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

PubMed

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).

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

NASA Astrophysics Data System (ADS)

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

Carbon balance in an irrigated corn field after inorganic fertilizer or manure application

USDA-ARS?s Scientific Manuscript database

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 an...

Manure and inorganic fertilizer effects on carbon balance and losses in irrigated corn

USDA-ARS?s Scientific Manuscript database

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 an...

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

NASA Astrophysics Data System (ADS)

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.

Storage/Turnover Rate of Inorganic Carbon and Its Dissolvable Part in the Profile of Saline/Alkaline Soils

PubMed Central

Wang, Yugang; Wang, Zhongyuan; Li, Yan

2013-01-01

Soil inorganic carbon is the most common form of carbon in arid and semiarid regions, and has a very long turnover time. However, little is known about dissolved inorganic carbon storage and its turnover time in these soils. With 81 soil samples taken from 6 profiles in the southern Gurbantongute Desert, China, we investigated the soil inorganic carbon (SIC) and the soil dissolved inorganic carbon (SDIC) in whole profiles of saline and alkaline soils by analyzing their contents and ages with radiocarbon dating. The results showed that there is considerable SDIC content in SIC, and the variations of SDIC and SIC contents in the saline soil profile were much larger than that in the alkaline profile. SDIC storage accounted for more than 20% of SIC storage, indicating that more than 1/5 of the inorganic carbon in both saline and alkaline soil is not in non-leachable forms. Deep layer soil contains considerable inorganic carbon, with more than 80% of the soil carbon stored below 1 m, whether for SDIC or SIC. More importantly, SDIC ages were much younger than SIC in both saline soil and alkaline soil. The input rate of SDIC and SIC ranged from 7.58 to 29.54 g C m-2 yr-1 and 1.34 to 5.33 g C m-2 yr-1 respectively for saline soil, and from 1.43 to 4.9 g C m-2 yr-1 and 0.79 to 1.27 g C m-2 yr-1respectively for alkaline soil. The comparison of SDIC and SIC residence time showed that using soil inorganic carbon to estimate soil carbon turnover would obscure an important fraction that contributes to the modern carbon cycle: namely the shorter residence and higher input rate of SDIC. This is especially true for SDIC in deep layers of the soil profile. PMID:24312399

Microalgal bacterial floc properties are improved by a balanced inorganic/organic carbon ratio.

PubMed

Van Den Hende, Sofie; Vervaeren, Han; Saveyn, Hans; Maes, Guy; Boon, Nico

2011-03-01

Microalgal bacterial floc (MaB-floc) reactors have been suggested as a more sustainable secondary wastewater treatment. We investigated whether MaB-flocs could be used as tertiary treatment. Tertiary influent has a high inorganic/organic carbon ratio, depending on the efficiency of the secondary treatment. In this study, the effect of this inorganic/organic carbon ratio on the MaB-flocs performance was determined, using three sequencing batch photobioreactors. The MaB-flocs were fed with synthetic wastewater containing 84, 42, and 0 mg L(-1) C-KHCO(3) supplemented with 0, 42, 84 mg L(-1) C-sucrose, respectively, representing inorganic versus organic carbon. Bicarbonate significantly decreased the autotrophic index of the MaB-flocs and resulted in poorly settling flocs. Moreover, sole bicarbonate addition led to a high pH of 9.5 and significant lower nitrogen removal efficiencies. Sucrose without bicarbonate resulted in good settling MaB-flocs, high nitrogen removal efficiencies and neutral pH levels. Despite the lower chlorophyll a content of the biomass and the lower in situ oxygen concentration, 92-96% of the soluble COD-sucrose was removed. This study shows that the inorganic/organic carbon ratio of the wastewater is of major importance and that organic carbon is requisite to guarantee a good performance of the MaB-flocs for wastewater treatment. Copyright © 2010 Wiley Periodicals, Inc.

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

NASA Astrophysics Data System (ADS)

Loyd, S. J.

2014-12-01

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

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

NASA Astrophysics Data System (ADS)

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.

Does Ocean Color Data Assimilation Improve Estimates of Global Ocean Inorganic Carbon?

NASA Technical Reports Server (NTRS)

Gregg, Watson

2012-01-01

Ocean color data assimilation has been shown to dramatically improve chlorophyll abundances and distributions globally and regionally in the oceans. Chlorophyll is a proxy for phytoplankton biomass (which is explicitly defined in a model), and is related to the inorganic carbon cycle through the interactions of the organic carbon (particulate and dissolved) and through primary production where inorganic carbon is directly taken out of the system. Does ocean color data assimilation, whose effects on estimates of chlorophyll are demonstrable, trickle through the simulated ocean carbon system to produce improved estimates of inorganic carbon? Our emphasis here is dissolved inorganic carbon, pC02, and the air-sea flux. We use a sequential data assimilation method that assimilates chlorophyll directly and indirectly changes nutrient concentrations in a multi-variate approach. The results are decidedly mixed. Dissolved organic carbon estimates from the assimilation model are not meaningfully different from free-run, or unassimilated results, and comparisons with in situ data are similar. pC02 estimates are generally worse after data assimilation, with global estimates diverging 6.4% from in situ data, while free-run estimates are only 4.7% higher. Basin correlations are, however, slightly improved: r increase from 0.78 to 0.79, and slope closer to unity at 0.94 compared to 0.86. In contrast, air-sea flux of C02 is noticeably improved after data assimilation. Global differences decline from -0.635 mol/m2/y (stronger model sink from the atmosphere) to -0.202 mol/m2/y. Basin correlations are slightly improved from r=O.77 to r=0.78, with slope closer to unity (from 0.93 to 0.99). The Equatorial Atlantic appears as a slight sink in the free-run, but is correctly represented as a moderate source in the assimilation model. However, the assimilation model shows the Antarctic to be a source, rather than a modest sink and the North Indian basin is represented incorrectly as a sink

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

NASA Astrophysics Data System (ADS)

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

2016-04-01

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

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

NASA Astrophysics Data System (ADS)

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

Simple and accurate method for determining dissolved inorganic carbon in environmental water by reaction headspace gas chromatography.

PubMed

Xie, Wei-Qi; Gong, Yi-Xian; Yu, Kong-Xian

2018-03-01

We investigate a simple and accurate method for quantitatively analyzing dissolved inorganic carbon in environmental water by reaction headspace gas chromatography. The neutralization reaction between the inorganic carbon species (i.e. bicarbonate ions and carbonate ions) in environmental water and hydrochloric acid is carried out in a sealed headspace vial, and the carbon dioxide formed from the neutralization reaction, the self-decomposition of carbonic acid, and dissolved carbon dioxide in environmental water is then analyzed by headspace gas chromatography. The data show that the headspace gas chromatography method has good precision (relative standard deviation ≤ 1.63%) and accuracy (relative differences ≤ 5.81% compared with the coulometric titration technique). The headspace gas chromatography method is simple, reliable, and can be well applied in the dissolved inorganic carbon detection in environmental water. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The transformation of inorganic sulfur compounds and the assimilation of organic and inorganic carbon by the sulfur disproportionating bacterium Desulfocapsa sulfoexigens.

PubMed

Frederiksen, Trine-Maria; Finster, Kai

2004-02-01

The physiology of the sulfur disproportionator Desulfocapsa sulfoexigens was investigated in batch cultures and in a pH-regulated continuously flushed fermentor system. It was shown that a sulphide scavanger in the form of ferric iron was not obligatory and that the control of pH allowed production of more biomass than was possible in carbonate buffered but unregulated batch cultures. Small amounts of sulphite were produced during disproportionation of elemental sulfur and thiosulphate. In addition, it was shown that in the presence of hydrogen, a respiratory type of process is favored before the disproportionation of sulphite, thiosulphate and elemental sulfur. Sulphate reduction was not observed. D. sulfoexigens assimilated inorganic carbon even in the presence of organic carbon sources. Inorganic carbon assimilation was probably catalyzed by the reverse CO-dehydrogenase pathway, which was supported by the constitutive expression of the gene encoding CO-dehydrogenase in cultures grown in the presence of acetate and by the high carbon fractionation values that are indicative of this pathway.

EFFECT OF CARBONIC ANHYDRASE INHIBITORS ON THE INORGANIC CARBON UPTAKE BY PHYTOPLANKTON NATURAL ASSEMBLAGES(1).

PubMed

Mercado, Jesús M; Ramírez, Teodoro; Cortés, Dolores; Liger, Esperanza

2009-02-01

The role of carbonic anhydrase (CA) in inorganic carbon acquisition (dissolved inorganic carbon, DIC) was examined in Alboran Sea phytoplankton assemblages. The study area was characterized by a relatively high variability in nutrient concentration and in abundance and taxonomic composition of phytoplankton. Therefore, the relationship between environmental variability and capacity for using HCO3 (-) via external CA (eCA) was examined. Acetazolamide (AZ, an inhibitor of eCA) inhibited the primary productivity (PP) in 50% of the samples, with inhibition percentages ranging from 13% to 60%. The AZ effect was more prominent in the samples that exhibited PP >1 mg C · m(-3)  · h(-1) , indicating that the contribution of eCA to the DIC photosynthetic flux was irrelevant at low PP. The inhibition of primary productivity by AZ was significantly correlated to the abundance of diatoms. However, there was no a relationship between AZ effect and CO2 partial pressure (pCO2 ) or nutrient concentration, indicating that the variability in the PP percentage supported by eCA was mainly due to differences in taxonomic composition of the phytoplankton assemblages. Ethoxyzolamide (EZ, an inhibitor of both external and internal CA) affected 13 of 14 analyzed samples, with PP inhibition percentages varying from 50% to 95%. The effects of AZ and EZ were partially reversed by doubling DIC concentration. These results imply that CA activity (external and/or internal) was involved in inorganic carbon acquisition in most the samples. However, EZ effect was not correlated with pCO2 or taxonomic composition of the phytoplankton. © 2009 Phycological Society of America.

Inorganic carbon and fossil organic carbon are source of bias for quantification of sequestered carbon in mine spoil

NASA Astrophysics Data System (ADS)

Vindušková, Olga; Frouz, Jan

2016-04-01

Carbon sequestration in mine soils has been studied as a possibility to mitigate the rising atmospheric CO2 levels and to improve mine soil quality (Vindu\\vsková and Frouz, 2013). Moreover, these soils offer an unique opportunity to study soil carbon dynamics using the chronosequence approach (using a set of sites of different age on similar parent material). However, quantification of sequestered carbon in mine soils is often complicated by fossil organic carbon (e.g., from coal or kerogen) or inorganic carbon present in the spoil. We present a methodology for quantification of both of these common constituents of mine soils. Our recommendations are based on experiments done on post-mining soils in Sokolov basin, Czech Republic. Here, fossil organic carbon is present mainly as kerogen Type I and II and represents 2-6 wt.% C in these soils. Inorganic carbon in these soils is present mainly as siderite (FeCO3), calcite (CaCO3), and dolomite (CaMg(CO3)2). All of these carbonates are often found in the overburden of coal seams thus being a common constituent of post-mining soils in the world. Vindu\\vsková O, Frouz J, 2013. Soil carbon accumulation after open-cast coal and oil shale mining in Northern Hemisphere: a quantitative review. ENVIRONMENTAL EARTH SCIENCES, 69: 1685-1698. Vindu\\vsková O, Dvořáček V, Prohasková A, Frouz J. 2014. Distinguishing recent and fossil organic matter - A critical step in evaluation of post-mining soil development - using near infrared spectroscopy. ECOLOGICAL ENGINEERING. 73: 643-648. Vindu\\vsková O, Sebag D, Cailleau G, Brus J, Frouz J. 2015. Methodological comparison for quantitative analysis of fossil and recently derived carbon in mine soils with high content of aliphatic kerogen. ORGANIC GEOCHEMISTRY, 89-90:14-22.

Inorganic nanotubes: One contribution of 12 to a Theme 'Nanotechnology of carbon and related materials'

NASA Astrophysics Data System (ADS)

Tenne, Reshef; Rao, C. N. R.

2004-10-01

Following the discovery of carbon fullerenes and carbon nanotubes, it was hypothesized that nanoparticles of inorganic compounds with layered (two-dimensional) structure, such as MoS2, will not be stable against folding and form nanotubes and fullerene-like structures: IF. The synthesis of numerous other inorganic nanotubes has been reported in recent years. Various techniques for the synthesis of inorganic nanotubes, including high-temperature reactions and strategies based on 'chemie douce' (soft chemistry, i.e. low-temperature) processes, are described. First-principle, density functional theory based calculations are able to provide substantial information on the structure and properties of such nanotubes. Various properties of inorganic nanotubes, including mechanical, electronic and optical properties, are described in brief. Some potential applications of the nanotubes in tribology, protection against impact, (photo)catalysis, batteries, etc., are discussed.

RAPID AND PRECISE METHOD FOR MEASURING STABLE CARBON ISOTOPE RATIOS OF DISSOLVED INORGANIC CARBON

EPA Science Inventory

We describe a method for rapid preparation, concentration and stable isotopic analysis of dissolved inorganic carbon (d13C-DIC). Liberation of CO2 was accomplished by placing 100 ?l phosphoric acid and 0.9 ml water in an evacuated 1.7-ml gas chromatography (GC) injection vial. Fo...

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

Treesearch

Daniel H. Doctor; Carol Kendall; Stephen D. Sebestyen; James B. Shanley; Nobuhito Ohte; Elizabeth W. Boyer

2008-01-01

The stable isotopic composition of dissolved inorganic carbon (δ13C-DIC) was investigated as a potential tracer of streamflow generation processes at the Sleepers River Research Watershed, Vermont, USA. Downstream sampling showed δ13C-DIC increased between 3-5% from the stream source to the outlet weir...

Bony fish and their contribution to marine inorganic carbon cycling

NASA Astrophysics Data System (ADS)

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

2016-04-01

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

Thermodynamic description of Tc(iv) solubility and carbonate complexation in alkaline NaHCO3-Na2CO3-NaCl systems.

PubMed

Baumann, A; Yalçıntaş, E; Gaona, X; Polly, R; Dardenne, K; Prüßmann, T; Rothe, J; Altmaier, M; Geckeis, H

2018-03-28

The solubility of 99 Tc(iv) was investigated in dilute to concentrated carbonate solutions (0.01 M ≤ C tot ≤ 1.0 M, with C tot = [HCO 3 - ] + [CO 3 2- ]) under systematic variation of ionic strength (I = 0.3-5.0 M NaHCO 3 -Na 2 CO 3 -NaCl-NaOH) and pH m (-log[H + ] = 8.5-14.5). Strongly reducing conditions (pe + pH m ≈ 2) were set with Sn(ii). Carbonate enhances the solubility of Tc(iv) in alkaline conditions by up to 3.5 log 10 -units compared to carbonate-free systems. Solvent extraction and XANES confirmed that Tc was kept as +IV during the timeframe of the experiments (≤ 650 days). Solid phase characterization performed by XAFS, XRD, SEM-EDS, chemical analysis and TG-DTA confirmed that TcO 2 ·0.6H 2 O(am) controls the solubility of Tc(iv) under the conditions investigated. Slope analysis of the solubility data in combination with solid/aqueous phase characterization and DFT calculations indicate the predominance of the species Tc(OH) 3 CO 3 - at pH m ≤ 11 and C tot ≥ 0.01 M, for which thermodynamic and activity models are derived. Solubility data obtained above pH m ≈ 11 indicates the formation of previously unreported Tc(iv)-carbonate species, possibly Tc(OH) 4 CO 3 2- , although the likely formation of additional complexes prevents deriving a thermodynamic model valid for this pH m -region. This work provides the most comprehensive thermodynamic dataset available for the system Tc 4+ -Na + -Cl - -OH - -HCO 3 - -CO 3 2- -H 2 O(l) valid under a range of conditions relevant for nuclear waste disposal.

Soil Inorganic Carbon Formation: Can Parent Material Overcome Climate?

NASA Astrophysics Data System (ADS)

Stanbery, C.; Will, R. M.; Seyfried, M. S.; Benner, S. G.; Flores, A. N.; Guilinger, J.; Lohse, K. A.; Good, A.; Black, C.; Pierce, J. L.

2014-12-01

Soil carbon is the third largest carbon reservoir and is composed of both organic and inorganic constituents. However, the storage and flux of soil carbon within the global carbon cycle are not fully understood. While organic carbon is often the focus of research, the factors controlling the formation and dissolution of soil inorganic carbon (SIC) are complex. Climate is largely accepted as the primary control on SIC, but the effects of soil parent material are less clear. We hypothesize that effects of parent material are significant and that SIC accumulation will be greater in soils formed from basalts than granites due to the finer textured soils and more abundant calcium and magnesium cations. This research is being conducted in the Reynolds Creek Experimental Watershed (RCEW) in southwestern Idaho. The watershed is an ideal location because it has a range of gradients in precipitation (250 mm to 1200 mm), ecology (sagebrush steppe to juniper), and parent materials (a wide array of igneous and sedimentary rock types) over a relatively small area. Approximately 20 soil profiles will be excavated throughout the watershed and will capture the effects of differing precipitation amounts and parent material on soil characteristics. Several samples at each site will be collected for analysis of SIC content and grain size distribution using a pressure calcimeter and hydrometers, respectively. Initial field data suggests that soils formed over basalts have a higher concentration of SIC than those on granitic material. If precipitation is the only control on SIC, we would expect to see comparable amounts in soils formed on both rock types within the same precipitation zone. However, field observations suggest that for all but the driest sites, soils formed over granite had no SIC detected while basalt soils with comparable precipitation had measurable amounts of SIC. Grain size distribution appears to be a large control on SIC as the sandier, granitic soils promote

Inorganic carbon addition stimulates snow algae primary productivity

NASA Astrophysics Data System (ADS)

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.

Inorganic nanotubes.

PubMed

Tenne, Reshef; Rao, C N R

2004-10-15

Following the discovery of carbon fullerenes and carbon nanotubes, it was hypothesized that nanoparticles of inorganic compounds with layered (two-dimensional) structure, such as MoS(2), will not be stable against folding and form nanotubes and fullerene-like structures: IF. The synthesis of numerous other inorganic nanotubes has been reported in recent years. Various techniques for the synthesis of inorganic nanotubes, including high-temperature reactions and strategies based on 'chemie douce' (soft chemistry, i.e. low-temperature) processes, are described. First-principle, density functional theory based calculations are able to provide substantial information on the structure and properties of such nanotubes. Various properties of inorganic nanotubes, including mechanical, electronic and optical properties, are described in brief. Some potential applications of the nanotubes in tribology, protection against impact, (photo)catalysis, batteries, etc., are discussed.

Seasonal Forcing of Summer Dissolved Inorganic Carbon and Chlorophyll a on the Western Shelf of the Antarctic Peninsula

DTIC Science & Technology

2010-03-30

Click Here for Full Article Seasonal forcing of summer dissolved inorganic carbon and chlorophyll a on the western shelf of the Antarctic Peninsula... season characterized by decreased spring sea ice cover or nearshore accumulation of phytoplankton in association with sea ice. The impact of these wind...Stammerjohn, and O. Schofield (2010), Seasonal forcing of summer dissolved inorganic carbon and chlorophyll a on the western shelf of the Antarctic

Carbon isotope signature of dissolved inorganic carbon (DIC) in precipitation and atmospheric CO2.

PubMed

Górka, Maciej; Sauer, Peter E; Lewicka-Szczebak, Dominika; Jędrysek, Mariusz-Orion

2011-01-01

This paper describes results of chemical and isotopic analysis of inorganic carbon species in the atmosphere and precipitation for the calendar year 2008 in Wrocław (SW Poland). Atmospheric air samples (collected weekly) and rainwater samples (collected after rain episodes) were analysed for CO2 and dissolved inorganic carbon (DIC) concentrations and for δ13C composition. The values obtained varied in the ranges: atmospheric CO2: 337-448 ppm; δ13CCO2 from -14.4 to -8.4‰; DIC in precipitation: 0.6-5.5 mg dm(-3); δ13CDIC from -22.2 to +0.2‰. No statistical correlation was observed between the concentration and δ13C value of atmospheric CO2 and DIC in precipitation. These observations contradict the commonly held assumption that atmospheric CO2 controls the DIC in precipitation. We infer that DIC is generated in ambient air temperatures, but from other sources than the measured atmospheric CO2. The calculated isotopic composition of a hypothetical CO2 source for DIC forming ranges from -31.4 to -11.0‰, showing significant seasonal variations accordingly to changing anthropogenic impact and atmospheric mixing processes. Copyright © 2010 Elsevier Ltd. All rights reserved.

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

NASA Astrophysics Data System (ADS)

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.

[Correlation Among Soil Organic Carbon, Soil Inorganic Carbon and the Environmental Factors in a Typical Oasis in the Southern Edge of the Tarim Basin].

PubMed

Gong, Lu; Zhu, Mei-ling; Liu, Zeng-yuan; Zhang, Xue-ni; Xie, Li-na

2016-04-15

We analyzed the differentiation among the environmental factors and soil organic/inorganic carbon contents of irrigated desert soil, brown desert soil, saline soil and aeolian sandy soil by classical statistics methods, and studied the correlation between soil carbon contents and the environmental factor by redundancy analysis (RDA) in a typical oasis of Yutian in the southern edge of the Tarim Basin. The results showed that the average contents of soil organic carbon and soil inorganic carbon were 2.51 g · kg⁻¹ and 25.63 g · kg⁻¹ respectively. The soil organic carbon content of the irrigated desert soil was significantly higher than those of brown desert soil, saline soil and aeolian sandy soil, while the inorganic carbon content of aeolian sandy soil was significantly higher than those of other soil types. The soil moisture and nutrient content were the highest in the irrigated desert soil and the lowest in the aeolian sandy sail. All soil types had high degree of salinization except the irrigated desert soil. The RDA results showed that the impacts of environmental factors on soil carbon contents ranked in order of importance were total nitrogen > available phosphorus > soil moisture > ground water depth > available potassium > pH > total salt. The soil carbon contents correlated extremely significantly with total nitrogen, available phosphorus, soil moisture and ground water depth (P < 0.01), and it correlated significantly with available potassium and pH (P < 0.05). There was no significant correlation between soil carbon contents and other environmental factors (P > 0.05).

[Exchange Fluxes and Coupling Relationship of Dissolved Inorganic Carbon and Dissolved Organic Carbon Across the Water-Sediment Interface in Lakes].

PubMed

Wang, Wei-ying; Lü, Chang-wei; He, Jiang; Zuo, Le; Yan, Dao-hao

2015-10-01

In this work, the exchange fluxes and coupling relationship of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) were investigated across the water-sediment interface in Lake Wuliangsuhai and Daihai by employing columnar simulation method. The results showed that the sediments in non-Phragmitescommunis area from Lake Wuliangsuhai functioned as the sources of DIC and DOC for overlying water, whereas the sediments from Lake Daihai as the sinks during the period of summer (90 days). In the experimental period, the average exchange rates of DIC and DOC were 71.07 mmol x (m2 x d)(-1) and 185.09 mmol x (m2 x d)(-1) in non-Phragmitescommunis area from Lake Wuliangsuhai, respectively; while in Lake Daihai, they were 155.75 mmol x (m2 x d)(-1) and -1478.08 mmol x (m2 x d)(-1) in shoal water zone, and -486.53 mmol x (m2 x d)(-1) and -1274.02 mmol x (m2 x d)(-1) in deep water zone, respectively. The coupling effects between DIC and DOC were governed by hydrobios, microbial uptake, abiotic and microbiological degradation in Lake Wuliangsuhai and in shoal water zone of Lake Daihai; while they were closely related to the coprecipitation process of CaCO3 and the fraction distribution of inorganic carbon in sediments in deep water zone of Lake Daihai. In summary, the sink or source functions of sediments could be considered as the results of synthetic action of lake types, offshore distance, geohydrochemistry and the fraction distribution of inorganic carbon.

Seasonal variations of stable carbon isotopic composition of bulk aerosol carbon from Gosan site, Jeju Island in the East China Sea

NASA Astrophysics Data System (ADS)

Kundu, Shuvashish; Kawamura, Kimitaka

2014-09-01

This study explores the usefulness of stable isotopic composition (δ13C) along with other chemical tracers and air mass trajectory to identify the primary and secondary sources of carbonaceous aerosols. Aerosol samples (n = 84) were collected continuously from April 2003 to April 2004 at Gosan site in Jeju Island, South Korea. The concentrations of total carbon (TC), HCl fumed carbonate-free total carbon (fumed-TC) and their δ13C were measured online using elemental analyzer interfaced to isotope ratio mass spectrometer (EA-IRMS). Similar concentrations of TC and fumed-TC and their similar δ13C values suggest the insignificant contribution of inorganic carbon to Gosan aerosols. The monthly averaged δ13CTC showed the lowest in April/May (-24.2 to -24.4‰), which is related with the highest concentrations of oxalic acid (a secondary tracer). The result indicates an enhanced contribution of TC from secondary sources. The monthly averaged δ13CTC in July/August (-23.0 to -22.5‰) were similar to those in January/February (-23.1‰ to -22.7‰). However, chemical tracers and air mass transport pattern suggest that the pollution source regions in January/February are completely different from those in July/August. Higher δ13C values in July/August are aligned with higher concentration ratios of marine tracers (azelaic acid/TC and methanesulfonate/TC), suggesting an enhanced contribution of marine organic matter to the aerosol loading. Higher δ13C values in January/February are associated with higher concentrations of phthalic acid and K+/TC, indicating more contributions of carbonaceous aerosols from fossil fuel and C4-plant biomass combustion. This study demonstrates that δ13CTC, along with other chemical tracers and air mass trajectory, can be used as a tracer to understand the importance of primary versus secondary pollution sources of carbonaceous aerosols in the atmosphere.

Inorganic carbon loading as a primary driver of dissolved carbon dioxide concentrations in the lakes and reservoirs of the contiguous United States

USGS Publications Warehouse

McDonald, Cory P.; Stets, Edward; Striegl, Robert G.; Butman, David

2013-01-01

Accurate quantification of CO2 flux across the air-water interface and identification of the mechanisms driving CO2 concentrations in lakes and reservoirs is critical to integrating aquatic systems into large-scale carbon budgets, and to predicting the response of these systems to changes in climate or terrestrial carbon cycling. Large-scale estimates of the role of lakes and reservoirs in the carbon cycle, however, typically must rely on aggregation of spatially and temporally inconsistent data from disparate sources. We performed a spatially comprehensive analysis of CO2 concentration and air-water fluxes in lakes and reservoirs of the contiguous United States using large, consistent data sets, and modeled the relative contribution of inorganic and organic carbon loading to vertical CO2 fluxes. Approximately 70% of lakes and reservoirs are supersaturated with respect to the atmosphere during the summer (June–September). Although there is considerable interregional and intraregional variability, lakes and reservoirs represent a net source of CO2 to the atmosphere of approximately 40 Gg C d–1 during the summer. While in-lake CO2 concentrations correlate with indicators of in-lake net ecosystem productivity, virtually no relationship exists between dissolved organic carbon and pCO2,aq. Modeling suggests that hydrologic dissolved inorganic carbon supports pCO2,aq in most supersaturated systems (to the extent that 12% of supersaturated systems simultaneously exhibit positive net ecosystem productivity), and also supports primary production in most CO2-undersaturated systems. Dissolved inorganic carbon loading appears to be an important determinant of CO2concentrations and fluxes across the air-water interface in the majority of lakes and reservoirs in the contiguous United States.

Underscoring the influence of inorganic chemistry on nuclear imaging with radiometals.

PubMed

Zeglis, Brian M; Houghton, Jacob L; Evans, Michael J; Viola-Villegas, Nerissa; Lewis, Jason S

2014-02-17

Over the past several decades, radionuclides have matured from largely esoteric and experimental technologies to indispensible components of medical diagnostics. Driving this transition, in part, have been mutually necessary advances in biomedical engineering, nuclear medicine, and cancer biology. Somewhat unsung has been the seminal role of inorganic chemistry in fostering the development of new radiotracers. In this regard, the purpose of this Forum Article is to more visibly highlight the significant contributions of inorganic chemistry to nuclear imaging by detailing the development of five metal-based imaging agents: (64)Cu-ATSM, (68)Ga-DOTATOC, (89)Zr-transferrin, (99m)Tc-sestamibi, and (99m)Tc-colloids. In a concluding section, several unmet needs both in and out of the laboratory will be discussed to stimulate conversation between inorganic chemists and the imaging community.

Underscoring the Influence of Inorganic Chemistry on Nuclear Imaging with Radiometals

PubMed Central

Zeglis, Brian M.; Houghton, Jacob L.; Evans, Michael J.; Viola-Villegas, Nerissa; Lewis, Jason S.

2014-01-01

Over the past several decades, radionuclides have matured from largely esoteric and experimental technologies to indispensible components of medical diagnostics. Driving this transition, in part, have been mutually necessary advances in biomedical engineering, nuclear medicine, and cancer biology. Somewhat unsung has been the seminal role of inorganic chemistry in fostering the development of new radiotracers. In this regard, the purpose of this Forum Article is to more visibly highlight the significant contributions of inorganic chemistry to nuclear imaging by detailing the development of five metal-based imaging agents: 64Cu-ATSM, 68Ga-DOTATOC, 89Zr-transferrin, 99mTc-sestamibi, and 99mTc-colloids. In a concluding section, several unmet needs both in and out of the laboratory will be discussed to stimulate conversation between inorganic chemists and the imaging community. PMID:24313747

Time-resolved distributions of bulk parameters, diacids, ketoacids and α-dicarbonyls and stable carbon and nitrogen isotope ratios of TC and TN in tropical Indian aerosols: Influence of land/sea breeze and secondary processes

NASA Astrophysics Data System (ADS)

Pavuluri, Chandra Mouli; Kawamura, Kimitaka; Swaminathan, T.

2015-02-01

To better understand the photochemical production and diurnal distributions of organic and inorganic aerosols in the tropical coastal Indian atmosphere, the aerosol (TSP) samples were collected every 3 h during 30-31 January, 14-15 February and 28-29 May 2007 from Chennai and studied for total carbon (TC) and nitrogen (TN) and their stable isotope ratios (δ13CTC and δ15NTN), carbonaceous components, inorganic ions, diacids, ketoacids and α-dicarbonyls. Time-resolved distributions of bulk parameters, inorganic ions, and diacids and related compounds, except for few species, did not show any clear diurnal trend but showed peaks at 6-9 h during all the study periods, except for the peak at 15-18 h on 28 May. SO42-, C2 - C6 diacids, ketoacids and α-dicarbonyls in February and on 29 May showed a diurnal trend. δ13CTC and δ15NTN stayed relatively constant during the study periods but showed 13C depletion (in January) and 15 N enrichment when TC and TN peaked. Based on these results together with air mass trajectories, we found that the diurnal distributions of Chennai aerosols are mainly influenced by land/sea breeze and the aged (photochemically processed) air masses, although in situ photochemical production and nighttime chemistry of secondary aerosol species, particularly C2-C4 diacids and SO42-, are significant. The characteristics of seasonal variations of carbonaceous components, and diacids and related compounds and comparisons of δ13CTC and δ15NTN of Chennai aerosols with the isotopic signatures of the point sources inferred that biofuel/biomass burning in South and Southeast Asia are the major sources of aerosols (TSP).

Nitrogen recovery from wastewater using gas-permeable membranes: Impact of inorganic carbon content and natural organic matter.

PubMed

Daguerre-Martini, S; Vanotti, M B; Rodriguez-Pastor, M; Rosal, A; Moral, R

2018-06-15

Gas-permeable membranes coupled with low-rate aeration is useful to recover ammonia (NH 4 + ) from livestock effluents. In this study, the role of inorganic carbon (bicarbonate, HCO 3 - ) to enhance the N recovery process was evaluated using synthetic effluents with various NH 4 + to HCO 3 - molar ratios of 0.5, 1.0, 1.5 and 2.0. The study also evaluated the effect of increased organic matter on the NH 4 + recovery using humic acids (3000-6000 mg L -1 ), and the N recovery from high-strength swine manure. The release of hydroxide from the HCO 3 - with aeration increased the wastewater pH and promoted gaseous ammonia formation and membrane uptake. At the same time, the recovery of gaseous ammonia (NH 3 ) through the membrane acidified the wastewater. Therefore, an abundant inorganic carbon supply in balance with the NH 4 + is needed for a successful operation of the technology. NH 4 + removal efficiencies >96% were obtained with NH 4 + to HCO 3 - ratios ≤1. However, higher molar ratios inhibited the N recovery process resulting in lower efficiencies (<65%). Fortunately, most swine manures contain ample supply of endogenous inorganic carbon and the process can be used to more economically recover the ammonia using the natural inorganic carbon instead of expensive alkali chemicals. In 4 days, the recovered NH 4 + from swine manure contained 48,000 mg L -1 . Finally, it was found the process was not inhibited by the increasing levels of organic matter in the wastewater evaluated. Published by Elsevier Ltd.

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

NASA Astrophysics Data System (ADS)

Giesbrecht, K. E.; Miller, L. A.; Davelaar, M.; Zimmermann, S.; Carmack, E.; Johnson, W. K.; Macdonald, R. W.; McLaughlin, F.; Mucci, A.; Williams, W. J.; Wong, C. S.; Yamamoto-Kawai, M.

2014-03-01

We have assembled and conducted primary quality control on previously publicly unavailable water column measurements of the dissolved inorganic carbon system and associated biogeochemical parameters (oxygen, nutrients, etc.) made on 26 cruises in the subarctic and Arctic regions dating back to 1974. The measurements are primarily from the western side of the Canadian Arctic, but also include data that cover an area ranging from the North Pacific to the Gulf of St. Lawrence. The data were subjected to primary quality control (QC) to identify outliers and obvious errors. This data set incorporates over four thousand individual measurements of total inorganic carbon (TIC), alkalinity, and pH from the Canadian Arctic over a period of more than 30 years and provides an opportunity to increase our understanding of temporal changes in the inorganic carbon system in northern waters and the Arctic Ocean. The data set is available for download on the CDIAC (Carbon Dioxide Information Analysis Center) website: http://cdiac.ornl.gov/ftp/oceans/IOS_Arctic_Database/ (doi:10.3334/CDIAC/OTG.IOS_ARCT_CARBN).

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

NASA Astrophysics Data System (ADS)

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.

Fluxes of inorganic carbon from two forested catchments in the Appalachian mountains

Treesearch

Fred Worrall; Wayne T. Swank; Tim Burt

2005-01-01

This study uses long-term records of stream chemistry, discharge and air temperature from two neighbouring forested catchments in the southern Appalachians in order to calculate production of dissolved C02 and dissolved inorganic carbon (DIC). One of the pair of catchments was clear-felled during the period of the study. The study shows that: (1...

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schneider, Kenneth; Silverman, Jacob; Kravitz, Benjamin S.

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 weremore » 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.« less

Influences of terrestrial inorganic carbon on carbonate system in China Seas and the implication for China Seas' vulnerabilities to potentially negative effects of ocean acidification

NASA Astrophysics Data System (ADS)

Guo, X.; Zhai, W. D.; Guo, L. G.; Jiang, Z. P.; Qi, D.; Xu, Y.; Huang, X.

2017-12-01

We investigated sea surface carbonate system and ancillary parameters in the northern South China Sea (SCS), East China Sea (ECS), Yellow Sea, and Bohai Sea during a single cruise from late April to June 2011. In this transitional season between the dry/cold and wet/warm seasons, we observed ubiquitous terrestrial inorganic carbon signals in the Yellow Sea and Bohai Sea, as indicated by excess total alkalinity (TAlk) from 150 to 450 μmol kg-1 and excess Ca concentrations from 100 to 470 μmol kg-1, associated with relatively high DIC/TAlk ratios from 0.88 to 0.92. In contrast, these terrestrial inorganic carbon signals were limited to nearshore areas in the southern ECS and northern SCS. These results suggested that the Yellow Sea and Bohai Sea were dominated by terrestrial inputs all over the year, while the terrestrial signals in the southern ECS and northern SCS were highly diminished in dry seasons through water mixing with open ocean waters (likely introduced by Kuroshio). This study also showed that the terrestrial inorganic carbon inputs had diminished carbonate ion concentrations and CaCO3 saturation states in the Yellow Sea and Bohai Sea. This may contribute to recent findings that the North Yellow Sea represents one of the systems in the China seas most vulnerable to the potentially negative effects of ocean acidification.

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

USGS Publications Warehouse

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)

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

NASA Astrophysics Data System (ADS)

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

NASA Astrophysics Data System (ADS)

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 (<100 sq-km) 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

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

NASA Astrophysics Data System (ADS)

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.

THE EFFECT OF PH AND DISSOLVED INORGANIC CARBON ON THE PROPERTIES OF IRON COLLOIDAL SUSPENSIONS

EPA Science Inventory

Discolored water resulting from suspended iron particles is a relatively common drinking water consumer complaint. These particles result from the oxygenation of Fe(II), and this study shows that pH and dissolved inorganic carbon (DIC) have important effects on their properties....

The Role of Stream Water Carbon Dynamics and Export in the Carbon Balance of a Tropical Seasonal Rainforest, Southwest China

PubMed Central

Zhou, Wen-Jun; Zhang, Yi-Ping; Schaefer, Douglas A.; Sha, Li-Qing; Deng, Yun; Deng, Xiao-Bao; Dai, Kai-Jie

2013-01-01

A two-year study (2009 ∼ 2010) was carried out to investigate the dynamics of different carbon (C) forms, and the role of stream export in the C balance of a 23.4-ha headwater catchment in a tropical seasonal rainforest at Xishuangbanna (XSBN), southwest China. The seasonal volumetric weighted mean (VWM) concentrations of total inorganic C (TIC) and dissolved inorganic C (DIC) were higher, and particulate inorganic C (PIC) and organic C (POC) were lower, in the dry season than the rainy season, while the VWM concentrations of total organic C (TOC) and dissolved organic C (DOC) were similar between seasons. With increased monthly stream discharge and stream water temperature (SWT), only TIC and DIC concentrations decreased significantly. The most important C form in stream export was DIC, accounting for 51.8% of the total C (TC) export; DOC, POC, and PIC accounted for 21.8%, 14.9%, and 11.5% of the TC export, respectively. Dynamics of C flux were closely related to stream discharge, with the greatest export during the rainy season. C export in the headwater stream was 47.1 kg C ha−1 yr−1, about 2.85% of the annual net ecosystem exchange. This finding indicates that stream export represented a minor contribution to the C balance in this tropical seasonal rainforest. PMID:23437195

The role of stream water carbon dynamics and export in the carbon balance of a tropical seasonal rainforest, southwest China.

PubMed

Zhou, Wen-Jun; Zhang, Yi-Ping; Schaefer, Douglas A; Sha, Li-Qing; Deng, Yun; Deng, Xiao-Bao; Dai, Kai-Jie

2013-01-01

A two-year study (2009 ~ 2010) was carried out to investigate the dynamics of different carbon (C) forms, and the role of stream export in the C balance of a 23.4-ha headwater catchment in a tropical seasonal rainforest at Xishuangbanna (XSBN), southwest China. The seasonal volumetric weighted mean (VWM) concentrations of total inorganic C (TIC) and dissolved inorganic C (DIC) were higher, and particulate inorganic C (PIC) and organic C (POC) were lower, in the dry season than the rainy season, while the VWM concentrations of total organic C (TOC) and dissolved organic C (DOC) were similar between seasons. With increased monthly stream discharge and stream water temperature (SWT), only TIC and DIC concentrations decreased significantly. The most important C form in stream export was DIC, accounting for 51.8% of the total C (TC) export; DOC, POC, and PIC accounted for 21.8%, 14.9%, and 11.5% of the TC export, respectively. Dynamics of C flux were closely related to stream discharge, with the greatest export during the rainy season. C export in the headwater stream was 47.1 kg C ha(-1) yr(-1), about 2.85% of the annual net ecosystem exchange. This finding indicates that stream export represented a minor contribution to the C balance in this tropical seasonal rainforest.

Measurement of organic and elemental carbon in downtown Rome and background area: physical behavior and chemical speciation.

PubMed

Avino, Pasquale; Manigrasso, Maurizio; Rosada, Alberto; Dodaro, Alessandro

2015-02-01

A significant portion of the particulate matter is the total carbonaceous fraction (or total carbon, TC), composed of two main fractions, elemental carbon (EC) and organic carbon (OC), which shows a large variety of organic compounds, e.g. aliphatic, aromatic compounds, alcohols, acids, etc. In this paper, TC, EC and OC concentrations determined in a downtown Rome urban area are discussed considering the influence of meteorological conditions on the temporal-spatial aerosol distribution. Similar measurements were performed at ENEA Casaccia, an area outside Rome, which is considered as the ome background. Since 2000, TC, EC and OC measurements have been performed by means of an Ambient Carbon Particulate Monitor equipped with a NDIR detector. The EC and OC concentrations trends are compared with benzene and CO trends, which are specific indicators of autovehicular traffic, for identifying the primary EC and OC contributions and the secondary OC fraction origin. Further, a chemical investigation is reported for investigating how the main organic (i.e., n-alkanes, n-alkanoic acids, polyaromatic hydrocarbons and nitro-polyaromatic hydrocarbons) and inorganic (i.e., metals, ions) fractions vary their levels during the investigated period in relationship to new regulations and/or technological innovations.

Dissolved inorganic carbon isotopic composition of the Gulf of Mexico deep-water masses.

NASA Astrophysics Data System (ADS)

Quintanilla-Terminel, J. G.; Herguera, J. C.; Ferreira-Bartrina, V.; Hernández-Ayón, J. M.; Camacho-Ibar, V.

2014-12-01

This study provides new data for the establishment of a carbon biogeochemical dynamics baseline in the deep Gulf of Mexico (GM) based on carbon isotopes in dissolved inorganic carbon. Water samples from 40 deep-water stations south of 25˚N were collected during XIXIMI-2 cruise, July 2011, aboard BO/Justo Sierra. Vertical profiles of temperature, salinity and dissolved oxygen (DO) were further measured in each station. In the Stable Isotopes Laboratory at CICESE we determined the carbon isotopic composition of the dissolved inorganic carbon (DIC) (δ13CDIC). Remarkably, density, DO and δ13CCID profiles showed a clear difference between the Loop current and the deep-waters of the GM south of 25˚N. We found the following average δ13CCID values in the Loop current and in the deep-waters of the Gulf: subtropical underwater (SUW): 0.73±0.06‰ and 0.86±0.04‰; 18 degree water (18W): 0.76 ± 0.08‰ and 0.58± 0.06‰; North Atlantic central water (NACW): 0.77 ± 0.05‰ and 0.71 ± 0.09‰; South Atlantic central water (SACW): 0.80 ± 0.08‰ and 0.77 ± 0.07‰; Antartic intermediate water (AAIW): 1.00 ± 0.06‰ and 0.90 ± 0.08‰; North Atlantic deep water (NADW): 1.03 ± 0.06‰ and 1.01 ± 0.10‰. We will discuss how the biological component, δ13CCID-BIO, of subsurface water masses match very closely the apparent oxygen utilization relation described by Kroopnick, 1985, with the exception of SUW, and as a consequence the 18W is probably the water mass most affected by organic carbon remineralization processes in the GM south of 25˚N. We further show how these waters seem to store a larger proportion of anthropogenic carbon than the deeper water masses.

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

NASA Astrophysics Data System (ADS)

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

Measuring oxygen yields of a thermal conversion/elemental analyzer-isotope ratio mass spectrometer for organic and inorganic materials through injection of CO.

PubMed

Yin, Xijie; Chen, Zhigang

2014-12-01

The thermal conversion/elemental analyzer-isotope ratio mass spectrometer (TC/EA-IRMS) is widely used to measure the δ(18) O value of various substances. A premise for accurate δ(18) O measurement is that the oxygen in the sample can be converted into carbon monoxide (CO) quantitatively or at least proportionally. Therefore, a precise method to determine the oxygen yield of TC/EA-IRMS measurements is needed. Most studies have used the CO peak area obtained from a known amount of a solid reference material (for example, benzoic acid) to calibrate the oxygen yield of the sample. Although it was assumed that the oxygen yield of the solid reference material is 100%, no direct evidence has been provided. As CO is the analyte gas for δ(18) O measurement by IRMS, in this study, we use a six-port valve to inject CO gas into the TC/EA. The CO is carried to the IRMS by the He carrier gas and the CO peak area is measured by the IRMS. The CO peak area thus obtained from a known amount of the injected CO is used to calibrate the oxygen yield of the sample. The oxygen yields of commonly used organic and inorganic reference materials such as benzoic acid (C6 H5 COOH), silver phosphate (Ag3 PO4 ), calcium carbonate (CaCO3 ) and silicon dioxide (SiO2 ) are investigated at different reactor temperatures and sample sizes. We obtained excellent linear correlation between the peak area for the injected CO and its oxygen atom amount. C6 H5 COOH has the highest oxygen yield, followed by Ag3 PO4 , CaCO3 and SiO2 . The oxygen yields of TC/EA-IRMS are less than 100% for both organic and inorganic substances, but the yields are relatively stable at the specified reactor temperature and for a given quantity of sample. Copyright © 2014 John Wiley & Sons, Ltd.

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

NASA Astrophysics Data System (ADS)

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

2015-04-01

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

Inorganic Carbon and Oxygen Dynamics in a Marsh-dominated Estuary

NASA Astrophysics Data System (ADS)

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.

In situ spectrophotometric measurement of dissolved inorganic carbon in seawater

USGS Publications Warehouse

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.

In situ spectrophotometric measurement of dissolved inorganic carbon in seawater.

PubMed

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

2013-10-01

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.

Preliminary Earth System Modeling (cGENIE) of Paired Organic and Inorganic Carbon Isotope Records to Investigate Carbon Cycle Behavior During the Triassic-Jurassic Transition

NASA Astrophysics Data System (ADS)

Yager, J. A.; Stellmann, J. L.; West, A. J.; Corsetti, F. A.; Berelson, W.; Bottjer, D. J.; Rosas, S.

2016-12-01

The stable C isotope composition of marine carbonate and organic C yields information regarding major changes in global carbon cycling over geologic time. Excursions from baseline C isotope compositions during the Late Triassic and early Jurassic coincide with the end-Triassic mass extinction. Much remains to be understood about the global extent of these excursions, and about their causes. Here, we use observations from a record from Northern Peru (Levanto) to generate hypotheses concerning C cycle changes, focusing on comparison to other sections spanning the Triassic-Jurassic boundary. Our observations include a decoupling between organic and inorganic C isotopes in some records, broad similarities in the pattern of excursions between sections, and a potential offset between the major ocean basins (Tethys and Panthalassa) in both inorganic and organic C isotope records. We are currently adapting a spatially resolved Earth System Model (cGENIE) for this time period with the goal of using this model to explore possible mechanistic causes of these observations, aiming to tie the C isotope records to changes in global carbon cycle dynamics at the time.

Photosynthetic use of inorganic carbon in deep-water kelps from the Strait of Gibraltar.

