Science.gov

Sample records for carbon dioxide responsibility

  1. Herbivore responses to plants grown in enriched carbon dioxide atmospheres

    SciTech Connect

    Lincoln, D.E.

    1990-05-01

    Our initial study of sagebrush and grasshopper responses to elevated and historical carbon dioxide atmospheres is complete and has been accepted for publication. The study on Biomass Allocation Patterns of Defoliated Sagebrush Grown Under Two Levels of Carbon Dioxide has completed and the manuscript has been submitted for publication. We have completed the study of plant growth under two nutrient and carbon dioxide regimes and grasshopper feeding responses. The study of a specialist feeding caterpillar, the cabbage butterfly, and a mustard hostplant has recently been completed. We were able to identify the principal allelochemicals of the mustard plants, butenyl and pentenyl isothiocyanates, by combined gas chromatography and mass spectrometry. Measurement of these chemicals has been a critical component of this study since these compounds contain nitrogen and sulphur and act as a feeding stimulant to the caterpillar. This insect responds to elevated carbon dioxide by consuming more leaves and we can now say that this is not due to a change in the feeding stimulants. Reduced leaf protein content is a critical factor for even specialist feeding insect herbivores under elevated carbon dioxide conditions. The study on Grasshopper Population Responses to Enriched Carbon Dioxide Concentration is currently in progress at the Duke University Phytotron. We have changed hostplant species in order to complement the investigations of carbon dioxide effects on tallgrass prairie. Specifically, we are using big bluestem, Andropogon geradii, as the host plant to feed to the grasshoppers. This experiment will be completed in July 1990.

  2. Vegetation Response to Carbon Dioxide and Climate: Data from the Carbon Dioxide Information Analysis Center (CDIAC)

    DOE Data Explorer

    CDIAC products are indexed and searchable through a customized interface powered by ORNL's Mercury search engine. Products include numeric data packages, publications, trend data, atlases, and models and can be searched for by subject area, keywords, authors, product numbers, time periods, collection sites, spatial references, etc. Some of the collections may also be included in the CDIAC publication Trends Online: A Compendium of Global Change Data. Most data sets, many with numerous data files, are free to download from CDIAC's ftp area. Information related to vegetation response to carbon dioxide and climate includes: • Area and Carbon Content of Sphagnum Since Last Glacial Maximum (2002) (Trends Online) • TDE Model Intercomparison Project Data Archive • Presentations and abstracts from the recent DOE Terrestrial Science Team Meeting (Argonne National Laboratory, October 29-31, 2001) • FACE (Free-Air CO2 Enrichment) • Walker Branch Throughfall Displacement Experiment Data Report: Site Characterization, System Performance, Weather, Species Composition, and Growth (2001) • Bibliography on CO2 Effects on Vegetation and Ecosystems: 1990-1999 Literature (2000) • Direct effects of atmospheric CO2 enrichment on plants and ecosystems: An updated bibliographic data base (1994) • A Database of Herbaceous Vegetation Responses to Elevated Atmospheric CO2 (1999) • A Database of Woody Vegetation Responses to Elevated Atmospheric CO2 (1999) • Forest Responses to Anthropogenic Stress (FORAST) Database (1995) • Effects of CO2 and Nitrogen Fertilization on Growth and Nutrient Content of Juvenile Ponderosa Pine (1998) • Carbon Dioxide Enrichment: Data on the Response of Cotton to Varying CO2Irrigation, and Nitrogen (1992) • Growth and Chemical Responses to CO2 Enrichment Virginia Pine Pinus Virginiana Mill.(1985)

  3. [Effect of diaphragmatic fatigue on ventilatory response to carbon dioxide].

    PubMed

    Wakai, Y; Yoshimura, A; Katagiri, S; Yoshino, K; Konno, K

    1992-12-01

    To clarify the effect of respiratory muscle fatigue on ventilatory response to carbon dioxide, we performed CO2 rebreathing study before and after diaphragmatic fatigue in nine healthy males. Diaphragmatic fatigue was induced by inspiratory resistor loading and confirmed by the increase in Tension Time Index and the decrease in Pdi max at FRC. The effects of diaphragmatic fatigue were as follows: 1) S and B value of VE-CO2 curve did not change. 2) P1-CO2 curve shifted to the left but the slope of the curve did not change. 3) delta Ppl response to CO2 decreased, but delta Pdi response to CO2 did not change. 4) The increase in respiratory accessory muscle EMG was more prominent, compared to diaphragmatic EMG. 5) Rib cage movement became more marked. In conclusion, diaphragmatic fatigue (with 60 percent decrease in Pdi max at FRC) does not affect on ventilatory response to carbon dioxide. To maintain the homeostasis of the chemical ventilatory feedback system, diaphragmatic dysfunction is compensated by the increased activity of respiratory accessory muscles with possible increase in neural drive. PMID:1306216

  4. Microbial Response to Carbon Dioxide Injection in a Shallow Aquifer

    NASA Astrophysics Data System (ADS)

    Rook, A.; Faehndrich, D.; O'Mullan, G.; Mailloux, B.; Matter, J.; Stute, M.; Goldberg, D.

    2007-12-01

    Extensive research is underway to investigate the geophysical and geochemical dynamics of subsurface carbon sequestration, but there has been only theoretical consideration of the microbial response. Microbial dynamics are capable of altering the range and rates of geochemical reactions in the subsurface. The goal of this field experiment is to link geochemical changes due to CO2 injection to alterations in the microbial community and to provide an initial characterization of the microbial response. A seven week push-pull experiment was conducted at the Lamont-Doherty Earth Observatory Test Well. 200L of groundwater was extracted, bubbled with carbon dioxide, augmented with a bromide tracer, and injected to 230m depth below ground surface. The hydraulically isolated injection zone marked the contact area between dolerite sill and sedimentary rock. Samples were taken on a weekly basis. Geochemically, a drop in pH from 9.4 to 4.5 at injection was coupled with a release of Fe2+ from the formation. As neutralization and mixing caused pH to return toward background levels, Fe2+ concentrations decreased. The aquifer remained anoxic throughout the experiment. DNA was successfully extracted and the gene encoding 16S ribosomal RNA was amplified from all samples with the exception of the injection fluid. Sequencing from clone libraries and tRFLP analyses were used to characterize microbial dynamics during the seven week study. Whereas the number of microbial groups detected remained relatively constant over the course of the experiment, changes were observed in both the dominant microbes phylogenetic identity and relative abundance. Methane concentrations increased from background levels (below 50 nM) to 4.2 nM after injection, but initial attempts to amplify archaeal and methanogen-specific genes were unsuccessful, bringing into question the presence of a significant methanogenic population. These results confirm that there is a microbial response to carbon dioxide

  5. [Plant responses to elevated atmospheric carbon dioxide and transmission to other trophic levels]. Final report

    SciTech Connect

    Lincoln, D.E.

    1995-10-01

    This program investigated how host plant responses to elevated atmospheric carbon dioxide may be transmitted to other trophic levels, especially leaf eating insects, and alter consumption of leaves and impare their function. Study results included the following findings: increased carbon dioxide to plants alters feeding by insect herbivores; leaves produced under higher carbon conditions contain proportionally less nitrogen; insect herbivores may have decreased reproduction under elevated carbon dioxide.

  6. Responses of flowering time to elevated carbon dioxide among soybean photoperiod isolines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous work indicated that changes in the phenology of flowering in soybeans caused by long-term growth at elevated carbon dioxide may be important to the responses of seed yield to elevated carbon dioxide. In this study we utilized near-isogenic lines of soybeans differing in three genes influen...

  7. Responses of Tree Seedlings to a Changing Atmosphere: Effects of Carbon Dioxide, Nitrogen Dioxide, and Ozone

    NASA Astrophysics Data System (ADS)

    Eller, A. S.; Sparks, J. P.

    2008-12-01

    Human activities have caused changes in the chemical composition of the atmosphere: the concentrations of carbon dioxide (CO2), nitrogen dioxide (NO2), and ozone (O3) have increased and are expected to continue increasing in the future. These gases have the potential to alter plant physiological processes, change growth rates, C:N, and carbon storage potential. The responses of tree seedlings to these changes will have a profound impact on the species composition and carbon storage potential of forests in the future. Others have found CO2 tends to increase plant growth and O3 to decrease it. NO2, if assimilated by plants, can be a source of nutrient nitrogen, but is also an oxidant with the potential to damage cell membranes and decrease growth. The objectives of this study were to determine the single and combined effects of CO2, NO2, and O3 on sugar maple, eastern hemlock, and two clones of trembling aspen. The trees were fumigated for two growing seasons with elevated (40ppb) or ambient NO2, elevated (560ppm) or ambient CO2, elevated (100 ppb 5 days/week) or ambient O3, and with or without additional soil nitrate (30 kg ha-1 yr-1) to simulate ecosystems with and without nitrogen limitation. We found that elevated CO2 increased total biomass of both maples and hemlocks. Further, the CO2 growth effect was most striking when combined with elevated O2; elevated CO2 eliminated the growth decrease induced by O3 especially when nitrogen was limited. Elevated NO2 had no effect on maple seedlings, but, similar to CO2, eliminated the decrease in growth under O3 on hemlock seedlings. The two aspen clones differed in their resistance to ozone. The non-resistant clone exhibited growth responses similar to maple. However, the resistant clone did not exhibit a growth response under any gas treatment regardless of soil nitrogen status. The variation in responses among species, within clones of the same species, and between fumigations was large in this study and suggests

  8. Taxon-specific response of marine nitrogen fixers to elevated carbon dioxide concentrations

    NASA Astrophysics Data System (ADS)

    Hutchins, David A.; Fu, Fei-Xue; Webb, Eric A.; Walworth, Nathan; Tagliabue, Alessandro

    2013-09-01

    Much of the bioavailable nitrogen that supports open ocean food webs and biogeochemical cycles is fixed from the atmosphere by marine cyanobacteria of the genera Trichodesmium and Crocosphaera. In previous experiments carried out with a limited set of cyanobacterial isolates, rates of cyanobacterial nitrogen fixation were shown to increase with carbon dioxide concentrations. Here, we report results from a series of laboratory experiments in which we grew seven strains of Trichodesmium and Crocosphaera from the Atlantic and Pacific oceans under a wide range of carbon dioxide concentrations, and monitored rates of nitrogen fixation and growth. We document large, strain-specific differences in the relationship between nitrogen fixation and carbon dioxide concentration, suggesting that individual strains within each genus are adapted to grow and fix nitrogen at different concentrations of carbon dioxide. We apply kinetic constants from the individual carbon dioxide response curves to an illustrative biogeochemical model of the ocean in 2100, which suggests that strains adapted to high carbon dioxide concentrations could potentially be favoured in a future acidified ocean. We suggest that surface ocean carbon dioxide concentrations could constitute a previously unrecognized selective force that shapes the community composition and diversity of nitrogen-fixing cyanobacteria.

  9. Late Miocene threshold response of marine algae to carbon dioxide limitation.

    PubMed

    Bolton, Clara T; Stoll, Heather M

    2013-08-29

    Coccolithophores are marine algae that use carbon for calcification and photosynthesis. The long-term adaptation of these and other marine algae to decreasing carbon dioxide levels during the Cenozoic era has resulted in modern algae capable of actively enhancing carbon dioxide at the site of photosynthesis. This enhancement occurs through the transport of dissolved bicarbonate (HCO3(-)) and with the help of enzymes whose expression can be modulated by variable aqueous carbon dioxide concentration, [CO2], in laboratory cultures. Coccolithophores preserve the geological history of this adaptation because the stable carbon and oxygen isotopic compositions of their calcite plates (coccoliths), which are preserved in the fossil record, are sensitive to active carbon uptake and transport by the cell. Here we use a model of cellular carbon fluxes and show that at low [CO2] the increased demand for HCO3(-) at the site of photosynthesis results in a diminished allocation of HCO3(-) to calcification, which is most pronounced in larger cells. This results in a large divergence between the carbon isotopic compositions of small versus large coccoliths only at low [CO2]. Our evaluation of the oxygen and carbon isotope record of size-separated fossil coccoliths reveals that this isotopic divergence first arose during the late Miocene to the earliest Pliocene epoch (about 7-5 million years ago). We interpret this to be a threshold response of the cells' carbon acquisition strategies to decreasing [CO2]. The documented coccolithophore response is synchronous with a global shift in terrestrial vegetation distribution between 8 and 5 Myr ago, which has been interpreted by some studies as a floral response to decreasing partial pressures of carbon dioxide () in the atmosphere. We infer a global decrease in carbon dioxide levels for this time interval that has not yet been identified in the sparse proxy record but is synchronous with global cooling and progressive glaciations.

  10. Modeling forest ecosystem responses to elevated carbon dioxide and ozone using artificial neural networks.

    PubMed

    Larsen, Peter E; Cseke, Leland J; Miller, R Michael; Collart, Frank R

    2014-10-21

    Rising atmospheric levels of carbon dioxide and ozone will impact productivity and carbon sequestration in forest ecosystems. The scale of this process and the potential economic consequences provide an incentive for the development of models to predict the types and rates of ecosystem responses and feedbacks that result from and influence of climate change. In this paper, we use phenotypic and molecular data derived from the Aspen Free Air CO2 Enrichment site (Aspen-FACE) to evaluate modeling approaches for ecosystem responses to changing conditions. At FACE, it was observed that different aspen clones exhibit clone-specific responses to elevated atmospheric levels of carbon dioxide and ozone. To identify the molecular basis for these observations, we used artificial neural networks (ANN) to examine above and below-ground community phenotype responses to elevated carbon dioxide, elevated ozone and gene expression profiles. The aspen community models generated using this approach identified specific genes and subnetworks of genes associated with variable sensitivities for aspen clones. The ANN model also predicts specific co-regulated gene clusters associated with differential sensitivity to elevated carbon dioxide and ozone in aspen species. The results suggest ANN is an effective approach to predict relevant gene expression changes resulting from environmental perturbation and provides useful information for the rational design of future biological experiments.

  11. CO/sub 2/ and plants: The response of plants to rising levels of atmospheric carbon dioxide

    SciTech Connect

    Lemon, E.R.

    1983-01-01

    This book contains papers on the biological effects of carbon dioxide on vegetation. Topics considered include physiological responses, climatology, carbon metabolism, carbon dioxide fixation, substrates, photosynthesis, plant growth and development, plant dynamics, microbial effects, terrestrial plant communities, and aquatic plant communities.

  12. Trade, transport, and sinks extend the carbon dioxide responsibility of countries: An editorial essay

    SciTech Connect

    Peters, Glen P; Marland, Gregg; Hertwich, Edgar G.; Saikku, Laura

    2009-01-01

    Globalization and the dynamics of ecosystem sinks need be considered in post-Kyoto climate negotiations as they increasingly affect the carbon dioxide concentration in the atmosphere. Currently, the allocation of responsibility for greenhouse gas mitigation is based on territorial emissions from fossil-fuel combustion, process emissions and some land-use emissions. However, at least three additional factors can significantly alter a country's impact on climate from carbon dioxide emissions. First, international trade causes a separation of consumption from production, reducing domestic pollution at the expense of foreign producers, or vice versa. Second, international transportation emissions are not allocated to countries for the purpose of mitigation. Third, forest growth absorbs carbon dioxide and can contribute to both carbon sequestration and climate change protection. Here we quantify how these three factors change the carbon dioxide emissions allocated to China, Japan, Russia, USA, and European Union member countries. We show that international trade can change the carbon dioxide currently allocated to countries by up to 60% and that forest expansion can turn some countries into net carbon sinks. These factors are expected to become more dominant as fossil-fuel combustion and process emissions are mitigated and as international trade and forest sinks continue to grow. Emission inventories currently in wide-spread use help to understand the global carbon cycle, but for long-term climate change mitigation a deeper understanding of the interaction between the carbon cycle and society is needed. Restructuring international trade and investment flows to meet environmental objectives, together with the inclusion of forest sinks, are crucial issues that need consideration in the design of future climate policies. And even these additional issues do not capture the full impact of changes in the carbon cycle on the global climate system.

  13. Coral reefs and carbon dioxide

    SciTech Connect

    Buddemeier, R.W.

    1996-03-01

    This commentary argues the conclusion from a previous article, which investigates diurnal changes in carbon dioxide partial pressure and community metabolism on coral reefs, that coral `reefs might serve as a sink, not a source, for atmospheric carbon dioxide.` Commentaries from two groups are given along with the response by the original authors, Kayanne et al. 27 refs.

  14. Responses of cotton and wheat photosynthesis and growth to cyclic variation in carbon dioxide concentration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The carbon dioxide concentration in free air carbon dioxide enrichment systems (FACE) often has rapid fluctuations. In our FACE system, power spectral analysis of carbon dioxide concentrations measured every second with an open path analyzer indicated peaks in variation centered on a wavelength of ...

  15. Carbon dioxide concentrator

    NASA Technical Reports Server (NTRS)

    Williams, C. F.; Huebscher, R. G.

    1972-01-01

    Passed exhaled air through electrochemical cell containing alkali metal carbonate aqueous solution, and utilizes platinized electrodes causing reaction of oxygen at cathode with water in electrolyte, producing hydroxyl ions which react with carbon dioxide to form carbonate ions.

  16. The carbon dioxide cycle

    USGS Publications Warehouse

    James, P.B.; Hansen, G.B.; Titus, T.N.

    2005-01-01

    The seasonal CO2 cycle on Mars refers to the exchange of carbon dioxide between dry ice in the seasonal polar caps and gaseous carbon dioxide in the atmosphere. This review focuses on breakthroughs in understanding the process involving seasonal carbon dioxide phase changes that have occurred as a result of observations by Mars Global Surveyor. ?? 2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

  17. Microbial resuscitation following soil wet-up: who is responsible for the carbon dioxide pulse?

    NASA Astrophysics Data System (ADS)

    Placella, S.; Brodie, E. L.; Firestone, M. K.

    2011-12-01

    The first rainfall following a long dry period in arid and semi-arid ecosystems results in a large carbon dioxide pulse concurrent with the resuscitation of soil microbial communities rendered inactive by the preceding dry conditions. We compared the rate of carbon dioxide produced over time to the responses of the component populations of the indigenous microbial communities during wet-up of soils taken from two California annual grasslands following a typically dry Mediterranean summer. The rate of carbon dioxide production increased rapidly, peaking at 1 hour after water addition in both soils, and remained elevated for 3 days. Differential resuscitation of bacterial groups was evident within 1 hour of wet-up using high-density microarray (PhyloChip) analysis of 16S rRNA. We identified three response strategies of groups within the microbial community based on when taxa had the highest relative ribosomal RNA quantity: rapid-responders (within 1 hour of wet-up), intermediate-responders (between 3 and 24 hours following wet-up), and delayed-responders (24 to 72 hours post wet-up). These data suggest that the large carbon dioxide pulse produced in response to wet-up results from the aggregate activity of different groups of soil microorganisms up-regulating over time. Relative ribosomal quantityies of the "rapidly responding" group was as high in the prewet soils (dry) as at any other time, suggesting that some organisms are poised to respond to the wet-up event; that is, they preserve their capacity to rapidly synthesize proteins during the dry summer months. Microbial response patterns clustered phylogenetically, and were primarily conserved at the phylum level, with the clustering of responses consistent across the two soils. The microbial communities indigenous to the semi-arid soils examined appear to be highly adapted to the extended, extreme drought characteristic of the Mediterranean climate as well as to the rainfall "shock" at the end of the dry period.

  18. Reducing ventilatory response to carbon dioxide by breathing cold air.

    PubMed

    Burgess, K R; Whitelaw, W A

    1984-05-01

    To study the effect of cooling of nasal receptors on breathing we had 10 normal male volunteers rebreathe through their noses 8% CO2 in oxygen at "warm" (23 to 30 degrees C) and at "cold" (-4 to 10 degrees C) temperatures. In order to further examine the effect of nasal receptors on the control of breathing, 11 subjects had their nasal response to CO2 measured at the warm temperature before and after topical nasal anesthesia. To exclude an increase in nasal resistance as the cause of the reduced response to CO2, 10 subjects had their nasal resistance measured before and after nasal rebreathing of cold 8% CO2 in oxygen. To also exclude increased bronchial resistance, forced expiratory volume in one second (FEV1) was measured in 12 subjects before and after nasal breathing of cold oxygen for 3 min. The mean ventilatory response to CO2 was reduced from 3.0 +/- 1.6 L/min/mmHg to 2.5 +/- 1.1 L/min/mmHg (p less than 0.05) by the cold air. Topical nasal anesthesia increased the response to CO2 at the warm temperature from 2.4 +/- 0.7 to 2.7 +/- 0.9 L/min/mmHg. The effect of nasal breathing of 8% CO2 in oxygen at the cold temperature was to reduce nasal inspiratory resistance at 1 L/s from 4.3 +/- 3.0 cm H2O L/s to 2.6 +/- 1.0 cm H2O L/s (p less than 0.05). Expiratory resistance at 1 L/s fell from 3.7 +/- 1.5 cm H2O L/s to 2.4 +/- 0.7 cm H2O L/s (p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Cerebral blood flow response to changes in arterial carbon dioxide tension during hypothermic cardiopulmonary bypass in children

    SciTech Connect

    Kern, F.H.; Ungerleider, R.M.; Quill, T.J.; Baldwin, B.; White, W.D.; Reves, J.G.; Greeley, W.J. )

    1991-04-01

    We examined the relationship of changes in partial pressure of carbon dioxide on cerebral blood flow responsiveness in 20 pediatric patients undergoing hypothermic cardiopulmonary bypass. Cerebral blood flow was measured during steady-state hypothermic cardiopulmonary bypass with the use of xenon 133 clearance methodology at two different arterial carbon dioxide tensions. During these measurements there was no significant change in mean arterial pressure, nasopharyngeal temperature, pump flow rate, or hematocrit value. Cerebral blood flow was found to be significantly greater at higher arterial carbon dioxide tensions (p less than 0.01), so that for every millimeter of mercury rise in arterial carbon dioxide tension there was a 1.2 ml.100 gm-1.min-1 increase in cerebral blood flow. Two factors, deep hypothermia (18 degrees to 22 degrees C) and reduced age (less than 1 year), diminished the effect carbon dioxide had on cerebral blood flow responsiveness but did not eliminate it. We conclude that cerebral blood flow remains responsive to changes in arterial carbon dioxide tension during hypothermic cardiopulmonary bypass in infants and children; that is, increasing arterial carbon dioxide tension will independently increase cerebral blood flow.

  20. Naloxone application to the ventrolateral medulla enhances the respiratory response to inspired carbon dioxide

    SciTech Connect

    Trouth, C.O.; Bada, F.J.; Pan, Yi; Holloway, J.A.; Millis, R.M.; Bernard, D.G. )

    1991-01-01

    Previous studies have shown that systemic administration of the opiate antagonist naloxone potentiates the ventilatory response to inspired carbon dioxide. The present study was designed to localize the site of action of naloxone for increasing the respiratory chemosensitivity to inhaled carbon dioxide (CO{sub 2}) in cats. Naloxone applied topically to the caudal chemosensitive area on the ventral medullary surface (VMS) during hypercapnic breathing produced a 75% greater increase in minute ventilation than hypercapnic breathing alone. Furthermore, hypercapnic breathing produced a 200% increase in neuronal activity of VMS chemosensitive cells; this was further increased 120% by naloxone. It is concluded that naloxone increases the sensitivity of neurons in the caudal respiratory chemosensitive area of cats to hypercapnia, and that endogenous opiates may act as modulators at VMS chemosensitive sites during hypercapnic breathing.

  1. Dynamic response characteristics of the potentiometric carbon dioxide sensor for the determination of aspartame.

    PubMed

    Nikolelis, D P; Krull, U J

    1990-07-01

    The dynamic response characteristics of a carbon dioxide gas sensor were studied to determine the potential for application of the device to the kinetic assay of substrate(s) under pseudo first-order kinetics. The dependence of the time constant on the concentration of carbon dioxide was determined by using convolution mathematics to analyse potentiometric changes caused by abrupt alterations of gas concentration. The operational conditions of the CO2 sensor were optimised for the development of enzyme electrodes, so that the mass-transport phenomena occurring during the course of the enzymic reactions were enhanced. As a result, the kinetic analysis of substrate(s) was performed more rapidly (2-6 min), with greater sensitivity and with an improved detection limit (10-5 M). A kinetic reaction-rate method for the determination of aspartame in dietary foodstuffs is proposed as a rapid and inexpensive alternative to a classical high-performance liquid chromatographic method.

  2. Carbon Dioxide and Climate.

    ERIC Educational Resources Information Center

    Brewer, Peter G.

    1978-01-01

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

  3. Carbon Dioxide Fountain

    ERIC Educational Resources Information Center

    Kang, Seong-Joo; Ryu, Eun-Hee

    2007-01-01

    This article presents the development of a carbon dioxide fountain. The advantages of the carbon dioxide fountain are that it is odorless and uses consumer chemicals. This experiment also is a nice visual experiment that allows students to see evidence of a gaseous reagent being consumed when a pressure sensor is available. (Contains 3 figures.)…

  4. Response of vegetation to carbon dioxide. Field studies of plant responses to elevated carbon dioxide levels 1984

    SciTech Connect

    1998-08-01

    In the present study, CO{sub 2} enrichment has been applied to sweet potatoes and cowpeas in order to investigate its effect on their growth, physiology, and yield under field condition. Objectives were: (1) to establish at Tuskegee Institute the facilities for growing crops in the field under enriched CO{sub 2} atmospheric conditions; (2) to obtain field data on the morphological, physiological, biochemical, growth and yield responses of sweet potatoes and cowpeas to elevated levels of CO{sub 2}; (3) to determine the effects of elevated CO{sub 2} in the rate of nitrogen fixation of cowpeas; (4) to provide data for a generalized crop growth model for predicting yield of both sweet potatoes and cowpeas as a function of atmospheric CO{sub 2} enrichment.

  5. Carbon dioxide and climate

    SciTech Connect

    Not Available

    1990-10-01

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

  6. Dynamic responses of atmospheric carbon dioxide concentration to global temperature changes between 1850 and 2010

    NASA Astrophysics Data System (ADS)

    Wang, Weile; Nemani, Ramakrishna

    2016-02-01

    Changes in Earth's temperature have significant impacts on the global carbon cycle that vary at different time scales, yet to quantify such impacts with a simple scheme is traditionally deemed difficult. Here, we show that, by incorporating a temperature sensitivity parameter (1.64 ppm yr-1 °C-1) into a simple linear carbon-cycle model, we can accurately characterize the dynamic responses of atmospheric carbon dioxide (CO2) concentration to anthropogenic carbon emissions and global temperature changes between 1850 and 2010 ( r 2 > 0.96 and the root-mean-square error < 1 ppm for the period from 1960 onward). Analytical analysis also indicates that the multiplication of the parameter with the response time of the atmospheric carbon reservoir (~12 year) approximates the long-term temperature sensitivity of global atmospheric CO2 concentration (~15 ppm °C-1), generally consistent with previous estimates based on reconstructed CO2 and climate records over the Little Ice Age. Our results suggest that recent increases in global surface temperatures, which accelerate the release of carbon from the surface reservoirs into the atmosphere, have partially offset surface carbon uptakes enhanced by the elevated atmospheric CO2 concentration and slowed the net rate of atmospheric CO2 sequestration by global land and oceans by ~30% since the 1960s. The linear modeling framework outlined in this paper thus provides a useful tool to diagnose the observed atmospheric CO2 dynamics and monitor their future changes.

  7. [Plant responses to elevated atmospheric carbon dioxide and transmission to other trophic levels]. Progress report, May 1991, DOE Grant DE-FG09-84ER60255

    SciTech Connect

    Lincoln, D.E.

    1991-05-01

    Experiments were performed to determine the effects of carbon dioxide on plants and on the insects feeding on these plants. Current progress is reported for the following experiments: Response of a Specialist-Feeding Insect Herbivore to Carbon Dioxide Induced Changes in Its Hostplant; Growth and Reproduction of Grasshoppers Feeding on a C{sub 4} Grass Under Elevated Carbon Dioxide; Elevated Carbon Dioxide and Temperature Effects on Growth and Defense of Big Sagebrush; Sagebrush and Grasshopper Responses to Atmospheric Carbon Dioxide Concentration; Biomass Allocation Patterns of Defoliated Sagebrush Grown Under Two Levels of Carbon Dioxide; and Sagebrush Carbon Allocation Patterns and Grasshopper Nutrition: The Influence of Carbon Dioxide Enrichment and Soil Mineral Limitation.

  8. Carbon dioxide removal process

    DOEpatents

    Baker, Richard W.; Da Costa, Andre R.; Lokhandwala, Kaaeid A.

    2003-11-18

    A process and apparatus for separating carbon dioxide from gas, especially natural gas, that also contains C.sub.3+ hydrocarbons. The invention uses two or three membrane separation steps, optionally in conjunction with cooling/condensation under pressure, to yield a lighter, sweeter product natural gas stream, and/or a carbon dioxide stream of reinjection quality and/or a natural gas liquids (NGL) stream.

  9. Anxiety sensitivity and trait anxiety are associated with response to 7.5% carbon dioxide challenge.

    PubMed

    Fluharty, Meg E; Attwood, Angela S; Munafò, Marcus R

    2016-02-01

    The 7.5% carbon dioxide (CO2) inhalation model is used to provoke acute anxiety, for example to investigate the effects of anxiety on cognitive processes, or the efficacy of novel anxiolytic agents. However, little is known about the relationship of baseline anxiety sensitivity or trait anxiety (i.e., anxiety proneness), with an individual's response to the 7.5% CO2 challenge. We examined data from a number of 7.5% CO2 challenge studies to determine whether anxiety proneness was related to subjective or physiological response. Our findings indicate anxiety proneness is associated with greater subjective and physiological responses. However, anxiety-prone individuals also have a greater subjective response to the placebo (medical air) condition. This suggests that anxiety-prone individuals not only respond more strongly to the 7.5% CO2 challenge, but also to medical air. Implications for the design and conduct of 7.5% CO2 challenge studies are discussed.

  10. Environmental carbon dioxide control

    NASA Technical Reports Server (NTRS)

    Onischak, M.; Baker, B.; Gidaspow, D.

    1974-01-01

    A study of environmental carbon dioxide control for NASA EVA missions found solid potassium carbonate to be an effective regenerable absorbent in maintaining low carbon dioxide levels. The supported sorbent was capable of repeated regeneration below 150 C without appreciable degradation. Optimum structures in the form of thin pliable sheets of carbonate, inert support and binder were developed. Interpretation of a new solid-gas pore closing model helped predict the optimum sorbent and analysis of individual sorbent sheet performance in a thin rectangular channel sorber can predict packed bed performance.

  11. Carbon dioxide sensor

    DOEpatents

    Dutta, Prabir K.; Lee, Inhee; Akbar, Sheikh A.

    2011-11-15

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

  12. Carbon dioxide recycling

    EPA Science Inventory

    The recycling of carbon dioxide to methanol and dimethyl ether is seen to offer a substantial route to renewable and environmentally carbon neutral fuels. One of the authors has championed the “Methanol Economy" in articles and a book. By recycling ambient CO2, the authors argue ...

  13. Growth and physiological responses of creeping bentgrass (Agrostis stolonifera) to elevated carbon dioxide concentrations.

    PubMed

    Burgess, Patrick; Huang, Bingru

    2014-01-01

    The atmospheric carbon dioxide level has increased and is predicted to continue increasing, which may affect various aspects of plant growth. The objective of this study was to investigate the effects of doubling the carbon dioxide level on the growth and physiological activities of a widely utilized cool-season turfgrass species, creeping bentgrass (Agrostis stolonifera L. 'Penncross'). 'Penncross' plants were established in fritted clay medium and maintained under well-irrigated and well-fertilized conditions in growth chambers. The plants were exposed to either ambient carbon dioxide concentrations (400±10 µmol L(-1)) or elevated carbon dioxide concentrations (800±10 µmol L(-1)) for 12 weeks. Plants grown under elevated carbon dioxide displayed a significantly faster growth rate of their lateral stems (stolons) and increased shoot and root dry weight but a reduced specific leaf area compared to those plants at ambient carbon dioxide levels. Fast stolon growth is a highly desirable trait for turfgrass establishment and recovery from physical damage. The root length and surface area were also increased due to the elevated CO2, which may facilitate water uptake and serve critical drought-avoidance roles when irrigation water is limited. Elevated carbon dioxide caused an increase in the leaf net photosynthetic rate but a reduction in the stomatal conductance and transpiration rate, contributing to improved water use efficiency in creeping bentgrass. Efficient water use is especially important for turfgrass plant survival when irrigation water is limited. Our results suggested that cool-season turfgrass species may greatly benefit from increasingly elevated carbon dioxide concentrations via growth promotion and increasing water use efficiency.

  14. Growth and physiological responses of creeping bentgrass (Agrostis stolonifera) to elevated carbon dioxide concentrations

    PubMed Central

    Burgess, Patrick; Huang, Bingru

    2014-01-01

    The atmospheric carbon dioxide level has increased and is predicted to continue increasing, which may affect various aspects of plant growth. The objective of this study was to investigate the effects of doubling the carbon dioxide level on the growth and physiological activities of a widely utilized cool-season turfgrass species, creeping bentgrass (Agrostis stolonifera L. ‘Penncross’). ‘Penncross’ plants were established in fritted clay medium and maintained under well-irrigated and well-fertilized conditions in growth chambers. The plants were exposed to either ambient carbon dioxide concentrations (400±10 µmol L−1) or elevated carbon dioxide concentrations (800±10 µmol L−1) for 12 weeks. Plants grown under elevated carbon dioxide displayed a significantly faster growth rate of their lateral stems (stolons) and increased shoot and root dry weight but a reduced specific leaf area compared to those plants at ambient carbon dioxide levels. Fast stolon growth is a highly desirable trait for turfgrass establishment and recovery from physical damage. The root length and surface area were also increased due to the elevated CO2, which may facilitate water uptake and serve critical drought-avoidance roles when irrigation water is limited. Elevated carbon dioxide caused an increase in the leaf net photosynthetic rate but a reduction in the stomatal conductance and transpiration rate, contributing to improved water use efficiency in creeping bentgrass. Efficient water use is especially important for turfgrass plant survival when irrigation water is limited. Our results suggested that cool-season turfgrass species may greatly benefit from increasingly elevated carbon dioxide concentrations via growth promotion and increasing water use efficiency. PMID:26504537

  15. Polymeric Carbon Dioxide

    SciTech Connect

    Yoo, C-S.

    1999-11-02

    Synthesis of polymeric carbon dioxide has long been of interest to many chemists and materials scientists. Very recently we discovered the polymeric phase of carbon dioxide (called CO{sub 2}-V) at high pressures and temperatures. Our optical and x-ray results indicate that CO{sub 2}-V is optically non-linear, generating the second harmonic of Nd: YLF laser at 527 nm and is also likely superhard similar to cubic-boron nitride or diamond. CO{sub 2}-V is made of CO{sub 4} tetrahedra, analogous to SiO{sub 2} polymorphs, and is quenchable at ambient temperature at pressures above 1 GPa. In this paper, we describe the pressure-induced polymerization of carbon dioxide together with the stability, structure, and mechanical and optical properties of polymeric CO{sub 2}-V. We also present some implications of polymeric CO{sub 2} for high-pressure chemistry and new materials synthesis.

  16. Physiological and morphological variation in response to elevated atmospheric carbon dioxide in two populations of Plantago lanceolata

    SciTech Connect

    Klus, D.J.; Kalisz, S.; Tonsor, S.J. )

    1993-06-01

    An experiment was conducted at the Duke University Phytotron to determine the nature and extent of genetic variation in response to elevated levels of atmospheric carbon dioxide in 44 families from two populations of Plantago lanceolata. 10 seedlings from each maternal family were divided equally between ambient and elevated greenhouses and were grown for 60 days. At the end of that period measurements of assimilation and transpiration were made, the plants were harvested and seven morphological traits were measured. Analysis of the data reveals that genetic variation in response to elevated carbon dioxide exists at the family level for assimilation, and at the population level for three of the morphological traits: number of vegetative shoots per plant, diameter of the vegetative shoots, and number of leaves per shoot. Thus, the potential for elevated carbon dioxide to act as an agent of natural selection exists within this plant species.

  17. Responses of beech and spruce foliage to elevated carbon dioxide, increased nitrogen deposition and soil type.

    PubMed

    Günthardt-Goerg, Madeleine Silvia; Vollenweider, Pierre

    2015-06-19

    Although enhanced carbon fixation by forest trees may contribute significantly to mitigating an increase in atmospheric carbon dioxide (CO2), capacities for this vary greatly among different tree species and locations. This study compared reactions in the foliage of a deciduous and a coniferous tree species (important central European trees, beech and spruce) to an elevated supply of CO2 and evaluated the importance of the soil type and increased nitrogen deposition on foliar nutrient concentrations and cellular stress reactions. During a period of 4 years, beech (represented by trees from four different regions) and spruce saplings (eight regions), planted together on either acidic or calcareous forest soil in the experimental model ecosystem chambers, were exposed to single and combined treatments consisting of elevated carbon dioxide (+CO2, 590 versus 374 μL L(-1)) and elevated wet nitrogen deposition (+ND, 50 versus 5 kg ha(-1) a(-1)). Leaf size and foliage mass of spruce were increased by +CO2 on both soil types, but those of beech by +ND on the calcareous soil only. The magnitude of the effects varied among the tree origins in both species. Moreover, the concentration of secondary compounds (proanthocyanidins) and the leaf mass per area, as a consequence of cell wall thickening, were also increased and formed important carbon sinks within the foliage. Although the species elemental concentrations differed in their response to CO2 fertilization, the +CO2 treatment effect was weakened by an acceleration of cell senescence in both species, as shown by a decrease in photosynthetic pigment and nitrogen concentration, discolouration and stress symptoms at the cell level; the latter were stronger in beech than spruce. Hence, young trees belonging to a species with different ecological niches can show contrasting responses in their foliage size, but similar responses at the cell level, upon exposure to elevated levels of CO2. The soil type and its nutrient supply

  18. Responses of beech and spruce foliage to elevated carbon dioxide, increased nitrogen deposition and soil type.

    PubMed

    Günthardt-Goerg, Madeleine Silvia; Vollenweider, Pierre

    2015-01-01

    Although enhanced carbon fixation by forest trees may contribute significantly to mitigating an increase in atmospheric carbon dioxide (CO2), capacities for this vary greatly among different tree species and locations. This study compared reactions in the foliage of a deciduous and a coniferous tree species (important central European trees, beech and spruce) to an elevated supply of CO2 and evaluated the importance of the soil type and increased nitrogen deposition on foliar nutrient concentrations and cellular stress reactions. During a period of 4 years, beech (represented by trees from four different regions) and spruce saplings (eight regions), planted together on either acidic or calcareous forest soil in the experimental model ecosystem chambers, were exposed to single and combined treatments consisting of elevated carbon dioxide (+CO2, 590 versus 374 μL L(-1)) and elevated wet nitrogen deposition (+ND, 50 versus 5 kg ha(-1) a(-1)). Leaf size and foliage mass of spruce were increased by +CO2 on both soil types, but those of beech by +ND on the calcareous soil only. The magnitude of the effects varied among the tree origins in both species. Moreover, the concentration of secondary compounds (proanthocyanidins) and the leaf mass per area, as a consequence of cell wall thickening, were also increased and formed important carbon sinks within the foliage. Although the species elemental concentrations differed in their response to CO2 fertilization, the +CO2 treatment effect was weakened by an acceleration of cell senescence in both species, as shown by a decrease in photosynthetic pigment and nitrogen concentration, discolouration and stress symptoms at the cell level; the latter were stronger in beech than spruce. Hence, young trees belonging to a species with different ecological niches can show contrasting responses in their foliage size, but similar responses at the cell level, upon exposure to elevated levels of CO2. The soil type and its nutrient supply

  19. Responses of beech and spruce foliage to elevated carbon dioxide, increased nitrogen deposition and soil type

    PubMed Central

    Günthardt-Goerg, Madeleine Silvia; Vollenweider, Pierre

    2015-01-01

    Although enhanced carbon fixation by forest trees may contribute significantly to mitigating an increase in atmospheric carbon dioxide (CO2), capacities for this vary greatly among different tree species and locations. This study compared reactions in the foliage of a deciduous and a coniferous tree species (important central European trees, beech and spruce) to an elevated supply of CO2 and evaluated the importance of the soil type and increased nitrogen deposition on foliar nutrient concentrations and cellular stress reactions. During a period of 4 years, beech (represented by trees from four different regions) and spruce saplings (eight regions), planted together on either acidic or calcareous forest soil in the experimental model ecosystem chambers, were exposed to single and combined treatments consisting of elevated carbon dioxide (+CO2, 590 versus 374 μL L−1) and elevated wet nitrogen deposition (+ND, 50 versus 5 kg ha−1 a−1). Leaf size and foliage mass of spruce were increased by +CO2 on both soil types, but those of beech by +ND on the calcareous soil only. The magnitude of the effects varied among the tree origins in both species. Moreover, the concentration of secondary compounds (proanthocyanidins) and the leaf mass per area, as a consequence of cell wall thickening, were also increased and formed important carbon sinks within the foliage. Although the species elemental concentrations differed in their response to CO2 fertilization, the +CO2 treatment effect was weakened by an acceleration of cell senescence in both species, as shown by a decrease in photosynthetic pigment and nitrogen concentration, discolouration and stress symptoms at the cell level; the latter were stronger in beech than spruce. Hence, young trees belonging to a species with different ecological niches can show contrasting responses in their foliage size, but similar responses at the cell level, upon exposure to elevated levels of CO2. The soil type and its nutrient supply

  20. Bench Remarks: Carbon Dioxide.

    ERIC Educational Resources Information Center

    Bent, Henry A.

    1987-01-01

    Discusses the properties of carbon dioxide in its solid "dry ice" stage. Suggests several demonstrations and experiments that use dry ice to illustrate Avogadro's Law, Boyle's Law, Kinetic-Molecular Theory, and the effects of dry ice in basic solution, in limewater, and in acetone. (TW)

  1. Cultivar specific changes in peanut (Arachis hypogae L.) yield, biomass, and allergenicity in response to elevated atmospheric carbon dioxide concentration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Intraspecific variation in response to rising atmospheric carbon dioxide concentration, [CO2], could, potentially, be used as a means to begin selection for improved quantitative or qualitative characteristics for a given crop. Peanut (Arachis hypogaea L.) is a leguminous crop of global importance;...

  2. A dynamic analysis of the ventilatory response to carbon dioxide inhalation in man.

    PubMed Central

    Bertholon, J F; Carles, J; Eugene, M; Labeyrie, E; Teillac, A

    1988-01-01

    1. The dynamics of the ventilatory response to carbon dioxide inhalation were studied in ten healthy young men using four different inspired fractions of carbon dioxide (FI, CO2) in air (0.015, 0.030, 0.045 and 0.060) successively increasing and decreasing stepwise. 2. Seven such different progressions were performed for each subject and each of seven different durations of the steps (t) ranging between 0.1 (i.e. one ventilatory cycle) and 10 min ('steady-state' conditions). The overall duration of one test (T) was taken as the sum of the seven successive FI, CO2 steps (t) plus one step, t, of air breathing. Thus, the values of T ranged between 0.8 (i.e. eight ventilatory cycles) and 80 min. Three subjects were tested twice. 3. We measured, as a function of T, the magnitude of the loops formed by the curves PA, CO2-VE and the value of the highest ventilatory response (VE max) to each progression. For all ten subjects, both functions had two maxima, one for T values of 2.6 or 8.0 min and one for T values of 24 or 40 min, and one minimum at T equal to 12 min. 4. The same measurements were made on tidal volume-response curves (PA, CO2-VT) and ventilatory frequency-response curves (PA, CO2-f) and yielded the same results except for the ventilatory frequency-response curves, for which we only found a statistically insignificant single maximum for T values of 24 or 40 min. 5. The locations of the maxima in loop magnitude and VE max were similar in duplicate tests in three subjects, whereas the quantitative values of these variables showed wide differences. 6. We compared our results with what is expected from the current linear dynamic model of ventilatory control submitted to the same forcing function: the first maximum in the loop magnitude is predicted by the model, but the second is not. The model shows no peak in the evolution of VE max. 7. We conclude that controlled system dynamics, which are the only ones included in dynamic models of ventilatory control, cannot

  3. Seasonal not annual rainfall determines grassland biomass response to carbon dioxide.

    PubMed

    Hovenden, Mark J; Newton, Paul C D; Wills, Karen E

    2014-07-31

    The rising atmospheric concentration of carbon dioxide (CO2) should stimulate ecosystem productivity, but to what extent is highly uncertain, particularly when combined with changing temperature and precipitation. Ecosystem response to CO2 is complicated by biogeochemical feedbacks but must be understood if carbon storage and associated dampening of climate warming are to be predicted. Feedbacks through the hydrological cycle are particularly important and the physiology is well known; elevated CO2 reduces stomatal conductance and increases plant water use efficiency (the amount of water required to produce a unit of plant dry matter). The CO2 response should consequently be strongest when water is limiting; although this has been shown in some experiments, it is absent from many. Here we show that large annual variation in the stimulation of above-ground biomass by elevated CO2 in a mixed C3/C4 temperate grassland can be predicted accurately using seasonal rainfall totals; summer rainfall had a positive effect but autumn and spring rainfall had negative effects on the CO2 response. Thus, the elevated CO2 effect mainly depended upon the balance between summer and autumn/spring rainfall. This is partly because high rainfall during cool, moist seasons leads to nitrogen limitation, reducing or even preventing biomass stimulation by elevated CO2. Importantly, the prediction held whether plots were warmed by 2 °C or left unwarmed, and was similar for C3 plants and total biomass, allowing us to make a powerful generalization about ecosystem responses to elevated CO2. This new insight is particularly valuable because climate projections predict large changes in the timing of rainfall, even where annual totals remain static. Our findings will help resolve apparent differences in the outcomes of CO2 experiments and improve the formulation and interpretation of models that are insensitive to differences in the seasonal effects of rainfall on the CO2 response.

  4. Increased ventilatory response to carbon dioxide in COPD patients following vitamin C administration

    PubMed Central

    Hartmann, Sara E.; Kissel, Christine K.; Szabo, Lian; Walker, Brandie L.; Leigh, Richard; Anderson, Todd J.

    2015-01-01

    Patients with chronic obstructive pulmonary disease (COPD) have decreased ventilatory and cerebrovascular responses to hypercapnia. Antioxidants increase the ventilatory response to hypercapnia in healthy humans. Cerebral blood flow is an important determinant of carbon dioxide/hydrogen ion concentration at the central chemoreceptors and may be affected by antioxidants. It is unknown whether antioxidants can improve the ventilatory and cerebral blood flow response in individuals in whom these are diminished. Thus, we aimed to determine the effect of vitamin C administration on the ventilatory and cerebrovascular responses to hypercapnia during healthy ageing and in COPD. Using transcranial Doppler ultrasound, we measured the ventilatory and cerebral blood flow responses to hyperoxic hypercapnia before and after an intravenous vitamin C infusion in healthy young (Younger) and older (Older) subjects and in moderate COPD. Vitamin C increased the ventilatory response in COPD patients (mean (95% CI) 1.1 (0.9–1.1) versus 1.5 (1.1–2.0) L·min−1·mmHg−1, p<0.05) but not in Younger (2.5 (1.9–3.1) versus 2.4 (1.9–2.9) L·min−1·mmHg−1, p>0.05) or Older (1.3 (1.0–1.7) versus 1.3 (1.0–1.7) L·min−1·mmHg−1, p>0.05) healthy subjects. Vitamin C did not affect the cerebral blood flow response in the young or older healthy subjects or COPD subjects (p>0.05). Vitamin C increases the ventilatory but not cerebrovascular response to hyperoxic hypercapnia in patients with moderate COPD. PMID:27730137

  5. Carbon dioxide dangers demonstration model

    USGS Publications Warehouse

    Venezky, Dina; Wessells, Stephen

    2010-01-01

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

  6. Response of sugarcane to carbon dioxide enrichment and elevated air temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four sugarcane cultivars (CP 72-2086, CP 73-1547, CP 88-1508, and CP 80-1827) were grown in elongated temperature-gradient greenhouses (TGG) at ambient or elevated carbon dioxide (CO2) of 360 or 720 µmol CO2 mol-1 air (ppm, mole fraction basis), respectively. Elevated CO2 was maintained by injection...

  7. Carbon Dioxide Landscape

    NASA Technical Reports Server (NTRS)

    2005-01-01

    23 July 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a view of some of the widely-varied terrain of the martian south polar residual cap. The landforms here are composed mainly of frozen carbon dioxide. Each year since MGS arrived in 1997, the scarps that bound each butte and mesa, or line the edges of each pit, in the south polar region, have changed a little bit as carbon dioxide is sublimed away. The scarps retreat at a rate of about 3 meters (3 yards) per martian year. Most of the change occurs during each southern summer.

    Location near: 86.7oS, 9.8oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  8. Response of vegetation to carbon dioxide. Growth, yield and plant water relationships in sweet potatoes in response to carbon dioxide enrichment 1986

    SciTech Connect

    1998-08-01

    In the summer of 1985, under the joint program of US Department of Energy, Carbon Dioxide Division, and Tuskegee University, experiments were conducted to study growth, yield, photosynthesis and plant water relationships in sweet potato plants growth in an enriched CO{sub 2} environment. The main experiment utilized open top chambers to study the effects of CO{sub 2} and soil moisture on growth, yield and photosynthesis of field-grown plants. In addition, potted plants in open top chambers were utilized in a study of the effects of different CO{sub 2} concentrations on growth pattern, relative growth rate, net assimilation rate and biomass increment at different stages of development. The interaction effects of enriched CO{sub 2} and water stress on biomass production, yield, xylem potential, and stomatal conductance were also investigated. The overall results of the various studies are described.

  9. CARBON DIOXIDE FIXATION.

    SciTech Connect

    FUJITA,E.

    2000-01-12

    Solar carbon dioxide fixation offers the possibility of a renewable source of chemicals and fuels in the future. Its realization rests on future advances in the efficiency of solar energy collection and development of suitable catalysts for CO{sub 2} conversion. Recent achievements in the efficiency of solar energy conversion and in catalysis suggest that this approach holds a great deal of promise for contributing to future needs for fuels and chemicals.

  10. Frozen Carbon Dioxide

    NASA Technical Reports Server (NTRS)

    2005-01-01

    1 August 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a south polar residual cap landscape, formed in frozen carbon dioxide. There is no place on Earth that one can go to visit a landscape covering thousands of square kilometers with frozen carbon dioxide, so mesas, pits, and other landforms of the martian south polar region are as alien as they are beautiful. The scarps of the south polar region are known from thousands of other MGS MOC images to retreat at a rate of about 3 meters (3 yards) per martian year, indiating that slowly, over the course of the MGS mission, the amount of carbon dioxide in the martian atmosphere has probably been increasing.

    Location near: 86.9oS, 25.5oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  11. Carbon Dioxide Landforms

    NASA Technical Reports Server (NTRS)

    2004-01-01

    19 March 2004 The martian south polar residual ice cap is mostly made of frozen carbon dioxide. There is no place on Earth that a person can go to see the landforms that would be produced by erosion and sublimation of hundreds or thousands of cubic kilometers of carbon dioxide. Thus, the south polar cap of Mars is as alien as alien can get. This image, acquired in February 2004 by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC), shows how the cap appears in summer as carbon dioxide is subliming away, creating a wild pattern of pits, mesas, and buttes. Darker surfaces may be areas where the ice contains impurities, such as dust, or where the surface has been roughened by the removal of ice. This image is located near 86.3oS, 0.8oW. This picture covers an area about 3 km (1.9 mi) across. Sunlight illuminates the scene from the top/upper left.

  12. Mineral elements of subtropical tree seedlings in response to elevated carbon dioxide and nitrogen addition.

    PubMed

    Huang, Wenjuan; Zhou, Guoyi; Liu, Juxiu; Zhang, Deqiang; Liu, Shizhong; Chu, Guowei; Fang, Xiong

    2015-01-01

    Mineral elements in plants have been strongly affected by increased atmospheric carbon dioxide (CO2) concentrations and nitrogen (N) deposition due to human activities. However, such understanding is largely limited to N and phosphorus in grassland. Using open-top chambers, we examined the concentrations of potassium (K), calcium (Ca), magnesium (Mg), aluminum (Al), copper (Cu) and manganese (Mn) in the leaves and roots of the seedlings of five subtropical tree species in response to elevated CO2 (ca. 700 μmol CO2 mol(-1)) and N addition (100 kg N ha(-1) yr(-1)) from 2005 to 2009. These mineral elements in the roots responded more strongly to elevated CO2 and N addition than those in the leaves. Elevated CO2 did not consistently decrease the concentrations of plant mineral elements, with increases in K, Al, Cu and Mn in some tree species. N addition decreased K and had no influence on Cu in the five tree species. Given the shifts in plant mineral elements, Schima superba and Castanopsis hystrix were less responsive to elevated CO2 and N addition alone, respectively. Our results indicate that plant stoichiometry would be altered by increasing CO2 and N deposition, and K would likely become a limiting nutrient under increasing N deposition in subtropics. PMID:25794046

  13. Changes in the carbon dioxide expirogram in response to ozone exposure

    SciTech Connect

    Taylor, Adekemi B.; Lee, Genea M.; Nellore, Kavitha; Ben-Jebria, Abdellaziz . E-mail: axb23@psu.edu; Ultman, James S.

