INFLUENCE OF INORGANIC COMPOUNDS ON THE PROCESS OF PHOTOCATALYSIS OF BIOLOGICALLY ACTIVE COMPOUNDS

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Edyta Kudlek

2017-07-01

Full Text Available Constant increase in concentration of organic micropollutants in the water environment influences the development of methods for their effective elimination from various matrices released into aquatic ecosystems. One of widely described in literature processes for the decomposition of hardly-biodegradable pollutants is the process of heterogeneous photocatalysis. The paper presents the influence of inorganic substances on the decomposition of polycyclic aromatic hydrocarbons (anthracene and benzo[a]pyrene, industrial admixtures - octylphenol and pharmaceutical compounds - diclofenac in the photocatalysis process conducted in the presence of TiO2. It has been shown that the presence of Cl- ions did not affect the photochemical reaction of the micropollutant decomposition. Whereas, the presence of CO3(2-, SO4(2- and HPO4(2- ions inhibited the decolonization of octylphenol and diclofenac, while the degradation efficiency of anthracene and benzo[a]pyrene was reduced only by the presence of CO3(2- and HCO3- anions. The photooxidation of micropollutants in solutions containing Al(3+ oraz Fe(3+ cations proceeded with a much lower efficiency than that for solution without inorganic compounds. The analysis of the kinetics of the photocatalytic decomposition of selected micropollutants show a decrease in the reaction rate constant and an increase in their half-life due to the blocking of theactive semiconductor centers by inorganic compounds. In addition,the toxicological analysis inducated the generation of micropollutant oxidation by-products, which aggravate the quality of treated aqueous solutions.

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.

Comparison of CO(2) and bicarbonate as inorganic carbon sources for triacylglycerol and starch accumulation in Chlamydomonas reinhardtii.

Science.gov (United States)

Gardner, Robert D; Lohman, Egan; Gerlach, Robin; Cooksey, Keith E; Peyton, Brent M

2013-01-01

Microalgae are capable of accumulating high levels of lipids and starch as carbon storage compounds. Investigation into the metabolic activities involved in the synthesis of these compounds has escalated since these compounds can be used as precursors for food and fuel. Here, we detail the results of a comprehensive analysis of Chlamydomonas reinhardtii using high or low inorganic carbon concentrations and speciation between carbon dioxide and bicarbonate, and the effects these have on inducing lipid and starch accumulation during nitrogen depletion. High concentrations of CO(2) (5%; v/v) produced the highest amount of biofuel precursors, transesterified to fatty acid methyl esters, but exhibited rapid accumulation and degradation characteristics. Low CO(2) (0.04%; v/v) caused carbon limitation and minimized triacylglycerol (TAG) and starch accumulation. High bicarbonate caused a cessation of cell cycling and accumulation of both TAG and starch that was more stable than the other experimental conditions. Starch accumulated prior to TAG and then degraded as maximum TAG was reached. This suggests carbon reallocation from starch-based to TAG-based carbon storage. Copyright © 2012 Wiley Periodicals, Inc.

BIOGENIC VS. ABIOGENIC ISOTOPE SIGNATURES OF REDUCED CARBON COMPOUNDS: A LESSON FROM HYDROTHERMAL SYNTHESIS EXPERIMENTS

International Nuclear Information System (INIS)

Horita, J.

2001-01-01

With growing interest in and demonstrated cases of inorganic hydrothermal synthesis of reduced or organic carbon compounds from CO and CO(sub 2), it becomes crucial to establish geochemical criteria to distinguish reduced/organic carbon compounds of abiogenic origin from those of biogenic origin with overwhelming abundances on the surface and in subsurface of the Earth. Chemical and isotopic compositions, particularly(sup 13)C/(sup 12)C ratios, of reduced/organic carbon compounds have been widely utilized for deducing the origins and formation pathways of these compounds. An example is isotopic and C(sub 1)/(C(sub 2)+C(sub 3)) ratios of natural gases, which have been used to distinguish bacterial, thermogenic, and possible abiogenic origins. Another example is that ancient graphitic carbon with(delta)(sup 13)C values c-25per thousand has been considered of biogenic origin. Although these criteria could be largely valid, growing data including those from our hydrothermal experiments suggest that a great caution must be exercised

Charge-density matching in organic-inorganic uranyl compounds

International Nuclear Information System (INIS)

Krivovichev, S.V.; Krivovichev, S.V.; Tananaev, I.G.; Myasoedov, B.F.

2007-01-01

Single crystals of [C 10 H 26 N 2 ][(UO 2 )(SeO 4 ) 2 (H 2 O)](H 2 SeO 4 ) 0.85 (H 2 O) 2 (1), [C 10 H 26 N 2 ][(UO 2 )(SeO 4 ) 2 ] (H 2 SeO 4 ) 0.50 (H 2 O) (2), and [C 8 H 20 N] 2 [(UO 2 )(SeO 4 ) 2 (H 2 O)] (H 2 O) (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 UO 7 and SeO 4 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 [UO 2 (SeO 4 ) 2 (H 2 O)] 2- chains are separated by mixed organic-inorganic layers comprising from [NH 3 (CH 2 ) 10 NH 3 ] 2+ molecules, H 2 O molecules, and disordered electroneutral (H 2 SeO 4 ) groups. The structure of 2 has a similar architecture but a purely inorganic layer is represented by a fully connected [UO 2 (SeO 4 ) 2 ] 2- sheet. The structure of 3 does not contain disordered (H 2 SeO 4 ) groups but is based upon alternating [UO 2 (SeO 4 ) 2 (H 2 O)] 2- sheets and 1.5-nm-thick organic blocks consisting of positively charged protonated octylamine molecules, [NH 3 (CH 2 ) 7 CH 3 ] + . 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

Gas chromatographic determination of impurities of inorganic compounds

International Nuclear Information System (INIS)

Drugov, Yu.S.

1985-01-01

Methods of concentration, separation, detection in gas chromatographic determination of impurities of inorganic compounds including low-boiling gases, reactive gases, organometallic compounds, free metals, anions, etc. are reviewed. Methods of reaction gas chromatography for determining reactive gases, water, anions, metal chelates are considered in detail as well as methods of reaction-sorption concentration and reaction gas extraction. The application of gas chromatograpny ior anaiysis of water and atmosphere contamination, for determination of impurities in highly pure solid substances and gases is described

The exchange of inorganic carbon on the Canadian Beaufort Shelf

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Mol, Jacoba; Thomas, Helmuth; Hu, Xianmin; Myers, Paul G.

2017-04-01

The Mackenzie Shelf in the southeastern Beaufort Sea is an area that has experienced large changes in the past several decades as warming, sea-ice loss, and increased river discharge have altered carbon cycling. Upwelling and downwelling events are common on the shelf, caused by strong, fluctuating along-shore winds and resulting cross-shelf Ekman transport. Downwelling carries inorganic carbon and other remineralization products off the shelf and into the deep basin for possible long-term storage in the world oceans. Upwelling carries water high in dissolved inorganic carbon (DIC) and nutrients from the Pacific-origin upper halocline layer (UHL) onto the shelf. Profiles of DIC and total alkalinity (TA) taken in August and September of 2014 are used to investigate the cycling of inorganic carbon on the Mackenzie Shelf. The along-shore and cross-shelf transport of inorganic carbon is quantified using velocity field output from a simulation of the Arctic and Northern Hemisphere Atlantic (ANHA4) configuration of the Nucleus of European Modelling of the Ocean (NEMO) model. A strong upwelling event prior to sampling on the Mackenzie Shelf is analyzed and the resulting influence on the carbonate system, including the saturation state of aragonite and pH levels, is investigated. TA and δ18O are used to examine water mass distributions in the study area and analyze the influence of Pacific Water, Mackenzie River freshwater, and sea-ice melt on carbon dynamics and air-sea fluxes of CO2 in the surface mixed layer. Understanding carbon transfer in this seasonally dynamic environment is key in order to quantify the importance of Arctic shelf regions to the global carbon cycle and to provide a basis for understanding how its role will respond to the aforementioned changes in the regional marine system.

Organic-inorganic hybrid carbon dots for cell imaging

Science.gov (United States)

Liu, Huan; Zhang, Hongwen; Li, Jiayu; Tang, Yuying; Cao, Yu; Jiang, Yan

2018-04-01

In this paper, nitrogen-doped carbon dots (CDs) had been synthesized directly by one-step ultrasonic treatment under mild conditions. During the functionalization process, Octa-aminopropyl polyhedral oligomeric silsesquioxane hydrochloride salt (OA-POSS) was used as stabilizing and passivation agent, which lead to self-assembling of CDs in aqueous medium solution. OA-POSS was obtained via hydrolytic condensation of γ-aminopropyl triethoxy silane (APTES). The average size of CDs prepared was approximately 3.3 nm with distribution between 2.5 nm and 4.5 nm. The prepared organic-inorganic hybrid carbon dots have several characteristics such as photoluminescence emission wavelength, efficient cellular uptake, and good biocompatibility. The results indicate that OA-POSS can maintain the fluorescence properties of the carbon dots effectively, and reduced cytotoxicity provides the possibility for biomedical applications. More than 89% of the Hela cells were viable when incubated with 2 mg ml‑1 or lesser organic-inorganic hybrid carbon dots. Thus, it provides a potential for multicolor imaging with HeLa cells.

Simulating the effects of light intensity and carbonate system composition on particulate organic and inorganic carbon production in Emiliania huxleyi.

Science.gov (United States)

Holtz, Lena-Maria; Wolf-Gladrow, Dieter; Thoms, Silke

2015-05-07

Coccolithophores play an important role in the marine carbon cycle. Variations in light intensity and external carbonate system composition alter intracellular carbon fluxes and therewith the production rates of particulate organic and inorganic carbon. Aiming to find a mechanistic explanation for the interrelation between dissolved inorganic carbon fluxes and particulate carbon production rates, we develop a numerical cell model for Emiliania huxleyi, one of the most abundant coccolithophore species. The model consists of four cellular compartments, for each of which the carbonate system is resolved dynamically. The compartments are connected to each other and to the external medium via substrate fluxes across the compartment-confining membranes. By means of the model we are able to explain several pattern observed in particulate organic and inorganic carbon production rates for different strains and under different acclimation conditions. Particulate organic and inorganic carbon production rates for instance decrease at very low external CO2 concentrations. Our model suggests that this effect is caused mainly by reduced HCO3(-) uptake rates, not by CO2 limitation. The often observed decrease in particulate inorganic carbon production rates under Ocean Acidification is explained by a downregulation of cellular HCO3(-) uptake. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Photosynthesis and Calcification by Emiliania huxleyi (Prymnesiophyceae) as a Function of Inorganic Carbon Species

NARCIS (Netherlands)

Buitenhuis, Erik T.; Baar, Hein J.W. de; Veldhuis, Marcel J.W.

1999-01-01

To test the possibility of inorganic carbon limitation of the marine unicellular alga Emiliania huxleyi (Lohmann) Hay and Mohler, its carbon acquisition was measured as a function of the different chemical species of inorganic carbon present in the medium. Because these different species are

Inorganic chemistry of earliest sediments

International Nuclear Information System (INIS)

Ochiai, E.I.

1983-01-01

A number of inorganic elements are now known to be essential to organisms. Chemical evolutionary processes involving carbon, hydrogen, nitrogen and oxygen have been studied intensively and extensively, but the other essential elements have been rather neglected in the studies of chemical and biological evolution. This article attempts to assess the significance of inorganic chemistry in chemical and biological evolutionary processes on the earth. Emphasis is placed on the catalytic effects of inorganic elements and compounds, and also on possible studies on the earliest sediments, especially banded iron formation and stratabound copper from the inorganic point of view in the hope of shedding some light on the evolution of the environment and the biological effects on it. (orig./WL)

Effects of land use on soil inorganic carbon stocks in the Russian Chernozem.

Science.gov (United States)

Mikhailova, Elena A; Post, Christopher J

2006-01-01

Little is known about changes in soil inorganic carbon (SIC) stocks with depth and with land use in grassland ecosystems. This study was conducted to determine SIC stocks under different management regimes in the Mollisol, one of the typical soils in grasslands. Four sites were sampled: a native grassland field (not cultivated for at least 300 yr), an adjacent 50-yr continuous fallow field, a yearly cut hay field in the V.V. Alekhin Central-Chernozem Biosphere State Reserve in the Kursk region of Russia, and a continuously cropped field in the Experimental Station of the Kursk Institute of Agronomy and Soil Erosion Control. All sampled soils were classified as fine-silty, mixed, frigid Pachic Hapludolls. Significant differences occurred in SIC stocks between cultivated and grassland soil. The inorganic carbon stocks in the top 2 m were 107 Mg ha(-1) for the native grassland, 91 Mg ha(-1) for the yearly cut hay field, 242 Mg ha(-1) for the continuously cropped field, and 196 Mg ha(-1) for the 50-yr continuous fallow. The SIC was in the form of calcium carbonate and was mostly stored below the 1-m depth. The largest difference between inorganic carbon stocks was observed between the continuously cropped field and native grassland. The increase in inorganic carbon in the continuously cropped field and continuous fallow was attributed to initial cultivation and fertilization. Soil inorganic carbon in Mollisols is not accounted for in the current global carbon estimates.

Charge-density matching in organic-inorganic uranyl compounds

Energy Technology Data Exchange (ETDEWEB)

Krivovichev, S.V. [Saint Petersburg State Univ., Dept. of Crystallography, Faculty of Geology (Russian Federation); Krivovichev, S.V.; Tananaev, I.G.; Myasoedov, B.F. [Russian Academy of Sciences, A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Moscow (Russian Federation)

2007-10-15

Single crystals of [C{sub 10}H{sub 26}N{sub 2}][(UO{sub 2})(SeO{sub 4}){sub 2}(H{sub 2}O)](H{sub 2}SeO{sub 4}){sub 0.85}(H{sub 2}O){sub 2} (1), [C{sub 10}H{sub 26}N{sub 2}][(UO{sub 2})(SeO{sub 4}){sub 2}] (H{sub 2}SeO{sub 4}){sub 0.50}(H{sub 2}O) (2), and [C{sub 8}H{sub 20}N]{sub 2}[(UO{sub 2})(SeO{sub 4}){sub 2}(H{sub 2}O)] (H{sub 2}O) (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 UO{sub 7} and SeO{sub 4} 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 [UO{sub 2}(SeO{sub 4}){sub 2}(H{sub 2}O)]{sup 2-} chains are separated by mixed organic-inorganic layers comprising from [NH{sub 3}(CH{sub 2}){sub 10}NH{sub 3}]{sup 2+} molecules, H{sub 2}O molecules, and disordered electroneutral (H{sub 2}SeO{sub 4}) groups. The structure of 2 has a similar architecture but a purely inorganic layer is represented by a fully connected [UO{sub 2}(SeO{sub 4}){sub 2}]{sup 2-} sheet. The structure of 3 does not contain disordered (H{sub 2}SeO{sub 4}) groups but is based upon alternating [UO{sub 2}(SeO{sub 4}){sub 2}(H{sub 2}O)]{sup 2-} sheets and 1.5-nm-thick organic blocks consisting of positively charged protonated octylamine molecules, [NH{sub 3}(CH{sub 2}){sub 7}CH{sub 3}]{sup +}. 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

Kinetics of inorganic carbon utilization by microalgal biofilm in a flat plate photoreactor

Energy Technology Data Exchange (ETDEWEB)

Lin, Y.H.; Leu, J.Y.; Lan, C.R.; Lin, P.H.P.; Chang, F.L. [Development Center for Biotechnology, Taipei (Taiwan). Dept. for Environmental Program

2003-11-01

A kinetic model was developed to describe inorganic carbon utilization by microalgae biofilm in a flat plate photoreactor. The model incorporates the fundamental mechanisms of diffusive mass transport and biological reaction of inorganic carbon by microalgal biofilm. An advanced numerical technique, the orthogonal collocation method and Gear's method, was employed to solve this kinetic model. The model solutions included the concentration profiles of inorganic carbon in the microalgal biofilm, the growths of suspended microalgae and microalgal biofilm, the effluent concentrations of inorganic carbon, and the flux of inorganic carbon from bulk liquid into biofilm. The batch kinetic test was independently conducted to determine biokinetic parameters used in the microalgal biofilm model simulation while initial thickness of microalgal biofilm were assumed. A laboratory-scale flat plate photoreactor with a high recycle flow rate was set up and conducted to verify the model. The volume of photoreactor is 60 l which yields a hydraulic retention time of 1.67 days. The model-generated inorganic carbon and the suspended microalgae concentration curves agreed well with those obtained in the laboratory-scale test. The fixation efficiencies of HCO{sub 3}{sup -} and CO{sub 2} are 98.5% and 90% at a steady-state condition, respectively. The concentration of suspended microalgal cell reached up to 12 mg/l at a maximum growth rate while the thickness of microalgal biofilm was estimated to be 104 pm at a steady-state condition. The approaches of experiments and model simulation presented in this study could be employed for the design of a flat plate photoreactor to treat CO{sub 2} by microalgal biofilm in a fossil-fuel power plant.

Inorganic carbon availability in benthic diatom communities: photosynthesis and migration.

Science.gov (United States)

Marques da Silva, Jorge; Cruz, Sónia; Cartaxana, Paulo

2017-09-05

Diatom-dominated microphytobenthos (MPB) is the main primary producer of many intertidal and shallow subtidal environments, being therefore of critical importance to estuarine and coastal food webs. Owing to tidal cycles, intertidal MPB diatoms are subjected to environmental conditions far more variable than the ones experienced by pelagic diatoms (e.g. light, temperature, salinity, desiccation and nutrient availability). Nevertheless, benthic diatoms evolved adaptation mechanisms to these harsh conditions, including the capacity to move within steep physical and chemical gradients, allowing them to perform photosynthesis efficiently. In this contribution, we will review present knowledge on the effects of dissolved inorganic carbon (DIC) availability on photosynthesis and productivity of diatom-dominated MPB. We present evidence of carbon limitation of photosynthesis in benthic diatom mats and highly productive MPB natural communities. Furthermore, we hypothesize that active vertical migration of epipelic motile diatoms could overcome local depletion of DIC in the photic layer, providing the cells alternately with light and inorganic carbon supply. The few available longer-term experiments on the effects of inorganic carbon enrichment on the productivity of diatom-dominated MPB have yielded inconsistent results. Therefore, further studies are needed to properly assess the response of MPB communities to increased CO 2 and ocean acidification related to climate change.This article is part of the themed issue 'The peculiar carbon metabolism in diatoms'. © 2017 The Author(s).

Bonding in inorganic compounds: a study by x-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Avanzino, S.C.

1978-10-01

Core electron binding energies were measured for a variety of inorganic and organometallic compounds using gas-phase X-ray photoelectron spectroscopy (XPS). The atomic charge distributions in these molecules are deduced from the binding energies, often leading to a better understanding of the bonding in these compounds. The XPS spectra of fifteen volatile tin compounds were recorded. The data suggest that the metal d orbitals are not significantly involved in the bonding. The oxygen ls XPS spectra of gaseous CH 3 Mn(CO) 5 , [π-C 5 H 5 Fe(CO) 2 ] 2 , and Co 4 (CO) 12 can be readily resolved into separate peaks due to bridging and terminal carbonyl groups. The C ls spectrum of Fe(CO) 5 consists of a single symmetric peak. The carbonyl ligand core binding energies of transition-metal carbonyl complexes are sensitive to differences in the metal-to-CO ligand bonding. Both C ls and O ls carbonyl binding energies correlate well with average C-O stretching force constants or average C-O stretching frequencies. The metal and carbonyl binding energies in a series of pentacarbonylmanganese complexes LMn(CO) 5 are a good measure of the relative electronegativities of the ligands L. High-quality X-ray photoelectron spectra have been obtained for compounds dissolved in glycerin solutions, and aqueous solutions were converted into glycerin solutions which gave good XRSspectra of the solutes. The technique appears promising as a future analytical application of X-ray photoelectron spectroscopy. The shifts in the binding energies of oxygen, chlorine, and carbon atoms in some isoelectronic isostructural compounds can be explained in terms of simple trends in atomic charges

Fractionation between inorganic and organic carbon during the Lomagundi (2.22 2.1 Ga) carbon isotope excursion

Science.gov (United States)

Bekker, A.; Holmden, C.; Beukes, N. J.; Kenig, F.; Eglinton, B.; Patterson, W. P.

2008-07-01

The Lomagundi (2.22-2.1 Ga) positive carbon isotope excursion in shallow-marine sedimentary carbonates has been associated with the rise in atmospheric oxygen, but subsequent studies have demonstrated that the carbon isotope excursion was preceded by the rise in atmospheric oxygen. The amount of oxygen released to the exosphere during the Lomagundi excursion is constrained by the average global fractionation between inorganic and organic carbon, which is poorly characterized. Because dissolved inorganic and organic carbon reservoirs were arguably larger in the Paleoproterozoic ocean, at a time of lower solar luminosity and lower ocean redox state, decoupling between these two variables might be expected. We determined carbon isotope values of carbonate and organic matter in carbonates and shales of the Silverton Formation, South Africa and in the correlative Sengoma Argillite Formation, near the border in Botswana. These units were deposited between 2.22 and 2.06 Ga along the margin of the Kaapvaal Craton in an open-marine deltaic setting and experienced lower greenschist facies metamorphism. The prodelta to offshore marine shales are overlain by a subtidal carbonate sequence. Carbonates exhibit elevated 13C values ranging from 8.3 to 11.2‰ vs. VPDB consistent with deposition during the Lomagundi positive excursion. The total organic carbon (TOC) contents range from 0.01 to 0.6% and δ13C values range from - 24.8 to - 13.9‰. Thus, the isotopic fractionation between organic and carbonate carbon was on average 30.3 ± 2.8‰ ( n = 32) in the shallow-marine environment. The underlying Sengoma shales have highly variable TOC contents (0.14 to 21.94%) and δ13C values (- 33.7 to - 20.8‰) with an average of - 27.0 ± 3.0‰ ( n = 50). Considering that the shales were also deposited during the Lomagundi excursion, and taking δ13C values of the overlying carbonates as representative of the δ13C value of dissolved inorganic carbon during shale deposition, a carbon

[Responses of rice-wheat rotation system in south Jiangsu to organic-inorganic compound fertilizers].

Science.gov (United States)

Tian, Heng-Da; Zhang, Li; Zhang, Jian-Chao; Wang, Qiu-Jun; Xu, Da-Bing; Yibati, Halihashi; Xu, Jia-Le; Huang, Qi-Wei

2011-11-01

In 2006-2007, a field trial was conducted to study the effects of applying three kinds of organic-inorganic compound fertilizers [rapeseed cake compost plus inorganic fertilizers (RCC), pig manure compost plus inorganic fertilizers (PMC), and Chinese medicine residues plus inorganic fertilizers (CMC)] on the crop growth and nitrogen (N) use efficiency of rice-wheat rotation system in South Jiangsu. Grain yield of wheat and rice in the different fertilization treatments was significantly higher than the control (no fertilization). In treatments RCC, PMC and CMC, the wheat yield was 13.1%, 32.2% and 39.3% lower than that of the NPK compound fertilizer (CF, 6760 kg x hm(-2)), respectively, but the rice yield (8504-9449 kg x hm(-2)) was significantly higher than that (7919 kg x hm(-2)) of CF, with an increment of 7.4%-19.3%. In wheat season, the aboveground dry mass, N accumulation, and N use efficiency in treatments RCC, PMC, and CMC were lower than those of CF, but in rice season, these parameters were significantly higher than or as the same as CF. In sum, all the test three compound fertilizers had positive effects on the rice yield and its nitrogen use efficiency in the rice-wheat rotation system, being most significant for RCC.

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

International Nuclear Information System (INIS)

Ewan, T.L.

2004-01-01

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 (CO 2 ) 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

Dissolved organic carbon biodegradability from thawing permafrost stimulated by sunlight rather than inorganic nitrogen

Science.gov (United States)

Liu, F.; Chen, L.; Zhang, B.; Wang, G.; Qin, S.; Yang, Y.

2017-12-01

Permafrost thaw could result in a large portion of frozen carbon being laterally transferred to aquatic ecosystems as dissolved organic carbon (DOC). During this delivery process, the size of biodegradable DOC (BDOC) determines the proportion of DOC mineralized by microorganisms and associated carbon loss to the atmosphere, which may further trigger positive carbon-climate feedback. Thermokarst is an abrupt permafrost thaw process that can enhance DOC export and also impact DOC processing through increased inorganic nitrogen (N) and sunlight exposure. However, it remains unclear how thermokarst-impacted BDOC responds to inorganic N addition and ultraviolet (UV) light irradiation. Here we explored the responses of DOC concentration, composition and its biodegradability to inorganic N and UV light in a typical thermokarst on the Tibetan Plateau, by combining field observation and laboratory incubation with spectra analyses (UV-visible absorption and three-dimensional fluorescence spectra) and parallel factor analyses. Our results showed that BDOC in thermokarst feature outflows was significantly higher than in reference water. Furthermore, inorganic N addition had no influence on thermokarst-impacted BDOC, whereas exposure to UV light significantly increased BDOC by as much as 2.3 times higher than the dark-control. Moreover, N addition and UV irradiation did not generate additive effects on BDOC. These results imply that sunlight rather than inorganic N can increase thermokarst-derived BDOC, potentially strengthening the positive permafrost carbon-climate feedback.

Enrichment of Inorganic Martian Dust Simulant with Carbon Component can Provoke Neurotoxicity

Science.gov (United States)

Pozdnyakova, Natalia; Pastukhov, Artem; Dudarenko, Marina; Borysov, Arsenii; Krisanova, Natalia; Nazarova, Anastasia; Borisova, Tatiana

2017-02-01

Carbon is the most abundant dust-forming element in the interstellar medium. Tremendous amount of meteorites containing plentiful carbon and carbon-enriched dust particles have reached the Earth daily. National Institute of Health panel accumulates evidences that nano-sized air pollution components may have a significant impact on the central nervous system (CNS) in health and disease. During inhalation, nano-/microsized particles are efficiently deposited in nasal, tracheobronchial, and alveolar regions and can be transported to the CNS. Based on above facts, here we present the study, the aims of which were: 1) to upgrade inorganic Martian dust simulant derived from volcanic ash (JSC-1a/JSC, ORBITEC Orbital Technologies Corporation, Madison, Wisconsin) by the addition of carbon components, that is, nanodiamonds and carbon dots; 2) to analyse acute effects of upgraded simulant on key characteristics of synaptic neurotransmission; and 3) to compare above effects with those of inorganic dust and carbon components per se. Acute administration of carbon-containing Martian dust analogues resulted in a significant decrease in transporter-mediated uptake of L-[14C]glutamate (the major excitatory neurotransmitter) and [3H]GABA (the main inhibitory neurotransmitter) by isolated rat brain nerve terminals. The extracellular level of both neurotransmitters increased in the presence of carbon-containing Martian dust analogues. These effects were associated with action of carbon components of upgraded Martian dust simulant, but not with its inorganic constituent. This fact indicates that carbon component of native Martian dust can have deleterious effects on extracellular glutamate and GABA homeostasis in the CNS, and so glutamate- and GABA-ergic neurotransmission disballansing exitation and inhibition.

Urea route to coat inorganic nanowires, carbon fibers and nanotubes by boron nitride

International Nuclear Information System (INIS)

Gomathi, A.; Ramya Harika, M.; Rao, C.N.R.

2008-01-01

A simple route involving urea as the nitrogen source has been employed to carry out boron nitride coating on carbon fibers, multi-walled carbon nanotubes and inorganic nanowires. The process involves heating the carbon fibers and nanotubes or inorganic nanowires in a mixture of H 3 BO 3 and urea, followed by a heat treatment at 1000 deg. C in a N 2 atmosphere. We have been able to characterize the BN coating by transmission electron microscopy as well as X-ray photoelectron spectroscopy. The urea decomposition route affords a simple method to coat boron nitride on one-dimensional nanostructures

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...

Contribution of fish to the marine inorganic carbon cycle.

Science.gov (United States)

Wilson, R W; Millero, F J; Taylor, J R; Walsh, P J; Christensen, V; Jennings, S; Grosell, M

2009-01-16

Oceanic production of calcium carbonate is conventionally attributed to marine plankton (coccolithophores and foraminifera). Here we report that marine fish produce precipitated carbonates within their intestines and excrete these at high rates. When combined with estimates of global fish biomass, this suggests that marine fish contribute 3 to 15% of total oceanic carbonate production. Fish carbonates have a higher magnesium content and solubility than traditional sources, yielding faster dissolution with depth. This may explain up to a quarter of the increase in titratable alkalinity within 1000 meters of the ocean surface, a controversial phenomenon that has puzzled oceanographers for decades. We also predict that fish carbonate production may rise in response to future environmental changes in carbon dioxide, and thus become an increasingly important component of the inorganic carbon cycle.

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)

Bartholomay, R.C.; Edwards, D.D.; Campbell, L.J.

1994-01-01

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

Development of conjugate methods with gas chromatography for inorganic compounds analysis

International Nuclear Information System (INIS)

Baccan, N.

1975-01-01

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)

Determination of 14C age of inorganic and organic carbon in ancient Siberian permafrost

Science.gov (United States)

Onstott, T. C.; Liang, R.; Lau, M.; Vishnivetskaya, T. A.; Lloyd, K. G.; Pfiffner, S. M.; Hodgins, G.; Rivkina, E.

2017-12-01

Permafrost represents a large reservoir of ancient carbon that could have an important impact on the global carbon budget during climate warming. Due to the low turnover rate of carbon by microorganisms at subzero temperatures, the persistence of ancient carbon in younger permafrost deposits could also pose challenges for radiocarbon dating of permafrost sediment. We utilized Accelerator Mass Spectrometry to determine the 14C age of inorganic carbon, labile and recalcitrant organic carbon in Siberian permafrost sediment sampled at various depths from 2.9 to 5.6m. The fraction of inorganic carbon (CO2) was collected after acidification using phosphoric acid. The labile (younger) and recalcitrant (old) organic carbon in the subsequent residues were collected after combustion at 400 ºC and 800 ºC, respectively. The percentages of inorganic carbon increased from the youngest (2.9m) to the oldest (5.6m), whereas the fractions for organic carbon varied significantly at different depths. The 14C age determined in the inorganic fraction in the top sample (2.9 m) was 21,760 yr BP and gradually increased to 33,900 yr BP in the relative deeper sediment (3.5 and 5.6 m). Surprisingly, the fraction of "younger" carbon liberated at 400 oC was older than the more recalcitrant and presumably older organic carbon liberated at 800 oC in all cases. Moreover, the 14C age of the younger and older organic carbon fractions did not increase with depth as observed in the carbonate fraction. In particular, the 14C age of the organic carbon in the top sample (38,590-41,700 yr BP) was much older than the deeper samples at depth of 3.5m (18,228-20,158 yr BP) and 5.6m (29,040-38,020 yr BP). It should be noticed that the metabolism of ancient carbon in frozen permafrost may vary at different depths due to the different proportion of necromass and metabolically active microbes. Therefore, additional knowledge about the carbon dynamics of permafrost and more investigation would be required to

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

International Nuclear Information System (INIS)

Scapin, Marcos Antonio

2008-01-01

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)

Matrix- and tensor-based recommender systems for the discovery of currently unknown inorganic compounds

Science.gov (United States)

Seko, Atsuto; Hayashi, Hiroyuki; Kashima, Hisashi; Tanaka, Isao

2018-01-01

Chemically relevant compositions (CRCs) and atomic arrangements of inorganic compounds have been collected as inorganic crystal structure databases. Machine learning is a unique approach to search for currently unknown CRCs from vast candidates. Herein we propose matrix- and tensor-based recommender system approaches to predict currently unknown CRCs from database entries of CRCs. Firstly, the performance of the recommender system approaches to discover currently unknown CRCs is examined. A Tucker decomposition recommender system shows the best discovery rate of CRCs as the majority of the top 100 recommended ternary and quaternary compositions correspond to CRCs. Secondly, systematic density functional theory (DFT) calculations are performed to investigate the phase stability of the recommended compositions. The phase stability of the 27 compositions reveals that 23 currently unknown compounds are newly found to be stable. These results indicate that the recommender system has great potential to accelerate the discovery of new compounds.

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)

Bartholomay, R.C.; Williams, L.M.; Campbell, L.J.

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

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...... 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 mu mol Cm-2 s(-1), respectively...

U6+ minerals and inorganic compounds: insights into an expanded structural hierarchy of crystal structures

International Nuclear Information System (INIS)

Burns, P.C.

2005-01-01

The crystal structures of uranyl minerals and inorganic uranyl compounds are important for understanding the genesis of U deposits, the interaction of U mine and mill tailings with the environment, transport of actinides in soils and the vadose zone, the performance of geological repositories for nuclear waste, and for the development of advanced materials with novel applications. Over the past decade, the number of inorganic uranyl compounds (including minerals) with known structures has more than doubled, and reconsideration of the structural hierarchy of uranyl compounds is warranted. Here, 368 inorganic crystal structures that contain essential U 6+ are considered (of which 89 are minerals). They are arranged on the basis of the topological details of their structural units, which are formed by the polymerization of polyhedra containing higher-valence cations. Overarching structural categories correspond to those based upon isolated polyhedra (8), finite clusters (43), chains (57), sheets (204), and frameworks (56) of polyhedra. Within these categories, structures are organized and compared upon the basis of either their graphical representations, or in the case of sheets involving sharing of edges of polyhedra, upon the topological arrangement of anions within the sheets. (author)

Safe recycling of materials containing persistent inorganic and carbon nanoparticles

NARCIS (Netherlands)

Reijnders, L.; Njuguna, J.; Pielichowski, K.; Zhu, H.

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

Distribution of Coral Reef and Seagrass Ecosystems’s Inorganic Carbon in the Waters of Beras Basah Bontang, East Kalimantan

Directory of Open Access Journals (Sweden)

Irwan Ramadhan Ritonga

2013-06-01

Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Inorganic carbon is closely related to the calcification process (CaCO3, which is the main constituent of coral reefs or microorganisms that exist in the oceans such as foraminifera and cocolitoporit. Inorganic carbon is also closely linked to the chemical processes that occur when carbon dioxide gas (CO2 dissolved in water. The research of inorganic carbon in the waters of Beras Basah was carried out in January, February and March 2012. The purpose of this study was to understand the distribution and concentration of total inorganic carbon (CT in coral reef and seagrass ecosystems as well as the correlation of Beras Basah. The results showed that the concentration of total inorganic carbon (CT in January average 1166.503 μmol/kgSW, February average 1115.599 μmol/kgSW, and then in March the average 987.443 μmol/kgSW. Distribution patterns of total inorganic carbon (CT is vectoral, where in January, the concentration of total inorganic carbon (CT was highest in the Southeast region, was in February in the South and Southeast, while in March shifted to North region of Beras Basah Island. The concentration difference is thought to be influenced by pH and the seasons, tides, biochemical processes, and biological activity. Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Doi: 10.12777/ijse.5.1.1-5 [How to cite this article: Ritonga, I.R., Supriharyono, and Henderarto, B. (2013. Distribution of Coral Reef and Seagrass Ecosystems’s Inorganic Carbon in the Waters of Beras Basah Bontang, East Kalimantan. International Journal of Science and Engineering, 5(1,1-6. Doi: 10.12777/ijse.5.1.1-5]  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...

Spectral determination of individual rare earths in different classes of inorganic compounds

International Nuclear Information System (INIS)

Karpenko, L.I.; Fadeeva, L.A.; Shevchenko, L.D.

1979-01-01

The conditions are found allowing to analyze various inorganic compounds for rare-earth elements without separation from non-rare-earth components. The influence of the plasma composition on the intensity of spectral lines of rare-earth elements is studied. The relative intensity of homologous spectral lines of various rare-earth elements remains constant regardless of the plasma composition. The conditions are found for the determination of individual rare-earth elements acting as both alloying additives (Csub(n) -- n x 10 -1 -n x 10 -3 %), and basic components (up to tens of per cent) in different classes of inorganic compounds of 1-7 elements. The general method is developed for the determination of individual rare-earth elements in mixtures of oxides of rare-earth elements, complex fluorides of rare-earth elements and elements of group 2, gallates, borates, germanates, vanadates of rare-earth elements and aluminium; zirconates-titanates of lead and barium, containing modifying additives of rare-earth elements, complex chalcogenides of rare-earth elements and elements of group 5

Inorganic carbon uptake during photosynthesis. II. Uptake by isolated Asparagus mesophyll cells during isotopic disequilibrium

International Nuclear Information System (INIS)

Espie, G.S.; Owttrim, G.W.; Colman, B.

1986-01-01

The species of inorganic carbon (CO 2 or HCO 3 - ) taken up as a source of substrate for photosynthetic fixation by isolated Asparagus sprengeri mesophyll cells is investigated. Discrimination between CO 2 or HCO 3 - transport, during steady state photosynthesis, is achieved by monitoring the changes (by 14 C fixation) which occur in the specific activity of the intracellular pool of inorganic carbon when the inorganic carbon present in the suspending medium is in a state of isotopic disequilibrium. Quantitative comparisons between theoretical (CO 2 or HCO 3 - transport) and experimental time-courses of 14 C incorporation, over the pH range of 5.2 to 7.5, indicate that the specific activity of extracellular CO 2 , rather than HCO 3 - , is the appropriate predictor of the intracellular specific activity. It is concluded, therefore, that CO 2 is the major source of exogenous inorganic carbon taken up by Asparagus cells. However, at high pH (8.5), a component of net DIC uptake may be attributable to HCO 3 - transport, as the incorporation of 14 C during isotopic disequilibrium exceeds the maximum possible incorporation predicted on the basis of CO 2 uptake alone. The contribution of HCO 3 - to net inorganic carbon uptake (pH 8.5) is variable, ranging from 5 to 16%, but is independent of the extracellular HCO 3 - concentration. The evidence for direct HCO 3 - transport is subject to alternative explanations and must, therefore, be regarded as equivocal. Nonlinear regression analysis of the rate of 14 C incorporation as a function of time indicates the presence of a small extracellular resistance to the diffusion of CO 2 , which is partially alleviated by a high extracellular concentration of HCO 3 -

Involvement of H(+)-ATPase and carbonic anhydrase in inorganic carbon uptake for endosymbiont photosynthesis.

Science.gov (United States)

Furla, P; Allemand, D; Orsenigo, M N

2000-04-01

Symbiotic cnidarians absorb inorganic carbon from seawater to supply intracellular dinoflagellates with CO(2) for their photosynthesis. To determine the mechanism of inorganic carbon transport by animal cells, we used plasma membrane vesicles prepared from ectodermal cells isolated from tentacles of the sea anemone, Anemonia viridis. H(14)CO(-)(3) uptake in the presence of an outward NaCl gradient or inward H(+) gradient, showed no evidence for a Cl(-)- or H(+)- driven HCO(-)(3) transport. H(14)CO(-)(3) and (36)Cl(-) uptakes were stimulated by a positive inside-membrane diffusion potential, suggesting the presence of HCO(-)(3) and Cl(-) conductances. A carbonic anhydrase (CA) activity was measured on plasma membrane (4%) and in the cytoplasm of the ectodermal cells (96%) and was sensitive to acetazolamide (IC(50) = 20 nM) and ethoxyzolamide (IC(50) = 2.5 nM). A strong DIDS-sensitive H(+)-ATPase activity was observed (IC(50) = 14 microM). This activity was also highly sensitive to vanadate and allyl isothiocyanate, two inhibitors of P-type H(+)-ATPases. Present data suggest that HCO(-)(3) absorption by ectodermal cells is carried out by H(+) secretion by H(+)-ATPase, resulting in the formation of carbonic acid in the surrounding seawater, which is quickly dehydrated into CO(2) by a membrane-bound CA. CO(2) then diffuses passively into the cell where it is hydrated in HCO(-)(3) by a cytosolic CA.

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.

Use of carbonates for biological and chemical synthesis

Science.gov (United States)

Rau, Gregory Hudson

2014-09-09

A system of using carbonates, especially water-insoluble or sparing soluble mineral carbonates, for maintaining or increasing dissolved inorganic carbon concentrations in aqueous media. In particular, the system generates concentrated dissolve inorganic carbon substrates for photosynthetic, chemosynthetic, or abiotic chemical production of carbonaceous or other compounds in solution. In some embodiments, the invention can also enhance the dissolution and retention of carbon dioxide in aqueous media, and can produce pH buffering capacity, metal ions, and heat, which can be beneficial to the preceding syntheses.

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

. 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......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...... activities of carbonic anhydrase (CA), photosynthetic O-2 evolution and CO2 and HCO3- uptake rates were measured by membrane inlet MS in cells acclimated to low (7.9) and high pH (8.4 or 8.9). Species-specific differences in the mode of carbon acquisition were found. While extracellular carbonic anhydrase (e...

Inorganic carbon addition stimulates snow algae primary productivity

Science.gov (United States)

Hamilton, T. L.; Havig, J. R.

2017-12-01

Earth has experienced glacial/interglacial oscillations throughout its history. Today over 15 million square kilometers (5.8 million square miles) of Earth's land surface is covered in ice including glaciers, ice caps, and the ice sheets of Greenland and Antarctica, most of which are retreating as a consequence of increased atmospheric CO2. Glaciers are teeming with life and supraglacial snow and ice surfaces are often red due to blooms of photoautotrophic algae. Recent evidence suggests the red pigmentation, secondary carotenoids produced in part to thrive under high irradiation, lowers albedo and accelerates melt. However, there are relatively few studies that report the productivity of snow algae communities and the parameters that constrain their growth on snow and ice surfaces. Here, we demonstrate that snow algae primary productivity can be stimulated by the addition of inorganic carbon. We found an increase in light-dependent carbon assimilation in snow algae microcosms amended with increasing amounts of inorganic carbon. Our snow algae communities were dominated by typical cosmopolitan snow algae species recovered from Alpine and Arctic environments. The climate feedbacks necessary to enter and exit glacial/interglacial oscillations are poorly understood. Evidence and models agree that global Snowball events are accompanied by changes in atmospheric CO2 with increasing CO2 necessary for entering periods of interglacial time. Our results demonstrate a positive feedback between increased CO2 and snow algal productivity and presumably growth. With the recent call for bio-albedo effects to be considered in climate models, our results underscore the need for robust climate models to include feedbacks between supraglacial primary productivity, albedo, and atmospheric CO2.

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

Science.gov (United States)

Bartholomay, Roy C.; Edwards, Daniel D.; Campbell, Linford J.

1994-01-01

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 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 radionuclides, inorganic constituents, or organic compounds exceeded the established maximum contaminant levels for drinking water. Most of the radionuclide and inorganic constituent concen- trations exceeded their respective laboratory reporting levels. All samples analyzed for surfactants and dissolved organic carbon had concentrations that exceeded their reporting level. Ethylbenzene concentrations exceeded the reporting level in one water sample.

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

Energy Technology Data Exchange (ETDEWEB)

Liu, Yunde [State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074 (China); School of Environmental Studies, China University of Geosciences, Wuhan 430074 (China); Laboratory of Basin Hydrology and Wetland Eco-restoration, China University of Geosciences, Wuhan 430074 (China); Zhou, Aiguo, E-mail: aiguozhou@cug.edu.cn [State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074 (China); School of Environmental Studies, China University of Geosciences, Wuhan 430074 (China); Gan, Yiqun; Li, Xiaoqian [State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074 (China); School of Environmental Studies, China University of Geosciences, Wuhan 430074 (China)

2016-05-05

Highlights: • The effect of inorganic anions on carbon isotope fractionation was evaluated. • The enrichment factors was independent concentration of NO{sub 3}{sup −}, or SO{sub 4}{sup 2−}. • Cl{sup −} significantly influenced the carbon isotope fractionation. - Abstract: 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.

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

International Nuclear Information System (INIS)

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

2016-01-01

Highlights: • The effect of inorganic anions on carbon isotope fractionation was evaluated. • The enrichment factors was independent concentration of NO_3"−, or SO_4"2"−. • Cl"− significantly influenced the carbon isotope fractionation. - Abstract: 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.

Photochemical mineralization of terrigenous DOC to dissolved inorganic carbon in ocean

OpenAIRE

Aarnos, Hanna; Gélinas, Yves; Kasurinen, Ville; Gu, Yufei; Puupponen, Veli-Mikko; Vähätalo, Anssi

2018-01-01

When terrigenous dissolved organic carbon (tDOC) rich in chromophoric dissolved organic matter (tCDOM) enters the ocean, solar radiation mineralizes it partially into dissolved inorganic carbon (DIC). This study addresses the amount and the rates of DIC photoproduction from tDOC and the area of ocean required to photomineralize tDOC. We collected water samples from 10 major rivers, mixed them with artificial seawater, and irradiated them with simulated solar radiation to measure DIC photoprod...

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...

Scintillating Organic–Inorganic Layered Perovskite-type Compounds and the Gamma-ray Detection Capabilities

OpenAIRE

Kawano, Naoki; Koshimizu, Masanori; Okada, Go; Fujimoto, Yutaka; Kawaguchi, Noriaki; Yanagida, Takayuki; Asai, Keisuke

2017-01-01

We investigated scintillation properties of organic–inorganic layered perovskite-type compounds under gamma-ray and X-ray irradiation. A crystal of the hybrid compounds with phenethyl amine (17 × 23 × 4 mm) was successfully fabricated by the poor-solvent diffusion method. The bulk sample showed superior scintillation properties with notably high light yield (14,000 photons per MeV) under gamma-rays and very fast decay time (11 ns). The light yield was about 1.4 time higher than that of common...

Synthesis of PbI(2) single-layered inorganic nanotubes encapsulated within carbon nanotubes.

Science.gov (United States)

Cabana, Laura; Ballesteros, Belén; Batista, Eudar; Magén, César; Arenal, Raúl; Oró-Solé, Judith; Rurali, Riccardo; Tobias, Gerard

2014-04-02

The template assisted growth of single-layered inorganic nanotubes is reported. Single-crystalline lead iodide single-layered nanotubes have been prepared using the inner cavities of carbon nanotubes as hosting templates. The diameter of the resulting inorganic nanotubes is merely dependent on the diameter of the host. This facile method is highly versatile opening up new horizons in the preparation of single-layered nanostructures. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

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.

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

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)

Bartholomay, R.C.; Edwards, D.D.; Campbell, L.J.

1992-03-01

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

Hygroscopic growth and critical supersaturations for mixed aerosol particles of inorganic and organic compounds of atmospheric relevance

Directory of Open Access Journals (Sweden)

B. Svenningsson

2006-01-01

Full Text Available The organic fraction of atmospheric aerosols contains a multitude of compounds and usually only a small fraction can be identified and quantified. However, a limited number of representative organic compounds can be used to describe the water-soluble organic fraction. In this work, initiated within the EU 5FP project SMOCC, four mixtures containing various amounts of inorganic salts (ammonium sulfate, ammonium nitrate, and sodium chloride and three model organic compounds (levoglucosan, succinic acid and fulvic acid were studied. The interaction between water vapor and aerosol particles was studied at different relative humidities: at subsaturation using a hygroscopic tandem differential mobility analyzer (H-TDMA and at supersaturation using a cloud condensation nuclei spectrometer (CCN spectrometer. Surface tensions as a function of carbon concentrations were measured using a bubble tensiometer. Parameterizations of water activity as a function of molality, based on hygroscopic growth, are given for the pure organic compounds and for the mixtures, indicating van't Hoff factors around 1 for the organics. The Zdanovskii-Stokes-Robinson (ZSR mixing rule was tested on the hygroscopic growth of the mixtures and it was found to adequately explain the hygroscopic growth for 3 out of 4 mixtures, when the limited solubility of succinic acid is taken into account. One mixture containing sodium chloride was studied and showed a pronounced deviation from the ZSR mixing rule. Critical supersaturations calculated using the parameterizations of water activity and the measured surface tensions were compared with those determined experimentally.

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.

Information profiles on potential occupational hazards: Inorganic chromium compounds. Draft report (Second)

Energy Technology Data Exchange (ETDEWEB)

1982-02-01

Information profiles are presented for the following inorganic chromium compounds: chromic(VI) acid, chromic(III) hydroxide, chromic(III) oxide, chromic(III) sulfate, chromic(III) sulfate (basic), chromium dioxide, potassium dichromate(VI), lead chromate, sodium-chromate(VI), sodium-dichromate(VI), and zinc-yellow-chromate(VI). Biological effects of hexavalent chromium in humans included skin ulceration, dermatitis, nasal membrane irritation and ulceration, nasal septal perforation, rhinitis, nosebleed, nephritis, liver damage, epigastric pain, pulmonary congestion and edema, and erosion and discoloration of teeth. Chromium(VI) compounds caused mutations in a variety of systems. Exposure to trivalent chromium in the work place has caused contact dermatitis and chrome ulcers. Epidemiological studies indicated respiratory carcinogenicity among workers occupationally exposed during chromate production.

