Organic Carbon (OC mass concentrations were on average respectively 1.19±0.56 and 3.62±1.08 mgC/m3 for the IMPROVE temperature program, and 1.09±0.36 and 3.75±1.24 mgC/m3 for the thermal method. Though these values compare well on average and the agreement between the Total Carbon (TC measurements sample to sample was excellent (slope=1.00, r2=0.93, n=56, important discrepancies were observed in determining BC concentrations from these two methods (average error of 33±22%. BC from the IMPROVE temperature program compared well with non-sea-salt potassium (nss-K pointing out an optical sensitivity to biomass burning. On the other hand, BC from the thermal method showed a better agreement with non-sea-salt sulfate (nss-SO4, considered as a tracer for fossil fuel combustion during the MINOS campaign. The coupling between

Selective chromogenic detection of thiol-containing biomolecules using carbonaceous nanospheres loaded with silver nanoparticles as carrier.

Science.gov (United States)

Hu, Bo; Zhao, Yang; Zhu, Hai-Zhou; Yu, Shu-Hong

2011-04-26

Thiol-containing biomolecules show strong affinity with noble metal nanostructures and could not only stably protect them but also control the self-assembly process of these special nanostructures. A highly selective and sensitive chromogenic detection method has been designed for the low and high molecular weight thiol-containing biomolecules, including cysteine, glutathione, dithiothreitol, and bovine serum albumin, using a new type of carbonaceous nanospheres loaded with silver nanoparticles (Ag NPs) as carrier. This strategy relies upon the place-exchange process between the reporter dyes on the surface of Ag NPs and the thiol groups of thiol-containing biomolecules. The concentration of biomolecules can be determined by monitoring with the fluorescence intensity of reporter dyes dispersed in solution. This new chromogenic assay method could selectively detect these biomolecules in the presence of various other amino acids and monosaccharides and even sensitively detect the thiol-containing biomolecules with different molecular weight, even including proteins.

Annual Report (fiscal 1995, No. 10) of Research Laboratory of Carbonaceous Resources Conversion Technology, Kyoto University; Kyoto Daigaku Kogakubu jushitsu tanso shigen tenkan kogaku jikken shisetsu nenpo (19995 nendo No. 10)

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-07-01

The report covers Laboratory research activities and a decision that the Laboratory, established in April 1986, will be abolished as scheduled in April 1996. Important coal-related achievements of the Laboratory include the development of a rapid pyrolytic process, studies on coal gasification, propositions for enabling coal to dissolve into general-purpose solvents and for a liquid phase oxidation process, manufacture of advanced-function carbon materials from heavy-weight carbonaceous resources (development of next-generation coke production techniques and of various element techniques for the clean use of coal), etc. As for its activities both domestic and international, the Laboratory, engaged in Education Ministry-financed high-priority scientific research projects, represented the general affairs division in a study titled 'Utilization of various energy resources,' and represented groups participating in other projects titled 'Development of new coal-gasification process' and 'Development of integral conversion process aiming at comprehensive coal utilization.' Furthermore, the Laboratory led the 'Japan-Canada cooperative scientific research relating to the development of technologies for effective coal utilization.' (NEDO)

Annual Report (fiscal 1995, No. 10) of Research Laboratory of Carbonaceous Resources Conversion Technology, Kyoto University; Kyoto Daigaku Kogakubu jushitsu tanso shigen tenkan kogaku jikken shisetsu nenpo (19995 nendo No. 10)

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-07-01

The report covers Laboratory research activities and a decision that the Laboratory, established in April 1986, will be abolished as scheduled in April 1996. Important coal-related achievements of the Laboratory include the development of a rapid pyrolytic process, studies on coal gasification, propositions for enabling coal to dissolve into general-purpose solvents and for a liquid phase oxidation process, manufacture of advanced-function carbon materials from heavy-weight carbonaceous resources (development of next-generation coke production techniques and of various element techniques for the clean use of coal), etc. As for its activities both domestic and international, the Laboratory, engaged in Education Ministry-financed high-priority scientific research projects, represented the general affairs division in a study titled 'Utilization of various energy resources,' and represented groups participating in other projects titled 'Development of new coal-gasification process' and 'Development of integral conversion process aiming at comprehensive coal utilization.' Furthermore, the Laboratory led the 'Japan-Canada cooperative scientific research relating to the development of technologies for effective coal utilization.' (NEDO)

