WorldWideScience

Sample records for carbon inorganic compounds

  1. Nomenclature on an inorganic compound

    International Nuclear Information System (INIS)

    This book contains eleven chapters : which mention nomenclature of an inorganic compound with introduction and general principle on nomenclature of compound. It gives the description of grammar for nomenclature such as brackets, diagonal line, asterisk, and affix, element, atom and groups of atom, chemical formula, naming by stoichiometry, solid, neutral molecule compound, ion, a substituent, radical and name of salt, oxo acid and anion on introduction and definition of oxo acid, coordination compound like symbol of stereochemistry , boron and hydrogen compound and related compound.

  2. Investigations on organogermanium compounds XII. Reactions of trialkylgermylalkalimetal compounds in hexamethylphosphoric triamide (HMPT) with some inorganic and organic compounds

    NARCIS (Netherlands)

    Bulten, E.J.; Noltes, J.G.

    1971-01-01

    Trialkylgermyl alkali metal compounds in HMPT have been found to be highly reactive nucleophiles. Reactions with some inorganic and organic compounds, such as oxygen, carbon dioxide, inorganic and orgaanic halides, aldehydes, ketones, epoxides and lactones are described. Several new carbon-functiona

  3. Microbiological disproportionation of inorganic sulfur compounds

    DEFF Research Database (Denmark)

    Finster, Kai

    2008-01-01

    The disproportionation of inorganic sulfur intermediates at moderate temperatures (0-80 °C) is a microbiologically catalyzed chemolithotrophic process in which compounds like elemental sulfur, thiosulfate, and sulfite serve as both electron donor and acceptor, and generate hydrogen sulfide...... and sulfate. Thus the overall process is comparable to the fermentation of organic compounds such as glucose and is consequently often described as 'inorganic fermentation'. The process is primarily carried out by microorganisms with phylogenetic affiliation to the so called sulfate-reducing bacteria within...

  4. Intercalation compounds involving inorganic layered structures

    Directory of Open Access Journals (Sweden)

    CONSTANTINO VERA R. L.

    2000-01-01

    Full Text Available Two-dimensional inorganic networks can shown intracrystalline reactivity, i.e., simple ions, large species as Keggin ions, organic species, coordination compounds or organometallics can be incorporated in the interlayer region. The host-guest interaction usually causes changes in their chemical, catalytic, electronic and optical properties. The isolation of materials with interesting properties and making use of soft chemistry routes have given rise the possibility of industrial and technological applications of these compounds. We have been using several synthetic approaches to intercalate porphyrins and phthalocyanines into inorganic materials: smectite clays, layered double hydroxides and layered niobates. The isolated materials have been characterized by elemental and thermal analysis, X-ray diffraction, surface area measurements, scanning electronic microscopy, electronic and resonance Raman spectroscopies and EPR. The degree of layer stacking and the charge density of the matrices as well their acid-base nature were considered in our studies on the interaction between the macrocycles and inorganic hosts.

  5. Modeling of cooperative properties of inorganic compounds

    International Nuclear Information System (INIS)

    When modeling cooperative phenomena, the approach based on the study of certain diamagnetodiluted compounds with increasing concentration of magnetic complexes has been realized sequentially. It has been shown that in the systems with a strong electron-phonon interaction the study of properties of isolated and interacting complexes permits a correct prediction of the structure and magnetic properties of the concentrated compounds. Examples of the study of CuL6 complexes Jahn-Teller effect in various classes of inorganic compounds by the ESR method are considered. The detection and study of the dynamic Jahn-Teller complexes in solid solutions La2-ySryAl1-xCuxO4 permitted suggesting a model dynamic structure of CuO2 basic layer in high-Tc materials

  6. Information-Analytical System for Design of New Inorganic Compounds

    OpenAIRE

    Kiselyova, Nadezhda; Stolyarenko, Andrey; Ryazanov, Vladimir; Podbel’skii, Vadim

    2008-01-01

    The principles of design of information-analytical system (IAS) intended for design of new inorganic compounds are considered. IAS includes the integrated system of databases on properties of inorganic substances and materials, the system of the programs of pattern recognition, the knowledge base and managing program. IAS allows a prediction of inorganic compounds not yet synthesized and estimation of their some properties.

  7. RIVERINE INORGANIC CARBON DYNAMICS: OVERVIEW AND PERSPECTIVE

    Institute of Scientific and Technical Information of China (English)

    YAO Guan-rong; GAO Quan-zhou

    2006-01-01

    Inorganic carbon, the great part of the riverine carbon exported to the ocean, plays an important role in the global carbon cycle and ultimately impacts the coupled carbon-climate system. An overview was made on both methods and results of the riverine inorganic carbon researches. In addition to routine in situ survey, measurement and calculation,the direct precipitation method and the gas evolution technique were commonly used to analyze dissolved inorganic carbon in natural water samples. Soil CO2, carbonate minerals and atmospheric CO2 incorporated into riverine inorganic carbon pool via different means, with bicarbonate ion being the dominant component. The concentration of inorganic carbon, the composition of carbon isotopes (δ13C and △14C), and their temporal or spatial variations in the streams were controlled by carbon input, output and changes of carbon biogeochemistry within the riverine system. More accurate flux estimation, better understanding of different influential processes, and quantitative determination of various inputs or outputs need to be well researched in future.

  8. Charting the complete elastic properties of inorganic crystalline compounds

    OpenAIRE

    de Jong, Maarten; Chen, Wei; Angsten, Thomas; Jain, Anubhav; Notestine, Randy; Gamst, Anthony; Sluiter, Marcel; Ande, Chaitanya Krishna; Zwaag, Sybrand van der; Plata, Jose J.; Toher, Cormac; Curtarolo, Stefano; Ceder, Gerbrand; Persson, Kristin A.; Asta, Mark

    2014-01-01

    The elastic constant tensor of an inorganic compound provides a complete description of the response of the material to external stresses in the elastic limit. It thus provides fundamental insight into the nature of the bonding in the material, and it is known to correlate with many mechanical properties. Despite the importance of the elastic constant tensor, it has been measured for a very small fraction of all known inorganic compounds, a situation that limits the ability of materials scien...

  9. Nomenclature of inorganic compounds. Principles and examples

    International Nuclear Information System (INIS)

    This text-book consist of eighteen parts: (1) Classification and nomenclature of elements; (2) Classification and nomenclature of chemical compounds; (3) Nomenclature systems; (4) Classification of chemical formulas; (5) Codified numerical prefixes; (6) General principles of nomenclature; (7) Binary compounds; (8) Neutral and cationic atomic groups terminated with -YL; (9) Acids; (10) Polynuclear acids; (11) Double salts and mixed forms of oxides and hydroxides; (12) Adducts; (13) Intermetallic compounds; (14) Isotopically modified compounds; (15) Coordination compounds; (16) Organometallic compounds and their derivatives; (17) Appendixes; (18) Used and recommended literature. This text-book is assigned for university students of the chemistry and related sciences.

  10. Binary systems solubilities of inorganic and organic compounds

    CERN Document Server

    Stephen, H

    1963-01-01

    Solubilities of Inorganic and Organic Compounds, Volume 1: Binary Systems, Part 1 is part of an approximately 5,500-page manual containing a selection from the International Chemical Literature on the Solubilities of Elements, Inorganic Compounds, Metallo-organic and Organic Compounds in Binary, Ternary and Multi-component Systems. A careful survey of the literature in all languages by a panel of scientists specially appointed for the task by the U.S.S.R. Academy of Sciences, Moscow, has made the compilation of this work possible. The complete English edition in five separately bound volumes w

  11. Physical and thermochemical properties for inorganic mercury compounds

    International Nuclear Information System (INIS)

    In order to estimate the radiation safety for the spallation target system using mercury, it is necessary to provide physical and thermochemical data of inorganic mercury compounds formed with elements including spallation products. The numbers of selected inorganic mercury compounds are 208 in the solid state, 9 in the liquid state and 22 in the gaseous state, respectively. This report presents main properties of the inorganic mercury compounds such as density, melting and boiling points, standard enthalpy of formation, standard Gibbs energy of formation, constant-pressure heat capacity, vapor pressure and solubility in mercury. Especially, the temperature dependency of the heat capacity was reestimated by using the Kelley equation. Vapor pressures were estimated with the Chemical Reaction and Equilibrium Software HSC using above thermochemical data. The interaction between mercury and other elements was shown in the form of binary phase diagram. (author)

  12. 75 FR 29534 - Inorganic Nitrates-Nitrite, Carbon and Carbon Dioxide, and Sulfur Registration Review; Draft...

    Science.gov (United States)

    2010-05-26

    ... AGENCY Inorganic Nitrates-Nitrite, Carbon and Carbon Dioxide, and Sulfur Registration Review; Draft... draft ecological risk assessment for the registration review of inorganic nitrates - nitrites, carbon... occur for all inorganic nitrates- nitrites, carbon and carbon dioxide uses, as well as gas...

  13. Tritium recoil reactions in inorganic solid compounds. Chapter 22

    International Nuclear Information System (INIS)

    The behavior of recoil tritium produced in inorganic solid compounds is an esoteric chapter of the already esoteric field of Hot Atom Chemistry. A very small group of investigators have devoted their attention to this problem. The author summarizes the results of their studies. (Auth.)

  14. Complexes of polyvinyl alcohol with insoluble inorganic compounds

    Science.gov (United States)

    Prosanov, I. Yu.; Bulina, N. V.; Gerasimov, K. B.

    2013-10-01

    Hybrid materials of polyvinyl alcohol-hydroxides/oxides of Be, Mg, Zn, Cd, B, Al, Cr, and Fe have been obtained. The studies have been carried out by the methods of optical spectroscopy, X-ray diffraction, and synchronous thermal analysis. Interpretation of experimental data is presented, presuming that, in systems with zinc, boron, aluminum, chromium, and iron hydroxides/oxides, interpolymeric complexes of polyvinyl alcohol with corresponding polymeric inorganic compounds are formed. They belong to a new class of materials with unusual structure containing chains of inorganic polymers isolated in the organic matrix.

  15. Survey of electrochemical production of inorganic compounds. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-10-01

    The electrochemical generation of inorganic compounds, excluding chlorine/caustic, has been critically reviewed. About 60 x 10/sup 12/ Btu/y fossil fuel equivalent will be used in the year 2000 for the electrosynthesis of inorganic compounds. Significant energy savings in chlorate production can result from the development of suitable electrocatalysts for lowering the cathodic overpotential. Perchlorates, electrolytic hypochlorite, electrolytic manganese dioxide, fluorine and other miscellaneous compounds use relatively small amounts of electrical energy. Implementation of caustic scrubber technology for stack gas cleanup would result in appreciable amounts of sodium sulfate which could be electrolyzed to regenerate caustic. Hydrogen peroxide, now produced by the alkyl anthraquinone process, could be made electrolytically by a new process coupling anodic oxidation of sulfate with cathodic reduction of oxygen in alkaline solution. Ozone is currently manufactured using energy-inefficient silent discharge equipment. A novel energy-efficient approach which uses an oxygen-enhanced anodic reaction is examined.

  16. Inorganic carbon acquisition in red tide dinoflagellates.

    Science.gov (United States)

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

    2006-05-01

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

  17. Carbon dioxide removal with inorganic membranes

    Energy Technology Data Exchange (ETDEWEB)

    Judkins, R.R.; Fain, D.E. [Oak Ridge National Laboratory, TN (United States)

    1993-12-31

    The increasing concentrations of greenhouse gases, particularly carbon dioxide, in the atmosphere has sparked a great deal of interest in the removal of CO{sub 2} from flue gases of fossil fueled plants. Presently, several techniques for the removal of CO{sub 2} are considered to have potential, but are lacking in practicality. For example, amine scrubbing of flue gas streams is potential, but are lacking in practically. For example, amine scrubbing of flue gas streams is effective in removing CO{sub 2}, but costs are high; efficiency suffers; and other acid gases must be removed prior to amine stripping. Membrane systems for CO{sub 2} removal are held in high regard, and inorganic, particularly ceramic, membranes offer the potential for high temperature, thus energy saving, removal.

  18. Tritium release from neutron irradiated lithium inorganic compounds

    International Nuclear Information System (INIS)

    Tritium release from irradiated lithium inorganic compounds Li/sub 2/O, Li/sub 2/SO/sub 4/, Li/sub 2/SiO/sub 3/, Li/sub 4/SiO/sub 4/, LiA10/sub 2/, Li/sub 2/TiO/sub 3/, LiNbO/sub 3/ was studied in isochronic and isothermal conditions in the temperature range 200-9000C. The samples were prepared by outgassing at 600-6500 in quartz ampules, sealed and then irradiated under thermal neutron flux about 1.10/sup 13/n cm/sup -2/s/sup -1/ with tritium concentration ≅3.7 10/sup 8/-3.7 10/sup 9/Bq/g. The initial stage of the tritiated water recovery from complex lithium inorganic compounds is characterized by a rapid tritium release accompanied by defect annealing and release energy accumulated by a solid state during irradiation. The two temperature ranges were observed as a result of the OT' groups formation which are in two energy states due to the formation of bonds M-O-T(H) (where M-Si, A1, Ti, Nb...) and Li-O-T(h). Symbol H emphasizes the importance of the residual content of the OH groups in the initial materials which should be considered as an inorganic polymers having the properties of solid acids and bases. The process of tritium release from irradiated lithium inorganic compounds is a many stage process including the following steps: tritium (ion) diffusion inside a crystal lattice; formation of OT groups on the surface of oxygen compounds, recombination of OT and OH groups to form a water molecule that is detected in a gas phase as a product of the annealing process

  19. Infrared and Raman spectra of inorganic and coordination compounds theory and applications in inorganic chemistry

    CERN Document Server

    Nakamoto, Kazuo

    2008-01-01

    The Sixth Edition of this classic work comprises the most comprehensive and current guide to infrared and Raman spectra of inorganic, organometallic, bioinorganic, and coordination compounds. From fundamental theories of vibrational spectroscopy to applications in a variety of compound types, this has been extensively updated. New topics include the theoretical calculations of vibrational frequencies (DFT method), chemical synthesis by matrix co-condensation reactions, time-resolved Raman spectroscopy, and more. This volume is a core reference for chemists and medical professionals working with infrared or Raman spectroscopies and an excellent textbook for graduate courses.

  20. Autonomous Sensing of Particulate Inorganic Carbon Dynamics

    Science.gov (United States)

    Weiss, G. A.; Bishop, J. K.; Strubhar, W. D.; Wood, T.

    2011-12-01

    Particulate inorganic carbon (PIC) is produced by coccolithophore phytoplankton and shelled foraminifera and pterpod microzooplankton. These calcite and aragonite particles contribute to excess density of aggregate particles enabling carbon export from surface waters; they are sensitive to the effects of ocean acidification. Concentrations in surface waters range from below 100 nM in oligotrophic waters to 40 uM in the North Atlantic. Very limited ship observations in the Oyashio and subarctic NE Pacific show short term PIC variability of more than one order of magitude over 10 days and 3 months, respectively. At depth concentrations can drop to near zero in waters deeper than the carbonate saturation horizon. Seasonal variations of a factor of two or more at 1000 m depth have been observed. Near surface variability is impossible to follow from ships. We are working on the development of a robust PIC sensor capable of deployment on platforms ranging from CTD's to floats and thus address the gap in observations. The sensor, which uses cross polarized optics, detects the photons that have interacted with birefringent minerals (of which calcite dominates) in the water column. The detection of this very weak signal - which can be 10-6 of the primary beam energy is a daunting task. Here we report results from incomparison deployments of a 'next gen' and prototype sensor during recent expeditions to California coastal and offshore waters (NE Pacific Gyre, Santa Barbara Basin (June 2009); Santa Catalina Basin (October 2010), Santa Cruz Basin (May 2011), California Current and Coastal Waters (July 2011; September 2011). In addition we report calibrations the sensors based on particulate samples filtered from 1L samples and analyzed by HR-ICP-MS.

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

    Science.gov (United States)

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

  2. Inorganic carbon acquisition in some synurophyte algae.

    Science.gov (United States)

    Bhatti, Shabana; Colman, Brian

    2008-05-01

    Some characteristics of photosynthesis of three synurophyte algae, Synura petersenii, Synura uvella and Tessellaria volvocina were investigated to determine the mechanism of inorganic carbon (C(i)) uptake. All three species were found to have no external carbonic anhydrase, no capacity for direct bicarbonate uptake and a low whole-cell affinity for C(i). The internal pH of S. petersenii determined using (14)C-benzoic acid and [2-(14)C]-5,5-dimethyloxazolidine-2,4-dione was pH 7.0-7.5, over an external pH range of 5.0-7.5. Thus, the pH difference between the cell interior of S. petersenii and the external medium was large enough, over the alga's growth range, to allow the accumulation of C(i) by the diffusive uptake of CO(2). Monitoring O(2) evolution and CO(2) uptake by suspensions of S. petersenii at pH 7.0 by mass spectrometry did not indicate a rapid uptake of CO(2), and the final CO(2) compensation concentration reached was 24 +/- 0.7 microM. Furthermore, when the cells were darkened, a brief burst of CO(2) occurred before a steady rate of dark respiration was established, suggesting a loss of CO(2) by photorespiration. An examination of the kinetics of ribulose-1,5-bisphosphate carboxylase/oxygenase in homogenates of cells of S. petersenii, S. uvella and Mallomonas papillosa showed that values of the K(m) (CO(2)) were 28.4, 41.8 and 18.2 microM, respectively. These species lack the characteristics of cells with a CO(2)-concentrating mechanism because the cell affinity for C(i) appears to be determined by the relatively high CO(2) affinity of the Rubisco of these algae. PMID:18298411

  3. Charge-density matching in organic-inorganic uranyl compounds

    International Nuclear Information System (INIS)

    Single crystals of [C10H26N2][(UO2)(SeO4)2(H2O)](H2SeO4)0.85(H2O)2 (1), [C10H26N2][(UO2)(SeO4)2] (H2SeO4)0.50(H2O) (2), and [C8H20N]2[(UO2)(SeO4)2(H2O)] (H2O) (3) were prepared by evaporation from aqueous solution of uranyl nitrate, selenic acid and the respective amines. The structures of the compounds have been solved by direct methods and structural models have been obtained. The structures of the compounds 1, 2, and 3 contain U and Se atoms in pentagonal bipyramidal and tetrahedral coordinations, respectively. The UO7 and SeO4 polyhedra polymerize by sharing common O atoms to form chains (compound 1) or sheets (compounds 2 and 3). In the structure of 1, the layers consisting of hydrogen-bonded [UO2(SeO4)2(H2O)]2- chains are separated by mixed organic-inorganic layers comprising from [NH3(CH2)10NH3]2+ molecules, H2O molecules, and disordered electroneutral (H2SeO4) groups. The structure of 2 has a similar architecture but a purely inorganic layer is represented by a fully connected [UO2(SeO4)2]2- sheet. The structure of 3 does not contain disordered (H2SeO4) groups but is based upon alternating [UO2(SeO4)2(H2O)]2- sheets and 1.5-nm-thick organic blocks consisting of positively charged protonated octylamine molecules, [NH3(CH2)7CH3]+. The structures may be considered as composed of anionic inorganic sheets (2D blocks) and cationic organic blocks self-organized according to competing hydrophilic-hydrophobic interactions. Analysis of the structures allows us to conclude that the charge-density matching principle is observed in uranyl compounds. In order to satisfy some basic peculiarities of uranyl (in general, actinyl) chemistry, it requires specific additional mechanisms: (a) in long-chain-amine-templated compounds, protonated amine molecules inter-digitate; (b) in long-chain-diamine-templated compounds, incorporation of acid-water interlayers into an organic substructure is necessary; (c) the inclination angle of the amine chains may vary in order to modify

  4. Incorporation of inorganic carbon by Antarctic cryptoendolithic fungi

    Science.gov (United States)

    Palmer, R. J. Jr; Friedmann, E. I.

    1988-01-01

    Fungi isolated from the cryptoendolithic community of the Ross Desert are capable of fixing inorganic carbon. Results suggest that lichen mycobionts and parasymbionts are adapted to different water regimes in the cryptoendolithic environment.

  5. Synthesis and properties of inorganic pigments based on pyrochlore compounds with different lanthanides

    Czech Academy of Sciences Publication Activity Database

    Stránská, L.; Šulcová, P.; Vlček, Milan

    2013-01-01

    Roč. 113, č. 1 (2013), s. 127-135. ISSN 1388-6150 Institutional support: RVO:61389013 Keywords : inorganic pigments * pyrochlore compounds * solid state reaction Subject RIV: CA - Inorganic Chemistry Impact factor: 2.206, year: 2013

  6. MANOVA statistical analysis of inorganic compounds in groundwater Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Tanty, Heruna, E-mail: herunatanty@yahoo.com [Department of Mathematics, Bina Nusantara University, Jl. K.H. Syahdan No. 9 Palmerah, Jakarta Barat (Indonesia); Bekti, Rokhana Dwi, E-mail: groo-jgroo@yahoo.com [Department of Statistics, Bina Nusantara University, Jl. K.H. Syahdan No. 9 Palmerah, Jakarta Barat (Indonesia); Herlina, Tati, E-mail: tatat-04her@yahoo.com, E-mail: nurlelasari@unpad.ac.id; Nurlelasari, E-mail: tatat-04her@yahoo.com, E-mail: nurlelasari@unpad.ac.id [Department of Chemistry, University of Padjajaran, Jl. Raya Jatinangor-Sumedang km 21, Jatinangor 45363, Jawa Barat (Indonesia)

    2014-10-24

    The present study was carried out to determine levels of inorganic compounds contained in the ground water and Reverse Osmosis (RO) water filtration result. The data in groundwater samples was collected from Bekasi, Tangerang and Jakarta in Indonesia. A total of 30 samples were collected and analyzed for the determine Cadmium (Cd), Chromium (Cr), Manganese (Mn), Cyanide (CN) and Lead (Pb). The results of the study revealed that in groundwater, the average of Cd 0.0058 mg / l, Mn 1.5233 mg / l, Cr 0.0127 mg/l, Pb 0.0060 mg / l, and CN 0.0040 mg / l. The level of RO result were: Cd 0.0027 mg / l, Mn 0.1767 mg / l, Cr 0.0024 mg / l, Pb 0.0021 mg / l, and CN 0.0023 mg / l . This means that Cd and Mn in ground water were higher than the values recommended by PAK-EPA and WHO or the standard of Indonesian Ministry of Health. But after filtration Reverse Osmosis (RO) Mn and Cd levels decreased to levels below the standardized value. By comparing of mean in MANOVA and nonparametric MANOVA in α=5%, there are differences in average levels of inorganic substances Mn, Cr, Cd, Pb, and CN between before and after RO filtration.

  7. Multifunctional slow-release organic-inorganic compound fertilizer.

    Science.gov (United States)

    Ni, Boli; Liu, Mingzhu; Lü, Shaoyu; Xie, Lihua; Wang, Yanfang

    2010-12-01

    Multifunctional slow-release organic-inorganic compound fertilizer (MSOF) has been investigated to improve fertilizer use efficiency and reduce environmental pollution derived from fertilizer overdosage. The special fertilizer is based on natural attapulgite (APT) clay used as a matrix, sodium alginate used as an inner coating and sodium alginate-g-poly(acrylic acid-co-acrylamide)/humic acid (SA-g-P(AA-co-AM)/HA) superabsorbent polymer used as an outer coating. The coated multielement compound fertilizer granules were produced in a pan granulator, and the diameter of the prills was in the range of 2.5-3.5 mm. The structural and chemical characteristics of the product, as well as its efficiency in slowing the nutrients release, were examined. In addition, a mathematical model for nutrient release from the fertilizer was applied to calculate the diffusion coefficient D of nutrients in MSOF. The degradation of the SA-g-P(AA-co-AM)/HA coating was assessed by examining the weight loss with incubation time in soil. It is demonstrated that the product prepared by a simple route with good slow-release property may be expected to have wide potential applications in modern agriculture and horticulture. PMID:21058723

  8. Safe recycling of materials containing persistent inorganic and carbon nanoparticles

    NARCIS (Netherlands)

    L. Reijnders

    2014-01-01

    For persistent inorganic and carbon nanomaterials, considerable scope exists for a form of recycling called ‘resource cascading’. Resource cascading is aimed at the maximum exploitation of quality and service time of natural resources. Options for resource cascading include engineered nanomaterials

  9. Modeling skills of pre-service chemistry teachers in predicting the structure and properties of inorganic chemistry compounds

    Science.gov (United States)

    Nursa'adah, Euis; Liliasari, Mudzakir, Ahmad

    2016-02-01

    The focus of chemistry is learning about the composition, properties, and transformations of matters. Modeling skills are required to comprehend structure and chemical composition in submicroscopic size. Modeling skills are abilities to produce chemical structure and to explain it into the macroscopic phenomenon and submicroscopic representations. Inorganic chemistry is a study of whole elements in the periodic table and their compounds, except carbon compounds and their derivatives. Knowledge about the structure and properties of chemical substances is a basic model for students in studying inorganic chemistry. Furthermore, students can design and produce to utilize materials needed in their life. This research aimed to describes modeling skills of pre-service chemistry teachers. In order, they are able to determine and synthesize useful materials. The results show that students' modeling skills were in a low level and unable connecting skill categories, even the models of inorganic compounds common. These phenomena indicated that students only describe each element when they learn inorganic chemistry. So that it will make modeling skills of students low. Later, another researches are necessary to develop learning design of inorganic chemistry based on good modeling skills of students.

  10. Oxidation of inorganic sulfur compounds in acidophilic prokaryotes

    Energy Technology Data Exchange (ETDEWEB)

    Rohwerder, T.; Sand, W. [Universitaet Duisburg-Essen, Biofilm Centre, Aquatic Biotechnology, Duisburg (Germany)

    2007-07-15

    The oxidation of reduced inorganic sulfur compounds to sulfuric acid is of great importance for biohydrometallurgical technologies as well as the formation of acidic (below pH 3) and often heavy metal-contaminated environments. The use of elemental sulfur as an electron donor is the predominant energy-yielding process in acidic natural sulfur-rich biotopes but also at mining sites containing sulfidic ores. Contrary to its significant role in the global sulfur cycle and its biotechnological importance, the microbial fundamentals of acidophilic sulfur oxidation are only incompletely understood. Besides giving an overview of sulfur-oxidizing acidophiles, this review describes the so far known enzymatic reactions related to elemental sulfur oxidation in acidophilic bacteria and archaea. Although generally similar reactions are employed in both prokaryotic groups, the stoichiometry of the key enzymes is different. Bacteria oxidize elemental sulfur by a sulfur dioxygenase to sulfite whereas in archaea, a sulfur oxygenase reductase is used forming equal amounts of sulfide and sulfite. In both cases, the activation mechanism of elemental sulfur is not known but highly reactive linear sulfur forms are assumed to be the actual substrate. Inhibition as well as promotion of these biochemical steps is highly relevant in bioleaching operations. An efficient oxidation can prevent the formation of passivating sulfur layers. In other cases, a specific inhibition of sulfur biooxidation may be beneficial for reducing cooling and neutralization costs. In conclusion, the demand for a better knowledge of the biochemistry of sulfur-oxidizing acidophiles is underlined. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  11. Bony fish and their contribution to marine inorganic carbon cycling

    Science.gov (United States)

    Salter, Michael; Perry, Chris; Wilson, Rod; Harborne, Alistair

    2016-04-01

    Conventional understanding of the marine inorganic carbon cycle holds that CaCO3 (mostly as low Mg-calcite and aragonite) precipitates in the upper reaches of the ocean and sinks to a point where it either dissolves or is deposited as sediment. Thus, it plays a key role controlling the distribution of DIC in the oceans and in regulating their capacity to absorb atmospheric CO2. However, several aspects of this cycle remain poorly understood and have long perplexed oceanographers, such as the positive alkalinity anomaly observed in the upper water column of many of the world's oceans, above the aragonite and calcite saturation horizons. This anomaly would be explained by extensive dissolution of a carbonate phase more soluble than low Mg-calcite or aragonite, but major sources for such phases remain elusive. Here we highlight marine bony fish as a potentially important primary source of this 'missing' high-solubility CaCO3. Precipitation of CaCO3 takes place within the intestines of all marine bony fish as part of their normal physiological functioning, and global production models suggest it could account for up to 45 % of total new marine CaCO3 production. Moreover, high Mg-calcite containing >25 % mol% MgCO3 - a more soluble phase than aragonite - is a major component of these precipitates. Thus, fish CaCO3 may at least partially explain the alkalinity anomaly in the upper water column. However, the issue is complicated by the fact that carbonate mineralogy actually varies among fish species, with high Mg-calcite (HMC), low Mg-calcite (LMC), aragonite, and amorphous calcium carbonate (ACC) all being common products. Using data from 22 Caribbean fish species, we have generated a novel production model that resolves phase proportions. We evaluate the preservation/dissolution potential of these phases and consider potential implications for marine inorganic carbon cycling. In addition, we consider the dramatic changes in fish biomass structure that have resulted

  12. Binary systems solubilities of inorganic and organic compounds, v.1 pt.2

    CERN Document Server

    Stephen, H

    2013-01-01

    Solubilities of Inorganic and Organic Compounds, Volume 1: Binary Systems, Part 1 is part of an approximately 5,500-page manual containing a selection from the International Chemical Literature on the Solubilities of Elements, Inorganic Compounds, Metallo-organic and Organic Compounds in Binary, Ternary and Multi-component Systems. A careful survey of the literature in all languages by a panel of scientists specially appointed for the task by the U.S.S.R. Academy of Sciences, Moscow, has made the compilation of this work possible. The complete English edition in five separately bound volumes w

  13. Photophysics of Carbon Nanotubes Interfaced with Organic and Inorganic Materials

    CERN Document Server

    Levitsky, Igor A; Karachevtsev, Victor A

    2012-01-01

    Photophysics of Carbon Nanotubes Interfaced with Organic and Inorganic Materials describes physical, optical and spectroscopic properties of the emerging class of nanocomposites formed from carbon nanotubes (CNTs)  interfacing with organic and inorganic materials. The three main chapters detail novel trends in  photophysics related to the interaction of  light with various carbon nanotube composites from relatively simple CNT/small molecule assemblies to complex hybrids such as CNT/Si and CNT/DNA nanostructures.   The latest experimental results are followed up with detailed discussions and scientific and technological perspectives to provide a through coverage of major topics including: ·   Light harvesting, energy conversion, photoinduced charge separation  and transport  in CNT based nanohybrids · CNT/polymer composites exhibiting photoactuation; and ·         Optical  spectroscopy  and structure of CNT/DNA complexes. Including original data and a short review of recent research, Phot...

  14. Epitaxial Relationships between Calcium Carbonate and Inorganic Substrates

    Directory of Open Access Journals (Sweden)

    Taewook Yang

    2014-09-01

    Full Text Available The polymorph-selective crystallization of calcium carbonate has been studied in terms of epitaxial relationship between the inorganic substrates and the aragonite/calcite polymorphs with implication in bioinspired mineralization. EpiCalc software was employed to assess the previously published experimental results on two different groups of inorganic substrates: aragonitic carbonate crystals (SrCO3, PbCO3, and BaCO3 and a hexagonal crystal family (α-Al2O3, α-SiO2, and LiNbO3. The maximum size of the overlayer (aragonite or calcite was calculated for each substrate based on a threshold value of the dimensionless potential to estimate the relative nucleation preference of the polymorphs of calcium carbonate. The results were in good agreement with previous experimental observations, although stereochemical effects between the overlayer and substrate should be separately considered when existed. In assessing the polymorph-selective nucleation, the current method appeared to provide a better tool than the oversimplified mismatch parameters without invoking time-consuming molecular simulation.

  15. Electrosorption of inorganic salts from aqueous solution using carbon aerogels.

    Science.gov (United States)

    Gabelich, Christopher J; Tran, Tri D; Suffet, I H Mel

    2002-07-01

    Capacitive deionization (CDI) with carbon aerogels has been shown to remove various inorganic species from aqueous solutions, though no studies have shown the electrosorption behavior of multisolute systems in which ions compete for limited surface area. Several experiments were conducted to determine the ion removal capacity and selectivity of carbon aerogel electrodes, using both laboratory and natural waters. Although carbon aerogel electrodes have been treated as electrical double-layer capacitors, this study showed that ion sorption followed a Langmuir isotherm, indicating monolayer adsorption. The sorption capacity of carbon aerogel electrodes was approximately 1.0-2.0 x 10(-4) equiv/g aerogel, with ion selectivity being based on ionic hydrated radius. Monovalent ions (e.g., sodium) with smaller hydrated radii were preferentially removed from solution over multivalent ions (e.g., calcium) on a percent or molar basis. Because of the relatively small average pore size (4-9 nm) of the carbon aerogel material, only 14-42 m2/g aerogel surface area was available for ion sorption. Natural organic matter may foul the aerogel surface and limit CDI effectiveness in treating natural waters. PMID:12144279

  16. Application of Artificial Neural Networks in Differential Thermal Analysis of Inorganic Compounds

    Science.gov (United States)

    Ilgun, Ozlem; Beken, Murat; Alekberov, Vilayet; Ozcanli, Yesim

    2010-01-01

    Thermal decomposition of inorganic compounds have been analyzed by simultaneous differential thermal analysis (DTA) method. Also phase transitions and critical points have been investigated. Additionally a computer model based on backpropagation multilayer feed-forward artificial neural networks (ANNs) have been used for the stimulation and prediction of critical points and phase transitions of inorganic compounds. Experimental data and output values of artificial neural networks have been compared and ANN predictions showed a considerably good result due to some unjustified data values and ANN predictions concurred with each other.

  17. CHARACTERIZATION OF RADIATION GRAFT COPOLYMER OF INORGANIC COMPOUND ONTO ALKENE

    Institute of Scientific and Technical Information of China (English)

    ZhangWanxi; CheJitai; 等

    1995-01-01

    In this paper,the radiation graft copolymer of MgO,SiO2 and Y-molecular sieve onto organic compounds,such as methacrylate,styrene and acrylomitrile obtained by per-radiation method were characterized by X-ray diffraction,pyrolysis gas chromatography,GPC and X-ray photoelectron spectroscopy.

  18. Cybernetic prediction of inorganic compounds and its correlation with experiment

    International Nuclear Information System (INIS)

    Using known experimental examples and data on chemical elements, an approach was proposed, based on computer learning, to establish the regularities and to predict the character of interaction of components of physico-chemical systems of the type AB, A2B, and A3B. A review is given of the predicted compounds and phases in order to demonstrate the applicability of the method

  19. Some Reactions of Recoil Atoms in Solid Inorganic Phosphorus Compounds

    International Nuclear Information System (INIS)

    In connection with our interest in the recoil chemistry of radiophosphorus it was considered worthwhile to investigate systems in which tritium recoils can be produced and subsequently react with inorganic anions of phosphorus. One purpose of this investigation was to evaluate the possibility for tritium recoils to replace (''displace'') either an oxygen or a hydrogen atom bound to phosphorus. For instance, oxygen replacement in an orthophosphate ion (PO4)-3 could lead to a (TPO3)-2 ion (phosphite), hydrogen replacement in hypophosphite could lead to (HTPO2). A number of lithium salts of orthophosphoric, phosphorous and hypophosphorous acid were irradiated with neutrons, the nuclear reaction Li6 (n, α)H3 serving as the source for the energetic tritium atoms. Through a step-wise oxidation procedure tritium bound to phosphorus was converted into HTO and radio-assayed by means of liquid scintillation counting. The results indicate that replacement of oxygen by tritium in orthophosphates is highly unlikely. When phosphites and hypophosphites are the target material, an appreciable percentage of the tritium recoils end up bound to phosphorus. The second purpose of this investigation was to determine to what extent the labelling of the tripolyphosphate - P32 anion, formed by recoiling P32 particles in a number of crystalline phosphates, deviates from a uniform distribution. A number of phosphates were irradiated with neutrons. The tripolyphosphate - P32 formed was separated by precipitation as the tris (ethylenediamine) cobalt (III) salt. By means of a step-wise degradation into orthophosphate the distribution of the P32 among the two possible positions in the anion was measured. One result of this study is that when anhydrous orthophosphates are the target material, there is as predicted, a strong preference for the tripolyphosphate - P32 formed to be labelled at the centre. These and other results are discussed in the light of current concepts of ''hot

  20. Seafloor Weathering Dependence on Temperature and Dissolved Inorganic Carbon

    Science.gov (United States)

    Abbot, D. S.; Farahat, N. X.; Archer, D. E.

    2015-12-01

    Most thinking on Earth's carbon cycle implicates silicate weathering as the dominant control of atmospheric CO2 concentration over long timescales. Recent analyses of alteration of basalt at the seafloor, however, suggest that seafloor weathering (low-temperature (type of weathering available on an exoplanet entirely covered by water, so understanding how it might work is essential for understanding the habitable zones of such waterworlds. We have built a 2D numerical model of the flow of seawater through porous basalt coupled to chemical alteration reactions that can calculate alkalinity fluxes and carbonate deposition (seafloor weathering). I will present simulations in which we vary the seawater temperature and dissolved inorganic carbon concentration, which are boundary conditions to our model, over large ranges. These results will provide a constraint on the ability of seafloor weathering to act as an effective climate buffer on Earth and other planets. I can't give you a preview of the results yet because at the time of writing this abstract we haven't completed the simulations!

  1. Nomenclature and spelling rules of chemistry in Hungary Pt. 1 Nomenclature of elements and inorganic compounds

    International Nuclear Information System (INIS)

    The part of the updated edition of 'Nomenclature and spelling rules of chemistry in Hungary' (Budapest, 1972), referring to the isotopically modified inorganic compounds is presented. The rules are based on the proposals of IUPAC (1981). Spelling rules concerning the isotopically substituted, isotopically labelled, specifically labelled, selectively and non-selectively labelled compounds, and the positional and numbering rules of nuclides are treated. (Sz.J.)

  2. Sulfur Isotope Exchange between S-35 Labeled Inorganic Sulfur-Compounds in Anoxic Marine-Sediments

    DEFF Research Database (Denmark)

    FOSSING, H.; THODEANDERSEN, S.; JØRGENSEN, BB

    1992-01-01

    of isotope exchange, specific radioactivities of the reduced sulfur pools were poorly defined and could not be used to calculate their rates of formation. Such isotope exchange reactions between the reduced inorganic sulfur compounds will affect the stable isotope distribution and are expected to decrease...

  3. A golden future in medicinal inorganic chemistry : The promise of anticancer gold organometallic compounds

    NARCIS (Netherlands)

    Bertrand, B.; Casini, A.

    2014-01-01

    From wedding rings on fingers to stained glass windows, by way of Olympic medals, gold has been highly prized for millennia. Nowadays, organometallic gold compounds occupy an important place in the field of medicinal inorganic chemistry due to their unique chemical properties with respect to gold co

  4. Moessbauer spectroscopic study on inorganic compounds. Pt. 2

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Masashi; Kitazawa, Takafumi; Nanba, Hiroshi; Yoshinaga, Tomohiro; Nakajima, Norio; Sumisawa, Yasuhiro; Takeda, Masuo [Toho Univ., Funabashi, Chiba (Japan). Faculty of Science; Sawahata, Hiroyuki; Ito, Yasuo

    1998-01-01

    {sup 166}Er and {sup 127}I Moessbauer spectra were observed. {sup 166}Er Moessbauer spectrum of Er metal and 9 compounds were measured by {sup 166}Ho/Y{sub 0.6}Ho{sub 0.4}H{sub 2} source at 12K and the parameters such as e{sup 2}qQ(mm s{sup -1}), Heff(T) and {tau}(ns) were determined. The relaxation time of ErCl{sub 3}{center_dot}6H{sub 2}O was 0.7ns, long, but that of ErCl{sub 3} was 10 ps, short time. {sup 127}I Moessbauer spectrum of PhI(O{sub 2}CR){sub 2} (R=CH{sub 3}, CHF{sub 2}, CH{sub 2}Cl, CHCl{sub 2}, CCl{sub 3}, CH{sub 2}Br, CHBr{sub 2} and CBr{sub 3}) were observed and compared with that of R`{sub 3}Sb(O{sub 2}CR){sub 2} was similar to that of PhI(O{sub 2}CR){sub 2}. The correlation coefficient between e{sup 2}qQ({sup 127}I) and Mulliken population of carboxylic hydrogen atom of R{sub 2}CO{sub 2}H was -0.87. The relation between the hypervalent bond of O-I-O and that of O-Sb-0 was shown by the equation: e{sup 2}qQ({sup 121}Sb)/mm s{sup -1} = -47.2 + 1.32 e{sup 2}qQ({sup 127}I)/mm s{sup -1}. Hypervalent iodine complex such as (PhI(py){sub 2}){sup 2+} salt and E-Sb-I (E=O, I, N and C) were studied, too. (S.Y.)

  5. Topological Research on Standard Absolute Entropies,S(○)298, for Binary Inorganic Compounds

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    For predicting the standard entropy of a binary inorganic compound, two novel connectivity indexes mQ,mG and their converse indexes mQ',mG' based on adjacency matrix of molecular graphs and ionic parameters gi, qi were pro-posed. The qi and gi are defined as qi=(1.1+Zi1.1)/(1.7+ni), gi:(1.4d-Zi)/(0.9+ri+ri-1), where Zi, ni, ri are the charge numbers, the outer electronic shell primary quantum numbers, and the radii of ionic I respectively. The good Quantitative Structure-Property Relationship (QSPR) models for the standard entropies of binary inorganic com-pound can be constructed from 0Q,0Q',1G, and 1G', by using a multivariate linear regression (MLR) method and an artificial neural network (NN) method. The correlation coefficient r, the standard error s, and the average absolute deviation of the MLR model and the NN model are 0.9905, 8.29 J·K-1,mol-1 and 6.48 J·K-1·mol-1, and 0.9960,5.37 J·K-1·mol-1 and 3.90 J·K-1·mol-1, respectively, for 371 binary inorganic compounds (training set). The cross-validation by using the leave-one-out method demonstrates that the MLR model is highly reliable from the point of view of statistics. The correlation coefficients, standard deviations and average absolute deviations of pre-dicted values of the standard entropies of other 185 binary inorganic compounds (test set) are 0.9897, 8.64 J·K-1·mol-1 and 6.84 J·K-1·mol-1, and 0.9957, 5.63 J·K-1·mol-1 and 4.18 J·K-1·mol-1 for the MLR model and the Nnmodel, respectively. The results show that the current method is more effective than literature methods for estimat-ing the standard entropy of a binary inorganic compound. Both MLR and NN methods can provide acceptable mod-els for the prediction of the standard entropies of binary inorganic compounds. The NN model for the standard en-tropies appears to be more reliable than the MLR model.

  6. Bioengineering aspects of inorganic carbon supply to mass algal cultures. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, J.C.

    1980-06-01

    The work included in this report is part of an ongoing study (currently funded by the Solar Energy Research Institute - Subcontract No. XR-9-8144-1) on the inorganic carbon requirements of microalgae under mass culture conditions and covers the period June 1, 1978 through May 31, 1979. It is divided into two parts appended herein. The first part is a literature review on the inorganic carbon chemical system in relation to algal growth requirements, and the second part deals with the kinetics of inorganic carbon-limited growth of two freshwater chlorophytes including the effect of carbon limitation on cellular chemical composition. Additional experiment research covered under this contract was reported in the Proceedings of the 3rd Annual Biomass Energy Systems Conferences, pp. 25-32, Bioengineering aspects of inorganic carbon supply to mass algal cultures. Report No. SERI/TP-33-285.

  7. Inorganic sulfur–nitrogen compounds: from gunpowder chemistry to the forefront of biological signaling

    OpenAIRE

    Miriam M. Cortese-Krott; Butler, Anthony R; Woollins, J. Derek; Feelisch, Martin

    2016-01-01

    The reactions between inorganic sulfur and nitrogen-bearing compounds to form S–N containing species have a long history and, besides assuming importance in industrial synthetic processes, are of relevance to microbial metabolism; waste water treatment; aquatic, soil and atmospheric chemistry; and combustion processes. The recent discovery that hydrogen sulfide and nitric oxide exert often similar, sometimes mutually dependent effects in a variety of biological systems, and that the chemical ...

  8. Inorganic elements and organic compounds degradation studies by gamma irradiation in used lubricating oils

    International Nuclear Information System (INIS)

    The automotive lubricating oils have partial degradation of organic compounds and addition of undesirable inorganic elements, during its use. These substances classify the used lubricating oils as dangerous and highly toxic. According to global consensus, concerning the environmental conservation, the best is to perform a reuse treatment of these lubricating oils. For this purpose, the uses of an alternative and effective technology have been sought. In this work, the efficacy and technical feasibility of the advanced oxidation process (AOP), by gamma radiation, for used automotive lubricating oil treatment has been studied. Different quantities of hydrogen peroxide and water Milli-Q were added to oil samples. They were submitted to the Cobalt-60 irradiator, type Gammacell, with 100, 200 and 500 kGy absorbed doses. The inorganic analysis by X-ray fluorescence (WDXRF) showed inorganic elements removal, mainly to sulphur, calcium, iron and nickel elements at acceptable levels by environmental protection law for oils reusing. The gas chromatography (GC/MS) analysis showed that the advanced oxidation process promotes the organic compounds degradation. The main identified compounds were tridecane, 2-methyl-naphthalene, and trietilamina-tetramethyl urea, which have important industrial applications. The multivariate analysis, Cluster Analysis, showed that advanced oxidation process application is a viable and promising treatment for used lubricating oil reusing. (author)

  9. Inorganic membranes for carbon capture and power generation

    Science.gov (United States)

    Snider, Matthew T.

    Inorganic membranes are under consideration for cost-effective reductions of carbon emissions from coal-fired power plants, both in the capture of pollutants post-firing and in the direct electrochemical conversion of coal-derived fuels for improved plant efficiency. The suitability of inorganic membrane materials for these purposes stems as much from thermal and chemical stability in coal plant operating conditions as from high performance in gas separations and power generation. Hydrophilic, micro-porous zeolite membrane structures are attractive for separating CO2 from N2 in gaseous waste streams due to the attraction of CO2 to the membrane surface and micropore walls that gives the advantage to CO2 transport. Recent studies have indicated that retention of the templating agent used in zeolite synthesis can further block N2 from the micropore interior and significantly improve CO2/N2 selectivity. However, the role of the templating agent in micro-porous transport has not been well investigated. In this work, gas sorption studies were conducted by high-pressure thermo-gravimetric analysis on Zeolite Y membrane materials to quantify the effect of the templating agent on CO2, N2, and H2O adsorption/desorption, as well as to examine the effect of humidification on overall membrane performance. In equilibrium conditions, the N2 sorption enthalpy was nearly unchanged by the presence of the templating agent, but the N2 pore occupation was reduced ˜1000x. Thus, the steric nature of the blocking of N2 from the micropores by the templating agent was confirmed. CO2 and H2O sorption enthalpies were similarly unaffected by the templating agent, and the micropore occupations were only reduced as much as the void volume taken up by the templating agent. Thus, the steric blocking effect did not occur for molecules more strongly attracted to the micropore walls. Additionally, in time-transient measurements the CO 2 and H2O mobilities were significantly enhanced by the presence

  10. Development of conjugate methods with gas chromatography for inorganic compounds analysis

    International Nuclear Information System (INIS)

    The application of gas chromatography combined with mass spectrometry or with nuclear methods for the analysis of inorganic compounds is studied. The advantages of the use of a gas chromatograph coupled with a quadrupole mass spectrometer or with a high resolution radiation detector, are discussed. We also studied the formation and solvent extraction of metal chelates; an aliquot of the organic phase was directly injected into the gas chromatograph and the eluted compounds were detected by mass spectrometry or, when radioactive, by nuclear methods. (author)

  11. High temperature phase change materials based on inorganic salts and carbon nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Dong; Zhang, Tao; Zeng, Liang; Zhou, Cunyu [Tongji Univ., Shanghai (China). School of Materials Science and Engineering

    2010-07-01

    High temperature phase change material is useful for solar thermal power generation, industrial process heat and waste heat recovery. In this paper, inorganic salts and carbon nanomaterials, such as expanded graphite (EG) carbon nanotube and graphene, are used to prepare high temperature phase change material. Inorganic salt/EG/7carbon nanotube/Graphene composites as phase change materials are prepared by aqueous solution method. The influence of EG, carbon nanotube and graphene on the termal conductivity of composites is studied by MDSC. Results show that expanded graphite, carbon nanotube and graphene can significantly increase the thermal conductivity of high temperature phase change materials. (orig.)

  12. A simple, gravimetric method to quantify inorganic carbon in calcareous soils

    Science.gov (United States)

    Total carbon (TC) in calcareous soils has two components: inorganic carbon (IC) as calcite and or dolomite and organic carbon (OC) in the soil organic matter. The IC must be measured and subtracted from TC to obtain OC. Our objective was to develop a simple gravimetric technique to quantify IC. Th...

  13. Determination of total dissolved inorganic carbon in freshwaters by reagent-free ion chromatography.

    Science.gov (United States)

    Polesello, Stefano; Tartari, Gabriele; Giacomotti, Paola; Mosello, Rosario; Cavalli, Silvano

    2006-06-16

    Studies of inorganic carbon cycle in natural waters provide important information on the biological productivity and buffer capacity. Determination of total inorganic carbon, alkalinity and dissolved carbon dioxide gives an indication of the balance between photosynthesis and respiration by biota, both within the water column and sediments, and carbon dioxide transfers from the water column to the atmosphere. There are few methods to measure and distinguish the different forms of inorganic carbon, but all require a measure or an indirect quantification of total inorganic carbon. A direct measurement of TIC in water is made possible by the introduction of electrolytic generated hydroxide eluent in ion chromatography which allows to detect a chromatographic peak for carbonate. The advantage of this method is that all the inorganic forms of carbon are converted in carbonate at eluent pH and can be detected as a single peak by conductivity detection. Repeatability of carbonate peak was evaluated at different levels from 0.02 to 6 mequiv.l(-1) both in high purity water and in real samples and ranged from 1 to 9%. The calibration curve was not linear and has to be fitted by a quadratic curve. Limit of detection was estimated to be 0.02 mequiv.l(-1). Accuracy has been estimated by comparing ion chromatography method with total inorganic carbon calculated from alkalinity and pH. The correlation between the two methods was good (R(2)=0.978, n=141). The IC method has been applied to different typologies of surface waters (alpine and subalpine lakes and rivers) characterised by different chemical characteristics (alkalinity from 0.05 to 2 mequiv.l(-1) and pH from 6.7 to 8.5) and low total organic carbon concentrations. This analytical method allowed to describe the distribution of TIC along the water column of two Italian deep lakes. PMID:16620857

  14. Carbon uptake in low dissolved inorganic carbon environments: the effect of limited carbon availability on photosynthetic organisms in thermal waters

    Science.gov (United States)

    Myers, K. D.; Omelon, C. R.; Bennett, P.

    2010-12-01

    Photosynthesis is the primary carbon fixation process in thermal waters below 70°C, but some hydrothermal waters have extremely low dissolved inorganic carbon (DIC), potentially limiting the growth of inorganic carbon fixing organisms such as algae and cyanobacteria. To address the issue of how carbon is assimilated by phototrophs in these environments, we conducted experiments to compare inorganic carbon uptake mechanisms by two phylogenetically distinct organisms collected from geographically distinct carbon limited systems: the neutral pH geothermal waters of El Tatio, Chile, and the acidic geothermal waters of Tantalus Creek in Norris Geyser Basin, Yellowstone National Park. Discharge waters at El Tatio have low total DIC concentrations (2 to 6 ppm) found mainly as HCO3-; this is in contrast to even lower measured DIC values in Tantalus Creek (as low as 0.13 ppm) that, due to a measured pH of 2.5, exists primarily as CO2. Cyanobacteria and algae are innately physiologically plastic, and we are looking to explore the possibility that carbon limitation in these environments is extreme enough to challenge that plasticity and lead to a suite of carbon uptake adaptations. We hypothesize that these microorganisms utilize adaptive modes of Ci uptake that allow them to survive under these limiting conditions. Cyanobacteria (primarily Synechococcus spp.) isolated from El Tatio can utilize either passive CO2 uptake or active HCO3- uptake mechanisms, in contrast to the eukaryotic alga Cyanidium spp. from Tantalus Creek, which is restricted to an energy-dependent CO2 uptake mechanism. To test this hypothesis, we conducted pH drift experiments (Omelon et al., 2008) to examine changes in pH and [DIC] under a range of pH and [DIC] culture conditions. This work provides baseline information upon which we will begin to investigate the effects of low [DIC] on the growth of phototrophs collected from these and other less carbon limited systems.

  15. Common Inorganic Salts Catalyze the Transformations of Organic Compounds in Atmospheric Aerosols

    Science.gov (United States)

    Noziere, B.; Dziedzic, P.; Cordova, A.

    2008-12-01

    This presentation reports the discovery that inorganic salts that are ubiquitous in atmospheric aerosols are efficient catalysts for the transformations of organic compounds in these aerosols, by reactions such as aldol condensation or acetal formation.1 For some of these salts, these catalytic properties were not even known in chemistry.2 Kinetic and product studies of these reactions will be presented for carbonyl compounds such as acetaldehyde, acetone, and glyoxal,1,3 and compared with previously known catalysts such as the recently discovered amino acids.4,5 These studies show that these salts make the reactions as fast in typical tropospheric aerosols as in concentrated sulfuric acid. These reactions produce secondary "fulvic" compounds that absorb light in the near UV and visible and would affect the optical properties of aerosols.1,5 They would also account for the depletion of glyoxal recently reported in Mexico city.3 Thus, while acid catalysis is several orders of magnitudes too slow to be significant in tropospheric aerosols, this work identifies new processes that should be ubiquitous in these aerosols and important for atmospheric chemistry. Refs. 1Noziere, B., Dziedzic, P., Cordova, A., Common inorganic ions catalyze chemical reactions of organic compounds in atmospheric aerosols, Submitted, 2008. 2 Noziere, B., Cordova, A., A novel catalyst for aldol condensation reaction, patent pending 02/10/2007. 3Noziere, B., Dziedzic, P., Cordova, A., Products and kinetics of the liquid-phase reaction of glyoxal catalyzed by inorganic ions, Submitted to J. Phys. Chem. A, 2008. 4Noziere, B., and Cordova, A., A Kinetic and Mechanistic Study of the Amino Acid-Catalyzed Aldol Condensation of Acetaldehyde in Aqueous and Salt Solutions, J. Phys. Chem. A, 112, 2827, 2008. 5Noziere, B., Dziedzic, P., and Cordova, A., The Formation of Secondary Light-Absorbing "fulvic-like" Oligomers: A Common Process in Aqueous and Ionic Atmospheric Particles?, Geophys. Res. Lett., 34

  16. Inorganic membranes for carbon capture and power generation

    Science.gov (United States)

    Snider, Matthew T.

    Inorganic membranes are under consideration for cost-effective reductions of carbon emissions from coal-fired power plants, both in the capture of pollutants post-firing and in the direct electrochemical conversion of coal-derived fuels for improved plant efficiency. The suitability of inorganic membrane materials for these purposes stems as much from thermal and chemical stability in coal plant operating conditions as from high performance in gas separations and power generation. Hydrophilic, micro-porous zeolite membrane structures are attractive for separating CO2 from N2 in gaseous waste streams due to the attraction of CO2 to the membrane surface and micropore walls that gives the advantage to CO2 transport. Recent studies have indicated that retention of the templating agent used in zeolite synthesis can further block N2 from the micropore interior and significantly improve CO2/N2 selectivity. However, the role of the templating agent in micro-porous transport has not been well investigated. In this work, gas sorption studies were conducted by high-pressure thermo-gravimetric analysis on Zeolite Y membrane materials to quantify the effect of the templating agent on CO2, N2, and H2O adsorption/desorption, as well as to examine the effect of humidification on overall membrane performance. In equilibrium conditions, the N2 sorption enthalpy was nearly unchanged by the presence of the templating agent, but the N2 pore occupation was reduced ˜1000x. Thus, the steric nature of the blocking of N2 from the micropores by the templating agent was confirmed. CO2 and H2O sorption enthalpies were similarly unaffected by the templating agent, and the micropore occupations were only reduced as much as the void volume taken up by the templating agent. Thus, the steric blocking effect did not occur for molecules more strongly attracted to the micropore walls. Additionally, in time-transient measurements the CO 2 and H2O mobilities were significantly enhanced by the presence

  17. COSIMA-Rosetta calibration for in-situ characterization of 67P/Churyumov-Gerasimenko cometary inorganic compounds

    CERN Document Server

    Krüger, Harald; Engrand, Cécile; Briois, Christelle; Siljeström, Sandra; Merouane, Sihane; Baklouti, Donia; Fischer, Henning; Fray, Nicolas; Hornung, Klaus; Lehto, Harry; Orthous-Daunay, François-Régis; Rynö, Jouni; Schulz, Rita; Silen, Johan; Thirkell, Laurent; Trieloff, Mario; Hilchenbach, Martin

    2015-01-01

    COSIMA (COmetary Secondary Ion Mass Analyser) is a time-of-flight secondary ion mass spectrometer (TOF-SIMS) on board the Rosetta space mission. COSIMA has been designed to measure the composition of cometary dust grains. It has a mass resolution m/{\\Delta}m of 1400 at mass 100 u, thus enabling the discrimination of inorganic mass peaks from organic ones in the mass spectra. We have evaluated the identification capabilities of the reference model of COSIMA for inorganic compounds using a suite of terrestrial minerals that are relevant for cometary science. Ground calibration demonstrated that the performances of the flight model were similar to that of the reference model. The list of minerals used in this study was chosen based on the mineralogy of meteorites, interplanetary dust particles and Stardust samples. It contains anhydrous and hydrous ferromagnesian silicates, refractory silicates and oxides (present in meteoritic Ca-Al-rich inclusions), carbonates, and Fe-Ni sulfides. From the analyses of these mi...

  18. Structural Characterization and Infrared and Electrical Properties of the New Inorganic-Organic Hybrid Compound

    OpenAIRE

    Oueslati, A.; Chaabane, I.; K. Adil; F. Hlel

    2013-01-01

    New inorganic-organic hybrid [(C3H7)4N]2Hg2Cl6 compound was obtained and characterised by single-crystal X-ray diffraction, infrared, and impedance spectroscopy. The latter crystallizes in the monoclinic system (space group C 2/c, ) with the following unit cell dimensions: (1) Å, (6) Å, (2) Å, and (2). Besides, its structure was solved using 84860 independent reflections leading to . Electrical properties of the material were studied using impedance spectroscopic technique at different temper...

  19. Drivers of inorganic carbon dynamics in first-year sea ice: A model study

    DEFF Research Database (Denmark)

    Moreau, Sebastien; Vancoppenolle, Martin; Delille, Bruno;

    2015-01-01

    , of total dissolved inorganic carbon (DIC) and total alkalinity (TA) are represented using fluid transport equa- tions. Carbonate chemistry, the consumption, and release of CO2 by primary production and respiration, the precipitation and dissolution of ikaite (CaCO3ﰀ6H2O) and ice-air CO2 fluxes, are also...

  20. Bioengineering Aspects of Inorganic Carbon Supply to Mass Algal Cultures: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, J. C.

    1981-04-01

    Regardless of the application, the basic biotechnology of large-scale outdoor cultures involves many common features, particularly in the requirement for adequate nutrients such as carbon, nitrogen, and phosphorus to ensure that light is the sole limiting yield determinant. Whereas the required quantities of nitrogen and phosphorus are fairly simple, to estimate, those for inorganic carbon are far more complex.

  1. Inorganic carbon fluxes across the vadose zone of planted and unplanted soil mesocosms

    DEFF Research Database (Denmark)

    Thaysen, Eike Marie; Jacques, D.; Jessen, S.;

    2014-01-01

    The efflux of carbon dioxide (CO2) from soils influences atmospheric CO2 concentrations and thereby climate change. The partitioning of inorganic carbon (C) fluxes in the vadose zone between emission to the atmosphere and to the groundwater was investigated to reveal controlling underlying mechan...

  2. Dynamics of organic and inorganic carbon across contiguous mangrove and seagrass systems (Gazi Bay, Kenya)

    NARCIS (Netherlands)

    Bouillon, S.; Dehairs, F.; Velimirov, B.; Abril, G.; Borges, A.V.

    2007-01-01

    We report on the water column biogeochemistry in adjacent mangrove and seagrass systems in Gazi Bay (Kenya), with a focus on assessing the sources and cycling of organic and inorganic carbon. Mangrove and seagrass-derived material was found to be the dominant organic carbon sources in the water colu

  3. Inorganic Carbon Limitation and Chemical Composition of Two Freshwater Green Microalgae †

    Science.gov (United States)

    Goldman, Joel C.; Graham, Stephen J.

    1981-01-01

    Two freshwater chlorophytes, Chlorella vulgaris and Scenedesmus obliquus, were grown in inorganic carbon-limited continuous cultures in which HCO3− was the sole source of inorganic carbon. The response of the steady-state growth rate to the external total inorganic carbon concentration was reasonably well described by the Monod equation; however, the response to the internal nutrient concentration was only moderately well represented by the Droop equation when the internal carbon concentration was defined on a cellular basis. The Droop equation was totally inapplicable when total biomass (dry weight) was used to define internal carbon because the ratio of carbon to dry weight did not vary over the entire growth rate spectrum. In batch cultures, maximum growth rates were achieved at the CO2 levels present in atmospheric air and at HCO3− concentrations of 3 mM. No growth was observed at 100% CO2. Both nitrogen uptake and chlorophyll synthesis were tightly coupled to carbon assimilation, as indicated by the constant C/N and C/chlorophyll ratios found at all growth rates. The main influence of inorganic carbon limitation appears to be not on the chemical structure of the biomass, but rather on cell size; higher steady-state growth rates lead to bigger cells. PMID:16345701

  4. Inorganic carbon limitation and chemical composition of two freshwater green microalgae

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, J.C. (Woods Hole Oceanographic Inst., MA); Graham, S.J.

    1981-01-01

    Two freshwater Chlorophytes, Chlorella vulgaris and Scenedesmus obliquus, were grown in inorganic carbon-limited continuous cultures in which HCO/sub 3//sup -/ was the sole source of inorganic carbon. The response of the steady-state growth rate to the external total inorganic carbon concentration was reasonably well described by the Monod equation; however, the response to the internal nutrient concentration was only moderately well represented by the Droop equation when the internal carbon concentration was defined on a cellular basis. The Droop equation was totally inapplicable when total biomass (dry weight) was used to define internal carbon because the ratio of carbon to dry weight did not vary over the entire growth rate spectrum. In batch cultures, maximum growth rates were achieved at the CO/sub 2/ levels present in atmospheric air and at HCO/sub 3//sup -/ concentrations of 3 mM. No growth was observed at 100% CO/sub 2/. Both nitrogen uptake and chlorophyll synthesis were tightly coupled to carbon assimilation, as indicated by the constant C/N and C/chlorophyll ratios found at all growth rates. The main influence of inorganic carbon limitation appears to be not on the chemical structure of the biomass, but rather on cell size; higher steady-state growth rates lead to bigger cells.

  5. Influence of lead Inorganic Compounds on Combustion Rate of Double Base Rocket Propellants

    Directory of Open Access Journals (Sweden)

    V. B. Pillai

    1982-04-01

    Full Text Available The influence of lead nitrate, red lead, lead chromate, lead floride and lead carbonate on the combustion behaviour of double base propellants in the pressure range-35-140kg/cm /sup 2/ was studied. While all these compounds increased burning rates in lower pressure range (35-60 kg/cm/sup 2/ and higher pressure range (120-140 kg/cm/sup 2/, only lead chromate and lead fluoride were effective in the intermediate pressure range of 60-105 kg/cm/sup 2/. None of these compounds were effective as platonizer, except lead fluoride, which lowered n value to 0.34 in the lower pressure range. Addition of carbon black along with lead compounds raised burning rates further and reduced n values significantly in the higher pressure regins. A probable mechanism on the role of lead compounds studied has been suggested based on burning rate and DTA results.

  6. Modelling the inorganic ocean carbon cycle under past and future climate change

    International Nuclear Information System (INIS)

    This study used a coupled ocean-atmosphere-sea ice model with an inorganic carbon component to examine the inorganic ocean carbon cycle with particular reference to how climate feedback influences future uptake. In the last 150 years, the increase in atmosphere carbon dioxide (CO2) concentrations have been higher than any time during the Earth's history. Although the oceans are the largest sink for carbon dioxide, it is not know how the ocean carbon cycle will respond to increasing anthropogenic carbon dioxide concentrations in the future. Climate feedbacks could potentially reduce further uptake of carbon by the ocean. In addition to examining past climate transitions, including both abrupt and glacial-interglacial climate transitions, this study also examined the sensitivity of the inorganic carbon cycle to increased atmospheric carbon dioxide. Atmospheric carbon dioxide levels were also projected under a range of global warming scenarios. Most simulations identified a transient weakening of the North Atlantic and increased sea surface temperatures (SST). These positive feedbacks act on the carbon system to reduce uptake. However, the ocean has the capacity to take up 65 to 75 per cent of the anthropogenic carbon dioxide increases. An analysis of climate feedback on future carbon uptake shows that oceans store 7 per cent more carbon when there are no climate feedbacks acting on the system. Sensitivity experiments using the Gent McWilliams parameterization for mixing associated with mesoscale eddies show a further 6 per cent increase in oceanic uptake. Inclusion of sea ice dynamics resulted in a 2 per cent difference in uptake. This study also examined changes in atmospheric carbon dioxide concentration that occur during abrupt climate change events. Changes in ocean circulation and carbon solubility cause significant increases in atmospheric carbon dioxide concentrations when melt water episodes are simulated in both hemispheres. The response of the carbon cycle

  7. Heterocyclic compounds as carbonic anhydrase inhibitor.

    Science.gov (United States)

    Husain, Asif; Madhesia, Diwakar

    2012-12-01

    The carbonic anhydrases (CAs, EC 4.2.1.1) constitute interesting targets for the design of pharmacological agents useful in the treatment or prevention of a variety of disorders such as, glaucoma, acid-base disequilibria, epilepsy, and other neuromuscular diseases, altitude sickness, edema, and obesity. A quite new and unexpected application of the CA inhibitors (CAIs) is with regard to their potential use in the management (imaging and treatment) of hypoxic tumors. A series of sulfonamides, including some clinically used derivatives like acetazolamide, methazolamide, ethoxzolamide, dichlorophenamide, dorzolamide, brinzolamide, benzolamide, and sulpiride, or indisulam, a compound in clinical development as antitumor drug, as well as the sulfamate antiepileptic drug topiramate have been reported to inhibit various human carbonic anhydrase isozyme. Various heterocyclic sulfonamides have been reported in this review with their potency to inhibit different carbonic anhydrases isozymes. PMID:21981003

  8. Influence of Cd, Co, and Zn on inorganic carbon acquisition and carbon metabolism in Emiliania huxleyi.

    Science.gov (United States)

    Sutton, J. N.; Boye, M.; De La Broise, D.; Probert, I.

    2014-12-01

    Trace elements are essential micronutrients for primary producers; hence they influence the global carbon cycle and contribute to the regulation of Earth's climate. Over the past 25 years, the influence of Fe concentration on phytoplankton production has been well studied and this research has been instrumental in our understanding of the influence that biology has on the sequestration of atmospheric CO2. However, other trace elements that are directly involved in carbon metabolism by primary producers, such as Zn, Cd, and Co, have received less attention. We examined the physiological response of two strains of Emiliania huxleyi to a range of realistic trace element concentrations (Zn, Cd, Co) in the marine environment under batch, semi-continuous, and continuous culture conditions. In addition, the continuous culture system was maintained at a pH of 8.15 ±0.02 by a sensor and regulator-controlled CO2­ injection system. The results from this study will highlight the influence that trace element composition of seawater has on the growth rate, elemental quota, inorganic carbon uptake, and carbon metabolism of Emiliania huxleyi. Potential limitations for the interpretation of paleo-productivity records will be discussed.

  9. Inorganic Carbon Turnover caused by Digestion of Carbonate Sands and Metabolic Activity of Holothurians

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Kenneth; Silverman, Jacob; Kravitz, Benjamin S.; Rivlin, Tanya; Schneider-Mor, Aya; Barbosa, Sergio; Byrne, Maria; Caldeira, Ken

    2013-11-20

    Recent measurements have shown that holothurians (sea cucumbers) play an important role in the cycling of CaCO3 in tropical coral reef systems through ingestion and processing of carbonate sediment. In this study inorganic additional aspects of carbon turnover were determined in laboratory incubations of Holothuria atra, H. leucospilota and Stichopus herrmanni from One Tree Reef, Great Barrier Reef. The pH values of the gut lumen ranged from 6.1 to 6.7 in animals with empty digestive tracts as opposed to 7.0 to 7.6 when digestive tracts were filled with sediment. Empty gut volume estimates for H. atra and S. herrmanni were 36 ± 4 mL and 151 ± 14 mL, respectively. Based on these measurements it is estimated that these species process 19 ± 2kg and 80 ± 7kg CaCO3 sand yr-1 per individual, respectively. The annual dissolution rates of H. atra and S. herrmanni of 6.5±1.9g and 9.6±1.4g, respectively, suggest that 0.05±0.02% and 0.1±0.02% of the CaCO3 processed through their gut annually is dissolved. During the incubations the CaCO3 dissolution was 0.07±0.01%, 0.04±0.01% and 0.21±0.05% of the fecal casts for H. atra, H. leucospilota and S. herrmanni, respectively. The CaCO3 saturation state for both aragonite and calcite minerals during laboratory incubations decreased markedly due to a greater increase in dissolved inorganic carbon (DIC) relative to total alkalinity (AT) as a result of respiration by the animals. Our results support the hypothesis that deposit feeders such as sea cucumbers play an important ecological role in the coral reef CaCO3 cycle.

  10. Dynamics of organic and inorganic carbon across contiguous mangrove and seagrass systems (Gazi Bay, Kenya)

    OpenAIRE

    BOUILLON, S; F. Dehairs; Velimirov, B.; Abril, G.; Borges, A. V.

    2007-01-01

    [1] We report on the water column biogeochemistry in adjacent mangrove and seagrass systems in Gazi Bay (Kenya), with a focus on assessing the sources and cycling of organic and inorganic carbon. Mangrove and seagrass-derived material was found to be the dominant organic carbon sources in the water column, and could be distinguished on the basis of their delta C-13 signatures and particulate organic carbon: total suspended matter (POC/TSM) ratios. Spatially, a distinct boundary existed whereb...

  11. The Mechanisms of Calcification in Coccolithophores - The molecular basis of calcium and inorganic carbon transport in Emiliania huxleyi

    OpenAIRE

    Mackinder, Luke

    2012-01-01

    Coccolithophores are calcifying marine phytoplankton that through the fixation of inorganic carbon into calcite and particulate organic carbon play a fundamental role in global carbon cycles. As the CO2 concentration of the surface ocean increases through the anthropogenic release of CO2 by burning fossil fuels both a decrease in pH (ocean acidification) and a increase in dissolved inorganic carbon (ocean carbonation) are taking place. To understand the impact of these ocean changes on coccol...

  12. Assessment of methods for organic and inorganic carbon quantification in carbonate-containing Mediterranean soils

    Science.gov (United States)

    Apesteguia, Marcos; Virto, Iñigo; Plante, Alain

    2014-05-01

    Quantification of soil organic matter (SOM) stocks and fluxes continues to be an important endeavor in assessments of soil quality, and more broadly in assessments of ecosystem functioning. The quantification of SOM in alkaline, carbonate-containing soils, such as those found in Mediterranean areas, is complicated by the need to differentiate between organic carbon (OC) and inorganic carbon (IC), which continues to present methodological challenges. Acidification is frequently used to eliminate carbonates prior to soil OC quantification, but when performed in the liquid phase, can promote the dissolution and loss of a portion of the OC. Acid fumigation (AF) is increasingly preferred for carbonate removal, but its effectiveness is difficult to assess using conventional elemental and isotopic analyses. In addition, the potential effects of AF on SOM are not well characterized. The objective of the current study was to apply a multi-method approach to determine the efficacy of carbonate removal by AF and its effects on the residual SOM. We selected a set of 24 surface agricultural soils representing a large range of textures, SOM contents and presumed carbonate contents. For each soil, OC was determined using wet combustion (Walkley-Black) and IC was determined using the calcimeter method. Samples were then subjected to elemental (total C) and isotopic (δ13C) analyses by dry combustion using a Costech autoanalyzer coupled to a Thermo Finnigan Delta Plus isotope ratio mass spectrometer (IRMS) before and after AF. IC was equated to total C determined after fumigation, and OC was estimated as the different in total C before and after AF. Samples were also subjected to ramped oxidation using a Netzsch STA109 PC Luxx thermal analyzer coupled to a LICOR 820A infrared gas analyzer (IRGA). Quantification of OC was performed using evolved gas analysis of CO2 (CO2-EGA) in the exothermic region 200-500° C associated with organic matter combustion. IC was quantified by CO2-EGA

  13. Laboratory investigation of inorganic carbon uptake by cryoconite debris from Werenskioldbreen, Svalbard

    Science.gov (United States)

    Stibal, Marek; Tranter, Martyn

    2007-12-01

    Laboratory experiments were undertaken to determine the inorganic carbon uptake rate and the interactions between photosynthesis and water chemistry, particularly pH and nutrient concentrations, for cryoconite debris from Werenskioldbreen, a well-researched Svalbard glacier. Microorganisms in cryoconite debris took up inorganic carbon at rates between 0.6 and 15 μg C L-1 h-1 and fixed it as organic carbon. Cyanobacterial photosynthesis (75-93%) was the main process responsible for inorganic carbon fixation, while heterotrophic uptake (6-15%) only accounted for a minor part. The microbes in cryoconite debris were active shortly after melt and fixed carbon as long as there were favorable conditions. They were not truly psychrophilic: their physiological optimum temperature was higher than is prevalent in cryoconite holes. The pH was also a factor affecting photosynthesis in the cryoconite slurry. The highest dissolved inorganic carbon (DIC) uptake rates per liter of slurry occurred at pH ˜7, and there was a significant correlation between the initial pH and DIC fixation on a per cell basis, showing increasing DIC uptake rates when pH increased from ˜5.5 to 9. Inorganic carbon fixation resulted in an increased pH in solution. However, the microbes were able to photosynthesize in a wide range of pH from ˜4 to ˜10. The average C:N:P molar ratios in solution were ˜350:75:1. Unlike nitrogen, phosphorus concentrations decreased with increasing carbon uptake, and when the rate approached ˜15 μg C L-1 h-1, all available dissolved phosphorus was utilized within 6 h. Hence phosphorus is probably biolimiting in this system.

  14. Barium carbonate sediment sampling for inorganic dissolved carbon using isotope mass ratio spectrometer

    International Nuclear Information System (INIS)

    This paperwork explain the method of water sampling to obtain the precipitate of BaCO3 solutions that will be used to analyze 13C from field work in Kelana Jaya, Selangor, Langkawi, Kedah and Taiping, Perak. The sampling involves collecting of water samples for groundwater from boreholes and surface water from canal, river, pond and ex-mining pond from several locations at the study sites. This study also elaborates the instruments and chemicals used. The main purpose of this sampling is to obtain the precipitate of BaCO3 for 13C analysis of dissolved inorganic carbon (DIC). A correct sampling method according to standard is very important to ensure an accurate and precise result. With this, the data from the laboratory analysis result can be fully utilized to make the interpretation of the pollutants movement. (Author)

  15. Inorganic carbon fluxes across the vadose zone of planted and unplanted soil mesocosms

    DEFF Research Database (Denmark)

    Thaysen, Eike Marie; Jacques, D.; Jessen, S.;

    2014-01-01

    The efflux of carbon dioxide (CO2) from soils influences atmospheric CO2 concentrations and thereby climate change. The partitioning of inorganic carbon (C) fluxes in the vadose zone between emission to the atmosphere and to the groundwater was investigated to reveal controlling underlying...... mechanisms. Carbon dioxide partial pressure in the soil gas (pCO(2)), alkalinity, soil moisture and temperature were measured over depth and time in unplanted and planted (barley) mesocosms. The dissolved inorganic carbon (DIC) percolation flux was calculated from the pCO(2), alkalinity and the water flux at...... the mesocosm bottom. Carbon dioxide exchange between the soil surface and the atmosphere was measured at regular intervals. The soil diffusivity was determined from soil radon-222 (222Rn) emanation rates and soil air Rn concentration profiles and was used in conjunction with measured pCO(2) gradients...

  16. Interannual stability of organic to inorganic carbon production on a coral atoll

    Science.gov (United States)

    Kwiatkowski, Lester; Albright, Rebecca; Hosfelt, Jessica; Nebuchina, Yana; Ninokawa, Aaron; Rivlin, Tanya; Sesboüé, Marine; Wolfe, Kennedy; Caldeira, Ken

    2016-04-01

    Ocean acidification has the potential to adversely affect marine calcifying organisms, with substantial ocean ecosystem impacts projected over the 21st century. Characterizing the in situ sensitivity of calcifying ecosystems to natural variability in carbonate chemistry may improve our understanding of the long-term impacts of ocean acidification. We explore the potential for intensive temporal sampling to isolate the influence of carbonate chemistry on community calcification rates of a coral reef and compare the ratio of organic to inorganic carbon production to previous studies at the same location. Even with intensive temporal sampling, community calcification displays only a weak dependence on carbonate chemistry variability. However, across three years of sampling, the ratio of organic to inorganic carbon production is highly consistent. Although further work is required to quantify the spatial variability associated with such ratios, this suggests that these measurements have the potential to indicate the response of coral reefs to ongoing disturbance, ocean acidification, and climate change.