PubMed

García-Sánchez, María Jesús; Delgado-Huertas, Antonio; Fernández, José Antonio; Flores-Moya, Antonio

2016-03-01

Mechanisms of inorganic carbon assimilation were investigated in the four deep-water kelps inhabiting sea bottoms at the Strait of Gibraltar; these species are distributed at different depths (Saccorhiza polysiches at shallower waters, followed by Laminaria ochroleuca, then Phyllariopsis brevipes and, at the deepest bottoms, Phyllariopsis purpurascens). To elucidate the capacity to use HCO3(-) as a source of inorganic carbon for photosynthesis in the kelps, different experimental approaches were used. Specifically, we measured the irradiance-saturated gross photosynthetic rate versus pH at a constant dissolved inorganic carbon (DIC) concentration of 2 mM, the irradiance-saturated apparent photosynthesis (APS) rate versus DIC, the total and the extracellular carbonic anhydrase (CAext), the observed and the theoretical photosynthetic rates supported by the spontaneous dehydration of HCO3(-) to CO2, and the δ(13)C signature in tissues of the algae. While S. polyschides and L. ochroleuca showed photosynthetic activity at pH 9.5 (around 1.0 µmol O2 m(-2) s(-1)), the activity was close to zero in both species of Phyllariopsis. The APS versus DIC was almost saturated for the DIC values of natural seawater (2 mM) in S. polyschides and L. ochroleuca, but the relationship was linear in P. brevipes and P. purpurascens. The four species showed total and CAext activities but the inhibition of the CAext originated the observed photosynthetic rates at pH 8.0 to be similar to the theoretical rates that could be supported by the spontaneous dehydration of HCO3(-). The isotopic (13)C signatures ranged from -17.40 ± 1.81 to -21.11 ± 1.73 ‰ in the four species. Additionally, the δ(13)C signature was also measured in the deep-water Laminaria rodriguezii growing at 60-80 m, showing even a more negative value of -26.49 ± 1.25 ‰. All these results suggest that the four kelps can use HCO3(-) as external carbon source for photosynthesis mainly by the action of external CAext, but

Review of hydrogen storage in inorganic fullerene-like nanotubes

NASA Astrophysics Data System (ADS)

Chen, J.; Wu, F.

Following the discovery of carbon nanotubes, inorganic fullerene-like nanotubes such as WS2-MoS2, NbS2, TiS2, and BN were reported. Inorganic (non-carbon) nanotubes constitute an important class of nanomaterials with interesting properties and potential applications. As known, efficient hydrogen storage is one key problem in the development of a hydrogen energy system. Hydrogen storage using carbon nanostructures is scientifically interesting and challenging. It thus would be worthwhile to look into hydrogen storage in inorganic nanotubes because the van der Waals gaps between the nanotube layers are potential candidates for hydrogen uptake. Furthermore, the inorganic nanotubes combine two elements, which is different from the pure carbon nanotubes. These may show a novel hydrogen adsorption-desorption mechanism. The present review provides a brief study of hydrogen adsorption on MoS2, TiS2, and BN nanotubes.

Effects of Land Use and Lithology on the Origin and Cycling of Dissolved Inorganic Carbon in the Brazos River, Texas

NASA Astrophysics Data System (ADS)

Zeng, F.; Masiello, C. A.

2009-12-01

Global rivers annually receive significant amounts of both inorganic and organic carbon from land. The fate of this terrestrial carbon depends largely on factors such as climate, lithology, land use and topography. In this study, we focused on dissolved inorganic carbon (DIC). We directly measured the partial pressure of CO2 (pCO2), and stable and radiocarbon isotopes of riverine DIC to understand how land use and lithology control the origin and cycling of DIC in the Brazos River. We observed a significant difference in the sources and fate of DIC between the middle and lower Brazos. In the middle Brazos, a combination of damming and waste water discharge from urban areas appears to have promoted algal growth, resulting in low pCO2 (646 ± 216 μatm) and young DIC (Δ14C = +85 ± 63‰) in the river water. In the lower Brazos, higher pCO2 (1174 ± 418 μatm) and much older riverine DIC (Δ14C = -151 ± 52‰) are due to a combination of the presence of easily erodible carbonate bedrock (marl) and oyster shells used as construction aggregates, and old organic matter lost from soils caused by agricultural activities. Overall, of the terrestrial inorganic carbon the Brazos received, a larger amount is delivered to the ocean while a smaller fraction is returned to the atmosphere through CO2 outgassing, which is different from the observation in the Amazon River.

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

NASA Astrophysics Data System (ADS)

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.

Theoretical prediction of a novel inorganic fullerene-like family of silicon-carbon materials

NASA Astrophysics Data System (ADS)

Wang, Ruoxi; Zhang, Dongju; Liu, Chengbu

2005-08-01

In an effort to search for new inorganic fullerene-like structures, we designed a series of novel silicon-carbon cages, (SiC) n ( n = 6-36), based on the uniformly hybrid Si-C four- and six-membered-rings, and researched their geometrical and electronic structures, as well as their relative stabilities using the density function theory. Among these cages, the structures for n = 12, 16, and 36 were found to been energetically more favorable. The calculated disproportionation energy and binding energy per SiC unit show that the (SiC) 12 cage is the most stable one among these designed structures. The present calculations not only indicate that silicon-carbon fullerenes are promised to be synthesized in future, but also provide a new way for stabilizing silicon cages by uniformly doping carbon atoms into silicon structures.

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

NASA Astrophysics Data System (ADS)

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

2007-12-01

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

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

Treesearch

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...

The southeastern continental shelf of the United States as an atmospheric CO 2 source and an exporter of inorganic carbon to the ocean

NASA Astrophysics Data System (ADS)

Aleck Wang, Zhaohui; Cai, Wei-Jun; Wang, Yongchen; Ji, Hongwei

2005-10-01

The US southeastern continental shelf, also known as the South Atlantic Bight (SAB), is a strong source of CO 2 to the atmosphere, which is in direct contrast to recent reports regarding other major continental shelves. Both spatial (cross-shelf) and seasonal variations of the CO 2 system were pronounced in the SAB. Sea surface pCO 2 in winter was undersaturated relative to the atmosphere, while oversaturation of pCO 2 dominated the entire shelf water in all other seasons. Annually, the SAB releases CO 2 to the atmosphere at an average rate of 30 g C m -2 (2.5 mol C m -2). This system also discharges dissolved inorganic carbon to the open ocean (30 g C m -2 yr -1). Methods of estimating CO 2 flux and DIC flux are critically evaluated and compared. A carbon mass balance model in the SAB is presented based on inorganic carbon fluxes from this study and organic carbon fluxes from literature. The carbon budget is much closer to balance by using this carbon flux approach than by direct measurements of primary production and respiration. It is concluded that the SAB is a net heterotrophic system annually. Intensified heating, elevated input of inorganic carbon from coastal salt marshes, microbial respiration of marsh-exported organic carbon and the lack of annual spring blooms all contribute to maintaining the SAB as a strong CO 2 source to the atmosphere during the warm seasons. In winter, the primary factor that governs the CO 2 sink in the SAB is likely the cooling process. Strong heterotrophy during warm seasons also sustains the SAB to be an exporter of inorganic carbon to the open ocean annually. The SAB shelf functions differently from the East China Sea, the North Atlantic European Shelves, and the Mid-Atlantic Bight as a source or sink of atmospheric CO 2. The SAB is classified as a "marsh-dominated" shelf as compared to other shelves in terms of carbon dynamics. Further work to study carbon dynamics in coastal margins is warranted to interpret their roles in

Nitrogen recovery from wastewater using gas-permeable membranes: Impact of inorganic carbon content and natural organic matter

USDA-ARS?s Scientific Manuscript database

Gas-permeable membranes coupled with low-rate aeration are useful to recover ammonium from livestock effluents. In this study, the role of inorganic carbon (bicarbonate) to enhance the nitrogen (N) recovery process was evaluated using synthetic effluents with various ammonium to bicarbonate molar ra...

High-Temperature Inorganic Self-Healing Inorganic Cement Composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pyatina, Tatiana; Sugama, Toshifumi

The data files below summarize the results from various experiments testing properties of high-temperature self-healing inorganic cement composites. These properties include cement-carbon steel bond strength, Young's modulus recovery, matrix recovery strength, and compressive strength and Yonug's modulus for cement composites modified with Pozzolanic Clay additives.

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

PubMed

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

2016-05-01

In view of the climate changes caused by the continuously rising levels of atmospheric CO2 , advanced technologies associated with CO2 conversion are highly desirable. In recent decades, electrochemical reduction of CO2 has been extensively studied since it can reduce CO2 to value-added chemicals and fuels. Considering the sluggish reaction kinetics of the CO2 molecule, efficient and robust electrocatalysts are required to promote this conversion reaction. Here, recent progress and opportunities in inorganic heterogeneous electrocatalysts for CO2 reduction are discussed, from the viewpoint of both experimental and computational aspects. Based on elemental composition, the inorganic catalysts presented here are classified into four groups: metals, transition-metal oxides, transition-metal chalcogenides, and carbon-based materials. However, despite encouraging accomplishments made in this area, substantial advances in CO2 electrolysis are still needed to meet the criteria for practical applications. Therefore, in the last part, several promising strategies, including surface engineering, chemical modification, nanostructured catalysts, and composite materials, are proposed to facilitate the future development of CO2 electroreduction. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

PubMed

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

2011-06-01

Using ion exchange resin as transfer media, regenerate powdered activated carbon (PAC) adsorbed inorganic ions by cavitation to enhance the transfer; we studied how the regeneration time and the mass ratio of resin and PAC influence the regeneration rate respectively through re-adsorption. The result showed that the effective regeneration of PAC saturated with inorganic ions was above 90% using ion exchange resin as media and transfer carrier, the quantity of PAC did not reduced but activated in the process. Copyright © 2011 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

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

PubMed

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.

Constraints on Early Triassic carbon cycle dynamics from paired organic and inorganic carbon isotope records

NASA Astrophysics Data System (ADS)

Meyer, K. M.; Yu, M.; Lehrmann, D.; van de Schootbrugge, B.; Payne, J. L.

2013-01-01

Large δ13C excursions, anomalous carbonate precipitates, low diversity assemblages of small fossils, and evidence for marine euxinia in uppermost Permian and Lower Triassic strata bear more similarity to Neoproterozoic carbonates than to the remainders of the Permian and Triassic systems. Middle Triassic diversification of marine ecosystems coincided with the waning of anoxia and stabilization of the global carbon cycle, suggesting that environment-ecosystem linkages were important to biological recovery. However, the Earth system behavior responsible for these large δ13C excursions remains poorly constrained. Here we present a continuous Early Triassic δ13Corg record from south China and use it to test the extent to which Early Triassic excursions in δ13Ccarb record changes in the δ13C of marine dissolved inorganic carbon (DIC). Regression analysis demonstrates a significant positive correlation between δ13Corg and δ13Ccarb across multiple sections that span a paleoenvironmental gradient. Such a correlation is incompatible with diagenetic alteration because no likely mechanism will alter both δ13Corg and δ13Ccarb records in parallel and therefore strongly indicates a primary depositional origin. A simple explanation for this correlation is that a substantial portion of the preserved Corg was derived from the contemporaneous DIC pool, implying that the observed excursions reflect variation in the δ13C of the exogenic carbon reservoir (ocean, atmosphere, biomass). These findings support existing evidence that large δ13C excursions are primary and therefore strengthen the case that large-scale changes to the carbon cycle were mechanistically linked to the low diversity and small size of Early Triassic fossils. Associated sedimentary and biogeochemical phenomena further suggest that similar associations in Neoproterozoic and Cambrian strata may reflect the same underlying controls.

Dissolved inorganic and organic carbon yields and fluxes in a permafrost catchment on the Qinghai-Tibet Plateau

NASA Astrophysics Data System (ADS)

Wang, G.; Mao, T.; Zhang, T.; Chen, X.

2015-12-01

Riverine transport of carbon from terrestrial to the aquatic ecosystems is an important component of the global carbon cycle. A warming climate can inevitably accelerate the microbial breakdown of organic carbon and the release of carbon dioxide especially in frozen soils (permafrost) within Arctic and sub-Arctic regions. In addition, high hydraulic conductivity and low sorption capacity of the shallow soil active layer overlying impermeable permafrost together lead to quick DOM transport to streams. In different regions, the response of dissolved carbon to climate warming is different due to the differences in hydrology, climatic conditions, soil types, vegetation conditions, permafrost distribution, catchment size, flow paths. The Qinghai-Tibet Plateau (QTP), of which a significant portion is underlain by permafrost, is considered to be more sensitive to climatic warming than other regions. However, the knowledge of dissolved inorganic and organic carbon transport in the QTP is very limited. We compared the yields and fluxes of DIC/DOC in a small tropical permafrost catchment. Our results showed that: (1) the concentrations ranged from 7.8 to 30.9 mg L-1 for the DIC and ranged from 2.3 to 6.4 mg L-1 for the DOC, the ratio of DIC/DOC concentrations ranged from 2.2 to 5.7 with a mean value of 4.3; (2) the annual export approximately 3.56 t km-2 year-1 for the DIC and 0.73 t km-2 year-1 for the DOC, indicating that the dissolved carbon transported in majority under the inorganic form; (3) the seasonal variations in DIC/DOC export are strongly regulated by variability in runoff, meanwhile the concentration of DIC/DOC showed significant positive correlation with the thawing depth of the active layer and vegetation coverage. Our results provided an understanding about the characteristics of riverine dissolved carbons transport at a permafrost catchment scale on the QTP.

Organic-Inorganic Composites Toward Biomaterial Application.

PubMed

Miyazaki, Toshiki; Sugawara-Narutaki, Ayae; Ohtsuki, Chikara

2015-01-01

Bioactive ceramics are known to exhibit specific biological affinities and are able to show direct integration with surrounding bone when implanted in bony defects. However, their inadequate mechanical properties, such as low fracture toughness and high Young's modulus in comparison to natural bone, limit their clinical application. Bone is a kind of organic-inorganic composite where apatite nanocrystals are precipitated onto collagen fibre networks. Thus, one way to address these problems is to mimic the natural composition of bone by using bioactive ceramics via material designs based on organic-inorganic composites. In this chapter, the current research on the development of the various organic-inorganic composites designed for biomaterial applications has been reviewed. Various compounds such as calcium phosphate, calcium sulphate and calcium carbonate can be used for the inorganic phases to design composites with the desired mechanical and biological properties of bone. Not only classical mechanical mixing but also coating of the inorganic phase in aqueous conditions is available for the fabrication of such composites. Organic modifications using various polymers enable the control of the crystalline structure of the calcium carbonate in the composites. These approaches on the fabrication of organic-inorganic composites provide important options for biomedical materials with novel functions. © 2015 S. Karger AG, Basel.

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

PubMed

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

NASA Astrophysics Data System (ADS)

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

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

NASA Astrophysics Data System (ADS)

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

2016-07-01

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

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

NASA Astrophysics Data System (ADS)

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.

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

NASA Astrophysics Data System (ADS)

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

2016-07-01

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

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

USGS Publications Warehouse

McMahon, Peter B.; Chapelle, Francis H.

1991-01-01

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

Methods for Introducing Inorganic Polymer Concepts throughout the Undergraduate Curriculum

ERIC Educational Resources Information Center

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,…

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

PubMed

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

2016-03-01

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

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

NASA Astrophysics Data System (ADS)

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

2016-07-01

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

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

PubMed Central

Zou, Junyu

2016-01-01

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

Organic and inorganic markers and stable C-, N-isotopic compositions of tropical coastal aerosols from megacity Mumbai: sources of organic aerosols and atmospheric processing

NASA Astrophysics Data System (ADS)

Aggarwal, S. G.; Kawamura, K.; Umarji, G. S.; Tachibana, E.; Patil, R. S.; Gupta, P. K.

2012-08-01

To better understand the sources of PM10 samples from Mumbai, India, aerosol chemical compositions, i.e. total carbon (TC), organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), and inorganic ions were studied together with specific markers such as methanesulfonate (MSA), oxalic acid (C2), azelaic acid (C9), and levoglucosan. The results revealed that biofuel/biomass burning and fossil fuel combustion are the major sources of the Mumbai aerosols. Nitrogen-isotopic (δ15N) composition of aerosol total nitrogen, which ranged from 18.1 to 25.4‰, also suggest that biofuel/biomass burning is the dominant source in both summer and winter seasons. Aerosol mass concentrations of major species increased 3-4 times in winter compared to summer, indicating an enhanced emission from these sources in winter season. Photochemical production tracers, C2 diacid and nssSO42- do not show diurnal changes. Concentrations of C2 diacid and WSOC show a strong correlation (r2 = 0.95). In addition, WSOC to OC (or TC) ratios remain almost constant for day- (0.37 ± 0.06 (0.28 ± 0.04)) and nighttime (0.38 ± 0.07 (0.28 ± 0.06)), suggesting that mixing of fresh secondary organic aerosols is not significant rather the Mumbai aerosols are photochemically well processed. Concentrations of MSA and C9 diacid present a positive correlation (r2 = 0.75), indicating a marine influence on Mumbai aerosols in addition to local/regional influence. Backward air mass trajectory analyses further suggested that the Mumbai aerosols are largely influenced by long-range continental and regional transport. Stable C-isotopic ratios (δ13C) of TC ranged from -27.0 to -25.4‰ with slightly lower average (-26.5 ± 0.3‰) in summer than in winter (-25.9 ± 0.3‰). Positive correlation between WSOC/TC ratios and δ13C values suggested that the increment in δ13C of wintertime TC may be caused by prolonged photochemical processing of organic aerosols in this season. This study suggests

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

NASA Technical Reports Server (NTRS)

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

1998-01-01

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

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

NASA Technical Reports Server (NTRS)

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

2006-01-01

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

[Biogeochemical processes of the major ions and dissolved inorganic carbon in the Guijiang River].

PubMed

Tang, Wen-Kui; Tao, Zhen; Gao, Quan-Zhou; Mao, Hai-Ruo; Jiang, Guang-Hui; Jiao, Shu-Lin; Zheng, Xiong-Bo; Zhang, Qian-Zhu; Ma, Zan-Wen

2014-06-01

Within the drainage basin, information about natural processes and human activities can be recorded in the chemical composition of riverine water. The analysis of the Guijiang River, the first level tributary of the Xijiang River, demonstrated that the chemical composition of water in the Guijiang River was mainly influenced by the chemical weathering of carbonate rocks within the drainage basin, in which CO2 was the main erosion medium, and that the weathering of carbonate rock by H2SO4 had a remarkable impact on the water chemical composition in the Guijiang River. Precipitation, human activities, the weathering of carbonate rocks and silicate rocks accounted for 2.7%, 6.3%, 72.8% and 18.2% of the total dissolved load, respectively. The stable isotopic compositions of dissolved inorganic carbon (delta13C(DIC)) indicated that DIC in the Guijiang River had been assimilated by the phytoplankton in photosynthesis. The primary production of phytoplankton contributed to 22.3%-30.9% of particulate organic carbon (POC) in the Guijiang River, which implies that phytoplankton can transform DIC into POC by photosynthesis, and parts of POC will sink into the bottom of the river in transit, which leads into the formation of burial organic carbon.

Optical and magnetic properties for metal halide-based organic-inorganic layered perovskites

NASA Astrophysics Data System (ADS)

Shikoh, Eiji; Ando, Yasuo; Era, Masanao; Miyazaki, Terunobu

2001-05-01

Layered perovskites (RNH 3) 2CuCl 4, where R was methyl-benzene C 6H 5-CH 2, 1-methyl-naphthalene 1-C 10H 9-CH 2, 1-propyl-naphthalene 1-C 10H 9-O(CH 2) 3 and 1-butyl-naphthalene 1-C 10H 9-O(CH 2) 4, were synthesized. These complexes showed ferromagnetism, with different Curie temperatures, TC, depending on the structure of the molecule. The change of TC by taking into account the overlap of the electronic states between the organic and the inorganic layers were discussed.

Inorganic nanotubes and fullerene-like materials.

PubMed

Tenne, Reshef

2002-12-02

Following the discovery of fullerenes and carbon nanotubes, it was shown that nanoparticles of inorganic layered compounds, like MoS2, are unstable in the planar form and they form closed cage structures with polyhedral or nanotubular shapes. Various issues on the structure, synthesis, and properties of such inorganic fullerene-like structures are reviewed, together with some possible applications.

Switching predominance of organic versus inorganic carbon exports from an intermediate-size subarctic watershed

USGS Publications Warehouse

Dornblaser, Mark M.; Striegl, Robert G.

2015-01-01

Hydrologic exports of dissolved inorganic and organic carbon (DIC, DOC) reflect permafrost conditions in arctic and subarctic river basins. DIC yields in particular, increase with decreased permafrost extent. We investigated the influence of permafrost extent on DIC and DOC yield in a tributary of the Yukon River, where the upper watershed has continuous permafrost and the lower watershed has discontinuous permafrost. Our results indicate that DIC versus DOC predominance switches with interannual changes in water availability and flow routing in intermediate-size watersheds having mixed permafrost coverage. Large water yield and small concentrations from mountainous headwaters and small water yield and high concentrations from lowlands produced similar upstream and downstream carbon yields. However, DOC export exceeded DIC export during high-flow 2011 while DIC predominated during low-flow 2010. The majority of exported carbon derived from near-surface organic sources when landscapes were wet or frozen and from mineralized subsurface sources when infiltration increased.

Influence of water management and natural variability on dissolved inorganic carbon dynamics in a mangrove-dominated estuary.

PubMed

Volta, Chiara; Ho, David T; Friederich, Gernot; Engel, Victor C; Bhat, Mahadev

2018-09-01

High-resolution time series measurements of temperature, salinity, pH and pCO 2 were made during the period October 2014-September 2015 at the midpoint of Shark River, a 15km tidal river that originates in the freshwater Everglades of south Florida (USA) and discharges into the Gulf of Mexico. Dissolved inorganic carbon dynamics in this system vary over time, and during this study could be classified into three distinct regimes corresponding to October 2014-February 2015 (a wet to dry season transition period), March-May 2015 (dry period) and July-September 2015 (wet period). Average net longitudinal dissolved inorganic carbon (DIC) fluxes and air-water CO 2 fluxes from the Shark River estuary were determined for the three periods. Net DIC fluxes to the coast were estimated to vary between 23.2 and 25.4×10 5 mold -1 with an average daily DIC flux of 24.3×10 5 mold -1 during the year of study. CO 2 emissions ranged between 5.5 and 7.8×10 5 mold -1 with an average daily value of 6.4×10 5 mold -1 during the year. The differences in estuarine carbon fluxes during the study period are attributed to differences in the relative importance of hydro-climatological drivers. Results suggest that, during months characterized by reduced rainfall, carbon fluxes are affected by water management via control structures in the upstream Everglades marshes. During months with high rainfall, when culverts are closed and rainfall events are more frequent, carbon fluxes depend more on other forcings, such as rainfall and groundwater discharge. Copyright © 2018 Elsevier B.V. All rights reserved.

Disequilibrium δ18O values in microbial carbonates as a tracer of metabolic production of dissolved inorganic carbon

NASA Astrophysics Data System (ADS)

Thaler, Caroline; Millo, Christian; Ader, Magali; Chaduteau, Carine; Guyot, François; Ménez, Bénédicte

2017-02-01

Carbon and oxygen stable isotope compositions of carbonates are widely used to retrieve paleoenvironmental information. However, bias may exist in such reconstructions as carbonate precipitation is often associated with biological activity. Several skeleton-forming eukaryotes have been shown to precipitate carbonates with significant offsets from isotopic equilibrium with water. Although poorly understood, the origin of these biologically-induced isotopic shifts in biogenic carbonates, commonly referred to as "vital effects", could be related to metabolic effects that may not be restricted to mineralizing eukaryotes. The aim of our study was to determine whether microbially-mediated carbonate precipitation can also produce offsets from equilibrium for oxygen isotopes. We present here δ18O values of calcium carbonates formed by the activity of Sporosarcina pasteurii, a carbonatogenic bacterium whose ureolytic activity produces ammonia (thus increasing pH) and dissolved inorganic carbon (DIC) that precipitates as solid carbonates in the presence of Ca2+. We show that the 1000 lnαCaCO3-H2O values for these bacterially-precipitated carbonates are up to 24.7‰ smaller than those expected for precipitation at isotopic equilibrium. A similar experiment run in the presence of carbonic anhydrase (an enzyme able to accelerate oxygen isotope equilibration between DIC and water) resulted in δ18O values of microbial carbonates in line with values expected at isotopic equilibrium with water. These results demonstrate for the first time that bacteria can induce calcium carbonate precipitation in strong oxygen isotope disequilibrium with water, similarly to what is observed for eukaryotes. This disequilibrium effect can be unambiguously ascribed to oxygen isotope disequilibrium between DIC and water inherited from the oxygen isotope composition of the ureolytically produced CO2, probably combined with a kinetic isotope effect during CO2 hydration/hydroxylation. The fact that

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

NASA Technical Reports Server (NTRS)

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.

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

USGS Publications Warehouse

McMahon, Peter B.; Chapelle, Francis H.

1991-01-01

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

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

PubMed

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

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

PubMed Central

Giguere, Andrew; Chaplen, Frank; Bottomley, Peter J.

2016-01-01

ABSTRACT 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. IMPORTANCE Nitrification, the aerobic oxidation of ammonia to nitrate via nitrite, is an important process in the global nitrogen cycle. This process is generally dependent

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

PubMed

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.

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

NASA Astrophysics Data System (ADS)

Nowak, Martin E.; Schwab, Valérie F.; Lazar, Cassandre S.; Behrendt, Thomas; Kohlhepp, Bernd; Totsche, Kai Uwe; Küsel, Kirsten; Trumbore, Susan E.

2017-08-01

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 demonstrate the large

Effects of Air Contact on Growth, Inorganic Carbon Sources, and Nitrogen Uptake by an Amphibious Freshwater Macrophyte.

PubMed Central

Madsen, T. V.; Breinholt, M.

1995-01-01

Callitriche cophocarpa Sendtner is a heterophyllous amphibious macrophyte that produces apical rosettes of floating leaves. The importance of air contact for inorganic carbon and N uptake and for growth was investigated. Plants were grown with the floating rosette in contact with air of various humidities (10, 50, and >90% relative humidity) and with the submerged parts in N-free water at 350 [mu]M free CO2 and the roots in sediment with low or high NH3-N content. Humidity greatly affected the transpiration rate, whereas growth rate and N content were unaffected and were comparable to values measured for fully submerged shoots. Air contact had, however, a significant impact on growth when the free CO2 concentration in the water was low. Thus, the growth rate of shoots with air contact was about 3 times faster than the rate of fully submerged shoots when grown at air-equilibrium concentration of dissolved free CO2 in the water (16 [mu]M). This difference decreased with increased dissolved free CO2 concentration in the water, and the two shoot types grew at the same rate when the submerged shoots received >350 [mu]M free CO2. The quantitative importance of the floating rosette for total carbon uptake declined also with decreased ratio of floating rosette to total shoot weight. It is concluded that floating rosettes can enhance the inorganic carbon uptake of Callitriche. In contrast, air contact is of minor importance for nutrient transport. PMID:12228350

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

PubMed

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.

Inorganic carbon fluxes on the Mackenzie Shelf of the Beaufort Sea

NASA Astrophysics Data System (ADS)

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

Organic and inorganic markers and stable C-, N-isotopic compositions of tropical coastal aerosols from megacity Mumbai: sources of organic aerosols and atmospheric processing

NASA Astrophysics Data System (ADS)

Aggarwal, S. G.; Kawamura, K.; Umarji, G. S.; Tachibana, E.; Patil, R. S.; Gupta, P. K.

2013-05-01

To better understand the sources of PM10 samples in Mumbai, India, aerosol chemical composition, i.e., total carbon (TC), organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), and inorganic ions were studied together with specific markers such as methanesulfonate (MSA), oxalic acid (C2), azelaic acid (C9), and levoglucosan. The results revealed that biofuel/biomass burning and fossil fuel combustion are the major sources of the Mumbai aerosols. Nitrogen-isotopic (δ15N) composition of aerosol total nitrogen, which ranged from 18.1 to 25.4‰, also suggests that biofuel/biomass burning is a predominate source in both the summer and winter seasons. Aerosol mass concentrations of major species increased 3-4 times in winter compared to summer, indicating enhanced emission from these sources in the winter season. Photochemical production tracers, C2 diacid and nssSO42-, do not show diurnal changes. Concentrations of C2 diacid and WSOC show a strong correlation (r2 = 0.95). In addition, WSOC to OC (or TC) ratios remain almost constant for daytime (0.37 ± 0.06 (0.28 ± 0.04)) and nighttime (0.38 ± 0.07 (0.28 ± 0.06)), suggesting that mixing of fresh secondary organic aerosols is not significant and the Mumbai aerosols are photochemically well processed. Concentrations of MSA and C9 diacid present a positive correlation (r2 = 0.75), indicating a marine influence on Mumbai aerosols in addition to local/regional influence. Backward air mass trajectory analyses further suggested that the Mumbai aerosols are largely influenced by long-range continental and regional transport. Stable C-isotopic ratios (δ13C) of TC ranged from -27.0 to -25.4‰, with slightly lower average (-26.5 ± 0.3‰) in summer than in winter (-25.9 ± 0.3‰). Positive correlation between WSOC/TC ratios and δ13C values suggested that the relative increment in 13C of wintertime TC may be caused by prolonged photochemical processing of organic aerosols in this season. This

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

NASA Astrophysics Data System (ADS)

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

NASA Astrophysics Data System (ADS)

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.

Electron Microscopy of Tungsten Disulphide Inorganic Nanomaterials

DTIC Science & Technology

2009-09-01

cylindrical molecule similar to a carbon nanotube. Inorganic nanotubes have been observed in some mineral deposits. Linus Pauling suggested the...diffraction pattern was due to the carbon coating. Figure 6 SAED taken from the single nanotube shown in figure 5 REFERENCES 1. Pauling , L; "The

Wind-driven Ocean Circulation and the Spatial-temporal Variability of Dissolved Inorganic Carbon in the Gulf of Tehuantepec, North Eastern Tropical Pacific

NASA Astrophysics Data System (ADS)

Chapa, C.; Beier, E.; Durazo, R.; Martin Hernandez-Ayon, J. M.; Alin, S. R.; Lopez-Perez, A.

2016-12-01

The relationship between the surface enrichment of dissolved inorganic carbon (DIC) and wind variability and circulation in the Gulf of Tehuantepec (GT) was examined from satellite images and in situ data from three cruises (June 2010; April and November 2013). Monthly mean wind climatologies (and derived variables), sea surface temperature and sea surface height anomaly fields were analyzed in the GT and part of the NETP. Signal decomposition according to circulation scales (seasonal, inter-annual, mesoscale) was performed using harmonic analysis for the seasonal components, and empirical orthogonal functions for the residuals, applied to satellite sea-level anomaly data. The results show that wind is the main driving force of the variability in the GT. Mesoscale is the variable with the highest percent of local variance (25-75%), due mainly to mesoscale eddies, followed by seasonality (20-55%), and finally the inter-annual signal (10-30%), dominated by ENSO. Mesoscale and seasonality prevailed during the samplings. The changes in circulation led to variations in the concentration of surface DIC ranging between 100 and 300 µmol kg-1 (436 µatm) due to Ekman pumping. The largest enrichment occurred in November 2013 after a strong northerly wind event. However, the predominance of mesoscale events suggests that changes in dissolved inorganic carbon resulting from mesoscale- derived Ekman pumping may become important in the long term and with a larger spatial and temporal coverage. The results suggest that the seasonal cycle of dissolved inorganic carbon may be linked to wind seasonality.

Controls of streamwater dissolved inorganic carbon dynamics in a forested watershed

USGS Publications Warehouse

Finlay, J.C.

2003-01-01

I investigated controls of stream dissolved inorganic carbon (DIC) sources and cycling along a stream size and productivity gradient in a temperate forested watershed in northern California. Dissolved CO2 (CO2 (aq)) dynamics in heavily shaded streams contrasted strongly with those of larger, open canopied sites. In streams with canopy cover > 97%, CO2 (aq) was highest during baseflow periods (up to 540 ??M) and was negatively related to discharge. Effects of algal photosynthesis on CO2 (aq) were minimal and stream CO2 (aq) was primarily controlled by groundwater CO2 (aq) inputs and degassing losses to the atmosphere. In contrast to the small streams. CO2 (aq) in larger, open-canopied streams was often below atmospheric levels at midday during baseflow and was positively related to discharge. Here, stream CO2 (aq) was strongly influenced by the balance between autotrophic and heterotrophic processes. Dynamics of HCO3- were less complex. HCO3- and Ca2+ were positively correlated, negatively related to discharge, and showed no pattern with stream size. Stable carbon isotope ratios of DIC (i.e. ??13C DIC) increased with stream size and discharge, indicating contrasting sources of DIC to streams and rivers. During summer baseflows, ??13C DIC were 13C-depleted in the smallest streams (minimum of -17.7???) due to the influence of CO2 (aq) derived from microbial respiration and HCO3- derived from carbonate weathering. ??13C DIC were higher (up to -6.6???) in the larger streams and rivers due to invasion of atmospheric CO2 enhanced by algal CO2 (aq) uptake. While small streams were influenced by groundwater inputs, patterns in CO2 (aq) and evidence from stable isotopes demonstrate the strong influence of stream metabolism and CO2 exchange with the atmosphere on stream and river carbon cycles.

Photoluminescent carbon dots based on a rare 3D inorganic-organic hybrid cadmium borate crystal.

PubMed

Zhou, Kang; Zhang, Wen-Jin; Luo, Yuan-Zhang; Pan, Chun-Yang

2018-05-17

A 3D inorganic-organic hybridized skeleton cadmium borate [Cden][B5O8(OH)] (1) (en = ethylenediamine) has been solvothermally synthesized. By calcining it, specific shape carbon dots (C-dots) with abundant free radicals were observed. In addition, C-dots in the ethanol phase exhibited variable photoluminescence and showed rare turn on or off effects to Cr3+ ions and CdSe/ZnS quantum dots, but only a turn on effect to Cs+ ions and a turn off effect to CsPbBr3 quantum dots.

Sediment-water fluxes of dissolved inorganic carbon, O2,nutrients, and N2 from the hypoxic region of the Louisianacontinental shelf

EPA Science Inventory

Sediment fluxes of dissolved inorganic carbon (DIC), O2, nutrients, and N2 (denitrification) were measured on the Louisiana Continental Shelf during six cruises from 2005 to 2007. On each cruise, three to seven stations were occupied in regions of the shelf that experience summer...

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

PubMed

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.

Inorganic carbon fixation by chemosynthetic ectosymbionts and nutritional transfers to the hydrothermal vent host-shrimp Rimicaris exoculata

PubMed Central

Ponsard, Julie; Cambon-Bonavita, Marie-Anne; Zbinden, Magali; Lepoint, Gilles; Joassin, André; Corbari, Laure; Shillito, Bruce; Durand, Lucile; Cueff-Gauchard, Valérie; Compère, Philippe

2013-01-01

The shrimp Rimicaris exoculata dominates several hydrothermal vent ecosystems of the Mid-Atlantic Ridge and is thought to be a primary consumer harbouring a chemoautotrophic bacterial community in its gill chamber. The aim of the present study was to test current hypotheses concerning the epibiont's chemoautotrophy, and the mutualistic character of this association. In-vivo experiments were carried out in a pressurised aquarium with isotope-labelled inorganic carbon (NaH13CO3 and NaH14CO3) in the presence of two different electron donors (Na2S2O3 and Fe2+) and with radiolabelled organic compounds (14C-acetate and 3H-lysine) chosen as potential bacterial substrates and/or metabolic by-products in experiments mimicking transfer of small biomolecules from epibionts to host. The bacterial epibionts were found to assimilate inorganic carbon by chemoautotrophy, but many of them (thick filaments of epsilonproteobacteria) appeared versatile and able to switch between electron donors, including organic compounds (heterotrophic acetate and lysine uptake). At least some of them (thin filamentous gammaproteobacteria) also seem capable of internal energy storage that could supply chemosynthetic metabolism for hours under conditions of electron donor deprivation. As direct nutritional transfer from bacteria to host was detected, the association appears as true mutualism. Import of soluble bacterial products occurs by permeation across the gill chamber integument, rather than via the digestive tract. This first demonstration of such capabilities in a decapod crustacean supports the previously discarded hypothesis of transtegumental absorption of dissolved organic matter or carbon as a common nutritional pathway. PMID:22914596

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

PubMed

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.

PubMed

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.

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

NASA Astrophysics Data System (ADS)

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.

Springtime carbon emission episodes at the Gosan background site revealed by total carbon, stable carbon isotopic composition, and thermal characteristics of carbonaceous particles

NASA Astrophysics Data System (ADS)

Jung, J.; Kawamura, K.

2011-11-01

In order to investigate the emission of carbonaceous aerosols at the Gosan background super-site (33.17° N, 126.10° E) in East Asia, total suspended particles (TSP) were collected during spring of 2007 and 2008 and analyzed for particulate organic carbon, elemental carbon, total carbon (TC), total nitrogen (TN), and stable carbon isotopic composition (δ13C) of TC. The stable carbon isotopic composition of TC (δ13CTC) was found to be lowest during pollen emission episodes (range: -26.2‰ to -23.5‰, avg. -25.2 ± 0.9‰), approaching those of the airborne pollen (-28.0‰) collected at the Gosan site. Based on a carbon isotope mass balance equation, we found that ~42% of TC in the TSP samples during the pollen episodes was attributed to airborne pollen from Japanese cedar trees planted around tangerine farms in Jeju Island. A negative correlation between the citric acid-carbon/TC ratios and δ13CTC was obtained during the pollen episodes. These results suggest that citric acid emitted from tangerine fruit may be adsorbed on the airborne pollen and then transported to the Gosan site. Thermal evolution patterns of organic carbon during the pollen episodes were characterized by high OC evolution in the OC2 temperature step (450 °C). Since thermal evolution patterns of organic aerosols are highly influenced by their molecular weight, they can be used as additional information on the formation of secondary organic aerosols and the effect of aging of organic aerosols during the long-range atmospheric transport and sources of organic aerosols.

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

USGS Publications Warehouse

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

2008-01-01

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

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

PubMed

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.

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

PubMed Central

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

Assessment of carbon pools in production forest, Pahang, Malaysia

NASA Astrophysics Data System (ADS)

Azian, M.; Nizam, M. S.; Samsudin, M.; Ismail, P.

2016-11-01

Forest is one of the main sources of carbon stock. Forest plays a key role in sustainable management by providing different aspects of forest ecosystem such as source of timber products, provide of clean water, food sources, etc. A study was conducted to assess carbon pools in selected production forest of Pahang, Malaysia. There are five main types of carbon pools that are recognized available in the forest, i.e. aboveground biomass (AGB), belowground biomass (BGB), deadwood, litter and soil; that these components of carbon pools can accumulate and release carbon into the atmosphere. Five sites with different years of logging period representing status of the forest were selected (i.e. before logging (PU), immediate after logging (P0), after 10 (P10), 20 (P20) and 30 (P30) years of logging). Twenty plots of 0.25 ha (50 m × 50 m) each were established with a total sampling area of 1.0 ha at each site. All trees with ≥10 cm diameter at breast height (dbh) were tagged, identified and measured. Soil at 0-30 cm, litter and dead wood were sampled and collected in every each of sub-plots to determine and assess carbon stocks within sites. The results indicated that AGB carbon had highest portion of carbon compared to soil, BGB, deadwood and litter, which comprised about 63% of the total carbon pools. It was followed by soil and BGB that comprised about 22% and 13%, respectively. Deadwood and litter contributes the same percentage which is about 1%. In terms of status of the forest, AGB contained the highest carbon which is range from 110.49 tC ha-1 to 164.49 tC ha-1 compared with soil (33.72 tC ha-1 to 68.51 tC ha-1), BGB tC ha-1 to 34 tC ha-1), deadwood (1.57 tC ha-1 to 5.55 tC ha-1) and litter (1.42 tC ha-1 to 2.19 tC ha-1). Results from this study will be very helpful as baseline of carbon storage in different status of forest from before harvesting to logged-over forest and the impact of harvesting on the carbon stock in Pahang and Peninsular Malaysia as a whole.

Resolving the Intricacies of Lateral Exports of Inorganic Carbon and Alkalinity from Coastal Salt Marshes

NASA Astrophysics Data System (ADS)

Wang, A. Z.; Chu, S. N.; Kroeger, K. D.; Gonneea, M. E.; Ganju, N. K.

2017-12-01

Dynamic lateral exports of dissolved inorganic carbon (DIC) and total alkalinity (Alk) via tidal exchange from highly productive intertidal marshes are an important piece of puzzle in the coastal carbon cycle, challenging our capability of assessing coastal carbon budgets and projecting future changes under anthropogenic pressure. The effects of these exports on seawater chemistry are profound yet complicated to study. This study presents the latest development of assessing lateral DIC and Alk fluxes from tidal marshes and examining their effects on seawater chemistry and coastal carbon budgets. The study evaluates different approaches to quantify these exports in order to obtain insights on the best and efficient way to capture the dynamics of such exports. A state-of-the-art DIC sensor, Channelized Optical System (CHANOS), was deployed to establish the true DIC fluxes. They are compared to the fluxes derived from empirical modeling and traditional bottle measurements. Salt marshes can acidify and alkalize tidal water by injecting CO2 (DIC) and Alk over a same tidal cycle. However, their generation is decoupled as a result of deferential effects of aerobic and anaerobic respirations. This creates complex scenarios of large swings of seawater chemistry and buffering capacity in tidal water over tidal and seasonal cycles. Marsh exports of DIC and Alk may have complex implications for the future, more acidified ocean. The latest estimates of marsh DIC and Alk exports suggest they are a major term in the marsh carbon budget and can be translated into one of the primary components in the coastal carbon cycle.

Springtime carbon episodes at Gosan background site revealed by total carbon, stable carbon isotopic composition, and thermal characteristics of carbonaceous particles

NASA Astrophysics Data System (ADS)

Jung, J.; Kawamura, K.

2011-05-01

In order to investigate the carbon episodes at Gosan background super-site (33.17° N, 126.10° E) in East Asia during spring of 2007 and 2008, total suspended particles (TSP) were collected and analyzed for particulate organic carbon, elemental carbon, total carbon (TC), total nitrogen (TN), and stable carbon isotopic composition (δ13C) of TC. The carbon episodes at the Gosan site were categorized as long-range transported anthropogenic pollutant (LTP) from Asian continent, Asian dust (AD) accompanying with LTP, and local pollen episodes. The stable carbon isotopic composition of TC (δ13CTC) was found to be lowest during the pollen episodes (range: -26.2 ‰ to -23.5 ‰, avg.: -25.2 ± 0.9 ‰), followed by the LTP episodes (range: -23.5 ‰ to -23.0 ‰, avg.: -23.3 ± 0.3 ‰) and the AD episodes (range: -23.3 to -20.4 %, avg.: -21.8 ± 2.0 ‰). The δ13CTC of the airborne pollens (-28.0 ‰) collected at the Gosan site showed value similar to that of tangerine fruit (-28.1 ‰) produced from Jeju Island. Based on the carbon isotope mass balance equation and the TN and TC regression approach, we found that ∼40-45 % of TC in the TSP samples during the pollen episodes was attributed to airborne pollens from Japanese cedar trees planted around tangerine farms in Jeju Island. The δ13C of citric acid in the airborne pollens (-26.3 ‰) collected at the Gosan site was similar to that in tangerine fruit (-27.4 ‰). The negative correlation between the citric acid-carbon/TC ratios and δ13CTC were obtained during the pollen episodes. These results suggest that citric acid emitted from tangerine fruit may be adsorbed on the airborne pollens and then transported to the Gosan site. Based on the thermal evolution pattern of organic aerosols during the carbon episodes, we found that organic aerosols originated from East China are more volatile on heating and are more likely to form pyrolized organic carbon than the pollen-enriched organic aerosols and organic

Inorganic Nanomaterials as Carriers for Drug Delivery.

PubMed

Chen, Shizhu; Hao, Xiaohong; Liang, Xingjie; Zhang, Qun; Zhang, Cuimiao; Zhou, Guoqiang; Shen, Shigang; Jia, Guang; Zhang, Jinchao

2016-01-01

For safe and effective therapy, drugs must be delivered efficiently and with minimal systemic side effects. Nanostructured drug carriers enable the delivery of small-molecule drugs as well as nucleic acids and proteins. Inorganic nanomaterials are ideal for drug delivery platforms due to their unique physicochemical properties, such as facile preparation, good storage stability and biocompatibility. Many inorganic nanostructure-based drug delivery platforms have been prepared. Although there are still many obstacles to overcome, significant advances have been made in recent years. This review focuses on the status and development of inorganic nanostructures, including silica, quantum dots, gold, carbon-based and magnetic iron oxide-based nanostructures, as carriers for chemical and biological drugs. We specifically highlight the extensive use of these inorganic drug carriers for cancer therapy. Finally, we discuss the most important areas in the field that urgently require further study.

Dissolved inorganic carbon enhanced growth, nutrient uptake, and lipid accumulation in wastewater grown microalgal biofilms.

PubMed

Kesaano, Maureen; Gardner, Robert D; Moll, Karen; Lauchnor, Ellen; Gerlach, Robin; Peyton, Brent M; Sims, Ronald C

2015-03-01

Microalgal biofilms grown to evaluate potential nutrient removal options for wastewaters and feedstock for biofuels production were studied to determine the influence of bicarbonate amendment on their growth, nutrient uptake capacity, and lipid accumulation after nitrogen starvation. No significant differences in growth rates, nutrient removal, or lipid accumulation were observed in the algal biofilms with or without bicarbonate amendment. The biofilms possibly did not experience carbon-limited conditions because of the large reservoir of dissolved inorganic carbon in the medium. However, an increase in photosynthetic rates was observed in algal biofilms amended with bicarbonate. The influence of bicarbonate on photosynthetic and respiration rates was especially noticeable in biofilms that experienced nitrogen stress. Medium nitrogen depletion was not a suitable stimulant for lipid production in the algal biofilms and as such, focus should be directed toward optimizing growth and biomass productivities to compensate for the low lipid yields and increase nutrient uptake. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

NASA Astrophysics Data System (ADS)

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.

Liquid scintillation counting methodology for 99Tc analysis. A remedy for radiopharmaceutical waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khan, Mumtaz; Um, Wooyong

2015-08-13

This paper presents a new approach for liquid scintillation counting (LSC) analysis of single-radionuclide samples containing appreciable organic or inorganic quench. This work offers better analytical results than existing LSC methods for technetium-99 ( 99gTc) analysis with significant savings in analysis cost and time. The method was developed to quantify 99gTc in environmental liquid and urine samples using LSC. Method efficiency was measured in the presence of 1.9 to 11,900 ppm total dissolved solids. The quench curve was proved to be effective in the case of spiked 99gTc activity calculation for deionized water, tap water, groundwater, seawater, and urine samples.more » Counting efficiency was found to be 91.66% for Ultima Gold LLT (ULG-LLT) and Ultima Gold (ULG). Relative error in spiked 99gTc samples was ±3.98% in ULG and ULG-LLT cocktails. Minimum detectable activity was determined to be 25.3 mBq and 22.7 mBq for ULG-LLT and ULG cocktails, respectively. A pre-concentration factor of 1000 was achieved at 100°C for 100% chemical recovery.« less

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

NASA Astrophysics Data System (ADS)

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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)more » 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

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

NASA Astrophysics Data System (ADS)

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

2007-02-01

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

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

NASA Astrophysics Data System (ADS)

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.