Hydrolysis of Selected Tropical Plant Wastes Catalyzed by a Magnetic Carbonaceous Acid with Microwave

Science.gov (United States)

Su, Tong-Chao; Fang, Zhen; Zhang, Fan; Luo, Jia; Li, Xing-Kang

2015-12-01

In this study, magnetic carbonaceous acids were synthesized by pyrolysis of the homogeneous mixtures of glucose and magnetic Fe3O4 nanoparticles, and subsequent sulfonation. The synthesis conditions were optimized to obtain a catalyst with both high acid density (0.75 mmol g-1) and strong magnetism [magnetic saturation, Ms = 19.5 Am2 kg-1]. The screened catalyst (C-SO3H/Fe3O4) was used to hydrolyze ball-milled cellulose in a microwave reactor with total reducing sugar (TRS) yield of 25.3% under the best conditions at 190 °C for 3.5 h. It was cycled for at least seven times with high catalyst recovery rate (92.8%), acid density (0.63 mmol g-1) and magnetism (Ms = 12.9 Am2 kg-1), as well as high TRS yield (20.1%) from the hydrolysis of ball-milled cellulose. The catalyst was further successfully tested for the hydrolysis of tropical biomass with high TRS and glucose yields of 79.8% and 58.3% for bagasse, 47.2% and 35.6% for Jatropha hulls, as well as 54.4% and 35.8% for Plukenetia hulls.

Biomineralization-Inspired Synthesis of Cerium-Doped Carbonaceous Nanoparticles for Highly Hydroxyl Radical Scavenging Activity

Science.gov (United States)

Zou, Shenqiang; Zhu, Xiaofang; Zhang, Lirong; Guo, Fan; Zhang, Miaomiao; Tan, Youwen; Gong, Aihua; Fang, Zhengzou; Ju, Huixiang; Wu, Chaoyang; Du, Fengyi

2018-03-01

Cerium oxide nanoparticles recently have received extensive attention in biomedical applications due to their excellent anti-oxidation performance. In this study, a simple, mild, and green approach was developed to synthesize cerium-doped carbonaceous nanoparticles (Ce-doped CNPs) using bio-mineralization of bull serum albumin (BSA) as precursor. The resultant Ce-doped CNPs exhibited uniform and ultrasmall morphology with an average size of 14.7 nm. XPS and FTIR results revealed the presence of hydrophilic group on the surface of Ce-doped CNPs, which resulted in excellent dispersity in water. The CCK-8 assay demonstrated that Ce-doped CNPs possessed favorable biocompatibility and negligible cytotoxicity. Using H2O2-induced reactive oxygen species (ROS) as model, Ce-doped CNPs showed highly hydroxyl radical scavenging capability. Furthermore, flow cytometry and live-dead staining results indicated that Ce-doped CNPs protected cells from H2O2-induced damage in a dose-dependent effect, which provided a direct evidence for anti-oxidative performance. These findings suggest that Ce-doped CNPs as novel ROS scavengers may provide a potential therapeutic prospect in treating diseases associated with oxidative stress.

Investigations of processes of mixing in fabrication of carbonaceous materials and materials of silicon carbide by means of tracer technique

International Nuclear Information System (INIS)

Vagner, K.; Bruchin, F.; Ritter, I.; Grech, T.; Tsimmermann, V.; Ebert, G.