  17. Migration of residual nonvolatile and inorganic compounds from recycled post-consumer PET and HDPE

    Energy Technology Data Exchange (ETDEWEB)

    Dutra, Camila; Reyes, Felix G.R., E-mail: reyesfgr@fea.unicamp.br [Universidade de Campinas (UNICAMP), SP (Brazil). Escola de Engenharia dos Alimentos. Dept. de Ciencias dos Alimentos; Freire, Maria Teresa de A. [Universidade de Sao Paulo (USP), Pirassununga, SP (Brazil). Fac. de Ciencia Animal e Engenharia dos Alimentos. Dept. de Engenharia dos Alimentos; Nerin, Cristina; Bentayeb, Karim; Rodriguez-Lafuente, Angel; Aznar, Margarita [Dept. of Analytical Chemistry, Arago Inst. of Engineering Research, University of Zaragoza (Spain)

    2014-04-15

    Migration of nonvolatile and inorganic residual compounds from post-consumer recycled polyethylene terephthalate (PET) submitted to cleaning processes for subsequent production of materials intended to food contact, as well as from multilayer packaging material containing post-consumer recycled high-density polyethylene (HDPE) was determined. Tests were carried out using food simulant. Nonvolatile organic contaminants from PET, determined by liquid chromatography-mass spectrometry (UPLC-QqQ/MS), showed significant migration reduction as consequence of the more complex cleaning technologies applied. However, contaminants not allowed by Brazilian and European Union regulations were identified even in deep cleaning samples. Results from multilayer HDPE showed a greater number of contaminants when compared to recycled pellets. Inorganic contaminants, determined by inductively coupled plasma mass spectrometry were below the acceptable levels. Additional studies for identification and quantitation of unknown molecules which were not possible to identify in this study by UPLC-QqQ/MS are required to ascertain the safety of using post-consumer recycled packaging material. (author)

  18. Solubility Characteristics and Slow-Release Mechanism of Nitrogen from Organic-Inorganic Compound Coated Urea

    Directory of Open Access Journals (Sweden)

    Hongtao Zou

    2015-01-01

    Full Text Available A soil incubation method was used to investigate the solubility characteristics and slow-release mechanism of organic-inorganic compound coated urea at temperature of 10, 20, and 30°C. The membrane microstructure with and without incubation was tested via scanning electron microscopy (SEM. Slow release of nitrogen (N from different inorganic minerals was analysed by the activation energy from the nutrient solubility system. The rate of nitrogen solubility increased with temperature increasing. The first-order reaction kinetic equation described the solubility process of coated urea. The rate constant k also increased with temperature increasing. Moreover, the SEM images showed that the microstructure of the coating layer changed into a flocculent structure and the number of tiny pores and holes on the membrane surface increased significantly with temperature increasing, which increased N solubility rate. The Arrhenius equation indicated that activation energy was closely related to k during the solubility process; the activation energy was reduced with k rising, which resulted in N solubility rate increasing. Overall, the N solubility rate of coated urea was affected by temperature.

  19. Migration of residual nonvolatile and inorganic compounds from recycled post-consumer PET and HDPE

    International Nuclear Information System (INIS)

    Migration of nonvolatile and inorganic residual compounds from post-consumer recycled polyethylene terephthalate (PET) submitted to cleaning processes for subsequent production of materials intended to food contact, as well as from multilayer packaging material containing post-consumer recycled high-density polyethylene (HDPE) was determined. Tests were carried out using food simulant. Nonvolatile organic contaminants from PET, determined by liquid chromatography-mass spectrometry (UPLC-QqQ/MS), showed significant migration reduction as consequence of the more complex cleaning technologies applied. However, contaminants not allowed by Brazilian and European Union regulations were identified even in deep cleaning samples. Results from multilayer HDPE showed a greater number of contaminants when compared to recycled pellets. Inorganic contaminants, determined by inductively coupled plasma mass spectrometry were below the acceptable levels. Additional studies for identification and quantitation of unknown molecules which were not possible to identify in this study by UPLC-QqQ/MS are required to ascertain the safety of using post-consumer recycled packaging material. (author)

  20. Analysis of lunar samples for carbon compounds.

    Science.gov (United States)

    Kvenvolden, K. A.

    1971-01-01

    Description of one approach to the analysis for carbon compounds in lunar materials from the Apollo 11 mission. The sequential scheme followed generally accepted organic geochemical practices, but was unusual in its application to a single sample. The procedures of the scheme were designed to minimize handling of the solids and extracts or hydrolysates. The solid lunar sample was retained in all steps of the sequential analysis in the vessel in which it was originally placed. Centrifugation was used to separate solid and liquid phases after extraction or refluxing. Liquids were recovered from solids by decantation.

  1. Trivalent metal ions based on inorganic compounds with in vitro inhibitory activity of matrix metalloproteinase 13.

    Science.gov (United States)

    Wen, Hanyu; Qin, Yuan; Zhong, Weilong; Li, Cong; Liu, Xiang; Shen, Yehua

    2016-10-01

    Collagenase-3 (MMP-13) inhibitors have attracted considerable attention in recent years and have been developed as a therapeutic target for a variety of diseases, including cancer. Matrix metalloproteinases (MMPs) can be inhibited by a multitude of compounds, including hydroxamic acids. Studies have shown that materials and compounds containing trivalent metal ions, particularly potassium hexacyanoferrate (III) (K3[Fe(CN)6]), exhibit cdMMP-13 inhibitory potential with a half maximal inhibitory concentration (IC50) of 1.3μM. The target protein was obtained by refolding the recombinant histidine-tagged cdMMP-13 using size exclusion chromatography (SEC). The secondary structures of the refolded cdMMP-13 with or without metal ions were further analyzed via circular dichroism and the results indicate that upon binding with metal ions, an altered structure with increased domain stability was obtained. Furthermore, isothermal titration calorimetry (ITC) experiments demonstrated that K3[Fe(CN)6]is able to bind to MMP-13 and endothelial cell tube formation tests provide further evidence for this interaction to exhibit anti-angiogenesis potential. To the best of our knowledge, no previous report of an inorganic compound featuring a MMP-13 inhibitory activity has ever been reported in the literature. Our results demonstrate that K3[Fe(CN)6] is useful as a new effective and specific inhibitor for cdMMP-13 which may be of great potential for future drug screening applications. PMID:27542739

  2. [Stable compound of inorganic pyrophosphatase with pyrophosphate obtained by a fluoride-mediated reaction with phosphate].

    Science.gov (United States)

    Bakuleva, N P; Baikov, A A; Avaeva, S M

    1981-09-01

    Incubation of inorganic pyrophosphate from baker's yeast with phosphate and MgCl2 in the presence of fluoride results in a gradual inactivation of the enzyme concomitant with incorporation of PP1 (about 2 moles per mole) into the protein. The rate constant for this process shows an increase with a rise in concentrations of the three reagents, the maximal value of inactivation being 0.11 min-1. The bound PP1 is not separated by gel-filtration. The rate of spontaneous degradation of the enzyme-pyrophosphate complex and the nature of EDTA and Mg2+ effects are similar to those for the analogous compound obtained by inhibition of PP1 hydrolysis by fluoride. The data obtained suggest that during PP1 synthesis and hydrolysis by pyrophosphatase fluoride stabilizes the same intermediate of the enzyme with pyrophosphate. PMID:6117333

  3. Controlling the release of active compounds from the inorganic carrier halloysite

    International Nuclear Information System (INIS)

    Halloysite (HNTs), a natural material characterized by a nanotube structure, has been used as an inorganic carrier of active compounds in several applications from medicine to anticorrosion coatings. In this present work, vanillin (VAN) used as a antimicrobial model, has been encapsulated within HNTs for exploiting its applicability in the active food packaging sector. The molecule release rate has been controlled by crosslinking at the tube ends the loaded vanillin with copper ions, thus producing a stopper network. The vanillin-loaded HNTs were characterized using transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and thermo gravimetric analysis. The antimicrobial release kinetics from the loaded nanoparticles (VAN/HNTs) in water was investigated using UV-vis spectroscopy. The results show that the vanillin crosslinked with cupper ions is a feasible method to tailor the release rate of antimicrobial model from HTNs nanoparticles

  4. Controlling the release of active compounds from the inorganic carrier halloysite

    Science.gov (United States)

    Tescione, F.; Buonocore, G. G.; Stanzione, M.; Oliviero, M.; Lavorgna, M.

    2014-05-01

    Halloysite (HNTs), a natural material characterized by a nanotube structure, has been used as an inorganic carrier of active compounds in several applications from medicine to anticorrosion coatings. In this present work, vanillin (VAN) used as a antimicrobial model, has been encapsulated within HNTs for exploiting its applicability in the active food packaging sector. The molecule release rate has been controlled by crosslinking at the tube ends the loaded vanillin with copper ions, thus producing a stopper network. The vanillin-loaded HNTs were characterized using transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and thermo gravimetric analysis. The antimicrobial release kinetics from the loaded nanoparticles (VAN/HNTs) in water was investigated using UV-vis spectroscopy. The results show that the vanillin crosslinked with cupper ions is a feasible method to tailor the release rate of antimicrobial model from HTNs nanoparticles.

  5. Controlling the release of active compounds from the inorganic carrier halloysite

    Energy Technology Data Exchange (ETDEWEB)

    Tescione, F.; Buonocore, G. G.; Stanzione, M.; Oliviero, M.; Lavorgna, M. [National Research Council - Institute of Composites and Biomedical Materials, P.le E. Fermi, 1 80055 Portici (Naples) (Italy)

    2014-05-15

    Halloysite (HNTs), a natural material characterized by a nanotube structure, has been used as an inorganic carrier of active compounds in several applications from medicine to anticorrosion coatings. In this present work, vanillin (VAN) used as a antimicrobial model, has been encapsulated within HNTs for exploiting its applicability in the active food packaging sector. The molecule release rate has been controlled by crosslinking at the tube ends the loaded vanillin with copper ions, thus producing a stopper network. The vanillin-loaded HNTs were characterized using transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and thermo gravimetric analysis. The antimicrobial release kinetics from the loaded nanoparticles (VAN/HNTs) in water was investigated using UV-vis spectroscopy. The results show that the vanillin crosslinked with cupper ions is a feasible method to tailor the release rate of antimicrobial model from HTNs nanoparticles.

  6. Assessment of bacterial community structure in nitrifying biofilm under inorganic carbon-sufficient and -limited conditions.

    Science.gov (United States)

    Bae, Hyokwan; Chung, Yun-Chul; Yang, Heejeong; Lee, Changsoo; Aryapratama, Rio; Yoo, Young J; Lee, Seockheon

    2015-01-01

    In this work, nitrification and changes in the composition of the total bacterial community under inorganic carbon (IC)-limited conditions, in a nitrifying moving bed biofilm reactor, was investigated. A culture-independent analysis of cloning and sequencing based on the 16S rRNA gene was applied to quantify the bacterial diversity and to determine bacterial taxonomic assignment. IC concentrations had significant effects on the stability of ammonia-oxidation as indicated by the reduction of the nitrogen conversion rate with high NH4(+)-N loadings. The predominance of Nitrosomonas europaea was maintained in spite of changes in the IC concentration. In contrast, heterotrophic bacterial species contributed to a high bacterial diversity, and to a dynamic shift in the bacterial community structure, under IC-limited conditions. In this study, individual functions of heterotrophic bacteria were estimated based on taxonomic information. Possible key roles of coexisting heterotrophic bacteria are the assimilation of organic compounds of extracellular polymeric substances produced by nitrifiers, and biofilm formation by providing a filamentous structure and aggregation properties. PMID:25560266

  7. Developing inorganic carbon-based radiocarbon chronologies for Holocene lake sediments in arid NW China

    Science.gov (United States)

    Zhang, Jiawu; Ma, Xueyang; Qiang, Mingrui; Huang, Xiaozhong; Li, Shuang; Guo, Xiaoyan; Henderson, Andrew C. G.; Holmes, Jonathan A.; Chen, Fahu

    2016-07-01

    Inorganic carbonates are often used to establish radiocarbon (14C) chronologies for lake sediments when terrestrial plant remains (TPR) are rare or when bulk organic matter is insufficient for dating, a problem that is common for many lakes in arid regions. However, the reservoir effect (RE), as well as old carbon contributed from the lakes catchment make it difficult to establish reliable chronologies. Here we present a systematic study of inorganic 14C ages of two lake-sediment sequences, one from a small-enclosed saline lake - Lake Gahai in Qaidam Basin, and the other from a large freshwater lake - Lake Bosten in Xinjiang. Modern dissolved inorganic carbon (DIC) of the lakes, paleo-lake sediments exposed in the catchment, and mollusk shells in core sediments from Lake Gahai were dated to assess the RE and the contribution of pre-aged carbon to the old ages in the cores. We propose a statistical regression to assess more than one RE for the 14C carbonate ages within our sedimentary sequences. Old radiocarbon ages contributed by detrital carbonates were assessed by comparing the ages of mollusk shells with those of carbonates at the same sediment depths. We established the RE of the authigenic component and assessed detrital old carbon contributions to our two sites, and this was used to correct the 14C ages. Based on this approach, we developed age models for both cores, and tested them using 210Pb ages in both cores and TPR-based 14C-ages recovered from Lake Bosten. We further tested our age models by comparing carbonate-based oxygen isotope (δ18O) records from both lakes to an independently-dated regional speleothem δ18O record. Our results suggest if sedimentary sequences are densely dated and the RE and the contribution of old carbon from detrital carbonates can be ascertained, robust chronological frameworks based on carbonate-based 14C determinations can be established.

  8. High plasticity in inorganic carbon uptake by Southern Ocean phytoplankton in response to ambient CO2

    NARCIS (Netherlands)

    Neven, Ika A.; Stefels, Jacqueline; van Heuven, Steven M. A. C.; de Baar, Hein J. W.; Elzenga, J. Theo M.

    2011-01-01

    The fixation of dissolved inorganic carbon (DIC) by marine phytoplankton provides an important feedback mechanism on concentrations of CO2 in the atmosphere. As a consequence it is important to determine whether oceanic primary productivity is susceptible to changing atmospheric CO2 levels. Among nu

  9. High plasticity in inorganic carbon uptake by Southern Ocean phytoplankton in response to ambient CO

    NARCIS (Netherlands)

    Neven, I.A.; Stefels, J.; van Heuven, S.M.A.C.; de Baar, H.J.W.; Elzenga, J.T.M.

    2011-01-01

    The fixation of dissolved inorganic carbon (DIC) by marine phytoplankton provides an important feedback mechanism on concentrations of CO2 in the atmosphere. As a consequence it is important to determine whether oceanic primary productivity is susceptible to changing atmospheric CO2 levels. Among nu

  10. Carbon compounds in the atmosphere and their chemical reactions

    OpenAIRE

    Martišová, Petra

    2013-01-01

    The essay dissert on compounds of carbon in the atmosphere and its reaction. The most important are carbon dioxide, carbon monoxide and methane. Included among important compounds of carbon are volatile organic substances, polycyclic aromatic hydrocarbon and dioxin. Carbon dioxide and methane representing greenhouse gases have also indispensable meaning. As they, together with water vapour, nitrogen monoxide and other gases are causing the major part of greenhouse effect. Primarily because of...

  11. Critical review of animal carcinogenesis by cadmium and its inorganic compounds

    International Nuclear Information System (INIS)

    Animal carcinogenic biassays relative to 6 inorganic cadmium substances (cadmium metal, cadmium oxide, cadmium sulfide, cadmium sulfate, cadmium chloride and cadmium acetate) are reviewed (speciation). Critical evaluation of literature data on carcinogenicity has been performed by making reference to E.C. guidelines of good laboratory practice. There are few data on routes relevant for human risk assessment: experiments on inhalation demonstrate lung carcinogenicity of cadmium oxide, cadmium sulfide, cadmium sulfate and cadmium chloride in rats but not in mice nor in hamsters; no carcinogenic effects of cadmium compounds are observed following oral administration. For routes of less or no relevance for human risk assessment, some results are clearly positive: subcutaneous injection induces cancers in situ (various cadmium compounds), testicular tumours (cadmium sulfate and cadmium chloride) and prostatic tumours (cadmium chloride) but such effects are not observed using relevant malignancies in rats. With respect to other no relevant routes (intraperitoneal, intrarenal...) tumours are incidentally produced in situ, but not in remote organs. Numerous studies fail to demonstrate cadmium carcinogenicity, but methodologically acceptable negative ones are very limited in number. Accordingly strain dependent effects and dose effect relationship could not be thoroughly assessed

  12. Dissolved inorganic carbon and organic carbon in mires in the Forsmark area. A pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Loefgren, Anders [EcoAnalytica, Haegersten (Sweden)

    2011-12-15

    Dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) are the large dissolved carbon pools in mires. They are both related to a number of factors such as groundwater flow, minerogenic influence and peat properties, which all are more or less related to peatland development stage. In a scenario of a release of radionuclides from an underground repository containing radioactive material, behaviour of these pools during the mire ontogeny will be of importance for the understanding of how C-14 will constitute a potential risk to humans and non-human biota. In this pilot study, DIC and DOC concentrations were investigated for three mires representing a potential sequence of peatland development in a coastal area at Forsmark in central Sweden characterized by land upheaval, a flat topography and calcareous content in the soil. The mires where chosen based on difference in height above the sea level, covering approximate 1000 years, and characteristics based on their vegetation. Water samples were collected during August from all three mires at two different depths in the anoxic layer of the mires, by extracting water from peat obtained with a peat corer. DIC concentrations where related to the age of the mires, with the lowest concentrations in the highest located mire. There was a positive correlation between pH and DIC, where the higher DIC concentrations were found in the 'richer' fens. DIC concentrations were also positively related to the conductivity within and between the mires, where conductivity would be a proxy for the dominating cation Ca{sup 2+} associated to the calcareous-influenced groundwater. DOC concentrations were highest in the oldest mire, but were similar in the younger mires. No patterns were found between DIC and DOC, and the peat bulk density. The report ends with suggestions on how a continued study could be improved.

  13. Dissolved inorganic carbon and organic carbon in mires in the Forsmark area. A pilot study

    International Nuclear Information System (INIS)

    Dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) are the large dissolved carbon pools in mires. They are both related to a number of factors such as groundwater flow, minerogenic influence and peat properties, which all are more or less related to peatland development stage. In a scenario of a release of radionuclides from an underground repository containing radioactive material, behaviour of these pools during the mire ontogeny will be of importance for the understanding of how C-14 will constitute a potential risk to humans and non-human biota. In this pilot study, DIC and DOC concentrations were investigated for three mires representing a potential sequence of peatland development in a coastal area at Forsmark in central Sweden characterized by land upheaval, a flat topography and calcareous content in the soil. The mires where chosen based on difference in height above the sea level, covering approximate 1000 years, and characteristics based on their vegetation. Water samples were collected during August from all three mires at two different depths in the anoxic layer of the mires, by extracting water from peat obtained with a peat corer. DIC concentrations where related to the age of the mires, with the lowest concentrations in the highest located mire. There was a positive correlation between pH and DIC, where the higher DIC concentrations were found in the 'richer' fens. DIC concentrations were also positively related to the conductivity within and between the mires, where conductivity would be a proxy for the dominating cation Ca2+ associated to the calcareous-influenced groundwater. DOC concentrations were highest in the oldest mire, but were similar in the younger mires. No patterns were found between DIC and DOC, and the peat bulk density. The report ends with suggestions on how a continued study could be improved

  14. A study on inorganic carbon components in the Andaman Sea during the post monsoon season

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; Narvekar, P.V.

    stream_size 34289 stream_content_type text/plain stream_name Oceanol_Acta_24_125.pdf.txt stream_source_info Oceanol_Acta_24_125.pdf.txt Content-Encoding UTF-8 Content-Type text/plain; charset=UTF-8 A study on inorganic... moindre (environ 300 m) en mer d’Andaman, alors que les eaux plus profondes sont sous-saturées en calcite. © 2001 Ifremer/CNRS/IRD/Éditions scientifiques et médicales Elsevier SAS inorganic carbon / deep water / dissociation / Bay of Bengal / Andaman Sea...

  15. Understanding on Soil Inorganic Carbon Transformation in North China

    Science.gov (United States)

    Li, Guitong; Yang, Lifang; Zhang, Chenglei; Zhang, Hongjie

    2015-04-01

    Soil total carbon balance in long-term fertilization field experiments in North China Plain. Four long-term fertilization experiments (20-30 years) were investigated on SOC in 40 cm, calcium carbonate and active carbonate (AC) in 180 or 100 cm soil profile, δ13C values of SOC and δ13C and δ18O values of carbonate in soil profile, particle distribution of SOC and SIC in main soil layers, and ratios of pedogenic carbonate (PC) in SIC and C3-SOC in SOC. The most important conclusion is that fertilization of more than 20 years can produce detectable impact on pool size, profile distribution, ratio of active component and PC of SIC, which make it clear that SIC pool must be considered in the proper evaluation of the response of soil carbon balance to human activities in arid and semi-arid region. Land use impact on soil total carbon pool in Inner Mongolia. With the data of the second survey of soils in Inner Mongolia and the 58 soil profile data from Wu-lan-cha-bu-meng and Xi-lin-hao-te, combining with the 13C and 18O techniques, SIC density and stock in Inner Mongolia is estimated. The main conclusion is that soils in inner Mongolia have the same level of SOC and SIC, with the density in 100cm pedons of 8.97 kg•m-2 and 8.61 kg•m-2, respectively. Meanwhile, the significantly positive relationship between SOC and SIC in A layer indicates co-sequestration of SOC and SIC exist. Evaluation of the methods for measuring CA enzyme activity in soil. In laboratory, method in literature to measure CA activity in soil sample was repeated, and found it was not valid indeed. The failure could not attribute to the disturbance of common ions like NO3-, SO42-, Ca2+, and Mg2+. The adsorption of CA to soil material was testified as the main reason for that failure. A series of extractants were tested but no one can extract the adsorbed CA and be used in measuring CA activity in soil sample. Carbonate transformation in field with straw returned and biochar added. In 2009, a field

  16. Laser ablation of molecular carbon nitride compounds

    International Nuclear Information System (INIS)

    We present a method for the preparation of thin films on sapphire substrates of the carbon nitride precursors dicyandiamide (C2N4H4), melamine (C3N6H6), and melem (C6N10H6), using the femtosecond-pulsed laser deposition technique (femto-PLD) at different temperatures. The depositions were carried out under high vacuum with a femtosecond-pulsed laser. The focused laser beam is scanned on the surface of a rotating target consisting of the pelletized compounds. The resulting polycrystalline, opaque films were characterized by X-ray powder diffraction, infrared, Raman, and X-ray photoelectron spectroscopy, photoluminescence, SEM, and MALDI-TOF mass spectrometry measurements. The crystal structures and optical/spectroscopic results of the obtained rough films largely match those of the bulk materials

  17. Laser ablation of molecular carbon nitride compounds

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, D., E-mail: d.fischer@fkf.mpg.de [Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569 Stuttgart (Germany); Schwinghammer, K. [Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569 Stuttgart (Germany); Department of Chemistry, University of Munich, LMU, Butenandtstr. 5-13, 81377 Munich (Germany); Nanosystems Initiative Munich (NIM) and Center for Nanoscience (CeNS), 80799 Munich (Germany); Sondermann, C. [Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569 Stuttgart (Germany); Department of Chemistry, University of Munich, LMU, Butenandtstr. 5-13, 81377 Munich (Germany); Lau, V.W.; Mannhart, J. [Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569 Stuttgart (Germany); Lotsch, B.V. [Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569 Stuttgart (Germany); Department of Chemistry, University of Munich, LMU, Butenandtstr. 5-13, 81377 Munich (Germany); Nanosystems Initiative Munich (NIM) and Center for Nanoscience (CeNS), 80799 Munich (Germany)

    2015-09-15

    We present a method for the preparation of thin films on sapphire substrates of the carbon nitride precursors dicyandiamide (C{sub 2}N{sub 4}H{sub 4}), melamine (C{sub 3}N{sub 6}H{sub 6}), and melem (C{sub 6}N{sub 10}H{sub 6}), using the femtosecond-pulsed laser deposition technique (femto-PLD) at different temperatures. The depositions were carried out under high vacuum with a femtosecond-pulsed laser. The focused laser beam is scanned on the surface of a rotating target consisting of the pelletized compounds. The resulting polycrystalline, opaque films were characterized by X-ray powder diffraction, infrared, Raman, and X-ray photoelectron spectroscopy, photoluminescence, SEM, and MALDI-TOF mass spectrometry measurements. The crystal structures and optical/spectroscopic results of the obtained rough films largely match those of the bulk materials.

  18. Iron and inorganic carbon in Liaodong Gulf sediments of Bohai Sea in China

    Institute of Scientific and Technical Information of China (English)

    NIU Lifeng; LI Xuegang; SONG Jinming; YUAN Huamao; LI Ning; DAI Jicui

    2006-01-01

    Iron in seawater is an essential trace metal for phytoplankton that plays an important role in the marine carbon cycle. But most studies focused on oceanic iron fertilization in high nutrient low chlorophyll (HNLC) seawaters. A study of inorganic carbon (IC) forms and its influencing factors was presented in Liaodong Gulf sediments, and especially the influence of iron was discussed in detail. Inorganic carbon in Liaodong Gulf sediments was divided into five forms: NaCl, NH3·H2O, NaOH, NH2OH·HCl and HCl. The concentration of NaCl and NaOH forms were similar and they only occupied the minority of total inorganic carbon (TIC). However, NH3·H2O, NH2OH·HCl and HCl forms were the principal forms of TIC and accounted for more than 80% of TIC. Especially, the percentage of NH3·H2O form was much higher than that in the Changjiang River Estuary and Jiaozhou Bay sediments. All forms of inorganic carbon were influenced by organic carbon,pore water, iron, pH, redox potential(Eh) and sulfur potential(Es) in sediments, moreover, the influences had different characteristics for different IC forms. However, the redox reactions of iron affected mainly active IC forms. Iron had little effect on NH2OH·HCl and HCl forms of IC which were influenced mainly by pH. Iron had a stronger influence on NaCl, NaOH and NH3·H2O forms of IC; the influence of Fe2+ was higher than Fe3+ and its effect on NH3·H2O form was stronger than on NaCl and NaOH forms.

  19. The Production of Organic-Inorganic Compound Film-Coated Urea and the Characteristics of Its Nutrient Release

    Institute of Scientific and Technical Information of China (English)

    ZOU Hong-tao; WANG Yao-sheng; SONG Hao-wen; HAN Yan-yu; YU Na; ZHANG Yu-ling; DANG Xiu-li; HUANG Yi; ZHANG Yu-long

    2009-01-01

    The effect of different concentrations of natural macromolecular compound on the characteristics of nutrient release in the membrane materials of organic-inorganic compound film-coated urea was discussed,and the optimal concentrations for better nutrient release was proposed.The characteristics of nutrient release of film-coated urea were evaluated by soil column leaching experiment.Organic-inorganic compound film-coated urea showed good characteristics of nutrient release,which could be well simulated by Logistic curve.The two parameters in this curve,a and r,can be used to present nutrient release of film-coated urea,and followed the order of B > C > A and C < B < A,respectively,indicating that the release was stronger with the increasing concentration of natural maeromolecular compound in the membrane,which implied better controllability of nutrient release.The concentration of 5% of natural macromolecular compound showed better characteristic of nutrient release and can be utilized as a membrane material combined with inorganic mineral powders to develop film-coated slow-release fertilizer.

  20. Radionuclides, stable isotopes, inorganic constituents, and organic compounds in water from selected wells and springs from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman Area, Idaho, 1995

    International Nuclear Information System (INIS)

    The US Geological Survey and the Idaho Department of Water Resources, in cooperation with the US Department of Energy, sampled 17 sites as part of a long-term project to monitor water quality of the Snake River Plain aquifer from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman area. Water samples were collected and analyzed for selected radionuclides, stable isotopes, inorganic constituents, and organic compounds. The samples were collected from 11 irrigation wells, 2 domestic wells, 2 stock wells, 1 spring, and 1 public-supply well. Two quality assurance samples also were collected and analyzed. None of the radionuclide, inorganic constituents, or organic compound concentrations exceeded the established maximum contaminant levels for drinking water. Many of the radionuclide and inorganic constituent concentrations were greater than their respective reporting levels. All samples analyzed for dissolved organic carbon had concentrations that were greater than the minimum reporting level

  1. Radionuclides, stable isotopes, inorganic constituents, and organic compounds in water from selected wells and springs from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman Area, Idaho, 1994

    International Nuclear Information System (INIS)

    The US Geological Survey and the Idaho Department of Water Resources, in response to a request from the US Department of Energy, samples 18 sites as part of a long-term project to monitor water quality of the Snake River Plain aquifer from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman area. Water samples were collected and analyzed for selected radionuclides, stable isotopes, inorganic constituents, and organic compounds. The samples were collected from seven irrigation wells, seven domestic wells, two springs, one stock well, and one observation well. Two quality assurance samples also were collected and analyzed. None of the radionuclide, inorganic constituent, or organic compound concentrations exceeded the established maximum contaminant levels for drinking water. Many of the radionuclide and inorganic constituent concentrations exceeded their respective reporting levels. All samples analyzed for dissolved organic carbon had concentrations that exceeded their minimum reporting levels

  2. Radionuclides, stable isotopes, inorganic constituents, and organic compounds in water from selected wells and springs from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman Area, Idaho, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Bartholomay, R.C.; Williams, L.M. [Geological Survey, Idaho Falls, ID (United States); Campbell, L.J. [Idaho Dept. of Water Resources, Boise, ID (United States)

    1995-10-01

    The US Geological Survey and the Idaho Department of Water Resources, in response to a request from the US Department of Energy, samples 18 sites as part of a long-term project to monitor water quality of the Snake River Plain aquifer from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman area. Water samples were collected and analyzed for selected radionuclides, stable isotopes, inorganic constituents, and organic compounds. The samples were collected from seven irrigation wells, seven domestic wells, two springs, one stock well, and one observation well. Two quality assurance samples also were collected and analyzed. None of the radionuclide, inorganic constituent, or organic compound concentrations exceeded the established maximum contaminant levels for drinking water. Many of the radionuclide and inorganic constituent concentrations exceeded their respective reporting levels. All samples analyzed for dissolved organic carbon had concentrations that exceeded their minimum reporting levels.

  3. Radionuclides, stable isotopes, inorganic constituents, and organic compounds in water from selected wells and springs from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman Area, Idaho, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Bartholomay, R.C.; Williams, L.M. [Geological Survey, Idaho Falls, ID (United States); Campbell, L.J. [Idaho Dept. of Water Resources, Boise, ID (United States)

    1996-09-01

    The US Geological Survey and the Idaho Department of Water Resources, in cooperation with the US Department of Energy, sampled 17 sites as part of a long-term project to monitor water quality of the Snake River Plain aquifer from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman area. Water samples were collected and analyzed for selected radionuclides, stable isotopes, inorganic constituents, and organic compounds. The samples were collected from 11 irrigation wells, 2 domestic wells, 2 stock wells, 1 spring, and 1 public-supply well. Two quality assurance samples also were collected and analyzed. None of the radionuclide, inorganic constituents, or organic compound concentrations exceeded the established maximum contaminant levels for drinking water. Many of the radionuclide and inorganic constituent concentrations were greater than their respective reporting levels. All samples analyzed for dissolved organic carbon had concentrations that were greater than the minimum reporting level.

  4. Dissolved inorganic carbon (DIC) and its δ13C in the Ganga (Hooghly) River estuary, India: Evidence of DIC generation via organic carbon degradation and carbonate dissolution

    Digital Repository Service at National Institute of Oceanography (India)

    Samanta, S.; Dalai, T.K.; Pattanaik, J.K.; Rai, S.K.; Mazumdar, A.

    In this study, we present comprehensive data on dissolved Ca, dissolved inorganic carbon (DIC) and its carbon isotope composition (δ13CDIC) of (i) the Ganga (Hooghly) River estuary water sampled during six seasons...

  5. Tritium isolation from lithium inorganic compounds applicable to thermonuclear reactor breeding blanket

    International Nuclear Information System (INIS)

    Tritium separation from inorganic lithium compounds: Li2O, LiAlO2, Li2SiO3, Li4SiO4, LiF, LiBeF3, Li2BeF4 irradiated with a beam of a gamma facility and a nuclear reactor, has been studied. In the first case the gas phase is absent. In the latter one- the tritium amount in the gas does not exceed 1-2% of its total amount in the salt. Based on the EPR spectra of irradiated salts the concentrations of paramagnetic centres are calculated. It is shown that during thermal annealing the main portion of tritium in the gas phase is in the form of oxide (HTO, T2O). Tritium is separated from lithium fluoroberyllates in the form of hydrogen (HT, T2). The kinetics of tritium oxide isolation from irradiated lithium oxide aluminate, metha- and orthosilicates, lithium sulphate has been studied. The activation energies of tritium oxide separation process are presented. A supposition is made that chemical reaction of the HTO (T2O) or HT(T2) or HF(TF) formation is a limiting stage. Clarification of the process stage limiting the rate of tritium recovery will permit to evaluate conditions for the optimum work of lithium material in the blanket, lithium zone to select the lithium element structure and temperature regime of irradiation

  6. Simultaneous determination of inorganic mercury and methylmercury compounds in natural waters

    Energy Technology Data Exchange (ETDEWEB)

    Logar, Martina; Horvat, Milena [Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Akagi, Hirokatsu [National Institute for Minamata Disease, 4058-18 Hama, Minamata, Kumamoto 867-0008 (Japan); Pihlar, Boris [Faculty of Chemistry and Chemical Technology, University of Ljubljana, Askerceva 5, 1000 Ljubljana (Slovenia)

    2002-11-01

    The purpose of the present work was to develop a simple, rapid, sensitive and accurate method for the simultaneous determination of inorganic mercury (Hg{sup 2+}) and monomethylmercury compounds (MeHg) in natural water samples at the pg L{sup -1} level. The method is based on the simultaneous extraction of MeHg and Hg{sup 2+}dithizonates into an organic solvent (toluene) after acidification of about 300 mL of a water sample, followed by back extraction into an aqueous solution of Na {sub 2}S, removal of H {sub 2}S by purging with N {sub 2}, subsequent ethylation with sodium tetraethylborate, room temperature precollection on Tenax, isothermal gas chromatographic separation (GC), pyrolysis and cold vapour atomic fluorescence spectrometric detection (CV AFS) of mercury. The limit of detection calculated on the basis of three times the standard deviation of the blank was about 0.006 ng L {sup -1} for MeHg and 0.06 ng L {sup -1} for Hg {sup 2+}when 300 mL of water was analysed. The repeatability of the results was about 5% for MeHg and 10% for Hg {sup 2+}. Recoveries were 90-110% for both species. (orig.)

  7. RNA transcript sequencing reveals inorganic sulfur compound oxidation pathways in the acidophile Acidithiobacillus ferrivorans.

    Science.gov (United States)

    Christel, Stephan; Fridlund, Jimmy; Buetti-Dinh, Antoine; Buck, Moritz; Watkin, Elizabeth L; Dopson, Mark

    2016-04-01

    Acidithiobacillus ferrivoransis an acidophile implicated in low-temperature biomining for the recovery of metals from sulfide minerals.Acidithiobacillus ferrivoransobtains its energy from the oxidation of inorganic sulfur compounds, and genes encoding several alternative pathways have been identified. Next-generation sequencing ofAt. ferrivoransRNA transcripts identified the genes coding for metabolic and electron transport proteins for energy conservation from tetrathionate as electron donor. RNA transcripts suggested that tetrathionate was hydrolyzed by thetetH1gene product to form thiosulfate, elemental sulfur and sulfate. Despite two of the genes being truncated, RNA transcripts for the SoxXYZAB complex had higher levels than for thiosulfate quinone oxidoreductase (doxDAgenes). However, a lack of heme-binding sites insoxXsuggested that DoxDA was responsible for thiosulfate metabolism. Higher RNA transcript counts also suggested that elemental sulfur was metabolized by heterodisulfide reductase (hdrgenes) rather than sulfur oxygenase reductase (sor). The sulfite produced as a product of heterodisulfide reductase was suggested to be oxidized by a pathway involving thesatgene product or abiotically react with elemental sulfur to form thiosulfate. Finally, several electron transport complexes were involved in energy conservation. This study has elucidated the previously unknownAt. ferrivoranstetrathionate metabolic pathway that is important in biomining. PMID:26956550

  8. Regulation of a novel Acidithiobacillus caldus gene cluster involved in metabolism of reduced inorganic sulfur compounds.

    Science.gov (United States)

    Rzhepishevska, Olena I; Valdés, Jorge; Marcinkeviciene, Liucija; Gallardo, Camelia Algora; Meskys, Rolandas; Bonnefoy, Violaine; Holmes, David S; Dopson, Mark

    2007-11-01

    Acidithiobacillus caldus has been proposed to play a role in the oxidation of reduced inorganic sulfur compounds (RISCs) produced in industrial biomining of sulfidic minerals. Here, we describe the regulation of a new cluster containing the gene encoding tetrathionate hydrolase (tetH), a key enzyme in the RISC metabolism of this bacterium. The cluster contains five cotranscribed genes, ISac1, rsrR, rsrS, tetH, and doxD, coding for a transposase, a two-component response regulator (RsrR and RsrS), tetrathionate hydrolase, and DoxD, respectively. As shown by quantitative PCR, rsrR, tetH, and doxD are upregulated to different degrees in the presence of tetrathionate. Western blot analysis also indicates upregulation of TetH in the presence of tetrathionate, thiosulfate, and pyrite. The tetH cluster is predicted to have two promoters, both of which are functional in Escherichia coli and one of which was mapped by primer extension. A pyrrolo-quinoline quinone binding domain in TetH was predicted by bioinformatic analysis, and the presence of an o-quinone moiety was experimentally verified, suggesting a mechanism for tetrathionate oxidation. PMID:17873067

  9. Atmospheric Deposition of Inorganic Elements and Organic Compounds at the Inlets of the Venice Lagoon

    Directory of Open Access Journals (Sweden)

    E. Morabito

    2014-01-01

    Full Text Available The Venice Lagoon is subjected to long-range transport of contaminants via aerosol from the near Po Valley. Moreover, it is an area with significant local anthropogenic emissions due to the industrial area of Porto Marghera, the urban centres, and the glass factories and with emissions by ships traffic within the Lagoon. Furthermore, since 2005, the Lagoon has also been affected by the construction of the MOSE (Modulo Sperimentale Elettromeccanico—Electromechanical Experimental Module mobile dams, as a barrier against the high tide. This work presents and discusses the results from chemical analyses of bulk depositions, carried out in different sites of the Venice Lagoon. Fluxes of pollutants were also statistically analysed on PCA with the aim of investigating the spatial variability of depositions and their correlation with precipitations. Fluxes of inorganic pollutants depend differently on precipitations, while organic compounds show a more seasonal trend. The statistical analysis showed that the site in the northern Lagoon has lower and almost homogeneous fluxes of pollutants, while the other sites registered more variable concentrations. The study also provided important information about the annual trend of pollutants and their evolution over a period of about five years, from 2005 to 2010.

  10. Calcium Carbonate Formation by Genetically Engineered Inorganic Binding Peptides

    Science.gov (United States)

    Gresswell, Carolyn Gayle

    Understanding how organisms are capable of forming (synthesize, crystallize, and organize) solid minerals into complex architectures has been a fundamental question of biomimetic materials chemistry and biomineralization for decades. This study utilizes short peptides selected using a cell surface display library for the specific polymorphs of calcium carbonate, i.e., aragonite and calcite, to identify two sets of sequences which can then be used to examine their effects in the formation, crystal structure, morphology of the CaCO3 minerals. A procedure of counter selection, along with fluorescence microscopy (FM) characterization, was adapted to insure that the sequences on the cells were specific to their respective substrate, i.e., aragonite or calcite. From the resulting two sets of sequences selected, five distinct strong binders were identified with a variety of biochemical characteristics and synthesized for further study. Protein derived peptides, using the known sequences of the proteins that are associated with calcite or aragonite, were also designed using a bioinformatics-based similarity analysis of the two sets of binders. In particular, an aragonite binding protein segment, AP7, a protein found in nacre, was chosen for this design and the resulting effects of the designed peptides and the AP7 were examined. Specifically, the binding affinities of the selected and the protein derived peptides off the cells were then tested using FM; these studies resulted in different binding characteristics of the synthesized and cellular bound peptides. Two of the peptides that displayed strong binding on the cells bound to neither of the CaCO 3 substrates and both the high and low similarity protein-derived peptides bound to both polymorphs. However, two of the peptides were found to only bind to their respective polymorph showing; these results are significant in that with this study it is demonstrated that the designed peptides based on experimental library

  11. Carbon-Based Compounds and Exobiology

    Science.gov (United States)

    Kerridge, John; DesMarais, David; Khanna, R. K.; Mancinelli, Rocco; McDonald, Gene; diBrozollo, Fillipo Radicati; Wdowiak, Tom

    1996-01-01

    The Committee for Planetary and Lunar Explorations (COMPLEX) posed questions related to exobiological exploration of Mars and the possibility of a population of carbonaceous materials in cometary nuclei to be addressed by future space missions. The scientific objectives for such missions are translated into a series of measurements and/or observations to be performed by Martian landers. These are: (1) A detailed mineralogical, chemical, and textural assessment of rock diversity at a landing site; (2) Chemical characterization of the materials at a local site; (3) Abundance of Hydrogen at any accessible sites; (4) Identification of specific minerals that would be diagnostic of aqueous processes; (5) Textual examination of lithologies thought to be formed by aqueous activity; (6) Search for minerals that might have been produced as a result of biological processes; (7) Mapping the distribution, in three dimensions, of the oxidant(s) identified on the Martian surface by the Viking mission; (8) Definition of the local chemical environment; (9) Determination of stable-isotopic ratios for the biogenic elements in surface mineral deposits; (10) Quantitative analysis of organic (non-carbonate) carbon; (11) Elemental and isotopic composition of bulk organic material; (12) Search for specific organic compounds that would yield information about synthetic mechanisms, in the case of prebiotic evolution, and about possible bio-markers, in the case of extinct or extant life; (13) and Coring, sampling, and detection of entrained gases and cosmic-ray induced reaction products at the polar ice cap. A discussion of measurements and/or observations required for cometary landers is included as well.

  12. Inorganic Nanoparticle-Modified Poly(Phenylene Sulphide)/ Carbon Fiber Laminates: Thermomechanical Behaviour

    OpenAIRE

    Díez-Pascual, Ana M.; Mohammed Naffakh

    2013-01-01

    Carbon fiber (CF)-reinforced high-temperature thermoplastics such as poly(phenylene sulphide) (PPS) are widely used in structural composites for aerospace and automotive applications. The porosity of CF-reinforced polymers is a very important topic for practical applications since there is a direct correlation between void content and mechanical properties. In this study, inorganic fullerene-like tungsten disulphide (IF-WS2) lubricant nanoparticles were used to manufacture PPS/IF-WS2/CF lamin...

  13. Optimized inorganic carbon regime for enhanced growth and lipid accumulation in Chlorella vulgaris

    OpenAIRE

    Egan J. Lohman; Gardner, Robert D; Pedersen, Todd; Peyton, Brent M; Cooksey, Keith E; Gerlach, Robin

    2015-01-01

    Background Large-scale algal biofuel production has been limited, among other factors, by the availability of inorganic carbon in the culture medium at concentrations higher than achievable with atmospheric CO2. Life cycle analyses have concluded that costs associated with supplying CO2 to algal cultures are significant contributors to the overall energy consumption. Results A two-phase optimal growth and lipid accumulation scenario is presented, which (1) enhances the growth rate and (2) the...

  14. Modelling carbon isotope composition of dissolved inorganic carbon and methane in marine porewaters

    Science.gov (United States)

    Meister, Patrick; Liu, Bo; Khalili, Arzhang; Barker Jørgensen, Bo

    2014-05-01

    Carbon isotope compositions of dissolved inorganic carbon (DIC) and methane (CH4) in marine sedimentary porewaters at near surface temperatures show extremely large variation in apparent fractionation covering a range from -100 ‰ to +30 ‰. This fractionation is essentially the result of microbial activity, but the mechanisms and factors controlling this fractionation are still incompletely understood. This study provides a reaction transport model approach to evaluate the effects of the most important processes and factors on carbon isotope distribution with the goal to better understand carbon isotope distribution in modern sediment porewaters and in the geological record. Our model results show that kinetic fractionation during methanogenesis, both through the acetoclastic and autotrophic pathways, results in a nearly symmetrical distribution of δ13C values in DIC and CH4 with respect to the isotope value of buried organic matter. An increased fractionation factor during methanogenesis leads to a larger difference between δ13CDIC and δ13CCH4. Near the sulphate methane transition zone, DIC is more depleted in 13C due to diffusive mixing with DIC produced by anaerobic oxidation of methane (AOM) and organoclastic sulphate reduction. The model also shows that an upward decrease in δ13CCH4 near the SMT can only be caused by equilibrium fractionation during AOM including a backward "leakage" of carbon from DIC to CH4 through the enzymatic pathway. However, this effect of reversibility has no influence on the DIC pool as long as methane is completely consumed at the SMT. Only a release of methane at the sediment-water interface, due to a fraction of the methane escaping re-oxidation, results in a small shift towards more positive δ13CDIC values. Methane escape at the SMT is possible if either the methane flux is too high to be entirely oxidized by AOM, or if bubbles of methane gas by-pass the sulphate reduction zone and escape episodically into the water column

  15. Physical and bacterial controls on inorganic nutrients and dissolved organic carbon during a sea ice growth and decay experiment

    DEFF Research Database (Denmark)

    Zhou, J.; Delille, B.; Kaartokallio, H.;

    2014-01-01

    We investigated how physical incorporation, brine dynamics and bacterial activity regulate the distribution of inorganic nutrients and dissolved organic carbon (DOC) in artificial sea ice during a 19-day experiment that included periods of both ice growth and decay. The experiment was performed...... major changes in DOC concentrations. (3) Different forms of DOC have different properties and hence incorporation efficiencies. In particular, the terrestrially-derived DOC from the river water was less efficiently incorporated into sea ice than the DOC in the seawater. Therefore the main factors...... regulating the distribution of the dissolved compounds within sea ice are clearly a complex interaction of brine dynamics, biological activity and in the case of dissolved organic matter, the physico-chemical properties of the dissolved constituents themselves....

  16. Volatile organic compound emissions in relation to plant carbon fixation and the terrestrial carbon budget

    OpenAIRE

    Kesselmeier, J.; P. Ciccioli; Kuhn, U.; Stefani, P.; Biesenthal, T.; Rottenberger, S.; Wolf, A.; Vitullo, M.; R. Valentini; Nobre, A.; Kabat, P.; Andreae, M.O.

    2002-01-01

    A substantial amount of carbon is emitted by terrestrial vegetation as biogenic volatile organic compounds (VOC), which contributes to the oxidative capacity of the atmosphere, to particle production and to the carbon cycle. With regard to the carbon budget of the terrestrial biosphere, a release of these carbon compounds is regarded as a loss of photosynthetically fixed carbon. The significance of this loss for the regional and global carbon cycles is controversial. We estimate the amount of...

  17. A simple one step organic to inorganic pyrolysis route to bulk quantity boron carbonitride/carbon nanocables

    International Nuclear Information System (INIS)

    Highlights: • Bulk quantity boron carbonitride/carbon (BCN/C) nanocables have been synthesized by a simple one step organic to inorganic pyrolysis route. • BCN/C nanocables exhibit a much better oxidation resistance than substrate carbon nanofibers. • A probable formation mechanism of the BCN/C nanocables is proposed according to the experimental results. - Abstract: Bulk quantity boron carbonitride/carbon (BCN/C) nanocables have been successfully synthesized by a simple one step organic compounds pyrolysis route at 1100 °C. The nanocables consist of nanocarbon fibers inside covered by the cylindrical BCN coatings. The characteristics of the surface morphology and the diameters of the nanocables are determined by soaking time. It is demonstrated that the elements of B, C and N are hybridly bonded in the coating. The weight loss of the nanocables is about 12% at 1200 °C which is much better than the substrate carbon nanofibers (CNFs) (more than 20% weight loss at 1200 °C). The minimum reflection coefficient below −20 dB for the products is −24.5 dB at 14.48 GHz indicating good microwave absorption properties. The results suggest that the nanocables are favorable for achieving high performance oxidization resistance and microwave absorption properties

  18. Instrumentation and analytical methods in carbon balance studies - inorganic components in a marine environment

    Energy Technology Data Exchange (ETDEWEB)

    Skjelvan, I.; Johannessen, T.; Miller, L.; Stoll, M.

    1996-03-01

    This paper was read at the workshop ``The Norwegian Climate and Ozone Research Programme`` held on 11-12 March 1996. Substantial amounts of anthropogenic CO{sub 2} enters the atmosphere. The land biota acts as a sink for CO{sub 2}, with uncertain consequences. About 30% of the anthropogenic CO{sub 2} added to the atmosphere is absorbed by the ocean and how the ocean acts as a sink is central in understanding the carbon cycle. In their project the authors investigate the inorganic carbon in the ocean, especially total dissolved inorganic carbon, alkalinity, and partial pressure of CO{sub 2} (pCO{sub 2}) in surface ocean and atmosphere. To determine total dissolved inorganic carbon, coulometric analysis is used in which an exact amount of sea water is acidified and the amount of carbon extracted is determined by a coulometer. Alkalinity is determined by potentiometric titration. In the pCO{sub 2} measurement, a small amount of air is circulated in a large amount of sea water and when after some time the amount of CO{sub 2} in the air reflects the CO{sub 2} concentration in the water, the pCO{sub 2} in the gas phase is determined by infra-red detection. The atmospheric pCO{sub 2} is also determined, and the difference between the two partial pressures gives information about source or sink activities. Total carbon and alkalinity measurements are done on discrete samples taken from all depths in the ocean, but for partial pressure detection an underway system is used, which determines the pCO{sub 2} in the surface ocean continuously

  19. CO2 perturbation experiments: similarities and differences between dissolved inorganic carbon and total alkalinity manipulations

    Directory of Open Access Journals (Sweden)

    U. Riebesell

    2009-10-01

    Full Text Available Increasing atmospheric carbon dioxide (CO2 through human activities and invasion of anthropogenic CO2 into the surface ocean alters the seawater carbonate chemistry, increasing CO2 and bicarbonate (HCO3− at the expense of carbonate ion (CO32− concentrations. This redistribution in the dissolved inorganic carbon (DIC pool decreases pH and carbonate saturation state (Ω. Several components of the carbonate system are considered potential key variables influencing for instance calcium carbonate precipitation in marine calcifiers such as coccolithophores, foraminifera, corals, mollusks and echinoderms. Unravelling the sensitivities of marine organisms and ecosystems to CO2 induced ocean acidification (OA requires well-controlled experimental setups and accurate carbonate system manipulations. Here we describe and analyse the chemical changes involved in the two basic approaches for carbonate chemistry manipulation, i.e. changing DIC at constant total alkalinity (TA and changing TA at constant DIC. Furthermore, we briefly introduce several methods to experimentally manipulate DIC and TA. Finally, we examine responses obtained with both approaches using published results for the coccolithophore Emiliania huxleyi. We conclude that under most experimental conditions in the context of ocean acidification DIC and TA manipulations yield similar changes in all parameters of the carbonate system, which implies direct comparability of data obtained with the two basic approaches for CO2 perturbation.

  20. Effects of acid mine drainage on dissolved inorganic carbon and stable carbon isotopes in receiving streams

    International Nuclear Information System (INIS)

    Dissolved inorganic carbon (DIC) constitutes a significant fraction of a stream's carbon budget, yet the role of acid mine drainage (AMD) in DIC dynamics in receiving streams remains poorly understood. The objective of this study was to evaluate spatial and temporal effects of AMD and its chemical evolution on DIC and stable isotope ratio of DIC (δ13CDIC) in receiving streams. We examined spatial and seasonal variations in physical and chemical parameters, DIC, and δ13CDIC in a stream receiving AMD. In addition, we mixed different proportions of AMD and tap water in a laboratory experiment to investigate AMD dilution and variable bicarbonate concentrations to simulate downstream and seasonal hydrologic conditions in the stream. Field and laboratory samples showed variable pH, overall decreases in Fe2+, alkalinity, and DIC, and variable increase in δ13CDIC. We attribute the decrease in alkalinity, DIC loss, and enrichment of 13C of DIC in stream water to protons produced from oxidation of Fe2+ followed by Fe3+ hydrolysis and precipitation of Fe(OH)3(s). The extent of DIC decrease and 13C enrichment of DIC was related to the amount of HCO3- dehydrated by protons. The laboratory experiment showed that lower 13C enrichment occurred in unmixed AMD (2.7 per mille ) when the amount of protons produced was in excess of HCO3- or in tap water (3.2 per mille ) where no protons were produced from Fe3+ hydrolysis for HCO3- dehydration. The 13C enrichment increased and was highest for AMD-tap water mixture (8.0 per mille ) where Fe2+ was proportional to HCO3- concentration. Thus, the variable downstream and seasonal 13C enrichment in stream water was due in part to: (1) variations in the volume of stream water initially mixed with AMD and (2) to HCO3- input from groundwater and seepage in the downstream direction. Protons produced during the chemical evolution of AMD caused seasonal losses of 50 to >98% of stream water DIC. This loss of DIC in AMD impacted streams may have

  1. Storage/Turnover rate of inorganic carbon and its dissolvable part in the profile of saline/alkaline soils.

    Directory of Open Access Journals (Sweden)

    Yugang Wang

    Full Text Available Soil inorganic carbon is the most common form of carbon in arid and semiarid regions, and has a very long turnover time. However, little is known about dissolved inorganic carbon storage and its turnover time in these soils. With 81 soil samples taken from 6 profiles in the southern Gurbantongute Desert, China, we investigated the soil inorganic carbon (SIC and the soil dissolved inorganic carbon (SDIC in whole profiles of saline and alkaline soils by analyzing their contents and ages with radiocarbon dating. The results showed that there is considerable SDIC content in SIC, and the variations of SDIC and SIC contents in the saline soil profile were much larger than that in the alkaline profile. SDIC storage accounted for more than 20% of SIC storage, indicating that more than 1/5 of the inorganic carbon in both saline and alkaline soil is not in non-leachable forms. Deep layer soil contains considerable inorganic carbon, with more than 80% of the soil carbon stored below 1 m, whether for SDIC or SIC. More importantly, SDIC ages were much younger than SIC in both saline soil and alkaline soil. The input rate of SDIC and SIC ranged from 7.58 to 29.54 g C m(-2 yr(-1 and 1.34 to 5.33 g C m(-2 yr(-1 respectively for saline soil, and from 1.43 to 4.9 g C m(-2 yr(-1 and 0.79 to 1.27 g C m(-2 yr(-1respectively for alkaline soil. The comparison of SDIC and SIC residence time showed that using soil inorganic carbon to estimate soil carbon turnover would obscure an important fraction that contributes to the modern carbon cycle: namely the shorter residence and higher input rate of SDIC. This is especially true for SDIC in deep layers of the soil profile.

  2. Technical Note: Mesocosm approach to quantify dissolved inorganic carbon percolation fluxes

    DEFF Research Database (Denmark)

    Thaysen, Eike Marie; Jessen, S.; Ambus, Per;

    2014-01-01

    Dissolved inorganic carbon (DIC) fluxes across the vadose zone are influenced by a complex interplay of biological, chemical and physical factors. A novel soil mesocosm system was evaluated as a tool for providing information on the mechanisms behind DIC percolation to the groundwater from...... unplanted soil. Carbon dioxide partial pressure (pCO(2)), alkalinity, soil moisture and temperature were measured with depth and time, and DIC in the percolate was quantified using a sodium hydroxide trap. Results showed good reproducibility between two replicate mesocosms. The pCO(2) varied between 0.2 and...

  3. Inorganic markers, carbonaceous components and stable carbon isotope from biomass burning aerosols in northeast China

    Science.gov (United States)

    Cao, F.; Zhang, Y.; Kawamura, K.

    2015-12-01

    To better characterize the sources of fine particulate matter (i.e. PM2.5) in Sanjiang Plain, Northeast China, aerosol chemical composition such total carbon (TC), organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), and inorganic ions were studied as well as stable carbon isotopic composition (δ13C) of TC. Intensively open biomass burning episodes were identified from late September to early October by satellite fire and aerosol optical depth maps. During the biomass burning episodes, concentrations of PM2.5, OC, EC, and WSOC increased by a factor of 4-12 compared to non-biomass-burning periods. Non-sea-salt potassium is strongly correlated with PM2.5, OC, EC and WSOC, suggesting an important contribution of biomass burning emission. The enrichment in both the non-sea-salt potassium and chlorine is significantly larger than other inorganic species, indicating that biomass burning aerosols in Sanjiang Plain is mostly fresh and less aged. In addition, WSOC to OC ratio is relatively lower compared to that reported in biomass burning aerosols in tropical regions, supporting that biomass burning aerosols in Sanjiang Plain is mostly primary and secondary organic aerosols is not significant. A lower average δ13C value (-26.2‰) is found for the biomass-burning aerosols, suggesting a dominant contribution from combustion of C3 plants in the studied region.

  4. CO2 perturbation experiments: similarities and differences between dissolved inorganic carbon and total alkalinity manipulations

    Directory of Open Access Journals (Sweden)

    U. Riebesell

    2009-04-01

    Full Text Available Increasing atmospheric carbon dioxide (CO2 through human activities and invasion of anthropogenic CO2 into the surface ocean alters the seawater carbonate chemistry, increasing CO2 and bicarbonate (HCO3 at the expense of carbonate ion (CO32− concentrations. This redistribution in the dissolved inorganic carbon (DIC pool decreases pH and carbonate saturation state (Ω. Several of these components are considered potential key variables influencing calcium carbonate precipitation in marine calcifiers such as coccolithophores, foraminifera, corals, mollusks and echinoderms. In need for improved understanding of the sensitivities of marine organisms and ecosystems to CO2 induced ocean acidification (OA, experimental CO2 perturbation studies will continue to be a backbone in future OA research. This requires accurate carbonate system manipulations and well-controlled experimental setups. Here we describe and analyse the chemical changes involved in the two basic approaches for carbonate chemistry manipulation, i.e. changing DIC at constant total alkalinity (TA and changing TA at constant DIC. Furthermore, we briefly introduce several methods to experimentally manipulate DIC and TA. Finally, we examine responses obtained with both approaches using published results for the coccolithophore Emiliania huxleyi. We conclude that under most experimental conditions DIC or TA manipulations yield similar changes in all parameters of the carbonate system, which implies direct comparability of data obtained with the two basic approaches for CO2 perturbation.

  5. Spatial sensitivity of inorganic carbon to model setup: North Sea and Baltic Sea with ECOSMO

    Science.gov (United States)

    Castano Primo, Rocio; Schrum, Corinna; Daewel, Ute

    2015-04-01

    In ocean biogeochemical models it is critical to capture the key processes adequately so they do not only reproduce the observations but that those processes are reproduced correctly. One key issue is the choice of parameters, which in most cases are estimates with large uncertainties. This can be the product of actual lack of detailed knowledge of the process, or the manner the processes are implemented, more or less complex. In addition, the model sensitivity is not necessarily homogenous across the spatial domain modelled, which adds another layer of complexity to biogeochemical modelling. In the particular case of the inorganic carbon cycle, there are several sets of carbonate constants that can be chosen. The calculated air-sea CO2 flux is largely dependent on the parametrization chosen. In addition, the different parametrizations all the underlying processes that in some way impact the carbon cycle beyond the carbonate dissociation and fluxes give results that can be significantly different. Examples of these processes are phytoplankton growth rates or remineralization rates. Despite their geographical proximity, the North and Baltic Seas exhibit very different dynamics. The North Sea receives important inflows of Atlantic waters, while the Baltic Sea is an almost enclosed system, with very little exchange from the North Sea. Wind, tides, and freshwater supply act very differently, but dominantly structure the ecosystem dynamics on spatial and temporal scales. The biological community is also different. Cyanobacteria, which are important due to their ability to fix atmospheric nitrogen, and they are only present in the Baltic Sea. These differentiating features have a strong impact in the biogeochemical cycles and ultimately shape the variations in the carbonate chemistry. Here the ECOSMO model was employed on the North Sea and Baltic Sea. The model is set so both are modelled at the same time, instead of having them run separately. ECOSMO is a 3-D coupled

  6. Effects of inorganic anions on carbon isotope fractionation during Fenton-like degradation of trichloroethene.

    Science.gov (United States)

    Liu, Yunde; Zhou, Aiguo; Gan, Yiqun; Li, Xiaoqian

    2016-05-01

    Understanding the magnitude and variability in isotope fractionation with respect to specific processes is crucial to the application of stable isotopic analysis as a tool to infer and quantify transformation processes. The variability of carbon isotope fractionation during Fenton-like degradation of trichloroethene (TCE) in the presence of different inorganic ions (nitrate, sulfate, and chloride), was investigated to evaluate the potential effects of inorganic anions on carbon isotope enrichment factor (ε value). A comparison of ε values obtained in deionized water, nitrate solution, and sulfate solution demonstrated that the ε values were identical and not affected by the presence of nitrate and sulfate. In the presence of chloride, however, the ε values (ranging from -6.3±0.8 to 10±1.3‰) were variable and depended on the chloride concentration, indicating that chloride could significantly affect carbon isotope fractionation during Fenton-like degradation of TCE. Thus, caution should be exercised in selecting appropriate ε values for the field application of stable isotope analysis, as various chloride concentrations may be present due to naturally present or introduced with pH adjustment and iron salts during Fenton-like remediation. Furthermore, the effects of chloride on carbon isotope fractionation may be able to provide new insights about reaction mechanisms of Fenton-like processes. PMID:26835895

  7. One-Dimensional Organic-Inorganic Nanocomposite Synthesized with Single-Walled Carbon Nanotube Templates

    Directory of Open Access Journals (Sweden)

    Wei Li

    2014-08-01

    Full Text Available This study reports on single-walled carbon nanotubes (SWCNT as templates for the preparation of 1D porous organic-inorganic hybrid composites. The in situ deposited SWCNT were sputter coated with Sn metal and thermally oxidized in air to form a SnO2/SWCNT nanowire framework on SiO2/Si substrate. Poly(acrylic acid (PAA was coated onto this scaffold through UV light-induced radical polymerization, which resulted in the final formation of hybrid composites. The structures of hybrid composites were investigated by scanning electron microscopy, transmission electron microscopy, infrared spectroscopy, and Raman spectroscopy. The results show that PAA was successfully coated and the structural advantage of nanowire was fairly maintained, which indicates that this framework is very stable for organic functionalization in solution. The simplicity of this method for the formation of porous organic-inorganic hybrid composites provides a potential application for nanoelectronic devices.

  8. Shallow Remineralization in the Sargasso Sea Estimated from Seasonal Variations in Oxygen and Dissolved Inorganic Carbon

    Science.gov (United States)

    Ono, S.; Ennyu, A.; Najjar, R. G.; Bates, N.

    1998-01-01

    A diagnostic model of the mean annual cycles of dissolved inorganic carbon (DIC) and oxygen below the mixed layer at the Bermuda Atlantic Time-series Study (BATS) site is presented and used to estimate organic carbon remineralization in the seasonal thermocline. The model includes lateral and vertical advection as well as vertical, diffusion. Very good agreement is found for the remineralization estimates based on oxygen and DIC. Net remineralization averaged from mid-spring to early fall is found to be a maximum between 120 and 140 in. Remineralization integrated between 100 (the compensation depth) and 250 m during this period is estimated to be about 1 mol C/sq m. This flux is consistent with independent estimates of the loss of particulate and dissolved organic carbon.

  9. Development of techniques of production of sulfur-35 and its inorganic compounds

    International Nuclear Information System (INIS)

    Techniques to produce routinely Curies of carrier-free sulfur-35 from neutron irradiated potassium chloride were developed. Firstly the ratio of sulfur-35 to phosphorus-32 produced respectively by the reactions 35Cl(n,p)35S and 35Cl(n,α)32P was determined. For the post-irradiation process, two processes of anion exchange and cation exchange were studied. The former process was based on the selective elution of carrier-free sulfate after precipitation of the bulk of potassium chloride by ethanol and the latter process on the selective adsorption of carrier-free phosphate on Fe+3-cation exchange resin. A gloved box with various appendant equipments was constructed for routine production and a glass apparatus was installed in it. Sulfur-35 from 1 Ci to 5 Ci has been produced by the cation exchange process several times every year during past few years, and products of high quality have been obtained with yields higher than 90% without any troubles. In the studies on the synthesis of sulfur-35 labeled inorganic compounds, sulfate[35S] was reduced with tin(II)-phosphoric acid to hydrogen sulfide[35S], which was oxidized to elementary sulfur[35S]. Sulfate[35S] of sodium or copper(II) was precipitated from an aqueous solution of sodium or copper(II) chloride containing carrier-free sulfate [35S] by adding carrier of either one of the sulfates and ethanol. Copper(II) sulfate[35S] was pyrolyzed to evolve sulfur[35S] dioxide, which was fixed in a sodium hydroxide solution as sodium sulfite[35S]. This was allowed to react with colloidal sulfur in a boiling solution in the presence of 2-octanol to form thiosulfate[35S] efficiently. By treating target potassium chloride before and after irradiation in an oxygen-free atmosphere, approximately 60% of sulfur-35 was recovered as thiosulfate. Reduction with nascent hydrogen and decomposition with acid of the thiosulfate were studied to prepare elementary sulfur [35S]. (author)

  10. Combined effects of inorganic carbon and light on Phaeocystis globosa Scherffel (Prymnesiophyceae

    Directory of Open Access Journals (Sweden)

    H. J. W. de Baar

    2011-12-01

    Full Text Available Phaeocystis globosa (Prymnesiophyceae is a globally dominating phytoplankton species. It plays an important role in both the global sulfur and carbon cycles, by the production of dimethylsulfide (DMS and the drawdown of inorganic carbon. Phaeocystis globosa has a polymorphic life cycle and is considered to be a harmful algal bloom (HAB forming species. All these aspects make this an interesting species to study the effects of increasing carbon dioxide (CO2 concentrations, due to anthropogenic carbon emissions. Here, the combined effects of three different dissolved carbon dioxide concentrations (CO2(aq (low: 4 μmol kg−1, intermediate: 6–10 μmol kg−1 and high CO2(aq: 21–24 μmol kg−1 and two different light intensities (low light, suboptimal: 80 μmol photons m−2s–1 and high light, light saturated: 240 μmol photons m−2s−1 are reported. The experiments demonstrated that the specific growth rate of P. globosa in the high light cultures decreased with increasing CO2(aq from 1.4 to 1.1 d−1 in the low and high CO2 cultures respectively. Concurrently, the photosynthetic efficiency increased with increasing CO2(aq from 0.56 to 0.66. The different light conditions affected photosynthetic efficiency and chlorophyll-a concentrations, both of which were lower in the high light cultures as compared to the low light cultures. These results suggest that in the future, inorganic carbon enriched oceans, P. globosa will become less competitive and feedback mechanisms to global change may decrease in strength.

  11. Combined effects of inorganic carbon and light on Phaeocystis globosa Scherffel (Prymnesiophyceae

    Directory of Open Access Journals (Sweden)

    H. J. W. de Baar

    2012-05-01

    Full Text Available Phaeocystis globosa (Prymnesiophyceae is an ecologically dominating phytoplankton species in many areas around the world. It plays an important role in both the global sulfur and carbon cycles, by the production of dimethylsulfide (DMS and the drawdown of inorganic carbon. Phaeocystis globosa has a polymorphic life cycle and is considered to be a harmful algal bloom (HAB forming species. All these aspects make this an interesting species to study the effects of increasing carbon dioxide (CO2 concentrations, due to anthropogenic carbon emissions. Here, the combined effects of three different dissolved carbon dioxide concentrations (CO2(aq (low: 4 μmol kg−1, intermediate: 6–10 μmol kg−1 and high CO2(aq: 21–24 μmol kg−1 and two different light intensities (low light, suboptimal: 80 μmol photons m−2 s−1 and high light, light saturated: 240 μmol photons m−2 s−1 are reported. The experiments demonstrated that the specific growth rate of P. globosa in the high light cultures decreased with increasing CO2(aq from 1.4 to 1.1 d−1 in the low and high CO2 cultures, respectively. Concurrently, the photosynthetic efficiency (FV/FM increased with increasing CO2(aq from 0.56 to 0.66. The different light conditions affected photosynthetic efficiency and cellular chlorophyll a concentrations, both of which were lower in the high light cultures as compared to the low light cultures. These results suggest that in future inorganic carbon enriched oceans, P. globosa will become less competitive and feedback mechanisms to global change may decrease in strength.

  12. Carbon isotope fractionation of dissolved inorganic carbon (DIC) due to outgassing of carbon dioxide from a headwater stream

    Science.gov (United States)

    Doctor, D.H.; Kendall, C.; Sebestyen, S.D.; Shanley, J.B.; Ohte, N.; Boyer, E.W.

    2008-01-01

    The stable isotopic composition of dissolved inorganic carbon (??13C-DIC) was investigated as a potential tracer of streamflow generation processes at the Sleepers River Research Watershed, Vermont, USA. Downstream sampling showed ?? 13C-DIC increased between 3-5??? from the stream source to the outlet weir approximately 0??5 km downstream, concomitant with increasing pH and decreasing PCO2. An increase in ??13C-DIC of 2.4 ?? 0??1??? per log unit decrease of excess PCO2 (stream PCO2 normalized to atmospheric PCO2) was observed from downstream transect data collected during snowmelt. Isotopic fractionation of DIC due to CO2 outgassing rather than exchange with atmospheric CO2 may be the primary cause of increased ?? 13C-DIC values downstream when PCO2 of surface freshwater exceeds twice the atmospheric CO2 concentration. Although CO2 outgassing caused a general increase in stream ??13C-DIC values, points of localized groundwater seepage into the stream were identified by decreases in ??13C-DIC and increases in DIC concentration of the stream water superimposed upon the general downstream trend. In addition, comparison between snowmelt, early spring and summer seasons showed that DIC is flushed from shallow groundwater flowpaths during snowmelt and is replaced by a greater proportion of DIC derived from soil CO2 during the early spring growing season. Thus, in spite of effects from CO2 outgassing, ??13C of DIC can be a useful indicator of groundwater additions to headwater streams and a tracer of carbon dynamics in catchments. Copyright ?? 2007 John Wiley & Sons, Ltd.

  13. Microbial conversion of inorganic carbon to dimethyl sulfide in anoxic lake sediment (Plußsee, Germany

    Directory of Open Access Journals (Sweden)

    Y.-S. Lin

    2010-04-01

    Full Text Available In anoxic environments, volatile methylated sulfides including methanethiol (MT and dimethyl sulfide (DMS link the pools of inorganic and organic carbon with the sulfur cycle. However, direct formation of methylated sulfides from reduction of dissolved inorganic carbon has previously not been demonstrated. During examination of the hydrogenotrophic microbial activity at different temperatures in the anoxic sediment from Lake Plußsee, DMS formation was detected at 55 °C and was enhanced when bicarbonate was supplemented. Addition of both bicarbonate and H2 resulted in the strongest stimulation of DMS production, and MT levels declined slightly. Addition of methyl-group donors such as methanol and syringic acid or methyl-group acceptors such as hydrogen sulfide did not enhance further accumulation of DMS and MT. The addition of 2-bromoethanesulfonate inhibited DMS formation and caused a slight MT accumulation. MT and DMS had average δ13C values of −55‰ and −62‰, respectively. Labeling with NaH13CO3 showed that incorporation of bicarbonate into DMS occurred through methylation of MT. H235S labeling demonstrated a microbially-mediated, but slow, process of hydrogen sulfide methylation that accounted for <10% of the accumulation rates of DMS. Our data suggest: (1 methanogens are involved in DMS formation from bicarbonate, and (2 the major source of the 13C-depleted MT is neither bicarbonate nor methoxylated aromatic compounds. Other possibilities for isotopically light MT, such as demethylation of 13C-depleted DMS or other organic precursors such as methionine, are discussed. This DMS-forming pathway may be relevant for anoxic environments, such as hydrothermally influenced sediments and fluids and sulfate-methane transition zones in marine sediments.

  14. Carbonate concretions as a significant component of ancient marine carbon cycles: Insights from paired organic and inorganic carbon isotope analyses of a Cretaceous shale

    Science.gov (United States)

    Loyd, S. J.

    2014-12-01

    Carbonate concretions often occur within fine-grained, organic-rich sedimentary rocks. This association reflects the common production of diagenetic minerals through biologic cycling of organic matter. Chemical analysis of carbonate concretions provides the rare opportunity to explore ancient shallow diagenetic environments, which are inherently transient due to progressive burial but are an integral component of the marine carbon cycle. The late Cretaceous Holz Shale (~80 Ma) contains abundant calcite concretions that exhibit textural and geochemical characteristics indicative of relatively shallow formation (i.e., near the sediment-water interface). Sampled concretions contain between 5.4 and 9.8 wt.% total inorganic carbon (TIC), or ~45 and 82 wt.% CaCO3, compared to host shale values which average ~1.5 wt.% TIC. Organic carbon isotope compositions (δ13Corg) are relatively constant in host and concretion samples ranging from ­-26.3 to -24.0‰ (VPDB). Carbonate carbon isotope compositions (δ13Ccarb) range from -22.5 to -3.4‰, indicating a significant but not entirely organic source of carbon. Concretions of the lower Holz Shale exhibit considerably elevated δ13Ccarb values averaging -4.8‰, whereas upper Holz Shale concretions express an average δ13Ccarb value of -17.0‰. If the remaining carbonate for lower Holz Shale concretions is sourced from marine fluids and/or dissolved marine carbonate minerals (e.g., shells), a simple mass balance indicates that ~28% of concretion carbon was sourced from organic matter and ~72% from late Cretaceous marine inorganic carbon (with δ13C ~ +2.5‰). Upper Holz Shale calculations indicate a ~73% contribution from organic matter and a ~27% contribution from inorganic carbon. When normalized for carbonate, organic contents within the concretions are ~2-13 wt.% enriched compared to host contents. This potentially reflects the protective nature of cementation that acts to limit permeability and chemical destruction of

  15. Two decades of inorganic carbon dynamics along the West Antarctic Peninsula

    Science.gov (United States)

    Hauri, C.; Doney, S. C.; Takahashi, T.; Erickson, M.; Jiang, G.; Ducklow, H. W.

    2015-11-01

    We present 20 years of seawater inorganic carbon measurements collected along the western shelf and slope of the Antarctic Peninsula. Water column observations from summertime cruises and seasonal surface underway pCO2 measurements provide unique insights into the spatial, seasonal, and interannual variability in this dynamic system. Discrete measurements from depths > 2000 m align well with World Ocean Circulation Experiment observations across the time series and underline the consistency of the data set. Surface total alkalinity and dissolved inorganic carbon data showed large spatial gradients, with a concomitant wide range of Ωarag (end of the sampling grid and meltwater input along the coast towards the northern end. Large inorganic carbon drawdown through biological production in summer caused high near-shore Ωarag despite glacial and sea-ice meltwater input. In support of previous studies, we observed Redfield behavior of regional C / N nutrient utilization, while the C / P (80.5 ± 2.5) and N / P (11.7 ± 0.3) molar ratios were significantly lower than the Redfield elemental stoichiometric values. Seasonal salinity-based predictions of Ωarag suggest that surface waters remained mostly supersaturated with regard to aragonite throughout the study. However, more than 20 % of the predictions for winters and springs between 1999 and 2013 resulted in Ωarag < 1.2. Such low levels of Ωarag may have implications for important organisms such as pteropods. Even though we did not detect any statistically significant long-term trends, the combination of on-going ocean acidification and freshwater input may soon induce more unfavorable conditions than the ecosystem experiences today.

  16. Subsurface Monitor for Dissolved Inorganic Carbon at Geological Sequestration Site Phase 1 SBIR Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Sheng Wu

    2012-08-03

    Phase I research of this SBIR contract has yielded anticipated results and enable us to develop a practical new instrument to measure the Dissolved Inorganic Carbons (DIC) as well as Supercritical (SC) CO2 in underground brine water at higher sensitivity, lower cost, higher frequency and longer period of time for the Monitoring, Verification & Accounting (MVA) of CO2 sequestration as well as Enhanced Oil Recovery (EOR). We show that reduced cost and improved performance are possible; both future and emerging market exist for the proposed new instrument.

  17. Dissolved inorganic carbon dynamics in the waters surrounding forested mangroves of the Ca Mau Province (Vietnam)

    OpenAIRE

    Koné, J. M.; Borges, Alberto

    2008-01-01

    Dissolved inorganic carbon (DIC) and ancillary data were obtained during the dry and rainy seasons in the waters surrounding two 10-year-old forested mangrove sites (Tam Giang and Kien Vang) located in the Ca Mau Province (South-West Vietnam). During both seasons, the spatial variations of partial pressure of CO2 (pCO2) were marked, with values ranging from 704 ppm to 11481 ppm during the dry season, and from 1209 ppm to 8136 ppm during the rainy season. During both seasons, DIC, pCO2, total ...

  18. The one-dimensional organic inorganic hybrid compound poly[(diethylenetriamine)tetra-μ-iodido-dilead(II)

    OpenAIRE

    Abid, Y; Driss, A.; Boughzala, H.; E. Samet Kallel

    2008-01-01

    A new organic–inorganic hybrid, [Pb2I4(C4H13N3)]n, was obtained by the reaction of C4N3H10 and PbI2 at room temperature. The structure is a three-dimensional polymer resulting from the association of PbI6 octahedra and a mixed lead organic–inorganic PbI4(C4N3H13) coordination polyhedron. Both Pb atoms, two I atoms and one N atom lie on a mirror plane. N—H...I hydrogen bonds further connect the organic unit and some I atoms.

  19. High-rate nitrogen removal by the Anammox process with a sufficient inorganic carbon source.

    Science.gov (United States)

    Yang, Jiachun; Zhang, Li; Fukuzaki, Yasuhiro; Hira, Daisuke; Furukawa, Kenji

    2010-12-01

    This study focused on high-rate nitrogen removal by the anaerobic ammonium oxidation (Anammox) process with a sufficient inorganic carbon (IC) source. Experiments were carried out in an up-flow column Anammox reactor fed with synthetic inorganic wastewater for 110 days. The IC source was added into the influent tank in the form of bicarbonate. The results confirmed the positive impact of inorganic matter on stimulating Anammox activity. After the addition of sufficient IC, the nitrogen removal rate sharply increased from 5.2 to 11.8 kg-Nm(-3)day(-1) within only 32 days. NO(2)-N inhibition was not observed even at NO(2)-N concentrations greater than 460 mgN/L, indicating the enriched Anammox consortium adapted to high NO(2)-N concentrations. The ratio of NO(2)-N removal, NO(3)-N production and NH(4)-N removal for the reactor was correspondingly changed from 1.21:0.21:1 to 1.24:0.18:1. Simultaneously, the sludge volume index of the Anammox granules decreased markedly from 36.8 to 21.5 mL/g, which was attributed to the implementation of proper operational strategy. In addition, DNA analysis revealed that a shift from the KSU-1 strain to the KU2 strain occurred in the Anammox community. PMID:20709538

  20. Integration of inorganic nanostructures with polydopamine-derived carbon: tunable morphologies and versatile applications

    Science.gov (United States)

    Kong, Junhua; Seyed Shahabadi, Seyed Ismail; Lu, Xuehong

    2016-01-01

    Polydopamine (PDA), a mussel adhesive-inspired biomimetic polymer, has attracted tremendous attention owing to its extremely versatile adhesion properties, facile aqueous coating process, capability of self-assembly to form nanostructures, and abundant surface functional groups for secondary modification. PDA is also a fantastic carbon source because it gives nitrogen (N)-doped graphite-like carbon in high yield, and the carbonized PDA (C-PDA) thin coatings have similar properties to those of N-doped multilayered graphene, i.e., they exhibit high electrical conductivity, and good electrochemical and mechanical properties. In comparison with other carbon sources, an outstanding feature of PDA lies in its ease of integration with inorganic nanostructures and capability for easy tailoring the structure and morphology of the resultant composite nanostructures. In this article, different routes for the preparation of C-PDA-based composite nanostructures, such as carbon/metal oxide and carbon/Si hollow, mesoporous, core-shell, yolk-shell nanostructures, are introduced with typical examples. The structures, morphologies and properties of the C-PDA-based composite nanostructures are also reviewed, and their potential applications in various engineering fields, such as energy storage, solar water splitting, flexible electronics, catalysis, sensing and environmental engineering, are highlighted. Finally a future outlook for this fascinating composite-nanostructure enabler is also presented.