Carbon-Based Regenerable Sorbents for the Combined Carbon Dioxide and Ammonia Removal for the Primary Life Support System (PLSS)

NASA Technical Reports Server (NTRS)

Wojtowicz, Marek A.; Cosgrove, Joseph E.; Serio, Michael A.; Manthina, Venkata; Singh, Prabhakar; Chullen, Cinda

2014-01-01

Results are presented on the development of reversible sorbents for the combined carbon dioxide and trace-contaminant (TC) removal for use in Extravehicular Activities (EVAs). Since ammonia is the most important TC to be captured, data on TC sorption presented in this paper are limited to ammonia, with results relevant to other TCs to be reported at a later time. The currently available life support systems use separate units for carbon dioxide, trace contaminants, and moisture control, and the long-term objective is to replace the above three modules with a single one. Furthermore, the current TC-control technology involves the use of a packed bed of acid-impregnated granular charcoal, which is non-regenerable, and the carbon-based sorbent under development in this project can be regenerated by exposure to vacuum at room temperature. The objective of this study was to demonstrate the feasibility of using carbon sorbents for the reversible, concurrent sorption of carbon dioxide and ammonia. Several carbon sorbents were fabricated and tested, and multiple adsorption/vacuum-regeneration cycles were demonstrated at room temperature, and also a carbon surface conditioning technique that enhances the combined carbon dioxide and ammonia sorption without impairing sorbent regeneration.

Selection and Screening of DNA Aptamers for Inorganic Nanomaterials.

PubMed

Zhou, Yibo; Huang, Zhicheng; Yang, Ronghua; Liu, Juewen

2018-02-21

Searching for DNA sequences that can strongly and selectively bind to inorganic surfaces is a long-standing topic in bionanotechnology, analytical chemistry and biointerface research. This can be achieved either by aptamer selection starting with a very large library of ≈10 14 random DNA sequences, or by careful screening of a much smaller library (usually from a few to a few hundred) with rationally designed sequences. Unlike typical molecular targets, inorganic surfaces often have quite strong DNA adsorption affinities due to polyvalent binding and even chemical interactions. This leads to a very high background binding making aptamer selection difficult. Screening, on the other hand, can be designed to compare relative binding affinities of different DNA sequences and could be more appropriate for inorganic surfaces. The resulting sequences have been used for DNA-directed assembly, sorting of carbon nanotubes, and DNA-controlled growth of inorganic nanomaterials. It was recently discovered that poly-cytosine (C) DNA can strongly bind to a diverse range of nanomaterials including nanocarbons (graphene oxide and carbon nanotubes), various metal oxides and transition-metal dichalcogenides. In this Concept article, we articulate the need for screening and potential artifacts associated with traditional aptamer selection methods for inorganic surfaces. Representative examples of application are discussed, and a few future research opportunities are proposed towards the end of this article. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Organic and inorganic components of aerosols over the central Himalayas: winter and summer variations in stable carbon and nitrogen isotopic composition.

PubMed

Hegde, Prashant; Kawamura, Kimitaka; Joshi, H; Naja, M

2016-04-01

The aerosol samples were collected from a high elevation mountain site, Nainital, in India (1958 m asl) during September 2006 to June 2007 and were analyzed for water-soluble inorganic species, total carbon, nitrogen, and their isotopic composition (δ(13)C and δ(15)N, respectively). The chemical and isotopic composition of aerosols revealed significant anthropogenic influence over this remote free-troposphere site. The amount of total carbon and nitrogen and their isotopic composition suggest a considerable contribution of biomass burning to the aerosols during winter. On the other hand, fossil fuel combustion sources are found to be dominant during summer. The carbon aerosol in winter is characterized by greater isotope ratios (av. -24.0‰), mostly originated from biomass burning of C4 plants. On the contrary, the aerosols in summer showed smaller δ(13)C values (-26.0‰), indicating that they are originated from vascular plants (mostly of C3 plants). The secondary ions (i.e., SO4 (2-), NH4 (+), and NO3 (-)) were abundant due to the atmospheric reactions during long-range transport in both seasons. The water-soluble organic and inorganic compositions revealed that they are aged in winter but comparatively fresh in summer. This study validates that the pollutants generated from far distant sources could reach high altitudes over the Himalayan region under favorable meteorological conditions.

[Transported fluxes of the riverine carbon and seasonal variation in Pearl River basin].

PubMed

Zhang, Lian-Kai; Qin, Xiao-Qun; Yang, Hui; Huang, Qi-Bo; Liu, Peng-Yu

2013-08-01

The riverine carbon flux is a critical component of global carbon cycle. Riverine water samples were collected from eleven hydrometric stations in the main stream of Pearl River and its tributaries during April and July, 2012. The samples were analyzed for the space and seasonal distribution characteristics of the riverine suspended substance and carbon compositions. Carbon fluxes and erosion modulus of Pearl River basin were also estimated in Boluo, Shijiao, Gaoyao, namely Dongjiang, Beijiang, Xijiang, in these two hydrological seasons. The results showed that the total suspended substance (TSS) and organic carbon, including total particulate organic carbon (POC) and dissolved organic carbon (DOC) have higher concentration in the high-water season than that in the normal-water season. Dissolved inorganic carbon (DIC) has an overwhelming concentration compared to other carbon compositions in Pearl River basin. The DIC concentration shows an order of Xijiang, Beijiang and Dongjiang from high to low. The percentage of allogenic POC in Xijiang, Beijiang and Dongjiang are 78%, 72%, 26%, respectively, and C3 plants are the main sources of allogenic POC in those three tributaries. The transported fluxes of TSS, total carbon (TC), POC, particulate inorganic carbon (PIC), DOC, DIC, total particulate carbon (TPC) and total organic carbon (TOC) are 134 x 10(12),12.69 x 10(12), 2.50 x 10(12), 1.01 x 10(12), 1.13 x 10(12), 8.05 x 10(12), 3.51 x 10(12) and 3.65 x 10(12) g x a(-1), respectively, and the erosion modulus of those compositions are 309 x 10(6), 28.98 x 10(6), 5.75 x 10(6), 2.27 x 10(6), 2.56 x 10(6), 18.4 x 10(6), 8.02 x 10(6) and 8.31 x 10(6) g x (km2 x a)(-1), respectively. Compared with average values of global large rivers, the erosion modulus of DOC, POC, and TOC in Pearl River basin are higher than the corresponding values.

Inorganic carbon and oxygen dynamics in a marsh‐dominated estuary

PubMed Central

Di Iorio, Daniela; Cai, Wei‐Jun; Hopkinson, Charles S.

2017-01-01

Abstract We conducted a free‐water mass balance‐based study 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. We measured open water diurnal O2 and dissolved inorganic carbon (DIC) dynamics 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 O2 to 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. PMID:29456267

Growth, characterization and post-processing of inorganic and hybrid organic-inorganic thin films deposited using atomic and molecular layer deposition techniques

NASA Astrophysics Data System (ADS)

Abdulagatov, Aziz Ilmutdinovich

Atomic layer deposition (ALD) and molecular layer deposition (MLD) are advanced thin film coating techniques developed for deposition of inorganic and hybrid organic-inorganic films respectively. Decreasing device dimensions and increasing aspect ratios in semiconductor processing has motivated developments in ALD. The beginning of this thesis will cover study of new ALD chemistry for high dielectric constant Y 2O3. In addition, the feasibility of conducting low temperature ALD of TiN and TiAlN is explored using highly reactive hydrazine as a new nitrogen source. Developments of these ALD processes are important for the electronics industry. As the search for new materials with more advanced properties continues, attention has shifted toward exploring the synthesis of hierarchically nanostructured thin films. Such complex architectures can provide novel functions important to the development of state of the art devices for the electronics industry, catalysis, energy conversion and memory storage as a few examples. Therefore, the main focus of this thesis is on the growth, characterization, and post-processing of ALD and MLD films for fabrication of novel composite (nanostructured) thin films. Novel composite materials are created by annealing amorphous ALD oxide alloys in air and by heat treatment of hybrid organic-inorganic MLD films in inert atmosphere (pyrolysis). The synthesis of porous TiO2 or Al2O3 supported V2O5 for enhanced surface area catalysis was achieved by the annealing of inorganic TiVxOy and AlV xOy ALD films in air. The interplay between phase separation, surface energy difference, crystallization, and melting temperature of individual oxides were studied for their control of film morphology. In other work, a class of novel metal oxide-graphitic carbon composite thin films was produced by pyrolysis of MLD hybrid organic-inorganic films. For example, annealing in argon of titania based hybrid films enabled fabrication of thin films of intimately

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

PubMed

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.

Intertidal salt marshes as an important source of inorganic carbon to the coastal ocean

USGS Publications Warehouse

Wang, Zhaohui Aleck; Kroeger, Kevin D.; Ganju, Neil K.; Gonneea, Meagan; Chu, Sophie N.

2016-01-01

Dynamic tidal export of dissolved inorganic carbon (DIC) to the coastal ocean from highly productive intertidal marshes and its effects on seawater carbonate chemistry are thoroughly evaluated. The study uses a comprehensive approach by combining tidal water sampling of CO2parameters across seasons, continuous in situ measurements of biogeochemically-relevant parameters and water fluxes, with high-resolution modeling in an intertidal salt marsh of the U.S. northeast region. Salt marshes can acidify and alkalize tidal water by injecting CO2 (DIC) and total alkalinity (TA). DIC and TA generation may also be decoupled due to differential effects of marsh aerobic and anaerobic respiration on DIC and TA. As marsh DIC is added to tidal water, the buffering capacity first decreases to a minimum and then increases quickly. Large additions of marsh DIC can result in higher buffering capacity in ebbing tide than incoming tide. Alkalization of tidal water, which mostly occurs in the summer due to anaerobic respiration, can further modify buffering capacity. Marsh exports of DIC and alkalinity may have complex implications for the future, more acidified ocean. Marsh DIC export exhibits high variability over tidal and seasonal cycles, which is modulated by both marsh DIC generation and by water fluxes. The marsh DIC export of 414 g C m−2 yr−1, based on high-resolution measurements and modeling, is more than twice the previous estimates. It is a major term in the marsh carbon budget and translates to one of the largest carbon fluxes along the U.S. East Coast.

Sol-gel coating of inorganic nanostructures with resorcinol-formaldehyde resin.

PubMed

Li, Na; Zhang, Qiao; Liu, Jian; Joo, Jibong; Lee, Austin; Gan, Yang; Yin, Yadong

2013-06-07

A general sol-gel process has been developed to form a coating of resorcinol-formaldehyde (RF) resin on inorganic nanostructures of various compositions and morphologies. The RF shell can be conveniently converted into carbon through high temperature carbonization under an inert atmosphere.

Thermal Expansion Behavior in TcO2. Toward Breaking the Tc-Tc Bond.

PubMed

Reynolds, Emily; Zhang, Zhaoming; Avdeev, Maxim; Thorogood, Gordon J; Poineau, Frederic; Czerwinski, Kenneth R; Kimpton, Justin A; Kennedy, Brendan J

2017-08-07

The structure of TcO 2 between 25 and 1000 °C has been determined in situ using X-ray powder diffraction methods and is found to remain monoclinic in space group P2 1 /c. Thermal expansion in TcO 2 is highly anisotropic, with negative thermal expansion of the b axis observed above 700 °C. This is the result of an anomalous expansion along the a axis that is a consequence of weakening of the Tc-Tc bonds.

TOPICAL REVIEW Recent developments in inorganically filled carbon nanotubes: successes and challenges

NASA Astrophysics Data System (ADS)

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

2010-10-01

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.

Recent advances in inorganic nanoparticle-based drug delivery systems.

PubMed

Murakami, Tatsuya; Tsuchida, Kunihiro

2008-02-01

Drug delivery systems, designed to enhance drug efficacy and reduce their adverse effects, have evolved accompanied by the development of novel materials. Nanotechnology is an emerging scientific area that has created a variety of intriguing inorganic nanoparticles. In this review, we focus on the feasibility of inorganic nanoparticles, including iron oxide nanoparticles, gold nanoparticles, fullerenes and carbon nanohorns, as drug carriers, and summarize recent advances in this field.

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

NASA Astrophysics Data System (ADS)

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

2015-01-01

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 halothermodynamic 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 d-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.

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

NASA Astrophysics Data System (ADS)

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.

Inorganic membranes for carbon capture and power generation

NASA Astrophysics Data System (ADS)

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

Method for producing heat-resistant semi-inorganic compounds

NASA Technical Reports Server (NTRS)

Yajima, S.; Okamura, K.; Shishido, T.; Hasegawa, Y.

1983-01-01

The method for producing a heat resistant, semi-inorganic compound is discussed. Five examples in which various alcohols, phenols, and aromatic carbonic acids are used to test heat resistance and solubility are provided.

Impact of anthropogenic atmospheric nitrogen and sulfur deposition on ocean acidification and the inorganic carbon system.

PubMed

Doney, Scott C; Mahowald, Natalie; Lima, Ivan; Feely, Richard A; Mackenzie, Fred T; Lamarque, Jean-Francois; Rasch, Phil J

2007-09-11

Fossil fuel combustion and agriculture result in atmospheric deposition of 0.8 Tmol/yr reactive sulfur and 2.7 Tmol/yr nitrogen to the coastal and open ocean near major source regions in North America, Europe, and South and East Asia. Atmospheric inputs of dissociation products of strong acids (HNO(3) and H2SO(4)) and bases (NH(3)) alter surface seawater alkalinity, pH, and inorganic carbon storage. We quantify the biogeochemical impacts by using atmosphere and ocean models. The direct acid/base flux to the ocean is predominately acidic (reducing total alkalinity) in the temperate Northern Hemisphere and alkaline in the tropics because of ammonia inputs. However, because most of the excess ammonia is nitrified to nitrate (NO(3)(-)) in the upper ocean, the effective net atmospheric input is acidic almost everywhere. The decrease in surface alkalinity drives a net air-sea efflux of CO(2), reducing surface dissolved inorganic carbon (DIC); the alkalinity and DIC changes mostly offset each other, and the decline in surface pH is small. Additional impacts arise from nitrogen fertilization, leading to elevated primary production and biological DIC drawdown that reverses in some places the sign of the surface pH and air-sea CO(2) flux perturbations. On a global scale, the alterations in surface water chemistry from anthropogenic nitrogen and sulfur deposition are a few percent of the acidification and DIC increases due to the oceanic uptake of anthropogenic CO(2). However, the impacts are more substantial in coastal waters, where the ecosystem responses to ocean acidification could have the most severe implications for mankind.

[Spatial-temporal distributions of dissolved inorganic carbon and its affecting factors in the Yellow River estuary].

PubMed

Guo, Xing-Sen; Lü, Ying-Chun; Sun, Zhi-Gao; Wang, Chuan-Yuan; Zhao, Quan-Sheng

2015-02-01

Estuary is an important area contributing to the global carbon cycle. In order to analyze the spatial-temporal distribution characteristics of the dissolved inorganic carbon (DIC) in the surface water of Yellow River estuary. Samples were collected in spring, summer, fall, winter of 2013, and discussed the correlation between the content of DIC and environmental factors. The results show that, the DIC concentration of the surface water in Yellow River estuary is in a range of 26.34-39.43 mg x L(-1), and the DIC concentration in freshwater side is higher than that in the sea side. In some areas where the salinity is less than 15 per thousand, the DIC concentration appears significant losses-the maximum loss is 20.46%. Seasonal distribution of performance in descending order is spring, fall, winter, summer. Through principal component analysis, it shows that water temperature, suspended solids, salinity and chlorophyll a are the main factors affecting the variation of the DIC concentration in surface water, their contribution rate is as high as 83% , and alkalinity, pH, dissolved organic carbon, dissolved oxygen and other factors can not be ignored. The loss of DIC in the low area is due to the calcium carbonate sedimentation. DIC presents a gradually increasing trend, which is mainly due to the effects of water retention time, temperature, outside input and environmental conditions.

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

NASA Astrophysics Data System (ADS)

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.

Heterotrophic bacterioplankton control on organic and inorganic carbon cycle in stratified and non-stratified lakes of NW Russia

NASA Astrophysics Data System (ADS)

Shirokova, Liudmila; Vorobjeva, Taissia; Zabelina, Svetlana; Moreva, Olga; Klimov, Sergey; Shorina, Natalja; Chupakov, Artem; Pokrovsky, Oleg; Audry, Stephan; Viers, Jerome

2010-05-01

Lakes of boreal zone regulate the fate of dissolved carbon, nutrients and trace metals during their transport from the watershed to the ocean. Study of primary production - mineralization processes in the context of carbon biogeochemical cycle allows determination of the rate and mechanisms of phytoplankton biomass production and its degradation via aquatic heterotrophic bacteria. In particular, comparative study of vertical distribution of Dissolved Organic Carbon (DOC) in stratified and non-stratified lakes allows establishing the link between biological and chemical aspects of the carbon cycle which, in turns, determines an environmental stability and recovering potential of the entire ecosystem. In order to better understand the biogeochemical mechanisms that control dissolved organic and inorganic carbon migration in surface boreal waters, we studied in 2007-2009 two strongly stratified lakes (15-20 m deep) and two shallow lakes (2-4 m deep) in the Arkhangelsk region (NW Russia, White Sea basin). We conducted natural experiments of the lake water incubation for measurements of the intensity of production/mineralization processes and we determined vertical concentration of DOC during four basic hydrological seasons (winter and summer stratification, and spring and autumn lake overturn). Our seasonal studies of production/mineralization processes demonstrated high intensity of organic matter formation during summer period and significant retard of these processes during winter stagnation. During spring period, there is a strong increase of bacterial destruction of the allochtonous organic matter that is being delivered to the lake via terrigenous input. During autumn overturn, there is a decrease of the activity of phytoplankton, and the degradation of dead biomass by active bacterial community. Organic matter destruction processes are the most active in Svyatoe lake, whereas in the Beloe lake, the rate of organic matter production is significantly higher than

Inorganic rechargeable non-aqueous cell

DOEpatents

Bowden, William L.; Dey, Arabinda N.

1985-05-07

A totally inorganic non-aqueous rechargeable cell having an alkali or alkaline earth metal anode such as of lithium, a sulfur dioxide containing electrolyte and a discharging metal halide cathode, such as of CuCl.sub.2, CuBr.sub.2 and the like with said metal halide being substantially totally insoluble in SO.sub.2 and admixed with a conductive carbon material.

Hybrid organic-inorganic rotaxanes and molecular shuttles.

PubMed

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.

PubMed

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.

Inorganic/organic doped carbon aerogels as biosensing materials for the detection of hydrogen peroxide.

PubMed

Dong, Sheying; Li, Nan; Suo, Gaochao; Huang, Tinglin

2013-12-17

In this article, three different inorganic/organic doped carbon aerogel (CA) materials (Ni-CA, Pd-CA, and Ppy-CA) were, respectively, mixed with ionic liquid (IL) to form three stable composite films, which were used as enhanced elements for an integrated sensing platform to increase the surface area and to improve the electronic transmission rate. Subsequently, the effect of the materials performances such as adsorption, specific surface area and conductivity on electrochemistry for myoglobin (Mb) was discussed using N2 adsorption-desorption isotherm measurements, scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). Moreover, they could act as sensors toward the detection of hydrogen peroxide (H2O2) with lower detection limits (1.68 μM, 1.02 μM, and 0.85 μM, for Ni-CA/IL/Mb-CPE, Pd-CA/IL/Mb-CPE, and Ppy-CA/IL/Mb-CPE, respectively) and smaller apparent Michaelis-Menten constants KM. The results indicated that the electroconductibility of the doped CA materials would become dominant, thus playing an important role in facilitating the electron transfer. Meanwhile, the synergetic effect with [BMIm]BF4 IL improved the capability of the composite inorganic/organic doped CA/IL matrix for protein immobilization. This work demonstrates the feasibility and the potential of a series of CA-based hybrid materials as biosensors, and further research and development are required to prepare other functional CAs and make them valuable for more extensive application in biosensing.

Adsorption of Ammonia on Regenerable Carbon Sorbents

NASA Technical Reports Server (NTRS)

Wójtowicz, Marek A.; Cosgrove, Jesph E.; Serio, Michael A..; Wilburn, Monique

2015-01-01

Results are presented on the development of reversible sorbents for the combined carbon dioxide, moisture, and trace-contaminant (TC) removal for use in Extravehicular Activities (EVAs), and more specifically in the Primary Life Support System (PLSS). The currently available life support systems use separate units for carbon dioxide, trace contaminants, and moisture control, and the long-term objective is to replace the above three modules with a single one. Data on sorption and desorption of ammonia, which is a major TC of concern, are presented in this paper. The current TC-control technology involves the use of a packed bed of acid-impregnated granular charcoal, which is non-regenerable, and the carbon-based sorbent under development in this project can be regenerated by exposure to vacuum at room temperature. In this study, several carbon sorbents were fabricated and tested for ammonia sorption. Ammonia-sorption capacity was related to carbon pore structure characteristics, and the temperature of oxidative carbon-surface treatment was optimized for enhanced ammonia-sorption performance.

Inorganic Membranes: Preparation and Application for Water Treatment and Desalination

PubMed Central

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

Photochemical Mineralization of Terrigenous DOC to Dissolved Inorganic Carbon in Ocean

NASA Astrophysics Data System (ADS)

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

2018-02-01

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 photoproduction and the photobleaching of tCDOM. The linear relationship between DIC photoproduction and tCDOM photobleaching was used to estimate the amount of photoproduced DIC from the tCDOM fluxes of the study rivers. Solar radiation was estimated to mineralize 12.5 ± 3.7 Tg C yr-1 (10 rivers)-1 or 18 ± 8% of tDOC flux. The irradiation experiments also approximated typical apparent spectral quantum yields for DIC photoproduction (ϕλ) over the entire lifetime of the tCDOM. Based on ϕλs and the local solar irradiances in river plumes, the annual areal DIC photoproduction rates from tDOC were calculated to range from 52 ± 4 (Lena River) to 157 ± 2 mmol C m-2 yr-1 (Mississippi River). When the amount of photoproduced DIC was divided by the areal rate, 9.6 ± 2.5 × 106 km2 of ocean was required for the photomineralization of tDOC from the study rivers. Extrapolation to the global tDOC flux yields 45 (31-58) Tg of photoproduced DIC per year in the river plumes that cover 34 (25-43) × 106 km2 of the ocean.

Enhanced 99 Tc retention in glass waste form using Tc(IV)-incorporated Fe minerals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Um, Wooyong; Luksic, Steven A.; Wang, Guohui

Technetium (99Tc) immobilization by doping into iron oxide mineral phases may alleviate the problems with Tc volatility during vitrification of nuclear waste. Reduced Tc, Tc(IV), substitutes for Fe(III) in the crystal structure by a process of Tc reduction from Tc(VII) to Tc(IV) followed by co-precipitation of Fe oxide minerals. Two Tc-incorporated Fe minerals (Tc-goethite and Tc-magnetite/maghemite) were prepared and tested for Tc retention in glass melt samples at temperatures between 600 – 1,000 oC. After being cooled, the solid glass specimens prepared at different temperatures were analyzed for Tc oxidation state using Tc K-edge XANES. In most samples, Tc wasmore » partially oxidized from Tc(IV) to Tc(VII) as the melt temperature increased. However, Tc retention in glass melt samples prepared using Tc-incorporated Fe minerals were moderately higher than in glass prepared using KTcO4 because of limited and delayed Tc volatilization.« less

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

USGS Publications Warehouse

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.

Intrinsic activation: the relationship between biomass inorganic content and porosity formation during pyrolysis.

PubMed

Stratford, James P; Hutchings, Tony R; de Leij, Frans A A M

2014-05-01

The utility of pyrolytic carbons is closely related to their porosity and surface area, there is a clear benefit to the development of biomass pyrolysis processes which produce highly porous carbons. The results presented in this work demonstrate that by using biomass precursors with high inorganic content along with specified process conditions, carbons can be consistently produced with specific surface areas between 900 and 1600 m(2)/g. Results from 12 different source materials show that the formation of increased porosity in pyrolytic carbons is strongly associated with the presence of inorganic elements in the precursors including: magnesium, potassium and sulfur. It was found that pyrolysis of macro-algae can produce especially high specific surface area carbons (mean: 1500 m(2)/g), without externally applied activating agents. Using cheap readily available agricultural residues such as oilseed rape straw, pyrolytic carbons can be produced with specific surface areas of around 950 m(2)/g. Copyright © 2014 Elsevier Ltd. All rights reserved.

Carbon speciation in ash, residual waste and contaminated soil by thermal and chemical analyses.

PubMed

Kumpiene, Jurate; Robinson, Ryan; Brännvall, Evelina; Nordmark, Désirée; Bjurström, Henrik; Andreas, Lale; Lagerkvist, Anders; Ecke, Holger

2011-01-01

Carbon in waste can occur as inorganic (IC), organic (OC) and elemental carbon (EC) each having distinct chemical properties and possible environmental effects. In this study, carbon speciation was performed using thermogravimetric analysis (TGA), chemical degradation tests and the standard total organic carbon (TOC) measurement procedures in three types of waste materials (bottom ash, residual waste and contaminated soil). Over 50% of the total carbon (TC) in all studied materials (72% in ash and residual waste, and 59% in soil) was biologically non-reactive or EC as determined by thermogravimetric analyses. The speciation of TOC by chemical degradation also showed a presence of a non-degradable C fraction in all materials (60% of TOC in ash, 30% in residual waste and 13% in soil), though in smaller amounts than those determined by TGA. In principle, chemical degradation method can give an indication of the presence of potentially inert C in various waste materials, while TGA is a more precise technique for C speciation, given that waste-specific method adjustments are made. The standard TOC measurement yields exaggerated estimates of organic carbon and may therefore overestimate the potential environmental impacts (e.g. landfill gas generation) of waste materials in a landfill environment. Copyright © 2010 Elsevier Ltd. All rights reserved.

The relationship between the dissolved inorganic carbon concentration and growth rate in marine phytoplankton.

PubMed Central

Clark, D R; Flynn, K J

2000-01-01

A range of marine phytoplankton was grown in closed systems in order to investigate the kinetics of dissolved inorganic carbon (DIC) use and the influence of the nitrogen source under conditions of constant pH. The kinetics of DIC use could be described by a rectangular hyperbolic curve, yielding estimations of KG(DIC) (the half saturation constant for carbon-specific growth, i.e. C mu) and mu max (the theoretical maximum C mu). All species attained a KG(DIC) within the range of 30-750 microM DIC. For most species, NH4+ use enabled growth with a lower KG(DIC) and/or, for two species, an increase in mu max. At DIC concentrations of > 1.6 mM, C mu was > 90% saturated for all species relative to the rate at the natural seawater DIC concentration of 2.0 mM. The results suggest that neither the rate nor the extent of primary productivity will be significantly limited by the DIC in the quasi-steady-state conditions associated with oligotrophic oceans. The method needs to be applied in the conditions associated with dynamic coastal (eutrophic) systems for clarification of a potential DIC rate limitation where cells may grow to higher densities and under variable pH and nitrogen supply. PMID:10874743

Variation of photoautotrophic fatty acid production from a highly CO2 tolerant alga, Chlorococcum littorale, with inorganic carbon over narrow ranges of pH.

PubMed

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.

Enhanced 99Tc retention in glass waste form using Tc(IV)-incorporated Fe minerals

DOE PAGES

Um, Wooyong; Luksic, Steven A.; Wang, Guohui; ...

2017-09-07

We present that technetium ( 99Tc) immobilization by doping into iron oxide mineral phases may alleviate the problems with Tc volatility during vitrification of nuclear waste. Because reduced Tc, Tc(IV), substitutes for Fe(III) in the crystal structure by a process of Tc reduction from Tc(VII) to Tc(IV) followed by co-precipitation of Fe oxide minerals, two Tc-incorporated Fe minerals (Tc-goethite and Tc-magnetite/maghemite) were prepared and tested for Tc retention in glass melt samples at temperatures between 600 and 1000 °C. After being cooled, the solid glass specimens prepared at different temperatures at 600, 800, and 1000 °C were analyzed for Tcmore » oxidation state using Tc K-edge XANES. In most samples, Tc was partially (<60%) oxidized from Tc(IV) to Tc(VII) as the melt temperature increased up to 600 °C. However, most of Tc(IV) was completely (>95%) oxidized to Tc(VII) at temperature above 800 °C. Tc retention in glass melt samples prepared using Tc-incorporated Fe minerals were slightly higher (~10%) than in glass prepared using KTcO4 because of limited and delayed Tc volatilization.« less

Enhanced 99Tc retention in glass waste form using Tc(IV)-incorporated Fe minerals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Um, Wooyong; Luksic, Steven A.; Wang, Guohui

We present that technetium ( 99Tc) immobilization by doping into iron oxide mineral phases may alleviate the problems with Tc volatility during vitrification of nuclear waste. Because reduced Tc, Tc(IV), substitutes for Fe(III) in the crystal structure by a process of Tc reduction from Tc(VII) to Tc(IV) followed by co-precipitation of Fe oxide minerals, two Tc-incorporated Fe minerals (Tc-goethite and Tc-magnetite/maghemite) were prepared and tested for Tc retention in glass melt samples at temperatures between 600 and 1000 °C. After being cooled, the solid glass specimens prepared at different temperatures at 600, 800, and 1000 °C were analyzed for Tcmore » oxidation state using Tc K-edge XANES. In most samples, Tc was partially (<60%) oxidized from Tc(IV) to Tc(VII) as the melt temperature increased up to 600 °C. However, most of Tc(IV) was completely (>95%) oxidized to Tc(VII) at temperature above 800 °C. Tc retention in glass melt samples prepared using Tc-incorporated Fe minerals were slightly higher (~10%) than in glass prepared using KTcO4 because of limited and delayed Tc volatilization.« less

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.

PubMed

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.

Recombinant plant gamma carbonic anhydrase homotrimers bind inorganic carbon.

PubMed

Martin, Victoria; Villarreal, Fernando; Miras, Isabelle; Navaza, Alda; Haouz, Ahmed; González-Lebrero, Rodolfo M; Kaufman, Sergio B; Zabaleta, Eduardo

2009-11-03

Gamma carbonic anhydrases (gammaCA) are widespread in Prokaryotes. In Eukaryotes, homologous genes were found only in plant genomes. In Arabidopsis and maize, the corresponding gene products are subunits of mitochondrial Complex I. At present, only gammaCA homotrimers of Methanosarcina thermophila (CAM) show reversible carbon dioxide (CO(2)) hydration activity. In the present work, it is shown that recombinant plant gammaCA2 could form homotrimers and bind H(14)CO(3)(-). However, they are unable to catalyse the reversible hydration of CO(2). These results suggest that plant gammaCAs do not act as carbonic anhydrases but with a related activity possibly contributing to recycle CO(2) in the context of photorespiration.

Getters for Tc and I Removal from Liquid Waste

NASA Astrophysics Data System (ADS)

Qafoku, N. P.; Asmussen, M.; Lawter, A.; Neeway, J.; Smith, G.

2015-12-01

A cementitious waste form, Cast Stone, is being evaluated as a possible supplemental waste form for the low activity waste (LAW) at the Hanford Site, which contains significant amounts of radioactive 99Tc and 129I, as part of the tank waste cleanup mission. To improve the retention of Tc and/or I in Cast Stone, materials with a high affinity for Tc and/or I, termed "getters," can be added to decrease the rate of contaminant release and diffusivity, and improve Cast Stone performance. A series of kinetic batch sorption experiments was performed to determine the effectiveness of the getter materials. Several Tc getters [blast furnace slag, Sn (II) apatite, SnCl2, nanoporous Sn phosphate, KMS-2 (a potassium-metal-sulfide), and Sn(II) hydroxyapatite] and I getters [layered Bi hydroxide, natural argentite mineral, synthetic argentite, Ag-impregnated carbon, and Ag-exchanged zeolite] were tested in different solution media, 18.2 MΩ DI H2O and a caustic LAW waste simulant containing 6.5 M Na or 7.8 M Na. The experiments were conducted at room temperature in the presence or absence of air. Results indicated that most Tc getters (with the exception of KMS-2) performed better in the DI H2O solution than in the 6.5 and 7.8 M Na LAW simulant. In addition, Tc sequestration may be affected by the presence of other redox sensitive elements that were present in the LAW simulant, such as Cr. The Tc getter materials have been examined through various solid-state characterization techniques such as XRD, SEM/EDS, XANES and EXAFS which provided evidence for plausible mechanisms of aqueous Tc removal. The results indicated that the Tc precipitates differ depending on the getter material and that Tc(VII) is reduced to Tc(IV) in most of the getters but to a differing extents. For the I getters, Ag-exchanged zeolite and synthetic argentite were the most effective ones. The other I getters showed limited effectiveness for sorbing I under the high ionic strength and caustic

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

NASA Astrophysics Data System (ADS)

Boerner, Audrey R.; Gates, John B.

2015-05-01

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

Monitoring Tc dynamics in a bioreduced sediment: an investigation with gamma camera imaging of (99m)Tc-pertechnetate and (99m)Tc-DTPA.

PubMed

Vandehey, Nicholas T; O'Neil, James P; Slowey, Aaron J; Boutchko, Rostyslav; Druhan, Jennifer L; Moses, William W; Nico, Peter S

2012-11-20

We demonstrate the utility of nuclear medical imaging technologies and a readily available radiotracer, [(99m)Tc]TcO(4)(-), for the noninvasive monitoring of Fe(II) production in acetate-stimulated sediments from Old Rifle, CO, USA. Microcosms consisting of sediment in artificial groundwater media amended with acetate were probed by repeated injection of radiotracer over three weeks. Gamma camera imaging was used to noninvasively quantify the rate and extent of [(99m)Tc]TcO(4)(-) partitioning from solution to sediment. Aqueous Fe(II) and sediment-associated Fe(II) were also measured and correlated with the observed tracer behavior. For each injection of tracer, curves of (99m)Tc concentration in solution vs time were fitted to an analytic function that accounts for both the observed rate of sedimentation as well as the rate of (99m)Tc association with the sediment. The rate and extent of (99m)Tc association with the biostimulated sediment correlated well with the production of Fe(II), and a mechanism of [(99m)Tc]TcO(4)(-) reduction via reaction with surface-bound Fe(II) to form an immobile Tc(IV) species was inferred. After three weeks of bioreduction, a subset of microcosms was aerated in order to reoxidize the Fe(II) to Fe(III), which also destroyed the affinity of the [(99m)Tc]TcO(4)(-) for the sediments. However, within 3 days postoxidation, the rate of Tc(VII) reduction was faster than immediately before oxidation implying a rapid return to more extensive bioreduction. Furthermore, aeration soon after a tracer injection showed that sediment-bound Tc(IV) is rapidly resolubilized to Tc(VII). In contrast to the [(99m)Tc]TcO(4)(-), a second commercially available tracer, (99m)Tc-DTPA (diethylenetriaminepentaacetic acid), had minimal association with sediment in both controls and biostimulated sediments. These experiments show the promise of [(99m)Tc]TcO(4)(-) and (99m)Tc-DTPA as noninvasive imaging probes for a redox-sensitive radiotracer and a conservative flow

[Effects of long-term fertilization on microbial biomass carbon and nitrogen and on carbon source utilization of microbes in a red soil].

PubMed

Sun, Feng-xia; Zhang, Wei-hua; Xu, Ming-gang; Zhang, Wen-ju; Li, Zhao-qiang; Zhang, Jing-ye

2010-11-01

In order to explore the effects of long-term fertilization on the microbiological characters of red soil, soil samples were collected from a 19-year long-term experimental field in Qiyang of Hunan, with their microbial biomass carbon (MBC) and nitrogen (MBN) and microbial utilization ratio of carbon sources analyzed. The results showed that after 19-year fertilization, the soil MBC and MBN under the application of organic manure and of organic manure plus inorganic fertilizers were 231 and 81 mg x kg(-1) soil, and 148 and 73 mg x kg(-1) soil, respectively, being significantly higher than those under non-fertilization, inorganic fertilization, and inorganic fertilization plus straw incorporation. The ratio of soil MBN to total N under the application of organic manure and of organic manure plus inorganic fertilizers was averagely 6.0%, significantly higher than that under non-fertilization and inorganic fertilization. Biolog-ECO analysis showed that the average well color development (AWCD) value was in the order of applying organic manure plus inorganic fertilizers = applying organic manure > non-fertilization > inorganic fertilization = inorganic fertilization plus straw incorporation. Under the application of organic manure or of organic manure plus inorganic fertilizers, the microbial utilization rate of carbon sources, including carbohydrates, carboxylic acids, amino acids, polymers, phenols, and amines increased; while under inorganic fertilization plus straw incorporation, the utilization rate of polymers was the highest, and that of carbohydrates was the lowest. Our results suggested that long-term application of organic manure could increase the red soil MBC, MBN, and microbial utilization rate of carbon sources, improve soil fertility, and maintain a better crop productivity.

[Effect of organic and inorganic toxic compounds on luminescence of luminous fungi].

PubMed

Vydriakova, G A; Gusev, A A; Medvedeva, S E

2011-01-01

The possibility of the development of the solid phase bioluminescent biotest using aerial mycelium of the luminous fungi was investigated. Effect of organic and inorganic toxic compounds (TC) at concentrations from 10(-6) to 1 mg/ml on luminescence of aerial mycelia of four species of luminous fungi-Armillaria borealis (Culture Collection of the Institute of Forest, Siberian Branch, Russian Academy of Sciences), A. mellea, A. gallica, and Lampteromyces japonicus (Fungi Collection of the Botanical Institute, Russian Academy of Sciences)--has been studied. Culture of A. mellea was shown to be most sensitive to solutions of the model TC. It was demonstrated that the sensitivity of the luminous fungi is comparable with the sensitivity of the bacteria that are used for environmental monitoring. Use of the aerial mycelium of the luminous fungi on the solid support as a test object is a promising approach in biotesting for the development of continuous biosensors for air monitoring.

Inorganic nanoparticles in diagnosis and treatment of breast cancer.

PubMed

Núñez, Cristina; Estévez, Sergio Vázquez; Del Pilar Chantada, María

2018-05-01

Nanoparticles are being actively developed for biomolecular profiling of cancer biomarkers, tumor imaging in vivo, and targeted drug delivery. These nanotechnology-based techniques can be applied widely in the management of different malignant diseases, such as breast cancer. Although the number of different types of nanoparticles is increasing rapidly, most can be classified into two major types: particles that contain organic molecules as a major building material (such as dendrimers, micelles, liposomes and carbon nanotubes, and other polymers); and those that use inorganic elements, usually metals, as a core. In particular, inorganic nanoparticles have received increased attention in the recent past as potential diagnostic and therapeutic systems in the field of oncology. This review primarily discusses progress in applications of inorganic nanoparticles for breast cancer imaging and treatment.

Altered [99mTc]Tc-MDP biodistribution from neutron activation sourced 99Mo.

PubMed

Demeter, Sandor; Szweda, Roman; Patterson, Judy; Grigoryan, Marine

2018-01-01

Given potential worldwide shortages of fission sourced 99 Mo/ 99m Tc medical isotopes there is increasing interest in alternate production strategies. A neutron activated 99 Mo source was utilized in a single center phase III open label study comparing 99m Tc, as 99m Tc Methylene Diphosphonate ([ 99m Tc]Tc-MDP), obtained from solvent generator separation of neutron activation produced 99 Mo, versus nuclear reactor produced 99 Mo (e.g., fission sourced) in oncology patients for which an [ 99m Tc]Tc-MDP bone scan would normally have been indicated. Despite the investigational [ 99m Tc]Tc-MDP passing all standard, and above standard of care, quality assurance tests, which would normally be sufficient to allow human administration, there was altered biodistribution which could lead to erroneous clinical interpretation. The cause of the altered biodistribution remains unknown and requires further research.

Use of carbonates for biological and chemical synthesis

DOEpatents

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.

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

NASA Astrophysics Data System (ADS)

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

2016-06-01

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

Evaluation of organic carbon analyzers for space application. [for water reclamation

NASA Technical Reports Server (NTRS)

1984-01-01

The state-of-the-art technology for organic carbon analysis in space applications is evaluated. An investigation into total organic carbon (TOC) analysis has identified a variety of schemes which include different methods for: (1) separation of inorganic carbon from organic carbon and/or differentiation of inorganic carbon from organic carbon; (2) reaction of organic carbon to form a quantifiable species; and (3) detection and measurement of that species. Each method option is discussed.

Performance of TcI/TcVI/TcII Chagas-Flow ATE-IgG2a for universal and genotype-specific serodiagnosis of Trypanosoma cruzi infection

PubMed Central

Alessio, Glaucia Diniz; de Araújo, Fernanda Fortes; Côrtes, Denise Fonseca; Sales Júnior, Policarpo Ademar; Lima, Daniela Cristina; Gomes, Matheus de Souza; do Amaral, Laurence Rodrigues; Xavier, Marcelo Antônio Pascoal; Teixeira-Carvalho, Andréa; Martins-Filho, Olindo Assis; de Lana, Marta

2017-01-01

Distinct Trypanosoma cruzi genotypes have been considered relevant for patient management and therapeutic response of Chagas disease. However, typing strategies for genotype-specific serodiagnosis of Chagas disease are still unavailable and requires standardization for practical application. In this study, an innovative TcI/TcVI/TcII Chagas Flow ATE-IgG2a technique was developed with applicability for universal and genotype-specific diagnosis of T. cruzi infection. For this purpose, the reactivity of serum samples (percentage of positive fluorescent parasites-PPFP) obtained from mice chronically infected with TcI/Colombiana, TcVI/CL or TcII/Y strain as well as non-infected controls were determined using amastigote-AMA, trypomastigote-TRYPO and epimastigote-EPI in parallel batches of TcI, TcVI and TcII target antigens. Data demonstrated that “α-TcII-TRYPO/1:500, cut-off/PPFP = 20%” presented an excellent performance for universal diagnosis of T. cruzi infection (AUC = 1.0, Se and Sp = 100%). The combined set of attributes “α-TcI-TRYPO/1:4,000, cut-off/PPFP = 50%”, “α-TcII-AMA/1:1,000, cut-off/PPFP = 40%” and “α-TcVI-EPI/1:1,000, cut-off/PPFP = 45%” showed good performance to segregate infections with TcI/Colombiana, TcVI/CL or TcII/Y strain. Overall, hosts infected with TcI/Colombiana and TcII/Y strains displayed opposite patterns of reactivity with “α-TcI TRYPO” and “α-TcII AMA”. Hosts infected with TcVI/CL strain showed a typical interweaved distribution pattern. The method presented a good performance for genotype-specific diagnosis, with global accuracy of 69% when the population/prototype scenario include TcI, TcVI and TcII infections and 94% when comprise only TcI and TcII infections. This study also proposes a receiver operating reactivity panel, providing a feasible tool to classify serum samples from hosts infected with distinct T. cruzi genotypes, supporting the potential of this method for universal and genotype

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

NASA Astrophysics Data System (ADS)

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.

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

PubMed

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.

Patterns and Trends of Primary Production, Inorganic Carbon and Oxygen and Their Ecosystem Impacts in a Regional Biogeochemical Ocean Model for Atlantic Canada

NASA Astrophysics Data System (ADS)

Fennel, K.; Rutherford, K. E.; Kuhn, A. M.; Zhang, W.; Brennan, C. E.; Zhang, R.

2016-12-01

Representing coastal oceans in global biogeochemical models is a challenge, yet the ecosystems in these regions are most vulnerable to the combined stressors of ocean warming, deoxygenation, acidification, eutrophication and fishing. Coastal regions also have large air-sea fluxes of CO2, making them an important but poorly quantified component of the global carbon cycle, and are the most relevant for human activities. Regional model applications that are nested within large-scale or global models are necessary for detailed studies of coastal regions. We present results from such a regional biogeochemical model for the northwestern North Atlantic shelves and adjacent deep ocean of Atlantic Canada. The model is an implementation of the Regional Ocean Modeling System (ROMS) and includes an NPZD-type nitrogen cycle model with explicit representation of dissolved oxygen and inorganic carbon. The region is at the confluence of the Gulf Stream and Labrador Current making it highly dynamic, a challenge for analysis and prediction, and prone to large changes. Historically a rich fishing ground, coastal ecosystems in Atlantic Canada have undergone dramatic changes including the collapse of several economically important fish stocks and the listing of many species as threatened or endangered. Furthermore it is unclear whether the region is a net source or sink of atmospheric CO2 with estimates of the size and direction of the net air-sea CO2 flux remaining controversial. We will discuss simulated patterns of primary production, inorganic carbon fluxes and oxygen trends in the context of circulation features and shelf residence times for the present ocean state and present future projections.

Tetracycline removal from water by adsorption/bioadsorption on activated carbons and sludge-derived adsorbents.

PubMed

Rivera-Utrilla, José; Gómez-Pacheco, Carla V; Sánchez-Polo, Manuel; López-Peñalver, Jesús J; Ocampo-Pérez, Raúl

2013-12-15

The objective of this study was to analyze the behavior of activated carbons with different chemical and textural natures in the adsorption of three tetracyclines (TCs) (tetracycline, oxytetracycline, and chlortetracycline). We also assessed the influence of the solution pH and ionic strength on the adsorption of these compounds and studied their removal by the combined use of microorganisms and activated carbon (bioadsorption). Sludge-derived materials were also used to remove TC from water. The capacity of these materials to adsorb TC was very high and was much greater than that of commercial activated carbon. This elevated adsorption capacity (512.1-672.0 mg/g) is explained by the high tendency of TC to form complex ions with some of the metal ions present in these materials. The medium pH and presence of electrolytes considerably affected TCs adsorption on commercial activated carbon. These results indicate that electrostatic adsorbent-adsorbate interactions play an important role in TC adsorption processes when conducted at pH values that produce TC deprotonation. The presence of bacteria during the TCs adsorption process decreases their adsorption/bioadsorption on the commercial activated carbon, weakening interactions between the adsorbate and the microfilm formed on the carbon surface. The adsorptive capacity was considerably lower in dynamic versus static regime, attributable to problems of TC diffusion into carbon pores and the shorter contact time between adsorbate and adsorbent. Copyright © 2013 Elsevier Ltd. All rights reserved.

Adsorption of Carbon Dioxide, Ammonia, Formaldehyde, and Water Vapor on Regenerable Carbon Sorbents

NASA Technical Reports Server (NTRS)

Wojtowicz, Marek A.; Cosgrove, Joseph E.; Serio, Michael A.; Wilburn, Monique

2015-01-01

Results are presented on the development of reversible sorbents for the combined carbon dioxide, moisture, and trace-contaminant (TC) removal for use in Extravehicular Activities (EVAs), and more specifically in the Primary Life Support System (PLSS). The currently available life support systems use separate units for carbon dioxide, trace contaminants, and moisture control, and the long-term objective is to replace the above three modules with a single one. Furthermore, the current TC-control technology involves the use of a packed bed of acid-impregnated granular charcoal, which is nonregenerable, and the carbon-based sorbent under development in this project can be regenerated by exposure to vacuum at room temperature. In this study, several carbon sorbents were fabricated and tested for simultaneous carbon dioxide, ammonia, formaldehyde, and water sorption. Multiple adsorption/vacuum-regeneration cycles were demonstrated at room temperature, and also the enhancement of formaldehyde sorption by the presence of ammonia in the gas mixture.

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

USGS Publications Warehouse

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.

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

PubMed

Díez-Pascual, Ana M; Naffakh, Mohammed

2013-07-26

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 (T g ). IF-WS₂ contents higher than 0.5 wt % increased T g 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.