    2006-05-15

    The objectives of this study were to quantify pulmonary responses to ozone (O{sub 3}) exposure by parameters computed from the carbon dioxide expirogram and to compare these responses to decrements in forced expired spirometry. Anatomical dead space (V {sub D}) was determined from the pure dead space and transition regions of the expirogram. Four alternative parameters were computed from the alveolar plateau: slope (S), normalized slope (NS), peripheral cross-sectional area (A {sub P}) and well-mixed peripheral volume (V {sub MP}). Forty-seven healthy nonsmokers (25 men and 22 women) participated in two research sessions in which they exercised on a cycle ergometer for 1 h while orally inhaling either room air at a minute ventilation of 30.6 {+-} 3.6 L or room air mixed with 0.252 {+-} 0.029 ppm O{sub 3} at a minute ventilation of 29.9 {+-} 3.7 L. Carbon dioxide expirograms were measured before exposure, 10 min after exposure and 70 min after exposure. Percent changes (mean {+-} SD) in expirogram parameters were significant (P {<=} 0.002) at both 10 and 70 min after O{sub 3} exposure: V {sub D}(-4.2 {+-} 5.1, -3.3 {+-} 6.9), S(16.4 {+-} 17.9, +15.1 {+-} 20.2), NS(17.5 {+-} 15.4, +15.9 {+-} 19.2), A {sub P}(-8.1 {+-} 7.6, -7.7 {+-} 9.8) and V {sub MP}(-15.4 {+-} 13.0, -13.0 {+-} 15.2). Percent decrements of forced expired volume in one second (FEV{sub 1}) were also significant at both 10 min (-13.3 {+-} 13.4) and 70 min (-11.1 {+-} 9.2) following O{sub 3} exposure. Changes in the expirogram as well as decrements in FEV{sub 1} were not significant at either time point after air exposure. Thus, the CO{sub 2} expirogram is useful for characterizing the effect of O{sub 3} exposure on gas transport, and for supplementing forced expired spirometry that is frequently used to quantify lung mechanics.

  14. Carbon Dioxide Capture and Disposal

    NASA Astrophysics Data System (ADS)

    Lackner, K. S.

    2002-05-01

    Unless carbon dioxide from fossil fuel combustion is captured and disposed of safely and permanently, the concerns over climate change will eventually lead to the demise of fossil fuels. Because of their importance in today's energy market the phasing out of fossil fuels would likely precipitate a major energy crisis. Mineral sequestration and extraction of carbon dioxide from the air are two advanced technologies for carbon sequestration that aim at maintaining access to the vast fossil energy resources for centuries to come. While it is straightforward to dispose of carbon dioxide in limited amounts and for a limited time, permanent disposal of trillions of tons of carbon poses serious challenges. The formation of solid mineral carbonates from readily available minerals would provide safe and permanent storage. Capture of carbon dioxide from air makes it possible to sequester carbon dioxide emissions from sources other than power plants. This is important considering that even the relatively minor reductions suggested by the Kyoto Accord would have required the US to eliminate carbon dioxide emissions comparable to those of the entire 1990 coal fired power plant fleet. Capture of carbon dioxide from the air, would make it possible to close the carbon cycle in the transportation sector without phasing out liquid hydrocarbon fuels. It eliminates the need for long distance transport of carbon dioxide and allows the continued use of the existing energy infrastructure. Mineral sequestration at remote sites combined with on site carbon dioxide capture from air, would allow for long term stabilization of atmospheric carbon dioxide levels. I will outline the current state of the technology and point to advances required before these approaches are ready for large-scale implementation.

  15. Growth and feeding response of Pseudoplusia includens (Lepidoptera:Noctuidae) to host plants grown in controlled carbon dioxide atmospheres

    SciTech Connect

    Lincoln, D.E.; Sionit, N.; Strain, B.R.

    1984-12-01

    Rising atmospheric carbon dioxide may alter plant/herbivore interactions. The projected rise in atmospheric carbon dioxide is expected to increase plant productivity, but little evidence is available regarding effects on insect feeding or growth. Leaves of soybean plants grown under three carbon dioxide regimes (350, 500, and 650 ..mu..l/liter) were fed to soybean looper larvae. Larvae fed at increasingly higher rates on plants from elevated carbon dioxide atmospheres: 80% greater rates on leaves from the 650 ..mu..l/liter treatment than on leaves from the 350 ..mu..l/litter treatment. Variation in larval feeding was related to the leaf content of nitrogen and water and to the leaf-specific weight, each of which was altered by the carbon dioxide growth regime of the soybean plants. This study suggests that the impact of herbivores may increase as the level of atmospheric carbon dioxide rises.

  16. Effects of posture on carbon dioxide responsiveness in patients with obstructive sleep apnoea.

    PubMed Central

    Satoh, M; Hida, W; Chonan, T; Okabe, S; Miki, H; Taguchi, O; Kikuchi, Y; Takishima, T

    1993-01-01

    BACKGROUND--It is well known that upper airway resistance increases with postural change from a sitting to supine position in patients with obstructive sleep apnoea (OSA). It is not known, however, how the postural change affects the ventilatory and occlusion pressure response to hypercapnia in patients with OSA when awake. METHODS--The responses of minute ventilation (VE) and mouth pressure 0.1 seconds after the onset of occluded inspiration (P0.1) to progressive hypercapnia (delta VE/delta PCO2, delta P0.1/delta PCO2) both in sitting and supine positions were measured in 20 patients with OSA. The ratio of the two (delta VE/delta P0.1) was obtained as an index of breathing efficiency. The postural changes in response to carbon dioxide (CO2) after uvulopalatopharyngoplasty (UPPP) were also compared in seven patients with OSA. RESULTS--There were no significant changes in the resting values of end tidal PCO2, P0.1, or VE between the two positions. During CO2 rebreathing, delta VE/delta PCO2 did not differ between the two positions, but delta P0.1/delta PCO2 was significantly higher in the supine than in the sitting position (supine, mean 0.67 (SE 0.09) cm H2O/mm Hg; sitting, mean 0.57 (SE 0.08) cm H2O/mm Hg), and delta VE/delta P0.1 decreased significantly from the sitting to the supine position (sitting, 4.6 (0.4) l/min/cm H2O; supine, 3.9 (0.4) l/min/cm H2O). In seven patients with OSA who underwent UPPP, delta VE/delta P0.1 improved significantly in the supine position and postural change in delta VE/delta P0.1 was eliminated. CONCLUSIONS--These results suggest that in patients with OSA the inspiratory drive in the supine position increases to maintain the same level of ventilation as in the sitting position, and that the postural change from sitting to supine reduces breathing efficiency. Load compensation mechanisms of patients with OSA appear to be intact while awake in response to the rise in upper airway resistance. PMID:8322243

  17. Observations on pulpal response to carbon dioxide laser drilling of dentine in healthy human third molars.

    PubMed

    Nair, P N R; Baltensperger, M; Luder, H U; Eyrich, G K H

    2005-01-01

    Preservation of pulpal health is the primary prerequisite for successful application of laser systems in the hard tissue management of vital teeth. The purpose of this study was to investigate the short and long-term pulpal effects to cavity preparations in healthy human teeth using carbon dioxide (CO2) laser. A total of seven, healthy, third molars that were scheduled to be removed due to space problems were used. After the laser drilling, the occlusal cavities were closed temporarily, and the teeth were extracted 7 days (n=5) and 3 months (n=2) after the operation. The specimens were fixed, decalcified, subdivided and processed for light and transmission electron microscopy. Seven days postoperatively all the five teeth that had been irradiated with the CO2 laser did not reveal any pathological changes in the pulpo-dentine complex. Three months postoperatively the two teeth that were prepared with the laser showed subtle but distinct apposition of tertiary dentine that was lined with intact odontoblasts. One of the specimens at 3 months revealed the presence of a mild, but very circumscribed, pulpal infiltration of chronic inflammatory cells subjacent to the cavity preparation. The latter is unlikely to be due to a direct effect of the laser irradiation but a possible consequence of microleakage of oral antigens and/or other tissue-irritating molecules through the temporary restoration and the remaining dentine thickness (RDT). Although these preliminary histological results suggest that the CO2 laser under investigation induced only minimal response of the dentine-pulp complex when used as a hard-tissue drilling tool, with specific energy settings, pulse duration within thermal relaxation time and emitting radiations at 9.6 microm of wavelength, larger clinical trials involving various types of teeth are necessary to reach definite conclusions for large-scale clinical application of the laser device. PMID:15647971

  18. Are long-term trends in lake carbon dioxide flux responsive to climaticvariability and change?

    NASA Astrophysics Data System (ADS)

    Golub, M.; Desai, A. R.

    2012-12-01

    Inland water bodies are major but understudied conduits of carbon in within the global land-ocean-atmosphere carbon cycle. While many researchers have shown significant 20th century trends in physical and biological lake processes driven by climatic change, there is less research on how these influence lake-atmosphere carbon dioxide flux. We investigated the effects of climatic drivers on physical features and CO2 flux in lakes. We estimated the long-term trends in ice phenology, thermal structure, and amount of carbon exchanged, using 15-25-year time series of measurements of temperature, alkalinity, pH for eleven lakes monitored by the North Temperate Lakes Long-Term Ecological Research (NTL-LTER) program. Lakes coherently responded to regional climatic warming, showing declining ice cover duration, prolonged growing season, and increasingly warmer waters. Long-term trends of CO2 trends varied among lakes, however, with the majority of lakes showing a weakening source of CO2 to atmosphere. We further compared the sensitivity of CO2 flux to climate forcing in lakes as a function of trophic states, dissolved organic carbon concentrations, and morphometric features. These results provide new insights into our understanding about the role of lakes in regional and global carbon balances, on the sensitivity of CO2 flux to climatic variability, and in improving prediction of future carbon-climate change feedbacks.

  19. Growth and carbon isotopes of Mediterranean trees reveal contrasting responses to increased carbon dioxide and drought.

    PubMed

    Granda, Elena; Rossatto, Davi Rodrigo; Camarero, J Julio; Voltas, Jordi; Valladares, Fernando

    2014-01-01

    Forest dynamics will depend upon the physiological performance of individual tree species under more stressful conditions caused by climate change. In order to compare the idiosyncratic responses of Mediterranean tree species (Quercus faginea, Pinus nigra, Juniperus thurifera) coexisting in forests of central Spain, we evaluated the temporal changes in secondary growth (basal area increment; BAI) and intrinsic water-use efficiency (iWUE) during the last four decades, determined how coexisting species are responding to increases in atmospheric CO2 concentrations (C(a)) and drought stress, and assessed the relationship among iWUE and growth during climatically contrasting years. All species increased their iWUE (ca. +15 to +21%) between the 1970s and the 2000s. This increase was positively related to C(a) for J. thurifera and to higher C(a) and drought for Q. faginea and P. nigra. During climatically favourable years the study species either increased or maintained their growth at rising iWUE, suggesting a higher CO2 uptake. However, during unfavourable climatic years Q. faginea and especially P. nigra showed sharp declines in growth at enhanced iWUE, likely caused by a reduced stomatal conductance to save water under stressful dry conditions. In contrast, J. thurifera showed enhanced growth also during unfavourable years at increased iWUE, denoting a beneficial effect of C(a) even under climatically harsh conditions. Our results reveal significant inter-specific differences in growth driven by alternative physiological responses to increasing drought stress. Thus, forest composition in the Mediterranean region might be altered due to contrasting capacities of coexisting tree species to withstand increasingly stressful conditions. PMID:23928889

  20. Forecasting carbon dioxide emissions.

    PubMed

    Zhao, Xiaobing; Du, Ding

    2015-09-01

    This study extends the literature on forecasting carbon dioxide (CO2) emissions by applying the reduced-form econometrics approach of Schmalensee et al. (1998) to a more recent sample period, the post-1997 period. Using the post-1997 period is motivated by the observation that the strengthening pace of global climate policy may have been accelerated since 1997. Based on our parameter estimates, we project 25% reduction in CO2 emissions by 2050 according to an economic and population growth scenario that is more consistent with recent global trends. Our forecasts are conservative due to that we do not have sufficient data to fully take into account recent developments in the global economy.

  1. Carbon Dioxide Landscape

    NASA Technical Reports Server (NTRS)

    2004-01-01

    7 July 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a mid-summer view of the south polar residual cap at full MOC resolution, 1.5 m (5 ft) per pixel. During each of the three summers since the start of the MGS mapping mission in March 1999, the scarps that form mesas and pits in the 'Swiss cheese'-like south polar terrain have retreated an average of about 3 meters (1 yard). The material is frozen carbon dioxide; another 3 meters or so of each scarp is expected to be removed during the next summer, in late 2005. This image is located near 86.0oS, 350.8oW, and covers an area about 1.5 km (0.9 mi) wide. Sunlight illuminates the scene from the top/upper left.

  2. Forecasting carbon dioxide emissions.

    PubMed

    Zhao, Xiaobing; Du, Ding

    2015-09-01

    This study extends the literature on forecasting carbon dioxide (CO2) emissions by applying the reduced-form econometrics approach of Schmalensee et al. (1998) to a more recent sample period, the post-1997 period. Using the post-1997 period is motivated by the observation that the strengthening pace of global climate policy may have been accelerated since 1997. Based on our parameter estimates, we project 25% reduction in CO2 emissions by 2050 according to an economic and population growth scenario that is more consistent with recent global trends. Our forecasts are conservative due to that we do not have sufficient data to fully take into account recent developments in the global economy. PMID:26081307

  3. Change in atmospheric mineral aerosols in response to climate: Last glacial period, preindustrial, modern, and doubled carbon dioxide climates

    USGS Publications Warehouse

    Mahowald, N.M.; Muhs, D.R.; Levis, S.; Rasch, P.J.; Yoshioka, M.; Zender, C.S.; Luo, C.

    2006-01-01

    Desert dust simulations generated by the National Center for Atmospheric Research's Community Climate System Model for the current climate are shown to be consistent with present day satellite and deposition data. The response of the dust cycle to last glacial maximum, preindustrial, modern, and doubled-carbon dioxide climates is analyzed. Only natural (non-land use related) dust sources are included in this simulation. Similar to some previous studies, dust production mainly responds to changes in the source areas from vegetation changes, not from winds or soil moisture changes alone. This model simulates a +92%, +33%, and -60% change in dust loading for the last glacial maximum, preindustrial, and doubled-carbon dioxide climate, respectively, when impacts of carbon dioxide fertilization on vegetation are included in the model. Terrestrial sediment records from the last glacial maximum compiled here indicate a large underestimate of deposition in continental regions, probably due to the lack of simulation of glaciogenic dust sources. In order to include the glaciogenic dust sources as a first approximation, we designate the location of these sources, and infer the size of the sources using an inversion method that best matches the available data. The inclusion of these inferred glaciogenic dust sources increases our dust flux in the last glacial maximum from 2.1 to 3.3 times current deposition. Copyright 2006 by the American Geophysical Union.

  4. Response of vegetation to carbon dioxide - effect of elevated levels of CO{sub 2} on winter wheat under two moisture regimes

    SciTech Connect

    Chaudhuri, U.N.; Burnett, R.B.; Kanemasu, E.T.; Kirkham, M.B.

    1987-12-31

    This report deals with the second-year (1985-86) findings of an on going experiment with winter wheat (Triticum aestivum L.) at different carbon dioxide (CO{sub 2}) levels and under two moisture regimes. The results for the first year are given in the U.S. Department of Energy, Carbon Dioxide Research Division Response of Vegetation to Carbon Dioxide. The purpose of the second year`s experiment was to verify the results of 1984-85. However, based on the performance and the results of 1984-85 experiments, a few modifications were made.

  5. Optimizing supercritical carbon dioxide in the inactivation of bacteria in clinical solid waste by using response surface methodology

    SciTech Connect

    Hossain, Md. Sohrab; Nik Ab Rahman, Nik Norulaini; Balakrishnan, Venugopal; Alkarkhi, Abbas F.M.; Ahmad Rajion, Zainul; Ab Kadir, Mohd Omar

    2015-04-15

    Highlights: • Supercritical carbon dioxide sterilization of clinical solid waste. • Inactivation of bacteria in clinical solid waste using supercritical carbon dioxide. • Reduction of the hazardous exposure of clinical solid waste. • Optimization of the supercritical carbon dioxide experimental conditions. - Abstract: Clinical solid waste (CSW) poses a challenge to health care facilities because of the presence of pathogenic microorganisms, leading to concerns in the effective sterilization of the CSW for safe handling and elimination of infectious disease transmission. In the present study, supercritical carbon dioxide (SC-CO{sub 2}) was applied to inactivate gram-positive Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis, and gram-negative Escherichia coli in CSW. The effects of SC-CO{sub 2} sterilization parameters such as pressure, temperature, and time were investigated and optimized by response surface methodology (RSM). Results showed that the data were adequately fitted into the second-order polynomial model. The linear quadratic terms and interaction between pressure and temperature had significant effects on the inactivation of S. aureus, E. coli, E. faecalis, and B. subtilis in CSW. Optimum conditions for the complete inactivation of bacteria within the experimental range of the studied variables were 20 MPa, 60 °C, and 60 min. The SC-CO{sub 2}-treated bacterial cells, observed under a scanning electron microscope, showed morphological changes, including cell breakage and dislodged cell walls, which could have caused the inactivation. This espouses the inference that SC-CO{sub 2} exerts strong inactivating effects on the bacteria present in CSW, and has the potential to be used in CSW management for the safe handling and recycling-reuse of CSW materials.

  6. Response of electrochemical oxygen sensors to inert gas-air and carbon dioxide-air mixtures: measurements and mathematical modelling.

    PubMed

    Walsh, P T; Gant, S E; Dowker, K P; Batt, R

    2011-02-15

    Electrochemical oxygen gas sensors are widely used for monitoring the state of inertisation of flammable atmospheres and to warn of asphyxiation risks. It is well established but not widely known by users of such oxygen sensors that the response of the sensor is affected by the nature of the diluent gas responsible for the decrease in ambient oxygen concentration. The present work investigates the response of electrochemical sensors, with either acid or alkaline electrolytes, to gas mixtures comprising air with enhanced levels of nitrogen, carbon dioxide, argon or helium. The measurements indicate that both types of sensors over-read the oxygen concentrations when atmospheres contain high levels of helium. Sensors with alkaline electrolytes are also shown to underestimate the severity of the hazard in atmospheres containing high levels of carbon dioxide. This deviation is greater for alkaline electrolyte sensors compared to acid electrolyte sensors. A Computational Fluid Dynamics (CFD) model is developed to predict the response of an alkaline electrolyte, electrochemical gas sensor. Differences between predicted and measured sensor responses are less than 10% in relative terms for nearly all of the gas mixtures tested, and in many cases less than 5%. Extending the model to simulate responses of sensors with acid electrolytes would be straightforward.

  7. Responses of invasive silver and bighead carp to a carbon dioxide barrier in outdoor ponds

    USGS Publications Warehouse

    Cupp, Aaron R.; Erickson, Richard A.; Fredricks, Kim T.; Swyers, Nicholas M.; Hatton, Tyson; Amberg, Jon

    2016-01-01

    Resource managers need for effective methods to prevent the movement of silver (Hypophthalmichthys molitrix) and bighead carp (H. nobilis) from the Mississippi River basin into the Laurentian Great Lakes. In this study, we evaluated dissolved carbon dioxide (CO2) as a barrier and deterrent to silver (278 ± 30.5 mm) and bighead (212 ± 7.7 mm) carp movement in continuous-flow outdoor ponds. As a barrier, CO2 significantly reduced upstream movement but was not 100% effective at blocking fish passage. As a deterrent, we observed a significant shift away from areas of high CO2 relative to normal movement before and after injection. Carbon dioxide concentrations varied across the pond during injection and reached maximum concentrations of 74.5±1.9 mg/L CO2; 29 532 – 41 393 µatm at the site of injection during three independent trials. We conclude that CO2 altered silver and bighead carp movement in outdoor ponds and recommend further research to determine barrier effectiveness during field applications.

  8. Response of oats infected with barley yellow dwarf virus to elevated carbon dioxide

    SciTech Connect

    Malmstroem, C.M.; Field, C.B. |

    1995-06-01

    We examined the effects of elevated carbon dioxide on Avena sativa, cv. California Red, infected with barley yellow dwarf virus (BYDV) (PAV serotype). BYDV is a luteovirus that infects many genera of grasses, including Triticum, Hordeum, and Avena. Viral activity disrupts phloem transport, causing carbohydrate accumulation in leaves and reduction in root fraction. We measured tillering and biomass accumulation in individual Avena grown in large (2.5L) pots in temperature-controlled phytocells at two levels of carbon dioxide (ambient & ambient + 350 ppm). As expected, BYDV infection reduced plant growth and CO{sub 2} enrichment increased it. Notably, however, the percentage increase in biomass with enrichment was greatest for infected plants. The percentage change for infected plants was +33% at Day 42 and +32% at Day 60, but -2% and +10% for uninfected controls. Thus, enhanced carbohydrate production under enrichment may allow infected plants to partially overcome viral-induced restrictions in carbohydrate transport. This result raises an important issue, namely that diseased plants may respond differently than healthy ones to CO{sub 2} enrichment, with potential ecological consequences.

  9. Geologic Sequestration of Carbon Dioxide

    NASA Astrophysics Data System (ADS)

    Benson, S. M.

    2003-04-01

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

  10. The Effect of Temperature and Increased Rainfall on Carbon Dioxide Exchange in a High Arctic Ecosystem: Improving Models and Testing Linearity of Response

    NASA Astrophysics Data System (ADS)

    Steltzer, H.; Welker, J.; Sullivan, P.

    2006-12-01

    Ecosystem carbon dioxide exchange determines the terrestrial flux of carbon dioxide to the atmosphere through the two component processes of photosynthesis and respiration. Temperature and water availability are dominant factors that regulate carbon dioxide exchange and ecosystem productivity across the globe. Yet, in many ecosystems, the complex interaction of temperature and water availability and their individual and combined effects on photosynthesis and respiration make it difficult to predict how climate change will affect carbon dioxide exchange. For example, climate warming can increase carbon dioxide uptake in wetter Arctic ecosystems, but leads to the loss of carbon dioxide to the atmosphere in drier Arctic ecosystems. Characterizing how temperature and water availability affect ecosystem carbon exchange in the Arctic is essential to determine whether the rate of climate warming could accelerate due to carbon dioxide losses from Arctic ecosystems. We conducted a multi-level warming experiment that included control plots and two- levels of warming in a widespread High Arctic ecosystem. Infrared lamps were used to warm the tundra during the growing season and rainfall was increased by 50 percent in control plots and the higher level warming treatment. Carbon dioxide exchange was measured using chamber techniques over several 24-hour periods during the growing season for three years and was resolved into the component fluxes. Climate and biophysical variables that affect carbon dioxide exchange rates were measured in coordination with these flux measurements. We chose to analyze the data from this experiment by fitting the data to light and temperature response functions for gross ecosystem photosynthesis and ecosystem respiration, respectively. Based on our sample size of 30 experimental plots (5 treatments x 6 replicates), we selected relatively simple models of carbon dioxide exchange to minimize overfitting, but considered linear and nonlinear models

  11. Electrochemical response of carbon paste electrode modified with mixture of titanium dioxide/zirconium dioxide in the detection of heavy metals: lead and cadmium.

    PubMed

    Nguyen, Phuong Khanh Quoc; Lunsford, Suzanne K

    2012-11-15

    A novel carbon modified electrode was developed by incorporating titanium dioxide/zirconium dioxide into the graphite carbon paste electrode to detect heavy metals-cadmium and lead. In this work, the development of the novel titanium dioxide/zirconium dioxide modified carbon paste electrode was studied to determine the optimum synthesis conditions related to the temperature, heating duration, amount and ratio of titanium dioxide/zirconium dioxide, and amount of surfactant, to create the most reproducible results. Using cyclic voltammetric (CV) analysis, this study has proven that the novel titanium dioxide/zirconium dioxide can be utilized to detect heavy metals-lead and cadmium, at relatively low concentrations (7.6×10(-6) M and 1.1×10(-5) M for Pb and Cd, respectively) at optimum pH value (pH=3). From analyzing CV data the optimal electrodes surface area was estimated to be 0.028 (±0.003) cm(2). Also, under the specific experimental conditions, electron transfer coefficients were estimated to be 0.44 and 0.33 along with the heterogeneous electron transfer rate constants of 5.64×10(-3) and 2.42×10(-3) (cm/s) for Pb and Cd, respectively.

  12. Reducing carbon dioxide to products

    DOEpatents

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

    2014-09-30

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

  13. Response of soil carbon dioxide efflux to fire disturbance in a long-term grassland global change experiment

    NASA Astrophysics Data System (ADS)

    Strong, A. L.; Chiariello, N.; Tobeck, T.; Field, C. B.

    2012-12-01

    How terrestrial biosphere-atmosphere carbon dioxide exchange responds to global change is an important component to understanding global feedbacks of the carbon cycle. Soils represent a global store of organic carbon on the order of 3000 Pg C. Increased carbon dioxide release from increased respiration of soil C in response to climate warming and other direct and indirect anthropogenic factors could create a positive carbon cycle feedback to climate change. Numerous studies have demonstrated that soil respiration increases under experimental warming and elevated CO2, although the long-term, multi-year dynamics of this feedback remain poorly constrained. Punctuated disturbances, such as fire, are also likely to affect soil C responses, and understanding how fire and other global change factors interact in their influence on soil respiration is important in order to fully characterize climate-carbon cycle feedbacks. Previous studies have found that fire disturbance in semi-arid grasslands reduces soil CO2. The Jasper Ridge Global Change Experiment is a thirteen-year continuous full-factorial global change manipulation (elevated carbon dioxide, temperature, precipitation, and nitrogen deposition) located in a clay-loam soil grassland in central coastal California. In summer 2011, an additional treatment condition -- a controlled burn -- was applied to half the experimental plots to provide a fire treatment, and in the following growing season, soil carbon dioxide effluxes were measured at peak aboveground plant biomass (April 2012) and after summer senescence (June 2012) using a LiCOR-6400 soil respiration chamber and infrared gas analyzer. Across all plots and other treatments, CO2 fluxes were greater in burned grassland soils than in non-burned grassland soils (p < 0.01). CO2 fluxes were also greater in grassland plots with N addition than in grassland plots without additional nutrients (p < 0.01). These two effects appear to be additive, as CO2 fluxes were greater

  14. Recuperative supercritical carbon dioxide cycle

    SciTech Connect

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

    2014-11-18

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

  15. Tunable pulsed carbon dioxide laser

    NASA Technical Reports Server (NTRS)

    Megie, G. J.; Menzies, R. T.

    1981-01-01

    Transverse electrically-excited-atmosphere (TEA) laser is continuously tunable over several hundred megahertz about centers of spectral lines of carbon dioxide. It is operated in single longitudinal mode (SLM) by injection of beam from continuous-wave, tunable-waveguide carbon dioxide laser, which serves as master frequency-control oscillator. Device measures absorption line of ozone; with adjustments, it is applicable to monitoring of atmospheric trace species.

  16. Phytoplankton community response to carbon dioxide enrichment in winter incubation experiments

    EPA Science Inventory

    Coastal waters are experiencing changes in carbonate chemistry, including pH, in response to increases in atmospheric CO2 concentration and the microbial degradation of surplus organic matter associated with nutrient enrichment. The effects of this change on plankton communities ...

  17. Magnesite disposal of carbon dioxide

    SciTech Connect

    Lackner, K.S.; Butt, D.P.; Wendt, C.H.

    1997-08-01

    In this paper we report our progress on developing a method for carbon dioxide disposal whose purpose it is to maintain coal energy competitive even is environmental and political pressures will require a drastic reduction in carbon dioxide emissions. In contrast to most other methods, our approach is not aiming at a partial solution of the problem, or at buying time for phasing out fossil energy. Instead, its purpose is to obtain a complete and economic solution of the problem, and thus maintain access to the vast fossil energy reservoir. A successful development of this technology would guarantee energy availability for many centuries even if world economic growth the most optimistic estimates that have been put forward. Our approach differs from all others in that we are developing an industrial process which chemically binds the carbon dioxide in an exothermic reaction into a mineral carbonate that is thermodynamically stable and environmentally benign.

  18. Carbon dioxide effects on stomatal responses to the environment and water use by crops under field conditions.

    PubMed

    Bunce, James A

    2004-06-01

    Reductions in leaf stomatal conductance with rising atmospheric carbon dioxide concentration ([CO2]) could reduce water use by vegetation and potentially alter climate. Crop plants have among the largest reductions in stomatal conductance at elevated [CO2]. The relative reduction in stomatal conductance caused by a given increase in [CO2] is often not constant within a day nor between days, but may vary considerably with light, temperature and humidity. Species also differ in response, with a doubling of [CO2] reducing mean midday conductances by <15% in some crop species to >50% in others. Elevated [CO2] increases leaf area index throughout the growing season in some species. Simulations, and measurements in free air carbon dioxide enrichment systems both indicate that the relatively large reductions in stomatal conductance in crops would translate into reductions of <10% in evapotranspiration, partly because of increases in temperature and decreases in humidity in the air around crop leaves. The reduction in evapotranspiration in crops is similar to that in other types of vegetation which have smaller relative reductions in stomatal conductance, because of the poorer aerodynamic coupling of the canopy to the atmosphere in crops. The small decreases in evapotranspiration at elevated [CO2] may themselves be important to crop production in dry environments, but changes in climate and microclimate caused by reduced stomatal conductance could also be important to crop production. PMID:14557864

  19. Carbon Dioxide - Our Common "Enemy"

    NASA Technical Reports Server (NTRS)

    James, John T.; Macatangay, Ariel

    2009-01-01

    Health effects of brief and prolonged exposure to carbon dioxide continue to be a concern for those of us who manage this pollutant in closed volumes, such as in spacecraft and submarines. In both examples, considerable resources are required to scrub the atmosphere to levels that are considered totally safe for maintenance of crew health and performance. Defining safe levels is not a simple task because of many confounding factors, including: lack of a robust database on human exposures, suspected significant variations in individual susceptibility, variations in the endpoints used to assess potentially adverse effects, the added effects of stress, and the fluid shifts associated with micro-gravity (astronauts only). In 2007 the National Research Council proposed revised Continuous Exposure Guidelines (CEGLs) and Emergency Exposure Guidelines (EEGLs) to the U.S. Navy. Similarly, in 2008 the NASA Toxicology Group, in cooperation with another subcommittee of the National Research Council, revised Spacecraft Maximum Allowable Concentrations (SMACs). In addition, a 1000-day exposure limit was set for long-duration spaceflights to celestial bodies. Herein we examine the rationale for the levels proposed to the U.S. Navy and compare this rationale with the one used by NASA to set its limits. We include a critical review of previous studies on the effects of exposure to carbon dioxide and attempt to dissect out the challenges associated with setting fully-defensible limits. We also describe recent experiences with management of carbon dioxide aboard the International Space Station with 13 persons aboard. This includes the tandem operations of the Russian Vozduk and the U.S. Carbon Dioxide Removal System. A third removal system is present while the station is docked to the Shuttle spacecraft, so our experience includes the lithium hydroxide system aboard Shuttle for the removal of carbon dioxide. We discuss strategies for highly-efficient, regenerable removal of carbon

  20. Carbon Dioxide Absorption Heat Pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor)

    2002-01-01

    A carbon dioxide absorption heat pump cycle is disclosed using a high pressure stage and a super-critical cooling stage to provide a non-toxic system. Using carbon dioxide gas as the working fluid in the system, the present invention desorbs the CO2 from an absorbent and cools the gas in the super-critical state to deliver heat thereby. The cooled CO2 gas is then expanded thereby providing cooling and is returned to an absorber for further cycling. Strategic use of heat exchangers can increase the efficiency and performance of the system.

  1. Leaf physiological responses of mature Norway Spruce trees exposed to elevated carbon dioxide and temperature

    NASA Astrophysics Data System (ADS)

    Lamba, Shubhangi; Uddling, Johan; Räntfors, Mats; Hall, Marianne; Wallin, Göran

    2014-05-01

    Leaf photosynthesis, respiration and stomatal conductance exert strong control over the exchange of carbon, water and energy between the terrestrial biosphere and the atmosphere. As such, leaf physiological responses to rising atmospheric CO2 concentration ([CO2]) and temperature have important implications for the global carbon cycle and rate of ongoing global warming, as well as for local and regional hydrology and evaporative cooling. It is therefore critical to improve the understanding of plant physiological responses to elevated [CO2] and temperature, in particular for boreal and tropical ecosystems. In order to do so, we examined physiological responses of mature boreal Norway spruce trees (ca 40-years old) exposed to elevated [CO2] and temperature inside whole-tree chambers at Flakaliden research site, Northern Sweden. The trees were exposed to a factorial combination of two levels of [CO2] (ambient and doubled) and temperature (ambient and +2.8 degree C in summer and +5.6 degree C in winter). Three replicates in each of the four treatments were used. It was found that photosynthesis was increased considerably in elevated [CO2], but was not affected by the warming treatment. The maximum rate of photosynthetic carboxylation was reduced in the combined elevated [CO2] and elevated temperature treatment, but not in single factor treatments. Elevated [CO2] also strongly increased the base rate of respiration and to a lesser extent reduced the temperature sensitivity (Q10 value) of respiration; responses which may be important for the carbon balance of these trees which have a large proportion of shaded foliage. Stomatal conductance at a given VPD was reduced by elevated temperature treatment, to a degree that mostly offset the higher vapour pressure deficit in warmed air with respect to transpiration. Elevated [CO2] did not affect stomatal conductance, and thus increased the ratio of leaf internal to external [CO2]. These results indicate that the large elevated

  2. Process for sequestering carbon dioxide and sulfur dioxide

    DOEpatents

    Maroto-Valer, M. Mercedes; Zhang, Yinzhi; Kuchta, Matthew E.; Andresen, John M.; Fauth, Dan J.

    2009-10-20

    A process for sequestering carbon dioxide, which includes reacting a silicate based material with an acid to form a suspension, and combining the suspension with carbon dioxide to create active carbonation of the silicate-based material, and thereafter producing a metal salt, silica and regenerating the acid in the liquid phase of the suspension.

  3. High capacity carbon dioxide sorbent

    DOEpatents

    Dietz, Steven Dean; Alptekin, Gokhan; Jayaraman, Ambalavanan

    2015-09-01

    The present invention provides a sorbent for the removal of carbon dioxide from gas streams, comprising: a CO.sub.2 capacity of at least 9 weight percent when measured at 22.degree. C. and 1 atmosphere; an H.sub.2O capacity of at most 15 weight percent when measured at 25.degree. C. and 1 atmosphere; and an isosteric heat of adsorption of from 5 to 8.5 kilocalories per mole of CO.sub.2. The invention also provides a carbon sorbent in a powder, a granular or a pellet form for the removal of carbon dioxide from gas streams, comprising: a carbon content of at least 90 weight percent; a nitrogen content of at least 1 weight percent; an oxygen content of at most 3 weight percent; a BET surface area from 50 to 2600 m.sup.2/g; and a DFT micropore volume from 0.04 to 0.8 cc/g.

  4. 21 CFR 184.1240 - Carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Carbon dioxide. 184.1240 Section 184.1240 Food and....1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2, CAS Reg. No. 124-38-9) occurs as a..., sublimes under atmospheric pressure at a temperature of −78.5 °C. Carbon dioxide is prepared as a...

  5. Carbon dioxide transport over complex terrain

    USGS Publications Warehouse

    Sun, Jielun; Burns, Sean P.; Delany, A.C.; Oncley, S.P.; Turnipseed, A.; Stephens, B.; Guenther, A.; Anderson, D.E.; Monson, R.

    2004-01-01

    The nocturnal transport of carbon dioxide over complex terrain was investigated. The high carbon dioxide under very stable conditions flows to local low-ground. The regional drainage flow dominates the carbon dioxide transport at the 6 m above the ground and carbon dioxide was transported to the regional low ground. The results show that the local drainage flow was sensitive to turbulent mixing associated with local wind shear.

  6. Modelling Sublimation of Carbon Dioxide

    ERIC Educational Resources Information Center

    Winkel, Brian

    2012-01-01

    In this article, the author reports results in their efforts to model sublimation of carbon dioxide and the associated kinetics order and parameter estimation issues in their model. They have offered the reader two sets of data and several approaches to determine the rate of sublimation of a piece of solid dry ice. They presented several models…

  7. 21 CFR 582.1240 - Carbon dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is...

  8. 21 CFR 582.1240 - Carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is...

  9. 21 CFR 582.1240 - Carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is...

  10. 21 CFR 582.1240 - Carbon dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is...

  11. 21 CFR 582.1240 - Carbon dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is...

  12. Feedback regulated drug delivery vehicles: carbon dioxide responsive cationic hydrogels for antidote release.

    PubMed

    Satav, Sunita S; Bhat, Shreedhar; Thayumanavan, S

    2010-07-12

    A possible approach to handling the harmful side effects of an analgesic overdose, without losing its therapeutic potential, involves feedback regulated delivery of an antidote. For example, overdose of morphine causes hypoventilation, an inadequate ventilation to perform gas exchanges in lungs leading to increased CO2 concentration in the blood. Taking advantage of CO2 as a toxicity marker, a hydrogel-based delivery vehicle containing dimethylamino groups [poly(N,N-dimethylaminoethyl methacrylate) cross-linked by trimethylolpropane trimethacrylate] was designed. Stimulus controlled swelling of these hydrogels in naloxone delivery is discussed. A remarkable control over naloxone release was achieved against the concentration of the biomarker. The overall stimuli response of the gel could be enhanced further by encapsulating carbonic anhydrase, a metalloenzyme known to catalyze the reversible hydration of CO2. Thus, a feedback regulated drug delivery vehicle based on toxicity biomarker strategy was modeled successfully, which has the potential to mitigate risks associated with drug overdose.

  13. CO/sub 2/ in plants: the response of plants to rising levels of atmospheric carbon dioxide

    SciTech Connect

    Lemon, E.R.

    1985-01-01

    This book is the product of an international conference--the purpose of which was to identify what needs to be known regarding the biological effects on plants of a rising level of atmospheric carbon dioxide. The conference was held under the auspices of the Department of Energy's Carbon Dioxide Program and organized by the AAAS. Although the conference was held during May 1982 and the Proceedings published in 1983, the reader may be assured that the information presented in this book is still 'state of the art' in almost all respects.

  14. CARBON DIOXIDE AS A FEEDSTOCK.

    SciTech Connect

    CREUTZ,C.; FUJITA,E.

    2000-12-09

    This report is an overview on the subject of carbon dioxide as a starting material for organic syntheses of potential commercial interest and the utilization of carbon dioxide as a substrate for fuel production. It draws extensively on literature sources, particularly on the report of a 1999 Workshop on the subject of catalysis in carbon dioxide utilization, but with emphasis on systems of most interest to us. Atmospheric carbon dioxide is an abundant (750 billion tons in atmosphere), but dilute source of carbon (only 0.036 % by volume), so technologies for utilization at the production source are crucial for both sequestration and utilization. Sequestration--such as pumping CO{sub 2} into sea or the earth--is beyond the scope of this report, except where it overlaps utilization, for example in converting CO{sub 2} to polymers. But sequestration dominates current thinking on short term solutions to global warming, as should be clear from reports from this and other workshops. The 3500 million tons estimated to be added to the atmosphere annually at present can be compared to the 110 million tons used to produce chemicals, chiefly urea (75 million tons), salicylic acid, cyclic carbonates and polycarbonates. Increased utilization of CO{sub 2} as a starting material is, however, highly desirable, because it is an inexpensive, non-toxic starting material. There are ongoing efforts to replace phosgene as a starting material. Creation of new materials and markets for them will increase this utilization, producing an increasingly positive, albeit small impact on global CO{sub 2} levels. The other uses of interest are utilization as a solvent and for fuel production and these will be discussed in turn.

  15. Simulating carbon dioxide exchange rates of deciduous tree species: evidence for a general pattern in biochemical changes and water stress response

    PubMed Central

    Reynolds, Robert F.; Bauerle, William L.; Wang, Ying

    2009-01-01

    Background and Aims Deciduous trees have a seasonal carbon dioxide exchange pattern that is attributed to changes in leaf biochemical properties. However, it is not known if the pattern in leaf biochemical properties – maximum Rubisco carboxylation (Vcmax) and electron transport (Jmax) – differ between species. This study explored whether a general pattern of changes in Vcmax, Jmax, and a standardized soil moisture response accounted for carbon dioxide exchange of deciduous trees throughout the growing season. Methods The model MAESTRA was used to examine Vcmax and Jmax of leaves of five deciduous trees, Acer rubrum ‘Summer Red’, Betula nigra, Quercus nuttallii, Quercus phellos and Paulownia elongata, and their response to soil moisture. MAESTRA was parameterized using data from in situ measurements on organs. Linking the changes in biochemical properties of leaves to the whole tree, MAESTRA integrated the general pattern in Vcmax and Jmax from gas exchange parameters of leaves with a standardized soil moisture response to describe carbon dioxide exchange throughout the growing season. The model estimates were tested against measurements made on the five species under both irrigated and water-stressed conditions. Key Results Measurements and modelling demonstrate that the seasonal pattern of biochemical activity in leaves and soil moisture response can be parameterized with straightforward general relationships. Over the course of the season, differences in carbon exchange between measured and modelled values were within 6–12 % under well-watered conditions and 2–25 % under water stress conditions. Hence, a generalized seasonal pattern in the leaf-level physiological change of Vcmax and Jmax, and a standardized response to soil moisture was sufficient to parameterize carbon dioxide exchange for large-scale evaluations. Conclusions Simplification in parameterization of the seasonal pattern of leaf biochemical activity and soil moisture response of

  16. Cells in the female retrotrapezoid region upregulate c-fos in response to 10%, but not 5%, carbon dioxide.

    PubMed

    Niblock, Mary M; Lohr, Kelly M; Nixon, Melissa; Barnes, Caitlin; Schaudies, Meredith; Murphy, Mark

    2012-01-18

    The retrotrapezoid nucleus (RTN) is thought to regulate breathing in response to changes in blood carbon dioxide (CO(2)), and to make a vital contribution to respiratory drive, especially during sleep. However, cells in the female RTN fail to upregulate c-fos in response to low level CO(2) exposure, while cells in the male RTN have a robust upregulation of c-fos in response to low level CO(2) exposure. In this study, we examined the possibility that the female RTN has a higher threshold for c-fos upregulation in response to CO(2). Following exposure of Fos-Tau-LacZ (FTL) transgenic mice to 10% CO(2), c-fos was upregulated in just as many cells in the female as in the male RTN. In addition, the male RTN responded equivalently to 5% and 10% CO(2), consistent with a lack of a dose response to CO(2) in the male RTN. Cells in the nearby facial nucleus upregulated c-fos in the same number of cells regardless of sex or gas exposure, confirming that the sex difference in the RTN is unique to that nucleus. We propose that the male and female RTN upregulate c-fos differently in response to CO(2) due to differences in the transcriptional regulation by estrogens of genes that encode proteins related to neuronal excitability or specifically related to central chemoreception, such as potassium channels. These findings could have clinical relevance to sleep related breathing disorders that disproportionately affect males, including the sudden infant death syndrome and sleep apnea.

  17. Herbivore responses to plants grown in enriched carbon dioxide atmosphere. Progress report

    SciTech Connect

    Lincoln, D.E.

    1986-03-01

    These studies have shown that herbivore feeding may increase as atmospheric CO/sub 2/ rises. The increased feeding appears to result from the increased carbon/decreased nutrients in leaves from enriched CO/sub 2/ atmospheres. An initial study suggests that carbon-based secondary chemicals also change with CO/sub 2/ supply and influence herbivore feeding. 18 refs., 7 tabs.

  18. Oxygen and carbon dioxide sensing

    NASA Technical Reports Server (NTRS)

    Ren, Fan (Inventor); Pearton, Stephen John (Inventor)

    2012-01-01

    A high electron mobility transistor (HEMT) capable of performing as a CO.sub.2 or O.sub.2 sensor is disclosed, hi one implementation, a polymer solar cell can be connected to the HEMT for use in an infrared detection system. In a second implementation, a selective recognition layer can be provided on a gate region of the HEMT. For carbon dioxide sensing, the selective recognition layer can be, in one example, PEI/starch. For oxygen sensing, the selective recognition layer can be, in one example, indium zinc oxide (IZO). In one application, the HEMTs can be used for the detection of carbon dioxide and oxygen in exhaled breath or blood.

  19. Method for carbon dioxide sequestration

    SciTech Connect

    Wang, Yifeng; Bryan, Charles R.; Dewers, Thomas; Heath, Jason E.

    2015-09-22

    A method for geo-sequestration of a carbon dioxide includes selection of a target water-laden geological formation with low-permeability interbeds, providing an injection well into the formation and injecting supercritical carbon dioxide (SC--CO.sub.2) into the injection well under conditions of temperature, pressure and density selected to cause the fluid to enter the formation and splinter and/or form immobilized ganglia within the formation. This process allows for the immobilization of the injected SC--CO.sub.2 for very long times. The dispersal of scCO2 into small ganglia is accomplished by alternating injection of SC--CO.sub.2 and water. The injection rate is required to be high enough to ensure the SC--CO.sub.2 at the advancing front to be broken into pieces and small enough for immobilization through viscous instability.

  20. Summer Ice and Carbon Dioxide

    NASA Astrophysics Data System (ADS)

    Kukla, G.; Gavin, J.

    1981-10-01

    The extent of Antarctic pack ice in the summer, as charted from satellite imagery, decreased by 2.5 million square kilometers between 1973 and 1980. The U.S. Navy and Russian atlases and whaling and research ship reports from the 1930's indicate that summer ice conditions earlier in this century were heavier than the current average. Surface air temperatures along the seasonally shifting belt of melting snow between 55 degrees and 80 degrees N during spring and summer were higher in 1974 to 1978 than in 1934 to 1938. The observed departures in the two hemispheres qualitatively agree with the predicted impact of an increase in atmospheric carbon dioxide. However, since it is not known to what extent the changes in snow and ice cover and in temperature can be explained by the natural variability of the climate system or by other processes unrelated to carbon dioxide, a cause-and-effect relation cannot yet be established.

  1. Summer ice and carbon dioxide

    SciTech Connect

    Kukla, G.; Gavin, J.

    1981-10-30

    The extent of Antarctic pack ice in the summer, as charted from satellite imagery, decreased by 2.5 million square kilometers between 1973 and 1980. The U.S. Navy and Russian atlases and whaling and reseach ship reports from the 1930's indicate that summer ice conditions earlier in this century were heavier than the current average. Surface air temperatures along the seasonally shifting belt of melting snow between 55/sup o/ and 80/sup o/N during spring and summer were higher in 1974 to 1978 than in 1934 to 1938. The observed departures in the two hemispheres qualitatively agree with the predicted impact of an increase in atmospheric carbon dioxide. However, since it is not known to what extent the changes in snow and ice cover and in temperature can be explained by the natural variability of the climate system or by other processes unrelated to carbon dioxide, a cause-and-effect relation cannot yet be established.

  2. Electrochemically regenerable carbon dioxide absorber

    NASA Technical Reports Server (NTRS)

    Woods, R. R.; Marshall, R. D.; Schubert, F. H.; Heppner, D. B.

    1979-01-01

    Preliminary designs were generated for two electrochemically regenerable carbon dioxide absorber concepts. Initially, an electrochemically regenerable absorption bed concept was designed. This concept incorporated the required electrochemical regeneration components in the absorber design, permitting the absorbent to be regenerated within the absorption bed. This hardware was identified as the electrochemical absorber hardware. The second hardware concept separated the functional components of the regeneration and absorption process. This design approach minimized the extravehicular activity component volume by eliminating regeneration hardware components within the absorber. The electrochemical absorber hardware was extensively characterized for major operating parameters such as inlet carbon dioxide partial pressure, process air flow rate, operational pressure, inlet relative humidity, regeneration current density and absorption/regeneration cycle endurance testing.

  3. Physiological response of Crocosphaera watsonii to enhanced and fluctuating carbon dioxide conditions.

    PubMed

    Gradoville, Mary R; White, Angelicque E; Letelier, Ricardo M

    2014-01-01

    We investigated the effects of elevated pCO2 on cultures of the unicellular N2-fixing cyanobacterium Crocosphaera watsonii WH8501. Using CO2-enriched air, cultures grown in batch mode under high light intensity were exposed to initial conditions approximating current atmospheric CO2 concentrations (∼ 400 ppm) as well as CO2 levels corresponding to low- and high-end predictions for the year 2100 (∼ 750 and 1000 ppm). Following acclimation to CO2 levels, the concentrations of particulate carbon (PC), particulate nitrogen (PN), and cells were measured over the diurnal cycle for a six-day period spanning exponential and early stationary growth phases. High rates of photosynthesis and respiration resulted in biologically induced pCO2 fluctuations in all treatments. Despite this observed pCO2 variability, and consistent with previous experiments conducted under stable pCO2 conditions, we observed that elevated mean pCO2 enhanced rates of PC production, PN production, and growth. During exponential growth phase, rates of PC and PN production increased by ∼ 1.2- and ∼ 1.5-fold in the mid- and high-CO2 treatments, respectively, when compared to the low-CO2 treatment. Elevated pCO2 also enhanced PC and PN production rates during early stationary growth phase. In all treatments, PC and PN cellular content displayed a strong diurnal rhythm, with particulate C:N molar ratios reaching a high of 22:1 in the light and a low of 5.5:1 in the dark. The pCO2 enhancement of metabolic rates persisted despite pCO2 variability, suggesting a consistent positive response of Crocosphaera to elevated and fluctuating pCO2 conditions.

  4. Physiological Response of Crocosphaera watsonii to Enhanced and Fluctuating Carbon Dioxide Conditions

    PubMed Central

    Gradoville, Mary R.; White, Angelicque E.; Letelier, Ricardo M.

    2014-01-01

    We investigated the effects of elevated pCO2 on cultures of the unicellular N2-fixing cyanobacterium Crocosphaera watsonii WH8501. Using CO2-enriched air, cultures grown in batch mode under high light intensity were exposed to initial conditions approximating current atmospheric CO2 concentrations (∼400 ppm) as well as CO2 levels corresponding to low- and high-end predictions for the year 2100 (∼750 and 1000 ppm). Following acclimation to CO2 levels, the concentrations of particulate carbon (PC), particulate nitrogen (PN), and cells were measured over the diurnal cycle for a six-day period spanning exponential and early stationary growth phases. High rates of photosynthesis and respiration resulted in biologically induced pCO2 fluctuations in all treatments. Despite this observed pCO2 variability, and consistent with previous experiments conducted under stable pCO2 conditions, we observed that elevated mean pCO2 enhanced rates of PC production, PN production, and growth. During exponential growth phase, rates of PC and PN production increased by ∼1.2- and ∼1.5-fold in the mid- and high-CO2 treatments, respectively, when compared to the low-CO2 treatment. Elevated pCO2 also enhanced PC and PN production rates during early stationary growth phase. In all treatments, PC and PN cellular content displayed a strong diurnal rhythm, with particulate C:N molar ratios reaching a high of 22∶1 in the light and a low of 5.5∶1 in the dark. The pCO2 enhancement of metabolic rates persisted despite pCO2 variability, suggesting a consistent positive response of Crocosphaera to elevated and fluctuating pCO2 conditions. PMID:25343645

  5. The Impact of Carbon Dioxide on Climate.

    ERIC Educational Resources Information Center

    MacDonald, Gordon J.

    1979-01-01

    Examines the relationship between climatic change and carbon dioxide from the historical perspective; details the contributions of carbon-based fuels to increasing carbon dioxide concentrations; and using global circulation models, discusses the future impact of the heavy reliance of our society on carbon-based fuels on climatic change. (BT)

  6. Carbon dioxide conversion over carbon-based nanocatalysts.

    PubMed

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

    2013-07-01

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

  7. A carbon dioxide avoidance behavior is integrated with responses to ambient oxygen and food in Caenorhabditis elegans.

    PubMed

    Bretscher, Andrew Jonathan; Busch, Karl Emanuel; de Bono, Mario

    2008-06-10

    Homeostasis of internal carbon dioxide (CO2) and oxygen (O2) levels is fundamental to all animals. Here we examine the CO2 response of the nematode Caenorhabditis elegans. This species inhabits rotting material, which typically has a broad CO2 concentration range. We show that well fed C. elegans avoid CO2 levels above 0.5%. Animals can respond to both absolute CO2 concentrations and changes in CO2 levels within seconds. Responses to CO2 do not reflect avoidance of acid pH but appear to define a new sensory response. Sensation of CO2 is promoted by the cGMP-gated ion channel subunits TAX-2 and TAX-4, but other pathways are also important. Robust CO2 avoidance in well fed animals requires inhibition of the DAF-16 forkhead transcription factor by the insulin-like receptor DAF-2. Starvation, which activates DAF-16, strongly suppresses CO2 avoidance. Exposure to hypoxia (<1% O2) also suppresses CO2 avoidance via activation of the hypoxia-inducible transcription factor HIF-1. The npr-1 215V allele of the naturally polymorphic neuropeptide receptor npr-1, besides inhibiting avoidance of high ambient O2 in feeding C. elegans, also promotes avoidance of high CO2. C. elegans integrates competing O2 and CO2 sensory inputs so that one response dominates. Food and allelic variation at NPR-1 regulate which response prevails. Our results suggest that multiple sensory inputs are coordinated by C. elegans to generate different coherent foraging strategies.

  8. A carbon dioxide avoidance behavior is integrated with responses to ambient oxygen and food in Caenorhabditis elegans.