  1. Microbial conversion of inorganic carbon to dimethyl sulfide in anoxic lake sediment (Plußsee, Germany

    Directory of Open Access Journals (Sweden)

    Y. S. Lin

    2010-08-01

    Full Text Available In anoxic environments, volatile methylated sulfides like methanethiol (MT and dimethyl sulfide (DMS link the pools of inorganic and organic carbon with the sulfur cycle. However, direct formation of methylated sulfides from reduction of dissolved inorganic carbon has previously not been demonstrated. When studying the effect of temperature on hydrogenotrophic microbial activity, we observed formation of DMS in anoxic sediment of Lake Plußsee at 55 °C. Subsequent experiments strongly suggested that the formation of DMS involves fixation of bicarbonate via a reductive pathway in analogy to methanogenesis and engages methylation of MT. DMS formation was enhanced by addition of bicarbonate and further increased when both bicarbonate and H2 were supplemented. Inhibition of DMS formation by 2-bromoethanesulfonate points to the involvement of methanogens. Compared to the accumulation of DMS, MT showed the opposite trend but there was no apparent 1:1 stoichiometric ratio between both compounds. Both DMS and MT had negative δ13C values of −62‰ and −55‰, respectively. Labeling with NaH13CO3 showed more rapid incorporation of bicarbonate into DMS than into MT. The stable carbon isotopic evidence implies that bicarbonate was fixed via a reductive pathway of methanogenesis, and the generated methyl coenzyme M became the methyl donor for MT methylation. Neither DMS nor MT accumulation were stimulated by addition of the methyl-group donors methanol and syringic acid or by the methyl-group acceptor hydrogen sulphide. The source of MT was further investigated in a H235S labeling experiment, which demonstrated a microbially-mediated process of hydrogen sulfide methylation to MT that accounted for only <10% of the accumulation rates of DMS. Therefore, the major source of the 13C-depleted MT was neither bicarbonate nor methoxylated aromatic compounds. Other possibilities for

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

    DEFF Research Database (Denmark)

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

    2008-01-01

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

  3. Metal organophosphonates and their intercalation compounds as inorganic-organic hydrid materials and nanomaterials

    Czech Academy of Sciences Publication Activity Database

    Zima, Vítězslav; Svoboda, Jan; Melánová, Klára; Beneš, L.

    Ostrava : VŠB Technical University of Ostrava, 2008, s. 12-12. ISBN 978-80-7329-190-7. [Nano Ostrava 2008. Ostrava (CZ), 01.09.2008-04.09.2008] R&D Projects: GA ČR(CZ) GA203/08/0208 Institutional research plan: CEZ:AV0Z40500505 Keywords : intercalation Subject RIV: CA - Inorganic Chemistry

  4. Effect of carbon dioxide and bicarbonate as inorganic carbon sources on growth and adaptation of autohydrogenotrophic denitrifying bacteria

    International Nuclear Information System (INIS)

    Acclimation of autohydrogenotrophic denitrifying bacteria using inorganic carbon source (CO2 and bicarbonate) and hydrogen gas as electron donor was performed in this study. In this regard, activated sludge was used as the seed source and sequencing batch reactor (SBR) technique was applied for accomplishing the acclimatization. Three distinct strategies in feeding of carbon sources were applied: (I) continuous sparging of CO2, (II) bicarbonate plus continuous sparging of CO2, and (III) only bicarbonate. The pH-reducing nature of CO2 showed an unfavorable impact on denitrification rate; however bicarbonate resulted in a buffered environment in the mixed liquor and provided a suitable mean to maintain the pH in the desirable range of 7-8.2. As a result, bicarbonate as the only carbon source showed a faster adaptation, while carbon dioxide as the only carbon source as well as a complementary carbon source added to bicarbonate resulted in longer acclimation period. Adapted hydrogenotrophic denitrifying bacteria, using bicarbonate and hydrogen gas in the aforementioned pH range, caused denitrification at a rate of 13.33 mg NO3--N/g MLVSS/h for degrading 20 and 30 mg NO3--N/L and 9.09 mg NO3--N/g MLVSS/h for degrading 50 mg NO3--N/L

  5. Coupled transformation of inorganic stable carbon-13 and nitrogen-15 isotopes into higher trophic levels in a eutrophic shallow lake

    International Nuclear Information System (INIS)

    Enclosure and bag experiments were done in a eutrophic shallow lake with simultaneous use of inorganic 13C and 15N isotopes. It was demonstrated that coupled transformation of inorganic carbon and nitrogen can occur into herbivorous zooplankton through phytoplankton. Direct evidence is provided that there is an apparent coupling between photosynthesis and organic nitrogen uptake by phytoplankton during daytime under natural conditions and that the coupling occurs at a constant ratio

  6. Regeneration of spent powdered activated carbon saturated with inorganic ions by cavitation united with ion exchange method.

    Science.gov (United States)

    Li, Gang; Gao, Hong; Li, Yansheng; Yang, Huixin

    2011-06-01

    Using ion exchange resin as transfer media, regenerate powdered activated carbon (PAC) adsorbed inorganic ions by cavitation to enhance the transfer; we studied how the regeneration time and the mass ratio of resin and PAC influence the regeneration rate respectively through re-adsorption. The result showed that the effective regeneration of PAC saturated with inorganic ions was above 90% using ion exchange resin as media and transfer carrier, the quantity of PAC did not reduced but activated in the process. PMID:25084579

  7. Application of radioisotopes to the investigation of the kinetics and mechanism of reactions of some inorganic complex compounds

    International Nuclear Information System (INIS)

    Radioisotopes are invaluable tools in the study of many types of inorganic chemical reactions, particularly those involving complex ionic substances in aqueous solution. One important approach is through research on the rates and mechanisms of isotopic exchange processes. For example, a series of studies has been made of the exchange between carbon-14-labelled ''free'' carbonate and the ligand carbonate in octahedral complex ions of the type CoA2CO3+, where A = 2 NH3, ethylenediamine (en), propylenediamine (pn), or trimethylenediamine (tn). These studies have led to a rather thorough understanding of the nature of this kind of ligand substitution reaction, and of the part played by the non-exchanging amine ligands in the process. Similar studies of oxalate exchange with tris-oxalato complexes of the form M (C2O4)3-3, where M = Co (III), Cr (III), or Rh (III), have been equally fruitful. An alternative technique, applicable only when using low-atomic-weight radioisotopes such as carbon-14, is to observe the equilibrium or kinetic isotope effects in the reaction of interest. I t has, for instance, been possible to interpret differences in the ligand carbonate exchange mechanism of Coen2CO3+ and Cotn2CO3+ on the basis of equilibrium isotope-effect measurements made on the carbonate exchange reaction. Similarly, data on the kinetic isotope effect in the acid-catalysed aquation of the Co (NH3)4CO3+ ion has supported deductions as to the nature of the rate-determining bond-breakage step in such reactions. Finally, the mechanistic path of certain atoms or radicals in inorganic reactions, where a choice between alternative explanations must be made, is frequently facilitated by a radioactive tracer experiment. An example is the proof that cyanide does not appear as a rapidly exchanging intermediate in the oxidation of thiocyanate ion by hydrogen peroxide, although cyanide is an important end-product. (author)

  8. Types of cationic complexes based on oxocentred tetrahedra [OM4] in the crystal structures of inorganic compounds

    International Nuclear Information System (INIS)

    The crystal structures of inorganic compounds comprising cationic complexes containing oxygen atoms coordinated tetrahedrally to metal atoms, or oxocentred groups [OM4], are considered. The linking of the [OM4] tetrahedra in the structures has been analysed and cationic complexes of different structures have been identified. The rules governing the linking of the [OM4] tetrahedra have been formulated and the cationic complexes have been subjected to a detailed systematic treatment on their basis. Data on the statistics of the bond lengths and bond angles in the [OM4] tetrahedra are presented. The bibliography includes 317 references.

  9. Study on the Built-up Effect of Inorganic Compounds to Flame Retardant Containing Organophosphorus in Suppression of Smoke

    Institute of Scientific and Technical Information of China (English)

    LIN Miao; XIAN Chun-ying; YANG Yong

    2006-01-01

    The built-up effect of inorganic compounds containing more active metal ions, such as Ca2+ , Al3+ , Cu2+ , and Zn2+ , as additives adding to phosphorus-containing flame retarding systems in suppression of smoke was studied. The data presented herein suggested that the amount of smoke in the burning process can be better suppressed after the cotton fabric finishing with built- up system was burnt. Some general principles were identified, and the likely causes of the observed effects were analyzed according to test data.

  10. Physiological conditions and uptake of inorganic carbon-14 by plant roots

    International Nuclear Information System (INIS)

    The uptake of inorganic 14C by bean plant roots was measured. The plants were grown in a nutrient solution culture at pH 6 and a NaH14CO3 tracer was added to the growth medium. Photosynthesis and transpiration were varied by exposing the aerial portions of the plants to different atmospheric CO2 concentrations, humidities and light levels in a cuvette system. Leaf concentrations of 14C were measured at the end of the experiments using liquid scintillation counting. Plant uptake of 14C via the roots was independent of the photosynthetic rate and, in most cases, could be predicted by knowing the transpiration rate and the nutrient solution concentration. However, when a less efficient root-medium aeration system was used, 14C uptake was greater than that predicted using transpiration, a phenomenon observed by other researchers. This contrasted to results of another experiment where the measured uptake of iodine was much slower than that predicted using transpiration. Knowledge of transpiration rates is useful in predicting inorganic carbon uptake via the roots and in estimating 14C transport from contaminated soils to biota. Also, the independence of the uptake from photosynthesis and ambient CO2 concentrations suggests that future increases in atmospheric CO2 concentrations may not have a direct effect on root uptake of soil carbon. (author)

  11. Recently fixed carbon allocation in strawberry plants and concurrent inorganic nitrogen uptake through arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Tomè, Elisabetta; Tagliavini, Massimo; Scandellari, Francesca

    2015-05-01

    Most crop species form a symbiotic association with arbuscular mycorrhizal (AM) fungi, receiving plant photosynthate and exchanging nutrients from the soil. The plant carbon (C) allocation to AM fungi and the nitrogen feedback are rarely studied together. In this study, a dual (13)CO2 and (15)NH4(15)NO3 pulse labeling experiment was carried out to determine the allocation of recent photosynthates to mycorrhizal hyphae and the translocation of N absorbed by hyphae to strawberry plants. Plants were grown in pots in which a 50 μm mesh net allowed the physical separation of the mycorrhizal hyphae from the roots in one portion of the pot. An inorganic source of (15)N was added to the hyphal compartment at the same time of the (13)CO2 pulse labeling. One and seven days after pulse labeling, the plants were destructively harvested and the amount of the recently fixed carbon (C) and of the absorbed N was determined. (13)C allocated to belowground organs such as roots and mycorrhizal hyphae accounted for an average of 10%, with 4.3% allocated to mycorrhizal hyphae within the first 24h after the pulse labeling. Mycorrhizae absorbed labeled inorganic nitrogen, of which almost 23% was retained in the fungal mycelium. The N uptake was linearly correlated with the (13)C fixed by the plants suggesting a positive correlation between a plant photosynthetic rate and the hyphal absorption capacity. PMID:25841208

  12. Carbon compound used in hydrogen storage

    International Nuclear Information System (INIS)

    In the present work it is studied the activated carbon of mineral origin for the sorption of hydrogen. The carbon decreased of particle size by means of the one alloyed mechanical. The time of mill was of 10 hours. The characterization one carries out by scanning electron microscopy and X-ray diffraction. The hydrogen sipped in the carbon material it was determined using the Thermal gravimetric method (TGA). The conditions of hydrogenation went at 10 atm of pressure and ambient temperature during 18 hours. They were also carried out absorption/desorption cycles of hydrogen in the same one system of thermal gravimetric analysis. The results showed percentages of sorption of 2% approximately in the cycles carried out in the system TGA and of 4.5% in weight of hydrogen at pressure of 10 atmospheres and ambient temperature during 18 hours. (Author)

  13. Atmospheric Mg2+ wet deposition within the continental United States and implications for soil inorganic carbon sequestration

    OpenAIRE

    Goddard, Megan A.; Mikhailova, Elena A.; Post, Christopher J.; Schlautman, Mark A.

    2011-01-01

    Little is known about atmospheric magnesium ion (Mg2+) wet deposition in relation to soil inorganic carbon sequestration. Understanding the conversion of carbon dioxide (CO2) or organic carbon to a form having a long residence time within the soil (e.g., dolomite, magnesian calcite) will greatly benefit agriculture, industry, and society on a global scale. This preliminary study was conducted to analyze atmospheric Mg2+ wet deposition within the continental United States (U.S.) and to rank th...

  14. A curved multi-component aerosol hygroscopicity model framework: Part 1 – Inorganic compounds

    Directory of Open Access Journals (Sweden)

    D. O. Topping

    2005-01-01

    Full Text Available A thermodynamic modelling framework to predict the equilibrium behaviour of mixed inorganic salt aerosols is developed, and then coupled with a technique for finding a solution to the Kohler equation in order to create a diameter dependent hygroscopic aerosol model (Aerosol Diameter Dependent Equilibrium Model – ADDEM. The model described here provides a robust and accurate inorganic basis using a mole fraction based activity coefficient model and adjusted energies of formation for treating solid precipitation. The model framework can accommodate organic components, though this added complexity is considered in a companion paper, this paper describes the development of the modelling architecture to be used and predictions of an inorganic model alone. The modelling framework has been developed to flexibly use a combination of mixing rules and other potentially more accurate techniques where available to calculate the water content. Comparisons with other state-of-the-art general equilibrium models and experimental data are presented and show excellent agreement. The Kelvin effect can be considered in this scheme using a variety of surface tension models. Comparison of predicted diameter dependent phenomena, such as the increased relative humidity for onset of deliquescence with decreasing diameter, with another diameter dependent model is very good despite the different approach used. The model is subject to various sensitivities. For the inorganic systems studied here, the model is sensitive to choice of surface tension scheme used, which decreases for larger aerosol. Large sensitivities are found for the value of dry density used. It is thus likely that the history of the aerosol studied in a hygroscopic tandem differential mobility analyser (HTDMA, specifically the nature of the drying process that will influence the final crystalline form, will create systematic uncertainties upon comparisons with theoretical predictions. However, the

  15. Characterization of inorganic compounds in nutritional supplements by the instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    In this work instrumental neutron activation analysis was applied in the analyses of samples of nutritional supplements in order to evaluate the composition of their essential inorganic components. Results obtained in these analyses presented, in general, a good agreement with the label values. Precision and accuracy of the results were also evaluated by analyzing NIST 2704 Buffalo River Sediment and NIST 1400 Bone Ash reference materials. (author)

  16. Composition and leaching of construction and demolition waste: Inorganic elements and organic compounds

    DEFF Research Database (Denmark)

    Butera, Stefania; Christensen, Thomas Højlund; Astrup, Thomas Fruergaard

    2014-01-01

    Thirty-three samples of construction and demolition waste collected at 11 recycling facilities in Denmark were characterised in terms of total content and leaching of inorganic elements and presence of the persistent organic pollutants PCBs and PAHs. Samples included (i) "clean" (i.e. unmixed...... segregation and management practices may be important. Generally, leaching was in compliance with available leaching limits, except for selenium, and in some cases chromium, sulphate and antimony. © 2014 Elsevier B.V....

  17. Design of non-linear optical materials based on inorganic compounds

    OpenAIRE

    Lamberth, Curt.; Mingos, D. M. P.; Dr. Mike Mingos

    1992-01-01

    This Thesis is concerned with the prediction, synthesis, characterization and testing of inorganic materials for Second Harmonic Generation (SHG). Chapter One describes the fundamentals of non-linear optics, and poses the problems, and some of their solutions which confront the synthetic chemist and the theoretical prediction of the second order hyperpolarizability constant β using CNDOVSB calculations. Chapter Two describes the design, implementation and calibration of an a...

  18. Inorganic carbon fluxes across the vadose zone of planted and unplanted soil mesocosms

    Directory of Open Access Journals (Sweden)

    E. M. Thaysen

    2014-03-01

    Full Text Available The efflux of carbon dioxide (CO2 from soils influences atmospheric CO2 concentrations and thereby climate change. The partitioning of inorganic carbon fluxes in the vadose zone between emission to the atmosphere and to the groundwater was investigated. Carbon dioxide partial pressure in the soil gas (pCO2, alkalinity, soil moisture and temperature were measured over depth and time in unplanted and planted (barley mesocosms. The dissolved inorganic carbon (DIC percolation flux was calculated from the pCO2, alkalinity and the water flux at the mesocosm bottom. Carbon dioxide exchange between the soil surface and the atmosphere was measured at regular intervals. The soil diffusivity was determined from soil radon-222 (222Rn emanation rates and soil air Rn concentration profiles, and was used in conjunction with measured pCO2 gradients to calculate the soil CO2 production. Carbon dioxide fluxes were modelled using the HP1 module of the Hydrus 1-D software. The average CO2 effluxes to the atmosphere from unplanted and planted mesocosm ecosystems during 78 days of experiment were 0.1 ± 0.07 and 4.9 ± 0.07 μmol carbon (C m−2 s−1, respectively, and largely exceeded the corresponding DIC percolation fluxes of 0.01 ± 0.004 and 0.06 ± 0.03 μmol C m−2 s−1. Post-harvest soil respiration (Rs was only 10% of the Rs during plant growth, while the post-harvest DIC percolation flux was more than one third of the flux during growth. The Rs was controlled by production and diffusivity of CO2 in the soil. The DIC percolation flux was largely controlled by the pCO2 and the drainage flux due to low solution pH. Plant biomass and soil pCO2 were high in the mesocosms as compared to a standard field situation. Our results indicate no change of the cropland C balance under elevated atmospheric CO2 in a warmer future climate, in which plant biomass and soil pCO2 are expected to increase.

  19. Inorganic carbon parameters responding to summer hypoxia outside the Changjiang Estuary and the related implications

    Science.gov (United States)

    Wang, Bin; Chen, Jianfang; Jin, Haiyan; Li, Hongliang; Xu, Jie

    2013-12-01

    The eutrophication, hypoxia and coastal acidification are attracting more and more attention. In this study, inorganic carbon parameters, including dissolved inorganic carbon (DIC), total alkalinity (TA) and calculated partial pressure of CO2 ( pCO2), obtained from a summer cruise in August, 2009, were used to investigate their integrated response to biological processes accompanying the oxygen depletion in the areas off the Changjiang Estuary. According to the observations, the typical hypoxia occurred in the bottom water just outside the Changjiang Estuary with Dissolved Oxygen (DO) lower than 2.00 mg L-1. The biological uptake in the surface water and the decomposition of organic matter in the bottom water were fully coupled with each other. The high concentration of Chl_ a (Chl_ a = 10.9 μg L-1) and DO (9.25 mg L-1), profoundly decreased DIC concentration (1828 μmol kg-1) and elevated pH (8.42) was observed in the surface water. The correspondingly increased DIC and depletion of oxygen were observed in the bottom water. The semi-quantitative analysis proved that the locally-produced phytoplankton, determined by primary productivity, was deposited to the bottom and contributed about 76% of total amount of the organic carbon decomposition in the bottom. However, in the bottom hypoxia (DO = 2.05 mg L-1) area observed in the Southern Zhejiang coastal water, the responding patterns of inorganic carbon parameters deviated from the previous one. The expanding of Changjiang Diluted Water (CDW), the adding of Hangzhou Bay water (with high DIC concentration) and Coastal Current together modify the DIC background value in this area, and the local degeneration and upwelling process may also help to offset the local DIC removed by net biological uptake in surface water. In addition, when the mixing occurring in autumn, which may break the summer stratification, the excess release of high DIC in the bottom water to the subsurface water could have an important influence on

  20. Inorganic Carbon Cycling and Biogeochemical Processes in an Arctic Inland Sea (Hudson Bay)

    Science.gov (United States)

    Burt, William; Thomas, Helmuth; Miller, Lisa; Granskog, Mats; Papakyriakou, Tim; Pengelly, Leah

    2016-04-01

    The distributions of CO2 system parameters in Hudson Bay, which not only receives nearly one third of Canada's river discharge, but is also subject to annual cycles of sea-ice formation and melt, indicate that the timing and magnitude of freshwater inputs play an important role in carbon biogeochemistry and ocean acidification in this unique Arctic ecosystem. This study uses basin-wide measurements of dissolved inorganic carbon (DIC) and total alkalinity (TA), as well as stable isotope tracers (δ18OH2O and δ13CDIC), to provide a detailed assessment of carbon cycling processes throughout the bay. Surface distributions of carbonate parameters reveal the particular importance of freshwater inputs in the southern portion of the bay. Riverine TA end-members vary significantly both regionally and with small changes in near-surface depths, highlighting the importance of careful surface water sampling in highly stratified waters. In an along-shore transect, large increases in subsurface DIC are accompanied by equivalent decreases in δ13CDIC with no discernable change in TA, indicating a respiratory DIC production on the order of 100 μmol/kg during deep water circulation around the bay. Based on TA data we surmise that the deep waters in the Hudson Bay are of Pacific origin.

  1. Corrosion Protection of Carbon Steel Using Poly aniline Composite with Inorganic Pigments

    International Nuclear Information System (INIS)

    Two inorganic pigments (TiO2 and SiO2) were used to prepare composites with poly aniline (PANI) by situ polymerization method. PANI and PANI composites with SiO2 and TiO2 were characterized using Fourier transform infrared spectroscopy and X-ray diffraction. The morphology of the synthesized pigments (PANI , PANI-SiO2 and PANI-TiO2) was examined using scanning electron microscopy. Samples were then used as pigments through blending them with acrylic paint and applied on the surface of carbon steel panels. Corrosion was evaluated for coating of carbon steel panels through full immersion test up to standard ASTMG 31. Mass loss was calculated after they have been exposed in acidic media. A digital camera was also used for monitoring corrosion visually on the surface of carbon steel specimens. The results revealed that acrylic paint pigmented by PANI-SiO2 composite was more efficient in corrosion protection for carbon steel compared with the other synthesized pigments. (author)

  2. Determination of the δ13C of dissolved inorganic carbon in water; RSIL lab code 1710

    Science.gov (United States)

    Singleton, Glenda L.; Revesz, Kinga; Coplen, Tyler B.

    2012-01-01

    The purpose of the Reston Stable Isotope Laboratory (RSIL) lab code 1710 is to present a method to determine the δ13C of dissolved inorganic carbon (DIC) of water. The DIC of water is precipitated using ammoniacal strontium chloride (SrCl2) solution to form strontium carbonate (SrCO3). The δ13C is analyzed by reacting SrCO3 with 100-percent phosphoric acid (H3PO4) to liberate carbon quantitatively as carbon dioxide (CO2), which is collected, purified by vacuum sublimation, and analyzed by dual inlet isotope-ratio mass spectrometry (DI-IRMS). The DI-IRMS is a DuPont double-focusing mass spectrometer. One ion beam passes through a slit in a forward collector and is collected in the rear collector. The other measurable ion beams are collected in the front collector. By changing the ion-accelerating voltage under computer control, the instrument is capable of measuring mass/charge (m/z) 45 or 46 in the rear collector and m/z 44 and 46 or 44 and 45, respectively, in the front collector. The ion beams from these m/z values are as follows: m/z 44 = CO2 = 12C16O16O, m/z 45 = CO2 = 13C16O16O primarily, and m/z 46 = CO2 = 12C16O18O primarily. The data acquisition and control software calculates δ13C values.

  3. The impact of CO2 on inorganic carbon supply and pH homeostasis in Corynebacterium glutamicum

    OpenAIRE

    Kirsch, Katja Meike

    2014-01-01

    The actinobacterium C. glutamicum is a soil bacterium which is extensively used in biotechnology, especially in the production of L-glutamate and L-lysine. An important aspect of industrial scale fermentation processes with high cell densities is the formation of large amounts of CO2. Since CO2 is assumed to influence inorganic carbon provision as well as the internal pH of C. glutamicum, both aspects were investigated in this study. For a sufficient supply with inorganic carbon, the ß-type c...

  4. Inorganic carbon fluxes across the vadose zone of planted and unplanted soil mesocosms

    Science.gov (United States)

    Thaysen, E. M.; Jacques, D.; Jessen, S.; Andersen, C. E.; Laloy, E.; Ambus, P.; Postma, D.; Jakobsen, I.

    2014-12-01

    The efflux of carbon dioxide (CO2) from soils influences atmospheric CO2 concentrations and thereby climate change. The partitioning of inorganic carbon (C) fluxes in the vadose zone between emission to the atmosphere and to the groundwater was investigated to reveal controlling underlying mechanisms. Carbon dioxide partial pressure in the soil gas (pCO2), alkalinity, soil moisture and temperature were measured over depth and time in unplanted and planted (barley) mesocosms. The dissolved inorganic carbon (DIC) percolation flux was calculated from the pCO2, alkalinity and the water flux at the mesocosm bottom. Carbon dioxide exchange between the soil surface and the atmosphere was measured at regular intervals. The soil diffusivity was determined from soil radon-222 (222Rn) emanation rates and soil air Rn concentration profiles and was used in conjunction with measured pCO2 gradients to calculate the soil CO2 production. Carbon dioxide fluxes were modeled using the HP1 module of the Hydrus 1-D software. The average CO2 effluxes to the atmosphere from unplanted and planted mesocosm ecosystems during 78 days of experiment were 0.1 ± 0.07 and 4.9 ± 0.07 μmol C m-2 s-1, respectively, and grossly exceeded the corresponding DIC percolation fluxes of 0.01 ± 0.004 and 0.06 ± 0.03 μmol C m-2 s-1. Plant biomass was high in the mesocosms as compared to a standard field situation. Post-harvest soil respiration (Rs) was only 10% of the Rs during plant growth, while the post-harvest DIC percolation flux was more than one-third of the flux during growth. The Rs was controlled by production and diffusivity of CO2 in the soil. The DIC percolation flux was largely controlled by the pCO2 and the drainage flux due to low solution pH. Modeling suggested that increasing soil alkalinity during plant growth was due to nutrient buffering during root nitrate uptake.

  5. Hibiscus Rosa Sinensis Leaves: Analysis Of Proximate, Antioxidant Activities And Inorganic Compound

    International Nuclear Information System (INIS)

    A variety of herbal plants species has been used in traditional medicine. Most of these plants contained several potent bio-active ingredients and nutrients that could give potential positive effects to the health such as antioxidant and antipyretic. Hibiscus rosa sinensis, commonly known as Bunga raya, have similar concoction characteristic to tea which contain antioxidants that help to control cholesterol. In addition, mucilage that was found in the leaves could helps to reduce extreme body heat during fever (which potentially acts as an antipyretic). Therefore, this preliminary study on the fresh and dried H. rosa sinensis leaves was carried out to analyze and identify the nutrients content, anti-oxidants and inorganic material. Total phenolic content (TPC) method was used for both fresh and dried leaves prior to the antioxidant activities of DPPH free radicals scavenging and ferric ion reducing antioxidant power (FRAP) as to confirm the existence of antioxidant constituents. Meanwhile, the composition of heavy metals was studied using inductively coupled plasma mass spectrometry (ICP-MS). The proximate analysis of the fresh leaves showed the presence of moisture content (9.03 %), protein (10.44 %), fat (6.43 %), crude fiber (11.55 %), ash (11.22 %) and carbohydrate (51.33 %). Meanwhile, the inorganic contents are as follows: cadmium (Cd), chromium (Cr), arsenic (As), nickel (Ni), lead (Pb), iron (Fe) and zinc (Zn). Furthermore, the antioxidant activities of FRAP and DPPH showed that dried leaves of H. rosa sinensis was higher than the fresh leaves (p < 0.05) irrespective of any solvent used. The positive correlation between TPC and two other antioxidant activities of DPPH and FRAP (p < 0.05) indicates the presence of antioxidant components in the acetone and water extracts. Therefore, the high availability of essential nutritional component, anti-oxidants and low concentration of hazardous inorganic matter in H. rosa sinensis leaves enable it to be used as one

  6. Inorganic carbon cycle in soil-rock-groundwater system in karst and fissured aquifers

    Directory of Open Access Journals (Sweden)

    Ajda Koceli

    2013-12-01

    Full Text Available The paper presents a systematic analysis of the isotopic composition of carbon (δ13CCaCO3 in carbonate rocks in central Slovenia, representing karst and fissured aquifers, and share of carbon contributions from carbonate dissolution and degradation of organic matter in aquifers, calculated from the mass balance equation. 59 samples of rocks (mainly dolomites from Upper Permian to Upper Triassic age were analyzed. Samples of carbonate rocks were pulverized and ground to fraction of 45 μm and for determination of δ13CCaCO3 analyzed with mass spectrometer for analyses of stable isotopes of light elements-IRMS. The same method was used for determination of isotopic composition of dissolved inorganic carbon (δ13CDIC in groundwater for 54 of 59 locations. Values of δ13CCaCO3 are in the range from -2.0 ‰ to +4.1 ‰, with an average δ13CCaCO3 value of +2.2 ‰. These values are typical for marine carbonates with δ13CCaCO3 around 0 ‰, although δ13CCaCO3 values differ between groups depending on the origin and age. Early diagenetic dolomites have relatively higher values of δ13CCaCO3 compared to other analyzed samples. The lowest values of δ13CCaCO3 were observed in Cordevolian and Bača dolomite, probably due to late diagenesis, during which meteoric water with lower isotopic carbon composition circulated in the process of sedimentation. Values of δ13CDIC range from -14.6 ‰ to -8.2 ‰. Higher δ13CDIC values (-8.2 ‰ indicate a low proportion of soil CO2 in the aquifer and rapid infiltration, while lower values (-14.6 ‰ indicate higher proportion of soil CO2 in the aquifer and slower infiltration. Calculated contributions of carbon from organic matter / dissolution of carbonates in the karstic and fissured aquifers s how a similar proportion (50 % : 50 %.

  7. Stoichiometric Analysis of Inorganic Compounds Using Laser-Induced Breakdown Spectroscopy with Gated and Nongated Spectrometers

    OpenAIRE

    Sreedhar Sunku; Ashwin Kumar Myakalwar; Manoj Kumar Gundawar; Prem Kiran Paturi; Surya Praksh Tewari; Venugopal Rao Soma

    2012-01-01

    We describe our results obtained from stoichiometric ratio studies of three different energetic, inorganic samples (ammonium perchlorate (AP), boron potassium nitrate (BPN), and ammonium nitrate (AN)) using the technique of laser-induced breakdown spectroscopy (LIBS) with nanosecond pulses. Signal collection was independently executed using both gated and nongated spectrometers. The oxygen peak at 777.31 nm (O) and nitrogen peaks at 742.50 nm (N1), 744.34 nm (N2), and 746.91 nm (N3) were used...

  8. Geochemistry of dissolved inorganic carbon in a Coastal Plain aquifer. 2. Modeling carbon sources, sinks, and δ13C evolution

    Science.gov (United States)

    McMahon, Peter B.; Chapelle, Francis H.

    1991-01-01

    Stable isotope data for dissolved inorganic carbon (DIC), carbonate shell material and cements, and microbial CO2 were combined with organic and inorganic chemical data from aquifer and confining-bed pore waters to construct geochemical reaction models along a flowpath in the Black Creek aquifer of South Carolina. Carbon-isotope fractionation between DIC and precipitating cements was treated as a Rayleigh distillation process. Organic matter oxidation was coupled to microbial fermentation and sulfate reduction. All reaction models reproduced the observed chemical and isotopic compositions of final waters. However, model 1, in which all sources of carbon and electron-acceptors were assumed to be internal to the aquifer, was invalidated owing to the large ratio of fermentation CO2 to respiration CO2 predicted by the model (5–49) compared with measured ratios (two or less). In model 2, this ratio was reduced by assuming that confining beds adjacent to the aquifer act as sources of dissolved organic carbon and sulfate. This assumption was based on measured high concentrations of dissolved organic acids and sulfate in confining-bed pore waters (60–100 μM and 100–380 μM, respectively) relative to aquifer pore waters (from less than 30 μM and 2–80 μM, respectively). Sodium was chosen as the companion ion to organic-acid and sulfate transport from confining beds because it is the predominant cation in confining-bed pore waters. As a result, excessive amounts of Na-for-Ca ion exchange and calcite precipitation (three to four times more cement than observed in the aquifer) were required by model 2 to achieve mass and isotope balance of final water. For this reason, model 2 was invalidated. Agreement between model-predicted and measured amounts of carbonate cement and ratios of fermentation CO2 to respiration CO2 were obtained in a reaction model that assumed confining beds act as sources of DIC, as well as organic acids and sulfate. This assumption was

  9. Recent Advances in Inorganic Heterogeneous Electrocatalysts for Reduction of Carbon Dioxide.

    Science.gov (United States)

    Zhu, Dong Dong; Liu, Jin Long; Qiao, Shi Zhang

    2016-05-01

    In view of the climate changes caused by the continuously rising levels of atmospheric CO2 , advanced technologies associated with CO2 conversion are highly desirable. In recent decades, electrochemical reduction of CO2 has been extensively studied since it can reduce CO2 to value-added chemicals and fuels. Considering the sluggish reaction kinetics of the CO2 molecule, efficient and robust electrocatalysts are required to promote this conversion reaction. Here, recent progress and opportunities in inorganic heterogeneous electrocatalysts for CO2 reduction are discussed, from the viewpoint of both experimental and computational aspects. Based on elemental composition, the inorganic catalysts presented here are classified into four groups: metals, transition-metal oxides, transition-metal chalcogenides, and carbon-based materials. However, despite encouraging accomplishments made in this area, substantial advances in CO2 electrolysis are still needed to meet the criteria for practical applications. Therefore, in the last part, several promising strategies, including surface engineering, chemical modification, nanostructured catalysts, and composite materials, are proposed to facilitate the future development of CO2 electroreduction. PMID:26996295

  10. Light harvesting with non covalent carbon nanotube / porphyrin compounds.

    OpenAIRE

    Roquelet, Cyrielle; Langlois, Benjamin; Vialla, Fabien; Garrot, Damien; Lauret, Jean-Sébastien; Voisin, Christophe

    2013-01-01

    We present recent developments in the synthesis and in the functional study of non covalently bound porphyrin/carbon nanotube compounds. The issue of the chemical stability of non covalent compounds is tackled by means of micelle assisted chemistry. The non covalent functionalization allows to preserve the electronic integrity of the nanotubes that display bright NIR luminescence. In the same time, the coupling between the subunits is very strong and leads to e cient energy transfer and PL qu...

  11. Integrating Carbon Nanotubes into Microfluidic Chip for Separating Biochemical Compounds

    OpenAIRE

    Chen, Miaoxiang Max; Mogensen, Klaus Bo; BØGGILD, Peter; Kutter, Jörg Peter

    2012-01-01

    We present a new type of device to separate biochemical compounds wherein carbon nanotubes (CNTs) are integrated as chromatographic stationary phase. The CNTs were directly grown on the bottom of microfluidic channels on Si/SiO2 substrates by chemical vapor deposition (CVD). Acetylene was used as carbon source and Ni was employed as catalyst. For electrokinetic separations, higher electrical field strength is usually required; therefore, the CNTs were constructed in pillar-array-form by patte...

  12. Carbon dioxide capture by means of cyclic organic nitrogen compounds

    OpenAIRE

    García Abuín, Alicia

    2012-01-01

    The research work included in present PhD Thesis involves the research studies to capture carbon dioxide using different cyclic nitrogen organic compounds (glucosamine (GA), chitosan (C), alkyl-pyrrolidones, pyrrolidine (PYR) and piperidine (PIP). This investigation is based on the study of three experimental systems. Each of them has characteristics potentially suitable to achieve the aim of this work, that is to say, to improve the carbon dioxide capture process, which is pre...

  13. Inorganic arsenic speciation by differential pulse anodic stripping voltammetry using thoria nanoparticles-carbon paste electrodes.

    Science.gov (United States)

    Pereira, F J; Vázquez, M D; Debán, L; Aller, A J

    2016-05-15

    Two novel thoria (ThO2) nanoparticles-carbon paste electrodes were used to evaluate an anodic stripping voltammetric method for the direct determination of arsenite and total inorganic arsenic (arsenite plus arsenate) in water samples. The effect of Ag((I)), Cu((II)), Hg((II)), Sb((III)) and Se((IV)) ions on the electrochemical response of arsenic was assayed. The developed electroanalytical method offers a rapid procedure with improved analytical characteristics including good repeatability (3.4%) at low As((III)) concentrations, high selectivity, lower detection limit (0.1μgL(-1)) and high sensitivity (0.54μAμg(-1)L). The analytical capability of the optimized method was demonstrated by the determination of arsenic in certified reference materials (trace elements in natural water, trace elements in water and coal fly ash). PMID:26992513

  14. Determination of the origin of dissolved inorganic carbon in groundwater around a reclaimed landfill in Otwock using stable carbon isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Porowska, Dorota, E-mail: dorotap@uw.edu.pl

    2015-05-15

    Highlights: • Research showed the origin of DIC in the groundwater around a reclaimed landfill. • Carbon isotope was used to evaluate the contributions of carbon from different sources. • The leachate-contaminated water was isotopically distinct from the natural groundwater. • DIC in the natural groundwater comes from organic matter and dissolution of carbonates. • In the contaminated water, DIC comes from organic matter in the aquifer and landfill. - Abstract: Chemical and isotopic analyses of groundwater from piezometers located around a reclaimed landfill in Otwock (Poland) were performed in order to trace the origin of dissolved inorganic carbon (DIC) in the groundwater. Due to differences in the isotopic composition of carbon from different sources, an analysis of stable carbon isotopes in the groundwater, together with the Keeling plot approach and a two-component mixing model allow us to evaluate the relative contributions of carbon from these sources in the groundwater. In the natural (background) groundwater, DIC concentrations and the isotopic composition of DIC (δ{sup 13}C{sub DIC}) comes from two sources: decomposition of organic matter and carbonate dissolution within the aquifer sediments, whereas in the leachate-contaminated groundwater, DIC concentrations and δ{sup 13}C{sub DIC} values depend on the degradation of organic matter within the aquifer sediments and biodegradation of organic matter stored in the landfill. From the mixing model, about 4–54% of the DIC pool is derived from organic matter degradation and 96–46% from carbonate dissolution in natural conditions. In the leachate-contaminated groundwater, about 20–53% of the DIC is derived from organic matter degradation of natural origin and 80–47% from biodegradation of organic matter stored in the landfill. Partial pressure of CO{sub 2} (P CO{sub 2}) was generally above the atmospheric, hence atmospheric CO{sub 2} as a source of carbon in DIC pool was negligible in the

  15. Determination of the origin of dissolved inorganic carbon in groundwater around a reclaimed landfill in Otwock using stable carbon isotopes

    International Nuclear Information System (INIS)

    Highlights: • Research showed the origin of DIC in the groundwater around a reclaimed landfill. • Carbon isotope was used to evaluate the contributions of carbon from different sources. • The leachate-contaminated water was isotopically distinct from the natural groundwater. • DIC in the natural groundwater comes from organic matter and dissolution of carbonates. • In the contaminated water, DIC comes from organic matter in the aquifer and landfill. - Abstract: Chemical and isotopic analyses of groundwater from piezometers located around a reclaimed landfill in Otwock (Poland) were performed in order to trace the origin of dissolved inorganic carbon (DIC) in the groundwater. Due to differences in the isotopic composition of carbon from different sources, an analysis of stable carbon isotopes in the groundwater, together with the Keeling plot approach and a two-component mixing model allow us to evaluate the relative contributions of carbon from these sources in the groundwater. In the natural (background) groundwater, DIC concentrations and the isotopic composition of DIC (δ13CDIC) comes from two sources: decomposition of organic matter and carbonate dissolution within the aquifer sediments, whereas in the leachate-contaminated groundwater, DIC concentrations and δ13CDIC values depend on the degradation of organic matter within the aquifer sediments and biodegradation of organic matter stored in the landfill. From the mixing model, about 4–54% of the DIC pool is derived from organic matter degradation and 96–46% from carbonate dissolution in natural conditions. In the leachate-contaminated groundwater, about 20–53% of the DIC is derived from organic matter degradation of natural origin and 80–47% from biodegradation of organic matter stored in the landfill. Partial pressure of CO2 (P CO2) was generally above the atmospheric, hence atmospheric CO2 as a source of carbon in DIC pool was negligible in the aquifer. P CO2 values in the aquifer in

  16. Radionuclides, inorganic constitutents, organic compounds, and bacteria in water from selected wells and springs from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman Area, Idaho, 1992

    International Nuclear Information System (INIS)

    The U.S. Geological Survey and the Idaho Department of Water Resources, in response to a request from the U.S. Department of Energy, sampled 18 sites as part of a long-term project to monitor water quality of the Snake River Plain aquifer from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman area. Water samples were collected and analyzed for selected radionuclides, inorganic constituents, organic compounds, and bacteria. The samples were collected from 13 irrigation wells, 1 domestic well, 1 spring, 2 stock wells, and 1 public supply well. Quality assurance samples also were collected and analyzed. None of the samples analyzed for radionuclides, inorganic constituents, or organic compounds exceeded the established maximum contaminant levels for drinking water. Most of the radionuclide and inorganic constituent concentrations exceeded their respective reporting levels. Most of the samples analyzed for surfactants and dissolved organic carbon had concentrations that exceeded their reporting levels. None of the samples contained reportable concentrations of purgeable organic compounds or pesticides. Total coliform bacteria was present in nine samples

  17. Photochemical production of dissolved inorganic carbon from suwannee river humic acid

    Institute of Scientific and Technical Information of China (English)

    WANG Xuejun; LOU Tao; XIE Huixiang

    2009-01-01

    The photochemical mineralization of dissolved organic carbon (DOC) to dissolved inorganic carbon (DIC) is a key process in carbon cycling. Using a Suntest CPS solar simulator, Suwannee River humic acid (SRHA) was photooxidated to examine the effects of O2 levels, the wavelength of incident light, and the concentration of Fe on the photoproduction of DIC. Increasing the O2 abundance enhanced photodegradation of SRHA. The rate of DIC photoproduction under air saturation in the first 24 h (4.40 μmol/(L h)) was increased by a factor of 1.56 under O2 saturation, but fell by only 36% under N2 saturation. To evaluate the relative importance of UV-B, UV-A, and visible radiation in the photodegradation, we examined the above process using Mylar-d films and UF-3 and UF-4 plexiglass filters. The results indicated that the UV-B, UV-A and visible wavelengths accounted for 31.8%, 32.6% and 25.6%, respectively, of DIC production with simulated sunlight irradiation. The above results also indicated that photoproduction of DIC could take place in natural water at depths greater than those that UV light can reach. When 20 μmol/L desferrioxamine mesylate (DFOM, a strong Fe complexing ligand) was added, the rate of DIC photoproduction fell to 55.6% that of the original SRHA samples with 5.46 μmol/L Fe.

  18. Lithium isotopes in foraminifera shells as a novel proxy for the ocean dissolved inorganic carbon (DIC)

    Science.gov (United States)

    Vigier, Nathalie; Rollion-Bard, Claire; Levenson, Yaël; Erez, Jonathan

    2015-01-01

    Past ocean pH and pCO2 are critical parameters for establishing relationships between Earth's climate and the carbon cycle. Previous pCO2 estimates are associated with large uncertainties and are debated. In this study, laboratory cultures of the foraminiferan genus Amphistegina were performed in order to examine the possible factors that control the Li isotope composition (δ7Li) of their shells. δ7Li is insensitive to temperature and pH variations but correlates positively with the Dissolved Inorganic Carbon (DIC) of seawater. Li/Ca ratio in the shells shows negative correlation with δ7Li, consistent with published data for planktonic foraminifera from core tops and from short periods during the Cenozoic. We propose that the sensitivity of δ7Li and Li/Ca ratio to DIC is a biological phenomenon and is related to biomineralization mechanisms in foraminifera. We used the published foraminiferal δ7Li records, and our experimental results, to determine the paleo-ocean DIC and pH for the last glacial-interglacial cycle. The results are consistent with published estimates of pH and pCO2 based on boron isotopes and ice cores. We suggest Li and its isotopes may serve as a new complementary proxy for the paleo-ocean carbonate chemistry.

  19. Soil Organic and Inorganic Carbon Stocks in Yanqi Basin of Northwestern China: A Study of Land Use Impact

    Science.gov (United States)

    Wang, J.; Wang, X.; Zhang, J.

    2011-12-01

    Soil carbon storage is an important element in the global carbon budgets. Although soil organic carbon (SOC) is low on arid land, there is evidence of a large amount of soil inorganic carbon (SIC). Here, we present a study of soil carbon dynamics, which was carried out in the central Xinjiang, i.e., the Yanqi Basin. The objective of this study is to examine the effect of land use on both SOC and SIC. We sampled 20 profiles to 100 cm depth, which are covered with little vegetation (i.e., desert land), shrub, crop and grass. We used three methods to measure SOC and SIC contents. Soil organic C content are determined using the automated CNS analyzer, the traditional Walkleyand Black method and Loss-on-ignition at 375°C for 17 hours, and soil inorganic C content by the automated CNS analyzer, pressure calimeter method and Loss-on-ignition from 375°C to 800°C. There are high correlations in both SOC and SIC among all three methods (Figure 1). Our results show that both SOC and SIC follow an order: desert land 10 kg m-2, to >50 kg m-2, respectively, for the 0-100 cm profile. On average, SIC counts >75% of the total soil carbon stock across all the land use types (Figure 2). Our study suggests that agricultural development on desert and shrub land is likely to increase soil organic/inorganic carbon storage.

  20. Immobilization of Bacillus sp. in mesoporous activated carbon for degradation of sulphonated phenolic compound in wastewater

    International Nuclear Information System (INIS)

    Xenobiotic compounds are used in considerable quantities in leather industries besides natural organic and inorganic compounds. These compounds resist biological degradation and thus they remain in the treated wastewater in the unaltered molecular configurations. Immobilization of organisms in carrier matrices protects them from shock load application and from the toxicity of chemicals in bulk liquid phase. Mesoporous activated carbon (MAC) has been considered in the present study as the carrier matrix for the immobilization of Bacillus sp. isolated from Effluent Treatment Plant (ETP) employed for the treatment of wastewater containing sulphonated phenolic (SP) compounds. Temperature, pH, concentration, particle size and mass of MAC were observed to influence the immobilization behavior of Bacillus sp. The percentage immobilization of Bacillus sp. was the maximum at pH 7.0, temperature 20 °C and at particle size 300 μm. Enthalpy, free energy and entropy of immobilization were − 46.9 kJ mol−1, − 1.19 kJ mol−1 and − 161.36 J K−1 mol−1 respectively at pH 7.0, temperature 20 °C and particle size 300 μm. Higher values of ΔH0 indicate the firm bonding of the Bacillus sp. in MAC. Degradation of aqueous sulphonated phenolic compound by Bacillus sp. immobilized in MAC followed pseudo first order rate kinetics with rate constant 1.12 × 10−2 min−1. Highlights: ► Degradation on phenolic syntan using immobilized activated carbon as catalyst. ► Bacillus sp. immobilized cell reactor removed all refractory organic loads. ► The removal mechanism is due to co-metabolism between carbon and organisms. ► The organics are completely metabolized rather than adsorption.

  1. Immobilization of Bacillus sp. in mesoporous activated carbon for degradation of sulphonated phenolic compound in wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Sekaran, G., E-mail: ganesansekaran@gmail.com [Environmental Technology Division, Council of Scientific and Industrial Research (CSIR), Central Leather Research Institute (CLRI), Adyar, Chennai-600 020 (India); Karthikeyan, S. [Environmental Technology Division, Council of Scientific and Industrial Research (CSIR), Central Leather Research Institute (CLRI), Adyar, Chennai-600 020 (India); Gupta, V.K. [Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee-247 667 (India); Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Boopathy, R.; Maharaja, P. [Environmental Technology Division, Council of Scientific and Industrial Research (CSIR), Central Leather Research Institute (CLRI), Adyar, Chennai-600 020 (India)

    2013-03-01

    Xenobiotic compounds are used in considerable quantities in leather industries besides natural organic and inorganic compounds. These compounds resist biological degradation and thus they remain in the treated wastewater in the unaltered molecular configurations. Immobilization of organisms in carrier matrices protects them from shock load application and from the toxicity of chemicals in bulk liquid phase. Mesoporous activated carbon (MAC) has been considered in the present study as the carrier matrix for the immobilization of Bacillus sp. isolated from Effluent Treatment Plant (ETP) employed for the treatment of wastewater containing sulphonated phenolic (SP) compounds. Temperature, pH, concentration, particle size and mass of MAC were observed to influence the immobilization behavior of Bacillus sp. The percentage immobilization of Bacillus sp. was the maximum at pH 7.0, temperature 20 Degree-Sign C and at particle size 300 {mu}m. Enthalpy, free energy and entropy of immobilization were - 46.9 kJ mol{sup -1}, - 1.19 kJ mol{sup -1} and - 161.36 J K{sup -1} mol{sup -1} respectively at pH 7.0, temperature 20 Degree-Sign C and particle size 300 {mu}m. Higher values of {Delta}H{sup 0} indicate the firm bonding of the Bacillus sp. in MAC. Degradation of aqueous sulphonated phenolic compound by Bacillus sp. immobilized in MAC followed pseudo first order rate kinetics with rate constant 1.12 Multiplication-Sign 10{sup -2} min{sup -1}. Highlights: Black-Right-Pointing-Pointer Degradation on phenolic syntan using immobilized activated carbon as catalyst. Black-Right-Pointing-Pointer Bacillus sp. immobilized cell reactor removed all refractory organic loads. Black-Right-Pointing-Pointer The removal mechanism is due to co-metabolism between carbon and organisms. Black-Right-Pointing-Pointer The organics are completely metabolized rather than adsorption.

  2. Two decades of inorganic carbon dynamics along the Western Antarctic Peninsula

    Directory of Open Access Journals (Sweden)

    C. Hauri

    2015-05-01

    Full Text Available We present 20 years of seawater inorganic carbon measurements collected along the western shelf and slope of the Antarctic Peninsula. Water column observations from summertime cruises and seasonal surface underway pCO2 measurements provide unique insights into the spatial, seasonal and interannual variability of the dynamic system. The discrete measurements from depths > 2000 m align well with World Ocean Circulation Experiment observations across the time-series and underline the consistency of the data set. Analysis shows large spatial gradients in surface alkalinity and dissolved inorganic carbon content, with a concomitant wide range of Ωarag from values arag despite glacial and sea-ice melt water input. In support of previous studies, we observed Redfield behavior of regional C / N nutrient utilization, while the C / P (80.5 ± 2.5 and N / P (11.7 ± 0.3 molar ratios were significantly lower than the Redfield elemental stoichiometric values. Seasonal predictions of Ωarag suggest that surface waters remained mostly supersaturated with regard to aragonite throughout the study. However, more than a third of the predictions for winters between 1999 and 2013 resulted in Ωarag arag may have implications for important organisms such as pteropods. Despite large interannual variability, surface pCO2 measurements indicate a statistically significant increasing trend of up to 23 μatm per decade in fall and spring and a concomitant decreasing pH, pointing towards first signs of ocean acidification in the region. The combination of ongoing ocean acidification and freshwater input may soon provoke more unfavorable conditions than what the ecosystem experiences today.

  3. [Pollution characteristics and source of the atmospheric fine particles and secondary inorganic compounds at Mount Dinghu in autumn season].

    Science.gov (United States)

    Liu, Zi-Rui; Wang, Yue-Si; Liu, Quan; Liu, Lu-Ning; Zhang, De-Qiang

    2011-11-01

    Real-time measurements of PM2.5, secondary inorganic compounds in PM2.5 (SO4(2-), NH4(+), and NO3(-)) and related gaseous pollutants were conducted at Mount Dinghu, a regional background station of the Pearl River Delta (PRD), in October and November 2008 by using a conventional R&P TEOM and a system of rapid collection of fine particles and ion chromatography (RCFP-IC). Sources and transportation of atmospheric particles during the experiment were discussed with principal component analysis and backward trajectories calculated using HYSPLIT model. The average daily mass concentrations of PM2.5 were 76.9 microg x m(-3) during sampling period, and average daily mass concentrations of SO4(2-), NH4(+), and NO3(-) were 20.0 microg x m(-3), 6.8 microg x m(-3) and 2.6 microg x m(-3), respectively. The sum of these three secondary inorganic compounds accounted for more than one third of the PM2.5 mass concentration, which had become the major source of atmospheric fine particles at Mount Dinghu. The diurnal variation of PM2.5, SO4(2-), and NH4(+) all showed a "bimodal" distribution with two peaks appeared at 10:00 am and at 16:00 pm, respectively, whereas NO3(-s) howed "single peak" distribution peaked at 10:00 am. The mass concentrations of SO4(2-) in PM2.5 had the similar diurnal variation with that of SO2, SO4(2-) in PM2.5 was mainly transformed from SO2, whereas NO3(-) showed difference diurnal variation with that of NO2, and the second conversion rate of NO2 was far lower than that of SO2. NH4(+) in PM2.5 existed mainly in the form of sulfate, nitrate and chloride. Both of principal component analysis and back trajectory analysis showed that the variations of PM2.5 and secondary inorganic compounds at Mount Dinghu were mainly affected by the long-range transport air mass passed over Guangzhou, Huizhou and other highly industrialized areas which carried air pollutants to the observation site, at the same time local sulfate originated from secondary formation also

  4. Carbon limitation reveals allocation priority to defense compounds in peppermint

    Science.gov (United States)

    Forkelova, Lenka; Unsicker, Sybille; Forkel, Matthias; Huang, Jianbei; Trumbore, Susan; Hartmann, Henrik

    2016-04-01

    Studies of carbon partitioning during insect or pathogen infestation reveal high carbon investment into induced chemical defenses to deter the biotic agent (Baldwin, 1998). However, little is known how carbon investment into chemical defenses changes under abiotic stress such as drought. Drought forces plants to close their stomata to prevent water loss through transpiration while decreasing the amount of assimilated carbon. Furthermore drought hampers carbohydrates translocation due to declining plant hydration and reduced phloem functioning (McDowell, 2011; Hartmann et al., 2013; Sevanto, 2014). Hence long lasting drought can force plants into carbon starvation. The aim of our study was to disentangle carbon allocation priorities between growth, maintenance metabolism, storage and production of defense compounds under carbon limiting conditions using peppermint as our model plant. Drought is not the only method how to manipulate plant carbon metabolism and photosynthetic yield. Exposing plants to reduced [CO2] air is a promising tool simulating drought induced carbon limitation without affecting phloem functioning and so carbohydrate translocation (Hartmann et al., 2015). We exposed peppermint plants to drought (50% of the control irrigation) and to low [CO2] (progressive decrease from 350 ppm to 20 ppm) to disentangle hydraulic failure from carbon starvation effects on carbon allocation. Drought was applied as a cross-treatment yielding four treatments: watered and high [CO2] (W+CO2), drought and high [CO2] (D+CO2), water and low [CO2] (W-CO2), drought and low [CO2] (D-CO2). We analyzed the most abundant terpenoid defense compounds (α-Pinene, sabinene, myrcene, limonene, menthone, menthol and pulegone) and used continuous 13CO2 labelling to trace allocation pattern of new and old assimilated carbon in the four carbon sinks (structural biomass, water soluble sugars, starch and terpenoid defense compounds) in young expanding leaf tissue. This leaf tissue grew

  5. Variations in the inorganic carbon components in the thermal fronts during winter in the Northeastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; Delabehra, H.B.; Sudharani, P.; Remya, R.; Patil, J.S.; Desai, D.V.

    In order to examine the variations in inorganic carbon components in the thermal fronts, seven fronts have been sampled in the northeastern Arabian Sea during winter. The sea surface temperature (SST) was cooler by 0.2 to 1.03 °C within the fronts...

  6. Synthesis and Characterization of Poly(St-co-BA) Latex with an Organic-Inorganic Hybrid Compound as Emulsifier

    Institute of Scientific and Technical Information of China (English)

    袁俊杰; 周树学; 廖建和; 武利民

    2003-01-01

    A poly (St-co-BA) latex was successfully synthesized by using an organic-inorganic hybrid compound (OIHC), an aliphatic carboxylate sodium/nano-silica composite, as the emulsifier, and investigated by particle size analyzer, transmission electron microscope (TEM), optical contact angle measurement (OCA) and dynamic mechanical analyzer (DMA). It was found that the protective agent, sodium polyacrylate (PA),could obviously improve the polymerization stability and the functional monomer, glycidyl methacrylate (GMA), could enhance the store stability of the latex. The particle size of poly(St-co-BA) latex decreased and then leveled off as OIHC content increased. TEM shows that the prepared polymers were a~:tually organic-inorganic nanocomposites, and these films have better waterproof property than those prepared by traditional poly(St-co-BA) latex or organic silicone modified poly(St-co-BA) latex. The nanocomposite polymer has much higher glass transition temperature than organic silicone modified poly(St-co-BA) polymer containing the same organic silicone content.

  7. Tracing carbon fixation in phytoplankton—compound specific and total

    NARCIS (Netherlands)

    Grosse, J.; Van Breugel, P.; Boschker, H.T.S.

    2015-01-01

    Measurement of total primary production using 13C incorporation is a widely established tool. However, these bulk measurements lack information about the fate of fixed carbon: the production of major cellular compounds (carbohydrates, amino acids, fatty acids, and DNA/RNA) is affected by for instanc

  8. Integrating Carbon Nanotubes into Microfluidic Chip for Separating Biochemical Compounds

    DEFF Research Database (Denmark)

    Chen, Miaoxiang Max; Mogensen, Klaus Bo; Bøggild, Peter;

    2012-01-01

    We present a new type of device to separate biochemical compounds wherein carbon nanotubes (CNTs) are integrated as chromatographic stationary phase. The CNTs were directly grown on the bottom of microfluidic channels on Si/SiO2 substrates by chemical vapor deposition (CVD). Acetylene was used as...

  9. Magnetic behavior of inorganic-organic hybrid phosphite compounds with 3-d transition metals

    International Nuclear Information System (INIS)

    The (C2H10N2)[M(HPO3)F3](MIII=V, Cr, Fe) [I], (C2H10N2)[M3(HPO3)4] (MII=Mn, Co) [II] and (C2H10N2)0.5[Fe(HPO3)2](MIII=V, Fe) [III] compounds have been synthesized by using mild hydrothermal conditions. The crystal structure of the compounds shows different dimensionality. The compounds exhibit antiferromagnetic behavior, with hysteresis loops for the bimetallic (C2H10N2)[Mn2.09Co0.91(HPO3)4] and (C2H10N2)0.5[V0.48Fe0.52(HPO3)2] phases, indicating the existence of a ferrimagnetic behavior probably due to a spin descompensation

  10. Critical review of the chemistry and thermodynamics of technetium and some of its inorganic compounds and aqueous species

    International Nuclear Information System (INIS)

    Chemical and thermodynamic data for Technetium (Tc) and some of its inorganic compounds and aqueous species are reviewed here. Major emphasis is given to systems with potential geochemical applications, especially the geochemistry of radioactive waste disposal. Compounds considered include oxides, hydroxides, hydrates oxides, halides, oxyhalides, double halides, and sulfides. The aqueous species considered include those in both noncomplexing media (pertechnetates, technetates, aquo-ions, and hydrolyzed cations) and complexing media (halides, sulfates, and phosphates). Thermodynamic values are recommended for specific compounds and aqueous ions when reliable experimental data are available. Where thermodynamic data are inadequate or unavailable, the chemistry is still discussed to provide information about what needs to be measured, and which chemistry needs to be clarified. A major application of these thermodynamic data will be for chemical equilibrium modeling and for construction of potential-pH diagrams for aqueous solutions. Unfortunately, the present lack of data precludes such calculations for complexing aqueous media. The situation is much better for noncomplexing aqueous media, but the chemistry and thermodynamics of cationic Tc(V) species and hydrolyzed Tc(III) species are poorly understood. 240 references, 6 tables

  11. The Impact of Land Use Change on Primary Stream Organic and Inorganic Carbon Export

    Science.gov (United States)

    Kelsey, S. A.; Bauer, J. E.; Grottoli, A. G.; Huey Sanders, T. M.; Matsui, Y.

    2015-12-01

    Terrestrial land use may impact both the amounts of and characteristics of organic and inorganic carbon (OC and IC, respectively) entering aquatic ecosystems. Better understanding of how different land uses alter carbon characteristics and export fluxes from watersheds may lead to better management practices for retaining OC in terrestrial habitats and therefore mitigate CO2 emissions from freshwater ecosystems where terrestrial OC may be more rapidly respired. We examined the fluxes and δ13C and ∆14C signatures of dissolved IC (DIC), dissolved OC (DOC), and particulate OC (POC) exported from 6 watersheds with differing land use at the North Appalachian Experimental Watershed (NAEW) in Coshocton county in northeastern Ohio to assess whether differences in land use are related to variability in the export fluxes and isotopic characteristics of OC and IC pools. We used a Bayesian mixing model (MixSIR) to determine how the relative contributions of potential carbon sources to DIC, DOC, and POC change as a function of watershed land use. Mixing model results from each season were used to approximate relative annual contributions of potential sources to DIC, DOC, and POC export fluxes from each watershed. We found that agricultural land uses (i.e., corn, under both conventional till and no-till management) experienced the greatest degree of disturbance and had the greatest carbon export fluxes. However, the relative extent to which soil OC contributed to export fluxes compared to corn biomass varied as a function of tillage practices. In addition, nonparametric multidimensional scaling (NMDS), based on the δ13C and ∆14C data and mixing model results for DIC, DOC and POC export fluxes, separated non-corn watersheds into 2 further classes of disturbance: moderate disturbance (pasture and mixed land use) and low disturbance (forest). These findings suggest that land use has a measurable impact on the concentration and characteristics of watershed C export fluxes.

  12. A two-dimensional organic–inorganic hybrid compound, poly[(ethylenediamine) tri-l-oxido-oxidocopper(II)molybdenum(VI)

    OpenAIRE

    Mehtap Emirdag-Eanes; Don VanDerveer; Ozgul Gun

    2008-01-01

    A new organic–inorganic two-dimensional hybrid compound, [CuMoO4(C2H8N2)], has been hydrothermally synthesized at 443 K. The unit cell contains layers composed of CuN2O4 octahedra and MoO4 tetrahedra. Corner-sharing MoO4 and CuN2O4 polyhedra form CuMoO4 bimetallic sites that are joined together through O atoms, forming an edge-sharing Cu2Mo2O4 chain along the c axis. The one-dimensional chains are further linked through bridging O atoms that join the Cu and Mo atoms into respectiv...

  13. Reduction of inorganic compounds with molecular hydrogen by Micrococcus lactilyticus. I. Stoichiometry with compounds of arsenic, selenium, tellurium, transition and other elements.

    Science.gov (United States)

    WOOLFOLK, C A; WHITELEY, H R

    1962-10-01

    Woolfolk, C. A. (University of Washington, Seattle) and H. R. Whiteley. Reduction of inorganic compounds with molecular hydrogen by Micrococcus lactilyticus. I. Stoichiometry with compounds of arsenic, selenium, tellurium, transition and other elements. J. Bacteriol. 84:647-658. 1962.-Extracts of Micrococcus lactilyticus (Veillonella alcalescens) oxidize molecular hydrogen at the expense of certain compounds of arsenic, bismuth, selenium, tellurium, lead, thallium, vanadium, manganese, iron, copper, molybdenum, tungsten, osmium, ruthenium, gold, silver, and uranium, as well as molecular oxygen. Chemical and manometric data indicate that the following reductions are essentially quantitative: arsenate to arsenite, pentavalent and trivalent bismuth to the free element, selenite via elemental selenium to selenide, tellurate and tellurite to tellurium, lead dioxide and manganese dioxide to the divalent state, ferric to ferrous iron, osmium tetroxide to osmate ion, osmium dioxide and trivalent osmium to the metal, uranyl uranium to the tetravalent state, vanadate to the level of vanadyl, and polymolybdate ions to molybdenum blues with an average valence for molybdenum of +5. The results of a study of certain other hydrogenase-containing bacteria with respect to their ability to carry out some of the same reactions are also presented. PMID:14001842

  14. Dissolved inorganic carbon and alkalinity fluxes from coastal marine sediments: model estimates for different shelf environments and sensitivity to global change

    Directory of Open Access Journals (Sweden)

    V. Krumins

    2013-01-01

    Full Text Available We present a one-dimensional reactive transport model to estimate benthic fluxes of dissolved inorganic carbon (DIC and alkalinity (AT from coastal marine sediments. The model incorporates the transport processes of sediment accumulation, molecular diffusion, bioturbation and bioirrigation, while the reactions included are the redox pathways of organic carbon oxidation, re-oxidation of reduced nitrogen, iron and sulfur compounds, pore water acid-base equilibria, and dissolution of particulate inorganic carbon (calcite, aragonite, and Mg-calcite. The coastal zone is divided into four environmental units with different particulate inorganic carbon (PIC and particulate organic carbon (POC fluxes: reefs, banks and bays, carbonate shelves and non-carbonate shelves. Model results are analyzed separately for each environment and then scaled up to the whole coastal ocean. The model-derived estimate for the present-day global coastal benthic DIC efflux is 126 Tmol yr−1, based on a global coastal reactive POC depositional flux of 117 Tmol yr−1. The POC decomposition leads to a carbonate dissolution from shallow marine sediments of 7 Tmol yr−1 (on the order of 0.1 Pg C yr−1. Assuming complete re-oxidation of aqueous sulfide released from sediments, the effective net flux of alkalinity to the water column is 29 Teq. yr−1, primarily from PIC dissolution (46% and ammonification (33%. Because our POC depositional flux falls in the high range of global values given in the literature, the reported DIC and alkalinity fluxes should be viewed as upper-bound estimates. Increasing coastal seawater DIC to what might be expected in year 2100 due to the uptake of anthropogenic CO2 increases PIC dissolution by 2.3 Tmol yr−1and alkalinity efflux by 4.8 Teq. yr−1. Our reactive transport modeling approach not only yields global estimates of benthic DIC

  15. Dissolved inorganic carbon and alkalinity fluxes from coastal marine sediments: model estimates for different shelf environments and sensitivity to global change

    Directory of Open Access Journals (Sweden)

    V. Krumins

    2012-07-01

    Full Text Available We present a one-dimensional reactive transport model to estimate benthic fluxes of dissolved inorganic carbon (DIC and alkalinity (AT from coastal marine sediments. The model incorporates the transport processes of sediment accumulation, molecular diffusion, bioturbation and bioirrigation, while the reactions included are the redox pathways of organic carbon oxidation, re-oxidation of reduced nitrogen, iron and sulfur compounds, pore water acid-base equilibria, and dissolution of particulate inorganic carbon (calcite, aragonite, and Mg-calcite. The coastal zone is divided into four environmental units with different particulate inorganic carbon (PIC and particulate organic carbon (POC fluxes: reefs, banks and bays, carbonate shelves and non-carbonate shelves. Model results are analyzed separately for each environment and then scaled up to the whole coastal ocean. The model-derived estimate for the present-day global coastal benthic DIC efflux is 126 Tmol yr−1, based on a global coastal reactive POC depositional flux of 117 Tmol yr−1. The POC decomposition leads to a~carbonate dissolution from shallow marine sediments of 7 Tmol yr−1 (on the order of 0.1 Pg C yr−1. Assuming complete re-oxidation of aqueous sulfide released from sediments, the effective net flux of alkalinity to the water column is 29 Teq yr−1, primarily from PIC dissolution (46% and ammonification (33%. Because our POC depositional flux falls in the high range of global values given in the literature, the reported DIC and alkalinity fluxes should be viewed as upper-bound estimates. Increasing coastal seawater DIC to what might be expected in year 2100 due to the uptake of anthropogenic CO2 increases PIC dissolution by 2.3 Tmol yr−1 and alkalinity efflux by 4.8 Teq yr−1. Our reactive transport modeling approach not only yields global estimates of benthic DIC, alkalinity

  16. Determination of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) in freshwaters by sequential injection spectrophotometry with on-line UV photo-oxidation

    International Nuclear Information System (INIS)

    An automated sequential injection (SI) method for the determination of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) in freshwaters is presented. For DIC measurement on-line sample acidification (sulphuric acid, pH 2 which subsequently diffused through a PTFE membrane into a basic, cresol red acceptor stream. The CO2 increased the concentration of the acidic form of the cresol red indicator, with a resultant decrease in absorbance at 570 nm being directly proportional to DIC concentration. DIC + DOC was determined after on-line sample irradiation (15 W low power UV lamp) coupled with acid-peroxydisulfate digestion, with the subsequent detection of CO2 as described above. DOC was determined by subtraction of DIC from (DIC + DOC). Analytical figures of merit were linear ranges of 0.05-5.0 mg C L-1 for both DIC and DIC + DOC, with typical R.S.D.s of less than 7% (0.05 mg C L-1-5.3% for DIC and 6.6% for DIC + DOC; 4.0 mg C L-1-2.6% for DIC and 2.4% for DIC + DOC, n = 3) and an LOD (blank + 3S.D.) of 0.05 mg C L-1. Sample throughput for the automated system was 8 h-1 for DIC and DOC with low reagent consumption (acid/peroxydisulfate 200 μL per DIC + DOC analysis). A range of model carbon compounds and Tamar River (Plymouth, UK) samples were analysed for DIC and DOC and the results showed good agreement with a high temperature catalytic oxidation (HTCO) reference method (t-test, P = 0.05)

  17. Effects of inorganic carbon limitation on anaerobic ammonium oxidation (anammox) activity.

    Science.gov (United States)

    Kimura, Yuya; Isaka, Kazuichi; Kazama, Futaba

    2011-03-01

    Anammox bacteria are chemoautotrophic bacteria that oxidize ammonium with nitrite as the electron acceptor and with CO(2) as the main carbon source. The effects of inorganic carbon (IC) limitation on anammox bacteria were investigated using continuous feeding tests. In this study, a gel carrier with entrapped anammox sludge was used. It was clearly shown that the anammox activity deteriorated with a decrease in the influent IC concentration. The relationship between the influent IC concentration and the anammox activity was analyzed using Michaelis-Menten kinetics, and the apparent K(m) was determined to be 1.2mg-C/L. The activity could be recovered by adding IC to the influent. The consumption ratio of IC to ammonium was not constant and mainly depended on the influent ratio of the IC to ammonium concentrations (inf.IC/inf.NH(4)-N). The results indicated that an inf.IC/inf.NH(4)-N ratio of 0.2 in the anammox reactor was ideal for the anammox process using gel cubes. PMID:21256745

  18. Anode material selection criteria for selective oxidation of inorganic compounds in nitric acid media

    International Nuclear Information System (INIS)

    PtOx and carbon compounds. The experimental findings led to a better understanding of the role of the nitrates involved in multiple processes. From the standpoint of electro-activity, nitrates appear to contribute to the water oxidation mechanism and favor the evolution of oxygen at potentials above 2.05 VESH, while the electron transfer of the Ag2+/Ag+ couple is relatively unaffected by this counter-ion. The decreasing diffusivity of Ag+ ions as the nitric acid concentration increases affects the overall Ag2+ ion generation in over-concentrated nitric acid medium. The complexation qualities of the nitrate ions that make them suitable ligands for Ag2+ ions also induce specific effects: the potential is shifted by about 200 mV, and the water oxidation reaction is catalyzed. A qualitative analysis of this phenomenon involving the electrode/solution interface competition between the AgNO3+ complex and the Ago precipitate and a quantitative analysis of the diminishing electrolytic generation efficiency are discussed. Test results with various materials show that the classification based on a high oxygen over-potential is a necessary but insufficient criterion. Material selectivity is also related to chemical processes at the interface as noted above. For example, the redox chemistry of the anode material in nitric acid media accelerates the parasitic processes in the case of lead dioxide. Polarization of the electrode material at high anode potentials, as in the case of platinum, implies the formation of oxide layers that are relatively unstable in nitric acid media, and which must also be considered as a factor to be analyzed with respect to material selectivity. The proposed approach provides a rational interpretation of the search for new anode materials based on electron transfer kinetics and on the transport of various species, but primarily on the analysis of the chemical and electrochemical interference specific to nitric acid media. This approach can easily be

  19. Experimental investigation of single carbon compounds under hydrothermal conditions

    Science.gov (United States)

    Seewald, Jeffrey S.; Zolotov, Mikhail Yu.; McCollom, Thomas

    2006-01-01

    The speciation of carbon in subseafloor hydrothermal systems has direct implications for the maintenance of life in present-day vent ecosystems and possibly the origin of life on early Earth. Carbon monoxide is of particular interest because it represents a key reactant during the abiotic synthesis of reduced carbon compounds via Fischer-Tropsch-type processes. Laboratory experiments were conducted to constrain reactions that regulate the speciation of aqueous single carbon species under hydrothermal conditions and determine kinetic parameters for the oxidation of CO according to the water water-gas shift reaction (CO 2 + H 2 = CO + H 2O). Aqueous fluids containing added CO 2, CO, HCOOH, NaHCO 3, NaHCOO, and H 2 were heated at 150, 200, and 300 °C and 350 bar in flexible-cell hydrothermal apparatus, and the abundances of carbon compounds was monitored as a function of time. Variations in fluid chemistry suggest that the reduction of CO 2 to CH 3OH under aqueous conditions occurs via a stepwise process that involves the formation of HCOOH, CO, and possibly CH 2O, as reaction intermediaries. Kinetic barriers that inhibit the reduction of CH 3OH to CH 4 allow the accumulation of reaction intermediaries in solution at high concentrations regulated by metastable thermodynamic equilibrium. Reaction of CO 2 to CO involves a two-step process in which CO 2 initially undergoes a reduction step to HCOOH which subsequently dehydrates to form CO. Both reactions proceed readily in either direction. A preexponential factor of 1.35 × 10 6 s -1 and an activation energy of 102 kJ/mol were retrieved from the experimental results for the oxidation of CO to CO 2. Reaction rates amongst single carbon compounds during the experiments suggest that ΣCO 2 (CO 2 + HCO 3- + CO 32-), CO, ΣHCOOH (HCOOH + HCOO -), and CH 3OH may reach states of redox-dependent metastable thermodynamic equilibrium in subseafloor and other hydrothermal systems. The abundance of CO under equilibrium conditions

  20. Stable carbon isotopes of dissolved inorganic carbon for a zonal transect across the subpolar North Atlantic Ocean in summer 2014

    Science.gov (United States)

    Humphreys, Matthew P.; Greatrix, Florence M.; Tynan, Eithne; Achterberg, Eric P.; Griffiths, Alex M.; Fry, Claudia H.; Garley, Rebecca; McDonald, Alison; Boyce, Adrian J.

    2016-06-01

    The stable carbon isotope composition of dissolved inorganic carbon (δ13CDIC) in seawater was measured in samples collected during June-July 2014 in the subpolar North Atlantic. Sample collection was carried out on the RRS James Clark Ross cruise JR302, part of the "Radiatively Active Gases from the North Atlantic Region and Climate Change" (RAGNARoCC) research programme. The observed δ13CDIC values for cruise JR302 fall in a range from -0.07 to +1.95 ‰, relative to the Vienna Pee Dee Belemnite standard. From duplicate samples collected during the cruise, the 1σ precision for the 341 results is 0.08 ‰, which is similar to our previous work and other studies of this kind. We also performed a cross-over analysis using nearby historical δ13CDIC data, which indicated that there were no significant systematic offsets between our measurements and previously published results. We also included seawater reference material (RM) produced by A. G. Dickson (Scripps Institution of Oceanography, USA) in every batch of analysis, enabling us to improve upon the calibration and quality-control procedures from a previous study. The δ13CDIC is consistent within each RM batch, although its value is not certified. We report δ13CDIC values of 1.15 ± 0.03 ‰ and 1.27 ± 0.05 ‰ for batches 141 and 144 respectively. Our JR302 δ13CDIC data can be used - along with measurements of other biogeochemical variables - to constrain the processes that control DIC in the interior ocean, in particular the oceanic uptake of anthropogenic carbon dioxide and the biological carbon pump. Our δ13CDIC results are available from the British Oceanographic Data Centre - doi:10.5285/22235f1a-b7f3-687f-e053-6c86abc0c8a6.

  1. [Effects of Organic and Inorganic Slow-Release Compound Fertilizer on Different Soils Microbial Community Structure].