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

PubMed Central

Díez-Pascual, Ana M.; Naffakh, Mohammed

2013-01-01

Carbon fiber (CF)-reinforced high-temperature thermoplastics such as poly(phenylene sulphide) (PPS) are widely used in structural composites for aerospace and automotive applications. The porosity of CF-reinforced polymers is a very important topic for practical applications since there is a direct correlation between void content and mechanical properties. In this study, inorganic fullerene-like tungsten disulphide (IF-WS2) lubricant nanoparticles were used to manufacture PPS/IF-WS2/CF 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. PMID:28811429

Fertilization increases paddy soil organic carbon density.

PubMed

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.

Fertilization increases paddy soil organic carbon density*

PubMed Central

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

Carbon storage and sequestration by urban trees in the USA

Treesearch

David J. Nowak; Daniel E. Crane

2002-01-01

Based on field data from 10 USA cities and national urban tree cover data, it is estimated that urban trees in the coterminous USA currently store 700 million tonnes of carbon ($14,300 million value) with a gross carbon sequestration rate of 22.8 million tC/yr ($460 rnillion/year). Carbon storage within cities ranges From 1.2 million tC in New York, NY, to 19,300 tC in...

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

PubMed

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.

PubMed

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.

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

PubMed

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

2015-01-01

Mercury is considered as a toxic heavy metal in aquatic environments due to accumulation in bodies of living organisms. Exposure to mercury may lead to different toxic effects in humans including damages to kidneys and nervous system. Multi-walled carbon nanotubes (MWCNTs) were selected as sorbent to remove mercury from aqueous solution using batch technique. ICP instrument was used to determine the amount of mercury in solution. Moreover, pH, contact time and initial concentration of mercury were studied to determine the influence of these parameters on the adsorption conditions. Results indicate that the adsorption strongly depended on pH and the best pH for adsorption is about 7. The rate of adsorption process initially was rapid but it was gradually reduced with increasing of contact time and reached the equilibrium after 120 min. In addition, more than 85 % of initial concentration of 0.1 mg/l was removed at 0.5 g/l concentration of sorbent and contact time of 120 min. Meanwhile, the adsorption process followed the pseudo second-order model and the adsorption isotherms could be described by both the Freundlich and the Langmuir models. This study showed that MWCNTs can effectively remove inorganic mercury from aqueous solutions as adsorbent.

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

NASA Astrophysics Data System (ADS)

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

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

NASA Astrophysics Data System (ADS)

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.

Submicron magnetite grains and carbon compounds in Martian meteorite ALH84001: inorganic, abiotic formation by shock and thermal metamorphism.

PubMed

Treiman, Allan H

2003-01-01

Purported biogenic features of the ALH84001 Martian meteorite (the carbonate globules, their submicron magnetite grains, and organic matter) have reasonable inorganic origins, and a comprehensive hypothesis is offered here. The carbonate globules were deposited from hydrothermal water, without biological mediation. Thereafter, ALH84001 was affected by an impact shock event, which raised its temperature nearly instantaneously to 500-700K, and induced iron-rich carbonate in the globules to decompose to magnetite and other minerals. The rapidity of the temperature increase caused magnetite grains to nucleate in abundance; hence individual crystals were very small. Nucleation and growth of magnetite crystals were fastest along edges and faces of the precursor carbonate grains, forcing the magnetite grains to be platy or elongated, including the "truncated hexa-octahedra" shape. ALH84001 had formed at some depth within Mars where the lithostatic pressure was significantly above that of Mars' surface. Also, because the rock was at depth, the impact heat dissipated slowly. During this interval, magnetite crystals approached chemical equilibria with surrounding minerals and gas. Their composition, nearly pure Fe(3)O(4), reflects those of equilibria; elements that substitute into magnetite are either absent from iron-rich carbonate (e.g., Ti, Al, Cr), or partitioned into other minerals during magnetite formation (Mg, Mn). Many microstructural imperfections in the magnetite grains would have annealed out as the rock cooled. In this post-shock thermal regime, carbon-bearing gas from the decomposition of iron carbonates reacted with water in the rock (or from its surroundings) to produce organic matter via Fischer-Tropschlike reactions. Formation of such organic compounds like polycyclic aromatic hydrocarbons would have been catalyzed by the magnetite (formation of graphite, the thermochemically stable phase, would be kinetically hindered).

Development of Tc(IV)-Incorporated Fe Minerals to Enhance 99Tc Retention in Glass Waste Form

DOE Office of Scientific and Technical Information (OSTI.GOV)

Um, Wooyong; Luksic, Steven A.; Wang, Guohui

Iron minerals have been considered to be good hosts for Tc immobilization because the Tc(IV) ion substitutes for Fe(III) in the crystal structure of the Fe oxide due to similarities in (1) cation size [Tc(IV) = 78.5 pm ; Fe(III) = 69 or 78.5 pm], (2) metal-oxygen interatomic distance (Tc—O = 0.199 nm, Fe—O = 0.203 nm), (3) number of coordinating oxygen atoms (both 6-fold coordinated), and (4) the redox potential (Eh=ca. +20 mV at pH = 7) for a redox couple between Tc(VII)/Tc(IV) and Fe(III)/Fe(II). Magnetite, maghemite, and trevorite are iron oxide minerals and all belong to spinel mineralmore » group. Laboratory testing shows that Tc can be removed from aqueous waste solutions by a process of Tc reduction from Tc(VII) to Tc(IV) followed by co-precipitation with iron oxide minerals during recrystallization of Fe(OH)2(s) used as an initial solid precursor. X-ray absorption near edge structure (XANES) spectroscopy confirmed that Tc was in the +4 oxidation state in final Tc-Fe minerals. The Tc-incorporated Fe minerals were also tested for Tc retention in glass melts at different temperatures between 600 – 1,000 oC in a furnace. After being cooled in air, the solid glass specimens collected at different temperatures were analyzed for Tc oxidation state using XANES and Tc retention using liquid scintillation counting (LSC). Even though Tc(IV) started to reoxidize at 600 oC, Tc retention in the final glass specimen prepared with Tc-incorporated Fe mineral even at high temperatures was at least two times higher than glass prepared with KTcO4 salt. Higher Tc retention in glass is considered to result from limited and delayed Tc volatilization process due to Fe mineral encapsulation for Tc. Therefore, the results showing the presence of Tc(IV) in the Fe mineral structure indicate strong possibility to enhance Tc retention in borosilicate glass as well as to reduce the remediation costs at the Hanford Site.« less

Geochemistry of dissolved inorganic carbon in a Coastal Plain aquifer. 1. Sulfate from confining beds as an oxidant in microbial CO2 production

USGS Publications Warehouse

Chapelle, F.H.; McMahon, P.B.

1991-01-01

A primary source of dissolved inorganic carbon (DIC) in the Black Creek aquifer of South Carolina is carbon dioxide produced by microbially mediated oxidation of sedimentary organic matter. Groundwater chemistry data indicate, however, that the available mass of inorganic electron acceptors (oxygen, Fe(III), and sulfate) and observed methane production is inadequate to account for observed CO2 production. Although sulfate concentrations are low (approximately 0.05-0.10 mM) in aquifer water throughout the flow system, sulfate concentrations are greater in confining-bed pore water (0.4-20 mM). The distribution of culturable sulfate-reducing bacteria in these sediments suggests that this concentration gradient is maintained by greater sulfate-reducing activity in sands than in clays. Calculations based on Fick's Law indicate that possible rates of sulfate diffusion to aquifer sediments are sufficient to explain observed rates of CO2 production (about 10-5 mmoll-1 year-1), thus eliminating the apparent electron-acceptor deficit. Furthermore, concentrations of dissolved hydrogen in aquifer water are in the range characteristic of sulfate reduction (2-6 nM), which provides independent evidence that sulfate reduction is the predominant terminal electron-accepting process in this system. The observed accumulation of pyrite- and calcite-cemented sandstones at sand-clay interfaces is direct physical evidence that these processes have been continuing over the history of these sediments. ?? 1991.

Inorganic fullerenes and nanotubes: Wealth of materials and morphologies

NASA Astrophysics Data System (ADS)

Bar-Sadan, M.; Kaplan-Ashiri, I.; Tenne, R.

2007-10-01

It is already well established today that numerous materials form closed-cage structures, of which carbon fullerenes and nanotubes are a special case [1]. Inorganic fullerene-like nanoparticles (designated IF) and inorganic nanotubes (INT) have been produced by different routes and experimental techniques, achieving persistent growth of a variety of materials and structural wealth within them. The research in this area has focused on synthesizing new IF and INT materials and understanding their different properties as well as scaling up the synthetic process in order to make it suitable for industrial applications. In this review, the main synthetic procedures to obtain inorganic fullerene-like nanoparticles and nanotubes will be discussed alongside with the different mechanisms that affect the morphology of the final product. The main differences between the morphologies will be presented. Some general considerations relating the properties of the parent compound with the morphology of the product will be mentioned.

Environmental effects of dredging on sediment nutrients, carbon and granulometry in a tropical estuary.

PubMed

Nayar, S; Miller, D J; Hunt, A; Goh, B P L; Chou, L M

2007-04-01

This monitoring study encompassed a period prior to dredging, during dredging and post dredging between July 1999 to June 2000 in Ponggol estuary located along the northeastern coast of Singapore. Mean concentrations of sediment nutrients in mg x Kg(-1) (+/- standard error of means) prior to dredging, during dredging and post dredging were 9.75 +/- 4.24, 8.18 +/- 4.29 and 11.46 +/- 4.74 for ammonium, 0.08 +/- 0.05, 0.06 +/- 0.02 and 0.09 +/- 0.01 for nitrite, 0.04 +/- 0.04, 0.11 +/- 0.17 and 0.25 +/- 0.30 for nitrate, 4.83 +/- 3.48, 0.77 +/- 0.48 and 8.33 +/- 9.73 for phosphate respectively. Pre dredge, dredge and post dredge levels of total carbon (TC) were 18.5 +/- 3.7, 20.2 +/- 3.5 and 34.6 +/- 12.0, of total organic carbon (TOC) were 10.5 +/- 2.9, 19.5 +/- 3.6 and 34.6 +/- 12.0 and of total inorganic carbon (TIC) were 7.9 +/- 1.0, 0.7 +/- 0.4 and non detectable in the sediments, respectively. Both, sediment nutrients and carbon registered lower concentrations with onset of dredging, with the exception of nitrate and TOC. A shift in sedimentary carbon from inorganic carbon to organic carbon was also observed with the onset of the dredging activities when the organically enriched historically contaminated layer was exposed. Sediment granulometry showed that the sediments in the estuary were predominantly silt and clay prior to dredging, which changed to sand with onset of dredging. Silt load in the sediments was highest post-dredge. Sediment nutrients and sediment organic carbon were observed to associate with the finer fractions (silt and clay) of sediments. Finer fractions of sediments get resuspended during a dredging event and are dispersed spatially as the result of tides and water movements. Prior to this study, the potential for nutrient release and sediment granulometry due to dredging have been suggested, but there have been few studies of it, especially in the tropics. The baseline information gathered from this study could be used to work out effective

Hierarchically porous and heteroatom doped carbon derived from tobacco rods for supercapacitors

NASA Astrophysics Data System (ADS)

Zhao, Yong-Qing; Lu, Min; Tao, Peng-Yu; Zhang, Yun-Jie; Gong, Xiao-Ting; Yang, Zhi; Zhang, Guo-Qing; Li, Hu-Lin

2016-03-01

A novel tobacco rods-derived carbon (TC) has been prepared by hydrothermal carbonization and potassium hydroxide activation strategy for supercapacitors application. The physicochemical properties of TC are investigated by X-ray diffraction, Raman spectra, Scanning electron microscopy, Nitrogen adsorption-desorption isotherms, X-ray photoelectron spectroscopy, and four-probe tests. Results show TC derived from different tobacco rods possesses similar properties, such as amorphous state, high specific surface area, hierarchical porous structure, numerous heteroatom groups, and good electrical conductivity. The electrochemical characteristics of TC are examined via cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy measurements. In a three-electrode system, TC exhibits high capacitance with 286.6 F g-1 at 0.5 A g-1, excellent rate performance with 212.1 F g-1 even at 30 A g-1, and outstanding cyclic stability with 96% capacitance retention after 10,000 cycles at 5 A g-1. Furthermore, TC supercapacitor devices can deliver an energy density of 31.3 Wh kg-1 at 0.5 A g-1 and power density of 11.8 kW kg-1 at 15 A g-1. Therefore, this novel concept of tobacco use, namely tobacco rods from cigarette (the harmful) to high-performance carbon for supercapacitors (the beneficial), is an extremely promising strategy for developing high-performance carbon from renewable sources, and supporting the tobacco control.

Differential Assimilation of Inorganic Carbon and Leucine by Prochlorococcus in the Oligotrophic North Pacific Subtropical Gyre

PubMed Central

Björkman, Karin M.; Church, Matthew J.; Doggett, Joseph K.; Karl, David M.

2015-01-01

The light effect on photoheterotrophic processes in Prochlorococcus, and primary and bacterial productivity in the oligotrophic North Pacific Subtropical Gyre was investigated using 14C-bicarbonate and 3H-leucine. Light and dark incubation experiments were conducted in situ throughout the euphotic zone (0–175 m) on nine expeditions to Station ALOHA over a 3-year period. Photosynthetrons were also used to elucidate rate responses in leucine and inorganic carbon assimilation as a function of light intensity. Taxonomic group and cell-specific rates were assessed using flow cytometric sorting. The light:dark assimilation rate ratios of leucine in the top 150 m were ∼7:1 for Prochlorococcus, whereas the light:dark ratios for the non-pigmented bacteria (NPB) were not significant different from 1:1. Prochlorococcus assimilated leucine in the dark at per cell rates similar to the NPB, with a contribution to the total community bacterial production, integrated over the euphotic zone, of approximately 20% in the dark and 60% in the light. Depth-resolved primary productivity and leucine incorporation showed that the ratio of Prochlorococcus leucine:primary production peaked at 100 m then declined steeply below the deep chlorophyll maximum (DCM). The photosynthetron experiments revealed that, for Prochlorococcus at the DCM, the saturating irradiance (Ek) for leucine incorporation was reached at approximately half the light intensity required for light saturation of 14C-bicarbonate assimilation. Additionally, high and low red fluorescing Prochlorococcus populations (HRF and LRF), co-occurring at the DCM, had similar Ek values for their respective substrates, however, maximum assimilation rates, for both leucine and inorganic carbon, were two times greater for HRF cells. Our results show that Prochlorococcus contributes significantly to bacterial production estimates using 3H-leucine, whether or not the incubations are conducted in the dark or light, and this should be

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

PubMed

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.

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

PubMed

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.

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

PubMed

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.

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

NASA Astrophysics Data System (ADS)

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

2010-12-01

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

Redox-responsive theranostic nanoplatforms based on inorganic nanomaterials.

PubMed

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.

Inorganic Carbon and pH in the Gulf of Mexico: Understanding the Deepwater Horizon Region

NASA Astrophysics Data System (ADS)

Young, J.; Yvon-Lewis, S. A.; Bianchi, T. S.; Shields, M. R.; Du, M.

2014-12-01

The breakdown and respiration of oil compounds may contribute to the dissolved inorganic carbon (DIC) pool and thus ocean acidification. The Gulf of Mexico (GOM) has an abundance of natural seeps as well as numerous man-made structures that could provide a source of hydrocarbons to the water column. Samples of seawater were collected on the first GISR (Gulf Integrated Spill Research) cruise (G01) during the first week of July 2012. This cruise covered an area of ~1360 km2 roughly centered on the site of the Deepwater Horizon disaster. Alkalinity profiles for the southeastern most stations indicate lower (~100 μmol/kg) alkalinities at depth when compared to other stations sampled. This results in calculated pHs that are ~0.5 units lower at depth than they are at the other stations. Another group of stations show increased DIC concentrations on the order of 100-150 μmol/kg higher than average at depths at 800 m and 1200 m leading to calculated pHs about 0.2 to 0.4 below average for those depths in all of the stations sampled. These features may or may not be persistent in this region, and the elevated DIC concentrations may be related to organic matter (petroleum or other) oxidation. Samples were collected from this same region 2 years later (June 2014) and the persistence of these features will be discussed in the context of linkages with organic carbon respiration and low pHs.

Hydrologic Transport of Dissolved Inorganic Carbon and Its Control on Chemical Weathering

NASA Astrophysics Data System (ADS)

Calabrese, Salvatore; Parolari, Anthony J.; Porporato, Amilcare

2017-10-01

Chemical weathering is one of the major processes interacting with climate and tectonics to form clays, supply nutrients to soil microorganisms and plants, and sequester atmospheric CO2. Hydrology and dissolution kinetics have been emphasized as factors controlling chemical weathering rates. However, the interaction between hydrology and transport of dissolved inorganic carbon (DIC) in controlling weathering has received less attention. In this paper, we present an analytical model that couples subsurface water and chemical molar balance equations to analyze the roles of hydrology and DIC transport on chemical weathering. The balance equations form a dynamical system that fully determines the dynamics of the weathering zone chemistry as forced by the transport of DIC. The model is formulated specifically for the silicate mineral albite, but it can be extended to other minerals, and is studied as a function of percolation rate and water transit time. Three weathering regimes are elucidated. For very small or large values of transit time, the weathering is limited by reaction kinetics or transport, respectively. For intermediate values, the system is transport controlled and is sensitive to transit time. We apply the model to a series of watersheds for which we estimate transit times and identify the type of weathering regime. The results suggest that hydrologic transport of DIC may be as important as reaction kinetics and dilution in determining chemical weathering rates.

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

PubMed

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.

Agricultural Liming, Irrigation, and Carbon Sequestration

NASA Astrophysics Data System (ADS)

McGill, B. M.; Hamilton, S. K.

2015-12-01

Row crop farmers routinely add inorganic carbon to soils in the form of crushed lime (e.g., calcite or dolomite minerals) and/or inadvertently as bicarbonate alkalinity naturally dissolved in groundwater used for irrigation. In the soil these carbonates can act as either a source or sink of carbon dioxide, depending in large part on nitrogen fertilization and nitrification. The potentially variable fate of lime carbon is not accounted for in the IPCC greenhouse gas inventory model for lime emissions, which assumes that all lime carbon becomes carbon dioxide (irrigation additions are not accounted for). In a corn-soybean-wheat crop rotation at the Kellogg Biological Station Long Term Ecological Research site in southwest Michigan, we are collecting soil porewater from several depths in the vadose zone across a nitrogen fertilizer gradient with and without groundwater irrigation. The soil profile in this region is dominated by carbonate rich glacial outwash that lies 1.5 m below a carbonate-leached zone. We analyze the porewater stoichiometry of calcium, magnesium, and carbonate alkalinity in a conceptual model to reveal the source/sink fate of inorganic carbon. High nitrate porewater concentrations are associated with net carbon dioxide production in the carbonate-leached zone, according to our model. This suggests that the acidity associated with nitrification of the nitrogen fertilizer, which is evident from soil pH measurements, is driving the ultimate fate of lime carbon in the vadose zone. Irrigation is a significant source of both alkalinity and nitrate in drier years, compared to normal rates of liming and fertilization. We will also explore the observed dramatic changes in porewater chemistry and the relationship between irrigation and inorganic carbon fate above and within the native carbonate layer.

Water column profiles of particulate inorganic carbon in the northeast subarctic Pacific Ocean

NASA Astrophysics Data System (ADS)

Sutton, J. N.; Bishop, J. K.; Martinez, E. J.; Weiss, G. A.; Weiss, A.; Derr, A.; Strubhar, W.; Robert, M.; Wood, T.

2013-12-01

High resolution and real-time measurement of particulate inorganic carbon (PIC) content in seawater is necessary to improve our spatial and temporal understanding of marine carbon flux and the possible effects of ocean acidification on the biological pump. On four occasions since August 2012, we have mapped PIC distribution from surface to bottom at 26 stations along the IOS-Canada Line P transect from western Vancouver Island, BC, Canada to Ocean Station PAPA, 50N 145W using a prototype (PIC001) and a near-commercial quality (PIC008) optical birefringence sensor. The sensors are highly modified 6000m-rated WETLabs C-star transmissometers, which use a polarized laser beam and a cross-polarized receiver to measure photons emitted after passing through birefringent solids. At major stations along Line P (P2, P4, P8, P12, P16, P20, P26), one-liter rosette-collected calibration water samples were filtered through 0.45 μm Supor filters using a small-volume direct filtration system. These samples were analysed for acid-leachable particulate elements (with emphasis on Ca, Na, and Mg) by inductively coupled plasma mass spectrometry (ICPMS). ICPMS PIC was calculated as residual Ca after correction for seawater Ca using Na data. Here we report results for late summer (Aug. 2012) and winter (Feb. 2013). As expected, high levels of PIC (> 100 nmol L-1 to > 2000 nmol L-1) were found in surface waters but rapidly declined at depths greater than 200m and increased again in the nepheloid layer (>50 nmol L-1). Striking seasonal differences in PIC content and PIC profile shape were observed particularly at near shore stations P2, P4, P8 and P12. The results from this research, including sensor evolution and calibration performance, will be presented.

Inorganic Polymer Matrix Composite Strength Related to Interface Condition

PubMed Central

Radford, Donald W.; Grabher, Andrew; Bridge, John

2009-01-01

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.

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

PubMed

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) < SJW (-12.48 per thousand) < GB (-10.76 per thousand)) < MJW (-10.30 per thousand) < TJZ (-6.70 per thousand), which demonstrated that δ13C(DIC) would be heavier after rocky desertification and lighter after the rocky desertification are treated and controlled.

PREFACE: 2014 Joint IMEKO TC1-TC7-TC13 Symposium: Measurement Science Behind Safety and Security

NASA Astrophysics Data System (ADS)

Sousa, João A.; Ribeiro, Álvaro S.; Filipe, Eduarda

2015-02-01

The 2014 Joint IMEKO (International Measurement Confederation) TC1-TC7-TC13 Symposium was organized by RELACRE - Portuguese Association of Accredited Laboratories and the Portuguese Society for Metrology, on 3-5 September 2014. The work of this symposium is reported in this volume. The scope of the symposium includes the main topics covered by the above Technical Committees: - TC1 Education and Training in measurement and Instrumentation - TC7 Measurement Science - TC13 Measurements in Biology and Medicine The effort towards excellence of previous events, in this well established series, is maintained. There has been a special focus on measurement science behind safety and security, with the aim of highlighting the interdisciplinary character of measurement science and the importance of metrology in our daily lives. The discussion was introduced by keynote lectures on measurement challenges in biometrics, health monitoring and social sciences, to promote useful interactions with scientists from different disciplines. The Symposium was attended by experts working in these areas from 18 countries, including USA, Japan and China, and provided a useful forum for them to share and exchange their work and ideas. In total over fifty papers are included in the volume, organized according to the presentation sessions. Each paper was independently peer-reviewed by two reviewers from a distinguished international panel. The Symposium was held in Funchal, capital of Madeira Islands, known as the Atlantic Pearl. This wonderful Atlantic archipelago, formed by Madeira and Porto Santo islands, discovered in the 14th century, was chosen to host the 2014 IMEKO TC1-TC7-TC13 Joint Symposium ''Measurement Science behind Safety and Security''. It was the first territory discovered by the Portuguese sailors, when set out to discover a new world, in an epic journey where instrumentation and quality of measurement played a central role in the success of the enterprise, and gave an

Inside out: efflux of carbon dioxide from leaves represents more than leaf metabolism.

PubMed

Stutz, Samantha S; Anderson, Jeremiah; Zulick, Rachael; Hanson, David T

2017-05-17

High concentrations of inorganic carbon in the xylem, produced from root, stem, and branch respiration, travel via the transpiration stream and eventually exit the plant through distant tissues as CO2. Unlike previous studies that focused on the efflux of CO2 from roots and woody tissues, we focus on efflux from leaves and the potential effect on leaf respiration measurements. We labeled transported inorganic carbon, spanning reported xylem concentrations, with 13C and then manipulated transpiration rates in the dark in order to vary the rates of inorganic carbon supply to cut leaves from Brassica napus and Populus deltoides. We used tunable diode laser absorbance spectroscopy to directly measure the rate of gross 13CO2 efflux, derived from inorganic carbon supplied from outside of the leaf, relative to gross 12CO2 efflux generated from leaf cells. These experiemnts showed that 13CO2 efflux was dependent upon the rate of inorganic carbon supply to the leaf and the rate of transpiration. Our data show that the gross leaf efflux of xylem-transported CO2 is likely small in the dark when rates of transpiration are low. However, gross leaf efflux of xylem-transported CO2 could approach half the rate of leaf respiration in the light when transpiration rates and branch inorganic carbon concentrations are high, irrespective of the grossly different petiole morphologies in our experiment. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

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

NASA Astrophysics Data System (ADS)

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.

Geological carbon budget of the Mackenzie River Basin: New insight from the oxidation of rock-derived organic carbon

NASA Astrophysics Data System (ADS)

Horan, K.; Hilton, R. G.; Dellinger, M.; Galy, V.; Gaillardet, J.; Tipper, E.; Selby, D. S.; Ottley, C. J.; Burton, K. W.

2016-12-01

Erosion and weathering transfer carbon between the atmosphere and lithospheric storage, thereby operating to modify Earth's long-term climate. Over millions of years, atmospheric carbon dioxide (CO2) is sequestered during the weathering of silicate minerals by carbonic acid, coupled to carbonate formation, and following the erosion of biospheric organic carbon and its burial in sediments. However, erosion and weathering also act together to release CO2 from the lithosphere. Erosion enhances the rate of oxidative weathering of organic carbon in rocks (petrogenic OC, OCpetro), which is a major CO2 source over geological time. In addition, oxidation of sulfide minerals can produce sulfuric acid that weathers carbonate minerals and results in transient CO2 release. Although these sources and sinks of CO2 are well recognised, limited case studies exist where they have been measured alongside each other. Here we calculate the geological carbon budget during weathering and erosion in the Mackenzie River Basin, Canada. The silicate weathering rate, carbonate weathering rate by sulfuric acid and the sedimentary burial of biospheric organic carbon have been constrained by prior work. Closing the long-term CO2 budget therefore requires us to quantify the OCpetro oxidation rate. To do this, we use dissolved rhenium (Re) concentrations as a proxy for OCpetro weathering using samples collected from 2009 to 2013. We normalise dissolved river Re concentrations to the rock Re concentration ([Re]diss/[Re]rock) to assess the variability in oxidative weathering efficiency. We find [Re]diss/[Re]rock ratios are 2-4 times lower than those calculated for rapidly eroding mountain catchments (e.g. Taiwan), which is consistent with a lower physical erosion rate in the Mackenzie Basin. By making assumptions about the concurrent mobility of Re and CO2 during OCpetro weathering we quantify the OCpetro weathering rate and constrain the associated CO2 flux to be 0.3 tC km-2 yr-1. The transient CO

The contribution of human activities to dissolved inorganic carbon fluxes in a karst underground river system: evidence from major elements and δ¹³C(DIC) in Nandong, Southwest China.

PubMed

Jiang, Yongjun

2013-09-01

Generally, the DIC in karst groundwater is dominantly derived from carbonate dissolution by carbonic acid. However, recently increases in the inorganic carbon flux have been linked to human activities, which nitric and sulfuric acids may contribute to carbonate dissolution. In order to quantify the sources and fluxes of DIC, and evaluate the carbon isotopic evolution of groundwater in Southwest China, the carbonate dissolution by carbonic, sulfuric and nitric acids was evaluated by hydrochemistry and δ¹³C(DIC)of groundwater. The results show that: (1) groundwater collected from residential and agricultural areas, showed higher DIC concentrations and δ¹³C(DIC) than those in groundwater collected from forested and grass land areas; (2) the contributions of carbonate dissolution by carbonic acid to total DIC concentrations in groundwater collected from forested and grass land areas averaged 99%; (3) the contributions of carbonate dissolution by carbonic acid to total DIC concentrations in groundwater, collected from residential and agricultural areas, varied from 40% to 77% with a mean percentage of 62%; (4) while the contributions of carbonate dissolution by sulfuric and nitric acids to total DIC concentrations in groundwater, collected from residential and agricultural areas, varied from 23% to 60% with a mean percentage of 38%; and (5) the δ¹³C(DIC) approaching a value of around -14‰, with a molar ratio between (Ca²⁺+Mg²⁺) and HCO₃⁻ of around 0.5 in groundwater, indicated that the carbonate was dissolved by soil CO₂ from C₃ vegetation under open system conditions. While the δ¹³C(DIC) varying from -5‰ to -11‰, with a variational molar ratio between (Ca²⁺+Mg²⁺) and HCO₃⁻ of 0.5 to 0.8 in groundwater, indicated that carbonate dissolution was controlled by soil CO₂ (from C₃ vegetation), HNO₃ and H₂SO₄. Also, this study indicated that the amount of soil or atmospheric CO₂ consumed during carbonate weathering should

Investigations of inorganic and hybrid inorganic-organic nanostructures

NASA Astrophysics Data System (ADS)

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

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

PubMed

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

2018-03-26

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 (CO 2 ) 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 CO 2 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 CO 2 production by mineralization as well as CO 2 loss by emission, primary production, and carbonate precipitation in lakes, we estimated that the global lateral DIC export can lie within the range of [Formula: see text] to [Formula: see text] 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 CO 2 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 CO 2 sinks and sources, since in-lake carbon transformation is predicted to be altered with climate change.

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

NASA Astrophysics Data System (ADS)

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.

PubMed

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.

Diversity of freshwater Epsilonproteobacteria and dark inorganic carbon fixation in the sulphidic redoxcline of a meromictic karstic lake.

PubMed

Noguerola, Imma; Picazo, Antonio; Llirós, Marc; Camacho, Antonio; Borrego, Carles M

2015-07-01

Sulfidic redoxclines are a suitable niche for the growth and activity of different chemo- and photolithotrophic sulphide-oxidizing microbial groups such as the Epsilonproteobacteria and the green sulfur bacteria (GSB). We have investigated the diversity, abundance and contribution to inorganic carbon uptake of Epsilonproteobacteria in a meromictic basin of Lake Banyoles. CARD-FISH counts revealed that Epsilonproteobacteria were prevalent at the redoxcline in winter (maximum abundance of 2 × 10(6) cells mL(-1), ≈60% of total cells) but they were nearly absent in summer, when GSB bloomed. This seasonal trend was supported by 16S rRNA gene pyrotag datasets, which revealed that the epsilonproteobacterial community was mainly composed of a member of the genus Arcobacter. In situ incubations using NaH(14)CO3 and MAR-CARD-FISH observations showed that this population assimilated CO2 in the dark, likely being mainly responsible for the autotrophic activity at the redoxcline in winter. Clone libraries targeting the aclB gene provided additional evidence of the potential capacity of these epsilonproteobacteria to fix carbon via rTCA cycle. Our data reinforce the key role of Epsilonproteobacteria in linking carbon and sulphur cycles, extend their influence to freshwater karstic lakes and raise questions about the actual contribution of chemolithotrophy at their redoxcline and euxinic water compartments. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Microstructure and Mechanical Properties of C/C Composite/TC17 Joints with Ag-Cu-Ti Brazing Alloy

NASA Astrophysics Data System (ADS)

Cao, Xiujie; Zhu, Ying; Guo, Wei; Peng, Peng; Ma, Kaituo

2017-12-01

Carbon/Carbon composite(C/C) was vacuum brazed to titanium alloy (TC17) using Ag-Cu-Ti brazing alloy. The effects of brazing temperature on the interfacial microstructure and joint properties were investigated by energy dispersive spectrometer (EDS), a scanning electron microscope (SEM), X-ray diffraction (XRD) and Gleeble1500D testing machine. Results show that C/C composite and TC17 were successfully brazed using AgCuTi brazing alloy. Various phases including TiC, Ag(s, s), Cu(s, s), Ti3Cu4, TiCu, and Ti2Cu were formed in the brazed joint. The maximum shear strength of the brazed joints with AgCuTi brazing alloy was 24±1 MPa when brazed at 860°C for 15 min.

Graded porous inorganic materials derived from self-assembled block copolymer templates.

PubMed

Gu, Yibei; Werner, Jörg G; Dorin, Rachel M; Robbins, Spencer W; Wiesner, Ulrich

2015-03-19

Graded porous inorganic materials directed by macromolecular self-assembly are expected to offer unique structural platforms relative to conventional porous inorganic materials. Their preparation to date remains a challenge, however, based on the sparsity of viable synthetic self-assembly pathways to control structural asymmetry. Here we demonstrate the fabrication of graded porous carbon, metal, and metal oxide film structures from self-assembled block copolymer templates by using various backfilling techniques in combination with thermal treatments for template removal and chemical transformations. The asymmetric inorganic structures display mesopores in the film top layers and a gradual pore size increase along the film normal in the macroporous sponge-like support structure. Substructure walls between macropores are themselves mesoporous, constituting a structural hierarchy in addition to the pore gradation. Final graded structures can be tailored by tuning casting conditions of self-assembled templates as well as the backfilling processes. We expect that these graded porous inorganic materials may find use in applications including separation, catalysis, biomedical implants, and energy conversion and storage.

Eddy covariance and biometric measurements show that a savanna ecosystem in Southwest China is a carbon sink

NASA Astrophysics Data System (ADS)

Fei, Xuehai; Jin, Yanqiang; Zhang, Yiping; Sha, Liqing; Liu, Yuntong; Song, Qinghai; Zhou, Wenjun; Liang, Naishen; Yu, Guirui; Zhang, Leiming; Zhou, Ruiwu; Li, Jing; Zhang, Shubin; Li, Peiguang

2017-02-01

Savanna ecosystems play a crucial role in the global carbon cycle. However, there is a gap in our understanding of carbon fluxes in the savanna ecosystems of Southeast Asia. In this study, the eddy covariance technique (EC) and the biometric-based method (BM) were used to determine carbon exchange in a savanna ecosystem in Southwest China. The BM-based net ecosystem production (NEP) was 0.96 tC ha-1 yr-1. The EC-based estimates of the average annual gross primary productivity (GPP), ecosystem respiration (Reco), and net ecosystem carbon exchange (NEE) were 6.84, 5.54, and -1.30 tC ha-1 yr-1, respectively, from May 2013 to December 2015, indicating that this savanna ecosystem acted as an appreciable carbon sink. The ecosystem was more efficient during the wet season than the dry season, so that it represented a small carbon sink of 0.16 tC ha-1 yr-1 in the dry season and a considerable carbon sink of 1.14 tC ha-1 yr-1 in the wet season. However, it is noteworthy that the carbon sink capacity may decline in the future under rising temperatures and decreasing rainfall. Consequently, further studies should assess how environmental factors and climate change will influence carbon-water fluxes.

Influence of inoculum type, inorganic salt and nitrogen to carbon ratio on sclerotium formation and carotenoid production in surface culture of Penicillium sp. PT95.

PubMed

Han, Jian-Rong; Xu, Jun; Zhou, Xiao-Mei

2002-01-01

This study examined the respective effect of inoculum type, inorganic salt and nitrogen to carbon ratio on sclerotium formation and carotenoid production in surface culture of Penicillium sp. PT95. Neither the spore inoculum nor the mycelial pellet inoculum could result in the formation of sclerotium on a modified Czapek agar medium after incubation of 28 days, whereas the inoculum in the form of sclerotium caused the formation of numerous orange, sand-shaped sclerotia after incubation of 14 days. Among four inorganic salts tested, K(2)HPO(4) was more essential to the sclerotium formation and carotenoid production of strain PT95 as compared to KCl, MgSO(4) or FeSO(4). It was also shown that the combination of K(2)HPO(4), KCl and MgSO(4) could produce the best positive cooperation and give the highest sclerotia biomass (782 mg/plate) and carotenoid content in sclerotium (420 microg/g of dry sclerotia) as well as pigment yield (328 microg/plate). The medium containing 0.24 approximately 0.48 g/l sodium nitrate-nitrogen was effective to both the sclerotium formation and carotenoid production of strain PT95 when available maltose-carbon concentrations were at 5.26 approximately 21.05 g/l. The optimal N:C ratio was found to be 1:25.

Factors affecting the behavior of unburned carbon upon steam activation

NASA Astrophysics Data System (ADS)

Lu, Zhe

The main objective of this study is to investigate the factors that could affect the behavior of unburned carbon samples upon steam activation. Through this work, the relationships among the factors that could influence the carbon-steam reaction with the surface area of the produced activated carbon were explored. Statistical analysis was used to relate the chemical and physical properties of the unburned carbon to the surface area of the activated carbon. Six unburned carbons were selected as feedstocks for activated carbon, and marked as UCA through UCF. The unburned carbons were activated using steam at 850°C for 90 minutes, and the surface areas of their activated counterparts were measured using N2 adsorption isotherms at 77K. The activated carbons produced from different unburned carbon precursors presented different surface areas at similar carbon burn-off levels. Moreover, in different carbon burn-off regions, the sequences for surface area of activated carbons from different unburned carbon samples were different. The factors that may affect the carbon-steam gasification reactions, including the concentration of carbon active sites, the crystallite size of the carbon, the intrinsic porous structure of carbon, and the inorganic impurities, were investigated. All unburned carbons investigated in this study were similar in that they showed the very broad (002) and (10 ) carbon peaks, which are characteristic of highly disordered carbonaceous materials. In this study, the unburned carbon samples contained about 17--48% of inorganic impurities. Compared to coals, the unburned carbon samples contain a larger amount of inorganic impurities as a result of the burn-off, or at lease part, of the carbon during the combustion process. These inorganic particles were divided into two groups in terms of the way they are associated with carbon particles: free single particles, and particles combined with carbon particles. As indicated from the present work, unburned

Use of Tc-99m-galactosyl-neoglycoalbumin (Tc-NGA) to determine hepatic blood flow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stadalnik, R.C.; Vera, D.R.; Woodle, E.S.

1984-01-01

Tc-NGA is a new liver radiopharmaceutical which binds to a hepatocyte-specific membrane receptor. Three characteristics of Tc-NGA can be exploited in the measurement of hepatic blood flow (HBF): 1) ability to alter the affinity of Tc-NGA for its receptor by changing the galactose: albumin ratio; 2) ability to achieve a high specific activity with Tc-99m labeling; and 3) ability to administer a high molar dose of Tc-NGA without physiologic side effects. In addition, kinetic modeling of Tc-NGA dynamic data can provide estimates of hepatic receptor concentration. In experimental studies in young pigs, HBF was determined using two techniques: 1) kineticmore » modeling of dynamic data using moderate affinity, low specific activity Tc-NGA (Group A, n=12); and 2) clearance (CL) technique using high affinity, high specific activity Tc-NGA (Group B, n=4). In both groups, HBF was determined simultaneously by continuous infusion of indocyanine green (CI-ICG) with hepatic vein sampling. Regression analysis of HBF measurements obtained with the Tc-NGA kinetic modeling technique and the CI-ICG technique (Group A) revealed good correlation between the two techniques (r=0.802, p=0.02). Similarly, HBF determination by the clearance technique (Group B) provided highly accurate measurements when compared to the CI-ICG technique. Hepatic blood flow measurements by the clearance technique (CL-NGA) fell within one standard deviation of the error associated with each CI-ICG HBF measurement (all CI-ICG standard deviations were less than 10%).« less

Spatial variability of total carbon and soil organic carbon in agricultural soils in Baranja region, Croatia

NASA Astrophysics Data System (ADS)

Bogunović, Igor; Trevisani, Sebastiano; Pereira, Paulo; Šeput, Miranda

2017-04-01

Climate change is expected to have an important influence on the crop production in agricultural regions. Soil carbon represents an important soil property that contributes to mitigate the negative influence of climate change on intensive cropped areas. Based on 5063 soil samples sampled from soil top layer (0-30 cm) we studied the spatial distribution of total carbon (TC) and soil organic carbon (SOC) content in various soil types (Anthrosols, Cambisols, Chernozems, Fluvisols, Gleysols, Luvisols) in Baranja region, Croatia. TC concentrations ranged from 2.10 to 66.15 mg/kg (with a mean of 16.31 mg/kg). SOC concentrations ranged from 1.86 to 58.00 mg/kg (with a mean of 13.35 mg/kg). TC and SOC showed moderate heterogeneity with coefficient of variation (CV) of 51.3% and 33.8%, respectively. Average concentrations of soil TC vary in function of soil types in the following decreasing order: Anthrosols (20.9 mg/kg) > Gleysols (19.3 mg/kg) > Fluvisols (15.6 mg/kg) > Chernozems (14.2 mg/kg) > Luvisols (12.6 mg/kg) > Cambisols (11.1 mg/kg), while SOC concentrations follow next order: Gleysols (15.4 mg/kg) > Fluvisols (13.2 mg/kg) = Anthrosols (13.2 mg/kg) > Chernozems (12.6 mg/kg) > Luvisols (11.4 mg/kg) > Cambisols (10.5 mg/kg). Performed geostatistical analysis of TC and SOC; both the experimental variograms as well as the interpolated maps reveal quite different spatial patterns of the two studied soil properties. The analysis of the spatial variability and of the spatial patterns of the produced maps show that SOC is likely influenced by antrophic processes. Spatial variability of SOC indicates soil health deterioration on an important significant portion of the studied area; this suggests the need for future adoption of environmentally friendly soil management in the Baranja region. Regional maps of TC and SOC provide quantitative information for regional planning and environmental monitoring and protection purposes.

Investigating the Formation Mechanisms and Inorganic Precursors of Formate and Acetate in Lost City Hydrothermal Fluids

NASA Astrophysics Data System (ADS)

Lang, S. Q.; Bernasconi, S. M.; Früh-Green, G.

2010-12-01

Fluids from the Lost City Hydrothermal Field are rich in hydrogen and methane, with high pHs (9 - 11), as a result of serpentinization reactions at moderate temperatures of approximately 120-200°C. It has been predicted that organic carbon compounds would form abiologically under these chemical and thermal conditions from inorganic precursors, in the form of hydrocarbons and organic acids. Previous work has demonstrated the presence of high concentrations of both formate and acetate in the Lost City fluids [Lang et al., 2010, GCA]. Formate is the second most prevalent carbon species in the fluids and may provide local microbial communities with a necessary carbon source in the face of low dissolved inorganic carbon concentrations. The goals of this study are to constrain the formation mechanisms of these organic acids (abiotic vs. biotic) and to identify their inorganic precursors. Formate and acetate were isolated from multiple fluid samples by preparative high-performance liquid chromatography for isotopic analysis. The δ13C of formate is similar to that of Lost City methane, and consistent with an abiological origin. The isotopic signature of acetate is significantly different from these values, and may be indicative of a biological source. Radiocarbon measurements of the isolated formate are in progress and should allow us to determine if the precursor carbon is derived from a mantle or deep-seawater source. Alkaline hydrothermal systems have been proposed as potential sites to the origin of life and formate has been proposed as a critical intermediate towards the kinds of reduced carbon species found in biochemistry. Evidence of an abiological formation mechanism of formate at Lost City may significantly further our understanding of prebiotic chemistry.

Soil Carbon Cycling - More than Changes in Soil Organic Carbon Stocks

NASA Astrophysics Data System (ADS)

Lorenz, K.

2015-12-01

Discussions about soil carbon (C) sequestration generally focus on changes in soil organic carbon (SOC) stocks. Global SOC mass in the top 1 m was estimated at about 1325 Pg C, and at about 3000 Pg C when deeper soil layers were included. However, both inorganically and organically bound carbon forms are found in soil but estimates on global soil inorganic carbon (SIC) mass are even more uncertain than those for SOC. Globally, about 947 Pg SIC may be stored in the top 1 m, and especially in arid and semi-arid regions SIC stocks can be many times great than SOC stocks. Both SIC and SOC stocks are vulnerable to management practices, and stocks may be enhanced, for example, by optimizing net primary production (NPP) by fertilization and irrigation (especially optimizing belowground NPP for enhancing SOC stocks), adding organic matter (including black C for enhancing SOC stocks), and reducing soil disturbance. Thus, studies on soil C stocks, fluxes, and vulnerability must look at both SIC and SOC stocks in soil profiles to address large scale soil C cycling.

Expression of an endoglucanase from Tribolium castaneum (TcEG1) in Saccharomyces cerevisiae.

PubMed

Shirley, Derek; Oppert, Cris; Reynolds, Todd B; Miracle, Bethany; Oppert, Brenda; Klingeman, William E; Jurat-Fuentes, Juan Luis

2014-10-01

Insects are a largely unexploited resource in prospecting for novel cellulolytic enzymes to improve the production of ethanol fuel from lignocellulosic biomass. The cost of lignocellulosic ethanol production is expected to decrease by the combination of cellulose degradation (saccharification) and fermentation of the resulting glucose to ethanol in a single process, catalyzed by the yeast Saccharomyces cerevisiae transformed to express efficient cellulases. While S. cerevisiae is an established heterologous expression system, there are no available data on the functional expression of insect cellulolytic enzymes for this species. To address this knowledge gap, S. cerevisiae was transformed to express the full-length cDNA encoding an endoglucanase from the red flour beetle, Tribolium castaneum (TcEG1), and evaluated the activity of the transgenic product (rTcEG1). Expression of the TcEG1 cDNA in S. cerevisiae was under control of the strong glyceraldehyde-3 phosphate dehydrogenase promoter. Cultured transformed yeast secreted rTcEG1 protein as a functional β-1,4-endoglucanase, which allowed transformants to survive on selective media containing cellulose as the only available carbon source. Evaluation of substrate specificity for secreted rTcEG1 demonstrated endoglucanase activity, although some activity was also detected against complex cellulose substrates. Potentially relevant to uses in biofuel production rTcEG1 activity increased with pH conditions, with the highest activity detected at pH 12. Our results demonstrate the potential for functional production of an insect cellulase in S. cerevisiae and confirm the stability of rTcEG1 activity in strong alkaline environments. © 2013 Institute of Zoology, Chinese Academy of Sciences.

Using isotopes of dissolved inorganic carbon species and water to separate sources of recharge in a cave spring, northwestern Arkansas, USA Blowing Spring Cave

USGS Publications Warehouse

Knierim, Katherine J.; Pollock, Erik; Hays, Phillip D.

2013-01-01

Blowing Spring Cave in northwestern Arkansas is representative of cave systems in the karst of the Ozark Plateaus, and stable isotopes of water (δ18O and δ2H) and inorganic carbon (δ13C) were used to quantify soil-water, bedrock-matrix water, and precipitation contributions to cave-spring flow during storm events to understand controls on cave water quality. Water samples from recharge-zone soils and the cave were collected from March to May 2012 to implement a multicomponent hydrograph separation approach using δ18O and δ2H of water and dissolved inorganic carbon (δ13C–DIC). During baseflow, median δ2H and δ18O compositions were –41.6‰ and –6.2‰ for soil water and were –37.2‰ and –5.9‰ for cave water, respectively. Median DIC concentrations for soil and cave waters were 1.8 mg/L and 25.0 mg/L, respectively, and median δ13C–DIC compositions were –19.9‰ and –14.3‰, respectively. During a March storm event, 12.2 cm of precipitation fell over 82 h and discharge increased from 0.01 to 0.59 m3/s. The isotopic composition of precipitation varied throughout the storm event because of rainout, a change of 50‰ and 10‰ for δ2H and δ18O was observed, respectively. Although, at the spring, δ2H and δ18O only changed by approximately 3‰ and 1‰, respectively. The isotopic compositions of precipitation and pre-event (i.e., soil and bedrock matrix) water were isotopically similar and the two-component hydrograph separation was inaccurate, either overestimating (>100%) or underestimating (<0%) the precipitation contribution to the spring. During the storm event, spring DIC and δ13C–DIC decreased to a minimum of 8.6 mg/L and –16.2‰, respectively. If the contribution from precipitation was assumed to be zero, soil water was found to contribute between 23 to 72% of the total volume of discharge. Although the assumption of negligible contributions from precipitation is unrealistic, especially in karst systems where rapid flow

Recent advances in magnetic resonance microscopy to the physical structure characterization of carbonaceous and inorganic materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gregory, D.M.; Gerald, R.E.; Cody, G.D.