    PubMed

    Bretscher, Andrew Jonathan; Busch, Karl Emanuel; de Bono, Mario

    2008-06-10

    Homeostasis of internal carbon dioxide (CO2) and oxygen (O2) levels is fundamental to all animals. Here we examine the CO2 response of the nematode Caenorhabditis elegans. This species inhabits rotting material, which typically has a broad CO2 concentration range. We show that well fed C. elegans avoid CO2 levels above 0.5%. Animals can respond to both absolute CO2 concentrations and changes in CO2 levels within seconds. Responses to CO2 do not reflect avoidance of acid pH but appear to define a new sensory response. Sensation of CO2 is promoted by the cGMP-gated ion channel subunits TAX-2 and TAX-4, but other pathways are also important. Robust CO2 avoidance in well fed animals requires inhibition of the DAF-16 forkhead transcription factor by the insulin-like receptor DAF-2. Starvation, which activates DAF-16, strongly suppresses CO2 avoidance. Exposure to hypoxia (<1% O2) also suppresses CO2 avoidance via activation of the hypoxia-inducible transcription factor HIF-1. The npr-1 215V allele of the naturally polymorphic neuropeptide receptor npr-1, besides inhibiting avoidance of high ambient O2 in feeding C. elegans, also promotes avoidance of high CO2. C. elegans integrates competing O2 and CO2 sensory inputs so that one response dominates. Food and allelic variation at NPR-1 regulate which response prevails. Our results suggest that multiple sensory inputs are coordinated by C. elegans to generate different coherent foraging strategies. PMID:18524954

  9. Carbon Dioxide Removal via Passive Thermal Approaches

    NASA Technical Reports Server (NTRS)

    Lawson, Michael; Hanford, Anthony; Conger, Bruce; Anderson, Molly

    2011-01-01

    A paper describes a regenerable approach to separate carbon dioxide from other cabin gases by means of cooling until the carbon dioxide forms carbon dioxide ice on the walls of the physical device. Currently, NASA space vehicles remove carbon dioxide by reaction with lithium hydroxide (LiOH) or by adsorption to an amine, a zeolite, or other sorbent. Use of lithium hydroxide, though reliable and well-understood, requires significant mass for all but the shortest missions in the form of lithium hydroxide pellets, because the reaction of carbon dioxide with lithium hydroxide is essentially irreversible. This approach is regenerable, uses less power than other historical approaches, and it is almost entirely passive, so it is more economical to operate and potentially maintenance- free for long-duration missions. In carbon dioxide removal mode, this approach passes a bone-dry stream of crew cabin atmospheric gas through a metal channel in thermal contact with a radiator. The radiator is pointed to reject thermal loads only to space. Within the channel, the working stream is cooled to the sublimation temperature of carbon dioxide at the prevailing cabin pressure, leading to formation of carbon dioxide ice on the channel walls. After a prescribed time or accumulation of carbon dioxide ice, for regeneration of the device, the channel is closed off from the crew cabin and the carbon dioxide ice is sublimed and either vented to the environment or accumulated for recovery of oxygen in a fully regenerative life support system.

  10. A comparative study of esmolol and dexmedetomidine on hemodynamic responses to carbon dioxide pneumoperitoneum during laparoscopic surgery

    PubMed Central

    Bhattacharjee, Dhurjoti Prosad; Saha, Sauvik; Paul, Sanjib; Roychowdhary, Shibsankar; Mondal, Shirsendu; Paul, Suhrita

    2016-01-01

    Background: Carbon dioxide pneumoperitoneum for laparoscopic surgery increases arterial pressures, heart rate (HR), and systemic vascular resistance. In this randomized, single-blind, placebo-controlled clinical study, we investigated and compared the efficacy of esmolol and dexmedetomidine to provide perioperative hemodynamic stability in patients undergoing laparoscopic cholecystectomy. Methods: Sixty patients, of either sex undergoing elective laparoscopic cholecystectomy, were randomly allocated into three groups containing twenty patients each. Group E received bolus dose of 500 μg/kg intravenous (IV) esmolol before pneumoperitoneum followed by an infusion of 100 μg/kg/min. Group D received bolus dose of 1 μg/kg IV dexmedetomidine before pneumoperitoneum followed by infusion of 0.2 μg/kg/h. Group S (control) received saline 0.9%. Results: Mean arterial pressure and HR in Group E and D were significantly less throughout the period of pneumoperitoneum in comparison to Group S. IV nitroglycerine was required in 45% (9 out of 20) patients in Group S to control intraoperative hypertension, and it was clinically significant in comparison to Group E and D. Conclusion: Both esmolol and dexmedetomidine attenuate the adverse hemodynamic response to pneumoperitoneum and provide hemodynamic stability during laparoscopic surgery. PMID:27746555

  11. Optimizing supercritical carbon dioxide in the inactivation of bacteria in clinical solid waste by using response surface methodology.

    PubMed

    Hossain, Md Sohrab; Nik Ab Rahman, Nik Norulaini; Balakrishnan, Venugopal; Alkarkhi, Abbas F M; Ahmad Rajion, Zainul; Ab Kadir, Mohd Omar

    2015-04-01

    Clinical solid waste (CSW) poses a challenge to health care facilities because of the presence of pathogenic microorganisms, leading to concerns in the effective sterilization of the CSW for safe handling and elimination of infectious disease transmission. In the present study, supercritical carbon dioxide (SC-CO2) was applied to inactivate gram-positive Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis, and gram-negative Escherichia coli in CSW. The effects of SC-CO2 sterilization parameters such as pressure, temperature, and time were investigated and optimized by response surface methodology (RSM). Results showed that the data were adequately fitted into the second-order polynomial model. The linear quadratic terms and interaction between pressure and temperature had significant effects on the inactivation of S. aureus, E. coli, E. faecalis, and B. subtilis in CSW. Optimum conditions for the complete inactivation of bacteria within the experimental range of the studied variables were 20 MPa, 60 °C, and 60 min. The SC-CO2-treated bacterial cells, observed under a scanning electron microscope, showed morphological changes, including cell breakage and dislodged cell walls, which could have caused the inactivation. This espouses the inference that SC-CO2 exerts strong inactivating effects on the bacteria present in CSW, and has the potential to be used in CSW management for the safe handling and recycling-reuse of CSW materials.

  12. Response of carbon dioxide emissions to warming under no-till and conventional till systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    No-tillage (NT) tends to have greater soil organic carbon (SOC) stored in the surface soil layer relative to (conventional tillage) CT but few studies have addressed the stability of the SOC under conditions of global warming. An open warming experiment was conducted in situ by infrared heating of l...

  13. Behavioral responses of Drosophila to biogenic levels of carbon dioxide depend on life-stage, sex and olfactory context.

    PubMed

    Faucher, Cécile; Forstreuter, Manfred; Hilker, Monika; de Bruyne, Marien

    2006-07-01

    Drosophila melanogaster (Meigen) detects and uses many volatiles for its survival. Carbon dioxide (CO(2)) is detected in adults by a special class of olfactory receptor neurons, expressing the gustatory receptor Gr21a. The behavioral responses to CO(2) were investigated in a four-field olfactometer bioassay that is new for Drosophila. We determined (1) whether the sensitivity of this response changes with odor context, and (2) if it depends on sex and life stage. When CO(2) was added to ambient air in one field and tested against ambient air in the three other fields, individually observed adults avoided CO(2) (0.1-1% above ambient), but did not respond to a low rise of 0.02%. We relate this behavior to measurements of CO(2) production in bananas and flies. When 0.02% CO(2) was combined with the odor of apple cider vinegar in one field of the olfactometer and tested against ambient air in the three other fields, the addition of CO(2) did not affect the attractiveness of apple cider vinegar alone. However, this combination of CO(2) and vinegar became repellent when it was tested against vinegar at ambient CO(2) concentrations in the three other fields. This ;odor background effect' was female-specific, revealing a sexually dimorphic behavior. The new assay allowed us to test larvae under similar conditions and compare their behavior to that of adults. Like adults, they avoided CO(2), but with lower sensitivity. Larvae lacking neurons expressing Gr21a lost their avoidance behavior to CO(2), but kept their positive response to vinegar odor. Hence, Gr21a-expressing neurons mediate similar behaviors in larvae and adults. PMID:16809465

  14. Response of a tundra ecosystem to elevated atmospheric carbon dioxide and CO{sub 2}-induced climate change. Progress report

    SciTech Connect

    Oechel, W.C.

    1992-04-01

    This report presents the progress on the DOE funded project: ``Response of a Tundra Ecosystem to Elevated Atmospheric Carbon Dioxide and CO{sub 2}-Induced Climate Change.`` The current funding cycle was initiated on September 1, 1989, to run through August 31, 1992. There was an initial reduction in scope dictated by budget availabilities, primarily manipulations of CO{sub 2}, temperature and nutrients at a wet tundra located at Barrow Alaska. These experiments still need to be done over the mid- to longer term in order to accurately predict, apriori, the effects of climate change on the arctic tundra as well as possible feedbacks. Coordination and cooperation with other agencies was initiated in 1990 and formally proposed in our 1991 renewal at the national and international level and has become an important aspect of the research. To accurately and precisely scale plot and transect measurements to the circumpolar tundra is beyond the scope of the current DOE project. It is possible, however to determine the patterns and controls of CO{sub 2} flux from the current circumpolar arctic tundra with the involvement of additional agencies and governments. Results from the past two years of this project confirm that the arctic has become a source of CO{sub 2} to the atmosphere. This change coincides with recent climatic variation in the arctic, and suggest a positive feedback of arctic ecosystems on atmospheric CO{sub 2} and global change. Measurements along a latitudinal gradient across the north slope of Alaska indicate a loss of carbon from tussock tundra and wet tundra, decreasing in magnitude along a decreasing gradient of temperature but an increasing gradient in soil moisture. These data are in agreement with work done on tussock tundra in 1983{endash}85 and 1987.

  15. Response of a tundra ecosystem to elevated atmospheric carbon dioxide and CO sub 2 -induced climate change

    SciTech Connect

    Oechel, W.C.

    1992-04-01

    This report presents the progress on the DOE funded project: Response of a Tundra Ecosystem to Elevated Atmospheric Carbon Dioxide and CO{sub 2}-Induced Climate Change.'' The current funding cycle was initiated on September 1, 1989, to run through August 31, 1992. There was an initial reduction in scope dictated by budget availabilities, primarily manipulations of CO{sub 2}, temperature and nutrients at a wet tundra located at Barrow Alaska. These experiments still need to be done over the mid- to longer term in order to accurately predict, apriori, the effects of climate change on the arctic tundra as well as possible feedbacks. Coordination and cooperation with other agencies was initiated in 1990 and formally proposed in our 1991 renewal at the national and international level and has become an important aspect of the research. To accurately and precisely scale plot and transect measurements to the circumpolar tundra is beyond the scope of the current DOE project. It is possible, however to determine the patterns and controls of CO{sub 2} flux from the current circumpolar arctic tundra with the involvement of additional agencies and governments. Results from the past two years of this project confirm that the arctic has become a source of CO{sub 2} to the atmosphere. This change coincides with recent climatic variation in the arctic, and suggest a positive feedback of arctic ecosystems on atmospheric CO{sub 2} and global change. Measurements along a latitudinal gradient across the north slope of Alaska indicate a loss of carbon from tussock tundra and wet tundra, decreasing in magnitude along a decreasing gradient of temperature but an increasing gradient in soil moisture. These data are in agreement with work done on tussock tundra in 1983{endash}85 and 1987.

  16. Solubility of Carbon Dioxide in Water.

    ERIC Educational Resources Information Center

    Bush, Pat; And Others

    1992-01-01

    Describes an activity measuring the amount of dissolved carbon dioxide in carbonated water at different temperatures. The amount of carbon dioxide is measured by the amount of dilute ammonia solution needed to produce a pH indicator color change. (PR)

  17. 21 CFR 184.1240 - Carbon dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Carbon dioxide. 184.1240 Section 184.1240 Food and... Substances Affirmed as GRAS § 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2, CAS Reg. No.... The solid form, dry ice, sublimes under atmospheric pressure at a temperature of −78.5 °C....

  18. 21 CFR 184.1240 - Carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Carbon dioxide. 184.1240 Section 184.1240 Food and... Substances Affirmed as GRAS § 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2, CAS Reg. No.... The solid form, dry ice, sublimes under atmospheric pressure at a temperature of −78.5 °C....

  19. 21 CFR 184.1240 - Carbon dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Carbon dioxide. 184.1240 Section 184.1240 Food and... Substances Affirmed as GRAS § 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2, CAS Reg. No.... The solid form, dry ice, sublimes under atmospheric pressure at a temperature of −78.5 °C....

  20. 21 CFR 184.1240 - Carbon dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Carbon dioxide. 184.1240 Section 184.1240 Food and... Substances Affirmed as GRAS § 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2, CAS Reg. No.... The solid form, dry ice, sublimes under atmospheric pressure at a temperature of −78.5 °C....

  1. Longleaf pine photosynthetic response to soil resource availability and elevated atmospheric carbon dioxide

    SciTech Connect

    Runion, G.B.; Mitchell, R.J.; Green, T.H.; Prior, S.A.; Rogers, H.H.; Gjerstad, D.H.

    1999-05-01

    Gas exchange responses during a drought cycle were studied in longleaf pine (Pinus palustris Mill.) seedlings after prolonged exposure to varying levels of atmospheric CO{sub 2} soil N and water. Elevated atmospheric CO{sub 2} concentration increased photosynthesis, tended to decrease stomatal conductance, and increased water-use efficiency (WUE). Although soil resource availability influences gas exchange measurements, it generally did not affect the magnitude or direction of the response to CO{sub 2} concentration. However, significant interactions among treatment variables were observed for plant xylem pressure potential. In seedlings grown with high N, a positive growth response to elevated atmospheric CO{sub 2} increased whole-plant water use resulting in more severe plant water stress, despite increased leaf-level WUE; however, under low N conditions the lack of a growth response to elevated CO{sub 2} reduced whole-plant water use, decreased water stress severity, and increased WUE. Photosynthetic response to CO{sub 2} was greatest in the high N treatment at the beginning of the drought cycle, but diminished as water stress increased; however, plants grown with low N showed greater photosynthetic responses to CO{sub 2} later in the drought cycle. Therefore, plant gas exchange rates interact with growth response in determining the severity of water stress under drought and, thus, the ability of elevated atmospheric CO{sub 2} to ameliorate the effects of drought and allow plants to maintain increased rates of photosynthesis may be influenced by the availability of other resources, such as N and water.

  2. Carbon dioxide enrichment: Data on the response of cotton to varying CO{sub 2}, irrigation, and nitrogen

    SciTech Connect

    Sepanski, R.J.; Kimball, B.A.; Mauney, J.R.; La Morte, R.L.; Guinn, G.; Nakayama, F.S.; Radin, J.W.; Mitchell, S.T.; Parker, L.L.; Peresta, G.J.; Nixon, P.E. III; Savoy, B.; Harris, S.M.; MacDonald, R.; Pros, H.; Martinez, J.; Lakatos, E.A.

    1992-06-01

    This document presents results from field CO{sub 2}-enrichment experiments conducted over five consecutive growing seasons, 1983--1987. These results comprise data concerning the effects of continuous CO{sub 2} enrichment on the growth of cotton under optimal and limiting levels of water and nitrogen. Unlike many prior C0{sub 2} enrichment experiments in growth chambers or greenhouses, these studies were conducted on field-planted cotton at close to natural conditions using the open-top chamber approach. Measurements were made on a variety of crop response variables at intervals during the growing season and upon crop harvest. The initial experiment examined the effects of varying C0{sub 2} concentration only. In the following two seasons, the interactive effects of C0{sub 2} concentration and water availability were studied. In the final two seasons, the effects of the three-way interaction between C0{sub 2} concentration, water availability, and nitrogen fertility were investigated. The data comprise three types of information: identification variables (such as year, institution and situ codes, and treatment regimens), intermediate growth measurements (such as plant height, leaf area index, number of flowers, and dry weight of leaves) taken at various times during the growing season, and crop harvest results (such as lint yield, seed yield, and total aboveground dry biomass). They are available free of charge as a numeric data package (NAP) from the Carbon Dioxide Information Analysis Center. The NAP consists of this document and a magnetic tape (or a floppy diskette, upon request) containing machine-readable files. This document provides sample listings of the CO{sub 2} enrichment response data as they appear on the magnetic tape or floppy diskette and provides detailed descriptions of the design and methodology of these experiments, as well as a complete hard copy listing of all of the data in the form of a supplemental text provided as an appendix.

  3. Carbon dioxide enrichment: Data on the response of cotton to varying CO sub 2 , irrigation, and nitrogen

    SciTech Connect

    Sepanski, R.J. . Energy, Environment and Resources Center); Kimball, B.A.; Mauney, J.R.; La Morte, R.L.; Guinn, G.; Nakayama, F.S.; Radin, J.W.; Mitchell, S.T.; Parker, L.L.; Peresta, G.J.; Nixon, P.E. III; Savoy, B.; Harris, S.M.; MacDonald, R.; Pros, H.; Martinez, J. ); Lakatos, E.A. (Arizona Univ., Tucs

    1992-06-01

    This document presents results from field CO{sub 2}-enrichment experiments conducted over five consecutive growing seasons, 1983--1987. These results comprise data concerning the effects of continuous CO{sub 2} enrichment on the growth of cotton under optimal and limiting levels of water and nitrogen. Unlike many prior C0{sub 2} enrichment experiments in growth chambers or greenhouses, these studies were conducted on field-planted cotton at close to natural conditions using the open-top chamber approach. Measurements were made on a variety of crop response variables at intervals during the growing season and upon crop harvest. The initial experiment examined the effects of varying C0{sub 2} concentration only. In the following two seasons, the interactive effects of C0{sub 2} concentration and water availability were studied. In the final two seasons, the effects of the three-way interaction between C0{sub 2} concentration, water availability, and nitrogen fertility were investigated. The data comprise three types of information: identification variables (such as year, institution and situ codes, and treatment regimens), intermediate growth measurements (such as plant height, leaf area index, number of flowers, and dry weight of leaves) taken at various times during the growing season, and crop harvest results (such as lint yield, seed yield, and total aboveground dry biomass). They are available free of charge as a numeric data package (NAP) from the Carbon Dioxide Information Analysis Center. The NAP consists of this document and a magnetic tape (or a floppy diskette, upon request) containing machine-readable files. This document provides sample listings of the CO{sub 2} enrichment response data as they appear on the magnetic tape or floppy diskette and provides detailed descriptions of the design and methodology of these experiments, as well as a complete hard copy listing of all of the data in the form of a supplemental text provided as an appendix.

  4. Aircraft monitoring of surface carbon dioxide exchange

    SciTech Connect

    Desjardins, R.L.; Alvo, P.; Schuepp, P.H.

    1982-05-01

    Aircraft-mounted sensors were used to measure the exchange of carbon dioxide above a cornfield, a forest, and a lake under midday conditions. Mean absorption values of 3400, 1200, and 100 milligrams of carbon dioxide per square meter per hour, respectively, are consistent with reported ground-based observations of carbon dioxide flux. Such information, gathered by aircraft, could be used to provide a quantitative evaluation of source and sink distributions of carbon dioxide in the biosphere, to establish a correlation between satellite data and near-surface measurements, and to monitor crop performance.

  5. Carbon dioxide and intergenerational choice

    SciTech Connect

    D'Arge, R.C.; Schulze, W.D.; Brookshire, D.S.

    1982-05-01

    Depending on ethical beliefs, different decisions emerge for resolving the carbon dioxide (CO/sup 2/) issue. It is doubtful that an international consensus can be reached on a correct ethical criterion. Perhaps the best strategy would be to delay acceptance of either a particular set of beliefs or the existing scientific evidence and wait for more-accurate and conclusive research to emerge. If the scientific evidence is accepted as valid, and all future generations that will exist are evaluated equally, then the optimal current regulatory strategy is to restrict, as much as possible, current emissions of CO/sup 2/. 17 references, 2 figure, 1 table.

  6. Volcanic versus anthropogenic carbon dioxide

    USGS Publications Warehouse

    Gerlach, T.

    2011-01-01

    Which emits more carbon dioxide (CO2): Earth's volcanoes or human activities? Research findings indicate unequivocally that the answer to this frequently asked question is human activities. However, most people, including some Earth scientists working in fields outside volcanology, are surprised by this answer. The climate change debate has revived and reinforced the belief, widespread among climate skeptics, that volcanoes emit more CO2 than human activities [Gerlach, 2010; Plimer, 2009]. In fact, present-day volcanoes emit relatively modest amounts of CO2, about as much annually as states like Florida, Michigan, and Ohio.

  7. Soil carbon dioxide emissions in response to precipitation frequency in the Loess Plateau, China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Precipitation events can induce episodic CO2 emissions, so called the “Birch Effect”, but how precipitation frequency influences the mechanisms responsible for this effect in dryland cropping systems is not well known. We evaluated the effect of three precipitation frequencies (5-, 10-, and 20-d int...

  8. Molecular, behavioral, and performance responses of juvenile largemouth bass acclimated to an elevated carbon dioxide environment.

    PubMed

    Dennis, Clark E; Adhikari, Shivani; Wright, Adam W; Suski, Cory D

    2016-04-01

    Aquatic hypercarbia, either naturally occurring or anthropogenically induced, can have extensive impacts on aquatic environments and resident organisms. While the impact of acute hypercarbia exposure on the behavior and physiology of fishes has been well studied, relatively little work has examined the physiological impact and acclimation capacity of fishes to chronic hypercarbia. To better understand the impacts of prolonged hypercarbia exposure, largemouth bass were held at ambient CO2 (13 mg L(-1)) and elevated CO2 (31 mg L(-1); ≈ 21,000 µatm) for 58 days. Following this acclimation period, fish were subjected to three separate, yet complementary, experiments: (1) acute hypercarbia challenge of 120 mg L(-1) CO2 for 1 h to quantify physiological and molecular responses; (2) hypercarbia avoidance challenge to compare CO2 agitation and avoidance responses; and (3) swim performance challenge to quantify burst swimming performance. Acclimation to 31 mg L(-1) CO2 resulted in a significant constitutive upregulation of c-fos expression in erythrocytes, combined with significant constitutive expression of hsp70 in both gill and erythrocytes, relative to controls. Largemouth bass acclimated to elevated CO2 also had a reduced glucose response (relative to controls) following an acute CO2 exposure, indicating a reduced stress response to CO2 stressors. In addition, largemouth bass acclimated to elevated CO2 conditions required 50 % higher CO2 concentrations to illicit agitation behaviors and displayed prolonged burst swimming abilities in high CO2 environments relative to controls. Together, results demonstrate that largemouth bass exposed to chronic hypercarbia may possess a physiological advantage during periods of elevated CO2 relative to naïve fish, which may permit increased performance in hypercarbia. PMID:26758610

  9. GCM response of northern winter stationary waves and storm tracks to increasing amounts of carbon dioxide

    SciTech Connect

    Stephenson, D.B.; Held, I.M. )

    1993-10-01

    The response of the Geophysical Fluid Dynamics Laboratory (GFDL) coupled ocean-atmosphere R15, 9-level GCM to gradually increasing CO[sub 2] amounts is analyzed with emphasis on the changes in the stationary waves and storm tracks in the Northern Hemisphere wintertime troposphere. A large part of the change is described by an equivalent-barotropic stationary wave with a high over eastern Canada and a low over southern Alaska. Consistent with this, the Atlantic jet weakens near the North American coast. Perpetual winter runs of an R15, nine-level atmospheric GCM with sea surface temperature, sea ice thickness, and soil moisture values prescribed from the coupled GCM results are able to reproduce the coupled model's response qualitatively. Consistent with the weakened baroclinicity associated with the stationary wave change, the Atlantic storm track weakens with increasing CO[sub 2] concentrations while the Pacific storm track does not change in strength substantially. An R15, nine-level atmospheric model linearized about the zonal time-mean state is used to analyze the contributions to the stationary wave response. With mountains, diabatic heating, and transient forcings the linear model gives a stationary wave change in qualitative agreement with the change seen in the coupled and perpetual models. Transients and diabatic heating appear to be the major forcing terms, while changes in zonal-mean basic state and topographic forcing play only a small role. A substantial part of the diabatic response is due to changes in tropical latent heating. 25 refs., 36 figs.

  10. Response of tundra ecosystems to elevated atmospheric carbon dioxide: Final report

    SciTech Connect

    Oechel, W.C.

    1986-01-01

    This report includes: a detailed description of the system which we have developed for providing control of CO/sub 2/ and temperature; the effects of this treatment on ecosystem fluxes of CO/sub 2/ at ecosystem; the effects of three years CO/sub 2/ enrichment on the photosynthetic response of important tundra species; effects of mineral nutrition and CO/sub 2/ enrichment on growth, photosynthesis, and biomass partitioning of tundra species; and the effects of CO/sub 2/ on soil respiration.

  11. Behavioral Response of Hermit Crabs (Clibanarius digueti) to Dissolved Carbon Dioxide

    NASA Astrophysics Data System (ADS)

    Maier, H. J.

    2015-12-01

    CO2 induced ocean acidification is currently changing the population dynamics of marine organisms. As a result of ocean acidification, marine organisms expend extra energy on modifying behaviors. The current rate of ocean acidification will deplete the marine food chain that much of the world relies on as their major food supply. The purpose of this study was to understand whether and how ocean acidification affects the behavior of hermit crabs Clibanarius digueti. We hypothesized that an increase in carbonic acid would modify grazing and individual movement, because an increase in acidification alters the normal chemical composition of the water and potentially the niche occupancy of C. digueti. A model tidal pool experiment consisting of two tanks (control and treatment) inhabited with seven living C. digueti was set up in the Ocean Biome of Biosphere-2. Each tank was also provided with uninhabited shells: two Turbo fluctuosa and four Cerithium sp. Gaseous CO2 was dissolved into a treatment tank and measured as dissolved CO2 by using a sodium hydroxide titration method. Additionally, water conditions were characterized for UV- light and temperature. Two trials were run in this experiment with tanks and treatments interchanged in each trial. We assessed whether increased CO2 affected hermit crab shell change rate. We found that shell changes only happened among C. digueti placed under increased CO2. The information from this analysis will allow us to assess whether ocean acidification affects basic behavior in hermit crabs, which could later affect population dynamics. Bringing together all of this information will allow us to measure the effects of climate change on the behavior of C.Digueti.

  12. Response of tundra ecosystems to elevated atmospheric carbon dioxide. [Annual report

    SciTech Connect

    Oechel, W.C.; Grulke, N.E.

    1988-12-31

    Our past research shows that arctic tussock tundra responds to elevated atmospheric CO{sub 2} with marked increases in net ecosystem carbon flux and photosynthetic rates. However, at ambient temperatures and nutrient availabilities, homeostatic adjustments result in net ecosystem flux rates dropping to those found a contemporary CO{sub 2} levels within three years. Evidence for ecosystem-level acclimation in the first season of elevated CO{sub 2} exposure was found in 1987. Photosynthetic rates of Eriophorum vaginatum, the dominant species, adjusts to elevated CO{sub 2} within three weeks. Past research also indicates other changes potentially important to ecosystem structure and function. Elevated CO{sub 2} treatment apparently delays senescence and increases the period of positive photosynthetic activity. Recent results from the 1987 field season verify the results obtained in the 1983--1986 field seasons: Elevated CO{sub 2} resulted in increased ecosystem-level flux rates. Regressions fitted to the seasonal flux rates indicate an apparent 10 d extension of positive CO{sub 2} uptake reflecting a delay of the onset of plant dormancy. This delay in senescence could increase the frost sensitivity of the system. Major end points proposed for this research include the effects of elevated CO{sub 2} and the interaction of elevated atmospheric CO{sub 2} with elevated soil temperature and increased nutrient availability on: (1) Net ecosystem CO{sub 2} flux; (2) Net photosynthetic rates; (3) Patterns and resource controls on homeostatic adjustment in the above processes to elevated CO{sub 2}; (4) Plant-nutrient status, litter quality, and forage quality; (5) Soil-nutrient status; (6) Plant-growth pattern and shoot demography.

  13. Carbon dioxide research plan. A summary

    SciTech Connect

    Trivelpiece, Alvin W.; Koomanoff, F. A.; Suomi, Verner E.

    1983-11-01

    The Department of Energy is the lead federal agency for research related to atmospheric carbon dioxide. Its responsibility is to sponsor a program of relevant research, and to coordinate this research with that of others. As part of its responsibilities, the Department of Energy has prepared a research plan. The plan documented in this Summary delineated the logic, objectives, organization, background and current status of the research activities. The Summary Plan is based on research subplans in four specific areas: global carbon cycle, climate effects, vegetative response and indirect effects. These subplans have emanated from a series of national and international workshops, conferences, and from technical reports. The plans have been peer reviewed by experts in the relevant scientific fields. Their execution is being coordinated between the responsible federal and international government agencies and the involved scientific community.

  14. Carbon dioxide detection in adult Odonata.

    PubMed

    Piersanti, Silvana; Frati, Francesca; Rebora, Manuela; Salerno, Gianandrea

    2016-04-01

    The present paper shows, by means of single-cell recordings, responses of antennal sensory neurons of the damselfly Ischnura elegans when stimulated by air streams at different CO2 concentrations. Unlike most insects, but similarly to termites, centipedes and ticks, Odonata possess sensory neurons strongly inhibited by CO2, with the magnitude of the off-response depending upon the CO2 concentration. The Odonata antennal sensory neurons responding to CO2 are also sensitive to airborne odors; in particular, the impulse frequency is increased by isoamylamine and decreased by heptanoic and pentanoic acid. Further behavioral investigations are necessary to assign a biological role to carbon dioxide detection in Odonata. PMID:26831359

  15. Responses of Amazonian ecosystems to climatic and atmospheric carbon dioxide changes since the last glacial maximum.

    PubMed

    Mayle, Francis E; Beerling, David J; Gosling, William D; Bush, Mark B

    2004-03-29

    The aims of this paper are to review previously published palaeovegetation and independent palaeoclimatic datasets together with new results we present from dynamic vegetation model simulations and modern pollen rain studies to: (i) determine the responses of Amazonian ecosystems to changes in temperature, precipitation and atmospheric CO2 concentrations that occurred since the last glacial maximum (LGM), ca. 21 000 years ago; and (ii) use this long-term perspective to predict the likely vegetation responses to future climate change. Amazonia remained predominantly forested at the LGM, although the combination of reduced temperatures, precipitation and atmospheric CO2 concentrations resulted in forests structurally and floristically quite different from those of today. Cold-adapted Andean taxa mixed with rainforest taxa in central areas, while dry forest species and lianas probably became important in the more seasonal southern Amazon forests and savannahs expanded at forest-savannah ecotones. Net primary productivity (NPP) and canopy density were significantly lower than today. Evergreen rainforest distribution and NPP increased during the glacial-Holocene transition owing to ameliorating climatic and CO2 conditions. However, reduced precipitation in the Early-Mid-Holocene (ca. 8000-3600 years ago) caused widespread, frequent fires in seasonal southern Amazonia, causing increased abundance of drought-tolerant dry forest taxa and savannahs in ecotonal areas. Rainforests expanded once more in the Late Holocene owing to increased precipitation caused by greater austral summer insolation, although some of this forest expansion (e.g. in parts of the Bolivian Beni) is clearly caused by palaeo Indian landscape modification. The plant communities that existed during the Early-Mid-Holocene may provide insights into the kinds of vegetation response expected from similar increases in temperature and aridity predicted for the twenty-first century. We infer that ecotonal areas

  16. Responses of Amazonian ecosystems to climatic and atmospheric carbon dioxide changes since the last glacial maximum.

    PubMed Central

    Mayle, Francis E; Beerling, David J; Gosling, William D; Bush, Mark B

    2004-01-01

    The aims of this paper are to review previously published palaeovegetation and independent palaeoclimatic datasets together with new results we present from dynamic vegetation model simulations and modern pollen rain studies to: (i) determine the responses of Amazonian ecosystems to changes in temperature, precipitation and atmospheric CO2 concentrations that occurred since the last glacial maximum (LGM), ca. 21 000 years ago; and (ii) use this long-term perspective to predict the likely vegetation responses to future climate change. Amazonia remained predominantly forested at the LGM, although the combination of reduced temperatures, precipitation and atmospheric CO2 concentrations resulted in forests structurally and floristically quite different from those of today. Cold-adapted Andean taxa mixed with rainforest taxa in central areas, while dry forest species and lianas probably became important in the more seasonal southern Amazon forests and savannahs expanded at forest-savannah ecotones. Net primary productivity (NPP) and canopy density were significantly lower than today. Evergreen rainforest distribution and NPP increased during the glacial-Holocene transition owing to ameliorating climatic and CO2 conditions. However, reduced precipitation in the Early-Mid-Holocene (ca. 8000-3600 years ago) caused widespread, frequent fires in seasonal southern Amazonia, causing increased abundance of drought-tolerant dry forest taxa and savannahs in ecotonal areas. Rainforests expanded once more in the Late Holocene owing to increased precipitation caused by greater austral summer insolation, although some of this forest expansion (e.g. in parts of the Bolivian Beni) is clearly caused by palaeo Indian landscape modification. The plant communities that existed during the Early-Mid-Holocene may provide insights into the kinds of vegetation response expected from similar increases in temperature and aridity predicted for the twenty-first century. We infer that ecotonal areas

  17. Stimulation of border cell production in response to increased carbon dioxide levels.

    PubMed

    Zhao, X; Misaghi, I J; Hawes, M C

    2000-01-01

    Field soil atmospheres have higher CO(2) and lower O(2) concentrations compared with ambient atmosphere, but little is known about the impact of such conditions on root exudation patterns. We used altered levels of CO(2) and O(2) relative to ambient conditions to examine the influence of the atmosphere on the production of root border cells by pea (Pisum sativum) root tips. During germination, atmospheres with high CO(2) and low O(2) inhibited root development and border cell separation in pea seedlings. Later in development, the same atmospheric composition stimulated border cell separation without significantly influencing root growth. Increased CO(2), not low O(2), was responsible for the observed stimulation of border cell number. High CO(2) apparently can override endogenous signals that regulate the number of border cells released from pea roots into the rhizosphere. The same conditions that stimulated border cell production in pea had no such effect in alfalfa (Medicago sativa).

  18. Response of vegetation to carbon dioxide - sorghum at elevated levels of CO{sub 2}

    SciTech Connect

    Burnett, R.B.; Chaudhuri, U.N.; Kanemasu, E.T.; Kirkham, M.B.

    1985-12-31

    Enhancement of plant growth is an important effect of the rising concentration of atmospheric CO{sub 2}. Crops vary in response to elevated CO{sub 2}. Growth often appears greater in C{sub 3} plants than in C{sub 4} plants. But relatively little work has been done with C{sub 4} plants, and most of it has been with corn. The few existing C{sub 4} data conflict. Some studies indicate that the yield of C{sub 4} plants at elevated CO{sub 2} is about one-fourth that of C{sub 3} crops, but other studies show that C{sub 4} plants with increased CO{sub 2} yield at a rate the average for all crops.

  19. Responses of two summer annuals to interactions of atmospheric carbon dioxide and soil nitrogen

    SciTech Connect

    Thomas, R.B.

    1987-01-01

    The competitive relationship between Chenopodium album L. (C{sub 3}) and Amaranthus hybridus L. (C{sub 4}) was investigated in two atmospheric CO{sub 2} levels and tow soil nitrogen levels. Biomass and leaf surface area of Amaranthus plants did not respond to CO{sub 2} enrichment. Only in high nitrogen did Chenopodium plants respond to increased CO{sub 2} with greater biomass and leaf surface area. Nitrogen use efficiency (NUE) was higher in Amaranthus than in Chenopodium in all treatments except for the high-nitrogen high-CO{sub 2} treatment. Under conditions of high nitrogen and low CO{sub 2}, Chenopodium was a poor competitor, but competition favored Chenopodium in high nitrogen and high CO{sub 2}. In low nitrogen and high CO{sub 2}, competition favored Chenopodium on a dry weight basis, but favored Amaranthus on a seed weight basis, reflecting early senescence of Chenopodium. In low nitrogen and high CO{sub 2}, competition favored Amaranthus on a dry weight basis, but favored Chenopodium on a seed weight basis. Physiological aspects of the growth of Chenopodium and Amaranthus were studied. Acclimation to elevated CO{sub 2} occurred at the enzyme level in Chenopodium. Under conditions of high nitrogen and no competition, individual Chenopodium plants responded to elevated CO{sub 2} with greater biomass, leaf surface area, and maximum net photosynthetic rates. In high nitrogen, leaf nitrogen, soluble protein, and RuBP carboxylase activity of Chenopodium decreased and NUE increased when grown in elevated CO{sub 2}. In low nitrogen without competition, Chenopodium showed no significant response to CO{sub 2} enrichment. Amarantus grown in high and low nitrogen without competition showed no significant changes in leaf nitrogen, soluble protein, carboxylase activity, chlorophyll, or NUE of in response to CO{sub 2} enrichment.

  20. Photosynthetic responses to understory shade and elevated carbon dioxide concentration in four northern hardwood tree species.

    PubMed

    Sefcik, Lesley T; Zak, Donald R; Ellsworth, David S

    2006-12-01

    Seedling responses to elevated atmospheric CO(2) concentration ([CO(2)]) and solar irradiance were measured over two growing seasons in shade-tolerant Acer saccharum Marsh. and Fagus grandifolia J.F. Ehrh. and shade-intolerant Prunus serotina, a J.F. Ehrh. and Betula papyrifera Marsh. Seedlings were exposed to a factorial combination of [CO2] (ambient and elevated (658 micromol mol-1)) and understory shade (deep and moderate) in open-top chambers placed in a forest understory. The elevated [CO(2)] treatment increased mean light-saturated net photosynthetic rate by 63% in the shade-tolerant species and 67% in the shade-intolerant species. However, when measured at the elevated [CO(2)], long-term enhancement of photosynthesis was 10% lower than the instantaneous enhancement seen in ambient-[CO(2)]-grown plants (P < 0.021). Overall, growth light environment affected long-term photosynthetic enhancement by elevated [CO(2)]: as the growth irradiance increased, proportional enhancement due to elevated [CO(2)] decreased from 97% for plants grown in deep shade to 47% for plants grown in moderate shade. Results suggest that in N-limited northern temperate forests, trees grown in deep shade may display greater photosynthetic gains from a CO(2)-enriched atmosphere than trees growing in more moderate shade, because of greater downregulation in the latter environment. If photosynthetic gains by deep-shade-grown plants in response to elevated [CO(2)] translate into improved growth and survival of shade-intolerant species, it could alter the future composition and dynamics of successional forest communities. PMID:17169898

  1. Photosynthesis and growth responses of mustard (Brassica juncea L. cv Pusa Bold) plants to free air carbon dioxide enrichment (FACE).

    PubMed

    Ruhil, Kamal; Sheeba; Ahmad, Altaf; Iqbal, Muhammad; Tripathy, Baishnab C

    2015-07-01

    Increased atmospheric [CO2] is likely to affect photosynthesis, plant growth, and yield potential of plants. Mustard (Brassica juncea L.) is an important oil seed crop that is widely grown in India. Therefore, the impact of elevated [CO2] (585 μmol mol(-1)) on pigment and protein content, chlorophyll a fluorescence, photosynthetic electron transport reactions, CO2 assimilation, biomass production, and seed yield potential was measured in B. juncea cv Pusa Bold, grown inside free air carbon dioxide enrichment (FACE) rings installed on the campus of Jawaharlal Nehru University, New Delhi, India. Plants were grown for three consecutive winter seasons (2010-2013), in ambient (385 μmol mol(-1)) or elevated [CO2], in field conditions. Elevated [CO2] had no significant effect on the minimal chlorophyll fluorescence (F 0), while the quantum efficiency of Photosystem II, measured as variable fluorescence (F v = F m-F 0) to maximum fluoresence (F m), increased by 3 %. Electron transport rate, photosystem I, photosystem II, and whole chain electron transport rates increased by 8 % in elevated [CO2]. However, the net photosynthesis rate increased by ≈50 % in three growing seasons under elevated [CO2] condition. The stomatal conductance and transpiration rate decreased resulting in higher photosynthetic water use efficiency. The photosynthesizing surface, i.e., leaf area index substantially increased leading to higher biomass and seed yield under elevated [CO2] condition. Acclimatory downregulation of photosynthesis and plant productivity was not observed in three consecutive growing years suggesting that in the absence of nutrient limitation, B. juncea is highly responsive to elevated CO2 whose yield potential shall increase in changing climatic conditions. PMID:25471475

  2. Photosynthesis and growth responses of mustard (Brassica juncea L. cv Pusa Bold) plants to free air carbon dioxide enrichment (FACE).

    PubMed

    Ruhil, Kamal; Sheeba; Ahmad, Altaf; Iqbal, Muhammad; Tripathy, Baishnab C

    2015-07-01

    Increased atmospheric [CO2] is likely to affect photosynthesis, plant growth, and yield potential of plants. Mustard (Brassica juncea L.) is an important oil seed crop that is widely grown in India. Therefore, the impact of elevated [CO2] (585 μmol mol(-1)) on pigment and protein content, chlorophyll a fluorescence, photosynthetic electron transport reactions, CO2 assimilation, biomass production, and seed yield potential was measured in B. juncea cv Pusa Bold, grown inside free air carbon dioxide enrichment (FACE) rings installed on the campus of Jawaharlal Nehru University, New Delhi, India. Plants were grown for three consecutive winter seasons (2010-2013), in ambient (385 μmol mol(-1)) or elevated [CO2], in field conditions. Elevated [CO2] had no significant effect on the minimal chlorophyll fluorescence (F 0), while the quantum efficiency of Photosystem II, measured as variable fluorescence (F v = F m-F 0) to maximum fluoresence (F m), increased by 3 %. Electron transport rate, photosystem I, photosystem II, and whole chain electron transport rates increased by 8 % in elevated [CO2]. However, the net photosynthesis rate increased by ≈50 % in three growing seasons under elevated [CO2] condition. The stomatal conductance and transpiration rate decreased resulting in higher photosynthetic water use efficiency. The photosynthesizing surface, i.e., leaf area index substantially increased leading to higher biomass and seed yield under elevated [CO2] condition. Acclimatory downregulation of photosynthesis and plant productivity was not observed in three consecutive growing years suggesting that in the absence of nutrient limitation, B. juncea is highly responsive to elevated CO2 whose yield potential shall increase in changing climatic conditions.

  3. Carbon dioxide disposal in solid form

    SciTech Connect

    Lackner, K.S.; Butt, D.P.; Sharp, D.H.; Wendt, C.H.

    1995-12-31

    Coal reserves can provide for the world`s energy needs for centuries. However, coal`s long term use may be severely curtailed if the emission of carbon dioxide into the atmosphere is not eliminated. We present a safe and permanent method of carbon dioxide disposal that is based on combining carbon dioxide chemically with abundant raw materials to form stable carbonate minerals. We discuss the availability of raw materials and potential process designs. We consider our initial rough cost estimate of about 3{cents}/kWh encouraging. The availability of a carbon dioxide fixation technology would serve as insurance in case global warming, or the perception of global warming, causes severe restrictions on carbon dioxide emissions. If the increased energy demand of a growing world population is to be satisfied from coal, the implementation of such a technology would quite likely be unavoidable.

  4. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    SciTech Connect

    K.A.M. Gasem; R.L. Robinson, Jr.; L.R. Radovic

    2001-06-15

    The authors' long term goal is to develop accurate prediction methods for describing the adsorption behavior of gas mixtures on solid adsorbents over complete ranges of temperature, pressure and adsorbent types. The major objectives of the project are to: (1) measure the adsorption behavior of pure CO{sub 2}, methane, nitrogen and their binary and ternary mixtures on several selected coals having different properties at temperatures and pressures applicable to the particular coal being studied, (2) generalize the adsorption results in terms of appropriate properties of the coals, to facilitate estimation of adsorption behavior for coals other than those studied experimentally, (3) delineate the sensitivity of the competitive adsorption of CO{sub 2}, methane and nitrogen to the specific characteristics of the coal on which they are adsorbed; establish the major differences (if any) in the nature of this competitive adsorption on different coals, and (4) test and/or develop theoretically-based mathematical models to represent accurately the adsorption behavior of mixtures of the type for which measurements are made. The specific accomplishments of this project during this reporting period are summarized below in three broad categories outlining experimentation, model development, and coal characterization. (1) Experimental Work: Our adsorption apparatus was reassembled, and all instruments were tested and calibrated. Having confirmed the viability of the experimental apparatus and procedures used, adsorption isotherms for pure methane, carbon dioxide and nitrogen on wet Fruitland coal were measured at 319.3 K (115 F) and pressures to 12.4 MPa (1800 psia). These measurements showed good agreement with our previous data and yielded an expected uncertainty of about 2%. Preparations are underway to measure adsorption isotherms for pure methane, carbon dioxide and nitrogen on two other coals. (2) Model Development: The experimental data were used to evaluate the

  5. Reliable estimation of biochemical parameters from C3 leaf photosynthesis-intercellular carbon dioxide response curves

    SciTech Connect

    Wullschleger, Stan D; Gu, Lianhong; Pallardy, Stephen G.; Tu, Kevin; Law, Beverly E.

    2010-01-01

    The Farquhar-von Caemmerer-Berry (FvCB) model of photosynthesis is a change-point model and structurally overparameterized for interpreting the response of leaf net assimilation (A) to intercellular CO{sub 2} concentration (Ci). The use of conventional fitting methods may lead not only to incorrect parameters but also several previously unrecognized consequences. For example, the relationships between key parameters may be fixed computationally and certain fits may be produced in which the estimated parameters result in contradictory identification of the limitation states of the data. Here we describe a new approach that is better suited to the FvCB model characteristics. It consists of four main steps: (1) enumeration of all possible distributions of limitation states; (2) fitting the FvCB model to each limitation state distribution by minimizing a distribution-wise cost function that has desirable properties for parameter estimation; (3) identification and correction of inadmissible fits; and (4) selection of the best fit from all possible limitation state distributions. The new approach implemented theoretical parameter resolvability with numerical procedures that maximally use the information content of the data. It was tested with model simulations, sampled A/Ci curves, and chlorophyll fluorescence measurements of different tree species. The new approach is accessible through the automated website leafweb.ornl.gov.

  6. Elevated carbon dioxide influences yield and photosynthetic responses of hydroponically-grown sweetpotato

    NASA Technical Reports Server (NTRS)

    Mortley, D.; Hill, J.; Loretan, P.; Bonsi, C.; Hill, W.; Hileman, D.; Terse, A.

    1996-01-01

    The response of 'TI-155' and 'Georgia Jet' sweetpotato cultivars to elevated CO2 concentrations of 400 (ambient), 750 and 1000 micromoles mol-1 were evaluated under controlled environment conditions using the nutrient film technique (NFT). Growth chamber conditions included photosynthetic photon flux (PPF) of 600 micromoles m-2 s-1, 14/10 light/dark period, and 70% +/- 5% RH. Plants were grown using a modified half-Hoagland nutrient solution with a pH range of 5.5-6.0 and an electrical conductivity of 0.12 S m-1. Gas exchange measurements were made using infrared gas analysis, an open-flow gas exchange system, and a controlled-climate cuvette. Photosynthetic (Pn) measurements were made at CO2 ranges of 50 to 1000 micromoles mol-1. Storage root yield/plant increased with CO2 up to 750 but declined at 1000 micromoles mol-1. Storage root dry matter (DM) and foliage dry weight increased with increasing CO2. Harvest index (HI) for both cultivars was highest at 750 micromoles mol-1. The PPF vs Pn curves were typical for C3 plants with saturation occurring at approximately 600 micromoles m-2 s-1. CO2 concentration did not significantly influence net Pn, transpiration, water-use-efficiency (WUE), and stomatal conductance. As measurement CO2 concentration increased, net Pn and WUE increased while transpiration and stomatal conductance decreased.

  7. Cardiovascular System Response to Carbon Dioxide and Exercise in Oxygen-Enriched Environment at 3800 m

    PubMed Central

    Liu, Guohui; Liu, Xiaopeng; Qin, Zhifeng; Gu, Zhao; Wang, Guiyou; Shi, Weiru; Wen, Dongqing; Yu, Lihua; Luo, Yongchang; Xiao, Huajun

    2015-01-01

    Background: This study explores the responses of the cardiovascular system as humans exercise in an oxygen-enriched room at high altitude under various concentrations of CO2. Methods: The study utilized a hypobaric chamber set to the following specifications: 3800 m altitude with 25% O2 and different CO2 concentrations of 0.5% (C1), 3.0% (C2) and 5.0% (C3). Subjects exercised for 3 min three times, separated by 30 min resting periods in the above-mentioned conditions, at sea level (SL) and at 3800 m altitude (HA). The changes of heart rate variability, heart rate and blood pressure were analyzed. Results: Total power (TP) and high frequency power (HF) decreased notably during post-exercise at HA. HF increased prominently earlier the post-exercise period at 3800 m altitude with 25% O2 and 5.0% CO2 (C3), while low frequency power (LF) changed barely in all tests. The ratios of LF/HF were significantly higher during post-exercise in HA, and lower after high intensity exercise in C3. Heart rate and systolic blood pressure increased significantly in HA and C3. Conclusions: Parasympathetic activity dominated in cardiac autonomic modulation, and heart rate and blood pressure increased significantly after high intensity exercise in C3. PMID:26393634

  8. Evaluating cotton response to free-air carbon dioxide enrichment with canopy reflectance observations

    SciTech Connect

    Pinter, P.J. Jr.; Anderson, R.J.; Kimball, B.A.; Mauney, J.R.

    1992-12-31

    Most approaches for monitoring plant growth and development have serious drawbacks which limit their use in agricultural research programs. First of all, traditional methods for measuring above-ground green leaf area index (LAI) and biomass are very labor intensive, tedious and time consuming to execute. The size, number and frequency of samples required to characterize the plant canopy and detect statistically significant differences between treatments are usually large and often not practicable because of constraints on labor and space for cold storage and oven drying. Destructive sampling techniques are usually not appropriate in small research plots because the removal of some individuals from the population alters the response of remaining plants. Furthermore, the time required for physically separating leaves from stems and measuring them with a leaf area meter or waiting for tissues to dry in an oven precludes the use of these data in real-time decision making processes. Thus, important information that has immediate utility for assessing the efficacy of different treatments, identifying incipient problems, or guiding future sampling efforts is typically not available until several days or weeks after the samples have been collected. Non-invasive, remote sensing techniques which use plant canopy reflectance to monitor changes in canopy condition avoid these problems while providing scientists with an efficient tool for research and management of their projects. 19 refs., 9 figs., 10 tabs.

  9. Elevated carbon dioxide influences yield and photosynthetic responses of hydroponically-grown [correction of glown] sweetpotato.

    PubMed

    Mortley, D; Hill, J; Loretan, P; Bonsi, C; Hill, W; Hileman, D; Terse, A

    1996-12-01

    The response of 'TI-155' and 'Georgia Jet' sweetpotato cultivars to elevated CO2 concentrations of 400 (ambient), 750 and 1000 micromoles mol-1 were evaluated under controlled environment conditions using the nutrient film technique (NFT). Growth chamber conditions included photosynthetic photon flux (PPF) of 600 micromoles m-2 s-1, 14/10 light/dark period, and 70% +/- 5% RH. Plants were grown using a modified half-Hoagland nutrient solution with a pH range of 5.5-6.0 and an electrical conductivity of 0.12 S m-1. Gas exchange measurements were made using infrared gas analysis, an open-flow gas exchange system, and a controlled-climate cuvette. Photosynthetic (Pn) measurements were made at CO2 ranges of 50 to 1000 micromoles mol-1. Storage root yield/plant increased with CO2 up to 750 but declined at 1000 micromoles mol-1. Storage root dry matter (DM) and foliage dry weight increased with increasing CO2. Harvest index (HI) for both cultivars was highest at 750 micromoles mol-1. The PPF vs Pn curves were typical for C3 plants with saturation occurring at approximately 600 micromoles m-2 s-1. CO2 concentration did not significantly influence net Pn, transpiration, water-use-efficiency (WUE), and stomatal conductance. As measurement CO2 concentration increased, net Pn and WUE increased while transpiration and stomatal conductance decreased.

  10. Changes in nutritional metabolites of young ginger (Zingiber officinale Roscoe) in response to elevated carbon dioxide.

    PubMed

    Ghasemzadeh, Ali; Jaafar, Hawa Z E; Karimi, Ehsan; Ashkani, Sadegh

    2014-01-01

    The increase of atmospheric CO2 due to global climate change or horticultural practices has direct and indirect effects on food crop quality. One question that needs to be asked, is whether CO2 enrichment affects the nutritional quality of Malaysian young ginger plants. Responses of total carbohydrate, fructose, glucose, sucrose, protein, soluble amino acids and antinutrients to either ambient (400 μmol/mol) and elevated (800 μmol/mol) CO2 treatments were determined in the leaf and rhizome of two ginger varieties namely Halia Bentong and Halia Bara. Increasing of CO2 level from ambient to elevated resulted in increased content of total carbohydrate, sucrose, glucose, and fructose in the leaf and rhizome of ginger varieties. Sucrose was the major sugar followed by glucose and fructose in the leaf and rhizome extract of both varieties. Elevated CO2 resulted in a reduction of total protein content in the leaf (H. Bentong: 38.0%; H. Bara: 35.4%) and rhizome (H. Bentong: 29.0%; H. Bara: 46.2%). In addition, under CO2 enrichment, the concentration of amino acids increased by approximately 14.5% and 98.9% in H. Bentong and 12.0% and 110.3% in H. Bara leaf and rhizome, respectively. The antinutrient contents (cyanide and tannin) except phytic acid were influenced significantly (P ≤ 0.05) by CO2 concentration. Leaf extract of H. Bara exposed to elevated CO2 exhibited highest content of cyanide (336.1 mg HCN/kg DW), while, highest content of tannin (27.5 g/kg DW) and phytic acid (54.1 g/kg DW) were recorded from H.Bara rhizome grown under elevated CO2. These results demonstrate that the CO2 enrichment technique could improve content of some amino acids and antinutrients of ginger as a food crop by enhancing its nutritional and health-promoting properties.