1979-01-01

A necessary condition for production of carbonic and SiC materials is providing for good mixing of liquid and solid components. Some experiments have been done by application of the method of radioactive marking of one of the components to be mixed for the purpose of investigation of the mixing process in an installation with capacity up to 2000 kg. Marking by the bromine-82 - naphthalene has been found to be suitable. The state of mixture is characterized by the homogeneity of radioactivity distribution which can be determined by measurement of gamma-radiation of series of samples. The mass of sample is from 1 to 100 g, depending on the volume of mixer. Besides it, fine distribution of components was determined by the contact autoradiography of flat surfaces of samples. The results of investigations give possibility to establish technological time of mixing, to compare different mixers and technologies of mixing as well as to determine behaviour of the mixed components. Recommendations have been developed on standardization of this method. Necessary means of radiation protection have been described [ru

Study of the carbonaceous fraction of the atmospheric aerosol in Chamonix and St Jean de Maurienne: seasonal evolutions, source and chemical characteristics; Etude de la fraction carbonee de l'aerosol atmospherique a Chamonix et St Jean de Maurienne: evolutions saisonnieres, sources et caracteristiques chimiques

Energy Technology Data Exchange (ETDEWEB)

Aymoz, G.

2005-03-15

The atmospheric aerosols play an important role in the earth climatic system. They are also at the origin of air pollution problems in urban areas. However, their influence on the global climactic change, as well as their chemical properties in urban zone, is still very poorly known. One of the main reasons to that is the lack of information on one of the major components of aerosol, the carbonaceous matter. This work focuses on a better knowledge of this particulate carbonaceous matter. This study presents measurements of carbonaceous matter (OC and EC) in aerosol (PM10) performed within the framework of the program POVA, between February 2001 and June 2003 in Chamonix and St Jean de Maurienne (French Alps). This series represents one of the first of this type for basic sites of alpine valleys, characterized by emissions located in the bottom of the valleys and strong temperature inversions in winter, limiting the dispersion of pollutants. The POVA program, centred on the study of air pollution in these valleys, was proposed following the closing of the 'Tunnel du Mont Blanc', in 1999. One of the main objectives was to evaluate the sources of pollution by particles, in particular the share due to the international heavy duty traffic. We could establish that, on the two sites and while the international heavy duty traffic was not restored in the Chamonix Valley, this source represented approximately a third of the observed mass of particles, and was at the origin of a weaker fraction of the carbonaceous matter mass. The extremely primary character of the carbonaceous matter is a remarkable specificity of our sites. The source of carbonaceous matter represented by light vehicles emissions could not be studied. Then, it appears that combustion of biomass (probably from fireplaces) plays an important role, increased in the case of low temperatures, on the levels of pollution by particles. Lastly, the potential impact of the semi-volatile matter condensation

Study of the carbonaceous fraction of the atmospheric aerosol in Chamonix and St Jean de Maurienne: seasonal evolutions, source and chemical characteristics; Etude de la fraction carbonee de l'aerosol atmospherique a Chamonix et St Jean de Maurienne: evolutions saisonnieres, sources et caracteristiques chimiques

Energy Technology Data Exchange (ETDEWEB)

Aymoz, G

2005-03-15

The atmospheric aerosols play an important role in the earth climatic system. They are also at the origin of air pollution problems in urban areas. However, their influence on the global climactic change, as well as their chemical properties in urban zone, is still very poorly known. One of the main reasons to that is the lack of information on one of the major components of aerosol, the carbonaceous matter. This work focuses on a better knowledge of this particulate carbonaceous matter. This study presents measurements of carbonaceous matter (OC and EC) in aerosol (PM10) performed within the framework of the program POVA, between February 2001 and June 2003 in Chamonix and St Jean de Maurienne (French Alps). This series represents one of the first of this type for basic sites of alpine valleys, characterized by emissions located in the bottom of the valleys and strong temperature inversions in winter, limiting the dispersion of pollutants. The POVA program, centred on the study of air pollution in these valleys, was proposed following the closing of the 'Tunnel du Mont Blanc', in 1999. One of the main objectives was to evaluate the sources of pollution by particles, in particular the share due to the international heavy duty traffic. We could establish that, on the two sites and while the international heavy duty traffic was not restored in the Chamonix Valley, this source represented approximately a third of the observed mass of particles, and was at the origin of a weaker fraction of the carbonaceous matter mass. The extremely primary character of the carbonaceous matter is a remarkable specificity of our sites. The source of carbonaceous matter represented by light vehicles emissions could not be studied. Then, it appears that combustion of biomass (probably from fireplaces) plays an important role, increased in the case of low temperatures, on the levels of pollution by particles. Lastly, the potential impact of the semi-volatile matter condensation at the low