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

International Nuclear Information System (INIS)

Fodorne Csanyi, P.

1982-01-01

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.)

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.[...

Inorganic carbon turnover caused by digestion of carbonate sands and metabolic activity of holothurians

Science.gov (United States)

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

2013-11-01

Recent measurements have shown that holothurians (sea cucumbers) may play an important role in the cycling of CaCO3 in tropical coral reef systems through ingestion and processing of carbonate sediment. In this report, we present estimates of inorganic carbon turnover rates determined from laboratory incubations of Holothuria atra, Holothuria leucospilota and Stichopus herrmanni. The pH values of the gut lumen ranged from 7.0 to 7.6 when digestive tracts were filled with sediment compared with 6.1-6.7 in animals with empty digestive tracts. Empty gut volume estimates for H. atra and S. herrmanni were 36 ± 4 mL and 151 ± 14 mL, respectively. Based on these measurements and the density and porosity of carbonate sediments of coral reefs, it is estimated that these species process 19 ± 2 kg and 80 ± 7 kg CaCO3 sand yr-1 per individual, respectively. The annual CaCO3 dissolution rates per H. atra and S. herrmanni individual are estimated to be 6.5 ± 1.9 g and 9.6 ± 1.4 g, respectively, suggesting that 0.05 ± 0.02% and 0.1 ± 0.02% of the CaCO3 processed through their gut annually is dissolved. During incubations the CaCO3 dissolution of the fecal casts was 0.07 ± 0.01%, 0.04 ± 0.01% and 0.21 ± 0.05% for H. atra, H. leucospilota and S. herrmanni, respectively. The CaCO3 saturation state in the incubation seawater 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.

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

Input of particulate organic and dissolved inorganic carbon from the Amazon to the Atlantic Ocean

OpenAIRE

Druffel, E. R. M; Bauer, J. E; Griffin, S.

2005-01-01

We report concentrations and isotope measurements (radiocarbon and stable carbon) of dissolved inorganic carbon (DIC) and suspended particulate organic carbon (POC) in waters collected from the mouth of the Amazon River and the North Brazil Current. Samples were collected in November 1991, when the Amazon hydrograph was at its annual minimum and the North Brazil Current had retroflected into the equatorial North Atlantic. The DIC Δ14C results revealed postbomb carbon in river and ocean waters...

Inorganic liquid scintillator

International Nuclear Information System (INIS)

Pavlicek, Z.; Barta, C.; Jursova, L.

1986-01-01

An inorganic liquid scintillator is designed which contains 1 to 30 wt.% of an inorganic molecular compound as the basic active component; the compound contains a cation with an atomic number higher than 47 and a halogen anion. The basic inorganic component is dissolved in water or in an organic solvent in form of non-dissociated molecules or self-complexes in which the bond is preserved between the cation and anion components. The light yield from these scintillators ranges between 70 and 150% of the light yield of a standard organic scintillator based on toluene. They are advantageous in that that they allow to increase the water content in the sample to up to 100%. (M.D.)

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.

Neutron diffraction by monocrystals of inorganic and elementary organic compounds

International Nuclear Information System (INIS)

Becker, G.; Hauser, H.D.

1992-01-01

The phase of preparation and X-ray structural analysis of the compounds has been completed following the synthetical preparation of compounds sensitive to oxidation and pyrolysis, in this case: phosphonic acid, potassium silanide, lithium dihydrogenphosphide * DME, bis[lithium-tri(tert.butyl)alanate], dibromophenylbismuthate, potassium tetrahydride aluminate, and phosphinic acid. The work was started is neutron diffraction experiments for detecting the positions of the hydrogen and carbon atoms, in order to analyse space group problems. (BBR) [de

Simulated In Situ Determination of Soil Profile Organic and Inorganic Carbon With LIBS and VisNIR

Science.gov (United States)

Bricklemyer, R. S.; Brown, D. J.; Clegg, S. M.; Barefield, J. E.

2008-12-01

There is growing need for rapid, accurate, and inexpensive methods to measure, and verify soil organic carbon (SOC) change for national greenhouse gas accounting and the development of a soil carbon trading market. Laser Induced Breakdown Spectroscopy (LIBS) and Visible and Near Infrared Spectroscopy (VisNIR) are complementary analytical techniques that have the potential to fill that need. The LIBS method provides precise elemental analysis of soils, but generally cannot distinguish between organic C and inorganic C. VisNIR has been established as a viable technique for measuring soil properties including SOC and inorganic carbon (IC). As part of the Big Sky Carbon Sequestration Regional Partnership, 240 intact core samples (3.8 x 50 cm) have been collected from six agricultural fields in north central Montana, USA. Each of these core samples were probed concurrently with LIBS and VisNIR at 2.5, 7.5, 12.5, 17.5, 22.5, 27.5, 35 and 45 cm (+/- 1.5 cm) depths. VisNIR measurements were taken using an Analytical Spectral Devices (ASD, Boulder, CO, USA) Agrispec spectrometer to determine the partition of SOC vs. IC in the samples. The LIBS scans were collected with the LANL LIBS Core Scanner Instrument which collected the entire 200 - 900 nm plasma emission including the 247.8 nm carbon emission line. This instrument also collected the emission from the elements typically found in inorganic carbon (Ca and Mg) and organic carbon (H, O, and N). Subsamples of soil (~ 4 g) were taken from interrogation points for laboratory determination of SOC and IC. Using this analytical data, we constructed several full spectrum multivariate VisNIR/LIBS calibration models for SOC and IC. These models were then applied to independent validation cores for model evaluation.

Influence of Inorganic Ions and Organic Substances on the Degradation of Pharmaceutical Compound in Water Matrix

Directory of Open Access Journals (Sweden)

Edyta Kudlek

2016-11-01

Full Text Available The paper determined the influence of inorganic substances and high-molecular organic compounds on the decomposition of diclofenac, ibuprofen, and carbamazepine in the process of photocatalysis conducted with the presence of Titanium dioxide (TiO2. It was determined that the presence of such ions as CO 3 2 − , HCO 3 − , HPO 4 2 − as well as SO 4 2 − inhibited the decomposition of carbamazepine, whereas the efficiency of diclofenac degradation was decreased only by the presence of CO 3 2 − and HCO 3 − anions. In case of ibuprofen sodium salt (IBU, all investigated anions influenced the increase in its decomposition rate. The process of pharmaceutical photooxidation conducted in suspensions with Al3+ and Fe3+ cations was characterized by a significantly decreased efficiency when compared to the solution deprived of inorganic compounds. The addition of Ca2+, Mg2+ and NH4+ affected the increase of reaction rate constant value of diclofenac and ibuprofen decomposition. On the other hand, high molecular organic compounds present in the model effluent additionally catalysed the degradation process of pharmaceutical compounds and constituted an additional sorbent that enabled to decrease their concentration. Toxicological analysis conducted in deionized water with pharmaceutical compounds’ patterns proved the production of by-products from oxidation and/or reduction of micropollutants, which was not observed for model effluent irradiation.

An overview of the bioremediation of inorganic contaminants

International Nuclear Information System (INIS)

Bolton, H. Jr.; Gorby, Y.A.

1995-01-01

Bioremediation, or the biological treatment of wastes, usually is associated with the remediation of organic contaminants. Similarly, there is an increasing body of literature and expertise in applying biological systems to assist in the bioremediation of soils, sediments, and water contaminated with inorganic compounds including metals, radionuclides, nitrates, and cyanides. Inorganic compounds can be toxic both to humans and to organisms used to remediate these contaminants. However, in contrast to organic contaminants, most inorganic contaminants cannot be degraded, but must be remediated by altering their transport properties. Immobilization, mobilization, or transformation of inorganic contaminants via bioaccumulation, biosorption, oxidation, reduction, methylation, demethylation, metal-organic complexation, ligand degradation, and phytoremediation are the various processes applied in the bioremediation of inorganic compounds. This paper briefly describes these processes, referring to other contributors in this book as examples when possible, and summarize the factors that must be considered when choosing bioremediation as a cleanup technology for inorganics. Understanding the current state of knowledge as well as the limitations for bioremediation of inorganic compounds will assist in identifying and implementing successful remediation strategies at sites containing inorganic contaminants. 79 refs

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.

Methodologies for extraction of dissolved inorganic carbon for stable carbon isotope studies : evaluation and alternatives

Science.gov (United States)

Hassan, Afifa Afifi

1982-01-01

The gas evolution and the strontium carbonate precipitation techniques to extract dissolved inorganic carbon (DIC) for stable carbon isotope analysis were investigated. Theoretical considerations, involving thermodynamic calculations and computer simulation pointed out several possible sources of error in delta carbon-13 measurements of the DIC and demonstrated the need for experimental evaluation of the magnitude of the error. An alternative analytical technique, equilibration with out-gassed vapor phase, is proposed. The experimental studies revealed that delta carbon-13 of the DIC extracted from a 0.01 molar NaHC03 solution by both techniques agreed within 0.1 per mil with the delta carbon-13 of the DIC extracted by the precipitation technique, and an increase of only 0.27 per mil in that extracted by the gas evolution technique. The efficiency of extraction of DIC decreased with sulfate concentration in the precipitation technique but was independent of sulfate concentration in the gas evolution technique. Both the precipitation and gas evolution technique were found to be satisfactory for extraction of DIC from different kinds of natural water for stable carbon isotope analysis, provided appropriate precautions are observed in handling the samples. For example, it was found that diffusion of atmospheric carbon dioxide does alter the delta carbon-13 of the samples contained in polyethylene bottles; filtration and drying in the air change the delta carbon-13 of the samples contained in polyethylene bottles; filtration and drying in the air change the delta carbon-13 of the precipitation technique; hot manganese dioxide purification changes the delta carbon-13 of carbon dioxide. (USGS)

Novel Hydrogen Compounds from a Potassium Carbonate Electrolytic Cell

International Nuclear Information System (INIS)

Mills, Randell L.

2000-01-01

Novel compounds containing hydrogen in new hydride and polymeric states that demonstrate novel hydrogen chemistry have been isolated following the electrolysis of a K 2 CO 3 electrolyte with the production of excess energy. Inorganic hydride clusters K[KH KHCO 3 ] n + and hydrogen polymer ions such as OH 23 + and H 16 - were identified by time-of-flight secondary ion mass spectroscopy. The presence of compounds containing new states of hydrogen was confirmed by X-ray photoelectron spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, and proton nuclear magnetic resonance spectroscopy

Studies on sorption of plutonium on inorganic exchangers from sodium carbonate medium

Energy Technology Data Exchange (ETDEWEB)

Pius, I C; Charyulu, M M; Sivaramakrishnan, C K [Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai (India); Venkataramani, B [Chemistry Division, Bhabha Atomic Research Centre, Mumbai (India)

1994-06-01

Sorption of Pu(IV) from sodium carbonate medium has been investigated by using different inorganic exchangers alumina, silica gel and hydrous titanium oxide. Distribution ratios of Pu(IV) for its sorption on these exchangers from sodium carbonate medium were found to be sufficiently high indicating the suitability of these exchangers for the removal of Pu(IV). The presence of uranium and dibutyl phosphate do not have any effect on distribution ratio. The 10% Pu(IV) breakthrough capacities for above exchangers have been determined with 5 ml bed at a flow rate of 30 ml/hour. (author). 4 refs., 2 tabs.

Salicylate-spectrophotometric determination of inorganic monochloramine

International Nuclear Information System (INIS)

Tao Hui; Chen Zhonglin; Li Xing; Yang Yanling; Li Guibai

2008-01-01

On the basis of classical Berthelot reaction, a simple salicylate-spectrophotometric method was developed for quantitative determination of inorganic monochloramine in water samples. With the catalysis of disodium pentacyanonitrosylferrate(III), inorganic monochloramine reacts with salicylate in equimolar to produce indophenol compound which has an intense absorption at 703 nm. Parameters that influence method performance, such as pH, dosage of salicylate and nitroprussiate and reaction time, were modified to enhance the method performance. By using this method, inorganic monochloramine can be distinguished from organic chloramines and other inorganic chlorine species, such as free chlorine, dichloramine, and trichloramine. The molar absorptivities of the final products formed by these compounds are below ±3% of inorganic monochloramine, because of the α-N in them have only one exchangeable hydrogen atom, and cannot react with salicylate to produce the indophenol compound. The upper concentrations of typical ions that do not interfere with the inorganic monochloramine determination are also tested to be much higher than that mostly encountered in actual water treatment. Case study demonstrates that the results obtained from this method are lower than DPD-titrimetric method because the organic chloramines formed by chlorination of organic nitrogenous compounds give no response in the newly established method. And the result measured by salicylate-spectrophotometric method is coincident with theoretical calculation

Elemental and stable isotopic approaches for studying the organic and inorganic carbon components in natural samples

International Nuclear Information System (INIS)

Helie, J-F

2009-01-01

The carbon cycle is an important part of major biogeochemical cycles. Many techniques may be used to characterize carbon amounts and sources in the environment. Here we first review the most popular techniques for the determination of organic and inorganic carbon concentrations. Decarbonatation techniques are also reviewed in details since it is often an important part of organic carbon analysis. The second part of this paper addresses the use of carbon stable isotopes to characterize organic carbon sources and processes in the environment. An overview of general stable isotopes background and terminology is given as well as the most popular analytical techniques.

Carbon Balance in an Irrigated Corn Field after Inorganic Fertilizer or Manure Application

Science.gov (United States)

Lentz, R. D.; Lehrsch, G. A.

2014-12-01

Little is known about inorganic fertilizer or manure effects on organic carbon (OC) and inorganic C (IC) losses from a furrow irrigated field, particularly in the context of other system C gains or losses. In 2003 and 2004, we measured dissolved organic and inorganic C (DOC, DIC), particulate OC and IC (POC, PIC) concentrations in irrigation inflow, runoff, and percolation waters (6-7 irrigations/y); C inputs from soil amendments and crop biomass; harvested C; and gaseous C emissions from field plots cropped to silage corn (Zea mays L.) in southern Idaho. Annual treatments included: (M) 13 (y 1) and 34 Mg/ha (y 2) stockpiled dairy manure; (F) 78 (yr 1) and 195 kg N/ha (y 2) inorganic N fertilizer; or (NA) no amendment--control. The mean annual total C input into M plots averaged 16.1 Mg/ha, 1.4-times greater than that for NA (11.5 Mg/ha) or F (11.1 Mg/ha), while total C outputs for the three treatments were similar, averaging 11.8 Mg/ha. Thus, the manure plots ended each growing season with an average net gain of 3.8 Mg C/ha (a positive net C flux), while the control (-0.5 Mg C/ha) and fertilizer (-0.4 Mg C/ha) treatments finished the season with a net C loss. Atmospheric CO2 incorporated into the crop biomass contributed 96% of the mean annual C input to NA and F plots but only 68% to M plots. We conclude that nutrient amendments substantially influence the short-term carbon balance of our furrow-irrigated system. Amendments had both direct and indirect influences on individual C components, such as the losses of DIC and POC in runoff and DOC in percolation water, producing temporally complex outcomes which may depend on environmental conditions external to the field.

Watershed scale spatial variability in dissolved and total organic and inorganic carbon in contrasting UK catchments

Science.gov (United States)

Cumberland, S.; Baker, A.; Hudson, N. J.

2006-12-01

Approximately 800 organic and inorganic carbon analyses have been undertaken from watershed scale and regional scale spatial surveys in various British catchments. These include (1) a small (urban catchment (Ouseburn, N England); (2) a headwater, lowland agricultural catchment (River Tern, C England) (3) a large UK catchment (River Tyne, ~3000 sq-km) and (4) a spatial survey of ~300 analyses from rivers from SW England (~1700 sq-km). Results demonstrate that: (1) the majority of organic and inorganic carbon is in the dissolved (DOC and DIC) fractions; (2) that with the exception of peat rich headwaters, DIC concentration is always greater than DOC; (3) In the rural River Tern, riverine DOC and DIC are shown to follow a simple end- member mixing between DIC (DOC) rich (poor) ground waters and DOC (DIC) rich (poor) riparian wetlands for all sample sites. (4) In the urbanized Ouseburn catchment, although many sample sites also show this same mixing trend, some tributaries follow a pollutant trend of simultaneous increases in both DOC and DIC. The Ouseburn is part of the larger Tyne catchment: this larger catchment follows the simple groundwater DIC- soil water DOC end member mixing model, with the exception of the urban catchments which exhibit an elevated DIC compared to rural sites. (5) Urbanization is demonstrated to increase DIC compared to equivalent rural catchments; this DIC has potential sources including diffuse source inputs from the dissolution of concrete, point sources such as trade effluents and landfill leachates, and bedrock derived carbonates relocated to the soil dissolution zone by urban development. (6) DIC in rural SW England demonstrates that spatial variability in DIC can be attributed to variations in geology; but that DIC concentrations in the SW England rivers dataset are typically lower than the urbanized Tyne catchments despite the presence of carbonate bedrock in many of the sample catchments in the SW England dataset. (7) Recent

Modelling the 13C and 12C isotopes of inorganic and organic carbon in the Baltic Sea

Science.gov (United States)

Gustafsson, Erik; Mörth, Carl-Magnus; Humborg, Christoph; Gustafsson, Bo G.

2015-08-01

In this study, 12C and 13C contents of all carbon containing state variables (dissolved inorganic and organic carbon, detrital carbon, and the carbon content of autotrophs and heterotrophs) have for the first time been explicitly included in a coupled physical-biogeochemical Baltic Sea model. Different processes in the carbon cycling have distinct fractionation values, resulting in specific isotopic fingerprints. Thus, in addition to simulating concentrations of different tracers, our new model formulation improves the possibility to constrain the rates of processes such as CO2 assimilation, mineralization, and air-sea exchange. We demonstrate that phytoplankton production and respiration, and the related air-sea CO2 fluxes, are to a large degree controlling the isotopic composition of organic and inorganic carbon in the system. The isotopic composition is further, but to a lesser extent, influenced by river loads and deep water inflows as well as transformation of terrestrial organic carbon within the system. Changes in the isotopic composition over the 20th century have been dominated by two processes - the preferential release of 12C to the atmosphere in association with fossil fuel burning, and the eutrophication of the Baltic Sea related to increased nutrient loads under the second half of the century.

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.

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...

Coulometric precise analysis of total inorganic carbon in seawater and measurements of radiocarbon for the carbon dioxide in the atmosphere and for the total inorganic carbon in seawater

International Nuclear Information System (INIS)

Ishii, Masao; Inoue, Hisayuki Y.; Matsueda Hidekazu

2000-01-01

Climate change is one of the biggest issues on the earth, and the research on the climate system has been paid much attention today. The behavior of carbon dioxide (Co 2 ), one of the major green house gases, and its related substances within and among the atmosphere, the ocean and the land biosphere is playing a key role in regulating the climate. The ocean contains ca. 4x10 19 g of carbon, which is about 50 times of that in the atmosphere. The change in carbon cycle in the ocean is considered to have a crucial impact on the concentration of CO 2 in the atmosphere. However, little has been quantitatively known about the variability of CO 2 in the ocean and its controlling physical, chemical and biological processes. The observations of the concentration and carbon isotopic ratio of total dissolved inorganic carbon (TCO 2 ) in seawater occupy important part of the research on the behavior of carbon in the ocean. In the first part of this report, we describe the fundamental knowledge of CO 2 system in seawater and the method to precisely measure TCO 2 including sampling method, the structure and the operation of the instrument we developed, and the way to assure the quality of the data. We also present some results we obtained in the western North Pacific and the equatorial Pacific. In the second part, we report the methods to collect and treat samples for the analysis of the isotopic ratio of radio carbon ( 14 C) in the atmospheric CO 2 and TCO 2 in sea water. (author)

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

International Nuclear Information System (INIS)

Amiro, B.D.; Ewing, L.L.

1992-01-01

The uptake of inorganic 14 C by bean plant roots was measured. The plants were grown in a nutrient solution culture at pH 6 and a NaH 14 CO 3 tracer was added to the growth medium. Photosynthesis and transpiration were varied by exposing the aerial portions of the plants to different atmospheric CO 2 concentrations, humidities and light levels in a cuvette system. Leaf concentrations of 14 C were measured at the end of the experiments using liquid scintillation counting. Plant uptake of 14 C 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, 14 C 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 14 C transport from contaminated soils to biota. Also, the independence of the uptake from photosynthesis and ambient CO 2 concentrations suggests that future increases in atmospheric CO 2 concentrations may not have a direct effect on root uptake of soil carbon. (author)

Concentrations of polycyclic aromatic hydrocarbons and inorganic constituents in ambient surface soils, Chicago, Illinois: 2001-2002

Science.gov (United States)

Kay, R.T.; Arnold, T.L.; Cannon, W.F.; Graham, D.

2008-01-01

Samples of ambient surface soils were collected from 56 locations in Chicago, Illinois, using stratified random sampling techniques and analyzed for polycyclic aromatic hydrocarbon (PAH) compounds and inorganic constituents. PAHs appear to be derived primarily from combustion of fossil fuels and may be affected by proximity to industrial operations, but do not appear to be substantially affected by the organic carbon content of the soil, proximity to nonindustrial land uses, or proximity to a roadway. Atmospheric settling of particulate matter appears to be an important mechanism for the placement of PAH compounds into soils. Concentrations of most inorganic constituents are affected primarily by soil-forming processes. Concentrations of lead, arsenic, mercury, calcium, magnesium, phosphorus, copper, molybdenum, zinc, and selenium are elevated in ambient surface soils in Chicago in comparison to the surrounding area, indicating anthropogenic sources for these elements in Chicago soils. Concentrations of calcium and magnesium in Chicago soils appear to reflect the influence of the carbonate bedrock parent material on the chemical composition of the soil, although the effects of concrete and road fill cannot be discounted. Concentrations of inorganic constituents appear to be largely unaffected by the type of nearby land use. Copyright ?? Taylor & Francis Group, LLC.

Inorganic-whisker-reinforced polymer composites synthesis, properties and applications

CERN Document Server

Sun, Qiuju

2015-01-01

Inorganic-Whisker-Reinforced Polymer Composites: Synthesis, Properties and Applications gives a comprehensive presentation of inorganic microcrystalline fibers, or whiskers, a polymer composite filler. It covers whisker synthesis, surface modification, applications for reinforcing polymer-matrix composites, and analysis of resulting filled polymer composites. It focuses on calcium carbonate whiskers as a primary case study, introducing surface treatment methods for calcium carbonate whiskers and factors that influence them. Along with calcium carbonate, the book discusses potassium titanate and aluminum borate whiskers, which also comprise the new generation of inorganic whiskers. According to research results, composites filled by inorganic whiskers show improved strength, wear-resistance, thermal conductivity, and antistatic properties. It explains the importance of modifying polymer materials for use with inorganic whiskers and describes preparation and evaluation methods of polymers filled with inorganic ...

Sources and fluxes of inorganic carbon in a deep, oligotrophic lake (Loch Ness, Scotland)

Science.gov (United States)

Jones, R. I.; Grey, J.; Quarmby, Christopher; Sleep, Darren

2001-12-01

The main river inflows to Loch Ness and several depths in the water column within the loch were sampled over an annual cycle. The carbon isotope composition of total dissolved inorganic carbon (DIC) from the samples was determined as well as that of phytoplankton from the loch. Values of δ13C for DIC in the rivers indicated that this DIC was derived from soil respiration in the catchment and achieved only partial equilibrium with the atmosphere during river transport. Riverine loading accounted for most of the DIC in Loch Ness, and the great depth of the loch relative to its surface area allows only limited exchange with the atmosphere. Despite the low productivity in Loch Ness, DIC concentrations in the low alkalinity water are appreciably influenced by plankton metabolism, and seasonal fluctuations in δ13C of DIC and phytoplankton revealed the particular impact of photosynthetic carbon fixation on DIC. However, the photosynthetic depletion of DIC during summer does not offset the riverine loading sufficiently to prevent the loch waters being supersaturated with CO2 throughout the year. Annual efflux of CO2 from Loch Ness is estimated to be 253 × 106 mol yr-1, of which around one quarter may be due to net heterotrophic mineralization within the loch of organic carbon of terrestrial origin. The remainder is attributable to inorganic carbon input to the lake via river inflow and derived from prior mineralization of soil organic matter within the drainage area. This annual efflux of CO2 can represent around 6% of net ecosystem production in the catchment.

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

International Nuclear Information System (INIS)

Al-Dulaimi, A.A.; Shahrir Hashim; Khan, M.I.

2011-01-01

Two inorganic pigments (TiO 2 and SiO 2 ) were used to prepare composites with poly aniline (PANI) by situ polymerization method. PANI and PANI composites with SiO 2 and TiO 2 were characterized using Fourier transform infrared spectroscopy and X-ray diffraction. The morphology of the synthesized pigments (PANI , PANI-SiO 2 and PANI-TiO 2 ) 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-SiO 2 composite was more efficient in corrosion protection for carbon steel compared with the other synthesized pigments. (author)

Seasonal variability of the inorganic carbon system in a large coastal plain estuary

Science.gov (United States)

Joesoef, Andrew; Kirchman, David L.; Sommerfield, Christopher K.; Cai, Wei-Jun

2017-11-01

Carbonate geochemistry research in large estuarine systems is limited. More work is needed to understand how changes in land-use activity influence watershed export of organic and inorganic carbon, acids, and nutrients to the coastal ocean. To investigate the seasonal variation of the inorganic carbon system in the Delaware Estuary, one of the largest estuaries along the US east coast, dissolved inorganic carbon (DIC), total alkalinity (TA), and pH were measured along the estuary from June 2013 to April 2015. In addition, DIC, TA, and pH were periodically measured from March to October 2015 in the nontidal freshwater Delaware, Schuylkill, and Christina rivers over a range of discharge conditions. There were strong negative relationships between river TA and discharge, suggesting that changes in HCO3- concentrations reflect dilution of weathering products in the drainage basin. The ratio of DIC to TA, an understudied but important property, was high (1.11) during high discharge and low (0.94) during low discharge, reflecting additional DIC input in the form of carbon dioxide (CO2), most likely from terrestrial organic matter decomposition, rather than bicarbonate (HCO3-) inputs due to drainage basin weathering processes. This is also a result of CO2 loss to the atmosphere due to rapid water transit during the wet season. Our data further show that elevated DIC in the Schuylkill River is substantially different than that in the Delaware River. Thus, tributary contributions must be considered when attributing estuarine DIC sources to the internal carbon cycle versus external processes such as drainage basin mineralogy, weathering intensity, and discharge patterns. Long-term records in the Delaware and Schuylkill rivers indicate shifts toward higher alkalinity in estuarine waters over time, as has been found in other estuaries worldwide. Annual DIC input flux to the estuary and export flux to the coastal ocean are estimated to be 15.7 ± 8.2 × 109 mol C yr-1 and 16

Seasonal variability of the inorganic carbon system in a large coastal plain estuary

Directory of Open Access Journals (Sweden)

A. Joesoef

2017-11-01

Full Text Available Carbonate geochemistry research in large estuarine systems is limited. More work is needed to understand how changes in land-use activity influence watershed export of organic and inorganic carbon, acids, and nutrients to the coastal ocean. To investigate the seasonal variation of the inorganic carbon system in the Delaware Estuary, one of the largest estuaries along the US east coast, dissolved inorganic carbon (DIC, total alkalinity (TA, and pH were measured along the estuary from June 2013 to April 2015. In addition, DIC, TA, and pH were periodically measured from March to October 2015 in the nontidal freshwater Delaware, Schuylkill, and Christina rivers over a range of discharge conditions. There were strong negative relationships between river TA and discharge, suggesting that changes in HCO3− concentrations reflect dilution of weathering products in the drainage basin. The ratio of DIC to TA, an understudied but important property, was high (1.11 during high discharge and low (0.94 during low discharge, reflecting additional DIC input in the form of carbon dioxide (CO2, most likely from terrestrial organic matter decomposition, rather than bicarbonate (HCO3− inputs due to drainage basin weathering processes. This is also a result of CO2 loss to the atmosphere due to rapid water transit during the wet season. Our data further show that elevated DIC in the Schuylkill River is substantially different than that in the Delaware River. Thus, tributary contributions must be considered when attributing estuarine DIC sources to the internal carbon cycle versus external processes such as drainage basin mineralogy, weathering intensity, and discharge patterns. Long-term records in the Delaware and Schuylkill rivers indicate shifts toward higher alkalinity in estuarine waters over time, as has been found in other estuaries worldwide. Annual DIC input flux to the estuary and export flux to the coastal ocean are estimated to be 15.7 ± 8.2�

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. [...

Abiotic synthesis of organic compounds from carbon disulfide under hydrothermal conditions.

Science.gov (United States)

Rushdi, Ahmed I; Simoneit, Bernd R T

2005-12-01

Abiotic formation of organic compounds under hydrothermal conditions is of interest to bio, geo-, and cosmochemists. Oceanic sulfur-rich hydrothermal systems have been proposed as settings for the abiotic synthesis of organic compounds. Carbon disulfide is a common component of magmatic and hot spring gases, and is present in marine and terrestrial hydrothermal systems. Thus, its reactivity should be considered as another carbon source in addition to carbon dioxide in reductive aqueous thermosynthesis. We have examined the formation of organic compounds in aqueous solutions of carbon disulfide and oxalic acid at 175 degrees C for 5 and 72 h. The synthesis products from carbon disulfide in acidic aqueous solutions yielded a series of organic sulfur compounds. The major compounds after 5 h of reaction included dimethyl polysulfides (54.5%), methyl perthioacetate (27.6%), dimethyl trithiocarbonate (6.8%), trithianes (2.7%), hexathiepane (1.4%), trithiolanes (0.8%), and trithiacycloheptanes (0.3%). The main compounds after 72 h of reaction consisted of trithiacycloheptanes (39.4%), pentathiepane (11.6%), tetrathiocyclooctanes (11.5%), trithiolanes (10.6%), tetrathianes (4.4%), trithianes (1.2%), dimethyl trisulfide (1.1%), and numerous minor compounds. It is concluded that the abiotic formation of aliphatic straight-chain and cyclic polysulfides is possible under hydrothermal conditions and warrants further studies.

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)

Inorganic Carbon and Oxygen Dynamics in a Marsh-dominated Estuary

Science.gov (United States)

Wang, S. R.; Di Iorio, D.; Cai, W. J.; Hopkinson, C.

2017-12-01

A free-water mass balance-based study was conducted to address the rate of metabolism and net carbon exchange for the tidal wetland and estuarine portion of the coastal ocean and the uncertainties associated with this approach were assessed. Open water diurnal O2 and dissolved inorganic carbon (DIC) were measured seasonally in a salt marsh-estuary in Georgia, U.S.A. with a focus on the marsh-estuary linkage associated with tidal flooding. We observed that the overall estuarine system was a net source of CO2 to the atmosphere and coastal ocean and a net sink for oceanic and atmospheric O2. Rates of metabolism were extremely high, with respiration (43 mol m-2 yr-1) greatly exceeding gross primary production (28 mol m-2 yr-1), such that the overall system was net heterotrophic. Metabolism measured with DIC were higher than with O2, which we attribute to high rates of anaerobic respiration and reduced sulfur storage in salt marsh sediments, and we assume substantial levels of anoxygenic photosynthesis. We found gas exchange from a flooded marsh is substantial, accounting for about 28% of total O2 and CO2 air-water exchange. A significant percentage of the overall estuarine aquatic metabolism is attributable to metabolism of marsh organisms during inundation. Our study suggests not rely on oceanographic stoichiometry to convert from O2to C based measurements when constructing C balances for the coastal ocean. We also suggest eddy covariance measurements of salt marsh net ecosystem exchange underestimate net ecosystem production as they do not account for lateral DIC exchange associated with marsh tidal inundation. With the increase of global temperature and sea level rise, salt marshes are likely to export more inorganic carbon to the atmosphere and the coastal ocean due to the decrease of solubility, the increase of aquatic and benthic metabolic activities and the longer marsh inundation.

Critical review of animal carcinogenesis by cadmium and its inorganic compounds

International Nuclear Information System (INIS)

Maximilien, R.; Dero, B.

1990-01-01

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

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...... included. The model is evaluated using observations from a 6 month field study at Point Barrow, Alaska, and an ice-tank experi- ment. At Barrow, results show that the DIC budget is mainly driven by physical processes, wheras brine-air CO2 fluxes, ikaite formation, and net primary production, are secondary...

Inorganic Carbon Utilization of the Freshwater Red Alga Compsopogon coeruleus (Balbis Montagne (Compsopogonaceae, Rhodophyta Evaluated by in situ Measurement of Chlorophyll Fluorescence

Directory of Open Access Journals (Sweden)

Shao-Lun Liu

2004-09-01

Full Text Available To explore the inorganic carbon utilization of the freshwater red alga Compsopogon coeruleus, photosynthetic rates in response to increasing of bicarbonate concentration, the addition of alkaline HEPES buffer (pH 8.8, acid HEPES buffer (pH 4.0 and the extracellular carbonic anhydrase inhibitor (acetazolamide, AZ, respectively, were examined in situ by using a submersible pulse amplitude modulated (PAM fluorometer. Among the treatments, adding acid HEPES buffer significantly reduced photosynthetic rates of the alga, while others showed no effect. Accordingly, we concluded that C. coeruleus had less or no inorganic carbon (Ci limitation in its natural habitat. The alga might have higher affinity for bicarbonate and directly uptake bicarbonate as main Ci source without the aid of extracellular carbonic anhydrase.

The electronic structure of organic-inorganic hybrid compounds : (NH4)(2)CuCl4, (CH3NH3)(2)CuCl4 and (C2H5NH3)(2)CuCl4

NARCIS (Netherlands)

Zolfaghari, P.; de Wijs, G. A.; de Groot, R. A.

2013-01-01

Hybrid organic-inorganic compounds are an intriguing class of materials that have been experimentally studied over the past few years because of a potential broad range of applications. The electronic and magnetic properties of three organic-inorganic hybrid compounds with compositions

In situ spectrophotometric measurement of dissolved inorganic carbon in seawater

Science.gov (United States)

Liua, Xuewu; Byrne, Robert H.; Adornato, Lori; Yates, Kimberly K.; Kaltenbacher, Eric; Ding, Xiaoling; Yang, Bo

2013-01-01

Autonomous in situ sensors are needed to document the effects of today’s rapid ocean uptake of atmospheric carbon dioxide (e.g., ocean acidification). General environmental conditions (e.g., biofouling, turbidity) and carbon-specific conditions (e.g., wide diel variations) present significant challenges to acquiring long-term measurements of dissolved inorganic carbon (DIC) with satisfactory accuracy and resolution. SEAS-DIC is a new in situ instrument designed to provide calibrated, high-frequency, long-term measurements of DIC in marine and fresh waters. Sample water is first acidified to convert all DIC to carbon dioxide (CO2). The sample and a known reagent solution are then equilibrated across a gas-permeable membrane. Spectrophotometric measurement of reagent pH can thereby determine the sample DIC over a wide dynamic range, with inherent calibration provided by the pH indicator’s molecular characteristics. Field trials indicate that SEAS-DIC performs well in biofouling and turbid waters, with a DIC accuracy and precision of ∼2 μmol kg–1 and a measurement rate of approximately once per minute. The acidic reagent protects the sensor cell from biofouling, and the gas-permeable membrane excludes particulates from the optical path. This instrument, the first spectrophotometric system capable of automated in situ DIC measurements, positions DIC to become a key parameter for in situ CO2-system characterizations.

Comparing carbon to carbon: Organic and inorganic carbon balances across nitrogen fertilization gradients in rainfed vs. irrigated Midwest US cropland

Science.gov (United States)

Hamilton, S. K.; McGill, B.

2017-12-01

The top meter of the earth's soil contains about twice the amount of carbon than the atmosphere. Agricultural management practices influence whether a cropland soil is a net carbon source or sink. These practices affect both organic and inorganic carbon cycling although the vast majority of studies examine the former. We will present results from several rarely-compared carbon fluxes: carbon dioxide emissions and sequestration from lime (calcium carbonate) weathering, dissolved gases emitted from groundwater-fed irrigation, dissolved organic carbon (DOC) leaching to groundwater, and soil organic matter storage. These were compared in a corn-soybean-wheat rotation under no-till management across a nitrogen fertilizer gradient where half of the replicated blocks are irrigated with groundwater. DOC and liming fluxes are also estimated from a complementary study in neighboring plots comparing a gradient of management practices from conventional to biologically-based annuals and perennials. These studies were conducted at the Kellogg Biological Station Long Term Ecological Research site in Michigan where previous work estimated that carbon dioxide emissions from liming accounted for about one quarter of the total global warming impact (GWI) from no-till systems—our work refines that figure. We will present a first time look at the GWI of gases dissolved in groundwater that are emitted when the water equilibrates with the atmosphere. We will explore whether nitrogen fertilizer and irrigation increase soil organic carbon sequestration by producing greater crop biomass and residues or if they enhance microbial activity, increasing decomposition of organic matter. These results are critical for more accurately estimating how intensive agricultural practices affect the carbon balance of cropping systems.

Carbon isotopic fractionation in live benthic foraminifera -comparison with inorganic precipitate studies

Energy Technology Data Exchange (ETDEWEB)

Grossmann, E L [University of Southern California, Los Angeles (USA). Dept. of Geological Sciences

1984-07-01

Carbon and oxygen isotopic analyses have been performed on live-stained aragonitic and calcitic benthic foraminifera and dissolved inorganic carbon from the Southern California Borderland to examine carbon isotopic fractionation in foraminifera. Temperature, salinity and pH data have also been collected to permit accurate determination of the delta/sup 13/C of bicarbonate ion and thus aragonite-HCO/sub 3//sup -/ and calcite-HCO/sub 3//sup -/ isotopic enrichment factors (epsilonsub(ar-b) and epsilonsub(cl-b), respectively). Only species which precipitate in /sup 18/O equilibrium have been considered. epsilonsub (ar-b) values based on Hoeglundina elegans range from 1.9 per mille at 2.7 deg C to 1.1 per mille at 9.5 deg C. The temperature dependence of epsilonsub(ar-b) is considerably greater than the equilibrium equation would predict and may be due to a vital effect. The calcitic foraminifera Cassidulina tortuosa, Cassidulina braziliensis, and Cassidulina limbata, Bank and Terrace dwellers, have s

Carbon determination in uranium and its compounds

International Nuclear Information System (INIS)

Silva Queiroz, C.A. da; Abrao, A.

1982-01-01

Carbon content in uranium and its compounds, especially ceramic grade UO 2 , must be controlled rigorously. A method for the determination of carbon with the aid of commercial equipment which uses platinum as a catalyst for the oxidation of CO, and infrared cells for CO 2 measurement is described. The detection limit is 5μg C/g U and the determination range is 0.0005 to 5% C/U. The method is being used routinely to control the carbon content in nuclear fuel materials. (Author) [pt

Distribution of dissolved inorganic carbon and related parameters in the Thermaikos Gulf (Eastern Mediterranean

Directory of Open Access Journals (Sweden)

E. KRASAKOPOULOU

2006-06-01

Full Text Available Data on the distribution of dissolved inorganic carbon (measured as TCO2 and related parameters in the Thermaikos Gulf were obtained during May 1997. High TCO2 concentrations were recorded close to the bottom, especially in the northern part of the gulf, as a result of organic matter remineralisation. The positive relatively good correlation between TCO2 and both apparent oxygen utilisation (AOU and phosphate at the last sampling depth confi rmed the regenerative origin of a large proportion of TCO2. The comparatively conservative behaviour of alkalinity, together with the relatively low value of the homogenous buffer factor β (β = ∂lnfCO2/∂lnTCO2 revealed that calcifi cation or carbonate dissolution takes place on a very small scale, simultaneously with the organic carbon production. The correlations between fCO2 and chlorophyll α, as well as AOU and the surface temperature, revealed that the carbon dioxide fi xation through the biological activity is the principal factor that modulates the variability of fCO2. A rough first estimate of the magnitude of the air-sea CO2 exchange and the potential role of the Thermaikos Gulf in the transfer of atmospheric CO2 was also obtained. The results showed that during May 1997, the Thermaikos Gulf acted as a weak sink for atmospheric CO2 at a rate of -0.60 - -1.43 mmol m-2 d-1, depending on which formula for the gas transfer velocity was used, and in accordance to recent reports regarding other temperate continental shelves. Extensive study of the dissolved inorganic carbon and related parameters, and continuous shipboard measurements of fCO2 a and fCO2 w during all seasons are necessary to safely quantify the role of the Thermaikos Gulf in the context of the coastal margins CO2 dynamics.

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

Science.gov (United States)

Sekaran, G; Karthikeyan, S; Gupta, V K; Boopathy, R; Maharaja, P

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 °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 JK(-1)mol(-1) respectively at pH 7.0, temperature 20 °C and particle size 300 μm. Higher values of ΔH(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 × 10(-2) min(-1). Copyright © 2012 Elsevier B.V. All rights reserved.

Enhancing Optically Pumped Organic-Inorganic Hybrid Perovskite Amplified Spontaneous Emission via Compound Surface Plasmon Resonance

Directory of Open Access Journals (Sweden)

Xiaoyan Wu

2018-03-01

Full Text Available Organic-inorganic hybrid perovskite has attracted intensive attention from researchers as the gain medium in lasing devices. However, achieving electrically driven lasing remains a significant challenge. Modifying the devices’ structure to enhance the optically pumped amplified spontaneous emission (ASE is the key issue. In this work, gold nanoparticles (Au NPs are first doped into PEDOT: PSS buffer layer in a slab waveguide device structure: Quartz/PEDOT: PSS (with or w/o Au NPs/CH3NH3PbBr3. As a result, the facile device shows a significantly enhanced ASE intensity and a narrowed full width at half maximum. Based on experiments and theoretical simulation data, the improvement is mainly a result of the compound surface plasmon resonance, including simultaneous near- and far-field effects, both of which could increase the density of excitons excited state and accelerate the radiative decay process. This method is highly significant for the design and development and fabrication of high-performance organic-inorganic hybrid perovskite lasing diodes.

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.

of high phytoplankton biomass. Dissolved inorganic carbon (DIC) was higher in the frontal zone by 3 to 41.5 Mu M than outside. The salinity normalized DIC displayed linear relation with Chl-a and inverse correlation with dissolved oxygen saturation...

Dynamics regulating major trends in Barents Sea temperatures and subsequent effect on remotely sensed particulate inorganic carbon

DEFF Research Database (Denmark)

Hovland, Erlend Kjeldsberg; Dierssen, Heidi M.; Ferreira, Ana Sofia

2013-01-01

A more comprehensive understanding of how ocean temperatures influence coccolithophorid production of particulate inorganic carbon (PIC) will make it easier to constrain the effect of ocean acidification in the future. We studied the effect of temperature on Emiliania huxleyi PIC production...

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.

Controlling the release of active compounds from the inorganic carrier halloysite

International Nuclear Information System (INIS)

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

2014-01-01

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

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

International Nuclear Information System (INIS)

Ghafari, Shahin; Hasan, Masitah; Aroua, Mohamed Kheireddine

2009-01-01

Acclimation of autohydrogenotrophic denitrifying bacteria using inorganic carbon source (CO 2 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 CO 2 , (II) bicarbonate plus continuous sparging of CO 2 , and (III) only bicarbonate. The pH-reducing nature of CO 2 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 NO 3 - -N/g MLVSS/h for degrading 20 and 30 mg NO 3 - -N/L and 9.09 mg NO 3 - -N/g MLVSS/h for degrading 50 mg NO 3 - -N/L

Fate of Trace Organic Compounds in Granular Activated Carbon (GAC Adsorbers for Drinking Water Treatment

Directory of Open Access Journals (Sweden)

Alexander Sperlich

2017-06-01

Full Text Available Granular activated carbon (GAC adsorbers for drinking water treatment were operated for approx. 14 months and the breakthrough of dissolved organic carbon (DOC and trace organic chemicals (TOrCs was monitored. Effluent concentration profiles of gabapentin and valsartan acid increase already at throughputs of <10,000 BV. The corresponding breakthrough curves flatten out without reaching the influent concentration level. This strongly indicates biological degradation of these substances in the GAC adsorbers under aerobic conditions, contributing to a more efficient use of GAC. The observed biodegradation in pilot GAC adsorbers also confirms recent reports of biodegradation of gabapentin and valsartan acid during managed aquifer recharge. Oxypurinol is comparatively well adsorbed and no breakthrough was observed during the experimental period. Adsorption capacity and breakthrough characteristics of oxypurinol appear very similar to carbamazepine. Breakthrough of GAC adsorbers operated with drinking water was compared to those of groundwater-fed adsorbers. The results show, that it is generally advisable to use previously aerated influents for GAC fixed-bed adsorbers because this can substantially improve biological removal of otherwise poorly adsorbable compounds and ensure full GAC accessibility for adsorbates by avoiding the undesirable formation of inorganic precipitates on adsorption sites.

Effect of inorganic nutrients on relative contributions of fungi and bacteria to carbon flow from submerged decomposing leaf litter

Science.gov (United States)

Vladislav Gulis; Keller Suberkropp

2003-01-01

The relative contributions of fungi and bacteria to carbon flow from submerged decaying plant litter at different levels of inorganic nutrients (N and P) were studied. We estimated leaf mass loss, fungal and bacterial biomass and production, and microbial respiration and constructed partial carbon budgets for red maple leaf disks precolonized in a stream and then...

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

International Nuclear Information System (INIS)

Kamaruzaman Mohamad; Rohaimah Demanah; Juhari Mohd Yusof; Roslanzairi Mostapa

2009-01-01

This paperwork explain the method of water sampling to obtain the precipitate of BaCO 3 solutions that will be used to analyze 13 C 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 BaCO 3 for 13 C 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)

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)

Tue-Ngeun, Orawan; Sandford, Richard C.; Jakmunee, Jaroon; Grudpan, Kate; McKelvie, Ian D.; Worsfold, Paul J.

2005-01-01

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 CO 2 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 CO 2 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)

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

Energy Technology Data Exchange (ETDEWEB)

Tue-Ngeun, Orawan [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Sandford, Richard C. [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drakes Circus, Plymouth PL4 8AA (United Kingdom)]. E-mail: rsandford@plymouth.ac.uk; Jakmunee, Jaroon [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Grudpan, Kate [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); McKelvie, Ian D. [Water Studies Centre, School of Chemistry, Monash University, P.O. Box 23, Clayton Campus, Vic. 3800 (Australia); Worsfold, Paul J. [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drakes Circus, Plymouth PL4 8AA (United Kingdom)

2005-12-04

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), converted DIC to CO{sub 2} which subsequently diffused through a PTFE membrane into a basic, cresol red acceptor stream. The CO{sub 2} 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 CO{sub 2} 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{sup -1} for both DIC and DIC + DOC, with typical R.S.D.s of less than 7% (0.05 mg C L{sup -1}-5.3% for DIC and 6.6% for DIC + DOC; 4.0 mg C L{sup -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{sup -1}. Sample throughput for the automated system was 8 h{sup -1} for DIC and DOC with low reagent consumption (acid/peroxydisulfate 200 {mu}L 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)

Nitrogen-doped ordered mesoporous carbon with a high surface area, synthesized through organic-inorganic coassembly, and its application in supercapacitors.

Science.gov (United States)

Song, Yanfang; Li, Li; Wang, Yonggang; Wang, Congxiao; Guo, Zaipin; Xia, Yongyao

2014-07-21

A new nitrogen-doped ordered mesoporous carbon (N-doped OMC) is synthesized by using an organic-inorganic coassembly method, in which resol is used as the carbon precursor, dicyandiamide as the nitrogen precursor, silicate oligomers as the inorganic precursors, and F127 as the soft template. The N-doped OMC possesses a surface area as high as 1374 m(2)  g(-1) and a large pore size of 7.4 nm. As an electrode material for supercapacitors, the obtained carbon exhibits excellent cycling stability and delivers a reversible specific capacitance as high as 308 F g(-1) in 1 mol L(-1) H(2)SO(4) aqueous electrolyte, of which 58 % of the capacity is due to pseudo-capacitance. The large specific capacitance is attributed to proper pore size distributions, large surface area, and high nitrogen content. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Heterogeneous Catalysis of Polyoxometalate Based Organic–Inorganic Hybrids

Directory of Open Access Journals (Sweden)

Yuanhang Ren

2015-03-01

Full Text Available Organic–inorganic hybrid polyoxometalate (POM compounds are a subset of materials with unique structures and physical/chemical properties. The combination of metal-organic coordination complexes with classical POMs not only provides a powerful way to gain multifarious new compounds but also affords a new method to modify and functionalize POMs. In parallel with the many reports on the synthesis and structure of new hybrid POM compounds, the application of these compounds for heterogeneous catalysis has also attracted considerable attention. The hybrid POM compounds show noteworthy catalytic performance in acid, oxidation, and even in asymmetric catalytic reactions. This review summarizes the design and synthesis of organic–inorganic hybrid POM compounds and particularly highlights their recent progress in heterogeneous catalysis.