  11. Response of cerebral blood flow to changes in carbon dioxide tension during hypothermic cardiopulmonary bypass

    SciTech Connect

    Prough, D.S.; Stump, D.A.; Roy, R.C.; Gravlee, G.P.; Williams, T.; Mills, S.A.; Hinshelwood, L.; Howard, G.

    1986-05-01

    Changes in cerebral blood flow (CBF) in response to changes in PaCO/sub 2/ were measured by intraaortic injection of /sup 133/Xe in 12 patients during hypothermic (23-30 degrees C) cardiopulmonary bypass. In each patient, CBF was determined at two randomly ordered levels of PaCO/sub 2/ obtained by varying the rate of gas inflow into the pump oxygenator (Group I, n = 6) or by varying the percentage of CO/sub 2/ added to the gas inflow (Group II, n = 6). Nasopharyngeal temperature, mean arterial pressure, pump-oxygenator flow, and hematocrit were maintained within a narrow range. In group I, a PaCO/sub 2/ (uncorrected for body temperature) of 36 +/- 4 mmHg (mean +/- SD) was associated with a CBF of 13 +/- 5 ml X 100 g-1 X min-1, while a PaCO/sub 2/ of 42 +/- 4 mmHg was associated with a CBF of 19 +/- 10 ml X 100 g-1 X min-1. In group II, a PaCO/sub 2/ of 47 +/- 3 mmHg was associated with a CBF of 20 +/- 8 ml X 100 g-1 X min-1, and a PaCO/sub 2/ of 53 +/- 3 mmHg was associated with a CBF of 26 +/- 9 ml X 100 g-1 X min-1. Within group I, the difference in CBF was significant (P less than 0.05); within group II, the difference in CBF was significant at the P less than 0.002 level. All CBF measurements were lower than those reported for normothermic, unanesthetized subjects of similar age.

  12. Changes in nutritional metabolites of young ginger (Zingiber officinale Roscoe) in response to elevated carbon dioxide.

    PubMed

    Ghasemzadeh, Ali; Jaafar, Hawa Z E; Karimi, Ehsan; Ashkani, Sadegh

    2014-01-01

    The increase of atmospheric CO2 due to global climate change or horticultural practices has direct and indirect effects on food crop quality. One question that needs to be asked, is whether CO2 enrichment affects the nutritional quality of Malaysian young ginger plants. Responses of total carbohydrate, fructose, glucose, sucrose, protein, soluble amino acids and antinutrients to either ambient (400 μmol/mol) and elevated (800 μmol/mol) CO2 treatments were determined in the leaf and rhizome of two ginger varieties namely Halia Bentong and Halia Bara. Increasing of CO2 level from ambient to elevated resulted in increased content of total carbohydrate, sucrose, glucose, and fructose in the leaf and rhizome of ginger varieties. Sucrose was the major sugar followed by glucose and fructose in the leaf and rhizome extract of both varieties. Elevated CO2 resulted in a reduction of total protein content in the leaf (H. Bentong: 38.0%; H. Bara: 35.4%) and rhizome (H. Bentong: 29.0%; H. Bara: 46.2%). In addition, under CO2 enrichment, the concentration of amino acids increased by approximately 14.5% and 98.9% in H. Bentong and 12.0% and 110.3% in H. Bara leaf and rhizome, respectively. The antinutrient contents (cyanide and tannin) except phytic acid were influenced significantly (P ≤ 0.05) by CO2 concentration. Leaf extract of H. Bara exposed to elevated CO2 exhibited highest content of cyanide (336.1 mg HCN/kg DW), while, highest content of tannin (27.5 g/kg DW) and phytic acid (54.1 g/kg DW) were recorded from H.Bara rhizome grown under elevated CO2. These results demonstrate that the CO2 enrichment technique could improve content of some amino acids and antinutrients of ginger as a food crop by enhancing its nutritional and health-promoting properties. PMID:25325154

  13. Response to 'Comment on 'Experimental observation of carbon dioxide reduction in exhaust gas from hydrocarbon fuel burning'' [Phys. Plasmas 17, 014701 (2010)

    SciTech Connect

    Uhm, Han S.; Kim, Chul H.

    2010-01-15

    A high-voltage cathode initiates an electron emission, resulting in a reduction in the carbon dioxide concentration in exhaust gas from the burning of hydrocarbon fuel. Assuming that the observed carbon dioxide reduction is originated from the molecular decomposition, the energy needed for the endothermic reaction of this carbon dioxide reduction may stem primarily from the internal energy reduction in the exhaust gas in accordance of the first law of the thermodynamics. An oxygen increase due to the reduction in carbon dioxide in a discharge gas was observed in real time.

  14. Silanediol-catalyzed carbon dioxide fixation.

    PubMed

    Hardman-Baldwin, Andrea M; Mattson, Anita E

    2014-12-01

    Carbon dioxide is an abundant and renewable C1 source. However, mild transformations with carbon dioxide at atmospheric pressure are difficult to accomplish. Silanediols have been discovered to operate as effective hydrogen-bond donor organocatalysts for the atom-efficient conversion of epoxides to cyclic carbonates under environmentally friendly conditions. The reaction system is tolerant of a variety of epoxides and the desired cyclic carbonates are isolated in excellent yields. PMID:25328125

  15. Carbon Dioxide for pH Control

    SciTech Connect

    Wagonner, R.C.

    2001-08-16

    Cardox, the major supplier of carbon dioxide, has developed a diffuser to introduce carbon dioxide into a water volume as small bubbles to minimize reagent loss to the atmosphere. This unit is integral to several configurations suggested for treatment to control alkalinity in water streams.

  16. Encapsulated liquid sorbents for carbon dioxide capture.

    PubMed

    Vericella, John J; Baker, Sarah E; Stolaroff, Joshuah K; Duoss, Eric B; Hardin, James O; Lewicki, James; Glogowski, Elizabeth; Floyd, William C; Valdez, Carlos A; Smith, William L; Satcher, Joe H; Bourcier, William L; Spadaccini, Christopher M; Lewis, Jennifer A; Aines, Roger D

    2015-02-05

    Drawbacks of current carbon dioxide capture methods include corrosivity, evaporative losses and fouling. Separating the capture solvent from infrastructure and effluent gases via microencapsulation provides possible solutions to these issues. Here we report carbon capture materials that may enable low-cost and energy-efficient capture of carbon dioxide from flue gas. Polymer microcapsules composed of liquid carbonate cores and highly permeable silicone shells are produced by microfluidic assembly. This motif couples the capacity and selectivity of liquid sorbents with high surface area to facilitate rapid and controlled carbon dioxide uptake and release over repeated cycles. While mass transport across the capsule shell is slightly lower relative to neat liquid sorbents, the surface area enhancement gained via encapsulation provides an order-of-magnitude increase in carbon dioxide absorption rates for a given sorbent mass. The microcapsules are stable under typical industrial operating conditions and may be used in supported packing and fluidized beds for large-scale carbon capture.

  17. Encapsulated liquid sorbents for carbon dioxide capture

    NASA Astrophysics Data System (ADS)

    Vericella, John J.; Baker, Sarah E.; Stolaroff, Joshuah K.; Duoss, Eric B.; Hardin, James O.; Lewicki, James; Glogowski, Elizabeth; Floyd, William C.; Valdez, Carlos A.; Smith, William L.; Satcher, Joe H.; Bourcier, William L.; Spadaccini, Christopher M.; Lewis, Jennifer A.; Aines, Roger D.

    2015-02-01

    Drawbacks of current carbon dioxide capture methods include corrosivity, evaporative losses and fouling. Separating the capture solvent from infrastructure and effluent gases via microencapsulation provides possible solutions to these issues. Here we report carbon capture materials that may enable low-cost and energy-efficient capture of carbon dioxide from flue gas. Polymer microcapsules composed of liquid carbonate cores and highly permeable silicone shells are produced by microfluidic assembly. This motif couples the capacity and selectivity of liquid sorbents with high surface area to facilitate rapid and controlled carbon dioxide uptake and release over repeated cycles. While mass transport across the capsule shell is slightly lower relative to neat liquid sorbents, the surface area enhancement gained via encapsulation provides an order-of-magnitude increase in carbon dioxide absorption rates for a given sorbent mass. The microcapsules are stable under typical industrial operating conditions and may be used in supported packing and fluidized beds for large-scale carbon capture.

  18. Carbon dioxide sequestration by mineral carbonation

    SciTech Connect

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

    2003-11-01

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

  19. Electrocatalysts for carbon dioxide conversion

    SciTech Connect

    Masel, Richard I; Salehi-Khojin, Amin

    2015-04-21

    Electrocatalysts for carbon dioxide conversion include at least one catalytically active element with a particle size above 0.6 nm. The electrocatalysts can also include a Helper Catalyst. The catalysts can be used to increase the rate, modify the selectivity or lower the overpotential of electrochemical conversion of CO.sub.2. Chemical processes and devices using the catalysts also include processes to produce CO, HCO.sup.-, H.sub.2CO, (HCO.sub.2).sup.-, H.sub.2CO.sub.2, CH.sub.3OH, CH.sub.4, C.sub.2H.sub.4, CH.sub.3CH.sub.2OH, CH.sub.3COO.sup.-, CH.sub.3COOH, C.sub.2H.sub.6, (COOH).sub.2, or (COO.sup.-).sub.2, and a specific device, namely, a CO.sub.2 sensor.

  20. Carbon dioxide cleaning pilot project

    SciTech Connect

    Knight, L.; Blackman, T.E.

    1994-01-21

    In 1989, radioactive-contaminated metal at the Rocky Flats Plant (RFP) was cleaned using a solvent paint stripper (Methylene chloride). One-third of the radioactive material was able to be recycled; two-thirds went to the scrap pile as low-level mixed waste. In addition, waste solvent solutions also required disposal. Not only was this an inefficient process, it was later prohibited by the Resource Conservation and Recovery Act (RCRA), 40 CFR 268. A better way of doing business was needed. In the search for a solution to this situation, it was decided to study the advantages of using a new technology - pelletized carbon dioxide cleaning. A proof of principle demonstration occurred in December 1990 to test whether such a system could clean radioactive-contaminated metal. The proof of principle demonstration was expanded in June 1992 with a pilot project. The purpose of the pilot project was three fold: (1) to clean metal so that it can satisfy free release criteria for residual radioactive contamination at the Rocky Flats Plant (RFP); (2) to compare two different carbon dioxide cleaning systems; and (3) to determine the cost-effectiveness of decontamination process in a production situation and compare the cost of shipping the metal off site for waste disposal. The pilot project was completed in August 1993. The results of the pilot project were: (1) 90% of those items which were decontaminated, successfully met the free release criteria , (2) the Alpheus Model 250 was selected to be used on plantsite and (3) the break even cost of decontaminating the metal vs shipping the contaminated material offsite for disposal was a cleaning rate of 90 pounds per hour, which was easily achieved.

  1. Use of the response of photosynthesis to oxygen to estimate mesophyll conductance to carbon dioxide in water-stressed soybean leaves

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several types of evidence indicate that there is a significant resistance to the movement of carbon dioxide from the substomatal air space to the site of fixation in the chloroplasts and that the resistance may vary with temperature, carbon dioxide concentration and water stress. Methods of estimat...

  2. Use of avoidance response by rainbow trout to carbon dioxide for fish self-transfer between tanks

    USGS Publications Warehouse

    Clingerman, J.; Bebak, J.; Mazik, P.M.; Summerfelt, S.T.

    2007-01-01

    Convenient, economical, and reduced labor fish harvest and transfer systems are required to realize operating cost savings that can be achieved with the use of much larger and deeper circular culture tanks. To achieve these goals, we developed a new technology for transferring fish based on their avoidance behavior to elevated concentrations of dissolved carbon dioxide (CO2). We observed this behavioral response during controlled, replicated experiments that showed dissolved CO2 concentrations of 60-120 mg/L induced rainbow trout (Oncorhynchus mykiss) to swim out of their 11 m3 "growout" tank, through a transfer pipe carrying a flow with ???23 mg/L dissolved CO2, into a second 11 m3 "harvest" tank. The research was conducted using separate groups of rainbow trout held at commercially relevant densities (40-60 kg/m3). The average weight of fish ranged from 0.15 to 1.3 kg during the various trials. In all trials that used a constant flow of low CO2 water (???23 mg/L) entering the growout tank from the harvest tank, approximately 80-90% of the fish swam from the growout tank, through the transfer pipe, and into the harvest tank after the CO2 concentration in the growout tank had exceeded 60 mg/L. The fish that remained in the growout tank stayed within the area of relatively low CO2 water at the entrance of the transfer pipe. However, the rate of fish transfer from the growout tank to the harvest tank was more than doubled when the diameter of the transfer pipe was increased from 203 to 406 mm. To consistently achieve fish transfer efficiencies of 99%, water flow rate through the fish transfer pipe had to be reduced to 10-20% of the original flow just before the conclusion of each trial. Reducing the flow of relatively low CO2 water near the end of each fish transfer event, restricted the zone of relatively low CO2 water about the entrance of the fish transfer pipe, and provided the stimulus for all but a few remaining fish to swim out of the growout tank. Results

  3. Hessian Fly (Diptera: Cecidomyiidae) Mortality in Export Bale Compressors and Response to a Hydrogen Phosphide and Carbon Dioxide Gas Mixture.

    PubMed

    Yokoyama, Victoria Y; Cambron, Sue E; Muhareb, Jeannette

    2015-02-01

    Hessian fly, Mayetiola destructor (Say), puparial mortality was evaluated in three modern hay compressors that produce compressed standard and large-size bales for export to Asia-Pacific countries. Pressure on bales ranged from 93.4 to 139.4 kg/cm2, causing 90.0-99.9% mortality of 10,891-23,164 puparia. Puparial response to a cylinderized hydrogen phosphide (1.8-2%) and carbon dioxide (97.8-98%) gas mixture was evaluated as a potential quarantine treatment using 2-4 d-exposures to low, medium, and high doses of 0.73-0.86, 1.05-1.26, and 1.39-1.56 mg/liter, and temperatures of 5.87±1.14, 9.84±0.05, 16.14±0.14, and 20.35±0.11°C. Accumulative concentration multiplied by time products (mg h/liter) at all fumigation temperatures for low, medium, and high fumigant doses were 34.9-37.7, 52.2-54.3, and 67.9-73.1 for 2 d; 52.7-60.6, 77.9-89.2, and 102.1-110.7 for 3 d; and 69.9-82.0, 99.4-118.2, and 132.3-146.8 for 4 d, respectively. An increase in mortality was significantly related to an increase in fumigation duration at 5, 10, and 15°C, and an increase in fumigant dose at 10 and 15°C. Puparial mortality ranged from 97.2 to 100% at all doses and durations at 20°C with no survivors at the highest dose for 3 d and the mid- and highest dose for 4 d. Bale compression is currently used in the first phase of a multiple quarantine treatment to control potential Hessian fly contaminants in exported hay. The novel fumigant may have application as a single quarantine treatment for noncompressed, standard exported bales.

  4. Hessian Fly (Diptera: Cecidomyiidae) Mortality in Export Bale Compressors and Response to a Hydrogen Phosphide and Carbon Dioxide Gas Mixture.

    PubMed

    Yokoyama, Victoria Y; Cambron, Sue E; Muhareb, Jeannette

    2015-02-01

    Hessian fly, Mayetiola destructor (Say), puparial mortality was evaluated in three modern hay compressors that produce compressed standard and large-size bales for export to Asia-Pacific countries. Pressure on bales ranged from 93.4 to 139.4 kg/cm2, causing 90.0-99.9% mortality of 10,891-23,164 puparia. Puparial response to a cylinderized hydrogen phosphide (1.8-2%) and carbon dioxide (97.8-98%) gas mixture was evaluated as a potential quarantine treatment using 2-4 d-exposures to low, medium, and high doses of 0.73-0.86, 1.05-1.26, and 1.39-1.56 mg/liter, and temperatures of 5.87±1.14, 9.84±0.05, 16.14±0.14, and 20.35±0.11°C. Accumulative concentration multiplied by time products (mg h/liter) at all fumigation temperatures for low, medium, and high fumigant doses were 34.9-37.7, 52.2-54.3, and 67.9-73.1 for 2 d; 52.7-60.6, 77.9-89.2, and 102.1-110.7 for 3 d; and 69.9-82.0, 99.4-118.2, and 132.3-146.8 for 4 d, respectively. An increase in mortality was significantly related to an increase in fumigation duration at 5, 10, and 15°C, and an increase in fumigant dose at 10 and 15°C. Puparial mortality ranged from 97.2 to 100% at all doses and durations at 20°C with no survivors at the highest dose for 3 d and the mid- and highest dose for 4 d. Bale compression is currently used in the first phase of a multiple quarantine treatment to control potential Hessian fly contaminants in exported hay. The novel fumigant may have application as a single quarantine treatment for noncompressed, standard exported bales. PMID:26470109

  5. Carbon dioxide capture process with regenerable sorbents

    DOEpatents

    Pennline, Henry W.; Hoffman, James S.

    2002-05-14

    A process to remove carbon dioxide from a gas stream using a cross-flow, or a moving-bed reactor. In the reactor the gas contacts an active material that is an alkali-metal compound, such as an alkali-metal carbonate, alkali-metal oxide, or alkali-metal hydroxide; or in the alternative, an alkaline-earth metal compound, such as an alkaline-earth metal carbonate, alkaline-earth metal oxide, or alkaline-earth metal hydroxide. The active material can be used by itself or supported on a substrate of carbon, alumina, silica, titania or aluminosilicate. When the active material is an alkali-metal compound, the carbon-dioxide reacts with the metal compound to generate bicarbonate. When the active material is an alkaline-earth metal, the carbon dioxide reacts with the metal compound to generate carbonate. Spent sorbent containing the bicarbonate or carbonate is moved to a second reactor where it is heated or treated with a reducing agent such as, natural gas, methane, carbon monoxide hydrogen, or a synthesis gas comprising of a combination of carbon monoxide and hydrogen. The heat or reducing agent releases carbon dioxide gas and regenerates the active material for use as the sorbent material in the first reactor. New sorbent may be added to the regenerated sorbent prior to subsequent passes in the carbon dioxide removal reactor.

  6. Response of marine and freshwater algae to nitric acid and elevated carbon dioxide levels simulating environmental effects of bolide impact

    NASA Technical Reports Server (NTRS)

    Boston, P. J.

    1988-01-01

    One of the intriguing facets of the Cretaceous-Tertiary extinction is the apparently selective pattern of mortality amongst taxa. Some groups of organisms were severely affected and some remained relatively unscathed as they went through the K/T boundary. While there is argument concerning the exact interpretation of the fossil record, one of the best documented extinctions at the Cretaceous-Tertiary boundary is that of the calcareous nannoplankton. These organisms include coccolithic algae and foraminiferans. Attempts to explain their decline at the K/T boundary center around chemistry which could affect their calcium carbonate shells while leaving their silica-shelled cousins less affected or unaffected. Two environmental consequences of an extraterrestrial body impact which were suggested are the production of large quantities of nitrogen oxides generated by the shock heating of the atmosphere and the possible rise in CO2 from the dissolution of CaCO3 shells. Both of these phenomena would acidify the upper layers of the oceans and bodies of freshwater not otherwise buffered. The effects of nitric acid, carbon dioxide, or both factors on the growth and reproduction of calcareous marine coccoliths and non-calcareous marine and freshwater species of algae were considered. These experiments demonstrate that nitric acid and carbon dioxide have significant effects on important aspects of the physiology and reproduction of modern algae representative of extinct taxa thought to have suffered significant declines at the Cretaceous-Tertiary boundary. Furthermore, calcareous species showed more marked effects than siliceous species and marine species tested were more sensitive than freshwater species.

  7. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    SciTech Connect

    K.A.M. Gasem; R.L. Robinson, Jr.; L.R. Radovic

    2001-06-15

    During the present reporting period, six complementary tasks involving experimentation, model development, and coal characterization were undertaken to meet our project objectives: (1) A second adsorption apparatus, utilizing equipment donated by BP Amoco, was assembled. Having confirmed the reliability of this additional experimental apparatus and procedures, adsorption isotherms for CO{sub 2}, methane, ethane, and nitrogen on wet Fruitland coal and on activated carbon were measured at 319.3 K (115 F) and pressures to 12.4 MPa (1800 psia). These measurements showed good agreement with our previous data and yielded an expected uncertainty of about 3%. The addition of this new facility has allowed us to essentially double our rate of data production. (2) Adsorption isotherms for pure CO{sub 2}, methane, and nitrogen on wet Illinois-6 coal and on activated carbon were measured at 319.3 K (115 F) and pressures to 12.4 MPa (1800 psia) on our first apparatus. The activated carbon measurements showed good agreement with literature data and with measurements obtained on our second apparatus. The expected uncertainty of the data is about 3%. The Illinois-6 adsorption measurements are a new addition to the existing database. Preparations are underway to measure adsorption isotherms for pure methane, carbon dioxide and nitrogen on DESC-8 coal. (3) Adsorption from binary mixtures of methane, nitrogen and CO{sub 2} at a series of compositions was also measured on the wet Fruitland coal at 319.3 K (115 F), using our first apparatus. The nominal compositions of these mixtures are 20%/80%, 40%/60%, 60%/40%, and 80%/20%. The experiments were conducted at pressures from 100 psia to 1800 psia. The expected uncertainty for these binary mixture data varies from 2 to 9%. (4) A study was completed to address the previously-reported rise in the CO{sub 2} absolute adsorption on wet Fruitland coal at 115 F and pressures exceeding 1200 psia. Our additional adsorption measurements on

  8. Transient response of the Hadley Centre coupled ocean-atmosphere model to increasing carbon dioxide. Part 3: Analysis of global-mean response using simple models

    SciTech Connect

    Murphy, J.M.

    1995-03-01

    The roles of surface, atmospheric, and oceanic feedbacks in controlling the global-mean transient response of a coupled ocean-atmosphere general circulation model (AOGCM) to increasing carbon dioxide are investigated. The analysis employs a four-box energy balance model (EBM) and an oceanic box-diffusion model (BDM) both tuned to the simulated general circulation model response. The land-sea contrast in the surface warming is explained almost entirely by the shortwave radiative feedbacks associated with changes in cloud and surface albedo. The oceanic thermal inertia delays the response; however, the initial delay is enhanced by increases in Anarctic sea-ice cover, which substantially reduce the effective climate sensitivity of the model in the first half of the 75-year experiment. When driven by the observed anthropogenic greenhouse forcing from the pre-industrial period to present day, the energy balance model overestimates the warming observed over land. However, inclusion of the direct forcing due to anthropogenic tropospheric sulphate aerosol eliminates the land/sea contrast in the response at 1990, leaving the simulated warming over land slightly below the observed value, although the rapid warming observed during the 1980s is well reproduced. The vertical penetration of the oceanic response is small below 1000 m. Within the top 1000 m the effective diffusivities are substantially enhanced by reduced convection and thermohaline overturning, driven by increased precipitation minus evaporation at high latitudes. These changes in ocean heat transport become significant after year 30, whereupon the effective oceanic heat capacity increases substantially, although this increase is partially offset by the effect of changes in the sea-ice margin.

  9. Growth, yield and plant water relationships in sweet potatoes in response to carbon dioxide enrichment: Progress report

    SciTech Connect

    Not Available

    1986-01-01

    In the summer of 1985, under the joint program of US Department of Energy, Carbon Dioxide Division, and Tuskegee University, experiments were conducted to study growth, yield, photosynthesis and plant water relationships in sweet potato plants grown in an enriched CO/sub 2/ environment. The main experiment utilized open top chambers to study the effects of CO/sub 2/ and soil moisture on growth, yield and photosynthesis of field-grown plants. In addition, potted plants in open top chambers were utilized in a study of the effects of different CO/sub 2/ concentrations on growth pattern, relative growth rate, net assimilation rate and biomass increment at different stages of development. The interaction effects of enriched CO/sub 2/ and water stress on biomass production, yield, xylem potential, and stomatal conductance were also investigated. 29 refs., 18 figs., 41 tabs.

  10. Responses of sugar maple and hemlock seedlings to elevated carbon dioxide under altered above- and belowground nitrogen sources.

    PubMed

    Eller, Allyson S D; McGuire, Krista L; Sparks, Jed P

    2011-04-01

    Various human-induced changes to the atmosphere have caused carbon dioxide (CO₂), nitrogen dioxide (NO₂) and nitrate deposition (NO₃⁻) to increase in many regions of the world. The goal of this study was to examine the simultaneous influence of these three factors on tree seedlings. We used open-top chambers to fumigate sugar maple (Acer saccharum) and eastern hemlock (Tsuga canadensis) with ambient or elevated CO₂ and NO₂ (elevated concentrations were 760 ppm and 40 ppb, respectively). In addition, we applied an artificial wet deposition of 30 kg ha⁻¹ year⁻¹ NO₃⁻ to half of the open-top chambers. After two growing seasons, hemlocks showed a stimulation of growth under elevated CO₂, but the addition of elevated NO₂ or NO₃⁻ eliminated this effect. In contrast, sugar maple seedlings showed no growth enhancement under elevated CO₂ alone and decreased growth in the presence of NO₂ or NO₃⁻, and the combined treatments of elevated CO₂ with increased NO₂ or NO₃⁻ were similar to control plants. Elevated CO₂ induced changes in the leaf characteristics of both species, including decreased specific leaf area, decreased %N and increased C:N. The effects of elevated CO₂, NO₂ and NO₃⁻ on growth were not additive and treatments that singly had no effect often modified the effects of other treatments. The growth of both maple and hemlock seedlings under the full combination of treatments (CO₂ + NO₂ + NO₃⁻) was similar to that of seedlings grown under control conditions, suggesting that models predicting increased seedling growth under future atmospheric conditions may be overestimating the growth and carbon storage potential of young trees.

  11. Response of a tundra ecosystem to elevated atmospheric carbon dioxide and CO{sub 2}-induced climate change. [Annual report

    SciTech Connect

    Oechel, W.C.

    1989-12-31

    Predicting the response of northern ecosystems to increases in atmospheric CO{sub 2} and associated climatic change is important for several reasons, including the fact that northern ecosystems contain large stores of carbon, most of which is below ground and because northern ecosystems could conceivably be either sources or sinks for CO{sub 2} under future climatic and atmospheric CO{sub 2} concentrations. The carbon in northern ecosystems is equal to about 20% of the world`s terrestrial carbon and about 70% of the carbon currently in the atmosphere. Eighty-three percent of this carbon is below ground in the seasonally-thawed upper soil layers and in the permanently frozen zone, the permafrost. Because of bogs and permafrost, northern ecosystems are unusual in that they can potentially store significant amounts of carbon over long time periods. Most other mature ecosystems have little capacity for long- term carbon storage. Given the right conditions, northern ecosystems can also release a significant amount of carbon. A substantial amount of the carbon stored in northern ecosystems, and much of the future storage potential, is in the tundra regions. These systems could conceivably act as sources or sinks depending on developing climatic and atmospheric conditions. Our recent work indicates that elevated CO{sub 2} alone will have little effect on carbon storage in the tundra. However, the combination of elevated atmospheric CO{sub 2} (+ 340 ppm) and air temperature (+4{degrees}C) in the absence of any change in soil water table or soil moisture content, should result in significant increases in carbon sequestering in the tundra. However, if changing climate results in a decrease in the water table and soil moisture levels, this may lead to sizeable losses of carbon from the tundra soils.

  12. Calcification and Growth of the Marine Coccolithophorid Emiliania huxleyi in Response to Elevated Partial Pressure of Carbon Dioxide and Low Phosphate Conditions

    NASA Astrophysics Data System (ADS)

    Faber, D. N.; Fabry, V. J.; Dickson, A. G.

    2004-12-01

    Atmospheric carbon dioxide (CO2) is expected to reach about 780 ppm by the year 2100, under the IS92a business-as-usual scenario. This expected increase will give rise to more than a threefold increase in surface ocean CO2 concentration, cause a drop in surface seawater pH of 0.4 units, and decrease the carbonate ion concentration by 55%, relative to pre-industrial values. Previous work demonstrated that the coccolithophorid Emiliania huxleyi shows a marked decrease in calcification rates in response to elevated CO2 under nutrient-replete and nitrogen-limited conditions. Here we investigate the response of E. huxleyi to increased pCO2 under phosphate limitation. Results from laboratory and mesocosm experiments indicate that E. huxleyi can outcompete other phytoplankton in communities that are under phosphate control. Moreover, E. huxleyi has higher calcification rates under phosphate limitation, and model studies suggest that low phosphate levels are necessary for E. huxleyi to form dense blooms in the NE Atlantic. We grew E. huxleyi cells in 8-L closed systems under low phosphate conditions at present day and elevated pCO2 concentrations. Cell growth, particulate inorganic carbon, particulate organic carbon, total alkalinity and total dissolved inorganic carbon were measured over time. Results will be discussed in relation to predicted changes in the oceanic CO2/carbonate system.

  13. Carbon dioxide conversion over carbon-based nanocatalysts.

    PubMed

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

    2013-07-01

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

  14. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for...) Each transport vehicle and freight container containing solid carbon dioxide must be...

  15. 46 CFR 76.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 3 2011-10-01 2011-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as... than 300 pounds of carbon dioxide, may have the cylinders located within the space protected. If...

  16. 46 CFR 108.627 - Carbon dioxide alarm.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide alarm. 108.627 Section 108.627 Shipping... EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide alarm. Each carbon dioxide alarm must be identified by marking: “WHEN ALARM SOUNDS VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED” next...

  17. 46 CFR 169.732 - Carbon dioxide alarm.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Carbon dioxide alarm. 169.732 Section 169.732 Shipping... Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide alarm. Each carbon dioxide alarm must be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.”...

  18. 46 CFR 76.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 3 2012-10-01 2012-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as... than 300 pounds of carbon dioxide, may have the cylinders located within the space protected. If...

  19. 46 CFR 108.626 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide warning signs. 108.626 Section 108.626... AND EQUIPMENT Equipment Markings and Instructions § 108.626 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  20. 46 CFR 97.37-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide warning signs. 97.37-11 Section 97.37-11... OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  1. 46 CFR 108.626 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide warning signs. 108.626 Section 108.626... AND EQUIPMENT Equipment Markings and Instructions § 108.626 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  2. 46 CFR 196.37-9 - Carbon dioxide alarm.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Carbon dioxide alarm. 196.37-9 Section 196.37-9 Shipping... Markings for Fire and Emergency Equipment, etc. § 196.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE...

  3. 46 CFR 97.37-9 - Carbon dioxide alarm.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9 Shipping... Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE...

  4. 46 CFR 169.732 - Carbon dioxide alarm.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide alarm. 169.732 Section 169.732 Shipping... Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide alarm. Each carbon dioxide alarm must be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.”...

  5. 46 CFR 193.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20... PROTECTION EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-20 Carbon dioxide...-5(d), consisting of not more than 300 pounds of carbon dioxide, may have cylinders located...

  6. 46 CFR 97.37-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide warning signs. 97.37-11 Section 97.37-11... OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  7. 46 CFR 193.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20... PROTECTION EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-20 Carbon dioxide...-5(d), consisting of not more than 300 pounds of carbon dioxide, may have cylinders located...

  8. 46 CFR 78.47-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 3 2012-10-01 2012-10-01 false Carbon dioxide warning signs. 78.47-11 Section 78.47-11... Fire and Emergency Equipment, Etc. § 78.47-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space into...

  9. 46 CFR 196.37-8 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Carbon dioxide warning signs. 196.37-8 Section 196.37-8... Markings for Fire and Emergency Equipment, etc. § 196.37-8 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space...

  10. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... permit the release of carbon dioxide gas to prevent a buildup of pressure that could rupture...

  11. 46 CFR 78.47-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 3 2014-10-01 2014-10-01 false Carbon dioxide warning signs. 78.47-11 Section 78.47-11... Fire and Emergency Equipment, Etc. § 78.47-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space into...

  12. 46 CFR 78.47-9 - Carbon dioxide alarm.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Carbon dioxide alarm. 78.47-9 Section 78.47-9 Shipping... and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.” (b)...

  13. 46 CFR 108.627 - Carbon dioxide alarm.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide alarm. 108.627 Section 108.627 Shipping... EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide alarm. Each carbon dioxide alarm must be identified by marking: “WHEN ALARM SOUNDS VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED” next...

  14. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... permit the release of carbon dioxide gas to prevent a buildup of pressure that could rupture...

  15. 46 CFR 193.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 193.15-20 Carbon dioxide storage. (a...), consisting of not more than 300 pounds of carbon dioxide, may have cylinders located within the...

  16. 46 CFR 131.817 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide warning signs. 131.817 Section 131.817... Markings for Fire Equipment and Emergency Equipment § 131.817 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  17. 46 CFR 78.47-9 - Carbon dioxide alarm.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 3 2011-10-01 2011-10-01 false Carbon dioxide alarm. 78.47-9 Section 78.47-9 Shipping... and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.” (b)...

  18. 46 CFR 196.37-9 - Carbon dioxide alarm.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide alarm. 196.37-9 Section 196.37-9 Shipping... Markings for Fire and Emergency Equipment, etc. § 196.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE...

  19. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... permit the release of carbon dioxide gas to prevent a buildup of pressure that could rupture...

  20. 46 CFR 193.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 193.15-20 Carbon dioxide storage. (a...), consisting of not more than 300 pounds of carbon dioxide, may have cylinders located within the...

  1. 46 CFR 78.47-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 3 2013-10-01 2013-10-01 false Carbon dioxide warning signs. 78.47-11 Section 78.47-11... Fire and Emergency Equipment, Etc. § 78.47-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space into...

  2. 46 CFR 108.626 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide warning signs. 108.626 Section 108.626... AND EQUIPMENT Equipment Markings and Instructions § 108.626 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  3. 46 CFR 196.37-8 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Carbon dioxide warning signs. 196.37-8 Section 196.37-8... Markings for Fire and Emergency Equipment, etc. § 196.37-8 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space...

  4. 46 CFR 97.37-9 - Carbon dioxide alarm.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9 Shipping... Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE...

  5. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... permit the release of carbon dioxide gas to prevent a buildup of pressure that could rupture...

  6. 46 CFR 131.817 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide warning signs. 131.817 Section 131.817... Markings for Fire Equipment and Emergency Equipment § 131.817 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  7. 46 CFR 95.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a... of not more than 300 pounds of carbon dioxide, may have the cylinders located within the...

  8. 46 CFR 97.37-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide warning signs. 97.37-11 Section 97.37-11... OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  9. 46 CFR 95.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a... of not more than 300 pounds of carbon dioxide, may have the cylinders located within the...

  10. 46 CFR 196.37-8 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Carbon dioxide warning signs. 196.37-8 Section 196.37-8... Markings for Fire and Emergency Equipment, etc. § 196.37-8 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space...

  11. 46 CFR 76.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as... than 300 pounds of carbon dioxide, may have the cylinders located within the space protected. If...

  12. 46 CFR 95.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a... of not more than 300 pounds of carbon dioxide, may have the cylinders located within the...

  13. 46 CFR 95.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a... of not more than 300 pounds of carbon dioxide, may have the cylinders located within the...

  14. 46 CFR 76.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 3 2014-10-01 2014-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as... than 300 pounds of carbon dioxide, may have the cylinders located within the space protected. If...

  15. 46 CFR 95.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a... of not more than 300 pounds of carbon dioxide, may have the cylinders located within the...

  16. 46 CFR 131.817 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide warning signs. 131.817 Section 131.817... Markings for Fire Equipment and Emergency Equipment § 131.817 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  17. 46 CFR 193.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20... PROTECTION EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-20 Carbon dioxide...-5(d), consisting of not more than 300 pounds of carbon dioxide, may have cylinders located...

  18. 46 CFR 76.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 3 2013-10-01 2013-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as... than 300 pounds of carbon dioxide, may have the cylinders located within the space protected. If...

  19. Silver oxide sorbent for carbon dioxide

    NASA Technical Reports Server (NTRS)

    Colombo, G. V.

    1974-01-01

    Material can be regenerated at least 20 times by heating at 250 C. Sorbent is compatible with environment of high humidity; up to 20% by weight of carbon dioxide can be absorbed. Material is prepared from silver carbonate, potassium hydroxide or carbonate, and sodium silicate.

  20. Carbon dioxide dialysis will save the lung.

    PubMed

    Pesenti, Antonio; Patroniti, Nicolò; Fumagalli, Roberto

    2010-10-01

    Mechanical ventilation and ventilator-associated lung injury could be avoided by decreasing the ventilatory needs of the patient by extracorporeal carbon dioxide removal. The reasons for the increased ventilatory needs of the patients with acute respiratory distress syndrome are outlined, as well as some of the mechanisms of continuing damage. Extracorporeal gas exchange has been used mainly as a rescue procedure for severely hypoxic patients. Although this indication remains valid, we propose that extracorporeal carbon dioxide removal could control the ventilatory needs of the patient and allow the maintenance of spontaneous breathing while avoiding intubation and decreasing the concurrent sedation needs. A scenario is depicted whereby an efficient carbon dioxide removal device can maintain blood gas homeostasis of the patient with invasiveness comparable to hemodialysis. High carbon dioxide removal efficiency may be achieved by combinations of hemofiltration and metabolizable acid loads.

  1. Carbon dioxide-soluble polymers and swellable polymers for carbon dioxide applications

    DOEpatents

    DeSimone, Joseph M.; Birnbaum, Eva; Carbonell, Ruben G.; Crette, Stephanie; McClain, James B.; McCleskey, T. Mark; Powell, Kimberly R.; Romack, Timothy J.; Tumas, William

    2004-06-08

    A method for carrying out a catalysis reaction in carbon dioxide comprising contacting a fluid mixture with a catalyst bound to a polymer, the fluid mixture comprising at least one reactant and carbon dioxide, wherein the reactant interacts with the catalyst to form a reaction product. A composition of matter comprises carbon dioxide and a polymer and a reactant present in the carbon dioxide. The polymer has bound thereto a catalyst at a plurality of chains along the length of the polymer, and wherein the reactant interacts with the catalyst to form a reaction product.

  2. Responses of soil respiration to elevated carbon dioxide and nitrogen addition in young subtropical forest ecosystems in China

    NASA Astrophysics Data System (ADS)

    Deng, Q.; Zhou, G.; Liu, J.; Liu, S.; Duan, H.; Zhang, D.

    2010-01-01

    Global climate change in the real world always exhibits simultaneous changes in multiple factors. Prediction of ecosystem responses to multi-factor global changes in a future world strongly relies on our understanding of their interactions. However, it is still unclear how nitrogen (N) deposition and elevated atmospheric carbon dioxide concentration [CO2] would interactively influence forest floor soil respiration in subtropical China. We assessed the main and interactive effects of elevated [CO2] and N addition on soil respiration by growing tree seedlings in ten large open-top chambers under CO2 (ambient CO2 and 700 μmol mol-1) and nitrogen (ambient and 100 kg N ha-1 yr-1) treatments. Soil respiration, soil temperature and soil moisture were measured for 30 months, as well as above-ground biomass, root biomass and soil organic matter (SOM). Results showed that soil respiration displayed strong seasonal patterns with higher values observed in the wet season (April-September) and lower values in the dry season (October-March) in all treatments. Significant exponential relationships between soil respiration rates and soil temperatures, as well as significant linear relationships between soil respiration rates and soil moistures (below 15%) were found. Both CO2 and N treatments significantly affected soil respiration, and there was significant interaction between elevated [CO2] and N addition (p<0.001, p=0.003, and p=0.006, respectively). We also observed that the stimulatory effect of individual elevated [CO2] (about 29% increased) was maintained throughout the experimental period. The positive effect of N addition was found only in 2006 (8.17% increased), and then had been weakened over time. Their combined effect on soil respiration (about 50% increased) was greater than the impact of either one alone. Mean value of annual soil respiration was 5.32 ± 0.08, 4.54 ± 0.10, 3.56 ± 0.03 and 3.53 ± 0.03 kg CO2 m-2 yr-1 in the chambers exposed to elevated [CO2] and

  3. Mineralization strategies for carbon dioxide sequestration

    SciTech Connect

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

    2003-01-01

    Progress is reported in three primary research areas--each concerned with sequestering carbon dioxide into mineral matrices. Direct mineral carbonation was pioneered at Albany Research Center. The method treats the reactant, olivine or serpentine in aqueous media with carbon dioxide at high temperature and pressure to form stable mineral carbonates. Recent results are introduced for pretreatment by high-intensity grinding to improve carbonation efficiency. To prove feasibility of the carbonation process, a new reactor was designed and operated to progress from batch tests to continuous operation. The new reactor is a prototype high-temperature, high-pressure flow loop reactor that will furnish information on flow, energy consumption, and wear and corrosion resulting from slurry flow and the carbonation reaction. A promising alternative mineralization approach is also described. New data are presented for long-term exposure of carbon dioxide to Colombia River Basalt to determine the extent of conversion of carbon dioxide to permanent mineral carbonates. Batch autoclave tests were conducted using drill-core samples of basalt and reacted under conditions that simulate in situ injection into basalt-containing geological formations.

  4. Turning carbon dioxide into fuel.

    PubMed

    Jiang, Z; Xiao, T; Kuznetsov, V L; Edwards, P P

    2010-07-28

    Our present dependence on fossil fuels means that, as our demand for energy inevitably increases, so do emissions of greenhouse gases, most notably carbon dioxide (CO2). To avoid the obvious consequences on climate change, the concentration of such greenhouse gases in the atmosphere must be stabilized. But, as populations grow and economies develop, future demands now ensure that energy will be one of the defining issues of this century. This unique set of (coupled) challenges also means that science and engineering have a unique opportunity-and a burgeoning challenge-to apply their understanding to provide sustainable energy solutions. Integrated carbon capture and subsequent sequestration is generally advanced as the most promising option to tackle greenhouse gases in the short to medium term. Here, we provide a brief overview of an alternative mid- to long-term option, namely, the capture and conversion of CO2, to produce sustainable, synthetic hydrocarbon or carbonaceous fuels, most notably for transportation purposes. Basically, the approach centres on the concept of the large-scale re-use of CO2 released by human activity to produce synthetic fuels, and how this challenging approach could assume an important role in tackling the issue of global CO2 emissions. We highlight three possible strategies involving CO2 conversion by physico-chemical approaches: sustainable (or renewable) synthetic methanol, syngas production derived from flue gases from coal-, gas- or oil-fired electric power stations, and photochemical production of synthetic fuels. The use of CO2 to synthesize commodity chemicals is covered elsewhere (Arakawa et al. 2001 Chem. Rev. 101, 953-996); this review is focused on the possibilities for the conversion of CO2 to fuels. Although these three prototypical areas differ in their ultimate applications, the underpinning thermodynamic considerations centre on the conversion-and hence the utilization-of CO2. Here, we hope to illustrate that advances

  5. Turning carbon dioxide into fuel.

    PubMed

    Jiang, Z; Xiao, T; Kuznetsov, V L; Edwards, P P

    2010-07-28

    Our present dependence on fossil fuels means that, as our demand for energy inevitably increases, so do emissions of greenhouse gases, most notably carbon dioxide (CO2). To avoid the obvious consequences on climate change, the concentration of such greenhouse gases in the atmosphere must be stabilized. But, as populations grow and economies develop, future demands now ensure that energy will be one of the defining issues of this century. This unique set of (coupled) challenges also means that science and engineering have a unique opportunity-and a burgeoning challenge-to apply their understanding to provide sustainable energy solutions. Integrated carbon capture and subsequent sequestration is generally advanced as the most promising option to tackle greenhouse gases in the short to medium term. Here, we provide a brief overview of an alternative mid- to long-term option, namely, the capture and conversion of CO2, to produce sustainable, synthetic hydrocarbon or carbonaceous fuels, most notably for transportation purposes. Basically, the approach centres on the concept of the large-scale re-use of CO2 released by human activity to produce synthetic fuels, and how this challenging approach could assume an important role in tackling the issue of global CO2 emissions. We highlight three possible strategies involving CO2 conversion by physico-chemical approaches: sustainable (or renewable) synthetic methanol, syngas production derived from flue gases from coal-, gas- or oil-fired electric power stations, and photochemical production of synthetic fuels. The use of CO2 to synthesize commodity chemicals is covered elsewhere (Arakawa et al. 2001 Chem. Rev. 101, 953-996); this review is focused on the possibilities for the conversion of CO2 to fuels. Although these three prototypical areas differ in their ultimate applications, the underpinning thermodynamic considerations centre on the conversion-and hence the utilization-of CO2. Here, we hope to illustrate that advances

  6. Carbon Dioxide Effects Research and Assessment Program: Proceedings of the carbon dioxide and climate research program conference

    SciTech Connect

    Schmitt, L E

    1980-12-01

    Papers presented at the Carbon Dioxide and Climate Research Program Conference are included in this volume. Topics discussed are: the carbon cycle; modeling the carbon system; climatic response due to increased CO2; climate modeling; the use of paleoclimatic data in understanding climate change; attitudes and implications of CO2; social responses to the CO2 problem; a scenario for atmospheric CO2 to 2025; marine photosynthesis and the global carbon cycle; and the role of tropical forests in the carbon balance of the world. Separate abstracts of nine papers have been prepared for inclusion in the Energy Data Base. (RJC)

  7. Multiple-century response of a coupled ocean-atmosphere model to an increase of atmospheric carbon dioxide

    SciTech Connect

    Manabe, S.; Stouffer, R.J. )

    1994-01-01

    To speculate on the future change of climate over several centuries, three 500-year integrations of a coupled ocean-atmosphere model were performed. In addition, to the standard integration in which the atmospheric concentration of carbon dioxide remains unchanged, two integrations are conducted. In one integration, the CO[sub 2] concentration increases by 1% yr[sup [minus]1] (compounded) until it reaches four times the initial value at the 140th year and remains unchanged thereafter. In another integration, the CO[sub 2] concentration also increases at the rate of 1% yr[sup [minus]1] until it reaches twice the initial value of the 70th year and remains unchanged thereafter. One of the most notable features of the CO[sub 2]-quadrupoling integration is the gradual disappearance of thermohaline circulations in most of the model oceans during the first 250-year period, leaving behind wind-driven cells. For example, thermohaline circulation nearly vanished in the North Atlantic during the first 200 years of the integration. In the Weddell and Ross seas, thermohaline circulation becomes weaker and shallower, thereby reducing the rate of bottom water formation and weakening the northward flow of bottom water in the Pacific and Atlantic oceans. The weakening or near disappearance of thermohaline circulation described above is attributable mainly to the capping of the model oceans by relatively fresh water in high latitudes where the excess of precipitation over evaporation increases markedly due to the enhanced poleward moisture transport in the warmer model troposphere.

  8. Matrix effects in nilotinib formulations with pH-responsive polymer produced by carbon dioxide-mediated precipitation.

    PubMed

    Colombo, Stefano; Brisander, Magnus; Haglöf, Jakob; Sjövall, Peter; Andersson, Per; Østergaard, Jesper; Malmsten, Martin

    2015-10-15

    Factors determining the pH-controlled dissolution kinetics of nilotinib formulations with the pH-titrable polymer hydroxypropyl methylcellulose phthalate, obtained by carbon dioxide-mediated precipitation, were mechanistically examined in acid and neutral environment. The matrix effect, modulating the drug dissolution, was characterized with a battery of physicochemical methodologies, including ToF-SIMS for surface composition, SAXS/WAXS and modulated DSC for crystallization characterization, and simultaneous UV-imaging and Raman spectroscopy for monitoring the dissolution process in detail. The hybrid particle formulations investigated consisted of amorphous nilotinib embedded in a polymer matrix in single continuous phase, displaying extended retained amorphicity also under wet conditions. It was demonstrated by Raman and FTIR spectroscopy that the efficient drug dispersion and amorphization in the polymer matrix were mediated by hydrogen bonding between the drug and the phthalate groups on the polymer. Simultaneous Raman and UV-imaging studies of the effect of drug load on the swelling and dissolution of the polymer matrix revealed that high nilotinib load prevented matrix swelling on passage from acid to neutral pH, thereby preventing re-precipitation and re-crystallization of incorporated nilotinib. These findings provide a mechanistic foundation of formulation development of nilotinib and other protein kinase inhibitors, which are now witnessing an intense therapeutic and industrial attention due to the difficulty in formulating these compounds so that efficient oral bioavailability is reached.

  9. Inter and intra-specific variation in photosynthetic acclimation response to long term exposure of elevated carbon dioxide

    SciTech Connect

    Wilkinson, M. |

    1996-08-01

    The response of intra and interspecific variation in photosynthetic acclimation to growth at elevated atmospheric CO{sub 2} concentration (600{micro}mol mol-l) in six important grassland species was investigated. Plants were grown in a background sward of Lolium perenne and measurements were made after four years of growth at elevated C{sub a}. Elevated CO{sub 2} was maintained using a FACE (Free-Air Carbon Enrichment) system. Significant intra and interspecific variation in acclimation response was demonstrated. The response of adaxial and abaxial stomatal conductance to elevated CO{sub 2} was also investigated. The stomatal conductance of both the adaxial and abaxial leaf surfaces was found to be reduced by elevated C{sub a}. Significant asymmetric responses in stomatal conductance was demonstrated in D. glomerata and T. pratense. Analysis of stomatal indices and densities indicated that the observed reductions in stomatal conductance were probably the result of changes in stomatal aperture.

  10. Method for Extracting and Sequestering Carbon Dioxide

    SciTech Connect

    Rau, Gregory H.; Caldeira, Kenneth G.

    2005-05-10

    A method and apparatus to extract and sequester carbon dioxide (CO2) from a stream or volume of gas wherein said method and apparatus hydrates CO2, and reacts the resulting carbonic acid with carbonate. Suitable carbonates include, but are not limited to, carbonates of alkali metals and alkaline earth metals, preferably carbonates of calcium and magnesium. Waste products are metal cations and bicarbonate in solution or dehydrated metal salts, which when disposed of in a large body of water provide an effective way of sequestering CO2 from a gaseous environment.

  11. Method for extracting and sequestering carbon dioxide

    DOEpatents

    Rau, Gregory H.; Caldeira, Kenneth G.

    2005-05-10

    A method and apparatus to extract and sequester carbon dioxide (CO.sub.2) from a stream or volume of gas wherein said method and apparatus hydrates CO.sub.2, and reacts the resulting carbonic acid with carbonate. Suitable carbonates include, but are not limited to, carbonates of alkali metals and alkaline earth metals, preferably carbonates of calcium and magnesium. Waste products are metal cations and bicarbonate in solution or dehydrated metal salts, which when disposed of in a large body of water provide an effective way of sequestering CO.sub.2 from a gaseous environment.

  12. Apparatus for extracting and sequestering carbon dioxide

    DOEpatents

    Rau, Gregory H.; Caldeira, Kenneth G.

    2010-02-02

    An apparatus and method associated therewith to extract and sequester carbon dioxide (CO.sub.2) from a stream or volume of gas wherein said apparatus hydrates CO.sub.2 and reacts the resulting carbonic acid with carbonate. Suitable carbonates include, but are not limited to, carbonates of alkali metals and alkaline earth metals, preferably carbonates of calcium and magnesium. Waste products are metal cations and bicarbonate in solution or dehydrated metal salts, which when disposed of in a large body of water provide an effective way of sequestering CO.sub.2 from a gaseous environment.

  13. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    SciTech Connect

    K.A.M. Gasem; R.L. Robinson, Jr.; J.E. Fitzgerald; Z. Pan; M. Sudibandriyo

    2003-04-30

    The authors' long-term goal is to develop accurate prediction methods for describing the adsorption behavior of gas mixtures on solid adsorbents over complete ranges of temperature, pressure, and adsorbent types. The originally-stated, major objectives of the current project are to: (1) measure the adsorption behavior of pure CO{sub 2}, methane, nitrogen, and their binary and ternary mixtures on several selected coals having different properties at temperatures and pressures applicable to the particular coals being studied, (2) generalize the adsorption results in terms of appropriate properties of the coals to facilitate estimation of adsorption behavior for coals other than those studied experimentally, (3) delineate the sensitivity of the competitive adsorption of CO{sub 2}, methane, and nitrogen to the specific characteristics of the coal on which they are adsorbed; establish the major differences (if any) in the nature of this competitive adsorption on different coals, and (4) test and/or develop theoretically-based mathematical models to represent accurately the adsorption behavior of mixtures of the type for which measurements are made. As this project developed, an important additional objective was added to the above original list. Namely, we were encouraged to interact with industry and/or governmental agencies to utilize our expertise to advance the state of the art in coalbed adsorption science and technology. As a result of this additional objective, we participated with the Department of Energy and industry in the measurement and analysis of adsorption behavior as part of two distinct investigations. These include (a) Advanced Resources International (ARI) DOE Project DE-FC26-00NT40924, ''Adsorption of Pure Methane, Nitrogen, and Carbon Dioxide and Their Mixtures on Wet Tiffany Coal'', and (b) the DOE-NETL Project, ''Round Robin: CO{sub 2} Adsorption on Selected Coals''. These activities, contributing directly to the DOE projects listed above, also

  14. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    SciTech Connect

    K.A.M. Gasem; R.L. Robinson, Jr.; L.R. Radovic

    2003-03-10

    The authors' long-term goal is to develop accurate prediction methods for describing the adsorption behavior of gas mixtures on solid adsorbents over complete ranges of temperature, pressure and adsorbent types. The originally-stated, major objectives of the current project are to (1) measure the adsorption behavior of pure CO{sub 2}, methane, nitrogen, and their binary and ternary mixtures on several selected coals having different properties at temperatures and pressures applicable to the particular coals being studied, (2) generalize the adsorption results in terms of appropriate properties of the coals to facilitate estimation of adsorption behavior for coals other than those studied experimentally, (3) delineate the sensitivity of the competitive adsorption of CO{sub 2}, methane and nitrogen to the specific characteristics of the coal on which they are adsorbed; establish the major differences (if any) in the nature of this competitive adsorption on different coals, and (4) test and/or develop theoretically-based mathematical models to represent accurately the adsorption behavior of mixtures of the type for which measurements are made. As this project has developed, an important additional objective has been added to the above original list. Namely, we have been encouraged to interact with industry and/or governmental agencies to utilize our expertise to advance the state of the art in coalbed adsorption science and technology. As a result of this additional objective, we have participated with the Department of Energy and industry in the measurement and analysis of adsorption behavior as part of two distinct investigations. These include (a) Advanced Resources International (ARI) DOE Project DE-FC26-00NT40924, ''Adsorption of Pure Methane, Nitrogen, and Carbon Dioxide and Their Mixtures on Wet Tiffany Coal'', and (b) the DOE-NETL Project, ''Round Robin: CO{sub 2} Adsorption on Selected Coals''. These activities, contributing directly to the DOE projects

  15. Carbon dioxide control in an open system that measures canopy gas exchanges

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Atmospheric carbon dioxide concentration affects both C3 carbon net assimilation as well as crop water use. Methods for measuring whole canopy gas exchange responses under carbon dioxide enrichment are needed for breeding programs aiming to develop crop cultivars resistant to stresses like drought i...