The insoluble carbonaceous material of CM chondrites: A possible source of discrete organic compounds under hydrothermal conditions

Science.gov (United States)

Yabuta, Hikaru; Williams, Lynda B.; Cody, George D.; Alexander, Conel M. O. D.; Pizzarello, Sandra

2007-08-01

We report on the molecular analyses of the water- and solvent-soluble organic compounds released from the insoluble organic material (IOM) of the Murray meteorite upon treatment with weight-equivalent amounts of water and under conditions of elevated temperature and pressure. A varied suite of compounds was identified by gas chromatography-mass spectrometry (GC-MS). C3-C17 alkyl dicarboxylic acids and N- and O-containing hydroaromatic and aromatic compounds were found in the water extracts. The solvent extracts contained N-, O-, and S-containing aromatic compounds, a large number of their isomers and homologs, and a series of polycyclic aromatic hydrocarbons (PAHs) of up to five rings, together with noncondensed aromatic species such as substituted benzenes, biphenyl, and terphenyls as well as their substituted homologs, and hydrated PAHs. Isotopic analyses showed that residue IOMs after hydrothermal treatment had lower deuterium and 15N content than the untreated material (ΔD = -833‰ and Δ15N = -24.1) but did not differ from it in 13C composition. The effect of the hydrothermolytic release was recorded in significant differences between the NMR spectra of untreated and residue IOM. A possible relation to common precursors for the dicarboxylic acids found in the IOM and bulk extracts is discussed.

Nanostructured pseudocapacitive materials decorated 3D graphene foam electrodes for next generation supercapacitors.

Science.gov (United States)

Patil, Umakant; Lee, Su Chan; Kulkarni, Sachin; Sohn, Ji Soo; Nam, Min Sik; Han, Suhyun; Jun, Seong Chan

2015-04-28

Nowadays, advancement in performance of proficient multifarious electrode materials lies conclusively at the core of research concerning energy storage devices. To accomplish superior capacitance performance the requirements of high capacity, better cyclic stability and good rate capability can be expected from integration of electrochemical double layer capacitor based carbonaceous materials (high power density) and pseudocapacitive based metal hydroxides/oxides or conducting polymers (high energy density). The envisioned three dimensional (3D) graphene foams are predominantly advantageous to extend potential applicability by offering a large active surface area and a highly conductive continuous porous network for fast charge transfer with decoration of nanosized pseudocapacitive materials. In this article, we review the latest methodologies and performance evaluation for several 3D graphene based metal oxides/hydroxides and conducting polymer electrodes with improved electrochemical properties for next-generation supercapacitors. The most recent research advancements of our and other groups in the field of 3D graphene based electrode materials for supercapacitors are discussed. To assess the studied materials fully, a careful interpretation and rigorous scrutiny of their electrochemical characteristics is essential. Auspiciously, both nano-structuration as well as confinement of metal hydroxides/oxides and conducting polymers onto a conducting porous 3D graphene matrix play a great role in improving the performance of electrodes mainly due to: (i) active material access over large surface area with fast charge transportation; (ii) synergetic effect of electric double layer and pseudocapacitive based charge storing.

Recent Progress in Synthesis and Application of Low-Dimensional Silicon Based Anode Material for Lithium Ion Battery

Directory of Open Access Journals (Sweden)

Yuandong Sun

2017-01-01

Full Text Available Silicon is regarded as the next generation anode material for LIBs with its ultra-high theoretical capacity and abundance. Nevertheless, the severe capacity degradation resulting from the huge volume change and accumulative solid-electrolyte interphase (SEI formation hinders the silicon based anode material for further practical applications. Hence, a variety of methods have been applied to enhance electrochemical performances in terms of the electrochemical stability and rate performance of the silicon anodes such as designing nanostructured Si, combining with carbonaceous material, exploring multifunctional polymer binders, and developing artificial SEI layers. Silicon anodes with low-dimensional structures (0D, 1D, and 2D, compared with bulky silicon anodes, are strongly believed to have several advanced characteristics including larger surface area, fast electron transfer, and shortened lithium diffusion pathway as well as better accommodation with volume changes, which leads to improved electrochemical behaviors. In this review, recent progress of silicon anode synthesis methodologies generating low-dimensional structures for lithium ion batteries (LIBs applications is listed and discussed.