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

Energy Technology Data Exchange (ETDEWEB)

Ghafari, Shahin; Hasan, Masitah [Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Aroua, Mohamed Kheireddine [Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia)], E-mail: mk_aroua@um.edu.my

2009-03-15

Acclimation of autohydrogenotrophic denitrifying bacteria using inorganic carbon source (CO{sub 2} 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 CO{sub 2}, (II) bicarbonate plus continuous sparging of CO{sub 2}, and (III) only bicarbonate. The pH-reducing nature of CO{sub 2} 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 NO{sub 3}{sup -}-N/g MLVSS/h for degrading 20 and 30 mg NO{sub 3}{sup -}-N/L and 9.09 mg NO{sub 3}{sup -}-N/g MLVSS/h for degrading 50 mg NO{sub 3}{sup -}-N/L.

Carbon-Electrode-Tailored All-Inorganic Perovskite Solar Cells To Harvest Solar and Water-Vapor Energy.

Science.gov (United States)

Duan, Jialong; Hu, Tianyu; Zhao, Yuanyuan; He, Benlin; Tang, Qunwei

2018-05-14

Moisture is the worst enemy for state-of-the-art perovskite solar cells (PSCs). However, the flowing water vapor within nanoporous carbonaceous materials can create potentials. Therefore, it is a challenge to integrate water vapor and solar energies into a single PSC device. We demonstrate herein all-inorganic cesium lead bromide (CsPbBr 3 ) solar cells tailored with carbon electrodes to simultaneously harvest solar and water-vapor energy. Upon interfacial modification and plasma treatment, the bifunctional PSCs yield a maximum power conversion efficiency up to 9.43 % under one sun irradiation according to photoelectric conversion principle and a power output of 0.158 μW with voltage of 0.35 V and current of 0.45 μA in 80 % relative humidity through the flowing potentials at the carbon/water interface. The initial efficiency is only reduced by 2 % on exposing the inorganic PSC with 80 % humidity over 40 days. The successful realization of physical proof-of-concept multi-energy integrated solar cells provides new opportunities of maximizing overall power output. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Understanding the carbon cycle in a Late Quaternary-age limestone aquifer system using radiocarbon of dissolved inorganic and organic carbon

Science.gov (United States)

Bryan, Eliza; Meredith, Karina T.; Baker, Andy; Andersen, Martin S.; Post, Vincent E. A.

2017-04-01

Estimating groundwater residence time is critical for our understanding of hydrogeological systems, for groundwater resource assessments and for the sustainable management of groundwater resources. Due to its capacity to date groundwater up to 30 thousand years old, as well as the ubiquitous nature of dissolved carbon (as organic and inorganic forms) in groundwater, 14C is the most widely used radiogenic dating technique in regional aquifers. However, the geochemistry of carbon in groundwater systems includes interaction with the atmosphere, biosphere and geosphere, which results in multiple sources and sinks of carbon that vary in time and space. Identifying these sources of carbon and processes relating to its release or removal is important for understanding the evolution of the groundwater and essential for residence time calculations. This study investigates both the inorganic and organic facets of the carbon cycle in groundwaters throughout a freshwater lens and mixing zone of a carbonate island aquifer and identifies the sources of carbon that contribute to the groundwater system. Groundwater samples were collected from shallow (5-20 m) groundwater wells on a small carbonate Island in Western Australia in September 2014 and analysed for major and minor ions, stable water isotopes (SWIs: δ18O, δ2H), 3H, 14C and 13C carbon isotope values of both DIC and DOC, and 3H. The composition of groundwater DOC was investigated by Liquid Chromatography-Organic Carbon Detection (LC-OCD) analysis. The presence of 3H (0.12 to 1.35 TU) in most samples indicates that groundwaters on the Island are modern, however the measured 14CDIC values (8.4 to 97.2 pmc) suggest that most samples are significantly older due to carbonate dissolution and recrystallisation reactions that are identified and quantified in this work. 14CDOC values (46.6 to 105.6 pMC) were higher than 14CDIC values and were well correlated with 3H values, however deeper groundwaters had lower 14CDOC values than

Human Exposure and Health Effects of Inorganic and Elemental Mercury

Science.gov (United States)

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 of 7% to 15% after ingestion; they are also irritants and cause gastrointestinal symptoms. Upon entering the body, inorganic mercury compounds are accumulated mainly in the kidneys and produce kidney damage. In contrast, human exposure to elemental mercury is mainly by inhalation, followed by rapid absorption and distribution in all major organs. Elemental mercury from ingestion is poorly absorbed with a bioavailability of less than 0.01%. The primary target organs of elemental mercury are the brain and kidney. Elemental mercury is lipid soluble and can cross the blood-brain barrier, while inorganic mercury compounds are not lipid soluble, rendering them unable to cross the blood-brain barrier. Elemental mercury may also enter the brain from the nasal cavity through the olfactory pathway. The blood mercury is a useful biomarker after short-term and high-level exposure, whereas the urine mercury is the ideal biomarker for long-term exposure to both elemental and inorganic mercury, and also as a good indicator of body burden. This review discusses the common sources of mercury exposure, skin lightening products containing mercury and mercury release from dental amalgam filling, two issues that happen in daily life, bear significant public health importance, and yet undergo extensive debate on their safety. PMID:23230464

Preliminary Study: Application of Off-Axis ICOS to Determine Stable Carbon Isotope in Dissolved Inorganic Carbon

Science.gov (United States)

Kim, Y. T.; Lee, J. M.; Hwang, J. H.; Piao, J.; Woo, N. C.

2015-12-01

CO2 is one of the major causes for global climate change. Because stable carbon isotope ratio is used to trace carbon source, several analytical techniques likes IRMS (Isotope Ratio Mass Spectrometry) and LAS (Laser Absorption Spectrometry) were extensively used. Off-axis ICOS, a kind of LAS, has merits on long-term stability and field application, therefore it is widely being used in CCS (Carbon Capture and Storage) field. The aim of this study is to extend the application scope of OA-ICOS to determine dissolved inorganic carbon (DIC). Because OA-ICOS showed dependence of δ13C on CO2 concentration, data processing is required. We tested CO2 Carbon Isotope Analyzer (CCIA-36-EP, Los Gatos Research) with both reference gas (δ13C= -28.28‰) and aqueous solutions prepared by dissolving sodium bicarbonate standards (δ13C= -12.26‰ and +3.96‰). The differences of δ13C between reference and measurement values are plotted by CO2 concentrations, then compared. At first, we checked the similarity between our curve pattern for reference gas and Guillon's research (δ13C= -43.99‰) by other Analyzer. To analyze aqueous samples, more errors can be caused than gas analysis. The carbon isotope fractionation occurs during dissolving standard reagents and extracting DIC as CO2 gas form. This effect is mixed with CO2 concentration dependence effect, therefore the curve patterns are different with that for reference gas. Our experiments are done for various δ13C values. It could be an important point to use OA-ICOS to analyze DIC, too.

Methods for Introducing Inorganic Polymer Concepts throughout the Undergraduate Curriculum

Science.gov (United States)

de Lill, Daniel T.; Carraher, Charles E., Jr.

2017-01-01

Inorganic polymers can be introduced in a variety of undergraduate courses to discuss concepts related to polymer chemistry. Inorganic polymers such as silicates and polysiloxanes are simple materials that can be incorporated into an introductory or descriptive inorganic course. Polymers based on inorganic carbon, including diamond and graphite,…

Growth limitation of three Arctic sea-ice algae species: effects of salinitty, pH and inorganic carbon availability

DEFF Research Database (Denmark)

Søgaard, Dorte Haubjerg; Hansen, Per Juel; Rysgaard, Søren

2011-01-01

The effect of salinity, pH, and dissolved inorganic carbon (TCO(2)) on growth and survival of three Arctic sea ice algal species, two diatoms (Fragilariopsis nana and Fragilariopsis sp.), and one species of chlorophyte (Chlamydomonas sp.) was assessed in controlled laboratory experiments. Our res...

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)...

Aerogel and xerogel composites for use as carbon anodes

Science.gov (United States)

Cooper, John F [Oakland, CA; Tillotson, Thomas M [Tracy, CA; Hrubesh, Lawrence W [Pleasanton, CA

2008-08-12

Disclosed herein are aerogel and xerogel composite materials suitable for use as anodes in fuel cells and batteries. Precursors to the aerogel and xerogel compounds are infused with inorganic polymeric materials or carbon particles and then gelled. The gels are then pyrolyzed to form composites with internal structural support.

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...... 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....

Sorption of Heterocyclic Organic Compounds to Multiwalled Carbon Nanotubes.

Science.gov (United States)

Metzelder, Florian; Funck, Matin; Schmidt, Torsten C

2018-01-16

Sorption is an important natural and technical process. Sorption coefficients are typically determined in batch experiments, but this may be challenging for weakly sorbing compounds. An alternative method enabling analysis of those compounds is column chromatography. A column packed with the sorbent is used and sorption data are determined by relating sorbate retention to that of a nonretarded tracer. In this study, column chromatography was applied for the first time to study sorption of previously hardly investigated heterocyclic organic compounds to multiwalled carbon nanotubes (MWCNTs). Sorption data for these compounds are very limited in literature, and weak sorption is expected from predictions. Deuterium oxide was used as nonretarded tracer. Sorption isotherms were well described by the Freundlich model and data showed reasonable agreement with predicted values. Sorption was exothermic and physisorption was observed. H-bonding may contribute to overall sorption, which is supported by reduced sorption with increasing ionic strength due to blocking of functional groups. Lowering pH reduced sorption of ionizable compounds, due to electrostatic repulsion at pH 3 where sorbent as well as sorbates were positively charged. Overall, column chromatography was successfully used to study sorption of heterocyclic compounds to MWCNTs and could be applied for other carbon-based sorbents.

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...... for leaching, was observed indicating that the number of analysed samples may be critical in relation to decisions regarding management and utilisation of the materials. Higher leaching of chromium, sulphate and chloride were observed for masonry-containing and partly carbonated samples, indicating that source...... 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....

A Statistical Learning Framework for Materials Science: Application to Elastic Moduli of k-nary Inorganic Polycrystalline Compounds.

Science.gov (United States)

de Jong, Maarten; Chen, Wei; Notestine, Randy; Persson, Kristin; Ceder, Gerbrand; Jain, Anubhav; Asta, Mark; Gamst, Anthony

2016-10-03

Materials scientists increasingly employ machine or statistical learning (SL) techniques to accelerate materials discovery and design. Such pursuits benefit from pooling training data across, and thus being able to generalize predictions over, k-nary compounds of diverse chemistries and structures. This work presents a SL framework that addresses challenges in materials science applications, where datasets are diverse but of modest size, and extreme values are often of interest. Our advances include the application of power or Hölder means to construct descriptors that generalize over chemistry and crystal structure, and the incorporation of multivariate local regression within a gradient boosting framework. The approach is demonstrated by developing SL models to predict bulk and shear moduli (K and G, respectively) for polycrystalline inorganic compounds, using 1,940 compounds from a growing database of calculated elastic moduli for metals, semiconductors and insulators. The usefulness of the models is illustrated by screening for superhard materials.

Adsorption of aromatic compounds from the biodegradation of azo dyes on activated carbon

Science.gov (United States)

Faria, P. C. C.; Órfão, J. J. M.; Figueiredo, J. L.; Pereira, M. F. R.

2008-03-01

The adsorption of three selected aromatic compounds (aniline, sulfanilic acid and benzenesulfonic acid) on activated carbons with different surface chemical properties was investigated at different solution pH. A fairly basic commercial activated carbon was modified by means of chemical treatment with HNO 3, yielding an acid activated carbon. The textural properties of this sample were not significantly changed after the oxidation treatment. Equilibrium isotherms of the selected compounds on the mentioned samples were obtained and the results were discussed in relation to their surface chemistry. The influence of electrostatic and dispersive interactions involved in the uptake of the compounds studied was evaluated. The Freundlich model was used to fit the experimental data. Higher uptakes are attained when the compounds are present in their molecular form. In general, adsorption was disfavoured by the introduction of oxygen-containing groups on the surface of the activated carbon.

Role of ozone and granular activated carbon in the removal of mutagenic compounds.

Science.gov (United States)

Bourbigot, M M; Hascoet, M C; Levi, Y; Erb, F; Pommery, N

1986-01-01

The identification of certain organic compounds in drinking water has led water treatment specialists to be increasingly concerned about the eventual risks of such pollutants to the health of consumers. Our experiments focused on the role of ozone and granular activated carbon in removing mutagenic compounds and precursors that become toxic after chlorination. We found that if a sufficient dose of ozone is applied, its use does not lead to the creation of mutagenic compounds in drinking water and can even eliminate the initial mutagenicity of the water. The formation of new mutagenic compounds seems to be induced by ozonation that is too weak, although these mutagens can be removed by GAC filtration. Ozone used with activated carbon can be one of the best means for eliminating the compounds contributing to the mutagenicity of water. A combined treatment of ozone and activated carbon also decreases the chlorine consumption of the treated water and consequently reduces the formation of chlorinated organic compounds. PMID:3816720

Inorganic carbon dynamics of melt pond-covered first year sea ice in the Canadian Arctic

DEFF Research Database (Denmark)

Geilfus, Nicolas-Xavier; Galley, R.J.; Crabeck, O.

2014-01-01

Melt pond formation is a common feature of the spring and summer Arctic sea ice. However, the role of the melt ponds formation and the impact of the sea ice melt on both the direction and size of CO2 flux between air and sea is still unknown. Here we describe the CO2-carbonate chemistry of melting...... a strong decrease of the total alkalinity (TA), total dissolved inorganic carbon (TCO2) and partial pressure of CO2 (pCO2) within the bulk sea ice and the brine. Later on, melt pond formation affects both the bulk sea ice and the brine system. As melt ponds are formed from melted snow the in situ melt pond...

Thermal stability of inorganic and organic compounds in atmospheric particulate matter

Science.gov (United States)

Perrino, Cinzia; Marconi, Elisabetta; Tofful, Luca; Farao, Carmela; Materazzi, Stefano; Canepari, Silvia

2012-07-01

The thermal behaviour of atmospheric particulate matter (PM) has been investigated by using different analytical approaches to explore the added value offered by these technique in environmental studies. The thermogravimetric analysis (TGA), carried out on both certified material and real PM samples, has shown that several mass losses can be detected starting from 80 °C up to above 500 °C, when pyrolysis occur. Thermo-optical analysis of PM and ion chromatographic analysis of the residual have shown that the mass losses in the temperature range 80-180 °C are not justified by the release of either organic or inorganic compounds; it can be thus attributed to the release of weakly and strongly bound water. Release of water has also been evidenced in the temperature range 225-275 °C. The release of ammonium chloride and nitrate has been detected only above 80 °C. This indicates that the release of nitric acid, hydrochloric acid and ammonia, which is observed downstream of the filters during the sampling of atmospheric PM at ambient temperature, cannot be reproduced off-line, after the end of the sampling. We successfully explored one of the possible explanations, that is the desorption of HNO3, HCl and NH3 adsorbed on collected particles. NH4NO3 and NH4Cl, which can be thermally released by the filter, exhibit a different thermal behaviour from NaNO3 and NaCl, which are thermally stable up to 370 °C. This different behaviour can be used to discriminate between natural and secondary sources of atmospheric inorganic salts, as the interconversion that is observed when heating mixtures of pure salts resulted to be not relevant when heating real PM samples.

Preparation of inorganic crystalline compounds induced by ionizing, UV and laser radiation

International Nuclear Information System (INIS)

Cuba, V.; Pavelkova, T.; Barta, J.; Indrei, J.; Gbur, T.; Pospisil, M.; Mucka, V.; Docekalova, Z.; Zavadilova, A.; Vlk, M.

2011-01-01

Complete text of publication follows. Radiation methods represent powerful tool for synthesis of various inorganic materials. Study of solid particles formation from solutions in the field of UV or ionizing radiation is one of the very promising and long term pursued trends in photochemistry and radiation chemistry. The motivation may be various, either preparation of new materials or removal of hazardous contaminants (e.g. heavy metals) from wastewater. This work deals with preparation of some metal oxides, synthetic garnets and spinel structures via irradiation of aqueous solutions containing precursors, i.e. soluble metal salts, radical scavengers and/or macromolecular stabilizers. Namely, results on radiation induced preparation of nickel, zinc, yttrium and aluminium oxides are summarized, as well as zinc peroxide, yttrium / lutetium - aluminium garnets and cobalt(II) aluminate. 60 Co irradiator, linear electron accelerator, medium pressure UV lamp and solid state laser were used as the sources of radiation. Aside from preparation, various physico-chemical and structural properties of compounds prepared were also studied. All used modifications of radiation method are rather convenient and simple, and yield (nano)powder materials with interesting characteristics. Prepared materials generally have high chemical purity, high specific surface area and narrow distribution of particles size (ranging in tens of nm). Generally, all types of irradiation result in materials with comparable properties and structural characteristics; but in the case of synthetic garnets and spinels, preparation using UV-radiation seems to be the most convenient for their preparation. Among compounds discussed, only zinc oxide and zinc peroxide were prepared directly via irradiation. For preparation of other crystalline compounds, additional heat treatment (at low temperature) of amorphous solid phase formed under irradiation was necessary.

High dark inorganic carbon fixation rates by specific microbial groups in the Atlantic off the Galician coast (NW Iberian margin)

NARCIS (Netherlands)

Guerrero-Feijóo, E.; Sintes, E.; Herndl, G.J.; Varela, M.M.

2018-01-01

Bulk dark dissolved inorganic carbon (DIC) fixation rates were determined and compared to microbial heterotrophic production in subsurface, meso- and bathypelagic Atlantic waters off the Galician coast (NW Iberian margin). DIC fixation rates were slightly higher than heterotrophic production

A systematic investigation of the preparation and properties of composite carbon molecular sieves containing inorganic oxides

Science.gov (United States)

Foley, Henry C.

1990-01-01

The objective of this research is to define the methodology for the preparation and characterization of new carbon-based molecular sieves with composite structures. Carbon molecular sieves have found increasing application in the field of separation and purification of gases. These materials are relatively easy to prepare and their surfaces can be modified to some extent. It is expected that by combining inorganic oxides with the carbonaceous structure one can begin to design composite materials with a wider range of possible chemical and physical properties. In this way, the IOM-CMS materials may confer distinct advantages over pure carbon molecular sieves, not just for separation, but also for catalysis. The most recent results in the design and characterization of these IOM-CMS materials are reviewed and summarized. Directions for further research are also presented.

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.)

The Bi{sup 3+} 6s and 6p electron binding energies in relation to the chemical environment of inorganic compounds

Energy Technology Data Exchange (ETDEWEB)

Awater, Roy H.P., E-mail: R.H.P.Awater@tudelft.nl; Dorenbos, Pieter

2017-04-15

This paper provides an overview and interpretation of the spectroscopic data of the Bi{sup 3+} activator ion in 117 different inorganic compounds. The energies of the metal-to-metal charge transfer and the interconfigurational transitions of Bi{sup 3+} were collected from the archival literature. Using these energies, in combination with the electron binding energies in the host conduction and valence band, the binding energies in the 6s ground state and 6p excited state were determined relative to the vacuum level. The locations of the Bi{sup 3+} energy levels within the forbidden gap of the host compound provides valuable insight in the physical properties of the Bi{sup 3+} activator ion in different compounds.

Steady-State Growth under Inorganic Carbon Limitation Conditions Increases Energy Consumption for Maintenance and Enhances Nitrous Oxide Production in Nitrosomonas europaea.

Science.gov (United States)

Mellbye, Brett L; Giguere, Andrew; Chaplen, Frank; Bottomley, Peter J; Sayavedra-Soto, Luis A

2016-06-01

Nitrosomonas europaea is a chemolithoautotrophic bacterium that oxidizes ammonia (NH3) to obtain energy for growth on carbon dioxide (CO2) and can also produce nitrous oxide (N2O), a greenhouse gas. We interrogated the growth, physiological, and transcriptome responses of N. europaea to conditions of replete (>5.2 mM) and limited inorganic carbon (IC) provided by either 1.0 mM or 0.2 mM sodium carbonate (Na2CO3) supplemented with atmospheric CO2 IC-limited cultures oxidized 25 to 58% of available NH3 to nitrite, depending on the dilution rate and Na2CO3 concentration. IC limitation resulted in a 2.3-fold increase in cellular maintenance energy requirements compared to those for NH3-limited cultures. Rates of N2O production increased 2.5- and 6.3-fold under the two IC-limited conditions, increasing the percentage of oxidized NH3-N that was transformed to N2O-N from 0.5% (replete) up to 4.4% (0.2 mM Na2CO3). Transcriptome analysis showed differential expression (P ≤ 0.05) of 488 genes (20% of inventory) between replete and IC-limited conditions, but few differences were detected between the two IC-limiting treatments. IC-limited conditions resulted in a decreased expression of ammonium/ammonia transporter and ammonia monooxygenase subunits and increased the expression of genes involved in C1 metabolism, including the genes for RuBisCO (cbb gene cluster), carbonic anhydrase, folate-linked metabolism of C1 moieties, and putative C salvage due to oxygenase activity of RuBisCO. Increased expression of nitrite reductase (gene cluster NE0924 to NE0927) correlated with increased production of N2O. Together, these data suggest that N. europaea adapts physiologically during IC-limited steady-state growth, which leads to the uncoupling of NH3 oxidation from growth and increased N2O production. Nitrification, the aerobic oxidation of ammonia to nitrate via nitrite, is an important process in the global nitrogen cycle. This process is generally dependent on ammonia

Carbon isotopic fractionation in live benthic foraminifera -comparison with inorganic precipitate studies

International Nuclear Information System (INIS)

Grossmann, E.L.

1984-01-01

Carbon and oxygen isotopic analyses have been performed on live-stained aragonitic and calcitic benthic foraminifera and dissolved inorganic carbon from the Southern California Borderland to examine carbon isotopic fractionation in foraminifera. Temperature, salinity and pH data have also been collected to permit accurate determination of the delta 13 C of bicarbonate ion and thus aragonite-HCO 3 - and calcite-HCO 3 - isotopic enrichment factors (epsilonsub(ar-b) and epsilonsub(cl-b), respectively). Only species which precipitate in 18 O equilibrium have been considered. epsilonsub (ar-b) values based on Hoeglundina elegans range from 1.9 per mille at 2.7 deg C to 1.1 per mille at 9.5 deg C. The temperature dependence of epsilonsub(ar-b) is considerably greater than the equilibrium equation would predict and may be due to a vital effect. The calcitic foraminifera Cassidulina tortuosa, Cassidulina braziliensis, and Cassidulina limbata, Bank and Terrace dwellers, have similar delta 13 C values and yield an average epsilonsub(cl-b) value of -0.2 +- 0.1 per mille between 8 deg and 10 deg C. Calcitic Uvigerina curticosta, Uvigerina peregrina, and megalospheric B, argentea, Slope and Basin dwellers, are -0.7 +- 0.1 per mille enriched relative to ambient bicarbonate for 3 to 9 deg C. (author)

Computer-Assisted Inverse Design of Inorganic Electrides

Directory of Open Access Journals (Sweden)

Yunwei Zhang

2017-02-01

Full Text Available Electrides are intrinsic electron-rich materials enabling applications as excellent electron emitters, superior catalysts, and strong reducing agents. There are a number of organic electrides; however, their instability at room temperature and sensitivity to moisture are bottlenecks for their practical uses. Known inorganic electrides are rare, but they appear to have greater thermal stability at ambient conditions and are thus better characterized for application. Here, we develop a computer-assisted inverse-design method for searching for a large variety of inorganic electrides unbiased by any known electride structures. It uses the intrinsic property of interstitial electron localization of electrides as the global variable function for swarm intelligence structure searches. We construct two rules of thumb on the design of inorganic electrides pointing to electron-rich ionic systems and low electronegativity of the cationic elements involved. By screening 99 such binary compounds through large-scale computer simulations, we identify 24 stable and 65 metastable new inorganic electrides that show distinct three-, two-, and zero-dimensional conductive properties, among which 18 are existing compounds that have not been pointed to as electrides. Our work reveals the rich abundance of inorganic electrides by providing 33 hitherto unexpected structure prototypes of electrides, of which 19 are not in the known structure databases.

Activating Student to Learn Chemistry using Chemmy Card 6-1 Game as an Instructional Medium in IUPAC Nomenclature of Inorganic Compounds

Science.gov (United States)

Lutfi, A.; Hidayah, R.

2018-01-01

The aim of this study is to know the effect of Internet-assisted Chemmy Card 6-1 game as an instructional medium in IUPAC Nomenclature of Inorganic Compounds material for X grade of senior high school on students’ activity, learning motivation, and learning outcome. The study was conducted at SMA Negeri Sidoarjo, Indonesia, in two different classes. The instruction was done based on the lesson plan made. The observation on students’ activity was conducted during the instruction with the game while test and questionnaire were given after the instruction. The result showed positive activities, which students listened to the teacher’s explanation, actively delivered questions, and enabled to solve problems in naming compounds. It was also effective to avoid the drowsiness. The result of students’ motivation of X MIPA 6 was 74.78% (good) while X MIPA 7 was 83.80% (very good). The pretest results of two classes showed that no students mastered but 100% students mastered and the increase of N-gain scores in two classes was categorized as high, ≥0,7, after the instruction. The result of this study showed that the use of Internet-assisted Chemmy Card 6-1 game in IUPAC nomenclature of inorganic compounds for X grade of senior high school could be pleasant for students to learn and effective in achieving the learning objective.

Adsorption of Volatile Organic Compounds from Aqueous Solution by Granular Activated Carbon in Batch System

International Nuclear Information System (INIS)

Zeinali, F.; Ghoreyshi, A. A.; Najafpour, G.

2011-01-01

Chlorinated hydrocarbons and aromatics are the major volatile organic compounds that contaminate the ground water and industrial waste waters. The best way to overcome this problem is to recover the dissolved compounds in water. In order to evaluate the potential ability of granular activated carbon for recovery of volatile organic compounds from water, the equilibrium adsorption was investigated. This study deals with the adsorption of dichloromethane as a typical chlorinated volatile organic compound and toluene as the representative of aromatic volatile organic compounds on a commercial granular activated carbon. The adsorption isotherms of these two volatile organic compounds on granular activated carbon were measured at three different temperatures, toluene at 293, 303 and 313 K and dichloromethane at 298, 303 and 313 K within their solubility concentration range in water. The maximum adsorption capacity of dichloromethane and toluene adsorption by granular activated carbon was 4 and 0.2 mol/Kg-1, respectively. The experimental data obtained were correlated with different adsorption isotherm models. The Langmuir model was well adapted to the description of dichloromethane adsorption on granular activated carbon at all three temperatures, while the adsorption of toluene on granular activated carbon was found to be well described by the Langmuir-BET hybrid model at all three temperatures. The heat of adsorption was also calculated based on the thermodynamic equation of Clausius Clapeyron, which indicates the adsorption process is endothermic for both compounds.

Stable carbon isotope signals in particulate organic and inorganic carbon of coccolithophores - A numerical model study for Emiliania huxleyi.

Science.gov (United States)

Holtz, Lena-Maria; Wolf-Gladrow, Dieter; Thoms, Silke

2017-05-07

A recent numerical cell model, which explains observed light and carbonate system effects on particulate organic and inorganic carbon (POC and PIC) production rates under the assumption of internal pH homeostasis, is extended for stable carbon isotopes ( 12 C, 13 C). Aim of the present study is to mechanistically understand the stable carbon isotopic fractionation signal (ε) in POC and PIC and furthermore the vital effect(s) included in measured ε PIC values. The virtual cell is divided into four compartments, for each of which the 12 C as well as the 13 C carbonate system kinetics are implemented. The compartments are connected to each other via trans-membrane fluxes. In contrast to existing carbon fractionation models, the presented model calculates the disequilibrium state for both carbonate systems and for each compartment. It furthermore calculates POC and PIC production rates as well as ε POC and ε PIC as a function of given light conditions and the compositions of the external carbonate system. Measured POC and PIC production rates as well as ε PIC values are reproduced well by the model (comparison with literature data). The observed light effect on ε POC (increase of ε POC with increasing light intensities), however, is not reproduced by the basic model set-up, which is solely based on RubisCO fractionation. When extending the latter set-up by assuming that biological fractionation includes further carbon fractionation steps besides the one of RubisCO, the observed light effect on ε POC is also reproduced. By means of the extended model version, four different vital effects that superimpose each other in a real cell can be detected. Finally, we discuss potential limitations of the ε PIC proxy. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

NARCIS (Netherlands)

Krumins, V.; Gehlen, M.; Arndt, S.; Van Cappellen, P.; Regnier, P.

2013-01-01

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,

Bio remediation of inorganic contaminants; Biotratamiento de contaminantes de origen inorganico

Energy Technology Data Exchange (ETDEWEB)

Algucial, F J; Merino, Y [Centro Nacional de Investigaciones Metalurgicas. CENIM. Madrid (Spain)

1999-12-31

Bio remediation is usually associated with the remediation of organic contaminants. However, there is an increasing amount of information on the application of biological systems to bio remediation of soils, sediments and water contaminated with inorganic compounds which includes metals, radionuclides and anions (e.g. nitrates and cyanides). These compounds can be toxic both to humans and to the organisms used to remediate these toxic components. In contrast to organic compounds, most inorganic contaminants cannot be degrades, but must be remediated by altering their transport properties. Immobilization, mobilization or transformation of inorganic contaminants via bioaccumulation, bi sorption, oxidation and reduction, methylation, demethylation, complexation, ligand degradation, and phytoremediation are some of the different processes applied in this type of byoremediation. This paper describes these processes. (Author) 60 refs.

Improved quality control of carbon-14 labelled compounds

International Nuclear Information System (INIS)

Leonhardt, J.W.; Fuchs, P.; Standtke, K.

1997-01-01

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 14 C-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

Irreversible adsorption of phenolic compounds by activated carbons

Energy Technology Data Exchange (ETDEWEB)

Grant, T.M.; King, C.J.

1988-12-01

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.

Irreversible adsorption of phenolic compounds by activated carbons

International Nuclear Information System (INIS)

Grant, T.M.; King, C.J.

1988-12-01

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

Study on radiation-induced polymerization of vinyl monomers adsorbed on inorganic substances. II. Radiation-induced polymerization of methyl methacrylate adsorbed on several inorganic substances

International Nuclear Information System (INIS)

Fukano, K.; Kageyama, E.

1975-01-01

The radiation-induced polymerization of methyl methacrylate (MMA) adsorbed on such inorganic substances as silica gel, white carbon, silicic acid anhydride, zeolite, and activated alumina was carried out to compare with the case of styrene. The rate of radiation-induced polymerization adsorbed on inorganic substances was high compared with that of radiation-induced bulk state polymerization, as was the case with styrene. Inorganic substrates which contain aluminum as a component element are more likely to be grafted than those which consist of SiO 2 alone, as with styrene. The molecular weight distribution of unextractable polymer and extractable polymer differs, depending on the type of inorganic substance. Experiments by a preirradiation method were carried out in case of silica gel, white carbon, and silicic acid anhydride. GPC spectra of the polymer obtained were different from those of polymer formed by the simultaneous irradiation method. It appears that all the unextractable polymer is grafted to the inorganic surface with chemical bond

Concentrations of inorganic elements in biomass fuels and recovery in the different ash fractions

NARCIS (Netherlands)

Obernberger, I.; Biedermann, F.; Widmann, W.; Riedl, R.

1997-01-01

Inorganic elements and compounds in biomass fuels influence the combustion process and the composition of the ashes produced. Consequently, knowledge about the material fluxes of inorganic elements and compounds during biomass combustion for different kinds of biofuels and their influencing

Carbon isotopes of dissolved inorganic carbon reflect utilization of different carbon sources by microbial communities in two limestone aquifer assemblages

Directory of Open Access Journals (Sweden)

M. E. Nowak

2017-08-01

Full Text Available Isotopes of dissolved inorganic carbon (DIC are used to indicate both transit times and biogeochemical evolution of groundwaters. These signals can be complicated in carbonate aquifers, as both abiotic (i.e., carbonate equilibria and biotic factors influence the δ13C and 14C of DIC. We applied a novel graphical method for tracking changes in the δ13C and 14C of DIC in two distinct aquifer complexes identified in the Hainich Critical Zone Exploratory (CZE, a platform to study how water transport links surface and shallow groundwaters in limestone and marlstone rocks in central Germany. For more quantitative estimates of contributions of different biotic and abiotic carbon sources to the DIC pool, we used the NETPATH geochemical modeling program, which accounts for changes in dissolved ions in addition to C isotopes. Although water residence times in the Hainich CZE aquifers based on hydrogeology are relatively short (years or less, DIC isotopes in the shallow, mostly anoxic, aquifer assemblage (HTU were depleted in 14C compared to a deeper, oxic, aquifer complex (HTL. Carbon isotopes and chemical changes in the deeper HTL wells could be explained by interaction of recharge waters equilibrated with post-bomb 14C sources with carbonates. However, oxygen depletion and δ13C and 14C values of DIC below those expected from the processes of carbonate equilibrium alone indicate considerably different biogeochemical evolution of waters in the upper aquifer assemblage (HTU wells. Changes in 14C and 13C in the upper aquifer complexes result from a number of biotic and abiotic processes, including oxidation of 14C-depleted OM derived from recycled microbial carbon and sedimentary organic matter as well as water–rock interactions. The microbial pathways inferred from DIC isotope shifts and changes in water chemistry in the HTU wells were supported by comparison with in situ microbial community structure based on 16S rRNA analyses. Our findings

Bioinformatic analysis of the distribution of inorganic carbon transporters and prospective targets for bioengineering to increase Ci uptake by cyanobacteria.

Science.gov (United States)

Gaudana, Sandeep B; Zarzycki, Jan; Moparthi, Vamsi K; Kerfeld, Cheryl A

2015-10-01

Cyanobacteria have evolved a carbon-concentrating mechanism (CCM) which has enabled them to inhabit diverse environments encompassing a range of inorganic carbon (Ci: [Formula: see text] and CO2) concentrations. Several uptake systems facilitate inorganic carbon accumulation in the cell, which can in turn be fixed by ribulose 1,5-bisphosphate carboxylase/oxygenase. Here we survey the distribution of genes encoding known Ci uptake systems in cyanobacterial genomes and, using a pfam- and gene context-based approach, identify in the marine (alpha) cyanobacteria a heretofore unrecognized number of putative counterparts to the well-known Ci transporters of beta cyanobacteria. In addition, our analysis shows that there is a huge repertoire of transport systems in cyanobacteria of unknown function, many with homology to characterized Ci transporters. These can be viewed as prospective targets for conversion into ancillary Ci transporters through bioengineering. Increasing intracellular Ci concentration coupled with efforts to increase carbon fixation will be beneficial for the downstream conversion of fixed carbon into value-added products including biofuels. In addition to CCM transporter homologs, we also survey the occurrence of rhodopsin homologs in cyanobacteria, including bacteriorhodopsin, a class of retinal-binding, light-activated proton pumps. Because they are light driven and because of the apparent ease of altering their ion selectivity, we use this as an example of re-purposing an endogenous transporter for the augmentation of Ci uptake by cyanobacteria and potentially chloroplasts.

Sorption mechanisms of perfluorinated compounds on carbon nanotubes

International Nuclear Information System (INIS)

Deng Shubo; Zhang Qiaoying; Nie Yao; Wei Haoran; Wang Bin; Huang Jun; Yu Gang; Xing Baoshan

2012-01-01

Sorption of perfluorinated compounds (PFCs) on carbon nanotubes (CNTs) is critical for understanding their subsequent transport and fate in aqueous environments, but the sorption mechanisms remain largely unknown. In this study, the sorption of six PFCs on CNTs increased with increasing C-F chain length when they had a same functional group, and the CNTs with hydroxyl and carboxyl groups had much lower adsorbed amount than the pristine CNTs, indicating that hydrophobic interaction dominated the sorption of PFCs on the CNTs. Electrostatic repulsion suppressed the sorption of PFCs on the CNTs, resulting in the lower sorption with increasing pH. Hydrogen bonding interaction was negligible. The hydrophobic C-F chains can be closely adsorbed on the CNTs surface in parallel to the axis or along the curvature, making it impossible to form micelles on the CNT surface, leading to the lower sorption than other adsorbents. Highlights: ► Sorption capacities of PFOA on different CNTs are less than that on activated carbon and resins. ► Hydrophobic interaction is principally involved in the sorption of PFCs on CNTs. ► Electrostatic repulsion suppresses the sorption of PFCs on CNTs. - Hydrophobic interaction dominated the sorption of perfluorinated compounds on carbon nanotubes, while electrostatic repulsion suppressed their sorption.

Inorganic carbon fluxes on the Mackenzie Shelf of the Beaufort Sea

Science.gov (United States)

Mol, Jacoba; Thomas, Helmuth; Myers, Paul G.; Hu, Xianmin; Mucci, Alfonso

2018-02-01

The Mackenzie Shelf in the southeastern Beaufort Sea is a region that has experienced large changes in the past several decades as warming, sea-ice loss, and increased river discharge have altered carbon cycling. Upwelling and downwelling events are common on the shelf, caused by strong, fluctuating along-shore winds, resulting in cross-shelf Ekman transport, and an alternating estuarine and anti-estuarine circulation. Downwelling carries dissolved inorganic carbon (DIC) and other remineralization products off the shelf and into the deep basin for possible long-term storage in the world's oceans. Upwelling carries DIC and nutrient-rich waters from the Pacific-origin upper halocline layer (UHL) onto the shelf. Profiles of DIC and total alkalinity (TA) taken in August and September of 2014 are used to investigate the cycling of carbon on the Mackenzie Shelf. The along-shore transport of water and the cross-shelf transport of DIC are quantified using velocity field output from a simulation of the Arctic and Northern Hemisphere Atlantic (ANHA4) configuration of the Nucleus of European Modelling of the Ocean (NEMO) framework. A strong upwelling event prior to sampling on the Mackenzie Shelf took place, bringing CO2-rich (elevated pCO2) water from the UHL onto the shelf bottom. The maximum on-shelf DIC flux was estimated at 16.9×103 mol C d-1 m-2 during the event. The maximum on-shelf transport of DIC through the upwelling event was found to be 65±15×10-3 Tg C d-1. TA and the oxygen isotope ratio of water (δ18O-H2O) are used to examine water-mass distributions in the study area and to investigate the influence of Pacific Water, Mackenzie River freshwater, and sea-ice melt on carbon dynamics and air-sea fluxes of carbon dioxide (CO2) in the surface mixed layer. Understanding carbon transfer in this seasonally dynamic environment is key to quantify the importance of Arctic shelf regions to the global carbon cycle and provide a basis for understanding how it will

Inorganic carbon fluxes on the Mackenzie Shelf of the Beaufort Sea

Directory of Open Access Journals (Sweden)

J. Mol

2018-02-01

Full Text Available The Mackenzie Shelf in the southeastern Beaufort Sea is a region that has experienced large changes in the past several decades as warming, sea-ice loss, and increased river discharge have altered carbon cycling. Upwelling and downwelling events are common on the shelf, caused by strong, fluctuating along-shore winds, resulting in cross-shelf Ekman transport, and an alternating estuarine and anti-estuarine circulation. Downwelling carries dissolved inorganic carbon (DIC and other remineralization products off the shelf and into the deep basin for possible long-term storage in the world's oceans. Upwelling carries DIC and nutrient-rich waters from the Pacific-origin upper halocline layer (UHL onto the shelf. Profiles of DIC and total alkalinity (TA taken in August and September of 2014 are used to investigate the cycling of carbon on the Mackenzie Shelf. The along-shore transport of water and the cross-shelf transport of DIC are quantified using velocity field output from a simulation of the Arctic and Northern Hemisphere Atlantic (ANHA4 configuration of the Nucleus of European Modelling of the Ocean (NEMO framework. A strong upwelling event prior to sampling on the Mackenzie Shelf took place, bringing CO2-rich (elevated pCO2 water from the UHL onto the shelf bottom. The maximum on-shelf DIC flux was estimated at 16.9×103 mol C d−1 m−2 during the event. The maximum on-shelf transport of DIC through the upwelling event was found to be 65±15×10−3 Tg C d−1. TA and the oxygen isotope ratio of water (δ18O-H2O are used to examine water-mass distributions in the study area and to investigate the influence of Pacific Water, Mackenzie River freshwater, and sea-ice melt on carbon dynamics and air–sea fluxes of carbon dioxide (CO2 in the surface mixed layer. Understanding carbon transfer in this seasonally dynamic environment is key to quantify the importance of Arctic shelf regions to the global carbon cycle and provide a basis

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 %.

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.)

Carbon and nitrogen accumulation and fluxes on Landscape Evolution Observatory (LEO) slopes

Science.gov (United States)

Dontsova, K.; Volk, M.; Webb, C.; Hunt, E.; Tfaily, M. M.; Van Haren, J. L. M.; Sengupta, A.; Chorover, J.; Troch, P.; Ruiz, J.

2017-12-01

Carbon accumulation on the landscapes in organic and inorganic forms is an important sink of CO2 from the atmosphere. Formation and preservation of organic compounds is accompanied by N fixation from the atmosphere and cycling in the soil. Model slopes of Landscape Evolution Observatory present unique opportunity to examine carbon and nitrogen buildup on the landscapes during soil formation processes, such as weathering of primary minerals and microbial activity, due to low original levels of C and N, tight control over environmental conditions, and high spatial and temporal density of measurements. This presents results of inorganic and organic C and N measurements in the cores collected in LEO slopes after several years of exposure to the rainfall, as well as soil solution measurements collected through 496 samplers on each of three model slopes and in seepage. We observed significant spatially distributed accumulation of both C (organic and inorganic) and N in soil profiles. We also observed differences in the composition of organic compounds in the solid and solution phases depending on location on the slope indicating formation of heterogeneity as soils develop. This works indicates potential of physical models to help understand accumulation and fluxes of C and N on natural landscapes.

Effect of changes in water salinity on ammonium, calcium, dissolved inorganic carbon and influence on water/sediment dynamics

Science.gov (United States)

López, P.

2003-04-01

The effect of a sudden increase in salinity from 10 to 37 in porewater concentration and the benthic fluxes of ammonium, calcium and dissolved inorganic carbon were studied in sediments of a small coastal lagoon, the Albufera d'Es Grau (Minorca Island, Spain). The temporal effects of the changes in salinity were examined over 17 days using a single diffusion-reaction model and a mass-balance approach. After the salinity change, NH 4+-flux to the water and Ca-flux toward sediments increased (NH 4+-flux: 5000-3000 μmol m -2 d -1 in seawater and 600/250 μmol m -2 d -1 in brackish water; Ca-flux: -40/-76 meq m -2 d -1 at S=37 and -13/-10 meq m -2 d -1 at S=10); however, later NH 4+-flux decreased in seawater, reaching values lower than in brackish water. In contrast, Ca-flux presented similar values in both conditions. The fluxes of dissolved inorganic carbon, which were constant at S=10 (55/45 mmol m -2 d -1), increased during the experiment at S=37 (from ˜30 mmol m -2 d -1 immediately after salinity increase to ˜60 mmol m -2 d -1 after 17 days). In brackish conditions, NH 4+ and Ca 2+ fluxes were consistent with a single diffusion-reaction model that assumes a zero-order reaction for NH 4+ production and a first-order reaction for Ca 2+ production. In seawater, this model explained the Ca-flux observed, but did not account for the high initial flux of NH 4+. The mass balance for 17 days indicated a higher retention of NH 4+ in porewater in the littoral station in seawater conditions (9.5 mmol m -2 at S=37 and 1.6 mmol m -2 at S=10) and a significant reduction in the water consumption at both sites (5 mmol m -2 at S=37; 35/23 mmol m -2 at S=10). In contrast, accumulation of dissolved inorganic carbon in porewater was lower in seawater incubations (-10/-1 meq m -2 at S=37; 50/90 meq m -2 at S=10) and was linked to a higher efflux of CO 2 to the atmosphere, because of calcium carbonate precipitation in water (675/500 meq m -2). These results indicate that increased

Recent developments in inorganically filled carbon nanotubes: successes and challenges

Directory of Open Access Journals (Sweden)

Ujjal K Gautam, Pedro M F J Costa, Yoshio Bando, Xiaosheng Fang, Liang Li, Masataka Imura and Dmitri Golberg

2010-01-01

Full Text Available Carbon nanotubes (CNTs are a unique class of nanomaterials that can be imagined as rolled graphene sheets. The inner hollow of a CNT provides an extremely small, one-dimensional space for storage of materials. In the last decade, enormous effort has been spent to produce filled CNTs that combine the properties of both the host CNT and the guest filling material. CNTs filled with various inorganic materials such as metals, alloys, semiconductors and insulators have been obtained using different synthesis approaches including capillary filling and chemical vapor deposition. Recently, several potential applications have emerged for these materials, such as the measurement of temperature at the nanoscale, nano-spot welding, and the storage and delivery of extremely small quantities of materials. A clear distinction between this class of materials and other nanostructures is the existence of an enormous interfacial area between the CNT and the filling matter. Theoretical investigations have shown that the lattice mismatch and strong exchange interaction of CNTs with the guest material across the interface should result in reordering of the guest crystal structure and passivation of the surface dangling bonds and thus yielding new and interesting physical properties. Despite preliminary successes, there remain many challenges in realizing applications of CNTs filled with inorganic materials, such as a comprehensive understanding of their growth and physical properties and control of their structural parameters. In this article, we overview research on filled CNT nanomaterials with special emphasis on recent progress and key achievements. We also discuss the future scope and the key challenges emerging out of a decade of intensive research on these fascinating materials.

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

International Nuclear Information System (INIS)

Swanson, J.R.

1980-01-01

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

Reaction of phosphorus ylides with carbonyl compounds in supercritical carbon dioxide

International Nuclear Information System (INIS)

Jeong, Kyung Il; Kim, Hak Do; Shim, Jae Jin; Ra, Choon Sup

2004-01-01

The condensation reaction of (benzylene)triphenylphosphoranes with carbonyl compounds in supercritical carbon dioxide was examined. Reactions of (benzylene)phosphoranes (ca. 1 mmol) with several benzaldehydes in a supercritical carbon dioxide (80 .deg. C, 2,000 psi) containing THF entrainer (5%) in a 24 mL reactor proceed smoothly to yield olefination products in fairly good to excellent yields but slower, compared to reactions in a conventional THF solvent. Generally, phosphoranes that are not substituted with a nitro group show more (Z)-selective reactions with aromatic aldehydes under scCO 2 condition than in THF. The reaction of (benzylene)triphenylphosphosphoranes with 4-t-butylcyclohexanone gave the corresponding olefin compounds with a low conversion under both the supercritical carbon dioxide and the organic THF solvent. Our preliminary study showed the Wittig reaction carries out smoothly in supercritical carbon dioxide medium and also a possible tunability of this reaction pathway by adding a entrainer. The results would be useful for devising a novel process for the environmentally friendly Wittig reaction

Inter-annual Variability in Global Suspended Particulate Inorganic Carbon Inventory Using Space-based Measurements

Science.gov (United States)

Hopkins, J.; Balch, W. M.; Henson, S.; Poulton, A. J.; Drapeau, D.; Bowler, B.; Lubelczyk, L.

2016-02-01

Coccolithophores, the single celled phytoplankton that produce an outer covering of calcium carbonate coccoliths, are considered to be the greatest contributors to the global oceanic particulate inorganic carbon (PIC) pool. The reflective coccoliths scatter light back out from the ocean surface, enabling PIC concentration to be quantitatively estimated from ocean color satellites. Here we use datasets of AQUA MODIS PIC concentration from 2003-2014 (using the recently-revised PIC algorithm), as well as statistics on coccolithophore vertical distribution derived from cruises throughout the world ocean, to estimate the average global (surface and integrated) PIC standing stock and its associated inter-annual variability. In addition, we divide the global ocean into Longhurst biogeochemical provinces, update the PIC biomass statistics and identify those regions that have the greatest inter-annual variability and thus may exert the greatest influence on global PIC standing stock and the alkalinity pump.

Radiocarbon and stable-isotope geochemistry of organic and inorganic carbon in Lake Superior

Science.gov (United States)

Zigah, Prosper K.; Minor, Elizabeth C.; Werne, Josef P.