  16. Acute carbon dioxide avoidance in Caenorhabditis elegans.

    PubMed

    Hallem, Elissa A; Sternberg, Paul W

    2008-06-10

    Carbon dioxide is produced as a by-product of cellular respiration by all aerobic organisms and thus serves for many animals as an important indicator of food, mates, and predators. However, whether free-living terrestrial nematodes such as Caenorhabditis elegans respond to CO2 was unclear. We have demonstrated that adult C. elegans display an acute avoidance response upon exposure to CO2 that is characterized by the cessation of forward movement and the rapid initiation of backward movement. This response is mediated by a cGMP signaling pathway that includes the cGMP-gated heteromeric channel TAX-2/TAX-4. CO2 avoidance is modulated by multiple signaling molecules, including the neuropeptide Y receptor NPR-1 and the calcineurin subunits TAX-6 and CNB-1. Nutritional status also modulates CO2 responsiveness via the insulin and TGFbeta signaling pathways. CO2 response is mediated by a neural circuit that includes the BAG neurons, a pair of sensory neurons of previously unknown function. TAX-2/TAX-4 function in the BAG neurons to mediate acute CO2 avoidance. Our results demonstrate that C. elegans senses and responds to CO2 using multiple signaling pathways and a neural network that includes the BAG neurons and that this response is modulated by the physiological state of the worm.

  17. Acute carbon dioxide avoidance in Caenorhabditis elegans.

    PubMed

    Hallem, Elissa A; Sternberg, Paul W

    2008-06-10

    Carbon dioxide is produced as a by-product of cellular respiration by all aerobic organisms and thus serves for many animals as an important indicator of food, mates, and predators. However, whether free-living terrestrial nematodes such as Caenorhabditis elegans respond to CO2 was unclear. We have demonstrated that adult C. elegans display an acute avoidance response upon exposure to CO2 that is characterized by the cessation of forward movement and the rapid initiation of backward movement. This response is mediated by a cGMP signaling pathway that includes the cGMP-gated heteromeric channel TAX-2/TAX-4. CO2 avoidance is modulated by multiple signaling molecules, including the neuropeptide Y receptor NPR-1 and the calcineurin subunits TAX-6 and CNB-1. Nutritional status also modulates CO2 responsiveness via the insulin and TGFbeta signaling pathways. CO2 response is mediated by a neural circuit that includes the BAG neurons, a pair of sensory neurons of previously unknown function. TAX-2/TAX-4 function in the BAG neurons to mediate acute CO2 avoidance. Our results demonstrate that C. elegans senses and responds to CO2 using multiple signaling pathways and a neural network that includes the BAG neurons and that this response is modulated by the physiological state of the worm. PMID:18524955

  18. Designed amyloid fibers as materials for selective carbon dioxide capture.

    PubMed

    Li, Dan; Furukawa, Hiroyasu; Deng, Hexiang; Liu, Cong; Yaghi, Omar M; Eisenberg, David S

    2014-01-01

    New materials capable of binding carbon dioxide are essential for addressing climate change. Here, we demonstrate that amyloids, self-assembling protein fibers, are effective for selective carbon dioxide capture. Solid-state NMR proves that amyloid fibers containing alkylamine groups reversibly bind carbon dioxide via carbamate formation. Thermodynamic and kinetic capture-and-release tests show the carbamate formation rate is fast enough to capture carbon dioxide by dynamic separation, undiminished by the presence of water, in both a natural amyloid and designed amyloids having increased carbon dioxide capacity. Heating to 100 °C regenerates the material. These results demonstrate the potential of amyloid fibers for environmental carbon dioxide capture.

  19. Polymers for metal extractions in carbon dioxide

    DOEpatents

    DeSimone, Joseph M.; Tumas, William; Powell, Kimberly R.; McCleskey, T. Mark; Romack, Timothy J.; McClain, James B.; Birnbaum, Eva R.

    2001-01-01

    A composition useful for the extraction of metals and metalloids comprises (a) carbon dioxide fluid (preferably liquid or supercritical carbon dioxide); and (b) a polymer in the carbon dioxide, the polymer having bound thereto a ligand that binds the metal or metalloid; with the ligand bound to the polymer at a plurality of locations along the chain length thereof (i.e., a plurality of ligands are bound at a plurality of locations along the chain length of the polymer). The polymer is preferably a copolymer, and the polymer is preferably a fluoropolymer such as a fluoroacrylate polymer. The extraction method comprises the steps of contacting a first composition containing a metal or metalloid to be extracted with a second composition, the second composition being as described above; and then extracting the metal or metalloid from the first composition into the second composition.

  20. 21 CFR 868.1400 - Carbon dioxide gas analyzer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon...

  1. 21 CFR 868.1400 - Carbon dioxide gas analyzer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon...

  2. 21 CFR 868.1400 - Carbon dioxide gas analyzer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon...

  3. 21 CFR 868.1400 - Carbon dioxide gas analyzer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon...

  4. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Carbon dioxide, refrigerated liquid. 179.102-1... Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated liquid... anchorage of tanks must be made of carbon steel conforming to ASTM A 516/A 516M (IBR, see § 171.7 of...

  5. 21 CFR 868.1400 - Carbon dioxide gas analyzer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon...

  6. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Carbon dioxide, refrigerated liquid. 179.102-1... Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated liquid... anchorage of tanks must be made of carbon steel conforming to ASTM A 516/A 516M (IBR, see § 171.7 of...

  7. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Carbon dioxide, refrigerated liquid. 179.102-1... Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated liquid... anchorage of tanks must be made of carbon steel conforming to ASTM A 516/A 516M (IBR, see § 171.7 of...

  8. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Carbon dioxide, refrigerated liquid. 179.102-1... Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated liquid... anchorage of tanks must be made of carbon steel conforming to ASTM A 516/A 516M (IBR, see § 171.7 of...

  9. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Carbon dioxide, refrigerated liquid. 179.102-1...) § 179.102-1 Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide... and anchorage of tanks must be made of carbon steel conforming to ASTM A 516/A 516M (IBR, see §...

  10. Numerical Simulation of Extent of Carbon Dioxide Plume Injected in the Gyeongsang Basin, Korea

    NASA Astrophysics Data System (ADS)

    Kihm, J.; Park, S.; Kim, J.

    2012-12-01

    A series of thermo-hydro-chemical numerical simulations was performed to evaluate extent of carbon dioxide plume injected in the Gyeongsang Basin, which is one of the prospective onshore sedimentary basins for geologic storage of carbon dioxide in Korea. The carbon dioxide plume extent is an important factor in estimating storage efficiency and thus storage capacity of carbon dioxide in a storage formation because it represents an actual volume of the storage formation, which is occupied by injected carbon dioxide. The carbon dioxide plume extent is also an essential component in risk analysis of geologic storage of carbon dioxide because most of thermo-hydro-mechanical-chemical responses to carbon dioxide injection occur within it. To evaluate impacts of injection scenarios (i.e., injection rate and period) of carbon dioxide and geological conditions (i.e., thickness and depth) and hydrogeochemical properties (i.e., porosity, intrinsic permeability, salt concentration in groundwater, and volume fraction of chlorite) of a storage formation on the carbon dioxide plume extent, a series of sensitivity tests was also performed. The numerical simulation results show that the carbon dioxide plume extent is significantly affected by such injection scenarios, geological conditions, and hydrogeochemical properties. The carbon dioxide plume extent increases as the injection rate (with a constant injection period) increases, and this trend does not change with time. The carbon dioxide plume extent decreases as the injection period (with a constant total injection amount) increases until about 50 years, while it is not sensitive to the injection period after about 50 years. The carbon dioxide plume extent also decreases as the thickness increases until about 100 years, while it is not sensitive to the thickness after about 100 years. In contrast, the carbon dioxide plume extent decreases as the depth increases, and this trend is intensified with time. On the other hand, the

  11. Carbon dioxide hydrate and floods on Mars

    NASA Technical Reports Server (NTRS)

    Milton, D. J.

    1974-01-01

    Ground ice on Mars probably consists largely of carbon dioxide hydrate. This hydrate dissociates upon release of pressure at temperatures between 0 and 10 C. The heat capacity of the ground would be sufficient to produce up to 4% (by volume) of water at a rate equal to that at which it can be drained away. Catastrophic dissociation of carbon dioxide hydrate during some past epoch when the near-surface temperature was in this range would have produced chaotic terrain and flood channels.

  12. Transient Earth system responses to cumulative carbon dioxide emissions: linearities, uncertainties, and probabilities in an observation-constrained model ensemble

    NASA Astrophysics Data System (ADS)

    Steinacher, M.; Joos, F.

    2016-02-01

    Information on the relationship between cumulative fossil CO2 emissions and multiple climate targets is essential to design emission mitigation and climate adaptation strategies. In this study, the transient response of a climate or environmental variable per trillion tonnes of CO2 emissions, termed TRE, is quantified for a set of impact-relevant climate variables and from a large set of multi-forcing scenarios extended to year 2300 towards stabilization. An ˜ 1000-member ensemble of the Bern3D-LPJ carbon-climate model is applied and model outcomes are constrained by 26 physical and biogeochemical observational data sets in a Bayesian, Monte Carlo-type framework. Uncertainties in TRE estimates include both scenario uncertainty and model response uncertainty. Cumulative fossil emissions of 1000 Gt C result in a global mean surface air temperature change of 1.9 °C (68 % confidence interval (c.i.): 1.3 to 2.7 °C), a decrease in surface ocean pH of 0.19 (0.18 to 0.22), and a steric sea level rise of 20 cm (13 to 27 cm until 2300). Linearity between cumulative emissions and transient response is high for pH and reasonably high for surface air and sea surface temperatures, but less pronounced for changes in Atlantic meridional overturning, Southern Ocean and tropical surface water saturation with respect to biogenic structures of calcium carbonate, and carbon stocks in soils. The constrained model ensemble is also applied to determine the response to a pulse-like emission and in idealized CO2-only simulations. The transient climate response is constrained, primarily by long-term ocean heat observations, to 1.7 °C (68 % c.i.: 1.3 to 2.2 °C) and the equilibrium climate sensitivity to 2.9 °C (2.0 to 4.2 °C). This is consistent with results by CMIP5 models but inconsistent with recent studies that relied on short-term air temperature data affected by natural climate variability.

  13. Global deforestation: contribution to atmospheric carbon dioxide

    SciTech Connect

    Woodwell, G.M.; Hobbie, J.E.; Houghton, R.A.; Melillo, J.M.; Moore, B.; Peterson, B.J.; Shaver, G.R.

    1983-12-09

    A study of effects of terrestrial biota on the amount of carbon dioxide in the atmosphere suggests that the global net release of carbon due to forest clearing between 1960 and 1980 was between 135 X 10/sup 15/ and 228 X 10/sup 15/ grams. Between 1.8 X 10/sup 15/ and 4.7 X 10/sup 15/ grams of carbon were released in 1980, of which nearly 80 percent was due to deforestation, principally in the tropics. The annual release of carbon from the biota and soils exceeded the release from fossil fuels until about 1960. Because the biotic release has been and remains much larger than is commonly assumed, the airborne fraction, usually considered to be about 50 percent of the releases from fossil fuels, was probably between 22 and 43 percent of the total carbon released in 1980. The increase in carbon dioxide in the atmosphere is thought by some to be increasing the storage of carbon in the earth's remaining forests sufficiently to offset the release from deforestation. The interpretation of the evidence presented here suggests no such effect; deforestation appears to be the dominant biotic effect on atmospheric carbon dioxide. If deforestation increases in proportion to population, the biotic release of carbon will reach 9 X 10/sup 15/ grams per year before forests are exhausted early in the next century. The possibilities for limiting the accumulation of carbon dioxide in the atmosphere through reduction in use of fossil fuels and through management of forests may be greater than is commonly assumed.

  14. International Space Station Carbon Dioxide Removal Assembly Testing

    NASA Technical Reports Server (NTRS)

    Knox, James C.

    2000-01-01

    Performance testing of the International Space Station Carbon Dioxide Removal Assembly flight hardware in the United States Laboratory during 1999 is described. The CDRA exceeded carbon dioxide performance specifications and operated flawlessly. Data from this test is presented.

  15. Organic syntheses employing supercritical carbon dioxide as a reaction solvent

    NASA Technical Reports Server (NTRS)

    Barstow, Leon E. (Inventor); Ward, Glen D. (Inventor); Bier, Milan (Inventor)

    1991-01-01

    Chemical reactions are readily carried out using supercritical carbon dioxide as the reaction medium. Supercritical carbon dioxide is of special value as a reaction medium in reactions for synthesizing polypeptides, for sequencing polypeptides, or for amino acid analysis.

  16. Organic syntheses employing supercritical carbon dioxide as a reaction solvent

    NASA Technical Reports Server (NTRS)

    Barstow, Leon E. (Inventor); Ward, Glen D. (Inventor); Bier, Milan (Inventor)

    1993-01-01

    Chemical reactions are readily carried out using supercritical carbon dioxide as the reaction medium. Supercritical carbon dioxide is of special value as a reaction medium in reactions for synthesizing polypeptides, for sequencing polypeptides, or for amino acid analysis.

  17. Gas diffusion cell removes carbon dioxide from occupied airtight enclosures

    NASA Technical Reports Server (NTRS)

    1964-01-01

    Small, lightweight permeable cell package separates and removes carbon dioxide from respiratory gas mixtures. The cell is regenerative while chemically inert in the presence of carbon dioxide so that only adsorption takes place.

  18. Equilibrium responses of global net primary production and carbon storage to doubled atmospheric carbon dioxide: Sensitivity to changes in vegetation nitrogen concentration

    USGS Publications Warehouse

    McGuire, David A.; Melillo, J.M.; Kicklighter, D.W.; Pan, Y.; Xiao, X.; Helfrich, J.; Moore, B.; Vorosmarty, C.J.; Schloss, A.L.

    1997-01-01

    We ran the terrestrial ecosystem model (TEM) for the globe at 0.5?? resolution for atmospheric CO2 concentrations of 340 and 680 parts per million by volume (ppmv) to evaluate global and regional responses of net primary production (NPP) and carbon storage to elevated CO2 for their sensitivity to changes in vegetation nitrogen concentration. At 340 ppmv, TEM estimated global NPP of 49.0 1015 g (Pg) C yr-1 and global total carbon storage of 1701.8 Pg C; the estimate of total carbon storage does not include the carbon content of inert soil organic matter. For the reference simulation in which doubled atmospheric CO2 was accompanied with no change in vegetation nitrogen concentration, global NPP increased 4.1 Pg C yr-1 (8.3%), and global total carbon storage increased 114.2 Pg C. To examine sensitivity in the global responses of NPP and carbon storage to decreases in the nitrogen concentration of vegetation, we compared doubled CO2 responses of the reference TEM to simulations in which the vegetation nitrogen concentration was reduced without influencing decomposition dynamics ("lower N" simulations) and to simulations in which reductions in vegetation nitrogen concentration influence decomposition dynamics ("lower N+D" simulations). We conducted three lower N simulations and three lower N+D simulations in which we reduced the nitrogen concentration of vegetation by 7,5, 15.0, and 22.5%. In the lower N simulations, the response of global NPP to doubled atmospheric CO2 increased approximately 2 Pg C yr-1 for each incremental 7.5% reduction in vegetation nitrogen concentration, and vegetation carbon increased approximately an additional 40 Pg C, and soil carbon increased an additional 30 Pg C, for a total carbon storage increase of approximately 70 Pg C. In the lower N+D simulations, the responses of NPP and vegetation carbon storage were relatively insensitive to differences in the reduction of nitrogen concentration, but soil carbon storage showed a large change. The

  19. Tuning Organic Carbon Dioxide Absorbents for Carbonation and Decarbonation

    PubMed Central

    Rajamanickam, Ramachandran; Kim, Hyungsoo; Park, Ji-Woong

    2015-01-01

    The reaction of carbon dioxide with a mixture of a superbase and alcohol affords a superbase alkylcarbonate salt via a process that can be reversed at elevated temperatures. To utilize the unique chemistry of superbases for carbon capture technology, it is essential to facilitate carbonation and decarbonation at desired temperatures in an easily controllable manner. Here, we demonstrate that the thermal stabilities of the alkylcarbonate salts of superbases in organic solutions can be tuned by adjusting the compositions of hydroxylic solvent and polar aprotic solvent mixtures, thereby enabling the best possible performances to be obtained from the various carbon dioxide capture agents based on these materials. The findings provides valuable insights into the design and optimization of organic carbon dioxide absorbents. PMID:26033537

  20. Discussion of Refrigeration Cycle Using Carbon Dioxide as Refrigerant

    NASA Astrophysics Data System (ADS)

    Ji, Amin; Sun, Miming; Li, Jie; Yin, Gang; Cheng, Keyong; Zhen, Bing; Sun, Ying

    Nowadays, the problem of the environment goes worse, it urges people to research and study new energy-saving and environment-friendly refrigerants, such as carbon dioxide, at present, people do research on carbon dioxide at home and abroad. This paper introduces the property of carbon dioxide as a refrigerant, sums up and analyses carbon dioxide refrigeration cycles, and points out the development and research direction in the future.

  1. Acid sorption regeneration process using carbon dioxide

    DOEpatents

    King, C. Judson; Husson, Scott M.

    2001-01-01

    Carboxylic acids are sorbed from aqueous feedstocks onto a solid adsorbent in the presence of carbon dioxide under pressure. The acids are freed from the sorbent phase by a suitable regeneration method, one of which is treating them with an organic alkylamine solution thus forming an alkylamine-carboxylic acid complex which thermally decomposes to the desired carboxylic acid and the alkylamine.

  2. Catalyst cartridge for carbon dioxide reduction unit

    NASA Technical Reports Server (NTRS)

    Holmes, R. F. (Inventor)

    1973-01-01

    A catalyst cartridge, for use in a carbon dioxide reducing apparatus in a life support system for space vehicles, is described. The catalyst cartridge includes an inner perforated metal wall, an outer perforated wall space outwardly from the inner wall, a base plate closing one end of the cartridge, and a cover plate closing the other end of the cartridge. The cover plate has a central aperture through which a supply line with a heater feeds a gaseous reaction mixture comprising hydrogen and carbon dioxide at a temperature from about 1000 to about 1400 F. The outer surfaces of the internal wall and the inner surfaces of the outer wall are lined with a ceramic fiber batting material of sufficient thickness to prevent carbon formed in the reaction from passing through it. The portion of the surfaces of the base and cover plates defined within the inner and outer walls are also lined with ceramic batting. The heated reaction mixture passes outwardly through the inner perforated wall and ceramic batting and over the catalyst. The solid carbon product formes is retained within the enclosure containing the catalyst. The solid carbon product formed is retained within the enclosure containing the catalyst. The water vapor and unreacted carbon dioxide and any intermediate products pass through the perforations of the outer wall.

  3. 46 CFR 169.565 - Fixed carbon dioxide system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565... Lifesaving and Firefighting Equipment Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space protected must be equal to the gross volume...

  4. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Carbon dioxide record. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted...

  5. 46 CFR 169.565 - Fixed carbon dioxide system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565... Lifesaving and Firefighting Equipment Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space protected must be equal to the gross volume...

  6. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Carbon dioxide record. 24..., DEPARTMENT OF THE TREASURY ALCOHOL WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted...

  7. 46 CFR 169.565 - Fixed carbon dioxide system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565... Lifesaving and Firefighting Equipment Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space protected must be equal to the gross volume...

  8. 40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 19 2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration... Exhaust Test Procedures § 86.1324-84 Carbon dioxide analyzer calibration. Prior to its introduction into service and monthly thereafter, the NDIR carbon dioxide analyzer shall be calibrated as follows:...

  9. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... carbon dioxide. 26.52 Section 26.52 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From Puerto Rico § 26.52 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine;...

  10. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... carbon dioxide. 26.52 Section 26.52 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From Puerto Rico § 26.52 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine;...

  11. 40 CFR 90.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration... Emission Test Equipment Provisions § 90.320 Carbon dioxide analyzer calibration. (a) Prior to its initial... carbon dioxide analyzer as follows: (1) Follow good engineering practices for instrument start-up...

  12. 27 CFR 26.222 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... carbon dioxide. 26.222 Section 26.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From the Virgin Islands § 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

  13. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... carbon dioxide. 26.52 Section 26.52 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From Puerto Rico § 26.52 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine;...

  14. 21 CFR 868.5310 - Carbon dioxide absorber.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in...

  15. 27 CFR 26.222 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... carbon dioxide. 26.222 Section 26.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From the Virgin Islands § 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

  16. 40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Exhaust Test Procedures § 86.1324-84 Carbon dioxide analyzer calibration. Prior to its introduction into service and monthly thereafter, the NDIR carbon dioxide analyzer shall be calibrated as follows:...

  17. 40 CFR 90.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration... Emission Test Equipment Provisions § 90.320 Carbon dioxide analyzer calibration. (a) Prior to its initial... carbon dioxide analyzer as follows: (1) Follow good engineering practices for instrument start-up...

  18. 40 CFR 90.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration... Emission Test Equipment Provisions § 90.320 Carbon dioxide analyzer calibration. (a) Prior to its initial... carbon dioxide analyzer as follows: (1) Follow good engineering practices for instrument start-up...

  19. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Carbon dioxide record. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted...

  20. 21 CFR 868.5300 - Carbon dioxide absorbent.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for medical purposes that consists of...

  1. 27 CFR 26.222 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... carbon dioxide. 26.222 Section 26.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From the Virgin Islands § 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

  2. 46 CFR 108.431 - Carbon dioxide systems: General.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431... AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a) Sections 108.431 through 108.457 apply to high pressure...

  3. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... carbon dioxide. 26.52 Section 26.52 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From Puerto Rico § 26.52 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine;...

  4. 21 CFR 868.5300 - Carbon dioxide absorbent.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for medical purposes that consists of...

  5. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Test Equipment Provisions § 89.322 Carbon dioxide analyzer calibration. (a) Prior to its introduction... carbon dioxide analyzer shall be calibrated on all normally used instrument ranges. New...

  6. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration... Test Equipment Provisions § 89.322 Carbon dioxide analyzer calibration. (a) Prior to its introduction... carbon dioxide analyzer shall be calibrated on all normally used instrument ranges. New...

  7. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Carbon dioxide record. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted...

  8. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration... Test Equipment Provisions § 89.322 Carbon dioxide analyzer calibration. (a) Prior to its introduction... carbon dioxide analyzer shall be calibrated on all normally used instrument ranges. New...

  9. 46 CFR 108.431 - Carbon dioxide systems: General.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431... AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a) Sections 108.431 through 108.457 apply to high pressure...

  10. 21 CFR 868.5310 - Carbon dioxide absorber.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in...

  11. 21 CFR 868.5310 - Carbon dioxide absorber.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in...

  12. 40 CFR 90.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Emission Test Equipment Provisions § 90.320 Carbon dioxide analyzer calibration. (a) Prior to its initial... carbon dioxide analyzer as follows: (1) Follow good engineering practices for instrument start-up...

  13. 21 CFR 868.5310 - Carbon dioxide absorber.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in...

  14. 21 CFR 868.5300 - Carbon dioxide absorbent.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for medical purposes that consists of...

  15. 21 CFR 868.5300 - Carbon dioxide absorbent.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for medical purposes that consists of...

  16. 27 CFR 26.222 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... carbon dioxide. 26.222 Section 26.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From the Virgin Islands § 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

  17. 9 CFR 313.5 - Chemical; carbon dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Chemical; carbon dioxide. 313.5... INSPECTION AND CERTIFICATION HUMANE SLAUGHTER OF LIVESTOCK § 313.5 Chemical; carbon dioxide. The slaughtering of sheep, calves and swine with the use of carbon dioxide gas and the handling in...

  18. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Carbon dioxide record. 24..., DEPARTMENT OF THE TREASURY ALCOHOL WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted...

  19. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration... Test Equipment Provisions § 89.322 Carbon dioxide analyzer calibration. (a) Prior to its introduction... carbon dioxide analyzer shall be calibrated on all normally used instrument ranges. New...

  20. 21 CFR 868.5300 - Carbon dioxide absorbent.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for medical purposes that consists of...

  1. 21 CFR 868.5310 - Carbon dioxide absorber.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in...

  2. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... carbon dioxide. 26.52 Section 26.52 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From Puerto Rico § 26.52 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine;...

  3. 46 CFR 108.431 - Carbon dioxide systems: General.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431... AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a) Sections 108.431 through 108.457 apply to high pressure...

  4. 9 CFR 313.5 - Chemical; carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Chemical; carbon dioxide. 313.5... INSPECTION AND CERTIFICATION HUMANE SLAUGHTER OF LIVESTOCK § 313.5 Chemical; carbon dioxide. The slaughtering of sheep, calves and swine with the use of carbon dioxide gas and the handling in...

  5. 46 CFR 108.431 - Carbon dioxide systems: General.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431... AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a) Sections 108.431 through 108.457 apply to high pressure...

  6. 46 CFR 108.431 - Carbon dioxide systems: General.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431... AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a) Sections 108.431 through 108.457 apply to high pressure...

  7. 9 CFR 313.5 - Chemical; carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Chemical; carbon dioxide. 313.5... INSPECTION AND CERTIFICATION HUMANE SLAUGHTER OF LIVESTOCK § 313.5 Chemical; carbon dioxide. The slaughtering of sheep, calves and swine with the use of carbon dioxide gas and the handling in...

  8. 27 CFR 26.222 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... carbon dioxide. 26.222 Section 26.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From the Virgin Islands § 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

  9. Ocean uptake of carbon dioxide

    SciTech Connect

    Peng, Tsung-Hung; Takahashi, Taro

    1993-06-01

    Factors controlling the capacity of the ocean for taking up anthropogenic C0{sup 2} include carbon chemistry, distribution of alkalinity, pCO{sup 2} and total concentration of dissolved C0{sup 2}, sea-air pCO{sup 2} difference, gas exchange rate across the sea-air interface, biological carbon pump, ocean water circulation and mixing, and dissolution of carbonate in deep sea sediments. A general review of these processes is given and models of ocean-atmosphere system based on our understanding of these regulating processes axe used to estimate the magnitude of C0{sup 2} uptake by the ocean. We conclude that the ocean can absorb up to 35% of the fossil fuel emission. Direct measurements show that 55% Of C0{sup 2} from fossil fuel burning remains in the atmosphere. The remaining 10% is not accounted for by atmospheric increases and ocean uptake. In addition, it is estimated that an amount equivalent to 30% of recent annual fossil fuel emissions is released into the atmosphere as a result of deforestation and farming. To balance global carbon budget, a sizable carbon sink besides the ocean is needed. Storage of carbon in terrestrial biosphere as a result of C0{sup 2} fertilization is a potential candidate for such missing carbon sinks.

  10. Ocean uptake of carbon dioxide

    SciTech Connect

    Peng, Tsung-Hung ); Takahashi, Taro . Lamont-Doherty Earth Observatory)

    1993-01-01

    Factors controlling the capacity of the ocean for taking up anthropogenic C0[sup 2] include carbon chemistry, distribution of alkalinity, pCO[sup 2] and total concentration of dissolved C0[sup 2], sea-air pCO[sup 2] difference, gas exchange rate across the sea-air interface, biological carbon pump, ocean water circulation and mixing, and dissolution of carbonate in deep sea sediments. A general review of these processes is given and models of ocean-atmosphere system based on our understanding of these regulating processes axe used to estimate the magnitude of C0[sup 2] uptake by the ocean. We conclude that the ocean can absorb up to 35% of the fossil fuel emission. Direct measurements show that 55% Of C0[sup 2] from fossil fuel burning remains in the atmosphere. The remaining 10% is not accounted for by atmospheric increases and ocean uptake. In addition, it is estimated that an amount equivalent to 30% of recent annual fossil fuel emissions is released into the atmosphere as a result of deforestation and farming. To balance global carbon budget, a sizable carbon sink besides the ocean is needed. Storage of carbon in terrestrial biosphere as a result of C0[sup 2] fertilization is a potential candidate for such missing carbon sinks.

  11. Effects of carbon dioxide on laryngeal receptors

    SciTech Connect

    Anderson, J.W.; Sant'Ambrogio, F.B.; Orani, G.P.; Sant'Ambrogio, G.; Mathew, O.P. )

    1990-02-26

    Carbon dioxide (CO{sub 2}) either stimulates or inhibits laryngeal receptors in the cat. The aim of this study was to correlate the CO{sub 2} response of laryngeal receptors with their response to other known stimuli (i.e. pressure, movement, cold, water and smoke). Single unit action potentials were recorded from fibers in the superior laryngeal nerve of 5 anesthetized, spontaneously breathing dogs together with CO{sub 2} concentration, esophageal and subglottic pressure. Constant streams of warm, humidified air or 10% CO{sub 2} in O{sub 2} were passed through the functionally isolated upper airway for 60 s. Eight of 13 randomly firing or silent receptors were stimulated by CO{sub 2} (from 0.4{plus minus}0.1 to 1.8{plus minus}0.4 imp.s). These non-respiratory-modulated receptors were more strongly stimulated by solutions lacking Cl{sup {minus}} and/or cigarette smoke. Six of 21 respiratory modulated receptors (responding to pressure and/or laryngeal motion) were either inhibited or stimulated by CO{sub 2}. Our results show that no laryngeal receptor responds only to CO{sub 2}. Silent or randomly active receptors were stimulated most often by CO{sub 2} consistent with the reflex effect of CO{sub 2} in the larynx.

  12. Drosophila Tracks Carbon Dioxide in Flight

    PubMed Central

    Wasserman, Sara; Salomon, Alexandra; Frye, Mark A.

    2013-01-01

    Summary Carbon dioxide (CO2) elicits an attractive host-seeking response from mosquitos [1–3] yet is innately aversive to Drosophila melanogaster [4, 5] despite being a plentiful byproduct of attractive fermenting food sources. Prior studies used walking flies exclusively, yet adults track distant food sources on the wing [6]. Here we show that a fly tethered within a magnetic field allowing free rotation about the yaw axis [7] actively seeks a narrow CO2 plume during flight. Genetic disruption of the canonical CO2-sensing olfactory neurons does not alter in-flight attraction to CO2; however, antennal ablation and genetic disruption of the Ir64a acid sensor do. Surprisingly, mutation of the obligate olfactory coreceptor (Orco [8]) does not abolish CO2 aversion during walking [4] yet eliminates CO2 tracking in flight. The biogenic amine octopamine regulates critical physiological processes during flight [9–11], and blocking synaptic output from octopamine neurons inverts the valence assigned to CO2 and elicits an aversive response in flight. Combined, our results suggest that a novel Orco-mediated olfactory pathway that gains sensitivity to CO2 in flight via changes in octopamine levels, along with Ir64a, quickly switches the valence of a key environmental stimulus in a behavioral-state-dependent manner. PMID:23352695

  13. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Carbon monoxide and carbon dioxide... Test Procedures § 86.316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made with nondispersive infrared (NDIR) an analyzers....

  14. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Carbon monoxide and carbon dioxide... Test Procedures § 86.316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made with nondispersive infrared (NDIR) an analyzers....

  15. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Carbon monoxide and carbon dioxide... Test Procedures § 86.316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made with nondispersive infrared (NDIR) an analyzers....

  16. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Carbon monoxide and carbon dioxide... Test Procedures § 86.316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made with nondispersive infrared (NDIR) an analyzers....

  17. Which plant trait explains the variations in relative growth rate and its response to elevated carbon dioxide concentration among Arabidopsis thaliana ecotypes derived from a variety of habitats?

    PubMed

    Oguchi, Riichi; Ozaki, Hiroshi; Hanada, Kousuke; Hikosaka, Kouki

    2016-03-01

    Elevated atmospheric carbon dioxide (CO2) concentration ([CO2]) enhances plant growth, but this enhancement varies considerably. It is still uncertain which plant traits are quantitatively related to the variation in plant growth. To identify the traits responsible, we developed a growth analysis model that included primary parameters associated with morphology, nitrogen (N) use, and leaf and root activities. We analysed the vegetative growth of 44 ecotypes of Arabidopsis thaliana L. grown at ambient and elevated [CO2] (800 μmol mol(-1)). The 44 ecotypes were selected such that they were derived from various altitudes and latitudes. Relative growth rate (RGR; growth rate per unit plant mass) and its response to [CO2] varied by 1.5- and 1.7-fold among ecotypes, respectively. The variation in RGR at both [CO2]s was mainly explained by the variation in leaf N productivity (LNP; growth rate per leaf N),which was strongly related to photosynthetic N use efficiency (PNUE). The variation in the response of RGR to [CO2] was also explained by the variation in the response of LNP to [CO2]. Genomic analyses indicated that there was no phylogenetic constraint on inter-ecotype variation in the CO2 response of RGR or LNP. We conclude that the significant variation in plant growth and its response to [CO2] among ecotypes reflects the variation in N use for photosynthesis among ecotypes, and that the response of PNUE to CO2 is an important target for predicting and/or breeding plants that have high growth rates at elevated [CO2].

  18. Responses of calcification of massive and encrusting corals to past, present, and near-future ocean carbon dioxide concentrations.

    PubMed

    Iguchi, Akira; Kumagai, Naoki H; Nakamura, Takashi; Suzuki, Atsushi; Sakai, Kazuhiko; Nojiri, Yukihiro

    2014-12-15

    In this study, we report the acidification impact mimicking the pre-industrial, the present, and near-future oceans on calcification of two coral species (Porites australiensis, Isopora palifera) by using precise pCO2 control system which can produce acidified seawater under stable pCO2 values with low variations. In the analyses, we performed Bayesian modeling approaches incorporating the variations of pCO2 and compared the results between our modeling approach and classical statistical one. The results showed highest calcification rates in pre-industrial pCO2 level and gradual decreases of calcification in the near-future ocean acidification level, which suggests that ongoing and near-future ocean acidification would negatively impact coral calcification. In addition, it was expected that the variations of parameters of carbon chemistry may affect the inference of the best model on calcification responses to these parameters between Bayesian modeling approach and classical statistical one even under stable pCO2 values with low variations.

  19. Miniaturized Amperometric Solid Electrolyte Carbon Dioxide Sensors

    NASA Technical Reports Server (NTRS)

    Hunter, G. W.; Xu, J. C.; Liu, C. C.; Hammond, J. W.; Ward, B.; Lukco, D.; Lampard, P.; Artale, M.; Androjna, D.

    2006-01-01

    A miniaturized electrochemical carbon dioxide (CO2) sensor using Na3Z r2Si2PO12 (NASICON) as a solid electrolyte has been fabricated and de monstrated. Microfabrication techniques were used for sensor fabricat ion to yield a sensing area around 1.0 mm x 1.1 mm. The NASICON solid electrolyte and the Na2CO3/BaCO3 (1:1.7 molar ratio) auxiliary elect rolyte were deposited by sputtering in between and on top of the inte rdigitated finger-shaped platinum electrodes. This structure maximize s the length of the three-phase boundary (electrode, solid electrolyt e, and auxiliary electrolyte), which is critical for gas sensing. The robust CO2 sensor operated up to 600 C in an amperometric mode and a ttempts were made to optimize sensor operating parameters. Concentrat ions of CO2 between 0.02% and 4% were detected and the overall sensor performance was evaluated. Linear response of sensor current output to ln[CO2 concentration] ranging from 0.02% to 1% was achieved.

  20. Carbon dioxide capture and use: organic synthesis using carbon dioxide from exhaust gas.

    PubMed

    Kim, Seung Hyo; Kim, Kwang Hee; Hong, Soon Hyeok

    2014-01-13

    A carbon capture and use (CCU) strategy was applied to organic synthesis. Carbon dioxide (CO2) captured directly from exhaust gas was used for organic transformations as efficiently as hyper-pure CO2 gas from a commercial source, even for highly air- and moisture-sensitive reactions. The CO2 capturing aqueous ethanolamine solution could be recycled continuously without any diminished reaction efficiency.

  1. Recycling technology of emitted carbon dioxide

    SciTech Connect

    Arakawa, Hironori

    1993-12-31

    Ways to halt global warming are being discussed worldwide. Global warming is an energy problem which is mainly attributed to the large volumes of carbon dioxide (CO{sub 2}) released into the atmosphere from the rapid increase in energy consumption since the Industrial Revolution. The basic solution to the problem, therefore, is to cut consumption of fossil fuels. To this end, it is important to promote energy conservation by improving the fuel efficiency of machines, as well as shift to energy sources that do not emit carbon dioxide and develop related technologies. If current trends in economic growth continue in the devloping world as well as the developed countries, there can be no doubt that energy consumption will increase. Therefore, alongside energy conservation and the development of alternative energies, the importance of technologies to recover and fix CO{sub 2} will increase in the fight against global warming.

  2. Sequestering ADM ethanol plant carbon dioxide

    USGS Publications Warehouse

    Finley, R.J.; Riddle, D.

    2008-01-01

    Archer Daniels Midland Co. (ADM) and the Illinois State Geological Survey (ISGS) are collaborating on a project in confirming that a rock formation can store carbon dioxide from the plant in its pores. The project aimed to sequester the gas underground permanently to minimize release of the greenhouse gas into the atmosphere. It is also designed to store one million tons of carbon dioxide over a three-year period. The project is worth $84.3M, funded by $66.7M from the US Department Energy, supplemented by co-funding from ADM and other corporate and state resources. The project will start drilling of wells to an expected depth over 6500 feet into the Mount Simon Sandstone formation.

  3. Climate impact of increasing atmospheric carbon dioxide.

    PubMed

    Hansen, J; Johnson, D; Lacis, A; Lebedeff, S; Lee, P; Rind, D; Russell, G

    1981-08-28

    The global temperature rose by 0.2 degrees C between the middle 1960's and 1980, yielding a warming of 0.4 degrees C in the past century. This temperature increase is consistent with the calculated greenhouse effect due to measured increases of atmospheric carbon dioxide. Variations of volcanic aerosols and possibly solar luminosity appear to be primary causes of observed fluctuations about the mean trend of increasing temperature. It is shown that the anthropogenic carbon dioxide warming should emerge from the noise level of natural climate variability by the end of the century, and there is a high probability of warming in the 1980's. Potential effects on climate in the 21st century include the creation of drought-prone regions in North America and central Asia as part of a shifting of climatic zones, erosion of the West Antarctic ice sheet with a consequent worldwide rise in sea level, and opening of the fabled Northwest Passage. PMID:17789014

  4. Climate impact of increasing atmospheric carbon dioxide.

    PubMed

    Hansen, J; Johnson, D; Lacis, A; Lebedeff, S; Lee, P; Rind, D; Russell, G

    1981-08-28

    The global temperature rose by 0.2 degrees C between the middle 1960's and 1980, yielding a warming of 0.4 degrees C in the past century. This temperature increase is consistent with the calculated greenhouse effect due to measured increases of atmospheric carbon dioxide. Variations of volcanic aerosols and possibly solar luminosity appear to be primary causes of observed fluctuations about the mean trend of increasing temperature. It is shown that the anthropogenic carbon dioxide warming should emerge from the noise level of natural climate variability by the end of the century, and there is a high probability of warming in the 1980's. Potential effects on climate in the 21st century include the creation of drought-prone regions in North America and central Asia as part of a shifting of climatic zones, erosion of the West Antarctic ice sheet with a consequent worldwide rise in sea level, and opening of the fabled Northwest Passage.

  5. Climate impact of increasing atmospheric carbon dioxide

    SciTech Connect

    Hansen, J.; Johnson, D.; Lacis, A.; Lebedeff, S.; Lee, P.; Rind, D.; Russell, G.

    1981-08-28

    The global temperature rose by 0.2/sup 0/C between the middle 1960's and 1980, yielding a warming of 0.4/sup 0/C in the past century. This temperature increase is consistent with the calculated greenhouse effect due to measured increases of atmospheric carbon dioxide. Variations of volcanic aerosols and possibly solar luminosity appear to be primary causes of observed fluctuations about the mean trend of increasing temperature. It is shown that the anthropogenic carbon dioxide warming should emerge from the noise level of natural climate variability by the end of the century, and there is a high probability of warming in the 1980's. Potential effects on climate in the 21st century include the creation of drought-prone regions in North America and central Asia as part of a shifting of climatic zones, erosion of the West Antarctic ice sheet with a consequent worldwide rise in sea level, and opening of the fabled Northwest Passage.

  6. Carbon dioxide sequestration by direct mineral carbonation with carbonic acid

    SciTech Connect

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

    2000-07-01

    The Albany Research Center (ARC) of the US Department of Energy (DOE) has been conducting a series of mineral carbonation tests at its Albany, Oregon, facility over the past 2 years as part of a Mineral Carbonation Study Program within the DOE. The ARC tests have focused on ex-situ mineral carbonation in an aqueous system. The process developed at ARC utilizes a slurry of water mixed with a magnesium silicate mineral, olivine [forsterite and member (mg{sub 2}SiO{sub 4})], or serpentine [Mg{sub 3}Si{sub 2}O{sub 5}(OH){sub 4}]. This slurry is reacted with supercritical carbon dioxide (CO{sub 2}) to produce magnesite (MgCO{sub 3}). The CO{sub 2} is dissolved in water to form carbonic acid (H{sub 2}CO{sub 3}), which dissociates to H{sup +} and HCO{sub 3}{sup {minus}}. The H{sup +} reacts with the mineral, liberating Mg{sup 2+} cations which react with the bicarbonate to form the solid carbonate. The process is designed to simulate the natural serpentinization reaction of ultramafic minerals, and for this reason, these results may also be applicable to in-situ geological sequestration regimes. Results of the baseline tests, conducted on ground products of the natural minerals, have been encouraging. Tests conducted at ambient temperature (22 C) and subcritical CO{sub 2} pressures (below 73 atm) resulted in very slow conversion to the carbonate. However, when elevated temperatures and pressures are utilized, coupled with continuous stirring of the slurry and gas dispersion within the water column, significant reaction occurs within much shorter reaction times. Extent of reaction, as measured by the stoichiometric conversion of the silicate mineral (olivine) to the carbonate, is roughly 90% within 24 hours, using distilled water, and a reaction temperature of 185 C and a partial pressure of CO{sub 2} (P{sub CO{sub 2}}) of 115 atm. Recent tests using a bicarbonate solution, under identical reaction conditions, have achieved roughly 83% conversion of heat treated serpentine

  7. Carbon dioxide sequestration by direct mineral carbonation with carbonic acid

    SciTech Connect

    O'Connor, William K.; Dahlin, David C.; Nilsen, David N.; Walters, Richard P.; Turner, Paul C.

    2000-01-01

    The Albany Research Center (ARC) of the U.S. Dept. of Energy (DOE) has been conducting a series of mineral carbonation tests at its Albany, Oregon, facility over the past 2 years as part of a Mineral Carbonation Study Program within the DOE. Other participants in this Program include the Los Alamos National Laboratory, Arizona State University, Science Applications International Corporation, and the DOE National Energy Technology Laboratory. The ARC tests have focused on ex-situ mineral carbonation in an aqueous system. The process developed at ARC utilizes a slurry of water mixed with a magnesium silicate mineral, olivine [forsterite end member (Mg2SiO4)], or serpentine [Mg3Si2O5(OH)4]. This slurry is reacted with supercritical carbon dioxide (CO2) to produce magnesite (MgCO3). The CO2 is dissolved in water to form carbonic acid (H2CO3), which dissociates to H+ and HCO3 -. The H+ reacts with the mineral, liberating Mg2+ cations which react with the bicarbonate to form the solid carbonate. The process is designed to simulate the natural serpentinization reaction of ultramafic minerals, and for this reason, these results may also be applicable to in-situ geological sequestration regimes. Results of the baseline tests, conducted on ground products of the natural minerals, have been encouraging. Tests conducted at ambient temperature (22 C) and subcritical CO2 pressures (below 73 atm) resulted in very slow conversion to the carbonate. However, when elevated temperatures and pressures are utilized, coupled with continuous stirring of the slurry and gas dispersion within the water column, significant reaction occurs within much shorter reaction times. Extent of reaction, as measured by the stoichiometric conversion of the silicate mineral (olivine) to the carbonate, is roughly 90% within 24 hours, using distilled water, and a reaction temperature of 185?C and a partial pressure of CO2 (PCO2) of 115 atm. Recent tests using a bicarbonate solution, under identical reaction

  8. Low soil temperature inhibits the effect of high nutrient supply on photosynthetic response to elevated carbon dioxide concentration in white birch seedlings.

    PubMed

    Ambebe, Titus F; Dang, Qing-Lai; Li, Junlin

    2010-02-01

    To investigate the interactive effects of soil temperature (T(soil)) and nutrient availability on the response of photosynthesis to elevated atmospheric carbon dioxide concentration ([CO(2)]), white birch (Betula papyrifera Marsh.) seedlings were exposed to ambient (360 micromol mol(-1)) or elevated (720 micromol mol(-1)) [CO(2)], three T(soil) (5, 15 and 25 degrees C initially, increased to 7, 17 and 27 degrees C, respectively, 1 month later) and three nutrient regimes (4/1.8/3.3, 80/35/66 and 160/70/132 mg l(-1) N/P/K) for 3 months in environment-controlled greenhouses. Elevated [CO(2)] increased net photosynthetic rate (A(n)), instantaneous water-use efficiency (IWUE), internal to ambient carbon dioxide concentration ratio (C(i)/C(a)), triose phosphate utilization (TPU) and photosynthetic linear electron transport to carboxylation (J(c)), and it decreased actual photochemical efficiency of photosystem II (DeltaF/F(m)'), the fraction of total linear electron transport partitioned to oxygenation (J(o)/J(T)) and leaf N concentration. The low T(soil) suppressed A(n), transpiration rate (E), TPU, DeltaF/F(m)' and J(c), but it increased J(o)/J(T). The low nutrient treatment reduced A(n), IWUE, maximum carboxylation rate of Rubisco, light-saturated electron transport rate, TPU, DeltaF/F(m)', J(c) and leaf N concentration, but increased C(i)/C(a). There were two-factor interactions for C(i)/C(a), TPU and leaf N concentration, and a significant effect of CO(2) x T(soil) x nutrient regime on A(n), IWUE and J(c). The stimulations of A(n) and IWUE by elevated [CO(2)] were limited to seedlings grown under the intermediate and high nutrient regimes at the intermediate and high T(soil). For J(c), the [CO(2)] effect was significant only at intermediate T(soil) + high nutrient availability. No significant [CO(2)] effects were observed under the low T(soil) at any nutrient level. Our results support this study's hypothesis that low T(soil) would reduce the positive effect of high

  9. Carbon Dioxide Effects Research and Assessment Program. Carbon Dioxide Research Progress Report, fiscal year 1979

    SciTech Connect

    Dahlman, R. C.; Gross, T.; Machta, L.; Elliott, W.; MacCracken, M.

    1980-04-01

    Research on the global carbon cycle and the effects of increased carbon dioxide on the global climate system is reported. Environmental and societal effects related to CO/sub 2/ and environmental control technology for CO/sub 2/ are also discussed. Lists of research projects and reports and publications of the Carbon Dioxide and Climate Research Program are included. An expanded CO/sub 2/ monitoring network is providing increased coverage for interpretation of patterns of sources and sinks seasonal variability, and documentation of the global growth of CO/sub 2/. Modeling studies emphasized that knowledge of the transport and mixing of surface ocean waters is important in understanding deep oceanic circulation. Initial studies in the equatorial Pacific are helping quantify estimates of the amount of outgassing CO/sub 2/ from tropical waters. During fiscal year 1979, there was a substantial increase in appreciation of the role of the ocean in controlling not only atmospheric CO/sub 2/ concentrations but also the climatic response to changes in concentration. Model simulations of the effect of doubled CO/sub 2/ concentration carried out with fixed ocean temperatures a situation that is possible during perhaps the next 20 years, showed relatively small summer heating over land areas. On the other hand, simulations in which the oceanic temperatures could come into instantaneous equilibrium with atmospheric conditions continued to show global temperature increases of 3 +- 1.5/sup 0/C, accentuated at high latitudes. To improve understanding of possible regional climate changes, there were increased efforts to reconstruct regional climatic patterns prevailing during past warm periods that might serve as analogs of future climatic conditions. Particular attention was directed to the climates of the United States and other countries bordering the North Atlantic Ocean during the warm period 5000 to 7000 years ago.

  10. Carbon Dioxide Laser Fiber Optics In Endoscopy

    NASA Astrophysics Data System (ADS)

    Fuller, Terry A.

    1982-12-01

    Carbon dioxide laser surgery has been limited to a great extent to surgical application on the integument and accessible cavities such as the cervix, vagina, oral cavities, etc. This limitation has been due to the rigid delivery systems available to all carbon dioxide lasers. Articulating arms (series of hollow tubes connected by articulating mirrors) have provided an effective means of delivery of laser energy to the patient as long as the lesion was within the direct line of sight. Even direct line-of-sight applications were restricted to physical dimension of the articulating arm or associated hand probes, manipulators and hollow tubes. The many attempts at providing straight endoscopic systems to the laser only stressed the need for a fiber optic capable of carrying the carbon dioxide laser wavelength. Rectangular and circular hollow metal waveguides, hollow dielectric waveguides have proven ineffective to the stringent requirements of a flexible surgical delivery system. One large diameter (1 cm) fiber optic delivery system, incorporates a toxic thalliumAbased fiber optic material. The device is an effective alternative to an articulating arm for external or conventional laser surgery, but is too large and stiff to use as a flexible endoscopic tool. The author describes the first highly flexible inexpensive series of fiber optic systems suitable for either conventional or endoscopic carbon dioxide laser surgery. One system (IRFLEX 3) has been manufactured by Medlase, Inc. for surgical uses capable of delivering 2000w, 100 mJ pulsed energy and 15w continuous wave. The system diameter is 0.035 inches in diameter. Surgically suitable fibers as small as 120 um have been manufactured. Other fibers (IRFLEX 142,447) have a variety of transmission characteristics, bend radii, etc.

  11. Electrochemical carbon dioxide concentrator: Math model

    NASA Technical Reports Server (NTRS)

    Marshall, R. D.; Schubert, F. H.; Carlson, J. N.

    1973-01-01

    A steady state computer simulation model of an Electrochemical Depolarized Carbon Dioxide Concentrator (EDC) has been developed. The mathematical model combines EDC heat and mass balance equations with empirical correlations derived from experimental data to describe EDC performance as a function of the operating parameters involved. The model is capable of accurately predicting performance over EDC operating ranges. Model simulation results agree with the experimental data obtained over the prediction range.

  12. There is more to climate than carbon dioxide.

    PubMed

    Walker, J C

    1995-07-01

    Discussion of climate change on a range of time scales has tended to focus on carbon dioxide and a changing greenhouse effect. Because carbon dioxide couples climate to ocean, land, and biota, it has appealed to scientists with an interest in the whole Earth system. Carbon dioxide has left a geological record in fossils, isotopes, and sediments, so we can reasonably expect to reconstruct its history. While important questions of detail remain to be resolved, many published applications of carbon cycle modelling suggest that we understand the biogeochemical cycles of carbon well enough to estimate carbon dioxide concentrations in the past and the future. Furthermore, we have an excellent instrumental record of recent changes in atmospheric carbon dioxide. While these considerations make carbon dioxide attractive to paleoclimatologists, they do not necessarily make it a major component of climate change. I shall argue in this paper that clouds deserve much more attention than they have been getting.

  13. 75 FR 29534 - Inorganic Nitrates-Nitrite, Carbon and Carbon Dioxide, and Sulfur Registration Review; Draft...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-26

    ... AGENCY Inorganic Nitrates-Nitrite, Carbon and Carbon Dioxide, and Sulfur Registration Review; Draft... and carbon dioxide, and gas cartridge uses of sulfur, and opens a public comment period on this... occur for all inorganic nitrates- nitrites, carbon and carbon dioxide uses, as well as gas...