1997-04-01

Magnetic resonance microscopy (MRM) techniques have been employed to study the molecular architectures and properties of structural polymers, fossil fuels, microporous carbons and inorganic catalysts.

Continuous air agglomeration method for high carbon fly ash beneficiation

DOEpatents

Gray, McMahon L.; Champagne, Kenneth J.; Finseth, Dennis H.

2000-01-01

The carbon and mineral components of fly ash are effectively separated by a continuous air agglomeration method, resulting in a substantially carboree mineral stream and a highly concentrated carbon product. The method involves mixing the fly ash comprised of carbon and inorganic mineral matter with a liquid hydrocarbon to form a slurry, contacting the slurry with an aqueous solution, dispersing the hydrocarbon slurry into small droplets within the aqueous solution by mechanical mixing and/or aeration, concentrating the inorganic mineral matter in the aqueous solution, agglomerating the carbon and hydrocarbon in the form of droplets, collecting the droplets, separating the hydrocarbon from the concentrated carbon product, and recycling the hydrocarbon.

Distribution of inorganic species in two Antarctic cryptoendolithic microbial communities

NASA Technical Reports Server (NTRS)

Johnston, C. G.; Vestal, J. R.; Friedmann, E. I. (Principal Investigator)

1989-01-01

Chemical differences were noted between two Antarctic cryptoendolithic (hidden within rock) microenvironments colonized by different microbial communities. Microenvironments dominated by cyanobacteria (BPC) had a higher pH (pH 7-8) than those dominated by lichen (LTL) (pH 4.5-5.5). In order to understand the interactions between the microbiota and the inorganic environment, the inorganic environment was characterized. Water-soluble, carbonate-bound, metal-oxide, organically bound, and residual inorganic species were sequentially extracted from rock samples by chemical means. Each fraction was then quantified using inductively coupled plasma atomic emission spectrometry. BPC contained much more water-soluble and carbonate-bound Ca and Mg than LTL. Metal-oxide species of Al, Fe, and Mn were more abundant in LTL than BPC. Metal oxides appeared to be mobilized (in the order Mn > Fe > Al) from the LTL lichen zone but remained immobile in BPC sandstone. The distribution of K and P bound to metal oxide reflected the distribution of iron oxide in LTL, an indication of the importance of iron in controlling the availability of nutrients in this ecosystem. Metal oxides in turn were likely controlled or influenced by organic matter associated with the lichen community. Despite overall depletion of Fe, Al, and K in the lichen zone, SEM X-ray analysis showed that they were enriched in fungal hyphae. Water-soluble P was present despite the presence of metal oxides, which sequester phosphate. This has biological relevance since P is an essential nutrient.

Identification of novel mammalian hosts and Brazilian biome geographic distribution of Trypanosoma cruzi TcIII and TcIV.

PubMed

Barros, Juliana Helena S; Xavier, Samanta Cristina C; Bilac, Daniele; Lima, Valdirene Santos; Dario, Maria Augusta; Jansen, Ana Maria

2017-08-01

Trypanosoma cruzi is a parasitic protozoan responsible for Chagas disease. Seven different Discrete Typing Units (DTUs) of T. cruzi are currently identified in nature: TcI-TcVI, and TcBat whose distribution patterns in nature, hosts/reservoirs and eco-epidemiological importance are still little known. Here, we present novel data on the geographic distribution and diversity of mammalian hosts and vectors of T. cruzi DTUs TcIII and TcIV. In this study, we analyzed 61 T. cruzi isolates obtained from 18 species of mammals (five orders) and two Hemiptera genera. Samples were collected from five Brazilian biomes (Pantanal, Caatinga, Cerrado, Atlantic Rainforest, and Amazon) previously characterized as Z3 or mixed infection (TcI-Z3) by mini-exon gene PCR. To identify TcIII and TcIV genotypes, we applied restriction fragment length polymorphism analysis to the PCR-amplified histone 3 gene. DTUs TcIII and TcIV were identified in single and mixed infections from wide dispersion throughout five Brazilian biomes studied, with TcIV being the most common. Pantanal was the biome that displayed the largest number of samples characterized as TcIII and TcIV in single and mixed infections, followed by Atlantic Rainforest and Amazon. Species from the Didelphimorphia order displayed the highest frequency of infection and were found in all five biomes. We report, for the first time, the infection of a species of the Artiodactyla order by DTU TcIII. In addition, we describe new host species: five mammals (marsupials and rodents) and two genera of Hemiptera. Our data indicate that DTUs TcIII and TcIV are more widespread and infect a larger number of mammalian species than previously thought. In addition, they are transmitted in restricted foci and cycles, but in different microhabitats and areas with distinct ecological profiles. Finally, we show that DTUs TcIII and TcIV do not present any specific association with biomes or host species. Copyright © 2017. Published by Elsevier B.V.

[Effects of carbon components of fine particulate matter (PM2.5) on atherogenic index of plasma].

PubMed

Fan, Jiao; Qin, Xiaolei; Xue, Xiaodan; Han, Bin; Bai, Zhipeng; Tang, Naijun; Zhang, Liwen

2014-01-01

To evaluate associations between carbon constituents of fine particulate matter (PM2.5) and atherogenic index of plasma (AIP). We collected subjects from two communities by a system sampling, and 112 people aged over 60 years old without cardiovascular disease were recruited. The levels of cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) of objects, and personal exposure to PM2.5 were measured on December, 2011. Total carbon (TC), organic carbon (OC) and elemental carbon (EC) of PM2.5 were detected and AIP was calculated according to its definition. The value of AIP among the 112 subjects was 0.05 ± 0.26. Personal exposure concentration of PM2.5 and its carbon components (TC,OC and EC) were (164.75 ± 110.67), (53.86 ± 29.65), (44.93 ± 26.37) and (9.49 ± 5.75) µg/m(3), respectively. The Pearson analysis showed the linear relationship between TC,OC,EC and AIP, all significant positive correlations. The correlation coefficients were TC (r = 0.307, P < 0.05),OC (r = 0.287, P < 0.05) and EC (r = 0.252, P < 0.05), respectively. The multiple logistic regression analysis showed that when the AIP risk categories were selected as dependent variable and low risk group as reference group, the regression coefficient of TC,OC and EC was separately 1.03 (95%CI:1.01-1.05), 1.03 (95%CI:1.01-1.05), 1.12 (95%CI:1.02-1.22) in the high risk group; while there was no statistical significance of the regression coefficient and OR in the middle risk group. There was stable associations between the carbon constituents (TC,OC and EC) of fine Particulate Matter (PM2.5) and AIP. The findings suggested that carbon components of PM2.5 should be considered as risk factors of atherogenic.

Inorganic nitrogen transformations in the treatment of landfill leachate with a high ammonium load: A case study.

PubMed

Parkes, Stephen D; Jolley, Dianne F; Wilson, Stephen R

2007-01-01

The inorganic nitrogen transformations occurring at a municipal waste leachate treatment facility were investigated. The treatment facility consisted of a collection well and an artificial wetland between two aeration ponds. The first aeration pond showed a decrease in ammonium (from 3480 (+/- 120) to 630(+/- 90) mg x L(-1)), a reduction in inorganic nitrogen load (3480 to 1680 mg N x L(-1)), and an accumulation of nitrite (< 1.3 mg-N x L(-1) in the collection well, to 1030 mg-N x L(-1)). Incomplete ammonium oxidation was presumably the result of the low concentration of carbonate alkalinity (approximately 2 mg x L(-1)), which may cause a limitation in the ammonium oxidation rate of nitrifiers. Low carbonate alkalinity levels may have been the result of stripping of CO(2) from the first aeration pond at the high aeration rates and low pH. Various chemodenitrification mechanisms are discussed as the reason for the reduction in the inorganic nitrogen load, including; the reduction of nitrite by iron (II) (producing various forms of gaseous nitrogen); and reactions involving nitrous acid. It is suggested that the accumulation of nitrite may be the result of inhibition of nitrite oxidizers by nitrous acid and low temperatures. Relative to the first aeration pond, the speciation and concentration of inorganic nitrogen was stable in the wetlands and 2nd aeration pond. The limited denitrification in the wetlands most probably occurred due to low concentrations of organic carbon, and short retention times.

In situ sensor technology for simultaneous spectrophotometric measurements of seawater total dissolved inorganic carbon and pH.

PubMed

Wang, Zhaohui Aleck; Sonnichsen, Frederick N; Bradley, Albert M; Hoering, Katherine A; Lanagan, Thomas M; Chu, Sophie N; Hammar, Terence R; Camilli, Richard

2015-04-07

A new, in situ sensing system, Channelized Optical System (CHANOS), was recently developed to make high-resolution, simultaneous measurements of total dissolved inorganic carbon (DIC) and pH in seawater. Measurements made by this single, compact sensor can fully characterize the marine carbonate system. The system has a modular design to accommodate two independent, but similar measurement channels for DIC and pH. Both are based on spectrophotometric detection of hydrogen ion concentrations. The pH channel uses a flow-through, sample-indicator mixing design to achieve near instantaneous measurements. The DIC channel adapts a recently developed spectrophotometric method to achieve flow-through CO2 equilibration between an acidified sample and an indicator solution with a response time of only ∼ 90 s. During laboratory and in situ testing, CHANOS achieved a precision of ±0.0010 and ± 2.5 μmol kg(-1) for pH and DIC, respectively. In situ comparison tests indicated that the accuracies of the pH and DIC channels over a three-week time-series deployment were ± 0.0024 and ± 4.1 μmol kg(-1), respectively. This study demonstrates that CHANOS can make in situ, climatology-quality measurements by measuring two desirable CO2 parameters, and is capable of resolving the CO2 system in dynamic marine environments.

In-house cyclotron production of high-purity Tc-99m and Tc-99m radiopharmaceuticals.

PubMed

Martini, Petra; Boschi, Alessandra; Cicoria, Gianfranco; Zagni, Federico; Corazza, Andrea; Uccelli, Licia; Pasquali, Micòl; Pupillo, Gaia; Marengo, Mario; Loriggiola, Massimo; Skliarova, Hanna; Mou, Liliana; Cisternino, Sara; Carturan, Sara; Melendez-Alafort, Laura; Uzunov, Nikolay M; Bello, Michele; Alvarez, Carlos Rossi; Esposito, Juan; Duatti, Adriano

2018-05-30

In the last years, the technology for producing the important medical radionuclide technetium-99m by cyclotrons has become sufficiently mature to justify its introduction as an alternative source of the starting precursor [ 99m Tc][TcO 4 ] - ubiquitously employed for the production of 99m Tc-radiopharmaceuticals in hospitals. These technologies make use almost exclusively of the nuclear reaction 100 Mo(p,2n) 99m Tc that allows direct production of Tc-99m. In this study, it is conjectured that this alternative production route will not replace the current supply chain based on the distribution of 99 Mo/ 99m Tc generators, but could become a convenient emergency source of Tc-99m only for in-house hospitals equipped with a conventional, low-energy, medical cyclotron. On this ground, an outline of the essential steps that should be implemented for setting up a hospital radiopharmacy aimed at the occasional production of Tc-99m by a small cyclotron is discussed. These include (1) target production, (2) irradiation conditions, (3) separation/purification procedures, (4) terminal sterilization, (5) quality control, and (6) Mo-100 recovery. To address these issues, a comprehensive technology for cyclotron-production of Tc-99m, developed at the Legnaro National Laboratories of the Italian National Institute of Nuclear Physics (LNL-INFN), will be used as a reference example. Copyright © 2018 Elsevier Ltd. All rights reserved.

Cropland Field Monitoring: MMV Page 1 Montana Cropland Enrolled Farm Fields Carbon Sequestration Field Sampling, Measurement, Monitoring, and Verification: Application of Visible-Near Infrared Diffuse Reflectance Spectroscopy (VNIR) and Laser-induced Breakdown Spectroscopy (LIBS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee Spangler; Ross Bricklemyer; David Brown

2012-03-15

situ nor lab-based spectroscopy yielded even semi-quantitative SOC predictions. There was little SOC variability to explain across the eight fields, and on-the-go VisNIR was not able to capture the subtle SOC variability in these Montana soils. With more variation in soil clay content compared to SOC, both lab and on-the-go VisNIR showed better explanatory power. There are several potential explanations for poor on-the-go predictive accuracy: soil heterogeneity, field moisture, consistent sample presentation, and a difference between the spatial support of on-the-go measurements and soil samples collected for laboratory analyses. Though the current configuration of a commercially available on-the-go VisNIR system allows for rapid field scanning, on-the-go soil processing (i.e. drying, crushing, and sieving) could improve soil carbon predictions. Laser-induced breakdown spectroscopy (LIBS) is an emerging elemental analysis technology with the potential to provide rapid, accurate and precise analysis of soil constituents, such as carbon, in situ across landscapes. The research team evaluated the accuracy of LIBS for measuring soil profile carbon in field-moist, intact soil cores simulating conditions that might be encountered by a probe-mounted LIBS instrument measuring soil profile carbon in situ. Over the course of three experiments, more than120 intact soil cores from eight north central Montana wheat fields and the Washington State University (WSU) Cook Agronomy Farm near Pullman, WA were interrogated with LIBS for rapid total carbon (TC), inorganic carbon (IC), and SOC determination. Partial least squares regression models were derived and independently validated at field- and regional scales. Researchers obtained the best LIBS validation predictions for IC followed by TC and SOC. Laser-induced breakdown spectroscopy is fundamentally an elemental analysis technique, yet LIBS PLS2 models appeared to discriminate IC from TC. Regression coefficients from initial models

Toward organometallic (99m)Tc imaging agents: synthesis of water-stable (99)Tc-NHC complexes.

PubMed

Benz, Michael; Spingler, Bernhard; Alberto, Roger; Braband, Henrik

2013-11-20

(99)Tc(V)O2-NHC complexes containing monodentate and bidentate N-heterocyclic carbenes (NHCs) have been prepared by the reactions of [TcO(glyc)2](-) (glyc = ethyleneglycolato) with 1,3-dimethylimidazoline-2-ylidene (L1), 1,1'-methylene-3,3'-dimethyl-4,4'-diimidazoline-2,2'-diylidene (L2), and 1,1'-methylene-3,3'-diethyl-4,4'-diimidazoline-2,2'-diylidene (L3) in THF. The resulting complexes were fully characterized and their stabilities investigated. While complexes with monodentate NHCs only are hydrolytically unstable, complexes containing bidentate NHCs are water-stable over a broad pH range. The high water stability allows interconversion of the {(99)Tc(V)O2}(+) core into {(99)Tc(V)OCl}(2+) with HCl as the H(+) and Cl(-) source. An alternative procedure to obtain (99)Tc(V)O2-NHC complexes is the in situ deprotonation of imidazolium salts, enabling the preparation of (99)Tc(V)O2-NHC compounds without free NHCs, thus increasing the scope of NHC ligands drastically. The remarkable stability and pH-controllable reactivity of the new complexes underlines the potential of NHCs as stabilizing ligands for (99)Tc complexes and paves the way for the first (99m)Tc-NHC complexes in the future.

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

NASA Astrophysics Data System (ADS)

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.

Estimating Particulate Inorganic Carbon Concentrations of the Global Ocean From Ocean Color Measurements Using a Reflectance Difference Approach

NASA Astrophysics Data System (ADS)

Mitchell, C.; Hu, C.; Bowler, B.; Drapeau, D.; Balch, W. M.

2017-11-01

A new algorithm for estimating particulate inorganic carbon (PIC) concentrations from ocean color measurements is presented. PIC plays an important role in the global carbon cycle through the oceanic carbonate pump, therefore accurate estimations of PIC concentrations from satellite remote sensing are crucial for observing changes on a global scale. An extensive global data set was created from field and satellite observations for investigating the relationship between PIC concentrations and differences in the remote sensing reflectance (Rrs) at green, red, and near-infrared (NIR) wavebands. Three color indices were defined: two as the relative height of Rrs(667) above a baseline running between Rrs(547) and an Rrs in the NIR (either 748 or 869 nm), and one as the difference between Rrs(547) and Rrs(667). All three color indices were found to explain over 90% of the variance in field-measured PIC. But, due to the lack of availability of Rrs(NIR) in the standard ocean color data products, most of the further analysis presented here was done using the color index determined from only two bands. The new two-band color index algorithm was found to retrieve PIC concentrations more accurately than the current standard algorithm used in generating global PIC data products. Application of the new algorithm to satellite imagery showed patterns on the global scale as revealed from field measurements. The new algorithm was more resistant to atmospheric correction errors and residual errors in sun glint corrections, as seen by a reduction in the speckling and patchiness in the satellite-derived PIC images.

Eddy covariance and biometric measurements show that a savanna ecosystem in Southwest China is a carbon sink

PubMed Central

Fei, Xuehai; Jin, Yanqiang; Zhang, Yiping; Sha, Liqing; Liu, Yuntong; Song, Qinghai; Zhou, Wenjun; Liang, Naishen; Yu, Guirui; Zhang, Leiming; Zhou, Ruiwu; Li, Jing; Zhang, Shubin; Li, Peiguang

2017-01-01

Savanna ecosystems play a crucial role in the global carbon cycle. However, there is a gap in our understanding of carbon fluxes in the savanna ecosystems of Southeast Asia. In this study, the eddy covariance technique (EC) and the biometric-based method (BM) were used to determine carbon exchange in a savanna ecosystem in Southwest China. The BM-based net ecosystem production (NEP) was 0.96 tC ha−1 yr−1. The EC-based estimates of the average annual gross primary productivity (GPP), ecosystem respiration (Reco), and net ecosystem carbon exchange (NEE) were 6.84, 5.54, and −1.30 tC ha−1 yr−1, respectively, from May 2013 to December 2015, indicating that this savanna ecosystem acted as an appreciable carbon sink. The ecosystem was more efficient during the wet season than the dry season, so that it represented a small carbon sink of 0.16 tC ha−1 yr−1 in the dry season and a considerable carbon sink of 1.14 tC ha−1 yr−1 in the wet season. However, it is noteworthy that the carbon sink capacity may decline in the future under rising temperatures and decreasing rainfall. Consequently, further studies should assess how environmental factors and climate change will influence carbon-water fluxes. PMID:28145459

The first true inorganic fullerenes?

NASA Astrophysics Data System (ADS)

Parilla, P. A.; Dillon, A. C.; Jones, K. M.; Riker, G.; Schulz, D. L.; Ginley, D. S.; Heben, M. J.

1999-01-01

Boron nitride and materials of composition MX2, where M is molybdenum or tungsten and X is sulphur or selenium, can form fullerene-like structures such as nested polyhedra or nanotubes. However, the analogy to the carbon fullerene family falls short because no small preferred structure akin to C60(ref. 5) has been found. We have discovered nano-octahedra of MoS2of discrete sizes in soots that we prepared by laser ablation of pressed MoS2targets. These nano-octahedra are much larger than C60structures, having edge lengths of about 4.0 and 5.0 nanometres, and may represent the first `inorganic fullerenes'.

Tc-99m-galactosyl-neoglycoalbumin (Tc-NGA) liver imaging: Potential application in liver transplantation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woodle, E.S.; Vera, D.R.; Ward, R.E.

1984-01-01

Tc-NGA is a hepatocyte receptor-specific imaging agent whose uptake by the liver has been shown to be dependent upon blood flow and receptor concentration. The combination of anatomic and physiologic information obtained with Tc-NGA may provide a new tool for studying hepatic function in liver transplant recipients. To evaluate the potential role of Tc-NGA in liver transplant recipients, studies were performed in four groups of pigs: controls (n=18); common bile duct (CBD) ligation (n=8); orthotopic liver transplant (n=9); and acute hepatic artery ligation (n=1). Serial studies performed in two animals with CBD ligation demonstrated normal imaging anatomy with minor changesmore » in the hepatic time-activity curves when compared to control studies. Studies in liver-transplanted animals showed significant changes in the hepatic time-activity curves during acute rejection and in preservation-related ischemic injury. Tc-NGA also demonstrated focal areas of hepatic infarction in a hepatic allograft within 24 hours of transplantation. The hepatic artery ligation study showed massive changes in the hepatic time-activity curve within two hours after ligation, with a diffuse decrease in hepatic activity. These results indicate that: (1) extrahepatic biliary tract obstruction causes only minor changes in Tc-NGA uptake; (2) Tc-NGA uptake by the liver is very sensitive to acute hepatic ischemia; (3) Tc-NGA may indicate the presence of preservation damage in the early postoperative period; and (4) Tc-NGA hepatic time-activity curves demonstrate significant changes during acute rejection.« less

Lung function declines in patients with pulmonary sarcoidosis and increased respiratory epithelial permeability to sup 99m Tc-DTPA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chinet, T.; Dusser, D.; Labrune, S.

1990-02-01

Respiratory epithelial clearance of {sup 99m}Tc-DTPA (RC-Tc-DTPA) and pulmonary function tests (PFT) were determined at intervals of 6 or 12 months in 37 untreated, nonsmoking patients with sarcoidosis over a period of 6 to 36 months. PFT included the measurements of total lung capacity (TLC), vital capacity (VC), FEV1, and diffusing capacity for carbon monoxide. No difference was found between the respiratory clearance of {sup 113m}In-DTPA (2.25 +/- 1.00%/min) and RC-Tc-DTPA (2.29 +/- 1.11%/min) in eight patients with pulmonary sarcoidosis. Pulmonary function decreased 15% or more in at least 2 function tests during 11 follow-up periods, but it remained stablemore » during 47 follow-up periods. In patients whose lung function deteriorated, RC-Tc-DTPA increased to 3.51 +/- 1.55%/min; in contrast, in patients whose lung function remained stable, regardless of the initial values, RC-Tc-DTPA was normal (1.00 +/- 0.50%/min; p less than 0.001). In eight patients who were treated with corticosteroids, RC-Tc-DTPA decreased from 3.48 +/- 1.31%/min to 1.56 +/- 0.64%/min (p less than 0.001), and PFT improved. We conclude that in nonsmokers with pulmonary sarcoidosis, increased RC-Tc-DTPA is not related to dissociation of 99mTc from DTPA, RC-Tc-DTPA is increased when pulmonary function decreases, and, when increased, RC-Tc-DTPA decreases with corticosteroid therapy.« less

Carbon speciation and surface tension of fog

USGS Publications Warehouse

Capel, P.D.; Gunde, R.; Zurcher, F.; Giger, W.

1990-01-01

The speciation of carbon (dissolved/particulate, organic/inorganic) and surface tension of a number of radiation fogs from the urban area of Zurich, Switzerland, were measured. The carbon species were dominated by "dissolved" organic carbon (DOC; i.e., the fraction that passes through a filter), which was typically present at levels of 40-200 mg/L. Less than 10% of the DOC was identified as specific individual organic compounds. Particulate organic carbon (POC) accounted for 26-41% of the mass of the particles, but usually less than 10% of the total organic carbon mass. Inorganic carbon species were relatively minor. The surface tensions of all the measured samples were less than pure water and were correlated with their DOC concentrations. The combination of high DOC and POC and low surface tension suggests a mechanism for the concentration of hydrophobic organic contaminants in the fog droplet, which have been observed by numerous investigators. ?? 1990 American Chemical Society.

Expanding the analyte set of the JPL Electronic Nose to include inorganic compounds

NASA Technical Reports Server (NTRS)

Ryan, M. A.; Homer, M. L.; Zhou, H.; Mannat, K.; Manfreda, A.; Kisor, A.; Shevade, A.; Yen, S. P. S.

2005-01-01

An array-based sensing system based on 32 polymer/carbon composite conductometric sensors is under development at JPL. Until the present phase of development, the analyte set has focuses on organic compounds and a few selected inorganic compounds, notably ammonia and hydrazine.

Enhancing cell growth and lutein productivity of Desmodesmus sp. F51 by optimal utilization of inorganic carbon sources and ammonium salt.

PubMed

Xie, Youping; Zhao, Xurui; Chen, Jianfeng; Yang, Xuqiu; Ho, Shih-Hsin; Wang, Baobei; Chang, Jo-Shu; Shen, Ying

2017-11-01

The type and concentration of inorganic carbon and nitrogen sources were manipulated to improve cell growth and lutein productivity of Desmodesmus sp. F51. Using nitrate as nitrogen source, the better cell growth and lutein accumulation were obtained under 2.5% CO 2 supply when compared to the addition of NaHCO 3 or Na 2 CO 3 . To solve the pH variation problem of ammonium consumption, the strategy of using dual carbon sources (NaHCO 3 and CO 2 ) was explored. A lower bicarbonate-C: ammonium-N ratio led to a lower culture pH as well as lower lutein productivity, but significantly enhanced the auto-flocculation efficiency of the microalgal cells. The highest biomass productivity (939mg/L/d) and lutein productivity (5.22mg/L/d) were obtained when the bicarbonate-C/ammonium-N ratio and ammonium-N concentration were 1:1 and 150mg/L, respectively. The lutein productivity of 5.22mg/L/d is the highest value ever reported in the literature using batch phototrophic cultivation. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

NASA Astrophysics Data System (ADS)

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

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

USGS Publications Warehouse

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

Transport and Fate of Organic and Inorganic Nitrogen from Biosolids leachates

NASA Astrophysics Data System (ADS)

Ilani, Talli; Trifonov, Pavel; Arye, Gilboa

2014-05-01

The use of biosolids as a means to ameliorate soil becomes prevalent in the last few years. In agricultural fields, the application of biosolids will be followed by irrigation; resulting in excessive leaching of the dissolved fraction of the organic matter. The dissolved organic matter (DOM) is one of the major players in the chemical, physical and biological processes in soils. The DOM mainly composed of dissolved organic carbon (DOC) and lower proportions of dissolved organic nitrogen (DON) and phosphate (DOP). The DON is considered to be the primary source of mineralisable nitrogen in the soil and can be used as an estimate of the nitrogen supplying capacity of the organic matter. Most of the researches which are dealing with nitrogen fate in terrestrial environments focused on its inorganic fractions (mainly nitrate and ammonium) and their transport toward the dipper soil layers. Since DON can be the source of the inorganic nitrogen (by providing nutrients and energy to nitrifying microbes, which in turn increases the nitrogen source for plants as nitrate), knowledge about the nature of its transport characteristics in the soil is important in the case of biosolids amendment. In addition, irrigation water quality (e.g. fresh water, wastewater or desalinized water) may significantly affect the transport and fate of the various nitrogen forms. The main objective of this study is to examine the fate and co-transport of organic and inorganics nitrogen, originating from biosolids leachates in the subsoil. The effect of water quality and flow rate under saturated steady-state flow is examined by a series of flow-through soil column experiments. The established breakthrough curves of the co-transport of total nitrogen, organic nitrogen (will be calculated from the differences between the total nitrogen measurements and the inorganic nitrogen measurements), nitrate, ammonium, dissolved organic carbon and chloride is presented and discussed.

Inorganic nanostructured materials for high performance electrochemical supercapacitors

NASA Astrophysics Data System (ADS)

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.

Inorganic nanostructured materials for high performance electrochemical supercapacitors.

PubMed

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

2014-02-21

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.

Olanzapine induced Q-Tc shortening.

PubMed

Shoja Shafti, Saeed; Fallah Jahromi, Parisa

2014-12-01

Prolongation of Q-Tc interval is commonly accepted as a surrogate marker for the ability of a drug to cause torsade de pointes. In the present study, safety of olanzapine versus risperidone was compared among a group of patients with schizophrenia to see the frequency of the electrocardiographic alterations induced by those atypical antipsychotics. Two hundred and sixty-eight female inpatients with schizophrenia entered in one of the two parallel groups to participate in an open study for random assignment to olanzapine (n = 148) or risperidone (n = 120). Standard 12-lead surface electrocardiogram (ECG) was taken from each patient at baseline, before initiation of treatment, and then at the end of management, just before discharge. The parameters that were assessed included heart rate (HR), P-R interval, QRS interval, Q-T interval (corrected = Q-Tc), ventricular activation time (VAT), ST segment, T wave, axis of QRS, and finally, interventricular conduction process. A total of 37.83% of cases in the olanzapine group and 30% in the risperidone group showed some Q-Tc changes; 13.51% and 24.32% of the patients in the olanzapine group showed prolongation and shortening of the Q-Tc, respectively, while changes in the risperidone group were restricted to only prolongation of Q-Tc. Comparison of means showed a significant increment in Q-Tc by risperidone (p = 0.02). Also, comparison of proportions in the olanzapine group showed significantly more cases with shortening of Q-Tc versus its prolongation (p = 0.01). No significant alterations with respect to other variables were evident. Olanzapine and risperidone had comparable potentiality for induction of Q-Tc changes, while production of further miscellaneous alterations in ECG was more observable in the olanzapine group compared with the risperidone group. Also shortening of Q-Tc was specific to olanzapine.

In vitro erythemal UV-A protection factors of inorganic sunscreens distributed in aqueous media using carnauba wax-decyl oleate nanoparticles.

PubMed

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.

EPA Science Inventory

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...

Biosynthetic inorganic chemistry.

PubMed

Lu, Yi

2006-08-25

Inorganic chemistry and biology can benefit greatly from each other. Although synthetic and physical inorganic chemistry have been greatly successful in clarifying the role of metal ions in biological systems, the time may now be right to utilize biological systems to advance coordination chemistry. One such example is the use of small, stable, easy-to-make, and well-characterized proteins as ligands to synthesize novel inorganic compounds. This biosynthetic inorganic chemistry is possible thanks to a number of developments in biology. This review summarizes the progress in the synthesis of close models of complex metalloproteins, followed by a description of recent advances in using the approach for making novel compounds that are unprecedented in either inorganic chemistry or biology. The focus is mainly on synthetic "tricks" learned from biology, as well as novel structures and insights obtained. The advantages and disadvantages of this biosynthetic approach are discussed.

Physiological response of a red tide alga (Skeletonema costatum) to nitrate enrichment, with special reference to inorganic carbon acquisition.

PubMed

Gao, Guang; Xia, Jianrong; Yu, Jinlan; Zeng, Xiaopeng

2018-02-01

A classical red tide alga Skeletonema costatum was cultured under various nitrate levels to investigate its physiological response to nitrate enrichment combined with CO 2 limitation. The higher nitrate levels increased content of photosynthetic pigments (Chl a and Chl c), electron transport rate in photosystem II, photosynthetic O 2 evolution, and thus growth rate in S. costatum. On the other hand, the lower CO 2 levels (3.5-4.4 μmol kg -1 seawater) and higher pH (8.56-8.63) values in seawater were observed under higher nitrate conditions. Redox activity of plasma membrane and carbonic anhydrase in S. costatum was enhanced to address the reduced CO 2 level at higher nitrate levels. In addition, the pH compensation point was enhanced and direct HCO 3 - use was induced at higher nitrate levels. These findings indicate that nitrate enrichment would stimulate the breakout of S. costatum dominated red tides via enhancing its photosynthetic performances, and maintain a quick growth rate under CO 2 limitation conditions through improving its inorganic carbon acquisition capability. Our study sheds light on the mechanisms of S. costatum defeating CO 2 limitation during algal bloom. Copyright © 2017 Elsevier Ltd. All rights reserved.

Oxygen Carbon Dynamics within the Hyporheic Zone of a Headwater Stream

NASA Astrophysics Data System (ADS)

Pennington, R.; Haggerty, R.; Wondzell, S. M.; Serchan, S. P.; Reeder, W. J.; Tonina, D.

2016-12-01

Streams and rivers influence global carbon fluxes; on an aerial basis, they have disproportionately high export rates compared to land. Various mechanisms exist for the movement of terrestrially derived carbon to the stream network including transport of organic and inorganic carbon with groundwater and hillslope runoff. A secondary process that has received little attention is carbon dynamics of hyporheic flow along flow paths that pass beneath the vegetated riparian zone. Through use of high frequency monitoring of dissolved inorganic carbon and dissolved oxygen we find that the riparian zone is a net source of carbon throughout the year. Increases in DIC relative stream water are generally more than double decreases in O2 on a molar basis. Metabolic quotients of C to O2 are close to 1.0, therefore respiration of dissolved or particulate organic carbon along flow paths would result in an equal magnitude increase in inorganic carbon to decrease in O2. Diffusion from the high CO2 soil atmosphere into hyporheic water has been considered, however 2-D reactive transport modeling using PFLOTRAN indicates that soil diffusion processes are unlikely to produce observed increases in carbon and that alternative transport mechanisms including root respiration or diel water level fluctuations are necessary for mass balance. Results of the analysis will feed into a comprehensive distributed model of the system that explores carbon dynamics at the reach scale.

Carbon cycling and net ecosystem production at an early stage of secondary succession in an abandoned coppice forest.

PubMed

Ohtsuka, Toshiyuki; Shizu, Yoko; Nishiwaki, Ai; Yashiro, Yuichiro; Koizumi, Hiroshi

2010-07-01

Secondary mixed forests are one of the dominant forest cover types in human-dominated temperate regions. However, our understanding of how secondary succession affects carbon cycling and carbon sequestration in these ecosystems is limited. We studied carbon cycling and net ecosystem production (NEP) over 4 years (2004-2008) in a cool-temperate deciduous forest at an early stage of secondary succession (18 years after clear-cutting). Net primary production of the 18-year-old forest in this study was 5.2 tC ha(-1 )year(-1), including below-ground coarse roots; this was partitioned into 2.5 tC ha(-1 )year(-1) biomass increment, 1.6 tC ha(-1 )year(-1) foliage litter, and 1.0 tC ha(-1 )year(-1) other woody detritus. The total amount of annual soil surface CO(2) efflux was 6.8 tC ha(-1 )year(-1), which included root respiration (1.9 tC ha(-1 )year(-1)) and heterotrophic respiration (RH) from soils (4.9 tC ha(-1 )year(-1)). The 18-year forest at this study site exhibited a great increase in biomass pool as a result of considerable total tree growth and low mortality of tree stems. In contrast, the soil organic matter (SOM) pool decreased markedly (-1.6 tC ha(-1 )year(-1)), although further study of below-ground detritus production and RH of SOM decomposition is needed. This young 18-year forest was a weak carbon sink (0.9 tC ha(-1 )year(-1)) at this stage of secondary succession. The NEP of this 18-year forest is likely to increase gradually because biomass increases with tree growth and with the improvement of the SOM pool through increasing litter and dead wood production with stand development.

Persistence of organic carbon in heated aerosol residuals measured during Tropical Composition Cloud and Climate Coupling (TC4)

NASA Astrophysics Data System (ADS)

Thornberry, T.; Froyd, K. D.; Murphy, D. M.; Thomson, D. S.; Anderson, B. E.; Thornhill, K. L.; Winstead, E. L.

2010-05-01

The Particle Analysis by Laser Mass Spectrometry (PALMS) single particle mass spectrometer was used to analyze the composition of the nonvolatile fraction of atmospheric aerosol in a number of different environments. The mass spectra of individual particles sampled through an inlet section heated to 300°C were compared to unheated particles during flights of the NASA DC-8 aircraft during the Tropical Composition Cloud and Climate Coupling (TC4) mission. Comparisons are presented of measurements made in the marine boundary layer, the free troposphere, and the continental boundary layer over the Colombian jungle. The heated section completely removed sulfate from the aerosols except for sodium sulfate and related compounds in sea salt particles. Organic material in sea salt particles was observed to be less volatile than chlorine. Biomass burning particles were more likely to survive heating than other mixed sulfate-organic particles. For all particle types, there was a significant contribution to the residues from carbonaceous material other than elemental carbon. These results demonstrate the remaining compositional complexity of aerosol residuals that survive heating in a thermal denuder.

Electrochemical sensor for sensitive detection of paracetamol based on novel multi-walled carbon nanotubes-derived organic-inorganic material.

PubMed

Hui, Junmin; Li, Wenjuan; Guo, Yanlei; Yang, Zhu; Wang, Yingxiong; Yu, Chao

2014-03-01

A new electrochemical sensor based on a novel organic-inorganic material (PNFCTs) was proposed for detection of paracetamol in this paper. First, PNFCTs were prepared with multi-walled carbon nanotubes (MWNTs) and a derivative of 3,4,9,10-perylenetetracarboxylic dianhydride (PTC-NH2) via cross-linking method. Then, PNFCTs were coated onto the surface of the glassy carbon electrode (GCE) to form porous organic conducting polymer films (PNFCTs/GCE), which could not only increase the loading of paracetamol efficiently but also provide an interface with exceptional electrical conductivity for paracetamol. Finally, gold nanoparticles (GNPs) were attached to the electrode surface through electrodepositing method, which obtained GNPs/PNFCTs/GCE electrode. The electrochemical behavior of paracetamol on GNPs/PNFCTs/GCE was explored by cyclic voltammetrys (CVs) and differential pulse voltammograms (DPVs). The results showed that the GNPs/PNFCTs/GCE exhibited excellent electrocatalytic activity to paracetamol, which should be attributed to remarkable properties of the new composite nanomaterials with porous nanostructure and exceptional electrical conductivity. The wide liner range and detection limit were 0.3-575 and 0.1 μM, respectively. Finally, it was successfully used to detect paracetamol in dilution human serum and commercial tablets. The sensor shows great promise for simple, sensitive, and selective detection paracetamol and provides a promising approach in paracetamol clinical research and overdose diagnostic applications.

Comparison and evaluation of in situ and filter carbon measurements at the Fresno Supersite

NASA Astrophysics Data System (ADS)

Watson, John G.; Chow, Judith C.

2002-11-01

The Fresno Supersite in Fresno, California, USA, acquires in situ 5- to 60-min average PM2.5 organic carbon (OC), elemental carbon (EC), and total carbon (TC) measurements by the following methods: (1) thermal evolution carbon analyzer for organic, elemental, and total carbon; (2) single-wavelength and seven-color aethalometer for black carbon (BC); and (3) photoionization for particle-bound polycyclic aromatic hydrocarbons. Twenty-four-hour average PM2.5 filter-based measurements include (1) nondenuded quartz filters with no backup filter in a PM2.5 Federal Reference Method (FRM) sampler; (2) quartz filters behind an organic carbon denuder with a quartz backup filter in a Reference Ambient Aerosol Sampler (RAAS); (3) nondenuded quartz filters with backup filter in a RAAS; and (4) nondenuded quartz filters with no backup filter in a sequential filter sampler. Filter samples are analyzed after sampling by the Interagency Monitoring of Protected Visual Environments (IMPROVE) thermal/optical reflectance carbon analysis protocol. Collocated measurements are examined for year 2000. Measurement equivalence is found for PM2.5 mass, light transmission, and TC between the FRM and RAAS speciation samplers. The average ratios of front filter carbon between the denuded and nondenuded channels in the RAAS sampler are 0.83 ± 0.19 for TC, 0.81 ± 0.20 for OC, and 1.01 ± 0.33 for EC. The average differences for TC and OC are low (1.2 to 1.4 μg m-3) and are comparable to the measurement uncertainties. Continuous thermal evolution carbon measurements are not comparable to filter measurements. Aethalometer BC and filter EC are highly correlated, but filter EC is consistently 20-25% higher than continuous aethalometer BC. Pairwise comparisons show filter EC measurements acquired in this study are predictable from aethalometer BC measurements.

Inverse correlation between quasiparticle mass and Tc in a cuprate high-Tc superconductor

PubMed Central

Putzke, Carsten; Malone, Liam; Badoux, Sven; Vignolle, Baptiste; Vignolles, David; Tabis, Wojciech; Walmsley, Philip; Bird, Matthew; Hussey, Nigel E.; Proust, Cyril; Carrington, Antony

2016-01-01

Close to a zero-temperature transition between ordered and disordered electronic phases, quantum fluctuations can lead to a strong enhancement of electron mass and to the emergence of competing phases such as superconductivity. A correlation between the existence of such a quantum phase transition and superconductivity is quite well established in some heavy fermion and iron-based superconductors, and there have been suggestions that high-temperature superconductivity in copper-oxide materials (cuprates) may also be driven by the same mechanism. Close to optimal doping, where the superconducting transition temperature Tc is maximal in cuprates, two different phases are known to compete with superconductivity: a poorly understood pseudogap phase and a charge-ordered phase. Recent experiments have shown a strong increase in quasiparticle mass m* in the cuprate YBa2Cu3O7-δ as optimal doping is approached, suggesting that quantum fluctuations of the charge-ordered phase may be responsible for the high-Tc superconductivity. We have tested the robustness of this correlation between m* and Tc by performing quantum oscillation studies on the stoichiometric compound YBa2Cu4O8 under hydrostatic pressure. In contrast to the results for YBa2Cu3O7-δ, we find that in YBa2Cu4O8, the mass decreases as Tc increases under pressure. This inverse correlation between m* and Tc suggests that quantum fluctuations of the charge order enhance m* but do not enhance Tc. PMID:27034989

Molecular and biochemical characterisation of two aspartic proteinases TcAP1 and TcAP2 from Theobroma cacao seeds.

PubMed

Laloi, Maryse; McCarthy, James; Morandi, Olivia; Gysler, Christof; Bucheli, Peter

2002-09-01

Aspartic proteinase (EC 3.4.23) activity plays a pivotal role in the degradation of Theobroma cacao L. seed proteins during the fermentation step of cacao bean processing. Therefore, this enzyme is believed to be critical for the formation of the peptide and amino acid cocoa flavor precursors that occurs during fermentation. Using cDNA cloning and northern blot analysis, we show here that there are at least two distinct aspartic proteinase genes ( TcAP1 and TcAP2) expressed during cacao seed development. Both genes are expressed early during seed development and their mRNA levels decrease towards the end of seed maturation. TcAP2 is expressed at a much higher level than TcAP1, although the expression of TcAP1 increases slightly during germination. The proteins encoded by TcAP1 and TcAP2 are relatively different from each other (73% identity). This, and the fact that the two corresponding genes have different expression patterns, suggests that the TcAP1 and TcAP2 proteins may have different functions in the maturing seeds and during germination. Because the TcAP2 gene is expressed at a much higher level during seed development than TcAP1, it is likely that the TcAP2 protein is primarily responsible for the majority of the industrially important protein hydrolysis that occurs during cacao bean fermentation. Finally, TcAP2 has been functionally expressed in the yeast Yarrowia lipolytica. The secreted recombinant protein is able to hydrolyse bovine haemoglobin at acidic pH and is sensitive to pepstatin A, confirming that TcAP2 encodes an aspartic proteinase, and strongly suggests that this gene encodes the well-characterized aspartic proteinase of mature cacao seeds.

Effects of FlAsH/Tetracysteine (TC) tag on PrP proteolysis and PrPres formation by TC-scanning

PubMed Central

Taguchi, Yuzuru; Hohsfield, Lindsay A.; Hollister, Jason R.

2014-01-01

The FlAsH/tetracysteine (FlAsH/TC) tag is a powerful tool for fluorescent labeling of proteins. However, even small tags such as FlAsH/TC could alter the behavior of the tagged proteins, especially if the insertion occurs at internal sites. Defining the influence of FlAsH/TC on nearby protein-protein interactions might aid in selecting appropriate positions for internal TC insertions and allow the exploitation of serial FlAsH/TC insertions (TC-scanning) as a probe to characterize sites of protein-protein interaction. To explore this application in the context of substrate-protease interactions, we analyzed the effect of FlAsH/TC insertions on proteolysis of cellular prion protein (PrPsen) in in vitro reactions and generation of the C1 metabolic fragment of PrPsen in live neuroblastoma cells. The influence of FlAsH/TC insertion was evaluated by TC-scanning across the cleavage sites of each protease. The results showed that FlAsH/TC inhibited protease cleavage only within limited ranges of the cleavage sites that varied from about 1 to 6 residues-wide depending on the protease, providing an estimate of the PrP residues interacting with each protease. TC-scanning was also used to probe a different type of protein-protein interaction, the conformational conversion of FlAsH-PrPsen to the prion disease-associated isoform, PrPres. PrP constructs with FlAsH/TC insertions at residues 90–96 but not 97–101 were converted to FlAsH-PrPres, identifying a boundary separating loosely versus compactly folded regions of PrPres. Our observations demonstrate that TC-scanning with the FlAsH/TC tag can be a versatile method for probing protein-protein interactions and folding processes. PMID:23943295

Telecom 2-B and 2-C (TC2B and TC2C)

NASA Technical Reports Server (NTRS)

Dulac, J.; Alvarez, H.

1991-01-01

The DSN (Deep Space Network) mission support requirements for Telecom 2-B and 2-C (TC2B and TC2C) are summarized. These Telecom missions will provide high-speed data link applications, telephone, and television service between France and overseas territories as a follow-on to TC2A. Mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; support parameters for telemetry, command and support systems; and tracking support responsibility.

Trypanosoma cruzi diversity in the Gran Chaco: mixed infections and differential host distribution of TcV and TcVI.

PubMed

Monje-Rumi, María M; Brandán, Cecilia Pérez; Ragone, Paula G; Tomasini, Nicolás; Lauthier, Juan J; Alberti D'Amato, Anahí M; Cimino, Rubén O; Orellana, Viviana; Basombrío, Miguel A; Diosque, Patricio

2015-01-01

The transmission cycles of Trypanosoma cruzi in the Gran Chaco are complex networks involving domestic and wild components, whose interrelationships are not well understood. Knowing the circuit of transmission of the different Discrete Typing Units (DTUs) of T. cruzi in the complex environment of the Chaco region is relevant to understanding how the different components (reservoirs, vectors, ecotopes) interact. In the present study we identified the DTUs infecting humans and dogs in two rural areas of the Gran Chaco in Argentina, using molecular methods which avoid parasite culture. Blood samples of humans and dogs were typified by PCR-DNA blotting and hybridization assays with five specific DNA probes (TcI, TcII, TcIII, TcV and TcVI). PCR analyses were performed on seropositive human and dog samples and showed the presence of T. cruzi DNA in 41.7% (98/235) and 53% (35/66) samples, respectively. The identification of infective DTUs was determined in 83.6% (82/98) and 91.4% (32/35) in human and dog samples, respectively. Single infections (36.7% - 36/98) and a previously not detected high proportion of mixed infections (47.9% - 47/98) were found. In a 15.3% (15/98) of samples the infecting DTU was not identified. Among the single infections TcV was the most prevalent DTU (30.6% - 30/98) in human samples; while TcVI (42.8% - 15/35) showed the highest prevalence in dog samples. TcV/TcVI was the most prevalent mixed infection in humans (32.6% - 32/98); and TcI/TcVI (14.3% - 5/35) in dogs. Significant associations between TcV with humans and TcVI with dogs were detected. For the first time, the presence of TcIII was detected in humans from this region. The occurrence of one human infected whit TcIII (a principally wild DTU) could be suggested the emergence of this, in domestic cycles in the Gran Chaco. Copyright © 2014 Elsevier B.V. All rights reserved.