2012-03-01

We present a lake-wide investigation of Lake Superior carbon and organic matter biogeochemistry using radiocarbon, stable isotope, and carbon concentrations. Dissolved inorganic carbon (DIC) abundance in the lake was 121-122 Tg C, with offshore concentration andδ13C values being laterally homogenous and tightly coupled to the physical and thermal regime and biochemical processes. Offshore Δ14C of DIC (50-65‰) exhibited lateral homogeneity and was more 14C enriched than co-occurring atmospheric CO2 (˜38‰); nearshore Δ14C of DIC (36-38‰) was similar to atmospheric CO2. Dissolved organic carbon (DOC) abundance was 14.2-16.4 Tg C. DOC's concentration and δ13C were homogenous in June (mixed lake), but varied laterally during August (stratification) possibly due to spatial differences in lake productivity. Throughout sampling, DOC had modern radiocarbon values (14-58‰) indicating a semilabile nature with a turnover time of ≤60 years. Lake particulate organic carbon (POC, 0.9-1.3 Tg C) was consistently 13C depleted relative to DOC. The δ15N of epilimnetic particulate organic nitrogen shifted to more negative values during stratification possibly indicating greater use of nitrate (rather than ammonium) by phytoplankton in August. POC's radiocarbon was spatially heterogeneous (Δ14C range: 58‰ to -303‰), and generally 14C depleted relative to DOC and DIC. POC 14C depletion could not be accounted for by black carbon in the lake but, because of its spatial and temporal distribution, is attributed to sediment resuspension. The presence of old POC within the epilimnion of the open lake indicates possible benthic-pelagic coupling in the lake's organic carbon cycle; the ultimate fate of this old POC bears further investigation.

Sample distillation/graphitization system for carbon pool analysis by accelerator mass spectrometry (AMS)

International Nuclear Information System (INIS)

Pohlman, J.W.; Knies, D.L.; Grabowski, K.S.; DeTurck, T.M.; Treacy, D.J.; Coffin, R.B.

2000-01-01

A facility at the Naval Research Laboratory (NRL), Washington, DC, has been developed to extract, trap, cryogenically distill and graphitize carbon from a suite of organic and inorganic carbon pools for analysis by accelerator mass spectrometry (AMS). The system was developed to investigate carbon pools associated with the formation and stability of methane hydrates. However, since the carbon compounds found in hydrate fields are ubiquitous in aquatic ecosystems, this apparatus is applicable to a number of oceanographic and environmental sample types. Targeted pools are dissolved methane, dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), solid organic matrices (e.g., seston, tissue and sediments), biomarkers and short chained (C 1 -C 5 ) hydrocarbons from methane hydrates. In most instances, the extraction, distillation and graphitization events are continuous within the system, thus, minimizing the possibility of fractionation or contamination during sample processing. A variety of methods are employed to extract carbon compounds and convert them to CO 2 for graphitization. Dissolved methane and DIC from the same sample are sparged and cryogenically separated before the methane is oxidized in a high temperature oxygen stream. DOC is oxidized to CO 2 by 1200 W ultraviolet photo-oxidation lamp, and solids oxidized in sealed, evacuated tubes. Hydrocarbons liberated from the disassociation of gas hydrates are cryogenically separated with a cryogenic temperature control unit, and biomarkers separated and concentrated by preparative capillary gas chromatography (PCGC). With this system, up to 20 samples, standards or blanks can be processed per day

The metabolism and dosimetry of carbon-14 labelled compounds

International Nuclear Information System (INIS)

Crawley, F.E.H.

1977-01-01

The number of compounds labelled at high specific activity with carbon-14 has greatly increased over the last few years. There are limited biological data available to enable an assessment of the internal radiation dose and to identify the critical tissues after an intake of such compounds. The ICRP consider two Model Systems for deriving dose. Both Models assume a total elimination of the carbon-14 in the breath and only bone or whole body as critical tissues and are not representative of the majority of the compounds now available. A research programme has been established to study the rate of excretion and tissue distribution of selected carbon-14 labelled compounds in the rat after intravenous injection, pulmonary and gastric intubation and skin absorption. These metabolic data have been used to calculate the committed dose equivalent and maximum permissible annual intake (MPAI) for various tissues in man on the assumption that the experimental data obtained in the rat are true for man. To date potassium 14 C-cyanide and 14 C-methanol have been studied. The values for the MPAI's derived from the doses to individual tissues are more restrictive than values calculated from the whole body doses. The MPAI calculated from excretion data in terms of whole body dose is 31 mCi for 14 C-cyanide and 25 mCi for 14 C-methanol. However, the critical tissue for 14 C-cyanide is the stomach with an MPAI of 1.5 mCi based on a dose of 10.7 rem mCi -1 . This was an order of magnitude greater than the dose to any other region of the GI tract and 5 times that to the testis. The critical organs for 14 C-methanol are the testis (MPAI 2.5 mCi) for males and the ovaries (MPAI 6.2 mCi) for females

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)

Queiroz, Carlos Alberto da Silva

1996-05-01

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)

Inorganic and organic radiation chemistry: state and problems

International Nuclear Information System (INIS)

Kalyazin, E.P.; Bugaenko, L.T.

1990-01-01

Radiation inorganic and organic chemistry is presented on the basis of the general scheme and classification of radiolysis products and elementary processes, by which evolution of radiation-affected substances up to the final radiolysis products takes place. The evolution is traced for the representatives of inorganic and organic compounds. The contribution of radiation inorganic and organic chemistry to radiation technology, radiation materials technology, radiation ecology and medicine, is shown. Tendencies in the development of radiation chemistry and prediction of its certain directions are considered

Simulated Carbon Cycling in a Model Microbial Mat.

Science.gov (United States)

Decker, K. L.; Potter, C. S.

2006-12-01

We present here the novel addition of detailed organic carbon cycling to our model of a hypersaline microbial mat ecosystem. This ecosystem model, MBGC (Microbial BioGeoChemistry), simulates carbon fixation through oxygenic and anoxygenic photosynthesis, and the release of C and electrons for microbial heterotrophs via cyanobacterial exudates and also via a pool of dead cells. Previously in MBGC, the organic portion of the carbon cycle was simplified into a black-box rate of accumulation of simple and complex organic compounds based on photosynthesis and mortality rates. We will discuss the novel inclusion of fermentation as a source of carbon and electrons for use in methanogenesis and sulfate reduction, and the influence of photorespiration on labile carbon exudation rates in cyanobacteria. We will also discuss the modeling of decomposition of dead cells and the ultimate release of inorganic carbon. The detailed modeling of organic carbon cycling is important to the accurate representation of inorganic carbon flux through the mat, as well as to accurate representation of growth models of the heterotrophs under different environmental conditions. Because the model ecosystem is an analog of ancient microbial mats that had huge impacts on the atmosphere of early earth, this MBGC can be useful as a biological component to either early earth models or models of other planets that potentially harbor life.

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.

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

Inorganic ion-exchangers for the treatment and disposal of industrial effluents

International Nuclear Information System (INIS)

Hasany, S.M.

2000-01-01

Ion-exchangers can be broadly classified into organic and inorganic ion-exchangers. Inorganic ion-exchangers are stable at high temperatures and radiation dosage, resistant towards oxidizing agents and organic solvents. They are cheap and easy to prepare. Inorganic ion-exchangers, due to their superiority over organic ion-exchangers, have been extensively used for a wide variety of applications including treatment and management of industrial effluents. The criteria governing the division into essential and toxic elements for animal life have been described. The occupational sources of toxic elements and their compounds in the environment have been identified and their tolerance limits prescribed in air, water and food are given. The toxicity and adverse effects of harmful elements and their hazardous compounds are mentioned. Factors influencing sorption of trace elements onto inorganic ion-exchangers are highlighted. Examples of inorganic ion-exchangers are cited where they can be utilized for the treatment of industrial effluents before their safe discharge into waterways and biosphere. (author)

Electrochemical determination of inorganic mercury and arsenic--A review.

Science.gov (United States)

Zaib, Maria; Athar, Muhammad Makshoof; Saeed, Asma; Farooq, Umar

2015-12-15

Inorganic mercury and arsenic encompasses a term which includes As(III), As(V) and Hg(II) species. These metal ions have been extensively studied due to their toxicity related issues. Different analytical methods are used to monitor inorganic mercury and arsenic in a variety of samples at trace level. The present study reviews various analytical techniques available for detection of inorganic mercury and arsenic with particular emphasis on electrochemical methods especially stripping voltammetry. A detailed critical evaluation of methods, advantages of electrochemical methods over other analytical methods, and various electrode materials available for mercury and arsenic analysis is presented in this review study. Modified carbon paste electrode provides better determination due to better deposition with linear and improved response under studied set of conditions. Biological materials may be the potent and economical alternative as compared to macro-electrodes and chemically modified carbon paste electrodes in stripping analysis of inorganic mercury and arsenic. Copyright © 2015 Elsevier B.V. All rights reserved.

Measured and modeled humidification factors of fresh smoke particles from biomass burning: role of inorganic constituents

Directory of Open Access Journals (Sweden)

J. L. Hand

2010-07-01

Full Text Available During the 2006 FLAME study (Fire Laboratory at Missoula Experiment, laboratory burns of biomass fuels were performed to investigate the physico-chemical, optical, and hygroscopic properties of fresh biomass smoke. As part of the experiment, two nephelometers simultaneously measured dry and humidified light scattering coefficients (b_sp(dry and b_sp(RH, respectively in order to explore the role of relative humidity (RH on the optical properties of biomass smoke aerosols. Results from burns of several biomass fuels from the west and southeast United States showed large variability in the humidification factor (f(RH=b_sp(RH/b_sp(dry. Values of f(RH at RH=80–85% ranged from 0.99 to 1.81 depending on fuel type. We incorporated measured chemical composition and size distribution data to model the smoke hygroscopic growth to investigate the role of inorganic compounds on water uptake for these aerosols. By assuming only inorganic constituents were hygroscopic, we were able to model the water uptake within experimental uncertainty, suggesting that inorganic species were responsible for most of the hygroscopic growth. In addition, humidification factors at 80–85% RH increased for smoke with increasing inorganic salt to carbon ratios. Particle morphology as observed from scanning electron microscopy revealed that samples of hygroscopic particles contained soot chains either internally or externally mixed with inorganic potassium salts, while samples of weak to non-hygroscopic particles were dominated by soot and organic constituents. This study provides further understanding of the compounds responsible for water uptake by young biomass smoke, and is important for accurately assessing the role of smoke in climate change studies and visibility regulatory efforts.

Inorganic Carbon Source for Photosynthesis in the Seagrass Thalassia hemprichii (Ehrenb.) Aschers.

Science.gov (United States)

Abel, K M

1984-11-01

Photosynthetic carbon uptake of the tropical seagrass Thalassia hemprichii (Ehrenb.) Aschers was studied by several methods. Photosynthesis in buffered seawater in media in the range of pH 6 to pH 9 showed an exponentially increasing rate with decreasing pH, thus indicating that free CO(2) was a photosynthetic substrate. However, these experiments were unable to determine whether photosynthesis at alkaline pH also contained some component due to HCO(3) (-) uptake. This aspect was further investigated by studying photosynthetic rates in a number of media of varying pH (7.8-8.61) and total inorganic carbon (0.75-13.17 millimolar). In these media, photosynthetic rate was correlated with free CO(2) concentration and was independent of the HCO(3) (-) concentration in the medium. Short time-course experiments were conducted during equilibration of free CO(2) and HCO(3) (-) after injection of (14)C labeled solution at acid or alkaline pH. High initial photosynthetic rates were observed when acidic solutions (largely free CO(2)) were used but not with alkaline solutions. The concentration of free CO(2) was found to be a limiting factor for photosynthesis in this plant.

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

Science.gov (United States)

Porowska, Dorota

2015-05-01

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(13)CDIC) 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(13)CDIC 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 Otwock were always one to two orders of magnitude above the atmospheric P CO2, and thus CO2 escaped directly into the vadose zone. Copyright © 2015 Elsevier Ltd. All rights reserved.

Crystal structure of caesium hydrogen (L)-aspartate and an overview of crystalline compounds of aspartic acid with inorganic constituents

Energy Technology Data Exchange (ETDEWEB)

Fleck, M. [Universitaet Wien (Austria). Institut fuer Mineralogie und Kristallographie; Emmerich, R.; Bohaty, L. [Universitaet zu Koeln (Austria). Institut fuer Kristallographie

2010-08-15

The crystal structure of the new polar compound caesium hydrogen (L)-aspartate, Cs(C{sub 4}H{sub 6}NO{sub 4}), (abbreviated: Cs(L -AspH)) was determined from single crystal X-ray diffraction data; it comprises two crystallographically different L -AspH anions that are connected via caesium cations to form a three dimensional framework. The Cs ions are irregularly sevenfold[Cs1O{sub 7}] respectively eightfold[Cs2O{sub 8}] coordinated to all {alpha}- and {beta}- carboxylate oxygen atoms. Cs(L -AspH) represents a novel structure type of its own, as do most compounds of (L)-aspartic acid with inorganic constituents. A brief summary of such structurally known aspartates is given. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

On-line technique for preparingand measuring stable carbon isotopeof total dissolved inorganic carbonin water samples ( d13CTDIC

Directory of Open Access Journals (Sweden)

S. Inguaggiato

2005-06-01

Full Text Available A fast and completely automated procedure is proposed for the preparation and determination of d13C of total inorganic carbon dissolved in water ( d13CTDIC. This method is based on the acidification of water samples transforming the whole dissolved inorganic carbon species into CO2. Water samples are directly injected by syringe into 5.9 ml vials with screw caps which have a pierciable rubber septum. An Analytical Precision «Carbonate Prep System» was used both to flush pure helium into the vials and to automatically dispense a fixed amount of H3PO4. Full-equilibrium conditions between produced CO2 and water are reached at a temperature of 70°C (± 0.1°C in less than 24 h. Carbon isotope ratios (13C/ 12C were measured on an AP 2003 continuous flow mass spectrometer, connected on-line with the injection system. The precision and reproducibility of the proposed method was tested both on aqueous standard solutions prepared using Na2CO3 with d13C=-10.78 per mil versus PDB (1 s= 0.08, n = 11, and at five different concentrations (2, 3, 4, 5 and 20 mmol/l and on more than thirty natural samples. Mean d13CTDIC on standard solution samples is ?10.89 < per mil versus PDB (1 s= 0.18, n = 50, thus revealing both a good analytical precision and reproducibility. A comparison between average d13CTDIC values on a quadruplicate set of natural samples and those obtained following the chemical and physical stripping method highlights a good agreement between the two analytical methods.

Dynamics of organic and inorganic carbon in surface sediments of the Yellow River Estuary

Science.gov (United States)

Yu, Z.; Wang, X.; Liu, X.; Zhang, E.; Hang, F.

2017-12-01

Estuarine sediment is an important carbon reservoir thus may play an important role in the global carbon cycle. However, little is known on the dynamics of organic carbon (OC) and inorganic carbon (IC) in the surface sediment of the Yellow River Estuary, a large estuary in northern China. In this study, we applied element analyses and isotopic approach to study spatial distribution and sources of OC and IC in the Yellow River Estuary. We found that TIC concentration (6.3-20.1 g kg-1) was much higher than TOC (0.2-4.4 g kg-1) in the surface sediment. There showed a large spatial variability in TOC and TIC and their stable isotopes. Both TOC and TIC were higher to the north (2.6 and 14.5 g kg-1) than to the south (1.6 and 12.2 g kg-1), except in the southern bay where TOC and TIC reached 2.7 and 15.4 g kg-1, respectively. Generally, TOC and TIC in our study area was mainly autochthonous. The lower TOC values in the south section were due to relatively higher kinetic energy level whereas the higher values in the bay was attributable to terrigenous matters accumulation and lower kinetic energy level. However, the southern bay revealed the most negative δ13Corg and δ13Ccarb, suggesting that there might exist some transfer of OC to IC in the section. Our study points out that the dynamics of sedimentary carbon in the Yellow River Estuary is influenced by multiple and complex processes, and highlights the importance of carbonate in carbon sequstration.

Interactions between radionuclides and organic colloids. Structure and reactivity of humic compounds

International Nuclear Information System (INIS)

Plancque, G.

2001-09-01

Humic compounds are the main organic colloids present in natural waters. These compounds can significantly modify the speciation of metals and control their properties, like migration, toxicity or bio-availability. It is thus important to study their speciation in conditions representative to those encountered in the natural environment. The aim of this work is to analyze the reactivity of these humic compounds. Two spectroscopic techniques have been used: the time-resolution laser spectro-fluorimetry, limited to the study of fluorescent elements, and the electro-spray source mass spectroscopy which requires the development of specific protocols for all elements of the periodic classification system. Europium, a fluorescent element analogue to trivalent actinides, has been chosen as test-metal for the intercomparison of both spectroscopic techniques. The first technique has permitted to determine the inorganic and organic speciation (spectra and lifetime of europium hydroxides and carbonates, and constants of interaction with humic acids, respectively). The limitations of this technique in the study of inorganic speciation has been evidenced. Humic compounds have a badly defined structure. The use of high-resolution mass spectroscopy has permitted to propose in a direct and experimental way, a molecular structure of aquatic fulvic acids in agreement with their known physico-chemical properties. (J.S.)

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

[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

Reaction of phosphorus ylides with carbonyl compounds in supercritical carbon dioxide

Energy Technology Data Exchange (ETDEWEB)

Jeong, Kyung Il; Kim, Hak Do; Shim, Jae Jin; Ra, Choon Sup [Yeungnam Univ., Gyongsan (Korea, Republic of)

2004-02-15

The condensation reaction of (benzylene)triphenylphosphoranes with carbonyl compounds in supercritical carbon dioxide was examined. Reactions of (benzylene)phosphoranes (ca. 1 mmol) with several benzaldehydes in a supercritical carbon dioxide (80 .deg. C, 2,000 psi) containing THF entrainer (5%) in a 24 mL reactor proceed smoothly to yield olefination products in fairly good to excellent yields but slower, compared to reactions in a conventional THF solvent. Generally, phosphoranes that are not substituted with a nitro group show more (Z)-selective reactions with aromatic aldehydes under scCO{sub 2} condition than in THF. The reaction of (benzylene)triphenylphosphosphoranes with 4-t-butylcyclohexanone gave the corresponding olefin compounds with a low conversion under both the supercritical carbon dioxide and the organic THF solvent. Our preliminary study showed the Wittig reaction carries out smoothly in supercritical carbon dioxide medium and also a possible tunability of this reaction pathway by adding a entrainer. The results would be useful for devising a novel process for the environmentally friendly Wittig reaction.

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.

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

International Nuclear Information System (INIS)

Loefgren, Anders

2011-12-01

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 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

Use of some inorganic and organic compounds as decontaminants for cobalt-60 and caesium-134 by clover plant grown on Inshas sandy soil

Energy Technology Data Exchange (ETDEWEB)

Abdel Sabour, M.F.; El-Naggar, H.A.; Soliman, S.M. (Atomic Energy Establishment, Cairo (Egypt). Nuclear Chemistry Dept.)

1991-01-01

Outdoor lysimeter experiments were carried out to elucidate the effect of 4 inorganic and 3 organic salts on {sup 60}Co and {sup 134}Cs uptake and dry matter yield of three cuts of clover in the soils of Inshas. A new concept was proposed for assessing the difference in capacity of soil to supply radionuclides to plants as affected by applied inorganic or organic compounds. A relation of plant tissue radionuclide content with time can be expressed in an exponential equation with corresponding regression coefficients. When the same plant species is grown on the same soil differing only in the applied compounds (e.g. Fe-EDDHA, Fe-DTPA, Fe-OAC, Fe(COO){sub 2}, Al(OH){sub 3}, Ca(H{sub 2}PO{sub 4}){sub 2}, Fe{sub 2}O{sub 3}) the derived equation will change. Differences of either Co or Cs accumulation with time between control and any other treatment were evaluated. The data also show that Fe-DTPA is preferred for {sup 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 {sup 134}Cs taken by clover. It was also found that more than 70% of the total cobalt uptake was accumulated in the roots which indicate that Co is less mobile in plants than Cs. (orig.).

Use of some inorganic and organic compounds as decontaminants for cobalt-60 and caesium-134 by clover plant grown on Inshas sandy soil

International Nuclear Information System (INIS)

Abdel Sabour, M.F.; El-Naggar, H.A.; Soliman, S.M.

1991-01-01

Outdoor lysimeter experiments were carried out to elucidate the effect of 4 inorganic and 3 organic salts on 60 Co and 134 Cs uptake and dry matter yield of three cuts of clover in the soils of Inshas. A new concept was proposed for assessing the difference in capacity of soil to supply radionuclides to plants as affected by applied inorganic or organic compounds. A relation of plant tissue radionuclide content with time can be expressed in an exponential equation with corresponding regression coefficients. When the same plant species is grown on the same soil differing only in the applied compounds (e.g. Fe-EDDHA, Fe-DTPA, Fe-OAC, Fe(COO) 2 , Al(OH) 3 , Ca(H 2 PO 4 ) 2 , Fe 2 O 3 ) the derived equation will change. Differences of either Co or Cs accumulation with time between control and any other treatment were evaluated. The data also show 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. It was also found that more than 70% of the total cobalt uptake was accumulated in the roots which indicate that Co is less mobile in plants than Cs. (orig.) [de

Effects of inorganic substances on water splitting in ion-exchange membranes; II. Optimal contents of inorganic substances in preparing bipolar membranes.

Science.gov (United States)

Kang, Moon-Sung; Choi, Yong-Jin; Moon, Seung-Hyeon

2004-05-15

An approach to enhancing the water-splitting performance of bipolar membranes (BPMs) is introducing an inorganic substance at the bipolar (BP) junction. In this study, the immobilization of inorganic matters (i.e., iron hydroxides and silicon compounds) at the BP junction and the optimum concentration have been investigated. To immobilize these inorganic matters, novel methods (i.e., electrodeposition of the iron hydroxide and processing of the sol-gel to introduce silicon groups at the BP junction) were suggested. At optimal concentrations, the immobilized inorganic matters significantly enhanced the water-splitting fluxes, indicating that they provide alternative paths for water dissociation, but on the other hand possibly reduce the polarization of water molecules between the sulfonic acid and quaternary ammonium groups at high contents. Consequently, the amount of inorganic substances introduced should be optimized to obtain the maximum water splitting in the BPM.

A clinical and histopathological comparison of the effectiveness of salicylic acid to a compound of inorganic acids for the treatment of digital dermatitis in cattle

DEFF Research Database (Denmark)

Capion, N.; Larsson, E. K.; Nielsen, O. L.

2018-01-01

; however, the demand for effective nonantibiotic alternatives is increasing. The objective was to evaluate the performance of 3 nonantibiotic topical treatments (salicylic acid and a compound of inorganic acids in a 20% solution and in a dry form) on DD in a commercial dairy herd. Within the 30-d test...... of spirochetes present in the epidermis), 2 (moderate number of spirochetes present and reaching an intermediary level in the epidermis), and 3 (large number of spirochetes present and reaching the deepest part of the epidermis or the superficial dermis). The improvement rate was 10/14 (71%) for salicylic acid......, 11/15 (73%) for the inorganic acid solution, and 8/13 (62%) for the inorganic acid powder. The analysis showed no difference among treatments. The association between clinical score and histopathological score was determined by an odds ratio. The odds ratio of a healed lesion having spirochetes...

Corrosion performance of inorganic coatings in seawater

NARCIS (Netherlands)

Zhang, X.; Buter, S.J.; Ferrari, G.M.; Westing, E. van; Kowalski, L.

2011-01-01

Inorganic coatings are widely used to protect carbon steel hydraulic cylinder rods from wear and corrosion in aggressive offshore environment. Different types of lay-ers such as Ni/Cr, Al2O3, Cr2O3, TiO2, and Inconel 625 layers were applied to the carbon steels by plasma, High Velocity Oxygen Fuel

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

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

International Nuclear Information System (INIS)

Rard, J.A.

1983-01-01

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

Biogas pre-upgrading by adsorption of trace compounds onto granular activated carbons and an activated carbon fiber-cloth.

Science.gov (United States)

Boulinguiez, B; Le Cloirec, P

2009-01-01

The study assesses the adsorption onto activated carbon materials of selected volatile organic compounds -VOCs- (dichloromethane, 2-propanol, toluene, siloxane D4) in a biogas matrix composed of methane and carbon dioxide (55:45 v/v). Three different adsorbents are tested, two of them are granular activated carbon (GAC), and the last is an activated carbon fiber-cloth (ACFC). The adsorption isotherm data are fitted by different models by nonlinear regression. The Langmuir-Freundlich model appears to be the adequate one to describe the adsorption phenomena independently of the VOC considered or the adsorbent. The adsorbents present attractive adsorption capacity of the undesirable compounds in biogas atmosphere though the maximum adsorption capacities for a VOC are quite different from each other. The adsorption kinetics are characterized through three coefficients: the initial adsorption coefficient, the external film mass transfer coefficient and the internal diffusion coefficient of Weber. The ACFC demonstrates advanced kinetic yields compared to the granular activated carbon materials whatever VOC is considered. Therefore, pre-upgrading of biogas produced from wastewater sludge or co-digestion system by adsorption onto activated carbon appears worth investigating. Especially with ACFC material that presents correct adsorption capacities toward VOCs and concrete regeneration process opportunity to realize such process.

An inorganic CO2 diffusion and dissolution process explains negative CO2 fluxes in saline/alkaline soils

Science.gov (United States)

Ma, Jie; Wang, Zhong-Yuan; Stevenson, Bryan A.; Zheng, Xin-Jun; Li, Yan

2013-01-01

An ‘anomalous' negative flux, in which carbon dioxide (CO2) enters rather than is released from the ground, was studied in a saline/alkaline soil. Soil sterilization disclosed an inorganic process of CO2 dissolution into (during the night) and out of (during the day) the soil solution, driven by variation in soil temperature. Experimental and modeling analysis revealed that pH and soil moisture were the most important determinants of the magnitude of this inorganic CO2 flux. In the extreme cases of air-dried saline/alkaline soils, this inorganic process was predominant. While the diurnal flux measured was zero sum, leaching of the dissolved inorganic carbon in the soil solution could potentially effect net carbon ecosystem exchange. This finding implies that an inorganic module should be incorporated when dealing with the CO2 flux of saline/alkaline land. Neglecting this inorganic flux may induce erroneous or misleading conclusions in interpreting CO2 fluxes of these ecosystems. PMID:23778238

Activated Carbon Adsorption Characteristics of Multi-component Volatile Organic compounds in a Fixed Bed Adsorption Bed

Energy Technology Data Exchange (ETDEWEB)

Cho, Jong Hoon; Rhee, Young Woo [Chungnam National University, Daejeon (Korea, Republic of); Lee, Sihyun [Korea Institute of Energy Research, Daejeon (Korea, Republic of)

2016-04-15

This study aims to examine absorption characteristics of toluene, isopropyl alcohol (IPA), ethyl acetate (EA), and ternary-compounds, all of which are widely used in industrial processes, by means of four types of commercial activated carbon substances. It turned out that among the three types of volatile organic compounds, the breakthrough point of activated carbon and that of IPA, whose affinity was the lowest, were the lowest, and then that of EA and that of toluene in the order. With the breakthrough point of IPA, which was the shortest, as the standard, changes in the breakthrough points of unary-compounds, binary-compounds, and ternary-compounds were examined. As a result, it turned out that the larger the number of elements, the lower the breakthrough point. This resulted from competitive adsorption, that is, substitution of substances with a low level of affinity with those with a high level of affinity. Hence, the adsorption of toluene-IPA-EA and ternary-compounds require a design of the activated carbon bed based on the breakthrough of IPA, and in the design of activated carbon beds in actual industries as well, a substance whose level of affinity is the lowest needs to be the standard.

Form of inorganic carbon utilized for photosynthesis in Chlorella vulgaris 11h cells

International Nuclear Information System (INIS)

Miyachi, Shigetoh; Shiraiwa, Yoshihiro

1979-01-01

The rate of photosynthetic 14 CO 2 fixation in Chlorella vulgaris 11h cells in the presence of 0.55 mM NaH 14 CO 3 at pH 8.0 (20 0 C) was greatly enhanced by the addition of carbonic anhydrase (CA). However, when air containing 400 ppm 14 CO 2 was bubbled through the algal suspension, the rate of 14 CO 2 fixation immediately after the start of the bubbling was suppressed by CA. These effects of CA were observed in cells which had been grown in air containing 2% CO 2 (high-CO 2 cells) as well as those grown in ordinary air (containing 0.04% CO 2 , low-CO 2 cells). We therefore concluded that, irrespective of the CO 2 concentration given to the algal cells during growth, the active species of inorganic carbon absorbed by Chlorella cells is free CO 2 and they cannot utilize bicarbonate. The effects observed in the high-CO 2 cells were much more pronounced than those in the low-CO 2 cells. This difference was accounted for by the difference in the affinity for CO 2 in photosynthesis between the high- and low-CO 2 cells. (author)

Combined electrochemical degradation and activated carbon adsorption treatments for wastewater containing mixed phenolic compounds

Energy Technology Data Exchange (ETDEWEB)

Rajkumar, D.; Palanivelu, K.; Balasubramanian, N. [Anna University, Madras (India). Center for Environmental Studies

2005-01-01

Electrochemical degradation of mixed phenolic compounds present in coal conversion wastewater was investigated in the presence of chloride as supporting electrolyte. Initially, the degradation experiments were conducted separately with 300 mg/L of individual phenolic compound in the presence of 2500 mg/L chloride using Ti/TiO{sub 2}-RuO{sub 2}-IrO{sub 2} anode at 5.4 A/dm{sup 2} current density. Comparison of the experimental results of the chemical oxygen demand (COD) removal versus charge indicated that the order of decreasing COD removal for various phenolic compounds as catechol {gt} resorcinol {gt} m-cresol {gt} o-cresol {gt} phenol {gt} p-cresol. Degradation of the mixture of phenolic compounds and high-pressure liquid chromatography (HPLC) determinations at various stages of electrolysis showed that phenolic compounds were initially converted into benzoquinone and then to lower molecular weight aliphatic compounds. The COD and the total organic carbon (TOC) removal were 83 and 58.9% after passing 32 Ah/L with energy consumption of 191.6 kWh/kg of COD removal. Experiments were also conducted to remove adsorbable organic halogens (AOX) content in the treated solution using granular activated carbon. The optimum conditions for the removal of AOX was at pH 3.0, 5 mL/min flow rate and 31.2 cm bed height. Based on the investigation, a general scheme of treatment of mixed phenolic compounds by combined electrochemical and activated carbon adsorption treatment is proposed.

Environmental Conditions Influencing Sorption of Inorganic Anions to Multiwalled Carbon Nanotubes Studied by Column Chromatography.

Science.gov (United States)

Metzelder, Florian; Schmidt, Torsten C

2017-05-02

Sorption to carbon-based nanomaterials is typically studied in batch experiments. An alternative method offering advantages to study sorption is column chromatography. Sorbent packed columns are used and sorption data are determined by relating sorbate retention to that of a nonretarded tracer. We have now for the first time applied this technique to study the influence of environmental conditions on sorption of inorganic anions (bromide, nitrite, nitrate, and iodide) to multiwalled carbon nanotubes. Deuterium oxide was used as nonretarded tracer. Sorption isotherms were best described by the Freundlich model. Sorption increased in the order bromide 4.5 the surface charge was negative, but sorption was still detectable at pH 6 and 9. Consequently, other forces than electrostatic attraction contributed to sorption. These forces may include H-bonding as indicated by sorption enthalpy determined by variation of column temperature. Overall, column chromatography represents a promising alternative in sorption studies to reveal sorbent properties.

Structure of inorganic phosphorus-nitrogen tetrahedral compounds

International Nuclear Information System (INIS)

Vitola, A.; Ronis, J.; Avotins, V.; Millers, T.

1997-01-01

The structure analysis of phosphorus-nitrogen compounds has shown the possibility of the P(O,N) 4 tetrahedra to form various kinds of structures. The wide spectrum of the properties determined by the diversity of structures marks the considerable promise to the future application of phosphorus-nitrogen compounds

Inorganic nanolayers: structure, preparation, and biomedical applications.

Science.gov (United States)

Saifullah, Bullo; Hussein, Mohd Zobir B

2015-01-01

Hydrotalcite-like compounds are two-dimensional inorganic nanolayers also known as clay minerals or anionic clays or layered double hydroxides/layered hydroxy salts, and have emerged as a single type of material with numerous biomedical applications, such as drug delivery, gene delivery, cosmetics, and biosensing. Inorganic nanolayers are promising materials due to their fascinating properties, such as ease of preparation, ability to intercalate different type of anions (inorganic, organic, biomolecules, and even genes), high thermal stability, delivery of intercalated anions in a sustained manner, high biocompatibility, and easy biodegradation. Inorganic nanolayers have been the focus for researchers over the last decade, resulting in widening application horizons, especially in the field of biomedical science. These nanolayers have been widely applied in drug and gene delivery. They have also been applied in biosensing technology, and most recently in bioimaging science. The suitability of inorganic nanolayers for application in drug delivery, gene delivery, biosensing technology, and bioimaging science makes them ideal materials to be applied for theranostic purposes. In this paper, we review the structure, methods of preparation, and latest advances made by inorganic nanolayers in such biomedical applications as drug delivery, gene delivery, biosensing, and bioimaging.

Engineered in situ bioremediation of a petroleum hydrocarbon-contaminated aquifer: assessment of mineralization based on alkalinity, inorganic carbon and stable carbon isotope balances

Science.gov (United States)

Hunkeler, Daniel; Höhener, Patrick; Bernasconi, Stefano; Zeyer, Josef

1999-04-01

A concept is proposed to assess in situ petroleum hydrocarbon mineralization by combining data on oxidant consumption, production of reduced species, CH 4, alkalinity and dissolved inorganic carbon (DIC) with measurements of stable isotope ratios. The concept was applied to a diesel fuel contaminated aquifer in Menziken, Switzerland, which was treated by engineered in situ bioremediation. In the contaminated aquifer, added oxidants (O 2 and NO 3-) were consumed, elevated concentrations of Fe(II), Mn(II), CH 4, alkalinity and DIC were detected and the DIC was generally depleted in 13C compared to the background. The DIC production was larger than expected based on the consumption of dissolved oxidants and the production of reduced species. Stable carbon isotope balances revealed that the DIC production in the aquifer originated mainly from microbial petroleum hydrocarbon mineralization, and that geochemical reactions such as carbonate dissolution produced little DIC. This suggests that petroleum hydrocarbon mineralization can be underestimated if it is determined based on concentrations of dissolved oxidants and reduced species.

The study on joining carbon/carbon composites using Ti–Ni–Si compound

International Nuclear Information System (INIS)

Wang Jie; Li Kezhi; Song Xinrui; Guo Lingjun; Li Wei; Li Zhaoqian

2012-01-01

Highlights: ► First study to join C/C composites using Ti–Ni–Si compound. ► The average joint shear strength can reach up to 23.58 MPa. ► Strong joints are apt to fracture through interlayer, interfaces and C/C matrix. ► Phase compositions in joints are varied with increasing joining temperature. - Abstract: 2D carbon/carbon (C/C) composites have been successfully joined by partial transient liquid phase (PTLP) bonding using Ti–Ni–Si compound as interlayer. The shear strengths of C/C joints were found to be affected observably by joining temperature, joining pressure and holding time. The optimum process parameters were determined at 1150 °C, 30 MPa, 45 min, and the maximum joint shear strength was obtained under this optimum process condition with an average value of 23.58 MPa. Microstructures and compositions of joints were analyzed by scanning electronic microscopy (SEM), energy disperse spectroscopy (EDS) and X-ray diffraction (XRD). Results showed that element interdiffusions and chemical reactions took place in the joining zone and various compounds including Ni 4 Si 7 Ti 4 , TiSi 2 , SiC and TiC were produced, by which compact interlayer and strong interface were formed in C/C joints. The shear morphology indicated there were three fracture modes in C/C joints and the fracture was apt to occur through interlayer, interface and C/C matrix in strong joints. Thermal shock resistance experimental results revealed that joint shear strength has a rapid drop after 5 thermal cycles and then reduces gradually with the increase of thermal cycles between room temperature and 1000 °C.

Physico-mecha-nical properties of rubber seed shell carbon – filled natural rubber compounds

Directory of Open Access Journals (Sweden)

L.O. Ekebafe

2010-07-01

Full Text Available Samples of rubber seed shells were carbonized at varying temperatures (100, 200, 300, 400, 500, 600, 700 and 800 °C for three hours each and sieved through a 150 μm screen. The portion of the rubber seed shell carbon that passed through the screen was characterized in terms of loss on ignition, surface area, moisture content, pH, bulk density, and metal content and used in compounding natural rubber. The characterization shows that the pH, conductivity, loss on ignition and the surface area increases with the increases of the heating temperature, unlike the bulk density which decreases. The compound mixes were cured using the efficient vulcanization system. Cure characteristics of compounds and physico-mechanical properties of the vulcanisates were measured as a function of filler loading along with that of N330 carbon-black filled natural rubbers. The results showed that the cure times, scorch times and the torque gradually increased, with increasing the filler content for rubber seed shell carbon-filled natural rubber, with the filler obtained at carbonizing temperature of 600 °C tending to show optimum cure indices. The physicomechanical properties of the vulcanisates increase with filler loading. The reinforcing potential of the carbonized rubber seed shell carbon was found to increase markedly for the filler obtained at the temperature range of 500-600 °C and then decreases with further increase in temperature.

Treated Wastewater Changes the Export of Dissolved Inorganic Carbon and Its Isotopic Composition and Leads to Acidification in Coastal Oceans.

Science.gov (United States)

Yang, Xufeng; Xue, Liang; Li, Yunxiao; Han, Ping; Liu, Xiangyu; Zhang, Longjun; Cai, Wei-Jun

2018-04-25

Human-induced changes in carbon fluxes across the land-ocean interface can influence the global carbon cycle, yet the impacts of rapid urbanization and establishment of wastewater treatment plants (WWTPs) on coastal ocean carbon cycles are poorly known. This is unacceptable as at present ∼64% of global municipal wastewater is treated before discharge. Here, we report surface water dissolved inorganic carbon (DIC) and sedimentary organic carbon concentrations and their isotopic compositions in the rapidly urbanized Jiaozhou Bay in northeast China as well as carbonate parameters in effluents of three large WWTPs around the bay. Using DIC, δ 13 C DIC and total alkalinity (TA) data and a tracer model, we determine the contributions to DIC from wastewater DIC input, net ecosystem production, calcium carbonate precipitation, and CO 2 outgassing. Our study shows that high-DIC and low-pH wastewater effluent represents an important source of DIC and acidification in coastal waters. In contrast to the traditional view of anthropogenic organic carbon export and degradation, we suggest that with the increase of wastewater discharge and treatment rates, wastewater DIC input may play an increasingly more important role in the coastal ocean carbon cycle.

Effects of resuspension on benthic fluxes of oxygen, nutrients, dissolved inorganic carbon, iron and manganese in the Gulf of Finland, Baltic Sea

NARCIS (Netherlands)

Almroth, E.; Tengberg, A.; Andersson, J.H.; Pakhomova, S.; Hall, P.O.J.

2009-01-01

The effect of resuspension on benthic fluxes of oxygen (O2), ammonium (NH4+), nitrate (NO3-), phosphate (PO43-), silicate (Si(OH)4), dissolved inorganic carbon (DIC), total dissolved iron (Fe) and total dissolved manganese (Mn) was studied at three different stations in the Gulf of Finland (GoF),

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

Non-covalently functionalized carbon nanostructures for synthesizing carbon-based hybrid nanomaterials.

Science.gov (United States)

Li, Haiqing; Song, Sing I; Song, Ga Young; Kim, Il

2014-02-01

Carbon nanostructures (CNSs) such as carbon nanotubes, graphene sheets, and nanodiamonds provide an important type of substrate for constructing a variety of hybrid nanomaterials. However, their intrinsic chemistry-inert surfaces make it indispensable to pre-functionalize them prior to immobilizing additional components onto their surfaces. Currently developed strategies for functionalizing CNSs include covalent and non-covalent approaches. Conventional covalent treatments often damage the structure integrity of carbon surfaces and adversely affect their physical properties. In contrast, the non-covalent approach offers a non-destructive way to modify CNSs with desired functional surfaces, while reserving their intrinsic properties. Thus far, a number of surface modifiers including aromatic compounds, small-molecular surfactants, amphiphilic polymers, and biomacromolecules have been developed to non-covalently functionalize CNS surfaces. Mediated by these surface modifiers, various functional components such as organic species and inorganic nanoparticles were further decorated onto their surfaces, resulting in versatile carbon-based hybrid nanomaterials with broad applications in chemical engineering and biomedical areas. In this review, the recent advances in the generation of such hybrid nanostructures based on non-covalently functionalized CNSs will be reviewed.

Input of particulate organic and dissolved inorganic carbon from the Amazon to the Atlantic Ocean

Science.gov (United States)

Druffel, E. R. M.; Bauer, J. E.; Griffin, S.

2005-03-01

We report concentrations and isotope measurements (radiocarbon and stable carbon) of dissolved inorganic carbon (DIC) and suspended particulate organic carbon (POC) in waters collected from the mouth of the Amazon River and the North Brazil Current. Samples were collected in November 1991, when the Amazon hydrograph was at its annual minimum and the North Brazil Current had retroflected into the equatorial North Atlantic. The DIC Δ14C results revealed postbomb carbon in river and ocean waters, with slightly higher values at the river mouth. The low DIC δ13C signature of the river end-member (-11‰) demonstrates that about half of the DIC originated from the remineralization of terrestrially derived organic matter. A linear relationship between DIC and salinity indicates that DIC was mixed nearly conservatively in the transition zone from the river mouth to the open ocean, though there was a small amount (≤10%) of organic matter remineralization in the mesohaline region. The POC Δ14C values in the river mouth were markedly lower than those values from the western Amazon region (Hedges et al., 1986). We conclude that the dominant source of POC near the river mouth and in the inner Amazon plume during November 1991 was aged, resuspended material of significant terrestrial character derived from shelf sediments, while the outer plume contained mainly marine-derived POC.

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

Functional polarity of the tentacle of the sea anemone Anemonia viridis: role in inorganic carbon acquisition.

Science.gov (United States)

Furla, P; Bénazet-Tambutté, S; Jaubert, J; Allemand, D

1998-02-01

The oral epithelial layers of anthozoans have a polarized morphology: photosynthetic endosymbionts live within endodermal cells facing the coelenteric cavity and are separated from the external seawater by the ectodermal layer and the mesoglea. To study if this morphology plays a role in the supply of inorganic carbon for symbiont photosynthesis, we measured the change in pH and the rate of OH- (H+) fluxes induced by each cell layer on a tentacle of the sea anemone Anemonia viridis. Light-induced pH increase of the medium bathing the endodermal layers led to the generation of a transepithelial pH gradient of approximately 0.8 pH units across the tentacle, whereas darkness induced acidification of this medium. The light-induced pH change was associated with an increase of total alkalinity. Only the endodermal layer was able to induce a net OH- secretion (H+ absorption). The light-induced OH- secretion by the endodermal cell layer was dependent on the presence of HCO3- in the compartment facing the ectoderm and was sensitive to several inhibitors of ion transport. [14C] HCO3- incorporation into photosynthates confirmed the ectodermal supply, the extent of which varied from 25 to > 90%, according to HCO3- availability. Our results suggest that the light-induced OH- secretion by the endodermal cell layer followed the polarized transport of HCO3- and its subsequent decarboxylation within the endodermal cell layer. This polarity may play a significant role both in inorganic carbon absorption and in the control of light-enhanced calcification in scleractinian corals.

Controls on the Origin and Cycling of Riverine Dissolved Inorganic Carbon in the Brazos River, Texas

Science.gov (United States)

Zeng, F.; Masiello, C. A.; Hockaday, W. C.

2008-12-01

Rivers are generally supersaturated in CO2 with respect to the atmosphere. However, there is little agreement on the sources and turnover times of excess CO2 in river waters. This is likely due to varying dominant controls on carbon sources (e.g. geologic setting, climate, land use, or human activities). In this study, we measured carbon isotopic signatures (δ13C and Δ14C) of riverine dissolved inorganic carbon (DIC), as well as solid state cross polarization/magic angle spinning (CP/MAS) 13C nuclear magnetic resonance (NMR) of particulate organic carbon (POC), to determine carbon sources fuelling respiration of the Brazos River in Texas. We found that sources of riverine CO2 varied significantly along the length of the Brazos. In the middle Brazos (between Graham and Waco), which is partially underlain by limestone, riverine DIC had average Δ14C of 74 ‰ and δ13C of -7.5 ‰, suggesting that riverine CO2 is derived almost entirely from contemporary carbon (less than 5 years old) with little evidence of carbonate input, probably due to the damming upstream of Waco. In the lower Brazos (downstream of Bryan), riverine DIC was highly depleted in 14C (average Δ14C = -148.5 ‰) and enriched in 13C (average δ13C= -9.32 ‰), indicative of the presence of old carbonate. Since there is no carbonate bedrock in contact with the river in this area, the most likely source of old carbonate is the shell used in road and building construction throughout the 19th century. Our results suggest that the effect of human activities superimposes and even surpasses the effect of natural controls (e.g. geologic setting and climate) on C cycling in the Brazos.

Inorganic elements and organic compounds degradation studies by gamma irradiation in used lubricating oils; Estudos de remocao de elementos inorganicos e degradacao de compostos organicos por radiacao gama em oleos lubrificantes usados

Energy Technology Data Exchange (ETDEWEB)

Scapin, Marcos Antonio

2008-07-01

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)

Polyazidopyrimidines: High Energy Compounds and Precursors to Carbon Nanotubes (Postprint)

National Research Council Canada - National Science Library

Ye, Chengfeng; Gao, Haixiang; Boatz, Jerry A; Drake, Gregory W; Twamley, Brendan; Shreeve, Jean'ne M

2006-01-01

...). The compound 4,4',6,6'-tetra(azido)azo-1,3,5-triazine (2), has a heat of formation of 2171 (6164 kJ kg -1) (Fig. 1). Recently it was demonstrated that 1 and 2 were good precursors to nano carbon nitride materials...

Methods and systems for chemoautotrophic production of organic compounds

Energy Technology Data Exchange (ETDEWEB)

Fischer, Curt R.; Che, Austin J.; Shetty, Reshma P.; Kelly, Jason R.

2018-02-27

The present disclosure identifies pathways, mechanisms, systems and methods to confer chemoautotrophic production of carbon-based products of interest, such as sugars, alcohols, chemicals, amino acids, polymers, fatty acids and their derivatives, hydrocarbons, isoprenoids, and intermediates thereof, in organisms such that these organisms efficiently convert inorganic carbon to organic carbon-based products of interest using inorganic energy, such as formate, and in particular the use of organisms for the commercial production of various carbon-based products of interest.

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 [CuII 6LnIII] 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

Synthesis and characterization of tunable coumarin- linked glasses as new class of organic/inorganic phosphors

Energy Technology Data Exchange (ETDEWEB)

Luridiana, Alberto; Pretta, Gianluca; Secci, Francesco; Frongia, Angelo [Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, Complesso universitario di Monserrato, SS 554, bivio per Sestu, Monserrato (Canada) (Italy); Chiriu, Daniele; Carbonaro, Carlo Maria; Corpino, Riccardo [Dipartimento di Fisica, Università degli Studi di Cagliari, Complesso universitario di Monserrato, SS 554, bivio per Sestu, Monserrato (Canada) (Italy); Ricci, Pier Carlo, E-mail: carlo.ricci@dsf.unica.it [Dipartimento di Fisica, Universitá degli Studi di Cagliari, S.P. Monserrato-Sestu Km 0,700, 09042 Monserrato (Canada) (Italy)

2014-10-21

It is well known that stilbene with a trans conformation is highly fluorescent. From the viewpoint of molecular structure, coumarins bear a carbon-carbon double bond which is fixed as trans conformation as in trans-stilbene through a lactone structure. This can help to avoid the trans-cis transformation of the double bond under ultraviolet (UV) irradiation as observed in stilbene compounds and results in strong fluorescence and high fluorescence quantum yield and photostability in most of coumarin derivatives. Herein we report some preliminary results about the synthesis and spectroscopic characterization of tunable coumarins and the development of a new linkage protocol for the obtainment of monolayer coumarin-covalently linked glasses. The resulting organic/inorganic coumarin/silica based Self-Assembled Monolayer (SMA) film is proposed as new phosphors for the substituting of critical raw materials, like rare earths, in photonics applications.

A robust and fast method of sampling and analysis of delta13C of dissolved inorganic carbon in ground waters.

Science.gov (United States)

Spötl, Christoph

2005-09-01

The stable carbon isotopic composition of dissolved inorganic carbon (delta13C(DIC)) is traditionally determined using either direct precipitation or gas evolution methods in conjunction with offline gas preparation and measurement in a dual-inlet isotope ratio mass spectrometer. A gas evolution method based on continuous-flow technology is described here, which is easy to use and robust. Water samples (100-1500 microl depending on the carbonate alkalinity) are injected into He-filled autosampler vials in the field and analysed on an automated continuous-flow gas preparation system interfaced to an isotope ratio mass spectrometer. Sample analysis time including online preparation is 10 min and overall precision is 0.1 per thousand. This method is thus fast and can easily be automated for handling large sample batches.