  14. Carbon dioxide embolism during laparoscopic sleeve gastrectomy

    PubMed Central

    Zikry, Amir Abu; DeSousa, Kalindi; Alanezi, Khaled H

    2011-01-01

    Bariatric restrictive and malabsorptive operations are being carried out in most countries laparoscopically. Carbon dioxide or gas embolism has never been reported in obese patients undergoing bariatric surgery. We report a case of carbon dioxide embolism during laparoscopic sleeve gastrectomy (LSG) in a young super obese female patient. Early diagnosis and successful management of this complication are discussed. An 18-year-old super obese female patient with enlarged fatty liver underwent LSG under general anesthesia. During initial intra-peritoneal insufflation with CO2 at high flows through upper left quadrant of the abdomen, she had precipitous fall of end-tidal CO2 and SaO2 % accompanied with tachycardia. Early suspicion led to stoppage of further insufflation. Clinical parameters were stabilized after almost 30 min, while the blood gas analysis was restored to normal levels after 1 h. The area of gas entrainment on the damaged liver was recognized by the surgeon and sealed and the surgery was successfully carried out uneventfully. Like any other laparoscopic surgery, carbon dioxide embolism can occur during bariatric laparoscopic surgery also. Caution should be exercised when Veress needle is inserted through upper left quadrant of the abdomen in patients with enlarged liver. A high degree of suspicion and prompt collaboration between the surgeon and anesthetist can lead to complete recovery from this potentially fatal complication. PMID:21772696

  15. Carbon dioxide in Arctic and subarctic regions

    SciTech Connect

    Gosink, T. A.; Kelley, J. J.

    1981-03-01

    A three year research project was presented that would define the role of the Arctic ocean, sea ice, tundra, taiga, high latitude ponds and lakes and polar anthropogenic activity on the carbon dioxide content of the atmosphere. Due to the large physical and geographical differences between the two polar regions, a comparison of CO/sub 2/ source and sink strengths of the two areas was proposed. Research opportunities during the first year, particularly those aboard the Swedish icebreaker, YMER, provided additional confirmatory data about the natural source and sink strengths for carbon dioxide in the Arctic regions. As a result, the hypothesis that these natural sources and sinks are strong enough to significantly affect global atmospheric carbon dioxide levels is considerably strengthened. Based on the available data we calculate that the whole Arctic region is a net annual sink for about 1.1 x 10/sup 15/ g of CO/sub 2/, or the equivalent of about 5% of the annual anthropogenic input into the atmosphere. For the second year of this research effort, research on the seasonal sources and sinks of CO/sub 2/ in the Arctic will be continued. Particular attention will be paid to the seasonal sea ice zones during the freeze and thaw periods, and the tundra-taiga regions, also during the freeze and thaw periods.

  16. Carbon dioxide makes heat therapy work

    SciTech Connect

    Sherman, H.

    1987-01-01

    Scientists can now propagate healthy blueberry and raspberry plants from virus-infected stock by treating it with heat and carbon dioxide. Plants are grown at 100/sup 0/F, which makes them develop faster than the virus can spread. Then cuttings are taken of the new growth - less than an inch long - and grown into full-sized, virus-free plants. But in this race to outdistance the virus, some plant species are not able to take the heat. Some even die. Chemical reactions double for every 14/sup 0/F rise in temperature. So, if you try to grow a plant at 100/sup 0/F that was originally growing at 86/sup 0/F, it will double its respiration rate. Adding carbon dioxide increases the rate of photosynthesis in plants, which increases the plant's food reserves. What carbon dioxide does to allow some plants to grow at temperatures at which they would otherwise not survive and it allows other plants to grow for longer periods at 100/sup 0/F. One problem with the process, says Converse, is that the longer plants are exposed to heat the greater the mutation rate. So, resulting clones should be closely examined for trueness to horticultural type.

  17. Elevated atmospheric carbon dioxide increases soil carbon

    SciTech Connect

    Norby, Richard J; Jastrow, Julie D; Miller, Michael R; Matamala, Roser; Boutton, Thomas W; Rice, Charles W; Owensby, Clenton E

    2005-01-01

    In a study funded by the U.S. Department of Energy's Office of Science, researchers from Argonne and Oak Ridge National Laboratories and Kansas State and Texas A&M Universities evaluated the collective results of earlier studies by using a statistical procedure called meta-analysis. They found that on average elevated CO2 increased soil carbon by 5.6 percent over a two to nine year period. They also measured comparable increases in soil carbon for Tennessee deciduous forest and Kansas grassland after five to eight years of experimental exposure to elevated CO2.

  18. Carbon dioxide reduction by the Bosch process

    NASA Technical Reports Server (NTRS)

    Manning, M. P.; Reid, R. C.

    1975-01-01

    Prototype units for carrying out the reduction of carbon dioxide to elementary carbon have been built and operated successfully. In some cases, however, startup difficulties have been reported. Moreover, the recycle reactor product has been reported to contain only small amounts of water and undesirably high yields of methane. This paper presents the results of the first phase of an experimental study that was carried out to define the mechanisms occurring in the reduction process. Conclusions are drawn and possible modifications to the present recycle process are suggested.

  19. Growth at elevated ozone or elevated carbon dioxide concentration alters antioxidant capacity and response to acute oxidative stress in soybean (Glycine max)

    SciTech Connect

    Gillespie, K.M.; Rogers, A.; Ainsworth, E. A.

    2011-01-31

    Soybeans (Glycine max Merr.) were grown at elevated carbon dioxide concentration ([CO{sub 2}]) or chronic elevated ozone concentration ([O{sub 3}]; 90 ppb), and then exposed to an acute O{sub 3} stress (200 ppb for 4 h) in order to test the hypothesis that the atmospheric environment alters the total antioxidant capacity of plants, and their capacity to respond to an acute oxidative stress. Total antioxidant metabolism, antioxidant enzyme activity, and antioxidant transcript abundance were characterized before, immediately after, and during recovery from the acute O{sub 3} treatment. Growth at chronic elevated [O{sub 3}] increased the total antioxidant capacity of plants, while growth at elevated [CO{sub 2}] decreased the total antioxidant capacity. Changes in total antioxidant capacity were matched by changes in ascorbate content, but not phenolic content. The growth environment significantly altered the pattern of antioxidant transcript and enzyme response to the acute O{sub 3} stress. Following the acute oxidative stress, there was an immediate transcriptional reprogramming that allowed for maintained or increased antioxidant enzyme activities in plants grown at elevated [O{sub 3}]. Growth at elevated [CO{sub 2}] appeared to increase the response of antioxidant enzymes to acute oxidative stress, but dampened and delayed the transcriptional response. These results provide evidence that the growth environment alters the antioxidant system, the immediate response to an acute oxidative stress, and the timing over which plants return to initial antioxidant levels. The results also indicate that future elevated [CO{sub 2}] and [O{sub 3}] will differentially affect the antioxidant system.

  20. Carbon Dioxide Flux in Mixed-grass Prairie: Response to Interannual Variation in Rainfall and Grazing History

    NASA Astrophysics Data System (ADS)

    Esposito, D.

    2002-12-01

    Grasslands are an important biome in the exchange of carbon between the biosphere and the atmosphere. However, our understanding of how carbon flux varies due to changes in precipitation, including drought conditions and land use history (grazing intensity) is only rudimentary. In this study we have evaluated the effects of adequate precipitation versus drought on net carbon flux, ecosystem respiration, and gross photosynthesis over three years (1998, 1999, and 2002) using chamber techniques. In addition, during 2002 measurements were taken across three grazing regimes (light, heavy, and ungrazed). Precipitation, or lack thereof, in 2002 made for a drought year compared to 1998 and 1999. The maximum rate of net carbon flux was lowest in 2002 at 3 mmol m-2 s-1 and highest in 1998 at 9 mmol m-2 s-1. Due to the drought conditions of 2002 grazing history had no affect on net flux rates. We propose that precipitation is the overriding factor that controls carbon flux in the mixed-grass prairie ecosystem, while land use has only marginal effects. Further data collected in a non-drought year is needed to corroborate this land use hypothesis.

  1. Carbon dioxide on the early earth.

    PubMed

    Walker, J C

    1985-01-01

    This paper uses arguments of geochemical mass balance to arrive at an estimate of the partial pressure of carbon dioxide in the terrestrial atmosphere very early in earth history. It appears that this partial pressure could have been as large as 10 bars. This large estimate depends on two key considerations. First, volatiles were driven out of the interior of the earth during the course of earth accretion or very shortly thereafter. This early degassing was a consequence of rapid accretion,which gave the young earth a hot and rapidly convecting interior. Second, the early earth lacked extensive, stable continental platforms on which carbon could be stored in the form of carbonate minerals for geologically significant periods of time. In the absence of continental platforms on the early earth, the earth's carbon must have been either in the atmosphere or ocean or in the form of shortlived sedimentary deposits on ephemeral sea floor.

  2. Carbon Dioxide Emissions Resulting from Space Tourism

    NASA Astrophysics Data System (ADS)

    Fawkes, S.

    An earlier paper by the author examined the links between space tourism and sustainable development. One important aspect of sustainable development is environmental impact and within that anthropogenic greenhouse gas emission is a key issue as it is linked to climate change. Space tourism operators need to consider the environmental impact of their operations and in particular measure their total carbon emissions (“carbon footprint”) and then put in place arrangements to reduce or offset them. This paper presents some initial calculations on the carbon dioxide emissions likely to result from both sub-orbital and orbital space tourism flights and discusses options and prices for carbon offsetting. The effect of scaling up the space tourism industry is also considered.

  3. Will peak oil accelerate carbon dioxide emissions?

    NASA Astrophysics Data System (ADS)

    Caldeira, K.; Davis, S. J.; Cao, L.

    2008-12-01

    The relative scarcity of oil suggests that oil production is peaking and will decline thereafter. Some have suggested that this represents an opportunity to reduce carbon dioxide emissions. However, in the absence of constraints on carbon dioxide emission, "peak oil" may drive a shift towards increased reliance on coal as a primary energy source. Because coal per unit energy, in the absence of carbon capture and disposal, releases more carbon dioxide to the atmosphere than oil, "peak oil" may lead to an acceleration of carbon dioxide emissions. We will never run out of oil. As oil becomes increasingly scarce, prices will rise and therefore consumption will diminish. As prices rise, other primary energy sources will become increasingly competitive with oil. The developed world uses oil primarily as a source of transportation fuels. The developing world uses oil primarily for heat and power, but the trend is towards increasing reliance on oil for transportation. Liquid fuels, including petroleum derivatives such as gasoline and diesel fuel, are attractive as transportation fuels because of their relative abundance of energy per unit mass and volume. Such considerations are especially important for the air transport industry. Today, there is little that can compete with petroleum-derived transportation fuels. Future CO2 emissions from the transportation sector largely depend on what replaces oil as a source of fuel. Some have suggested that biomass-derived ethanol, hydrogen, or electricity could play this role. Each of these potential substitutes has its own drawbacks (e.g., low power density per unit area in the case of biomass, low power density per unit volume in the case of hydrogen, and low power density per unit mass in the case of battery storage). Thus, it is entirely likely that liquefaction of coal could become the primary means by which transportation fuels are produced. Since the burning of coal produces more CO2 per unit energy than does the burning of

  4. Automated carbon dioxide cleaning system

    NASA Technical Reports Server (NTRS)

    Hoppe, David T.

    1991-01-01

    Solidified CO2 pellets are an effective blast media for the cleaning of a variety of materials. CO2 is obtained from the waste gas streams generated from other manufacturing processes and therefore does not contribute to the greenhouse effect, depletion of the ozone layer, or the environmental burden of hazardous waste disposal. The system is capable of removing as much as 90 percent of the contamination from a surface in one pass or to a high cleanliness level after multiple passes. Although the system is packaged and designed for manual hand held cleaning processes, the nozzle can easily be attached to the end effector of a robot for automated cleaning of predefined and known geometries. Specific tailoring of cleaning parameters are required to optimize the process for each individual geometry. Using optimum cleaning parameters the CO2 systems were shown to be capable of cleaning to molecular levels below 0.7 mg/sq ft. The systems were effective for removing a variety of contaminants such as lubricating oils, cutting oils, grease, alcohol residue, biological films, and silicone. The system was effective on steel, aluminum, and carbon phenolic substrates.

  5. Method of immobilizing carbon dioxide from gas streams

    DOEpatents

    Holladay, David W.; Haag, Gary L.

    1979-01-01

    This invention is a method for rapidly and continuously immobilizing carbon dioxide contained in various industrial off-gas streams, the carbon dioxide being immobilized as dry, stable, and substantially water-insoluble particulates. Briefly, the method comprises passing the gas stream through a fixed or fluidized bed of hydrated barium hydroxide to remove and immobilize the carbon dioxide by converting the bed to barium carbonate. The method has several important advantages: it can be conducted effectively at ambient temperature; it provides a very rapid reaction rate over a wide range of carbon dioxide concentrations; it provides high decontamination factors; and it has a high capacity for carbon dioxide. The invention is especially well suited for the removal of radioactive carbon dioxide from off-gases generated by nuclear-fuel reprocessing facilities and nuclear power plants.

  6. Response to: “Long-term effectiveness and consequences of carbon dioxide sequestration” by Gary Shaffer, published in Nature Geosciences, 27 June 2010.

    SciTech Connect

    Dooley, James J.

    2010-07-12

    Shaffer’s (2010) article reports on the long term impact of less than perfect retention of anthropogenic CO2 stored in deep geologic reservoirs and in the ocean. The central thesis of this article is predicated on two deeply flawed assumptions. The first and most glaring is the implicit assumption that society has only one means of reducing greenhouse gas emissions, carbon dioxide capture and storage (CCS). Secondly, there is absolutely no geophysical nor geomechanical basis for assuming an exponential decay of CO2 stored in deep geologic formations as done by Schaffer. Shaffer’s analysis of the impact of leakage from anthropogenic CO2 stored in deep geologic reservoirs are based upon two fundamentally flawed assumptions and therefore the reported results as well as the public policy conclusions presented in the paper need to be read with this understanding in mind as far less CO2 stored below ground because society drew upon a broad portfolio of advanced energy technologies over the coming century coupled with a more technically accurate conceptualization of CO2 storage in the deep subsurface and the important role of secondary and tertiary trapping mechanisms would have yield a far less pessimistic view of the potential role that CCS can play in a broader portfolio of societal responses to the very serious threat posed by climate change.

  7. Carbon Dioxide Transport through Membranes*

    PubMed Central

    Missner, Andreas; Kügler, Philipp; Saparov, Sapar M.; Sommer, Klaus; Mathai, John C.; Zeidel, Mark L.; Pohl, Peter

    2008-01-01

    Several membrane channels, like aquaporin-1 (AQP1) and the RhAG protein of the rhesus complex, were hypothesized to be of physiological relevance for CO2 transport. However, the underlying assumption that the lipid matrix imposes a significant barrier to CO2 diffusion was never confirmed experimentally. Here we have monitored transmembrane CO2 flux (JCO2) by imposing a CO2 concentration gradient across planar lipid bilayers and detecting the resulting small pH shift in the immediate membrane vicinity. An analytical model, which accounts for the presence of both carbonic anhydrase and buffer molecules, was fitted to the experimental pH profiles using inverse problems techniques. At pH 7.4, the model revealed that JCO2 was entirely rate-limited by near-membrane unstirred layers (USL), which act as diffusional barriers in series with the membrane. Membrane tightening by sphingomyelin and cholesterol did not alter JCO2 confirming that membrane resistance was comparatively small. In contrast, a pH-induced shift of the CO2 hydration-dehydration equilibrium resulted in a relative membrane contribution of about 15% to the total resistance (pH 9.6). Under these conditions, a membrane CO2 permeability (3.2 ± 1.6 cm/s) was estimated. It indicates that cellular CO2 uptake (pH 7.4) is always USL-limited, because the USL size always exceeds 1 μm. Consequently, facilitation of CO2 transport by AQP1, RhAG, or any other protein is highly unlikely. The conclusion was confirmed by the observation that CO2 permeability of epithelial cell monolayers was always the same whether AQP1 was overexpressed in both the apical and basolateral membranes or not. PMID:18617525

  8. Carbon Dioxide Sequestration: An Introduction

    SciTech Connect

    Oelkers, Dr. Eric; Cole, David R

    2008-01-01

    The success of human and industrial development over the past hundred years has lead to a huge increase in fossil fuel consumption and CO2 emission to the atmosphere leading to an unprecedented increase in atmospheric CO2 concentration. This increased CO2 content is believed to be responsible for a significant increase in global temperature over the past several decades. Global-scale climate modeling suggests that this temperature increase will continue at least over the next few hundred years leading to glacial melting, and raising seawater levels. In an attempt to attenuate this possibility, many have proposed the large scale sequestration of CO2 from our atmosphere. This introduction presents a summary of some of the evidence linking increasing atmosphere CO2 concentration to global warming and our efforts to stem this rise though CO2 sequestration.

  9. Assessing Effects of Rising Carbon Dioxide Levels on Ocean Ecosystems

    NASA Astrophysics Data System (ADS)

    Lance, Veronica P.

    2009-07-01

    Carbon Productivity Responses to Increased Dissolved Inorganic Carbon Concentrations in Surface Ocean: Exploring the Feasibility of an in Situ Mesoscale Carbon Addition Experiment; Palisades, New York, 23-24 March 2009; To assess the effects of future elevated carbon dioxide (CO2) levels on ocean biogeochemistry and ecosystems, it is desirable to mimic such an environment in nature. A workshop to explore an in situ open ocean mesoscale CO2 perturbation experiment that would simulate the oceanic conditions expected toward the end of this century was held at Lamont-Doherty Earth Observatory at Columbia University (LDEO). The objectives were to evaluate the current understanding of the potential effects on open ocean ecosystems and biogeochemical cycling resulting from carbon chemistry and pH changes in response to increased atmospheric partial pressure of carbon dioxide (pCO2) and to examine the scientific justification and logistical feasibility of an in situ open ocean mesoscale CO2/pH perturbation experiment. The 15 participants represented fields of modeling and physical, geochemical, and biological oceanography.

  10. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    SciTech Connect

    David A. Green; Brian S. Turk; Raghubir P. Gupta; Alejandro Lopez-Ortiz; Douglas P. Harrison; Ya Liang

    2001-07-01

    Sodium based sorbents including sodium carbonate may be used to capture carbon dioxide from flue gas. A relatively concentrated carbon dioxide stream may be recoverable for sequestration when the sorbent is regenerated. Electrobalance tests indicated that sodium carbonate monohydrate was formed in a mixture of helium and water vapor at temperatures below 65 C. Additional compounds may also form, but this could not be confirmed. In the presence of carbon dioxide and water vapor, both the initial reaction rate of sodium carbonate with carbon dioxide and water and the sorbent capacity decreased with increasing temperature, consistent with the results from the previous quarter. Increasing the carbon dioxide concentration at constant temperature and water vapor concentration produced a measurable increase in rate, as did increasing the water vapor concentration at constant carbon dioxide concentration and temperature. Runs conducted with a flatter TGA pan resulted in a higher initial reaction rate, presumably due to improved gas-solid contact, but after a short time, there was no significant difference in the rates measured with the different pans. Analyses of kinetic data suggest that the surface of the sodium carbonate particles may be much hotter than the bulk gas due to the highly exothermic reaction with carbon dioxide and water, and that the rate of heat removal from the particle may control the reaction rate. A material and energy balance was developed for a cyclic carbonation/calcination process which captures about 26 percent of the carbon dioxide present in flue gas available at 250 C.

  11. Carbon Dioxide Separation Using Thermally Optimized Membranes

    NASA Astrophysics Data System (ADS)

    Young, J. S.; Jorgensen, B. S.; Espinoza, B. F.; Weimer, M. W.; Jarvinen, G. D.; Greenberg, A.; Khare, V.; Orme, C. J.; Wertsching, A. K.; Peterson, E. S.; Hopkins, S. D.; Acquaviva, J.

    2002-05-01

    The purpose of this project is to develop polymeric-metallic membranes for carbon dioxide separations that operate under a broad range of industrially relevant conditions not accessible with present membrane units. The last decade has witnessed a dramatic increase in the use of polymer membranes as an effective, economic and flexible tool for many commercial gas separations including air separation, the recovery of hydrogen from nitrogen, carbon monoxide, and methane mixtures, and the removal of carbon dioxide from natural gas. In each of these applications, high fluxes and excellent selectivities have relied on glassy polymer membranes which separate gases based on both size and solubility differences. To date, however, this technology has focused on optimizing materials for near ambient conditions. The development of polymeric materials that achieve the important combination of high selectivity, high permeability, and mechanical stability at temperatures significantly above 25oC and pressures above 10 bar, respectively, has been largely ignored. Consequently, there is a compelling rationale for the exploration of a new realm of polymer membrane separations. Indeed, the development of high temperature polymeric-metallic composite membranes for carbon dioxide separation at temperatures of 100-450 oC and pressures of 10-150 bar would provide a pivotal contribution with both economic and environmental benefits. Progress to date includes the first ever fabrication of a polymeric-metallic membrane that is selective from room temperature to 370oC. This achievement represents the highest demonstrated operating temperature at which a polymeric based membrane has successfully functioned. Additionally, we have generated the first polybenzamidizole silicate molecular composites. Finally, we have developed a technique that has enabled the first-ever simultaneous measurements of gas permeation and membrane compaction at elevated temperatures. This technique provides a unique

  12. The nature of carbon dioxide waters in Snaefellsnes, western Iceland

    USGS Publications Warehouse

    Arnorsson, S.; Barnes, I.

    1983-01-01

    Over 20 occurrences of thermal and non-thermal waters rich in carbon dioxide are known in the Snaefellsnes Peninsula of western Iceland. On the basis of the thermal, chemical and isotopic characteristics of these waters, and hydrological considerations, it is concluded that they represent meteoric waters which have seeped to variable depths into the bedrock. Ascending carbon dioxide gas originating from intrusions or the mantle mixes with the meteoric waters to produce carbon dioxide waters: at considerable depth in the case of the thermal carbon dioxide waters but close to the surface in the case of cold carbon dioxide waters. The occurrence of carbon dioxide waters cannot be regarded as evidence for underground geothermal reservoirs. ?? 1983.

  13. Effects of carbon dioxide on Penicillium chrysogenum: an autoradiographic study

    SciTech Connect

    Edwards, A.G.; Ho, C.S.

    1988-06-20

    Previous research has shown that dissolved carbon dioxide causes significant changes in submerged penicillin fermentations, such as stunted, swollen hyphae, increased branching, lower growth rates, and lower penicillin productivity. Influent carbon dioxide levels of 5 and 10% were shown through the use of autoradiography to cause an increase in chitin synthesis in submerged cultures of Penicillium chrysogenum. At an influent 5% carbon dioxide level, chitin synthesis is ca. 100% greater in the subapical region of P. chrysogenum hyphae than that of the control, in which there was no influent carbon dioxide. Influent carbon dioxide of 10% caused an increase of 200% in chitin synthesis. It is believed that the cell wall must be plasticized before branching can occur and that high amounts of dissolved carbon dioxide cause the cell to lose control of the plasticizing effect, thus the severe morphological changes occur.

  14. Enriching blast furnace gas by removing carbon dioxide.

    PubMed

    Zhang, Chongmin; Sun, Zhimin; Chen, Shuwen; Wang, Baohai

    2013-12-01

    Blast furnace gas (BF gas) produced in the iron making process is an essential energy resource for a steel making work. As compared with coke oven gas, the caloric value of BF gas is too low to be used alone as fuel in hot stove because of its high concentrations of carbon dioxide and nitrogen. If the carbon dioxide in BF gas could be captured efficiently, it would meet the increasing need of high caloric BF gas, and develop methods to reusing and/or recycling the separated carbon dioxide further. Focused on this, investigations were done with simple evaluation on possible methods of removing carbon dioxide from BF gas and basic experiments on carbon dioxide capture by chemical absorption. The experimental results showed that in 100 minutes, the maximum absorbed doses of carbon dioxide reached 20 g/100 g with ionic liquid as absorbent.

  15. Designed amyloid fibers as materials for selective carbon dioxide capture

    PubMed Central

    Li, Dan; Furukawa, Hiroyasu; Deng, Hexiang; Liu, Cong; Yaghi, Omar M.; Eisenberg, David S.

    2014-01-01

    New materials capable of binding carbon dioxide are essential for addressing climate change. Here, we demonstrate that amyloids, self-assembling protein fibers, are effective for selective carbon dioxide capture. Solid-state NMR proves that amyloid fibers containing alkylamine groups reversibly bind carbon dioxide via carbamate formation. Thermodynamic and kinetic capture-and-release tests show the carbamate formation rate is fast enough to capture carbon dioxide by dynamic separation, undiminished by the presence of water, in both a natural amyloid and designed amyloids having increased carbon dioxide capacity. Heating to 100 °C regenerates the material. These results demonstrate the potential of amyloid fibers for environmental carbon dioxide capture. PMID:24367077

  16. Carbon dioxide emission from bamboo culms.

    PubMed

    Zachariah, E J; Sabulal, B; Nair, D N K; Johnson, A J; Kumar, C S P

    2016-05-01

    Bamboos are one of the fastest growing plants on Earth, and are widely considered to have high ability to capture and sequester atmospheric carbon, and consequently to mitigate climate change. We tested this hypothesis by measuring carbon dioxide (CO2 ) emissions from bamboo culms and comparing them with their biomass sequestration potential. We analysed diurnal effluxes from Bambusa vulgaris culm surface and gas mixtures inside hollow sections of various bamboos using gas chromatography. Corresponding variations in gas pressure inside the bamboo section and culm surface temperature were measured. SEM micrographs of rhizome and bud portions of bamboo culms were also recorded. We found very high CO2 effluxes from culm surface, nodes and buds of bamboos. Positive gas pressure and very high concentrations of CO2 were observed inside hollow sections of bamboos. The CO2 effluxes observed from bamboos were very high compared to their carbon sequestration potential. Our measurements suggest that bamboos are net emitters of CO2 during their lifespan.

  17. Thermochemical generation of hydrogen and carbon dioxide

    NASA Technical Reports Server (NTRS)

    Lawson, Daniel D. (Inventor); England, Christopher (Inventor)

    1984-01-01

    Mixing of carbon in the form of high sulfur coal with sulfuric acid reduces the temperature of sulfuric acid decomposition from 830.degree. C. to between 300.degree. C. and 400.degree. C. The low temperature sulfuric acid decomposition is particularly useful in thermal chemical cycles for splitting water to produce hydrogen. Carbon dioxide is produced as a commercially desirable byproduct. Lowering of the temperature for the sulfuric acid decomposition or oxygen release step simplifies equipment requirements, lowers thermal energy input and reduces corrosion problems presented by sulfuric acid at conventional cracking temperatures. Use of high sulfur coal as the source of carbon for the sulfuric acid decomposition provides an environmentally safe and energy efficient utilization of this normally polluting fuel.

  18. Copolymerization of carbon dioxide and butadiene via a lactone intermediate.

    PubMed

    Nakano, Ryo; Ito, Shingo; Nozaki, Kyoko

    2014-04-01

    Although carbon dioxide has attracted broad interest as a renewable carbon feedstock, its use as a monomer in copolymerization with olefins has long been an elusive endeavour. A major obstacle for this process is that the propagation step involving carbon dioxide is endothermic; typically, attempted reactions between carbon dioxide and an olefin preferentially yield olefin homopolymerization. Here we report a strategy to circumvent the thermodynamic and kinetic barriers for copolymerizations of carbon dioxide and olefins by using a metastable lactone intermediate, 3-ethylidene-6-vinyltetrahydro-2H-pyran-2-one, which is formed by the palladium-catalysed condensation of carbon dioxide and 1,3-butadiene. Subsequent free-radical polymerization of the lactone intermediate afforded polymers of high molecular weight with a carbon dioxide content of 33 mol% (29 wt%). Furthermore, the protocol was applied successfully to a one-pot copolymerization of carbon dioxide and 1,3-butadiene, and one-pot terpolymerizations of carbon dioxide, butadiene and another 1,3-diene. This copolymerization technique provides access to a new class of polymeric materials made from carbon dioxide.

  19. CO/sub 2/ and plants: the response of plants to rising levels of atmospheric carbon dioxide

    SciTech Connect

    Lemon, E.R.

    1983-01-01

    This book presents information on the direct effects of increased atmospheric CO/sub 2/ on plants. The authors consider what we already know about plant responses to various CO/sub 2/ concentrations, then project what may happen at ambient levels up to 600 ppm. Formulation questions that must be answered if we are to quantify plant responses under changing conditions, they consider possible positive and negative effects of the steady increase of one of life's basic components.

  20. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Carbon dioxide analyzer calibration. 89... Equipment Provisions § 89.322 Carbon dioxide analyzer calibration. (a) Prior to its introduction into... instrument start-up and operation. Adjust the analyzer to optimize performance. (2) Zero the carbon...

  1. 40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Carbon dioxide analyzer calibration... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.524-78 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service and monthly thereafter the NDIR carbon...

  2. 40 CFR 91.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration... Provisions § 91.320 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service, and monthly thereafter, or within one month prior to the certification test, calibrate the NDIR carbon...

  3. 40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.524-78 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service and monthly thereafter the NDIR carbon...

  4. 40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.524-78 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service and monthly thereafter the NDIR carbon...

  5. 40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.524-78 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service and monthly thereafter the NDIR carbon...

  6. 40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.524-78 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service and monthly thereafter the NDIR carbon...

  7. Carbon Dioxide and the Greenhouse Effect: A Problem Evaluation Activity.

    ERIC Educational Resources Information Center

    Brewer, Carol A.; Beiswenger, Jane M.

    1993-01-01

    Describes exercises to examine the global carbon cycle. Students are asked to predict consequences of increased carbon dioxide emissions into the atmosphere and to suggest ways to mitigate problems associated with these higher levels of atmospheric carbon dioxide. A comparison modeling exercise examines some of the variables related to the success…

  8. Effect of Elevated Carbon Dioxide on Bronchial Epithelial Innate Immune Receptor Response to Organic Dust from Swine Confinement Barns

    PubMed Central

    Schneberger, D.; Cloonan, D.; DeVasure, J. M.; Bailey, K. L.; Romberger, D. J.; Wyatt, T. A.

    2015-01-01

    Hypercapnia is known to have immunoregulatory effects within the lung. Cell culture systems demonstrate this in both macrophages and alveolar cell lines, suggesting that alveoli are affected by changes in CO2 levels. We hypothesized that hypercapnia would also modulate human bronchial epithelial cell immune responses. Innate immune responses to Pam3CSK4 (TLR2 ligand), LPS (TLR4 ligand) and a complex innate immune stimulus, an extract from the organic dust of swine confinement barns (barn dust extract or BDE), were tested in a human bronchial epithelial cell line, BEAS-2B. Both TLR ligands showed a decrease in IL-6 and IL-8 production, and an increase in MCP-1 in response to elevated CO2 indicating an enhancement in cytokine production to hypercapnia. This change was not reflected in expression levels of TLR receptor RNA which remained unchanged in response to elevated CO2. Interestingly, barn dust showed an increase in IL-6, IL-8 and MCP-1 response at 9% CO2, suggesting that elevated CO2 exerts different effects on different stimuli. Our results show that airway epithelial cell immune responses to barn dust respond differently to hypercapnic conditions than individual TLR ligands. PMID:25921030

  9. Measuring the human contribution to atmospheric carbon dioxide

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2012-05-01

    Although it is well established that humans are responsible for the modern increase in atmospheric carbon dioxide concentrations, the precise emission rates of carbon dioxide and other environmentally important gases are less well known. Traditionally, the reported usages of coal, oil, and other commodities are used to estimate emission rates. Though this economics-based approach is thought to work well at global and national scales, uncertainties increase for smaller regional scales or time scales shorter than a year. Drawing on 6 years of gas concentration measurements taken every 2 weeks from an airplane at two sites over the northeastern United States, Miller et al. developed a system to measure the anthropogenic contribution to atmospheric gas concentrations that is independent of accounting-based approaches.

  10. Supercritical carbon dioxide: a solvent like no other.

    PubMed

    Peach, Jocelyn; Eastoe, Julian

    2014-01-01

    Supercritical carbon dioxide (scCO2) could be one aspect of a significant and necessary movement towards green chemistry, being a potential replacement for volatile organic compounds (VOCs). Unfortunately, carbon dioxide has a notoriously poor solubilising power and is famously difficult to handle. This review examines attempts and breakthroughs in enhancing the physicochemical properties of carbon dioxide, focusing primarily on factors that impact solubility of polar and ionic species and attempts to enhance scCO2 viscosity.

  11. Supercritical carbon dioxide: a solvent like no other

    PubMed Central

    Peach, Jocelyn

    2014-01-01

    Summary Supercritical carbon dioxide (scCO2) could be one aspect of a significant and necessary movement towards green chemistry, being a potential replacement for volatile organic compounds (VOCs). Unfortunately, carbon dioxide has a notoriously poor solubilising power and is famously difficult to handle. This review examines attempts and breakthroughs in enhancing the physicochemical properties of carbon dioxide, focusing primarily on factors that impact solubility of polar and ionic species and attempts to enhance scCO2 viscosity. PMID:25246947

  12. Warming reduces carbon losses from grassland exposed to elevated atmospheric carbon dioxide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The flux of carbon dioxide (CO2) between terrestrial ecosystems and the atmosphere may ameliorate or exacerbate climate change, depending on the relative responses of ecosystem photosynthesis and respiration to warming temperatures, rising atmospheric CO2, and altered precipitation. The combined eff...

  13. Production of dissolved organic carbon by Arctic plankton communities: Responses to elevated carbon dioxide and the availability of light and nutrients

    NASA Astrophysics Data System (ADS)

    Poulton, Alex J.; Daniels, Chris J.; Esposito, Mario; Humphreys, Matthew P.; Mitchell, Elaine; Ribas-Ribas, Mariana; Russell, Benjamin C.; Stinchcombe, Mark C.; Tynan, Eithne; Richier, Sophie

    2016-05-01

    The extracellular release of dissolved organic carbon (DOC) by phytoplankton is a potentially important source of labile organic carbon for bacterioplankton in pelagic ecosystems. In the context of increasing seawater partial pressure of CO2 (pCO2), via the oceanic absorption of elevated atmospheric CO2 (ocean acidification), several previous studies have reported increases to the relative amount of carbon fixed into particulates, via primary production (PP), and dissolved phases (DOC). During the summer of 2012 we measured DOC production by phytoplankton communities in the Nordic seas of the Arctic Ocean (Greenland, Norwegian and Barents Sea) from both in situ sampling and during three bioassay experiments where pCO2 levels (targets ~550 μatm, ~750 μatm, ~1000 μatm) were elevated relative to ambient conditions. Measurements of DOC production and PP came from 24 h incubations and therefore represent net DOC production rates, where an unknown portion of the DOC released has potentially been utilised by heterotrophic organisms. Production of DOC (net pDOC) by in situ communities varied from 0.09 to 0.64 mmol C m-3 d-1 (average 0.25 mmol C m-3 d-1), with comparative rates in two of the experimental bioassays (0.04-1.23 mmol C m-3 d-1) and increasing dramatically in the third (up to 5.88 mmol C m-3 d-1). When expressed as a fraction of total carbon fixation (i.e., PP plus pDOC), percentage extracellular release (PER) was 14% on average (range 2-46%) for in situ measurements, with PER in the three bioassays having a very similar range (2-50%). A marked increase in pDOC (and PER) was only observed in one of the bioassays where nutrient levels (nitrate, silicic acid) dropped dramatically relative to starting (ambient) concentrations; no pCO2 treatment effect on pDOC (or PER) was evident across the three experiments. Examination of in situ net pDOC (and PER) found significant correlations with decreasing silicic acid and increasing euphotic zone depth, indicating that

  14. Six-fold Coordinated Carbon Dioxide VI

    SciTech Connect

    Iota, V; Yoo, C; Klepeis, J; Jenei, Z

    2006-03-01

    Under standard conditions, carbon dioxide (CO{sub 2}) is a simple molecular gas and an important atmospheric constituent while silicon dioxide (SiO{sub 2}) is a covalent solid, and represents one of the fundamental minerals of the planet. The remarkable dissimilarity between these two group IV oxides is diminished at higher pressures and temperatures as CO{sub 2} transforms to a series of solid phases, from simple molecular to a fully covalent extended-solid V, structurally analogous to SiO{sub 2} tridymite. Here, we present the discovery of a new extended-solid phase of carbon dioxide (CO{sub 2}): a six-fold coordinated stishovite-like phase VI, obtained by isothermal compression of associated CO{sub 2}-II above 50GPa at 530-650K. Together with the previously reported CO{sub 2}-V and a-carbonia, this new extended phase indicates a fundamental similarity between CO{sub 2}--a prototypical molecular solid, and SiO{sub 2}--one of Earth's fundamental building blocks. The phase diagram suggests a limited stability domain for molecular CO{sub 2}-I, and proposes that the conversion to extended-network solids above 40-50 GPa occurs via intermediate phases II, III, and IV. The crystal structure of phase VI suggests strong disorder along the caxis in stishovite-like P4{sub 2}/mnm, with carbon atoms manifesting an average six-fold coordination within the framework of sp{sup 3} hybridization.

  15. Amorphous silica-like carbon dioxide.

    PubMed

    Santoro, Mario; Gorelli, Federico A; Bini, Roberto; Ruocco, Giancarlo; Scandolo, Sandro; Crichton, Wilson A

    2006-06-15

    Among the group IV elements, only carbon forms stable double bonds with oxygen at ambient conditions. At variance with silica and germania, the non-molecular single-bonded crystalline form of carbon dioxide, phase V, only exists at high pressure. The amorphous forms of silica (a-SiO2) and germania (a-GeO2) are well known at ambient conditions; however, the amorphous, non-molecular form of CO2 has so far been described only as a result of first-principles simulations. Here we report the synthesis of an amorphous, silica-like form of carbon dioxide, a-CO2, which we call 'a-carbonia'. The compression of the molecular phase III of CO2 between 40 and 48 GPa at room temperature initiated the transformation to the non-molecular amorphous phase. Infrared spectra measured at temperatures up to 680 K show the progressive formation of C-O single bonds and the simultaneous disappearance of all molecular signatures. Furthermore, state-of-the-art Raman and synchrotron X-ray diffraction measurements on temperature-quenched samples confirm the amorphous character of the material. Comparison with vibrational and diffraction data for a-SiO2 and a-GeO2, as well as with the structure factor calculated for the a-CO2 sample obtained by first-principles molecular dynamics, shows that a-CO2 is structurally homologous to the other group IV dioxide glasses. We therefore conclude that the class of archetypal network-forming disordered systems, including a-SiO2, a-GeO2 and water, must be extended to include a-CO2. PMID:16778885

  16. Selective free radical reactions using supercritical carbon dioxide.

    PubMed

    Cormier, Philip J; Clarke, Ryan M; McFadden, Ryan M L; Ghandi, Khashayar

    2014-02-12

    We report herein a means to modify the reactivity of alkenes, and particularly to modify their selectivity toward reactions with nonpolar reactants (e.g., nonpolar free radicals) in supercritical carbon dioxide near the critical point. Rate constants for free radical addition of the light hydrogen isotope muonium to ethylene, vinylidene fluoride, and vinylidene chloride in supercritical carbon dioxide are compared over a range of pressures and temperatures. Near carbon dioxide's critical point, the addition to ethylene exhibits critical speeding up, while the halogenated analogues display critical slowing. This suggests that supercritical carbon dioxide as a solvent may be used to tune alkene chemistry in near-critical conditions.

  17. A tenuous carbon dioxide atmosphere on Jupiter's moon Callisto.

    PubMed

    Carlson, R W

    1999-02-01

    An off-limb scan of Callisto was conducted by the Galileo near-infrared mapping spectrometer to search for a carbon dioxide atmosphere. Airglow in the carbon dioxide nu3 band was observed up to 100 kilometers above the surface and indicates the presence of a tenuous carbon dioxide atmosphere with surface pressure of 7.5 x 10(-12) bar and a temperature of about 150 kelvin, close to the surface temperature. A lifetime on the order of 4 years is suggested, based on photoionization and magnetospheric sweeping. Either the atmosphere is transient and was formed recently or some process is currently supplying carbon dioxide to the atmosphere.

  18. Carbon dioxide absorbent and method of using the same

    SciTech Connect

    Perry, Robert James; O'Brien, Michael Joseph

    2014-06-10

    In accordance with one aspect, the present invention provides a composition which contains the amino-siloxane structures I, or III, as described herein. The composition is useful for the capture of carbon dioxide from process streams. In addition, the present invention provides methods of preparing the amino-siloxane composition. Another aspect of the present invention provides methods for reducing the amount of carbon dioxide in a process stream employing the amino-siloxane compositions of the invention, as species which react with carbon dioxide to form an adduct with carbon dioxide.

  19. Carbon dioxide absorbent and method of using the same

    SciTech Connect

    Perry, Robert James; O'Brien, Michael Joseph

    2015-12-29

    In accordance with one aspect, the present invention provides a composition which contains the amino-siloxane structures I, or III, as described herein. The composition is useful for the capture of carbon dioxide from process streams. In addition, the present invention provides methods of preparing the amino-siloxane composition. Another aspect of the present invention provides methods for reducing the amount of carbon dioxide in a process stream employing the amino-siloxane compositions of the invention, as species which react with carbon dioxide to form an adduct with carbon dioxide.

  20. A tenuous carbon dioxide atmosphere on Jupiter's moon Callisto

    NASA Technical Reports Server (NTRS)

    Carlson, R. W.

    1999-01-01

    An off-limb scan of Callisto was conducted by the Galileo near-infrared mapping spectrometer to search for a carbon dioxide atmosphere. Airglow in the carbon dioxide nu3 band was observed up to 100 kilometers above the surface and indicates the presence of a tenuous carbon dioxide atmosphere with surface pressure of 7.5 x 10(-12) bar and a temperature of about 150 kelvin, close to the surface temperature. A lifetime on the order of 4 years is suggested, based on photoionization and magnetospheric sweeping. Either the atmosphere is transient and was formed recently or some process is currently supplying carbon dioxide to the atmosphere.

  1. Preparation of perlite-based carbon dioxide absorbent.

    PubMed

    He, H; Wu, L; Zhu, J; Yu, B

    1994-02-01

    A new highly efficient carbon dioxide absorbent consisting of sodium hydroxide, expanded perlite and acid-base indicator was prepared. The absorption efficiency, absorption capacity, flow resistance and color indication for the absorbent were tested and compared with some commercial products. The absorbent can reduce the carbon dioxide content in gases to 3.3 ppb (v/v) and absorbs not less than 35% of its weight of carbon dioxide. Besides its large capacity and sharp color indication, the absorbent has an outstanding advantage of small flow resistance in comparison with other commercial carbon dioxide absorbents. Applications in gas analysis and purification were also investigated.

  2. Capture of carbon dioxide by hybrid sorption

    SciTech Connect

    Srinivasachar, Srivats

    2014-09-23

    A composition, process and system for capturing carbon dioxide from a combustion gas stream. The composition has a particulate porous support medium that has a high volume of pores, an alkaline component distributed within the pores and on the surface of the support medium, and water adsorbed on the alkaline component, wherein the proportion of water in the composition is between about 5% and about 35% by weight of the composition. The process and system contemplates contacting the sorbent and the flowing gas stream together at a temperature and for a time such that some water remains adsorbed in the alkaline component when the contact of the sorbent with the flowing gas ceases.

  3. Searching for clues to ancient carbon dioxide

    SciTech Connect

    Appenzeller, T.

    1993-02-12

    Something on Earth just won't stop fiddling with the thermostat. In the past 500 million years, the planet has shivered through ice ages lasting millions of years and sweltered through episodes of global warmth. Climatologists, eager to know what keeps jiggling the planet's temperature setting, have focused their suspicions on carbon dioxide, the same heat-trapping gas expected to drive up temperatures in coming decades. Catching this suspect in the act has been difficult, however; the atmospheres of millions of years ago are gone with the wind.

  4. Electrochemical carbon dioxide concentrator subsystem development

    NASA Technical Reports Server (NTRS)

    Heppner, D. B.; Dahlausen, M. J.; Schubert, F. H.

    1983-01-01

    The fabrication of a one-person Electrochemical Depolarized Carbon Dioxide Concentrator subsystem incorporating advanced electrochemical, mechanical, and control and monitor instrumentation concepts is discussed. This subsystem included an advanced liquid cooled unitized core composite cell module and integrated electromechanical components. Over 1800 hours with the subsystem with removal efficiencies between 90%. and 100%; endurance tests with a Fluid Control Assembly which integrates 11 gas handling components of the subsystem; and endurance testing of a coolant control assembly which integrates a coolant pump, diverter valve and a liquid accumulator were completed.

  5. High-pressure vapor-liquid equilibria of two binary systems: Carbon dioxide + cyclohexanol and carbon dioxide + cyclohexanone

    SciTech Connect

    Laugier, S.; Richon, D.

    1997-01-01

    Vapor-liquid equilibria for carbon dioxide + cyclohexanol and carbon dioxide + cyclohexanone were measured using an apparatus based on a static-analytic method with in situ samplings. P, T, x, y measurements were made at pressures up to 22 MPa. The carbon dioxide + cyclohexanol system was studied at 433 and 473 K, and carbon dioxide + cyclohexanone, at 433 and 473 K. The results are correlated by the Redlich-Kwong-Soave and Peng and Robinson equations and several mixing rules. The best fittings are obtained with the Peng-Robinson equation of state and a two-parameter mixing rule, i.e., within 1.1% for both pressures and vapor mole fractions on the carbon dioxide + cyclohexanone system and within 1.9% for pressures and 2.9% for vapor mole fractions on the carbon dioxide + cyclohexanol system. More recent equations by Patel and Teja and Salim and Trebble show no significant advantages.

  6. Climate response to changes in atmospheric carbon dioxide and solar irradiance on the time scale of days to weeks

    NASA Astrophysics Data System (ADS)

    Cao, Long; Bala, Govindasamy; Caldeira, Ken

    2012-09-01

    Recent studies show that fast climate response on time scales of less than a month can have important implications for long-term climate change. In this study, we investigate climate response on the time scale of days to weeks to a step-function quadrupling of atmospheric CO2 and contrast this with the response to a 4% increase in solar irradiance. Our simulations show that significant climate effects occur within days of a stepwise increase in both atmospheric CO2 content and solar irradiance. Over ocean, increased atmospheric CO2 warms the lower troposphere more than the surface, increasing atmospheric stability, moistening the boundary layer, and suppressing evaporation and precipitation. In contrast, over ocean, increased solar irradiance warms the lower troposphere to a much lesser extent, causing a much smaller change in evaporation and precipitation. Over land, both increased CO2 and increased solar irradiance cause rapid surface warming that tends to increase both evaporation and precipitation. However, the physiological effect of increased atmospheric CO2 on plant stomata reduces plant transpiration, drying the boundary layer and decreasing precipitation. This effect does not occur with increased solar irradiance. Therefore, differences in climatic effects from CO2 versus solar forcing are manifested within days after the forcing is imposed.

  7. Response of a coupled ocean-atmosphere model to increasing atmospheric carbon dioxide: Sensitivity to the rate of increase

    SciTech Connect

    Stouffer, R.J.

    1999-08-01

    The influence of differing rates of increase of the atmospheric CO{sub 2} concentration on the climatic response is investigated using a coupled ocean-atmosphere model. Five transient integrations are performed each using a different constant exponential rate of CO{sub 2} increase ranging from 4% yr{sup {minus}1} to 0.25% yr{sup {minus}1}. By the time of CO{sub 2} doubling, the surface air temperature response in all the transient integrations is locally more than 50% and globally more than 35% of the equilibrium response. The land-sea contrast in the warming, which is evident in the equilibrium results, is larger in all the transient experiments. The land-sea difference in the response increases with the rate of increase in atmospheric CO{sub 2} concentration. The thermohaline circulation (THC) weakens in response to increasing atmospheric CO{sub 2} concentration in all the transient integrations, confirming earlier work. The results also indicate that the slower the rate of increase, the larger the weakening of the THC by the time of doubling. Two of the transient experiments are continued beyond the time of CO{sub 2} doubling with the CO{sub 2} concentration maintained at that level. The amount of weakening of the THC after the CO{sub 2} stops increasing is smaller in the experiment with the slower rate of CO{sub 2} increase, indicating that the coupled system has more time to adjust to the forcing when the rate of CO{sub 2} increase is slower. After a period of slow overturning, the THC gradually recovers and eventually regains the intensity found in the control integration, so that the equilibrium THC is very similar in the control and doubled CO{sub 2} integrations. Considering only the sea level changes due to the thermal expansion of seawater, the integration with the slowest rate of increase in CO{sub 2} concentration has the largest globally averaged sea level rise by the time of CO{sub 2} doubling. However, only a relatively small fraction of the

  8. Effects of carbon dioxide exposure on intensively cultured rainbow trout Oncorhynchus mykiss: Physiological responses and fillet attributes

    USGS Publications Warehouse

    Danley, M.L.; Kenney, P.B.; Mazik, P.M.; Kiser, R.; Hankins, J.A.

    2005-01-01

    Rainbow trout Oncorhynchus mykiss (261.6 ?? 24.7 g initial weight, mean ?? SEM) at 13.1 ?? 0.2 C were exposed for 94 d to one of three CO2 treatments: control (22.1 ?? 2.8 mg/L), medium (34.5 ?? 3.8 mg/L), or high (48.7 ?? 4.4 mg/L). Trout were checked daily for survival, and fish were sampled at 0, 28, 56, and 84 d for physiological responses, growth, and fillet quality assessments. Trout were also challenged to a 15-min crowding stress at 93 d to assess their ability to initiate a stress response during hypercapnia. Chronically exposed trout showed nearly 100% survival through 84 d exposure (1 of 1,500 fish died). Growth and physiological results showed that increasing elevated CO2 concentrations result in corresponding decreased growth rates and CO2-specific physiological parameters: The medium and high CO2 treatments had significantly slower growth and subsequently smaller fish by 84 d. Exposed trout also showed significantly (P < 0.05) decreased plasma chloride for medium and high CO2 treatments compared to the control from 28 through 84 d. Decreased growth and smaller fish in the medium and high CO2 treatments resulted in correspondingly smaller fresh and smoked fillet weights. Chronic CO2 exposure did not result in notable changes in ultimate muscle pH. Exposure to 15-min crowding stress at 93 d resulted in significant changes in hematocrit, plasma cortisol, glucose, and chloride for all treatment groups. CO2-specific changes were detected in hematocrit, plasma cortisol, and plasma chloride responses following the 15-min crowding stress. ?? Copyright by the World Aquaculture Society 2005.

  9. Field studies of sweet potatoes and cowpeas in response to elevated carbon dioxide. Progress report. [Ipomoea batatas; Vigna unguiculata

    SciTech Connect

    Biswas, P.K.

    1985-01-01

    The physiological and biochemical effects of enriched CO/sub 2/ on sweet potatoes and cowpeas were studied in open top chambers. The main task was to assemble equipment to generate test atmospheres of CO/sub 2/ in the field, using open top chambers as the basic exposure unit for studying the response of sweet potatoes and cowpeas to enriched CO/sub 2/. Plant responses to CO/sub 2/ in open top chambers have been demonstrated by several investigators in a variety of crops. This study focused on growth and development of both sweet potatoes and cowpeas at levels of CO/sub 2/ ranging from the ambient level of 354 ppM to 659 ppM. The effects of CO/sub 2/ on leaf and stem weights, stem length, leaf area, and stomatal number and conductance were studied on both species. Additional studies on sweet potatoes included the effects of CO/sub 2/ on the weight, chemical content and quality of tubers. Additional studies on cowpeas included the effects of CO/sub 2/ on the weight of seeds and rate of nitrogen fixation. 27 figs., 35 tabs. (ACR)

  10. Photosynthetic Response to Long- and Short-Term Changes in Carbon Dioxide in Sweetpotatoes Grown Hydroponically with Enhanced Mineral Nutrition

    NASA Technical Reports Server (NTRS)

    Hamilton, Casey; Terse, Anita; Hileman, Douglas R.; Mortley, Desmond G.; Hill, Jill

    1998-01-01

    Sweetpotato [Ipomoea batatas L.(Lam.)] has been selected by NASA as a potential food for long-term space missions. In previous experiments, sweetpotato plants grown hydroponically under elevated levels of CO2 depleted the nitrogen in the nutrient solution between the hi-weekly solution replacements. In this experiment, the effect of enhanced nutrient replenishment on photosynthetic rates of sweetpotato was determined. CO2 response curves were determined for "TU-82-155" and "Georgia-Jet" sweetpotatoes grown hydroponically in growth chambers at three different CO2 concentrations (400, 750, and 1000 micro-mol/mol CO2). Gas exchange measurements were made using infrared gas analysis, an open-flow gas exchange system, and a controlled-climate cuvette. Photosynthetic measurements were made at CO2 concentrations from 50-1000 micro-mol/mol CO2. Net photosynthetic rates showed an increase with increasing measurement CO2 in all nutrient regimes, but the response of photosynthetic rates to the growth CO2 conditions varied among the experiments and between the two varieties. Enhanced mineral nutrition led to increased net photosynthetic rates in "Georgia Jet" plants, but not in "TU-82-155" plants. The results of this study will help to determine the CO2 requirements for growth of sweetpotato on proposed space missions.

  11. Vascular response to carbon dioxide in areas with and without diaschisis in patients with small, deep hemispheric infarction

    SciTech Connect

    Takano, T.; Nagatsuka, K.; Ohnishi, Y.; Takamitsu, Y.; Matsuo, H.; Matsumoto, M.; Kimura, K.; Kamada, T.

    1988-07-01

    The reactivity of cerebral blood vessels to changes in PaCO/sub 2/ in areas of the cerebral cortex with or without diaschisis was investigated in 13 patients in a subacute or chronic stage after a small capsular infarct. A focal area of hypoperfusion (area of diaschisis) was detected in the ipsilateral sensorimotor cortex in each patient. Hyperventilation caused a significant reduction of regional cerebral blood flow in the area without diaschisis and only a tendency for regional cerebral blood flow to decrease in the area with diaschisis; CO/sub 2/ inhalation induced a slight increase in regional cerebral blood flow in the area without diaschisis and a significant increase in regional cerebral blood flow in the area with diaschisis. Regional cerebral blood flow reactivity to hypocapnia was significantly less in the area with diaschisis than in the area without, whereas the hypercapnic response was more marked in the area with diaschisis than in the area without. Our results suggest that in the area with diaschisis, the arterioles may be abnormally vasoconstricted at rest such that they cannot constrict further in response to hypocapnia but can dilate more during hypercapnia than in the area without diaschisis. This excessive resting vasoconstriction may result from decreased tissue elaboration of CO/sub 2/ due to local decrease of metabolic function.