Insights into the unique functionality of inorganic micro/nanoparticles for versatile ultrasound theranostics.

PubMed

Qian, Xiaoqin; Han, Xiaoxia; Chen, Yu

2017-10-01

The clinical ultrasound (US)-based theranostic biomedicine suffers from the critical issue that traditional microbubbles (MBs) have lots of drawbacks such as low stability, large particle size, difficult structural control, etc. The unique composition, structure and functionality of inorganic micro/nanoplatforms have shown their great prospect for solving these critical issues and drawbacks of traditional organic MBs. This review summarizes and discusses the state-of-art development on exploring inorganic micro/nanoparticles for versatile US-based biomedical applications, ranging from US imaging, photoacoustic imaging, sonodynamic therapy, high intensity-focused US ablation and US-triggered chemotherapy. These inorganic micro/nanoplatforms include silica-based particles, Au, carbon nanotubes, TiO 2 , manganese oxide, iron oxide, Prussian blue, inorganic gas-generating nanoparticles and their versatile composite micro/nanosystems. Especially, their unique structure/composition-functionality relationships and biocompatibility/biosafety in US-based theranostics have been discussed and revealed in detail. Their facing challenges and future developments are finally discussed to promote their further clinical translations. It is highly expected that these inorganic micro/nanoplatforms will enter the clinical stage to benefit the personalized theranostics biomedicine based on their unique functionalities and high performance as necessarily required in US-based theranostics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sampling and analytical methods of stable isotopes and dissolved inorganic carbon from CO2 injection sites

NASA Astrophysics Data System (ADS)

van Geldern, Robert; Myrttinen, Anssi; Becker, Veith; Barth, Johannes A. C.

2010-05-01

The isotopic composition (δ13C) of dissolved inorganic carbon (DIC), in combination with DIC concentration measurements, can be used to quantify geochemical trapping of CO2 in water. This is of great importance in monitoring the fate of CO2 in the subsurface in CO2 injection projects. When CO2 mixes with water, a shift in the δ13C values, as well as an increase in DIC concentrations is observed in the CO2-H2O system. However, when using standard on-site titration methods, it is often challenging to determining accurate in-situ DIC concentrations. This may be due to CO2 degassing and CO2-exchange between the sample and the atmosphere during titration, causing a change in the pH value or due to other unfavourable conditions such as turbid water samples or limited availability of fluid samples. A way to resolve this problem is by simultaneously determining the DIC concentration and carbon isotopic composition using a standard continuous flow Isotope Ratio Mass Spectrometry (CF-IRMS) setup with a Gasbench II coupled to Delta plusXP mass spectrometer. During sampling, in order to avoid atmospheric contact, water samples taken from the borehole-fluid-sampler should be directly transferred into a suitable container, such as a gasbag. Also, to avoid isotope fractionation due to biological activity in the sample, it is recommended to stabilize the gasbags prior to sampling with HgCl2 for the subsequent stable isotope analysis. The DIC concentration of the samples can be determined from the area of the sample peaks in a chromatogram from a CF-IRMS analysis, since it is directly proportional to the CO2 generated by the reaction of the water with H3PO4. A set of standards with known DIC concentrations should be prepared by mixing NaHCO3 with DIC free water. Since the DIC concentrations of samples taken from CO2 injection sites are expected to be exceptionally high due to the additional high amounts of added CO2, the DIC concentration range of the standards should be set high

Comparison of Tc-99m maraciclatide and Tc-99m sestamibi molecular breast imaging in patients with suspected breast cancer.

PubMed

O'Connor, Michael K; Morrow, Melissa M B; Hunt, Katie N; Boughey, Judy C; Wahner-Roedler, Dietlind L; Conners, Amy Lynn; Rhodes, Deborah J; Hruska, Carrie B

2017-12-01

Molecular breast imaging (MBI) performed with 99m Tc sestamibi has been shown to be a valuable technique for the detection of breast cancer. Alternative radiotracers such as 99m Tc maraciclatide may offer improved uptake in breast lesions. The purpose of this study was to compare relative performance of 99m Tc sestamibi and 99m Tc maraciclatide in patients with suspected breast cancer, using a high-resolution dedicated gamma camera for MBI. Women with breast lesions suspicious for malignancy were recruited to undergo two MBI examinations-one with 99m Tc sestamibi and one with 99m Tc maraciclatide. A radiologist interpreted MBI studies in a randomized, blinded fashion to assign an assessment score (1-5) and measured lesion size. Lesion-to-background (L/B) ratio was measured with region-of-interest analysis. Among 39 analyzable patients, 21 malignant tumors were identified in 21 patients. Eighteen of 21 tumors (86%) were seen on 99m Tc sestamibi MBI and 19 of 21 (90%) were seen on 99m Tc maraciclatide MBI (p = 1). Tumor extent measured with both radiopharmaceuticals correlated strongly with pathologic size ( 99m Tc sestamibi, r = 0.84; 99m Tc maraciclatide, r = 0.81). The L/B ratio in detected breast cancers was similar for the two radiopharmaceuticals: 1.55 ± 0.36 (mean ± S.D.) for 99m Tc sestamibi and 1.62 ± 0.37 (mean ± S.D.) for 99m Tc maraciclatide (p = 0.53). No correlation was found between the L/B ratio and molecular subtype for 99m Tc sestamibi (r s  = 0.12, p = 0.63) or 99m Tc maraciclatide (r s  = -0.12, p = 0.64). Of 20 benign lesions, 10 (50%) were seen on 99m Tc sestamibi and 9 of 20 (45%) were seen on 99m Tc maraciclatide images (p = 0.1). The average L/B ratio for benign lesions was 1.34 ±0.40 (mean ±S.D.) for 99m Tc sestamibi and 1.41 ±0.52 (mean ±S.D.) for 99m Tc maraciclatide (p = 0.75). Overall diagnostic performance was similar for both radiopharmaceuticals. AUC from ROC

Imaging of irradiated liver with Tc-99m-sulfur colloid and Tc-99m-IDA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gelfand, M.J.; Saha, S.; Aron, B.S.

1981-09-01

In three cases, irradiated regions of liver failed to concentrate Tc-99m-sulfur colloid. In two of these three, imaging with Tc-99m-acetanilide iminodiacetic acid (IDA) agents within five days showed near normal hepatic uptake of this hepatobiliary imaging agent. The hepatic parenchymal cells may be imaged with Tc-99m-IDA in some irradiated regions of liver, despite loss of reticuloendothelial cell function.

3D hybrid carbon composed of multigraphene bridged by carbon chains

NASA Astrophysics Data System (ADS)

Liu, Lingyu; Hu, Meng; Liu, Chao; Shao, Cancan; Pan, Yilong; Ma, Mengdong; Wu, Yingju; Zhao, Zhisheng; Gao, Guoying; He, Julong

2018-01-01

The element carbon possesses various stable and metastable allotropes; some of them have been applied in diverse fields. The experimental evidences of both carbon chain and graphdiyne have been reported. Here, we reveal the mystery of an enchanting carbon allotrope with sp-, sp2-, and sp3-hybridized carbon atoms using a newly developed ab initio particle-swarm optimization algorithm for crystal structure prediction. This crystalline allotrope, namely m-C12, can be viewed as braided mesh architecture interwoven with multigraphene and carbon chains. The m-C12 meets the criteria for dynamic and mechanical stabilities and is energetically more stable than carbyne and graphdiyne. Analysis of the B/G and Poisson's ratio indicates that this allotrope is ductile. Notably, m-C12 is a superconducting carbon with Tc of 1.13 K, which is rare in the family of carbon allotropes.

Amyloidosis of heart and liver: comparison of Tc-99m pyrophosphate and Tc-99m methylene diphosphonate for detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, V.W.; Caldarone, A.G.; Falk, R.H.

1983-07-01

A prospective, comparative study was made of the efficacy of technetium-99m pyrophosphate (Tc PYP) and technetium-99m methylene diphosphonate (Tc MDP) in detecting soft-tissue amyloidois. Tc PYP and Tc MDP scans were obtained within ten-day intervals in seven patients with histologically proven amyloidosis. Tc PYP was a better scanning agent for soft-tissue amyloidosis in all patients. Cardiac and hepatic involvement were proved by autopsy in one patient. Involvement of the heart was confirmed by echocardiography in five patients. The potential use of tc PYP scannning as a screening test for soft-tissue amyloidosis is discussed.

Sorption of pollutants by porous carbon, carbon nanotubes and fullerene- an overview.

PubMed

Gupta, Vinod K; Saleh, Tawfik A

2013-05-01

The quality of water is continuously deteriorating due to its increasing toxic threat to humans and the environment. It is imperative to perform treatment of wastewater in order to remove pollutants and to get good quality water. Carbon materials like porous carbon, carbon nanotubes and fullerene have been extensively used for advanced treatment of wastewaters. In recent years, carbon nanomaterials have become promising adsorbents for water treatment. This review attempts to compile relevant knowledge about the adsorption activities of porous carbon, carbon nanotubes and fullerene related to various organic and inorganic pollutants from aqueous solutions. A detailed description of the preparation and treatment methods of porous carbon, carbon nanotubes and fullerene along with relevant applications and regeneration is also included.

Dissolved inorganic carbon and total alkalinity of a Hawaiian fringing reef: chemical techniques for monitoring the effects of ocean acidification on coral reefs

NASA Astrophysics Data System (ADS)

Lantz, C. A.; Atkinson, M. J.; Winn, C. W.; Kahng, S. E.

2014-03-01

There is an interest in developing approaches to "ecosystem-based" management for coral reefs. One aspect of ecosystem performance is to monitor carbon metabolism of whole communities. In an effort to explore robust techniques to monitor the metabolism of fringing reefs, especially considering the possible effects of ocean acidification, a yearlong study of the carbonate chemistry of a nearshore fringing reef in Hawaii was conducted. Diurnal changes in seawater carbonate chemistry were measured once a week in an algal-dominated and a coral-dominated reef flat on the Waimanalo fringing reef, Hawaii, from April of 2010 until May of 2011. Calculated rates of gross primary production (GPP) and net community calcification ( G) were similar to previous estimates of community metabolism for other coral reefs (GPP 971 mmol C m-2 d-1; G 186 mmol CaCO3 m-2 d-1) and indicated that this reef was balanced in terms of organic metabolism, exhibited net calcification, and was a net source of CO2 to the atmosphere. Average slopes of total alkalinity versus dissolved inorganic carbon (TA-DIC slope) for the coral-dominated reef flat exhibited a greater calcification-to-net photosynthesis ratio than for the algal-dominated reef flat (coral slope vs. algal slope). Over the course of the time series, TA-DIC slopes remained significantly different between sites and were not correlated with diurnal averages in reef-water residence time or solar irradiance. These characteristic slopes for each reef flat reflect the relationship between carbon and carbonate community metabolism and can be used as a tool to monitor ecosystem function in response to ocean acidification.

Applicability of plasmid calibrant pTC1507 in quantification of TC1507 maize: an interlaboratory study.

PubMed

Meng, Yanan; Liu, Xin; Wang, Shu; Zhang, Dabing; Yang, Litao

2012-01-11

To enforce the labeling regulations of genetically modified organisms (GMOs), the application of DNA plasmids as calibrants is becoming essential for the practical quantification of GMOs. This study reports the construction of plasmid pTC1507 for a quantification assay of genetically modified (GM) maize TC1507 and the collaborative ring trial in international validation of its applicability as a plasmid calibrant. pTC1507 includes one event-specific sequence of TC1507 maize and one unique sequence of maize endogenous gene zSSIIb. A total of eight GMO detection laboratories worldwide were invited to join the validation process, and test results were returned from all eight participants. Statistical analysis of the returned results showed that real-time PCR assays using pTC1507 as calibrant in both GM event-specific and endogenous gene quantifications had high PCR efficiency (ranging from 0.80 to 1.15) and good linearity (ranging from 0.9921 to 0.9998). In a quantification assay of five blind samples, the bias between the test values and true values ranged from 2.6 to 24.9%. All results indicated that the developed pTC1507 plasmid is applicable for the quantitative analysis of TC1507 maize and can be used as a suitable substitute for dried powder certified reference materials (CRMs).

Effect of Dietary Intake of Stable Iodine on Dose-per-unit-intake Factors for 99Tc

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strom, Daniel J.

It is well-known that the human thyroid concentrates iodine more than 100 times the concentration in plasma. Also well-known is the fact that large amounts of stable iodine in the diet can limit thyroid uptake of total iodine; this is the basis for administering potassium iodide following a release of radioiodine from a nuclear reactor accident or nuclear weapon detonation. Many researchers have shown enhanced concentrations of both organic and inorganic iodine in saliva and breast milk. Technetium-99 is a long-lived (231,000 year half-life) radionuclide of concern in the management of high-level radioactive waste. There is no doubt that 99Tc,more » if it is in groundwater, will be found in the chemical form of pertechnetate, 99TcO4?. Pertechnetate is a large anion, almost identical in size to iodide, I?. The nuclear medicine literature shows that pertechnetate concentrates in the thyroid, salivary glands, and lactating breast in addition to the stomach, liver, and alimentary tract as currently recognized by the International Commission on Radiological Protection (ICRP). The fact that large intakes of stable iodine (127I) in the diet limit uptake of iodine by the thyroid leads one to generalize that stable iodine in the diet may also limit thyroid uptake of pertechnetate. While there is at least one report that iodine in the diet blocks uptake of 99mTcO4? by the thyroid and salivary glands (which have the same Na/I symporter, the biochemical concentration mechanism), the level of protective effect seen for blocking radioactive iodine is not expected for 99TcO4? because pertechnetate does not become organically bound in the thyroid and thus is not retained for months the way iodide is. While it does account for Tc concentration in the thyroid, the existing ICRP biokinetic model for technetium does not take enhanced concentrations in salivary gland and breast tissue into account. From the survey of the nuclear medicine literature, it is not possible to compute the

Achieving high time-resolution with a new flow-through type analyzer for total inorganic carbon in seawater.

PubMed

Kimoto, Hideshi; Nozaki, Ken; Kudo, Setsuko; Kato, Ken; Negishi, Akira; Kayanne, Hajime

2002-03-01

A fully automated, continuous-flow-through type analyzer was developed to observe rapid changes in the concentration of total inorganic carbon (CT) in coastal zones. Seawater and an H3PO4 solution were fed into the analyzer's mixing coil by two high-precision valveless piston pumps. The CO2 was stripped from the seawater and moved into a carrier gas, using a newly developed continuous-flow-through CO2 extractor. A mass flow controller was used to assure a precise flow rate of the carrier gas. The CO2 concentration was then determined with a nondispersive infrared gas analyzer. This analyzer achieved a time-resolution of as good as 1 min. In field experiments on a shallow reef flat of Shiraho (Ishigaki Island, Southwest Japan), the analyzer detected short-term, yet extreme, variations in CT which manual sampling missed. Analytical values obtained by the analyzer on the boat were compared with those determined by potentiometric titration with a closed cell in a laboratory: CT(flow-through) = 0.980 x CT(titration) + 38.8 with r2 = 0.995 (n = 34; September 1998).

Biological and geochemical controls on diel dissolved inorganic carbon cycling in a low-order agricultural stream: implications for reach scales and beyond

USGS Publications Warehouse

Tobias, Craig; Böhlke, John Karl

2011-01-01

Movement of dissolved inorganic carbon (DIC) through the hydrologic cycle is an important component of global carbon budgets, but there is considerable uncertainty about the controls of DIC transmission from landscapes to streams, and through river networks to the oceans. In this study, diel measurements of DIC, d13C-DIC, dissolved oxygen (O2), d18O-O2, alkalinity, pH, and other parameters were used to assess the relative magnitudes of biological and geochemical controls on DIC cycling and flux in a nutrient-rich, net autotrophic stream. Rates of photosynthesis (P), respiration (R), groundwater discharge, air–water exchange of CO2, and carbonate precipitation/dissolution were quantified through a time-stepping chemical/isotope (12C and 13C, 16O and 18O) mass balance model. Groundwater was the major source of DIC to the stream. Primary production and carbonate precipitation were equally important sinks for DIC removed from the water column. The stream was always super-saturated with respect to carbonate minerals, but carbonate precipitation occurred mainly during the day when P increased pH. We estimated more than half (possibly 90%) of the carbonate precipitated during the day was retained in the reach under steady baseflow conditions. The amount of DIC removed from the overlying water through carbonate precipitation was similar to the amount of DIC generated from R. Air–water exchange of CO2 was always from the stream to the atmosphere, but was the smallest component of the DIC budget. Overall, the in-stream DIC reactions reduced the amount of CO2 evasion and the downstream flux of groundwater-derived DIC by about half relative to a hypothetical scenario with groundwater discharge only. Other streams with similar characteristics are widely distributed in the major river basins of North America. Data from USGS water quality monitoring networks from the 1960s to the 1990s indicated that 40% of 652 stream monitoring stations in the contiguous USA were at or above

Theoretical Modeling of (99)Tc NMR Chemical Shifts.

PubMed

Hall, Gabriel B; Andersen, Amity; Washton, Nancy M; Chatterjee, Sayandev; Levitskaia, Tatiana G

2016-09-06

Technetium-99 (Tc) displays a rich chemistry due to its wide range of accessible oxidation states (from -I to +VII) and ability to form coordination compounds. Determination of Tc speciation in complex mixtures is a major challenge, and (99)Tc nuclear magnetic resonance (NMR) spectroscopy is widely used to probe chemical environments of Tc in odd oxidation states. However, interpretation of (99)Tc NMR data is hindered by the lack of reference compounds. Density functional theory (DFT) calculations can help to fill this gap, but to date few computational studies have focused on (99)Tc NMR of compounds and complexes. This work evaluates the effectiveness of both pure generalized gradient approximation and their corresponding hybrid functionals, both with and without the inclusion of scalar relativistic effects, to model the (99)Tc NMR spectra of Tc(I) carbonyl compounds. With the exception of BLYP, which performed exceptionally well overall, hybrid functionals with inclusion of scalar relativistic effects are found to be necessary to accurately calculate (99)Tc NMR spectra. The computational method developed was used to tentatively assign an experimentally observed (99)Tc NMR peak at -1204 ppm to fac-Tc(CO)3(OH)3(2-). This study examines the effectiveness of DFT computations for interpretation of the (99)Tc NMR spectra of Tc(I) coordination compounds in high salt alkaline solutions.

The carbonic anhydrase CAH1 is an essential component of the carbon-concentrating mechanism in Nannochloropsis oceanica.

PubMed

Gee, Christopher W; Niyogi, Krishna K

2017-04-25

Aquatic photosynthetic organisms cope with low environmental CO 2 concentrations through the action of carbon-concentrating mechanisms (CCMs). Known eukaryotic CCMs consist of inorganic carbon transporters and carbonic anhydrases (and other supporting components) that culminate in elevated [CO 2 ] inside a chloroplastic Rubisco-containing structure called a pyrenoid. We set out to determine the molecular mechanisms underlying the CCM in the emerging model photosynthetic stramenopile, Nannochloropsis oceanica , a unicellular picoplanktonic alga that lacks a pyrenoid. We characterized CARBONIC ANHYDRASE 1 ( CAH1 ) as an essential component of the CCM in N. oceanica CCMP1779. We generated insertions in this gene by directed homologous recombination and found that the cah1 mutant has severe defects in growth and photosynthesis at ambient CO 2 We identified CAH1 as an α-type carbonic anhydrase, providing a biochemical role in CCM function. CAH1 was found to localize to the lumen of the epiplastid endoplasmic reticulum, with its expression regulated by the external inorganic carbon concentration at both the transcript and protein levels. Taken together, these findings show that CAH1 is an indispensable component of what may be a simple but effective and dynamic CCM in N. oceanica .

Assessment of submarine groundwater discharge and associated dissolved inorganic carbon into a coastal wetland, western Taiwan via time-series observations of 222Rn

NASA Astrophysics Data System (ADS)

Hsu, Feng-Hsin; Su, Chih-Chieh; Wang, Pei-Ling

2017-04-01

We investigated submarine groundwater discharge (SGD) and associated dissolved inorganic carbon flux into the Gaomei wetland, which is located south of the Tachia river's mouth, western Taiwan. This area is characterized by a great tidal range (over 3 m at spring tide) and a shallow unconfined aquifer (˜2 m below the seafloor) with high groundwater recharging rates (over 500 mm yr-1) in the hinterland. In this study we argue that in the Gaomei wetland, tidal pumping causes an exchanging between groundwater and seawater, resulting in an overall dissolved inorganic carbon (DIC) flux into the wetland. Time-series observations of 222Rn were conducted over 2 tidal cycles in both dry (May of 2014) and wet seasons (August of 2014) seasons at a station 500 m offshore. Our result shows a good response to tidal fluctuation with higher 222Rn activities at low tide and lower 222Rn activities at high tide. Based on a 222Rn mass balance model taking all sources and sinks into account, we estimated a SGD flux ranging from -3.86 to 69 cm d-1 with slightly higher fluxes during the wet season (average SGD flux 22 cm d-1) compared to the dry season (average SGD flux 16 cm d-1). Our negative SGD flux estimates observed during high tides suggest that seawater infiltrates into the sediments during flood tide and discharges during ebb tide, proving the concept of seawater exchange across the water-sediment interface. The overall SGD-borne DIC fluxes range between 1.82×106 and 2.48×106 mol d-1 in dry and wet seasons, respectively, that are 26 % and 36 % of the river-induced DIC fluxes. Such an export of DIC flux from the groundwater (or recycled seawater) might have an impact on coastal biogeochemistry in the Gaomei wetland.

The Phosphatidylinositol 3-kinase Class III Complex Containing TcVps15 and TcVps34 Participates in Autophagy in Trypanosoma cruzi.

PubMed

Schoijet, Alejandra C; Sternlieb, Tamara; Alonso, Guillermo D

2017-05-01

Autophagy is a degradative process by which eukaryotic cells digest their own components to provide aminoacids that may function as energy source under nutritional stress conditions. There is experimental evidence for autophagy in parasitic protists belonging to the family Trypanosomatidae. However, few proteins implicated in this process have been characterized so far in these parasites. Moreover, it has been shown that autophagy is involved in Trypanosoma cruzi differentiation and thus might have a role in pathogenicity. Here, we report the cloning and biochemical characterization of TcVps15. In addition, we demonstrate that TcVps15 interact with the PI3K TcVps34 and that both proteins associate with cellular membranes. Under nutritional stress conditions, TcVps15 and TcVps34 modify their subcellular distribution showing a partial co-localization in autophagosomes with TcAtg8.1 and using an active site TcVps15-mutated version (TcVps15-K219D-HA) we demonstrated that this relocalization depends on the TcVps15 catalytic activity. Overexpression of TcVps15-HA and TcVps15-K219D-HA also leads to increased accumulation of monodansylcadaverine (MDC) in autophagic vacuoles under nutritional stress conditions compared to wild-type cells. In addition, the MDC-specific activity shows to be significantly higher in TcVps15-HA overexpressing cells when compared with TcVps15-K219D-HA. Our results reveal for the first time a role of TcVps15 as a key regulator of TcVps34 enzymatic activity and implicate the TcVps15-Vps34 complex in autophagy in T. cruzi, exposing a new key pathway to explore novel chemotherapeutic targets. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

Pyroclastic Eruption Boosts Organic Carbon Fluxes Into Patagonian Fjords

NASA Astrophysics Data System (ADS)

Mohr, Christian H.; Korup, Oliver; Ulloa, Héctor; Iroumé, Andrés.

2017-11-01

Fjords and old-growth forests store large amounts of organic carbon. Yet the role of episodic disturbances, particularly volcanic eruptions, in mobilizing organic carbon in fjord landscapes covered by temperate rainforests remains poorly quantified. To this end, we estimated how much wood and soils were flushed to nearby fjords following the 2008 eruption of Chaitén volcano in south-central Chile, where pyroclastic sediments covered >12 km2 of pristine temperate rainforest. Field-based surveys of forest biomass, soil organic content, and dead wood transport reveal that the reworking of pyroclastic sediments delivered 66,500 + 14,600/-14,500 tC of large wood to two rivers entering the nearby Patagonian fjords in less than a decade. A similar volume of wood remains in dead tree stands and buried beneath pyroclastic deposits ( 79,900 + 21,100/-16,900 tC) or stored in active river channels (5,900-10,600 tC). We estimate that bank erosion mobilized 132,300+21,700/-30,600 tC of floodplain forest soil. Eroded and reworked forest soils have been accreting on coastal river deltas at >5 mm yr-1 since the eruption. While much of the large wood is transported out of the fjord by long-shore drift, the finer fraction from eroded forest soils is likely to be buried in the fjords. We conclude that the organic carbon fluxes boosted by rivers adjusting to high pyroclastic sediment loads may remain elevated for up to a decade and that Patagonian temperate rainforests disturbed by excessive loads of pyroclastic debris can be episodic short-lived carbon sources.

Deforestation in Amazonia impacts riverine carbon dynamics

NASA Astrophysics Data System (ADS)

Langerwisch, Fanny; Walz, Ariane; Rammig, Anja; Tietjen, Britta; Thonicke, Kirsten; Cramer, Wolfgang

2016-12-01

Fluxes of organic and inorganic carbon within the Amazon basin are considerably controlled by annual flooding, which triggers the export of terrigenous organic material to the river and ultimately to the Atlantic Ocean. The amount of carbon imported to the river and the further conversion, transport and export of it depend on temperature, atmospheric CO2, terrestrial productivity and carbon storage, as well as discharge. Both terrestrial productivity and discharge are influenced by climate and land use change. The coupled LPJmL and RivCM model system (Langerwisch et al., 2016) has been applied to assess the combined impacts of climate and land use change on the Amazon riverine carbon dynamics. Vegetation dynamics (in LPJmL) as well as export and conversion of terrigenous carbon to and within the river (RivCM) are included. The model system has been applied for the years 1901 to 2099 under two deforestation scenarios and with climate forcing of three SRES emission scenarios, each for five climate models. We find that high deforestation (business-as-usual scenario) will strongly decrease (locally by up to 90 %) riverine particulate and dissolved organic carbon amount until the end of the current century. At the same time, increase in discharge leaves net carbon transport during the first decades of the century roughly unchanged only if a sufficient area is still forested. After 2050 the amount of transported carbon will decrease drastically. In contrast to that, increased temperature and atmospheric CO2 concentration determine the amount of riverine inorganic carbon stored in the Amazon basin. Higher atmospheric CO2 concentrations increase riverine inorganic carbon amount by up to 20 % (SRES A2). The changes in riverine carbon fluxes have direct effects on carbon export, either to the atmosphere via outgassing or to the Atlantic Ocean via discharge. The outgassed carbon will increase slightly in the Amazon basin, but can be regionally reduced by up to 60 % due to

Deforestation in Amazonia impacts riverine carbon dynamics

NASA Astrophysics Data System (ADS)

Langerwisch, F.; Walz, A.; Rammig, A.; Tietjen, B.; Thonicke, K.; Cramer, W.

2015-10-01

Fluxes of organic and inorganic carbon within the Amazon basin are considerably controlled by annual flooding, which triggers the export of terrigenous organic material to the river and ultimately to the Atlantic Ocean. The amount of carbon imported to the river and the further conversion, transport and export of it, depend on terrestrial productivity and discharge, as well as temperature and atmospheric CO2. Both terrestrial productivity and discharge are influenced by climate and land use change. To assess the impact of these changes on the riverine carbon dynamics, the coupled model system of LPJmL and RivCM (Langerwisch et al., 2015) has been used. Vegetation dynamics (in LPJmL) as well as export and conversion of terrigenous carbon to and within the river (RivCM) are included. The model system has been applied for the years 1901 to 2099 under two deforestation scenarios and with climate forcing of three SRES emission scenarios, each for five climate models. The results suggest that, following deforestation, riverine particulate and dissolved organic carbon will strongly decrease by up to 90 % until the end of the current century. In parallel, discharge increases, leading to roughly unchanged net carbon transport during the first decades of the century, as long as a sufficient area is still forested. During the following decades the amount of transported carbon will decrease drastically. In contrast to the riverine organic carbon, the amount of riverine inorganic carbon is only determined by climate change forcing, namely increased temperature and atmospheric CO2 concentration. Mainly due to the higher atmospheric CO2 it leads to an increase in riverine inorganic carbon by up to 20 % (SRES A2). The changes in riverine carbon fluxes have direct effects on the export of carbon, either to the atmosphere via outgassing, or to the Atlantic Ocean via discharge. Basin-wide the outgassed carbon will increase slightly, but can be regionally reduced by up to 60 % due to

In Vitro-Generated Tc17 Cells Present a Memory Phenotype and Serve As a Reservoir of Tc1 Cells In Vivo

PubMed Central

Flores-Santibáñez, Felipe; Cuadra, Bárbara; Fernández, Dominique; Rosemblatt, Mariana V.; Núñez, Sarah; Cruz, Pablo; Gálvez-Cancino, Felipe; Cárdenas, J. César; Lladser, Alvaro; Rosemblatt, Mario; Bono, María Rosa; Sauma, Daniela

2018-01-01

Memory CD8+ T cells are ideal candidates for cancer immunotherapy because they can mediate long-term protection against tumors. However, the therapeutic potential of different in vitro-generated CD8+ T cell effector subsets to persist and become memory cells has not been fully characterized. Type 1 CD8+ T (Tc1) cells produce interferon-γ and are endowed with high cytotoxic capacity, whereas IL-17-producing CD8+ T (Tc17) cells are less cytotoxic but display enhanced self-renewal capacity. We sought to evaluate the functional properties of in vitro-generated Tc17 cells and elucidate their potential to become long lasting memory cells. Our results show that in vitro-generated Tc17 cells display a greater in vivo persistence and expansion in response to secondary antigen stimulation compared to Tc1 cells. When transferred into recipient mice, Tc17 cells persist in secondary lymphoid organs, present a recirculation behavior consistent with central memory T cells, and can shift to a Tc1 phenotype. Accordingly, Tc17 cells are endowed with a higher mitochondrial spare respiratory capacity than Tc1 cells and express higher levels of memory-related molecules than Tc1 cells. Together, these results demonstrate that in vitro-generated Tc17 cells acquire a central memory program and provide a lasting reservoir of Tc1 cells in vivo, thus supporting the use of Tc17 lymphocytes in the design of novel and more effective therapies. PMID:29472932

Radiocarbon dating of dissolved inorganic carbon in groundwater from confined parts of the Upper Floridan aquifer, Florida, USA

USGS Publications Warehouse

Plummer, Niel; Sprinkle, C.L.

2001-01-01

Geochemical reaction models were evaluated to improve radiocarbon dating of dissolved inorganic carbon (DIC) in groundwater from confined parts of the Upper Floridan aquifer in central and northeastern Florida, USA. The predominant geochemical reactions affecting the 14C activity of DIC include (1) dissolution of dolomite and anhydrite with calcite precipitation (dedolomitization), (2) sulfate reduction accompanying microbial degradation of organic carbon, (3) recrystallization of calcite (isotopic exchange), and (4) mixing of fresh water with as much as 7% saline water in some coastal areas. The calculated cumulative net mineral transfers are negligibly small in upgradient parts of the aquifer and increase significantly in downgradient parts of the aquifer, reflecting, at least in part, upward leakage from the Lower Floridan aquifer and circulation that contacted middle confining units in the Floridan aquifer system. The adjusted radiocarbon ages are independent of flow path and represent travel times of water from the recharge area to the sample point in the aquifer. Downgradient from Polk City (adjusted age 1.7 ka) and Keystone Heights (adjusted age 0.4 ka), 14 of the 22 waters have adjusted 14C ages of 20-30 ka, indicating that most of the fresh-water resource in the Upper Floridan aquifer today was recharged during the last glacial period. All of the paleowaters are enriched in 18O and 2H relative to modern infiltration, with maximum enrichment in ??18O of approximately 2.0%o.

Mineral-Enhanced Polyacrylic Acid Hydrogel as an Oyster-Inspired Organic-Inorganic Hybrid Adhesive.

PubMed

Li, Ang; Jia, Yunfei; Sun, Shengtong; Xu, Yisheng; Minsky, Burcu Baykal; Stuart, M A Cohen; Cölfen, Helmut; von Klitzing, Regine; Guo, Xuhong

2018-03-28

Underwater adhesion is crucial to many marine life forms living a sedentary lifestyle. Amongst them, mussel adhesion has been mostly studied, which inspires numerous investigations of 3,4-dihydroxyphenylalanine (DOPA)-based organic adhesives. In contrast, reef-building oysters represent another important "inorganic" strategy of marine molluscs for adhesion by generating biomineralized organic-inorganic adhesives, which is still rarely studied and no synthetic analogues have ever been reported so far. Here, a novel type of oyster-inspired organic-inorganic adhesive based on a biomineralized polyelectrolyte hydrogel is reported, which consists of polyacrylic acid physically cross-linked by very small amorphous calcium carbonate nanoparticles (<3 nm). The mineral-enhanced polyelectrolyte hydrogel adhesive is shown to be injectable, reusable, and optically clear upon curing in air. Moreover, comparable adhesion performance to DOPA-based adhesives is found for the hydrogel adhesive in both dry and wet conditions, which can even be further enhanced by introducing a small amount of second large cross-linker such as negatively charged nanoparticles. The present mineral hydrogel represents a new type of bio-inspired organic-inorganic adhesive that may find a variety of potential applications in adhesive chemistry.

Liquid-liquid phase separation in particles containing secondary organic material free of inorganic salts

NASA Astrophysics Data System (ADS)

Song, Mijung; Liu, Pengfei; Martin, Scot T.; Bertram, Allan K.

2017-09-01

Particles containing secondary organic material (SOM) are ubiquitous in the atmosphere and play a role in climate and air quality. Recently, research has shown that liquid-liquid phase separation (LLPS) occurs at high relative humidity (RH) (greater than ˜ 95 %) in α-pinene-derived SOM particles free of inorganic salts, while LLPS does not occur in isoprene-derived SOM particles free of inorganic salts. We expand on these findings by investigating LLPS at 290 ± 1 K in SOM particles free of inorganic salts produced from ozonolysis of β-caryophyllene, ozonolysis of limonene, and photo-oxidation of toluene. LLPS was observed at greater than ˜ 95 % RH in the biogenic SOM particles derived from β-caryophyllene and limonene while LLPS was not observed in the anthropogenic SOM particles derived from toluene. This work combined with the earlier work on LLPS in SOM particles free of inorganic salts suggests that the occurrence of LLPS in SOM particles free of inorganic salts is related to the oxygen-to-carbon elemental ratio (O : C) of the organic material. These results help explain the difference between the hygroscopic parameter κ of SOM particles measured above and below water saturation in the laboratory and field, and have implications for predicting the cloud condensation nucleation properties of SOM particles.

Vertical distributions of (99)Tc and the (99)Tc/(137)Cs activity ratio in the coastal water off Aomori, Japan.

PubMed

Nakanishi, Takahiro; Zheng, Jian; Aono, Tatsuo; Yamada, Masatoshi; Kusakabe, Masashi

2011-08-01

Using a sector-field ICP-MS the vertical distributions of the (99)Tc concentration and (99)Tc/(137)Cs activity ratio were measured in the coastal waters off Aomori Prefecture, Japan, where a spent-nuclear-fuel reprocessing plant has begun test operation. The (99)Tc concentrations in surface water ranged from 1.8 to 2.4 mBq/m(3), no greater than the estimated background level. Relatively high (99)Tc/(137)Cs activity ratios (10-12 × 10(-4)) would be caused by the inflow of the high-(99)Tc/(137)Cs water mass from the Japan Sea. There is no observable contamination from the reprocessing plant in the investigated area. The (99)Tc concentration and the (99)Tc/(137)Cs activity ratio in water column showed gradual decreases with depth. Our results implied that (99)Tc behaves in a more conservative manner than (137)Cs in marine environments. Copyright © 2011 Elsevier Ltd. All rights reserved.

Understanding on Soil Inorganic Carbon Transformation in North China

NASA Astrophysics Data System (ADS)

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

2015-04-01

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

Inhibition of precipitation of carbonate apatite by trisodium citrate analysed in base of the formation of chemical complexes in growth solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prywer, Jolanta, E-mail: jolanta.prywer@p.lodz.pl; Olszynski, Marcin; Mielniczek-Brzóska, Ewa

2015-11-15

Effect of trisodium citrate on the precipitation of carbonate apatite is studied. The experimental series are performed in the solution of artificial urine. The investigations are related to infectious urinary stones formation as carbonate apatite is one of the main components of this kind of stones. To mimic a real infection in urinary tract the aqueous ammonia solution was added to the solution of artificial urine. The spectrophotometric results demonstrate that trisodium citrate increases induction time with respect to carbonate apatite formation and decreases the efficiency of carbonate apatite precipitation. The inhibitory effect of trisodium citrate on the precipitation ofmore » carbonate apatite is explained in base of chemical speciation analysis. Such an analysis demonstrates that the inhibitory effect is mainly related with the fact that trisodium citrate binds Ca{sup 2+} ions and causes the formation of CaCit{sup −} and Ca{sub 10}(PO{sub 4}){sub 6}CO{sub 3} complexes. Trisodium citrate binds Ca{sup 2+} ions in the range of pH from 6 to 9.5 for which carbonate apatite is favored to be formed. - Highlights: • Trisodium citrate (TC) increases induction time of carbonate apatite (CA) formation. • TC decreases the efficiency of CA precipitation. • The inhibitory effect of TC is explained in base of chemical speciation analysis. • The inhibitory effect is mainly related with the fact that TC binds Ca{sup 2+} ions. • TC binds Ca{sup 2+} ions in the range of pH from 6 to 9.5 for which CA is formed.« less

Differential Activation of CD8+ Tumor-Specific Tc1 and Tc2 Cells by an IL-10-Producing Murine Plasmacytoma

PubMed Central

Pauels, Hans-Gerd; Becker, Christian; Kölsch, Eckehart

1998-01-01

The involvement of counteractive CD8+ T-cell subsets during tumor-specific immune responses was analyzed in a syngeneic murine plasmacytoma model. CD8+ Tc cells against the immunogenic IL-10-producing BALB/c plasmacytoma ADJ-PC-5 can be easily induced by immunization of BALB/c mice with X-irradiated ADJ-PC-5 tumor cells in vivo and in vitro. However, the failure of recipient mice to mount a protective Tc response against the tumor during early stages of a real or simulated tumor growth is not due to immunological ignorance, but depends on the induction of tumor-specific tolerance, involving a population of tumorinduced CD8+ T cells that are able to inhibit the generation of tumor-specific Tc cells in a primary ADJ-PC-5-specific MLTC, using IFN-γ as a suppressive factor. Whereas most longterm cultivated CD8+ ADJ-PC-5-specific Tc lines produce type-1 cytokines on stimulation, at least two of them, which were derived from a primary MLTC, display a type-2 cytokine spectrum. Furthermore, the primary in vitro Tc response against ADJ-PC-5 cells shows characteristics of a Tc2 response. The Tc response is strictly depending on tumor-derived IL-10. CD8+ Tc cells that are induced in a primary MLTC do not produce IFN-γ, and the tumor-specific Tc response is enhanced by IL-4 but suppressed by IFN-γ or IL-12. In contrast, ADJ-PC- 5-specific CD8+ Tc cells from immunized mice are IFN-γ producing Tc1 cells. Since the primary in vitro Tc response against the tumor is suppressed even by the smallest numbers of irradiated ADJ-PC-5-specific Tc1 cells via IFN-γ these Tc1 cells behave similar to the suppressive CD8+ T cells that are induced during early stages of ADJ-PC-5 tumorigenesis. PMID:9814607

Evolution of chemical and isotopic composition of inorganic carbon in a complex semi-arid zone environment: Consequences for groundwater dating using radiocarbon

NASA Astrophysics Data System (ADS)

Meredith, K. T.; Han, L. F.; Hollins, S. E.; Cendón, D. I.; Jacobsen, G. E.; Baker, A.

2016-09-01

Estimating groundwater age is important for any groundwater resource assessment and radiocarbon (14C) dating of dissolved inorganic carbon (DIC) can provide this information. In semi-arid zone (i.e. water-limited environments), there are a multitude of reasons why 14C dating of groundwater and traditional correction models may not be directly transferable. Some include; (1) the complex hydrological responses of these systems that lead to a mixture of different ages in the aquifer(s), (2) the varied sources, origins and ages of organic matter in the unsaturated zone and (3) high evaporation rates. These all influence the evolution of DIC and are not easily accounted for in traditional correction models. In this study, we determined carbon isotope data for; DIC in water, carbonate minerals in the sediments, sediment organic matter, soil gas CO2 from the unsaturated zone, and vegetation samples. The samples were collected after an extended drought, and again after a flood event, to capture the evolution of DIC after varying hydrological regimes. A graphical method (Han et al., 2012) was applied for interpretation of the carbon geochemical and isotopic data. Simple forward mass-balance modelling was carried out on key geochemical processes involving carbon and agreed well with observed data. High values of DIC and δ13CDIC, and low 14CDIC could not be explained by a simple carbonate mineral-CO2 gas dissolution process. Instead it is suggested that during extended drought, water-sediment interaction leads to ion exchange processes within the top ∼10-20 m of the aquifer which promotes greater calcite dissolution in saline groundwater. This process was found to contribute more than half of the DIC, which is from a mostly 'dead' carbon source. DIC is also influenced by carbon exchange between DIC in water and carbonate minerals found in the top 2 m of the unsaturated zone. This process occurs because of repeated dissolution/precipitation of carbonate that is dependent on

Inorganic Polymers.

DTIC Science & Technology

1987-07-16

inorganic plastics since the siloxanes . They have great potential and may in time prove to be even more useful than the polysiloxanes since many of these...important new class of seni-inorganic plastics since the siloxanes . They have great potential and may in time prove to be even more useful than the... biomedical qualities and useful engineering material parameters, toxicological, corrosion and fire resistance characteristics place many of the

Response of dissolved inorganic carbon (DIC) and δ13CDIC to changes in climate and land cover in SW China karst catchments

NASA Astrophysics Data System (ADS)

Zhao, Min; Liu, Zaihua; Li, Hong-Chun; Zeng, Cheng; Yang, Rui; Chen, Bo; Yan, Hao

2015-09-01

Monthly hydrochemical data and δ13C of dissolved inorganic carbon (DIC) in karst water samples from September 2007 to October 2012 were obtained to reveal the controlling mechanisms on DIC geochemistry and δ13CDIC under different conditions of climate and land cover in three karst catchments: Banzhai, Dengzhanhe and Chenqi, in Guizhou Province, SW China. DIC of karst water at the Banzhai site comes mainly from carbonate dissolution under open system conditions with soil CO2 produced by root respiration and organic carbon decomposition with lowest δ13C values under its dense virgin forest coverage. Weaker carbonate bedrock dissolution due to sparse and thin soil cover results in lower δ13CDIC, pCO2, DIC and EC, and lower cation and anion concentrations. At the Chenqi site, larger soil CO2 input from a thick layer of soil results in high pCO2 and DIC, and low pH, SIc and δ13CDIC in the karst water. At the Dengzhanhe site, a lesser soil CO2 input due to stronger karst rock desertification and strong gypsum dissolution contribute to higher δ13CDIC, high EC and high cation and anion concentrations. Soil CO2 inputs, controlled by biological activity and available soil moisture, carbonate bedrock dissolution, dilution and degassing effects, vary seasonally following rainfall and temperature changes. Consequently, there are seasonal cycles in hydrochemistry and δ13CDIC of the karst water, with high pCO2 and low pH, EC, SIc, and δ13CDIC values in the warm and rainy seasons, and vice versa during the cold and dry seasons. A strongly positive shift (>3‰) in δ13CDIC occurred in the drought year, 2011, indicating that δ13CDIC in groundwater systems can be an effective indicator of environmental and/or climate changes.

Microstructure and Properties of Zircon-Added Carbon Refractories for Blast Furnace

NASA Astrophysics Data System (ADS)

Zhu, Tianbin; Li, Yawei; Sang, Shaobai; Chen, Xilai; Zhao, Lei; Li, Yuanbing; Li, Shujing

2012-11-01

Microstructure and properties of zircon-added carbon refractory specimens for blast furnace (BF) were investigated with the aid of X-ray diffraction (XRD), a scanning electron microscope (SEM), energy-dispersive X-ray, mercury porosimetry, and a laser thermal conductivity (TC) meter. Additives could influence the matrix structures and improve the properties of specimens. With the increase of zircon powder content, the amount of SiC whiskers formed increased and their aspect ratio became larger, and the SiC whiskers tended to be distributed homogeneously. Zircon powder additions decreased the mean pore diameter and increased <1- μm pore volume by filling in pores via SiC, improved the TC and the cold crushing strength (CCS) due to the in-situ formation of the more well-developed SiC whiskers with high TC, and significantly reduced the molten iron attack to carbon specimens.

Impact of seawater carbonate chemistry on the calcification of marine bivalves

NASA Astrophysics Data System (ADS)

Thomsen, J.; Haynert, K.; Wegner, K. M.; Melzner, F.

2015-07-01

Bivalve calcification, particularly of the early larval stages, is highly sensitive to the change in ocean carbonate chemistry resulting from atmospheric CO2 uptake. Earlier studies suggested that declining seawater [CO32-] and thereby lowered carbonate saturation affect shell production. However, disturbances of physiological processes such as acid-base regulation by adverse seawater pCO2 and pH can affect calcification in a secondary fashion. In order to determine the exact carbonate system component by which growth and calcification are affected it is necessary to utilize more complex carbonate chemistry manipulations. As single factors, pCO2 had no effects and [HCO3-] and pH had only limited effects on shell growth, while lowered [CO32-] strongly impacted calcification. Dissolved inorganic carbon (CT) limiting conditions led to strong reductions in calcification, despite high [CO32-], indicating that [HCO3-] rather than [CO32-] is the inorganic carbon source utilized for calcification by mytilid mussels. However, as the ratio [HCO3-] / [H+] is linearly correlated with [CO32-] it is not possible to differentiate between these under natural seawater conditions. An equivalent of about 80 μmol kg-1 [CO32-] is required to saturate inorganic carbon supply for calcification in bivalves. Below this threshold biomineralization rates rapidly decline. A comparison of literature data available for larvae and juvenile mussels and oysters originating from habitats differing substantially with respect to prevailing carbonate chemistry conditions revealed similar response curves. This suggests that the mechanisms which determine sensitivity of calcification in this group are highly conserved. The higher sensitivity of larval calcification seems to primarily result from the much higher relative calcification rates in early life stages. In order to reveal and understand the mechanisms that limit or facilitate adaptation to future ocean acidification, it is necessary to better

Impact of seawater carbonate chemistry on the calcification of marine bivalves

NASA Astrophysics Data System (ADS)

Thomsen, J.; Haynert, K.; Wegner, K. M.; Melzner, F.