Separation of fission products using inorganic exchangers

International Nuclear Information System (INIS)

Murthy, T.S.; Balasubramanian, K.R.; Rao, K.L.N.; Venkatachalam, R.; Varma, R.N.

1981-01-01

This paper describes the separation of long lived fission products like caesium-137, strontium-90 using inorganic exchangers ammonium phosphomolybdate and zirconium antimonate. A revised flow sheet is proposed for the sequential separation of these isotopes using the above two compounds. This is a modification of the earlier scheme developed which involved the use of four inorganic exchangers namely ammonium phosphomolybdate, manganese dioxide, zirconium antimonate and polyantimonic acid. The elution of the adsorbed elements like cerium, strontium, and sodium has been studied and it has been possible to elute these using different eluting agents. (author)

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

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...

Root carbon input in organic and inorganic fertilizer-based systems

DEFF Research Database (Denmark)

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

2012-01-01

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...... was higher (31–131 %) in inorganic than in organic fertilizer-based systems. Conclusions Our findings show that macro-roots of both cereal crops and catch crops play a relatively larger role in organically managed systems than in mineral fertilizer based systems; and that the use of fixed biomass S/R ratios...

Holographic patterning of organic-inorganic photopolymerizable nanocomposites

Science.gov (United States)

Sakhno, Oksana V.; Goldenberg, Leonid M.; Smirnova, Tatiana N.; Stumpe, J.

2009-09-01

We present here novel easily processible organic-inorganic nanocomposites suitable for holographic fabrication of diffraction optical elements (DOE). The nanocomposites are based on photocurable acrylate monomers and inorganic nanoparticles (NP). The compatibility of inorganic NP with monomers was achieved by capping the NP surface with proper organic shells. Surface modification allows to introduce up to 50wt.% of inorganic NP in organic media. Depending on the NP nature (metal oxides, phosphates, semiconductors, noble metals) and their properties, the materials for both efficient DOE and multifunctional elements can be designed. Organic-inorganic composites prepared have been successfully used for the effective inscription of periodic volume refractive index structures using the holographic photopolymerization method. The nanocomposite preparation procedure, their properties and optical performance of holographic gratings are reported. The use of functional NP makes it possible to obtain effective holographic gratings having additional physical properties such as light-emission or NLO. Some examples of such functional polymer-NP structures and their possible application fields are presented. The combination of easy photo-patterning of soft organic compounds with physical properties of inorganic materials in new nanocomposites and the flexibility of the holographic patterning method allow the fabrication of mono- and multifunctional one- and multi-dimensional passive or active optical and photonic elements.

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)

Tuovinen, O.H.

1977-01-01

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

Carbon budget of a marine phytoplankton-herbivore system with carbon-14 as a tracer

International Nuclear Information System (INIS)

Copping, A.E.; Lorenzen, C.J.

1980-01-01

Adult female and stage V Calanus pacificus were fed 14 C-labeled phytoplankton in the laboratory in the form of monospecific cultures and natural populations. A carbon budget was constructed by following the 14 C activity and the specific activity, over 48 h, in the phytoplankton, copepod, dissolved organic, dissolved inorganic, and fecal carbon compartments. The average incorporation of carbon into the copepod's body was 45% of the phytoplankton carbon available. Of the phytoplankton carbon, 27% appeared as dissolved organic carbon, 24% as dissolved inorganic carbon, and 3 to 4% in the form of fecal pellets. All of the tracer was recovered at the end of the experiments. The specific activity of the phytoplankton compartment was constant throughout each experiment. The other compartments had initial specific activities of zero, or close to zero, and increased throughout the experiment. In most experiments, the copepod specific activity equalled that of the phytoplankton at the end of 48 h, while the dissolved organic carbon, dissolved inorganic carbon, and fecal specific activities remained well below that of the phytoplankton

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

Science.gov (United States)

Moreau, Sébastien; Vancoppenolle, Martin; Delille, Bruno; Tison, Jean-Louis; Zhou, Jiayun; Kotovich, Marie; Thomas, David; Geilfus, Nicolas-Xavier; Goosse, Hugues

2015-04-01

Sea ice is an active source or a sink for carbon dioxide (CO2), although to what extent is not clear. Here, we analyze CO2 dynamics within sea ice using a one-dimensional halo-thermodynamic sea ice model including gas physics and carbon biogeochemistry. The ice-ocean fluxes, and vertical transport, of total dissolved inorganic carbon (DIC) and total alkalinity (TA) are represented using fluid transport equations. Carbonate chemistry, the consumption and release of CO2 by primary production and respiration, the precipitation and dissolution of ikaite (CaCO3•6H2O) and ice-air CO2 fluxes, are also included. The model is evaluated using observations from a 6-month field study at Point Barrow, Alaska and an ice-tank experiment. At Barrow, results show that the DIC budget is mainly driven by physical processes, wheras brine-air CO2 fluxes, ikaite formation, and net primary production, are secondary factors. In terms of ice-atmosphere CO2 exchanges, sea ice is a net CO2 source and sink in winter and summer, respectively. The formulation of the ice-atmosphere CO2 flux impacts the simulated near-surface CO2 partial pressure (pCO2), but not the DIC budget. Because the simulated ice-atmosphere CO2 fluxes are limited by DIC stocks, and therefore < 2 mmol m-2 day-1, we argue that the observed much larger CO2 fluxes from eddy covariance retrievals cannot be explained by a sea ice direct source and must involve other processes or other sources of CO2. Finally, the simulations suggest that near surface TA/DIC ratios of ~2, sometimes used as an indicator of calcification, would rather suggest outgassing.

High-performance liquid ion-pair chromatography in inorganic analysis

International Nuclear Information System (INIS)

Alimarin, I.P.; Basova, E.M.; Bol'shova, T.A.; Ivanov, V.M.

1990-01-01

In literature review for the recent 15 years theoretical foundations, regularities and mechanisms of ionized compound retention in reverse-phase ion-pair chromatography are considered, possibilities and prospects of its application in inorganic analysis being demonstrated. Analytic characteristics of the methods for the determination of inorganic anions (I - , IO 3 - , MoO 4 2- , etc.), as well as metals (Zr, Hf, V, Nb, Mo, W, Ru, lanthanides, etc.) in the form of chelates, are given

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.

Ionising radiation effect on the luminescence emission of inorganic and biogenic calcium carbonates

Energy Technology Data Exchange (ETDEWEB)

Boronat, C. [CIEMAT, Av. Complutense 40, Madrid 28040 (Spain); Correcher, V., E-mail: v.correcher@ciemat.es [CIEMAT, Av. Complutense 40, Madrid 28040 (Spain); Virgos, M.D. [CIEMAT, Av. Complutense 40, Madrid 28040 (Spain); Garcia-Guinea, J. [CSIC, Museo Nacional Ciencias Naturales, José Gutiérrez Abascal 2, Madrid 28006 (Spain)

2017-06-15

Highlights: • Aragonite and biogenic Ca-carbonates could be used as a TL dosimeters. • TL can be employed for retrospective dosimetry purposes. • Calcium carbonates show an acceptable ionizing radiation sensitivity. • The stability of the radiation–induced TL remains, at least, till 700 h. - Abstract: As known, the luminescence emission of mineral phases could be potentially employed for dosimetric purposes in the case of radiological terrorism or radiation accident where conventional monitoring is not available. In this sense, this paper reports on the thermo- (TL) and cathodoluminescence (CL) emission of both biogenic (common periwinkle – littorina littorera – shell made of calcite 90% and aragonite 10%) and inorganic (aragonite 100%) Ca-rich carbonates previously characterized by X-ray diffraction and Raman spectroscopy. Whereas the aragonite sample displays the main CL waveband peaked in the red region (linked to point defects), the more intense emission obtained from the common periwinkle shell appears at higher energies (mainly associated with structural defects). The UV-blue TL emission of the samples, regardless of the origin, displays (i) an acceptable ionizing radiation sensitivity, (ii) linear dose response in the range of interest (up to 8 Gy), (iii) reasonable stability of the TL signal after 700 h of storage with an initial decay of ca. 88% for the mineral sample and 60% for the biogenic sample and maintaining the stability from 150 h onwards. (iv) The tests of thermal stability of the TL emission performed in the range of 180–320 °C confirm a continuum in the trap system.

Ionising radiation effect on the luminescence emission of inorganic and biogenic calcium carbonates

International Nuclear Information System (INIS)

Boronat, C.; Correcher, V.; Virgos, M.D.; Garcia-Guinea, J.

2017-01-01

Highlights: • Aragonite and biogenic Ca-carbonates could be used as a TL dosimeters. • TL can be employed for retrospective dosimetry purposes. • Calcium carbonates show an acceptable ionizing radiation sensitivity. • The stability of the radiation–induced TL remains, at least, till 700 h. - Abstract: As known, the luminescence emission of mineral phases could be potentially employed for dosimetric purposes in the case of radiological terrorism or radiation accident where conventional monitoring is not available. In this sense, this paper reports on the thermo- (TL) and cathodoluminescence (CL) emission of both biogenic (common periwinkle – littorina littorera – shell made of calcite 90% and aragonite 10%) and inorganic (aragonite 100%) Ca-rich carbonates previously characterized by X-ray diffraction and Raman spectroscopy. Whereas the aragonite sample displays the main CL waveband peaked in the red region (linked to point defects), the more intense emission obtained from the common periwinkle shell appears at higher energies (mainly associated with structural defects). The UV-blue TL emission of the samples, regardless of the origin, displays (i) an acceptable ionizing radiation sensitivity, (ii) linear dose response in the range of interest (up to 8 Gy), (iii) reasonable stability of the TL signal after 700 h of storage with an initial decay of ca. 88% for the mineral sample and 60% for the biogenic sample and maintaining the stability from 150 h onwards. (iv) The tests of thermal stability of the TL emission performed in the range of 180–320 °C confirm a continuum in the trap system.

Isotherm and kinetic studies on adsorption of oil sands process-affected water organic compounds using granular activated carbon.

Science.gov (United States)

Islam, Md Shahinoor; McPhedran, Kerry N; Messele, Selamawit A; Liu, Yang; Gamal El-Din, Mohamed

2018-07-01

The production of oil from oil sands in northern Alberta has led to the generation of large volumes of oil sands process-affected water (OSPW) that was reported to be toxic to aquatic and other living organisms. The toxicity of OSPW has been attributed to the complex nature of OSPW matrix including the inorganic and organic compounds primarily naphthenic acids (NAs: C n H 2n+Z O x ). In the present study, granular activated carbon (GAC) adsorption was investigated for its potential use to treat raw and ozonated OSPW. The results indicated that NA species removal increased with carbon number (n) for a fixed Z number; however, the NA species removal decreased with Z number for a fixed carbon number. The maximum adsorption capacities obtained from Langmuir adsorption isotherm based on acid-extractable fraction (AEF) and NAs were 98.5 mg and 60.9 mg AEF/g GAC and 60 mg and 37 mg NA/g GAC for raw and ozonated OSPW, respectively. It was found that the Freundlich isotherm model best fits the AEF and NA equilibrium data (r 2  ≥ 0.88). The adsorption kinetics showed that the pseudo-second order and intraparticle diffusion models were both appropriate in modeling the adsorption kinetics of AEF and NAs to GAC (r 2  ≥ 0.97). Although pore diffusion was the rate limiting step, film diffusion was still significant for assessing the rate of diffusion of NAs. This study could be helpful to model, design and optimize the adsorption treatment technologies of OSPW and to assess the performance of other adsorbents. Copyright © 2018 Elsevier Ltd. All rights reserved.

Advanced Polymeric and Organic–Inorganic Membranes for Pressure-Driven Processes

KAUST Repository

Le, Ngoc Lieu; Phuoc, Duong; Nunes, Suzana Pereira

2017-01-01

The state-of-the-art of membranes for reverse osmosis, nanofiltration, and gas separation is shortly reviewed, taking in account the most representative examples currently in application. Emphasis is also done on recent developments of advanced polymeric and organic–inorganic materials for pressure-driven processes. Many of the more recent membranes are not only polymeric but also contain an inorganic phase. Tailoring innovative materials with organic and inorganic phases coexisting in a nanoscale with multifunctionalization is an appealing approach to control at the same time diffusivity and gas solubility. Other advanced materials that are now being considered for membrane development are organic or organic–inorganic self-assemblies, metal-organic frameworks, and different forms of carbon fillers.

Advanced Polymeric and Organic–Inorganic Membranes for Pressure-Driven Processes

KAUST Repository

Le, Ngoc Lieu

2017-02-13

The state-of-the-art of membranes for reverse osmosis, nanofiltration, and gas separation is shortly reviewed, taking in account the most representative examples currently in application. Emphasis is also done on recent developments of advanced polymeric and organic–inorganic materials for pressure-driven processes. Many of the more recent membranes are not only polymeric but also contain an inorganic phase. Tailoring innovative materials with organic and inorganic phases coexisting in a nanoscale with multifunctionalization is an appealing approach to control at the same time diffusivity and gas solubility. Other advanced materials that are now being considered for membrane development are organic or organic–inorganic self-assemblies, metal-organic frameworks, and different forms of carbon fillers.

Radioisotope 45Ca labeling four calcium chemical compounds and tracing calcium bioavailability

International Nuclear Information System (INIS)

Zheng Hui; Zhen Rong; Niu Huisheng; Li Huaifen

2004-01-01

Objective: To build up a new method of the radioisotope 45 Ca labeling four calcium chemical compounds, observe and tracing bioavailability change of calcium labeled with radioisotope 45 Ca. Methods: The calcium gluconate (Ca-Glu), calcium citrate (Ca-Cit), calcium carbonate (Ca-Car) and calcium L-threonate (Ca-Thr)were labeled by radioisotope 45 Ca. Four calcium chemical compounds of 45 Ca labeling were used of calcium content 200 mg/kg in the rats and measure the absorption content and bioavailability of calcium in tissue of heart, lever spleen, stomach, kidney, brain, intestine, whole blood, urine, faeces. Results: 1) Radioisotope 45 Ca labeling calcium chemical compound has high radio intensity, more steady standard curve and recover rate. 2) The absorption of organic calcium chemical compounds is higher than the inorganic calcium chemical compound in the study of calcium bioavailability. Conclusion: The method of tracing with radioisotope 45 Ca labeling calcium chemical compounds has the characteristic of the sensitive, objective, accurate and steady in the study of calcium bioavailability

Toxicology of organic-inorganic hybrid molecules: bio-organometallics and its toxicology.

Science.gov (United States)

Fujie, Tomoya; Hara, Takato; Kaji, Toshiyuki

2016-01-01

Bio-organometallics is a research strategy of biology that uses organic-inorganic hybrid molecules. The molecules are expected to exhibit useful bioactivities based on the unique structure formed by interaction between the organic structure and intramolecular metal(s). However, studies on both biology and toxicology of organic-inorganic hybrid molecules have been incompletely performed. There can be two types of toxicological studies of bio-organometallics; one is evaluation of organic-inorganic hybrid molecules and the other is analysis of biological systems from the viewpoint of toxicology using organic-inorganic hybrid molecules. Our recent studies indicate that cytotoxicity of hybrid molecules containing a metal that is nontoxic in inorganic forms can be more toxic than that of hybrid molecules containing a metal that is toxic in inorganic forms when the structure of the ligand is the same. Additionally, it was revealed that organic-inorganic hybrid molecules are useful for analysis of biological systems important for understanding the toxicity of chemical compounds including heavy metals.

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 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 patterning the catalyst layer. Electrical field strength of 2.0 kV/cm has been realized, which is more than one...

A Comparison of Recent Organic and Inorganic Carbon Isotope Records: Why Do They Covary in Some Settings and Not In Others?

Science.gov (United States)

Oehlert, A. M.; Swart, P. K.

2013-12-01

Covariance between inorganic and organic δ13C records has been used to determine whether a deposit has been altered by diagenesis, how the dynamics of the global carbon cycle changed during the production of the sediments in the deposit, and also for chronostratigraphic correlations. Although covariant records are observed in the ancient geologic record in a variety of depositional environments, such comparisons are not widely applied to modern deposits where definitive data regarding sediment producers, sea level fluctuations, and changes in the global carbon cycle are available. This study uses paired δ13C records from cores collected by the Ocean Drilling Program from three modern periplatform settings (the Great Bahama Bank, the Great Australian Bight, and the Great Barrier Reef), and two pelagic settings (the Walvis Ridge, and the Madingley Rise). These sites were selected in order to assess the influence of several different environmental factors including; sediment and organic matter producers, sediment mineralogy, margin architecture, sea level oscillations, and sediment transport pathways. In the three periplatform settings, multiple cores arranged in a margin to basin transect were analyzed in order to provide insights into the effects of downslope sediment transport. The preliminary results of this study suggest that sea level oscillations and margin architecture may artificially generate a covarying relationship in periplatform sediments that is unrelated to changes in the global carbon cycle. Furthermore, preliminary results from the Walvis Ridge and the Madingley Rise sediments suggest that the relationship between inorganic and organic δ13C records may not always exhibit a positive covariance as is currently assumed for pelagic carbonates.

Polyazido Pyrimidines: High Energy Compounds and Precursors to Carbon Nanotubes (PREPRINT)

National Research Council Canada - National Science Library

Ye, Chengfeng; Gao, Haoxiang; Twamley, Brendan; Shreeve, Jean'ne M; Drake, Gregory W; Boatz, Jerry A

2006-01-01

...). The compound 4,4',6,6'-tetra(azido)azo-1,3,5-triazine (2), has a heat of formation of 2171 (6164 kJ kg -1). Recently it was demonstrated that 1 and 4 were good precursors to nano carbon nitride materials...

Investigation of laser-induced breakdown spectroscopy and multivariate analysis for differentiating inorganic and organic C in a variety of soils

International Nuclear Information System (INIS)

Martin, Madhavi Z.; Mayes, Melanie A.; Heal, Katherine R.; Brice, Deanne J.; Wullschleger, Stan D.

2013-01-01

Laser-induced breakdown spectroscopy (LIBS) along with multivariate analysis was used to differentiate between the total carbon (C), inorganic C, and organic C in a set of 58 different soils from 5 soil orders. A 532 nm laser with 45 mJ of laser power was used to excite the 58 samples of soil and the emission of all the elements present in the soil samples was recorded in a single spectrum with a wide wavelength range of 200–800 nm. The results were compared to the laboratory standard technique, e.g., combustion on a LECO-CN analyzer, to determine the true values for total C, inorganic C, and organic C concentrations. Our objectives were: 1) to determine the characteristic spectra of soils containing different amounts of organic and inorganic C, and 2) to examine the viability of this technique for differentiating between soils that contain predominantly organic and/or inorganic C content for a range of diverse soils. Previous work has shown that LIBS is an accurate and reliable approach to measuring total carbon content of soils, but it remains uncertain whether inorganic and organic forms of carbon can be separated using this approach. Total C and inorganic C exhibited correlation with rock-forming elements such as Al, Si, Fe, Ti, Ca, and Sr, while organic C exhibited minor correlation with these elements and a major correlation with Mg. We calculated a figure of merit (Mg/Ca) based on our results to enable differentiation between inorganic versus organic C. We obtained the LIBS validation prediction for total, inorganic, and organic C to have a coefficient of regression, r 2 = 0.91, 0.87, and 0.91 respectively. These examples demonstrate an advance in LIBS-based techniques to distinguish between organic and inorganic C using the full wavelength spectra. - Highlights: • This research has successfully identified the organic and inorganic carbon in soil. • Multivariate analysis was used to show success in building a statistical model. • Can be used to

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

International Nuclear Information System (INIS)

Vasil'ev, V.G.; Ershova, Z.V.; Nikiforov, A.S.

1982-01-01

Tritium separation from inorganic lithium compounds: Li 2 O, LiAlO 2 , Li 2 SiO 3 , Li 4 SiO 4 , LiF, LiBeF 3 , Li 2 BeF 4 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, T 2 O). Tritium is separated from lithium fluoroberyllates in the form of hydrogen (HT, T 2 ). 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 (T 2 O) or HT(T 2 ) 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

Hybrid organic-inorganic rotaxanes and molecular shuttles.

Science.gov (United States)

Lee, Chin-Fa; Leigh, David A; Pritchard, Robin G; Schultz, David; Teat, Simon J; Timco, Grigore A; Winpenny, Richard E P

2009-03-19

The tetravalency of carbon and its ability to form covalent bonds with itself and other elements enables large organic molecules with complex structures, functions and dynamics to be constructed. The varied electronic configurations and bonding patterns of inorganic elements, on the other hand, can impart diverse electronic, magnetic, catalytic and other useful properties to molecular-level structures. Some hybrid organic-inorganic materials that combine features of both chemistries have been developed, most notably metal-organic frameworks, dense and extended organic-inorganic frameworks and coordination polymers. Metal ions have also been incorporated into molecules that contain interlocked subunits, such as rotaxanes and catenanes, and structures in which many inorganic clusters encircle polymer chains have been described. Here we report the synthesis of a series of discrete rotaxane molecules in which inorganic and organic structural units are linked together mechanically at the molecular level. Structural units (dialkyammonium groups) in dumb-bell-shaped organic molecules template the assembly of essentially inorganic 'rings' about 'axles' to form rotaxanes consisting of various numbers of rings and axles. One of the rotaxanes behaves as a 'molecular shuttle': the ring moves between two binding sites on the axle in a large-amplitude motion typical of some synthetic molecular machine systems. The architecture of the rotaxanes ensures that the electronic, magnetic and paramagnetic characteristics of the inorganic rings-properties that could make them suitable as qubits for quantum computers-can influence, and potentially be influenced by, the organic portion of the molecule.

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. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Carbon-14 measurements and characterization of dissolved organic carbon in ground water

International Nuclear Information System (INIS)

Murphy, E.M.

1987-01-01

Carbon-14 was measured in the dissolved organic carbon (DOC) in ground water and compared with 14 C analyses of dissolved inorganic carbon (DIC). Two field sites were used for this study; the Stripa mine in central Sweden, and the Milk River Aquifer in southern Alberta, Canada. The Stripa mine consists of a Precambrian granite dominated by fracture flow, while the Milk River Aquifer is a Cretaceous sandstone aquifer characterized by porous flow. At both field sites, 14 C analyses of the DOC provide additional information on the ground-water age. Carbon-14 was measured on both the hydrophobic and hydrophilic organic fractions of the DOC. The organic compounds in the hydrophobic and hydrophilic fractions were also characterized. The DOC may originate from kerogen in the aquifer matrix, from soil organic matter in the recharge zone, of from a combination of these two sources. Carbon-14 analyses, along with characterization of the organics, were used to determine this origin. Carbon-14 analyses of the hydrophobic fraction in the Milk River Aquifer suggest a soil origin, while 14 C analyses of the hydrophilic fraction suggest an origin within the Cretaceous sediments (kerogen) or from the shale in contact with the aquifer

Molten carbonate fuel cell cathode with mixed oxide coating

Science.gov (United States)

Hilmi, Abdelkader; Yuh, Chao-Yi

2013-05-07

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

Kinetic and Isotherm Modelling of the Adsorption of Phenolic Compounds from Olive Mill Wastewater onto Activated Carbon

Directory of Open Access Journals (Sweden)

Alessandro A. Casazza

2015-01-01

Full Text Available The adsorption of phenolic compounds from olive oil wastewater by commercial activated carbon was studied as a function of adsorbent quantity and temperature. The sorption kinetics and the equilibrium isotherms were evaluated. Under optimum conditions (8 g of activated carbon per 100 mL, the maximum sorption capacity of activated carbon expressed as mg of caff eic acid equivalent per g of activated carbon was 35.8 at 10 °C, 35.4 at 25 °C and 36.1 at 40 °C. The pseudo-second-order model was considered as the most suitable for kinetic results, and Langmuir isotherm was chosen to bett er describe the sorption system. The results confi rmed the effi ciency of activated carbon to remove almost all phenolic compound fractions from olive mill effl uent. The preliminary results obtained will be used in future studies. The carbohydrate fraction of this upgraded residue could be employed to produce bioethanol, and adsorbed phenolic compounds can be recovered and used in different industries.

Reactions between sodium and various carbon bearing compounds

Energy Technology Data Exchange (ETDEWEB)

Raine, A C; Thorley, A W [UKAEA, Risley, Warrington, Cheshire (United Kingdom)

1980-05-01

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.

Inorganic Membranes: Preparation and Application for Water Treatment and Desalination

Directory of Open Access Journals (Sweden)

Ahmad Kayvani Fard

2018-01-01

Full Text Available Inorganic membrane science and technology is an attractive field of membrane separation technology, which has been dominated by polymer membranes. Recently, the inorganic membrane has been undergoing rapid development and innovation. Inorganic membranes have the advantage of resisting harsh chemical cleaning, high temperature and wear resistance, high chemical stability, long lifetime, and autoclavable. All of these outstanding properties made inorganic membranes good candidates to be used for water treatment and desalination applications. This paper is a state of the art review on the synthesis, development, and application of different inorganic membranes for water and wastewater treatment. The inorganic membranes reviewed in this paper include liquid membranes, dynamic membranes, various ceramic membranes, carbon based membranes, silica membranes, and zeolite membranes. A brief description of the different synthesis routes for the development of inorganic membranes for application in water industry is given and each synthesis rout is critically reviewed and compared. Thereafter, the recent studies on different application of inorganic membrane and their properties for water treatment and desalination in literature are critically summarized. It was reported that inorganic membranes despite their high synthesis cost, showed very promising results with high flux, full salt rejection, and very low or no fouling.

Inorganic Membranes: Preparation and Application for Water Treatment and Desalination

Science.gov (United States)

McKay, Gordon; Buekenhoudt, Anita; Motmans, Filip; Khraisheh, Marwan; Atieh, Muataz

2018-01-01

Inorganic membrane science and technology is an attractive field of membrane separation technology, which has been dominated by polymer membranes. Recently, the inorganic membrane has been undergoing rapid development and innovation. Inorganic membranes have the advantage of resisting harsh chemical cleaning, high temperature and wear resistance, high chemical stability, long lifetime, and autoclavable. All of these outstanding properties made inorganic membranes good candidates to be used for water treatment and desalination applications. This paper is a state of the art review on the synthesis, development, and application of different inorganic membranes for water and wastewater treatment. The inorganic membranes reviewed in this paper include liquid membranes, dynamic membranes, various ceramic membranes, carbon based membranes, silica membranes, and zeolite membranes. A brief description of the different synthesis routes for the development of inorganic membranes for application in water industry is given and each synthesis rout is critically reviewed and compared. Thereafter, the recent studies on different application of inorganic membrane and their properties for water treatment and desalination in literature are critically summarized. It was reported that inorganic membranes despite their high synthesis cost, showed very promising results with high flux, full salt rejection, and very low or no fouling. PMID:29304024

Study by mass spectrometry of the formation of cluster ions generated by laser ablation/ionization of inorganic compounds: application to the differentiation of trivalent and hexavalent chromium compounds

International Nuclear Information System (INIS)

Aubriet, Frederic

1999-01-01

The introduction of new ionization techniques allows a fast growth of mass spectrometry applications in an increasing number of fields. More particularly, the introduction of laser ablation/ionization process and the design of new instruments (laser microprobes), has been very important for a better knowledge of inorganic compound mass spectrometry. The purposes of this work were mainly focussed firstly in the understanding of cluster ions formation process by laser ablation/ionization and secondly in the development of a new mass spectrometry technique for the speciation between trivalent and hexavalent chromium compounds. We show that cluster ion formation are multiple. The difficulty to identify clearly the processes involved is due to the superposition of many mechanisms. Mostly, these processes are representative of the complexity of the gas-phase chemistry between the various species generated by laser ablation/ionization. Thus, four mechanisms for the cluster ion formation have been highlighted. The most frequently met correspond to aggregative processes of neutral molecules on precursor ions. The knowledge of the processes of cluster ion formation allows us to explain why it is possible to distinguish the oxidation number of chromium. The organigram of chromium valence speciation proposed is based on the calculation of the ratio of negative cluster ion intensities after systematic analysis of nearly twenty chromium reference compounds using the same instrumental conditions. The examination of mixtures between 1) calcium. silicon, trivalent iron or zinc oxides and 2) the standard chromium compound allows us to observe the influence of these oxides on the fingerprints of the pure chromium compounds and to determine up to which point and with which limitations, the methodology suggested, could be applied to the analysis of trivalent and hexavalent chromium compounds in complex and polyphasic matrices

Carbon-14 measurements in aquifers with methane

International Nuclear Information System (INIS)

Barker, J.F.; Fritz, P.; Brown, R.M.

1979-01-01

A survey of various groundwater systems indicates that methane is a common trace constituent and occasionally a major carbon species in groundwaters. Thermocatalytic methane had delta 13 Csub(CH 4 )>-45 per mille and microbially produced or biogenic methane had delta 13 Csub(CH 4 ) 13 C values for the inorganic carbon. Thermocatalytic methane had no apparent effect on the inorganic carbon. Because methanogenesis seriously affects the carbon isotope geochemistry of groundwaters, the correction of raw 14 C ages of affected groundwaters must consider these effects. Conceptual models are developed which adjust the 14 C activity of the groundwater for the effects of methanogenesis and for the dilution of carbon present during infiltration by simple dissolution of rock carbonate. These preliminary models are applied to groundwaters from the Alliston sand aquifer where methanogenesis has affected most samples. In this system, methanogenic bacteria using organic matter present in the aquifer matrix as substrate have added inorganic carbon to the groundwater which has initiated further carbonate rock dissolution. These processes have diluted the inorganic carbon 14 C activity. The adjusted groundwater ages can be explained in terms of the complex hydrogeology of this aquifer, but also indicate that these conceptual models must be more rigorously tested to evaluate their appropriateness. (author)

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.

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. © 2015 American Institute of Chemical Engineers.

A two-dimensional organic–inorganic hybrid compound, poly[(ethylenediaminetri-μ-oxido-oxidocopper(IImolybdenum(VI

Directory of Open Access Journals (Sweden)

Mehtap Emirdag-Eanes

2008-10-01

Full Text Available 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 respective chains along the b axis, thus establishing layers in the bc plane. The ethylenediamine ligand is coordinated to the Cu atom through its two N atoms and is oriented perpendicularly to the two-dimensional –Cu—O—Mo– layers. The average distance between adjacent layers, as calculated by consideration of the closest and furthest distances between two layers, is 8.7 Å. The oxidation states of the Mo and Cu atoms of VI and II, respectively, were confirmed by bond-valence sum calculations.

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

Science.gov (United States)

Butera, Stefania; Christensen, Thomas H; Astrup, Thomas F

2014-07-15

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) concrete waste, (ii) mixed masonry and concrete, (iii) asphalt and (iv) freshly cast concrete cores; both old and newly generated construction and demolition waste was included. PCBs and PAHs were detected in all samples, generally in non-critical concentrations. Overall, PAHs were comparable to background levels in urban environments. "Old" and "new" concrete samples indicated different PCB congener profiles and the presence of PCB even in new concrete suggested that background levels in raw materials may be an issue. Significant variability in total content of trace elements, even more pronounced for leaching, was observed indicating that the number of analysed samples may be critical in relation to decisions regarding management and utilisation of the materials. Higher leaching of chromium, sulphate and chloride were observed for masonry-containing and partly carbonated samples, indicating that source 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. Copyright © 2014 Elsevier B.V. All rights reserved.

Adsorption of volatile organic compounds by pecan shell- and almond shell-based granular activated carbons.

Science.gov (United States)

Bansode, R R; Losso, J N; Marshall, W E; Rao, R M; Portier, R J

2003-11-01

The objective of this research was to determine the effectiveness of using pecan and almond shell-based granular activated carbons (GACs) in the adsorption of volatile organic compounds (VOCs) of health concern and known toxic compounds (such as bromo-dichloromethane, benzene, carbon tetrachloride, 1,1,1-trichloromethane, chloroform, and 1,1-dichloromethane) compared to the adsorption efficiency of commercially used carbons (such as Filtrasorb 200, Calgon GRC-20, and Waterlinks 206C AW) in simulated test medium. The pecan shell-based GACs were activated using steam, carbon dioxide or phosphoric acid. An almond shell-based GAC was activated with phosphoric acid. Our results indicated that steam- or carbon dioxide-activated pecan shell carbons were superior in total VOC adsorption to phosphoric acid-activated pecan shell or almond shell carbons, inferring that the method of activation selected for the preparation of activated carbons affected the adsorption of VOCs and hence are factors to be considered in any adsorption process. The steam-activated, pecan shell carbon adsorbed more total VOCs than the other experimental carbons and had an adsorption profile similar to the two coconut shell-based commercial carbons, but had greater adsorption than the coal-based commercial carbon. All the carbons studied adsorbed benzene more effectively than the other organics. Pecan shell, steam-activated and acid-activated GACs showed higher adsorption of 1,1,1-trichloroethane than the other carbons studied. Multivariate analysis was conducted to group experimental carbons and commercial carbons based on their physical, chemical, and adsorptive properties. The results of the analysis conclude that steam-activated and acid-activated pecan shell carbons clustered together with coal-based and coconut shell-based commercial carbons, thus inferring that these experimental carbons could potentially be used as alternative sources for VOC adsorption in an aqueous environment.

Tidal day organic and inorganic material flux of ponds in the Liberty Island freshwater tidal wetland.

Science.gov (United States)

Lehman, Peggy W; Mayr, Shawn; Liu, Leji; Tang, Alison

2015-01-01

The loss of inorganic and organic material export and habitat produced by freshwater tidal wetlands is hypothesized to be an important contributing factor to the long-term decline in fishery production in San Francisco Estuary. However, due to the absence of freshwater tidal wetlands in the estuary, there is little information on the export of inorganic and organic carbon, nutrient or phytoplankton community biomass and the associated mechanisms. A single-day study was conducted to assess the potential contribution of two small vegetated ponds and one large open-water pond to the inorganic and organic material flux within the freshwater tidal wetland Liberty Island in San Francisco Estuary. The study consisted of an intensive tidal day (25.5 h) sampling program that measured the flux of inorganic and organic material at three ponds using continuous monitoring of flow, chlorophyll a, turbidity and salt combined with discrete measurements of phytoplankton community carbon, total and dissolved organic carbon and nutrient concentration at 1.5 h intervals. Vegetated ponds had greater material concentrations than the open water pond and, despite their small area, contributed up to 81% of the organic and 61% of the inorganic material flux of the wetland. Exchange between ponds was important to wetland flux. The small vegetated pond in the interior of the wetland contributed as much as 72-87% of the total organic carbon and chlorophyll a and 10% of the diatom flux of the wetland. Export of inorganic and organic material from the small vegetated ponds was facilitated by small-scale topography and tidal asymmetry that produced a 40% greater material export on ebb tide. The small vegetated ponds contrasted with the large open water pond, which imported 29-96% of the inorganic and 4-81% of the organic material into the wetland from the adjacent river. This study identified small vegetated ponds as an important source of inorganic and organic material to the wetland and the

Carbonic anhydrase 2-like in the giant clam, Tridacna squamosa: characterization, localization, response to light, and possible role in the transport of inorganic carbon from the host to its symbionts.

Science.gov (United States)

Ip, Yuen K; Koh, Clarissa Z Y; Hiong, Kum C; Choo, Celine Y L; Boo, Mel V; Wong, Wai P; Neo, Mei L; Chew, Shit F

2017-12-01

The fluted giant clam, Tridacna squamosa , lives in symbiosis with zooxanthellae which reside extracellularly inside a tubular system. Zooxanthellae fix inorganic carbon (C i ) during insolation and donate photosynthate to the host. Carbonic anhydrases catalyze the interconversion of CO 2 and HCO3-, of which carbonic anhydrase 2 (CA2) is the most ubiquitous and involved in many biological processes. This study aimed to clone a CA2 homolog ( CA2-like ) from the fleshy and colorful outer mantle as well as the thin and whitish inner mantle of T. squamosa , to determine its cellular and subcellular localization, and to examine the effects of light exposure on its gene and protein expression levels. The cDNA coding sequence of CA2-like from T. squamosa comprised 789 bp, encoding 263 amino acids with an estimated molecular mass of 29.6 kDa. A phenogramic analysis of the deduced CA2-like sequence denoted an animal origin. CA2-like was not detectable in the shell-facing epithelium of the inner mantle adjacent to the extrapallial fluid. Hence, CA2-like is unlikely to participate directly in light-enhanced calcification. By contrast, the outer mantle, which contains the highest density of tertiary tubules and zooxanthellae, displayed high level of CA2-like expression, and CA2-like was localized to the tubule epithelial cells. More importantly, exposure to light induced significant increases in the protein abundance of CA2-like in the outer mantle. Hence, CA2-like could probably take part in the increased supply of inorganic carbon (C i ) from the host clam to the symbiotic zooxanthellae when the latter conduct photosynthesis to fix C i during light exposure. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

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)

Varank, Gamze; Demir, Ahmet; Yetilmezsoy, Kaan; Bilgili, M. Sinan; Top, Selin; Sekman, Elif

2011-01-01

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 m 3 ) with different composite liners (R1: 0.10 + 0.10 m of compacted clay liner (CCL), L e = 0.20 m, k e = 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, L e = 0.20 m, k e = 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, L e = 0.22 m, k e = 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, L e = 0.22 m, k e = 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 m 2 /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 m 2 /s to 5

Analysis of hydrogen, carbon, sulfur and volatile compounds in (U3Si2 - Al) nuclear fuel

International Nuclear Information System (INIS)

Moura, Sergio C.; Redigolo, Marcelo M.; Amaral, Priscila O.; Leao, Claudio; Oliveira, Glaucia A.C. de; Bustillos, Oscar V.

2015-01-01

Uranium silicide U 3 Si 2 is used as nuclear fuel in the research nuclear reactor IEA-R1 at IPEN/CNEN, Sao Paulo, Brazil. The U 3 Si 2 is dispersed in aluminum reaching high densities of uranium in the nucleus of the fuel, up to 4.8 gU cm -3 . This nuclear fuel must comply with a quality control, which includes analysis of hydrogen, carbon and sulfur for the U 3 Si 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 -1 and 3 μg g -1 , respectively, and 40 μg g -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)

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)

Abdel-Sabour, M.F.; El-naggr, H.A.; Soliman, S.M.

1994-01-01

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 (P c ) 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 O 4 )2 and Fe 2 O 3 ) 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')/(A B + 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

Inorganic nanolayers: structure, preparation, and biomedical applications

Directory of Open Access Journals (Sweden)

Saifullah B

2015-09-01

Full Text Available Bullo Saifullah, Mohd Zobir B HusseinMaterials Synthesis and Characterization Laboratory, Institute of Advanced Technology (ITMA, Universiti Putra Malaysia, Serdang, MalaysiaAbstract: Hydrotalcite-like compounds are two-dimensional inorganic nanolayers also known as clay minerals or anionic clays or layered double hydroxides/layered hydroxy salts, and have emerged as a single type of material with numerous biomedical applications, such as drug delivery, gene delivery, cosmetics, and biosensing. Inorganic nanolayers are promising materials due to their fascinating properties, such as ease of preparation, ability to intercalate different type of anions (inorganic, organic, biomolecules, and even genes, high thermal stability, delivery of intercalated anions in a sustained manner, high biocompatibility, and easy biodegradation. Inorganic nanolayers have been the focus for researchers over the last decade, resulting in widening application horizons, especially in the field of biomedical science. These nanolayers have been widely applied in drug and gene delivery. They have also been applied in biosensing technology, and most recently in bioimaging science. The suitability of inorganic nanolayers for application in drug delivery, gene delivery, biosensing technology, and bioimaging science makes them ideal materials to be applied for theranostic purposes. In this paper, we review the structure, methods of preparation, and latest advances made by inorganic nanolayers in such biomedical applications as drug delivery, gene delivery, biosensing, and bioimaging.Keywords: inorganic nanolayers, layered double hydroxides, layered hydroxy salts, drug delivery, biosensors, bioimaging

Correlation between rheological and mechanical properties of black PE100 compounds – Effect of carbon black masterbatch

Directory of Open Access Journals (Sweden)

G. Pircheraghi

2017-08-01

Full Text Available Black PE100 compounds were prepared using a co-rotating twin screw extruder by addition of carbon black masterbatches containing 35–40 wt% carbon black and different polymer carriers to a pipe grade PE100 material with bimodal molecular weight distribution. Different properties of carbon black masterbatches and PE100 black compounds were evaluated using thermal, rheological and mechanical tests. Rheological results indicated an inverse correlation between melt flow index (MFI of masterbatch samples and storage modulus, complex viscosity and shear viscosity of black compounds, while flow instabilities of compounds were also postponed to higher shear rates. TGA indicated that masterbatch with highest value of MFI contained highest amount of low molecular weight lubricants which resulted in inhibition of strain hardening behavior in tensile test of its respective black compound unlike all other samples, reflecting possible suppressing of its long term resistance to slow crack growth. This behavior is attributable to facilitated crystallization and chain folding of longer chains in the presence of low molecular weight lubricants in this sample and consequently formation of thicker lamellas as confirmed by DSC, hence lowering density of entanglements in amorphous area and inhibition of strain hardening.

Organic-Inorganic Perovskites: Structural Versatility for Functional Materials Design.

Science.gov (United States)

Saparov, Bayrammurad; Mitzi, David B

2016-04-13

Although known since the late 19th century, organic-inorganic perovskites have recently received extraordinary research community attention because of their unique physical properties, which make them promising candidates for application in photovoltaic (PV) and related optoelectronic devices. This review will explore beyond the current focus on three-dimensional (3-D) lead(II) halide perovskites, to highlight the great chemical flexibility and outstanding potential of the broader class of 3-D and lower dimensional organic-based perovskite family for electronic, optical, and energy-based applications as well as fundamental research. The concept of a multifunctional organic-inorganic hybrid, in which the organic and inorganic structural components provide intentional, unique, and hopefully synergistic features to the compound, represents an important contemporary target.

Forecasting of heat capacity of molecular inorganic liquids

International Nuclear Information System (INIS)

Sladkov, I.B.; Neganov, O.S.

1992-01-01

On the basis of analysis of experimental material on heat capacity of liquids, covering 350 molecular inorganic compounds, atomic parts of heat capacity for 58 elements of the Periodic system were obtained. Data on the accuracy of heat capacity calculation by the Neumann-Kopp rule using the recommended atomic parts C p are presented. For the Kelli rule it is assertained that the factor of proportiomality between heat capacity and the number of atoms in compound molecule in the general case depends on the type of anion and compound coordination. The Neumann-Kopp-Kelli rules provide a satisfactory accuracy of prediction

Synthesis of boronate-functionalized organic-inorganic hybrid monolithic column for the separation of cis-diol containing compounds at low pH.

Science.gov (United States)

Zhao, Heqing; Lyu, Haixia; Qin, Wenfei; Xie, Zenghong

2018-04-01

In this work, an organic-inorganic hybrid boronate affinity monolithic column was prepared via "one-pot" process using 4-vinylphenylboronic acid as organic monomer and divinylbenzene as cross-linker. The effects of reaction temperature, solvents and composition of organic monomers on the column properties (e.g. morphology, permeability, and mechanical stability) were investigated. A series of test compounds including small neutral molecules, aromatic amines, and cis-diol compounds were used to evaluate the retention behaviors of the prepared hybrid monolithic column. The results demonstrated that the prepared hybrid monolith exhibited mixed-interactions including hydrophilicity, cation exchange, and boronate affinity interaction. The run-to-run, day-to-day and batch-to-batch reproducibilities of the prepared hybrid monolith for thiourea's retention time were satisfactory with the relative standard deviations (RSDs) less than 0.09, 1.45 and 4.05% (n = 3), respectively, indicating the effectiveness and practicability of the proposed method. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Crystallization of an organic compound from an ionic liquid using carbon dioxide as anti-solvent

NARCIS (Netherlands)

Kroon, M.C.; Toussaint, V.A.; Shariati - Sarabi, A.; Florusse, L.J.; Spronsen, van J.; Witkamp, G.J.; Peters, C.J.

2008-01-01

In this paper the anti-solvency behavior of supercritical carbon dioxide (CO2) as a way to recover an organic compound from an ionic liquid by crystallization is explored. As an example, the conditions for crystallization of the organic compound methyl-(Z)-a-acetamido cinnamate (MAAC) from the ionic

Crystal structure, thermochromic and magnetic properties of organic-inorganic hybrid compound: (C7H7N2S)2CuCl4

Science.gov (United States)

Vishwakarma, Ashok K.; Kumari, Reema; Ghalsasi, Prasanna S.; Arulsamy, Navamoney

2017-08-01

The synthesis, thermal analysis, crystal structure and magnetic properties of (2-aminobenzothiazolium)2CuCl4, organic-inorganic hybrid compound, have been described. The compound crystallizes in the monoclinic space group P21/c with two formula units in a unit cell of dimensions a = 6.9522(4) Å, b = 9.6979(4) Å, c = 13.9633(6) Å, β = 97.849(3)° and volume 930.83(8) Å3 at 150(2) K. The structure consists of isolated nearly square planer [CuC14]2- units, with somewhat longer than normal Cusbnd Cl bond lengths [Cusbnd Cl (average) = 2.2711 Å]. The magnetic measurements of (2-aminobenzothiazolium)2CuCl4 using SQUID magnetometer show paramagnetic nature of the compound. Thermal measurements (TG-DTA and DSC) on this compound showed reversible phase transition at 83 °C. This transition is accompanied by the reversible change in colour of the prismatic crystal from green to dark brown, thermochromic behaviour. Temperature dependent EPR measurements on powdered sample ascertain change in coordination sphere around Cu(II) with shift in g|| = 2.150 and g⊥ = 2.071 at room temperature, typical of square planar, to g|| = 2.201 and g⊥ = 2.182 at 170 °C, typical of distorted tetrahedral geometry.

Oxidative treatment of bromide-containing waters: formation of bromine and its reactions with inorganic and organic compounds--a critical review.

Science.gov (United States)

Heeb, Michèle B; Criquet, Justine; Zimmermann-Steffens, Saskia G; von Gunten, Urs

2014-01-01

Bromide (Br(-)) is present in all water sources at concentrations ranging from ≈ 10 to >1000 μg L(-1) in fresh waters and about 67 mg L(-1) in seawater. During oxidative water treatment bromide is oxidized to hypobromous acid/hypobromite (HOBr/OBr(-)) and other bromine species. A systematic and critical literature review has been conducted on the reactivity of HOBr/OBr(-) and other bromine species with inorganic and organic compounds, including micropollutants. The speciation of bromine in the absence and presence of chloride and chlorine has been calculated and it could be shown that HOBr/OBr(-) are the dominant species in fresh waters. In ocean waters, other bromine species such as Br2, BrCl, and Br2O gain importance and may have to be considered under certain conditions. HOBr reacts fast with many inorganic compounds such as ammonia, iodide, sulfite, nitrite, cyanide and thiocyanide with apparent second-order rate constants in the order of 10(4)-10(9)M(-1)s(-1) at pH 7. No rate constants for the reactions with Fe(II) and As(III) are available. Mn(II) oxidation by bromine is controlled by a Mn(III,IV) oxide-catalyzed process involving Br2O and BrCl. Bromine shows a very high reactivity toward phenolic groups (apparent second-order rate constants kapp ≈ 10(3)-10(5)M(-1)s(-1) at pH 7), amines and sulfamides (kapp ≈ 10(5)-10(6)M(-1)s(-1) at pH 7) and S-containing compounds (kapp ≈ 10(5)-10(7)M(-1)s(-1) at pH 7). For phenolic moieties, it is possible to derive second-order rate constants with a Hammett-σ-based QSAR approach with [Formula in text]. A negative slope is typical for electrophilic substitution reactions. In general, kapp of bromine reactions at pH 7 are up to three orders of magnitude greater than for chlorine. In the case of amines, these rate constants are even higher than for ozone. Model calculations show that depending on the bromide concentration and the pH, the high reactivity of bromine may outweigh the reactions of chlorine during

Chemical sensors of benzene and toluene based on inorganic and hybrid organic-inorganic polymers elaborated by a sol-gel process

International Nuclear Information System (INIS)

Calvo Munoz, Maria Luisa

2000-01-01

As mono-cyclic aromatic hydrocarbons (MAH) are a matter of concern in terms of pollution, and are to be monitored due to new regulations regarding air quality control, this research thesis first aims at explaining why these compounds are to be monitored, at recalling their sources, at outlining what we know about their negative impact on health and how this impact is determined, which are the means implemented to monitor these compounds and which are their drawbacks, and at recalling which requirements are defined by European directives. The author then reports a literature survey of the current technology regarding chemical sensors, and identifies the required characteristics of an ideal sensor. The author proposes a review of studied performed on sol-gel process and of inorganic polymer synthesis methods based on sol-gel process. He reports the synthesis and characterization of inorganic or hybrid organic-inorganic host matrices, monolithic or in thin layers, used to produce MAH sensors. A matrix pore local polarity study is reported. Benzene and toluene trapping is studied with respect to the polarity and thickness of the host matrix. Pollutant trapping is directly monitored by their absorption in the near-UV and visible range. The author finally reports the study of interactions between fluorescent probe molecules and pollutants, as well as the effect of an interfering gas (oxygen) on the fluorescence of probe molecules [fr

Crystal structure and electrical conduction of the new organic-inorganic compound (CH2)2(NH3)2CdI4

Science.gov (United States)

Zhang, Liuqi; Wang, Jilin; Han, Feifei; Mo, Shuyi; Long, Fei; Gao, Yihua

2018-03-01

The new organic-inorganic compound (CH2)2(NH3)2CdI4 was prepared by slow evaporation method using a mixture solution of CdI2 and ethylenediamine iodide (EDAI) in the γ-butyrolactone (GBL). The synthesized compound was further characterized by single crystal diffraction, Infrared (IR) and Raman spectroscopy, energy dispersive spectrometer (EDS), X-Ray photoelectron spectroscopy (XPS) and thermogravimetric analysis. The relaxation behavior and conductivity mechanism of (CH2)2(NH3)2CdI4 was studied by the electrical impedance spectroscopy. The results indicated that (CH2)2(NH3)2CdI4 had a monoclinic structure with space group P21/c at room temperature. The complex impedance plotted as semicircle arcs and the proposed electrical equivalent circuit was to interpret the impedance behavior at different temperatures. The electrical equivalent circuit was made of a parallel combination of resistance (R) and fractal capacitance (CPE). Furthermore, the alternating current conductivity of the sample obeyed the Jonscher's law: σf =σdc + Afs and the conduction could be attributed to the correlated barrier hopping (CBH) model.