  12. Effects of fuel and forest conservation on future levels of atmospheric carbon dioxide

    NASA Astrophysics Data System (ADS)

    Walker, James C. G.; Kasting, James F.

    1992-03-01

    We develop a numerical simulation of the global biogeochemical cycles of carbon that works over time scales extending from years to millions of years. The ocean is represented by warm and cold shallow water reservoirs, a thermocline reservoir, and deep Atlantic, Indian, and Pacific reservoirs. The atmosphere is characterized by a single carbon reservoir and the global biota by a single biomass reservoir. The simulation includes the rock cycle, distinguishing between shelf carbonate and pelagic carbonate precipitation, with distinct lysocline depths in the three deep ocean reservoirs. Dissolution of pelagic carbonates in response to decrease in lysocline depth is included. The simulation is tuned to reproduce the observed radiocarbon record resulting from atomic weapon testing. It is tuned also to reproduce the distribution of dissolved phosphate and total dissolved carbon between the ocean reservoirs as well as the carbon isotope ratios for both 13C and 14C in ocean and atmosphere. The simulation reproduces reasonably well the historical record of carbon dioxide partial pressure as well as the atmospheric isotope ratios for 13C and 14C over the last 200 yr as these have changed in response to fossil fuel burning and land use changes, principally forest clearance. The agreements between observation and calculation involves the assumption of a carbon dioxide fertilization effect in which the rate of production of biomass increases with increasing carbon dioxide partial pressure. At present the fertilization effect of increased carbon dioxide outweighs the effects of forest clearance, so the biota comprises an overall sink of atmosph ric carbon dioxide sufficiently large to bring the budget approximately into balance. This simulation is used to examine the future evolution of carbon dioxide and its sensitivity to assumptions about the rate of fossil fuel burning and of forest clearance. Over times extending up to thousands of years, the results are insensitive to the

  13. Effects of fuel and forest conservation on future levels of atmospheric carbon dioxide.

    PubMed

    Walker, J C; Kasting, J F

    1992-01-01

    We develop a numerical simulation of the global biogeochemical cycles of carbon that works over time scales extending from years to millions of years. The ocean is represented by warm and cold shallow water reservoirs, a thermocline reservoir, and deep Atlantic, Indian, and Pacific reservoirs. The atmosphere is characterized by a single carbon reservoir and the global biota by a single biomass reservoir. The simulation includes the rock cycle, distinguishing between shelf carbonate and pelagic carbonate precipitation, with distinct lysocline depths in the three deep ocean reservoirs. Dissolution of pelagic carbonates in response to decrease in lysocline depth is included. The simulation is tuned to reproduce the observed radiocarbon record resulting from atomic weapon testing. It is tuned also to reproduce the distribution of dissolved phosphate and total dissolved carbon between the ocean reservoirs as well as the carbon isotope ratios for both 13C and 14C in ocean and atmosphere. The simulation reproduces reasonably well the historical record of carbon dioxide partial pressure as well as the atmospheric isotope ratios for 13C and 14C over the last 200 yr as these have changed in response to fossil fuel burning and land use changes, principally forest clearance. The agreements between observation and calculation involves the assumption of a carbon dioxide fertilization effect in which the rate of production of biomass increases with increasing carbon dioxide partial pressure. At present the fertilization effect of increased carbon dioxide outweighs the effects of forest clearance, so the biota comprises an overall sink of atmospheric carbon dioxide sufficiently large to bring the budget approximately into balance. This simulation is used to examine the future evolution of carbon dioxide and its sensitivity to assumptions about the rate of fossil fuel burning and of forest clearance. Over times extending up to thousands of years, the results are insensitive to the

  14. Effects of fuel and forest conservation on future levels of atmospheric carbon dioxide.

    PubMed

    Walker, J C; Kasting, J F

    1992-01-01

    We develop a numerical simulation of the global biogeochemical cycles of carbon that works over time scales extending from years to millions of years. The ocean is represented by warm and cold shallow water reservoirs, a thermocline reservoir, and deep Atlantic, Indian, and Pacific reservoirs. The atmosphere is characterized by a single carbon reservoir and the global biota by a single biomass reservoir. The simulation includes the rock cycle, distinguishing between shelf carbonate and pelagic carbonate precipitation, with distinct lysocline depths in the three deep ocean reservoirs. Dissolution of pelagic carbonates in response to decrease in lysocline depth is included. The simulation is tuned to reproduce the observed radiocarbon record resulting from atomic weapon testing. It is tuned also to reproduce the distribution of dissolved phosphate and total dissolved carbon between the ocean reservoirs as well as the carbon isotope ratios for both 13C and 14C in ocean and atmosphere. The simulation reproduces reasonably well the historical record of carbon dioxide partial pressure as well as the atmospheric isotope ratios for 13C and 14C over the last 200 yr as these have changed in response to fossil fuel burning and land use changes, principally forest clearance. The agreements between observation and calculation involves the assumption of a carbon dioxide fertilization effect in which the rate of production of biomass increases with increasing carbon dioxide partial pressure. At present the fertilization effect of increased carbon dioxide outweighs the effects of forest clearance, so the biota comprises an overall sink of atmospheric carbon dioxide sufficiently large to bring the budget approximately into balance. This simulation is used to examine the future evolution of carbon dioxide and its sensitivity to assumptions about the rate of fossil fuel burning and of forest clearance. Over times extending up to thousands of years, the results are insensitive to the

  15. Responses of ecosystem carbon dioxide exchange to nitrogen addition in a freshwater marshland in Sanjiang Plain, Northeast China.

    PubMed

    Zhang, Lihua; Song, Changchun; Nkrumah, Philip N

    2013-09-01

    It has widely been documented that nitrogen (N) stimulates plant growth and net primary production. But how N affects net ecosystem CO2 exchange (NEE) is still dispute. We conduct an experimental study to assess the response of NEE to N addition in a freshwater marsh. Experimental treatments involved elevated N and control treatments on triplicate 1 m(2) plots. Gas exchange, air temperature, plant biomass and leaf area as well as N% of leaf were measured from 2004 to 2005. The results indicated that N addition initially decreased the CO2 sequestration but the trend changed in the second year. It was concluded that N addition enhanced the greenhouse effect in marshland as far as global warming potential (GWP) is concerned. This increase was attributed to a substantial increase in CH4 and N2O emissions after N addition. We recommended long-term studies to further clarify the effect of N addition on NEE. PMID:23727568

  16. The kinetics of binding carbon dioxide in magnesium carbonate

    SciTech Connect

    Butt, D.P.; Lackner, K.S.; Wendt, C.H.; Vaidya, R.; Pile, D.L.; Park, Y.; Holesinger, T.; Harradine, D.M.; Nomura, Koji |

    1998-08-01

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

  17. Dynamics of medullary hydrogen ion and respiratory responses to square-wave change of arterial carbon dioxide in cats.

    PubMed

    Eldridge, F L; Kiley, J P; Paydarfar, D

    1987-04-01

    1. The dynamics of changes of medullary extracellular fluid (ECF) hydrogen ion concentration ([H+]) and respiration, measured as integrated phrenic nerve activity, were determined in anaesthetized, paralysed, vagotomized and glomectomized cats. ECF [H+] was measured directly by means of a small (2 mm diameter) glass pH electrode placed on the ventral surface of the medulla. The variables were measured continuously after a step change of arterial PCO2 produced by abruptly starting or stopping an infusion of hypercapnic fluid into the aortic arch. 2. Alteration of pH in the descending thoracic aorta at the onset or offset of infusion was complete within 1.5 s after the change began, indicating that it was nearly square wave in form. 3. In sixteen experiments, ECF [H+] began to fall within 2 s of offset of infusion, reflecting aortic-medullary circulation time. Thereafter, ECF [H+] decreased to a stable level over the next 5 min; the curve describing the decrease consisted of two exponential functions, one with a time constant (tau) of 9.5 +/- 0.6 s and a second with a tau of 53 +/- 3 s. 4. We interpret the findings at the offset of CO2 infusion in terms of CO2 wash-out from the medullary ECF. The slow function is associated with wash-out during stable medullary blood flow that develops after 1 min. The early fast function is associated with the decreasing medullary blood flow that occurs during the first minute after change from arterial hypercapnia to normocapnia. 5. We have estimated medullary blood flow using a mathematical model incorporating the two functions. The values obtained are consistent with those in the literature where other methods have been used. Changes of blood flow following the step change of CO2 are fairly rapid, half of the response occurring in 13 s. 6. The change of respiratory activity lags the change of stimulus expressed by [H+], throughout the recovery period and respiration requires up to 8 min to reach a stable level. We attribute this

  18. Six-fold coordinated carbon dioxide VI

    SciTech Connect

    Iota, Valentin; Yoo, Choong-Shik; Klepeis, Jae-Hyun; Jenei, Zsolt; Evans, William; Cynn, Hyunchae

    2008-06-16

    Under standard conditions, carbon dioxide (CO{sub 2}) is a simple molecular gas and an important atmospheric constituent, whereas silicon dioxide (SiO{sub 2}) is a covalent solid, and one of the fundamental minerals of the planet. The remarkable dissimilarity between these two group IV oxides is diminished at higher pressures and temperatures as CO{sub 2} transforms to a series of solid phases, from simple molecular to a fully covalent extended-solid V, structurally analogous to SiO{sub 2} tridymite. Here, we present the discovery of an extended-solid phase of CO{sub 2}: a six-fold coordinated stishovite-like phase VI, obtained by isothermal compression of associated CO{sub 2}-II above 50 GPa at 530-650 K. Together with the previously reported CO{sub 2}-V and a-carbonia, this extended phase indicates a fundamental similarity between CO{sub 2} (a prototypical molecular solid) and SiO{sub 2} (one of Earth's fundamental building blocks). We present a phase diagram with a limited stability domain for molecular CO{sub 2}-I, and suggest that the conversion to extended-network solids above 40-50 GPa occurs via intermediate phases II, III and IV. The crystal structure of phase VI suggests strong disorder along the c axis in stishovite-like P4{sub 2}/mnm, with carbon atoms manifesting an average six-fold coordination within the framework of sp{sup 3} hybridization.

  19. Pharmaceutical applications of supercritical carbon dioxide.

    PubMed

    Kaiser, C S; Römpp, H; Schmidt, P C

    2001-12-01

    The appearance of a supercritical state was already observed at the beginning of the 19th century. Nevertheless, the industrial extraction of plant and other natural materials started about twenty years ago with the decaffeination of coffee. Today carbon dioxide is the most common gas for supercritical fluid extraction in food and pharmaceutical industry. Since pure supercritical carbon dioxide is a lipophilic solvent, mixtures with organic solvents, especially alcohols, are used to increase the polarity of the extraction fluid; more polar compounds can be extracted in this way. The main fields of interest are the extraction of vegetable oils from plant material in analytical and preparative scale, the preparation of essential oils for food and cosmetic industry and the isolation of substances of pharmaceutical relevance. Progress in research was made by the precise measurement of phase equilibria data by means of different methods. Apart from extraction, supercritical fluid chromatography was introduced in the field of analytics, as well as micro- and nanoparticle formation using supercritical fluids as solvent or antisolvent. This review presents pharmaceutical relevant literature of the last twenty years with special emphasis on extraction of natural materials.

  20. Pharmaceutical applications of supercritical carbon dioxide.

    PubMed

    Kaiser, C S; Römpp, H; Schmidt, P C

    2001-12-01

    The appearance of a supercritical state was already observed at the beginning of the 19th century. Nevertheless, the industrial extraction of plant and other natural materials started about twenty years ago with the decaffeination of coffee. Today carbon dioxide is the most common gas for supercritical fluid extraction in food and pharmaceutical industry. Since pure supercritical carbon dioxide is a lipophilic solvent, mixtures with organic solvents, especially alcohols, are used to increase the polarity of the extraction fluid; more polar compounds can be extracted in this way. The main fields of interest are the extraction of vegetable oils from plant material in analytical and preparative scale, the preparation of essential oils for food and cosmetic industry and the isolation of substances of pharmaceutical relevance. Progress in research was made by the precise measurement of phase equilibria data by means of different methods. Apart from extraction, supercritical fluid chromatography was introduced in the field of analytics, as well as micro- and nanoparticle formation using supercritical fluids as solvent or antisolvent. This review presents pharmaceutical relevant literature of the last twenty years with special emphasis on extraction of natural materials. PMID:11802652

  1. Shifts in the phylogenetic structure of arbuscular mycorrhizal fungi in response to experimental nitrogen and carbon dioxide additions.

    PubMed

    Mueller, Rebecca C; Bohannan, Brendan J M

    2015-09-01

    Global N inputs and atmospheric CO2 concentrations have increased as a result of human activities, and are predicted to increase along with population growth, with potentially negative effects on biodiversity. Using taxonomic and phylogenetic measures, we examined the response of arbuscular mycorrhizal fungi (AMF) to experimental manipulations of N and CO2 at the Jasper Ridge Global Change Experiment. No significant interactions between N and CO2 were observed, but individual effects of N and CO2 were found. Elevated CO2 resulted in changes in phylogenetic similarity, and a shift to phylogenetic clustering of AMF communities. N addition resulted in higher phylogenetic diversity and evenness, with no shifts in community composition and no significant signal for phylogenetic clustering. N addition resulted in an increase in both available N and the N:P ratio in N-amended plots, which suggests that changing patterns of nutrient limitation could have lead to altered species interactions. These findings suggest that elevated levels of N and CO2 altered patterns of AMF community assembly, with potential effects on ecosystem function. PMID:25990297

  2. Carbon dioxide extraction from air: Is it an option?

    SciTech Connect

    Lackner, K.S.; Grimes, P.; Ziock, H.J.

    1999-07-01

    Controlling the level of carbon dioxide in the atmosphere without limiting access to fossil energy resources is only possible if carbon dioxide is collected and disposed of away from the atmosphere. While it may be cost-advantageous to collect the carbon dioxide at concentrated sources without ever letting it enter the atmosphere, this approach is not available for the many diffuse sources of carbon dioxide. Similarly, for many older plants, a retrofit to collect the carbon dioxide is either impossible or prohibitively expensive. For these cases the authors investigate the possibility of collecting the carbon dioxide directly from the atmosphere. The authors conclude that there are no fundamental obstacles to this approach and that it deserves further investigation. Carbon dioxide extraction directly from the atmosphere would allow carbon management without the need for a completely changed infrastructure. In addition it eliminates the need for a completely changed infrastructure. In addition it eliminates the need for a complex carbon dioxide transportation infrastructure, thus at least in part offsetting the higher cost of extraction from air.

  3. Growth and yield response of field-grown tropical rice to increasing carbon dioxide and air temperature

    SciTech Connect

    Ziska, L.H.; Namuco, O.; Moya, T.; Quilang, J.

    1997-01-01

    Although the response of rice (Oryza sativa L.) to increasing atmospheric CO{sub 2} concentration and air temperature has been examined at the greenhouse or growth chamber level, no field studies have been conducted under the tropical, irrigated conditions where the bulk of the world`s rice is grown. At the International Rice Research Institute, rice (cv. IR 72) was grown from germination until maturity for the 1994 wet and 1995 dry seasons at three different CO{sub 2} concentrations (ambient, ambient + 200, and ambient + 300 {mu}L L{sup {minus}1}) resulted in a significant increase in total plant biomass (+31%, +40%) and crop yield (+15%, + 27%) compared with the ambient control. The increase in crop yield was associated with an increase in the number of panicles per square meter and a greater percentage of filled spikelets. Simultaneous increases in CO{sub 2} and air temperature did not alter the biomass at maturity (relative to elevated CO{sub 2} alone), but plant development was accelerated at the higher growth temperature regardless of CO{sub 2} concentration. Grain yield, however, became insensitive to CO{sub 2} concentration at the higher growth temperature. Increasing both CO{sub 2} and air temperature also reduced grain quality (e.g., protein content). The combination of CO{sub 2} and temperature effects suggests that, in warmer regions (i.e., >34{degrees}C) where rice is grown, quantitative and qualitative changes in rice supply are possible if both CO{sub 2} and air temperature continue to increase. 24 refs., 6 figs., 4 tabs.

  4. Response of carbon dioxide exchange to grazing intensity over typical steppes in a semi-arid area of Inner Mongolia

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Liu, Huizhi; Bernhofer, Christian

    2016-01-01

    The eddy covariance technique was used to measure the CO2 flux over four differently grazed Leymus chinensis steppe ecosystems (ungrazed since 1979 (UG79), winter grazed (WG), continuously grazed (CG), and heavily grazed (HG) sites) during four growing seasons (May to September) from 2005 to 2008, to investigate the response of the net ecosystem exchange (NEE) over grassland ecosystems to meteorological factors and grazing intensity. At UG79, the optimal air temperature for the half-hourly NEE occurred between 17 and 20 °C, which was relatively low for semi-arid grasslands. The saturated NEE (NEEsat) and temperature sensitivity coefficient (Q 10) of ecosystem respiration (RE) exhibited clear seasonal and interannual variations, which increased with canopy development and the soil water content (SWC, at 5 cm). The total NEE values for the growing seasons from 2005 to 2008 were -32.0, -41.5, -66.1, and -89.8 g C m-2, respectively. Both the amounts and distribution of precipitation during the growing season affected the NEE. The effects of grazing on the CO2 flux increased with the grazing intensity. During the peak growth stage, heavy grazing and winter grazing decreased NEEsat and gross primary production (45 % for HG and 34 % for WG) due to leaf area removal. Both RE and Q 10 were clearly reduced by heavy grazing. Heavy grazing changed the ecosystem from a CO2 sink into a CO2 source, and winter grazing reduced the total CO2 uptake by 79 %. In the early growing season, there was no difference in the NEE between CG and UG79. In addition to the grazing intensity, the effects of grazing on the CO2 flux also varied with the vegetation growth stages and SWC.

  5. Plant responses to short- and long-term exposures to high carbon dioxide levels in closed environments

    NASA Astrophysics Data System (ADS)

    Grodzinski, B.; Woodrow, L.; Leonardos, E. D.; Dixon, M.; Tsujita, M. J.

    1996-01-01

    When higher plants are exposed to elevated levels of CO_2 for both short- and long-term periods photosynthetic C-gain and photoassimilate export from leaves are generally increased. Water use efficiency is increased on a leaf area basis. During long-term exposures, photosynthesis rates on leaf and whole plant bases are altered in a species specific manner. The most common pattern in C_3 plants is an enhanced rate of whole plant photosynthesis in a well irradiated canopy. Nevertheless, in some herbaceous species prolonged exposure to high CO_2 results in remobilization of nitrogenous reserves (i.e., leaf protein degradation) and reduced rates of mature leaf photosynthesis when assayed at ambient CO_2 and O_2 levels. Both short- and long-term exposures to those CO_2 levels (i.e., 100 to 2,000 mul.l^-1) which modify photosynthesis and export, also modify both endogenous ethylene gas (C_2H_4) release, and substrate, 1-aminocyclopropane-1-carboxylic acid (ACC), saturated C_2H_4 release rates from irradiated leaves. Photosynthetically active canopy leaves contribute most of the C_2H_4 released from the canopy. Prolonged growth at high CO_2 results in a persistent increase in the rate of endogenous C_2H_4 release from leaves which can, only in part, be attributed to the increase of the endogenous pools of C_2H_4 pathway intermediates (e.g., methionine, M-ACC, and ACC). The capacity for increasing the rate of C_2H_4 release in response to short-term exposures to varying CO_2 levels does not decline after prolonged growth at high CO_2. When leaves, whole plants, and model canopies of tomato plants are exposed to exogenous C_2H_4 a reduction in the rate of photosynthesis can, in each case, be attributed to the classical effects of C_2H_4 on plant development and morphology. The effect of C_2H_4 on CO_2 gas exchange of plant canopies is shown to be dependent on the canopy leaf area index.

  6. Disintegration of Carbon Dioxide Molecules in a Microwave Plasma Torch.

    PubMed

    Kwak, Hyoung S; Uhm, Han S; Hong, Yong C; Choi, Eun H

    2015-12-17

    A pure carbon dioxide torch is generated by making use of 2.45 GHz microwave. Carbon dioxide gas becomes the working gas and produces a stable carbon dioxide torch. The torch volume is almost linearly proportional to the microwave power. Temperature of the torch flame is measured by making use of optical spectroscopy and thermocouple. Two distinctive regions are exhibited, a bright, whitish region of high-temperature zone and a bluish, dimmer region of relatively low-temperature zone. Study of carbon dioxide disintegration and gas temperature effects on the molecular fraction characteristics in the carbon dioxide plasma of a microwave plasma torch under atmospheric pressure is carried out. An analytical investigation of carbon dioxide disintegration indicates that substantial fraction of carbon dioxide molecules disintegrate and form other compounds in the torch. For example, the normalized particle densities at center of plasma are given by nCO2/nN = 6.12 × 10(-3), nCO/nN = 0.13, nC/nN = 0.24, nO/nN = 0.61, nC2/nN = 8.32 × 10(-7), nO2/nN = 5.39 × 10(-5), where nCO2, nCO, nC, nO, nC2, and nO2 are carbon dioxide, carbon monoxide, carbon and oxygen atom, carbon and oxygen molecule densities, respectively. nN is the neutral particle density. Emission profiles of the oxygen and carbon atom radicals and the carbon monoxide molecules confirm the theoretical predictions of carbon dioxide disintegration in the torch.

  7. Disintegration of Carbon Dioxide Molecules in a Microwave Plasma Torch

    PubMed Central

    Kwak, Hyoung S.; Uhm, Han S.; Hong, Yong C.; Choi, Eun H.

    2015-01-01

    A pure carbon dioxide torch is generated by making use of 2.45 GHz microwave. Carbon dioxide gas becomes the working gas and produces a stable carbon dioxide torch. The torch volume is almost linearly proportional to the microwave power. Temperature of the torch flame is measured by making use of optical spectroscopy and thermocouple. Two distinctive regions are exhibited, a bright, whitish region of high-temperature zone and a bluish, dimmer region of relatively low-temperature zone. Study of carbon dioxide disintegration and gas temperature effects on the molecular fraction characteristics in the carbon dioxide plasma of a microwave plasma torch under atmospheric pressure is carried out. An analytical investigation of carbon dioxide disintegration indicates that substantial fraction of carbon dioxide molecules disintegrate and form other compounds in the torch. For example, the normalized particle densities at center of plasma are given by nCO2/nN = 6.12 × 10−3, nCO/nN = 0.13, nC/nN = 0.24, nO/nN = 0.61, nC2/nN = 8.32 × 10−7, nO2/nN = 5.39 × 10−5, where nCO2, nCO, nC, nO, nC2, and nO2 are carbon dioxide, carbon monoxide, carbon and oxygen atom, carbon and oxygen molecule densities, respectively. nN is the neutral particle density. Emission profiles of the oxygen and carbon atom radicals and the carbon monoxide molecules confirm the theoretical predictions of carbon dioxide disintegration in the torch. PMID:26674957

  8. Disintegration of Carbon Dioxide Molecules in a Microwave Plasma Torch

    NASA Astrophysics Data System (ADS)

    Kwak, Hyoung S.; Uhm, Han S.; Hong, Yong C.; Choi, Eun H.

    2015-12-01

    A pure carbon dioxide torch is generated by making use of 2.45 GHz microwave. Carbon dioxide gas becomes the working gas and produces a stable carbon dioxide torch. The torch volume is almost linearly proportional to the microwave power. Temperature of the torch flame is measured by making use of optical spectroscopy and thermocouple. Two distinctive regions are exhibited, a bright, whitish region of high-temperature zone and a bluish, dimmer region of relatively low-temperature zone. Study of carbon dioxide disintegration and gas temperature effects on the molecular fraction characteristics in the carbon dioxide plasma of a microwave plasma torch under atmospheric pressure is carried out. An analytical investigation of carbon dioxide disintegration indicates that substantial fraction of carbon dioxide molecules disintegrate and form other compounds in the torch. For example, the normalized particle densities at center of plasma are given by nCO2/nN = 6.12 × 10-3, nCO/nN = 0.13, nC/nN = 0.24, nO/nN = 0.61, nC2/nN = 8.32 × 10-7, nO2/nN = 5.39 × 10-5, where nCO2, nCO, nC, nO, nC2, and nO2 are carbon dioxide, carbon monoxide, carbon and oxygen atom, carbon and oxygen molecule densities, respectively. nN is the neutral particle density. Emission profiles of the oxygen and carbon atom radicals and the carbon monoxide molecules confirm the theoretical predictions of carbon dioxide disintegration in the torch.

  9. Disintegration of Carbon Dioxide Molecules in a Microwave Plasma Torch.

    PubMed

    Kwak, Hyoung S; Uhm, Han S; Hong, Yong C; Choi, Eun H

    2015-01-01

    A pure carbon dioxide torch is generated by making use of 2.45 GHz microwave. Carbon dioxide gas becomes the working gas and produces a stable carbon dioxide torch. The torch volume is almost linearly proportional to the microwave power. Temperature of the torch flame is measured by making use of optical spectroscopy and thermocouple. Two distinctive regions are exhibited, a bright, whitish region of high-temperature zone and a bluish, dimmer region of relatively low-temperature zone. Study of carbon dioxide disintegration and gas temperature effects on the molecular fraction characteristics in the carbon dioxide plasma of a microwave plasma torch under atmospheric pressure is carried out. An analytical investigation of carbon dioxide disintegration indicates that substantial fraction of carbon dioxide molecules disintegrate and form other compounds in the torch. For example, the normalized particle densities at center of plasma are given by nCO2/nN = 6.12 × 10(-3), nCO/nN = 0.13, nC/nN = 0.24, nO/nN = 0.61, nC2/nN = 8.32 × 10(-7), nO2/nN = 5.39 × 10(-5), where nCO2, nCO, nC, nO, nC2, and nO2 are carbon dioxide, carbon monoxide, carbon and oxygen atom, carbon and oxygen molecule densities, respectively. nN is the neutral particle density. Emission profiles of the oxygen and carbon atom radicals and the carbon monoxide molecules confirm the theoretical predictions of carbon dioxide disintegration in the torch. PMID:26674957

  10. Hydropower’s Contribution to Carbon Dioxide Emission Reduction

    SciTech Connect

    Francfort, James E.

    1997-11-01

    The annual carbon dioxide emissions currently (1997 figures) avoided by the use of hydropower in electricity generation is 142 million metric tons, and it has a carbon tax value of $7.1 billion. Developing the identified additional hydropower capacity can yield an additional 34 million tons annually of avoided carbon dioxide emissions, with a value of $1.7 billion in carbon taxes. The total annual avoided emissions can exceed 176 million metric tons, with a value of $8.8 billion.

  11. Promising flame retardant textile in supercritical carbon dioxide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since carbon dioxide is non-toxic, non-flammable and cost-effective, supercritical carbon dioxide (scCO2) is widely used in textile dyeing applications. Due to its environmentally benign character, scCO2 is considered in green chemistry as a substitute for organic solvents in chemical reactions. O...

  12. Carbon Dioxide and Global Warming: A Failed Experiment

    ERIC Educational Resources Information Center

    Ribeiro, Carla

    2014-01-01

    Global warming is a current environmental issue that has been linked to an increase in anthropogenic carbon dioxide in the atmosphere. To raise awareness of the problem, various simple experiments have been proposed to demonstrate the effect of carbon dioxide on the planet's temperature. This article describes a similar experiment, which…

  13. Investigating Diffusion and Entropy with Carbon Dioxide-Filled Balloons

    ERIC Educational Resources Information Center

    Jadrich, James; Bruxvoort, Crystal

    2010-01-01

    Fill an ordinary latex balloon with helium gas and you know what to expect. Over the next day or two the volume will decrease noticeably as helium escapes from the balloon. So what happens when a latex balloon is filled with carbon dioxide gas? Surprisingly, carbon dioxide balloons deflate at rates as much as an order of magnitude faster than…

  14. 40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Carbon dioxide analyzer calibration... Regulations for 1977 and Later Model Year New Light-Duty Vehicles and New Light-Duty Trucks and New Otto-Cycle Complete Heavy-Duty Vehicles; Test Procedures § 86.124-78 Carbon dioxide analyzer calibration. Prior to...

  15. 40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 20 2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration... (CONTINUED) Emission Regulations for New Otto-Cycle and Diesel Heavy-Duty Engines; Gaseous and Particulate Exhaust Test Procedures § 86.1324-84 Carbon dioxide analyzer calibration. Prior to its introduction...

  16. Solid amine compounds as sorbents for carbon dioxide: A concept

    NASA Technical Reports Server (NTRS)

    Sutton, J. G.; Heimlich, P. F.; Tepper, E. H.

    1972-01-01

    Solid amine compounds were examined as possible absorbents for removal of carbon dioxide in life support systems of type which may be employed in high altitude aircraft, spacecraft, or submarines. Many solid amine compounds release absorbed carbon dioxide when heated in vacuum, therefore, when properly packaged spent amine compounds can be readily regenerated and put back into service.

  17. Plant responses to carbon dioxide

    SciTech Connect

    Murray, D.R.

    1995-05-01

    The average atmospheric concentration of CO{sub 2} will probably double before the end of next century. Many of the consequences for plant growth can and should be determined now. In this review the effects of [CO{sub 2}] on a variety of plant processes are summarized: stomatal opening and closing; stomatal density; respiration; root morphogenesis; and flowering. The effects of growth under elevated [CO{sub 2}] on crop yield and seed composition are also discussed. Adverse effects on the composition of C{sub 3} cereal grains are clearly indicated. 91 refs., 2 tabs.

  18. Carbon dioxide absorbent and method of using the same

    DOEpatents

    Perry, Robert James; Lewis, Larry Neil; O'Brien, Michael Joseph; Soloveichik, Grigorii Lev; Kniajanski, Sergei; Lam, Tunchiao Hubert; Lee, Julia Lam; Rubinsztajn, Malgorzata Iwona

    2011-10-04

    In accordance with one aspect, the present invention provides an amino-siloxane composition comprising at least one of structures I, II, III, IV or V said compositions being useful for the capture of carbon dioxide from gas streams such as power plant flue gases. In addition, the present invention provides methods of preparing the amino-siloxane compositions are provided. Also provided are methods for reducing the amount of carbon dioxide in a process stream employing the amino-siloxane compositions of the invention as species which react with carbon dioxide to form an adduct with carbon dioxide. The reaction of the amino-siloxane compositions provided by the present invention with carbon dioxide is reversible and thus, the method provides for multicycle use of said compositions.

  19. Carbon Dioxide Detection and Indoor Air Quality Control.

    PubMed

    Bonino, Steve

    2016-04-01

    When building ventilation is reduced, energy is saved because it is not necessary to heat or cool as much outside air. Reduced ventilation can result in higher levels of carbon dioxide, which may cause building occupants to experience symptoms. Heating or cooling for ventilation air can be enhanced by a DCV system, which can save energy while providing a comfortable environment. Carbon dioxide concentrations within a building are often used to indicate whether adequate fresh air is being supplied to the building. These DCV systems use carbon dioxide sensors in each space or in the return air and adjust the ventilation based on carbon dioxide concentration; the higher the concentration, the more people occupy the space relative to the ventilation rate. With a carbon dioxide sensor DCV system, the fresh air ventilation rate varies based on the number ofpeople in the space, saving energy while maintaining a safe and comfortable environment.

  20. Carbon dioxide stripping in aquaculture. part 1: terminology and reporting

    USGS Publications Warehouse

    Colt, John; Watten, Barnaby; Pfeiffer, Tim

    2012-01-01

    The removal of carbon dioxide gas in aquacultural systems is much more complex than for oxygen or nitrogen gas because of liquid reactions of carbon dioxide and their kinetics. Almost all published carbon dioxide removal information for aquaculture is based on the apparent removal value after the CO2(aq) + HOH ⇔ H2CO3 reaction has reached equilibrium. The true carbon dioxide removal is larger than the apparent value, especially for high alkalinities and seawater. For low alkalinity freshwaters (<2000 μeq/kg), the difference between the true and apparent removal is small and can be ignored for many applications. Analytical and reporting standards are recommended to improve our understanding of carbon dioxide removal.

  1. Do fossil plants signal palaeoatmospheric carbon dioxide concentration in the geological past?

    PubMed Central

    McElwain, J. C.

    1998-01-01

    Fossil, subfossil, and herbarium leaves have been shown to provide a morphological signal of the atmospheric carbon dioxide environment in which they developed by means of their stomatal density and index. An inverse relationship between stomatal density/index and atmospheric carbon dioxide concentration has been documented for all the studies to date concerning fossil and subfossil material. Furthermore, this relationship has been demonstrated experimentally by growing plants under elevated and reducedcarbon dioxide concentrations. To date, the mechanism that controls the stomatal density response to atmospheric carbon dioxide concentration remains unknown. However, stomatal parameters of fossil plants have been successfully used as a proxy indicator of palaeo-carbon dioxide levels. This paper presents new estimates of palaeo-atmospheric carbon dioxide concentrations for the Middle Eocene (Lutetian), based on the stomatal ratios of fossil Lauraceae species from Bournemouth in England. Estimates of atmospheric carbon dioxide concentrations derived from stomatal data from plants of the Early Devonian, Late Carboniferous, Early Permian and Middle Jurassic ages are reviewed in the light of new data. Semi-quantitative palaeo-carbon dioxide estimates based on the stomatal ratio (a ratio of the stomatal index of a fossil plant to that of a selected nearest living equivalent) have in the past relied on the use of a Carboniferous standard. The application of a new standard based on the present-day carbon dioxide level is reported here for comparison. The resultant ranges of palaeo-carbon dioxide estimates made from standardized fossil stomatal ratio data are in good agreement with both carbon isotopic data from terrestrial and marine sources and long-term carbon cycle modelling estimates for all the time periods studied. These data indicate elevated atmospheric carbon dioxide concentrations during the Early Devonian, Middle Jurassic and Middle Eocene, and reduced

  2. Photobiological hydrogen production and carbon dioxide sequestration

    NASA Astrophysics Data System (ADS)

    Berberoglu, Halil

    Photobiological hydrogen production is an alternative to thermochemical and electrolytic technologies with the advantage of carbon dioxide sequestration. However, it suffers from low solar to hydrogen energy conversion efficiency due to limited light transfer, mass transfer, and nutrient medium composition. The present study aims at addressing these limitations and can be divided in three parts: (1) experimental measurements of the radiation characteristics of hydrogen producing and carbon dioxide consuming microorganisms, (2) solar radiation transfer modeling and simulation in photobioreactors, and (3) parametric experiments of photobiological hydrogen production and carbon dioxide sequestration. First, solar radiation transfer in photobioreactors containing microorganisms and bubbles was modeled using the radiative transport equation (RTE) and solved using the modified method of characteristics. The study concluded that Beer-Lambert's law gives inaccurate results and anisotropic scattering must be accounted for to predict the local irradiance inside a photobioreactor. The need for accurate measurement of the complete set of radiation characteristics of microorganisms was established. Then, experimental setup and analysis methods for measuring the complete set of radiation characteristics of microorganisms have been developed and successfully validated experimentally. A database of the radiation characteristics of representative microorganisms have been created including the cyanobacteria Anabaena variabilis, the purple non-sulfur bacteria Rhodobacter sphaeroides and the green algae Chlamydomonas reinhardtii along with its three genetically engineered strains. This enabled, for the first time, quantitative assessment of the effect of genetic engineering on the radiation characteristics of microorganisms. In addition, a parametric experimental study has been performed to model the growth, CO2 consumption, and H 2 production of Anabaena variabilis as functions of

  3. Growth, Yield, and Nutritional Responses of Chamber-Grown Sweet Potato to Elevated Carbon Dioxide Levels Expected Across the Next 200 Years

    NASA Astrophysics Data System (ADS)

    Czeck, B. C.; Jahren, H.; Deenik, J. L.; Crow, S. E.; Schubert, B.; Stewart, M.

    2012-12-01

    Understanding the effects of increasing atmospheric carbon dioxide (CO2) concentrations on crops will be critical to assuring that sufficient food is available to the world's growing population. Previous work has shown that slightly elevated CO2 levels (CO2 = 550-700 ppm) increase the economic yield of most crops by ~33%, on average. The majority of these studies have focused on rice, wheat, and soybean; however, climate change is expected to have greatest impact on regions of the world that rely heavily on root crops, such as sweet potato (Ipomoea batatas). Sweet potato is cultivated in more than 100 developing countries; it is ranked seventh in world crop statistics and can produce more edible energy per hectare and per day than wheat, rice or cassava. In order to quantify the effect that rising CO2 levels will have on sweet potato, we grew a total of 64 sweet potato plants to maturity in large controlled growth chambers at ambient, 760, 1,140, and 1,520-ppm CO2 levels. At planting, initial measurements (of mass, length, and number of nodes) for each plant were recorded. Throughout the duration of the experiment (90 days) measurements (of stem length, and number of leaves) were recorded every 7 to 14 days. To ensure optimum growing conditions moisture content was monitored using soil tensiometers; temperature, relative humidity and CO2 concentrations were recorded every ten minutes. Half the plants were supplemented with an inorganic fertilizer and the other half with an organic fertilizer to test the effect of nutrient availability on biomass production under elevated CO2 levels. After 3 months of growth, we measured fresh and dry biomass of all above- and below-ground tissues. Results showed a substantial increase in both above- and below-ground biomass at elevated levels of CO2. For the organic treatment, a 43% increase in aboveground dry biomass at the highest CO2 concentration (1520ppm) was found; the inorganic treatment showed a 31% increase. The

  4. Atmospheric carbon dioxide, the southern oscillation, and the weak 1975 El Nino

    SciTech Connect

    Bacostow, R.B.; Adams, J.A.; Keeling, C.D.; Moss, D.J.; Whorf, T.P.; Wong, C.S.

    1980-10-03

    The observed rate of change of the atmospheric carbon dioxide concentration at the South Pole, Fanning Island, Hawaii, and ocean weather station P correlates with an index of the southern oscillation and with El Nino occurrences. There are changes at all four stations that seem to be in response to the weak 1975 El Nino. Thus, even poorly developed El Nino events may affect the atmospheric carbon dioxide concentration.

  5. Tracing changes in ecosystem function under elevated carbon dioxide conditions.

    SciTech Connect

    Pataki, D. E.; Ellsworth, D. S.; Evans, R. D.; Gonzalez-Meler, M.; King, J.; Leavitt, S. W.; Lin, G.; Matamala, R.; Pendall, E.; Siegwolf, R.; Van Kessel, C.; Ehleringer, J. F.; Environmental Research; Univ. of Utah; Univ. of Michigan; Washington State Univ.; Univ. of Illinois at Chicago; Michigan Technological Univ.; Univ. of Arizona; Columbia Univ.; Univ. of Wyoming; Paul Scherrer Inst.; Univ. of California, Davis

    2003-09-01

    Responses of ecosystems to elevated levels of atmospheric carbon dioxide (CO{sub 2}) remain a critical uncertainty in global change research. Two key unknown factors are the fate of carbon newly incorporated by photosynthesis into various pools within the ecosystem and the extent to which elevated CO{sub 2} is transferred to and sequestered in pools with long turnover times. The CO{sub 2} used for enrichment in many experiments incorporates a dual isotopic tracer, in the sense that ratios of both the stable carbon-13 ({sup 13}C) and the radioactive carbon-14 ({sup 14}C) isotopes with respect to carbon-12 are different from the corresponding ratios in atmospheric CO{sub 2}. Here we review techniques for using {sup 13}C and {sup 14}C abundances to follow the fate of newly fixed carbon and to further our understanding of the turnover times of ecosystem carbon pools. We also discuss the application of nitrogen, oxygen, and hydrogen isotope analyses for tracing changes in the linkages between carbon, nitrogen, and water cycles under conditions of elevated CO{sub 2}.

  6. Global carbon dioxide emissions from inland waters

    USGS Publications Warehouse

    Raymond, Peter A.; Hartmann, Jens; Lauerwald, Ronny; Sobek, Sebastian; McDonald, Cory P.; Hoover, Mark; Butman, David; Striegl, Rob; Mayorga, Emilio; Humborg, Christoph; Kortelainen, Pirkko; Durr, Hans H.; Meybeck, Michel; Ciais, Philippe; Guth, Peter

    2013-01-01

    Carbon dioxide (CO2) transfer from inland waters to the atmosphere, known as CO2 evasion, is a component of the global carbon cycle. Global estimates of CO2 evasion have been hampered, however, by the lack of a framework for estimating the inland water surface area and gas transfer velocity and by the absence of a global CO2 database. Here we report regional variations in global inland water surface area, dissolved CO2 and gas transfer velocity. We obtain global CO2 evasion rates of 1.8   petagrams of carbon (Pg C) per year from streams and rivers and 0.32  Pg C yr−1 from lakes and reservoirs, where the upper and lower limits are respectively the 5th and 95th confidence interval percentiles. The resulting global evasion rate of 2.1 Pg C yr−1 is higher than previous estimates owing to a larger stream and river evasion rate. Our analysis predicts global hotspots in stream and river evasion, with about 70 per cent of the flux occurring over just 20 per cent of the land surface. The source of inland water CO2 is still not known with certainty and new studies are needed to research the mechanisms controlling CO2 evasion globally.

  7. Carbon dioxide emission from bamboo culms.

    PubMed

    Zachariah, E J; Sabulal, B; Nair, D N K; Johnson, A J; Kumar, C S P

    2016-05-01

    Bamboos are one of the fastest growing plants on Earth, and are widely considered to have high ability to capture and sequester atmospheric carbon, and consequently to mitigate climate change. We tested this hypothesis by measuring carbon dioxide (CO2 ) emissions from bamboo culms and comparing them with their biomass sequestration potential. We analysed diurnal effluxes from Bambusa vulgaris culm surface and gas mixtures inside hollow sections of various bamboos using gas chromatography. Corresponding variations in gas pressure inside the bamboo section and culm surface temperature were measured. SEM micrographs of rhizome and bud portions of bamboo culms were also recorded. We found very high CO2 effluxes from culm surface, nodes and buds of bamboos. Positive gas pressure and very high concentrations of CO2 were observed inside hollow sections of bamboos. The CO2 effluxes observed from bamboos were very high compared to their carbon sequestration potential. Our measurements suggest that bamboos are net emitters of CO2 during their lifespan. PMID:26802362

  8. Carbon dioxide: Global warning for nephrologists

    PubMed Central

    Marano, Marco; D’Amato, Anna; Cantone, Alessandra

    2016-01-01

    The large prevalence of respiratory acid-base disorders overlapping metabolic acidosis in hemodialysis population should prompt nephrologists to deal with the partial pressure of carbon dioxide (pCO2) complying with the reduced bicarbonate concentration. What the most suitable formula to compute pCO2 is reviewed. Then, the neglected issue of CO2 content in the dialysis fluid is under the spotlight. In fact, a considerable amount of CO2 comes to patients’ bloodstream every hemodialysis treatment and “acidosis by dialysate” may occur if lungs do not properly clear away this burden of CO2. Moreover, vascular access recirculation may be easy diagnosed by detecting CO2 in the arterial line of extracorporeal circuit if CO2-enriched blood from the filter reenters arterial needle. PMID:27648406

  9. Carbon dioxide: Global warning for nephrologists.

    PubMed

    Marano, Marco; D'Amato, Anna; Cantone, Alessandra

    2016-09-01

    The large prevalence of respiratory acid-base disorders overlapping metabolic acidosis in hemodialysis population should prompt nephrologists to deal with the partial pressure of carbon dioxide (pCO2) complying with the reduced bicarbonate concentration. What the most suitable formula to compute pCO2 is reviewed. Then, the neglected issue of CO2 content in the dialysis fluid is under the spotlight. In fact, a considerable amount of CO2 comes to patients' bloodstream every hemodialysis treatment and "acidosis by dialysate" may occur if lungs do not properly clear away this burden of CO2. Moreover, vascular access recirculation may be easy diagnosed by detecting CO2 in the arterial line of extracorporeal circuit if CO2-enriched blood from the filter reenters arterial needle. PMID:27648406

  10. Thermodynamical effects during carbon dioxide release

    NASA Astrophysics Data System (ADS)

    Singh, A. K.; Böttcher, N.; Görke, U.-J.; Kolditz, O.

    2012-04-01

    Pruess [1] investigated the risk of carbon dioxide leakage from shallow storage sites by modeling scenarios. Such a fluid release is associated with mechanical work performed by formation fluid against expansion without taking heat from ambient environment. Understanding of heat related to mechanical work is essential to predict the temperature at the leak. According to the first law of thermodynamics, internal energy of working fluid decreases with an amount which is equivalent to this work hence, working fluid lost its own heat. Such kind of heat loss depends strongly on whether the expansion process is adiabatic or isothermal. Isothermal expansion allows the working fluid to interact thermally with the solid matrix. Adiabatic expansion is an isenthalpic process that takes heat from the working fluid and the ambient environment remains unchanged. This work is part of the CLEAN research project [6]. In this study, thermodynamic effects of mechanical work during eventual carbon dioxide leakage are investigated numerically. In particular, we are interested to detect the temperature at leakage scenarios and its deviation with different thermodynamic processes. Finite element simulation is conducted with a two-dimensional rectangular geometry representing a shallow storage site which bottom was located at -300m below the land surface. A fully saturated porous medium is assumed where the pore space is filled completely with carbon dioxide. Carbon dioxide accumulated in the secondary trap at 30 Bar and 24 °C is allowed to leak from top right point of rectangle with atmospheric pressure. With (i) adiabatic and (ii) isothermal compressibility factors, temperature around leakage area has been calculated which show a significant difference. With some simplification, this study detects leak temperature which is very close with [1]. Temporal evaluation at the leaky area shows that the working fluid temperature can be reduced to -20 °C when the leakage scenario is performed

  11. Carbon dioxide removal with inorganic membranes

    SciTech Connect

    Judkins, R.R.; Fain, D.E.

    1993-12-31

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

  12. Carbon dioxide: Global warning for nephrologists

    PubMed Central

    Marano, Marco; D’Amato, Anna; Cantone, Alessandra

    2016-01-01

    The large prevalence of respiratory acid-base disorders overlapping metabolic acidosis in hemodialysis population should prompt nephrologists to deal with the partial pressure of carbon dioxide (pCO2) complying with the reduced bicarbonate concentration. What the most suitable formula to compute pCO2 is reviewed. Then, the neglected issue of CO2 content in the dialysis fluid is under the spotlight. In fact, a considerable amount of CO2 comes to patients’ bloodstream every hemodialysis treatment and “acidosis by dialysate” may occur if lungs do not properly clear away this burden of CO2. Moreover, vascular access recirculation may be easy diagnosed by detecting CO2 in the arterial line of extracorporeal circuit if CO2-enriched blood from the filter reenters arterial needle.

  13. New Trends In Carbon Dioxide Laser Microsurgery

    NASA Astrophysics Data System (ADS)

    Smith, M. R.; Miller, James B.

    1981-05-01

    The carbon dioxide laser has been used for cutting and cauterizing tissue in a variety of surgical procedures by means of a dry-field air/tissue interface approach. Recently, a new wet-field CO2 laser technique has been developed and is being used successfully in humans to seal intraocular fibrovascular fronds and retinal tears at the time of vitrectomy, to close rubeotic vessels in the iris, and to excise fibrovascular fronds and epiretinal membranes in cases of severe diabetic retinopathy. Specialized wet-field CO2 photosurgical probes for use in gynecologic microsurgery have been developed and are being studied experimentally. Other potential applications include otolaryngologic micro-surgery, neurosurgery, and gastrointestinal and urologic wet-field surgery.

  14. Biochemical Capture and Removal of Carbon Dioxide

    NASA Technical Reports Server (NTRS)

    Trachtenberg, Michael C.

    1998-01-01

    We devised an enzyme-based facilitated transport membrane bioreactor system to selectively remove carbon dioxide (CO2) from the space station environment. We developed and expressed site-directed enzyme mutants for CO2 capture. Enzyme kinetics showed the mutants to be almost identical to the wild type save at higher pH. Both native enzyme and mutant enzymes were immobilized to different supports including nylons, glasses, sepharose, methacrylate, titanium and nickel. Mutant enzyme could be attached and removed from metal ligand supports and the supports reused at least five times. Membrane systems were constructed to test CO2 selectivity. These included proteic membranes, thin liquid films and enzyme-immobilized teflon membranes. Selectivity ratios of more than 200:1 were obtained for CO2 versus oxygen with CO2 at 0.1%. The data indicate that a membrane based bioreactor can be constructed which could bring CO2 levels close to Earth.

  15. Layered solid sorbents for carbon dioxide capture

    SciTech Connect

    Li, Bingyun; Jiang, Bingbing; Gray, McMahan L; Fauth, Daniel J; Pennline, Henry W; Richards, George A

    2014-11-18

    A solid sorbent for the capture and the transport of carbon dioxide gas is provided having at least one first layer of a positively charged material that is polyethylenimine or poly(allylamine hydrochloride), that captures at least a portion of the gas, and at least one second layer of a negatively charged material that is polystyrenesulfonate or poly(acryclic acid), that transports the gas, wherein the second layer of material is in juxtaposition to, attached to, or crosslinked with the first layer for forming at least one bilayer, and a solid substrate support having a porous surface, wherein one or more of the bilayers is/are deposited on the surface of and/or within the solid substrate. A method of preparing and using the solid sorbent is provided.

  16. Pulsed-discharge carbon dioxide lasers

    NASA Technical Reports Server (NTRS)

    Willetts, David V.

    1990-01-01

    The purpose is to attempt a general introduction to pulsed carbon dioxide lasers of the kind used or proposed for laser radar applications. Laser physics is an excellent example of a cross-disciplinary topic, and the molecular spectroscopy, energy transfer, and plasma kinetics of the devices are explored. The concept of stimulated emission and population inversions is introduced, leading on to the molecular spectroscopy of the CO2 molecule. This is followed by a consideration of electron-impact pumping, and the pertinent energy transfer and relaxation processes which go on. Since the devices are plasma pumped, it is necessary to introduce a complex subject, but this is restricted to appropriate physics of glow discharges. Examples of representative devices are shown. The implications of the foregoing to plasma chemistry and gas life are discussed.

  17. Carbon dioxide: Global warning for nephrologists.

    PubMed

    Marano, Marco; D'Amato, Anna; Cantone, Alessandra

    2016-09-01

    The large prevalence of respiratory acid-base disorders overlapping metabolic acidosis in hemodialysis population should prompt nephrologists to deal with the partial pressure of carbon dioxide (pCO2) complying with the reduced bicarbonate concentration. What the most suitable formula to compute pCO2 is reviewed. Then, the neglected issue of CO2 content in the dialysis fluid is under the spotlight. In fact, a considerable amount of CO2 comes to patients' bloodstream every hemodialysis treatment and "acidosis by dialysate" may occur if lungs do not properly clear away this burden of CO2. Moreover, vascular access recirculation may be easy diagnosed by detecting CO2 in the arterial line of extracorporeal circuit if CO2-enriched blood from the filter reenters arterial needle.

  18. Dissociation-excitation reactions of argon metastables with carbon dioxide.

    NASA Technical Reports Server (NTRS)

    Starr, W. L.

    1971-01-01

    Results of a study showing that a metastable argon-carbon dioxide reaction results in dissociation of carbon dioxide and electronic excitation of one of the products, carbon monoxide or oxygen. A flow system using a 2450-MHz discharge was used to produce metastable argon atoms. Metastable argon in the afterglow was confirmed by adding nitrogen to the afterglow. Without addition of carbon dioxide no argon line emission, or any other emission, is observed from the reaction zone. Absence of argon line emission produced by recombination indicates the absence of charged species.

  19. Six-fold coordinated carbon dioxide VI.

    PubMed

    Iota, Valentin; Yoo, Choong-Shik; Klepeis, Jae-Hyun; Jenei, Zsolt; Evans, William; Cynn, Hyunchae

    2007-01-01

    Under standard conditions, carbon dioxide (CO2) is a simple molecular gas and an important atmospheric constituent, whereas silicon dioxide (SiO2) is a covalent solid, and one of the fundamental minerals of the planet. The remarkable dissimilarity between these two group IV oxides is diminished at higher pressures and temperatures as CO2 transforms to a series of solid phases, from simple molecular to a fully covalent extended-solid V, structurally analogous to SiO2 tridymite. Here, we present the discovery of an extended-solid phase of CO2: a six-fold coordinated stishovite-like phase VI, obtained by isothermal compression of associated CO2-II (refs 1,2) above 50 GPa at 530-650 K. Together with the previously reported CO2-V (refs 3-5) and a-carbonia, this extended phase indicates a fundamental similarity between CO2 (a prototypical molecular solid) and SiO2 (one of Earth's fundamental building blocks). We present a phase diagram with a limited stability domain for molecular CO2-I, and suggest that the conversion to extended-network solids above 40-50 GPa occurs via intermediate phases II (refs 1,2), III (refs 7,8) and IV (refs 9,10). The crystal structure of phase VI suggests strong disorder along the c axis in stishovite-like P42/mnm, with carbon atoms manifesting an average six-fold coordination within the framework of sp3 hybridization. PMID:17160005

  20. Coiled tubing drilling with supercritical carbon dioxide

    DOEpatents

    Kolle , Jack J.