2015-01-01

Bivalve calcification, particular of the early larval stages is highly sensitive to the change of ocean carbonate chemistry resulting from atmospheric CO2 uptake. Earlier studies suggested that declining seawater [CO32-] and thereby lowered carbonate saturation affect shell production. However, disturbances of physiological processes such as acid-base regulation by adverse seawater pCO2 and pH can affect calcification in a secondary fashion. In order to determine the exact carbonate system component by which growth and calcification are affected it is necessary to utilize more complex carbonate chemistry manipulations. As single factors, pCO2 had no and [HCO3-] and pH only limited effects on shell growth, while lowered [CO32-] strongly impacted calcification. Dissolved inorganic carbon (CT) limiting conditions led to strong reductions in calcification, despite high [CO32-], indicating that [HCO3-] rather than [CO32-] is the inorganic carbon source utilized for calcification by mytilid mussels. However, as the ratio [HCO3-] / [H+] is linearly correlated with [CO32-] it is not possible to differentiate between these under natural seawater conditions. Therefore, the availability of [HCO3-] combined with favorable environmental pH determines calcification rate and an equivalent of about 80 μmol kg-1 [CO32-] is required to saturate inorganic carbon supply for calcification in bivalves. Below this threshold biomineralization rates rapidly decline. A comparison of literature data available for larvae and juvenile mussels and oysters originating from habitats differing substantially with respect to prevailing carbonate chemistry conditions revealed similar response curves. This suggests that the mechanisms which determine sensitivity of calcification in this group are highly conserved. The higher sensitivity of larval calcification seems to primarily result from the much higher relative calcification rates in early life stages. In order to reveal and understand the

Carbon sequestration potential for forage and pasture systems

USDA-ARS?s Scientific Manuscript database

Grassland soils represent a large reservoir of organic and inorganic carbon. Regionally, grasslands are annual CO2 sources or sinks depending on crop and soil management, current soil organic carbon (SOC) concentration and climate. Land management changes (LMC) impact SOC sequestration rate, the du...

The quest for inorganic fullerenes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pietsch, Susanne; Dollinger, Andreas; Strobel, Christoph H.

2015-10-02

Experimental results of the search for inorganic fullerenes are presented. Mo nS m - and W nS m - clusters are generated with a pulsed arc cluster ion source equipped with an annealing stage. This is known to enhance fullerene formation in the case of carbon. Analogous to carbon, the mass spectra of the metal chalcogenide clusters produced in this way exhibit a bimodal structure. Moreover, the species in the first maximum at low mass are known to be platelets. The structure of the species in the second maximum is studied by anion photoelectron spectroscopy, scanning transmission electron microscopy,more » and scanning tunneling microcopy. All experimental results indicate a two-dimensional structure of these species and disagree with a three-dimensional fullerene-like geometry. A possible explanation for this preference of two-dimensional structures is the ability of a two-element material to saturate the dangling bonds at the edges of a platelet by excess atoms of one element. A platelet consisting of a single element only cannot do this. Likewise, graphite and boron might be the only materials forming nano-spheres because they are the only single element materials assuming two-dimensional structures.« less

The quest for inorganic fullerenes

NASA Astrophysics Data System (ADS)

Pietsch, Susanne; Dollinger, Andreas; Strobel, Christoph H.; Park, Eun Ji; Ganteför, Gerd; Seo, Hyun Ook; Kim, Young Dok; Idrobo, Juan-Carlos; Pennycook, Stephen J.

2015-10-01

Experimental results of the search for inorganic fullerenes are presented. MonSm- and WnSm- clusters are generated with a pulsed arc cluster ion source equipped with an annealing stage. This is known to enhance fullerene formation in the case of carbon. Analogous to carbon, the mass spectra of the metal chalcogenide clusters produced in this way exhibit a bimodal structure. The species in the first maximum at low mass are known to be platelets. Here, the structure of the species in the second maximum is studied by anion photoelectron spectroscopy, scanning transmission electron microscopy, and scanning tunneling microcopy. All experimental results indicate a two-dimensional structure of these species and disagree with a three-dimensional fullerene-like geometry. A possible explanation for this preference of two-dimensional structures is the ability of a two-element material to saturate the dangling bonds at the edges of a platelet by excess atoms of one element. A platelet consisting of a single element only cannot do this. Accordingly, graphite and boron might be the only materials forming nano-spheres because they are the only single element materials assuming two-dimensional structures.

A Study of metabolic transformation of organic and inorganic components in PM2.5 and PM10, South Korea

NASA Astrophysics Data System (ADS)

Kim, J.; Yoon, H.; Lee, M.

2012-12-01

The important factors of atmospheric particle matter (PM) are size, concentration, composition and toxicity which can considerably affect the possible human health problem, especially respiratory diseases, visibility reduction and climate change. PM2.5 and PM10 are complex mixture of ammonium sulfate, ammonium nitrate, organic carbon, inorganic carbon and inorganic constituents. Recently, most researches of source attribution and assessments of the relationship between health effects and particle concentrations have not taken advantage of the development in analytical tools measuring the detailed molecular structure and microstructure of particles and of the knowledge of particle formation mechanisms in combustion system. This study will combine variety analytical techniques that can provide structural and compositional information to determine the correlation between sources of hazardous material and physicochemical properties in aerosol particle. Inorganic metal can be rapidly quantifying to filter base using ED-XRF (Energy-dispersive X-ray fluorescence). Speciation and quantification of water soluble components applied HPLC-ICP-MS and LC-MS NMR (nuclear magnetic resonance). Afterward, we investigate metabolic transformations of atmospheric particle matter also using FE-TEM (Field Emission Transmission Electron Microscopy).

Thermal responses of Symbiodinium photosynthetic carbon assimilation

NASA Astrophysics Data System (ADS)

Oakley, Clinton A.; Schmidt, Gregory W.; Hopkinson, Brian M.

2014-06-01

The symbiosis between hermatypic corals and their dinoflagellate endosymbionts, genus Symbiodinium, is based on carbon exchange. This symbiosis is disrupted by thermally induced coral bleaching, a stress response in which the coral host expels its algal symbionts as they become physiologically impaired. The disruption of the dissolved inorganic carbon (DIC) supply or the thermal inactivation of Rubisco have been proposed as sites of initial thermal damage that leads to the bleaching response. Symbiodinium possesses a highly unusual Form II ribulose bisphosphate carboxylase/oxygenase (Rubisco), which exhibits a lower CO2:O2 specificity and may be more thermally unstable than the Form I Rubiscos of other algae and land plants. Components of the CO2 concentrating mechanism (CCM), which supplies inorganic carbon for photosynthesis, may also be temperature sensitive. Here, we examine the ability of four cultured Symbiodinium strains to acquire and fix DIC across a temperature gradient. Surprisingly, the half-saturation constant of photosynthesis with respect to DIC concentration ( K P), an index of CCM function, declined with increasing temperature in three of the four strains, indicating a greater potential for photosynthetic carbon acquisition at elevated temperatures. In the fourth strain, there was no effect of temperature on K P. Finding no evidence for thermal inhibition of the CCM, we conclude that CCM components are not likely to be the primary sites of thermal damage. Reduced photosynthetic quantum yields, a hallmark of thermal bleaching, were observed at low DIC concentrations, leaving open the possibility that reduced inorganic carbon availability is involved in bleaching.

Inorganic nanotubes and fullerene-like nanoparticles.

PubMed

Tenne, R

2006-11-01

Although graphite, with its anisotropic two-dimensional lattice, is the stable form of carbon under ambient conditions, on nanometre length scales it forms zero- and one-dimensional structures, namely fullerenes and nanotubes, respectively. This virtue is not limited to carbon and, in recent years, fullerene-like structures and nanotubes have been made from numerous compounds with layered two-dimensional structures. Furthermore, crystalline and polycrystalline nanotubes of pure elements and compounds with quasi-isotropic (three-dimensional) unit cells have also been synthesized, usually by making use of solid templates. These findings open up vast opportunities for the synthesis and study of new kinds of nanostructures with properties that may differ significantly from the corresponding bulk materials. Various potential applications have been proposed for the inorganic nanotubes and the fullerene-like phases. Fullerene-like nanoparticles have been shown to exhibit excellent solid lubrication behaviour, suggesting many applications in, for example, the automotive and aerospace industries, home appliances, and recently for medical technology. Various other potential applications, in catalysis, rechargeable batteries, drug delivery, solar cells and electronics have also been proposed.

Inorganic nanotubes and fullerene-like nanoparticles

NASA Astrophysics Data System (ADS)

Tenne, R.

2006-11-01

Although graphite, with its anisotropic two-dimensional lattice, is the stable form of carbon under ambient conditions, on nanometre length scales it forms zero- and one-dimensional structures, namely fullerenes and nanotubes, respectively. This virtue is not limited to carbon and, in recent years, fullerene-like structures and nanotubes have been made from numerous compounds with layered two-dimensional structures. Furthermore, crystalline and polycrystalline nanotubes of pure elements and compounds with quasi-isotropic (three-dimensional) unit cells have also been synthesized, usually by making use of solid templates. These findings open up vast opportunities for the synthesis and study of new kinds of nanostructures with properties that may differ significantly from the corresponding bulk materials. Various potential applications have been proposed for the inorganic nanotubes and the fullerene-like phases. Fullerene-like nanoparticles have been shown to exhibit excellent solid lubrication behaviour, suggesting many applications in, for example, the automotive and aerospace industries, home appliances, and recently for medical technology. Various other potential applications, in catalysis, rechargeable batteries, drug delivery, solar cells and electronics have also been proposed.

Amorphous Calcium Carbonate Based-Microparticles for Peptide Pulmonary Delivery.

PubMed

Tewes, Frederic; Gobbo, Oliviero L; Ehrhardt, Carsten; Healy, Anne Marie

2016-01-20

Amorphous calcium carbonate (ACC) is known to interact with proteins, for example, in biogenic ACC, to form stable amorphous phases. The control of amorphous/crystalline and inorganic/organic ratios in inhalable calcium carbonate microparticles may enable particle properties to be adapted to suit the requirements of dry powders for pulmonary delivery by oral inhalation. For example, an amorphous phase can immobilize and stabilize polypeptides in their native structure and amorphous and crystalline phases have different mechanical properties. Therefore, inhalable composite microparticles made of inorganic (i.e., calcium carbonate and calcium formate) and organic (i.e., hyaluronan (HA)) amorphous and crystalline phases were investigated for peptide and protein pulmonary aerosol delivery. The crystalline/amorphous ratio and polymorphic form of the inorganic component was altered by changing the microparticle drying rate and by changing the ammonium carbonate and HA initial concentration. The bioactivity of the model peptide, salmon calcitonin (sCT), coprocessed with alpha-1-antitrypsin (AAT), a model protein with peptidase inhibitor activity, was maintained during processing and the microparticles had excellent aerodynamic properties, making them suitable for pulmonary aerosol delivery. The bioavailability of sCT after aerosol delivery as sCT and AAT-loaded composite microparticles to rats was 4-times higher than that of sCT solution.

Force-controlled inorganic crystallization lithography.

PubMed

Cheng, Chao-Min; LeDuc, Philip R

2006-09-20

Lithography plays a key role in integrated circuits, optics, information technology, biomedical applications, catalysis, and separation technologies. However, inorganic lithography techniques remain of limited utility for applications outside of the typical foci of integrated circuit manufacturing. In this communication, we have developed a novel stamping method that applies pressure on the upper surface of the stamp to regulate the dewetting process of the inorganic buffer and the evaporation rate of the solvent in this buffer between the substrate and the surface of the stamp. We focused on generating inorganic microstructures with specific locations and also on enabling the ability to pattern gradients during the crystallization of the inorganic salts. This approach utilized a combination of lithography with bottom-up growth and assembly of inorganic crystals. This work has potential applications in a variety of fields, including studying inorganic material patterning and small-scale fabrication technology.

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

USGS Publications Warehouse

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.

Tc-99m tilmanocept versus Tc-99m sulfur colloid in breast cancer sentinel lymph node identification: Results from a randomized, blinded clinical trial.

PubMed

Unkart, Jonathan T; Hosseini, Ava; Wallace, Anne M

2017-12-01

No prior trials have compared sentinel lymph node (SLN) identification outcomes between Tc-99m tilmanocept (TcTM) and Tc-99m sulfur colloid (TcSC) in breast cancer (BC). We report on the secondary outcomes from a randomized, double-blinded, single surgeon clinical trial comparing post-injection site pain between TcTM and TcSC. Patients were randomized to receive a preoperative single, peritumoral intradermal injection of TcTM or TcSC. The number of total, "hot", and blue nodes detected and removed were compared between groups. Fifty-two (27-TcSC and 25-TcTM) patients were enrolled and underwent definitive surgical treatment. At least one "hot" SLN was detected in all patients. Three (5.8%) patients had a disease positive-SLN. The total number of SLNs removed was 61 (mean 2.26 (standard deviation (SD) 0.90)) in the TcSC group and 54 (mean 2.16 (SD 0.90)) in the TcTM group, P = 0.69. The total number of "hot" nodes in the TcSC group was 1.96 (SD 0.76) compared to 2.04 (SD 0.73) in the TcTM group, P = 0.71. The number of identified SLNs did not differ significantly between TcTM and TcSC. Given that no significant technical advantages exist between the two agents, surgeons should choose a radiopharmaceutical based on cost and side effect profile. © 2017 Wiley Periodicals, Inc.

Rheological and tribological properties of carbon nanotube/thermoplastic nanocomposites incorporating inorganic fullerene-like WS2 nanoparticles.

PubMed

Díez-Pascual, Ana M; Naffakh, Mohammed; Marco, Carlos; Ellis, Gary

2012-07-12

The rheological and tribological properties of single-walled carbon nanotube (SWCNT)-reinforced poly(phenylene sulphide) (PPS) and poly(ether ether ketone) (PEEK) nanocomposites prepared via melt-extrusion were investigated. The effectiveness of employing a dual-nanofiller strategy combining polyetherimide (PEI)-wrapped SWCNTs with inorganic fullerene-like tungsten disulfide (IF-WS2) nanoparticles for property enhancement of the resulting hybrid composites was evaluated. Viscoelastic measurements revealed that the complex viscosity η, storage modulus G', and loss modulus G″ increased with SWCNT content. In the low-frequency region, G' and G″ became almost independent of frequency at higher SWCNT loadings, suggesting a transition from liquid-like to solid-like behavior. The incorporation of increasing IF-WS2 contents led to a progressive drop in η and G' due to a lubricant effect. PEEK nanocomposites showed lower percolation threshold than those based on PPS, ascribed to an improved SWCNT dispersion due to the higher affinity between PEI and PEEK. The SWCNTs significantly lowered the wear rate but only slightly reduced the coefficient of friction. Composites with both nanofillers exhibited improved wear behavior, attributed to the outstanding tribological properties of these nanoparticles and a synergistic reinforcement effect. The combination of SWCNTs with IF-WS2 is a promising route for improving the tribological and rheological performance of thermoplastic nanocomposites.

Biogenic Calcium Carbonate with Hierarchical Organic-Inorganic Composite Structure Enhancing the Removal of Pb(II) from Wastewater.

PubMed

Zhou, Xueli; Liu, Weizhen; Zhang, Jian; Wu, Can; Ou, Xinwen; Tian, Chen; Lin, Zhang; Dang, Zhi

2017-10-18

Calcium carbonate from geological sources (geo-CaCO 3 , e.g., calcite, aragonite) is used extensively in removing heavy metals from wastewater through replacement reaction. However, geo-CaCO 3 has an intrinsically compact crystalline structure that results in low efficiency in pollutant removal and thus its use may produce enormous sludge. In this work, biogenic calcium carbonate (bio-CaCO 3 ) derived from oyster shells was used to remove Pb(II) from wastewater and found to significantly outperform geo-CaCO 3 (calcite). The thermodynamics study revealed that the maximum adsorption capacity of bio-CaCO 3 for Pb(II) was three times that of geo-CaCO 3 , reaching up to 1667 mg/g. The kinetics study disclosed that the dissolution kinetics and the rate of intraparticle diffusion of bio-CaCO 3 were faster than those of geo-CaCO 3 . Extensive mechanism research through X-ray powder diffraction (XRD), scanning electron microscopy (SEM), N 2 adsorption/desorption test and mercury intrusion porosimetry showed that the hierarchical porous organic-inorganic hybrid structure of bio-CaCO 3 expedited the dissolution of CaCO 3 to provide abundant CO 3 2- active sites and facilitated the permeation and diffusion of Pb(II) into the bulk solid phases. In addition, Fourier transform infrared spectroscopy (FTIR) study, X-ray photoelectron spectroscopy (XPS) analysis, and the examination of Pb(II) removal ability of bio-CaCO 3 after calcination indicated that the organic functional groups of bio-CaCO 3 also facilitated the immobilization of Pb(II) into CaCO 3 particles, although the major contribution was from the hierarchical porous structure of bio-CaCO 3 .

Improving Defect-Based Quantum Emitters in Silicon Carbide via Inorganic Passivation.

PubMed

Polking, Mark J; Dibos, Alan M; de Leon, Nathalie P; Park, Hongkun

2018-01-01

Defect-based color centers in wide-bandgap crystalline solids are actively being explored for quantum information science, sensing, and imaging. Unfortunately, the luminescent properties of these emitters are frequently degraded by blinking and photobleaching that arise from poorly passivated host crystal surfaces. Here, a new method for stabilizing the photoluminescence and charge state of color centers based on epitaxial growth of an inorganic passivation layer is presented. Specifically, carbon antisite-vacancy pairs (CAV centers) in 4H-SiC, which serve as single-photon emitters at visible wavelengths, are used as a model system to demonstrate the power of this inorganic passivation scheme. Analysis of CAV centers with scanning confocal microscopy indicates a dramatic improvement in photostability and an enhancement in emission after growth of an epitaxial AlN passivation layer. Permanent, spatially selective control of the defect charge state can also be achieved by exploiting the mismatch in spontaneous polarization at the AlN/SiC interface. These results demonstrate that epitaxial inorganic passivation of defect-based quantum emitters provides a new method for enhancing photostability, emission, and charge state stability of these color centers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nanotubes from Inorganic Materials

NASA Astrophysics Data System (ADS)

Tenne, Reshef; Zettl, Alex K.

The inorganic analogs of carbon fullerenes and nanotubes, like MoS2 and BN, are reviewed. It is argued that nanoparticles of 2D layered compounds are inherently unstable in the planar configuration and prefer to form closed cage structures. The progress in the synthesis of these nanomaterials, and, in particular, the large-scale synthesis of BN, WS2 and V2O5 nanotubes, are described. Some of the electronic, optical and mechanical properties of these nanostructures are reviewed. The red-shift of the energy gap with shrinking nanotube diameter is discussed as well as the suggestion that zigzag nanotubes exhibit a direct gap rather than an indirect gap, as is prevalent in many of the bulk 2D materials. Some potential applications of these nanomaterials are presented as well, most importantly the superior tribological properties of WS2 and MoS2 nested fullerene-like structures (onions).

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

NASA Astrophysics Data System (ADS)

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

2016-02-01

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

Imaging experimental intraabdominal abscesses with 99mTc-PEG liposomes and 99mTc-HYNIC IgG.

PubMed Central

Dams, E T; Reijnen, M M; Oyen, W J; Boerman, O C; Laverman, P; Storm, G; van der Meer, J W; Corstens, F H; van Goor, H

1999-01-01

OBJECTIVE: To evaluate the accuracy of technetium-99m-labeled polyethylene glycol-coated liposomes (99mTc-PEG liposomes) and technetium-99m-labeled nonspecific human immunoglobulin G (99mTc-HYNIC IgG) for the scintigraphic detection of experimental intraabdominal abscesses in comparison with that of a standard agent, gallium-67 citrate. BACKGROUND: Scintigraphic imaging techniques can be very useful for the rapid and accurate localization of intraabdominal abscesses. Two newly developed radiolabeled agents, 99mTc-PEG liposomes and 99mTc-HYNIC IgG, have shown to be excellent agents for imaging experimental focal infection, but have not yet been studied in the detection of abdominal abscesses. METHODS: Intraabdominal abscesses were induced in 42 rats using the cecal ligation and puncture technique. Seven days later, randomized groups of rats received 99mTc-PEG liposomes, 99mTc-HYNIC IgG, or 67Ga citrate intravenously. The rats were imaged up to 24 hours after the injection. The biodistribution of the radiolabel was determined by counting dissected tissues ex vivo. Macroscopic intraabdominal abnormalities and focal uptake on the images were independently scored on a semiquantitative scale. RESULTS: 99mTc-PEG liposomes provided the earliest scintigraphic visualization of the abscess (as soon as 2 hours after the injection vs. 4 hours for the other two agents). Liposomes, IgG, and gallium all showed similarly high absolute uptake in the abscess. Focal uptake of liposomes and gallium correlated best with the extent of the macroscopic abnormalities. CONCLUSIONS: 99mTc-PEG liposomes and 99mTc-HYNIC IgG performed at least as well as the standard agent, 67Ga citrate, in the detection of experimental intraabdominal abscesses, with obvious advantages such as lower radiation exposure and more favorable physical properties. Of the two technetium agents, the liposomes seemed to be superior, providing the earliest diagnostic image and the best correlation with the inflammatory

Science Update: Inorganic Chemistry.

ERIC Educational Resources Information Center

Rawls, Rebecca

1981-01-01

Describes areas of inorganic chemistry which have changed dramatically in the past year or two, including photochemistry, electrochemistry, organometallic complexes, inorganic reaction theory, and solid state chemistry. (DS)

Biomineralization-inspired synthesis of functional organic/inorganic hybrid materials: organic molecular control of self-organization of hybrids.

PubMed

Arakaki, Atsushi; Shimizu, Katsuhiko; Oda, Mayumi; Sakamoto, Takeshi; Nishimura, Tatsuya; Kato, Takashi

2015-01-28

Organisms produce various organic/inorganic hybrid materials, which are called biominerals. They form through the self-organization of organic molecules and inorganic elements under ambient conditions. Biominerals often have highly organized and hierarchical structures from nanometer to macroscopic length scales, resulting in their remarkable physical and chemical properties that cannot be obtained by simple accumulation of their organic and inorganic constituents. These observations motivate us to create novel functional materials exhibiting properties superior to conventional materials--both synthetic and natural. Herein, we introduce recent progress in understanding biomineralization processes at the molecular level and the development of organic/inorganic hybrid materials by these processes. We specifically outline fundamental molecular studies on silica, iron oxide, and calcium carbonate biomineralization and describe material synthesis based on these mechanisms. These approaches allow us to design a variety of advanced hybrid materials with desired morphologies, sizes, compositions, and structures through environmentally friendly synthetic routes using functions of organic molecules.

The carbon bonus of organic nitrogen enhances nitrogen use efficiency of plants

DOE PAGES

Franklin, Oskar; Cambui, Camila Aguetoni; Gruffman, Linda; ...

2016-06-29

The importance of organic nitrogen (N) for plant nutrition and productivity is increasingly being recognized. Here we show that it is not only the availability in the soil that matters, but also the effects on plant growth. The chemical form of N taken up, whether inorganic (such as nitrate) or organic (such as amino acids), may significantly influence plant shoot and root growth, and nitrogen use efficiency (NUE). We analysed these effects by synthesizing results from multiple laboratory experiments on small seedlings (Arabidopsis, poplar, pine and spruce) based on a tractable plant growth model. A key point is that themore » carbon cost of assimilating organic N into proteins is lower than that of inorganic N, mainly because of its carbon content. This carbon bonus makes it more beneficial for plants to take up organic than inorganic N, even when its availability to the roots is much lower – up to 70% lower for Arabidopsis seedlings. At equal growth rate, root:shoot ratio was up to three times higher and nitrogen productivity up to 20% higher for organic than inorganic N, which both are factors that may contribute to higher NUE in crop production.« less

The carbon bonus of organic nitrogen enhances nitrogen use efficiency of plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Franklin, Oskar; Cambui, Camila Aguetoni; Gruffman, Linda

The importance of organic nitrogen (N) for plant nutrition and productivity is increasingly being recognized. Here we show that it is not only the availability in the soil that matters, but also the effects on plant growth. The chemical form of N taken up, whether inorganic (such as nitrate) or organic (such as amino acids), may significantly influence plant shoot and root growth, and nitrogen use efficiency (NUE). We analysed these effects by synthesizing results from multiple laboratory experiments on small seedlings (Arabidopsis, poplar, pine and spruce) based on a tractable plant growth model. A key point is that themore » carbon cost of assimilating organic N into proteins is lower than that of inorganic N, mainly because of its carbon content. This carbon bonus makes it more beneficial for plants to take up organic than inorganic N, even when its availability to the roots is much lower – up to 70% lower for Arabidopsis seedlings. At equal growth rate, root:shoot ratio was up to three times higher and nitrogen productivity up to 20% higher for organic than inorganic N, which both are factors that may contribute to higher NUE in crop production.« less

The carbon bonus of organic nitrogen enhances nitrogen use efficiency of plants

PubMed Central

Cambui, Camila Aguetoni; Gruffman, Linda; Palmroth, Sari; Oren, Ram; Näsholm, Torgny

2016-01-01

Abstract The importance of organic nitrogen (N) for plant nutrition and productivity is increasingly being recognized. Here we show that it is not only the availability in the soil that matters, but also the effects on plant growth. The chemical form of N taken up, whether inorganic (such as nitrate) or organic (such as amino acids), may significantly influence plant shoot and root growth, and nitrogen use efficiency (NUE). We analysed these effects by synthesizing results from multiple laboratory experiments on small seedlings (Arabidopsis, poplar, pine and spruce) based on a tractable plant growth model. A key point is that the carbon cost of assimilating organic N into proteins is lower than that of inorganic N, mainly because of its carbon content. This carbon bonus makes it more beneficial for plants to take up organic than inorganic N, even when its availability to the roots is much lower – up to 70% lower for Arabidopsis seedlings. At equal growth rate, root:shoot ratio was up to three times higher and nitrogen productivity up to 20% higher for organic than inorganic N, which both are factors that may contribute to higher NUE in crop production. PMID:27241731

Differential Lung Uptake of 99mTc-HMPAO and 99mTc-Duramycin in the Chronic Hyperoxia Rat Model

PubMed Central

Clough, Anne V.; Audi, Said H.; Haworth, Steven T.; Roerig, David L.

2015-01-01

Noninvasive radionuclide imaging has the potential to identify and assess mechanisms involved in particular stages of lung injury which occur with acute respiratory distress syndrome, for example. Lung uptake of 99mTc-hexamethylpropyleneamine oxime (HMPAO) is reported to be partially dependent on the redox status of the lung tissue while 99mTc-duramycin, a new marker of cell injury, senses cell death via apoptosis and/or necrosis. Thus, we investigated changes in lung uptake of these agents in rat exposed to hyperoxia for prolonged periods, a common model of acute lung injury. Methods Male Sprague-Dawley rats were pre-exposed to either normoxia (21% O2) or hyperoxia (85% O2) for up to 21 days. For imaging, the rats were anesthetized, injected i.v. with either 99mTc-HMPAO or 99mTc-duramycin (37-74 MBq) and planar images were acquired using a high sensitivity modular gamma camera. Subsequently, 99mTc-macroagreggated albumin (37 MBq, diam=10-40 μm) was injected i.v., imaged, and used to define a lung region-of-interest. The lung to background ratio was used as a measure of lung uptake. Results Hyperoxia exposure resulted in a 74% increase in 99mTc-HMPAO lung uptake, which peaked at 7 days and persisted for the 21 days of exposure. 99mTc-duramycin lung uptake was also maximal at 7 days of exposure but decreased to near control levels by 21 days. The sustained elevation of 99mTc-HMPAO uptake suggests ongoing changes in lung redox status whereas cell death appears to have subsided by 21 days. Conclusion These results suggest the potential use of 99mTc-HMPAO and 99mTc-duramycin as redox and cell-death imaging biomarkers, respectively, for in vivo identification and assessment of different stages of lung injury. PMID:23086010

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

PubMed

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

2008-03-01

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

Theoretical Modeling of 99 Tc NMR Chemical Shifts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hall, Gabriel B.; Andersen, Amity; Washton, Nancy M.

Technetium (Tc) displays a rich chemistry due to the wide range of oxidation states (from -I to +VII) and ability to form coordination compounds. Determination of Tc speciation in complex mixtures is a major challenge, and 99Tc NMR spec-troscopy is widely used to probe chemical environments of Tc in odd oxidation states. However interpretation of the 99Tc NMR data is hindered by the lack of reference compounds. DFT computations can help fill this gap, but to date few com-putational studies have focused on 99Tc NMR of compounds and complexes. This work systematically evaluates the inclu-sion small percentages of Hartree-Fock exchangemore » correlation and relativistic effects in DFT computations to support in-terpretation of the 99Tc NMR spectra. Hybrid functionals are found to perform better than their pure GGA counterparts, and non-relativistic calculations have been found to generally show a lower mean absolute deviation from experiment. Overall non-relativistic PBE0 and B3PW91 calculations are found to most accurately predict 99Tc NMR chemical shifts.« less

Biological-inorganic hybrid systems as a generalized platform for chemical production.

PubMed

Nangle, Shannon N; Sakimoto, Kelsey K; Silver, Pamela A; Nocera, Daniel G

2017-12-01

An expanding renewable energy market to supplant petrochemicals has motivated synthesis technologies that use renewable feedstocks, such as CO 2 . Hybrid biological-inorganic systems provide a sustainable, efficient, versatile, and inexpensive chemical synthesis platform. These systems comprise biocompatible electrodes that transduce electrical energy either directly or indirectly into bioavailable energy, such as H 2 and NAD(P)H. In combination, specific bacteria use these energetic reducing equivalents to fix CO 2 into multi-carbon organic compounds. As hybrid biological-inorganic technologies have developed, the focus has shifted from phenomenological and proof-of-concept discovery towards enhanced energy efficiency, production rate, product scope, and industrial robustness. In this review, we highlight the progress and the state-of-the-art of this field and describe the advantages and challenges involved in designing bio- and chemo- compatible systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Liquid–liquid phase separation in particles containing secondary organic material free of inorganic salts

DOE PAGES

Song, Mijung; Liu, Pengfei; Martin, Scot T.; ...

2017-09-25

Particles containing secondary organic material (SOM) are ubiquitous in the atmosphere and play a role in climate and air quality. Recently, research has shown that liquid–liquid phase separation (LLPS) occurs at high relative humidity (RH) (greater than ~95 %) in α-pinene-derived SOM particles free of inorganic salts, while LLPS does not occur in isoprene-derived SOM particles free of inorganic salts. We expand on these findings by investigating LLPS at 290 ± 1 K in SOM particles free of inorganic salts produced from ozonolysis of β-caryophyllene, ozonolysis of limonene, and photo-oxidation of toluene. LLPS was observed at greater than ~95 %more » RH in the biogenic SOM particles derived from β-caryophyllene and limonene while LLPS was not observed in the anthropogenic SOM particles derived from toluene. This work combined with the earlier work on LLPS in SOM particles free of inorganic salts suggests that the occurrence of LLPS in SOM particles free of inorganic salts is related to the oxygen-to-carbon elemental ratio (O : C) of the organic material. These results help explain the difference between the hygroscopic parameter κ of SOM particles measured above and below water saturation in the laboratory and field, and have implications for predicting the cloud condensation nucleation properties of SOM particles.« less

Liquid–liquid phase separation in particles containing secondary organic material free of inorganic salts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Mijung; Liu, Pengfei; Martin, Scot T.

Particles containing secondary organic material (SOM) are ubiquitous in the atmosphere and play a role in climate and air quality. Recently, research has shown that liquid–liquid phase separation (LLPS) occurs at high relative humidity (RH) (greater than ~95 %) in α-pinene-derived SOM particles free of inorganic salts, while LLPS does not occur in isoprene-derived SOM particles free of inorganic salts. We expand on these findings by investigating LLPS at 290 ± 1 K in SOM particles free of inorganic salts produced from ozonolysis of β-caryophyllene, ozonolysis of limonene, and photo-oxidation of toluene. LLPS was observed at greater than ~95 %more » RH in the biogenic SOM particles derived from β-caryophyllene and limonene while LLPS was not observed in the anthropogenic SOM particles derived from toluene. This work combined with the earlier work on LLPS in SOM particles free of inorganic salts suggests that the occurrence of LLPS in SOM particles free of inorganic salts is related to the oxygen-to-carbon elemental ratio (O : C) of the organic material. These results help explain the difference between the hygroscopic parameter κ of SOM particles measured above and below water saturation in the laboratory and field, and have implications for predicting the cloud condensation nucleation properties of SOM particles.« less

The physiological response of two green calcifying algae from the Great Barrier Reef towards high dissolved inorganic and organic carbon (DIC and DOC) availability.

PubMed

Meyer, Friedrich Wilhelm; Vogel, Nikolas; Teichberg, Mirta; Uthicke, Sven; Wild, Christian

2015-01-01

Increasing dissolved inorganic carbon (DIC) concentrations associated with ocean acidification can affect marine calcifiers, but local factors, such as high dissolved organic carbon (DOC) concentrations through sewage and algal blooms, may interact with this global factor. For calcifying green algae of the genus Halimeda, a key tropical carbonate producer that often occurs in coral reefs, no studies on these interactions have been reported. These data are however urgently needed to understand future carbonate production. Thus, we investigated the independent and combined effects of DIC (pCO2 402 μatm/ pHtot 8.0 and 996 μatm/ pHtot 7.7) and DOC (added as glucose in 0 and 294 μmol L-1) on growth, calcification and photosynthesis of H. macroloba and H. opuntia from the Great Barrier Reef in an incubation experiment over 16 days. High DIC concentrations significantly reduced dark calcification of H. opuntia by 130 % and led to net dissolution, but did not affect H. macroloba. High DOC concentrations significantly reduced daily oxygen production of H. opuntia and H. macroloba by 78 % and 43 %, respectively, and significantly reduced dark calcification of H. opuntia by 70%. Combined high DIC and DOC did not show any interactive effects for both algae, but revealed additive effects for H. opuntia where the combination of both factors reduced dark calcification by 162 % compared to controls. Such species-specific differences in treatment responses indicate H. opuntia is more susceptible to a combination of high DIC and DOC than H. macroloba. From an ecological perspective, results further suggest a reduction of primary production for Halimeda-dominated benthic reef communities under high DOC concentrations and additional decreases of carbonate accretion under elevated DIC concentrations, where H. opuntia dominates the benthic community. This may reduce biogenic carbonate sedimentation rates and hence the buffering capacity against further ocean acidification.

The carbon count of 2000 years of rice cultivation.

PubMed

Kalbitz, Karsten; Kaiser, Klaus; Fiedler, Sabine; Kölbl, Angelika; Amelung, Wulf; Bräuer, Tino; Cao, Zhihong; Don, Axel; Grootes, Piet; Jahn, Reinhold; Schwark, Lorenz; Vogelsang, Vanessa; Wissing, Livia; Kögel-Knabner, Ingrid

2013-04-01

More than 50% of the world's population feeds on rice. Soils used for rice production are mostly managed under submerged conditions (paddy soils). This management, which favors carbon sequestration, potentially decouples surface from subsurface carbon cycling. The objective of this study was to elucidate the long-term rates of carbon accrual in surface and subsurface soil horizons relative to those of soils under nonpaddy management. We assessed changes in total soil organic as well as of inorganic carbon stocks along a 2000-year chronosequence of soils under paddy and adjacent nonpaddy management in the Yangtze delta, China. The initial organic carbon accumulation phase lasts much longer and is more intensive than previously assumed, e.g., by the Intergovernmental Panel on Climate Change (IPCC). Paddy topsoils accumulated 170-178 kg organic carbon ha(-1) a(-1) in the first 300 years; subsoils lost 29-84 kg organic carbon ha(-1) a(-1) during this period of time. Subsoil carbon losses were largest during the first 50 years after land embankment and again large beyond 700 years of cultivation, due to inorganic carbonate weathering and the lack of organic carbon replenishment. Carbon losses in subsoils may therefore offset soil carbon gains or losses in the surface soils. We strongly recommend including subsoils into global carbon accounting schemes, particularly for paddy fields. © 2012 Blackwell Publishing Ltd.

Mental Health and the TC. Chapter 5.

ERIC Educational Resources Information Center

Acampora, Alfonso P., Ed.; Nebelkopf, Ethan, Ed.

This document contains 19 papers from the ninth World Conference of Therapeutic Communities (TCs) that deal with the interface between the mental health establishments and the TC. Papers include: (1) "Psychiatry and the TC" (Jerome Jaffe); (2) "The Chemical Brain" (Sidney Cohen); (3) "Where Does the TC Fail?" (Ab…

Alloy-Controlled Work Function for Enhanced Charge Extraction in All-Inorganic CsPbBr3 Perovskite Solar Cells.

PubMed

Ding, Jie; Zhao, Yuanyuan; Duan, Jialong; He, Benlin; Tang, Qunwei

2018-05-09

All-inorganic CsPbX 3 (X=I, Br) perovskite solar cells are regarded as cost-effective and stable alternatives for next-generation photovoltaics. However, sluggish charge extraction at CsPbX 3 /charge-transporting material interfaces, which arises from large interfacial energy differences, have markedly limited the further enhancement of solar cell performance. In this work, the work function (WF) of the back electrode is tuned by doping alloyed PtNi nanowires in carbon ink to promote hole extraction from CsPbBr 3 halides, while an intermediate energy by setting carbon quantum dots (CQDs) at TiO 2 /CsPbBr 3 interface bridges electron transportation. The preliminary results demonstrate that the matching WFs and intermediate energy level markedly reduce charge recombination. A power conversion efficiency of 7.17 % is achieved for the WF-tuned all-inorganic perovskite solar cell, in comparison with 6.10 % for the pristine device, and this is further increased to 7.86 % by simultaneously modifying with CQDs. The high efficiency and improved stability make WF-controlled all-inorganic perovskite solar cells promising to develop advanced photovoltaic platforms. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

High cell density cultivation of a novel Aurantiochytrium sp. strain TC 20 in a fed-batch system using glycerol to produce feedstock for biodiesel and omega-3 oils.

PubMed

Lee Chang, Kim Jye; Dumsday, Geoff; Nichols, Peter D; Dunstan, Graeme A; Blackburn, Susan I; Koutoulis, Anthony

2013-08-01

A recently isolated Australian Aurantiochytrium sp. strain TC 20 was investigated using small-scale (2 L) bioreactors for the potential of co-producing biodiesel and high-value omega-3 long-chain polyunsaturated fatty acids. Higher initial glucose concentration (100 g/L compared to 40 g/L) did not result in markedly different biomass (48 g/L) or fatty acid (12-14 g/L) yields by 69 h. This comparison suggests factors other than carbon source were limiting biomass production. The effect of both glucose and glycerol as carbon sources for Aurantiochytrium sp. strain TC 20 was evaluated in a fed-batch process. Both glucose and glycerol resulted in similar biomass yields (57 and 56 g/L, respectively) by 69 h. The agro-industrial waste from biodiesel production-glycerol-is a suitable carbon source for Aurantiochytrium sp. strain TC 20. Approximately half the fatty acids from Aurantiochytrium sp. strain TC 20 are suitable for development of sustainable, low emission sources of transportation fuels and bioproducts. To further improve biomass and oil production, fortification of the feed with additional nutrients (nitrogen sources, trace metals and vitamins) improved the biomass yield from 56 g/L (34 % total fatty acids) to 71 g/L (52 % total fatty acids, cell dry weight) at 69 h; these yields are to our knowledge around 70 % of the biomass yields achieved, however, in less than half of the time by other researchers using glycerol and markedly greater than achieved using other industrial wastes. The fast growth and suitable fatty acid profile of this newly isolated Aurantiochytrium sp. strain TC 20 highlights the potential of co-producing the drop-in biodiesel and high value omega-3 oils.

Effects of Vegetation Removal and Soil Disturbance on Soil Organic and Inorganic Carbon Dynamics in California Desert Ecosystems

NASA Astrophysics Data System (ADS)

Swanson, A. C.; Allen, E. B.; Allen, M. F.; Hernandez, R. R.

2015-12-01

Solar energy developments are projected to be deployed over desert wildland areas with deep soil inorganic carbon (SIC) deposits, which often involves elimination of deep-rooted vegetation. This land cover change may systemically alter SIC pools since respired CO2 is the carbon (C) source during SIC formation. We sought to understand how removal of creosote bush scrub affects soil C pools. We hypothesized that vegetation is important for maintaining SIC and soil organic C (SOC) pools and that disturbance to the vegetation and soil will change CO2 flux with increased losses from SIC. Soils were collected from sites that had intact creosote bush scrub habitat adjacent to disturbed, bare areas where the native vegetation had been previously removed. Samples were taken from beneath shrub canopies and interspaces in intact areas, and from random points in the disturbed area. Soils were analyzed for SIC, SOC, microbial and labile C, and δ13C. Soils were also incubated to determine the potential CO2 flux from disturbed and undisturbed soils along with the sources of CO2. Three replicates per soil underwent a control and water addition treatment and flux and δ13C of CO2 were measured continuously. Control replicates yielded no significant CO2 flux. CO2 flux from watered soils was higher beneath shrub canopy (18.57µmol g soil-1 day-1±1.86) than the interspace soils (0.86 µmol g soil-1 day-1±0.17). Soils collected from bare areas had an intermediate flux (5.41 µmol g soil-1 day-1±2.68 and 3.68 µmol g soil-1 day-1±0.85, respectively) lying between shrub canopy and interspace soils. There was no significant difference between the δ13C values of CO2 from shrub canopy and interspace soils, both of which had a very low δ13C values (-22.60‰±0.64 and -23.88‰±0.89, respectively), resembling that of organic C. However, the isotopic values of CO2 from disturbed soils were significantly higher (-16.68‰±1.36 and -15.22‰±2.12, respectively) suggesting that these

Ablation properties of inorganic filler modified benzoxazine composite coating irradiated by high-intensity continuous laser

NASA Astrophysics Data System (ADS)

Xu, Feng; Ma, Zhuang; Li, Hezhang; Gao, Lihong; Wang, Fuchi

2017-05-01

Benzoxazine resin with good heat resistance, low combustion heat release and high char yield is a promising thermosetting resin. Meanwhile, research shows that the inorganic filler can effectively improve the thermodynamic property of the resin. It makes that the inorganic filler modified benzoxazine may have a potential application in laser ablation. The benzoxazine coating with and without inorganic filler ammonium polyphosphate, melamine and pentaerythritol (P-BOZ and BOZ) were prepared by brush and thermal curing method. The ablation properties of these coatings irradiated by high-intensity laser were investigated. The scanning electron microscope, Raman spectroscopy and thermal gravimetric analysis were used to characterize the micrographs, carbon layer structure and thermodynamic property of the sample. Results show that the composite coating has excellent thermal protective properties. The back temperature of 20 wt% P-BOZ coating under different parameter laser power (1000W/cm2, 5s; 1000W/cm2, 10s) are 40% lower than these of the BOZ coating and the 20 wt% P-BOZ has higher mass ablation rate. In the surface layer of the irradiated area, dense carbon layer is produced which reduces the absorb of the laser energy of the interior. In the interior of the sample, a large number of closed bell shaped holes are generated which are beneficial to obstruct the heat conduction.

Variation in the carbon cycle of the Sevastopol Bay (Black Sea)

NASA Astrophysics Data System (ADS)

Orekhova, N. A.; Konovalov, S. K.

2018-01-01

Continuous increase in CO2 inventory in the ocean results in dramatic changes in marine biogeochemistry, e.g. acidification. That is why temporal and spatial variabilities in atmospheric pCO2 and dissolved inorganic carbon, including CO2, pH and alkalinity in water, as well as organic and inorganic carbon in bottom sediments have to be studied together making possible to resolve the key features of the carbon cycle transformation. A 30% increase of pCO2 in the Sevastopol Bay for 2008 - 2016 evidences changes in the DIC components ratios and a significant decrease in the ability to absorb atmospheric CO2 by surface waters. High organic carbon content in the bottom sediments and predominance of organic carbon production in the biological pump at inner parts of the bay reveal ongoing transformation of the carbon cycle. This has negative consequences for recreation, social and economic potentials of the Sevastopol region.

Inorganic dual-layer microporous supported membranes

DOEpatents

Brinker, C. Jeffrey; Tsai, Chung-Yi; Lu, Yungfeng

2003-03-25

The present invention provides for a dual-layer inorganic microporous membrane capable of molecular sieving, and methods for production of the membranes. The inorganic microporous supported membrane includes a porous substrate which supports a first inorganic porous membrane having an average pore size of less than about 25 .ANG. and a second inorganic porous membrane coating the first inorganic membrane having an average pore size of less than about 6 .ANG.. The dual-layered membrane is produced by contacting the porous substrate with a surfactant-template polymeric sol, resulting in a surfactant sol coated membrane support. The surfactant sol coated membrane support is dried, producing a surfactant-templated polymer-coated substrate which is calcined to produce an intermediate layer surfactant-templated membrane. The intermediate layer surfactant-templated membrane is then contacted with a second polymeric sol producing a polymeric sol coated substrate which is dried producing an inorganic polymeric coated substrate. The inorganic polymeric coated substrate is then calcined producing an inorganic dual-layered microporous supported membrane in accordance with the present invention.

Matrices for Sensors from Inorganic, Organic, and Biological Nanocomposites

PubMed Central

Nicolini, Claudio; Sivozhelezov, Victor; Bavastrello, Valter; Bezzerra, Tercio; Scudieri, Dora; Spera, Rosanna; Pechkova, Eugenia

2011-01-01

Matrices and sensors resulting from inorganic, organic and biological nanocomposites are presented in this overview. The term nanocomposite designates a solid combination of a matrix and of nanodimensional phases differing in properties from the matrix due to dissimilarities in structure and chemistry. The nanoocomposites chosen for a wide variety of health and environment sensors consist of Anodic Porous Allumina and P450scc, Carbon nanotubes and Conductive Polymers, Langmuir Blodgett Films of Lipases, Laccases, Cytochromes and Rhodopsins, Three-dimensional Nanoporous Materials and Nucleic Acid Programmable Protein Arrays. PMID:28824154

Effects of post-sampling conditions on ambient carbon aerosol filter measurements

NASA Astrophysics Data System (ADS)

Dillner, Ann M.; Phuah, Chin H.; Turner, Jay R.

2009-12-01

Ambient carbonaceous material collected on quartz filters is prone to measurement artifacts due to material gained or lost during post-sampling field latency, shipping, and storage. In seventeen sampling events over a one year period, ambient PM 2.5 aerosols were collected on quartz filters (without denuders) and subjected to various filter treatments to assess the potential for and extent of artifacts. The filter treatments simulated post-sampling environments that filters may be exposed to and included: storage at 40 °C for up to 96 h, storage at -16 °C for 48 h, and storage at room temperature (˜21 °C) for 48 h. Carbon mass on the filters was measured using a thermal-optical method. The total carbon (TC), total organic carbon (TOC) and total elemental carbon (TEC) as well as carbon thermal fraction masses were obtained. Statistical analyses were performed to identify significant differences in carbon fraction concentrations between filters analyzed immediately after sampling and after being subjected to treatment. TOC and TC concentrations decreased by on average 15 ± 5% and 10 ± 4%, respectively, for filters maintained at 40 °C for 96 h but did not change for filters stored at room temperature or frozen for 48 h. TEC did not change for any of the filter treatments. The mass concentration for the organic carbon thermal fraction that evolves at the lowest temperature step (OC1) decreased with increasing storage time at 40 °C with average losses of 70 ± 7% after 96 h. Therefore, OC1 is not a stable measurement due to post-sampling conditions that may be encountered. This work demonstrates that TOC and TC can have substantial measurement artifacts on filters subjected to field latency and other non-temperature controlled post-sampling handling, compared to the carbon loadings on the filter at the end of the sampling period.