    Science.gov (United States)

    Wang, Fei; Yuan, Ting; Gu, Shou-kuan; Wang, Zheng-yin

    2015-04-01

    As a new style fertilizer, slow-control release fertilizer had been an important subject in recent years, but few researches were about soil microbial community structure diversity. Phospholipid fatty acid method was used to determined the microbial community structure diversity of acid soil and slight alkaline soil applied with slow-release compound fertilizer (SRF), chemical fertilizer (CF) and common compound fertilizer (CCF) at the 10th, 30th, 60th and 90th day under the constant temperature incubation condition. Results indicated that various bacteria (i. e 13:0, i14:0,14:0, i15:0, a15:0, i16:0, 16:12OH, 16:1w5c,16:0, i17:0, a17:0, cy17:0, 17:02OH, i18:0, 18:0 and cy19:0w8c), two actinomycetes (10Me17:0 and 10Me18:0) and only one fungus (18:1 w9c) were detected in two soils after applying slow-release compound fertilizer and other fertilizers during the whole incubation period. SRF could significantly increase the fungi PLFA content by 8.3% and 6.8% at the early stage (the 10th day and 30th day) compared with CF, as well as significantly increase by 22.7% and 17.1% at the late stage (the 60th day and 90th day) compared with CCF in acid soil. SRF significantly increased bacteria, fungi and gram positive bacteria compared with CF and CCF in incubation period (except at the 30th day) in slight alkaline soil. SRF could significantly improve the ratio of normal saturated fatty acid and monounsaturated fatty acid at the 30th day and 90th days in acid soil compared with no fertilizer (CK), CF and CCF, while as to slight alkaline soil, SRF was significantly greater than that of CK, CF and CCF only at the 60th day. SRF could significantly decrease the ratio of iso PLFA and anteiso PLFA in acid soil (in 30-90 days) and slight alkaline soil (in 10-60 days). For two soils PLFA varieties, contents and ratios of microbial community, slow-release compound fertilizer increased soil microbial PLFA varieties and contents, and decreased the influence to microbial survival

  2. Electrochemical activation of carbon cloth in aqueous inorganic salt solution for superior capacitive performance

    Science.gov (United States)

    Ye, Dong; Yu, Yao; Tang, Jie; Liu, Lin; Wu, Yue

    2016-05-01

    Carbon cloth (CC) is an inexpensive and highly conductive textile with excellent mechanical flexibility and strength; it holds great promise as an electrode material for flexible supercapacitors. However, pristine CC has such a low surface area and poor electrochemical activity that the energy storage capability is usually very poor. Herein, we report a green method, two-step electrochemical activation in an aqueous solution of inorganic salts, to significantly enhance the capacitance of CC for supercapacitor application. Micro-cracks, exfoliated carbon fiber shells, and oxygen-containing functional groups (OFGs) were introduced onto the surface of the carbon filament. This resulted in an enhancement of over two orders of magnitude in capacitance compared to that of the bare CC electrode, reaching up to a maximum areal capacitance of 505.5 mF cm-2 at the current density of 6 mA cm-2 in aqueous H2SO4 electrolyte. Electrochemical reduction of CC electrodes led to the removal of most electrochemically unstable surface OFGs, resulting in superior charging/discharging rate capability and excellent cycling stability. Although the activated CC electrode contained a high-level of surface oxygen functional groups (~15 at%), it still exhibited a remarkable charging-discharging rate capability, retaining ~88% of the capacitance when the charging rate increased from 6 to 48 mA cm-2. Moreover, the activated CC electrode exhibited excellent cycling stability with ~97% capacitance remaining after 10 000 cycles at a current density of 24 mA cm-2. A symmetrical supercapacitor based on the activated CC exhibited an ideal capacitive behavior and fast charge-discharge properties. Such a simple, environment-friendly, and cost-effective strategy to activate CC shows great potential in the fabrication of high-performance flexible supercapacitors.Carbon cloth (CC) is an inexpensive and highly conductive textile with excellent mechanical flexibility and strength; it holds great promise as

  3. Comparative study on the pharmacokinetics of inorganic and organic iron compounds in broiler chickens

    OpenAIRE

    Dimitrichka Dimitrova; Anna Arnaudova-Matey; Petar Dilov; Geno Angelov; Tandju Mehmedov; Toni Todorov; Denka Kushvalieva; Dimitrina Nikolova; Valija Dilova

    2014-01-01

    The pharmacokinetics of ferrous methionate and ferrous sulphate was investigated in broiler chickens after intravenous injection and crop intubation. The iron compounds were injected intravenously in v. brachialis. After 20-day “wash-out” period the ferrous methionate and ferrous sulphate were administered again by an elastic silicone tube into the crop. The serum concentrations of the iron were determined with bioanalyser. Two pharmacokinetic approaches were used – compartmental and non-comp...

  4. The effects of combined application of inorganic Martian dust simulant and carbon dots on glutamate transport rat brain nerve terminals

    Science.gov (United States)

    Borisova, Tatiana; Krisanova, Natalia; Nazarova, Anastasiya; Borysov, Arseniy; Pastukhov, Artem; Pozdnyakova, Natalia; Dudarenko, Marina

    2016-07-01

    During inhalation, nano-/microsized particles are efficiently deposited in nasal, tracheobronchial, and alveolar regions and can be transported to the central nervous system (Oberdorster et al., 2004). Recently, the research team of this study found the minor fractions of nanoparticles with the size ~ 50 -60 nm in Lunar and Martian dust stimulants (JSC-1a and JSC, ORBITEC Orbital Technologies Corporation, Madison, Wisconsin), whereas the average size of the simulants was 1 mm and 4mm, respectively (Krisanova et al., 2013). Also, the research team of this study discovered new phenomenon - the neuromodulating and neurotoxic effect of carbon nano-sized particles - Carbon dots (C-dots), originated from ash of burned carbon-containing product (Borisova et al, 2015). The aims of this study was to analyse acute effects of upgraded stimulant of inorganic Martian dust derived from volcanic ash (JSC-1a/JSC, ORBITEC Orbital Technologies Corporation, Madison, Wisconsin) by the addition of carbon components, that is, carbon dots, on the key characteristic of synaptic neurotransmission. Acute administration of carbon-containing Martian dust analogue resulted in a significant decrease in transporter-mediated uptake of L-[14C]glutamate (the major excitatory neurotransmitter) by isolated rat brain nerve terminals. The ambient level of the neurotransmitter in the preparation of nerve terminals increased in the presence of carbon dot-contained Martian dust analogue. These effects were associated with action of carbon component of the upgraded Martian dust stimulant but not with its inorganic constituent.

  5. Electrochemical activation of carbon cloth in aqueous inorganic salt solution for superior capacitive performance.

    Science.gov (United States)

    Ye, Dong; Yu, Yao; Tang, Jie; Liu, Lin; Wu, Yue

    2016-05-21

    Carbon cloth (CC) is an inexpensive and highly conductive textile with excellent mechanical flexibility and strength; it holds great promise as an electrode material for flexible supercapacitors. However, pristine CC has such a low surface area and poor electrochemical activity that the energy storage capability is usually very poor. Herein, we report a green method, two-step electrochemical activation in an aqueous solution of inorganic salts, to significantly enhance the capacitance of CC for supercapacitor application. Micro-cracks, exfoliated carbon fiber shells, and oxygen-containing functional groups (OFGs) were introduced onto the surface of the carbon filament. This resulted in an enhancement of over two orders of magnitude in capacitance compared to that of the bare CC electrode, reaching up to a maximum areal capacitance of 505.5 mF cm(-2) at the current density of 6 mA cm(-2) in aqueous H2SO4 electrolyte. Electrochemical reduction of CC electrodes led to the removal of most electrochemically unstable surface OFGs, resulting in superior charging/discharging rate capability and excellent cycling stability. Although the activated CC electrode contained a high-level of surface oxygen functional groups (∼15 at%), it still exhibited a remarkable charging-discharging rate capability, retaining ∼88% of the capacitance when the charging rate increased from 6 to 48 mA cm(-2). Moreover, the activated CC electrode exhibited excellent cycling stability with ∼97% capacitance remaining after 10 000 cycles at a current density of 24 mA cm(-2). A symmetrical supercapacitor based on the activated CC exhibited an ideal capacitive behavior and fast charge-discharge properties. Such a simple, environment-friendly, and cost-effective strategy to activate CC shows great potential in the fabrication of high-performance flexible supercapacitors. PMID:27141910

  6. Radionuclides, inorganic constituents, organic compounds, and bacteria in water from selected wells and springs from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman Area, Idaho, 1990

    International Nuclear Information System (INIS)

    The US Geological Survey and the Idaho Department of Water Resources, in response to a request from the US Department of Energy, sampled 19 sites as part of a long-term project to monitor water quality of the Snake River Plain aquifer from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman area. Water samples were collected and analyzed for manmade pollutants and naturally occurring constituents. The samples were collected from seven irrigation wells, five domestic wells, two springs, one stock well, two dairy wells, one observation well, and one commercial well. Two quality assurance samples also were collected and analyzed. The water samples were analyzed for selected radionuclides, inorganic constituents, organic compounds, and bacteria. None of the radionuclides, inorganic constituents, or organic compounds exceeded the established maximum contaminant levels for drinking water. Most of the radionuclide and inorganic constituent concentrations exceeded their respective reporting levels. All samples analyzed for surfactants and dissolved organic carbon had concentrations that exceeded their reporting level. Toluene concentrations exceeded the reporting level in one water sample. Two samples contained fecal coliform bacteria counts that exceeded established maximum contaminant levels for drinking water

  7. Radionuclides, stable isotopes, inorganic constituents, and organic compounds in water from selected wells and springs from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman Area, Idaho, 1993

    International Nuclear Information System (INIS)

    The US Geological Survey and the Idaho Department of Water Resources, in response to a request from the US Department of Energy, sampled 19 sites as part of a long-term project to monitor water quality of the Snake River Plain aquifer from the southern boundary of the Idaho National Engineering Laboratory to the Hagerman area. Water samples were collected and analyzed for selected radionuclides, stable isotopes, inorganic constituents, and organic compounds. The samples were collected from seven irrigation wells, four domestic wells, two springs, one stock well, three dairy wells, one observation well, and one commercial well. Two quality assurance samples also were collected and analyzed. None of the radionuclide, inorganic constituent, or organic compound concentrations exceeded the established maximum contaminant levels for drinking water. Most of the radionuclide and inorganic constituent concentrations exceeded their respective reporting levels. All samples analyzed for surfactants and dissolved organic carbon had concentrations that equaled or exceeded their reporting levels. The ethylbenzene concentration in one water sample exceeded the reporting level

  8. Inorganic and organic carbon biogeochemistry in the Gautami Godavari estuary (Andhra Pradesh, India) during pre-monsoon: The local impact of extensive mangrove forests

    OpenAIRE

    Bouillon, Steven; Frankignoulle, M.; F. Dehairs; Velimirov, B.; Eiler, A.; Abril, G.; H. Etcheber; Borges, AV

    2003-01-01

    The distribution and sources of organic and inorganic carbon were studied in the Gautami Godavari estuary (Andhra Pradesh, India) and in a mangrove ecosystem in its delta during pre-monsoon. In the oligohaline and mesohaline section (salinity 0-15) of the estuary, internal production of total alkalinity (TAlk) and dissolved inorganic carbon (DIC) was recorded, and the δ13CDIC profile suggests that carbonate dissolution may be an important process determining the DIC dynamics in this section o...

  9. Prediction model of band gap for inorganic compounds by combination of density functional theory calculations and machine learning techniques

    Science.gov (United States)

    Lee, Joohwi; Seko, Atsuto; Shitara, Kazuki; Nakayama, Keita; Tanaka, Isao

    2016-03-01

    Machine learning techniques are applied to make prediction models of the G0W0 band gaps for 270 inorganic compounds using Kohn-Sham (KS) band gaps, cohesive energy, crystalline volume per atom, and other fundamental information of constituent elements as predictors. Ordinary least squares regression (OLSR), least absolute shrinkage and selection operator, and nonlinear support vector regression (SVR) methods are applied with two levels of predictor sets. When the KS band gap by generalized gradient approximation of Perdew-Burke-Ernzerhof (PBE) or modified Becke-Johnson (mBJ) is used as a single predictor, the OLSR model predicts the G0W0 band gap of randomly selected test data with the root-mean-square error (RMSE) of 0.59 eV. When KS band gap by PBE and mBJ methods are used together with a set of predictors representing constituent elements and compounds, the RMSE decreases significantly. The best model by SVR yields the RMSE of 0.24 eV. Band gaps estimated in this way should be useful as predictors for virtual screening of a large set of materials.

  10. Stimulating accumulation of nitrifying bacteria in porous carrier by addition of inorganic carbon in a continuous-flow fluidized bed wastewater treatment reactor.

    Science.gov (United States)

    Jun, B H; Tanji, Y; Unno, H

    2000-01-01

    Porous polyurethane carrier particles have been successfully applied for microbial immobilization to simultaneously remove carbonaceous and nitrogenous substances from wastewater by a fill-and-draw operation. This reactor system was extended to a continuous-flow operation mode, by which inorganic carbon (IC) was supplemented in order to stimulate the growth of autotrophic nitrifying bacteria. By addition of sodium bicarbonate, the ammonia oxidation reaction proceeded remarkably in the porous particle fluidized bed reactor, while a small increase in the nitrification was observed in a reactor with suspended microbes. Dissolved oxygen profile was obtained using an oxygen microelectrode to measure the microbial consumption of oxygen in the porous carrier. The size of ammonia-oxidizing bacterial populations in the carrier was proportional to the volume of the aerobic region of the carrier. The aerobic region decreased with the increase in sodium bicarbonate concentration, which improved the ammonia-oxidizing activity of retained nitrifiers in the carrier. The maximum ammonia oxidation rate was up to 55.6 gN/m3/h within the aerobic region of the carrier under the following feed conditions: 100 mg/l of total organic compound, 55 mg/l of ammonium concentration and 48 mg/l of inorganic carbon. PMID:16232755

  11. Molecular switches in carbon-rich organometallic compounds: Theoretical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Costuas, Karine, E-mail: kcostuas@univ-rennes1.fr [Sciences chimiques de Rennes, UMR 6226 CNRS - Université de Rennes 1, Avenue du Général Leclerc F-35042 Rennes (France)

    2015-01-22

    Organometallic complexes associated with an appropriate choice of ancillary ligands reveal to have a wide range of physical properties leading to promising applications when incorporated in nano-size devices. The challenge is to design innovative multifunctional compounds based on redox active carbon-rich organometallics associated with spin carriers and/or photochromic units. A multidisciplinary approach in this area has proved to be efficient in a series a systems combining carbon-rich bridging ligands and redox metallic moieties. In this domain, the role of theoretical investigations based on quantum mechanics tools have a crucial role in rationalizing and in helping designing systems possessing target properties.

  12. Molecular switches in carbon-rich organometallic compounds: Theoretical aspects

    International Nuclear Information System (INIS)

    Organometallic complexes associated with an appropriate choice of ancillary ligands reveal to have a wide range of physical properties leading to promising applications when incorporated in nano-size devices. The challenge is to design innovative multifunctional compounds based on redox active carbon-rich organometallics associated with spin carriers and/or photochromic units. A multidisciplinary approach in this area has proved to be efficient in a series a systems combining carbon-rich bridging ligands and redox metallic moieties. In this domain, the role of theoretical investigations based on quantum mechanics tools have a crucial role in rationalizing and in helping designing systems possessing target properties

  13. Comparative study on the pharmacokinetics of inorganic and organic iron compounds in broiler chickens

    Directory of Open Access Journals (Sweden)

    Dimitrichka Dimitrova

    2014-03-01

    Full Text Available The pharmacokinetics of ferrous methionate and ferrous sulphate was investigated in broiler chickens after intravenous injection and crop intubation. The iron compounds were injected intravenously in v. brachialis. After 20-day “wash-out” period the ferrous methionate and ferrous sulphate were administered again by an elastic silicone tube into the crop. The serum concentrations of the iron were determined with bioanalyser. Two pharmacokinetic approaches were used – compartmental and non-compartmental analysis. After i.v. injection we found statistically significantly longer and better distribution of the iron contained in the ferrous methionate compared to the ferrous sulphate. The АUC0→∞ was statistically significantly higher in the ferrous methionate. In the alimentary tract of broiler chickens, ferrous methionate was absorbed more rapidly than ferrous sulfate. It was also distributed at a higher volume as compared to the ferrous sulfate.

  14. Evaluation of organic and inorganic compounds levels of red wines processed from Pinot Noir grapes

    Directory of Open Access Journals (Sweden)

    Heli Sirén

    2015-03-01

    The wine products showed different profiles of carbohydrates, organic acids, phenolic compounds, and minerals. Especially, saccharose (max. 0.21 g/L, rhamnose (max. 0.45 g/L, fructose (max. 1.9 g/L, and phosphate (max 1.4 g/L quantities were extremely high in some wines. The results also showed that yeast fermentation in winemaking agitated high production of lactic (max 5.7 g/L and tartaric (max 1.7 g/L acids. The red wines processed by cold maceration and natural fermentation gave similar profiles. Only one of the Pinot Noir wines entirely differentiated from the others with comparison of carbohydrates and organic acids.

  15. Dissolved Organic and Inorganic Carbon Flow Paths in an Amazonian Transitional Forest

    Directory of Open Access Journals (Sweden)

    Vania eNeu

    2016-06-01

    Full Text Available As a raindrop falls from the atmosphere, over vegetation and forest canopies, and enters soils and streams it experiences a dynamic exchange of carbon constituents with the surrounding environment. Understanding the magnitude and dynamics of carbon export in above and below ground flow paths is critical for constraining the influence of terrestrial and aquatic ecosystems on global carbon cycling. Here we examine the concentration and flux of dissolved organic and inorganic carbon (DOC and DIC in rainfall, throughfall, stemflow, overland flow, soil solution, groundwater, and stream water in an Amazonian transitional forest located near the arc of deforestation. Rainfall was enriched in DOC by interactions with atmospheric particles derived from both biogenic and anthropogenic emissions, resulting in a flux of 82.3 kg C ha-1 yr-1, which was the largest flux from each respective flow path. Forest throughfall, stemflow, and direct overland flow mobilized DOC from products of terrestrial primary production and decomposition. Net throughfall represented the second largest DOC flux (68.4 kg C ha-1 yr-1, whereas stemflow and overland flow only had a flux of 1.5 and 3.9 kg C ha-1 yr-1, respectively. Much of the DOC in above ground flow paths was removed from solution as the rain percolated through soil layers due to both biological decomposition and sorption/desorption to mineral surfaces, resulting in low concentrations in stream and groundwater (2.6 ± 2.4 mg L-1 and 1.45 ± 0.3 mg L-1, respectively relative to throughfall (43.9 ± 5.2 mg L-1 and stemflow (30.6 ± 2.7 mg L-1. The flux of DIC in each respective flow path was generally lower than for DOC, and likely driven by atmospheric gas exchange and inputs from respiration and decomposition. DOC concentrations in above ground flow paths were highest during the first rainfall after a dry period, whereas DIC concentrations generally increased throughout the rainy season as soil moisture increased.

  16. Inorganic Nanoparticle-Modified Poly(Phenylene Sulphide/ Carbon Fiber Laminates: Thermomechanical Behaviour

    Directory of Open Access Journals (Sweden)

    Ana M. Díez-Pascual

    2013-07-01

    Full Text Available Carbon fiber (CF-reinforced high-temperature thermoplastics such as poly(phenylene sulphide (PPS are widely used in structural composites for aerospace and automotive applications. The porosity of CF-reinforced polymers is a very important topic for practical applications since there is a direct correlation between void content and mechanical properties. In this study, inorganic fullerene-like tungsten disulphide (IF-WS2 lubricant nanoparticles were used to manufacture PPS/IF-WS2/CF laminates via melt-blending and hot-press processing, and the effect of IF-WS2 loading on the quality, thermal and mechanical behaviour of the hybrid composites was investigated. The addition of IF-WS2 improved fiber impregnation, resulting in lower degree of porosity and increased delamination resistance, compression and flexural properties; their reinforcement effect was greater at temperatures above the glass transition (Tg. IF-WS2 contents higher than 0.5 wt % increased Tg and the heat deflection temperature while reduced the coefficient of thermal expansion. The multiscale laminates exhibited higher ignition point and notably reduced peak heat release rate compared to PPS/CF. The coexistence of micro- and nano-scale fillers resulted in synergistic effects that enhanced the stiffness, strength, thermal conductivity and flame retardancy of the matrix. The results presented herein demonstrate that the IF-WS2 are very promising nanofillers to improve the thermomechanical properties of conventional thermoplastic/CF composites.

  17. Effect of inorganic carbon on anaerobic ammonium oxidation enriched in sequencing batch reactor

    Institute of Scientific and Technical Information of China (English)

    Liao Dexiang; Li Xiaoming; Yang Qi; Zeng Guangming; Guo Liang; Yue Xiu

    2008-01-01

    The present lab-scale research reveals the enrichment of anaerobic ammonium oxidation microorganism from methanogenic anaerobic granular sludge and the effect of inorganic carbon (sodium bicarbonate) on anaerobic ammonium oxidation. The enrichment of anammox bacteria was carried out in a 7.0-L SBR and the effect of bicarbonate on anammox was conducted in a 3.0-L SBR. Research results , especially the biomass, showed first signs of anammox activity after 54 d cultivation with synthetic wastewater, when the pH was controlled between 7.5 and 8.3, the temperature was 35℃. The anammox activity increased as the influent bicarbonate concentration increased from 1.0 to 1.5 g/L and then, was inhibited as the bicarbonate concentration approached 2.0 g/L. However, the activity could be restored by the reduction of bicarbonate concentration to 1.0 g/L, as shown by rapid conversion of ammonium, and nitrite and nitrate production with normal stoichiometry. The optimization of the bicarbonate concentration in the reactor could increase the anammox rate up to 66.4 mgN/(L·d).

  18. Influence of increasing dissolved inorganic carbon concentrations and decreasing pH on chemolithoautrophic bacteria from oxic-sulfidic interfaces

    Science.gov (United States)

    Mammitzsch, K.; Jost, G.; Jürgens, K.

    2012-12-01

    Increases in the dissolved inorganic carbon (DIC) concentration are expected to cause a decrease in the pH of ocean waters, a process known as ocean acidification. In oxygen-deficient zones this will add to already increased DIC and decreased pH values. It is not known how this might affect microbial communities and microbially mediated processes. In this study, the potential effects of ocean acidification on chemolithoautotrophic prokaryotes of marine oxic-anoxic transition zones were investigated, using the chemoautotrophic denitrifying ɛ-proteobacterium "Sulfurimonas gotlandica" strain GD1 as a model organism. This and related taxa use reduced sulfur compounds, e.g. sulfide and thiosulfate, as electron donors and were previously shown to be responsible for nitrate removal and sulfide detoxification in redox zones of the Baltic Sea water column but occur also in other oxygen-deficient marine systems. Bacterial cell growth within a broad range of DIC concentrations and pH values was monitored and substrate utilization was determined. The results showed that the DIC saturation concentration for growth was already reached at 800 μM, which is well below in situ DIC levels. The pH optimum was between 6.6 and 8.0. Within a pH range of 6.6-7.1 there was no significant difference in substrate utilization; however, at lower pH values cell growth decreased sharply and cell-specific substrate consumption increased. These findings suggest that a direct effect of ocean acidification, with the predicted changes in pH and DIC, on chemolithoautotrophic bacteria such as "S. gotlandica" str. GD1 is generally not very probable.

  19. Influence of increasing dissolved inorganic carbon concentrations and decreasing pH on chemolithoautrophic bacteria from oxic-sulfidic interfaces

    Directory of Open Access Journals (Sweden)

    K. Mammitzsch

    2012-12-01

    Full Text Available Increases in the dissolved inorganic carbon (DIC concentration are expected to cause a decrease in the pH of ocean waters, a process known as ocean acidification. In oxygen-deficient zones this will add to already increased DIC and decreased pH values. It is not known how this might affect microbial communities and microbially mediated processes. In this study, the potential effects of ocean acidification on chemolithoautotrophic prokaryotes of marine oxic-anoxic transition zones were investigated, using the chemoautotrophic denitrifying ε-proteobacterium "Sulfurimonas gotlandica" strain GD1 as a model organism. This and related taxa use reduced sulfur compounds, e.g. sulfide and thiosulfate, as electron donors and were previously shown to be responsible for nitrate removal and sulfide detoxification in redox zones of the Baltic Sea water column but occur also in other oxygen-deficient marine systems. Bacterial cell growth within a broad range of DIC concentrations and pH values was monitored and substrate utilization was determined. The results showed that the DIC saturation concentration for growth was already reached at 800 μM, which is well below in situ DIC levels. The pH optimum was between 6.6 and 8.0. Within a pH range of 6.6–7.1 there was no significant difference in substrate utilization; however, at lower pH values cell growth decreased sharply and cell-specific substrate consumption increased. These findings suggest that a direct effect of ocean acidification, with the predicted changes in pH and DIC, on chemolithoautotrophic bacteria such as "S. gotlandica" str. GD1 is generally not very probable.

  20. Dissolved inorganic carbon, pH, temperature, salinity and other variables collected from time series and surface observations using Moored Autonomous Dissolved Inorganic Carbon (MADIC) System, Sunburst SAMI2 pH sensor, and other instruments from Kewalo Buoy near the coast of Honolulu, Hawaii from 2013-10-31 to 2014-06-15 (NCEI Accession 0132048)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — To expand the number of tools available for autonomous carbonate system observations, we have developed a robust surface ocean dissolved inorganic carbon (DIC)...

  1. Irreversible adsorption of phenolic compounds by activated carbons

    International Nuclear Information System (INIS)

    Studies were undertaken to determine the reasons why phenolic sorbates can be difficult to remove and recover from activated carbons. The chemical properties of the sorbate and the adsorbent surface, and the influences of changes in the adsorption and desorption conditions were investigated. Comparison of isotherms established after different contact times or at different temperatures indicated that phenolic compounds react on carbon surfaces. The reaction rate is a strong function of temperature. Regeneration of carbons by leaching with acetone recovered at least as much phenol as did regeneration with other solvents or with displacers. The physiochemical properties of adsorbents influences irreversible uptakes. Sorbates differed markedly in their tendencies to undergo irreversible adsorption. 64 refs., 47 figs., 32 tabs

  2. Photoassisted carbon dioxide reduction and formation of twoand three-carbon compounds. [prebiological photosynthesis

    Science.gov (United States)

    Halmann, M.; Aurian-Blajeni, B.; Bloch, S.

    1981-01-01

    The photoassisted reduction of aqueous carbon dioxide in the presence of naturally occurring minerals is investigated as a possible abiotic precursor of photosynthesis. Aqueous carbon dioxide saturated suspensions or surfaces of the minerals nontronite, bentonite, anatase, wolframite, molybdenite, minium, cinnabar and hematite were irradiated with high-pressure mercury lamps or sunlight. Chemical analyses reveal the production of formic acid, formaldehyde, methanol and methane, and the two and three-carbon compounds glyoxal (CHOCHO) and malonaldehyde (CH2(CHO)2). It is suggested that such photosynthetic reactions with visible light in the presence of semiconducting minerals may provide models for prebiological carbon and nitrogen fixation in both oxidized and reduced atmospheres.

  3. Stable carbon isotopes of dissolved inorganic carbon for a zonal transect across the subpolar North Atlantic Ocean in summer 2014

    Science.gov (United States)

    Humphreys, Matthew P.; Greatrix, Florence M.; Tynan, Eithne; Achterberg, Eric P.; Griffiths, Alex M.; Fry, Claudia H.; Garley, Rebecca; McDonald, Alison; Boyce, Adrian J.

    2016-06-01

    The stable carbon isotope composition of dissolved inorganic carbon (δ13CDIC) in seawater was measured in samples collected during June-July 2014 in the subpolar North Atlantic. Sample collection was carried out on the RRS James Clark Ross cruise JR302, part of the "Radiatively Active Gases from the North Atlantic Region and Climate Change" (RAGNARoCC) research programme. The observed δ13CDIC values for cruise JR302 fall in a range from -0.07 to +1.95 ‰, relative to the Vienna Pee Dee Belemnite standard. From duplicate samples collected during the cruise, the 1σ precision for the 341 results is 0.08 ‰, which is similar to our previous work and other studies of this kind. We also performed a cross-over analysis using nearby historical δ13CDIC data, which indicated that there were no significant systematic offsets between our measurements and previously published results. We also included seawater reference material (RM) produced by A. G. Dickson (Scripps Institution of Oceanography, USA) in every batch of analysis, enabling us to improve upon the calibration and quality-control procedures from a previous study. The δ13CDIC is consistent within each RM batch, although its value is not certified. We report δ13CDIC values of 1.15 ± 0.03 ‰ and 1.27 ± 0.05 ‰ for batches 141 and 144 respectively. Our JR302 δ13CDIC data can be used - along with measurements of other biogeochemical variables - to constrain the processes that control DIC in the interior ocean, in particular the oceanic uptake of anthropogenic carbon dioxide and the biological carbon pump. Our δ13CDIC results are available from the British Oceanographic Data Centre - http://dx.doi.org/10.5285/22235f1a-b7f3-687f-e053-6c86abc0c8a6" target="_blank">doi:10.5285/22235f1a-b7f3-687f-e053-6c86abc0c8a6.

  4. Effects of inorganic sulfur addition on fluxes of volatile sulfur compounds in Sphagnum peatlands

    Science.gov (United States)

    Demello, William Zamboni; Hines, Mark E.; Bayley, Suzanne E.

    1992-01-01

    Short and long-term impacts of increased S deposition on fluxes of volatile S compounds (VSC's) from Sphagnum peatlands were investigated in an artificially acidified (sulfuric and nitric acids) poor fen (Mire 239) at the Experimental Lakes Area (ELA), Ontario, Canada. Additional experiments were conducted in a poor fen (Sallie's Fen) in Barrington, NH, USA. At Mire 239, emissions of VSC's were monitored, before and after acidification, at control (unacidified) and experimental sections within two major physiographic zones of the mire (oligotrophic and minerotrophic). The experimental segments of the mire received S amendments since 1983, in amounts equivalent to the annual S deposition in the highest polluted areas of Canada and U.S. Dimethyl sulfide (DMS) was the predominant VSC released from the mire and varied largely with time and space (i.e., from 2.5 to 127 nmol/m(sup -2)h(sup -1)). Sulfur addition did not affect DMS emissions in a period of hours to a few days, although it stimulated production of DMS and MSH in the anoxic surficial regions of the peat. DMS emissions in the experimental oligotrophic segment of the mire was approximately 3-fold greater than in the control oligotrophic segment, and approximately 10-fold greater than in the minerotrophic zones. These differences could be due to a combination of differences in types of vegetation, nutritional status, and S input. At Sallie's Fen, DMS fluxes were approximately 8 times higher from a Sphagnum site than from a bare peat site. Fluxes of VSC's were not significantly affected by sulfate amendments at both sites, while DMS and MSH concentrations increases greatly with time in the top 10 cm of the peat column. Our data indicated that although Sphagnum is not the direct source of DMS released from Sphagnum peatlands, it might play a role in regulating DMS emissions to the atmosphere.

  5. Measurements of the dissolved inorganic carbon system and associated biogeochemical parameters in the Canadian Arctic, 1974–2009

    Directory of Open Access Journals (Sweden)

    K. E. Giesbrecht

    2013-06-01

    Full Text Available We have assembled and conducted primary quality control on previously publically-unavailable water column measurements of the dissolved inorganic carbon system and associated biogeochemical parameters (oxygen, nutrients, etc. made on 25 cruises in the subarctic and Arctic regions dating from as far back as 1974. The measurements are primarily from the western side of the Canadian Arctic, but also include data ranging from the North Pacific to the Gulf of St. Lawrence. The data were subjected to primary quality control (QC to identify outliers and obvious errors. This dataset incorporates over four thousand individual measurements of total inorganic carbon (TIC, alkalinity, and pH from the Canadian Arctic over a period of more than 30 yr and provides an opportunity to increase our understanding of temporal changes in the inorganic carbon system in northern waters and the Arctic Ocean. The dataset is available for download on the CDIAC website: http://cdiac.ornl.gov/ftp/oceans/IOS_Arctic_Database/ (doi:10.3334/CDIAC/OTG.IOS_ARCT_CARBN.

  6. Role of habitat and great oxidation event on the occurrence of three multisubunit inorganic carbon-uptake systems in cyanobacteria

    Indian Academy of Sciences (India)

    Vandana Tomar; Gurpreet Kaur Sidhu; Panchsheela Nogia; Rajesh Mehrotra; Sandhya Mehrotra

    2016-03-01

    The oxygenase reaction catalyzed by RuBisCO became an issue only after the evolution of the oxygenic photosynthesis incyanobacteria. Several strategies were developed by autotrophic organisms as an evolutionary response to increase oxygenlevels to help RuBisCO maximize its net carboxylation rate. One of the crucial advancements in this context was the developmentof more efficient inorganic carbon transporters which could help in increasing the influx of inorganic carbon (Ci) at thesite of CO2 fixation.We conducted a survey to find out the genes coding for cyanobacterial Ci transporters in 40 cyanobacterialphyla with respect to transporters present in Gloeobacter violaceous PCC 7421, an early-diverging cyanobacterium. Anattempt was also made to correlate the prevalence of the kind of transporter present in the species with its habitat. Basically,two types of cyanobacterial inorganic carbon transporters exist, i.e. bicarbonate transporters and CO2-uptake systems. Thetransporters also show variation in context to their structure as some exist as single subunit proteins (BicA and SbtA), whileothers exist as multisubunit proteins (namely BCT1, NdhI3 and NdhI4). The phylogeny and distribution of the former havebeen extensively studied and the present analysis provides an insight into the latter ones. The in silico analysis of the genesunder study revealed that their distribution was greatly influenced by the habitat and major environmental changes such as thegreat oxidation event (GOE) in the course of their evolution.

  7. Organic, elemental and inorganic carbon in particulate matter of six urban environments in Europe

    Directory of Open Access Journals (Sweden)

    M. Sillanpää

    2005-01-01

    Full Text Available A series of 7-week sampling campaigns were conducted in urban background sites of six European cities as follows: Duisburg (autumn, Prague (winter, Amsterdam (winter, Helsinki (spring, Barcelona (spring and Athens (summer. The campaigns were scheduled to include seasons of local public health concern due to high particulate concentrations or findings in previously conducted epidemiological studies. Aerosol samples were collected in parallel with two identical virtual impactors that divide air particles into fine (PM2.5 and coarse (PM2.5-10 size ranges. From the collected filter samples, elemental (EC and organic (OC carbon contents were analysed with a thermal-optical carbon analyser (TOA; total Ca, Ti, Fe, Si, Al and K by energy dispersive X-ray fluorescence (ED-XRF; As, Cu, Ni, V, and Zn by inductively coupled plasma mass spectrometry (ICP/MS; Ca2+, succinate, malonate and oxalate by ion chromatography (IC; and the sum of levoglucosan+galactosan+mannosan (∑MA by liquid chromatography mass spectrometry (LC/MS. The campaign means of PM2.5 and PM2.5-10 were 8.3-29.6 µg m-3 and 5.4-28.7 µg m-3, respectively. The contribution of particulate organic matter (POM to PM2.5 ranged from 21% in Barcelona to 54% in Prague, while that to PM2.5-10 ranged from 10% in Barcelona to 27% in Prague. The contribution of EC was higher to PM2.5 (5-9% than to PM2.5-10 (1-6% in all the six campaigns. Carbonate (C(CO3, that interferes with the TOA analysis, was detected in PM2.5-10 of Athens and Barcelona but not elsewhere. It was subtracted from the OC by a simple integration method that was validated. The CaCO3 accounted for 55% and 11% of PM2.5-10 in Athens and Barcelona, respectively. It was anticipated that combustion emissions from vehicle engines affected the POM content in PM2.5 of all the six sampling campaigns, but a comparison of mass concentration ratios of the selected inorganic and organic tracers of common sources of organic material to POM suggested

  8. Improved quality control of carbon-14 labelled compounds

    International Nuclear Information System (INIS)

    IUT Ltd is a producer of carbon-14 labelled organic compounds like benzene, methanol, phenol, formaldehyde, Na-acetates and also special ordered compounds. The quality control of these compounds is carried out by means of HPLC and GC-MS due to chemical purity. Molar activity was determined by Liquid Scintillation Counting and HPLC being equipped by a radioactivity detector. Unfortunately the accuracy of the activity determination was arrived only ±4% relatively. This error is too high because of the large dilution factors. In respect of the IUT accreditation as an analytical laboratory in Germany the accuracy had to be improved remarkably. Therefore the GC-MS-determination of molar activities of labelled compounds is used as the 14C-labelled compound. A special evaluation code is used to determine the enrichment values relative to the unlabelled molecules. Taking into account the results of GC-MS the accuracy of molar activity determination is improved to ±2%. The spectra evaluation is demonstrated and some examples are discussed

  9. Beyond temperature: Clumped isotope signatures in dissolved inorganic carbon species and the influence of solution chemistry on carbonate mineral composition

    Science.gov (United States)

    Tripati, Aradhna K.; Hill, Pamela S.; Eagle, Robert A.; Mosenfelder, Jed L.; Tang, Jianwu; Schauble, Edwin A.; Eiler, John M.; Zeebe, Richard E.; Uchikawa, Joji; Coplen, Tyler B.; Ries, Justin B.; Henry, Drew

    2015-10-01

    "Clumped-isotope" thermometry is an emerging tool to probe the temperature history of surface and subsurface environments based on measurements of the proportion of 13C and 18O isotopes bound to each other within carbonate minerals in 13C18O16O22- groups (heavy isotope "clumps"). Although most clumped isotope geothermometry implicitly presumes carbonate crystals have attained lattice equilibrium (i.e., thermodynamic equilibrium for a mineral, which is independent of solution chemistry), several factors other than temperature, including dissolved inorganic carbon (DIC) speciation may influence mineral isotopic signatures. Therefore we used a combination of approaches to understand the potential influence of different variables on the clumped isotope (and oxygen isotope) composition of minerals. We conducted witherite precipitation experiments at a single temperature and at varied pH to empirically determine 13C-18O bond ordering (Δ47) and δ18O of CO32- and HCO3- molecules at a 25 °C equilibrium. Ab initio cluster models based on density functional theory were used to predict equilibrium 13C-18O bond abundances and δ18O of different DIC species and minerals as a function of temperature. Experiments and theory indicate Δ47 and δ18O compositions of CO32- and HCO3- ions are significantly different from each other. Experiments constrain the Δ47-δ18O slope for a pH effect (0.011 ± 0.001; 12 ⩾ pH ⩾ 7). Rapidly-growing temperate corals exhibit disequilibrium mineral isotopic signatures with a Δ47-δ18O slope of 0.011 ± 0.003, consistent with a pH effect. Our theoretical calculations for carbonate minerals indicate equilibrium lattice calcite values for Δ47 and δ18O are intermediate between HCO3- and CO32-. We analyzed synthetic calcites grown at temperatures ranging from 0.5 to 50 °C with and without the enzyme carbonic anhydrase present. This enzyme catalyzes oxygen isotopic exchange between DIC species and is present in many natural systems. The two

  10. Experimental and theoretical study of AC electrical conduction mechanisms of Organic-inorganic hybrid compound Bis (4-acetylanilinium) tetrachlorocadmiate (II)

    Science.gov (United States)

    Jellibi, A.; Chaabane, I.; Guidara, K.

    2016-06-01

    A new organic-inorganic bis (4-acetylaniline) tetrachlorocadmate [C8H10NO]2[CdCl4] can be obtained by slow evaporation at room temperature and characterized by X-ray powder diffraction. It crystallized in an orthorhombic system (Cmca space group). The material electrical properties were characterized by impedance spectroscopy technique in the frequency range from 209 Hz-5 MHz and temperature 413 to 460 K. Besides, the impedance plots show semicircle arcs at different temperatures and an electrical equivalent circuit has been proposed to interpret the impedance results. The circuits consist of the parallel combination of a resistance (R), capacitance (C) and fractal capacitance (CPE). The variation of the exponent s as a function of temperature suggested that the conduction mechanism in Bis (4-acetylanilinium) tetrachlorocadmiate compound is governed by two processes which can be ascribed to a hopping transport mechanism: correlated barrier hopping (CBH) model below 443 K and the small polaron tunneling (SPT) model above 443 K.

  11. Thermal properties study on the ablation materials of inorganic silicon compound from organosilicone in high percent conversion

    Institute of Scientific and Technical Information of China (English)

    CUI MengZhong; WANG WenHua

    2007-01-01

    The new type of silicone rubber prepared by organosilicon polymer containing special groups presents the tensile strength of 3.92 MPa and the elongation at break of 285%. Compared with Sylgard(r)184 silicone rubber (Dow Corning Corporation), it has better high temperature resistance and almost no weightlessness from room temperature to 430℃. Thermogravimetric analysis was conducted to research the thermal degradation at different temperatures and the heat pyrolysis products were trace determined by FT-IR. The results show that with the increase of temperature, the organic groups of products are gradually decomposed. Organosilicon rubber is gradually changed into the typical inorganic SiCO compounds in the process of pyrolysis. Elemental analysis and X-ray photoelectron spectroscopy results show that the pyrolyzates are mainly composed of Si, C and O elements above 1050℃. X-ray diffraction analysis showes that partial β-SiC crystal structure is brought about gradually from the pyrolysis products at 1050℃ to 1500℃ under nitrogen atmosphere. With the treatment temperature rising, the crystallinity of SiC and cristobalite obviously increases.

  12. Air-sea gas transfer in a shallow, flowing and coastal environment estimated by dissolved inorganic carbon and dissolved oxygen analyses

    Digital Repository Service at National Institute of Oceanography (India)

    Abe, O.; Watanabe, A.; Sarma, V.V.S.S.; Matsu, Y.; Yamano, H.; Yoshida, N.; Saino, T.

    We estimated gas exchange rates in Kabira Reef at Ishigaki Island, southwest Japan, using a mass balance calculation with dual ‘biological’ tracers: dissolved inorganic carbon (DIC) and dissolved oxygen (DO). The nighttime results allowed us...

  13. Sources and Dynamics of Inorganic Carbon within the Upper Reaches of the Xi River Basin, Southwest China

    Science.gov (United States)

    Zou, Junyu

    2016-01-01

    The carbon isotopic composition (δ13C) of dissolved and particulate inorganic carbon (DIC; PIC) was used to compare and analyze the origin, dynamics and evolution of inorganic carbon in two headwater tributaries of the Xi River, Southwest China. Carbonate dissolution and soil CO2 were regarded as the primary sources of DIC on the basis of δ13CDIC values which varied along the Nanpan and Beipan Rivers, from −13.9‰ to 8.1‰. Spatial trends in DIC differed between the two rivers (i.e., the tributaries), in part because factors controlling pCO2, which strongly affected carbonate dissolution, differed between the two river basins. Transport of soil CO2 and organic carbon through hydrologic conduits predominately controlled the levels of pCO2 in the Nanpan River. However, pCO2 along the upper reaches of the Nanpan River also was controlled by the extent of urbanization and industrialization relative to agriculture. DIC concentrations in the highly urbanized upper reaches of the Nanpan River were typical higher than in other carbonate-dominated areas of the upper Xi River. Within the Beipan River, the oxidation of organic carbon is the primary process that maintains pCO2 levels. The pCO2 within the Beipan River was more affected by sulfuric acid from coal industries, inputs from a scenic spot, and groundwater than along the Nanpan River. With regards to PIC, the contents and δ13C values in the Nanpan River were generally lower than those in the Beipan River, indicating that chemical and physical weathering contributes more marine carbonate detritus to the PIC along the Beipan River. The CO2 evasion flux from the Nanpan River was higher than that in the Beipan River, and generally higher than along the middle and lower reaches of the Xi River, demonstrating that the Nanpan River is an important net source of atmospheric CO2 in Southwest China. PMID:27513939

  14. Influence of sulfur compounds on the terrestrial carbon cycle

    Science.gov (United States)

    Eliseev, A. V.

    2015-11-01

    Using the climate model developed at the A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences (IAP RAS CM), numerical experiments have been conducted in line with the Coupled Model Intercomparison Project Phase 5 (CMIP5), but scaling the anthropogenic emissions of sulfur compounds into the troposphere by ±25%. Two types of impacts of sulfur compounds on climate and the global carbon cycle are considered: climate impact (CI, associated with the influence of tropospheric sulfates on climate and, as a consequence, on the carbon cycle characteristics) and ecological impact (EI, associated with the influence of SO2 on the rate of photosynthesis of terrestrial plants). The climate impact was found to be generally more important than the ecological one. However, in a number of regions, the EI is comparable to CI, including in the southeast parts of North America and, especially, of Asia. The contribution of EI to the change in global characteristics of terrestrial ecosystems in the 20th century is likewise considerable. The CI is generally more sensitive to the uncertainty in anthropogenic emissions of sulfur compounds into the troposphere than the EI.

  15. Archaea and Bacteria in deep lake hypolimnion: in situ dark inorganic carbon uptake

    Directory of Open Access Journals (Sweden)

    Cristiana Callieri

    2014-02-01

    Full Text Available The interest for microorganisms inhabiting the hypolimnion and for their role in biogeochemical cycles of lakes is considerable, but knowledge is far from complete. The presence of chemolithoautotrophic Bacteria and mesophilic Archaea (e.g., Thaumarchaeota assimilating inorganic carbon in the deep hypolimnion of lakes has been ascertained. We measured, for the first time at 350 m in Lake Maggiore (Northern Italy, the prokaryotic in situ dark [14C]HCO3 incorporation with a new custom-made apparatus, which takes samples and adds tracers in situ. Thereby stress factors affecting prokaryotes during sample recovery from the depth were avoided. We tested the new instrument at different depths and conditions, performing parallel conventional on board incubations. We found that dark [14C]HCO3 incorporations had lower standard deviation in in situ incubations with respect to the on board ones, but their means were not statistically different. At 350 m we estimated an uptake of 187.7±15 μg C m–3 d–1, which is in line with the published uptake rates in aquatic systems. By inhibiting the bacterial metabolism, we found that Archaea were responsible for 28% of the total CO2 uptake. At the same depth, Thaumarchaeota, on average, constituted 11% of total DAPI counts. Dark [14C]HCO3 incorporation integrated along the aphotic water column was 65.8±5.2 mg C m–2 d–1 which corresponds to 87% of picophytoplanktonic autotrophic fixation in the euphotic layer. This study provides the first evidence of Bacteria and Archaea dark CO2 fixation in the deep hypolimnion of a subalpine lake and indicates a potentially significant prokaryotic CO2 sink.

  16. Soil resource availability impacts microbial response to organic carbon and inorganic nitrogen inputs

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei-jian; W.ZHU; S.HU

    2005-01-01

    Impacts of newly added organic carbon (C) and inorganic nitrogen (N) on the microbial utilization of soil organic matter are important in determining the future C balance of terrestrial ecosystems. We examined microbial responses to cellulose and ammonium nitrate additions in three soils with very different C and N availability. These soils included an organic soil( 14.2% total organic C, with extremely high extractable N and low labile C), a forest soi1(4.7% total organic C, with high labile C and extremely low extractable N),and a grassland soil (1.6% total organic C, with low extractable N and labile C). While cellulose addition alone significantly enhanced microbial respiration and biomass C and N in the organic and grassland soils, it accelerated only the microbial respiration in the highly-N limited forest soil. These results indicated that when N was not limited, C addition enhanced soil respiration by stimulating both microbial growth and their metabolic activity. New C inputs lead to elevated C release in all three soils, and the magnitude of the enhancement was higher in the organic and grassland soils than the forest soil. The addition of cellulose plus N to the forest and grassland soils initially increased the microbial biomass and respiration rates, but decreased the rates as time progressed. Compared to cellulose addition alone,cellulose plus N additions increased the total C-released in the grassland soil, but not in the forest soil. The enhancement of total Creleased induced by C and N addition was less than 50% of the added-C in the forest soil after 96 d of incubation, in contrast to 87.5%and 89.0% in the organic and grassland soils. These results indicate that indigenous soil C and N availability substantially impacts the allocation of organic C for microbial biomass growth and/or respiration, potentially regulating the turnover rates of the new organic C inputs.

  17. Climatological variations of total alkalinity and total inorganic carbon in the Mediterranean Sea surface waters

    Directory of Open Access Journals (Sweden)

    E. Gemayel

    2015-08-01

    Full Text Available A compilation of several cruises data from 1998 to 2013 was used to derive polynomial fits that estimate total alkalinity (AT and total inorganic carbon (CT from measurements of salinity and temperature in the Mediterranean Sea surface waters. The optimal equations were chosen based on the 10-fold cross validation results and revealed that a second and third order polynomials fit the AT and CT data respectively. The AT surface fit showed an improved root mean square error (RMSE of ±10.6 μmol kg−1. Furthermore we present the first annual mean CT parameterization for the Mediterranean Sea surface waters with a RMSE of ±14.3 μmol kg−1. Excluding the marginal seas of the Adriatic and the Aegean, these equations can be used to estimate AT and CT in case of the lack of measurements. The seven years averages (2005–2012 mapped using the quarter degree climatologies of the World Ocean Atlas 2013 showed that in surface waters AT and CT have similar patterns with an increasing eastward gradient. The surface variability is influenced by the inflow of cold Atlantic waters through the Strait of Gibraltar and by the oligotrophic and thermohaline gradient that characterize the Mediterranean Sea. The summer-winter seasonality was also mapped and showed different patterns for AT and CT. During the winter, the AT and CT concentrations were higher in the western than in the eastern basin, primarily due to the deepening of the mixed layer and upwelling of dense waters. The opposite was observed in the summer where the eastern basin was marked by higher AT and CT concentrations than in winter. The strong evaporation that takes place in this season along with the ultra-oligotrophy of the eastern basin determines the increase of both AT and CT concentrations.

  18. Seasonal distribution of dissolved inorganic carbon and net community production on the Bering Sea shelf

    Directory of Open Access Journals (Sweden)

    J. T. Mathis

    2010-05-01

    Full Text Available In order to assess the current state of net community production (NCP in the southeastern Bering Sea, we measured the spatio-temporal distribution and controls on dissolved inorganic carbon (DIC concentrations in spring and summer of 2008 across six shelf domains defined by differing biogeochemical characteristics. DIC concentrations were tightly coupled to salinity in spring and ranged from ~1900 μmoles kg−1 over the inner shelf to ~2400 μmoles kg−1 in the deeper waters of the Bering Sea. In summer, DIC concentrations were lower due to dilution from sea ice melt, terrestrial inputs, and primary production. Concentrations were found to be as low ~1800 μmoles kg−1 over the inner shelf. We found that DIC concentrations were drawn down 30–150 μmoles kg−1 in the upper 30 m of the water column due to primary production and calcium carbonate formation between the spring and summer occupations. Using the seasonal drawdown of DIC, estimated rates of NCP on the inner, middle, and outer shelf averaged 28 ± 9 mmoles C m−2 d−1. However, higher rates of NCP (40–47 mmoles C m−2 d−1 were observed in the "Green Belt" where the greatest confluence of nutrient-rich basin water and iron-rich shelf water occurs. We estimated that in 2008, total NCP across the shelf was on the order of ~96 Tg C yr−1. Due to the paucity of consistent, comparable productivity data, it is impossible at this time to quantify whether the system is becoming more or less productive. However, as changing climate continues to modify the character of the Bering Sea, we have shown that NCP can be an important indicator of how the ecosystem is functioning.

  19. Enhancement of inorganic Martian dust simulant with carbon component and its effects on key characteristics of glutamatergic neurotransmission

    Science.gov (United States)

    Borisova, Tatiana; Krisanova, Natalia; Nazarova, Anastasiya; Borysov, Arseniy; Pastukhov, Artem; Pozdnyakova, Natalia; Dudarenko, Marina

    2016-07-01

    Evidence on the past existence of subsurface organic-bearing fluids on Mars was recently achieved basing on the investigation of organic carbon from the Tissint Martian meteorite (Lin et al., 2014). Tremendous amount of meteorites containing abundant carbon and carbon-enriched dust particles have reached the Earth daily (Pizzarello and Shock 2010). National Institute of Environmental Health Sciences/National Institute of Health panel of research scientists revealed recently that accumulating evidences suggest that nano-sized air pollution may have a significant impact on central nervous system in health and disease (Block et al., Neurotoxicology, 2012). During inhalation, nano-/microsized particles are efficiently deposited in nasal, tracheobronchial, and alveolar regions and can be transported to the central nervous system (Oberdorster et al., 2004). Based on above facts, the aims of this study were: 1) to upgrade inorganic Martian dust stimulant derived from volcanic ash (JSC-1a/JSC, ORBITEC Orbital Technologies Corporation, Madison, Wisconsin) by the addition of carbon components, that is, nanodiamonds; 2) to analyse acute effects of upgraded stimulant on the key characteristic of synaptic neurotransmission and to compare its effects with those of inorganic dust and carbon components per se. Acute administration of carbon-containing Martian dust analogue resulted in a significant decrease in Na+-dependent uptake of L-[14C]glutamate that is the major excitatory neurotransmitter in the central nervous system (CNS). The ambient level of the neurotransmitter in the preparation of isolated rat brain nerve terminals increased in the presence of carbon-contained Martian dust analogue. This fact indicated that carbon component of native Martian dust can have deleterious effects on extracellular glutamate homeostasis in the CNS, and so glutamatergic neurtransmission.

  20. Distributions of dissolved organic and inorganic carbon and radiocarbon in the eastern North Pacific continental margin

    Science.gov (United States)

    Bauer, James E.; Druffel, Ellen R. M.; Wolgast, David M.; Griffin, Sheila; Masiello, Caroline A.

    Temporal variations in the natural radiocarbon ( 14C) signatures of dissolved organic and inorganic carbon (DOC and DIC, respectively) in seawater have been studied previously (Druffel, E.R.M., Bauer, J.E., Williams, P.M., Griffin, S., Wolgast, D.M., 1996. Seasonal variability of radiocarbon in particulate organic carbon in the northeast Pacific. J. Geophys. Res. 101, 20 543-20 552; Bauer, J.E., Druffel, E.R.M., Williams, P.M., Wolgast, D.M., Griffin, S., 1998. Temporal variability in dissolved organic carbon and radiocarbon in the eastern North Pacific Ocean. J. Geophys. Res. 103, 2867-2882) at a long-term time-series station (Sta. M: 32°N, 123W) in the eastern North Pacific located at the eastern edge of the North Pacific abyssal plain. In June 1995 a transect was made from Sta. M inshore to approximately 500 m depth in order to evaluate the distributions of 14C in DOC and DIC from the abyssal plain to the upper continental slope. Concentrations and Δ 14C values of DOC in mixed layer waters (25 and 85 m) decreased toward the upper slope. In deeper waters, concentrations and Δ 14C values were in general similar at all three sites. Differences in DOC concentrations and Δ 14C-DOC between Sta. M and the rise and upper slope sites were explained in part by the mixing of DOC and Δ 14C along constant density ( σt) surfaces. However, specific deviations from conservative behavior due to mixing were observed for Δ 14C-DOC at mesopelagic (˜700 m) and near-bottom (˜3600- 3900 m) depths of the continental rise. Comparable findings are reported for DIC, where σt-normalized concentrations and Δ 14C values in Sta. M, rise and upper slope waters were similar, with the exception of slight increases in concentrations and Δ 14C values in near-bottom waters of the rise. These observations indicate that both DOC and DIC in continental rise and slope surface waters of the eastern North Pacific Ocean margin are comprised of a component of actively upwelled material derived

  1. Kirishites, a new type of natural high-carbon compounds

    Science.gov (United States)

    Marin, Yu. B.; Skublov, G. T.; Yushkin, N. P.

    2010-01-01

    On the right-hand bank of the Volkhov River, in the natural area of tektite-like glasses (Volkhovites), fragments of shungites and slags with bunches of hairlike dark brownish enclosures were found. The filament thickness ranged from 20 to 100 μm, and separate “hairlines” were 3 cm in length. The composition of shungites and “hairlines” was found to be identical, which allowed us to consider the latter as aposhungite carbon formations. The high-carbon hairline structures associated with volkhovites are called kirishites. Kirishites are a new type of high-carbon structures that formed simultaneously with volkhovites in the case of explosion-type delivery of carbon slag and shungite fragments to the daylight surface during Holocene explosive activity. Under sharply reductive conditions, the slags partially melted, the melts were segregated, and carbonaceous-silicate and carbonaceous-ferriferous glasses formed with subsequent decompression-explosive liberation of carbon-supersaturated structures, which were extruded from shungite and slag fragments in the form of a resinoid mass. The “hairlines” were found to be zonal in structure: the central axial zones are composed of high-nitrogen hydrocarbon compounds, and peripheral regions are essentially carbonaceous with a high content of organic-mineral compounds and numerous microanomalies of petrogenic, volatile, rare, and ore elements. Infrared spectroscopy identified in kirishites proteinlike compounds, diagnosed in absorption bands (in cm-1) 600-720 (Amid V), 1200-1300 (Amid III), 1480-1590 (Amid II), 1600-1700 (Amid I), 3000-3800 (vibrations in NH2 and II groups). Gas chromatography, with the possibility of differentiation of left- and right-handed forms, revealed a broad spectrum of amino acids in kirishites, with their total content found to be the absolutely highest record for natural bitumens, an order of magnitude higher than the largest amino acid concentrations ever revealed in fibrous high

  2. Versatile Oxidation Methods for Organic and Inorganic Substrates Catalyzed by Platinum-Group Metals on Carbons.

    Science.gov (United States)

    Sawama, Yoshinari; Asai, Shota; Monguchi, Yasunari; Sajiki, Hironao

    2016-02-01

    Platinum-group metals on activated carbon catalysts, represented by Pd/C, Ru/C, Rh/C, etc., are widely utilized to accomplish green and sustainable organic reactions due to their favorable features, such as easy handling, recoverability, and reusability. The efficient oxidation methods of various organic compounds using heterogeneous platinum-group metals on carbons with or without added oxidants are summarized in this Personal Account. The oxidation of internal alkynes into diketones was effectively catalyzed by Pd/C in the presence of dimethyl sulfoxide and molecular oxygen or pyridine N-oxide. The Pd/C-catalyzed mild combustion of gaseous hydrogen with molecular oxygen provided hydrogen peroxide, which could be directly utilized for the oxidation of sulfide derivatives into sulfoxides. Furthermore, the Ru/C-catalyzed aerobic oxidation of primary and secondary alcohols gave the corresponding aldehydes and ketones, respectively. On the other hand, the dehydrogenative oxidation of secondary alcohols into ketones was achieved using Rh/C in water, and primary alcohols were effectively dehydrogenated by Pd/C in water under mildly reduced pressure to produce carboxylic acids. PMID:26666634

  3. Selective Sorption of Dissolved Organic Carbon Compounds by Temperate Soils

    Energy Technology Data Exchange (ETDEWEB)

    Jagadamma, Sindhu [ORNL; Mayes, Melanie [ORNL; Phillips, Jana Randolph [ORNL

    2012-01-01

    Physico-chemical sorption of dissolved organic carbon (DOC) on soil minerals is one of the major processes of organic carbon (OC) stabilization in soils, especially in deeper layers. The attachment of C on soil solids is related to the reactivity of the soil minerals and the chemistry of the sorbate functional groups, but the sorption studies conducted without controlling microbial activity may overestimate the sorption potential of soil. This study was conducted to examine the sorptive characteristics of a diverse functional groups of simple OC compounds (D-glucose, L-alanine, oxalic acid, salicylic acid, and sinapyl alcohol) on temperate climate soil orders (Mollisols, Ultisols and Alfisols) with and without biological degradative processes. Equilibrium batch experiments were conducted using 0-100 mg C L-1 at a solid-solution ratio of 1:60 for 48 hrs and the sorption parameters were calculated by Langmuir model fitting. The amount of added compounds that remained in the solution phase was detected by high performance liquid chromatography (HPLC) and total organic C (TOC) analysis. Soil sterilization was performed by -irradiation technique and experiments were repeated to determine the contribution of microbial degradation to apparent sorption. Overall, Ultisols did not show a marked preference for apparent sorption of any of the model compounds, as indicated by a narrower range of maximum sorption capacity (Smax) of 173-527 mg kg soil-1 across compounds. Mollisols exhibited a strong preference for apparent sorption of oxalic acid (Smax of 5290 mg kg soil-1) and sinapyl alcohol (Smax of 2031 mg kg soil-1) over the other compounds. The propensity for sorption of oxalic acid is mainly attributed to the precipitation of insoluble Ca-oxalate due to the calcareous nature of most Mollisol subsoils and its preference for sinapyl alcohol could be linked to the polymerization of this lignin monomer on 2:2 mineral dominated soils. The reactivity of Alfisols to DOC was in

  4. A Simple, Buoy Deployable Instrument for Accurate Dissolved Carbon Dioxide and Dissolved Inorganic Carbon Measurements in Freshwater and Marine Ecosystems

    Science.gov (United States)

    Browne, B. A.; Wyss, J. R.; Bowling, J. M.; Schueller, D. J.; Sherman, J. F.

    2007-05-01

    The need for better knowledge of (1) the oceanic sink for anthropogenic CO2, (2) the impact of anthropogenic CO2 on the oceanic CaCO3 system and (3) lake and stream metabolism in freshwater ecosystems is driving growing interest in real-time technologies to measure pCO2 and dissolved inorganic carbon (DIC). To be useful, these technologies must meet stringent data quality requirements of marine and freshwater biogeochemical research initiatives such as the Joint Global Ocean Flux Study, the Coral Reef Environmental Observatory Network, the National Ecological Observatory Network, and the Global Lake Ecological Observatory Network. In this presentation, we introduce new methodology and a device for unaccompanied measurement of pCO2 and DIC on research buoys or ocean/freshwater vessels. This small-scale, essentially "plug and play" device (shoe box size) has limited power requirements (≤1.8 amps) for continuous or discontinuous (e.g., one reading per hour) measurements and does not bio-foul. DIC and pCO2 can be measured in sequence using one infrared detector or in parallel using two. The accuracy and precision (Training requirements are minimal, providing flexibility for deployments on multiple vessel types. The device works by induction of ebullition. A hydrostatic pressure drop upstream of a pump causes a temporary condition of gas oversaturation. The collection cell downstream of the pump then acts like an overpressurized soda bottle. As pressure is released within the collection cell, the dissolved gas streams passively and reliably into the infrared detector(s), at a nominal rate of 7 mL per minute, carrying CO2 into the cell essentially at its in-situ partial pressure. To measure DIC, a valve allows for the addition of acid to the sampling line upstream of the pump converting all DIC to CO2 prior to reaching the collection cell. With the acid valve on, DIC is measured. With the acid valve off, pCO2 is measured. We will present data illustrating the accuracy

  5. Microdetermination of Mn, Fe, Co, Ni, Cu, Zn, Ag, Cd, Hg, Pb, Bi and U in inorganic and organometallic compounds with morpholinium morpholine-N-dithiocarboxylate.

    Science.gov (United States)

    Sakla, A B; Helmy, A A; Beyer, W; Harhhash, F E

    1979-07-01

    The chelates of morpholinium morpholine-N-dithiocarboxylate with manganese(II), iron(II), iron(III), cobalt(II), nickel, copper(II), zinc, silver, cadmium, mercury(II), lead, bismuth and uranium(VI) have been prepared and their compositions elucidated. Simple, accurate and relatively rapid procedures for the gravimetric and titrimetric microdetermination of these metals in inorganic and organometallic compounds are presented. PMID:18962480

  6. Interactions between carbon metabolism and the uptake and assimilation of inorganic nitrogen in Ankistrodesmus falcatus (Corda) Ralfs

    International Nuclear Information System (INIS)

    Nitrate uptake in nitrogen-limited Ankistrodesmus falcatus (Corba) Ralfs was found to be directly dependent on: (1) nitrate concentration; (2) the availability of carbon dioxide or recently synthesised carbon skeletons; (3) light intensity and (4) the presence of ammonium or metabolites of ammonium assimilation. Nitrate uptake was found to obey simple Michaelis-Menten kinetics. In the absence of carbon dioxide, nitrate uptake was destabilised and resulted in nitrate efflux from the cells. If the cells were pre-adapted to high levels of carbon dioxide, a decrease in the concentration of supplied carbon dioxide resulted in only a transient suppression of nitrate uptake. These results indicate that carbon dioxide was required for the stabilisation of the nitrate uptake system and that nitrate uptake, reduction and assimilation could proceed if supplies of recently synthesised carbon skeletons were available for subsequent ammonium incorporation into amino acids. It was concluded that the mobilisation of storage carbohydrate could provide the necessary reducing potential and ATP for nitrate uptake. The addition of ammonium to A. falcatus cells accumulating nitrate resulted in the immediate cessation of nitrate uptake and subsequent nitrate efflux from the cells. Assays of nitrate reductase activity indicated that the activity of the enzyme increased under nitrogen-limitation. Nitrogen-limited, nitrate-growth and ammonium-grown cultures of A. falcatus were used to determine the effects of nitrate and ammonium addition on photosynthetic oxygen exchange, carbon fixation and the path of carbon flow. The addition of these species of inorganic nitrogen resulted in the suppression of photosynthetic oxygen evolution and carbon fixation. Labelling with 14C was used during the carbon fixation studies

  7. Sediment Dynamics and Fate of Heavy Metals, Carbon, and Inorganic Matter in the Hudson Estuary, New York

    Science.gov (United States)

    Sritrairat, S.; Kenna, T. C.; Peteet, D. M.; Nguyen, K.; Perez, M.; Huang, Z.; Miller, A.

    2010-12-01

    The Hudson River Estuary is typical of a large, intensively used and modified estuary. Its watershed is an important resource for small communities along the river as well as large population centers such as the Metropolitan area of New York City. In addition to past industrial activities within the region that have resulted in many instances of environmental contamination, the estuary is at high risk for climatic and other anthropogenic changes. This study focuses on sediment dynamics and the fate of heavy metals, inorganic matter, and carbon in 27 sediment cores and 15 surface samples taken from wetlands and tributaries of the Hudson Estuary along a north-south transect from Troy, NY to New York harbor. Each site experiences different salinity, vegetation, landscape, and flow pattern. 1) We quantified and mapped the distribution of toxic heavy metals, including Pb, Cu, and Zn, in the estuary to examine the fate of these contaminants. Jamaica Bay and the East River sediments from New York City are the most contaminated with heavy metals among the sites analyzed. 2) We examined the sedimentation rate and sedimentation pattern, using pollution chronology along with radiometric methods. Sedimentation rates at 17 sites range from 0.26 - 2.63 cm/yr during the last century. Cores taken from high-energy or non-vegetated area are more likely to have a disturbed sedimentation pattern, and thus there is a higher risk of contaminant resuspension at those locations. 3) We quantified Ti and K concentration as a measure of the fluctuation of inorganic matter input and the fate of inorganic matter in the estuary. We quantified organic matter content with the Loss-on-Ignition (LOI) method at selected sites to identify carbon sequestration rate in the estuary. Inorganic matter content during the last century at most sites is significantly higher than that found prior to the European Settlements at the same location, suggesting increasing erosion and disturbances. However, more

  8. [Hydrochemistry and Dissolved Inorganic Carbon Stable Isotope of Shibing Dolomite Karst Area in Guizhou Province].

    Science.gov (United States)

    Xiao, Shi-zhen; Lan, Jia-cheng; Yuan, Dao-xian; Wang, Yun; Yang, Long; Ao, Xiang-hong

    2015-06-01

    Totally 49 water samples were collected in Shibing Dolomite Karst World Natural Heritage Site in Guizhou Province to analyze the characteristics and controlling factors of both the surface and underground waters, as well as the features and their origins of the dissolved inorganic carbon isotope. It was found that the pH of the study area was neutral to alkaline with low concentrations of total dissolved solids. The cations were dominated by Ca2+, Mg2 and anions by HCO3-, featured by HCO3-Ca x Mg type water. The ratios of Cl-, NO3- and SO4(2-) in the allogenic water from the shale area in the northern catchment were higher than those in autogenic water from the dolomite karst area, so did the concentration of Si. The SIc and SId of the allogenic waters in the shale area were negative. After the waters entered into and flew by the dolomite karst area, both the SIc and SId increased to over 0. It could be told by the water chemistry that the hydrochemistry was little impacted by the rainfall and human activities. The Gibbs plot revealed that the chemical composition of the waters was mainly controlled by rock weathering. The δ(13)C(DIC) of the surface waters ranged from -8.27% to -11.55% per hundred, averaging -9.45% per hundredo, while that of the underground waters ranged from -10.57% per hundred to -15.59% per hundred, averaging -12.04% per hundred, which was lighter than that of surface water. For the distribution features, it was found the δ(13)C(DIC), of the upper reaches of branches of Shangmuhe River was lighter than that of the lower reach, while that of the main river Shangmuhe River was relatively complex. Based on the mass balance of stable isotopes and the δ(13)C(DIC), the ratio of the origin of DIC of the ground water was calculated. It was found that 51.2% was from soil CO2, and 48.8% was from the rock itself. PMID:26387311

  9. Seasonal distribution of dissolved inorganic carbon and net community production on the Bering Sea shelf

    Directory of Open Access Journals (Sweden)

    J. T. Mathis

    2010-01-01

    Full Text Available The southeastern shelf of the Bering Sea is one of the ocean's most productive ecosystems and sustains more than half of the total US fish landings annually. However, the character of the Bering Sea shelf ecosystem has undergone a dramatic shift over the last several decades, causing notable increases in the dominance of temperate features coupled to the decline of arctic species and decreases in the abundance of commercially important organisms. In order to assess the current state of primary production in the southeastern Bering Sea, we measured the spatio-temporal distribution and controls on dissolved inorganic carbon (DIC concentrations in spring and summer of 2008 across six shelf domains defined by differing biogeochemical characteristics. DIC concentrations were tightly coupled to salinity in spring and ranged from ~1900 μmol kg−1 over the inner shelf to ~2400 μmol kg−1 in the deeper waters of the Bering Sea. In summer, DIC concentrations were lower due to dilution from sea ice melt and primary production. Concentrations were found to be as low ~1800 μmol kg−1 over the inner shelf. We found that DIC concentrations were drawn down 30–150 μmol kg−1 in the upper 30 m of the water column due to primary production between the spring and summer occupations. Using the seasonal drawdown of DIC, estimated rates of net community production (NCP on the inner, middle, and outer shelf averaged 28±10 mmol C m−2 d−1. However, higher rates of NCP (40–47 mmol C m−2 d−1 were observed in the ''Green Belt'' where the greatest confluence of nutrient-rich basin water and iron-rich shelf water occurs. We estimated that in 2008, total productivity across the shelf was on the order of ~105 Tg C yr−1. Due to the paucity of consistent, comparable productivity data, it is impossible at this time to quantify whether the system is becoming

  10. Synthesis, crystal structure and luminescence properties of one inorganic-organic hybrid compound [FTMA] 2[Co(NCS) 4] (FTMA = ferrocenylmethyltrimethylammonium cation)

    Science.gov (United States)

    Bai, Yan; Zhang, Guo-Qiang; Dang, Dong-Bin; Ma, Peng-Tao; Niu, Jing-Yang

    2011-08-01

    A new inorganic-organic hybrid compound [FTMA] 2[Co(NCS) 4] (FTMA = ferrocenylmethyltrimethylammonium cation) has been synthesized and characterized by IR, UV, elemental analysis and X-ray crystallography. Co(II) atom has a distorted tetrahedral environment with four N atoms of four NCS - anions. In the solid state there are C-H⋯π interactions between adjacent ferrocenyl cations, which generate one-dimensional (1-D) supramolecular chain, and C-H⋯S hydrogen bonds between [FTMA] + cations and cobalt thiocyanate anions. The title compound shows strong purple fluorescence emission in the solid state at room temperature.

  11. Spatial variation of salt-marsh organic and inorganic deposition and organic carbon accumulation: Inferences from the Venice lagoon, Italy

    Science.gov (United States)

    Roner, M.; D'Alpaos, A.; Ghinassi, M.; Marani, M.; Silvestri, S.; Franceschinis, E.; Realdon, N.

    2016-07-01

    inorganic soil content near the edge is due to the preferential deposition of inorganic sediment from the adjacent creek, and to the rapid decomposition of the relatively large biomass production. The higher organic matter content in the inner part of the marsh results from the small amounts of suspended sediment that makes it to the inner marsh, and to the low decomposition rate which more than compensates for the lower biomass productivity in the low-lying inner zones. Finally, the average soil organic carbon density from the LOI measurements is estimated to be 0.044 g C cm-3. The corresponding average carbon accumulation rate for the San Felice and Rigà salt marshes, 132 g C m-2 yr-1, highlights the considerable carbon stock and sequestration rate associated with coastal salt marshes.

  12. Reactions between sodium and various carbon bearing compounds

    International Nuclear Information System (INIS)

    The presence of carbon bearing materials in liquid sodium is undesirable because of their ability to carburise stainless steel components. It has been demonstrated for example that carbon taken up by stainless steels can affect their mechanical properties and that thinner sectioned material such as fuel cladding and the tubing of intermediate heat exchanger may be more sensitive to such effects. Generally speaking, there are a number of potential carbon sources in reactor systems. Some of the sources such as the graphite in neutron shield rods, boron carbide in control rods and carbide fuels are part of the reactor designs while others such as oil in mechanical pumps arid 'coupling-fluids' used to inspect plant components are associated with the respective operation arid inspection of the plant. In this paper it is intended to discuss in general terms the way these various compounds behave in liquid sodium and to assess what effect their presence will have on the materials of construction in fast reactor systems. The paper also reviews the chemistry of the environment in relation to the types of carburizing species which may exist in sodium systems

  13. Combining pH and electrical conductivity measurements to improve titrimetric methods to determine ammonia nitrogen, volatile fatty acids and inorganic carbon concentrations.

    Science.gov (United States)

    Charnier, C; Latrille, E; Lardon, L; Miroux, J; Steyer, J P

    2016-05-15

    Volatile fatty acids (VFA), inorganic carbon (IC) and total ammonia nitrogen (TAN) are key variables in the current context of anaerobic digestion (AD). Accurate measurements like gas chromatography and infrared spectrometry have been developed to follow the concentration of these compounds but none of these methods are affordable for small AD units. Only titration methods answer the need for small plant monitoring. The existing methods accuracy was assessed in this study and reveals a lack of accuracy and robustness to control AD plants. To solve these issues, a new titrimetric device to estimate the VFA, IC and TAN concentrations with an improved accuracy was developed. This device named SNAC (System of titration for total ammonia Nitrogen, volatile fatty Acids and inorganic Carbon) has been developed combining the measurement of electrical conductivity and pH. SNAC were tested on 24 different plant samples in a range of 0-0.16 mol.L(-1) TAN, 0.01-0.21 mol.L(-1) IC and 0-0.04 mol.L(-1) VFA. The standard error was about 0.012 mol.L(-1) TAN, 0.015 mol.L(-1) IC and 0.003 mol.L(-1) VFA. The coefficient of determination R(2) between the estimated and reference data was 0.95, 0.94 and 0.95 for TAN, IC and VFA respectively. Using the same data, current methods based on key pH points lead to standard error more than 14.5 times higher on VFA and more than 1.2 times higher on IC. These results show that SNAC is an accurate tool to improve the management of AD plant. PMID:27010787

  14. Dissolved inorganic carbon and pCO2 in two small streams draining different soil types in Southwestern Amazonia, Brazil

    OpenAIRE

    Eliete dos Santos Sousa, Cleber Ibraim Salimon, Reynaldo Luiz Victoria, Alex Vladimir Krusche, Simone Rebecca Alin, Nei Kavaguichi Leite

    2008-01-01

    The objective of this study was to determine the dissolved inorganic carbon (DIC) andpCO2 concentrations in two third order streams in southwestern Amazonia, Brazil. From May2004 to June 2005 water dissolved oxygen, pH, electrical conductivity, temperature weremeasured to stream water chemical and physical description. DIC and pCO2 measurementswere made by headspace extraction and gas samples for pCO2 and DIC extractions were runon an infrared gas analyzer (IRGA, LI-COR Instruments model LI-8...

  15. Dissolved inorganic carbon dynamics and CO2 atmospheric exchanges in the inner and outer Scheldt estuary

    OpenAIRE

    Borges, A. V.; Frankignoulle, M.

    2002-01-01

    Since 1992, the Chemical Oceanography Unit of the University of Liège has carried out on a regular basis field cruises in the Scheldt inner estuary and the river plume (outer estuary), during which were measured: pH, total alkalinity, dissolved inorganic carbon, partial pressure of CO2 (pCO2), dissolved oxygen and atmospheric flux of CO2. In the inner Scheldt estuary, pCO2 values in the upper estuary can be as high as 9000 ppm that is about 25 times the value of atmospheric equilibrium (pres...

  16. Preliminary Results from High Time-Resolution Measurements of Particulate Inorganic Ions and Black Carbon Downwind of Seoul, Korea

    Science.gov (United States)

    Ghim, Y.; Lee, Y.; Kim, C.; Choi, Y.; Lee, T.

    2011-12-01

    Concentrations of inorganic ions and black carbon (BC) in PM2.5 were measured using PILS (particle-into-liquid sampler, ADI 2081, Applikon) and MAAP (Multiangle Absorption Photometer, Model 5012, Thermo), respectively, at intervals of 20-30 minutes. The measurements were made at the Yongin campus of Hankuk University of Foreign Studies, about 35 km southeast of downtown Seoul, which is affected by prevailing northwesterlies. The site is considered as an ideal place for exploring transport of air pollutants and variations of secondary ion formation caused by photochemical reactions since there are no major emission sources nearby except a 4-lane road running about 1.4 km to the west. The concentration of BC has been continuously measured since July 2010. However, the concentrations of inorganic ions were measured intermittently since February 2011. In the measurements in February, nitrate accounted for about 39% of the total inorganic ion concentrations and showed the highest correlation coefficient of 0.93 with ammonium. The fraction of sulfate among inorganic ions was about 31%, and the correlation coefficient with ammonium was 0.85, lower than that of nitrate. As was in other rural areas in Korea, potassium was highly correlated with major secondary ions such as sulfate, nitrate and ammonium, whose correlation coefficients were 0.70-0.74. Total inorganic ion concentrations were highest at 09:30 local time (LT) on February 9 probably due to the effect of vehicle emissions during the morning rush hour, but the concentration of nitrate was the highest at 13:00 LT on February 17 because of secondary ion formation just before a full development of the convective boundary layer. BC concentrations during the measurement period in February were generally higher at midnight than in the daytime including rush hours. BC showed moderately higher correlations with secondary ions. The BC concentration from MAAP obtained by aerosol absorption coefficient divided by mass

  17. Hydrogenated 5-carbon compound and method of making

    Science.gov (United States)

    Elliott, Douglas C.; Frye, John G.

    1999-01-01

    The present invention is based upon the surprising discovery that a 5-carbon compound selected from the group of 4-oxopentanoic acid, at least one lactone of 4-oxopentanoic acid, and combinations thereof, may be hydrogenated with a bimetallic catalyst of a noble metal in combination with a second metal and preserve the pendant methyl group. It was further unexpectedly discovered that the same conditions of bimetallic catalyst in the presence of hydrogen are useful for catalyzing the different intermediate reactions for example angelicalactone to gamma-valerolactone and gamma-valerolactone to 1,4-pentanediol. Finally, it was surprising that levulinic acid could be converted to 2-methyltetrahydrofuran with heating in the presence of the bimetallic catalyst and hydrogen in a single process vessel. The method of the present invention unexpectedly produced a fuel or fuel component having 2-methyltetrahydrofuran either in a yield greater than 4.5 mol % or in combination with alcohols.

  18. Hydrogenated 5-carbon compound and method of making

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, D.C.; Frye, J.G.

    1999-03-16

    The present invention is based upon the surprising discovery that a 5-carbon compound selected from the group of 4-oxopentanoic acid, at least one lactone of 4-oxopentanoic acid, and combinations thereof, may be hydrogenated with a bimetallic catalyst of a noble metal in combination with a second metal and preserve the pendant methyl group. It was further unexpectedly discovered that the same conditions of bimetallic catalyst in the presence of hydrogen are useful for catalyzing the different intermediate reactions, for example, angelicalactone to gamma-valerolactone and gamma-valerolactone to 1,4-pentanediol. Finally, it was surprising that levulinic acid could be converted to 2-methyltetrahydrofuran with heating in the presence of the bimetallic catalyst and hydrogen in a single process vessel. The method of the present invention unexpectedly produced a fuel or fuel component having 2-methyltetrahydrofuran either in a yield greater than 4.5 mol % or in combination with alcohols. 8 figs.