Antimony Anchored with Nitrogen-Doping Porous Carbon as a High-Performance Anode Material for Na-Ion Batteries.

Science.gov (United States)

Wu, Tianjing; Hou, Hongshuai; Zhang, Chenyang; Ge, Peng; Huang, Zhaodong; Jing, Mingjun; Qiu, Xiaoqing; Ji, Xiaobo

2017-08-09

Antimony represents a class of unique functional materials in sodium-ion batteries with high theoretical capacity (660 mA h g -1 ). The utilization of carbonaceous materials as a buffer layer has been considered an effective approach to alleviate rapid capacity fading. Herein, the antimony/nitrogen-doping porous carbon (Sb/NPC) composite with polyaniline nanosheets as a carbon source has been successfully achieved. In addition, our strategy involves three processes, a tunable organic polyreaction, a thermal annealing process, and a cost-effective reduction reaction. The as-prepared Sb/NPC electrode demonstrates a great reversible capacity of 529.6 mA h g -1 and an outstanding cycling stability with 97.2% capacity retention after 100 cycles at 100 mA g -1 . Even at 1600 mA g -1 , a superior rate capacity of 357 mA h g -1 can be retained. Those remarkable electrochemical performances can be ascribed to the introduction of a hierarchical porous NPC material to which tiny Sb nanoparticles of about 30 nm were well-wrapped to buffer volume expansion and improve conductivity.

GlidArc-assisted production of synthesis gas from various carbonaceous feedstocks

International Nuclear Information System (INIS)

Czernichowski, A.; Czernichowski, P.; Czernichowski, M.

2003-01-01

Pure Hydrogen or its mixture with Carbon Monoxide (called Synthesis Gas) will be massively extracted from various fossil or renewable feedstocks. Such matters contain contaminants (principally Sulphur) that make conventional catalytic reforming technologies very difficult to run without a prior deep cleaning of the feeds in order to avoid the reformer's catalyst poisoning. We propose a non-catalytic process in which almost any carbonaceous feed is converted into the Synthesis Gas in a presence of high-voltage discharges (called GlidArc) that assist the exothermic Partial Oxidation POX). The unique oxidant is air. This contribution presents some of our tests with natural gas, cyclohexane, heptane, toluene, various gasolines, and various diesel oils (including logistic ones). In two separate contributions to this Conference we present our more expanded studies on the GlidArc-assisted POX reforming of commercial propane and rapeseed oil (canola). Our reactors (1- or 2-Liter scale) work at atmospheric pressure and need less than 0.5 kW electric power (rather about 0.1 kW) to produce up to 9 m 3 (n)/h of Nitrogen-diluted SynGas containing up to 27% of H 2 and up to 23% of CO. Such assisting power represents roughly less than 5% (rather around 2%) with respect to the Lower Heating Value of produced Synthesis Gas (up to 11 kW). Recycling such relatively small portion of the power is an acceptable compromise. All tested feeds are totally reformed. No soot is observed at a sufficient O/C ratio. (author)

Factors controlling localization of uranium deposits in the Dakota Sandstone, Gallup and Ambrosia Lake mining districts, McKinley County, New Mexico

Science.gov (United States)

Pierson, Charles Thomas; Green, Morris W.