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)

Vende, L.

2012-01-01

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 ( 14 CO 2 , HT...) or in solution ( 14 CO 3 2- , 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)

Inorganic Nanotubes and Fullerene-Like Nanoparticles:. from the Lab to the Market Place

Science.gov (United States)

Tenne, R.

2013-05-01

Layered compounds, like MoS2 were shown by the author to be unstable in the nano-regime. Using new chemical strategies, closed-cage hollow nanostructures in the form of inorganic fullerene-like nanoparticles and inorganic nanotubes were synthesized. These nanostructures exhibit numerous interesting physico-chemical properties and are employed as superior solid lubricants, with numerous other applications currently being developed.

Solubility of carbon monoxide in bio-oil compounds

International Nuclear Information System (INIS)

Qureshi, Muhammad Saad; Le Nedelec, Tom; Guerrero-Amaya, Hernando; Uusi-Kyyny, Petri; Richon, Dominique; Alopaeus, Ville

2017-01-01

Highlights: • CO solubility was measured in four bio-oil compounds using static-analytic VLE equipment. • A comparison on the performance of different EoS (PC-SAFT, SRK and PR) was made. • Modelling of polar compounds with Polar PC-SAFT was tested. • Polar PC-SAFT is not needed for weakly polar compounds (μ < 1.0 D). - Abstract: The solubility of carbon monoxide is measured in four different bio-oil compounds (furan, diacetyl, 2-methylfuran, and trans-crotonaldehyde) at temperatures (273.15, 283.15, 298.15, and 323.15 K) and pressures up to 8 MPa using a static-analytical VLE measurement method. The equipment was validated by measuring the solubility of CO 2 in methanol at 298.15 K and pressures (P = 2.9–5.7 MPa). The results were compared with the abundantly available literature values. PC-SAFT, Polar PC-SAFT (PPC-SAFT), and Cubic (SRK, PR) EoS, part of commercial process simulator Aspen Plus V. 8.6, are used here for modelling purpose. The pure component parameters needed for PC-SAFT and PPC-SAFT EoS models, are regressed using the experimental liquid density and vapour pressure data of the pure components. It was observed that furan, 2-methylfuran and diacetyl, having weak dipole moments (μ < 1.0 D), could be modelled reasonably well without the addition of polar contribution using conventional PC-SAFT, while it is recommended to use PPC-SAFT for the description of a polar compound like trans-crotonaldehyde (μ ∼ 3.67 D). It was observed that SRK and PR EoS have similar predictive ability in comparison to PC-SAFT for a mixture of CO with weakly polar compounds in this study. A comparison between the performances of EoS models was made in two ways: first by setting the binary interaction parameter k ij to zero, and second by adjusting a temperature-dependent binary interaction parameter (k ij ). All the models perform with comparable accuracy with adjusted binary interaction parameters. However, due to the large differences between the chemical and

A review of the inorganic and organometallic chemistry of zirconium

International Nuclear Information System (INIS)

Kalvins, A.K.

1985-01-01

The results of a literature review of the inorganic and organometallic chemistry of zirconium are presented. Compounds with physical and chemical properties compatible with the requirements of an ir laser zirconium isotope separation process have been identified

Inorganic chemistry and medicine

International Nuclear Information System (INIS)

Sadler, P.J.; Guo, Z.

1999-01-01

Inorganic chemistry is beginning to have a major impact on medicine. Not only does it offer the prospect of the discovery of truly novel drugs and diagnostic agents, but it promises to make a major contribution to our understanding of the mechanism of action of organic drugs too. Most of this article is concerned with recent developments in medicinal coordination chemistry. The role of metal organic compounds of platinum, titanium, ruthenium, gallium, bismuth, gold, gadolinium, technetium, silver, cobalt in the treatment or diagnosis of common diseases are briefly are examined

Biogenic, urban, and wildfire influences on the molecular composition of dissolved organic compounds in cloud water

Science.gov (United States)

Cook, Ryan D.; Lin, Ying-Hsuan; Peng, Zhuoyu; Boone, Eric; Chu, Rosalie K.; Dukett, James E.; Gunsch, Matthew J.; Zhang, Wuliang; Tolic, Nikola; Laskin, Alexander; Pratt, Kerri A.

2017-12-01

Organic aerosol formation and transformation occurs within aqueous aerosol and cloud droplets, yet little is known about the composition of high molecular weight organic compounds in cloud water. Cloud water samples collected at Whiteface Mountain, New York, during August-September 2014 were analyzed by ultra-high-resolution mass spectrometry to investigate the molecular composition of dissolved organic carbon, with a focus on sulfur- and nitrogen-containing compounds. Organic molecular composition was evaluated in the context of cloud water inorganic ion concentrations, pH, and total organic carbon concentrations to gain insights into the sources and aqueous-phase processes of the observed high molecular weight organic compounds. Cloud water acidity was positively correlated with the average oxygen : carbon ratio of the organic constituents, suggesting the possibility for aqueous acid-catalyzed (prior to cloud droplet activation or during/after cloud droplet evaporation) and/or radical (within cloud droplets) oxidation processes. Many tracer compounds recently identified in laboratory studies of bulk aqueous-phase reactions were identified in the cloud water. Organosulfate compounds, with both biogenic and anthropogenic volatile organic compound precursors, were detected for cloud water samples influenced by air masses that had traveled over forested and populated areas. Oxidation products of long-chain (C10-12) alkane precursors were detected during urban influence. Influence of Canadian wildfires resulted in increased numbers of identified sulfur-containing compounds and oligomeric species, including those formed through aqueous-phase reactions involving methylglyoxal. Light-absorbing aqueous-phase products of syringol and guaiacol oxidation were observed in the wildfire-influenced samples, and dinitroaromatic compounds were observed in all cloud water samples (wildfire, biogenic, and urban-influenced). Overall, the cloud water molecular composition depended on

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.

Application of self-organising maps towards segmentation of soybean samples by determination of inorganic compounds content.

Science.gov (United States)

Cremasco, Hágata; Borsato, Dionísio; Angilelli, Karina Gomes; Galão, Olívio Fernandes; Bona, Evandro; Valle, Marcos Eduardo

2016-01-15

In this study, 20 samples of soybean, both transgenic and conventional cultivars, which were planted in two different regions, Londrina and Ponta Grossa, both located at Paraná, Brazil, were analysed. In order to verify whether the inorganic compound levels in soybeans varied with the region of planting, K, P, Ca, Mg, S, Zn, Mn, Fe, Cu and B contents were analysed by an artificial neural network self-organising map. It was observed that with a topology 10 × 10, 8000 epochs, initial learning rate of 0.1 and initial neighbourhood ratio of 4.5, the network was able to differentiate samples according to region of origin. Among all of the variables analysed by the artificial neural network, the elements Zn, Ca and Mn were those which most contributed to the classification of the samples. The results indicated that samples planted in these two regions differ in their mineral content; however, conventional and transgenic samples grown in the same region show no difference in mineral contents in the grain. © 2015 Society of Chemical Industry.

Mesoporous nitrogen-doped carbon microfibers derived from Mg-biquinoline-dicarboxy compound for efficient oxygen electroreduction

Energy Technology Data Exchange (ETDEWEB)

Kong, Aiguo, E-mail: agkong@chem.ecnu.edu.cn [School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241 (China); Fan, Xiaohong; Chen, Aoling [School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241 (China); Zhang, Hengiang [School of Chemistry and Chemical Engineering, Hebei Normal University for Nationalities, Chengde 067000 (China); Shan, Yongkui, E-mail: agkong@chem.ecnu.edu.cn [School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241 (China)

2017-02-15

An in-situ MgO-templating synthesis route was introduced to obtain the mesoporous nitrogen-doped carbon microfibers by thermal conversion of new Mg-2,2′-biquinoline 4,4-dicarboxy acid coordination compound (Mg-DCA) microfibers. The investigated crystal structure of Mg-DCA testified that the assembling of Mg{sup 2+} and DCA through Mg-O coordination bond and hydrogen bond contributed to the formation of one-dimensional (1D) crystalline Mg-DCA microfibers. The nitrogen-doped carbons derived from the pyrolysis of Mg-DCA showed the well-defined microfiber morphology with high mesopore-surface area. Such mesoporous microfibers exhibited the efficient catalytic activity for oxygen reduction reaction (ORR) in alkaline solutions with better stability and methanol-tolerance performance. - Graphical abstract: Mesoporous nitrogen-doped carbon microfibers with efficient oxygen electroreduction activity were prepared by thermal conversion of new Mg-biquinoline-based coordination compound microfibers.

Stable isotope composition of inorganic carbonates from Lake Abiyata (Ethiopia): Attempt of reconstructing δ18O palaeohydrological changes during the Holocene

International Nuclear Information System (INIS)

Gibert, E.; Massault, M.; Travi, Y.; Chernet, T.

2002-01-01

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 14 C-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 14 C-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 δ 18 O 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 18 O 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 δ 18 O enrichment of the lake

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

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Stéphanie Gérin

2016-08-01

Full Text Available 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

Organic and inorganic carbon dynamics in a karst aquifer: Santa Fe River Sink-Rise system, north Florida, USA

Science.gov (United States)

Jin, Jin; Zimmerman, Andrew R.; Moore, Paul J.; Martin, Jonathan B.

2014-03-01

Spatiotemporal variations in dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), major ions concentrations and other geochemical parameters including stable carbon isotopes of DIC (δ13CDIC), were measured in surface water and deep and shallow well water samples of the Santa Fe River Sink-Rise eogenetic karst system, north Florida, USA. Three end-member water sources were identified: one DOC-rich/DIC-poor/δ13CDIC-depleted, one DOC-poor/DIC-rich/δ13CDIC-enriched, and one enriched in major ions. Given their spatiotemporal distributions, they were presumed to represent soil water, upper aquifer groundwater, and deep aquifer water sources, respectively. Using assumed ratios of Na+, Cl, and SO42- for each end-member, a mixing model calculated the contribution of each water source to each sample. Then, chemical effects of biogeochemical reactions were calculated as the difference between those predicted by the mixing model and measured species concentrations. In general, carbonate mineral dissolution occurred throughout the Sink-Rise system, surface waters were net autotrophic and the subsurface was in metabolic balance, i.e., no net DOC or DIC production or consumption. However, there was evidence for chemolithoautotrophy, perhaps by hydrogen oxidizing microbes, at some deep aquifer sites. Mineralization of this autochthonous natural dissolved organic matter (NDOM) led to localized carbonate dissolution as did surface water-derived NDOM supplied to shallow well sites during the highest flow periods. This study demonstrates linkages between hydrology, abiotic and microbial processes and carbon dynamics and has important implications for groundwater quality, karst morphologic evolution, and hydrogeologic projects such as aquifer storage and recovery in karst systems.

40 CFR 123.45 - Noncompliance and program reporting by the Director.

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2010-07-01

... Demand Total Oxygen Demands Total Organic Carbon Other Solids Total Suspended Solids (Residues) Total Dissolved Solids (Residues) Other Nutrients Inorganic Phosphorus Compounds Inorganic Nitrogen Compounds... develop Spill Prevention Control and Countermeasure Plans and requirements to implement Best Management...

Improving the Carprofen Solubility: Synthesis of the Zn2Al-LDH Hybrid Compound.

Science.gov (United States)

Capsoni, Doretta; Quinzeni, Irene; Bruni, Giovanna; Friuli, Valeria; Maggi, Lauretta; Bini, Marcella

2018-01-01

The development of efficient strategies for drug delivery is considerably desired. Indeed, often several issues such as the drug solubility, the control of the drug release rate, the targeted delivery of drugs, the drug bioavailability, and the minimization of secondary effects still present great obstacles. Different methodologies have been proposed, but the use of nano-hybrids compounds that combine organic and inorganic substances seems particularly promising. An interesting inorganic host is the layered double hydroxide (LDH) with a sheets structure and formula [M 2+ 1-x M 3+ x (OH) 2 ](A n- ) x/n yH 2 O (M 2+  = Zn, Mg; M 3+  = Al; A n-  = nitrates, carbonates, chlorides). The possibility to exchange these counterions with drug molecules makes these systems ideal candidates for the drug delivery. In this article, we synthesize by co-precipitation method the hybrid compound Carprofen-Zn 2 Al-LDH. Carprofen, a poorly soluble anti-inflammatory drug, could also benefit of the association with a natural antacid such as LDH, to reduce the gastric irritation after its administration. Through X-ray diffraction and Fourier-transformed infrared spectroscopy (FT-IR), we could verify the effective drug intercalation into LDH. The dissolution tests clearly demonstrate a significant improvement of the drug release rate when carprofen is in the form of hybrid compound. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Soft templating strategies for the synthesis of mesoporous materials: inorganic, organic-inorganic hybrid and purely organic solids.

Science.gov (United States)

Pal, Nabanita; Bhaumik, Asim

2013-03-01

With the discovery of MCM-41 by Mobil researchers in 1992 the journey of the research on mesoporous materials started and in the 21st century this area of scientific investigation have extended into numerous branches, many of which contribute significantly in emerging areas like catalysis, energy, environment and biomedical research. As a consequence thousands of publications came out in large varieties of national and international journals. In this review, we have tried to summarize the published works on various synthetic pathways and formation mechanisms of different mesoporous materials viz. inorganic, organic-inorganic hybrid and purely organic solids via soft templating pathways. Generation of nanoscale porosity in a solid material usually requires participation of organic template (more specifically surfactants and their supramolecular assemblies) called structure-directing agent (SDA) in the bottom-up chemical reaction process. Different techniques employed for the syntheses of inorganic mesoporous solids, like silicas, metal doped silicas, transition and non-transition metal oxides, mixed oxides, metallophosphates, organic-inorganic hybrids as well as purely organic mesoporous materials like carbons, polymers etc. using surfactants are depicted schematically and elaborately in this paper. Moreover, some of the frontline applications of these mesoporous solids, which are directly related to their functionality, composition and surface properties are discussed at the appropriate places. Copyright © 2012 Elsevier B.V. All rights reserved.

Treatment with activated carbon and other adsorbents as an effective method for the removal of volatile compounds in agricultural distillates.

Science.gov (United States)

Balcerek, Maria; Pielech-Przybylska, Katarzyna; Patelski, Piotr; Dziekońska-Kubczak, Urszula; Jusel, Tomaš

2017-05-01

This study investigates the effect of treatment with activated carbon and other adsorbents on the chemical composition and organoleptics of a barley malt-based agricultural distillate. Contact with activated carbon is one of the methods by which the quality of raw distillates and spirit beverages can be improved. Samples placed in contact with 1 g activated carbon (SpiritFerm) per 100 ml distillate with ethanol content of 50% v/v for 1 h showed the largest reductions in the concentrations of most volatile compounds (aldehydes, alcohols, esters). Increasing the dose of adsorbent to over 1 g 100 ml -1 did not improve the purity of the agricultural distillate significantly. Of the tested compounds, acetaldehyde and methanol showed the lowest adsorption on activated carbon. The lowest concentrations of these congeners (expressed in mg l -1 alcohol 100% v/v) were measured in solutions with ethanol contents of 70-80% v/v, while solutions with an alcoholic strength by volume of 40% did not show statistically significant decreases in these compounds in relation the control sample. The reductions in volatile compounds were compared with those for other adsorbents based on silica or activated carbon and silica. An interesting alternative to activated carbon was found to be an adsorbent prepared from activated carbon and silica (Spiricol). Treatment with this adsorbent produced distillate with the lowest concentrations of acetaldehyde and isovaleraldehyde, and led to the greatest improvement in its organoleptics.

Quantification of Biogenic Volatile Organic Compounds with a Flame Ionization Detector Using the Effective Carbon Number Concept

Science.gov (United States)

Faiola, C. L.; Erickson, M. H.; Fricaud, V. L.; Wallace, H. W.; Jobson, B. T.; VanReken, T. M.

2011-12-01

Biogenic volatile organic compounds (BVOCs) are emitted into the atmosphere by plants and include structurally complex organic molecules such as monoterpenes, sesquiterpenes, and their oxygenated derivatives. These BVOCs are among the principle factors influencing the oxidative capacity of the atmosphere in forested regions. BVOC emission rates are often measured by collecting samples onto adsorptive cartridges in the field and then transporting these samples to the laboratory for chromatographic analysis. One of the most commonly used detectors in gas chromatography is the flame ionization detector (FID) due to its broad linear range, high sensitivity, and predictable response to many compounds. The FID response to saturated aliphatic molecules is proportional to carbon number. However, deviations occur as the complexity of the molecular structure increases. To account for these deviations, Sternberg et al. (1962) developed the effective carbon number (ECN) concept, which describes the number of carbons the FID "effectively" responds to. The ECN of a complex molecule can be estimated from the number and type of functional groups present, allowing an estimate of relative response factors for quantification. This approach is particularly useful for applications where samples contain a mixture of organic compounds and standards are not realistically accessible- a common predicament for environmental measurements. ECNs for a limited number of compounds with varying functional groups have been quantified in previous studies. However, there remain large gaps in the variety of compounds for which published data are available. This results in higher than necessary uncertainties when quantifying compounds that are structurally dissimilar to those that have been reported in the literature. The purpose of this study was to determine the ECN for a variety of terpenoid compounds to enable improved quantification of BVOC measurements. A dynamic dilution system was developed to

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.

Natural vegetation restoration is more beneficial to soil surface organic and inorganic carbon sequestration than tree plantation on the Loess Plateau of China.

Science.gov (United States)

Jin, Zhao; Dong, Yunshe; Wang, Yunqiang; Wei, Xiaorong; Wang, Yafeng; Cui, Buli; Zhou, Weijian

2014-07-01

Natural vegetation restoration and tree plantation are the two most important measures for ecosystem restoration on the Loess Plateau of China. However, few studies have compared the effects of the two contrasting measures on soil organic and inorganic carbon (SOC and SIC) sequestration or have further used SOC and SIC isotopes to analyze the inherent sequestration mechanism. This study examined a pair of neighboring small watersheds with similar topographical and geological backgrounds. Since 1954, natural vegetation restoration has been conducted in one of these watersheds, and tree plantation has been conducted in the other. The two watersheds have now formed completely different landscapes (naturally restored grassland and artificial forestland). Differences in soil bulk density, SOC and SIC content and storage, and SOC and SIC δ(13)C values were investigated in the two ecosystems in the upper 1m of the soil. We found that SOC storage was higher in the grassland than in the forestland, with a difference of 14.90 Mg ha(-1). The vertical changes in the δ(13)CSOC value demonstrated that the two ecosystems have different mechanisms of soil surface organic carbon accumulation. The SIC storage in the grassland was lower than that in the forestland, with a difference of 38.99 Mg ha(-1). The δ(13)CSIC values indicated that the grassland generates more secondary carbonate than the forestland and that SIC was most likely transported to the rivers from the grassland as dissolved inorganic carbon (DIC). The biogeochemical characteristics of the grassland were favorable for the formation of bicarbonate. Thus, more DIC derived from the dissolution of root and microbial respired CO2 into soil water could have been transported to the rivers through flood runoff. It is necessary to study further the transportation of DIC from the grassland because this process can produce a large potential carbon sink. Copyright © 2014. Published by Elsevier B.V.

Adsorption of selected pharmaceuticals and an endocrine disrupting compound by granular activated carbon. 2. Model prediction

Energy Technology Data Exchange (ETDEWEB)

Yu, Z.; Peldszus, S.; Huck, P.M. [University of Waterloo, Waterloo, ON (Canada). NSERC Chair in Water Treatment

2009-03-01

The adsorption of two representative pharmaceutically active compounds (PhACs) naproxen and carbamazepine and one endocrine disrupting compound (EDC) nonylphenol was studied in pilot-scale granular activated carbon (GAC) adsorbers using post-sedimentation (PS) water from a full-scale drinking water treatment plant. The GAC adsorbents were coal-based Calgon Filtrasorb 400 and coconut shell-based PICA CTIF TE. Acidic naproxen broke through fastest while nonylphenol was removed best, which was consistent with the degree to which fouling affected compound removals. Model predictions and experimental data were generally in good agreement for all three compounds, which demonstrated the effectiveness and robustness of the pore and surface diffusion model (PSDM) used in combination with the time-variable parameter approach for predicting removals at environmentally relevant concentrations (i.e., ng/L range). Sensitivity analyses suggested that accurate determination of film diffusion coefficients was critical for predicting breakthrough for naproxen and carbamazepine, in particular when high removals are targeted. Model simulations demonstrated that GAC carbon usage rates (CURs) for naproxen were substantially influenced by the empty bed contact time (EBCT) at the investigated conditions. Model-based comparisons between GAC CURs and minimum CURs for powdered activated carbon (PAC) applications suggested that PAC would be most appropriate for achieving 90% removal of naproxen, whereas GAC would be more suitable for nonylphenol. 25 refs., 4 figs., 1 tab.

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.

Effects of photoperiodism on the metabolism of carbon compounds and the migration of these products in tobacco

International Nuclear Information System (INIS)

Farineau, Jack

1961-01-01

This research thesis addressed the influence of photoperiodism on migrations. The author more particularly studied migrations of carbon-compound metabolism products by using a tobacco leaf in presence of "1"4CO_2, and which thus contained a high quantity of radioactive compounds. Some experiments were performed on short durations (few hours), and others on longer durations (15 days). As far as the first ones were concerned, the author studied the content of the petiole and of the terminal bud, and the first reactions of integration of carbon 14 compounds of the sap in the leaf. As far as the second type of experiments is concerned, the author measured the quantities of radioactive products migrating towards the terminal bud [fr

Fertilization increases paddy soil organic carbon density*

Science.gov (United States)

Wang, Shao-xian; Liang, Xin-qiang; Luo, Qi-xiang; Fan, Fang; Chen, Ying-xu; Li, Zu-zhang; Sun, Huo-xi; Dai, Tian-fang; Wan, Jun-nan; Li, Xiao-jun

2012-01-01

Field experiments provide an opportunity to study the effects of fertilization on soil organic carbon (SOC) sequestration. We sampled soils from a long-term (25 years) paddy experiment in subtropical China. The experiment included eight treatments: (1) check, (2) PK, (3) NP, (4) NK, (5) NPK, (6) 7F:3M (N, P, K inorganic fertilizers+30% organic N), (7) 5F:5M (N, P, K inorganic fertilizers+50% organic N), (8) 3F:7M (N, P, K inorganic fertilizers+70% organic N). Fertilization increased SOC content in the plow layers compared to the non-fertilized check treatment. The SOC density in the top 100 cm of soil ranged from 73.12 to 91.36 Mg/ha. The SOC densities of all fertilizer treatments were greater than that of the check. Those treatments that combined inorganic fertilizers and organic amendments had greater SOC densities than those receiving only inorganic fertilizers. The SOC density was closely correlated to the sum of the soil carbon converted from organic amendments and rice residues. Carbon sequestration in paddy soils could be achieved by balanced and combined fertilization. Fertilization combining both inorganic fertilizers and organic amendments is an effective sustainable practice to sequestrate SOC. PMID:22467369

Fertilization increases paddy soil organic carbon density.

Science.gov (United States)

Wang, Shao-xian; Liang, Xin-qiang; Luo, Qi-xiang; Fan, Fang; Chen, Ying-xu; Li, Zu-zhang; Sun, Huo-xi; Dai, Tian-fang; Wan, Jun-nan; Li, Xiao-jun

2012-04-01

Field experiments provide an opportunity to study the effects of fertilization on soil organic carbon (SOC) sequestration. We sampled soils from a long-term (25 years) paddy experiment in subtropical China. The experiment included eight treatments: (1) check, (2) PK, (3) NP, (4) NK, (5) NPK, (6) 7F:3M (N, P, K inorganic fertilizers+30% organic N), (7) 5F:5M (N, P, K inorganic fertilizers+50% organic N), (8) 3F:7M (N, P, K inorganic fertilizers+70% organic N). Fertilization increased SOC content in the plow layers compared to the non-fertilized check treatment. The SOC density in the top 100 cm of soil ranged from 73.12 to 91.36 Mg/ha. The SOC densities of all fertilizer treatments were greater than that of the check. Those treatments that combined inorganic fertilizers and organic amendments had greater SOC densities than those receiving only inorganic fertilizers. The SOC density was closely correlated to the sum of the soil carbon converted from organic amendments and rice residues. Carbon sequestration in paddy soils could be achieved by balanced and combined fertilization. Fertilization combining both inorganic fertilizers and organic amendments is an effective sustainable practice to sequestrate SOC.

Insight into π-hole interactions containing the inorganic heterocyclic compounds S2N2/SN2P2.

Science.gov (United States)

Lu, Bo; Zhang, Xueying; Meng, Lingpeng; Zeng, Yanli

2017-08-01

Similar to σ-hole interactions, the π-hole interaction has attracted much attention in recent years. According to the positive electrostatic potentials above and below the surface of inorganic heterocyclic compounds S 2 N 2 and three SN 2 P 2 isomers (heterocyclic compounds 1-4), and the negative electrostatic potential outside the X atom of XH 3 (X = N, P, As), S 2 N 2 /SN 2 P 2 ⋯XH 3 (X = N, P, As) complexes were constructed and optimized at the MP2/aug-cc-pVTZ level. The X atom of XH 3 (X = N, P, As) is almost perpendicular to the ring of the heterocyclic compounds. The π-hole interaction energy becomes greater as the trend goes from 1⋯XH 3 to 4⋯XH 3 . These π-hole interactions are weak and belong to "closed-shell" noncovalent interactions. According to the energy decomposition analysis, of the three attractive terms, the dispersion energy contributes more than the electrostatic energy. The polarization effect also plays an important role in the formation of π-hole complexes, with the contrasting phenomena of decreasing electronic density in the π-hole region and increasing electric density outside the X atom of XH 3 (X = N, P, As). Graphical abstract Computed density difference plots for the complexes 3⋯NH 3 (a 1 ), 3⋯PH 3 (b 1 ), 3⋯AsH 3 (c 1 ) and electron density shifts for the complexes 3⋯NH 3 (a 2 ), 3⋯PH 3 (b 2 ),3⋯AsH 3 (c 2 ) on the 0.001 a.u. contour.

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; da Silva, Juliana; 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; Ferraz, Alexandre B F; 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.

Carbon transfer in soil - plant system. Molecular labelling utilization for determining rhizosphere compounds

International Nuclear Information System (INIS)

Leguay, J.J.

2000-01-01

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.)

Cytotoxic effects of S-(dimethylarsino)-glutathione: A putative intermediate metabolite of inorganic arsenicals

International Nuclear Information System (INIS)

Hirano, Seishiro; Kobayashi, Yayoi

2006-01-01

Glutathione (GSH) plays an important role in the metabolism of arsenite and arsenate by generating arsenic-glutathione complexes. Although dimethylarsinic acid (DMA V ) is the major metabolite of inorganic arsenicals (iAs) in urine, it is not clear how DMA V is produced from iAs. In the present study we report that S-(dimethylarsino)-glutathione (DMA III (SG)), a putative precursor of dimethylarsinic acid DMA V , was unstable in the culture medium without excess GSH and generated volatile substances which were highly cytotoxic for both rat heart microvascular endothelial cells and HL60, a human leukemia cell line. Cytotoxicity of DMA III (SG) was higher than that of iAs and its LC 5 value was calculated to be 7.8 μM in the endothelial cells. To our surprise DMA III (SG) effectively killed cells in the neighbor wells of the same multi-well dish, indicating that volatile toxic compounds generated from DMA III (SG) in the culture medium. High performance lipid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICPMS) analyses suggested that the freshly generated volatile compounds dissolved into aqueous solution and formed an unstable arsenic compound and the unstable compound was further converted to DMA V . These results suggested that DMA III (SG) exerts its cytotoxicity by generating volatile arsenicals and is implicated in the metabolic conversion of inorganic arsenicals into DMA V , a major final metabolite of inorganic arsenicals in most mammals

Influence of aging on the retention of CH3131I by various empregnated activated carbons

International Nuclear Information System (INIS)

Deuber, H.

1986-08-01

Nuclear power plants are equipped with iodine filters containing impregnated activated carbons to keep the release of airborne radioiodine as low as reasonably achievable. Impregnated activated carbons are known to age, i.e. to deteriorate in performance with respect to the retention of radioiodine, particularly in iodine filters that are continuously operated (e.g. containment exhaust air filters of pressurized water reactors). The aging of carbons in iodine filters is essentially due to the adsorption of organic compounds (e.g. solvents) and of inorganic compounds (e.g. Osub(x), SO 2 , NOsub(x)). In the first case the effective surface of the carbon is lowered. In the second case reactions with carbon as well as with the impregnant can occur. In iodine filters various impregnated activated carbons are used differing e.g. in base material, grain size and impregnant. In recent years new impregnated activated carbons were developed. Therefore, investigations are performed to provide comparative data on the aging of a variety of commercial impregnated activated carbons from several countries under relevant conditions. The data relate to the retention of methyl iodide (CH 3 I-131). The investigations cover the aging of 15 different impregnated activated carbons in the containment exhaust air of a typical German pressurized water reactor over periods of up to 9 months

Adsorption of p-cresol on novel diatomite/carbon composites.

Science.gov (United States)

Hadjar, H; Hamdi, B; Ania, C O

2011-04-15

Hybrid inorganic/organic adsorbents were synthesized using mixtures of diatomite and carbon charcoal as precursors, and explored for the removal of p-cresol from aqueous solution. The carbon/diatomite composites displayed a bimodal and interconnected porous structure which was partially inherited from both precursors. They display moderate surface areas (between 100 and 400 m(2)g(-1)) due to their large inorganic content (between 70 and 90 wt.%), since the diatomite is a non-porous material. Compared to activated carbons with a more developed porosity, p-cresol adsorption on the prepared carbon/diatomite composites was much faster, showing adsorption capacities similar to those of conventional adsorbents over a wide pH range. These results show a good affinity of p-cresol molecules towards the hybrid inorganic/organic composites, and demonstrate the suitability of these novel materials for the removal of aromatic (polar) molecules, despite their dominant inorganic character. Copyright © 2011 Elsevier B.V. All rights reserved.

Effects of inorganic carbon on the nitrous oxide emissions and microbial diversity of an anaerobic ammonia oxidation reactor.

Science.gov (United States)

Zhang, Wenjie; Wang, Dunqiu; Jin, Yue

2018-02-01

Inorganic carbon (IC) is important for anaerobic ammonium oxidation (anammox). In this study, the effects of the IC concentration on N 2 O emissions and microbial diversity in an anammox reactor were investigated. N 2 O emissions were positively correlated with IC concentrations, and IC concentrations in the range of 55-130 mg/L were optimal, considering the nitrogen removal rate and N 2 O emissions. High IC concentrations resulted in the formation of CaCO 3 on the surface of anammox granules, which impacted the diffusion conditions of the substrate. Microbial community analysis indicated that high IC concentrations decreased the populations of specific bacteria, such as Achromobacter spanius strain YJART-7, Achromobacter xylosoxidans strain IHB B 6801, and Denitratisoma oestradiolicum clone 20b_15. D. oestradiolicum clone 20b_15 appeared to be the key contributor to N 2 O emissions. High N 2 O emissions may result from changes in organic carbon sources, which lead to denitrification by D. oestradiolicum clone 20b_15. Copyright © 2017 Elsevier Ltd. All rights reserved.

Creating a computer game suitable for practice of nomenclature of inorganic compounds

OpenAIRE

NEČEDA, Luboš

2017-01-01

This thesis is focused on usage of computer game (adventure game) in teaching of chemismy (posted on internet since 2017). Game is situated to the town of České Budějovice and contains set of tests from Inorganic chemisty. This game can be used to motivate students to study chemistry on primary schools.

Pyrolytic carbon coating for cytocompatibility of titanium oxide nanoparticles: a promising candidate for medical applications

International Nuclear Information System (INIS)

Behzadi, Shahed; Simchi, Abdolreza; Imani, Mohammad; Yousefi, Mohammad; Galinetto, Pietro; Amiri, Houshang; Stroeve, Pieter; Mahmoudi, Morteza

2012-01-01

Nanoparticles for biomedical use must be cytocompatible with the biological environment that they are exposed to. Current research has focused on the surface functionalization of nanoparticles by using proteins, polymers, thiols and other organic compounds. Here we show that inorganic nanoparticles such as titanium oxide can be coated by pyrolytic carbon (PyC) and that the coating has cytocompatible properties. Pyrolization and condensation of methane formed a thin layer of pyrolytic carbon on the titanium oxide core. The formation of the PyC shell retards coalescence and sintering of the ceramic phase. Our MTT assay shows that the PyC-coated particles are cytocompatible at employed doses. (paper)

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.

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.

Adsorption of aromatic compounds by carbonaceous adsorbents: a comparative study on granular activated carbon, activated carbon fiber, and carbon nanotubes.

Science.gov (United States)

Zhang, Shujuan; Shao, Ting; Kose, H Selcen; Karanfil, Tanju

2010-08-15

Adsorption of three aromatic organic compounds (AOCs) by four types of carbonaceous adsorbents [a granular activated carbon (HD4000), an activated carbon fiber (ACF10), two single-walled carbon nanotubes (SWNT, SWNT-HT), and a multiwalled carbon nanotube (MWNT)] with different structural characteristics but similar surface polarities was examined in aqueous solutions. Isotherm results demonstrated the importance of molecular sieving and micropore effects in the adsorption of AOCs by carbonaceous porous adsorbents. In the absence of the molecular sieving effect, a linear relationship was found between the adsorption capacities of AOCs and the surface areas of adsorbents, independent of the type of adsorbent. On the other hand, the pore volume occupancies of the adsorbents followed the order of ACF10 > HD4000 > SWNT > MWNT, indicating that the availability of adsorption site was related to the pore size distributions of the adsorbents. ACF10 and HD4000 with higher microporous volumes exhibited higher adsorption affinities to low molecular weight AOCs than SWNT and MWNT with higher mesopore and macropore volumes. Due to their larger pore sizes, SWNTs and MWNTs are expected to be more efficient in adsorption of large size molecules. Removal of surface oxygen-containing functional groups from the SWNT enhanced adsorption of AOCs.

Adsorption of triton X100 and potassium hydrogen phthalate on granular activated carbon from date pits

Energy Technology Data Exchange (ETDEWEB)

Merzougui, Z.; Nedjah, S.; Azoudj, Y.; Addoun, F. [Laboratoire d' etude physic-chimique des materiaux et application a l' environnement, Faculte de Chimie, USTHB (Algeria)], E-mail: zmerzougi@yahoo.fr

2011-07-01

Activated carbons, thanks to their versatility, are being used in the water treatment sector to absorb pollutants. Several factors influence the adsorption capacity of activated carbon and the aim of this study was to assess the effects of the porous texture and chemical nature of activated carbons on the adsorption of triton X100 and potassium hydrogen phthalate. Activated carbons used in this study were prepared from date pits with ZnCl2, KOH and H3PO4 by carbonization without adjuvant and adsorption of triton X100 and potassium hydrogen phthalate was conducted at 298K. Results showed that activated carbons prepared from date pits have a great potential for removing organic and inorganic pollutants from water and that the adsorption potential depends on the degree of activation of the activated carbons and on the compounds to absorb. This study highlighted that an increase of the carbon surface area and porosity results in a better adsorption capacity.

Interactions between radionuclides and organic colloids. Structure and reactivity of humic compounds; Interactions entre radionucleides et colloides organiques. Structure et reactivite des substances humiques

Energy Technology Data Exchange (ETDEWEB)

Plancque, G

2001-09-01

Humic compounds are the main organic colloids present in natural waters. These compounds can significantly modify the speciation of metals and control their properties, like migration, toxicity or bio-availability. It is thus important to study their speciation in conditions representative to those encountered in the natural environment. The aim of this work is to analyze the reactivity of these humic compounds. Two spectroscopic techniques have been used: the time-resolution laser spectro-fluorimetry, limited to the study of fluorescent elements, and the electro-spray source mass spectroscopy which requires the development of specific protocols for all elements of the periodic classification system. Europium, a fluorescent element analogue to trivalent actinides, has been chosen as test-metal for the intercomparison of both spectroscopic techniques. The first technique has permitted to determine the inorganic and organic speciation (spectra and lifetime of europium hydroxides and carbonates, and constants of interaction with humic acids, respectively). The limitations of this technique in the study of inorganic speciation has been evidenced. Humic compounds have a badly defined structure. The use of high-resolution mass spectroscopy has permitted to propose in a direct and experimental way, a molecular structure of aquatic fulvic acids in agreement with their known physico-chemical properties. (J.S.)

Effect of carbon black composition with sludge palm oil on the curing characteristic and mechanical properties of natural rubber/styrene butadiene rubber compound

Science.gov (United States)

Mohamed, R.; Nurazzi, N. Mohd; Huzaifah, M.

2017-07-01

This study was conducted to investigate the possibility of utilizing sludge palm oil (SPO) as processing oil, with various amount of carbon black as its reinforcing filler, and its effects on the curing characteristics and mechanical properties of natural rubber/styrene butadiene rubber (NR/SBR) compound. Rubber compound with fixed 15 pphr of SPO loading, and different carbon black loading from 20 to 50 pphr, was prepared using two roll mills. The cure characteristics and mechanical tests that have been conducted are the scorch and cure time analysis, tensile strength and tear strength. Scorch time (ts5) and cure time (t90) of the compound increases with the increasing carbon black loading. The mechanical properties of NR/SBR compound viz. the tensile strength, modulus at 300% strain and tear strength were also improved by the increasing carbon black loading.

Isotope dilution mass spectrometry of inorganic and organic substances

International Nuclear Information System (INIS)

Heumann, K.G.

1986-01-01

The aim of this short review of IDMS is to provide an introduction into the principles of this analytical method and to show possible applications of this accurate technique, e.g. negative thermal ionization IDMS for inorganic anion analysis or the analysis of organic compounds in the field of clinical chemistry. (orig./RB)

Biogeochemical generation of dissolved inorganic carbon and nitrogen in the North Branch of inner Changjiang Estuary in a dry season

Science.gov (United States)

Zhai, Wei-Dong; Yan, Xiu-Li; Qi, Di

2017-10-01

We investigated the surface water carbonate system, nutrients, and relevant hydrochemical parameters in the inner Changjiang (Yangtze River) Estuary in early spring 2009 and 2010. The two surveys were carried out shortly after spring-tide days, and covered both the channel-like South Branch and the freshwater-blocked North Branch. In the North Branch, with a water residence time of approximately one month, we detected remarkable partial pressures of CO2 (pCO2) of 930-1518 μatm with a salinity range of 4.5-17.4, which were substantially higher than the South Branch pCO2 values of 700-1100 μatm at salinities of less than 0.88. The North Branch pCO2 distribution pattern is unique compared with many other estuaries where aquatic pCO2 normally declines with salinity increase. Furthermore, the biogeochemical additions of ammonium (7.4-65.7 μmol kg-1) and alkalinity (196-695 μmol kg-1) were identified in salinities between 4 and 16 in the North Branch. Based on field data analyses and simplified stoichiometric equations, we suggest that the relatively high North Branch pCO2 values and estuarine additions of dissolved inorganic nitrogen/carbon in the mid-salinity area were strongly associated with each other. These signals were primarily controlled by biogeochemical processes in the North Branch, combining biogenic organic matter decomposition (i.e. respiration), ammonia oxidation, CaCO3 dissolution, and CO2 degassing. In the upper reach of the South Branch, notable salinity values of 0.20-0.88 were detected, indicating saltwater spillover from the North Branch. These spillover waters had minor contributions (1.5-6.9%) to the springtime nutrient, dissolved inorganic carbon, and alkalinity export fluxes from Changjiang to the adjacent East China Sea. This is the first attempt to understand the biogeochemical controls of the unique pCO2 distributions in the North Branch, and to evaluate the effects of saltwater spillover from the North Branch on dry-season export fluxes

Arsenic (+3 oxidation state) methyltransferase and the inorganic arsenic methylation phenotype

International Nuclear Information System (INIS)

Li Jiaxin; Waters, Stephen B.; Drobna, Zuzana; Devesa, Vicenta; Styblo, Miroslav; Thomas, David J.

2005-01-01

Inorganic arsenic is enzymatically methylated; hence, its ingestion results in exposure to the parent compound and various methylated arsenicals. Both experimental and epidemiological evidences suggest that some of the adverse health effects associated with chronic exposure to inorganic arsenic may be mediated by these methylated metabolites. If i As methylation is an activation process, then the phenotype for inorganic arsenic methylation may determine risk associated with exposure to this metalloid. We examined inorganic arsenic methylation phenotypes and arsenic (+3 oxidation state) methyltransferase genotypes in four species: three that methylate inorganic arsenic (human (Homo sapiens), rat (Rattus norwegicus), and mouse (Mus musculus)) and one that does not methylate inorganic arsenic (chimpanzee, Pan troglodytes). The predicted protein products from arsenic (+3 oxidation state) methyltransferase are similar in size for rat (369 amino acid residues), mouse (376 residues), and human (375 residues). By comparison, a 275-nucleotide deletion beginning at nucleotide 612 in the chimpanzee gene sequence causes a frameshift that leads to a nonsense mutation for a premature stop codon after amino acid 205. The null phenotype for inorganic arsenic methylation in the chimpanzee is likely due to the deletion in the gene for arsenic (+3 oxidation state) methyltransferase that yields an inactive truncated protein. This lineage-specific loss of function caused by the deletion event must have occurred in the Pan lineage after Homo-Pan divergence about 5 million years ago

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.

Carbonate counter pump stimulated by natural iron fertilization in the Polar Frontal Zone

Science.gov (United States)

Salter, Ian; Schiebel, Ralf; Ziveri, Patrizia; Movellan, Aurore; Lampitt, Richard; Wolff, George A.

2014-12-01

The production of organic carbon in the ocean's surface and its subsequent downward export transfers carbon dioxide to the deep ocean. This CO2 drawdown is countered by the biological precipitation of carbonate, followed by sinking of particulate inorganic carbon, which is a source of carbon dioxide to the surface ocean, and hence the atmosphere over 100-1,000 year timescales. The net transfer of CO2 to the deep ocean is therefore dependent on the relative amount of organic and inorganic carbon in sinking particles. In the Southern Ocean, iron fertilization has been shown to increase the export of organic carbon, but it is unclear to what degree this effect is compensated by the export of inorganic carbon. Here we assess the composition of sinking particles collected from sediment traps located in the Polar Frontal Zone of the Southern Ocean. We find that in high-nutrient, low-chlorophyll regions that are characterized by naturally high iron concentrations, fluxes of both organic and inorganic carbon are higher than in regions with no iron fertilization. However, the excess flux of inorganic carbon is greater than that of organic carbon. We estimate that the production and flux of carbonate in naturally iron-fertilized waters reduces the overall amount of CO2 transferred to the deep ocean by 6-32%, compared to 1-4% at the non-fertilized site. We suggest that an increased export of organic carbon, stimulated by iron availability in the glacial sub-Antarctic oceans, may have been accompanied by a strengthened carbonate counter pump.

The First Organic-Inorganic Hybrid Luminescent Multiferroic: (Pyrrolidinium)MnBr3.

Science.gov (United States)

Zhang, Yi; Liao, Wei-Qiang; Fu, Da-Wei; Ye, Heng-Yun; Liu, Cai-Ming; Chen, Zhong-Ning; Xiong, Ren-Gen

2015-07-08

A hybrid organic-inorganic compound, (pyrrolidinium)MnBr3 , distinguished from rare earth (RE)-doped inorganic perovskites, is discovered as a new member of the ferroelectrics family, having excellent luminescent properties and relatively large spontaneous polarization of 6 μC cm(-2) , as well as a weak ferromagnetism at about 2.4 K. With a quantum yield of >28% and emission lifetime >0.1 ms, such multiferroic photoluminescence is a suitable candidate for future applications in luminescence materials, photovoltaics, and magneto-optoelectronic devices. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Elaboration, structural, vibrational and optical investigation of a two-dimensional self-assembled organic–inorganic hybrid compound

International Nuclear Information System (INIS)

Dammak, T.; Boughzala, H.; Mlayah, A.; Abid, Y.

2016-01-01

Single crystals of a hybrid organic/inorganic material with the formula (C 4 N 3 H 16 )Cl[CuCl 4 ] were elaborated and studied by X-ray diffraction, and photoluminescence. The crystals consist of a self-assembled multilayer structure with a Pnam space group. The structure is built up from the staking of infinite two-dimensional layers of CuCl 6 corner-sharing octahedra, separated by organic (C 4 N 3 H 16 ) 3+ chains. Such a structure may be regarded as a multi quantum well system, in which CuCl 6 layers act as semiconductor wells and the organic molecules act as insulator barriers Furthermore, the room temperature IR and Raman spectra of the title compound were recorded and analyzed. For optical investigations, thin films have been prepared by spin-coating method from the ethanol solution of the material. Optical absorption spectra shows characteristic absorptions of CuCl-based layered perovskite centered at 300 and 380 nm, whereas the photoluminescence spectra shows a bleu intense emission around 420 nm, associated to radiative recombination of confined excitons in the CuCl 6 Quantum wells.

Photocatalytic hydrogen evolution from aqueous solutions of organophosphorous compounds

Energy Technology Data Exchange (ETDEWEB)

Kozlova, Ekaterina A.; Vorontsov, Alexander V. [Boreskov Institute of Catalysis and Novosibirsk State University, Novosibirsk 630090 (Russian Federation)

2010-07-15

Photocatalytic hydrogen production from water solutions of dimethyl methylphosphonate (DMMP), trimethyl phosphate (TMP), triethyl phosphate (TEP), and radiation protective amine WR 2721, that imitate nerve chemical warfare agents was studied for the first time. Platinized titianium dioxide Degussa P25 was used as catalyst. No significant hydrogen evolution was detected without organic electron donors - sacrificial agents. The hydrogen evolution rate was shown to grow slowly with the rise of initial DMMP concentration. The initial rate vs. DMMP concentration curve is well fitted by Langmuir-Hinshelwood (L-H) equation. The DMMP adsorption constant obtained from the L-H equation fit is markedly higher than that obtained from the Langmuir adsorption isotherm. Reactions of full destruction into inorganic products of the four organophosphorous compounds were conducted. Amounts of evolved hydrogen and carbon dioxide were completely consistent with stoichiometry of proposed reaction. There were no initial compounds and only trace of total organic carbon after the end of the reaction. Complete water purification and production of an amount of valuable hydrogen was achieved. Intermediates of DMMP oxygen-free destruction were identified by means of GC/MS. They were the same as those in the case of DMMP photocatalytic oxidation. A mechanism of hydrogen evolution that explains smaller rates of mineralization compared to photocatalytic oxidation by oxygen was proposed. (author)

Experimental formation enthalpies for intermetallic phases and other inorganic compounds

Science.gov (United States)

Kim, George; Meschel, S. V.; Nash, Philip; Chen, Wei

2017-01-01

The standard enthalpy of formation of a compound is the energy associated with the reaction to form the compound from its component elements. The standard enthalpy of formation is a fundamental thermodynamic property that determines its phase stability, which can be coupled with other thermodynamic data to calculate phase diagrams. Calorimetry provides the only direct method by which the standard enthalpy of formation is experimentally measured. However, the measurement is often a time and energy intensive process. We present a dataset of enthalpies of formation measured by high-temperature calorimetry. The phases measured in this dataset include intermetallic compounds with transition metal and rare-earth elements, metal borides, metal carbides, and metallic silicides. These measurements were collected from over 50 years of calorimetric experiments. The dataset contains 1,276 entries on experimental enthalpy of formation values and structural information. Most of the entries are for binary compounds but ternary and quaternary compounds are being added as they become available. The dataset also contains predictions of enthalpy of formation from first-principles calculations for comparison. PMID:29064466

The effect of carbonate on neptunium sorption by hydroxyapatite

International Nuclear Information System (INIS)

Moore, R.C.; Holt, K.