  19. Microtrapping of volatile organic compounds with carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Chaudhery Mustansar Hussain

    2010-10-01

    Full Text Available Micro-sorbent traps referred to as microtraps serve as integrated concentration-injection devices for continuousmonitoring in gas phase streams. The application of carbon nanotubes as unique sorbents for the fabrication of microtrapsfor the nano-scale adsorption/desorption of volatile organic molecules is presented in this paper. The microtrap applicationrequires high adsorption capacity as well as easy desorbability; the latter being critical for injection mode of these integrateddevices. The micro-sorbent characteristics of single and multi-walled carbon nanotubes for gas phase adsorption/desorptionof several volatile organic compounds like DCM, ethanol and benzene etc. has been studied. The nonporous nature of carbonnanotubes (CNTs eliminates the mass transfer resistance related to diffusion into pore structures, thus allowing easydesorbability. At the same time, their high aspect ratios lead to large breakthrough volumes. As compared to a commercialsorbent carbopackTM, the breakthrough volume was as much as an order of magnitude higher in the CNTs, while the higherrate of desorption measured as the peak width at half height of the desorption band was found nearly eight times lower (i.e.,0.26 seconds with SWNT and 1.89 seconds with carbopackTM. The trapping and desorption characteristics of single andmulti walled nanotubes were found to be comparable. We also found that the presence of disordered carbon impurities,which could be removed by controlled oxidative annealing, could greatly degrade the performance of CNTs. This researchhas suggested that CNTs can be used in micro-sorbent traps and surprisingly enhance the efficiency of the integrated concentration-injection devices. Consequently, this will open the doors to the application of high-capacity, CNTs-based sorbentsas a better alternative to conventional sorbent in continuous monitoring devices.

  20. Root carbon input in organic and inorganic fertilizer-based systems

    DEFF Research Database (Denmark)

    Chirinda, Ngoni; Olesen, Jørgen E; Porter, John

    cropping systems in a long-term experiment in 2 years, 2008 and 2010. Sampled shoots and macro-roots of catch crop mixtures and cereals were characterized for dry matter (DM) biomass (C was estimated as 45 % of DM biomass). We also measured topsoil root-related soil respiration throughout the growing...... C input to remain scant. This study aimed at determining macro-root C input and topsoil root related respiration in response to nutrient management and soil fertility building measures. Methods We sampled roots and shoots of cereals and catch crops in inorganic and organic fertilizer-based arable...... season of winter wheat by subtracting soil respiration from soil with and without exclusion of roots. Results Catch crop roots accounted for more than 40 % of total plant C. For spring barley in 2008 and spring wheat in 2010, root C was higher in the organic than in the inorganic fertilizer-based systems...

  1. Global Distribution of Total Inorganic Carbon and Total Alkalinity below the Deepest Winter Mixed Layer Depths

    Energy Technology Data Exchange (ETDEWEB)

    Goyet, C.; Healy, R.; Ryan, J.; Kozyr, A.

    2000-05-01

    Modeling the global ocean-atmosphere carbon dioxide system is becoming increasingly important to greenhouse gas policy. These models require initialization with realistic three-dimensional (3-D) oceanic carbon fields. This report presents an approach to establishing these initial conditions from an extensive global database of ocean carbon dioxide (CO{sub 2}) system measurements and well-developed interpolation methods.

  2. Selection of pecan shell-based activated carbons for removal of organic and inorganic impurities from water.

    Science.gov (United States)

    Niandou, Mohamed A S; Novak, Jeffrey M; Bansode, Rishipal R; Yu, Jianmei; Rehrah, Djaafar; Ahmedna, Mohamed

    2013-01-01

    Activated carbons are a byproduct from pyrolysis and have value as a purifying agent. The effectiveness of activated carbons is dependent on feedstock selection and pyrolysis conditions that modify their surface properties. Therefore, pecan shell-based activated carbons (PSACs) were prepared by soaking shells in 50% (v/v) HPO or 25 to 50% of KOH-NaHCO followed by pyrolysis at 400 to 700°C under a N atmosphere. Physically activated PSACs were produced by pyrolysis at 700°C under N followed by activation with steam or CO at 700 to 900°C. Physicochemical, surface, and adsorption properties of the PSACs were compared with two commercially available activated carbons. The average mass yield of PSACs with respect to the initial mass of the biomass was about 20 and 34% for physically activated and chemically activated carbons, respectively. Acid-activated carbons exhibited higher surface area, higher bulk density, and lower ash content compared with steam- or CO-activated carbons and the two commercial products. Base activation led to the development of biochar with moderate to high surface area with surface charges suitable for adsorption of anionic species. Regardless of the activation method, PSACs had high total surface area ranging from 400 to 1000 m g, better pore size distribution, and more surface charges than commercial samples. Our results also showed that PSACs were effective in removing inorganic contaminants such as Cu and NO as well as organic contaminants such as atrazine and metolachlor. This study showed that pyrolysis conditions and activation had a large influence on the PSAC's surface characteristics, which can limit its effectiveness as a custom sorbent for targeted water contaminants. PMID:23673958

  3. Isotopic composition of dissolved inorganic carbon in subsurface sediments of gas hydrate-bearing mud volcanoes, Lake Baikal: implications for methane and carbonate origin

    OpenAIRE

    Krylov, A. A.; Khlystov, O.M.; Hachikubo, A.; Minami, H.; Nunokawa, Y.; Shoji, H; Zemskaya, T. I.; L. Naudts; Pogodaeva, T.V.; Kida, M; Kalmychkov, G. V.; J. Poort

    2010-01-01

    We report on the isotopic composition of dissolved inorganic carbon (DIC) in pore-water samples recovered by gravity coring from near-bottom sediments at gas hydrate-bearing mud volcanoes/gas flares (Malenky, Peschanka, Peschanka 2, Goloustnoe, and Irkutsk) in the Southern Basin of Lake Baikal. The d13C values of DIC become heavier with increasing subbottom depth, and vary between -9.5 and +21.4‰ PDB. Enrichment of DIC in 13C indicates active methane generation in anaerobic environments near ...

  4. Organic-inorganic compounds with strong nonlinear optical properties based on 2,4,6-trimethylpyridinium and tetrahedral BF4- networks

    Science.gov (United States)

    Wojtaś, Maciej; Bil, Andrzej; Jakubas, Ryszard; Gągor, Anna; Pietraszko, Adam; Czupiński, Olaf; Tylczyński, Zbigniew; Isakov, Dmitry

    2011-04-01

    A different organic-inorganic crystal—[2,4,6-trimethylpyridinium][BF4]—of nonlinear optical properties at room temperature was synthesized and characterized. The compound is built up of the organic [2,4,6-trimethylpyridinium] cations incorporated into inorganic, tetrahedral BF4 anions. It crystallizes at room temperature in the polar space group Pmn21, and undergoes three first-order phase transitions at [cooling (heating)] 241 (245) K, 297 (328) K, and 389 (406) K. The lowest temperature ferroic phase transition (ferroelastic; mm2→m type) is related to the significant pyroelectric effect. The compound was studied by single-crystal x-ray diffraction at several temperatures, using thermal (differential scanning calorimetry and thermogravimetric analysis) methods and dielectric spectroscopy. The piezoelectric, pyroelectric, and second-harmonic generation (SHG) properties were determined. Density-functional theory calculations in two stable phases are given. The [2,4,6-trimethylpyridinium][BF4] crystal exhibits a SHG efficiency of 1.7 times that of KDP. The mechanism of structural phase transitions in the title compound is discussed.

  5. The relative influence of topography and land cover on inorganic and organic carbon exports from catchments in southern Quebec, Canada

    Science.gov (United States)

    Li, Mingfeng; Giorgio, Paul A.; Parkes, Alice H.; Prairie, Yves T.

    2015-12-01

    Export of carbon (C) from watersheds represents a key component of local and regional C budgets. We explored the magnitude, variability, and drivers of inorganic, organic, and total C exports from 83 temperate catchments in southern Québec, Canada. The average dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), and total C (TC) exports from these catchments were 4.6, 5.1, and 10.2 g m-2 yr-1, respectively. Multiple regression models, using a combination of topographical variables (catchment area, shape, and slope), along with land cover variables (%vegetation, %wetland, %lake, and building density), explained 34%, 62%, and 53% of the variability in the DIC, DOC, and TC exports, respectively. Variance partitioning in the models revealed that topography is slightly more important than land cover in explaining the variance in DIC export (19% versus 15%), whereas land cover is much more important than topography in determining DOC export (44% versus 18%). Interestingly, %vegetation had a negative effect on DIC export but a positive effect on DOC export, suggesting that a change in land cover that reduces vegetation (e.g., deforestation) would lead to modest decreases in TC export but large increases in DIC/DOC export ratio. We conclude that topography and land cover together determine DIC, DOC, and TC exports. While topography is static, land cover can be altered, which will determine the quantity, form, and fate of C exported from these catchments. Finally, annual differences in export values that are related to temperature and precipitation suggest that climate change also have an impact on C export.

  6. Organic and Inorganic Carbon in the Rio Tinto (Spain) Deep Subsurface System: a Possible Model for Subsurface Carbon and Lithoautotrophs on Mars.

    Science.gov (United States)

    Bonaccorsi, R.; Stoker, C. R.; MARTE Science Team

    2007-12-01

    The subsurface is the key environment for searching for life on planets lacking surface life. Subsurface ecosystems are of great relevance to astrobiology including the search for past/present life on Mars. Conditions on the Martian surface do not support biological activity but the subsurface might preserve organics and host subsurface life [1]. A key requirement for the analysis of subsurface samples on Mars is the ability to characterize organic vs. inorganic carbon pools. This information is needed to determine if the sample contains organic material of biological origin and/ or to establish if pools of inorganic carbon can support subsurface biospheres. The Mars Analog Rio Tinto Experiment (MARTE) performed deep drilling of cores i.e., down to 165-m depth, in a volcanically-hosted-massive-sulfide deposit at Rio Tinto, Spain, which is considered an important analog of the Sinus Meridiani site on Mars. Results from MARTE suggest the existence of a relatively complex subsurface life including aerobic and anaerobic chemoautotrophs, and strict anaerobic methanogens sustained by Fe and S minerals in anoxic conditions, which is an ideal model analog for a deep subsurface Martian environment. We report here on the distribution of organic (C-org: 0.01-0.3Wt% and inorganic carbon (IC = 0.01-7.0 Wt%) in a subsurface rock system including weathered/oxidized i.e., gossan, and unaltered pyrite stockwork. Cores were analyzed from 3 boreholes (BH-4, BH-7, and BH-8) that penetrated down to a depth of ~165 m into massive sulfide. Nearsurface phyllosilicate rich-pockets contain the highest amounts of organics (0.3Wt%) [2], while the deeper rocks contain the highest amount of carbonates. Assessing the amount of C pools available throughout the RT subsurface brings key insight on the type of trophic system sustaining its microbial ecosystem (i.e., heterotrophs vs. autotrophs) and the biogeochemical relationships that characterize a new type of subsurface biosphere at RT. This

  7. Fabrication and Characterization of Inorganic Silver and Palladium Nanostructures within Hexagonal Cylindrical Channels of Mesoporous Carbon

    Directory of Open Access Journals (Sweden)

    Jheng-Guang Li

    2014-06-01

    Full Text Available In this study, we prepared a mesoporous carbon with hexagonally packed mesopores through evaporation-induced self-assembly (EISA—with the diblock copolymer poly(ethylene oxide-b-ε-caprolactone (PEO-b-PCL as the template (EO114CL84, phenolic resin as the carbon precursor, hexamethylenetetramine (HMTA as the curing agent, and star octakis-PEO-functionalized polyhedral oligomeric silsesquioxane (PEO–POSS as the structure modifier—and subsequent carbonization. We then took the cylindrical mesoporous carbon as a loading matrix, with AgNO3 and Pd(NO32 as metal precursors, to fabricate Ag nanowire/mesoporous carbon and Pd nanoparticle/mesoporous carbon nanocomposites, respectively, through an incipient wetness impregnation method and subsequent reduction under H2. We used transmission electron microscopy, electron diffraction, small-angle X-ray scattering, N2 isotherm sorption experiment, Raman spectroscopy, and power X-ray diffraction to investigate the textural properties of these nanometal/carbon nanocomposites. Most notably, the Raman spectra of the cylindrical mesoporous carbon, Ag/mesoporous carbon, and Pd/mesoporous carbon revealed interesting phenomena in terms of the ratios of the intensities of the D and G bands (ID/IG, the absolute scattering intensities, and the positions of the D bands.

  8. Fourier transform infrared spectroscopy, a new method for rapid determination of total organic and inorganic carbon and biogenic silica concentration in lake sediments

    DEFF Research Database (Denmark)

    Rosén, Peter; Vogel, Hendrik; Cunningham, Laura;

    2010-01-01

    We demonstrate the use of Fourier transform infrared spectroscopy (FTIRS) to make quantitative measures of total organic carbon (TOC), total inorganic carbon (TIC) and biogenic silica (BSi) concentrations in sediment. FTIRS is a fast and cost-effective technique and only small sediment samples are...... varied between r = 0.84-0.99 for TOC, r = 0.85-0.99 for TIC, and r = 0.68-0.94 for BSi. Because FTIR spectra contain information on a large number of both inorganic and organic components, there is great potential for FTIRS to become an important tool in paleolimnology....

  9. Atmospheric Mg2+ wet deposition within the continental United States and implications for soil inorganic carbon sequestration

    Science.gov (United States)

    Goddard, Megan A.; Mikhailova, Elena A.; Post, Christopher J.; Schlautman, Mark A.

    2007-02-01

    Little is known about atmospheric magnesium ion (Mg2+) wet deposition in relation to soil inorganic carbon sequestration. Understanding the conversion of carbon dioxide (CO2) or organic carbon to a form having a long residence time within the soil (e.g., dolomite, magnesian calcite) will greatly benefit agriculture, industry, and society on a global scale. This preliminary study was conducted to analyze atmospheric Mg2+ wet deposition within the continental United States (U.S.) and to rank the twelve major soil orders in terms of average annual atmospheric Mg2+ wet deposition. The total average annual Mg2+ wet deposition for each soil order was estimated with geographic information systems (GIS) using the following data layers: (1) atmospheric Mg2+ wet deposition data layers covering the continental U.S. for a 10-yr period (1994-2003) and (2) a soil order data layer derived from a national soils database. A map of average annual Mg2+ wet deposition for 1994-2003 reveals that the highest deposition (0.75-1.41 kg ha-1) occurred in Oregon, Washington, parts of California, and the coastal areas of East Coast states due to magnesium enrichment of atmospheric deposition from sea salt. The Midwestern region of the U.S. received about 0.25-0.75 kg ha-1 Mg2+ wet deposition annually, which was associated with loess derived soils, occurrence of dust storms and possibly fertilization. The soil orders receiving the highest average annual atmospheric Mg2+ wet deposition from 1994 to 2003 were: (1) Mollisols (3.7 × 107 kg), (2) Alfisols (3.6 × 107 kg) and (3) Ultisols (2.8 × 107 kg). In terms of potential soil carbon sequestration, the average annual atmospheric Mg2+ wet deposition was equivalent to formation of the following theoretical amounts of dolomite: (1) Mollisols (2.8 × 108 kg of CaMg(CO3)2), (2) Alfisols (2.7 × 108 kg of CaMg(CO3)2) and (3) Ultisols (2.1 × 108 kg of CaMg(CO3)2). The soil orders receiving the lowest average annual atmospheric Mg2+ wet deposition

  10. Atmospheric Mg2+ wet deposition within the continental United States and implications for soil inorganic carbon sequestration

    International Nuclear Information System (INIS)

    Little is known about atmospheric magnesium ion (Mg2+) wet deposition in relation to soil inorganic carbon sequestration. Understanding the conversion of carbon dioxide (CO2) or organic carbon to a form having a long residence time within the soil (e.g., dolomite, magnesian calcite) will greatly benefit agriculture, industry, and society on a global scale. This preliminary study was conducted to analyze atmospheric Mg2+ wet deposition within the continental United States (U.S.) and to rank the twelve major soil orders in terms of average annual atmospheric Mg2+ wet deposition. The total average annual Mg2+ wet deposition for each soil order was estimated with geographic information systems (GIS) using the following data layers: (1) atmospheric Mg2+ wet deposition data layers covering the continental U.S. for a 10-yr period (1994-2003) and (2) a soil order data layer derived from a national soils database. A map of average annual Mg2+ wet deposition for 1994-2003 reveals that the highest deposition (0.75-1.41 kg/ha) occurred in Oregon, Washington, parts of California, and the coastal areas of East Coast states due to magnesium enrichment of atmospheric deposition from sea salt. The Midwestern region of the U.S. received about 0.25-0.75 kg/ha Mg2+ wet deposition annually, which was associated with loess derived soils, occurrence of dust storms and possibly fertilization. The soil orders receiving the highest average annual atmospheric Mg2+ wet deposition from 1994 to 2003 were: (1) Mollisols (3.7 x 107 kg), (2) Alfisols (3.6 x 107 kg) and (3) Ultisols (2.8 x 107 kg). In terms of potential soil carbon sequestration, the average annual atmospheric Mg2+ wet deposition was equivalent to formation of the following theoretical amounts of dolomite: (1) Mollisols (2.8 x 108 kg of CaMg(CO3)2), (2) Alfisols (2.7 x 108 kg of CaMg(CO3)2) and (3) Ultisols (2.1 x 108 kg of CaMg(CO3)2). The soil orders receiving the lowest average annual atmospheric Mg2+ wet deposition were: (1

  11. Atmospheric Mg{sup 2+} wet deposition within the continental United States and implications for soil inorganic carbon sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Goddard, Megan A. [Google Earth, Mountain View, CA (United States); Mikhailova, Elena A.; Post, Christopher J. [Clemson Univ., SC (United States). Dept. of Forestry and Natural Resources; Schlautman, Mark A. [Clemson Univ., SC (United States). School of the Environment

    2007-02-15

    Little is known about atmospheric magnesium ion (Mg{sup 2+}) wet deposition in relation to soil inorganic carbon sequestration. Understanding the conversion of carbon dioxide (CO{sub 2}) or organic carbon to a form having a long residence time within the soil (e.g., dolomite, magnesian calcite) will greatly benefit agriculture, industry, and society on a global scale. This preliminary study was conducted to analyze atmospheric Mg{sup 2+} wet deposition within the continental United States (U.S.) and to rank the twelve major soil orders in terms of average annual atmospheric Mg{sup 2+} wet deposition. The total average annual Mg{sup 2+} wet deposition for each soil order was estimated with geographic information systems (GIS) using the following data layers: (1) atmospheric Mg{sup 2+} wet deposition data layers covering the continental U.S. for a 10-yr period (1994-2003) and (2) a soil order data layer derived from a national soils database. A map of average annual Mg{sup 2+} wet deposition for 1994-2003 reveals that the highest deposition (0.75-1.41 kg/ha) occurred in Oregon, Washington, parts of California, and the coastal areas of East Coast states due to magnesium enrichment of atmospheric deposition from sea salt. The Midwestern region of the U.S. received about 0.25-0.75 kg/ha Mg{sup 2+} wet deposition annually, which was associated with loess derived soils, occurrence of dust storms and possibly fertilization. The soil orders receiving the highest average annual atmospheric Mg{sup 2+} wet deposition from 1994 to 2003 were: (1) Mollisols (3.7 x 107 kg), (2) Alfisols (3.6 x 107 kg) and (3) Ultisols (2.8 x 107 kg). In terms of potential soil carbon sequestration, the average annual atmospheric Mg{sup 2+} wet deposition was equivalent to formation of the following theoretical amounts of dolomite: (1) Mollisols (2.8 x 108 kg of CaMg(CO3)2), (2) Alfisols (2.7 x 108 kg of CaMg(CO{sub 3}){sub 2}) and (3) Ultisols (2.1 x 108 kg of CaMg(CO3)2). The soil orders

  12. New Features on the Environmental Regulation of Metabolism Revealed by Modeling the Cellular Proteomic Adaptations Induced by Light, Carbon, and Inorganic Nitrogen in Chlamydomonas reinhardtii.

    Science.gov (United States)

    Gérin, Stéphanie; Leprince, Pierre; Sluse, Francis E; Franck, Fabrice; Mathy, Grégory

    2016-01-01

    Microalgae are currently emerging to be very promising organisms for the production of biofuels and high-added value compounds. Understanding the influence of environmental alterations on their metabolism is a crucial issue. Light, carbon and nitrogen availability have been reported to induce important metabolic adaptations. So far, the influence of these variables has essentially been studied while varying only one or two environmental factors at the same time. The goal of the present work was to model the cellular proteomic adaptations of the green microalga Chlamydomonas reinhardtii upon the simultaneous changes of light intensity, carbon concentrations (CO2 and acetate), and inorganic nitrogen concentrations (nitrate and ammonium) in the culture medium. Statistical design of experiments (DOE) enabled to define 32 culture conditions to be tested experimentally. Relative protein abundance was quantified by two dimensional differential in-gel electrophoresis (2D-DIGE). Additional assays for respiration, photosynthesis, and lipid and pigment concentrations were also carried out. A hierarchical clustering survey enabled to partition biological variables (proteins + assays) into eight co-regulated clusters. In most cases, the biological variables partitioned in the same cluster had already been reported to participate to common biological functions (acetate assimilation, bioenergetic processes, light harvesting, Calvin cycle, and protein metabolism). The environmental regulation within each cluster was further characterized by a series of multivariate methods including principal component analysis and multiple linear regressions. This metadata analysis enabled to highlight the existence of a clear regulatory pattern for every cluster and to mathematically simulate the effects of light, carbon, and nitrogen. The influence of these environmental variables on cellular metabolism is described in details and thoroughly discussed. This work provides an overview of the

  13. Seasonal variations in inorganic carbon components in the central and eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; DileepKumar, M.; George, M.D.; Rajendran, A.

    of carbon dioxide to atmosphere reached a maximum of approx 40 m mole m sup(-2) d sup(-1) around 16 degrees N in the central Arabian SEa during monsoon season. The carbon dioxide regenerated from soft tissue was higher during winter and is the least...

  14. Electrochemical study of oxidation process of promethazine using sensor based on carbon nanotubes paste containing immobilized DNA on inorganic matrix

    Directory of Open Access Journals (Sweden)

    João Paulo Marco

    2014-10-01

    Full Text Available In the present work the voltammetric behavior and the oxidation process of promethazine (PHZ in electrochemical sensor based on carbon nanotubes paste containing DNA immobilized on the inorganic matrix prepared by sol-gel process (SiO2/Al2O3/Nb2O5. The method of Laviron verified that the system is irreversible and high speed of electron transfer between the electrode and DNA. The study of the oxidation of PHZ and influence of pH showed slope of 0.054 V / pH (near the nernstian system: 0.0592 V / pH suggesting that it involves the transfer of two protons and two electrons.

  15. Carbon nanotubes noncovalently functionalized by an organic-inorganic hybrid: new building blocks for constructing superhydrophobic conductive coatings.

    Science.gov (United States)

    Peng, Mao; Qi, Ji; Zhou, Zhi; Liao, Zhangjie; Zhu, Zhongming; Guo, Honglei

    2010-08-17

    A facile method for constructing superhydrophobic, conductive, and transparent/translucent coatings is presented. Pristine multiwalled carbon nanotubes (MWNTs) are first noncovalently (wrapped) modified by an organic-inorganic hybrid of an amphiphilic copolymer of styrene and maleic anhydride and silica with the existence of gamma-aminopropyltriethoxysilane (a silane coupling agent). The modified MWNTs were mixed with tetraethyl orthosilicate in ethanol, air sprayed, coated with a fluoroalkylsilane, and then heat treated to obtain the superhydrophobic, conductive, and transparent/translucent coatings. Scanning electron microscopy shows that the coatings have a micrometer- and nanometer-scale hierarchical structure similar to that of lotus leaves; therefore, they show both high water contact angles (>160 degrees) and low sliding angles (coatings also exhibit good transmittance and greatly improved conductivities. This method is convenient, inexpensive, and easy to scale up. Moreover, it does not require any chemical modification of the MWNTs or use any harsh chemicals. PMID:20695543

  16. Temporal dynamics of groundwater-dissolved inorganic carbon beneath a drought-affected braided stream: Platte River case study

    Science.gov (United States)

    Boerner, Audrey R.; Gates, John B.

    2015-05-01

    Impacts of environmental changes on groundwater carbon cycling are poorly understood despite their potentially high relevance to terrestrial carbon budgets. This study focuses on streambed groundwater chemistry during a period of drought-induced river drying and consequent disconnection between surface water and groundwater. Shallow groundwater underlying vegetated and bare portions of a braided streambed in the Platte River (Nebraska, USA) was monitored during drought conditions in summer 2012. Water temperature and dissolved inorganic carbon (dominated by HCO3-) in streambed groundwater were correlated over a 3 month period coinciding with a decline in river discharge from 35 to 0 m3 s-1. Physical, chemical, and isotopic parameters were monitored to investigate mechanisms affecting the HCO3- trend. Equilibrium thermodynamic modeling suggests that an increase of pCO2 near the water table, coupled with carbonate mineral weathering, can explain the trend. Stronger temporal trends in Ca2+ and Mg2+ compared to Cl- are consistent with carbonate mineral reequilibria rather than evaporative concentration as the primary mechanism of the increased HCO3-. Stable isotope trends are not apparent, providing further evidence of thermodynamic controls rather than evaporation from the water table. A combination of increased temperature and O2 in the dewatered portion of the streambed is the most likely driver of increased pCO2 near the water table. Results of this study highlight potential linkages between surface environmental changes and groundwater chemistry and underscore the need for high-resolution chemical monitoring of alluvial groundwater in order to identify environmental change impacts.

  17. [Hydrochemical Characteristics and the Dissolved Inorganic Carbon Flux in Liuzhou Section of Liujiang Basin].

    Science.gov (United States)

    Yuan, Ya-qiong; He, Shi-yi; Yu, Shi; Sun, Ping-an; Wang, Yan-xue; Wu, Zhao-yun; Li, Xin-gui; Xie, Ming-xian; Liu, Wen; Li, Rui; Zhang, Hua-sheng

    2015-07-01

    An important aspect of the current global change research is using river chemical composition to reveal the chemical weathering process and its effect of carbon sink. In this study, water samples were collected and analyzed 2 ~3 times per month from January to December in 2013. The hydrochemistry belonged to HCO3-Ca type. Ca+ and HCO3- were the main cation and anion, which reflected that the hydrochemical characteristics of river were mainly affected by the dissolution of carbonate rock. The concentration of main ions varied with the seasons, which reflected that the crest value occurred in winter, followed by those in autumn and spring, and the lowest value was observed in summer. Due to the interaction of effect of dilution and effect of C2, the seasonal variation of Ca2+ and HCO3- showed that the highest value was in autumn and the lowest value was in summer. The seasonal variation law of other ions should be attributed to the effect of dilution or agricultural activities or combined action of them. Both carbonic acid and sulfuric acid took part in the chemical weathering of carbonate rocks as evidenced by stoichiometric analysis. Besides, the δ34S of sulfate ion of the river waters (δ34S: from 7. 65 per thousand to 8. 55 per thousand) showed that SO2- was originated mainly from oxidation of sulfide minerals in ore deposits and acid rain. Chemical mass balance method was applied to estimate the proportion of HCO- coming from carbonate weathering by sulfuric acid. The result was 28. 26% . On this basis, the total carbon flux of carbon ( by CO2 calculation) in Liuzhou section calculated month by month was about 8. 95 x 10(5) t . a-1. What's more, the carbon flux showed a positive correlation with flow, which implied that the discharge of catchment was the main influencing factor of carbon flux rather than the HCO3- concentration. PMID:26489309

  18. Isotope chromato-spectral determination of carbon monoxide in pure inorganic gases

    International Nuclear Information System (INIS)

    Application of isotope-chromato-spectral method for determination of carbon monoxide impurities in pure He, Ne, Ar, N2 and H2 is considered. Isotopic dilution of a sample of the gas under analysis is performed using carbon monoxide enriched by 13C with source relative isotope concentration 12C/13C=0.39. Limits of determining CO in gases by the method indicated make up nx(10-7-10-6) %

  19. Compound list: carbon tetrachloride [Open TG-GATEs

    Lifescience Database Archive (English)

    Full Text Available carbon tetrachloride CCL4 00003 ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Human/in_vitro/car...ates/LATEST/Rat/in_vitro/carbon_tetrachloride.Rat.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open...-tggates/LATEST/Rat/in_vivo/Liver/Single/carbon_tetrachloride.Rat.in_vivo.Liver.S...ingle.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Repeat/carbon_tetrachloride.Rat.in_vivo.Liver.Repeat.zip ...

  20. The effect of dimensionality of nanostructured carbon on the architecture of organic-inorganic hybrid materials.

    Science.gov (United States)

    Misra, R D K; Depan, D; Shah, J

    2013-08-21

    The natural tendency of carbon nanotubes (CNTs) to agglomerate is an underlying reason that prevents the realization of their full potential. On the other hand, covalent functionalization of CNTs to control dispersion leads to disruption of π-conjugation in CNTs and the non-covalent functionalization leads to a weak CNT-polymer interface. To overcome these challenges, we describe the characteristics of fostering of direct nucleation of polymers on nanostructured carbon (CNTs of diameters (~2-200 nm), carbon nanofibers (~200-300 nm), and graphene), which culminates in interfacial adhesion, resulting from electrostatic and van der Waals interaction in the hybrid nanostructured carbon-polymer architecture. Furthermore, the structure is tunable through a change in undercooling. High density polyethylene and polypropylene were selected as two model polymers and two sets of experiments were carried out. The first set of experiments was carried out using CNTs of diameter ~2-5 nm to explore the effect of undercooling and polymer concentration. The second set of experiments was focused on studying the effect of dimensionality on geometrical confinements. The periodic crystallization of polyethylene on small diameter CNTs is demonstrated to be a consequence of the geometrical confinement effect, rather than epitaxy, such that petal-like disks nucleate on large diameter CNTs, carbon nanofibers, and graphene. The application of the process is illustrated in terms of fabricating a system for cellular uptake and bioimaging. PMID:23817610

  1. Interactions of carbon nanotubes with aqueous/aquatic media containing organic/inorganic contaminants and selected organisms of aquatic ecosystems--A review.

    Science.gov (United States)

    Boncel, Sławomir; Kyzioł-Komosińska, Joanna; Krzyżewska, Iwona; Czupioł, Justyna

    2015-10-01

    Due to their unique molecular architecture translating into numerous every-day applications, carbon nanotubes (CNTs) will be ultimately an increasingly significant environmental contaminant. This work reviews qualitative/quantitative analyses of interactions of various types of CNTs and their chemically modified analogues with aqueous/aquatic media containing organic and inorganic contaminants and selected organisms of aquatic ecosystems. A special emphasis was placed on physicochemical interactions between CNTs as adsorbents of heavy metal cations and aromatic compounds (dyes) with its environmental consequences. The studies revealed CNTs as more powerful adsorbents of aromatic compounds (an order of magnitude higher adsorption capacity) than metal cations. Depending on the presence of natural organic matter (NOM) and/or co-contaminants, CNTs may act as Trojan horse while passing through biological membranes (in the absence of NOM coordinating metal ions). Nanotubes, depending on flow conditions and their morphology/surface chemistry, may travel with natural waters or sediment with immobilized PAHs or metals and/or increase cyto- and ecotoxicity of PAHs/metal ions by their release via competitive complexation, or cause synergic ecotoxicity while adsorbing nutrients. Additionally, toxicity of CNTs against exemplary aquatic microorganisms was reviewed. It was found for Daphnia magna that longer exposures to CNTs led to higher ecotoxicity with a prolonged CNTs excretion. SWCNTs were more toxic than MWCNTs, while hydrophilization of CNTs via oxidation or anchoring thereto polar/positively charged polymer chains enhanced stability of nanotubes dispersion in aqueous media. On the other hand, bioavailability of functionalized CNTs was improved leading to more complex both mechanisms of uptake and cytotoxic effects. PMID:26022284

  2. Beyond temperature: Clumped isotope signatures in dissolved inorganic carbon species and the influence of solution chemistry on carbonate mineral composition

    OpenAIRE

    Tripati, Aradhna K.; Hill, Pamela S.; Eagle, Robert A.; Mosenfelder, Jed L.; Tang, Jianwu; Schauble, Edwin A.; Eiler, John M.; Zeebe, Richard E.; Uchikawa, Joji; Coplen, Tyler B.; Ries, Justin B; Henry, Drew

    2015-01-01

    “Clumped-isotope” thermometry is an emerging tool to probe the temperature history of surface and subsurface environments based on measurements of the proportion of ^(13)C and ^(18)O isotopes bound to each other within carbonate minerals in ^(13)C^(18)O^(16)O_2^(2−) groups (heavy isotope “clumps”). Although most clumped isotope geothermometry implicitly presumes carbonate crystals have attained lattice equilibrium (i.e., thermodynamic equilibrium for a mineral, which is independent of solutio...

  3. Technical Note: Precise quantitative measurements of total dissolved inorganic carbon from small amounts of seawater using a gas chromatographic system

    Science.gov (United States)

    Hansen, T.; Gardeler, B.; Matthiessen, B.

    2013-10-01

    Total dissolved inorganic carbon (CT) is one of the most frequently measured parameters used to calculate the partial pressure of carbon dioxide in seawater. Its determination has become increasingly important because of the rising interest in the biological effects of ocean acidification. Coulometric and infrared detection methods are currently favored in order to precisely quantify CT. These methods however are not sufficiently validated for CT measurements of biological experiments manipulating seawater carbonate chemistry with an extended CT measurement range (~1250-2400 μmol kg-1) compared to natural open ocean seawater (~1950-2200 μmol kg-1). The requirement of total sample amounts between 0.1-1 L seawater in the coulometric- and infrared detection methods potentially exclude their use for experiments working with much smaller volumes. Additionally, precise CT analytics become difficult with high amounts of biomass (e.g., phytoplankton cultures) or even impossible in the presence of planktonic calcifiers without sample pre-filtration. Filtration however, can alter CT concentration through gas exchange induced by high pressure. Addressing these problems, we present precise quantification of CT using a small, basic and inexpensive gas chromatograph as a CT analyzer. Our technique is able to provide a repeatability of ±3.1 μmol kg-1, given by the pooled standard deviation over a CT range typically applied in acidification experiments. 200 μL of sample is required to perform the actual CT measurement. The total sample amount needed is 12 mL. Moreover, we show that sample filtration is applicable with only minor alteration of the CT. The method is simple, reliable and with low cumulative material costs. Hence, it is potentially attractive for all researchers experimentally manipulating the seawater carbonate system.

  4. Technical Note: Precise quantitative measurements of total dissolved inorganic carbon from small amounts of seawater using a gas chromatographic system

    Directory of Open Access Journals (Sweden)

    T. Hansen

    2013-10-01

    Full Text Available Total dissolved inorganic carbon (CT is one of the most frequently measured parameters used to calculate the partial pressure of carbon dioxide in seawater. Its determination has become increasingly important because of the rising interest in the biological effects of ocean acidification. Coulometric and infrared detection methods are currently favored in order to precisely quantify CT. These methods however are not sufficiently validated for CT measurements of biological experiments manipulating seawater carbonate chemistry with an extended CT measurement range (~1250–2400 μmol kg–1 compared to natural open ocean seawater (~1950–2200 μmol kg−1. The requirement of total sample amounts between 0.1–1 L seawater in the coulometric- and infrared detection methods potentially exclude their use for experiments working with much smaller volumes. Additionally, precise CT analytics become difficult with high amounts of biomass (e.g., phytoplankton cultures or even impossible in the presence of planktonic calcifiers without sample pre-filtration. Filtration however, can alter CT concentration through gas exchange induced by high pressure. Addressing these problems, we present precise quantification of CT using a small, basic and inexpensive gas chromatograph as a CT analyzer. Our technique is able to provide a repeatability of ±3.1 μmol kg−1, given by the pooled standard deviation over a CT range typically applied in acidification experiments. 200 μL of sample is required to perform the actual CT measurement. The total sample amount needed is 12 mL. Moreover, we show that sample filtration is applicable with only minor alteration of the CT. The method is simple, reliable and with low cumulative material costs. Hence, it is potentially attractive for all researchers experimentally manipulating the seawater carbonate system.

  5. Characterizing the metabolic trade-off in Nitrosomonas europaea in response to changes in inorganic carbon supply.

    Science.gov (United States)

    Jiang, D; Khunjar, W O; Wett, B; Murthy, S N; Chandran, K

    2015-02-17

    The link between the nitrogen and one-carbon cycles forms the metabolic basis for energy and biomass synthesis in autotrophic nitrifying organisms, which in turn are crucial players in engineered nitrogen removal processes. To understand how autotrophic nitrifying organisms respond to inorganic carbon (IC) conditions that could be encountered in engineered partially nitrifying systems, we investigated the response of one of the most extensively studied model ammonia oxidizing bacteria, Nitrosomonas europaea (ATCC19718), to three IC availability conditions: excess gaseous and excess ionic IC supply (40× stoichiometric requirement), excess gaseous IC supply (4× stoichiometric requirement in gaseous form only), and limiting IC supply (0.25× stoichiometric requirement). We found that, when switching from excess gaseous and excess ionic IC supply to excess gaseous IC supply, N. europaea chemostat cultures demonstrated an acclimation period that was characterized by transient decreases in the ammonia removal efficiency and transient peaks in the specific oxygen uptake rate. Limiting IC supply led to permanent reactor failures (characterized by biomass washout and failure of ammonia removal) that were preceded by similar decreases in the ammonia removal efficiency and peaks in the specific oxygen uptake rate. Notably, both excess gaseous IC supply and limiting IC supply elicited a previously undocumented increase in nitric and nitrous oxide emissions. Further, gene expression patterns suggested that excess gaseous IC supply and limiting IC supply led to consistent up-regulation of ammonia respiration genes and carbon assimilation genes. Under these conditions, interrogation of the N. europaea proteome revealed increased levels of carbon fixation and transport proteins and decreased levels of ammonia oxidation proteins (active in energy synthesis pathways). Together, the results indicated that N. europaea mobilized enhanced IC scavenging pathways for biosynthesis and

  6. Organic and inorganic compounds in the water streams of the paper machine; Haitta-ainevirrat ja -tasot paperikoneella - PMST 01

    Energy Technology Data Exchange (ETDEWEB)

    Tervonen, P.; Edelmann, K.; Kaijaluoto, S. [VTT Energy, Jyvaeskylae (Finland)

    1998-12-31

    The tightening standards for environmental protection set forth in legislation and the green consideration has reduced the environmental load of the paper and pulp industry significantly during recent years. Paper mills have decreased their water consumption by increasing internal circulation and by improving external effluent treatment. The consequence is that the concentrations of organic and inorganic dissolved and colloidal substances in the paper mill waters have risen. The fresh water consumption of paper machine can be decreased by cleaning the different water streams from the wire- and press-section and by lowering the amount of organic and inorganic materials led to paper machine water. In this case also water from mechanical pulping process and pulp itself should be cleaned. In this project the water use of modern paper machine and stream connections are studied. In addition flows, interactions and retention of dissolved and colloidal materials in the wet end of the paper machine are investigated. By utilizing this knowledge accurate simulation models of paper machine wet end can be created. With this model the various methods and technologies for controlling the harmful components in paper machine wet end are analyzed. (orig.)

  7. Expression of genes involved in the uptake of inorganic carbon in the gill of a deep-sea vesicomyid clam harboring intracellular thioautotrophic bacteria.

    Science.gov (United States)

    Hongo, Yuki; Ikuta, Tetsuro; Takaki, Yoshihiro; Shimamura, Shigeru; Shigenobu, Shuji; Maruyama, Tadashi; Yoshida, Takao

    2016-07-10

    Deep-sea vesicomyid clams, including the genus Phreagena (formerly Calyptogena), harbor thioautotrophic bacterial symbionts in the host symbiosome, which consists of cytoplasmic vacuoles in gill epithelial cells called bacteriocytes. The symbiont requires inorganic carbon (Ci), such as CO2, HCO3(-), and CO3(2-), to synthesize organic compounds, which are utilized by the host clam. The dominant Ci in seawater is HCO3(-), which is impermeable to cell membranes. Within the bacteriocyte, cytoplasmic carbonic anhydrase (CA) from the host, which catalyzes the inter-conversion between CO2 and HCO3(-), has been shown to be abundant and is thought to supply intracellular CO2 to symbionts in the symbiosome. However, the mechanism of Ci uptake by the host gill from seawater is poorly understood. To elucidate the influx pathway of Ci into the bacteriocyte, we isolated the genes related to Ci uptake via the pyrosequencing of cDNA from the gill of Phreagena okutanii, and investigated their expression patterns. Using phylogenetic and amino acid sequence analyses, three solute carrier family 4 (SLC4) bicarbonate transporters (slc4co1, slc4co2, and slc4co4) and two membrane-associated CAs (mcaco1 and mcaco2) were identified as candidate genes for Ci uptake. In an in situ hybridization analysis of gill sections, the expression of mcaco1 and mcaco2 was detected in the bacteriocytes and asymbiotic non-ciliated cells, respectively, and the expression of slc4co1 and slc4co2 was detected in the asymbiotic cells, including the intermediate cells of the inner area and the non-ciliated cells of the external area. Although subcellular localizations of the products of these genes have not been fully elucidated, they may play an important role in the uptake of Ci into the bacteriocytes. These findings will improve our understanding of the Ci transport system in the symbiotic relationships of chemosynthetic bivalves. PMID:27016297

  8. Use of inorganic and organic compounds as decontaminates for cobalt T-60 and cesium-134 by clover plant grown on Inshas Sandy soil

    International Nuclear Information System (INIS)

    Out door lysimeter experiment was carried out to elucidate the effect of four inorganic and three organic salts on 60 Co and 134 Cs uptake and dry matter yield of three cuts of clover in the soil Inshas A new concept was proposed for assessing the difference in capacity of soil to supply radionuclides (i.e. 60 Co and 134 Cs) to plants as affected by applied inorganic or organic compounds. The relation of plant tissues (Pc) Co/IR Cs content with increasing time can be expressed as log (Pc) = A + B log time (T), where A and B the regression. When the same plant species is grown on the same soil differ only in the applied compound (e.g. Fe-EDDHA, Fe-DTPA, Fe-O A C, Fe(Coo)z, A1(OH)3, Ca(H2 P O4)2 and Fe2 O3) the equation will change to, log (P'c) = A+ B' log (T) (I). Based on both equations, the relationship between (Pc) becomes; log (P'c) = [(A'B')/(AB + A B)[ +[1/A'B + A B)[ log (Pc) (II). The intercept (C) and slope (S) in Eq. (II) were determined among 7 treatments (for either 60 Co or 134 Cs). Then the difference of either Co or Cs accumulation with time between control and any other treatment was evaluated according to (C) and (S) values. The data also that Fe-DTPA is preferred for 60 Co as enhancing compound for plant uptake (for decontamination use); compared with other applied salts; on the other hand, any tested salts did not significantly effect 134 Cs taken by clover. Also, it was found that more than 70% of total cobalt uptake was accumulated in the roots which indicate that Co is less mobile in plants than Cs. 3 figs., 4 tabs

  9. Synergistic effects of dissolved organic carbon and inorganic nitrogen on methane uptake in forest soils without and with freezing treatment.

    Science.gov (United States)

    Wu, Haohao; Xu, Xingkai; Duan, Cuntao; Li, Tuansheng; Cheng, Weiguo

    2016-01-01

    There is limited knowledge about how the interaction of dissolved organic carbon (DOC) and inorganic nitrogen (N) released into the soil just after freezing can affect methane (CH4) uptake in forest soils. Here, we present how freezing treatment and glucose, as a DOC source, can affect the roles of NH4(+)-N and NO3(-)-N in inhibiting soil CH4 uptake, by using soil-core incubation experiments. A long-term freezing at low temperature reduced cumulative CH4 uptake in the soils sampled from two temperate forest stands without carbon (C) and N addition. The inhibition effects of N addition as NH4Cl and KNO3 on the soil CH4 uptake were much larger than C addition. Freezing treatment eliminated the inhibition effect of NH4Cl and KNO3 addition on CH4 uptake, and this response was affected by glucose addition and forest types. The addition of glucose eliminated the inhibition effect of NO3(-)-N on CH4 uptake in the forest soils without and with freezing treatment, while the addition of NH4(+)-N and glucose inhibited synergistically the soil CH4 uptake. The results highlight the importance of synergistic effects of DOC and N inputs on the soil CH4 uptake under forest stands during soil wetting and thawing periods. PMID:27572826

  10. Effect of inorganic carbon on the completely autotrophic nitrogen removal over nitrite (CANON) process in a sequencing batch biofilm reactor.

    Science.gov (United States)

    Chen, You-Peng; Li, Shan; Fang, Fang; Guo, Jin-Song; Zhang, Qiang; Gao, Xu

    2012-12-01

    Ammonia-oxidizing bacteria (AOB) and anaerobic ammonia-oxidizing bacteria (AnAOB) are autotrophic microorganisms. Inorganic carbon (IC) is their main carbon source. The effects of IC limitation on AOB and AnAOB in the completely autotrophic nitrogen removal over nitrite (CANON) process in a sequencing batch biofilm reactor (SBBR) were examined. The optimal IC concentration in the influent was investigated. The start-up time of the CANON process from the activated sludge in the SBBR was 80 d under controlled free ammonia (FA) conditions and sufficient IC source. The AOB and AnAOB activities were limited by an IC concentration of 50 mg-C-L(-1) in the influent, whilst the nitrogen loading rate (NLR) was 200 mg-N x L(-1) x d(-1). The experiment on recovering the influent IC showed that AOB and AnAOB activities were affected by the IC limitation, and not by the pH or FA, at 200mg-N x L(-1) x d(-1) NLR and 50mg-C x L(-1) IC in the CANON process. The activities were recovered by increasing the IC concentration in the influent. From an economic point of view, the optimal IC concentration in the influent was 250mg-C x L(-1) at 200mg-N x L(-1) x d(-1) NLR in this CANON system. PMID:23437661

  11. Efficient Charge Extraction and Slow Recombination in Organic-Inorganic Perovskites Capped with Semiconducting Single-Walled Carbon Nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Ihly, Rachelle; Dowgiallo, Anne-Marie; Yang, Mengjin; Schulz, Philip; Stanton, Noah J.; Reid, Obadiah G.; Ferguson, Andrew J.; Zhu, Kai; Berry, Joseph J.; Blackburn, Jeffrey L.

    2016-04-01

    Metal-halide based perovskite solar cells have rapidly emerged as a promising alternative to traditional inorganic and thin-film photovoltaics. Although charge transport layers are used on either side of perovskite absorber layers to extract photogenerated electrons and holes, the time scales for charge extraction and recombination are poorly understood. Ideal charge transport layers should facilitate large discrepancies between charge extraction and recombination rates. Here, we demonstrate that highly enriched semiconducting single-walled carbon nanotube (SWCNT) films enable rapid (sub-picosecond) hole extraction from a prototypical perovskite absorber layer and extremely slow back-transfer and recombination (hundreds of microseconds). The energetically narrow and distinct spectroscopic signatures for charges within these SWCNT thin films enables the unambiguous temporal tracking of each charge carrier with time-resolved spectroscopies covering many decades of time. The efficient hole extraction by the SWCNT layer also improves electron extraction by the compact titanium dioxide electron transport layer, which should reduce charge accumulation at each critical interface. Finally, we demonstrate that the use of thin interface layers of semiconducting single-walled carbon nanotubes between the perovskite absorber layer and a prototypical hole transport layer improves device efficiency and stability, and reduces hysteresis.

  12. Formation of "Chemically Pure" Magnetite from Mg-Fe-Carbonates Implications for the Exclusively Inorganic Origin of Magnetite and Sulfides in Martian Meteorite ALH84001

    Science.gov (United States)

    Golden, D. C.; Ming, Douglas W.; Lauer, H. V., Jr.; Morris, R. V.; Trieman, A. H.; McKay, G. A.

    2006-01-01

    Magnetite and sulfides in the black rims of carbonate globules in Martian meteorite ALH84001 have been studied extensively because of the claim by McKay et al. that they are biogenic in origin. However, exclusively inorganic (abiotic) processes are able to account for the occurrence of carbonate-sulfide-magnetite assemblages in the meteorite. We have previously precipitated chemically zoned and sulfide-bearing carbonate globules analogous to those in ALH84001 (at less than or equal to 150 C) from multiple fluxes of variable-composition Ca-Mg-Fe-CO2-S-H2O solutions. Brief heating of precipitated globules to approx. 470 C produced magnetite and pyrrhotite within the globules by thermal decomposition of siderite and pyrite, respectively. We have also shown that morphology of magnetite formed by inorganic thermal decomposition of Fe-rich carbonate is similar to the morphology of so-called biogenic magnetite in the carbonate globules of ALH84001. Magnetite crystals in the rims of carbonate globules in ALH84001 are chemically pure [Note: "Chemically pure" is defined here as magnetite with Mg at levels comparable or lower than Mg detected by [8] in ALH84001 magnetite]. A debate continues on whether or not chemically pure magnetite can form by the thermal decomposition of mixed Mg-Fe-carbonates that have formed under abiotic conditions. Thomas-Keprta et al. argue that it is not possible to form Mg-free magnetite from Mg-Fe-carbonate based on thermodynamic data. We previously suggested that chemically pure magnetite could form by the thermal decomposition of relatively pure siderite in the outer rims of the globules. Mg-Fe-carbonates may also thermally decompose under conditions conducive for formation of chemically pure magnetite. In this paper we show through laboratory experiments that chemically pure magnetite can form by an inorganic process from mixed Mg-Fe-carbonates.

  13. Synthesis of Carbon Nanotube-Inorganic Hybrid Nanocomposites: An Instructional Experiment in Nanomaterials Chemistry

    Science.gov (United States)

    de Dios, Miguel; Salgueirino, Veronica; Perez-Lorenzo, Moises; Correa-Duarte, Miguel A.

    2012-01-01

    An experiment is described to introduce advanced undergraduate students to an exciting area of nanotechnology that incorporates nanoparticles onto carbon nanotubes to produce systems that have valuable technological applications. The synthesis of such material has been easily achieved through a simple three-step procedure. Students explore…

  14. Optical Properties of Mixed Black Carbon, Inorganic and Secondary Organic Aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Paulson, S E

    2012-05-30

    Summarizes the achievements of the project, which are divided into four areas: 1) Optical properties of secondary organic aerosols; 2) Development and of a polar nephelometer to measure aerosol optical properties and theoretical approaches to several optical analysis problems, 3) Studies on the accuracy of measurements of absorbing carbon by several methods, and 4) Environmental impacts of biodiesel.

  15. Long-term effects of organic and inorganic nutrient sources on soil organic carbon and major nutrients in Vertisols

    Science.gov (United States)

    Aladakatti, Y. R.; Hallikeri, S. S.; Nandagavi, R. A.

    2012-04-01

    Field experiment conducted over 10 years at the University of Agricultural Sciences, Dharwad, India, assessed the long-term effects of various sources of organics (farmyard manure {FYM}, vermicompost and cotton crop residue) in conjunction with graded levels of inorganic fertilizers on the soil organic carbon (SOC), available major nutrients and seed cotton yield in cotton- (groundnut - winter Sorghum) rotation system. Main plots comprised FYM (10 Mg/ha), vermicompost (2.5 Mg/ha), cotton crop residue (2.5 Mg/ha) and combination of these organics in various proportions with an absolute control (no organics). No inorganic fertilizes, 50 and 100 % of the recommended dose of fertilizers (RDF) were assigned to the sub plots. The organics were applied every year during rainy season and the inorganic fertilizers as per the University recommended dose to each crop. Initial SOC, available N, P and K were 0.68%, 220, 22.5 and 403 kg/ha, respectively. Results indicated that at the end of tenth year of crop rotation, application of FYM, vermicompost and cotton crop residue either alone or in combination increased the SOC (0.68 to 0.81%), available N (220 to 308 kg/ha), P (22.5 to 33.0 kg/ha) and K (403 to 530 kg/ha) compared to the control plot where no organics were applied. SOC in the control treatment decreased to 0.52% at the end of tenth year from 0.68%. Averaged over five cropping cycles, application of FYM gave significantly higher yields of seed cotton, groundnut pods and sorghum grain over all other organic sources. During fifth cycle of cotton crop or 10th year of rotation, application of FYM along with 100% RDF resulted in the highest productivity and was similar to FYM + 50 % RDF, indicating a saving of 50% chemical fertilizer in these crops. Combination of cotton crop residue and vermicompost were next best alternative sources of organics after FYM in order of preference. Our studies suggest that in the scarcity of good quality manure such as FYM, cotton crop

  16. Inorganic carbon dynamics in the upwelling system off the Oregon coast and implications for commercial shellfish hatcheries

    Science.gov (United States)

    Vance, J. M.; Hales, B. R.

    2010-12-01

    The increasing absorption of anthropogenic CO2 by the global ocean and concomitant decrease in pH will alter seawater carbonate chemistry in ways that may negatively impact calcifying organisms. In particular, the change in saturation state (Ω) of calcium carbonate minerals calcite and aragonite may be energetically unfavorable for shell formation while favoring shell dissolution. Eastern boundary upwelling systems may provide insights into how ecosystems respond to future conditions of ocean acidification when deep water with high dissolved inorganic carbon (DIC), low pH and low Ω is forced toward the surface. Mortality in commercial seed stock and reduced wild set of the oyster Crassostrea gigas in the northeast Pacific during 2005-2009 reinforced the need for understanding biological responses to acidified ocean water. In response, a long-term strategy to understand local carbonate chemistry dynamics, seasonal perturbations and the effects on development of calcifying bivalves was developed. At present, a time-series of pCO2 measurements was implemented in April 2010 in Netarts Bay, Oregon at Whiskey Creek Shellfish Hatchery (WCH). The intake sits at a depth of 0.5-8ft and water is pumped in at 100gpm. A line taken off the intake is run continuously through a thermosalinograph at approximately 1.5gpm into a showerhead style equilibrator in which the headspace is recirculated by aerating the water for enhanced gas exchange. CO2 in equilibrated air is analyzed by NDIR. Additionally two discrete samples of intake seawater were taken across tidal cycles weekly and analyzed for total CO2 (TCO2) according to the methods of Hales et al. (2004) and pCO2 for quality control. The pCO2 in the bay exhibits a diurnal cycle representative of daytime photosynthesis and nighttime respiration. However, the phasing and profiles of these cycles are dominated by tidal mixing and are affected by the introduction of high pCO2 water during upwelling events. Diurnal pCO2 during

  17. Characteristics and source of inorganic and organic compounds in the sediments from two hydrothermal fields of the Central Indian and Mid-Atlantic Ridges

    Science.gov (United States)

    Peng, Xiaotong; Li, Jiwei; Zhou, Huaiyang; Wu, Zijun; Li, Jiangtao; Chen, Shun; Yao, Huiqiang

    2011-05-01

    A combined inorganic and organic geochemical study was carried out on sediments collected from the Kairei hydrothermal field on the Central Indian Ridge (CIR) and the Logatchev hydrothermal field on the Mid Atlantic Ridge (MAR). Analysis of the major and trace elements as well as the minerals shows that the Kairei hydrothermal sediments are formed by the mixing of silica-rich hydrothermal fluids with Mg-rich seawaters, but the Logatchev sediments are associated with pelagic carbonate oozes containing some precipitates derived from hydrothermal plume fall-out. The rare earth element (REE) patterns of Kairei sediments show a character of light REE (LREE) enrichment and positive Eu anomaly, whereas two of the three Logatchev sediment samples lack positive Eu anomaly and have negative Ce anomaly. Patterns of aliphatic hydrocarbon fractions in the sediments from both hydrothermal fields exhibit high relative concentrations of volatile resolved components, smooth n-alkane distributions and high concentrations of the isoprenoids pristane and phytane. The composition of organic matter and C isotope composition of individual n-alkanes indicate that they come from marine photosynthetic autotrophs and hydrothermal organisms, as well as terrestrial inputs in the Kairei and the Logatchev hydrothermal fields. Several parameters of organic geochemistry, used for assessing the maturity of bitumen, are well correlated with one another. In general, these parameters indicate that the Kairei sediments are more mature than the Logatchev sediments. The relationship between the inorganic parameters (REE/Fe and Eu/Eu ∗) and the organic parameter (bitumen maturity) might reflect changes of the hydrothermal influence on the sediments. The results of this study provide an insight into the variation of inorganic and organic geochemistry in deep-sea hydrothermal systems.

  18. Removal of inorganic mercury from aquatic environments by multi-walled carbon nanotubes

    OpenAIRE

    Yaghmaeian, Kamyar; Khosravi Mashizi, Reza; Nasseri, Simin; Mahvi, Amir Hossein; Alimohammadi, Mahmood; Nazmara, Shahrokh

    2015-01-01

    Background Mercury is considered as a toxic heavy metal in aquatic environments due to accumulation in bodies of living organisms. Exposure to mercury may lead to different toxic effects in humans including damages to kidneys and nervous system. Materials and methods Multi-walled carbon nanotubes (MWCNTs) were selected as sorbent to remove mercury from aqueous solution using batch technique. ICP instrument was used to determine the amount of mercury in solution. Moreover, pH, contact time and...

  19. Multidecadal accumulation of anthropogenic and remineralized dissolved inorganic carbon along the Extended Ellett Line in the northeast Atlantic Ocean

    Science.gov (United States)

    Humphreys, Matthew P.; Griffiths, Alex M.; Achterberg, Eric P.; Holliday, N. Penny; Rérolle, Victoire M. C.; Menzel Barraqueta, Jan-Lukas; Couldrey, Matthew P.; Oliver, Kevin I. C.; Hartman, Susan E.; Esposito, Mario; Boyce, Adrian J.

    2016-02-01

    Marine carbonate chemistry measurements have been carried out annually since 2009 during UK research cruises along the Extended Ellett Line (EEL), a hydrographic transect in the northeast Atlantic Ocean. The EEL intersects several water masses that are key to the global thermohaline circulation, and therefore the cruises sample a region in which it is critical to monitor secular physical and biogeochemical changes. We have combined results from these EEL cruises with existing quality-controlled observational data syntheses to produce a hydrographic time series for the EEL from 1981 to 2013. This reveals multidecadal increases in dissolved inorganic carbon (DIC) throughout the water column, with a near-surface maximum rate of 1.80 ± 0.45 µmol kg-1 yr-1. Anthropogenic CO2 accumulation was assessed, using simultaneous changes in apparent oxygen utilization (AOU) and total alkalinity (TA) as proxies for the biogeochemical processes that influence DIC. The stable carbon isotope composition of DIC (δ13CDIC) was also determined and used as an independent test of our method. We calculated a volume-integrated anthropogenic CO2 accumulation rate of 2.8 ± 0.4 mg C m-3 yr-1 along the EEL, which is about double the global mean. The anthropogenic CO2 component accounts for only 31 ± 6% of the total DIC increase. The remainder is derived from increased organic matter remineralization, which we attribute to the lateral redistribution of water masses that accompanies subpolar gyre contraction. Output from a general circulation ecosystem model demonstrates that spatiotemporal heterogeneity in the observations has not significantly biased our multidecadal rate of change calculations and indicates that the EEL observations have been tracking distal changes in the surrounding North Atlantic and Nordic Seas.

  20. Determination of organic compounds in medicinal plants, commercialized in capsulated forms and 'in natura' by wavelength dispersive X-ray fluorescence spectrometry (WDXRF). Determination of quantitative inorganic profiles

    International Nuclear Information System (INIS)

    X-ray fluorescence technique was used to determine major and trace elements for five Brazilian commercial medicinal plants. The bromobutane (Barbatimao), Ginkgo folium (Ginkgo biloba), Echinodorus macrophyllus (Chapeu de couro), Valeriana officinalis (Valeriana), Cordia salicifolia (Porangaba) samples were collected from three to six different commercial suppliers. The species were collected 'in natura' (leaves, flowers, barks and roots) and capsulated forms. The samples were grinded in liquid N2 atmosphere and double layer pressed pellet were prepared. The elements Na, Mg, P, S, Cl, K, Ca, Mn, Fe, Ni, Cu, Zn, Rb e Sr concentrations were determined by individual calibration curves. The precision and accuracy of method were evaluated by certified reference material, NIST 1547 - Peach Leaves and the Chauvenet, Cochrane, ANOVA and Z-score statistical tests were applied. Each specimen presented a distinct inorganic profile and a great variation in its composition was observed. The inorganic profile will contribute for the elaboration of a quality and security guide to assure the phytotherapics commercialization. Moreover, these profiles could be used as complementary data to active farmaco compounds profiles for specimen's ratification. (author)

  1. Tracing the Carbon Cycle in a Small Boreal Catchment of a Groundwater Dominated River Using the Isotopic Composition of Dissolved Inorganic Carbon

    Science.gov (United States)

    Niinikoski, P. I. A.; Karhu, J.

    2015-12-01

    Understanding the carbon cycle in river systems is particularly important in fragile catchments with agriculture, urbanization, water purification facilities and other possible contamination sources. The isotopic composition and concentration of dissolved inorganic carbon (DIC) has been used to determine carbon sinks and sources in river systems. The Vantaanjoki River, in southern Finland, is located in one of the most densely populated areas in Finland. Previous studies have shown the river having a considerable amount of groundwater - surface water interaction which leads to local groundwater being vulnerable to any contaminants released into the river. The catchment of the river has six water purification facilities, and during times of high discharge some of the waste water is released into the river without treatment. Other possible sources of contamination are urban areas, agriculture and a saw mill. In this study the isotopic composition of DIC was studied, along with the concentration of DIC in the river water, to determine the major influences in carbon balance in the river water, to see if human induced changes in the environment are affecting the carbon cycle. The highest δ13CDIC values were found in the summer, and the lowest ones in the spring. Locations of the water purification facilities or fields along the flow path did not show on the δ13CDIC values, nor in the DIC contents of the water. Similar trends in δ13CDIC values related to the variations between warm and cold seasons have been reported in other studies as well and are likely due to organic material forming and decaying in and around the river channel.

  2. Determination of carbon in uranium and its compounds

    International Nuclear Information System (INIS)

    This paper collects the analytical methods used our laboratories for the determination of carbon in uranium metal, uranate salts and the oxides, fluorides and carbides of uranium. The carbon is usually burned off in a induction or resistance oven under oxygen flow. The CO2 is collected in barite solution. Where it is backtitrated with potassium biphthalate. (Author)

  3. Methods for estimating the enthalpy of formation of inorganic compounds; thermochemical and crystallographic investigations of uranyl salts of group VI elements

    International Nuclear Information System (INIS)

    The first part of this thesis is concerned with parameter methods for estimating the standard enthalpy of formation, ΔH0sub(f), of inorganic compounds. In this type of method the estimate is a function of parameters, assigned to cation and anion, respectively. The usefulness of a new estimation method is illustrated in the case of uranyl sulphide. In the second part of this thesis crystallographic and thermochemical properties of uranyl salts of group VI elements are described. Crystal structures are given for β-UO2SO4, UO2SeO3, and α-UO2SeO4. Thermochemical measurements have been restricted to the determination of ΔH0sub(f)(UO2SO3) and ΔH0sub(f)(UO2TeO3) by means of isoperibol solution calorimetry. (Auth.)

  4. Carbon dioxide laser absorption spectra of toxic industrial compounds

    International Nuclear Information System (INIS)

    CO2 laser absorption cross-section data are reported for acrolein, styrene, ethyl acrylate, trichloroethylene, vinyl bromide, and vinylidene chloride. These data indicate that sub parts per billion level, interference-free detection limits should be possible for these compounds by the CO2 laser photoacoustic technique. Photoacoustic detectabilities below 40 ppb should be possible for these compounds in the presence of ambient air concentrations of water vapor and other anticipated interferences. These compounds are also found not to be important inerference in the detection of toxic hydrazine-based rocket fuels by CO2 laser spectroscopic techniques

  5. The use of capacitive deionization with carbon aerogel electrodes to remove inorganic contaminants from water

    International Nuclear Information System (INIS)

    The capacitive deionization of water with a stack of carbon aerogel electrodes has been successfully demonstrated for the first time. Unlike ion exchange, one of the more conventional deionization processes, no chemicals were required for regeneration of the system. Electricity was used instead. Water with various anions and cations was pumped through the electrochemical cell. After polarization, ions were electrostatically removed from the water and held in the electric double layers formed at electrode surfaces. The water leaving the cell was purified, as desired

  6. Differential monitoring of tritium and carbon-14 compounds

    International Nuclear Information System (INIS)

    A gaseous sampling system was developed to differentially collect all major volatile forms of tritium and carbon-14 according to chemical class. These chemical forms include: tritiated forms of water, hydrogen and organics; as well as 14C-containing carbon monoxide, carbon dioxide and organics. Sampling campaigns involving the use of this differential 3H and 14C collection system have been successfully conducted at a high level liquid waste solidification plant, at a spent fuel storage facility and in the vicinity of power reactors

  7. Bipolar mass spectrometry of labile coordination complexes, redox active inorganic compounds, and proteins using a glass nebulizer for sonic-spray ionization.

    Science.gov (United States)

    Antonakis, Manolis M; Tsirigotaki, Alexandra; Kanaki, Katerina; Milios, Constantinos J; Pergantis, Spiros A

    2013-08-01

    In this study, we report on the development of a novel nebulizer configuration for sonic-spray ionization (SSI) mass spectrometry (MS), more specifically for a version of SSI that is referred to as Venturi easy ambient sonic-spray ionization (V-EASI) MS. The developed nebulizer configuration is based on a commercially available pneumatic glass nebulizer that has been used extensively for aerosol formation in atomic spectrometry. In the present study, the nebulizer was modified in order to achieve efficient V-EASI-MS operation. Upon evaluating this system, it has been demonstrated that V-EASI-MS offers some distinct advantages for the analysis of coordination compounds and redox active inorganic compounds over the predominantly used electrospray ionization (ESI) technique. Such advantages, for this type of compounds, are demonstrated here for the first time. More specifically, a series of labile heptanuclear heterometallic [Cu(II) 6Ln(III)] clusters held together with artificial amino acid ligands, in addition to easily oxidized inorganic oxyanions of selenium and arsenic, were analyzed. The observed advantages pertain to V-EASI appearing to be a "milder" ionization source than ESI, not requiring electrical potentials for gas phase ion formation, thus eliminating the possibility of unwanted redox transformations, allowing for the "simultaneous" detection of negative and positive ions (bipolar analysis) without the need to change source ionization conditions, and also not requiring the use of syringes and delivery pumps. Because of such features, especially because of the absence of ionization potentials, EASI can be operated with minimal requirements for source parameter optimization. We observed that source temperature and accelerating voltage do not seem to affect labile compounds to the extent they do in ESI-MS. In addition, bipolar analysis of proteins was demonstrated here by acquiring both positive and negative ion mass spectra from the same protein solutions

  8. Mechanisms of Microwave Absorption in Carbon Compounds from Shungite

    OpenAIRE

    S. Emelyanov; A. Kuzmenko; V. Rodionov; M. Dobromyslov

    2013-01-01

    According to SEM, X-ray phase analysis, Raman scattering data features of nanostructural changes in shungite carbon structure were found when processing shungite in 52 % hydrofluoric acid. It is found that conductivity increases up to the values of electrical graphite and absorption of microwave radiation also increases at frequencies up to 40 GHz, which, along with dielectric losses, is due to intense processes of both scattering at laminar carbon structures and absorption of electromagnetic...

  9. Mechanisms of Microwave Absorption in Carbon Compounds from Shungite

    Directory of Open Access Journals (Sweden)

    S. Emelyanov

    2013-12-01

    Full Text Available According to SEM, X-ray phase analysis, Raman scattering data features of nanostructural changes in shungite carbon structure were found when processing shungite in 52 % hydrofluoric acid. It is found that conductivity increases up to the values of electrical graphite and absorption of microwave radiation also increases at frequencies up to 40 GHz, which, along with dielectric losses, is due to intense processes of both scattering at laminar carbon structures and absorption of electromagnetic energy.

  10. Development of inorganic and organic hybrid nanocoating based on carbon nanotubes for corrosion resistance.

    Science.gov (United States)

    Kang, T H; Bagkar, Nitin C; Jung, Y S; Chun, H H; Shin, S C; Cho, H; Kim, J K; Kim, T G

    2014-10-01

    In this study, we report the synthesis and characterization of novel hybrid nanocoating based on carbon nanotubes (CNTs) on anodized aluminum surfaces (AAO). The hybrid nanocoating was deposited by number of methods which include spray coating, spin coating and dip coating. The bonding of nanocoating with metal surface is an important parameter for successful modification of the metal surfaces. The improved adhesion of nanocoating on metal surfaces could be attributed to chemical bonding of sol-gel nanocoating with anodized surfaces. The nanocoated anodized aluminum surfaces showed superior adhesion and excellent anticorrosive properties. The nanocoated panels showed enhanced galvanic protection comparable to 80% of titanium metal as determined by galvanic corrosion measurements. It also showed higher thermal conductivities than stainless steel and bare anodized surfaces. PMID:25942874

  11. How significant is submarine groundwater discharge and its associated dissolved inorganic carbon in a river-dominated shelf system?

    Directory of Open Access Journals (Sweden)

    Q. Liu

    2012-05-01

    Full Text Available In order to assess the role of submarine groundwater discharge (SGD and its impact on the carbonate system on the northern South China Sea (NSCS shelf, we measured seawater concentrations of four radium isotopes 223,224,226,228Ra along with carbonate system parameters in June–July, 2008. Complementary groundwater sampling was conducted in coastal areas in December 2008 and October 2010 to constrain the groundwater end-members. The distribution of Ra isotopes in the NSCS was largely controlled by the Pearl River plume and coastal upwelling. Long-lived Ra isotopes (228Ra and 226Ra were enriched in the river plume but low in the offshore surface water and subsurface water/upwelling zone. In contrast, short-lived Ra isotopes (224Ra and 223Ra were elevated in the subsurface water/upwelling zone as well as in the river plume but depleted in the offshore surface water. In order to quantify SGD, we adopted two independent mathematical approaches. Using a three end-member mixing model with total alkalinity (TAlk and Ra isotopes, we derived a SGD flux into the NSCS shelf of 2.3–3.7 × 108 m3 day−1. Our second approach involved a simple mass balance of 228Ra and 226Ra and resulted in a first order but consistent SGD flux estimate of 2.2–3.7 × 108 m3 day−1. These fluxes were equivalent to 12–21 % of the Pearl River discharge, but the source of the SGD was mostly recirculated seawater. Despite the relatively small SGD volume flow compared to the river, the associated material fluxes were substantial given their elevated concentrations of dissolved inorganic solutes. In this case, dissolved inorganic carbon (DIC flux through SGD was 153–347 × 109 mol yr−1, or ~23–53 % of the riverine DIC export flux. Our estimates of the groundwater-derived phosphate flux ranged 3–68 × 10

  12. Dissolved inorganic carbon evolution and stable carbon isotope fractionation in acid mine drainage contaminated streams: Insights from a laboratory study

    International Nuclear Information System (INIS)

    Samples of groundwater, spring water and stream water contaminated by acid mine drainage (AMD), and uncontaminated stream water were collected and allowed to evolve in contact with air in the laboratory for 15-88 days. The objective of this study was to (1) document temporal changes in dissolved inorganic C (DIC) concentrations and stable isotopic composition (δ13CDIC) and (2) to determine the reaction mechanism and resulting isotopic fractionation (13C/12C) accompanying the chemical evolution of AMD. The contaminated spring and stream samples and one groundwater sample (with no HCO3-) showed temporal decreases in pH, Fe2+, alkalinity, and DIC, and enrichment in δ13CDIC. One contaminated groundwater sample (with HCO3- between 529 and 630 mg/L) showed a temporal increase in pH despite observed decreases in Fe2+, alkalinity and DIC, and enrichment in δ13CDIC. The uncontaminated stream samples showed a continuous temporal increase in pH, relatively constant alkalinity and DIC, and enrichment in δ13CDIC. The results suggest that proton production related to Fe2+ transformation is the driving force for DIC loss in AMD-contaminated samples, and that DIC loss can be described by first order kinetics. The C isotope enrichment rates associated with DIC loss in the contaminated samples varied between 1.0 per mille and 1.8 per mille for stream water, 2.1 per mille and 2.6 per mille for the spring, 1.0 per mille and 1.2 per mille for groundwater with no HCO3-, and 7.6 per mille and 9.3 per mille for groundwater with high HCO3-. Variations in 13C enrichment in the contaminated samples are attributed to differences in the initial Fe2+:HCO3- ratio. The effect of proton production on 13C enrichment in the AMD-contaminated samples was modeled as a Rayleigh-type distillation, whereby isotope fractionation was constant and occurred in an 'equilibrium closed system'. In the uncontaminated stream samples, C exchange between DIC and atmospheric CO2 resulted in an overall enrichment

  13. Hot reactions between tritium atoms and inorganic compounds (H2O,H2S,NH3)

    International Nuclear Information System (INIS)

    Hot atom chemical reactions of tritium from nuclear reactions 3He(n,p)T and 6Li(n,α)T or from an accelerator with H2O,D2O,H2S,NH3,ND3 are studied in gaseous and liquid phases. Hot reactive collisions produce mainly HT or DT and the synthesis of the initial tritiated compound HTO, DTO, HTS, NH2T or ND2T. In ND3 the analysis of the conjugated action of scavengers and moderators allows the determination of integral reactivity corresponding to the different hot reactions. Influence of gas pressure or gas-liquid transition is interpreted by the competition between monomolecular decomposition of tritiated compounds and their stabilization by intermolecular energy transfer. Slight isotopic effects measured show a compensation between chemical reactivity and moderating power of H2O and D2O or NH3 and ND3 molecules. 99 refs

  14. Highly reliable field electron emitters produced from reproducible damage-free carbon nanotube composite pastes with optimal inorganic fillers

    International Nuclear Information System (INIS)

    Highly reliable field electron emitters were developed using a formulation for reproducible damage-free carbon nanotube (CNT) composite pastes with optimal inorganic fillers and a ball-milling method. We carefully controlled the ball-milling sequence and time to avoid any damage to the CNTs, which incorporated fillers that were fully dispersed as paste constituents. The field electron emitters fabricated by printing the CNT pastes were found to exhibit almost perfect adhesion of the CNT emitters to the cathode, along with good uniformity and reproducibility. A high field enhancement factor of around 10 000 was achieved from the CNT field emitters developed. By selecting nano-sized metal alloys and oxides and using the same formulation sequence, we also developed reliable field emitters that could survive high-temperature post processing. These field emitters had high durability to post vacuum annealing at 950 °C, guaranteeing survival of the brazing process used in the sealing of field emission x-ray tubes. We evaluated the field emitters in a triode configuration in the harsh environment of a tiny vacuum-sealed vessel and observed very reliable operation for 30 h at a high current density of 350 mA cm−2. The CNT pastes and related field emitters that were developed could be usefully applied in reliable field emission devices. (paper)

  15. Carbon Nanomaterials Based Electrochemical Sensors/Biosensors for the Sensitive Detection of Pharmaceutical and Biological Compounds

    OpenAIRE

    Bal-Ram Adhikari; Maduraiveeran Govindhan; Aicheng Chen

    2015-01-01

    Electrochemical sensors and biosensors have attracted considerable attention for the sensitive detection of a variety of biological and pharmaceutical compounds. Since the discovery of carbon-based nanomaterials, including carbon nanotubes, C60 and graphene, they have garnered tremendous interest for their potential in the design of high-performance electrochemical sensor platforms due to their exceptional thermal, mechanical, electronic, and catalytic properties. Carbon nanomaterial-based el...

  16. Biodegradability of dissolved organic carbon in the Yukon River and its tributaries: Seasonality and importance of inorganic nitrogen

    Science.gov (United States)

    Wickland, Kimberly P.; Aiken, George R.; Butler, Kenna; Dornblaser, Mark M.; RGM Spencer; Striegl, Rob

    2012-01-01

    Northern high-latitude rivers transport large amounts of terrestrially derived dissolved organic matter (DOM) from boreal and arctic ecosystems to coastal areas and oceans. Current knowledge of the biodegradability of DOM in these rivers is limited, particularly for large rivers discharging to the Arctic Ocean. We conducted a seasonally comprehensive study of biodegradable dissolved organic carbon (BDOC) dynamics in the Yukon River and two of its tributaries in Alaska, USA. Distinct seasonal patterns of BDOC, consistent across a wide range of watershed size, indicate BDOC is transported year-round. Relative biodegradability (%BDOC) was greatest during winter, and decreased into spring and summer. Due to large seasonal differences in DOC concentration, the greatest concentrations of BDOC (mg C L−1) occurred during spring freshet, followed by winter and summer. While chemical composition of DOM was an important driver of BDOC, the overriding control of BDOC was mineral nutrient availability due to wide shifts in carbon (C) and nitrogen (N) stoichiometry across seasons. We calculated seasonal and annual loads of BDOC exported by the Yukon River by applying measured BDOC concentrations to daily water discharge values, and also by applying an empirical correlation between %BDOC and the ratio of DOC to dissolved inorganic N (DIN) to total DOC loads. The Yukon River exports ∼0.2 Tg C yr−1 as BDOC that is decomposable within 28 days. This corresponds to 12–18% of the total annual DOC export. Furthermore, we calculate that the six largest arctic rivers, including the Yukon River, collectively export ∼2.3 Tg C yr−1 as BDOC to the Arctic Ocean.

  17. N2O production by ammonia oxidizing bacteria in an enriched nitrifying sludge linearly depends on inorganic carbon concentration.