Pressure and high-Tc superconductivity in sulfur hydrides.

PubMed

Gor'kov, Lev P; Kresin, Vladimir Z

2016-05-11

The paper discusses fundamentals of record-TC superconductivity discovered under high pressure in sulfur hydride. The rapid increase of TC with pressure in the vicinity of Pcr ≈ 123GPa is interpreted as the fingerprint of a first-order structural transition. Based on the cubic symmetry of the high-TC phase, it is argued that the lower-TC phase has a different periodicity, possibly related to an instability with a commensurate structural vector. In addition to the acoustic branches, the phonon spectrum of H3S contains hydrogen modes with much higher frequencies. Because of the complex spectrum, usual methods of calculating TC are here inapplicable. A modified approach is formulated and shown to provide realistic values for TC and to determine the relative contributions of optical and acoustic branches. The isotope effect (change of TC upon Deuterium for Hydrogen substitution) originates from high frequency phonons and differs in the two phases. The decrease of TC following its maximum in the high-TC phase is a sign of intermixing with pairing at hole-like pockets which arise in the energy spectrum of the cubic phase at the structural transition. On-pockets pairing leads to the appearance of a second gap and is remarkable for its non-adiabatic regime: hydrogen mode frequencies are comparable to the Fermi energy.

Effects of High Dissolved Inorganic and Organic Carbon Availability on the Physiology of the Hard Coral Acropora millepora from the Great Barrier Reef

PubMed Central

Meyer, Friedrich W.; Vogel, Nikolas; Diele, Karen; Kunzmann, Andreas; Uthicke, Sven; Wild, Christian

2016-01-01

Coral reefs are facing major global and local threats due to climate change-induced increases in dissolved inorganic carbon (DIC) and because of land-derived increases in organic and inorganic nutrients. Recent research revealed that high availability of labile dissolved organic carbon (DOC) negatively affects scleractinian corals. Studies on the interplay of these factors, however, are lacking, but urgently needed to understand coral reef functioning under present and near future conditions. This experimental study investigated the individual and combined effects of ambient and high DIC (pCO2 403 μatm/ pHTotal 8.2 and 996 μatm/pHTotal 7.8) and DOC (added as Glucose 0 and 294 μmol L-1, background DOC concentration of 83 μmol L-1) availability on the physiology (net and gross photosynthesis, respiration, dark and light calcification, and growth) of the scleractinian coral Acropora millepora (Ehrenberg, 1834) from the Great Barrier Reef over a 16 day interval. High DIC availability did not affect photosynthesis, respiration and light calcification, but significantly reduced dark calcification and growth by 50 and 23%, respectively. High DOC availability reduced net and gross photosynthesis by 51% and 39%, respectively, but did not affect respiration. DOC addition did not influence calcification, but significantly increased growth by 42%. Combination of high DIC and high DOC availability did not affect photosynthesis, light calcification, respiration or growth, but significantly decreased dark calcification when compared to both controls and DIC treatments. On the ecosystem level, high DIC concentrations may lead to reduced accretion and growth of reefs dominated by Acropora that under elevated DOC concentrations will likely exhibit reduced primary production rates, ultimately leading to loss of hard substrate and reef erosion. It is therefore important to consider the potential impacts of elevated DOC and DIC simultaneously to assess real world scenarios, as

Effects of High Dissolved Inorganic and Organic Carbon Availability on the Physiology of the Hard Coral Acropora millepora from the Great Barrier Reef.

PubMed

Meyer, Friedrich W; Vogel, Nikolas; Diele, Karen; Kunzmann, Andreas; Uthicke, Sven; Wild, Christian

2016-01-01

Coral reefs are facing major global and local threats due to climate change-induced increases in dissolved inorganic carbon (DIC) and because of land-derived increases in organic and inorganic nutrients. Recent research revealed that high availability of labile dissolved organic carbon (DOC) negatively affects scleractinian corals. Studies on the interplay of these factors, however, are lacking, but urgently needed to understand coral reef functioning under present and near future conditions. This experimental study investigated the individual and combined effects of ambient and high DIC (pCO2 403 μatm/ pHTotal 8.2 and 996 μatm/pHTotal 7.8) and DOC (added as Glucose 0 and 294 μmol L-1, background DOC concentration of 83 μmol L-1) availability on the physiology (net and gross photosynthesis, respiration, dark and light calcification, and growth) of the scleractinian coral Acropora millepora (Ehrenberg, 1834) from the Great Barrier Reef over a 16 day interval. High DIC availability did not affect photosynthesis, respiration and light calcification, but significantly reduced dark calcification and growth by 50 and 23%, respectively. High DOC availability reduced net and gross photosynthesis by 51% and 39%, respectively, but did not affect respiration. DOC addition did not influence calcification, but significantly increased growth by 42%. Combination of high DIC and high DOC availability did not affect photosynthesis, light calcification, respiration or growth, but significantly decreased dark calcification when compared to both controls and DIC treatments. On the ecosystem level, high DIC concentrations may lead to reduced accretion and growth of reefs dominated by Acropora that under elevated DOC concentrations will likely exhibit reduced primary production rates, ultimately leading to loss of hard substrate and reef erosion. It is therefore important to consider the potential impacts of elevated DOC and DIC simultaneously to assess real world scenarios, as

Highly stretchable carbon aerogels.

PubMed

Guo, Fan; Jiang, Yanqiu; Xu, Zhen; Xiao, Youhua; Fang, Bo; Liu, Yingjun; Gao, Weiwei; Zhao, Pei; Wang, Hongtao; Gao, Chao

2018-02-28

Carbon aerogels demonstrate wide applications for their ultralow density, rich porosity, and multifunctionalities. Their compressive elasticity has been achieved by different carbons. However, reversibly high stretchability of neat carbon aerogels is still a great challenge owing to their extremely dilute brittle interconnections and poorly ductile cells. Here we report highly stretchable neat carbon aerogels with a retractable 200% elongation through hierarchical synergistic assembly. The hierarchical buckled structures and synergistic reinforcement between graphene and carbon nanotubes enable a temperature-invariable, recoverable stretching elasticity with small energy dissipation (~0.1, 100% strain) and high fatigue resistance more than 10 6 cycles. The ultralight carbon aerogels with both stretchability and compressibility were designed as strain sensors for logic identification of sophisticated shape conversions. Our methodology paves the way to highly stretchable carbon and neat inorganic materials with extensive applications in aerospace, smart robots, and wearable devices.

Thermal Conductivity of Ultem(TradeMark)/Carbon Nanofiller Blends

NASA Technical Reports Server (NTRS)

Ghose, S.; Watson, K. A.; Delozier, D. M.; Working, D. C.; Connell, J. W.; Smith, J. G., Jr.; Sun, Y. P.; Lin, Y.

2006-01-01

In an effort to improve polymer thermal conductivity (TC), Ultem(TradeMark) 1000 was compounded with nano-fillers of carbon allotropes. Ultem(TradeMark) 1000 was selected since it is both solution and melt processable. As-received and modified multiwalled carbon nanotubes (MWCNTs), vapor grown carbon nanofibers (CNF) and expanded graphite (EG) were investigated. MWCNTs were modified by functionalizing the surface through oxidization with concentrated acids, mixing with an alkyl bromide, and addition of alkyl and phosphorus compounds after initial treatment with n-butyl lithium. Functionalization was performed to improve the TC compatibility between the resin and MWCNTs. It was postulated that this may provide an improved interface between the MWCNT and the polymer which would result in enhanced TC. The nano-fillers were mixed with Ultem(TradeMark) 1000 in the melt and in solution at concentrations ranging from 5 to 40 wt%. Ribbons were extruded from the blends to form samples where the nano-fillers were aligned to some degree in the extrusion direction. Samples were also fabricated by compression molding resulting in random orientation of the nano-fillers. Thermal properties of the samples were evaluated by Differential Scanning Calorimetry (DSC) and Thermal Gravimetric Analyzer (TGA). Tensile properties of aligned samples were determined at room temperature. The specimens were cut from the ribbons in the extrusion direction; hence the nano-fillers are somewhat aligned in the direction of stress. Typically it was observed that melt mixed samples exhibited superior mechanical properties compared to solution mixed samples. As expected, increased filler loading led to increased modulus and decreased elongation with respect to the neat polymer. The degree of dispersion and alignment of the nano-fillers was determined by high-resolution scanning electron microscopy (HRSEM). HRSEM of the ribbons revealed that the MWCNTs and CNFs were predominantly aligned in the flow

Impeding 99Tc(IV) mobility in novel waste forms

DOE PAGES

Lee, Mal-Soon; Um, Wooyong; Wang, Guohui; ...

2016-06-30

Technetium ( 99Tc) is a long-lived radioactive fission product whose mobility in the subsurface is largely governed by its oxidation state1. Immobilization of Tc in mineral substrates is crucial for radioactive waste management and environmental remediation. Tc(IV) incorporation in spinels2, 3 has been proposed as a novel method to increase Tc retention in glass waste forms. However, experiments with Tc-magnetite under high temperature and oxic conditions showed re-oxidation of Tc(IV) to volatile pertechnetate Tc(VII)O4-.4, 5 Here we address this problem with large-scale ab initio molecular dynamics simulations and propose that elevated temperatures, 1st row transition metal dopants can significantly enhancemore » Tc retention in the order Co > Zn > Ni. Experiments with doped spinels at T=700 ºC provided quantitative confirmation of increased Tc retention in the same order predicted by theory. This work highlights the power of modern state-of-the-art simulations to provide essential insights and generate bottom-up design criteria of complex oxide materials at elevated temperatures.« less

Competition between autotrophic and heterotrophic microbial plankton for inorganic nutrients induced by variability in estuarine biophysicochemical conditions

NASA Astrophysics Data System (ADS)

Williams, A.; Quigg, A.

2016-02-01

Competition for inorganic nutrients between autotrophic and heterotrophic fractions of microbial plankton (0.2-20μm) was investigated at two stations in a sub-tropical estuary, Galveston Bay, Texas. Competition potential between these groups is enhanced because individuals are similar in size, reducing variability among their nutrient uptake efficiencies. Further, in estuaries, allochthonous supplements to autochthonous carbon may satisfy heterotrophic requirements, allowing alternative factors to limit abundance. The relative abundance of autotrophs and heterotrophs stained with SYBR Green I and enumerated on a Beckman Coulter Gallios flow cytometer were evaluated monthly during a year-long study. Shifts in the relative in situ abundance were significantly related to temperature, dissolved inorganic nitrogen (DIN), phosphorous (Pi), and total organic carbon (TOC) concentrations revealing opposing gradients of limitation by different abiotic factors. In corresponding in vitro nutrient enrichment bioassays the relative contribution of autotrophic or heterotrophic microbial plankton to significant enrichment responses varied. Only during macro- (>20μm) phytoplankton blooms do autotrophic microbial plankton respond to nutrient enrichment. Contrastingly, the heterotrophic microbial plankton responded to nutrient enrichment primarily when temperature limitation was alleviated. Therefore, the potential for autotrophic and heterotrophic microbial plankton competition for limiting nutrients is highest when autotrophic microbial plankton are also competing with larger phytoplankton during bloom events. Based on this evidence, we hypothesize that the autotrophic microbial fraction has a competitive advantage over the heterotrophs for inorganic nutrients in Galveston Bay. The observed microbial competition during estuarine phytoplankton blooms may have important consequences on biogeochemical processes including carbon and nutrient cycling.

Thermal Conductivity of Ethylene Vinyl Acetate Copolymer/Carbon Nanofiller Blends

NASA Technical Reports Server (NTRS)

Ghose, S.; Watson, K. A.; Working, D. C.; Connell, J. W.; Smith, J. G., Jr.; Lin, Y.; Sun, Y. P.

2007-01-01

To reduce weight and increase the mobility, comfort, and performance of future spacesuits, flexible, thermally conductive fabrics and plastic tubes are needed for the Liquid Cooling and Ventilation Garment. Such improvements would allow astronauts to operate more efficiently and safely for extended extravehicular activities. As an approach to raise the thermal conductivity (TC) of an ethylene vinyl acetate copolymer (Elvax 260), it was compounded with three types of carbon based nanofillers: multi-walled carbon nanotubes (MWCNTs), vapor grown carbon nanofibers (CNFs), and expanded graphite (EG). In addition, other nanofillers including metallized CNFs, nickel nanostrands, boron nitride, and powdered aluminum were also compounded with Elvax 260 in the melt at various loading levels. In an attempt to improve compatibility between Elvax 260 and the nanofillers, MWCNTs and EG were modified by surface coating and through noncovalent and covalent attachment of organic molecules containing alkyl groups. Ribbons of the nanocomposites were extruded to form samples in which the nanofillers were aligned in the direction of flow. Samples were also fabricated by compression molding to yield nanocomposites in which the nanofillers were randomly oriented. Mechanical properties of the aligned samples were determined by tensile testing while the degree of dispersion and alignment of nanoparticles were investigated using high-resolution scanning electron microscopy. TC measurements were performed using a laser flash (Nanoflash ) technique. TC of the samples was measured in the direction of, and perpendicular to, the alignment direction. Additionally, tubing was also extruded from select nanocomposite compositions and the TC and mechanical flexibility measured.

Kinetics of canine dental calculus crystallization: an in vitro study on the influence of inorganic components of canine saliva.

PubMed

Borah, Ballav M; Halter, Timothy J; Xie, Baoquan; Henneman, Zachary J; Siudzinski, Thomas R; Harris, Stephen; Elliott, Matthew; Nancollas, George H

2014-07-01

This work identifies carbonated hydroxyapatite (CAP) as the primary component of canine dental calculus, and corrects the long held belief that canine dental calculus is primarily CaCO3 (calcite). CAP is known to be the principal crystalline component of human dental calculus, suggesting that there are previously unknown similarities in the calcification that occurs in these two unique oral environments. In vitro kinetic experiments mimicking the inorganic components of canine saliva have examined the mechanisms of dental calculus formation. The solutions were prepared so as to mimic the inorganic components of canine saliva; phosphate, carbonate, and magnesium ion concentrations were varied individually to investigate the roll of these ions in controlling the nature of the phases that is nucleated. To date, the inorganic components of the canine oral systems have not been investigated at concentrations that mimic those in vivo. The mineral composition of the synthetic calculi grown under these conditions closely resembled samples excised from canines. This finding adds new information about calculus formation in humans and canines, and their sensitivity to chemicals used to treat these conditions. Copyright © 2014 Elsevier Inc. All rights reserved.

Remote Monitoring, Inorganic Monitoring

EPA Science Inventory

This chapter provides an overview of applicability, amenability, and operating parameter ranges for various inorganic parameters:this chapter will also provide a compilation of existing and new online technologies for determining inorganic compounds in water samples. A wide vari...

A model for diurnal patterns of carbon fixation in a Precambrian microbial mat based on a modern analog

NASA Technical Reports Server (NTRS)

Rothschild, L. J.

1991-01-01

Microbial mat communities are one of the first and most prevalent biological communities known from the Precambrian fossil record. These fossil mat communities are found as laminated sedimentary rock structures called stromatolites. Using a modern microbial mat as an analog for Precambrian stromatolites, a study of carbon fixation during a diurnal cycle under ambient conditions was undertaken. The rate of carbon fixation depends primarily on the availability of light (consistent with photosynthetic carbon fixation) and inorganic carbon, and not nitrogen or phosphorus. Atmospheric PCO2 is thought to have decreased from 10 bars at 4 Ga (10(9) years before present) to approximately 10(-4) bars today, implying a change in the availability of inorganic carbon for carbon fixation. Experimental manipulation of levels of inorganic carbon to levels that may have been available to Precambrian mat communities resulted in increased levels of carbon fixation during daylight hours. Combining these data with models of daylength during the Precambrian, models are derived for diurnal patterns of photosynthetic carbon fixation in a Precambrian microbial mat community. The models suggest that, even in the face of shorter daylengths during the Precambrian, total daily carbon fixation has been declining over geological time, with most of the decrease having occurred during the Precambrian.

The quest for inorganic fullerenes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pietsch, Susanne; Dollinger, Andreas; Strobel, Christoph H.

2015-10-07

Experimental results of the search for inorganic fullerenes are presented. Mo{sub n}S{sub m}{sup −} and W{sub n}S{sub m}{sup −} clusters are generated with a pulsed arc cluster ion source equipped with an annealing stage. This is known to enhance fullerene formation in the case of carbon. Analogous to carbon, the mass spectra of the metal chalcogenide clusters produced in this way exhibit a bimodal structure. The species in the first maximum at low mass are known to be platelets. Here, the structure of the species in the second maximum is studied by anion photoelectron spectroscopy, scanning transmission electron microscopy, andmore » scanning tunneling microcopy. All experimental results indicate a two-dimensional structure of these species and disagree with a three-dimensional fullerene-like geometry. A possible explanation for this preference of two-dimensional structures is the ability of a two-element material to saturate the dangling bonds at the edges of a platelet by excess atoms of one element. A platelet consisting of a single element only cannot do this. Accordingly, graphite and boron might be the only materials forming nano-spheres because they are the only single element materials assuming two-dimensional structures.« less

Stable carbonous catalyst particles and method for making and utilizing same

DOEpatents

Ganguli, Partha S.; Comolli, Alfred G.

2005-06-14

Stable carbonous catalyst particles composed of an inorganic catalytic metal/metal oxide powder and a carbonaceous binder material are formed having a basic inner substantially uniform-porous carbon coating of the catalytic powder, and may include an outer porous carbon coating layer. Suitable inorganic catalytic powders include zinc-chromite (ZnO/Cr.sub.2 03) and suitable carbonaceous liquid binders having molecular weight of 200-700 include partially polymerized furfuryl alcohol, which are mixed together, shaped and carbonized and partially oxidized at elevated temperature. Such stable carbonous catalyst particles such as 0.020-0.100 inch (0.51-2.54 mm) diameter extrudates, have total carbon content of 2-25 wt. % and improved crush strength of 1.0-5 1b/mn, 50-300 m.sup.2 /g surface area, and can be advantageously utilized in fixed bed or ebullated/fluidized bed reactor operations. This invention also includes method steps for making the stable carbonous catalyst particles having improved particle strength and catalytic activity, and processes for utilizing the active stable carbonous carbon-coated catalysts such as for syn-gas reactions in ebullated/fluidized bed reactors for producing alcohol products and Fischer-Tropsch synthesis liquid products.

The response of inorganic carbon distributions and dynamics to upwelling-favorable winds on the northern Gulf of Mexico during summer

NASA Astrophysics Data System (ADS)

Huang, W.-J.; Cai, W.-J.; Wang, Y.; Hu, X.; Chen, B.; Lohrenz, S. E.; Chakraborty, S.; He, R.; Brandes, J.; Hopkinson, C. S.

2015-12-01

Upwelling-favorable winds and an offshore-distributed Mississippi and Atchafalaya River plume trajectory were observed in summer 2009 in contrast to the mean conditions from 2002 to 2010 (upwelling-unfavorable winds and an alongshore river plume trajectory), a set of conditions which was also observed in summer 2007. The responses of dissolved inorganic carbon (DIC) distributions and dynamics to upwelling-favorable winds are studied by comparing the contrasting conditions between summer 2009 and summer 2007 on the northern Gulf of Mexico. Patterns of surface water partial pressure of CO2 (pCO2), DIC, δ13C in DIC, and total alkalinity (TA) determined in July 2009 and August 2007 were strongly related to river plume trajectories, and differed between the two summers. The slope of the relationship between dissolved oxygen (DO) and DIC in summer 2007 was comparable to the Redfield O/C ratio of 1.3, which was attributed to respiration of organic matter in the bottom water. The slope of the DO and DIC relationship and δ13CDIC values in bottom waters during July 2009 were clearly affected by mixing since their salinities were <35. A three end-member mixing model was used to remove mixing effects in (1) δ13CDIC, to estimate the organic source of respiration, and (2) in DIC concentrations, to calculate DIC removal and release. δ13CDIC results in both summers were consistent with an apparent release of DIC in hypoxic waters (DO less than 2 mg L-1) associated with respiration of surface organic matter. The area-weighted surface DIC removal (i.e., biological production) was lower in 2009 than in 2007 on the shelf, as the plume was distributed offshore. The release of DIC in bottom waters was higher over the shelf in 2009 and was surmised to be related to stronger mixing, which was favorable for the DO supply for respiration. Overall, surface waters on the continental shelf in the region of study in July 2009 acted as a weak CO2 source to the atmosphere, but a weak CO2 sink

Initial direct comparison of 99mTc-TOC and 99mTc-TATE in identifying sites of disease in patients with proven GEP NETs.

PubMed

Cwikla, Jaroslaw B; Mikolajczak, Renata; Pawlak, Dariusz; Buscombe, John R; Nasierowska-Guttmejer, Anna; Bator, Andrzej; Maecke, Helmut R; Walecki, Jerzy

2008-07-01

The imaging of neuroendocrine tumors has become one of the most significant areas in nuclear oncology. In an attempt to provide high-quality imaging and possible sensitivity at a reduced cost, time, and radiation dose, several (99m)Tc agents have been proposed. The aim of this initial study was to compare the tumor uptake and biodistribution of 2 new 6-hydrazinopyridine-3-carboxylic acid (HYNIC)-derivatized Tyr(3)-octreotide analogs, (99m)Tc-[HYNIC,Tyr(3)]octreotide ((99m)Tc-TOC) and (99m)Tc-[HYNIC,Tyr(3),Thr(8)]octreotide ((99m)Tc-TATE), in patients with somatostatin receptor-expressing tumors. Each of 12 patients with proven gastrointestinal pancreatic neuroendocrine tumors received a mean activity of 520 MBq of (99m)Tc-TOC and (99m)Tc-TATE. Scintigraphy with both tracers was performed 3-4 h after their injection using standard whole-body and SPECT imaging. The images were reviewed subjectively by 2 readers, who reported tumor uptake lesion by lesion. Both radiotracers demonstrated concordance between the results in 7 patients (58%). In total, 110 sites of disease were identified with (99m)Tc-TOC, compared with 115 with (99m)Tc-TATE. There was 1 case in which (99m)Tc-TOC identified sites of disease not seen on (99m)Tc-TATE imaging but 4 cases in which some sites of disease were seen with (99m)Tc-TATE and not (99m)Tc-TOC. In this initial study, both tracers seem to show similar sites of tumor, with (99m)Tc-TATE having a slight edge in the total number of lesions seen, especially in lymph node metastases.

The carbon bonus of organic nitrogen enhances nitrogen use efficiency of plants.

PubMed

Franklin, Oskar; Cambui, Camila Aguetoni; Gruffman, Linda; Palmroth, Sari; Oren, Ram; Näsholm, Torgny

2017-01-01

The importance of organic nitrogen (N) for plant nutrition and productivity is increasingly being recognized. Here we show that it is not only the availability in the soil that matters, but also the effects on plant growth. The chemical form of N taken up, whether inorganic (such as nitrate) or organic (such as amino acids), may significantly influence plant shoot and root growth, and nitrogen use efficiency (NUE). We analysed these effects by synthesizing results from multiple laboratory experiments on small seedlings (Arabidopsis, poplar, pine and spruce) based on a tractable plant growth model. A key point is that the carbon cost of assimilating organic N into proteins is lower than that of inorganic N, mainly because of its carbon content. This carbon bonus makes it more beneficial for plants to take up organic than inorganic N, even when its availability to the roots is much lower - up to 70% lower for Arabidopsis seedlings. At equal growth rate, root:shoot ratio was up to three times higher and nitrogen productivity up to 20% higher for organic than inorganic N, which both are factors that may contribute to higher NUE in crop production. © 2016 The Authors Plant, Cell & Environment Published by John Wiley & Sons Ltd.

99mTc-3P4-RGD2 Scintimammography in the Assessment of Breast Lesions: Comparative Study with 99mTc-MIBI

PubMed Central

Gao, Shi; Ji, Tiefeng; Wen, Qiang; Song, Yan; Zhu, Lei; Xu, Zheli; Liu, Lin

2014-01-01

Purpose To compare the potential application of 99mTc-3P-Arg-Gly-Asp (99mTc-3P4-RGD2) scintimammography (SMM) and 99mTc-methoxyisobutylisonitrile (99mTc-MIBI) SMM for the differentiation of malignant from benign breast lesions. Method Thirty-six patients with breast masses on physical examination and/or suspicious mammography results that required fine needle aspiration cytology biopsy (FNAB) were included in the study. 99mTc-3P4-RGD2 and 99mTc-MIBI SMM were performed with single photon emission computed tomography (SPECT) at 60 min and 20 min respectively after intravenous injection of 738±86 MBq radiotracers on a separate day. Images were evaluated by the tumor to non-tumor localization ratios (T/NT). Receiver operating characteristic (ROC) curve analysis was performed on each radiotracer to calculate the cut-off values of quantitative indices and to compare the diagnostic performance for the ability to differentiate malignant from benign diseases. Results The mean T/NT ratio of 99mTc-3P4-RGD2 in malignant lesions was significantly higher than that in benign lesions (3.54±1.51 vs. 1.83±0.98, p<0.001). The sensitivity, specificity, and accuracy of 99mTc-3P4-RGD2 SMM were 89.3%, 90.9% and 89.7%, respectively, with a T/NT cut-off value of 2.40. The mean T/NT ratio of 99mTc-MIBI in malignant lesions was also significantly higher than that in benign lesions (2.86±0.99 vs. 1.51±0.61, p<0.001). The sensitivity, specificity and accuracy of 99mTc-MIBI SMM were 87.5%, 72.7% and 82.1%, respectively, with a T/NT cut-off value of 1.45. According to the ROC analysis, the area under the curve for 99mTc-3P4-RGD2 SMM (area = 0.851) was higher than that for 99mTc-MIBI SMM (area = 0.781), but the statistical difference was not significant. Conclusion 99mTc-3P4-RGD2 SMM does not provide any significant advantage over the established 99mTc-MIBI SMM for the detection of primary breast cancer. The T/NT ratio of 99mTc-3P4-RGD2 SMM was significantly higher than that of 99mTc

Analysis of accumulation of 99mTc-octreotide and 99mTc-EDDA/HYNIC-Tyr3-octreotide in the rat kidneys.

PubMed

Kopecky, Martin; Semecky, Vladimir; Trejtnar, Frantisek; Laznicek, Milan; Laznickova, Alice; Nachtigal, Petr; Decristoforo, Clemens; Mather, Stephen J; Mäcke, Helmut R

2004-02-01

The aim of this study was to compare renal handling and distribution of (99m)Tc-octreotide and (99m)Tc-EDDA/HYNIC-Tyr(3)-octreotide (HYNIC-TOC) in rats. In kidney perfusion experiments, the renal clearance value of (99m)Tc-octreotide was three times lower than that of (99m)Tc-EDDA/HYNIC-TOC. The predominant renal excretion of (99m)Tc-EDDA/HYNIC-TOC was associated with a high and long-term renal accumulation up to 48 hrs. Microautoradiographic results indicated that (99m)Tc-EDDA/HYNIC-TOC was retained mainly in the renal medulla within the cells of the collecting ducts and in the surrounding tissue. Lower positivity was found in the proximal and distal tubular cells. We conclude that the mechanism of renal accumulation of somatostatin analogues renal accumulation is complex and that proximal tubular reabsorption is probably not the main mechanism for uptake of (99m)Tc-EDDA/HYNIC-TOC in the kidneys. The presence of the somatostatin receptors, differences in the tonicity level within kidneys and other possible mechanisms could participate in their renal accumulation.

Simulated Carbon Cycling in a Model Microbial Mat.

NASA Astrophysics Data System (ADS)

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.

Influence of competing inorganic cations on the ion exchange equilibrium of the monovalent organic cation metoprolol on natural sediment.

PubMed

Niedbala, Anne; Schaffer, Mario; Licha, Tobias; Nödler, Karsten; Börnick, Hilmar; Ruppert, Hans; Worch, Eckhard

2013-02-01

The aim of this study was to systematically investigate the influence of the mono- and divalent inorganic ions Na(+) and Ca(2+) on the sorption behavior of the monovalent organic cation metoprolol on a natural sandy sediment at pH=7. Isotherms for the beta-blocker metoprolol were obtained by sediment-water batch tests over a wide concentration range (1-100000 μg L(-1)). Concentrations of the competing inorganic ions were varied within freshwater relevant ranges. Data fitted well with the Freundlich sorption model and resulted in very similar Freundlich exponents (n=0.9), indicating slightly non-linear behavior. Results show that the influence of Ca(2+) compared to Na(+) is more pronounced. A logarithmic correlation between the Freundlich coefficient K(Fr) and the concentration or activity of the competing inorganic ions was found allowing the prediction of metoprolol sorption on the investigated sediment at different electrolyte concentrations. Additionally, the organic carbon of the sediment was completely removed for investigating the influence of organic matter on the sorption of metoprolol. The comparison between the experiments with and without organic carbon removal revealed no significant contribution of the organic carbon fraction (0.1%) to the sorption of metoprolol on the in this study investigated sediment. Results of this study will contribute to the development of predictive models for the transport of organic cations in the subsurface. Copyright © 2012 Elsevier Ltd. All rights reserved.

Novel 99mTc(III)-azide complexes [99mTc(N3)(CDO)(CDOH)2B-R] (CDOH2=cyclohexanedione dioxime) as potential radiotracers for heart imaging.

PubMed

Liu, Min; Zheng, Yumin; Avcibasi, Ugur; Liu, Shuang

2016-11-01

In this study, novel 99m Tc(III)-azide complexes [ 99m Tc(N 3 )(CDO)(CDOH) 2 B-R] ( 99m Tc-ISboroxime-N 3 : R=IS; 99m Tc-MPboroxime-N 3 : R=MP; 99m Tc-PAboroxime-N 3 : R=PA; 99m Tc-PYboroxime-N 3 : R=PY; and 99m Tc-Uboroxime-N 3 : R=5U) were evaluated as heart imaging agents. Complexes [ 99m Tc(N 3 )(CDO)(CDOH) 2 B-R] (R=IS, MP, PA, PY and 5U) were prepared by ligand exchange between NaN 3 and [ 99m TcCl(CDO)(CDOH) 2 B-R]. Biodistribution and imaging studies were carried out in Sprague-Dawley rats. Image quantification was performed to compare their initial heart uptake and myocardial retention. 99m Tc-ISboroxime-N 3 , 99m Tc-PYboroxime-N 3 and 99m Tc-Uboroxime-N 3 were prepared with high RCP (93-98%) while the RCP of 99m Tc-MPboroxime-N 3 and 99m Tc-PAboroxime-N 3 was 80-85%. The myocardial retention curves of 99m Tc-ISboroxime-N 3 , 99m Tc-PYboroxime-N 3 and 99m Tc-Uboroxime-N 3 were best fitted to the bi-exponential decay function. The half-time of the fast component was 1.6±0.4min for 99m Tc-ISboroxime-N 3 , 0.7±0.1min for 99m Tc-PYboroxime-N 3 and 0.9±0.4min for 99m Tc-Uboroxime-N 3 . The 2-min heart uptake from biodistribution studies followed the ranking order of 99m Tc-ISboroxime-N 3 (3.60±0.68%ID/g)> 99m Tc-PYboroxime-N 3 (2.35±0.37%ID/g)≫ 99m Tc-Uboroxime-N 3 (1.29±0.06%ID/g). 99m Tc-ISboroxime-N 3 had the highest 2-min heart uptake among 99m Tc radiotracers revaluated in SD rats. High quality SPECT images were obtained with the right and left ventricular walls being clearly delineated. The best image acquisition window was 0-5min for 99m Tc-ISboroxime-N 3 . Both azide coligand and boronate caps had significant impact on the heart uptake and myocardial retention of complexes [ 99m Tc(N 3 )(CDO)(CDOH) 2 B-R]. Among the radiotracers evaluated in SD rats, 99m Tc-ISboroxime-N 3 has the highest initial heart uptake with the heart retention comparable to that of 99m Tc-Teboroxime. 99m Tc-ISboroxime-N 3 is a promising alternative to 99m Tc-Teboroxime for

New multifunctional porous materials based on inorganic-organic hybrid single-walled carbon nanotubes: gas storage and high-sensitive detection of pesticides.

PubMed

Wang, Feng; Zhao, Jinbo; Gong, Jingming; Wen, Lili; Zhou, Li; Li, Dongfeng

2012-09-10

Single-walled carbon nanotubes (SWNTs) that are covalently functionalized with benzoic acid (SWNT-PhCOOH) can be integrated with transition-metal ions to form 3D porous inorganic-organic hybrid frameworks (SWNT-Zn). In particular, N(2)-adsorption analysis shows that the BET surface area increases notably from 645.3 to 1209.9 m(2)  g(-1) for SWNTs and SWNT-Zn, respectively. This remarkable enhancement in the surface area of SWNT-Zn is presumably due to the microporous motifs from benzoates coordinated to intercalated zinc ions between the functionalized SWNTs; this assignment was also corroborated by NLDFT pore-size distributions. In addition, the excess-H(2)-uptake maximum of SWNT-Zn reaches about 3.1 wt. % (12 bar, 77 K), which is almost three times that of the original SWNTs (1.2 wt. % at 12 bar, 77 K). Owing to its inherent conductivity and pore structure, as well as good dispersibility, SWNT-Zn is an effective candidate as a sensitive electrochemical stripping voltammetric sensor for organophosphate pesticides (OPs): By using solid-phase extraction (SPE) with SWNT-Zn-modified glassy carbon electrode, the detection limit of methyl parathion (MP) is 2.3 ng mL(-1). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High temperature superconductivity in distinct phases of amorphous B-doped Q-carbon

NASA Astrophysics Data System (ADS)

Narayan, Jagdish; Bhaumik, Anagh; Sachan, Ritesh

2018-04-01

Distinct phases of B-doped Q-carbon are formed when B-doped and undoped diamond tetrahedra are packed randomly after nanosecond laser melting and quenching of carbon. By changing the ratio of doped to undoped tetrahedra, distinct phases of B-doped Q-carbon with concentration varying from 5.0% to 50.0% can be created. We have synthesized three distinct phases of amorphous B-doped Q-carbon, which exhibit high-temperature superconductivity following the Bardeen-Cooper-Schrieffer mechanism. The first phase (QB1) has a B-concentration ˜17 at. % (Tc = 37 K), the second phase (QB2) has a B-concentration ˜27 at. % (Tc = 55 K), and the third phase (QB3) has a B-concentration ˜45 at. % (Tc expected over 100 K). From geometrical modeling, we derive that QB1 consists of randomly packed tetrahedra, where one out of every three tetrahedra contains a B atom in the center which is sp3 bonded to four carbon atoms with a concentration of 16.6 at. %. QB2 consists of randomly packed tetrahedra, where one out of every two tetrahedra contains a B atom in the center which is sp3 bonded to four carbon atoms with a concentration of 25 at. %. QB3 consists of randomly packed tetrahedra, where every tetrahedron contains a B atom in the center which is sp3 bonded to four carbon atoms with a concentration of 50 at. %. We present detailed high-resolution TEM results on structural characterization, and EELS and Raman spectroscopy results on the bonding characteristics of B and C atoms. From these studies, we conclude that the high electronic density of states near the Fermi energy level coupled with moderate electron-phonon coupling result in high-temperature superconductivity in B-doped Q-carbon.

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

USGS Publications Warehouse

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

2012-01-01

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

Inorganic Crystal Structure Database (ICSD)

National Institute of Standards and Technology Data Gateway

SRD 84 FIZ/NIST Inorganic Crystal Structure Database (ICSD) (PC database for purchase)   The Inorganic Crystal Structure Database (ICSD) is produced cooperatively by the Fachinformationszentrum Karlsruhe(FIZ) and the National Institute of Standards and Technology (NIST). The ICSD is a comprehensive collection of crystal structure data of inorganic compounds containing more than 140,000 entries and covering the literature from 1915 to the present.

Bioinspired mineralization of inorganics from aqueous media controlled by synthetic polymers.

PubMed

Gorna, Katarzyna; Muñoz-Espí, Rafael; Gröhn, Franziska; Wegner, Gerhard

2007-02-12

The formation of inorganic structures in nature is commonly controlled by biogenic macromolecules. The understanding of mineralization phenomena and the nucleation and growth mechanisms involved is still a challenge in science but also of great industrial interest. This article focuses on the formation and mineralization of two archetypical inorganic materials: zinc oxide and amorphous calcium carbonate (ACC). Zinc oxide is selected as a model compound to investigate the role that polymers play in mineralization. Most of the effort has been devoted to the investigation of the effects of double-hydrophilic block and graft copolymers. Recent work has demonstrated that latex particles synthesized by miniemulsion polymerization, properly functionalized by various chemical groups, have similar effects to conventional block copolymers and are excellently suited for morphology control of ZnO crystals. Latex particles might serve as analogues of natural proteins in biomineralization. The second example presented, ACC, addresses the issue of whether this amorphous phase is an intermediate in the biomineralization of calcite, vaterite, or aragonite. Conditions under which amorphous calcium carbonate can be obtained as nanometer-sized spheres as a consequence of a liquid-liquid phase segregation are presented. Addition of specific block copolymers allows control of the particle size from the micrometer to the submicrometer length scale. The physical properties of novel materials synthesized from concentrated solution and their potential applications as a filler of polymers are also discussed.

Slow-Photon-Effect-Induced Photoelectrical-Conversion Efficiency Enhancement for Carbon-Quantum-Dot-Sensitized Inorganic CsPbBr3 Inverse Opal Perovskite Solar Cells.

PubMed

Zhou, Shujie; Tang, Rui; Yin, Longwei

2017-11-01

All-inorganic cesium lead halide perovskite is suggested as a promising candidate for perovskite solar cells due to its prominent thermal stability and comparable light absorption ability. Designing textured perovskite films rather than using planar-architectural perovskites can indeed optimize the optical and photoelectrical conversion performance of perovskite photovoltaics. Herein, for the first time, this study demonstrates a rational strategy for fabricating carbon quantum dot (CQD-) sensitized all-inorganic CsPbBr 3 perovskite inverse opal (IO) films via a template-assisted, spin-coating method. CsPbBr 3 IO introduces slow-photon effect from tunable photonic band gaps, displaying novel optical response property visible to naked eyes, while CQD inlaid among the IO frameworks not only broadens the light absorption range but also improves the charge transfer process. Applied in the perovskite solar cells, compared with planar CsPbBr 3 , slow-photon effect of CsPbBr 3 IO greatly enhances the light utilization, while CQD effectively facilitates the electron-hole extraction and injection process, prolongs the carrier lifetime, jointly contributing to a double-boosted power conversion efficiency (PCE) of 8.29% and an increased incident photon-to-electron conversion efficiency of up to 76.9%. The present strategy on CsPbBr 3 IO to enhance perovskite PCE can be extended to rationally design other novel optoelectronic devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dissolved organic and inorganic matter in bulk deposition of a coastal urban area: an integrated approach.

PubMed

Santos, Patrícia S M; Santos, Eduarda B H; Duarte, Armando C

2014-12-01

Bulk deposition can remove atmospheric organic and inorganic pollutants that may be associated with gaseous, liquid or particulate phases. To the best of our knowledge, few studies have been carried out, which simultaneously analyse the presence of organic and inorganic fractions in rainwater. In the present work, the complementarity of organic and inorganic data was assessed, through crossing data of some organic [DOC (dissolved organic carbon), absorbance at 250 nm (UV250nm), integrated fluorescence] and inorganic [H(+), NH4(+), NO3(-), non sea salt sulphate (NSS-SO4(2-))] parameters measured in bulk deposition in the coastal urban area of Aveiro. The organic and inorganic parameters analysed were positively correlated (p<0.001) except for H(+), which suggests that a constant fraction of chromophoric dissolved organic matter (CDOM) came from anthropogenic sources. Furthermore, the inverse correlations observed for the organic and inorganic parameters with the precipitation amount suggest that organic and inorganic fractions were incorporated into the rainwater partially by below-cloud scavenging of airborne particulate matter. This is in accordance with the high values of DOC and NO3(-) found in samples associated with marine air masses, which were linked in part to the contribution of local emissions from vehicular traffic. DOC of bulk deposition was the predominant constituent when compared with the constituents H(+), NH4(+), NO3(-) and NSS-SO4(2-), and consequently bulk deposition flux was also highest for DOC, highlighting the importance of DOC and of anthropogenic ions being simultaneously removed from the atmosphere by bulk deposition. However, it was verified that the contribution of anthropogenic sources to the DOC of bulk deposition may be different for distinct urban areas. Thus, it is recommended that organic and inorganic fractions of bulk deposition are studied together. Copyright © 2014. Published by Elsevier Ltd.

The Tribolium chitin synthase genes TcCHS1 and TcCHS2 are specialized for synthesis of epidermal cuticle and midgut peritrophic matrix.

PubMed

Arakane, Y; Muthukrishnan, S; Kramer, K J; Specht, C A; Tomoyasu, Y; Lorenzen, M D; Kanost, M; Beeman, R W

2005-10-01

Functional analysis of the two chitin synthase genes, TcCHS1 and TcCHS2, in the red flour beetle, Tribolium castaneum, revealed unique and complementary roles for each gene. TcCHS1-specific RNA interference (RNAi) disrupted all three types of moult (larval-larval, larval-pupal and pupal-adult) and greatly reduced whole-body chitin content. Exon-specific RNAi showed that splice variant 8a of TcCHS1 was required for both the larval-pupal and pupal-adult moults, whereas splice variant 8b was required only for the latter. TcCHS2-specific RNAi had no effect on metamorphosis or on total body chitin content. However, RNAi-mediated down-regulation of TcCHS2, but not TcCHS1, led to cessation of feeding, a dramatic shrinkage in larval size and reduced chitin content in the midgut.

Assessment of the direct cyclotron production of (99m)Tc: An approach to crisis management of (99m)Tc shortage.

PubMed

Rovais, Mohammad Reza Aboudzadeh; Aardaneh, Khosro; Aslani, Gholamreza; Rahiminejad, Ali; Yousefi, Kamran; Boulouri, Fatemeh

2016-06-01

Nowadays, the cyclotron production of technetium-99m ((99m)Tc) has been increased, due to the worldwide (99m)Tc generator shortage. In the present work, an improved strategy for the production of (99m)Tc, using the proton irradiation of the enriched (100)Mo was developed. The performance of this method in terms of the production yield, chemical purity, radiochemical purity, as well as radionuclide purity was evaluated. The average production yield was measured to be 356MBqμA(-1)h(-1). A good agreement was found between the calculated production yield and the experimental one. The radiochemical separation and total recovery yields of (99m)Tc were 92% and 69%, respectively. The radiochemical and the radionuclide purities of the (99m)Tc were 99% and >99.99% at the end of purification, respectively. The results of quality control tests (QC) support the concept that cyclotron-produced (99m)Tc is suitable for preparation of USP-compliant. Copyright © 2016 Elsevier Ltd. All rights reserved.

Room-temperature ductile inorganic semiconductor.

PubMed

Shi, Xun; Chen, Hongyi; Hao, Feng; Liu, Ruiheng; Wang, Tuo; Qiu, Pengfei; Burkhardt, Ulrich; Grin, Yuri; Chen, Lidong

2018-05-01

Ductility is common in metals and metal-based alloys, but is rarely observed in inorganic semiconductors and ceramic insulators. In particular, room-temperature ductile inorganic semiconductors were not known until now. Here, we report an inorganic α-Ag 2 S semiconductor that exhibits extraordinary metal-like ductility with high plastic deformation strains at room temperature. Analysis of the chemical bonding reveals systems of planes with relatively weak atomic interactions in the crystal structure. In combination with irregularly distributed silver-silver and sulfur-silver bonds due to the silver diffusion, they suppress the cleavage of the material, and thus result in unprecedented ductility. This work opens up the possibility of searching for ductile inorganic semiconductors/ceramics for flexible electronic devices.

Room-temperature ductile inorganic semiconductor

NASA Astrophysics Data System (ADS)

Shi, Xun; Chen, Hongyi; Hao, Feng; Liu, Ruiheng; Wang, Tuo; Qiu, Pengfei; Burkhardt, Ulrich; Grin, Yuri; Chen, Lidong

2018-05-01

Ductility is common in metals and metal-based alloys, but is rarely observed in inorganic semiconductors and ceramic insulators. In particular, room-temperature ductile inorganic semiconductors were not known until now. Here, we report an inorganic α-Ag2S semiconductor that exhibits extraordinary metal-like ductility with high plastic deformation strains at room temperature. Analysis of the chemical bonding reveals systems of planes with relatively weak atomic interactions in the crystal structure. In combination with irregularly distributed silver-silver and sulfur-silver bonds due to the silver diffusion, they suppress the cleavage of the material, and thus result in unprecedented ductility. This work opens up the possibility of searching for ductile inorganic semiconductors/ceramics for flexible electronic devices.

Upgrading agricultural wastes using three different carbonization methods: Thermal, hydrothermal and vapothermal.

PubMed

Yeoh, Keat-Hor; Shafie, S A; Al-Attab, K A; Zainal, Z A

2018-06-15

In this study, three different methods for high quality solid fuel production were tested and compared experimentally. Oil palm empty fruit bunches, mesocarp fibers, palm kernel shells and rubber seeds shells were treated using thermal (TC), hydrothermal (HTC) and vapothermal (VTC) carbonization. All thermochemical methods were accomplished by using a custom made batch-type reactor. Utilization of novel single reactor equipped with suspended internal container provided efficient operation since both steam generator and raw materials were placed inside the same reactor. Highest energy densification was achieved by VTC process followed by TC and HTC processes. The heating value enhancement in VTC and TC was achieved by the increase in fixed carbon content and reduction in volatile matter. The formation of the spherical components in HTC hydrochar which gave a sharp peak at 340 °C in the DTG curves was suggested as the reason that led to the increment in energy content. Copyright © 2018 Elsevier Ltd. All rights reserved.

Measuring functioning hepatocytes using Tc-99m galactosylneoglycoalbumin (Tc-NGA)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stadalnik, R.C.; Vera, D.R.; Quadro, R.E.

1984-01-01

Tc-NGA is a synthetic ligand which binds only to hepatic binding protein (HBP), a receptor found only in the liver. It exhibits the properties of high tissue specificity, affinity-dependent uptake, and dose-dependent uptake. Tc-NGA provides an opportunity to study the functioning hepatocyte. The authors evaluated the usefulness of this technique in patients with hepatitis and hepatoma. After intravenous administration of 5 mCi Tc-NGA, dynamic images were acquired for 30 minutes followed by static views. Estimates of HBP concentrations were obtained by kinetic analysis of blood and liver time-activity curves. Kinetic estimates (reduced chi-squares < 3.0) of HBP correlated well withmore » the clinical course and histology. For example, a patient with hepatoma whose calculated receptor population (functioning hepatocytes) was 3.0 +- 0.9 x 10/sup -7/ mole, which is the normal range, is doing well undergoing chemotherapy. Liver biopsy demonstrated normal liver tissue except for the hepatoma. Another patient with hepatoma who had a severely depressed receptor population, 1.2 +- 0.2 x 10/sup -8/ mole, expired one week after the study. Liver biopsy demonstrated practically no normal tissue. Thus, by means of a complementary, receptor radiopharmaceutical and mathematical model, one should be able to quantitatively follow hepatocyte function and predict response to a therapeutic regimen.« less

Importance of Temperature Calibration for Sunset Laboratory Carbon Analyzer: NIOSH and IMPROVE Temperature Protocols