2005-01-01

Full text of publication follows: Hydroxyapatite, Ca 10 (PO 4 ) 6 (OH) 2 , is a common mineral, the main inorganic compound in bone and exhibits strong sorptive properties for many radionuclides. It has been widely studied and proposed as a backfill material for nuclear waste repositories. Neptunium is one the radionuclides sorbed by hydroxyapatite. Neptunium is of particular importance to nuclear waste repository performance because of its relatively high aqueous solubility, high mobility in the environment and long half-life. In this work, we report on the effects of carbonate on sorption of neptunium by hydroxyapatite. Batch sorption and desorption studies for neptunium were performed as a function of carbonate concentration in water using a synthetic hydroxyapatite. The results indicate even low concentrations of carbonate significantly reduce neptunium sorption and enhance desorption. The data were fit to several simple isotherm equations with the Langmuir equation giving the best results. The results of the work are discussed with respect to nuclear waste repository performance. (authors)

Variability in carbon isotope fractionation of trichloroethene during degradation by persulfate activated with zero-valent iron: Effects of inorganic anions

Energy Technology Data Exchange (ETDEWEB)

Liu, Yunde [State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074 (China); School of Environmental Studies, China University of Geosciences, Wuhan 430074 (China); Zhou, Aiguo, E-mail: aiguozhou@cug.edu.cn [State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074 (China); School of Environmental Studies, China University of Geosciences, Wuhan 430074 (China); Gan, Yiqun; Li, Xiaoqian [State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074 (China); School of Environmental Studies, China University of Geosciences, Wuhan 430074 (China)

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 (SO{sub 4}·{sup −}). 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). - Highlights: • Significant C isotope fractionation for TCE degradation by Fe{sup 0} activated persulfate. • The enrichment factors was independent of Fe{sup 0}, SO{sub 4}{sup 2−}, or HCO{sub 3}{sup −} concentration. • Cl{sup −} significantly influenced the carbon isotope fractionation.

Variability in carbon isotope fractionation of trichloroethene during degradation by persulfate activated with zero-valent iron: Effects of inorganic anions

International Nuclear Information System (INIS)

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

2016-01-01

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 (SO_4·"−). 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). - Highlights: • Significant C isotope fractionation for TCE degradation by Fe"0 activated persulfate. • The enrichment factors was independent of Fe"0, SO_4"2"−, or HCO_3"− concentration. • Cl"− significantly influenced the carbon isotope fractionation.

[Impact of Rocky Desertification Treatment on Underground Water Chemistry and Dissolved Inorganic Carbon Isotope in Karst Areas].

Science.gov (United States)

Xiao, Shi-zhen; Xiong, Kang-ning; Lan, Jia-cheng; Zhang, Hui; Yang, Long

2015-05-01

Five springs representing different land-use types and different karst rocky desertification treatment models were chosen at the Huajiang Karst Rocky Desertification Treatment Demonstration Site in Guanling-Zhenfeng Counties in Guizhou, to analyze the features of underground water chemistry and dissolved inorganic carbon isotopes (δ13C(DIC)) and reveal the effect of rocky desertification treatment on karstification and water quality. It was found that, the underground water type of the research area was HCO3-Ca; the water quality of the springs which were relatively less affected by human activities including Shuijingwan Spring (SJW) , Gebei Spring (GB), and Maojiawan Spring (MJW) was better than those relatively more affected by human activities including Diaojing Spring (DJ) and Tanjiazhai Spring (TJZ) , the main ion concentrations and electrical conductivity of which were higher; pH, SIc and pCO2 were sensitive to land-use types and rocky desertification treatment, which could be shown by the higher pH and SIc and lower pCO2 in MJW than those in the other four springs; (Ca(2+) + Mg2+)/HCO(3-) of SJW, MJW and GB were nearly 1:1, dominated by carbonate rock weathering by carbon acid, while the (Ca(2+) + Mg2+) of DJ and TJZ was much higher than HCO3-, suggesting that sulfate and nitrate might also dissolve carbonate rock because of the agricultural activities; δ13C(DIC) was lighter in wet season because of the higher biological activities; the average δ13C(DIC) was in the order of DJ (-12.79 per thousand) desertification and lighter after the rocky desertification are treated and controlled.

Advanced inorganic fluorides. Proceedings of the Second International Siberian workshop INTERSIBFLUORINE-2006

International Nuclear Information System (INIS)

Volkov, V.V.; Mit'kin, V.N.; Bujnovskij, A.S.; Sofronov, V.L.

2006-01-01

Proceedings of the Second International Siberian workshop ISIF-2006 on modern inorganic fluorides contain full author's texts of 82 plenary reports and posters on the main trends in chemistry and technology of inorganic fluorides and their various applications. The following new trends are reflected in the ISIF-2006 Proceedings versus the ISIF-2003 ones: production and use of of nano-sized systems and materials based on fluoride phases and fluorinating systems; chemistry of fluorofullerenes, fluorides of graphite and carbon materials; development of research and technical principles of economically viable process of depleted uranium hexafluoride conversion; vitrifying systems based on metal fluorides possessing valuable functional optical properties; mechanochemical processes and phenomena in chemistry of inorganic fluorides [ru

Preparation and characterization of a layered perovskite-type organic-inorganic hybrid compound (C8NH6-CH2CH2NH3)2CuCl4

International Nuclear Information System (INIS)

Zheng Yingying; Wu Gang; Deng Meng; Chen Hongzheng; Wang Mang; Tang, B.-Z.

2006-01-01

The organic-inorganic hybrid compound (C 8 NH 6 -CH 2 CH 2 NH 3 ) 2 CuCl 4 (AEI-CuCl 4 ) was synthesized from ethanol solution containing copper chloride and 3-2-(aminoethyl) indole hydrochloride (AEI-HCl). High order diffraction peaks corresponding to (0 0 l; l = 2, 4, 6, ...) observed in the X-ray diffraction profile of AEI-CuCl 4 indicated the formation of hybrid crystal with layered perovskite structure. The organic-inorganic hybrid crystal thin film can be easily prepared by spin-coating method from the ethanol solution of the AEI-CuCl 4 perovskite and it showed characteristic absorptions of CuCl-based layered perovskite centered at 288 and 388 nm, as well as the photoluminescence peak at around 420 nm. The unaided-eye-detectable blue fluorescence emission comes from the cooperation of AEI-HCl and AEI-CuCl 4 perovskite, in which protonized aminoethyl indole dominates the shape of the spectrum and the enhancement of emission intensity is due to the formation of the perovskite structure. The thermal analysis presented that the AEI-CuCl 4 perovskite started to melt at 182 deg. C, together with the beginning of the decomposition of the hybrids. Compared with the organic-inorganic perovskite hybrids reported previously, the AEI-CuCl 4 perovskite shows a novel stepwise decomposition behavior

The role of inorganic phosphate in intact human erythrocytes

International Nuclear Information System (INIS)

Nishiguchi, Eiko; Umeda, Masahiro.

1988-01-01

The role of inorganic phosphate in intact human erythrocytes was investigated by phosphorus-31 nuclear magnetic resonance ( 31 P NMR). When erythrocytes stored for 5 weeks were incubated at 37 deg C, pH 7.4, in medium containing 2 mM adenine and 10 mM inosine, with or without 5 mM glucose, a substance of around 4 ppm, as assessed by 31 P NMR chemical shift, was detected in the mixture. However, this substance disappeared by the addition of inorganic phosphate. When erythrocytes stored for 4 weeks in acid citrate dextrose (ACD) solution were incubated with 2 mM adenine, 10 mM inosine, 5 mM glucose, 50 mM inorganic phosphate and 10 mM pyruvate at 37 deg C, pH 7.4, the 2,3-DPG level increased gradually, whereas the ATP level initially increased and then decreased. Intracellular inorganic phosphate appeared to be used for the synthesis of ATP and 2,3-DPG during the first 30 min. of the reaction. These results suggests that the inorganic phosphate accelerates glycolysis by increasing the activity of glycolytic enzymes rather than its direct involvement in synthesizing organic phosphorus compounds in stored erythrocytes. The results also suggests that the reserve energy from ATP synthesis is not sufficient for the synthesis of 2,3-DPG. (author)

The mitigating effect of calcification-dependent of utilization of inorganic carbon of Chara vulgaris Linn on NH4-N toxicity.

Science.gov (United States)

Wang, Heyun; Ni, Leyi; Xie, Ping

2013-09-01

Increased ammonium (NH4-N) concentrations in water bodies have been reported to adversely affect the dominant species of submersed vegetation in meso-eutrophic waters worldwide. However calcareous plants were lowly sensitive to NH4-N toxicity. In order to make clear the function of calcification in the tolerance of calcareous plants to NH4-N stress, we studied the effects of increased HCO3(-) and additional NH4-N on calcification and utilization of dissolve inorganic carbon (DIC) in Chara vulgaris Linn in a 7-d sub-acute experiment (light:dark 12:12h) carried out in an open experimental system in lab. Results revealed that calcification was dependent of utilization of dissolve inorganic carbon. Additional HCO3(-) significantly decreased the increase of pH while additional NH4-N did not. And additional HCO3(-) significantly improved calcification while NH4-N did in versus in relation to the variation of DIC concentration. However, addition of both HCO3(-) and NH4-N increased utilization of DIC. This resulted in calcification to utilization of DIC ratio decreased under additional NH4-N condition while increased under additional HCO3(-) conditions in response to the variation of solution pH. In the present study, external HCO3(-) decreased the increase of solution pH by increasing calcification, which correspondingly mitigated the toxic effect of high NH4-N. And we argue that the mitigating effect of increased HCO3(-) on NH4-N toxicity is dependent of plant calcification, and it is a positive feedback mechanism, potentially leading to the dominance of calcareous plants in meso-eutrophic water bodies. Copyright © 2013 Elsevier Ltd. All rights reserved.

Evaluation of sampling methods for measuring exposure to volatile inorganic acids in workplace air. Part 2: Sampling capacity and breakthrough tests for sodium carbonate-impregnated filters.

Science.gov (United States)

Demange, Martine; Oury, Véronique; Rousset, Davy

2011-11-01

In France, the MétroPol 009 method used to measure workplace exposure to inorganic acids, such as HF, HCl, and HNO3, consists of a closed-face cassette fitted with a prefilter to collect particles, and two sodium carbonate-impregnated filters to collect acid vapor. This method was compared with other European methods during the development of a three-part standard (ISO 21438) on the determination of inorganic acids in workplace air by ion chromatography. Results of this work, presented in a companion paper, led to a need to go deeper into the performance of the MétroPol 009 method regarding evaluation of the breakthrough of the acids, both alone and in mixtures, interference from particulate salts, the amount of sodium carbonate required to impregnate the sampling filter, the influence of sampler components, and so on. Results enabled improvements to be made to the sampling device with respect to the required amount of sodium carbonate to sample high HCl or HNO3 concentrations (500 μL of 5% Na2CO3 on each of two impregnated filters). In addition, a PVC-A filter used as a prefilter in a sampling device showed a propensity to retain HNO3 vapor so a PTFE filter was considered more suitable for use as a prefilter. Neither the material of the sampling cassette (polystyrene or polypropylene) nor the sampling flowrate (1 L/min or 2 L/min) influenced the performance of the sampling device, as a recovery of about 100% was achieved in all experiments for HNO3, HCl, and HF, as well as HNO3+HF and HNO3+HCl mixtures, over a wide range of concentrations. However, this work points to the possibility of interference between an acid and salts of other acids. For instance, interference can occur through interaction of HNO3 with chloride salts: the stronger the acid, the greater the interference. Methods based on impregnated filters are reliable for quantitative recovery of inorganic volatile acids in workplace atmosphere but are valuable only in the absence of interferents.

Latest Permian carbonate carbon isotope variability traces heterogeneous organic carbon accumulation and authigenic carbonate formation

Science.gov (United States)

Schobben, Martin; van de Velde, Sebastiaan; Gliwa, Jana; Leda, Lucyna; Korn, Dieter; Struck, Ulrich; Vinzenz Ullmann, Clemens; Hairapetian, Vachik; Ghaderi, Abbas; Korte, Christoph; Newton, Robert J.; Poulton, Simon W.; Wignall, Paul B.

2017-11-01

Bulk-carbonate carbon isotope ratios are a widely applied proxy for investigating the ancient biogeochemical carbon cycle. Temporal carbon isotope trends serve as a prime stratigraphic tool, with the inherent assumption that bulk micritic carbonate rock is a faithful geochemical recorder of the isotopic composition of seawater dissolved inorganic carbon. However, bulk-carbonate rock is also prone to incorporate diagenetic signals. The aim of the present study is to disentangle primary trends from diagenetic signals in carbon isotope records which traverse the Permian-Triassic boundary in the marine carbonate-bearing sequences of Iran and South China. By pooling newly produced and published carbon isotope data, we confirm that a global first-order trend towards depleted values exists. However, a large amount of scatter is superimposed on this geochemical record. In addition, we observe a temporal trend in the amplitude of this residual δ13C variability, which is reproducible for the two studied regions. We suggest that (sub-)sea-floor microbial communities and their control on calcite nucleation and ambient porewater dissolved inorganic carbon δ13C pose a viable mechanism to induce bulk-rock δ13C variability. Numerical model calculations highlight that early diagenetic carbonate rock stabilization and linked carbon isotope alteration can be controlled by organic matter supply and subsequent microbial remineralization. A major biotic decline among Late Permian bottom-dwelling organisms facilitated a spatial increase in heterogeneous organic carbon accumulation. Combined with low marine sulfate, this resulted in varying degrees of carbon isotope overprinting. A simulated time series suggests that a 50 % increase in the spatial scatter of organic carbon relative to the average, in addition to an imposed increase in the likelihood of sampling cements formed by microbial calcite nucleation to 1 out of 10 samples, is sufficient to induce the observed signal of carbon

Latest Permian carbonate carbon isotope variability traces heterogeneous organic carbon accumulation and authigenic carbonate formation

Directory of Open Access Journals (Sweden)

M. Schobben

2017-11-01

Full Text Available Bulk-carbonate carbon isotope ratios are a widely applied proxy for investigating the ancient biogeochemical carbon cycle. Temporal carbon isotope trends serve as a prime stratigraphic tool, with the inherent assumption that bulk micritic carbonate rock is a faithful geochemical recorder of the isotopic composition of seawater dissolved inorganic carbon. However, bulk-carbonate rock is also prone to incorporate diagenetic signals. The aim of the present study is to disentangle primary trends from diagenetic signals in carbon isotope records which traverse the Permian–Triassic boundary in the marine carbonate-bearing sequences of Iran and South China. By pooling newly produced and published carbon isotope data, we confirm that a global first-order trend towards depleted values exists. However, a large amount of scatter is superimposed on this geochemical record. In addition, we observe a temporal trend in the amplitude of this residual δ13C variability, which is reproducible for the two studied regions. We suggest that (sub-sea-floor microbial communities and their control on calcite nucleation and ambient porewater dissolved inorganic carbon δ13C pose a viable mechanism to induce bulk-rock δ13C variability. Numerical model calculations highlight that early diagenetic carbonate rock stabilization and linked carbon isotope alteration can be controlled by organic matter supply and subsequent microbial remineralization. A major biotic decline among Late Permian bottom-dwelling organisms facilitated a spatial increase in heterogeneous organic carbon accumulation. Combined with low marine sulfate, this resulted in varying degrees of carbon isotope overprinting. A simulated time series suggests that a 50 % increase in the spatial scatter of organic carbon relative to the average, in addition to an imposed increase in the likelihood of sampling cements formed by microbial calcite nucleation to 1 out of 10 samples, is sufficient to induce the

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

Directory of Open Access Journals (Sweden)

Luiz Carlos S. Porto

2016-01-01

Full Text Available 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.

Hybrid protein-inorganic nanoparticles: From tumor-targeted drug delivery to cancer imaging.

Science.gov (United States)

Elzoghby, Ahmed O; Hemasa, Ayman L; Freag, May S

2016-12-10

Recently, a great interest has been paid to the development of hybrid protein-inorganic nanoparticles (NPs) for drug delivery and cancer diagnostics in order to combine the merits of both inorganic and protein nanocarriers. This review primarily discusses the most outstanding advances in the applications of the hybrids of naturally-occurring proteins with iron oxide, gadolinium, gold, silica, calcium phosphate NPs, carbon nanotubes, and quantum dots in drug delivery and cancer imaging. Various strategies that have been utilized for the preparation of protein-functionalized inorganic NPs and the mechanisms involved in the drug loading process are discussed. How can the protein functionalization overcome the limitations of colloidal stability, poor dispersibility and toxicity associated with inorganic NPs is also investigated. Moreover, issues relating to the influence of protein hybridization on the cellular uptake, tumor targeting efficiency, systemic circulation, mucosal penetration and skin permeation of inorganic NPs are highlighted. A special emphasis is devoted to the novel approaches utilizing the protein-inorganic nanohybrids in combined cancer therapy, tumor imaging, and theranostic applications as well as stimuli-responsive drug release from the nanohybrids. Copyright © 2016 Elsevier B.V. All rights reserved.

Carbon-14 radiolabelling and tissue distribution evaluation of a potential anti-TB compound.

Science.gov (United States)

Sonopo, Molahlehi S; Venter, Kobus; Winks, Susan; Marjanovic-Painter, Biljana; Morgans, Garreth L; Zeevaart, Jan R

2016-06-15

This paper describes a five-step synthesis of a carbon-14-labelled pyrazole compound (11). A total of 2.96 MBq of 11 was obtained with the specific activity of 2242.4 MBq/mmol. The radiochemical purity was >99%, and the overall radiochemical yield was 60% based on the [(14) C6 ] 4-bromoaniline starting material. Biodistribution results showed that the radiotracer (administrated orally) has a high accumulation in the small intestine, large intestine and liver of both non-infected and tuberculosis (TB)-infected mice. Therefore, this suggests that compound 11 undergoes hepatobiliary clearance. The compound under investigation has been found to be slowly released from the liver between 2 and 8 h. The study revealed that 11 has no affinity for TB cells. Copyright © 2016 John Wiley & Sons, Ltd.

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.

[Study on the content and carbon isotopic composition of water dissolved inorganic carbon from rivers around Xi'an City].

Science.gov (United States)

Guo, Wei; Li, Xiang-Zhong; Liu, Wei-Guo

2013-04-01

In this study, the content and isotopic compositions of water dissolved inorganic carbon (DIC) from four typical rivers (Chanhe, Bahe, Laohe and Heihe) around Xi'an City were studied to trace the possible sources of DIC. The results of this study showed that the content of DIC in the four rivers varied from 0.34 to 5.66 mmol x L(-1) with an average value of 1.23 mmol x L(-1). In general, the content of DIC increased from the headstream to the river mouth. The delta13C(DIC) of four rivers ranged from -13.3 per thousand to -7.2 per thousand, with an average value of -10.1 per thousand. The delta13C(DIC) values of river water were all negative (average value of -12.6 per thousand) at the headstream of four rivers, but the delta13C(DIC) values of downstream water were more positive (with an average value of -9.4 per thousand). In addition, delta13C(DIC) of river water showed relatively negative values (the average value of delta13C(DIC) was -10.5 per thousand) near the estuary of the rivers. The variation of the DIC content and its carbon isotope suggested that the DIC sources of the rivers varied from the headstream to the river mouth. The negative delta13C(DIC) value indicated that the DIC may originate from the soil CO2 at the headstream of the rivers. On the other hand, the delta13C(DIC) values of river water at the middle and lower reaches of rivers were more positive, and it showed that soil CO2 produced by respiration of the C4 plants (like corn) and soil carbonates with positive delta13C values may be imported into river water. Meanwhile, the input of pollutants with low delta13C(DIC) values may result in a decrease of delta13C(DIC) values in the rivers. The study indicated that the DIC content and carbon isotope may be used to trace the sources of DIC in rivers around Xi'an City. Our study may provide some basic information for tracing the sources of DIC of rivers in the small watershed area in the Loess Plateau of China.

A novel speciation alternative for the determination of inorganic arsenic in marine samples

DEFF Research Database (Denmark)

Rasmussen, Rie Romme; Hedegaard, Rikke Susanne Vingborg; Herbst, M. Birgitte Koch

Arsenic (As) is bioaccumulated from seawater to concentrations in the mg/kg range in marine animals. More than 50 naturally-occurring arsenic containing species, both inorganic and organic forms, have been identified in marine animals. The organic forms are mainly considered to be non......-toxic, whereas inorganic arsenic is highly toxic and exposure may lead to severe adverse effects including cancer. Since seafood is the major dietary source for arsenic exposure in the European population, arsenic speciation analysis of marine samples is highly relevant for food safety. However, most data...... of inorganic arsenic in marine based food is based on microwave extraction, species separation by strong anion solid phase extraction (SPE) and hydride generation atomic absorption spectrometry (HG-AAS) detection. Separation organic arsenic compounds (e.g. MA, DMA and AB) and inorganic arsenic in the form...

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

International Nuclear Information System (INIS)

Saiful Irwan Zubairi; Nurul Shahreda Jaies

2014-01-01

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

Insights into the attenuated sorption of organic compounds on black carbon aged in soil.

Science.gov (United States)

Luo, Lei; Lv, Jitao; Chen, Zien; Huang, Rixiang; Zhang, Shuzhen

2017-12-01

Sorption of organic compounds on fresh black carbons (BCs) can be greatly attenuated in soil over time. We examined herein the changes in surface properties of maize straw-derived BCs (biochars) after aged in a black soil and their effects on the sorptive behaviors of naphthalene, phenanthrene and 1,3-dinitrobenzene. Dissolved fulvic and humic acids extracted from the soil were used to explore the role of dissolved organic carbon (DOC) in the aging of biochars. Chromatography analysis indicated that DOC molecules with relatively large molecular weight were preferentially adsorbed on the biochars during the aging processes. DOC sorption led to blockage of the biochar's micropores according to N 2 and CO 2 adsorption analyses. Surface chemistry of the biochars was also substantially modified, with more O-rich functional groups on the aged biochars compared to the original biochars, as evidenced by Near-edge X-ray absorption fine structure (NEXAFS) spectroscopy and X-ray photoelectron spectroscopy (XPS) analyses. The changes in both the physical and chemical surface properties of biochars by DOC led to significant attenuation of the sorption capacity and nonlinearity of the nonionic organic compounds on the aged biochars. Among the tested organic compounds, phenanthrene was the most attenuated in its sorption by the aging treatments, possibly because of its relatively large molecular size and hydrophobicity. The information can help gain a mechanistic understanding of interactions between BCs and organic compounds in soil environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Redox-responsive theranostic nanoplatforms based on inorganic nanomaterials.

Science.gov (United States)

Han, Lu; Zhang, Xiao-Yong; Wang, Yu-Long; Li, Xi; Yang, Xiao-Hong; Huang, Min; Hu, Kun; Li, Lu-Hai; Wei, Yen

2017-08-10

Spurred on by advances in materials chemistry and nanotechnology, scientists have developed many novel nanopreparations for cancer diagnosis and therapy. To treat complex malignant tumors effectively, multifunctional nanomedicines with targeting ability, imaging properties and controlled drug release behavior should be designed and exploited. The therapeutic efficiency of loaded drugs can be dramatically improved using redox-responsive nanoplatforms which can sense the differences in the redox status of tumor tissues and healthy ones. Redox-sensitive nanocarriers can be constructed from both organic and inorganic nanomaterials; however, at present, drug delivery nanovectors progressively lean towards inorganic nanomaterials because of their facile synthesis/modification and their unique physicochemical properties. In this review, we focus specifically on the preparation and application of redox-sensitive nanosystems based on mesoporous silica nanoparticles (MSNs), carbon nanomaterials, magnetic nanoparticles, gold nanomaterials and other inorganic nanomaterials. We discuss relevant examples of redox-sensitive nanosystems in each category. Finally, we discuss current challenges and future strategies from the aspect of material design and practical application. Copyright © 2017 Elsevier B.V. All rights reserved.

Manganese-Loaded Activated Carbon for the Removal of Organosulfur Compounds from High-Sulfur Diesel Fuels

OpenAIRE

Al-Ghouti, M.A.; Al-Degs, Y.S.

2014-01-01

The adsorptive capacity of activated carbon (AC) is significantly enhanced toward weakly interacting organosulfur compounds (OSC) from sulfur-rich diesel fuel. Sulfur compounds are selectively removed from diesel after surface modification by manganese dioxide (MnO2). A selective surface for OSC removal was created by loading MnO2 on the surface; π-complexation between the partially filled d-orbitals of Mn4+ and the S atom is the controlling mechanism for OSC removal. Principal component anal...

Antiradiation compounds XV: condensations of carbon disulfide with amino, chloro, cyanomethyl, and sulfonamido heterocycles

International Nuclear Information System (INIS)

Foye, W.O.; Kauffman, J.M.; Lanzillo, J.J.; LaSala, E.F.

1975-01-01

Condensations of carbon disulfide were carried out with amino, chloro, and diamino heterocycles to give condensed ring thiazoline-2-thiones and imidazoline-2-thiones, with cyanomethyl heterocycles to give dithio acid derivatives, and with heterocyclic sulfonamides to give sulfonyldithiocarbamates. Of several examples tested, pyrido[3,2-d]thiazoline-2-thione, disodium 2-(5-chloro-2-thienyl)-3,3-dimercaptoacrylonitrile, triethylammonium 4-sulfamoylphenyldithiocarbamate, ammonium β-phenethyldithiocarbamate, and methyl N-(thiophene-2-sulfonyl)dithiocarbamate, only the last-named compound showed any radiation protection for mice. Several compounds gave negative tests for antimalarial activity

Functionalization of multilayer fullerenes (carbon nano-onions) using diazonium compounds and "click" chemistry.

Science.gov (United States)

Flavin, Kevin; Chaur, Manuel N; Echegoyen, Luis; Giordani, Silvia

2010-02-19

A novel versatile approach for the functionalization of multilayer fullerenes (carbon nano-onions) has been developed, which involves the facile introduction of a variety of simple functionalities onto their surface by treatment with in situ generated diazonium compounds. This approach is complemented by use of "click" chemistry which was used for the covalent introduction of more complex porphyrin molecules.

[Effects of combined application of biochar and inorganic fertilizers on the available phosphorus content of upland red soil].

Science.gov (United States)

Jing, Yan; Chen, Xiao-min; Liu, Zu-xiang; Huang, Qian-ru; LiI, Qiu-xia; Chen, Chen; Lu, Shao-shan

2013-04-01

Aiming at the low content of available phosphorus in upland red soil of Southern China, this paper studied the effects of combined application of biochar and inorganic fertilizers on the available phosphorus and organic carbon contents and the pH of this soil. With the combined application of biochar and inorganic fertilizers, the soil physical and chemical properties improved to different degrees. As compared with the control, the soil pH and the soil organic carbon and available phosphorus contents at different growth stages of oil rape after the combined application of biochar and inorganic fertilizers all had an improvement, with the increments at bolting stage, flowering stage, and ripening stage being 16%, 24% and 26%, 23%, 34% and 38%, and 100%, 191% and 317% , respectively. The soil pH and the soil organic carbon and available phosphorus contents were increased with the increasing amount of applied biochar. Under-the application of biochar, the soil available phosphorus had a significant correlation with the soil pH and soil organic carbon content. This study could provide scientific basis to improve the phosphorus deficiency and the physical and chemical properties of upland red soil.

Inorganic-organic hybrid polyoxometalate containing supramolecular helical chains: Preparation, characterization and application in chemically bulk-modified electrode

International Nuclear Information System (INIS)

Han Zhangang; Zhao Yulong; Peng Jun; Liu Qun; Wang Enbo

2005-01-01

An inorganic-organic hybrid polyoxometalate (POM) (Hbpy) 4 [SiMo 12 O 40 ] (1) (bpy = 2,4-bipyridine), has been prepared and characterized. X-ray diffraction study reveals that compound 1 contains interesting organic double helical chains. The hybrid nanoparticles was used as a solid bulkmodifier to fabricate a three-dimensional chemically modified carbon paste electrode (1-CPE) by direct mixing. The electrochemical behavior and electrocatalysis of 1-CPE has been studied in detail. The results indicate that 1-CPE has a good electrocatalytic activity toward the reduction of nitrite in 1 M H 2 SO 4 aqueous solution. 1-CPE shows remarkable stability that can be ascribed to the interactions existed between POM anions and organic double helical bpy chains, which are very important for practical applications in electrode modification

Application of response surface methodology to optimise supercritical carbon dioxide extraction of volatile compounds from Crocus sativus.

Science.gov (United States)

Shao, Qingsong; Huang, Yuqiu; Zhou, Aicun; Guo, Haipeng; Zhang, Ailian; Wang, Yong

2014-05-01

Crocus sativus has been used as a traditional Chinese medicine for a long time. The volatile compounds of C. sativus appear biologically active and may act as antioxidants as well as anticonvulsants, antidepressants and antitumour agents. In order to obtain the highest possible yield of essential oils from C. sativus, response surface methodology was employed to optimise the conditions of supercritical fluid carbon dioxide extraction of the volatile compounds from C. sativus. Four factorswere investigated: temperature, pressure, extraction time and carbon dioxide flow rate. Furthermore, the chemical compositions of the volatile compounds extracted by supercritical fluid extraction were compared with those obtained by hydro-distillation and Soxhlet extraction. The optimum extraction conditions were found to be: optimised temperature 44.9°C, pressure 34.9 MPa, extraction time 150.2 min and CO₂ flow rate 10.1 L h⁻¹. Under these conditions, the mean extraction yield was 10.94 g kg⁻¹. The volatile compounds extracted by supercritical fluid extraction and Soxhlet extraction contained a large amount of unsaturated fatty acids. Response surface methodology was successfully applied for supercritical fluid CO₂ extraction optimisation of the volatile compounds from C. sativus. The study showed that pressure and CO₂ flow rate had significant effect on volatile compounds yield produced by supercritical fluid extraction. This study is beneficial for the further research operating on a large scale. © 2013 Society of Chemical Industry.

Inorganic Polymer Matrix Composite Strength Related to Interface Condition

Directory of Open Access Journals (Sweden)

John Bridge

2009-12-01

Full Text Available Resin transfer molding of an inorganic polymer binder was successfully demonstrated in the preparation of ceramic fiber reinforced engine exhaust valves. Unfortunately, in the preliminary processing trials, the resulting composite valves were too brittle for in-engine evaluation. To address this limited toughness, the effectiveness of a modified fiber-matrix interface is investigated through the use of carbon as a model material fiber coating. After sequential heat treatments composites molded from uncoated and carbon coated fibers are compared using room temperature 3-point bend testing. Carbon coated Nextel fiber reinforced geopolymer composites demonstrated a 50% improvement in strength, versus that of the uncoated fiber reinforced composites, after the 250 °C postcure.

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

International Nuclear Information System (INIS)

Fonyuy, Ernest W.; Atekwana, Eliot A.

2008-01-01

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 (δ 13 C DIC ) in receiving streams. We examined spatial and seasonal variations in physical and chemical parameters, DIC, and δ 13 C DIC 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 Fe 2+ , alkalinity, and DIC, and variable increase in δ 13 C DIC . We attribute the decrease in alkalinity, DIC loss, and enrichment of 13 C of DIC in stream water to protons produced from oxidation of Fe 2+ followed by Fe 3+ hydrolysis and precipitation of Fe(OH) 3(s) . The extent of DIC decrease and 13 C enrichment of DIC was related to the amount of HCO 3 - dehydrated by protons. The laboratory experiment showed that lower 13 C enrichment occurred in unmixed AMD (2.7 per mille ) when the amount of protons produced was in excess of HCO 3 - or in tap water (3.2 per mille ) where no protons were produced from Fe 3+ hydrolysis for HCO 3 - dehydration. The 13 C enrichment increased and was highest for AMD-tap water mixture (8.0 per mille ) where Fe 2+ was proportional to HCO 3 - concentration. Thus, the variable downstream and seasonal 13 C enrichment in stream water was due in part to: (1) variations in the volume of stream water initially mixed with AMD and (2) to HCO 3 - 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

Mechanisms of inorganic-carbon acquisition in marine phytoplankton and their implications for the use of other resources

International Nuclear Information System (INIS)

Raven, J.A.; Johnston, A.M.

1991-01-01

Most of the marine phytoplankton species for which data are available are rate saturated for photosynthesis and probably for growth with inorganic C at normal seawater concentrations; 2 of the 17 species are not saturated. Photosynthesis in these two species can probably be explained by the 17 species not saturated. Photosynthesis in these two species can probably be explained by assuming that CO 2 reaches the site of its reaction with RUBISCO (ribulose bisphosphate carboxylase-oxygenase) by passive diffusion. The kinetics of CO 2 fixation by intact cells are explicable by RUBISCO kinetics typical of algae, and a CO 2 -saturated in vivo RUBISCO activity not more than twice the in vivo light- and inorganic-C-saturated rate of photosynthesis. For the other species, the high affinity in vivo for inorganic C could be other species, the high affinity in vivo for inorganic C could be explained by postulating active influx of inorganic C yielding a higher concentration of CO 2 available to RUBISCO during steady state photosynthesis than in the medium. Although such a higher concentration of internal CO 2 in cells with high affinity for inorganic C is found at low levels of external inorganic C, the situation is more equivocal at normal seawater concentrations. In theory, the occurrence of a CO 2 -concentrating mechanism rather than passive CO 2 entry could reduce the photon, N, Fe, Mn, and Mo costs of growth, but increase the Zn and Se costs. Thus far, data on costs are available only for photons and N; these data generally agree with the predicted lower costs for cells with high affinity for inorganic C

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.

Ionising radiation effect on the luminescence emission of inorganic and biogenic calcium carbonates

Science.gov (United States)

Boronat, C.; Correcher, V.; Virgos, M. D.; Garcia-Guinea, J.

2017-06-01

As known, the luminescence emission of mineral phases could be potentially employed for dosimetric purposes in the case of radiological terrorism or radiation accident where conventional monitoring is not available. In this sense, this paper reports on the thermo- (TL) and cathodoluminescence (CL) emission of both biogenic (common periwinkle - littorina littorera - shell made of calcite 90% and aragonite 10%) and inorganic (aragonite 100%) Ca-rich carbonates previously characterized by X-ray diffraction and Raman spectroscopy. Whereas the aragonite sample displays the main CL waveband peaked in the red region (linked to point defects), the more intense emission obtained from the common periwinkle shell appears at higher energies (mainly associated with structural defects). The UV-blue TL emission of the samples, regardless of the origin, displays (i) an acceptable ionizing radiation sensitivity, (ii) linear dose response in the range of interest (up to 8 Gy), (iii) reasonable stability of the TL signal after 700 h of storage with an initial decay of ca. 88% for the mineral sample and 60% for the biogenic sample and maintaining the stability from 150 h onwards. (iv) The tests of thermal stability of the TL emission performed in the range of 180-320 °C confirm a continuum in the trap system.

Identification of inorganic anions by gas chromatography/mass spectrometry.

Science.gov (United States)

Sakayanagi, Masataka; Yamada, Yaeko; Sakabe, Chikako; Watanabe, Kunio; Harigaya, Yoshihiro

2006-03-10

Inorganic anions were identified by using gas chromatography/mass spectrometry (GC/MS). Derivatization of the anions was achieved with pentafluorobenzyl p-toluenesulphonate (PFB-Tos) as the reaction reagent and a crown ether as a phase transfer catalyst. When PFB-Br was used as the reaction reagent, the retention time of it was close to those of the derivatized inorganic anions and interfered with the analysis. In contrast, the retention time of PFB-Tos differed greatly from the PFB derivatives of the inorganic anions and the compounds of interest could be detected without interference. Although the PFB derivatives of SO4, S2O3, CO3, ClO4, and ClO3 could not be detected, the derivatives of F, Cl, Br, I, CN, OCN, SCN, N3, NO3, and NO2 were detected using PFB-Tos as the derivatizing reagent. The inorganic anions were detectable within 30 ng approximately, which is of sufficient sensitivity for use in forensic chemistry. Accurate mass number was measured for each PFB derivative by high-resolution mass spectrometry (HRMS) within a measurement error of 2 millimass units (mmu), which allowed determination of the compositional formula from the mass number. In addition, actual analysis was performed successively by our method using trial samples of matrix.

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: DPApH (pHactivated carbon 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. Copyright © 2015 Elsevier B.V. All rights reserved.

Organic and inorganic composition and microbiology of produced waters from Pennsylvania shale gas wells

Science.gov (United States)

Akob, Denise M.; Cozzarelli, Isabelle M.; Dunlap, Darren S.; Rowan, Elisabeth L.; Lorah, Michelle M.

2015-01-01

Hydraulically fractured shales are becoming an increasingly important source of natural gas production in the United States. This process has been known to create up to 420 gallons of produced water (PW) per day, but the volume varies depending on the formation, and the characteristics of individual hydraulic fracture. PW from hydraulic fracturing of shales are comprised of injected fracturing fluids and natural formation waters in proportions that change over time. Across the state of Pennsylvania, shale gas production is booming; therefore, it is important to assess the variability in PW chemistry and microbiology across this geographical span. We quantified the inorganic and organic chemical composition and microbial communities in PW samples from 13 shale gas wells in north central Pennsylvania. Microbial abundance was generally low (66–9400 cells/mL). Non-volatile dissolved organic carbon (NVDOC) was high (7–31 mg/L) relative to typical shallow groundwater, and the presence of organic acid anions (e.g., acetate, formate, and pyruvate) indicated microbial activity. Volatile organic compounds (VOCs) were detected in four samples (∼1 to 11.7 μg/L): benzene and toluene in the Burket sample, toluene in two Marcellus samples, and tetrachloroethylene (PCE) in one Marcellus sample. VOCs can be either naturally occurring or from industrial activity, making the source of VOCs unclear. Despite the addition of biocides during hydraulic fracturing, H2S-producing, fermenting, and methanogenic bacteria were cultured from PW samples. The presence of culturable bacteria was not associated with salinity or location; although organic compound concentrations and time in production were correlated with microbial activity. Interestingly, we found that unlike the inorganic chemistry, PW organic chemistry and microbial viability were highly variable across the 13 wells sampled, which can have important implications for the reuse and handling of these fluids

Effect of salt stress on growth and contents of organic and inorganic ...

African Journals Online (AJOL)

Effect of salt stress on growth and contents of organic and inorganic compounds in noni ( Morinda citrifolia L.) ... seedlings at 1, 10, 20, 30 and 40 days of salt stress in a 5 x 2 completely randomized experimental design. ... from 32 Countries:.

Radwaste issues belong in the inorganic classroom

International Nuclear Information System (INIS)

Williams, D.H.

1991-01-01

The safe isolation of high level radioactive wastes is a matter of significant importance. This material is derived primarily from spent nuclear fuel and defense weapon production. Every element on the periodic chart is represented. The majority are metallic elements. Over the thousands of years that they are to be isolated the primary chemistry will be oxidation. The mobility and fate of particular inner and outer transition element ions become very important. For that, one must understand their hydrolytic nature, their complexing tendencies and the solubilities of various compounds. This topic could easily serve as a centerpiece for an inorganic chemistry course. At the very least, it demands the attention of every teacher of inorganic chemistry and consideration by those whose research is directed to tangible problems. The discussion includes notes on the abundance and lifetimes of particular radioisotopes. The positive student responses to this approach are also shared

Investigations of inorganic and hybrid inorganic-organic nanostructures

Science.gov (United States)

Kam, Kinson Chihang

This thesis focuses on the exploratory synthesis and characterization of inorganic and hybrid inorganic-organic nanomaterials. In particular, nanostructures of semiconducting nitrides and oxides, and hybrid systems of nanowire-polymer composites and framework materials, are investigated. These materials are characterized by a variety of techniques for structure, composition, morphology, surface area, optical properties, and electrical properties. In the study of inorganic nanomaterials, gallium nitride (GaN), indium oxide (In2O3), and vanadium dioxide (VO2) nanostructures were synthesized using different strategies and their physical properties were examined. GaN nanostructures were obtained from various synthetic routes. Solid-state ammonolysis of metastable gamma-Ga2O 3 nanoparticles was found to be particularly successful; they achieved high surface areas and photoluminescent study showed a blue shift in emission as a result of surface and size defects. Similarly, In2O3 nanostructures were obtained by carbon-assisted solid-state syntheses. The sub-oxidic species, which are generated via a self-catalyzed vapor-liquid-solid mechanism, resulted in 1D nanostructures including nanowires, nanotrees, and nanobouquets upon oxidation. On the other hand, hydrothermal methods were used to obtain VO2 nanorods. After post-thermal treatment, infrared spectroscopy demonstrated that these nanorods exhibit a thermochromic transition with temperature that is higher by ˜10°C compared to the parent material. The thermochromic behavior indicated a semiconductor-to-metal transition associated with a structural transformation from monoclinic to rutile. The hybrid systems, on the other hand, enabled their properties to be tunable. In nanowire-polymer composites, zinc oxide (ZnO) and silver (Ag) nanowires were synthesized and incorporated into polyaniline (PANI) and polypyrrole (PPy) via in-situ and ex-situ polymerization method. The electrical properties of these composites are

Synthesis, structural characterization, thermal analysis, and DFT calculation of a novel zinc (II)-trifluoro-β-diketonate 3D supramolecular nano organic-inorganic compound with 1,3,5-triazine derivative

Energy Technology Data Exchange (ETDEWEB)

Mirtamizdoust, Babak, E-mail: babakm.tamizdoust@gmail.com [Department of Chemistry, Yasouj University, Yasouj, 75918-74831 (Iran, Islamic Republic of); Department of Chemistry, Faculty of Science, University of Qom, PO Box 37185-359, Qom, Islamic Republic of Iran (Iran, Islamic Republic of); Ghaedi, Mehrorang [Department of Chemistry, Yasouj University, Yasouj, 75918-74831 (Iran, Islamic Republic of); Hanifehpour, Younes, E-mail: y_hanifehpour@yu.ac.kr [School of Mechanical Engineering, WCU Nano Research Center, Yeungnam University, Gyongsan, 712-749 (Korea, Republic of); Mague, Joel T. [Department of Chemistry, Tulane University, New Orleans (United States); Joo, Sang Woo, E-mail: swjoo1@gmail.com [School of Mechanical Engineering, WCU Nano Research Center, Yeungnam University, Gyongsan, 712-749 (Korea, Republic of)

2016-10-01

A sonochemical method was used to synthesize a novel nano-structure of a zinc(II) organic-inorganic compound [Zn(dapt){sub 2}(ttfa){sub 2}] (1) [dapt = 2,4-diamino-6-phenyl-1,3,5-triazine and ttfa = 2-thenoyltrifluoroacetonate]. The new nanostructure was characterized by scanning electron microscopy, X-ray powder diffraction, elemental analysis, and thermal analysis. The single-crystal X-ray structure shows that 1 is a discrete coordination compound. Strong intra- and intermolecular hydrogen bonds are observed in the structure with the latter forming chains of molecules running parallel to (110). The chains are further extended into a three-dimensional supramolecular structure by intermolecular C−F⋯π interactions between trifluoromethyl and triazine moieties. The coordination number of the zinc(II) ion is six (ZnN{sub 2}O{sub 4}), and the coordination sphere is tetragonally elongated octahedral. The structure of the title complex was optimized by DFT calculations. - Highlights: • A new zinc(II) 3D coordination supramolecular compound was synthesized. • Ultrasound synthesis of nano coordination compound have been reported. • The X-ray crystal structure of the compound is reported.

A lake classification concept for a more accurate global estimate of the dissolved inorganic carbon export from terrestrial ecosystems to inland waters

Science.gov (United States)

Engel, Fabian; Farrell, Kaitlin J.; McCullough, Ian M.; Scordo, Facundo; Denfeld, Blaize A.; Dugan, Hilary A.; de Eyto, Elvira; Hanson, Paul C.; McClure, Ryan P.; Nõges, Peeter; Nõges, Tiina; Ryder, Elizabeth; Weathers, Kathleen C.; Weyhenmeyer, Gesa A.

2018-04-01

The magnitude of lateral dissolved inorganic carbon (DIC) export from terrestrial ecosystems to inland waters strongly influences the estimate of the global terrestrial carbon dioxide (CO2) sink. At present, no reliable number of this export is available, and the few studies estimating the lateral DIC export assume that all lakes on Earth function similarly. However, lakes can function along a continuum from passive carbon transporters (passive open channels) to highly active carbon transformers with efficient in-lake CO2 production and loss. We developed and applied a conceptual model to demonstrate how the assumed function of lakes in carbon cycling can affect calculations of the global lateral DIC export from terrestrial ecosystems to inland waters. Using global data on in-lake CO2 production by mineralization as well as CO2 loss by emission, primary production, and carbonate precipitation in lakes, we estimated that the global lateral DIC export can lie within the range of {0.70}_{-0.31}^{+0.27} to {1.52}_{-0.90}^{+1.09} Pg C yr-1 depending on the assumed function of lakes. Thus, the considered lake function has a large effect on the calculated lateral DIC export from terrestrial ecosystems to inland waters. We conclude that more robust estimates of CO2 sinks and sources will require the classification of lakes into their predominant function. This functional lake classification concept becomes particularly important for the estimation of future CO2 sinks and sources, since in-lake carbon transformation is predicted to be altered with climate change.

Influence of surface chemistry of carbon materials on their interactions with inorganic nitrogen contaminants in soil and water.

Science.gov (United States)

Sumaraj; Padhye, Lokesh P

2017-10-01

Inorganic nitrogen contaminants (INC) (NH 4 + , NO 3 - , NO 2 - , NH 3 , NO, NO 2 , and N 2 O) pose a growing risk to the environment, and their remediation methods are highly sought after. Application of carbon materials (CM), such as biochar and activated carbon, to remediate INC from agricultural fields and wastewater treatment plants has gained a significant interest since past few years. Understanding the role of surface chemistry of CM in adsorption of various INC is highly critical to increase adsorption efficiency as well as to assess the long term impact of using these highly recalcitrant CM for remediation of INC. Critical reviews of adsorption studies related to INC have revealed that carbon surface chemistry (surface functional groups, pH, Eh, elemental composition, and mineral content) has significant influence on adsorption of INC. Compared to basic functional groups, oxygen containing surface functional groups have been found to be more influential for adsorption of INC. However, basic sites on carbon materials still play an important role in chemisorption of anionic INC. Apart from surface functional groups, pH, Eh and pH zpc of CM and elemental and mineral composition of its surface are important properties capable of altering INC interactions with CM. This review summarizes our current understanding of INC interactions with CM's surface through the known chemisorption mechanisms: electrostatic interaction, hydrogen bonding, electron donor-acceptor mechanism, hydrophobic and hydrophilic interaction, chemisorption aided by minerals, and interactions influenced by pH and elemental composition. Change in surface chemistry of CM in soil during aging is also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mechanism study on inorganic oxidants induced inhibition of Ru(bpy)₃²+ electrochemiluminescence and its application for sensitive determination of some inorganic oxidants.

Science.gov (United States)

Qiu, Bin; Xue, Lingling; Wu, Yanping; Lin, Zhenyu; Guo, Longhua; Chen, Guonan

2011-07-15

Inhibited Ru(bpy)(3)(2+) electrochemiluminescence by inorganic oxidants is investigated. Results showed that a number of inorganic oxidants can quench the ECL of Ru(bpy)(3)(2+)/tri-n-propylamine (TPrA) system, and the logarithm of the decrease in ECL intensity (ΔI) was proportional to the logarithm of analyte concentrations. Based on which, a sensitive approach for detection of these inorganic oxidants was established, e.g. the log-log plots of ΔI versus the concentration of MnO(4)(-), Cr(2)O(7)(2-) and Fe(CN)(6)(3-) are linear in the range of 1×10(-7) to 3×10(-4)M for MnO(4)(-) and Cr(2)O(7)(2-), and 1×10(-7) to 1×10(-4)M for Fe(CN)(6)(3-), with the limit of detection (LOD) of 8.0×10(-8)M, 2×10(-8)M, and 1×10(-8)M, respectively. A series of experiments such as a comparison of the inhibitory effect of different compounds on Ru(bpy)(3)(2+)/TPrA ECL, ECL emission spectra, UV-Vis absorption spectra etc. were investigated in order to discover how these inorganic analytes quench the ECL of Ru(bpy)(3)(2+)/TPrA system. A mechanism based on consumption of TPrA intermediate (TPrA(·)) by inorganic oxidants was proposed. Copyright © 2011 Elsevier B.V. All rights reserved.