    Science.gov (United States)

    Peng, Lai; Ni, Bing-Jie; Ye, Liu; Yuan, Zhiguo

    2015-05-01

    The effect of inorganic carbon (IC) on nitrous oxide (N2O) production by ammonia oxidizing bacteria (AOB) was investigated over a concentration range of 0-12 mmol C/L, encompassing typical IC levels in a wastewater treatment reactors. The AOB culture was enriched along with nitrite-oxidizing bacteria (NOB) in a sequencing batch reactor (SBR) to perform complete nitrification. Batch experiments were conducted with continuous carbon dioxide (CO2) stripping or at controlled IC concentrations. The results revealed a linear relationship between N2O production rate (N2OR) and IC concentration (R(2) = 0.97) within the IC range studied, suggesting a substantial effect of IC on N2O production by AOB. Similar results were also obtained with an AOB culture treating anaerobic sludge digestion liquor. The fundamental mechanism responsible for this dependency is unclear; however, in agreement with previous studies, it was observed that the ammonia oxidation rate (AOR) was also influenced by the IC concentration, which could be well described by the Monod kinetics. These resulted in an exponential relationship between N2OR and AOR, as previously observed in experiments where AOR was altered by varying dissolved oxygen and ammonia concentrations. It is therefore possible that IC indirectly affected N2OR by causing a change in AOR. The observation in this study indicates that alkalinity (mostly contributed by IC) could be a significant factor influencing N2O production and should be taken into consideration in estimating and mitigating N2O emissions in wastewater treatment systems. PMID:25706224

  18. Pathways and transformations of dissolved methane and dissolved inorganic carbon in Arctic tundra watersheds: Evidence from analysis of stable isotopes

    Science.gov (United States)

    Throckmorton, Heather M.; Heikoop, Jeffrey M.; Newman, Brent D.; Altmann, Garrett L.; Conrad, Mark S.; Muss, Jordan D.; Perkins, George B.; Smith, Lydia J.; Torn, Margaret S.; Wullschleger, Stan D.; Wilson, Cathy J.

    2015-11-01

    Arctic soils contain a large pool of terrestrial C and are of interest due to their potential for releasing significant carbon dioxide (CO2) and methane (CH4) to the atmosphere. Due to substantial landscape heterogeneity, predicting ecosystem-scale CH4 and CO2 production is challenging. This study assessed dissolved inorganic carbon (DIC = Σ (total) dissolved CO2) and CH4 in watershed drainages in Barrow, Alaska as critical convergent zones of regional geochemistry, substrates, and nutrients. In July and September of 2013, surface waters and saturated subsurface pore waters were collected from 17 drainages. Based on simultaneous DIC and CH4 cycling, we synthesized isotopic and geochemical methods to develop a subsurface CH4 and DIC balance by estimating mechanisms of CH4 and DIC production and transport pathways and oxidation of subsurface CH4. We observed a shift from acetoclastic (July) toward hydrogenotropic (September) methanogenesis at sites located toward the end of major freshwater drainages, adjacent to salty estuarine waters, suggesting an interesting landscape-scale effect on CH4 production mechanism. The majority of subsurface CH4 was transported upward by plant-mediated transport and ebullition, predominantly bypassing the potential for CH4 oxidation. Thus, surprisingly, CH4 oxidation only consumed approximately 2.51 ± 0.82% (July) and 0.79 ± 0.79% (September) of CH4 produced at the frost table, contributing to <0.1% of DIC production. DIC was primarily produced from respiration, with iron and organic matter serving as likely e- acceptors. This work highlights the importance of spatial and temporal variability of CH4 production at the watershed scale and suggests broad scale investigations are required to build better regional or pan-Arctic representations of CH4 and CO2 production.

  19. Isotopic composition of dissolved inorganic carbon in subsurface sediments of gas hydrate-bearing mud volcanoes, Lake Baikal: implications for methane and carbonate origin

    Science.gov (United States)

    Krylov, Alexey A.; Khlystov, Oleg M.; Hachikubo, Akihiro; Minami, Hirotsugu; Nunokawa, Yutaka; Shoji, Hitoshi; Zemskaya, Tamara I.; Naudts, Lieven; Pogodaeva, Tatyana V.; Kida, Masato; Kalmychkov, Gennady V.; Poort, Jeffrey

    2010-06-01

    We report on the isotopic composition of dissolved inorganic carbon (DIC) in pore-water samples recovered by gravity coring from near-bottom sediments at gas hydrate-bearing mud volcanoes/gas flares (Malenky, Peschanka, Peschanka 2, Goloustnoe, and Irkutsk) in the Southern Basin of Lake Baikal. The δ13C values of DIC become heavier with increasing subbottom depth, and vary between -9.5 and +21.4‰ PDB. Enrichment of DIC in 13C indicates active methane generation in anaerobic environments near the lake bottom. These data confirm our previous assumption that crystallization of carbonates (siderites) in subsurface sediments is a result of methane generation. Types of methanogenesis (microbial methyl-type fermentation versus CO2-reduction) were revealed by determining the offset of δ13C between dissolved CH4 and CO2, and also by using δ13C and δD values of dissolved methane present in the pore waters. Results show that both mechanisms are most likely responsible for methane generation at the investigated locations.

  20. Enriched inorganic compounds in diesel exhaust particles induce mitogen-activated protein kinase activation, cytoskeleton instability, and cytotoxicity in human bronchial epithelial cells.

    Science.gov (United States)

    Seriani, Robson; Junqueira, Mara S; Carvalho-Sousa, Claudia E; Arruda, Alessandra C T; Martinez, Diana; Alencar, Adriano M; Garippo, Ana L; Brito, Jôse Mara; Martins, Milton A; Saldiva, Paulo H N; Negri, Elnara M; Mauad, Thais; Macchione, Mariangela

    2015-04-01

    This study assessed the effects of the diesel exhaust particles on ERK and JNK MAPKs activation, cell rheology (viscoelasticity), and cytotoxicity in bronchial epithelial airway cells (BEAS-2B). Crude DEP and DEP after extraction with hexane (DEP/HEX) were utilized. The partial reduction of some DEP/HEX organics increased the biodisponibility of many metallic elements. JNK and ERK were activated simultaneously by crude DEP with no alterations in viscoelasticity of the cells. Mitochondrial activity, however, revealed a decrease through the MTT assay. DEP/HEX treatment increased viscoelasticity and cytotoxicity (membrane damage), and also activated JNK. Our data suggest that the greater bioavailability of metals could be involved in JNK activation and, consequently, in the reduction of fiber coherence and increase in the viscoelasticity and cytotoxicity of BEAS cells. The adverse findings detected after exposure to crude DEP and to DEP/HEX reflect the toxic potential of diesel compounds. Considering the fact that the cells of the respiratory epithelium are the first line of defense between the body and the environment, our data contribute to a better understanding of the pathways leading to respiratory cell injury and provide evidence for the onset of or worsening of respiratory diseases caused by inorganic compounds present in DEP. PMID:25769681

  1. Estimation of transport parameters of phenolic compounds and inorganic contaminants through composite landfill liners using one-dimensional mass transport model

    International Nuclear Information System (INIS)

    Highlights: → We conduct 1D advection-dispersion modeling to estimate transport parameters. → We examine fourteen phenolic compounds and three inorganic contaminants. → 2-MP, 2,4-DCP, 2,6-DCP, 2,4,5-TCP, 2,3,4,6-TeCP have the highest coefficients. → Dispersion coefficients of Cu are determined to be higher than Zn and Fe. → Transport of phenolics can be prevented by zeolite and bentonite in landfill liners. - Abstract: One-dimensional (1D) advection-dispersion transport modeling was conducted as a conceptual approach for the estimation of the transport parameters of fourteen different phenolic compounds (phenol, 2-CP, 2-MP, 3-MP, 4-MP, 2-NP, 4-NP, 2,4-DNP, 2,4-DCP, 2,6-DCP, 2,4,5-TCP, 2,4,6-TCP, 2,3,4,6-TeCP, PCP) and three different inorganic contaminants (Cu, Zn, Fe) migrating downward through the several liner systems. Four identical pilot-scale landfill reactors (0.25 m3) with different composite liners (R1: 0.10 + 0.10 m of compacted clay liner (CCL), Le = 0.20 m, ke = 1 x 10-8 m/s, R2: 0.002-m-thick damaged high-density polyethylene (HDPE) geomembrane overlying 0.10 + 0.10 m of CCL, Le = 0.20 m, ke = 1 x 10-8 m/s, R3: 0.002-m-thick damaged HDPE geomembrane overlying a 0.02-m-thick bentonite layer encapsulated between 0.10 + 0.10 m CCL, Le = 0.22 m, ke = 1 x 10-8 m/s, R4: 0.002-m-thick damaged HDPE geomembrane overlying a 0.02-m-thick zeolite layer encapsulated between 0.10 + 0.10 m CCL, Le = 0.22 m, ke = 4.24 x 10-7 m/s) were simultaneously run for a period of about 540 days to investigate the nature of diffusive and advective transport of the selected organic and inorganic contaminants. The results of 1D transport model showed that the highest molecular diffusion coefficients, ranging from 4.77 x 10-10 to 10.67 x 10-10 m2/s, were estimated for phenol (R4), 2-MP (R1), 2,4-DNP (R2), 2,4-DCP (R1), 2,6-DCP (R2), 2,4,5-TCP (R2) and 2,3,4,6-TeCP (R1). For all reactors, dispersion coefficients of Cu, ranging from 3.47 x 10-6 m2/s to 5.37 x 10-2 m2/s, was

  2. Formation of inorganic nanofibers by heat-treatment of poly(vinyl alcohol-zirconium compound hybrid nanofibers

    Directory of Open Access Journals (Sweden)

    Nakane K.

    2013-01-01

    Full Text Available Poly(vinyl alcohol-zirconium compound hybrid nanofibers (precursors were formed by electrospinning employing water as a solvent for the spinning solution. The precursors were converted into oxide (ZrO2, carbide (ZrC or nitride (ZrN nanofibers by heating them in air, Ar or N2 atmospheres. Monoclinic ZrO2 nanofibers with high-specific surface area were obtained by heat-treatment of the precursors in air. ZrC and ZrN nanofibers could be obtained below theoretical temperatures calculated from thermodynamics data.

  3. APPLICATION OF AN INORGANIC ION EXCHANGER α—Zr(HPO4)2·H2O IN ELECTROREDUCTION OF CARBON MONOXIDE

    Institute of Scientific and Technical Information of China (English)

    HAOJinku; ZHAOWeijun; 等

    1993-01-01

    Gas phase reduction of carbon monoxide to formaldehyde and ethylene was found in electrochemical cell with an inorganic ion exchanger α-Zr(HPO4)2·H2O used as solid proton-conducting electrolyte at room temperature and atmospheric pressure.The type and amount of the electroreduction of CO depend on the different metal electrodes and current densities,which gives a lank between heterogeneous catalysis and electrochemistry.

  4. Importance of within-lake processes in affecting the dynamics of dissolved organic carbon and dissolved organic and inorganic nitrogen in an Adirondack forested lake/watershed

    OpenAIRE

    Kang, P.-G.; M. J. Mitchell; McHale, P J; Driscoll, C T; M. R. McHale; Inamdar, S.; Park, J.-H.

    2015-01-01

    Lakes nested in forested watersheds play important roles in mediating the concentrations and fluxes of dissolved organic matter. We compared long-term patterns of concentrations and fluxes of dissolved organic carbon (DOC), dissolved organic nitrogen (DON), and dissolved inorganic nitrogen (DIN) in the Arbutus Lake Watershed to evaluate how a lake nested in a forested watershed affects the dynamics of DOC and DON in the Adirondack Mountains of New York State...

  5. Dry and wet deposition of inorganic nitrogen compounds to a tropical pasture site (Rondônia, Brazil

    Directory of Open Access Journals (Sweden)

    I. Trebs

    2006-01-01

    Full Text Available The input of nitrogen (N to ecosystems has increased dramatically over the past decades. While total (wet + dry N deposition has been extensively determined in temperate regions, only very few data sets of N wet deposition exist for tropical ecosystems, and moreover, reliable experimental information about N dry deposition in tropical environments is lacking. In this study we estimate dry and wet deposition of inorganic N for a remote pasture site in the Amazon Basin based on in-situ measurements. The measurements covered the late dry (biomass burning season, a transition period and the onset of the wet season (clean conditions (12 September to 14 November 2002 and were a part of the LBA-SMOCC (Large-Scale Biosphere-Atmosphere Experiment in Amazonia – Smoke, Aerosols, Clouds, Rainfall, and Climate 2002 campaign. Ammonia (NH3, nitric acid (HNO3, nitrous acid (HONO, nitrogen dioxide (NO2, nitric oxide (NO, ozone (O3, aerosol ammonium (NH4+ and aerosol nitrate (NO3- were measured in real-time, accompanied by simultaneous meteorological measurements. Dry deposition fluxes of NO2 and HNO3 are inferred using the ''big leaf multiple resistance approach'' and particle deposition fluxes are derived using an established empirical parameterization. Bi-directional surface-atmosphere exchange fluxes of NH3 and HONO are estimated by applying a ''canopy compensation point model''. N dry and wet deposition is dominated by NH3 and NH4+, which is largely the consequence of biomass burning during the dry season. The grass surface appeared to have a strong potential for daytime NH3 emission, owing to high canopy compensation points, which are related to high surface temperatures and to direct NH3 emissions from cattle excreta. NO2 also significantly accounted for N dry deposition, whereas HNO3, HONO and N-containing aerosol species were only minor contributors. Ignoring NH3 emission from the vegetation surface, the annual net N deposition rate is estimated to

  6. Dry and wet deposition of inorganic nitrogen compounds to a tropical pasture site (Rondônia, Brazil

    Directory of Open Access Journals (Sweden)

    M. O. Andreae

    2005-05-01

    Full Text Available The input of nitrogen (N to ecosystems has increased dramatically over the past decades. While total N deposition (wet + dry has been extensively determined in temperate regions, only very few data sets exist about wet N deposition in tropical ecosystems, and moreover, experimental information about dry N deposition in tropical environments is lacking. In this study we estimate dry and wet deposition of inorganic N for a remote pasture site in the Amazon Basin based on in-situ measurements. The measurements covered the late dry (biomass burning season, a transition period and the onset of the wet season (clean conditions (12 September to 14 November 2002, LBA-SMOCC. Ammonia (NH3, nitric acid (HNO3, nitrous acid (HONO, nitrogen dioxide (NO2, nitric oxide (NO, ozone (O3, aerosol ammonium (NH4+ and aerosol nitrate (NO3- were measured in real-time, accompanied by simultaneous (micro-meteorological measurements. Dry deposition fluxes of NO2 and HNO3 are inferred using the ''big leaf multiple resistance approach'' and particle deposition fluxes are derived using an established empirical parameterization. Bi-directional surface-atmosphere exchange fluxes of NH3 and HONO are estimated by applying a ''canopy compensation point model''. Dry and wet N deposition is dominated by NH3 and NH4+, which is largely the consequence of biomass burning during the dry season. The grass surface appeared to have a strong potential for daytime NH3 (re-emission, owing to high canopy compensation points, which are related to high surface temperatures and to direct NH3 emissions from cattle excreta. NO2 also significantly accounted for dry N deposition, whereas HNO3, HONO and N-containing aerosol species were only minor contributors. We estimated a total (dry + wet N deposition of 7.3–9.8 kgN ha-1 yr-1 to the tropical pasture site, whereof 2–4.5 kgN ha-1 yr-1 are attributed to dry N deposition and ~5.3 kgN ha-1 yr-1 to wet N deposition. Our estimate exceeds total

  7. Dry and wet deposition of inorganic nitrogen compounds to a tropical pasture site (Rondônia, Brazil)

    Science.gov (United States)

    Trebs, I.; Lara, L. L.; Zeri, L. M. M.; Gatti, L. V.; Artaxo, P.; Dlugi, R.; Slanina, J.; Andreae, M. O.; Meixner, F. X.

    2006-02-01

    The input of nitrogen (N) to ecosystems has increased dramatically over the past decades. While total (wet + dry) N deposition has been extensively determined in temperate regions, only very few data sets of N wet deposition exist for tropical ecosystems, and moreover, reliable experimental information about N dry deposition in tropical environments is lacking. In this study we estimate dry and wet deposition of inorganic N for a remote pasture site in the Amazon Basin based on in-situ measurements. The measurements covered the late dry (biomass burning) season, a transition period and the onset of the wet season (clean conditions) (12 September to 14 November 2002) and were a part of the LBA-SMOCC (Large-Scale Biosphere-Atmosphere Experiment in Amazonia - Smoke, Aerosols, Clouds, Rainfall, and Climate) 2002 campaign. Ammonia (NH3), nitric acid (HNO3), nitrous acid (HONO), nitrogen dioxide (NO2), nitric oxide (NO), ozone (O3), aerosol ammonium (NH4+) and aerosol nitrate (NO3-) were measured in real-time, accompanied by simultaneous meteorological measurements. Dry deposition fluxes of NO2 and HNO3 are inferred using the ''big leaf multiple resistance approach'' and particle deposition fluxes are derived using an established empirical parameterization. Bi-directional surface-atmosphere exchange fluxes of NH3 and HONO are estimated by applying a ''canopy compensation point model''. N dry and wet deposition is dominated by NH3 and NH4+, which is largely the consequence of biomass burning during the dry season. The grass surface appeared to have a strong potential for daytime NH3 emission, owing to high canopy compensation points, which are related to high surface temperatures and to direct NH3 emissions from cattle excreta. NO2 also significantly accounted for N dry deposition, whereas HNO3, HONO and N-containing aerosol species were only minor contributors. Ignoring NH3 emission from the vegetation surface, the annual net N deposition rate is estimated to be about

  8. Dry and wet deposition of inorganic nitrogen compounds to a tropical pasture site (Rondónia, Brazil)

    Science.gov (United States)

    Trebs, I.; Lara, L. L.; Zeri, L. M. M.; Gatti, L. V.; Artaxo, P.; Dlugi, R.; Slanina, J.; Andreae, M. O.; Meixner, F. X.

    2005-05-01

    The input of nitrogen (N) to ecosystems has increased dramatically over the past decades. While total N deposition (wet + dry) has been extensively determined in temperate regions, only very few data sets exist about wet N deposition in tropical ecosystems, and moreover, experimental information about dry N deposition in tropical environments is lacking. In this study we estimate dry and wet deposition of inorganic N for a remote pasture site in the Amazon Basin based on in-situ measurements. The measurements covered the late dry (biomass burning) season, a transition period and the onset of the wet season (clean conditions) (12 September to 14 November 2002, LBA-SMOCC). Ammonia (NH3), nitric acid (HNO3), nitrous acid (HONO), nitrogen dioxide (NO2), nitric oxide (NO), ozone (O3), aerosol ammonium (NH4+) and aerosol nitrate (NO3-) were measured in real-time, accompanied by simultaneous (micro-)meteorological measurements. Dry deposition fluxes of NO2 and HNO3 are inferred using the ''big leaf multiple resistance approach'' and particle deposition fluxes are derived using an established empirical parameterization. Bi-directional surface-atmosphere exchange fluxes of NH3 and HONO are estimated by applying a ''canopy compensation point model''. Dry and wet N deposition is dominated by NH3 and NH4+, which is largely the consequence of biomass burning during the dry season. The grass surface appeared to have a strong potential for daytime NH3 (re-)emission, owing to high canopy compensation points, which are related to high surface temperatures and to direct NH3 emissions from cattle excreta. NO2 also significantly accounted for dry N deposition, whereas HNO3, HONO and N-containing aerosol species were only minor contributors. We estimated a total (dry + wet) N deposition of 7.3-9.8 kgN ha-1 yr-1 to the tropical pasture site, whereof 2-4.5 kgN ha-1 yr-1 are attributed to dry N deposition and ~5.3 kgN ha-1 yr-1 to wet N deposition. Our estimate exceeds total (wet + dry) N

  9. Photochemical Production of Dissolved Inorganic Carbon from Oceanic Colored Dissolved Organic Matter: a Gentle Approach to Measuring a new "Wild Card" Carbon Cycle Term

    Science.gov (United States)

    Zafiriou, O. C.; Wang, W.; Johnson, C. G.

    2004-12-01

    BACKGROUND: Massive oceanic photochemical remineralization (termed "photo-CO2") has been reported[1-3]: CDOM + hv -----> CO2 (DIC) CDOM = Colored Dissolved Organic Matter. DIC = Dissolved Inorganic Carbon. The oceanic carbon cycle cannot be understood without quantifying photo-CO2 fluxes and their sensitivity to environmental variables. The optical model of Johannessen implies a global marine photo-CO2 of ˜1015 mol C or 12 Gt C a-1[4]; Kieber and Mopper find photo-CO2 formation rates in the NW Sargasso Sea of ˜20 nmol kg-1 hr-1, extrapolating to ˜1.3 Gt C a-1[5-7; D. Kieber pers. comm, 2003]. CURRENT METHOD: To achieve essential sensitivity, Antonio, TX). 2. Johannessen, S., L. Ziolkowski and W. Miller (2000). (Abstracts of Pacifichem 2000, Vol. 1, ENVR-332). 3. Miller, W.L. and S.C. Johannessen (1999). Eos, Trans. Am. Geophys. Un., 80:0S93, Abstract 0521K-09 (2000 AGU-ASLO Ocean Sciences Meeting, January 24-28, 2000. 4. Johannessen, S. C.H. A photochemical sink for dissolved organic carbon in the ocean. Ph.D Thesis, Dalhousie University, CA. 179pp May, 2000. 5. Kieber, D. J., K. Mopper and J.G. Qian (1999). Trans. Am. Geophys. Un. 80: OS 128, Abstract #0522J-01 6. Kieber, D., K. Mopper and J. Qian (2000). Abstracts of Pacifichem 2000, Vol. 1, ENVR-28). 7. Kieber, D.J., K. Mopper, J. Qian and O.C. Zafiriou 8. Zeebe, R.E., D.B. Wolf-Gladrow and H. Jansen (1999). Mar.Chem. 65, 135-153. 9. Nelson, N.B, D. A. Siegel, and A.F. Michaels (1998) Deep-Sea Res. 45, 931-957.

  10. Continuous flow pyrolysis techniques for the isotopic measurements of oxygen-deuterium in waters, organic and inorganic compounds

    International Nuclear Information System (INIS)

    The technique of interfacing an elemental analyser (EA) with a stable isotope ratio mass spectrometer has, since its inception in 1983, proven to be a remarkably versatile analytical tool for the measurement of carbon and nitrogen isotopes across a wide application base. By 1994, sulphur isotopes had been added to the list and, more recently, those of oxygen and hydrogen. The analysis of oxygen and hydrogen involved a departure from the normal flash-combustion mode of operation to one of pyrolytic thermal decomposition of the sample. This paper describes a new EA technique for the measurement of hydrogen isotopes in water, in a continuous-flow carrier stream of helium. The system is totally carbon free and is based on the use of chromium (patented) as the active reactor material. Water injected into this system is reduced, resulting in the quantitative release of hydrogen gas, which is then carried by the helium to the mass spectrometer and analysed for deuterium concentration. This technique exhibits remarkably low memory effects, excellent precision and accuracy, and addresses sample sizes down to 50 nL. In addition, it allows a very high sample throughput with individual sample analysis time of 3 min

  11. Synthesis of Carbon Nanotubes and Volatile Organic Compounds Detection

    OpenAIRE

    Sobri S.; Jasni J.; Yasin Faizah M.; Jamal Siti Hasnawati; Janudin Nurjahirah; Mohd Kasim Noor Azilah

    2016-01-01

    In this work, the adsorption effect of volatile organic compounds (chloroacetophenone, acetonitrile and hexane) towards the change of resistance of CNTs pellet as sensor signal was investigated. CNTs used in this research were synthesized using Floating Catalyst – Chemical Vapor Deposition (FC-CVD) method in optimum condition. The synthesized CNTs were characterized using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Raman Spectroscopy. The variation of resist...

  12. Microtrapping of volatile organic compounds with carbon nanotubes

    OpenAIRE

    Chaudhery Mustansar Hussain; Chutarat Saridara; Somenath Mitra

    2010-01-01

    Micro-sorbent traps referred to as microtraps serve as integrated concentration-injection devices for continuousmonitoring in gas phase streams. The application of carbon nanotubes as unique sorbents for the fabrication of microtrapsfor the nano-scale adsorption/desorption of volatile organic molecules is presented in this paper. The microtrap applicationrequires high adsorption capacity as well as easy desorbability; the latter being critical for injection mode of these integrateddevices. Th...

  13. Transformation and utilization of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Bhanage, Bhalchandra M. [Institute of Chemical Technology, Mumbai (India). Dept. of Chemistry; Arai, Masahiko (ed.) [Hokkaido Univ., Sapporo (Japan). Division of Chemical Process Engineering

    2014-04-01

    This book shows the various organic, polymeric and inorganic compounds which result from the transformation of carbon dioxide through chemical, photocatalytic, electrochemical, inorganic and biological processes. The book consists of twelve chapters demonstrating interesting examples of these reactions, depending on the types of reaction and catalyst. It also includes two chapters dealing with the utilization of carbon dioxide as a reaction promoter and presents a wide range of examples of chemistry and chemical engineering with carbon dioxide.

  14. Trends in air concentration and deposition at background monitoring sites in Sweden - major inorganic compounds, heavy metals and ozone

    Energy Technology Data Exchange (ETDEWEB)

    Kindbom, K.; Svensson, Annika; Sjoeberg, K.; Pihl Karlsson, G.

    2001-09-01

    This report describes concentrations in air of sulphur compounds, soot, nitrogen compounds and ozone in Sweden between 1985-1998. Time trends of concentration in precipitation and deposition of sulphate, nitrate, ammonium, acidity, base cations and chloride in six different regions covering Sweden are evaluated during the period 1983-1998. Trends of heavy metals in precipitation have been analysed for the period 1983-1998 and the change in heavy metal concentration, 1975-1995, in mosses is described. Data used in the trend analyses originates from measurements performed at six Swedish EMEP stations and from approximately 25 stations within the national Precipitation Chemistry Network. Two different statistical methods, linear regression and the non-parametric Mann Kendall test, have been used to evaluate changes in annual mean values. Time trends of concentration of sulphur dioxide, particulate sulphate, soot, nitrogen dioxide, total nitrate and total ammonium in air show highly significant decreasing trends, except for soot at one station in northern Sweden. Concentrations of ozone have a strong seasonal variation with a peak occurring in spring every year. However, annual ozone concentrations show no obvious trends in spite of decreasing emissions of the precursors NOx and VOC. A slight indication of a decreasing trend in the number of ozone episodes might be seen from 1990 to 1998. Sulphate concentrations in precipitation and deposition show strongly significant decreasing trends in the whole country. Concentrations and deposition of nitrate and ammonium have been decreasing in all areas except for nitrate at stations in south-west and north-west Sweden and ammonium in south-west Sweden. Acidity has decreased in all areas since 1989, resulting in increasing pH values in Sweden. The interannual variations of concentration and deposition of base cations and chloride are large and few general trends can be seen during 1983-1997. Time trends of four heavy metals in

  15. Carbonic anhydrases are producers of S-nitrosothiols from inorganic nitrite and modulators of soluble guanylyl cyclase in human platelets.

    Science.gov (United States)

    Hanff, Erik; Böhmer, Anke; Zinke, Maximilian; Gambaryan, Stepan; Schwarz, Alexandra; Supuran, Claudiu T; Tsikas, Dimitrios

    2016-07-01

    Nitric oxide (NO), S-nitrosoglutathione (GSNO) and S-nitrosocysteine are highly potent signaling molecules, acting both by cGMP-dependent and cGMP-independent mechanisms. The NO metabolite nitrite (NO2 (-)) is a major NO reservoir. Hemoglobin, xanthine oxidoreductase and carbonic anhydrase (CA) have been reported to reduce/convert nitrite to NO. We evaluated the role and the physiological importance of CA for an extra-platelet CA/nitrite/NO/cGMP pathway in human platelets. Authentic NO was analyzed by an NO-sensitive electrode. GSNO and GS(15)NO were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). cGMP was determined by LC-MS/MS or RIA. In reduced glutathione (GSH) containing aqueous buffer (pH 7.4), human and bovine erythrocytic CAII-mediated formation of GSNO from nitrite and GS(15)NO from (15)N-nitrite. In the presence of L-cysteine and GSH, this reaction was accompanied by NO release. Incubation of nitrite with bovine erythrocytic CAII and recombinant soluble guanylyl cyclase resulted in cGMP formation. Upon incubation of nitrite with bovine erythrocytic CAII and washed human platelets, cGMP and P-VASP(S239) were formed in the platelets. This study provides the first evidence that extra-platelet nitrite and erythrocytic CAII may modulate platelet function in a cGMP-dependent manner. The new nitrite-dependent CA activity may be a general principle and explain the cardioprotective effects of inorganic nitrite in the vasculature. We propose that nitrous acid (ONOH) is the primary CA-catalyzed reaction product of nitrite. PMID:27129464

  16. The stoichiometric ratio during biological removal of inorganic carbon and nutrient in the Mississippi River plume and adjacent continental shelf

    Directory of Open Access Journals (Sweden)

    W.-J. Huang

    2012-02-01

    Full Text Available The stoichiometric ratios of dissolved inorganic carbon (DIC and nutrients during biological removal have been widely assumed to follow the Redfield ratios (especially the C/N ratio in large river plume ecosystems. However, this assumption has not been systematically examined and documented because DIC and nutrients are rarely studied simultaneously in a river plume area, a region in which they can be affected by strong river-ocean mixing as well as intense biological activity. We examined stoichiometric ratios of DIC, total alkalinity (TA, and nutrients (NO3, PO43− and Si(OH4 data during biological removal in the Mississippi River plume and adjacent continental shelf in June 2003 and August 2004 with biological removals defined as the difference between measured values and values predicted on the basis of conservative mixing determined using a multi-endmember mixing model. Despite complex physical and biogeochemical influences, relationships between DIC and nutrients were strongly dependent on salinity range and geographic location, and influenced by biological removal. Lower C/Si and N/Si ratios in one nearshore area were attributed to a potential silicate source induced by water exchange with coastal salt marshes. When net biological uptake was separated from river-ocean mixing and the impact of marshes and bays excluded, stoichiometric ratios of C/N/Si were similar to the Redfield ratios, thus supporting the applicability of the Redfield-type C/N/Si ratios as a principle in river-plume biogeochemical models.

  17. Emissions of Black Carbon, Organic, and Inorganic Aerosols From Biomass Burning in North America and Asia in 2008

    Science.gov (United States)

    Kondo, Y.; Matsui, H.; Moteki, N.; Sahu, L.; Takegawa, N.; Kajino, M.; Zhao, Y.; Cubison, M. J.; Jimenez, J. L.; Vay, S.; Diskin, G. S.; Anderson, B.; Wisthaler, A.; Mikoviny, T.; Fuelberg, H. E.; Blake, D. R.; Huey, G.; Weinheimer, A. J.; Knapp, D. J.; Brune, W. H.

    2011-01-01

    Reliable assessment of the impact of aerosols emitted from boreal forest fires on the Arctic climate necessitates improved understanding of emissions and the microphysical properties of carbonaceous (black carbon (BC) and organic aerosols (OA)) and inorganic aerosols. The size distributions of BC were measured by an SP2 based on the laser-induced incandescence technique on board the DC-8 aircraft during the NASA ARCTAS campaign. Aircraft sampling was made in fresh plumes strongly impacted by wildfires in North America (Canada and California) in summer 2008 and in those transported from Asia (Siberia in Russia and Kazakhstan) in spring 2008. We extracted biomass burning plumes using particle and tracer (CO, CH3CN, and CH2Cl2) data. OA constituted the dominant fraction of aerosols mass in the submicron range. The large majority of the emitted particles did not contain BC. We related the combustion phase of the fire as represented by the modified combustion efficiency (MCE) to the emission ratios between BC and other species. In particular, we derived the average emission ratios of BC/CO = 2.3 +/- 2.2 and 8.5 +/- 5.4 ng/cu m/ppbv for BB in North America and Asia, respectively. The difference in the BC/CO emission ratios is likely due to the difference in MCE. The count median diameters and geometric standard deviations of the lognormal size distribution of BC in the BB plumes were 136-141 nm and 1.32-1.36, respectively, and depended little on MCE. These BC particles were thickly coated, with shell/core ratios of 1.3-1.6. These parameters can be used directly for improving model estimates of the impact of BB in the Arctic.

  18. Ubiquitous dissolved inorganic carbon assimilation by marine bacteria in the Pacific Northwest coastal ocean as determined by stable isotope probing.

    Directory of Open Access Journals (Sweden)

    Suzanne DeLorenzo

    Full Text Available In order to identify bacteria that assimilate dissolved inorganic carbon (DIC in the northeast Pacific Ocean, stable isotope probing (SIP experiments were conducted on water collected from 3 different sites off the Oregon and Washington coasts in May 2010, and one site off the Oregon Coast in September 2008 and March 2009. Samples were incubated in the dark with 2 mM (13C-NaHCO(3, doubling the average concentration of DIC typically found in the ocean. Our results revealed a surprising diversity of marine bacteria actively assimilating DIC in the dark within the Pacific Northwest coastal waters, indicating that DIC fixation is relevant for the metabolism of different marine bacterial lineages, including putatively heterotrophic taxa. Furthermore, dark DIC-assimilating assemblages were widespread among diverse bacterial classes. Alphaproteobacteria, Gammaproteobacteria, and Bacteroidetes dominated the active DIC-assimilating communities across the samples. Actinobacteria, Betaproteobacteria, Deltaproteobacteria, Planctomycetes, and Verrucomicrobia were also implicated in DIC assimilation. Alteromonadales and Oceanospirillales contributed significantly to the DIC-assimilating Gammaproteobacteria within May 2010 clone libraries. 16S rRNA gene sequences related to the sulfur-oxidizing symbionts Arctic96BD-19 were observed in all active DIC assimilating clone libraries. Among the Alphaproteobacteria, clones related to the ubiquitous SAR11 clade were found actively assimilating DIC in all samples. Although not a dominant contributor to our active clone libraries, Betaproteobacteria, when identified, were predominantly comprised of Burkholderia. DIC-assimilating bacteria among Deltaproteobacteria included members of the SAR324 cluster. Our research suggests that DIC assimilation is ubiquitous among many bacterial groups in the coastal waters of the Pacific Northwest marine environment and may represent a significant metabolic process.

  19. A lipidomic approach to understanding free fatty acid lipogenesis derived from dissolved inorganic carbon within cnidarian-dinoflagellate symbiosis.

    Directory of Open Access Journals (Sweden)

    Simon R Dunn

    Full Text Available The cnidarian-dinoflagellate symbiosis is arguably one of the most important within the marine environment in that it is integral to the formation of coral reefs. However, the regulatory processes that perpetuate this symbiosis remain unresolved. It is essential to understand these processes, if we are to elucidate the mechanisms that support growth and resource accumulation by coral host, and conversely, recently observed reduction and/or mortality of corals in response to rapid environmental change. This study specifically focused on one area of metabolic activity within the symbiosis, that of free fatty acid synthesis within both the dinoflagellate symbionts and cnidarian host. The main model system used was Aiptasia pulchella and Symbiodinium sp. in combination with aposymbiotic A. pulchella, the symbiotic coral Acropora millepora system and dinoflagellate culture. Fatty acids (FAs were selected because of their multiple essential roles inclusive of energy storage (resource accumulation, membrane structure fluidity and cell signaling. The study addressed free FA lipogenesis by using a new method of enriched stable isotopic ((13C incorporation from dissolved inorganic carbon (DI(13C combined with HPLC-MS. FAs derived from DI(13C aligned with a mixture of known lipogenesis pathways with the addition of some unusual FAs. After 120 hr, (13C-enriched FA synthesis rates were attributed to only a complex integration of both n-3 and n-6 lipogenesis pathways within the dinoflagellate symbionts. Furthermore, there was no detectible evidence of symbiont derived enriched isotope fatty acids, catabolized (13C derivatives or DI(13C being directly utilized, in host late n-6 pathway long-chain FA lipogenesis. These findings do not align with a popular mutualistic translocation model with respect to the use of translocated symbiont photoassimilates in host long-chain FA lipogenesis, which has important connotations for linking nutrient sources with

  20. Synthesis of Carbon Nanotubes and Volatile Organic Compounds Detection

    Directory of Open Access Journals (Sweden)

    Sobri S.

    2016-01-01

    Full Text Available In this work, the adsorption effect of volatile organic compounds (chloroacetophenone, acetonitrile and hexane towards the change of resistance of CNTs pellet as sensor signal was investigated. CNTs used in this research were synthesized using Floating Catalyst – Chemical Vapor Deposition (FC-CVD method in optimum condition. The synthesized CNTs were characterized using Scanning Electron Microscopy (SEM, Transmission Electron Microscopy (TEM and Raman Spectroscopy. The variation of resistance changes towards the tested gases were recorded using a multimeter. CNTs sensor pellet showed good responses towards the tested gases, however, the sensitivity, response time and recovery time of sensor pellet need to be optimized.

  1. Automated determination of the stable carbon isotopic composition (δ13C) of total dissolved inorganic carbon (DIC) and total nonpurgeable dissolved organic carbon (DOC) in aqueous samples: RSIL lab codes 1851 and 1852

    Science.gov (United States)

    Révész, Kinga M.; Doctor, Daniel H.

    2014-01-01

    The purposes of the Reston Stable Isotope Laboratory (RSIL) lab codes 1851 and 1852 are to determine the total carbon mass and the ratio of the stable isotopes of carbon (δ13C) for total dissolved inorganic carbon (DIC, lab code 1851) and total nonpurgeable dissolved organic carbon (DOC, lab code 1852) in aqueous samples. The analysis procedure is automated according to a method that utilizes a total carbon analyzer as a peripheral sample preparation device for analysis of carbon dioxide (CO2) gas by a continuous-flow isotope ratio mass spectrometer (CF-IRMS). The carbon analyzer produces CO2 and determines the carbon mass in parts per million (ppm) of DIC and DOC in each sample separately, and the CF-IRMS determines the carbon isotope ratio of the produced CO2. This configuration provides a fully automated analysis of total carbon mass and δ13C with no operator intervention, additional sample preparation, or other manual analysis. To determine the DIC, the carbon analyzer transfers a specified sample volume to a heated (70 °C) reaction vessel with a preprogrammed volume of 10% phosphoric acid (H3PO4), which allows the carbonate and bicarbonate species in the sample to dissociate to CO2. The CO2 from the reacted sample is subsequently purged with a flow of helium gas that sweeps the CO2 through an infrared CO2 detector and quantifies the CO2. The CO2 is then carried through a high-temperature (650 °C) scrubber reactor, a series of water traps, and ultimately to the inlet of the mass spectrometer. For the analysis of total dissolved organic carbon, the carbon analyzer performs a second step on the sample in the heated reaction vessel during which a preprogrammed volume of sodium persulfate (Na2S2O8) is added, and the hydroxyl radicals oxidize the organics to CO2. Samples containing 2 ppm to 30,000 ppm of carbon are analyzed. The precision of the carbon isotope analysis is within 0.3 per mill for DIC, and within 0.5 per mill for DOC.

  2. Inorganic Fullerene-Like Nanoparticles and Inorganic Nanotubes

    OpenAIRE

    Reshef Tenne; Enyashin, Andrey N.

    2014-01-01

    Fullerene-like nanoparticles (inorganic fullerenes; IF) and nanotubes of inorganic layered compounds (inorganic nanotubes; INT) combine low dimensionality and nanosize, enhancing the performance of corresponding bulk counterparts in their already known applications, as well as opening new fields of their own [1]. This issue gathers articles from the diverse area of materials science and is devoted to fullerene-like nanoparticles and nanotubes of layered sulfides and boron nitride and collects...

  3. Nitrogen Doped Carbon Nanotubes from Organometallic Compounds: A Review

    Directory of Open Access Journals (Sweden)

    Neil J. Coville

    2010-03-01

    Full Text Available Nitrogen doped carbon nanotubes (N-CNTs have become a topic of increased importance in the study of carbonaceous materials. This arises from the physical and chemical properties that are created when N is embedded in a CNT. These properties include modified chemical reactivity and modified conductivity and mechanical properties. A range of methodologies have been devised to synthesize N-CNTs. One of the procedures uses a floating catalyst in which an organometallic complex is decomposed in the gas phase in the presence of a nitrogen containing reactant to give N-CNTs. Most studies have been limited to ferrocene, ring substituted ferrocene and Fe(CO5. This review covers the synthesis (and properties of N-CNTs and other shaped carbon nanomaterials (SCNMs produced using organometallic complexes. It summarizes the effects that physical parameters such as temperature, pressure, gas flow rates, type and concentration of N source etc. have on the N-CNT type, size and yields as well as the nitrogen content incorporated into the tubes that are produced from organometallic complexes. Proposed growth models for N-CNT synthesis are also reported.

  4. Tracing organic compounds in aerobically altered methane-derived carbonate pipes (Gulf of Cadiz, SW Iberia)

    Science.gov (United States)

    Merinero, Raúl; Ruiz-Bermejo, Marta; Menor-Salván, César; Lunar, Rosario; Martínez-Frías, Jesús

    2012-07-01

    The primary geochemical process at methane seeps is anaerobic oxidation of methane (AOM), performed by methanotrophic archaea and sulfate-reducing bacteria (SRB). The molecular fingerprints (biomarkers) of these chemosynthetic microorganisms can be preserved in carbonates formed through AOM. However, thermal maturity and aerobic degradation can change the original preserved compounds, making it difficult to establish the relation between AOM and carbonate precipitation. Here we report a study of amino acid and lipid abundances in carbonate matrices of aerobically altered pipes recovered from the seafloor of the Gulf of Cadiz (SW Iberian Peninsula). This area is characterized by a complex tectonic regime that supports numerous cold seeps. Studies so far have not determined whether the precipitation of carbonate pipes in the Gulf of Cadiz is a purely chemical process or whether microbial communities are involved. Samples from this site show signs of exposure to oxygenated waters and of aerobic alteration, such as oxidation of authigenic iron sulfides. In addition, the degradation index, calculated from the relative abundance of preserved amino acids, indicates aerobic degradation of organic matter. Although crocetane was the only lipid identified from methanotrophic archaea, the organic compounds detected (n-alkanes, regular isoprenoids and alcohols) are compatible with an origin from AOM coupled with bacterial sulfate reduction (BSR) and subsequent aerobic degradation. We establish a relation among AOM, BSR and pipe formation in the Gulf of Cadiz through three types of analysis: (1) stable carbon and oxygen isotopic composition of carbonate minerals; (2) carbonate microfabrics; and (3) mineralogical composition. Our results suggest that carbonate pipes may form through a process similar to the precipitation of vast amounts of carbonate pavements often found at cold seeps. Our approach suggests that some organic compound patterns, in combination with additional

  5. Concentration-dependent polyparameter linear free energy relationships to predict organic compound sorption on carbon nanotubes

    OpenAIRE

    Zhao, Qing; YANG Kun; Li, Wei; Xing, Baoshan

    2014-01-01

    Adsorption of organic compounds on carbon nanotubes (CNTs), governed by interactions between molecules and CNTs surfaces, is critical for their fate, transport, bioavailability and toxicity in the environment. Here, we report a promising concentration-dependent polyparameter linear free energy relationships (pp-LFERs) model to describe the compound-CNTs interactions and to predict sorption behavior of chemicals on CNTs in a wide range of concentrations (over five orders of magnitude). The dev...

  6. Inorganic Crystal Structure Database (ICSD)

    Science.gov (United States)

    SRD 84 FIZ/NIST Inorganic Crystal Structure Database (ICSD) (PC database for purchase)   The Inorganic Crystal Structure Database (ICSD) is produced cooperatively by the Fachinformationszentrum Karlsruhe(FIZ) and the National Institute of Standards and Technology (NIST). The ICSD is a comprehensive collection of crystal structure data of inorganic compounds containing more than 140,000 entries and covering the literature from 1915 to the present.

  7. Covering vertically aligned carbon nanotubes with a multiferroic compound

    KAUST Repository

    Mahajan, Amit

    2014-10-30

    This work highlights the possible use of vertically-aligned multiwall carbon nanotubes (VA-MWCNTs) as bottom electrodes for microelectronics, for example for memory applications. As a proof of concept BiFeO3 (BFO) films were fabricated in-situ deposited on the surface of VA-MWCNTs by RF (radio frequency) magnetron sputtering. For in situ deposition temperature of 400 °C and deposition time up to 2 h, BFO films cover the MWCNTs and no damage occurs either in the film or MWCNTs. In spite of the macroscopic lossy polarization behaviour, the ferroelectric nature, domain structure and switching of these conformal BFO films was verified by piezo force microscopy. G type antiferromagnetic ordering with weak ferromagnetic ordering loop was proved for BFO films on VA-MWCNTs having a coercive field of 700 Oe.

  8. Synthesis of Heteroaromatic Compounds by Oxidative Aromatization Using an Activated Carbon/Molecular Oxygen System

    Directory of Open Access Journals (Sweden)

    Masahiko Hayashi

    2009-08-01

    Full Text Available A variety of heteroaromatic compounds, such as substituted pyridines, pyrazoles, indoles, 2-substituted imidazoles, 2-substituted imidazoles, 2-arylbenzazoles and pyrimidin-2(1H-ones are synthesized by oxidative aromatization using the activated carbon and molecular oxygen system. Mechanistic study focused on the role of activated carbon in the synthesis of 2-arylbenzazoles is also discussed. In the final section, we will disclose the efficient synthesis of substituted 9,10-anthracenes via oxidative aromatization.

  9. Improvement of Water-Repellency Homogeneity by Compound Fluorine-Carbon Sprayed Coating and Silane Treatment

    OpenAIRE

    FUTAMATA, Masami; Gai, Xiaohui; ITOH, Hidenobu; 伊藤, 英信

    2004-01-01

    To improve the water-repellency of materials, a composite coating of fluorine-carbon has been developed in this study. A thermal sprayed coating produced by using a compound fluorine-carbon cored wire exhibits excellent water-repellency. However, the contact angles of water of the coating surface show remarkable scatters since the fluorine is usually difficult to be distributed uniformly on the coating surface. To improve the homogeneity of the water-repellency of the thermal sprayed coating,...

  10. Inorganic Carbon-Stimulated O2 Photoreduction Is Suppressed by NO2- Assimilation in Air-Grown Cells of Synechococcus UTEX 625.

    Science.gov (United States)

    Mir, N. A.; Salon, C.; Canvin, D. T.

    1995-12-01

    The effect of NO2- assimilation on O2 exchange and CO2 fixation of the cyanobacterium, Synechococcus UTEX 625, was studied mass spectrometrically. Upon addition of 1 mM inorganic carbon to the medium, inorganic carbon pools developed and accelerated O2 photoreduction 5-fold when CO2 fixation was inhibited. During steady-state photosynthesis at saturating light, O2 uptake represented 32% of O2 evolution and balanced that portion of O2 evolution that could not be accounted for by CO2 fixation. Under these conditions, NO2- assimilation reduced O2 uptake by 59% but had no influence on CO2 fixation. NO2- assimilation decreased both CO2 fixation and O2 photoreduction at low light and and increased net O2 evolution at all light intensities. The increase in net O2 evolution observed during simultaneous assimilation of carbon and nitrogen over carbon alone was due to a suppression of O2 photoreduction by NO2- assimilation. When CO2 fixation was precluded, NO2- assimilation inhibited O2 photoreduction and stimulated O2 evolution. When the electron supply was limiting (low light), competition among O2, CO2, and NO2- for electrons could be observed, but when the electron supply was not limiting (saturating light), O2 photoreduction and/or NO2- reduction caused electron transport that was additive to that for maximum CO2 fixation. PMID:12228670

  11. Preparation of polymeric fibers immobilizing inorganic compounds, enzymes, and extractants designed for radionuclide decontamination, ultrapure water production, and rare-earth metal purification

    International Nuclear Information System (INIS)

    To remove and recover targeted ions and molecules at a high rate, inorganic compounds, enzymes, and extractants were immobilized onto a commercially available 6-nylon fiber by radiation-induced graft polymerization and subsequent chemical modifications. Fibrous supports with a smaller diameter provide a larger external interface area with liquids. Modified fibers are fabricated into various shapes such as wound filter and braid according to application sites. First, insoluble cobalt ferrocyanide-impregnated fiber was prepared via precipitation by immersing ferrocyanide ion-bound anion-exchange fiber in cobalt chloride solution. Cobalt ferrocyanide impregnated onto the polymer chain grafted onto the fiber specifically captured cesium ions in seawater. Similarly, sodium titanate impregnated onto a cation-exchange fiber selectively captured strontium ions in seawater. Second, urease was bound by an anion-exchange graft chain, followed by enzymatic cross-linking among urease molecules with transglutaminase. The bed charged with the urease-immobilized fiber exhibited a quantitative hydrolysis of urea at a high space velocity of urea solution. Third, an acidic extractant (HDEHP, bis(2-ethylhexyl) phosphate) was impregnated onto a dodecylamino-group-containing polymer chain grafted onto the 6-nylon fiber. Distribution coefficients of the HDEHP-impregnated fiber for neodymium and dysprosium agreed well with those in n-dodecane. (author)

  12. Methods development for separation of inorganic anions, organic acids and bases, and neutral organic compounds by ion chromatography and capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Li, J.

    1999-04-01

    A novel anion-exchange resin containing three amine groups was prepared by reaction of a chloromethylated polystyrene-divinylbenzene (PS-DVB) resin with diethylenetriamine. After being protonated by contact with an aqueous acid, this resin can be used for ion chromatographic separation of anions. The charge on the resins can be varied from +1 to +3 by changing the mobile phase pH. The selectivity of the new ion exchangers for various inorganic anions was quite different from that of conventional anion exchangers. The performance of this new anion exchanger was studied by changing the pH and the concentration of the eluent, and several different eluents were used with some common anions as testing analytes. Conductivity detection and UV-visible detection were applied to detect the anions after separation. The new resin can also be used for HPLC separation of neutral organic compounds. Alkylphenols and alkylbenzenes were separated with this new polymeric resin, and excellent separations were obtained under simple conditions. This report contains Chapter 1: General introduction and Chapter 6: General conclusions.

  13. Carbon Nanomaterials Based Electrochemical Sensors/Biosensors for the Sensitive Detection of Pharmaceutical and Biological Compounds.

    Science.gov (United States)

    Adhikari, Bal-Ram; Govindhan, Maduraiveeran; Chen, Aicheng

    2015-01-01

    Electrochemical sensors and biosensors have attracted considerable attention for the sensitive detection of a variety of biological and pharmaceutical compounds. Since the discovery of carbon-based nanomaterials, including carbon nanotubes, C60 and graphene, they have garnered tremendous interest for their potential in the design of high-performance electrochemical sensor platforms due to their exceptional thermal, mechanical, electronic, and catalytic properties. Carbon nanomaterial-based electrochemical sensors have been employed for the detection of various analytes with rapid electron transfer kinetics. This feature article focuses on the recent design and use of carbon nanomaterials, primarily single-walled carbon nanotubes (SWCNTs), reduced graphene oxide (rGO), SWCNTs-rGO, Au nanoparticle-rGO nanocomposites, and buckypaper as sensing materials for the electrochemical detection of some representative biological and pharmaceutical compounds such as methylglyoxal, acetaminophen, valacyclovir, β-nicotinamide adenine dinucleotide hydrate (NADH), and glucose. Furthermore, the electrochemical performance of SWCNTs, rGO, and SWCNT-rGO for the detection of acetaminophen and valacyclovir was comparatively studied, revealing that SWCNT-rGO nanocomposites possess excellent electrocatalytic activity in comparison to individual SWCNT and rGO platforms. The sensitive, reliable and rapid analysis of critical disease biomarkers and globally emerging pharmaceutical compounds at carbon nanomaterials based electrochemical sensor platforms may enable an extensive range of applications in preemptive medical diagnostics. PMID:26404304

  14. Carbon Nanomaterials Based Electrochemical Sensors/Biosensors for the Sensitive Detection of Pharmaceutical and Biological Compounds

    Directory of Open Access Journals (Sweden)

    Bal-Ram Adhikari

    2015-09-01

    Full Text Available Electrochemical sensors and biosensors have attracted considerable attention for the sensitive detection of a variety of biological and pharmaceutical compounds. Since the discovery of carbon-based nanomaterials, including carbon nanotubes, C60 and graphene, they have garnered tremendous interest for their potential in the design of high-performance electrochemical sensor platforms due to their exceptional thermal, mechanical, electronic, and catalytic properties. Carbon nanomaterial-based electrochemical sensors have been employed for the detection of various analytes with rapid electron transfer kinetics. This feature article focuses on the recent design and use of carbon nanomaterials, primarily single-walled carbon nanotubes (SWCNTs, reduced graphene oxide (rGO, SWCNTs-rGO, Au nanoparticle-rGO nanocomposites, and buckypaper as sensing materials for the electrochemical detection of some representative biological and pharmaceutical compounds such as methylglyoxal, acetaminophen, valacyclovir, β-nicotinamide adenine dinucleotide hydrate (NADH, and glucose. Furthermore, the electrochemical performance of SWCNTs, rGO, and SWCNT-rGO for the detection of acetaminophen and valacyclovir was comparatively studied, revealing that SWCNT-rGO nanocomposites possess excellent electrocatalytic activity in comparison to individual SWCNT and rGO platforms. The sensitive, reliable and rapid analysis of critical disease biomarkers and globally emerging pharmaceutical compounds at carbon nanomaterials based electrochemical sensor platforms may enable an extensive range of applications in preemptive medical diagnostics.

  15. Determination of inorganic compounds in drinking water on the basis of house water heater scale, part 1: Determination of heavy metals and uranium

    Directory of Open Access Journals (Sweden)

    Rajković Miloš B.

    2004-01-01

    Full Text Available The analysis of scale originated from drinking water on the house water heater, showed that scale is basically calcium carbonate that crystallizes hexagonally in the form of calcite. Scale taken as a sample from different spots in Belgrade – upper town of Zemun (sample 1 and Pančevo (sample 2 showed different configuration although it came from the same waterworks. That indicates either that the water flowing through waterworks pipes in different parts of the city is not the same or the waterworks net is not the same (age, maintaining, etc. All the elements which are dominant in drinking water (Ca, Mg, K, and Na, and which could be found in water by natural processes, are by their content far below the values regulated by law. The analysis also showed the presence of many metals: Ti, Pb, Zn, Cu Li, Sr, Cd, and Cr in the first sample, which are not found in the scale taken near Pančevo. The results obtained by calculating the mass concentration in drinking water on the basis of scale content, showed that both waters belonged to the category of low mineral waters. Contents of inorganic substances in these waters (117.85 mg/dm3 for sample 1 or 80.83 mg/dm3 for sample 2 are twice lower than the values predicted by the legislation. Gammaspectrometric analysis indicates the presence of radioactive elements – uranium and strontium which can influence human health.

  16. Characterization of carbon, sulfur and volatile compounds in nuclear fuel U3SI2-AL

    International Nuclear Information System (INIS)

    The scope of this work is to describe the characterization of Carbon, Sulfur and Volatile Compounds in nuclear fuel U3Si2-Al used in a research pool type reactor with 5 KW power capacities, located in Sao Paulo, Brazil. This reactor produces a large range of radioisotopes for radiopharmaceutical needed in Brazil nuclear medicine. The fabrication of the fuel U3Si2-Al plate is the key of the whole assembly production and its quality directly affects the safety and reliability of the fuel assembly performance. For this reason, it is very necessary to analyze the Carbon, Sulfur and Volatile Compounds to avoid damage in the fuel plate. The Carbon and Sulfur are characterized by the method of radio frequency furnace gas extraction system coupled with infrared cell detector. The Volatile Compounds are characterized by the method of heat gas extraction coupled with gravimetric technique. These methods are recommended by American Society for Testing Materials ASTM for nuclear materials. The average carbon and sulfur analyzed are 30 μg/g and 3 μg/g, respectively. The average for Volatile Compounds is 40 μg/g. These results represent satisfactory performance of the fuel inside the nuclear reactor. A statistical laboratory program has been set to validate the data generated in the nuclear fuel material to specify any agreement with the recommended ASTM methods. (author)

  17. Selective adsorption for removal of nitrogen compounds from hydrocarbon streams over carbon-based adsorbents

    Science.gov (United States)

    Almarri, Masoud S.

    The ultimate goal of this thesis is to develop a fundamental understanding of the role of surface oxygen functional groups on carbon-based adsorbents in the adsorption of nitrogen compounds that are known to be present in liquid fuels. N2 adsorption was used to characterize pore structures. The surface chemical properties of the adsorbents were characterized by X-ray photoelectron spectroscopy (XPS) and temperature-programmed desorption (TPD) techniques with a mass spectrometer to identify and quantify the type and concentration of oxygen functional groups on the basis of CO2 and CO evolution profiles. It was found that although surface area and pore size distribution are important for the adsorption process, they are not primary factors in the adsorption of nitrogen compounds. On the other hand, both the type and concentration of surface oxygen-containing functional groups play an important role in determining adsorptive denitrogenation performance. Higher concentrations of the oxygen functional groups on the adsorbents resulted in a higher adsorption capacity for the nitrogen compounds. A fundamental insight was gained into the contributions of different oxygen functional groups by analyzing the changes in the monolayer maximum adsorption capacity, qm, and the adsorption constant, K, for nitrogen compounds on different activated carbons. Acidic functional groups such as carboxylic acids and carboxylic anhydrides appear to contribute more to the adsorption of quinoline, while the basic oxygen functional groups such as carbonyls and quinones enhance the adsorption of indole. Despite the high number of publications on the adsorptive desulfurization of liquid hydrocarbon fuels, these studies did not consider the presence of coexisting nitrogen compounds. It is well-known that, to achieve ultraclean diesel fuel, sulfur must be reduced to a very low level, where the concentrations of nitrogen and sulfur compounds are comparable. The adsorptive denitrogenation and

  18. Dissolved inorganic carbon and pCO2 in two small streams draining different soil types in Southwestern Amazonia, Brazil

    OpenAIRE

    Simone Rebecca Alin; Alex Vladimir Krusche; Reynaldo Luiz Victoria; Cleber Ibraim Salimon; Eliete dos Santos Sousa; Nei Kavaguichi Leite

    2008-01-01

    The objective of this study was to determine the dissolved inorganic carbon (DIC) and pCO2 concentrations in two third order streams in southwestern Amazonia, Brazil. From May 2004 to June 2005 water dissolved oxygen, pH, electrical conductivity, temperature were measured to stream water chemical and physical description. DIC and pCO2 measurements were made by headspace extraction and gas samples for pCO2 and DIC extractions were run on an infrared gas analyzer (IRGA, LI-COR Instruments model...

  19. 蓖麻粕基生物有机无机复混肥及其应用%Castor Bean Cereal Based Bio-Organic-Inorganic Compound Fertilizers and Use

    Institute of Scientific and Technical Information of China (English)

    陈绍荣; 邵建华; 赵立新; 刘园园

    2014-01-01

    简要介绍了蓖麻粕基生物有机无机复混肥的性能及特点。通过玉米、水稻、花生大田肥效试验,结果证明蓖麻粕基生物有机无机复混肥具有较好的增产改土效果,可在粮油作物上推广应用。%A brief account is given of the properties and features of castor bean cereal based bio-organic-inorganic compound fertilizers.By field experiment of fertilizer efficiency with corn, rice and peanut , it is proved that castor bean cereal based bio-organic-inorganic compound fertilizers have better effects on increasing production and improving the properities of soil, and can be widely applied to grain and oil crops.

  20. Microbial oxidation and reduction of inorganic sulphur compounds in relation to the development and control of microorganisms active in leaching operations. Part of a coordinated programme on bacterial leaching of uranium ores

    International Nuclear Information System (INIS)

    The project considers the use of Thiobacillus ferroxidans type bacteria for the leaching of metals from ores. The various ways by which Thiobacillus ferroxidans utilizes inorganic sulfur compounds for oxidation, energy, growth and synthesis of cellular material were studied. The report briefly describes the scope and background of the project, and a list of publications describing experimental methods and research materials used is given. Unpublished work commenced during the Research Contract includes three major projects: (1) Transition of Thiobacillus ferroxidans from heterotrophic growth on fucose to autotropic growth on ferrous-iron; (2) development of a method to determine the ATP-content of bacteria attached to ore particles; (3) microbiological and chemical interactions of inorganic sulfur compounds. These three projects are summarized briefly

  1. Synthesis of carbon nanotubes by catalytic pyrolysis method with Feitknecht compound as precursor of NiZnAl catalyst

    Institute of Scientific and Technical Information of China (English)

    Yan Xiaoqi; Liu Quanrun; Zhang Songlin; Zhang Kun; Chen Jiuling; Li Yongdan

    2004-01-01

    Carbon nanotubes are synthesized by catalytic pyrolysis method with a kind of new type catalyst--nickel-zinc-alumina catalyst prepared from Feitknecht compound. Tubular carbon nanotubes, bamboo-shaped carbon naotubes, herringbone carbon nanotubues and branched carbon nanotubes are all found formed at moderate temperature. It is important for the formation of quasi-liquid state of the metal nanoparticles at the tip of carbon naotubes during the growth of carbon nanotubes to lead to different kinds of carbon nanotubes. It is likely that the addition of zinc make the activity of nickel catalyst after calcinations and reduction changed strangely.

  2. Geochemical investigations into the retention of reactive carbon compounds for toxic heavy metals. Final report; Geochemische Untersuchungen zur Retention von reaktiven Kohlenstoffverbindungen fuer toxische Schwermetalle. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Kupsch, H.; Mansel, A.; Crustewitz, C.

    2003-03-01

    The composition, reactivity and stability of reactive organic carbon compounds adsorbed on geogenic matrices was investigated. The surface deposits of NOM and its dependence on geochemical parameters was investigated in selected geomatrices. The retention of toxic heavy metals on these surface deposits of NOM was investigated in consideration of the presence of hydroxy species and inorganic ligands. The investigations of the reactivity of the NOM species requires analyses of these compounds and of the heavy metals in the ultratracer region. This was possible by means of radiochemical methods that were further developed in the context of this project. Radioactive labeling of identified reactive carbon compounds, e.g. with radioactive iodine, on the one hand, and the use of radioactive Cu, Pb, Hg isotopes on the other hand enabled speciation analyses in the binary systems (heavy metal + geomatrix, heavy metal + reactive carbon compounds, reactive carbon compounds + geomatrix) and especially in the ternary system (heavy metal + geomatrix + reactive carbon compounds) in defined conditions. The special labelling techniques were a precondition for distribution measurements in the near-natural, low concentration range. (orig.) [German] Ziel des Projektes war es, mit der vorhandenen Analytik und Expertise die Zusammensetzung, die Reaktivitaet und die Stabilitaet der auf den geogenen Matrizes sorbierten reaktiven organischen Kohlenstoffverbindungen und die damit verbundenen Stoffumsaetze aufzuklaeren. An ausgewaehlten Geomatrizes wurde die Ausbildung von Oberflaechendepositen des NOM und deren Abhaengigkeit gegenueber geochemischen Parametern untersucht. Unter der Beruecksichtigung der Gegenwart von Hydroxyspezies und anorganischen Liganden wurde die Retention toxischer Schwermetalle an diesen Oberflaechendepositen des NOM untersucht. Die Untersuchungen zur Reaktivitaet der NOM-Spezies setzt eine Analytik dieser Verbindungen und der Schwermetalle im Ultraspurenbereich

  3. Expression of the pyr operon of Lactobacillus plantarum is regulated by inorganic carbon availability through a second regulator, PyrR2, homologous to the pyrimidine-dependent regulator PyrR1

    DEFF Research Database (Denmark)

    Arsène-Ploetze, Florence; Valérie Kugler, Valérie; Martinussen, Jan; Bringel, Françoise

    2006-01-01

    Inorganic carbon (IC), such as bicarbonate or carbon dioxide, stimulates the growth of Lactobacillus plantarum. At low IC levels, one-third of natural isolated L. plantarum strains are nutritionally dependent on exogenous arginine and pyrimidine, a phenotype previously defined as high-CO2-requiri...

  4. Nuclear graphite waste's behaviour under disposal conditions: Study of the release and repartition of organic and inorganic forms of carbon 14 and tritium in alkaline media

    International Nuclear Information System (INIS)

    23000 tons of graphite wastes will be generated during dismantling of the first generation of French reactors (9 gas cooled reactors). These wastes are classified as Long Lived Low Level wastes (LLW-LL). As requested by the law, the French National Radioactive Waste Management Agency (Andra) is studying concepts of low-depth disposals.In this work we focus on carbon 14, the main long-lived radionuclide in graphite waste (5730 y), but also on tritium, which is the main contributor to the radioactivity in the short term. Carbon 14 and tritium may be released from graphite waste in many forms in gaseous phase (14CO2, HT...) or in solution (14CO32-, HTO...). Their speciation will strongly affect their migration from the disposal site to the environment. Leaching experiments, in alkaline solution (0.1 M NaOH simulating repository conditions) have been performed on irradiated graphite, from Saint-Laurent A2 and G2 reactors, in order to quantify their release and characterize their speciation. The studies show that carbon 14 exists in both gaseous and aqueous phases. In the gaseous phase, release is weak (≤0.1%) and corresponds to oxidizable species. Carbon 14 is mainly released into liquid phase, as both inorganic and organic species. 65% of released fraction is inorganic and 35% organic carbon. Two tritiated species have been identified in gaseous phase: HTO and HT/Organically Bond Tritium. More than 90% of tritium in that phase corresponds to HT/OBT. But release is weak (≤0.1%). HTO is mainly in the liquid phase. (author)

  5. Carbon transfer in soil - plant system. Molecular labelling utilization for determining rhizosphere compounds

    International Nuclear Information System (INIS)

    The growing up of the bacteria developing in the rhizosphere of plants is dependent on the compounds exudation by plant roots. Even the bacterial genetics use has permitted to identify diverse functions involved in the process of the rhizosphere colonisation ( mobility, heterotrophic bacteria, growing rate, antibiotics production), there is a big delay in vegetal partners. To decrease this delay we tried to characterize the interactions between a plant model, Arabidopsis thaliana and the rhizosphere bacteria. An experimental device has been conceived for measuring the transfer of carbon issued from the photosynthesis to roots and soil. The exudation by roots has been studied. The analysis of rhizospheric compounds in situ pose some methodological problems, especially, the rhizospheric compounds must be extracted from the soil matrix. we suggest an analysis method of rhizospheric compound and of their dynamics. (F.M.)

  6. Adsorption studies of recalcitrant compounds of molasses spentwash on activated carbons.

    Science.gov (United States)

    Figaro, S; Louisy-Louis, S; Lambert, J; Ehrhardt, J-J; Ouensanga, A; Gaspard, S

    2006-10-01

    Due to high levels of residual chemical oxygen demand (COD) in the effluent of molasses spentwash (MSW) after anaerobic treatment, acceptable COD levels for discharge cannot be achieved without some form of post-treatment. In this study, the particulate composition of molasses spentwash after anaerobic digestion (MSWD), is characterised as to its particle size distribution, using micro- and ultrafiltration and three activated carbons are characterised as to their ability to reduce significantly the COD of MSWD effluent. The activated carbons tested as adsorbent, were characterised by XPS spectroscopy, elemental analysis, surface area, pore size distribution, and acid-base titration using the Boehm's method. Adsorption of phenol, used here as a reference compound, and of some organic compounds contained in MSWD (gallic acid, tannic acid, and melanoidin, respectively), was studied. It was clearly demonstrated that an activated carbon with a significant distribution of both micropores and mesopores and a significant amount of macropores that are assumed to act as conduits providing access to micro- and mesopores, have a good adsorption efficiency for compounds such as tannic acid and melanoidins. It is a good adsorbent for melanoidin and coloured compounds of MSWD, which represents a large source of the aqueous pollution in sugar cane industries. PMID:16987542

  7. Investigation of the influence of liquid water films on O3 and PAN deposition on plant leaf surfaces treated with organic / inorganic compounds

    Science.gov (United States)

    Sun, Shang; Moravek, Alexander; von der Heyden, Lisa; Held, Andreas; Kesselmeier, Jürgen; Sörgel, Matthias

    2016-04-01

    Liquid water films on environmental surfaces play an important role in various fields of interest (Burkhardt and Eiden, 1994). For example, the deposition of water soluble trace gases could be increased by surface moisture. Chameides and Stelson (1992) found out that the dissolution of trace gases in airborne particulate matter increases with rising water/solid ratio of the particles. Further, Flechard et al. (1999) concluded that deliquescent salt particles represent a potential sink for trace gases, depending on their chemical property. The formation of surface water films and its influence on the gas deposition was proposed by many previous studies (Fuentes and Gillespie, 1992, Burkhardt and Eiden, 1994, van Hove et al., 1989, Burkhardt et al., 1999, Flechard et al., 1999). In this study we investigate the influence of leaf surface water films on the deposition of O3 and PAN under controlled laboratory conditions. A twin cuvette system described in Sun et al. (2015) was used to control the environmental parameters such as light, temperature, trace gas mixing ratio and humidity. Furthermore, the leaf surface was treated with various organic and inorganic solutions to investigate the influence of deposited compounds on the electrical surface conductance of the leaves and the surface deposition of O3 and PAN at various relative humidities. The result shows that RHcrit, where the electrical surface conductance (G) increases exponentially, was 40 % during the light period and 50 % during the dark period. Furthermore, we observed that the formation of the leaf surface liquid film was depended on the deposited compounds on the leaf cuticles. For the O3 deposition on plants (Quercus ilex) a clear enhancement at rising environmental air humidity under light and dark condition was found. The increase during light conditions can be related partly to increasing stomatal conductance with higher RH. From the non-stomatal deposition measured in dark experiments, we could

  8. Hydrogen isotopic compositions of organic compounds in plants reflect the plant's carbon metabolism

    Science.gov (United States)

    Cormier, M. A.; Kahmen, A.; Werner, R. A.

    2015-12-01

    The main factors controlling δ2H of plant organic compounds are generally assumed to be the plant's source water and the evaporative deuterium enrichment of leaf water. Hydrogen isotope analyses of plant compounds from sediments or tree rings are therefore mainly applied to assess hydrological conditions at different spatial and temporal scales. However, the biochemical hydrogen isotope fractionation occurring during biosynthesis of plant organic compounds (ɛbio) also accounts for a large part of the variability observed in the δ2H values. Nevertheless, only few studies have directly addressed the physiological basis of this variability and even fewer studies have thus explored possible applications of hydrogen isotope variability in plant organic compounds for plant physiological research. Here we show two datasets indicating that the plant's carbon metabolism can have a substantial influence on δ2H values of n-alkanes and cellulose. First, we performed a controlled experiment where we forced plants into heterotrophic and autotrophic C-metabolism by growing them under four different light treatments. Second, we assessed the δ2H values of different parasitic heterotrophic plants and their autotrophic host plants. Our two datasets show a systematic shift in ɛbio of up to 80 ‰ depending on the plant's carbon metabolism (heterotrophic or autotrophic). Differences in n-alkane and cellulose δ2H values in plants with autotrophic vs. heterotrophic metabolisms can be explained by different NADPH pools that are used by the plants to build their compounds either with assimilates that originate directly from photosynthesis or from stored carbohydrates. Our results have significant implications for the calibration and interpretation of geological records. More importantly, as the δ2H values reflect the plant's carbon metabolism involved during the tissue formation, our findings highlight the potential of δ2H values as new tool for studying plant and ecosystem carbon

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

    International Nuclear Information System (INIS)

    A new method has been developed and tested for determining chronological profiles of organic pollutants. This method, Carbon Isotope Analysis (CIA), involves measurements of 12C, 13C and 14C 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-C14). 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 12C and 13C 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 13C/12C ratio. Combining the information from both the 13C analysis and 14C 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

  10. Correlation and prediction of adsorption capacity and affinity of aromatic compounds on carbon nanotubes.

    Science.gov (United States)

    Wu, Wenhao; Yang, Kun; Chen, Wei; Wang, Wendi; Zhang, Jie; Lin, Daohui; Xing, Baoshan

    2016-01-01

    Adsorption of 22 nonpolar and polar aromatic compounds on 10 carbon nanotubes (CNTs) with various diameters, lengths and surface oxygen-containing group contents was investigated to develop predictive correlations for adsorption, using the isotherm fitting of Polanyi theory-based Dubinin-Ashtakhov (DA) model. Adsorption capacity of aromatic compounds on CNTs is negatively correlated with melting points of aromatic compounds, and surface oxygen-containing group contents and surface area ratios of mesopores to total pores of CNTs, but positively correlated with total surface area of CNTs. Adsorption affinity is positively correlated with solvatochromic parameters of aromatic compounds, independent of tube lengths and surface oxygen-containing group contents of CNTs, but negatively correlated with surface area ratios of mesopores to total pores of CNTs. The correlations of adsorption capacity and adsorption affinity with properties of both aromatic compounds and CNTs clearly have physical significance, can be used successfully with DA model to predict adsorption of aromatic compounds on CNTs from the well-known physiochemical properties of aromatic compounds (i.e., solvatochromic parameters, melting points) and CNTs (i.e., surface area and total acidic group contents), and thus can facilitate the environmental application of CNTs as sorbents and environmental risk assessment of both aromatic contaminants and CNTs. PMID:26521219

  11. Mixed low-dimensional nanomaterial: 2D ultranarrow MoS2 inorganic nanoribbons encapsulated in quasi-1D carbon nanotubes.

    Science.gov (United States)

    Wang, Zhiyong; Li, Hong; Liu, Zheng; Shi, Zujin; Lu, Jing; Suenaga, Kazu; Joung, Soon-Kil; Okazaki, Toshiya; Gu, Zhennan; Zhou, Jing; Gao, Zhengxiang; Li, Guangping; Sanvito, Stefano; Wang, Enge; Iijima, Sumio

    2010-10-01

    Quasi-one-dimensional nanotubes and two-dimensional nanoribbons are two fundamental forms of nanostructures, and integrating them into a novel mixed low-dimensional nanomaterial is fascinating and challenging. We have synthesized a stable mixed low-dimensional nanomaterial consisting of MoS(2) inorganic nanoribbons encapsulated in carbon nanotubes (which we call nanoburritos). This route can be extended to the synthesis of nanoburritos composed of other ultranarrow transition-metal chalcogenide nanoribbons and carbon nanotubes. The widths of previously synthesized MoS(2) ribbons are greater than 50 nm, while the encapsulated MoS(2) nanoribbons have uniform widths down to 1-4 nm and layer numbers down to 1-3, depending on the nanotube diameter. The edges of the MoS(2) nanoribbons have been identified as zigzag-shaped using both high-resolution transmission electron microscopy and density functional theory calculations. PMID:20828123

  12. Possibility of diacetyl and related compounds as the 4-carbon compound necessary for the formation of riboflavin in Ashbya gossypii.

    Science.gov (United States)

    Nakajima, K; Mitsuda, H

    1984-01-01

    The effects of various compounds (0.5%) involved in the butanediol and the glycolytic pathways on riboflavin formation in whole cells of Ashbya gossypii at rest were examined. The addition of acetate, glycerol and diacetyl inhibited riboflavin formation, while the addition of acetoin had no effect on it, and the addition of ethanol, 2,3-butanediol, pyruvic acid and glucose accelerated it. The relation of diacetyl and acetoin to riboflavin formation during resting cell incubation in the presence of 0.5% ethanol and various concentrations of 2,3-butanediol was examined. The results quantitatively revealed a precursor-product relation between riboflavin formation and the formation of diacetyl and acetoin. The results obtained provide evidence that a high flavinogenic agent, ethanol, was converted to acetaldehyde, pyruvic acid, acetoin and diacetyl in this order, that a week flavinogenic agent, 2,3-butanediol, was transferred to diacetyl through acetoin, and that the diacetyl produced can be utilized as the 4-carbon compound for riboflavin formation in the flavinogenic mold, Ashbya gossypii. It remains obscure whether diacetyl is enzymatically involved in riboflavin formation. PMID:6534171

  13. Copper inorganic-organic hybrid coordination compound as a novel L-cysteine electrochemical sensor: Synthesis, characterization, spectroscopy and crystal structure

    Indian Academy of Sciences (India)

    Zohreh Derikvand; Azadeh Azadbakht

    2015-11-01

    Dinuclear coordination compound of Cu(II), namely, [Cu2(pydc)2(pz)(H2O)2]·2H2O, where pydc = pyridine-2,6-dicarboxylic acid (dipicolinic acid) and pz = pyrazine has been synthesized and characterized by elemental analysis, spectra (IR, UV-Vis), thermal (TG/DTG) analysis, magnetic measurements and single crystal X-ray diffraction. In the dimeric structure, the planar tridentate pyridine-2,6-dicarboxylic acid dianion coordinates to a Cu(II) ion in a meridional fashion and defines the basal plane of the complex. The fourth equatorial coordination site is then occupied by a pyrazine molecule that functions as a linear bidentate ligand bridging two Cu(II) complexes to form a dimer. The axial positions of each Cu(II) complex are occupied by one water molecule to form a distorted square pyramidal geometry. The complicated hydrogen bonding network accompanied with C–O· · · and C–H· · · stacking interactions assemble the crystal structure of 1 into a fascinating supramolecular architecture. Electrochemical behavior of [Cu2(pydc)2(pz)(H2O)2] (Cu-PDAP) on the surface of carbon nanotube (CNTs) glassy carbon electrode (GCE) is described. Oxidation of cysteine on the surface of modified electrode was investigated with cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The results show that the Cu-PDAP/CNTs film displays excellent electrochemical catalytic activities towards L-cysteine oxidation.

  14. Catalytic Conversion of Carbon-Containing Compounds into Valuable Chemicals and Fuels

    Science.gov (United States)

    Cheng, Zhuo

    Conversion of carbon-containing compounds, especially C1 compounds such as carbon dioxide and methane, to valuable chemicals and fuels will hopefully address concerns over decreasing supplies of fossil fuels and mitigate the eects of greenhouse gas emissions on global climate change. Many challenges, however, remain to be addressed before these technologies may be adopted on an industrial scale. Chiefly, catalysts must be developed to activate carbon-containing compounds from their thermodynamically stable ground states, using hydrogen, electrons, or heat as energy sources. We chose as model catalytic systems: 1) Metathesis of ethene and 2-butene; 2) Methane dehydrogenation and carbon dioxide hydrogenation. We developed three computational methodologies to study these processes across a range of length and time scales. First, we investigated how electronic structure affects the properties and reactivity of these catalyst systems; by computing the partial electronic density of states, electronic localization function, and excess spin density, we showed how redox supports, such as ceria, promote electron transfer reactions. We applied this to the studies of methane activation and carbon dioxide activation. Second, we developed a non-equilibrium thermodynamics approach to calculate energies of activation at nite temperatures, based on the Bronsted-Evans-Polanyi principle and the Nudged Elastic Band method. Third, we developed an approach to numerically compute heat capacities and other thermodynamic properties on extended catalytic systems that are comparable in accuracy and precision to methods that have been well-developed for gas-phase molecules. We applied these to the studies of metathesis propagation and carbon dioxide hydrogenation. We gained mechanistic, thermodynamic, and kinetic insight into the elementary steps that comprise larger reaction networks of interest to the broader catalysis community. Ultimately, these theoretical and computational predictions

  15. Electrically Conductive Compounds of Polycarbonate, Liquid Crystalline Polymer, and Multiwalled Carbon Nanotubes

    OpenAIRE

    Penwisa Pisitsak; Rathanawan Magaraphan; Sadhan C. Jana

    2012-01-01

    A thermotropic liquid crystalline polymer (LCP) was blended with polycarbonate (PC) and multiwalled carbon nanotube (CNT) with the goal of improving electrical conductivity and mechanical properties over PC. The LCP was anticipated to produce fibrillar domains in PC and help improve the mechanical properties. The study was carried out using two grades of LCP—Vectra A950 (VA950) and Vectra V400P (V400P). The compounds contained 20 wt% LCP and 0.5 to 15 wt% CNT. The compounds were prepared by m...