    2002-01-01

    A method for increasing the efficiency of drilling operations by using a drilling fluid material that exists as supercritical fluid or a dense gas at temperature and pressure conditions existing at a drill site. The material can be used to reduce mechanical drilling forces, to remove cuttings, or to jet erode a substrate. In one embodiment, carbon dioxide (CO.sub.2) is used as the material for drilling within wells in the earth, where the normal temperature and pressure conditions cause CO.sub.2 to exist as a supercritical fluid. Supercritical carbon dioxide (SC--CO.sub.2) is preferably used with coiled tube (CT) drilling equipment. The very low viscosity SC--CO.sub.2 provides efficient cooling of the drill head, and efficient cuttings removal. Further, the diffusivity of SC--CO.sub.2 within the pores of petroleum formations is significantly higher than that of water, making jet erosion using SC--CO.sub.2 much more effective than water jet erosion. SC--CO.sub.2 jets can be used to assist mechanical drilling, for erosion drilling, or for scale removal. A choke manifold at the well head or mud cap drilling equipment can be used to control the pressure within the borehole, to ensure that the temperature and pressure conditions necessary for CO.sub.2 to exist as either a supercritical fluid or a dense gas occur at the drill site. Spent CO.sub.2 can be vented to the atmosphere, collected for reuse, or directed into the formation to aid in the recovery of petroleum.

  1. Global carbon dioxide emission to the atmosphere by volcanoes

    SciTech Connect

    Williams, S.N.; Schaefer, S.J. ); Calvache V., M.L. Observatorio Vulcanologico de Colombia, Pasto ); Lopez, D. )

    1992-04-01

    Global emission of carbon dioxide by subaerial volcanoes is calculated, using CO{sub 2}/SO{sub 2} from volcanic gas analyses and SO{sub 2} flux, to be 34 {plus minus} 24 {times} 10{sup 12} g CO{sub 2}/yr from passive degassing and 31 {plus minus} 22 {times} 10{sup 12} g CO{sub 2}/yr from eruptions. Volcanic CO{sub 2} presently represents only 0.22% of anthropogenic emissions but may have contributed to significant greenhouse' effects at times in Earth history. Models of climate response to CO{sub 2} increases may be tested against geological data.

  2. National assessment of geologic carbon dioxide storage resources: methodology implementation

    USGS Publications Warehouse

    Blondes, Madalyn S.; Brennan, Sean T.; Merrill, Matthew D.; Buursink, Marc L.; Warwick, Peter D.; Cahan, Steven M.; Corum, Margo D.; Cook, Troy A.; Craddock, William H.; DeVera, Christina A.; Drake II, Ronald M.; Drew, Lawrence J.; Freeman, P.A.; Lohr, Celeste D.; Olea, Ricardo A.; Roberts-Ashby, Tina L.; Slucher, Ernie R.; Varela, Brian A.

    2013-01-01

    In response to the 2007 Energy Independence and Security Act, the U.S. Geological Survey (USGS) conducted a national assessment of potential geologic storage resources for carbon dioxide (CO2). Storage of CO2 in subsurface saline formations is one important method to reduce greenhouse gas emissions and curb global climate change. This report provides updates and implementation details of the assessment methodology of Brennan and others (2010, http://pubs.usgs.gov/of/2010/1127/) and describes the probabilistic model used to calculate potential storage resources in subsurface saline formations.

  3. Intraosseous Venography with Carbon Dioxide in Percutaneous Vertebroplasty: Carbon Dioxide Retention in Renal Veins

    SciTech Connect

    Komemushi, Atsushi Tanigawa, Noboru; Kariya, Shuji; Kojima, Hiroyuki; Shomura, Yuzo; Tokuda, Takanori; Nomura, Motoo; Terada, Jiro; Kamata, Minoru; Sawada, Satoshi

    2008-11-15

    The objective of the present study was to determine the frequency of gas retention in the renal vein following carbon dioxide intraosseous venography in the prone position and, while citing references, to examine its onset mechanisms. All percutaneous vertebroplasties performed at our hospital from January to December 2005 were registered and retrospectively analyzed. Of 43 registered procedures treating 79 vertebrae, 28 procedures treating 54 vertebrae were analyzed. Vertebral intraosseous venography was performed using carbon dioxide as a contrast agent in all percutaneous vertebroplasty procedures. In preoperative and postoperative vertebral CT, gas retention in the renal vein and other areas was assessed. Preoperative CT did not show gas retention (0/28 procedures; 0%). Postoperative CT confirmed gas retention in the renal vein in 10 of the 28 procedures (35.7%). Gas retention was seen in the right renal vein in 8 procedures (28.6%), in the left renal vein in 5 procedures (17.9%), in the left and right renal veins in 3 procedures (10.7%), in vertebrae in 22 procedures (78.6%), in the soft tissue around vertebrae in 14 procedures (50.0%), in the spinal canal in 12 procedures (42.9%), and in the subcutaneous tissue in 5 procedures (17.9%). In conclusion, in our study, carbon dioxide gas injected into the vertebra frequently reached and remained in the renal vein.

  4. Fluxes of carbon dioxide at Thetford Forest

    NASA Astrophysics Data System (ADS)

    Jarvis, P. G.; Stewart, J. B.; Meir, P.

    2007-01-01

    The Thetford Project (1968-1976) was a keystone project for the newly established Institute of Hydrology. Its primary objective was to elucidate the processes underlying evaporation of transpired water and intercepted rainfall from plantation forest, so as to explain hydrological observations that more water was apparently returned to the atmosphere from plantations than from grassland and heathland. The primary approach was to determine the fluxes of water vapour from a stand of Scots pine, situated within a larger area of plantations of Scots and Corsican pine, in Thetford Forest, East Anglia, UK, using the Bowen ratio approach. In 1976, advantage was taken of the methodology developed to add measurement of profiles of carbon dioxide concentration so as to enable the fluxes of CO2 also to be calculated. A team from Aberdeen and Edinburgh Universities collected 914 hours of 8-point CO2 concentration profiles, largely between dawn and dusk, on days from March to October, and the data from an "elite" data set of 710 hours have been analysed. In conditions of moderate temperature (<25°C) and specific humidity deficit (<15 g kg-1 with high solar irradiance (>500 W m-2), CO2 uptake reached relatively high rates for pine of up to 20 µmol m-2 s-1 in the middle of the day. This rate of CO2 uptake is higher than has been recently found for four Scots pine forests in continental Europe during July 1997. However, the year of 1976 was exceptionally hot and dry, with air temperatures reaching 30°C and the water deficit in the top 3 m of soil at the site of 152 mm by August. Air temperatures of over 25°C led to large specific humidity deficits, approaching 20 g kg-1, and associated severe reductions in CO2 uptake, as well as in evaporation. However, when specific humidity deficits dropped below c. 15 g kg-1 on succeeding days, generally as a result of lower air temperatures rather than lower solar irradiance, there was rapid recovery in both uptake and evaporation, thus

  5. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    SciTech Connect

    David A. Green; Brian S. Turk; Jeffrey W. Portzer; Thomas Nelson; Raghubir P. Gupta

    2005-01-01

    This report describes research conducted between October 1, 2004 and December 31, 2004 on the use of dry regenerable sorbents for removal of carbon dioxide from flue gas. Two supported sorbents were tested in a bench scale fluidized bed reactor system. The sorbents were prepared by impregnation of sodium carbonate on to an inert support at a commercial catalyst manufacturing facility. One sorbent, tested through five cycles of carbon dioxide sorption in an atmosphere of 3% water vapor and 0.8 to 3% carbon dioxide showed consistent reactivity with sodium carbonate utilization of 7 to 14%. A second, similarly prepared material, showed comparable reactivity in one cycle of testing. Batches of 5 other materials were prepared in laboratory scale quantities (primarily by spray drying). These materials generally have significantly greater surface areas than calcined sodium bicarbonate. Small scale testing showed no significant adsorption of mercury on representative carbon dioxide sorbent materials under expected flue gas conditions.

  6. Estimated Carbon Dioxide Emissions in 2008: United States

    SciTech Connect

    Smith, C A; Simon, A J; Belles, R D

    2011-04-01

    Flow charts depicting carbon dioxide emissions in the United States have been constructed from publicly available data and estimates of state-level energy use patterns. Approximately 5,800 million metric tons of carbon dioxide were emitted throughout the United States for use in power production, residential, commercial, industrial, and transportation applications in 2008. Carbon dioxide is emitted from the use of three major energy resources: natural gas, coal, and petroleum. The flow patterns are represented in a compact 'visual atlas' of 52 state-level (all 50 states, the District of Columbia, and one national) carbon dioxide flow charts representing a comprehensive systems view of national CO{sub 2} emissions. Lawrence Livermore National Lab (LLNL) has published flow charts (also referred to as 'Sankey Diagrams') of important national commodities since the early 1970s. The most widely recognized of these charts is the U.S. energy flow chart (http://flowcharts.llnl.gov). LLNL has also published charts depicting carbon (or carbon dioxide potential) flow and water flow at the national level as well as energy, carbon, and water flows at the international, state, municipal, and organizational (i.e. United States Air Force) level. Flow charts are valuable as single-page references that contain quantitative data about resource, commodity, and byproduct flows in a graphical form that also convey structural information about the system that manages those flows. Data on carbon dioxide emissions from the energy sector are reported on a national level. Because carbon dioxide emissions are not reported for individual states, the carbon dioxide emissions are estimated using published energy use information. Data on energy use is compiled by the U.S. Department of Energy's Energy Information Administration (U.S. EIA) in the State Energy Data System (SEDS). SEDS is updated annually and reports data from 2 years prior to the year of the update. SEDS contains data on primary

  7. Sequestration of carbon dioxide (CO2) using red mud.

    PubMed

    Yadav, Vishwajeet S; Prasad, Murari; Khan, Jeeshan; Amritphale, S S; Singh, M; Raju, C B

    2010-04-15

    Red mud, an aluminium industry hazardous waste, has been reported to be an inexpensive and effective adsorbent. In the present work applicability of red mud for the sequestration of green house gases with reference to carbon dioxide has been studied. Red mud sample was separated into three different size fractions (RM I, RM II, RM III) of varying densities (1.5-2.2 g cm(-3)). Carbonation of each fraction of red mud was carried out separately at room temperature using a stainless steel reaction chamber at a fixed pressure of 3.5 bar. Effects of reaction time (0.5-12 h) and liquid to solid ratio (0.2-0.6) were studied for carbonation of red mud. Different instrumental techniques such as X-ray diffraction, FTIR and scanning electron microscope (SEM) were used to ascertain the different mineral phases before and after carbonation of each fraction of red mud. Characterization studies revealed the presence of boehmite, cancrinite, chantalite, hematite, gibbsite, anatase, rutile and quartz. Calcium bearing mineral phases (cancrinite and chantalite) were found responsible for carbonation of red mud. Maximum carbonation was observed for the fraction RM II having higher concentration of cancrinite. The carbonation capacity is evaluated to be 5.3 g of CO(2)/100 g of RM II.

  8. Carbon Dioxide Information Analysis Center: FY 1991 activities

    SciTech Connect

    Cushman, R.M.; Stoss, F.W.

    1992-06-01

    During the course of a fiscal year, Oak Ridge National Laboratory`s Carbon Dioxide Information Analysis Center (CDIAC) distributes thousands of specially publications-numeric data packages (NDPs), computer model packages (CMPs), technical reports, public communication publications, newsletters, article reprints, and reference books-in response to requests for information related to global environmental issues, primarily those pertaining to climate change. CDIAC`s staff also provides technical responses to specific inquiries related to carbon dioxide (CO{sub 2}), other trace gases, and climate. Hundreds of referrals to other researchers, policy analysts, information specialists, or organizations are also facilitated by CDIAC`s staff. This report provides an account of the activities accomplished by CDIAC during the period October 1, 1990 to September 30, 1991. An organizational overview of CDIAC and its staff is supplemented by a detailed description of inquiries received and CDIAC`s response to those inquiries. An analysis and description of the preparation and distribution of numeric data packages, computer model packages, technical reports, newsletters, factsheets, specially publications, and reprints is provided. Comments and descriptions of CDIAC`s information management systems, professional networking, and special bilateral agreements are also described.

  9. Carbon Dioxide Information Analysis Center: FY 1991 activities

    SciTech Connect

    Cushman, R.M.; Stoss, F.W.

    1992-06-01

    During the course of a fiscal year, Oak Ridge National Laboratory's Carbon Dioxide Information Analysis Center (CDIAC) distributes thousands of specially publications-numeric data packages (NDPs), computer model packages (CMPs), technical reports, public communication publications, newsletters, article reprints, and reference books-in response to requests for information related to global environmental issues, primarily those pertaining to climate change. CDIAC's staff also provides technical responses to specific inquiries related to carbon dioxide (CO{sub 2}), other trace gases, and climate. Hundreds of referrals to other researchers, policy analysts, information specialists, or organizations are also facilitated by CDIAC's staff. This report provides an account of the activities accomplished by CDIAC during the period October 1, 1990 to September 30, 1991. An organizational overview of CDIAC and its staff is supplemented by a detailed description of inquiries received and CDIAC's response to those inquiries. An analysis and description of the preparation and distribution of numeric data packages, computer model packages, technical reports, newsletters, factsheets, specially publications, and reprints is provided. Comments and descriptions of CDIAC's information management systems, professional networking, and special bilateral agreements are also described.

  10. Carbon Dioxide Information Analysis Center: FY 1992 activities

    SciTech Connect

    Cushman, R.M.; Stoss, F.W.

    1993-03-01

    During the course of a fiscal year, Oak Ridge National Laboratory`s Carbon Dioxide Information Analysis Center (CDIAC) distributes thousands of specialty publications-numeric data packages (NDPs), computer model packages (CMPs), technical reports, public communication publications, newsletters, article reprints, and reference books-in response to requests for information related to global environmental issues, primarily those pertaining to climate change. CDIACs staff also provides technical responses to specific inquiries related to carbon dioxide (CO{sub 2}), other trace gases, and climate. Hundreds of referrals to other researchers, policy analysts, information specialists, or organizations are also facilitated by CDIAC`s staff. This report provides an account of the activities accomplished by CDIAC during the period October 1, 1991 to September 30, 1992. An organizational overview of CDIAC and its staff is supplemented by a detailed description of inquiries received and CDIAC`s response to those inquiries. As analysis and description of the preparation and distribution of numeric data packages, computer model packages, technical reports, newsletters, fact sheets, specialty publications, and reprints is provided. Comments and descriptions of CDIAC`s information management systems, professional networking, and special bilateral agreements are also described.

  11. An investigation of evapotranspiration rates within mid-western agricultural systems in response to elevated carbon dioxide and ozone concentrations and climate change

    NASA Astrophysics Data System (ADS)

    Abdullah, W. F.; Lombardozzi, D.; Levis, S.; Bonan, G. B.

    2013-12-01

    Warith Featherstone Abdullah, Danica Lombardozzi, Samuel Levis and Gordon Bonan Jackson State University Dept. of Physics, Atmospheric Sciences & Geosciences National Center for Atmospheric Research Climate & Global Dynamics Because the human population is expected to surpass 8 billion by the year 2050, food security is a pressing issue. In the face of elevated temperatures associated with climate change (CC), elevated carbon dioxide (CO2) and elevated ozone (O3) concentrations, food productivity is uncertain. Plant stomata must be open to gain carbon which simultaneously causes water loss. Research suggests rising temperatures, elevated CO2 and elevated O3 in the future may impact plant stomata and change the rate plants lose water and take up carbon, affecting plant productivity and crop yields. Evapotranspiration (ET), latent heat fluxes, leaf carbon and net primary productivity (NPP) were analyzed in U.S Mid-west where crop density is greatest. Four simulations were run using the National Center for Atmospheric Research (NCAR) Community Land Model version 4 (CLM4) component of the Community Earth System Model (CESM) with an extended carbon-nitrogen model (CN). Analyses were based on June-July-August seasonal averages through 2080-2100 to compare the individual effects of CC, elevated CO2 and O3, and combined effects of all drivers. Results from model projections show increased ET with CC and all drivers combined, but only small changes from O3 or CO2 alone. Further results show that NPP was reduced with CC and O3 alone, but increased with CO2 alone and only slightly reduced with interacting components. The combined driver simulation, which most accurately represents future global change, suggests deteriorating water usage efficiency, thus potentially decreasing carbon uptake and crop production. However, further research is needed for verification. Midwest seasonal summation estimates for net primary productivity calculated by CLM4CN model. Climate change, CO2

  12. Carbon Dioxide Sequestration and ECBM in the Powder River Basin

    NASA Astrophysics Data System (ADS)

    Colmenares, L. B.; Zoback, M. D.

    2003-12-01

    Coal seams are both a source of coal bed methane (CBM) and a potential carbon dioxide sink. For sub-bituminous coals like those in the Powder River Basin (PRB), the CO2/CH4 adsorption ratio is approximately 10:1, which indicates the significant potential for sequestering carbon dioxide. In addition, injected carbon dioxide would also enhance the production of methane from the coal seam because of its higher adsorption capacity. This means that the injection of carbon dioxide in coal beds may have the dual benefit of sequestering carbon dioxide and enhancing CBM production. Moreover, if carbon dioxide injection efficiently displaces the adsorbed methane, it may reduce the amount of water produced from CBM wells as part of the depressurization process. Our work in the Powder River Basin indicates that drilling and completion operations result in hydraulic fracturing of the coal and possibly the adjacent strata. This would result in both excess CBM water production and inefficient depressurization of coals. We have been able to collect water-enhancement tests data in coals to obtain the magnitude of the least principal stress in the coal seam. The preliminary data we have analyzed indicates that the hydrofracs are horizontal in some areas because the least principal stress corresponds to the overburden. It is interesting to speculate that one could use horizontal hydrofracs near the bottom of the coal seam for carbon dioxide injection and a horizontal hydrofrac near the upper part of the coal seam for methane production.

  13. Forest management techniques for carbon dioxide storage

    SciTech Connect

    Fujimori, Takao

    1993-12-31

    In the global ecosystem concerning carbon dioxide content in the atmosphere, the forest ecosystem plays an important role. In effect, the ratio of forest biomass to total terrestrial biomass is about 90%, and the ratio of carbon stored in the forest biomass to that in the atmosphere is two thirds. When soils and detritus of forests are added, there is more C stored in forests than in the atmosphere, about 1.3 times or more. Thus, forests can be regarded as the great holder of C on earth. If the area of forest land on the earth is constantly maintained and forests are in the climax stage, the uptake of C and the release of C by and from the forests will balance. In this case, forests are neither sinks nor sources of CO{sub 2} although they store a large amount of C. However, when forests are deforested, they become a source of C; through human activities, forests have become a source of C. According to a report by the IPCC, 1.6{+-}1.2 PgC is annually added to the atmosphere by deforestation. According to the FAO (1992), the area of land deforested annually in the tropics from 1981 to 1990 was 16.9 x 10{sup 6} ha. This value is nearly half the area of Japanese land. The most important thing for the CO{sub 2} environment concerning forests is therefore how to reduce deforestation and to successfully implement a forestation or reforestation.

  14. Carbon dioxide warming of the early Earth.

    PubMed

    Arrhenius, G

    1997-02-01

    Svante Arrhenius' research in atmospheric physics extended beyond the recent past and the near future states of the Earth, which today are at the center of sociopolitical attention. His plan encompassed all of the physical phenomena known at the time to relate to the formation and evolution of stars and planets. His two-volume textbook on cosmic physics is a comprehensive synopsis of the field. The inquiry into the possible cause of the ice ages and the theory of selective wavelength filter control led Arrhenius to consider the surface states of the other terrestrial planets, and of the ancient Earth before it had been modified by the emergence of life. The rapid escape of hydrogen and the equilibration with igneous rocks required that carbon in the early atmosphere prevailed mainly in oxidized form as carbon dioxide, together with other photoactive gases exerting a greenhouse effect orders of magnitude larger than in our present atmosphere. This effect, together with the ensuing chemical processes, would have set the conditions for life to evolve on our planet, seeded from spores spreading through an infinite Universe, and propelled, as Arrhenius thought, by stellar radiation pressure.

  15. Carbon dioxide warming of the early Earth

    NASA Technical Reports Server (NTRS)

    Arrhenius, G.

    1997-01-01

    Svante Arrhenius' research in atmospheric physics extended beyond the recent past and the near future states of the Earth, which today are at the center of sociopolitical attention. His plan encompassed all of the physical phenomena known at the time to relate to the formation and evolution of stars and planets. His two-volume textbook on cosmic physics is a comprehensive synopsis of the field. The inquiry into the possible cause of the ice ages and the theory of selective wavelength filter control led Arrhenius to consider the surface states of the other terrestrial planets, and of the ancient Earth before it had been modified by the emergence of life. The rapid escape of hydrogen and the equilibration with igneous rocks required that carbon in the early atmosphere prevailed mainly in oxidized form as carbon dioxide, together with other photoactive gases exerting a greenhouse effect orders of magnitude larger than in our present atmosphere. This effect, together with the ensuing chemical processes, would have set the conditions for life to evolve on our planet, seeded from spores spreading through an infinite Universe, and propelled, as Arrhenius thought, by stellar radiation pressure.

  16. Carbon dioxide warming of the early Earth.

    PubMed

    Arrhenius, G

    1997-02-01

    Svante Arrhenius' research in atmospheric physics extended beyond the recent past and the near future states of the Earth, which today are at the center of sociopolitical attention. His plan encompassed all of the physical phenomena known at the time to relate to the formation and evolution of stars and planets. His two-volume textbook on cosmic physics is a comprehensive synopsis of the field. The inquiry into the possible cause of the ice ages and the theory of selective wavelength filter control led Arrhenius to consider the surface states of the other terrestrial planets, and of the ancient Earth before it had been modified by the emergence of life. The rapid escape of hydrogen and the equilibration with igneous rocks required that carbon in the early atmosphere prevailed mainly in oxidized form as carbon dioxide, together with other photoactive gases exerting a greenhouse effect orders of magnitude larger than in our present atmosphere. This effect, together with the ensuing chemical processes, would have set the conditions for life to evolve on our planet, seeded from spores spreading through an infinite Universe, and propelled, as Arrhenius thought, by stellar radiation pressure. PMID:11541253

  17. Interactions of future climate, carbon dioxide, and ozone change crop and forest productivity and water use

    NASA Astrophysics Data System (ADS)

    Lombardozzi, D.; Bonan, G. B.; Levis, S.

    2014-12-01

    The demand for agricultural and forest yield will continually increase as populations grow, though it is unclear how agricultural and forested ecosystem productivity and water use will respond to the interactions of changing climate, carbon dioxide and ozone. In ecosystems essential to resource production, it is critical to understand how productivity and water use will respond to these future changes. Previous research suggests that future climate and ozone can each decrease crop and timber yield and water use efficiency, while future carbon dioxide might increase yield and improve water use efficiency. However, the change in agricultural and forest water use and yield in response to the interactions among these variables has not yet been determined. We use the Community Land Model (CLM) to determine how changes in agricultural and timber water use and yield in response to the interactions of all three variables (climate, carbon dioxide, and ozone). Preliminary results suggest that future ozone and climate decrease forest and grain yield. However, carbon dioxide concentrations increase forest and grain yield, offsetting the decreases. Future climate increases evapotranspiration in all regions more than the decreases caused by carbon dioxide and ozone. The interactions of climate, carbon dioxide, and ozone decrease water use efficiency, with climate having the largest impact. These results demonstrate that, to maintain agricultural and forest productivity in the future, the demand for irrigation will increase.

  18. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    SciTech Connect

    David A. Green; Thomas Nelson; Brian S. Turk; Paul Box; Weijiong Li; Raghubir P. Gupta

    2005-07-01

    This report describes research conducted between April 1, 2005 and June 30, 2005 on the use of dry regenerable sorbents for removal of carbon dioxide from flue gas from coal combustion and synthesis gas from coal gasification. Supported sodium carbonate sorbents removed up to 76% of the carbon dioxide from simulated flue gas in a downflow cocurrent flow reactor system, with an approximate 15 second gas-solid contact time. This reaction proceeds at temperatures as low as 25 C. Lithium silicate sorbents remove carbon dioxide from high temperature simulated flue gas and simulated synthesis gas. Both sorbent types can be thermally regenerated and reused. The lithium silicate sorbent was tested in a thermogravimetric analyzer and in a 1-in quartz reactor at atmospheric pressure; tests were also conducted at elevated pressure in a 2-in diameter high temperature high pressure reactor system. The lithium sorbent reacts rapidly with carbon dioxide in flue gas at 350-500 C to absorb about 10% of the sorbent weight, then continues to react at a lower rate. The sorbent can be essentially completely regenerated at temperatures above 600 C and reused. In atmospheric pressure tests with synthesis gas of 10% initial carbon dioxide content, the sorbent removed over 90% of the carbon dioxide. An economic analysis of a downflow absorption process for removal of carbon dioxide from flue gas with a supported sodium carbonate sorbent suggests that a 90% efficient carbon dioxide capture system installed at a 500 MW{sub e} generating plant would have an incremental capital cost of $35 million ($91/kWe, assuming 20 percent for contingencies) and an operating cost of $0.0046/kWh. Assuming capital costs of $1,000/kW for a 500 MWe plant the capital cost of the down flow absorption process represents a less than 10% increase, thus meeting DOE goals as set forth in its Carbon Sequestration Technology Roadmap and Program Plan.

  19. Low Energy, Low Emissions: Sulfur Dioxide; Nitrogen Oxides, and Carbon Dioxide in Western Europe.

    ERIC Educational Resources Information Center

    Alcamo, Joseph; De Vries, Bert

    1992-01-01

    Links proposed low-energy scenarios for different Western European countries with the amount of pollutants that may result from these scenarios. Sulfur dioxide, nitrogen oxide, and carbon dioxide emissions are calculated for the 10 countries for which low-energy scenarios are available, resulting in reductions of 54%, 37%, and 40%, respectively.…

  20. Alkali metal carbon dioxide electrochemical system for energy storage and/or conversion of carbon dioxide to oxygen

    NASA Technical Reports Server (NTRS)

    Hagedorn, Norman H. (Inventor)

    1993-01-01

    An alkali metal, such as lithium, is the anodic reactant; carbon dioxide or a mixture of carbon dioxide and carbon monoxide is the cathodic reactant; and carbonate of the alkali metal is the electrolyte in an electrochemical cell for the storage and delivery of electrical energy. Additionally, alkali metal-carbon dioxide battery systems include a plurality of such electrochemical cells. Gold is a preferred catalyst for reducing the carbon dioxide at the cathode. The fuel cell of the invention produces electrochemical energy through the use of an anodic reactant which is extremely energetic and light, and a cathodic reactant which can be extracted from its environment and therefore exacts no transportation penalty. The invention is, therefore, especially useful in extraterrestrial environments.

  1. Alkali metal carbon dioxide electrochemical system for energy storage and/or conversion of carbon dioxide to oxygen

    NASA Astrophysics Data System (ADS)

    Hagedorn, Norman H.

    1993-05-01

    An alkali metal, such as lithium, is the anodic reactant; carbon dioxide or a mixture of carbon dioxide and carbon monoxide is the cathodic reactant; and carbonate of the alkali metal is the electrolyte in an electrochemical cell for the storage and delivery of electrical energy. Additionally, alkali metal-carbon dioxide battery systems include a plurality of such electrochemical cells. Gold is a preferred catalyst for reducing the carbon dioxide at the cathode. The fuel cell of the invention produces electrochemical energy through the use of an anodic reactant which is extremely energetic and light, and a cathodic reactant which can be extracted from its environment and therefore exacts no transportation penalty. The invention is, therefore, especially useful in extraterrestrial environments.

  2. Alkali metal carbon dioxide electrochemical system for energy storage and/or conversion of carbon dioxide to oxygen

    NASA Astrophysics Data System (ADS)

    Hagedorn, Norman H.

    1991-09-01

    An alkali metal, such as lithium, is the anodic reactant, carbon dioxide or a mixture of carbon dioxide and carbon monoxide is the cathodic reactant, and carbonate of the alkali metal is the electrolyte in an electrochemical cell for the storage and delivery of electrical energy. Additionally, alkali metal-carbon dioxide battery systems include a plurality of such electrochemical cells. Gold is a preferred catalyst for reducing the carbon dioxide at the cathode. The fuel cell of the invention produces electrochemical energy through the use of an anodic reactant which is extremely energetic and light, and a cathodic reactant which can be extracted from its environment and therefore exacts no transportation penalty. The invention is therefore especially useful in extraterrestrial environments.

  3. Dissolution of uranium dioxide in supercritical fluid carbon dioxide.

    PubMed

    Samsonov, M D; Wai, C M; Lee, S C; Kulyako, Y; Smart, N G

    2001-09-21

    Uranium dioxide can be dissolved in supercritical CO2 with a CO2-philic TBP-HNO3 complexant to form a highly soluble UO2(NO3)(2).2TBP complex; this new method of dissolving UO2 that requires no water or organic solvent may have important applications for reprocessing of spent nuclear fuels and for treatment of nuclear wastes.

  4. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    SciTech Connect

    David A. Green; Thomas Nelson; Brian S. Turk; Jeffrey W. Portzer; Raghubir P. Gupta

    2005-04-01

    This report describes research conducted between January 1, 2005 and March 31, 2005 on the use of dry regenerable sorbents for removal of carbon dioxide from flue gas. Engineered sorbents composed of sodium carbonate on a ceramic support were tested in a laboratory fluidized bed reactor system and found to be capable of essentially complete removal of carbon dioxide at 60 C in a short residence time. Upon breakthrough the sorbents can be thermally regenerated to recover essentially all of the absorbed carbon dioxide. An optimized supported sorbent tested in a pilot-scale entrained bed absorber retained its reactivity in multicycle tests and experienced no attrition. Removal of >90% of carbon dioxide in simulated flue gas was achieved in an entrained bed reactor.

  5. Fractional carbon dioxide laser in recalcitrant vulval lichen sclerosus.

    PubMed

    Lee, Andrew; Lim, Adrian; Fischer, Gayle

    2016-02-01

    Vulval lichen sclerosus is an uncommon skin condition that can usually be managed with topical corticosteroids to maintain remission. However, there is a subset of patients in whom it remains recalcitrant despite treatment with super-potent topical corticosteroids. We report a case series of four patients undergoing fractional carbon dioxide laser resurfacing and one with ablative carbon dioxide laser for severe, hyperkeratotic vulval lichen sclerosus not responding to super-potent topical corticosteroids. In these patients, carbon dioxide laser was successful in achieving remission. Their vulval lichen sclerosus was subsequently able to be maintained with topical corticosteroid treatment.

  6. A mathematical model of carbon dioxide flooding with hydrate formation

    NASA Astrophysics Data System (ADS)

    Tsypkin, G. G.

    2014-10-01

    The injection of carbon dioxide into a reservoir that contains methane and water in a free state is investigated. A mathematical model of this process is proposed that suggests the formation of the CO2 hydrate on the surface of the phase transition separating regions of methane and carbon dioxide. The conditions on the interface are derived, and an asymptotic solution of the problem is found. Critical diagrams are obtained that define parameter ranges in which there is full or partial transition of gaseous carbon dioxide to a hydrate state.

  7. Carbon Dioxide-Water Emulsions for Enhanced Oil Recovery and Permanent Sequestration of Carbon Dioxide

    SciTech Connect

    Ryan, David; Golomb, Dan; Shi, Guang; Shih, Cherry; Lewczuk, Rob; Miksch, Joshua; Manmode, Rahul; Mulagapati, Srihariraju; Malepati, Chetankurmar

    2011-09-30

    This project involves the use of an innovative new invention Particle Stabilized Emulsions (PSEs) of Carbon Dioxide-in-Water and Water-in-Carbon Dioxide for Enhanced Oil Recovery (EOR) and Permanent Sequestration of Carbon Dioxide. The EOR emulsion would be injected into a semi-depleted oil reservoir such as Dover 33 in Otsego County, Michigan. It is expected that the emulsion would dislocate the stranded heavy crude oil from the rock granule surfaces, reduce its viscosity, and increase its mobility. The advancing emulsion front should provide viscosity control which drives the reduced-viscosity oil toward the production wells. The make-up of the emulsion would be subsequently changed so it interacts with the surrounding rock minerals in order to enhance mineralization, thereby providing permanent sequestration of the injected CO{sub 2}. In Phase 1 of the project, the following tasks were accomplished: 1. Perform laboratory scale (mL/min) refinements on existing procedures for producing liquid carbon dioxide-in-water (C/W) and water-in-liquid carbon dioxide (W/C) emulsion stabilized by hydrophilic and hydrophobic fine particles, respectively, using a Kenics-type static mixer. 2. Design and cost evaluate scaled up (gal/min) C/W and W/C emulsification systems to be deployed in Phase 2 at the Otsego County semi-depleted oil field. 3. Design the modifications necessary to the present CO{sub 2} flooding system at Otsego County for emulsion injection. 4. Design monitoring and verification systems to be deployed in Phase 2 for measuring potential leakage of CO{sub 2} after emulsion injection. 5. Design production protocol to assess enhanced oil recovery with emulsion injection compared to present recovery with neat CO{sub 2} flooding. 6. Obtain Federal and State permits for emulsion injection. Initial research focused on creating particle stabilized emulsions with the smallest possible globule size so that the emulsion can penetrate even low-permeability crude

  8. Experimental carbon dioxide laser brain lesions and intracranial dynamics. Part 2. Effect on brain water content and its response to acute therapy

    SciTech Connect

    Tiznado, E.G.; James, H.E.; Moore, S.

    1985-04-01

    Experimental brain lesions were created over the left parietooccipital cortex of the albino rabbit through the intact dura mater with high radiating carbon dioxide laser energy. The brain water content was studied 2, 6, and 24 hours after the insult. Another two groups of animals received acute therapy with either dexamethasone (1 mg/kg) or furosemide (1 mg/kg). In all groups, Evans blue extravasation uniformly extended from the impact crater into the surrounding white matter. The brain water content in the gray matter was elevated from the control value by 2 hours after impact and remained elevated at 6 and 24 hours. The white matter brain water content did not increase until 6 hours after impact and remained elevated in the 24-hour group. After dexamethasone treatment, there was a significant decrease of water in the gray matter, but not in the white matter. With furosemide therapy, there was no reduction of gray or white matter brain water.

  9. Membranes for separation of carbon dioxide

    DOEpatents

    Ku, Anthony Yu-Chung; Ruud, James Anthony; Ramaswamy, Vidya; Willson, Patrick Daniel; Gao, Yan

    2011-03-01

    Methods for separating carbon dioxide from a fluid stream at a temperature higher than about 200.degree. C. with selectivity higher than Knudsen diffusion selectivity include contacting a porous membrane with the fluid stream to preferentially transport carbon dioxide. The porous membrane includes a porous support and a continuous porous separation layer disposed on a surface of the porous support and extending between the fluid stream and the porous support layer. The porous support comprises alumina, silica, zirconia, stabilized zirconia, stainless steel, titanium, nickel-based alloys, aluminum-based alloys, zirconium-based alloys or a combination thereof. Median pore size of the porous separation layer is less than about 10 nm, and the porous separation layer comprises titania, MgO, CaO, SrO, BaO, La.sub.2O.sub.3, CeO.sub.2, HfO.sub.2, Y.sub.2O.sub.3, VO.sub.z, NbO.sub.z, TaO.sub.z, ATiO.sub.3, AZrO.sub.3, AAl.sub.2O.sub.4, A.sup.1FeO.sub.3, A.sup.1MnO.sub.3, A.sup.1CoO.sub.3, A.sup.1NiO.sub.3, A.sup.2HfO.sub.3, A.sup.3 CeO.sub.3, Li.sub.2ZrO.sub.3, Li.sub.2SiO.sub.3, Li.sub.2TiO.sub.3, Li.sub.2HfO.sub.3, A.sup.4N.sup.1.sub.yO.sub.z, Y.sub.xN.sup.1.sub.yO.sub.z, La.sub.xN.sup.1.sub.yO.sub.z, HfN.sup.2.sub.yO.sub.z, or a combination thereof; wherein A is La, Mg, Ca, Sr or Ba; A.sup.1 is La, Ca, Sr or Ba; A.sup.2 is Ca, Sr or Ba; A.sup.3 is Sr or Ba; A.sup.4 is Mg, Ca, Sr, Ba, Ti or Zr; N.sup.1 is V, Nb, Ta, Cr, Mo, W, Mn, Si or Ge; N.sup.2 is V, Mo, W or Si; x is 1 or 2; y ranges from 1 to 3; and z ranges from 2 to 7.

  10. Atmospheric carbon dioxide: its role in maintaining phytoplankton standing crops.

    PubMed

    Schindler, D W; Brunskill, G J; Emerson, S; Broecker, W S; Peng, T H

    1972-09-29

    The rate of invasion of carbon dioxide into an artificially eutrophic Canadian Shield lake with insufficient internal sources of carbon was determined by two methods: measuring the carbon : nitrogen : phosphorus ratios of seston after weekly additions of nitrogen and phosphorus, and measuring the loss of radon-222 tracer from the epilimnion. Both methods gave an invasion rate of about 0.2 gram of carbon per square meter per day. The results demonstrate that invasion of atmospheric carbon dioxide may be sufficient to permit eutrophication of any body of water receiving an adequate supply of phosphorus and nitrogen. PMID:5057624

  11. Multiphase flow of carbon dioxide and brine in dual porosity carbonates

    NASA Astrophysics Data System (ADS)

    Pentland, Christopher; Oedai, Sjaam; Ott, Holger

    2014-05-01

    The storage of carbon dioxide in subsurface formations presents a challenge in terms of multiphase flow characterisation. Project planning requires an understanding of multiphase flow characteristics such as the relationship between relative permeability and saturation. At present there are only a limited number of relative permeability relations for carbon dioxide-brine fluid systems, most of which are measured on sandstone rocks. In this study coreflood experiments are performed to investigate the relative permeability of carbon dioxide and brine in two dual porosity carbonate systems. Carbon dioxide is injected into the brine saturated rocks in a primary drainage process. The rock fluid system is pre-equilibrated to avoid chemical reactions and physical mass transfer between phases. The pressure drop across the samples, the amount of brine displaced and the saturation distribution within the rocks are measured. The experiments are repeated on the same rocks for the decane-brine fluid system. The experimental data is interpreted by simulating the experiments with a continuum scale Darcy solver. Selected functional representations of relative permeability are investigated, the parameters of which are chosen such that a least squares objective function is minimised (i.e. the difference between experimental observations and simulated response). The match between simulation and measurement is dependent upon the form of the functional representations. The best agreement is achieved with the Corey [Brooks and Corey, 1964] or modified Corey [Masalmeh et al., 2007] functions which best represent the relative permeability of brine at low brine saturations. The relative permeability of carbon dioxide is shown to be lower than the relative permeability of decane over the saturation ranges investigated. The relative permeability of the brine phase is comparable for the two fluid systems. These observations are consistent with the rocks being water-wet. During the experiment

  12. Progress in Measurement of Carbon Dioxide Using a Broadband Lidar

    NASA Technical Reports Server (NTRS)

    Heaps, William S.

    2010-01-01

    In order to better understand the budget of carbon dioxide in the Earth's atmosphere it is necessary to develop a global high precision understanding of the carbon dioxide column. In order to uncover the 'missing sink" that is responsible for the large discrepancies in the budget as we presently understand it calculation has indicated that measurement accuracy on the order of 1 ppm is necessary. Because typical column average CO2 has now reached 380 ppm this represents a precision on the order of .25% for these column measurements. No species has ever been measured from space at such a precision. In recognition of the importance of understanding the CO2 budget in order to evaluate its impact on global warming the National Research Council in its decadal survey report to NASA recommended planning for a laser based total CO2 mapping mission in the near future. The extreme measurement accuracy requirements on this mission places very strong requirements on the laser system used for the measurement. This work presents an overview of the characteristics necessary in a laser system used to make this measurement. Consideration is given to the temperature dependence, pressure broadening, and pressure shift of the CO2 lines themselves and how these impact the laser system characteristics We have been examining the possibility of making precise measurements of atmospheric carbon dioxide using broad band source of radiation. This means that many of the difficulties in wavelength control can be treated in the detector portion of the system rather than the laser source. It also greatly reduces the number of individual lasers required to make a measurement. Simplifications such as these are extremely desirable for systems designed to operate from space.

  13. Young organic matter as a source of carbon dioxide outgassing from Amazonian rivers

    SciTech Connect

    Mayorga, E; Aufdenkampe, A K; Masiello, C A; Krusche, A V; Hedges, J I; Quay, P D; Richey, J E; Brown, T A

    2005-06-23

    Rivers are generally supersaturated with respect to carbon dioxide, resulting in large gas evasion fluxes that can be a significant component of regional net carbon budgets. Amazonian rivers were recently shown to outgas more than ten times the amount of carbon exported to the ocean in the form of total organic carbon or dissolved inorganic carbon. High carbon dioxide concentrations in rivers originate largely from in situ respiration of organic carbon, but little agreement exists about the sources or turnover times of this carbon. Here we present results of an extensive survey of the carbon isotope composition ({sup 13}C and {sup 14}C) of dissolved inorganic carbon and three size-fractions of organic carbon across the Amazonian river system. We find that respiration of contemporary organic matter (less than 5 years old) originating on land and near rivers is the dominant source of excess carbon dioxide that drives outgassing in mid-size to large rivers, although we find that bulk organic carbon fractions transported by these rivers range from tens to thousands of years in age. We therefore suggest that a small, rapidly cycling pool of organic carbon is responsible for the large carbon fluxes from land to water to atmosphere in the humid tropics.

  14. Young organic matter as a source of carbon dioxide outgassing from Amazonian rivers.

    PubMed

    Mayorga, Emilio; Aufdenkampe, Anthony K; Masiello, Caroline A; Krusche, Alex V; Hedges, John I; Quay, Paul D; Richey, Jeffrey E; Brown, Thomas A

    2005-07-28

    Rivers are generally supersaturated with respect to carbon dioxide, resulting in large gas evasion fluxes that can be a significant component of regional net carbon budgets. Amazonian rivers were recently shown to outgas more than ten times the amount of carbon exported to the ocean in the form of total organic carbon or dissolved inorganic carbon. High carbon dioxide concentrations in rivers originate largely from in situ respiration of organic carbon, but little agreement exists about the sources or turnover times of this carbon. Here we present results of an extensive survey of the carbon isotope composition (13C and 14C) of dissolved inorganic carbon and three size-fractions of organic carbon across the Amazonian river system. We find that respiration of contemporary organic matter (less than five years old) originating on land and near rivers is the dominant source of excess carbon dioxide that drives outgassing in medium to large rivers, although we find that bulk organic carbon fractions transported by these rivers range from tens to thousands of years in age. We therefore suggest that a small, rapidly cycling pool of organic carbon is responsible for the large carbon fluxes from land to water to atmosphere in the humid tropics.

  15. Carbon ion pump for removal of carbon dioxide from combustion gas and other gas mixtures

    DOEpatents

    Aines, Roger D.; Bourcier, William L.

    2010-11-09

    A novel method and system of separating carbon dioxide from flue gas is introduced. Instead of relying on large temperature or pressure changes to remove carbon dioxide from a solvent used to absorb it from flue gas, the ion pump method, as disclosed herein, dramatically increases the concentration of dissolved carbonate ion in solution. This increases the overlying vapor pressure of carbon dioxide gas, permitting carbon dioxide to be removed from the downstream side of the ion pump as a pure gas. The ion pumping may be obtained from reverse osmosis, electrodialysis, thermal desalination methods, or an ion pump system having an oscillating flow in synchronization with an induced electric field.

  16. Carbon ion pump for removal of carbon dioxide from combustion gas and other gas mixtures

    DOEpatents

    Aines, Roger D.; Bourcier, William L.

    2014-08-19

    A novel method and system of separating carbon dioxide from flue gas is introduced. Instead of relying on large temperature or pressure changes to remove carbon dioxide from a solvent used to absorb it from flue gas, the ion pump method, as disclosed herein, dramatically increases the concentration of dissolved carbonate ion in solution. This increases the overlying vapor pressure of carbon dioxide gas, permitting carbon dioxide to be removed from the downstream side of the ion pump as a pure gas. The ion pumping may be obtained from reverse osmosis, electrodialysis, thermal desalination methods, or an ion pump system having an oscillating flow in synchronization with an induced electric field.

  17. The source of carbon dioxide for gastric acid production.

    PubMed

    Steer, Howard

    2009-01-01

    The source of carbon dioxide for the chemical reaction leading to the production of gastric acid is unknown. The decarboxylation of an amino acid releases carbon dioxide. Pepsinogens provide a rich source of the amino acid arginine. Both the source of carbon dioxide, arginine, and the consequence of arginine decarboxylation, agmatine, have been studied. The site of carbon dioxide production has been related to the survival of the parietal cell. An immunohistochemical study has been carried out on glycol methacrylate embedded gastric biopsies from the normal stomach of 38 adult patients. The sections have been stained using polyclonal antibody to pepsinogen II, polyclonal antibody to agmatine, and polyclonal antibody to Helicobacter pylori. Pepsinogen II and agmatine are found in the parietal cell canaliculi. This is consistent with the production of carbon dioxide from arginine in the parietal cell canaliculi. Evidence is presented for the decarboxylation of arginine derived from the activation segment of pepsinogen as the source of carbon dioxide for the production of gastric acid. The production of carbon dioxide by the decarboxylation of arginine in the parietal cell canaliculus enables the extracellular hydration of carbon dioxide at the known site of carbonic anhydrase activity. The extracellular production of acid in the canaliculus together with the presence of agmatine helps to explain why the parietal cells are not destroyed during the formation of gastric acid. Agmatine is found in the mucus secreting cells of the stomach and its role in acid protection of the stomach is discussed. Anat Rec, 2009. (c) 2008 Wiley-Liss, Inc. PMID:18951509

  18. Pretreatment for cellulose hydrolysis by carbon dioxide explosion

    SciTech Connect

    Zheng, Y.; Lin, H.M.; Tsao, G.T.

    1998-11-01

    Cellulosic materials were treated with supercritical carbon dioxide to increase the reactivity of cellulose, thereby to enhance the rate and the extent of cellulose hydrolysis. In this pretreatment process, the cellulosic materials such as Avicel, recycled paper mix, sugarcane bagasse and the repulping waste of recycled paper are placed in a reactor under pressurized carbon dioxide at 35 C for a controlled time period. Upon an explosive release of the carbon dioxide pressure, the disruption of the cellulosic structure increases the accessible surface area of the cellulosic substrate to enzymatic hydrolysis. Results indicate that supercritical carbon dioxide is effective for pretreatment of cellulose. An increase in pressure facilitates the faster penetration of carbon dioxide molecules into the crystalline structures, thus more glucose is produced from cellulosic materials after the explosion as compared to those without the pretreatment. This explosion pretreatment enhances the rate of cellulosic material hydrolysis as well as increases glucose yield by as much as 50%. Results from the simultaneous saccharification and fermentation tests also show the increase in the available carbon source from the cellulosic materials for fermentation to produce ethanol. As an alternative method, this supercritical carbon dioxide explosion has a possibility to reduce expense compared with ammonia explosion, and since it is operated at the low temperature, it will not cause degradation of sugars such as those treated with steam explosion due to the high-temperature involved.

  19. 46 CFR 167.45-45 - Carbon dioxide fire-extinguishing system requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Carbon dioxide fire-extinguishing system requirements... Carbon dioxide fire-extinguishing system requirements. (a) When a carbon dioxide (CO2) smothering system is fitted in the boiler room, the quantity of carbon dioxide carried shall be sufficient to give...

  20. 27 CFR 24.245 - Use of carbon dioxide in still wine.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Use of carbon dioxide in... Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still wine... than 0.392 grams of carbon dioxide per 100 milliliters of wine. However, a tolerance of not more than...

  1. 46 CFR 35.40-7 - Carbon dioxide alarm-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Carbon dioxide alarm-T/ALL. 35.40-7 Section 35.40-7... Requirements-TB/ALL. § 35.40-7 Carbon dioxide alarm—T/ALL. Adjacent to all carbon dioxide fire extinguishing... AT ONCE. CARBON DIOXIDE BEING RELEASED.”...

  2. 46 CFR 167.45-45 - Carbon dioxide fire-extinguishing system requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide fire-extinguishing system requirements... Carbon dioxide fire-extinguishing system requirements. (a) When a carbon dioxide (CO2) smothering system is fitted in the boiler room, the quantity of carbon dioxide carried shall be sufficient to give...

  3. 46 CFR 35.40-8 - Carbon dioxide warning signs-T/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Carbon dioxide warning signs-T/ALL. 35.40-8 Section 35... Marking Requirements-TB/ALL § 35.40-8 Carbon dioxide warning signs—T/ALL. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space into which...

  4. 27 CFR 24.245 - Use of carbon dioxide in still wine.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Use of carbon dioxide in... Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still wine... than 0.392 grams of carbon dioxide per 100 milliliters of wine. However, a tolerance of not more than...

  5. 27 CFR 24.245 - Use of carbon dioxide in still wine.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Use of carbon dioxide in... Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still wine... than 0.392 grams of carbon dioxide per 100 milliliters of wine. However, a tolerance of not more than...

  6. 49 CFR 195.4 - Compatibility necessary for transportation of hazardous liquids or carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... hazardous liquids or carbon dioxide. 195.4 Section 195.4 Transportation Other Regulations Relating to... necessary for transportation of hazardous liquids or carbon dioxide. No person may transport any hazardous liquid or carbon dioxide unless the hazardous liquid or carbon dioxide is chemically compatible with...

  7. 21 CFR 179.43 - Carbon dioxide laser for etching food.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Carbon dioxide laser for etching food. 179.43... FOOD Radiation and Radiation Sources § 179.43 Carbon dioxide laser for etching food. Carbon dioxide... conditions: (a) The radiation source consists of a carbon dioxide laser designed to emit pulsed...

  8. 46 CFR 35.40-7 - Carbon dioxide alarm-T/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Carbon dioxide alarm-T/ALL. 35.40-7 Section 35.40-7... Requirements-TB/ALL. § 35.40-7 Carbon dioxide alarm—T/ALL. Adjacent to all carbon dioxide fire extinguishing... AT ONCE. CARBON DIOXIDE BEING RELEASED.”...

  9. 49 CFR 195.4 - Compatibility necessary for transportation of hazardous liquids or carbon dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... hazardous liquids or carbon dioxide. 195.4 Section 195.4 Transportation Other Regulations Relating to... necessary for transportation of hazardous liquids or carbon dioxide. No person may transport any hazardous liquid or carbon dioxide unless the hazardous liquid or carbon dioxide is chemically compatible with...

  10. 49 CFR 195.4 - Compatibility necessary for transportation of hazardous liquids or carbon dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... hazardous liquids or carbon dioxide. 195.4 Section 195.4 Transportation Other Regulations Relating to... necessary for transportation of hazardous liquids or carbon dioxide. No person may transport any hazardous liquid or carbon dioxide unless the hazardous liquid or carbon dioxide is chemically compatible with...

  11. 21 CFR 179.43 - Carbon dioxide laser for etching food.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Carbon dioxide laser for etching food. 179.43... § 179.43 Carbon dioxide laser for etching food. Carbon dioxide laser light may be safely used for... consists of a carbon dioxide laser designed to emit pulsed infrared radiation with a wavelength of...

  12. 49 CFR 195.4 - Compatibility necessary for transportation of hazardous liquids or carbon dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... hazardous liquids or carbon dioxide. 195.4 Section 195.4 Transportation Other Regulations Relating to... necessary for transportation of hazardous liquids or carbon dioxide. No person may transport any hazardous liquid or carbon dioxide unless the hazardous liquid or carbon dioxide is chemically compatible with...

  13. 46 CFR 167.45-45 - Carbon dioxide fire extinguishing system requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Carbon dioxide fire extinguishing system requirements... Carbon dioxide fire extinguishing system requirements. (a) When a carbon dioxide (CO2) smothering system is fitted in the boiler room, the quantity of carbon dioxide carried shall be sufficient to give...

  14. 27 CFR 24.245 - Use of carbon dioxide in still wine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Use of carbon dioxide in... Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still wine... than 0.392 grams of carbon dioxide per 100 milliliters of wine. However, a tolerance of not more than...

  15. 49 CFR 195.4 - Compatibility necessary for transportation of hazardous liquids or carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... hazardous liquids or carbon dioxide. 195.4 Section 195.4 Transportation Other Regulations Relating to... necessary for transportation of hazardous liquids or carbon dioxide. No person may transport any hazardous liquid or carbon dioxide unless the hazardous liquid or carbon dioxide is chemically compatible with...

  16. 27 CFR 24.245 - Use of carbon dioxide in still wine.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Use of carbon dioxide in... Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still wine... than 0.392 grams of carbon dioxide per 100 milliliters of wine. However, a tolerance of not more than...

  17. 46 CFR 35.40-8 - Carbon dioxide warning signs-T/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Carbon dioxide warning signs-T/ALL. 35.40-8 Section 35... Marking Requirements-TB/ALL § 35.40-8 Carbon dioxide warning signs—T/ALL. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space into which...

  18. 46 CFR 167.45-45 - Carbon dioxide fire extinguishing system requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Carbon dioxide fire extinguishing system requirements... Carbon dioxide fire extinguishing system requirements. (a) When a carbon dioxide (CO2) smothering system is fitted in the boiler room, the quantity of carbon dioxide carried shall be sufficient to give...

  19. 46 CFR 35.40-8 - Carbon dioxide warning signs-T/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Carbon dioxide warning signs-T/ALL. 35.40-8 Section 35... Marking Requirements-TB/ALL § 35.40-8 Carbon dioxide warning signs—T/ALL. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space into which...

  20. 21 CFR 862.1160 - Bicarbonate/carbon dioxide test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Bicarbonate/carbon dioxide test system. 862.1160... Systems § 862.1160 Bicarbonate/carbon dioxide test system. (a) Identification. A bicarbonate/carbon dioxide test system is a device intended to measure bicarbonate/carbon dioxide in plasma, serum, and...