Applications of compound-specific carbon isotope ratios in organic contaminant studies

International Nuclear Information System (INIS)

Aravena, R.; Hunkeler, D.; Bloom, Y.; Frape, S.K.; Butler, B.; Edwards, E.; Cox, E.

1999-01-01

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 δ 13 C 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 δ 13 C of each dechlorination product was always more negative than the δ 13 C of the corresponding precursor. In addition, the δ 13 C 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)

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)

Brandenburg, N.P.

1978-01-01

The first part of this thesis is concerned with parameter methods for estimating the standard enthalpy of formation, ΔH 0 sub(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-UO 2 SO 4 , UO 2 SeO 3 , and α-UO 2 SeO 4 . Thermochemical measurements have been restricted to the determination of ΔH 0 sub(f)(UO 2 SO 3 ) and ΔH 0 sub(f)(UO 2 TeO 3 ) by means of isoperibol solution calorimetry. (Auth.)

One-carbon (bio ?) Geochemistry in Subsurface Waters of the Serpentinizing Coast Range Ophiolite

Science.gov (United States)

Hoehler, Tori M.; Mccollom, Tom; Schrenk, Matt; Cardace, Dawn

2011-01-01

Serpentinization - the aqueous alteration of ultramafic rocks - typically imparts a highly reducing and alkaline character to the reacting fluids. In turn, these can influence the speciation and potential for metabolism of one-carbon compounds in the system. We examined the aqueous geochemistry and assessed the biological potential of one-carbon compounds in the subsurface of the McLaughlin Natural Reserve (Coast Range Ophiolite, California, USA). Fluids from wells sunk at depths of 25-90 meters have pH values ranging from 9.7 to 11.5 and dissolved inorganic carbon (DIC concentrations) generally below 60 micromolar. Methane is present at concentrations up to 1.3 millimolar (approximately one-atmosphere saturation), and hydrogen concentrations are below 15 nanomolar, suggesting active consumption of H2 and production of CH4. However, methane production from CO2 is thermodynamically unfavorable under these conditions. Additionally, the speciation of DIC predominantly into carbonate at these high pH values creates a problem of carbon availability for any organisms that require CO2 (or bicarbonate) for catabolism or anabolism. A potential alternative is carbon monoxide, which is present in these waters at concentrations 2000-fold higher than equilibrium with atmospheric CO. CO is utilized in a variety of metabolisms, including methanogenesis, and bioavailability is not adversely affected by pH-dependent speciation (as for DIC). Methanogenesis from CO under in situ conditions is thermodynamically favorable and would satisfy biological energy requirements with respect to both Gibbs Energy yield and power.

Voltammetric methods for determination and speciation of inorganic arsenic in the environment-A review

Energy Technology Data Exchange (ETDEWEB)

Mays, Douglas E. [Centre for Clean Water and Sustainable Technologies, Department of Chemistry and Biochemistry, George Mason University, Fairfax, VA 20120 (United States); Hussam, Abul, E-mail: ahussam@gmu.edu [Centre for Clean Water and Sustainable Technologies, Department of Chemistry and Biochemistry, George Mason University, Fairfax, VA 20120 (United States)

2009-07-30

The measurement of inorganic arsenic in the environment has received considerable attention over the past 40+ years due to its toxicity and prevalence in drinking water. This paper provides an overview of voltammetric techniques used since 2001. More than fifty papers from refereed analytical chemistry journals on the speciation and measurement of inorganic arsenic (As(III) and As(V)) in practical and environmental samples are included. The present review shows that stripping voltammetry is a sensitive and inexpensive technique. The new approaches include development of novel measurement protocols through media variation, development and use of new boron doped diamond electrodes modified with metals, nano Au-modified electrodes on carbon or carbon nano-tubes, novel rotating disc and vibrating electrodes to enhance mass transfer, and modified Hg(l) and thin film Bi on carbon for cathodic stripping voltammetry are discussed. Although, majority of the papers were of exploratory in nature, the trend towards developing a commercial standalone instrument for field use is still in progress.

Combustion synthesis of inorganic materials; Muki zairyo no nensho gose

Energy Technology Data Exchange (ETDEWEB)

Oyanagi, M. [Ryukoku University, Kyoto (Japan)

1999-11-01

Combustion synthesis of porous titan carbide is outlined. In combustion synthesis, exothermic chain reaction, which is induced by igniting at one point of the simple substance mixture, propagates the combustion wave, and the compound is synthesized, which can be sintered by it. By this method, to this day intermetallic compounds, ceramics and high melting point composite materials have been synthesized, and synthetics can be made compact by adding pressure during or just after the reaction. Recently, applying the induction heating jointly, preheating before the reaction and heat treatment after the reaction can be controlled, accordingly, many high melting point inorganic compounds and composite materials can be made by combustion synthesis under pressure. (NEDO)

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

Science.gov (United States)

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

2012-01-01

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

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

Institute of Scientific and Technical Information of China (English)

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

2012-01-01

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

Composition of atmospheric precipitation. I. Nitrogen compounds

Energy Technology Data Exchange (ETDEWEB)

Eriksson, E

1952-01-01

The purpose of this paper is to present a survey of published data on chemical analysis of atmospheric precipitation to discuss different cycles proposed for inorganic compounds in atmospheric precipitation and, finally, to assess the importance of these compounds from different points of view. Investigations of rainwater with a view to determine atmospheric pollution in industrial areas are mentioned incidentally but no results are detailed.

Data on changes in red wine phenolic compounds, headspace aroma compounds and sensory profile after treatment of red wines with activated carbons with different physicochemical characteristics

OpenAIRE

Filipe-Ribeiro, Lu?s; Milheiro, Juliana; Matos, Carlos C.; Cosme, Fernanda; Nunes, Fernando M.

2017-01-01

Data in this article presents the changes on phenolic compounds, headspace aroma composition and sensory profile of a red wine spiked with 4-ethylphenol and 4-ethylguaiacol and treated with seven activated carbons with different physicochemical characteristics, namely surface area, micropore volume and mesopore volume (“Reduction of 4-ethylphenol and 4-ethylguaiacol in red wine by activated carbons with different physicochemical characteristics: impact on wine quality” Filipe-Ribeiro et al. (...

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)

Ferreira, Manuel Octavio M.; Sato, Ivone Mulako; Salvador, Vera Lucia R.

2005-01-01

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 N 2 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)

Enhanced energy density of carbon-based supercapacitors using Cerium (III) sulphate as inorganic redox electrolyte

International Nuclear Information System (INIS)

Díaz, Patricia; González, Zoraida; Santamaría, Ricardo; Granda, Marcos; Menéndez, Rosa; Blanco, Clara

2015-01-01

Highlights: •Ce 2 (SO 4 ) 3 /H 2 SO 4 redox electrolyte as a new route to increase the energy density of SCs. •Increased operating cell voltage with no electrolyte decomposition. •Redox reactions on the battery-type electrode. •The negative electrode retains its capacitor behaviour. •Outstanding energy density values compared to those measured in H 2 SO 4 . -- ABSTRACT: The energy density of carbon based supercapacitors (CBSCs) was significantly increased by the addition of an inorganic redox species [Ce 2 (SO 4 ) 3 ] to an aqueous electrolyte (H 2 SO 4 ). The development of the faradaic processes on the positive electrode not only significantly increased the capacitance but also the operational cell voltage of these devices (up to 1.5 V) due to the high redox potentials at which the Ce 3+ /Ce 4+ reactions occur. Therefore, in asymmetric CBSCs assembled using an activated carbon as negative electrode and MWCNTs as the positive one, the addition of Ce 2 (SO 4 ) 3 moderately increases the energy density of the device (from 1.24 W h kg −1 to 5.08 W h kg −1 ). When a modified graphite felt is used as positive electrode the energy density of the cell reaches values as high as 13.84 W h kg −1 . The resultant systems become asymmetric hybrid devices where energy is stored due to the electrical double layer formation in the negative electrode and the development of the faradaic process in the positive electrode, which acts as a battery-type electrode

Total and inorganic arsenic in fish, seafood and seaweeds--exposure assessment.

Science.gov (United States)

Mania, Monika; Rebeniak, Małgorzata; Szynal, Tomasz; Wojciechowska-Mazurek, Maria; Starska, Krystyna; Ledzion, Ewa; Postupolski, Jacek

2015-01-01

According to the European Food Safety Authority (EFSA), fish, seafood and seaweeds are foodstuffs that significantly contribute to dietary arsenic intake. With the exception of some algal species, the dominant compounds of arsenic in such food products are the less toxic organic forms. Both the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and EFSA recommend that speciation studies be performed to determine the different chemical forms in which arsenic is present in food due to the differences in their toxicity. Knowing such compositions can thus enable a complete exposure assessment to be made. Determination of total and inorganic arsenic contents in fish, their products, seafood and seaweeds present on the Polish market. This was then followed by an exposure assessment of consumers to inorganic arsenic in these foodstuffs. Total and inorganic arsenic was determined in 55 samples of fish, their products, seafood as well as seaweeds available on the market. The analytical method was hydride generation atomic absorption spectrometry (HGAAS), after dry ashing of samples and reduction of arsenic to arsenic hydride using sodium borohydride. In order to isolate only the inorganic forms of arsenic prior to mineralisation, samples were subjected to concentrated HCl hydrolysis, followed by reduction with hydrobromic acid and hydrazine sulphate after which triple chloroform extractions and triple 1M HCl re-extractions were performed. Exposure of adults was estimated in relation to the Benchmark Dose Lower Confidence Limit (BMDL0.5) as set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) that resulted in a 0.5% increase in lung cancer (3.0 μg/kg body weight (b.w.) per day). Mean total arsenic content from all investigated fish samples was 0.46 mg/kg (90th percentile 0.94 mg/kg), whilst the inorganic arsenic content never exceeded the detection limit of the analytical method used (0.025 mg/kg). In fish products, mean total arsenic concentration was

Constraining wintertime sources of inorganic chlorine over the northeast United States

Science.gov (United States)

Haskins, J.; Jaegle, L.; Shah, V.; Lopez-Hilfiker, F.; Lee, B. H.; Campuzano Jost, P.; Schroder, J. C.; Day, D. A.; Fiddler, M. N.; Holloway, J. S.; Sullivan, A.; Veres, P. R.; Weber, R. J.; Dibb, J. E.; Brown, S. S.; Jimenez, J. L.; Thornton, J. A.

2017-12-01

Wintertime multiphase chlorine chemistry is thought to play a significant role in the regional distribution of oxidants, the lifetime of VOCs, and the transport of NOx downwind of urban sources. However, the sources and chemistry of reactive chlorine remain highly uncertain. During the WINTER 2015 aircraft campaign, the inorganic chlorine budget was dominated by HCl (g) and total particulate chloride, accounting for greater than 85% of the total chlorine budget within the boundary layer. The total concentration of inorganic chlorine compounds found over marine regions was 1014 pptv and 609 pptv over continental regions with variability found to be driven by changes in meteorological conditions, particle liquid water content, particle pH, and proximity to large anthropogenic sources. However, displacement of particle chloride was often not a large enough source to fully explain the concentrations of gas phase Cly compounds. We use the GEOS-Chem global chemical transport model to simulate the emissions, gas-particle partitioning, and downwind transport and deposition of Cly during winter. Simulated concentrations of HCl, particle chloride, and other dominant Cly compounds are compared to measurements made during the WINTER aircraft campaign. The relative roles of Cly sources from sea-salt aerosol and anthropogenic sources such as power plants, biomass burning and road salt are explored.

Predicting Organic Cation Sorption Coefficients: Accounting for Competition from Sorbed Inorganic Cations Using a Simple Probe Molecule.

Science.gov (United States)

Jolin, William C; Goyetche, Reaha; Carter, Katherine; Medina, John; Vasudevan, Dharni; MacKay, Allison A

2017-06-06

With the increasing number of emerging contaminants that are cationic at environmentally relevant pH values, there is a need for robust predictive models of organic cation sorption coefficients (K d ). Current predictive models fail to account for the differences in the identity, abundance, and affinity of surface-associated inorganic exchange ions naturally present at negatively charged receptor sites on environmental solids. To better understand how organic cation sorption is influenced by surface-associated inorganic exchange ions, sorption coefficients of 10 organic cations (including eight pharmaceuticals and two simple probe organic amines) were determined for six homoionic forms of the aluminosilicate mineral, montmorillonite. Organic cation sorption coefficients exhibited consistent trends for all compounds across the various homoionic clays with sorption coefficients (K d ) decreasing as follows: K d Na + > K d NH 4 + ≥ K d K + > K d Ca 2+ ≥ K d Mg 2+ > K d Al 3+ . This trend for competition between organic cations and exchangeable inorganic cations is consistent with the inorganic cation selectivity sequence, determined for exchange between inorganic ions. Such consistent trends in competition between organic and inorganic cations suggested that a simple probe cation, such as phenyltrimethylammonium or benzylamine, could capture soil-to-soil variations in native inorganic cation identity and abundance for the prediction of organic cation sorption to soils and soil minerals. Indeed, sorption of two pharmaceutical compounds to 30 soils was better described by phenyltrimethylammonium sorption than by measures of benzylamine sorption, effective cation exchange capacity alone, or a model from the literature (Droge, S., and Goss, K. Environ. Sci. Technol. 2013, 47, 14224). A hybrid approach integrating structural scaling factors derived from this literature model of organic cation sorption, along with phenyltrimethylammonium K d values, allowed for

Determination of inorganic beryllium species in the particulate matter of emissions and working areas

Energy Technology Data Exchange (ETDEWEB)

Profumo, A.; Spini, G.; Cucca, L.; Pesavento, M. [Dipartimento di Chimica Gen., Pavia (Italy)

2002-07-01

A sequential extraction procedure for separating and determining Be(0), soluble Be(II) inorganic compounds, BeO and beryllium silicates in samples, such as particulate matter of emissions and working areas, has been developed. The proposed procedure has been tested on synthetic samples prepared with the inorganic beryllium compounds, in the presence of atmospherical particulate matter sampled in a laboratory, previously checked for the absence of beryllium. The speciation was then repeated on a sample of fly ash deriving from a solid waste incinerator and on a reference material (Coal Fly ash SRM 1633a, by NIST), followed by an evaluation of matrix spiking and recovery analyses. Performing multiple analyses of the spiked samples assessed the repeatability of the procedure. Quantitative determinations have been made by inductively coupled plasma optical emission spectrometry (ICP-OES) and electrothermal atomic absorption spectrometry (ETAAS). The possible interferences of the most common ions have been investigated. The selective sequential extractions allow one to separate and to determine different inorganic beryllium species, to which a different toxicity and therefore, a different risk are related: it is the case for example of metallic beryllium and beryllium oxide.

Behaviour of mercury compounds in soil

Energy Technology Data Exchange (ETDEWEB)

Booer, J R

1944-01-01

The uses of inorganic compounds of mercury for the control of plant pests is reviewed, and a summary of the relevant chemical and physical properties of the compounds concerned is given. On chemical evidence a working hypothesis is propounded showing that all compounds may be expected to decompose into metallic mercury. A pot technique is described by means of which a correlation can be obtained between the effective mercury content of a given soil sample and the rate of growth of wheat seedlings. The mathematical treatment of the results is described, and the validity of the pot technique is verified by statistical analysis of results. Using the pot technqiue it is shown that volatilization losses are insignificant but that mercury is slowly rendered ineffective by the formation of mercuric sulphide. The effect of sulphur-reducing bacteria is considered and the influence of Vibrio desulphuricans on mercury is studied in detail. Experimental evidence obtained by the pot technique is produced to show that mercurous chloride slowly decomposes in the soil giving mercury and mercuric chloride, mercuric chloride rapidly decomposes into mercury and mercurous chloride, and other inorganic compounds decompose directly into mercury. The working hypothesis is substantiated in all major aspects. The uses and properties of the organo-mercury compounds are then discussed. Type compounds selected are ethyl mercury phosphate, phenyl mercury acetate and methoxyethyl mercury acetate. Using the pot technique it is shown that the formation of organo-mercury clays takes place and that these clays decompose giving metallic mercury. A mechanism is suggested.

Molecular Characterization of a Dual Domain Carbonic Anhydrase From the Ctenidium of the Giant Clam, Tridacna squamosa, and Its Expression Levels After Light Exposure, Cellular Localization, and Possible Role in the Uptake of Exogenous Inorganic Carbon

Directory of Open Access Journals (Sweden)

Clarissa Z. Y. Koh

2018-03-01

Full Text Available A Dual-Domain Carbonic Anhydrase (DDCA had been sequenced and characterized from the ctenidia (gills of the giant clam, Tridacna squamosa, which lives in symbiosis with zooxanthellae. DDCA was expressed predominantly in the ctenidium. The complete cDNA coding sequence of DDCA from T. squamosa comprised 1,803 bp, encoding a protein of 601 amino acids and 66.7 kDa. The deduced DDCA sequence contained two distinct α-CA domains, each with a specific catalytic site. It had a high sequence similarity with tgCA from Tridacna gigas. In T. squamosa, the DDCA was localized apically in certain epithelial cells near the base of the ctenidial filament and the epithelial cells surrounding the tertiary water channels. Due to the presence of two transmembrane regions in the DDCA, one of the Zn2+-containing active sites could be located externally and the other one inside the cell. These results denote that the ctenidial DDCA was positioned to dehydrate HCO3- to CO2 in seawater, and to hydrate the CO2 that had permeated the apical membrane back to HCO3- in the cytoplasm. During insolation, the host clam needs to increase the uptake of inorganic carbon from the ambient seawater to benefit the symbiotic zooxanthellae; only then, can the symbionts conduct photosynthesis and share the photosynthates with the host. Indeed, the transcript and protein levels of DDCA/DDCA in the ctenidium of T. squamosa increased significantly after 6 and 12 h of exposure to light, respectively, denoting that DDCA could participate in the light-enhanced uptake and assimilation of exogenous inorganic carbon.

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

International Nuclear Information System (INIS)

Shikata, Eiji

1981-12-01

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 35 Cl(n,p) 35 S and 35 Cl(n,α) 32 P 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[ 35 S] was reduced with tin(II)-phosphoric acid to hydrogen sulfide[ 35 S], which was oxidized to elementary sulfur[ 35 S]. Sulfate[ 35 S] of sodium or copper(II) was precipitated from an aqueous solution of sodium or copper(II) chloride containing carrier-free sulfate [ 35 S] by adding carrier of either one of the sulfates and ethanol. Copper(II) sulfate[ 35 S] was pyrolyzed to evolve sulfur[ 35 S] dioxide, which was fixed in a sodium hydroxide solution as sodium sulfite[ 35 S]. This was allowed to react with colloidal sulfur in a boiling solution in the presence of 2-octanol to form thiosulfate[ 35 S] 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 [ 35 S]. (author)

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

International Nuclear Information System (INIS)

Nardi, Daniela T.; Saiki, Mitiko; Vasconcellos, Maria B.A.

2000-01-01

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)

Cultivating Chlorella vulgaris and Scenedesmus quadricauda microalgae to degrade inorganic compounds and pesticides in water.

Science.gov (United States)

Baglieri, Andrea; Sidella, Sarah; Barone, Valeria; Fragalà, Ferdinando; Silkina, Alla; Nègre, Michèle; Gennari, Mara

2016-09-01

This work evaluates the possibility of cultivating Scenedesmus quadricauda and Chlorella vulgaris microalgae in wastewater from the hydroponic cultivation of tomatoes with the aim of purifying the water. S. quadricauda and C. vulgaris were also used in purification tests carried out on water contaminated by the following active ingredients: metalaxyl, pyrimethanil, fenhexamid, iprodione, and triclopyr. Fifty-six days after the inoculum was placed, a reduction was found in the concentration of nitric nitrogen, ammonia nitrogen, and soluble and total phosphorus. The decrease was 99, 83, 94, and 94 %, respectively, for C. vulgaris and 99, 5, 88, and 89 %, respectively, for S. quadricauda. When the microalgae were present, all the agrochemicals tested were removed more quickly from the water than from the sterile control (BG11). The increase in the rate of degradation was in the order metalaxyl > fenhexamid > iprodione > triclopyr > pyrimethanil. It was demonstrated that there was a real degradation of fenhexamid, metalaxyl, triclopyr, and iprodione, while in the case of pyrimethanil, the active ingredient removed from the substrate was absorbed onto the cells of the microalgae. It was also found that the agrochemicals used in the tests had no significant effect on the growth of the two microalgae. The experiment highlighted the possibility of using cultivations of C. vulgaris and S. quadricauda as purification systems for agricultural wastewater which contains eutrophic inorganic compounds such as nitrates and phosphates and also different types of pesticides.

Data on changes in red wine phenolic compounds, headspace aroma compounds and sensory profile after treatment of red wines with activated carbons with different physicochemical characteristics

Directory of Open Access Journals (Sweden)

Luís Filipe-Ribeiro

2017-06-01

Full Text Available Data in this article presents the changes on phenolic compounds, headspace aroma composition and sensory profile of a red wine spiked with 4-ethylphenol and 4-ethylguaiacol and treated with seven activated carbons with different physicochemical characteristics, namely surface area, micropore volume and mesopore volume (“Reduction of 4-ethylphenol and 4-ethylguaiacol in red wine by activated carbons with different physicochemical characteristics: impact on wine quality” Filipe-Ribeiro et al. (2017 [1]. Data on the physicochemical characteristics of the activated carbons are shown. Statistical data on the sensory expert panel consistency by General Procrustes Analysis is shown. Statistical data is also shown, which correlates the changes in chemical composition of red wines with the physicochemical characteristics of activated carbons used.

Data on changes in red wine phenolic compounds, headspace aroma compounds and sensory profile after treatment of red wines with activated carbons with different physicochemical characteristics.

Science.gov (United States)

Filipe-Ribeiro, Luís; Milheiro, Juliana; Matos, Carlos C; Cosme, Fernanda; Nunes, Fernando M

2017-06-01

Data in this article presents the changes on phenolic compounds, headspace aroma composition and sensory profile of a red wine spiked with 4-ethylphenol and 4-ethylguaiacol and treated with seven activated carbons with different physicochemical characteristics, namely surface area, micropore volume and mesopore volume ("Reduction of 4-ethylphenol and 4-ethylguaiacol in red wine by activated carbons with different physicochemical characteristics: impact on wine quality" Filipe-Ribeiro et al. (2017) [1]). Data on the physicochemical characteristics of the activated carbons are shown. Statistical data on the sensory expert panel consistency by General Procrustes Analysis is shown. Statistical data is also shown, which correlates the changes in chemical composition of red wines with the physicochemical characteristics of activated carbons used.

A Novel Method for Analysis of Dissolved Inorganic Carbon Concentration and δ13C by Cavity Ring-Down Spectroscopy

Science.gov (United States)

Smith, E.; Gonneea, M. E.; Boze, L. G.; Casso, M.; Pohlman, J.

2017-12-01

Dissolved inorganic carbon (DIC) is the largest pool of carbon in the oceans and is where about half of anthropogenic carbon dioxide (CO2) emissions are being sequestered. Determining the concentration and stable carbon isotopic content (δ13C) of DIC allows us to delineate carbon sources that contribute to marine DIC. A simple and reliable method for measuring DIC concentration and δ13C can be used to apportion contributions from external sources and identify effects from biogeochemical reactions that contribute or remove DIC. The U.S. Geological Survey has developed a discrete sample analysis module (DSAM) that interfaces to a Picarro G-2201i cavity ring-down spectrometer (CRDS, Picarro Inc.) to analyze CO2 and methane concentrations and δ13C from discrete gas samples. In this study, we adapted the USGS DSAM-CRDS analysis system to include an AutoMate prep device (Automate FX, Inc.) for analysis of DIC concentration and δ13C from aqueous samples. The Automate prep device was modified to deliver CO2 extracted from DIC to the DSAM, which conditions and transfers the gas to the CRDS. LabVIEW software (National Instruments) triggers the Automate Prep device, controls the DSAM and collects data from the CRDS. CO2 mass concentration data are obtained by numerical integration of the CO2 volumetric concentrations output by the CRDS and subsequent comparison to standard materials. CO2 carbon isotope values from the CRDS (iCO2) are converted to δ13C values using a slope and offset correction calibration procedure. The system design and operation was optimized using sodium bicarbonate (NaHCO3) standards and a certified reference material. Surface water and pore water samples collected from Sage Lot Pond, a salt marsh in Cape Cod MA, have been analyzed for concentration by coulometry and δ13C by isotope ratio mass spectrometry and will be used to validate the DIC-DSAM-CRDS method for field applications.

Inorganic insertion compounds under the form of Langmuir-Blodgett films

International Nuclear Information System (INIS)

Zylberajch, Claire

1989-01-01

As the study of organic or mineral compounds under the form of thin layers showed that they are displaying very original properties with respect to massive compounds, this research thesis reports a work which aimed at obtaining mineral conductive materials under the form of extremely thin layers, notably metallic sulfides of mercury and cadmium. Synthesis is performed in soft conditions within an organic matrix produced by using the Langmuir-Blodgett technique with successive diffusions of mineral reactants. Salt formation is monitored by infrared spectroscopy. Physical properties of these compounds have been studied by various techniques (UV, visible, and IR spectroscopy, linear dichroism, X ray diffraction, X ray photoelectron spectrometry, conduction, and so on). Structural and electronic properties of these extremely thin films confirm that metallic sulfides adopt a lamellar geometry with molecular thickness. Conductivity and photo-conductivity are interpreted by means of a conventional band diagram [fr

A novel lattice energy calculation technique for simple inorganic crystals

Energy Technology Data Exchange (ETDEWEB)

Kaya, Cemal [Department of Chemistry, Faculty of Science, Cumhuriyet University, 58140 Sivas (Turkey); Kaya, Savaş, E-mail: savaskaya@cumhuriyet.edu.tr [Department of Chemistry, Faculty of Science, Cumhuriyet University, 58140 Sivas (Turkey); Banerjee, Priyabrata [Surface Engineering and Tribology Group, CSIR-Central Mechanical Engineering Research Institute, Mahatma Gandhi Avenue, Durgapur 713209 (India)

2017-01-01

In this pure theoretical study, a hitherto unexplored equation based on Shannon radii of the ions forming that crystal and chemical hardness of any crystal to calculate the lattice energies of simple inorganic ionic crystals has been presented. To prove the credibility of this equation, the results of the equation have been compared with experimental outcome obtained from Born-Fajans-Haber- cycle which is fundamentally enthalpy-based thermochemical cycle and prevalent theoretical approaches proposed for the calculation of lattice energies of ionic compounds. The results obtained and the comparisons made have demonstrated that the new equation is more useful compared to other theoretical approaches and allows to exceptionally accurate calculation of lattice energies of inorganic ionic crystals without doing any complex calculations.

Weathering controls on mechanisms of carbon storage in grassland soils

Science.gov (United States)

Masiello, C.A.; Chadwick, O.A.; Southon, J.; Torn, M.S.; Harden, J.W.

2004-01-01

On a sequence of soils developed under similar vegetation, temperature, and precipitation conditions, but with variations in mineralogical properties, we use organic carbon and 14C inventories to examine mineral protection of soil organic carbon. In these soils, 14C data indicate that the creation of slow-cycling carbon can be modeled as occurring through reaction of organic ligands with Al3+ and Fe3+ cations in the upper horizons, followed by sorption to amorphous inorganic Al compounds at depth. Only one of these processes, the chelation Al3+ and Fe3+ by organic ligands, is linked to large carbon stocks. Organic ligands stabilized by this process traverse the soil column as dissolved organic carbon (both from surface horizons and root exudates). At our moist grassland site, this chelation and transport process is very strongly correlated with the storage and long-term stabilization of soil organic carbon. Our 14C results show that the mechanisms of organic carbon transport and storage at this site follow a classic model previously believed to only be significant in a single soil order (Spodosols), and closely related to the presence of forests. The presence of this process in the grassland Alfisol, Inceptisol, and Mollisol soils of this chronosequence suggests that this process is a more significant control on organic carbon storage than previously thought. Copyright 2004 by the American Geophysical Union.

Compound-specific radiocarbon analysis - Analytical challenges and applications

Science.gov (United States)

Mollenhauer, G.; Rethemeyer, J.

2009-01-01

Within the last decades, techniques have become available that allow measurement of isotopic compositions of individual organic compounds (compound-specific isotope measurements). Most often the carbon isotopic composition of these compounds is studied, including stable carbon (δ13C) and radiocarbon (Δ14C) measurements. While compound-specific stable carbon isotope measurements are fairly simple, and well-established techniques are widely available, radiocarbon analysis of specific organic compounds is a more challenging method. Analytical challenges include difficulty obtaining adequate quantities of sample, tedious and complicated laboratory separations, the lack of authentic standards for measuring realistic processing blanks, and large uncertainties in values of Δ14C at small sample sizes. The challenges associated with sample preparation for compound-specific Δ14C measurements will be discussed in this contribution. Several years of compound-specific radiocarbon analysis have revealed that in most natural samples, purified organic compounds consist of heterogeneous mixtures of the same compound. These mixtures could derive from multiple sources, each having a different initial reservoir age but mixed in the same terminal reservoir, from a single source but mixed after deposition, or from a prokaryotic organism using variable carbon sources including mobilization of ancient carbon. These processes not only represent challenges to the interpretation of compound-specific radiocarbon data, but provide unique tools for the understanding of biogeochemical and sedimentological processes influencing the preserved organic geochemical records in marine sediments. We will discuss some examples where compound-specific radiocarbon analysis has provided new insights for the understanding of carbon source utilization and carbon cycling.

Understanding the Burial and Migration Characteristics of Deep Geothermal Water Using Hydrogen, Oxygen, and Inorganic Carbon Isotopes

Directory of Open Access Journals (Sweden)

Xinyi Wang

2017-12-01

Full Text Available Geothermal water samples taken from deep aquifers within the city of Kaifeng at depths between 800 and 1650 m were analyzed for conventional water chemical compositions and stable isotopes. These results were then combined with the deuterium excess parameter (d value, and the contribution ratios of different carbon sources were calculated along with distributional characteristics and data on the migration and transformation of geothermal water. These results included the conventional water chemical group, hydrogen, and oxygen isotopes (δD-δ18O, dissolved inorganic carbon (DIC and associated isotopes (δ13CDIC. The results of this study show that geothermal water in the city of Kaifeng is weakly alkaline, water chemistry mostly comprises a HCO3-Na type, and the range of variation of δD is between −76.12‰ and −70.48‰, (average: −74.25‰, while the range of variation of δ18O is between −11.08‰ and −9.41‰ (average: −10.15‰. Data show that values of d vary between 1.3‰ and 13.3‰ (average: 6.91‰, while DIC content is between 91.523 and 156.969 mg/L (average: 127.158 mg/L. The recorded range of δ13CDIC was between −10.160‰ and −6.386‰ (average: −9.019‰. The results presented in this study show that as depth increases, so do δD and δ18O, while d values decrease and DIC content and δ13CDIC gradually increase. Thus, δD, δ18O, d values, DIC, and δ13CDIC can all be used as proxies for the burial characteristics of geothermal water. Because data show that the changes in d values and DIC content are larger along the direction of geothermal water flow, so these proxies can be used to indicate migration. This study also shows demonstrates that the main source of DIC in geothermal water is CO2thathas a biological origin in soils, as well as the dissolution of carbonate minerals in surrounding rocks. Thus, as depth increases, the contribution of soil biogenic carbon sources to DIC decreases while the influence

Modelling the ecosystem effects of nitrogen deposition: Model of Ecosystem Retention and Loss of Inorganic Nitrogen (MERLIN

Directory of Open Access Journals (Sweden)

B. J. Cosby

1997-01-01

Full Text Available A catchment-scale mass-balance model of linked carbon and nitrogen cycling in ecosystems has been developed for simulating leaching losses of inorganic nitrogen. The model (MERLIN considers linked biotic and abiotic processes affecting the cycling and storage of nitrogen. The model is aggregated in space and time and contains compartments intended to be observable and/or interpretable at the plot or catchment scale. The structure of the model includes the inorganic soil, a plant compartment and two soil organic compartments. Fluxes in and out of the ecosystem and between compartments are regulated by atmospheric deposition, hydrological discharge, plant uptake, litter production, wood production, microbial immobilization, mineralization, nitrification, and denitrification. Nitrogen fluxes are controlled by carbon productivity, the C:N ratios of organic compartments and inorganic nitrogen in soil solution. Inputs required are: 1 temporal sequences of carbon fluxes and pools- 2 time series of hydrological discharge through the soils, 3 historical and current external sources of inorganic nitrogen; 4 current amounts of nitrogen in the plant and soil organic compartments; 5 constants specifying the nitrogen uptake and immobilization characteristics of the plant and soil organic compartments; and 6 soil characteristics such as depth, porosity, bulk density, and anion/cation exchange constants. Outputs include: 1 concentrations and fluxes of NO3 and NH4 in soil solution and runoff; 2 total nitrogen contents of the organic and inorganic compartments; 3 C:N ratios of the aggregated plant and soil organic compartments; and 4 rates of nitrogen uptake and immobilization and nitrogen mineralization. The behaviour of the model is assessed for a combination of land-use change and nitrogen deposition scenarios in a series of speculative simulations. The results of the simulations are in broad agreement with observed and hypothesized behaviour of nitrogen

Preparation and use of maize tassels' activated carbon for the adsorption of phenolic compounds in environmental waste water samples.

Science.gov (United States)

Olorundare, O F; Msagati, T A M; Krause, R W M; Okonkwo, J O; Mamba, B B

2015-04-01

The determination and remediation of three phenolic compounds bisphenol A (BPA), ortho-nitrophenol (o-NTP), parachlorophenol (PCP) in wastewater is reported. The analysis of these molecules in wastewater was done using gas chromatography (GC) × GC time-of-flight mass spectrometry while activated carbon derived from maize tassel was used as an adsorbent. During the experimental procedures, the effect of various parameters such as initial concentration, pH of sample solution, eluent volume, and sample volume on the removal efficiency with respect to the three phenolic compounds was studied. The results showed that maize tassel produced activated carbon (MTAC) cartridge packed solid-phase extraction (SPE) system was able to remove the phenolic compounds effectively (90.84-98.49%, 80.75-97.11%, and 78.27-97.08% for BPA, o-NTP, and PCP, respectively). The MTAC cartridge packed SPE sorbent performance was compared to commercially produced C18 SPE cartridges and found to be comparable. All the parameters investigated were found to have a notable influence on the adsorption efficiency of the phenolic compounds from wastewaters at different magnitudes.

Inorganic Materials as Supports for Covalent Enzyme Immobilization: Methods and Mechanisms

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Paolo Zucca

2014-09-01

Full Text Available Several inorganic materials are potentially suitable for enzymatic covalent immobilization, by means of several different techniques. Such materials must meet stringent criteria to be suitable as solid matrices: complete insolubility in water, reasonable mechanical strength and chemical resistance under the operational conditions, the capability to form manageable particles with high surface area, reactivity towards derivatizing/functionalizing agents. Non-specific protein adsorption should be always considered when planning covalent immobilization on inorganic solids. A huge mass of experimental work has shown that silica, silicates, borosilicates and aluminosilicates, alumina, titania, and other oxides, are the materials of choice when attempting enzyme immobilizations on inorganic supports. More recently, some forms of elemental carbon, silicon, and certain metals have been also proposed for certain applications. With regard to the derivatization/functionalization techniques, the use of organosilanes through silanization is undoubtedly the most studied and the most applied, although inorganic bridge formation and acylation with selected acyl halides have been deeply studied. In the present article, the most common inorganic supports for covalent immobilization of the enzymes are reviewed, with particular focus on their advantages and disadvantages in terms of enzyme loadings, operational stability, undesired adsorption, and costs. Mechanisms and methods for covalent immobilization are also discussed, focusing on the most widespread activating approaches (such as glutaraldehyde, cyanogen bromide, divinylsulfone, carbodiimides, carbonyldiimidazole, sulfonyl chlorides, chlorocarbonates, N-hydroxysuccinimides.

Synthesis, crystal structure and growth of a new inorganic- organic hybrid compound for nonlinear optical applications: Aquadiiodo (3-aminopropanoic acid) cadmium (II)

Science.gov (United States)

Boopathi, K.; Babu, S. Moorthy; Jagan, R.; Ramasamy, P.

2017-12-01

The new inorganic-organic hybrid material aquadiiodo (3-aminopropanoic acid) cadmium (II) [ADI (3-AP) Cd] has been successfully synthesized and good quality crystals have been grown by slow evaporation solution technique. The structure was determined by single crystal X-ray diffraction at room temperature. The compound crystallizes in monoclinic crystal system with centro symmetric space group P21/c and four molecules in the unit cell. The structure of the title compound was further confirmed by 1H and 13C nuclear magnetic resonance spectral analysis. FT-IR spectroscopy was used to confirm the presence of various functional groups in the compound. The transmittance and optical parameters of the crystal were studied by UV- Visible-NIR spectroscopy. The thermal stability of the grown crystal was evaluated using thermogravimetric and differential thermal analyses. Mechanical hardness has been identified by Vickers micro hardness study and work hardening coefficient was calculated. Dielectric measurement was carried out as a function of frequency and results are discussed. The growth mechanism of the crystal was assessed by chemical etching studies. The third-order nonlinear optical susceptibility of [ADI (3-AP) Cd] was derived using the Z-scan technique, and it was 3.24955 × 10-8 esu. The positive nonlinear refractive index 2.48505 × 10-11 m2/W, is an indication of self-defocusing optical nonlinearity of the sample. It is believed that the [ADI (3-AP) Cd] is a promising new candidate for developing efficient nonlinear optical and optical power limiting devices.

Development of a Research-Oriented Inorganic Chemistry Laboratory Course

Science.gov (United States)

Vallarino, L. M.; Polo, D. L.; Esperdy, K.

2001-02-01

We report the development of a research-oriented, senior-level laboratory course in inorganic chemistry, which is a requirement for chemistry majors who plan to receive the ACS-approved Bachelor of Science degree and is a recommended elective for other chemistry majors. The objective of this course is to give all students the advantage of a research experience in which questions stemming from the literature lead to the formulation of hypotheses, and answers are sought through experiment. The one-semester Inorganic Chemistry Laboratory is ideal for this purpose, since for most students it represents the last laboratory experience before graduation and can assume the role of "capstone" course--a course where students are challenged to recall previously learned concepts and skills and put them into practice in the performance of an individual, original research project. The medium chosen for this teaching approach is coordination chemistry, a branch of chemistry that involves the interaction of inorganic and organic compounds and requires the use of various synthetic and analytical methods. This paper presents an outline of the course organization and requirements, examples of activities performed by the students, and a critical evaluation of the first five years' experience.

A novel method to prepare binary Ni-Fe compounds and ordered mesoporous carbon composite as a supercapacitor electrode

Energy Technology Data Exchange (ETDEWEB)

Feng, J.; Tang, B.; Zhao, J.; Liu, P.; Xu, J. [Shanghai Univ. of Engineering Science (China). College of Chemistry and Chemical Engineering

2010-07-01

Superapacitor electrodes with nickel/iron compounds and ordered mesoporous carbon (OMC) nanocomposites were fabricated using a incipient wetness impregnation and hydrothermal methods. The use of the nickel-iron compounds within the OMC framework resulted in a synergistic effect. Resistance was also improved. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) analyses demonstrated that the host structure was preserved during the impregnation and hydrothermal procedures. Nano-sized metal compounds were formed within the mesopore system. Nitrogen adsorption and desorption isotherm measurements demonstrated mesoporosity for the host/guest composites.

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

2015-01-01

“Clumped-isotope” thermometry is an emerging tool to probe the temperature history of surface and subsurface environments based on measurements of the proportion of 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

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

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.

Estimation of effect of inorganic salts on state of melts and carbamide solutions

International Nuclear Information System (INIS)

Dymnikov, N.S.; Yakunin, N.A.; Baranov, A.V.; Moryganov, A.P.

1995-01-01

The character of coordination in the systems carbamide-LiCl and carbamide-CaCl 2 has been shown on the basis of IR spectroscopy data. Interrelation between complexing in the melt carbamide-inorganic salt and thermal resistance of amide compound has been ascertained. 3 refs.; 3 figs

Inorganic nanostructured materials for high performance electrochemical supercapacitors

Science.gov (United States)

Liu, Sheng; Sun, Shouheng; You, Xiao-Zeng

2014-01-01

Electrochemical supercapacitors (ES) are a well-known energy storage system that has high power density, long life-cycle and fast charge-discharge kinetics. Nanostructured materials are a new generation of electrode materials with large surface area and short transport/diffusion path for ions and electrons to achieve high specific capacitance in ES. This mini review highlights recent developments of inorganic nanostructure materials, including carbon nanomaterials, metal oxide nanoparticles, and metal oxide nanowires/nanotubes, for high performance ES applications.

Solid phase extraction of hydroxyaromatic compounds from aquatic environment

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P. T. Sukhanov

2012-01-01

Full Text Available The dependence of extraction parameters of hydroxyaromatic compounds on sort of polyurethane foam, nature and composition of solution deposited on a polymer foam, content of inorganic salt in solution.

The Effect of Single, Binary and Ternary Anions of Chloride, Carbonate and Phosphate on the Release of 2,4-Dichlorophenoxyacetate Intercalated into the Zn–Al-layered Double Hydroxide Nanohybrid

Directory of Open Access Journals (Sweden)

Zainal Zulkarnain

2009-01-01

Full Text Available Abstract Intercalation of beneficial anion into inorganic host has lead to an opportunity to synthesize various combinations of new organic–inorganic nanohybrids with various potential applications; especially, for the controlled release formulation and storage purposes. Investigation on the release behavior of 2,4-dichlorophenoxyacetate (2,4-D intercalated into the interlayer of Zn–Al-layered double hydroxide (ZAN have been carried out using single, binary and ternary aqueous systems of chloride, carbonate and phosphate. The release behavior of the active agent 2,4-D from its double-layered hydroxide nanohybrid ZANDI was found to be of controlled manner governed by pseudo-second order kinetics. It was found that carbonate medium yielded the highest accumulated release of 2,4-D, while phosphate in combination with carbonate and/or nitrate speeds up the release rate of 2,4-D. These results indicate that it is possible to design and develop new delivery system of latex stimulant compound with controlled release property based on 2,4-D that is known as a substance to increase latex production of rubber tree,Hevea brasiliensis.

The Origin of Carbon-bearing Volatiles in Surprise Valley Hot Springs in the Great Basin: Carbon Isotope and Water Chemistry Characterizations

Science.gov (United States)

Fu, Qi; Socki, Richard A.; Niles, Paul B.; Romanek, Christopher; Datta, Saugata; Darnell, Mike; Bissada, Adry K.

2013-01-01

estimated by both dissolved SiO2 and Na-K-Ca geothermometers are in the range of 125.0 to 135.4 C, and higher than the values measured at orifices (77.3 to 90.0 C). CO2 and homologs of straight chain alkanes (C1-C5) were identified in gas samples. Carbon isotope values of alkanes increase with carbon numbers. The C-13 fractionation between CO2 and dissolved inorganic carbon suggests they are out of carbon isotope equilibrium. The hypothesis regarding the formation of carbon-bearing compounds in SVHS may involve two processes: 1) Under high heat flow conditions which are caused by regional faulting and crustal extension, original high molecular weight organic compounds (kerogens) in clay-rich rocks decomposed to generate methane and other alkane homologs. 2) The SVHS area is associated with outflow structures, and distant from the heat source. Anaerobic oxidation of methane (AOM) with sulfate at shallow depth (< 90 C) is suggested as being responsible for the generation of CO2 in SVHS.

Radiation effects on thermal decomposition of inorganic solids

International Nuclear Information System (INIS)

Dedgaonkar, V.G.

1985-01-01

Radiation effects on the thermal decomposition characteristics of inorganic oxyanions like permanganates, nitrates, zeolites and particularly ammonium perchlorate (AP) have been highlighted.The last compound finds wide application as an oxidizer in solid rocket propellents and although several hundred papers have been published on it during the last 30-40 years, most of which from the point of view of understanding and controlling the decomposition behaviour, there are only a few reports available in this area following the radiation treatment. (author)

HPLC inorganic arsenic speciation analysis of samples containing high sulfuric acid and iron levels

NARCIS (Netherlands)

Gonzalez-Contreras, P.A.; Gerrits, I.P.A.M.; Weijma, J.; Buisman, C.J.N.

2011-01-01

To monitor the oxidation of arsenite to arsenate in oxidizing and bioleaching reactors, speciation analysis of the inorganic arsenic compounds is required. Existing arsenic speciation analysis techniques are based on the use of liquid chromatography columns coupled to detector equipment such as

Carbon Sequestration in Terrestrial Ecosystems: A Status Report on R and D Progress

International Nuclear Information System (INIS)

Jacobs, G.K.

2001-01-01

Sequestration of carbon in terrestrial ecosystems is a low-cost option that may be available in the near-term to mitigate increasing atmospheric CO(sub 2) concentrations, while providing additional benefits. Storing carbon in terrestrial ecosystems can be achieved through maintenance of standing aboveground biomass, utilization of aboveground biomass in long-lived products, or protection of carbon (organic and inorganic) compounds present in soils. There are potential co-benefits from efforts to sequester carbon in terrestrial ecosystems. For example, long-lived valuable products (wood) are produced, erosion would be reduced, soil productivity could be improved through increased capacity to retain water and nutrients, and marginal lands could be improved and riparian ecosystems restored. Another unique feature of the terrestrial sequestration option is that it is the only option that is ''reversible'' should it become desirable or permissible. For example, forests that are created are thus investments which could be harvested should CO(sub 2) emissions be reduced in other ways to acceptable levels 50-100 years from now

Materials Chemistry and Performance of Silicone-Based Replicating Compounds.

Energy Technology Data Exchange (ETDEWEB)

Brumbach, Michael T.; Mirabal, Alex James; Kalan, Michael; Trujillo, Ana B; Hale, Kevin

2014-11-01

Replicating compounds are used to cast reproductions of surface features on a variety of materials. Replicas allow for quantitative measurements and recordkeeping on parts that may otherwise be difficult to measure or maintain. In this study, the chemistry and replicating capability of several replicating compounds was investigated. Additionally, the residue remaining on material surfaces upon removal of replicas was quantified. Cleaning practices were tested for several different replicating compounds. For all replicating compounds investigated, a thin silicone residue was left by the replica. For some compounds, additional inorganic species could be identified in the residue. Simple solvent cleaning could remove some residue.

In vitro erythemal UV-A protection factors of inorganic sunscreens distributed in aqueous media using carnauba wax-decyl oleate nanoparticles.

Science.gov (United States)

Villalobos-Hernández, J R; Müller-Goymann, C C

2007-01-01

This paper describes the in vitro photoprotection in the UV-A range, i.e. 320-400 nm obtained by the use of carnauba wax-decyl oleate nanoparticles either as encapsulation systems or as accompanying vehicles for inorganic sunscreens such as barium sulfate, strontium carbonate and titanium dioxide. Lipid-free inorganic sunscreen nanosuspensions, inorganic sunscreen-free wax-oil nanoparticle suspensions and wax-oil nanoparticle suspensions containing inorganic sunscreens dispersed either in their oil phase or their aqueous phase were prepared by high pressure homogenization. The in vitro erythemal UV-A protection factors (EUV-A PFs) of the nanosuspensions were calculated by means of a sun protection analyzer. EUV-A PFs being no higher than 4 were obtained by the encapsulation of barium sulfate and strontium carbonate, meanwhile by the distribution of titanium dioxide in presence of wax-oil nanoparticles, the EUV-A PFs varied between 2 and 19. The increase in the EUV-A PFs of the titanium dioxide obtained by the use of wax-oil nanoparticles demonstrated a better performance of the sun protection properties of this pigment in the UV-A region.

Organic and Inorganic Matter in Louisiana Coastal Waters: Vermilion, Atchafalaya, Terrebonne, Barataria, and Mississippi Regions.

Science.gov (United States)

Chromophoric dissolved organic matter (CDOM) spectral absorption, dissolved organic carbon (DOC) concentration, and the particulate fraction of inorganic (PIM) and organic matter (POM) were measured in Louisiana coastal waters at Vermilion, Atchafalaya, Terrebonne, Barataria, and...

Source apportionment of elevated wintertime PAHs by compound-specific radiocarbon analysis