  16. Utilizing Model Nanostructured Porous Inorganic Compounds Such as Silica to Beneficially Confine “Bio”-Relevant Molecules and Demonstrate their Potential in Therapeutics

    OpenAIRE

    Bhattacharyya, Aninda J; Mandal, Soumit S

    2011-01-01

    Abstract | The importance of well-defined inorganic porous nanostructured materials in the context of biotechnological applications such as drug delivery and biomolecular sensing is reviewed here in detail. Under optimized conditions, the confinement of “bio”-relevant molecules such as pharmaceutical drugs, enzymes or proteins inside such inorganic nanostructures may be remarkably beneficial leading to enhanced molecular stability, activity and performance. From the point of view of bas...

  17. Variation of photoautotrophic fatty acid production from a highly CO2 tolerant alga, Chlorococcum littorale, with inorganic carbon over narrow ranges of pH.

    Science.gov (United States)

    Ota, Masaki; Takenaka, Motohiro; Sato, Yoshiyuki; Smith, Richard L; Inomata, Hiroshi

    2015-01-01

    Photoautotrophic fatty acid production of a highly CO2 -tolerant green alga Chlorococcum littorale in the presence of inorganic carbon at 295 K and light intensity of 170 µmol-photon m(-2) s(-1) was investigated. CO2 concentration in the bubbling gas was adjusted by mixing pure gas components of CO2 and N2 to avoid photorespiration and β-oxidation of fatty acids under O2 surrounding conditions. Maximum content of total fatty acid showed pH-dependence after nitrate depletion of the culture media and increased with the corresponding inorganic carbon ratio. Namely, [HCO3 (-) ]/([CO2 ]+n[ CO32-]) ratio in the culture media was found to be a controlling factor for photoautotrophic fatty acid production after the nitrate limitation. At a CO2 concentration of 5% (vol/vol) and a pH of 6.7, the fatty acid content was 47.8 wt % (dry basis) at its maximum that is comparable with land plant seed oils. PMID:25919350

  18. Variability in carbon isotope fractionation of trichloroethene during degradation by persulfate activated with zero-valent iron: Effects of inorganic anions.

    Science.gov (United States)

    Liu, Yunde; Zhou, Aiguo; Gan, Yiqun; Li, Xiaoqian

    2016-04-01

    Stable carbon isotope analysis has the potential to be used for assessing the performance of in situ remediation of organic contaminants. Successful application of this isotope technique requires understanding the magnitude and variability in carbon isotope fractionation associated with the reactions under consideration. This study investigated the influence of inorganic anions (sulfate, bicarbonate, and chloride) on carbon isotope fractionation of trichloroethene (TCE) during its degradation by persulfate activated with zero-valent iron. The results demonstrated that the significant carbon isotope fractionation (enrichment factors ε ranging from -3.4±0.3 to -4.3±0.3‰) was independent on the zero-iron dosage, sulfate concentration, and bicarbonate concentration. However, the ε values (ranging from -7.0±0.4 to -13.6±1.2‰) were dependent on the chloride concentration, indicating that chloride could significantly affect carbon isotope fractionation during TCE degradation by persulfate activated with zero-valent iron. The dependence of ε values on chloride concentration, indicated that TCE degradation mechanisms may be different from the degradation mechanism caused by sulfate radical (SO4(-)). Ignoring the effect of chloride on ε value may cause numerous uncertainties in quantitative assessment of the performance of the in situ chemical oxidation (ISCO). PMID:26784392

  19. Are mangroves drivers or buffers of coastal acidification? Insights from alkalinity and dissolved inorganic carbon export estimates across a latitudinal transect

    Science.gov (United States)

    Sippo, James Z.; Maher, Damien T.; Tait, Douglas R.; Holloway, Ceylena; Santos, Isaac R.

    2016-05-01

    Mangrove forests are hot spots in the global carbon cycle, yet the fate for a majority of mangrove net primary production remains unaccounted for. The relative proportions of alkalinity and dissolved CO2 [CO2*] within the dissolved inorganic carbon (DIC) exported from mangroves is unknown, and therefore, the effect of mangrove DIC exports on coastal acidification remains unconstrained. Here we measured dissolved inorganic carbon parameters over complete tidal and diel cycles in six pristine mangrove tidal creeks covering a 26° latitudinal gradient in Australia and calculated the exchange of DIC, alkalinity, and [CO2*] between mangroves and the coastal ocean. We found a mean DIC export of 59 mmol m-2 d-1 across the six systems, ranging from import of 97 mmol m-2 d-1 to an export of 85 mmol m-2 d-1. If the Australian transect is representative of global mangroves, upscaling our estimates would result in global DIC exports of 3.6 ± 1.1 Tmol C yr-1, which accounts for approximately one third of the previously unaccounted for mangrove carbon sink. Alkalinity exchange ranged between an import of 1.2 mmol m-2 d-1 and an export of 117 mmol m-2 d-1 with an estimated global export of 4.2 ± 1.3 Tmol yr-1. A net import of free CO2 was estimated (-11.4 ± 14.8 mmol m-2 d-1) and was equivalent to approximately one third of the air-water CO2 flux (33.1 ± 6.3 mmol m-2 d-1). Overall, the effect of DIC and alkalinity exports created a measurable localized increase in coastal ocean pH. Therefore, mangroves may partially counteract coastal acidification in adjacent tropical waters.

  20. Organic carbon transformation in agricultural soils : radiocarbon analysis of organic matter fractions and biomarker compounds

    OpenAIRE

    Rethemeyer, Janet

    2004-01-01

    Radiocarbon analyses of physical and chemical soil organic matter fractions as well as of individual compounds provided information on the origin, transformation and stabilisation of organic carbon in agricultural soils. A contamination of the soil at the study site at Halle/Saale (Germany) with fossil, lignite-derived carbon was identified by high apparent 14C ages of the organic matter in the plough horizon of about 5000 years BP and a decrease in 14C age with increasing soil depth. The fos...

  1. Effects of uncertainties in the thermodynamic properties of aerosol components in an air quality model – Part I: Treatment of inorganic electrolytes and organic compounds in the condensed phase

    Directory of Open Access Journals (Sweden)

    J. H. Seinfeld

    2007-07-01

    Full Text Available Air quality models that generate the concentrations of semi-volatile and other condensable organic compounds using an explicit reaction mechanism require estimates of the physical and thermodynamic properties of the compounds that affect gas/aerosol partitioning: vapour pressure (as a subcooled liquid, and activity coefficients in the aerosol phase. The model of Griffin, Kleeman and co-workers (e.g., Griffin et al., 1999; Kleeman et al., 1999 assumes that aerosol particles consist of an aqueous phase, containing inorganic electrolytes and soluble organic compounds, and a hydrophobic phase containing mainly primary hydrocarbon material. Thirty eight semi-volatile reaction products are grouped into ten surrogate species which partition between the gas phase and both phases in the aerosol. Activity coefficients of the organic compounds are calculated using UNIFAC. In a companion paper (Clegg et al., 2007 we examine the likely uncertainties in the vapour pressures of the semi-volatile compounds and their effects on partitioning over a range of atmospheric relative humidities. In this work a simulation for the South Coast Air Basin surrounding Los Angeles, using lower vapour pressures of the semi-volatile surrogate compounds consistent with estimated uncertainties in the boiling points on which they are based, yields a doubling of the predicted 24-h average secondary organic aerosol concentrations. The dependency of organic compound partitioning on the treatment of inorganic electrolytes in the air quality model, and the performance of this component of the model, are determined by analysing the results of a trajectory calculation using an extended version of the Aerosol Inorganics Model of Wexler and Clegg (2002. Simplifications are identified where substantial efficiency gains can be made, principally: the omission of dissociation of the organic acid surrogates; restriction of aerosol organic compounds to one of the two phases (aqueous or

  2. Effects of uncertainties in the thermodynamic properties of aerosol components in an air quality model ─ Part 1: Treatment of inorganic electrolytes and organic compounds in the condensed phase

    Directory of Open Access Journals (Sweden)

    J. H. Seinfeld

    2008-02-01

    Full Text Available Air quality models that generate the concentrations of semi-volatile and other condensable organic compounds using an explicit reaction mechanism require estimates of the physical and thermodynamic properties of the compounds that affect gas/aerosol partitioning: vapour pressure (as a subcooled liquid, and activity coefficients in the aerosol phase. The model of Griffin, Kleeman and co-workers (e.g., Griffin et al., 2003; Kleeman et al., 1999 assumes that aerosol particles consist of an aqueous phase, containing inorganic electrolytes and soluble organic compounds, and a hydrophobic phase containing mainly primary hydrocarbon material. Thirty eight semi-volatile reaction products are grouped into ten surrogate species which partition between the gas phase and both phases in the aerosol. Activity coefficients of the organic compounds are calculated using UNIFAC. In a companion paper (Clegg et al., 2008 we examine the likely uncertainties in the vapour pressures of the semi-volatile compounds and their effects on partitioning over a range of atmospheric relative humidities. In this work a simulation for the South Coast Air Basin surrounding Los Angeles, using lower vapour pressures of the semi-volatile surrogate compounds consistent with estimated uncertainties in the boiling points on which they are based, yields a doubling of the predicted 24-h average secondary organic aerosol concentrations. The dependency of organic compound partitioning on the treatment of inorganic electrolytes in the air quality model, and the performance of this component of the model, are determined by analysing the results of a trajectory calculation using an extended version of the Aerosol Inorganics Model of Wexler and Clegg (2002. Simplifications are identified where substantial efficiency gains can be made, principally: the omission of dissociation of the organic acid surrogates; restriction of aerosol organic compounds to one of the two phases (aqueous or

  3. Carbon compound used in hydrogen storage; Compuesto de carbon utilizado en almacenamiento de hidrogeno

    Energy Technology Data Exchange (ETDEWEB)

    Iturbe G, J.L.; Lopez M, B.E. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2004-07-01

    In the present work it is studied the activated carbon of mineral origin for the sorption of hydrogen. The carbon decreased of particle size by means of the one alloyed mechanical. The time of mill was of 10 hours. The characterization one carries out by scanning electron microscopy and X-ray diffraction. The hydrogen sipped in the carbon material it was determined using the Thermal gravimetric method (TGA). The conditions of hydrogenation went at 10 atm of pressure and ambient temperature during 18 hours. They were also carried out absorption/desorption cycles of hydrogen in the same one system of thermal gravimetric analysis. The results showed percentages of sorption of 2% approximately in the cycles carried out in the system TGA and of 4.5% in weight of hydrogen at pressure of 10 atmospheres and ambient temperature during 18 hours. (Author)

  4. Carbon functionalized mesoporous silica-based gas sensors for indoor volatile organic compounds.

    Science.gov (United States)

    Liu, Yupu; Chen, Junchen; Li, Wei; Shen, Dengke; Zhao, Yujuan; Pal, Manas; Yu, Haijun; Tu, Bo; Zhao, Dongyuan

    2016-09-01

    Indoor organic gaseous pollution is a global health problem, which seriously threats the health and life of human all over the world. Hence, it is important to fabricate new sensing materials with high sensitivity and efficiency for indoor volatile organic compounds. In this study, a series of ordered mesoporous silica-based nanocomposites with uniform carbon coatings on the internal surface of silica mesopore channels were synthesized through a simple template-carbonization strategy. The obtained mesoporous silica-carbon nanocomposites not only possess ordered mesostructures, high surface areas (up to ∼759m(2)g(-1)), large and tunable pore sizes (2.6-10.2nm), but also have the improved hydrophobicity and anti-interference capability to environmental humidity. The sensing performances of the mesoporous silica-carbon nanocomposites to volatile organic compounds, such as ethylbenzene, methylbenzene, benzene, methanol, acetone, formaldehyde, dichloromethane and tetrahydrofuran, were systematically investigated. The relationships between the sensing performances and their properties, including mesostructures, surface areas, pore sizes, carbon contents and surface hydrophilic/hydrophobic interactions, have been achieved. The mesoporous silica-carbon nanocomposites with hexagonal mesostructure exhibit outstanding performance at room temperature to benzene and acetone with high responses, short response (2-3s) and recovery (16-19s) time, strong anti-interference to environmental humidity, and long-term stability (less than ∼5% loss of the frequency shifts after 42days). Therefore, the obtained mesoporous silica-carbon nanocomposites have a hopeful prospect in the field of environmental air quality monitoring. PMID:27240244

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

    Science.gov (United States)

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

    2014-05-01

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

  6. O-methylation of natural phenolic compounds based on green chemistry using dimethyl carbonate

    Science.gov (United States)

    Prakoso, N. I.; Pangestu, P. H.; Wahyuningsih, T. D.

    2016-02-01

    The alkyl aryl ether compounds, of which methyl eugenol and veratraldehyde are the simplest intermediates can be synthesized by reacting eugenol and vanillin with the green reagent dimethyl carbonate (DMC). The reaction was carried out under mild of temperature and pressure. Excellent yields and selective products were obtained (95-96%) after a few hours. In the end of the reaction, the catalysts (base and Phase Transfer Catalyst) can be recovered and regenerated.

  7. Angle-Dependent Electron Spectroscopy Studies of C60 Compounds and Carbon Nanotubes

    OpenAIRE

    Schiessling, Joachim

    2003-01-01

    Fullerenes have been shown to constitute a prototypical building block for truly nanometer-sized devices and exotic nanounit-based materials, e.g., high-temperature superconductors. This makes the detailed understanding of fullerene electronic states in compounds and at interfaces of primary importance, since the high symmetry of the molecule greatly simplifies the starting point of the analysis. Carbon nanotubes, which combine one macroscopic with two nanoscopic dimensions, are perhaps of e...

  8. Supercritical Carbon Dioxide Extraction of Bioactive Compounds from Ampelopsis grossedentata Stems: Process Optimization and Antioxidant Activity

    OpenAIRE

    Da Sun; Shikang Zhang; Yuefei Wang; Ping Xu; Yuejin Zhu; Le Ying

    2011-01-01

    Supercritical carbon dioxide (SC-CO2) extraction of bioactive compounds including flavonoids and phenolics from Ampelopsis grossedentata stems was carried out. Extraction parameters such as pressure, temperature, dynamic time and modifier, were optimized using an orthogonal array design of L9 (34), and antioxidant activities of the extracts were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and ferrous ion chelating (FIC) assay. The best conditions obtained f...

  9. Impact of the addition of a compound fertilizer on the dissolution of carbonate rock tablets: A column experiment

    International Nuclear Information System (INIS)

    Highlights: → Impact of compound fertilizer on carbonate dissolution is studied by columns. → Compound fertilizer reduced soil pH and increased the leach of ions. → Carbonate dissolution accelerated due to compound fertilizer application. → Impact of fertilizer on the budget of CO2 sink cannot be disregarded. - Abstract: The chemical weathering dynamics of carbonate and the C cycle are strongly influenced by anthropogenic perturbations such as agricultural fertilization. In this study, two columns (a control column and a fertilizer column) with carbonate rock tablets in the bottom of each were established to explore the impact of the addition of a compound fertilizer on the dissolution of carbonate rock tablets. The impacts were assessed from hydro-chemical analyses of the leachates from the two columns and comparison of the amount of dissolution of the carbonate rock tablets. The results showed that NH4+, free CO2, HCO3-,HPO42- and COD increased in the leachate after addition of the compound fertilizer, whereas the pH decreased. The pH decrease was attributed to the release of protons from the nitrification reaction. The amount of dissolution of limestone and dolomite tablets decreased as a result of the compound fertilizer application. Furthermore, the calculated results using Phreeqci software showed that the compound fertilizer reduced the saturation index of calcite and dolomite. Thus, the impact of a compound fertilizer, especially an ammonium fertilizer, on the budget of the CO2 sink cannot be disregarded on either a regional or a global scale.

  10. The effect of biological activity, CaCO3 mineral dynamics, and CO2 degassing in the inorganic carbon cycle in sea ice in late winter-early spring in the Weddell Sea, Antarctica

    Science.gov (United States)

    Papadimitriou, S.; Kennedy, H.; Norman, L.; Kennedy, D. P.; Dieckmann, G. S.; Thomas, D. N.

    A large-scale geographical study of the ice pack in the seasonal ice zone of the Weddell Sea, Antarctica, took place from September to October 2006. Sea ice brines with a salinity greater than 58 and temperature lower than -3.6°C were sampled from 22 ice stations. The brines had large deficits in total alkalinity and in the concentrations of the major dissolved macronutrients (total dissolved inorganic carbon, nitrate, and soluble reactive phosphorus) relative to their concentrations in the surface oceanic water and conservative behavior during seawater freezing. The concentration deficits were related to the dissolved inorganic carbon-consuming processes of photosynthesis, CaCO3 precipitation, and CO2 degassing. The largest concentration deficits in total dissolved inorganic carbon were found to be associated with CaCO3 precipitation and CO2 degassing, because the magnitude of the photosynthesis-induced concentration deficit in total dissolved inorganic carbon is controlled by the size of the inorganic nutrient pool, which can be limited in sea ice by its openness to exchange with the surrounding oceanic water.

  11. Adsorption of Thiophenic Compounds from Model Diesel Fuel Using Copper and Nickel Impregnated Activated Carbons

    Directory of Open Access Journals (Sweden)

    Ramin Karimzadeh

    2012-10-01

    Full Text Available Adsorption of sulfur compoundsby porous materials is an effective way to produce cleaner diesel fuel.In this study, adsorption of refractory thiophenic sulfur compounds, i.e., benzothiophene (BT, dibenzothiophene (DBT, and 4,6-dimethyldibenzothiophene (4,6-DMDBT in single-solute systems from n-hexane solutions onto metal-impregnated activated carbons was investigated. A hydrogen-treated activated carbon fiber was selectively loaded with Ni, NiO, Cu, Cu2O, and CuO species to systematically assess the impact of each metal species on the adsorption of thiophenic compounds (TC. Metal-loaded adsorbents had the same total metal contents and similar microporosities, but contained different types of copper or nickel species. All metal-loaded adsorbents showed enhanced adsorption of tested TC. Cu2O- or NiO-loaded adsorbents exhibited the highest uptakes, due to more specific interactions between Cu+ or Ni2+ species and TC molecules. The theoretical monolyer coverage of TC on the exposed Cu+ sites was estimated and compared with that calculated from the experimental data. Results suggested catalytic conversion of TC molecules to other compounds on the Cu+ sites, followed by adsorption of reaction products onto the carbon surface or multilayer accumulation of TC molecules on the Cu+sites. TC adsorption uptake of the majority of adsorbents followed the order of: 4,6-DMDBT > DBT > BT due to higher intensity of specific and non-specific interactions of larger TC molecules with adsorbents.

  12. Visualizing lone pairs in compounds containing heavier congeners of the carbon and nitrogen group elements

    Indian Academy of Sciences (India)

    Ram Seshadri

    2001-10-01

    In this mini-review, I discuss some recent work on the stereochemistry and bonding of lone pairs of electrons in divalent compounds of the heavier carbon group elements (SnII, PbII) and in trivalent compounds of the heavier nitrogen group elements (BiIII). Recently developed methods that permit the real-space visualization of bonding patterns on the basis of density functional calculations of electronic structure, reveal details of the nature of selectron lone pairs in compounds of the heavier main group elements - their stereochemistry and their inertness (or lack thereof). An examination of tetragonal 4/ SnO, -PbO and BiOF, and cubic $\\bar{3}$ PbS provides a segue into perovskite phases of technological significance, including ferroelectric PbTiO3 and antiferroelectric/piezoelectric PbZrO3, in both of which the lone pairs on Pb atoms play a pivotal rôle.

  13. Evaluation of Toxicological Effects of an Aqueous Extract of Shells from the Pecan Nut Carya illinoinensis (Wangenh.) K. Koch and the Possible Association with Its Inorganic Constituents and Major Phenolic Compounds

    Science.gov (United States)

    Porto, Luiz Carlos S.; Sousa, Karen; Ambrozio, Mariana L.; de Almeida, Aline; dos Santos, Carla Eliete I.; Dias, Johnny F.; Allgayer, Mariangela C.; dos Santos, Marcela S.; Pereira, Patrícia; Picada, Jaqueline N.

    2016-01-01

    Background. Industrial processing of the pecan nut Carya illinoinensis K. Koch generated a large amount of shells, which have been used to prepare nutritional supplements and medicinal products; however, the safe use of shells requires assessment. This study evaluated the toxic, genotoxic, and mutagenic effects of pecan shell aqueous extract (PSAE) and the possible contribution of phenolic compounds, ellagic and gallic acids, and inorganic elements present in PSAE to induce toxicity. Results. Levels of inorganic elements like K, P, Cl, and Rb quantified using the Particle-Induced X-Ray Emission method were higher in PSAE than in pecan shells, while Mg and Mn levels were higher in shells. Mice showed neurobehavioral toxicity when given high PSAE doses (200–2,000 mg kg−1). The LD50 was 1,166.3 mg kg−1. However, PSAE (50–200 mg·kg−1) and the phenolic compounds (10–100 mg·kg−1) did not induce DNA damage or mutagenicity evaluated using the comet assay and micronucleus test. Treatment with ellagic acid (10–100 mg·kg−1) decreased triglyceride and glucose levels, while treatments with PSAE and gallic acid had no effect. Conclusion. Pecan shell toxicity might be associated with high concentrations of inorganic elements such as Mn, Al, Cu, and Fe acting on the central nervous system, besides phytochemical components, suggesting that the definition of the safe dose should take into account the consumption of micronutrients. PMID:27525021

  14. The electrochemical performance of ordered mesoporous carbon/nickel compounds composite material for supercapacitor

    International Nuclear Information System (INIS)

    A series of high performance ordered mesoporous carbon/nickel compounds composites have been synthesized by a combination of incipient wetness impregnation and hydrothermal method for the first time. X-ray diffraction (XRD), N2 adsorption/desorption isotherms and transmission electron microscopy (TEM) are used to characterize the composites derived at the hydrothermal temperature of 125, 150, 175, 200, 250, 275 and 300 oC. The formation of nanosized nickel compounds, fully inside the mesopore system, was confirmed with XRD and TEM. An N2 adsorption/desorption isotherms measurements still revealed mesoporosity for the host/guest compounds. It is noteworthy that an OMC/nickel nitrate hydroxide hydrate composite (OMCN-150) exhibits more excellent performance. Based on the various hydrothermal temperatures of the composite, the capacitance of an OMCN-150 delivering the best electrochemical performance is about 2.4 (5 mV s-1) and 1.5 (50 mV s-1) times of the pristine OMC. The capacitance retention of an OMCN-150 is 96.1%, which indicates that the electrochemical performance of the supercapacitor is improved greatly, and represents novel research and significant advances in the field of electrode composite materials for supercapacitor. -- Graphical abstract: A series of high performance nickel compound/ordered mesoporous carbon composites were synthesized by a combination of incipient wetness impregnation and hydrothermal method for the first time. Display Omitted

  15. Single, competitive, and dynamic adsorption on activated carbon of compounds used as plasticizers and herbicides.

    Science.gov (United States)

    Abdel daiem, Mahmoud M; Rivera-Utrilla, José; Sánchez-Polo, Manuel; Ocampo-Pérez, Raúl

    2015-12-15

    The main aim of this study was to investigate the single, competitive, and dynamic adsorption of phthalic acid (PA), bisphenol A (BPA), diphenolic acid (DPA), 2,4-dichlorophenoxy-acetic acid (2,4-D), and 4-chloro-2-methylphenoxyacetic acid (MCPA) on two activated carbons with different chemical natures and similar textural characteristics. The adsorption mechanism was also elucidated by analyzing the influence of solution pH and ionic strength. The activated carbons demonstrated high adsorption capacity to remove all micropollutants due to the presence of active sites on their surfaces, which increase dispersive interactions between the activated carbon graphene layers and the aromatic ring of pollutants. The adsorption capacity of the activated carbons increased in the order: DPAcarbon decreased by around 50% and 70% in the presence of DPA and BPA, respectively, indicating that both compounds are adsorbed on the same adsorption sites of the activated carbon. PMID:26282767

  16. Evolution of chemical and isotopic composition of inorganic carbon in a complex semi-arid zone environment: Consequences for groundwater dating using radiocarbon

    Science.gov (United States)

    Meredith, K. T.; Han, L. F.; Hollins, S. E.; Cendón, D. I.; Jacobsen, G. E.; Baker, A.

    2016-09-01

    Estimating groundwater age is important for any groundwater resource assessment and radiocarbon (14C) dating of dissolved inorganic carbon (DIC) can provide this information. In semi-arid zone (i.e. water-limited environments), there are a multitude of reasons why 14C dating of groundwater and traditional correction models may not be directly transferable. Some include; (1) the complex hydrological responses of these systems that lead to a mixture of different ages in the aquifer(s), (2) the varied sources, origins and ages of organic matter in the unsaturated zone and (3) high evaporation rates. These all influence the evolution of DIC and are not easily accounted for in traditional correction models. In this study, we determined carbon isotope data for; DIC in water, carbonate minerals in the sediments, sediment organic matter, soil gas CO2 from the unsaturated zone, and vegetation samples. The samples were collected after an extended drought, and again after a flood event, to capture the evolution of DIC after varying hydrological regimes. A graphical method (Han et al., 2012) was applied for interpretation of the carbon geochemical and isotopic data. Simple forward mass-balance modelling was carried out on key geochemical processes involving carbon and agreed well with observed data. High values of DIC and δ13CDIC, and low 14CDIC could not be explained by a simple carbonate mineral-CO2 gas dissolution process. Instead it is suggested that during extended drought, water-sediment interaction leads to ion exchange processes within the top ∼10-20 m of the aquifer which promotes greater calcite dissolution in saline groundwater. This process was found to contribute more than half of the DIC, which is from a mostly 'dead' carbon source. DIC is also influenced by carbon exchange between DIC in water and carbonate minerals found in the top 2 m of the unsaturated zone. This process occurs because of repeated dissolution/precipitation of carbonate that is dependent on

  17. Coupling the chemical dynamics of carbonate and dissolved inorganic nitrogen systems in the eutrophic and turbid inner Changjiang (Yangtze River) Estuary

    Science.gov (United States)

    Zhai, W.-D.; Yan, X.-L.

    2015-04-01

    To better understand biogeochemical processes controlling CO2 dynamics in those eutrophic large-river estuaries and coastal lagoons, we investigated surface water carbonate system, nutrients, and relevant hydrochemical parameters in the inner Changjiang (Yangtze River) Estuary, covering its channel-like South Branch and the lagoon-like North Branch, shortly after a spring-tide period in April 2010. In the North Branch, with a water residence time of more than 2 months, biogeochemical additions of ammonium (7.4 to 65.7 μmol kg-1) and alkalinity (196 to 695 μmol kg-1) were detected along with high salinity of 4.5 to 17.4. In the South Branch upper-reach, unusual salinity values of 0.20 to 0.67 were detected, indicating spillover waters from the North Branch. The spillover waters enhanced the springtime Changjiang export fluxes of nutrients, dissolved inorganic carbon, and alkalinity. And they affected the biogeochemistry in the South Branch, by lowering water-to-air CO2 flux and continuing the nitrification reaction. In the North Branch, pCO2 was measured from 930 to 1518 μatm at the salinity range between 8 and 16, which was substantially higher than the South Branch pCO2 of 700 to 1100 μatm. Based on field data analyses and simplified stoichiometric equations, we suggest that the North Branch CO2 productions were quantified by biogeochemical processes combining organic matter decomposition, nitrification, CaCO3 dissolution, and acid-base reactions in the estuarine mixing zone. Although our study is subject to limited temporal and spatial coverage of sampling, we have demonstrated a procedure to quantificationally constrain net CO2 productions in eutrophic estuaries and/or coastal lagoons, by coupling the chemical dynamics of carbonate and dissolved inorganic nitrogen systems.

  18. A flow injection analyser conductometric coupled system for the field analysis of free dissolved CO2 and total dissolved inorganic carbon in natural waters.

    Science.gov (United States)

    Martinotti, Valter; Balordi, Marcella; Ciceri, Giovanni

    2012-05-01

    A flow injection analyser coupled with a gas diffusion membrane and a conductometric microdetector was adapted for the field analysis of natural concentrations of free dissolved CO2 and dissolved inorganic carbon in natural waters and used in a number of field campaigns for marine water monitoring. The dissolved gaseous CO2 presents naturally, or that generated by acidification of the sample, is separated by diffusion using a hydrophobic semipermeable gas porous membrane, and the permeating gas is incorporated into a stream of deionised water and measured by means of an electrical conductometric microdetector. In order to make the system suitable and easy to use for in-field measurements aboard oceanographic ships, the single components of the analyser were compacted into a robust and easy to use system. The calibration of the system is carried out by using standard solutions of potassium bicarbonate at two concentration ranges. Calibration and sample measurements are carried out inside a temperature-constant chamber at 25 °C and in an inert atmosphere (N2). The detection and quantification limits of the method, evaluated as 3 and 10 times the standard deviation of a series of measurements of the matrix solution were 2.9 and 9.6 μmol/kg of CO2, respectively. Data quality for dissolved inorganic carbon was checked with replicate measurements of a certified reference material (A. Dickson, Scripps Institution of Oceanography, University of California, San Diego), both accuracy and repeatability were -3.3% and 10%, respectively. Optimization, performance qualification of the system and its application in various natural water samples are reported and discussed. In the future, the calibration step will be operated automatically in order to improve the analytical performance and the applicability will be increased in the course of experimental surveys carried out both in marine and freshwater ecosystems. Considering the present stage of development of the method, it

  19. Coupling the chemical dynamics of carbonate and dissolved inorganic nitrogen systems in the eutrophic and turbid inner Changjiang (Yangtze River Estuary

    Directory of Open Access Journals (Sweden)

    W.-D. Zhai

    2015-04-01

    Full Text Available To better understand biogeochemical processes controlling CO2 dynamics in those eutrophic large-river estuaries and coastal lagoons, we investigated surface water carbonate system, nutrients, and relevant hydrochemical parameters in the inner Changjiang (Yangtze River Estuary, covering its channel-like South Branch and the lagoon-like North Branch, shortly after a spring-tide period in April 2010. In the North Branch, with a water residence time of more than 2 months, biogeochemical additions of ammonium (7.4 to 65.7 μmol kg−1 and alkalinity (196 to 695 μmol kg−1 were detected along with high salinity of 4.5 to 17.4. In the South Branch upper-reach, unusual salinity values of 0.20 to 0.67 were detected, indicating spillover waters from the North Branch. The spillover waters enhanced the springtime Changjiang export fluxes of nutrients, dissolved inorganic carbon, and alkalinity. And they affected the biogeochemistry in the South Branch, by lowering water-to-air CO2 flux and continuing the nitrification reaction. In the North Branch, pCO2 was measured from 930 to 1518 μatm at the salinity range between 8 and 16, which was substantially higher than the South Branch pCO2 of 700 to 1100 μatm. Based on field data analyses and simplified stoichiometric equations, we suggest that the North Branch CO2 productions were quantified by biogeochemical processes combining organic matter decomposition, nitrification, CaCO3 dissolution, and acid-base reactions in the estuarine mixing zone. Although our study is subject to limited temporal and spatial coverage of sampling, we have demonstrated a procedure to quantificationally constrain net CO2 productions in eutrophic estuaries and/or coastal lagoons, by coupling the chemical dynamics of carbonate and dissolved inorganic nitrogen systems.

  20. Synthesis, alignment, growth mechanism and functional properties of carbon nanotubes and their hybrid materials with inorganic and biomaterials

    OpenAIRE

    Joshi, Ravi

    2010-01-01

    The present work comprises a novel method for selective growth of carbon nanotubes, study of their growth mechanism as well as synthesis and application of their various hybrid materials. An experimental setup is established to grow carbon nanotubes using water assisted chemical vapor deposition method. Various growth parameters were scrutinized carefully and a growth mechanism is put forth for the same method. A new methodology to prepare different hybrid materials of aligned carbon nanotube...

  1. Effects of Long Term Application of Inorganic and Organic Fertilizers on Soil Organic Carbon and Physical Properties in Maize–Wheat Rotation

    Directory of Open Access Journals (Sweden)

    Babbu Singh Brar

    2015-06-01

    Full Text Available Balanced and integrated use of organic and inorganic fertilizers may enhance the accumulation of soil organic matter and improves soil physical properties. A field experiment having randomized complete block design with four replications was conducted for 36 years at Punjab Agricultural University (PAU, Ludhiana, India to assess the effects of inorganic fertilizers and farmyard manure (FYM on soil organic carbon (SOC, soil physical properties and crop yields in a maize (Zea mays–wheat (Triticum aestivum rotation. Soil fertility management treatments included were non-treated control, 100% N, 50% NPK, 100% NP, 100% NPK, 150% NPK, 100% NPK + Zn, 100% NPK + W, 100% NPK (-S and 100% NPK + FYM. Soil pH, bulk density (BD, electrical conductivity (EC, cation exchange capacity, aggregate mean weight diameter (MWD and infiltration were measured 36 years after the initiation of experiment. Cumulative infiltration, infiltration rate and aggregate MWD were greater with integrated use of FYM along with 100% NPK compared to non-treated control. No significant differences were obtained among fertilizer treatments for BD and EC. The SOC pool was the lowest in control at 7.3 Mg ha−1 and increased to 11.6 Mg ha−1 with 100%NPK+FYM. Improved soil physical conditions and increase in SOC resulted in higher maize and wheat yields. Infiltration rate, aggregate MWD and crop yields were positively correlated with SOC. Continuous cropping and integrated use of organic and inorganic fertilizers increased soil C sequestration and crop yields. Balanced application of NPK fertilizers with FYM was best option for higher crop yields in maize–wheat rotation.

  2. Steam reforming of cyclic model compounds of bio-oil over Ni-based catalysts: Product distribution and carbon formation

    DEFF Research Database (Denmark)

    Trane-Restrup, Rasmus; Jensen, Anker Degn

    2015-01-01

    significantly by adding oxygen to the feed at a cost of a lower yield of H2. Stable operation was observed initially (first 4h) in the OSR of all compounds, but experiments over 24h showed signs of deactivation due to an accelerated rate of carbon deposition in the SR of furfural and guaiacol. Furthermore...... yields in the SR of guaiacol and temperatures of 780°C were needed to totally convert guaiacol to carbon oxides and H2.Carbon deposition was observed in the SR of all three model compounds and was most severe for guaiacol followed by furfural and 2-methylfuran. The carbon deposition could be reduced...

  3. Biological and geochemical controls on diel dissolved inorganic carbon cycling in a low-order agricultural stream: Implications for reach scales and beyond

    Science.gov (United States)

    Tobias, C.; Böhlke, J.K.

    2011-01-01

    Movement of dissolved inorganic carbon (DIC) through the hydrologic cycle is an important component of global carbon budgets, but there is considerable uncertainty about the controls of DIC transmission from landscapes to streams, and through river networks to the oceans. In this study, diel measurements of DIC, ??13C-DIC, dissolved oxygen (O2), ??18O-O2, alkalinity, pH, and other parameters were used to assess the relative magnitudes of biological and geochemical controls on DIC cycling and flux in a nutrient-rich, net autotrophic stream. Rates of photosynthesis (P), respiration (R), groundwater discharge, air-water exchange of CO2, and carbonate precipitation/dissolution were quantified through a time-stepping chemical/isotope (12C and 13C, 16O and 18O) mass balance model. Groundwater was the major source of DIC to the stream. Primary production and carbonate precipitation were equally important sinks for DIC removed from the water column. The stream was always super-saturated with respect to carbonate minerals, but carbonate precipitation occurred mainly during the day when P increased pH. We estimated more than half (possibly 90%) of the carbonate precipitated during the day was retained in the reach under steady baseflow conditions. The amount of DIC removed from the overlying water through carbonate precipitation was similar to the amount of DIC generated from R. Air-water exchange of CO2 was always from the stream to the atmosphere, but was the smallest component of the DIC budget. Overall, the in-stream DIC reactions reduced the amount of CO2 evasion and the downstream flux of groundwater-derived DIC by about half relative to a hypothetical scenario with groundwater discharge only. Other streams with similar characteristics are widely distributed in the major river basins of North America. Data from USGS water quality monitoring networks from the 1960s to the 1990s indicated that 40% of 652 stream monitoring stations in the contiguous USA were at or above

  4. Sorption of organic carbon compounds to the fine fraction of surface and Subsurface Soils

    Energy Technology Data Exchange (ETDEWEB)

    Jagadamma, Sindhu [ORNL; Mayes, Melanie [ORNL; Zinn, Yuri [Federal University of Lavras, Brazil; Gisladottir, Gudrun [University of Iceland; Ann, Russell [Iowa State University

    2014-01-01

    Dissolved organic carbon (DOC) transported from the soil surface is stabilized in deeper soil profiles by physicochemical sorption processes. However, it is unclear how different forms of organic carbon (OC) compounds common in soil organic matter interact with soil minerals in the surface (A) and subsurface (B) horizons. We added four compounds (glucose, starch, cinnamic acid and stearic acid) to the silt- and clay-sized fraction (fine fraction) of A and B horizons of eight soils from varying climates (3 temperate, 3 tropical, 1 arctic and 1 sub-arctic). Equilibriumbatch experiments were conducted using 0 to 100 mg C L 1 of 14C-labeled compounds for 8 h. Sorption parameters (maximum sorption capacity, Qmax and binding coefficient, k) calculated by fitting sorption data to the Langmuir equation showed that Qmax of A and B horizons was very similar for all compounds. Both Qmax and k values were related to sorbate properties, with Qmax being lowest for glucose (20 500 mg kg 1), highest for stearic acid (20,000 200,000 mg kg 1), and intermediate for both cinnamic acid (200 4000 mg kg 1) and starch (400 6000 mg kg 1). Simple linear regression analysis revealed that physicochemical properties of the sorbents influenced the Qmax of cinnamic acid and stearic acid, but not glucose and starch. The sorbent properties did not show predictive ability for binding coefficient k. By using the fine fraction as sorbent, we found that the mineral fractions of A horizons are equally reactive as the B horizons irrespective of soil organic carbon content.

  5. 2007 Inorganic Reaction Mechanisms Gordon Research Conference-February 18-23

    Energy Technology Data Exchange (ETDEWEB)

    Andreja Bakac

    2008-01-01

    This conference focuses on kinetic, mechanistic, and thermodynamic studies of reactions that play a role in fields as diverse as catalysis, energy, bioinorganic chemistry, green chemistry, organometallics, and activation of small molecules (oxygen, nitrogen, carbon monoxide, carbon dioxide, alkanes). Participants from universities, industry, and national laboratories present results and engage in discussions of pathways, intermediates, and outcome of various reactions of inorganic, organic, coordination, organometallic, and biological species. This knowledge is essential for rational development and design of novel reactions, compounds, and catalysts.

  6. Inorganic Fullerene-Like Nanoparticles and Inorganic Nanotubes

    Directory of Open Access Journals (Sweden)

    Reshef Tenne

    2014-11-01

    Full Text Available Fullerene-like nanoparticles (inorganic fullerenes; IF and nanotubes of inorganic layered compounds (inorganic nanotubes; INT combine low dimensionality and nanosize, enhancing the performance of corresponding bulk counterparts in their already known applications, as well as opening new fields of their own [1]. This issue gathers articles from the diverse area of materials science and is devoted to fullerene-like nanoparticles and nanotubes of layered sulfides and boron nitride and collects the most current results obtained at the interface between fundamental research and engineering.[...

  7. Supramolecular gels from lipopeptide gelators: template improvement and strategies for the in-situ preparation of inorganic nanomaterials and for the dispersion of carbon nanomaterials.

    Science.gov (United States)

    Delbecq, Frederic

    2014-07-01

    Lipopeptide amphiphiles are an important class of biobased and biomimetic surfactants that are easily prepared from the cheapest organic reagents, such as natural fatty and amino acids, and in many cases, the resulting compounds are able to harden not only common organic solvents but also waxes, water and ionic liquids. Well-tailored, these gelators can be selective for one variety of liquid, which leads to the formation of a robust gel that is able to incorporate various different elements. In this review, we attempted to provide our opinion regarding the molecular design of the lipopeptide gelator candidates. In addition, we summarized each type of element that is necessary for creating potent supramolecular gel templates that are useful for inorganic nano- and micro-material preparation. This review is not only limited to recent papers found in the literature; a portion of our unpublished results are also provided as a supplement to illustrate our point of view regarding this subject. PMID:24630345

  8. Inorganic Constituents in Coal

    OpenAIRE

    Rađenović A.

    2006-01-01

    Coal contains not only organic matter but also small amounts of inorganic constituents. More thanone hundred different minerals and virtually every element in the periodic table have been foundin coal. Commonly found group minerals in coal are: major (quartz, pyrite, clays and carbonates),minor, and trace minerals. Coal includes a lot of elements of low mass fraction of the orderof w=0.01 or 0.001 %. They are trace elements connected with organic matter or minerals comprisedin coal. The fract...

  9. Emissions of carbon species, organic polar compounds, potassium, and mercury from prescribed burning activities

    Science.gov (United States)

    Zhang, Y.; Obrist, D.; Zielinska, B.; Gerler, A.

    2012-04-01

    Biomass burning is an important emission source of pollutants to the atmosphere, but few studies have focused on the chemical composition of emissions from prescribed burning activities. Here we present results from a sampling campaign to quantify particulate-phase emissions from various types of prescribed fires including carbon species (Elemental Carbon: EC; Organic Carbon: OC; and Total Carbon: TC); polar organic compounds (12 different compounds and four functional classes); water-soluble potassium (K+); and mercury (Hg). We measured emissions from the following types of prescribed biomass burning in the Lake Tahoe basin located on the California/Nevada border: (i) log piles stacked and dried in the field; (ii) log piles along with green understory vegetation; and (iii) understory green vegetation and surface litter; further emissions were collected from burns conducted in a wood stove: (iv) dried wooden logs; (v) green foliage of understory vegetation collected from the field; and (vi) surface organic litter collected from the field; finally, samples were also taken from (vii) ambient air in residential areas during peak domestic wood combustion season. Results show that OC/EC ratios of prescribed burns in the field ranged from 4 to 10, but lower values (around 1) were observed in controlled stove fires. These results are consistent with an excess of OC emissions over EC found in wildfires. OC/EC ratios, however, showed clear separations between controlled wood stove combustion (higher EC) and prescribed burns in the field (lower EC). We attribute this difference to a higher combustion temperatures and dominance of flaming combustion in wood stove fires. OC positively and linearly correlated to the sum of polar organic compounds across all burn types (r2 of 0.82). The most prevalent group of polar compounds emitted during prescribed fires was resin acids (dehydroabietic, pimaric, and abietic acids), followed by levoglucosan plus mannositol. Negligible

  10. Kinetic characteristics and modeling of microalgae Chlorella vulgaris growth and CO2 biofixation considering the coupled effects of light intensity and dissolved inorganic carbon.

    Science.gov (United States)

    Chang, Hai-Xing; Huang, Yun; Fu, Qian; Liao, Qiang; Zhu, Xun

    2016-04-01

    Understanding and optimizing the microalgae growth process is an essential prerequisite for effective CO2 capture using microalgae in photobioreactors. In this study, the kinetic characteristics of microalgae Chlorella vulgaris growth in response to light intensity and dissolved inorganic carbon (DIC) concentration were investigated. The greatest values of maximum biomass concentration (Xmax) and maximum specific growth rate (μmax) were obtained as 2.303gL(-1) and 0.078h(-1), respectively, at a light intensity of 120μmolm(-2)s(-1) and DIC concentration of 17mM. Based on the results, mathematical models describing the coupled effects of light intensity and DIC concentration on microalgae growth and CO2 biofixation are proposed. The models are able to predict the temporal evolution of C. vulgaris growth and CO2 biofixation rates from lag to stationary phases. Verification experiments confirmed that the model predictions agreed well with the experimental results. PMID:26866758

  11. The Effects of Silica/Carbon Black Ratio on the Dynamic Properties of the Tread compounds in Truck Tires

    OpenAIRE

    Zafarmehrabian, Ramin; Gangali, Saeed Taghvaei; Ghoreishy, Mir Hamid Reza; Davallu, Mehran

    2012-01-01

    NR is the major constituent in the rubber compound used for the tread on the truck tires. A general compound formulation of the tire tread includes NR and BR as polymer base and carbon black as the reinforcing filler, and curative components. In this paper the effects of dual filler system (carbon black and precipitated silica) on the dynamic properties of tire treat has been studied. The results show by increasing of precipitated silica, significant improvement was observed in fatigue resist...

  12. Application of solid state silicon-29 and carbon-13 nuclear magnetic resonance spectroscopy to the characterization of inorganic matter-humic complexes in Athabasca oil sands

    International Nuclear Information System (INIS)

    In Athabasca oil sands there is a fraction of non-crystalline solids tightly bound to humic matter. It is believed, that the presence of this fraction, which resists subsequent wetting by water, introduces serious problems in bitumen recovery when using water based processes. In the present work, 29Si and 13C solid state magic angle spinning (MAS) NMR techniques were applied to characterize these solids which were isolated from Athabasca oil sands of estuarine and marine origin. On the basis of 29Si results it is suggested that there is a short-range disorder in these samples. It is also shown that aluminum is present in the nearest-neighbor environment of the silicon atoms, thus demonstrating that these solids are comprised of disordered alumino-silicates (allophanes). 13C CP/MAS NMR spectra of demineralized inorganic matter-humic complexes derived from both estuarine and marine oil sands indicate that the distribution of carbon types in each region of the spectra is similar, with aromatic carbon being the predominant type of carbon

  13. Effects of High Dissolved Inorganic and Organic Carbon Availability on the Physiology of the Hard Coral Acropora millepora from the Great Barrier Reef.

    Directory of Open Access Journals (Sweden)

    Friedrich W Meyer

    Full Text Available Coral reefs are facing major global and local threats due to climate change-induced increases in dissolved inorganic carbon (DIC and because of land-derived increases in organic and inorganic nutrients. Recent research revealed that high availability of labile dissolved organic carbon (DOC negatively affects scleractinian corals. Studies on the interplay of these factors, however, are lacking, but urgently needed to understand coral reef functioning under present and near future conditions. This experimental study investigated the individual and combined effects of ambient and high DIC (pCO2 403 μatm/ pHTotal 8.2 and 996 μatm/pHTotal 7.8 and DOC (added as Glucose 0 and 294 μmol L-1, background DOC concentration of 83 μmol L-1 availability on the physiology (net and gross photosynthesis, respiration, dark and light calcification, and growth of the scleractinian coral Acropora millepora (Ehrenberg, 1834 from the Great Barrier Reef over a 16 day interval. High DIC availability did not affect photosynthesis, respiration and light calcification, but significantly reduced dark calcification and growth by 50 and 23%, respectively. High DOC availability reduced net and gross photosynthesis by 51% and 39%, respectively, but did not affect respiration. DOC addition did not influence calcification, but significantly increased growth by 42%. Combination of high DIC and high DOC availability did not affect photosynthesis, light calcification, respiration or growth, but significantly decreased dark calcification when compared to both controls and DIC treatments. On the ecosystem level, high DIC concentrations may lead to reduced accretion and growth of reefs dominated by Acropora that under elevated DOC concentrations will likely exhibit reduced primary production rates, ultimately leading to loss of hard substrate and reef erosion. It is therefore important to consider the potential impacts of elevated DOC and DIC simultaneously to assess real world

  14. Response of dissolved inorganic carbon (DIC) and δ13CDIC to changes in climate and land cover in SW China karst catchments

    Science.gov (United States)

    Zhao, Min; Liu, Zaihua; Li, Hong-Chun; Zeng, Cheng; Yang, Rui; Chen, Bo; Yan, Hao

    2015-09-01

    Monthly hydrochemical data and δ13C of dissolved inorganic carbon (DIC) in karst water samples from September 2007 to October 2012 were obtained to reveal the controlling mechanisms on DIC geochemistry and δ13CDIC under different conditions of climate and land cover in three karst catchments: Banzhai, Dengzhanhe and Chenqi, in Guizhou Province, SW China. DIC of karst water at the Banzhai site comes mainly from carbonate dissolution under open system conditions with soil CO2 produced by root respiration and organic carbon decomposition with lowest δ13C values under its dense virgin forest coverage. Weaker carbonate bedrock dissolution due to sparse and thin soil cover results in lower δ13CDIC, pCO2, DIC and EC, and lower cation and anion concentrations. At the Chenqi site, larger soil CO2 input from a thick layer of soil results in high pCO2 and DIC, and low pH, SIc and δ13CDIC in the karst water. At the Dengzhanhe site, a lesser soil CO2 input due to stronger karst rock desertification and strong gypsum dissolution contribute to higher δ13CDIC, high EC and high cation and anion concentrations. Soil CO2 inputs, controlled by biological activity and available soil moisture, carbonate bedrock dissolution, dilution and degassing effects, vary seasonally following rainfall and temperature changes. Consequently, there are seasonal cycles in hydrochemistry and δ13CDIC of the karst water, with high pCO2 and low pH, EC, SIc, and δ13CDIC values in the warm and rainy seasons, and vice versa during the cold and dry seasons. A strongly positive shift (>3‰) in δ13CDIC occurred in the drought year, 2011, indicating that δ13CDIC in groundwater systems can be an effective indicator of environmental and/or climate changes.

  15. Effect of Inorganic and Organic Carbon Enrichments (DIC and DOC) on the Photosynthesis and Calcification Rates of Two Calcifying Green Algae from a Caribbean Reef Lagoon

    Science.gov (United States)

    Diele, Karen; Teichberg, Mirta; Wild, Christian

    2016-01-01

    Coral reefs worldwide are affected by increasing dissolved inorganic carbon (DIC) and organic carbon (DOC) concentrations due to ocean acidification (OA) and coastal eutrophication. These two stressors can occur simultaneously, particularly in near-shore reef environments with increasing anthropogenic pressure. However, experimental studies on how elevated DIC and DOC interact are scarce and fundamental to understanding potential synergistic effects and foreseeing future changes in coral reef function. Using an open mesocosm experiment, the present study investigated the impact of elevated DIC (pHNBS: 8.2 and 7.8; pCO2: 377 and 1076 μatm) and DOC (added as 833 μmol L-1 of glucose) on calcification and photosynthesis rates of two common calcifying green algae, Halimeda incrassata and Udotea flabellum, in a shallow reef environment. Our results revealed that under elevated DIC, algal photosynthesis decreased similarly for both species, but calcification was more affected in H. incrassata, which also showed carbonate dissolution rates. Elevated DOC reduced photosynthesis and calcification rates in H. incrassata, while in U. flabellum photosynthesis was unaffected and thalus calcification was severely impaired. The combined treatment showed an antagonistic effect of elevated DIC and DOC on the photosynthesis and calcification rates of H. incrassata, and an additive effect in U. flabellum. We conclude that the dominant sand dweller H. incrassata is more negatively affected by both DIC and DOC enrichments, but that their impact could be mitigated when they occur simultaneously. In contrast, U. flabellum can be less affected in coastal eutrophic waters by elevated DIC, but its contribution to reef carbonate sediment production could be further reduced. Accordingly, while the capacity of environmental eutrophication to exacerbate the impact of OA on algal-derived carbonate sand production seems to be species-specific, significant reductions can be expected under future

  16. Geochemical Impacts to Groundwater from Geologic Carbon Sequestration: Controls on pH and Inorganic Carbon Concentrations from Reaction Path and Kinetic Modeling

    Science.gov (United States)

    Geologic carbon sequestration has the potential to cause long-term reductions in global emissions of carbon dioxide to the atmosphere. Safe and effective application of carbon sequestration technology requires an understanding of the potential risks to the quality of underground...

  17. Hierarchically-organized, well-dispersed hydroxyapatite-coated magnetic carbon with combined organics and inorganics removal properties

    OpenAIRE

    Yang, Huihui; Liu, Qiang; Masse, Sylvie; Zhang, Hao; Li, Laifeng; ,; Coradin, Thibaud

    2015-01-01

    Novel hierarchically-organized magnetic microspheres have been successfully developed that consist of an aqueous hollow core, a magnetic porous Fe3O4-carbon layer and a well-define hydroxyapatite (HAp) shell. The hollow magnetic carbon microspheres were prepared by ultrasonic spray pyrolysis and coated with HAp using a biomimetic approach. The resulting powders exhibit micro- and meso-porosity. The removal capacity of the composite spheres towards an antibiotic (ampicilin), a rare-earth ion (...

  18. Stable isotope composition of inorganic carbonates from Lake Abiyata (Ethiopia): Attempt of reconstructing δ18O palaeohydrological changes during the Holocene

    International Nuclear Information System (INIS)

    Due to the sensitivity of its regional climate to the African monsoon seasonal shifting, Ethiopia has been designated as a key site for palaeoenvironmental reconstructions mainly within the IGBP-PAGES-PEPIII programme. Under the French-Ethiopian ERICA project, we focused on Lake Abiyata located in the Ziway-Shala basin (Central Ethiopia) which has experienced several lacustrine highstands during the Late Pleistocene and Holocene. At present, Lake Abiyata is a closed lake with a very flat catchment area, and corresponds to a half, deep graben infilled by 600-m of sedimentary deposits. In 1995, a 12.6-m-long sequence ABII was cored in Lake Abiyata. A reliable 14C-AMS chronology was defined on both organic matter and inorganic carbonates. Both the modern hydrologeological and geochemical balances of the 'groundwater-lake' system indicate that (i) carbonate cristallization mainly occurs at the water-sediment interface via the mixing of lake water and 14C-depleted groundwaters, and that (ii) modern algae form in equilibrium with the atmospheric reservoir. Phytoplankton is thus considered as an authigenic material, and Core ABII has registered 13,500 cal. yr B.P. of environmental history. The evidence of calcite precipitation at the water-sediment interface calls into question the direct palaeoclimatic reconstruction based on inorganic carbonates. Since the evolution of isotopic contents of carbonates might be linked to the variable proportion of the 'lake/groundwater' end-members in the mixing, calculations based on isotopic mass balance models may allow for the reconstruction of δ18O composition of the lake water. Two major changes can be highlighted: (i) the ∼12,000-5500 cal. yr B.P. period is associated to low 18O contents of lake water, and corresponds to an open hydrological system, with a high lacustrine phytoplanktonic productivity, and (ii) from ∼5500 cal. yr B.P. to Present, regressive conditions are suggested by the δ18O enrichment of the lake water

  19. Linear solvation energy relationships (LSER) for adsorption of organic compounds by carbon nanotubes.

    Science.gov (United States)

    Ersan, Gamze; Apul, Onur G; Karanfil, Tanju

    2016-07-01

    The objective of this paper was to create a comprehensive database for the adsorption of organic compounds by carbon nanotubes (CNTs) and to use the Linear Solvation Energy Relationship (LSER) technique for developing predictive adsorption models of organic compounds (OCs) by multi-walled carbon nanotubes (MWCNTs) and single-walled carbon nanotubes (SWCNTs). Adsorption data for 123 OCs by MWCNTs and 48 OCs by SWCNTs were compiled from the literature, including some experimental results obtained in our laboratory. The roles of selected OCs properties and CNT types were examined with LSER models. The results showed that the r(2) values of the LSER models displayed small variability for aromatic compounds smaller than 220 g/mol, after which a decreasing trend was observed. The data available for aliphatics was mainly for molecular weights smaller than 250 g/mol, which showed a similar trend to that of aromatics. The r(2) values for the LSER model on the adsorption of aromatic and aliphatic OCs by SWCNTs and MWCNTs were relatively similar indicating the linearity of LSER models did not depend on the CNT types. Among all LSER model descriptors, V term (molecular volume) for aromatic OCs and B term (basicity) for aliphatic OCs were the most predominant descriptors on both type of CNTs. The presence of R term (excess molar refractivity) in LSER model equations resulted in decreases for both V and P (polarizability) parameters without affecting the r(2) values. Overall, the results demonstrate that successful predictive models can be developed for the adsorption of OCs by MWCNTs and SWCNTs with LSER techniques. PMID:27064209

  20. Welcome to Inorganics: a new open access, inclusive forum for inorganic chemistry

    OpenAIRE

    Gregory, Duncan H.

    2013-01-01

    One of the beauties of inorganic chemistry is its sheer diversity. Just as chemistry sits at the centre of the sciences, inorganic chemistry sits at the centre of chemistry itself. Inorganic chemists are fortunate in having the entire periodic table at their disposal, providing a palette for the creation of a multitude of rich and diverse compounds and materials from the simplest salts to the most complex of molecular species. It follows that the language of inorganic chemistry can thus be a ...

  1. Exposure to carbon monoxide, respirable suspended particulates, and volatile organic compounds while commuting by bicycle

    International Nuclear Information System (INIS)

    A portable air sampling system has been used to assess exposures to various substances while commuting by bicycle in an urban area. The major source of pollutants in this situation is motor vehicle exhaust emissions. Carbon monoxide, measured by electrochemical detection, was found at peak concentrations in excess of 62 ppm, with mean values over 16 individual 35-mm journeys being 10.5 ppm. Respirable suspended particulates, averaged over each journey period, were found at higher concentrations (mean 130 μg m-3) than would be expected in indoor situations. Mean exposure to benzene (at 56 μg m-3) and other aromatic volatile organic compounds was also relatively high. The influence of wind conditions on exposure was found to be significant. Commuting exposures to carbon monoxide, respirable suspended particulates, and aromatic VOCs were found to be higher than exposures in a busy high street and on common parkland

  2. General synthesis of carbon nanocages and their adsorption of toxic compounds from cigarette smoke

    Science.gov (United States)

    Li, Guangda; Yu, Hongxiao; Xu, Liqiang; Ma, Qiang; Chen, Chao; Hao, Qin; Qian, Yitai

    2011-08-01

    Carbon nanocages (CNCs) have been synthesized through a simple approach using different alcohols and ferrous oxalate as reactants at 550 °C for 12 h in a sealed autoclave. The lengths of the sides of the CNCs are about 200-350 nm and the wall thicknesses are about 10-15 nm. The formation mechanism of the CNCs is also discussed, based on the experimental results. These CNCs show excellent removal efficiency for phenolic compounds, ammonia, and total particulate matter from cigarette smoke. The adsorption capability of CNCs prepared from ethanol is much higher than that of other samples. For example, the efficiency of 5 mg CNCs (ethanol) for removing the six phenolic compounds p-dihydroxybenzene, m-dihydroxybenzene, o-dihydroxybenzene, phenol, m-cresol, and o-cresol can reach 57.31%, 62.25%, 65.58%, 75.95%, 54.34% and 59.43%, respectively, while that of the commercial activated carbon (5 mg) can only reach 29.02%, 33.93%, 35.00%, 36.00%, 20.33% and 36.19%, respectively, under the same conditions.Carbon nanocages (CNCs) have been synthesized through a simple approach using different alcohols and ferrous oxalate as reactants at 550 °C for 12 h in a sealed autoclave. The lengths of the sides of the CNCs are about 200-350 nm and the wall thicknesses are about 10-15 nm. The formation mechanism of the CNCs is also discussed, based on the experimental results. These CNCs show excellent removal efficiency for phenolic compounds, ammonia, and total particulate matter from cigarette smoke. The adsorption capability of CNCs prepared from ethanol is much higher than that of other samples. For example, the efficiency of 5 mg CNCs (ethanol) for removing the six phenolic compounds p-dihydroxybenzene, m-dihydroxybenzene, o-dihydroxybenzene, phenol, m-cresol, and o-cresol can reach 57.31%, 62.25%, 65.58%, 75.95%, 54.34% and 59.43%, respectively, while that of the commercial activated carbon (5 mg) can only reach 29.02%, 33.93%, 35.00%, 36.00%, 20.33% and 36.19%, respectively, under

  3. Human Exposure and Health Effects of Inorganic and Elemental Mercury

    OpenAIRE

    Park, Jung-Duck; Zheng, Wei

    2012-01-01

    Mercury is a toxic and non-essential metal in the human body. Mercury is ubiquitously distributed in the environment, present in natural products, and exists extensively in items encountered in daily life. There are three forms of mercury, i.e., elemental (or metallic) mercury, inorganic mercury compounds, and organic mercury compounds. This review examines the toxicity of elemental mercury and inorganic mercury compounds. Inorganic mercury compounds are water soluble with a bioavailability o...

  4. LSER model for organic compounds adsorption by single-walled carbon nanotubes: Comparison with multi-walled carbon nanotubes and activated carbon.

    Science.gov (United States)

    Yu, Xiangquan; Sun, Weiling; Ni, Jinren

    2015-11-01

    LSER models for organic compounds adsorption by single and multi-walled carbon nanotubes and activated carbon were successfully developed. The cavity formation and dispersion interactions (vV), hydrogen bond acidity interactions (bB) and π-/n-electron interactions (eE) are the most influential adsorption mechanisms. SWCNTs is more polarizable, less polar, more hydrophobic, and has weaker hydrogen bond accepting and donating abilities than MWCNTs and AC. Compared with SWCNTs and MWCNTs, AC has much less hydrophobic and less hydrophilic adsorption sites. The regression coefficients (e, s, a, b, v) vary in different ways with increasing chemical saturation. Nonspecific interactions (represented by eE and vV) have great positive contribution to organic compounds adsorption, and follow the order of SWCNTs > MWCNTs > AC, while hydrogen bond interactions (represented by aA and bB) demonstrate negative contribution. These models will be valuable for understanding adsorption mechanisms, comparing adsorbent characteristics, and selecting the proper adsorbents for certain organic compounds. PMID:26319510

  5. Stable Carbon Isotope Ratios of Phenolic Compounds in Secondary Particulate Organic Matter Formed by Photooxidation of Toluene

    CERN Document Server

    Irei, Satoshi; Huang, Lin; Auld, Janeen; Collin, Fabrice; Hastie, Donald

    2014-01-01

    Compound-specific stable carbon isotope ratios for phenolic compounds in secondary particulate organic matter (POM) formed by photooxidation of toluene were studied. Secondary POM generated by photooxidation of toluene using a continuous-flow reactor and an 8 cubic meter indoor smog chamber was collected, and then extracted with acetonitrile. Eight phenolic compounds were identified in the extracts by a gas chromatograph coupled with a mass spectrometer, and their compound-specific stable carbon isotope ratios were determined by a gas chromatograph coupled with a combustion furnace followed by an isotope ratio mass spectrometer. The majority of the products, including methylnitrophenols and methylnitrocatechols, were isotopically depleted by 5 to 6 permil compared to the initial isotope ratio for toluene, whereas the isotope ratio for 4_nitrophenol remained the same as the initial isotope ratio for toluene. Based on the reaction mechanisms postulated in literature, stable carbon isotope ratios of these produc...

  6. Synthesis and Characterizaion of a New Inorganic-organic Sulfate Compound--Crystal Structure of [Ni(H2O)6][H2N(C2H4)2NH2](SO4)2

    Institute of Scientific and Technical Information of China (English)

    MENG He; XING Yan; FU Yun-long; SHI Zhan; PANG Wen-qin

    2004-01-01

    [Ni(H2O)6][H2N(C2H4)2NH2](SO4)2 is an inorganic-organic compound with a new open framework synthesized by hydrothermal method, and characterized by means of single-crystal diffraction and spectroscopic data. The compound crystallized in a monoclinic space group P21/n with a=1.29089(2) nm, b=1.06301(3) nm, c=1.33202(4) nm, β=114.0870(10)°, V=1.67127(8) nm3, Z=4, and was solved by using the direct method and the least-squares refinement converged at R=0.0214[I>2σ(I)]. The structure consists of isolated Ni(H2O)6 octahedra and SO4 tetrahedra, with both of them hydrogen-bonded to piperazine cations.

  7. Synthesis, crystal structure and luminescent properties of one new inorganic-organic hybrid compound [O 2NBzQL] 4[Cd(SCN) 4(NCS) 2] (O 2NBzQL = 1-(4'-NO 2-benzyl)quinolinium cation)

    Science.gov (United States)

    Bai, Yan; Hu, Xue-Fu; Dang, Dong-Bin; Bi, Feng-Lei; Niu, Jing-Yang

    2011-01-01

    A new inorganic-organic hybrid compound [O 2NBzQL] 4[Cd(SCN) 4(NCS) 2] (O 2NBzQL = 1-(4'-NO 2-benzyl)quinolinium cation) has been synthesized and characterized by IR, UV, elemental analysis and X-ray crystallography. Cd(II) atom has an distorted octahedral environment with an N 4S 2 donor set. In solid state there are three types of face-to-face π-π interactions between adjacent cations and multiform C-H⋯S and C-H⋯N hydrogen bonds between [O 2NBzQL] + cations and cadmium thiocyanate anions. The luminescent properties of the title compound were both investigated in H 2O solution and in solid state at room temperature, respectively.

  8. Effect of effluent organic matter on the adsorption of perfluorinated compounds onto activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Jing [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046 (China); College of Environmental Science and Engineering, Yangzhou University, 196 West Huayang Road, Yangzhou 225127 (China); Lv, Lu, E-mail: esellu@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046 (China); Lan, Pei [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046 (China); College of Environmental Science and Engineering, Yangzhou University, 196 West Huayang Road, Yangzhou 225127 (China); Zhang, Shujuan [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046 (China); Pan, Bingcai, E-mail: bcpan@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046 (China); Zhang, Weiming [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046 (China)

    2012-07-30

    Highlights: Black-Right-Pointing-Pointer The presence of EfOM significantly reduced the adsorption capacities and rates of PFCs. Black-Right-Pointing-Pointer Low-molecular-weight EfOM compounds (<1 kDa) compete for adsorption sites of PFSs directly. Black-Right-Pointing-Pointer Large-molecular-weight EfOM compounds (>30 kDa) affect the adsorption through pore blockage or restriction effect. Black-Right-Pointing-Pointer Changes in surface properties of PAC caused by preloaded EfOM could affect PFCs adsorption. - Abstract: Effect of effluent organic matter (EfOM) on the adsorption of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) onto powdered activated carbon (PAC) was quantitatively investigated at environmentally relevant concentration levels. The adsorption of both perfluorinated compounds (PFCs) onto PAC followed pseudo-second order kinetics and fitted the Freundlich model well under the given conditions. Intraparticle diffusion was found to be the rate-controlling step in the PFC adsorption process onto PAC in the absence and presence of EfOM. The presence of EfOM, either in PFC-EfOM simultaneous adsorption onto fresh PAC or in PFC adsorption onto EfOM-preloaded PAC, significantly reduced the adsorption capacities and sorption rates of PFCs. The pH of zero point of charge was found to be 7.5 for fresh PAC and 4.2 for EfOM-preloaded PAC, suggesting that the adsorbed EfOM imparted a negative charge on PAC surface. The effect of molecular weight distribution of EfOM on the adsorption of PFCs was investigated with two EfOM fractions obtained by ultrafiltration. The low-molecular-weight compounds (<1 kDa) were found to be the major contributors to the significant reduction in PFC adsorption capacity, while large-molecular-weight compounds (>30 kDa) had much less effect on PFC adsorption capacity.

  9. A flow injection analyser conductometric coupled system for the field analysis of free dissolved CO{sub 2} and total dissolved inorganic carbon in natural waters

    Energy Technology Data Exchange (ETDEWEB)

    Martinotti, Valter; Balordi, Marcella; Ciceri, Giovanni [RSE SpA - Environment and Sustainable Development Department, Milan (Italy)

    2012-05-15

    A flow injection analyser coupled with a gas diffusion membrane and a conductometric microdetector was adapted for the field analysis of natural concentrations of free dissolved CO{sub 2} and dissolved inorganic carbon in natural waters and used in a number of field campaigns for marine water monitoring. The dissolved gaseous CO{sub 2} presents naturally, or that generated by acidification of the sample, is separated by diffusion using a hydrophobic semipermeable gas porous membrane, and the permeating gas is incorporated into a stream of deionised water and measured by means of an electrical conductometric microdetector. In order to make the system suitable and easy to use for in-field measurements aboard oceanographic ships, the single components of the analyser were compacted into a robust and easy to use system. The calibration of the system is carried out by using standard solutions of potassium bicarbonate at two concentration ranges. Calibration and sample measurements are carried out inside a temperature-constant chamber at 25 C and in an inert atmosphere (N{sub 2}). The detection and quantification limits of the method, evaluated as 3 and 10 times the standard deviation of a series of measurements of the matrix solution were 2.9 and 9.6 {mu}mol/kg of CO{sub 2}, respectively. Data quality for dissolved inorganic carbon was checked with replicate measurements of a certified reference material (A. Dickson, Scripps Institution of Oceanography, University of California, San Diego), both accuracy and repeatability were -3.3% and 10%, respectively. Optimization, performance qualification of the system and its application in various natural water samples are reported and discussed. In the future, the calibration step will be operated automatically in order to improve the analytical performance and the applicability will be increased in the course of experimental surveys carried out both in marine and freshwater ecosystems. Considering the present stage of

  10. Distribution of Dissolved Inorganic Carbon (DIC) and Its Related Parameters in Seawater of the North Yellow Sea and off the Qingdao Coast in October, 2007

    Institute of Scientific and Technical Information of China (English)

    JI Hongwei; SHENG Guiyun; XIN Huizhen; SHA Yuanyuan

    2009-01-01

    Data on the distribution of dissolved inorganic carbon (DIC) were obtained from two cruises in the North Yellow Sea (NYS) and off the Qingdao Coast (QC) in October, 2007. Carbonate parameters were calculated. The concentrations of DIC are from 1.896-2.229 mmolL-1 in the NYS and from 1.939-2.032 mmolL-1 off the QC. In the southwest of the NYS, DIC in the upper layers decreases from the north of the SP (Shandong Peninsula) shelf to the center of the NYS; whereas in the lower layers DIC increases from the north of the SP shelf to the center of the NYS and South Yellow Sea. In the northeast of the NYS, DIC in all layers increases from the YR (Yalu River) estuary to the centre of the NYS. The distribution of DIC in NYS can be used as an indicator of Yellow Sea Cold Water Mass (YSCWM). Air-sea CO: fluxes were calculated using three models and the results suggest that both the NYS and the QC waters are potential sources of atmospheric CO2 in October.

  11. Resolution of Adsorption and Partition Components of Organic Compounds on Black Carbons.

    Science.gov (United States)

    Chiou, Cary T; Cheng, Jianzhong; Hung, Wei-Nung; Chen, Baoliang; Lin, Tsair-Fuh

    2015-08-01

    Black carbons (BCs) may sequester non-ionic organic compounds by adsorption and/or partition to varying extents. Up to now, no experimental method has been developed to accurately resolve the combined adsorption and partition capacity of a compound on a BC. In this study, a unique "adsorptive displacement method" is introduced to reliably resolve the adsorption and partition components for a solute-BC system. It estimates the solute adsorption on a BC by the use of an adsorptive displacer to displace the adsorbed target solute into the solution phase. The method is validated by tests with uses of activated carbon as the model carbonaceous adsorbent, soil organic matter as the model carbonaceous partition phase, o-xylene and 1,2,3-trichlorobenzene as the reference solutes, and p-nitrophenol as the adsorptive displacer. Thereafter, the adsorption-partition resolution was completed for the two solutes on selected model BCs: four biochars and two National Institute of Standards and Technology (NIST) standard soots (SRM-2975 and SRM-1650b). The adsorption and partition components resolved for selected solutes with given BCs and their dependences upon solute properties enable one to cross-check the sorption data of other solutes on the same BCs. The resolved components also provide a theoretical basis for exploring the potential modes and extents of different solute uptakes by given BCs in natural systems. PMID:26114972

  12. Experimental evaluation of biomass burning emissions: Nitrogen and carbon containing compounds

    International Nuclear Information System (INIS)

    Data are presented on the nitrogen and carbon emissions of biomass burning. The results of the authors' experiments enable them to calculate new source strengths for many compounds, considering different burning stages and fire conditions on the one hand, and different fuel types and properties, on the other hand. They also presented a method for balancing elemental budgets of fires, which had already been described for carbon compounds by other authors but which is new for the nitrogen inventory. Based on their measurements they show that biomass burning contributes significantly to the global budgets of HCN, CH3CN (possibly the major source), NOx (12%), CO(22%), C2 to C4 hydrocarbons (14%), CH3Cl(41%), and probably also to the global source of C1-C5 aliphatic amines. Further, pyrogenic CO2 amounts are likely to represent a substantial contribution to the global greenhouse warming. An important result, from the study is the identification of N2 emissions, which causes a significant loss of fixed nitrogen (pyro-denitrification) in tropical ecosystems in the order of 5% to 20% of the global nitrogen fixation rate. Because of an interesting interplay between an enhanced postfire nitrogen fixation and an enhanced postfire N2O emission, it is not yet known if losses due to pyro-denitrification are balanced by nitrogen fixation

  13. Coupled organic and inorganic carbon cycling in the deep subseafloor sediment of the northeastern Bering Sea Slope (IODP Exp. 323)

    DEFF Research Database (Denmark)

    Wehrmann, Laura M.; Risgaard-Petersen, Nils; Schrum, Heather;

    2011-01-01

    at water depths of 1008 to 3172 m. They are situated in the high productivity “Green Belt” region, with organic carbon burial rates typical of the high-productivity upwelling domains on western continental margins. The three sites show strong geochemical similarities. The downward sequence of...

  14. Effectiveness of submersed angiosperm-epiphyte complexes on exchange of nutrients and organic carbon in littoral systems. I. Inorganic nutrients

    Energy Technology Data Exchange (ETDEWEB)

    Mickle, A.M.; Wetzel, R.G.

    1978-01-01

    Inorganic chemical parameters were analyzed daily for several weeks in water from an inlet stream of a small hardwater lake before and after passing through two replicated continuously, very slowly flowing (3 1/24 h) littoral systems containing natural stands of submerged Scirpus subterminalis Torr. and of Myriophyllum heterophyllum Michx. Macrophytic epiphytes were left intact. Calcium and alkalinity concentrations of the inflowing water decreased 40 to 45% in passing through the littoral systems. In both systems, pH values increased significantly, but to a greater extent in the more metabolically active Myriophyllum (than the Scirpus) littoral bed. Magnesium concentrations remained constant in passage through both systems. Sodium concentrations were unaffected by the Scirpus system but increased (8%) in the outflow from the Myriophyllum system. In contrast to the Scirpus system where potassium increased slightly, potassium concentrations decreased markedly (> 30%) in passage through the Myriophyllum complex. Nitrate-nitrogen concentrations were reduced significantly and NH/sub 4/-N decreased only slightly in both plant systems. Concentrations of NH/sub 4/-N and potassium increased markedly in inflow water after periods of rainfall. Both littoral systems were extremely effective in dampening these higher concentrations; only slight increases appeared in the outflows after passing slowly through the littoral complexes.

  15. Effectiveness of submersed angiosperm-epiphyte complexes on exchange of nutrients and organic carbon in littoral systems. I. Inorganic nutrients

    Energy Technology Data Exchange (ETDEWEB)

    Mickle, A.M.; Wetzel, R.G.

    1978-01-01

    Inorganic chemical parameters were analyzed daily for several weeks in water from an inlet stream of a small hardwater lake before and after passing through two replicated continuously, very slowly flowing (3 1/24 h) littoral systems containing natural strands of submerged Scripus subterminalis Torr. and of Myriophyllum heterophyllum Michx. Macrophytic epiphytes were left intact. Calcium and alkalinity concentrations of the inflowing water decreased 40 to 45% in passing through the littoral systems. In both systems, pH values increased significantly, but to a greater extent in the more metabolically active Myriophyllum (than the Scirpus) littoral bed. Magnesium concentrations remained constant in passage through both systems. Sodium concentrations were unaffected by the Scirpus system but increased (8%) in the outflow from the Myriophyllum system. In contrast to the Scirpus system where potassium increased slightly, potassium concentrations decreased markedly (> 30%) in passage through the Myriophyllum complex. Nitrate-nitrogen concentrations were reduced significantly and NH/sub 4/-N decreased only slightly in both plant systems. Concentrations of NH/sub 4/-N and potassium increased markedly in inflow water after periods of rainfall. Both littoral systems were extremely effective in dampening these higher concentrations; only slight increases appeared in the outflows after passing slowly through the littoral complexes.

  16. Assessment of ethylene dibromide, dibromochloropropane, other volatile organic compounds, radium isotopes, radon, and inorganic compounds in groundwater and spring water from the Crouch Branch and McQueen Branch aquifers near McBee, South Carolina, 2010-2012

    Science.gov (United States)

    Landmeyer, James E.; Campbell, Bruce G.

    2014-01-01

    Public-supply wells near the rural town of McBee, in southwestern Chesterfield County, South Carolina, have provided potable water to more than 35,000 residents throughout Chesterfield County since the early 1990s. Groundwater samples collected between 2002 and 2008 in the McBee area by South Carolina Department of Health and Environmental Control (DHEC) officials indicated that groundwater from two public-supply wells was characterized by the anthropogenic compounds ethylene dibromide (EDB) and dibromochloropropane (DBCP) at concentrations that exceeded their respective maximum contaminant levels (MCLs) established by the U.S. Environmental Protection Agency’s (EPA) National Primary Drinking Water Regulations (NPDWR). Groundwater samples from all public-supply wells in the McBee area were characterized by the naturally occurring isotopes of radium-226 and radium-228 at concentrations that approached, and in one well exceeded, the MCL for the combined isotopes. The local water utility installed granulated activated carbon filtration units at the two EDB- and DBCP-contaminated wells and has, since 2011, shut down these two wells. Groundwater pumped by the remaining public-supply wells is currently (2014) centrally treated at a water-filtration plant.