1977-01-01

Geologic studies were made at all of the uranium mines and prospects in the Dakota Sandstone of Early(?) and Late Cretaceous age in the Gallup mining district, McKinley County, New Mexico. Dakota mines in the adjacent Ambrosia Lake mining district were visited briefly for comparative purposes. Mines in the eastern part of the Gallup district, and in the Ambrosia Lake district, are on the Chaco slope of the southern San Juan Basin in strata which dip gently northward toward the central part of the basin. Mines in the western part of the Gallup district are along the Gallup hogback (Nutria monocline) in strata which dip steeply westward into the Gallup sag. Geologic factors which controlled formation of the uranium deposits in the Dakota Sandstone are: (1) a source of uranium, believed to be uranium deposits of the underlying Morrison Formation of Late Jurassic age; (2) the accessibility to the Dakota of uranium-bearing solutions from the Morrison; (3) the presence in the Dakota of permeable sandstone beds overlain by impermeable carbonaceous shale beds; and (4) the occurrence within the permeable Dakota sandstone beds of carbonaceous reducing material as bedding-plane laminae, or as pockets of carbonaceous trash. Most of the Dakota uranium deposits are found in the lower part of the formation in marginal-marine distributary-channel sandstones which were deposited in the backshore environment. However, the Hogback no. 4 (Hyde) Mine (Gallup district) occurs in sandy paludal shale of the backshore environment, and another deposit, the Silver Spur (Ambrosia Lake district), is found in what is interpreted to be a massive beach or barrier-bar sandstone of the foreshore environment in the upper part of the Dakota. The sedimentary depositional environment most favorable for the accumulation of uranium is that of backshore areas lateral to main distributary channels, where levee, splay, and some distributary-channel sandstones intertongue with gray carbonaceous shales and

Contribution of Biomass Burning to Carbonaceous Aerosols in Mexico City during may 2013

Science.gov (United States)

Tzompa Sosa, Z. A.; Sullivan, A.; Kreidenweis, S. M.

2014-12-01

The Mexico City Metropolitan Area (MCMA) is one of the largest megacities in the world with a population of 20 million people. Emissions transported from outside the basin, such as wildfires and agricultural burning, represent a potentially large contribution to air quality degradation. This study analyzed PM10 filter samples from six different stations located across the MCMA from May, 2013, which represented the month with the most reported fire counts in the region between 2002-2013. Two meteorological regimes were established considering the number of satellite derived fire counts, changes in predominant wind direction, ambient concentrations of CO, PM10 and PM2.5, and precipitation patterns inside MCMA. The filter samples were analyzed for biomass burning tracers including levoglucosan (LEV), water-soluble potassium (WSK+); and water-soluble organic carbon (WSOC). Results of these analyses show that LEV concentrations correlated positively with ambient concentrations of PM2.5 and PM10 (R2=0.61 and R2=0.46, respectively). Strong correlations were also found between WSOC and LEV (R2=0.94) and between WSK+ and LEV (R2=0.75). An average LEV/WSOC ratio of 0.0147 was estimated for Regime 1 and 0.0062 for Regime 2. Our LEV concentrations and LEV/WSOC ratios are consistent with results found during the MILAGRO campaign (March, 2006). To the best of our knowledge, only total potassium concentrations have been measured in aerosol samples from MCMA. Therefore, this is the first study in MCMA to measure ambient concentrations of WSK+. Analysis of gravimetric mass concentrations showed that PM2.5 accounted for 60% of the PM10 mass concentration with an estimated PM10/PM2.5 ratio of 1.68. Estimates from our laboratory filter sample characterization indicated that we measured 37% of the total PM10 mass concentration. The missing mass is most likely crustal material (soil or dust) and carbonaceous aerosols that were not segregated into WSOC fraction. Assuming that LEV is

Effect of iron and chromium on the graphitization behaviour of sulfur-containing carbon

International Nuclear Information System (INIS)

Tyumentsev, V.A.; Belenkov, E.A.; Saunina, S.I.; Podkopaev, S.A.; Shvejkin, G.P.

1998-01-01

Process of transition of carbonaceous material, containing structurally incorporated sulfur, into graphite and impact of iron and chromium additions are studied. It is established that carbonaceous material, containing more than 1.5 mass % S and also 1.5 mass % Cr 2 O 3 is heterogeneous after thermal treatment at 1300-1600 deg C. It consists of large and sufficiency complete areas of coherent scattering having graphite structure and ultra-dispersed matrix. The number of graphite crystals formed in the presence of dispersed iron within this temperature range, decreases by two times [ru