  17. Applications of compound-specific carbon isotope ratios in organic contaminant studies

    International Nuclear Information System (INIS)

    In this paper results are presented on the application of compound-specific isotope ratios measurements to assess biodegradation of chlorinated solvents, in particularly on microbial dechlorination of tetrachloroethene (PCE) and trichloroethene (TCE). Analytical aspects and isotope data from laboratory and field studies are discussed. The analytical tests showed that both headspace and SPME techniques provide accurate δ13C values with a similar precision for a wide range of chlorinated solvents. However, the SPME method is generally more sensitive. The microcosm experiments show that a significant isotopic fractionation occurs during dechlorination of PCE and TCE to ethene. The largest fractionation factors are observed in the steps DCE-VC and VC-Ethene. In general, the δ13C of each dechlorination product was always more negative than the δ13C of the corresponding precursor. In addition, the δ13C values of each compound increased with time. A similar pattern was observed for dechlorination of PCE at a field site. These results show that compound-specific carbon isotope ratios technology is a very sensitive tool for evaluation of natural attenuation of chlorinated solvents in groundwater. (author)

  18. Predicting adsorption of aromatic compounds by carbon nanotubes based on quantitative structure property relationship principles

    Science.gov (United States)

    Rahimi-Nasrabadi, Mehdi; Akhoondi, Reza; Pourmortazavi, Seied Mahdi; Ahmadi, Farhad

    2015-11-01

    Quantitative structure property relationship (QSPR) models were developed to predict the adsorption of aromatic compounds by carbon nanotubes (CNTs). Five descriptors chosen by combining self-organizing map and stepwise multiple linear regression (MLR) techniques were used to connect the structure of the studied chemicals with their adsorption descriptor (K∞) using linear and nonlinear modeling techniques. Correlation coefficient (R2) of 0.99 and root-mean square error (RMSE) of 0.29 for multilayered perceptron neural network (MLP-NN) model are signs of the superiority of the developed nonlinear model over MLR model with R2 of 0.93 and RMSE of 0.36. The results of cross-validation test showed the reliability of MLP-NN to predict the K∞ values for the aromatic contaminants. Molar volume and hydrogen bond accepting ability were found to be the factors much influencing the adsorption of the compounds. The developed QSPR, as a neural network based model, could be used to predict the adsorption of organic compounds by CNTs.

  19. Enhanced separation of Compound Xueshuantong capsule using functionalized carbon nanotubes with cationic surfactant solutions in MEEKC.

    Science.gov (United States)

    Cao, Jun; Li, Ping; Chen, Jue; Tan, Ting; Dai, Han-Bin

    2013-01-01

    A novel additive of multi-walled carbon nanotubes (MWNTs) dispersed with cationic surfactants or mixed cationic/anionic surfactants was used for MEEKC separation of eight phenolic compounds, four glycosides, and one phenanthraquinone. In this context, several parameters affecting MEEKC separation were studied, including the dispersion agents of MWNTs, MWNTs content, oil type, SDS concentration, and the type and concentration of cosurfactant. Compared with conventional MEEKC, the addition of all types of MWNTs dispersions using single or mixed cationic surfactant solutions in running buffers was especially useful for improving the separation of solutes tested, as they influenced the partitioning between the oil droplets and aqueous phase due to the exceptional electrical properties and large surface areas of MWNTs. Use of cationic surfactant-coated MWNTs (6.4 μg/mL) as the additive in a microemulsion buffer (0.5% octanol, 2.8% SDS, 5.8% isopropanol, and 5 mM borate buffer) yielded complete resolution of 13 analytes. The proposed method has been successfully applied for the detection and quantification of the studied compounds in a complex matrix sample (Compound Xueshuantong capsule). PMID:23161282

  20. Electrically Conductive Compounds of Polycarbonate, Liquid Crystalline Polymer, and Multiwalled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Penwisa Pisitsak

    2012-01-01

    Full Text Available A thermotropic liquid crystalline polymer (LCP was blended with polycarbonate (PC and multiwalled carbon nanotube (CNT with the goal of improving electrical conductivity and mechanical properties over PC. The LCP was anticipated to produce fibrillar domains in PC and help improve the mechanical properties. The study was carried out using two grades of LCP—Vectra A950 (VA950 and Vectra V400P (V400P. The compounds contained 20 wt% LCP and 0.5 to 15 wt% CNT. The compounds were prepared by melt-blending in a twin-screw minicompounder and then injection molded using a mini-injection molder. The fibrillar domains of LCP were found only in the case of PC/VA950 blend. However, these fibrils turned into droplets in the presence of CNT. It was found that CNT preferentially remained inside the LCP domains as predicted from the value of spreading coefficient. The electrical conductivity showed the following order with the numbers in parenthesis representing the electrical percolation threshold of the compounds: PC/CNT (1% > PC/VA950P/CNT (1% > PC/V400P/CNT (3%. The storage modulus showed improvements with the addition of CNT and VA950.

  1. Removal of sulfur compounds from petroleum refinery wastewater through adsorption on modified activated carbon.

    Science.gov (United States)

    Ben Hariz, Ichrak; Al Ayni, Foued; Monser, Lotfi

    2014-01-01

    The adsorption of sulfur compounds from petroleum refinery wastewater on a chemically modified activated carbon (MAC) was investigated. The modification technique (nitric acid, hydrogen peroxide and thermal modification) enhanced the removal capacity of carbon and therefore decreases cost-effective removal of sulfide from refinery wastewater. Adsorption equilibrium and kinetics data were determined for sulfur removal from real refinery wastewater. The data were evaluated according to several adsorption isotherm and kinetics models. The Freundlich isotherm fitted well with the equilibrium data of sulfur on different adsorbents, whereas the kinetics data were best fitted by the pseudo-second-order model. Insights of sulfide removal mechanisms indicated that the sorption was controlled through the intraparticle diffusion mechanism with a significant contribution of film diffusion. The MAC adsorbent was found to have an effective removal capacity of approximately 2.5 times that of non-modified carbon. Using different MAC, sulfides were eliminated with a removal capacity of 52 mg g(-1). Therefore, MAC can be utilized as an effective and less expensive adsorbent for the reduction of sulfur in refinery wastewater. PMID:25353943

  2. A modelling exercise on the importance of ternary alkaline earth carbonate species of uranium(VI) in the inorganic speciation of natural waters

    International Nuclear Information System (INIS)

    Highlights: • The U(VI) speciation in natural waters has been modelled through a modelling exercise. • The results evidence the importance of alkaline earth U(VI) carbonate complexes. • Possible solubility-controlling phases were reported and discussed. • The differences were related to the choice and reliability of thermodynamic data. • Databases need to be improved for reliable U(VI) speciation calculations. - Abstract: Predictive modelling of uranium speciation in natural waters can be achieved using equilibrium thermodynamic data and adequate speciation software. The reliability of such calculations is highly dependent on the equilibrium reactions that are considered as entry data, and the values chosen for the equilibrium constants. The working group “Speciation” of the CETAMA (Analytical methods establishment committee of the French Atomic Energy commission, CEA) has organized a modelling exercise, including four participants, in order to compare modellers’ selections of data and test thermodynamic data bases regarding the calculation of U(VI) inorganic speciation. Six different compositions of model waters were chosen so that to check the importance of ternary alkaline earth carbonate species of U(VI) on the aqueous speciation, and the possible uranium solid phases as solubility-limiting phases. The comparison of the results from the participants suggests (i) that it would be highly valuable for end-users to review thermodynamic constants of ternary carbonate species of U(VI) in a consistent way and implement them in available speciation data bases, and (ii) stresses the necessary care when using data bases to avoid biases and possible erroneous calculations

  3. The removal of endocrine disrupting compounds, pharmaceutically activated compounds and cyanobacterial toxins during drinking water preparation using activated carbon--a review.

    Science.gov (United States)

    Delgado, Luis F; Charles, Philippe; Glucina, Karl; Morlay, Catherine

    2012-10-01

    This paper provides a review of recent scientific research on the removal by activated carbon (AC) in drinking water (DW) treatment of 1) two classes of currently unregulated trace level contaminants with potential chronic toxicity-pharmaceutically activate compounds (PhACs) and endocrine disrupting compounds (EDCs); 2) cyanobacterial toxins (CyBTs), which are a group of highly toxic and regulated compounds (as microcystin-LR); and 3) the above mentioned compounds by the hybrid system powdered AC/membrane filtration. The influence of solute and AC properties, as well as the competitive effect from background natural organic matter on the adsorption of such trace contaminants, are also considered. In addition, a number of adsorption isotherm parameters reported for PhACs, EDCs and CyBTs are presented herein. AC adsorption has proven to be an effective removal process for such trace contaminants without generating transformation products. This process appears to be a crucial step in order to minimize PhACs, EDCs and CyBTs in finished DW, hence calling for further studies on AC adsorption removal of these compounds. Finally, a priority chart of PhACs and EDCs warranting further study for the removal by AC adsorption is proposed based on the compounds' structural characteristics and their low removal by AC compared to the other compounds. PMID:22885596

  4. High Carbon Use Efficiency is Not Explained by Production of Storage Compounds

    Science.gov (United States)

    Dijkstra, Paul; van Groenigen, Kees-Jan

    2015-04-01

    The efficiency with which microbes use substrate to make new microbial biomass (Carbon Use Efficiency or CUE; mol C / mol C) is an important variable in soil and ecosystem C cycling models. Estimates of CUE in soil microbial communities vary widely. It has been hypothesized that high values of CUE are associated with production of storage compounds following a sudden increases in substrate availability during CUE measurements. In that case, these high CUE values would not be representative for balanced microbial growth (i.e. the production of all compounds needed to make new microbial cells). To test this hypothesis, we added position-specific 13C-labeled glucose isotopomers in parallel incubations of a ponderosa pine and piñon-juniper soil. We compared the measured pattern of CO2 release for the six glucose C atoms with patterns of CO2 production expected for balanced growth with a low, medium, or high CUE, and with CO2 production patterns associated with production of storage compounds (glycogen, lipids, or polyhydroxybutyrate). The measured position-specific CO2 production did not match that for production of glycogen, lipids, or polyhydroxybutyrate, but agreed closely with that expected for balanced growth at high CUE and high pentose phosphate pathway activity. We conclude that soil microbial communities utilize glucose substrate for biomass growth with high CUE, and that addition of small amounts of 13C-labeled glucose tracers do not affect CUE or induce storage compounds production. We submit that the measurement of position-specific CO2 production offers a quick and easy way to test biochemically explicit hypotheses concerning microbial growth metabolism.

  5. Rare earths: preparation of spectro chemically pure standards, study of their carbonates and synthesis of a new compound series - the peroxy carbonates

    International Nuclear Information System (INIS)

    In this work the following studies are concerned: I) preparation of lanthanum, cerium, praseodymium, neodymium and samarium oxides for use as spectro chemically pure standards; II) behavior of the rare earth (La, Ce, Pr, Nd, Sm) carbonates soluble in ammonium carbonate and mixture of ammonium carbonate/ammonium hydroxide, and III) synthesis and characterization of rare earth peroxy carbonates - a new series of compounds. Data for the synthesis and characterization of the rare earths peroxy carbonates described for the first time in this work are presented and discussed. With the aid of thermal analysis (TG-DTG) the thermal stability and the stoichiometric composition for new compounds were established and a mechanism of thermal decomposition was proposed. The peroxy carbonate was prepared by the addition of hydrogen peroxyde to the complexed soluble rare earths carbonates. These studies included also the determinations of active oxygen, the total rare earth oxide by gravimetry and complexometry and the C, H and N contents by microanalysis. The new compounds were also investigated by infrared spectroscopy. (author)

  6. Theoretical constraints on the effects of pH, salinity, and temperature on clumped isotope signatures of dissolved inorganic carbon species and precipitating carbonate minerals

    OpenAIRE

    Hill, PS; Tripati, AK; Schauble, EA

    2014-01-01

    The use of carbonate 'clumped isotope' thermometry as a geochemical technique to determine temperature of formation of a carbonate mineral is predicated on the assumption that the mineral has attained an internal thermodynamic equilibrium. If true, then the clumped isotope signature is dependent solely upon the temperature of formation of the mineral without the need to know the isotopic or elemental composition of coeval fluids. However, anomalous signatures can arise under disequilibrium co...

  7. Characterization, Quantification and Compound-specific Isotopic Analysis of Pyrogenic Carbon Using Benzene Polycarboxylic Acids (BPCA).

    Science.gov (United States)

    Wiedemeier, Daniel B; Lang, Susan Q; Gierga, Merle; Abiven, Samuel; Bernasconi, Stefano M; Früh-Green, Gretchen L; Hajdas, Irka; Hanke, Ulrich M; Hilf, Michael D; McIntyre, Cameron P; Scheider, Maximilian P W; Smittenberg, Rienk H; Wacker, Lukas; Wiesenberg, Guido L B; Schmidt, Michael W I

    2016-01-01

    Fire-derived, pyrogenic carbon (PyC), sometimes called black carbon (BC), is the carbonaceous solid residue of biomass and fossil fuel combustion, such as char and soot. PyC is ubiquitous in the environment due to its long persistence, and its abundance might even increase with the projected increase in global wildfire activity and the continued burning of fossil fuel. PyC is also increasingly produced from the industrial pyrolysis of organic wastes, which yields charred soil amendments (biochar). Moreover, the emergence of nanotechnology may also result in the release of PyC-like compounds to the environment. It is thus a high priority to reliably detect, characterize and quantify these charred materials in order to investigate their environmental properties and to understand their role in the carbon cycle. Here, we present the benzene polycarboxylic acid (BPCA) method, which allows the simultaneous assessment of PyC's characteristics, quantity and isotopic composition ((13)C and (14)C) on a molecular level. The method is applicable to a very wide range of environmental sample materials and detects PyC over a broad range of the combustion continuum, i.e., it is sensitive to slightly charred biomass as well as high temperature chars and soot. The BPCA protocol presented here is simple to employ, highly reproducible, as well as easily extendable and modifiable to specific requirements. It thus provides a versatile tool for the investigation of PyC in various disciplines, ranging from archeology and environmental forensics to biochar and carbon cycling research. PMID:27214064

  8. Characterization, Quantification and Compound-specific Isotopic Analysis of Pyrogenic Carbon Using Benzene Polycarboxylic Acids (BPCA)

    Science.gov (United States)

    Wiedemeier, Daniel B.; Lang, Susan Q.; Gierga, Merle; Abiven, Samuel; Bernasconi, Stefano M.; Früh-Green, Gretchen L.; Hajdas, Irka; Hanke, Ulrich M.; Hilf, Michael D.; McIntyre, Cameron P.; Scheider, Maximilian P. W.; Smittenberg, Rienk H.; Wacker, Lukas; Wiesenberg, Guido L. B.; Schmidt, Michael W. I.

    2016-01-01

    Fire-derived, pyrogenic carbon (PyC), sometimes called black carbon (BC), is the carbonaceous solid residue of biomass and fossil fuel combustion, such as char and soot. PyC is ubiquitous in the environment due to its long persistence, and its abundance might even increase with the projected increase in global wildfire activity and the continued burning of fossil fuel. PyC is also increasingly produced from the industrial pyrolysis of organic wastes, which yields charred soil amendments (biochar). Moreover, the emergence of nanotechnology may also result in the release of PyC-like compounds to the environment. It is thus a high priority to reliably detect, characterize and quantify these charred materials in order to investigate their environmental properties and to understand their role in the carbon cycle. Here, we present the benzene polycarboxylic acid (BPCA) method, which allows the simultaneous assessment of PyC's characteristics, quantity and isotopic composition (13C and 14C) on a molecular level. The method is applicable to a very wide range of environmental sample materials and detects PyC over a broad range of the combustion continuum, i.e., it is sensitive to slightly charred biomass as well as high temperature chars and soot. The BPCA protocol presented here is simple to employ, highly reproducible, as well as easily extendable and modifiable to specific requirements. It thus provides a versatile tool for the investigation of PyC in various disciplines, ranging from archeology and environmental forensics to biochar and carbon cycling research. PMID:27214064

  9. Spectroscopic Studies of Azul Maya: Novel Organic/Inorganic Complexes

    Science.gov (United States)

    Reza, Layra; Manciu, Felicia; Torres, Brenda; Polette, Lori; Chianelli, Russell

    2006-10-01

    Maya pigments are novel organic/inorganic hybrid materials with multiple technological applications. The materials are surface compounds formed by heating an organic molecule such as indigo with an inorganic compound such as palygorskite, which is a common clay. The organic molecule upon heating forms a strong interaction with the clay surface stabilizing both entities. This strong interaction is exhibited through a color change from deep blue to the well-known Maya Blue indicating an exchange of electron density at the surface. Analysis by infrared absorption and Raman spectroscopy demonstrate the disappearance of nitrogen-hydrogen (N-H) bonding, as the indigo molecule incorporates into the inorganic palygorskite material. Infrared data confirm the loss of zeolitic water and a partial removal of structural water after the heating process. Carbon and oxygen studies at Stanford Synchrotron Radiation Laboratory by X-Ray photoemission spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS), respectively, suggest possible cationic (Al^+3) bonding of the organic molecule to palygorskite compound.

  10. Liquid-phase adsorption of multi-ring thiophenic sulfur compounds on carbon materials with different surface properties.

    Science.gov (United States)

    Zhou, Anning; Ma, Xiaoliang; Song, Chunshan

    2006-03-16

    This work examines the effects of structural and surface properties of carbon materials on the adsorption of benzothiophene (BT), dibenzothiophene (DBT), 4-methyldibenzothiophene (4-MDBT) and 4,6-dimethyl-dibenzothiophene (4,6-DMDBT) in the presence of 10 wt % of aromatics in liquid alkanes that simulate sulfur compounds in diesel fuels. The equilibrium-adsorption capacity varies significantly, from 1.7 to 7.0 mg-S/g-A. The results show that different carbon materials have significantly different sulfur-adsorption capacities and selectivities that depend not only on textural structure but also on surface functional groups. The adsorption of multi-ring sulfur compounds on carbon materials was found to obey the Langmuir isotherm. On the basis of adsorption tests and the characterization of carbon materials by BET and XPS, the oxygen-containing functional groups on the surface appear to play an important role in increasing sulfur-adsorption capacity. The adsorption-selectivity trend of the carbon materials for various compounds increases in the order of BT adsorption over nickel-based adsorbents. The regeneration of spent activated carbons was also conducted by solvent washing. The high-adsorption capacity and selectivity for methyl DBTs indicate that certain activated carbons are promising adsorbents for selective adsorption for removing sulfur (SARS) as a new approach to ultra deep desulfurization of diesel fuels. PMID:16526705

  11. Compound-Specific Carbon and Hydrogen Isotope Analysis - Field Evidence of MTBE Bioremediation

    Science.gov (United States)

    Kuder, T.; Kolhatkar, R. V.; Philp, P.; Wilson, J. T.; Landmeyer, J. E.; Allen, J.

    2002-12-01

    Compound-specific stable isotope analysis allows opportunity to determine the isotopic ratios of individual contaminants. The technique has been applied to confirm biodegradation in studies of chlorinated solvents and recently BTEX, MTBE and TBA. Chemical reactions (including bio- and inorganic degradation) tend to favor molecules with the lighter isotopic species (e.g., 12C, 1H), resulting with enrichment of the unreacted substrate in the heavier isotopic species (13C, D), referred to as kinetic isotopic fractionation, so that the extent of fractionation may be used as a proxy for biodegradation. Processes such as volatilization, sorption etc., result in minimal degree of fractionation and do not interfere with the isotopic signal due to biodegradation. The results presented here show the first successful applications of compound-specific isotope analysis to understanding MTBE biodegradation in the field, at both aerobic and anaerobic sites. Observed fractionations suggest that two different biodegradation pathways may be involved. At a number of anaerobic locations major fractionation effects were observed for both C and H; enrichment factors Ÿnfor both elements were approaching or exceeding -10. A laboratory microcosm study using an enrichment culture yielded similar results (C data only). A characteristic feature of these sites was the presence of high concentrations of TBA. Conversely, at a number of sites, the C composition remained stable with little fractionation and stayed within the analytical precision range or changed minimally, while H displayed significant fractionation in excess of 60 per mil. Moderate agreement of the data with Rayleigh fractionation model was observed, suggesting that biodegradation effect was distorted by variability at the source or the plume was not homogeneous. The enrichment factor calculated for these data is similar to the one Ÿnpublished for aerobic microcosm of MTBE-degrading culture from Vandenberg AFB by Gray et al

  12. Variations in short term products of inorganic carbon fixation in exponential and stationary phase cultures of Aphanocapsa 6308.

    Science.gov (United States)

    Weathers, P J; Allen, M M

    1978-03-01

    Aphanocapsa 6308 metabolizes both NaHCO3 and Na2CO3. The short term incorporation (5-s) metabolic pattern and the patterns of incorporation of bicarbonate for exponential versus stationary phase cultures differ, however. Cells were equilibrated for 10 min in air and distilled water prior to injection of either NaH14CO3 at pH 8.0, or Na214CO3 at pH 11.0. Hot ethanol extracts were analyzed via paper chromatography and autoradiography for products of CO2 fixation. At 5 s, malate (51.5%) predominates slightly as a primary bicarbonate fixation product over 3-phosphoglycerate (40.3%); 3-phosphoglycerate is the primary product of carbonate fixation. At 60 s, the carbonate and bicarbonate labelling patterns are similar. Cells in stationary phase fix in 5 s a greater proportion of bicarbonate into malate (36% vs. 14% for 3-phosphoglycerate) than do cells in exponential growth. Likewise, 60 s incorporations show a large amount of bicarbonate fixed into aspartate (30.9%) in stationary phase cells over that of exponential phase (11.6%). These data suggest an operative C4 pathway for purposes not related to carbohydrate synthesis but rather as compensation for the incomplete tricarboxylic acid cycle in cyanobacteria. The enhancement of both aspartate fixation and CO2 fixation into citrulline in stationary phase correlates with an increase in cyanophycin granule production which requires both aspartate and arginine. PMID:417691

  13. RT-MATRIX: Measuring Total Organic Carbon by Photocatalytic Oxidation of Volatile Organic Compounds

    Science.gov (United States)

    2008-01-01

    Volatile organic compounds (VOCs) inevitably accumulate in enclosed habitats such as the International Space Station and the Crew Exploration Vehicle (CEV) as a result of human metabolism, material off-gassing, and leaking equipment. Some VOCs can negatively affect the quality of the crew's life, health, and performance; and consequently, the success of the mission. Air quality must be closely monitored to ensure a safe living and working environment. Currently, there is no reliable air quality monitoring system that meets NASA's stringent requirements for power, mass, volume, or performance. The ultimate objective of the project -- the development of a Real-Time, Miniaturized, Autonomous Total Risk Indicator System (RT.MATRIX).is to provide a portable, dual-function sensing system that simultaneously determines total organic carbon (TOC) and individual contaminants in air streams.

  14. The Synthesis of Imidazoline Derivative Compounds as Corrosion Inhibitor towards Carbon Steel in 1% NaCl Solution

    Directory of Open Access Journals (Sweden)

    Deana Wahyuningrum

    2008-03-01

    Full Text Available Oleic imidazoline is one of the nitrogen containing heterocyclic compounds that has been widely used as commercial corrosion inhibitor, especially in minimizing the carbon dioxide induced corrosion process in oilfield mining. In this present work, some imidazoline derivative compounds have been synthesized utilizing both conventional and microwave assisted organic synthesis (MAOS methods, in order to determine their corrosion inhibition properties on carbon steel surface. The MAOS method is more effective in synthesizing these compounds than the conventional method regarding to the higher chemical yields of products (91% to 94% and the shorter reaction times (7 to 10 minutes. The characterization of corrosion inhibition activities of the synthesized products towards carbon steel in 1% NaCl solution was determined by the Tafel plot method. The corrosion inhibition activities of compound 1b ((Z-2-(2-(heptadec-8-enyl-4,5-dihydroimidazol-1-ylethanamine, 2b ((Z-2-(2-(heptadec-8-enyl-4,5-dihydroimidazol-1-ylethanol and 3b (2-(2-heptadecyl-4,5-dihydroimidazol-1-ylethanamine at 8 ppm concentration in 1% NaCl solution are, respectively, 32.18%, 39.59% and 12.73%. The heptadec-8-enyl and hydroxyethyl substituents at C(2 and N(1 position of imidazoline ring, respectively, gave the most effective corrosion inhibition activity towards carbon steel compared to the presence of other substituents. The increase in concentrations of compound 1b, 2b and 3b in 1% NaCl solution tends to improve their corrosion inhibition activities. Based on the analysis of the free Gibbs adsorption energy (DG0ads values of compound 1b, 2b and 3b (-32.97, -34.34 and -31.27 kJ/mol, respectively, these compounds have the potential to interact with carbon steel through semi-physiosorption or semi-chemisorption.

  15. Mechanical properties of PET composites using multi-walled carbon nanotubes functionalized by inorganic and itaconic acids

    Directory of Open Access Journals (Sweden)

    A. May-Pat

    2012-02-01

    Full Text Available Multi-walled carbon nanotubes (MWCNTs were oxidized by two different acid treatments and further functionalized with itaconic acid (IA. The functionalized MWCNTs were used to fabricate Poly(ethylene terephthalate (PET composites by melt mixing. The presence of functional groups on the surface of the treated MWCNTs was confirmed by infrared spectroscopy and thermogravimetric analysis. The MWCNTs oxidized with a concentrated mixture of HNO3 and H2SO4 exhibited more oxygen containing functional groups (OH, COOH but also suffer larger structural degradation than those oxidized by a mild treatment based on diluted HNO3 followed by H2O2. PET composites were fabricated using the oxidized-only and oxidized followed by functionalization with IA MWCNTs. PET composites fabricated with MWCNT oxidized by mild conditions showed improved tensile strength and failure strain, while harsh MWCNT oxidation render them overly brittle.

  16. Local Field Effects in the Energy Transfer between a Chromophore and a Carbon Nanotube : a Single Nano-compound Investigation.

    OpenAIRE

    Roquelet, Cyrielle; Vialla, Fabien; Diederichs, Carole; Roussignol, Philippe; Delalande, Claude; Deleporte, Emmanuelle; Lauret, Jean-Sébastien; Voisin, Christophe

    2012-01-01

    Energy transfer in non-covalently bound porphyrin / carbon nanotube compounds is investigated at the single nano-compound scale. Excitation spectroscopy of the luminescence of the nanotube shows two resonances arising from intrinsic excitation of the nanotube and from energy transfer from the porphyrin. Polarization diagrams show that both resonances are highly anisotropic with a preferred direction along the tube axis. The energy transfer is thus strongly anisotropic despite the almost isotr...

  17. A highly reproducible solenoid micropump system for the analysis of total inorganic carbon and ammonium using gas-diffusion with conductimetric detection.

    Science.gov (United States)

    Henríquez, Camelia; Horstkotte, Burkhard; Cerdà, Víctor

    2014-01-01

    In this work, a simple, economic, and miniaturized flow-based analyzer based on solenoid micropumps is presented. It was applied to determine two parameters of high environmental interest: ammonium and total inorganic carbon (TIC) in natural waters. The method is based on gas diffusion (GD) of CO₂ and NH3 through a hydrophobic gas permeable membrane from an acidic or alkaline donor stream, respectively. The analytes are trapped in an acceptor solution, being slightly alkaline for CO₂ and slightly acidic for NH₃. The analytes are quantified using a homemade stainless steel conductimetric cell. The proposed system required five solenoid micro-pumps, one for each reagent and sample. Two especially made air bubble traps were placed down-stream of the solendoid pumps, which provided the acceptor solutions, by this increasing the method's reproducibility. Values of RSD lower than 1% were obtained. Achieved limits of detection were 0.27 µmol L⁻¹ for NH₄⁺ and 50 µmol L⁻¹ for TIC. Add-recovery tests were used to prove the trueness of the method and recoveries of 99.5 ± 7.5% were obtained for both analytes. The proposed system proved to be adequate for monitoring purpose of TIC and NH₄⁺ due to its high sample throughput and repeatability. PMID:24274287

  18. Mechanical and electrical properties of novel poly(ether ether ketone)/carbon nanotube/inorganic fullerene-like WS2 hybrid nanocomposites: Experimental measurements and theoretical predictions

    International Nuclear Information System (INIS)

    Highlights: · The mechanical properties of PEEK based hybrid nanocomposites were analyzed. · The composites showed improved stiffness and strength than the neat polymer. · Their Young's modulus was fairly well predicted by simple theoretical models. · The hybrids with high SWCNT content exhibited semiconducting behaviour. · These multifunctional materials are suitable for industrial applications. - Abstract: The mechanical and electrical properties of poly(ether ether ketone) (PEEK) based hybrid nanocomposites incorporating single-walled carbon nanotubes (SWCNTs) and inorganic fullerene-like tungsten disulfide (IF-WS2) nanoparticles have been extensively investigated from both experimental and theoretical point of views. Dynamic mechanical studies revealed a remarkable increase in the storage modulus and glass transition temperature of the matrix by the inclusion of both nanofillers. Moreover, tensile and flexural tests indicated significant enhancements in stiffness and strength, attributed to synergistic reinforcement effects combined with strong PEEK-SWCNT interfacial interactions. The Young's modulus of these nanocomposites was fairly well predicted by simple theoretical models such as the rule of mixtures. The hybrids with SWCNT content equal or higher than 0.5 wt% exhibited semiconducting behaviour and the temperature dependence of their electrical conductivity followed a fluctuation-induced tunnelling model. Enhanced overall performance was found for composites prepared by a single-step melt-blending process compared to those manufactured in two stages. The addition of both nanoreinforcements opens up new opportunities for the development of high-performance multifunctional materials suitable for industrial applications.

  19. The response of inorganic carbon distributions and dynamics to upwelling-favorable winds on the northern Gulf of Mexico during summer

    Science.gov (United States)

    Huang, W.-J.; Cai, W.-J.; Wang, Y.; Hu, X.; Chen, B.; Lohrenz, S. E.; Chakraborty, S.; He, R.; Brandes, J.; Hopkinson, C. S.

    2015-12-01

    Upwelling-favorable winds and an offshore-distributed Mississippi and Atchafalaya River plume trajectory were observed in summer 2009 in contrast to the mean conditions from 2002 to 2010 (upwelling-unfavorable winds and an alongshore river plume trajectory), a set of conditions which was also observed in summer 2007. The responses of dissolved inorganic carbon (DIC) distributions and dynamics to upwelling-favorable winds are studied by comparing the contrasting conditions between summer 2009 and summer 2007 on the northern Gulf of Mexico. Patterns of surface water partial pressure of CO2 (pCO2), DIC, δ13C in DIC, and total alkalinity (TA) determined in July 2009 and August 2007 were strongly related to river plume trajectories, and differed between the two summers. The slope of the relationship between dissolved oxygen (DO) and DIC in summer 2007 was comparable to the Redfield O/C ratio of 1.3, which was attributed to respiration of organic matter in the bottom water. The slope of the DO and DIC relationship and δ13CDIC values in bottom waters during July 2009 were clearly affected by mixing since their salinities were influence on the distribution of coastal currents and plume trajectories and their subsequent impact on biogeochemical processes.

  20. A new strategy for designing high-performance sulfonated poly(ether ether ketone) polymer electrolyte membranes using inorganic proton conductor-functionalized carbon nanotubes

    Science.gov (United States)

    Gong, Chunli; Zheng, Xuan; Liu, Hai; Wang, Guangjin; Cheng, Fan; Zheng, Genwen; Wen, Sheng; Law, Wing-Cheung; Tsui, Chi-Pong; Tang, Chak-Yin

    2016-09-01

    Remarkable progress has been made on the use of polymer electrolyte membranes (PEMs) for renewable-energy-related research. In particular, carbon nanotubes (CNTs) have emerged as versatile nanomaterials to modify PEMs. However, the inert ionic conduction ability and possible short-circuiting risk are the two major obstacles to their further development. In this work, CNTs are firstly functionalized with an inorganic proton conductor, boron phosphate (BPO4), using a facile polydopamine-assisted sol-gel method to yield BPO4@CNTs. This new additive is then used to modify sulfonated poly(ether ether ketone) (SPEEK). Polydopamine coating layer can act as an extraordinary glue to homogeneously adhere BPO4 nanoparticles on CNTs, thereby not only reducing the risk of short-circuiting, but also fabricating new proton-conducting pathways in the composite membranes. A comprehensive characterization reveals that the thermal stability, tensile properties, and dimensional stability of PEMs are significantly improved. Compared with pure SPEEK, the proton conductivity of SPEEK/BPO4@CNTs-2 is improved by 45% and 150% at 20 °C and at 80 °C, respectively. Furthermore, the H2/O2 cell performance of SPEEK/BPO4@CNTs-2 membrane exhibits a peak power density of 340.7 mW cm-2 at 70 °C, which is significantly better than that of pure SPEEK (254.2 mW cm-2), demonstrating the great potential of proton conductors-functionalized CNTs in PEMs.

  1. An Ultrahigh Precision, High-Frequency Dissolved Inorganic Carbon Analyzer Based on Dual Isotope Dilution and Cavity Ring-Down Spectroscopy.

    Science.gov (United States)

    Huang, Kuan; Cassar, Nicolas; Jonsson, Bror; Cai, Wei-jun; Bender, Michael L

    2015-07-21

    We present a novel method for continuous and automated shipboard measurements of dissolved inorganic carbon concentration ([DIC]) in surface water. The method is based on dual isotope dilution and cavity ring-down spectroscopy (DID-CRDS). In this method, seawater is continuously sampled and mixed with a flow of NaH(13)CO3 solution that is also enriched in deuterated water (the spike). The isotopic composition of CO2 (δ(13)C(spiked_sample)) derived from the DIC in the mixture, and the D/H ratio of the mixed water (δD(spiked_sample)), are measured by CRDS analyzers. The D/H of the water in the mixture allows accurate estimates of the mixing ratio of the sample and the spike. [DIC] of the sample is then calculated from the mixing ratio, [DI(13)C] of the spike, and δ(13)C(spiked_sample). In the laboratory, the precision of the method is infrared(NDIR)-based methods (mean difference = -0.9 ± 4.73 μmol kg(-1)). PMID:26119512

  2. Tailoring the Pore Environment of Metal-Organic and Molecular Materials Decorated with Inorganic Anions: Platforms for Highly Selective Carbon Capture

    Science.gov (United States)

    Nugent, Patrick S.

    Due to their high surface areas and structural tunability, porous metal-organic materials, MOMs, have attracted wide research interest in areas such as carbon capture, as the judicious choice of molecular building block (MBB) and linker facilitates the design of MOMs with myriad topologies and allows for a systematic variation of the pore environment. Families of MOMs with modular components, i.e. MOM platforms, are eminently suitable for targeting the selective adsorption of guest molecules such as CO2 because their pore size and pore functionality can each be tailored independently. MOMs with saturated metal centers (SMCs) that promote strong yet reversible CO2 binding in conjunction with favorable adsorption kinetics are an attractive alternative to MOMs containing unsaturated metal centers (UMCs) or amines. Whereas MOMs with SMCs and exclusively organic linkers typically have poor CO2 selectivity, it has been shown that a versatile, long known platform with SMCs, pillared square grids with inorganic anion pillars and pcu topology, exhibits high and selective CO 2 uptake, a moderate CO2 binding affinity, and good stability under practical conditions. As detailed herein, the tuning of pore size and pore functionality in this platform has modulated the CO2 adsorption properties and revealed variants with unprecedented selectivity towards CO 2 under industrially relevant conditions, even in the presence of moisture. With the aim of tuning pore chemistry while preserving pore size, we initially explored the effect of pillar substitution upon the carbon capture properties of a pillared square grid, [Cu(bipy)2(SiF6)] (SIFSIX-1-Cu). Room temperature CO2, CH4, and N 2 adsorption isotherms revealed that substitution of the SiF6 2- ("SIFSIX") inorganic pillar with TiF6 2- ("TIFSIX") or SnF62- ("SNIFSIX") modulated CO2 uptake, CO2 affinity (heat of adsorption, Qst), and selectivity vs. CH4 and N2. TIFSIX-1-Cu and SNIFSIX-1-Cu were calculated to exhibit the highest CO2/N 2

  3. Effect of inorganic inhibitors on the corrosion behavior of 1018 carbon steel in the LiBr + ethylene glycol + H2O mixture

    International Nuclear Information System (INIS)

    The effect of inorganic inhibitors on the corrosion behavior of 1018 carbon steel in the mixture LiBr (55%) + ethylene glycol + H2O at room temperature has been evaluated. Used inhibitors included LiNO3 (Lithium Nitrate), Li2MoO4 (Lithium Molybdate) and Li2CrO4 (Lithium Chromate) at concentrations of 5, 20 and 50 ppm. Electrochemical techniques included potentiodynamic polarization curves, electrochemical noise resistance (EN) and electrochemical impedance spectroscopy (EIS) measurements. Additionally, adsorption isotherms were calculated. The results obtained showed that both, the corrosion rate and the passive current density decreased with inhibitors, and, in general terms, inhibitors efficiency increased with inhibitor concentration, except in the case of Li2CrO4, where the highest efficiency was obtained with 20 ppm of inhibitor. Pitting potential with 5 ppm of inhibitor, regardless its chemical composition, was more active than in absence of inhibitor, increased at 20 ppm, especially with Li2CrO4, and remained unaltered with 50 ppm. EN measurements showed that at 5 ppm of inhibitor, the number of film rupture/repassivation events was higher than that obtained at 20 or 50 ppm. Adsorption isotherms suggested a different adsorption mechanism for each inhibitor, whereas EIS results suggested that the corrosion process when nitrates were added was under charge transfer control, but in the case of molybdates or chromates was under diffusion control

  4. Effect of inorganic inhibitors on the corrosion behavior of 1018 carbon steel in the LiBr + ethylene glycol + H{sub 2}O mixture

    Energy Technology Data Exchange (ETDEWEB)

    Samiento-Bustos, E. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos. Av. Universidad 1001, Col. Chamilpa, CP 62210, Cuernavaca, Morelos (Mexico); Rodriguez, J.G. Gonzalez [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos. Av. Universidad 1001, Col. Chamilpa, CP 62210, Cuernavaca, Morelos (Mexico)], E-mail: ggonzalez@uaem.mx; Uruchurtu, J. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos. Av. Universidad 1001, Col. Chamilpa, CP 62210, Cuernavaca, Morelos (Mexico); Dominguez-Patino, G. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos. Av. Universidad 1001, Col. Chamilpa, CP 62210, Cuernavaca, Morelos (Mexico); U.A.E.M. Facultad de Ciencias Quimicas e Ingenieria, Av. Universidad 1001, 62209, Cuernavaca, Morelos (Mexico); Salinas-Bravo, V.M. [Instituto de Investigaciones Electricas, Gerencia de Materiales y Proceso Quimicos, Av. Reforma 113, Col. Palmira, CP 62490, Cuernavaca, Morelos (Mexico)

    2008-08-15

    The effect of inorganic inhibitors on the corrosion behavior of 1018 carbon steel in the mixture LiBr (55%) + ethylene glycol + H{sub 2}O at room temperature has been evaluated. Used inhibitors included LiNO{sub 3} (Lithium Nitrate), Li{sub 2}MoO{sub 4} (Lithium Molybdate) and Li{sub 2}CrO{sub 4} (Lithium Chromate) at concentrations of 5, 20 and 50 ppm. Electrochemical techniques included potentiodynamic polarization curves, electrochemical noise resistance (EN) and electrochemical impedance spectroscopy (EIS) measurements. Additionally, adsorption isotherms were calculated. The results obtained showed that both, the corrosion rate and the passive current density decreased with inhibitors, and, in general terms, inhibitors efficiency increased with inhibitor concentration, except in the case of Li{sub 2}CrO{sub 4,} where the highest efficiency was obtained with 20 ppm of inhibitor. Pitting potential with 5 ppm of inhibitor, regardless its chemical composition, was more active than in absence of inhibitor, increased at 20 ppm, especially with Li{sub 2}CrO{sub 4}, and remained unaltered with 50 ppm. EN measurements showed that at 5 ppm of inhibitor, the number of film rupture/repassivation events was higher than that obtained at 20 or 50 ppm. Adsorption isotherms suggested a different adsorption mechanism for each inhibitor, whereas EIS results suggested that the corrosion process when nitrates were added was under charge transfer control, but in the case of molybdates or chromates was under diffusion control.

  5. A novel control method for nitritation: The domination of ammonia-oxidizing bacteria by high concentrations of inorganic carbon in an airlift-fluidized bed reactor.

    Science.gov (United States)

    Tokutomi, Takaaki; Shibayama, Chizu; Soda, Satoshi; Ike, Michihiko

    2010-07-01

    A novel nitritation method based on the addition of inorganic carbon (IC) was verified using an airlift-fluidized bed reactor packed with sponge cubes. A continuous-treatment experiment demonstrated that the type of nitrification-nitrite or nitrate accumulation-could be controlled by the addition of different alkalinity sources (NaHCO(3) or NaOH, respectively). The maximum rate of ammonia oxidation at 30 degrees C was 2.47kg-N/(m(3) d), with nitrate formation of less than 0.5% of the converted ammonia. Nitrite accumulation of over 90% was maintained stably over 250 days at 30 degrees C and was achieved even at 19 degrees C. Qualitative and quantitative shifts of nitrifying bacteria in the biofilm were monitored by real-time PCR and T-RFLP analysis. Ammonia-oxidizing bacteria (AOB) were dominant but nitrite-oxidizing bacteria (NOB) were eliminated in the reactor when NaHCO(3) was used as the alkalinity source. From the kinetic data, we inferred that high IC concentrations drive stable nitritation by promoting a higher growth rate for AOB than for NOB. PMID:20554306

  6. Adsorption of volatile sulphur compounds onto modified activated carbons: effect of oxygen functional groups.

    Science.gov (United States)

    Vega, Esther; Lemus, Jesús; Anfruns, Alba; Gonzalez-Olmos, Rafael; Palomar, José; Martin, María J

    2013-08-15

    The effect of physical and chemical properties of activated carbon (AC) on the adsorption of ethyl mercaptan, dimethyl sulphide and dimethyl disulphide was investigated by treating a commercial AC with nitric acid and ozone. The chemical properties of ACs were characterised by temperature programme desorption and X-ray photoelectron spectroscopy. AC treated with nitric acid presented a larger amount of oxygen functional groups than materials oxidised with ozone. This enrichment allowed a significant improvement on adsorption capacities for ethyl mercaptan and dimethyl sulphide but not for dimethyl disulphide. In order to gain a deeper knowledge on the effect of the surface chemistry of AC on the adsorption of volatile sulphur compounds, the quantum-chemical COSMO-RS method was used to simulate the interactions between AC surface groups and the studied volatile sulphur compounds. In agreement with experimental data, this model predicted a greater affinity of dimethyl disulphide towards AC, unaffected by the incorporation of oxygen functional groups in the surface. Moreover, the model pointed out to an increase of the adsorption capacity of AC by the incorporation of hydroxyl functional groups in the case of ethyl mercaptan and dimethyl sulphide due to the hydrogen bond interactions. PMID:23708449

  7. Effect of effluent organic matter on the adsorption of perfluorinated compounds onto activated carbon.

    Science.gov (United States)

    Yu, Jing; Lv, Lu; Lan, Pei; Zhang, Shujuan; Pan, Bingcai; Zhang, Weiming

    2012-07-30

    Effect of effluent organic matter (EfOM) on the adsorption of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) onto powdered activated carbon (PAC) was quantitatively investigated at environmentally relevant concentration levels. The adsorption of both perfluorinated compounds (PFCs) onto PAC followed pseudo-second order kinetics and fitted the Freundlich model well under the given conditions. Intraparticle diffusion was found to be the rate-controlling step in the PFC adsorption process onto PAC in the absence and presence of EfOM. The presence of EfOM, either in PFC-EfOM simultaneous adsorption onto fresh PAC or in PFC adsorption onto EfOM-preloaded PAC, significantly reduced the adsorption capacities and sorption rates of PFCs. The pH of zero point of charge was found to be 7.5 for fresh PAC and 4.2 for EfOM-preloaded PAC, suggesting that the adsorbed EfOM imparted a negative charge on PAC surface. The effect of molecular weight distribution of EfOM on the adsorption of PFCs was investigated with two EfOM fractions obtained by ultrafiltration. The low-molecular-weight compounds (30kDa) had much less effect on PFC adsorption capacity. PMID:22609392

  8. Organic aerosols and inorganic species from post-harvest agricultural-waste burning emissions over northern India: impact on mass absorption efficiency of elemental carbon.

    Science.gov (United States)

    Rajput, Prashant; Sarin, M M; Sharma, Deepti; Singh, Darshan

    2014-01-01

    Atmospheric PM2.5 (particulate matter with aerodynamic diameter of ≤ 2.5 μm), collected from a source region [Patiala: 30.2 °N; 76.3 °E; 250 m above mean sea level] of emissions from post-harvest agricultural-waste (paddy-residue) burning in the Indo-Gangetic Plain (IGP), North India, has been studied for its chemical composition and impact on regional atmospheric radiative forcing. On average, organic aerosol mass accounts for 63% of PM2.5, whereas the contribution of elemental carbon (EC) is ∼3.5%. Sulphate, nitrate and ammonium contribute up to ∼85% of the total water-soluble inorganic species (WSIS), which constitutes ∼23% of PM2.5. The potassium-to-organic carbon ratio from paddy-residue burning emissions (KBB(+)/OC: 0.05 ± 0.01) is quite similar to that reported from Amazonian and Savanna forest-fires; whereas non-sea-salt-sulphate-to-OC ratio (nss-SO4(2-)/OC: 0.21) and nss-SO4(2-)/EC ratio of 2.6 are significantly higher (by factor of 5 to 8). The mass absorption efficiency of EC (3.8 ± 1.3 m(2) g(-1)) shows significant decrease with a parallel increase in the concentrations of organic aerosols and scattering species (sulphate and nitrate). A cross plot of OC/EC and nss-SO4(2-)/EC ratios show distinct differences for post-harvest burning emissions from paddy-residue as compared to those from fossil-fuel combustion sources in south-east Asia. PMID:25124269

  9. Supercritical Carbon Dioxide and Microwave-Assisted Extraction of Functional Lipophilic Compounds from Arthrospira platensis

    Directory of Open Access Journals (Sweden)

    Diego A. Esquivel-Hernández

    2016-05-01

    Full Text Available Arthrospira platensis biomass was used in order to obtain functional lipophilic compounds through green extraction technologies such as supercritical carbon dioxide fluid extraction (SFE and microwave-assisted extraction (MAE. The temperature (T factor was evaluated for MAE, while for SFE, pressure (P, temperature (T, and co-solvent (ethanol (CS were evaluated. The maximum extraction yield of the obtained oleoresin was (4.07% ± 0.14% and (4.27% ± 0.10% for SFE and MAE, respectively. Extracts were characterized by gas chromatography mass spectrometry (GC-MS and gas chromatography flame ionization detector (GC-FID. The maximum contents of functional lipophilic compounds in the SFE and MAE extracts were: for carotenoids 283 ± 0.10 μg/g and 629 ± 0.13 μg/g, respectively; for tocopherols 5.01 ± 0.05 μg/g and 2.46 ± 0.09 μg/g, respectively; and for fatty acids 34.76 ± 0.08 mg/g and 15.88 ± 0.06 mg/g, respectively. In conclusion, the SFE process at P 450 bar, T 60 °C and CS 53.33% of CO2 produced the highest yield of tocopherols, carotenoids and fatty acids. The MAE process at 400 W and 50 °C gives the best extracts in terms of tocopherols and carotenoids. For yield and fatty acids, the MAE process at 400 W and 70 °C produced the highest values. Both SFE and MAE showed to be suitable green extraction technologies for obtaining functional lipophilic compounds from Arthrospira platensis.

  10. Supercritical Carbon Dioxide and Microwave-Assisted Extraction of Functional Lipophilic Compounds from Arthrospira platensis

    Science.gov (United States)

    Esquivel-Hernández, Diego A.; López, Víctor H.; Rodríguez-Rodríguez, José; Alemán-Nava, Gibrán S.; Cuéllar-Bermúdez, Sara P.; Rostro-Alanis, Magdalena; Parra-Saldívar, Roberto

    2016-01-01

    Arthrospira platensis biomass was used in order to obtain functional lipophilic compounds through green extraction technologies such as supercritical carbon dioxide fluid extraction (SFE) and microwave-assisted extraction (MAE). The temperature (T) factor was evaluated for MAE, while for SFE, pressure (P), temperature (T), and co-solvent (ethanol) (CS) were evaluated. The maximum extraction yield of the obtained oleoresin was (4.07% ± 0.14%) and (4.27% ± 0.10%) for SFE and MAE, respectively. Extracts were characterized by gas chromatography mass spectrometry (GC-MS) and gas chromatography flame ionization detector (GC-FID). The maximum contents of functional lipophilic compounds in the SFE and MAE extracts were: for carotenoids 283 ± 0.10 μg/g and 629 ± 0.13 μg/g, respectively; for tocopherols 5.01 ± 0.05 μg/g and 2.46 ± 0.09 μg/g, respectively; and for fatty acids 34.76 ± 0.08 mg/g and 15.88 ± 0.06 mg/g, respectively. In conclusion, the SFE process at P 450 bar, T 60 °C and CS 53.33% of CO2 produced the highest yield of tocopherols, carotenoids and fatty acids. The MAE process at 400 W and 50 °C gives the best extracts in terms of tocopherols and carotenoids. For yield and fatty acids, the MAE process at 400 W and 70 °C produced the highest values. Both SFE and MAE showed to be suitable green extraction technologies for obtaining functional lipophilic compounds from Arthrospira platensis. PMID:27164081

  11. Compound specific radiocarbon analyses to apportion sources of combustion products in sedimentary pyrogenic carbon deposits

    Science.gov (United States)

    Hanke, Ulrich M.; Schmidt, Michael W. I.; McIntyre, Cameron P.; Reddy, Christopher M.; Wacker, Lukas; Eglinton, Timothy I.

    2016-04-01

    Pyrogenic carbon (PyC) is a collective term for carbon-rich residues comprised of a continuum of products generated during biomass burning and fossil fuel combustion. PyC is a key component of the global carbon cycle due to its slow intrinsic decomposition rate and its ubiquity in the environment. It can originate from natural or anthropogenic vegetation fires, coal mining, energy production, industry and transport. Subsequently, PyC can be transported over long distances by wind and water and can eventually be buried in sediments. Information about the origin of PyC (biomass burning vs. fossil fuel combustion) deposited in estuarine sediments is scarce. We studied the highly anoxic estuarine sediments of the Pettaquamscutt River (Rhode Island, U.S.) in high temporal resolution over 250 years and found different combustion proxies reflect local and regional sources of PyC (Hanke et al. in review; Lima et al. 2003). The polycyclic aromatic hydrocarbons (PAH) originate from long-range atmospheric transport, whereas bulk PyC, detected as benzene polycarboxylic acids (BPCA), mainly stems from local catchment run-off. However, to unambiguously apportion PyC sources, we need additional information, such as compound specific radiocarbon (14C) measurements. We report 14C data for individual BPCA including error analysis and for combustion-related PAH. First results indicate that biomass burning is the main source of PyC deposits, with additional minor contributions from fossil fuel combustion. References Hanke U.M., T.I. Eglinton, A.L.L. Braun, C. Reddy, D.B. Wiedemeier, M.W.I. Schmidt. Decoupled sedimentary records of combustion: causes and implications. In review. Lima, A. L.; Eglinton, T. I.; Reddy, C. M., High-resolution record of pyrogenic polycyclic aromatic hydrocarbon deposition during the 20th century. ES&T, 2003, 37 (1), 53-61.

  12. Carbon nanostructures as catalytic support for chemiluminescence of sulfur compounds in a molecular emission cavity analysis system.

    Science.gov (United States)

    Safavi, Afsaneh; Maleki, Norouz; Doroodmand, Mohammad Mahdi; Koleini, Mohammad Mehdi

    2009-06-30

    The effect of different substrates including stainless steel, activated carbon, single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), fullerenes (C60, C70, etc.) and SWCNTs doped with iron and palladium nanoparticles were compared for catalytic chemiluminescence reaction of sulfur compounds in a flame-containing cavity of molecular emission cavity analysis (MECA) system. Different forms of CNT substrates were fabricated using electric arc-discharge method. The blue emission of excited S2 was monitored using a CCD camera. The results demonstrate that, due to the high surface area, plenty of basal planes, high thermal conductivity, and high flexibility of the carbon nanostructure as appropriate support, carbon nanostructures play an important role in catalytic chemiluminescence emission of sulfur compounds in MECA. Moreover, the presence of metallic nanoparticles doped on carbon nanostructures enhances their catalytic effect. The results revealed that under similar conditions, SWCNTs/Pd doped nanoparticles, SWCNTs/Fe doped nanoparticles, SWCNTs, MWCNTs and fullerenes have the most catalytic effects on chemiluminescence of sulfur compounds, respectively. PMID:19463563

  13. Potentiometric and spectrophotometric study of the stability of magnesium carbonate and bicarbonate ion pairs to 150 °C and aqueous inorganic carbon speciation and magnesite solubility

    Science.gov (United States)

    Stefánsson, Andri; Bénézeth, Pascale; Schott, Jacques

    2014-08-01

    The formation constants of magnesium bicarbonate and carbonate ion pairs have been experimentally determined in dilute hydrothermal solutions to 150 °C. Two experimental approaches were applied, potentiometric acid-base titrations at 10-60 °C and spectrophotometric pH measurements using two pH indicators, 2-naphthol and 4-nitrophenol, at 25 and 80-150 °C. At a given temperature, the first and second ionization constants of carbonic acid (K1, K2) and the ion pair formation constants for MgHCO3+(aq) (KMgHCO3+) and MgCO3(aq) (KMgCO3) were simultaneously fitted to the data. Results of this study compare well with previously determined values of K1 and K2. The formation constants of MgHCO3+(aq) and MgCO3(aq) ion pairs increased significantly with increasing temperature, with values of logKMgHCO3+ = 1.14 and 1.75 and of logKMgCO3 = 2.86 and 3.48 at 10 °C and 100 °C, respectively. These ion pairs are important aqueous species under neutral to alkaline conditions in moderately dilute to concentrated Mg-containing solutions, with MgCO3(aq) predominating over CO32-(aq) in solutions at pH >8. The predominance of magnesium carbonate over carbonate is dependent on the concentration of dissolved magnesium and the ratio of magnesium over carbonate. With increasing temperature and at alkaline pH, brucite solubility further reduced the magnesium concentration to levels below 1 mmol kg-1, thus limiting availability of Mg2+(aq) for magnesite precipitation.

  14. Inorganic Constituents in Coal

    Directory of Open Access Journals (Sweden)

    Rađenović A.

    2006-02-01

    Full Text Available Coal contains not only organic matter but also small amounts of inorganic constituents. More thanone hundred different minerals and virtually every element in the periodic table have been foundin coal. Commonly found group minerals in coal are: major (quartz, pyrite, clays and carbonates,minor, and trace minerals. Coal includes a lot of elements of low mass fraction of the orderof w=0.01 or 0.001 %. They are trace elements connected with organic matter or minerals comprisedin coal. The fractions of trace elements usually decrease when the rank of coal increases.Fractions of the inorganic elements are different, depending on the coal bed and basin. A varietyof analytical methods and techniques can be used to determine the mass fractions, mode ofoccurrence, and distribution of organic constituents in coal. There are many different instrumentalmethods for analysis of coal and coal products but atomic absorption spectroscopy – AAS is theone most commonly used. Fraction and mode of occurrence are one of the main factors that haveinfluence on transformation and separation of inorganic constituents during coal conversion.Coal, as an important world energy source and component for non-fuels usage, will be continuouslyand widely used in the future due to its relatively abundant reserves. However, there is aconflict between the requirements for increased use of coal on the one hand and less pollution onthe other. It’s known that the environmental impacts, due to either coal mining or coal usage, canbe: air, water and land pollution. Although, minor components, inorganic constituents can exert asignificant influence on the economic value, utilization, and environmental impact of the coal.

  15. Utilização da múltipla voltametria de onda quadrada na determinação eletroanalítica de compostos orgânicos e inorgânicos Use of the multiple square wave voltammetry in the electroanalytical determination of organic and inorganic compounds

    Directory of Open Access Journals (Sweden)

    Djenaine De Souza

    2007-04-01

    Full Text Available This paper reports the development of multiple square wave voltammetry and the possibilities of its use for electroanalytical determinations of organic and inorganic compounds with the improvement of the signal-to-noise ratios and detection limits 2-3 orders of magnitude lower than those obtained with conventional square wave voltammetry. The theoretical aspects and analytical applications were demonstrated as an increased analytical response (current and application of different pulse modes for different redox processes. Preliminary results obtained for several redox systems using different electrode surfaces are shown, demonstrating also that MSWV represents an excellent alternative for the determination of ultra-traces of organic and inorganic compounds.

  16. Improvement of visible light-induced photocatalytic performance by Cr-doped SrTiO3-carbon nitride intercalation compound (CNIC) composite

    Institute of Scientific and Technical Information of China (English)

    杨明; 金效齐

    2016-01-01

    Novel organic−inorganic composite photocatalyst offers new opportunities in the practical applications of photocatalysis. Novel visible light-induced Cr-doped SrTiO3–carbon nitride intercalation compound (CNIC) composite photocatalysts were synthesized. The composite photocatalyst was characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared (FT-IR) spectroscopy, UV-vis diffuse reflection spectroscopy, photoluminescence (PL) spectroscopy, and BET surface area analyzer. The photocatalytic oxidation ability of the novel composite photocatalyst was evaluated using methyl orange (MO) as a target pollutant. The photocatalysts exhibited a significantly enhanced photocatalytic performance in degrading MO. For maximizing the photodegradation activity of the composite photocatalysts, the optimal CNIC content was determined. The improved photocatalytic activity of the as-prepared Cr-doped SrTiO3–CNIC composite photocatalyst may be attributed to the enhancement of photo-generated electron–hole separations at the interface.

  17. A radiocarbon-based inventory of methane and inorganic carbon dissolved in surface lake waters in arctic Alaska, USA

    Science.gov (United States)

    Czimczik, Claudia; Clayton, Elder; Xu, Xiaomei; Lehman, Jennifer; Townsend-Small, Amy

    2014-05-01

    Major uncertainties in land-atmosphere carbon (C) exchange in the rapidly warming and wetting Arctic are 1) the magnitude and timing of net losses of ancient permafrost C to the atmosphere and 2) the relative changes of C exchange as carbon dioxide (CO2) or the more powerful greenhouse gas methane (CH4). For CH4, the role of diffusive fluxes versus plant-mediated and ebullition fluxes is poorly constrained. Radiocarbon (14C) is a unique tracer for distinguishing ancient permafrost C from C rapidly cycling between the land and atmosphere. In addition, stable isotope ratios (13C/12C and D/H) provide insight to trace gas production and consumption pathways. Previous measurements, however, have focused on CH4 from ebullition fluxes due to technical and logistical challenges in 14C-CH4 analysis. We quantified the 14C content and δ13C signatures of dissolved CH4 and DIC in lake surface waters along a north-south transect on the North Slope of Alaska, USA (69.9°N to 71.28°N, -156.12°W to -156.32°W). Samples were collected at the end of winter before ice break-up (April 2013) and during summer (August 2012 & 2013) in 1 L bottles. A subset of samples was also analyzed for CH4 and CO2 concentrations and stable isotope ratios by the Circumarctic Lakes Observation Network (CALON). In addition, in August 2013, we measured the 14C content and δ13C ratios of lake-atmosphere CH4 and CO2 exchange near Barrow, AK, USA (71°N, -156°W). We obtained dissolved CH4 and CO2 sufficient for 14C analysis from lakes with concentrations as low as 0.01 mg C /L) using a novel, in situ preconcentration method (liqui-cel, Membrana). And, we measured and collected isoflux samples of simulated, near-shore ebulltion-derived CH4 and CO2 using floating headspace chambers. Isotope samples were processed using a novel, flow-through vacuum line and analyzed at the KCCAMS facility at the University of California, Irvine, USA with accelerator (0.5MV 1.5SDH-2, National Electrostatics Corporation) and

  18. Synthesis of inorganic materials in a supercritical carbon dioxide medium. Application to ceramic cross-flow filtration membranes preparation

    International Nuclear Information System (INIS)

    Membrane separations, using cross-flow mineral ceramic membranes, allows fractionation of aqueous solutions due to the molecular sieve effect and electrostatic charges. To obtain a high selectivity, preparation of new selective ceramic membranes is necessary. We propose in this document two different routes to prepare such cross-flow tubular mineral membranes. In the first exposed method, a ceramic material is used, titanium dioxide, synthesized in supercritical carbon dioxide by the hydrolysis of an organometallic precursor of the oxide. The influence of operating parameters is similar to what is observed during a liquid-phase synthesis (sol-gel process), and leads us to control the size and texture of the prepared particles. This material is then used to prepare mineral membrane with a compressed layer process. The particles are mixed with organic components to form a liquid suspension. A layer is then deposited on the internal surface of a tubular porous support by slip-casting. The layer is then dried and compressed on the support before sintering. The obtained membranes arc in the ultrafiltration range. A second process has been developed in this work. It consists on the hydrolysis, in a supercritical CO2 medium, of a precursor of titanium dioxide infiltrated into the support. The obtained material is then both deposited on the support but also infiltrated into the porosity. This new method leads to obtain ultrafiltration membranes that retain molecules which molecular weight is round 4000 g.mol-1. Furthermore, we studied mass transfer mechanisms in cross-flow filtration of aqueous solutions. An electrostatic model, based on generalized Nernst-Planck equation that takes into account electrostatic interactions between solutes and the ceramic material, lead us to obtain a good correlation between experimental results and the numerical simulation. (author)

  19. The synthesis, characterization and optical properties of Si4+ and Pr4+ doped Y6 MoO12 compounds: environmentally benign inorganic pigments with high NIR reflectance

    International Nuclear Information System (INIS)

    Full text: Much interest has attended roofing materials with high solar reflectance and high thermal emittance, so that interiors stay cool, thereby reducing the demand for air conditioned buildings. The heat producing region of the infrared radiations ranges from 700-1100 nm. Replacing conventional pigments with 'cool pigments' that absorb less NIR radiation can provide coatings similar in color to that of conventional roofing materials, but with higher solar reflectance. NIR reflective pigments have been used in the military, construction, plastics and ink industries. Complex inorganic pigments based on mixed metal oxides (eg., chromium green, cobalt blue, cadmium stannate, lead chromate, cadmium yellow and chrome titanate yellow), which have been used in camouflage, absorb visible light but reflect the NIR portion of incident radiation. However, many of these pigments are toxic and there is a need to develop novel colored, NIR-reflecting inorganic pigments that are less hazardous to the environment. In this work, a series of NIR reflective colored pigments of formula Y6-xMxMoO12+δ (where M Si4+ or Pr4+ and x ranges from 0 to 1.0) were synthesized by traditional solid-state route and applied to asbestos cement roofing material so as to evaluate their use as 'cool pigments'. The phase purity of the calcined pigment samples were determined using powder X-ray diffraction. The diffuse reflectance of the powdered pigment samples were measured using a UV-Vis-NIR Spectrometer. The Lab color coordinates were evaluated by CIE 1976 color scale. Replacing Si4+ for Y3+ in Y6MoO12 changed the color from light-yellow to dark-yellow and the band gap decreased from 2.60 to 2.45 eV due to O2p-Mo4d charge transfer transitions. In contrast, replacing Pr4+ for Y3+ changed the color from light yellow to dark brown and the band gap shifted from 2.60 to 1.90 eV. The coloring mechanism is based on the introduction of an additional 4f1 electron energy level of Pr4+ between the valence

  20. Inorganic Carbon Utilization in Some Marine Phytoplankton Species%海洋浮游藻类无机碳利用机理的研究

    Institute of Scientific and Technical Information of China (English)

    缪晓玲; 吴庆余

    2002-01-01

    In order to learn the ways and possible utilization mechanisms of dissolved inorganic carbon (DIC) in marine phytoplankton species under carbon-replete or -limited conditions, the activity of extracellular carbonic anhydrase (CA) was assayed in different pH, CO2 and DIC concentrations. Extracellular CA in Amphidinium carterae and Prorocentrum minimum was detected under carbon-replete conditions, while in Melosira sp., Phaeodactylum tricornutum, Skeletonema costatum, Thalassiosira rotula, Emiliania huxleyi and Pleurochrysis carterae, CA activity was assayed under conditions of carbon limitation. No CA activity was found even under carbon-limited conditions in Chaetoceros compressus, Glenodinium foliaceum, Coccolithus pelagicus, Gephrocapsa oceanica and Heterosigma akashiwo. In species without extracellular CA activity, the direct HCO-3 uptake was investigated using a pH drift technique and the anion exchange inhibitor 4′4′-diisothiocyanatostilbene-2,2-disulfonic acid (DIDS) in a closed system. The result showed that direct HCO-3 transport might occur by an anion exchange mechanism in species Coc. pelagicus and G. oceanica. Of the 13 species investigated, only H. akashiwo did not have the potential for direct uptake or extracellular CA-catalyzed HCO-3 utilization.%为了认识海洋浮游藻类在碳充足和碳受限条件下对水体中溶解无机碳(DIC)的利用方式与可能机理,对13种海洋浮游藻类在不同pH和CO2浓度及不同DIC条件下细胞外碳酸酐酶(CA)的活性进行了分析测定.结果显示:13种藻中,只有Amphidinium carterae和Prorocentrum minimum在碳充足条件下具细胞外CA活性.Melosira sp.、Phaeodactylum tricornutum、Skeletonema costatum、Thalassiosira rotula、Emiliania huxleyi和Pleurochrysis carterae则在碳受限条件下才具细胞外CA活性.Chaetoceros compressus、Glenodinium foliaceum、Coccolithus pelagicus、 Gephrocapsa oceanica和Heterosigma akashiwo即使在碳受限条件下也未检测到细

  1. Science Update: Inorganic Chemistry.

    Science.gov (United States)

    Rawls, Rebecca

    1981-01-01

    Describes areas of inorganic chemistry which have changed dramatically in the past year or two, including photochemistry, electrochemistry, organometallic complexes, inorganic reaction theory, and solid state chemistry. (DS)

  2. Activation of the carbon-fluorine bonds in coordination compounds; Activacion de enlaces carbon-fluor en compuestos de coordinacion

    Energy Technology Data Exchange (ETDEWEB)

    Torrens, H. [Universidad Nacional Autonoma de Mexico, Facultad de Quimica, 04510 Mexico D.F. (Mexico)

    2000-07-01

    Activation of the carbon-fluorine bond is of upmost importance in several chemical processes. In search of synthetic alternatives to promote C-F bond cleavage in arylic systems, several square planar palladium and platinum compounds bearing fluorothiolates and fluorophosphines have been studied. In this paper molecular structures are shown for the following compounds trans-((SC{sub 6}F{sub 5})(P(C{sub 6}F{sub 5}){sub 2}(C{sub 6}H{sub 5}))(Pd({mu}-SC{sub 6}F{sub 5}){sub 2} Pd(SC{sub 6}F{sub 5})(P(C{sub 6}F{sub 5}){sub 2} (C{sub 6}H{sub 5})), cis ((SC{sub 6}F{sub 5}) P(C{sub 6}F{sub 5}){sub 2} (C{sub 6}H{sub 5}) Pt({mu}-SC{sub 6}F{sub 5}){sub 2} Pt(SC{sub 6}F{sub 5}) P(C{sub 6}F{sub 5}){sub 2} (C{sub 6}H{sub 5})), trans Pd ({mu}-SC{sub 6}F{sub 5}){sub 2} Pt(SC{sub 6}F{sub 5})(P(C{sub 6}F{sub 5})(C{sub 6}H{sub 5}){sub 2})), Pt (SC{sub 6}F{sub 5}){sub 2} (C{sub 6}F{sub 5}SC{sub 6}F{sub 4} P(C{sub 6}H{sub 5}){sub 2}))((SC{sub 6}F{sub 5}){sub 2} Pt ({mu}-(SC{sub 6}F{sub 5}){sub 2} Pt(SC{sub 6}F{sub 5}){sub 2}){sup 2-} , (SC{sub 6}HF{sub 4}){sub 2} Pt({mu}-SC{sub 6}HF{sub 4}){sub 2} Pt(SC{sub 6}HF{sub 4}){sub 2}){sup 2-} and ((SC{sub 6}F{sub 4}CF{sub 3}-4){sub 2} Pt (SC{sub 6}F{sub 4}CF{sub 3}-4){sub 2}){sup 2-} . (Author)

  3. Inorganic Sunscreens

    International Nuclear Information System (INIS)

    Inorganic sunscreens, based on TiO2 and ZnO, are a rapidly growing segment of the overall UV protection market. They offer the advantages of high SPF, broad-spectrum coverage and reduced potential irritancy to users. Lack of transparency has traditionally been a drawback regarding acceptance of these products. Recent development work has therefore prioritised the achievement of transparency through superior control of particle size, shape and particle size distribution. The properties of TiO2 and ZnO are discussed as sunscreen actives, and the key factors affecting efficacy and cosmetic elegance. The pros and cons of different product forms (powders and dispersions) are discussed. physical sunscreens can be used either as the sole active in a formulation, or in combination with each other or with organic sunscreens; the relative benefits of these approaches are assessed. The paper concludes with a review of work undertaken to achieve transparency along with developments to improve efficacy (SPF and UVA coverage) and photostability. (author)

  4. Inorganic Sunscreens

    Energy Technology Data Exchange (ETDEWEB)

    Dransfield, G.P

    2000-07-01

    Inorganic sunscreens, based on TiO{sub 2} and ZnO, are a rapidly growing segment of the overall UV protection market. They offer the advantages of high SPF, broad-spectrum coverage and reduced potential irritancy to users. Lack of transparency has traditionally been a drawback regarding acceptance of these products. Recent development work has therefore prioritised the achievement of transparency through superior control of particle size, shape and particle size distribution. The properties of TiO{sub 2} and ZnO are discussed as sunscreen actives, and the key factors affecting efficacy and cosmetic elegance. The pros and cons of different product forms (powders and dispersions) are discussed. physical sunscreens can be used either as the sole active in a formulation, or in combination with each other or with organic sunscreens; the relative benefits of these approaches are assessed. The paper concludes with a review of work undertaken to achieve transparency along with developments to improve efficacy (SPF and UVA coverage) and photostability. (author)

  5. Analysis of hydrogen, carbon, sulfur and volatile compounds in (U{sub 3}Si{sub 2} - Al) nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Sergio C.; Redigolo, Marcelo M.; Amaral, Priscila O.; Leao, Claudio; Oliveira, Glaucia A.C. de; Bustillos, Oscar V., E-mail: ovega@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Uranium silicide U{sub 3}Si{sub 2} is used as nuclear fuel in the research nuclear reactor IEA-R1 at IPEN/CNEN, Sao Paulo, Brazil. The U{sub 3}Si{sub 2} is dispersed in aluminum reaching high densities of uranium in the nucleus of the fuel, up to 4.8 gU cm{sup -3}. This nuclear fuel must comply with a quality control, which includes analysis of hydrogen, carbon and sulfur for the U{sub 3}Si{sub 2} and volatile compound for the aluminum. Hydrogen, carbon and sulfur are analyzed by the method of Radio Frequency gas extraction combustion coupled with Infrared detector. Volatile compounds are analyzed by the method of heated gas extraction coupled with gravimetric measurement. These methods are recommended by the American Society for Testing Materials (ASTM) for nuclear materials. The average carbon and sulfur measurements are 30 μg g{sup -1} and 3 μg g{sup -1}, respectively, and 40 μg g{sup -1} for volatile compounds. The hydrogen analyzer is a TCHEN 600 LECO, carbon and sulfur analyzer is a CS 244 LECO and the volatile compounds analyzer is a home-made apparatus that use a resistant furnace, a gas pipe measurement and a glove-box with controlled atmosphere where an analytical balance has been installed, this analyzer was made at IPEN laboratory. (author)

  6. Dissolved inorganic carbon, total alkalinity, pH, phosphate, dissolved oxygen, and other variables collected from surface discrete observations using Niksin bottle and other instruments from R/V Sultana in the southwest coast of Puerto Rico from 2009-01-05 to 2016-02-01 (NCEI Accession 0145164)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This time series dataset includes weekly and bi-weekly discrete seawater samples of pH and total alkalinity, dissolved inorganic carbon, phosphates and profile...

  7. Dissolved inorganic carbon, total alkalinity, temperature, salinity and other variables collected from profile and discrete sample observations using CTD, Niskin bottle, and other instruments from R/V HI'IALAKAI and OSCAR ELTON SETTE in the U.S. Pacific Reefs from 2012-03-02 to 2014-05-05 (NCEI Accession 0131502)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains data from samples collected and analyzed for total alkalinity (TA) and dissolved inorganic carbon (DIC). From these constituents,...

  8. Welcome to Inorganics: A New Open Access, Inclusive Forum for Inorganic Chemistry

    Directory of Open Access Journals (Sweden)

    Duncan H. Gregory

    2013-06-01

    Full Text Available One of the beauties of inorganic chemistry is its sheer diversity. Just as chemistry sits at the centre of the sciences, inorganic chemistry sits at the centre of chemistry itself. Inorganic chemists are fortunate in having the entire periodic table at their disposal, providing a palette for the creation of a multitude of rich and diverse compounds and materials from the simplest salts to the most complex of molecular species. It follows that the language of inorganic chemistry can thus be a demanding one, accommodating sub-disciplines with very different perspectives and frames of reference. One could argue that it is the unequivocal breadth of inorganic chemistry that empowers inorganic chemists to work at the interfaces, not just between the traditional Inorganic-Organic-Physical boundaries of the discipline, but in the regions where chemistry borders the other physical and life sciences, engineering and socio-economics. [...

  9. Photocatalytic and chemical oxidation of organic compounds in supercritical carbon dioxide. 1998 annual progress report

    International Nuclear Information System (INIS)

    'This report summarizes the results of work done during the first 1.3 years of a three year project. During the first nine months effort focussed on the design, construction and testing of a closed recirculating system that can be used to study photochemistry in supercritical carbon dioxide at pressures up to 5,000 psi and temperatures up to about 50 C. This was followed by a period of work in which the photocatalytic oxidation of benzene and acetone in supercritical, liquid, and gaseous carbon dioxide containing dissolved oxygen was demonstrated. The photocatalyst was titanium dioxide supported on glass spheres. This was the first time it was possible to observe photocatalytic oxidation in a supercritical fluid and to compare reaction in the three fluid phases of a solvent. This also demonstrated that it is possible to purify supercritical and liquid carbon dioxide using photochemical oxidation with no chemical additions other than oxygen. The oxidation of benzene produced no intermediates detectable using on line spectroscopic analysis or by gas chromatographic analysis of samples taken from the flow system. The catalyst surface did darken as the reaction proceeded indicating that oxidation products were accumulating on the surface. This is analogous to the behavior of aromatic compounds in air phase photocatalytic oxidation. The reaction of acetone under similar conditions resulted in the formation of low levels of by-products. Two were identified as products of the reaction of acetone with itself (4-methyl-3-penten-2-one and 4-hydroxy-4-methyl-2-pentanone) using gas chromatography with a mass spectrometer detector. Two other by-products also appear to be from the self-reaction of acetone. By-products of this type had not been observed in prior studies of the gas-phase photocatalytic oxidation of acetone. The by-products that have been observed can also be oxidized under the treatment conditions. The above results establish that photocatalytic oxidation of

  10. Adsorption of volatile sulphur compounds onto modified activated carbons: Effect of oxygen functional groups

    International Nuclear Information System (INIS)

    Highlights: • HNO3 oxidation incorporates a higher amount of functionalities than O3 oxidation. • The loss of porosity is compensated by the massive incorporation of oxygen groups. • HNO3 oxidation increases OH groups in AC and the ETM and DMS adsorption capacities. • The oxygen functional groups in the AC surface did not affect the DMDS adsorption. • COSMO-RS predicts the important role of OH groups for VSC adsorption. -- Abstract: The effect of physical and chemical properties of activated carbon (AC) on the adsorption of ethyl mercaptan, dimethyl sulphide and dimethyl disulphide was investigated by treating a commercial AC with nitric acid and ozone. The chemical properties of ACs were characterised by temperature programme desorption and X-ray photoelectron spectroscopy. AC treated with nitric acid presented a larger amount of oxygen functional groups than materials oxidised with ozone. This enrichment allowed a significant improvement on adsorption capacities for ethyl mercaptan and dimethyl sulphide but not for dimethyl disulphide. In order to gain a deeper knowledge on the effect of the surface chemistry of AC on the adsorption of volatile sulphur compounds, the quantum-chemical COSMO-RS method was used to simulate the interactions between AC surface groups and the studied volatile sulphur compounds. In agreement with experimental data, this model predicted a greater affinity of dimethyl disulphide towards AC, unaffected by the incorporation of oxygen functional groups in the surface. Moreover, the model pointed out to an increase of the adsorption capacity of AC by the incorporation of hydroxyl functional groups in the case of ethyl mercaptan and dimethyl sulphide due to the hydrogen bond interactions

  11. Carbon based secondary compounds do not provide protection against heavy metal road pollutants in epiphytic macrolichens.

    Science.gov (United States)

    Gauslaa, Yngvar; Yemets, Olena A; Asplund, Johan; Solhaug, Knut Asbjørn

    2016-01-15

    Lichens are useful monitoring organisms for heavy metal pollution. They are high in carbon based secondary compounds (CBSCs) among which some may chelate heavy metals and thus increase metal accumulation. This study quantifies CBSCs in four epiphytic lichens transplanted for 6months on stands along transects from a highway in southern Norway to search for relationships between concentrations of heavy metals and CBSCs along a gradient in heavy metal pollutants. Viability parameters and concentrations of 21 elements including nutrients and heavy metals in these lichen samples were reported in a separate paper. Medullary CBSCs in fruticose lichens (Ramalina farinacea, Usnea dasypoga) were reduced in the most polluted sites, but not in foliose ones (Parmelia sulcata, Lobaria pulmonaria), whereas cortical CBSC did not change with distance from the road in any species. Strong positive correlations only occurred between the major medullary compound stictic acid present in L. pulmonaria and most heavy metals, consistent with a chelating role of stictic acid, but not of other studied CBSCs or in other species. However, heavy metal chelating did not protect L. pulmonaria against damage because this species experienced the strongest reduction in viability in the polluted sites. CBSCs with an accumulation potential for heavy metals should be quantified in lichen biomonitoring studies of heavy metals because they, like stictic acid, could overshadow pollutant inputs in some species rendering biomonitoring data less useful. In the two fruticose lichen species, CBSCs decreased with increasing heavy metal concentration, probably because heavy metal exposure impaired secondary metabolism. Thus, we found no support for a heavy metal protection role of any CBSCs in studied epiphytic lichens. No intraspecific relationships occurred between CBSCs versus N or C/N-ratio. Interspecifically, medullary CBSCs decreased and cortical CBSCs increased with increasing C/N-ratio. PMID:26437350

  12. An accurate benchmark description of the interactions between carbon dioxide and polyheterocyclic aromatic compounds containing nitrogen.

    Science.gov (United States)

    Li, Sicheng; Smith, Daniel G A; Patkowski, Konrad

    2015-07-01

    We assessed the performance of a large variety of modern density functional theory approaches for the adsorption of carbon dioxide on molecular models of pyridinic N-doped graphene. Specifically, we selected eight polyheterocyclic aromatic compounds ranging from pyridine and pyrazine to 1,6-diazacoronene and investigated their complexes with CO2 for a large range of intermolecular distan